This is python.info, produced by makeinfo version 7.1 from python.texi.

     Python 3.14.2, febbraio 01, 2026

     Author name not set

     Copyright © 2001 Python Software Foundation

INFO-DIR-SECTION Miscellaneous
START-INFO-DIR-ENTRY
* python: (python.info). One line description of project
END-INFO-DIR-ENTRY


   Generated by Sphinx 8.2.3.


File: python.info,  Node: Top,  Next: Novità in Python,  Up: (dir)

Python
******

     Python 3.14.2, febbraio 01, 2026

     Author name not set

     Copyright © 2001 Python Software Foundation

* Menu:

* Novità in Python::
* Tutorial su Python::
* Python Setup and Usage::
* The Python Language Reference::
* The Python Standard Library::
* Extending and Embedding the Python Interpreter::
* Python/C API Reference Manual::
* Installing Python Modules::
* Python HOWTOs::
* Python Frequently Asked Questions::
* Deprecations::
* Glossary::
* About this documentation::
* Come comportarsi con i bug::
* Copyright::
* Storia e licenza::
* Indice del modulo Python::
* Indice::

 -- The Detailed Node Listing --

Novità in Python

* What’s new in Python 3.14: What’s new in Python 3 14.
* What’s New In Python 3.13: What’s New In Python 3 13.
* Novità in Python 3.12: Novità in Python 3 12.
* What’s New In Python 3.11: What’s New In Python 3 11.
* What’s New In Python 3.10: What’s New In Python 3 10.
* What’s New In Python 3.9: What’s New In Python 3 9.
* What’s New In Python 3.8: What’s New In Python 3 8.
* What’s New In Python 3.7: What’s New In Python 3 7.
* What’s New In Python 3.6: What’s New In Python 3 6.
* What’s New In Python 3.5: What’s New In Python 3 5.
* What’s New In Python 3.4: What’s New In Python 3 4.
* What’s New In Python 3.3: What’s New In Python 3 3.
* What’s New In Python 3.2: What’s New In Python 3 2.
* What’s New In Python 3.1: What’s New In Python 3 1.
* What’s New In Python 3.0: What’s New In Python 3 0.
* What’s New in Python 2.7: What’s New in Python 2 7.
* What’s New in Python 2.6: What’s New in Python 2 6.
* What’s New in Python 2.5: What’s New in Python 2 5.
* What’s New in Python 2.4: What’s New in Python 2 4.
* What’s New in Python 2.3: What’s New in Python 2 3.
* What’s New in Python 2.2: What’s New in Python 2 2.
* What’s New in Python 2.1: What’s New in Python 2 1.
* What’s New in Python 2.0: What’s New in Python 2 0.
* Changelog::

What’s new in Python 3.14

* Summary – Release highlights::
* New features::
* Other language changes::
* New modules::
* Improved modules::
* Optimizations::
* Removed::
* Deprecated::
* CPython bytecode changes::
* C API changes::
* Build changes::
* Porting to Python 3.14: Porting to Python 3 14.
* Notable changes in 3.14.1: Notable changes in 3 14 1.

New features

* PEP 649 & PEP 749; Deferred evaluation of annotations: PEP 649 & PEP 749 Deferred evaluation of annotations.
* PEP 734; Multiple interpreters in the standard library: PEP 734 Multiple interpreters in the standard library.
* PEP 750; Template string literals: PEP 750 Template string literals.
* PEP 768; Safe external debugger interface: PEP 768 Safe external debugger interface.
* A new type of interpreter::
* Free-threaded mode improvements::
* Improved error messages::
* PEP 784; Zstandard support in the standard library: PEP 784 Zstandard support in the standard library.
* Asyncio introspection capabilities::
* Concurrent safe warnings control::

Other language changes

* Built-ins::
* Command line and environment::
* PEP 758; Allow except and except* expressions without brackets: PEP 758 Allow except and except* expressions without brackets.
* PEP 765; Control flow in finally blocks: PEP 765 Control flow in finally blocks.
* Incremental garbage collection::
* Default interactive shell::

Improved modules

* argparse::
* ast::
* asyncio::
* calendar::
* concurrent.futures: concurrent futures.
* configparser::
* contextvars::
* ctypes::
* curses::
* datetime::
* decimal::
* difflib::
* dis::
* errno::
* faulthandler::
* fnmatch::
* fractions::
* functools::
* getopt::
* getpass::
* graphlib::
* heapq::
* hmac::
* http::
* imaplib::
* inspect::
* io::
* json::
* linecache::
* logging.handlers: logging handlers.
* math::
* mimetypes::
* multiprocessing::
* operator::
* os::
* os.path: os path.
* pathlib::
* pdb::
* pickle::
* platform::
* pydoc::
* re::
* socket::
* ssl::
* struct::
* symtable::
* sys::
* sys.monitoring: sys monitoring.
* sysconfig::
* tarfile::
* threading::
* tkinter::
* turtle::
* types::
* typing::
* unicodedata::
* unittest::
* urllib::
* uuid::
* webbrowser::
* zipfile::

Optimizations

* asyncio: asyncio<2>.
* base64::
* bdb::
* difflib: difflib<2>.
* gc::
* io: io<2>.
* pathlib: pathlib<2>.
* pdb: pdb<2>.
* textwrap::
* uuid: uuid<2>.
* zlib::

Removed

* argparse: argparse<2>.
* ast: ast<2>.
* asyncio: asyncio<3>.
* email::
* importlib.abc: importlib abc.
* itertools::
* pathlib: pathlib<3>.
* pkgutil::
* pty::
* sqlite3::
* urllib: urllib<2>.

Deprecated

* New deprecations::
* Pending removal in Python 3.15: Pending removal in Python 3 15.
* Pending removal in Python 3.16: Pending removal in Python 3 16.
* Pending removal in Python 3.17: Pending removal in Python 3 17.
* Pending removal in Python 3.18: Pending removal in Python 3 18.
* Pending removal in Python 3.19: Pending removal in Python 3 19.
* Pending removal in future versions::

CPython bytecode changes

* Pseudo-instructions::

C API changes

* Python configuration C API::
* New features in the C API::
* Limited C API changes::
* Removed C APIs::
* Deprecated C APIs::

Deprecated C APIs

* Pending removal in Python 3.15: Pending removal in Python 3 15<2>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<2>.
* Pending removal in Python 3.18: Pending removal in Python 3 18<2>.
* Pending removal in future versions: Pending removal in future versions<2>.

Build changes

* build-details.json: build-details json.
* Discontinuation of PGP signatures::
* Free-threaded Python is officially supported::
* Binary releases for the experimental just-in-time compiler::

Porting to Python 3.14

* Changes in the Python API::
* Changes in annotations (PEP 649 and PEP 749): Changes in annotations PEP 649 and PEP 749.
* Changes in the C API::

Changes in annotations (PEP 649 and PEP 749)

* Implications for annotated code::
* Implications for readers of __annotations__::
* Related changes::
* from __future__ import annotations::

What’s New In Python 3.13

* Summary – Release Highlights::
* New Features::
* Other Language Changes::
* New Modules::
* Improved Modules::
* Optimizations: Optimizations<2>.
* Removed Modules And APIs::
* New Deprecations::
* CPython Bytecode Changes::
* C API Changes::
* Build Changes::
* Porting to Python 3.13: Porting to Python 3 13.
* Regression Test Changes::

New Features

* A better interactive interpreter::
* Improved error messages: Improved error messages<2>.
* Free-threaded CPython::
* An experimental just-in-time (JIT) compiler: An experimental just-in-time JIT compiler.
* Defined mutation semantics for locals(): Defined mutation semantics for locals.
* Support for mobile platforms::

Improved Modules

* argparse: argparse<3>.
* array::
* ast: ast<3>.
* asyncio: asyncio<4>.
* base64: base64<2>.
* compileall::
* concurrent.futures: concurrent futures<2>.
* configparser: configparser<2>.
* copy::
* ctypes: ctypes<2>.
* dbm::
* dis: dis<2>.
* doctest::
* email: email<2>.
* enum::
* fractions: fractions<2>.
* glob::
* importlib::
* io: io<3>.
* ipaddress::
* itertools: itertools<2>.
* marshal::
* math: math<2>.
* mimetypes: mimetypes<2>.
* mmap::
* multiprocessing: multiprocessing<2>.
* os: os<2>.
* os.path: os path<2>.
* pathlib: pathlib<4>.
* pdb: pdb<3>.
* queue::
* random::
* re: re<2>.
* shutil::
* site::
* sqlite3: sqlite3<2>.
* ssl: ssl<2>.
* statistics::
* subprocess::
* sys: sys<2>.
* tempfile::
* time::
* tkinter: tkinter<2>.
* traceback::
* types: types<2>.
* typing: typing<2>.
* unicodedata: unicodedata<2>.
* venv::
* warnings::
* xml::
* zipimport::

Removed Modules And APIs

* PEP 594; Remove «dead batteries» from the standard library: PEP 594 Remove «dead batteries» from the standard library.
* 2to3::
* builtins::
* configparser: configparser<3>.
* importlib.metadata: importlib metadata.
* locale::
* opcode::
* optparse::
* pathlib: pathlib<5>.
* re: re<3>.
* tkinter.tix: tkinter tix.
* turtle: turtle<2>.
* typing: typing<3>.
* unittest: unittest<2>.
* urllib: urllib<3>.
* webbrowser: webbrowser<2>.

New Deprecations

* Pending removal in Python 3.14: Pending removal in Python 3 14.
* Pending removal in Python 3.15: Pending removal in Python 3 15<3>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<3>.
* Pending removal in Python 3.17: Pending removal in Python 3 17<2>.
* Pending removal in Python 3.18: Pending removal in Python 3 18<3>.
* Pending removal in Python 3.19: Pending removal in Python 3 19<2>.
* Pending removal in future versions: Pending removal in future versions<3>.

C API Changes

* New Features: New Features<2>.
* Changed C APIs::
* Limited C API Changes::
* Removed C APIs: Removed C APIs<2>.
* Deprecated C APIs: Deprecated C APIs<2>.

Deprecated C APIs

* Pending removal in Python 3.14: Pending removal in Python 3 14<2>.
* Pending removal in Python 3.15: Pending removal in Python 3 15<4>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<4>.
* Pending removal in Python 3.18: Pending removal in Python 3 18<4>.
* Pending removal in future versions: Pending removal in future versions<4>.

Porting to Python 3.13

* Changes in the Python API: Changes in the Python API<2>.
* Changes in the C API: Changes in the C API<2>.

Novità in Python 3.12

* Sommario – Punti salienti del rilascio::
* Nuove Funzionalità::
* Nuove funzionalità relative agli hint di tipo::
* Altre modifiche al Linguaggio::
* Nuovi Moduli::
* Moduli Migliorati::
* Ottimizzazioni::
* Modifiche al bytecode di CPython::
* Demos e Tools::
* Deprecato::
* Rimosso::
* Porting a Python 3.12: Porting a Python 3 12.
* Modifiche alla Build::
* Modifiche all’API C::

Nuove Funzionalità

* PEP 695; Sintassi dei Parametri di Tipo: PEP 695 Sintassi dei Parametri di Tipo.
* PEP 701; Formalizzazione sintattica delle f-string: PEP 701 Formalizzazione sintattica delle f-string.
* PEP 684; Un GIL per interprete: PEP 684 Un GIL per interprete.
* PEP 669; Monitoraggio a basso impatto per CPython: PEP 669 Monitoraggio a basso impatto per CPython.
* PEP 688; Rendere accessibile il protocollo buffer in Python: PEP 688 Rendere accessibile il protocollo buffer in Python.
* PEP 709; Inlining delle comprehension: PEP 709 Inlining delle comprehension.
* Messaggi di errore migliorati::

Nuove funzionalità relative agli hint di tipo

* PEP 692; Utilizzo di TypedDict per una digitazione **kwargs più precisa: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa.
* PEP 698; Decoratore Override per tipizzazione statica: PEP 698 Decoratore Override per tipizzazione statica.

Moduli Migliorati

* array: array<2>.
* asyncio: asyncio<5>.
* calendar: calendar<2>.
* csv::
* dis: dis<3>.
* fractions: fractions<3>.
* importlib.resources: importlib resources.
* inspect: inspect<2>.
* itertools: itertools<3>.
* matematica::
* os: os<3>.
* os.path: os path<3>.
* pathlib: pathlib<6>.
* platform: platform<2>.
* pdb: pdb<4>.
* random: random<2>.
* shutil: shutil<2>.
* sqlite3: sqlite3<3>.
* statistica::
* sys: sys<3>.
* tempfile: tempfile<2>.
* threading: threading<2>.
* tkinter: tkinter<3>.
* tokenize::
* types: types<3>.
* typing: typing<4>.
* unicodedata: unicodedata<3>.
* unittest: unittest<3>.
* uuid: uuid<3>.

Deprecato

* Pending removal in Python 3.13: Pending removal in Python 3 13.
* Pending removal in Python 3.14: Pending removal in Python 3 14<3>.
* Pending removal in Python 3.15: Pending removal in Python 3 15<5>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<5>.
* Pending removal in Python 3.17: Pending removal in Python 3 17<3>.
* Pending removal in future versions: Pending removal in future versions<5>.

Rimosso

* asynchat e asyncore::
* configparser: configparser<4>.
* distutils::
* ensurepip::
* enum: enum<2>.
* ftplib::
* gzip::
* hashlib::
* importlib: importlib<2>.
* imp::
* io: io<4>.
* locale: locale<2>.
* smtpd::
* sqlite3: sqlite3<4>.
* ssl: ssl<3>.
* unittest: unittest<4>.
* webbrowser: webbrowser<3>.
* xml.etree.ElementTree: xml etree ElementTree.
* zipimport: zipimport<2>.
* Altri::

Porting a Python 3.12

* Modifiche nell’API di Python::

Modifiche all’API C

* Nuove Funzionalità: Nuove Funzionalità<2>.
* Porting a Python 3.12: Porting a Python 3 12<2>.
* Deprecato: Deprecato<2>.
* Rimosso: Rimosso<2>.

Deprecato

* Pending removal in Python 3.14: Pending removal in Python 3 14<4>.
* Pending removal in Python 3.15: Pending removal in Python 3 15<6>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<6>.
* Pending removal in future versions: Pending removal in future versions<6>.

What’s New In Python 3.11

* Summary – Release highlights: Summary – Release highlights<2>.
* New Features: New Features<3>.
* New Features Related to Type Hints::
* Other Language Changes: Other Language Changes<2>.
* Other CPython Implementation Changes::
* New Modules: New Modules<2>.
* Improved Modules: Improved Modules<2>.
* Optimizations: Optimizations<3>.
* Faster CPython::
* CPython bytecode changes: CPython bytecode changes<2>.
* Deprecated: Deprecated<2>.
* Pending Removal in Python 3.12: Pending Removal in Python 3 12.
* Removed: Removed<2>.
* Porting to Python 3.11: Porting to Python 3 11.
* Build Changes: Build Changes<2>.
* C API Changes: C API Changes<2>.
* Notable changes in 3.11.4: Notable changes in 3 11 4.
* Notable changes in 3.11.5: Notable changes in 3 11 5.

New Features

* PEP 657; Fine-grained error locations in tracebacks: PEP 657 Fine-grained error locations in tracebacks.
* PEP 654; Exception Groups and except*: PEP 654 Exception Groups and except*.
* PEP 678; Exceptions can be enriched with notes: PEP 678 Exceptions can be enriched with notes.
* Windows py.exe launcher improvements: Windows py exe launcher improvements.

New Features Related to Type Hints

* PEP 646; Variadic generics: PEP 646 Variadic generics.
* PEP 655; Marking individual TypedDict items as required or not-required: PEP 655 Marking individual TypedDict items as required or not-required.
* PEP 673; Self type: PEP 673 Self type.
* PEP 675; Arbitrary literal string type: PEP 675 Arbitrary literal string type.
* PEP 681; Data class transforms: PEP 681 Data class transforms.
* PEP 563 may not be the future::

Improved Modules

* asyncio: asyncio<6>.
* contextlib::
* dataclasses::
* datetime: datetime<2>.
* enum: enum<3>.
* fcntl::
* fractions: fractions<4>.
* functools: functools<2>.
* gzip: gzip<2>.
* hashlib: hashlib<2>.
* IDLE and idlelib::
* inspect: inspect<3>.
* locale: locale<3>.
* logging::
* math: math<3>.
* operator: operator<2>.
* os: os<4>.
* pathlib: pathlib<7>.
* re: re<4>.
* shutil: shutil<3>.
* socket: socket<2>.
* sqlite3: sqlite3<5>.
* string::
* sys: sys<4>.
* sysconfig: sysconfig<2>.
* tempfile: tempfile<3>.
* threading: threading<3>.
* time: time<2>.
* tkinter: tkinter<4>.
* traceback: traceback<2>.
* typing: typing<5>.
* unicodedata: unicodedata<4>.
* unittest: unittest<5>.
* venv: venv<2>.
* warnings: warnings<2>.
* zipfile: zipfile<2>.

Faster CPython

* Faster Startup::
* Faster Runtime::
* Misc::
* FAQ::
* About::

Faster Startup

* Frozen imports / Static code objects::

Faster Runtime

* Cheaper, lazy Python frames: Cheaper lazy Python frames.
* Inlined Python function calls::
* PEP 659; Specializing Adaptive Interpreter: PEP 659 Specializing Adaptive Interpreter.

FAQ

* How should I write my code to utilize these speedups?::
* Will CPython 3.11 use more memory?: Will CPython 3 11 use more memory?.
* I don’t see any speedups in my workload. Why?: I don’t see any speedups in my workload Why?.
* Is there a JIT compiler?::

CPython bytecode changes

* New opcodes::
* Replaced opcodes::
* Changed/removed opcodes::

Deprecated

* Language/Builtins::
* Modules::
* Standard Library::

C API Changes

* New Features: New Features<4>.
* Porting to Python 3.11: Porting to Python 3 11<2>.
* Deprecated: Deprecated<3>.
* Pending Removal in Python 3.12: Pending Removal in Python 3 12<2>.
* Removed: Removed<3>.

Notable changes in 3.11.4

* tarfile: tarfile<2>.

Notable changes in 3.11.5

* OpenSSL::

What’s New In Python 3.10

* Summary – Release highlights: Summary – Release highlights<3>.
* New Features: New Features<5>.
* New Features Related to Type Hints: New Features Related to Type Hints<2>.
* Other Language Changes: Other Language Changes<3>.
* New Modules: New Modules<3>.
* Improved Modules: Improved Modules<3>.
* Optimizations: Optimizations<4>.
* Deprecated: Deprecated<4>.
* Removed: Removed<4>.
* Porting to Python 3.10: Porting to Python 3 10.
* CPython bytecode changes: CPython bytecode changes<3>.
* Build Changes: Build Changes<3>.
* C API Changes: C API Changes<3>.
* Notable security feature in 3.10.7: Notable security feature in 3 10 7.
* Notable security feature in 3.10.8: Notable security feature in 3 10 8.
* Notable changes in 3.10.12: Notable changes in 3 10 12.

New Features

* Parenthesized context managers::
* Better error messages::
* PEP 626; Precise line numbers for debugging and other tools: PEP 626 Precise line numbers for debugging and other tools.
* PEP 634; Structural Pattern Matching: PEP 634 Structural Pattern Matching.
* Optional EncodingWarning and encoding="locale" option::

Better error messages

* SyntaxErrors::
* IndentationErrors::
* AttributeErrors::
* NameErrors::

PEP 634: Structural Pattern Matching

* Syntax and operations::
* Declarative approach::
* Simple pattern; match to a literal: Simple pattern match to a literal.
* Patterns with a literal and variable::
* Patterns and classes::
* Nested patterns::
* Complex patterns and the wildcard::
* Guard::
* Other Key Features::

Simple pattern: match to a literal

* Behavior without the wildcard::

Patterns and classes

* Patterns with positional parameters::

New Features Related to Type Hints

* PEP 604; New Type Union Operator: PEP 604 New Type Union Operator.
* PEP 612; Parameter Specification Variables: PEP 612 Parameter Specification Variables.
* PEP 613; TypeAlias: PEP 613 TypeAlias.
* PEP 647; User-Defined Type Guards: PEP 647 User-Defined Type Guards.

Improved Modules

* asyncio: asyncio<7>.
* argparse: argparse<4>.
* array: array<3>.
* asynchat, asyncore, smtpd: asynchat asyncore smtpd.
* base64: base64<3>.
* bdb: bdb<2>.
* bisect::
* codecs::
* collections.abc: collections abc.
* contextlib: contextlib<2>.
* curses: curses<2>.
* dataclasses: dataclasses<2>.
* distutils: distutils<2>.
* doctest: doctest<2>.
* encodings::
* enum: enum<4>.
* fileinput::
* faulthandler: faulthandler<2>.
* gc: gc<2>.
* glob: glob<2>.
* hashlib: hashlib<3>.
* hmac: hmac<2>.
* IDLE and idlelib: IDLE and idlelib<2>.
* importlib.metadata: importlib metadata<2>.
* inspect: inspect<4>.
* itertools: itertools<4>.
* linecache: linecache<2>.
* os: os<5>.
* os.path: os path<4>.
* pathlib: pathlib<8>.
* platform: platform<3>.
* pprint::
* py_compile::
* pyclbr::
* shelve::
* statistics: statistics<2>.
* site: site<2>.
* socket: socket<3>.
* ssl: ssl<4>.
* sqlite3: sqlite3<6>.
* sys: sys<5>.
* _thread::
* threading: threading<4>.
* traceback: traceback<3>.
* types: types<4>.
* typing: typing<6>.
* unittest: unittest<6>.
* urllib.parse: urllib parse.
* xml: xml<2>.
* zipimport: zipimport<3>.

dataclasses

* __slots__::
* Keyword-only fields::

Porting to Python 3.10

* Changes in the Python syntax::
* Changes in the Python API: Changes in the Python API<3>.
* Changes in the C API: Changes in the C API<3>.

C API Changes

* PEP 652; Maintaining the Stable ABI: PEP 652 Maintaining the Stable ABI.
* New Features: New Features<6>.
* Porting to Python 3.10: Porting to Python 3 10<2>.
* Deprecated: Deprecated<5>.
* Removed: Removed<5>.

Notable changes in 3.10.12

* tarfile: tarfile<3>.

What’s New In Python 3.9

* Summary – Release highlights: Summary – Release highlights<4>.
* You should check for DeprecationWarning in your code::
* New Features: New Features<7>.
* Other Language Changes: Other Language Changes<4>.
* New Modules: New Modules<4>.
* Improved Modules: Improved Modules<4>.
* Optimizations: Optimizations<5>.
* Deprecated: Deprecated<6>.
* Removed: Removed<6>.
* Porting to Python 3.9: Porting to Python 3 9.
* Build Changes: Build Changes<4>.
* C API Changes: C API Changes<4>.
* Notable changes in Python 3.9.1: Notable changes in Python 3 9 1.
* Notable changes in Python 3.9.2: Notable changes in Python 3 9 2.
* Notable changes in Python 3.9.3: Notable changes in Python 3 9 3.
* Notable changes in Python 3.9.5: Notable changes in Python 3 9 5.
* Notable security feature in 3.9.14: Notable security feature in 3 9 14.
* Notable changes in 3.9.17: Notable changes in 3 9 17.

New Features

* Dictionary Merge & Update Operators::
* New String Methods to Remove Prefixes and Suffixes::
* Type Hinting Generics in Standard Collections::
* New Parser::

New Modules

* zoneinfo::
* graphlib: graphlib<2>.

Improved Modules

* ast: ast<4>.
* asyncio: asyncio<8>.
* compileall: compileall<2>.
* concurrent.futures: concurrent futures<3>.
* curses: curses<3>.
* datetime: datetime<3>.
* distutils: distutils<3>.
* fcntl: fcntl<2>.
* ftplib: ftplib<2>.
* gc: gc<3>.
* hashlib: hashlib<4>.
* http: http<2>.
* IDLE and idlelib: IDLE and idlelib<3>.
* imaplib: imaplib<2>.
* importlib: importlib<3>.
* inspect: inspect<5>.
* ipaddress: ipaddress<2>.
* math: math<4>.
* multiprocessing: multiprocessing<3>.
* nntplib::
* os: os<6>.
* pathlib: pathlib<9>.
* pdb: pdb<5>.
* poplib::
* pprint: pprint<2>.
* pydoc: pydoc<2>.
* random: random<3>.
* signal::
* smtplib::
* socket: socket<4>.
* time: time<3>.
* sys: sys<6>.
* tracemalloc::
* typing: typing<7>.
* unicodedata: unicodedata<5>.
* venv: venv<3>.
* xml: xml<3>.

Porting to Python 3.9

* Changes in the Python API: Changes in the Python API<4>.
* Changes in the C API: Changes in the C API<4>.
* CPython bytecode changes: CPython bytecode changes<4>.

C API Changes

* New Features: New Features<8>.
* Porting to Python 3.9: Porting to Python 3 9<2>.
* Removed: Removed<7>.

Notable changes in Python 3.9.1

* typing: typing<8>.
* macOS 11.0 (Big Sur) and Apple Silicon Mac support: macOS 11 0 Big Sur and Apple Silicon Mac support.

Notable changes in Python 3.9.2

* collections.abc: collections abc<2>.
* urllib.parse: urllib parse<2>.

Notable changes in Python 3.9.5

* urllib.parse: urllib parse<3>.

Notable changes in 3.9.17

* tarfile: tarfile<4>.

What’s New In Python 3.8

* Summary – Release highlights: Summary – Release highlights<5>.
* New Features: New Features<9>.
* Other Language Changes: Other Language Changes<5>.
* New Modules: New Modules<5>.
* Improved Modules: Improved Modules<5>.
* Optimizations: Optimizations<6>.
* Build and C API Changes::
* Deprecated: Deprecated<7>.
* API and Feature Removals::
* Porting to Python 3.8: Porting to Python 3 8.
* Notable changes in Python 3.8.1: Notable changes in Python 3 8 1.
* Notable changes in Python 3.8.2: Notable changes in Python 3 8 2.
* Notable changes in Python 3.8.3: Notable changes in Python 3 8 3.
* Notable changes in Python 3.8.8: Notable changes in Python 3 8 8.
* Notable changes in Python 3.8.9: Notable changes in Python 3 8 9.
* Notable changes in Python 3.8.10: Notable changes in Python 3 8 10.
* Notable changes in Python 3.8.10: Notable changes in Python 3 8 10<2>.
* Notable changes in Python 3.8.12: Notable changes in Python 3 8 12.
* Notable security feature in 3.8.14: Notable security feature in 3 8 14.
* Notable changes in 3.8.17: Notable changes in 3 8 17.

New Features

* Assignment expressions::
* Positional-only parameters::
* Parallel filesystem cache for compiled bytecode files::
* Debug build uses the same ABI as release build::
* f-strings support = for self-documenting expressions and debugging::
* PEP 578; Python Runtime Audit Hooks: PEP 578 Python Runtime Audit Hooks.
* PEP 587; Python Initialization Configuration: PEP 587 Python Initialization Configuration.
* PEP 590; Vectorcall; a fast calling protocol for CPython: PEP 590 Vectorcall a fast calling protocol for CPython.
* Pickle protocol 5 with out-of-band data buffers::

Improved Modules

* ast: ast<5>.
* asyncio: asyncio<9>.
* builtins: builtins<2>.
* collections::
* cProfile::
* csv: csv<2>.
* curses: curses<4>.
* ctypes: ctypes<3>.
* datetime: datetime<4>.
* functools: functools<3>.
* gc: gc<4>.
* gettext::
* gzip: gzip<3>.
* IDLE and idlelib: IDLE and idlelib<4>.
* inspect: inspect<6>.
* io: io<5>.
* itertools: itertools<5>.
* json.tool: json tool.
* logging: logging<2>.
* math: math<5>.
* mmap: mmap<2>.
* multiprocessing: multiprocessing<4>.
* os: os<7>.
* os.path: os path<5>.
* pathlib: pathlib<10>.
* pickle: pickle<2>.
* plistlib::
* pprint: pprint<3>.
* py_compile: py_compile<2>.
* shlex::
* shutil: shutil<4>.
* socket: socket<5>.
* ssl: ssl<5>.
* statistics: statistics<3>.
* sys: sys<7>.
* tarfile: tarfile<5>.
* threading: threading<5>.
* tokenize: tokenize<2>.
* tkinter: tkinter<5>.
* time: time<4>.
* typing: typing<9>.
* unicodedata: unicodedata<6>.
* unittest: unittest<7>.
* venv: venv<4>.
* weakref::
* xml: xml<4>.
* xmlrpc::

Porting to Python 3.8

* Changes in Python behavior::
* Changes in the Python API: Changes in the Python API<5>.
* Changes in the C API: Changes in the C API<5>.
* CPython bytecode changes: CPython bytecode changes<5>.
* Demos and Tools::

Notable changes in Python 3.8.10

* macOS 11.0 (Big Sur) and Apple Silicon Mac support: macOS 11 0 Big Sur and Apple Silicon Mac support<2>.

Notable changes in Python 3.8.10

* urllib.parse: urllib parse<4>.

Notable changes in Python 3.8.12

* Changes in the Python API: Changes in the Python API<6>.

Notable changes in 3.8.17

* tarfile: tarfile<6>.

What’s New In Python 3.7

* Summary – Release Highlights: Summary – Release Highlights<2>.
* New Features: New Features<10>.
* Other Language Changes: Other Language Changes<6>.
* New Modules: New Modules<6>.
* Improved Modules: Improved Modules<6>.
* C API Changes: C API Changes<5>.
* Build Changes: Build Changes<5>.
* Optimizations: Optimizations<7>.
* Other CPython Implementation Changes: Other CPython Implementation Changes<2>.
* Deprecated Python Behavior::
* Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods.
* Deprecated functions and types of the C API::
* Platform Support Removals::
* API and Feature Removals: API and Feature Removals<2>.
* Module Removals::
* Windows-only Changes::
* Porting to Python 3.7: Porting to Python 3 7.
* Notable changes in Python 3.7.1: Notable changes in Python 3 7 1.
* Notable changes in Python 3.7.2: Notable changes in Python 3 7 2.
* Notable changes in Python 3.7.6: Notable changes in Python 3 7 6.
* Notable changes in Python 3.7.10: Notable changes in Python 3 7 10.
* Notable changes in Python 3.7.11: Notable changes in Python 3 7 11.
* Notable security feature in 3.7.14: Notable security feature in 3 7 14.

New Features

* PEP 563; Postponed Evaluation of Annotations: PEP 563 Postponed Evaluation of Annotations.
* PEP 538; Legacy C Locale Coercion: PEP 538 Legacy C Locale Coercion.
* PEP 540; Forced UTF-8 Runtime Mode: PEP 540 Forced UTF-8 Runtime Mode.
* PEP 553; Built-in breakpoint(): PEP 553 Built-in breakpoint.
* PEP 539; New C API for Thread-Local Storage: PEP 539 New C API for Thread-Local Storage.
* PEP 562; Customization of Access to Module Attributes: PEP 562 Customization of Access to Module Attributes.
* PEP 564; New Time Functions With Nanosecond Resolution: PEP 564 New Time Functions With Nanosecond Resolution.
* PEP 565; Show DeprecationWarning in __main__: PEP 565 Show DeprecationWarning in __main__.
* PEP 560; Core Support for typing module and Generic Types: PEP 560 Core Support for typing module and Generic Types.
* PEP 552; Hash-based .pyc Files: PEP 552 Hash-based pyc Files.
* PEP 545; Python Documentation Translations: PEP 545 Python Documentation Translations.
* Python Development Mode (-X dev): Python Development Mode -X dev.

New Modules

* contextvars: contextvars<2>.
* dataclasses: dataclasses<3>.
* importlib.resources: importlib resources<2>.

Improved Modules

* argparse: argparse<5>.
* asyncio: asyncio<10>.
* binascii::
* calendar: calendar<3>.
* collections: collections<2>.
* compileall: compileall<3>.
* concurrent.futures: concurrent futures<4>.
* contextlib: contextlib<3>.
* cProfile: cProfile<2>.
* crypt::
* datetime: datetime<5>.
* dbm: dbm<2>.
* decimal: decimal<2>.
* dis: dis<4>.
* distutils: distutils<4>.
* enum: enum<5>.
* functools: functools<4>.
* gc: gc<5>.
* hmac: hmac<3>.
* http.client: http client.
* http.server: http server.
* idlelib and IDLE::
* importlib: importlib<4>.
* io: io<6>.
* ipaddress: ipaddress<3>.
* itertools: itertools<6>.
* locale: locale<4>.
* logging: logging<3>.
* math: math<6>.
* mimetypes: mimetypes<3>.
* msilib::
* multiprocessing: multiprocessing<5>.
* os: os<8>.
* pathlib: pathlib<11>.
* pdb: pdb<6>.
* py_compile: py_compile<3>.
* pydoc: pydoc<3>.
* queue: queue<2>.
* re: re<5>.
* signal: signal<2>.
* socket: socket<6>.
* socketserver::
* sqlite3: sqlite3<7>.
* ssl: ssl<6>.
* string: string<2>.
* subprocess: subprocess<2>.
* sys: sys<8>.
* time: time<5>.
* tkinter: tkinter<6>.
* tracemalloc: tracemalloc<2>.
* types: types<5>.
* unicodedata: unicodedata<7>.
* unittest: unittest<8>.
* unittest.mock: unittest mock.
* urllib.parse: urllib parse<5>.
* uu::
* uuid: uuid<4>.
* warnings: warnings<3>.
* xml: xml<5>.
* xml.etree: xml etree.
* xmlrpc.server: xmlrpc server.
* zipapp::
* zipfile: zipfile<3>.

Deprecated Python modules, functions and methods

* aifc::
* asyncio: asyncio<11>.
* collections: collections<3>.
* dbm: dbm<3>.
* enum: enum<6>.
* gettext: gettext<2>.
* importlib: importlib<5>.
* locale: locale<5>.
* macpath::
* threading: threading<6>.
* socket: socket<7>.
* ssl: ssl<7>.
* sunau::
* sys: sys<9>.
* wave::

Porting to Python 3.7

* Changes in Python Behavior::
* Changes in the Python API: Changes in the Python API<7>.
* Changes in the C API: Changes in the C API<6>.
* CPython bytecode changes: CPython bytecode changes<6>.
* Windows-only Changes: Windows-only Changes<2>.
* Other CPython implementation changes::

What’s New In Python 3.6

* Summary – Release highlights: Summary – Release highlights<6>.
* New Features: New Features<11>.
* Other Language Changes: Other Language Changes<7>.
* New Modules: New Modules<7>.
* Improved Modules: Improved Modules<7>.
* Optimizations: Optimizations<8>.
* Build and C API Changes: Build and C API Changes<2>.
* Other Improvements::
* Deprecated: Deprecated<8>.
* Removed: Removed<8>.
* Porting to Python 3.6: Porting to Python 3 6.
* Notable changes in Python 3.6.2: Notable changes in Python 3 6 2.
* Notable changes in Python 3.6.4: Notable changes in Python 3 6 4.
* Notable changes in Python 3.6.5: Notable changes in Python 3 6 5.
* Notable changes in Python 3.6.7: Notable changes in Python 3 6 7.
* Notable changes in Python 3.6.10: Notable changes in Python 3 6 10.
* Notable changes in Python 3.6.13: Notable changes in Python 3 6 13.
* Notable changes in Python 3.6.14: Notable changes in Python 3 6 14.

New Features

* PEP 498; Formatted string literals: PEP 498 Formatted string literals.
* PEP 526; Syntax for variable annotations: PEP 526 Syntax for variable annotations.
* PEP 515; Underscores in Numeric Literals: PEP 515 Underscores in Numeric Literals.
* PEP 525; Asynchronous Generators: PEP 525 Asynchronous Generators.
* PEP 530; Asynchronous Comprehensions: PEP 530 Asynchronous Comprehensions.
* PEP 487; Simpler customization of class creation: PEP 487 Simpler customization of class creation.
* PEP 487; Descriptor Protocol Enhancements: PEP 487 Descriptor Protocol Enhancements.
* PEP 519; Adding a file system path protocol: PEP 519 Adding a file system path protocol.
* PEP 495; Local Time Disambiguation: PEP 495 Local Time Disambiguation.
* PEP 529; Change Windows filesystem encoding to UTF-8: PEP 529 Change Windows filesystem encoding to UTF-8.
* PEP 528; Change Windows console encoding to UTF-8: PEP 528 Change Windows console encoding to UTF-8.
* PEP 520; Preserving Class Attribute Definition Order: PEP 520 Preserving Class Attribute Definition Order.
* PEP 468; Preserving Keyword Argument Order: PEP 468 Preserving Keyword Argument Order.
* New dict implementation::
* PEP 523; Adding a frame evaluation API to CPython: PEP 523 Adding a frame evaluation API to CPython.
* PYTHONMALLOC environment variable::
* DTrace and SystemTap probing support::

New Modules

* secrets::

Improved Modules

* array: array<4>.
* ast: ast<6>.
* asyncio: asyncio<12>.
* binascii: binascii<2>.
* cmath::
* collections: collections<4>.
* concurrent.futures: concurrent futures<5>.
* contextlib: contextlib<4>.
* datetime: datetime<6>.
* decimal: decimal<3>.
* distutils: distutils<5>.
* email: email<3>.
* encodings: encodings<2>.
* enum: enum<7>.
* faulthandler: faulthandler<3>.
* fileinput: fileinput<2>.
* hashlib: hashlib<5>.
* http.client: http client<2>.
* idlelib and IDLE: idlelib and IDLE<2>.
* importlib: importlib<6>.
* inspect: inspect<7>.
* json: json<2>.
* logging: logging<4>.
* math: math<7>.
* multiprocessing: multiprocessing<6>.
* os: os<9>.
* pathlib: pathlib<12>.
* pdb: pdb<7>.
* pickle: pickle<3>.
* pickletools::
* pydoc: pydoc<4>.
* random: random<4>.
* re: re<6>.
* readline::
* rlcompleter::
* shlex: shlex<2>.
* site: site<3>.
* sqlite3: sqlite3<8>.
* socket: socket<8>.
* socketserver: socketserver<2>.
* ssl: ssl<8>.
* statistics: statistics<4>.
* struct: struct<2>.
* subprocess: subprocess<3>.
* sys: sys<10>.
* telnetlib::
* time: time<6>.
* timeit::
* tkinter: tkinter<7>.
* traceback: traceback<4>.
* tracemalloc: tracemalloc<3>.
* typing: typing<10>.
* unicodedata: unicodedata<8>.
* unittest.mock: unittest mock<2>.
* urllib.request: urllib request.
* urllib.robotparser: urllib robotparser.
* venv: venv<5>.
* warnings: warnings<4>.
* winreg::
* winsound::
* xmlrpc.client: xmlrpc client.
* zipfile: zipfile<4>.
* zlib: zlib<2>.

Deprecated

* New Keywords::
* Deprecated Python behavior::
* Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<2>.
* xml: xml<6>.
* Deprecated functions and types of the C API: Deprecated functions and types of the C API<2>.
* Deprecated Build Options::

Deprecated Python modules, functions and methods

* asynchat::
* asyncore::
* dbm: dbm<4>.
* distutils: distutils<6>.
* grp::
* importlib: importlib<7>.
* os: os<10>.
* re: re<7>.
* ssl: ssl<9>.
* tkinter: tkinter<8>.
* venv: venv<6>.

Removed

* API and Feature Removals: API and Feature Removals<3>.

Porting to Python 3.6

* Changes in “python” Command Behavior::
* Changes in the Python API: Changes in the Python API<8>.
* Changes in the C API: Changes in the C API<7>.
* CPython bytecode changes: CPython bytecode changes<7>.

Notable changes in Python 3.6.2

* New make regen-all build target::
* Removal of make touch build target::

What’s New In Python 3.5

* Summary – Release highlights: Summary – Release highlights<7>.
* New Features: New Features<12>.
* Other Language Changes: Other Language Changes<8>.
* New Modules: New Modules<8>.
* Improved Modules: Improved Modules<8>.
* Other module-level changes::
* Optimizations: Optimizations<9>.
* Build and C API Changes: Build and C API Changes<3>.
* Deprecated: Deprecated<9>.
* Removed: Removed<9>.
* Porting to Python 3.5: Porting to Python 3 5.
* Notable changes in Python 3.5.4: Notable changes in Python 3 5 4.

New Features

* PEP 492 - Coroutines with async and await syntax::
* PEP 465 - A dedicated infix operator for matrix multiplication::
* PEP 448 - Additional Unpacking Generalizations::
* PEP 461 - percent formatting support for bytes and bytearray::
* PEP 484 - Type Hints::
* PEP 471 - os.scandir() function – a better and faster directory iterator: PEP 471 - os scandir function – a better and faster directory iterator.
* PEP 475; Retry system calls failing with EINTR: PEP 475 Retry system calls failing with EINTR.
* PEP 479; Change StopIteration handling inside generators: PEP 479 Change StopIteration handling inside generators.
* PEP 485; A function for testing approximate equality: PEP 485 A function for testing approximate equality.
* PEP 486; Make the Python Launcher aware of virtual environments: PEP 486 Make the Python Launcher aware of virtual environments.
* PEP 488; Elimination of PYO files: PEP 488 Elimination of PYO files.
* PEP 489; Multi-phase extension module initialization: PEP 489 Multi-phase extension module initialization.

New Modules

* typing: typing<11>.
* zipapp: zipapp<2>.

Improved Modules

* argparse: argparse<6>.
* asyncio: asyncio<13>.
* bz2::
* cgi::
* cmath: cmath<2>.
* code::
* collections: collections<5>.
* collections.abc: collections abc<3>.
* compileall: compileall<4>.
* concurrent.futures: concurrent futures<6>.
* configparser: configparser<5>.
* contextlib: contextlib<5>.
* csv: csv<3>.
* curses: curses<5>.
* dbm: dbm<5>.
* difflib: difflib<3>.
* distutils: distutils<7>.
* doctest: doctest<3>.
* email: email<4>.
* enum: enum<8>.
* faulthandler: faulthandler<4>.
* functools: functools<5>.
* glob: glob<3>.
* gzip: gzip<4>.
* heapq: heapq<2>.
* http: http<3>.
* http.client: http client<3>.
* idlelib and IDLE: idlelib and IDLE<3>.
* imaplib: imaplib<3>.
* imghdr::
* importlib: importlib<8>.
* inspect: inspect<8>.
* io: io<7>.
* ipaddress: ipaddress<4>.
* json: json<3>.
* linecache: linecache<3>.
* locale: locale<6>.
* logging: logging<5>.
* lzma::
* math: math<8>.
* multiprocessing: multiprocessing<7>.
* operator: operator<3>.
* os: os<11>.
* pathlib: pathlib<13>.
* pickle: pickle<4>.
* poplib: poplib<2>.
* re: re<8>.
* readline: readline<2>.
* selectors::
* shutil: shutil<5>.
* signal: signal<3>.
* smtpd: smtpd<2>.
* smtplib: smtplib<2>.
* sndhdr::
* socket: socket<9>.
* ssl: ssl<10>.
* sqlite3: sqlite3<9>.
* subprocess: subprocess<4>.
* sys: sys<11>.
* sysconfig: sysconfig<3>.
* tarfile: tarfile<7>.
* threading: threading<7>.
* time: time<7>.
* timeit: timeit<2>.
* tkinter: tkinter<9>.
* traceback: traceback<5>.
* types: types<6>.
* unicodedata: unicodedata<9>.
* unittest: unittest<9>.
* unittest.mock: unittest mock<3>.
* urllib: urllib<4>.
* wsgiref::
* xmlrpc: xmlrpc<2>.
* xml.sax: xml sax.
* zipfile: zipfile<5>.

ssl

* Memory BIO Support::
* Application-Layer Protocol Negotiation Support::
* Other Changes::

Deprecated

* New Keywords: New Keywords<2>.
* Deprecated Python Behavior: Deprecated Python Behavior<2>.
* Unsupported Operating Systems::
* Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<3>.

Removed

* API and Feature Removals: API and Feature Removals<4>.

Porting to Python 3.5

* Changes in Python behavior: Changes in Python behavior<2>.
* Changes in the Python API: Changes in the Python API<9>.
* Changes in the C API: Changes in the C API<8>.

Notable changes in Python 3.5.4

* New make regen-all build target: New make regen-all build target<2>.
* Removal of make touch build target: Removal of make touch build target<2>.

What’s New In Python 3.4

* Summary – Release Highlights: Summary – Release Highlights<3>.
* New Features: New Features<13>.
* New Modules: New Modules<9>.
* Improved Modules: Improved Modules<9>.
* CPython Implementation Changes::
* Deprecated: Deprecated<10>.
* Removed: Removed<10>.
* Porting to Python 3.4: Porting to Python 3 4.
* Changed in 3.4.3: Changed in 3 4 3.

New Features

* PEP 453; Explicit Bootstrapping of PIP in Python Installations: PEP 453 Explicit Bootstrapping of PIP in Python Installations.
* PEP 446; Newly Created File Descriptors Are Non-Inheritable: PEP 446 Newly Created File Descriptors Are Non-Inheritable.
* Improvements to Codec Handling::
* PEP 451; A ModuleSpec Type for the Import System: PEP 451 A ModuleSpec Type for the Import System.
* Other Language Changes: Other Language Changes<9>.

PEP 453: Explicit Bootstrapping of PIP in Python Installations

* Bootstrapping pip By Default::
* Documentation Changes::

New Modules

* asyncio: asyncio<14>.
* ensurepip: ensurepip<2>.
* enum: enum<9>.
* pathlib: pathlib<14>.
* selectors: selectors<2>.
* statistics: statistics<5>.
* tracemalloc: tracemalloc<4>.

Improved Modules

* abc::
* aifc: aifc<2>.
* argparse: argparse<7>.
* audioop::
* base64: base64<4>.
* collections: collections<6>.
* colorsys::
* contextlib: contextlib<6>.
* dbm: dbm<6>.
* dis: dis<5>.
* doctest: doctest<4>.
* email: email<5>.
* filecmp::
* functools: functools<6>.
* gc: gc<6>.
* glob: glob<4>.
* hashlib: hashlib<6>.
* hmac: hmac<4>.
* html::
* http: http<4>.
* idlelib and IDLE: idlelib and IDLE<4>.
* importlib: importlib<9>.
* inspect: inspect<9>.
* ipaddress: ipaddress<5>.
* logging: logging<6>.
* marshal: marshal<2>.
* mmap: mmap<3>.
* multiprocessing: multiprocessing<8>.
* operator: operator<4>.
* os: os<12>.
* pdb: pdb<8>.
* pickle: pickle<5>.
* plistlib: plistlib<2>.
* poplib: poplib<3>.
* pprint: pprint<4>.
* pty: pty<2>.
* pydoc: pydoc<5>.
* re: re<9>.
* resource::
* select::
* shelve: shelve<2>.
* shutil: shutil<6>.
* smtpd: smtpd<3>.
* smtplib: smtplib<3>.
* socket: socket<10>.
* sqlite3: sqlite3<10>.
* ssl: ssl<11>.
* stat::
* struct: struct<3>.
* subprocess: subprocess<5>.
* sunau: sunau<2>.
* sys: sys<12>.
* tarfile: tarfile<8>.
* textwrap: textwrap<2>.
* threading: threading<8>.
* traceback: traceback<6>.
* types: types<7>.
* urllib: urllib<5>.
* unittest: unittest<10>.
* venv: venv<7>.
* wave: wave<2>.
* weakref: weakref<2>.
* xml.etree: xml etree<2>.
* zipfile: zipfile<6>.

CPython Implementation Changes

* PEP 445; Customization of CPython Memory Allocators: PEP 445 Customization of CPython Memory Allocators.
* PEP 442; Safe Object Finalization: PEP 442 Safe Object Finalization.
* PEP 456; Secure and Interchangeable Hash Algorithm: PEP 456 Secure and Interchangeable Hash Algorithm.
* PEP 436; Argument Clinic: PEP 436 Argument Clinic.
* Other Build and C API Changes::
* Other Improvements: Other Improvements<2>.
* Significant Optimizations::

Deprecated

* Deprecations in the Python API::
* Deprecated Features::

Removed

* Operating Systems No Longer Supported::
* API and Feature Removals: API and Feature Removals<5>.
* Code Cleanups::

Porting to Python 3.4

* Changes in “python” Command Behavior: Changes in “python” Command Behavior<2>.
* Changes in the Python API: Changes in the Python API<10>.
* Changes in the C API: Changes in the C API<9>.

Changed in 3.4.3

* PEP 476; Enabling certificate verification by default for stdlib http clients: PEP 476 Enabling certificate verification by default for stdlib http clients.

What’s New In Python 3.3

* Summary – Release highlights: Summary – Release highlights<8>.
* PEP 405; Virtual Environments: PEP 405 Virtual Environments.
* PEP 420; Implicit Namespace Packages: PEP 420 Implicit Namespace Packages.
* PEP 3118; New memoryview implementation and buffer protocol documentation: PEP 3118 New memoryview implementation and buffer protocol documentation.
* PEP 393; Flexible String Representation: PEP 393 Flexible String Representation.
* PEP 397; Python Launcher for Windows: PEP 397 Python Launcher for Windows.
* PEP 3151; Reworking the OS and IO exception hierarchy: PEP 3151 Reworking the OS and IO exception hierarchy.
* PEP 380; Syntax for Delegating to a Subgenerator: PEP 380 Syntax for Delegating to a Subgenerator.
* PEP 409; Suppressing exception context: PEP 409 Suppressing exception context.
* PEP 414; Explicit Unicode literals: PEP 414 Explicit Unicode literals.
* PEP 3155; Qualified name for classes and functions: PEP 3155 Qualified name for classes and functions.
* PEP 412; Key-Sharing Dictionary: PEP 412 Key-Sharing Dictionary.
* PEP 362; Function Signature Object: PEP 362 Function Signature Object.
* PEP 421; Adding sys.implementation: PEP 421 Adding sys implementation.
* Using importlib as the Implementation of Import::
* Other Language Changes: Other Language Changes<10>.
* A Finer-Grained Import Lock::
* Builtin functions and types::
* New Modules: New Modules<10>.
* Improved Modules: Improved Modules<10>.
* Optimizations: Optimizations<10>.
* Build and C API Changes: Build and C API Changes<4>.
* Deprecated: Deprecated<11>.
* Porting to Python 3.3: Porting to Python 3 3.

PEP 3118: New memoryview implementation and buffer protocol documentation

* Features::
* API changes::

PEP 393: Flexible String Representation

* Functionality::
* Performance and resource usage::

PEP 421: Adding sys.implementation

* SimpleNamespace::

Using importlib as the Implementation of Import

* New APIs::
* Visible Changes::

New Modules

* faulthandler: faulthandler<5>.
* ipaddress: ipaddress<6>.
* lzma: lzma<2>.

Improved Modules

* abc: abc<2>.
* array: array<5>.
* base64: base64<5>.
* binascii: binascii<3>.
* bz2: bz2<2>.
* codecs: codecs<2>.
* collections: collections<7>.
* contextlib: contextlib<7>.
* crypt: crypt<2>.
* curses: curses<6>.
* datetime: datetime<7>.
* decimal: decimal<4>.
* email: email<6>.
* ftplib: ftplib<3>.
* functools: functools<7>.
* gc: gc<7>.
* hmac: hmac<5>.
* http: http<5>.
* html: html<2>.
* imaplib: imaplib<4>.
* inspect: inspect<10>.
* io: io<8>.
* itertools: itertools<7>.
* logging: logging<7>.
* math: math<9>.
* mmap: mmap<4>.
* multiprocessing: multiprocessing<9>.
* nntplib: nntplib<2>.
* os: os<13>.
* pdb: pdb<9>.
* pickle: pickle<6>.
* pydoc: pydoc<6>.
* re: re<10>.
* sched::
* select: select<2>.
* shlex: shlex<3>.
* shutil: shutil<7>.
* signal: signal<4>.
* smtpd: smtpd<4>.
* smtplib: smtplib<4>.
* socket: socket<11>.
* socketserver: socketserver<3>.
* sqlite3: sqlite3<11>.
* ssl: ssl<12>.
* stat: stat<2>.
* struct: struct<4>.
* subprocess: subprocess<6>.
* sys: sys<13>.
* tarfile: tarfile<9>.
* tempfile: tempfile<4>.
* textwrap: textwrap<3>.
* threading: threading<9>.
* time: time<8>.
* types: types<8>.
* unittest: unittest<11>.
* urllib: urllib<6>.
* webbrowser: webbrowser<4>.
* xml.etree.ElementTree: xml etree ElementTree<2>.
* zlib: zlib<3>.

decimal

* Features: Features<2>.
* API changes: API changes<2>.

email

* Policy Framework::
* Provisional Policy with New Header API::
* Other API Changes::

Deprecated

* Unsupported Operating Systems: Unsupported Operating Systems<2>.
* Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<4>.
* Deprecated functions and types of the C API: Deprecated functions and types of the C API<3>.
* Deprecated features::

Porting to Python 3.3

* Porting Python code::
* Porting C code::
* Building C extensions::
* Command Line Switch Changes::

What’s New In Python 3.2

* PEP 384; Defining a Stable ABI: PEP 384 Defining a Stable ABI.
* PEP 389; Argparse Command Line Parsing Module: PEP 389 Argparse Command Line Parsing Module.
* PEP 391; Dictionary Based Configuration for Logging: PEP 391 Dictionary Based Configuration for Logging.
* PEP 3148; The concurrent.futures module: PEP 3148 The concurrent futures module.
* PEP 3147; PYC Repository Directories: PEP 3147 PYC Repository Directories.
* PEP 3149; ABI Version Tagged .so Files: PEP 3149 ABI Version Tagged so Files.
* PEP 3333; Python Web Server Gateway Interface v1.0.1: PEP 3333 Python Web Server Gateway Interface v1 0 1.
* Other Language Changes: Other Language Changes<11>.
* New, Improved, and Deprecated Modules: New Improved and Deprecated Modules.
* Multi-threading::
* Optimizations: Optimizations<11>.
* Unicode::
* Codecs::
* Documentation::
* IDLE::
* Code Repository::
* Build and C API Changes: Build and C API Changes<5>.
* Porting to Python 3.2: Porting to Python 3 2.

New, Improved, and Deprecated Modules

* email: email<7>.
* elementtree::
* functools: functools<8>.
* itertools: itertools<8>.
* collections: collections<8>.
* threading: threading<10>.
* datetime and time::
* math: math<10>.
* abc: abc<3>.
* io: io<9>.
* reprlib::
* logging: logging<8>.
* csv: csv<4>.
* contextlib: contextlib<8>.
* decimal and fractions::
* ftp::
* popen::
* select: select<3>.
* gzip and zipfile::
* tarfile: tarfile<10>.
* hashlib: hashlib<7>.
* ast: ast<7>.
* os: os<14>.
* shutil: shutil<8>.
* sqlite3: sqlite3<12>.
* html: html<3>.
* socket: socket<12>.
* ssl: ssl<13>.
* nntp::
* certificates::
* imaplib: imaplib<5>.
* http.client: http client<4>.
* unittest: unittest<12>.
* random: random<5>.
* poplib: poplib<4>.
* asyncore: asyncore<2>.
* tempfile: tempfile<5>.
* inspect: inspect<11>.
* pydoc: pydoc<7>.
* dis: dis<6>.
* dbm: dbm<7>.
* ctypes: ctypes<4>.
* site: site<4>.
* sysconfig: sysconfig<4>.
* pdb: pdb<10>.
* configparser: configparser<6>.
* urllib.parse: urllib parse<6>.
* mailbox::
* turtledemo::

What’s New In Python 3.1

* PEP 372; Ordered Dictionaries: PEP 372 Ordered Dictionaries.
* PEP 378; Format Specifier for Thousands Separator: PEP 378 Format Specifier for Thousands Separator.
* Other Language Changes: Other Language Changes<12>.
* New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<2>.
* Optimizations: Optimizations<12>.
* IDLE: IDLE<2>.
* Build and C API Changes: Build and C API Changes<6>.
* Porting to Python 3.1: Porting to Python 3 1.

What’s New In Python 3.0

* Common Stumbling Blocks::
* Overview Of Syntax Changes::
* Changes Already Present In Python 2.6: Changes Already Present In Python 2 6.
* Library Changes::
* PEP 3101; A New Approach To String Formatting: PEP 3101 A New Approach To String Formatting.
* Changes To Exceptions::
* Miscellaneous Other Changes::
* Build and C API Changes: Build and C API Changes<7>.
* Performance::
* Porting To Python 3.0: Porting To Python 3 0.

Common Stumbling Blocks

* Print Is A Function::
* Views And Iterators Instead Of Lists::
* Ordering Comparisons::
* Integers::
* Text Vs. Data Instead Of Unicode Vs. 8-bit: Text Vs Data Instead Of Unicode Vs 8-bit.

Overview Of Syntax Changes

* New Syntax::
* Changed Syntax::
* Removed Syntax::

Miscellaneous Other Changes

* Operators And Special Methods::
* Builtins::

What’s New in Python 2.7

* The Future for Python 2.x: The Future for Python 2 x.
* Changes to the Handling of Deprecation Warnings::
* Python 3.1 Features: Python 3 1 Features.
* PEP 372; Adding an Ordered Dictionary to collections: PEP 372 Adding an Ordered Dictionary to collections.
* PEP 378; Format Specifier for Thousands Separator: PEP 378 Format Specifier for Thousands Separator<2>.
* PEP 389; The argparse Module for Parsing Command Lines: PEP 389 The argparse Module for Parsing Command Lines.
* PEP 391; Dictionary-Based Configuration For Logging: PEP 391 Dictionary-Based Configuration For Logging.
* PEP 3106; Dictionary Views: PEP 3106 Dictionary Views.
* PEP 3137; The memoryview Object: PEP 3137 The memoryview Object.
* Other Language Changes: Other Language Changes<13>.
* New and Improved Modules::
* Build and C API Changes: Build and C API Changes<8>.
* Other Changes and Fixes::
* Porting to Python 2.7: Porting to Python 2 7.
* New Features Added to Python 2.7 Maintenance Releases: New Features Added to Python 2 7 Maintenance Releases.
* Acknowledgements::

Other Language Changes

* Interpreter Changes::
* Optimizations: Optimizations<13>.

New and Improved Modules

* New module; importlib: New module importlib.
* New module; sysconfig: New module sysconfig.
* ttk; Themed Widgets for Tk: ttk Themed Widgets for Tk.
* Updated module; unittest: Updated module unittest.
* Updated module; ElementTree 1.3: Updated module ElementTree 1 3.

Build and C API Changes

* Capsules::
* Port-Specific Changes; Windows: Port-Specific Changes Windows.
* Port-Specific Changes; Mac OS X: Port-Specific Changes Mac OS X.
* Port-Specific Changes; FreeBSD: Port-Specific Changes FreeBSD.

New Features Added to Python 2.7 Maintenance Releases

* Two new environment variables for debug mode::
* PEP 434; IDLE Enhancement Exception for All Branches: PEP 434 IDLE Enhancement Exception for All Branches.
* PEP 466; Network Security Enhancements for Python 2.7: PEP 466 Network Security Enhancements for Python 2 7.
* PEP 477; Backport ensurepip (PEP 453) to Python 2.7: PEP 477 Backport ensurepip PEP 453 to Python 2 7.
* PEP 476; Enabling certificate verification by default for stdlib http clients: PEP 476 Enabling certificate verification by default for stdlib http clients<2>.
* PEP 493; HTTPS verification migration tools for Python 2.7: PEP 493 HTTPS verification migration tools for Python 2 7.
* New make regen-all build target: New make regen-all build target<3>.
* Removal of make touch build target: Removal of make touch build target<3>.

PEP 477: Backport ensurepip (PEP 453) to Python 2.7

* Bootstrapping pip By Default: Bootstrapping pip By Default<2>.
* Documentation Changes: Documentation Changes<2>.

What’s New in Python 2.6

* Python 3.0: Python 3 0.
* Changes to the Development Process::
* PEP 343; The “with” statement: PEP 343 The “with” statement.
* PEP 366; Explicit Relative Imports From a Main Module: PEP 366 Explicit Relative Imports From a Main Module.
* PEP 370; Per-user site-packages Directory: PEP 370 Per-user site-packages Directory.
* PEP 371; The multiprocessing Package: PEP 371 The multiprocessing Package.
* PEP 3101; Advanced String Formatting: PEP 3101 Advanced String Formatting.
* PEP 3105; print As a Function: PEP 3105 print As a Function.
* PEP 3110; Exception-Handling Changes: PEP 3110 Exception-Handling Changes.
* PEP 3112; Byte Literals: PEP 3112 Byte Literals.
* PEP 3116; New I/O Library: PEP 3116 New I/O Library.
* PEP 3118; Revised Buffer Protocol: PEP 3118 Revised Buffer Protocol.
* PEP 3119; Abstract Base Classes: PEP 3119 Abstract Base Classes.
* PEP 3127; Integer Literal Support and Syntax: PEP 3127 Integer Literal Support and Syntax.
* PEP 3129; Class Decorators: PEP 3129 Class Decorators.
* PEP 3141; A Type Hierarchy for Numbers: PEP 3141 A Type Hierarchy for Numbers.
* Other Language Changes: Other Language Changes<14>.
* New and Improved Modules: New and Improved Modules<2>.
* Deprecations and Removals::
* Build and C API Changes: Build and C API Changes<9>.
* Porting to Python 2.6: Porting to Python 2 6.
* Acknowledgements: Acknowledgements<2>.

Changes to the Development Process

* New Issue Tracker; Roundup: New Issue Tracker Roundup.
* New Documentation Format; reStructuredText Using Sphinx: New Documentation Format reStructuredText Using Sphinx.

PEP 343: The “with” statement

* Writing Context Managers::
* The contextlib module::

PEP 3141: A Type Hierarchy for Numbers

* The fractions Module::

Other Language Changes

* Optimizations: Optimizations<14>.
* Interpreter Changes: Interpreter Changes<2>.

New and Improved Modules

* The ast module::
* The future_builtins module::
* The json module; JavaScript Object Notation: The json module JavaScript Object Notation.
* The plistlib module; A Property-List Parser: The plistlib module A Property-List Parser.
* ctypes Enhancements::
* Improved SSL Support::

Build and C API Changes

* Port-Specific Changes; Windows: Port-Specific Changes Windows<2>.
* Port-Specific Changes; Mac OS X: Port-Specific Changes Mac OS X<2>.
* Port-Specific Changes; IRIX: Port-Specific Changes IRIX.

What’s New in Python 2.5

* PEP 308; Conditional Expressions: PEP 308 Conditional Expressions.
* PEP 309; Partial Function Application: PEP 309 Partial Function Application.
* PEP 314; Metadata for Python Software Packages v1.1: PEP 314 Metadata for Python Software Packages v1 1.
* PEP 328; Absolute and Relative Imports: PEP 328 Absolute and Relative Imports.
* PEP 338; Executing Modules as Scripts: PEP 338 Executing Modules as Scripts.
* PEP 341; Unified try/except/finally: PEP 341 Unified try/except/finally.
* PEP 342; New Generator Features: PEP 342 New Generator Features.
* PEP 343; The “with” statement: PEP 343 The “with” statement<2>.
* PEP 352; Exceptions as New-Style Classes: PEP 352 Exceptions as New-Style Classes.
* PEP 353; Using ssize_t as the index type: PEP 353 Using ssize_t as the index type.
* PEP 357; The “__index__” method: PEP 357 The “__index__” method.
* Other Language Changes: Other Language Changes<15>.
* New, Improved, and Removed Modules: New Improved and Removed Modules.
* Build and C API Changes: Build and C API Changes<10>.
* Porting to Python 2.5: Porting to Python 2 5.
* Acknowledgements: Acknowledgements<3>.

PEP 343: The “with” statement

* Writing Context Managers: Writing Context Managers<2>.
* The contextlib module: The contextlib module<2>.

Other Language Changes

* Interactive Interpreter Changes::
* Optimizations: Optimizations<15>.

New, Improved, and Removed Modules

* The ctypes package::
* The ElementTree package::
* The hashlib package::
* The sqlite3 package::
* The wsgiref package::

Build and C API Changes

* Port-Specific Changes::

What’s New in Python 2.4

* PEP 218; Built-In Set Objects: PEP 218 Built-In Set Objects.
* PEP 237; Unifying Long Integers and Integers: PEP 237 Unifying Long Integers and Integers.
* PEP 289; Generator Expressions: PEP 289 Generator Expressions.
* PEP 292; Simpler String Substitutions: PEP 292 Simpler String Substitutions.
* PEP 318; Decorators for Functions and Methods: PEP 318 Decorators for Functions and Methods.
* PEP 322; Reverse Iteration: PEP 322 Reverse Iteration.
* PEP 324; New subprocess Module: PEP 324 New subprocess Module.
* PEP 327; Decimal Data Type: PEP 327 Decimal Data Type.
* PEP 328; Multi-line Imports: PEP 328 Multi-line Imports.
* PEP 331; Locale-Independent Float/String Conversions: PEP 331 Locale-Independent Float/String Conversions.
* Other Language Changes: Other Language Changes<16>.
* New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<3>.
* Build and C API Changes: Build and C API Changes<11>.
* Porting to Python 2.4: Porting to Python 2 4.
* Acknowledgements: Acknowledgements<4>.

PEP 327: Decimal Data Type

* Why is Decimal needed?::
* The Decimal type::
* The Context type::

Other Language Changes

* Optimizations: Optimizations<16>.

New, Improved, and Deprecated Modules

* cookielib::
* doctest: doctest<5>.

Build and C API Changes

* Port-Specific Changes: Port-Specific Changes<2>.

What’s New in Python 2.3

* PEP 218; A Standard Set Datatype: PEP 218 A Standard Set Datatype.
* PEP 255; Simple Generators: PEP 255 Simple Generators.
* PEP 263; Source Code Encodings: PEP 263 Source Code Encodings.
* PEP 273; Importing Modules from ZIP Archives: PEP 273 Importing Modules from ZIP Archives.
* PEP 277; Unicode file name support for Windows NT: PEP 277 Unicode file name support for Windows NT.
* PEP 278; Universal Newline Support: PEP 278 Universal Newline Support.
* PEP 279; enumerate(): PEP 279 enumerate.
* PEP 282; The logging Package: PEP 282 The logging Package.
* PEP 285; A Boolean Type: PEP 285 A Boolean Type.
* PEP 293; Codec Error Handling Callbacks: PEP 293 Codec Error Handling Callbacks.
* PEP 301; Package Index and Metadata for Distutils: PEP 301 Package Index and Metadata for Distutils.
* PEP 302; New Import Hooks: PEP 302 New Import Hooks.
* PEP 305; Comma-separated Files: PEP 305 Comma-separated Files.
* PEP 307; Pickle Enhancements: PEP 307 Pickle Enhancements.
* Extended Slices::
* Other Language Changes: Other Language Changes<17>.
* New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<4>.
* Pymalloc; A Specialized Object Allocator: Pymalloc A Specialized Object Allocator.
* Build and C API Changes: Build and C API Changes<12>.
* Other Changes and Fixes: Other Changes and Fixes<2>.
* Porting to Python 2.3: Porting to Python 2 3.
* Acknowledgements: Acknowledgements<5>.

Other Language Changes

* String Changes::
* Optimizations: Optimizations<17>.

New, Improved, and Deprecated Modules

* Date/Time Type::
* The optparse Module::

Build and C API Changes

* Port-Specific Changes: Port-Specific Changes<3>.

What’s New in Python 2.2

* Introduction::
* PEPs 252 and 253; Type and Class Changes: PEPs 252 and 253 Type and Class Changes.
* PEP 234; Iterators: PEP 234 Iterators.
* PEP 255; Simple Generators: PEP 255 Simple Generators<2>.
* PEP 237; Unifying Long Integers and Integers: PEP 237 Unifying Long Integers and Integers<2>.
* PEP 238; Changing the Division Operator: PEP 238 Changing the Division Operator.
* Unicode Changes::
* PEP 227; Nested Scopes: PEP 227 Nested Scopes.
* New and Improved Modules: New and Improved Modules<3>.
* Interpreter Changes and Fixes::
* Other Changes and Fixes: Other Changes and Fixes<3>.
* Acknowledgements: Acknowledgements<6>.

PEPs 252 and 253: Type and Class Changes

* Old and New Classes::
* Descriptors::
* Multiple Inheritance; The Diamond Rule: Multiple Inheritance The Diamond Rule.
* Attribute Access::
* Related Links::

What’s New in Python 2.1

* Introduction: Introduction<2>.
* PEP 227; Nested Scopes: PEP 227 Nested Scopes<2>.
* PEP 236; __future__ Directives: PEP 236 __future__ Directives.
* PEP 207; Rich Comparisons: PEP 207 Rich Comparisons.
* PEP 230; Warning Framework: PEP 230 Warning Framework.
* PEP 229; New Build System: PEP 229 New Build System.
* PEP 205; Weak References: PEP 205 Weak References.
* PEP 232; Function Attributes: PEP 232 Function Attributes.
* PEP 235; Importing Modules on Case-Insensitive Platforms: PEP 235 Importing Modules on Case-Insensitive Platforms.
* PEP 217; Interactive Display Hook: PEP 217 Interactive Display Hook.
* PEP 208; New Coercion Model: PEP 208 New Coercion Model.
* PEP 241; Metadata in Python Packages: PEP 241 Metadata in Python Packages.
* New and Improved Modules: New and Improved Modules<4>.
* Other Changes and Fixes: Other Changes and Fixes<4>.
* Acknowledgements: Acknowledgements<7>.

What’s New in Python 2.0

* Introduction: Introduction<3>.
* What About Python 1.6?: What About Python 1 6?.
* New Development Process::
* Unicode: Unicode<2>.
* List Comprehensions::
* Augmented Assignment::
* String Methods::
* Garbage Collection of Cycles::
* Other Core Changes::
* Porting to 2.0: Porting to 2 0.
* Extending/Embedding Changes::
* Distutils; Making Modules Easy to Install: Distutils Making Modules Easy to Install.
* XML Modules::
* Module changes::
* New modules: New modules<2>.
* IDLE Improvements::
* Deleted and Deprecated Modules::
* Acknowledgements: Acknowledgements<8>.

Other Core Changes

* Minor Language Changes::
* Changes to Built-in Functions::

XML Modules

* SAX2 Support::
* DOM Support::
* Relationship to PyXML::

Changelog

* Python next::
* Python 3.14.2 final: Python 3 14 2 final.
* Python 3.14.1 final: Python 3 14 1 final.
* Python 3.14.0 final: Python 3 14 0 final.
* Python 3.14.0 release candidate 3: Python 3 14 0 release candidate 3.
* Python 3.14.0 release candidate 2: Python 3 14 0 release candidate 2.
* Python 3.14.0 release candidate 1: Python 3 14 0 release candidate 1.
* Python 3.14.0 beta 4: Python 3 14 0 beta 4.
* Python 3.14.0 beta 3: Python 3 14 0 beta 3.
* Python 3.14.0 beta 2: Python 3 14 0 beta 2.
* Python 3.14.0 beta 1: Python 3 14 0 beta 1.
* Python 3.14.0 alpha 7: Python 3 14 0 alpha 7.
* Python 3.14.0 alpha 6: Python 3 14 0 alpha 6.
* Python 3.14.0 alpha 5: Python 3 14 0 alpha 5.
* Python 3.14.0 alpha 4: Python 3 14 0 alpha 4.
* Python 3.14.0 alpha 3: Python 3 14 0 alpha 3.
* Python 3.14.0 alpha 2: Python 3 14 0 alpha 2.
* Python 3.14.0 alpha 1: Python 3 14 0 alpha 1.
* Python 3.13.0 beta 1: Python 3 13 0 beta 1.
* Python 3.13.0 alpha 6: Python 3 13 0 alpha 6.
* Python 3.13.0 alpha 5: Python 3 13 0 alpha 5.
* Python 3.13.0 alpha 4: Python 3 13 0 alpha 4.
* Python 3.13.0 alpha 3: Python 3 13 0 alpha 3.
* Python 3.13.0 alpha 2: Python 3 13 0 alpha 2.
* Python 3.13.0 alpha 1: Python 3 13 0 alpha 1.
* Python 3.12.0 beta 1: Python 3 12 0 beta 1.
* Python 3.12.0 alpha 7: Python 3 12 0 alpha 7.
* Python 3.12.0 alpha 6: Python 3 12 0 alpha 6.
* Python 3.12.0 alpha 5: Python 3 12 0 alpha 5.
* Python 3.12.0 alpha 4: Python 3 12 0 alpha 4.
* Python 3.12.0 alpha 3: Python 3 12 0 alpha 3.
* Python 3.12.0 alpha 2: Python 3 12 0 alpha 2.
* Python 3.12.0 alpha 1: Python 3 12 0 alpha 1.
* Python 3.11.0 beta 1: Python 3 11 0 beta 1.
* Python 3.11.0 alpha 7: Python 3 11 0 alpha 7.
* Python 3.11.0 alpha 6: Python 3 11 0 alpha 6.
* Python 3.11.0 alpha 5: Python 3 11 0 alpha 5.
* Python 3.11.0 alpha 4: Python 3 11 0 alpha 4.
* Python 3.11.0 alpha 3: Python 3 11 0 alpha 3.
* Python 3.11.0 alpha 2: Python 3 11 0 alpha 2.
* Python 3.11.0 alpha 1: Python 3 11 0 alpha 1.
* Python 3.10.0 beta 1: Python 3 10 0 beta 1.
* Python 3.10.0 alpha 7: Python 3 10 0 alpha 7.
* Python 3.10.0 alpha 6: Python 3 10 0 alpha 6.
* Python 3.10.0 alpha 5: Python 3 10 0 alpha 5.
* Python 3.10.0 alpha 4: Python 3 10 0 alpha 4.
* Python 3.10.0 alpha 3: Python 3 10 0 alpha 3.
* Python 3.10.0 alpha 2: Python 3 10 0 alpha 2.
* Python 3.10.0 alpha 1: Python 3 10 0 alpha 1.
* Python 3.9.0 beta 1: Python 3 9 0 beta 1.
* Python 3.9.0 alpha 6: Python 3 9 0 alpha 6.
* Python 3.9.0 alpha 5: Python 3 9 0 alpha 5.
* Python 3.9.0 alpha 4: Python 3 9 0 alpha 4.
* Python 3.9.0 alpha 3: Python 3 9 0 alpha 3.
* Python 3.9.0 alpha 2: Python 3 9 0 alpha 2.
* Python 3.9.0 alpha 1: Python 3 9 0 alpha 1.
* Python 3.8.0 beta 1: Python 3 8 0 beta 1.
* Python 3.8.0 alpha 4: Python 3 8 0 alpha 4.
* Python 3.8.0 alpha 3: Python 3 8 0 alpha 3.
* Python 3.8.0 alpha 2: Python 3 8 0 alpha 2.
* Python 3.8.0 alpha 1: Python 3 8 0 alpha 1.
* Python 3.7.0 final: Python 3 7 0 final.
* Python 3.7.0 release candidate 1: Python 3 7 0 release candidate 1.
* Python 3.7.0 beta 5: Python 3 7 0 beta 5.
* Python 3.7.0 beta 4: Python 3 7 0 beta 4.
* Python 3.7.0 beta 3: Python 3 7 0 beta 3.
* Python 3.7.0 beta 2: Python 3 7 0 beta 2.
* Python 3.7.0 beta 1: Python 3 7 0 beta 1.
* Python 3.7.0 alpha 4: Python 3 7 0 alpha 4.
* Python 3.7.0 alpha 3: Python 3 7 0 alpha 3.
* Python 3.7.0 alpha 2: Python 3 7 0 alpha 2.
* Python 3.7.0 alpha 1: Python 3 7 0 alpha 1.
* Python 3.6.6 final: Python 3 6 6 final.
* Python 3.6.6 release candidate 1: Python 3 6 6 release candidate 1.
* Python 3.6.5 final: Python 3 6 5 final.
* Python 3.6.5 release candidate 1: Python 3 6 5 release candidate 1.
* Python 3.6.4 final: Python 3 6 4 final.
* Python 3.6.4 release candidate 1: Python 3 6 4 release candidate 1.
* Python 3.6.3 final: Python 3 6 3 final.
* Python 3.6.3 release candidate 1: Python 3 6 3 release candidate 1.
* Python 3.6.2 final: Python 3 6 2 final.
* Python 3.6.2 release candidate 2: Python 3 6 2 release candidate 2.
* Python 3.6.2 release candidate 1: Python 3 6 2 release candidate 1.
* Python 3.6.1 final: Python 3 6 1 final.
* Python 3.6.1 release candidate 1: Python 3 6 1 release candidate 1.
* Python 3.6.0 final: Python 3 6 0 final.
* Python 3.6.0 release candidate 2: Python 3 6 0 release candidate 2.
* Python 3.6.0 release candidate 1: Python 3 6 0 release candidate 1.
* Python 3.6.0 beta 4: Python 3 6 0 beta 4.
* Python 3.6.0 beta 3: Python 3 6 0 beta 3.
* Python 3.6.0 beta 2: Python 3 6 0 beta 2.
* Python 3.6.0 beta 1: Python 3 6 0 beta 1.
* Python 3.6.0 alpha 4: Python 3 6 0 alpha 4.
* Python 3.6.0 alpha 3: Python 3 6 0 alpha 3.
* Python 3.6.0 alpha 2: Python 3 6 0 alpha 2.
* Python 3.6.0 alpha 1: Python 3 6 0 alpha 1.
* Python 3.5.5 final: Python 3 5 5 final.
* Python 3.5.5 release candidate 1: Python 3 5 5 release candidate 1.
* Python 3.5.4 final: Python 3 5 4 final.
* Python 3.5.4 release candidate 1: Python 3 5 4 release candidate 1.
* Python 3.5.3 final: Python 3 5 3 final.
* Python 3.5.3 release candidate 1: Python 3 5 3 release candidate 1.
* Python 3.5.2 final: Python 3 5 2 final.
* Python 3.5.2 release candidate 1: Python 3 5 2 release candidate 1.
* Python 3.5.1 final: Python 3 5 1 final.
* Python 3.5.1 release candidate 1: Python 3 5 1 release candidate 1.
* Python 3.5.0 final: Python 3 5 0 final.
* Python 3.5.0 release candidate 4: Python 3 5 0 release candidate 4.
* Python 3.5.0 release candidate 3: Python 3 5 0 release candidate 3.
* Python 3.5.0 release candidate 2: Python 3 5 0 release candidate 2.
* Python 3.5.0 release candidate 1: Python 3 5 0 release candidate 1.
* Python 3.5.0 beta 4: Python 3 5 0 beta 4.
* Python 3.5.0 beta 3: Python 3 5 0 beta 3.
* Python 3.5.0 beta 2: Python 3 5 0 beta 2.
* Python 3.5.0 beta 1: Python 3 5 0 beta 1.
* Python 3.5.0 alpha 4: Python 3 5 0 alpha 4.
* Python 3.5.0 alpha 3: Python 3 5 0 alpha 3.
* Python 3.5.0 alpha 2: Python 3 5 0 alpha 2.
* Python 3.5.0 alpha 1: Python 3 5 0 alpha 1.

Python next

* Windows::
* Tools/Demos::
* Tests::
* Security::
* Library::
* IDLE: IDLE<3>.
* Documentation: Documentation<2>.
* Core and Builtins::
* C API::
* Build::

Python 3.14.2 final

* Security: Security<2>.
* Library: Library<2>.
* Core and Builtins: Core and Builtins<2>.
* Library: Library<3>.

Python 3.14.1 final

* Windows: Windows<2>.
* Tools/Demos: Tools/Demos<2>.
* Tests: Tests<2>.
* Security: Security<3>.
* Library: Library<4>.
* IDLE: IDLE<4>.
* Documentation: Documentation<3>.
* Core and Builtins: Core and Builtins<3>.
* Library: Library<5>.
* Core and Builtins: Core and Builtins<4>.
* Library: Library<6>.
* Core and Builtins: Core and Builtins<5>.
* Library: Library<7>.
* Core and Builtins: Core and Builtins<6>.
* Library: Library<8>.
* Core and Builtins: Core and Builtins<7>.
* Library: Library<9>.
* Core and Builtins: Core and Builtins<8>.
* Library: Library<10>.
* Core and Builtins: Core and Builtins<9>.
* C API: C API<2>.
* Build: Build<2>.

Python 3.14.0 final

* macOS::
* Windows: Windows<3>.
* Tools/Demos: Tools/Demos<3>.
* Security: Security<4>.
* Library: Library<11>.

Python 3.14.0 release candidate 3

* Windows: Windows<4>.
* Tools/Demos: Tools/Demos<4>.
* Security: Security<5>.
* Library: Library<12>.
* Core and Builtins: Core and Builtins<10>.

Python 3.14.0 release candidate 2

* macOS: macOS<2>.
* Windows: Windows<5>.
* Library: Library<13>.
* Documentation: Documentation<4>.
* Core and Builtins: Core and Builtins<11>.
* C API: C API<3>.
* Build: Build<3>.

Python 3.14.0 release candidate 1

* Tools/Demos: Tools/Demos<5>.
* Security: Security<6>.
* Library: Library<14>.
* Core and Builtins: Core and Builtins<12>.
* Library: Library<15>.
* Core and Builtins: Core and Builtins<13>.
* Library: Library<16>.
* Core and Builtins: Core and Builtins<14>.
* C API: C API<4>.
* Build: Build<4>.

Python 3.14.0 beta 4

* Tools/Demos: Tools/Demos<6>.
* Tests: Tests<3>.
* Security: Security<7>.
* Library: Library<17>.
* Documentation: Documentation<5>.
* Core and Builtins: Core and Builtins<15>.
* C API: C API<5>.
* Build: Build<5>.

Python 3.14.0 beta 3

* Windows: Windows<6>.
* Tests: Tests<4>.
* Security: Security<8>.
* Library: Library<18>.
* Documentation: Documentation<6>.
* Core and Builtins: Core and Builtins<16>.
* Library: Library<19>.
* Core and Builtins: Core and Builtins<17>.
* Library: Library<20>.
* Core and Builtins: Core and Builtins<18>.
* Library: Library<21>.
* Core and Builtins: Core and Builtins<19>.
* C API: C API<6>.
* Build: Build<6>.

Python 3.14.0 beta 2

* Windows: Windows<7>.
* Tools/Demos: Tools/Demos<7>.
* Tests: Tests<5>.
* Security: Security<9>.
* Library: Library<22>.
* Core and Builtins: Core and Builtins<20>.
* C API: C API<7>.
* Build: Build<7>.

Python 3.14.0 beta 1

* Windows: Windows<8>.
* Tools/Demos: Tools/Demos<8>.
* Tests: Tests<6>.
* Security: Security<10>.
* Library: Library<23>.
* IDLE: IDLE<5>.
* Documentation: Documentation<7>.
* Core and Builtins: Core and Builtins<21>.
* Library: Library<24>.
* Core and Builtins: Core and Builtins<22>.
* Library: Library<25>.
* Core and Builtins: Core and Builtins<23>.
* Library: Library<26>.
* C API: C API<8>.
* Build: Build<8>.

Python 3.14.0 alpha 7

* macOS: macOS<3>.
* Windows: Windows<9>.
* Tools/Demos: Tools/Demos<9>.
* Tests: Tests<7>.
* Security: Security<11>.
* Library: Library<27>.
* Documentation: Documentation<8>.
* Core and Builtins: Core and Builtins<24>.
* Library: Library<28>.
* Core and Builtins: Core and Builtins<25>.
* C API: C API<9>.
* Build: Build<9>.

Python 3.14.0 alpha 6

* macOS: macOS<4>.
* Windows: Windows<10>.
* Tools/Demos: Tools/Demos<10>.
* Tests: Tests<8>.
* Security: Security<12>.
* Library: Library<29>.
* Documentation: Documentation<9>.
* Core and Builtins: Core and Builtins<26>.
* Library: Library<30>.
* Core and Builtins: Core and Builtins<27>.
* Library: Library<31>.
* Core and Builtins: Core and Builtins<28>.
* C API: C API<10>.
* Build: Build<10>.

Python 3.14.0 alpha 5

* macOS: macOS<5>.
* Tools/Demos: Tools/Demos<11>.
* Tests: Tests<9>.
* Security: Security<13>.
* Library: Library<32>.
* IDLE: IDLE<6>.
* Documentation: Documentation<10>.
* Core and Builtins: Core and Builtins<29>.
* Library: Library<33>.
* Core and Builtins: Core and Builtins<30>.
* Library: Library<34>.
* Core and Builtins: Core and Builtins<31>.
* Library: Library<35>.
* C API: C API<11>.
* Build: Build<11>.

Python 3.14.0 alpha 4

* macOS: macOS<6>.
* Tools/Demos: Tools/Demos<12>.
* Tests: Tests<10>.
* Library: Library<36>.
* Core and Builtins: Core and Builtins<32>.
* Library: Library<37>.
* Core and Builtins: Core and Builtins<33>.
* Library: Library<38>.
* Core and Builtins: Core and Builtins<34>.
* C API: C API<12>.
* Build: Build<12>.

Python 3.14.0 alpha 3

* Windows: Windows<11>.
* Tools/Demos: Tools/Demos<13>.
* Tests: Tests<11>.
* Security: Security<14>.
* Library: Library<39>.
* Documentation: Documentation<11>.
* Core and Builtins: Core and Builtins<35>.
* Library: Library<40>.
* Core and Builtins: Core and Builtins<36>.
* C API: C API<13>.
* Build: Build<13>.

Python 3.14.0 alpha 2

* Windows: Windows<12>.
* Tools/Demos: Tools/Demos<14>.
* Tests: Tests<12>.
* Security: Security<15>.
* Library: Library<41>.
* Documentation: Documentation<12>.
* Core and Builtins: Core and Builtins<37>.
* Library: Library<42>.
* Core and Builtins: Core and Builtins<38>.
* Library: Library<43>.
* Core and Builtins: Core and Builtins<39>.
* Library: Library<44>.
* C API: C API<14>.
* Build: Build<14>.

Python 3.14.0 alpha 1

* macOS: macOS<7>.
* Windows: Windows<13>.
* Tools/Demos: Tools/Demos<15>.
* Tests: Tests<13>.
* Security: Security<16>.
* Library: Library<45>.
* IDLE: IDLE<7>.
* Documentation: Documentation<13>.
* Core and Builtins: Core and Builtins<40>.
* Library: Library<46>.
* Core and Builtins: Core and Builtins<41>.
* Library: Library<47>.
* Core and Builtins: Core and Builtins<42>.
* Library: Library<48>.
* Core and Builtins: Core and Builtins<43>.
* Library: Library<49>.
* Core and Builtins: Core and Builtins<44>.
* Library: Library<50>.
* Core and Builtins: Core and Builtins<45>.
* Library: Library<51>.
* Core and Builtins: Core and Builtins<46>.
* Library: Library<52>.
* Core and Builtins: Core and Builtins<47>.
* C API: C API<15>.
* Build: Build<15>.

Python 3.13.0 beta 1

* Security: Security<17>.
* Core and Builtins: Core and Builtins<48>.
* Library: Library<53>.
* Core and Builtins: Core and Builtins<49>.
* Library: Library<54>.
* Documentation: Documentation<14>.
* Build: Build<16>.
* Windows: Windows<14>.
* macOS: macOS<8>.
* IDLE: IDLE<8>.
* C API: C API<16>.

Python 3.13.0 alpha 6

* Core and Builtins: Core and Builtins<50>.
* Library: Library<55>.
* Core and Builtins: Core and Builtins<51>.
* Library: Library<56>.
* Documentation: Documentation<15>.
* Tests: Tests<14>.
* Build: Build<17>.
* Windows: Windows<15>.
* C API: C API<17>.

Python 3.13.0 alpha 5

* Security: Security<18>.
* Core and Builtins: Core and Builtins<52>.
* Library: Library<57>.
* Core and Builtins: Core and Builtins<53>.
* Library: Library<58>.
* Core and Builtins: Core and Builtins<54>.
* Library: Library<59>.
* Documentation: Documentation<16>.
* Tests: Tests<15>.
* Build: Build<18>.
* Windows: Windows<16>.
* macOS: macOS<9>.
* IDLE: IDLE<9>.
* Tools/Demos: Tools/Demos<16>.
* C API: C API<18>.

Python 3.13.0 alpha 4

* Security: Security<19>.
* Core and Builtins: Core and Builtins<55>.
* Library: Library<60>.
* Documentation: Documentation<17>.
* Tests: Tests<16>.
* Build: Build<19>.
* Windows: Windows<17>.
* macOS: macOS<10>.
* IDLE: IDLE<10>.
* Tools/Demos: Tools/Demos<17>.
* C API: C API<19>.

Python 3.13.0 alpha 3

* Security: Security<20>.
* Core and Builtins: Core and Builtins<56>.
* Library: Library<61>.
* Documentation: Documentation<18>.
* Tests: Tests<17>.
* Build: Build<20>.
* Windows: Windows<18>.
* macOS: macOS<11>.
* IDLE: IDLE<11>.
* C API: C API<20>.

Python 3.13.0 alpha 2

* Core and Builtins: Core and Builtins<57>.
* Library: Library<62>.
* Tests: Tests<18>.
* Build: Build<21>.
* Windows: Windows<19>.
* macOS: macOS<12>.
* IDLE: IDLE<12>.
* Tools/Demos: Tools/Demos<18>.
* C API: C API<21>.

Python 3.13.0 alpha 1

* Security: Security<21>.
* Core and Builtins: Core and Builtins<58>.
* Library: Library<63>.
* Documentation: Documentation<19>.
* Tests: Tests<19>.
* Build: Build<22>.
* Windows: Windows<20>.
* macOS: macOS<13>.
* IDLE: IDLE<13>.
* Tools/Demos: Tools/Demos<19>.
* C API: C API<22>.

Python 3.12.0 beta 1

* Security: Security<22>.
* Library: Library<64>.
* Core and Builtins: Core and Builtins<59>.
* Library: Library<65>.
* Core and Builtins: Core and Builtins<60>.
* Library: Library<66>.
* Documentation: Documentation<20>.
* Tests: Tests<20>.
* Build: Build<23>.
* Windows: Windows<21>.
* macOS: macOS<14>.
* IDLE: IDLE<14>.
* Tools/Demos: Tools/Demos<20>.
* C API: C API<23>.

Python 3.12.0 alpha 7

* Core and Builtins: Core and Builtins<61>.
* Library: Library<67>.
* Core and Builtins: Core and Builtins<62>.
* Build: Build<24>.
* Core and Builtins: Core and Builtins<63>.
* Library: Library<68>.
* Documentation: Documentation<21>.
* Tests: Tests<21>.
* Build: Build<25>.
* Windows: Windows<22>.
* Tools/Demos: Tools/Demos<21>.
* C API: C API<24>.

Python 3.12.0 alpha 6

* Security: Security<23>.
* Core and Builtins: Core and Builtins<64>.
* Library: Library<69>.
* Documentation: Documentation<22>.
* Tests: Tests<22>.
* Build: Build<26>.
* Windows: Windows<23>.
* macOS: macOS<15>.
* C API: C API<25>.

Python 3.12.0 alpha 5

* Security: Security<24>.
* Core and Builtins: Core and Builtins<65>.
* Library: Library<70>.
* Documentation: Documentation<23>.
* Tests: Tests<23>.
* Build: Build<27>.
* Windows: Windows<24>.

Python 3.12.0 alpha 4

* Core and Builtins: Core and Builtins<66>.
* Library: Library<71>.
* Core and Builtins: Core and Builtins<67>.
* Library: Library<72>.
* Core and Builtins: Core and Builtins<68>.
* Library: Library<73>.
* Documentation: Documentation<24>.
* Tests: Tests<24>.
* Build: Build<28>.
* Windows: Windows<25>.
* macOS: macOS<16>.
* Tools/Demos: Tools/Demos<22>.
* C API: C API<26>.

Python 3.12.0 alpha 3

* Security: Security<25>.
* Core and Builtins: Core and Builtins<69>.
* Library: Library<74>.
* Core and Builtins: Core and Builtins<70>.
* Library: Library<75>.
* Documentation: Documentation<25>.
* Tests: Tests<25>.
* Build: Build<29>.
* Windows: Windows<26>.
* macOS: macOS<17>.
* Tools/Demos: Tools/Demos<23>.
* C API: C API<27>.

Python 3.12.0 alpha 2

* Security: Security<26>.
* Core and Builtins: Core and Builtins<71>.
* Build: Build<30>.
* Core and Builtins: Core and Builtins<72>.
* Library: Library<76>.
* Documentation: Documentation<26>.
* Tests: Tests<26>.
* Build: Build<31>.
* Windows: Windows<27>.
* macOS: macOS<18>.
* C API: C API<28>.

Python 3.12.0 alpha 1

* Security: Security<27>.
* Core and Builtins: Core and Builtins<73>.
* Library: Library<77>.
* Core and Builtins: Core and Builtins<74>.
* Library: Library<78>.
* Core and Builtins: Core and Builtins<75>.
* Library: Library<79>.
* Core and Builtins: Core and Builtins<76>.
* Library: Library<80>.
* Core and Builtins: Core and Builtins<77>.
* Library: Library<81>.
* Core and Builtins: Core and Builtins<78>.
* Library: Library<82>.
* Core and Builtins: Core and Builtins<79>.
* Library: Library<83>.
* Core and Builtins: Core and Builtins<80>.
* Library: Library<84>.
* Core and Builtins: Core and Builtins<81>.
* Library: Library<85>.
* Core and Builtins: Core and Builtins<82>.
* Library: Library<86>.
* Documentation: Documentation<27>.
* Tests: Tests<27>.
* Build: Build<32>.
* Windows: Windows<28>.
* macOS: macOS<19>.
* IDLE: IDLE<15>.
* Tools/Demos: Tools/Demos<24>.
* C API: C API<29>.

Python 3.11.0 beta 1

* Security: Security<28>.
* Core and Builtins: Core and Builtins<83>.
* Library: Library<87>.
* Core and Builtins: Core and Builtins<84>.
* Build: Build<33>.
* Core and Builtins: Core and Builtins<85>.
* Library: Library<88>.
* Documentation: Documentation<28>.
* Tests: Tests<28>.
* Build: Build<34>.
* Windows: Windows<29>.
* macOS: macOS<20>.
* Tools/Demos: Tools/Demos<25>.
* C API: C API<30>.

Python 3.11.0 alpha 7

* Core and Builtins: Core and Builtins<86>.
* Library: Library<89>.
* Core and Builtins: Core and Builtins<87>.
* Library: Library<90>.
* Core and Builtins: Core and Builtins<88>.
* Library: Library<91>.
* Documentation: Documentation<29>.
* Tests: Tests<29>.
* Build: Build<35>.
* Windows: Windows<30>.
* macOS: macOS<21>.
* Tools/Demos: Tools/Demos<26>.
* C API: C API<31>.

Python 3.11.0 alpha 6

* Core and Builtins: Core and Builtins<89>.
* Library: Library<92>.
* Core and Builtins: Core and Builtins<90>.
* Library: Library<93>.
* Core and Builtins: Core and Builtins<91>.
* Library: Library<94>.
* Core and Builtins: Core and Builtins<92>.
* Library: Library<95>.
* Documentation: Documentation<30>.
* Tests: Tests<30>.
* Build: Build<36>.
* Windows: Windows<31>.
* IDLE: IDLE<16>.
* C API: C API<32>.

Python 3.11.0 alpha 5

* Core and Builtins: Core and Builtins<93>.
* Library: Library<96>.
* Core and Builtins: Core and Builtins<94>.
* Library: Library<97>.
* Build: Build<37>.
* Core and Builtins: Core and Builtins<95>.
* Library: Library<98>.
* Documentation: Documentation<31>.
* Tests: Tests<31>.
* Build: Build<38>.
* Windows: Windows<32>.
* macOS: macOS<22>.
* IDLE: IDLE<17>.
* C API: C API<33>.

Python 3.11.0 alpha 4

* Core and Builtins: Core and Builtins<96>.
* Library: Library<99>.
* Core and Builtins: Core and Builtins<97>.
* Library: Library<100>.
* Core and Builtins: Core and Builtins<98>.
* Library: Library<101>.
* Core and Builtins: Core and Builtins<99>.
* Library: Library<102>.
* Documentation: Documentation<32>.
* Tests: Tests<32>.
* Build: Build<39>.
* Windows: Windows<33>.
* macOS: macOS<23>.
* C API: C API<34>.

Python 3.11.0 alpha 3

* Core and Builtins: Core and Builtins<100>.
* Library: Library<103>.
* Core and Builtins: Core and Builtins<101>.
* Library: Library<104>.
* Documentation: Documentation<33>.
* Tests: Tests<33>.
* Build: Build<40>.
* Windows: Windows<34>.
* macOS: macOS<24>.
* C API: C API<35>.

Python 3.11.0 alpha 2

* Core and Builtins: Core and Builtins<102>.
* Library: Library<105>.
* Documentation: Documentation<34>.
* Tests: Tests<34>.
* Build: Build<41>.
* Windows: Windows<35>.
* macOS: macOS<25>.
* IDLE: IDLE<18>.
* C API: C API<36>.

Python 3.11.0 alpha 1

* Security: Security<29>.
* Core and Builtins: Core and Builtins<103>.
* Library: Library<106>.
* Core and Builtins: Core and Builtins<104>.
* Library: Library<107>.
* Core and Builtins: Core and Builtins<105>.
* Library: Library<108>.
* Core and Builtins: Core and Builtins<106>.
* Library: Library<109>.
* Core and Builtins: Core and Builtins<107>.
* Library: Library<110>.
* Core and Builtins: Core and Builtins<108>.
* Library: Library<111>.
* Core and Builtins: Core and Builtins<109>.
* Library: Library<112>.
* Core and Builtins: Core and Builtins<110>.
* Library: Library<113>.
* Core and Builtins: Core and Builtins<111>.
* Library: Library<114>.
* Core and Builtins: Core and Builtins<112>.
* Library: Library<115>.
* Documentation: Documentation<35>.
* Tests: Tests<35>.
* Build: Build<42>.
* Windows: Windows<36>.
* macOS: macOS<26>.
* IDLE: IDLE<19>.
* Tools/Demos: Tools/Demos<27>.
* C API: C API<37>.

Python 3.10.0 beta 1

* Security: Security<30>.
* Core and Builtins: Core and Builtins<113>.
* Library: Library<116>.
* Core and Builtins: Core and Builtins<114>.
* Library: Library<117>.
* Core and Builtins: Core and Builtins<115>.
* Library: Library<118>.
* Documentation: Documentation<36>.
* Tests: Tests<36>.
* Build: Build<43>.
* Windows: Windows<37>.
* macOS: macOS<27>.
* IDLE: IDLE<20>.
* C API: C API<38>.

Python 3.10.0 alpha 7

* Security: Security<31>.
* Core and Builtins: Core and Builtins<116>.
* Library: Library<119>.
* Core and Builtins: Core and Builtins<117>.
* Library: Library<120>.
* Documentation: Documentation<37>.
* Tests: Tests<37>.
* Build: Build<44>.
* Windows: Windows<38>.
* IDLE: IDLE<21>.
* C API: C API<39>.

Python 3.10.0 alpha 6

* Security: Security<32>.
* Core and Builtins: Core and Builtins<118>.
* Library: Library<121>.
* Core and Builtins: Core and Builtins<119>.
* Library: Library<122>.
* Core and Builtins: Core and Builtins<120>.
* Library: Library<123>.
* Documentation: Documentation<38>.
* Tests: Tests<38>.
* Build: Build<45>.
* Windows: Windows<39>.
* macOS: macOS<28>.
* IDLE: IDLE<22>.
* C API: C API<40>.

Python 3.10.0 alpha 5

* Security: Security<33>.
* Core and Builtins: Core and Builtins<121>.
* Library: Library<124>.
* Core and Builtins: Core and Builtins<122>.
* Library: Library<125>.
* Documentation: Documentation<39>.
* Tests: Tests<39>.
* Build: Build<46>.
* Windows: Windows<40>.
* macOS: macOS<29>.
* IDLE: IDLE<23>.
* C API: C API<41>.

Python 3.10.0 alpha 4

* Core and Builtins: Core and Builtins<123>.
* Library: Library<126>.
* Core and Builtins: Core and Builtins<124>.
* Library: Library<127>.
* Core and Builtins: Core and Builtins<125>.
* Library: Library<128>.
* Documentation: Documentation<40>.
* Tests: Tests<40>.
* Build: Build<47>.
* macOS: macOS<30>.
* Tools/Demos: Tools/Demos<28>.
* C API: C API<42>.

Python 3.10.0 alpha 3

* Security: Security<34>.
* Core and Builtins: Core and Builtins<126>.
* Library: Library<129>.
* Core and Builtins: Core and Builtins<127>.
* Library: Library<130>.
* Core and Builtins: Core and Builtins<128>.
* Library: Library<131>.
* Core and Builtins: Core and Builtins<129>.
* Library: Library<132>.
* Documentation: Documentation<41>.
* Tests: Tests<41>.
* Build: Build<48>.
* Windows: Windows<41>.
* macOS: macOS<31>.
* IDLE: IDLE<24>.
* Tools/Demos: Tools/Demos<29>.
* C API: C API<43>.

Python 3.10.0 alpha 2

* Security: Security<35>.
* Core and Builtins: Core and Builtins<130>.
* Library: Library<133>.
* Core and Builtins: Core and Builtins<131>.
* Library: Library<134>.
* Documentation: Documentation<42>.
* Tests: Tests<42>.
* Build: Build<49>.
* Windows: Windows<42>.
* macOS: macOS<32>.
* IDLE: IDLE<25>.
* C API: C API<44>.

Python 3.10.0 alpha 1

* Security: Security<36>.
* Core and Builtins: Core and Builtins<132>.
* Library: Library<135>.
* Core and Builtins: Core and Builtins<133>.
* Library: Library<136>.
* Core and Builtins: Core and Builtins<134>.
* Library: Library<137>.
* Core and Builtins: Core and Builtins<135>.
* Library: Library<138>.
* Core and Builtins: Core and Builtins<136>.
* Library: Library<139>.
* Core and Builtins: Core and Builtins<137>.
* Library: Library<140>.
* Core and Builtins: Core and Builtins<138>.
* Library: Library<141>.
* Core and Builtins: Core and Builtins<139>.
* Library: Library<142>.
* Core and Builtins: Core and Builtins<140>.
* Library: Library<143>.
* Core and Builtins: Core and Builtins<141>.
* Library: Library<144>.
* Core and Builtins: Core and Builtins<142>.
* Library: Library<145>.
* Core and Builtins: Core and Builtins<143>.
* Library: Library<146>.
* Core and Builtins: Core and Builtins<144>.
* Library: Library<147>.
* Core and Builtins: Core and Builtins<145>.
* Library: Library<148>.
* Core and Builtins: Core and Builtins<146>.
* Library: Library<149>.
* Documentation: Documentation<43>.
* Tests: Tests<43>.
* Build: Build<50>.
* Windows: Windows<43>.
* macOS: macOS<33>.
* IDLE: IDLE<26>.
* C API: C API<45>.

Python 3.9.0 beta 1

* Security: Security<37>.
* Core and Builtins: Core and Builtins<147>.
* Library: Library<150>.
* Documentation: Documentation<44>.
* Tests: Tests<44>.
* Build: Build<51>.
* Windows: Windows<44>.
* macOS: macOS<34>.
* Tools/Demos: Tools/Demos<30>.
* C API: C API<46>.

Python 3.9.0 alpha 6

* Security: Security<38>.
* Core and Builtins: Core and Builtins<148>.
* Library: Library<151>.
* Documentation: Documentation<45>.
* Tests: Tests<45>.
* Build: Build<52>.
* Windows: Windows<45>.
* macOS: macOS<35>.
* IDLE: IDLE<27>.
* Tools/Demos: Tools/Demos<31>.
* C API: C API<47>.

Python 3.9.0 alpha 5

* Security: Security<39>.
* Core and Builtins: Core and Builtins<149>.
* Library: Library<152>.
* Documentation: Documentation<46>.
* Tests: Tests<46>.
* Build: Build<53>.
* Windows: Windows<46>.
* macOS: macOS<36>.
* IDLE: IDLE<28>.
* Tools/Demos: Tools/Demos<32>.
* C API: C API<48>.

Python 3.9.0 alpha 4

* Security: Security<40>.
* Core and Builtins: Core and Builtins<150>.
* Library: Library<153>.
* Documentation: Documentation<47>.
* Tests: Tests<47>.
* Build: Build<54>.
* Windows: Windows<47>.
* IDLE: IDLE<29>.
* C API: C API<49>.

Python 3.9.0 alpha 3

* Core and Builtins: Core and Builtins<151>.
* Library: Library<154>.
* Documentation: Documentation<48>.
* Build: Build<55>.
* IDLE: IDLE<30>.
* C API: C API<50>.

Python 3.9.0 alpha 2

* Security: Security<41>.
* Core and Builtins: Core and Builtins<152>.
* Library: Library<155>.
* Documentation: Documentation<49>.
* Tests: Tests<48>.
* Build: Build<56>.
* Windows: Windows<48>.
* macOS: macOS<37>.
* IDLE: IDLE<31>.
* C API: C API<51>.

Python 3.9.0 alpha 1

* Security: Security<42>.
* Core and Builtins: Core and Builtins<153>.
* Library: Library<156>.
* Documentation: Documentation<50>.
* Tests: Tests<49>.
* Build: Build<57>.
* Windows: Windows<49>.
* macOS: macOS<38>.
* IDLE: IDLE<32>.
* Tools/Demos: Tools/Demos<33>.
* C API: C API<52>.

Python 3.8.0 beta 1

* Security: Security<43>.
* Core and Builtins: Core and Builtins<154>.
* Library: Library<157>.
* Documentation: Documentation<51>.
* Tests: Tests<50>.
* Build: Build<58>.
* Windows: Windows<50>.
* macOS: macOS<39>.
* IDLE: IDLE<33>.
* Tools/Demos: Tools/Demos<34>.
* C API: C API<53>.

Python 3.8.0 alpha 4

* Security: Security<44>.
* Core and Builtins: Core and Builtins<155>.
* Library: Library<158>.
* Documentation: Documentation<52>.
* Tests: Tests<51>.
* Build: Build<59>.
* Windows: Windows<51>.
* macOS: macOS<40>.
* IDLE: IDLE<34>.
* Tools/Demos: Tools/Demos<35>.
* C API: C API<54>.

Python 3.8.0 alpha 3

* Security: Security<45>.
* Core and Builtins: Core and Builtins<156>.
* Library: Library<159>.
* Documentation: Documentation<53>.
* Tests: Tests<52>.
* Build: Build<60>.
* Windows: Windows<52>.
* IDLE: IDLE<35>.
* Tools/Demos: Tools/Demos<36>.
* C API: C API<55>.

Python 3.8.0 alpha 2

* Core and Builtins: Core and Builtins<157>.
* Library: Library<160>.
* Documentation: Documentation<54>.
* Tests: Tests<53>.
* Windows: Windows<53>.
* IDLE: IDLE<36>.

Python 3.8.0 alpha 1

* Security: Security<46>.
* Core and Builtins: Core and Builtins<158>.
* Library: Library<161>.
* Documentation: Documentation<55>.
* Tests: Tests<54>.
* Build: Build<61>.
* Windows: Windows<54>.
* macOS: macOS<41>.
* IDLE: IDLE<37>.
* Tools/Demos: Tools/Demos<37>.
* C API: C API<56>.

Python 3.7.0 final

* Library: Library<162>.
* C API: C API<57>.

Python 3.7.0 release candidate 1

* Core and Builtins: Core and Builtins<159>.
* Library: Library<163>.
* Documentation: Documentation<56>.
* Build: Build<62>.
* Windows: Windows<55>.
* IDLE: IDLE<38>.

Python 3.7.0 beta 5

* Core and Builtins: Core and Builtins<160>.
* Library: Library<164>.
* Documentation: Documentation<57>.
* Tests: Tests<55>.
* Build: Build<63>.
* macOS: macOS<42>.
* IDLE: IDLE<39>.

Python 3.7.0 beta 4

* Core and Builtins: Core and Builtins<161>.
* Library: Library<165>.
* Documentation: Documentation<58>.
* Tests: Tests<56>.
* Build: Build<64>.
* Windows: Windows<56>.
* macOS: macOS<43>.
* IDLE: IDLE<40>.
* Tools/Demos: Tools/Demos<38>.

Python 3.7.0 beta 3

* Security: Security<47>.
* Core and Builtins: Core and Builtins<162>.
* Library: Library<166>.
* Documentation: Documentation<59>.
* Tests: Tests<57>.
* Build: Build<65>.
* Windows: Windows<57>.
* macOS: macOS<44>.
* IDLE: IDLE<41>.
* Tools/Demos: Tools/Demos<39>.
* C API: C API<58>.

Python 3.7.0 beta 2

* Security: Security<48>.
* Core and Builtins: Core and Builtins<163>.
* Library: Library<167>.
* Documentation: Documentation<60>.
* Tests: Tests<58>.
* Build: Build<66>.
* Windows: Windows<58>.
* macOS: macOS<45>.
* IDLE: IDLE<42>.
* Tools/Demos: Tools/Demos<40>.

Python 3.7.0 beta 1

* Core and Builtins: Core and Builtins<164>.
* Library: Library<168>.
* Documentation: Documentation<61>.
* Tests: Tests<59>.
* Build: Build<67>.
* Windows: Windows<59>.
* macOS: macOS<46>.
* C API: C API<59>.

Python 3.7.0 alpha 4

* Core and Builtins: Core and Builtins<165>.
* Library: Library<169>.
* Documentation: Documentation<62>.
* Tests: Tests<60>.
* Windows: Windows<60>.
* Tools/Demos: Tools/Demos<41>.
* C API: C API<60>.

Python 3.7.0 alpha 3

* Core and Builtins: Core and Builtins<166>.
* Library: Library<170>.
* Documentation: Documentation<63>.
* Tests: Tests<61>.
* Build: Build<68>.
* Windows: Windows<61>.
* macOS: macOS<47>.
* IDLE: IDLE<43>.
* Tools/Demos: Tools/Demos<42>.
* C API: C API<61>.

Python 3.7.0 alpha 2

* Core and Builtins: Core and Builtins<167>.
* Library: Library<171>.
* Documentation: Documentation<64>.
* Build: Build<69>.
* IDLE: IDLE<44>.
* C API: C API<62>.

Python 3.7.0 alpha 1

* Security: Security<49>.
* Core and Builtins: Core and Builtins<168>.
* Library: Library<172>.
* Documentation: Documentation<65>.
* Tests: Tests<62>.
* Build: Build<70>.
* Windows: Windows<62>.
* IDLE: IDLE<45>.
* Tools/Demos: Tools/Demos<43>.
* C API: C API<63>.

Python 3.6.6 release candidate 1

* Core and Builtins: Core and Builtins<169>.
* Library: Library<173>.
* Documentation: Documentation<66>.
* Tests: Tests<63>.
* Build: Build<71>.
* Windows: Windows<63>.
* macOS: macOS<48>.
* IDLE: IDLE<46>.
* Tools/Demos: Tools/Demos<44>.
* C API: C API<64>.

Python 3.6.5 final

* Tests: Tests<64>.
* Build: Build<72>.

Python 3.6.5 release candidate 1

* Security: Security<50>.
* Core and Builtins: Core and Builtins<170>.
* Library: Library<174>.
* Documentation: Documentation<67>.
* Tests: Tests<65>.
* Build: Build<73>.
* Windows: Windows<64>.
* macOS: macOS<49>.
* IDLE: IDLE<47>.
* Tools/Demos: Tools/Demos<45>.
* C API: C API<65>.

Python 3.6.4 release candidate 1

* Core and Builtins: Core and Builtins<171>.
* Library: Library<175>.
* Documentation: Documentation<68>.
* Tests: Tests<66>.
* Build: Build<74>.
* Windows: Windows<65>.
* macOS: macOS<50>.
* IDLE: IDLE<48>.
* Tools/Demos: Tools/Demos<46>.
* C API: C API<66>.

Python 3.6.3 final

* Library: Library<176>.
* Build: Build<75>.

Python 3.6.3 release candidate 1

* Security: Security<51>.
* Core and Builtins: Core and Builtins<172>.
* Library: Library<177>.
* Documentation: Documentation<69>.
* Tests: Tests<67>.
* Build: Build<76>.
* Windows: Windows<66>.
* IDLE: IDLE<49>.
* Tools/Demos: Tools/Demos<47>.

Python 3.6.2 release candidate 2

* Security: Security<52>.

Python 3.6.2 release candidate 1

* Security: Security<53>.
* Core and Builtins: Core and Builtins<173>.
* Library: Library<178>.
* IDLE: IDLE<50>.
* C API: C API<67>.
* Build: Build<77>.
* Documentation: Documentation<70>.
* Tools/Demos: Tools/Demos<48>.
* Tests: Tests<68>.
* Windows: Windows<67>.

Python 3.6.1 final

* Core and Builtins: Core and Builtins<174>.
* Build: Build<78>.

Python 3.6.1 release candidate 1

* Core and Builtins: Core and Builtins<175>.
* Library: Library<179>.
* IDLE: IDLE<51>.
* Windows: Windows<68>.
* C API: C API<68>.
* Documentation: Documentation<71>.
* Tests: Tests<69>.
* Build: Build<79>.

Python 3.6.0 release candidate 2

* Core and Builtins: Core and Builtins<176>.
* Tools/Demos: Tools/Demos<49>.
* Windows: Windows<69>.
* Build: Build<80>.

Python 3.6.0 release candidate 1

* Core and Builtins: Core and Builtins<177>.
* Library: Library<180>.
* C API: C API<69>.
* Documentation: Documentation<72>.
* Tools/Demos: Tools/Demos<50>.

Python 3.6.0 beta 4

* Core and Builtins: Core and Builtins<178>.
* Library: Library<181>.
* Documentation: Documentation<73>.
* Tests: Tests<70>.
* Build: Build<81>.

Python 3.6.0 beta 3

* Core and Builtins: Core and Builtins<179>.
* Library: Library<182>.
* Windows: Windows<70>.
* Build: Build<82>.
* Tests: Tests<71>.

Python 3.6.0 beta 2

* Core and Builtins: Core and Builtins<180>.
* Library: Library<183>.
* Windows: Windows<71>.
* C API: C API<70>.
* Build: Build<83>.
* Tests: Tests<72>.

Python 3.6.0 beta 1

* Core and Builtins: Core and Builtins<181>.
* Library: Library<184>.
* IDLE: IDLE<52>.
* C API: C API<71>.
* Tests: Tests<73>.
* Build: Build<84>.
* Tools/Demos: Tools/Demos<51>.
* Windows: Windows<72>.

Python 3.6.0 alpha 4

* Core and Builtins: Core and Builtins<182>.
* Library: Library<185>.
* IDLE: IDLE<53>.
* Tests: Tests<74>.
* Windows: Windows<73>.
* Build: Build<85>.

Python 3.6.0 alpha 3

* Security: Security<54>.
* Core and Builtins: Core and Builtins<183>.
* Library: Library<186>.
* IDLE: IDLE<54>.
* C API: C API<72>.
* Build: Build<86>.
* Tools/Demos: Tools/Demos<52>.
* Documentation: Documentation<74>.
* Tests: Tests<75>.

Python 3.6.0 alpha 2

* Security: Security<55>.
* Core and Builtins: Core and Builtins<184>.
* Library: Library<187>.
* IDLE: IDLE<55>.
* Documentation: Documentation<75>.
* Tests: Tests<76>.
* Windows: Windows<74>.
* Build: Build<87>.
* C API: C API<73>.
* Tools/Demos: Tools/Demos<53>.

Python 3.6.0 alpha 1

* Security: Security<56>.
* Core and Builtins: Core and Builtins<185>.
* Library: Library<188>.
* IDLE: IDLE<56>.
* Documentation: Documentation<76>.
* Tests: Tests<77>.
* Build: Build<88>.
* Windows: Windows<75>.
* Tools/Demos: Tools/Demos<54>.
* C API: C API<74>.

Python 3.5.5 release candidate 1

* Security: Security<57>.
* Core and Builtins: Core and Builtins<186>.
* Library: Library<189>.

Python 3.5.4 final

* Library: Library<190>.

Python 3.5.4 release candidate 1

* Security: Security<58>.
* Core and Builtins: Core and Builtins<187>.
* Library: Library<191>.
* Documentation: Documentation<77>.
* Tests: Tests<78>.
* Build: Build<89>.
* Windows: Windows<76>.
* C API: C API<75>.

Python 3.5.3 release candidate 1

* Security: Security<59>.
* Core and Builtins: Core and Builtins<188>.
* Library: Library<192>.
* IDLE: IDLE<57>.
* C API: C API<76>.
* Documentation: Documentation<78>.
* Tests: Tests<79>.
* Tools/Demos: Tools/Demos<55>.
* Windows: Windows<77>.
* Build: Build<90>.

Python 3.5.2 final

* Core and Builtins: Core and Builtins<189>.
* Tests: Tests<80>.
* IDLE: IDLE<58>.

Python 3.5.2 release candidate 1

* Security: Security<60>.
* Core and Builtins: Core and Builtins<190>.
* Library: Library<193>.
* IDLE: IDLE<59>.
* Documentation: Documentation<79>.
* Tests: Tests<81>.
* Build: Build<91>.
* Windows: Windows<78>.
* Tools/Demos: Tools/Demos<56>.

Python 3.5.1 final

* Core and Builtins: Core and Builtins<191>.
* Windows: Windows<79>.

Python 3.5.1 release candidate 1

* Core and Builtins: Core and Builtins<192>.
* Library: Library<194>.
* IDLE: IDLE<60>.
* Documentation: Documentation<80>.
* Tests: Tests<82>.
* Build: Build<92>.
* Windows: Windows<80>.
* Tools/Demos: Tools/Demos<57>.

Python 3.5.0 final

* Build: Build<93>.

Python 3.5.0 release candidate 4

* Library: Library<195>.
* Build: Build<94>.

Python 3.5.0 release candidate 3

* Core and Builtins: Core and Builtins<193>.
* Library: Library<196>.

Python 3.5.0 release candidate 2

* Core and Builtins: Core and Builtins<194>.
* Library: Library<197>.

Python 3.5.0 release candidate 1

* Core and Builtins: Core and Builtins<195>.
* Library: Library<198>.
* IDLE: IDLE<61>.
* Documentation: Documentation<81>.
* Tests: Tests<83>.

Python 3.5.0 beta 4

* Core and Builtins: Core and Builtins<196>.
* Library: Library<199>.
* Build: Build<95>.

Python 3.5.0 beta 3

* Core and Builtins: Core and Builtins<197>.
* Library: Library<200>.
* Tests: Tests<84>.
* Documentation: Documentation<82>.
* Build: Build<96>.

Python 3.5.0 beta 2

* Core and Builtins: Core and Builtins<198>.
* Library: Library<201>.

Python 3.5.0 beta 1

* Core and Builtins: Core and Builtins<199>.
* Library: Library<202>.
* IDLE: IDLE<62>.
* Tests: Tests<85>.
* Documentation: Documentation<83>.
* Tools/Demos: Tools/Demos<58>.

Python 3.5.0 alpha 4

* Core and Builtins: Core and Builtins<200>.
* Library: Library<203>.
* Build: Build<97>.
* Tests: Tests<86>.
* Tools/Demos: Tools/Demos<59>.
* C API: C API<77>.

Python 3.5.0 alpha 3

* Core and Builtins: Core and Builtins<201>.
* Library: Library<204>.
* Build: Build<98>.
* Tests: Tests<87>.
* Tools/Demos: Tools/Demos<60>.

Python 3.5.0 alpha 2

* Core and Builtins: Core and Builtins<202>.
* Library: Library<205>.
* Build: Build<99>.
* C API: C API<78>.
* Windows: Windows<81>.

Python 3.5.0 alpha 1

* Core and Builtins: Core and Builtins<203>.
* Library: Library<206>.
* IDLE: IDLE<63>.
* Build: Build<100>.
* C API: C API<79>.
* Documentation: Documentation<84>.
* Tests: Tests<88>.
* Tools/Demos: Tools/Demos<61>.
* Windows: Windows<82>.

Tutorial su Python

* Stuzzichiamo il tuo appetito::
* Uso dell’interprete di Python::
* Un’introduzione informale a Python::
* Altri Strumenti di Controllo del Flusso::
* Strutture Dati::
* Moduli::
* Input e Output::
* Errori ed Eccezioni::
* Classi::
* Breve Panoramica della Libreria Standard::
* Giro Breve della Libreria Standard — Parte II::
* Ambienti Virtuali e Pacchetti::
* E adesso?::
* Editing dell’input interattivo e sostituzione della history::
* Floating-Point Arithmetic; Issues and Limitations: Floating-Point Arithmetic Issues and Limitations.
* Appendice::

Uso dell’interprete di Python

* Invocazione dell’interprete::
* L’interprete e il suo ambiente::

Invocazione dell’interprete

* Passare Argomenti::
* Modalità Interattiva::

L’interprete e il suo ambiente

* Codifica del codice sorgente::

Un’introduzione informale a Python

* Usare Python come calcolatrice::
* Primi passi di programmazione::

Usare Python come calcolatrice

* Numeri::
* Testo::
* Liste::

Altri Strumenti di Controllo del Flusso

* Istruzioni if::
* Istruzioni for::
* La Funzione range(): La Funzione range.
* break and continue Statements::
* else Clauses on Loops::
* Istruzioni pass::
* Istruzioni match::
* Definizione di Funzioni::
* Ulteriori informazioni sulla Definizione di Funzioni::
* Intermezzo; Stile di Codifica: Intermezzo Stile di Codifica.

Ulteriori informazioni sulla Definizione di Funzioni

* Valori predefiniti degli argomenti::
* Argomenti chiave-valore::
* Parametri speciali::
* Liste di Argomenti Arbitrarie::
* Spacchettamento delle Liste di Argomenti::
* Espressioni Lambda::
* Stringhe di Documentazione::
* Annotationi delle Funzioni::

Parametri speciali

* Argomenti Posizionali o per Chiave::
* Parametri Solo per Posizione::
* Argomenti Solo per Chiave::
* Esempi di Funzioni::
* Riepilogo::

Strutture Dati

* Più sulle Liste::
* L’istruzione del::
* Tuple e Sequenze::
* Insiemi::
* Dizionari::
* Tecniche di Looping::
* Maggiori informazioni sulle Condizioni::
* Confronto tra Sequenze e Altri Tipi::

Più sulle Liste

* Usare le Liste come Pile::
* Usare le Liste come Code::
* Comprensioni di Lista::
* Comprensioni di Lista Nidificate::

Moduli

* Più sui Moduli::
* Moduli Standard::
* La funzione dir(): La funzione dir.
* Pacchetti::

Più sui Moduli

* Esecuzione di moduli come script::
* Il percorso di ricerca del modulo::
* File Python «compilati»::

Pacchetti

* Importare * Da un Pacchetto::
* Riferimenti Intra-pacchetto::
* Pacchetti in Directory Multiple::

Input e Output

* Formattazione Avanzata dell’Output::
* Lettura e Scrittura di File::

Formattazione Avanzata dell’Output

* Stringhe Formattate Letterali::
* Il Metodo String format(): Il Metodo String format.
* Formattazione Manuale delle Stringhe::
* Vecchia formattazione delle stringhe::

Lettura e Scrittura di File

* Metodi degli Oggetti File::
* Salvare dati strutturati con json::

Errori ed Eccezioni

* Errori di Sintassi::
* Eccezioni::
* Gestione delle Eccezioni::
* Sollevare Eccezioni::
* Collegamento delle Eccezioni::
* Eccezioni Definite dall’Utente::
* Definizione di Azioni di Pulizia::
* Azioni di Pulizia Predefinite::
* Sollevare e Gestire Eccezioni Multiple e Non Correlate::
* Arricchire le Eccezioni con Note::

Classi

* Una parola su nomi e oggetti::
* Visibilità e spazi dei nomi in Python::
* Una prima occhiata alle classi::
* Osservazioni Varie::
* Ereditarietà::
* Variabili Private::
* Varie ed Eventuali::
* Iteratori::
* Generatori::
* Espressioni di Generatore::

Visibilità e spazi dei nomi in Python

* Esempio di visibilità e spazi dei nomi::

Una prima occhiata alle classi

* Sintassi della definizione di classe::
* Oggetti della Classe::
* Oggetti Istanza::
* Oggetti Metodo::
* Variabili di Classe e Istanza::

Ereditarietà

* Ereditarietà Multipla::

Breve Panoramica della Libreria Standard

* Interfaccia del Sistema Operativo::
* Metacaratteri nei Nomfile::
* Argomenti dalla Linea di Comando::
* Reindirizzamento dell’Uscita degli Errori e Terminazione del Programma::
* Pattern Matching di Stringhe::
* Matematica::
* Accesso a Internet::
* Date e Orari::
* Compressione dei Dati::
* Misurazione delle Prestazioni::
* Controllo della Qualità::
* Batterie Incluse::

Giro Breve della Libreria Standard — Parte II

* Formattazione dell’Output::
* Templating::
* Lavorare con Layout Binari dei Dati::
* Multi-threading: Multi-threading<2>.
* Logging::
* Riferimenti Deboli::
* Strumenti per Lavorare con Liste::
* Decimal Floating-Point Arithmetic::

Ambienti Virtuali e Pacchetti

* Introduzione::
* Creazione di Ambienti Virtuali::
* Gestione dei Pacchetti con pip::

Editing dell’input interattivo e sostituzione della history

* Completamento con il tasto Tab e modifica della history::
* Alternative all’interprete interattivo::

Floating-Point Arithmetic:  Issues and Limitations

* Errore di Rappresentazione::

Appendice

* Modalità Interattiva: Modalità Interattiva<2>.

Modalità Interattiva

* Gestione degli Errori::
* Script Eseguibili Python::
* Il File di Avvio Interattivo::
* I Moduli di Personalizzazione::

Python Setup and Usage

* Command line and environment: Command line and environment<2>.
* Using Python on Unix platforms::
* Configure Python::
* Using Python on Windows::
* Using Python on macOS::
* Using Python on Android::
* Using Python on iOS::
* Editors and IDEs::

Command line and environment

* Command line::
* Environment variables::

Command line

* Interface options::
* Generic options::
* Miscellaneous options::
* Controlling color::

Environment variables

* Debug-mode variables::

Using Python on Unix platforms

* Getting and installing the latest version of Python::
* Building Python::
* Python-related paths and files::
* Miscellaneous::
* Custom OpenSSL::

Getting and installing the latest version of Python

* On Linux::
* On FreeBSD and OpenBSD::

On Linux

* Installing IDLE::

Configure Python

* Build Requirements::
* Generated files::
* Configure Options::
* Python Build System::
* Compiler and linker flags::

Build Requirements

* Requirements for optional modules::

Generated files

* configure script::

Configure Options

* General Options::
* C compiler options::
* Linker options::
* Options for third-party dependencies::
* WebAssembly Options::
* Install Options::
* Performance options::
* Python Debug Build::
* Debug options::
* Linker options: Linker options<2>.
* Libraries options::
* Security Options::
* macOS Options::
* iOS Options::
* Cross Compiling Options::

Python Build System

* Main files of the build system::
* Main build steps::
* Main Makefile targets::
* C extensions::

Main Makefile targets

* make::
* make platform::
* make profile-opt::
* make clean::
* make distclean::
* make install::
* make test::
* make ci::
* make buildbottest::
* make regen-all::

Compiler and linker flags

* Preprocessor flags::
* Compiler flags::
* Linker flags::

Using Python on Windows

* Python install manager::
* The embeddable package::
* The nuget.org packages: The nuget org packages.
* Alternative bundles::
* Supported Windows versions::
* Removing the MAX_PATH limitation::
* UTF-8 mode::
* Finding modules::
* Additional modules::
* Compiling Python on Windows::
* The full installer (deprecated): The full installer deprecated.
* Python launcher for Windows (deprecated): Python launcher for Windows deprecated.

Python install manager

* Installation::
* Basic use::
* Command help::
* Listing runtimes::
* Installing runtimes::
* Offline installs::
* Uninstalling runtimes::
* Configuration::
* Shebang lines::
* Advanced installation::
* Administrative configuration::
* Installing free-threaded binaries::
* Troubleshooting::

The embeddable package

* Python application::
* Embedding Python::

The nuget.org packages

* Free-threaded packages::

Additional modules

* PyWin32::
* cx_Freeze::

The full installer (deprecated)

* Installation steps::
* Removing the MAX_PATH limitation: Removing the MAX_PATH limitation<2>.
* Installing without UI::
* Installing without downloading::
* Modifying an install::
* Installing free-threaded binaries: Installing free-threaded binaries<2>.

Python launcher for Windows (deprecated)

* Getting started::
* Shebang lines: Shebang lines<2>.
* Arguments in shebang lines::
* Customization::
* Diagnostics::
* Dry run::
* Install on demand::
* Return codes::

Getting started

* From the command-line::
* Virtual environments::
* From a script::
* From file associations::

Customization

* Customization via INI files::
* Customizing default Python versions::

Using Python on macOS

* Using Python for macOS from python.org: Using Python for macOS from python org.
* Alternative Distributions::
* Installing Additional Python Packages::
* GUI Programming::
* Advanced Topics::
* Other Resources::

Using Python for macOS from python.org

* Installation steps: Installation steps<2>.
* How to run a Python script::

Advanced Topics

* Installing Free-threaded Binaries::
* Installing using the command line::
* Distributing Python Applications::
* App Store Compliance::

Using Python on Android

* Adding Python to an Android app::
* Building a Python package for Android::

Using Python on iOS

* Python at runtime on iOS::
* Installing Python on iOS::
* App Store Compliance: App Store Compliance<2>.

Python at runtime on iOS

* iOS version compatibility::
* Platform identification::
* Standard library availability::
* Binary extension modules::
* Compiler stub binaries::

Installing Python on iOS

* Tools for building iOS apps::
* Adding Python to an iOS project::
* Testing a Python package::

App Store Compliance

* Incompatible code in the standard library::
* Privacy manifests::

Editors and IDEs

* IDLE — Python editor and shell::
* Other Editors and IDEs::

The Python Language Reference

* Introduction: Introduction<4>.
* Lexical analysis::
* Data model::
* Execution model::
* The import system::
* Expressions::
* Simple statements::
* Compound statements::
* Top-level components::
* Full Grammar specification::

Introduction

* Alternate Implementations::
* Notation::

Notation

* Lexical and Syntactic definitions::

Lexical analysis

* Line structure::
* Other tokens::
* Names (identifiers and keywords): Names identifiers and keywords.
* Literals::
* String and Bytes literals::
* Numeric literals::
* Operators and delimiters::

Line structure

* Logical lines::
* Physical lines::
* Comments::
* Encoding declarations::
* Explicit line joining::
* Implicit line joining::
* Blank lines::
* Indentation::
* Whitespace between tokens::
* End marker::

Names (identifiers and keywords)

* Keywords::
* Soft Keywords::
* Reserved classes of identifiers::
* Non-ASCII characters in names::

String and Bytes literals

* Triple-quoted strings::
* String prefixes::
* Formal grammar::
* Escape sequences::
* Bytes literals::
* Raw string literals::
* f-strings::
* t-strings::
* Formal grammar for f-strings::

Escape sequences

* Ignored end of line::
* Escaped characters::
* Octal character::
* Hexadecimal character::
* Named Unicode character::
* Hexadecimal Unicode characters::
* Unrecognized escape sequences::

Numeric literals

* Integer literals::
* Floating-point literals::
* Imaginary literals::

Data model

* Objects, values and types: Objects values and types.
* The standard type hierarchy::
* Special method names::
* Coroutines::

The standard type hierarchy

* None::
* NotImplemented::
* Ellipsis::
* numbers.Number: numbers Number.
* Sequences::
* Set types::
* Mappings::
* Callable types::
* Modules: Modules<2>.
* Custom classes::
* Class instances::
* I/O objects (also known as file objects): I/O objects also known as file objects.
* Internal types::

numbers.Number

* numbers.Integral: numbers Integral.
* numbers.Real (float): numbers Real float.
* numbers.Complex (complex): numbers Complex complex.

Sequences

* Immutable sequences::
* Mutable sequences::

Mappings

* Dictionaries::

Callable types

* User-defined functions::
* Instance methods::
* Generator functions::
* Coroutine functions::
* Asynchronous generator functions::
* Built-in functions::
* Built-in methods::
* Classes::
* Class Instances::

User-defined functions

* Special read-only attributes::
* Special writable attributes::

Modules

* Import-related attributes on module objects::
* Other writable attributes on module objects::
* Module dictionaries::

Custom classes

* Special attributes::
* Special methods::

Class instances

* Special attributes: Special attributes<2>.

Internal types

* Code objects::
* Frame objects::
* Traceback objects::
* Slice objects::
* Static method objects::
* Class method objects::

Code objects

* Special read-only attributes: Special read-only attributes<2>.
* Methods on code objects::

Frame objects

* Special read-only attributes: Special read-only attributes<3>.
* Special writable attributes: Special writable attributes<2>.
* Frame object methods::

Special method names

* Basic customization::
* Customizing attribute access::
* Customizing class creation::
* Customizing instance and subclass checks::
* Emulating generic types::
* Emulating callable objects::
* Emulating container types::
* Emulating numeric types::
* With Statement Context Managers::
* Customizing positional arguments in class pattern matching::
* Emulating buffer types::
* Annotations::
* Special method lookup::

Customizing attribute access

* Customizing module attribute access::
* Implementing Descriptors::
* Invoking Descriptors::
* __slots__: __slots__<2>.

Customizing class creation

* Metaclasses::
* Resolving MRO entries::
* Determining the appropriate metaclass::
* Preparing the class namespace::
* Executing the class body::
* Creating the class object::
* Uses for metaclasses::

Emulating generic types

* The purpose of __class_getitem__::
* __class_getitem__ versus __getitem__::

Coroutines

* Awaitable Objects::
* Coroutine Objects::
* Asynchronous Iterators::
* Asynchronous Context Managers::

Execution model

* Structure of a program::
* Naming and binding::
* Exceptions::
* Runtime Components::

Naming and binding

* Binding of names::
* Resolution of names::
* Annotation scopes::
* Lazy evaluation::
* Builtins and restricted execution::
* Interaction with dynamic features::

Runtime Components

* General Computing Model::
* Python Runtime Model::

The import system

* importlib: importlib<10>.
* Packages::
* Searching::
* Loading::
* The Path Based Finder::
* Replacing the standard import system::
* Package Relative Imports::
* Special considerations for __main__::
* References::

Packages

* Regular packages::
* Namespace packages::

Searching

* The module cache::
* Finders and loaders::
* Import hooks::
* The meta path::

Loading

* Loaders::
* Submodules::
* Module specs::
* __path__ attributes on modules::
* Module reprs::
* Cached bytecode invalidation::

The Path Based Finder

* Path entry finders::
* Path entry finder protocol::

Special considerations for __main__

* __main__.__spec__: __main__ __spec__.

Expressions

* Arithmetic conversions::
* Atoms::
* Primaries::
* Await expression::
* The power operator::
* Unary arithmetic and bitwise operations::
* Binary arithmetic operations::
* Shifting operations::
* Binary bitwise operations::
* Comparisons::
* Boolean operations::
* Assignment expressions: Assignment expressions<2>.
* Conditional expressions::
* Lambdas::
* Expression lists::
* Evaluation order::
* Operator precedence::

Atoms

* Identifiers (Names): Identifiers Names.
* Literals: Literals<2>.
* Parenthesized forms::
* Displays for lists, sets and dictionaries: Displays for lists sets and dictionaries.
* List displays::
* Set displays::
* Dictionary displays::
* Generator expressions::
* Yield expressions::

Identifiers (Names)

* Private name mangling::

Literals

* String literal concatenation::

Yield expressions

* Generator-iterator methods::
* Examples::
* Asynchronous generator functions: Asynchronous generator functions<2>.
* Asynchronous generator-iterator methods::

Primaries

* Attribute references::
* Subscriptions::
* Slicings::
* Calls::

Comparisons

* Value comparisons::
* Membership test operations::
* Identity comparisons::

Simple statements

* Expression statements::
* Assignment statements::
* The assert statement::
* The pass statement::
* The del statement::
* The return statement::
* The yield statement::
* The raise statement::
* The break statement::
* The continue statement::
* The import statement::
* The global statement::
* The nonlocal statement::
* The type statement::

Assignment statements

* Augmented assignment statements::
* Annotated assignment statements::

The import statement

* Future statements::

Compound statements

* The if statement::
* The while statement::
* The for statement::
* The try statement::
* The with statement::
* The match statement::
* Function definitions::
* Class definitions::
* Coroutines: Coroutines<2>.
* Type parameter lists::
* Annotations: Annotations<2>.

The try statement

* except clause::
* except* clause::
* else clause::
* finally clause::

The match statement

* Overview::
* Guards::
* Irrefutable Case Blocks::
* Patterns::

Patterns

* OR Patterns::
* AS Patterns::
* Literal Patterns::
* Capture Patterns::
* Wildcard Patterns::
* Value Patterns::
* Group Patterns::
* Sequence Patterns::
* Mapping Patterns::
* Class Patterns::

Coroutines

* Coroutine function definition::
* The async for statement::
* The async with statement::

Type parameter lists

* Generic functions::
* Generic classes::
* Generic type aliases::

Top-level components

* Complete Python programs::
* File input::
* Interactive input::
* Expression input::

The Python Standard Library

* Introduction: Introduction<5>.
* Funzioni Incorporate::
* Built-in Constants::
* Tipi incorporati::
* Built-in Exceptions::
* Text Processing Services::
* Binary Data Services::
* Data Types::
* Numeric and Mathematical Modules::
* Functional Programming Modules::
* File and Directory Access::
* Data Persistence::
* Data Compression and Archiving::
* File Formats::
* Cryptographic Services::
* Generic Operating System Services::
* Command-line interface libraries::
* Concurrent Execution::
* Networking and Interprocess Communication::
* Internet Data Handling::
* Structured Markup Processing Tools::
* Internet Protocols and Support::
* Multimedia Services::
* Internationalization::
* Graphical user interfaces with Tk::
* Development Tools::
* Debugging and Profiling::
* Software Packaging and Distribution::
* Python Runtime Services::
* Custom Python Interpreters::
* Importing Modules::
* Python Language Services::
* MS Windows Specific Services::
* Unix-specific services::
* Modules command-line interface (CLI): Modules command-line interface CLI.
* Superseded Modules::
* Removed Modules::
* Security Considerations: Security Considerations<3>.

Introduction

* Notes on availability::

Notes on availability

* WebAssembly platforms::
* Mobile platforms::

Built-in Constants

* Constants added by the site module::

Tipi incorporati

* Test del Valore di Verità::
* Operazioni Booleane — and, or, not: Operazioni Booleane — and or not.
* Confronti::
* Tipi Numerici — int, float, complex: Tipi Numerici — int float complex.
* Tipo Booleano - bool::
* Tipi di Iteratore::
* Tipi di Sequenza — list, tuple, range: Tipi di Sequenza — list tuple range.
* Text and Binary Sequence Type Methods Summary::
* Tipo Sequenza di Testo — str::
* Tipi di sequenze binarie — bytes, bytearray, memoryview: Tipi di sequenze binarie — bytes bytearray memoryview.
* Tipi di Insiemi — set, frozenset: Tipi di Insiemi — set frozenset.
* Tipi di Mapping — dict::
* Tipi di gestori di contesti::
* Tipi di annotazione di tipo — Alias generico, Union: Tipi di annotazione di tipo — Alias generico Union.
* Altri Tipi Integrati::
* Attributi Speciali::
* Limitazione della lunghezza di conversione delle stringhe di interi::

Tipi Numerici — int, float, complex

* Operazioni Bitwise sui Tipi Integer::
* Metodi Aggiuntivi sui Tipi Integer::
* Metodi aggiuntivi su Float::
* Additional Methods on Complex::
* Hashing dei tipi numerici::

Tipi di Iteratore

* Tipi di Generatore::

Tipi di Sequenza — list, tuple, range

* Operazioni Comuni sulle Sequenze::
* Tipi di Sequenza Immutabili::
* Tipi di Sequenza Mutabili::
* Liste: Liste<2>.
* Tuple::
* Intervalli::

Tipo Sequenza di Testo — str

* Metodi per le Stringhe::
* Formatted String Literals (f-strings): Formatted String Literals f-strings.
* Template String Literals (t-strings): Template String Literals t-strings.
* Formattazione delle stringhe in stile printf::

Formatted String Literals (f-strings)

* Debug specifier::
* Conversion specifier::
* Format specifier::

Tipi di sequenze binarie — bytes, bytearray, memoryview

* Oggetti bytes::
* Oggetti Bytearray::
* Operazioni su Bytes e Bytearray::
* Formattazione Bytes stile printf::
* Memory Views::

Tipi di Mapping — dict

* Oggetti vista del dizionario::

Tipi di annotazione di tipo — Alias generico, Union

* Tipo Generic Alias::
* Tipo Unione::

Tipo Generic Alias

* Classi Generiche Standard::
* Attributi Speciali per oggetti GenericAlias::

Altri Tipi Integrati

* Moduli: Moduli<2>.
* Classi e Istanze di Classe::
* Funzioni::
* Metodi::
* Oggetti Codice::
* Oggetti Tipo::
* L’Oggetto Null::
* L’Oggetto Ellipsis::
* L’Oggetto NotImplemented::
* Oggetti Interni::

Limitazione della lunghezza di conversione delle stringhe di interi

* API influenzate::
* Configurazione del limite::
* Configurazione consigliata::

Built-in Exceptions

* Exception context::
* Inheriting from built-in exceptions::
* Base classes::
* Concrete exceptions::
* Warnings::
* Exception groups::
* Exception hierarchy::

Concrete exceptions

* OS exceptions::

Text Processing Services

* string — Common string operations::
* string.templatelib — Support for template string literals: string templatelib — Support for template string literals.
* re — Regular expression operations::
* difflib — Helpers for computing deltas::
* textwrap — Text wrapping and filling::
* unicodedata — Unicode Database::
* stringprep — Internet String Preparation::
* readline — GNU readline interface::
* rlcompleter — Completion function for GNU readline::

string — Common string operations

* String constants::
* Custom String Formatting::
* Format String Syntax::
* Template strings ($-strings): Template strings $-strings.
* Helper functions::

Format String Syntax

* Format Specification Mini-Language::
* Format examples::

string.templatelib — Support for template string literals

* Template strings::
* Types::
* Helper functions: Helper functions<2>.

re — Regular expression operations

* Regular Expression Syntax::
* Module Contents::
* Regular Expression Objects::
* Match Objects::
* Regular Expression Examples::

Module Contents

* Flags::
* Functions::
* Exceptions: Exceptions<2>.

Regular Expression Examples

* Checking for a Pair::
* Simulating scanf(): Simulating scanf.
* search() vs. match(): search vs match.
* Making a Phonebook::
* Text Munging::
* Finding all Adverbs::
* Finding all Adverbs and their Positions::
* Raw String Notation::
* Writing a Tokenizer::

difflib — Helpers for computing deltas

* SequenceMatcher Objects::
* SequenceMatcher Examples::
* Differ Objects::
* Differ Example::
* A command-line interface to difflib::
* ndiff example::

readline — GNU readline interface

* Init file::
* Line buffer::
* History file::
* History list::
* Startup hooks::
* Completion::
* Example::

Binary Data Services

* struct — Interpret bytes as packed binary data::
* codecs — Codec registry and base classes::

struct — Interpret bytes as packed binary data

* Functions and Exceptions::
* Format Strings::
* Applications::
* Classes: Classes<2>.

Format Strings

* Byte Order, Size, and Alignment: Byte Order Size and Alignment.
* Format Characters::
* Examples: Examples<2>.

Applications

* Native Formats::
* Standard Formats::

codecs — Codec registry and base classes

* Codec Base Classes::
* Encodings and Unicode::
* Standard Encodings::
* Python Specific Encodings::
* encodings — Encodings package::
* encodings.idna — Internationalized Domain Names in Applications: encodings idna — Internationalized Domain Names in Applications.
* encodings.mbcs — Windows ANSI codepage: encodings mbcs — Windows ANSI codepage.
* encodings.utf_8_sig — UTF-8 codec with BOM signature: encodings utf_8_sig — UTF-8 codec with BOM signature.

Codec Base Classes

* Error Handlers::
* Stateless Encoding and Decoding::
* Incremental Encoding and Decoding::
* Stream Encoding and Decoding::

Incremental Encoding and Decoding

* IncrementalEncoder Objects::
* IncrementalDecoder Objects::

Stream Encoding and Decoding

* StreamWriter Objects::
* StreamReader Objects::
* StreamReaderWriter Objects::
* StreamRecoder Objects::

Python Specific Encodings

* Text Encodings::
* Binary Transforms::
* Standalone Codec Functions::
* Text Transforms::

Data Types

* datetime — Basic date and time types::
* zoneinfo — IANA time zone support::
* calendar — General calendar-related functions::
* collections — Container datatypes::
* collections.abc — Abstract Base Classes for Containers: collections abc — Abstract Base Classes for Containers.
* heapq — Heap queue algorithm::
* bisect — Array bisection algorithm::
* array — Efficient arrays of numeric values::
* weakref — Weak references::
* types — Dynamic type creation and names for built-in types::
* copy — Shallow and deep copy operations::
* pprint — Data pretty printer::
* reprlib — Alternate repr() implementation: reprlib — Alternate repr implementation.
* enum — Support for enumerations::
* graphlib — Functionality to operate with graph-like structures::

datetime — Basic date and time types

* Aware and Naive Objects::
* Constants::
* Available Types::
* timedelta Objects::
* date Objects::
* datetime Objects::
* time Objects::
* tzinfo Objects::
* timezone Objects::
* strftime() and strptime() Behavior: strftime and strptime Behavior.

Available Types

* Common Properties::
* Determining if an Object is Aware or Naive::

timedelta Objects

* Examples of usage; timedelta: Examples of usage timedelta.

date Objects

* Examples of Usage; date: Examples of Usage date.

datetime Objects

* Examples of Usage; datetime: Examples of Usage datetime.

time Objects

* Examples of Usage; time: Examples of Usage time.

strftime() and strptime() Behavior

* strftime() and strptime() Format Codes: strftime and strptime Format Codes.
* Technical Detail::

zoneinfo — IANA time zone support

* Using ZoneInfo::
* Data sources::
* The ZoneInfo class::
* Functions: Functions<2>.
* Globals::
* Exceptions and warnings::

Data sources

* Configuring the data sources::

Configuring the data sources

* Compile-time configuration::
* Environment configuration::
* Runtime configuration::

The ZoneInfo class

* String representations::
* Pickle serialization::

calendar — General calendar-related functions

* Command-line usage::

collections — Container datatypes

* ChainMap objects::
* Counter objects::
* deque objects::
* defaultdict objects::
* namedtuple() Factory Function for Tuples with Named Fields: namedtuple Factory Function for Tuples with Named Fields.
* OrderedDict objects::
* UserDict objects::
* UserList objects::
* UserString objects::

ChainMap objects

* ChainMap Examples and Recipes::

deque objects

* deque Recipes::

defaultdict objects

* defaultdict Examples::

OrderedDict objects

* OrderedDict Examples and Recipes::

collections.abc — Abstract Base Classes for Containers

* Collections Abstract Base Classes::
* Collections Abstract Base Classes – Detailed Descriptions::
* Examples and Recipes::

heapq — Heap queue algorithm

* Basic Examples::
* Other Applications::
* Priority Queue Implementation Notes::
* Theory::

bisect — Array bisection algorithm

* Performance Notes::
* Searching Sorted Lists::
* Examples: Examples<3>.

weakref — Weak references

* Weak Reference Objects::
* Example: Example<2>.
* Finalizer Objects::
* Comparing finalizers with __del__() methods: Comparing finalizers with __del__ methods.

types — Dynamic type creation and names for built-in types

* Dynamic Type Creation::
* Standard Interpreter Types::
* Additional Utility Classes and Functions::
* Coroutine Utility Functions::

pprint — Data pretty printer

* Functions: Functions<3>.
* PrettyPrinter Objects::
* Example: Example<3>.

reprlib — Alternate repr() implementation

* Repr Objects::
* Subclassing Repr Objects::

enum — Support for enumerations

* Module Contents: Module Contents<2>.
* Data Types: Data Types<2>.
* Utilities and Decorators::
* Notes::

Data Types

* Supported __dunder__ names::
* Supported _sunder_ names::

graphlib — Functionality to operate with graph-like structures

* Exceptions: Exceptions<3>.

Numeric and Mathematical Modules

* numbers — Numeric abstract base classes::
* math — Mathematical functions::
* cmath — Mathematical functions for complex numbers::
* decimal — Decimal fixed-point and floating-point arithmetic::
* fractions — Rational numbers::
* random — Generate pseudo-random numbers::
* statistics — Mathematical statistics functions::

numbers — Numeric abstract base classes

* The numeric tower::
* Notes for type implementers::

Notes for type implementers

* Adding More Numeric ABCs::
* Implementing the arithmetic operations::

math — Mathematical functions

* Number-theoretic functions::
* Floating point arithmetic::
* Floating point manipulation functions::
* Power, exponential and logarithmic functions: Power exponential and logarithmic functions.
* Summation and product functions::
* Angular conversion::
* Trigonometric functions::
* Hyperbolic functions::
* Special functions::
* Constants: Constants<2>.

cmath — Mathematical functions for complex numbers

* Conversions to and from polar coordinates::
* Power and logarithmic functions::
* Trigonometric functions: Trigonometric functions<2>.
* Hyperbolic functions: Hyperbolic functions<2>.
* Classification functions::
* Constants: Constants<3>.

decimal — Decimal fixed-point and floating-point arithmetic

* Quick-start tutorial::
* Decimal objects::
* Context objects::
* Constants: Constants<4>.
* Rounding modes::
* Signals::
* Floating-point notes::
* Working with threads::
* Recipes::
* Decimal FAQ::

Decimal objects

* Logical operands::

Floating-point notes

* Mitigating round-off error with increased precision::
* Special values::

random — Generate pseudo-random numbers

* Bookkeeping functions::
* Functions for bytes::
* Functions for integers::
* Functions for sequences::
* Discrete distributions::
* Real-valued distributions::
* Alternative Generator::
* Notes on Reproducibility::
* Examples: Examples<4>.
* Recipes: Recipes<2>.
* Command-line usage: Command-line usage<2>.
* Command-line example::

statistics — Mathematical statistics functions

* Averages and measures of central location::
* Measures of spread::
* Statistics for relations between two inputs::
* Function details::
* Exceptions: Exceptions<4>.
* NormalDist objects::
* Examples and Recipes: Examples and Recipes<2>.

Examples and Recipes

* Classic probability problems::
* Monte Carlo inputs for simulations::
* Approximating binomial distributions::
* Naive bayesian classifier::

Functional Programming Modules

* itertools — Functions creating iterators for efficient looping::
* functools — Higher-order functions and operations on callable objects::
* operator — Standard operators as functions::

itertools — Functions creating iterators for efficient looping

* Itertool Functions::
* Itertools Recipes::

functools — Higher-order functions and operations on callable objects

* partial Objects::

operator — Standard operators as functions

* Mapping Operators to Functions::
* In-place Operators::

File and Directory Access

* pathlib — Object-oriented filesystem paths::
* os.path — Common pathname manipulations: os path — Common pathname manipulations.
* stat — Interpreting stat() results: stat — Interpreting stat results.
* filecmp — File and Directory Comparisons::
* tempfile — Generate temporary files and directories::
* glob — Unix style pathname pattern expansion::
* fnmatch — Unix filename pattern matching::
* linecache — Random access to text lines::
* shutil — High-level file operations::

pathlib — Object-oriented filesystem paths

* Basic use: Basic use<2>.
* Exceptions: Exceptions<5>.
* Pure paths::
* Concrete paths::
* Pattern language::
* Comparison to the glob module::
* Comparison to the os and os.path modules: Comparison to the os and os path modules.
* Protocols::

Pure paths

* General properties::
* Operators::
* Accessing individual parts::
* Methods and properties::

Concrete paths

* Parsing and generating URIs::
* Expanding and resolving paths::
* Querying file type and status::
* Reading and writing files::
* Reading directories::
* Creating files and directories::
* Copying, moving and deleting: Copying moving and deleting.
* Permissions and ownership::

Comparison to the os and os.path modules

* Corresponding tools::

filecmp — File and Directory Comparisons

* The dircmp class::

tempfile — Generate temporary files and directories

* Examples: Examples<5>.
* Deprecated functions and variables::

glob — Unix style pathname pattern expansion

* Examples: Examples<6>.

shutil — High-level file operations

* Directory and files operations::
* Archiving operations::
* Querying the size of the output terminal::

Directory and files operations

* Platform-dependent efficient copy operations::
* copytree example::
* rmtree example::

Archiving operations

* Archiving example::
* Archiving example with base_dir::

Data Persistence

* pickle — Python object serialization::
* copyreg — Register pickle support functions::
* shelve — Python object persistence::
* marshal — Internal Python object serialization::
* dbm — Interfaces to Unix «databases»::
* sqlite3 — DB-API 2.0 interface for SQLite databases: sqlite3 — DB-API 2 0 interface for SQLite databases.

pickle — Python object serialization

* Relationship to other Python modules::
* Data stream format::
* Module Interface::
* What can be pickled and unpickled?::
* Pickling Class Instances::
* Custom Reduction for Types, Functions, and Other Objects: Custom Reduction for Types Functions and Other Objects.
* Out-of-band Buffers::
* Restricting Globals::
* Performance: Performance<2>.
* Examples: Examples<7>.
* Command-line interface::

Relationship to other Python modules

* Comparison with marshal::
* Comparison with json::

Pickling Class Instances

* Persistence of External Objects::
* Dispatch Tables::
* Handling Stateful Objects::

Out-of-band Buffers

* Provider API::
* Consumer API::
* Example: Example<4>.

copyreg — Register pickle support functions

* Example: Example<5>.

shelve — Python object persistence

* Restrictions::
* Example: Example<6>.

dbm — Interfaces to Unix «databases»

* dbm.sqlite3 — SQLite backend for dbm: dbm sqlite3 — SQLite backend for dbm.
* dbm.gnu — GNU database manager: dbm gnu — GNU database manager.
* dbm.ndbm — New Database Manager: dbm ndbm — New Database Manager.
* dbm.dumb — Portable DBM implementation: dbm dumb — Portable DBM implementation.

sqlite3 — DB-API 2.0 interface for SQLite databases

* Tutorial::
* Reference::
* How-to guides::
* Explanation::

Reference

* Module functions::
* Module constants::
* Connection objects::
* Cursor objects::
* Row objects::
* Blob objects::
* PrepareProtocol objects::
* Exceptions: Exceptions<6>.
* SQLite and Python types::
* Default adapters and converters (deprecated): Default adapters and converters deprecated.
* Command-line interface: Command-line interface<2>.

How-to guides

* How to use placeholders to bind values in SQL queries::
* How to adapt custom Python types to SQLite values::
* How to convert SQLite values to custom Python types::
* Adapter and converter recipes::
* How to use connection shortcut methods::
* How to use the connection context manager::
* How to work with SQLite URIs::
* How to create and use row factories::
* How to handle non-UTF-8 text encodings::

How to adapt custom Python types to SQLite values

* How to write adaptable objects::
* How to register adapter callables::

Explanation

* Transaction control::

Transaction control

* Transaction control via the autocommit attribute::
* Transaction control via the isolation_level attribute::

Data Compression and Archiving

* The compression package::
* compression.zstd — Compression compatible with the Zstandard format: compression zstd — Compression compatible with the Zstandard format.
* zlib — Compression compatible with gzip::
* gzip — Support for gzip files::
* bz2 — Support for bzip2 compression::
* lzma — Compression using the LZMA algorithm::
* zipfile — Work with ZIP archives::
* tarfile — Read and write tar archive files::

compression.zstd — Compression compatible with the Zstandard format

* Exceptions: Exceptions<7>.
* Reading and writing compressed files::
* Compressing and decompressing data in memory::
* Zstandard dictionaries::
* Advanced parameter control::
* Miscellaneous: Miscellaneous<2>.
* Examples: Examples<8>.

gzip — Support for gzip files

* Examples of usage::
* Command-line interface: Command-line interface<3>.

Command-line interface

* Command-line options::

bz2 — Support for bzip2 compression

* (De)compression of files: De compression of files.
* Incremental (de)compression: Incremental de compression.
* One-shot (de)compression: One-shot de compression.
* Examples of usage: Examples of usage<2>.

lzma — Compression using the LZMA algorithm

* Reading and writing compressed files: Reading and writing compressed files<2>.
* Compressing and decompressing data in memory: Compressing and decompressing data in memory<2>.
* Miscellaneous: Miscellaneous<3>.
* Specifying custom filter chains::
* Examples: Examples<9>.

zipfile — Work with ZIP archives

* ZipFile objects::
* Path objects::
* PyZipFile objects::
* ZipInfo objects::
* Command-line interface: Command-line interface<4>.
* Decompression pitfalls::

Command-line interface

* Command-line options: Command-line options<2>.

Decompression pitfalls

* From file itself::
* File system limitations::
* Resources limitations::
* Interruption::
* Default behaviors of extraction::

tarfile — Read and write tar archive files

* TarFile Objects::
* TarInfo Objects::
* Extraction filters::
* Command-Line Interface::
* Examples: Examples<10>.
* Supported tar formats::
* Unicode issues::

Extraction filters

* Default named filters::
* Filter errors::
* Hints for further verification::
* Supporting older Python versions::
* Stateful extraction filter example::

Command-Line Interface

* Command-line options: Command-line options<3>.

Examples

* Reading examples::
* Writing examples::

File Formats

* csv — CSV File Reading and Writing::
* configparser — Configuration file parser::
* tomllib — Parse TOML files::
* netrc — netrc file processing::
* plistlib — Generate and parse Apple .plist files: plistlib — Generate and parse Apple plist files.

csv — CSV File Reading and Writing

* Module Contents: Module Contents<3>.
* Dialects and Formatting Parameters::
* Reader Objects::
* Writer Objects::
* Examples: Examples<11>.

configparser — Configuration file parser

* Quick Start::
* Supported Datatypes::
* Fallback Values::
* Supported INI File Structure::
* Unnamed Sections::
* Interpolation of values::
* Mapping Protocol Access::
* Customizing Parser Behaviour::
* Legacy API Examples::
* ConfigParser Objects::
* RawConfigParser Objects::
* Exceptions: Exceptions<8>.

tomllib — Parse TOML files

* Examples: Examples<12>.
* Conversion Table::

netrc — netrc file processing

* netrc Objects::

plistlib — Generate and parse Apple .plist files

* Examples: Examples<13>.

Cryptographic Services

* hashlib — Secure hashes and message digests::
* hmac — Keyed-Hashing for Message Authentication::
* secrets — Generate secure random numbers for managing secrets::

hashlib — Secure hashes and message digests

* Hash algorithms::
* Usage::
* Constructors::
* Attributes::
* Hash Objects::
* SHAKE variable length digests::
* File hashing::
* Key derivation::
* BLAKE2::

BLAKE2

* Creating hash objects::
* Constants: Constants<5>.
* Examples: Examples<14>.
* Credits::

Examples

* Simple hashing::
* Using different digest sizes::
* Keyed hashing::
* Randomized hashing::
* Personalization::
* Tree mode::

secrets — Generate secure random numbers for managing secrets

* Random numbers::
* Generating tokens::
* Other functions::
* Recipes and best practices::

Generating tokens

* How many bytes should tokens use?::

Generic Operating System Services

* os — Miscellaneous operating system interfaces::
* io — Core tools for working with streams::
* time — Time access and conversions::
* logging — Logging facility for Python::
* logging.config — Logging configuration: logging config — Logging configuration.
* logging.handlers — Logging handlers: logging handlers — Logging handlers.
* platform — Access to underlying platform’s identifying data::
* errno — Standard errno system symbols::
* ctypes — A foreign function library for Python::

os — Miscellaneous operating system interfaces

* File Names, Command Line Arguments, and Environment Variables: File Names Command Line Arguments and Environment Variables.
* Python UTF-8 Mode::
* Process Parameters::
* File Object Creation::
* File Descriptor Operations::
* Files and Directories::
* Process Management::
* Interface to the scheduler::
* Miscellaneous System Information::
* Random numbers: Random numbers<2>.

File Descriptor Operations

* Querying the size of a terminal::
* Inheritance of File Descriptors::

Files and Directories

* Timer File Descriptors::
* Linux extended attributes::

io — Core tools for working with streams

* Overview: Overview<2>.
* Text Encoding::
* High-level Module Interface::
* Class hierarchy::
* Static Typing::
* Performance: Performance<3>.

Overview

* Text I/O::
* Binary I/O::
* Raw I/O::

Text Encoding

* Opt-in EncodingWarning::

Class hierarchy

* I/O Base Classes::
* Raw File I/O::
* Buffered Streams::
* Text I/O: Text I/O<2>.

Performance

* Binary I/O: Binary I/O<2>.
* Text I/O: Text I/O<3>.
* Multi-threading: Multi-threading<3>.
* Reentrancy::

time — Time access and conversions

* Functions: Functions<4>.
* Clock ID Constants::
* Timezone Constants::

logging — Logging facility for Python

* Logger Objects::
* Logging Levels::
* Handler Objects::
* Formatter Objects::
* Filter Objects::
* LogRecord Objects::
* LogRecord attributes::
* LoggerAdapter Objects::
* Thread Safety::
* Module-Level Functions::
* Module-Level Attributes::
* Integration with the warnings module::

logging.config — Logging configuration

* Configuration functions::
* Security considerations::
* Configuration dictionary schema::
* Configuration file format::

Configuration dictionary schema

* Dictionary Schema Details::
* Incremental Configuration::
* Object connections::
* User-defined objects::
* Handler configuration order::
* Access to external objects::
* Access to internal objects::
* Import resolution and custom importers::
* Configuring QueueHandler and QueueListener::

logging.handlers — Logging handlers

* StreamHandler::
* FileHandler::
* NullHandler::
* WatchedFileHandler::
* BaseRotatingHandler::
* RotatingFileHandler::
* TimedRotatingFileHandler::
* SocketHandler::
* DatagramHandler::
* SysLogHandler::
* NTEventLogHandler::
* SMTPHandler::
* MemoryHandler::
* HTTPHandler::
* QueueHandler::
* QueueListener::

platform —  Access to underlying platform’s identifying data

* Cross platform::
* Java platform::
* Windows platform::
* macOS platform::
* iOS platform::
* Unix platforms::
* Linux platforms::
* Android platform::
* Command-line usage: Command-line usage<3>.

ctypes — A foreign function library for Python

* ctypes tutorial::
* ctypes reference::

ctypes tutorial

* Loading dynamic link libraries::
* Accessing functions from loaded dlls::
* Calling functions::
* Fundamental data types::
* Calling functions, continued: Calling functions continued.
* Calling variadic functions::
* Calling functions with your own custom data types::
* Specifying the required argument types (function prototypes): Specifying the required argument types function prototypes.
* Return types::
* Passing pointers (or; passing parameters by reference): Passing pointers or passing parameters by reference.
* Structures and unions::
* Structure/union layout, alignment and byte order: Structure/union layout alignment and byte order.
* Bit fields in structures and unions::
* Arrays::
* Pointers::
* Thread safety without the GIL::
* Type conversions::
* Incomplete Types::
* Callback functions::
* Accessing values exported from dlls::
* Surprises::
* Variable-sized data types::

ctypes reference

* Finding shared libraries::
* Listing loaded shared libraries::
* Loading shared libraries::
* Foreign functions::
* Function prototypes::
* Utility functions::
* Data types::
* Fundamental data types: Fundamental data types<2>.
* Structured data types::
* Arrays and pointers::
* Exceptions: Exceptions<9>.

Command-line interface libraries

* argparse — Parser for command-line options, arguments and subcommands: argparse — Parser for command-line options arguments and subcommands.
* optparse — Parser for command line options::
* getpass — Portable password input::
* fileinput — Iterate over lines from multiple input streams::
* curses — Terminal handling for character-cell displays::
* curses.textpad — Text input widget for curses programs: curses textpad — Text input widget for curses programs.
* curses.ascii — Utilities for ASCII characters: curses ascii — Utilities for ASCII characters.
* curses.panel — A panel stack extension for curses: curses panel — A panel stack extension for curses.
* cmd — Support for line-oriented command interpreters::

argparse — Parser for command-line options, arguments and subcommands

* ArgumentParser objects::
* The add_argument() method: The add_argument method.
* The parse_args() method: The parse_args method.
* Other utilities::
* Exceptions: Exceptions<10>.

ArgumentParser objects

* prog::
* usage::
* description::
* epilog::
* parents::
* formatter_class::
* prefix_chars::
* fromfile_prefix_chars::
* argument_default::
* allow_abbrev::
* conflict_handler::
* add_help::
* exit_on_error::
* suggest_on_error::
* color::

The add_argument() method

* name or flags::
* action::
* nargs::
* const::
* default::
* type::
* choices::
* required::
* help::
* metavar::
* dest::
* deprecated::
* Action classes::

The parse_args() method

* Option value syntax::
* Invalid arguments::
* Arguments containing -::
* Argument abbreviations (prefix matching): Argument abbreviations prefix matching.
* Beyond sys.argv: Beyond sys argv.
* The Namespace object::

Other utilities

* Subcommands::
* FileType objects::
* Argument groups::
* Mutual exclusion::
* Parser defaults::
* Printing help::
* Partial parsing::
* Customizing file parsing::
* Exiting methods::
* Intermixed parsing::
* Registering custom types or actions::

Exceptions

* Argparse Tutorial::
* Migrating optparse code to argparse::

Argparse Tutorial

* Concepts::
* The basics::
* Introducing Positional arguments::
* Introducing Optional arguments::
* Combining Positional and Optional arguments::
* Getting a little more advanced::
* How to translate the argparse output::
* Custom type converters::
* Conclusion::

Introducing Optional arguments

* Short options::

Getting a little more advanced

* Specifying ambiguous arguments::
* Conflicting options::

optparse — Parser for command line options

* Choosing an argument parsing library::
* Introduction: Introduction<6>.
* Background::
* Tutorial: Tutorial<2>.
* Reference Guide::
* Option Callbacks::
* Extending optparse::
* Exceptions: Exceptions<11>.

Background

* Terminology::
* What are options for?::
* What are positional arguments for?::

Tutorial

* Understanding option actions::
* The store action::
* Handling boolean (flag) options: Handling boolean flag options.
* Other actions::
* Default values::
* Generating help::
* Printing a version string::
* How optparse handles errors::
* Putting it all together::

Generating help

* Grouping Options::

Reference Guide

* Creating the parser::
* Populating the parser::
* Defining options::
* Option attributes::
* Standard option actions::
* Standard option types::
* Parsing arguments::
* Querying and manipulating your option parser::
* Conflicts between options::
* Cleanup::
* Other methods::

Option Callbacks

* Defining a callback option::
* How callbacks are called::
* Raising errors in a callback::
* Callback example 1; trivial callback: Callback example 1 trivial callback.
* Callback example 2; check option order: Callback example 2 check option order.
* Callback example 3; check option order (generalized): Callback example 3 check option order generalized.
* Callback example 4; check arbitrary condition: Callback example 4 check arbitrary condition.
* Callback example 5; fixed arguments: Callback example 5 fixed arguments.
* Callback example 6; variable arguments: Callback example 6 variable arguments.

Extending optparse

* Adding new types::
* Adding new actions::

curses — Terminal handling for character-cell displays

* Functions: Functions<5>.
* Window Objects::
* Constants: Constants<6>.

curses.textpad — Text input widget for curses programs

* Textbox objects::

curses.panel — A panel stack extension for curses

* Functions: Functions<6>.
* Panel Objects::

cmd — Support for line-oriented command interpreters

* Cmd Objects::
* Cmd Example::

Concurrent Execution

* threading — Thread-based parallelism::
* multiprocessing — Process-based parallelism::
* multiprocessing.shared_memory — Shared memory for direct access across processes: multiprocessing shared_memory — Shared memory for direct access across processes.
* The concurrent package::
* concurrent.futures — Launching parallel tasks: concurrent futures — Launching parallel tasks.
* concurrent.interpreters — Multiple interpreters in the same process: concurrent interpreters — Multiple interpreters in the same process.
* subprocess — Subprocess management::
* sched — Event scheduler::
* queue — A synchronized queue class::
* contextvars — Context Variables::
* _thread — Low-level threading API::

threading — Thread-based parallelism

* Introduction: Introduction<7>.
* GIL and performance considerations::
* Reference: Reference<2>.
* Using locks, conditions, and semaphores in the with statement: Using locks conditions and semaphores in the with statement.

Reference

* Thread-local data::
* Thread objects::
* Lock objects::
* RLock objects::
* Condition objects::
* Semaphore objects::
* Semaphore example::
* Event objects::
* Timer objects::
* Barrier objects::

multiprocessing — Process-based parallelism

* Introduction: Introduction<8>.
* Reference: Reference<3>.
* Programming guidelines::
* Examples: Examples<15>.

Introduction

* The Process class::
* Contexts and start methods::
* Exchanging objects between processes::
* Synchronization between processes::
* Sharing state between processes::
* Using a pool of workers::

Reference

* Global start method::
* Process and exceptions::
* Pipes and Queues::
* Miscellaneous: Miscellaneous<4>.
* Connection Objects::
* Synchronization primitives::
* Shared ctypes Objects::
* Managers::
* Proxy Objects::
* Process Pools::
* Listeners and Clients::
* Authentication keys::
* Logging: Logging<2>.
* The multiprocessing.dummy module: The multiprocessing dummy module.

Shared ctypes Objects

* The multiprocessing.sharedctypes module: The multiprocessing sharedctypes module.

Managers

* Customized managers::
* Using a remote manager::

Proxy Objects

* Cleanup: Cleanup<2>.

Listeners and Clients

* Address Formats::

Programming guidelines

* All start methods::
* The spawn and forkserver start methods::

concurrent.futures — Launching parallel tasks

* Executor Objects::
* ThreadPoolExecutor::
* InterpreterPoolExecutor::
* ProcessPoolExecutor::
* Future Objects::
* Module Functions::
* Exception classes::

ThreadPoolExecutor

* ThreadPoolExecutor Example::

ProcessPoolExecutor

* ProcessPoolExecutor Example::

concurrent.interpreters — Multiple interpreters in the same process

* Key details::
* Introduction: Introduction<9>.
* Reference: Reference<4>.
* Basic usage::

Introduction

* Multiple Interpreters and Isolation::
* Running in an Interpreter::
* Concurrency and Parallelism::
* Communication Between Interpreters::
* «Sharing» Objects::

Reference

* Interpreter objects::
* Exceptions: Exceptions<12>.
* Communicating Between Interpreters::

subprocess — Subprocess management

* Using the subprocess Module::
* Security Considerations::
* Popen Objects::
* Windows Popen Helpers::
* Older high-level API::
* Replacing Older Functions with the subprocess Module::
* Legacy Shell Invocation Functions::
* Notes: Notes<2>.

Using the subprocess Module

* Frequently Used Arguments::
* Popen Constructor::
* Exceptions: Exceptions<13>.

Windows Popen Helpers

* Windows Constants::

Replacing Older Functions with the subprocess Module

* Replacing /bin/sh shell command substitution::
* Replacing shell pipeline::
* Replacing os.system(): Replacing os system.
* Replacing the os.spawn family: Replacing the os spawn family.
* Replacing os.popen(): Replacing os popen.

Notes

* Timeout Behavior::
* Converting an argument sequence to a string on Windows::
* Disable use of posix_spawn(): Disable use of posix_spawn.

sched — Event scheduler

* Scheduler Objects::

queue — A synchronized queue class

* Queue Objects::
* SimpleQueue Objects::

Queue Objects

* Waiting for task completion::
* Terminating queues::

contextvars — Context Variables

* Context Variables::
* Manual Context Management::
* asyncio support::

Networking and Interprocess Communication

* asyncio — Asynchronous I/O::
* socket — Low-level networking interface::
* ssl — TLS/SSL wrapper for socket objects::
* select — Waiting for I/O completion::
* selectors — High-level I/O multiplexing::
* signal — Set handlers for asynchronous events::
* mmap — Memory-mapped file support::

asyncio — Asynchronous I/O

* Runners::
* Coroutines and Tasks::
* Streams::
* Synchronization Primitives::
* Subprocesses::
* Queues::
* Exceptions: Exceptions<15>.
* Call Graph Introspection::
* Event Loop::
* Futures::
* Transports and Protocols::
* Policies::
* Platform Support::
* Extending::
* High-level API Index::
* Low-level API Index::
* Developing with asyncio::

Runners

* Running an asyncio Program::
* Runner context manager::
* Handling Keyboard Interruption::

Coroutines and Tasks

* Coroutines: Coroutines<3>.
* Awaitables::
* Creating Tasks::
* Task Cancellation::
* Task Groups::
* Sleeping::
* Running Tasks Concurrently::
* Eager Task Factory::
* Shielding From Cancellation::
* Timeouts::
* Waiting Primitives::
* Running in Threads::
* Scheduling From Other Threads::
* Introspection::
* Task Object::

Task Groups

* Terminating a Task Group::

Streams

* StreamReader::
* StreamWriter::
* Examples: Examples<16>.

Examples

* TCP echo client using streams::
* TCP echo server using streams::
* Get HTTP headers::
* Register an open socket to wait for data using streams::

Synchronization Primitives

* Lock::
* Event::
* Condition::
* Semaphore::
* BoundedSemaphore::
* Barrier::

Subprocesses

* Creating Subprocesses::
* Constants: Constants<7>.
* Interacting with Subprocesses::

Interacting with Subprocesses

* Subprocess and Threads::
* Examples: Examples<17>.

Queues

* Queue::
* Priority Queue::
* LIFO Queue::
* Exceptions: Exceptions<14>.
* Examples: Examples<18>.

Call Graph Introspection

* Low level utility functions::

Event Loop

* Event Loop Methods::
* Callback Handles::
* Server Objects::
* Event Loop Implementations::
* Examples: Examples<19>.

Event Loop Methods

* Running and stopping the loop::
* Scheduling callbacks::
* Scheduling delayed callbacks::
* Creating Futures and Tasks::
* Opening network connections::
* Creating network servers::
* Transferring files::
* TLS Upgrade::
* Watching file descriptors::
* Working with socket objects directly::
* DNS::
* Working with pipes::
* Unix signals::
* Executing code in thread or process pools::
* Error Handling API::
* Enabling debug mode::
* Running Subprocesses::

Examples

* Hello World with call_soon(): Hello World with call_soon.
* Display the current date with call_later(): Display the current date with call_later.
* Watch a file descriptor for read events::
* Set signal handlers for SIGINT and SIGTERM::

Futures

* Future Functions::
* Future Object::

Transports and Protocols

* Transports::
* Protocols: Protocols<2>.
* Examples: Examples<20>.

Transports

* Transports Hierarchy::
* Base Transport::
* Read-only Transports::
* Write-only Transports::
* Datagram Transports::
* Subprocess Transports::

Protocols

* Base Protocols::
* Base Protocol::
* Streaming Protocols::
* Buffered Streaming Protocols::
* Datagram Protocols::
* Subprocess Protocols::

Examples

* TCP Echo Server::
* TCP Echo Client::
* UDP Echo Server::
* UDP Echo Client::
* Connecting Existing Sockets::
* loop.subprocess_exec() and SubprocessProtocol: loop subprocess_exec and SubprocessProtocol.

Policies

* Getting and Setting the Policy::
* Policy Objects::
* Custom Policies::

Platform Support

* All Platforms::
* Windows: Windows<83>.
* macOS: macOS<51>.

Windows

* Subprocess Support on Windows::

Extending

* Writing a Custom Event Loop::
* Future and Task private constructors::
* Task lifetime support::

High-level API Index

* Tasks::
* Queues: Queues<2>.
* Subprocesses: Subprocesses<2>.
* Streams: Streams<2>.
* Synchronization::
* Exceptions: Exceptions<16>.

Low-level API Index

* Obtaining the Event Loop::
* Event Loop Methods: Event Loop Methods<2>.
* Transports: Transports<2>.
* Protocols: Protocols<3>.
* Event Loop Policies::

Developing with asyncio

* Debug Mode::
* Concurrency and Multithreading::
* Running Blocking Code::
* Logging: Logging<3>.
* Detect never-awaited coroutines::
* Detect never-retrieved exceptions::

socket — Low-level networking interface

* Socket families::
* Module contents::
* Socket Objects::
* Notes on socket timeouts::
* Example: Example<7>.

Module contents

* Exceptions: Exceptions<17>.
* Constants: Constants<8>.
* Functions: Functions<7>.

Functions

* Creating sockets::
* Other functions: Other functions<2>.

Notes on socket timeouts

* Timeouts and the connect method::
* Timeouts and the accept method::

ssl — TLS/SSL wrapper for socket objects

* Functions, Constants, and Exceptions: Functions Constants and Exceptions.
* SSL Sockets::
* SSL Contexts::
* Certificates::
* Examples: Examples<21>.
* Notes on non-blocking sockets::
* Memory BIO Support: Memory BIO Support<2>.
* SSL session::
* Security considerations: Security considerations<2>.
* TLS 1.3: TLS 1 3.

Functions, Constants, and Exceptions

* Socket creation::
* Context creation::
* Exceptions: Exceptions<18>.
* Random generation::
* Certificate handling::
* Constants: Constants<9>.

Certificates

* Certificate chains::
* CA certificates::
* Combined key and certificate::
* Self-signed certificates::

Examples

* Testing for SSL support::
* Client-side operation::
* Server-side operation::

Security considerations

* Best defaults::
* Manual settings::
* Multi-processing::

Manual settings

* Verifying certificates::
* Protocol versions::
* Cipher selection::

select — Waiting for I/O completion

* /dev/poll Polling Objects::
* Edge and Level Trigger Polling (epoll) Objects: Edge and Level Trigger Polling epoll Objects.
* Polling Objects::
* Kqueue Objects::
* Kevent Objects::

selectors — High-level I/O multiplexing

* Introduction: Introduction<10>.
* Classes: Classes<3>.
* Examples: Examples<22>.

signal — Set handlers for asynchronous events

* General rules::
* Module contents: Module contents<2>.
* Examples: Examples<23>.
* Note on SIGPIPE::
* Note on Signal Handlers and Exceptions::

General rules

* Execution of Python signal handlers::
* Signals and threads::

mmap — Memory-mapped file support

* MADV_* Constants::
* MAP_* Constants::

Internet Data Handling

* email — An email and MIME handling package::
* json — JSON encoder and decoder::
* mailbox — Manipulate mailboxes in various formats::
* mimetypes — Map filenames to MIME types::
* base64 — Base16, Base32, Base64, Base85 Data Encodings: base64 — Base16 Base32 Base64 Base85 Data Encodings.
* binascii — Convert between binary and ASCII::
* quopri — Encode and decode MIME quoted-printable data::

email — An email and MIME handling package

* email.message; Representing an email message: email message Representing an email message.
* email.parser; Parsing email messages: email parser Parsing email messages.
* email.generator; Generating MIME documents: email generator Generating MIME documents.
* email.policy; Policy Objects: email policy Policy Objects.
* email.errors; Exception and Defect classes: email errors Exception and Defect classes.
* email.headerregistry; Custom Header Objects: email headerregistry Custom Header Objects.
* email.contentmanager; Managing MIME Content: email contentmanager Managing MIME Content.
* email; Examples: email Examples.
* email.message.Message; Representing an email message using the compat32 API: email message Message Representing an email message using the compat32 API.
* email.mime; Creating email and MIME objects from scratch: email mime Creating email and MIME objects from scratch.
* email.header; Internationalized headers: email header Internationalized headers.
* email.charset; Representing character sets: email charset Representing character sets.
* email.encoders; Encoders: email encoders Encoders.
* email.utils; Miscellaneous utilities: email utils Miscellaneous utilities.
* email.iterators; Iterators: email iterators Iterators.

email.parser: Parsing email messages

* FeedParser API::
* Parser API::
* Additional notes::

email.contentmanager: Managing MIME Content

* Content Manager Instances::

json — JSON encoder and decoder

* Basic Usage::
* Encoders and Decoders::
* Exceptions: Exceptions<19>.
* Standard Compliance and Interoperability::
* Command-line interface: Command-line interface<5>.

Standard Compliance and Interoperability

* Character Encodings::
* Infinite and NaN Number Values::
* Repeated Names Within an Object::
* Top-level Non-Object, Non-Array Values: Top-level Non-Object Non-Array Values.
* Implementation Limitations::

Command-line interface

* Command-line options: Command-line options<4>.

mailbox — Manipulate mailboxes in various formats

* Mailbox objects::
* Message objects::
* Exceptions: Exceptions<20>.
* Examples: Examples<24>.

Mailbox objects

* Maildir objects::
* mbox objects::
* MH objects::
* Babyl objects::
* MMDF objects::

Message objects

* MaildirMessage objects::
* mboxMessage objects::
* MHMessage objects::
* BabylMessage objects::
* MMDFMessage objects::

mimetypes — Map filenames to MIME types

* MimeTypes objects::
* Command-line usage: Command-line usage<4>.
* Command-line example: Command-line example<2>.

base64 — Base16, Base32, Base64, Base85 Data Encodings

* RFC 4648 Encodings::
* Base85 Encodings::
* Legacy Interface::
* Security Considerations: Security Considerations<2>.

Structured Markup Processing Tools

* html — HyperText Markup Language support::
* html.parser — Simple HTML and XHTML parser: html parser — Simple HTML and XHTML parser.
* html.entities — Definitions of HTML general entities: html entities — Definitions of HTML general entities.
* XML Processing Modules::
* xml.etree.ElementTree — The ElementTree XML API: xml etree ElementTree — The ElementTree XML API.
* xml.dom — The Document Object Model API: xml dom — The Document Object Model API.
* xml.dom.minidom — Minimal DOM implementation: xml dom minidom — Minimal DOM implementation.
* xml.dom.pulldom — Support for building partial DOM trees: xml dom pulldom — Support for building partial DOM trees.
* xml.sax — Support for SAX2 parsers: xml sax — Support for SAX2 parsers.
* xml.sax.handler — Base classes for SAX handlers: xml sax handler — Base classes for SAX handlers.
* xml.sax.saxutils — SAX Utilities: xml sax saxutils — SAX Utilities.
* xml.sax.xmlreader — Interface for XML parsers: xml sax xmlreader — Interface for XML parsers.
* xml.parsers.expat — Fast XML parsing using Expat: xml parsers expat — Fast XML parsing using Expat.

html.parser — Simple HTML and XHTML parser

* Example HTML Parser Application::
* HTMLParser Methods::
* Examples: Examples<25>.

XML Processing Modules

* XML security::

xml.etree.ElementTree — The ElementTree XML API

* Tutorial: Tutorial<3>.
* XPath support::
* Reference: Reference<5>.
* XInclude support::
* Reference: Reference<6>.

Tutorial

* XML tree and elements::
* Parsing XML::
* Pull API for non-blocking parsing::
* Finding interesting elements::
* Modifying an XML File::
* Building XML documents::
* Parsing XML with Namespaces::

XPath support

* Example: Example<8>.
* Supported XPath syntax::

Reference

* Functions: Functions<8>.

XInclude support

* Example: Example<9>.

Reference

* Functions: Functions<9>.
* Element Objects::
* ElementTree Objects::
* QName Objects::
* TreeBuilder Objects::
* XMLParser Objects::
* XMLPullParser Objects::
* Exceptions: Exceptions<21>.

xml.dom — The Document Object Model API

* Module Contents: Module Contents<4>.
* Objects in the DOM::
* Conformance::

Objects in the DOM

* DOMImplementation Objects::
* Node Objects::
* NodeList Objects::
* DocumentType Objects::
* Document Objects::
* Element Objects: Element Objects<2>.
* Attr Objects::
* NamedNodeMap Objects::
* Comment Objects::
* Text and CDATASection Objects::
* ProcessingInstruction Objects::
* Exceptions: Exceptions<22>.

Conformance

* Type Mapping::
* Accessor Methods::

xml.dom.minidom — Minimal DOM implementation

* DOM Objects::
* DOM Example::
* minidom and the DOM standard::

xml.dom.pulldom — Support for building partial DOM trees

* DOMEventStream Objects::

xml.sax — Support for SAX2 parsers

* SAXException Objects::

xml.sax.handler — Base classes for SAX handlers

* ContentHandler Objects::
* DTDHandler Objects::
* EntityResolver Objects::
* ErrorHandler Objects::
* LexicalHandler Objects::

xml.sax.xmlreader — Interface for XML parsers

* XMLReader Objects::
* IncrementalParser Objects::
* Locator Objects::
* InputSource Objects::
* The Attributes Interface::
* The AttributesNS Interface::

xml.parsers.expat — Fast XML parsing using Expat

* XMLParser Objects: XMLParser Objects<2>.
* ExpatError Exceptions::
* Example: Example<10>.
* Content Model Descriptions::
* Expat error constants::

Internet Protocols and Support

* webbrowser — Convenient web-browser controller::
* wsgiref — WSGI Utilities and Reference Implementation::
* urllib — URL handling modules::
* urllib.request — Extensible library for opening URLs: urllib request — Extensible library for opening URLs.
* urllib.response — Response classes used by urllib: urllib response — Response classes used by urllib.
* urllib.parse — Parse URLs into components: urllib parse — Parse URLs into components.
* urllib.error — Exception classes raised by urllib.request: urllib error — Exception classes raised by urllib request.
* urllib.robotparser — Parser for robots.txt: urllib robotparser — Parser for robots txt.
* http — HTTP modules::
* http.client — HTTP protocol client: http client — HTTP protocol client.
* ftplib — FTP protocol client::
* poplib — POP3 protocol client::
* imaplib — IMAP4 protocol client::
* smtplib — SMTP protocol client::
* uuid — UUID objects according to RFC 9562::
* socketserver — A framework for network servers::
* http.server — HTTP servers: http server — HTTP servers.
* http.cookies — HTTP state management: http cookies — HTTP state management.
* http.cookiejar — Cookie handling for HTTP clients: http cookiejar — Cookie handling for HTTP clients.
* xmlrpc — XMLRPC server and client modules::
* xmlrpc.client — XML-RPC client access: xmlrpc client — XML-RPC client access.
* xmlrpc.server — Basic XML-RPC servers: xmlrpc server — Basic XML-RPC servers.
* ipaddress — IPv4/IPv6 manipulation library::

webbrowser — Convenient web-browser controller

* Command-line interface: Command-line interface<6>.
* Browser controller objects::

wsgiref — WSGI Utilities and Reference Implementation

* wsgiref.util – WSGI environment utilities: wsgiref util – WSGI environment utilities.
* wsgiref.headers – WSGI response header tools: wsgiref headers – WSGI response header tools.
* wsgiref.simple_server – a simple WSGI HTTP server: wsgiref simple_server – a simple WSGI HTTP server.
* wsgiref.validate — WSGI conformance checker: wsgiref validate — WSGI conformance checker.
* wsgiref.handlers – server/gateway base classes: wsgiref handlers – server/gateway base classes.
* wsgiref.types – WSGI types for static type checking: wsgiref types – WSGI types for static type checking.
* Examples: Examples<26>.

urllib.request — Extensible library for opening URLs

* Request Objects::
* OpenerDirector Objects::
* BaseHandler Objects::
* HTTPRedirectHandler Objects::
* HTTPCookieProcessor Objects::
* ProxyHandler Objects::
* HTTPPasswordMgr Objects::
* HTTPPasswordMgrWithPriorAuth Objects::
* AbstractBasicAuthHandler Objects::
* HTTPBasicAuthHandler Objects::
* ProxyBasicAuthHandler Objects::
* AbstractDigestAuthHandler Objects::
* HTTPDigestAuthHandler Objects::
* ProxyDigestAuthHandler Objects::
* HTTPHandler Objects::
* HTTPSHandler Objects::
* FileHandler Objects::
* DataHandler Objects::
* FTPHandler Objects::
* CacheFTPHandler Objects::
* UnknownHandler Objects::
* HTTPErrorProcessor Objects::
* Examples: Examples<27>.
* Legacy interface::
* urllib.request Restrictions: urllib request Restrictions.

urllib.parse — Parse URLs into components

* URL Parsing::
* URL parsing security::
* Parsing ASCII Encoded Bytes::
* Structured Parse Results::
* URL Quoting::

http — HTTP modules

* HTTP status codes::
* HTTP status category::
* HTTP methods::

http.client — HTTP protocol client

* HTTPConnection Objects::
* HTTPResponse Objects::
* Examples: Examples<28>.
* HTTPMessage Objects::

ftplib — FTP protocol client

* Reference: Reference<7>.

Reference

* FTP objects::
* FTP_TLS objects::
* Module variables::

poplib — POP3 protocol client

* POP3 Objects::
* POP3 Example::

imaplib — IMAP4 protocol client

* IMAP4 Objects::
* IMAP4 Example::

smtplib — SMTP protocol client

* SMTP Objects::
* SMTP Example::

uuid — UUID objects according to RFC 9562

* Command-Line Usage::
* Example: Example<11>.
* Command-Line Example::

socketserver — A framework for network servers

* Server Creation Notes::
* Server Objects: Server Objects<2>.
* Request Handler Objects::
* Examples: Examples<29>.

Examples

* socketserver.TCPServer Example: socketserver TCPServer Example.
* socketserver.UDPServer Example: socketserver UDPServer Example.
* Asynchronous Mixins::

http.server — HTTP servers

* Command-line interface: Command-line interface<7>.
* Security considerations: Security considerations<3>.

http.cookies — HTTP state management

* Cookie Objects::
* Morsel Objects::
* Example: Example<12>.

http.cookiejar — Cookie handling for HTTP clients

* CookieJar and FileCookieJar Objects::
* FileCookieJar subclasses and co-operation with web browsers::
* CookiePolicy Objects::
* DefaultCookiePolicy Objects::
* Cookie Objects: Cookie Objects<2>.
* Examples: Examples<30>.

xmlrpc.client — XML-RPC client access

* ServerProxy Objects::
* DateTime Objects::
* Binary Objects::
* Fault Objects::
* ProtocolError Objects::
* MultiCall Objects::
* Convenience Functions::
* Example of Client Usage::
* Example of Client and Server Usage::

xmlrpc.server — Basic XML-RPC servers

* SimpleXMLRPCServer Objects::
* CGIXMLRPCRequestHandler::
* Documenting XMLRPC server::
* DocXMLRPCServer Objects::
* DocCGIXMLRPCRequestHandler::

SimpleXMLRPCServer Objects

* SimpleXMLRPCServer Example::

ipaddress — IPv4/IPv6 manipulation library

* Convenience factory functions::
* IP Addresses::
* IP Network definitions::
* Interface objects::
* Other Module Level Functions::
* Custom Exceptions::

IP Addresses

* Address objects::
* Conversion to Strings and Integers::
* Operators: Operators<2>.

Operators

* Comparison operators::
* Arithmetic operators::

IP Network definitions

* Prefix, net mask and host mask: Prefix net mask and host mask.
* Network objects::
* Operators: Operators<3>.

Operators

* Logical operators::
* Iteration::
* Networks as containers of addresses::

Interface objects

* Operators: Operators<4>.

Operators

* Logical operators: Logical operators<2>.

Multimedia Services

* wave — Read and write WAV files::
* colorsys — Conversions between color systems::

wave — Read and write WAV files

* Wave_read Objects::
* Wave_write Objects::

Internationalization

* gettext — Multilingual internationalization services::
* locale — Internationalization services::

gettext — Multilingual internationalization services

* GNU gettext API::
* Class-based API::
* Internationalizing your programs and modules::
* Acknowledgements: Acknowledgements<9>.

Class-based API

* The NullTranslations class::
* The GNUTranslations class::
* Solaris message catalog support::
* The Catalog constructor::

Internationalizing your programs and modules

* Localizing your module::
* Localizing your application::
* Changing languages on the fly::
* Deferred translations::

locale — Internationalization services

* Background, details, hints, tips and caveats: Background details hints tips and caveats.
* Locale names::
* For extension writers and programs that embed Python::
* Access to message catalogs::

Graphical user interfaces with Tk

* tkinter — Python interface to Tcl/Tk::
* tkinter.colorchooser — Color choosing dialog: tkinter colorchooser — Color choosing dialog.
* tkinter.font — Tkinter font wrapper: tkinter font — Tkinter font wrapper.
* Tkinter Dialogs::
* tkinter.messagebox — Tkinter message prompts: tkinter messagebox — Tkinter message prompts.
* tkinter.scrolledtext — Scrolled Text Widget: tkinter scrolledtext — Scrolled Text Widget.
* tkinter.dnd — Drag and drop support: tkinter dnd — Drag and drop support.
* tkinter.ttk — Tk themed widgets: tkinter ttk — Tk themed widgets.
* IDLE — Python editor and shell: IDLE — Python editor and shell<2>.
* turtle — Turtle graphics::

tkinter — Python interface to Tcl/Tk

* Architecture::
* Tkinter Modules::
* Tkinter Life Preserver::
* Threading model::
* Handy Reference::
* File Handlers::

Tkinter Life Preserver

* A Hello World Program::
* Important Tk Concepts::
* Understanding How Tkinter Wraps Tcl/Tk::
* How do I…? What option does…?::
* Navigating the Tcl/Tk Reference Manual::

Handy Reference

* Setting Options::
* The Packer::
* Packer Options::
* Coupling Widget Variables::
* The Window Manager::
* Tk Option Data Types::
* Bindings and Events::
* The index Parameter::
* Images::

Tkinter Dialogs

* tkinter.simpledialog — Standard Tkinter input dialogs: tkinter simpledialog — Standard Tkinter input dialogs.
* tkinter.filedialog — File selection dialogs: tkinter filedialog — File selection dialogs.
* tkinter.commondialog — Dialog window templates: tkinter commondialog — Dialog window templates.

tkinter.filedialog — File selection dialogs

* Native Load/Save Dialogs::

tkinter.ttk — Tk themed widgets

* Using Ttk::
* Ttk Widgets::
* Widget::
* Combobox::
* Spinbox::
* Notebook::
* Progressbar::
* Separator::
* Sizegrip::
* Treeview::
* Ttk Styling::

Widget

* Standard Options::
* Scrollable Widget Options::
* Label Options::
* Compatibility Options::
* Widget States::
* ttk.Widget: ttk Widget.

Combobox

* Options::
* Virtual events::
* ttk.Combobox: ttk Combobox.

Spinbox

* Options: Options<2>.
* Virtual events: Virtual events<2>.
* ttk.Spinbox: ttk Spinbox.

Notebook

* Options: Options<3>.
* Tab Options::
* Tab Identifiers::
* Virtual Events::
* ttk.Notebook: ttk Notebook.

Progressbar

* Options: Options<4>.
* ttk.Progressbar: ttk Progressbar.

Separator

* Options: Options<5>.

Sizegrip

* Platform-specific notes::
* Bugs::

Treeview

* Options: Options<6>.
* Item Options::
* Tag Options::
* Column Identifiers::
* Virtual Events: Virtual Events<2>.
* ttk.Treeview: ttk Treeview.

Ttk Styling

* Layouts::

IDLE — Python editor and shell

* Menus::
* Editing and Navigation::
* Startup and Code Execution::
* Help and Preferences::
* idlelib — implementation of IDLE application::

Menus

* File menu (Shell and Editor): File menu Shell and Editor.
* Edit menu (Shell and Editor): Edit menu Shell and Editor.
* Format menu (Editor window only): Format menu Editor window only.
* Run menu (Editor window only): Run menu Editor window only.
* Shell menu (Shell window only): Shell menu Shell window only.
* Debug menu (Shell window only): Debug menu Shell window only.
* Options menu (Shell and Editor): Options menu Shell and Editor.
* Window menu (Shell and Editor): Window menu Shell and Editor.
* Help menu (Shell and Editor): Help menu Shell and Editor.
* Context menus::

Editing and Navigation

* Editor windows::
* Key bindings::
* Automatic indentation::
* Search and Replace::
* Completions::
* Calltips::
* Format block::
* Code Context::
* Shell window::
* Text colors::

Startup and Code Execution

* Command-line usage: Command-line usage<5>.
* Startup failure::
* Running user code::
* User output in Shell::
* Developing tkinter applications::
* Running without a subprocess::

Help and Preferences

* Help sources::
* Setting preferences::
* IDLE on macOS::
* Extensions::

turtle — Turtle graphics

* Introduction: Introduction<11>.
* Get started::
* Tutorial: Tutorial<4>.
* How to…::
* Turtle graphics reference::
* Methods of RawTurtle/Turtle and corresponding functions::
* Methods of TurtleScreen/Screen and corresponding functions::
* Public classes::
* Explanation: Explanation<2>.
* Help and configuration::
* turtledemo — Demo scripts::
* Changes since Python 2.6: Changes since Python 2 6.
* Changes since Python 3.0: Changes since Python 3 0.

Tutorial

* Starting a turtle environment::
* Basic drawing::
* Making algorithmic patterns::

Basic drawing

* Pen control::
* The turtle’s position::

How to…

* Get started as quickly as possible::
* Automatically begin and end filling::
* Use the turtle module namespace::
* Use turtle graphics in a script::
* Use object-oriented turtle graphics::

Turtle graphics reference

* Turtle methods::
* Methods of TurtleScreen/Screen::

Methods of RawTurtle/Turtle and corresponding functions

* Turtle motion::
* Tell Turtle’s state::
* Settings for measurement::
* Pen control: Pen control<2>.
* Turtle state::
* Using events::
* Special Turtle methods::
* Compound shapes::

Pen control

* Drawing state::
* Color control::
* Filling::
* More drawing control::

Turtle state

* Visibility::
* Appearance::

Methods of TurtleScreen/Screen and corresponding functions

* Window control::
* Animation control::
* Using screen events::
* Input methods::
* Settings and special methods::
* Methods specific to Screen, not inherited from TurtleScreen: Methods specific to Screen not inherited from TurtleScreen.

Help and configuration

* How to use help::
* Translation of docstrings into different languages::
* How to configure Screen and Turtles::

Development Tools

* typing — Support for type hints::
* pydoc — Documentation generator and online help system::
* Python Development Mode::
* doctest — Test interactive Python examples::
* unittest — Unit testing framework::
* unittest.mock — mock object library: unittest mock — mock object library.
* unittest.mock — getting started: unittest mock — getting started.
* test — Regression tests package for Python::
* test.support — Utilities for the Python test suite: test support — Utilities for the Python test suite.
* test.support.socket_helper — Utilities for socket tests: test support socket_helper — Utilities for socket tests.
* test.support.script_helper — Utilities for the Python execution tests: test support script_helper — Utilities for the Python execution tests.
* test.support.bytecode_helper — Support tools for testing correct bytecode generation: test support bytecode_helper — Support tools for testing correct bytecode generation.
* test.support.threading_helper — Utilities for threading tests: test support threading_helper — Utilities for threading tests.
* test.support.os_helper — Utilities for os tests: test support os_helper — Utilities for os tests.
* test.support.import_helper — Utilities for import tests: test support import_helper — Utilities for import tests.
* test.support.warnings_helper — Utilities for warnings tests: test support warnings_helper — Utilities for warnings tests.

typing — Support for type hints

* Specification for the Python Type System::
* Type aliases::
* NewType::
* Annotating callable objects::
* Generics::
* Annotating tuples::
* The type of class objects::
* Annotating generators and coroutines::
* User-defined generic types::
* The Any type::
* Nominal vs structural subtyping::
* Module contents: Module contents<3>.
* Deprecation Timeline of Major Features::

Module contents

* Special typing primitives::
* Protocols: Protocols<4>.
* ABCs and Protocols for working with I/O::
* Functions and decorators::
* Introspection helpers::
* Constant::
* Deprecated aliases::

Special typing primitives

* Special types::
* Special forms::
* Building generic types and type aliases::
* Other special directives::

Deprecated aliases

* Aliases to built-in types::
* Aliases to types in collections::
* Aliases to other concrete types::
* Aliases to container ABCs in collections.abc: Aliases to container ABCs in collections abc.
* Aliases to asynchronous ABCs in collections.abc: Aliases to asynchronous ABCs in collections abc.
* Aliases to other ABCs in collections.abc: Aliases to other ABCs in collections abc.
* Aliases to contextlib ABCs::

Python Development Mode

* Effects of the Python Development Mode::
* ResourceWarning Example::
* Bad file descriptor error example::

doctest — Test interactive Python examples

* Simple Usage; Checking Examples in Docstrings: Simple Usage Checking Examples in Docstrings.
* Simple Usage; Checking Examples in a Text File: Simple Usage Checking Examples in a Text File.
* Command-line Usage::
* How It Works::
* Basic API::
* Unittest API::
* Advanced API::
* Debugging::
* Soapbox::

How It Works

* Which Docstrings Are Examined?::
* How are Docstring Examples Recognized?::
* What’s the Execution Context?::
* What About Exceptions?::
* Option Flags::
* Directives::
* Warnings: Warnings<2>.

Advanced API

* DocTest Objects::
* Example Objects::
* DocTestFinder objects::
* DocTestParser objects::
* TestResults objects::
* DocTestRunner objects::
* OutputChecker objects::

unittest — Unit testing framework

* Basic example::
* Command-Line Interface: Command-Line Interface<2>.
* Test Discovery::
* Organizing test code::
* Re-using old test code::
* Skipping tests and expected failures::
* Distinguishing test iterations using subtests::
* Classes and functions::
* Class and Module Fixtures::
* Signal Handling::

Command-Line Interface

* Command-line options: Command-line options<5>.

Classes and functions

* Test cases::
* Grouping tests::
* Loading and running tests::

Loading and running tests

* load_tests Protocol::

Class and Module Fixtures

* setUpClass and tearDownClass::
* setUpModule and tearDownModule::

unittest.mock — mock object library

* Quick Guide::
* The Mock Class::
* The patchers::
* MagicMock and magic method support::
* Helpers::
* Order of precedence of side_effect, return_value and wraps: Order of precedence of side_effect return_value and wraps.

The Mock Class

* Calling::
* Deleting Attributes::
* Mock names and the name attribute::
* Attaching Mocks as Attributes::

The patchers

* patch::
* patch.object: patch object.
* patch.dict: patch dict.
* patch.multiple: patch multiple.
* patch methods; start and stop: patch methods start and stop.
* patch builtins::
* TEST_PREFIX::
* Nesting Patch Decorators::
* Where to patch::
* Patching Descriptors and Proxy Objects::

MagicMock and magic method support

* Mocking Magic Methods::
* Magic Mock::

Helpers

* sentinel::
* DEFAULT::
* call::
* create_autospec::
* ANY::
* FILTER_DIR::
* mock_open::
* Autospeccing::
* Sealing mocks::

unittest.mock — getting started

* Using Mock::
* Patch Decorators::
* Further Examples::

Using Mock

* Mock Patching Methods::
* Mock for Method Calls on an Object::
* Mocking Classes::
* Naming your mocks::
* Tracking all Calls::
* Setting Return Values and Attributes::
* Raising exceptions with mocks::
* Side effect functions and iterables::
* Mocking asynchronous iterators::
* Mocking asynchronous context manager::
* Creating a Mock from an Existing Object::
* Using side_effect to return per file content::

Further Examples

* Mocking chained calls::
* Partial mocking::
* Mocking a Generator Method::
* Applying the same patch to every test method::
* Mocking Unbound Methods::
* Checking multiple calls with mock::
* Coping with mutable arguments::
* Nesting Patches::
* Mocking a dictionary with MagicMock::
* Mock subclasses and their attributes::
* Mocking imports with patch.dict: Mocking imports with patch dict.
* Tracking order of calls and less verbose call assertions::
* More complex argument matching::

test — Regression tests package for Python

* Writing Unit Tests for the test package::
* Running tests using the command-line interface::

Debugging and Profiling

* Audit events table::
* bdb — Debugger framework::
* faulthandler — Dump the Python traceback::
* pdb — The Python Debugger::
* The Python Profilers::
* timeit — Measure execution time of small code snippets::
* trace — Trace or track Python statement execution::
* tracemalloc — Trace memory allocations::

faulthandler — Dump the Python traceback

* Dumping the traceback::
* Dumping the C stack::
* Fault handler state::
* Dumping the tracebacks after a timeout::
* Dumping the traceback on a user signal::
* Issue with file descriptors::
* Example: Example<13>.

Dumping the C stack

* C Stack Compatibility::

pdb — The Python Debugger

* Command-line interface: Command-line interface<8>.
* Debugger commands::

The Python Profilers

* Introduction to the profilers::
* Instant User’s Manual::
* profile and cProfile Module Reference::
* The Stats Class::
* What Is Deterministic Profiling?::
* Limitations::
* Calibration::
* Using a custom timer::

timeit — Measure execution time of small code snippets

* Basic Examples: Basic Examples<2>.
* Python Interface::
* Command-Line Interface: Command-Line Interface<3>.
* Examples: Examples<31>.

trace — Trace or track Python statement execution

* Command-Line Usage: Command-Line Usage<2>.
* Programmatic Interface::

Command-Line Usage

* Main options::
* Modifiers::
* Filters::

tracemalloc — Trace memory allocations

* Examples: Examples<32>.
* API::

Examples

* Display the top 10::
* Compute differences::
* Get the traceback of a memory block::
* Pretty top::

Pretty top

* Record the current and peak size of all traced memory blocks::

API

* Functions: Functions<10>.
* DomainFilter::
* Filter::
* Frame::
* Snapshot::
* Statistic::
* StatisticDiff::
* Trace::
* Traceback::

Software Packaging and Distribution

* ensurepip — Bootstrapping the pip installer::
* venv — Creation of virtual environments::
* zipapp — Manage executable Python zip archives::

ensurepip — Bootstrapping the pip installer

* Command-line interface: Command-line interface<9>.
* Module API::

venv — Creation of virtual environments

* Creating virtual environments::
* How venvs work::
* API: API<2>.
* An example of extending EnvBuilder::

zipapp — Manage executable Python zip archives

* Basic Example::
* Command-Line Interface: Command-Line Interface<4>.
* Python API::
* Examples: Examples<33>.
* Specifying the Interpreter::
* Creating Standalone Applications with zipapp::
* The Python Zip Application Archive Format::

Creating Standalone Applications with zipapp

* Caveats::

Python Runtime Services

* sys — System-specific parameters and functions::
* sys.monitoring — Execution event monitoring: sys monitoring — Execution event monitoring.
* sysconfig — Provide access to Python’s configuration information::
* builtins — Built-in objects::
* __main__ — Top-level code environment::
* warnings — Warning control::
* dataclasses — Data Classes::
* contextlib — Utilities for with-statement contexts::
* abc — Abstract Base Classes::
* atexit — Exit handlers::
* traceback — Print or retrieve a stack traceback::
* __future__ — Future statement definitions::
* gc — Garbage Collector interface::
* inspect — Inspect live objects::
* annotationlib — Functionality for introspecting annotations::
* site — Site-specific configuration hook::

sys.monitoring — Execution event monitoring

* Tool identifiers::
* Events::
* Turning events on and off::
* Registering callback functions::

Tool identifiers

* Registering and using tools::

Events

* Local events::
* Deprecated event::
* Ancillary events::
* Other events::
* The STOP_ITERATION event::

Turning events on and off

* Setting events globally::
* Per code object events::
* Disabling events::

Registering callback functions

* Callback function arguments::

sysconfig — Provide access to Python’s configuration information

* Configuration variables::
* Installation paths::
* User scheme::
* Home scheme::
* Prefix scheme::
* Installation path functions::
* Other functions: Other functions<3>.
* Command-line usage: Command-line usage<6>.

User scheme

* posix_user::
* nt_user::
* osx_framework_user::

Home scheme

* posix_home::

Prefix scheme

* posix_prefix::
* nt::

__main__ — Top-level code environment

* __name__ == '__main__'::
* __main__.py in Python Packages: __main__ py in Python Packages.
* import __main__::

__name__ == '__main__'

* What is the «top-level code environment»?::
* Idiomatic Usage::
* Packaging Considerations::

__main__.py in Python Packages

* Idiomatic Usage: Idiomatic Usage<2>.

warnings — Warning control

* Warning Categories::
* The Warnings Filter::
* Temporarily Suppressing Warnings::
* Testing Warnings::
* Updating Code For New Versions of Dependencies::
* Available Functions::
* Available Context Managers::
* Concurrent safety of Context Managers::

The Warnings Filter

* Repeated Warning Suppression Criteria::
* Describing Warning Filters::
* Default Warning Filter::
* Overriding the default filter::

dataclasses — Data Classes

* Module contents: Module contents<4>.
* Post-init processing::
* Class variables::
* Init-only variables::
* Frozen instances::
* Inheritance::
* Re-ordering of keyword-only parameters in __init__(): Re-ordering of keyword-only parameters in __init__.
* Default factory functions::
* Mutable default values::
* Descriptor-typed fields::

contextlib — Utilities for with-statement contexts

* Utilities::
* Examples and Recipes: Examples and Recipes<3>.
* Single use, reusable and reentrant context managers: Single use reusable and reentrant context managers.

Examples and Recipes

* Supporting a variable number of context managers::
* Catching exceptions from __enter__ methods::
* Cleaning up in an __enter__ implementation::
* Replacing any use of try-finally and flag variables::
* Using a context manager as a function decorator::

Single use, reusable and reentrant context managers

* Reentrant context managers::
* Reusable context managers::

atexit — Exit handlers

* atexit Example::

traceback — Print or retrieve a stack traceback

* Module-Level Functions: Module-Level Functions<2>.
* TracebackException Objects::
* StackSummary Objects::
* FrameSummary Objects::
* Examples of Using the Module-Level Functions::
* Examples of Using TracebackException::

__future__ — Future statement definitions

* Module Contents: Module Contents<5>.

inspect — Inspect live objects

* Types and members::
* Retrieving source code::
* Introspecting callables with the Signature object::
* Classes and functions: Classes and functions<2>.
* The interpreter stack::
* Fetching attributes statically::
* Current State of Generators, Coroutines, and Asynchronous Generators: Current State of Generators Coroutines and Asynchronous Generators.
* Code Objects Bit Flags::
* Buffer flags::
* Command-line interface: Command-line interface<10>.

annotationlib — Functionality for introspecting annotations

* Annotation semantics::
* Classes: Classes<4>.
* Functions: Functions<11>.
* Recipes: Recipes<3>.
* Limitations of the STRING format::
* Limitations of the FORWARDREF format::
* Security implications of introspecting annotations::

Recipes

* Using annotations in a metaclass::

site — Site-specific configuration hook

* sitecustomize::
* usercustomize::
* Readline configuration::
* Module contents: Module contents<5>.
* Command-line interface: Command-line interface<11>.

Custom Python Interpreters

* code — Interpreter base classes::
* codeop — Compile Python code::

code — Interpreter base classes

* Interactive Interpreter Objects::
* Interactive Console Objects::

Importing Modules

* zipimport — Import modules from Zip archives::
* pkgutil — Package extension utility::
* modulefinder — Find modules used by a script::
* runpy — Locating and executing Python modules::
* importlib — The implementation of import::
* importlib.resources – Package resource reading, opening and access: importlib resources – Package resource reading opening and access.
* importlib.resources.abc – Abstract base classes for resources: importlib resources abc – Abstract base classes for resources.
* importlib.metadata – Accessing package metadata: importlib metadata – Accessing package metadata.
* The initialization of the sys.path module search path: The initialization of the sys path module search path.

zipimport — Import modules from Zip archives

* zipimporter Objects::
* Examples: Examples<34>.

modulefinder — Find modules used by a script

* Example usage of ModuleFinder::

importlib — The implementation of import

* Introduction: Introduction<12>.
* Functions: Functions<12>.
* importlib.abc – Abstract base classes related to import: importlib abc – Abstract base classes related to import.
* importlib.machinery – Importers and path hooks: importlib machinery – Importers and path hooks.
* importlib.util – Utility code for importers: importlib util – Utility code for importers.
* Examples: Examples<35>.

Examples

* Importing programmatically::
* Checking if a module can be imported::
* Importing a source file directly::
* Implementing lazy imports::
* Setting up an importer::
* Approximating importlib.import_module(): Approximating importlib import_module.

importlib.resources – Package resource reading, opening and access

* Functional API::

importlib.metadata – Accessing package metadata

* Overview: Overview<3>.
* Functional API: Functional API<2>.
* Distributions::
* Distribution Discovery::
* Implementing Custom Providers::

Functional API

* Entry points::
* Distribution metadata::
* Distribution versions::
* Distribution files::
* Distribution requirements::
* Mapping import to distribution packages::

Implementing Custom Providers

* Example: Example<14>.

The initialization of the sys.path module search path

* Virtual Environments::
* _pth files::
* Embedded Python::

Python Language Services

* ast — Abstract syntax trees::
* symtable — Access to the compiler’s symbol tables::
* token — Constants used with Python parse trees::
* keyword — Testing for Python keywords::
* tokenize — Tokenizer for Python source::
* tabnanny — Detection of ambiguous indentation::
* pyclbr — Python module browser support::
* py_compile — Compile Python source files::
* compileall — Byte-compile Python libraries::
* dis — Disassembler for Python bytecode::
* pickletools — Tools for pickle developers::

ast — Abstract syntax trees

* Abstract grammar::
* Node classes::
* ast helpers::
* Compiler flags: Compiler flags<2>.
* Command-line usage: Command-line usage<7>.

Node classes

* Root nodes::
* Literals: Literals<3>.
* Variables::
* Expressions: Expressions<2>.
* Statements::
* Control flow::
* Pattern matching::
* Type annotations::
* Type parameters::
* Function and class definitions::
* Async and await::

Expressions

* Subscripting::
* Comprehensions::

Statements

* Imports::

symtable — Access to the compiler’s symbol tables

* Generating Symbol Tables::
* Examining Symbol Tables::
* Command-Line Usage: Command-Line Usage<3>.

tokenize — Tokenizer for Python source

* Tokenizing Input::
* Command-Line Usage: Command-Line Usage<4>.
* Examples: Examples<36>.

pyclbr — Python module browser support

* Function Objects::
* Class Objects::

py_compile — Compile Python source files

* Command-Line Interface: Command-Line Interface<5>.

compileall — Byte-compile Python libraries

* Command-line use::
* Public functions::

dis — Disassembler for Python bytecode

* Command-line interface: Command-line interface<12>.
* Bytecode analysis::
* Analysis functions::
* Python Bytecode Instructions::
* Opcode collections::

pickletools — Tools for pickle developers

* Command-line usage: Command-line usage<8>.
* Programmatic interface::

Command-line usage

* Command-line options: Command-line options<6>.

MS Windows Specific Services

* msvcrt — Useful routines from the MS VC++ runtime::
* winreg — Windows registry access::
* winsound — Sound-playing interface for Windows::

msvcrt — Useful routines from the MS VC++ runtime

* File Operations::
* Console I/O::
* Other Functions::

winreg — Windows registry access

* Functions: Functions<13>.
* Constants: Constants<10>.
* Registry Handle Objects::

Constants

* HKEY_* Constants::
* Access Rights::
* Value Types::

Access Rights

* 64-bit Specific::

Unix-specific services

* shlex — Simple lexical analysis::
* posix — The most common POSIX system calls::
* pwd — The password database::
* grp — The group database::
* termios — POSIX style tty control::
* tty — Terminal control functions::
* pty — Pseudo-terminal utilities::
* fcntl — The fcntl and ioctl system calls::
* resource — Resource usage information::
* syslog — Unix syslog library routines::

shlex — Simple lexical analysis

* shlex Objects::
* Parsing Rules::
* Improved Compatibility with Shells::

posix — The most common POSIX system calls

* Large File Support::
* Notable Module Contents::

termios — POSIX style tty control

* Example: Example<15>.

pty — Pseudo-terminal utilities

* Example: Example<16>.

resource — Resource usage information

* Resource Limits::
* Resource Usage::

syslog — Unix syslog library routines

* Examples: Examples<37>.

Examples

* Simple example::

Superseded Modules

* getopt — C-style parser for command line options::

Removed Modules

* aifc — Read and write AIFF and AIFC files::
* asynchat — Asynchronous socket command/response handler::
* asyncore — Asynchronous socket handler::
* audioop — Manipulate raw audio data::
* cgi — Common Gateway Interface support::
* cgitb — Traceback manager for CGI scripts::
* chunk — Read IFF chunked data::
* crypt — Function to check Unix passwords::
* distutils — Building and installing Python modules::
* imghdr — Determine the type of an image::
* imp — Access the import internals::
* mailcap — Mailcap file handling::
* msilib — Read and write Microsoft Installer files::
* nis — Interface to Sun’s NIS (Yellow Pages): nis — Interface to Sun’s NIS Yellow Pages.
* nntplib — NNTP protocol client::
* ossaudiodev — Access to OSS-compatible audio devices::
* pipes — Interface to shell pipelines::
* smtpd — SMTP Server::
* sndhdr — Determine type of sound file::
* spwd — The shadow password database::
* sunau — Read and write Sun AU files::
* telnetlib — Telnet client::
* uu — Encode and decode uuencode files::
* xdrlib — Encode and decode XDR data::

Extending and Embedding the Python Interpreter

* Recommended third party tools::
* Creating extensions without third party tools::
* Embedding the CPython runtime in a larger application::

Creating extensions without third party tools

* Extending Python with C or C++::
* Defining Extension Types; Tutorial: Defining Extension Types Tutorial.
* Defining Extension Types; Assorted Topics: Defining Extension Types Assorted Topics.
* Building C and C++ Extensions::
* Building C and C++ Extensions on Windows::

Extending Python with C or C++

* A Simple Example::
* Intermezzo; Errors and Exceptions: Intermezzo Errors and Exceptions.
* Back to the Example::
* The Module’s Method Table and Initialization Function::
* Compilation and Linkage::
* Calling Python Functions from C::
* Extracting Parameters in Extension Functions::
* Keyword Parameters for Extension Functions::
* Building Arbitrary Values::
* Reference Counts::
* Writing Extensions in C++::
* Providing a C API for an Extension Module::

Reference Counts

* Reference Counting in Python::
* Ownership Rules::
* Thin Ice::
* NULL Pointers::

Defining Extension Types: Tutorial

* The Basics::
* Adding data and methods to the Basic example::
* Providing finer control over data attributes::
* Supporting cyclic garbage collection::
* Subclassing other types::

Defining Extension Types: Assorted Topics

* Finalization and De-allocation::
* Object Presentation::
* Attribute Management::
* Object Comparison::
* Abstract Protocol Support::
* Weak Reference Support::
* More Suggestions::

Attribute Management

* Generic Attribute Management::
* Type-specific Attribute Management::

Building C and C++ Extensions

* Building C and C++ Extensions with setuptools::

Building C and C++ Extensions on Windows

* A Cookbook Approach::
* Differences Between Unix and Windows::
* Using DLLs in Practice::

Embedding the CPython runtime in a larger application

* Embedding Python in Another Application::

Embedding Python in Another Application

* Very High Level Embedding::
* Beyond Very High Level Embedding; An overview: Beyond Very High Level Embedding An overview.
* Pure Embedding::
* Extending Embedded Python::
* Embedding Python in C++::
* Compiling and Linking under Unix-like systems::

Python/C API Reference Manual

* Introduction: Introduction<13>.
* C API Stability::
* The Very High Level Layer::
* Reference Counting::
* Exception Handling::
* Defining extension modules::
* Utilities: Utilities<2>.
* Abstract Objects Layer::
* Concrete Objects Layer::
* Initialization, Finalization, and Threads: Initialization Finalization and Threads.
* Python Initialization Configuration::
* Memory Management::
* Object Implementation Support::
* API and ABI Versioning::
* Monitoring C API::
* Generating Execution Events::

Introduction

* Language version compatibility::
* Coding standards::
* Include Files::
* Useful macros::
* Objects, Types and Reference Counts: Objects Types and Reference Counts.
* Exceptions: Exceptions<23>.
* Embedding Python: Embedding Python<2>.
* Debugging Builds::
* Recommended third party tools: Recommended third party tools<2>.

Objects, Types and Reference Counts

* Reference Counts: Reference Counts<2>.
* Types: Types<2>.

Reference Counts

* Reference Count Details::

C API Stability

* Unstable C API::
* Stable Application Binary Interface::
* Platform Considerations::
* Contents of Limited API::

Stable Application Binary Interface

* Limited C API::
* Stable ABI::
* Limited API Scope and Performance::
* Limited API Caveats::

The Very High Level Layer

* Available start symbols::
* Stack Effects::

Exception Handling

* Printing and clearing::
* Raising exceptions::
* Issuing warnings::
* Querying the error indicator::
* Signal Handling: Signal Handling<2>.
* Exception Classes::
* Exception Objects::
* Unicode Exception Objects::
* Recursion Control::
* Exception and warning types::
* Tracebacks::

Exception and warning types

* Exception types::
* OSError aliases::
* Warning types::

Defining extension modules

* Multiple module instances::
* Initialization function::
* Multi-phase initialization::
* Legacy single-phase initialization::

Utilities

* Operating System Utilities::
* System Functions::
* Process Control::
* Importing Modules: Importing Modules<2>.
* Data marshalling support::
* Parsing arguments and building values::
* String conversion and formatting::
* Character classification and conversion::
* PyHash API::
* Reflection::
* Codec registry and support functions::
* PyTime C API::
* Support for Perf Maps::

Parsing arguments and building values

* Parsing arguments: Parsing arguments<2>.
* Building values::

Parsing arguments

* Strings and buffers::
* Numbers::
* Other objects::
* API Functions::

Codec registry and support functions

* Codec lookup API::
* Registry API for Unicode encoding error handlers::
* Codec utility variables::

PyTime C API

* Types: Types<3>.
* Clock Functions::
* Raw Clock Functions::
* Conversion functions::

Abstract Objects Layer

* Object Protocol::
* Call Protocol::
* Number Protocol::
* Sequence Protocol::
* Mapping Protocol::
* Iterator Protocol::
* Buffer Protocol::

Call Protocol

* The tp_call Protocol::
* The Vectorcall Protocol::
* Object Calling API::
* Call Support API::

The Vectorcall Protocol

* Recursion Control: Recursion Control<2>.
* Vectorcall Support API::

Buffer Protocol

* Buffer structure::
* Buffer request types::
* Complex arrays::
* Buffer-related functions::

Buffer request types

* request-independent fields::
* readonly, format: readonly format.
* shape, strides, suboffsets: shape strides suboffsets.
* contiguity requests::
* compound requests::

Complex arrays

* NumPy-style; shape and strides: NumPy-style shape and strides.
* PIL-style; shape, strides and suboffsets: PIL-style shape strides and suboffsets.

Concrete Objects Layer

* Fundamental Objects::
* Numeric Objects::
* Sequence Objects::
* Container Objects::
* Function Objects: Function Objects<2>.
* Other Objects::
* C API for extension modules::

Fundamental Objects

* Type Objects::
* The None Object::

Type Objects

* Creating Heap-Allocated Types::

Numeric Objects

* Integer Objects::
* Boolean Objects::
* Floating-Point Objects::
* Complex Number Objects::

Integer Objects

* Export API::
* PyLongWriter API::
* Deprecated API::

Floating-Point Objects

* Pack and Unpack functions::

Pack and Unpack functions

* Pack functions::
* Unpack functions::

Complex Number Objects

* Complex Numbers as C Structures::
* Complex Numbers as Python Objects::

Sequence Objects

* Bytes Objects::
* Byte Array Objects::
* Unicode Objects and Codecs::
* Tuple Objects::
* Struct Sequence Objects::
* List Objects::

Byte Array Objects

* Type check macros::
* Direct API functions::
* Macros::

Unicode Objects and Codecs

* Unicode Objects::
* Built-in Codecs::
* Methods and Slot Functions::
* PyUnicodeWriter::
* Deprecated API: Deprecated API<2>.

Unicode Objects

* Unicode Type::
* Unicode Character Properties::
* Creating and accessing Unicode strings::
* Locale Encoding::
* File System Encoding::
* wchar_t Support::

Built-in Codecs

* Generic Codecs::
* UTF-8 Codecs::
* UTF-32 Codecs::
* UTF-16 Codecs::
* UTF-7 Codecs::
* Unicode-Escape Codecs::
* Raw-Unicode-Escape Codecs::
* Latin-1 Codecs::
* ASCII Codecs::
* Character Map Codecs::
* MBCS codecs for Windows::

Container Objects

* Dictionary Objects::
* Set Objects::

Dictionary Objects

* Dictionary View Objects::
* Ordered Dictionaries::

Set Objects

* Deprecated API: Deprecated API<3>.

Function Objects

* Function Objects: Function Objects<3>.
* Instance Method Objects::
* Method Objects::
* Cell Objects::
* Code Objects::
* Code Object Flags::
* Extra information::

Other Objects

* File Objects::
* Module Objects::
* Module definitions::
* Creating extension modules dynamically::
* Support functions::
* Iterator Objects::
* Descriptor Objects::
* Slice Objects::
* MemoryView objects::
* Pickle buffer objects::
* Weak Reference Objects: Weak Reference Objects<2>.
* Capsules: Capsules<2>.
* Frame Objects::
* Generator Objects::
* Coroutine Objects: Coroutine Objects<2>.
* Context Variables Objects::
* Objects for Type Hinting::

File Objects

* Deprecated API: Deprecated API<4>.

Module definitions

* Module slots::

Support functions

* Module lookup (single-phase initialization): Module lookup single-phase initialization.

Iterator Objects

* Range Objects::
* Builtin Iterator Types::
* Other Iterator Objects::

Descriptor Objects

* Built-in descriptors::

Slice Objects

* Ellipsis Object::

Frame Objects

* Frame Locals Proxies::
* Legacy Local Variable APIs::
* Internal Frames::

Generator Objects

* Asynchronous Generator Objects::
* Deprecated API: Deprecated API<5>.

C API for extension modules

* Curses C API::
* Internal data::
* DateTime Objects: DateTime Objects<2>.
* Internal data: Internal data<2>.

Initialization, Finalization, and Threads

* Before Python Initialization::
* Global configuration variables::
* Initializing and finalizing the interpreter::
* Process-wide parameters::
* Thread State and the Global Interpreter Lock::
* Sub-interpreter support::
* Asynchronous Notifications::
* Profiling and Tracing::
* Reference tracing::
* Advanced Debugger Support::
* Thread Local Storage Support::
* Synchronization Primitives: Synchronization Primitives<2>.
* Operating System Thread APIs::

Thread State and the Global Interpreter Lock

* Detaching the thread state from extension code::
* Non-Python created threads::
* Supporting subinterpreters in non-Python threads::
* Cautions about fork(): Cautions about fork.
* Cautions regarding runtime finalization::
* High-level API::
* Low-level API::

Sub-interpreter support

* A Per-Interpreter GIL::
* Bugs and caveats::

Thread Local Storage Support

* Thread Specific Storage (TSS) API: Thread Specific Storage TSS API.
* Thread Local Storage (TLS) API: Thread Local Storage TLS API.

Thread Specific Storage (TSS) API

* Dynamic Allocation::
* Methods::

Synchronization Primitives

* Python Critical Section API::
* Legacy Locking APIs::

Python Initialization Configuration

* PyInitConfig C API::
* Configuration Options::
* Runtime Python configuration API::
* PyConfig C API::
* Py_GetArgcArgv(): Py_GetArgcArgv.
* Delaying main module execution::

PyInitConfig C API

* Example: Example<17>.
* Create Config::
* Error Handling::
* Get Options::
* Set Options::
* Module::
* Initialize Python::

PyConfig C API

* Example: Example<18>.
* PyWideStringList::
* PyStatus::
* PyPreConfig::
* Preinitialize Python with PyPreConfig::
* PyConfig::
* Initialization with PyConfig::
* Isolated Configuration::
* Python Configuration::
* Python Path Configuration::

Memory Management

* Overview: Overview<4>.
* Allocator Domains::
* Raw Memory Interface::
* Memory Interface::
* Object allocators::
* Default Memory Allocators::
* Customize Memory Allocators::
* Debug hooks on the Python memory allocators::
* The pymalloc allocator::
* The mimalloc allocator::
* tracemalloc C API::
* Examples: Examples<38>.

Memory Interface

* Deprecated aliases: Deprecated aliases<2>.

The pymalloc allocator

* Customize pymalloc Arena Allocator::

Object Implementation Support

* Allocating Objects on the Heap::
* Object Life Cycle::
* Common Object Structures::
* Type Object Structures::
* Supporting Cyclic Garbage Collection::

Allocating Objects on the Heap

* Deprecated aliases: Deprecated aliases<3>.

Object Life Cycle

* Life Events::
* Cyclic Isolate Destruction::
* Functions: Functions<14>.

Common Object Structures

* Base object types and macros::
* Implementing functions and methods::
* Accessing attributes of extension types::

Accessing attributes of extension types

* Member flags::
* Member types::
* Defining Getters and Setters::

Type Object Structures

* Quick Reference::
* PyTypeObject Definition::
* PyObject Slots::
* PyVarObject Slots::
* PyTypeObject Slots::
* Static Types::
* Heap Types::
* Number Object Structures::
* Mapping Object Structures::
* Sequence Object Structures::
* Buffer Object Structures::
* Async Object Structures::
* Slot Type typedefs::
* Examples: Examples<39>.

Quick Reference

* «tp slots»::
* sub-slots::
* slot typedefs::

Supporting Cyclic Garbage Collection

* Controlling the Garbage Collector State::
* Querying Garbage Collector State::

API and ABI Versioning

* Build-time version constants::
* Run-time version::
* Bit-packing macros::

Generating Execution Events

* Managing the Monitoring State::

Installing Python Modules

* Key terms::
* Basic usage: Basic usage<2>.
* How do I …?::
* Common installation issues::

How do I …?

* … install pip in versions of Python prior to Python 3.4?: … install pip in versions of Python prior to Python 3 4?.
* … install packages just for the current user?::
* … install scientific Python packages?::
* … work with multiple versions of Python installed in parallel?::

Common installation issues

* Installing into the system Python on Linux::
* Pip not installed::
* Installing binary extensions::

Python HOWTOs

* A Conceptual Overview of asyncio::
* Porting Extension Modules to Python 3::
* Curses Programming with Python::
* Descriptor Guide::
* Debugging C API extensions and CPython Internals with GDB::
* Enum HOWTO::
* Functional Programming HOWTO::
* Logging HOWTO::
* Logging Cookbook::
* Regular Expression HOWTO::
* Socket Programming HOWTO::
* Sorting Techniques::
* Unicode HOWTO::
* HOWTO Fetch Internet Resources Using The urllib Package::
* An introduction to the ipaddress module::
* Instrumenting CPython with DTrace and SystemTap::
* Python support for the Linux perf profiler::
* Annotations Best Practices::
* Isolating Extension Modules::
* timer file descriptor HOWTO::
* The Python 2.3 Method Resolution Order: The Python 2 3 Method Resolution Order.
* Python support for free threading::
* C API Extension Support for Free Threading::
* Remote debugging attachment protocol::
* Permission requirements::
* Locating the PyRuntime structure::
* Reading _Py_DebugOffsets::
* Locating the interpreter and thread state::
* Writing control information::
* Summary::

A Conceptual Overview of asyncio

* A conceptual overview part 1; the high-level: A conceptual overview part 1 the high-level.
* A conceptual overview part 2; the nuts and bolts: A conceptual overview part 2 the nuts and bolts.

A conceptual overview part 1: the high-level

* Event Loop: Event Loop<2>.
* Asynchronous functions and coroutines::
* Tasks: Tasks<2>.
* await::

A conceptual overview part 2: the nuts and bolts

* The inner workings of coroutines::
* Futures: Futures<2>.
* A homemade asyncio.sleep: A homemade asyncio sleep.

Curses Programming with Python

* What is curses?::
* Starting and ending a curses application::
* Windows and Pads::
* Displaying Text::
* User Input::
* For More Information::

What is curses?

* The Python curses module::

Displaying Text

* Attributes and Color::

Descriptor Guide

* Primer::
* Complete Practical Example::
* Technical Tutorial::
* Pure Python Equivalents::

Primer

* Simple example; A descriptor that returns a constant: Simple example A descriptor that returns a constant.
* Dynamic lookups::
* Managed attributes::
* Customized names::
* Closing thoughts::

Complete Practical Example

* Validator class::
* Custom validators::
* Practical application::

Technical Tutorial

* Abstract::
* Definition and introduction::
* Descriptor protocol::
* Overview of descriptor invocation::
* Invocation from an instance::
* Invocation from a class::
* Invocation from super::
* Summary of invocation logic::
* Automatic name notification::
* ORM example::

Pure Python Equivalents

* Properties::
* Functions and methods::
* Kinds of methods::
* Static methods::
* Class methods::
* Member objects and __slots__::

Debugging C API extensions and CPython Internals with GDB

* Prerequisites::
* Using the Debug build and Development mode::
* Using the python-gdb extension::
* Use with GDB commands::

Prerequisites

* Setup with Python built from source::
* Setup for Python from a Linux distro::

Using the python-gdb extension

* Pretty-printers::
* py-list::
* py-up and py-down::
* py-bt::
* py-print::
* py-locals::

Enum HOWTO

* Programmatic access to enumeration members and their attributes::
* Duplicating enum members and values::
* Ensuring unique enumeration values::
* Using automatic values::
* Iteration: Iteration<2>.
* Comparisons: Comparisons<2>.
* Allowed members and attributes of enumerations::
* Restricted Enum subclassing::
* Dataclass support::
* Pickling::
* Functional API: Functional API<3>.
* Derived Enumerations::
* When to use __new__() vs. __init__(): When to use __new__ vs __init__.
* How are Enums and Flags different?::
* Enum Cookbook::
* Subclassing EnumType::

Derived Enumerations

* IntEnum::
* StrEnum::
* IntFlag::
* Flag::
* Others::

When to use __new__() vs. __init__()

* Finer Points::

Finer Points

* Supported __dunder__ names: Supported __dunder__ names<2>.
* Supported _sunder_ names: Supported _sunder_ names<2>.
* _Private__names::
* Enum member type::
* Creating members that are mixed with other data types::
* Boolean value of Enum classes and members::
* Enum classes with methods::
* Combining members of Flag::
* Flag and IntFlag minutia::

How are Enums and Flags different?

* Enum Classes::
* Flag Classes::
* Enum Members (aka instances): Enum Members aka instances.
* Flag Members::

Enum Cookbook

* Omitting values::
* OrderedEnum::
* DuplicateFreeEnum::
* MultiValueEnum::
* Planet::
* TimePeriod::

Omitting values

* Using auto::
* Using object::
* Using a descriptive string::
* Using a custom __new__(): Using a custom __new__.

Functional Programming HOWTO

* Introduction: Introduction<14>.
* Iterators::
* Generator expressions and list comprehensions::
* Generators::
* Built-in functions: Built-in functions<2>.
* The itertools module::
* The functools module::
* Small functions and the lambda expression::
* Revision History and Acknowledgements::
* References: References<2>.

Introduction

* Formal provability::
* Modularity::
* Ease of debugging and testing::
* Composability::

Iterators

* Data Types That Support Iterators::

Generators

* Passing values into a generator::

The itertools module

* Creating new iterators::
* Calling functions on elements::
* Selecting elements::
* Combinatoric functions::
* Grouping elements::

The functools module

* The operator module::

References

* General::
* Python-specific::
* Python documentation::

Logging HOWTO

* Basic Logging Tutorial::
* Advanced Logging Tutorial::
* Logging Levels: Logging Levels<2>.
* Useful Handlers::
* Exceptions raised during logging::
* Using arbitrary objects as messages::
* Optimization::
* Other resources::

Basic Logging Tutorial

* When to use logging::
* A simple example::
* Logging to a file::
* Logging variable data::
* Changing the format of displayed messages::
* Displaying the date/time in messages::
* Next Steps::

Advanced Logging Tutorial

* Logging Flow::
* Loggers::
* Handlers::
* Formatters::
* Configuring Logging::
* What happens if no configuration is provided::
* Configuring Logging for a Library::

Logging Levels

* Custom Levels::

Logging Cookbook

* Using logging in multiple modules::
* Logging from multiple threads::
* Multiple handlers and formatters::
* Logging to multiple destinations::
* Custom handling of levels::
* Configuration server example::
* Dealing with handlers that block::
* Sending and receiving logging events across a network::
* Adding contextual information to your logging output::
* Use of contextvars::
* Imparting contextual information in handlers::
* Logging to a single file from multiple processes::
* Using file rotation::
* Use of alternative formatting styles::
* Customizing LogRecord::
* Subclassing QueueHandler and QueueListener- a ZeroMQ example::
* Subclassing QueueHandler and QueueListener- a pynng example::
* An example dictionary-based configuration::
* Using a rotator and namer to customize log rotation processing::
* A more elaborate multiprocessing example::
* Inserting a BOM into messages sent to a SysLogHandler::
* Implementing structured logging::
* Customizing handlers with dictConfig(): Customizing handlers with dictConfig.
* Using particular formatting styles throughout your application::
* Configuring filters with dictConfig(): Configuring filters with dictConfig.
* Customized exception formatting::
* Speaking logging messages::
* Buffering logging messages and outputting them conditionally::
* Sending logging messages to email, with buffering: Sending logging messages to email with buffering.
* Formatting times using UTC (GMT) via configuration: Formatting times using UTC GMT via configuration.
* Using a context manager for selective logging::
* A CLI application starter template::
* A Qt GUI for logging::
* Logging to syslog with RFC5424 support::
* How to treat a logger like an output stream::
* How to uniformly handle newlines in logging output::
* Patterns to avoid::
* Other resources: Other resources<2>.

Sending and receiving logging events across a network

* Running a logging socket listener in production::

Adding contextual information to your logging output

* Using LoggerAdapters to impart contextual information::
* Using Filters to impart contextual information::

Using LoggerAdapters to impart contextual information

* Using objects other than dicts to pass contextual information::

Logging to a single file from multiple processes

* Using concurrent.futures.ProcessPoolExecutor: Using concurrent futures ProcessPoolExecutor.
* Deploying Web applications using Gunicorn and uWSGI::

Subclassing QueueHandler and QueueListener- a ZeroMQ example

* Subclass QueueHandler::
* Subclass QueueListener::

Subclassing QueueHandler and QueueListener- a pynng example

* Subclass QueueListener: Subclass QueueListener<2>.
* Subclass QueueHandler: Subclass QueueHandler<2>.

Using particular formatting styles throughout your application

* Using LogRecord factories::
* Using custom message objects::

Patterns to avoid

* Opening the same log file multiple times::
* Using loggers as attributes in a class or passing them as parameters::
* Adding handlers other than NullHandler to a logger in a library::
* Creating a lot of loggers::

Regular Expression HOWTO

* Introduction: Introduction<15>.
* Simple Patterns::
* Using Regular Expressions::
* More Pattern Power::
* Modifying Strings::
* Common Problems::
* Feedback::

Simple Patterns

* Matching Characters::
* Repeating Things::

Using Regular Expressions

* Compiling Regular Expressions::
* The Backslash Plague::
* Performing Matches::
* Module-Level Functions: Module-Level Functions<3>.
* Compilation Flags::

More Pattern Power

* More Metacharacters::
* Grouping::
* Non-capturing and Named Groups::
* Lookahead Assertions::

Modifying Strings

* Splitting Strings::
* Search and Replace: Search and Replace<2>.

Common Problems

* Use String Methods::
* match() versus search(): match versus search.
* Greedy versus Non-Greedy::
* Using re.VERBOSE: Using re VERBOSE.

Socket Programming HOWTO

* Sockets::
* Creating a Socket::
* Using a Socket::
* Disconnecting::
* Non-blocking Sockets::

Sockets

* History::

Creating a Socket

* IPC::

Using a Socket

* Binary Data::

Disconnecting

* When Sockets Die::

Sorting Techniques

* Sorting Basics::
* Key Functions::
* Operator Module Functions and Partial Function Evaluation::
* Ascending and Descending::
* Sort Stability and Complex Sorts::
* Decorate-Sort-Undecorate::
* Comparison Functions::
* Strategies For Unorderable Types and Values::
* Odds and Ends::
* Partial Sorts::

Unicode HOWTO

* Introduction to Unicode::
* Python’s Unicode Support::
* Reading and Writing Unicode Data::
* Acknowledgements: Acknowledgements<10>.

Introduction to Unicode

* Definitions::
* Encodings::
* References: References<3>.

Python’s Unicode Support

* The String Type::
* Converting to Bytes::
* Unicode Literals in Python Source Code::
* Unicode Properties::
* Comparing Strings::
* Unicode Regular Expressions::
* References: References<4>.

Reading and Writing Unicode Data

* Unicode filenames::
* Tips for Writing Unicode-aware Programs::
* References: References<5>.

Tips for Writing Unicode-aware Programs

* Converting Between File Encodings::
* Files in an Unknown Encoding::

HOWTO Fetch Internet Resources Using The urllib Package

* Introduction: Introduction<16>.
* Fetching URLs::
* Handling Exceptions::
* info and geturl::
* Openers and Handlers::
* Basic Authentication::
* Proxies::
* Sockets and Layers::
* Footnotes::

Fetching URLs

* Data::
* Headers::

Handling Exceptions

* URLError::
* HTTPError::
* Wrapping it Up::

HTTPError

* Error Codes::

Wrapping it Up

* Number 1::
* Number 2::

An introduction to the ipaddress module

* Creating Address/Network/Interface objects::
* Inspecting Address/Network/Interface Objects::
* Networks as lists of Addresses::
* Comparisons: Comparisons<3>.
* Using IP Addresses with other modules::
* Getting more detail when instance creation fails::

Creating Address/Network/Interface objects

* A Note on IP Versions::
* IP Host Addresses::
* Defining Networks::
* Host Interfaces::

Instrumenting CPython with DTrace and SystemTap

* Enabling the static markers::
* Static DTrace probes::
* Static SystemTap markers::
* Available static markers::
* SystemTap Tapsets::
* Examples: Examples<40>.

Python support for the Linux perf profiler

* How to enable perf profiling support::
* How to obtain the best results::
* How to work without frame pointers::

Annotations Best Practices

* Accessing The Annotations Dict Of An Object In Python 3.10 And Newer: Accessing The Annotations Dict Of An Object In Python 3 10 And Newer.
* Accessing The Annotations Dict Of An Object In Python 3.9 And Older: Accessing The Annotations Dict Of An Object In Python 3 9 And Older.
* Manually Un-Stringizing Stringized Annotations::
* Best Practices For __annotations__ In Any Python Version::
* __annotations__ Quirks::

Isolating Extension Modules

* Who should read this::
* Background: Background<2>.
* Making Modules Safe with Multiple Interpreters::
* Heap Types: Heap Types<2>.
* Open Issues::

Background

* Enter Per-Module State::
* Isolated Module Objects::
* Surprising Edge Cases::

Making Modules Safe with Multiple Interpreters

* Managing Global State::
* Managing Per-Module State::
* Opt-Out; Limiting to One Module Object per Process: Opt-Out Limiting to One Module Object per Process.
* Module State Access from Functions::

Heap Types

* Changing Static Types to Heap Types::
* Defining Heap Types::
* Garbage-Collection Protocol::
* Module State Access from Classes::
* Module State Access from Regular Methods::
* Module State Access from Slot Methods, Getters and Setters: Module State Access from Slot Methods Getters and Setters.
* Lifetime of the Module State::

Garbage-Collection Protocol

* tp_traverse in Python 3.8 and lower: tp_traverse in Python 3 8 and lower.
* Delegating tp_traverse::
* Defining tp_dealloc::
* Not overriding tp_free::
* Avoiding PyObject_New::

Open Issues

* Per-Class Scope::
* Lossless Conversion to Heap Types::

timer file descriptor HOWTO

* Examples: Examples<41>.

The Python 2.3 Method Resolution Order

* The beginning::
* The C3 Method Resolution Order::
* Examples: Examples<42>.
* Bad Method Resolution Orders::
* The end::
* Resources::

Python support for free threading

* Installation: Installation<2>.
* Identifying free-threaded Python::
* The global interpreter lock in free-threaded Python::
* Thread safety::
* Known limitations::
* Behavioral changes::

Known limitations

* Immortalization::
* Frame objects: Frame objects<2>.
* Iterators: Iterators<2>.
* Single-threaded performance::

Behavioral changes

* Context variables::
* Warning filters::

C API Extension Support for Free Threading

* Identifying the Free-Threaded Build in C::
* Module Initialization::
* General API Guidelines::
* Borrowed References::
* Memory Allocation APIs::
* Thread State and GIL APIs::
* Protecting Internal Extension State::
* Critical Sections::
* Building Extensions for the Free-Threaded Build::

Module Initialization

* Multi-Phase Initialization::
* Single-Phase Initialization::

General API Guidelines

* Container Thread Safety::

Container Thread Safety

* PyDict_Next::

Critical Sections

* What Are Critical Sections?::
* Using Critical Sections::
* How Critical Sections Work::
* Deadlock Avoidance::
* Important Considerations::

Building Extensions for the Free-Threaded Build

* Limited C API and Stable ABI::
* Windows: Windows<84>.

Remote debugging attachment protocol

* Disabling remote debugging::

Python Frequently Asked Questions

* General Python FAQ::
* Programming FAQ::
* Design and History FAQ::
* Library and Extension FAQ::
* Extending/Embedding FAQ::
* Python on Windows FAQ::
* Graphic User Interface FAQ::
* «Why is Python Installed on my Computer?» FAQ::

General Python FAQ

* General Information::
* Python in the real world::

General Information

* What is Python?::
* What is the Python Software Foundation?::
* Are there copyright restrictions on the use of Python?::
* Why was Python created in the first place?::
* What is Python good for?::
* How does the Python version numbering scheme work?::
* How do I obtain a copy of the Python source?::
* How do I get documentation on Python?::
* I’ve never programmed before. Is there a Python tutorial?: I’ve never programmed before Is there a Python tutorial?.
* Is there a newsgroup or mailing list devoted to Python?::
* How do I get a beta test version of Python?::
* How do I submit bug reports and patches for Python?::
* Are there any published articles about Python that I can reference?::
* Are there any books on Python?::
* Where in the world is www.python.org located?: Where in the world is www python org located?.
* Why is it called Python?::
* Do I have to like «Monty Python’s Flying Circus»?::

Python in the real world

* How stable is Python?::
* How many people are using Python?::
* Have any significant projects been done in Python?::
* What new developments are expected for Python in the future?::
* Is it reasonable to propose incompatible changes to Python?::
* Is Python a good language for beginning programmers?::

Programming FAQ

* General Questions::
* Core Language::
* Numbers and strings::
* Performance: Performance<4>.
* Sequences (Tuples/Lists): Sequences Tuples/Lists.
* Objects::
* Modules: Modules<3>.

General Questions

* Is there a source code level debugger with breakpoints, single-stepping, etc.?: Is there a source code level debugger with breakpoints single-stepping etc ?.
* Are there tools to help find bugs or perform static analysis?::
* How can I create a stand-alone binary from a Python script?::
* Are there coding standards or a style guide for Python programs?::

Core Language

* Why am I getting an UnboundLocalError when the variable has a value?::
* What are the rules for local and global variables in Python?::
* Why do lambdas defined in a loop with different values all return the same result?::
* How do I share global variables across modules?::
* What are the «best practices» for using import in a module?::
* Why are default values shared between objects?::
* How can I pass optional or keyword parameters from one function to another?::
* What is the difference between arguments and parameters?::
* Why did changing list “y” also change list “x”?::
* How do I write a function with output parameters (call by reference)?: How do I write a function with output parameters call by reference ?.
* How do you make a higher order function in Python?::
* How do I copy an object in Python?::
* How can I find the methods or attributes of an object?::
* How can my code discover the name of an object?::
* What’s up with the comma operator’s precedence?::
* Is there an equivalent of C’s «?;» ternary operator?: Is there an equivalent of C’s «? » ternary operator?.
* Is it possible to write obfuscated one-liners in Python?::
* What does the slash(/) in the parameter list of a function mean?: What does the slash / in the parameter list of a function mean?.

Numbers and strings

* How do I specify hexadecimal and octal integers?::
* Why does -22 // 10 return -3?::
* How do I get int literal attribute instead of SyntaxError?::
* How do I convert a string to a number?::
* How do I convert a number to a string?::
* How do I modify a string in place?::
* How do I use strings to call functions/methods?::
* Is there an equivalent to Perl’s chomp() for removing trailing newlines from strings?: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?.
* Is there a scanf() or sscanf() equivalent?: Is there a scanf or sscanf equivalent?.
* What does UnicodeDecodeError or UnicodeEncodeError error mean?::
* Can I end a raw string with an odd number of backslashes?::

Performance

* My program is too slow. How do I speed it up?: My program is too slow How do I speed it up?.
* What is the most efficient way to concatenate many strings together?::

Sequences (Tuples/Lists)

* How do I convert between tuples and lists?::
* What’s a negative index?::
* How do I iterate over a sequence in reverse order?::
* How do you remove duplicates from a list?::
* How do you remove multiple items from a list?::
* How do you make an array in Python?::
* How do I create a multidimensional list?::
* How do I apply a method or function to a sequence of objects?::
* Why does a_tuple[i] += [“item”] raise an exception when the addition works?::
* I want to do a complicated sort; can you do a Schwartzian Transform in Python?: I want to do a complicated sort can you do a Schwartzian Transform in Python?.
* How can I sort one list by values from another list?::

Objects

* What is a class?::
* What is a method?::
* What is self?::
* How do I check if an object is an instance of a given class or of a subclass of it?::
* What is delegation?::
* How do I call a method defined in a base class from a derived class that extends it?::
* How can I organize my code to make it easier to change the base class?::
* How do I create static class data and static class methods?::
* How can I overload constructors (or methods) in Python?: How can I overload constructors or methods in Python?.
* I try to use __spam and I get an error about _SomeClassName__spam.: I try to use __spam and I get an error about _SomeClassName__spam.
* My class defines __del__ but it is not called when I delete the object.: My class defines __del__ but it is not called when I delete the object.
* How do I get a list of all instances of a given class?::
* Why does the result of id() appear to be not unique?: Why does the result of id appear to be not unique?.
* When can I rely on identity tests with the is operator?::
* How can a subclass control what data is stored in an immutable instance?::
* How do I cache method calls?::

Modules

* How do I create a .pyc file?: How do I create a pyc file?.
* How do I find the current module name?::
* How can I have modules that mutually import each other?::
* __import__(“x.y.z”) returns <module “x”>; how do I get z?: __import__ “x y z” returns <module “x”>; how do I get z?.
* When I edit an imported module and reimport it, the changes don’t show up. Why does this happen?: When I edit an imported module and reimport it the changes don’t show up Why does this happen?.

Design and History FAQ

* Why does Python use indentation for grouping of statements?::
* Why am I getting strange results with simple arithmetic operations?::
* Why are floating-point calculations so inaccurate?::
* Why are Python strings immutable?::
* Why must “self” be used explicitly in method definitions and calls?::
* Why can’t I use an assignment in an expression?::
* Why does Python use methods for some functionality (e.g. list.index()) but functions for other (e.g. len(list))?: Why does Python use methods for some functionality e g list index but functions for other e g len list ?.
* Why is join() a string method instead of a list or tuple method?: Why is join a string method instead of a list or tuple method?.
* How fast are exceptions?::
* Why isn’t there a switch or case statement in Python?::
* Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?::
* Why can’t lambda expressions contain statements?::
* Can Python be compiled to machine code, C or some other language?: Can Python be compiled to machine code C or some other language?.
* How does Python manage memory?::
* Why doesn’t CPython use a more traditional garbage collection scheme?::
* Why isn’t all memory freed when CPython exits?::
* Why are there separate tuple and list data types?::
* How are lists implemented in CPython?::
* How are dictionaries implemented in CPython?::
* Why must dictionary keys be immutable?::
* Why doesn’t list.sort() return the sorted list?: Why doesn’t list sort return the sorted list?.
* How do you specify and enforce an interface spec in Python?::
* Why is there no goto?::
* Why can’t raw strings (r-strings) end with a backslash?: Why can’t raw strings r-strings end with a backslash?.
* Why doesn’t Python have a «with» statement for attribute assignments?::
* Why don’t generators support the with statement?::
* Why are colons required for the if/while/def/class statements?::
* Why does Python allow commas at the end of lists and tuples?::

Library and Extension FAQ

* General Library Questions::
* Common tasks::
* Threads::
* Input and Output::
* Network/Internet Programming::
* Databases::
* Mathematics and Numerics::

General Library Questions

* How do I find a module or application to perform task X?::
* Where is the math.py (socket.py, regex.py, etc.) source file?: Where is the math py socket py regex py etc source file?.
* How do I make a Python script executable on Unix?::
* Is there a curses/termcap package for Python?::
* Is there an equivalent to C’s onexit() in Python?: Is there an equivalent to C’s onexit in Python?.
* Why don’t my signal handlers work?::

Common tasks

* How do I test a Python program or component?::
* How do I create documentation from doc strings?::
* How do I get a single keypress at a time?::

Threads

* How do I program using threads?::
* None of my threads seem to run; why?: None of my threads seem to run why?.
* How do I parcel out work among a bunch of worker threads?::
* What kinds of global value mutation are thread-safe?::
* Can’t we get rid of the Global Interpreter Lock?::

Input and Output

* How do I delete a file? (And other file questions…): How do I delete a file? And other file questions….
* How do I copy a file?::
* How do I read (or write) binary data?: How do I read or write binary data?.
* I can’t seem to use os.read() on a pipe created with os.popen(); why?: I can’t seem to use os read on a pipe created with os popen ; why?.
* How do I access the serial (RS232) port?: How do I access the serial RS232 port?.
* Why doesn’t closing sys.stdout (stdin, stderr) really close it?: Why doesn’t closing sys stdout stdin stderr really close it?.

Network/Internet Programming

* What WWW tools are there for Python?::
* What module should I use to help with generating HTML?::
* How do I send mail from a Python script?::
* How do I avoid blocking in the connect() method of a socket?: How do I avoid blocking in the connect method of a socket?.

Databases

* Are there any interfaces to database packages in Python?::
* How do you implement persistent objects in Python?::

Mathematics and Numerics

* How do I generate random numbers in Python?::

Extending/Embedding FAQ

* Can I create my own functions in C?::
* Can I create my own functions in C++?::
* Writing C is hard; are there any alternatives?::
* How can I execute arbitrary Python statements from C?::
* How can I evaluate an arbitrary Python expression from C?::
* How do I extract C values from a Python object?::
* How do I use Py_BuildValue() to create a tuple of arbitrary length?: How do I use Py_BuildValue to create a tuple of arbitrary length?.
* How do I call an object’s method from C?::
* How do I catch the output from PyErr_Print() (or anything that prints to stdout/stderr)?: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?.
* How do I access a module written in Python from C?::
* How do I interface to C++ objects from Python?::
* I added a module using the Setup file and the make fails; why?::
* How do I debug an extension?::
* I want to compile a Python module on my Linux system, but some files are missing. Why?: I want to compile a Python module on my Linux system but some files are missing Why?.
* How do I tell «incomplete input» from «invalid input»?::
* How do I find undefined g++ symbols __builtin_new or __pure_virtual?::
* Can I create an object class with some methods implemented in C and others in Python (e.g. through inheritance)?: Can I create an object class with some methods implemented in C and others in Python e g through inheritance ?.

Python on Windows FAQ

* How do I run a Python program under Windows?::
* How do I make Python scripts executable?::
* Why does Python sometimes take so long to start?::
* How do I make an executable from a Python script?::
* Is a *.pyd file the same as a DLL?: Is a * pyd file the same as a DLL?.
* How can I embed Python into a Windows application?::
* How do I keep editors from inserting tabs into my Python source?::
* How do I check for a keypress without blocking?::
* How do I solve the missing api-ms-win-crt-runtime-l1-1-0.dll error?: How do I solve the missing api-ms-win-crt-runtime-l1-1-0 dll error?.

Graphic User Interface FAQ

* General GUI Questions::
* What GUI toolkits exist for Python?::
* Tkinter questions::

Tkinter questions

* How do I freeze Tkinter applications?::
* Can I have Tk events handled while waiting for I/O?::
* I can’t get key bindings to work in Tkinter; why?: I can’t get key bindings to work in Tkinter why?.

«Why is Python Installed on my Computer?» FAQ

* What is Python?: What is Python?<2>.
* Why is Python installed on my machine?::
* Can I delete Python?::

Deprecations

* Pending removal in Python 3.15: Pending removal in Python 3 15<7>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<7>.
* Pending removal in Python 3.17: Pending removal in Python 3 17<4>.
* Pending removal in Python 3.18: Pending removal in Python 3 18<5>.
* Pending removal in Python 3.19: Pending removal in Python 3 19<3>.
* Pending removal in future versions: Pending removal in future versions<7>.
* C API deprecations::

C API deprecations

* Pending removal in Python 3.15: Pending removal in Python 3 15<8>.
* Pending removal in Python 3.18: Pending removal in Python 3 18<6>.
* Pending removal in future versions: Pending removal in future versions<8>.

About this documentation

* Contributors to the Python documentation::

Come comportarsi con i bug

* Errori nella Documentazione::
* Utilizzo dell’Issue Tracker di Python::
* Come iniziare a contribuire a Python in autonomia::

Storia e licenza

* Storia del software::
* Termini e condizioni di accesso o di utilizzo di Python::
* Licenze e riconoscimenti per il software incorporato::

Termini e condizioni di accesso o di utilizzo di Python

* PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2::
* CONTRATTO DI LICENZA DI BEOPEN.COM PER PYTHON 2.0: CONTRATTO DI LICENZA DI BEOPEN COM PER PYTHON 2 0.
* CNRI CONTRATTO DI LICENZA PER PYTHON 1.6.1: CNRI CONTRATTO DI LICENZA PER PYTHON 1 6 1.
* CWI CONTRATTO DI LICENZA PER PYTHON DA 0.9.0 A 1.2: CWI CONTRATTO DI LICENZA PER PYTHON DA 0 9 0 A 1 2.
* ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON DOCUMENTATION::

Licenze e riconoscimenti per il software incorporato

* Mersenne Twister::
* Socket::
* Servizi di socket asincrone::
* Gestione dei cookie::
* Tracciabilità dell’esecuzione::
* Funzioni UUencode e UUdecode::
* Chiamate di procedura remota XML::
* test_epoll::
* Select kqueue::
* SipHash24::
* strtod e dtoa::
* 7.4 OpenSSL: 7 4 OpenSSL.
* expat::
* libffi::
* zlib: zlib<4>.
* cfuhash::
* libmpdec::
* W3C C14N test suite::
* mimalloc::
* asyncio: asyncio<15>.
* Global Unbounded Sequences (GUS): Global Unbounded Sequences GUS.
* Zstandard bindings::



File: python.info,  Node: Novità in Python,  Next: Tutorial su Python,  Prev: Top,  Up: Top

1 Novità in Python
******************

La serie di articoli «Novità in Python» offre una panoramica sui
cambiamenti più importanti tra le principali versioni di Python.  Sono
una «lettura obbligata» per chiunque desideri rimanere aggiornato dopo
il rilascio di una nuova release.

* Menu:

* What’s new in Python 3.14: What’s new in Python 3 14.
* What’s New In Python 3.13: What’s New In Python 3 13.
* Novità in Python 3.12: Novità in Python 3 12.
* What’s New In Python 3.11: What’s New In Python 3 11.
* What’s New In Python 3.10: What’s New In Python 3 10.
* What’s New In Python 3.9: What’s New In Python 3 9.
* What’s New In Python 3.8: What’s New In Python 3 8.
* What’s New In Python 3.7: What’s New In Python 3 7.
* What’s New In Python 3.6: What’s New In Python 3 6.
* What’s New In Python 3.5: What’s New In Python 3 5.
* What’s New In Python 3.4: What’s New In Python 3 4.
* What’s New In Python 3.3: What’s New In Python 3 3.
* What’s New In Python 3.2: What’s New In Python 3 2.
* What’s New In Python 3.1: What’s New In Python 3 1.
* What’s New In Python 3.0: What’s New In Python 3 0.
* What’s New in Python 2.7: What’s New in Python 2 7.
* What’s New in Python 2.6: What’s New in Python 2 6.
* What’s New in Python 2.5: What’s New in Python 2 5.
* What’s New in Python 2.4: What’s New in Python 2 4.
* What’s New in Python 2.3: What’s New in Python 2 3.
* What’s New in Python 2.2: What’s New in Python 2 2.
* What’s New in Python 2.1: What’s New in Python 2 1.
* What’s New in Python 2.0: What’s New in Python 2 0.
* Changelog::


File: python.info,  Node: What’s new in Python 3 14,  Next: What’s New In Python 3 13,  Up: Novità in Python

1.1 What’s new in Python 3.14
=============================


Editors: Adam Turner and Hugo van Kemenade

This article explains the new features in Python 3.14, compared to 3.13.
Python 3.14 was released on 7 October 2025.  For full details, see the
*note changelog: 142.

Vedi anche
..........

PEP 745(1) – Python 3.14 release schedule

* Menu:

* Summary – Release highlights::
* New features::
* Other language changes::
* New modules::
* Improved modules::
* Optimizations::
* Removed::
* Deprecated::
* CPython bytecode changes::
* C API changes::
* Build changes::
* Porting to Python 3.14: Porting to Python 3 14.
* Notable changes in 3.14.1: Notable changes in 3 14 1.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0745/


File: python.info,  Node: Summary – Release highlights,  Next: New features,  Up: What’s new in Python 3 14

1.1.1 Summary – Release highlights
----------------------------------

Python 3.14 is the latest stable release of the Python programming
language, with a mix of changes to the language, the implementation, and
the standard library.  The biggest changes include *note template string
literals: 144, *note deferred evaluation of annotations: 145, and
support for *note subinterpreters: 146. in the standard library.

The library changes include significantly improved capabilities for
*note introspection in asyncio: 147, *note support for Zstandard: 148.
via a new *note compression.zstd: 23. module, syntax highlighting in the
REPL, as well as the usual deprecations and removals, and improvements
in user-friendliness and correctness.

This article doesn’t attempt to provide a complete specification of all
new features, but instead gives a convenient overview.  For full details
refer to the documentation, such as the *note Library Reference: 149.
and *note Language Reference: 14a.  To understand the complete
implementation and design rationale for a change, refer to the PEP for a
particular new feature; but note that PEPs usually are not kept
up-to-date once a feature has been fully implemented.  See *note Porting
to Python 3.14: 14b. for guidance on upgrading from earlier versions of
Python.

__________________________________________________________________

Interpreter improvements:

   * PEP 649(1) and PEP 749(2): *note Deferred evaluation of
     annotations: 145.

   * PEP 734(3): *note Multiple interpreters in the standard library:
     146.

   * PEP 750(4): *note Template strings: 144.

   * PEP 758(5): *note Allow except and except* expressions without
     brackets: 14c.

   * PEP 765(6): *note Control flow in finally blocks: 14d.

   * PEP 768(7): *note Safe external debugger interface for CPython:
     14e.

   * *note A new type of interpreter: 14f.

   * *note Free-threaded mode improvements: 150.

   * *note Improved error messages: 151.

   * *note Incremental garbage collection: 152.

Significant improvements in the standard library:

   * PEP 784(8): *note Zstandard support in the standard library: 148.

   * *note Asyncio introspection capabilities: 147.

   * *note Concurrent safe warnings control: 153.

   * *note Syntax highlighting in the default interactive shell: 154,
     and color output in several standard library CLIs

C API improvements:

   * PEP 741(9): *note Python configuration C API: 155.

Platform support:

   * PEP 776(10): Emscripten is now an *note officially supported
     platform: 156, at tier 3(11).

Release changes:

   * PEP 779(12): *note Free-threaded Python is officially supported:
     157.

   * PEP 761(13): *note PGP signatures have been discontinued for
     official releases: 158.

   * *note Windows and macOS binary releases now support the
     experimental just-in-time compiler: 159.

   * *note Binary releases for Android are now provided: 156.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0649/

   (2) https://peps.python.org/pep-0749/

   (3) https://peps.python.org/pep-0734/

   (4) https://peps.python.org/pep-0750/

   (5) https://peps.python.org/pep-0758/

   (6) https://peps.python.org/pep-0765/

   (7) https://peps.python.org/pep-0768/

   (8) https://peps.python.org/pep-0784/

   (9) https://peps.python.org/pep-0741/

   (10) https://peps.python.org/pep-0776/

   (11) https://peps.python.org/pep-0011/#tier-3

   (12) https://peps.python.org/pep-0779/

   (13) https://peps.python.org/pep-0761/


File: python.info,  Node: New features,  Next: Other language changes,  Prev: Summary – Release highlights,  Up: What’s new in Python 3 14

1.1.2 New features
------------------

* Menu:

* PEP 649 & PEP 749; Deferred evaluation of annotations: PEP 649 & PEP 749 Deferred evaluation of annotations.
* PEP 734; Multiple interpreters in the standard library: PEP 734 Multiple interpreters in the standard library.
* PEP 750; Template string literals: PEP 750 Template string literals.
* PEP 768; Safe external debugger interface: PEP 768 Safe external debugger interface.
* A new type of interpreter::
* Free-threaded mode improvements::
* Improved error messages::
* PEP 784; Zstandard support in the standard library: PEP 784 Zstandard support in the standard library.
* Asyncio introspection capabilities::
* Concurrent safe warnings control::


File: python.info,  Node: PEP 649 & PEP 749 Deferred evaluation of annotations,  Next: PEP 734 Multiple interpreters in the standard library,  Up: New features

'PEP 649' & 'PEP 749': Deferred evaluation of annotations

The *note annotations: 15c. on functions, classes, and modules are no
longer evaluated eagerly.  Instead, annotations are stored in
special-purpose *note annotate functions: 15d. and evaluated only when
necessary (except if ‘from __future__ import annotations’ is used).

This change is designed to improve performance and usability of
annotations in Python in most circumstances.  The runtime cost for
defining annotations is minimized, but it remains possible to introspect
annotations at runtime.  It is no longer necessary to enclose
annotations in strings if they contain forward references.

The new *note annotationlib: 6. module provides tools for inspecting
deferred annotations.  Annotations may be evaluated in the *note VALUE:
15e. format (which evaluates annotations to runtime values, similar to
the behavior in earlier Python versions), the *note FORWARDREF: 15f.
format (which replaces undefined names with special markers), and the
*note STRING: 160. format (which returns annotations as strings).

This example shows how these formats behave:

     >>> from annotationlib import get_annotations, Format
     >>> def func(arg: Undefined):
     ...     pass
     >>> get_annotations(func, format=Format.VALUE)
     Traceback (most recent call last):
       ...
     NameError: name 'Undefined' is not defined
     >>> get_annotations(func, format=Format.FORWARDREF)
     {'arg': ForwardRef('Undefined', owner=<function func at 0x...>)}
     >>> get_annotations(func, format=Format.STRING)
     {'arg': 'Undefined'}

The *note porting: 161. section contains guidance on changes that may be
needed due to these changes, though in the majority of cases, code will
continue working as-is.

(Contributed by Jelle Zijlstra in PEP 749(1) and gh-119180(2); PEP
649(3) was written by Larry Hastings.)

Vedi anche
..........

PEP 649(4)

     Deferred Evaluation Of Annotations Using Descriptors

PEP 749(5)

     Implementing PEP 649

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0749/

   (2) https://github.com/python/cpython/issues/119180

   (3) https://peps.python.org/pep-0649/

   (4) https://peps.python.org/pep-0649/

   (5) https://peps.python.org/pep-0749/


File: python.info,  Node: PEP 734 Multiple interpreters in the standard library,  Next: PEP 750 Template string literals,  Prev: PEP 649 & PEP 749 Deferred evaluation of annotations,  Up: New features

'PEP 734': Multiple interpreters in the standard library

The CPython runtime supports running multiple copies of Python in the
same process simultaneously and has done so for over 20 years.  Each of
these separate copies is called an “interpreter”.  However, the feature
had been available only through the *note C-API: 163.

That limitation is removed in Python 3.14, with the new *note
concurrent.interpreters: 25. module.

There are at least two notable reasons why using multiple interpreters
has significant benefits:

   * they support a new (to Python), human-friendly concurrency model

   * true multi-core parallelism

For some use cases, concurrency in software improves efficiency and can
simplify design, at a high level.  At the same time, implementing and
maintaining all but the simplest concurrency is often a struggle for the
human brain.  That especially applies to plain threads (for example,
*note threading: f3.), where all memory is shared between all threads.

With multiple isolated interpreters, you can take advantage of a class
of concurrency models, like Communicating Sequential Processes (CSP) or
the actor model, that have found success in other programming languages,
like Smalltalk, Erlang, Haskell, and Go.  Think of multiple interpreters
as threads but with opt-in sharing.

Regarding multi-core parallelism: as of Python 3.12, interpreters are
now sufficiently isolated from one another to be used in parallel (see
PEP 684(1)).  This unlocks a variety of CPU-intensive use cases for
Python that were limited by the *note GIL: 164.

Using multiple interpreters is similar in many ways to *note
multiprocessing: 98, in that they both provide isolated logical
«processes» that can run in parallel, with no sharing by default.
However, when using multiple interpreters, an application will use fewer
system resources and will operate more efficiently (since it stays
within the same process).  Think of multiple interpreters as having the
isolation of processes with the efficiency of threads.

While the feature has been around for decades, multiple interpreters
have not been used widely, due to low awareness and the lack of a
standard library module.  Consequently, they currently have several
notable limitations, which are expected to improve significantly now
that the feature is going mainstream.

Current limitations:

   * starting each interpreter has not been optimized yet

   * each interpreter uses more memory than necessary (work continues on
     extensive internal sharing between interpreters)

   * there aren’t many options 'yet' for truly sharing objects or other
     data between interpreters (other than *note memoryview: 165.)

   * many third-party extension modules on PyPI are not yet compatible
     with multiple interpreters (all standard library extension modules
     'are' compatible)

   * the approach to writing applications that use multiple isolated
     interpreters is mostly unfamiliar to Python users, for now

The impact of these limitations will depend on future CPython
improvements, how interpreters are used, and what the community solves
through PyPI packages.  Depending on the use case, the limitations may
not have much impact, so try it out!

Furthermore, future CPython releases will reduce or eliminate overhead
and provide utilities that are less appropriate on PyPI. In the
meantime, most of the limitations can also be addressed through
extension modules, meaning PyPI packages can fill any gap for 3.14, and
even back to 3.12 where interpreters were finally properly isolated and
stopped sharing the *note GIL: 164.  Likewise, libraries on PyPI are
expected to emerge for high-level abstractions on top of interpreters.

Regarding extension modules, work is in progress to update some PyPI
projects, as well as tools like Cython, pybind11, nanobind, and PyO3.
The steps for isolating an extension module are found at *note Isolating
Extension Modules: 166.  Isolating a module has a lot of overlap with
what is required to support *note free-threading: 150, so the ongoing
work in the community in that area will help accelerate support for
multiple interpreters.

Also added in 3.14: *note concurrent.futures.InterpreterPoolExecutor:
167.

(Contributed by Eric Snow in gh-134939(2).)

Vedi anche
..........

PEP 734(3)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0684/

   (2) https://github.com/python/cpython/issues/134939

   (3) https://peps.python.org/pep-0734/


File: python.info,  Node: PEP 750 Template string literals,  Next: PEP 768 Safe external debugger interface,  Prev: PEP 734 Multiple interpreters in the standard library,  Up: New features

'PEP 750': Template string literals

Template strings are a new mechanism for custom string processing.  They
share the familiar syntax of f-strings but, unlike f-strings, return an
object representing the static and interpolated parts of the string,
instead of a simple *note str: 169.

To write a t-string, use a ‘'t'’ prefix instead of an ‘'f'’:

     >>> variety = 'Stilton'
     >>> template = t'Try some {variety} cheese!'
     >>> type(template)
     <class 'string.templatelib.Template'>

*note Template: 16a. objects provide access to the static and
interpolated (in curly braces) parts of a string 'before' they are
combined.  Iterate over ‘Template’ instances to access their parts in
order:

     >>> list(template)
     ['Try some ', Interpolation('Stilton', 'variety', None, ''), ' cheese!']

It’s easy to write (or call) code to process ‘Template’ instances.  For
example, here’s a function that renders static parts lowercase and *note
Interpolation: 16b. instances uppercase:

     from string.templatelib import Interpolation

     def lower_upper(template):
         """Render static parts lowercase and interpolations uppercase."""
         parts = []
         for part in template:
             if isinstance(part, Interpolation):
                 parts.append(str(part.value).upper())
             else:
                 parts.append(part.lower())
         return ''.join(parts)

     name = 'Wenslydale'
     template = t'Mister {name}'
     assert lower_upper(template) == 'mister WENSLYDALE'

Because ‘Template’ instances distinguish between static strings and
interpolations at runtime, they can be useful for sanitising user input.
Writing a ‘html()’ function that escapes user input in HTML is an
exercise left to the reader!  Template processing code can provide
improved flexibility.  For instance, a more advanced ‘html()’ function
could accept a ‘dict’ of HTML attributes directly in the template:

     attributes = {'src': 'limburger.jpg', 'alt': 'lovely cheese'}
     template = t'<img {attributes}>'
     assert html(template) == '<img src="limburger.jpg" alt="lovely cheese" />'

Of course, template processing code does not need to return a
string-like result.  An even 'more' advanced ‘html()’ could return a
custom type representing a DOM-like structure.

With t-strings in place, developers can write systems that sanitise SQL,
make safe shell operations, improve logging, tackle modern ideas in web
development (HTML, CSS, and so on), and implement lightweight custom
business DSLs.

(Contributed by Jim Baker, Guido van Rossum, Paul Everitt, Koudai Aono,
Lysandros Nikolaou, Dave Peck, Adam Turner, Jelle Zijlstra, Bénédikt
Tran, and Pablo Galindo Salgado in gh-132661(1).)

Vedi anche
..........

PEP 750(2).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132661

   (2) https://peps.python.org/pep-0750/


File: python.info,  Node: PEP 768 Safe external debugger interface,  Next: A new type of interpreter,  Prev: PEP 750 Template string literals,  Up: New features

'PEP 768': Safe external debugger interface

Python 3.14 introduces a zero-overhead debugging interface that allows
debuggers and profilers to safely attach to running Python processes
without stopping or restarting them.  This is a significant enhancement
to Python’s debugging capabilities, meaning that unsafe alternatives are
no longer required.

The new interface provides safe execution points for attaching debugger
code without modifying the interpreter’s normal execution path or adding
any overhead at runtime.  Due to this, tools can now inspect and
interact with Python applications in real-time, which is a crucial
capability for high-availability systems and production environments.

For convenience, this interface is implemented in the *note
sys.remote_exec(): 16d. function.  For example:

     import sys
     from tempfile import NamedTemporaryFile

     with NamedTemporaryFile(mode='w', suffix='.py', delete=False) as f:
         script_path = f.name
         f.write(f'import my_debugger; my_debugger.connect({os.getpid()})')

     # Execute in process with PID 1234
     print('Behold! An offering:')
     sys.remote_exec(1234, script_path)

This function allows sending Python code to be executed in a target
process at the next safe execution point.  However, tool authors can
also implement the protocol directly as described in the PEP, which
details the underlying mechanisms used to safely attach to running
processes.

The debugging interface has been carefully designed with security in
mind and includes several mechanisms to control access:

   * A *note PYTHON_DISABLE_REMOTE_DEBUG: 16e. environment variable.

   * A *note -X disable-remote-debug: 16f. command-line option.

   * A *note -without-remote-debug: 170. configure flag to completely
     disable the feature at build time.

(Contributed by Pablo Galindo Salgado, Matt Wozniski, and Ivona
Stojanovic in gh-131591(1).)

Vedi anche
..........

PEP 768(2).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131591

   (2) https://peps.python.org/pep-0768/


File: python.info,  Node: A new type of interpreter,  Next: Free-threaded mode improvements,  Prev: PEP 768 Safe external debugger interface,  Up: New features

1.1.2.5 A new type of interpreter
.................................

A new type of interpreter has been added to CPython.  It uses tail calls
between small C functions that implement individual Python opcodes,
rather than one large C ‘case’ statement.  For certain newer compilers,
this interpreter provides significantly better performance.  Preliminary
benchmarks suggest a geometric mean of 3-5% faster on the standard
‘pyperformance’ benchmark suite, depending on platform and architecture.
The baseline is Python 3.14 built with Clang 19, without this new
interpreter.

This interpreter currently only works with Clang 19 and newer on x86-64
and AArch64 architectures.  However, a future release of GCC is expected
to support this as well.

This feature is opt-in for now.  Enabling profile-guided optimization is
highly recommendeded when using the new interpreter as it is the only
configuration that has been tested and validated for improved
performance.  For further information, see *note -with-tail-call-interp:
172.

     Nota: This is not to be confused with tail call optimization(1) of
     Python functions, which is currently not implemented in CPython.

     This new interpreter type is an internal implementation detail of
     the CPython interpreter.  It doesn’t change the visible behavior of
     Python programs at all.  It can improve their performance, but
     doesn’t change anything else.

(Contributed by Ken Jin in gh-128563(2), with ideas on how to implement
this in CPython by Mark Shannon, Garrett Gu, Haoran Xu, and Josh
Haberman.)

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Tail_call

   (2) https://github.com/python/cpython/issues/128563


File: python.info,  Node: Free-threaded mode improvements,  Next: Improved error messages,  Prev: A new type of interpreter,  Up: New features

1.1.2.6 Free-threaded mode improvements
.......................................

CPython’s free-threaded mode ( PEP 703(1)), initially added in 3.13, has
been significantly improved in Python 3.14.  The implementation
described in PEP 703 has been finished, including C API changes, and
temporary workarounds in the interpreter were replaced with more
permanent solutions.  The specializing adaptive interpreter ( PEP
659(2)) is now enabled in free-threaded mode, which along with many
other optimizations greatly improves its performance.  The performance
penalty on single-threaded code in free-threaded mode is now roughly
5-10%, depending on the platform and C compiler used.

From Python 3.14, when compiling extension modules for the free-threaded
build of CPython on Windows, the preprocessor variable ‘Py_GIL_DISABLED’
now needs to be specified by the build backend, as it will no longer be
determined automatically by the C compiler.  For a running interpreter,
the setting that was used at compile time can be found using *note
sysconfig.get_config_var(): 174.

The new *note -X context_aware_warnings: 16f. flag controls if *note
concurrent safe warnings control: 153. is enabled.  The flag defaults to
true for the free-threaded build and false for the GIL-enabled build.

A new *note thread_inherit_context: 175. flag has been added, which if
enabled means that threads created with *note threading.Thread: 176.
start with a copy of the *note Context(): 177. of the caller of *note
start(): 178.  Most significantly, this makes the warning filtering
context established by *note catch_warnings: 179. be «inherited» by
threads (or asyncio tasks) started within that context.  It also affects
other modules that use context variables, such as the *note decimal: 3a.
context manager.  This flag defaults to true for the free-threaded build
and false for the GIL-enabled build.

(Contributed by Sam Gross, Matt Page, Neil Schemenauer, Thomas Wouters,
Donghee Na, Kirill Podoprigora, Ken Jin, Itamar Oren, Brett Simmers,
Dino Viehland, Nathan Goldbaum, Ralf Gommers, Lysandros Nikolaou, Kumar
Aditya, Edgar Margffoy, and many others.  Some of these contributors are
employed by Meta, which has continued to provide significant engineering
resources to support this project.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0703/

   (2) https://peps.python.org/pep-0659/


File: python.info,  Node: Improved error messages,  Next: PEP 784 Zstandard support in the standard library,  Prev: Free-threaded mode improvements,  Up: New features

1.1.2.7 Improved error messages
...............................

   * The interpreter now provides helpful suggestions when it detects
     typos in Python keywords.  When a word that closely resembles a
     Python keyword is encountered, the interpreter will suggest the
     correct keyword in the error message.  This feature helps
     programmers quickly identify and fix common typing mistakes.  For
     example:

          >>> whille True:
          ...     pass
          Traceback (most recent call last):
            File "<stdin>", line 1
              whille True:
              ^^^^^^
          SyntaxError: invalid syntax. Did you mean 'while'?

     While the feature focuses on the most common cases, some variations
     of misspellings may still result in regular syntax errors.
     (Contributed by Pablo Galindo in gh-132449(1).)

   * *note elif: 17b. statements that follow an *note else: 17c. block
     now have a specific error message.  (Contributed by Steele
     Farnsworth in gh-129902(2).)

          >>> if who == "me":
          ...     print("It's me!")
          ... else:
          ...     print("It's not me!")
          ... elif who is None:
          ...     print("Who is it?")
          File "<stdin>", line 5
            elif who is None:
            ^^^^
          SyntaxError: 'elif' block follows an 'else' block

   * If a statement is passed to the *note Conditional expressions: 17d.
     after *note else: 17c, or one of *note pass: 17e, *note break: 17f,
     or *note continue: 180. is passed before *note if: 181, then the
     error message highlights where the *note expression: 182. is
     required.  (Contributed by Sergey Miryanov in gh-129515(3).)

          >>> x = 1 if True else pass
          Traceback (most recent call last):
            File "<string>", line 1
              x = 1 if True else pass
                                 ^^^^
          SyntaxError: expected expression after 'else', but statement is given

          >>> x = continue if True else break
          Traceback (most recent call last):
            File "<string>", line 1
              x = continue if True else break
                  ^^^^^^^^
          SyntaxError: expected expression before 'if', but statement is given

   * When incorrectly closed strings are detected, the error message
     suggests that the string may be intended to be part of the string.
     (Contributed by Pablo Galindo in gh-88535(4).)

          >>> "The interesting object "The important object" is very important"
          Traceback (most recent call last):
          SyntaxError: invalid syntax. Is this intended to be part of the string?

   * When strings have incompatible prefixes, the error now shows which
     prefixes are incompatible.  (Contributed by Nikita Sobolev in
     gh-133197(5).)

          >>> ub'abc'
            File "<python-input-0>", line 1
              ub'abc'
              ^^
          SyntaxError: 'u' and 'b' prefixes are incompatible

   * Improved error messages when using ‘as’ with incompatible targets
     in:

        - Imports: ‘import ... as ...’

        - From imports: ‘from ... import ... as ...’

        - Except handlers: ‘except ... as ...’

        - Pattern-match cases: ‘case ... as ...’

     (Contributed by Nikita Sobolev in gh-123539(6), gh-123562(7), and
     gh-123440(8).)

   * Improved error message when trying to add an instance of an
     unhashable type to a *note dict: 183. or *note set: 184.
     (Contributed by CF Bolz-Tereick and Victor Stinner in
     gh-132828(9).)

          >>> s = set()
          >>> s.add({'pages': 12, 'grade': 'A'})
          Traceback (most recent call last):
            File "<python-input-1>", line 1, in <module>
              s.add({'pages': 12, 'grade': 'A'})
              ~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
          TypeError: cannot use 'dict' as a set element (unhashable type: 'dict')
          >>> d = {}
          >>> l = [1, 2, 3]
          >>> d[l] = 12
          Traceback (most recent call last):
            File "<python-input-4>", line 1, in <module>
              d[l] = 12
              ~^^^
          TypeError: cannot use 'list' as a dict key (unhashable type: 'list')

   * Improved error message when an object supporting the synchronous
     context manager protocol is entered using *note async with: 185.
     instead of *note with: 186, and vice versa for the asynchronous
     context manager protocol.  (Contributed by Bénédikt Tran in
     gh-128398(10).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132449

   (2) https://github.com/python/cpython/issues/129902

   (3) https://github.com/python/cpython/issues/129515

   (4) https://github.com/python/cpython/issues/88535

   (5) https://github.com/python/cpython/issues/133197

   (6) https://github.com/python/cpython/issues/123539

   (7) https://github.com/python/cpython/issues/123562

   (8) https://github.com/python/cpython/issues/123440

   (9) https://github.com/python/cpython/issues/132828

   (10) https://github.com/python/cpython/issues/128398


File: python.info,  Node: PEP 784 Zstandard support in the standard library,  Next: Asyncio introspection capabilities,  Prev: Improved error messages,  Up: New features

'PEP 784': Zstandard support in the standard library

The new ‘compression’ package contains modules ‘compression.lzma’,
‘compression.bz2’, ‘compression.gzip’ and ‘compression.zlib’ which
re-export the *note lzma: 8e, *note bz2: 14, *note gzip: 6b. and *note
zlib: 139. modules respectively.  The new import names under
‘compression’ are the preferred names for importing these compression
modules from Python 3.14.  However, the existing modules names have not
been deprecated.  Any deprecation or removal of the existing compression
modules will occur no sooner than five years after the release of 3.14.

The new ‘compression.zstd’ module provides compression and decompression
APIs for the Zstandard format via bindings to Meta's zstd library(1).
Zstandard is a widely adopted, highly efficient, and fast compression
format.  In addition to the APIs introduced in ‘compression.zstd’,
support for reading and writing Zstandard compressed archives has been
added to the *note tarfile: e4, *note zipfile: 137, and *note shutil:
ca. modules.

Here’s an example of using the new module to compress some data:

     from compression import zstd
     import math

     data = str(math.pi).encode() * 20
     compressed = zstd.compress(data)
     ratio = len(compressed) / len(data)
     print(f"Achieved compression ratio of {ratio}")

As can be seen, the API is similar to the APIs of the ‘lzma’ and ‘bz2’
modules.

(Contributed by Emma Harper Smith, Adam Turner, Gregory P. Smith, Tomas
Roun, Victor Stinner, and Rogdham in gh-132983(2).)

Vedi anche
..........

PEP 784(3).

   ---------- Footnotes ----------

   (1) https://facebook.github.io/zstd/

   (2) https://github.com/python/cpython/issues/132983

   (3) https://peps.python.org/pep-0784/


File: python.info,  Node: Asyncio introspection capabilities,  Next: Concurrent safe warnings control,  Prev: PEP 784 Zstandard support in the standard library,  Up: New features

1.1.2.9 Asyncio introspection capabilities
..........................................

Added a new command-line interface to inspect running Python processes
using asynchronous tasks, available via ‘python -m asyncio ps PID’ or
‘python -m asyncio pstree PID’.

The ‘ps’ subcommand inspects the given process ID (PID) and displays
information about currently running asyncio tasks.  It outputs a task
table: a flat listing of all tasks, their names, their coroutine stacks,
and which tasks are awaiting them.

The ‘pstree’ subcommand fetches the same information, but instead
renders a visual async call tree, showing coroutine relationships in a
hierarchical format.  This command is particularly useful for debugging
long-running or stuck asynchronous programs.  It can help developers
quickly identify where a program is blocked, what tasks are pending, and
how coroutines are chained together.

For example given this code:

     import asyncio

     async def play_track(track):
         await asyncio.sleep(5)
         print(f'🎵 Finished: {track}')

     async def play_album(name, tracks):
         async with asyncio.TaskGroup() as tg:
             for track in tracks:
                 tg.create_task(play_track(track), name=track)

     async def main():
         async with asyncio.TaskGroup() as tg:
             tg.create_task(
               play_album('Sundowning', ['TNDNBTG', 'Levitate']),
               name='Sundowning')
             tg.create_task(
               play_album('TMBTE', ['DYWTYLM', 'Aqua Regia']),
               name='TMBTE')

     if __name__ == '__main__':
         asyncio.run(main())

Executing the new tool on the running process will yield a table like
this:

     python -m asyncio ps 12345

     tid        task id              task name            coroutine stack                                    awaiter chain                                      awaiter name    awaiter id
     ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
     1935500    0x7fc930c18050       Task-1               TaskGroup._aexit -> TaskGroup.__aexit__ -> main                                                                       0x0
     1935500    0x7fc930c18230       Sundowning           TaskGroup._aexit -> TaskGroup.__aexit__ -> album   TaskGroup._aexit -> TaskGroup.__aexit__ -> main    Task-1          0x7fc930c18050
     1935500    0x7fc93173fa50       TMBTE                TaskGroup._aexit -> TaskGroup.__aexit__ -> album   TaskGroup._aexit -> TaskGroup.__aexit__ -> main    Task-1          0x7fc930c18050
     1935500    0x7fc93173fdf0       TNDNBTG              sleep -> play                                      TaskGroup._aexit -> TaskGroup.__aexit__ -> album   Sundowning      0x7fc930c18230
     1935500    0x7fc930d32510       Levitate             sleep -> play                                      TaskGroup._aexit -> TaskGroup.__aexit__ -> album   Sundowning      0x7fc930c18230
     1935500    0x7fc930d32890       DYWTYLM              sleep -> play                                      TaskGroup._aexit -> TaskGroup.__aexit__ -> album   TMBTE           0x7fc93173fa50
     1935500    0x7fc93161ec30       Aqua Regia           sleep -> play                                      TaskGroup._aexit -> TaskGroup.__aexit__ -> album   TMBTE           0x7fc93173fa50

or a tree like this:

     python -m asyncio pstree 12345

     └── (T) Task-1
         └──  main example.py:13
             └──  TaskGroup.__aexit__ Lib/asyncio/taskgroups.py:72
                 └──  TaskGroup._aexit Lib/asyncio/taskgroups.py:121
                     ├── (T) Sundowning
                     │   └──  album example.py:8
                     │       └──  TaskGroup.__aexit__ Lib/asyncio/taskgroups.py:72
                     │           └──  TaskGroup._aexit Lib/asyncio/taskgroups.py:121
                     │               ├── (T) TNDNBTG
                     │               │   └──  play example.py:4
                     │               │       └──  sleep Lib/asyncio/tasks.py:702
                     │               └── (T) Levitate
                     │                   └──  play example.py:4
                     │                       └──  sleep Lib/asyncio/tasks.py:702
                     └── (T) TMBTE
                         └──  album example.py:8
                             └──  TaskGroup.__aexit__ Lib/asyncio/taskgroups.py:72
                                 └──  TaskGroup._aexit Lib/asyncio/taskgroups.py:121
                                     ├── (T) DYWTYLM
                                     │   └──  play example.py:4
                                     │       └──  sleep Lib/asyncio/tasks.py:702
                                     └── (T) Aqua Regia
                                         └──  play example.py:4
                                             └──  sleep Lib/asyncio/tasks.py:702

If a cycle is detected in the async await graph (which could indicate a
programming issue), the tool raises an error and lists the cycle paths
that prevent tree construction:

     python -m asyncio pstree 12345

     ERROR: await-graph contains cycles - cannot print a tree!

     cycle: Task-2 → Task-3 → Task-2

(Contributed by Pablo Galindo, Łukasz Langa, Yury Selivanov, and Marta
Gomez Macias in gh-91048(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91048


File: python.info,  Node: Concurrent safe warnings control,  Prev: Asyncio introspection capabilities,  Up: New features

1.1.2.10 Concurrent safe warnings control
.........................................

The *note warnings.catch_warnings: 179. context manager will now
optionally use a context variable for warning filters.  This is enabled
by setting the *note context_aware_warnings: 18a. flag, either with the
‘-X’ command-line option or an environment variable.  This gives
predictable warnings control when using *note catch_warnings: 179.
combined with multiple threads or asynchronous tasks.  The flag defaults
to true for the free-threaded build and false for the GIL-enabled build.

(Contributed by Neil Schemenauer and Kumar Aditya in gh-130010(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/130010


File: python.info,  Node: Other language changes,  Next: New modules,  Prev: New features,  Up: What’s new in Python 3 14

1.1.3 Other language changes
----------------------------

   * All Windows code pages are now supported as “cpXXX” codecs on
     Windows.  (Contributed by Serhiy Storchaka in gh-123803(1).)

   * Implement mixed-mode arithmetic rules combining real and complex
     numbers as specified by the C standard since C99.  (Contributed by
     Sergey B Kirpichev in gh-69639(2).)

   * More syntax errors are now detected regardless of optimisation and
     the *note -O: 18c. command-line option.  This includes writes to
     ‘__debug__’, incorrect use of *note await: 18d, and asynchronous
     comprehensions outside asynchronous functions.  For example,
     ‘python -O -c 'assert (__debug__ := 1)'’ or ‘python -O -c 'assert
     await 1'’ now produce *note SyntaxError: 18e.s.  (Contributed by
     Irit Katriel and Jelle Zijlstra in gh-122245(3) & gh-121637(4).)

   * When subclassing a pure C type, the C slots for the new type are no
     longer replaced with a wrapped version on class creation if they
     are not explicitly overridden in the subclass.  (Contributed by
     Tomasz Pytel in gh-132284(5).)

* Menu:

* Built-ins::
* Command line and environment::
* PEP 758; Allow except and except* expressions without brackets: PEP 758 Allow except and except* expressions without brackets.
* PEP 765; Control flow in finally blocks: PEP 765 Control flow in finally blocks.
* Incremental garbage collection::
* Default interactive shell::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/123803

   (2) https://github.com/python/cpython/issues/69639

   (3) https://github.com/python/cpython/issues/122245

   (4) https://github.com/python/cpython/issues/121637

   (5) https://github.com/python/cpython/issues/132284


File: python.info,  Node: Built-ins,  Next: Command line and environment,  Up: Other language changes

1.1.3.1 Built-ins
.................

   * The *note bytes.fromhex(): 190. and *note bytearray.fromhex(): 191.
     methods now accept ASCII *note bytes: 192. and *note bytes-like
     objects: 193.  (Contributed by Daniel Pope in gh-129349(1).)

   * Add class methods *note float.from_number(): 194. and *note
     complex.from_number(): 195. to convert a number to *note float:
     196. or *note complex: 197. type correspondingly.  They raise a
     *note TypeError: 198. if the argument is not a real number.
     (Contributed by Serhiy Storchaka in gh-84978(2).)

   * Support underscore and comma as thousands separators in the
     fractional part for floating-point presentation types of the
     new-style string formatting (with *note format(): 199. or *note
     f-strings: 19a.).  (Contributed by Sergey B Kirpichev in
     gh-87790(3).)

   * The *note int(): 19b. function no longer delegates to *note
     __trunc__(): 19c.  Classes that want to support conversion to
     ‘int()’ must implement either *note __int__(): 19d. or *note
     __index__(): 19e.  (Contributed by Mark Dickinson in gh-119743(4).)

   * The *note map(): 19f. function now has an optional keyword-only
     'strict' flag like *note zip(): 1a0. to check that all the
     iterables are of equal length.  (Contributed by Wannes Boeykens in
     gh-119793(5).)

   * The *note memoryview: 165. type now supports subscription, making
     it a *note generic type: 1a1.  (Contributed by Brian Schubert in
     gh-126012(6).)

   * Using *note NotImplemented: 1a2. in a boolean context will now
     raise a *note TypeError: 198.  This has raised a *note
     DeprecationWarning: 1a3. since Python 3.9.  (Contributed by Jelle
     Zijlstra in gh-118767(7).)

   * Three-argument *note pow(): 1a4. now tries calling *note
     __rpow__(): 1a5. if necessary.  Previously it was only called in
     two-argument ‘pow()’ and the binary power operator.  (Contributed
     by Serhiy Storchaka in gh-130104(8).)

   * *note super: 1a6. objects are now *note copyable: 29. and *note
     pickleable: ab.  (Contributed by Serhiy Storchaka in gh-125767(9).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129349

   (2) https://github.com/python/cpython/issues/84978

   (3) https://github.com/python/cpython/issues/87790

   (4) https://github.com/python/cpython/issues/119743

   (5) https://github.com/python/cpython/issues/119793

   (6) https://github.com/python/cpython/issues/126012

   (7) https://github.com/python/cpython/issues/118767

   (8) https://github.com/python/cpython/issues/130104

   (9) https://github.com/python/cpython/issues/125767


File: python.info,  Node: Command line and environment,  Next: PEP 758 Allow except and except* expressions without brackets,  Prev: Built-ins,  Up: Other language changes

1.1.3.2 Command line and environment
....................................

   * The import time flag can now track modules that are already loaded
     (“cached”), via the new *note -X importtime=2: 16f.  When such a
     module is imported, the ‘self’ and ‘cumulative’ times are replaced
     by the string ‘cached’.

     Values above ‘2’ for ‘-X importtime’ are now reserved for future
     use.

     (Contributed by Noah Kim and Adam Turner in gh-118655(1).)

   * The command-line option *note -c: 1a8. now automatically dedents
     its code argument before execution.  The auto-dedentation behavior
     mirrors *note textwrap.dedent(): 1a9.  (Contributed by Jon Crall
     and Steven Sun in gh-103998(2).)

   * ‘-J’ is no longer a reserved flag for Jython(3), and now has no
     special meaning.  (Contributed by Adam Turner in gh-133336(4).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118655

   (2) https://github.com/python/cpython/issues/103998

   (3) https://www.jython.org/

   (4) https://github.com/python/cpython/issues/133336


File: python.info,  Node: PEP 758 Allow except and except* expressions without brackets,  Next: PEP 765 Control flow in finally blocks,  Prev: Command line and environment,  Up: Other language changes

1.1.3.3 PEP 758: Allow ‘except’ and ‘except*’ expressions without brackets
..........................................................................

The *note except: 1ab. and *note except*: 1ac. expressions now allow
brackets to be omitted when there are multiple exception types and the
‘as’ clause is not used.  For example:

     try:
         connect_to_server()
     except TimeoutError, ConnectionRefusedError:
         print('The network has ceased to be!')

(Contributed by Pablo Galindo and Brett Cannon in PEP 758(1) and
gh-131831(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0758/

   (2) https://github.com/python/cpython/issues/131831


File: python.info,  Node: PEP 765 Control flow in finally blocks,  Next: Incremental garbage collection,  Prev: PEP 758 Allow except and except* expressions without brackets,  Up: Other language changes

1.1.3.4 PEP 765: Control flow in ‘finally’ blocks
.................................................

The compiler now emits a *note SyntaxWarning: 1ae. when a *note return:
1af, *note break: 17f, or *note continue: 180. statement have the effect
of leaving a *note finally: 1b0. block.  This change is specified in PEP
765(1).

In situations where this change is inconvenient (such as those where the
warnings are redundant due to code linting), the *note warning filter:
1b1. can be used to turn off all syntax warnings by adding
‘ignore::SyntaxWarning’ as a filter.  This can be specified in
combination with a filter that converts other warnings to errors (for
example, passing ‘-Werror -Wignore::SyntaxWarning’ as CLI options, or
setting ‘PYTHONWARNINGS=error,ignore::SyntaxWarning’).

Note that applying such a filter at runtime using the *note warnings:
118. module will only suppress the warning in code that is compiled
'after' the filter is adjusted.  Code that is compiled prior to the
filter adjustment (for example, when a module is imported) will still
emit the syntax warning.

(Contributed by Irit Katriel in gh-130080(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0765/

   (2) https://github.com/python/cpython/issues/130080


File: python.info,  Node: Incremental garbage collection,  Next: Default interactive shell,  Prev: PEP 765 Control flow in finally blocks,  Up: Other language changes

1.1.3.5 Incremental garbage collection
......................................

The cycle garbage collector is now incremental.  This means that maximum
pause times are reduced by an order of magnitude or more for larger
heaps.

There are now only two generations: young and old.  When *note
gc.collect(): 1b3. is not called directly, the GC is invoked a little
less frequently.  When invoked, it collects the young generation and an
increment of the old generation, instead of collecting one or more
generations.

The behavior of ‘gc.collect()’ changes slightly:

   * ‘gc.collect(1)’: Performs an increment of garbage collection,
     rather than collecting generation 1.

   * Other calls to ‘gc.collect()’ are unchanged.

(Contributed by Mark Shannon in gh-108362(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/108362


File: python.info,  Node: Default interactive shell,  Prev: Incremental garbage collection,  Up: Other language changes

1.1.3.6 Default interactive shell
.................................

   * The default *note interactive: 1b5. shell now highlights Python
     syntax.  The feature is enabled by default, save if *note
     PYTHON_BASIC_REPL: 1b6. or any other environment variable that
     disables colour is set.  See *note Controlling color: 1b7. for
     details.

     The default color theme for syntax highlighting strives for good
     contrast and exclusively uses the 4-bit VGA standard ANSI color
     codes for maximum compatibility.  The theme can be customized using
     an experimental API ‘_colorize.set_theme()’.  This can be called
     interactively or in the *note PYTHONSTARTUP: 1b8. script.  Note
     that this function has no stability guarantees, and may change or
     be removed.

     (Contributed by Łukasz Langa in gh-131507(1).)

   * The default *note interactive: 1b5. shell now supports import
     auto-completion.  This means that typing ‘import co’ and pressing
     ‘<Tab>’ will suggest modules starting with ‘co’.  Similarly, typing
     ‘from concurrent import i’ will suggest submodules of ‘concurrent’
     starting with ‘i’.  Note that autocompletion of module attributes
     is not currently supported.  (Contributed by Tomas Roun in
     gh-69605(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131507

   (2) https://github.com/python/cpython/issues/69605


File: python.info,  Node: New modules,  Next: Improved modules,  Prev: Other language changes,  Up: What’s new in Python 3 14

1.1.4 New modules
-----------------

   * *note annotationlib: 6.: For introspecting *note annotations: 15c.
     See *note PEP 749: 145. for more details.  (Contributed by Jelle
     Zijlstra in gh-119180(1).)

   * *note compression: 22. (including *note compression.zstd: 23.): A
     package for compression-related modules, including a new module to
     support the Zstandard compression format.  See *note PEP 784: 148.
     for more details.  (Contributed by Emma Harper Smith, Adam Turner,
     Gregory P. Smith, Tomas Roun, Victor Stinner, and Rogdham in
     gh-132983(2).)

   * *note concurrent.interpreters: 25.: Support for multiple
     interpreters in the standard library.  See *note PEP 734: 146. for
     more details.  (Contributed by Eric Snow in gh-134939(3).)

   * *note string.templatelib: d9.: Support for template string literals
     (t-strings).  See *note PEP 750: 144. for more details.
     (Contributed by Jim Baker, Guido van Rossum, Paul Everitt, Koudai
     Aono, Lysandros Nikolaou, Dave Peck, Adam Turner, Jelle Zijlstra,
     Bénédikt Tran, and Pablo Galindo Salgado in gh-132661(4).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/119180

   (2) https://github.com/python/cpython/issues/132983

   (3) https://github.com/python/cpython/issues/134939

   (4) https://github.com/python/cpython/issues/132661


File: python.info,  Node: Improved modules,  Next: Optimizations,  Prev: New modules,  Up: What’s new in Python 3 14

1.1.5 Improved modules
----------------------

* Menu:

* argparse::
* ast::
* asyncio::
* calendar::
* concurrent.futures: concurrent futures.
* configparser::
* contextvars::
* ctypes::
* curses::
* datetime::
* decimal::
* difflib::
* dis::
* errno::
* faulthandler::
* fnmatch::
* fractions::
* functools::
* getopt::
* getpass::
* graphlib::
* heapq::
* hmac::
* http::
* imaplib::
* inspect::
* io::
* json::
* linecache::
* logging.handlers: logging handlers.
* math::
* mimetypes::
* multiprocessing::
* operator::
* os::
* os.path: os path.
* pathlib::
* pdb::
* pickle::
* platform::
* pydoc::
* re::
* socket::
* ssl::
* struct::
* symtable::
* sys::
* sys.monitoring: sys monitoring.
* sysconfig::
* tarfile::
* threading::
* tkinter::
* turtle::
* types::
* typing::
* unicodedata::
* unittest::
* urllib::
* uuid::
* webbrowser::
* zipfile::


File: python.info,  Node: argparse,  Next: ast,  Up: Improved modules

1.1.5.1 argparse
................

   * The default value of the *note program name: 1bc. for *note
     argparse.ArgumentParser: 1bd. now reflects the way the Python
     interpreter was instructed to find the ‘__main__’ module code.
     (Contributed by Serhiy Storchaka and Alyssa Coghlan in
     gh-66436(1).)

   * Introduced the optional 'suggest_on_error' parameter to *note
     argparse.ArgumentParser: 1bd, enabling suggestions for argument
     choices and subparser names if mistyped by the user.  (Contributed
     by Savannah Ostrowski in gh-124456(2).)

   * Enable color for help text, which can be disabled with the optional
     'color' parameter to *note argparse.ArgumentParser: 1bd.  This can
     also be controlled by *note environment variables: 1b7.
     (Contributed by Hugo van Kemenade in gh-130645(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/66436

   (2) https://github.com/python/cpython/issues/124456

   (3) https://github.com/python/cpython/issues/130645


File: python.info,  Node: ast,  Next: asyncio,  Prev: argparse,  Up: Improved modules

1.1.5.2 ast
...........

   * Add *note compare(): 1bf, a function for comparing two ASTs.
     (Contributed by Batuhan Taskaya and Jeremy Hylton in gh-60191(1).)

   * Add support for *note copy.replace(): 1c0. for AST nodes.
     (Contributed by Bénédikt Tran in gh-121141(2).)

   * Docstrings are now removed from an optimized AST in optimization
     level 2.  (Contributed by Irit Katriel in gh-123958(3).)

   * The *note repr(): 1c1. output for AST nodes now includes more
     information.  (Contributed by Tomas Roun in gh-116022(4).)

   * When called with an AST as input, the *note parse(): 1c2. function
     now always verifies that the root node type is appropriate.
     (Contributed by Irit Katriel in gh-130139(5).)

   * Add new options to the command-line interface: *note
     -feature-version: 1c3, *note -optimize: 1c4, and *note -show-empty:
     1c5.  (Contributed by Semyon Moroz in gh-133367(6).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/60191

   (2) https://github.com/python/cpython/issues/121141

   (3) https://github.com/python/cpython/issues/123958

   (4) https://github.com/python/cpython/issues/116022

   (5) https://github.com/python/cpython/issues/130139

   (6) https://github.com/python/cpython/issues/133367


File: python.info,  Node: asyncio,  Next: calendar,  Prev: ast,  Up: Improved modules

1.1.5.3 asyncio
...............

   * The function and methods named ‘create_task()’ now take an
     arbitrary list of keyword arguments.  All keyword arguments are
     passed to the *note Task: 1c7. constructor or the custom task
     factory.  (See *note set_task_factory(): 1c8. for details.)  The
     ‘name’ and ‘context’ keyword arguments are no longer special; the
     name should now be set using the ‘name’ keyword argument of the
     factory, and ‘context’ may be ‘None’.

     This affects the following function and methods: *note
     asyncio.create_task(): 1c9, *note asyncio.loop.create_task(): 1ca,
     *note asyncio.TaskGroup.create_task(): 1cb.

     (Contributed by Thomas Grainger in gh-128307(1).)

   * There are two new utility functions for introspecting and printing
     a program’s call graph: *note capture_call_graph(): 1cc. and *note
     print_call_graph(): 1cd.  See *note Asyncio introspection
     capabilities: 147. for more details.  (Contributed by Yury
     Selivanov, Pablo Galindo Salgado, and Łukasz Langa in gh-91048(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128307

   (2) https://github.com/python/cpython/issues/91048


File: python.info,  Node: calendar,  Next: concurrent futures,  Prev: asyncio,  Up: Improved modules

1.1.5.4 calendar
................

   * By default, today’s date is highlighted in color in *note calendar:
     15.’s *note command-line: 1d0. text output.  This can be controlled
     by *note environment variables: 1b7.  (Contributed by Hugo van
     Kemenade in gh-128317(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128317


File: python.info,  Node: concurrent futures,  Next: configparser,  Prev: calendar,  Up: Improved modules

1.1.5.5 concurrent.futures
..........................

   * Add a new executor class, *note InterpreterPoolExecutor: 1d2, which
     exposes multiple Python interpreters in the same process
     (“subinterpreters”) to Python code.  This uses a pool of
     independent Python interpreters to execute calls asynchronously.

     This is separate from the new *note interpreters: 25. module
     introduced by *note PEP 734: 146.  (Contributed by Eric Snow in
     gh-124548(1).)

   * On Unix platforms other than macOS, *note “forkserver”: 1d4. is now
     the default *note start method: 1d5. for *note ProcessPoolExecutor:
     1d6. (replacing *note “fork”: 1d7.).  This change does not affect
     Windows or macOS, where *note “spawn”: 1d8. remains the default
     start method.

     If the threading incompatible 'fork' method is required, you must
     explicitly request it by supplying a multiprocessing context
     'mp_context' to *note ProcessPoolExecutor: 1d6.

     See *note forkserver restrictions: 1d9. for information and
     differences with the 'fork' method and how this change may affect
     existing code with mutable global shared variables and/or shared
     objects that can not be automatically *note pickled: ab.

     (Contributed by Gregory P. Smith in gh-84559(2).)

   * Add two new methods to *note ProcessPoolExecutor: 1d6, *note
     terminate_workers(): 1da. and *note kill_workers(): 1db, as ways to
     terminate or kill all living worker processes in the given pool.
     (Contributed by Charles Machalow in gh-130849(3).)

   * Add the optional 'buffersize' parameter to *note Executor.map: 1dc.
     to limit the number of submitted tasks whose results have not yet
     been yielded.  If the buffer is full, iteration over the
     'iterables' pauses until a result is yielded from the buffer.
     (Contributed by Enzo Bonnal and Josh Rosenberg in gh-74028(4).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/124548

   (2) https://github.com/python/cpython/issues/84559

   (3) https://github.com/python/cpython/issues/130849

   (4) https://github.com/python/cpython/issues/74028


File: python.info,  Node: configparser,  Next: contextvars,  Prev: concurrent futures,  Up: Improved modules

1.1.5.6 configparser
....................

   * ‘configparser’ will no longer write config files it cannot read, to
     improve security.  Attempting to *note write(): 1de. keys
     containing delimiters or beginning with the section header pattern
     will raise an *note InvalidWriteError: 1df.  (Contributed by Jacob
     Lincoln in gh-129270(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129270


File: python.info,  Node: contextvars,  Next: ctypes,  Prev: configparser,  Up: Improved modules

1.1.5.7 contextvars
...................

   * Support the *note context manager: 1e1. protocol for *note Token:
     1e2. objects.  (Contributed by Andrew Svetlov in gh-129889(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129889


File: python.info,  Node: ctypes,  Next: curses,  Prev: contextvars,  Up: Improved modules

1.1.5.8 ctypes
..............

   * The layout of *note bit fields: 1e4. in *note Structure: 1e5. and
     *note Union: 1e6. objects is now a closer match to platform
     defaults (GCC/Clang or MSVC). In particular, fields no longer
     overlap.  (Contributed by Matthias Görgens in gh-97702(1).)

   * The *note Structure._layout_: 1e7. class attribute can now be set
     to help match a non-default ABI. (Contributed by Petr Viktorin in
     gh-97702(2).)

   * The class of *note Structure: 1e5./*note Union: 1e6. field
     descriptors is now available as *note CField: 1e8, and has new
     attributes to aid debugging and introspection.  (Contributed by
     Petr Viktorin in gh-128715(3).)

   * On Windows, the *note COMError: 1e9. exception is now public.
     (Contributed by Jun Komoda in gh-126686(4).)

   * On Windows, the *note CopyComPointer(): 1ea. function is now
     public.  (Contributed by Jun Komoda in gh-127275(5).)

   * Add *note memoryview_at(): 1eb, a function to create a *note
     memoryview: 165. object that refers to the supplied pointer and
     length.  This works like *note ctypes.string_at(): 1ec. except it
     avoids a buffer copy, and is typically useful when implementing
     pure Python callback functions that are passed dynamically-sized
     buffers.  (Contributed by Rian Hunter in gh-112018(6).)

   * Complex types, *note c_float_complex: 1ed, *note c_double_complex:
     1ee, and *note c_longdouble_complex: 1ef, are now available if both
     the compiler and the ‘libffi’ library support complex C types.
     (Contributed by Sergey B Kirpichev in gh-61103(7).)

   * Add *note ctypes.util.dllist(): 1f0. for listing the shared
     libraries loaded by the current process.  (Contributed by Brian
     Ward in gh-119349(8).)

   * Move *note ctypes.POINTER(): 1f1. types cache from a global
     internal cache (‘_pointer_type_cache’) to the *note
     _CData.__pointer_type__: 1f2. attribute of the corresponding
     ‘ctypes’ types.  This will stop the cache from growing without
     limits in some situations.  (Contributed by Sergey Miryanov in
     gh-100926(9).)

   * The *note py_object: 1f3. type now supports subscription, making it
     a *note generic type: 1a1.  (Contributed by Brian Schubert in
     gh-132168(10).)

   * ‘ctypes’ now supports *note free-threading builds: 1f4.
     (Contributed by Kumar Aditya and Peter Bierma in gh-127945(11).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97702

   (2) https://github.com/python/cpython/issues/97702

   (3) https://github.com/python/cpython/issues/128715

   (4) https://github.com/python/cpython/issues/126686

   (5) https://github.com/python/cpython/issues/127275

   (6) https://github.com/python/cpython/issues/112018

   (7) https://github.com/python/cpython/issues/61103

   (8) https://github.com/python/cpython/issues/119349

   (9) https://github.com/python/cpython/issues/100926

   (10) https://github.com/python/cpython/issues/132168

   (11) https://github.com/python/cpython/issues/127945


File: python.info,  Node: curses,  Next: datetime,  Prev: ctypes,  Up: Improved modules

1.1.5.9 curses
..............

   * Add the *note assume_default_colors(): 1f6. function, a refinement
     of the *note use_default_colors(): 1f7. function which allows
     changing the color pair ‘0’.  (Contributed by Serhiy Storchaka in
     gh-133139(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/133139


File: python.info,  Node: datetime,  Next: decimal,  Prev: curses,  Up: Improved modules

1.1.5.10 datetime
.................

   * Add the *note strptime(): 1f9. method to the *note datetime.date:
     1fa. and *note datetime.time: 1fb. classes.  (Contributed by Wannes
     Boeykens in gh-41431(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/41431


File: python.info,  Node: decimal,  Next: difflib,  Prev: datetime,  Up: Improved modules

1.1.5.11 decimal
................

   * Add *note Decimal.from_number(): 1fd. as an alternative constructor
     for *note Decimal: 1fe.  (Contributed by Serhiy Storchaka in
     gh-121798(1).)

   * Expose *note IEEEContext(): 1ff. to support creation of contexts
     corresponding to the IEEE 754 (2008) decimal interchange formats.
     (Contributed by Sergey B Kirpichev in gh-53032(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/121798

   (2) https://github.com/python/cpython/issues/53032


File: python.info,  Node: difflib,  Next: dis,  Prev: decimal,  Up: Improved modules

1.1.5.12 difflib
................

   * Comparison pages with highlighted changes generated by the *note
     HtmlDiff: 201. class now support “dark mode”.  (Contributed by
     Jiahao Li in gh-129939(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129939


File: python.info,  Node: dis,  Next: errno,  Prev: difflib,  Up: Improved modules

1.1.5.13 dis
............

   * Add support for rendering full source location information of *note
     instructions: 203, rather than only the line number.  This feature
     is added to the following interfaces via the 'show_positions'
     keyword argument:

        - *note dis.Bytecode: 204.

        - *note dis.dis(): 205.

        - *note dis.distb(): 206.

        - *note dis.disassemble(): 207.

     This feature is also exposed via *note dis -show-positions: 208.
     (Contributed by Bénédikt Tran in gh-123165(1).)

   * Add the *note dis -specialized: 209. command-line option to show
     specialized bytecode.  (Contributed by Bénédikt Tran in
     gh-127413(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/123165

   (2) https://github.com/python/cpython/issues/127413


File: python.info,  Node: errno,  Next: faulthandler,  Prev: dis,  Up: Improved modules

1.1.5.14 errno
..............

   * Add the *note EHWPOISON: 20b. error code constant.  (Contributed by
     James Roy in gh-126585(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126585


File: python.info,  Node: faulthandler,  Next: fnmatch,  Prev: errno,  Up: Improved modules

1.1.5.15 faulthandler
.....................

   * Add support for printing the C stack trace on systems that *note
     support it: 20d. via the new *note dump_c_stack(): 20e. function or
     via the 'c_stack' argument in *note faulthandler.enable(): 20f.
     (Contributed by Peter Bierma in gh-127604(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127604


File: python.info,  Node: fnmatch,  Next: fractions,  Prev: faulthandler,  Up: Improved modules

1.1.5.16 fnmatch
................

   * Add *note filterfalse(): 211, a function to reject names matching a
     given pattern.  (Contributed by Bénédikt Tran in gh-74598(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/74598


File: python.info,  Node: fractions,  Next: functools,  Prev: fnmatch,  Up: Improved modules

1.1.5.17 fractions
..................

   * A *note Fraction: 213. object may now be constructed from any
     object with the ‘as_integer_ratio()’ method.  (Contributed by
     Serhiy Storchaka in gh-82017(1).)

   * Add *note Fraction.from_number(): 214. as an alternative
     constructor for *note Fraction: 213.  (Contributed by Serhiy
     Storchaka in gh-121797(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/82017

   (2) https://github.com/python/cpython/issues/121797


File: python.info,  Node: functools,  Next: getopt,  Prev: fractions,  Up: Improved modules

1.1.5.18 functools
..................

   * Add the *note Placeholder: 216. sentinel.  This may be used with
     the *note partial(): 217. or *note partialmethod(): 218. functions
     to reserve a place for positional arguments in the returned *note
     partial object: 219.  (Contributed by Dominykas Grigonis in
     gh-119127(1).)

   * Allow the 'initial' parameter of *note reduce(): 21a. to be passed
     as a keyword argument.  (Contributed by Sayandip Dutta in
     gh-125916(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/119127

   (2) https://github.com/python/cpython/issues/125916


File: python.info,  Node: getopt,  Next: getpass,  Prev: functools,  Up: Improved modules

1.1.5.19 getopt
...............

   * Add support for options with optional arguments.  (Contributed by
     Serhiy Storchaka in gh-126374(1).)

   * Add support for returning intermixed options and non-option
     arguments in order.  (Contributed by Serhiy Storchaka in
     gh-126390(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126374

   (2) https://github.com/python/cpython/issues/126390


File: python.info,  Node: getpass,  Next: graphlib,  Prev: getopt,  Up: Improved modules

1.1.5.20 getpass
................

   * Support keyboard feedback in the *note getpass(): 21d. function via
     the keyword-only optional argument 'echo_char'.  Placeholder
     characters are rendered whenever a character is entered, and
     removed when a character is deleted.  (Contributed by Semyon Moroz
     in gh-77065(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/77065


File: python.info,  Node: graphlib,  Next: heapq,  Prev: getpass,  Up: Improved modules

1.1.5.21 graphlib
.................

   * Allow *note TopologicalSorter.prepare(): 21f. to be called more
     than once as long as sorting has not started.  (Contributed by
     Daniel Pope in gh-130914(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/130914


File: python.info,  Node: heapq,  Next: hmac,  Prev: graphlib,  Up: Improved modules

1.1.5.22 heapq
..............

   * The ‘heapq’ module has improved support for working with max-heaps,
     via the following new functions:

        * *note heapify_max(): 221.

        * *note heappush_max(): 222.

        * *note heappop_max(): 223.

        * *note heapreplace_max(): 224.

        * *note heappushpop_max(): 225.


File: python.info,  Node: hmac,  Next: http,  Prev: heapq,  Up: Improved modules

1.1.5.23 hmac
.............

   * Add a built-in implementation for HMAC ( RFC 2104(1)) using
     formally verified code from the HACL*(2) project.  This
     implementation is used as a fallback when the OpenSSL
     implementation of HMAC is not available.  (Contributed by Bénédikt
     Tran in gh-99108(3).)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2104.html

   (2) https://github.com/hacl-star/hacl-star/

   (3) https://github.com/python/cpython/issues/99108


File: python.info,  Node: http,  Next: imaplib,  Prev: hmac,  Up: Improved modules

1.1.5.24 http
.............

   * Directory lists and error pages generated by the *note http.server:
     76. module allow the browser to apply its default dark mode.
     (Contributed by Yorik Hansen in gh-123430(1).)

   * The *note http.server: 76. module now supports serving over HTTPS
     using the *note http.server.HTTPSServer: 228. class.  This
     functionality is exposed by the command-line interface (‘python -m
     http.server’) through the following options:

        * *note -tls-cert <path>: 229.: Path to the TLS certificate
          file.

        * *note -tls-key <path>: 22a.: Optional path to the private key
          file.

        * *note -tls-password-file <path>: 22b.: Optional path to the
          password file for the private key.

     (Contributed by Semyon Moroz in gh-85162(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/123430

   (2) https://github.com/python/cpython/issues/85162


File: python.info,  Node: imaplib,  Next: inspect,  Prev: http,  Up: Improved modules

1.1.5.25 imaplib
................

   * Add *note IMAP4.idle(): 22d, implementing the IMAP4 ‘IDLE’ command
     as defined in RFC 2177(1).  (Contributed by Forest in gh-55454(2).)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2177.html

   (2) https://github.com/python/cpython/issues/55454


File: python.info,  Node: inspect,  Next: io,  Prev: imaplib,  Up: Improved modules

1.1.5.26 inspect
................

   * *note signature(): 22f. takes a new argument 'annotation_format' to
     control the *note annotationlib.Format: 230. used for representing
     annotations.  (Contributed by Jelle Zijlstra in gh-101552(1).)

   * *note Signature.format(): 231. takes a new argument
     'unquote_annotations'.  If true, string *note annotations: 15c. are
     displayed without surrounding quotes.  (Contributed by Jelle
     Zijlstra in gh-101552(2).)

   * Add function *note ispackage(): 232. to determine whether an object
     is a *note package: 233. or not.  (Contributed by Zhikang Yan in
     gh-125634(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101552

   (2) https://github.com/python/cpython/issues/101552

   (3) https://github.com/python/cpython/issues/125634


File: python.info,  Node: io,  Next: json,  Prev: inspect,  Up: Improved modules

1.1.5.27 io
...........

   * Reading text from a non-blocking stream with ‘read’ may now raise a
     *note BlockingIOError: 235. if the operation cannot immediately
     return bytes.  (Contributed by Giovanni Siragusa in gh-109523(1).)

   * Add the *note Reader: 236. and *note Writer: 237. protocols as
     simpler alternatives to the pseudo-protocols *note typing.IO: 238,
     *note typing.TextIO: 239, and *note typing.BinaryIO: 23a.
     (Contributed by Sebastian Rittau in gh-127648(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109523

   (2) https://github.com/python/cpython/issues/127648


File: python.info,  Node: json,  Next: linecache,  Prev: io,  Up: Improved modules

1.1.5.28 json
.............

   * Add exception notes for JSON serialization errors that allow
     identifying the source of the error.  (Contributed by Serhiy
     Storchaka in gh-122163(1).)

   * Allow using the *note json: 86. module as a script using the *note
     -m: 23c. switch: ‘python -m json’.  This is now preferred to
     ‘python -m json.tool’, which is *note soft deprecated: 23d.  See
     the *note JSON command-line interface: 23e. documentation.
     (Contributed by Trey Hunner in gh-122873(2).)

   * By default, the output of the *note JSON command-line interface:
     23e. is highlighted in color.  This can be controlled by *note
     environment variables: 1b7.  (Contributed by Tomas Roun in
     gh-131952(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/122163

   (2) https://github.com/python/cpython/issues/122873

   (3) https://github.com/python/cpython/issues/131952


File: python.info,  Node: linecache,  Next: logging handlers,  Prev: json,  Up: Improved modules

1.1.5.29 linecache
..................

   * *note getline(): 240. can now retrieve source code for frozen
     modules.  (Contributed by Tian Gao in gh-131638(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131638


File: python.info,  Node: logging handlers,  Next: math,  Prev: linecache,  Up: Improved modules

1.1.5.30 logging.handlers
.........................

   * *note QueueListener: 242. objects now support the *note context
     manager: 1e1. protocol.  (Contributed by Charles Machalow in
     gh-132106(1).)

   * *note QueueListener.start: 243. now raises a *note RuntimeError:
     244. if the listener is already started.  (Contributed by Charles
     Machalow in gh-132106(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132106

   (2) https://github.com/python/cpython/issues/132106


File: python.info,  Node: math,  Next: mimetypes,  Prev: logging handlers,  Up: Improved modules

1.1.5.31 math
.............

   * Added more detailed error messages for domain errors in the module.
     (Contributed by Charlie Zhao and Sergey B Kirpichev in
     gh-101410(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101410


File: python.info,  Node: mimetypes,  Next: multiprocessing,  Prev: math,  Up: Improved modules

1.1.5.32 mimetypes
..................

   * Add a public *note command-line: 247. for the module, invoked via
     ‘python -m mimetypes’.  (Contributed by Oleg Iarygin and Hugo van
     Kemenade in gh-93096(1).)

   * Add several new MIME types based on RFCs and common usage:

     Microsoft and
     .............

     RFC 8081(2) MIME types for fonts

        * Embedded OpenType: ‘application/vnd.ms-fontobject’

        * OpenType Layout (OTF) ‘font/otf’

        * TrueType: ‘font/ttf’

        * WOFF 1.0 ‘font/woff’

        * WOFF 2.0 ‘font/woff2’

     RFC 9559(3) MIME types for Matroska audiovisual data container
     structures

        * audio with no video: ‘audio/matroska’ (‘.mka’)

        * video: ‘video/matroska’ (‘.mkv’)

        * stereoscopic video: ‘video/matroska-3d’ (‘.mk3d’)

     Images with RFCs
     ................

        * RFC 1494(4): CCITT Group 3 (‘.g3’)

        * RFC 3362(5): Real-time Facsimile, T.38 (‘.t38’)

        * RFC 3745(6): JPEG 2000 (‘.jp2’), extension (‘.jpx’) and
          compound (‘.jpm’)

        * RFC 3950(7): Tag Image File Format Fax eXtended, TIFF-FX
          (‘.tfx’)

        * RFC 4047(8): Flexible Image Transport System (‘.fits’)

        * RFC 7903(9): Enhanced Metafile (‘.emf’) and Windows Metafile
          (‘.wmf’)

     Other MIME type additions and changes
     .....................................

        * RFC 2361(10): Change type for ‘.avi’ to ‘video/vnd.avi’ and
          for ‘.wav’ to ‘audio/vnd.wave’

        * RFC 4337(11): Add MPEG-4 ‘audio/mp4’ (‘.m4a’)

        * RFC 5334(12): Add Ogg media (‘.oga’, ‘.ogg’ and ‘.ogx’)

        * RFC 6713(13): Add gzip ‘application/gzip’ (‘.gz’)

        * RFC 9639(14): Add FLAC ‘audio/flac’ (‘.flac’)

        * RFC 9512(15) ‘application/yaml’ MIME type for YAML files
          (‘.yaml’ and ‘.yml’)

        * Add 7z ‘application/x-7z-compressed’ (‘.7z’)

        * Add Android Package ‘application/vnd.android.package-archive’
          (‘.apk’) when not strict

        * Add deb ‘application/x-debian-package’ (‘.deb’)

        * Add glTF binary ‘model/gltf-binary’ (‘.glb’)

        * Add glTF JSON/ASCII ‘model/gltf+json’ (‘.gltf’)

        * Add M4V ‘video/x-m4v’ (‘.m4v’)

        * Add PHP ‘application/x-httpd-php’ (‘.php’)

        * Add RAR ‘application/vnd.rar’ (‘.rar’)

        * Add RPM ‘application/x-rpm’ (‘.rpm’)

        * Add STL ‘model/stl’ (‘.stl’)

        * Add Windows Media Video ‘video/x-ms-wmv’ (‘.wmv’)

        * De facto: Add WebM ‘audio/webm’ (‘.weba’)

        * ECMA-376(16): Add ‘.docx’, ‘.pptx’ and ‘.xlsx’ types

        * OASIS(17): Add OpenDocument ‘.odg’, ‘.odp’, ‘.ods’ and ‘.odt’
          types

        * W3C(18): Add EPUB ‘application/epub+zip’ (‘.epub’)

     (Contributed by Sahil Prajapati and Hugo van Kemenade in
     gh-84852(19), by Sasha «Nelie» Chernykh and Hugo van Kemenade in
     gh-132056(20), and by Hugo van Kemenade in gh-89416(21),
     gh-85957(22), and gh-129965(23).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/93096

   (2) https://datatracker.ietf.org/doc/html/rfc8081.html

   (3) https://datatracker.ietf.org/doc/html/rfc9559.html

   (4) https://datatracker.ietf.org/doc/html/rfc1494.html

   (5) https://datatracker.ietf.org/doc/html/rfc3362.html

   (6) https://datatracker.ietf.org/doc/html/rfc3745.html

   (7) https://datatracker.ietf.org/doc/html/rfc3950.html

   (8) https://datatracker.ietf.org/doc/html/rfc4047.html

   (9) https://datatracker.ietf.org/doc/html/rfc7903.html

   (10) https://datatracker.ietf.org/doc/html/rfc2361.html

   (11) https://datatracker.ietf.org/doc/html/rfc4337.html

   (12) https://datatracker.ietf.org/doc/html/rfc5334.html

   (13) https://datatracker.ietf.org/doc/html/rfc6713.html

   (14) https://datatracker.ietf.org/doc/html/rfc9639.html

   (15) https://datatracker.ietf.org/doc/html/rfc9512.html

   (16) 
https://ecma-international.org/publications-and-standards/standards/ecma-376/

   (17) 
https://docs.oasis-open.org/office/v1.2/cs01/OpenDocument-v1.2-cs01-part1.html#Appendix_C

   (18) https://www.w3.org/TR/epub-33/#app-media-type

   (19) https://github.com/python/cpython/issues/84852

   (20) https://github.com/python/cpython/issues/132056

   (21) https://github.com/python/cpython/issues/89416

   (22) https://github.com/python/cpython/issues/85957

   (23) https://github.com/python/cpython/issues/129965


File: python.info,  Node: multiprocessing,  Next: operator,  Prev: mimetypes,  Up: Improved modules

1.1.5.33 multiprocessing
........................

   * On Unix platforms other than macOS, *note “forkserver”: 1d4. is now
     the default *note start method: 1d5. (replacing *note “fork”:
     1d7.).  This change does not affect Windows or macOS, where *note
     “spawn”: 1d8. remains the default start method.

     If the threading incompatible 'fork' method is required, you must
     explicitly request it via a context from *note get_context(): 24a.
     (preferred) or change the default via *note set_start_method():
     24b.

     See *note forkserver restrictions: 1d9. for information and
     differences with the 'fork' method and how this change may affect
     existing code with mutable global shared variables and/or shared
     objects that can not be automatically *note pickled: ab.

     (Contributed by Gregory P. Smith in gh-84559(1).)

   * *note multiprocessing: 98.’s ‘'forkserver'’ start method now
     authenticates its control socket to avoid solely relying on
     filesystem permissions to restrict what other processes could cause
     the forkserver to spawn workers and run code.  (Contributed by
     Gregory P. Smith for gh-97514(2).)

   * The *note multiprocessing proxy objects: 24c. for 'list' and 'dict'
     types gain previously overlooked missing methods:

             * ‘clear()’ and ‘copy()’ for proxies of *note list: 24d.

             * *note fromkeys(): 24e, ‘reversed(d)’, ‘d | {}’, ‘{} | d’,
               ‘d |= {'b': 2}’ for proxies of *note dict: 183.

     (Contributed by Roy Hyunjin Han for gh-103134(3).)

   * Add support for shared *note set: 184. objects via *note
     SyncManager.set(): 24f.  The *note set(): 184. in *note Manager():
     250. method is now available.  (Contributed by Mingyu Park in
     gh-129949(4).)

   * Add the *note interrupt(): 251. to *note multiprocessing.Process:
     252. objects, which terminates the child process by sending *note
     SIGINT: 253.  This enables *note finally: 1b0. clauses to print a
     stack trace for the terminated process.  (Contributed by Artem
     Pulkin in gh-131913(5).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/84559

   (2) https://github.com/python/cpython/issues/97514

   (3) https://github.com/python/cpython/issues/103134

   (4) https://github.com/python/cpython/issues/129949

   (5) https://github.com/python/cpython/issues/131913


File: python.info,  Node: operator,  Next: os,  Prev: multiprocessing,  Up: Improved modules

1.1.5.34 operator
.................

   * Add *note is_none(): 255. and *note is_not_none(): 256. as a pair
     of functions, such that ‘operator.is_none(obj)’ is equivalent to
     ‘obj is None’ and ‘operator.is_not_none(obj)’ is equivalent to ‘obj
     is not None’.  (Contributed by Raymond Hettinger and Nico Mexis in
     gh-115808(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115808


File: python.info,  Node: os,  Next: os path,  Prev: operator,  Up: Improved modules

1.1.5.35 os
...........

   * Add the *note reload_environ(): 258. function to update *note
     os.environ: 259. and *note os.environb: 25a. with changes to the
     environment made by *note os.putenv(): 25b, by *note os.unsetenv():
     25c, or made outside Python in the same process.  (Contributed by
     Victor Stinner in gh-120057(1).)

   * Add the *note SCHED_DEADLINE: 25d. and *note SCHED_NORMAL: 25e.
     constants to the ‘os’ module.  (Contributed by James Roy in
     gh-127688(2).)

   * Add the *note readinto(): 25f. function to read into a *note buffer
     object: 260. from a file descriptor.  (Contributed by Cody Maloney
     in gh-129205(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/120057

   (2) https://github.com/python/cpython/issues/127688

   (3) https://github.com/python/cpython/issues/129205


File: python.info,  Node: os path,  Next: pathlib,  Prev: os,  Up: Improved modules

1.1.5.36 os.path
................

   * The 'strict' parameter to *note realpath(): 262. accepts a new
     value, *note ALLOW_MISSING: 263.  If used, errors other than *note
     FileNotFoundError: 264. will be re-raised; the resulting path can
     be missing but it will be free of symlinks.  (Contributed by Petr
     Viktorin for CVE 2025-4517(1).)

   ---------- Footnotes ----------

   (1) https://www.cve.org/CVERecord?id=CVE-2025-4517


File: python.info,  Node: pathlib,  Next: pdb,  Prev: os path,  Up: Improved modules

1.1.5.37 pathlib
................

   * Add methods to *note pathlib.Path: 266. to recursively copy or move
     files and directories:

        * *note copy(): 267. copies a file or directory tree to a
          destination.

        * *note copy_into(): 268. copies 'into' a destination directory.

        * *note move(): 269. moves a file or directory tree to a
          destination.

        * *note move_into(): 26a. moves 'into' a destination directory.

     (Contributed by Barney Gale in gh-73991(1).)

   * Add the *note info: 26b. attribute, which stores an object
     implementing the new *note pathlib.types.PathInfo: 26c. protocol.
     The object supports querying the file type and internally caching
     *note stat(): 26d. results.  Path objects generated by *note
     iterdir(): 26e. are initialized with file type information gleaned
     from scanning the parent directory.  (Contributed by Barney Gale in
     gh-125413(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/73991

   (2) https://github.com/python/cpython/issues/125413


File: python.info,  Node: pdb,  Next: pickle,  Prev: pathlib,  Up: Improved modules

1.1.5.38 pdb
............

   * The *note pdb: aa. module now supports remote attaching to a
     running Python process using a new *note -p PID: 270. command-line
     option:

          python -m pdb -p 1234

     This will connect to the Python process with the given PID and
     allow you to debug it interactively.  Notice that due to how the
     Python interpreter works attaching to a remote process that is
     blocked in a system call or waiting for I/O will only work once the
     next bytecode instruction is executed or when the process receives
     a signal.

     This feature uses *note PEP 768: 14e. and the new *note
     sys.remote_exec(): 16d. function to attach to the remote process
     and send the PDB commands to it.

     (Contributed by Matt Wozniski and Pablo Galindo in gh-131591(1).)

   * Hardcoded breakpoints (*note breakpoint(): 271. and *note
     set_trace(): 272.) now reuse the most recent *note Pdb: 273.
     instance that calls *note set_trace(): 274, instead of creating a
     new one each time.  As a result, all the instance specific data
     like *note display: 275. and *note commands: 276. are preserved
     across hardcoded breakpoints.  (Contributed by Tian Gao in
     gh-121450(2).)

   * Add a new argument 'mode' to *note pdb.Pdb: 273.  Disable the
     ‘restart’ command when *note pdb: aa. is in ‘inline’ mode.
     (Contributed by Tian Gao in gh-123757(3).)

   * A confirmation prompt will be shown when the user tries to quit
     *note pdb: aa. in ‘inline’ mode.  ‘y’, ‘Y’, ‘<Enter>’ or ‘EOF’ will
     confirm the quit and call *note sys.exit(): 277, instead of raising
     *note bdb.BdbQuit: 278.  (Contributed by Tian Gao in gh-124704(4).)

   * Inline breakpoints like *note breakpoint(): 271. or *note
     pdb.set_trace(): 272. will always stop the program at calling
     frame, ignoring the ‘skip’ pattern (if any).  (Contributed by Tian
     Gao in gh-130493(5).)

   * ‘<tab>’ at the beginning of the line in *note pdb: aa. multi-line
     input will fill in a 4-space indentation now, instead of inserting
     a ‘\t’ character.  (Contributed by Tian Gao in gh-130471(6).)

   * Auto-indent is introduced in *note pdb: aa. multi-line input.  It
     will either keep the indentation of the last line or insert a
     4-space indentation when it detects a new code block.  (Contributed
     by Tian Gao in gh-133350(7).)

   * ‘$_asynctask’ is added to access the current asyncio task if
     applicable.  (Contributed by Tian Gao in gh-124367(8).)

   * *note pdb.set_trace_async(): 279. is added to support debugging
     asyncio coroutines.  *note await: 18d. statements are supported
     with this function.  (Contributed by Tian Gao in gh-132576(9).)

   * Source code displayed in *note pdb: aa. will be syntax-highlighted.
     This feature can be controlled using the same methods as the
     default *note interactive: 1b5. shell, in addition to the newly
     added ‘colorize’ argument of *note pdb.Pdb: 273.  (Contributed by
     Tian Gao and Łukasz Langa in gh-133355(10).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131591

   (2) https://github.com/python/cpython/issues/121450

   (3) https://github.com/python/cpython/issues/123757

   (4) https://github.com/python/cpython/issues/124704

   (5) https://github.com/python/cpython/issues/130493

   (6) https://github.com/python/cpython/issues/130471

   (7) https://github.com/python/cpython/issues/133350

   (8) https://github.com/python/cpython/issues/124367

   (9) https://github.com/python/cpython/issues/132576

   (10) https://github.com/python/cpython/issues/133355


File: python.info,  Node: pickle,  Next: platform,  Prev: pdb,  Up: Improved modules

1.1.5.39 pickle
...............

   * Set the default protocol version on the *note pickle: ab. module to
     5.  For more details, see *note pickle protocols: 27b.

   * Add exception notes for pickle serialization errors that allow
     identifying the source of the error.  (Contributed by Serhiy
     Storchaka in gh-122213(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/122213


File: python.info,  Node: platform,  Next: pydoc,  Prev: pickle,  Up: Improved modules

1.1.5.40 platform
.................

   * Add *note invalidate_caches(): 27d, a function to invalidate cached
     results in the ‘platform’ module.  (Contributed by Bénédikt Tran in
     gh-122549(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/122549


File: python.info,  Node: pydoc,  Next: re,  Prev: platform,  Up: Improved modules

1.1.5.41 pydoc
..............

   * *note Annotations: 15c. in help output are now usually displayed in
     a format closer to that in the original source.  (Contributed by
     Jelle Zijlstra in gh-101552(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101552


File: python.info,  Node: re,  Next: socket,  Prev: pydoc,  Up: Improved modules

1.1.5.42 re
...........

   * Support ‘\z’ as a synonym for ‘\Z’ in *note regular expressions:
     be.  It is interpreted unambiguously in many other regular
     expression engines, unlike ‘\Z’, which has subtly different
     behavior.  (Contributed by Serhiy Storchaka in gh-133306(1).)

   * ‘\B’ in *note regular expression: be. now matches the empty input
     string, meaning that it is now always the opposite of ‘\b’.
     (Contributed by Serhiy Storchaka in gh-124130(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/133306

   (2) https://github.com/python/cpython/issues/124130


File: python.info,  Node: socket,  Next: ssl,  Prev: re,  Up: Improved modules

1.1.5.43 socket
...............

   * Improve and fix support for Bluetooth sockets.

        * Fix support of Bluetooth sockets on NetBSD and DragonFly BSD.
          (Contributed by Serhiy Storchaka in gh-132429(1).)

        * Fix support for *note BTPROTO_HCI: 281. on FreeBSD.
          (Contributed by Victor Stinner in gh-111178(2).)

        * Add support for *note BTPROTO_SCO: 282. on FreeBSD.
          (Contributed by Serhiy Storchaka in gh-85302(3).)

        * Add support for 'cid' and 'bdaddr_type' in the address for
          *note BTPROTO_L2CAP: 283. on FreeBSD. (Contributed by Serhiy
          Storchaka in gh-132429(4).)

        * Add support for 'channel' in the address for *note
          BTPROTO_HCI: 281. on Linux.  (Contributed by Serhiy Storchaka
          in gh-70145(5).)

        * Accept an integer as the address for *note BTPROTO_HCI: 281.
          on Linux.  (Contributed by Serhiy Storchaka in gh-132099(6).)

        * Return 'cid' in *note getsockname(): 284. for *note
          BTPROTO_L2CAP: 283.  (Contributed by Serhiy Storchaka in
          gh-132429(7).)

        * Add many new constants.  (Contributed by Serhiy Storchaka in
          gh-132734(8).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132429

   (2) https://github.com/python/cpython/issues/111178

   (3) https://github.com/python/cpython/issues/85302

   (4) https://github.com/python/cpython/issues/132429

   (5) https://github.com/python/cpython/issues/70145

   (6) https://github.com/python/cpython/issues/132099

   (7) https://github.com/python/cpython/issues/132429

   (8) https://github.com/python/cpython/issues/132734


File: python.info,  Node: ssl,  Next: struct,  Prev: socket,  Up: Improved modules

1.1.5.44 ssl
............

   * Indicate through the *note HAS_PHA: 286. Boolean whether the ‘ssl’
     module supports TLSv1.3 post-handshake client authentication (PHA).
     (Contributed by Will Childs-Klein in gh-128036(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128036


File: python.info,  Node: struct,  Next: symtable,  Prev: ssl,  Up: Improved modules

1.1.5.45 struct
...............

   * Support the float complex and double complex C types in the *note
     struct: db. module (formatting characters ‘'F'’ and ‘'D'’
     respectively).  (Contributed by Sergey B Kirpichev in
     gh-121249(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/121249


File: python.info,  Node: symtable,  Next: sys,  Prev: struct,  Up: Improved modules

1.1.5.46 symtable
.................

   * Expose the following *note Symbol: 289. methods:

        * *note is_comp_cell(): 28a.

        * *note is_comp_iter(): 28b.

        * *note is_free_class(): 28c.

     (Contributed by Bénédikt Tran in gh-120029(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/120029


File: python.info,  Node: sys,  Next: sys monitoring,  Prev: symtable,  Up: Improved modules

1.1.5.47 sys
............

   * The previously undocumented special function *note
     sys.getobjects(): 28e, which only exists in specialized builds of
     Python, may now return objects from other interpreters than the one
     it’s called in.  (Contributed by Eric Snow in gh-125286(1).)

   * Add *note sys._is_immortal(): 28f. for determining if an object is
     *note immortal: 290.  (Contributed by Peter Bierma in
     gh-128509(2).)

   * On FreeBSD, *note sys.platform: 291. no longer contains the major
     version number.  It is always ‘'freebsd'’, instead of ‘'freebsd13'’
     or ‘'freebsd14'’.  (Contributed by Michael Osipov in gh-129393(3).)

   * Raise *note DeprecationWarning: 1a3. for *note
     sys._clear_type_cache(): 292.  This function was deprecated in
     Python 3.13 but it didn’t raise a runtime warning.

   * Add *note sys.remote_exec(): 16d. to implement the new external
     debugger interface.  See *note PEP 768: 14e. for details.
     (Contributed by Pablo Galindo Salgado, Matt Wozniski, and Ivona
     Stojanovic in gh-131591(4).)

   * Add the *note sys._jit: 293. namespace, containing utilities for
     introspecting just-in-time compilation.  (Contributed by Brandt
     Bucher in gh-133231(5).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/125286

   (2) https://github.com/python/cpython/issues/128509

   (3) https://github.com/python/cpython/issues/129393

   (4) https://github.com/python/cpython/issues/131591

   (5) https://github.com/python/cpython/issues/133231


File: python.info,  Node: sys monitoring,  Next: sysconfig,  Prev: sys,  Up: Improved modules

1.1.5.48 sys.monitoring
.......................

   * Add two new monitoring events, *note BRANCH_LEFT: 295. and *note
     BRANCH_RIGHT: 296.  These replace and deprecate the ‘BRANCH’ event.
     (Contributed by Mark Shannon in gh-122548(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/122548


File: python.info,  Node: sysconfig,  Next: tarfile,  Prev: sys monitoring,  Up: Improved modules

1.1.5.49 sysconfig
..................

   * Add ‘ABIFLAGS’ key to *note get_config_vars(): 298. on Windows.
     (Contributed by Xuehai Pan in gh-131799(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131799


File: python.info,  Node: tarfile,  Next: threading,  Prev: sysconfig,  Up: Improved modules

1.1.5.50 tarfile
................

   * *note data_filter(): 29a. now normalizes symbolic link targets in
     order to avoid path traversal attacks.  (Contributed by Petr
     Viktorin in gh-127987(1) and CVE 2025-4138(2).)

   * *note extractall(): 29b. now skips fixing up directory attributes
     when a directory was removed or replaced by another kind of file.
     (Contributed by Petr Viktorin in gh-127987(3) and CVE
     2024-12718(4).)

   * *note extract(): 29c. and *note extractall(): 29b. now (re-)apply
     the extraction filter when substituting a link (hard or symbolic)
     with a copy of another archive member, and when fixing up directory
     attributes.  The former raises a new exception, *note
     LinkFallbackError: 29d.  (Contributed by Petr Viktorin for CVE
     2025-4330(5) and CVE 2024-12718(6).)

   * *note extract(): 29c. and *note extractall(): 29b. no longer
     extract rejected members when *note errorlevel(): 29e. is zero.
     (Contributed by Matt Prodani and Petr Viktorin in gh-112887(7) and
     CVE 2025-4435(8).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127987

   (2) https://www.cve.org/CVERecord?id=CVE-2025-4138

   (3) https://github.com/python/cpython/issues/127987

   (4) https://www.cve.org/CVERecord?id=CVE-2024-12718

   (5) https://www.cve.org/CVERecord?id=CVE-2025-4330

   (6) https://www.cve.org/CVERecord?id=CVE-2024-12718

   (7) https://github.com/python/cpython/issues/112887

   (8) https://www.cve.org/CVERecord?id=CVE-2025-4435


File: python.info,  Node: threading,  Next: tkinter,  Prev: tarfile,  Up: Improved modules

1.1.5.51 threading
..................

   * *note threading.Thread.start(): 178. now sets the operating system
     thread name to *note threading.Thread.name: 2a0.  (Contributed by
     Victor Stinner in gh-59705(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/59705


File: python.info,  Node: tkinter,  Next: turtle,  Prev: threading,  Up: Improved modules

1.1.5.52 tkinter
................

   * Make *note tkinter: f6. widget methods ‘after()’ and ‘after_idle()’
     accept keyword arguments.  (Contributed by Zhikang Yan in
     gh-126899(1).)

   * Add ability to specify a name for ‘tkinter.OptionMenu’ and
     ‘tkinter.ttk.OptionMenu’.  (Contributed by Zhikang Yan in
     gh-130482(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126899

   (2) https://github.com/python/cpython/issues/130482


File: python.info,  Node: turtle,  Next: types,  Prev: tkinter,  Up: Improved modules

1.1.5.53 turtle
...............

   * Add context managers for *note turtle.fill(): 2a3, *note
     turtle.poly(): 2a4, and *note turtle.no_animation(): 2a5.
     (Contributed by Marie Roald and Yngve Mardal Moe in gh-126350(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126350


File: python.info,  Node: types,  Next: typing,  Prev: turtle,  Up: Improved modules

1.1.5.54 types
..............

   * *note types.UnionType: 2a7. is now an alias for *note typing.Union:
     2a8.  See *note below: 2a9. for more details.  (Contributed by
     Jelle Zijlstra in gh-105499(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/105499


File: python.info,  Node: typing,  Next: unicodedata,  Prev: types,  Up: Improved modules

1.1.5.55 typing
...............

   * The *note types.UnionType: 2a7. and *note typing.Union: 2a8. types
     are now aliases for each other, meaning that both old-style unions
     (created with ‘Union[int, str]’) and new-style unions (‘int | str’)
     now create instances of the same runtime type.  This unifies the
     behavior between the two syntaxes, but leads to some differences in
     behavior that may affect users who introspect types at runtime:

        - Both syntaxes for creating a union now produce the same string
          representation in *note repr(): 1c1.  For example,
          ‘repr(Union[int, str])’ is now ‘"int | str"’ instead of
          ‘"typing.Union[int, str]"’.

        - Unions created using the old syntax are no longer cached.
          Previously, running ‘Union[int, str]’ multiple times would
          return the same object (‘Union[int, str] is Union[int, str]’
          would be ‘True’), but now it will return two different
          objects.  Use ‘==’ to compare unions for equality, not ‘is’.
          New-style unions have never been cached this way.  This change
          could increase memory usage for some programs that use a large
          number of unions created by subscripting ‘typing.Union’.
          However, several factors offset this cost: unions used in
          annotations are no longer evaluated by default in Python 3.14
          because of PEP 649(1); an instance of *note types.UnionType:
          2a7. is itself much smaller than the object returned by
          ‘Union[]’ was on prior Python versions; and removing the cache
          also saves some space.  It is therefore unlikely that this
          change will cause a significant increase in memory usage for
          most users.

        - Previously, old-style unions were implemented using the
          private class ‘typing._UnionGenericAlias’.  This class is no
          longer needed for the implementation, but it has been retained
          for backward compatibility, with removal scheduled for Python
          3.17.  Users should use documented introspection helpers like
          *note get_origin(): 2ab. and *note typing.get_args(): 2ac.
          instead of relying on private implementation details.

        - It is now possible to use *note typing.Union: 2a8. itself in
          *note isinstance(): 2ad. checks.  For example, ‘isinstance(int
          | str, typing.Union)’ will return ‘True’; previously this
          raised *note TypeError: 198.

        - The ‘__args__’ attribute of *note typing.Union: 2a8. objects
          is no longer writable.

        - It is no longer possible to set any attributes on *note Union:
          2a8. objects.  This only ever worked for dunder attributes on
          previous versions, was never documented to work, and was
          subtly broken in many cases.

     (Contributed by Jelle Zijlstra in gh-105499(2).)

   * *note TypeAliasType: 2ae. now supports star unpacking.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0649/

   (2) https://github.com/python/cpython/issues/105499


File: python.info,  Node: unicodedata,  Next: unittest,  Prev: typing,  Up: Improved modules

1.1.5.56 unicodedata
....................

   * The Unicode database has been updated to Unicode 16.0.0.


File: python.info,  Node: unittest,  Next: urllib,  Prev: unicodedata,  Up: Improved modules

1.1.5.57 unittest
.................

   * *note unittest: 10c. output is now colored by default.  This can be
     controlled by *note environment variables: 1b7.  (Contributed by
     Hugo van Kemenade in gh-127221(1).)

   * unittest discovery supports *note namespace package: 2b2. as start
     directory again.  It was removed in Python 3.11.  (Contributed by
     Jacob Walls in gh-80958(2).)

   * A number of new methods were added in the *note TestCase: 2b3.
     class that provide more specialized tests.

        - *note assertHasAttr(): 2b4. and *note assertNotHasAttr(): 2b5.
          check whether the object has a particular attribute.

        - *note assertIsSubclass(): 2b6. and *note
          assertNotIsSubclass(): 2b7. check whether the object is a
          subclass of a particular class, or of one of a tuple of
          classes.

        - *note assertStartsWith(): 2b8, *note assertNotStartsWith():
          2b9, *note assertEndsWith(): 2ba. and *note
          assertNotEndsWith(): 2bb. check whether the Unicode or byte
          string starts or ends with particular strings.

     (Contributed by Serhiy Storchaka in gh-71339(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127221

   (2) https://github.com/python/cpython/issues/80958

   (3) https://github.com/python/cpython/issues/71339


File: python.info,  Node: urllib,  Next: uuid,  Prev: unittest,  Up: Improved modules

1.1.5.58 urllib
...............

   * Upgrade HTTP digest authentication algorithm for *note
     urllib.request: 111. by supporting SHA-256 digest authentication as
     specified in RFC 7616(1).  (Contributed by Calvin Bui in
     gh-128193(2).)

   * Improve ergonomics and standards compliance when parsing and
     emitting ‘file:’ URLs.

     In *note url2pathname(): 2bd.:

        - Accept a complete URL when the new 'require_scheme' argument
          is set to true.

        - Discard URL authority if it matches the local hostname.

        - Discard URL authority if it resolves to a local IP address
          when the new 'resolve_host' argument is set to true.

        - Discard URL query and fragment components.

        - Raise *note URLError: 2be. if a URL authority isn’t local,
          except on Windows where we return a UNC path as before.

     In *note pathname2url(): 2bf.:

        - Return a complete URL when the new 'add_scheme' argument is
          set to true.

        - Include an empty URL authority when a path begins with a
          slash.  For example, the path ‘/etc/hosts’ is converted to the
          URL ‘///etc/hosts’.

     On Windows, drive letters are no longer converted to uppercase, and
     ‘:’ characters not following a drive letter no longer cause an
     *note OSError: 2c0. exception to be raised.

     (Contributed by Barney Gale in gh-125866(3).)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc7616.html

   (2) https://github.com/python/cpython/issues/128193

   (3) https://github.com/python/cpython/issues/125866


File: python.info,  Node: uuid,  Next: webbrowser,  Prev: urllib,  Up: Improved modules

1.1.5.59 uuid
.............

   * Add support for UUID versions 6, 7, and 8 via *note uuid6(): 2c2,
     *note uuid7(): 2c3, and *note uuid8(): 2c4. respectively, as
     specified in RFC 9562(1).  (Contributed by Bénédikt Tran in
     gh-89083(2).)

   * *note NIL: 2c5. and *note MAX: 2c6. are now available to represent
     the Nil and Max UUID formats as defined by RFC 9562(3).
     (Contributed by Nick Pope in gh-128427(4).)

   * Allow generating multiple UUIDs simultaneously on the command-line
     via *note python -m uuid -count: 2c7.  (Contributed by Simon Legner
     in gh-131236(5).)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc9562.html

   (2) https://github.com/python/cpython/issues/89083

   (3) https://datatracker.ietf.org/doc/html/rfc9562.html

   (4) https://github.com/python/cpython/issues/128427

   (5) https://github.com/python/cpython/issues/131236


File: python.info,  Node: webbrowser,  Next: zipfile,  Prev: uuid,  Up: Improved modules

1.1.5.60 webbrowser
...................

   * Names in the ‘BROWSER’ environment variable can now refer to
     already registered browsers for the *note webbrowser: 11b. module,
     instead of always generating a new browser command.

     This makes it possible to set ‘BROWSER’ to the value of one of the
     supported browsers on macOS.


File: python.info,  Node: zipfile,  Prev: webbrowser,  Up: Improved modules

1.1.5.61 zipfile
................

   * Added *note ZipInfo._for_archive: 2ca, a method to resolve suitable
     defaults for a *note ZipInfo: 2cb. object as used by *note
     ZipFile.writestr: 2cc.  (Contributed by Bénédikt Tran in
     gh-123424(1).)

   * *note ZipFile.writestr(): 2cc. now respects the ‘SOURCE_DATE_EPOCH’
     environment variable in order to better support reproducible
     builds.  (Contributed by Jiahao Li in gh-91279(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/123424

   (2) https://github.com/python/cpython/issues/91279


File: python.info,  Node: Optimizations,  Next: Removed,  Prev: Improved modules,  Up: What’s new in Python 3 14

1.1.6 Optimizations
-------------------

   * The import time for several standard library modules has been
     improved, including *note annotationlib: 6, *note ast: 9, *note
     asyncio: b, *note base64: f, *note cmd: 1a, *note csv: 2d, *note
     gettext: 67, *note importlib.util: 81, *note locale: 8a, *note
     mimetypes: 93, *note optparse: a4, *note pickle: ab, *note pprint:
     b3, *note pstats: b5, *note shlex: c9, *note socket: d1, *note
     string: d8, *note subprocess: dc, *note threading: f3, *note
     tomllib: 102, *note types: 109, and *note zipfile: 137.

     (Contributed by Adam Turner, Bénédikt Tran, Chris Markiewicz, Eli
     Schwartz, Hugo van Kemenade, Jelle Zijlstra, and others in
     gh-118761(1).)

   * The interpreter now avoids some reference count modifications
     internally when it’s safe to do so.  This can lead to different
     values being returned from *note sys.getrefcount(): 2ce. and *note
     Py_REFCNT(): 2cf. compared to previous versions of Python.  See
     *note below: 2d0. for details.

* Menu:

* asyncio: asyncio<2>.
* base64::
* bdb::
* difflib: difflib<2>.
* gc::
* io: io<2>.
* pathlib: pathlib<2>.
* pdb: pdb<2>.
* textwrap::
* uuid: uuid<2>.
* zlib::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118761


File: python.info,  Node: asyncio<2>,  Next: base64,  Up: Optimizations

1.1.6.1 asyncio
...............

   * Standard benchmark results have improved by 10-20% following the
     implementation of a new per-thread doubly linked list for *note
     native tasks: 1c7, also reducing memory usage.  This enables
     external introspection tools such as *note python -m asyncio
     pstree: 147. to introspect the call graph of asyncio tasks running
     in all threads.  (Contributed by Kumar Aditya in gh-107803(1).)

   * The module now has first class support for *note free-threading
     builds: 1f4.  This enables parallel execution of multiple event
     loops across different threads, scaling linearly with the number of
     threads.  (Contributed by Kumar Aditya in gh-128002(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/107803

   (2) https://github.com/python/cpython/issues/128002


File: python.info,  Node: base64,  Next: bdb,  Prev: asyncio<2>,  Up: Optimizations

1.1.6.2 base64
..............

   * *note b16decode(): 2d3. is now up to six times faster.
     (Contributed by Bénédikt Tran, Chris Markiewicz, and Adam Turner in
     gh-118761(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118761


File: python.info,  Node: bdb,  Next: difflib<2>,  Prev: base64,  Up: Optimizations

1.1.6.3 bdb
...........

   * The basic debugger now has a *note sys.monitoring: e0.-based
     backend, which can be selected via the passing ‘'monitoring'’ to
     the *note Bdb: 2d5. class’s new 'backend' parameter.  (Contributed
     by Tian Gao in gh-124533(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/124533


File: python.info,  Node: difflib<2>,  Next: gc,  Prev: bdb,  Up: Optimizations

1.1.6.4 difflib
...............

   * The *note IS_LINE_JUNK(): 2d7. function is now up to twice as fast.
     (Contributed by Adam Turner and Semyon Moroz in gh-130167(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/130167


File: python.info,  Node: gc,  Next: io<2>,  Prev: difflib<2>,  Up: Optimizations

1.1.6.5 gc
..........

   * The new *note incremental garbage collector: 152. means that
     maximum pause times are reduced by an order of magnitude or more
     for larger heaps.

     Because of this optimization, the meaning of the results of *note
     get_threshold(): 2d9. and *note set_threshold(): 2da. have changed,
     along with *note get_count(): 2db. and *note get_stats(): 2dc.

        - For backwards compatibility, *note get_threshold(): 2d9.
          continues to return a three-item tuple.  The first value is
          the threshold for young collections, as before; the second
          value determines the rate at which the old collection is
          scanned (the default is 10, and higher values mean that the
          old collection is scanned more slowly).  The third value is
          now meaningless and is always zero.

        - *note set_threshold(): 2da. now ignores any items after the
          second.

        - *note get_count(): 2db. and *note get_stats(): 2dc. continue
          to return the same format of results.  The only difference is
          that instead of the results referring to the young, aging and
          old generations, the results refer to the young generation and
          the aging and collecting spaces of the old generation.

     In summary, code that attempted to manipulate the behavior of the
     cycle GC may not work exactly as intended, but it is very unlikely
     to be harmful.  All other code will work just fine.

     (Contributed by Mark Shannon in gh-108362(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/108362


File: python.info,  Node: io<2>,  Next: pathlib<2>,  Prev: gc,  Up: Optimizations

1.1.6.6 io
..........

   * Opening and reading files now executes fewer system calls.  Reading
     a small operating system cached file in full is up to 15% faster.
     (Contributed by Cody Maloney and Victor Stinner in gh-120754(1) and
     gh-90102(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/120754

   (2) https://github.com/python/cpython/issues/90102


File: python.info,  Node: pathlib<2>,  Next: pdb<2>,  Prev: io<2>,  Up: Optimizations

1.1.6.7 pathlib
...............

   * *note Path.read_bytes: 2df. now uses unbuffered mode to open files,
     which is between 9% and 17% faster to read in full.  (Contributed
     by Cody Maloney in gh-120754(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/120754


File: python.info,  Node: pdb<2>,  Next: textwrap,  Prev: pathlib<2>,  Up: Optimizations

1.1.6.8 pdb
...........

   * *note pdb: aa. now supports two backends, based on either *note
     sys.settrace(): 2e1. or *note sys.monitoring: e0.  Using the *note
     pdb CLI: 2e2. or *note breakpoint(): 271. will always use the *note
     sys.monitoring: e0. backend.  Explicitly instantiating *note
     pdb.Pdb: 273. and its derived classes will use the *note
     sys.settrace(): 2e1. backend by default, which is configurable.
     (Contributed by Tian Gao in gh-124533(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/124533


File: python.info,  Node: textwrap,  Next: uuid<2>,  Prev: pdb<2>,  Up: Optimizations

1.1.6.9 textwrap
................

   * Optimize the *note dedent(): 1a9. function, improving performance
     by an average of 2.4x, with larger improvements for bigger inputs,
     and fix a bug with incomplete normalization of blank lines with
     whitespace characters other than space and tab.


File: python.info,  Node: uuid<2>,  Next: zlib,  Prev: textwrap,  Up: Optimizations

1.1.6.10 uuid
.............

   * *note uuid3(): 2e5. and *note uuid5(): 2e6. are now both roughly
     40% faster for 16-byte names and 20% faster for 1024-byte names.
     Performance for longer names remains unchanged.  (Contributed by
     Bénédikt Tran in gh-128150(1).)

   * *note uuid4(): 2e7. is now c.  30% faster.  (Contributed by
     Bénédikt Tran in gh-128150(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128150

   (2) https://github.com/python/cpython/issues/128150


File: python.info,  Node: zlib,  Prev: uuid<2>,  Up: Optimizations

1.1.6.11 zlib
.............

   * On Windows, zlib-ng(1) is now used as the implementation of the
     *note zlib: 139. module in the default binaries.  There are no
     known incompatibilities between ‘zlib-ng’ and the previously-used
     ‘zlib’ implementation.  This should result in better performance at
     all compression levels.

     It is worth noting that ‘zlib.Z_BEST_SPEED’ (‘1’) may result in
     significantly less compression than the previous implementation,
     whilst also significantly reducing the time taken to compress.

     (Contributed by Steve Dower in gh-91349(2).)

   ---------- Footnotes ----------

   (1) https://github.com/zlib-ng/zlib-ng

   (2) https://github.com/python/cpython/issues/91349


File: python.info,  Node: Removed,  Next: Deprecated,  Prev: Optimizations,  Up: What’s new in Python 3 14

1.1.7 Removed
-------------

* Menu:

* argparse: argparse<2>.
* ast: ast<2>.
* asyncio: asyncio<3>.
* email::
* importlib.abc: importlib abc.
* itertools::
* pathlib: pathlib<3>.
* pkgutil::
* pty::
* sqlite3::
* urllib: urllib<2>.


File: python.info,  Node: argparse<2>,  Next: ast<2>,  Up: Removed

1.1.7.1 argparse
................

   * Remove the 'type', 'choices', and 'metavar' parameters of
     ‘BooleanOptionalAction’.  These have been deprecated since Python
     3.12.  (Contributed by Nikita Sobolev in gh-118805(1).)

   * Calling *note add_argument_group(): 2eb. on an argument group now
     raises a *note ValueError: 2ec.  Similarly, *note
     add_argument_group(): 2eb. or *note add_mutually_exclusive_group():
     2ed. on a mutually exclusive group now both raise *note ValueError:
     2ec.s.  This “nesting” was never supported, often failed to work
     correctly, and was unintentionally exposed through inheritance.
     This functionality has been deprecated since Python 3.11.
     (Contributed by Savannah Ostrowski in gh-127186(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118805

   (2) https://github.com/python/cpython/issues/127186


File: python.info,  Node: ast<2>,  Next: asyncio<3>,  Prev: argparse<2>,  Up: Removed

1.1.7.2 ast
...........

   * Remove the following classes, which have been deprecated aliases of
     *note Constant: 2ef. since Python 3.8 and have emitted deprecation
     warnings since Python 3.12:

        * ‘Bytes’

        * ‘Ellipsis’

        * ‘NameConstant’

        * ‘Num’

        * ‘Str’

     As a consequence of these removals, user-defined ‘visit_Num’,
     ‘visit_Str’, ‘visit_Bytes’, ‘visit_NameConstant’ and
     ‘visit_Ellipsis’ methods on custom *note NodeVisitor: 2f0.
     subclasses will no longer be called when the ‘NodeVisitor’ subclass
     is visiting an AST. Define a ‘visit_Constant’ method instead.

     (Contributed by Alex Waygood in gh-119562(1).)

   * Remove the following deprecated properties on *note ast.Constant:
     2ef, which were present for compatibility with the now-removed AST
     classes:

        * ‘Constant.n’

        * ‘Constant.s’

     Use ‘Constant.value’ instead.  (Contributed by Alex Waygood in
     gh-119562(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/119562

   (2) https://github.com/python/cpython/issues/119562


File: python.info,  Node: asyncio<3>,  Next: email,  Prev: ast<2>,  Up: Removed

1.1.7.3 asyncio
...............

   * Remove the following classes, methods, and functions, which have
     been deprecated since Python 3.12:

        * ‘AbstractChildWatcher’

        * ‘FastChildWatcher’

        * ‘MultiLoopChildWatcher’

        * ‘PidfdChildWatcher’

        * ‘SafeChildWatcher’

        * ‘ThreadedChildWatcher’

        * ‘AbstractEventLoopPolicy.get_child_watcher()’

        * ‘AbstractEventLoopPolicy.set_child_watcher()’

        * ‘get_child_watcher()’

        * ‘set_child_watcher()’

     (Contributed by Kumar Aditya in gh-120804(1).)

   * *note asyncio.get_event_loop(): 2f2. now raises a *note
     RuntimeError: 244. if there is no current event loop, and no longer
     implicitly creates an event loop.

     (Contributed by Kumar Aditya in gh-126353(2).)

     There’s a few patterns that use *note asyncio.get_event_loop():
     2f2, most of them can be replaced with *note asyncio.run(): 2f3.

     If you’re running an async function, simply use *note
     asyncio.run(): 2f3.

     Before:

          async def main():
              ...


          loop = asyncio.get_event_loop()
          try:
              loop.run_until_complete(main())
          finally:
              loop.close()

     After:

          async def main():
              ...

          asyncio.run(main())

     If you need to start something, for example, a server listening on
     a socket and then run forever, use *note asyncio.run(): 2f3. and an
     *note asyncio.Event: 2f4.

     Before:

          def start_server(loop): ...

          loop = asyncio.get_event_loop()
          try:
              start_server(loop)
              loop.run_forever()
          finally:
              loop.close()

     After:

          def start_server(loop): ...

          async def main():
              start_server(asyncio.get_running_loop())
              await asyncio.Event().wait()

          asyncio.run(main())

     If you need to run something in an event loop, then run some
     blocking code around it, use *note asyncio.Runner: 2f5.

     Before:

          async def operation_one(): ...
          def blocking_code(): ...
          async def operation_two(): ...

          loop = asyncio.get_event_loop()
          try:
              loop.run_until_complete(operation_one())
              blocking_code()
              loop.run_until_complete(operation_two())
          finally:
              loop.close()

     After:

          async def operation_one(): ...
          def blocking_code(): ...
          async def operation_two(): ...

          with asyncio.Runner() as runner:
              runner.run(operation_one())
              blocking_code()
              runner.run(operation_two())

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/120804

   (2) https://github.com/python/cpython/issues/126353


File: python.info,  Node: email,  Next: importlib abc,  Prev: asyncio<3>,  Up: Removed

1.1.7.4 email
.............

   * Remove *note email.utils.localtime(): 2f7.”s 'isdst' parameter,
     which was deprecated in and has been ignored since Python 3.12.
     (Contributed by Hugo van Kemenade in gh-118798(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118798


File: python.info,  Node: importlib abc,  Next: itertools,  Prev: email,  Up: Removed

1.1.7.5 importlib.abc
.....................

   * Remove deprecated *note importlib.abc: 7c. classes:

        * ‘ResourceReader’ (use *note TraversableResources: 2f9.)

        * ‘Traversable’ (use *note Traversable: 2fa.)

        * ‘TraversableResources’ (use *note TraversableResources: 2f9.)

     (Contributed by Jason R. Coombs and Hugo van Kemenade in
     gh-93963(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/93963


File: python.info,  Node: itertools,  Next: pathlib<3>,  Prev: importlib abc,  Up: Removed

1.1.7.6 itertools
.................

   * Remove support for copy, deepcopy, and pickle operations from *note
     itertools: 85. iterators.  These have emitted a *note
     DeprecationWarning: 1a3. since Python 3.12.  (Contributed by
     Raymond Hettinger in gh-101588(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101588


File: python.info,  Node: pathlib<3>,  Next: pkgutil,  Prev: itertools,  Up: Removed

1.1.7.7 pathlib
...............

   * Remove support for passing additional keyword arguments to *note
     Path: 266.  In previous versions, any such arguments are ignored.
     (Contributed by Barney Gale in gh-74033(1).)

   * Remove support for passing additional positional arguments to *note
     PurePath.relative_to(): 2fd. and *note is_relative_to(): 2fe.  In
     previous versions, any such arguments are joined onto 'other'.
     (Contributed by Barney Gale in gh-78707(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/74033

   (2) https://github.com/python/cpython/issues/78707


File: python.info,  Node: pkgutil,  Next: pty,  Prev: pathlib<3>,  Up: Removed

1.1.7.8 pkgutil
...............

   * Remove the ‘get_loader()’ and ‘find_loader()’ functions, which have
     been deprecated since Python 3.12.  (Contributed by Bénédikt Tran
     in gh-97850(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97850


File: python.info,  Node: pty,  Next: sqlite3,  Prev: pkgutil,  Up: Removed

1.1.7.9 pty
...........

   * Remove the ‘master_open()’ and ‘slave_open()’ functions, which have
     been deprecated since Python 3.12.  Use *note pty.openpty(): 301.
     instead.  (Contributed by Nikita Sobolev in gh-118824(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118824


File: python.info,  Node: sqlite3,  Next: urllib<2>,  Prev: pty,  Up: Removed

1.1.7.10 sqlite3
................

   * Remove ‘version’ and ‘version_info’ from the *note sqlite3: d4.
     module; use *note sqlite_version: 303. and *note
     sqlite_version_info: 304. for the actual version number of the
     runtime SQLite library.  (Contributed by Hugo van Kemenade in
     gh-118924(1).)

   * Using a sequence of parameters with named placeholders now raises a
     *note ProgrammingError: 305, having been deprecated since Python
     3.12.  (Contributed by Erlend E. Aasland in gh-118928(2) and
     gh-101693(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118924

   (2) https://github.com/python/cpython/issues/118928

   (3) https://github.com/python/cpython/issues/101693


File: python.info,  Node: urllib<2>,  Prev: sqlite3,  Up: Removed

1.1.7.11 urllib
...............

   * Remove the ‘Quoter’ class from *note urllib.parse: 110, which has
     been deprecated since Python 3.11.  (Contributed by Nikita Sobolev
     in gh-118827(1).)

   * Remove the ‘URLopener’ and ‘FancyURLopener’ classes from *note
     urllib.request: 111, which have been deprecated since Python 3.3.

     ‘myopener.open()’ can be replaced with *note urlopen(): 307.
     ‘myopener.retrieve()’ can be replaced with *note urlretrieve():
     308.  Customisations to the opener classes can be replaced by
     passing customized handlers to *note build_opener(): 309.
     (Contributed by Barney Gale in gh-84850(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118827

   (2) https://github.com/python/cpython/issues/84850


File: python.info,  Node: Deprecated,  Next: CPython bytecode changes,  Prev: Removed,  Up: What’s new in Python 3 14

1.1.8 Deprecated
----------------

* Menu:

* New deprecations::
* Pending removal in Python 3.15: Pending removal in Python 3 15.
* Pending removal in Python 3.16: Pending removal in Python 3 16.
* Pending removal in Python 3.17: Pending removal in Python 3 17.
* Pending removal in Python 3.18: Pending removal in Python 3 18.
* Pending removal in Python 3.19: Pending removal in Python 3 19.
* Pending removal in future versions::


File: python.info,  Node: New deprecations,  Next: Pending removal in Python 3 15,  Up: Deprecated

1.1.8.1 New deprecations
........................

   * Passing a complex number as the 'real' or 'imag' argument in the
     *note complex(): 197. constructor is now deprecated; complex
     numbers should only be passed as a single positional argument.
     (Contributed by Serhiy Storchaka in gh-109218(1).)

   * *note argparse: 7.:

        * Passing the undocumented keyword argument 'prefix_chars' to
          the *note add_argument_group(): 2eb. method is now deprecated.
          (Contributed by Savannah Ostrowski in gh-125563(2).)

        * Deprecated the *note argparse.FileType: 30c. type converter.
          Anything relating to resource management should be handled
          downstream, after the arguments have been parsed.
          (Contributed by Serhiy Storchaka in gh-58032(3).)

   * *note asyncio: b.:

        * The ‘asyncio.iscoroutinefunction()’ is now deprecated and will
          be removed in Python 3.16; use *note
          inspect.iscoroutinefunction(): 30d. instead.  (Contributed by
          Jiahao Li and Kumar Aditya in gh-122875(4).)

        * The *note asyncio: b. policy system is deprecated and will be
          removed in Python 3.16.  In particular, the following classes
          and functions are deprecated:

             * *note asyncio.AbstractEventLoopPolicy: 30e.

             * *note asyncio.DefaultEventLoopPolicy: 30f.

             * *note asyncio.WindowsSelectorEventLoopPolicy: 310.

             * *note asyncio.WindowsProactorEventLoopPolicy: 311.

             * *note asyncio.get_event_loop_policy(): 312.

             * *note asyncio.set_event_loop_policy(): 313.

          Users should use *note asyncio.run(): 2f3. or *note
          asyncio.Runner: 2f5. with the 'loop_factory' argument to use
          the desired event loop implementation.

          For example, to use *note asyncio.SelectorEventLoop: 314. on
          Windows:

               import asyncio

               async def main():
                   ...

               asyncio.run(main(), loop_factory=asyncio.SelectorEventLoop)

          (Contributed by Kumar Aditya in gh-127949(5).)

   * *note codecs: 1c.: The *note codecs.open(): 315. function is now
     deprecated, and will be removed in a future version of Python.  Use
     *note open(): 316. instead.  (Contributed by Inada Naoki in
     gh-133036(6).)

   * *note ctypes: 2e.:

        * On non-Windows platforms, setting *note Structure._pack_: 317.
          to use a MSVC-compatible default memory layout is now
          deprecated in favor of setting *note Structure._layout_: 1e7.
          to ‘'ms'’, and will be removed in Python 3.19.  (Contributed
          by Petr Viktorin in gh-131747(7).)

        * Calling *note ctypes.POINTER(): 1f1. on a string is now
          deprecated.  Use *note incomplete types: 318. for
          self-referential structures.  Also, the internal
          ‘ctypes._pointer_type_cache’ is deprecated.  See *note
          ctypes.POINTER(): 1f1. for updated implementation details.
          (Contributed by Sergey Myrianov in gh-100926(8).)

   * *note functools: 63.: Calling the Python implementation of *note
     functools.reduce(): 21a. with 'function' or 'sequence' as keyword
     arguments is now deprecated; the parameters will be made
     positional-only in Python 3.16.  (Contributed by Kirill Podoprigora
     in gh-121676(9).)

   * *note logging: 8b.: Support for custom logging handlers with the
     'strm' argument is now deprecated and scheduled for removal in
     Python 3.16.  Define handlers with the 'stream' argument instead.
     (Contributed by Mariusz Felisiak in gh-115032(10).)

   * *note mimetypes: 93.: Valid extensions are either empty or must
     start with “.” for *note mimetypes.MimeTypes.add_type(): 319.
     Undotted extensions are deprecated and will raise a *note
     ValueError: 2ec. in Python 3.16.  (Contributed by Hugo van Kemenade
     in gh-75223(11).)

   * ‘nturl2path’: This module is now deprecated.  Call *note
     urllib.request.url2pathname(): 2bd. and *note pathname2url(): 2bf.
     instead.  (Contributed by Barney Gale in gh-125866(12).)

   * *note os: a5.: The *note os.popen(): 31a. and *note os.spawn*: 31b.
     functions are now *note soft deprecated: 23d.  They should no
     longer be used to write new code.  The *note subprocess: dc. module
     is recommended instead.  (Contributed by Victor Stinner in
     gh-120743(13).)

   * *note pathlib: a8.: ‘pathlib.PurePath.as_uri()’ is now deprecated
     and scheduled for removal in Python 3.19.  Use *note
     pathlib.Path.as_uri(): 31c. instead.  (Contributed by Barney Gale
     in gh-123599(14).)

   * *note pdb: aa.: The undocumented ‘pdb.Pdb.curframe_locals’
     attribute is now a deprecated read-only property, which will be
     removed in a future version of Python.  The low overhead dynamic
     frame locals access added in Python 3.13 by PEP 667(15) means the
     frame locals cache reference previously stored in this attribute is
     no longer needed.  Derived debuggers should access
     ‘pdb.Pdb.curframe.f_locals’ directly in Python 3.13 and later
     versions.  (Contributed by Tian Gao in gh-124369(16) and
     gh-125951(17).)

   * *note symtable: de.: Deprecate *note symtable.Class.get_methods():
     31d. due to the lack of interest, scheduled for removal in Python
     3.16.  (Contributed by Bénédikt Tran in gh-119698(18).)

   * *note tkinter: f6.: The ‘tkinter.Variable’ methods
     ‘trace_variable()’, ‘trace_vdelete()’ and ‘trace_vinfo()’ are now
     deprecated.  Use ‘trace_add()’, ‘trace_remove()’ and ‘trace_info()’
     instead.  (Contributed by Serhiy Storchaka in gh-120220(19).)

   * *note urllib.parse: 110.: Accepting objects with false values (like
     ‘0’ and ‘[]’) except empty strings, bytes-like objects and ‘None’
     in *note parse_qsl(): 31e. and *note parse_qs(): 31f. is now
     deprecated.  (Contributed by Serhiy Storchaka in gh-116897(20).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109218

   (2) https://github.com/python/cpython/issues/125563

   (3) https://github.com/python/cpython/issues/58032

   (4) https://github.com/python/cpython/issues/122875

   (5) https://github.com/python/cpython/issues/127949

   (6) https://github.com/python/cpython/issues/133036

   (7) https://github.com/python/cpython/issues/131747

   (8) https://github.com/python/cpython/issues/100926

   (9) https://github.com/python/cpython/issues/121676

   (10) https://github.com/python/cpython/issues/115032

   (11) https://github.com/python/cpython/issues/75223

   (12) https://github.com/python/cpython/issues/125866

   (13) https://github.com/python/cpython/issues/120743

   (14) https://github.com/python/cpython/issues/123599

   (15) https://peps.python.org/pep-0667/

   (16) https://github.com/python/cpython/issues/124369

   (17) https://github.com/python/cpython/issues/125951

   (18) https://github.com/python/cpython/issues/119698

   (19) https://github.com/python/cpython/issues/120220

   (20) https://github.com/python/cpython/issues/116897


File: python.info,  Node: Pending removal in Python 3 15,  Next: Pending removal in Python 3 16,  Prev: New deprecations,  Up: Deprecated

1.1.8.2 Pending removal in Python 3.15
......................................

   * The import system:

        * Setting *note __cached__: 321. on a module while failing to
          set *note __spec__.cached: 322. is deprecated.  In Python
          3.15, ‘__cached__’ will cease to be set or take into
          consideration by the import system or standard library.
          (gh-97879(1))

        * Setting *note __package__: 323. on a module while failing to
          set *note __spec__.parent: 324. is deprecated.  In Python
          3.15, ‘__package__’ will cease to be set or take into
          consideration by the import system or standard library.
          (gh-97879(2))

   * *note ctypes: 2e.:

        * The undocumented ‘ctypes.SetPointerType()’ function has been
          deprecated since Python 3.13.

   * *note http.server: 76.:

        * The obsolete and rarely used *note CGIHTTPRequestHandler: 325.
          has been deprecated since Python 3.13.  No direct replacement
          exists.  'Anything' is better than CGI to interface a web
          server with a request handler.

        * The ‘--cgi’ flag to the ‘python -m http.server’ command-line
          interface has been deprecated since Python 3.13.

   * *note importlib: 7b.:

        * ‘load_module()’ method: use ‘exec_module()’ instead.

   * *note locale: 8a.:

        * The *note getdefaultlocale(): 326. function has been
          deprecated since Python 3.11.  Its removal was originally
          planned for Python 3.13 (gh-90817(3)), but has been postponed
          to Python 3.15.  Use *note getlocale(): 327, *note
          setlocale(): 328, and *note getencoding(): 329. instead.
          (Contributed by Hugo van Kemenade in gh-111187(4).)

   * *note pathlib: a8.:

        * *note PurePath.is_reserved(): 32a. has been deprecated since
          Python 3.13.  Use *note os.path.isreserved(): 32b. to detect
          reserved paths on Windows.

   * *note platform: af.:

        * *note java_ver(): 32c. has been deprecated since Python 3.13.
          This function is only useful for Jython support, has a
          confusing API, and is largely untested.

   * *note sysconfig: e1.:

        * The 'check_home' argument of *note
          sysconfig.is_python_build(): 32d. has been deprecated since
          Python 3.12.

   * *note threading: f3.:

        * *note RLock(): 32e. will take no arguments in Python 3.15.
          Passing any arguments has been deprecated since Python 3.14,
          as the Python version does not permit any arguments, but the C
          version allows any number of positional or keyword arguments,
          ignoring every argument.

   * *note types: 109.:

        * *note types.CodeType: 32f.: Accessing *note co_lnotab: 330.
          was deprecated in PEP 626(5) since 3.10 and was planned to be
          removed in 3.12, but it only got a proper *note
          DeprecationWarning: 1a3. in 3.12.  May be removed in 3.15.
          (Contributed by Nikita Sobolev in gh-101866(6).)

   * *note typing: 10a.:

        * The undocumented keyword argument syntax for creating *note
          NamedTuple: 331. classes (for example, ‘Point =
          NamedTuple("Point", x=int, y=int)’) has been deprecated since
          Python 3.13.  Use the class-based syntax or the functional
          syntax instead.

        * When using the functional syntax of *note TypedDict: 332.s,
          failing to pass a value to the 'fields' parameter (‘TD =
          TypedDict("TD")’) or passing ‘None’ (‘TD = TypedDict("TD",
          None)’) has been deprecated since Python 3.13.  Use ‘class
          TD(TypedDict): pass’ or ‘TD = TypedDict("TD", {})’ to create a
          TypedDict with zero field.

        * The *note typing.no_type_check_decorator(): 333. decorator
          function has been deprecated since Python 3.13.  After eight
          years in the *note typing: 10a. module, it has yet to be
          supported by any major type checker.

   * *note wave: 119.:

        * The *note getmark(): 334, ‘setmark()’, and *note getmarkers():
          335. methods of the *note Wave_read: 336. and *note
          Wave_write: 337. classes have been deprecated since Python
          3.13.

   * *note zipimport: 138.:

        * *note load_module(): 338. has been deprecated since Python
          3.10.  Use *note exec_module(): 339. instead.  (Contributed by
          Jiahao Li in gh-125746(7).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97879

   (2) https://github.com/python/cpython/issues/97879

   (3) https://github.com/python/cpython/issues/90817

   (4) https://github.com/python/cpython/issues/111187

   (5) https://peps.python.org/pep-0626/

   (6) https://github.com/python/cpython/issues/101866

   (7) https://github.com/python/cpython/issues/125746


File: python.info,  Node: Pending removal in Python 3 16,  Next: Pending removal in Python 3 17,  Prev: Pending removal in Python 3 15,  Up: Deprecated

1.1.8.3 Pending removal in Python 3.16
......................................

   * The import system:

        * Setting *note __loader__: 33b. on a module while failing to
          set *note __spec__.loader: 33c. is deprecated.  In Python
          3.16, ‘__loader__’ will cease to be set or taken into
          consideration by the import system or the standard library.

   * *note array: 8.:

        * The ‘'u'’ format code (‘wchar_t’) has been deprecated in
          documentation since Python 3.3 and at runtime since Python
          3.13.  Use the ‘'w'’ format code (*note Py_UCS4: 33d.) for
          Unicode characters instead.

   * *note asyncio: b.:

        * ‘asyncio.iscoroutinefunction()’ is deprecated and will be
          removed in Python 3.16; use *note
          inspect.iscoroutinefunction(): 30d. instead.  (Contributed by
          Jiahao Li and Kumar Aditya in gh-122875(1).)

        * *note asyncio: b. policy system is deprecated and will be
          removed in Python 3.16.  In particular, the following classes
          and functions are deprecated:

             * *note asyncio.AbstractEventLoopPolicy: 30e.

             * *note asyncio.DefaultEventLoopPolicy: 30f.

             * *note asyncio.WindowsSelectorEventLoopPolicy: 310.

             * *note asyncio.WindowsProactorEventLoopPolicy: 311.

             * *note asyncio.get_event_loop_policy(): 312.

             * *note asyncio.set_event_loop_policy(): 313.

          Users should use *note asyncio.run(): 2f3. or *note
          asyncio.Runner: 2f5. with 'loop_factory' to use the desired
          event loop implementation.

          For example, to use *note asyncio.SelectorEventLoop: 314. on
          Windows:

               import asyncio

               async def main():
                   ...

               asyncio.run(main(), loop_factory=asyncio.SelectorEventLoop)

          (Contributed by Kumar Aditya in gh-127949(2).)

   * *note builtins: 13.:

        * Bitwise inversion on boolean types, ‘~True’ or ‘~False’ has
          been deprecated since Python 3.12, as it produces surprising
          and unintuitive results (‘-2’ and ‘-1’).  Use ‘not x’ instead
          for the logical negation of a Boolean.  In the rare case that
          you need the bitwise inversion of the underlying integer,
          convert to ‘int’ explicitly (‘~int(x)’).

   * *note functools: 63.:

        * Calling the Python implementation of *note functools.reduce():
          21a. with 'function' or 'sequence' as keyword arguments has
          been deprecated since Python 3.14.

   * *note logging: 8b.:

     Support for custom logging handlers with the 'strm' argument is
     deprecated and scheduled for removal in Python 3.16.  Define
     handlers with the 'stream' argument instead.  (Contributed by
     Mariusz Felisiak in gh-115032(3).)

   * *note mimetypes: 93.:

        * Valid extensions start with a “.” or are empty for *note
          mimetypes.MimeTypes.add_type(): 319.  Undotted extensions are
          deprecated and will raise a *note ValueError: 2ec. in Python
          3.16.  (Contributed by Hugo van Kemenade in gh-75223(4).)

   * *note shutil: ca.:

        * The ‘ExecError’ exception has been deprecated since Python
          3.14.  It has not been used by any function in ‘shutil’ since
          Python 3.4, and is now an alias of *note RuntimeError: 244.

   * *note symtable: de.:

        * The *note Class.get_methods: 31d. method has been deprecated
          since Python 3.14.

   * *note sys: df.:

        * The *note _enablelegacywindowsfsencoding(): 33e. function has
          been deprecated since Python 3.13.  Use the *note
          PYTHONLEGACYWINDOWSFSENCODING: 33f. environment variable
          instead.

   * *note sysconfig: e1.:

        * The ‘sysconfig.expand_makefile_vars()’ function has been
          deprecated since Python 3.14.  Use the ‘vars’ argument of
          *note sysconfig.get_paths(): 340. instead.

   * *note tarfile: e4.:

        * The undocumented and unused ‘TarFile.tarfile’ attribute has
          been deprecated since Python 3.13.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/122875

   (2) https://github.com/python/cpython/issues/127949

   (3) https://github.com/python/cpython/issues/115032

   (4) https://github.com/python/cpython/issues/75223


File: python.info,  Node: Pending removal in Python 3 17,  Next: Pending removal in Python 3 18,  Prev: Pending removal in Python 3 16,  Up: Deprecated

1.1.8.4 Pending removal in Python 3.17
......................................

   * *note collections.abc: 1f.:

        - *note collections.abc.ByteString: 342. is scheduled for
          removal in Python 3.17.

          Use ‘isinstance(obj, collections.abc.Buffer)’ to test if ‘obj’
          implements the *note buffer protocol: 260. at runtime.  For
          use in type annotations, either use *note Buffer: 343. or a
          union that explicitly specifies the types your code supports
          (e.g., ‘bytes | bytearray | memoryview’).

          ‘ByteString’ was originally intended to be an abstract class
          that would serve as a supertype of both *note bytes: 192. and
          *note bytearray: 344.  However, since the ABC never had any
          methods, knowing that an object was an instance of
          ‘ByteString’ never actually told you anything useful about the
          object.  Other common buffer types such as *note memoryview:
          165. were also never understood as subtypes of ‘ByteString’
          (either at runtime or by static type checkers).

          See PEP 688(1) for more details.  (Contributed by Shantanu
          Jain in gh-91896(2).)

   * *note typing: 10a.:

        - Before Python 3.14, old-style unions were implemented using
          the private class ‘typing._UnionGenericAlias’.  This class is
          no longer needed for the implementation, but it has been
          retained for backward compatibility, with removal scheduled
          for Python 3.17.  Users should use documented introspection
          helpers like *note typing.get_origin(): 2ab. and *note
          typing.get_args(): 2ac. instead of relying on private
          implementation details.

        - *note typing.ByteString: 345, deprecated since Python 3.9, is
          scheduled for removal in Python 3.17.

          Use ‘isinstance(obj, collections.abc.Buffer)’ to test if ‘obj’
          implements the *note buffer protocol: 260. at runtime.  For
          use in type annotations, either use *note Buffer: 343. or a
          union that explicitly specifies the types your code supports
          (e.g., ‘bytes | bytearray | memoryview’).

          ‘ByteString’ was originally intended to be an abstract class
          that would serve as a supertype of both *note bytes: 192. and
          *note bytearray: 344.  However, since the ABC never had any
          methods, knowing that an object was an instance of
          ‘ByteString’ never actually told you anything useful about the
          object.  Other common buffer types such as *note memoryview:
          165. were also never understood as subtypes of ‘ByteString’
          (either at runtime or by static type checkers).

          See PEP 688(3) for more details.  (Contributed by Shantanu
          Jain in gh-91896(4).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0688/#current-options

   (2) https://github.com/python/cpython/issues/91896

   (3) https://peps.python.org/pep-0688/#current-options

   (4) https://github.com/python/cpython/issues/91896


File: python.info,  Node: Pending removal in Python 3 18,  Next: Pending removal in Python 3 19,  Prev: Pending removal in Python 3 17,  Up: Deprecated

1.1.8.5 Pending removal in Python 3.18
......................................

   * *note decimal: 3a.:

        * The non-standard and undocumented *note Decimal: 1fe. format
          specifier ‘'N'’, which is only supported in the ‘decimal’
          module’s C implementation, has been deprecated since Python
          3.13.  (Contributed by Serhiy Storchaka in gh-89902(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89902


File: python.info,  Node: Pending removal in Python 3 19,  Next: Pending removal in future versions,  Prev: Pending removal in Python 3 18,  Up: Deprecated

1.1.8.6 Pending removal in Python 3.19
......................................

   * *note ctypes: 2e.:

        * Implicitly switching to the MSVC-compatible struct layout by
          setting *note _pack_: 317. but not *note _layout_: 1e7. on
          non-Windows platforms.


File: python.info,  Node: Pending removal in future versions,  Prev: Pending removal in Python 3 19,  Up: Deprecated

1.1.8.7 Pending removal in future versions
..........................................

The following APIs will be removed in the future, although there is
currently no date scheduled for their removal.

   * *note argparse: 7.:

        * Nesting argument groups and nesting mutually exclusive groups
          are deprecated.

        * Passing the undocumented keyword argument 'prefix_chars' to
          *note add_argument_group(): 2eb. is now deprecated.

        * The *note argparse.FileType: 30c. type converter is
          deprecated.

   * *note builtins: 13.:

        * Generators: ‘throw(type, exc, tb)’ and ‘athrow(type, exc, tb)’
          signature is deprecated: use ‘throw(exc)’ and ‘athrow(exc)’
          instead, the single argument signature.

        * Currently Python accepts numeric literals immediately followed
          by keywords, for example ‘0in x’, ‘1or x’, ‘0if 1else 2’.  It
          allows confusing and ambiguous expressions like ‘[0x1for x in
          y]’ (which can be interpreted as ‘[0x1 for x in y]’ or ‘[0x1f
          or x in y]’).  A syntax warning is raised if the numeric
          literal is immediately followed by one of keywords *note and:
          349, *note else: 17c, *note for: 34a, *note if: 181, *note in:
          34b, *note is: 34c. and *note or: 34d.  In a future release it
          will be changed to a syntax error.  (gh-87999(1))

        * Support for ‘__index__()’ and ‘__int__()’ method returning
          non-int type: these methods will be required to return an
          instance of a strict subclass of *note int: 19b.

        * Support for ‘__float__()’ method returning a strict subclass
          of *note float: 196.: these methods will be required to return
          an instance of *note float: 196.

        * Support for ‘__complex__()’ method returning a strict subclass
          of *note complex: 197.: these methods will be required to
          return an instance of *note complex: 197.

        * Delegation of ‘int()’ to ‘__trunc__()’ method.

        * Passing a complex number as the 'real' or 'imag' argument in
          the *note complex(): 197. constructor is now deprecated; it
          should only be passed as a single positional argument.
          (Contributed by Serhiy Storchaka in gh-109218(2).)

   * *note calendar: 15.: ‘calendar.January’ and ‘calendar.February’
     constants are deprecated and replaced by *note calendar.JANUARY:
     34e. and *note calendar.FEBRUARY: 34f.  (Contributed by Prince
     Roshan in gh-103636(3).)

   * *note codecs: 1c.: use *note open(): 316. instead of *note
     codecs.open(): 315.  (gh-133038(4))

   * *note codeobject.co_lnotab: 330.: use the *note
     codeobject.co_lines(): 350. method instead.

   * *note datetime: 34.:

        * *note utcnow(): 351.: use
          ‘datetime.datetime.now(tz=datetime.UTC)’.

        * *note utcfromtimestamp(): 352.: use
          ‘datetime.datetime.fromtimestamp(timestamp, tz=datetime.UTC)’.

   * *note gettext: 67.: Plural value must be an integer.

   * *note importlib: 7b.:

        * *note cache_from_source(): 353. 'debug_override' parameter is
          deprecated: use the 'optimization' parameter instead.

   * *note importlib.metadata: 7e.:

        * ‘EntryPoints’ tuple interface.

        * Implicit ‘None’ on return values.

   * *note logging: 8b.: the ‘warn()’ method has been deprecated since
     Python 3.3, use *note warning(): 354. instead.

   * *note mailbox: 8f.: Use of StringIO input and text mode is
     deprecated, use BytesIO and binary mode instead.

   * *note os: a5.: Calling *note os.register_at_fork(): 355. in
     multi-threaded process.

   * ‘pydoc.ErrorDuringImport’: A tuple value for 'exc_info' parameter
     is deprecated, use an exception instance.

   * *note re: be.: More strict rules are now applied for numerical
     group references and group names in regular expressions.  Only
     sequence of ASCII digits is now accepted as a numerical reference.
     The group name in bytes patterns and replacement strings can now
     only contain ASCII letters and digits and underscore.  (Contributed
     by Serhiy Storchaka in gh-91760(5).)

   * ‘sre_compile’, ‘sre_constants’ and ‘sre_parse’ modules.

   * *note shutil: ca.: *note rmtree(): 356.”s 'onerror' parameter is
     deprecated in Python 3.12; use the 'onexc' parameter instead.

   * *note ssl: d5. options and protocols:

        * *note ssl.SSLContext: 357. without protocol argument is
          deprecated.

        * *note ssl.SSLContext: 357.: *note set_npn_protocols(): 358.
          and ‘selected_npn_protocol()’ are deprecated: use ALPN
          instead.

        * ‘ssl.OP_NO_SSL*’ options

        * ‘ssl.OP_NO_TLS*’ options

        * ‘ssl.PROTOCOL_SSLv3’

        * ‘ssl.PROTOCOL_TLS’

        * ‘ssl.PROTOCOL_TLSv1’

        * ‘ssl.PROTOCOL_TLSv1_1’

        * ‘ssl.PROTOCOL_TLSv1_2’

        * ‘ssl.TLSVersion.SSLv3’

        * ‘ssl.TLSVersion.TLSv1’

        * ‘ssl.TLSVersion.TLSv1_1’

   * *note threading: f3. methods:

        * ‘threading.Condition.notifyAll()’: use *note notify_all():
          359.

        * ‘threading.Event.isSet()’: use *note is_set(): 35a.

        * ‘threading.Thread.isDaemon()’, *note
          threading.Thread.setDaemon(): 35b.: use *note
          threading.Thread.daemon: 35c. attribute.

        * ‘threading.Thread.getName()’, *note
          threading.Thread.setName(): 35d.: use *note
          threading.Thread.name: 2a0. attribute.

        * ‘threading.currentThread()’: use *note
          threading.current_thread(): 35e.

        * ‘threading.activeCount()’: use *note threading.active_count():
          35f.

   * *note typing.Text: 360. (gh-92332(6)).

   * The internal class ‘typing._UnionGenericAlias’ is no longer used to
     implement *note typing.Union: 2a8.  To preserve compatibility with
     users using this private class, a compatibility shim will be
     provided until at least Python 3.17.  (Contributed by Jelle
     Zijlstra in gh-105499(7).)

   * *note unittest.IsolatedAsyncioTestCase: 361.: it is deprecated to
     return a value that is not ‘None’ from a test case.

   * *note urllib.parse: 110. deprecated functions: *note urlparse():
     362. instead

        * ‘splitattr()’

        * ‘splithost()’

        * ‘splitnport()’

        * ‘splitpasswd()’

        * ‘splitport()’

        * ‘splitquery()’

        * ‘splittag()’

        * ‘splittype()’

        * ‘splituser()’

        * ‘splitvalue()’

        * ‘to_bytes()’

   * *note wsgiref: 11e.: ‘SimpleHandler.stdout.write()’ should not do
     partial writes.

   * *note xml.etree.ElementTree: 12b.: Testing the truth value of an
     *note Element: 363. is deprecated.  In a future release it will
     always return ‘True’.  Prefer explicit ‘len(elem)’ or ‘elem is not
     None’ tests instead.

   * *note sys._clear_type_cache(): 292. is deprecated: use *note
     sys._clear_internal_caches(): 364. instead.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/87999

   (2) https://github.com/python/cpython/issues/109218

   (3) https://github.com/python/cpython/issues/103636

   (4) https://github.com/python/cpython/issues/133038

   (5) https://github.com/python/cpython/issues/91760

   (6) https://github.com/python/cpython/issues/92332

   (7) https://github.com/python/cpython/issues/105499


File: python.info,  Node: CPython bytecode changes,  Next: C API changes,  Prev: Deprecated,  Up: What’s new in Python 3 14

1.1.9 CPython bytecode changes
------------------------------

   * Replaced the opcode ‘BINARY_SUBSCR’ by the *note BINARY_OP: 366.
     opcode with the ‘NB_SUBSCR’ oparg.  (Contributed by Irit Katriel in
     gh-100239(1).)

   * Add the *note BUILD_INTERPOLATION: 367. and *note BUILD_TEMPLATE:
     368. opcodes to construct new *note Interpolation: 16b. and *note
     Template: 16a. instances, respectively.  (Contributed by Lysandros
     Nikolaou and others in gh-132661(2); see also *note PEP 750;
     Template strings: 144.).

   * Remove the ‘BUILD_CONST_KEY_MAP’ opcode.  Use *note BUILD_MAP: 369.
     instead.  (Contributed by Mark Shannon in gh-122160(3).)

   * Replace the ‘LOAD_ASSERTION_ERROR’ opcode with *note
     LOAD_COMMON_CONSTANT: 36a. and add support for loading *note
     NotImplementedError: 36b.

   * Add the *note LOAD_FAST_BORROW: 36c. and *note
     LOAD_FAST_BORROW_LOAD_FAST_BORROW: 36d. opcodes to reduce reference
     counting overhead when the interpreter can prove that the reference
     in the frame outlives the reference loaded onto the stack.
     (Contributed by Matt Page in gh-130704(4).)

   * Add the *note LOAD_SMALL_INT: 36e. opcode, which pushes a small
     integer equal to the ‘oparg’ to the stack.  The ‘RETURN_CONST’
     opcode is removed as it is no longer used.  (Contributed by Mark
     Shannon in gh-125837(5).)

   * Add the new *note LOAD_SPECIAL: 36f. instruction.  Generate code
     for *note with: 186. and *note async with: 185. statements using
     the new instruction.  Removed the ‘BEFORE_WITH’ and
     ‘BEFORE_ASYNC_WITH’ instructions.  (Contributed by Mark Shannon in
     gh-120507(6).)

   * Add the *note POP_ITER: 370. opcode to support “virtual” iterators.
     (Contributed by Mark Shannon in gh-132554(7).)

* Menu:

* Pseudo-instructions::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100239

   (2) https://github.com/python/cpython/issues/132661

   (3) https://github.com/python/cpython/issues/122160

   (4) https://github.com/python/cpython/issues/130704

   (5) https://github.com/python/cpython/issues/125837

   (6) https://github.com/python/cpython/issues/120507

   (7) https://github.com/python/cpython/issues/132554


File: python.info,  Node: Pseudo-instructions,  Up: CPython bytecode changes

1.1.9.1 Pseudo-instructions
...........................

   * Add the ‘ANNOTATIONS_PLACEHOLDER’ pseudo instruction to support
     partially executed module-level annotations with *note deferred
     evaluation of annotations: 145.  (Contributed by Jelle Zijlstra in
     gh-130907(1).)

   * Add the ‘BINARY_OP_EXTEND’ pseudo instruction, which executes a
     pair of functions (guard and specialization functions) accessed
     from the inline cache.  (Contributed by Irit Katriel in
     gh-100239(2).)

   * Add three specializations for *note CALL_KW: 372.; ‘CALL_KW_PY’ for
     calls to Python functions, ‘CALL_KW_BOUND_METHOD’ for calls to
     bound methods, and ‘CALL_KW_NON_PY’ for all other calls.
     (Contributed by Mark Shannon in gh-118093(3).)

   * Add the *note JUMP_IF_TRUE: 373. and *note JUMP_IF_FALSE: 374.
     pseudo instructions, conditional jumps which do not impact the
     stack.  Replaced by the sequence ‘COPY 1’, ‘TO_BOOL’,
     ‘POP_JUMP_IF_TRUE/FALSE’.  (Contributed by Irit Katriel in
     gh-124285(4).)

   * Add the ‘LOAD_CONST_MORTAL’ pseudo instruction.  (Contributed by
     Mark Shannon in gh-128685(5).)

   * Add the *note LOAD_CONST_IMMORTAL: 375. pseudo instruction, which
     does the same as ‘LOAD_CONST’, but is more efficient for immortal
     objects.  (Contributed by Mark Shannon in gh-125837(6).)

   * Add the *note NOT_TAKEN: 376. pseudo instruction, used by *note
     sys.monitoring: e0. to record branch events (such as *note
     BRANCH_LEFT: 295.).  (Contributed by Mark Shannon in gh-122548(7).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/130907

   (2) https://github.com/python/cpython/issues/100239

   (3) https://github.com/python/cpython/issues/118093

   (4) https://github.com/python/cpython/issues/124285

   (5) https://github.com/python/cpython/issues/128685

   (6) https://github.com/python/cpython/issues/125837

   (7) https://github.com/python/cpython/issues/122548


File: python.info,  Node: C API changes,  Next: Build changes,  Prev: CPython bytecode changes,  Up: What’s new in Python 3 14

1.1.10 C API changes
--------------------

* Menu:

* Python configuration C API::
* New features in the C API::
* Limited C API changes::
* Removed C APIs::
* Deprecated C APIs::


File: python.info,  Node: Python configuration C API,  Next: New features in the C API,  Up: C API changes

1.1.10.1 Python configuration C API
...................................

Add a *note PyInitConfig C API: 379. to configure the Python
initialization without relying on C structures and the ability to make
ABI-compatible changes in the future.

Complete the PEP 587(1) *note PyConfig C API: 37a. by adding *note
PyInitConfig_AddModule(): 37b. which can be used to add a built-in
extension module; a feature previously referred to as the «inittab».

Add *note PyConfig_Get(): 37c. and *note PyConfig_Set(): 37d. functions
to get and set the current runtime configuration.

PEP 587(2) “Python Initialization Configuration” unified all the ways to
configure Python’s initialization.  This PEP also unifies the
configuration of Python’s preinitialization and initialization in a
single API. Moreover, this PEP only provides a single choice to embed
Python, instead of having two “Python” and “Isolated” choices (PEP 587),
to further simplify the API.

The lower level PEP 587 PyConfig API remains available for use cases
with an intentionally higher level of coupling to CPython implementation
details (such as emulating the full functionality of CPython’s CLI,
including its configuration mechanisms).

(Contributed by Victor Stinner in gh-107954(3).)

Vedi anche
..........

PEP 741(4) and PEP 587(5)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0587/

   (2) https://peps.python.org/pep-0587/

   (3) https://github.com/python/cpython/issues/107954

   (4) https://peps.python.org/pep-0741/

   (5) https://peps.python.org/pep-0587/


File: python.info,  Node: New features in the C API,  Next: Limited C API changes,  Prev: Python configuration C API,  Up: C API changes

1.1.10.2 New features in the C API
..................................

   * Add *note Py_PACK_VERSION(): 37f. and *note Py_PACK_FULL_VERSION():
     380, two new macros for bit-packing Python version numbers.  This
     is useful for comparisons with *note Py_Version: 381. or *note
     PY_VERSION_HEX: 382.  (Contributed by Petr Viktorin in
     gh-128629(1).)

   * Add *note PyBytes_Join(sep, iterable): 383. function, similar to
     ‘sep.join(iterable)’ in Python.  (Contributed by Victor Stinner in
     gh-121645(2).)

   * Add functions to manipulate the configuration of the current
     runtime Python interpreter (*note PEP 741; Python configuration C
     API: 155.):

        * *note PyConfig_Get(): 37c.

        * *note PyConfig_GetInt(): 384.

        * *note PyConfig_Set(): 37d.

        * *note PyConfig_Names(): 385.

     (Contributed by Victor Stinner in gh-107954(3).)

   * Add functions to configure Python initialization (*note PEP 741;
     Python configuration C API: 155.):

        * *note Py_InitializeFromInitConfig(): 386.

        * *note PyInitConfig_AddModule(): 37b.

        * *note PyInitConfig_Create(): 387.

        * *note PyInitConfig_Free(): 388.

        * *note PyInitConfig_FreeStrList(): 389.

        * *note PyInitConfig_GetError(): 38a.

        * *note PyInitConfig_GetExitCode(): 38b.

        * *note PyInitConfig_GetInt(): 38c.

        * *note PyInitConfig_GetStr(): 38d.

        * *note PyInitConfig_GetStrList(): 38e.

        * *note PyInitConfig_HasOption(): 38f.

        * *note PyInitConfig_SetInt(): 390.

        * *note PyInitConfig_SetStr(): 391.

        * *note PyInitConfig_SetStrList(): 392.

     (Contributed by Victor Stinner in gh-107954(4).)

   * Add *note Py_fopen(): 393. function to open a file.  This works
     similarly to the standard C ‘fopen()’ function, instead accepting a
     Python object for the 'path' parameter and setting an exception on
     error.  The corresponding new *note Py_fclose(): 394. function
     should be used to close a file.  (Contributed by Victor Stinner in
     gh-127350(5).)

   * Add *note Py_HashBuffer(): 395. to compute and return the hash
     value of a buffer.  (Contributed by Antoine Pitrou and Victor
     Stinner in gh-122854(6).)

   * Add *note PyImport_ImportModuleAttr(): 396. and *note
     PyImport_ImportModuleAttrString(): 397. helper functions to import
     a module and get an attribute of the module.  (Contributed by
     Victor Stinner in gh-128911(7).)

   * Add *note PyIter_NextItem(): 398. to replace *note PyIter_Next():
     399, which has an ambiguous return value.  (Contributed by Irit
     Katriel and Erlend Aasland in gh-105201(8).)

   * Add *note PyLong_GetSign(): 39a. function to get the sign of *note
     int: 19b. objects.  (Contributed by Sergey B Kirpichev in
     gh-116560(9).)

   * Add *note PyLong_IsPositive(): 39b, *note PyLong_IsNegative(): 39c.
     and *note PyLong_IsZero(): 39d. for checking if *note PyLongObject:
     39e. is positive, negative, or zero, respectively.  (Contributed by
     James Roy and Sergey B Kirpichev in gh-126061(10).)

   * Add new functions to convert C ‘<stdint.h>’ numbers to/from Python
     *note int: 19b. objects:

        * *note PyLong_AsInt32(): 39f.

        * *note PyLong_AsInt64(): 3a0.

        * *note PyLong_AsUInt32(): 3a1.

        * *note PyLong_AsUInt64(): 3a2.

        * *note PyLong_FromInt32(): 3a3.

        * *note PyLong_FromInt64(): 3a4.

        * *note PyLong_FromUInt32(): 3a5.

        * *note PyLong_FromUInt64(): 3a6.

     (Contributed by Victor Stinner in gh-120389(11).)

   * Add a new import and export API for Python *note int: 19b. objects
     ( PEP 757(12)):

        * *note PyLong_GetNativeLayout(): 3a7.

        * *note PyLong_Export(): 3a8.

        * *note PyLong_FreeExport(): 3a9.

        * *note PyLongWriter_Create(): 3aa.

        * *note PyLongWriter_Finish(): 3ab.

        * *note PyLongWriter_Discard(): 3ac.

     (Contributed by Sergey B Kirpichev and Victor Stinner in
     gh-102471(13).)

   * Add *note PyMonitoring_FireBranchLeftEvent(): 3ad. and *note
     PyMonitoring_FireBranchRightEvent(): 3ae. for generating *note
     BRANCH_LEFT: 295. and *note BRANCH_RIGHT: 296. events,
     respectively.  (Contributed by Mark Shannon in gh-122548(14).)

   * Add *note PyType_Freeze(): 3af. function to make a type immutable.
     (Contributed by Victor Stinner in gh-121654(15).)

   * Add *note PyType_GetBaseByToken(): 3b0. and *note Py_tp_token: 3b1.
     slot for easier superclass identification, which attempts to
     resolve the type checking issue mentioned in PEP 630(16).
     (Contributed in gh-124153(17).)

   * Add a new *note PyUnicode_Equal(): 3b2. function to test if two
     strings are equal.  The function is also added to the Limited C
     API.  (Contributed by Victor Stinner in gh-124502(18).)

   * Add a new *note PyUnicodeWriter: 3b3. API to create a Python *note
     str: 169. object, with the following functions:

        * *note PyUnicodeWriter_Create(): 3b4.

        * *note PyUnicodeWriter_DecodeUTF8Stateful(): 3b5.

        * *note PyUnicodeWriter_Discard(): 3b6.

        * *note PyUnicodeWriter_Finish(): 3b7.

        * *note PyUnicodeWriter_Format(): 3b8.

        * *note PyUnicodeWriter_WriteASCII(): 3b9.

        * *note PyUnicodeWriter_WriteChar(): 3ba.

        * *note PyUnicodeWriter_WriteRepr(): 3bb.

        * *note PyUnicodeWriter_WriteStr(): 3bc.

        * *note PyUnicodeWriter_WriteSubstring(): 3bd.

        * *note PyUnicodeWriter_WriteUCS4(): 3be.

        * *note PyUnicodeWriter_WriteUTF8(): 3bf.

        * *note PyUnicodeWriter_WriteWideChar(): 3c0.

     (Contributed by Victor Stinner in gh-119182(19).)

   * The ‘k’ and ‘K’ formats in *note PyArg_ParseTuple(): 3c1. and
     similar functions now use *note __index__(): 19e. if available,
     like all other integer formats.  (Contributed by Serhiy Storchaka
     in gh-112068(20).)

   * Add support for a new ‘p’ format unit in *note Py_BuildValue():
     3c2. that produces a Python *note bool: 3c3. object from a C
     integer.  (Contributed by Pablo Galindo in bpo-45325(21).)

   * Add *note PyUnstable_IsImmortal(): 3c4. for determining if an
     object is *note immortal: 290, for debugging purposes.
     (Contributed by Peter Bierma in gh-128509(22).)

   * Add *note PyUnstable_Object_EnableDeferredRefcount(): 3c5. for
     enabling deferred reference counting, as outlined in PEP 703(23).

   * Add *note PyUnstable_Object_IsUniquelyReferenced(): 3c6. as a
     replacement for ‘Py_REFCNT(op) == 1’ on *note free threaded: 1f4.
     builds.  (Contributed by Peter Bierma in gh-133140(24).)

   * Add *note PyUnstable_Object_IsUniqueReferencedTemporary(): 3c7. to
     determine if an object is a unique temporary object on the
     interpreter’s operand stack.  This can be used in some cases as a
     replacement for checking if *note Py_REFCNT(): 2cf. is ‘1’ for
     Python objects passed as arguments to C API functions.
     (Contributed by Sam Gross in gh-133164(25).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128629

   (2) https://github.com/python/cpython/issues/121645

   (3) https://github.com/python/cpython/issues/107954

   (4) https://github.com/python/cpython/issues/107954

   (5) https://github.com/python/cpython/issues/127350

   (6) https://github.com/python/cpython/issues/122854

   (7) https://github.com/python/cpython/issues/128911

   (8) https://github.com/python/cpython/issues/105201

   (9) https://github.com/python/cpython/issues/116560

   (10) https://github.com/python/cpython/issues/126061

   (11) https://github.com/python/cpython/issues/120389

   (12) https://peps.python.org/pep-0757/

   (13) https://github.com/python/cpython/issues/102471

   (14) https://github.com/python/cpython/issues/122548

   (15) https://github.com/python/cpython/issues/121654

   (16) https://peps.python.org/pep-0630/#type-checking

   (17) https://github.com/python/cpython/issues/124153

   (18) https://github.com/python/cpython/issues/124502

   (19) https://github.com/python/cpython/issues/119182

   (20) https://github.com/python/cpython/issues/112068

   (21) https://bugs.python.org/issue?@action=redirect&bpo=45325

   (22) https://github.com/python/cpython/issues/128509

   (23) https://peps.python.org/pep-0703/

   (24) https://github.com/python/cpython/issues/133140

   (25) https://github.com/python/cpython/issues/133164


File: python.info,  Node: Limited C API changes,  Next: Removed C APIs,  Prev: New features in the C API,  Up: C API changes

1.1.10.3 Limited C API changes
..............................

   * In the limited C API version 3.14 and newer, *note Py_TYPE(): 3c9.
     and *note Py_REFCNT(): 2cf. are now implemented as an opaque
     function call to hide implementation details.  (Contributed by
     Victor Stinner in gh-120600(1) and gh-124127(2).)

   * Remove the *note PySequence_Fast_GET_SIZE: 3ca, *note
     PySequence_Fast_GET_ITEM: 3cb, and *note PySequence_Fast_ITEMS:
     3cc. macros from the limited C API, since they have always been
     broken in the limited C API. (Contributed by Victor Stinner in
     gh-91417(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/120600

   (2) https://github.com/python/cpython/issues/124127

   (3) https://github.com/python/cpython/issues/91417


File: python.info,  Node: Removed C APIs,  Next: Deprecated C APIs,  Prev: Limited C API changes,  Up: C API changes

1.1.10.4 Removed C APIs
.......................

   * Creating *note immutable types: 3cf. with mutable bases was
     deprecated in Python 3.12, and now raises a *note TypeError: 198.
     (Contributed by Nikita Sobolev in gh-119775(1).)

   * Remove ‘PyDictObject.ma_version_tag’ member, which was deprecated
     in Python 3.12.  Use the *note PyDict_AddWatcher(): 3d0. API
     instead.  (Contributed by Sam Gross in gh-124296(2).)

   * Remove the private ‘_Py_InitializeMain()’ function.  It was a *note
     provisional API: 3d1. added to Python 3.8 by PEP 587(3).
     (Contributed by Victor Stinner in gh-129033(4).)

   * Remove the undocumented APIs ‘Py_C_RECURSION_LIMIT’ and
     ‘PyThreadState.c_recursion_remaining’.  These were added in 3.13
     and have been removed without deprecation.  Use *note
     Py_EnterRecursiveCall(): 3d2. to guard against runaway recursion in
     C code.  (Removed by Petr Viktorin in gh-133079(5), see also
     gh-130396(6).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/119775

   (2) https://github.com/python/cpython/issues/124296

   (3) https://peps.python.org/pep-0587/

   (4) https://github.com/python/cpython/issues/129033

   (5) https://github.com/python/cpython/issues/133079

   (6) https://github.com/python/cpython/issues/130396


File: python.info,  Node: Deprecated C APIs,  Prev: Removed C APIs,  Up: C API changes

1.1.10.5 Deprecated C APIs
..........................

   * The ‘Py_HUGE_VAL’ macro is now *note soft deprecated: 23d.  Use
     ‘Py_INFINITY’ instead.  (Contributed by Sergey B Kirpichev in
     gh-120026(1).)

   * The ‘Py_IS_NAN’, ‘Py_IS_INFINITY’, and ‘Py_IS_FINITE’ macros are
     now *note soft deprecated: 23d.  Use ‘isnan’, ‘isinf’ and
     ‘isfinite’ instead, available from ‘math.h’ since C99.
     (Contributed by Sergey B Kirpichev in gh-119613(2).)

   * Non-tuple sequences are now deprecated as argument for the
     ‘(items)’ format unit in *note PyArg_ParseTuple(): 3c1. and other
     *note argument parsing: 3d5. functions if 'items' contains format
     units which store a *note borrowed buffer: 3d6. or a *note borrowed
     reference: 3d7.  (Contributed by Serhiy Storchaka in gh-50333(3).)

   * The ‘_PyMonitoring_FireBranchEvent’ function is now deprecated and
     should be replaced with calls to *note
     PyMonitoring_FireBranchLeftEvent(): 3ad. and *note
     PyMonitoring_FireBranchRightEvent(): 3ae.

   * The previously undocumented function *note PySequence_In(): 3d8. is
     now *note soft deprecated: 23d.  Use *note PySequence_Contains():
     3d9. instead.  (Contributed by Yuki Kobayashi in gh-127896(4).)

* Menu:

* Pending removal in Python 3.15: Pending removal in Python 3 15<2>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<2>.
* Pending removal in Python 3.18: Pending removal in Python 3 18<2>.
* Pending removal in future versions: Pending removal in future versions<2>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/120026

   (2) https://github.com/python/cpython/issues/119613

   (3) https://github.com/python/cpython/issues/50333

   (4) https://github.com/python/cpython/issues/127896


File: python.info,  Node: Pending removal in Python 3 15<2>,  Next: Pending removal in Python 3 16<2>,  Up: Deprecated C APIs

1.1.10.6 Pending removal in Python 3.15
.......................................

   * The *note PyImport_ImportModuleNoBlock(): 3db.: Use *note
     PyImport_ImportModule(): 3dc. instead.

   * *note PyWeakref_GetObject(): 3dd. and *note PyWeakref_GET_OBJECT():
     3de.: Use *note PyWeakref_GetRef(): 3df. instead.  The
     pythoncapi-compat project(1) can be used to get *note
     PyWeakref_GetRef(): 3df. on Python 3.12 and older.

   * *note Py_UNICODE: 3e0. type and the ‘Py_UNICODE_WIDE’ macro: Use
     ‘wchar_t’ instead.

   * ‘PyUnicode_AsDecodedObject()’: Use *note PyCodec_Decode(): 3e1.
     instead.

   * ‘PyUnicode_AsDecodedUnicode()’: Use *note PyCodec_Decode(): 3e1.
     instead; Note that some codecs (for example, «base64») may return a
     type other than *note str: 169, such as *note bytes: 192.

   * ‘PyUnicode_AsEncodedObject()’: Use *note PyCodec_Encode(): 3e2.
     instead.

   * ‘PyUnicode_AsEncodedUnicode()’: Use *note PyCodec_Encode(): 3e2.
     instead; Note that some codecs (for example, «base64») may return a
     type other than *note bytes: 192, such as *note str: 169.

   * Python initialization functions, deprecated in Python 3.13:

        * *note Py_GetPath(): 3e3.: Use *note
          PyConfig_Get("module_search_paths"): 37c. (*note sys.path:
          3e4.) instead.

        * *note Py_GetPrefix(): 3e5.: Use *note
          PyConfig_Get("base_prefix"): 37c. (*note sys.base_prefix:
          3e6.) instead.  Use *note PyConfig_Get("prefix"): 37c. (*note
          sys.prefix: 3e7.) if *note virtual environments: 3e8. need to
          be handled.

        * *note Py_GetExecPrefix(): 3e9.: Use *note
          PyConfig_Get("base_exec_prefix"): 37c. (*note
          sys.base_exec_prefix: 3ea.) instead.  Use *note
          PyConfig_Get("exec_prefix"): 37c. (*note sys.exec_prefix:
          3eb.) if *note virtual environments: 3e8. need to be handled.

        * *note Py_GetProgramFullPath(): 3ec.: Use *note
          PyConfig_Get("executable"): 37c. (*note sys.executable: 3ed.)
          instead.

        * *note Py_GetProgramName(): 3ee.: Use *note
          PyConfig_Get("executable"): 37c. (*note sys.executable: 3ed.)
          instead.

        * *note Py_GetPythonHome(): 3ef.: Use *note
          PyConfig_Get("home"): 37c. or the *note PYTHONHOME: 3f0.
          environment variable instead.

     The pythoncapi-compat project(2) can be used to get *note
     PyConfig_Get(): 37c. on Python 3.13 and older.

   * Functions to configure Python’s initialization, deprecated in
     Python 3.11:

        * ‘PySys_SetArgvEx()’: Set *note PyConfig.argv: 3f1. instead.

        * ‘PySys_SetArgv()’: Set *note PyConfig.argv: 3f1. instead.

        * ‘Py_SetProgramName()’: Set *note PyConfig.program_name: 3f2.
          instead.

        * ‘Py_SetPythonHome()’: Set *note PyConfig.home: 3f3. instead.

        * *note PySys_ResetWarnOptions(): 3f4.: Clear *note
          sys.warnoptions: 3f5. and ‘warnings.filters’ instead.

     The *note Py_InitializeFromConfig(): 3f6. API should be used with
     *note PyConfig: 3f7. instead.

   * Global configuration variables:

        * *note Py_DebugFlag: 3f8.: Use *note PyConfig.parser_debug:
          3f9. or *note PyConfig_Get("parser_debug"): 37c. instead.

        * *note Py_VerboseFlag: 3fa.: Use *note PyConfig.verbose: 3fb.
          or *note PyConfig_Get("verbose"): 37c. instead.

        * *note Py_QuietFlag: 3fc.: Use *note PyConfig.quiet: 3fd. or
          *note PyConfig_Get("quiet"): 37c. instead.

        * *note Py_InteractiveFlag: 3fe.: Use *note
          PyConfig.interactive: 3ff. or *note
          PyConfig_Get("interactive"): 37c. instead.

        * *note Py_InspectFlag: 400.: Use *note PyConfig.inspect: 401.
          or *note PyConfig_Get("inspect"): 37c. instead.

        * *note Py_OptimizeFlag: 402.: Use *note
          PyConfig.optimization_level: 403. or *note
          PyConfig_Get("optimization_level"): 37c. instead.

        * *note Py_NoSiteFlag: 404.: Use *note PyConfig.site_import:
          405. or *note PyConfig_Get("site_import"): 37c. instead.

        * *note Py_BytesWarningFlag: 406.: Use *note
          PyConfig.bytes_warning: 407. or *note
          PyConfig_Get("bytes_warning"): 37c. instead.

        * *note Py_FrozenFlag: 408.: Use *note
          PyConfig.pathconfig_warnings: 409. or *note
          PyConfig_Get("pathconfig_warnings"): 37c. instead.

        * *note Py_IgnoreEnvironmentFlag: 40a.: Use *note
          PyConfig.use_environment: 40b. or *note
          PyConfig_Get("use_environment"): 37c. instead.

        * *note Py_DontWriteBytecodeFlag: 40c.: Use *note
          PyConfig.write_bytecode: 40d. or *note
          PyConfig_Get("write_bytecode"): 37c. instead.

        * *note Py_NoUserSiteDirectory: 40e.: Use *note
          PyConfig.user_site_directory: 40f. or *note
          PyConfig_Get("user_site_directory"): 37c. instead.

        * *note Py_UnbufferedStdioFlag: 410.: Use *note
          PyConfig.buffered_stdio: 411. or *note
          PyConfig_Get("buffered_stdio"): 37c. instead.

        * *note Py_HashRandomizationFlag: 412.: Use *note
          PyConfig.use_hash_seed: 413. and *note PyConfig.hash_seed:
          414. or *note PyConfig_Get("hash_seed"): 37c. instead.

        * *note Py_IsolatedFlag: 415.: Use *note PyConfig.isolated: 416.
          or *note PyConfig_Get("isolated"): 37c. instead.

        * *note Py_LegacyWindowsFSEncodingFlag: 417.: Use *note
          PyPreConfig.legacy_windows_fs_encoding: 418. or *note
          PyConfig_Get("legacy_windows_fs_encoding"): 37c. instead.

        * *note Py_LegacyWindowsStdioFlag: 419.: Use *note
          PyConfig.legacy_windows_stdio: 41a. or *note
          PyConfig_Get("legacy_windows_stdio"): 37c. instead.

        * ‘Py_FileSystemDefaultEncoding’,
          ‘Py_HasFileSystemDefaultEncoding’: Use *note
          PyConfig.filesystem_encoding: 41b. or *note
          PyConfig_Get("filesystem_encoding"): 37c. instead.

        * ‘Py_FileSystemDefaultEncodeErrors’: Use *note
          PyConfig.filesystem_errors: 41c. or *note
          PyConfig_Get("filesystem_errors"): 37c. instead.

        * ‘Py_UTF8Mode’: Use *note PyPreConfig.utf8_mode: 41d. or *note
          PyConfig_Get("utf8_mode"): 37c. instead.  (see *note
          Py_PreInitialize(): 41e.)

     The *note Py_InitializeFromConfig(): 3f6. API should be used with
     *note PyConfig: 3f7. to set these options.  Or *note
     PyConfig_Get(): 37c. can be used to get these options at runtime.

   ---------- Footnotes ----------

   (1) https://github.com/python/pythoncapi-compat/

   (2) https://github.com/python/pythoncapi-compat/


File: python.info,  Node: Pending removal in Python 3 16<2>,  Next: Pending removal in Python 3 18<2>,  Prev: Pending removal in Python 3 15<2>,  Up: Deprecated C APIs

1.1.10.7 Pending removal in Python 3.16
.......................................

   * The bundled copy of ‘libmpdec’.


File: python.info,  Node: Pending removal in Python 3 18<2>,  Next: Pending removal in future versions<2>,  Prev: Pending removal in Python 3 16<2>,  Up: Deprecated C APIs

1.1.10.8 Pending removal in Python 3.18
.......................................

   * The following private functions are deprecated and planned for
     removal in Python 3.18:

        * ‘_PyBytes_Join()’: use *note PyBytes_Join(): 383.

        * ‘_PyDict_GetItemStringWithError()’: use *note
          PyDict_GetItemStringRef(): 421.

        * ‘_PyDict_Pop()’: use *note PyDict_Pop(): 422.

        * ‘_PyLong_Sign()’: use *note PyLong_GetSign(): 39a.

        * ‘_PyLong_FromDigits()’ and ‘_PyLong_New()’: use *note
          PyLongWriter_Create(): 3aa.

        * ‘_PyThreadState_UncheckedGet()’: use *note
          PyThreadState_GetUnchecked(): 423.

        * ‘_PyUnicode_AsString()’: use *note PyUnicode_AsUTF8(): 424.

        * ‘_PyUnicodeWriter_Init()’: replace
          ‘_PyUnicodeWriter_Init(&writer)’ with *note writer =
          PyUnicodeWriter_Create(0): 3b4.

        * ‘_PyUnicodeWriter_Finish()’: replace
          ‘_PyUnicodeWriter_Finish(&writer)’ with *note
          PyUnicodeWriter_Finish(writer): 3b7.

        * ‘_PyUnicodeWriter_Dealloc()’: replace
          ‘_PyUnicodeWriter_Dealloc(&writer)’ with *note
          PyUnicodeWriter_Discard(writer): 3b6.

        * ‘_PyUnicodeWriter_WriteChar()’: replace
          ‘_PyUnicodeWriter_WriteChar(&writer, ch)’ with *note
          PyUnicodeWriter_WriteChar(writer, ch): 3ba.

        * ‘_PyUnicodeWriter_WriteStr()’: replace
          ‘_PyUnicodeWriter_WriteStr(&writer, str)’ with *note
          PyUnicodeWriter_WriteStr(writer, str): 3bc.

        * ‘_PyUnicodeWriter_WriteSubstring()’: replace
          ‘_PyUnicodeWriter_WriteSubstring(&writer, str, start, end)’
          with *note PyUnicodeWriter_WriteSubstring(writer, str, start,
          end): 3bd.

        * ‘_PyUnicodeWriter_WriteASCIIString()’: replace
          ‘_PyUnicodeWriter_WriteASCIIString(&writer, str)’ with *note
          PyUnicodeWriter_WriteASCII(writer, str): 3b9.

        * ‘_PyUnicodeWriter_WriteLatin1String()’: replace
          ‘_PyUnicodeWriter_WriteLatin1String(&writer, str)’ with *note
          PyUnicodeWriter_WriteUTF8(writer, str): 3bf.

        * ‘_PyUnicodeWriter_Prepare()’: (no replacement).

        * ‘_PyUnicodeWriter_PrepareKind()’: (no replacement).

        * ‘_Py_HashPointer()’: use *note Py_HashPointer(): 425.

        * ‘_Py_fopen_obj()’: use *note Py_fopen(): 393.

     The pythoncapi-compat project(1) can be used to get these new
     public functions on Python 3.13 and older.  (Contributed by Victor
     Stinner in gh-128863(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/pythoncapi-compat/

   (2) https://github.com/python/cpython/issues/128863


File: python.info,  Node: Pending removal in future versions<2>,  Prev: Pending removal in Python 3 18<2>,  Up: Deprecated C APIs

1.1.10.9 Pending removal in future versions
...........................................

The following APIs are deprecated and will be removed, although there is
currently no date scheduled for their removal.

   * *note Py_TPFLAGS_HAVE_FINALIZE: 427.: Unneeded since Python 3.8.

   * *note PyErr_Fetch(): 428.: Use *note PyErr_GetRaisedException():
     429. instead.

   * *note PyErr_NormalizeException(): 42a.: Use *note
     PyErr_GetRaisedException(): 429. instead.

   * *note PyErr_Restore(): 42b.: Use *note PyErr_SetRaisedException():
     42c. instead.

   * *note PyModule_GetFilename(): 42d.: Use *note
     PyModule_GetFilenameObject(): 42e. instead.

   * *note PyOS_AfterFork(): 42f.: Use *note PyOS_AfterFork_Child():
     430. instead.

   * *note PySlice_GetIndicesEx(): 431.: Use *note PySlice_Unpack():
     432. and *note PySlice_AdjustIndices(): 433. instead.

   * *note PyUnicode_READY(): 434.: Unneeded since Python 3.12

   * ‘PyErr_Display()’: Use *note PyErr_DisplayException(): 435.
     instead.

   * ‘_PyErr_ChainExceptions()’: Use ‘_PyErr_ChainExceptions1()’
     instead.

   * ‘PyBytesObject.ob_shash’ member: call *note PyObject_Hash(): 436.
     instead.

   * Thread Local Storage (TLS) API:

        * *note PyThread_create_key(): 437.: Use *note
          PyThread_tss_alloc(): 438. instead.

        * *note PyThread_delete_key(): 439.: Use *note
          PyThread_tss_free(): 43a. instead.

        * *note PyThread_set_key_value(): 43b.: Use *note
          PyThread_tss_set(): 43c. instead.

        * *note PyThread_get_key_value(): 43d.: Use *note
          PyThread_tss_get(): 43e. instead.

        * *note PyThread_delete_key_value(): 43f.: Use *note
          PyThread_tss_delete(): 440. instead.

        * *note PyThread_ReInitTLS(): 441.: Unneeded since Python 3.7.


File: python.info,  Node: Build changes,  Next: Porting to Python 3 14,  Prev: C API changes,  Up: What’s new in Python 3 14

1.1.11 Build changes
--------------------

   * PEP 776(1): Emscripten is now an officially supported platform at
     tier 3(2).  As a part of this effort, more than 25 bugs in
     Emscripten libc(3) were fixed.  Emscripten now includes support for
     *note ctypes: 2e, *note termios: e7, and *note fcntl: 5d, as well
     as experimental support for the new *note default interactive
     shell: 443.  (Contributed by R. Hood Chatham in gh-127146(4),
     gh-127683(5), and gh-136931(6).)

   * Official Android binary releases are now provided on python.org(7).

   * GNU Autoconf 2.72 is now required to generate ‘configure’.
     (Contributed by Erlend Aasland in gh-115765(8).)

   * ‘wasm32-unknown-emscripten’ is now a PEP 11(9) tier 3 platform.
     (Contributed by R. Hood Chatham in gh-127146(10), gh-127683(11),
     and gh-136931(12).)

   * ‘#pragma’-based linking with ‘python3*.lib’ can now be switched off
     with *note Py_NO_LINK_LIB: 444.  (Contributed by Jean-Christophe
     Fillion-Robin in gh-82909(13).)

   * CPython now enables a set of recommended compiler options by
     default for improved security.  Use the *note -disable-safety: 445.
     ‘configure’ option to disable them, or the *note
     -enable-slower-safety: 446. option for a larger set of compiler
     options, albeit with a performance cost.

   * The ‘WITH_FREELISTS’ macro and ‘--without-freelists’ ‘configure’
     option have been removed.

   * The new ‘configure’ option *note -with-tail-call-interp: 172. may
     be used to enable the experimental tail call interpreter.  See
     *note A new type of interpreter: 14f. for further details.

   * To disable the new remote debugging support, use the *note
     -without-remote-debug: 170. ‘configure’ option.  This may be useful
     for security reasons.

   * iOS and macOS apps can now be configured to redirect ‘stdout’ and
     ‘stderr’ content to the system log.  (Contributed by Russell
     Keith-Magee in gh-127592(14).)

   * The iOS testbed is now able to stream test output while the test is
     running.  The testbed can also be used to run the test suite of
     projects other than CPython itself.  (Contributed by Russell
     Keith-Magee in gh-127592(15).)

* Menu:

* build-details.json: build-details json.
* Discontinuation of PGP signatures::
* Free-threaded Python is officially supported::
* Binary releases for the experimental just-in-time compiler::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0776/

   (2) https://peps.python.org/pep-0011/#tier-3

   (3) 
https://emscripten.org/docs/porting/emscripten-runtime-environment.html

   (4) https://github.com/python/cpython/issues/127146

   (5) https://github.com/python/cpython/issues/127683

   (6) https://github.com/python/cpython/issues/136931

   (7) https://www.python.org/downloads/android/

   (8) https://github.com/python/cpython/issues/115765

   (9) https://peps.python.org/pep-0011/

   (10) https://github.com/python/cpython/issues/127146

   (11) https://github.com/python/cpython/issues/127683

   (12) https://github.com/python/cpython/issues/136931

   (13) https://github.com/python/cpython/issues/82909

   (14) https://github.com/python/cpython/issues/127592

   (15) https://github.com/python/cpython/issues/127592


File: python.info,  Node: build-details json,  Next: Discontinuation of PGP signatures,  Up: Build changes

1.1.11.1 ‘build-details.json’
.............................

Installations of Python now contain a new file, ‘build-details.json’.
This is a static JSON document containing build details for CPython, to
allow for introspection without needing to run code.  This is helpful
for use-cases such as Python launchers, cross-compilation, and so on.

‘build-details.json’ must be installed in the platform-independent
standard library directory.  This corresponds to the *note “stdlib”:
449. *note sysconfig: e1. installation path, which can be found by
running ‘sysconfig.get_path('stdlib')’.

Vedi anche
..........

PEP 739(1) – ‘build-details.json’ 1.0 – a static description file for
Python build details

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0739/


File: python.info,  Node: Discontinuation of PGP signatures,  Next: Free-threaded Python is officially supported,  Prev: build-details json,  Up: Build changes

1.1.11.2 Discontinuation of PGP signatures
..........................................

PGP (Pretty Good Privacy) signatures will not be provided for releases
of Python 3.14 or future versions.  To verify CPython artifacts, users
must use Sigstore verification materials(1).  Releases have been signed
using Sigstore(2) since Python 3.11.

This change in release process was specified in PEP 761(3).

   ---------- Footnotes ----------

   (1) https://www.python.org/downloads/metadata/sigstore/

   (2) https://www.sigstore.dev/

   (3) https://peps.python.org/pep-0761/


File: python.info,  Node: Free-threaded Python is officially supported,  Next: Binary releases for the experimental just-in-time compiler,  Prev: Discontinuation of PGP signatures,  Up: Build changes

1.1.11.3 Free-threaded Python is officially supported
.....................................................

The free-threaded build of Python is now supported and no longer
experimental.  This is the start of phase II(1) where free-threaded
Python is officially supported but still optional.

The free-threading team are confident that the project is on the right
path, and appreciate the continued dedication from everyone working to
make free-threading ready for broader adoption across the Python
community.

With these recommendations and the acceptance of this PEP, the Python
developer community should broadly advertise that free-threading is a
supported Python build option now and into the future, and that it will
not be removed without a proper deprecation schedule.

Any decision to transition to phase III(2), with free-threading as the
default or sole build of Python is still undecided, and dependent on
many factors both within CPython itself and the community.  This
decision is for the future.

Vedi anche
..........

PEP 779(3)

PEP 779's acceptance(4)

   ---------- Footnotes ----------

   (1) https://discuss.python.org/t/37075

   (2) https://discuss.python.org/t/37075

   (3) https://peps.python.org/pep-0779/

   (4) https://discuss.python.org/t/84319/123


File: python.info,  Node: Binary releases for the experimental just-in-time compiler,  Prev: Free-threaded Python is officially supported,  Up: Build changes

1.1.11.4 Binary releases for the experimental just-in-time compiler
...................................................................

The official macOS and Windows release binaries now include an
'experimental' just-in-time (JIT) compiler.  Although it is 'not'
recommended for production use, it can be tested by setting *note
PYTHON_JIT=1: 44d. as an environment variable.  Downstream source builds
and redistributors can use the *note -enable-experimental-jit=yes-off:
44e. configuration option for similar behavior.

The JIT is at an early stage and still in active development.  As such,
the typical performance impact of enabling it can range from 10% slower
to 20% faster, depending on workload.  To aid in testing and evaluation,
a set of introspection functions has been provided in the *note
sys._jit: 293. namespace.  *note sys._jit.is_available(): 44f. can be
used to determine if the current executable supports JIT compilation,
while *note sys._jit.is_enabled(): 450. can be used to tell if JIT
compilation has been enabled for the current process.

Currently, the most significant missing functionality is that native
debuggers and profilers like ‘gdb’ and ‘perf’ are unable to unwind
through JIT frames (Python debuggers and profilers, like *note pdb: aa.
or *note profile: b4, continue to work without modification).
Free-threaded builds do not support JIT compilation.

Please report any bugs or major performance regressions that you
encounter!

Vedi anche
..........

PEP 744(1)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0744/


File: python.info,  Node: Porting to Python 3 14,  Next: Notable changes in 3 14 1,  Prev: Build changes,  Up: What’s new in Python 3 14

1.1.12 Porting to Python 3.14
-----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code.

* Menu:

* Changes in the Python API::
* Changes in annotations (PEP 649 and PEP 749): Changes in annotations PEP 649 and PEP 749.
* Changes in the C API::


File: python.info,  Node: Changes in the Python API,  Next: Changes in annotations PEP 649 and PEP 749,  Up: Porting to Python 3 14

1.1.12.1 Changes in the Python API
..................................

   * On Unix platforms other than macOS, 'forkserver' is now the default
     *note start method: 1d5. for *note multiprocessing: 98. and *note
     ProcessPoolExecutor: 1d6, instead of 'fork'.

     See *note (1): 1d3. and *note (2): 249. for details.

     If you encounter *note NameError: 452.s or pickling errors coming
     out of *note multiprocessing: 98. or *note concurrent.futures: 24,
     see the *note forkserver restrictions: 1d9.

     This change does not affect Windows or macOS, where *note “spawn”:
     1d8. remains the default start method.

   * *note functools.partial: 217. is now a method descriptor.  Wrap it
     in *note staticmethod(): 453. if you want to preserve the old
     behavior.  (Contributed by Serhiy Storchaka and Dominykas Grigonis
     in gh-121027(1).)

   * The *note garbage collector is now incremental: 152, which means
     that the behavior of *note gc.collect(): 1b3. changes slightly:

        * ‘gc.collect(1)’: Performs an increment of garbage collection,
          rather than collecting generation 1.

        * Other calls to ‘gc.collect()’ are unchanged.

   * The *note locale.nl_langinfo(): 454. function now temporarily sets
     the ‘LC_CTYPE’ locale in some cases.  This temporary change affects
     other threads.  (Contributed by Serhiy Storchaka in gh-69998(2).)

   * *note types.UnionType: 2a7. is now an alias for *note typing.Union:
     2a8, causing changes in some behaviors.  See *note above: 2a9. for
     more details.  (Contributed by Jelle Zijlstra in gh-105499(3).)

   * The runtime behavior of annotations has changed in various ways;
     see *note above: 145. for details.  While most code that interacts
     with annotations should continue to work, some undocumented details
     may behave differently.

   * As part of making the *note mimetypes: 93. CLI public, it now exits
     with ‘1’ on failure instead of ‘0’ and ‘2’ on incorrect
     command-line parameters instead of ‘1’.  Error messages are now
     printed to stderr.

   * The ‘\B’ pattern in regular expression now matches the empty string
     when given as the entire pattern, which may cause behavioural
     changes.

   * On FreeBSD, *note sys.platform: 291. no longer contains the major
     version number.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/121027

   (2) https://github.com/python/cpython/issues/69998

   (3) https://github.com/python/cpython/issues/105499


File: python.info,  Node: Changes in annotations PEP 649 and PEP 749,  Next: Changes in the C API,  Prev: Changes in the Python API,  Up: Porting to Python 3 14

1.1.12.2 Changes in annotations (
.................................

'PEP 649' and 'PEP 749')

This section contains guidance on changes that may be needed to
annotations or Python code that interacts with or introspects
annotations, due to the changes related to *note deferred evaluation of
annotations: 145.

In the majority of cases, working code from older versions of Python
will not require any changes.

* Menu:

* Implications for annotated code::
* Implications for readers of __annotations__::
* Related changes::
* from __future__ import annotations::


File: python.info,  Node: Implications for annotated code,  Next: Implications for readers of __annotations__,  Up: Changes in annotations PEP 649 and PEP 749

1.1.12.3 Implications for annotated code
........................................

If you define annotations in your code (for example, for use with a
static type checker), then this change probably does not affect you: you
can keep writing annotations the same way you did with previous versions
of Python.

You will likely be able to remove quoted strings in annotations, which
are frequently used for forward references.  Similarly, if you use ‘from
__future__ import annotations’ to avoid having to write strings in
annotations, you may well be able to remove that import once you support
only Python 3.14 and newer.  However, if you rely on third-party
libraries that read annotations, those libraries may need changes to
support unquoted annotations before they work as expected.


File: python.info,  Node: Implications for readers of __annotations__,  Next: Related changes,  Prev: Implications for annotated code,  Up: Changes in annotations PEP 649 and PEP 749

1.1.12.4 Implications for readers of ‘__annotations__’
......................................................

If your code reads the *note __annotations__: 458. attribute on objects,
you may want to make changes in order to support code that relies on
deferred evaluation of annotations.  For example, you may want to use
*note annotationlib.get_annotations(): 459. with the *note FORWARDREF:
15f. format, as the *note dataclasses: 33. module now does.

The external typing_extensions(1) package provides partial backports of
some of the functionality of the *note annotationlib: 6. module, such as
the *note Format: 230. enum and the *note get_annotations(): 459.
function.  These can be used to write cross-version code that takes
advantage of the new behavior in Python 3.14.

   ---------- Footnotes ----------

   (1) https://pypi.org/project/typing_extensions/


File: python.info,  Node: Related changes,  Next: from __future__ import annotations,  Prev: Implications for readers of __annotations__,  Up: Changes in annotations PEP 649 and PEP 749

1.1.12.5 Related changes
........................

The changes in Python 3.14 are designed to rework how ‘__annotations__’
works at runtime while minimizing breakage to code that contains
annotations in source code and to code that reads ‘__annotations__’.
However, if you rely on undocumented details of the annotation behavior
or on private functions in the standard library, there are many ways in
which your code may not work in Python 3.14.  To safeguard your code
against future changes, only use the documented functionality of the
*note annotationlib: 6. module.

In particular, do not read annotations directly from the namespace
dictionary attribute of type objects.  Use *note
annotationlib.get_annotate_from_class_namespace(): 45b. during class
construction and *note annotationlib.get_annotations(): 459. afterwards.

In previous releases, it was sometimes possible to access class
annotations from an instance of an annotated class.  This behavior was
undocumented and accidental, and will no longer work in Python 3.14.


File: python.info,  Node: from __future__ import annotations,  Prev: Related changes,  Up: Changes in annotations PEP 649 and PEP 749

1.1.12.6 ‘from __future__ import annotations’
.............................................

In Python 3.7, PEP 563(1) introduced the ‘from __future__ import
annotations’ *note future statement: 45d, which turns all annotations
into strings.

However, this statement is now deprecated and it is expected to be
removed in a future version of Python.  This removal will not happen
until after Python 3.13 reaches its end of life in 2029, being the last
version of Python without support for deferred evaluation of
annotations.

In Python 3.14, the behavior of code using ‘from __future__ import
annotations’ is unchanged.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0563/


File: python.info,  Node: Changes in the C API,  Prev: Changes in annotations PEP 649 and PEP 749,  Up: Porting to Python 3 14

1.1.12.7 Changes in the C API
.............................

   * *note Py_Finalize(): 45f. now deletes all interned strings.  This
     is backwards incompatible to any C extension that holds onto an
     interned string after a call to *note Py_Finalize(): 45f. and is
     then reused after a call to *note Py_Initialize(): 460.  Any issues
     arising from this behavior will normally result in crashes during
     the execution of the subsequent call to *note Py_Initialize(): 460.
     from accessing uninitialized memory.  To fix, use an address
     sanitizer to identify any use-after-free coming from an interned
     string and deallocate it during module shutdown.  (Contributed by
     Eddie Elizondo in gh-113601(1).)

   * The *note Unicode Exception Objects: 461. C API now raises a *note
     TypeError: 198. if its exception argument is not a *note
     UnicodeError: 462. object.  (Contributed by Bénédikt Tran in
     gh-127691(2).)

   * The interpreter internally avoids some reference count
     modifications when loading objects onto the operands stack by *note
     borrowing: 3d7. references when possible.  This can lead to smaller
     reference count values compared to previous Python versions.  C API
     extensions that checked *note Py_REFCNT(): 2cf. of ‘1’ to determine
     if an function argument is not referenced by any other code should
     instead use *note PyUnstable_Object_IsUniqueReferencedTemporary():
     3c7. as a safer replacement.

   * Private functions promoted to public C APIs:

        * ‘_PyBytes_Join()’: *note PyBytes_Join(): 383.

        * ‘_PyLong_IsNegative()’: *note PyLong_IsNegative(): 39c.

        * ‘_PyLong_IsPositive()’: *note PyLong_IsPositive(): 39b.

        * ‘_PyLong_IsZero()’: *note PyLong_IsZero(): 39d.

        * ‘_PyLong_Sign()’: *note PyLong_GetSign(): 39a.

        * ‘_PyUnicodeWriter_Dealloc()’: *note PyUnicodeWriter_Discard():
          3b6.

        * ‘_PyUnicodeWriter_Finish()’: *note PyUnicodeWriter_Finish():
          3b7.

        * ‘_PyUnicodeWriter_Init()’: use *note PyUnicodeWriter_Create():
          3b4.

        * ‘_PyUnicodeWriter_Prepare()’: (no replacement)

        * ‘_PyUnicodeWriter_PrepareKind()’: (no replacement)

        * ‘_PyUnicodeWriter_WriteChar()’: *note
          PyUnicodeWriter_WriteChar(): 3ba.

        * ‘_PyUnicodeWriter_WriteStr()’: *note
          PyUnicodeWriter_WriteStr(): 3bc.

        * ‘_PyUnicodeWriter_WriteSubstring()’: *note
          PyUnicodeWriter_WriteSubstring(): 3bd.

        * ‘_PyUnicode_EQ()’: *note PyUnicode_Equal(): 3b2.

        * ‘_PyUnicode_Equal()’: *note PyUnicode_Equal(): 3b2.

        * ‘_Py_GetConfig()’: *note PyConfig_Get(): 37c. and *note
          PyConfig_GetInt(): 384.

        * ‘_Py_HashBytes()’: *note Py_HashBuffer(): 395.

        * ‘_Py_fopen_obj()’: *note Py_fopen(): 393.

        * ‘PyMutex_IsLocked()’ : *note PyMutex_IsLocked(): 463.

     The pythoncapi-compat project(3) can be used to get most of these
     new functions on Python 3.13 and older.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/113601

   (2) https://github.com/python/cpython/issues/127691

   (3) https://github.com/python/pythoncapi-compat/


File: python.info,  Node: Notable changes in 3 14 1,  Prev: Porting to Python 3 14,  Up: What’s new in Python 3 14

1.1.13 Notable changes in 3.14.1
--------------------------------

   * Add *note PyUnstable_ThreadState_SetStackProtection(): 466. and
     *note PyUnstable_ThreadState_ResetStackProtection(): 467. functions
     to set the stack protection base address and stack protection size
     of a Python thread state.  (Contributed by Victor Stinner in
     gh-139653(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/139653


File: python.info,  Node: What’s New In Python 3 13,  Next: Novità in Python 3 12,  Prev: What’s new in Python 3 14,  Up: Novità in Python

1.2 What’s New In Python 3.13
=============================


Editors: Adam Turner and Thomas Wouters

This article explains the new features in Python 3.13, compared to 3.12.
Python 3.13 was released on October 7, 2024.  For full details, see the
*note changelog: 142.

Vedi anche
..........

PEP 719(1) – Python 3.13 Release Schedule

* Menu:

* Summary – Release Highlights::
* New Features::
* Other Language Changes::
* New Modules::
* Improved Modules::
* Optimizations: Optimizations<2>.
* Removed Modules And APIs::
* New Deprecations::
* CPython Bytecode Changes::
* C API Changes::
* Build Changes::
* Porting to Python 3.13: Porting to Python 3 13.
* Regression Test Changes::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0719/


File: python.info,  Node: Summary – Release Highlights,  Next: New Features,  Up: What’s New In Python 3 13

1.2.1 Summary – Release Highlights
----------------------------------

Python 3.13 is a stable release of the Python programming language, with
a mix of changes to the language, the implementation and the standard
library.  The biggest changes include a new *note interactive
interpreter: 46c., experimental support for running in a *note
free-threaded mode: 46d.( PEP 703(1)), and a *note Just-In-Time
compiler: 46e.( PEP 744(2)).

Error messages continue to improve, with tracebacks now highlighted in
color by default.  The *note locals(): 46f. builtin now has *note
defined semantics: 470. for changing the returned mapping, and type
parameters now support default values.

The library changes contain removal of deprecated APIs and modules, as
well as the usual improvements in user-friendliness and correctness.
Several legacy standard library modules have now *note been removed:
471.following their deprecation in Python 3.11 ( PEP 594(3)).

This article doesn’t attempt to provide a complete specification of all
new features, but instead gives a convenient overview.  For full details
refer to the documentation, such as the *note Library Reference: 149.
and *note Language Reference: 14a.  To understand the complete
implementation and design rationale for a change, refer to the PEP for a
particular new feature; but note that PEPs usually are not kept
up-to-date once a feature has been fully implemented.  See *note Porting
to Python 3.13: 472. for guidance on upgrading from earlier versions of
Python.

__________________________________________________________________

Interpreter improvements:

   * A greatly improved *note interactive interpreter: 46c. and *note
     improved error messages: 473.

   * PEP 667(4): The *note locals(): 46f. builtin now has *note defined
     semantics: 470. when mutating the returned mapping.  Python
     debuggers and similar tools may now more reliably update local
     variables in optimized scopes even during concurrent code
     execution.

   * PEP 703(5): CPython 3.13 has experimental support for running with
     the *note global interpreter lock: 474. disabled.  See *note
     Free-threaded CPython: 46d. for more details.

   * PEP 744(6): A basic *note JIT compiler: 46e. was added.  It is
     currently disabled by default (though we may turn it on later).
     Performance improvements are modest – we expect to improve this
     over the next few releases.

   * Color support in the new *note interactive interpreter: 46c, as
     well as in *note tracebacks: 473. and *note doctest: 475. output.
     This can be disabled through the *note PYTHON_COLORS: 476. and
     NO_COLOR(7) environment variables.

Python data model improvements:

   * *note __static_attributes__: 477. stores the names of attributes
     accessed through ‘self.X’ in any function in a class body.

   * *note __firstlineno__: 478. records the first line number of a
     class definition.

Significant improvements in the standard library:

   * Add a new *note PythonFinalizationError: 479. exception, raised
     when an operation is blocked during *note finalization: 47a.

   * The *note argparse: 7. module now supports deprecating command-line
     options, positional arguments, and subcommands.

   * The new functions *note base64.z85encode(): 47b. and *note
     base64.z85decode(): 47c. support encoding and decoding Z85 data(8).

   * The *note copy: 29. module now has a *note copy.replace(): 1c0.
     function, with support for many builtin types and any class
     defining the *note __replace__(): 47d. method.

   * The new *note dbm.sqlite3: 39. module is now the default *note dbm:
     35. backend.

   * The *note os: a5. module has a *note suite of new functions: 47e.
     for working with Linux’s timer notification file descriptors.

   * The *note random: bd. module now has a *note command-line
     interface: 47f.

Security improvements:

   * *note ssl.create_default_context(): 480. sets *note
     ssl.VERIFY_X509_PARTIAL_CHAIN: 481. and *note
     ssl.VERIFY_X509_STRICT: 482. as default flags.

C API improvements:

   * The *note Py_mod_gil: 483. slot is now used to indicate that an
     extension module supports running with the *note GIL: 164.
     disabled.

   * The *note PyTime C API: 484. has been added, providing access to
     system clocks.

   * *note PyMutex: 485. is a new lightweight mutex that occupies a
     single byte.

   * There is a new *note suite of functions: 486. for generating PEP
     669(9) monitoring events in the C API.

New typing features:

   * PEP 696(10): Type parameters (*note typing.TypeVar: 487, *note
     typing.ParamSpec: 488, and *note typing.TypeVarTuple: 489.) now
     support defaults.

   * PEP 702(11): The new *note warnings.deprecated(): 48a. decorator
     adds support for marking deprecations in the type system and at
     runtime.

   * PEP 705(12): *note typing.ReadOnly: 48b. can be used to mark an
     item of a *note typing.TypedDict: 332. as read-only for type
     checkers.

   * PEP 742(13): *note typing.TypeIs: 48c. provides more intuitive type
     narrowing behavior, as an alternative to *note typing.TypeGuard:
     48d.

Platform support:

   * PEP 730(14): Apple’s iOS is now an *note officially supported
     platform: 48e, at tier 3(15).

   * PEP 738(16): Android is now an *note officially supported platform:
     48e, at tier 3(17).

   * ‘wasm32-wasi’ is now supported as a tier 2(18) platform.

   * ‘wasm32-emscripten’ is no longer an officially supported platform.

Important removals:

   * *note PEP 594: 471.: The remaining 19 «dead batteries» (legacy
     stdlib modules) have been removed from the standard library:
     ‘aifc’, ‘audioop’, ‘cgi’, ‘cgitb’, ‘chunk’, ‘crypt’, ‘imghdr’,
     ‘mailcap’, ‘msilib’, ‘nis’, ‘nntplib’, ‘ossaudiodev’, ‘pipes’,
     ‘sndhdr’, ‘spwd’, ‘sunau’, ‘telnetlib’, ‘uu’ and ‘xdrlib’.

   * Remove the ‘2to3’ tool and ‘lib2to3’ module (deprecated in Python
     3.11).

   * Remove the ‘tkinter.tix’ module (deprecated in Python 3.6).

   * Remove the ‘locale.resetlocale()’ function.

   * Remove the ‘typing.io’ and ‘typing.re’ namespaces.

   * Remove chained *note classmethod: 48f. descriptors.

Release schedule changes:

PEP 602(19) («Annual Release Cycle for Python») has been updated to
extend the full support (“bugfix”) period for new releases to two years.
This updated policy means that:

   * Python 3.9–3.12 have one and a half years of full support, followed
     by three and a half years of security fixes.

   * Python 3.13 and later have two years of full support, followed by
     three years of security fixes.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0703/

   (2) https://peps.python.org/pep-0744/

   (3) https://peps.python.org/pep-0594/

   (4) https://peps.python.org/pep-0667/

   (5) https://peps.python.org/pep-0703/

   (6) https://peps.python.org/pep-0744/

   (7) https://no-color.org/

   (8) https://rfc.zeromq.org/spec/32/

   (9) https://peps.python.org/pep-0669/

   (10) https://peps.python.org/pep-0696/

   (11) https://peps.python.org/pep-0702/

   (12) https://peps.python.org/pep-0705/

   (13) https://peps.python.org/pep-0742/

   (14) https://peps.python.org/pep-0730/

   (15) https://peps.python.org/pep-0011/#tier-3

   (16) https://peps.python.org/pep-0738/

   (17) https://peps.python.org/pep-0011/#tier-3

   (18) https://peps.python.org/pep-0011/#tier-2

   (19) https://peps.python.org/pep-0602/


File: python.info,  Node: New Features,  Next: Other Language Changes,  Prev: Summary – Release Highlights,  Up: What’s New In Python 3 13

1.2.2 New Features
------------------

* Menu:

* A better interactive interpreter::
* Improved error messages: Improved error messages<2>.
* Free-threaded CPython::
* An experimental just-in-time (JIT) compiler: An experimental just-in-time JIT compiler.
* Defined mutation semantics for locals(): Defined mutation semantics for locals.
* Support for mobile platforms::


File: python.info,  Node: A better interactive interpreter,  Next: Improved error messages<2>,  Up: New Features

1.2.2.1 A better interactive interpreter
........................................

Python now uses a new *note interactive: 1b5. shell by default, based on
code from the PyPy project(1).  When the user starts the *note REPL:
492. from an interactive terminal, the following new features are now
supported:

   * Multiline editing with history preservation.

   * Direct support for REPL-specific commands like ‘help’, ‘exit’, and
     ‘quit’, without the need to call them as functions.

   * Prompts and tracebacks with *note color enabled by default: 1b7.

   * Interactive help browsing using ‘F1’ with a separate command
     history.

   * History browsing using ‘F2’ that skips output as well as the *note
     >>>: 493. and *note …: 494. prompts.

   * «Paste mode» with ‘F3’ that makes pasting larger blocks of code
     easier (press ‘F3’ again to return to the regular prompt).

To disable the new interactive shell, set the *note PYTHON_BASIC_REPL:
1b6. environment variable.  For more on interactive mode, see *note
Modalità Interattiva: 495.

(Contributed by Pablo Galindo Salgado, Łukasz Langa, and Lysandros
Nikolaou in gh-111201(2) based on code from the PyPy project.  Windows
support contributed by Dino Viehland and Anthony Shaw.)

   ---------- Footnotes ----------

   (1) https://pypy.org/

   (2) https://github.com/python/cpython/issues/111201


File: python.info,  Node: Improved error messages<2>,  Next: Free-threaded CPython,  Prev: A better interactive interpreter,  Up: New Features

1.2.2.2 Improved error messages
...............................

   * The interpreter now uses color by default when displaying
     tracebacks in the terminal.  This feature *note can be controlled:
     1b7. via the new *note PYTHON_COLORS: 476. environment variable as
     well as the canonical NO_COLOR(1) and FORCE_COLOR(2) environment
     variables.  (Contributed by Pablo Galindo Salgado in gh-112730(3).)

   * A common mistake is to write a script with the same name as a
     standard library module.  When this results in errors, we now
     display a more helpful error message:

          $ python random.py
          Traceback (most recent call last):
            File "/home/me/random.py", line 1, in <module>
              import random
            File "/home/me/random.py", line 3, in <module>
              print(random.randint(5))
                    ^^^^^^^^^^^^^^
          AttributeError: module 'random' has no attribute 'randint' (consider renaming '/home/me/random.py' since it has the same name as the standard library module named 'random' and prevents importing that standard library module)

     Similarly, if a script has the same name as a third-party module
     that it attempts to import and this results in errors, we also
     display a more helpful error message:

          $ python numpy.py
          Traceback (most recent call last):
            File "/home/me/numpy.py", line 1, in <module>
              import numpy as np
            File "/home/me/numpy.py", line 3, in <module>
              np.array([1, 2, 3])
              ^^^^^^^^
          AttributeError: module 'numpy' has no attribute 'array' (consider renaming '/home/me/numpy.py' if it has the same name as a library you intended to import)

     (Contributed by Shantanu Jain in gh-95754(4).)

   * The error message now tries to suggest the correct keyword argument
     when an incorrect keyword argument is passed to a function.

          >>> "Better error messages!".split(max_split=1)
          Traceback (most recent call last):
            File "<python-input-0>", line 1, in <module>
              "Better error messages!".split(max_split=1)
              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
          TypeError: split() got an unexpected keyword argument 'max_split'. Did you mean 'maxsplit'?

     (Contributed by Pablo Galindo Salgado and Shantanu Jain in
     gh-107944(5).)

   ---------- Footnotes ----------

   (1) https://no-color.org/

   (2) https://force-color.org/

   (3) https://github.com/python/cpython/issues/112730

   (4) https://github.com/python/cpython/issues/95754

   (5) https://github.com/python/cpython/issues/107944


File: python.info,  Node: Free-threaded CPython,  Next: An experimental just-in-time JIT compiler,  Prev: Improved error messages<2>,  Up: New Features

1.2.2.3 Free-threaded CPython
.............................

CPython now has experimental support for running in a free-threaded
mode, with the *note global interpreter lock: 474. (GIL) disabled.  This
is an experimental feature and therefore is not enabled by default.  The
free-threaded mode requires a different executable, usually called
‘python3.13t’ or ‘python3.13t.exe’.  Pre-built binaries marked as
'free-threaded' can be installed as part of the official *note Windows:
498. and *note macOS: 499. installers, or CPython can be built from
source with the *note -disable-gil: 49a. option.

Free-threaded execution allows for full utilization of the available
processing power by running threads in parallel on available CPU cores.
While not all software will benefit from this automatically, programs
designed with threading in mind will run faster on multi-core hardware.
'The free-threaded mode is experimental' and work is ongoing to improve
it: expect some bugs and a substantial single-threaded performance hit.
Free-threaded builds of CPython support optionally running with the GIL
enabled at runtime using the environment variable *note PYTHON_GIL: 49b.
or the command-line option *note -X gil=1: 16f.

To check if the current interpreter supports free-threading, *note
python -VV: 49c. and *note sys.version: 49d. contain «experimental
free-threading build».  The new ‘sys._is_gil_enabled()’ function can be
used to check whether the GIL is actually disabled in the running
process.

C-API extension modules need to be built specifically for the
free-threaded build.  Extensions that support running with the *note
GIL: 164. disabled should use the *note Py_mod_gil: 483. slot.
Extensions using single-phase init should use *note
PyUnstable_Module_SetGIL(): 49e. to indicate whether they support
running with the GIL disabled.  Importing C extensions that don’t use
these mechanisms will cause the GIL to be enabled, unless the GIL was
explicitly disabled with the *note PYTHON_GIL: 49b. environment variable
or the *note -X gil=0: 16f. option.  pip 24.1 or newer is required to
install packages with C extensions in the free-threaded build.

This work was made possible thanks to many individuals and
organizations, including the large community of contributors to Python
and third-party projects to test and enable free-threading support.
Notable contributors include: Sam Gross, Ken Jin, Donghee Na, Itamar
Oren, Matt Page, Brett Simmers, Dino Viehland, Carl Meyer, Nathan
Goldbaum, Ralf Gommers, Lysandros Nikolaou, and many others.  Many of
these contributors are employed by Meta, which has provided significant
engineering resources to support this project.

Vedi anche
..........

PEP 703(1) «Making the Global Interpreter Lock Optional in CPython»
contains rationale and information surrounding this work.

Porting Extension Modules to Support Free-Threading(2): A
community-maintained porting guide for extension authors.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0703/

   (2) https://py-free-threading.github.io/porting/


File: python.info,  Node: An experimental just-in-time JIT compiler,  Next: Defined mutation semantics for locals,  Prev: Free-threaded CPython,  Up: New Features

1.2.2.4 An experimental just-in-time (JIT) compiler
...................................................

When CPython is configured and built using the
‘--enable-experimental-jit’ option, a just-in-time (JIT) compiler is
added which may speed up some Python programs.  On Windows, use
‘PCbuild/build.bat --experimental-jit’ to enable the JIT or
‘--experimental-jit-interpreter’ to enable the Tier 2 interpreter.
Build requirements and further supporting information are contained
at(1) ‘Tools/jit/README.md’.

The ‘--enable-experimental-jit’ option takes these (optional) values,
defaulting to ‘yes’ if ‘--enable-experimental-jit’ is present without
the optional value.

   * ‘no’: Disable the entire Tier 2 and JIT pipeline.

   * ‘yes’: Enable the JIT. To disable the JIT at runtime, pass the
     environment variable ‘PYTHON_JIT=0’.

   * ‘yes-off’: Build the JIT but disable it by default.  To enable the
     JIT at runtime, pass the environment variable ‘PYTHON_JIT=1’.

   * ‘interpreter’: Enable the Tier 2 interpreter but disable the JIT.
     The interpreter can be disabled by running with ‘PYTHON_JIT=0’.

The internal architecture is roughly as follows:

   * We start with specialized 'Tier 1 bytecode'.  See *note What’s new
     in 3.11: 4a0. for details.

   * When the Tier 1 bytecode gets hot enough, it gets translated to a
     new purely internal intermediate representation (IR), called the
     'Tier 2 IR', and sometimes referred to as micro-ops («uops»).

   * The Tier 2 IR uses the same stack-based virtual machine as Tier 1,
     but the instruction format is better suited to translation to
     machine code.

   * We have several optimization passes for Tier 2 IR, which are
     applied before it is interpreted or translated to machine code.

   * There is a Tier 2 interpreter, but it is mostly intended for
     debugging the earlier stages of the optimization pipeline.  The
     Tier 2 interpreter can be enabled by configuring Python with
     ‘--enable-experimental-jit=interpreter’.

   * When the JIT is enabled, the optimized Tier 2 IR is translated to
     machine code, which is then executed.

   * The machine code translation process uses a technique called
     'copy-and-patch'.  It has no runtime dependencies, but there is a
     new build-time dependency on LLVM.

Vedi anche
..........

PEP 744(2)

(JIT by Brandt Bucher, inspired by a paper by Haoran Xu and Fredrik
Kjolstad.  Tier 2 IR by Mark Shannon and Guido van Rossum.  Tier 2
optimizer by Ken Jin.)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/blob/main/Tools/jit/README.md

   (2) https://peps.python.org/pep-0744/


File: python.info,  Node: Defined mutation semantics for locals,  Next: Support for mobile platforms,  Prev: An experimental just-in-time JIT compiler,  Up: New Features

1.2.2.5 Defined mutation semantics for ‘locals()’
.................................................

Historically, the expected result of mutating the return value of *note
locals(): 46f. has been left to individual Python implementations to
define.  Starting from Python 3.13, PEP 667(1) standardises the
historical behavior of CPython for most code execution scopes, but
changes *note optimized scopes: 4a2. (functions, generators, coroutines,
comprehensions, and generator expressions) to explicitly return
independent snapshots of the currently assigned local variables,
including locally referenced nonlocal variables captured in closures.

This change to the semantics of *note locals(): 46f. in optimized scopes
also affects the default behavior of code execution functions that
implicitly target ‘locals()’ if no explicit namespace is provided (such
as *note exec(): 4a3. and *note eval(): 4a4.).  In previous versions,
whether or not changes could be accessed by calling ‘locals()’ after
calling the code execution function was implementation-dependent.  In
CPython specifically, such code would typically appear to work as
desired, but could sometimes fail in optimized scopes based on other
code (including debuggers and code execution tracing tools) potentially
resetting the shared snapshot in that scope.  Now, the code will always
run against an independent snapshot of the local variables in optimized
scopes, and hence the changes will never be visible in subsequent calls
to ‘locals()’.  To access the changes made in these cases, an explicit
namespace reference must now be passed to the relevant function.
Alternatively, it may make sense to update affected code to use a higher
level code execution API that returns the resulting code execution
namespace (e.g.  *note runpy.run_path(): 4a5. when executing Python
files from disk).

To ensure debuggers and similar tools can reliably update local
variables in scopes affected by this change, *note FrameType.f_locals:
4a6. now returns a write-through proxy to the frame’s local and locally
referenced nonlocal variables in these scopes, rather than returning an
inconsistently updated shared ‘dict’ instance with undefined runtime
semantics.

See PEP 667(2) for more details, including related C API changes and
deprecations.  Porting notes are also provided below for the affected
*note Python APIs: 4a7. and *note C APIs: 4a8.

(PEP and implementation contributed by Mark Shannon and Tian Gao in
gh-74929(3).  Documentation updates provided by Guido van Rossum and
Alyssa Coghlan.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0667/

   (2) https://peps.python.org/pep-0667/

   (3) https://github.com/python/cpython/issues/74929


File: python.info,  Node: Support for mobile platforms,  Prev: Defined mutation semantics for locals,  Up: New Features

1.2.2.6 Support for mobile platforms
....................................

PEP 730(1): iOS is now a PEP 11(2) supported platform, with the
‘arm64-apple-ios’ and ‘arm64-apple-ios-simulator’ targets at tier 3
(iPhone and iPad devices released after 2013 and the Xcode iOS simulator
running on Apple silicon hardware, respectively).
‘x86_64-apple-ios-simulator’ (the Xcode iOS simulator running on older
‘x86_64’ hardware) is not a tier 3 supported platform, but will have
best-effort support.  (PEP written and implementation contributed by
Russell Keith-Magee in gh-114099(3).)

PEP 738(4): Android is now a PEP 11(5) supported platform, with the
‘aarch64-linux-android’ and ‘x86_64-linux-android’ targets at tier 3.
The 32-bit targets ‘arm-linux-androideabi’ and ‘i686-linux-android’ are
not tier 3 supported platforms, but will have best-effort support.  (PEP
written and implementation contributed by Malcolm Smith in
gh-116622(6).)

Vedi anche
..........

PEP 730(7), PEP 738(8)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0730/

   (2) https://peps.python.org/pep-0011/

   (3) https://github.com/python/cpython/issues/114099

   (4) https://peps.python.org/pep-0738/

   (5) https://peps.python.org/pep-0011/

   (6) https://github.com/python/cpython/issues/116622

   (7) https://peps.python.org/pep-0730/

   (8) https://peps.python.org/pep-0738/


File: python.info,  Node: Other Language Changes,  Next: New Modules,  Prev: New Features,  Up: What’s New In Python 3 13

1.2.3 Other Language Changes
----------------------------

   * The compiler now strips common leading whitespace from every line
     in a docstring.  This reduces the size of the *note bytecode cache:
     4ab. (such as ‘.pyc’ files), with reductions in file size of around
     5%, for example in ‘sqlalchemy.orm.session’ from SQLAlchemy 2.0.
     This change affects tools that use docstrings, such as *note
     doctest: 3e.

          >>> def spam():
          ...     """
          ...         This is a docstring with
          ...           leading whitespace.
          ...
          ...         It even has multiple paragraphs!
          ...     """
          ...
          >>> spam.__doc__
          '\nThis is a docstring with\n  leading whitespace.\n\nIt even has multiple paragraphs!\n'

     (Contributed by Inada Naoki in gh-81283(1).)

   * *note Annotation scopes: 4ac. within class scopes can now contain
     lambdas and comprehensions.  Comprehensions that are located within
     class scopes are not inlined into their parent scope.

          class C[T]:
              type Alias = lambda: T

     (Contributed by Jelle Zijlstra in gh-109118(2) and gh-118160(3).)

   * *note Future statements: 45d. are no longer triggered by relative
     imports of the *note __future__: 0. module, meaning that statements
     of the form ‘from .__future__ import ...’ are now simply standard
     relative imports, with no special features activated.  (Contributed
     by Jeremiah Gabriel Pascual in gh-118216(4).)

   * *note global: 4ad. declarations are now permitted in *note except:
     1ab. blocks when that global is used in the *note else: 17c. block.
     Previously this raised an erroneous *note SyntaxError: 18e.
     (Contributed by Irit Katriel in gh-111123(5).)

   * Add *note PYTHON_FROZEN_MODULES: 4ae, a new environment variable
     that determines whether frozen modules are ignored by the import
     machinery, equivalent to the *note -X frozen_modules: 16f.
     command-line option.  (Contributed by Yilei Yang in gh-111374(6).)

   * Add *note support for the perf profiler: 4af. working without frame
     pointers(7) through the new environment variable *note
     PYTHON_PERF_JIT_SUPPORT: 4b0. and command-line option *note -X
     perf_jit: 16f.  (Contributed by Pablo Galindo in gh-118518(8).)

   * The location of a ‘.python_history’ file can be changed via the new
     *note PYTHON_HISTORY: 4b1. environment variable.  (Contributed by
     Levi Sabah, Zackery Spytz and Hugo van Kemenade in gh-73965(9).)

   * Classes have a new *note __static_attributes__: 477. attribute.
     This is populated by the compiler with a tuple of the class’s
     attribute names which are assigned through ‘self.<name>’ from any
     function in its body.  (Contributed by Irit Katriel in
     gh-115775(10).)

   * The compiler now creates a ‘__firstlineno__’ attribute on classes
     with the line number of the first line of the class definition.
     (Contributed by Serhiy Storchaka in gh-118465(11).)

   * The *note exec(): 4a3. and *note eval(): 4a4. builtins now accept
     the 'globals' and 'locals' arguments as keywords.  (Contributed by
     Raphael Gaschignard in gh-105879(12))

   * The *note compile(): 4b2. builtin now accepts a new flag,
     ‘ast.PyCF_OPTIMIZED_AST’, which is similar to ‘ast.PyCF_ONLY_AST’
     except that the returned AST is optimized according to the value of
     the 'optimize' argument.  (Contributed by Irit Katriel in
     gh-108113(13)).

   * Add a *note __name__: 4b3. attribute on *note property: 4b4.
     objects.  (Contributed by Eugene Toder in gh-101860(14).)

   * Add *note PythonFinalizationError: 479, a new exception derived
     from *note RuntimeError: 244. and used to signal when operations
     are blocked during *note finalization: 47a.  The following
     callables now raise ‘PythonFinalizationError’, instead of *note
     RuntimeError: 244.:

        * *note _thread.start_new_thread(): 4b5.

        * *note os.fork(): 4b6.

        * *note os.forkpty(): 4b7.

        * *note subprocess.Popen: 4b8.

     (Contributed by Victor Stinner in gh-114570(15).)

   * Allow the 'count' argument of *note str.replace(): 4b9. to be a
     keyword.  (Contributed by Hugo van Kemenade in gh-106487(16).)

   * Many functions now emit a warning if a boolean value is passed as a
     file descriptor argument.  This can help catch some errors earlier.
     (Contributed by Serhiy Storchaka in gh-82626(17).)

   * Added ‘name’ and ‘mode’ attributes for compressed and archived
     file-like objects in the *note bz2: 14, *note lzma: 8e, *note
     tarfile: e4, and *note zipfile: 137. modules.  (Contributed by
     Serhiy Storchaka in gh-115961(18).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/81283

   (2) https://github.com/python/cpython/issues/109118

   (3) https://github.com/python/cpython/issues/118160

   (4) https://github.com/python/cpython/issues/118216

   (5) https://github.com/python/cpython/issues/111123

   (6) https://github.com/python/cpython/issues/111374

   (7) https://en.wikipedia.org/wiki/Call_stack

   (8) https://github.com/python/cpython/issues/118518

   (9) https://github.com/python/cpython/issues/73965

   (10) https://github.com/python/cpython/issues/115775

   (11) https://github.com/python/cpython/issues/118465

   (12) https://github.com/python/cpython/issues/105879

   (13) https://github.com/python/cpython/issues/108113

   (14) https://github.com/python/cpython/issues/101860

   (15) https://github.com/python/cpython/issues/114570

   (16) https://github.com/python/cpython/issues/106487

   (17) https://github.com/python/cpython/issues/82626

   (18) https://github.com/python/cpython/issues/115961


File: python.info,  Node: New Modules,  Next: Improved Modules,  Prev: Other Language Changes,  Up: What’s New In Python 3 13

1.2.4 New Modules
-----------------

   * *note dbm.sqlite3: 39.: An SQLite backend for *note dbm: 35.
     (Contributed by Raymond Hettinger and Erlend E. Aasland in
     gh-100414(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100414


File: python.info,  Node: Improved Modules,  Next: Optimizations<2>,  Prev: New Modules,  Up: What’s New In Python 3 13

1.2.5 Improved Modules
----------------------

* Menu:

* argparse: argparse<3>.
* array::
* ast: ast<3>.
* asyncio: asyncio<4>.
* base64: base64<2>.
* compileall::
* concurrent.futures: concurrent futures<2>.
* configparser: configparser<2>.
* copy::
* ctypes: ctypes<2>.
* dbm::
* dis: dis<2>.
* doctest::
* email: email<2>.
* enum::
* fractions: fractions<2>.
* glob::
* importlib::
* io: io<3>.
* ipaddress::
* itertools: itertools<2>.
* marshal::
* math: math<2>.
* mimetypes: mimetypes<2>.
* mmap::
* multiprocessing: multiprocessing<2>.
* os: os<2>.
* os.path: os path<2>.
* pathlib: pathlib<4>.
* pdb: pdb<3>.
* queue::
* random::
* re: re<2>.
* shutil::
* site::
* sqlite3: sqlite3<2>.
* ssl: ssl<2>.
* statistics::
* subprocess::
* sys: sys<2>.
* tempfile::
* time::
* tkinter: tkinter<2>.
* traceback::
* types: types<2>.
* typing: typing<2>.
* unicodedata: unicodedata<2>.
* venv::
* warnings::
* xml::
* zipimport::


File: python.info,  Node: argparse<3>,  Next: array,  Up: Improved Modules

1.2.5.1 argparse
................

   * Add the 'deprecated' parameter to the *note add_argument(): 4bd.
     and ‘add_parser()’ methods, to enable deprecating command-line
     options, positional arguments, and subcommands.  (Contributed by
     Serhiy Storchaka in gh-83648(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/83648


File: python.info,  Node: array,  Next: ast<3>,  Prev: argparse<3>,  Up: Improved Modules

1.2.5.2 array
.............

   * Add the ‘'w'’ type code (‘Py_UCS4’) for Unicode characters.  It
     should be used instead of the deprecated ‘'u'’ type code.
     (Contributed by Inada Naoki in gh-80480(1).)

   * Register *note array.array: 4bf. as a *note MutableSequence: 4c0.
     by implementing the *note clear(): 4c1. method.  (Contributed by
     Mike Zimin in gh-114894(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/80480

   (2) https://github.com/python/cpython/issues/114894


File: python.info,  Node: ast<3>,  Next: asyncio<4>,  Prev: array,  Up: Improved Modules

1.2.5.3 ast
...........

   * The constructors of node types in the *note ast: 9. module are now
     stricter in the arguments they accept, with more intuitive behavior
     when arguments are omitted.

     If an optional field on an AST node is not included as an argument
     when constructing an instance, the field will now be set to ‘None’.
     Similarly, if a list field is omitted, that field will now be set
     to an empty list, and if an ‘expr_context’ field is omitted, it
     defaults to *note Load(): 4c3.  (Previously, in all cases, the
     attribute would be missing on the newly constructed AST node
     instance.)

     In all other cases, where a required argument is omitted, the node
     constructor will emit a *note DeprecationWarning: 1a3.  This will
     raise an exception in Python 3.15.  Similarly, passing a keyword
     argument to the constructor that does not map to a field on the AST
     node is now deprecated, and will raise an exception in Python 3.15.

     These changes do not apply to user-defined subclasses of *note
     ast.AST: 4c4. unless the class opts in to the new behavior by
     defining the *note AST._field_types: 4c5. mapping.

     (Contributed by Jelle Zijlstra in gh-105858(1), gh-117486(2), and
     gh-118851(3).)

   * *note ast.parse(): 1c2. now accepts an optional argument 'optimize'
     which is passed on to *note compile(): 4b2.  This makes it possible
     to obtain an optimized AST. (Contributed by Irit Katriel in
     gh-108113(4).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/105858

   (2) https://github.com/python/cpython/issues/117486

   (3) https://github.com/python/cpython/issues/118851

   (4) https://github.com/python/cpython/issues/108113


File: python.info,  Node: asyncio<4>,  Next: base64<2>,  Prev: ast<3>,  Up: Improved Modules

1.2.5.4 asyncio
...............

   * *note asyncio.as_completed(): 4c7. now returns an object that is
     both an *note asynchronous iterator: 4c8. and a plain *note
     iterator: 4c9. of *note awaitables: 4ca.  The awaitables yielded by
     asynchronous iteration include original task or future objects that
     were passed in, making it easier to associate results with the
     tasks being completed.  (Contributed by Justin Arthur in
     gh-77714(1).)

   * *note asyncio.loop.create_unix_server(): 4cb. will now
     automatically remove the Unix socket when the server is closed.
     (Contributed by Pierre Ossman in gh-111246(2).)

   * *note DatagramTransport.sendto(): 4cc. will now send zero-length
     datagrams if called with an empty bytes object.  The transport flow
     control also now accounts for the datagram header when calculating
     the buffer size.  (Contributed by Jamie Phan in gh-115199(3).)

   * Add *note Queue.shutdown: 4cd. and *note QueueShutDown: 4ce. to
     manage queue termination.  (Contributed by Laurie Opperman and Yves
     Duprat in gh-104228(4).)

   * Add the *note Server.close_clients(): 4cf. and *note
     Server.abort_clients(): 4d0. methods, which more forcefully close
     an asyncio server.  (Contributed by Pierre Ossman in gh-113538(5).)

   * Accept a tuple of separators in *note StreamReader.readuntil():
     4d1, stopping when any one of them is encountered.  (Contributed by
     Bruce Merry in gh-81322(6).)

   * Improve the behavior of *note TaskGroup: 4d2. when an external
     cancellation collides with an internal cancellation.  For example,
     when two task groups are nested and both experience an exception in
     a child task simultaneously, it was possible that the outer task
     group would hang, because its internal cancellation was swallowed
     by the inner task group.

     In the case where a task group is cancelled externally and also
     must raise an *note ExceptionGroup: 4d3, it will now call the
     parent task’s *note cancel(): 4d4. method.  This ensures that a
     *note CancelledError: 4d5. will be raised at the next *note await:
     18d, so the cancellation is not lost.

     An added benefit of these changes is that task groups now preserve
     the cancellation count (*note cancelling(): 4d6.).

     In order to handle some corner cases, *note uncancel(): 4d7. may
     now reset the undocumented ‘_must_cancel’ flag when the
     cancellation count reaches zero.

     (Inspired by an issue reported by Arthur Tacca in gh-116720(7).)

   * When *note TaskGroup.create_task(): 1cb. is called on an inactive
     *note TaskGroup: 4d2, the given coroutine will be closed (which
     prevents a *note RuntimeWarning: 4d8. about the given coroutine
     being never awaited).  (Contributed by Arthur Tacca and Jason Zhang
     in gh-115957(8).)

   * The function and methods named ‘create_task’ have received a new
     ‘**kwargs’ argument that is passed through to the task constructor.
     This change was accidentally added in 3.13.3, and broke the API
     contract for custom task factories.  Several third-party task
     factories implemented workarounds for this.  In 3.13.4 and later
     releases the old factory contract is honored once again (until
     3.14).  To keep the workarounds working, the extra ‘**kwargs’
     argument still allows passing additional keyword arguments to *note
     Task: 1c7. and to custom task factories.

     This affects the following function and methods: *note
     asyncio.create_task(): 1c9, *note asyncio.loop.create_task(): 1ca,
     *note asyncio.TaskGroup.create_task(): 1cb.  (Contributed by Thomas
     Grainger in gh-128307(9).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/77714

   (2) https://github.com/python/cpython/issues/111246

   (3) https://github.com/python/cpython/issues/115199

   (4) https://github.com/python/cpython/issues/104228

   (5) https://github.com/python/cpython/issues/113538

   (6) https://github.com/python/cpython/issues/81322

   (7) https://github.com/python/cpython/issues/116720

   (8) https://github.com/python/cpython/issues/115957

   (9) https://github.com/python/cpython/issues/128307


File: python.info,  Node: base64<2>,  Next: compileall,  Prev: asyncio<4>,  Up: Improved Modules

1.2.5.5 base64
..............

   * Add *note z85encode(): 47b. and *note z85decode(): 47c. functions
     for encoding *note bytes: 192. as Z85 data(1) and decoding
     Z85-encoded data to ‘bytes’.  (Contributed by Matan Perelman in
     gh-75299(2).)

   ---------- Footnotes ----------

   (1) https://rfc.zeromq.org/spec/32/

   (2) https://github.com/python/cpython/issues/75299


File: python.info,  Node: compileall,  Next: concurrent futures<2>,  Prev: base64<2>,  Up: Improved Modules

1.2.5.6 compileall
..................

   * The default number of worker threads and processes is now selected
     using *note os.process_cpu_count(): 4db. instead of *note
     os.cpu_count(): 4dc.  (Contributed by Victor Stinner in
     gh-109649(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109649


File: python.info,  Node: concurrent futures<2>,  Next: configparser<2>,  Prev: compileall,  Up: Improved Modules

1.2.5.7 concurrent.futures
..........................

   * The default number of worker threads and processes is now selected
     using *note os.process_cpu_count(): 4db. instead of *note
     os.cpu_count(): 4dc.  (Contributed by Victor Stinner in
     gh-109649(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109649


File: python.info,  Node: configparser<2>,  Next: copy,  Prev: concurrent futures<2>,  Up: Improved Modules

1.2.5.8 configparser
....................

   * *note ConfigParser: 4df. now has support for unnamed sections,
     which allows for top-level key-value pairs.  This can be enabled
     with the new 'allow_unnamed_section' parameter.  (Contributed by
     Pedro Sousa Lacerda in gh-66449(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/66449


File: python.info,  Node: copy,  Next: ctypes<2>,  Prev: configparser<2>,  Up: Improved Modules

1.2.5.9 copy
............

   * The new *note replace(): 1c0. function and the *note replace
     protocol: 47d. make creating modified copies of objects much
     simpler.  This is especially useful when working with immutable
     objects.  The following types support the *note replace(): 1c0.
     function and implement the replace protocol:

        * *note collections.namedtuple(): 4e1.

        * *note dataclasses.dataclass: 4e2.

        * *note datetime.datetime: 4e3, *note datetime.date: 1fa, *note
          datetime.time: 1fb.

        * *note inspect.Signature: 4e4, *note inspect.Parameter: 4e5.

        * *note types.SimpleNamespace: 4e6.

        * *note code objects: 4e7.

     Any user-defined class can also support *note copy.replace(): 1c0.
     by defining the *note __replace__(): 47d. method.  (Contributed by
     Serhiy Storchaka in gh-108751(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/108751


File: python.info,  Node: ctypes<2>,  Next: dbm,  Prev: copy,  Up: Improved Modules

1.2.5.10 ctypes
...............

   * As a consequence of necessary internal refactoring, initialization
     of internal metaclasses now happens in ‘__init__’ rather than in
     ‘__new__’.  This affects projects that subclass these internal
     metaclasses to provide custom initialization.  Generally:

        - Custom logic that was done in ‘__new__’ after calling
          ‘super().__new__’ should be moved to ‘__init__’.

        - To create a class, call the metaclass, not only the
          metaclass’s ‘__new__’ method.

     See gh-124520(1) for discussion and links to changes in some
     affected projects.

   * *note ctypes.Structure: 1e5. objects have a new *note _align_: 4e9.
     attribute which allows the alignment of the structure being packed
     to/from memory to be specified explicitly.  (Contributed by Matt
     Sanderson in gh-112433(2))

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/124520

   (2) https://github.com/python/cpython/issues/112433


File: python.info,  Node: dbm,  Next: dis<2>,  Prev: ctypes<2>,  Up: Improved Modules

1.2.5.11 dbm
............

   * Add *note dbm.sqlite3: 39, a new module which implements an SQLite
     backend, and make it the default ‘dbm’ backend.  (Contributed by
     Raymond Hettinger and Erlend E. Aasland in gh-100414(1).)

   * Allow removing all items from the database through the new
     ‘clear()’ methods of the GDBM and NDBM database objects.
     (Contributed by Donghee Na in gh-107122(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100414

   (2) https://github.com/python/cpython/issues/107122


File: python.info,  Node: dis<2>,  Next: doctest,  Prev: dbm,  Up: Improved Modules

1.2.5.12 dis
............

   * Change the output of *note dis: 3c. module functions to show
     logical labels for jump targets and exception handlers, rather than
     offsets.  The offsets can be added with the new *note -O: 4ec.
     command-line option or the 'show_offsets' argument.  (Contributed
     by Irit Katriel in gh-112137(1).)

   * *note get_instructions(): 4ed. no longer represents cache entries
     as separate instructions.  Instead, it returns them as part of the
     *note Instruction: 203, in the new 'cache_info' field.  The
     'show_caches' argument to *note get_instructions(): 4ed. is
     deprecated and no longer has any effect.  (Contributed by Irit
     Katriel in gh-112962(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/112137

   (2) https://github.com/python/cpython/issues/112962


File: python.info,  Node: doctest,  Next: email<2>,  Prev: dis<2>,  Up: Improved Modules

1.2.5.13 doctest
................

   * *note doctest: 3e. output is now colored by default.  This can be
     controlled via the new *note PYTHON_COLORS: 476. environment
     variable as well as the canonical NO_COLOR(1) and FORCE_COLOR(2)
     environment variables.  See also *note Controlling color: 1b7.
     (Contributed by Hugo van Kemenade in gh-117225(3).)

   * The *note DocTestRunner.run(): 4ef. method now counts the number of
     skipped tests.  Add the *note DocTestRunner.skips: 4f0. and *note
     TestResults.skipped: 4f1. attributes.  (Contributed by Victor
     Stinner in gh-108794(4).)

   ---------- Footnotes ----------

   (1) https://no-color.org/

   (2) https://force-color.org/

   (3) https://github.com/python/cpython/issues/117225

   (4) https://github.com/python/cpython/issues/108794


File: python.info,  Node: email<2>,  Next: enum,  Prev: doctest,  Up: Improved Modules

1.2.5.14 email
..............

   * Headers with embedded newlines are now quoted on output.  The *note
     generator: 44. will now refuse to serialize (write) headers that
     are improperly folded or delimited, such that they would be parsed
     as multiple headers or joined with adjacent data.  If you need to
     turn this safety feature off, set *note verify_generated_headers:
     4f3.  (Contributed by Bas Bloemsaat and Petr Viktorin in
     gh-121650(1).)

   * *note getaddresses(): 4f4. and *note parseaddr(): 4f5. now return
     ‘('', '')’ pairs in more situations where invalid email addresses
     are encountered instead of potentially inaccurate values.  The two
     functions have a new optional 'strict' parameter (default ‘True’).
     To get the old behavior (accepting malformed input), use
     ‘strict=False’.  ‘getattr(email.utils, 'supports_strict_parsing',
     False)’ can be used to check if the 'strict' parameter is
     available.  (Contributed by Thomas Dwyer and Victor Stinner for
     gh-102988(2) to improve the CVE 2023-27043(3) fix.)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/121650

   (2) https://github.com/python/cpython/issues/102988

   (3) https://www.cve.org/CVERecord?id=CVE-2023-27043


File: python.info,  Node: enum,  Next: fractions<2>,  Prev: email<2>,  Up: Improved Modules

1.2.5.15 enum
.............

   * *note EnumDict: 4f7. has been made public to better support
     subclassing *note EnumType: 4f8.


File: python.info,  Node: fractions<2>,  Next: glob,  Prev: enum,  Up: Improved Modules

1.2.5.16 fractions
..................

   * *note Fraction: 213. objects now support the standard *note format
     specification mini-language: 4fa. rules for fill, alignment, sign
     handling, minimum width, and grouping.  (Contributed by Mark
     Dickinson in gh-111320(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/111320


File: python.info,  Node: glob,  Next: importlib,  Prev: fractions<2>,  Up: Improved Modules

1.2.5.17 glob
.............

   * Add *note translate(): 4fc, a function to convert a path
     specification with shell-style wildcards to a regular expression.
     (Contributed by Barney Gale in gh-72904(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/72904


File: python.info,  Node: importlib,  Next: io<3>,  Prev: glob,  Up: Improved Modules

1.2.5.18 importlib
..................

   * The following functions in *note importlib.resources: 7f. now allow
     accessing a directory (or tree) of resources, using multiple
     positional arguments (the 'encoding' and 'errors' arguments in the
     text-reading functions are now keyword-only):

        * *note is_resource(): 4fe.

        * *note open_binary(): 4ff.

        * *note open_text(): 500.

        * *note path(): 501.

        * *note read_binary(): 502.

        * *note read_text(): 503.

     These functions are no longer deprecated and are not scheduled for
     removal.  (Contributed by Petr Viktorin in gh-116608(1).)

   * *note contents(): 504. remains deprecated in favor of the
     fully-featured *note Traversable: 2fa. API. However, there is now
     no plan to remove it.  (Contributed by Petr Viktorin in
     gh-116608(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116608

   (2) https://github.com/python/cpython/issues/116608


File: python.info,  Node: io<3>,  Next: ipaddress,  Prev: importlib,  Up: Improved Modules

1.2.5.19 io
...........

   * The *note IOBase: 506. finalizer now logs any errors raised by the
     *note close(): 507. method with *note sys.unraisablehook: 508.
     Previously, errors were ignored silently by default, and only
     logged in *note Python Development Mode: 509. or when using a *note
     Python debug build: 50a.  (Contributed by Victor Stinner in
     gh-62948(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/62948


File: python.info,  Node: ipaddress,  Next: itertools<2>,  Prev: io<3>,  Up: Improved Modules

1.2.5.20 ipaddress
..................

   * Add the *note IPv4Address.ipv6_mapped: 50c. property, which returns
     the IPv4-mapped IPv6 address.  (Contributed by Charles Machalow in
     gh-109466(1).)

   * Fix ‘is_global’ and ‘is_private’ behavior in *note IPv4Address:
     50d, *note IPv6Address: 50e, *note IPv4Network: 50f, and *note
     IPv6Network: 510.  (Contributed by Jakub Stasiak in gh-113171(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109466

   (2) https://github.com/python/cpython/issues/113171


File: python.info,  Node: itertools<2>,  Next: marshal,  Prev: ipaddress,  Up: Improved Modules

1.2.5.21 itertools
..................

   * *note batched(): 512. has a new 'strict' parameter, which raises a
     *note ValueError: 2ec. if the final batch is shorter than the
     specified batch size.  (Contributed by Raymond Hettinger in
     gh-113202(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/113202


File: python.info,  Node: marshal,  Next: math<2>,  Prev: itertools<2>,  Up: Improved Modules

1.2.5.22 marshal
................

   * Add the 'allow_code' parameter in module functions.  Passing
     ‘allow_code=False’ prevents serialization and de-serialization of
     code objects which are incompatible between Python versions.
     (Contributed by Serhiy Storchaka in gh-113626(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/113626


File: python.info,  Node: math<2>,  Next: mimetypes<2>,  Prev: marshal,  Up: Improved Modules

1.2.5.23 math
.............

   * The new function *note fma(): 515. performs fused multiply-add
     operations.  This computes ‘x * y + z’ with only a single round,
     and so avoids any intermediate loss of precision.  It wraps the
     ‘fma()’ function provided by C99, and follows the specification of
     the IEEE 754 «fusedMultiplyAdd» operation for special cases.
     (Contributed by Mark Dickinson and Victor Stinner in gh-73468(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/73468


File: python.info,  Node: mimetypes<2>,  Next: mmap,  Prev: math<2>,  Up: Improved Modules

1.2.5.24 mimetypes
..................

   * Add the *note guess_file_type(): 517. function to guess a MIME type
     from a filesystem path.  Using paths with *note guess_type(): 518.
     is now *note soft deprecated: 23d.  (Contributed by Serhiy
     Storchaka in gh-66543(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/66543


File: python.info,  Node: mmap,  Next: multiprocessing<2>,  Prev: mimetypes<2>,  Up: Improved Modules

1.2.5.25 mmap
.............

   * *note mmap: 51a. is now protected from crashing on Windows when the
     mapped memory is inaccessible due to file system errors or access
     violations.  (Contributed by Jannis Weigend in gh-118209(1).)

   * *note mmap: 51a. has a new *note seekable(): 51b. method that can
     be used when a seekable file-like object is required.  The *note
     seek(): 51c. method now returns the new absolute position.
     (Contributed by Donghee Na and Sylvie Liberman in gh-111835(2).)

   * The new UNIX-only 'trackfd' parameter for *note mmap: 51a. controls
     file descriptor duplication; if false, the file descriptor
     specified by 'fileno' will not be duplicated.  (Contributed by
     Zackery Spytz and Petr Viktorin in gh-78502(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118209

   (2) https://github.com/python/cpython/issues/111835

   (3) https://github.com/python/cpython/issues/78502


File: python.info,  Node: multiprocessing<2>,  Next: os<2>,  Prev: mmap,  Up: Improved Modules

1.2.5.26 multiprocessing
........................

   * The default number of worker threads and processes is now selected
     using *note os.process_cpu_count(): 4db. instead of *note
     os.cpu_count(): 4dc.  (Contributed by Victor Stinner in
     gh-109649(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109649


File: python.info,  Node: os<2>,  Next: os path<2>,  Prev: multiprocessing<2>,  Up: Improved Modules

1.2.5.27 os
...........

   * Add *note process_cpu_count(): 4db. function to get the number of
     logical CPU cores usable by the calling thread of the current
     process.  (Contributed by Victor Stinner in gh-109649(1).)

   * *note cpu_count(): 4dc. and *note process_cpu_count(): 4db. can be
     overridden through the new environment variable *note
     PYTHON_CPU_COUNT: 51f. or the new command-line option *note -X
     cpu_count: 16f.  This option is useful for users who need to limit
     CPU resources of a container system without having to modify
     application code or the container itself.  (Contributed by Donghee
     Na in gh-109595(2).)

   * Add a *note low level interface: 47e. to Linux’s ‘timer file
     descriptors(3)’ via *note timerfd_create(): 520, *note
     timerfd_settime(): 521, *note timerfd_settime_ns(): 522, *note
     timerfd_gettime(): 523, *note timerfd_gettime_ns(): 524, *note
     TFD_NONBLOCK: 525, *note TFD_CLOEXEC: 526, *note TFD_TIMER_ABSTIME:
     527, and *note TFD_TIMER_CANCEL_ON_SET: 528. (Contributed by Masaru
     Tsuchiyama in gh-108277(4).)

   * *note lchmod(): 529. and the 'follow_symlinks' argument of *note
     chmod(): 52a. are both now available on Windows.  Note that the
     default value of 'follow_symlinks' in ‘lchmod()’ is ‘False’ on
     Windows.  (Contributed by Serhiy Storchaka in gh-59616(5).)

   * *note fchmod(): 52b. and support for file descriptors in *note
     chmod(): 52a. are both now available on Windows.  (Contributed by
     Serhiy Storchaka in gh-113191(6).)

   * On Windows, *note mkdir(): 52c. and *note makedirs(): 52d. now
     support passing a 'mode' value of ‘0o700’ to apply access control
     to the new directory.  This implicitly affects *note
     tempfile.mkdtemp(): 52e. and is a mitigation for CVE 2024-4030(7).
     Other values for 'mode' continue to be ignored.  (Contributed by
     Steve Dower in gh-118486(8).)

   * *note posix_spawn(): 52f. now accepts ‘None’ for the 'env'
     argument, which makes the newly spawned process use the current
     process environment.  (Contributed by Jakub Kulik in gh-113119(9).)

   * *note posix_spawn(): 52f. can now use the *note
     POSIX_SPAWN_CLOSEFROM: 530. attribute in the 'file_actions'
     parameter on platforms that support
     ‘posix_spawn_file_actions_addclosefrom_np()’.  (Contributed by
     Jakub Kulik in gh-113117(10).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109649

   (2) https://github.com/python/cpython/issues/109595

   (3) https://manpages.debian.org/timerfd_create(2)

   (4) https://github.com/python/cpython/issues/108277

   (5) https://github.com/python/cpython/issues/59616

   (6) https://github.com/python/cpython/issues/113191

   (7) https://www.cve.org/CVERecord?id=CVE-2024-4030

   (8) https://github.com/python/cpython/issues/118486

   (9) https://github.com/python/cpython/issues/113119

   (10) https://github.com/python/cpython/issues/113117


File: python.info,  Node: os path<2>,  Next: pathlib<4>,  Prev: os<2>,  Up: Improved Modules

1.2.5.28 os.path
................

   * Add *note isreserved(): 32b. to check if a path is reserved on the
     current system.  This function is only available on Windows.
     (Contributed by Barney Gale in gh-88569(1).)

   * On Windows, *note isabs(): 532. no longer considers paths starting
     with exactly one slash (‘\’ or ‘/’) to be absolute.  (Contributed
     by Barney Gale and Jon Foster in gh-44626(2).)

   * *note realpath(): 262. now resolves MS-DOS style file names even if
     the file is not accessible.  (Contributed by Moonsik Park in
     gh-82367(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/88569

   (2) https://github.com/python/cpython/issues/44626

   (3) https://github.com/python/cpython/issues/82367


File: python.info,  Node: pathlib<4>,  Next: pdb<3>,  Prev: os path<2>,  Up: Improved Modules

1.2.5.29 pathlib
................

   * Add *note UnsupportedOperation: 534, which is raised instead of
     *note NotImplementedError: 36b. when a path operation isn’t
     supported.  (Contributed by Barney Gale in gh-89812(1).)

   * Add a new constructor for creating *note Path: 266. objects from
     “file” URIs (‘file:///’), *note Path.from_uri(): 535.  (Contributed
     by Barney Gale in gh-107465(2).)

   * Add *note PurePath.full_match(): 536. for matching paths with
     shell-style wildcards, including the recursive wildcard «‘**’».
     (Contributed by Barney Gale in gh-73435(3).)

   * Add the *note PurePath.parser: 537. class attribute to store the
     implementation of *note os.path: a6. used for low-level path
     parsing and joining.  This will be either ‘posixpath’ or ‘ntpath’.

   * Add 'recurse_symlinks' keyword-only argument to *note Path.glob():
     538. and *note rglob(): 539.  (Contributed by Barney Gale in
     gh-77609(4).)

   * *note Path.glob(): 538. and *note rglob(): 539. now return files
     and directories when given a pattern that ends with «‘**’».
     Previously, only directories were returned.  (Contributed by Barney
     Gale in gh-70303(5).)

   * Add the 'follow_symlinks' keyword-only argument to *note
     Path.is_file: 53a, *note Path.is_dir: 53b, *note Path.owner(): 53c,
     and *note Path.group(): 53d.  (Contributed by Barney Gale in
     gh-105793(6) and Kamil Turek in gh-107962(7).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89812

   (2) https://github.com/python/cpython/issues/107465

   (3) https://github.com/python/cpython/issues/73435

   (4) https://github.com/python/cpython/issues/77609

   (5) https://github.com/python/cpython/issues/70303

   (6) https://github.com/python/cpython/issues/105793

   (7) https://github.com/python/cpython/issues/107962


File: python.info,  Node: pdb<3>,  Next: queue,  Prev: pathlib<4>,  Up: Improved Modules

1.2.5.30 pdb
............

   * *note breakpoint(): 271. and *note set_trace(): 272. now enter the
     debugger immediately rather than on the next line of code to be
     executed.  This change prevents the debugger from breaking outside
     of the context when ‘breakpoint()’ is positioned at the end of the
     context.  (Contributed by Tian Gao in gh-118579(1).)

   * ‘sys.path[0]’ is no longer replaced by the directory of the script
     being debugged when *note sys.flags.safe_path: 53f. is set.
     (Contributed by Tian Gao and Christian Walther in gh-111762(2).)

   * *note zipapp: 136. is now supported as a debugging target.
     (Contributed by Tian Gao in gh-118501(3).)

   * Add ability to move between chained exceptions during post-mortem
     debugging in *note pm(): 540. using the new *note exceptions
     [exc_number]: 541. command for Pdb.  (Contributed by Matthias
     Bussonnier in gh-106676(4).)

   * Expressions and statements whose prefix is a pdb command are now
     correctly identified and executed.  (Contributed by Tian Gao in
     gh-108464(5).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118579

   (2) https://github.com/python/cpython/issues/111762

   (3) https://github.com/python/cpython/issues/118501

   (4) https://github.com/python/cpython/issues/106676

   (5) https://github.com/python/cpython/issues/108464


File: python.info,  Node: queue,  Next: random,  Prev: pdb<3>,  Up: Improved Modules

1.2.5.31 queue
..............

   * Add *note Queue.shutdown: 543. and *note ShutDown: 544. to manage
     queue termination.  (Contributed by Laurie Opperman and Yves Duprat
     in gh-104750(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104750


File: python.info,  Node: random,  Next: re<2>,  Prev: queue,  Up: Improved Modules

1.2.5.32 random
...............

   * Add a *note command-line interface: 47f.  (Contributed by Hugo van
     Kemenade in gh-118131(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118131


File: python.info,  Node: re<2>,  Next: shutil,  Prev: random,  Up: Improved Modules

1.2.5.33 re
...........

   * Rename ‘re.error’ to *note PatternError: 547. for improved clarity.
     ‘re.error’ is kept for backward compatibility.


File: python.info,  Node: shutil,  Next: site,  Prev: re<2>,  Up: Improved Modules

1.2.5.34 shutil
...............

   * Support the 'dir_fd' and 'follow_symlinks' keyword arguments in
     *note chown(): 549.  (Contributed by Berker Peksag and Tahia K in
     gh-62308(1))

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/62308


File: python.info,  Node: site,  Next: sqlite3<2>,  Prev: shutil,  Up: Improved Modules

1.2.5.35 site
.............

   * ‘.pth’ files are now decoded using UTF-8 first, and then with the
     *note locale encoding: 54b. if UTF-8 decoding fails.  (Contributed
     by Inada Naoki in gh-117802(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/117802


File: python.info,  Node: sqlite3<2>,  Next: ssl<2>,  Prev: site,  Up: Improved Modules

1.2.5.36 sqlite3
................

   * A *note ResourceWarning: 54d. is now emitted if a *note Connection:
     54e. object is not *note closed: 54f. explicitly.  (Contributed by
     Erlend E. Aasland in gh-105539(1).)

   * Add the 'filter' keyword-only parameter to *note
     Connection.iterdump(): 550. for filtering database objects to dump.
     (Contributed by Mariusz Felisiak in gh-91602(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/105539

   (2) https://github.com/python/cpython/issues/91602


File: python.info,  Node: ssl<2>,  Next: statistics,  Prev: sqlite3<2>,  Up: Improved Modules

1.2.5.37 ssl
............

   * The *note create_default_context(): 480. API now includes *note
     VERIFY_X509_PARTIAL_CHAIN: 481. and *note VERIFY_X509_STRICT: 482.
     in its default flags.

          Nota: *note VERIFY_X509_STRICT: 482. may reject pre- RFC
          5280(1) or malformed certificates that the underlying OpenSSL
          implementation might otherwise accept.  Whilst disabling this
          is not recommended, you can do so using:

               import ssl

               ctx = ssl.create_default_context()
               ctx.verify_flags &= ~ssl.VERIFY_X509_STRICT

     (Contributed by William Woodruff in gh-112389(2).)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc5280.html

   (2) https://github.com/python/cpython/issues/112389


File: python.info,  Node: statistics,  Next: subprocess,  Prev: ssl<2>,  Up: Improved Modules

1.2.5.38 statistics
...................

   * Add *note kde(): 553. for kernel density estimation.  This makes it
     possible to estimate a continuous probability density function from
     a fixed number of discrete samples.  (Contributed by Raymond
     Hettinger in gh-115863(1).)

   * Add *note kde_random(): 554. for sampling from an estimated
     probability density function created by *note kde(): 553.
     (Contributed by Raymond Hettinger in gh-115863(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115863

   (2) https://github.com/python/cpython/issues/115863


File: python.info,  Node: subprocess,  Next: sys<2>,  Prev: statistics,  Up: Improved Modules

1.2.5.39 subprocess
...................

   * The *note subprocess: dc. module now uses the *note posix_spawn():
     52f. function in more situations.

     Notably, when 'close_fds' is ‘True’ (the default), *note
     posix_spawn(): 52f. will be used when the C library provides
     ‘posix_spawn_file_actions_addclosefrom_np()’, which includes recent
     versions of Linux, FreeBSD, and Solaris.  On Linux, this should
     perform similarly to the existing Linux ‘vfork()’ based code.

     A private control knob ‘subprocess._USE_POSIX_SPAWN’ can be set to
     ‘False’ if you need to force *note subprocess: dc. to never use
     *note posix_spawn(): 52f.  Please report your reason and platform
     details in the *note issue tracker: 557. if you set this so that we
     can improve our API selection logic for everyone.  (Contributed by
     Jakub Kulik in gh-113117(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/113117


File: python.info,  Node: sys<2>,  Next: tempfile,  Prev: subprocess,  Up: Improved Modules

1.2.5.40 sys
............

   * Add the *note _is_interned(): 559. function to test if a string was
     interned.  This function is not guaranteed to exist in all
     implementations of Python.  (Contributed by Serhiy Storchaka in
     gh-78573(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/78573


File: python.info,  Node: tempfile,  Next: time,  Prev: sys<2>,  Up: Improved Modules

1.2.5.41 tempfile
.................

   * On Windows, the default mode ‘0o700’ used by *note
     tempfile.mkdtemp(): 52e. now limits access to the new directory due
     to changes to *note os.mkdir(): 52c.  This is a mitigation for CVE
     2024-4030(1).  (Contributed by Steve Dower in gh-118486(2).)

   ---------- Footnotes ----------

   (1) https://www.cve.org/CVERecord?id=CVE-2024-4030

   (2) https://github.com/python/cpython/issues/118486


File: python.info,  Node: time,  Next: tkinter<2>,  Prev: tempfile,  Up: Improved Modules

1.2.5.42 time
.............

   * On Windows, *note monotonic(): 55c. now uses the
     ‘QueryPerformanceCounter()’ clock for a resolution of 1
     microsecond, instead of the ‘GetTickCount64()’ clock which has a
     resolution of 15.6 milliseconds.  (Contributed by Victor Stinner in
     gh-88494(1).)

   * On Windows, *note time(): 55d. now uses the
     ‘GetSystemTimePreciseAsFileTime()’ clock for a resolution of 1
     microsecond, instead of the ‘GetSystemTimeAsFileTime()’ clock which
     has a resolution of 15.6 milliseconds.  (Contributed by Victor
     Stinner in gh-63207(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/88494

   (2) https://github.com/python/cpython/issues/63207


File: python.info,  Node: tkinter<2>,  Next: traceback,  Prev: time,  Up: Improved Modules

1.2.5.43 tkinter
................

   * Add *note tkinter: f6. widget methods: ‘tk_busy_hold()’,
     ‘tk_busy_configure()’, ‘tk_busy_cget()’, ‘tk_busy_forget()’,
     ‘tk_busy_current()’, and ‘tk_busy_status()’.  (Contributed by
     Miguel, klappnase and Serhiy Storchaka in gh-72684(1).)

   * The *note tkinter: f6. widget method ‘wm_attributes()’ now accepts
     the attribute name without the minus prefix to get window
     attributes, for example ‘w.wm_attributes('alpha')’ and allows
     specifying attributes and values to set as keyword arguments, for
     example ‘w.wm_attributes(alpha=0.5)’.  (Contributed by Serhiy
     Storchaka in gh-43457(2).)

   * ‘wm_attributes()’ can now return attributes as a *note dict: 183,
     by using the new optional keyword-only parameter
     'return_python_dict'.  (Contributed by Serhiy Storchaka in
     gh-43457(3).)

   * ‘Text.count()’ can now return a simple *note int: 19b. when the new
     optional keyword-only parameter 'return_ints' is used.  Otherwise,
     the single count is returned as a 1-tuple or ‘None’.  (Contributed
     by Serhiy Storchaka in gh-97928(4).)

   * Support the «vsapi» element type in the *note element_create():
     55f. method of *note tkinter.ttk.Style: 560.  (Contributed by
     Serhiy Storchaka in gh-68166(5).)

   * Add the ‘after_info()’ method for Tkinter widgets.  (Contributed by
     Cheryl Sabella in gh-77020(6).)

   * Add a new ‘copy_replace()’ method to ‘PhotoImage’ to copy a region
     from one image to another, possibly with pixel zooming,
     subsampling, or both.  (Contributed by Serhiy Storchaka in
     gh-118225(7).)

   * Add 'from_coords' parameter to the ‘PhotoImage’ methods ‘copy()’,
     ‘zoom()’ and ‘subsample()’.  Add 'zoom' and 'subsample' parameters
     to the ‘PhotoImage’ method ‘copy()’.  (Contributed by Serhiy
     Storchaka in gh-118225(8).)

   * Add the ‘PhotoImage’ methods ‘read()’ to read an image from a file
     and ‘data()’ to get the image data.  Add 'background' and
     'grayscale' parameters to the ‘write()’ method.  (Contributed by
     Serhiy Storchaka in gh-118271(9).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/72684

   (2) https://github.com/python/cpython/issues/43457

   (3) https://github.com/python/cpython/issues/43457

   (4) https://github.com/python/cpython/issues/97928

   (5) https://github.com/python/cpython/issues/68166

   (6) https://github.com/python/cpython/issues/77020

   (7) https://github.com/python/cpython/issues/118225

   (8) https://github.com/python/cpython/issues/118225

   (9) https://github.com/python/cpython/issues/118271


File: python.info,  Node: traceback,  Next: types<2>,  Prev: tkinter<2>,  Up: Improved Modules

1.2.5.44 traceback
..................

   * Add the *note exc_type_str: 562. attribute to *note
     TracebackException: 563, which holds a string display of the
     'exc_type'.  Deprecate the *note exc_type: 564. attribute, which
     holds the type object itself.  Add parameter 'save_exc_type'
     (default ‘True’) to indicate whether ‘exc_type’ should be saved.
     (Contributed by Irit Katriel in gh-112332(1).)

   * Add a new 'show_group' keyword-only parameter to *note
     TracebackException.format_exception_only(): 565. to (recursively)
     format the nested exceptions of a *note BaseExceptionGroup: 566.
     instance.  (Contributed by Irit Katriel in gh-105292(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/112332

   (2) https://github.com/python/cpython/issues/105292


File: python.info,  Node: types<2>,  Next: typing<2>,  Prev: traceback,  Up: Improved Modules

1.2.5.45 types
..............

   * *note SimpleNamespace: 4e6. can now take a single positional
     argument to initialise the namespace’s arguments.  This argument
     must either be a mapping or an iterable of key-value pairs.
     (Contributed by Serhiy Storchaka in gh-108191(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/108191


File: python.info,  Node: typing<2>,  Next: unicodedata<2>,  Prev: types<2>,  Up: Improved Modules

1.2.5.46 typing
...............

   * PEP 705(1): Add *note ReadOnly: 48b, a special typing construct to
     mark a *note TypedDict: 332. item as read-only for type checkers.

   * PEP 742(2): Add *note TypeIs: 48c, a typing construct that can be
     used to instruct a type checker how to narrow a type.

   * Add *note NoDefault: 569, a sentinel object used to represent the
     defaults of some parameters in the *note typing: 10a. module.
     (Contributed by Jelle Zijlstra in gh-116126(3).)

   * Add *note get_protocol_members(): 56a. to return the set of members
     defining a *note typing.Protocol: 56b.  (Contributed by Jelle
     Zijlstra in gh-104873(4).)

   * Add *note is_protocol(): 56c. to check whether a class is a *note
     Protocol: 56b.  (Contributed by Jelle Zijlstra in gh-104873(5).)

   * *note ClassVar: 56d. can now be nested in *note Final: 56e, and
     vice versa.  (Contributed by Mehdi Drissi in gh-89547(6).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0705/

   (2) https://peps.python.org/pep-0742/

   (3) https://github.com/python/cpython/issues/116126

   (4) https://github.com/python/cpython/issues/104873

   (5) https://github.com/python/cpython/issues/104873

   (6) https://github.com/python/cpython/issues/89547


File: python.info,  Node: unicodedata<2>,  Next: venv,  Prev: typing<2>,  Up: Improved Modules

1.2.5.47 unicodedata
....................

   * Update the Unicode database to version 15.1.0(1).  (Contributed by
     James Gerity in gh-109559(2).)

   ---------- Footnotes ----------

   (1) https://www.unicode.org/versions/Unicode15.1.0/

   (2) https://github.com/python/cpython/issues/109559


File: python.info,  Node: venv,  Next: warnings,  Prev: unicodedata<2>,  Up: Improved Modules

1.2.5.48 venv
.............

   * Add support for creating source control management (SCM) ignore
     files in a virtual environment’s directory.  By default, Git is
     supported.  This is implemented as opt-in via the API, which can be
     extended to support other SCMs (*note EnvBuilder: 571. and *note
     create(): 572.), and opt-out via the CLI, using
     ‘--without-scm-ignore-files’.  (Contributed by Brett Cannon in
     gh-108125(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/108125


File: python.info,  Node: warnings,  Next: xml,  Prev: venv,  Up: Improved Modules

1.2.5.49 warnings
.................

   * PEP 702(1): The new *note warnings.deprecated(): 48a. decorator
     provides a way to communicate deprecations to a *note static type
     checker: 574. and to warn on usage of deprecated classes and
     functions.  A *note DeprecationWarning: 1a3. may also be emitted
     when a decorated function or class is used at runtime.
     (Contributed by Jelle Zijlstra in gh-104003(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0702/

   (2) https://github.com/python/cpython/issues/104003


File: python.info,  Node: xml,  Next: zipimport,  Prev: warnings,  Up: Improved Modules

1.2.5.50 xml
............

   * Allow controlling Expat >=2.6.0 reparse deferral ( CVE
     2023-52425(1)) by adding five new methods:

        * *note xml.etree.ElementTree.XMLParser.flush(): 576.

        * *note xml.etree.ElementTree.XMLPullParser.flush(): 577.

        * *note xml.parsers.expat.xmlparser.GetReparseDeferralEnabled():
          578.

        * *note xml.parsers.expat.xmlparser.SetReparseDeferralEnabled():
          579.

        * ‘xml.sax.expatreader.ExpatParser.flush()’

     (Contributed by Sebastian Pipping in gh-115623(2).)

   * Add the ‘close()’ method for the iterator returned by *note
     iterparse(): 57a. for explicit cleanup.  (Contributed by Serhiy
     Storchaka in gh-69893(3).)

   ---------- Footnotes ----------

   (1) https://www.cve.org/CVERecord?id=CVE-2023-52425

   (2) https://github.com/python/cpython/issues/115623

   (3) https://github.com/python/cpython/issues/69893


File: python.info,  Node: zipimport,  Prev: xml,  Up: Improved Modules

1.2.5.51 zipimport
..................

   * Add support for ZIP64(1) format files.  Everybody loves huge data,
     right?  (Contributed by Tim Hatch in gh-94146(2).)

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Zip_(file_format)#ZIP64

   (2) https://github.com/python/cpython/issues/94146


File: python.info,  Node: Optimizations<2>,  Next: Removed Modules And APIs,  Prev: Improved Modules,  Up: What’s New In Python 3 13

1.2.6 Optimizations
-------------------

   * Several standard library modules have had their import times
     significantly improved.  For example, the import time of the *note
     typing: 10a. module has been reduced by around a third by removing
     dependencies on *note re: be. and *note contextlib: 27.  Other
     modules to enjoy import-time speedups include *note email.utils:
     54, *note enum: 5a, *note functools: 63, *note importlib.metadata:
     7e, and *note threading: f3.  (Contributed by Alex Waygood,
     Shantanu Jain, Adam Turner, Daniel Hollas, and others in
     gh-109653(1).)

   * *note textwrap.indent(): 57d. is now around 30% faster than before
     for large input.  (Contributed by Inada Naoki in gh-107369(2).)

   * The *note subprocess: dc. module now uses the *note posix_spawn():
     52f. function in more situations, including when 'close_fds' is
     ‘True’ (the default) on many modern platforms.  This should provide
     a notable performance increase when launching processes on FreeBSD
     and Solaris.  See the *note subprocess: 556. section above for
     details.  (Contributed by Jakub Kulik in gh-113117(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109653

   (2) https://github.com/python/cpython/issues/107369

   (3) https://github.com/python/cpython/issues/113117


File: python.info,  Node: Removed Modules And APIs,  Next: New Deprecations,  Prev: Optimizations<2>,  Up: What’s New In Python 3 13

1.2.7 Removed Modules And APIs
------------------------------

* Menu:

* PEP 594; Remove «dead batteries» from the standard library: PEP 594 Remove «dead batteries» from the standard library.
* 2to3::
* builtins::
* configparser: configparser<3>.
* importlib.metadata: importlib metadata.
* locale::
* opcode::
* optparse::
* pathlib: pathlib<5>.
* re: re<3>.
* tkinter.tix: tkinter tix.
* turtle: turtle<2>.
* typing: typing<3>.
* unittest: unittest<2>.
* urllib: urllib<3>.
* webbrowser: webbrowser<2>.


File: python.info,  Node: PEP 594 Remove «dead batteries» from the standard library,  Next: 2to3,  Up: Removed Modules And APIs

1.2.7.1 PEP 594: Remove «dead batteries» from the standard library
..................................................................

PEP 594(1) proposed removing 19 modules from the standard library,
colloquially referred to as “dead batteries” due to their historic,
obsolete, or insecure status.  All of the following modules were
deprecated in Python 3.11, and are now removed:

   * ‘aifc’

        * standard-aifc(2): Use the redistribution of ‘aifc’ library
          from PyPI.

   * ‘audioop’

        * audioop-lts(3): Use ‘audioop-lts’ library from PyPI.

   * ‘chunk’

        * standard-chunk(4): Use the redistribution of ‘chunk’ library
          from PyPI.

   * ‘cgi’ and ‘cgitb’

        * ‘cgi.FieldStorage’ can typically be replaced with *note
          urllib.parse.parse_qsl(): 31e. for ‘GET’ and ‘HEAD’ requests,
          and the *note email.message: 48. module or the multipart(5)
          library for ‘POST’ and ‘PUT’ requests.

        * ‘cgi.parse()’ can be replaced by calling *note
          urllib.parse.parse_qs(): 31f. directly on the desired query
          string, unless the input is ‘multipart/form-data’, which
          should be replaced as described below for
          ‘cgi.parse_multipart()’.

        * ‘cgi.parse_header()’ can be replaced with the functionality in
          the *note email: 3f. package, which implements the same MIME
          RFCs.  For example, with *note email.message.EmailMessage:
          580.:

               from email.message import EmailMessage

               msg = EmailMessage()
               msg['content-type'] = 'application/json; charset="utf8"'
               main, params = msg.get_content_type(), msg['content-type'].params

        * ‘cgi.parse_multipart()’ can be replaced with the functionality
          in the *note email: 3f. package, which implements the same
          MIME RFCs, or with the multipart(6) library.  For example, the
          *note email.message.EmailMessage: 580. and *note
          email.message.Message: 581. classes.

        * standard-cgi(7): and standard-cgitb(8): Use the redistribution
          of ‘cgi’ and ‘cgitb’ library from PyPI.

   * ‘crypt’ and the private ‘_crypt’ extension.  The *note hashlib: 6c.
     module may be an appropriate replacement when simply hashing a
     value is required.  Otherwise, various third-party libraries on
     PyPI are available:

        * bcrypt(9): Modern password hashing for your software and your
          servers.

        * argon2-cffi(10): The secure Argon2 password hashing algorithm.

        * legacycrypt(11): *note ctypes: 2e. wrapper to the POSIX crypt
          library call and associated functionality.

        * crypt_r(12): Fork of the ‘crypt’ module, wrapper to the
          ‘crypt_r(3)(13)’ library call and associated functionality.

        * standard-crypt(14) and deprecated-crypt-alternative(15): Use
          the redistribution of ‘crypt’ and reimplementation of ‘_crypt’
          libraries from PyPI.

   * ‘imghdr’: The filetype(16), puremagic(17), or python-magic(18)
     libraries should be used as replacements.  For example, the
     ‘puremagic.what()’ function can be used to replace the
     ‘imghdr.what()’ function for all file formats that were supported
     by ‘imghdr’.

        * standard-imghdr(19): Use the redistribution of ‘imghdr’
          library from PyPI.

   * ‘mailcap’: Use the *note mimetypes: 93. module instead.

        * standard-mailcap(20): Use the redistribution of ‘mailcap’
          library from PyPI.

   * ‘msilib’

   * ‘nis’

   * ‘nntplib’: Use the pynntp(21) library from PyPI instead.

        * standard-nntplib(22): Use the redistribution of ‘nntplib’
          library from PyPI.

   * ‘ossaudiodev’: For audio playback, use the pygame(23) library from
     PyPI instead.

   * ‘pipes’: Use the *note subprocess: dc. module instead.  Use *note
     shlex.quote(): 582. to replace the undocumented ‘pipes.quote’
     function.

        * standard-pipes(24): Use the redistribution of ‘pipes’ library
          from PyPI.

   * ‘sndhdr’: The filetype(25), puremagic(26), or python-magic(27)
     libraries should be used as replacements.

        * standard-sndhdr(28): Use the redistribution of ‘sndhdr’
          library from PyPI.

   * ‘spwd’: Use the python-pam(29) library from PyPI instead.

   * ‘sunau’

        * standard-sunau(30): Use the redistribution of ‘sunau’ library
          from PyPI.

   * ‘telnetlib’, Use the telnetlib3(31) or Exscript(32) libraries from
     PyPI instead.

        * standard-telnetlib(33): Use the redistribution of ‘telnetlib’
          library from PyPI.

   * ‘uu’: Use the *note base64: f. module instead, as a modern
     alternative.

        * standard-uu(34): Use the redistribution of ‘uu’ library from
          PyPI.

   * ‘xdrlib’

        * standard-xdrlib(35): Use the redistribution of ‘xdrlib’
          library from PyPI.

(Contributed by Victor Stinner and Zachary Ware in gh-104773(36) and
gh-104780(37).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://pypi.org/project/standard-aifc/

   (3) https://pypi.org/project/audioop-lts/

   (4) https://pypi.org/project/standard-chunk/

   (5) https://pypi.org/project/multipart/

   (6) https://pypi.org/project/multipart/

   (7) https://pypi.org/project/standard-cgi/

   (8) https://pypi.org/project/standard-cgitb/

   (9) https://pypi.org/project/bcrypt/

   (10) https://pypi.org/project/argon2-cffi/

   (11) https://pypi.org/project/legacycrypt/

   (12) https://pypi.org/project/crypt_r/

   (13) https://manpages.debian.org/crypt_r(3)

   (14) https://pypi.org/project/standard-crypt/

   (15) https://pypi.org/project/deprecated-crypt-alternative/

   (16) https://pypi.org/project/filetype/

   (17) https://pypi.org/project/puremagic/

   (18) https://pypi.org/project/python-magic/

   (19) https://pypi.org/project/standard-imghdr/

   (20) https://pypi.org/project/standard-mailcap/

   (21) https://pypi.org/project/pynntp/

   (22) https://pypi.org/project/standard-nntplib/

   (23) https://pypi.org/project/pygame/

   (24) https://pypi.org/project/standard-pipes/

   (25) https://pypi.org/project/filetype/

   (26) https://pypi.org/project/puremagic/

   (27) https://pypi.org/project/python-magic/

   (28) https://pypi.org/project/standard-sndhdr/

   (29) https://pypi.org/project/python-pam/

   (30) https://pypi.org/project/standard-sunau/

   (31) https://pypi.org/project/telnetlib3/

   (32) https://pypi.org/project/Exscript/

   (33) https://pypi.org/project/standard-telnetlib/

   (34) https://pypi.org/project/standard-uu/

   (35) https://pypi.org/project/standard-xdrlib/

   (36) https://github.com/python/cpython/issues/104773

   (37) https://github.com/python/cpython/issues/104780


File: python.info,  Node: 2to3,  Next: builtins,  Prev: PEP 594 Remove «dead batteries» from the standard library,  Up: Removed Modules And APIs

1.2.7.2 2to3
............

   * Remove the ‘2to3’ program and the ‘lib2to3’ module, previously
     deprecated in Python 3.11.  (Contributed by Victor Stinner in
     gh-104780(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104780


File: python.info,  Node: builtins,  Next: configparser<3>,  Prev: 2to3,  Up: Removed Modules And APIs

1.2.7.3 builtins
................

   * Remove support for chained *note classmethod: 48f. descriptors
     (introduced in gh-63272(1)).  These can no longer be used to wrap
     other descriptors, such as *note property: 4b4.  The core design of
     this feature was flawed and led to several problems.  To
     «pass-through» a *note classmethod: 48f, consider using the
     ‘__wrapped__’ attribute that was added in Python 3.10.
     (Contributed by Raymond Hettinger in gh-89519(2).)

   * Raise a *note RuntimeError: 244. when calling *note frame.clear():
     585. on a suspended frame (as has always been the case for an
     executing frame).  (Contributed by Irit Katriel in gh-79932(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/63272

   (2) https://github.com/python/cpython/issues/89519

   (3) https://github.com/python/cpython/issues/79932


File: python.info,  Node: configparser<3>,  Next: importlib metadata,  Prev: builtins,  Up: Removed Modules And APIs

1.2.7.4 configparser
....................

   * Remove the undocumented ‘LegacyInterpolation’ class, deprecated in
     the docstring since Python 3.2, and at runtime since Python 3.11.
     (Contributed by Hugo van Kemenade in gh-104886(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104886


File: python.info,  Node: importlib metadata,  Next: locale,  Prev: configparser<3>,  Up: Removed Modules And APIs

1.2.7.5 importlib.metadata
..........................

   * Remove deprecated subscript (*note __getitem__(): 588.) access for
     *note EntryPoint: 589. objects.  (Contributed by Jason R. Coombs in
     gh-113175(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/113175


File: python.info,  Node: locale,  Next: opcode,  Prev: importlib metadata,  Up: Removed Modules And APIs

1.2.7.6 locale
..............

   * Remove the ‘locale.resetlocale()’ function, deprecated in Python
     3.11.  Use ‘locale.setlocale(locale.LC_ALL, "")’ instead.
     (Contributed by Victor Stinner in gh-104783(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104783


File: python.info,  Node: opcode,  Next: optparse,  Prev: locale,  Up: Removed Modules And APIs

1.2.7.7 opcode
..............

   * Move ‘opcode.ENABLE_SPECIALIZATION’ to
     ‘_opcode.ENABLE_SPECIALIZATION’.  This field was added in 3.12, it
     was never documented, and is not intended for external use.
     (Contributed by Irit Katriel in gh-105481(1).)

   * Remove ‘opcode.is_pseudo()’, ‘opcode.MIN_PSEUDO_OPCODE’, and
     ‘opcode.MAX_PSEUDO_OPCODE’, which were added in Python 3.12, but
     were neither documented nor exposed through *note dis: 3c, and were
     not intended to be used externally.  (Contributed by Irit Katriel
     in gh-105481(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/105481

   (2) https://github.com/python/cpython/issues/105481


File: python.info,  Node: optparse,  Next: pathlib<5>,  Prev: opcode,  Up: Removed Modules And APIs

1.2.7.8 optparse
................

   * This module is no longer considered *note soft deprecated: 23d.
     While *note argparse: 7. remains preferred for new projects that
     aren’t using a third party command line argument processing
     library, there are aspects of the way ‘argparse’ works that mean
     the lower level ‘optparse’ module may provide a better foundation
     for 'writing' argument processing libraries, and for implementing
     command line applications which adhere more strictly than
     ‘argparse’ does to various Unix command line processing conventions
     that originate in the behaviour of the C ‘getopt()’ function .
     (Contributed by Alyssa Coghlan and Serhiy Storchaka in
     gh-126180(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126180


File: python.info,  Node: pathlib<5>,  Next: re<3>,  Prev: optparse,  Up: Removed Modules And APIs

1.2.7.9 pathlib
...............

   * Remove the ability to use *note Path: 266. objects as context
     managers.  This functionality was deprecated and has had no effect
     since Python 3.9.  (Contributed by Barney Gale in gh-83863(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/83863


File: python.info,  Node: re<3>,  Next: tkinter tix,  Prev: pathlib<5>,  Up: Removed Modules And APIs

1.2.7.10 re
...........

   * Remove the undocumented, deprecated, and broken ‘re.template()’
     function and ‘re.TEMPLATE’ / ‘re.T’ flag.  (Contributed by Serhiy
     Storchaka and Nikita Sobolev in gh-105687(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/105687


File: python.info,  Node: tkinter tix,  Next: turtle<2>,  Prev: re<3>,  Up: Removed Modules And APIs

1.2.7.11 tkinter.tix
....................

   * Remove the ‘tkinter.tix’ module, deprecated in Python 3.6.  The
     third-party Tix library which the module wrapped is unmaintained.
     (Contributed by Zachary Ware in gh-75552(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/75552


File: python.info,  Node: turtle<2>,  Next: typing<3>,  Prev: tkinter tix,  Up: Removed Modules And APIs

1.2.7.12 turtle
...............

   * Remove the ‘RawTurtle.settiltangle()’ method, deprecated in the
     documentation since Python 3.1 and at runtime since Python 3.11.
     (Contributed by Hugo van Kemenade in gh-104876(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104876


File: python.info,  Node: typing<3>,  Next: unittest<2>,  Prev: turtle<2>,  Up: Removed Modules And APIs

1.2.7.13 typing
...............

   * Remove the ‘typing.io’ and ‘typing.re’ namespaces, deprecated since
     Python 3.8.  The items in those namespaces can be imported directly
     from the *note typing: 10a. module.  (Contributed by Sebastian
     Rittau in gh-92871(1).)

   * Remove the keyword-argument method of creating *note TypedDict:
     332. types, deprecated in Python 3.11.  (Contributed by Tomas Roun
     in gh-104786(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/92871

   (2) https://github.com/python/cpython/issues/104786


File: python.info,  Node: unittest<2>,  Next: urllib<3>,  Prev: typing<3>,  Up: Removed Modules And APIs

1.2.7.14 unittest
.................

   * Remove the following *note unittest: 10c. functions, deprecated in
     Python 3.11:

        * ‘unittest.findTestCases()’

        * ‘unittest.makeSuite()’

        * ‘unittest.getTestCaseNames()’

     Use *note TestLoader: 593. methods instead:

        * *note loadTestsFromModule(): 594.

        * *note loadTestsFromTestCase(): 595.

        * *note getTestCaseNames(): 596.

     (Contributed by Hugo van Kemenade in gh-104835(1).)

   * Remove the untested and undocumented ‘TestProgram.usageExit()’
     method, deprecated in Python 3.11.  (Contributed by Hugo van
     Kemenade in gh-104992(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104835

   (2) https://github.com/python/cpython/issues/104992


File: python.info,  Node: urllib<3>,  Next: webbrowser<2>,  Prev: unittest<2>,  Up: Removed Modules And APIs

1.2.7.15 urllib
...............

   * Remove the 'cafile', 'capath', and 'cadefault' parameters of the
     *note urllib.request.urlopen(): 307. function, deprecated in Python
     3.6.  Use the 'context' parameter instead with an *note SSLContext:
     357. instance.  The *note ssl.SSLContext.load_cert_chain(): 598.
     function can be used to load specific certificates, or let *note
     ssl.create_default_context(): 480. select the operating system’s
     trusted certificate authority (CA) certificates.  (Contributed by
     Victor Stinner in gh-105382(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/105382


File: python.info,  Node: webbrowser<2>,  Prev: urllib<3>,  Up: Removed Modules And APIs

1.2.7.16 webbrowser
...................

   * Remove the untested and undocumented ‘MacOSX’ class, deprecated in
     Python 3.11.  Use the ‘MacOSXOSAScript’ class (introduced in Python
     3.2) instead.  (Contributed by Hugo van Kemenade in gh-104804(1).)

   * Remove the deprecated ‘MacOSXOSAScript._name’ attribute.  Use the
     *note MacOSXOSAScript.name: 59a. attribute instead.  (Contributed
     by Nikita Sobolev in gh-105546(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104804

   (2) https://github.com/python/cpython/issues/105546


File: python.info,  Node: New Deprecations,  Next: CPython Bytecode Changes,  Prev: Removed Modules And APIs,  Up: What’s New In Python 3 13

1.2.8 New Deprecations
----------------------

   * *note User-defined functions: 59c.:

        * Deprecate assignment to a function’s *note __code__: 59d.
          attribute, where the new code object’s type does not match the
          function’s type.  The different types are: plain function,
          generator, async generator, and coroutine.  (Contributed by
          Irit Katriel in gh-81137(1).)

   * *note array: 8.:

        * Deprecate the ‘'u'’ format code (‘wchar_t’) at runtime.  This
          format code has been deprecated in documentation since Python
          3.3, and will be removed in Python 3.16.  Use the ‘'w'’ format
          code (*note Py_UCS4: 33d.) for Unicode characters instead.
          (Contributed by Hugo van Kemenade in gh-80480(2).)

   * *note ctypes: 2e.:

        * Deprecate the undocumented ‘SetPointerType()’ function, to be
          removed in Python 3.15.  (Contributed by Victor Stinner in
          gh-105733(3).)

        * *note Soft-deprecate: 23d. the *note ARRAY(): 59e. function in
          favour of ‘type * length’ multiplication.  (Contributed by
          Victor Stinner in gh-105733(4).)

   * *note decimal: 3a.:

        * Deprecate the non-standard and undocumented *note Decimal:
          1fe. format specifier ‘'N'’, which is only supported in the
          ‘decimal’ module’s C implementation.  Scheduled to be removed
          in Python 3.18.  (Contributed by Serhiy Storchaka in
          gh-89902(5).)

   * *note dis: 3c.:

        * Deprecate the ‘HAVE_ARGUMENT’ separator.  Check membership in
          *note hasarg: 59f. instead.  (Contributed by Irit Katriel in
          gh-109319(6).)

   * *note gettext: 67.:

        * Deprecate non-integer numbers as arguments to functions and
          methods that consider plural forms in the ‘gettext’ module,
          even if no translation was found.  (Contributed by Serhiy
          Storchaka in gh-88434(7).)

   * *note glob: 68.:

        * Deprecate the undocumented ‘glob0()’ and ‘glob1()’ functions.
          Use *note glob(): 5a0. and pass a *note path-like object: 5a1.
          specifying the root directory to the 'root_dir' parameter
          instead.  (Contributed by Barney Gale in gh-117337(8).)

   * *note http.server: 76.:

        * Deprecate *note CGIHTTPRequestHandler: 325, to be removed in
          Python 3.15.  Process-based CGI HTTP servers have been out of
          favor for a very long time.  This code was outdated,
          unmaintained, and rarely used.  It has a high potential for
          both security and functionality bugs.  (Contributed by Gregory
          P. Smith in gh-109096(9).)

        * Deprecate the ‘--cgi’ flag to the ‘python -m http.server’
          command-line interface, to be removed in Python 3.15.
          (Contributed by Gregory P. Smith in gh-109096(10).)

   * *note mimetypes: 93.:

        * *note Soft-deprecate: 23d. file path arguments to *note
          guess_type(): 518, use *note guess_file_type(): 517. instead.
          (Contributed by Serhiy Storchaka in gh-66543(11).)

   * *note re: be.:

        * Deprecate passing the optional 'maxsplit', 'count', or 'flags'
          arguments as positional arguments to the module-level *note
          split(): 5a2, *note sub(): 5a3, and *note subn(): 5a4.
          functions.  These parameters will become *note keyword-only:
          5a5. in a future version of Python.  (Contributed by Serhiy
          Storchaka in gh-56166(12).)

   * *note pathlib: a8.:

        * Deprecate *note PurePath.is_reserved(): 32a, to be removed in
          Python 3.15.  Use *note os.path.isreserved(): 32b. to detect
          reserved paths on Windows.  (Contributed by Barney Gale in
          gh-88569(13).)

   * *note platform: af.:

        * Deprecate *note java_ver(): 32c, to be removed in Python 3.15.
          This function is only useful for Jython support, has a
          confusing API, and is largely untested.  (Contributed by
          Nikita Sobolev in gh-116349(14).)

   * *note pydoc: ba.:

        * Deprecate the undocumented ‘ispackage()’ function.
          (Contributed by Zackery Spytz in gh-64020(15).)

   * *note sqlite3: d4.:

        * Deprecate passing more than one positional argument to the
          *note connect(): 5a6. function and the *note Connection: 54e.
          constructor.  The remaining parameters will become
          keyword-only in Python 3.15.  (Contributed by Erlend E.
          Aasland in gh-107948(16).)

        * Deprecate passing name, number of arguments, and the callable
          as keyword arguments for *note Connection.create_function():
          5a7. and *note Connection.create_aggregate(): 5a8. These
          parameters will become positional-only in Python 3.15.
          (Contributed by Erlend E. Aasland in gh-108278(17).)

        * Deprecate passing the callback callable by keyword for the
          *note set_authorizer(): 5a9, *note set_progress_handler():
          5aa, and *note set_trace_callback(): 5ab. *note Connection:
          54e. methods.  The callback callables will become
          positional-only in Python 3.15.  (Contributed by Erlend E.
          Aasland in gh-108278(18).)

   * *note sys: df.:

        * Deprecate the *note _enablelegacywindowsfsencoding(): 33e.
          function, to be removed in Python 3.16.  Use the *note
          PYTHONLEGACYWINDOWSFSENCODING: 33f. environment variable
          instead.  (Contributed by Inada Naoki in gh-73427(19).)

   * *note tarfile: e4.:

        * Deprecate the undocumented and unused ‘TarFile.tarfile’
          attribute, to be removed in Python 3.16.  (Contributed in
          gh-115256(20).)

   * *note traceback: 104.:

        * Deprecate the *note TracebackException.exc_type: 564.
          attribute.  Use *note TracebackException.exc_type_str: 562.
          instead.  (Contributed by Irit Katriel in gh-112332(21).)

   * *note typing: 10a.:

        * Deprecate the undocumented keyword argument syntax for
          creating *note NamedTuple: 331. classes (e.g.  ‘Point =
          NamedTuple("Point", x=int, y=int)’), to be removed in Python
          3.15.  Use the class-based syntax or the functional syntax
          instead.  (Contributed by Alex Waygood in gh-105566(22).)

        * Deprecate omitting the 'fields' parameter when creating a
          *note NamedTuple: 331. or *note typing.TypedDict: 332. class,
          and deprecate passing ‘None’ to the 'fields' parameter of both
          types.  Python 3.15 will require a valid sequence for the
          'fields' parameter.  To create a NamedTuple class with zero
          fields, use ‘class NT(NamedTuple): pass’ or ‘NT =
          NamedTuple("NT", ())’.  To create a TypedDict class with zero
          fields, use ‘class TD(TypedDict): pass’ or ‘TD =
          TypedDict("TD", {})’.  (Contributed by Alex Waygood in
          gh-105566(23) and gh-105570(24).)

        * Deprecate the *note typing.no_type_check_decorator(): 333.
          decorator function, to be removed in Python 3.15.  After eight
          years in the *note typing: 10a. module, it has yet to be
          supported by any major type checker.  (Contributed by Alex
          Waygood in gh-106309(25).)

        * Deprecate *note typing.AnyStr: 5ac.  In Python 3.16, it will
          be removed from ‘typing.__all__’, and a *note
          DeprecationWarning: 1a3. will be emitted at runtime when it is
          imported or accessed.  It will be removed entirely in Python
          3.18.  Use the new *note type parameter syntax: 5ad. instead.
          (Contributed by Michael The in gh-107116(26).)

   * *note wave: 119.:

        * Deprecate the *note getmark(): 334, ‘setmark()’, and *note
          getmarkers(): 335. methods of the *note Wave_read: 336. and
          *note Wave_write: 337. classes, to be removed in Python 3.15.
          (Contributed by Victor Stinner in gh-105096(27).)

* Menu:

* Pending removal in Python 3.14: Pending removal in Python 3 14.
* Pending removal in Python 3.15: Pending removal in Python 3 15<3>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<3>.
* Pending removal in Python 3.17: Pending removal in Python 3 17<2>.
* Pending removal in Python 3.18: Pending removal in Python 3 18<3>.
* Pending removal in Python 3.19: Pending removal in Python 3 19<2>.
* Pending removal in future versions: Pending removal in future versions<3>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/81137

   (2) https://github.com/python/cpython/issues/80480

   (3) https://github.com/python/cpython/issues/105733

   (4) https://github.com/python/cpython/issues/105733

   (5) https://github.com/python/cpython/issues/89902

   (6) https://github.com/python/cpython/issues/109319

   (7) https://github.com/python/cpython/issues/88434

   (8) https://github.com/python/cpython/issues/117337

   (9) https://github.com/python/cpython/issues/109096

   (10) https://github.com/python/cpython/issues/109096

   (11) https://github.com/python/cpython/issues/66543

   (12) https://github.com/python/cpython/issues/56166

   (13) https://github.com/python/cpython/issues/88569

   (14) https://github.com/python/cpython/issues/116349

   (15) https://github.com/python/cpython/issues/64020

   (16) https://github.com/python/cpython/issues/107948

   (17) https://github.com/python/cpython/issues/108278

   (18) https://github.com/python/cpython/issues/108278

   (19) https://github.com/python/cpython/issues/73427

   (20) https://github.com/python/cpython/issues/115256

   (21) https://github.com/python/cpython/issues/112332

   (22) https://github.com/python/cpython/issues/105566

   (23) https://github.com/python/cpython/issues/105566

   (24) https://github.com/python/cpython/issues/105570

   (25) https://github.com/python/cpython/issues/106309

   (26) https://github.com/python/cpython/issues/107116

   (27) https://github.com/python/cpython/issues/105096


File: python.info,  Node: Pending removal in Python 3 14,  Next: Pending removal in Python 3 15<3>,  Up: New Deprecations

1.2.8.1 Pending removal in Python 3.14
......................................

   * *note argparse: 7.: The 'type', 'choices', and 'metavar' parameters
     of ‘argparse.BooleanOptionalAction’ are deprecated and will be
     removed in 3.14.  (Contributed by Nikita Sobolev in gh-92248(1).)

   * *note ast: 9.: The following features have been deprecated in
     documentation since Python 3.8, now cause a *note
     DeprecationWarning: 1a3. to be emitted at runtime when they are
     accessed or used, and will be removed in Python 3.14:

        * ‘ast.Num’

        * ‘ast.Str’

        * ‘ast.Bytes’

        * ‘ast.NameConstant’

        * ‘ast.Ellipsis’

     Use *note ast.Constant: 2ef. instead.  (Contributed by Serhiy
     Storchaka in gh-90953(2).)

   * *note asyncio: b.:

        * The child watcher classes ‘asyncio.MultiLoopChildWatcher’,
          ‘asyncio.FastChildWatcher’, ‘asyncio.AbstractChildWatcher’ and
          ‘asyncio.SafeChildWatcher’ are deprecated and will be removed
          in Python 3.14.  (Contributed by Kumar Aditya in gh-94597(3).)

        * ‘asyncio.set_child_watcher()’, ‘asyncio.get_child_watcher()’,
          ‘asyncio.AbstractEventLoopPolicy.set_child_watcher()’ and
          ‘asyncio.AbstractEventLoopPolicy.get_child_watcher()’ are
          deprecated and will be removed in Python 3.14.  (Contributed
          by Kumar Aditya in gh-94597(4).)

        * The *note get_event_loop(): 2f2. method of the default event
          loop policy now emits a *note DeprecationWarning: 1a3. if
          there is no current event loop set and it decides to create
          one.  (Contributed by Serhiy Storchaka and Guido van Rossum in
          gh-100160(5).)

   * *note email: 3f.: Deprecated the 'isdst' parameter in *note
     email.utils.localtime(): 2f7.  (Contributed by Alan Williams in
     gh-72346(6).)

   * *note importlib.abc: 7c. deprecated classes:

        * ‘importlib.abc.ResourceReader’

        * ‘importlib.abc.Traversable’

        * ‘importlib.abc.TraversableResources’

     Use *note importlib.resources.abc: 80. classes instead:

        * *note importlib.resources.abc.Traversable: 2fa.

        * *note importlib.resources.abc.TraversableResources: 2f9.

     (Contributed by Jason R. Coombs and Hugo van Kemenade in
     gh-93963(7).)

   * *note itertools: 85. had undocumented, inefficient, historically
     buggy, and inconsistent support for copy, deepcopy, and pickle
     operations.  This will be removed in 3.14 for a significant
     reduction in code volume and maintenance burden.  (Contributed by
     Raymond Hettinger in gh-101588(8).)

   * *note multiprocessing: 98.: The default start method will change to
     a safer one on Linux, BSDs, and other non-macOS POSIX platforms
     where ‘'fork'’ is currently the default (gh-84559(9)).  Adding a
     runtime warning about this was deemed too disruptive as the
     majority of code is not expected to care.  Use the *note
     get_context(): 24a. or *note set_start_method(): 24b. APIs to
     explicitly specify when your code 'requires' ‘'fork'’.  See *note
     Contexts and start methods: 1d5.

   * *note pathlib: a8.: *note is_relative_to(): 2fe. and *note
     relative_to(): 2fd.: passing additional arguments is deprecated.

   * *note pkgutil: ae.: ‘pkgutil.find_loader()’ and
     ‘pkgutil.get_loader()’ now raise *note DeprecationWarning: 1a3.;
     use *note importlib.util.find_spec(): 5af. instead.  (Contributed
     by Nikita Sobolev in gh-97850(10).)

   * *note pty: b6.:

        * ‘master_open()’: use *note pty.openpty(): 301.

        * ‘slave_open()’: use *note pty.openpty(): 301.

   * *note sqlite3: d4.:

        * ‘version’ and ‘version_info’.

        * *note execute(): 5b0. and *note executemany(): 5b1. if *note
          named placeholders: 5b2. are used and 'parameters' is a
          sequence instead of a *note dict: 183.

   * *note urllib: 10e.: ‘urllib.parse.Quoter’ is deprecated: it was not
     intended to be a public API. (Contributed by Gregory P. Smith in
     gh-88168(11).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/92248

   (2) https://github.com/python/cpython/issues/90953

   (3) https://github.com/python/cpython/issues/94597

   (4) https://github.com/python/cpython/issues/94597

   (5) https://github.com/python/cpython/issues/100160

   (6) https://github.com/python/cpython/issues/72346

   (7) https://github.com/python/cpython/issues/93963

   (8) https://github.com/python/cpython/issues/101588

   (9) https://github.com/python/cpython/issues/84559

   (10) https://github.com/python/cpython/issues/97850

   (11) https://github.com/python/cpython/issues/88168


File: python.info,  Node: Pending removal in Python 3 15<3>,  Next: Pending removal in Python 3 16<3>,  Prev: Pending removal in Python 3 14,  Up: New Deprecations

1.2.8.2 Pending removal in Python 3.15
......................................

   * The import system:

        * Setting *note __cached__: 321. on a module while failing to
          set *note __spec__.cached: 322. is deprecated.  In Python
          3.15, ‘__cached__’ will cease to be set or take into
          consideration by the import system or standard library.
          (gh-97879(1))

        * Setting *note __package__: 323. on a module while failing to
          set *note __spec__.parent: 324. is deprecated.  In Python
          3.15, ‘__package__’ will cease to be set or take into
          consideration by the import system or standard library.
          (gh-97879(2))

   * *note ctypes: 2e.:

        * The undocumented ‘ctypes.SetPointerType()’ function has been
          deprecated since Python 3.13.

   * *note http.server: 76.:

        * The obsolete and rarely used *note CGIHTTPRequestHandler: 325.
          has been deprecated since Python 3.13.  No direct replacement
          exists.  'Anything' is better than CGI to interface a web
          server with a request handler.

        * The ‘--cgi’ flag to the ‘python -m http.server’ command-line
          interface has been deprecated since Python 3.13.

   * *note importlib: 7b.:

        * ‘load_module()’ method: use ‘exec_module()’ instead.

   * *note locale: 8a.:

        * The *note getdefaultlocale(): 326. function has been
          deprecated since Python 3.11.  Its removal was originally
          planned for Python 3.13 (gh-90817(3)), but has been postponed
          to Python 3.15.  Use *note getlocale(): 327, *note
          setlocale(): 328, and *note getencoding(): 329. instead.
          (Contributed by Hugo van Kemenade in gh-111187(4).)

   * *note pathlib: a8.:

        * *note PurePath.is_reserved(): 32a. has been deprecated since
          Python 3.13.  Use *note os.path.isreserved(): 32b. to detect
          reserved paths on Windows.

   * *note platform: af.:

        * *note java_ver(): 32c. has been deprecated since Python 3.13.
          This function is only useful for Jython support, has a
          confusing API, and is largely untested.

   * *note sysconfig: e1.:

        * The 'check_home' argument of *note
          sysconfig.is_python_build(): 32d. has been deprecated since
          Python 3.12.

   * *note threading: f3.:

        * *note RLock(): 32e. will take no arguments in Python 3.15.
          Passing any arguments has been deprecated since Python 3.14,
          as the Python version does not permit any arguments, but the C
          version allows any number of positional or keyword arguments,
          ignoring every argument.

   * *note types: 109.:

        * *note types.CodeType: 32f.: Accessing *note co_lnotab: 330.
          was deprecated in PEP 626(5) since 3.10 and was planned to be
          removed in 3.12, but it only got a proper *note
          DeprecationWarning: 1a3. in 3.12.  May be removed in 3.15.
          (Contributed by Nikita Sobolev in gh-101866(6).)

   * *note typing: 10a.:

        * The undocumented keyword argument syntax for creating *note
          NamedTuple: 331. classes (for example, ‘Point =
          NamedTuple("Point", x=int, y=int)’) has been deprecated since
          Python 3.13.  Use the class-based syntax or the functional
          syntax instead.

        * When using the functional syntax of *note TypedDict: 332.s,
          failing to pass a value to the 'fields' parameter (‘TD =
          TypedDict("TD")’) or passing ‘None’ (‘TD = TypedDict("TD",
          None)’) has been deprecated since Python 3.13.  Use ‘class
          TD(TypedDict): pass’ or ‘TD = TypedDict("TD", {})’ to create a
          TypedDict with zero field.

        * The *note typing.no_type_check_decorator(): 333. decorator
          function has been deprecated since Python 3.13.  After eight
          years in the *note typing: 10a. module, it has yet to be
          supported by any major type checker.

   * *note wave: 119.:

        * The *note getmark(): 334, ‘setmark()’, and *note getmarkers():
          335. methods of the *note Wave_read: 336. and *note
          Wave_write: 337. classes have been deprecated since Python
          3.13.

   * *note zipimport: 138.:

        * *note load_module(): 338. has been deprecated since Python
          3.10.  Use *note exec_module(): 339. instead.  (Contributed by
          Jiahao Li in gh-125746(7).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97879

   (2) https://github.com/python/cpython/issues/97879

   (3) https://github.com/python/cpython/issues/90817

   (4) https://github.com/python/cpython/issues/111187

   (5) https://peps.python.org/pep-0626/

   (6) https://github.com/python/cpython/issues/101866

   (7) https://github.com/python/cpython/issues/125746


File: python.info,  Node: Pending removal in Python 3 16<3>,  Next: Pending removal in Python 3 17<2>,  Prev: Pending removal in Python 3 15<3>,  Up: New Deprecations

1.2.8.3 Pending removal in Python 3.16
......................................

   * The import system:

        * Setting *note __loader__: 33b. on a module while failing to
          set *note __spec__.loader: 33c. is deprecated.  In Python
          3.16, ‘__loader__’ will cease to be set or taken into
          consideration by the import system or the standard library.

   * *note array: 8.:

        * The ‘'u'’ format code (‘wchar_t’) has been deprecated in
          documentation since Python 3.3 and at runtime since Python
          3.13.  Use the ‘'w'’ format code (*note Py_UCS4: 33d.) for
          Unicode characters instead.

   * *note asyncio: b.:

        * ‘asyncio.iscoroutinefunction()’ is deprecated and will be
          removed in Python 3.16; use *note
          inspect.iscoroutinefunction(): 30d. instead.  (Contributed by
          Jiahao Li and Kumar Aditya in gh-122875(1).)

        * *note asyncio: b. policy system is deprecated and will be
          removed in Python 3.16.  In particular, the following classes
          and functions are deprecated:

             * *note asyncio.AbstractEventLoopPolicy: 30e.

             * *note asyncio.DefaultEventLoopPolicy: 30f.

             * *note asyncio.WindowsSelectorEventLoopPolicy: 310.

             * *note asyncio.WindowsProactorEventLoopPolicy: 311.

             * *note asyncio.get_event_loop_policy(): 312.

             * *note asyncio.set_event_loop_policy(): 313.

          Users should use *note asyncio.run(): 2f3. or *note
          asyncio.Runner: 2f5. with 'loop_factory' to use the desired
          event loop implementation.

          For example, to use *note asyncio.SelectorEventLoop: 314. on
          Windows:

               import asyncio

               async def main():
                   ...

               asyncio.run(main(), loop_factory=asyncio.SelectorEventLoop)

          (Contributed by Kumar Aditya in gh-127949(2).)

   * *note builtins: 13.:

        * Bitwise inversion on boolean types, ‘~True’ or ‘~False’ has
          been deprecated since Python 3.12, as it produces surprising
          and unintuitive results (‘-2’ and ‘-1’).  Use ‘not x’ instead
          for the logical negation of a Boolean.  In the rare case that
          you need the bitwise inversion of the underlying integer,
          convert to ‘int’ explicitly (‘~int(x)’).

   * *note functools: 63.:

        * Calling the Python implementation of *note functools.reduce():
          21a. with 'function' or 'sequence' as keyword arguments has
          been deprecated since Python 3.14.

   * *note logging: 8b.:

     Support for custom logging handlers with the 'strm' argument is
     deprecated and scheduled for removal in Python 3.16.  Define
     handlers with the 'stream' argument instead.  (Contributed by
     Mariusz Felisiak in gh-115032(3).)

   * *note mimetypes: 93.:

        * Valid extensions start with a “.” or are empty for *note
          mimetypes.MimeTypes.add_type(): 319.  Undotted extensions are
          deprecated and will raise a *note ValueError: 2ec. in Python
          3.16.  (Contributed by Hugo van Kemenade in gh-75223(4).)

   * *note shutil: ca.:

        * The ‘ExecError’ exception has been deprecated since Python
          3.14.  It has not been used by any function in ‘shutil’ since
          Python 3.4, and is now an alias of *note RuntimeError: 244.

   * *note symtable: de.:

        * The *note Class.get_methods: 31d. method has been deprecated
          since Python 3.14.

   * *note sys: df.:

        * The *note _enablelegacywindowsfsencoding(): 33e. function has
          been deprecated since Python 3.13.  Use the *note
          PYTHONLEGACYWINDOWSFSENCODING: 33f. environment variable
          instead.

   * *note sysconfig: e1.:

        * The ‘sysconfig.expand_makefile_vars()’ function has been
          deprecated since Python 3.14.  Use the ‘vars’ argument of
          *note sysconfig.get_paths(): 340. instead.

   * *note tarfile: e4.:

        * The undocumented and unused ‘TarFile.tarfile’ attribute has
          been deprecated since Python 3.13.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/122875

   (2) https://github.com/python/cpython/issues/127949

   (3) https://github.com/python/cpython/issues/115032

   (4) https://github.com/python/cpython/issues/75223


File: python.info,  Node: Pending removal in Python 3 17<2>,  Next: Pending removal in Python 3 18<3>,  Prev: Pending removal in Python 3 16<3>,  Up: New Deprecations

1.2.8.4 Pending removal in Python 3.17
......................................

   * *note collections.abc: 1f.:

        - *note collections.abc.ByteString: 342. is scheduled for
          removal in Python 3.17.

          Use ‘isinstance(obj, collections.abc.Buffer)’ to test if ‘obj’
          implements the *note buffer protocol: 260. at runtime.  For
          use in type annotations, either use *note Buffer: 343. or a
          union that explicitly specifies the types your code supports
          (e.g., ‘bytes | bytearray | memoryview’).

          ‘ByteString’ was originally intended to be an abstract class
          that would serve as a supertype of both *note bytes: 192. and
          *note bytearray: 344.  However, since the ABC never had any
          methods, knowing that an object was an instance of
          ‘ByteString’ never actually told you anything useful about the
          object.  Other common buffer types such as *note memoryview:
          165. were also never understood as subtypes of ‘ByteString’
          (either at runtime or by static type checkers).

          See PEP 688(1) for more details.  (Contributed by Shantanu
          Jain in gh-91896(2).)

   * *note typing: 10a.:

        - Before Python 3.14, old-style unions were implemented using
          the private class ‘typing._UnionGenericAlias’.  This class is
          no longer needed for the implementation, but it has been
          retained for backward compatibility, with removal scheduled
          for Python 3.17.  Users should use documented introspection
          helpers like *note typing.get_origin(): 2ab. and *note
          typing.get_args(): 2ac. instead of relying on private
          implementation details.

        - *note typing.ByteString: 345, deprecated since Python 3.9, is
          scheduled for removal in Python 3.17.

          Use ‘isinstance(obj, collections.abc.Buffer)’ to test if ‘obj’
          implements the *note buffer protocol: 260. at runtime.  For
          use in type annotations, either use *note Buffer: 343. or a
          union that explicitly specifies the types your code supports
          (e.g., ‘bytes | bytearray | memoryview’).

          ‘ByteString’ was originally intended to be an abstract class
          that would serve as a supertype of both *note bytes: 192. and
          *note bytearray: 344.  However, since the ABC never had any
          methods, knowing that an object was an instance of
          ‘ByteString’ never actually told you anything useful about the
          object.  Other common buffer types such as *note memoryview:
          165. were also never understood as subtypes of ‘ByteString’
          (either at runtime or by static type checkers).

          See PEP 688(3) for more details.  (Contributed by Shantanu
          Jain in gh-91896(4).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0688/#current-options

   (2) https://github.com/python/cpython/issues/91896

   (3) https://peps.python.org/pep-0688/#current-options

   (4) https://github.com/python/cpython/issues/91896


File: python.info,  Node: Pending removal in Python 3 18<3>,  Next: Pending removal in Python 3 19<2>,  Prev: Pending removal in Python 3 17<2>,  Up: New Deprecations

1.2.8.5 Pending removal in Python 3.18
......................................

   * *note decimal: 3a.:

        * The non-standard and undocumented *note Decimal: 1fe. format
          specifier ‘'N'’, which is only supported in the ‘decimal’
          module’s C implementation, has been deprecated since Python
          3.13.  (Contributed by Serhiy Storchaka in gh-89902(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89902


File: python.info,  Node: Pending removal in Python 3 19<2>,  Next: Pending removal in future versions<3>,  Prev: Pending removal in Python 3 18<3>,  Up: New Deprecations

1.2.8.6 Pending removal in Python 3.19
......................................

   * *note ctypes: 2e.:

        * Implicitly switching to the MSVC-compatible struct layout by
          setting *note _pack_: 317. but not *note _layout_: 1e7. on
          non-Windows platforms.


File: python.info,  Node: Pending removal in future versions<3>,  Prev: Pending removal in Python 3 19<2>,  Up: New Deprecations

1.2.8.7 Pending removal in future versions
..........................................

The following APIs will be removed in the future, although there is
currently no date scheduled for their removal.

   * *note argparse: 7.:

        * Nesting argument groups and nesting mutually exclusive groups
          are deprecated.

        * Passing the undocumented keyword argument 'prefix_chars' to
          *note add_argument_group(): 2eb. is now deprecated.

        * The *note argparse.FileType: 30c. type converter is
          deprecated.

   * *note builtins: 13.:

        * Generators: ‘throw(type, exc, tb)’ and ‘athrow(type, exc, tb)’
          signature is deprecated: use ‘throw(exc)’ and ‘athrow(exc)’
          instead, the single argument signature.

        * Currently Python accepts numeric literals immediately followed
          by keywords, for example ‘0in x’, ‘1or x’, ‘0if 1else 2’.  It
          allows confusing and ambiguous expressions like ‘[0x1for x in
          y]’ (which can be interpreted as ‘[0x1 for x in y]’ or ‘[0x1f
          or x in y]’).  A syntax warning is raised if the numeric
          literal is immediately followed by one of keywords *note and:
          349, *note else: 17c, *note for: 34a, *note if: 181, *note in:
          34b, *note is: 34c. and *note or: 34d.  In a future release it
          will be changed to a syntax error.  (gh-87999(1))

        * Support for ‘__index__()’ and ‘__int__()’ method returning
          non-int type: these methods will be required to return an
          instance of a strict subclass of *note int: 19b.

        * Support for ‘__float__()’ method returning a strict subclass
          of *note float: 196.: these methods will be required to return
          an instance of *note float: 196.

        * Support for ‘__complex__()’ method returning a strict subclass
          of *note complex: 197.: these methods will be required to
          return an instance of *note complex: 197.

        * Delegation of ‘int()’ to ‘__trunc__()’ method.

        * Passing a complex number as the 'real' or 'imag' argument in
          the *note complex(): 197. constructor is now deprecated; it
          should only be passed as a single positional argument.
          (Contributed by Serhiy Storchaka in gh-109218(2).)

   * *note calendar: 15.: ‘calendar.January’ and ‘calendar.February’
     constants are deprecated and replaced by *note calendar.JANUARY:
     34e. and *note calendar.FEBRUARY: 34f.  (Contributed by Prince
     Roshan in gh-103636(3).)

   * *note codecs: 1c.: use *note open(): 316. instead of *note
     codecs.open(): 315.  (gh-133038(4))

   * *note codeobject.co_lnotab: 330.: use the *note
     codeobject.co_lines(): 350. method instead.

   * *note datetime: 34.:

        * *note utcnow(): 351.: use
          ‘datetime.datetime.now(tz=datetime.UTC)’.

        * *note utcfromtimestamp(): 352.: use
          ‘datetime.datetime.fromtimestamp(timestamp, tz=datetime.UTC)’.

   * *note gettext: 67.: Plural value must be an integer.

   * *note importlib: 7b.:

        * *note cache_from_source(): 353. 'debug_override' parameter is
          deprecated: use the 'optimization' parameter instead.

   * *note importlib.metadata: 7e.:

        * ‘EntryPoints’ tuple interface.

        * Implicit ‘None’ on return values.

   * *note logging: 8b.: the ‘warn()’ method has been deprecated since
     Python 3.3, use *note warning(): 354. instead.

   * *note mailbox: 8f.: Use of StringIO input and text mode is
     deprecated, use BytesIO and binary mode instead.

   * *note os: a5.: Calling *note os.register_at_fork(): 355. in
     multi-threaded process.

   * ‘pydoc.ErrorDuringImport’: A tuple value for 'exc_info' parameter
     is deprecated, use an exception instance.

   * *note re: be.: More strict rules are now applied for numerical
     group references and group names in regular expressions.  Only
     sequence of ASCII digits is now accepted as a numerical reference.
     The group name in bytes patterns and replacement strings can now
     only contain ASCII letters and digits and underscore.  (Contributed
     by Serhiy Storchaka in gh-91760(5).)

   * ‘sre_compile’, ‘sre_constants’ and ‘sre_parse’ modules.

   * *note shutil: ca.: *note rmtree(): 356.”s 'onerror' parameter is
     deprecated in Python 3.12; use the 'onexc' parameter instead.

   * *note ssl: d5. options and protocols:

        * *note ssl.SSLContext: 357. without protocol argument is
          deprecated.

        * *note ssl.SSLContext: 357.: *note set_npn_protocols(): 358.
          and ‘selected_npn_protocol()’ are deprecated: use ALPN
          instead.

        * ‘ssl.OP_NO_SSL*’ options

        * ‘ssl.OP_NO_TLS*’ options

        * ‘ssl.PROTOCOL_SSLv3’

        * ‘ssl.PROTOCOL_TLS’

        * ‘ssl.PROTOCOL_TLSv1’

        * ‘ssl.PROTOCOL_TLSv1_1’

        * ‘ssl.PROTOCOL_TLSv1_2’

        * ‘ssl.TLSVersion.SSLv3’

        * ‘ssl.TLSVersion.TLSv1’

        * ‘ssl.TLSVersion.TLSv1_1’

   * *note threading: f3. methods:

        * ‘threading.Condition.notifyAll()’: use *note notify_all():
          359.

        * ‘threading.Event.isSet()’: use *note is_set(): 35a.

        * ‘threading.Thread.isDaemon()’, *note
          threading.Thread.setDaemon(): 35b.: use *note
          threading.Thread.daemon: 35c. attribute.

        * ‘threading.Thread.getName()’, *note
          threading.Thread.setName(): 35d.: use *note
          threading.Thread.name: 2a0. attribute.

        * ‘threading.currentThread()’: use *note
          threading.current_thread(): 35e.

        * ‘threading.activeCount()’: use *note threading.active_count():
          35f.

   * *note typing.Text: 360. (gh-92332(6)).

   * The internal class ‘typing._UnionGenericAlias’ is no longer used to
     implement *note typing.Union: 2a8.  To preserve compatibility with
     users using this private class, a compatibility shim will be
     provided until at least Python 3.17.  (Contributed by Jelle
     Zijlstra in gh-105499(7).)

   * *note unittest.IsolatedAsyncioTestCase: 361.: it is deprecated to
     return a value that is not ‘None’ from a test case.

   * *note urllib.parse: 110. deprecated functions: *note urlparse():
     362. instead

        * ‘splitattr()’

        * ‘splithost()’

        * ‘splitnport()’

        * ‘splitpasswd()’

        * ‘splitport()’

        * ‘splitquery()’

        * ‘splittag()’

        * ‘splittype()’

        * ‘splituser()’

        * ‘splitvalue()’

        * ‘to_bytes()’

   * *note wsgiref: 11e.: ‘SimpleHandler.stdout.write()’ should not do
     partial writes.

   * *note xml.etree.ElementTree: 12b.: Testing the truth value of an
     *note Element: 363. is deprecated.  In a future release it will
     always return ‘True’.  Prefer explicit ‘len(elem)’ or ‘elem is not
     None’ tests instead.

   * *note sys._clear_type_cache(): 292. is deprecated: use *note
     sys._clear_internal_caches(): 364. instead.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/87999

   (2) https://github.com/python/cpython/issues/109218

   (3) https://github.com/python/cpython/issues/103636

   (4) https://github.com/python/cpython/issues/133038

   (5) https://github.com/python/cpython/issues/91760

   (6) https://github.com/python/cpython/issues/92332

   (7) https://github.com/python/cpython/issues/105499


File: python.info,  Node: CPython Bytecode Changes,  Next: C API Changes,  Prev: New Deprecations,  Up: What’s New In Python 3 13

1.2.9 CPython Bytecode Changes
------------------------------

   * The oparg of *note YIELD_VALUE: 5ba. is now ‘1’ if the yield is
     part of a yield-from or await, and ‘0’ otherwise.  The oparg of
     *note RESUME: 5bb. was changed to add a bit indicating if the
     except-depth is 1, which is needed to optimize closing of
     generators.  (Contributed by Irit Katriel in gh-111354(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/111354


File: python.info,  Node: C API Changes,  Next: Build Changes,  Prev: CPython Bytecode Changes,  Up: What’s New In Python 3 13

1.2.10 C API Changes
--------------------

* Menu:

* New Features: New Features<2>.
* Changed C APIs::
* Limited C API Changes::
* Removed C APIs: Removed C APIs<2>.
* Deprecated C APIs: Deprecated C APIs<2>.


File: python.info,  Node: New Features<2>,  Next: Changed C APIs,  Up: C API Changes

1.2.10.1 New Features
.....................

   * Add the *note PyMonitoring C API: 486. for generating PEP 669(1)
     monitoring events:

        * *note PyMonitoringState: 5be.

        * *note PyMonitoring_FirePyStartEvent(): 5bf.

        * *note PyMonitoring_FirePyResumeEvent(): 5c0.

        * *note PyMonitoring_FirePyReturnEvent(): 5c1.

        * *note PyMonitoring_FirePyYieldEvent(): 5c2.

        * *note PyMonitoring_FireCallEvent(): 5c3.

        * *note PyMonitoring_FireLineEvent(): 5c4.

        * *note PyMonitoring_FireJumpEvent(): 5c5.

        * ‘PyMonitoring_FireBranchEvent’

        * *note PyMonitoring_FireCReturnEvent(): 5c6.

        * *note PyMonitoring_FirePyThrowEvent(): 5c7.

        * *note PyMonitoring_FireRaiseEvent(): 5c8.

        * *note PyMonitoring_FireCRaiseEvent(): 5c9.

        * *note PyMonitoring_FireReraiseEvent(): 5ca.

        * *note PyMonitoring_FireExceptionHandledEvent(): 5cb.

        * *note PyMonitoring_FirePyUnwindEvent(): 5cc.

        * *note PyMonitoring_FireStopIterationEvent(): 5cd.

        * *note PyMonitoring_EnterScope(): 5ce.

        * *note PyMonitoring_ExitScope(): 5cf.

     (Contributed by Irit Katriel in gh-111997(2)).

   * Add *note PyMutex: 485, a lightweight mutex that occupies a single
     byte, and the new *note PyMutex_Lock(): 5d0. and *note
     PyMutex_Unlock(): 5d1. functions.  ‘PyMutex_Lock()’ will release
     the *note GIL: 164. (if currently held) if the operation needs to
     block.  (Contributed by Sam Gross in gh-108724(3).)

   * Add the *note PyTime C API: 5d2. to provide access to system
     clocks:

        * *note PyTime_t: 5d3.

        * *note PyTime_MIN: 5d4. and *note PyTime_MAX: 5d5.

        * *note PyTime_AsSecondsDouble(): 5d6.

        * *note PyTime_Monotonic(): 5d7.

        * *note PyTime_MonotonicRaw(): 5d8.

        * *note PyTime_PerfCounter(): 5d9.

        * *note PyTime_PerfCounterRaw(): 5da.

        * *note PyTime_Time(): 5db.

        * *note PyTime_TimeRaw(): 5dc.

     (Contributed by Victor Stinner and Petr Viktorin in gh-110850(4).)

   * Add the *note PyDict_ContainsString(): 5dd. function with the same
     behavior as *note PyDict_Contains(): 5de, but 'key' is specified as
     a const char* UTF-8 encoded bytes string, rather than a *note
     PyObject: 5df.*.  (Contributed by Victor Stinner in gh-108314(5).)

   * Add the *note PyDict_GetItemRef(): 5e0. and *note
     PyDict_GetItemStringRef(): 421. functions, which behave similarly
     to *note PyDict_GetItemWithError(): 5e1, but return a *note strong
     reference: 5e2. instead of a *note borrowed reference: 3d7.
     Moreover, these functions return ‘-1’ on error, removing the need
     to check ‘PyErr_Occurred()’.  (Contributed by Victor Stinner in
     gh-106004(6).)

   * Add the *note PyDict_SetDefaultRef(): 5e3. function, which behaves
     similarly to *note PyDict_SetDefault(): 5e4, but returns a *note
     strong reference: 5e2. instead of a *note borrowed reference: 3d7.
     This function returns ‘-1’ on error, ‘0’ on insertion, and ‘1’ if
     the key was already present in the dictionary.  (Contributed by Sam
     Gross in gh-112066(7).)

   * Add the *note PyDict_Pop(): 422. and *note PyDict_PopString(): 5e5.
     functions to remove a key from a dictionary and optionally return
     the removed value.  This is similar to *note dict.pop(): 5e6,
     though there is no default value, and *note KeyError: 5e7. is not
     raised for missing keys.  (Contributed by Stefan Behnel and Victor
     Stinner in gh-111262(8).)

   * Add the *note PyMapping_GetOptionalItem(): 5e8. and *note
     PyMapping_GetOptionalItemString(): 5e9. functions as alternatives
     to *note PyObject_GetItem(): 5ea. and *note
     PyMapping_GetItemString(): 5eb. respectively.  The new functions do
     not raise *note KeyError: 5e7. if the requested key is missing from
     the mapping.  These variants are more convenient and faster if a
     missing key should not be treated as a failure.  (Contributed by
     Serhiy Storchaka in gh-106307(9).)

   * Add the *note PyObject_GetOptionalAttr(): 5ec. and *note
     PyObject_GetOptionalAttrString(): 5ed. functions as alternatives to
     *note PyObject_GetAttr(): 5ee. and *note PyObject_GetAttrString():
     5ef. respectively.  The new functions do not raise *note
     AttributeError: 5f0. if the requested attribute is not found on the
     object.  These variants are more convenient and faster if the
     missing attribute should not be treated as a failure.  (Contributed
     by Serhiy Storchaka in gh-106521(10).)

   * Add the *note PyErr_FormatUnraisable(): 5f1. function as an
     extension to *note PyErr_WriteUnraisable(): 5f2. that allows
     customizing the warning message.  (Contributed by Serhiy Storchaka
     in gh-108082(11).)

   * Add new functions that return a *note strong reference: 5e2.
     instead of a *note borrowed reference: 3d7. for frame locals,
     globals, and builtins, as part of *note PEP 667: 470.:

        * *note PyEval_GetFrameBuiltins(): 5f3. replaces *note
          PyEval_GetBuiltins(): 5f4.

        * *note PyEval_GetFrameGlobals(): 5f5. replaces *note
          PyEval_GetGlobals(): 5f6.

        * *note PyEval_GetFrameLocals(): 5f7. replaces *note
          PyEval_GetLocals(): 5f8.

     (Contributed by Mark Shannon and Tian Gao in gh-74929(12).)

   * Add the *note Py_GetConstant(): 5f9. and *note
     Py_GetConstantBorrowed(): 5fa. functions to get *note strong: 5e2.
     or *note borrowed: 3d7. references to constants.  For example,
     ‘Py_GetConstant(Py_CONSTANT_ZERO)’ returns a strong reference to
     the constant zero.  (Contributed by Victor Stinner in
     gh-115754(13).)

   * Add the *note PyImport_AddModuleRef(): 5fb. function as a
     replacement for *note PyImport_AddModule(): 5fc. that returns a
     *note strong reference: 5e2. instead of a *note borrowed reference:
     3d7.  (Contributed by Victor Stinner in gh-105922(14).)

   * Add the *note Py_IsFinalizing(): 5fd. function to check whether the
     main Python interpreter is *note shutting down: 47a.  (Contributed
     by Victor Stinner in gh-108014(15).)

   * Add the *note PyList_GetItemRef(): 5fe. function as a replacement
     for *note PyList_GetItem(): 5ff. that returns a *note strong
     reference: 5e2. instead of a *note borrowed reference: 3d7.
     (Contributed by Sam Gross in gh-114329(16).)

   * Add the *note PyList_Extend(): 600. and *note PyList_Clear(): 601.
     functions, mirroring the Python *note list.extend(): 602. and *note
     list.clear(): 603. methods.  (Contributed by Victor Stinner in
     gh-111138(17).)

   * Add the *note PyLong_AsInt(): 604. function.  It behaves similarly
     to *note PyLong_AsLong(): 605, but stores the result in a C int
     instead of a C long.  (Contributed by Victor Stinner in
     gh-108014(18).)

   * Add the *note PyLong_AsNativeBytes(): 606, *note
     PyLong_FromNativeBytes(): 607, and *note
     PyLong_FromUnsignedNativeBytes(): 608. functions to simplify
     converting between native integer types and Python *note int: 19b.
     objects.  (Contributed by Steve Dower in gh-111140(19).)

   * Add *note PyModule_Add(): 609. function, which is similar to *note
     PyModule_AddObjectRef(): 60a. and *note PyModule_AddObject(): 60b,
     but always steals a reference to the value.  (Contributed by Serhiy
     Storchaka in gh-86493(20).)

   * Add the *note PyObject_GenericHash(): 60c. function that implements
     the default hashing function of a Python object.  (Contributed by
     Serhiy Storchaka in gh-113024(21).)

   * Add the *note Py_HashPointer(): 425. function to hash a raw
     pointer.  (Contributed by Victor Stinner in gh-111545(22).)

   * Add the *note PyObject_VisitManagedDict(): 60d. and *note
     PyObject_ClearManagedDict(): 60e. functions.  which must be called
     by the traverse and clear functions of a type using the *note
     Py_TPFLAGS_MANAGED_DICT: 60f. flag.  The pythoncapi-compat
     project(23) can be used to use these functions with Python 3.11 and
     3.12.  (Contributed by Victor Stinner in gh-107073(24).)

   * Add the *note PyRefTracer_SetTracer(): 610. and *note
     PyRefTracer_GetTracer(): 611. functions, which enable tracking
     object creation and destruction in the same way that the *note
     tracemalloc: 105. module does.  (Contributed by Pablo Galindo in
     gh-93502(25).)

   * Add the *note PySys_AuditTuple(): 612. function as an alternative
     to *note PySys_Audit(): 613. that takes event arguments as a Python
     *note tuple: 614. object.  (Contributed by Victor Stinner in
     gh-85283(26).)

   * Add the *note PyThreadState_GetUnchecked(): 423. function as an
     alternative to *note PyThreadState_Get(): 615. that doesn’t kill
     the process with a fatal error if it is ‘NULL’.  The caller is
     responsible for checking if the result is ‘NULL’.  (Contributed by
     Victor Stinner in gh-108867(27).)

   * Add the *note PyType_GetFullyQualifiedName(): 616. function to get
     the type’s fully qualified name.  The module name is prepended if
     *note type.__module__: 617. is a string and is not equal to either
     ‘'builtins'’ or ‘'__main__'’.  (Contributed by Victor Stinner in
     gh-111696(28).)

   * Add the *note PyType_GetModuleName(): 618. function to get the
     type’s module name.  This is equivalent to getting the *note
     type.__module__: 617. attribute.  (Contributed by Eric Snow and
     Victor Stinner in gh-111696(29).)

   * Add the *note PyUnicode_EqualToUTF8AndSize(): 619. and *note
     PyUnicode_EqualToUTF8(): 61a. functions to compare a Unicode object
     with a const char* UTF-8 encoded string and ‘1’ if they are equal
     or ‘0’ otherwise.  These functions do not raise exceptions.
     (Contributed by Serhiy Storchaka in gh-110289(30).)

   * Add the *note PyWeakref_GetRef(): 3df. function as an alternative
     to *note PyWeakref_GetObject(): 3dd. that returns a *note strong
     reference: 5e2. or ‘NULL’ if the referent is no longer live.
     (Contributed by Victor Stinner in gh-105927(31).)

   * Add fixed variants of functions which silently ignore errors:

        * *note PyObject_HasAttrWithError(): 61b. replaces *note
          PyObject_HasAttr(): 61c.

        * *note PyObject_HasAttrStringWithError(): 61d. replaces *note
          PyObject_HasAttrString(): 61e.

        * *note PyMapping_HasKeyWithError(): 61f. replaces *note
          PyMapping_HasKey(): 620.

        * *note PyMapping_HasKeyStringWithError(): 621. replaces *note
          PyMapping_HasKeyString(): 622.

     The new functions return ‘-1’ for errors and the standard ‘1’ for
     true and ‘0’ for false.

     (Contributed by Serhiy Storchaka in gh-108511(32).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0669/

   (2) https://github.com/python/cpython/issues/111997

   (3) https://github.com/python/cpython/issues/108724

   (4) https://github.com/python/cpython/issues/110850

   (5) https://github.com/python/cpython/issues/108314

   (6) https://github.com/python/cpython/issues/106004

   (7) https://github.com/python/cpython/issues/112066

   (8) https://github.com/python/cpython/issues/111262

   (9) https://github.com/python/cpython/issues/106307

   (10) https://github.com/python/cpython/issues/106521

   (11) https://github.com/python/cpython/issues/108082

   (12) https://github.com/python/cpython/issues/74929

   (13) https://github.com/python/cpython/issues/115754

   (14) https://github.com/python/cpython/issues/105922

   (15) https://github.com/python/cpython/issues/108014

   (16) https://github.com/python/cpython/issues/114329

   (17) https://github.com/python/cpython/issues/111138

   (18) https://github.com/python/cpython/issues/108014

   (19) https://github.com/python/cpython/issues/111140

   (20) https://github.com/python/cpython/issues/86493

   (21) https://github.com/python/cpython/issues/113024

   (22) https://github.com/python/cpython/issues/111545

   (23) https://github.com/python/pythoncapi-compat/

   (24) https://github.com/python/cpython/issues/107073

   (25) https://github.com/python/cpython/issues/93502

   (26) https://github.com/python/cpython/issues/85283

   (27) https://github.com/python/cpython/issues/108867

   (28) https://github.com/python/cpython/issues/111696

   (29) https://github.com/python/cpython/issues/111696

   (30) https://github.com/python/cpython/issues/110289

   (31) https://github.com/python/cpython/issues/105927

   (32) https://github.com/python/cpython/issues/108511


File: python.info,  Node: Changed C APIs,  Next: Limited C API Changes,  Prev: New Features<2>,  Up: C API Changes

1.2.10.2 Changed C APIs
.......................

   * The 'keywords' parameter of *note PyArg_ParseTupleAndKeywords():
     624. and *note PyArg_VaParseTupleAndKeywords(): 625. now has type
     char *const* in C and const char *const* in C++, instead of char**.
     In C++, this makes these functions compatible with arguments of
     type const char *const*, const char**, or char *const* without an
     explicit type cast.  In C, the functions only support arguments of
     type char *const*.  This can be overridden with the *note
     PY_CXX_CONST: 626. macro.  (Contributed by Serhiy Storchaka in
     gh-65210(1).)

   * *note PyArg_ParseTupleAndKeywords(): 624. now supports non-ASCII
     keyword parameter names.  (Contributed by Serhiy Storchaka in
     gh-110815(2).)

   * The ‘PyCode_GetFirstFree()’ function is now unstable API and is now
     named *note PyUnstable_Code_GetFirstFree(): 627.  (Contributed by
     Bogdan Romanyuk in gh-115781(3).)

   * The *note PyDict_GetItem(): 628, *note PyDict_GetItemString(): 629,
     *note PyMapping_HasKey(): 620, *note PyMapping_HasKeyString(): 622,
     *note PyObject_HasAttr(): 61c, *note PyObject_HasAttrString(): 61e,
     and *note PySys_GetObject(): 62a. functions, each of which clears
     all errors which occurred when calling them now reports these
     errors using *note sys.unraisablehook(): 508.  You may replace them
     with other functions as recommended in the documentation.
     (Contributed by Serhiy Storchaka in gh-106672(4).)

   * Add support for the ‘%T’, ‘%#T’, ‘%N’ and ‘%#N’ formats to *note
     PyUnicode_FromFormat(): 62b.:

        * ‘%T’: Get the fully qualified name of an object type

        * ‘%#T’: As above, but use a colon as the separator

        * ‘%N’: Get the fully qualified name of a type

        * ‘%#N’: As above, but use a colon as the separator

     See PEP 737(5) for more information.  (Contributed by Victor
     Stinner in gh-111696(6).)

   * You no longer have to define the ‘PY_SSIZE_T_CLEAN’ macro before
     including ‘Python.h’ when using ‘#’ formats in *note format codes:
     62c.  APIs accepting the format codes always use ‘Py_ssize_t’ for
     ‘#’ formats.  (Contributed by Inada Naoki in gh-104922(7).)

   * If Python is built in *note debug mode: 50a. or *note with
     assertions: 62d, *note PyTuple_SET_ITEM(): 62e. and *note
     PyList_SET_ITEM(): 62f. now check the index argument with an
     assertion.  (Contributed by Victor Stinner in gh-106168(8).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/65210

   (2) https://github.com/python/cpython/issues/110815

   (3) https://github.com/python/cpython/issues/115781

   (4) https://github.com/python/cpython/issues/106672

   (5) https://peps.python.org/pep-0737/

   (6) https://github.com/python/cpython/issues/111696

   (7) https://github.com/python/cpython/issues/104922

   (8) https://github.com/python/cpython/issues/106168


File: python.info,  Node: Limited C API Changes,  Next: Removed C APIs<2>,  Prev: Changed C APIs,  Up: C API Changes

1.2.10.3 Limited C API Changes
..............................

   * The following functions are now included in the Limited C API:

        * *note PyMem_RawMalloc(): 631.

        * *note PyMem_RawCalloc(): 632.

        * *note PyMem_RawRealloc(): 633.

        * *note PyMem_RawFree(): 634.

        * *note PySys_Audit(): 613.

        * *note PySys_AuditTuple(): 612.

        * *note PyType_GetModuleByDef(): 635.

     (Contributed by Victor Stinner in gh-85283(1) and gh-116936(2).)

   * Python built with *note -with-trace-refs: 636. (tracing references)
     now supports the *note Limited API: 637.  (Contributed by Victor
     Stinner in gh-108634(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/85283

   (2) https://github.com/python/cpython/issues/116936

   (3) https://github.com/python/cpython/issues/108634


File: python.info,  Node: Removed C APIs<2>,  Next: Deprecated C APIs<2>,  Prev: Limited C API Changes,  Up: C API Changes

1.2.10.4 Removed C APIs
.......................

   * Remove several functions, macros, variables, etc with names
     prefixed by ‘_Py’ or ‘_PY’ (which are considered private).  If your
     project is affected by one of these removals and you believe that
     the removed API should remain available, please *note open a new
     issue: 557. to request a public C API and add ‘cc: @vstinner’ to
     the issue to notify Victor Stinner.  (Contributed by Victor Stinner
     in gh-106320(1).)

   * Remove old buffer protocols deprecated in Python 3.0.  Use *note
     Buffer Protocol: 260. instead.

        * ‘PyObject_CheckReadBuffer()’: Use *note
          PyObject_CheckBuffer(): 639. to test whether the object
          supports the buffer protocol.  Note that *note
          PyObject_CheckBuffer(): 639. doesn’t guarantee that *note
          PyObject_GetBuffer(): 63a. will succeed.  To test if the
          object is actually readable, see the next example of *note
          PyObject_GetBuffer(): 63a.

        * ‘PyObject_AsCharBuffer()’, ‘PyObject_AsReadBuffer()’: Use
          *note PyObject_GetBuffer(): 63a. and *note PyBuffer_Release():
          63b. instead:

               Py_buffer view;
               if (PyObject_GetBuffer(obj, &view, PyBUF_SIMPLE) < 0) {
                   return NULL;
               }
               // Use `view.buf` and `view.len` to read from the buffer.
               // You may need to cast buf as `(const char*)view.buf`.
               PyBuffer_Release(&view);

        * ‘PyObject_AsWriteBuffer()’: Use *note PyObject_GetBuffer():
          63a. and *note PyBuffer_Release(): 63b. instead:

               Py_buffer view;
               if (PyObject_GetBuffer(obj, &view, PyBUF_WRITABLE) < 0) {
                   return NULL;
               }
               // Use `view.buf` and `view.len` to write to the buffer.
               PyBuffer_Release(&view);

     (Contributed by Inada Naoki in gh-85275(2).)

   * Remove various functions deprecated in Python 3.9:

        * ‘PyEval_CallObject()’, ‘PyEval_CallObjectWithKeywords()’: Use
          *note PyObject_CallNoArgs(): 63c. or *note PyObject_Call():
          63d. instead.

               Avvertimento: In *note PyObject_Call(): 63d, positional
               arguments must be a *note tuple: 614. and must not be
               ‘NULL’, and keyword arguments must be a *note dict: 183.
               or ‘NULL’, whereas the removed functions checked argument
               types and accepted ‘NULL’ positional and keyword
               arguments.  To replace
               ‘PyEval_CallObjectWithKeywords(func, NULL, kwargs)’ with
               *note PyObject_Call(): 63d, pass an empty tuple as
               positional arguments using *note PyTuple_New(0): 63e.

        * ‘PyEval_CallFunction()’: Use *note PyObject_CallFunction():
          63f. instead.

        * ‘PyEval_CallMethod()’: Use *note PyObject_CallMethod(): 640.
          instead.

        * ‘PyCFunction_Call()’: Use *note PyObject_Call(): 63d. instead.

     (Contributed by Victor Stinner in gh-105107(3).)

   * Remove the following old functions to configure the Python
     initialization, deprecated in Python 3.11:

        * ‘PySys_AddWarnOptionUnicode()’: Use *note
          PyConfig.warnoptions: 641. instead.

        * ‘PySys_AddWarnOption()’: Use *note PyConfig.warnoptions: 641.
          instead.

        * ‘PySys_AddXOption()’: Use *note PyConfig.xoptions: 642.
          instead.

        * ‘PySys_HasWarnOptions()’: Use *note PyConfig.xoptions: 642.
          instead.

        * ‘PySys_SetPath()’: Set *note PyConfig.module_search_paths:
          643. instead.

        * ‘Py_SetPath()’: Set *note PyConfig.module_search_paths: 643.
          instead.

        * ‘Py_SetStandardStreamEncoding()’: Set *note
          PyConfig.stdio_encoding: 644. instead, and set also maybe
          *note PyConfig.legacy_windows_stdio: 41a. (on Windows).

        * ‘_Py_SetProgramFullPath()’: Set *note PyConfig.executable:
          645. instead.

     Use the new *note PyConfig: 3f7. API of the *note Python
     Initialization Configuration: 646. instead ( PEP 587(4)), added to
     Python 3.8.  (Contributed by Victor Stinner in gh-105145(5).)

   * Remove ‘PyEval_AcquireLock()’ and ‘PyEval_ReleaseLock()’ functions,
     deprecated in Python 3.2.  They didn’t update the current thread
     state.  They can be replaced with:

        * *note PyEval_SaveThread(): 647. and *note
          PyEval_RestoreThread(): 648.;

        * low-level *note PyEval_AcquireThread(): 649. and *note
          PyEval_RestoreThread(): 648.;

        * or *note PyGILState_Ensure(): 64a. and *note
          PyGILState_Release(): 64b.

     (Contributed by Victor Stinner in gh-105182(6).)

   * Remove the ‘PyEval_ThreadsInitialized()’ function, deprecated in
     Python 3.9.  Since Python 3.7, ‘Py_Initialize()’ always creates the
     GIL: calling ‘PyEval_InitThreads()’ does nothing and
     ‘PyEval_ThreadsInitialized()’ always returns non-zero.
     (Contributed by Victor Stinner in gh-105182(7).)

   * Remove the ‘_PyInterpreterState_Get()’ alias to *note
     PyInterpreterState_Get(): 64c. which was kept for backward
     compatibility with Python 3.8.  The pythoncapi-compat project(8)
     can be used to get *note PyInterpreterState_Get(): 64c. on Python
     3.8 and older.  (Contributed by Victor Stinner in gh-106320(9).)

   * Remove the private ‘_PyObject_FastCall()’ function: use
     ‘PyObject_Vectorcall()’ which is available since Python 3.8 ( PEP
     590(10)).  (Contributed by Victor Stinner in gh-106023(11).)

   * Remove the ‘cpython/pytime.h’ header file, which only contained
     private functions.  (Contributed by Victor Stinner in
     gh-106316(12).)

   * Remove the undocumented ‘PY_TIMEOUT_MAX’ constant from the limited
     C API. (Contributed by Victor Stinner in gh-110014(13).)

   * Remove the old trashcan macros ‘Py_TRASHCAN_SAFE_BEGIN’ and
     ‘Py_TRASHCAN_SAFE_END’.  Replace both with the new macros
     ‘Py_TRASHCAN_BEGIN’ and ‘Py_TRASHCAN_END’.  (Contributed by Irit
     Katriel in gh-105111(14).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/106320

   (2) https://github.com/python/cpython/issues/85275

   (3) https://github.com/python/cpython/issues/105107

   (4) https://peps.python.org/pep-0587/

   (5) https://github.com/python/cpython/issues/105145

   (6) https://github.com/python/cpython/issues/105182

   (7) https://github.com/python/cpython/issues/105182

   (8) https://github.com/python/pythoncapi-compat/

   (9) https://github.com/python/cpython/issues/106320

   (10) https://peps.python.org/pep-0590/

   (11) https://github.com/python/cpython/issues/106023

   (12) https://github.com/python/cpython/issues/106316

   (13) https://github.com/python/cpython/issues/110014

   (14) https://github.com/python/cpython/issues/105111


File: python.info,  Node: Deprecated C APIs<2>,  Prev: Removed C APIs<2>,  Up: C API Changes

1.2.10.5 Deprecated C APIs
..........................

   * Deprecate old Python initialization functions:

        * *note PySys_ResetWarnOptions(): 3f4.: Clear *note
          sys.warnoptions: 3f5. and ‘warnings.filters’ instead.

        * *note Py_GetExecPrefix(): 3e9.: Get *note sys.exec_prefix:
          3eb. instead.

        * *note Py_GetPath(): 3e3.: Get *note sys.path: 3e4. instead.

        * *note Py_GetPrefix(): 3e5.: Get *note sys.prefix: 3e7.
          instead.

        * *note Py_GetProgramFullPath(): 3ec.: Get *note sys.executable:
          3ed. instead.

        * *note Py_GetProgramName(): 3ee.: Get *note sys.executable:
          3ed. instead.

        * *note Py_GetPythonHome(): 3ef.: Get *note PyConfig.home: 3f3.
          or the *note PYTHONHOME: 3f0. environment variable instead.

     (Contributed by Victor Stinner in gh-105145(1).)

   * *note Soft deprecate: 23d. the *note PyEval_GetBuiltins(): 5f4,
     *note PyEval_GetGlobals(): 5f6, and *note PyEval_GetLocals(): 5f8.
     functions, which return a *note borrowed reference: 3d7.  (Soft
     deprecated as part of PEP 667(2).)

   * Deprecate the *note PyImport_ImportModuleNoBlock(): 3db. function,
     which is just an alias to *note PyImport_ImportModule(): 3dc. since
     Python 3.3.  (Contributed by Victor Stinner in gh-105396(3).)

   * *note Soft deprecate: 23d. the *note PyModule_AddObject(): 60b.
     function.  It should be replaced with *note PyModule_Add(): 609. or
     *note PyModule_AddObjectRef(): 60a.  (Contributed by Serhiy
     Storchaka in gh-86493(4).)

   * Deprecate the old ‘Py_UNICODE’ and ‘PY_UNICODE_TYPE’ types and the
     ‘Py_UNICODE_WIDE’ define.  Use the ‘wchar_t’ type directly instead.
     Since Python 3.3, ‘Py_UNICODE’ and ‘PY_UNICODE_TYPE’ are just
     aliases to ‘wchar_t’.  (Contributed by Victor Stinner in
     gh-105156(5).)

   * Deprecate the *note PyWeakref_GetObject(): 3dd. and *note
     PyWeakref_GET_OBJECT(): 3de. functions, which return a *note
     borrowed reference: 3d7.  Replace them with the new *note
     PyWeakref_GetRef(): 3df. function, which returns a *note strong
     reference: 5e2.  The pythoncapi-compat project(6) can be used to
     get *note PyWeakref_GetRef(): 3df. on Python 3.12 and older.
     (Contributed by Victor Stinner in gh-105927(7).)

* Menu:

* Pending removal in Python 3.14: Pending removal in Python 3 14<2>.
* Pending removal in Python 3.15: Pending removal in Python 3 15<4>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<4>.
* Pending removal in Python 3.18: Pending removal in Python 3 18<4>.
* Pending removal in future versions: Pending removal in future versions<4>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/105145

   (2) https://peps.python.org/pep-0667/

   (3) https://github.com/python/cpython/issues/105396

   (4) https://github.com/python/cpython/issues/86493

   (5) https://github.com/python/cpython/issues/105156

   (6) https://github.com/python/pythoncapi-compat/

   (7) https://github.com/python/cpython/issues/105927


File: python.info,  Node: Pending removal in Python 3 14<2>,  Next: Pending removal in Python 3 15<4>,  Up: Deprecated C APIs<2>

1.2.10.6 Pending removal in Python 3.14
.......................................

   * The ‘ma_version_tag’ field in *note PyDictObject: 64f. for
     extension modules ( PEP 699(1); gh-101193(2)).

   * Creating *note immutable types: 3cf. with mutable bases
     (gh-95388(3)).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0699/

   (2) https://github.com/python/cpython/issues/101193

   (3) https://github.com/python/cpython/issues/95388


File: python.info,  Node: Pending removal in Python 3 15<4>,  Next: Pending removal in Python 3 16<4>,  Prev: Pending removal in Python 3 14<2>,  Up: Deprecated C APIs<2>

1.2.10.7 Pending removal in Python 3.15
.......................................

   * The *note PyImport_ImportModuleNoBlock(): 3db.: Use *note
     PyImport_ImportModule(): 3dc. instead.

   * *note PyWeakref_GetObject(): 3dd. and *note PyWeakref_GET_OBJECT():
     3de.: Use *note PyWeakref_GetRef(): 3df. instead.  The
     pythoncapi-compat project(1) can be used to get *note
     PyWeakref_GetRef(): 3df. on Python 3.12 and older.

   * *note Py_UNICODE: 3e0. type and the ‘Py_UNICODE_WIDE’ macro: Use
     ‘wchar_t’ instead.

   * ‘PyUnicode_AsDecodedObject()’: Use *note PyCodec_Decode(): 3e1.
     instead.

   * ‘PyUnicode_AsDecodedUnicode()’: Use *note PyCodec_Decode(): 3e1.
     instead; Note that some codecs (for example, «base64») may return a
     type other than *note str: 169, such as *note bytes: 192.

   * ‘PyUnicode_AsEncodedObject()’: Use *note PyCodec_Encode(): 3e2.
     instead.

   * ‘PyUnicode_AsEncodedUnicode()’: Use *note PyCodec_Encode(): 3e2.
     instead; Note that some codecs (for example, «base64») may return a
     type other than *note bytes: 192, such as *note str: 169.

   * Python initialization functions, deprecated in Python 3.13:

        * *note Py_GetPath(): 3e3.: Use *note
          PyConfig_Get("module_search_paths"): 37c. (*note sys.path:
          3e4.) instead.

        * *note Py_GetPrefix(): 3e5.: Use *note
          PyConfig_Get("base_prefix"): 37c. (*note sys.base_prefix:
          3e6.) instead.  Use *note PyConfig_Get("prefix"): 37c. (*note
          sys.prefix: 3e7.) if *note virtual environments: 3e8. need to
          be handled.

        * *note Py_GetExecPrefix(): 3e9.: Use *note
          PyConfig_Get("base_exec_prefix"): 37c. (*note
          sys.base_exec_prefix: 3ea.) instead.  Use *note
          PyConfig_Get("exec_prefix"): 37c. (*note sys.exec_prefix:
          3eb.) if *note virtual environments: 3e8. need to be handled.

        * *note Py_GetProgramFullPath(): 3ec.: Use *note
          PyConfig_Get("executable"): 37c. (*note sys.executable: 3ed.)
          instead.

        * *note Py_GetProgramName(): 3ee.: Use *note
          PyConfig_Get("executable"): 37c. (*note sys.executable: 3ed.)
          instead.

        * *note Py_GetPythonHome(): 3ef.: Use *note
          PyConfig_Get("home"): 37c. or the *note PYTHONHOME: 3f0.
          environment variable instead.

     The pythoncapi-compat project(2) can be used to get *note
     PyConfig_Get(): 37c. on Python 3.13 and older.

   * Functions to configure Python’s initialization, deprecated in
     Python 3.11:

        * ‘PySys_SetArgvEx()’: Set *note PyConfig.argv: 3f1. instead.

        * ‘PySys_SetArgv()’: Set *note PyConfig.argv: 3f1. instead.

        * ‘Py_SetProgramName()’: Set *note PyConfig.program_name: 3f2.
          instead.

        * ‘Py_SetPythonHome()’: Set *note PyConfig.home: 3f3. instead.

        * *note PySys_ResetWarnOptions(): 3f4.: Clear *note
          sys.warnoptions: 3f5. and ‘warnings.filters’ instead.

     The *note Py_InitializeFromConfig(): 3f6. API should be used with
     *note PyConfig: 3f7. instead.

   * Global configuration variables:

        * *note Py_DebugFlag: 3f8.: Use *note PyConfig.parser_debug:
          3f9. or *note PyConfig_Get("parser_debug"): 37c. instead.

        * *note Py_VerboseFlag: 3fa.: Use *note PyConfig.verbose: 3fb.
          or *note PyConfig_Get("verbose"): 37c. instead.

        * *note Py_QuietFlag: 3fc.: Use *note PyConfig.quiet: 3fd. or
          *note PyConfig_Get("quiet"): 37c. instead.

        * *note Py_InteractiveFlag: 3fe.: Use *note
          PyConfig.interactive: 3ff. or *note
          PyConfig_Get("interactive"): 37c. instead.

        * *note Py_InspectFlag: 400.: Use *note PyConfig.inspect: 401.
          or *note PyConfig_Get("inspect"): 37c. instead.

        * *note Py_OptimizeFlag: 402.: Use *note
          PyConfig.optimization_level: 403. or *note
          PyConfig_Get("optimization_level"): 37c. instead.

        * *note Py_NoSiteFlag: 404.: Use *note PyConfig.site_import:
          405. or *note PyConfig_Get("site_import"): 37c. instead.

        * *note Py_BytesWarningFlag: 406.: Use *note
          PyConfig.bytes_warning: 407. or *note
          PyConfig_Get("bytes_warning"): 37c. instead.

        * *note Py_FrozenFlag: 408.: Use *note
          PyConfig.pathconfig_warnings: 409. or *note
          PyConfig_Get("pathconfig_warnings"): 37c. instead.

        * *note Py_IgnoreEnvironmentFlag: 40a.: Use *note
          PyConfig.use_environment: 40b. or *note
          PyConfig_Get("use_environment"): 37c. instead.

        * *note Py_DontWriteBytecodeFlag: 40c.: Use *note
          PyConfig.write_bytecode: 40d. or *note
          PyConfig_Get("write_bytecode"): 37c. instead.

        * *note Py_NoUserSiteDirectory: 40e.: Use *note
          PyConfig.user_site_directory: 40f. or *note
          PyConfig_Get("user_site_directory"): 37c. instead.

        * *note Py_UnbufferedStdioFlag: 410.: Use *note
          PyConfig.buffered_stdio: 411. or *note
          PyConfig_Get("buffered_stdio"): 37c. instead.

        * *note Py_HashRandomizationFlag: 412.: Use *note
          PyConfig.use_hash_seed: 413. and *note PyConfig.hash_seed:
          414. or *note PyConfig_Get("hash_seed"): 37c. instead.

        * *note Py_IsolatedFlag: 415.: Use *note PyConfig.isolated: 416.
          or *note PyConfig_Get("isolated"): 37c. instead.

        * *note Py_LegacyWindowsFSEncodingFlag: 417.: Use *note
          PyPreConfig.legacy_windows_fs_encoding: 418. or *note
          PyConfig_Get("legacy_windows_fs_encoding"): 37c. instead.

        * *note Py_LegacyWindowsStdioFlag: 419.: Use *note
          PyConfig.legacy_windows_stdio: 41a. or *note
          PyConfig_Get("legacy_windows_stdio"): 37c. instead.

        * ‘Py_FileSystemDefaultEncoding’,
          ‘Py_HasFileSystemDefaultEncoding’: Use *note
          PyConfig.filesystem_encoding: 41b. or *note
          PyConfig_Get("filesystem_encoding"): 37c. instead.

        * ‘Py_FileSystemDefaultEncodeErrors’: Use *note
          PyConfig.filesystem_errors: 41c. or *note
          PyConfig_Get("filesystem_errors"): 37c. instead.

        * ‘Py_UTF8Mode’: Use *note PyPreConfig.utf8_mode: 41d. or *note
          PyConfig_Get("utf8_mode"): 37c. instead.  (see *note
          Py_PreInitialize(): 41e.)

     The *note Py_InitializeFromConfig(): 3f6. API should be used with
     *note PyConfig: 3f7. to set these options.  Or *note
     PyConfig_Get(): 37c. can be used to get these options at runtime.

   ---------- Footnotes ----------

   (1) https://github.com/python/pythoncapi-compat/

   (2) https://github.com/python/pythoncapi-compat/


File: python.info,  Node: Pending removal in Python 3 16<4>,  Next: Pending removal in Python 3 18<4>,  Prev: Pending removal in Python 3 15<4>,  Up: Deprecated C APIs<2>

1.2.10.8 Pending removal in Python 3.16
.......................................

   * The bundled copy of ‘libmpdec’.


File: python.info,  Node: Pending removal in Python 3 18<4>,  Next: Pending removal in future versions<4>,  Prev: Pending removal in Python 3 16<4>,  Up: Deprecated C APIs<2>

1.2.10.9 Pending removal in Python 3.18
.......................................

   * The following private functions are deprecated and planned for
     removal in Python 3.18:

        * ‘_PyBytes_Join()’: use *note PyBytes_Join(): 383.

        * ‘_PyDict_GetItemStringWithError()’: use *note
          PyDict_GetItemStringRef(): 421.

        * ‘_PyDict_Pop()’: use *note PyDict_Pop(): 422.

        * ‘_PyLong_Sign()’: use *note PyLong_GetSign(): 39a.

        * ‘_PyLong_FromDigits()’ and ‘_PyLong_New()’: use *note
          PyLongWriter_Create(): 3aa.

        * ‘_PyThreadState_UncheckedGet()’: use *note
          PyThreadState_GetUnchecked(): 423.

        * ‘_PyUnicode_AsString()’: use *note PyUnicode_AsUTF8(): 424.

        * ‘_PyUnicodeWriter_Init()’: replace
          ‘_PyUnicodeWriter_Init(&writer)’ with *note writer =
          PyUnicodeWriter_Create(0): 3b4.

        * ‘_PyUnicodeWriter_Finish()’: replace
          ‘_PyUnicodeWriter_Finish(&writer)’ with *note
          PyUnicodeWriter_Finish(writer): 3b7.

        * ‘_PyUnicodeWriter_Dealloc()’: replace
          ‘_PyUnicodeWriter_Dealloc(&writer)’ with *note
          PyUnicodeWriter_Discard(writer): 3b6.

        * ‘_PyUnicodeWriter_WriteChar()’: replace
          ‘_PyUnicodeWriter_WriteChar(&writer, ch)’ with *note
          PyUnicodeWriter_WriteChar(writer, ch): 3ba.

        * ‘_PyUnicodeWriter_WriteStr()’: replace
          ‘_PyUnicodeWriter_WriteStr(&writer, str)’ with *note
          PyUnicodeWriter_WriteStr(writer, str): 3bc.

        * ‘_PyUnicodeWriter_WriteSubstring()’: replace
          ‘_PyUnicodeWriter_WriteSubstring(&writer, str, start, end)’
          with *note PyUnicodeWriter_WriteSubstring(writer, str, start,
          end): 3bd.

        * ‘_PyUnicodeWriter_WriteASCIIString()’: replace
          ‘_PyUnicodeWriter_WriteASCIIString(&writer, str)’ with *note
          PyUnicodeWriter_WriteASCII(writer, str): 3b9.

        * ‘_PyUnicodeWriter_WriteLatin1String()’: replace
          ‘_PyUnicodeWriter_WriteLatin1String(&writer, str)’ with *note
          PyUnicodeWriter_WriteUTF8(writer, str): 3bf.

        * ‘_PyUnicodeWriter_Prepare()’: (no replacement).

        * ‘_PyUnicodeWriter_PrepareKind()’: (no replacement).

        * ‘_Py_HashPointer()’: use *note Py_HashPointer(): 425.

        * ‘_Py_fopen_obj()’: use *note Py_fopen(): 393.

     The pythoncapi-compat project(1) can be used to get these new
     public functions on Python 3.13 and older.  (Contributed by Victor
     Stinner in gh-128863(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/pythoncapi-compat/

   (2) https://github.com/python/cpython/issues/128863


File: python.info,  Node: Pending removal in future versions<4>,  Prev: Pending removal in Python 3 18<4>,  Up: Deprecated C APIs<2>

1.2.10.10 Pending removal in future versions
............................................

The following APIs are deprecated and will be removed, although there is
currently no date scheduled for their removal.

   * *note Py_TPFLAGS_HAVE_FINALIZE: 427.: Unneeded since Python 3.8.

   * *note PyErr_Fetch(): 428.: Use *note PyErr_GetRaisedException():
     429. instead.

   * *note PyErr_NormalizeException(): 42a.: Use *note
     PyErr_GetRaisedException(): 429. instead.

   * *note PyErr_Restore(): 42b.: Use *note PyErr_SetRaisedException():
     42c. instead.

   * *note PyModule_GetFilename(): 42d.: Use *note
     PyModule_GetFilenameObject(): 42e. instead.

   * *note PyOS_AfterFork(): 42f.: Use *note PyOS_AfterFork_Child():
     430. instead.

   * *note PySlice_GetIndicesEx(): 431.: Use *note PySlice_Unpack():
     432. and *note PySlice_AdjustIndices(): 433. instead.

   * *note PyUnicode_READY(): 434.: Unneeded since Python 3.12

   * ‘PyErr_Display()’: Use *note PyErr_DisplayException(): 435.
     instead.

   * ‘_PyErr_ChainExceptions()’: Use ‘_PyErr_ChainExceptions1()’
     instead.

   * ‘PyBytesObject.ob_shash’ member: call *note PyObject_Hash(): 436.
     instead.

   * Thread Local Storage (TLS) API:

        * *note PyThread_create_key(): 437.: Use *note
          PyThread_tss_alloc(): 438. instead.

        * *note PyThread_delete_key(): 439.: Use *note
          PyThread_tss_free(): 43a. instead.

        * *note PyThread_set_key_value(): 43b.: Use *note
          PyThread_tss_set(): 43c. instead.

        * *note PyThread_get_key_value(): 43d.: Use *note
          PyThread_tss_get(): 43e. instead.

        * *note PyThread_delete_key_value(): 43f.: Use *note
          PyThread_tss_delete(): 440. instead.

        * *note PyThread_ReInitTLS(): 441.: Unneeded since Python 3.7.


File: python.info,  Node: Build Changes,  Next: Porting to Python 3 13,  Prev: C API Changes,  Up: What’s New In Python 3 13

1.2.11 Build Changes
--------------------

   * ‘arm64-apple-ios’ and ‘arm64-apple-ios-simulator’ are both now PEP
     11(1) tier 3 platforms.  (*note PEP 730: 48e. written and
     implementation contributed by Russell Keith-Magee in gh-114099(2).)

   * ‘aarch64-linux-android’ and ‘x86_64-linux-android’ are both now PEP
     11(3) tier 3 platforms.  (*note PEP 738: 48e. written and
     implementation contributed by Malcolm Smith in gh-116622(4).)

   * ‘wasm32-wasi’ is now a PEP 11(5) tier 2 platform.  (Contributed by
     Brett Cannon in gh-115192(6).)

   * ‘wasm32-emscripten’ is no longer a PEP 11(7) supported platform.
     (Contributed by Brett Cannon in gh-115192(8).)

   * Building CPython now requires a compiler with support for the C11
     atomic library, GCC built-in atomic functions, or MSVC interlocked
     intrinsics.

   * Autoconf 2.71 and aclocal 1.16.5 are now required to regenerate the
     ‘configure’ script.  (Contributed by Christian Heimes in
     gh-89886(9) and by Victor Stinner in gh-112090(10).)

   * SQLite 3.15.2 or newer is required to build the *note sqlite3: d4.
     extension module.  (Contributed by Erlend Aasland in
     gh-105875(11).)

   * CPython now bundles the mimalloc library(12) by default.  It is
     licensed under the MIT license; see *note mimalloc license: 656.
     The bundled mimalloc has custom changes, see gh-113141(13) for
     details.  (Contributed by Dino Viehland in gh-109914(14).)

   * The ‘configure’ option *note -with-system-libmpdec: 657. now
     defaults to ‘yes’.  The bundled copy of ‘libmpdec’ will be removed
     in Python 3.16.

   * Python built with ‘configure’ *note -with-trace-refs: 636. (tracing
     references) is now ABI compatible with the Python release build and
     *note debug build: 50a.  (Contributed by Victor Stinner in
     gh-108634(15).)

   * On POSIX systems, the pkg-config (‘.pc’) filenames now include the
     ABI flags.  For example, the free-threaded build generates
     ‘python-3.13t.pc’ and the debug build generates ‘python-3.13d.pc’.

   * The ‘errno’, ‘fcntl’, ‘grp’, ‘md5’, ‘pwd’, ‘resource’, ‘termios’,
     ‘winsound’, ‘_ctypes_test’, ‘_multiprocessing.posixshmem’,
     ‘_scproxy’, ‘_stat’, ‘_statistics’, ‘_testconsole’,
     ‘_testimportmultiple’ and ‘_uuid’ C extensions are now built with
     the *note limited C API: 637.  (Contributed by Victor Stinner in
     gh-85283(16).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0011/

   (2) https://github.com/python/cpython/issues/114099

   (3) https://peps.python.org/pep-0011/

   (4) https://github.com/python/cpython/issues/116622

   (5) https://peps.python.org/pep-0011/

   (6) https://github.com/python/cpython/issues/115192

   (7) https://peps.python.org/pep-0011/

   (8) https://github.com/python/cpython/issues/115192

   (9) https://github.com/python/cpython/issues/89886

   (10) https://github.com/python/cpython/issues/112090

   (11) https://github.com/python/cpython/issues/105875

   (12) https://github.com/microsoft/mimalloc/

   (13) https://github.com/python/cpython/issues/113141

   (14) https://github.com/python/cpython/issues/109914

   (15) https://github.com/python/cpython/issues/108634

   (16) https://github.com/python/cpython/issues/85283


File: python.info,  Node: Porting to Python 3 13,  Next: Regression Test Changes,  Prev: Build Changes,  Up: What’s New In Python 3 13

1.2.12 Porting to Python 3.13
-----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code.

* Menu:

* Changes in the Python API: Changes in the Python API<2>.
* Changes in the C API: Changes in the C API<2>.


File: python.info,  Node: Changes in the Python API<2>,  Next: Changes in the C API<2>,  Up: Porting to Python 3 13

1.2.12.1 Changes in the Python API
..................................

   * *note PEP 667: 470. introduces several changes to the semantics of
     *note locals(): 46f. and *note f_locals: 4a6.:

        * Calling *note locals(): 46f. in an *note optimized scope: 4a2.
          now produces an independent snapshot on each call, and hence
          no longer implicitly updates previously returned references.
          Obtaining the legacy CPython behavior now requires explicit
          calls to update the initially returned dictionary with the
          results of subsequent calls to ‘locals()’.  Code execution
          functions that implicitly target ‘locals()’ (such as ‘exec’
          and ‘eval’) must be passed an explicit namespace to access
          their results in an optimized scope.  (Changed as part of PEP
          667(1).)

        * Calling *note locals(): 46f. from a comprehension at module or
          class scope (including via ‘exec’ or ‘eval’) once more behaves
          as if the comprehension were running as an independent nested
          function (i.e.  the local variables from the containing scope
          are not included).  In Python 3.12, this had changed to
          include the local variables from the containing scope when
          implementing PEP 709(2).  (Changed as part of PEP 667(3).)

        * Accessing *note FrameType.f_locals: 4a6. in an *note optimized
          scope: 4a2. now returns a write-through proxy rather than a
          snapshot that gets updated at ill-specified times.  If a
          snapshot is desired, it must be created explicitly with ‘dict’
          or the proxy’s ‘.copy()’ method.  (Changed as part of PEP
          667(4).)

   * *note functools.partial: 217. now emits a *note FutureWarning: 659.
     when used as a method.  The behavior will change in future Python
     versions.  Wrap it in *note staticmethod(): 453. if you want to
     preserve the old behavior.  (Contributed by Serhiy Storchaka in
     gh-121027(5).)

   * An *note OSError: 2c0. is now raised by *note getpass.getuser():
     65a. for any failure to retrieve a username, instead of *note
     ImportError: 65b. on non-Unix platforms or *note KeyError: 5e7. on
     Unix platforms where the password database is empty.

   * The value of the ‘mode’ attribute of *note gzip.GzipFile: 65c. is
     now a string (‘'rb'’ or ‘'wb'’) instead of an integer (‘1’ or ‘2’).
     The value of the ‘mode’ attribute of the readable file-like object
     returned by *note zipfile.ZipFile.open(): 65d. is now ‘'rb'’
     instead of ‘'r'’.  (Contributed by Serhiy Storchaka in
     gh-115961(6).)

   * *note mailbox.Maildir: 65e. now ignores files with a leading dot
     (‘.’).  (Contributed by Zackery Spytz in gh-65559(7).)

   * *note pathlib.Path.glob(): 538. and *note rglob(): 539. now return
     both files and directories if a pattern that ends with «‘**’» is
     given, rather than directories only.  Add a trailing slash to keep
     the previous behavior and only match directories.

   * The *note threading: f3. module now expects the ‘_thread’ module to
     have an ‘_is_main_interpreter()’ function.  This function takes no
     arguments and returns ‘True’ if the current interpreter is the main
     interpreter.

     Any library or application that provides a custom ‘_thread’ module
     must provide ‘_is_main_interpreter()’, just like the module’s other
     «private» attributes.  (gh-112826(8).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0667/

   (2) https://peps.python.org/pep-0709/

   (3) https://peps.python.org/pep-0667/

   (4) https://peps.python.org/pep-0667/

   (5) https://github.com/python/cpython/issues/121027

   (6) https://github.com/python/cpython/issues/115961

   (7) https://github.com/python/cpython/issues/65559

   (8) https://github.com/python/cpython/issues/112826


File: python.info,  Node: Changes in the C API<2>,  Prev: Changes in the Python API<2>,  Up: Porting to Python 3 13

1.2.12.2 Changes in the C API
.............................

   * ‘Python.h’ no longer includes the ‘<ieeefp.h>’ standard header.  It
     was included for the ‘finite()’ function which is now provided by
     the ‘<math.h>’ header.  It should now be included explicitly if
     needed.  Remove also the ‘HAVE_IEEEFP_H’ macro.  (Contributed by
     Victor Stinner in gh-108765(1).)

   * ‘Python.h’ no longer includes these standard header files:
     ‘<time.h>’, ‘<sys/select.h>’ and ‘<sys/time.h>’.  If needed, they
     should now be included explicitly.  For example, ‘<time.h>’
     provides the ‘clock()’ and ‘gmtime()’ functions, ‘<sys/select.h>’
     provides the ‘select()’ function, and ‘<sys/time.h>’ provides the
     ‘futimes()’, ‘gettimeofday()’ and ‘setitimer()’ functions.
     (Contributed by Victor Stinner in gh-108765(2).)

   * On Windows, ‘Python.h’ no longer includes the ‘<stddef.h>’ standard
     header file.  If needed, it should now be included explicitly.  For
     example, it provides ‘offsetof()’ function, and ‘size_t’ and
     ‘ptrdiff_t’ types.  Including ‘<stddef.h>’ explicitly was already
     needed by all other platforms, the ‘HAVE_STDDEF_H’ macro is only
     defined on Windows.  (Contributed by Victor Stinner in
     gh-108765(3).)

   * If the *note Py_LIMITED_API: 660. macro is defined,
     ‘Py_BUILD_CORE’, ‘Py_BUILD_CORE_BUILTIN’ and ‘Py_BUILD_CORE_MODULE’
     macros are now undefined by ‘<Python.h>’.  (Contributed by Victor
     Stinner in gh-85283(4).)

   * The old trashcan macros ‘Py_TRASHCAN_SAFE_BEGIN’ and
     ‘Py_TRASHCAN_SAFE_END’ were removed.  They should be replaced by
     the new macros ‘Py_TRASHCAN_BEGIN’ and ‘Py_TRASHCAN_END’.

     A ‘tp_dealloc’ function that has the old macros, such as:

          static void
          mytype_dealloc(mytype *p)
          {
              PyObject_GC_UnTrack(p);
              Py_TRASHCAN_SAFE_BEGIN(p);
              ...
              Py_TRASHCAN_SAFE_END
          }

     should migrate to the new macros as follows:

          static void
          mytype_dealloc(mytype *p)
          {
              PyObject_GC_UnTrack(p);
              Py_TRASHCAN_BEGIN(p, mytype_dealloc)
              ...
              Py_TRASHCAN_END
          }

     Note that ‘Py_TRASHCAN_BEGIN’ has a second argument which should be
     the deallocation function it is in.  The new macros were added in
     Python 3.8 and the old macros were deprecated in Python 3.11.
     (Contributed by Irit Katriel in gh-105111(5).)

   * *note PEP 667: 470. introduces several changes to frame-related
     functions:

        * The effects of mutating the dictionary returned from *note
          PyEval_GetLocals(): 5f8. in an *note optimized scope: 4a2.
          have changed.  New dict entries added this way will now 'only'
          be visible to subsequent *note PyEval_GetLocals(): 5f8. calls
          in that frame, as *note PyFrame_GetLocals(): 661, *note
          locals(): 46f, and *note FrameType.f_locals: 4a6. no longer
          access the same underlying cached dictionary.  Changes made to
          entries for actual variable names and names added via the
          write-through proxy interfaces will be overwritten on
          subsequent calls to *note PyEval_GetLocals(): 5f8. in that
          frame.  The recommended code update depends on how the
          function was being used, so refer to the deprecation notice on
          the function for details.

        * Calling *note PyFrame_GetLocals(): 661. in an *note optimized
          scope: 4a2. now returns a write-through proxy rather than a
          snapshot that gets updated at ill-specified times.  If a
          snapshot is desired, it must be created explicitly (e.g.  with
          *note PyDict_Copy(): 662.), or by calling the new *note
          PyEval_GetFrameLocals(): 5f7. API.

        * ‘PyFrame_FastToLocals()’ and ‘PyFrame_FastToLocalsWithError()’
          no longer have any effect.  Calling these functions has been
          redundant since Python 3.11, when *note PyFrame_GetLocals():
          661. was first introduced.

        * ‘PyFrame_LocalsToFast()’ no longer has any effect.  Calling
          this function is redundant now that *note PyFrame_GetLocals():
          661. returns a write-through proxy for *note optimized scopes:
          4a2.

   * Python 3.13 removed many private functions.  Some of them can be
     replaced using these alternatives:

        * ‘_PyDict_Pop()’: *note PyDict_Pop(): 422. or *note
          PyDict_PopString(): 5e5.;

        * ‘_PyDict_GetItemWithError()’: *note PyDict_GetItemRef(): 5e0.;

        * ‘_PyErr_WriteUnraisableMsg()’: *note PyErr_FormatUnraisable():
          5f1.;

        * ‘_PyEval_SetTrace()’: *note PyEval_SetTrace(): 663. or *note
          PyEval_SetTraceAllThreads(): 664.;

        * ‘_PyList_Extend()’: *note PyList_Extend(): 600.;

        * ‘_PyLong_AsInt()’: *note PyLong_AsInt(): 604.;

        * ‘_PyMem_RawStrdup()’: ‘strdup()’;

        * ‘_PyMem_Strdup()’: ‘strdup()’;

        * ‘_PyObject_ClearManagedDict()’: *note
          PyObject_ClearManagedDict(): 60e.;

        * ‘_PyObject_VisitManagedDict()’: *note
          PyObject_VisitManagedDict(): 60d.;

        * ‘_PyThreadState_UncheckedGet()’: *note
          PyThreadState_GetUnchecked(): 423.;

        * ‘_PyTime_AsSecondsDouble()’: *note PyTime_AsSecondsDouble():
          5d6.;

        * ‘_PyTime_GetMonotonicClock()’: *note PyTime_Monotonic(): 5d7.
          or *note PyTime_MonotonicRaw(): 5d8.;

        * ‘_PyTime_GetPerfCounter()’: *note PyTime_PerfCounter(): 5d9.
          or *note PyTime_PerfCounterRaw(): 5da.;

        * ‘_PyTime_GetSystemClock()’: *note PyTime_Time(): 5db. or *note
          PyTime_TimeRaw(): 5dc.;

        * ‘_PyTime_MAX’: *note PyTime_MAX: 5d5.;

        * ‘_PyTime_MIN’: *note PyTime_MIN: 5d4.;

        * ‘_PyTime_t’: *note PyTime_t: 5d3.;

        * ‘_Py_HashPointer()’: *note Py_HashPointer(): 425.;

        * ‘_Py_IsFinalizing()’: *note Py_IsFinalizing(): 5fd.

     The pythoncapi-compat project(6) can be used to get most of these
     new functions on Python 3.12 and older.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/108765

   (2) https://github.com/python/cpython/issues/108765

   (3) https://github.com/python/cpython/issues/108765

   (4) https://github.com/python/cpython/issues/85283

   (5) https://github.com/python/cpython/issues/105111

   (6) https://github.com/python/pythoncapi-compat/


File: python.info,  Node: Regression Test Changes,  Prev: Porting to Python 3 13,  Up: What’s New In Python 3 13

1.2.13 Regression Test Changes
------------------------------

   * Python built with ‘configure’ *note -with-pydebug: 666. now
     supports a *note -X presite=package.module: 16f. command-line
     option.  If used, it specifies a module that should be imported
     early in the lifecycle of the interpreter, before ‘site.py’ is
     executed.  (Contributed by Łukasz Langa in gh-110769(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/110769


File: python.info,  Node: Novità in Python 3 12,  Next: What’s New In Python 3 11,  Prev: What’s New In Python 3 13,  Up: Novità in Python

1.3 Novità in Python 3.12
=========================


Editor: Adam Turner

Questo articolo spiega le nuove funzionalità in Python 3.12, rispetto
alla versione 3.11.  Python 3.12 è stato rilasciato il 2 ottobre 2023.
Per i dettagli completi, consultare il *note changelog: 142.

Vedi anche
..........

PEP 693(1) – Programma di rilascio di Python 3.12

* Menu:

* Sommario – Punti salienti del rilascio::
* Nuove Funzionalità::
* Nuove funzionalità relative agli hint di tipo::
* Altre modifiche al Linguaggio::
* Nuovi Moduli::
* Moduli Migliorati::
* Ottimizzazioni::
* Modifiche al bytecode di CPython::
* Demos e Tools::
* Deprecato::
* Rimosso::
* Porting a Python 3.12: Porting a Python 3 12.
* Modifiche alla Build::
* Modifiche all’API C::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0693/


File: python.info,  Node: Sommario – Punti salienti del rilascio,  Next: Nuove Funzionalità,  Up: Novità in Python 3 12

1.3.1 Sommario – Punti salienti del rilascio
--------------------------------------------

Python 3.12 is a stable release of the Python programming language, with
a mix of changes to the language and the standard library.  The library
changes focus on cleaning up deprecated APIs, usability, and
correctness.  Of note, the ‘distutils’ package has been removed from the
standard library.  Filesystem support in *note os: a5. and *note
pathlib: a8. has seen a number of improvements, and several modules have
better performance.

Le modifiche al linguaggio si concentrano sull’usabilità, in quanto
molte limitazioni dei *note f-strings: 66b. sono state rimosse e i
suggerimenti “Intendevi dire …” continuano a migliorare.  La nuova *note
sintassi dei parametri di tipo: 66c. e l’istruzione *note type: 66d.
migliorano l’ergonomia per l’utilizzo di *note tipi generici: 1a1. e
*note alias di tipo: 66e. con i checker di tipo statico.

Questo articolo non tenta di fornire una specifica completa di tutte le
nuove funzionalità, ma offre invece una panoramica.  Per i dettagli
completi, dovresti fare riferimento alla documentazione, come il *note
Library Reference: 149. e il *note Language Reference: 14a.  Se vuoi
comprendere l’implementazione completa e la motivazione dietro una
modifica, fai riferimento al PEP per una particolare nuova funzionalità;
ma tieni presente che i PEP di solito non vengono aggiornati una volta
che una funzionalità è stata completamente implementata.

__________________________________________________________________

Nuove funzionalità sintattiche:

   * *note PEP 695: 66c, sintassi dei parametri di tipo e l’istruzione
     *note type: 66d.

Nuove funzionalità grammaticali:

   * *note PEP 701: 66f, *note f-strings: 66b. nella grammatica

Miglioramenti dell’interprete:

   * *note PEP 684: 670, un *note GIL: 474. univoco per interprete

   * *note PEP 669: 671, monitoraggio a basso impatto

   * *note Suggerimenti migliorati 'Intendevi dire ...': 672. per
     eccezioni *note NameError: 452, *note ImportError: 65b, e *note
     SyntaxError: 18e.

Miglioramenti al modello di dati di Python:

   * *note PEP 688: 673, usando il *note protocollo del buffer: 260. da
     Python

Miglioramenti significativi nella libreria standard:

   * La classe *note pathlib.Path: 266. ora supporta la
     sottoclassificazione

   * Il modulo *note os: a5. ha ricevuto diversi miglioramenti per il
     supporto di Windows

   * Un’interfaccia a riga di comando *note interface: 674. è stata
     aggiunta al modulo *note sqlite3: d4.

   * I controlli *note isinstance(): 2ad. contro i protocolli *note
     runtime-checkable: 675. godono di un’accelerazione tra due e 20
     volte

   * Il pacchetto *note asyncio: b. ha avuto numerosi miglioramenti di
     performance, con alcuni benchmark che mostrano un’accelerazione del
     75%.

   * Un’interfaccia a riga di comando *note interface: 676. è stata
     aggiunta al modulo *note uuid: 116.

   * A causa delle modifiche nel *note PEP 701: 66f, la produzione di
     token tramite il modulo *note tokenize: 101. è fino al 64% più
     veloce.

Miglioramenti alla sicurezza:

   * Sostituire le implementazioni integrate del modulo *note hashlib:
     6c. di SHA1, SHA3, SHA2-384, SHA2-512 e MD5 con codice formalmente
     verificato dal progetto HACL*(1).  Queste implementazioni integrate
     rimangono come fallback che vengono utilizzate solo quando OpenSSL
     non le fornisce.

Miglioramenti all’API C:

   * *note PEP 697: 677, livello instabile dell’API C

   * *note PEP 683: 678, oggetti immortali

Miglioramenti all’implementazione di CPython:

   * *note PEP 709: 679, inlining delle comprensioni

   * *note Supporto CPython: 4af. per il profiler ‘perf’ su Linux

   * Implementare la protezione da overflow dello stack su piattaforme
     supportate

Nuove funzionalità di typing:

   * *note PEP 692: 67a, utilizzo di *note TypedDict: 332. per annotare
     *note **kwargs: 67b.

   * *note PEP 698: 67c, decoratore *note typing.override(): 67d.

Deprecazioni, rimozioni o restrizioni importanti:

   * PEP 623(2): Rimuovere ‘wstr’ dagli oggetti Unicode nell’API C di
     Python, riducendo la dimensione di ogni oggetto *note str: 169. di
     almeno 8 byte.

   * PEP 632(3): Remove the ‘distutils’ package.  See the migration
     guide(4) for advice replacing the APIs it provided.  The
     third-party Setuptools(5) package continues to provide ‘distutils’,
     if you still require it in Python 3.12 and beyond.

   * gh-95299(6): Non preinstallare ‘setuptools’ negli ambienti virtuali
     creati con *note venv: 117.  Ciò significa che ‘distutils’,
     ‘setuptools’, ‘pkg_resources’ e ‘easy_install’ non saranno più
     disponibili di default; per accedervi eseguire ‘pip install
     setuptools’ nell’ambiente virtuale *note attivato: 67e.

   * I moduli ‘asynchat’, ‘asyncore’ e ‘imp’ sono stati rimossi, insieme
     a diversi *note alias di metodo: 67f. di *note unittest.TestCase:
     2b3.

   ---------- Footnotes ----------

   (1) https://github.com/hacl-star/hacl-star/

   (2) https://peps.python.org/pep-0623/

   (3) https://peps.python.org/pep-0632/

   (4) https://peps.python.org/pep-0632/#migration-advice

   (5) 
https://setuptools.pypa.io/en/latest/deprecated/distutils-legacy.html

   (6) https://github.com/python/cpython/issues/95299


File: python.info,  Node: Nuove Funzionalità,  Next: Nuove funzionalità relative agli hint di tipo,  Prev: Sommario – Punti salienti del rilascio,  Up: Novità in Python 3 12

1.3.2 Nuove Funzionalità
------------------------

* Menu:

* PEP 695; Sintassi dei Parametri di Tipo: PEP 695 Sintassi dei Parametri di Tipo.
* PEP 701; Formalizzazione sintattica delle f-string: PEP 701 Formalizzazione sintattica delle f-string.
* PEP 684; Un GIL per interprete: PEP 684 Un GIL per interprete.
* PEP 669; Monitoraggio a basso impatto per CPython: PEP 669 Monitoraggio a basso impatto per CPython.
* PEP 688; Rendere accessibile il protocollo buffer in Python: PEP 688 Rendere accessibile il protocollo buffer in Python.
* PEP 709; Inlining delle comprehension: PEP 709 Inlining delle comprehension.
* Messaggi di errore migliorati::


File: python.info,  Node: PEP 695 Sintassi dei Parametri di Tipo,  Next: PEP 701 Formalizzazione sintattica delle f-string,  Up: Nuove Funzionalità

1.3.2.1 PEP 695: Sintassi dei Parametri di Tipo
...............................................

Le classi generiche e le funzioni sotto PEP 484(1) erano dichiarate
utilizzando una sintassi verbosa che lasciava poco chiaro l’ambito dei
parametri di tipo e richiedeva dichiarazioni esplicite di varianza.

PEP 695(2) introduce un nuovo modo, più compatto ed esplicito, per
creare *note classi generiche: 682. e *note funzioni: 683.:

     def max[T](args: Iterable[T]) -> T:
         ...

     class list[T]:
         def __getitem__(self, index: int, /) -> T:
             ...

         def append(self, element: T) -> None:
             ...

Inoltre, il PEP introduce un nuovo modo di dichiarare *note alias di
tipo: 684. utilizzando l’istruzione *note type: 66d, che crea un’istanza
di *note TypeAliasType: 2ae.:

     type Point = tuple[float, float]

Gli alias di tipo possono anche essere *note generici: 685.:

     type Point[T] = tuple[T, T]

La nuova sintassi consente di dichiarare parametri *note TypeVarTuple:
489. e *note ParamSpec: 488, nonché parametri *note TypeVar: 487. con
limiti o vincoli:

     type IntFunc[**P] = Callable[P, int]  # ParamSpec
     type LabeledTuple[*Ts] = tuple[str, *Ts]  # TypeVarTuple
     type HashableSequence[T: Hashable] = Sequence[T]  # TypeVar with bound
     type IntOrStrSequence[T: (int, str)] = Sequence[T]  # TypeVar with constraints

Il valore degli alias di tipo e i limiti e vincoli delle variabili di
tipo creati con questa sintassi sono valutati solo su richiesta (vedi
*note lazy evaluation: 686.).  Ciò significa che gli alias di tipo
possono riferirsi ad altri tipi definiti successivamente nel file.

I parametri di tipo dichiarati attraverso una lista di parametri di tipo
sono visibili all’interno dell’ambito della dichiarazione e in qualsiasi
ambito annidato, ma non nell’ambito esterno.  Ad esempio, possono essere
utilizzati nelle annotazioni di tipo per i metodi di una classe generica
o nel corpo della classe.  Tuttavia, non possono essere utilizzati
nell’ambito del modulo dopo che la classe è stata definita.  Vedi *note
Type parameter lists: 5ad. per una descrizione dettagliata della
semantica di runtime dei parametri di tipo.

Per supportare questa semantica di ambito, è stato introdotto un nuovo
tipo di ambito, l”*note annotation scope: 4ac.  Gli ambiti di
annotazione si comportano per lo più come gli ambiti delle funzioni, ma
interagiscono in modo diverso con gli ambiti della classe che li
contengono.  In Python 3.13, le *note annotazioni: 15c. saranno valutate
negli ambiti di annotazione.

Vedi PEP 695(3) per ulteriori dettagli.

(PEP scritto da Eric Traut.  Implementazione di Jelle Zijlstra, Eric
Traut e altri in gh-103764(4).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0695/

   (3) https://peps.python.org/pep-0695/

   (4) https://github.com/python/cpython/issues/103764


File: python.info,  Node: PEP 701 Formalizzazione sintattica delle f-string,  Next: PEP 684 Un GIL per interprete,  Prev: PEP 695 Sintassi dei Parametri di Tipo,  Up: Nuove Funzionalità

1.3.2.2 PEP 701: Formalizzazione sintattica delle f-string
..........................................................

PEP 701(1) rimuove alcune restrizioni sull’uso delle *note f-string:
66b.  Gli elementi dell’espressione all’interno delle f-string possono
ora essere qualsiasi espressione Python valida, incluse stringhe che
riutilizzano la stessa virgoletta della f-string contenente, espressioni
multilinea, commenti, backslash e sequenze di escape unicode.
Approfondiamo questi aspetti in dettaglio:

   * Riutilizzo delle virgolette: in Python 3.11, riutilizzare le stesse
     virgolette della f-string contenente genera un’eccezione *note
     SyntaxError: 18e, costringendo l’utente a utilizzare altre
     virgolette disponibili (come l’uso delle virgolette doppie o delle
     virgolette triple se la f-string usa virgolette singole).  In
     Python 3.12, è ora possibile fare cose come questa:

          >>> songs = ['Take me back to Eden', 'Alkaline', 'Ascensionism']
          >>> f"This is the playlist: {", ".join(songs)}"
          'This is the playlist: Take me back to Eden, Alkaline, Ascensionism'

     Prima di questa modifica non esisteva un limite esplicito su come
     le f-string potessero essere annidate, ma il fatto che le
     virgolette delle stringhe non potessero essere riutilizzate
     all’interno dell’elemento di espressione delle f-string rendeva
     impossibile annidare le f-string arbitrariamente.  Infatti, questa
     è l’f-string più annidata che poteva essere scritta:

          >>> f"""{f'''{f'{f"{1+1}"}'}'''}"""
          '2'

     Poiché ora le f-string possono contenere qualsiasi espressione
     Python valida all’interno degli elementi di espressione, è ora
     possibile annidare le f-string arbitrariamente:

          >>> f"{f"{f"{f"{f"{f"{1+1}"}"}"}"}"}"
          '2'

   * Espressioni multilinea e commenti: in Python 3.11, le espressioni
     all’interno delle f-string devono essere definite in una singola
     riga, anche se l’espressione all’interno della f-string potrebbe
     normalmente estendersi su più righe (come le liste letterali
     definite su più righe), rendendole più difficili da leggere.  In
     Python 3.12 è ora possibile definire f-string che si estendono su
     più righe e aggiungere commenti in linea:

          >>> f"This is the playlist: {", ".join([
          ...     'Take me back to Eden',  # My, my, those eyes like fire
          ...     'Alkaline',              # Not acid nor alkaline
          ...     'Ascensionism'           # Take to the broken skies at last
          ... ])}"
          'This is the playlist: Take me back to Eden, Alkaline, Ascensionism'

   * Backslash e caratteri unicode: prima di Python 3.12, le espressioni
     f-string non potevano contenere alcun carattere ‘\’.  Questo
     influenzava anche le *note sequenze di escape: 688. unicode (come
     ‘\N{snowman}’) poiché contengono la parte ‘\N’ che prima non poteva
     far parte degli elementi di espressione delle f-string.  Ora puoi
     definire espressioni come questa:

          >>> print(f"This is the playlist: {"\n".join(songs)}")
          This is the playlist: Take me back to Eden
          Alkaline
          Ascensionism
          >>> print(f"This is the playlist: {"\N{BLACK HEART SUIT}".join(songs)}")
          This is the playlist: Take me back to Eden♥Alkaline♥Ascensionism

Vedi PEP 701(2) per ulteriori dettagli.

Come effetto collaterale positivo di come questa funzione è stata
implementata (parsing delle f-string con il PEG parser(3)), ora i
messaggi di errore per le f-string sono più precisi e includono l’esatta
posizione dell’errore.  Ad esempio, in Python 3.11, la seguente f-string
genera un’eccezione *note SyntaxError: 18e.:

     >>> my_string = f"{x z y}" + f"{1 + 1}"
       File "<stdin>", line 1
         (x z y)
          ^^^
     SyntaxError: f-string: invalid syntax. Perhaps you forgot a comma?

ma il messaggio di errore non include l’esatta posizione dell’errore
all’interno della riga e ha anche l’espressione circondata
artificialmente da parentesi.  In Python 3.12, poiché le f-string sono
parse con il PEG parser, i messaggi di errore possono essere più precisi
e mostrare l’intera riga:

     >>> my_string = f"{x z y}" + f"{1 + 1}"
       File "<stdin>", line 1
         my_string = f"{x z y}" + f"{1 + 1}"
                        ^^^
     SyntaxError: invalid syntax. Perhaps you forgot a comma?

(Contributi da Pablo Galindo, Batuhan Taskaya, Lysandros Nikolaou,
Cristián Maureira-Fredes e Marta Gómez in gh-102856(4).  PEP scritto da
Pablo Galindo, Batuhan Taskaya, Lysandros Nikolaou e Marta Gómez).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0701/

   (2) https://peps.python.org/pep-0701/

   (3) https://peps.python.org/pep-0617/

   (4) https://github.com/python/cpython/issues/102856


File: python.info,  Node: PEP 684 Un GIL per interprete,  Next: PEP 669 Monitoraggio a basso impatto per CPython,  Prev: PEP 701 Formalizzazione sintattica delle f-string,  Up: Nuove Funzionalità

1.3.2.3 PEP 684: Un GIL per interprete
......................................

PEP 684(1) introduce un *note GIL: 474. per interprete, in modo che gli
interpreti secondari possano ora essere creati con un GIL unico per
interprete.  Questo consente ai programmi Python di sfruttare appieno i
core della CPU multipli.  Attualmente è disponibile solo tramite la
C-API, sebbene si preveda una API Python per la versione 3.13(2).

Usa la nuova funzione *note Py_NewInterpreterFromConfig(): 68a. per
creare un interprete con il proprio GIL:

     PyInterpreterConfig config = {
         .check_multi_interp_extensions = 1,
         .gil = PyInterpreterConfig_OWN_GIL,
     };
     PyThreadState *tstate = NULL;
     PyStatus status = Py_NewInterpreterFromConfig(&tstate, &config);
     if (PyStatus_Exception(status)) {
         return -1;
     }
     /* The new interpreter is now active in the current thread. */

For further examples how to use the C-API for sub-interpreters with a
per-interpreter GIL, see ‘Modules/_xxsubinterpretersmodule.c’.

(Contributi da Eric Snow in gh-104210(3), ecc.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0684/

   (2) https://peps.python.org/pep-0554/

   (3) https://github.com/python/cpython/issues/104210


File: python.info,  Node: PEP 669 Monitoraggio a basso impatto per CPython,  Next: PEP 688 Rendere accessibile il protocollo buffer in Python,  Prev: PEP 684 Un GIL per interprete,  Up: Nuove Funzionalità

1.3.2.4 PEP 669: Monitoraggio a basso impatto per CPython
.........................................................

PEP 669(1) definisce una nuova *note API: e0. per profiler, debugger e
altri strumenti per monitorare eventi in CPython.  Copre una vasta gamma
di eventi, inclusi chiamate, ritorni, righe, eccezioni, salti e altro.
Questo significa che paghi solo per quello che usi, fornendo supporto
per strumenti di debug e copertura a quasi zero overhead.  Vedi *note
sys.monitoring: e0. per i dettagli.

(Contributi da Mark Shannon in gh-103082(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0669/

   (2) https://github.com/python/cpython/issues/103082


File: python.info,  Node: PEP 688 Rendere accessibile il protocollo buffer in Python,  Next: PEP 709 Inlining delle comprehension,  Prev: PEP 669 Monitoraggio a basso impatto per CPython,  Up: Nuove Funzionalità

1.3.2.5 PEP 688: Rendere accessibile il protocollo buffer in Python
...................................................................

PEP 688(1) introduce un modo per utilizzare il *note protocollo buffer:
260. dal codice Python.  Le classi che implementano il metodo *note
__buffer__(): 68d. sono ora utilizzabili come tipi di buffer.

Il nuovo ABC *note collections.abc.Buffer: 343. fornisce un modo
standard per rappresentare oggetti buffer, ad esempio nelle annotazioni
di tipo.  Il nuovo enumerativo *note inspect.BufferFlags: 68e.
rappresenta i flag che possono essere utilizzati per personalizzare la
creazione del buffer.  (Contributo di Jelle Zijlstra in gh-102500(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0688/

   (2) https://github.com/python/cpython/issues/102500


File: python.info,  Node: PEP 709 Inlining delle comprehension,  Next: Messaggi di errore migliorati,  Prev: PEP 688 Rendere accessibile il protocollo buffer in Python,  Up: Nuove Funzionalità

1.3.2.6 PEP 709: Inlining delle comprehension
.............................................

Le comprehension di dizionari, liste e set sono ora inlined, piuttosto
che creare un nuovo oggetto funzione monouso per ogni esecuzione della
comprehension.  Questo accelera l’esecuzione di una comprehension fino a
due volte.  Vedi PEP 709(1) per ulteriori dettagli.

Le variabili di iterazione delle comprehension rimangono isolate e non
sovrascrivono una variabile con lo stesso nome nell’ambito esterno, né
sono visibili dopo la comprehension.  L’inlining comporta alcuni
cambiamenti di comportamento visibili:

   * Nei traceback non c’è più un frame separato per la comprehension, e
     il tracciamento/profiling non mostra più la comprehension come una
     chiamata di funzione.

   * Il modulo *note symtable: de. non produrrà più tabelle simbolo
     figlie per ogni comprehension; invece, le variabili locali della
     comprehension saranno incluse nella tabella simbolo della funzione
     principale.

   * Chiamando *note locals(): 46f. all’interno di una comprehension ora
     include variabili dall’esterno della comprehension e non include
     più la variabile sintetica ‘.0’ per «l’argomento» della
     comprehension.

   * Una comprehension che itera direttamente su ‘locals()’ (ad es.  ‘[k
     for k in locals()]’) potrebbe vedere «RuntimeError: dimensione del
     dizionario cambiata durante l’iterazione» quando eseguita sotto
     tracciamento (ad es.  misurazione della copertura del codice).
     Questo è lo stesso comportamento già visto, ad es.  ‘for k in
     locals():’.  Per evitare l’errore, prima crea una lista di chiavi
     da iterare: ‘keys = list(locals()); [k for k in keys]’.

(Contributi di Carl Meyer e Vladimir Matveev in PEP 709(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0709/

   (2) https://peps.python.org/pep-0709/


File: python.info,  Node: Messaggi di errore migliorati,  Prev: PEP 709 Inlining delle comprehension,  Up: Nuove Funzionalità

1.3.2.7 Messaggi di errore migliorati
.....................................

   * I moduli della libreria standard sono ora potenzialmente suggeriti
     come parte dei messaggi di errore visualizzati dall’interprete
     quando un’eccezione *note NameError: 452. viene sollevata a livello
     superiore.  (Contributi da Pablo Galindo in gh-98254(1).)

          >>> sys.version_info
          Traceback (most recent call last):
            File "<stdin>", line 1, in <module>
          NameError: name 'sys' is not defined. Did you forget to import 'sys'?

   * Migliora il suggerimento di errore per le eccezioni *note
     NameError: 452. per le istanze.  Ora, se un’eccezione *note
     NameError: 452. viene sollevata in un metodo e l’istanza ha un
     attributo esattamente uguale al nome nell’eccezione, il
     suggerimento includerà ‘self.<NAME>’ invece della corrispondenza
     più vicina nell’ambito del metodo.  (Contributi da Pablo Galindo in
     gh-99139(2).)

          >>> class A:
          ...    def __init__(self):
          ...        self.blech = 1
          ...
          ...    def foo(self):
          ...        somethin = blech
          ...
          >>> A().foo()
          Traceback (most recent call last):
            File "<stdin>", line 1
              somethin = blech
                         ^^^^^
          NameError: name 'blech' is not defined. Did you mean: 'self.blech'?

   * Migliora il messaggio di errore *note SyntaxError: 18e. quando
     l’utente digita ‘import x from y’ invece di ‘from y import x’.
     (Contributi da Pablo Galindo in gh-98931(3).)

          >>> import a.y.z from b.y.z
          Traceback (most recent call last):
            File "<stdin>", line 1
              import a.y.z from b.y.z
              ^^^^^^^^^^^^^^^^^^^^^^^
          SyntaxError: Did you mean to use 'from ... import ...' instead?

   * Le eccezioni *note ImportError: 65b. sollevate da dichiarazioni di
     ‘from <module> import <name>’ fallite includono ora suggerimenti
     per il valore di ‘<name>’ basati sui nomi disponibili in
     ‘<module>’.  (Contributi da Pablo Galindo in gh-91058(4).)

          >>> from collections import chainmap
          Traceback (most recent call last):
            File "<stdin>", line 1, in <module>
          ImportError: cannot import name 'chainmap' from 'collections'. Did you mean: 'ChainMap'?

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98254

   (2) https://github.com/python/cpython/issues/99139

   (3) https://github.com/python/cpython/issues/98931

   (4) https://github.com/python/cpython/issues/91058


File: python.info,  Node: Nuove funzionalità relative agli hint di tipo,  Next: Altre modifiche al Linguaggio,  Prev: Nuove Funzionalità,  Up: Novità in Python 3 12

1.3.3 Nuove funzionalità relative agli hint di tipo
---------------------------------------------------

Questa sezione copre le principali modifiche che riguardano type
hints(1) e il modulo *note typing: 10a.

* Menu:

* PEP 692; Utilizzo di TypedDict per una digitazione **kwargs più precisa: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa.
* PEP 698; Decoratore Override per tipizzazione statica: PEP 698 Decoratore Override per tipizzazione statica.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/


File: python.info,  Node: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa,  Next: PEP 698 Decoratore Override per tipizzazione statica,  Up: Nuove funzionalità relative agli hint di tipo

1.3.3.1 PEP 692: Utilizzo di ‘TypedDict’ per una digitazione ‘**kwargs’ più precisa
...................................................................................

La digitazione di ‘**kwargs’ in una firma di funzione introdotta da PEP
484(1) consentiva annotazioni valide solo nei casi in cui tutti i
‘**kwargs’ erano dello stesso tipo.

PEP 692(2) specifica un modo più preciso di digitare ‘**kwargs’
affidandosi a dizionari tipizzati:

     from typing import TypedDict, Unpack

     class Movie(TypedDict):
       name: str
       year: int

     def foo(**kwargs: Unpack[Movie]): ...

Vedi PEP 692(3) per ulteriori dettagli.

(Contributo di Franek Magiera in gh-103629(4).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0692/

   (3) https://peps.python.org/pep-0692/

   (4) https://github.com/python/cpython/issues/103629


File: python.info,  Node: PEP 698 Decoratore Override per tipizzazione statica,  Prev: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa,  Up: Nuove funzionalità relative agli hint di tipo

1.3.3.2 PEP 698: Decoratore Override per tipizzazione statica
.............................................................

Un nuovo decoratore *note typing.override(): 67d. è stato aggiunto al
modulo *note typing: 10a.  Indica ai checker di tipo che il metodo è
destinato a sovrascrivere un metodo in una superclasse.  Questo consente
ai checker di tipo di rilevare errori in cui un metodo che dovrebbe
sovrascrivere qualcosa in una classe base in realtà non lo fa.

Esempio:

     from typing import override

     class Base:
       def get_color(self) -> str:
         return "blue"

     class GoodChild(Base):
       @override  # ok: overrides Base.get_color
       def get_color(self) -> str:
         return "yellow"

     class BadChild(Base):
       @override  # type checker error: does not override Base.get_color
       def get_colour(self) -> str:
         return "red"

Vedere PEP 698(1) per maggiori dettagli.

(Contributo di Steven Troxler in gh-101561(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0698/

   (2) https://github.com/python/cpython/issues/101561


File: python.info,  Node: Altre modifiche al Linguaggio,  Next: Nuovi Moduli,  Prev: Nuove funzionalità relative agli hint di tipo,  Up: Novità in Python 3 12

1.3.4 Altre modifiche al Linguaggio
-----------------------------------

   * Il parser ora solleva *note SyntaxError: 18e. quando analizza il
     codice sorgente contenente byte nulli.  (Contributo di Pablo
     Galindo in gh-96670(1).)

   * Una coppia carattere-barra rovesciata che non è una sequenza di
     escape valida ora genera un *note SyntaxWarning: 1ae, invece di un
     *note DeprecationWarning: 1a3.  Ad esempio,
     ‘re.compile("\d+\.\d+")’ ora emette un *note SyntaxWarning: 1ae.
     (‘"\d"’ è una sequenza di escape non valida, utilizzare stringhe
     raw per le espressioni regolari: ‘re.compile(r"\d+\.\d+")’).  In
     una futura versione di Python, verrà infine sollevato un *note
     SyntaxError: 18e, invece di un *note SyntaxWarning: 1ae.
     (Contributo di Victor Stinner in gh-98401(2).)

   * Le sequenze di escape ottali con valore maggiore di ‘0o377’ (es:
     ‘"\477"’), deprecate in Python 3.11, ora producono un *note
     SyntaxWarning: 1ae, invece di un *note DeprecationWarning: 1a3.  In
     una futura versione di Python, diventeranno infine un *note
     SyntaxError: 18e.  (Contributo di Victor Stinner in gh-98401(3).)

   * Le variabili utilizzate nella parte target delle comprensioni che
     non vengono memorizzate possono ora essere utilizzate nelle
     espressioni di assegnazione (‘:=’).  Ad esempio, in ‘[(b := 1) for
     a, b.prop in some_iter]’, l’assegnazione a ‘b’ è ora consentita.
     Si noti che l’assegnazione a variabili memorizzate nella parte
     target delle comprensioni (come ‘a’) è ancora vietata, come per PEP
     572(4).  (Contributo di Nikita Sobolev in gh-100581(5).)

   * Le eccezioni sollevate nel metodo ‘__set_name__’ di una classe o di
     un tipo non vengono più avvolte da un *note RuntimeError: 244.  Le
     informazioni di contesto vengono aggiunte all’eccezione come nota
     PEP 678(6).  (Contributo di Irit Katriel in gh-77757(7).)

   * Quando una costruzione ‘try-except*’ gestisce l’intero *note
     ExceptionGroup: 4d3. e solleva un’altra eccezione, quella eccezione
     non è più avvolta in un *note ExceptionGroup: 4d3.  Anche
     modificato nella versione 3.11.4.  (Contributo di Irit Katriel in
     gh-103590(8).)

   * Il Garbage Collector ora viene eseguito solo sul meccanismo eval
     breaker del ciclo di valutazione del bytecode Python invece delle
     allocazioni di oggetti.  Il GC può anche essere eseguito quando
     viene chiamato *note PyErr_CheckSignals(): 694. in modo che le
     estensioni C che devono essere eseguite per lungo tempo senza
     eseguire alcun codice Python abbiano anche la possibilità di
     eseguire periodicamente il GC. (Contributo di Pablo Galindo in
     gh-97922(9).)

   * Tutti i callable builtin e delle estensioni che si aspettano
     parametri booleani ora accettano argomenti di qualsiasi tipo invece
     di soli *note bool: 3c3. e *note int: 19b.  (Contributo di Serhiy
     Storchaka in gh-60203(10).)

   * *note memoryview: 165. supporta ora il tipo half-float (il codice
     di formato «e»).  (Contributo di Donghee Na e Antoine Pitrou in
     gh-90751(11).)

   * Gli oggetti *note slice: 695. sono ora hashabili, consentendo loro
     di essere utilizzati come chiavi di dizionari e elementi di
     insiemi.  (Contributo di Will Bradshaw, Furkan Onder e Raymond
     Hettinger in gh-101264(12).)

   * *note sum(): 696. utilizza ora la sommatoria Neumaier per
     migliorare la precisione e la commutatività quando si sommano float
     o mix di int e float.  (Contributo di Raymond Hettinger in
     gh-100425(13).)

   * *note ast.parse(): 1c2. solleva ora *note SyntaxError: 18e. invece
     di *note ValueError: 2ec. quando analizza il codice sorgente
     contenente byte nulli.  (Contributo di Pablo Galindo in
     gh-96670(14).)

   * I metodi di estrazione in *note tarfile: e4, e *note
     shutil.unpack_archive(): 697, hanno un nuovo argomento 'filter' che
     consente di limitare le funzionalità tar che possono essere
     sorprendenti o pericolose, come la creazione di file al di fuori
     della directory di destinazione.  Vedere *note tarfile extraction
     filters: 698. per ulteriori dettagli.  In Python 3.14, il valore
     predefinito passerà a ‘'data'’.  (Contributo di Petr Viktorin in
     PEP 706(15).)

   * Le istanze di *note types.MappingProxyType: 699. sono ora hashabili
     se la mappa sottostante è hashabile.  (Contributo di Serhiy
     Storchaka in gh-87995(16).)

   * Aggiungo *note supporto per il profiler perf: 4af. attraverso la
     nuova variabile di ambiente *note PYTHONPERFSUPPORT: 69a. e
     l’opzione da riga di comando *note -X perf: 16f, così come le nuove
     funzioni *note sys.activate_stack_trampoline(): 69b, *note
     sys.deactivate_stack_trampoline(): 69c. e *note
     sys.is_stack_trampoline_active(): 69d.  (Progettazione di Pablo
     Galindo.  Contributo di Pablo Galindo e Christian Heimes con
     contributi di Gregory P. Smith [Google] e Mark Shannon in
     gh-96123(17).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/96670

   (2) https://github.com/python/cpython/issues/98401

   (3) https://github.com/python/cpython/issues/98401

   (4) https://peps.python.org/pep-0572/

   (5) https://github.com/python/cpython/issues/100581

   (6) https://peps.python.org/pep-0678/

   (7) https://github.com/python/cpython/issues/77757

   (8) https://github.com/python/cpython/issues/103590

   (9) https://github.com/python/cpython/issues/97922

   (10) https://github.com/python/cpython/issues/60203

   (11) https://github.com/python/cpython/issues/90751

   (12) https://github.com/python/cpython/issues/101264

   (13) https://github.com/python/cpython/issues/100425

   (14) https://github.com/python/cpython/issues/96670

   (15) https://peps.python.org/pep-0706/

   (16) https://github.com/python/cpython/issues/87995

   (17) https://github.com/python/cpython/issues/96123


File: python.info,  Node: Nuovi Moduli,  Next: Moduli Migliorati,  Prev: Altre modifiche al Linguaggio,  Up: Novità in Python 3 12

1.3.5 Nuovi Moduli
------------------

   * Nessuno.


File: python.info,  Node: Moduli Migliorati,  Next: Ottimizzazioni,  Prev: Nuovi Moduli,  Up: Novità in Python 3 12

1.3.6 Moduli Migliorati
-----------------------

* Menu:

* array: array<2>.
* asyncio: asyncio<5>.
* calendar: calendar<2>.
* csv::
* dis: dis<3>.
* fractions: fractions<3>.
* importlib.resources: importlib resources.
* inspect: inspect<2>.
* itertools: itertools<3>.
* matematica::
* os: os<3>.
* os.path: os path<3>.
* pathlib: pathlib<6>.
* platform: platform<2>.
* pdb: pdb<4>.
* random: random<2>.
* shutil: shutil<2>.
* sqlite3: sqlite3<3>.
* statistica::
* sys: sys<3>.
* tempfile: tempfile<2>.
* threading: threading<2>.
* tkinter: tkinter<3>.
* tokenize::
* types: types<3>.
* typing: typing<4>.
* unicodedata: unicodedata<3>.
* unittest: unittest<3>.
* uuid: uuid<3>.


File: python.info,  Node: array<2>,  Next: asyncio<5>,  Up: Moduli Migliorati

1.3.6.1 array
.............

   * La classe *note array.array: 4bf. ora supporta il subscript,
     rendendola un *note generic type: 1a1.  (Contributo di Jelle
     Zijlstra in gh-98658(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98658


File: python.info,  Node: asyncio<5>,  Next: calendar<2>,  Prev: array<2>,  Up: Moduli Migliorati

1.3.6.2 asyncio
...............

   * Le prestazioni della scrittura sui socket in *note asyncio: b. sono
     state notevolmente migliorate.  ‘asyncio’ ora evita copie non
     necessarie durante la scrittura sui socket e utilizza *note
     sendmsg(): 6a2. se la piattaforma lo supporta.  (Contributo di
     Kumar Aditya in gh-91166(1).)

   * Aggiungo le funzioni *note asyncio.eager_task_factory(): 6a3. e
     *note asyncio.create_eager_task_factory(): 6a4. per permettere a un
     event loop di optare per l’esecuzione rapida dei task, rendendo
     alcuni casi d’uso 2x a 5x più veloci.  (Contributo di Jacob Bower &
     Itamar Oren in gh-102853(2), gh-104140(3) e gh-104138(4))

   * On Linux, *note asyncio: b. uses ‘asyncio.PidfdChildWatcher’ by
     default if *note os.pidfd_open(): 6a5. is available and functional
     instead of ‘asyncio.ThreadedChildWatcher’.  (Contributed by Kumar
     Aditya in gh-98024(5).)

   * The event loop now uses the best available child watcher for each
     platform (‘asyncio.PidfdChildWatcher’ if supported and
     ‘asyncio.ThreadedChildWatcher’ otherwise), so manually configuring
     a child watcher is not recommended.  (Contributed by Kumar Aditya
     in gh-94597(6).)

   * Aggiungo il parametro 'loop_factory' a *note asyncio.run(): 2f3.
     per consentire di specificare una factory per event loop
     personalizzata.  (Contributo di Kumar Aditya in gh-99388(7).)

   * Aggiungo l’implementazione in C di *note asyncio.current_task():
     6a6. per un miglioramento delle prestazioni da 4x a 6x.
     (Contributo di Itamar Oren e Pranav Thulasiram Bhat in
     gh-100344(8).)

   * *note asyncio.iscoroutine(): 6a7. ora restituisce ‘False’ per i
     generatori poiché *note asyncio: b. non supporta le coroutine
     basate su generatori legacy.  (Contributo di Kumar Aditya in
     gh-102748(9).)

   * *note asyncio.wait(): 6a8. e *note asyncio.as_completed(): 4c7.
     accettano ora generatori che generano task.  (Contributo di Kumar
     Aditya in gh-78530(10).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91166

   (2) https://github.com/python/cpython/issues/102853

   (3) https://github.com/python/cpython/issues/104140

   (4) https://github.com/python/cpython/issues/104138

   (5) https://github.com/python/cpython/issues/98024

   (6) https://github.com/python/cpython/issues/94597

   (7) https://github.com/python/cpython/issues/99388

   (8) https://github.com/python/cpython/issues/100344

   (9) https://github.com/python/cpython/issues/102748

   (10) https://github.com/python/cpython/issues/78530


File: python.info,  Node: calendar<2>,  Next: csv,  Prev: asyncio<5>,  Up: Moduli Migliorati

1.3.6.3 calendar
................

   * Aggiungo gli enum *note calendar.Month: 6aa. e *note calendar.Day:
     6ab. che definiscono i mesi dell’anno e i giorni della settimana.
     (Contributo di Prince Roshan in gh-103636(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/103636


File: python.info,  Node: csv,  Next: dis<3>,  Prev: calendar<2>,  Up: Moduli Migliorati

1.3.6.4 csv
...........

   * Add *note csv.QUOTE_NOTNULL: 6ad. and *note csv.QUOTE_STRINGS: 6ae.
     flags to provide finer grained control of ‘None’ and empty strings
     by *note reader: 6af. and *note writer: 6b0. objects.


File: python.info,  Node: dis<3>,  Next: fractions<3>,  Prev: csv,  Up: Moduli Migliorati

1.3.6.5 dis
...........

   * Gli opcode delle pseudo-istruzioni (che sono utilizzati dal
     compilatore ma non compaiono nel bytecode eseguibile) sono ora
     esposti nel modulo *note dis: 3c.  *note HAVE_ARGUMENT: 6b2. è
     ancora rilevante per i reali opcode, ma non è utile per le
     pseudo-istruzioni.  Usare la nuova collezione *note dis.hasarg:
     59f. al suo posto.  (Contributo di Irit Katriel in gh-94216(1).)

   * Aggiungo la collezione *note dis.hasexc: 6b3. per indicare le
     istruzioni che impostano un gestore di eccezioni.  (Contributo di
     Irit Katriel in gh-94216(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94216

   (2) https://github.com/python/cpython/issues/94216


File: python.info,  Node: fractions<3>,  Next: importlib resources,  Prev: dis<3>,  Up: Moduli Migliorati

1.3.6.6 fractions
.................

   * Gli oggetti di tipo *note fractions.Fraction: 213. ora supportano
     il formato float-style.  (Contributo di Mark Dickinson in
     gh-100161(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100161


File: python.info,  Node: importlib resources,  Next: inspect<2>,  Prev: fractions<3>,  Up: Moduli Migliorati

1.3.6.7 importlib.resources
...........................

   * *note importlib.resources.as_file(): 6b6. supporta ora le directory
     di risorse.  (Contributo di Jason R. Coombs in gh-97930(1).)

   * Rinominare il primo parametro di *note importlib.resources.files():
     6b7. in 'anchor'.  (Contributo di Jason R. Coombs in gh-100598(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97930

   (2) https://github.com/python/cpython/issues/100598


File: python.info,  Node: inspect<2>,  Next: itertools<3>,  Prev: importlib resources,  Up: Moduli Migliorati

1.3.6.8 inspect
...............

   * Aggiungo *note inspect.markcoroutinefunction(): 6b9. per
     contrassegnare le funzioni sync che restituiscono una *note
     coroutine: 6ba. per l’uso con *note inspect.iscoroutinefunction():
     30d.  (Contributo di Carlton Gibson in gh-99247(1).)

   * Aggiungo *note inspect.getasyncgenstate(): 6bb. e *note
     inspect.getasyncgenlocals(): 6bc. per determinare lo stato corrente
     dei generatori asincroni.  (Contributo di Thomas Krennwallner in
     gh-79940(2).)

   * Le prestazioni di *note inspect.getattr_static(): 6bd. sono state
     notevolmente migliorate.  La maggior parte delle chiamate a questa
     funzione dovrebbe essere almeno 2x più veloce rispetto a Python
     3.11.  (Contributo di Alex Waygood in gh-103193(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99247

   (2) https://github.com/python/cpython/issues/79940

   (3) https://github.com/python/cpython/issues/103193


File: python.info,  Node: itertools<3>,  Next: matematica,  Prev: inspect<2>,  Up: Moduli Migliorati

1.3.6.9 itertools
.................

   * Add *note itertools.batched(): 512. for collecting into even-sized
     tuples where the last batch may be shorter than the rest.
     (Contributed by Raymond Hettinger in gh-98363(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98363


File: python.info,  Node: matematica,  Next: os<3>,  Prev: itertools<3>,  Up: Moduli Migliorati

1.3.6.10 matematica
...................

   * Aggiungi *note math.sumprod(): 6c0. per calcolare una somma di
     prodotti.  (Contribuito da Raymond Hettinger in gh-100485(1).)

   * Estendere *note math.nextafter(): 6c1. per includere un argomento
     'steps' per muoversi su o giù di più passi alla volta.
     (Contribuito da Matthias Goergens, Mark Dickinson, e Raymond
     Hettinger in gh-94906(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100485

   (2) https://github.com/python/cpython/issues/94906


File: python.info,  Node: os<3>,  Next: os path<3>,  Prev: matematica,  Up: Moduli Migliorati

1.3.6.11 os
...........

   * Aggiungi *note os.PIDFD_NONBLOCK: 6c3. per aprire un file
     descriptor per un processo con *note os.pidfd_open(): 6a5. in
     modalità non bloccante.  (Contribuito da Kumar Aditya in
     gh-93312(1).)

   * *note os.DirEntry: 6c4. ora include un metodo *note
     os.DirEntry.is_junction(): 6c5. per verificare se l’elemento è una
     giunzione.  (Contribuito da Charles Machalow in gh-99547(2).)

   * Aggiungi le funzioni *note os.listdrives(): 6c6, *note
     os.listvolumes(): 6c7. e *note os.listmounts(): 6c8. su Windows per
     enumerare unità, volumi e punti di montaggio.  (Contribuito da
     Steve Dower in gh-102519(3).)

   * Le funzioni *note os.stat(): 26d. e *note os.lstat(): 6c9. sono ora
     più precise su Windows.  Il campo ‘st_birthtime’ verrà ora riempito
     con il tempo di creazione del file e ‘st_ctime’ è deprecato ma
     contiene ancora il tempo di creazione (ma in futuro restituirà
     l’ultima modifica ai metadati, per coerenza con altre piattaforme).
     ‘st_dev’ può essere fino a 64 bit e ‘st_ino’ fino a 128 bit a
     seconda del file system, e ‘st_rdev’ è sempre impostato su zero
     anziché valori errati.  Entrambe le funzioni possono essere
     significativamente più veloci nelle nuove versioni di Windows.
     (Contribuito da Steve Dower in gh-99726(4).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/93312

   (2) https://github.com/python/cpython/issues/99547

   (3) https://github.com/python/cpython/issues/102519

   (4) https://github.com/python/cpython/issues/99726


File: python.info,  Node: os path<3>,  Next: pathlib<6>,  Prev: os<3>,  Up: Moduli Migliorati

1.3.6.12 os.path
................

   * Aggiungi *note os.path.isjunction(): 6cb. per verificare se un
     determinato percorso è una giunzione.  (Contribuito da Charles
     Machalow in gh-99547(1).)

   * Aggiungi *note os.path.splitroot(): 6cc. per dividere un percorso
     in una triade ‘(drive, root, tail)’.  (Contribuito da Barney Gale
     in gh-101000(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99547

   (2) https://github.com/python/cpython/issues/101000


File: python.info,  Node: pathlib<6>,  Next: platform<2>,  Prev: os path<3>,  Up: Moduli Migliorati

1.3.6.13 pathlib
................

   * Aggiungi il supporto per la sottoclassificazione di *note
     pathlib.PurePath: 6ce. e *note pathlib.Path: 266, oltre alle loro
     varianti specifiche Posix e Windows.  Le sottoclassi possono
     sovrascrivere il metodo *note pathlib.PurePath.with_segments():
     6cf. per passare informazioni tra le istanze del cammino.

   * Aggiungi *note pathlib.Path.walk(): 6d0. per attraversare gli
     alberi delle directory e generare tutti i nomi di file o directory
     al loro interno, simile a *note os.walk(): 6d1.  (Contribuito da
     Stanislav Zmiev in gh-90385(1).)

   * Aggiungi il parametro opzionale 'walk_up' a *note
     pathlib.PurePath.relative_to(): 2fd. per permettere l’inserimento
     di voci ‘..’ nel risultato; questo comportamento è più coerente con
     *note os.path.relpath(): 6d2.  (Contribuito da Domenico Ragusa in
     gh-84538(2).)

   * Aggiungi *note pathlib.Path.is_junction(): 6d3. come proxy per
     *note os.path.isjunction(): 6cb.  (Contribuito da Charles Machalow
     in gh-99547(3).)

   * Aggiungi il parametro opzionale 'case_sensitive' a *note
     pathlib.Path.glob(): 538, *note pathlib.Path.rglob(): 539. e *note
     pathlib.PurePath.match(): 6d4. per abbinare la sensibilità del
     percorso, consentendo un controllo più preciso sul processo di
     abbinamento.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/90385

   (2) https://github.com/python/cpython/issues/84538

   (3) https://github.com/python/cpython/issues/99547


File: python.info,  Node: platform<2>,  Next: pdb<4>,  Prev: pathlib<6>,  Up: Moduli Migliorati

1.3.6.14 platform
.................

   * Add support for detecting Windows 11 and Windows Server releases
     past 2012.  Previously, lookups on Windows Server platforms newer
     than Windows Server 2012 and on Windows 11 would return
     ‘Windows-10’.  (Contributed by Steve Dower in gh-89545(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89545


File: python.info,  Node: pdb<4>,  Next: random<2>,  Prev: platform<2>,  Up: Moduli Migliorati

1.3.6.15 pdb
............

   * Aggiungi variabili di convenienza per tenere temporaneamente i
     valori per la sessione di debug e fornire un accesso rapido a
     valori come il frame corrente o il valore di ritorno.  (Contribuito
     da Tian Gao in gh-103693(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/103693


File: python.info,  Node: random<2>,  Next: shutil<2>,  Prev: pdb<4>,  Up: Moduli Migliorati

1.3.6.16 random
...............

   * Aggiungi *note random.binomialvariate(): 6d8.  (Contribuito da
     Raymond Hettinger in gh-81620(1).)

   * Aggiungi un default di ‘lambd=1.0’ a *note random.expovariate():
     6d9.  (Contribuito da Raymond Hettinger in gh-100234(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/81620

   (2) https://github.com/python/cpython/issues/100234


File: python.info,  Node: shutil<2>,  Next: sqlite3<3>,  Prev: random<2>,  Up: Moduli Migliorati

1.3.6.17 shutil
...............

   * *note shutil.make_archive(): 6db. ora passa l’argomento 'root_dir'
     agli archiviatori personalizzati che lo supportano.  In questo
     caso, non cambia più temporaneamente la directory di lavoro
     corrente del processo in 'root_dir' per eseguire l’archiviazione.
     (Contribuito da Serhiy Storchaka in gh-74696(1).)

   * *note shutil.rmtree(): 356. ora accetta un nuovo argomento 'onexc'
     che è un gestore di errori simile a 'onerror' ma che si aspetta
     un’istanza di eccezione piuttosto che un terzetto '(typ, val, tb)'.
     'onerror' è deprecato.  (Contribuito da Irit Katriel in
     gh-102828(2).)

   * *note shutil.which(): 6dc. ora consulta la variabile d’ambiente
     'PATHEXT' per trovare corrispondenze all’interno di 'PATH' su
     Windows anche quando il 'cmd' dato include un componente di
     directory.  (Contribuito da Charles Machalow in gh-103179(3).)

     *note shutil.which(): 6dc. chiamerà
     ‘NeedCurrentDirectoryForExePathW’ quando interroga per eseguibili
     su Windows per determinare se la directory di lavoro corrente
     dovrebbe essere aggiunta al percorso di ricerca.  (Contribuito da
     Charles Machalow in gh-103179(4).)

     *note shutil.which(): 6dc. restituirà un percorso corrispondente al
     'cmd' con un componente da ‘PATHEXT’ prima di una corrispondenza
     diretta altrove nel percorso di ricerca su Windows.  (Contribuito
     da Charles Machalow in gh-103179(5).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/74696

   (2) https://github.com/python/cpython/issues/102828

   (3) https://github.com/python/cpython/issues/103179

   (4) https://github.com/python/cpython/issues/103179

   (5) https://github.com/python/cpython/issues/103179


File: python.info,  Node: sqlite3<3>,  Next: statistica,  Prev: shutil<2>,  Up: Moduli Migliorati

1.3.6.18 sqlite3
................

   * Aggiungi una *note interfaccia da linea di comando: 674.
     (Contribuito da Erlend E. Aasland in gh-77617(1).)

   * Aggiungi l’attributo *note sqlite3.Connection.autocommit: 6de. a
     *note sqlite3.Connection: 54e. e il parametro 'autocommit' a *note
     sqlite3.connect(): 5a6. per controllare la PEP 249(2)-compliant
     *note gestione delle transazioni: 6df.  (Contribuito da Erlend E.
     Aasland in gh-83638(3).)

   * Aggiungi il parametro keyword-only 'entrypoint' a *note
     sqlite3.Connection.load_extension(): 6e0, per sovrascrivere il
     punto di ingresso dell’estensione SQLite.  (Contribuito da Erlend
     E.  Aasland in gh-103015(4).)

   * Aggiungi *note sqlite3.Connection.getconfig(): 6e1. e *note
     sqlite3.Connection.setconfig(): 6e2. a *note sqlite3.Connection:
     54e. per apportare modifiche di configurazione a una connessione al
     database.  (Contribuito da Erlend E. Aasland in gh-103489(5).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/77617

   (2) https://peps.python.org/pep-0249/

   (3) https://github.com/python/cpython/issues/83638

   (4) https://github.com/python/cpython/issues/103015

   (5) https://github.com/python/cpython/issues/103489


File: python.info,  Node: statistica,  Next: sys<3>,  Prev: sqlite3<3>,  Up: Moduli Migliorati

1.3.6.19 statistica
...................

   * Estendere *note statistics.correlation(): 6e4. per includere un
     metodo ‘ranked’ per calcolare la correlazione di Spearman di dati
     classificati.  (Contribuito da Raymond Hettinger in gh-95861(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/95861


File: python.info,  Node: sys<3>,  Next: tempfile<2>,  Prev: statistica,  Up: Moduli Migliorati

1.3.6.20 sys
............

   * Aggiungi lo spazio dei nomi *note sys.monitoring: e0. per esporre
     la nuova API di monitoraggio *note PEP 669: 671.  (Contribuito da
     Mark Shannon in gh-103082(1).)

   * Aggiungi *note sys.activate_stack_trampoline(): 69b. e *note
     sys.deactivate_stack_trampoline(): 69c. per attivare e disattivare
     i trampolini del profiler di stack, e *note
     sys.is_stack_trampoline_active(): 69d. per verificare se i
     trampolini del profiler di stack sono attivi.  (Contribuito da
     Pablo Galindo e Christian Heimes con contributi di Gregory P. Smith
     [Google] e Mark Shannon in gh-96123(2).)

   * Aggiungi *note sys.last_exc: 6e6. che contiene l’ultima eccezione
     non gestita che è stata sollevata (per casi d’uso di debug
     post-mortem).  Deprecati i tre campi che contengono le stesse
     informazioni nella loro forma legacy: *note sys.last_type: 6e7,
     *note sys.last_value: 6e8. e *note sys.last_traceback: 6e9.
     (Contribuito da Irit Katriel in gh-102778(3).)

   * *note sys._current_exceptions(): 6ea. ora restituisce una mappa da
     thread-id a un’istanza di eccezione, anziché a una tupla ‘(typ,
     exc, tb)’.  (Contribuito da Irit Katriel in gh-103176(4).)

   * *note sys.setrecursionlimit(): 6eb. e *note
     sys.getrecursionlimit(): 6ec.  Il limite di ricorsione ora si
     applica solo al codice Python.  Le funzioni built-in non utilizzano
     il limite di ricorsione, ma sono protette da un diverso meccanismo
     che impedisce alla ricorsione di causare il crash della macchina
     virtuale.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/103082

   (2) https://github.com/python/cpython/issues/96123

   (3) https://github.com/python/cpython/issues/102778

   (4) https://github.com/python/cpython/issues/103176


File: python.info,  Node: tempfile<2>,  Next: threading<2>,  Prev: sys<3>,  Up: Moduli Migliorati

1.3.6.21 tempfile
.................

   * La funzione *note tempfile.NamedTemporaryFile: 6ee. ha un nuovo
     parametro opzionale 'delete_on_close' (Contribuito da Evgeny Zorin
     in gh-58451(1).)

   * *note tempfile.mkdtemp(): 52e. ora ritorna sempre un percorso
     assoluto, anche se l’argomento fornito al parametro 'dir' è un
     percorso relativo.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/58451


File: python.info,  Node: threading<2>,  Next: tkinter<3>,  Prev: tempfile<2>,  Up: Moduli Migliorati

1.3.6.22 threading
..................

   * Aggiungi *note threading.settrace_all_threads(): 6f0. e *note
     threading.setprofile_all_threads(): 6f1. che permettono di
     impostare funzioni di traccia e di profilazione in tutti i thread
     in esecuzione oltre a quello chiamante.  (Contribuito da Pablo
     Galindo in gh-93503(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/93503


File: python.info,  Node: tkinter<3>,  Next: tokenize,  Prev: threading<2>,  Up: Moduli Migliorati

1.3.6.23 tkinter
................

   * ‘tkinter.Canvas.coords()’ ora appiattisce i suoi argomenti.  Ora
     accetta non solo coordinate come argomenti separati (‘x1, y1, x2,
     y2, ...’) e una sequenza di coordinate (‘[x1, y1, x2, y2, ...]’),
     ma anche coordinate raggruppate in coppie (‘(x1, y1), (x2, y2),
     ...’ e ‘[(x1, y1), (x2, y2), ...]’), come i metodi ‘create_*()’.
     (Contributo di Serhiy Storchaka in gh-94473(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94473


File: python.info,  Node: tokenize,  Next: types<3>,  Prev: tkinter<3>,  Up: Moduli Migliorati

1.3.6.24 tokenize
.................

   * Il modulo *note tokenize: 101. include le modifiche introdotte in
     PEP 701(1).  (Contributo di Marta Gómez Macías e Pablo Galindo in
     gh-102856(2).)  Vedi *note Porting a Python 3.12: 6f4. per maggiori
     informazioni sulle modifiche al modulo *note tokenize: 101.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0701/

   (2) https://github.com/python/cpython/issues/102856


File: python.info,  Node: types<3>,  Next: typing<4>,  Prev: tokenize,  Up: Moduli Migliorati

1.3.6.25 types
..............

   * Aggiungi *note types.get_original_bases(): 6f6. per consentire
     ulteriori introspezioni dei *note User-defined generic types: 6f7.
     quando sottoclassati.  (Contributo di James Hilton-Balfe e Alex
     Waygood in gh-101827(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101827


File: python.info,  Node: typing<4>,  Next: unicodedata<3>,  Prev: types<3>,  Up: Moduli Migliorati

1.3.6.26 typing
...............

   * I controlli *note isinstance(): 2ad. contro i *note
     runtime-checkable protocols: 675. ora utilizzano *note
     inspect.getattr_static(): 6bd. anziché *note hasattr(): 6fa. per
     verificare l’esistenza degli attributi.  Ciò significa che i
     descrittori e i metodi *note __getattr__(): 6fb. non vengono più
     valutati inaspettatamente durante i controlli ‘isinstance()’ contro
     i protocolli verificabili a runtime.  Tuttavia, ciò può anche
     significare che alcuni oggetti che in precedenza erano considerati
     istanze di un protocollo verificabile a runtime potrebbero non
     essere più considerati tali con Python 3.12+ e viceversa.  La
     maggior parte degli utenti non dovrebbe essere influenzata da
     questo cambiamento.  (Contributo di Alex Waygood in gh-102433(1).)

   * I membri di un protocollo verificabile a runtime sono ora
     considerati «congelati» a runtime non appena la classe è stata
     creata.  Il monkey-patching degli attributi in un protocollo
     verificabile a runtime funzionerà ancora, ma non avrà alcun impatto
     sui controlli *note isinstance(): 2ad. che confrontano oggetti con
     il protocollo.  Per esempio:

          >>> from typing import Protocol, runtime_checkable
          >>> @runtime_checkable
          ... class HasX(Protocol):
          ...     x = 1
          ...
          >>> class Foo: ...
          ...
          >>> f = Foo()
          >>> isinstance(f, HasX)
          False
          >>> f.x = 1
          >>> isinstance(f, HasX)
          True
          >>> HasX.y = 2
          >>> isinstance(f, HasX)  # unchanged, even though HasX now also has a "y" attribute
          True

     Questa modifica è stata apportata per velocizzare i controlli
     ‘isinstance()’ contro i protocolli verificabili a runtime.

   * Il profilo delle prestazioni dei controlli *note isinstance(): 2ad.
     contro i *note runtime-checkable protocols: 675. è cambiato
     significativamente.  La maggior parte dei controlli ‘isinstance()’
     contro i protocolli con pochi membri dovrebbe essere almeno 2 volte
     più veloce rispetto alla versione 3.11, e alcuni potrebbero essere
     20 volte più veloci o più.  Tuttavia, i controlli ‘isinstance()’
     contro i protocolli con molti membri potrebbero risultare più lenti
     rispetto a Python 3.11.  (Contributo di Alex Waygood in gh-74690(2)
     e gh-103193(3).)

   * Tutte le classi *note typing.TypedDict: 332. e *note
     typing.NamedTuple: 331. ora possiedono l’attributo
     ‘__orig_bases__’.  (Contributo di Adrian Garcia Badaracco in
     gh-103699(4).)

   * Aggiungi il parametro ‘frozen_default’ a *note
     typing.dataclass_transform(): 6fc.  (Contributo di Erik De Bonte in
     gh-99957(5).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102433

   (2) https://github.com/python/cpython/issues/74690

   (3) https://github.com/python/cpython/issues/103193

   (4) https://github.com/python/cpython/issues/103699

   (5) https://github.com/python/cpython/issues/99957


File: python.info,  Node: unicodedata<3>,  Next: unittest<3>,  Prev: typing<4>,  Up: Moduli Migliorati

1.3.6.27 unicodedata
....................

   * Il database Unicode è stato aggiornato alla versione 15.0.0.
     (Contributo di Benjamin Peterson in gh-96734(1)).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/96734


File: python.info,  Node: unittest<3>,  Next: uuid<3>,  Prev: unicodedata<3>,  Up: Moduli Migliorati

1.3.6.28 unittest
.................

Aggiungi l’opzione di linea di comando ‘--durations’, che mostra i N
casi di test più lenti:

     python3 -m unittest --durations=3 lib.tests.test_threading
     .....
     Slowest test durations
     ----------------------------------------------------------------------
     1.210s     test_timeout (Lib.test.test_threading.BarrierTests)
     1.003s     test_default_timeout (Lib.test.test_threading.BarrierTests)
     0.518s     test_timeout (Lib.test.test_threading.EventTests)

     (0.000 durations hidden.  Use -v to show these durations.)
     ----------------------------------------------------------------------
     Ran 158 tests in 9.869s

     OK (skipped=3)

(Contributo di Giampaolo Rodola in gh-48330(1))

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/48330


File: python.info,  Node: uuid<3>,  Prev: unittest<3>,  Up: Moduli Migliorati

1.3.6.29 uuid
.............

   * Aggiungi una *note interfaccia della linea di comando: 676.
     (Contributo di Adam Chhina in gh-88597(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/88597


File: python.info,  Node: Ottimizzazioni,  Next: Modifiche al bytecode di CPython,  Prev: Moduli Migliorati,  Up: Novità in Python 3 12

1.3.7 Ottimizzazioni
--------------------

   * Rimuovi i membri ‘wstr’ e ‘wstr_length’ dagli oggetti Unicode.  Ciò
     riduce la dimensione degli oggetti di 8 o 16 byte sulla piattaforma
     a 64 bit.  ( PEP 623(1)) (Contributo di Inada Naoki in
     gh-92536(2).)

   * Aggiungi il supporto sperimentale per l’uso dell’ottimizzatore
     binario BOLT nel processo di build, che migliora le prestazioni
     dell’1-5%.  (Contributo di Kevin Modzelewski in gh-90536(3) e
     ottimizzato da Donghee Na in gh-101525(4))

   * Velocizza la sostituzione delle espressioni regolari (funzioni
     *note re.sub(): 5a3. e *note re.subn(): 5a4. e i corrispondenti
     metodi di ‘re.Pattern’) per le stringhe di sostituzione contenenti
     riferimenti di gruppo di 2-3 volte.  (Contributo di Serhiy
     Storchaka in gh-91524(5).)

   * Velocizza la creazione di *note asyncio.Task: 1c7. rimandando la
     formattazione delle stringhe costosa.  (Contributo di Itamar Oren
     in gh-103793(6).)

   * Le funzioni *note tokenize.tokenize(): 701. e *note
     tokenize.generate_tokens(): 702. sono fino al 64% più veloci come
     effetto collaterale delle modifiche necessarie per coprire PEP
     701(7) nel modulo *note tokenize: 101.  (Contributo di Marta Gómez
     Macías e Pablo Galindo in gh-102856(8).)

   * Velocizza le chiamate al metodo *note super(): 1a6. e i caricamenti
     degli attributi tramite la nuova istruzione *note LOAD_SUPER_ATTR:
     703.  (Contributo di Carl Meyer e Vladimir Matveev in
     gh-103497(9).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0623/

   (2) https://github.com/python/cpython/issues/92536

   (3) https://github.com/python/cpython/issues/90536

   (4) https://github.com/python/cpython/issues/101525

   (5) https://github.com/python/cpython/issues/91524

   (6) https://github.com/python/cpython/issues/103793

   (7) https://peps.python.org/pep-0701/

   (8) https://github.com/python/cpython/issues/102856

   (9) https://github.com/python/cpython/issues/103497


File: python.info,  Node: Modifiche al bytecode di CPython,  Next: Demos e Tools,  Prev: Ottimizzazioni,  Up: Novità in Python 3 12

1.3.8 Modifiche al bytecode di CPython
--------------------------------------

   * Rimuovi l’istruzione ‘LOAD_METHOD’.  È stata unita a *note
     LOAD_ATTR: 705.  Ora *note LOAD_ATTR: 705. si comporterà come la
     vecchia istruzione ‘LOAD_METHOD’ se il bit inferiore del suo oparg
     è impostato.  (Contributo di Ken Jin in gh-93429(1).)

   * Rimuovi le istruzioni ‘JUMP_IF_FALSE_OR_POP’ e
     ‘JUMP_IF_TRUE_OR_POP’.  (Contributo di Irit Katriel in
     gh-102859(2).)

   * Rimuovi l’istruzione ‘PRECALL’.  (Contributo di Mark Shannon in
     gh-92925(3).)

   * Aggiungi le istruzioni *note BINARY_SLICE: 706. e *note
     STORE_SLICE: 707.  (Contributo di Mark Shannon in gh-94163(4).)

   * Aggiungi le istruzioni *note CALL_INTRINSIC_1: 708.  (Contributo di
     Mark Shannon in gh-99005(5).)

   * Aggiungi l’istruzione *note CALL_INTRINSIC_2: 709.  (Contributo di
     Irit Katriel in gh-101799(6).)

   * Aggiungi l’istruzione *note CLEANUP_THROW: 70a.  (Contributo di
     Brandt Bucher in gh-90997(7).)

   * Aggiungi l’istruzione ‘END_SEND’.  (Contributo di Mark Shannon in
     gh-103082(8).)

   * Aggiungi l’istruzione *note LOAD_FAST_AND_CLEAR: 70b. come parte
     dell’implementazione di PEP 709(9).  (Contributo di Carl Meyer in
     gh-101441(10).)

   * Aggiungi l’istruzione *note LOAD_FAST_CHECK: 70c.  (Contributo di
     Dennis Sweeney in gh-93143(11).)

   * Aggiungi le istruzioni *note LOAD_FROM_DICT_OR_DEREF: 70d, *note
     LOAD_FROM_DICT_OR_GLOBALS: 70e, e *note LOAD_LOCALS: 70f. come
     parte dell’implementazione di PEP 695(12).  Rimuovi l’opcode
     ‘LOAD_CLASSDEREF’, che può essere sostituito con *note LOAD_LOCALS:
     70f. più *note LOAD_FROM_DICT_OR_DEREF: 70d.  (Contributo di Jelle
     Zijlstra in gh-103764(13).)

   * Aggiungi l’istruzione *note LOAD_SUPER_ATTR: 703.  (Contributo di
     Carl Meyer e Vladimir Matveev in gh-103497(14).)

   * Add the ‘RETURN_CONST’ instruction.  (Contributed by Wenyang Wang
     in gh-101632(15).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/93429

   (2) https://github.com/python/cpython/issues/102859

   (3) https://github.com/python/cpython/issues/92925

   (4) https://github.com/python/cpython/issues/94163

   (5) https://github.com/python/cpython/issues/99005

   (6) https://github.com/python/cpython/issues/101799

   (7) https://github.com/python/cpython/issues/90997

   (8) https://github.com/python/cpython/issues/103082

   (9) https://peps.python.org/pep-0709/

   (10) https://github.com/python/cpython/issues/101441

   (11) https://github.com/python/cpython/issues/93143

   (12) https://peps.python.org/pep-0695/

   (13) https://github.com/python/cpython/issues/103764

   (14) https://github.com/python/cpython/issues/103497

   (15) https://github.com/python/cpython/issues/101632


File: python.info,  Node: Demos e Tools,  Next: Deprecato,  Prev: Modifiche al bytecode di CPython,  Up: Novità in Python 3 12

1.3.9 Demos e Tools
-------------------

   * Rimuovi la directory ‘Tools/demo/’ che conteneva vecchi script
     demo.  Una copia può essere trovata nel progetto old-demos(1).
     (Contributo di Victor Stinner in gh-97681(2).)

   * Rimuovi script di esempio obsoleti dalla directory
     ‘Tools/scripts/’.  Una copia può essere trovata nel progetto
     old-demos(3).  (Contributo di Victor Stinner in gh-97669(4).)

   ---------- Footnotes ----------

   (1) https://github.com/gvanrossum/old-demos

   (2) https://github.com/python/cpython/issues/97681

   (3) https://github.com/gvanrossum/old-demos

   (4) https://github.com/python/cpython/issues/97669


File: python.info,  Node: Deprecato,  Next: Rimosso,  Prev: Demos e Tools,  Up: Novità in Python 3 12

1.3.10 Deprecato
----------------

   * *note argparse: 7.: I parametri 'type', 'choices' e 'metavar' di
     ‘argparse.BooleanOptionalAction’ sono deprecati e saranno rimossi
     nella versione 3.14.  (Contributo di Nikita Sobolev in
     gh-92248(1).)

   * *note ast: 9.: Le seguenti caratteristiche di *note ast: 9. sono
     deprecate nella documentazione da Python 3.8, ora causano
     un’emissione di *note DeprecationWarning: 1a3. al runtime quando
     vengono accedute o utilizzate, e saranno rimosse in Python 3.14:

        * ‘ast.Num’

        * ‘ast.Str’

        * ‘ast.Bytes’

        * ‘ast.NameConstant’

        * ‘ast.Ellipsis’

     Utilizzare *note ast.Constant: 2ef. al suo posto.  (Contributo di
     Serhiy Storchaka in gh-90953(2).)

   * *note asyncio: b.:

        * The child watcher classes ‘asyncio.MultiLoopChildWatcher’,
          ‘asyncio.FastChildWatcher’, ‘asyncio.AbstractChildWatcher’ and
          ‘asyncio.SafeChildWatcher’ are deprecated and will be removed
          in Python 3.14.  (Contributed by Kumar Aditya in gh-94597(3).)

        * ‘asyncio.set_child_watcher()’, ‘asyncio.get_child_watcher()’,
          ‘asyncio.AbstractEventLoopPolicy.set_child_watcher()’ and
          ‘asyncio.AbstractEventLoopPolicy.get_child_watcher()’ are
          deprecated and will be removed in Python 3.14.  (Contributed
          by Kumar Aditya in gh-94597(4).)

        * Il metodo *note get_event_loop(): 2f2. della politica del
          ciclo di eventi predefinito ora emette un *note
          DeprecationWarning: 1a3. se non c’è alcun ciclo di eventi
          corrente impostato e decide di crearne uno.  (Contributo di
          Serhiy Storchaka e Guido van Rossum in gh-100160(5).)

   * *note calendar: 15.: Le costanti ‘calendar.January’ e
     ‘calendar.February’ sono deprecate e sostituite da *note
     calendar.JANUARY: 34e. e *note calendar.FEBRUARY: 34f.  (Contributo
     di Prince Roshan in gh-103636(6).)

   * *note collections.abc: 1f.: Deprecated *note
     collections.abc.ByteString: 342.

     Use ‘isinstance(obj, collections.abc.Buffer)’ to test if ‘obj’
     implements the *note buffer protocol: 260. at runtime.  For use in
     type annotations, either use *note Buffer: 343. or a union that
     explicitly specifies the types your code supports (e.g., ‘bytes |
     bytearray | memoryview’).

     ‘ByteString’ was originally intended to be an abstract class that
     would serve as a supertype of both *note bytes: 192. and *note
     bytearray: 344.  However, since the ABC never had any methods,
     knowing that an object was an instance of ‘ByteString’ never
     actually told you anything useful about the object.  Other common
     buffer types such as *note memoryview: 165. were also never
     understood as subtypes of ‘ByteString’ (either at runtime or by
     static type checkers).

     See PEP 688(7) for more details.  (Contributed by Shantanu Jain in
     gh-91896(8).)

   * *note datetime: 34.: I metodi *note utcnow(): 351. e *note
     utcfromtimestamp(): 352. della classe *note datetime.datetime: 4e3.
     sono deprecati e saranno rimossi in una futura versione.  Invece,
     utilizzare oggetti timezone-aware per rappresentare i datetime in
     UTC: rispettivamente, chiamare *note now(): 712. e *note
     fromtimestamp(): 713. con il parametro 'tz' impostato su *note
     datetime.UTC: 714.  (Contributo di Paul Ganssle in gh-103857(9).)

   * *note email: 3f.: Deprecato il parametro 'isdst' in *note
     email.utils.localtime(): 2f7.  (Contributo di Alan Williams in
     gh-72346(10).)

   * *note importlib.abc: 7c.: Deprecate le seguenti classi, pianificate
     per la rimozione in Python 3.14:

        * ‘importlib.abc.ResourceReader’

        * ‘importlib.abc.Traversable’

        * ‘importlib.abc.TraversableResources’

     Utilizzare invece le classi del modulo *note
     importlib.resources.abc: 80.:

        * *note importlib.resources.abc.Traversable: 2fa.

        * *note importlib.resources.abc.TraversableResources: 2f9.

     (Contributo di Jason R. Coombs e Hugo van Kemenade in
     gh-93963(11).)

   * *note itertools: 85.: Deprecato il supporto per operazioni di copy,
     deepcopy e pickle, che è non documentato, inefficiente,
     storicamente soggetto a bug e inconsistente.  Questo sarà rimosso
     in 3.14 per una significativa riduzione del volume di codice e del
     carico di manutenzione.  (Contributo di Raymond Hettinger in
     gh-101588(12).)

   * *note multiprocessing: 98.: In Python 3.14, il metodo di avvio
     predefinito di *note multiprocessing: 98. cambierà in uno più
     sicuro su Linux, BSD e altre piattaforme POSIX non macOS dove
     ‘'fork'’ è attualmente il predefinito (gh-84559(13)).  Aggiungere
     un avviso in fase di runtime su questo cambiamento è stato ritenuto
     troppo dirompente poiché la maggioranza del codice non dovrebbe
     risentirne.  Utilizzare le API *note get_context(): 24a. o *note
     set_start_method(): 24b. per specificare esplicitamente quando il
     codice 'richiede' ‘'fork'’.  Vedi *note contexts and start methods:
     1d5.

   * *note pkgutil: ae.: ‘pkgutil.find_loader()’ and
     ‘pkgutil.get_loader()’ are deprecated and will be removed in Python
     3.14; use *note importlib.util.find_spec(): 5af. instead.
     (Contributed by Nikita Sobolev in gh-97850(14).)

   * *note pty: b6.: Il modulo ha due funzioni non documentate
     ‘master_open()’ e ‘slave_open()’ che sono deprecate da Python 2 ma
     hanno ottenuto un vero e proprio *note DeprecationWarning: 1a3.
     solo in 3.12.  Rimuoverle in 3.14.  (Contributo di Soumendra
     Ganguly e Gregory P. Smith in gh-85984(15).)

   * *note os: a5.:

        * I campi ‘st_ctime’ restituiti da *note os.stat(): 26d. e *note
          os.lstat(): 6c9. su Windows sono deprecati.  In una futura
          versione, conterranno l’ora dell’ultima modifica dei metadati,
          in linea con altre piattaforme.  Per ora, contengono ancora
          l’ora di creazione, che è anche disponibile nel nuovo campo
          ‘st_birthtime’.  (Contributo di Steve Dower in gh-99726(16).)

        * On POSIX platforms, *note os.fork(): 4b6. can now raise a
          *note DeprecationWarning: 1a3. when it can detect being called
          from a multithreaded process.  There has always been a
          fundamental incompatibility with the POSIX platform when doing
          so.  Even if such code 'appeared' to work.  We added the
          warning to raise awareness as issues encountered by code doing
          this are becoming more frequent.  See the *note os.fork():
          4b6. documentation for more details along with this discussion
          on fork being incompatible with threads(17) for 'why' we’re
          now surfacing this longstanding platform compatibility problem
          to developers.

     Quando questo avviso appare a causa dell’uso di *note
     multiprocessing: 98. o *note concurrent.futures: 24. la soluzione è
     di utilizzare un diverso metodo di avvio di *note multiprocessing:
     98. come ‘"spawn"’ o ‘"forkserver"’.

   * *note shutil: ca.: L’argomento 'onerror' di *note shutil.rmtree():
     356. è deprecato; utilizzare 'onexc' invece.  (Contributo di Irit
     Katriel in gh-102828(18).)

   * *note sqlite3: d4.:

        * *note default adapters and converters: 715. sono ora
          deprecati.  Invece, utilizzare *note Adapter and converter
          recipes: 716. e adattarli alle tue esigenze.  (Contributo di
          Erlend E. Aasland in gh-90016(19).)

        * In *note execute(): 5b0, ora viene emesso un *note
          DeprecationWarning: 1a3. quando *note named placeholders: 5b2.
          sono utilizzati insieme a parametri forniti come una *note
          sequence: 717. invece che come un *note dict: 183.  A partire
          da Python 3.14, l’uso di named placeholders con parametri
          forniti come una sequence genererà un *note ProgrammingError:
          305.  (Contributo di Erlend E. Aasland in gh-101698(20).)

   * *note sys: df.: I campi *note sys.last_type: 6e7, *note
     sys.last_value: 6e8. e *note sys.last_traceback: 6e9. sono
     deprecati.  Utilizzare *note sys.last_exc: 6e6. invece.
     (Contributo di Irit Katriel in gh-102778(21).)

   * *note tarfile: e4.: L’estrazione degli archivi tar senza
     specificare 'filter' è deprecata fino a Python 3.14, quando il
     filtro ‘'data'’ diventerà il predefinito.  Vedere *note Extraction
     filters: 698. per i dettagli.

   * *note typing: 10a.:

        * *note typing.Hashable: 718. e *note typing.Sized: 719, alias
          rispettivamente di *note collections.abc.Hashable: 71a. e
          *note collections.abc.Sized: 71b, sono deprecati.
          (gh-94309(22).)

        * *note typing.ByteString: 345, deprecata da Python 3.9, ora
          genera un *note DeprecationWarning: 1a3. quando viene
          utilizzata.  (Contributo di Alex Waygood in gh-91896(23).)

   * *note xml.etree.ElementTree: 12b.: Il modulo ora emette *note
     DeprecationWarning: 1a3. quando si testa il valore di verità di un
     *note xml.etree.ElementTree.Element: 363.  Prima, l’implementazione
     in Python emetteva *note FutureWarning: 659, e l’implementazione in
     C non emetteva nulla.  (Contributo di Jacob Walls in gh-83122(24).)

   * Le firme a 3 argomenti (type, value, traceback) di *note coroutine
     throw(): 71c, *note generator throw(): 71d. e *note async generator
     throw(): 71e. sono deprecate e potrebbero essere rimosse in una
     futura versione di Python.  Utilizzare invece le versioni a un
     singolo argomento di queste funzioni.  (Contributo di Ofey Chan in
     gh-89874(25).)

   * *note DeprecationWarning: 1a3. is now raised when *note
     __package__: 323. on a module differs from *note __spec__.parent:
     324. (previously it was *note ImportWarning: 71f.).  (Contributed
     by Brett Cannon in gh-65961(26).)

   * Setting *note __package__: 323. or *note __cached__: 321. on a
     module is deprecated, and will cease to be set or taken into
     consideration by the import system in Python 3.14.  (Contributed by
     Brett Cannon in gh-65961(27).)

   * The bitwise inversion operator (‘~’) on bool is deprecated.  It
     will throw an error in Python 3.16.  Use ‘not’ for logical negation
     of bools instead.  In the rare case that you really need the
     bitwise inversion of the underlying ‘int’, convert to int
     explicitly: ‘~int(x)’.  (Contributed by Tim Hoffmann in
     gh-103487(28).)

   * Accessing *note co_lnotab: 330. on code objects was deprecated in
     Python 3.10 via PEP 626(29), but it only got a proper *note
     DeprecationWarning: 1a3. in 3.12.  May be removed in 3.15.
     (Contributed by Nikita Sobolev in gh-101866(30).)

* Menu:

* Pending removal in Python 3.13: Pending removal in Python 3 13.
* Pending removal in Python 3.14: Pending removal in Python 3 14<3>.
* Pending removal in Python 3.15: Pending removal in Python 3 15<5>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<5>.
* Pending removal in Python 3.17: Pending removal in Python 3 17<3>.
* Pending removal in future versions: Pending removal in future versions<5>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/92248

   (2) https://github.com/python/cpython/issues/90953

   (3) https://github.com/python/cpython/issues/94597

   (4) https://github.com/python/cpython/issues/94597

   (5) https://github.com/python/cpython/issues/100160

   (6) https://github.com/python/cpython/issues/103636

   (7) https://peps.python.org/pep-0688/#current-options

   (8) https://github.com/python/cpython/issues/91896

   (9) https://github.com/python/cpython/issues/103857

   (10) https://github.com/python/cpython/issues/72346

   (11) https://github.com/python/cpython/issues/93963

   (12) https://github.com/python/cpython/issues/101588

   (13) https://github.com/python/cpython/issues/84559

   (14) https://github.com/python/cpython/issues/97850

   (15) https://github.com/python/cpython/issues/85984

   (16) https://github.com/python/cpython/issues/99726

   (17) 
https://discuss.python.org/t/concerns-regarding-deprecation-of-fork-with-alive-threads/33555

   (18) https://github.com/python/cpython/issues/102828

   (19) https://github.com/python/cpython/issues/90016

   (20) https://github.com/python/cpython/issues/101698

   (21) https://github.com/python/cpython/issues/102778

   (22) https://github.com/python/cpython/issues/94309

   (23) https://github.com/python/cpython/issues/91896

   (24) https://github.com/python/cpython/issues/83122

   (25) https://github.com/python/cpython/issues/89874

   (26) https://github.com/python/cpython/issues/65961

   (27) https://github.com/python/cpython/issues/65961

   (28) https://github.com/python/cpython/issues/103487

   (29) https://peps.python.org/pep-0626/

   (30) https://github.com/python/cpython/issues/101866


File: python.info,  Node: Pending removal in Python 3 13,  Next: Pending removal in Python 3 14<3>,  Up: Deprecato

1.3.10.1 Pending removal in Python 3.13
.......................................

Moduli (vedi PEP 594(1)):

   * ‘aifc’

   * ‘audioop’

   * ‘cgi’

   * ‘cgitb’

   * ‘chunk’

   * ‘crypt’

   * ‘imghdr’

   * ‘mailcap’

   * ‘msilib’

   * ‘nis’

   * ‘nntplib’

   * ‘ossaudiodev’

   * ‘pipes’

   * ‘sndhdr’

   * ‘spwd’

   * ‘sunau’

   * ‘telnetlib’

   * ‘uu’

   * ‘xdrlib’

Altri moduli:

   * ‘lib2to3’, e il programma ‘2to3’ (gh-84540(2))

API:

   * ‘configparser.LegacyInterpolation’ (gh-90765(3))

   * ‘locale.resetlocale()’ (gh-90817(4))

   * ‘turtle.RawTurtle.settiltangle()’ (gh-50096(5))

   * ‘unittest.findTestCases()’ (gh-50096(6))

   * ‘unittest.getTestCaseNames()’ (gh-50096(7))

   * ‘unittest.makeSuite()’ (gh-50096(8))

   * ‘unittest.TestProgram.usageExit()’ (gh-67048(9))

   * ‘webbrowser.MacOSX’ (gh-86421(10))

   * Catena di descrittori *note classmethod: 48f. (gh-89519(11))

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://github.com/python/cpython/issues/84540

   (3) https://github.com/python/cpython/issues/90765

   (4) https://github.com/python/cpython/issues/90817

   (5) https://github.com/python/cpython/issues/50096

   (6) https://github.com/python/cpython/issues/50096

   (7) https://github.com/python/cpython/issues/50096

   (8) https://github.com/python/cpython/issues/50096

   (9) https://github.com/python/cpython/issues/67048

   (10) https://github.com/python/cpython/issues/86421

   (11) https://github.com/python/cpython/issues/89519


File: python.info,  Node: Pending removal in Python 3 14<3>,  Next: Pending removal in Python 3 15<5>,  Prev: Pending removal in Python 3 13,  Up: Deprecato

1.3.10.2 Pending removal in Python 3.14
.......................................

   * *note argparse: 7.: I parametri 'type', 'choices' e 'metavar' di
     ‘argparse.BooleanOptionalAction’ sono deprecati e saranno rimossi
     nella versione 3.14.  (Contributo di Nikita Sobolev in
     gh-92248(1).)

   * *note ast: 9.: The following features have been deprecated in
     documentation since Python 3.8, now cause a *note
     DeprecationWarning: 1a3. to be emitted at runtime when they are
     accessed or used, and will be removed in Python 3.14:

        * ‘ast.Num’

        * ‘ast.Str’

        * ‘ast.Bytes’

        * ‘ast.NameConstant’

        * ‘ast.Ellipsis’

     Utilizzare *note ast.Constant: 2ef. al suo posto.  (Contributo di
     Serhiy Storchaka in gh-90953(2).)

   * *note asyncio: b.:

        * The child watcher classes ‘asyncio.MultiLoopChildWatcher’,
          ‘asyncio.FastChildWatcher’, ‘asyncio.AbstractChildWatcher’ and
          ‘asyncio.SafeChildWatcher’ are deprecated and will be removed
          in Python 3.14.  (Contributed by Kumar Aditya in gh-94597(3).)

        * ‘asyncio.set_child_watcher()’, ‘asyncio.get_child_watcher()’,
          ‘asyncio.AbstractEventLoopPolicy.set_child_watcher()’ and
          ‘asyncio.AbstractEventLoopPolicy.get_child_watcher()’ are
          deprecated and will be removed in Python 3.14.  (Contributed
          by Kumar Aditya in gh-94597(4).)

        * Il metodo *note get_event_loop(): 2f2. della politica del
          ciclo di eventi predefinito ora emette un *note
          DeprecationWarning: 1a3. se non c’è alcun ciclo di eventi
          corrente impostato e decide di crearne uno.  (Contributo di
          Serhiy Storchaka e Guido van Rossum in gh-100160(5).)

   * *note email: 3f.: Deprecated the 'isdst' parameter in *note
     email.utils.localtime(): 2f7.  (Contributed by Alan Williams in
     gh-72346(6).)

   * *note importlib.abc: 7c. deprecated classes:

        * ‘importlib.abc.ResourceReader’

        * ‘importlib.abc.Traversable’

        * ‘importlib.abc.TraversableResources’

     Utilizzare invece le classi del modulo *note
     importlib.resources.abc: 80.:

        * *note importlib.resources.abc.Traversable: 2fa.

        * *note importlib.resources.abc.TraversableResources: 2f9.

     (Contributo di Jason R. Coombs e Hugo van Kemenade in gh-93963(7).)

   * *note itertools: 85. had undocumented, inefficient, historically
     buggy, and inconsistent support for copy, deepcopy, and pickle
     operations.  This will be removed in 3.14 for a significant
     reduction in code volume and maintenance burden.  (Contributed by
     Raymond Hettinger in gh-101588(8).)

   * *note multiprocessing: 98.: The default start method will change to
     a safer one on Linux, BSDs, and other non-macOS POSIX platforms
     where ‘'fork'’ is currently the default (gh-84559(9)).  Adding a
     runtime warning about this was deemed too disruptive as the
     majority of code is not expected to care.  Use the *note
     get_context(): 24a. or *note set_start_method(): 24b. APIs to
     explicitly specify when your code 'requires' ‘'fork'’.  See *note
     Contexts and start methods: 1d5.

   * *note pathlib: a8.: *note is_relative_to(): 2fe. and *note
     relative_to(): 2fd.: passing additional arguments is deprecated.

   * *note pkgutil: ae.: ‘pkgutil.find_loader()’ and
     ‘pkgutil.get_loader()’ now raise *note DeprecationWarning: 1a3.;
     use *note importlib.util.find_spec(): 5af. instead.  (Contributed
     by Nikita Sobolev in gh-97850(10).)

   * *note pty: b6.:

        * ‘master_open()’: use *note pty.openpty(): 301.

        * ‘slave_open()’: use *note pty.openpty(): 301.

   * *note sqlite3: d4.:

        * ‘version’ and ‘version_info’.

        * *note execute(): 5b0. and *note executemany(): 5b1. if *note
          named placeholders: 5b2. are used and 'parameters' is a
          sequence instead of a *note dict: 183.

   * *note urllib: 10e.: ‘urllib.parse.Quoter’ is deprecated: it was not
     intended to be a public API. (Contributed by Gregory P. Smith in
     gh-88168(11).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/92248

   (2) https://github.com/python/cpython/issues/90953

   (3) https://github.com/python/cpython/issues/94597

   (4) https://github.com/python/cpython/issues/94597

   (5) https://github.com/python/cpython/issues/100160

   (6) https://github.com/python/cpython/issues/72346

   (7) https://github.com/python/cpython/issues/93963

   (8) https://github.com/python/cpython/issues/101588

   (9) https://github.com/python/cpython/issues/84559

   (10) https://github.com/python/cpython/issues/97850

   (11) https://github.com/python/cpython/issues/88168


File: python.info,  Node: Pending removal in Python 3 15<5>,  Next: Pending removal in Python 3 16<5>,  Prev: Pending removal in Python 3 14<3>,  Up: Deprecato

1.3.10.3 Pending removal in Python 3.15
.......................................

   * The import system:

        * Setting *note __cached__: 321. on a module while failing to
          set *note __spec__.cached: 322. is deprecated.  In Python
          3.15, ‘__cached__’ will cease to be set or take into
          consideration by the import system or standard library.
          (gh-97879(1))

        * Setting *note __package__: 323. on a module while failing to
          set *note __spec__.parent: 324. is deprecated.  In Python
          3.15, ‘__package__’ will cease to be set or take into
          consideration by the import system or standard library.
          (gh-97879(2))

   * *note ctypes: 2e.:

        * The undocumented ‘ctypes.SetPointerType()’ function has been
          deprecated since Python 3.13.

   * *note http.server: 76.:

        * The obsolete and rarely used *note CGIHTTPRequestHandler: 325.
          has been deprecated since Python 3.13.  No direct replacement
          exists.  'Anything' is better than CGI to interface a web
          server with a request handler.

        * The ‘--cgi’ flag to the ‘python -m http.server’ command-line
          interface has been deprecated since Python 3.13.

   * *note importlib: 7b.:

        * ‘load_module()’ method: use ‘exec_module()’ instead.

   * *note locale: 8a.:

        * The *note getdefaultlocale(): 326. function has been
          deprecated since Python 3.11.  Its removal was originally
          planned for Python 3.13 (gh-90817(3)), but has been postponed
          to Python 3.15.  Use *note getlocale(): 327, *note
          setlocale(): 328, and *note getencoding(): 329. instead.
          (Contributed by Hugo van Kemenade in gh-111187(4).)

   * *note pathlib: a8.:

        * *note PurePath.is_reserved(): 32a. has been deprecated since
          Python 3.13.  Use *note os.path.isreserved(): 32b. to detect
          reserved paths on Windows.

   * *note platform: af.:

        * *note java_ver(): 32c. has been deprecated since Python 3.13.
          This function is only useful for Jython support, has a
          confusing API, and is largely untested.

   * *note sysconfig: e1.:

        * The 'check_home' argument of *note
          sysconfig.is_python_build(): 32d. has been deprecated since
          Python 3.12.

   * *note threading: f3.:

        * *note RLock(): 32e. will take no arguments in Python 3.15.
          Passing any arguments has been deprecated since Python 3.14,
          as the Python version does not permit any arguments, but the C
          version allows any number of positional or keyword arguments,
          ignoring every argument.

   * *note types: 109.:

        * *note types.CodeType: 32f.: Accessing *note co_lnotab: 330.
          was deprecated in PEP 626(5) since 3.10 and was planned to be
          removed in 3.12, but it only got a proper *note
          DeprecationWarning: 1a3. in 3.12.  May be removed in 3.15.
          (Contributed by Nikita Sobolev in gh-101866(6).)

   * *note typing: 10a.:

        * The undocumented keyword argument syntax for creating *note
          NamedTuple: 331. classes (for example, ‘Point =
          NamedTuple("Point", x=int, y=int)’) has been deprecated since
          Python 3.13.  Use the class-based syntax or the functional
          syntax instead.

        * When using the functional syntax of *note TypedDict: 332.s,
          failing to pass a value to the 'fields' parameter (‘TD =
          TypedDict("TD")’) or passing ‘None’ (‘TD = TypedDict("TD",
          None)’) has been deprecated since Python 3.13.  Use ‘class
          TD(TypedDict): pass’ or ‘TD = TypedDict("TD", {})’ to create a
          TypedDict with zero field.

        * The *note typing.no_type_check_decorator(): 333. decorator
          function has been deprecated since Python 3.13.  After eight
          years in the *note typing: 10a. module, it has yet to be
          supported by any major type checker.

   * *note wave: 119.:

        * The *note getmark(): 334, ‘setmark()’, and *note getmarkers():
          335. methods of the *note Wave_read: 336. and *note
          Wave_write: 337. classes have been deprecated since Python
          3.13.

   * *note zipimport: 138.:

        * *note load_module(): 338. has been deprecated since Python
          3.10.  Use *note exec_module(): 339. instead.  (Contributed by
          Jiahao Li in gh-125746(7).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97879

   (2) https://github.com/python/cpython/issues/97879

   (3) https://github.com/python/cpython/issues/90817

   (4) https://github.com/python/cpython/issues/111187

   (5) https://peps.python.org/pep-0626/

   (6) https://github.com/python/cpython/issues/101866

   (7) https://github.com/python/cpython/issues/125746


File: python.info,  Node: Pending removal in Python 3 16<5>,  Next: Pending removal in Python 3 17<3>,  Prev: Pending removal in Python 3 15<5>,  Up: Deprecato

1.3.10.4 Pending removal in Python 3.16
.......................................

   * The import system:

        * Setting *note __loader__: 33b. on a module while failing to
          set *note __spec__.loader: 33c. is deprecated.  In Python
          3.16, ‘__loader__’ will cease to be set or taken into
          consideration by the import system or the standard library.

   * *note array: 8.:

        * The ‘'u'’ format code (‘wchar_t’) has been deprecated in
          documentation since Python 3.3 and at runtime since Python
          3.13.  Use the ‘'w'’ format code (*note Py_UCS4: 33d.) for
          Unicode characters instead.

   * *note asyncio: b.:

        * ‘asyncio.iscoroutinefunction()’ is deprecated and will be
          removed in Python 3.16; use *note
          inspect.iscoroutinefunction(): 30d. instead.  (Contributed by
          Jiahao Li and Kumar Aditya in gh-122875(1).)

        * *note asyncio: b. policy system is deprecated and will be
          removed in Python 3.16.  In particular, the following classes
          and functions are deprecated:

             * *note asyncio.AbstractEventLoopPolicy: 30e.

             * *note asyncio.DefaultEventLoopPolicy: 30f.

             * *note asyncio.WindowsSelectorEventLoopPolicy: 310.

             * *note asyncio.WindowsProactorEventLoopPolicy: 311.

             * *note asyncio.get_event_loop_policy(): 312.

             * *note asyncio.set_event_loop_policy(): 313.

          Users should use *note asyncio.run(): 2f3. or *note
          asyncio.Runner: 2f5. with 'loop_factory' to use the desired
          event loop implementation.

          For example, to use *note asyncio.SelectorEventLoop: 314. on
          Windows:

               import asyncio

               async def main():
                   ...

               asyncio.run(main(), loop_factory=asyncio.SelectorEventLoop)

          (Contributed by Kumar Aditya in gh-127949(2).)

   * *note builtins: 13.:

        * Bitwise inversion on boolean types, ‘~True’ or ‘~False’ has
          been deprecated since Python 3.12, as it produces surprising
          and unintuitive results (‘-2’ and ‘-1’).  Use ‘not x’ instead
          for the logical negation of a Boolean.  In the rare case that
          you need the bitwise inversion of the underlying integer,
          convert to ‘int’ explicitly (‘~int(x)’).

   * *note functools: 63.:

        * Calling the Python implementation of *note functools.reduce():
          21a. with 'function' or 'sequence' as keyword arguments has
          been deprecated since Python 3.14.

   * *note logging: 8b.:

     Support for custom logging handlers with the 'strm' argument is
     deprecated and scheduled for removal in Python 3.16.  Define
     handlers with the 'stream' argument instead.  (Contributed by
     Mariusz Felisiak in gh-115032(3).)

   * *note mimetypes: 93.:

        * Valid extensions start with a “.” or are empty for *note
          mimetypes.MimeTypes.add_type(): 319.  Undotted extensions are
          deprecated and will raise a *note ValueError: 2ec. in Python
          3.16.  (Contributed by Hugo van Kemenade in gh-75223(4).)

   * *note shutil: ca.:

        * The ‘ExecError’ exception has been deprecated since Python
          3.14.  It has not been used by any function in ‘shutil’ since
          Python 3.4, and is now an alias of *note RuntimeError: 244.

   * *note symtable: de.:

        * The *note Class.get_methods: 31d. method has been deprecated
          since Python 3.14.

   * *note sys: df.:

        * The *note _enablelegacywindowsfsencoding(): 33e. function has
          been deprecated since Python 3.13.  Use the *note
          PYTHONLEGACYWINDOWSFSENCODING: 33f. environment variable
          instead.

   * *note sysconfig: e1.:

        * The ‘sysconfig.expand_makefile_vars()’ function has been
          deprecated since Python 3.14.  Use the ‘vars’ argument of
          *note sysconfig.get_paths(): 340. instead.

   * *note tarfile: e4.:

        * The undocumented and unused ‘TarFile.tarfile’ attribute has
          been deprecated since Python 3.13.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/122875

   (2) https://github.com/python/cpython/issues/127949

   (3) https://github.com/python/cpython/issues/115032

   (4) https://github.com/python/cpython/issues/75223


File: python.info,  Node: Pending removal in Python 3 17<3>,  Next: Pending removal in future versions<5>,  Prev: Pending removal in Python 3 16<5>,  Up: Deprecato

1.3.10.5 Pending removal in Python 3.17
.......................................

   * *note collections.abc: 1f.:

        - *note collections.abc.ByteString: 342. is scheduled for
          removal in Python 3.17.

          Use ‘isinstance(obj, collections.abc.Buffer)’ to test if ‘obj’
          implements the *note buffer protocol: 260. at runtime.  For
          use in type annotations, either use *note Buffer: 343. or a
          union that explicitly specifies the types your code supports
          (e.g., ‘bytes | bytearray | memoryview’).

          ‘ByteString’ was originally intended to be an abstract class
          that would serve as a supertype of both *note bytes: 192. and
          *note bytearray: 344.  However, since the ABC never had any
          methods, knowing that an object was an instance of
          ‘ByteString’ never actually told you anything useful about the
          object.  Other common buffer types such as *note memoryview:
          165. were also never understood as subtypes of ‘ByteString’
          (either at runtime or by static type checkers).

          See PEP 688(1) for more details.  (Contributed by Shantanu
          Jain in gh-91896(2).)

   * *note typing: 10a.:

        - Before Python 3.14, old-style unions were implemented using
          the private class ‘typing._UnionGenericAlias’.  This class is
          no longer needed for the implementation, but it has been
          retained for backward compatibility, with removal scheduled
          for Python 3.17.  Users should use documented introspection
          helpers like *note typing.get_origin(): 2ab. and *note
          typing.get_args(): 2ac. instead of relying on private
          implementation details.

        - *note typing.ByteString: 345, deprecated since Python 3.9, is
          scheduled for removal in Python 3.17.

          Use ‘isinstance(obj, collections.abc.Buffer)’ to test if ‘obj’
          implements the *note buffer protocol: 260. at runtime.  For
          use in type annotations, either use *note Buffer: 343. or a
          union that explicitly specifies the types your code supports
          (e.g., ‘bytes | bytearray | memoryview’).

          ‘ByteString’ was originally intended to be an abstract class
          that would serve as a supertype of both *note bytes: 192. and
          *note bytearray: 344.  However, since the ABC never had any
          methods, knowing that an object was an instance of
          ‘ByteString’ never actually told you anything useful about the
          object.  Other common buffer types such as *note memoryview:
          165. were also never understood as subtypes of ‘ByteString’
          (either at runtime or by static type checkers).

          See PEP 688(3) for more details.  (Contributed by Shantanu
          Jain in gh-91896(4).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0688/#current-options

   (2) https://github.com/python/cpython/issues/91896

   (3) https://peps.python.org/pep-0688/#current-options

   (4) https://github.com/python/cpython/issues/91896


File: python.info,  Node: Pending removal in future versions<5>,  Prev: Pending removal in Python 3 17<3>,  Up: Deprecato

1.3.10.6 Pending removal in future versions
...........................................

The following APIs will be removed in the future, although there is
currently no date scheduled for their removal.

   * *note argparse: 7.:

        * Nesting argument groups and nesting mutually exclusive groups
          are deprecated.

        * Passing the undocumented keyword argument 'prefix_chars' to
          *note add_argument_group(): 2eb. is now deprecated.

        * The *note argparse.FileType: 30c. type converter is
          deprecated.

   * *note builtins: 13.:

        * Generators: ‘throw(type, exc, tb)’ and ‘athrow(type, exc, tb)’
          signature is deprecated: use ‘throw(exc)’ and ‘athrow(exc)’
          instead, the single argument signature.

        * Currently Python accepts numeric literals immediately followed
          by keywords, for example ‘0in x’, ‘1or x’, ‘0if 1else 2’.  It
          allows confusing and ambiguous expressions like ‘[0x1for x in
          y]’ (which can be interpreted as ‘[0x1 for x in y]’ or ‘[0x1f
          or x in y]’).  A syntax warning is raised if the numeric
          literal is immediately followed by one of keywords *note and:
          349, *note else: 17c, *note for: 34a, *note if: 181, *note in:
          34b, *note is: 34c. and *note or: 34d.  In a future release it
          will be changed to a syntax error.  (gh-87999(1))

        * Support for ‘__index__()’ and ‘__int__()’ method returning
          non-int type: these methods will be required to return an
          instance of a strict subclass of *note int: 19b.

        * Support for ‘__float__()’ method returning a strict subclass
          of *note float: 196.: these methods will be required to return
          an instance of *note float: 196.

        * Support for ‘__complex__()’ method returning a strict subclass
          of *note complex: 197.: these methods will be required to
          return an instance of *note complex: 197.

        * Delegation of ‘int()’ to ‘__trunc__()’ method.

        * Passing a complex number as the 'real' or 'imag' argument in
          the *note complex(): 197. constructor is now deprecated; it
          should only be passed as a single positional argument.
          (Contributed by Serhiy Storchaka in gh-109218(2).)

   * *note calendar: 15.: Le costanti ‘calendar.January’ e
     ‘calendar.February’ sono deprecate e sostituite da *note
     calendar.JANUARY: 34e. e *note calendar.FEBRUARY: 34f.  (Contributo
     di Prince Roshan in gh-103636(3).)

   * *note codecs: 1c.: use *note open(): 316. instead of *note
     codecs.open(): 315.  (gh-133038(4))

   * *note codeobject.co_lnotab: 330.: use the *note
     codeobject.co_lines(): 350. method instead.

   * *note datetime: 34.:

        * *note utcnow(): 351.: use
          ‘datetime.datetime.now(tz=datetime.UTC)’.

        * *note utcfromtimestamp(): 352.: use
          ‘datetime.datetime.fromtimestamp(timestamp, tz=datetime.UTC)’.

   * *note gettext: 67.: Plural value must be an integer.

   * *note importlib: 7b.:

        * *note cache_from_source(): 353. 'debug_override' parameter is
          deprecated: use the 'optimization' parameter instead.

   * *note importlib.metadata: 7e.:

        * ‘EntryPoints’ tuple interface.

        * Implicit ‘None’ on return values.

   * *note logging: 8b.: the ‘warn()’ method has been deprecated since
     Python 3.3, use *note warning(): 354. instead.

   * *note mailbox: 8f.: Use of StringIO input and text mode is
     deprecated, use BytesIO and binary mode instead.

   * *note os: a5.: Calling *note os.register_at_fork(): 355. in
     multi-threaded process.

   * ‘pydoc.ErrorDuringImport’: A tuple value for 'exc_info' parameter
     is deprecated, use an exception instance.

   * *note re: be.: More strict rules are now applied for numerical
     group references and group names in regular expressions.  Only
     sequence of ASCII digits is now accepted as a numerical reference.
     The group name in bytes patterns and replacement strings can now
     only contain ASCII letters and digits and underscore.  (Contributed
     by Serhiy Storchaka in gh-91760(5).)

   * ‘sre_compile’, ‘sre_constants’ and ‘sre_parse’ modules.

   * *note shutil: ca.: *note rmtree(): 356.”s 'onerror' parameter is
     deprecated in Python 3.12; use the 'onexc' parameter instead.

   * *note ssl: d5. options and protocols:

        * *note ssl.SSLContext: 357. without protocol argument is
          deprecated.

        * *note ssl.SSLContext: 357.: *note set_npn_protocols(): 358.
          and ‘selected_npn_protocol()’ are deprecated: use ALPN
          instead.

        * ‘ssl.OP_NO_SSL*’ options

        * ‘ssl.OP_NO_TLS*’ options

        * ‘ssl.PROTOCOL_SSLv3’

        * ‘ssl.PROTOCOL_TLS’

        * ‘ssl.PROTOCOL_TLSv1’

        * ‘ssl.PROTOCOL_TLSv1_1’

        * ‘ssl.PROTOCOL_TLSv1_2’

        * ‘ssl.TLSVersion.SSLv3’

        * ‘ssl.TLSVersion.TLSv1’

        * ‘ssl.TLSVersion.TLSv1_1’

   * *note threading: f3. methods:

        * ‘threading.Condition.notifyAll()’: use *note notify_all():
          359.

        * ‘threading.Event.isSet()’: use *note is_set(): 35a.

        * ‘threading.Thread.isDaemon()’, *note
          threading.Thread.setDaemon(): 35b.: use *note
          threading.Thread.daemon: 35c. attribute.

        * ‘threading.Thread.getName()’, *note
          threading.Thread.setName(): 35d.: use *note
          threading.Thread.name: 2a0. attribute.

        * ‘threading.currentThread()’: use *note
          threading.current_thread(): 35e.

        * ‘threading.activeCount()’: use *note threading.active_count():
          35f.

   * *note typing.Text: 360. (gh-92332(6)).

   * The internal class ‘typing._UnionGenericAlias’ is no longer used to
     implement *note typing.Union: 2a8.  To preserve compatibility with
     users using this private class, a compatibility shim will be
     provided until at least Python 3.17.  (Contributed by Jelle
     Zijlstra in gh-105499(7).)

   * *note unittest.IsolatedAsyncioTestCase: 361.: it is deprecated to
     return a value that is not ‘None’ from a test case.

   * *note urllib.parse: 110. deprecated functions: *note urlparse():
     362. instead

        * ‘splitattr()’

        * ‘splithost()’

        * ‘splitnport()’

        * ‘splitpasswd()’

        * ‘splitport()’

        * ‘splitquery()’

        * ‘splittag()’

        * ‘splittype()’

        * ‘splituser()’

        * ‘splitvalue()’

        * ‘to_bytes()’

   * *note wsgiref: 11e.: ‘SimpleHandler.stdout.write()’ should not do
     partial writes.

   * *note xml.etree.ElementTree: 12b.: Testing the truth value of an
     *note Element: 363. is deprecated.  In a future release it will
     always return ‘True’.  Prefer explicit ‘len(elem)’ or ‘elem is not
     None’ tests instead.

   * *note sys._clear_type_cache(): 292. is deprecated: use *note
     sys._clear_internal_caches(): 364. instead.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/87999

   (2) https://github.com/python/cpython/issues/109218

   (3) https://github.com/python/cpython/issues/103636

   (4) https://github.com/python/cpython/issues/133038

   (5) https://github.com/python/cpython/issues/91760

   (6) https://github.com/python/cpython/issues/92332

   (7) https://github.com/python/cpython/issues/105499


File: python.info,  Node: Rimosso,  Next: Porting a Python 3 12,  Prev: Deprecato,  Up: Novità in Python 3 12

1.3.11 Rimosso
--------------

* Menu:

* asynchat e asyncore::
* configparser: configparser<4>.
* distutils::
* ensurepip::
* enum: enum<2>.
* ftplib::
* gzip::
* hashlib::
* importlib: importlib<2>.
* imp::
* io: io<4>.
* locale: locale<2>.
* smtpd::
* sqlite3: sqlite3<4>.
* ssl: ssl<3>.
* unittest: unittest<4>.
* webbrowser: webbrowser<3>.
* xml.etree.ElementTree: xml etree ElementTree.
* zipimport: zipimport<2>.
* Altri::


File: python.info,  Node: asynchat e asyncore,  Next: configparser<4>,  Up: Rimosso

1.3.11.1 asynchat e asyncore
............................

   * Questi due moduli sono stati rimossi secondo il programma in PEP
     594(1), essendo stati deprecati in Python 3.6.  Utilizzare *note
     asyncio: b. invece.  (Contribuito da Nikita Sobolev in
     gh-96580(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://github.com/python/cpython/issues/96580


File: python.info,  Node: configparser<4>,  Next: distutils,  Prev: asynchat e asyncore,  Up: Rimosso

1.3.11.2 configparser
.....................

   * Diversi nomi deprecati nel *note configparser: 26. fin dalla
     versione 3.2 sono stati rimossi per gh-89336(1):

        * *note configparser.ParsingError: 72a. non ha più un attributo
          o argomento ‘filename’.  Utilizzare al suo posto l’attributo e
          l’argomento ‘source’.

        * *note configparser: 26. non ha più una classe
          ‘SafeConfigParser’.  Utilizzare al suo posto il nome più breve
          *note ConfigParser: 4df.

        * *note configparser.ConfigParser: 4df. non ha più un metodo
          ‘readfp’.  Utilizzare al suo posto *note read_file(): 72b.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89336


File: python.info,  Node: distutils,  Next: ensurepip,  Prev: configparser<4>,  Up: Rimosso

1.3.11.3 distutils
..................

   * Rimozione del pacchetto ‘distutils’.  È stato deprecato in Python
     3.10 da PEP 632(1) «Deprecazione del modulo distutils».  Per i
     progetti che ancora utilizzano ‘distutils’ e non possono essere
     aggiornati ad altro, il progetto ‘setuptools’ può essere
     installato: fornisce ancora ‘distutils’.  (Contribuito da Victor
     Stinner in gh-92584(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0632/

   (2) https://github.com/python/cpython/issues/92584


File: python.info,  Node: ensurepip,  Next: enum<2>,  Prev: distutils,  Up: Rimosso

1.3.11.4 ensurepip
..................

   * Rimozione della ruota setuptools inclusa in *note ensurepip: 59, e
     cessazione dell’installazione di setuptools negli ambienti creati
     da *note venv: 117.

     ‘pip (>= 22.1)’ non richiede che setuptools sia installato
     nell’ambiente.  I pacchetti basati su ‘setuptools’ (e su
     ‘distutils’) possono ancora essere utilizzati con ‘pip install’,
     poiché pip fornirà ‘setuptools’ nell’ambiente di build che utilizza
     per costruire un pacchetto.

     ‘easy_install’, ‘pkg_resources’, ‘setuptools’ e ‘distutils’ non
     sono più forniti di default negli ambienti creati con ‘venv’ o
     bootstrap con ‘ensurepip’, poiché fanno parte del pacchetto
     ‘setuptools’.  Per i progetti che dipendono da questi a runtime, il
     progetto ‘setuptools’ dovrebbe essere dichiarato come una
     dipendenza e installato separatamente (tipicamente, utilizzando
     pip).

     (Contribuito da Pradyun Gedam in gh-95299(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/95299


File: python.info,  Node: enum<2>,  Next: ftplib,  Prev: ensurepip,  Up: Rimosso

1.3.11.5 enum
.............

   * Rimozione di ‘EnumMeta.__getattr__’ di *note enum: 5a, che non è
     più necessario per l’accesso agli attributi degli enum.
     (Contribuito da Ethan Furman in gh-95083(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/95083


File: python.info,  Node: ftplib,  Next: gzip,  Prev: enum<2>,  Up: Rimosso

1.3.11.6 ftplib
...............

   * Rimozione dell’attributo di classe ‘FTP_TLS.ssl_version’ di *note
     ftplib: 62.: utilizzare invece il parametro 'context'.
     (Contribuito da Victor Stinner in gh-94172(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94172


File: python.info,  Node: gzip,  Next: hashlib,  Prev: ftplib,  Up: Rimosso

1.3.11.7 gzip
.............

   * Rimozione dell’attributo ‘filename’ di *note gzip.GzipFile: 65c. di
     *note gzip: 6b, deprecato dalla versione Python 2.6, utilizzare
     invece l’attributo *note name: 732.  In modalità scrittura,
     l’attributo ‘filename’ aggiungeva l’estensione di file ‘'.gz'’ se
     non era presente.  (Contribuito da Victor Stinner in gh-94196(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94196


File: python.info,  Node: hashlib,  Next: importlib<2>,  Prev: gzip,  Up: Rimosso

1.3.11.8 hashlib
................

   * Remove the pure Python implementation of *note hashlib: 6c.’s *note
     hashlib.pbkdf2_hmac(): 734, deprecated in Python 3.10.  Python 3.10
     and newer requires OpenSSL 1.1.1 ( PEP 644(1)): this OpenSSL
     version provides a C implementation of *note pbkdf2_hmac(): 734.
     which is faster.  (Contributed by Victor Stinner in gh-94199(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0644/

   (2) https://github.com/python/cpython/issues/94199


File: python.info,  Node: importlib<2>,  Next: imp,  Prev: hashlib,  Up: Rimosso

1.3.11.9 importlib
..................

   * Molti di precedenti deprecazioni in *note importlib: 7b. sono ora
     state completate:

        * References to, and support for ‘module_repr()’ has been
          removed.  (Contributed by Barry Warsaw in gh-97850(1).)

        * ‘importlib.util.set_package’, ‘importlib.util.set_loader’ e
          ‘importlib.util.module_for_loader’ sono stati tutti rimossi.
          (Contribuito da Brett Cannon e Nikita Sobolev in gh-65961(2) e
          gh-97850(3).)

        * Il supporto per le API ‘find_loader()’ e ‘find_module()’ è
          stato rimosso.  (Contribuito da Barry Warsaw in gh-98040(4).)

        * ‘importlib.abc.Finder’, ‘pkgutil.ImpImporter’ e
          ‘pkgutil.ImpLoader’ sono stati rimossi.  (Contribuito da Barry
          Warsaw in gh-98040(5).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97850

   (2) https://github.com/python/cpython/issues/65961

   (3) https://github.com/python/cpython/issues/97850

   (4) https://github.com/python/cpython/issues/98040

   (5) https://github.com/python/cpython/issues/98040


File: python.info,  Node: imp,  Next: io<4>,  Prev: importlib<2>,  Up: Rimosso

1.3.11.10 imp
.............

   * Il modulo ‘imp’ è stato rimosso.  (Contribuito da Barry Warsaw in
     gh-98040(1).)

     Per migrare, consultare la seguente tabella di corrispondenza:

          imp                                   importlib
                                                
          --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                
          ‘imp.NullImporter’                    Inserire ‘None’ in ‘sys.path_importer_cache’
                                                
                                                
          ‘imp.cache_from_source()’             *note importlib.util.cache_from_source(): 353.
                                                
                                                
          ‘imp.find_module()’                   *note importlib.util.find_spec(): 5af.
                                                
                                                
          ‘imp.get_magic()’                     *note importlib.util.MAGIC_NUMBER: 738.
                                                
                                                
          ‘imp.get_suffixes()’                  *note importlib.machinery.SOURCE_SUFFIXES: 739, *note importlib.machinery.EXTENSION_SUFFIXES: 73a, and
                                                *note importlib.machinery.BYTECODE_SUFFIXES: 73b.
                                                
                                                
          ‘imp.get_tag()’                       *note sys.implementation.cache_tag: 73c.
                                                
                                                
          ‘imp.load_module()’                   *note importlib.import_module(): 73d.
                                                
                                                
          ‘imp.new_module(name)’                ‘types.ModuleType(name)’
                                                
                                                
          ‘imp.reload()’                        *note importlib.reload(): 73e.
                                                
                                                
          ‘imp.source_from_cache()’             *note importlib.util.source_from_cache(): 73f.
                                                
                                                
          ‘imp.load_source()’                   'Vedi sotto'
                                                

     Sostituire ‘imp.load_source()’ con:

          import importlib.util
          import importlib.machinery

          def load_source(modname, filename):
              loader = importlib.machinery.SourceFileLoader(modname, filename)
              spec = importlib.util.spec_from_file_location(modname, filename, loader=loader)
              module = importlib.util.module_from_spec(spec)
              # The module is always executed and not cached in sys.modules.
              # Uncomment the following line to cache the module.
              # sys.modules[module.__name__] = module
              loader.exec_module(module)
              return module

   * Rimuovere le funzioni e gli attributi di ‘imp’ senza sostituzioni:

        * Funzioni non documentate:

             * ‘imp.init_builtin()’

             * ‘imp.load_compiled()’

             * ‘imp.load_dynamic()’

             * ‘imp.load_package()’

        * ‘imp.lock_held()’, ‘imp.acquire_lock()’, ‘imp.release_lock()’:
          lo schema di blocco è cambiato in Python 3.3 a blocchi per
          modulo.

        * Costanti di ‘imp.find_module()’: ‘SEARCH_ERROR’, ‘PY_SOURCE’,
          ‘PY_COMPILED’, ‘C_EXTENSION’, ‘PY_RESOURCE’, ‘PKG_DIRECTORY’,
          ‘C_BUILTIN’, ‘PY_FROZEN’, ‘PY_CODERESOURCE’, ‘IMP_HOOK’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98040


File: python.info,  Node: io<4>,  Next: locale<2>,  Prev: imp,  Up: Rimosso

1.3.11.11 io
............

   * Rimuovere ‘io.OpenWrapper’ di *note io: 83. e ‘_pyio.OpenWrapper’,
     deprecati in Python 3.10: utilizzare semplicemente *note open():
     316.  La funzione *note open(): 316. (*note io.open(): 741.) è una
     funzione integrata.  Dalla versione 3.10 di Python, ‘_pyio.open()’
     è anche un metodo statico.  (Contributo di Victor Stinner in
     gh-94169(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94169


File: python.info,  Node: locale<2>,  Next: smtpd,  Prev: io<4>,  Up: Rimosso

1.3.11.12 locale
................

   * Rimuovere la funzione ‘locale.format()’ di *note locale: 8a,
     deprecata in Python 3.7: usare invece *note locale.format_string():
     743.  (Contributo di Victor Stinner in gh-94226(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94226


File: python.info,  Node: smtpd,  Next: sqlite3<4>,  Prev: locale<2>,  Up: Rimosso

1.3.11.13 smtpd
...............

   * Il modulo ‘smtpd’ è stato rimosso secondo il programma di PEP
     594(1), essendo stato deprecato in Python 3.4.7 e 3.5.4.
     Utilizzare il modulo PyPI aiosmtpd(2) o qualsiasi altro server
     basato su *note asyncio: b.  (Contributo di Oleg Iarygin in
     gh-93243(3).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://pypi.org/project/aiosmtpd/

   (3) https://github.com/python/cpython/issues/93243


File: python.info,  Node: sqlite3<4>,  Next: ssl<3>,  Prev: smtpd,  Up: Rimosso

1.3.11.14 sqlite3
.................

   * Le seguenti funzionalità non documentate di *note sqlite3: d4,
     deprecate in Python 3.10, sono ora rimosse:

        * ‘sqlite3.enable_shared_cache()’

        * ‘sqlite3.OptimizedUnicode’

     Se è necessario utilizzare una cache condivisa, aprire il database
     in modalità URI utilizzando il parametro di query ‘cache=shared’.

     La text factory ‘sqlite3.OptimizedUnicode’ è stata un alias per
     *note str: 169. fin dalla versione 3.3 di Python.  Il codice che
     precedentemente impostava la text factory su ‘OptimizedUnicode’ può
     utilizzare esplicitamente ‘str’, o affidarsi al valore predefinito
     che è anch’esso ‘str’.

     (Contributo di Erlend E. Aasland in gh-92548(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/92548


File: python.info,  Node: ssl<3>,  Next: unittest<4>,  Prev: sqlite3<4>,  Up: Rimosso

1.3.11.15 ssl
.............

   * Rimuovere la funzione ‘ssl.RAND_pseudo_bytes()’ di *note ssl: d5,
     deprecata in Python 3.6: utilizzare invece *note os.urandom(): 747.
     o *note ssl.RAND_bytes(): 748.  (Contributo di Victor Stinner in
     gh-94199(1).)

   * Rimuovere la funzione ‘ssl.match_hostname()’.  È stata deprecata in
     Python 3.7.  OpenSSL esegue il confronto degli hostname dalla
     versione 3.7 di Python, Python non utilizza più la funzione
     ‘ssl.match_hostname()’.  (Contributo di Victor Stinner in
     gh-94199(2).)

   * Rimuovere la funzione ‘ssl.wrap_socket()’, deprecata in Python 3.7:
     creare invece un oggetto *note ssl.SSLContext: 357. e chiamare il
     suo metodo *note ssl.SSLContext.wrap_socket: 749.  Qualsiasi
     pacchetto che utilizza ancora ‘ssl.wrap_socket()’ è rotto e non
     sicuro.  La funzione non invia né un’estensione TLS SNI né valida
     l’hostname del server.  Il codice è soggetto a CWE 295(3)
     (Validazione Impropria del Certificato).  (Contributo di Victor
     Stinner in gh-94199(4).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94199

   (2) https://github.com/python/cpython/issues/94199

   (3) https://cwe.mitre.org/data/definitions/295.html

   (4) https://github.com/python/cpython/issues/94199


File: python.info,  Node: unittest<4>,  Next: webbrowser<3>,  Prev: ssl<3>,  Up: Rimosso

1.3.11.16 unittest
..................

   * Rimuovere molte funzionalità di *note unittest: 10c. deprecate da
     lungo tempo:

        * Un certo numero di alias di metodo di *note TestCase: 2b3.:

          Alias deprecato                  Nome del Metodo                     Deprecato in
                                                                               
          -----------------------------------------------------------------------------------------
                                                                               
          ‘failUnless’                     *note assertTrue(): 74b.            3.1
                                                                               
                                                                               
          ‘failIf’                         *note assertFalse(): 74c.           3.1
                                                                               
                                                                               
          ‘failUnlessEqual’                *note assertEqual(): 74d.           3.1
                                                                               
                                                                               
          ‘failIfEqual’                    *note assertNotEqual(): 74e.        3.1
                                                                               
                                                                               
          ‘failUnlessAlmostEqual’          *note assertAlmostEqual(): 74f.     3.1
                                                                               
                                                                               
          ‘failIfAlmostEqual’              *note assertNotAlmostEqual(): 750.  3.1
                                                                               
                                                                               
          ‘failUnlessRaises’               *note assertRaises(): 751.          3.1
                                                                               
                                                                               
          ‘assert_’                        *note assertTrue(): 74b.            3.2
                                                                               
                                                                               
          ‘assertEquals’                   *note assertEqual(): 74d.           3.2
                                                                               
                                                                               
          ‘assertNotEquals’                *note assertNotEqual(): 74e.        3.2
                                                                               
                                                                               
          ‘assertAlmostEquals’             *note assertAlmostEqual(): 74f.     3.2
                                                                               
                                                                               
          ‘assertNotAlmostEquals’          *note assertNotAlmostEqual(): 750.  3.2
                                                                               
                                                                               
          ‘assertRegexpMatches’            *note assertRegex(): 752.           3.2
                                                                               
                                                                               
          ‘assertRaisesRegexp’             *note assertRaisesRegex(): 753.     3.2
                                                                               
                                                                               
          ‘assertNotRegexpMatches’         *note assertNotRegex(): 754.        3.5
                                                                               

          Puoi usare ‘https://github.com/isidentical/teyit’ per
          modernizzare automaticamente i tuoi test unitari.

        * Metodo *note TestCase: 2b3. ‘assertDictContainsSubset’ non
          documentato e malfunzionante (deprecato in Python 3.2).

        * Parametro non documentato *note
          TestLoader.loadTestsFromModule: 594. 'use_load_tests'
          (deprecato e ignorato da Python 3.5).

        * Un alias della classe *note TextTestResult: 755.:
          ‘_TextTestResult’ (deprecato in Python 3.2).

     (Contribuito da Serhiy Storchaka in gh-89325(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89325


File: python.info,  Node: webbrowser<3>,  Next: xml etree ElementTree,  Prev: unittest<4>,  Up: Rimosso

1.3.11.17 webbrowser
....................

   * Rimuovi il supporto per i browser obsoleti da *note webbrowser:
     11b.  I browser rimossi includono: Grail, Mosaic, Netscape, Galeon,
     Skipstone, Iceape, Firebird e le versioni di Firefox fino alla 35
     (gh-102871(1)).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102871


File: python.info,  Node: xml etree ElementTree,  Next: zipimport<2>,  Prev: webbrowser<3>,  Up: Rimosso

1.3.11.18 xml.etree.ElementTree
...............................

   * Rimuovi il metodo ‘ElementTree.Element.copy()’ dell’implementazione
     pura in Python, deprecato in Python 3.10, usa invece la funzione
     *note copy.copy(): 758.  L’implementazione in C di *note
     xml.etree.ElementTree: 12b. non ha metodo ‘copy()’, ma solo un
     metodo ‘__copy__()’.  (Contribuito da Victor Stinner in
     gh-94383(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94383


File: python.info,  Node: zipimport<2>,  Next: Altri,  Prev: xml etree ElementTree,  Up: Rimosso

1.3.11.19 zipimport
...................

   * Rimuovi i metodi ‘find_loader()’ e ‘find_module()’ di *note
     zipimport: 138, deprecati in Python 3.10: usa invece il metodo
     ‘find_spec()’.  Vedi PEP 451(1) per la spiegazione.  (Contribuito
     da Victor Stinner in gh-94379(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0451/

   (2) https://github.com/python/cpython/issues/94379


File: python.info,  Node: Altri,  Prev: zipimport<2>,  Up: Rimosso

1.3.11.20 Altri
...............

   * Rimuovi la regola ‘suspicious’ dal ‘Makefile’ della documentazione
     e da ‘Doc/tools/rstlint.py’, entrambe a favore di sphinx-lint(1).
     (Contribuito da Julien Palard in gh-98179(2).)

   * Rimuovi i parametri 'keyfile' e 'certfile' dai moduli *note ftplib:
     62, *note imaplib: 78, *note poplib: b1. e *note smtplib: cf, e i
     parametri 'key_file', 'cert_file' e 'check_hostname' dal modulo
     *note http.client: 73, tutti deprecati da Python 3.6.  Usa invece
     il parametro 'context' ('ssl_context' in *note imaplib: 78.).
     (Contribuito da Victor Stinner in gh-94172(3).)

   * Rimuovi hack di compatibilità con ‘Jython’ da diversi moduli e test
     della stdlib.  (Contribuito da Nikita Sobolev in gh-99482(4).)

   * Rimuovi il flag ‘_use_broken_old_ctypes_structure_semantics_’ dal
     modulo *note ctypes: 2e.  (Contribuito da Nikita Sobolev in
     gh-99285(5).)

   ---------- Footnotes ----------

   (1) https://github.com/sphinx-contrib/sphinx-lint

   (2) https://github.com/python/cpython/issues/98179

   (3) https://github.com/python/cpython/issues/94172

   (4) https://github.com/python/cpython/issues/99482

   (5) https://github.com/python/cpython/issues/99285


File: python.info,  Node: Porting a Python 3 12,  Next: Modifiche alla Build,  Prev: Rimosso,  Up: Novità in Python 3 12

1.3.12 Porting a Python 3.12
----------------------------

Questa sezione elenca i cambiamenti precedentemente descritti e altre
correzioni di bug che potrebbero richiedere modifiche al tuo codice.

* Menu:

* Modifiche nell’API di Python::


File: python.info,  Node: Modifiche nell’API di Python,  Up: Porting a Python 3 12

1.3.12.1 Modifiche nell’API di Python
.....................................

   * Ora si applicano regole più severe per i riferimenti di gruppo
     numerici e i nomi di gruppo nelle espressioni regolari.  Sono
     accettati solo riferimenti numerici che sono una sequenza di cifre
     ASCII. Il nome del gruppo nei pattern in bytes e nelle stringhe di
     sostituzione ora può contenere solo lettere e cifre ASCII e il
     carattere di sottolineatura.  (Contribuito da Serhiy Storchaka in
     gh-91760(1).)

   * Rimosso il funzionamento di ‘randrange()’ deprecato da Python 3.10.
     In precedenza, ‘randrange(10.0)’ veniva convertito senza perdita a
     ‘randrange(10)’.  Ora solleva un’eccezione *note TypeError: 198.
     Inoltre, l’eccezione sollevata per valori non interi come
     ‘randrange(10.5)’ o ‘randrange('10')’ è cambiata da *note
     ValueError: 2ec. a *note TypeError: 198.  Questo impedisce anche
     bug dove ‘randrange(1e25)’ selezionava silenziosamente da un
     intervallo più ampio rispetto a ‘randrange(10**25)’.
     (Originariamente suggerito da Serhiy Storchaka gh-86388(2).)

   * *note argparse.ArgumentParser: 1bd. ha cambiato la codifica e il
     gestore di errori per la lettura degli argomenti dai file (ad
     esempio l’opzione ‘fromfile_prefix_chars’) dalla codifica di testo
     predefinita (ad esempio *note locale.getpreferredencoding(False):
     75d.) a *note filesystem encoding and error handler: 75e.  I file
     degli argomenti dovrebbero essere codificati in UTF-8 invece che in
     ANSI Codepage su Windows.

   * Rimosso il modulo ‘smtpd’ basato su ‘asyncore’ deprecato in Python
     3.4.7 e 3.5.4.  Una sostituzione raccomandata è il modulo PyPI
     *note asyncio: b.-based aiosmtpd(3).

   * *note shlex.split(): 75f.: Passare ‘None’ per l’argomento 's' ora
     solleva un’eccezione, invece di leggere da *note sys.stdin: 760.
     La funzionalità è stata deprecata in Python 3.9.  (Contribuito da
     Victor Stinner in gh-94352(4).)

   * Il modulo *note os: a5. non accetta più percorsi di tipo bytes,
     come *note bytearray: 344. e *note memoryview: 165.: solo il tipo
     esatto *note bytes: 192. è accettato per stringhe di tipo bytes.
     (Contribuito da Victor Stinner in gh-98393(5).)

   * *note syslog.openlog(): 761. e *note syslog.closelog(): 762. ora
     falliscono se utilizzati nei subinterpreti.  *note syslog.syslog():
     763. può ancora essere usato nei subinterpreti, ma solo se *note
     syslog.openlog(): 761. è stato già chiamato nel main interpreter.
     Queste nuove restrizioni non si applicano al main interpreter,
     quindi solo un insieme molto ristretto di utenti potrebbe essere
     interessato.  Questa modifica aiuta con l’isolamento degli
     interpreti.  Inoltre, *note syslog: e2. è un wrapper attorno a
     risorse globali del processo, che sono meglio gestite dal main
     interpreter.  (Contribuito da Donghee Na in gh-99127(6).)

   * Il comportamento di blocco non documentato di *note
     cached_property(): 764. è stato rimosso, perché bloccava tutte le
     istanze della classe, portando a una forte contention dei lock.
     Questo significa che ora una funzione getter della proprietà in
     cache potrebbe essere eseguita più di una volta per una singola
     istanza, se due thread sono in competizione.  Per la maggior parte
     delle proprietà in cache semplici (ad esempio quelle che sono
     idempotenti e calcolano semplicemente un valore basato su altri
     attributi dell’istanza) questo sarà accettabile.  Se è necessaria
     la sincronizzazione, implementare il locking all’interno della
     funzione getter della proprietà in cache o intorno ai punti di
     accesso multi-thread.

   * *note sys._current_exceptions(): 6ea. ora restituisce una mappa da
     thread-id a un’istanza di eccezione, anziché a una tupla ‘(typ,
     exc, tb)’.  (Contribuito da Irit Katriel in gh-103176(7).)

   * Quando si estraggono file tar usando *note tarfile: e4. o *note
     shutil.unpack_archive(): 697, passare l’argomento 'filter' per
     limitare le funzionalità che possono essere sorprendenti o
     pericolose.  Vedere *note Extraction filters: 698. per i dettagli.

   * L’output delle funzioni *note tokenize.tokenize(): 701. e *note
     tokenize.generate_tokens(): 702. è ora cambiato a causa delle
     modifiche introdotte in PEP 701(8).  Questo significa che i token
     ‘STRING’ non sono più emessi per le f-string e i token descritti in
     PEP 701(9) sono ora prodotti al loro posto: ‘FSTRING_START’,
     ‘FSTRING_MIDDLE’ e ‘FSTRING_END’ sono ora emessi per le parti
     «string» delle f-string in aggiunta ai token appropriati per la
     tokenizzazione nei componenti di espressione.  Ad esempio, per la
     f-string ‘f"start {1+1} end"’ la vecchia versione del tokenizer
     emetteva:

          1,0-1,18:           STRING         'f"start {1+1} end"'

     mentre la nuova versione emette:

          1,0-1,2:            FSTRING_START  'f"'
          1,2-1,8:            FSTRING_MIDDLE 'start '
          1,8-1,9:            OP             '{'
          1,9-1,10:           NUMBER         '1'
          1,10-1,11:          OP             '+'
          1,11-1,12:          NUMBER         '1'
          1,12-1,13:          OP             '}'
          1,13-1,17:          FSTRING_MIDDLE ' end'
          1,17-1,18:          FSTRING_END    '"'

     Inoltre, potrebbero esserci alcuni cambiamenti comportamentali
     minori come conseguenza delle modifiche necessarie per supportare
     PEP 701(10).  Alcuni di questi cambiamenti includono:

        * L’attributo ‘type’ dei token emessi quando si tokenizzano
          alcuni caratteri Python non validi come ‘!’ è cambiato da
          ‘ERRORTOKEN’ a ‘OP’.

        * Le stringhe a riga singola incomplete ora sollevano *note
          tokenize.TokenError: 765. come fanno le stringhe multilinea
          incomplete.

        * Alcuni codici Python incompleti o non validi ora sollevano
          *note tokenize.TokenError: 765. invece di restituire token
          ‘ERRORTOKEN’ arbitrari durante la tokenizzazione.

        * La miscelazione di tabulazioni e spazi come indentazione nello
          stesso file non è più supportata e genererà un’eccezione *note
          TabError: 766.

   * Il modulo *note threading: f3. ora si aspetta che il modulo
     ‘_thread’ abbia un attributo ‘_is_main_interpreter’.  È una
     funzione senza argomenti che restituisce ‘True’ se l’interprete
     corrente è il main interpreter.

     Qualsiasi libreria o applicazione che fornisce un modulo ‘_thread’
     personalizzato dovrebbe fornire ‘_is_main_interpreter()’.  (Vedere
     gh-112826(11).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91760

   (2) https://github.com/python/cpython/issues/86388

   (3) https://pypi.org/project/aiosmtpd/

   (4) https://github.com/python/cpython/issues/94352

   (5) https://github.com/python/cpython/issues/98393

   (6) https://github.com/python/cpython/issues/99127

   (7) https://github.com/python/cpython/issues/103176

   (8) https://peps.python.org/pep-0701/

   (9) https://peps.python.org/pep-0701/

   (10) https://peps.python.org/pep-0701/

   (11) https://github.com/python/cpython/issues/112826


File: python.info,  Node: Modifiche alla Build,  Next: Modifiche all’API C,  Prev: Porting a Python 3 12,  Up: Novità in Python 3 12

1.3.13 Modifiche alla Build
---------------------------

   * Python non utilizza più ‘setup.py’ per costruire moduli di
     estensione C condivisi.  I parametri di build come intestazioni e
     librerie sono rilevati nello script ‘configure’.  Le estensioni
     sono costruite da ‘Makefile’.  La maggior parte delle estensioni
     utilizza ‘pkg-config’ e ricorre al rilevamento manuale.
     (Contribuito da Christian Heimes in gh-93939(1).)

   * ‘va_start()’ con due parametri, come ‘va_start(args, format),’ è
     ora richiesto per costruire Python.  ‘va_start()’ non viene più
     chiamato con un solo parametro.  (Contribuito da Kumar Aditya in
     gh-93207(2).)

   * CPython ora utilizza l’opzione ThinLTO come politica predefinita di
     ottimizzazione del tempo di link se il compilatore Clang accetta il
     flag.  (Contribuito da Donghee Na in gh-89536(3).)

   * Aggiunta la variabile ‘COMPILEALL_OPTS’ in ‘Makefile’ per
     sovrascrivere le opzioni di *note compileall: 21. (predefinito:
     ‘-j0’) in ‘make install’.  Inoltre, combinati i 3 comandi
     ‘compileall’ in un unico comando per costruire i file .pyc per
     tutti i livelli di ottimizzazione (0, 1, 2) in una volta.
     (Contribuito da Victor Stinner in gh-99289(4).)

   * Aggiunti triplette di piattaforma per LoongArch a 64 bit:

        * loongarch64-linux-gnusf

        * loongarch64-linux-gnuf32

        * loongarch64-linux-gnu

     (Contribuito da Zhang Na in gh-90656(5).)

   * ‘PYTHON_FOR_REGEN’ ora richiede Python 3.10 o versioni successive.

   * Autoconf 2.71 and aclocal 1.16.4 is now required to regenerate
     ‘configure’.  (Contributed by Christian Heimes in gh-89886(6).)

   * Le build di Windows e gli installer per macOS da python.org ora
     utilizzano OpenSSL 3.0.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/93939

   (2) https://github.com/python/cpython/issues/93207

   (3) https://github.com/python/cpython/issues/89536

   (4) https://github.com/python/cpython/issues/99289

   (5) https://github.com/python/cpython/issues/90656

   (6) https://github.com/python/cpython/issues/89886


File: python.info,  Node: Modifiche all’API C,  Prev: Modifiche alla Build,  Up: Novità in Python 3 12

1.3.14 Modifiche all’API C
--------------------------

* Menu:

* Nuove Funzionalità: Nuove Funzionalità<2>.
* Porting a Python 3.12: Porting a Python 3 12<2>.
* Deprecato: Deprecato<2>.
* Rimosso: Rimosso<2>.


File: python.info,  Node: Nuove Funzionalità<2>,  Next: Porting a Python 3 12<2>,  Up: Modifiche all’API C

1.3.14.1 Nuove Funzionalità
...........................

   * PEP 697(1): Introdotta la *note Unstable C API tier: 76a, destinata
     a strumenti di basso livello come debugger e compilatori JIT.
     Questa API può cambiare in ogni rilascio minore di CPython senza
     avvisi di deprecazione.  I suoi contenuti sono contrassegnati dal
     prefisso ‘PyUnstable_’ nei nomi.

     Costruttori di oggetti Code:

        - ‘PyUnstable_Code_New()’ (rinominato da ‘PyCode_New’)

        - ‘PyUnstable_Code_NewWithPosOnlyArgs()’ (rinominato da
          ‘PyCode_NewWithPosOnlyArgs’)

     Archiviazione extra per oggetti code ( PEP 523(2)):

        - ‘PyUnstable_Eval_RequestCodeExtraIndex()’ (rinominato da
          ‘_PyEval_RequestCodeExtraIndex’)

        - ‘PyUnstable_Code_GetExtra()’ (rinominato da
          ‘_PyCode_GetExtra’)

        - ‘PyUnstable_Code_SetExtra()’ (rinominato da
          ‘_PyCode_SetExtra’)

     I nomi originali continueranno a essere disponibili fino alla
     rispettiva modifica dell’API.

     (Contribuito da Petr Viktorin in gh-101101(3).)

   * PEP 697(4): Aggiunta un’API per estendere i tipi la cui struttura
     di memoria delle istanze è opaca:

        - *note PyType_Spec.basicsize: 76b. può essere zero o negativo
          per specificare l’ereditarietà o l’estensione della dimensione
          della classe base.

        - *note PyObject_GetTypeData(): 76c. e *note
          PyType_GetTypeDataSize(): 76d. aggiunti per consentire
          l’accesso ai dati di istanza specifici della sottoclasse.

        - *note Py_TPFLAGS_ITEMS_AT_END: 76e. e *note
          PyObject_GetItemData(): 76f. aggiunti per consentire
          l’estensione sicura di determinati tipi a dimensione
          variabile, incluso *note PyType_Type: 770.

        - *note Py_RELATIVE_OFFSET: 771. aggiunto per consentire la
          definizione di *note membri: 772. in termini di una struttura
          specifica della sottoclasse.

     (Contribuito da Petr Viktorin in gh-103509(5).)

   * Aggiunta la nuova funzione della *note limited C API: 637. *note
     PyType_FromMetaclass(): 773, che generalizza l’esistente *note
     PyType_FromModuleAndSpec(): 774. utilizzando un argomento
     metaclasse aggiuntivo.  (Contribuito da Wenzel Jakob in
     gh-93012(6).)

   * È stata aggiunta un’API per creare oggetti che possono essere
     chiamati utilizzando *note il protocollo vectorcall: 775. alla
     *note Limited API: 776.:

        * *note Py_TPFLAGS_HAVE_VECTORCALL: 777.

        * *note PyVectorcall_NARGS(): 778.

        * *note PyVectorcall_Call(): 779.

        * *note vectorcallfunc: 77a.

     Il flag *note Py_TPFLAGS_HAVE_VECTORCALL: 777. viene ora rimosso da
     una classe quando il metodo della classe *note __call__(): 77b.
     viene riassegnato.  Questo rende sicuro l’uso di vectorcall con
     tipi mutabili (cioè tipi di heap senza il flag immutabile, *note
     Py_TPFLAGS_IMMUTABLETYPE: 3cf.).  I tipi mutabili che non
     sovrascrivono *note tp_call: 77c. ora ereditano il flag
     ‘Py_TPFLAGS_HAVE_VECTORCALL’.  (Contributo di Petr Viktorin in
     gh-93274(7).)

     The *note Py_TPFLAGS_MANAGED_DICT: 60f. and *note
     Py_TPFLAGS_MANAGED_WEAKREF: 77d. flags have been added.  This
     allows extensions classes to support object *note __dict__: 77e.
     and weakrefs with less bookkeeping, using less memory and with
     faster access.

   * È stata aggiunta all” *note Limited API: 776. l’API per eseguire
     chiamate utilizzando *note il protocollo vectorcall: 775.:

        * *note PyObject_Vectorcall(): 77f.

        * *note PyObject_VectorcallMethod(): 780.

        * *note PY_VECTORCALL_ARGUMENTS_OFFSET: 781.

     Questo significa che entrambe le estremità, in entrata e in uscita,
     del protocollo vectorcall sono ora disponibili nella *note Limited
     API: 776.  (Contributo di Wenzel Jakob in gh-98586(8).)

   * Aggiunte due nuove funzioni pubbliche, *note
     PyEval_SetProfileAllThreads(): 782. e *note
     PyEval_SetTraceAllThreads(): 664, che permettono di impostare
     funzioni di tracciamento e profilazione in tutti i thread in
     esecuzione oltre a quello chiamante.  (Contributo di Pablo Galindo
     in gh-93503(9).)

   * Aggiunta la nuova funzione *note PyFunction_SetVectorcall(): 783.
     alla C API che imposta il campo vectorcall di un dato *note
     PyFunctionObject: 784.  (Contributo di Andrew Frost in
     gh-92257(10).)

   * La C API ora consente di registrare callback tramite *note
     PyDict_AddWatcher(): 3d0, *note PyDict_Watch(): 785. e API
     correlate che vengono chiamate ogni volta che un dizionario viene
     modificato.  Questo è inteso per l’uso da parte di interpreti
     ottimizzanti, compilatori JIT o debugger.  (Contributo di Carl
     Meyer in gh-91052(11).)

   * Aggiunte le API *note PyType_AddWatcher(): 786. e *note
     PyType_Watch(): 787. per registrare callback che ricevono notifiche
     sulle modifiche a un tipo.  (Contributo di Carl Meyer in
     gh-91051(12).)

   * Aggiunte le API *note PyCode_AddWatcher(): 788. e *note
     PyCode_ClearWatcher(): 789. per registrare callback che ricevono
     notifiche sulla creazione e distruzione di oggetti di codice.
     (Contributo di Itamar Oren in gh-91054(13).)

   * Aggiunte le funzioni *note PyFrame_GetVar(): 78a. e *note
     PyFrame_GetVarString(): 78b. per ottenere una variabile di frame
     per nome.  (Contributo di Victor Stinner in gh-91248(14).)

   * Aggiunte *note PyErr_GetRaisedException(): 429. e *note
     PyErr_SetRaisedException(): 42c. per salvare e ripristinare
     l’eccezione corrente.  Queste funzioni restituiscono e accettano un
     singolo oggetto eccezione, anziché i tre argomenti della ormai
     deprecata *note PyErr_Fetch(): 428. e *note PyErr_Restore(): 42b.
     Questo è meno soggetto a errori e un po” più efficiente.
     (Contributo di Mark Shannon in gh-101578(15).)

   * Aggiunto ‘_PyErr_ChainExceptions1’, che accetta un’istanza di
     eccezione, per sostituire l’API legacy ‘_PyErr_ChainExceptions’,
     che ora è deprecata.  (Contributo di Mark Shannon in
     gh-101578(16).)

   * Aggiunte *note PyException_GetArgs(): 78c. e *note
     PyException_SetArgs(): 78d. come funzioni di comodo per recuperare
     e modificare gli *note args: 78e. passati al costruttore
     dell’eccezione.  (Contributo di Mark Shannon in gh-101578(17).)

   * Aggiunta *note PyErr_DisplayException(): 435, che accetta
     un’istanza di eccezione, per sostituire l’API legacy
     ‘PyErr_Display()’.  (Contributo di Irit Katriel in gh-102755(18)).

   * PEP 683(19): Introdurre 'Immortal Objects', che consente agli
     oggetti di bypassare i conti di riferimento, e modifiche correlate
     alla C-API:

        - 
          ‘_Py_IMMORTAL_REFCNT’: Il conteggio dei riferimenti che definisce un oggetto

               come immortale.

        - ‘_Py_IsImmortal’ Controlla se un oggetto ha il conteggio dei
          riferimenti immortali.

        - 
          ‘PyObject_HEAD_INIT’ Ora inizializzerà il conteggio dei riferimenti a

               ‘SSTATE_INTERNED_IMMORTAL’ Un identificatore per oggetti
               Unicode internati

        - 
          ‘SSTATE_INTERNED_IMMORTAL’ An identifier for interned unicode objects

               che sono immortali.

        - 
          ‘SSTATE_INTERNED_IMMORTAL_STATIC’ Un identificatore per oggetti Unicode internati

               ‘sys.getunicodeinternedsize’ Restituisce il numero totale
               di oggetti Unicode

        - 
          ‘sys.getunicodeinternedsize’ This returns the total number of unicode

               che sono stati internati.  Questo è ora necessario per
               ‘refleak.py’ per monitorare correttamente i conti di
               riferimenti e i blocchi allocati.

     (Contributo di Eddie Elizondo in gh-84436(20).)

   * PEP 684(21): Aggiunta la nuova funzione *note
     Py_NewInterpreterFromConfig(): 68a. e *note PyInterpreterConfig:
     78f, che possono essere utilizzate per creare sotto-interpreti con
     i propri GIL. (Vedi *note PEP 684; Un GIL per interprete: 670. per
     maggiori informazioni.)  (Contributo di Eric Snow in
     gh-104110(22).)

   * Nella versione 3.12 della limited C API, le funzioni *note
     Py_INCREF(): 790. e *note Py_DECREF(): 791. sono ora implementate
     come chiamate di funzione opache per nascondere i dettagli
     dell’implementazione.  (Contributo di Victor Stinner in
     gh-105387(23).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0697/

   (2) https://peps.python.org/pep-0523/

   (3) https://github.com/python/cpython/issues/101101

   (4) https://peps.python.org/pep-0697/

   (5) https://github.com/python/cpython/issues/103509

   (6) https://github.com/python/cpython/issues/93012

   (7) https://github.com/python/cpython/issues/93274

   (8) https://github.com/python/cpython/issues/98586

   (9) https://github.com/python/cpython/issues/93503

   (10) https://github.com/python/cpython/issues/92257

   (11) https://github.com/python/cpython/issues/91052

   (12) https://github.com/python/cpython/issues/91051

   (13) https://github.com/python/cpython/issues/91054

   (14) https://github.com/python/cpython/issues/91248

   (15) https://github.com/python/cpython/issues/101578

   (16) https://github.com/python/cpython/issues/101578

   (17) https://github.com/python/cpython/issues/101578

   (18) https://github.com/python/cpython/issues/102755

   (19) https://peps.python.org/pep-0683/

   (20) https://github.com/python/cpython/issues/84436

   (21) https://peps.python.org/pep-0684/

   (22) https://github.com/python/cpython/issues/104110

   (23) https://github.com/python/cpython/issues/105387


File: python.info,  Node: Porting a Python 3 12<2>,  Next: Deprecato<2>,  Prev: Nuove Funzionalità<2>,  Up: Modifiche all’API C

1.3.14.2 Porting a Python 3.12
..............................

   * Le API Unicode legacy basate sulla rappresentazione ‘Py_UNICODE*’
     sono state rimosse.  Si prega di migrare alle API basate su UTF-8 o
     ‘wchar_t*’.

   * Le funzioni di analisi degli argomenti come *note
     PyArg_ParseTuple(): 3c1. non supportano più i formati basati su
     ‘Py_UNICODE*’ (ad esempio ‘u’, ‘Z’).  Si prega di migrare ad altri
     formati per Unicode come ‘s’, ‘z’, ‘es’ e ‘U’.

   * ‘tp_weaklist’ per tutti i tipi built-in statici è sempre ‘NULL’.
     Questo è un campo solo interno su ‘PyTypeObject’, ma segnaliamo la
     modifica nel caso qualcuno lo stia accedendo direttamente.  Per
     evitare interruzioni, si consiglia di utilizzare invece la C-API
     pubblica esistente o, se necessario, la macro (solo interna)
     ‘_PyObject_GET_WEAKREFS_LISTPTR()’.

   * Questo campo solo interno *note PyTypeObject.tp_subclasses: 793.
     potrebbe ora non essere un puntatore a oggetto valido.  Il suo tipo
     è stato cambiato in void* per riflettere questo.  Menzioniamo
     questa modifica nel caso qualcuno stia accedendo direttamente al
     campo solo interno.

     To get a list of subclasses, call the Python method *note
     __subclasses__(): 794. (using *note PyObject_CallMethod(): 640, for
     example).

   * Aggiunto supporto per più opzioni di formattazione (allineamento a
     sinistra, ottali, esadecimali maiuscoli, ‘intmax_t’, ‘ptrdiff_t’,
     stringhe C ‘wchar_t’, larghezza e precisione variabili) in *note
     PyUnicode_FromFormat(): 62b. e *note PyUnicode_FromFormatV(): 795.
     (Contributo di Serhiy Storchaka in gh-98836(1).)

   * Un carattere di formato non riconosciuto in *note
     PyUnicode_FromFormat(): 62b. e *note PyUnicode_FromFormatV(): 795.
     ora imposta una *note SystemError: 796.  Nelle versioni precedenti,
     causava la copia invariata del resto della stringa di formato nella
     stringa di risultato e scartava eventuali argomenti extra.
     (Contributo di Serhiy Storchaka in gh-95781(2).)

   * Corretta la posizione errata del segno in *note
     PyUnicode_FromFormat(): 62b. e *note PyUnicode_FromFormatV(): 795.
     (Contributo di Philip Georgi in gh-95504(3).)

   * Extension classes wanting to add a *note __dict__: 77e. or weak
     reference slot should use *note Py_TPFLAGS_MANAGED_DICT: 60f. and
     *note Py_TPFLAGS_MANAGED_WEAKREF: 77d. instead of ‘tp_dictoffset’
     and ‘tp_weaklistoffset’, respectively.  The use of ‘tp_dictoffset’
     and ‘tp_weaklistoffset’ is still supported, but does not fully
     support multiple inheritance (gh-95589(4)), and performance may be
     worse.  Classes declaring *note Py_TPFLAGS_MANAGED_DICT: 60f. must
     call ‘_PyObject_VisitManagedDict()’ and
     ‘_PyObject_ClearManagedDict()’ to traverse and clear their
     instance’s dictionaries.  To clear weakrefs, call *note
     PyObject_ClearWeakRefs(): 797, as before.

   * La funzione *note PyUnicode_FSDecoder(): 798. non accetta più
     percorsi simili a byte, come *note bytearray: 344. e tipi *note
     memoryview: 165.: solo il tipo esatto *note bytes: 192. è accettato
     per le stringhe di byte.  (Contributo di Victor Stinner in
     gh-98393(5).)

   * Le macro *note Py_CLEAR: 799, *note Py_SETREF: 79a. e *note
     Py_XSETREF: 79b. ora valutano i loro argomenti solo una volta.  Se
     un argomento ha effetti collaterali, questi effetti collaterali non
     vengono più duplicati.  (Contributo di Victor Stinner in
     gh-98724(6).)

   * L’indicatore di errore dell’interprete è ora sempre normalizzato.
     Questo significa che *note PyErr_SetObject(): 79c, *note
     PyErr_SetString(): 79d. e le altre funzioni che impostano
     l’indicatore di errore ora normalizzano l’eccezione prima di
     memorizzarla.  (Contributo di Mark Shannon in gh-101578(7).)

   * ‘_Py_RefTotal’ non è più autorevole e viene mantenuto solo per la
     compatibilità ABI. Nota che è una globale interna e disponibile
     solo build di debug.  Se stai usando questa variabile, dovrai
     iniziare a usare ‘_Py_GetGlobalRefTotal()’.

   * Le seguenti funzioni ora selezionano una metaclasse appropriata per
     il tipo appena creato:

        * *note PyType_FromSpec(): 79e.

        * *note PyType_FromSpecWithBases(): 79f.

        * *note PyType_FromModuleAndSpec(): 774.

     Creare classi la cui metaclasse sovrascrive *note tp_new: 7a0. è
     deprecato e in Python 3.14+ sarà disabilitato.  Nota che queste
     funzioni ignorano ‘tp_new’ della metaclasse, possibilmente
     permettendo un’inizializzazione incompleta.

     Nota che *note PyType_FromMetaclass(): 773. (aggiunto in Python
     3.12) già impedisce la creazione di classi la cui metaclasse
     sovrascrive ‘tp_new’ (*note __new__(): 7a1. in Python).

     Poiché ‘tp_new’ sovrascrive quasi tutto ciò che fanno le funzioni
     ‘PyType_From*’, i due sono incompatibili tra loro.  Il
     comportamento esistente — ignorare la metaclasse per diversi
     passaggi della creazione del tipo — è generalmente insicuro, poiché
     (meta)classi assumono che ‘tp_new’ sia stato chiamato.  Non esiste
     una soluzione generale semplice.  Una delle seguenti opzioni
     potrebbe funzionare per te:

        - Se controlli la metaclasse, evita di usare ‘tp_new’ in essa:

             - Se l’inizializzazione può essere saltata, può essere
               fatta al contrario in *note tp_init: 7a2.

             - Se la metaclasse non ha bisogno di essere istanziata da
               Python, imposta il suo ‘tp_new’ su ‘NULL’ utilizzando il
               flag *note Py_TPFLAGS_DISALLOW_INSTANTIATION: 7a3.  Ciò
               la rende accettabile per le funzioni ‘PyType_From*’.

        - Evita le funzioni ‘PyType_From*’: se non ti servono
          funzionalità specifiche di C (slot o impostazione della
          dimensione dell’istanza), crea tipi tramite la *note chiamata:
          7a4. della metaclasse.

        - Se 'sai' che ‘tp_new’ può essere saltato in sicurezza, filtra
          l’avviso di deprecazione usando *note
          warnings.catch_warnings(): 179. da Python.

   * *note PyOS_InputHook: 7a5. e *note PyOS_ReadlineFunctionPointer:
     7a6. non vengono più chiamati in *note subinterpreters: 163.
     Questo perché i client generalmente si affidano allo stato globale
     del processo (poiché questi callback non hanno modo di recuperare
     lo stato del modulo di estensione).

     Questo evita anche situazioni in cui le estensioni potrebbero
     trovarsi in esecuzione in un subinterprete che non supportano (o
     non sono ancora state caricate in).  Vedi gh-104668(8) per
     ulteriori informazioni.

   * *note PyLongObject: 39e. ha avuto i suoi interni cambiati per
     migliorare le prestazioni.  Sebbene gli interni di *note
     PyLongObject: 39e. siano privati, vengono utilizzati da alcuni
     moduli di estensione.  I campi interni non devono più essere
     acceduti direttamente, ma devono essere utilizzate le funzioni API
     che iniziano con ‘PyLong_...’.  Vengono fornite due nuove funzioni
     API 'instabili' per un accesso efficiente al valore dei *note
     PyLongObject: 39e.s che rientrano in una sola parola macchina:

        * *note PyUnstable_Long_IsCompact(): 7a7.

        * *note PyUnstable_Long_CompactValue(): 7a8.

   * Gli allocatori personalizzati, impostati tramite *note
     PyMem_SetAllocator(): 7a9, sono ora richiesti per essere
     thread-safe, indipendentemente dal dominio di memoria.  Gli
     allocatori che non hanno uno stato proprio, compresi i «ganci», non
     sono interessati.  Se il tuo allocatore personalizzato non è già
     thread-safe e hai bisogno di assistenza, crea un nuovo problema su
     GitHub e CC ‘@ericsnowcurrently’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98836

   (2) https://github.com/python/cpython/issues/95781

   (3) https://github.com/python/cpython/issues/95504

   (4) https://github.com/python/cpython/issues/95589

   (5) https://github.com/python/cpython/issues/98393

   (6) https://github.com/python/cpython/issues/98724

   (7) https://github.com/python/cpython/issues/101578

   (8) https://github.com/python/cpython/issues/104668


File: python.info,  Node: Deprecato<2>,  Next: Rimosso<2>,  Prev: Porting a Python 3 12<2>,  Up: Modifiche all’API C

1.3.14.3 Deprecato
..................

   * In conformità con PEP 699(1), il campo ‘ma_version_tag’ in *note
     PyDictObject: 64f. è deprecato per i moduli di estensione.
     L’accesso a questo campo genererà un avviso del compilatore al
     momento della compilazione.  Questo campo sarà rimosso in Python
     3.14.  (Contribuito da Ramvikrams e Kumar Aditya in gh-101193(2).
     PEP di Ken Jin.)

   * Deprecare la variabile di configurazione globale:

        * *note Py_DebugFlag: 3f8.: usa *note PyConfig.parser_debug:
          3f9.

        * *note Py_VerboseFlag: 3fa.: usa *note PyConfig.verbose: 3fb.

        * *note Py_QuietFlag: 3fc.: usa *note PyConfig.quiet: 3fd.

        * *note Py_InteractiveFlag: 3fe.: usa *note
          PyConfig.interactive: 3ff.

        * *note Py_InspectFlag: 400.: usa *note PyConfig.inspect: 401.

        * *note Py_OptimizeFlag: 402.: usa *note
          PyConfig.optimization_level: 403.

        * *note Py_NoSiteFlag: 404.: usa *note PyConfig.site_import:
          405.

        * *note Py_BytesWarningFlag: 406.: usa *note
          PyConfig.bytes_warning: 407.

        * *note Py_FrozenFlag: 408.: usa *note
          PyConfig.pathconfig_warnings: 409.

        * *note Py_IgnoreEnvironmentFlag: 40a.: usa *note
          PyConfig.use_environment: 40b.

        * *note Py_DontWriteBytecodeFlag: 40c.: usa *note
          PyConfig.write_bytecode: 40d.

        * *note Py_NoUserSiteDirectory: 40e.: usa *note
          PyConfig.user_site_directory: 40f.

        * *note Py_UnbufferedStdioFlag: 410.: usa *note
          PyConfig.buffered_stdio: 411.

        * *note Py_HashRandomizationFlag: 412.: usa *note
          PyConfig.use_hash_seed: 413. e *note PyConfig.hash_seed: 414.

        * *note Py_IsolatedFlag: 415.: usa *note PyConfig.isolated: 416.

        * *note Py_LegacyWindowsFSEncodingFlag: 417.: usa *note
          PyPreConfig.legacy_windows_fs_encoding: 418.

        * *note Py_LegacyWindowsStdioFlag: 419.: usa *note
          PyConfig.legacy_windows_stdio: 41a.

        * ‘Py_FileSystemDefaultEncoding’: usa *note
          PyConfig.filesystem_encoding: 41b.

        * ‘Py_HasFileSystemDefaultEncoding’: usa *note
          PyConfig.filesystem_encoding: 41b.

        * ‘Py_FileSystemDefaultEncodeErrors’: usa *note
          PyConfig.filesystem_errors: 41c.

        * ‘Py_UTF8Mode’: usa *note PyPreConfig.utf8_mode: 41d. (vedi
          *note Py_PreInitialize(): 41e.)

     L’API *note Py_InitializeFromConfig(): 3f6. dovrebbe essere usata
     con *note PyConfig: 3f7. invece.  (Contribuito da Victor Stinner in
     gh-77782(3).)

   * Creare *note tipi immutabili: 3cf. con basi mutabili è deprecato e
     verrà disabilitato in Python 3.14.  (gh-95388(4))

   * L’intestazione ‘structmember.h’ è deprecata, sebbene continui a
     essere disponibile e non ci siano piani per rimuoverla.

     I suoi contenuti sono ora disponibili semplicemente includendo
     ‘Python.h’, con un prefisso ‘Py’ aggiunto se mancava:

        - *note PyMemberDef: 772, *note PyMember_GetOne(): 7ab. e *note
          PyMember_SetOne(): 7ac.

        - Macro di tipo come *note Py_T_INT: 7ad, *note Py_T_DOUBLE:
          7ae, ecc.  (precedentemente ‘T_INT’, ‘T_DOUBLE’, ecc.)

        - Le bandiere *note Py_READONLY: 7af. (precedentemente
          ‘READONLY’) e *note Py_AUDIT_READ: 7b0. (precedentemente tutte
          maiuscole)

     Diversi elementi non sono esposti da ‘Python.h’:

        - *note T_OBJECT: 7b1. (usa *note Py_T_OBJECT_EX: 7b2.)

        - *note T_NONE: 7b3. (precedentemente non documentato, e
          piuttosto strano)

        - La macro ‘WRITE_RESTRICTED’ che non fa nulla.

        - Le macro ‘RESTRICTED’ e ‘READ_RESTRICTED’, equivalenti di
          *note Py_AUDIT_READ: 7b0.

        - In alcune configurazioni, ‘<stddef.h>’ non è incluso da
          ‘Python.h’.  Va incluso manualmente quando si utilizza
          ‘offsetof()’.

     L’header deprecato continua a fornire i suoi contenuti originali
     sotto i nomi originali.  Il tuo vecchio codice può rimanere
     invariato, a meno che l’inclusione extra e le macro non spaziati ti
     diano molto fastidio.

     (Contribuito in gh-47146(5) da Petr Viktorin, basato su lavori
     precedenti di Alexander Belopolsky e Matthias Braun.)

   * *note PyErr_Fetch(): 428. e *note PyErr_Restore(): 42b. sono
     deprecate.  Usa *note PyErr_GetRaisedException(): 429. e *note
     PyErr_SetRaisedException(): 42c. invece.  (Contribuito da Mark
     Shannon in gh-101578(6).)

   * ‘PyErr_Display()’ è deprecata.  Usa *note PyErr_DisplayException():
     435. invece.  (Contribuito da Irit Katriel in gh-102755(7)).

   * ‘_PyErr_ChainExceptions’ è deprecata.  Usa
     ‘_PyErr_ChainExceptions1’ invece.  (Contribuito da Irit Katriel in
     gh-102192(8).)

   * Usare *note PyType_FromSpec(): 79e, *note
     PyType_FromSpecWithBases(): 79f. o *note
     PyType_FromModuleAndSpec(): 774. per creare una classe la cui
     metaclasse sovrascrive *note tp_new: 7a0. è deprecato.  Chiama
     direttamente la metaclasse invece.

* Menu:

* Pending removal in Python 3.14: Pending removal in Python 3 14<4>.
* Pending removal in Python 3.15: Pending removal in Python 3 15<6>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<6>.
* Pending removal in future versions: Pending removal in future versions<6>.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0699/

   (2) https://github.com/python/cpython/issues/101193

   (3) https://github.com/python/cpython/issues/77782

   (4) https://github.com/python/cpython/issues/95388

   (5) https://github.com/python/cpython/issues/47146

   (6) https://github.com/python/cpython/issues/101578

   (7) https://github.com/python/cpython/issues/102755

   (8) https://github.com/python/cpython/issues/102192


File: python.info,  Node: Pending removal in Python 3 14<4>,  Next: Pending removal in Python 3 15<6>,  Up: Deprecato<2>

1.3.14.4 Pending removal in Python 3.14
.......................................

   * Il campo ‘ma_version_tag’ in *note PyDictObject: 64f. per moduli di
     estensione ( PEP 699(1); gh-101193(2)).

   * Creare *note tipi immutabili: 3cf. con basi mutabili (gh-95388(3)).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0699/

   (2) https://github.com/python/cpython/issues/101193

   (3) https://github.com/python/cpython/issues/95388


File: python.info,  Node: Pending removal in Python 3 15<6>,  Next: Pending removal in Python 3 16<6>,  Prev: Pending removal in Python 3 14<4>,  Up: Deprecato<2>

1.3.14.5 Pending removal in Python 3.15
.......................................

   * The *note PyImport_ImportModuleNoBlock(): 3db.: Use *note
     PyImport_ImportModule(): 3dc. instead.

   * *note PyWeakref_GetObject(): 3dd. and *note PyWeakref_GET_OBJECT():
     3de.: Use *note PyWeakref_GetRef(): 3df. instead.  The
     pythoncapi-compat project(1) can be used to get *note
     PyWeakref_GetRef(): 3df. on Python 3.12 and older.

   * *note Py_UNICODE: 3e0. type and the ‘Py_UNICODE_WIDE’ macro: Use
     ‘wchar_t’ instead.

   * ‘PyUnicode_AsDecodedObject()’: Use *note PyCodec_Decode(): 3e1.
     instead.

   * ‘PyUnicode_AsDecodedUnicode()’: Use *note PyCodec_Decode(): 3e1.
     instead; Note that some codecs (for example, «base64») may return a
     type other than *note str: 169, such as *note bytes: 192.

   * ‘PyUnicode_AsEncodedObject()’: Use *note PyCodec_Encode(): 3e2.
     instead.

   * ‘PyUnicode_AsEncodedUnicode()’: Use *note PyCodec_Encode(): 3e2.
     instead; Note that some codecs (for example, «base64») may return a
     type other than *note bytes: 192, such as *note str: 169.

   * Python initialization functions, deprecated in Python 3.13:

        * *note Py_GetPath(): 3e3.: Use *note
          PyConfig_Get("module_search_paths"): 37c. (*note sys.path:
          3e4.) instead.

        * *note Py_GetPrefix(): 3e5.: Use *note
          PyConfig_Get("base_prefix"): 37c. (*note sys.base_prefix:
          3e6.) instead.  Use *note PyConfig_Get("prefix"): 37c. (*note
          sys.prefix: 3e7.) if *note virtual environments: 3e8. need to
          be handled.

        * *note Py_GetExecPrefix(): 3e9.: Use *note
          PyConfig_Get("base_exec_prefix"): 37c. (*note
          sys.base_exec_prefix: 3ea.) instead.  Use *note
          PyConfig_Get("exec_prefix"): 37c. (*note sys.exec_prefix:
          3eb.) if *note virtual environments: 3e8. need to be handled.

        * *note Py_GetProgramFullPath(): 3ec.: Use *note
          PyConfig_Get("executable"): 37c. (*note sys.executable: 3ed.)
          instead.

        * *note Py_GetProgramName(): 3ee.: Use *note
          PyConfig_Get("executable"): 37c. (*note sys.executable: 3ed.)
          instead.

        * *note Py_GetPythonHome(): 3ef.: Use *note
          PyConfig_Get("home"): 37c. or the *note PYTHONHOME: 3f0.
          environment variable instead.

     The pythoncapi-compat project(2) can be used to get *note
     PyConfig_Get(): 37c. on Python 3.13 and older.

   * Functions to configure Python’s initialization, deprecated in
     Python 3.11:

        * ‘PySys_SetArgvEx()’: Set *note PyConfig.argv: 3f1. instead.

        * ‘PySys_SetArgv()’: Set *note PyConfig.argv: 3f1. instead.

        * ‘Py_SetProgramName()’: Set *note PyConfig.program_name: 3f2.
          instead.

        * ‘Py_SetPythonHome()’: Set *note PyConfig.home: 3f3. instead.

        * *note PySys_ResetWarnOptions(): 3f4.: Clear *note
          sys.warnoptions: 3f5. and ‘warnings.filters’ instead.

     L’API *note Py_InitializeFromConfig(): 3f6. dovrebbe essere usata
     con *note PyConfig: 3f7.

   * Variabili di configurazione globali:

        * *note Py_DebugFlag: 3f8.: Use *note PyConfig.parser_debug:
          3f9. or *note PyConfig_Get("parser_debug"): 37c. instead.

        * *note Py_VerboseFlag: 3fa.: Use *note PyConfig.verbose: 3fb.
          or *note PyConfig_Get("verbose"): 37c. instead.

        * *note Py_QuietFlag: 3fc.: Use *note PyConfig.quiet: 3fd. or
          *note PyConfig_Get("quiet"): 37c. instead.

        * *note Py_InteractiveFlag: 3fe.: Use *note
          PyConfig.interactive: 3ff. or *note
          PyConfig_Get("interactive"): 37c. instead.

        * *note Py_InspectFlag: 400.: Use *note PyConfig.inspect: 401.
          or *note PyConfig_Get("inspect"): 37c. instead.

        * *note Py_OptimizeFlag: 402.: Use *note
          PyConfig.optimization_level: 403. or *note
          PyConfig_Get("optimization_level"): 37c. instead.

        * *note Py_NoSiteFlag: 404.: Use *note PyConfig.site_import:
          405. or *note PyConfig_Get("site_import"): 37c. instead.

        * *note Py_BytesWarningFlag: 406.: Use *note
          PyConfig.bytes_warning: 407. or *note
          PyConfig_Get("bytes_warning"): 37c. instead.

        * *note Py_FrozenFlag: 408.: Use *note
          PyConfig.pathconfig_warnings: 409. or *note
          PyConfig_Get("pathconfig_warnings"): 37c. instead.

        * *note Py_IgnoreEnvironmentFlag: 40a.: Use *note
          PyConfig.use_environment: 40b. or *note
          PyConfig_Get("use_environment"): 37c. instead.

        * *note Py_DontWriteBytecodeFlag: 40c.: Use *note
          PyConfig.write_bytecode: 40d. or *note
          PyConfig_Get("write_bytecode"): 37c. instead.

        * *note Py_NoUserSiteDirectory: 40e.: Use *note
          PyConfig.user_site_directory: 40f. or *note
          PyConfig_Get("user_site_directory"): 37c. instead.

        * *note Py_UnbufferedStdioFlag: 410.: Use *note
          PyConfig.buffered_stdio: 411. or *note
          PyConfig_Get("buffered_stdio"): 37c. instead.

        * *note Py_HashRandomizationFlag: 412.: Use *note
          PyConfig.use_hash_seed: 413. and *note PyConfig.hash_seed:
          414. or *note PyConfig_Get("hash_seed"): 37c. instead.

        * *note Py_IsolatedFlag: 415.: Use *note PyConfig.isolated: 416.
          or *note PyConfig_Get("isolated"): 37c. instead.

        * *note Py_LegacyWindowsFSEncodingFlag: 417.: Use *note
          PyPreConfig.legacy_windows_fs_encoding: 418. or *note
          PyConfig_Get("legacy_windows_fs_encoding"): 37c. instead.

        * *note Py_LegacyWindowsStdioFlag: 419.: Use *note
          PyConfig.legacy_windows_stdio: 41a. or *note
          PyConfig_Get("legacy_windows_stdio"): 37c. instead.

        * ‘Py_FileSystemDefaultEncoding’,
          ‘Py_HasFileSystemDefaultEncoding’: Use *note
          PyConfig.filesystem_encoding: 41b. or *note
          PyConfig_Get("filesystem_encoding"): 37c. instead.

        * ‘Py_FileSystemDefaultEncodeErrors’: Use *note
          PyConfig.filesystem_errors: 41c. or *note
          PyConfig_Get("filesystem_errors"): 37c. instead.

        * ‘Py_UTF8Mode’: Use *note PyPreConfig.utf8_mode: 41d. or *note
          PyConfig_Get("utf8_mode"): 37c. instead.  (see *note
          Py_PreInitialize(): 41e.)

     The *note Py_InitializeFromConfig(): 3f6. API should be used with
     *note PyConfig: 3f7. to set these options.  Or *note
     PyConfig_Get(): 37c. can be used to get these options at runtime.

   ---------- Footnotes ----------

   (1) https://github.com/python/pythoncapi-compat/

   (2) https://github.com/python/pythoncapi-compat/


File: python.info,  Node: Pending removal in Python 3 16<6>,  Next: Pending removal in future versions<6>,  Prev: Pending removal in Python 3 15<6>,  Up: Deprecato<2>

1.3.14.6 Pending removal in Python 3.16
.......................................

   * The bundled copy of ‘libmpdec’.


File: python.info,  Node: Pending removal in future versions<6>,  Prev: Pending removal in Python 3 16<6>,  Up: Deprecato<2>

1.3.14.7 Pending removal in future versions
...........................................

Le seguenti API sono deprecate e verranno rimosse, anche se attualmente
non è prevista una data di rimozione.

   * *note Py_TPFLAGS_HAVE_FINALIZE: 427.: Unneeded since Python 3.8.

   * *note PyErr_Fetch(): 428.: Use *note PyErr_GetRaisedException():
     429. instead.

   * *note PyErr_NormalizeException(): 42a.: Use *note
     PyErr_GetRaisedException(): 429. instead.

   * *note PyErr_Restore(): 42b.: Use *note PyErr_SetRaisedException():
     42c. instead.

   * *note PyModule_GetFilename(): 42d.: Use *note
     PyModule_GetFilenameObject(): 42e. instead.

   * *note PyOS_AfterFork(): 42f.: Use *note PyOS_AfterFork_Child():
     430. instead.

   * *note PySlice_GetIndicesEx(): 431.: Use *note PySlice_Unpack():
     432. and *note PySlice_AdjustIndices(): 433. instead.

   * *note PyUnicode_READY(): 434.: Unneeded since Python 3.12

   * ‘PyErr_Display()’: Use *note PyErr_DisplayException(): 435.
     instead.

   * ‘_PyErr_ChainExceptions()’: Use ‘_PyErr_ChainExceptions1()’
     instead.

   * ‘PyBytesObject.ob_shash’ member: call *note PyObject_Hash(): 436.
     instead.

   * API del Thread Local Storage (TLS):

        * *note PyThread_create_key(): 437.: Use *note
          PyThread_tss_alloc(): 438. instead.

        * *note PyThread_delete_key(): 439.: Use *note
          PyThread_tss_free(): 43a. instead.

        * *note PyThread_set_key_value(): 43b.: Use *note
          PyThread_tss_set(): 43c. instead.

        * *note PyThread_get_key_value(): 43d.: Use *note
          PyThread_tss_get(): 43e. instead.

        * *note PyThread_delete_key_value(): 43f.: Use *note
          PyThread_tss_delete(): 440. instead.

        * *note PyThread_ReInitTLS(): 441.: Unneeded since Python 3.7.


File: python.info,  Node: Rimosso<2>,  Prev: Deprecato<2>,  Up: Modifiche all’API C

1.3.14.8 Rimosso
................

   * Rimuovi il file di intestazione ‘token.h’.  Non c’è mai stata
     un’API pubblica per il tokenizer C. Il file di intestazione
     ‘token.h’ è stato progettato solo per essere usato dagli interni di
     Python.  (Contribuito da Victor Stinner in gh-92651(1).)

   * Le API Unicode legacy sono state rimosse.  Vedi PEP 623(2) per i
     dettagli.

        * ‘PyUnicode_WCHAR_KIND’

        * ‘PyUnicode_AS_UNICODE()’

        * ‘PyUnicode_AsUnicode()’

        * ‘PyUnicode_AsUnicodeAndSize()’

        * ‘PyUnicode_AS_DATA()’

        * ‘PyUnicode_FromUnicode()’

        * ‘PyUnicode_GET_SIZE()’

        * ‘PyUnicode_GetSize()’

        * ‘PyUnicode_GET_DATA_SIZE()’

   * Remove the ‘PyUnicode_InternImmortal()’ function macro.
     (Contributed by Victor Stinner in gh-85858(3).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/92651

   (2) https://peps.python.org/pep-0623/

   (3) https://github.com/python/cpython/issues/85858


File: python.info,  Node: What’s New In Python 3 11,  Next: What’s New In Python 3 10,  Prev: Novità in Python 3 12,  Up: Novità in Python

1.4 What’s New In Python 3.11
=============================


Editor: Pablo Galindo Salgado

This article explains the new features in Python 3.11, compared to 3.10.
Python 3.11 was released on October 24, 2022.  For full details, see the
*note changelog: 142.

* Menu:

* Summary – Release highlights: Summary – Release highlights<2>.
* New Features: New Features<3>.
* New Features Related to Type Hints::
* Other Language Changes: Other Language Changes<2>.
* Other CPython Implementation Changes::
* New Modules: New Modules<2>.
* Improved Modules: Improved Modules<2>.
* Optimizations: Optimizations<3>.
* Faster CPython::
* CPython bytecode changes: CPython bytecode changes<2>.
* Deprecated: Deprecated<2>.
* Pending Removal in Python 3.12: Pending Removal in Python 3 12.
* Removed: Removed<2>.
* Porting to Python 3.11: Porting to Python 3 11.
* Build Changes: Build Changes<2>.
* C API Changes: C API Changes<2>.
* Notable changes in 3.11.4: Notable changes in 3 11 4.
* Notable changes in 3.11.5: Notable changes in 3 11 5.


File: python.info,  Node: Summary – Release highlights<2>,  Next: New Features<3>,  Up: What’s New In Python 3 11

1.4.1 Summary – Release highlights
----------------------------------

   * Python 3.11 is between 10-60% faster than Python 3.10.  On average,
     we measured a 1.25x speedup on the standard benchmark suite.  See
     *note Faster CPython: 7be. for details.

New syntax features:

   * *note PEP 654; Exception Groups and except*: 7bf.

New built-in features:

   * *note PEP 678; Exceptions can be enriched with notes: 7c0.

New standard library modules:

   * PEP 680(1): *note tomllib: 102. — Support for parsing TOML(2) in
     the Standard Library

Interpreter improvements:

   * *note PEP 657; Fine-grained error locations in tracebacks: 7c1.

   * New *note -P: 7c2. command line option and *note PYTHONSAFEPATH:
     7c3. environment variable to *note disable automatically prepending
     potentially unsafe paths: 7c4. to *note sys.path: 3e4.

New typing features:

   * *note PEP 646; Variadic generics: 7c5.

   * *note PEP 655; Marking individual TypedDict items as required or
     not-required: 7c6.

   * *note PEP 673; Self type: 7c7.

   * *note PEP 675; Arbitrary literal string type: 7c8.

   * *note PEP 681; Data class transforms: 7c9.

Important deprecations, removals and restrictions:

   * PEP 594(3): *note Many legacy standard library modules have been
     deprecated: 7ca. and will be removed in Python 3.13

   * PEP 624(4): *note Py_UNICODE encoder APIs have been removed: 7cb.

   * PEP 670(5): *note Macros converted to static inline functions: 7cc.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0680/

   (2) https://toml.io/

   (3) https://peps.python.org/pep-0594/

   (4) https://peps.python.org/pep-0624/

   (5) https://peps.python.org/pep-0670/


File: python.info,  Node: New Features<3>,  Next: New Features Related to Type Hints,  Prev: Summary – Release highlights<2>,  Up: What’s New In Python 3 11

1.4.2 New Features
------------------

* Menu:

* PEP 657; Fine-grained error locations in tracebacks: PEP 657 Fine-grained error locations in tracebacks.
* PEP 654; Exception Groups and except*: PEP 654 Exception Groups and except*.
* PEP 678; Exceptions can be enriched with notes: PEP 678 Exceptions can be enriched with notes.
* Windows py.exe launcher improvements: Windows py exe launcher improvements.


File: python.info,  Node: PEP 657 Fine-grained error locations in tracebacks,  Next: PEP 654 Exception Groups and except*,  Up: New Features<3>

1.4.2.1 PEP 657: Fine-grained error locations in tracebacks
...........................................................

When printing tracebacks, the interpreter will now point to the exact
expression that caused the error, instead of just the line.  For
example:

     Traceback (most recent call last):
       File "distance.py", line 11, in <module>
         print(manhattan_distance(p1, p2))
               ^^^^^^^^^^^^^^^^^^^^^^^^^^
       File "distance.py", line 6, in manhattan_distance
         return abs(point_1.x - point_2.x) + abs(point_1.y - point_2.y)
                                ^^^^^^^^^
     AttributeError: 'NoneType' object has no attribute 'x'

Previous versions of the interpreter would point to just the line,
making it ambiguous which object was ‘None’.  These enhanced errors can
also be helpful when dealing with deeply nested *note dict: 183. objects
and multiple function calls:

     Traceback (most recent call last):
       File "query.py", line 37, in <module>
         magic_arithmetic('foo')
       File "query.py", line 18, in magic_arithmetic
         return add_counts(x) / 25
                ^^^^^^^^^^^^^
       File "query.py", line 24, in add_counts
         return 25 + query_user(user1) + query_user(user2)
                     ^^^^^^^^^^^^^^^^^
       File "query.py", line 32, in query_user
         return 1 + query_count(db, response['a']['b']['c']['user'], retry=True)
                                    ~~~~~~~~~~~~~~~~~~^^^^^
     TypeError: 'NoneType' object is not subscriptable

As well as complex arithmetic expressions:

     Traceback (most recent call last):
       File "calculation.py", line 54, in <module>
         result = (x / y / z) * (a / b / c)
                   ~~~~~~^~~
     ZeroDivisionError: division by zero

Additionally, the information used by the enhanced traceback feature is
made available via a general API, that can be used to correlate *note
bytecode: 4ab. *note instructions: 7d0. with source code location.  This
information can be retrieved using:

   - The *note codeobject.co_positions(): 7d1. method in Python.

   - The *note PyCode_Addr2Location(): 7d2. function in the C API.

See PEP 657(1) for more details.  (Contributed by Pablo Galindo, Batuhan
Taskaya and Ammar Askar in bpo-43950(2).)

     Nota: This feature requires storing column positions in *note Code
     Objects: 7d3, which may result in a small increase in interpreter
     memory usage and disk usage for compiled Python files.  To avoid
     storing the extra information and deactivate printing the extra
     traceback information, use the *note -X no_debug_ranges: 16f.
     command line option or the *note PYTHONNODEBUGRANGES: 7d4.
     environment variable.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0657/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43950


File: python.info,  Node: PEP 654 Exception Groups and except*,  Next: PEP 678 Exceptions can be enriched with notes,  Prev: PEP 657 Fine-grained error locations in tracebacks,  Up: New Features<3>

1.4.2.2 PEP 654: Exception Groups and ‘except*’
...............................................

PEP 654(1) introduces language features that enable a program to raise
and handle multiple unrelated exceptions simultaneously.  The builtin
types *note ExceptionGroup: 4d3. and *note BaseExceptionGroup: 566. make
it possible to group exceptions and raise them together, and the new
*note except*: 1ac. syntax generalizes *note except: 1ab. to match
subgroups of exception groups.

See PEP 654(2) for more details.

(Contributed by Irit Katriel in bpo-45292(3).  PEP written by Irit
Katriel, Yury Selivanov and Guido van Rossum.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0654/

   (2) https://peps.python.org/pep-0654/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45292


File: python.info,  Node: PEP 678 Exceptions can be enriched with notes,  Next: Windows py exe launcher improvements,  Prev: PEP 654 Exception Groups and except*,  Up: New Features<3>

1.4.2.3 PEP 678: Exceptions can be enriched with notes
......................................................

The *note add_note(): 7d7. method is added to *note BaseException: 7d8.
It can be used to enrich exceptions with context information that is not
available at the time when the exception is raised.  The added notes
appear in the default traceback.

See PEP 678(1) for more details.

(Contributed by Irit Katriel in bpo-45607(2).  PEP written by Zac
Hatfield-Dodds.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0678/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45607


File: python.info,  Node: Windows py exe launcher improvements,  Prev: PEP 678 Exceptions can be enriched with notes,  Up: New Features<3>

1.4.2.4 Windows ‘py.exe’ launcher improvements
..............................................

The copy of the *note Python install manager: 7db. included with Python
3.11 has been significantly updated.  It now supports company/tag syntax
as defined in PEP 514(1) using the ‘-V:<COMPANY>/<TAG>’ argument instead
of the limited ‘-<MAJOR>.<MINOR>’.  This allows launching distributions
other than ‘PythonCore’, the one hosted on python.org(2).

When using ‘-V:’ selectors, either company or tag can be omitted, but
all installs will be searched.  For example, ‘-V:OtherPython/’ will
select the «best» tag registered for ‘OtherPython’, while ‘-V:3.11’ or
‘-V:/3.11’ will select the «best» distribution with tag ‘3.11’.

When using the legacy ‘-<MAJOR>’, ‘-<MAJOR>.<MINOR>’,
‘-<MAJOR>-<BITNESS>’ or ‘-<MAJOR>.<MINOR>-<BITNESS>’ arguments, all
existing behaviour should be preserved from past versions, and only
releases from ‘PythonCore’ will be selected.  However, the ‘-64’ suffix
now implies «not 32-bit» (not necessarily x86-64), as there are multiple
supported 64-bit platforms.  32-bit runtimes are detected by checking
the runtime’s tag for a ‘-32’ suffix.  All releases of Python since 3.5
have included this in their 32-bit builds.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0514/

   (2) https://www.python.org


File: python.info,  Node: New Features Related to Type Hints,  Next: Other Language Changes<2>,  Prev: New Features<3>,  Up: What’s New In Python 3 11

1.4.3 New Features Related to Type Hints
----------------------------------------

This section covers major changes affecting PEP 484(1) type hints and
the *note typing: 10a. module.

* Menu:

* PEP 646; Variadic generics: PEP 646 Variadic generics.
* PEP 655; Marking individual TypedDict items as required or not-required: PEP 655 Marking individual TypedDict items as required or not-required.
* PEP 673; Self type: PEP 673 Self type.
* PEP 675; Arbitrary literal string type: PEP 675 Arbitrary literal string type.
* PEP 681; Data class transforms: PEP 681 Data class transforms.
* PEP 563 may not be the future::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/


File: python.info,  Node: PEP 646 Variadic generics,  Next: PEP 655 Marking individual TypedDict items as required or not-required,  Up: New Features Related to Type Hints

1.4.3.1 PEP 646: Variadic generics
..................................

PEP 484(1) previously introduced *note TypeVar: 487, enabling creation
of generics parameterised with a single type.  PEP 646(2) adds *note
TypeVarTuple: 489, enabling parameterisation with an 'arbitrary' number
of types.  In other words, a *note TypeVarTuple: 489. is a 'variadic'
type variable, enabling 'variadic' generics.

This enables a wide variety of use cases.  In particular, it allows the
type of array-like structures in numerical computing libraries such as
NumPy and TensorFlow to be parameterised with the array 'shape'.  Static
type checkers will now be able to catch shape-related bugs in code that
uses these libraries.

See PEP 646(3) for more details.

(Contributed by Matthew Rahtz in bpo-43224(4), with contributions by
Serhiy Storchaka and Jelle Zijlstra.  PEP written by Mark Mendoza,
Matthew Rahtz, Pradeep Kumar Srinivasan, and Vincent Siles.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0646/

   (3) https://peps.python.org/pep-0646/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43224


File: python.info,  Node: PEP 655 Marking individual TypedDict items as required or not-required,  Next: PEP 673 Self type,  Prev: PEP 646 Variadic generics,  Up: New Features Related to Type Hints

1.4.3.2 PEP 655: Marking individual ‘TypedDict’ items as required or not-required
.................................................................................

*note Required: 7e1. and *note NotRequired: 7e2. provide a
straightforward way to mark whether individual items in a *note
TypedDict: 332. must be present.  Previously, this was only possible
using inheritance.

All fields are still required by default, unless the 'total' parameter
is set to ‘False’, in which case all fields are still not-required by
default.  For example, the following specifies a ‘TypedDict’ with one
required and one not-required key:

     class Movie(TypedDict):
        title: str
        year: NotRequired[int]

     m1: Movie = {"title": "Black Panther", "year": 2018}  # OK
     m2: Movie = {"title": "Star Wars"}  # OK (year is not required)
     m3: Movie = {"year": 2022}  # ERROR (missing required field title)

The following definition is equivalent:

     class Movie(TypedDict, total=False):
        title: Required[str]
        year: int

See PEP 655(1) for more details.

(Contributed by David Foster and Jelle Zijlstra in bpo-47087(2).  PEP
written by David Foster.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0655/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=47087


File: python.info,  Node: PEP 673 Self type,  Next: PEP 675 Arbitrary literal string type,  Prev: PEP 655 Marking individual TypedDict items as required or not-required,  Up: New Features Related to Type Hints

1.4.3.3 PEP 673: ‘Self’ type
............................

The new *note Self: 7e4. annotation provides a simple and intuitive way
to annotate methods that return an instance of their class.  This
behaves the same as the *note TypeVar: 487.-based approach specified in
PEP 484(1), but is more concise and easier to follow.

Common use cases include alternative constructors provided as *note
classmethod: 48f.s, and *note __enter__(): 7e5. methods that return
‘self’:

     class MyLock:
         def __enter__(self) -> Self:
             self.lock()
             return self

         ...

     class MyInt:
         @classmethod
         def fromhex(cls, s: str) -> Self:
             return cls(int(s, 16))

         ...

*note Self: 7e4. can also be used to annotate method parameters or
attributes of the same type as their enclosing class.

See PEP 673(2) for more details.

(Contributed by James Hilton-Balfe in bpo-46534(3).  PEP written by
Pradeep Kumar Srinivasan and James Hilton-Balfe.)

   ---------- Footnotes ----------

   (1) 
https://peps.python.org/pep-0484/#annotating-instance-and-class-methods

   (2) https://peps.python.org/pep-0673/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46534


File: python.info,  Node: PEP 675 Arbitrary literal string type,  Next: PEP 681 Data class transforms,  Prev: PEP 673 Self type,  Up: New Features Related to Type Hints

1.4.3.4 PEP 675: Arbitrary literal string type
..............................................

The new *note LiteralString: 7e7. annotation may be used to indicate
that a function parameter can be of any literal string type.  This
allows a function to accept arbitrary literal string types, as well as
strings created from other literal strings.  Type checkers can then
enforce that sensitive functions, such as those that execute SQL
statements or shell commands, are called only with static arguments,
providing protection against injection attacks.

For example, a SQL query function could be annotated as follows:

     def run_query(sql: LiteralString) -> ...
         ...

     def caller(
         arbitrary_string: str,
         query_string: LiteralString,
         table_name: LiteralString,
     ) -> None:
         run_query("SELECT * FROM students")       # ok
         run_query(query_string)                   # ok
         run_query("SELECT * FROM " + table_name)  # ok
         run_query(arbitrary_string)               # type checker error
         run_query(                                # type checker error
             f"SELECT * FROM students WHERE name = {arbitrary_string}"
         )

See PEP 675(1) for more details.

(Contributed by Jelle Zijlstra in bpo-47088(2).  PEP written by Pradeep
Kumar Srinivasan and Graham Bleaney.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0675/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=47088


File: python.info,  Node: PEP 681 Data class transforms,  Next: PEP 563 may not be the future,  Prev: PEP 675 Arbitrary literal string type,  Up: New Features Related to Type Hints

1.4.3.5 PEP 681: Data class transforms
......................................

*note dataclass_transform: 6fc. may be used to decorate a class,
metaclass, or a function that is itself a decorator.  The presence of
‘@dataclass_transform()’ tells a static type checker that the decorated
object performs runtime «magic» that transforms a class, giving it *note
dataclass: 4e2.-like behaviors.

For example:

     # The create_model decorator is defined by a library.
     @typing.dataclass_transform()
     def create_model(cls: Type[T]) -> Type[T]:
         cls.__init__ = ...
         cls.__eq__ = ...
         cls.__ne__ = ...
         return cls

     # The create_model decorator can now be used to create new model classes:
     @create_model
     class CustomerModel:
         id: int
         name: str

     c = CustomerModel(id=327, name="Eric Idle")

See PEP 681(1) for more details.

(Contributed by Jelle Zijlstra in gh-91860(2).  PEP written by Erik De
Bonte and Eric Traut.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0681/

   (2) https://github.com/python/cpython/issues/91860


File: python.info,  Node: PEP 563 may not be the future,  Prev: PEP 681 Data class transforms,  Up: New Features Related to Type Hints

1.4.3.6 PEP 563 may not be the future
.....................................

PEP 563(1) Postponed Evaluation of Annotations (the ‘from __future__
import annotations’ *note future statement: 45d.) that was originally
planned for release in Python 3.10 has been put on hold indefinitely.
See this message from the Steering Council(2) for more information.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0563/

   (2) 
https://mail.python.org/archives/list/python-dev@python.org/message/VIZEBX5EYMSYIJNDBF6DMUMZOCWHARSO/


File: python.info,  Node: Other Language Changes<2>,  Next: Other CPython Implementation Changes,  Prev: New Features Related to Type Hints,  Up: What’s New In Python 3 11

1.4.4 Other Language Changes
----------------------------

   * Starred unpacking expressions can now be used in *note for: 34a.
     statements.  (See bpo-46725(1) for more details.)

   * Asynchronous *note comprehensions: 7ed. are now allowed inside
     comprehensions in *note asynchronous functions: 7ee.  Outer
     comprehensions implicitly become asynchronous in this case.
     (Contributed by Serhiy Storchaka in bpo-33346(2).)

   * A *note TypeError: 198. is now raised instead of an *note
     AttributeError: 5f0. in *note with: 186. statements and *note
     contextlib.ExitStack.enter_context(): 7ef. for objects that do not
     support the *note context manager: 1e1. protocol, and in *note
     async with: 185. statements and *note
     contextlib.AsyncExitStack.enter_async_context(): 7f0. for objects
     not supporting the *note asynchronous context manager: 7f1.
     protocol.  (Contributed by Serhiy Storchaka in bpo-12022(3) and
     bpo-44471(4).)

   * Added *note object.__getstate__(): 7f2, which provides the default
     implementation of the ‘__getstate__()’ method.  *note copy: 29.ing
     and *note pickle: ab.ing instances of subclasses of builtin types
     *note bytearray: 344, *note set: 184, *note frozenset: 7f3, *note
     collections.OrderedDict: 7f4, *note collections.deque: 7f5, *note
     weakref.WeakSet: 7f6, and *note datetime.tzinfo: 7f7. now copies
     and pickles instance attributes implemented as *note slots: 7f8.
     This change has an unintended side effect: It trips up a small
     minority of existing Python projects not expecting *note
     object.__getstate__(): 7f2. to exist.  See the later comments on
     gh-70766(5) for discussions of what workarounds such code may need.
     (Contributed by Serhiy Storchaka in bpo-26579(6).)

   * Added a *note -P: 7c2. command line option and a *note
     PYTHONSAFEPATH: 7c3. environment variable, which disable the
     automatic prepending to *note sys.path: 3e4. of the script’s
     directory when running a script, or the current directory when
     using *note -c: 1a8. and *note -m: 23c.  This ensures only stdlib
     and installed modules are picked up by *note import: 7f9, and
     avoids unintentionally or maliciously shadowing modules with those
     in a local (and typically user-writable) directory.  (Contributed
     by Victor Stinner in gh-57684(7).)

   * A ‘"z"’ option was added to the *note Format Specification
     Mini-Language: 4fa. that coerces negative to positive zero after
     rounding to the format precision.  See PEP 682(8) for more details.
     (Contributed by John Belmonte in gh-90153(9).)

   * Bytes are no longer accepted on *note sys.path: 3e4.  Support broke
     sometime between Python 3.2 and 3.6, with no one noticing until
     after Python 3.10.0 was released.  In addition, bringing back
     support would be problematic due to interactions between *note -b:
     7fa. and *note sys.path_importer_cache: 7fb. when there is a
     mixture of *note str: 169. and *note bytes: 192. keys.
     (Contributed by Thomas Grainger in gh-91181(10).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46725

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33346

   (3) https://bugs.python.org/issue?@action=redirect&bpo=12022

   (4) https://bugs.python.org/issue?@action=redirect&bpo=44471

   (5) https://github.com/python/cpython/issues/70766

   (6) https://bugs.python.org/issue?@action=redirect&bpo=26579

   (7) https://github.com/python/cpython/issues/57684

   (8) https://peps.python.org/pep-0682/

   (9) https://github.com/python/cpython/issues/90153

   (10) https://github.com/python/cpython/issues/91181


File: python.info,  Node: Other CPython Implementation Changes,  Next: New Modules<2>,  Prev: Other Language Changes<2>,  Up: What’s New In Python 3 11

1.4.5 Other CPython Implementation Changes
------------------------------------------

   * The special methods *note __complex__(): 7fe. for *note complex:
     197. and *note __bytes__(): 7ff. for *note bytes: 192. are
     implemented to support the *note typing.SupportsComplex: 800. and
     *note typing.SupportsBytes: 801. protocols.  (Contributed by Mark
     Dickinson and Donghee Na in bpo-24234(1).)

   * ‘siphash13’ is added as a new internal hashing algorithm.  It has
     similar security properties as ‘siphash24’, but it is slightly
     faster for long inputs.  *note str: 169, *note bytes: 192, and some
     other types now use it as the default algorithm for *note hash():
     802.  PEP 552(2) *note hash-based .pyc files: 803. now use
     ‘siphash13’ too.  (Contributed by Inada Naoki in bpo-29410(3).)

   * When an active exception is re-raised by a *note raise: 804.
     statement with no parameters, the traceback attached to this
     exception is now always ‘sys.exc_info()[1].__traceback__’.  This
     means that changes made to the traceback in the current *note
     except: 1ab. clause are reflected in the re-raised exception.
     (Contributed by Irit Katriel in bpo-45711(4).)

   * The interpreter state’s representation of handled exceptions (aka
     ‘exc_info’ or ‘_PyErr_StackItem’) now only has the ‘exc_value’
     field; ‘exc_type’ and ‘exc_traceback’ have been removed, as they
     can be derived from ‘exc_value’.  (Contributed by Irit Katriel in
     bpo-45711(5).)

   * A new *note command line option: 805, ‘AppendPath’, has been added
     for the Windows installer.  It behaves similarly to ‘PrependPath’,
     but appends the install and scripts directories instead of
     prepending them.  (Contributed by Bastian Neuburger in
     bpo-44934(6).)

   * The *note PyConfig.module_search_paths_set: 806. field must now be
     set to ‘1’ for initialization to use *note
     PyConfig.module_search_paths: 643. to initialize *note sys.path:
     3e4.  Otherwise, initialization will recalculate the path and
     replace any values added to ‘module_search_paths’.

   * The output of the *note -help: 807. option now fits in 50 lines/80
     columns.  Information about *note Python environment variables:
     808. and *note -X: 16f. options is now available using the
     respective *note -help-env: 809. and *note -help-xoptions: 80a.
     flags, and with the new *note -help-all: 80b.  (Contributed by Éric
     Araujo in bpo-46142(7).)

   * Converting between *note int: 19b. and *note str: 169. in bases
     other than 2 (binary), 4, 8 (octal), 16 (hexadecimal), or 32 such
     as base 10 (decimal) now raises a *note ValueError: 2ec. if the
     number of digits in string form is above a limit to avoid potential
     denial of service attacks due to the algorithmic complexity.  This
     is a mitigation for CVE 2020-10735(8).  This limit can be
     configured or disabled by environment variable, command line flag,
     or *note sys: df. APIs.  See the *note integer string conversion
     length limitation: 80c. documentation.  The default limit is 4300
     digits in string form.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24234

   (2) https://peps.python.org/pep-0552/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29410

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45711

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45711

   (6) https://bugs.python.org/issue?@action=redirect&bpo=44934

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46142

   (8) https://www.cve.org/CVERecord?id=CVE-2020-10735


File: python.info,  Node: New Modules<2>,  Next: Improved Modules<2>,  Prev: Other CPython Implementation Changes,  Up: What’s New In Python 3 11

1.4.6 New Modules
-----------------

   * *note tomllib: 102.: For parsing TOML(1). See PEP 680(2) for more
     details.  (Contributed by Taneli Hukkinen in bpo-40059(3).)

   * *note wsgiref.types: 122.: WSGI(4)-specific types for static type
     checking.  (Contributed by Sebastian Rittau in bpo-42012(5).)

   ---------- Footnotes ----------

   (1) https://toml.io/

   (2) https://peps.python.org/pep-0680/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40059

   (4) https://peps.python.org/pep-3333/

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42012


File: python.info,  Node: Improved Modules<2>,  Next: Optimizations<3>,  Prev: New Modules<2>,  Up: What’s New In Python 3 11

1.4.7 Improved Modules
----------------------

* Menu:

* asyncio: asyncio<6>.
* contextlib::
* dataclasses::
* datetime: datetime<2>.
* enum: enum<3>.
* fcntl::
* fractions: fractions<4>.
* functools: functools<2>.
* gzip: gzip<2>.
* hashlib: hashlib<2>.
* IDLE and idlelib::
* inspect: inspect<3>.
* locale: locale<3>.
* logging::
* math: math<3>.
* operator: operator<2>.
* os: os<4>.
* pathlib: pathlib<7>.
* re: re<4>.
* shutil: shutil<3>.
* socket: socket<2>.
* sqlite3: sqlite3<5>.
* string::
* sys: sys<4>.
* sysconfig: sysconfig<2>.
* tempfile: tempfile<3>.
* threading: threading<3>.
* time: time<2>.
* tkinter: tkinter<4>.
* traceback: traceback<2>.
* typing: typing<5>.
* unicodedata: unicodedata<4>.
* unittest: unittest<5>.
* venv: venv<2>.
* warnings: warnings<2>.
* zipfile: zipfile<2>.


File: python.info,  Node: asyncio<6>,  Next: contextlib,  Up: Improved Modules<2>

1.4.7.1 asyncio
...............

   * Added the *note TaskGroup: 4d2. class, an *note asynchronous
     context manager: 813. holding a group of tasks that will wait for
     all of them upon exit.  For new code this is recommended over using
     *note create_task(): 1c9. and *note gather(): 814. directly.
     (Contributed by Yury Selivanov and others in gh-90908(1).)

   * Added *note timeout(): 815, an asynchronous context manager for
     setting a timeout on asynchronous operations.  For new code this is
     recommended over using *note wait_for(): 816. directly.
     (Contributed by Andrew Svetlov in gh-90927(2).)

   * Added the *note Runner: 2f5. class, which exposes the machinery
     used by *note run(): 2f3.  (Contributed by Andrew Svetlov in
     gh-91218(3).)

   * Added the *note Barrier: 817. class to the synchronization
     primitives in the asyncio library, and the related *note
     BrokenBarrierError: 818. exception.  (Contributed by Yves Duprat
     and Andrew Svetlov in gh-87518(4).)

   * Added keyword argument 'all_errors' to *note
     asyncio.loop.create_connection(): 819. so that multiple connection
     errors can be raised as an *note ExceptionGroup: 4d3.

   * Added the *note asyncio.StreamWriter.start_tls(): 81a. method for
     upgrading existing stream-based connections to TLS. (Contributed by
     Ian Good in bpo-34975(5).)

   * Added raw datagram socket functions to the event loop: *note
     sock_sendto(): 81b, *note sock_recvfrom(): 81c. and *note
     sock_recvfrom_into(): 81d.  These have implementations in *note
     SelectorEventLoop: 314. and *note ProactorEventLoop: 81e.
     (Contributed by Alex Grönholm in bpo-46805(6).)

   * Added *note cancelling(): 4d6. and *note uncancel(): 4d7. methods
     to *note Task: 1c7.  These are primarily intended for internal use,
     notably by *note TaskGroup: 4d2.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/90908

   (2) https://github.com/python/cpython/issues/90927

   (3) https://github.com/python/cpython/issues/91218

   (4) https://github.com/python/cpython/issues/87518

   (5) https://bugs.python.org/issue?@action=redirect&bpo=34975

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46805


File: python.info,  Node: contextlib,  Next: dataclasses,  Prev: asyncio<6>,  Up: Improved Modules<2>

1.4.7.2 contextlib
..................

   * Added non parallel-safe *note chdir(): 821. context manager to
     change the current working directory and then restore it on exit.
     Simple wrapper around *note chdir(): 822.  (Contributed by Filipe
     Laíns in bpo-25625(1))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25625


File: python.info,  Node: dataclasses,  Next: datetime<2>,  Prev: contextlib,  Up: Improved Modules<2>

1.4.7.3 dataclasses
...................

   * Change field default mutability check, allowing only defaults which
     are *note hashable: 825. instead of any object which is not an
     instance of *note dict: 183, *note list: 24d. or *note set: 184.
     (Contributed by Eric V. Smith in bpo-44674(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44674


File: python.info,  Node: datetime<2>,  Next: enum<3>,  Prev: dataclasses,  Up: Improved Modules<2>

1.4.7.4 datetime
................

   * Add *note datetime.UTC: 714, a convenience alias for *note
     datetime.timezone.utc: 828.  (Contributed by Kabir Kwatra in
     gh-91973(1).)

   * *note datetime.date.fromisoformat(): 829, *note
     datetime.time.fromisoformat(): 82a. and *note
     datetime.datetime.fromisoformat(): 82b. can now be used to parse
     most ISO 8601 formats (barring only those that support fractional
     hours and minutes).  (Contributed by Paul Ganssle in gh-80010(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91973

   (2) https://github.com/python/cpython/issues/80010


File: python.info,  Node: enum<3>,  Next: fcntl,  Prev: datetime<2>,  Up: Improved Modules<2>

1.4.7.5 enum
............

   * Renamed ‘EnumMeta’ to *note EnumType: 4f8. (‘EnumMeta’ kept as an
     alias).

   * Added *note StrEnum: 82e, with members that can be used as (and
     must be) strings.

   * Added *note ReprEnum: 82f, which only modifies the *note
     __repr__(): 830. of members while returning their literal values
     (rather than names) for *note __str__(): 831. and *note
     __format__(): 832. (used by *note str(): 169, *note format(): 199.
     and *note f-string: 66b.s).

   * Changed *note Enum.__format__(): 833. (the default for *note
     format(): 199, *note str.format(): 834. and *note f-string: 66b.s)
     to always produce the same result as *note Enum.__str__(): 835.:
     for enums inheriting from *note ReprEnum: 82f. it will be the
     member’s value; for all other enums it will be the enum and member
     name (e.g.  ‘Color.RED’).

   * Added a new 'boundary' class parameter to *note Flag: 836. enums
     and the *note FlagBoundary: 837. enum with its options, to control
     how to handle out-of-range flag values.

   * Added the *note verify(): 838. enum decorator and the *note
     EnumCheck: 839. enum with its options, to check enum classes
     against several specific constraints.

   * Added the *note member(): 83a. and *note nonmember(): 83b.
     decorators, to ensure the decorated object is/is not converted to
     an enum member.

   * Added the *note property(): 83c. decorator, which works like *note
     property(): 4b4. except for enums.  Use this instead of *note
     types.DynamicClassAttribute(): 83d.

   * Added the *note global_enum(): 83e. enum decorator, which adjusts
     *note __repr__(): 830. and *note __str__(): 831. to show values as
     members of their module rather than the enum class.  For example,
     ‘'re.ASCII'’ for the *note ASCII: 83f. member of *note
     re.RegexFlag: 840. rather than ‘'RegexFlag.ASCII'’.

   * Enhanced *note Flag: 836. to support *note len(): 841, iteration
     and *note in: 34b./*note not in: 842. on its members.  For example,
     the following now works: ‘len(AFlag(3)) == 2 and list(AFlag(3)) ==
     (AFlag.ONE, AFlag.TWO)’

   * Changed *note Enum: 843. and *note Flag: 836. so that members are
     now defined before *note __init_subclass__(): 844. is called; *note
     dir(): 845. now includes methods, etc., from mixed-in data types.

   * Changed *note Flag: 836. to only consider primary values (power of
     two) canonical while composite values (‘3’, ‘6’, ‘10’, etc.)  are
     considered aliases; inverted flags are coerced to their positive
     equivalent.


File: python.info,  Node: fcntl,  Next: fractions<4>,  Prev: enum<3>,  Up: Improved Modules<2>

1.4.7.6 fcntl
.............

   * On FreeBSD, the ‘F_DUP2FD’ and ‘F_DUP2FD_CLOEXEC’ flags
     respectively are supported, the former equals to ‘dup2’ usage while
     the latter set the ‘FD_CLOEXEC’ flag in addition.


File: python.info,  Node: fractions<4>,  Next: functools<2>,  Prev: fcntl,  Up: Improved Modules<2>

1.4.7.7 fractions
.................

   * Support PEP 515(1)-style initialization of *note Fraction: 213.
     from string.  (Contributed by Sergey B Kirpichev in bpo-44258(2).)

   * *note Fraction: 213. now implements an ‘__int__’ method, so that an
     ‘isinstance(some_fraction, typing.SupportsInt)’ check passes.
     (Contributed by Mark Dickinson in bpo-44547(3).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0515/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=44258

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44547


File: python.info,  Node: functools<2>,  Next: gzip<2>,  Prev: fractions<4>,  Up: Improved Modules<2>

1.4.7.8 functools
.................

   * *note functools.singledispatch(): 84c. now supports *note
     types.UnionType: 2a7. and *note typing.Union: 2a8. as annotations
     to the dispatch argument.:

          >>> from functools import singledispatch
          >>> @singledispatch
          ... def fun(arg, verbose=False):
          ...     if verbose:
          ...         print("Let me just say,", end=" ")
          ...     print(arg)
          ...
          >>> @fun.register
          ... def _(arg: int | float, verbose=False):
          ...     if verbose:
          ...         print("Strength in numbers, eh?", end=" ")
          ...     print(arg)
          ...
          >>> from typing import Union
          >>> @fun.register
          ... def _(arg: Union[list, set], verbose=False):
          ...     if verbose:
          ...         print("Enumerate this:")
          ...     for i, elem in enumerate(arg):
          ...         print(i, elem)
          ...

     (Contributed by Yurii Karabas in bpo-46014(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46014


File: python.info,  Node: gzip<2>,  Next: hashlib<2>,  Prev: functools<2>,  Up: Improved Modules<2>

1.4.7.9 gzip
............

   * The *note gzip.compress(): 84f. function is now faster when used
     with the 'mtime=0' argument as it delegates the compression
     entirely to a single *note zlib.compress(): 850. operation.  There
     is one side effect of this change: The gzip file header contains an
     «OS» byte in its header.  That was traditionally always set to a
     value of 255 representing «unknown» by the *note gzip: 6b. module.
     Now, when using *note compress(): 84f. with 'mtime=0', it may be
     set to a different value by the underlying zlib C library Python
     was linked against.  (See gh-112346(1) for details on the side
     effect.)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/112346


File: python.info,  Node: hashlib<2>,  Next: IDLE and idlelib,  Prev: gzip<2>,  Up: Improved Modules<2>

1.4.7.10 hashlib
................

   * *note hashlib.blake2b(): 853. and *note hashlib.blake2s(): 854. now
     prefer libb2(1) over Python’s vendored copy.  (Contributed by
     Christian Heimes in bpo-47095(2).)

   * The internal ‘_sha3’ module with SHA3 and SHAKE algorithms now uses
     'tiny_sha3' instead of the 'Keccak Code Package' to reduce code and
     binary size.  The *note hashlib: 6c. module prefers optimized SHA3
     and SHAKE implementations from OpenSSL. The change affects only
     installations without OpenSSL support.  (Contributed by Christian
     Heimes in bpo-47098(3).)

   * Add *note hashlib.file_digest(): 855, a helper function for
     efficient hashing of files or file-like objects.  (Contributed by
     Christian Heimes in gh-89313(4).)

   ---------- Footnotes ----------

   (1) https://www.blake2.net/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=47095

   (3) https://bugs.python.org/issue?@action=redirect&bpo=47098

   (4) https://github.com/python/cpython/issues/89313


File: python.info,  Node: IDLE and idlelib,  Next: inspect<3>,  Prev: hashlib<2>,  Up: Improved Modules<2>

1.4.7.11 IDLE and idlelib
.........................

   * Apply syntax highlighting to ‘.pyi’ files.  (Contributed by Alex
     Waygood and Terry Jan Reedy in bpo-45447(1).)

   * Include prompts when saving Shell with inputs and outputs.
     (Contributed by Terry Jan Reedy in gh-95191(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45447

   (2) https://github.com/python/cpython/issues/95191


File: python.info,  Node: inspect<3>,  Next: locale<3>,  Prev: IDLE and idlelib,  Up: Improved Modules<2>

1.4.7.12 inspect
................

   * Add *note getmembers_static(): 85a. to return all members without
     triggering dynamic lookup via the descriptor protocol.
     (Contributed by Weipeng Hong in bpo-30533(1).)

   * Add *note ismethodwrapper(): 85b. for checking if the type of an
     object is a *note MethodWrapperType: 85c.  (Contributed by Hakan
     Çelik in bpo-29418(2).)

   * Change the frame-related functions in the *note inspect: 82. module
     to return new *note FrameInfo: 85d. and *note Traceback: 85e. class
     instances (backwards compatible with the previous *note named
     tuple: 85f.-like interfaces) that includes the extended PEP 657(3)
     position information (end line number, column and end column).  The
     affected functions are:

        * *note inspect.getframeinfo(): 860.

        * *note inspect.getouterframes(): 861.

        * *note inspect.getinnerframes(): 862,

        * *note inspect.stack(): 863.

        * *note inspect.trace(): 864.

     (Contributed by Pablo Galindo in gh-88116(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30533

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29418

   (3) https://peps.python.org/pep-0657/

   (4) https://github.com/python/cpython/issues/88116


File: python.info,  Node: locale<3>,  Next: logging,  Prev: inspect<3>,  Up: Improved Modules<2>

1.4.7.13 locale
...............

   * Add *note locale.getencoding(): 329. to get the current locale
     encoding.  It is similar to ‘locale.getpreferredencoding(False)’
     but ignores the *note Python UTF-8 Mode: 867.


File: python.info,  Node: logging,  Next: math<3>,  Prev: locale<3>,  Up: Improved Modules<2>

1.4.7.14 logging
................

   * Added *note getLevelNamesMapping(): 86a. to return a mapping from
     logging level names (e.g.  ‘'CRITICAL'’) to the values of their
     corresponding *note Logging Levels: 86b. (e.g.  ‘50’, by default).
     (Contributed by Andrei Kulakovin in gh-88024(1).)

   * Added a *note createSocket(): 86c. method to *note SysLogHandler:
     86d, to match *note SocketHandler.createSocket(): 86e.  It is
     called automatically during handler initialization and when
     emitting an event, if there is no active socket.  (Contributed by
     Kirill Pinchuk in gh-88457(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/88024

   (2) https://github.com/python/cpython/issues/88457


File: python.info,  Node: math<3>,  Next: operator<2>,  Prev: logging,  Up: Improved Modules<2>

1.4.7.15 math
.............

   * Add *note math.exp2(): 871.: return 2 raised to the power of x.
     (Contributed by Gideon Mitchell in bpo-45917(1).)

   * Add *note math.cbrt(): 872.: return the cube root of x.
     (Contributed by Ajith Ramachandran in bpo-44357(2).)

   * The behaviour of two *note math.pow(): 873. corner cases was
     changed, for consistency with the IEEE 754 specification.  The
     operations ‘math.pow(0.0, -math.inf)’ and ‘math.pow(-0.0,
     -math.inf)’ now return ‘inf’.  Previously they raised *note
     ValueError: 2ec.  (Contributed by Mark Dickinson in bpo-44339(3).)

   * The *note math.nan: 874. value is now always available.
     (Contributed by Victor Stinner in bpo-46917(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45917

   (2) https://bugs.python.org/issue?@action=redirect&bpo=44357

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44339

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46917


File: python.info,  Node: operator<2>,  Next: os<4>,  Prev: math<3>,  Up: Improved Modules<2>

1.4.7.16 operator
.................

   * A new function ‘operator.call’ has been added, such that
     ‘operator.call(obj, *args, **kwargs) == obj(*args, **kwargs)’.
     (Contributed by Antony Lee in bpo-44019(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44019


File: python.info,  Node: os<4>,  Next: pathlib<7>,  Prev: operator<2>,  Up: Improved Modules<2>

1.4.7.17 os
...........

   * On Windows, *note os.urandom(): 747. now uses ‘BCryptGenRandom()’,
     instead of ‘CryptGenRandom()’ which is deprecated.  (Contributed by
     Donghee Na in bpo-44611(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44611


File: python.info,  Node: pathlib<7>,  Next: re<4>,  Prev: os<4>,  Up: Improved Modules<2>

1.4.7.18 pathlib
................

   * *note glob(): 538. and *note rglob(): 539. return only directories
     if 'pattern' ends with a pathname components separator: *note sep:
     87b. or *note altsep: 87c.  (Contributed by Eisuke Kawasima in
     bpo-22276(1) and bpo-33392(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22276

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33392


File: python.info,  Node: re<4>,  Next: shutil<3>,  Prev: pathlib<7>,  Up: Improved Modules<2>

1.4.7.19 re
...........

   * Atomic grouping (‘(?>...)’) and possessive quantifiers (‘*+’, ‘++’,
     ‘?+’, ‘{m,n}+’) are now supported in regular expressions.
     (Contributed by Jeffrey C. Jacobs and Serhiy Storchaka in
     bpo-433030(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=433030


File: python.info,  Node: shutil<3>,  Next: socket<2>,  Prev: re<4>,  Up: Improved Modules<2>

1.4.7.20 shutil
...............

   * Add optional parameter 'dir_fd' in *note shutil.rmtree(): 356.
     (Contributed by Serhiy Storchaka in bpo-46245(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46245


File: python.info,  Node: socket<2>,  Next: sqlite3<5>,  Prev: shutil<3>,  Up: Improved Modules<2>

1.4.7.21 socket
...............

   * Add CAN Socket support for NetBSD. (Contributed by Thomas Klausner
     in bpo-30512(1).)

   * *note create_connection(): 883. has an option to raise, in case of
     failure to connect, an *note ExceptionGroup: 4d3. containing all
     errors instead of only raising the last error.  (Contributed by
     Irit Katriel in bpo-29980(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30512

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29980


File: python.info,  Node: sqlite3<5>,  Next: string,  Prev: socket<2>,  Up: Improved Modules<2>

1.4.7.22 sqlite3
................

   * You can now disable the authorizer by passing *note None: 886. to
     *note set_authorizer(): 5a9.  (Contributed by Erlend E. Aasland in
     bpo-44491(1).)

   * Collation name *note create_collation(): 887. can now contain any
     Unicode character.  Collation names with invalid characters now
     raise *note UnicodeEncodeError: 888. instead of *note
     sqlite3.ProgrammingError: 305.  (Contributed by Erlend E. Aasland
     in bpo-44688(2).)

   * *note sqlite3: d4. exceptions now include the SQLite extended error
     code as *note sqlite_errorcode: 889. and the SQLite error name as
     *note sqlite_errorname: 88a.  (Contributed by Aviv Palivoda, Daniel
     Shahaf, and Erlend E. Aasland in bpo-16379(3) and bpo-24139(4).)

   * Add *note setlimit(): 88b. and *note getlimit(): 88c. to *note
     sqlite3.Connection: 54e. for setting and getting SQLite limits by
     connection basis.  (Contributed by Erlend E. Aasland in
     bpo-45243(5).)

   * *note sqlite3: d4. now sets *note sqlite3.threadsafety: 88d. based
     on the default threading mode the underlying SQLite library has
     been compiled with.  (Contributed by Erlend E. Aasland in
     bpo-45613(6).)

   * *note sqlite3: d4. C callbacks now use unraisable exceptions if
     callback tracebacks are enabled.  Users can now register an *note
     unraisable hook handler: 508. to improve their debug experience.
     (Contributed by Erlend E. Aasland in bpo-45828(7).)

   * Fetch across rollback no longer raises *note InterfaceError: 88e.
     Instead we leave it to the SQLite library to handle these cases.
     (Contributed by Erlend E. Aasland in bpo-44092(8).)

   * Add *note serialize(): 88f. and *note deserialize(): 890. to *note
     sqlite3.Connection: 54e. for serializing and deserializing
     databases.  (Contributed by Erlend E. Aasland in bpo-41930(9).)

   * Add *note create_window_function(): 891. to *note
     sqlite3.Connection: 54e. for creating aggregate window functions.
     (Contributed by Erlend E. Aasland in bpo-34916(10).)

   * Add *note blobopen(): 892. to *note sqlite3.Connection: 54e.  *note
     sqlite3.Blob: 893. allows incremental I/O operations on blobs.
     (Contributed by Aviv Palivoda and Erlend E. Aasland in
     bpo-24905(11).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44491

   (2) https://bugs.python.org/issue?@action=redirect&bpo=44688

   (3) https://bugs.python.org/issue?@action=redirect&bpo=16379

   (4) https://bugs.python.org/issue?@action=redirect&bpo=24139

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45243

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45613

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45828

   (8) https://bugs.python.org/issue?@action=redirect&bpo=44092

   (9) https://bugs.python.org/issue?@action=redirect&bpo=41930

   (10) https://bugs.python.org/issue?@action=redirect&bpo=34916

   (11) https://bugs.python.org/issue?@action=redirect&bpo=24905


File: python.info,  Node: string,  Next: sys<4>,  Prev: sqlite3<5>,  Up: Improved Modules<2>

1.4.7.23 string
...............

   * Add *note get_identifiers(): 896. and *note is_valid(): 897. to
     *note string.Template: 898, which respectively return all valid
     placeholders, and whether any invalid placeholders are present.
     (Contributed by Ben Kehoe in gh-90465(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/90465


File: python.info,  Node: sys<4>,  Next: sysconfig<2>,  Prev: string,  Up: Improved Modules<2>

1.4.7.24 sys
............

   * *note sys.exc_info(): 89b. now derives the ‘type’ and ‘traceback’
     fields from the ‘value’ (the exception instance), so when an
     exception is modified while it is being handled, the changes are
     reflected in the results of subsequent calls to ‘exc_info()’.
     (Contributed by Irit Katriel in bpo-45711(1).)

   * Add *note sys.exception(): 89c. which returns the active exception
     instance (equivalent to ‘sys.exc_info()[1]’).  (Contributed by Irit
     Katriel in bpo-46328(2).)

   * Add the *note sys.flags.safe_path: 89d. flag.  (Contributed by
     Victor Stinner in gh-57684(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45711

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46328

   (3) https://github.com/python/cpython/issues/57684


File: python.info,  Node: sysconfig<2>,  Next: tempfile<3>,  Prev: sys<4>,  Up: Improved Modules<2>

1.4.7.25 sysconfig
..................

   * Three new *note installation schemes: 449. ('posix_venv', 'nt_venv'
     and 'venv') were added and are used when Python creates new virtual
     environments or when it is running from a virtual environment.  The
     first two schemes ('posix_venv' and 'nt_venv') are OS-specific for
     non-Windows and Windows, the 'venv' is essentially an alias to one
     of them according to the OS Python runs on.  This is useful for
     downstream distributors who modify *note
     sysconfig.get_preferred_scheme(): 8a0.  Third party code that
     creates new virtual environments should use the new 'venv'
     installation scheme to determine the paths, as does *note venv:
     117.  (Contributed by Miro Hrončok in bpo-45413(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45413


File: python.info,  Node: tempfile<3>,  Next: threading<3>,  Prev: sysconfig<2>,  Up: Improved Modules<2>

1.4.7.26 tempfile
.................

   * *note SpooledTemporaryFile: 8a3. objects now fully implement the
     methods of *note io.BufferedIOBase: 8a4. or *note io.TextIOBase:
     8a5. (depending on file mode).  This lets them work correctly with
     APIs that expect file-like objects, such as compression modules.
     (Contributed by Carey Metcalfe in gh-70363(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/70363


File: python.info,  Node: threading<3>,  Next: time<2>,  Prev: tempfile<3>,  Up: Improved Modules<2>

1.4.7.27 threading
..................

   * On Unix, if the ‘sem_clockwait()’ function is available in the C
     library (glibc 2.30 and newer), the *note threading.Lock.acquire():
     8a8. method now uses the monotonic clock (*note
     time.CLOCK_MONOTONIC: 8a9.) for the timeout, rather than using the
     system clock (*note time.CLOCK_REALTIME: 8aa.), to not be affected
     by system clock changes.  (Contributed by Victor Stinner in
     bpo-41710(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41710


File: python.info,  Node: time<2>,  Next: tkinter<4>,  Prev: threading<3>,  Up: Improved Modules<2>

1.4.7.28 time
.............

   * On Unix, *note time.sleep(): 8ad. now uses the ‘clock_nanosleep()’
     or ‘nanosleep()’ function, if available, which has a resolution of
     1 nanosecond (10^-9 seconds), rather than using ‘select()’ which
     has a resolution of 1 microsecond (10^-6 seconds).  (Contributed by
     Benjamin Szőke and Victor Stinner in bpo-21302(1).)

   * On Windows 8.1 and newer, *note time.sleep(): 8ad. now uses a
     waitable timer based on high-resolution timers(2) which has a
     resolution of 100 nanoseconds (10^-7 seconds).  Previously, it had
     a resolution of 1 millisecond (10^-3 seconds).  (Contributed by
     Benjamin Szőke, Donghee Na, Eryk Sun and Victor Stinner in
     bpo-21302(3) and bpo-45429(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21302

   (2) 
https://docs.microsoft.com/en-us/windows-hardware/drivers/kernel/high-resolution-timers

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21302

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45429


File: python.info,  Node: tkinter<4>,  Next: traceback<2>,  Prev: time<2>,  Up: Improved Modules<2>

1.4.7.29 tkinter
................

   * Added method ‘info_patchlevel()’ which returns the exact version of
     the Tcl library as a named tuple similar to *note sys.version_info:
     8b0.  (Contributed by Serhiy Storchaka in gh-91827(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91827


File: python.info,  Node: traceback<2>,  Next: typing<5>,  Prev: tkinter<4>,  Up: Improved Modules<2>

1.4.7.30 traceback
..................

   * Add *note traceback.StackSummary.format_frame_summary(): 8b3. to
     allow users to override which frames appear in the traceback, and
     how they are formatted.  (Contributed by Ammar Askar in
     bpo-44569(1).)

   * Add *note traceback.TracebackException.print(): 8b4, which prints
     the formatted *note TracebackException: 563. instance to a file.
     (Contributed by Irit Katriel in bpo-33809(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44569

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33809


File: python.info,  Node: typing<5>,  Next: unicodedata<4>,  Prev: traceback<2>,  Up: Improved Modules<2>

1.4.7.31 typing
...............

For major changes, see *note New Features Related to Type Hints: 7dc.

   * Add *note typing.assert_never(): 8b7. and *note typing.Never: 8b8.
     *note typing.assert_never(): 8b7. is useful for asking a type
     checker to confirm that a line of code is not reachable.  At
     runtime, it raises an *note AssertionError: 8b9.  (Contributed by
     Jelle Zijlstra in gh-90633(1).)

   * Add *note typing.reveal_type(): 8ba.  This is useful for asking a
     type checker what type it has inferred for a given expression.  At
     runtime it prints the type of the received value.  (Contributed by
     Jelle Zijlstra in gh-90572(2).)

   * Add *note typing.assert_type(): 8bb.  This is useful for asking a
     type checker to confirm that the type it has inferred for a given
     expression matches the given type.  At runtime it simply returns
     the received value.  (Contributed by Jelle Zijlstra in
     gh-90638(3).)

   * *note typing.TypedDict: 332. types can now be generic.
     (Contributed by Samodya Abeysiriwardane in gh-89026(4).)

   * *note NamedTuple: 331. types can now be generic.  (Contributed by
     Serhiy Storchaka in bpo-43923(5).)

   * Allow subclassing of *note typing.Any: 8bc.  This is useful for
     avoiding type checker errors related to highly dynamic class, such
     as mocks.  (Contributed by Shantanu Jain in gh-91154(6).)

   * The *note typing.final(): 8bd. decorator now sets the ‘__final__’
     attributed on the decorated object.  (Contributed by Jelle Zijlstra
     in gh-90500(7).)

   * The *note typing.get_overloads(): 8be. function can be used for
     introspecting the overloads of a function.  *note
     typing.clear_overloads(): 8bf. can be used to clear all registered
     overloads of a function.  (Contributed by Jelle Zijlstra in
     gh-89263(8).)

   * The *note __init__(): 8c0. method of *note Protocol: 56b.
     subclasses is now preserved.  (Contributed by Adrian Garcia
     Badarasco in gh-88970(9).)

   * The representation of empty tuple types (‘Tuple[()]’) is
     simplified.  This affects introspection, e.g.
     ‘get_args(Tuple[()])’ now evaluates to ‘()’ instead of ‘((),)’.
     (Contributed by Serhiy Storchaka in gh-91137(10).)

   * Loosen runtime requirements for type annotations by removing the
     callable check in the private ‘typing._type_check’ function.
     (Contributed by Gregory Beauregard in gh-90802(11).)

   * *note typing.get_type_hints(): 8c1. now supports evaluating strings
     as forward references in *note PEP 585 generic aliases: 8c2.
     (Contributed by Niklas Rosenstein in gh-85542(12).)

   * *note typing.get_type_hints(): 8c1. no longer adds *note Optional:
     8c3. to parameters with ‘None’ as a default.  (Contributed by
     Nikita Sobolev in gh-90353(13).)

   * *note typing.get_type_hints(): 8c1. now supports evaluating bare
     stringified *note ClassVar: 56d. annotations.  (Contributed by
     Gregory Beauregard in gh-90711(14).)

   * *note typing.no_type_check(): 8c4. no longer modifies external
     classes and functions.  It also now correctly marks classmethods as
     not to be type checked.  (Contributed by Nikita Sobolev in
     gh-90729(15).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/90633

   (2) https://github.com/python/cpython/issues/90572

   (3) https://github.com/python/cpython/issues/90638

   (4) https://github.com/python/cpython/issues/89026

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43923

   (6) https://github.com/python/cpython/issues/91154

   (7) https://github.com/python/cpython/issues/90500

   (8) https://github.com/python/cpython/issues/89263

   (9) https://github.com/python/cpython/issues/88970

   (10) https://github.com/python/cpython/issues/91137

   (11) https://github.com/python/cpython/issues/90802

   (12) https://github.com/python/cpython/issues/85542

   (13) https://github.com/python/cpython/issues/90353

   (14) https://github.com/python/cpython/issues/90711

   (15) https://github.com/python/cpython/issues/90729


File: python.info,  Node: unicodedata<4>,  Next: unittest<5>,  Prev: typing<5>,  Up: Improved Modules<2>

1.4.7.32 unicodedata
....................

   * The Unicode database has been updated to version 14.0.0.
     (Contributed by Benjamin Peterson in bpo-45190(1)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45190


File: python.info,  Node: unittest<5>,  Next: venv<2>,  Prev: unicodedata<4>,  Up: Improved Modules<2>

1.4.7.33 unittest
.................

   * Added methods *note enterContext(): 8c9. and *note
     enterClassContext(): 8ca. of class *note TestCase: 2b3, method
     *note enterAsyncContext(): 8cb. of class *note
     IsolatedAsyncioTestCase: 361. and function *note
     unittest.enterModuleContext(): 8cc.  (Contributed by Serhiy
     Storchaka in bpo-45046(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45046


File: python.info,  Node: venv<2>,  Next: warnings<2>,  Prev: unittest<5>,  Up: Improved Modules<2>

1.4.7.34 venv
.............

   * When new Python virtual environments are created, the 'venv' *note
     sysconfig installation scheme: 449. is used to determine the paths
     inside the environment.  When Python runs in a virtual environment,
     the same installation scheme is the default.  That means that
     downstream distributors can change the default sysconfig install
     scheme without changing behavior of virtual environments.  Third
     party code that also creates new virtual environments should do the
     same.  (Contributed by Miro Hrončok in bpo-45413(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45413


File: python.info,  Node: warnings<2>,  Next: zipfile<2>,  Prev: venv<2>,  Up: Improved Modules<2>

1.4.7.35 warnings
.................

   * *note warnings.catch_warnings(): 179. now accepts arguments for
     *note warnings.simplefilter(): 8d1, providing a more concise way to
     locally ignore warnings or convert them to errors.  (Contributed by
     Zac Hatfield-Dodds in bpo-47074(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=47074


File: python.info,  Node: zipfile<2>,  Prev: warnings<2>,  Up: Improved Modules<2>

1.4.7.36 zipfile
................

   * Added support for specifying member name encoding for reading
     metadata in a *note ZipFile: 8d4.’s directory and file headers.
     (Contributed by Stephen J. Turnbull and Serhiy Storchaka in
     bpo-28080(1).)

   * Added *note ZipFile.mkdir(): 8d5. for creating new directories
     inside ZIP archives.  (Contributed by Sam Ezeh in gh-49083(2).)

   * Added *note stem: 8d6, *note suffix: 8d7. and *note suffixes: 8d8.
     to *note zipfile.Path: 8d9.  (Contributed by Miguel Brito in
     gh-88261(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28080

   (2) https://github.com/python/cpython/issues/49083

   (3) https://github.com/python/cpython/issues/88261


File: python.info,  Node: Optimizations<3>,  Next: Faster CPython,  Prev: Improved Modules<2>,  Up: What’s New In Python 3 11

1.4.8 Optimizations
-------------------

This section covers specific optimizations independent of the *note
Faster CPython: 7be. project, which is covered in its own section.

   * The compiler now optimizes simple *note printf-style % formatting:
     8dc. on string literals containing only the format codes ‘%s’, ‘%r’
     and ‘%a’ and makes it as fast as a corresponding *note f-string:
     66b. expression.  (Contributed by Serhiy Storchaka in
     bpo-28307(1).)

   * Integer division (‘//’) is better tuned for optimization by
     compilers.  It is now around 20% faster on x86-64 when dividing an
     *note int: 19b. by a value smaller than ‘2**30’.  (Contributed by
     Gregory P. Smith and Tim Peters in gh-90564(2).)

   * *note sum(): 696. is now nearly 30% faster for integers smaller
     than ‘2**30’.  (Contributed by Stefan Behnel in gh-68264(3).)

   * Resizing lists is streamlined for the common case, speeding up
     *note list.append(): 8dd. by ≈15% and simple *note list
     comprehension: 8de.s by up to 20-30% (Contributed by Dennis Sweeney
     in gh-91165(4).)

   * Dictionaries don’t store hash values when all keys are Unicode
     objects, decreasing *note dict: 183. size.  For example,
     ‘sys.getsizeof(dict.fromkeys("abcdefg"))’ is reduced from 352 bytes
     to 272 bytes (23% smaller) on 64-bit platforms.  (Contributed by
     Inada Naoki in bpo-46845(5).)

   * Using *note asyncio.DatagramProtocol: 8df. is now orders of
     magnitude faster when transferring large files over UDP, with
     speeds over 100 times higher for a ≈60 MiB file.  (Contributed by
     msoxzw in gh-91487(6).)

   * *note math: 92. functions *note comb(): 8e0. and *note perm(): 8e1.
     are now ≈10 times faster for large arguments (with a larger speedup
     for larger 'k').  (Contributed by Serhiy Storchaka in
     bpo-37295(7).)

   * The *note statistics: d7. functions *note mean(): 8e2, *note
     variance(): 8e3. and *note stdev(): 8e4. now consume iterators in
     one pass rather than converting them to a *note list: 24d. first.
     This is twice as fast and can save substantial memory.
     (Contributed by Raymond Hettinger in gh-90415(8).)

   * *note unicodedata.normalize(): 8e5. now normalizes pure-ASCII
     strings in constant time.  (Contributed by Donghee Na in
     bpo-44987(9).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28307

   (2) https://github.com/python/cpython/issues/90564

   (3) https://github.com/python/cpython/issues/68264

   (4) https://github.com/python/cpython/issues/91165

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46845

   (6) https://github.com/python/cpython/issues/91487

   (7) https://bugs.python.org/issue?@action=redirect&bpo=37295

   (8) https://github.com/python/cpython/issues/90415

   (9) https://bugs.python.org/issue?@action=redirect&bpo=44987


File: python.info,  Node: Faster CPython,  Next: CPython bytecode changes<2>,  Prev: Optimizations<3>,  Up: What’s New In Python 3 11

1.4.9 Faster CPython
--------------------

CPython 3.11 is an average of 25% faster(1) than CPython 3.10 as
measured with the pyperformance(2) benchmark suite, when compiled with
GCC on Ubuntu Linux.  Depending on your workload, the overall speedup
could be 10-60%.

This project focuses on two major areas in Python: *note Faster Startup:
8e7. and *note Faster Runtime: 8e8.  Optimizations not covered by this
project are listed separately under *note Optimizations: 8db.

* Menu:

* Faster Startup::
* Faster Runtime::
* Misc::
* FAQ::
* About::

   ---------- Footnotes ----------

   (1) https://github.com/faster-cpython/ideas#published-results

   (2) https://github.com/python/pyperformance


File: python.info,  Node: Faster Startup,  Next: Faster Runtime,  Up: Faster CPython

1.4.9.1 Faster Startup
......................

* Menu:

* Frozen imports / Static code objects::


File: python.info,  Node: Frozen imports / Static code objects,  Up: Faster Startup

1.4.9.2 Frozen imports / Static code objects
............................................

Python caches *note bytecode: 4ab. in the *note __pycache__: 8ec.
directory to speed up module loading.

Previously in 3.10, Python module execution looked like this:

     Read __pycache__ -> Unmarshal -> Heap allocated code object -> Evaluate

In Python 3.11, the core modules essential for Python startup are
«frozen».  This means that their *note Code Objects: 7d3. (and bytecode)
are statically allocated by the interpreter.  This reduces the steps in
module execution process to:

     Statically allocated code object -> Evaluate

Interpreter startup is now 10-15% faster in Python 3.11.  This has a big
impact for short-running programs using Python.

(Contributed by Eric Snow, Guido van Rossum and Kumar Aditya in many
issues.)


File: python.info,  Node: Faster Runtime,  Next: Misc,  Prev: Faster Startup,  Up: Faster CPython

1.4.9.3 Faster Runtime
......................

* Menu:

* Cheaper, lazy Python frames: Cheaper lazy Python frames.
* Inlined Python function calls::
* PEP 659; Specializing Adaptive Interpreter: PEP 659 Specializing Adaptive Interpreter.


File: python.info,  Node: Cheaper lazy Python frames,  Next: Inlined Python function calls,  Up: Faster Runtime

1.4.9.4 Cheaper, lazy Python frames
...................................

Python frames, holding execution information, are created whenever
Python calls a Python function.  The following are new frame
optimizations:

   - Streamlined the frame creation process.

   - Avoided memory allocation by generously re-using frame space on the
     C stack.

   - Streamlined the internal frame struct to contain only essential
     information.  Frames previously held extra debugging and memory
     management information.

Old-style *note frame objects: 8f0. are now created only when requested
by debuggers or by Python introspection functions such as *note
sys._getframe(): 8f1. and *note inspect.currentframe(): 8f2.  For most
user code, no frame objects are created at all.  As a result, nearly all
Python functions calls have sped up significantly.  We measured a 3-7%
speedup in pyperformance.

(Contributed by Mark Shannon in bpo-44590(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44590


File: python.info,  Node: Inlined Python function calls,  Next: PEP 659 Specializing Adaptive Interpreter,  Prev: Cheaper lazy Python frames,  Up: Faster Runtime

1.4.9.5 Inlined Python function calls
.....................................

During a Python function call, Python will call an evaluating C function
to interpret that function’s code.  This effectively limits pure Python
recursion to what’s safe for the C stack.

In 3.11, when CPython detects Python code calling another Python
function, it sets up a new frame, and «jumps» to the new code inside the
new frame.  This avoids calling the C interpreting function altogether.

Most Python function calls now consume no C stack space, speeding them
up.  In simple recursive functions like fibonacci or factorial, we
observed a 1.7x speedup.  This also means recursive functions can
recurse significantly deeper (if the user increases the recursion limit
with *note sys.setrecursionlimit(): 6eb.).  We measured a 1-3%
improvement in pyperformance.

(Contributed by Pablo Galindo and Mark Shannon in bpo-45256(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45256


File: python.info,  Node: PEP 659 Specializing Adaptive Interpreter,  Prev: Inlined Python function calls,  Up: Faster Runtime

1.4.9.6 PEP 659: Specializing Adaptive Interpreter
..................................................

PEP 659(1) is one of the key parts of the Faster CPython project.  The
general idea is that while Python is a dynamic language, most code has
regions where objects and types rarely change.  This concept is known as
'type stability'.

At runtime, Python will try to look for common patterns and type
stability in the executing code.  Python will then replace the current
operation with a more specialized one.  This specialized operation uses
fast paths available only to those use cases/types, which generally
outperform their generic counterparts.  This also brings in another
concept called 'inline caching', where Python caches the results of
expensive operations directly in the *note bytecode: 4ab.

The specializer will also combine certain common instruction pairs into
one superinstruction, reducing the overhead during execution.

Python will only specialize when it sees code that is «hot» (executed
multiple times).  This prevents Python from wasting time on run-once
code.  Python can also de-specialize when code is too dynamic or when
the use changes.  Specialization is attempted periodically, and
specialization attempts are not too expensive, allowing specialization
to adapt to new circumstances.

(PEP written by Mark Shannon, with ideas inspired by Stefan Brunthaler.
See PEP 659(2) for more information.  Implementation by Mark Shannon and
Brandt Bucher, with additional help from Irit Katriel and Dennis
Sweeney.)

Operation           Form                     Specialization                                              Operation speedup (up   Contributor(s)
                                                                                                         to)                     
                                                                                                         
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                 
Binary operations   ‘x + x’                  Binary add, multiply and subtract for common types such     10%                     Mark Shannon, Donghee
                                             as *note int: 19b, *note float: 196. and *note str: 169.                            Na, Brandt Bucher,
                    ‘x - x’                  take custom fast paths for their underlying types.                                  Dennis Sweeney
                                                                                                                                 
                    ‘x * x’
                    
                                                                                                                                 
Subscript           ‘a[i]’                   Subscripting container types such as *note list: 24d,       10-25%                  Irit Katriel, Mark
                                             *note tuple: 614. and *note dict: 183. directly index the                           Shannon
                                             underlying data structures.                                                         
                                             
                                             Subscripting custom *note __getitem__(): 588. is also
                                             inlined similar to
                                             *note Inlined Python function calls: 8f3.
                                             
                                                                                                                                 
Store subscript     ‘a[i] = z’               Similar to subscripting specialization above.               10-25%                  Dennis Sweeney
                                                                                                                                 
                                                                                                                                 
Calls               ‘f(arg)’                 Calls to common builtin (C) functions and types such as     20%                     Mark Shannon, Ken Jin
                                             *note len(): 841. and *note str: 169. directly call their                           
                    ‘C(arg)’                 underlying C version.  This avoids going through the
                                             internal calling convention.
                                             
                                                                                                                                 
Load global         ‘print’                  The object’s index in the globals/builtins namespace is     (3)                     Mark Shannon
variable                                     cached.  Loading globals and builtins require zero                                  
                    ‘len’                    namespace lookups.
                                             
                                                                                                                                 
Load attribute      ‘o.attr’                 Similar to loading global variables.  The attribute’s       (4)                     Mark Shannon
                                             index inside the class/object’s namespace is cached.  In                            
                                             most cases, attribute loading will require zero namespace
                                             lookups.
                                             
                                                                                                                                 
Load methods for    ‘o.meth()’               The actual address of the method is cached.  Method         10-20%                  Ken Jin, Mark Shannon
call                                         loading now has no namespace lookups – even for classes                             
                                             with long inheritance chains.
                                             
                                                                                                                                 
Store attribute     ‘o.attr = z’             Similar to load attribute optimization.                     2% in pyperformance     Mark Shannon
                                                                                                                                 
                                                                                                                                 
Unpack Sequence     ‘*seq’                   Specialized for common containers such as                   8%                      Brandt Bucher
                                             *note list: 24d. and *note tuple: 614.  Avoids internal                             
                                             calling convention.
                                             

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0659/

   (2) https://peps.python.org/pep-0659/

   (3) A similar optimization already existed since Python 3.8.  3.11
specializes for more forms and reduces some overhead.

   (4) A similar optimization already existed since Python 3.10.  3.11
specializes for more forms.  Furthermore, all attribute loads should be
sped up by bpo-45947
(https://bugs.python.org/issue?@action=redirect&bpo=45947).


File: python.info,  Node: Misc,  Next: FAQ,  Prev: Faster Runtime,  Up: Faster CPython

1.4.9.7 Misc
............

   * Objects now require less memory due to lazily created object
     namespaces.  Their namespace dictionaries now also share keys more
     freely.  (Contributed Mark Shannon in bpo-45340(1) and
     bpo-40116(2).)

   * «Zero-cost» exceptions are implemented, eliminating the cost of
     *note try: 8f9. statements when no exception is raised.
     (Contributed by Mark Shannon in bpo-40222(3).)

   * A more concise representation of exceptions in the interpreter
     reduced the time required for catching an exception by about 10%.
     (Contributed by Irit Katriel in bpo-45711(4).)

   * *note re: be.’s regular expression matching engine has been
     partially refactored, and now uses computed gotos (or «threaded
     code») on supported platforms.  As a result, Python 3.11 executes
     the pyperformance regular expression benchmarks(5) up to 10% faster
     than Python 3.10.  (Contributed by Brandt Bucher in gh-91404(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45340

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40116

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40222

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45711

   (5) https://pyperformance.readthedocs.io/benchmarks.html#regex-dna

   (6) https://github.com/python/cpython/issues/91404


File: python.info,  Node: FAQ,  Next: About,  Prev: Misc,  Up: Faster CPython

1.4.9.8 FAQ
...........

* Menu:

* How should I write my code to utilize these speedups?::
* Will CPython 3.11 use more memory?: Will CPython 3 11 use more memory?.
* I don’t see any speedups in my workload. Why?: I don’t see any speedups in my workload Why?.
* Is there a JIT compiler?::


File: python.info,  Node: How should I write my code to utilize these speedups?,  Next: Will CPython 3 11 use more memory?,  Up: FAQ

1.4.9.9 How should I write my code to utilize these speedups?
.............................................................

Write Pythonic code that follows common best practices; you don’t have
to change your code.  The Faster CPython project optimizes for common
code patterns we observe.


File: python.info,  Node: Will CPython 3 11 use more memory?,  Next: I don’t see any speedups in my workload Why?,  Prev: How should I write my code to utilize these speedups?,  Up: FAQ

1.4.9.10 Will CPython 3.11 use more memory?
...........................................

Maybe not; we don’t expect memory use to exceed 20% higher than 3.10.
This is offset by memory optimizations for frame objects and object
dictionaries as mentioned above.


File: python.info,  Node: I don’t see any speedups in my workload Why?,  Next: Is there a JIT compiler?,  Prev: Will CPython 3 11 use more memory?,  Up: FAQ

1.4.9.11 I don’t see any speedups in my workload. Why?
......................................................

Certain code won’t have noticeable benefits.  If your code spends most
of its time on I/O operations, or already does most of its computation
in a C extension library like NumPy, there won’t be significant
speedups.  This project currently benefits pure-Python workloads the
most.

Furthermore, the pyperformance figures are a geometric mean.  Even
within the pyperformance benchmarks, certain benchmarks have slowed down
slightly, while others have sped up by nearly 2x!


File: python.info,  Node: Is there a JIT compiler?,  Prev: I don’t see any speedups in my workload Why?,  Up: FAQ

1.4.9.12 Is there a JIT compiler?
.................................

No.  We’re still exploring other optimizations.


File: python.info,  Node: About,  Prev: FAQ,  Up: Faster CPython

1.4.9.13 About
..............

Faster CPython explores optimizations for *note CPython: 906.  The main
team is funded by Microsoft to work on this full-time.  Pablo Galindo
Salgado is also funded by Bloomberg LP to work on the project part-time.
Finally, many contributors are volunteers from the community.


File: python.info,  Node: CPython bytecode changes<2>,  Next: Deprecated<2>,  Prev: Faster CPython,  Up: What’s New In Python 3 11

1.4.10 CPython bytecode changes
-------------------------------

The bytecode now contains inline cache entries, which take the form of
the newly-added *note CACHE: 909. instructions.  Many opcodes expect to
be followed by an exact number of caches, and instruct the interpreter
to skip over them at runtime.  Populated caches can look like arbitrary
instructions, so great care should be taken when reading or modifying
raw, adaptive bytecode containing quickened data.

* Menu:

* New opcodes::
* Replaced opcodes::
* Changed/removed opcodes::


File: python.info,  Node: New opcodes,  Next: Replaced opcodes,  Up: CPython bytecode changes<2>

1.4.10.1 New opcodes
....................

   * ‘ASYNC_GEN_WRAP’, *note RETURN_GENERATOR: 90c. and *note SEND: 90d,
     used in generators and co-routines.

   * *note COPY_FREE_VARS: 90e, which avoids needing special caller-side
     code for closures.

   * *note JUMP_BACKWARD_NO_INTERRUPT: 90f, for use in certain loops
     where handling interrupts is undesirable.

   * *note MAKE_CELL: 910, to create *note Cell Objects: 911.

   * *note CHECK_EG_MATCH: 912. and ‘PREP_RERAISE_STAR’, to handle the
     *note new exception groups and except*: 7bf. added in PEP 654(1).

   * *note PUSH_EXC_INFO: 913, for use in exception handlers.

   * *note RESUME: 5bb, a no-op, for internal tracing, debugging and
     optimization checks.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0654/


File: python.info,  Node: Replaced opcodes,  Next: Changed/removed opcodes,  Prev: New opcodes,  Up: CPython bytecode changes<2>

1.4.10.2 Replaced opcodes
.........................

Replaced Opcode(s)                       New Opcode(s)                            Notes
                                                                                  
--------------------------------------------------------------------------------------------------------------------------------
                                                                                  
     ‘BINARY_*’                          *note BINARY_OP: 366.                    Replaced all numeric binary/in-place
     ‘INPLACE_*’                                                                  opcodes with a single opcode
                                                                                  
                                                                                  
     ‘CALL_FUNCTION’                          *note CALL: 916.                    Decouples argument shifting for methods
     ‘CALL_FUNCTION_KW’                       ‘KW_NAMES’                          from handling of keyword arguments; allows
     ‘CALL_METHOD’                            ‘PRECALL’                           better specialization of calls
                                              *note PUSH_NULL: 917.               
                                         
                                                                                  
     ‘DUP_TOP’                                *note COPY: 918.                    Stack manipulation instructions
     ‘DUP_TOP_TWO’                            *note SWAP: 919.                    
     ‘ROT_TWO’                           
     ‘ROT_THREE’
     ‘ROT_FOUR’
     ‘ROT_N’

     ‘JUMP_IF_NOT_EXC_MATCH’                  *note CHECK_EXC_MATCH: 91a.         Now performs check but doesn’t jump
                                                                                  
                                                                                  
     ‘JUMP_ABSOLUTE’                          *note JUMP_BACKWARD: 91b.           See (1); ‘TRUE’, ‘FALSE’, ‘NONE’ and
     ‘POP_JUMP_IF_FALSE’                      ‘POP_JUMP_BACKWARD_IF_*’            ‘NOT_NONE’ variants for each direction
     ‘POP_JUMP_IF_TRUE’                       ‘POP_JUMP_FORWARD_IF_*’             
                                         
                                                                                  
     ‘SETUP_WITH’                        ‘BEFORE_WITH’                            *note with: 186. block setup
     ‘SETUP_ASYNC_WITH’                                                           

   ---------- Footnotes ----------

   (1) All jump opcodes are now relative, including the existing
‘JUMP_IF_TRUE_OR_POP’ and ‘JUMP_IF_FALSE_OR_POP’.  The argument is now
an offset from the current instruction rather than an absolute location.


File: python.info,  Node: Changed/removed opcodes,  Prev: Replaced opcodes,  Up: CPython bytecode changes<2>

1.4.10.3 Changed/removed opcodes
................................

   * Changed *note MATCH_CLASS: 920. and *note MATCH_KEYS: 921. to no
     longer push an additional boolean value to indicate
     success/failure.  Instead, ‘None’ is pushed on failure in place of
     the tuple of extracted values.

   * Changed opcodes that work with exceptions to reflect them now being
     represented as one item on the stack instead of three (see
     gh-89874(1)).

   * Removed ‘COPY_DICT_WITHOUT_KEYS’, ‘GEN_START’, ‘POP_BLOCK’,
     ‘SETUP_FINALLY’ and ‘YIELD_FROM’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89874


File: python.info,  Node: Deprecated<2>,  Next: Pending Removal in Python 3 12,  Prev: CPython bytecode changes<2>,  Up: What’s New In Python 3 11

1.4.11 Deprecated
-----------------

This section lists Python APIs that have been deprecated in Python 3.11.

Deprecated C APIs are *note listed separately: 925.
* Menu:

* Language/Builtins::
* Modules::
* Standard Library::


File: python.info,  Node: Language/Builtins,  Next: Modules,  Up: Deprecated<2>

1.4.11.1 Language/Builtins
..........................

   * Chaining *note classmethod: 48f. descriptors (introduced in
     bpo-19072(1)) is now deprecated.  It can no longer be used to wrap
     other descriptors such as *note property: 4b4.  The core design of
     this feature was flawed and caused a number of downstream problems.
     To «pass-through» a *note classmethod: 48f, consider using the
     ‘__wrapped__’ attribute that was added in Python 3.10.
     (Contributed by Raymond Hettinger in gh-89519(2).)

   * Octal escapes in string and bytes literals with values larger than
     ‘0o377’ (255 in decimal) now produce a *note DeprecationWarning:
     1a3.  In a future Python version, they will raise a *note
     SyntaxWarning: 1ae. and eventually a *note SyntaxError: 18e.
     (Contributed by Serhiy Storchaka in gh-81548(3).)

   * The delegation of *note int(): 19b. to *note __trunc__(): 19c. is
     now deprecated.  Calling ‘int(a)’ when ‘type(a)’ implements
     ‘__trunc__()’ but not *note __int__(): 19d. or *note __index__():
     19e. now raises a *note DeprecationWarning: 1a3.  (Contributed by
     Zackery Spytz in bpo-44977(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19072

   (2) https://github.com/python/cpython/issues/89519

   (3) https://github.com/python/cpython/issues/81548

   (4) https://bugs.python.org/issue?@action=redirect&bpo=44977


File: python.info,  Node: Modules,  Next: Standard Library,  Prev: Language/Builtins,  Up: Deprecated<2>

1.4.11.2 Modules
................

   * PEP 594(1) led to the deprecations of the following modules slated
     for removal in Python 3.13:

     ‘aifc’                    ‘chunk’                   ‘msilib’                  ‘pipes’                   ‘telnetlib’
                                                                                                             
                                                                                                             
     ‘audioop’                 ‘crypt’                   ‘nis’                     ‘sndhdr’                  ‘uu’
                                                                                                             
                                                                                                             
     ‘cgi’                     ‘imghdr’                  ‘nntplib’                 ‘spwd’                    ‘xdrlib’
                                                                                                             
                                                                                                             
     ‘cgitb’                   ‘mailcap’                 ‘ossaudiodev’             ‘sunau’
                                                                                   

     (Contributed by Brett Cannon in bpo-47061(2) and Victor Stinner in
     gh-68966(3).)

   * The ‘asynchat’, ‘asyncore’ and ‘smtpd’ modules have been deprecated
     since at least Python 3.6.  Their documentation and deprecation
     warnings have now been updated to note they will be removed in
     Python 3.12.  (Contributed by Hugo van Kemenade in bpo-47022(4).)

   * The ‘lib2to3’ package and ‘2to3’ tool are now deprecated and may
     not be able to parse Python 3.10 or newer.  See PEP 617(5),
     introducing the new PEG parser, for details.  (Contributed by
     Victor Stinner in bpo-40360(6).)

   * Undocumented modules ‘sre_compile’, ‘sre_constants’ and ‘sre_parse’
     are now deprecated.  (Contributed by Serhiy Storchaka in
     bpo-47152(7).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=47061

   (3) https://github.com/python/cpython/issues/68966

   (4) https://bugs.python.org/issue?@action=redirect&bpo=47022

   (5) https://peps.python.org/pep-0617/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40360

   (7) https://bugs.python.org/issue?@action=redirect&bpo=47152


File: python.info,  Node: Standard Library,  Prev: Modules,  Up: Deprecated<2>

1.4.11.3 Standard Library
.........................

   * The following have been deprecated in *note configparser: 26. since
     Python 3.2.  Their deprecation warnings have now been updated to
     note they will be removed in Python 3.12:

        * the ‘configparser.SafeConfigParser’ class

        * the ‘configparser.ParsingError.filename’ property

        * the ‘configparser.RawConfigParser.readfp()’ method

     (Contributed by Hugo van Kemenade in bpo-45173(1).)

   * ‘configparser.LegacyInterpolation’ has been deprecated in the
     docstring since Python 3.2, and is not listed in the *note
     configparser: 26. documentation.  It now emits a *note
     DeprecationWarning: 1a3. and will be removed in Python 3.13.  Use
     *note configparser.BasicInterpolation: 92d. or *note
     configparser.ExtendedInterpolation: 92e. instead.  (Contributed by
     Hugo van Kemenade in bpo-46607(2).)

   * The older set of *note importlib.resources: 7f. functions were
     deprecated in favor of the replacements added in Python 3.9 and
     will be removed in a future Python version, due to not supporting
     resources located within package subdirectories:

        * ‘importlib.resources.contents()’

        * ‘importlib.resources.is_resource()’

        * ‘importlib.resources.open_binary()’

        * ‘importlib.resources.open_text()’

        * ‘importlib.resources.read_binary()’

        * ‘importlib.resources.read_text()’

        * ‘importlib.resources.path()’

   * The *note locale.getdefaultlocale(): 326. function is deprecated
     and will be removed in Python 3.15.  Use *note locale.setlocale():
     328, *note locale.getpreferredencoding(False): 75d. and *note
     locale.getlocale(): 327. functions instead.  (Contributed by Victor
     Stinner in gh-90817(3).)

   * The ‘locale.resetlocale()’ function is deprecated and will be
     removed in Python 3.13.  Use ‘locale.setlocale(locale.LC_ALL, "")’
     instead.  (Contributed by Victor Stinner in gh-90817(4).)

   * Stricter rules will now be applied for numerical group references
     and group names in *note regular expressions: 92f.  Only sequences
     of ASCII digits will now be accepted as a numerical reference, and
     the group name in *note bytes: 192. patterns and replacement
     strings can only contain ASCII letters, digits and underscores.
     For now, a deprecation warning is raised for syntax violating these
     rules.  (Contributed by Serhiy Storchaka in gh-91760(5).)

   * In the *note re: be. module, the ‘re.template()’ function and the
     corresponding ‘re.TEMPLATE’ and ‘re.T’ flags are deprecated, as
     they were undocumented and lacked an obvious purpose.  They will be
     removed in Python 3.13.  (Contributed by Serhiy Storchaka and Miro
     Hrončok in gh-92728(6).)

   * ‘turtle.settiltangle()’ has been deprecated since Python 3.1; it
     now emits a deprecation warning and will be removed in Python 3.13.
     Use *note turtle.tiltangle(): 930. instead (it was earlier
     incorrectly marked as deprecated, and its docstring is now
     corrected).  (Contributed by Hugo van Kemenade in bpo-45837(7).)

   * *note typing.Text: 360, which exists solely to provide
     compatibility support between Python 2 and Python 3 code, is now
     deprecated.  Its removal is currently unplanned, but users are
     encouraged to use *note str: 169. instead wherever possible.
     (Contributed by Alex Waygood in gh-92332(8).)

   * The keyword argument syntax for constructing *note
     typing.TypedDict: 332. types is now deprecated.  Support will be
     removed in Python 3.13.  (Contributed by Jingchen Ye in
     gh-90224(9).)

   * ‘webbrowser.MacOSX’ is deprecated and will be removed in Python
     3.13.  It is untested, undocumented, and not used by *note
     webbrowser: 11b. itself.  (Contributed by Donghee Na in
     bpo-42255(10).)

   * The behavior of returning a value from a *note TestCase: 2b3. and
     *note IsolatedAsyncioTestCase: 361. test methods (other than the
     default ‘None’ value) is now deprecated.

   * Deprecated the following not-formally-documented *note unittest:
     10c. functions, scheduled for removal in Python 3.13:

        * ‘unittest.findTestCases()’

        * ‘unittest.makeSuite()’

        * ‘unittest.getTestCaseNames()’

     Use *note TestLoader: 593. methods instead:

        * *note unittest.TestLoader.loadTestsFromModule(): 594.

        * *note unittest.TestLoader.loadTestsFromTestCase(): 595.

        * *note unittest.TestLoader.getTestCaseNames(): 596.

     (Contributed by Erlend E. Aasland in bpo-5846(11).)

   * ‘unittest.TestProgram.usageExit()’ is marked deprecated, to be
     removed in 3.13.  (Contributed by Carlos Damázio in gh-67048(12).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45173

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46607

   (3) https://github.com/python/cpython/issues/90817

   (4) https://github.com/python/cpython/issues/90817

   (5) https://github.com/python/cpython/issues/91760

   (6) https://github.com/python/cpython/issues/92728

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45837

   (8) https://github.com/python/cpython/issues/92332

   (9) https://github.com/python/cpython/issues/90224

   (10) https://bugs.python.org/issue?@action=redirect&bpo=42255

   (11) https://bugs.python.org/issue?@action=redirect&bpo=5846

   (12) https://github.com/python/cpython/issues/67048


File: python.info,  Node: Pending Removal in Python 3 12,  Next: Removed<2>,  Prev: Deprecated<2>,  Up: What’s New In Python 3 11

1.4.12 Pending Removal in Python 3.12
-------------------------------------

The following Python APIs have been deprecated in earlier Python
releases, and will be removed in Python 3.12.

C APIs pending removal are *note listed separately: 934.

   * The ‘asynchat’ module

   * The ‘asyncore’ module

   * The *note entire distutils package: 935.

   * The ‘imp’ module

   * The *note typing.io: 238. namespace

   * The *note typing.re: 936. namespace

   * ‘cgi.log()’

   * ‘importlib.find_loader()’

   * ‘importlib.abc.Loader.module_repr()’

   * ‘importlib.abc.MetaPathFinder.find_module()’

   * ‘importlib.abc.PathEntryFinder.find_loader()’

   * ‘importlib.abc.PathEntryFinder.find_module()’

   * ‘importlib.machinery.BuiltinImporter.find_module()’

   * ‘importlib.machinery.BuiltinLoader.module_repr()’

   * ‘importlib.machinery.FileFinder.find_loader()’

   * ‘importlib.machinery.FileFinder.find_module()’

   * ‘importlib.machinery.FrozenImporter.find_module()’

   * ‘importlib.machinery.FrozenLoader.module_repr()’

   * ‘importlib.machinery.PathFinder.find_module()’

   * ‘importlib.machinery.WindowsRegistryFinder.find_module()’

   * ‘importlib.util.module_for_loader()’

   * ‘importlib.util.set_loader_wrapper()’

   * ‘importlib.util.set_package_wrapper()’

   * ‘pkgutil.ImpImporter’

   * ‘pkgutil.ImpLoader’

   * ‘pathlib.Path.link_to()’

   * ‘sqlite3.enable_shared_cache()’

   * ‘sqlite3.OptimizedUnicode()’

   * ‘PYTHONTHREADDEBUG’ environment variable

   * The following deprecated aliases in *note unittest: 10c.:

          Deprecated alias                 Method Name                         Deprecated in
                                                                               
          -----------------------------------------------------------------------------------------
                                                                               
          ‘failUnless’                     *note assertTrue(): 74b.            3.1
                                                                               
                                                                               
          ‘failIf’                         *note assertFalse(): 74c.           3.1
                                                                               
                                                                               
          ‘failUnlessEqual’                *note assertEqual(): 74d.           3.1
                                                                               
                                                                               
          ‘failIfEqual’                    *note assertNotEqual(): 74e.        3.1
                                                                               
                                                                               
          ‘failUnlessAlmostEqual’          *note assertAlmostEqual(): 74f.     3.1
                                                                               
                                                                               
          ‘failIfAlmostEqual’              *note assertNotAlmostEqual(): 750.  3.1
                                                                               
                                                                               
          ‘failUnlessRaises’               *note assertRaises(): 751.          3.1
                                                                               
                                                                               
          ‘assert_’                        *note assertTrue(): 74b.            3.2
                                                                               
                                                                               
          ‘assertEquals’                   *note assertEqual(): 74d.           3.2
                                                                               
                                                                               
          ‘assertNotEquals’                *note assertNotEqual(): 74e.        3.2
                                                                               
                                                                               
          ‘assertAlmostEquals’             *note assertAlmostEqual(): 74f.     3.2
                                                                               
                                                                               
          ‘assertNotAlmostEquals’          *note assertNotAlmostEqual(): 750.  3.2
                                                                               
                                                                               
          ‘assertRegexpMatches’            *note assertRegex(): 752.           3.2
                                                                               
                                                                               
          ‘assertRaisesRegexp’             *note assertRaisesRegex(): 753.     3.2
                                                                               
                                                                               
          ‘assertNotRegexpMatches’         *note assertNotRegex(): 754.        3.5
                                                                               


File: python.info,  Node: Removed<2>,  Next: Porting to Python 3 11,  Prev: Pending Removal in Python 3 12,  Up: What’s New In Python 3 11

1.4.13 Removed
--------------

This section lists Python APIs that have been removed in Python 3.11.

Removed C APIs are *note listed separately: 93a.

   * Removed the ‘@asyncio.coroutine()’ *note decorator: 93b. enabling
     legacy generator-based coroutines to be compatible with *note
     async: 93c. / *note await: 18d. code.  The function has been
     deprecated since Python 3.8 and the removal was initially scheduled
     for Python 3.10.  Use *note async def: 7ee. instead.  (Contributed
     by Illia Volochii in bpo-43216(1).)

   * Removed ‘asyncio.coroutines.CoroWrapper’ used for wrapping legacy
     generator-based coroutine objects in the debug mode.  (Contributed
     by Illia Volochii in bpo-43216(2).)

   * Due to significant security concerns, the 'reuse_address' parameter
     of *note asyncio.loop.create_datagram_endpoint(): 93d, disabled in
     Python 3.9, is now entirely removed.  This is because of the
     behavior of the socket option ‘SO_REUSEADDR’ in UDP. (Contributed
     by Hugo van Kemenade in bpo-45129(3).)

   * Removed the ‘binhex’ module, deprecated in Python 3.9.  Also
     removed the related, similarly-deprecated *note binascii: 11.
     functions:

        * ‘binascii.a2b_hqx()’

        * ‘binascii.b2a_hqx()’

        * ‘binascii.rlecode_hqx()’

        * ‘binascii.rldecode_hqx()’

     The *note binascii.crc_hqx(): 93e. function remains available.

     (Contributed by Victor Stinner in bpo-45085(4).)

   * Removed the ‘distutils’ ‘bdist_msi’ command deprecated in Python
     3.9.  Use ‘bdist_wheel’ (wheel packages) instead.  (Contributed by
     Hugo van Kemenade in bpo-45124(5).)

   * Removed the *note __getitem__(): 588. methods of *note
     xml.dom.pulldom.DOMEventStream: 93f, *note
     wsgiref.util.FileWrapper: 940. and *note fileinput.FileInput: 941,
     deprecated since Python 3.9.  (Contributed by Hugo van Kemenade in
     bpo-45132(6).)

   * Removed the deprecated *note gettext: 67. functions ‘lgettext()’,
     ‘ldgettext()’, ‘lngettext()’ and ‘ldngettext()’.  Also removed the
     ‘bind_textdomain_codeset()’ function, the
     ‘NullTranslations.output_charset()’ and
     ‘NullTranslations.set_output_charset()’ methods, and the 'codeset'
     parameter of ‘translation()’ and ‘install()’, since they are only
     used for the ‘l*gettext()’ functions.  (Contributed by Donghee Na
     and Serhiy Storchaka in bpo-44235(7).)

   * Removed from the *note inspect: 82. module:

        * The ‘getargspec()’ function, deprecated since Python 3.0; use
          *note inspect.signature(): 22f. or *note
          inspect.getfullargspec(): 942. instead.

        * The ‘formatargspec()’ function, deprecated since Python 3.5;
          use the *note inspect.signature(): 22f. function or the *note
          inspect.Signature: 4e4. object directly.

        * The undocumented ‘Signature.from_builtin()’ and
          ‘Signature.from_function()’ methods, deprecated since Python
          3.5; use the *note Signature.from_callable(): 943. method
          instead.

     (Contributed by Hugo van Kemenade in bpo-45320(8).)

   * Removed the *note __class_getitem__(): 944. method from *note
     pathlib.PurePath: 6ce, because it was not used and added by mistake
     in previous versions.  (Contributed by Nikita Sobolev in
     bpo-46483(9).)

   * Removed the ‘MailmanProxy’ class in the ‘smtpd’ module, as it is
     unusable without the external ‘mailman’ package.  (Contributed by
     Donghee Na in bpo-35800(10).)

   * Removed the deprecated ‘split()’ method of ‘_tkinter.TkappType’.
     (Contributed by Erlend E. Aasland in bpo-38371(11).)

   * Removed namespace package support from *note unittest: 10c.
     discovery.  It was introduced in Python 3.4 but has been broken
     since Python 3.7.  (Contributed by Inada Naoki in bpo-23882(12).)

   * Removed the undocumented private ‘float.__set_format__()’ method,
     previously known as ‘float.__setformat__()’ in Python 3.7.  Its
     docstring said: «You probably don’t want to use this function.  It
     exists mainly to be used in Python’s test suite.» (Contributed by
     Victor Stinner in bpo-46852(13).)

   * The ‘--experimental-isolated-subinterpreters’ configure flag (and
     corresponding ‘EXPERIMENTAL_ISOLATED_SUBINTERPRETERS’ macro) have
     been removed.

   * Pynche(14) — The Pythonically Natural Color and Hue Editor — has
     been moved out of ‘Tools/scripts’ and is being developed
     independently(15) from the Python source tree.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43216

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43216

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45129

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45085

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45124

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45132

   (7) https://bugs.python.org/issue?@action=redirect&bpo=44235

   (8) https://bugs.python.org/issue?@action=redirect&bpo=45320

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46483

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35800

   (11) https://bugs.python.org/issue?@action=redirect&bpo=38371

   (12) https://bugs.python.org/issue?@action=redirect&bpo=23882

   (13) https://bugs.python.org/issue?@action=redirect&bpo=46852

   (14) https://pypi.org/project/Pynche/

   (15) https://gitlab.com/warsaw/pynche/-/tree/main


File: python.info,  Node: Porting to Python 3 11,  Next: Build Changes<2>,  Prev: Removed<2>,  Up: What’s New In Python 3 11

1.4.14 Porting to Python 3.11
-----------------------------

This section lists previously described changes and other bugfixes in
the Python API that may require changes to your Python code.

Porting notes for the C API are *note listed separately: 948.

   * *note open(): 316, *note io.open(): 741, *note codecs.open(): 315.
     and *note fileinput.FileInput: 941. no longer accept ‘'U'’
     («universal newline») in the file mode.  In Python 3, «universal
     newline» mode is used by default whenever a file is opened in text
     mode, and the ‘'U'’ flag has been deprecated since Python 3.3.  The
     *note newline parameter: 949. to these functions controls how
     universal newlines work.  (Contributed by Victor Stinner in
     bpo-37330(1).)

   * *note ast.AST: 4c4. node positions are now validated when provided
     to *note compile(): 4b2. and other related functions.  If invalid
     positions are detected, a *note ValueError: 2ec. will be raised.
     (Contributed by Pablo Galindo in gh-93351(2))

   * Prohibited passing non-*note concurrent.futures.ThreadPoolExecutor:
     94a. executors to *note asyncio.loop.set_default_executor(): 94b.
     following a deprecation in Python 3.8.  (Contributed by Illia
     Volochii in bpo-43234(3).)

   * *note calendar: 15.: The *note calendar.LocaleTextCalendar: 94c.
     and *note calendar.LocaleHTMLCalendar: 94d. classes now use *note
     locale.getlocale(): 327, instead of using *note
     locale.getdefaultlocale(): 326, if no locale is specified.
     (Contributed by Victor Stinner in bpo-46659(4).)

   * The *note pdb: aa. module now reads the ‘.pdbrc’ configuration file
     with the ‘'UTF-8'’ encoding.  (Contributed by Srinivas Reddy
     Thatiparthy (శ్రీనివాస్ రెడ్డి తాటిపర్తి) in bpo-41137(5).)

   * The 'population' parameter of *note random.sample(): 94e. must be a
     sequence, and automatic conversion of *note set: 184.s to *note
     list: 24d.s is no longer supported.  Also, if the sample size is
     larger than the population size, a *note ValueError: 2ec. is
     raised.  (Contributed by Raymond Hettinger in bpo-40465(6).)

   * The 'random' optional parameter of *note random.shuffle(): 94f. was
     removed.  It was previously an arbitrary random function to use for
     the shuffle; now, *note random.random(): 950. (its previous
     default) will always be used.

   * In *note re: be. *note Regular Expression Syntax: 92f, global
     inline flags (e.g.  ‘(?i)’) can now only be used at the start of
     regular expressions.  Using them elsewhere has been deprecated
     since Python 3.6.  (Contributed by Serhiy Storchaka in
     bpo-47066(7).)

   * In the *note re: be. module, several long-standing bugs where fixed
     that, in rare cases, could cause capture groups to get the wrong
     result.  Therefore, this could change the captured output in these
     cases.  (Contributed by Ma Lin in bpo-35859(8).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37330

   (2) https://github.com/python/cpython/issues/93351

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43234

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46659

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41137

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40465

   (7) https://bugs.python.org/issue?@action=redirect&bpo=47066

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35859


File: python.info,  Node: Build Changes<2>,  Next: C API Changes<2>,  Prev: Porting to Python 3 11,  Up: What’s New In Python 3 11

1.4.15 Build Changes
--------------------

   * CPython now has PEP 11(1) Tier 3 support(2) for cross compiling to
     the WebAssembly(3) platforms Emscripten(4)
     (‘wasm32-unknown-emscripten’, i.e.  Python in the browser) and
     WebAssembly System Interface (WASI)(5) (‘wasm32-unknown-wasi’).
     The effort is inspired by previous work like Pyodide(6).  These
     platforms provide a limited subset of POSIX APIs; Python standard
     libraries features and modules related to networking, processes,
     threading, signals, mmap, and users/groups are not available or
     don’t work.  (Emscripten contributed by Christian Heimes and Ethan
     Smith in gh-84461(7) and WASI contributed by Christian Heimes in
     gh-90473(8); platforms promoted in gh-95085(9))

   * Building CPython now requires:

        * A C11(10) compiler and standard library.  Optional C11
          features(11) are not required.  (Contributed by Victor Stinner
          in bpo-46656(12), bpo-45440(13) and bpo-46640(14).)

        * Support for IEEE 754(15) floating-point numbers.  (Contributed
          by Victor Stinner in bpo-46917(16).)

   * The ‘Py_NO_NAN’ macro has been removed.  Since CPython now requires
     IEEE 754 floats, NaN values are always available.  (Contributed by
     Victor Stinner in bpo-46656(17).)

   * The *note tkinter: f6. package now requires Tcl/Tk(18) version
     8.5.12 or newer.  (Contributed by Serhiy Storchaka in
     bpo-46996(19).)

   * Build dependencies, compiler flags, and linker flags for most
     stdlib extension modules are now detected by ‘configure’.  libffi,
     libnsl, libsqlite3, zlib, bzip2, liblzma, libcrypt, Tcl/Tk, and
     uuid flags are detected by pkg-config(20) (when available).  *note
     tkinter: f6. now requires a pkg-config command to detect
     development settings for Tcl/Tk(21) headers and libraries.
     (Contributed by Christian Heimes and Erlend Egeberg Aasland in
     bpo-45847(22), bpo-45747(23), and bpo-45763(24).)

   * libpython is no longer linked against libcrypt.  (Contributed by
     Mike Gilbert in bpo-45433(25).)

   * CPython can now be built with the ThinLTO(26) option via passing
     ‘thin’ to *note -with-lto: 953, i.e.  ‘--with-lto=thin’.
     (Contributed by Donghee Na and Brett Holman in bpo-44340(27).)

   * Freelists for object structs can now be disabled.  A new
     ‘configure’ option ‘--without-freelists’ can be used to disable all
     freelists except empty tuple singleton.  (Contributed by Christian
     Heimes in bpo-45522(28).)

   * ‘Modules/Setup’ and ‘Modules/makesetup’ have been improved and tied
     up.  Extension modules can now be built through ‘makesetup’.  All
     except some test modules can be linked statically into a main
     binary or library.  (Contributed by Brett Cannon and Christian
     Heimes in bpo-45548(29), bpo-45570(30), bpo-45571(31), and
     bpo-43974(32).)

          Nota: Use the environment variables ‘TCLTK_CFLAGS’ and
          ‘TCLTK_LIBS’ to manually specify the location of Tcl/Tk
          headers and libraries.  The ‘configure’ options
          ‘--with-tcltk-includes’ and ‘--with-tcltk-libs’ have been
          removed.

          On RHEL 7 and CentOS 7 the development packages do not provide
          ‘tcl.pc’ and ‘tk.pc’; use ‘TCLTK_LIBS="-ltk8.5 -ltkstub8.5
          -ltcl8.5"’.  The directory ‘Misc/rhel7’ contains ‘.pc’ files
          and instructions on how to build Python with RHEL 7’s and
          CentOS 7’s Tcl/Tk and OpenSSL.

   * CPython will now use 30-bit digits by default for the Python *note
     int: 19b. implementation.  Previously, the default was to use
     30-bit digits on platforms with ‘SIZEOF_VOID_P >= 8’, and 15-bit
     digits otherwise.  It’s still possible to explicitly request use of
     15-bit digits via either the *note -enable-big-digits: 954. option
     to the configure script or (for Windows) the ‘PYLONG_BITS_IN_DIGIT’
     variable in ‘PC/pyconfig.h’, but this option may be removed at some
     point in the future.  (Contributed by Mark Dickinson in
     bpo-45569(33).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0011/

   (2) https://peps.python.org/pep-0011/#tier-3

   (3) https://webassembly.org/

   (4) https://emscripten.org/

   (5) https://wasi.dev/

   (6) https://pyodide.org/

   (7) https://github.com/python/cpython/issues/84461

   (8) https://github.com/python/cpython/issues/90473

   (9) https://github.com/python/cpython/issues/95085

   (10) https://en.cppreference.com/w/c/11

   (11) 
https://en.wikipedia.org/wiki/C11_(C_standard_revision)#Optional_features

   (12) https://bugs.python.org/issue?@action=redirect&bpo=46656

   (13) https://bugs.python.org/issue?@action=redirect&bpo=45440

   (14) https://bugs.python.org/issue?@action=redirect&bpo=46640

   (15) https://en.wikipedia.org/wiki/IEEE_754

   (16) https://bugs.python.org/issue?@action=redirect&bpo=46917

   (17) https://bugs.python.org/issue?@action=redirect&bpo=46656

   (18) https://www.tcl.tk

   (19) https://bugs.python.org/issue?@action=redirect&bpo=46996

   (20) https://www.freedesktop.org/wiki/Software/pkg-config/

   (21) https://www.tcl.tk

   (22) https://bugs.python.org/issue?@action=redirect&bpo=45847

   (23) https://bugs.python.org/issue?@action=redirect&bpo=45747

   (24) https://bugs.python.org/issue?@action=redirect&bpo=45763

   (25) https://bugs.python.org/issue?@action=redirect&bpo=45433

   (26) https://clang.llvm.org/docs/ThinLTO.html

   (27) https://bugs.python.org/issue?@action=redirect&bpo=44340

   (28) https://bugs.python.org/issue?@action=redirect&bpo=45522

   (29) https://bugs.python.org/issue?@action=redirect&bpo=45548

   (30) https://bugs.python.org/issue?@action=redirect&bpo=45570

   (31) https://bugs.python.org/issue?@action=redirect&bpo=45571

   (32) https://bugs.python.org/issue?@action=redirect&bpo=43974

   (33) https://bugs.python.org/issue?@action=redirect&bpo=45569


File: python.info,  Node: C API Changes<2>,  Next: Notable changes in 3 11 4,  Prev: Build Changes<2>,  Up: What’s New In Python 3 11

1.4.16 C API Changes
--------------------

* Menu:

* New Features: New Features<4>.
* Porting to Python 3.11: Porting to Python 3 11<2>.
* Deprecated: Deprecated<3>.
* Pending Removal in Python 3.12: Pending Removal in Python 3 12<2>.
* Removed: Removed<3>.


File: python.info,  Node: New Features<4>,  Next: Porting to Python 3 11<2>,  Up: C API Changes<2>

1.4.16.1 New Features
.....................

   * Add a new *note PyType_GetName(): 959. function to get type’s short
     name.  (Contributed by Hai Shi in bpo-42035(1).)

   * Add a new *note PyType_GetQualName(): 95a. function to get type’s
     qualified name.  (Contributed by Hai Shi in bpo-42035(2).)

   * Add new *note PyThreadState_EnterTracing(): 95b. and *note
     PyThreadState_LeaveTracing(): 95c. functions to the limited C API
     to suspend and resume tracing and profiling.  (Contributed by
     Victor Stinner in bpo-43760(3).)

   * Added the *note Py_Version: 381. constant which bears the same
     value as *note PY_VERSION_HEX: 382.  (Contributed by Gabriele N.
     Tornetta in bpo-43931(4).)

   * *note Py_buffer: 95d. and APIs are now part of the limited API and
     the stable ABI:

        * *note PyObject_CheckBuffer(): 639.

        * *note PyObject_GetBuffer(): 63a.

        * *note PyBuffer_GetPointer(): 95e.

        * *note PyBuffer_SizeFromFormat(): 95f.

        * *note PyBuffer_ToContiguous(): 960.

        * *note PyBuffer_FromContiguous(): 961.

        * *note PyObject_CopyData(): 962.

        * *note PyBuffer_IsContiguous(): 963.

        * *note PyBuffer_FillContiguousStrides(): 964.

        * *note PyBuffer_FillInfo(): 965.

        * *note PyBuffer_Release(): 63b.

        * *note PyMemoryView_FromBuffer(): 966.

        * *note bf_getbuffer: 967. and *note bf_releasebuffer: 968. type
          slots

     (Contributed by Christian Heimes in bpo-45459(5).)

   * Added the *note PyType_GetModuleByDef(): 635. function, used to get
     the module in which a method was defined, in cases where this
     information is not available directly (via *note PyCMethod: 969.).
     (Contributed by Petr Viktorin in bpo-46613(6).)

   * Add new functions to pack and unpack C double (serialize and
     deserialize): *note PyFloat_Pack2(): 96a, *note PyFloat_Pack4():
     96b, *note PyFloat_Pack8(): 96c, *note PyFloat_Unpack2(): 96d,
     *note PyFloat_Unpack4(): 96e. and *note PyFloat_Unpack8(): 96f.
     (Contributed by Victor Stinner in bpo-46906(7).)

   * Add new functions to get frame object attributes: *note
     PyFrame_GetBuiltins(): 970, *note PyFrame_GetGenerator(): 971,
     *note PyFrame_GetGlobals(): 972, *note PyFrame_GetLasti(): 973.

   * Added two new functions to get and set the active exception
     instance: *note PyErr_GetHandledException(): 974. and *note
     PyErr_SetHandledException(): 975.  These are alternatives to *note
     PyErr_SetExcInfo(): 976. and *note PyErr_GetExcInfo(): 977. which
     work with the legacy 3-tuple representation of exceptions.
     (Contributed by Irit Katriel in bpo-46343(8).)

   * Added the *note PyConfig.safe_path: 978. member.  (Contributed by
     Victor Stinner in gh-57684(9).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42035

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42035

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43760

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43931

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45459

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46613

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46906

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46343

   (9) https://github.com/python/cpython/issues/57684


File: python.info,  Node: Porting to Python 3 11<2>,  Next: Deprecated<3>,  Prev: New Features<4>,  Up: C API Changes<2>

1.4.16.2 Porting to Python 3.11
...............................

   * Some macros have been converted to static inline functions to avoid
     macro pitfalls(1).  The change should be mostly transparent to
     users, as the replacement functions will cast their arguments to
     the expected types to avoid compiler warnings due to static type
     checks.  However, when the limited C API is set to >=3.11, these
     casts are not done, and callers will need to cast arguments to
     their expected types.  See PEP 670(2) for more details.
     (Contributed by Victor Stinner and Erlend E. Aasland in
     gh-89653(3).)

   * *note PyErr_SetExcInfo(): 976. no longer uses the ‘type’ and
     ‘traceback’ arguments, the interpreter now derives those values
     from the exception instance (the ‘value’ argument).  The function
     still steals references of all three arguments.  (Contributed by
     Irit Katriel in bpo-45711(4).)

   * *note PyErr_GetExcInfo(): 977. now derives the ‘type’ and
     ‘traceback’ fields of the result from the exception instance (the
     ‘value’ field).  (Contributed by Irit Katriel in bpo-45711(5).)

   * *note _frozen: 97a. has a new ‘is_package’ field to indicate
     whether or not the frozen module is a package.  Previously, a
     negative value in the ‘size’ field was the indicator.  Now only
     non-negative values be used for ‘size’.  (Contributed by Kumar
     Aditya in bpo-46608(6).)

   * *note _PyFrameEvalFunction(): 97b. now takes ‘_PyInterpreterFrame*’
     as its second parameter, instead of ‘PyFrameObject*’.  See PEP
     523(7) for more details of how to use this function pointer type.

   * ‘PyCode_New()’ and ‘PyCode_NewWithPosOnlyArgs()’ now take an
     additional ‘exception_table’ argument.  Using these functions
     should be avoided, if at all possible.  To get a custom code
     object: create a code object using the compiler, then get a
     modified version with the ‘replace’ method.

   * *note PyCodeObject: 97c. no longer has the ‘co_code’,
     ‘co_varnames’, ‘co_cellvars’ and ‘co_freevars’ fields.  Instead,
     use *note PyCode_GetCode(): 97d, *note PyCode_GetVarnames(): 97e,
     *note PyCode_GetCellvars(): 97f. and *note PyCode_GetFreevars():
     980. respectively to access them via the C API. (Contributed by
     Brandt Bucher in bpo-46841(8) and Ken Jin in gh-92154(9) and
     gh-94936(10).)

   * The old trashcan macros
     (‘Py_TRASHCAN_SAFE_BEGIN’/‘Py_TRASHCAN_SAFE_END’) are now
     deprecated.  They should be replaced by the new macros
     ‘Py_TRASHCAN_BEGIN’ and ‘Py_TRASHCAN_END’.

     A tp_dealloc function that has the old macros, such as:

          static void
          mytype_dealloc(mytype *p)
          {
              PyObject_GC_UnTrack(p);
              Py_TRASHCAN_SAFE_BEGIN(p);
              ...
              Py_TRASHCAN_SAFE_END
          }

     should migrate to the new macros as follows:

          static void
          mytype_dealloc(mytype *p)
          {
              PyObject_GC_UnTrack(p);
              Py_TRASHCAN_BEGIN(p, mytype_dealloc)
              ...
              Py_TRASHCAN_END
          }

     Note that ‘Py_TRASHCAN_BEGIN’ has a second argument which should be
     the deallocation function it is in.

     To support older Python versions in the same codebase, you can
     define the following macros and use them throughout the code
     (credit: these were copied from the ‘mypy’ codebase):

          #if PY_VERSION_HEX >= 0x03080000
          #  define CPy_TRASHCAN_BEGIN(op, dealloc) Py_TRASHCAN_BEGIN(op, dealloc)
          #  define CPy_TRASHCAN_END(op) Py_TRASHCAN_END
          #else
          #  define CPy_TRASHCAN_BEGIN(op, dealloc) Py_TRASHCAN_SAFE_BEGIN(op)
          #  define CPy_TRASHCAN_END(op) Py_TRASHCAN_SAFE_END(op)
          #endif

   * The *note PyType_Ready(): 981. function now raises an error if a
     type is defined with the *note Py_TPFLAGS_HAVE_GC: 982. flag set
     but has no traverse function (*note PyTypeObject.tp_traverse:
     983.).  (Contributed by Victor Stinner in bpo-44263(11).)

   * Heap types with the *note Py_TPFLAGS_IMMUTABLETYPE: 3cf. flag can
     now inherit the PEP 590(12) vectorcall protocol.  Previously, this
     was only possible for *note static types: 984.  (Contributed by
     Erlend E. Aasland in bpo-43908(13))

   * Since *note Py_TYPE(): 3c9. is changed to a inline static function,
     ‘Py_TYPE(obj) = new_type’ must be replaced with ‘Py_SET_TYPE(obj,
     new_type)’: see the *note Py_SET_TYPE(): 985. function (available
     since Python 3.9).  For backward compatibility, this macro can be
     used:

          #if PY_VERSION_HEX < 0x030900A4 && !defined(Py_SET_TYPE)
          static inline void _Py_SET_TYPE(PyObject *ob, PyTypeObject *type)
          { ob->ob_type = type; }
          #define Py_SET_TYPE(ob, type) _Py_SET_TYPE((PyObject*)(ob), type)
          #endif

     (Contributed by Victor Stinner in bpo-39573(14).)

   * Since *note Py_SIZE(): 986. is changed to a inline static function,
     ‘Py_SIZE(obj) = new_size’ must be replaced with ‘Py_SET_SIZE(obj,
     new_size)’: see the *note Py_SET_SIZE(): 987. function (available
     since Python 3.9).  For backward compatibility, this macro can be
     used:

          #if PY_VERSION_HEX < 0x030900A4 && !defined(Py_SET_SIZE)
          static inline void _Py_SET_SIZE(PyVarObject *ob, Py_ssize_t size)
          { ob->ob_size = size; }
          #define Py_SET_SIZE(ob, size) _Py_SET_SIZE((PyVarObject*)(ob), size)
          #endif

     (Contributed by Victor Stinner in bpo-39573(15).)

   * ‘<Python.h>’ no longer includes the header files ‘<stdlib.h>’,
     ‘<stdio.h>’, ‘<errno.h>’ and ‘<string.h>’ when the ‘Py_LIMITED_API’
     macro is set to ‘0x030b0000’ (Python 3.11) or higher.  C extensions
     should explicitly include the header files after ‘#include
     <Python.h>’.  (Contributed by Victor Stinner in bpo-45434(16).)

   * The non-limited API files ‘cellobject.h’, ‘classobject.h’,
     ‘code.h’, ‘context.h’, ‘funcobject.h’, ‘genobject.h’ and
     ‘longintrepr.h’ have been moved to the ‘Include/cpython’ directory.
     Moreover, the ‘eval.h’ header file was removed.  These files must
     not be included directly, as they are already included in
     ‘Python.h’: *note Include Files: 988.  If they have been included
     directly, consider including ‘Python.h’ instead.  (Contributed by
     Victor Stinner in bpo-35134(17).)

   * The ‘PyUnicode_CHECK_INTERNED()’ macro has been excluded from the
     limited C API. It was never usable there, because it used internal
     structures which are not available in the limited C API.
     (Contributed by Victor Stinner in bpo-46007(18).)

   * The following frame functions and type are now directly available
     with ‘#include <Python.h>’, it’s no longer needed to add ‘#include
     <frameobject.h>’:

        * *note PyFrame_Check(): 989.

        * *note PyFrame_GetBack(): 98a.

        * *note PyFrame_GetBuiltins(): 970.

        * *note PyFrame_GetGenerator(): 971.

        * *note PyFrame_GetGlobals(): 972.

        * *note PyFrame_GetLasti(): 973.

        * *note PyFrame_GetLocals(): 661.

        * *note PyFrame_Type: 98b.

     (Contributed by Victor Stinner in gh-93937(19).)

   * The *note PyFrameObject: 98d. structure members have been removed
     from the public C API.

     While the documentation notes that the *note PyFrameObject: 98d.
     fields are subject to change at any time, they have been stable for
     a long time and were used in several popular extensions.

     In Python 3.11, the frame struct was reorganized to allow
     performance optimizations.  Some fields were removed entirely, as
     they were details of the old implementation.

     *note PyFrameObject: 98d. fields:

        * ‘f_back’: use *note PyFrame_GetBack(): 98a.

        * ‘f_blockstack’: removed.

        * ‘f_builtins’: use *note PyFrame_GetBuiltins(): 970.

        * ‘f_code’: use *note PyFrame_GetCode(): 98e.

        * ‘f_gen’: use *note PyFrame_GetGenerator(): 971.

        * ‘f_globals’: use *note PyFrame_GetGlobals(): 972.

        * ‘f_iblock’: removed.

        * ‘f_lasti’: use *note PyFrame_GetLasti(): 973.  Code using
          ‘f_lasti’ with ‘PyCode_Addr2Line()’ should use *note
          PyFrame_GetLineNumber(): 98f. instead; it may be faster.

        * ‘f_lineno’: use *note PyFrame_GetLineNumber(): 98f.

        * ‘f_locals’: use *note PyFrame_GetLocals(): 661.

        * ‘f_stackdepth’: removed.

        * ‘f_state’: no public API (renamed to ‘f_frame.f_state’).

        * ‘f_trace’: no public API.

        * ‘f_trace_lines’: use ‘PyObject_GetAttrString((PyObject*)frame,
          "f_trace_lines")’.

        * ‘f_trace_opcodes’: use
          ‘PyObject_GetAttrString((PyObject*)frame, "f_trace_opcodes")’.

        * ‘f_localsplus’: no public API (renamed to
          ‘f_frame.localsplus’).

        * ‘f_valuestack’: removed.

     The Python frame object is now created lazily.  A side effect is
     that the *note f_back: 990. member must not be accessed directly,
     since its value is now also computed lazily.  The *note
     PyFrame_GetBack(): 98a. function must be called instead.

     Debuggers that accessed the *note f_locals: 4a6. directly 'must'
     call *note PyFrame_GetLocals(): 661. instead.  They no longer need
     to call ‘PyFrame_FastToLocalsWithError()’ or
     ‘PyFrame_LocalsToFast()’, in fact they should not call those
     functions.  The necessary updating of the frame is now managed by
     the virtual machine.

     Code defining ‘PyFrame_GetCode()’ on Python 3.8 and older:

          #if PY_VERSION_HEX < 0x030900B1
          static inline PyCodeObject* PyFrame_GetCode(PyFrameObject *frame)
          {
              Py_INCREF(frame->f_code);
              return frame->f_code;
          }
          #endif

     Code defining ‘PyFrame_GetBack()’ on Python 3.8 and older:

          #if PY_VERSION_HEX < 0x030900B1
          static inline PyFrameObject* PyFrame_GetBack(PyFrameObject *frame)
          {
              Py_XINCREF(frame->f_back);
              return frame->f_back;
          }
          #endif

     Or use the pythoncapi_compat project(20) to get these two functions
     on older Python versions.

   * Changes of the *note PyThreadState: 991. structure members:

        * ‘frame’: removed, use *note PyThreadState_GetFrame(): 992.
          (function added to Python 3.9 by bpo-40429(21)).  Warning: the
          function returns a *note strong reference: 5e2, need to call
          *note Py_XDECREF(): 993.

        * ‘tracing’: changed, use *note PyThreadState_EnterTracing():
          95b. and *note PyThreadState_LeaveTracing(): 95c. (functions
          added to Python 3.11 by bpo-43760(22)).

        * ‘recursion_depth’: removed, use ‘(tstate->recursion_limit -
          tstate->recursion_remaining)’ instead.

        * ‘stackcheck_counter’: removed.

     Code defining ‘PyThreadState_GetFrame()’ on Python 3.8 and older:

          #if PY_VERSION_HEX < 0x030900B1
          static inline PyFrameObject* PyThreadState_GetFrame(PyThreadState *tstate)
          {
              Py_XINCREF(tstate->frame);
              return tstate->frame;
          }
          #endif

     Code defining ‘PyThreadState_EnterTracing()’ and
     ‘PyThreadState_LeaveTracing()’ on Python 3.10 and older:

          #if PY_VERSION_HEX < 0x030B00A2
          static inline void PyThreadState_EnterTracing(PyThreadState *tstate)
          {
              tstate->tracing++;
          #if PY_VERSION_HEX >= 0x030A00A1
              tstate->cframe->use_tracing = 0;
          #else
              tstate->use_tracing = 0;
          #endif
          }

          static inline void PyThreadState_LeaveTracing(PyThreadState *tstate)
          {
              int use_tracing = (tstate->c_tracefunc != NULL || tstate->c_profilefunc != NULL);
              tstate->tracing--;
          #if PY_VERSION_HEX >= 0x030A00A1
              tstate->cframe->use_tracing = use_tracing;
          #else
              tstate->use_tracing = use_tracing;
          #endif
          }
          #endif

     Or use the pythoncapi-compat project(23) to get these functions on
     old Python functions.

   * Distributors are encouraged to build Python with the optimized
     Blake2 library libb2(24).

   * The *note PyConfig.module_search_paths_set: 806. field must now be
     set to 1 for initialization to use *note
     PyConfig.module_search_paths: 643. to initialize *note sys.path:
     3e4.  Otherwise, initialization will recalculate the path and
     replace any values added to ‘module_search_paths’.

   * *note PyConfig_Read(): 994. no longer calculates the initial search
     path, and will not fill any values into *note
     PyConfig.module_search_paths: 643.  To calculate default paths and
     then modify them, finish initialization and use *note
     PySys_GetObject(): 62a. to retrieve *note sys.path: 3e4. as a
     Python list object and modify it directly.

   ---------- Footnotes ----------

   (1) https://gcc.gnu.org/onlinedocs/cpp/Macro-Pitfalls.html

   (2) https://peps.python.org/pep-0670/

   (3) https://github.com/python/cpython/issues/89653

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45711

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45711

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46608

   (7) https://peps.python.org/pep-0523/

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (9) https://github.com/python/cpython/issues/92154

   (10) https://github.com/python/cpython/issues/94936

   (11) https://bugs.python.org/issue?@action=redirect&bpo=44263

   (12) https://peps.python.org/pep-0590/

   (13) https://bugs.python.org/issue?@action=redirect&bpo=43908

   (14) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (15) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (16) https://bugs.python.org/issue?@action=redirect&bpo=45434

   (17) https://bugs.python.org/issue?@action=redirect&bpo=35134

   (18) https://bugs.python.org/issue?@action=redirect&bpo=46007

   (19) https://github.com/python/cpython/issues/93937

   (20) https://github.com/python/pythoncapi-compat

   (21) https://bugs.python.org/issue?@action=redirect&bpo=40429

   (22) https://bugs.python.org/issue?@action=redirect&bpo=43760

   (23) https://github.com/python/pythoncapi-compat

   (24) https://www.blake2.net/


File: python.info,  Node: Deprecated<3>,  Next: Pending Removal in Python 3 12<2>,  Prev: Porting to Python 3 11<2>,  Up: C API Changes<2>

1.4.16.3 Deprecated
...................

   * Deprecate the following functions to configure the Python
     initialization:

        * ‘PySys_AddWarnOptionUnicode()’

        * ‘PySys_AddWarnOption()’

        * ‘PySys_AddXOption()’

        * ‘PySys_HasWarnOptions()’

        * ‘PySys_SetArgvEx()’

        * ‘PySys_SetArgv()’

        * ‘PySys_SetPath()’

        * ‘Py_SetPath()’

        * ‘Py_SetProgramName()’

        * ‘Py_SetPythonHome()’

        * ‘Py_SetStandardStreamEncoding()’

        * ‘_Py_SetProgramFullPath()’

     Use the new *note PyConfig: 3f7. API of the *note Python
     Initialization Configuration: 646. instead ( PEP 587(1)).
     (Contributed by Victor Stinner in gh-88279(2).)

   * Deprecate the ‘ob_shash’ member of the *note PyBytesObject: 996.
     Use *note PyObject_Hash(): 436. instead.  (Contributed by Inada
     Naoki in bpo-46864(3).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0587/

   (2) https://github.com/python/cpython/issues/88279

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46864


File: python.info,  Node: Pending Removal in Python 3 12<2>,  Next: Removed<3>,  Prev: Deprecated<3>,  Up: C API Changes<2>

1.4.16.4 Pending Removal in Python 3.12
.......................................

The following C APIs have been deprecated in earlier Python releases,
and will be removed in Python 3.12.

   * ‘PyUnicode_AS_DATA()’

   * ‘PyUnicode_AS_UNICODE()’

   * ‘PyUnicode_AsUnicodeAndSize()’

   * ‘PyUnicode_AsUnicode()’

   * ‘PyUnicode_FromUnicode()’

   * ‘PyUnicode_GET_DATA_SIZE()’

   * ‘PyUnicode_GET_SIZE()’

   * ‘PyUnicode_GetSize()’

   * ‘PyUnicode_IS_COMPACT()’

   * ‘PyUnicode_IS_READY()’

   * *note PyUnicode_READY(): 434.

   * ‘PyUnicode_WSTR_LENGTH()’

   * ‘_PyUnicode_AsUnicode()’

   * ‘PyUnicode_WCHAR_KIND’

   * *note PyUnicodeObject: 998.

   * ‘PyUnicode_InternImmortal()’


File: python.info,  Node: Removed<3>,  Prev: Pending Removal in Python 3 12<2>,  Up: C API Changes<2>

1.4.16.5 Removed
................

   * ‘PyFrame_BlockSetup()’ and ‘PyFrame_BlockPop()’ have been removed.
     (Contributed by Mark Shannon in bpo-40222(1).)

   * Remove the following math macros using the ‘errno’ variable:

        * ‘Py_ADJUST_ERANGE1()’

        * ‘Py_ADJUST_ERANGE2()’

        * ‘Py_OVERFLOWED()’

        * ‘Py_SET_ERANGE_IF_OVERFLOW()’

        * ‘Py_SET_ERRNO_ON_MATH_ERROR()’

     (Contributed by Victor Stinner in bpo-45412(2).)

   * Remove ‘Py_UNICODE_COPY()’ and ‘Py_UNICODE_FILL()’ macros,
     deprecated since Python 3.3.  Use ‘PyUnicode_CopyCharacters()’ or
     ‘memcpy()’ (‘wchar_t*’ string), and ‘PyUnicode_Fill()’ functions
     instead.  (Contributed by Victor Stinner in bpo-41123(3).)

   * Remove the ‘pystrhex.h’ header file.  It only contains private
     functions.  C extensions should only include the main ‘<Python.h>’
     header file.  (Contributed by Victor Stinner in bpo-45434(4).)

   * Remove the ‘Py_FORCE_DOUBLE()’ macro.  It was used by the
     ‘Py_IS_INFINITY()’ macro.  (Contributed by Victor Stinner in
     bpo-45440(5).)

   * The following items are no longer available when *note
     Py_LIMITED_API: 660. is defined:

        * *note PyMarshal_WriteLongToFile(): 99a.

        * *note PyMarshal_WriteObjectToFile(): 99b.

        * *note PyMarshal_ReadObjectFromString(): 99c.

        * *note PyMarshal_WriteObjectToString(): 99d.

        * the ‘Py_MARSHAL_VERSION’ macro

     These are not part of the *note limited API: 99e.

     (Contributed by Victor Stinner in bpo-45474(6).)

   * Exclude *note PyWeakref_GET_OBJECT(): 3de. from the limited C API.
     It never worked since the ‘PyWeakReference’ structure is opaque in
     the limited C API. (Contributed by Victor Stinner in bpo-35134(7).)

   * Remove the ‘PyHeapType_GET_MEMBERS()’ macro.  It was exposed in the
     public C API by mistake, it must only be used by Python internally.
     Use the ‘PyTypeObject.tp_members’ member instead.  (Contributed by
     Victor Stinner in bpo-40170(8).)

   * Remove the ‘HAVE_PY_SET_53BIT_PRECISION’ macro (moved to the
     internal C API). (Contributed by Victor Stinner in bpo-45412(9).)

   * Remove the *note Py_UNICODE: 3e0. encoder APIs, as they have been
     deprecated since Python 3.3, are little used and are inefficient
     relative to the recommended alternatives.

     The removed functions are:

        * ‘PyUnicode_Encode()’

        * ‘PyUnicode_EncodeASCII()’

        * ‘PyUnicode_EncodeLatin1()’

        * ‘PyUnicode_EncodeUTF7()’

        * ‘PyUnicode_EncodeUTF8()’

        * ‘PyUnicode_EncodeUTF16()’

        * ‘PyUnicode_EncodeUTF32()’

        * ‘PyUnicode_EncodeUnicodeEscape()’

        * ‘PyUnicode_EncodeRawUnicodeEscape()’

        * ‘PyUnicode_EncodeCharmap()’

        * ‘PyUnicode_TranslateCharmap()’

        * ‘PyUnicode_EncodeDecimal()’

        * ‘PyUnicode_TransformDecimalToASCII()’

     See PEP 624(10) for details and migration guidance(11).
     (Contributed by Inada Naoki in bpo-44029(12).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40222

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45412

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41123

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45434

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45440

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45474

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35134

   (8) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45412

   (10) https://peps.python.org/pep-0624/

   (11) https://peps.python.org/pep-0624/#alternative-apis

   (12) https://bugs.python.org/issue?@action=redirect&bpo=44029


File: python.info,  Node: Notable changes in 3 11 4,  Next: Notable changes in 3 11 5,  Prev: C API Changes<2>,  Up: What’s New In Python 3 11

1.4.17 Notable changes in 3.11.4
--------------------------------

* Menu:

* tarfile: tarfile<2>.


File: python.info,  Node: tarfile<2>,  Up: Notable changes in 3 11 4

1.4.17.1 tarfile
................

   * The extraction methods in *note tarfile: e4, and *note
     shutil.unpack_archive(): 697, have a new a 'filter' argument that
     allows limiting tar features than may be surprising or dangerous,
     such as creating files outside the destination directory.  See
     *note Extraction filters: 698. for details.  In Python 3.12, use
     without the 'filter' argument will show a *note DeprecationWarning:
     1a3.  In Python 3.14, the default will switch to ‘'data'’.
     (Contributed by Petr Viktorin in PEP 706(1).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0706/


File: python.info,  Node: Notable changes in 3 11 5,  Prev: Notable changes in 3 11 4,  Up: What’s New In Python 3 11

1.4.18 Notable changes in 3.11.5
--------------------------------

* Menu:

* OpenSSL::


File: python.info,  Node: OpenSSL,  Up: Notable changes in 3 11 5

1.4.18.1 OpenSSL
................

   * Windows builds and macOS installers from python.org now use OpenSSL
     3.0.


File: python.info,  Node: What’s New In Python 3 10,  Next: What’s New In Python 3 9,  Prev: What’s New In Python 3 11,  Up: Novità in Python

1.5 What’s New In Python 3.10
=============================


Editor: Pablo Galindo Salgado

This article explains the new features in Python 3.10, compared to 3.9.
Python 3.10 was released on October 4, 2021.  For full details, see the
*note changelog: 142.

* Menu:

* Summary – Release highlights: Summary – Release highlights<3>.
* New Features: New Features<5>.
* New Features Related to Type Hints: New Features Related to Type Hints<2>.
* Other Language Changes: Other Language Changes<3>.
* New Modules: New Modules<3>.
* Improved Modules: Improved Modules<3>.
* Optimizations: Optimizations<4>.
* Deprecated: Deprecated<4>.
* Removed: Removed<4>.
* Porting to Python 3.10: Porting to Python 3 10.
* CPython bytecode changes: CPython bytecode changes<3>.
* Build Changes: Build Changes<3>.
* C API Changes: C API Changes<3>.
* Notable security feature in 3.10.7: Notable security feature in 3 10 7.
* Notable security feature in 3.10.8: Notable security feature in 3 10 8.
* Notable changes in 3.10.12: Notable changes in 3 10 12.


File: python.info,  Node: Summary – Release highlights<3>,  Next: New Features<5>,  Up: What’s New In Python 3 10

1.5.1 Summary – Release highlights
----------------------------------

New syntax features:

   * PEP 634(1), Structural Pattern Matching: Specification

   * PEP 635(2), Structural Pattern Matching: Motivation and Rationale

   * PEP 636(3), Structural Pattern Matching: Tutorial

   * bpo-12782(4), Parenthesized context managers are now officially
     allowed.

New features in the standard library:

   * PEP 618(5), Add Optional Length-Checking To zip.

Interpreter improvements:

   * PEP 626(6), Precise line numbers for debugging and other tools.

New typing features:

   * PEP 604(7), Allow writing union types as X | Y

   * PEP 612(8), Parameter Specification Variables

   * PEP 613(9), Explicit Type Aliases

   * PEP 647(10), User-Defined Type Guards

Important deprecations, removals or restrictions:

   * PEP 644(11), Require OpenSSL 1.1.1 or newer

   * PEP 632(12), Deprecate distutils module.

   * PEP 623(13), Deprecate and prepare for the removal of the wstr
     member in PyUnicodeObject.

   * PEP 624(14), Remove Py_UNICODE encoder APIs

   * PEP 597(15), Add optional EncodingWarning

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0634/

   (2) https://peps.python.org/pep-0635/

   (3) https://peps.python.org/pep-0636/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=12782

   (5) https://peps.python.org/pep-0618/

   (6) https://peps.python.org/pep-0626/

   (7) https://peps.python.org/pep-0604/

   (8) https://peps.python.org/pep-0612/

   (9) https://peps.python.org/pep-0613/

   (10) https://peps.python.org/pep-0647/

   (11) https://peps.python.org/pep-0644/

   (12) https://peps.python.org/pep-0632/

   (13) https://peps.python.org/pep-0623/

   (14) https://peps.python.org/pep-0624/

   (15) https://peps.python.org/pep-0597/


File: python.info,  Node: New Features<5>,  Next: New Features Related to Type Hints<2>,  Prev: Summary – Release highlights<3>,  Up: What’s New In Python 3 10

1.5.2 New Features
------------------

* Menu:

* Parenthesized context managers::
* Better error messages::
* PEP 626; Precise line numbers for debugging and other tools: PEP 626 Precise line numbers for debugging and other tools.
* PEP 634; Structural Pattern Matching: PEP 634 Structural Pattern Matching.
* Optional EncodingWarning and encoding="locale" option::


File: python.info,  Node: Parenthesized context managers,  Next: Better error messages,  Up: New Features<5>

1.5.2.1 Parenthesized context managers
......................................

Using enclosing parentheses for continuation across multiple lines in
context managers is now supported.  This allows formatting a long
collection of context managers in multiple lines in a similar way as it
was previously possible with import statements.  For instance, all these
examples are now valid:

     with (CtxManager() as example):
         ...

     with (
         CtxManager1(),
         CtxManager2()
     ):
         ...

     with (CtxManager1() as example,
           CtxManager2()):
         ...

     with (CtxManager1(),
           CtxManager2() as example):
         ...

     with (
         CtxManager1() as example1,
         CtxManager2() as example2
     ):
         ...

it is also possible to use a trailing comma at the end of the enclosed
group:

     with (
         CtxManager1() as example1,
         CtxManager2() as example2,
         CtxManager3() as example3,
     ):
         ...

This new syntax uses the non LL(1) capacities of the new parser.  Check
PEP 617(1) for more details.

(Contributed by Guido van Rossum, Pablo Galindo and Lysandros Nikolaou
in bpo-12782(2) and bpo-40334(3).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0617/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=12782

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40334


File: python.info,  Node: Better error messages,  Next: PEP 626 Precise line numbers for debugging and other tools,  Prev: Parenthesized context managers,  Up: New Features<5>

1.5.2.2 Better error messages
.............................

* Menu:

* SyntaxErrors::
* IndentationErrors::
* AttributeErrors::
* NameErrors::


File: python.info,  Node: SyntaxErrors,  Next: IndentationErrors,  Up: Better error messages

1.5.2.3 SyntaxErrors
....................

When parsing code that contains unclosed parentheses or brackets the
interpreter now includes the location of the unclosed bracket of
parentheses instead of displaying 'SyntaxError: unexpected EOF while
parsing' or pointing to some incorrect location.  For instance, consider
the following code (notice the unclosed “{“):

     expected = {9: 1, 18: 2, 19: 2, 27: 3, 28: 3, 29: 3, 36: 4, 37: 4,
                 38: 4, 39: 4, 45: 5, 46: 5, 47: 5, 48: 5, 49: 5, 54: 6,
     some_other_code = foo()

Previous versions of the interpreter reported confusing places as the
location of the syntax error:

     File "example.py", line 3
         some_other_code = foo()
                         ^
     SyntaxError: invalid syntax

but in Python 3.10 a more informative error is emitted:

     File "example.py", line 1
         expected = {9: 1, 18: 2, 19: 2, 27: 3, 28: 3, 29: 3, 36: 4, 37: 4,
                    ^
     SyntaxError: '{' was never closed

In a similar way, errors involving unclosed string literals (single and
triple quoted) now point to the start of the string instead of reporting
EOF/EOL.

These improvements are inspired by previous work in the PyPy
interpreter.

(Contributed by Pablo Galindo in bpo-42864(1) and Batuhan Taskaya in
bpo-40176(2).)

*note SyntaxError: 18e. exceptions raised by the interpreter will now
highlight the full error range of the expression that constitutes the
syntax error itself, instead of just where the problem is detected.  In
this way, instead of displaying (before Python 3.10):

     >>> foo(x, z for z in range(10), t, w)
       File "<stdin>", line 1
         foo(x, z for z in range(10), t, w)
                ^
     SyntaxError: Generator expression must be parenthesized

now Python 3.10 will display the exception as:

     >>> foo(x, z for z in range(10), t, w)
       File "<stdin>", line 1
         foo(x, z for z in range(10), t, w)
                ^^^^^^^^^^^^^^^^^^^^
     SyntaxError: Generator expression must be parenthesized

This improvement was contributed by Pablo Galindo in bpo-43914(3).

A considerable amount of new specialized messages for *note SyntaxError:
18e. exceptions have been incorporated.  Some of the most notable ones
are as follows:

   * Missing ‘:’ before blocks:

          >>> if rocket.position > event_horizon
            File "<stdin>", line 1
              if rocket.position > event_horizon
                                                ^
          SyntaxError: expected ':'

     (Contributed by Pablo Galindo in bpo-42997(4).)

   * Unparenthesised tuples in comprehensions targets:

          >>> {x,y for x,y in zip('abcd', '1234')}
            File "<stdin>", line 1
              {x,y for x,y in zip('abcd', '1234')}
               ^
          SyntaxError: did you forget parentheses around the comprehension target?

     (Contributed by Pablo Galindo in bpo-43017(5).)

   * Missing commas in collection literals and between expressions:

          >>> items = {
          ... x: 1,
          ... y: 2
          ... z: 3,
            File "<stdin>", line 3
              y: 2
                 ^
          SyntaxError: invalid syntax. Perhaps you forgot a comma?

     (Contributed by Pablo Galindo in bpo-43822(6).)

   * Multiple Exception types without parentheses:

          >>> try:
          ...     build_dyson_sphere()
          ... except NotEnoughScienceError, NotEnoughResourcesError:
            File "<stdin>", line 3
              except NotEnoughScienceError, NotEnoughResourcesError:
                     ^
          SyntaxError: multiple exception types must be parenthesized

     (Contributed by Pablo Galindo in bpo-43149(7).)

   * Missing ‘:’ and values in dictionary literals:

          >>> values = {
          ... x: 1,
          ... y: 2,
          ... z:
          ... }
            File "<stdin>", line 4
              z:
               ^
          SyntaxError: expression expected after dictionary key and ':'

          >>> values = {x:1, y:2, z w:3}
            File "<stdin>", line 1
              values = {x:1, y:2, z w:3}
                                  ^
          SyntaxError: ':' expected after dictionary key

     (Contributed by Pablo Galindo in bpo-43823(8).)

   * ‘try’ blocks without ‘except’ or ‘finally’ blocks:

          >>> try:
          ...     x = 2
          ... something = 3
            File "<stdin>", line 3
              something  = 3
              ^^^^^^^^^
          SyntaxError: expected 'except' or 'finally' block

     (Contributed by Pablo Galindo in bpo-44305(9).)

   * Usage of ‘=’ instead of ‘==’ in comparisons:

          >>> if rocket.position = event_horizon:
            File "<stdin>", line 1
              if rocket.position = event_horizon:
                                 ^
          SyntaxError: cannot assign to attribute here. Maybe you meant '==' instead of '='?

     (Contributed by Pablo Galindo in bpo-43797(10).)

   * Usage of ‘*’ in f-strings:

          >>> f"Black holes {*all_black_holes} and revelations"
            File "<stdin>", line 1
              (*all_black_holes)
               ^
          SyntaxError: f-string: cannot use starred expression here

     (Contributed by Pablo Galindo in bpo-41064(11).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42864

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40176

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43914

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42997

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43017

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43822

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43149

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43823

   (9) https://bugs.python.org/issue?@action=redirect&bpo=44305

   (10) https://bugs.python.org/issue?@action=redirect&bpo=43797

   (11) https://bugs.python.org/issue?@action=redirect&bpo=41064


File: python.info,  Node: IndentationErrors,  Next: AttributeErrors,  Prev: SyntaxErrors,  Up: Better error messages

1.5.2.4 IndentationErrors
.........................

Many *note IndentationError: 9ad. exceptions now have more context
regarding what kind of block was expecting an indentation, including the
location of the statement:

     >>> def foo():
     ...    if lel:
     ...    x = 2
       File "<stdin>", line 3
         x = 2
         ^
     IndentationError: expected an indented block after 'if' statement in line 2


File: python.info,  Node: AttributeErrors,  Next: NameErrors,  Prev: IndentationErrors,  Up: Better error messages

1.5.2.5 AttributeErrors
.......................

When printing *note AttributeError: 5f0, ‘PyErr_Display()’ will offer
suggestions of similar attribute names in the object that the exception
was raised from:

     >>> collections.namedtoplo
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     AttributeError: module 'collections' has no attribute 'namedtoplo'. Did you mean: namedtuple?

(Contributed by Pablo Galindo in bpo-38530(1).)

     Avvertimento: Notice this won’t work if ‘PyErr_Display()’ is not
     called to display the error which can happen if some other custom
     error display function is used.  This is a common scenario in some
     REPLs like IPython.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38530


File: python.info,  Node: NameErrors,  Prev: AttributeErrors,  Up: Better error messages

1.5.2.6 NameErrors
..................

When printing *note NameError: 452. raised by the interpreter,
‘PyErr_Display()’ will offer suggestions of similar variable names in
the function that the exception was raised from:

     >>> schwarzschild_black_hole = None
     >>> schwarschild_black_hole
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     NameError: name 'schwarschild_black_hole' is not defined. Did you mean: schwarzschild_black_hole?

(Contributed by Pablo Galindo in bpo-38530(1).)

     Avvertimento: Notice this won’t work if ‘PyErr_Display()’ is not
     called to display the error, which can happen if some other custom
     error display function is used.  This is a common scenario in some
     REPLs like IPython.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38530


File: python.info,  Node: PEP 626 Precise line numbers for debugging and other tools,  Next: PEP 634 Structural Pattern Matching,  Prev: Better error messages,  Up: New Features<5>

1.5.2.7 PEP 626: Precise line numbers for debugging and other tools
...................................................................

PEP 626 brings more precise and reliable line numbers for debugging,
profiling and coverage tools.  Tracing events, with the correct line
number, are generated for all lines of code executed and only for lines
of code that are executed.

The *note f_lineno: 9b1. attribute of frame objects will always contain
the expected line number.

The *note co_lnotab: 330. attribute of *note code objects: 4e7. is
deprecated and will be removed in 3.12.  Code that needs to convert from
offset to line number should use the new *note co_lines(): 350. method
instead.


File: python.info,  Node: PEP 634 Structural Pattern Matching,  Next: Optional EncodingWarning and encoding="locale" option,  Prev: PEP 626 Precise line numbers for debugging and other tools,  Up: New Features<5>

1.5.2.8 PEP 634: Structural Pattern Matching
............................................

Structural pattern matching has been added in the form of a 'match
statement' and 'case statements' of patterns with associated actions.
Patterns consist of sequences, mappings, primitive data types as well as
class instances.  Pattern matching enables programs to extract
information from complex data types, branch on the structure of data,
and apply specific actions based on different forms of data.

* Menu:

* Syntax and operations::
* Declarative approach::
* Simple pattern; match to a literal: Simple pattern match to a literal.
* Patterns with a literal and variable::
* Patterns and classes::
* Nested patterns::
* Complex patterns and the wildcard::
* Guard::
* Other Key Features::


File: python.info,  Node: Syntax and operations,  Next: Declarative approach,  Up: PEP 634 Structural Pattern Matching

1.5.2.9 Syntax and operations
.............................

The generic syntax of pattern matching is:

     match subject:
         case <pattern_1>:
             <action_1>
         case <pattern_2>:
             <action_2>
         case <pattern_3>:
             <action_3>
         case _:
             <action_wildcard>

A match statement takes an expression and compares its value to
successive patterns given as one or more case blocks.  Specifically,
pattern matching operates by:

  1. using data with type and shape (the ‘subject’)

  2. evaluating the ‘subject’ in the ‘match’ statement

  3. comparing the subject with each pattern in a ‘case’ statement from
     top to bottom until a match is confirmed.

  4. executing the action associated with the pattern of the confirmed
     match

  5. If an exact match is not confirmed, the last case, a wildcard ‘_’,
     if provided, will be used as the matching case.  If an exact match
     is not confirmed and a wildcard case does not exist, the entire
     match block is a no-op.


File: python.info,  Node: Declarative approach,  Next: Simple pattern match to a literal,  Prev: Syntax and operations,  Up: PEP 634 Structural Pattern Matching

1.5.2.10 Declarative approach
.............................

Readers may be aware of pattern matching through the simple example of
matching a subject (data object) to a literal (pattern) with the switch
statement found in C, Java or JavaScript (and many other languages).
Often the switch statement is used for comparison of an
object/expression with case statements containing literals.

More powerful examples of pattern matching can be found in languages
such as Scala and Elixir.  With structural pattern matching, the
approach is «declarative» and explicitly states the conditions (the
patterns) for data to match.

While an «imperative» series of instructions using nested «if»
statements could be used to accomplish something similar to structural
pattern matching, it is less clear than the «declarative» approach.
Instead the «declarative» approach states the conditions to meet for a
match and is more readable through its explicit patterns.  While
structural pattern matching can be used in its simplest form comparing a
variable to a literal in a case statement, its true value for Python
lies in its handling of the subject’s type and shape.


File: python.info,  Node: Simple pattern match to a literal,  Next: Patterns with a literal and variable,  Prev: Declarative approach,  Up: PEP 634 Structural Pattern Matching

1.5.2.11 Simple pattern: match to a literal
...........................................

Let’s look at this example as pattern matching in its simplest form: a
value, the subject, being matched to several literals, the patterns.  In
the example below, ‘status’ is the subject of the match statement.  The
patterns are each of the case statements, where literals represent
request status codes.  The associated action to the case is executed
after a match:

     def http_error(status):
         match status:
             case 400:
                 return "Bad request"
             case 404:
                 return "Not found"
             case 418:
                 return "I'm a teapot"
             case _:
                 return "Something's wrong with the internet"

If the above function is passed a ‘status’ of 418, «I’m a teapot» is
returned.  If the above function is passed a ‘status’ of 500, the case
statement with ‘_’ will match as a wildcard, and «Something’s wrong with
the internet» is returned.  Note the last block: the variable name, ‘_’,
acts as a 'wildcard' and insures the subject will always match.  The use
of ‘_’ is optional.

You can combine several literals in a single pattern using ‘|’ («or»):

     case 401 | 403 | 404:
         return "Not allowed"

* Menu:

* Behavior without the wildcard::


File: python.info,  Node: Behavior without the wildcard,  Up: Simple pattern match to a literal

1.5.2.12 Behavior without the wildcard
......................................

If we modify the above example by removing the last case block, the
example becomes:

     def http_error(status):
         match status:
             case 400:
                 return "Bad request"
             case 404:
                 return "Not found"
             case 418:
                 return "I'm a teapot"

Without the use of ‘_’ in a case statement, a match may not exist.  If
no match exists, the behavior is a no-op.  For example, if ‘status’ of
500 is passed, a no-op occurs.


File: python.info,  Node: Patterns with a literal and variable,  Next: Patterns and classes,  Prev: Simple pattern match to a literal,  Up: PEP 634 Structural Pattern Matching

1.5.2.13 Patterns with a literal and variable
.............................................

Patterns can look like unpacking assignments, and a pattern may be used
to bind variables.  In this example, a data point can be unpacked to its
x-coordinate and y-coordinate:

     # point is an (x, y) tuple
     match point:
         case (0, 0):
             print("Origin")
         case (0, y):
             print(f"Y={y}")
         case (x, 0):
             print(f"X={x}")
         case (x, y):
             print(f"X={x}, Y={y}")
         case _:
             raise ValueError("Not a point")

The first pattern has two literals, ‘(0, 0)’, and may be thought of as
an extension of the literal pattern shown above.  The next two patterns
combine a literal and a variable, and the variable 'binds' a value from
the subject (‘point’).  The fourth pattern captures two values, which
makes it conceptually similar to the unpacking assignment ‘(x, y) =
point’.


File: python.info,  Node: Patterns and classes,  Next: Nested patterns,  Prev: Patterns with a literal and variable,  Up: PEP 634 Structural Pattern Matching

1.5.2.14 Patterns and classes
.............................

If you are using classes to structure your data, you can use as a
pattern the class name followed by an argument list resembling a
constructor.  This pattern has the ability to capture instance
attributes into variables:

     class Point:
         def __init__(self, x, y):
             self.x = x
             self.y = y

     def location(point):
         match point:
             case Point(x=0, y=0):
                 print("Origin is the point's location.")
             case Point(x=0, y=y):
                 print(f"Y={y} and the point is on the y-axis.")
             case Point(x=x, y=0):
                 print(f"X={x} and the point is on the x-axis.")
             case Point():
                 print("The point is located somewhere else on the plane.")
             case _:
                 print("Not a point")

* Menu:

* Patterns with positional parameters::


File: python.info,  Node: Patterns with positional parameters,  Up: Patterns and classes

1.5.2.15 Patterns with positional parameters
............................................

You can use positional parameters with some builtin classes that provide
an ordering for their attributes (e.g.  dataclasses).  You can also
define a specific position for attributes in patterns by setting the
‘__match_args__’ special attribute in your classes.  If it’s set to
(«x», «y»), the following patterns are all equivalent (and all bind the
‘y’ attribute to the ‘var’ variable):

     Point(1, var)
     Point(1, y=var)
     Point(x=1, y=var)
     Point(y=var, x=1)


File: python.info,  Node: Nested patterns,  Next: Complex patterns and the wildcard,  Prev: Patterns and classes,  Up: PEP 634 Structural Pattern Matching

1.5.2.16 Nested patterns
........................

Patterns can be arbitrarily nested.  For example, if our data is a short
list of points, it could be matched like this:

     match points:
         case []:
             print("No points in the list.")
         case [Point(0, 0)]:
             print("The origin is the only point in the list.")
         case [Point(x, y)]:
             print(f"A single point {x}, {y} is in the list.")
         case [Point(0, y1), Point(0, y2)]:
             print(f"Two points on the Y axis at {y1}, {y2} are in the list.")
         case _:
             print("Something else is found in the list.")


File: python.info,  Node: Complex patterns and the wildcard,  Next: Guard,  Prev: Nested patterns,  Up: PEP 634 Structural Pattern Matching

1.5.2.17 Complex patterns and the wildcard
..........................................

To this point, the examples have used ‘_’ alone in the last case
statement.  A wildcard can be used in more complex patterns, such as
‘('error', code, _)’.  For example:

     match test_variable:
         case ('warning', code, 40):
             print("A warning has been received.")
         case ('error', code, _):
             print(f"An error {code} occurred.")

In the above case, ‘test_variable’ will match for (“error”, code, 100)
and (“error”, code, 800).


File: python.info,  Node: Guard,  Next: Other Key Features,  Prev: Complex patterns and the wildcard,  Up: PEP 634 Structural Pattern Matching

1.5.2.18 Guard
..............

We can add an ‘if’ clause to a pattern, known as a «guard».  If the
guard is false, ‘match’ goes on to try the next case block.  Note that
value capture happens before the guard is evaluated:

     match point:
         case Point(x, y) if x == y:
             print(f"The point is located on the diagonal Y=X at {x}.")
         case Point(x, y):
             print(f"Point is not on the diagonal.")


File: python.info,  Node: Other Key Features,  Prev: Guard,  Up: PEP 634 Structural Pattern Matching

1.5.2.19 Other Key Features
...........................

Several other key features:

   - Like unpacking assignments, tuple and list patterns have exactly
     the same meaning and actually match arbitrary sequences.
     Technically, the subject must be a sequence.  Therefore, an
     important exception is that patterns don’t match iterators.  Also,
     to prevent a common mistake, sequence patterns don’t match strings.

   - Sequence patterns support wildcards: ‘[x, y, *rest]’ and ‘(x, y,
     *rest)’ work similar to wildcards in unpacking assignments.  The
     name after ‘*’ may also be ‘_’, so ‘(x, y, *_)’ matches a sequence
     of at least two items without binding the remaining items.

   - Mapping patterns: ‘{"bandwidth": b, "latency": l}’ captures the
     ‘"bandwidth"’ and ‘"latency"’ values from a dict.  Unlike sequence
     patterns, extra keys are ignored.  A wildcard ‘**rest’ is also
     supported.  (But ‘**_’ would be redundant, so is not allowed.)

   - Subpatterns may be captured using the ‘as’ keyword:

          case (Point(x1, y1), Point(x2, y2) as p2): ...

     This binds x1, y1, x2, y2 like you would expect without the ‘as’
     clause, and p2 to the entire second item of the subject.

   - Most literals are compared by equality.  However, the singletons
     ‘True’, ‘False’ and ‘None’ are compared by identity.

   - Named constants may be used in patterns.  These named constants
     must be dotted names to prevent the constant from being interpreted
     as a capture variable:

          from enum import Enum
          class Color(Enum):
              RED = 0
              GREEN = 1
              BLUE = 2

          color = Color.GREEN
          match color:
              case Color.RED:
                  print("I see red!")
              case Color.GREEN:
                  print("Grass is green")
              case Color.BLUE:
                  print("I'm feeling the blues :(")

For the full specification see PEP 634(1).  Motivation and rationale are
in PEP 635(2), and a longer tutorial is in PEP 636(3).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0634/

   (2) https://peps.python.org/pep-0635/

   (3) https://peps.python.org/pep-0636/


File: python.info,  Node: Optional EncodingWarning and encoding="locale" option,  Prev: PEP 634 Structural Pattern Matching,  Up: New Features<5>

1.5.2.20 Optional ‘EncodingWarning’ and ‘encoding="locale"’ option
..................................................................

The default encoding of *note TextIOWrapper: 9c0. and *note open(): 316.
is platform and locale dependent.  Since UTF-8 is used on most Unix
platforms, omitting ‘encoding’ option when opening UTF-8 files (e.g.
JSON, YAML, TOML, Markdown) is a very common bug.  For example:

     # BUG: "rb" mode or encoding="utf-8" should be used.
     with open("data.json") as f:
         data = json.load(f)

To find this type of bug, an optional ‘EncodingWarning’ is added.  It is
emitted when *note sys.flags.warn_default_encoding: 89d. is true and
locale-specific default encoding is used.

‘-X warn_default_encoding’ option and *note PYTHONWARNDEFAULTENCODING:
9c1. are added to enable the warning.

See *note Text Encoding: 9c2. for more information.


File: python.info,  Node: New Features Related to Type Hints<2>,  Next: Other Language Changes<3>,  Prev: New Features<5>,  Up: What’s New In Python 3 10

1.5.3 New Features Related to Type Hints
----------------------------------------

This section covers major changes affecting PEP 484(1) type hints and
the *note typing: 10a. module.

* Menu:

* PEP 604; New Type Union Operator: PEP 604 New Type Union Operator.
* PEP 612; Parameter Specification Variables: PEP 612 Parameter Specification Variables.
* PEP 613; TypeAlias: PEP 613 TypeAlias.
* PEP 647; User-Defined Type Guards: PEP 647 User-Defined Type Guards.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/


File: python.info,  Node: PEP 604 New Type Union Operator,  Next: PEP 612 Parameter Specification Variables,  Up: New Features Related to Type Hints<2>

1.5.3.1 PEP 604: New Type Union Operator
........................................

A new type union operator was introduced which enables the syntax ‘X |
Y’.  This provides a cleaner way of expressing “either type X or type Y”
instead of using *note typing.Union: 2a8, especially in type hints.

In previous versions of Python, to apply a type hint for functions
accepting arguments of multiple types, *note typing.Union: 2a8. was
used:

     def square(number: Union[int, float]) -> Union[int, float]:
         return number ** 2

Type hints can now be written in a more succinct manner:

     def square(number: int | float) -> int | float:
         return number ** 2

This new syntax is also accepted as the second argument to *note
isinstance(): 2ad. and *note issubclass(): 9c6.:

     >>> isinstance(1, int | str)
     True

See *note Tipo Unione: 9c7. and PEP 604(1) for more details.

(Contributed by Maggie Moss and Philippe Prados in bpo-41428(2), with
additions by Yurii Karabas and Serhiy Storchaka in bpo-44490(3).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0604/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41428

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44490


File: python.info,  Node: PEP 612 Parameter Specification Variables,  Next: PEP 613 TypeAlias,  Prev: PEP 604 New Type Union Operator,  Up: New Features Related to Type Hints<2>

1.5.3.2 PEP 612: Parameter Specification Variables
..................................................

Two new options to improve the information provided to static type
checkers for PEP 484(1)“s ‘Callable’ have been added to the *note
typing: 10a. module.

The first is the parameter specification variable.  They are used to
forward the parameter types of one callable to another callable – a
pattern commonly found in higher order functions and decorators.
Examples of usage can be found in *note typing.ParamSpec: 488.
Previously, there was no easy way to type annotate dependency of
parameter types in such a precise manner.

The second option is the new ‘Concatenate’ operator.  It’s used in
conjunction with parameter specification variables to type annotate a
higher order callable which adds or removes parameters of another
callable.  Examples of usage can be found in *note typing.Concatenate:
9c9.

See *note typing.Callable: 9ca, *note typing.ParamSpec: 488, *note
typing.Concatenate: 9c9, *note typing.ParamSpecArgs: 9cb, *note
typing.ParamSpecKwargs: 9cc, and PEP 612(2) for more details.

(Contributed by Ken Jin in bpo-41559(3), with minor enhancements by
Jelle Zijlstra in bpo-43783(4).  PEP written by Mark Mendoza.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0612/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41559

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43783


File: python.info,  Node: PEP 613 TypeAlias,  Next: PEP 647 User-Defined Type Guards,  Prev: PEP 612 Parameter Specification Variables,  Up: New Features Related to Type Hints<2>

1.5.3.3 PEP 613: TypeAlias
..........................

PEP 484(1) introduced the concept of type aliases, only requiring them
to be top-level unannotated assignments.  This simplicity sometimes made
it difficult for type checkers to distinguish between type aliases and
ordinary assignments, especially when forward references or invalid
types were involved.  Compare:

     StrCache = 'Cache[str]'  # a type alias
     LOG_PREFIX = 'LOG[DEBUG]'  # a module constant

Now the *note typing: 10a. module has a special value *note TypeAlias:
9ce. which lets you declare type aliases more explicitly:

     StrCache: TypeAlias = 'Cache[str]'  # a type alias
     LOG_PREFIX = 'LOG[DEBUG]'  # a module constant

See PEP 613(2) for more details.

(Contributed by Mikhail Golubev in bpo-41923(3).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0613/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41923


File: python.info,  Node: PEP 647 User-Defined Type Guards,  Prev: PEP 613 TypeAlias,  Up: New Features Related to Type Hints<2>

1.5.3.4 PEP 647: User-Defined Type Guards
.........................................

*note TypeGuard: 48d. has been added to the *note typing: 10a. module to
annotate type guard functions and improve information provided to static
type checkers during type narrowing.  For more information, please see
*note TypeGuard: 48d.“s documentation, and PEP 647(1).

(Contributed by Ken Jin and Guido van Rossum in bpo-43766(2).  PEP
written by Eric Traut.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0647/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43766


File: python.info,  Node: Other Language Changes<3>,  Next: New Modules<3>,  Prev: New Features Related to Type Hints<2>,  Up: What’s New In Python 3 10

1.5.4 Other Language Changes
----------------------------

   * The *note int: 19b. type has a new method *note int.bit_count():
     9d1, returning the number of ones in the binary expansion of a
     given integer, also known as the population count.  (Contributed by
     Niklas Fiekas in bpo-29882(1).)

   * The views returned by *note dict.keys(): 9d2, *note dict.values():
     9d3. and *note dict.items(): 9d4. now all have a ‘mapping’
     attribute that gives a *note types.MappingProxyType: 699. object
     wrapping the original dictionary.  (Contributed by Dennis Sweeney
     in bpo-40890(2).)

   * PEP 618(3): The *note zip(): 1a0. function now has an optional
     ‘strict’ flag, used to require that all the iterables have an equal
     length.

   * Builtin and extension functions that take integer arguments no
     longer accept *note Decimal: 1fe.s, *note Fraction: 213.s and other
     objects that can be converted to integers only with a loss (e.g.
     that have the *note __int__(): 19d. method but do not have the
     *note __index__(): 19e. method).  (Contributed by Serhiy Storchaka
     in bpo-37999(4).)

   * If *note object.__ipow__(): 9d5. returns *note NotImplemented: 1a2,
     the operator will correctly fall back to *note object.__pow__():
     9d6. and *note object.__rpow__(): 1a5. as expected.  (Contributed
     by Alex Shkop in bpo-38302(5).)

   * Assignment expressions can now be used unparenthesized within set
     literals and set comprehensions, as well as in sequence indexes
     (but not slices).

   * Functions have a new ‘__builtins__’ attribute which is used to look
     for builtin symbols when a function is executed, instead of looking
     into ‘__globals__['__builtins__']’.  The attribute is initialized
     from ‘__globals__["__builtins__"]’ if it exists, else from the
     current builtins.  (Contributed by Mark Shannon in bpo-42990(6).)

   * Two new builtin functions – *note aiter(): 9d7. and *note anext():
     9d8. have been added to provide asynchronous counterparts to *note
     iter(): 9d9. and *note next(): 9da, respectively.  (Contributed by
     Joshua Bronson, Daniel Pope, and Justin Wang in bpo-31861(7).)

   * Static methods (*note @staticmethod: 453.) and class methods (*note
     @classmethod: 48f.) now inherit the method attributes
     (‘__module__’, ‘__name__’, ‘__qualname__’, ‘__doc__’,
     ‘__annotations__’) and have a new ‘__wrapped__’ attribute.
     Moreover, static methods are now callable as regular functions.
     (Contributed by Victor Stinner in bpo-43682(8).)

   * Annotations for complex targets (everything beside ‘simple name’
     targets defined by PEP 526(9)) no longer cause any runtime effects
     with ‘from __future__ import annotations’.  (Contributed by Batuhan
     Taskaya in bpo-42737(10).)

   * Class and module objects now lazy-create empty annotations dicts on
     demand.  The annotations dicts are stored in the object’s
     ‘__dict__’ for backwards compatibility.  This improves the best
     practices for working with ‘__annotations__’; for more information,
     please see *note Annotations Best Practices: 9db.  (Contributed by
     Larry Hastings in bpo-43901(11).)

   * Annotations consist of ‘yield’, ‘yield from’, ‘await’ or named
     expressions are now forbidden under ‘from __future__ import
     annotations’ due to their side effects.  (Contributed by Batuhan
     Taskaya in bpo-42725(12).)

   * Usage of unbound variables, ‘super()’ and other expressions that
     might alter the processing of symbol table as annotations are now
     rendered effectless under ‘from __future__ import annotations’.
     (Contributed by Batuhan Taskaya in bpo-42725(13).)

   * Hashes of NaN values of both *note float: 196. type and *note
     decimal.Decimal: 1fe. type now depend on object identity.
     Formerly, they always hashed to ‘0’ even though NaN values are not
     equal to one another.  This caused potentially quadratic runtime
     behavior due to excessive hash collisions when creating
     dictionaries and sets containing multiple NaNs.  (Contributed by
     Raymond Hettinger in bpo-43475(14).)

   * A *note SyntaxError: 18e. (instead of a *note NameError: 452.) will
     be raised when deleting the *note __debug__: 9dc. constant.
     (Contributed by Donghee Na in bpo-45000(15).)

   * *note SyntaxError: 18e. exceptions now have ‘end_lineno’ and
     ‘end_offset’ attributes.  They will be ‘None’ if not determined.
     (Contributed by Pablo Galindo in bpo-43914(16).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29882

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40890

   (3) https://peps.python.org/pep-0618/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=37999

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38302

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42990

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31861

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43682

   (9) https://peps.python.org/pep-0526/

   (10) https://bugs.python.org/issue?@action=redirect&bpo=42737

   (11) https://bugs.python.org/issue?@action=redirect&bpo=43901

   (12) https://bugs.python.org/issue?@action=redirect&bpo=42725

   (13) https://bugs.python.org/issue?@action=redirect&bpo=42725

   (14) https://bugs.python.org/issue?@action=redirect&bpo=43475

   (15) https://bugs.python.org/issue?@action=redirect&bpo=45000

   (16) https://bugs.python.org/issue?@action=redirect&bpo=43914


File: python.info,  Node: New Modules<3>,  Next: Improved Modules<3>,  Prev: Other Language Changes<3>,  Up: What’s New In Python 3 10

1.5.5 New Modules
-----------------

   * None.


File: python.info,  Node: Improved Modules<3>,  Next: Optimizations<4>,  Prev: New Modules<3>,  Up: What’s New In Python 3 10

1.5.6 Improved Modules
----------------------

* Menu:

* asyncio: asyncio<7>.
* argparse: argparse<4>.
* array: array<3>.
* asynchat, asyncore, smtpd: asynchat asyncore smtpd.
* base64: base64<3>.
* bdb: bdb<2>.
* bisect::
* codecs::
* collections.abc: collections abc.
* contextlib: contextlib<2>.
* curses: curses<2>.
* dataclasses: dataclasses<2>.
* distutils: distutils<2>.
* doctest: doctest<2>.
* encodings::
* enum: enum<4>.
* fileinput::
* faulthandler: faulthandler<2>.
* gc: gc<2>.
* glob: glob<2>.
* hashlib: hashlib<3>.
* hmac: hmac<2>.
* IDLE and idlelib: IDLE and idlelib<2>.
* importlib.metadata: importlib metadata<2>.
* inspect: inspect<4>.
* itertools: itertools<4>.
* linecache: linecache<2>.
* os: os<5>.
* os.path: os path<4>.
* pathlib: pathlib<8>.
* platform: platform<3>.
* pprint::
* py_compile::
* pyclbr::
* shelve::
* statistics: statistics<2>.
* site: site<2>.
* socket: socket<3>.
* ssl: ssl<4>.
* sqlite3: sqlite3<6>.
* sys: sys<5>.
* _thread::
* threading: threading<4>.
* traceback: traceback<3>.
* types: types<4>.
* typing: typing<6>.
* unittest: unittest<6>.
* urllib.parse: urllib parse.
* xml: xml<2>.
* zipimport: zipimport<3>.


File: python.info,  Node: asyncio<7>,  Next: argparse<4>,  Up: Improved Modules<3>

1.5.6.1 asyncio
...............

Add missing *note connect_accepted_socket(): 9e0. method.  (Contributed
by Alex Grönholm in bpo-41332(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41332


File: python.info,  Node: argparse<4>,  Next: array<3>,  Prev: asyncio<7>,  Up: Improved Modules<3>

1.5.6.2 argparse
................

Misleading phrase «optional arguments» was replaced with «options» in
argparse help.  Some tests might require adaptation if they rely on
exact output match.  (Contributed by Raymond Hettinger in bpo-9694(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9694


File: python.info,  Node: array<3>,  Next: asynchat asyncore smtpd,  Prev: argparse<4>,  Up: Improved Modules<3>

1.5.6.3 array
.............

The *note index(): 9e3. method of *note array.array: 4bf. now has
optional 'start' and 'stop' parameters.  (Contributed by Anders
Lorentsen and Zackery Spytz in bpo-31956(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31956


File: python.info,  Node: asynchat asyncore smtpd,  Next: base64<3>,  Prev: array<3>,  Up: Improved Modules<3>

1.5.6.4 asynchat, asyncore, smtpd
.................................

These modules have been marked as deprecated in their module
documentation since Python 3.6.  An import-time *note
DeprecationWarning: 1a3. has now been added to all three of these
modules.


File: python.info,  Node: base64<3>,  Next: bdb<2>,  Prev: asynchat asyncore smtpd,  Up: Improved Modules<3>

1.5.6.5 base64
..............

Add *note base64.b32hexencode(): 9e6. and *note base64.b32hexdecode():
9e7. to support the Base32 Encoding with Extended Hex Alphabet.


File: python.info,  Node: bdb<2>,  Next: bisect,  Prev: base64<3>,  Up: Improved Modules<3>

1.5.6.6 bdb
...........

Add ‘clearBreakpoints()’ to reset all set breakpoints.  (Contributed by
Irit Katriel in bpo-24160(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24160


File: python.info,  Node: bisect,  Next: codecs,  Prev: bdb<2>,  Up: Improved Modules<3>

1.5.6.7 bisect
..............

Added the possibility of providing a 'key' function to the APIs in the
*note bisect: 12. module.  (Contributed by Raymond Hettinger in
bpo-4356(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4356


File: python.info,  Node: codecs,  Next: collections abc,  Prev: bisect,  Up: Improved Modules<3>

1.5.6.8 codecs
..............

Add a *note codecs.unregister(): 9eb. function to unregister a codec
search function.  (Contributed by Hai Shi in bpo-41842(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41842


File: python.info,  Node: collections abc,  Next: contextlib<2>,  Prev: codecs,  Up: Improved Modules<3>

1.5.6.9 collections.abc
.......................

The ‘__args__’ of the *note parameterized generic: 8c2. for *note
collections.abc.Callable: 9ed. are now consistent with *note
typing.Callable: 9ca.  *note collections.abc.Callable: 9ed. generic now
flattens type parameters, similar to what *note typing.Callable: 9ca.
currently does.  This means that ‘collections.abc.Callable[[int, str],
str]’ will have ‘__args__’ of ‘(int, str, str)’; previously this was
‘([int, str], str)’.  To allow this change, *note types.GenericAlias:
9ee. can now be subclassed, and a subclass will be returned when
subscripting the *note collections.abc.Callable: 9ed. type.  Note that a
*note TypeError: 198. may be raised for invalid forms of parameterizing
*note collections.abc.Callable: 9ed. which may have passed silently in
Python 3.9.  (Contributed by Ken Jin in bpo-42195(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42195


File: python.info,  Node: contextlib<2>,  Next: curses<2>,  Prev: collections abc,  Up: Improved Modules<3>

1.5.6.10 contextlib
...................

Add a *note contextlib.aclosing(): 9f0. context manager to safely close
async generators and objects representing asynchronously released
resources.  (Contributed by Joongi Kim and John Belmonte in
bpo-41229(1).)

Add asynchronous context manager support to *note
contextlib.nullcontext(): 9f1.  (Contributed by Tom Gringauz in
bpo-41543(2).)

Add *note AsyncContextDecorator: 9f2, for supporting usage of async
context managers as decorators.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41229

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41543


File: python.info,  Node: curses<2>,  Next: dataclasses<2>,  Prev: contextlib<2>,  Up: Improved Modules<3>

1.5.6.11 curses
...............

The extended color functions added in ncurses 6.1 will be used
transparently by *note curses.color_content(): 9f4, *note
curses.init_color(): 9f5, *note curses.init_pair(): 9f6, and *note
curses.pair_content(): 9f7.  A new function, *note
curses.has_extended_color_support(): 9f8, indicates whether extended
color support is provided by the underlying ncurses library.
(Contributed by Jeffrey Kintscher and Hans Petter Jansson in
bpo-36982(1).)

The ‘BUTTON5_*’ constants are now exposed in the *note curses: 2f.
module if they are provided by the underlying curses library.
(Contributed by Zackery Spytz in bpo-39273(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36982

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39273


File: python.info,  Node: dataclasses<2>,  Next: distutils<2>,  Prev: curses<2>,  Up: Improved Modules<3>

1.5.6.12 dataclasses
....................

* Menu:

* __slots__::
* Keyword-only fields::


File: python.info,  Node: __slots__,  Next: Keyword-only fields,  Up: dataclasses<2>

1.5.6.13 __slots__
..................

Added ‘slots’ parameter in *note dataclasses.dataclass(): 4e2.
decorator.  (Contributed by Yurii Karabas in bpo-42269(1))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42269


File: python.info,  Node: Keyword-only fields,  Prev: __slots__,  Up: dataclasses<2>

1.5.6.14 Keyword-only fields
............................

dataclasses now supports fields that are keyword-only in the generated
__init__ method.  There are a number of ways of specifying keyword-only
fields.

You can say that every field is keyword-only:

     from dataclasses import dataclass

     @dataclass(kw_only=True)
     class Birthday:
         name: str
         birthday: datetime.date

Both ‘name’ and ‘birthday’ are keyword-only parameters to the generated
__init__ method.

You can specify keyword-only on a per-field basis:

     from dataclasses import dataclass, field

     @dataclass
     class Birthday:
         name: str
         birthday: datetime.date = field(kw_only=True)

Here only ‘birthday’ is keyword-only.  If you set ‘kw_only’ on
individual fields, be aware that there are rules about re-ordering
fields due to keyword-only fields needing to follow non-keyword-only
fields.  See the full dataclasses documentation for details.

You can also specify that all fields following a KW_ONLY marker are
keyword-only.  This will probably be the most common usage:

     from dataclasses import dataclass, KW_ONLY

     @dataclass
     class Point:
         x: float
         y: float
         _: KW_ONLY
         z: float = 0.0
         t: float = 0.0

Here, ‘z’ and ‘t’ are keyword-only parameters, while ‘x’ and ‘y’ are
not.  (Contributed by Eric V. Smith in bpo-43532(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43532


File: python.info,  Node: distutils<2>,  Next: doctest<2>,  Prev: dataclasses<2>,  Up: Improved Modules<3>

1.5.6.15 distutils
..................

The entire ‘distutils’ package is deprecated, to be removed in Python
3.12.  Its functionality for specifying package builds has already been
completely replaced by third-party packages ‘setuptools’ and
‘packaging’, and most other commonly used APIs are available elsewhere
in the standard library (such as *note platform: af, *note shutil: ca,
*note subprocess: dc. or *note sysconfig: e1.).  There are no plans to
migrate any other functionality from ‘distutils’, and applications that
are using other functions should plan to make private copies of the
code.  Refer to PEP 632(1) for discussion.

The ‘bdist_wininst’ command deprecated in Python 3.8 has been removed.
The ‘bdist_wheel’ command is now recommended to distribute binary
packages on Windows.  (Contributed by Victor Stinner in bpo-42802(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0632/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42802


File: python.info,  Node: doctest<2>,  Next: encodings,  Prev: distutils<2>,  Up: Improved Modules<3>

1.5.6.16 doctest
................

When a module does not define ‘__loader__’, fall back to
‘__spec__.loader’.  (Contributed by Brett Cannon in bpo-42133(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42133


File: python.info,  Node: encodings,  Next: enum<4>,  Prev: doctest<2>,  Up: Improved Modules<3>

1.5.6.17 encodings
..................

*note encodings.normalize_encoding(): 9ff. now ignores non-ASCII
characters.  (Contributed by Hai Shi in bpo-39337(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39337


File: python.info,  Node: enum<4>,  Next: fileinput,  Prev: encodings,  Up: Improved Modules<3>

1.5.6.18 enum
.............

*note Enum: 843. *note __repr__(): 830. now returns
‘enum_name.member_name’ and *note __str__(): 831. now returns
‘member_name’.  Stdlib enums available as module constants have a *note
repr(): 1c1. of ‘module_name.member_name’.  (Contributed by Ethan Furman
in bpo-40066(1).)

Add *note enum.StrEnum: 82e. for enums where all members are strings.
(Contributed by Ethan Furman in bpo-41816(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40066

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41816


File: python.info,  Node: fileinput,  Next: faulthandler<2>,  Prev: enum<4>,  Up: Improved Modules<3>

1.5.6.19 fileinput
..................

Add 'encoding' and 'errors' parameters in *note fileinput.input(): a02.
and *note fileinput.FileInput: 941.  (Contributed by Inada Naoki in
bpo-43712(1).)

*note fileinput.hook_compressed(): a03. now returns *note TextIOWrapper:
9c0. object when 'mode' is «r» and file is compressed, like uncompressed
files.  (Contributed by Inada Naoki in bpo-5758(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43712

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5758


File: python.info,  Node: faulthandler<2>,  Next: gc<2>,  Prev: fileinput,  Up: Improved Modules<3>

1.5.6.20 faulthandler
.....................

The *note faulthandler: 5c. module now detects if a fatal error occurs
during a garbage collector collection.  (Contributed by Victor Stinner
in bpo-44466(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44466


File: python.info,  Node: gc<2>,  Next: glob<2>,  Prev: faulthandler<2>,  Up: Improved Modules<3>

1.5.6.21 gc
...........

Add audit hooks for *note gc.get_objects(): a06, *note
gc.get_referrers(): a07. and *note gc.get_referents(): a08.
(Contributed by Pablo Galindo in bpo-43439(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43439


File: python.info,  Node: glob<2>,  Next: hashlib<3>,  Prev: gc<2>,  Up: Improved Modules<3>

1.5.6.22 glob
.............

Add the 'root_dir' and 'dir_fd' parameters in *note glob(): 5a0. and
*note iglob(): a0a. which allow to specify the root directory for
searching.  (Contributed by Serhiy Storchaka in bpo-38144(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38144


File: python.info,  Node: hashlib<3>,  Next: hmac<2>,  Prev: glob<2>,  Up: Improved Modules<3>

1.5.6.23 hashlib
................

The hashlib module requires OpenSSL 1.1.1 or newer.  (Contributed by
Christian Heimes in PEP 644(1) and bpo-43669(2).)

The hashlib module has preliminary support for OpenSSL 3.0.0.
(Contributed by Christian Heimes in bpo-38820(3) and other issues.)

The pure-Python fallback of *note pbkdf2_hmac(): 734. is deprecated.  In
the future PBKDF2-HMAC will only be available when Python has been built
with OpenSSL support.  (Contributed by Christian Heimes in
bpo-43880(4).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0644/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43669

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38820

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43880


File: python.info,  Node: hmac<2>,  Next: IDLE and idlelib<2>,  Prev: hashlib<3>,  Up: Improved Modules<3>

1.5.6.24 hmac
.............

The hmac module now uses OpenSSL’s HMAC implementation internally.
(Contributed by Christian Heimes in bpo-40645(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40645


File: python.info,  Node: IDLE and idlelib<2>,  Next: importlib metadata<2>,  Prev: hmac<2>,  Up: Improved Modules<3>

1.5.6.25 IDLE and idlelib
.........................

Make IDLE invoke *note sys.excepthook(): a0e. (when started without
“-n”).  User hooks were previously ignored.  (Contributed by Ken Hilton
in bpo-43008(1).)

Rearrange the settings dialog.  Split the General tab into Windows and
Shell/Ed tabs.  Move help sources, which extend the Help menu, to the
Extensions tab.  Make space for new options and shorten the dialog.  The
latter makes the dialog better fit small screens.  (Contributed by Terry
Jan Reedy in bpo-40468(2).)  Move the indent space setting from the Font
tab to the new Windows tab.  (Contributed by Mark Roseman and Terry Jan
Reedy in bpo-33962(3).)

The changes above were backported to a 3.9 maintenance release.

Add a Shell sidebar.  Move the primary prompt (“>>>”) to the sidebar.
Add secondary prompts (”…”) to the sidebar.  Left click and optional
drag selects one or more lines of text, as with the editor line number
sidebar.  Right click after selecting text lines displays a context menu
with “copy with prompts”.  This zips together prompts from the sidebar
with lines from the selected text.  This option also appears on the
context menu for the text.  (Contributed by Tal Einat in bpo-37903(4).)

Use spaces instead of tabs to indent interactive code.  This makes
interactive code entries “look right”.  Making this feasible was a major
motivation for adding the shell sidebar.  (Contributed by Terry Jan
Reedy in bpo-37892(5).)

Highlight the new *note soft keywords: a0f. *note match: a10, *note
case: a10, and *note _: a11. in pattern-matching statements.  However,
this highlighting is not perfect and will be incorrect in some rare
cases, including some ‘_’-s in ‘case’ patterns.  (Contributed by Tal
Einat in bpo-44010(6).)

New in 3.10 maintenance releases.

Apply syntax highlighting to ‘.pyi’ files.  (Contributed by Alex Waygood
and Terry Jan Reedy in bpo-45447(7).)

Include prompts when saving Shell with inputs and outputs.  (Contributed
by Terry Jan Reedy in gh-95191(8).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43008

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40468

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33962

   (4) https://bugs.python.org/issue?@action=redirect&bpo=37903

   (5) https://bugs.python.org/issue?@action=redirect&bpo=37892

   (6) https://bugs.python.org/issue?@action=redirect&bpo=44010

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45447

   (8) https://github.com/python/cpython/issues/95191


File: python.info,  Node: importlib metadata<2>,  Next: inspect<4>,  Prev: IDLE and idlelib<2>,  Up: Improved Modules<3>

1.5.6.26 importlib.metadata
...........................

Feature parity with ‘importlib_metadata’ 4.6 (history(1)).

*note importlib.metadata entry points: 589. now provide a nicer
experience for selecting entry points by group and name through a new
*note importlib.metadata.EntryPoints: 589. class.  See the Compatibility
Note in the docs for more info on the deprecation and usage.

Added *note importlib.metadata.packages_distributions(): a13. for
resolving top-level Python modules and packages to their *note
importlib.metadata.Distribution: a14.

   ---------- Footnotes ----------

   (1) https://importlib-metadata.readthedocs.io/en/latest/history.html


File: python.info,  Node: inspect<4>,  Next: itertools<4>,  Prev: importlib metadata<2>,  Up: Improved Modules<3>

1.5.6.27 inspect
................

When a module does not define ‘__loader__’, fall back to
‘__spec__.loader’.  (Contributed by Brett Cannon in bpo-42133(1).)

Add *note inspect.get_annotations(): a16, which safely computes the
annotations defined on an object.  It works around the quirks of
accessing the annotations on various types of objects, and makes very
few assumptions about the object it examines.  *note
inspect.get_annotations(): a16. can also correctly un-stringize
stringized annotations.  *note inspect.get_annotations(): a16. is now
considered best practice for accessing the annotations dict defined on
any Python object; for more information on best practices for working
with annotations, please see *note Annotations Best Practices: 9db.
Relatedly, *note inspect.signature(): 22f, *note
inspect.Signature.from_callable(): 943, and
‘inspect.Signature.from_function()’ now call *note
inspect.get_annotations(): a16. to retrieve annotations.  This means
*note inspect.signature(): 22f. and *note
inspect.Signature.from_callable(): 943. can also now un-stringize
stringized annotations.  (Contributed by Larry Hastings in
bpo-43817(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42133

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43817


File: python.info,  Node: itertools<4>,  Next: linecache<2>,  Prev: inspect<4>,  Up: Improved Modules<3>

1.5.6.28 itertools
..................

Add *note itertools.pairwise(): a18.  (Contributed by Raymond Hettinger
in bpo-38200(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38200


File: python.info,  Node: linecache<2>,  Next: os<5>,  Prev: itertools<4>,  Up: Improved Modules<3>

1.5.6.29 linecache
..................

When a module does not define ‘__loader__’, fall back to
‘__spec__.loader’.  (Contributed by Brett Cannon in bpo-42133(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42133


File: python.info,  Node: os<5>,  Next: os path<4>,  Prev: linecache<2>,  Up: Improved Modules<3>

1.5.6.30 os
...........

Add *note os.cpu_count(): 4dc. support for VxWorks RTOS. (Contributed by
Peixing Xin in bpo-41440(1).)

Add a new function *note os.eventfd(): a1b. and related helpers to wrap
the ‘eventfd2’ syscall on Linux.  (Contributed by Christian Heimes in
bpo-41001(2).)

Add *note os.splice(): a1c. that allows to move data between two file
descriptors without copying between kernel address space and user
address space, where one of the file descriptors must refer to a pipe.
(Contributed by Pablo Galindo in bpo-41625(3).)

Add *note O_EVTONLY: a1d, *note O_FSYNC: a1e, *note O_SYMLINK: a1f. and
*note O_NOFOLLOW_ANY: a20. for macOS. (Contributed by Donghee Na in
bpo-43106(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41440

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41001

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41625

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43106


File: python.info,  Node: os path<4>,  Next: pathlib<8>,  Prev: os<5>,  Up: Improved Modules<3>

1.5.6.31 os.path
................

*note os.path.realpath(): 262. now accepts a 'strict' keyword-only
argument.  When set to ‘True’, *note OSError: 2c0. is raised if a path
doesn’t exist or a symlink loop is encountered.  (Contributed by Barney
Gale in bpo-43757(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43757


File: python.info,  Node: pathlib<8>,  Next: platform<3>,  Prev: os path<4>,  Up: Improved Modules<3>

1.5.6.32 pathlib
................

Add slice support to *note PurePath.parents: a23.  (Contributed by
Joshua Cannon in bpo-35498(1).)

Add negative indexing support to *note PurePath.parents: a23.
(Contributed by Yaroslav Pankovych in bpo-21041(2).)

Add *note Path.hardlink_to: a24. method that supersedes ‘link_to()’.
The new method has the same argument order as *note symlink_to(): a25.
(Contributed by Barney Gale in bpo-39950(3).)

*note pathlib.Path.stat(): a26. and *note chmod(): a27. now accept a
'follow_symlinks' keyword-only argument for consistency with
corresponding functions in the *note os: a5. module.  (Contributed by
Barney Gale in bpo-39906(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35498

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21041

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39950

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39906


File: python.info,  Node: platform<3>,  Next: pprint,  Prev: pathlib<8>,  Up: Improved Modules<3>

1.5.6.33 platform
.................

Add *note platform.freedesktop_os_release(): a29. to retrieve operation
system identification from freedesktop.org os-release(1) standard file.
(Contributed by Christian Heimes in bpo-28468(2).)

   ---------- Footnotes ----------

   (1) https://www.freedesktop.org/software/systemd/man/os-release.html

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28468


File: python.info,  Node: pprint,  Next: py_compile,  Prev: platform<3>,  Up: Improved Modules<3>

1.5.6.34 pprint
...............

*note pprint.pprint(): a2b. now accepts a new ‘underscore_numbers’
keyword argument.  (Contributed by sblondon in bpo-42914(1).)

*note pprint: b3. can now pretty-print *note dataclasses.dataclass: 4e2.
instances.  (Contributed by Lewis Gaul in bpo-43080(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42914

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43080


File: python.info,  Node: py_compile,  Next: pyclbr,  Prev: pprint,  Up: Improved Modules<3>

1.5.6.35 py_compile
...................

Add ‘--quiet’ option to command-line interface of *note py_compile: b8.
(Contributed by Gregory Schevchenko in bpo-38731(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38731


File: python.info,  Node: pyclbr,  Next: shelve,  Prev: py_compile,  Up: Improved Modules<3>

1.5.6.36 pyclbr
...............

Add an ‘end_lineno’ attribute to the ‘Function’ and ‘Class’ objects in
the tree returned by *note pyclbr.readmodule(): a2e. and *note
pyclbr.readmodule_ex(): a2f.  It matches the existing (start) ‘lineno’.
(Contributed by Aviral Srivastava in bpo-38307(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38307


File: python.info,  Node: shelve,  Next: statistics<2>,  Prev: pyclbr,  Up: Improved Modules<3>

1.5.6.37 shelve
...............

The *note shelve: c8. module now uses *note pickle.DEFAULT_PROTOCOL:
a31. by default instead of *note pickle: ab. protocol ‘3’ when creating
shelves.  (Contributed by Zackery Spytz in bpo-34204(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34204


File: python.info,  Node: statistics<2>,  Next: site<2>,  Prev: shelve,  Up: Improved Modules<3>

1.5.6.38 statistics
...................

Add *note covariance(): a33, Pearson’s *note correlation(): 6e4, and
simple *note linear_regression(): a34. functions.  (Contributed by
Tymoteusz Wołodźko in bpo-38490(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38490


File: python.info,  Node: site<2>,  Next: socket<3>,  Prev: statistics<2>,  Up: Improved Modules<3>

1.5.6.39 site
.............

When a module does not define ‘__loader__’, fall back to
‘__spec__.loader’.  (Contributed by Brett Cannon in bpo-42133(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42133


File: python.info,  Node: socket<3>,  Next: ssl<4>,  Prev: site<2>,  Up: Improved Modules<3>

1.5.6.40 socket
...............

The exception *note socket.timeout: a37. is now an alias of *note
TimeoutError: a38.  (Contributed by Christian Heimes in bpo-42413(1).)

Add option to create MPTCP sockets with ‘IPPROTO_MPTCP’ (Contributed by
Rui Cunha in bpo-43571(2).)

Add ‘IP_RECVTOS’ option to receive the type of service (ToS) or DSCP/ECN
fields (Contributed by Georg Sauthoff in bpo-44077(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42413

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43571

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44077


File: python.info,  Node: ssl<4>,  Next: sqlite3<6>,  Prev: socket<3>,  Up: Improved Modules<3>

1.5.6.41 ssl
............

The ssl module requires OpenSSL 1.1.1 or newer.  (Contributed by
Christian Heimes in PEP 644(1) and bpo-43669(2).)

The ssl module has preliminary support for OpenSSL 3.0.0 and new option
*note OP_IGNORE_UNEXPECTED_EOF: a3a.  (Contributed by Christian Heimes
in bpo-38820(3), bpo-43794(4), bpo-43788(5), bpo-43791(6), bpo-43799(7),
bpo-43920(8), bpo-43789(9), and bpo-43811(10).)

Deprecated function and use of deprecated constants now result in a
*note DeprecationWarning: 1a3.  *note ssl.SSLContext.options: a3b. has
*note OP_NO_SSLv2: a3c. and *note OP_NO_SSLv3: a3d. set by default and
therefore cannot warn about setting the flag again.  The *note
deprecation section: a3e. has a list of deprecated features.
(Contributed by Christian Heimes in bpo-43880(11).)

The ssl module now has more secure default settings.  Ciphers without
forward secrecy or SHA-1 MAC are disabled by default.  Security level 2
prohibits weak RSA, DH, and ECC keys with less than 112 bits of
security.  *note SSLContext: 357. defaults to minimum protocol version
TLS 1.2.  Settings are based on Hynek Schlawack’s research.
(Contributed by Christian Heimes in bpo-43998(12).)

The deprecated protocols SSL 3.0, TLS 1.0, and TLS 1.1 are no longer
officially supported.  Python does not block them actively.  However
OpenSSL build options, distro configurations, vendor patches, and cipher
suites may prevent a successful handshake.

Add a 'timeout' parameter to the *note ssl.get_server_certificate():
a3f. function.  (Contributed by Zackery Spytz in bpo-31870(13).)

The ssl module uses heap-types and multi-phase initialization.
(Contributed by Christian Heimes in bpo-42333(14).)

A new verify flag *note VERIFY_X509_PARTIAL_CHAIN: 481. has been added.
(Contributed by l0x in bpo-40849(15).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0644/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43669

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38820

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43794

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43788

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43791

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43799

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43920

   (9) https://bugs.python.org/issue?@action=redirect&bpo=43789

   (10) https://bugs.python.org/issue?@action=redirect&bpo=43811

   (11) https://bugs.python.org/issue?@action=redirect&bpo=43880

   (12) https://bugs.python.org/issue?@action=redirect&bpo=43998

   (13) https://bugs.python.org/issue?@action=redirect&bpo=31870

   (14) https://bugs.python.org/issue?@action=redirect&bpo=42333

   (15) https://bugs.python.org/issue?@action=redirect&bpo=40849


File: python.info,  Node: sqlite3<6>,  Next: sys<5>,  Prev: ssl<4>,  Up: Improved Modules<3>

1.5.6.42 sqlite3
................

Add audit events for *note connect(): 5a6, *note
enable_load_extension(): a41, and *note load_extension(): 6e0.
(Contributed by Erlend E. Aasland in bpo-43762(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43762


File: python.info,  Node: sys<5>,  Next: _thread,  Prev: sqlite3<6>,  Up: Improved Modules<3>

1.5.6.43 sys
............

Add *note sys.orig_argv: a43. attribute: the list of the original
command line arguments passed to the Python executable.  (Contributed by
Victor Stinner in bpo-23427(1).)

Add *note sys.stdlib_module_names: a44, containing the list of the
standard library module names.  (Contributed by Victor Stinner in
bpo-42955(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23427

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42955


File: python.info,  Node: _thread,  Next: threading<4>,  Prev: sys<5>,  Up: Improved Modules<3>

1.5.6.44 _thread
................

*note _thread.interrupt_main(): a46. now takes an optional signal number
to simulate (the default is still *note signal.SIGINT: 253.).
(Contributed by Antoine Pitrou in bpo-43356(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43356


File: python.info,  Node: threading<4>,  Next: traceback<3>,  Prev: _thread,  Up: Improved Modules<3>

1.5.6.45 threading
..................

Add *note threading.gettrace(): a48. and *note threading.getprofile():
a49. to retrieve the functions set by *note threading.settrace(): a4a.
and *note threading.setprofile(): a4b. respectively.  (Contributed by
Mario Corchero in bpo-42251(1).)

Add *note threading.__excepthook__: a4c. to allow retrieving the
original value of *note threading.excepthook(): a4d. in case it is set
to a broken or a different value.  (Contributed by Mario Corchero in
bpo-42308(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42251

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42308


File: python.info,  Node: traceback<3>,  Next: types<4>,  Prev: threading<4>,  Up: Improved Modules<3>

1.5.6.46 traceback
..................

The *note format_exception(): a4f, *note format_exception_only(): a50,
and *note print_exception(): a51. functions can now take an exception
object as a positional-only argument.  (Contributed by Zackery Spytz and
Matthias Bussonnier in bpo-26389(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26389


File: python.info,  Node: types<4>,  Next: typing<6>,  Prev: traceback<3>,  Up: Improved Modules<3>

1.5.6.47 types
..............

Reintroduce the *note types.EllipsisType: a53, *note types.NoneType:
a54. and *note types.NotImplementedType: a55. classes, providing a new
set of types readily interpretable by type checkers.  (Contributed by
Bas van Beek in bpo-41810(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41810


File: python.info,  Node: typing<6>,  Next: unittest<6>,  Prev: types<4>,  Up: Improved Modules<3>

1.5.6.48 typing
...............

For major changes, see *note New Features Related to Type Hints: 9c3.

The behavior of *note typing.Literal: a57. was changed to conform with
PEP 586(1) and to match the behavior of static type checkers specified
in the PEP.

  1. ‘Literal’ now de-duplicates parameters.

  2. Equality comparisons between ‘Literal’ objects are now order
     independent.

  3. ‘Literal’ comparisons now respect types.  For example, ‘Literal[0]
     == Literal[False]’ previously evaluated to ‘True’.  It is now
     ‘False’.  To support this change, the internally used type cache
     now supports differentiating types.

  4. ‘Literal’ objects will now raise a *note TypeError: 198. exception
     during equality comparisons if any of their parameters are not
     *note hashable: 825.  Note that declaring ‘Literal’ with unhashable
     parameters will not throw an error:

          >>> from typing import Literal
          >>> Literal[{0}]
          >>> Literal[{0}] == Literal[{False}]
          Traceback (most recent call last):
            File "<stdin>", line 1, in <module>
          TypeError: unhashable type: 'set'

(Contributed by Yurii Karabas in bpo-42345(2).)

Add new function *note typing.is_typeddict(): a58. to introspect if an
annotation is a *note typing.TypedDict: 332.  (Contributed by Patrick
Reader in bpo-41792(3).)

Subclasses of ‘typing.Protocol’ which only have data variables declared
will now raise a ‘TypeError’ when checked with ‘isinstance’ unless they
are decorated with *note runtime_checkable(): 675.  Previously, these
checks passed silently.  Users should decorate their subclasses with the
‘runtime_checkable()’ decorator if they want runtime protocols.
(Contributed by Yurii Karabas in bpo-38908(4).)

Importing from the ‘typing.io’ and ‘typing.re’ submodules will now emit
*note DeprecationWarning: 1a3.  These submodules have been deprecated
since Python 3.8 and will be removed in a future version of Python.
Anything belonging to those submodules should be imported directly from
*note typing: 10a. instead.  (Contributed by Sebastian Rittau in
bpo-38291(5).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0586/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42345

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41792

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38908

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38291


File: python.info,  Node: unittest<6>,  Next: urllib parse,  Prev: typing<6>,  Up: Improved Modules<3>

1.5.6.49 unittest
.................

Add new method *note assertNoLogs(): a5a. to complement the existing
*note assertLogs(): a5b.  (Contributed by Kit Yan Choi in bpo-39385(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39385


File: python.info,  Node: urllib parse,  Next: xml<2>,  Prev: unittest<6>,  Up: Improved Modules<3>

1.5.6.50 urllib.parse
.....................

Python versions earlier than Python 3.10 allowed using both ‘;’ and ‘&’
as query parameter separators in *note urllib.parse.parse_qs(): 31f. and
*note urllib.parse.parse_qsl(): 31e.  Due to security concerns, and to
conform with newer W3C recommendations, this has been changed to allow
only a single separator key, with ‘&’ as the default.  This change also
affects ‘cgi.parse()’ and ‘cgi.parse_multipart()’ as they use the
affected functions internally.  For more details, please see their
respective documentation.  (Contributed by Adam Goldschmidt, Senthil
Kumaran and Ken Jin in bpo-42967(1).)

The presence of newline or tab characters in parts of a URL allows for
some forms of attacks.  Following the WHATWG specification that updates
RFC 3986(2), ASCII newline ‘\n’, ‘\r’ and tab ‘\t’ characters are
stripped from the URL by the parser in *note urllib.parse: 110.
preventing such attacks.  The removal characters are controlled by a new
module level variable ‘urllib.parse._UNSAFE_URL_BYTES_TO_REMOVE’.  (See
gh-88048(3))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42967

   (2) https://datatracker.ietf.org/doc/html/rfc3986.html

   (3) https://github.com/python/cpython/issues/88048


File: python.info,  Node: xml<2>,  Next: zipimport<3>,  Prev: urllib parse,  Up: Improved Modules<3>

1.5.6.51 xml
............

Add a *note LexicalHandler: a5e. class to the *note xml.sax.handler:
130. module.  (Contributed by Jonathan Gossage and Zackery Spytz in
bpo-35018(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35018


File: python.info,  Node: zipimport<3>,  Prev: xml<2>,  Up: Improved Modules<3>

1.5.6.52 zipimport
..................

Add methods related to PEP 451(1): *note find_spec(): a60, *note
zipimport.zipimporter.create_module(): a61, and *note
zipimport.zipimporter.exec_module(): 339.  (Contributed by Brett Cannon
in bpo-42131(2).)

Add *note invalidate_caches(): a62. method.  (Contributed by Desmond
Cheong in bpo-14678(3).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0451/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42131

   (3) https://bugs.python.org/issue?@action=redirect&bpo=14678


File: python.info,  Node: Optimizations<4>,  Next: Deprecated<4>,  Prev: Improved Modules<3>,  Up: What’s New In Python 3 10

1.5.7 Optimizations
-------------------

   * Constructors *note str(): 169, *note bytes(): 192. and *note
     bytearray(): 344. are now faster (around 30–40% for small objects).
     (Contributed by Serhiy Storchaka in bpo-41334(1).)

   * The *note runpy: c3. module now imports fewer modules.  The
     ‘python3 -m module-name’ command startup time is 1.4x faster in
     average.  On Linux, ‘python3 -I -m module-name’ imports 69 modules
     on Python 3.9, whereas it only imports 51 modules (-18) on Python
     3.10.  (Contributed by Victor Stinner in bpo-41006(2) and
     bpo-41718(3).)

   * The ‘LOAD_ATTR’ instruction now uses new «per opcode cache»
     mechanism.  It is about 36% faster now for regular attributes and
     44% faster for slots.  (Contributed by Pablo Galindo and Yury
     Selivanov in bpo-42093(4) and Guido van Rossum in bpo-42927(5),
     based on ideas implemented originally in PyPy and MicroPython.)

   * When building Python with *note -enable-optimizations: a64. now
     ‘-fno-semantic-interposition’ is added to both the compile and link
     line.  This speeds builds of the Python interpreter created with
     *note -enable-shared: a65. with ‘gcc’ by up to 30%.  See this
     article(6) for more details.  (Contributed by Victor Stinner and
     Pablo Galindo in bpo-38980(7).)

   * Use a new output buffer management code for *note bz2: 14. / *note
     lzma: 8e. / *note zlib: 139. modules, and add ‘.readall()’ function
     to ‘_compression.DecompressReader’ class.  bz2 decompression is now
     1.09x ~ 1.17x faster, lzma decompression 1.20x ~ 1.32x faster,
     ‘GzipFile.read(-1)’ 1.11x ~ 1.18x faster.  (Contributed by Ma Lin,
     reviewed by Gregory P. Smith, in bpo-41486(8))

   * When using stringized annotations, annotations dicts for functions
     are no longer created when the function is created.  Instead, they
     are stored as a tuple of strings, and the function object lazily
     converts this into the annotations dict on demand.  This
     optimization cuts the CPU time needed to define an annotated
     function by half.  (Contributed by Yurii Karabas and Inada Naoki in
     bpo-42202(9).)

   * Substring search functions such as ‘str1 in str2’ and
     ‘str2.find(str1)’ now sometimes use Crochemore & Perrin’s «Two-Way»
     string searching algorithm to avoid quadratic behavior on long
     strings.  (Contributed by Dennis Sweeney in bpo-41972(10))

   * Add micro-optimizations to ‘_PyType_Lookup()’ to improve type
     attribute cache lookup performance in the common case of cache
     hits.  This makes the interpreter 1.04 times faster on average.
     (Contributed by Dino Viehland in bpo-43452(11).)

   * The following built-in functions now support the faster PEP 590(12)
     vectorcall calling convention: *note map(): 19f, *note filter():
     a66, *note reversed(): a67, *note bool(): 3c3. and *note float():
     196.  (Contributed by Donghee Na and Jeroen Demeyer in
     bpo-43575(13), bpo-43287(14), bpo-41922(15), bpo-41873(16) and
     bpo-41870(17).)

   * *note BZ2File: a68. performance is improved by removing internal
     ‘RLock’.  This makes ‘BZ2File’ thread unsafe in the face of
     multiple simultaneous readers or writers, just like its equivalent
     classes in *note gzip: 6b. and *note lzma: 8e. have always been.
     (Contributed by Inada Naoki in bpo-43785(18).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41334

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41006

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41718

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42093

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42927

   (6) 
https://developers.redhat.com/blog/2020/06/25/red-hat-enterprise-linux-8-2-brings-faster-python-3-8-run-speeds/

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38980

   (8) https://bugs.python.org/issue?@action=redirect&bpo=41486

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42202

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41972

   (11) https://bugs.python.org/issue?@action=redirect&bpo=43452

   (12) https://peps.python.org/pep-0590/

   (13) https://bugs.python.org/issue?@action=redirect&bpo=43575

   (14) https://bugs.python.org/issue?@action=redirect&bpo=43287

   (15) https://bugs.python.org/issue?@action=redirect&bpo=41922

   (16) https://bugs.python.org/issue?@action=redirect&bpo=41873

   (17) https://bugs.python.org/issue?@action=redirect&bpo=41870

   (18) https://bugs.python.org/issue?@action=redirect&bpo=43785


File: python.info,  Node: Deprecated<4>,  Next: Removed<4>,  Prev: Optimizations<4>,  Up: What’s New In Python 3 10

1.5.8 Deprecated
----------------

   * Currently Python accepts numeric literals immediately followed by
     keywords, for example ‘0in x’, ‘1or x’, ‘0if 1else 2’.  It allows
     confusing and ambiguous expressions like ‘[0x1for x in y]’ (which
     can be interpreted as ‘[0x1 for x in y]’ or ‘[0x1f or x in y]’).
     Starting in this release, a deprecation warning is raised if the
     numeric literal is immediately followed by one of keywords *note
     and: 349, *note else: 17c, *note for: 34a, *note if: 181, *note in:
     34b, *note is: 34c. and *note or: 34d.  In future releases it will
     be changed to syntax warning, and finally to syntax error.
     (Contributed by Serhiy Storchaka in bpo-43833(1).)

   * Starting in this release, there will be a concerted effort to begin
     cleaning up old import semantics that were kept for Python 2.7
     compatibility.  Specifically, ‘find_loader()’/‘find_module()’
     (superseded by *note find_spec(): a6a.), *note load_module(): a6b.
     (superseded by *note exec_module(): a6c.), ‘module_repr()’ (which
     the import system takes care of for you), the ‘__package__’
     attribute (superseded by ‘__spec__.parent’), the ‘__loader__’
     attribute (superseded by ‘__spec__.loader’), and the ‘__cached__’
     attribute (superseded by ‘__spec__.cached’) will slowly be removed
     (as well as other classes and methods in *note importlib: 7b.).
     *note ImportWarning: 71f. and/or *note DeprecationWarning: 1a3.
     will be raised as appropriate to help identify code which needs
     updating during this transition.

   * The entire ‘distutils’ namespace is deprecated, to be removed in
     Python 3.12.  Refer to the *note module changes: 935. section for
     more information.

   * Non-integer arguments to *note random.randrange(): a6d. are
     deprecated.  The *note ValueError: 2ec. is deprecated in favor of a
     *note TypeError: 198.  (Contributed by Serhiy Storchaka and Raymond
     Hettinger in bpo-37319(2).)

   * The various ‘load_module()’ methods of *note importlib: 7b. have
     been documented as deprecated since Python 3.6, but will now also
     trigger a *note DeprecationWarning: 1a3.  Use *note exec_module():
     a6c. instead.  (Contributed by Brett Cannon in bpo-26131(3).)

   * ‘zimport.zipimporter.load_module()’ has been deprecated in
     preference for *note exec_module(): 339.  (Contributed by Brett
     Cannon in bpo-26131(4).)

   * The use of *note load_module(): a6b. by the import system now
     triggers an *note ImportWarning: 71f. as *note exec_module(): a6c.
     is preferred.  (Contributed by Brett Cannon in bpo-26131(5).)

   * The use of ‘importlib.abc.MetaPathFinder.find_module()’ and
     ‘importlib.abc.PathEntryFinder.find_module()’ by the import system
     now trigger an *note ImportWarning: 71f. as *note
     importlib.abc.MetaPathFinder.find_spec(): a6a. and *note
     importlib.abc.PathEntryFinder.find_spec(): a6e. are preferred,
     respectively.  You can use *note importlib.util.spec_from_loader():
     a6f. to help in porting.  (Contributed by Brett Cannon in
     bpo-42134(6).)

   * The use of ‘importlib.abc.PathEntryFinder.find_loader()’ by the
     import system now triggers an *note ImportWarning: 71f. as *note
     importlib.abc.PathEntryFinder.find_spec(): a6e. is preferred.  You
     can use *note importlib.util.spec_from_loader(): a6f. to help in
     porting.  (Contributed by Brett Cannon in bpo-43672(7).)

   * The various implementations of
     ‘importlib.abc.MetaPathFinder.find_module()’ (
     ‘importlib.machinery.BuiltinImporter.find_module()’,
     ‘importlib.machinery.FrozenImporter.find_module()’,
     ‘importlib.machinery.WindowsRegistryFinder.find_module()’,
     ‘importlib.machinery.PathFinder.find_module()’,
     ‘importlib.abc.MetaPathFinder.find_module()’ ),
     ‘importlib.abc.PathEntryFinder.find_module()’ (
     ‘importlib.machinery.FileFinder.find_module()’ ), and
     ‘importlib.abc.PathEntryFinder.find_loader()’ (
     ‘importlib.machinery.FileFinder.find_loader()’ ) now raise *note
     DeprecationWarning: 1a3. and are slated for removal in Python 3.12
     (previously they were documented as deprecated in Python 3.4).
     (Contributed by Brett Cannon in bpo-42135(8).)

   * ‘importlib.abc.Finder’ is deprecated (including its sole method,
     ‘find_module()’).  Both *note importlib.abc.MetaPathFinder: a70.
     and *note importlib.abc.PathEntryFinder: a71. no longer inherit
     from the class.  Users should inherit from one of these two classes
     as appropriate instead.  (Contributed by Brett Cannon in
     bpo-42135(9).)

   * The deprecations of ‘imp’, ‘importlib.find_loader()’,
     ‘importlib.util.set_package_wrapper()’,
     ‘importlib.util.set_loader_wrapper()’,
     ‘importlib.util.module_for_loader()’, ‘pkgutil.ImpImporter’, and
     ‘pkgutil.ImpLoader’ have all been updated to list Python 3.12 as
     the slated version of removal (they began raising *note
     DeprecationWarning: 1a3. in previous versions of Python).
     (Contributed by Brett Cannon in bpo-43720(10).)

   * The import system now uses the ‘__spec__’ attribute on modules
     before falling back on ‘module_repr()’ for a module’s ‘__repr__()’
     method.  Removal of the use of ‘module_repr()’ is scheduled for
     Python 3.12.  (Contributed by Brett Cannon in bpo-42137(11).)

   * ‘importlib.abc.Loader.module_repr()’,
     ‘importlib.machinery.FrozenLoader.module_repr()’, and
     ‘importlib.machinery.BuiltinLoader.module_repr()’ are deprecated
     and slated for removal in Python 3.12.  (Contributed by Brett
     Cannon in bpo-42136(12).)

   * ‘sqlite3.OptimizedUnicode’ has been undocumented and obsolete since
     Python 3.3, when it was made an alias to *note str: 169.  It is now
     deprecated, scheduled for removal in Python 3.12.  (Contributed by
     Erlend E. Aasland in bpo-42264(13).)

   * The undocumented built-in function ‘sqlite3.enable_shared_cache’ is
     now deprecated, scheduled for removal in Python 3.12.  Its use is
     strongly discouraged by the SQLite3 documentation.  See the SQLite3
     docs(14) for more details.  If a shared cache must be used, open
     the database in URI mode using the ‘cache=shared’ query parameter.
     (Contributed by Erlend E. Aasland in bpo-24464(15).)

   * The following ‘threading’ methods are now deprecated:

        * ‘threading.currentThread’ => *note threading.current_thread():
          35e.

        * ‘threading.activeCount’ => *note threading.active_count():
          35f.

        * ‘threading.Condition.notifyAll’ => *note
          threading.Condition.notify_all(): 359.

        * ‘threading.Event.isSet’ => *note threading.Event.is_set():
          35a.

        * ‘threading.Thread.setName’ => *note threading.Thread.name:
          2a0.

        * ‘threading.thread.getName’ => *note threading.Thread.name:
          2a0.

        * ‘threading.Thread.isDaemon’ => *note threading.Thread.daemon:
          35c.

        * ‘threading.Thread.setDaemon’ => *note threading.Thread.daemon:
          35c.

     (Contributed by Jelle Zijlstra in gh-87889(16).)

   * ‘pathlib.Path.link_to()’ is deprecated and slated for removal in
     Python 3.12.  Use *note pathlib.Path.hardlink_to(): a24. instead.
     (Contributed by Barney Gale in bpo-39950(17).)

   * ‘cgi.log()’ is deprecated and slated for removal in Python 3.12.
     (Contributed by Inada Naoki in bpo-41139(18).)

   * The following *note ssl: d5. features have been deprecated since
     Python 3.6, Python 3.7, or OpenSSL 1.1.0 and will be removed in
     3.11:

        * ‘OP_NO_SSLv2’, ‘OP_NO_SSLv3’, ‘OP_NO_TLSv1’, ‘OP_NO_TLSv1_1’,
          ‘OP_NO_TLSv1_2’, and ‘OP_NO_TLSv1_3’ are replaced by *note
          minimum_version: a72. and *note maximum_version: a73.

        * ‘PROTOCOL_SSLv2’, ‘PROTOCOL_SSLv3’, ‘PROTOCOL_SSLv23’,
          ‘PROTOCOL_TLSv1’, ‘PROTOCOL_TLSv1_1’, ‘PROTOCOL_TLSv1_2’, and
          ‘PROTOCOL_TLS’ are deprecated in favor of *note
          PROTOCOL_TLS_CLIENT: a74. and *note PROTOCOL_TLS_SERVER: a75.

        * ‘wrap_socket()’ is replaced by *note
          ssl.SSLContext.wrap_socket(): 749.

        * ‘match_hostname()’

        * ‘RAND_pseudo_bytes()’, ‘RAND_egd()’

        * NPN features like *note ssl.SSLSocket.selected_npn_protocol():
          a76. and *note ssl.SSLContext.set_npn_protocols(): 358. are
          replaced by ALPN.

   * The threading debug (‘PYTHONTHREADDEBUG’ environment variable) is
     deprecated in Python 3.10 and will be removed in Python 3.12.  This
     feature requires a *note debug build of Python: 50a.  (Contributed
     by Victor Stinner in bpo-44584(19).)

   * Importing from the ‘typing.io’ and ‘typing.re’ submodules will now
     emit *note DeprecationWarning: 1a3.  These submodules will be
     removed in a future version of Python.  Anything belonging to these
     submodules should be imported directly from *note typing: 10a.
     instead.  (Contributed by Sebastian Rittau in bpo-38291(20).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43833

   (2) https://bugs.python.org/issue?@action=redirect&bpo=37319

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26131

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26131

   (5) https://bugs.python.org/issue?@action=redirect&bpo=26131

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42134

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43672

   (8) https://bugs.python.org/issue?@action=redirect&bpo=42135

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42135

   (10) https://bugs.python.org/issue?@action=redirect&bpo=43720

   (11) https://bugs.python.org/issue?@action=redirect&bpo=42137

   (12) https://bugs.python.org/issue?@action=redirect&bpo=42136

   (13) https://bugs.python.org/issue?@action=redirect&bpo=42264

   (14) https://sqlite.org/c3ref/enable_shared_cache.html

   (15) https://bugs.python.org/issue?@action=redirect&bpo=24464

   (16) https://github.com/python/cpython/issues/87889

   (17) https://bugs.python.org/issue?@action=redirect&bpo=39950

   (18) https://bugs.python.org/issue?@action=redirect&bpo=41139

   (19) https://bugs.python.org/issue?@action=redirect&bpo=44584

   (20) https://bugs.python.org/issue?@action=redirect&bpo=38291


File: python.info,  Node: Removed<4>,  Next: Porting to Python 3 10,  Prev: Deprecated<4>,  Up: What’s New In Python 3 10

1.5.9 Removed
-------------

   * Removed special methods ‘__int__’, ‘__float__’, ‘__floordiv__’,
     ‘__mod__’, ‘__divmod__’, ‘__rfloordiv__’, ‘__rmod__’ and
     ‘__rdivmod__’ of the *note complex: 197. class.  They always raised
     a *note TypeError: 198.  (Contributed by Serhiy Storchaka in
     bpo-41974(1).)

   * The ‘ParserBase.error()’ method from the private and undocumented
     ‘_markupbase’ module has been removed.  *note
     html.parser.HTMLParser: a79. is the only subclass of ‘ParserBase’
     and its ‘error()’ implementation was already removed in Python 3.5.
     (Contributed by Berker Peksag in bpo-31844(2).)

   * Removed the ‘unicodedata.ucnhash_CAPI’ attribute which was an
     internal PyCapsule object.  The related private
     ‘_PyUnicode_Name_CAPI’ structure was moved to the internal C API.
     (Contributed by Victor Stinner in bpo-42157(3).)

   * Removed the ‘parser’ module, which was deprecated in 3.9 due to the
     switch to the new PEG parser, as well as all the C source and
     header files that were only being used by the old parser, including
     ‘node.h’, ‘parser.h’, ‘graminit.h’ and ‘grammar.h’.

   * Removed the Public C API functions
     ‘PyParser_SimpleParseStringFlags’,
     ‘PyParser_SimpleParseStringFlagsFilename’,
     ‘PyParser_SimpleParseFileFlags’ and ‘PyNode_Compile’ that were
     deprecated in 3.9 due to the switch to the new PEG parser.

   * Removed the ‘formatter’ module, which was deprecated in Python 3.4.
     It is somewhat obsolete, little used, and not tested.  It was
     originally scheduled to be removed in Python 3.6, but such removals
     were delayed until after Python 2.7 EOL. Existing users should copy
     whatever classes they use into their code.  (Contributed by Donghee
     Na and Terry J. Reedy in bpo-42299(4).)

   * Removed the ‘PyModule_GetWarningsModule()’ function that was
     useless now due to the ‘_warnings’ module was converted to a
     builtin module in 2.6.  (Contributed by Hai Shi in bpo-42599(5).)

   * Remove deprecated aliases to *note Collections Abstract Base
     Classes: a7a. from the *note collections: 1e. module.  (Contributed
     by Victor Stinner in bpo-37324(6).)

   * The ‘loop’ parameter has been removed from most of *note asyncio:
     b.“s *note high-level API: a7b. following deprecation in Python
     3.8.  The motivation behind this change is multifold:

       1. This simplifies the high-level API.

       2. The functions in the high-level API have been implicitly
          getting the current thread’s running event loop since Python
          3.7.  There isn’t a need to pass the event loop to the API in
          most normal use cases.

       3. Event loop passing is error-prone especially when dealing with
          loops running in different threads.

     Note that the low-level API will still accept ‘loop’.  See *note
     Changes in the Python API: a7c. for examples of how to replace
     existing code.

     (Contributed by Yurii Karabas, Andrew Svetlov, Yury Selivanov and
     Kyle Stanley in bpo-42392(7).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41974

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31844

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42157

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42299

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42599

   (6) https://bugs.python.org/issue?@action=redirect&bpo=37324

   (7) https://bugs.python.org/issue?@action=redirect&bpo=42392


File: python.info,  Node: Porting to Python 3 10,  Next: CPython bytecode changes<3>,  Prev: Removed<4>,  Up: What’s New In Python 3 10

1.5.10 Porting to Python 3.10
-----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code.

* Menu:

* Changes in the Python syntax::
* Changes in the Python API: Changes in the Python API<3>.
* Changes in the C API: Changes in the C API<3>.


File: python.info,  Node: Changes in the Python syntax,  Next: Changes in the Python API<3>,  Up: Porting to Python 3 10

1.5.10.1 Changes in the Python syntax
.....................................

   * Deprecation warning is now emitted when compiling previously valid
     syntax if the numeric literal is immediately followed by a keyword
     (like in ‘0in x’).  In future releases it will be changed to syntax
     warning, and finally to a syntax error.  To get rid of the warning
     and make the code compatible with future releases just add a space
     between the numeric literal and the following keyword.
     (Contributed by Serhiy Storchaka in bpo-43833(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43833


File: python.info,  Node: Changes in the Python API<3>,  Next: Changes in the C API<3>,  Prev: Changes in the Python syntax,  Up: Porting to Python 3 10

1.5.10.2 Changes in the Python API
..................................

   * The 'etype' parameters of the *note format_exception(): a4f, *note
     format_exception_only(): a50, and *note print_exception(): a51.
     functions in the *note traceback: 104. module have been renamed to
     'exc'.  (Contributed by Zackery Spytz and Matthias Bussonnier in
     bpo-26389(1).)

   * *note atexit: d.: At Python exit, if a callback registered with
     *note atexit.register(): a80. fails, its exception is now logged.
     Previously, only some exceptions were logged, and the last
     exception was always silently ignored.  (Contributed by Victor
     Stinner in bpo-42639(2).)

   * *note collections.abc.Callable: 9ed. generic now flattens type
     parameters, similar to what *note typing.Callable: 9ca. currently
     does.  This means that ‘collections.abc.Callable[[int, str], str]’
     will have ‘__args__’ of ‘(int, str, str)’; previously this was
     ‘([int, str], str)’.  Code which accesses the arguments via *note
     typing.get_args(): 2ac. or ‘__args__’ need to account for this
     change.  Furthermore, *note TypeError: 198. may be raised for
     invalid forms of parameterizing *note collections.abc.Callable:
     9ed. which may have passed silently in Python 3.9.  (Contributed by
     Ken Jin in bpo-42195(3).)

   * *note socket.htons(): a81. and *note socket.ntohs(): a82. now raise
     *note OverflowError: a83. instead of *note DeprecationWarning: 1a3.
     if the given parameter will not fit in a 16-bit unsigned integer.
     (Contributed by Erlend E. Aasland in bpo-42393(4).)

   * The ‘loop’ parameter has been removed from most of *note asyncio:
     b.“s *note high-level API: a7b. following deprecation in Python
     3.8.

     A coroutine that currently looks like this:

          async def foo(loop):
              await asyncio.sleep(1, loop=loop)

     Should be replaced with this:

          async def foo():
              await asyncio.sleep(1)

     If ‘foo()’ was specifically designed 'not' to run in the current
     thread’s running event loop (e.g.  running in another thread’s
     event loop), consider using *note
     asyncio.run_coroutine_threadsafe(): a84. instead.

     (Contributed by Yurii Karabas, Andrew Svetlov, Yury Selivanov and
     Kyle Stanley in bpo-42392(5).)

   * The *note types.FunctionType: a85. constructor now inherits the
     current builtins if the 'globals' dictionary has no
     ‘"__builtins__"’ key, rather than using ‘{"None": None}’ as
     builtins: same behavior as *note eval(): 4a4. and *note exec():
     4a3. functions.  Defining a function with ‘def function(...): ...’
     in Python is not affected, globals cannot be overridden with this
     syntax: it also inherits the current builtins.  (Contributed by
     Victor Stinner in bpo-42990(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26389

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42639

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42195

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42393

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42392

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42990


File: python.info,  Node: Changes in the C API<3>,  Prev: Changes in the Python API<3>,  Up: Porting to Python 3 10

1.5.10.3 Changes in the C API
.............................

   * The C API functions ‘PyParser_SimpleParseStringFlags’,
     ‘PyParser_SimpleParseStringFlagsFilename’,
     ‘PyParser_SimpleParseFileFlags’, ‘PyNode_Compile’ and the type used
     by these functions, ‘struct _node’, were removed due to the switch
     to the new PEG parser.

     Source should be now be compiled directly to a code object using,
     for example, *note Py_CompileString(): a87.  The resulting code
     object can then be evaluated using, for example, *note
     PyEval_EvalCode(): a88.

     Specifically:

        * A call to ‘PyParser_SimpleParseStringFlags’ followed by
          ‘PyNode_Compile’ can be replaced by calling *note
          Py_CompileString(): a87.

        * There is no direct replacement for
          ‘PyParser_SimpleParseFileFlags’.  To compile code from a ‘FILE
          *’ argument, you will need to read the file in C and pass the
          resulting buffer to *note Py_CompileString(): a87.

        * To compile a file given a ‘char *’ filename, explicitly open
          the file, read it and compile the result.  One way to do this
          is using the *note io: 83. module with *note
          PyImport_ImportModule(): 3dc, *note PyObject_CallMethod():
          640, *note PyBytes_AsString(): a89. and *note
          Py_CompileString(): a87, as sketched below.  (Declarations and
          error handling are omitted.)

               io_module = Import_ImportModule("io");
               fileobject = PyObject_CallMethod(io_module, "open", "ss", filename, "rb");
               source_bytes_object = PyObject_CallMethod(fileobject, "read", "");
               result = PyObject_CallMethod(fileobject, "close", "");
               source_buf = PyBytes_AsString(source_bytes_object);
               code = Py_CompileString(source_buf, filename, Py_file_input);

        * For ‘FrameObject’ objects, the *note f_lasti: a8a. member now
          represents a wordcode offset instead of a simple offset into
          the bytecode string.  This means that this number needs to be
          multiplied by 2 to be used with APIs that expect a byte offset
          instead (like *note PyCode_Addr2Line(): a8b. for example).
          Notice as well that the ‘f_lasti’ member of ‘FrameObject’
          objects is not considered stable: please use *note
          PyFrame_GetLineNumber(): 98f. instead.


File: python.info,  Node: CPython bytecode changes<3>,  Next: Build Changes<3>,  Prev: Porting to Python 3 10,  Up: What’s New In Python 3 10

1.5.11 CPython bytecode changes
-------------------------------

   * The ‘MAKE_FUNCTION’ instruction now accepts either a dict or a
     tuple of strings as the function’s annotations.  (Contributed by
     Yurii Karabas and Inada Naoki in bpo-42202(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42202


File: python.info,  Node: Build Changes<3>,  Next: C API Changes<3>,  Prev: CPython bytecode changes<3>,  Up: What’s New In Python 3 10

1.5.12 Build Changes
--------------------

   * PEP 644(1): Python now requires OpenSSL 1.1.1 or newer.  OpenSSL
     1.0.2 is no longer supported.  (Contributed by Christian Heimes in
     bpo-43669(2).)

   * The C99 functions ‘snprintf()’ and ‘vsnprintf()’ are now required
     to build Python.  (Contributed by Victor Stinner in bpo-36020(3).)

   * *note sqlite3: d4. requires SQLite 3.7.15 or higher.  (Contributed
     by Sergey Fedoseev and Erlend E. Aasland in bpo-40744(4) and
     bpo-40810(5).)

   * The *note atexit: d. module must now always be built as a built-in
     module.  (Contributed by Victor Stinner in bpo-42639(6).)

   * Add *note -disable-test-modules: a8e. option to the ‘configure’
     script: don’t build nor install test modules.  (Contributed by
     Xavier de Gaye, Thomas Petazzoni and Peixing Xin in bpo-27640(7).)

   * Add *note -with-wheel-pkg-dir=PATH option: a8f. to the
     ‘./configure’ script.  If specified, the *note ensurepip: 59.
     module looks for ‘setuptools’ and ‘pip’ wheel packages in this
     directory: if both are present, these wheel packages are used
     instead of ensurepip bundled wheel packages.

     Some Linux distribution packaging policies recommend against
     bundling dependencies.  For example, Fedora installs wheel packages
     in the ‘/usr/share/python-wheels/’ directory and don’t install the
     ‘ensurepip._bundled’ package.

     (Contributed by Victor Stinner in bpo-42856(8).)

   * Add a new *note configure -without-static-libpython option: a90. to
     not build the ‘libpythonMAJOR.MINOR.a’ static library and not
     install the ‘python.o’ object file.

     (Contributed by Victor Stinner in bpo-43103(9).)

   * The ‘configure’ script now uses the ‘pkg-config’ utility, if
     available, to detect the location of Tcl/Tk headers and libraries.
     As before, those locations can be explicitly specified with the
     ‘--with-tcltk-includes’ and ‘--with-tcltk-libs’ configuration
     options.  (Contributed by Manolis Stamatogiannakis in
     bpo-42603(10).)

   * Add *note -with-openssl-rpath: a91. option to ‘configure’ script.
     The option simplifies building Python with a custom OpenSSL
     installation, e.g.  ‘./configure --with-openssl=/path/to/openssl
     --with-openssl-rpath=auto’.  (Contributed by Christian Heimes in
     bpo-43466(11).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0644/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43669

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36020

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40744

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40810

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42639

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27640

   (8) https://bugs.python.org/issue?@action=redirect&bpo=42856

   (9) https://bugs.python.org/issue?@action=redirect&bpo=43103

   (10) https://bugs.python.org/issue?@action=redirect&bpo=42603

   (11) https://bugs.python.org/issue?@action=redirect&bpo=43466


File: python.info,  Node: C API Changes<3>,  Next: Notable security feature in 3 10 7,  Prev: Build Changes<3>,  Up: What’s New In Python 3 10

1.5.13 C API Changes
--------------------

* Menu:

* PEP 652; Maintaining the Stable ABI: PEP 652 Maintaining the Stable ABI.
* New Features: New Features<6>.
* Porting to Python 3.10: Porting to Python 3 10<2>.
* Deprecated: Deprecated<5>.
* Removed: Removed<5>.


File: python.info,  Node: PEP 652 Maintaining the Stable ABI,  Next: New Features<6>,  Up: C API Changes<3>

1.5.13.1 PEP 652: Maintaining the Stable ABI
............................................

The Stable ABI (Application Binary Interface) for extension modules or
embedding Python is now explicitly defined.  *note C API Stability: 776.
describes C API and ABI stability guarantees along with best practices
for using the Stable ABI.

(Contributed by Petr Viktorin in PEP 652(1) and bpo-43795(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0652/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43795


File: python.info,  Node: New Features<6>,  Next: Porting to Python 3 10<2>,  Prev: PEP 652 Maintaining the Stable ABI,  Up: C API Changes<3>

1.5.13.2 New Features
.....................

   * The result of *note PyNumber_Index(): a95. now always has exact
     type *note int: 19b.  Previously, the result could have been an
     instance of a subclass of ‘int’.  (Contributed by Serhiy Storchaka
     in bpo-40792(1).)

   * Add a new *note orig_argv: a96. member to the *note PyConfig: 3f7.
     structure: the list of the original command line arguments passed
     to the Python executable.  (Contributed by Victor Stinner in
     bpo-23427(2).)

   * The *note PyDateTime_DATE_GET_TZINFO(): a97. and *note
     PyDateTime_TIME_GET_TZINFO(): a98. macros have been added for
     accessing the ‘tzinfo’ attributes of *note datetime.datetime: 4e3.
     and *note datetime.time: 1fb. objects.  (Contributed by Zackery
     Spytz in bpo-30155(3).)

   * Add a *note PyCodec_Unregister(): a99. function to unregister a
     codec search function.  (Contributed by Hai Shi in bpo-41842(4).)

   * The *note PyIter_Send(): a9a. function was added to allow sending
     value into iterator without raising ‘StopIteration’ exception.
     (Contributed by Vladimir Matveev in bpo-41756(5).)

   * Add *note PyUnicode_AsUTF8AndSize(): a9b. to the limited C API.
     (Contributed by Alex Gaynor in bpo-41784(6).)

   * Add *note PyModule_AddObjectRef(): 60a. function: similar to *note
     PyModule_AddObject(): 60b. but don’t steal a reference to the value
     on success.  (Contributed by Victor Stinner in bpo-1635741(7).)

   * Add *note Py_NewRef(): a9c. and *note Py_XNewRef(): a9d. functions
     to increment the reference count of an object and return the
     object.  (Contributed by Victor Stinner in bpo-42262(8).)

   * The *note PyType_FromSpecWithBases(): 79f. and *note
     PyType_FromModuleAndSpec(): 774. functions now accept a single
     class as the 'bases' argument.  (Contributed by Serhiy Storchaka in
     bpo-42423(9).)

   * The *note PyType_FromModuleAndSpec(): 774. function now accepts
     NULL ‘tp_doc’ slot.  (Contributed by Hai Shi in bpo-41832(10).)

   * The *note PyType_GetSlot(): a9e. function can accept *note static
     types: 984.  (Contributed by Hai Shi and Petr Viktorin in
     bpo-41073(11).)

   * Add a new *note PySet_CheckExact(): a9f. function to the C-API to
     check if an object is an instance of *note set: 184. but not an
     instance of a subtype.  (Contributed by Pablo Galindo in
     bpo-43277(12).)

   * Add *note PyErr_SetInterruptEx(): aa0. which allows passing a
     signal number to simulate.  (Contributed by Antoine Pitrou in
     bpo-43356(13).)

   * The limited C API is now supported if *note Python is built in
     debug mode: 50a. (if the ‘Py_DEBUG’ macro is defined).  In the
     limited C API, the *note Py_INCREF(): 790. and *note Py_DECREF():
     791. functions are now implemented as opaque function calls, rather
     than accessing directly the *note PyObject.ob_refcnt: aa1. member,
     if Python is built in debug mode and the ‘Py_LIMITED_API’ macro
     targets Python 3.10 or newer.  It became possible to support the
     limited C API in debug mode because the *note PyObject: 5df.
     structure is the same in release and debug mode since Python 3.8
     (see bpo-36465(14)).

     The limited C API is still not supported in the *note
     -with-trace-refs: 636. special build (‘Py_TRACE_REFS’ macro).
     (Contributed by Victor Stinner in bpo-43688(15).)

   * Add the *note Py_Is(x, y): aa2. function to test if the 'x' object
     is the 'y' object, the same as ‘x is y’ in Python.  Add also the
     *note Py_IsNone(): aa3, *note Py_IsTrue(): aa4, *note Py_IsFalse():
     aa5. functions to test if an object is, respectively, the ‘None’
     singleton, the ‘True’ singleton or the ‘False’ singleton.
     (Contributed by Victor Stinner in bpo-43753(16).)

   * Add new functions to control the garbage collector from C code:
     *note PyGC_Enable(): aa6, *note PyGC_Disable(): aa7, *note
     PyGC_IsEnabled(): aa8.  These functions allow to activate,
     deactivate and query the state of the garbage collector from C code
     without having to import the *note gc: 64. module.

   * Add a new *note Py_TPFLAGS_DISALLOW_INSTANTIATION: 7a3. type flag
     to disallow creating type instances.  (Contributed by Victor
     Stinner in bpo-43916(17).)

   * Add a new *note Py_TPFLAGS_IMMUTABLETYPE: 3cf. type flag for
     creating immutable type objects: type attributes cannot be set nor
     deleted.  (Contributed by Victor Stinner and Erlend E. Aasland in
     bpo-43908(18).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40792

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23427

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30155

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41842

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41756

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41784

   (7) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (8) https://bugs.python.org/issue?@action=redirect&bpo=42262

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42423

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41832

   (11) https://bugs.python.org/issue?@action=redirect&bpo=41073

   (12) https://bugs.python.org/issue?@action=redirect&bpo=43277

   (13) https://bugs.python.org/issue?@action=redirect&bpo=43356

   (14) https://bugs.python.org/issue?@action=redirect&bpo=36465

   (15) https://bugs.python.org/issue?@action=redirect&bpo=43688

   (16) https://bugs.python.org/issue?@action=redirect&bpo=43753

   (17) https://bugs.python.org/issue?@action=redirect&bpo=43916

   (18) https://bugs.python.org/issue?@action=redirect&bpo=43908


File: python.info,  Node: Porting to Python 3 10<2>,  Next: Deprecated<5>,  Prev: New Features<6>,  Up: C API Changes<3>

1.5.13.3 Porting to Python 3.10
...............................

   * The ‘PY_SSIZE_T_CLEAN’ macro must now be defined to use *note
     PyArg_ParseTuple(): 3c1. and *note Py_BuildValue(): 3c2. formats
     which use ‘#’: ‘es#’, ‘et#’, ‘s#’, ‘u#’, ‘y#’, ‘z#’, ‘U#’ and ‘Z#’.
     See *note Parsing arguments and building values: 3d5. and PEP
     353(1).  (Contributed by Victor Stinner in bpo-40943(2).)

   * Since *note Py_REFCNT(): 2cf. is changed to the inline static
     function, ‘Py_REFCNT(obj) = new_refcnt’ must be replaced with
     ‘Py_SET_REFCNT(obj, new_refcnt)’: see *note Py_SET_REFCNT(): aaa.
     (available since Python 3.9).  For backward compatibility, this
     macro can be used:

          #if PY_VERSION_HEX < 0x030900A4
          #  define Py_SET_REFCNT(obj, refcnt) ((Py_REFCNT(obj) = (refcnt)), (void)0)
          #endif

     (Contributed by Victor Stinner in bpo-39573(3).)

   * Calling *note PyDict_GetItem(): 628. without *note GIL: 164. held
     had been allowed for historical reason.  It is no longer allowed.
     (Contributed by Victor Stinner in bpo-40839(4).)

   * ‘PyUnicode_FromUnicode(NULL, size)’ and
     ‘PyUnicode_FromStringAndSize(NULL, size)’ raise
     ‘DeprecationWarning’ now.  Use *note PyUnicode_New(): aab. to
     allocate Unicode object without initial data.  (Contributed by
     Inada Naoki in bpo-36346(5).)

   * The private ‘_PyUnicode_Name_CAPI’ structure of the PyCapsule API
     ‘unicodedata.ucnhash_CAPI’ has been moved to the internal C API.
     (Contributed by Victor Stinner in bpo-42157(6).)

   * *note Py_GetPath(): 3e3, *note Py_GetPrefix(): 3e5, *note
     Py_GetExecPrefix(): 3e9, *note Py_GetProgramFullPath(): 3ec, *note
     Py_GetPythonHome(): 3ef. and *note Py_GetProgramName(): 3ee.
     functions now return ‘NULL’ if called before *note Py_Initialize():
     460. (before Python is initialized).  Use the new *note Python
     Initialization Configuration: 646. API to get the *note Python Path
     Configuration: aac.  (Contributed by Victor Stinner in
     bpo-42260(7).)

   * *note PyList_SET_ITEM(): 62f, *note PyTuple_SET_ITEM(): 62e. and
     *note PyCell_SET(): aad. macros can no longer be used as l-value or
     r-value.  For example, ‘x = PyList_SET_ITEM(a, b, c)’ and
     ‘PyList_SET_ITEM(a, b, c) = x’ now fail with a compiler error.  It
     prevents bugs like ‘if (PyList_SET_ITEM (a, b, c) < 0) ...’ test.
     (Contributed by Zackery Spytz and Victor Stinner in bpo-30459(8).)

   * The non-limited API files ‘odictobject.h’, ‘parser_interface.h’,
     ‘picklebufobject.h’, ‘pyarena.h’, ‘pyctype.h’, ‘pydebug.h’,
     ‘pyfpe.h’, and ‘pytime.h’ have been moved to the ‘Include/cpython’
     directory.  These files must not be included directly, as they are
     already included in ‘Python.h’; see *note Include Files: 988.  If
     they have been included directly, consider including ‘Python.h’
     instead.  (Contributed by Nicholas Sim in bpo-35134(9).)

   * Use the *note Py_TPFLAGS_IMMUTABLETYPE: 3cf. type flag to create
     immutable type objects.  Do not rely on *note Py_TPFLAGS_HEAPTYPE:
     aae. to decide if a type object is mutable or not; check if *note
     Py_TPFLAGS_IMMUTABLETYPE: 3cf. is set instead.  (Contributed by
     Victor Stinner and Erlend E. Aasland in bpo-43908(10).)

   * The undocumented function ‘Py_FrozenMain’ has been removed from the
     limited API. The function is mainly useful for custom builds of
     Python.  (Contributed by Petr Viktorin in bpo-26241(11).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0353/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40943

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40839

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36346

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42157

   (7) https://bugs.python.org/issue?@action=redirect&bpo=42260

   (8) https://bugs.python.org/issue?@action=redirect&bpo=30459

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35134

   (10) https://bugs.python.org/issue?@action=redirect&bpo=43908

   (11) https://bugs.python.org/issue?@action=redirect&bpo=26241


File: python.info,  Node: Deprecated<5>,  Next: Removed<5>,  Prev: Porting to Python 3 10<2>,  Up: C API Changes<3>

1.5.13.4 Deprecated
...................

   * The ‘PyUnicode_InternImmortal()’ function is now deprecated and
     will be removed in Python 3.12: use *note
     PyUnicode_InternInPlace(): ab0. instead.  (Contributed by Victor
     Stinner in bpo-41692(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41692


File: python.info,  Node: Removed<5>,  Prev: Deprecated<5>,  Up: C API Changes<3>

1.5.13.5 Removed
................

   * Removed ‘Py_UNICODE_str*’ functions manipulating ‘Py_UNICODE*’
     strings.  (Contributed by Inada Naoki in bpo-41123(1).)

        * ‘Py_UNICODE_strlen’: use *note PyUnicode_GetLength(): ab2. or
          *note PyUnicode_GET_LENGTH: ab3.

        * ‘Py_UNICODE_strcat’: use *note PyUnicode_CopyCharacters():
          ab4. or *note PyUnicode_FromFormat(): 62b.

        * ‘Py_UNICODE_strcpy’, ‘Py_UNICODE_strncpy’: use *note
          PyUnicode_CopyCharacters(): ab4. or *note
          PyUnicode_Substring(): ab5.

        * ‘Py_UNICODE_strcmp’: use *note PyUnicode_Compare(): ab6.

        * ‘Py_UNICODE_strncmp’: use *note PyUnicode_Tailmatch(): ab7.

        * ‘Py_UNICODE_strchr’, ‘Py_UNICODE_strrchr’: use *note
          PyUnicode_FindChar(): ab8.

   * Removed ‘PyUnicode_GetMax()’.  Please migrate to new ( PEP 393(2))
     APIs.  (Contributed by Inada Naoki in bpo-41103(3).)

   * Removed ‘PyLong_FromUnicode()’.  Please migrate to *note
     PyLong_FromUnicodeObject(): ab9.  (Contributed by Inada Naoki in
     bpo-41103(4).)

   * Removed ‘PyUnicode_AsUnicodeCopy()’.  Please use *note
     PyUnicode_AsUCS4Copy(): aba. or *note PyUnicode_AsWideCharString():
     abb. (Contributed by Inada Naoki in bpo-41103(5).)

   * Removed ‘_Py_CheckRecursionLimit’ variable: it has been replaced by
     ‘ceval.recursion_limit’ of the *note PyInterpreterState: abc.
     structure.  (Contributed by Victor Stinner in bpo-41834(6).)

   * Removed undocumented macros ‘Py_ALLOW_RECURSION’ and
     ‘Py_END_ALLOW_RECURSION’ and the ‘recursion_critical’ field of the
     *note PyInterpreterState: abc. structure.  (Contributed by Serhiy
     Storchaka in bpo-41936(7).)

   * Removed the undocumented ‘PyOS_InitInterrupts()’ function.
     Initializing Python already implicitly installs signal handlers:
     see *note PyConfig.install_signal_handlers: abd.  (Contributed by
     Victor Stinner in bpo-41713(8).)

   * Remove the ‘PyAST_Validate()’ function.  It is no longer possible
     to build a AST object (‘mod_ty’ type) with the public C API. The
     function was already excluded from the limited C API ( PEP 384(9)).
     (Contributed by Victor Stinner in bpo-43244(10).)

   * Remove the ‘symtable.h’ header file and the undocumented functions:

        * ‘PyST_GetScope()’

        * ‘PySymtable_Build()’

        * ‘PySymtable_BuildObject()’

        * ‘PySymtable_Free()’

        * ‘Py_SymtableString()’

        * ‘Py_SymtableStringObject()’

     The ‘Py_SymtableString()’ function was part the stable ABI by
     mistake but it could not be used, because the ‘symtable.h’ header
     file was excluded from the limited C API.

     Use Python *note symtable: de. module instead.  (Contributed by
     Victor Stinner in bpo-43244(11).)

   * Remove *note PyOS_ReadlineFunctionPointer(): 7a6. from the limited
     C API headers and from ‘python3.dll’, the library that provides the
     stable ABI on Windows.  Since the function takes a ‘FILE*’
     argument, its ABI stability cannot be guaranteed.  (Contributed by
     Petr Viktorin in bpo-43868(12).)

   * Remove ‘ast.h’, ‘asdl.h’, and ‘Python-ast.h’ header files.  These
     functions were undocumented and excluded from the limited C API.
     Most names defined by these header files were not prefixed by ‘Py’
     and so could create names conflicts.  For example, ‘Python-ast.h’
     defined a ‘Yield’ macro which was conflict with the ‘Yield’ name
     used by the Windows ‘<winbase.h>’ header.  Use the Python *note
     ast: 9. module instead.  (Contributed by Victor Stinner in
     bpo-43244(13).)

   * Remove the compiler and parser functions using ‘struct _mod’ type,
     because the public AST C API was removed:

        * ‘PyAST_Compile()’

        * ‘PyAST_CompileEx()’

        * ‘PyAST_CompileObject()’

        * ‘PyFuture_FromAST()’

        * ‘PyFuture_FromASTObject()’

        * ‘PyParser_ASTFromFile()’

        * ‘PyParser_ASTFromFileObject()’

        * ‘PyParser_ASTFromFilename()’

        * ‘PyParser_ASTFromString()’

        * ‘PyParser_ASTFromStringObject()’

     These functions were undocumented and excluded from the limited C
     API. (Contributed by Victor Stinner in bpo-43244(14).)

   * Remove the ‘pyarena.h’ header file with functions:

        * ‘PyArena_New()’

        * ‘PyArena_Free()’

        * ‘PyArena_Malloc()’

        * ‘PyArena_AddPyObject()’

     These functions were undocumented, excluded from the limited C API,
     and were only used internally by the compiler.  (Contributed by
     Victor Stinner in bpo-43244(15).)

   * The ‘PyThreadState.use_tracing’ member has been removed to optimize
     Python.  (Contributed by Mark Shannon in bpo-43760(16).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41123

   (2) https://peps.python.org/pep-0393/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41103

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41103

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41103

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41834

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41936

   (8) https://bugs.python.org/issue?@action=redirect&bpo=41713

   (9) https://peps.python.org/pep-0384/

   (10) https://bugs.python.org/issue?@action=redirect&bpo=43244

   (11) https://bugs.python.org/issue?@action=redirect&bpo=43244

   (12) https://bugs.python.org/issue?@action=redirect&bpo=43868

   (13) https://bugs.python.org/issue?@action=redirect&bpo=43244

   (14) https://bugs.python.org/issue?@action=redirect&bpo=43244

   (15) https://bugs.python.org/issue?@action=redirect&bpo=43244

   (16) https://bugs.python.org/issue?@action=redirect&bpo=43760


File: python.info,  Node: Notable security feature in 3 10 7,  Next: Notable security feature in 3 10 8,  Prev: C API Changes<3>,  Up: What’s New In Python 3 10

1.5.14 Notable security feature in 3.10.7
-----------------------------------------

Converting between *note int: 19b. and *note str: 169. in bases other
than 2 (binary), 4, 8 (octal), 16 (hexadecimal), or 32 such as base 10
(decimal) now raises a *note ValueError: 2ec. if the number of digits in
string form is above a limit to avoid potential denial of service
attacks due to the algorithmic complexity.  This is a mitigation for CVE
2020-10735(1).  This limit can be configured or disabled by environment
variable, command line flag, or *note sys: df. APIs.  See the *note
integer string conversion length limitation: 80c. documentation.  The
default limit is 4300 digits in string form.

   ---------- Footnotes ----------

   (1) https://www.cve.org/CVERecord?id=CVE-2020-10735


File: python.info,  Node: Notable security feature in 3 10 8,  Next: Notable changes in 3 10 12,  Prev: Notable security feature in 3 10 7,  Up: What’s New In Python 3 10

1.5.15 Notable security feature in 3.10.8
-----------------------------------------

The deprecated ‘mailcap’ module now refuses to inject unsafe text
(filenames, MIME types, parameters) into shell commands.  Instead of
using such text, it will warn and act as if a match was not found (or
for test commands, as if the test failed).  (Contributed by Petr
Viktorin in gh-98966(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98966


File: python.info,  Node: Notable changes in 3 10 12,  Prev: Notable security feature in 3 10 8,  Up: What’s New In Python 3 10

1.5.16 Notable changes in 3.10.12
---------------------------------

* Menu:

* tarfile: tarfile<3>.


File: python.info,  Node: tarfile<3>,  Up: Notable changes in 3 10 12

1.5.16.1 tarfile
................

   * The extraction methods in *note tarfile: e4, and *note
     shutil.unpack_archive(): 697, have a new a 'filter' argument that
     allows limiting tar features than may be surprising or dangerous,
     such as creating files outside the destination directory.  See
     *note Extraction filters: 698. for details.  In Python 3.12, use
     without the 'filter' argument will show a *note DeprecationWarning:
     1a3.  In Python 3.14, the default will switch to ‘'data'’.
     (Contributed by Petr Viktorin in PEP 706(1).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0706/


File: python.info,  Node: What’s New In Python 3 9,  Next: What’s New In Python 3 8,  Prev: What’s New In Python 3 10,  Up: Novità in Python

1.6 What’s New In Python 3.9
============================


Editor: Łukasz Langa

This article explains the new features in Python 3.9, compared to 3.8.
Python 3.9 was released on October 5, 2020.  For full details, see the
*note changelog: 142.

Vedi anche
..........

PEP 596(1) - Python 3.9 Release Schedule

* Menu:

* Summary – Release highlights: Summary – Release highlights<4>.
* You should check for DeprecationWarning in your code::
* New Features: New Features<7>.
* Other Language Changes: Other Language Changes<4>.
* New Modules: New Modules<4>.
* Improved Modules: Improved Modules<4>.
* Optimizations: Optimizations<5>.
* Deprecated: Deprecated<6>.
* Removed: Removed<6>.
* Porting to Python 3.9: Porting to Python 3 9.
* Build Changes: Build Changes<4>.
* C API Changes: C API Changes<4>.
* Notable changes in Python 3.9.1: Notable changes in Python 3 9 1.
* Notable changes in Python 3.9.2: Notable changes in Python 3 9 2.
* Notable changes in Python 3.9.3: Notable changes in Python 3 9 3.
* Notable changes in Python 3.9.5: Notable changes in Python 3 9 5.
* Notable security feature in 3.9.14: Notable security feature in 3 9 14.
* Notable changes in 3.9.17: Notable changes in 3 9 17.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0596/


File: python.info,  Node: Summary – Release highlights<4>,  Next: You should check for DeprecationWarning in your code,  Up: What’s New In Python 3 9

1.6.1 Summary – Release highlights
----------------------------------

New syntax features:

   * PEP 584(1), union operators added to ‘dict’;

   * PEP 585(2), type hinting generics in standard collections;

   * PEP 614(3), relaxed grammar restrictions on decorators.

New built-in features:

   * PEP 616(4), string methods to remove prefixes and suffixes.

New features in the standard library:

   * PEP 593(5), flexible function and variable annotations;

   * *note os.pidfd_open(): 6a5. added that allows process management
     without races and signals.

Interpreter improvements:

   * PEP 573(6), fast access to module state from methods of C extension
     types;

   * PEP 617(7), CPython now uses a new parser based on PEG;

   * a number of Python builtins (range, tuple, set, frozenset, list,
     dict) are now sped up using PEP 590(8) vectorcall;

   * garbage collection does not block on resurrected objects;

   * a number of Python modules (‘_abc’, ‘audioop’, ‘_bz2’, ‘_codecs’,
     ‘_contextvars’, ‘_crypt’, ‘_functools’, ‘_json’, ‘_locale’, *note
     math: 92, *note operator: a3, *note resource: c1, *note time: f4,
     ‘_weakref’) now use multiphase initialization as defined by PEP
     489;

   * a number of standard library modules (‘audioop’, *note ast: 9,
     *note grp: 6a, ‘_hashlib’, *note pwd: b7, ‘_posixsubprocess’, *note
     random: bd, *note select: c6, *note struct: db, *note termios: e7,
     *note zlib: 139.) are now using the stable ABI defined by PEP 384.

New library modules:

   * PEP 615(9), the IANA Time Zone Database is now present in the
     standard library in the *note zoneinfo: 13a. module;

   * an implementation of a topological sort of a graph is now provided
     in the new *note graphlib: 69. module.

Release process changes:

   * PEP 602(10), CPython adopts an annual release cycle.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0584/

   (2) https://peps.python.org/pep-0585/

   (3) https://peps.python.org/pep-0614/

   (4) https://peps.python.org/pep-0616/

   (5) https://peps.python.org/pep-0593/

   (6) https://peps.python.org/pep-0573/

   (7) https://peps.python.org/pep-0617/

   (8) https://peps.python.org/pep-0590/

   (9) https://peps.python.org/pep-0615/

   (10) https://peps.python.org/pep-0602/


File: python.info,  Node: You should check for DeprecationWarning in your code,  Next: New Features<7>,  Prev: Summary – Release highlights<4>,  Up: What’s New In Python 3 9

1.6.2 You should check for DeprecationWarning in your code
----------------------------------------------------------

When Python 2.7 was still supported, a lot of functionality in Python 3
was kept for backward compatibility with Python 2.7.  With the end of
Python 2 support, these backward compatibility layers have been removed,
or will be removed soon.  Most of them emitted a *note
DeprecationWarning: 1a3. warning for several years.  For example, using
‘collections.Mapping’ instead of ‘collections.abc.Mapping’ emits a *note
DeprecationWarning: 1a3. since Python 3.3, released in 2012.

Test your application with the *note -W: ac7. ‘default’ command-line
option to see *note DeprecationWarning: 1a3. and *note
PendingDeprecationWarning: ac8, or even with *note -W: ac7. ‘error’ to
treat them as errors.  *note Warnings Filter: 1b1. can be used to ignore
warnings from third-party code.

Python 3.9 is the last version providing those Python 2 backward
compatibility layers, to give more time to Python projects maintainers
to organize the removal of the Python 2 support and add support for
Python 3.9.

Aliases to *note Abstract Base Classes: a7a. in the *note collections:
1e. module, like ‘collections.Mapping’ alias to *note
collections.abc.Mapping: ac9, are kept for one last release for backward
compatibility.  They will be removed from Python 3.10.

More generally, try to run your tests in the *note Python Development
Mode: 509. which helps to prepare your code to make it compatible with
the next Python version.

Note: a number of pre-existing deprecations were removed in this version
of Python as well.  Consult the *note Removed: aca. section.


File: python.info,  Node: New Features<7>,  Next: Other Language Changes<4>,  Prev: You should check for DeprecationWarning in your code,  Up: What’s New In Python 3 9

1.6.3 New Features
------------------

* Menu:

* Dictionary Merge & Update Operators::
* New String Methods to Remove Prefixes and Suffixes::
* Type Hinting Generics in Standard Collections::
* New Parser::


File: python.info,  Node: Dictionary Merge & Update Operators,  Next: New String Methods to Remove Prefixes and Suffixes,  Up: New Features<7>

1.6.3.1 Dictionary Merge & Update Operators
...........................................

Merge (‘|’) and update (‘|=’) operators have been added to the built-in
*note dict: 183. class.  Those complement the existing ‘dict.update’ and
‘{**d1, **d2}’ methods of merging dictionaries.

Example:

     >>> x = {"key1": "value1 from x", "key2": "value2 from x"}
     >>> y = {"key2": "value2 from y", "key3": "value3 from y"}
     >>> x | y
     {'key1': 'value1 from x', 'key2': 'value2 from y', 'key3': 'value3 from y'}
     >>> y | x
     {'key2': 'value2 from x', 'key3': 'value3 from y', 'key1': 'value1 from x'}

See PEP 584(1) for a full description.  (Contributed by Brandt Bucher in
bpo-36144(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0584/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36144


File: python.info,  Node: New String Methods to Remove Prefixes and Suffixes,  Next: Type Hinting Generics in Standard Collections,  Prev: Dictionary Merge & Update Operators,  Up: New Features<7>

1.6.3.2 New String Methods to Remove Prefixes and Suffixes
..........................................................

*note str.removeprefix(prefix): ace. and *note str.removesuffix(suffix):
acf. have been added to easily remove an unneeded prefix or a suffix
from a string.  Corresponding ‘bytes’, ‘bytearray’, and
‘collections.UserString’ methods have also been added.  See PEP 616(1)
for a full description.  (Contributed by Dennis Sweeney in
bpo-39939(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0616/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39939


File: python.info,  Node: Type Hinting Generics in Standard Collections,  Next: New Parser,  Prev: New String Methods to Remove Prefixes and Suffixes,  Up: New Features<7>

1.6.3.3 Type Hinting Generics in Standard Collections
.....................................................

In type annotations you can now use built-in collection types such as
‘list’ and ‘dict’ as generic types instead of importing the
corresponding capitalized types (e.g.  ‘List’ or ‘Dict’) from ‘typing’.
Some other types in the standard library are also now generic, for
example ‘queue.Queue’.

Example:

     def greet_all(names: list[str]) -> None:
         for name in names:
             print("Hello", name)

See PEP 585(1) for more details.  (Contributed by Guido van Rossum,
Ethan Smith, and Batuhan Taşkaya in bpo-39481(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0585/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39481


File: python.info,  Node: New Parser,  Prev: Type Hinting Generics in Standard Collections,  Up: New Features<7>

1.6.3.4 New Parser
..................

Python 3.9 uses a new parser, based on PEG(1) instead of LL(1)(2).  The
new parser’s performance is roughly comparable to that of the old
parser, but the PEG formalism is more flexible than LL(1) when it comes
to designing new language features.  We’ll start using this flexibility
in Python 3.10 and later.

The *note ast: 9. module uses the new parser and produces the same AST
as the old parser.

In Python 3.10, the old parser will be deleted and so will all
functionality that depends on it (primarily the ‘parser’ module, which
has long been deprecated).  In Python 3.9 'only', you can switch back to
the LL(1) parser using a command line switch (‘-X oldparser’) or an
environment variable (‘PYTHONOLDPARSER=1’).

See PEP 617(3) for more details.  (Contributed by Guido van Rossum,
Pablo Galindo and Lysandros Nikolaou in bpo-40334(4).)

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Parsing_expression_grammar

   (2) https://en.wikipedia.org/wiki/LL_parser

   (3) https://peps.python.org/pep-0617/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40334


File: python.info,  Node: Other Language Changes<4>,  Next: New Modules<4>,  Prev: New Features<7>,  Up: What’s New In Python 3 9

1.6.4 Other Language Changes
----------------------------

   * *note __import__(): ad3. now raises *note ImportError: 65b. instead
     of *note ValueError: 2ec, which used to occur when a relative
     import went past its top-level package.  (Contributed by Ngalim
     Siregar in bpo-37444(1).)

   * Python now gets the absolute path of the script filename specified
     on the command line (ex: ‘python3 script.py’): the ‘__file__’
     attribute of the *note __main__: 1. module became an absolute path,
     rather than a relative path.  These paths now remain valid after
     the current directory is changed by *note os.chdir(): 822.  As a
     side effect, the traceback also displays the absolute path for
     *note __main__: 1. module frames in this case.  (Contributed by
     Victor Stinner in bpo-20443(2).)

   * In the *note Python Development Mode: 509. and in *note debug
     build: 50a, the 'encoding' and 'errors' arguments are now checked
     for string encoding and decoding operations.  Examples: *note
     open(): 316, *note str.encode(): ad4. and *note bytes.decode():
     ad5.

     By default, for best performance, the 'errors' argument is only
     checked at the first encoding/decoding error and the 'encoding'
     argument is sometimes ignored for empty strings.  (Contributed by
     Victor Stinner in bpo-37388(3).)

   * ‘"".replace("", s, n)’ now returns ‘s’ instead of an empty string
     for all non-zero ‘n’.  It is now consistent with ‘"".replace("",
     s)’.  There are similar changes for *note bytes: 192. and *note
     bytearray: 344. objects.  (Contributed by Serhiy Storchaka in
     bpo-28029(4).)

   * Any valid expression can now be used as a *note decorator: 93b.
     Previously, the grammar was much more restrictive.  See PEP 614(5)
     for details.  (Contributed by Brandt Bucher in bpo-39702(6).)

   * Improved help for the *note typing: 10a. module.  Docstrings are
     now shown for all special forms and special generic aliases (like
     ‘Union’ and ‘List’).  Using *note help(): ad6. with generic alias
     like ‘List[int]’ will show the help for the correspondent concrete
     type (‘list’ in this case).  (Contributed by Serhiy Storchaka in
     bpo-40257(7).)

   * Parallel running of *note aclose(): ad7. / *note asend(): ad8. /
     *note athrow(): 71e. is now prohibited, and ‘ag_running’ now
     reflects the actual running status of the async generator.
     (Contributed by Yury Selivanov in bpo-30773(8).)

   * Unexpected errors in calling the ‘__iter__’ method are no longer
     masked by ‘TypeError’ in the *note in: 34b. operator and functions
     *note contains(): ad9, *note indexOf(): ada. and *note countOf():
     adb. of the *note operator: a3. module.  (Contributed by Serhiy
     Storchaka in bpo-40824(9).)

   * Unparenthesized lambda expressions can no longer be the expression
     part in an ‘if’ clause in comprehensions and generator expressions.
     See bpo-41848(10) and bpo-43755(11) for details.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37444

   (2) https://bugs.python.org/issue?@action=redirect&bpo=20443

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37388

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28029

   (5) https://peps.python.org/pep-0614/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39702

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40257

   (8) https://bugs.python.org/issue?@action=redirect&bpo=30773

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40824

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41848

   (11) https://bugs.python.org/issue?@action=redirect&bpo=43755


File: python.info,  Node: New Modules<4>,  Next: Improved Modules<4>,  Prev: Other Language Changes<4>,  Up: What’s New In Python 3 9

1.6.5 New Modules
-----------------

* Menu:

* zoneinfo::
* graphlib: graphlib<2>.


File: python.info,  Node: zoneinfo,  Next: graphlib<2>,  Up: New Modules<4>

1.6.5.1 zoneinfo
................

The *note zoneinfo: 13a. module brings support for the IANA time zone
database to the standard library.  It adds *note zoneinfo.ZoneInfo: ade,
a concrete *note datetime.tzinfo: 7f7. implementation backed by the
system’s time zone data.

Example:

     >>> from zoneinfo import ZoneInfo
     >>> from datetime import datetime, timedelta

     >>> # Daylight saving time
     >>> dt = datetime(2020, 10, 31, 12, tzinfo=ZoneInfo("America/Los_Angeles"))
     >>> print(dt)
     2020-10-31 12:00:00-07:00
     >>> dt.tzname()
     'PDT'

     >>> # Standard time
     >>> dt += timedelta(days=7)
     >>> print(dt)
     2020-11-07 12:00:00-08:00
     >>> print(dt.tzname())
     PST

As a fall-back source of data for platforms that don’t ship the IANA
database, the tzdata(1) module was released as a first-party package –
distributed via PyPI and maintained by the CPython core team.

Vedi anche
..........

PEP 615(2) – Support for the IANA Time Zone Database in the Standard Library

     PEP written and implemented by Paul Ganssle

   ---------- Footnotes ----------

   (1) https://pypi.org/project/tzdata/

   (2) https://peps.python.org/pep-0615/


File: python.info,  Node: graphlib<2>,  Prev: zoneinfo,  Up: New Modules<4>

1.6.5.2 graphlib
................

A new module, *note graphlib: 69, was added that contains the *note
graphlib.TopologicalSorter: ae0. class to offer functionality to perform
topological sorting of graphs.  (Contributed by Pablo Galindo, Tim
Peters and Larry Hastings in bpo-17005(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17005


File: python.info,  Node: Improved Modules<4>,  Next: Optimizations<5>,  Prev: New Modules<4>,  Up: What’s New In Python 3 9

1.6.6 Improved Modules
----------------------

* Menu:

* ast: ast<4>.
* asyncio: asyncio<8>.
* compileall: compileall<2>.
* concurrent.futures: concurrent futures<3>.
* curses: curses<3>.
* datetime: datetime<3>.
* distutils: distutils<3>.
* fcntl: fcntl<2>.
* ftplib: ftplib<2>.
* gc: gc<3>.
* hashlib: hashlib<4>.
* http: http<2>.
* IDLE and idlelib: IDLE and idlelib<3>.
* imaplib: imaplib<2>.
* importlib: importlib<3>.
* inspect: inspect<5>.
* ipaddress: ipaddress<2>.
* math: math<4>.
* multiprocessing: multiprocessing<3>.
* nntplib::
* os: os<6>.
* pathlib: pathlib<9>.
* pdb: pdb<5>.
* poplib::
* pprint: pprint<2>.
* pydoc: pydoc<2>.
* random: random<3>.
* signal::
* smtplib::
* socket: socket<4>.
* time: time<3>.
* sys: sys<6>.
* tracemalloc::
* typing: typing<7>.
* unicodedata: unicodedata<5>.
* venv: venv<3>.
* xml: xml<3>.


File: python.info,  Node: ast<4>,  Next: asyncio<8>,  Up: Improved Modules<4>

1.6.6.1 ast
...........

Added the 'indent' option to *note dump(): ae3. which allows it to
produce a multiline indented output.  (Contributed by Serhiy Storchaka
in bpo-37995(1).)

Added *note ast.unparse(): ae4. as a function in the *note ast: 9.
module that can be used to unparse an *note ast.AST: 4c4. object and
produce a string with code that would produce an equivalent *note
ast.AST: 4c4. object when parsed.  (Contributed by Pablo Galindo and
Batuhan Taskaya in bpo-38870(2).)

Added docstrings to AST nodes that contains the ASDL signature used to
construct that node.  (Contributed by Batuhan Taskaya in bpo-39638(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37995

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38870

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39638


File: python.info,  Node: asyncio<8>,  Next: compileall<2>,  Prev: ast<4>,  Up: Improved Modules<4>

1.6.6.2 asyncio
...............

Due to significant security concerns, the 'reuse_address' parameter of
*note asyncio.loop.create_datagram_endpoint(): 93d. is no longer
supported.  This is because of the behavior of the socket option
‘SO_REUSEADDR’ in UDP. For more details, see the documentation for
‘loop.create_datagram_endpoint()’.  (Contributed by Kyle Stanley,
Antoine Pitrou, and Yury Selivanov in bpo-37228(1).)

Added a new *note coroutine: 6ba. *note shutdown_default_executor():
ae6. that schedules a shutdown for the default executor that waits on
the *note ThreadPoolExecutor: 94a. to finish closing.  Also, *note
asyncio.run(): 2f3. has been updated to use the new *note coroutine:
6ba.  (Contributed by Kyle Stanley in bpo-34037(2).)

Added ‘asyncio.PidfdChildWatcher’, a Linux-specific child watcher
implementation that polls process file descriptors.  (bpo-38692(3))

Added a new *note coroutine: 6ba. *note asyncio.to_thread(): ae7.  It is
mainly used for running IO-bound functions in a separate thread to avoid
blocking the event loop, and essentially works as a high-level version
of *note run_in_executor(): ae8. that can directly take keyword
arguments.  (Contributed by Kyle Stanley and Yury Selivanov in
bpo-32309(4).)

When cancelling the task due to a timeout, *note asyncio.wait_for():
816. will now wait until the cancellation is complete also in the case
when 'timeout' is <= 0, like it does with positive timeouts.
(Contributed by Elvis Pranskevichus in bpo-32751(5).)

*note asyncio: b. now raises *note TypeError: 198. when calling
incompatible methods with an *note ssl.SSLSocket: ae9. socket.
(Contributed by Ido Michael in bpo-37404(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37228

   (2) https://bugs.python.org/issue?@action=redirect&bpo=34037

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38692

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32309

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32751

   (6) https://bugs.python.org/issue?@action=redirect&bpo=37404


File: python.info,  Node: compileall<2>,  Next: concurrent futures<3>,  Prev: asyncio<8>,  Up: Improved Modules<4>

1.6.6.3 compileall
..................

Added new possibility to use hardlinks for duplicated ‘.pyc’ files:
'hardlink_dupes' parameter and –hardlink-dupes command line option.
(Contributed by Lumír “Frenzy” Balhar in bpo-40495(1).)

Added new options for path manipulation in resulting ‘.pyc’ files:
'stripdir', 'prependdir', 'limit_sl_dest' parameters and -s, -p, -e
command line options.  Added the possibility to specify the option for
an optimization level multiple times.  (Contributed by Lumír “Frenzy”
Balhar in bpo-38112(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40495

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38112


File: python.info,  Node: concurrent futures<3>,  Next: curses<3>,  Prev: compileall<2>,  Up: Improved Modules<4>

1.6.6.4 concurrent.futures
..........................

Added a new 'cancel_futures' parameter to *note
concurrent.futures.Executor.shutdown(): aec. that cancels all pending
futures which have not started running, instead of waiting for them to
complete before shutting down the executor.  (Contributed by Kyle
Stanley in bpo-39349(1).)

Removed daemon threads from *note ThreadPoolExecutor: 94a. and *note
ProcessPoolExecutor: 1d6.  This improves compatibility with
subinterpreters and predictability in their shutdown processes.
(Contributed by Kyle Stanley in bpo-39812(2).)

Workers in *note ProcessPoolExecutor: 1d6. are now spawned on demand,
only when there are no available idle workers to reuse.  This optimizes
startup overhead and reduces the amount of lost CPU time to idle
workers.  (Contributed by Kyle Stanley in bpo-39207(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39349

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39812

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39207


File: python.info,  Node: curses<3>,  Next: datetime<3>,  Prev: concurrent futures<3>,  Up: Improved Modules<4>

1.6.6.5 curses
..............

Added *note curses.get_escdelay(): aee, *note curses.set_escdelay():
aef, *note curses.get_tabsize(): af0, and *note curses.set_tabsize():
af1. functions.  (Contributed by Anthony Sottile in bpo-38312(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38312


File: python.info,  Node: datetime<3>,  Next: distutils<3>,  Prev: curses<3>,  Up: Improved Modules<4>

1.6.6.6 datetime
................

The *note isocalendar(): af3. of *note datetime.date: 1fa. and *note
isocalendar(): af4. of *note datetime.datetime: 4e3. methods now returns
a *note namedtuple(): 4e1. instead of a *note tuple: 614.  (Contributed
by Donghee Na in bpo-24416(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24416


File: python.info,  Node: distutils<3>,  Next: fcntl<2>,  Prev: datetime<3>,  Up: Improved Modules<4>

1.6.6.7 distutils
.................

The ‘upload’ command now creates SHA2-256 and Blake2b-256 hash digests.
It skips MD5 on platforms that block MD5 digest.  (Contributed by
Christian Heimes in bpo-40698(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40698


File: python.info,  Node: fcntl<2>,  Next: ftplib<2>,  Prev: distutils<3>,  Up: Improved Modules<4>

1.6.6.8 fcntl
.............

Added constants ‘fcntl.F_OFD_GETLK’, ‘fcntl.F_OFD_SETLK’ and
‘fcntl.F_OFD_SETLKW’.  (Contributed by Donghee Na in bpo-38602(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38602


File: python.info,  Node: ftplib<2>,  Next: gc<3>,  Prev: fcntl<2>,  Up: Improved Modules<4>

1.6.6.9 ftplib
..............

*note FTP: af8. and *note FTP_TLS: af9. now raise a *note ValueError:
2ec. if the given timeout for their constructor is zero to prevent the
creation of a non-blocking socket.  (Contributed by Donghee Na in
bpo-39259(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39259


File: python.info,  Node: gc<3>,  Next: hashlib<4>,  Prev: ftplib<2>,  Up: Improved Modules<4>

1.6.6.10 gc
...........

When the garbage collector makes a collection in which some objects
resurrect (they are reachable from outside the isolated cycles after the
finalizers have been executed), do not block the collection of all
objects that are still unreachable.  (Contributed by Pablo Galindo and
Tim Peters in bpo-38379(1).)

Added a new function *note gc.is_finalized(): afb. to check if an object
has been finalized by the garbage collector.  (Contributed by Pablo
Galindo in bpo-39322(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38379

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39322


File: python.info,  Node: hashlib<4>,  Next: http<2>,  Prev: gc<3>,  Up: Improved Modules<4>

1.6.6.11 hashlib
................

The *note hashlib: 6c. module can now use SHA3 hashes and SHAKE XOF from
OpenSSL when available.  (Contributed by Christian Heimes in
bpo-37630(1).)

Builtin hash modules can now be disabled with ‘./configure
--without-builtin-hashlib-hashes’ or selectively enabled with e.g.
‘./configure --with-builtin-hashlib-hashes=sha3,blake2’ to force use of
OpenSSL based implementation.  (Contributed by Christian Heimes in
bpo-40479(2))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37630

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40479


File: python.info,  Node: http<2>,  Next: IDLE and idlelib<3>,  Prev: hashlib<4>,  Up: Improved Modules<4>

1.6.6.12 http
.............

HTTP status codes ‘103 EARLY_HINTS’, ‘418 IM_A_TEAPOT’ and ‘425
TOO_EARLY’ are added to *note http.HTTPStatus: afe.  (Contributed by
Donghee Na in bpo-39509(1) and Ross Rhodes in bpo-39507(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39509

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39507


File: python.info,  Node: IDLE and idlelib<3>,  Next: imaplib<2>,  Prev: http<2>,  Up: Improved Modules<4>

1.6.6.13 IDLE and idlelib
.........................

Added option to toggle cursor blink off.  (Contributed by Zackery Spytz
in bpo-4603(1).)

Escape key now closes IDLE completion windows.  (Contributed by Johnny
Najera in bpo-38944(2).)

Added keywords to module name completion list.  (Contributed by Terry J.
Reedy in bpo-37765(3).)

New in 3.9 maintenance releases

Make IDLE invoke *note sys.excepthook(): a0e. (when started without
“-n”).  User hooks were previously ignored.  (Contributed by Ken Hilton
in bpo-43008(4).)

The changes above have been backported to 3.8 maintenance releases.

Rearrange the settings dialog.  Split the General tab into Windows and
Shell/Ed tabs.  Move help sources, which extend the Help menu, to the
Extensions tab.  Make space for new options and shorten the dialog.  The
latter makes the dialog better fit small screens.  (Contributed by Terry
Jan Reedy in bpo-40468(5).)  Move the indent space setting from the Font
tab to the new Windows tab.  (Contributed by Mark Roseman and Terry Jan
Reedy in bpo-33962(6).)

Apply syntax highlighting to ‘.pyi’ files.  (Contributed by Alex Waygood
and Terry Jan Reedy in bpo-45447(7).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4603

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38944

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37765

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43008

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40468

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33962

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45447


File: python.info,  Node: imaplib<2>,  Next: importlib<3>,  Prev: IDLE and idlelib<3>,  Up: Improved Modules<4>

1.6.6.14 imaplib
................

*note IMAP4: b01. and *note IMAP4_SSL: b02. now have an optional
'timeout' parameter for their constructors.  Also, the *note open():
b03. method now has an optional 'timeout' parameter with this change.
The overridden methods of *note IMAP4_SSL: b02. and *note IMAP4_stream:
b04. were applied to this change.  (Contributed by Donghee Na in
bpo-38615(1).)

*note imaplib.IMAP4.unselect(): b05. is added.  *note
imaplib.IMAP4.unselect(): b05. frees server’s resources associated with
the selected mailbox and returns the server to the authenticated state.
This command performs the same actions as *note imaplib.IMAP4.close():
b06, except that no messages are permanently removed from the currently
selected mailbox.  (Contributed by Donghee Na in bpo-40375(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38615

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40375


File: python.info,  Node: importlib<3>,  Next: inspect<5>,  Prev: imaplib<2>,  Up: Improved Modules<4>

1.6.6.15 importlib
..................

To improve consistency with import statements, *note
importlib.util.resolve_name(): b08. now raises *note ImportError: 65b.
instead of *note ValueError: 2ec. for invalid relative import attempts.
(Contributed by Ngalim Siregar in bpo-37444(1).)

Import loaders which publish immutable module objects can now publish
immutable packages in addition to individual modules.  (Contributed by
Dino Viehland in bpo-39336(2).)

Added *note importlib.resources.files(): 6b7. function with support for
subdirectories in package data, matching backport in
‘importlib_resources’ version 1.5.  (Contributed by Jason R. Coombs in
bpo-39791(3).)

Refreshed ‘importlib.metadata’ from ‘importlib_metadata’ version 1.6.1.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37444

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39336

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39791


File: python.info,  Node: inspect<5>,  Next: ipaddress<2>,  Prev: importlib<3>,  Up: Improved Modules<4>

1.6.6.16 inspect
................

*note inspect.BoundArguments.arguments: b0a. is changed from
‘OrderedDict’ to regular dict.  (Contributed by Inada Naoki in
bpo-36350(1) and bpo-39775(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36350

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39775


File: python.info,  Node: ipaddress<2>,  Next: math<4>,  Prev: inspect<5>,  Up: Improved Modules<4>

1.6.6.17 ipaddress
..................

*note ipaddress: 84. now supports IPv6 Scoped Addresses (IPv6 address
with suffix ‘%<scope_id>’).

Scoped IPv6 addresses can be parsed using *note ipaddress.IPv6Address:
50e.  If present, scope zone ID is available through the *note scope_id:
b0c. attribute.  (Contributed by Oleksandr Pavliuk in bpo-34788(1).)

Starting with Python 3.9.5 the *note ipaddress: 84. module no longer
accepts any leading zeros in IPv4 address strings.  (Contributed by
Christian Heimes in bpo-36384(2)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34788

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36384


File: python.info,  Node: math<4>,  Next: multiprocessing<3>,  Prev: ipaddress<2>,  Up: Improved Modules<4>

1.6.6.18 math
.............

Expanded the *note math.gcd(): b0e. function to handle multiple
arguments.  Formerly, it only supported two arguments.  (Contributed by
Serhiy Storchaka in bpo-39648(1).)

Added *note math.lcm(): b0f.: return the least common multiple of
specified arguments.  (Contributed by Mark Dickinson, Ananthakrishnan
and Serhiy Storchaka in bpo-39479(2) and bpo-39648(3).)

Added *note math.nextafter(): 6c1.: return the next floating-point value
after 'x' towards 'y'.  (Contributed by Victor Stinner in bpo-39288(4).)

Added *note math.ulp(): b10.: return the value of the least significant
bit of a float.  (Contributed by Victor Stinner in bpo-39310(5).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39648

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39479

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39648

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39288

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39310


File: python.info,  Node: multiprocessing<3>,  Next: nntplib,  Prev: math<4>,  Up: Improved Modules<4>

1.6.6.19 multiprocessing
........................

The *note multiprocessing.SimpleQueue: b12. class has a new *note
close(): b13. method to explicitly close the queue.  (Contributed by
Victor Stinner in bpo-30966(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30966


File: python.info,  Node: nntplib,  Next: os<6>,  Prev: multiprocessing<3>,  Up: Improved Modules<4>

1.6.6.20 nntplib
................

‘NNTP’ and ‘NNTP_SSL’ now raise a *note ValueError: 2ec. if the given
timeout for their constructor is zero to prevent the creation of a
non-blocking socket.  (Contributed by Donghee Na in bpo-39259(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39259


File: python.info,  Node: os<6>,  Next: pathlib<9>,  Prev: nntplib,  Up: Improved Modules<4>

1.6.6.21 os
...........

Added *note CLD_KILLED: b16. and *note CLD_STOPPED: b17. for ‘si_code’.
(Contributed by Donghee Na in bpo-38493(1).)

Exposed the Linux-specific *note os.pidfd_open(): 6a5. (bpo-38692(2))
and *note os.P_PIDFD: b18. (bpo-38713(3)) for process management with
file descriptors.

The *note os.unsetenv(): 25c. function is now also available on Windows.
(Contributed by Victor Stinner in bpo-39413(4).)

The *note os.putenv(): 25b. and *note os.unsetenv(): 25c. functions are
now always available.  (Contributed by Victor Stinner in bpo-39395(5).)

Added *note os.waitstatus_to_exitcode(): b19. function: convert a wait
status to an exit code.  (Contributed by Victor Stinner in
bpo-40094(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38493

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38692

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38713

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39413

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39395

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40094


File: python.info,  Node: pathlib<9>,  Next: pdb<5>,  Prev: os<6>,  Up: Improved Modules<4>

1.6.6.22 pathlib
................

Added *note pathlib.Path.readlink(): b1b. which acts similarly to *note
os.readlink(): b1c.  (Contributed by Girts Folkmanis in bpo-30618(1))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30618


File: python.info,  Node: pdb<5>,  Next: poplib,  Prev: pathlib<9>,  Up: Improved Modules<4>

1.6.6.23 pdb
............

On Windows now *note Pdb: 273. supports ‘~/.pdbrc’.  (Contributed by Tim
Hopper and Dan Lidral-Porter in bpo-20523(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20523


File: python.info,  Node: poplib,  Next: pprint<2>,  Prev: pdb<5>,  Up: Improved Modules<4>

1.6.6.24 poplib
...............

*note POP3: b1f. and *note POP3_SSL: b20. now raise a *note ValueError:
2ec. if the given timeout for their constructor is zero to prevent the
creation of a non-blocking socket.  (Contributed by Donghee Na in
bpo-39259(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39259


File: python.info,  Node: pprint<2>,  Next: pydoc<2>,  Prev: poplib,  Up: Improved Modules<4>

1.6.6.25 pprint
...............

*note pprint: b3. can now pretty-print *note types.SimpleNamespace: 4e6.
(Contributed by Carl Bordum Hansen in bpo-37376(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37376


File: python.info,  Node: pydoc<2>,  Next: random<3>,  Prev: pprint<2>,  Up: Improved Modules<4>

1.6.6.26 pydoc
..............

The documentation string is now shown not only for class, function,
method etc, but for any object that has its own *note __doc__: b23.
attribute.  (Contributed by Serhiy Storchaka in bpo-40257(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40257


File: python.info,  Node: random<3>,  Next: signal,  Prev: pydoc<2>,  Up: Improved Modules<4>

1.6.6.27 random
...............

Added a new *note random.Random.randbytes(): b25. method: generate
random bytes.  (Contributed by Victor Stinner in bpo-40286(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40286


File: python.info,  Node: signal,  Next: smtplib,  Prev: random<3>,  Up: Improved Modules<4>

1.6.6.28 signal
...............

Exposed the Linux-specific *note signal.pidfd_send_signal(): b27. for
sending to signals to a process using a file descriptor instead of a
pid.  (bpo-38712(1))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38712


File: python.info,  Node: smtplib,  Next: socket<4>,  Prev: signal,  Up: Improved Modules<4>

1.6.6.29 smtplib
................

*note SMTP: b29. and *note SMTP_SSL: b2a. now raise a *note ValueError:
2ec. if the given timeout for their constructor is zero to prevent the
creation of a non-blocking socket.  (Contributed by Donghee Na in
bpo-39259(1).)

*note LMTP: b2b. constructor now has an optional 'timeout' parameter.
(Contributed by Donghee Na in bpo-39329(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39259

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39329


File: python.info,  Node: socket<4>,  Next: time<3>,  Prev: smtplib,  Up: Improved Modules<4>

1.6.6.30 socket
...............

The *note socket: d1. module now exports the *note CAN_RAW_JOIN_FILTERS:
b2d. constant on Linux 4.1 and greater.  (Contributed by Stefan
Tatschner and Zackery Spytz in bpo-25780(1).)

The socket module now supports the *note CAN_J1939: b2e. protocol on
platforms that support it.  (Contributed by Karl Ding in bpo-40291(2).)

The socket module now has the *note socket.send_fds(): b2f. and *note
socket.recv_fds(): b30. functions.  (Contributed by Joannah Nanjekye,
Shinya Okano and Victor Stinner in bpo-28724(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25780

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40291

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28724


File: python.info,  Node: time<3>,  Next: sys<6>,  Prev: socket<4>,  Up: Improved Modules<4>

1.6.6.31 time
.............

On AIX, *note thread_time(): b32. is now implemented with
‘thread_cputime()’ which has nanosecond resolution, rather than
‘clock_gettime(CLOCK_THREAD_CPUTIME_ID)’ which has a resolution of 10
milliseconds.  (Contributed by Batuhan Taskaya in bpo-40192(1))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40192


File: python.info,  Node: sys<6>,  Next: tracemalloc,  Prev: time<3>,  Up: Improved Modules<4>

1.6.6.32 sys
............

Added a new *note sys.platlibdir: b34. attribute: name of the
platform-specific library directory.  It is used to build the path of
standard library and the paths of installed extension modules.  It is
equal to ‘"lib"’ on most platforms.  On Fedora and SuSE, it is equal to
‘"lib64"’ on 64-bit platforms.  (Contributed by Jan Matějek, Matěj Cepl,
Charalampos Stratakis and Victor Stinner in bpo-1294959(1).)

Previously, *note sys.stderr: b35. was block-buffered when
non-interactive.  Now ‘stderr’ defaults to always being line-buffered.
(Contributed by Jendrik Seipp in bpo-13601(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1294959

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13601


File: python.info,  Node: tracemalloc,  Next: typing<7>,  Prev: sys<6>,  Up: Improved Modules<4>

1.6.6.33 tracemalloc
....................

Added *note tracemalloc.reset_peak(): b37. to set the peak size of
traced memory blocks to the current size, to measure the peak of
specific pieces of code.  (Contributed by Huon Wilson in bpo-40630(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40630


File: python.info,  Node: typing<7>,  Next: unicodedata<5>,  Prev: tracemalloc,  Up: Improved Modules<4>

1.6.6.34 typing
...............

PEP 593(1) introduced an *note typing.Annotated: b39. type to decorate
existing types with context-specific metadata and new ‘include_extras’
parameter to *note typing.get_type_hints(): 8c1. to access the metadata
at runtime.  (Contributed by Till Varoquaux and Konstantin Kashin.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0593/


File: python.info,  Node: unicodedata<5>,  Next: venv<3>,  Prev: typing<7>,  Up: Improved Modules<4>

1.6.6.35 unicodedata
....................

The Unicode database has been updated to version 13.0.0.
(bpo-39926(1)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39926


File: python.info,  Node: venv<3>,  Next: xml<3>,  Prev: unicodedata<5>,  Up: Improved Modules<4>

1.6.6.36 venv
.............

The activation scripts provided by *note venv: 117. now all specify
their prompt customization consistently by always using the value
specified by ‘__VENV_PROMPT__’.  Previously some scripts unconditionally
used ‘__VENV_PROMPT__’, others only if it happened to be set (which was
the default case), and one used ‘__VENV_NAME__’ instead.  (Contributed
by Brett Cannon in bpo-37663(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37663


File: python.info,  Node: xml<3>,  Prev: venv<3>,  Up: Improved Modules<4>

1.6.6.37 xml
............

White space characters within attributes are now preserved when
serializing *note xml.etree.ElementTree: 12b. to XML file.  EOLNs are no
longer normalized to «n».  This is the result of discussion about how to
interpret section 2.11 of XML spec.  (Contributed by Mefistotelis in
bpo-39011(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39011


File: python.info,  Node: Optimizations<5>,  Next: Deprecated<6>,  Prev: Improved Modules<4>,  Up: What’s New In Python 3 9

1.6.7 Optimizations
-------------------

   * Optimized the idiom for assignment a temporary variable in
     comprehensions.  Now ‘for y in [expr]’ in comprehensions is as fast
     as a simple assignment ‘y = expr’.  For example:

          sums = [s for s in [0] for x in data for s in [s + x]]

     Unlike the ‘:=’ operator this idiom does not leak a variable to the
     outer scope.

     (Contributed by Serhiy Storchaka in bpo-32856(1).)

   * Optimized signal handling in multithreaded applications.  If a
     thread different than the main thread gets a signal, the bytecode
     evaluation loop is no longer interrupted at each bytecode
     instruction to check for pending signals which cannot be handled.
     Only the main thread of the main interpreter can handle signals.

     Previously, the bytecode evaluation loop was interrupted at each
     instruction until the main thread handles signals.  (Contributed by
     Victor Stinner in bpo-40010(2).)

   * Optimized the *note subprocess: dc. module on FreeBSD using
     ‘closefrom()’.  (Contributed by Ed Maste, Conrad Meyer, Kyle Evans,
     Kubilay Kocak and Victor Stinner in bpo-38061(3).)

   * *note PyLong_FromDouble(): b3e. is now up to 1.87x faster for
     values that fit into long.  (Contributed by Sergey Fedoseev in
     bpo-37986(4).)

   * A number of Python builtins (*note range: b3f, *note tuple: 614,
     *note set: 184, *note frozenset: 7f3, *note list: 24d, *note dict:
     183.) are now sped up by using PEP 590(5) vectorcall protocol.
     (Contributed by Donghee Na, Mark Shannon, Jeroen Demeyer and Petr
     Viktorin in bpo-37207(6).)

   * Optimized ‘set.difference_update()’ for the case when the other set
     is much larger than the base set.  (Suggested by Evgeny Kapun with
     code contributed by Michele Orrù in bpo-8425(7).)

   * Python’s small object allocator (‘obmalloc.c’) now allows (no more
     than) one empty arena to remain available for immediate reuse,
     without returning it to the OS. This prevents thrashing in simple
     loops where an arena could be created and destroyed anew on each
     iteration.  (Contributed by Tim Peters in bpo-37257(8).)

   * *note floor division: b40. of float operation now has a better
     performance.  Also the message of *note ZeroDivisionError: b41. for
     this operation is updated.  (Contributed by Donghee Na in
     bpo-39434(9).)

   * Decoding short ASCII strings with UTF-8 and ascii codecs is now
     about 15% faster.  (Contributed by Inada Naoki in bpo-37348(10).)

Here’s a summary of performance improvements from Python 3.4 through
Python 3.9:

     Python version                       3.4     3.5     3.6     3.7     3.8    3.9
     --------------                       ---     ---     ---     ---     ---    ---

     Variable and attribute read access:
         read_local                       7.1     7.1     5.4     5.1     3.9    3.9
         read_nonlocal                    7.1     8.1     5.8     5.4     4.4    4.5
         read_global                     15.5    19.0    14.3    13.6     7.6    7.8
         read_builtin                    21.1    21.6    18.5    19.0     7.5    7.8
         read_classvar_from_class        25.6    26.5    20.7    19.5    18.4   17.9
         read_classvar_from_instance     22.8    23.5    18.8    17.1    16.4   16.9
         read_instancevar                32.4    33.1    28.0    26.3    25.4   25.3
         read_instancevar_slots          27.8    31.3    20.8    20.8    20.2   20.5
         read_namedtuple                 73.8    57.5    45.0    46.8    18.4   18.7
         read_boundmethod                37.6    37.9    29.6    26.9    27.7   41.1

     Variable and attribute write access:
         write_local                      8.7     9.3     5.5     5.3     4.3    4.3
         write_nonlocal                  10.5    11.1     5.6     5.5     4.7    4.8
         write_global                    19.7    21.2    18.0    18.0    15.8   16.7
         write_classvar                  92.9    96.0   104.6   102.1    39.2   39.8
         write_instancevar               44.6    45.8    40.0    38.9    35.5   37.4
         write_instancevar_slots         35.6    36.1    27.3    26.6    25.7   25.8

     Data structure read access:
         read_list                       24.2    24.5    20.8    20.8    19.0   19.5
         read_deque                      24.7    25.5    20.2    20.6    19.8   20.2
         read_dict                       24.3    25.7    22.3    23.0    21.0   22.4
         read_strdict                    22.6    24.3    19.5    21.2    18.9   21.5

     Data structure write access:
         write_list                      27.1    28.5    22.5    21.6    20.0   20.0
         write_deque                     28.7    30.1    22.7    21.8    23.5   21.7
         write_dict                      31.4    33.3    29.3    29.2    24.7   25.4
         write_strdict                   28.4    29.9    27.5    25.2    23.1   24.5

     Stack (or queue) operations:
         list_append_pop                 93.4   112.7    75.4    74.2    50.8   50.6
         deque_append_pop                43.5    57.0    49.4    49.2    42.5   44.2
         deque_append_popleft            43.7    57.3    49.7    49.7    42.8   46.4

     Timing loop:
         loop_overhead                    0.5     0.6     0.4     0.3     0.3    0.3

These results were generated from the variable access benchmark script
at: ‘Tools/scripts/var_access_benchmark.py’.  The benchmark script
displays timings in nanoseconds.  The benchmarks were measured on an
Intel® Core™ i7-4960HQ processor(11) running the macOS 64-bit builds
found at python.org(12).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32856

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40010

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38061

   (4) https://bugs.python.org/issue?@action=redirect&bpo=37986

   (5) https://peps.python.org/pep-0590/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=37207

   (7) https://bugs.python.org/issue?@action=redirect&bpo=8425

   (8) https://bugs.python.org/issue?@action=redirect&bpo=37257

   (9) https://bugs.python.org/issue?@action=redirect&bpo=39434

   (10) https://bugs.python.org/issue?@action=redirect&bpo=37348

   (11) 
https://ark.intel.com/content/www/us/en/ark/products/76088/intel-core-i7-4960hq-processor-6m-cache-up-to-3-80-ghz.html

   (12) https://www.python.org/downloads/macos/


File: python.info,  Node: Deprecated<6>,  Next: Removed<6>,  Prev: Optimizations<5>,  Up: What’s New In Python 3 9

1.6.8 Deprecated
----------------

   * The distutils ‘bdist_msi’ command is now deprecated, use
     ‘bdist_wheel’ (wheel packages) instead.  (Contributed by Hugo van
     Kemenade in bpo-39586(1).)

   * Currently *note math.factorial(): b43. accepts *note float: 196.
     instances with non-negative integer values (like ‘5.0’).  It raises
     a *note ValueError: 2ec. for non-integral and negative floats.  It
     is now deprecated.  In future Python versions it will raise a *note
     TypeError: 198. for all floats.  (Contributed by Serhiy Storchaka
     in bpo-37315(2).)

   * The ‘parser’ and ‘symbol’ modules are deprecated and will be
     removed in future versions of Python.  For the majority of use
     cases, users can leverage the Abstract Syntax Tree (AST) generation
     and compilation stage, using the *note ast: 9. module.

   * The Public C API functions ‘PyParser_SimpleParseStringFlags()’,
     ‘PyParser_SimpleParseStringFlagsFilename()’,
     ‘PyParser_SimpleParseFileFlags()’ and ‘PyNode_Compile()’ are
     deprecated and will be removed in Python 3.10 together with the old
     parser.

   * Using *note NotImplemented: 1a2. in a boolean context has been
     deprecated, as it is almost exclusively the result of incorrect
     rich comparator implementations.  It will be made a *note
     TypeError: 198. in a future version of Python.  (Contributed by
     Josh Rosenberg in bpo-35712(3).)

   * The *note random: bd. module currently accepts any hashable type as
     a possible seed value.  Unfortunately, some of those types are not
     guaranteed to have a deterministic hash value.  After Python 3.9,
     the module will restrict its seeds to *note None: 886, *note int:
     19b, *note float: 196, *note str: 169, *note bytes: 192, and *note
     bytearray: 344.

   * Opening the *note GzipFile: 65c. file for writing without
     specifying the 'mode' argument is deprecated.  In future Python
     versions it will always be opened for reading by default.  Specify
     the 'mode' argument for opening it for writing and silencing a
     warning.  (Contributed by Serhiy Storchaka in bpo-28286(4).)

   * Deprecated the ‘split()’ method of ‘_tkinter.TkappType’ in favour
     of the ‘splitlist()’ method which has more consistent and
     predictable behavior.  (Contributed by Serhiy Storchaka in
     bpo-38371(5).)

   * The explicit passing of coroutine objects to *note asyncio.wait():
     6a8. has been deprecated and will be removed in version 3.11.
     (Contributed by Yury Selivanov and Kyle Stanley in bpo-34790(6).)

   * binhex4 and hexbin4 standards are now deprecated.  The ‘binhex’
     module and the following *note binascii: 11. functions are now
     deprecated:

        * ‘b2a_hqx()’, ‘a2b_hqx()’

        * ‘rlecode_hqx()’, ‘rledecode_hqx()’

     (Contributed by Victor Stinner in bpo-39353(7).)

   * *note ast: 9. classes ‘slice’, ‘Index’ and ‘ExtSlice’ are
     considered deprecated and will be removed in future Python
     versions.  ‘value’ itself should be used instead of ‘Index(value)’.
     ‘Tuple(slices, Load())’ should be used instead of
     ‘ExtSlice(slices)’.  (Contributed by Serhiy Storchaka in
     bpo-34822(8).)

   * *note ast: 9. classes ‘Suite’, ‘Param’, ‘AugLoad’ and ‘AugStore’
     are considered deprecated and will be removed in future Python
     versions.  They were not generated by the parser and not accepted
     by the code generator in Python 3.  (Contributed by Batuhan Taskaya
     in bpo-39639(9) and bpo-39969(10) and Serhiy Storchaka in
     bpo-39988(11).)

   * The ‘PyEval_InitThreads()’ and ‘PyEval_ThreadsInitialized()’
     functions are now deprecated and will be removed in Python 3.11.
     Calling ‘PyEval_InitThreads()’ now does nothing.  The *note GIL:
     164. is initialized by *note Py_Initialize(): 460. since Python
     3.7.  (Contributed by Victor Stinner in bpo-39877(12).)

   * Passing ‘None’ as the first argument to the *note shlex.split():
     75f. function has been deprecated.  (Contributed by Zackery Spytz
     in bpo-33262(13).)

   * ‘smtpd.MailmanProxy()’ is now deprecated as it is unusable without
     an external module, ‘mailman’.  (Contributed by Samuel Colvin in
     bpo-35800(14).)

   * The ‘lib2to3’ module now emits a *note PendingDeprecationWarning:
     ac8.  Python 3.9 switched to a PEG parser (see PEP 617(15)), and
     Python 3.10 may include new language syntax that is not parsable by
     lib2to3’s LL(1) parser.  The ‘lib2to3’ module may be removed from
     the standard library in a future Python version.  Consider
     third-party alternatives such as LibCST(16) or parso(17).
     (Contributed by Carl Meyer in bpo-40360(18).)

   * The 'random' parameter of *note random.shuffle(): 94f. has been
     deprecated.  (Contributed by Raymond Hettinger in bpo-40465(19))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39586

   (2) https://bugs.python.org/issue?@action=redirect&bpo=37315

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35712

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28286

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38371

   (6) https://bugs.python.org/issue?@action=redirect&bpo=34790

   (7) https://bugs.python.org/issue?@action=redirect&bpo=39353

   (8) https://bugs.python.org/issue?@action=redirect&bpo=34822

   (9) https://bugs.python.org/issue?@action=redirect&bpo=39639

   (10) https://bugs.python.org/issue?@action=redirect&bpo=39969

   (11) https://bugs.python.org/issue?@action=redirect&bpo=39988

   (12) https://bugs.python.org/issue?@action=redirect&bpo=39877

   (13) https://bugs.python.org/issue?@action=redirect&bpo=33262

   (14) https://bugs.python.org/issue?@action=redirect&bpo=35800

   (15) https://peps.python.org/pep-0617/

   (16) https://libcst.readthedocs.io/

   (17) https://parso.readthedocs.io/

   (18) https://bugs.python.org/issue?@action=redirect&bpo=40360

   (19) https://bugs.python.org/issue?@action=redirect&bpo=40465


File: python.info,  Node: Removed<6>,  Next: Porting to Python 3 9,  Prev: Deprecated<6>,  Up: What’s New In Python 3 9

1.6.9 Removed
-------------

   * The erroneous version at ‘unittest.mock.__version__’ has been
     removed.

   * ‘nntplib.NNTP’: ‘xpath()’ and ‘xgtitle()’ methods have been
     removed.  These methods are deprecated since Python 3.3.
     Generally, these extensions are not supported or not enabled by
     NNTP server administrators.  For ‘xgtitle()’, please use
     ‘nntplib.NNTP.descriptions()’ or ‘nntplib.NNTP.description()’
     instead.  (Contributed by Donghee Na in bpo-39366(1).)

   * *note array.array: 4bf.: ‘tostring()’ and ‘fromstring()’ methods
     have been removed.  They were aliases to ‘tobytes()’ and
     ‘frombytes()’, deprecated since Python 3.2.  (Contributed by Victor
     Stinner in bpo-38916(2).)

   * The undocumented ‘sys.callstats()’ function has been removed.
     Since Python 3.7, it was deprecated and always returned *note None:
     886.  It required a special build option ‘CALL_PROFILE’ which was
     already removed in Python 3.7.  (Contributed by Victor Stinner in
     bpo-37414(3).)

   * The ‘sys.getcheckinterval()’ and ‘sys.setcheckinterval()’ functions
     have been removed.  They were deprecated since Python 3.2.  Use
     *note sys.getswitchinterval(): b45. and *note
     sys.setswitchinterval(): b46. instead.  (Contributed by Victor
     Stinner in bpo-37392(4).)

   * The C function ‘PyImport_Cleanup()’ has been removed.  It was
     documented as: «Empty the module table.  For internal use only.»
     (Contributed by Victor Stinner in bpo-36710(5).)

   * ‘_dummy_thread’ and ‘dummy_threading’ modules have been removed.
     These modules were deprecated since Python 3.7 which requires
     threading support.  (Contributed by Victor Stinner in
     bpo-37312(6).)

   * ‘aifc.openfp()’ alias to ‘aifc.open()’, ‘sunau.openfp()’ alias to
     ‘sunau.open()’, and ‘wave.openfp()’ alias to *note wave.open():
     b47. have been removed.  They were deprecated since Python 3.7.
     (Contributed by Victor Stinner in bpo-37320(7).)

   * The ‘isAlive()’ method of *note threading.Thread: 176. has been
     removed.  It was deprecated since Python 3.8.  Use *note
     is_alive(): b48. instead.  (Contributed by Donghee Na in
     bpo-37804(8).)

   * Methods ‘getchildren()’ and ‘getiterator()’ of classes *note
     ElementTree: b49. and *note Element: 363. in the *note ElementTree:
     12b. module have been removed.  They were deprecated in Python 3.2.
     Use ‘iter(x)’ or ‘list(x)’ instead of ‘x.getchildren()’ and
     ‘x.iter()’ or ‘list(x.iter())’ instead of ‘x.getiterator()’.
     (Contributed by Serhiy Storchaka in bpo-36543(9).)

   * The old *note plistlib: b0. API has been removed, it was deprecated
     since Python 3.4.  Use the *note load(): b4a, *note loads(): b4b,
     *note dump(): b4c, and *note dumps(): b4d. functions.
     Additionally, the 'use_builtin_types' parameter was removed,
     standard *note bytes: 192. objects are always used instead.
     (Contributed by Jon Janzen in bpo-36409(10).)

   * The C function ‘PyGen_NeedsFinalizing’ has been removed.  It was
     not documented, tested, or used anywhere within CPython after the
     implementation of PEP 442(11).  Patch by Joannah Nanjekye.
     (Contributed by Joannah Nanjekye in bpo-15088(12))

   * ‘base64.encodestring()’ and ‘base64.decodestring()’, aliases
     deprecated since Python 3.1, have been removed: use *note
     base64.encodebytes(): b4e. and *note base64.decodebytes(): b4f.
     instead.  (Contributed by Victor Stinner in bpo-39351(13).)

   * ‘fractions.gcd()’ function has been removed, it was deprecated
     since Python 3.5 (bpo-22486(14)): use *note math.gcd(): b0e.
     instead.  (Contributed by Victor Stinner in bpo-39350(15).)

   * The 'buffering' parameter of *note bz2.BZ2File: a68. has been
     removed.  Since Python 3.0, it was ignored and using it emitted a
     *note DeprecationWarning: 1a3.  Pass an open file object to control
     how the file is opened.  (Contributed by Victor Stinner in
     bpo-39357(16).)

   * The 'encoding' parameter of *note json.loads(): b50. has been
     removed.  As of Python 3.1, it was deprecated and ignored; using it
     has emitted a *note DeprecationWarning: 1a3. since Python 3.8.
     (Contributed by Inada Naoki in bpo-39377(17))

   * ‘with (await asyncio.lock):’ and ‘with (yield from asyncio.lock):’
     statements are not longer supported, use ‘async with lock’ instead.
     The same is correct for ‘asyncio.Condition’ and
     ‘asyncio.Semaphore’.  (Contributed by Andrew Svetlov in
     bpo-34793(18).)

   * The ‘sys.getcounts()’ function, the ‘-X showalloccount’ command
     line option and the ‘show_alloc_count’ field of the C structure
     *note PyConfig: 3f7. have been removed.  They required a special
     Python build by defining ‘COUNT_ALLOCS’ macro.  (Contributed by
     Victor Stinner in bpo-39489(19).)

   * The ‘_field_types’ attribute of the *note typing.NamedTuple: 331.
     class has been removed.  It was deprecated since Python 3.8.  Use
     the ‘__annotations__’ attribute instead.  (Contributed by Serhiy
     Storchaka in bpo-40182(20).)

   * The ‘symtable.SymbolTable.has_exec()’ method has been removed.  It
     was deprecated since 2006, and only returning ‘False’ when it’s
     called.  (Contributed by Batuhan Taskaya in bpo-40208(21))

   * The ‘asyncio.Task.current_task()’ and ‘asyncio.Task.all_tasks()’
     have been removed.  They were deprecated since Python 3.7 and you
     can use *note asyncio.current_task(): 6a6. and *note
     asyncio.all_tasks(): b51. instead.  (Contributed by Rémi Lapeyre in
     bpo-40967(22))

   * The ‘unescape()’ method in the *note html.parser.HTMLParser: a79.
     class has been removed (it was deprecated since Python 3.4).  *note
     html.unescape(): b52. should be used for converting character
     references to the corresponding unicode characters.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39366

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38916

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37414

   (4) https://bugs.python.org/issue?@action=redirect&bpo=37392

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36710

   (6) https://bugs.python.org/issue?@action=redirect&bpo=37312

   (7) https://bugs.python.org/issue?@action=redirect&bpo=37320

   (8) https://bugs.python.org/issue?@action=redirect&bpo=37804

   (9) https://bugs.python.org/issue?@action=redirect&bpo=36543

   (10) https://bugs.python.org/issue?@action=redirect&bpo=36409

   (11) https://peps.python.org/pep-0442/

   (12) https://bugs.python.org/issue?@action=redirect&bpo=15088

   (13) https://bugs.python.org/issue?@action=redirect&bpo=39351

   (14) https://bugs.python.org/issue?@action=redirect&bpo=22486

   (15) https://bugs.python.org/issue?@action=redirect&bpo=39350

   (16) https://bugs.python.org/issue?@action=redirect&bpo=39357

   (17) https://bugs.python.org/issue?@action=redirect&bpo=39377

   (18) https://bugs.python.org/issue?@action=redirect&bpo=34793

   (19) https://bugs.python.org/issue?@action=redirect&bpo=39489

   (20) https://bugs.python.org/issue?@action=redirect&bpo=40182

   (21) https://bugs.python.org/issue?@action=redirect&bpo=40208

   (22) https://bugs.python.org/issue?@action=redirect&bpo=40967


File: python.info,  Node: Porting to Python 3 9,  Next: Build Changes<4>,  Prev: Removed<6>,  Up: What’s New In Python 3 9

1.6.10 Porting to Python 3.9
----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code.

* Menu:

* Changes in the Python API: Changes in the Python API<4>.
* Changes in the C API: Changes in the C API<4>.
* CPython bytecode changes: CPython bytecode changes<4>.


File: python.info,  Node: Changes in the Python API<4>,  Next: Changes in the C API<4>,  Up: Porting to Python 3 9

1.6.10.1 Changes in the Python API
..................................

   * *note __import__(): ad3. and *note importlib.util.resolve_name():
     b08. now raise *note ImportError: 65b. where it previously raised
     *note ValueError: 2ec.  Callers catching the specific exception
     type and supporting both Python 3.9 and earlier versions will need
     to catch both using ‘except (ImportError, ValueError):’.

   * The *note venv: 117. activation scripts no longer special-case when
     ‘__VENV_PROMPT__’ is set to ‘""’.

   * The *note select.epoll.unregister(): b55. method no longer ignores
     the *note EBADF: b56. error.  (Contributed by Victor Stinner in
     bpo-39239(1).)

   * The 'compresslevel' parameter of *note bz2.BZ2File: a68. became
     keyword-only, since the 'buffering' parameter has been removed.
     (Contributed by Victor Stinner in bpo-39357(2).)

   * Simplified AST for subscription.  Simple indices will be
     represented by their value, extended slices will be represented as
     tuples.  ‘Index(value)’ will return a ‘value’ itself,
     ‘ExtSlice(slices)’ will return ‘Tuple(slices, Load())’.
     (Contributed by Serhiy Storchaka in bpo-34822(3).)

   * The *note importlib: 7b. module now ignores the *note PYTHONCASEOK:
     b57. environment variable when the *note -E: b58. or *note -I: b59.
     command line options are being used.

   * The 'encoding' parameter has been added to the classes *note
     ftplib.FTP: af8. and *note ftplib.FTP_TLS: af9. as a keyword-only
     parameter, and the default encoding is changed from Latin-1 to
     UTF-8 to follow RFC 2640(4).

   * *note asyncio.loop.shutdown_default_executor(): ae6. has been added
     to *note AbstractEventLoop: b5a, meaning alternative event loops
     that inherit from it should have this method defined.  (Contributed
     by Kyle Stanley in bpo-34037(5).)

   * The constant values of future flags in the *note __future__: 0.
     module is updated in order to prevent collision with compiler
     flags.  Previously ‘PyCF_ALLOW_TOP_LEVEL_AWAIT’ was clashing with
     ‘CO_FUTURE_DIVISION’.  (Contributed by Batuhan Taskaya in
     bpo-39562(6))

   * ‘array('u')’ now uses ‘wchar_t’ as C type instead of ‘Py_UNICODE’.
     This change doesn’t affect to its behavior because ‘Py_UNICODE’ is
     alias of ‘wchar_t’ since Python 3.3.  (Contributed by Inada Naoki
     in bpo-34538(7).)

   * The *note logging.getLogger(): b5b. API now returns the root logger
     when passed the name ‘'root'’, whereas previously it returned a
     non-root logger named ‘'root'’.  This could affect cases where user
     code explicitly wants a non-root logger named ‘'root'’, or
     instantiates a logger using ‘logging.getLogger(__name__)’ in some
     top-level module called ‘'root.py'’.  (Contributed by Vinay Sajip
     in bpo-37742(8).)

   * Division handling of *note PurePath: 6ce. now returns *note
     NotImplemented: 1a2. instead of raising a *note TypeError: 198.
     when passed something other than an instance of ‘str’ or *note
     PurePath: 6ce.  This allows creating compatible classes that don’t
     inherit from those mentioned types.  (Contributed by Roger Aiudi in
     bpo-34775(9)).

   * Starting with Python 3.9.5 the *note ipaddress: 84. module no
     longer accepts any leading zeros in IPv4 address strings.  Leading
     zeros are ambiguous and interpreted as octal notation by some
     libraries.  For example the legacy function *note
     socket.inet_aton(): b5c. treats leading zeros as octal notatation.
     glibc implementation of modern *note inet_pton(): b5d. does not
     accept any leading zeros.  (Contributed by Christian Heimes in
     bpo-36384(10)).

   * *note codecs.lookup(): b5e. now normalizes the encoding name the
     same way as *note encodings.normalize_encoding(): 9ff, except that
     *note codecs.lookup(): b5e. also converts the name to lower case.
     For example, ‘"latex+latin1"’ encoding name is now normalized to
     ‘"latex_latin1"’.  (Contributed by Jordon Xu in bpo-37751(11).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39239

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39357

   (3) https://bugs.python.org/issue?@action=redirect&bpo=34822

   (4) https://datatracker.ietf.org/doc/html/rfc2640.html

   (5) https://bugs.python.org/issue?@action=redirect&bpo=34037

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39562

   (7) https://bugs.python.org/issue?@action=redirect&bpo=34538

   (8) https://bugs.python.org/issue?@action=redirect&bpo=37742

   (9) https://bugs.python.org/issue?@action=redirect&bpo=34775

   (10) https://bugs.python.org/issue?@action=redirect&bpo=36384

   (11) https://bugs.python.org/issue?@action=redirect&bpo=37751


File: python.info,  Node: Changes in the C API<4>,  Next: CPython bytecode changes<4>,  Prev: Changes in the Python API<4>,  Up: Porting to Python 3 9

1.6.10.2 Changes in the C API
.............................

   * Instances of *note heap-allocated types: b60. (such as those
     created with *note PyType_FromSpec(): 79e. and similar APIs) hold a
     reference to their type object since Python 3.8.  As indicated in
     the «Changes in the C API» of Python 3.8, for the vast majority of
     cases, there should be no side effect but for types that have a
     custom *note tp_traverse: 983. function, ensure that all custom
     ‘tp_traverse’ functions of heap-allocated types visit the object’s
     type.

          Example:

               int
               foo_traverse(PyObject *self, visitproc visit, void *arg)
               {
               // Rest of the traverse function
               #if PY_VERSION_HEX >= 0x03090000
                   // This was not needed before Python 3.9 (Python issue 35810 and 40217)
                   Py_VISIT(Py_TYPE(self));
               #endif
               }

     If your traverse function delegates to ‘tp_traverse’ of its base
     class (or another type), ensure that ‘Py_TYPE(self)’ is visited
     only once.  Note that only *note heap type: b60. are expected to
     visit the type in ‘tp_traverse’.

          For example, if your ‘tp_traverse’ function includes:

               base->tp_traverse(self, visit, arg)

          then add:

               #if PY_VERSION_HEX >= 0x03090000
                   // This was not needed before Python 3.9 (bpo-35810 and bpo-40217)
                   if (base->tp_flags & Py_TPFLAGS_HEAPTYPE) {
                       // a heap type's tp_traverse already visited Py_TYPE(self)
                   } else {
                       Py_VISIT(Py_TYPE(self));
                   }
               #else

     (See bpo-35810(1) and bpo-40217(2) for more information.)

   * The functions ‘PyEval_CallObject’, ‘PyEval_CallFunction’,
     ‘PyEval_CallMethod’ and ‘PyEval_CallObjectWithKeywords’ are
     deprecated.  Use *note PyObject_Call(): 63d. and its variants
     instead.  (See more details in bpo-29548(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35810

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40217

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29548


File: python.info,  Node: CPython bytecode changes<4>,  Prev: Changes in the C API<4>,  Up: Porting to Python 3 9

1.6.10.3 CPython bytecode changes
.................................

   * The ‘LOAD_ASSERTION_ERROR’ opcode was added for handling the *note
     assert: b62. statement.  Previously, the assert statement would not
     work correctly if the *note AssertionError: 8b9. exception was
     being shadowed.  (Contributed by Zackery Spytz in bpo-34880(1).)

   * The *note COMPARE_OP: b63. opcode was split into four distinct
     instructions:

        * ‘COMPARE_OP’ for rich comparisons

        * ‘IS_OP’ for “is” and “is not” tests

        * ‘CONTAINS_OP’ for “in” and “not in” tests

        * ‘JUMP_IF_NOT_EXC_MATCH’ for checking exceptions in
          “try-except” statements.

     (Contributed by Mark Shannon in bpo-39156(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34880

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39156


File: python.info,  Node: Build Changes<4>,  Next: C API Changes<4>,  Prev: Porting to Python 3 9,  Up: What’s New In Python 3 9

1.6.11 Build Changes
--------------------

   * Added ‘--with-platlibdir’ option to the ‘configure’ script: name of
     the platform-specific library directory, stored in the new *note
     sys.platlibdir: b34. attribute.  See *note sys.platlibdir: b34.
     attribute for more information.  (Contributed by Jan Matějek, Matěj
     Cepl, Charalampos Stratakis and Victor Stinner in bpo-1294959(1).)

   * The ‘COUNT_ALLOCS’ special build macro has been removed.
     (Contributed by Victor Stinner in bpo-39489(2).)

   * On non-Windows platforms, the ‘setenv()’ and ‘unsetenv()’ functions
     are now required to build Python.  (Contributed by Victor Stinner
     in bpo-39395(3).)

   * On non-Windows platforms, creating ‘bdist_wininst’ installers is
     now officially unsupported.  (See bpo-10945(4) for more details.)

   * When building Python on macOS from source, ‘_tkinter’ now links
     with non-system Tcl and Tk frameworks if they are installed in
     ‘/Library/Frameworks’, as had been the case on older releases of
     macOS. If a macOS SDK is explicitly configured, by using *note
     -enable-universalsdk: b65. or ‘-isysroot’, only the SDK itself is
     searched.  The default behavior can still be overridden with
     ‘--with-tcltk-includes’ and ‘--with-tcltk-libs’.  (Contributed by
     Ned Deily in bpo-34956(5).)

   * Python can now be built for Windows 10 ARM64.  (Contributed by
     Steve Dower in bpo-33125(6).)

   * Some individual tests are now skipped when ‘--pgo’ is used.  The
     tests in question increased the PGO task time significantly and
     likely didn’t help improve optimization of the final executable.
     This speeds up the task by a factor of about 15x.  Running the full
     unit test suite is slow.  This change may result in a slightly less
     optimized build since not as many code branches will be executed.
     If you are willing to wait for the much slower build, the old
     behavior can be restored using ‘./configure [..] PROFILE_TASK="-m
     test --pgo-extended"’.  We make no guarantees as to which PGO task
     set produces a faster build.  Users who care should run their own
     relevant benchmarks as results can depend on the environment,
     workload, and compiler tool chain.  (See bpo-36044(7) and
     bpo-37707(8) for more details.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1294959

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39489

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39395

   (4) https://bugs.python.org/issue?@action=redirect&bpo=10945

   (5) https://bugs.python.org/issue?@action=redirect&bpo=34956

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33125

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36044

   (8) https://bugs.python.org/issue?@action=redirect&bpo=37707


File: python.info,  Node: C API Changes<4>,  Next: Notable changes in Python 3 9 1,  Prev: Build Changes<4>,  Up: What’s New In Python 3 9

1.6.12 C API Changes
--------------------

* Menu:

* New Features: New Features<8>.
* Porting to Python 3.9: Porting to Python 3 9<2>.
* Removed: Removed<7>.


File: python.info,  Node: New Features<8>,  Next: Porting to Python 3 9<2>,  Up: C API Changes<4>

1.6.12.1 New Features
.....................

   * PEP 573(1): Added *note PyType_FromModuleAndSpec(): 774. to
     associate a module with a class; *note PyType_GetModule(): b68. and
     *note PyType_GetModuleState(): b69. to retrieve the module and its
     state; and *note PyCMethod: 969. and *note METH_METHOD: b6a. to
     allow a method to access the class it was defined in.  (Contributed
     by Marcel Plch and Petr Viktorin in bpo-38787(2).)

   * Added *note PyFrame_GetCode(): 98e. function: get a frame code.
     Added *note PyFrame_GetBack(): 98a. function: get the frame next
     outer frame.  (Contributed by Victor Stinner in bpo-40421(3).)

   * Added *note PyFrame_GetLineNumber(): 98f. to the limited C API.
     (Contributed by Victor Stinner in bpo-40421(4).)

   * Added *note PyThreadState_GetInterpreter(): b6b. and *note
     PyInterpreterState_Get(): 64c. functions to get the interpreter.
     Added *note PyThreadState_GetFrame(): 992. function to get the
     current frame of a Python thread state.  Added *note
     PyThreadState_GetID(): b6c. function: get the unique identifier of
     a Python thread state.  (Contributed by Victor Stinner in
     bpo-39947(5).)

   * Added a new public *note PyObject_CallNoArgs(): 63c. function to
     the C API, which calls a callable Python object without any
     arguments.  It is the most efficient way to call a callable Python
     object without any argument.  (Contributed by Victor Stinner in
     bpo-37194(6).)

   * Changes in the limited C API (if ‘Py_LIMITED_API’ macro is
     defined):

        * Provide *note Py_EnterRecursiveCall(): 3d2. and *note
          Py_LeaveRecursiveCall(): b6d. as regular functions for the
          limited API. Previously, there were defined as macros, but
          these macros didn’t compile with the limited C API which
          cannot access ‘PyThreadState.recursion_depth’ field (the
          structure is opaque in the limited C API).

        * ‘PyObject_INIT()’ and ‘PyObject_INIT_VAR()’ become regular
          «opaque» function to hide implementation details.

     (Contributed by Victor Stinner in bpo-38644(7) and bpo-39542(8).)

   * The *note PyModule_AddType(): b6e. function is added to help adding
     a type to a module.  (Contributed by Donghee Na in bpo-40024(9).)

   * Added the functions *note PyObject_GC_IsTracked(): b6f. and *note
     PyObject_GC_IsFinalized(): b70. to the public API to allow to query
     if Python objects are being currently tracked or have been already
     finalized by the garbage collector respectively.  (Contributed by
     Pablo Galindo Salgado in bpo-40241(10).)

   * Added ‘_PyObject_FunctionStr()’ to get a user-friendly string
     representation of a function-like object.  (Patch by Jeroen Demeyer
     in bpo-37645(11).)

   * Added *note PyObject_CallOneArg(): b71. for calling an object with
     one positional argument (Patch by Jeroen Demeyer in bpo-37483(12).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0573/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38787

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40421

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40421

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39947

   (6) https://bugs.python.org/issue?@action=redirect&bpo=37194

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38644

   (8) https://bugs.python.org/issue?@action=redirect&bpo=39542

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40024

   (10) https://bugs.python.org/issue?@action=redirect&bpo=40241

   (11) https://bugs.python.org/issue?@action=redirect&bpo=37645

   (12) https://bugs.python.org/issue?@action=redirect&bpo=37483


File: python.info,  Node: Porting to Python 3 9<2>,  Next: Removed<7>,  Prev: New Features<8>,  Up: C API Changes<4>

1.6.12.2 Porting to Python 3.9
..............................

   * ‘PyInterpreterState.eval_frame’ ( PEP 523(1)) now requires a new
     mandatory 'tstate' parameter (‘PyThreadState*’).  (Contributed by
     Victor Stinner in bpo-38500(2).)

   * Extension modules: *note m_traverse: b73, *note m_clear: b74. and
     *note m_free: b75. functions of *note PyModuleDef: b76. are no
     longer called if the module state was requested but is not
     allocated yet.  This is the case immediately after the module is
     created and before the module is executed (*note Py_mod_exec: b77.
     function).  More precisely, these functions are not called if *note
     m_size: b78. is greater than 0 and the module state (as returned by
     *note PyModule_GetState(): b79.) is ‘NULL’.

     Extension modules without module state (‘m_size <= 0’) are not
     affected.

   * If *note Py_AddPendingCall(): b7a. is called in a subinterpreter,
     the function is now scheduled to be called from the subinterpreter,
     rather than being called from the main interpreter.  Each
     subinterpreter now has its own list of scheduled calls.
     (Contributed by Victor Stinner in bpo-39984(3).)

   * The Windows registry is no longer used to initialize *note
     sys.path: 3e4. when the ‘-E’ option is used (if *note
     PyConfig.use_environment: 40b. is set to ‘0’).  This is significant
     when embedding Python on Windows.  (Contributed by Zackery Spytz in
     bpo-8901(4).)

   * The global variable *note PyStructSequence_UnnamedField: b7b. is
     now a constant and refers to a constant string.  (Contributed by
     Serhiy Storchaka in bpo-38650(5).)

   * The ‘PyGC_Head’ structure is now opaque.  It is only defined in the
     internal C API (‘pycore_gc.h’).  (Contributed by Victor Stinner in
     bpo-40241(6).)

   * The ‘Py_UNICODE_COPY’, ‘Py_UNICODE_FILL’, ‘PyUnicode_WSTR_LENGTH’,
     ‘PyUnicode_FromUnicode()’, ‘PyUnicode_AsUnicode()’,
     ‘_PyUnicode_AsUnicode’, and ‘PyUnicode_AsUnicodeAndSize()’ are
     marked as deprecated in C. They have been deprecated by PEP 393(7)
     since Python 3.3.  (Contributed by Inada Naoki in bpo-36346(8).)

   * The *note Py_FatalError(): b7c. function is replaced with a macro
     which logs automatically the name of the current function, unless
     the ‘Py_LIMITED_API’ macro is defined.  (Contributed by Victor
     Stinner in bpo-39882(9).)

   * The vectorcall protocol now requires that the caller passes only
     strings as keyword names.  (See bpo-37540(10) for more
     information.)

   * Implementation details of a number of macros and functions are now
     hidden:

        * *note PyObject_IS_GC(): b7d. macro was converted to a
          function.

        * The ‘PyObject_NEW()’ macro becomes an alias to the *note
          PyObject_New: b7e. macro, and the ‘PyObject_NEW_VAR()’ macro
          becomes an alias to the *note PyObject_NewVar: b7f. macro.
          They no longer access directly the *note
          PyTypeObject.tp_basicsize: b80. member.

        * ‘PyObject_GET_WEAKREFS_LISTPTR()’ macro was converted to a
          function: the macro accessed directly the *note
          PyTypeObject.tp_weaklistoffset: b81. member.

        * *note PyObject_CheckBuffer(): 639. macro was converted to a
          function: the macro accessed directly the *note
          PyTypeObject.tp_as_buffer: b82. member.

        * *note PyIndex_Check(): b83. is now always declared as an
          opaque function to hide implementation details: removed the
          ‘PyIndex_Check()’ macro.  The macro accessed directly the
          *note PyTypeObject.tp_as_number: b84. member.

     (See bpo-40170(11) for more details.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0523/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38500

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39984

   (4) https://bugs.python.org/issue?@action=redirect&bpo=8901

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38650

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40241

   (7) https://peps.python.org/pep-0393/

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36346

   (9) https://bugs.python.org/issue?@action=redirect&bpo=39882

   (10) https://bugs.python.org/issue?@action=redirect&bpo=37540

   (11) https://bugs.python.org/issue?@action=redirect&bpo=40170


File: python.info,  Node: Removed<7>,  Prev: Porting to Python 3 9<2>,  Up: C API Changes<4>

1.6.12.3 Removed
................

   * Excluded ‘PyFPE_START_PROTECT()’ and ‘PyFPE_END_PROTECT()’ macros
     of ‘pyfpe.h’ from the limited C API. (Contributed by Victor Stinner
     in bpo-38835(1).)

   * The ‘tp_print’ slot of *note PyTypeObject: b86. has been removed.
     It was used for printing objects to files in Python 2.7 and before.
     Since Python 3.0, it has been ignored and unused.  (Contributed by
     Jeroen Demeyer in bpo-36974(2).)

   * Changes in the limited C API (if ‘Py_LIMITED_API’ macro is
     defined):

        * Excluded the following functions from the limited C API:

             * ‘PyThreadState_DeleteCurrent()’ (Contributed by Joannah
               Nanjekye in bpo-37878(3).)

             * ‘_Py_CheckRecursionLimit’

             * ‘_Py_NewReference()’

             * ‘_Py_ForgetReference()’

             * ‘_PyTraceMalloc_NewReference()’

             * ‘_Py_GetRefTotal()’

             * The trashcan mechanism which never worked in the limited
               C API.

             * ‘PyTrash_UNWIND_LEVEL’

             * ‘Py_TRASHCAN_BEGIN_CONDITION’

             * ‘Py_TRASHCAN_BEGIN’

             * ‘Py_TRASHCAN_END’

             * ‘Py_TRASHCAN_SAFE_BEGIN’

             * ‘Py_TRASHCAN_SAFE_END’

        * Moved following functions and definitions to the internal C
          API:

             * ‘_PyDebug_PrintTotalRefs()’

             * ‘_Py_PrintReferences()’

             * ‘_Py_PrintReferenceAddresses()’

             * ‘_Py_tracemalloc_config’

             * ‘_Py_AddToAllObjects()’ (specific to ‘Py_TRACE_REFS’
               build)

     (Contributed by Victor Stinner in bpo-38644(4) and bpo-39542(5).)

   * Removed ‘_PyRuntime.getframe’ hook and removed
     ‘_PyThreadState_GetFrame’ macro which was an alias to
     ‘_PyRuntime.getframe’.  They were only exposed by the internal C
     API. Removed also ‘PyThreadFrameGetter’ type.  (Contributed by
     Victor Stinner in bpo-39946(6).)

   * Removed the following functions from the C API. Call *note
     PyGC_Collect(): b87. explicitly to clear all free lists.
     (Contributed by Inada Naoki and Victor Stinner in bpo-37340(7),
     bpo-38896(8) and bpo-40428(9).)

        * ‘PyAsyncGen_ClearFreeLists()’

        * ‘PyContext_ClearFreeList()’

        * ‘PyDict_ClearFreeList()’

        * ‘PyFloat_ClearFreeList()’

        * ‘PyFrame_ClearFreeList()’

        * ‘PyList_ClearFreeList()’

        * ‘PyMethod_ClearFreeList()’ and ‘PyCFunction_ClearFreeList()’:
          the free lists of bound method objects have been removed.

        * ‘PySet_ClearFreeList()’: the set free list has been removed in
          Python 3.4.

        * ‘PyTuple_ClearFreeList()’

        * ‘PyUnicode_ClearFreeList()’: the Unicode free list has been
          removed in Python 3.3.

   * Removed ‘_PyUnicode_ClearStaticStrings()’ function.  (Contributed
     by Victor Stinner in bpo-39465(10).)

   * Removed ‘Py_UNICODE_MATCH’.  It has been deprecated by PEP 393(11),
     and broken since Python 3.3.  The *note PyUnicode_Tailmatch(): ab7.
     function can be used instead.  (Contributed by Inada Naoki in
     bpo-36346(12).)

   * Cleaned header files of interfaces defined but with no
     implementation.  The public API symbols being removed are:
     ‘_PyBytes_InsertThousandsGroupingLocale’,
     ‘_PyBytes_InsertThousandsGrouping’, ‘_Py_InitializeFromArgs’,
     ‘_Py_InitializeFromWideArgs’, ‘_PyFloat_Repr’, ‘_PyFloat_Digits’,
     ‘_PyFloat_DigitsInit’, ‘PyFrame_ExtendStack’,
     ‘_PyAIterWrapper_Type’, ‘PyNullImporter_Type’, ‘PyCmpWrapper_Type’,
     ‘PySortWrapper_Type’, ‘PyNoArgsFunction’.  (Contributed by Pablo
     Galindo Salgado in bpo-39372(13).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38835

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36974

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37878

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38644

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39542

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39946

   (7) https://bugs.python.org/issue?@action=redirect&bpo=37340

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38896

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40428

   (10) https://bugs.python.org/issue?@action=redirect&bpo=39465

   (11) https://peps.python.org/pep-0393/

   (12) https://bugs.python.org/issue?@action=redirect&bpo=36346

   (13) https://bugs.python.org/issue?@action=redirect&bpo=39372


File: python.info,  Node: Notable changes in Python 3 9 1,  Next: Notable changes in Python 3 9 2,  Prev: C API Changes<4>,  Up: What’s New In Python 3 9

1.6.13 Notable changes in Python 3.9.1
--------------------------------------

* Menu:

* typing: typing<8>.
* macOS 11.0 (Big Sur) and Apple Silicon Mac support: macOS 11 0 Big Sur and Apple Silicon Mac support.


File: python.info,  Node: typing<8>,  Next: macOS 11 0 Big Sur and Apple Silicon Mac support,  Up: Notable changes in Python 3 9 1

1.6.13.1 typing
...............

The behavior of *note typing.Literal: a57. was changed to conform with
PEP 586(1) and to match the behavior of static type checkers specified
in the PEP.

  1. ‘Literal’ now de-duplicates parameters.

  2. Equality comparisons between ‘Literal’ objects are now order
     independent.

  3. ‘Literal’ comparisons now respect types.  For example, ‘Literal[0]
     == Literal[False]’ previously evaluated to ‘True’.  It is now
     ‘False’.  To support this change, the internally used type cache
     now supports differentiating types.

  4. ‘Literal’ objects will now raise a *note TypeError: 198. exception
     during equality comparisons if any of their parameters are not
     *note hashable: 825.  Note that declaring ‘Literal’ with mutable
     parameters will not throw an error:

          >>> from typing import Literal
          >>> Literal[{0}]
          >>> Literal[{0}] == Literal[{False}]
          Traceback (most recent call last):
            File "<stdin>", line 1, in <module>
          TypeError: unhashable type: 'set'

(Contributed by Yurii Karabas in bpo-42345(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0586/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42345


File: python.info,  Node: macOS 11 0 Big Sur and Apple Silicon Mac support,  Prev: typing<8>,  Up: Notable changes in Python 3 9 1

1.6.13.2 macOS 11.0 (Big Sur) and Apple Silicon Mac support
...........................................................

As of 3.9.1, Python now fully supports building and running on macOS
11.0 (Big Sur) and on Apple Silicon Macs (based on the ‘ARM64’
architecture).  A new universal build variant, ‘universal2’, is now
available to natively support both ‘ARM64’ and ‘Intel 64’ in one set of
executables.  Binaries can also now be built on current versions of
macOS to be deployed on a range of older macOS versions (tested to 10.9)
while making some newer OS functions and options conditionally available
based on the operating system version in use at runtime («weaklinking»).

(Contributed by Ronald Oussoren and Lawrence D’Anna in bpo-41100(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41100


File: python.info,  Node: Notable changes in Python 3 9 2,  Next: Notable changes in Python 3 9 3,  Prev: Notable changes in Python 3 9 1,  Up: What’s New In Python 3 9

1.6.14 Notable changes in Python 3.9.2
--------------------------------------

* Menu:

* collections.abc: collections abc<2>.
* urllib.parse: urllib parse<2>.


File: python.info,  Node: collections abc<2>,  Next: urllib parse<2>,  Up: Notable changes in Python 3 9 2

1.6.14.1 collections.abc
........................

*note collections.abc.Callable: 9ed. generic now flattens type
parameters, similar to what *note typing.Callable: 9ca. currently does.
This means that ‘collections.abc.Callable[[int, str], str]’ will have
‘__args__’ of ‘(int, str, str)’; previously this was ‘([int, str],
str)’.  To allow this change, *note types.GenericAlias: 9ee. can now be
subclassed, and a subclass will be returned when subscripting the *note
collections.abc.Callable: 9ed. type.  Code which accesses the arguments
via *note typing.get_args(): 2ac. or ‘__args__’ need to account for this
change.  A *note DeprecationWarning: 1a3. may be emitted for invalid
forms of parameterizing *note collections.abc.Callable: 9ed. which may
have passed silently in Python 3.9.1.  This *note DeprecationWarning:
1a3. will become a *note TypeError: 198. in Python 3.10.  (Contributed
by Ken Jin in bpo-42195(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42195


File: python.info,  Node: urllib parse<2>,  Prev: collections abc<2>,  Up: Notable changes in Python 3 9 2

1.6.14.2 urllib.parse
.....................

Earlier Python versions allowed using both ‘;’ and ‘&’ as query
parameter separators in *note urllib.parse.parse_qs(): 31f. and *note
urllib.parse.parse_qsl(): 31e.  Due to security concerns, and to conform
with newer W3C recommendations, this has been changed to allow only a
single separator key, with ‘&’ as the default.  This change also affects
‘cgi.parse()’ and ‘cgi.parse_multipart()’ as they use the affected
functions internally.  For more details, please see their respective
documentation.  (Contributed by Adam Goldschmidt, Senthil Kumaran and
Ken Jin in bpo-42967(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42967


File: python.info,  Node: Notable changes in Python 3 9 3,  Next: Notable changes in Python 3 9 5,  Prev: Notable changes in Python 3 9 2,  Up: What’s New In Python 3 9

1.6.15 Notable changes in Python 3.9.3
--------------------------------------

A security fix alters the *note ftplib.FTP: af8. behavior to not trust
the IPv4 address sent from the remote server when setting up a passive
data channel.  We reuse the ftp server IP address instead.  For unusual
code requiring the old behavior, set a ‘trust_server_pasv_ipv4_address’
attribute on your FTP instance to ‘True’.  (See gh-87451(1))

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/87451


File: python.info,  Node: Notable changes in Python 3 9 5,  Next: Notable security feature in 3 9 14,  Prev: Notable changes in Python 3 9 3,  Up: What’s New In Python 3 9

1.6.16 Notable changes in Python 3.9.5
--------------------------------------

* Menu:

* urllib.parse: urllib parse<3>.


File: python.info,  Node: urllib parse<3>,  Up: Notable changes in Python 3 9 5

1.6.16.1 urllib.parse
.....................

The presence of newline or tab characters in parts of a URL allows for
some forms of attacks.  Following the WHATWG specification that updates
RFC 3986(1), ASCII newline ‘\n’, ‘\r’ and tab ‘\t’ characters are
stripped from the URL by the parser in *note urllib.parse: 110.
preventing such attacks.  The removal characters are controlled by a new
module level variable ‘urllib.parse._UNSAFE_URL_BYTES_TO_REMOVE’.  (See
gh-88048(2))

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc3986.html

   (2) https://github.com/python/cpython/issues/88048


File: python.info,  Node: Notable security feature in 3 9 14,  Next: Notable changes in 3 9 17,  Prev: Notable changes in Python 3 9 5,  Up: What’s New In Python 3 9

1.6.17 Notable security feature in 3.9.14
-----------------------------------------

Converting between *note int: 19b. and *note str: 169. in bases other
than 2 (binary), 4, 8 (octal), 16 (hexadecimal), or 32 such as base 10
(decimal) now raises a *note ValueError: 2ec. if the number of digits in
string form is above a limit to avoid potential denial of service
attacks due to the algorithmic complexity.  This is a mitigation for CVE
2020-10735(1).  This limit can be configured or disabled by environment
variable, command line flag, or *note sys: df. APIs.  See the *note
integer string conversion length limitation: 80c. documentation.  The
default limit is 4300 digits in string form.

   ---------- Footnotes ----------

   (1) https://www.cve.org/CVERecord?id=CVE-2020-10735


File: python.info,  Node: Notable changes in 3 9 17,  Prev: Notable security feature in 3 9 14,  Up: What’s New In Python 3 9

1.6.18 Notable changes in 3.9.17
--------------------------------

* Menu:

* tarfile: tarfile<4>.


File: python.info,  Node: tarfile<4>,  Up: Notable changes in 3 9 17

1.6.18.1 tarfile
................

   * The extraction methods in *note tarfile: e4, and *note
     shutil.unpack_archive(): 697, have a new a 'filter' argument that
     allows limiting tar features than may be surprising or dangerous,
     such as creating files outside the destination directory.  See
     *note Extraction filters: 698. for details.  In Python 3.12, use
     without the 'filter' argument will show a *note DeprecationWarning:
     1a3.  In Python 3.14, the default will switch to ‘'data'’.
     (Contributed by Petr Viktorin in PEP 706(1).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0706/


File: python.info,  Node: What’s New In Python 3 8,  Next: What’s New In Python 3 7,  Prev: What’s New In Python 3 9,  Up: Novità in Python

1.7 What’s New In Python 3.8
============================


Editor: Raymond Hettinger

This article explains the new features in Python 3.8, compared to 3.7.
Python 3.8 was released on October 14, 2019.  For full details, see the
*note changelog: 142.

* Menu:

* Summary – Release highlights: Summary – Release highlights<5>.
* New Features: New Features<9>.
* Other Language Changes: Other Language Changes<5>.
* New Modules: New Modules<5>.
* Improved Modules: Improved Modules<5>.
* Optimizations: Optimizations<6>.
* Build and C API Changes::
* Deprecated: Deprecated<7>.
* API and Feature Removals::
* Porting to Python 3.8: Porting to Python 3 8.
* Notable changes in Python 3.8.1: Notable changes in Python 3 8 1.
* Notable changes in Python 3.8.2: Notable changes in Python 3 8 2.
* Notable changes in Python 3.8.3: Notable changes in Python 3 8 3.
* Notable changes in Python 3.8.8: Notable changes in Python 3 8 8.
* Notable changes in Python 3.8.9: Notable changes in Python 3 8 9.
* Notable changes in Python 3.8.10: Notable changes in Python 3 8 10.
* Notable changes in Python 3.8.10: Notable changes in Python 3 8 10<2>.
* Notable changes in Python 3.8.12: Notable changes in Python 3 8 12.
* Notable security feature in 3.8.14: Notable security feature in 3 8 14.
* Notable changes in 3.8.17: Notable changes in 3 8 17.


File: python.info,  Node: Summary – Release highlights<5>,  Next: New Features<9>,  Up: What’s New In Python 3 8

1.7.1 Summary – Release highlights
----------------------------------


File: python.info,  Node: New Features<9>,  Next: Other Language Changes<5>,  Prev: Summary – Release highlights<5>,  Up: What’s New In Python 3 8

1.7.2 New Features
------------------

* Menu:

* Assignment expressions::
* Positional-only parameters::
* Parallel filesystem cache for compiled bytecode files::
* Debug build uses the same ABI as release build::
* f-strings support = for self-documenting expressions and debugging::
* PEP 578; Python Runtime Audit Hooks: PEP 578 Python Runtime Audit Hooks.
* PEP 587; Python Initialization Configuration: PEP 587 Python Initialization Configuration.
* PEP 590; Vectorcall; a fast calling protocol for CPython: PEP 590 Vectorcall a fast calling protocol for CPython.
* Pickle protocol 5 with out-of-band data buffers::


File: python.info,  Node: Assignment expressions,  Next: Positional-only parameters,  Up: New Features<9>

1.7.2.1 Assignment expressions
..............................

There is new syntax ‘:=’ that assigns values to variables as part of a
larger expression.  It is affectionately known as «the walrus operator»
due to its resemblance to the eyes and tusks of a walrus(1).

In this example, the assignment expression helps avoid calling *note
len(): 841. twice:

     if (n := len(a)) > 10:
         print(f"List is too long ({n} elements, expected <= 10)")

A similar benefit arises during regular expression matching where match
objects are needed twice, once to test whether a match occurred and
another to extract a subgroup:

     discount = 0.0
     if (mo := re.search(r'(\d+)% discount', advertisement)):
         discount = float(mo.group(1)) / 100.0

The operator is also useful with while-loops that compute a value to
test loop termination and then need that same value again in the body of
the loop:

     # Loop over fixed length blocks
     while (block := f.read(256)) != '':
         process(block)

Another motivating use case arises in list comprehensions where a value
computed in a filtering condition is also needed in the expression body:

     [clean_name.title() for name in names
      if (clean_name := normalize('NFC', name)) in allowed_names]

Try to limit use of the walrus operator to clean cases that reduce
complexity and improve readability.

See PEP 572(2) for a full description.

(Contributed by Emily Morehouse in bpo-35224(3).)

   ---------- Footnotes ----------

   (1) 
https://en.wikipedia.org/wiki/Walrus#/media/File:Pacific_Walrus_-_Bull_(8247646168).jpg

   (2) https://peps.python.org/pep-0572/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35224


File: python.info,  Node: Positional-only parameters,  Next: Parallel filesystem cache for compiled bytecode files,  Prev: Assignment expressions,  Up: New Features<9>

1.7.2.2 Positional-only parameters
..................................

There is a new function parameter syntax ‘/’ to indicate that some
function parameters must be specified positionally and cannot be used as
keyword arguments.  This is the same notation shown by ‘help()’ for C
functions annotated with Larry Hastings” Argument Clinic(1) tool.

In the following example, parameters 'a' and 'b' are positional-only,
while 'c' or 'd' can be positional or keyword, and 'e' or 'f' are
required to be keywords:

     def f(a, b, /, c, d, *, e, f):
         print(a, b, c, d, e, f)

The following is a valid call:

     f(10, 20, 30, d=40, e=50, f=60)

However, these are invalid calls:

     f(10, b=20, c=30, d=40, e=50, f=60)   # b cannot be a keyword argument
     f(10, 20, 30, 40, 50, f=60)           # e must be a keyword argument

One use case for this notation is that it allows pure Python functions
to fully emulate behaviors of existing C coded functions.  For example,
the built-in *note divmod(): b9b. function does not accept keyword
arguments:

     def divmod(a, b, /):
         "Emulate the built in divmod() function"
         return (a // b, a % b)

Another use case is to preclude keyword arguments when the parameter
name is not helpful.  For example, the builtin *note len(): 841.
function has the signature ‘len(obj, /)’.  This precludes awkward calls
such as:

     len(obj='hello')  # The "obj" keyword argument impairs readability

A further benefit of marking a parameter as positional-only is that it
allows the parameter name to be changed in the future without risk of
breaking client code.  For example, in the *note statistics: d7. module,
the parameter name 'dist' may be changed in the future.  This was made
possible with the following function specification:

     def quantiles(dist, /, *, n=4, method='exclusive')
         ...

Since the parameters to the left of ‘/’ are not exposed as possible
keywords, the parameters names remain available for use in ‘**kwargs’:

     >>> def f(a, b, /, **kwargs):
     ...     print(a, b, kwargs)
     ...
     >>> f(10, 20, a=1, b=2, c=3)         # a and b are used in two ways
     10 20 {'a': 1, 'b': 2, 'c': 3}

This greatly simplifies the implementation of functions and methods that
need to accept arbitrary keyword arguments.  For example, here is an
excerpt from code in the *note collections: 1e. module:

     class Counter(dict):

         def __init__(self, iterable=None, /, **kwds):
             # Note "iterable" is a possible keyword argument

See PEP 570(2) for a full description.

(Contributed by Pablo Galindo in bpo-36540(3).)

   ---------- Footnotes ----------

   (1) https://devguide.python.org/development-tools/clinic/

   (2) https://peps.python.org/pep-0570/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36540


File: python.info,  Node: Parallel filesystem cache for compiled bytecode files,  Next: Debug build uses the same ABI as release build,  Prev: Positional-only parameters,  Up: New Features<9>

1.7.2.3 Parallel filesystem cache for compiled bytecode files
.............................................................

The new *note PYTHONPYCACHEPREFIX: b9d. setting (also available as *note
-X: 16f. ‘pycache_prefix’) configures the implicit bytecode cache to use
a separate parallel filesystem tree, rather than the default
‘__pycache__’ subdirectories within each source directory.

The location of the cache is reported in *note sys.pycache_prefix: b9e.
(*note None: 886. indicates the default location in ‘__pycache__’
subdirectories).

(Contributed by Carl Meyer in bpo-33499(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33499


File: python.info,  Node: Debug build uses the same ABI as release build,  Next: f-strings support = for self-documenting expressions and debugging,  Prev: Parallel filesystem cache for compiled bytecode files,  Up: New Features<9>

1.7.2.4 Debug build uses the same ABI as release build
......................................................

Python now uses the same ABI whether it’s built in release or debug
mode.  On Unix, when Python is built in debug mode, it is now possible
to load C extensions built in release mode and C extensions built using
the stable ABI.

Release builds and *note debug builds: 50a. are now ABI compatible:
defining the ‘Py_DEBUG’ macro no longer implies the ‘Py_TRACE_REFS’
macro, which introduces the only ABI incompatibility.  The
‘Py_TRACE_REFS’ macro, which adds the *note sys.getobjects(): 28e.
function and the *note PYTHONDUMPREFS: ba0. environment variable, can be
set using the new *note ./configure -with-trace-refs: 636. build option.
(Contributed by Victor Stinner in bpo-36465(1).)

On Unix, C extensions are no longer linked to libpython except on
Android and Cygwin.  It is now possible for a statically linked Python
to load a C extension built using a shared library Python.  (Contributed
by Victor Stinner in bpo-21536(2).)

On Unix, when Python is built in debug mode, import now also looks for C
extensions compiled in release mode and for C extensions compiled with
the stable ABI. (Contributed by Victor Stinner in bpo-36722(3).)

To embed Python into an application, a new ‘--embed’ option must be
passed to ‘python3-config --libs --embed’ to get ‘-lpython3.8’ (link the
application to libpython).  To support both 3.8 and older, try
‘python3-config --libs --embed’ first and fallback to ‘python3-config
--libs’ (without ‘--embed’) if the previous command fails.

Add a pkg-config ‘python-3.8-embed’ module to embed Python into an
application: ‘pkg-config python-3.8-embed --libs’ includes
‘-lpython3.8’.  To support both 3.8 and older, try ‘pkg-config
python-X.Y-embed --libs’ first and fallback to ‘pkg-config python-X.Y
--libs’ (without ‘--embed’) if the previous command fails (replace ‘X.Y’
with the Python version).

On the other hand, ‘pkg-config python3.8 --libs’ no longer contains
‘-lpython3.8’.  C extensions must not be linked to libpython (except on
Android and Cygwin, whose cases are handled by the script); this change
is backward incompatible on purpose.  (Contributed by Victor Stinner in
bpo-36721(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36465

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21536

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36722

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36721


File: python.info,  Node: f-strings support = for self-documenting expressions and debugging,  Next: PEP 578 Python Runtime Audit Hooks,  Prev: Debug build uses the same ABI as release build,  Up: New Features<9>

1.7.2.5 f-strings support ‘=’ for self-documenting expressions and debugging
............................................................................

Added an ‘=’ specifier to *note f-string: 66b.s.  An f-string such as
‘f'{expr=}'’ will expand to the text of the expression, an equal sign,
then the representation of the evaluated expression.  For example:

     >>> user = 'eric_idle'
     >>> member_since = date(1975, 7, 31)
     >>> f'{user=} {member_since=}'
     "user='eric_idle' member_since=datetime.date(1975, 7, 31)"

The usual *note f-string format specifiers: 19a. allow more control over
how the result of the expression is displayed:

     >>> delta = date.today() - member_since
     >>> f'{user=!s}  {delta.days=:,d}'
     'user=eric_idle  delta.days=16,075'

The ‘=’ specifier will display the whole expression so that calculations
can be shown:

     >>> print(f'{theta=}  {cos(radians(theta))=:.3f}')
     theta=30  cos(radians(theta))=0.866

(Contributed by Eric V. Smith and Larry Hastings in bpo-36817(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36817


File: python.info,  Node: PEP 578 Python Runtime Audit Hooks,  Next: PEP 587 Python Initialization Configuration,  Prev: f-strings support = for self-documenting expressions and debugging,  Up: New Features<9>

1.7.2.6 PEP 578: Python Runtime Audit Hooks
...........................................

The PEP adds an Audit Hook and Verified Open Hook.  Both are available
from Python and native code, allowing applications and frameworks
written in pure Python code to take advantage of extra notifications,
while also allowing embedders or system administrators to deploy builds
of Python where auditing is always enabled.

See PEP 578(1) for full details.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0578/


File: python.info,  Node: PEP 587 Python Initialization Configuration,  Next: PEP 590 Vectorcall a fast calling protocol for CPython,  Prev: PEP 578 Python Runtime Audit Hooks,  Up: New Features<9>

1.7.2.7 PEP 587: Python Initialization Configuration
....................................................

The PEP 587(1) adds a new C API to configure the Python Initialization
providing finer control on the whole configuration and better error
reporting.

New structures:

   * *note PyConfig: 3f7.

   * *note PyPreConfig: ba5.

   * *note PyStatus: ba6.

   * *note PyWideStringList: ba7.

New functions:

   * *note PyConfig_Clear(): ba8.

   * *note PyConfig_InitIsolatedConfig(): ba9.

   * *note PyConfig_InitPythonConfig(): baa.

   * *note PyConfig_Read(): 994.

   * *note PyConfig_SetArgv(): bab.

   * *note PyConfig_SetBytesArgv(): bac.

   * *note PyConfig_SetBytesString(): bad.

   * *note PyConfig_SetString(): bae.

   * *note PyPreConfig_InitIsolatedConfig(): baf.

   * *note PyPreConfig_InitPythonConfig(): bb0.

   * *note PyStatus_Error(): bb1.

   * *note PyStatus_Exception(): bb2.

   * *note PyStatus_Exit(): bb3.

   * *note PyStatus_IsError(): bb4.

   * *note PyStatus_IsExit(): bb5.

   * *note PyStatus_NoMemory(): bb6.

   * *note PyStatus_Ok(): bb7.

   * *note PyWideStringList_Append(): bb8.

   * *note PyWideStringList_Insert(): bb9.

   * *note Py_BytesMain(): bba.

   * *note Py_ExitStatusException(): bbb.

   * *note Py_InitializeFromConfig(): 3f6.

   * *note Py_PreInitialize(): 41e.

   * *note Py_PreInitializeFromArgs(): bbc.

   * *note Py_PreInitializeFromBytesArgs(): bbd.

   * *note Py_RunMain(): bbe.

This PEP also adds ‘_PyRuntimeState.preconfig’ (*note PyPreConfig: ba5.
type) and ‘PyInterpreterState.config’ (*note PyConfig: 3f7. type) fields
to these internal structures.  ‘PyInterpreterState.config’ becomes the
new reference configuration, replacing global configuration variables
and other private variables.

See *note Python Initialization Configuration: 646. for the
documentation.

See PEP 587(2) for a full description.

(Contributed by Victor Stinner in bpo-36763(3).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0587/

   (2) https://peps.python.org/pep-0587/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36763


File: python.info,  Node: PEP 590 Vectorcall a fast calling protocol for CPython,  Next: Pickle protocol 5 with out-of-band data buffers,  Prev: PEP 587 Python Initialization Configuration,  Up: New Features<9>

1.7.2.8 PEP 590: Vectorcall: a fast calling protocol for CPython
................................................................

*note The Vectorcall Protocol: 775. is added to the Python/C API. It is
meant to formalize existing optimizations which were already done for
various classes.  Any *note static type: 984. implementing a callable
can use this protocol.

This is currently provisional.  The aim is to make it fully public in
Python 3.9.

See PEP 590(1) for a full description.

(Contributed by Jeroen Demeyer, Mark Shannon and Petr Viktorin in
bpo-36974(2).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0590/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36974


File: python.info,  Node: Pickle protocol 5 with out-of-band data buffers,  Prev: PEP 590 Vectorcall a fast calling protocol for CPython,  Up: New Features<9>

1.7.2.9 Pickle protocol 5 with out-of-band data buffers
.......................................................

When *note pickle: ab. is used to transfer large data between Python
processes in order to take advantage of multi-core or multi-machine
processing, it is important to optimize the transfer by reducing memory
copies, and possibly by applying custom techniques such as
data-dependent compression.

The *note pickle: ab. protocol 5 introduces support for out-of-band
buffers where PEP 3118(1)-compatible data can be transmitted separately
from the main pickle stream, at the discretion of the communication
layer.

See PEP 574(2) for a full description.

(Contributed by Antoine Pitrou in bpo-36785(3).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3118/

   (2) https://peps.python.org/pep-0574/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36785


File: python.info,  Node: Other Language Changes<5>,  Next: New Modules<5>,  Prev: New Features<9>,  Up: What’s New In Python 3 8

1.7.3 Other Language Changes
----------------------------

   * A *note continue: 180. statement was illegal in the *note finally:
     1b0. clause due to a problem with the implementation.  In Python
     3.8 this restriction was lifted.  (Contributed by Serhiy Storchaka
     in bpo-32489(1).)

   * The *note bool: 3c3, *note int: 19b, and *note fractions.Fraction:
     213. types now have an *note as_integer_ratio(): bc2. method like
     that found in *note float: 196. and *note decimal.Decimal: 1fe.
     This minor API extension makes it possible to write ‘numerator,
     denominator = x.as_integer_ratio()’ and have it work across
     multiple numeric types.  (Contributed by Lisa Roach in bpo-33073(2)
     and Raymond Hettinger in bpo-37819(3).)

   * Constructors of *note int: 19b, *note float: 196. and *note
     complex: 197. will now use the *note __index__(): 19e. special
     method, if available and the corresponding method *note __int__():
     19d, *note __float__(): bc3. or *note __complex__(): 7fe. is not
     available.  (Contributed by Serhiy Storchaka in bpo-20092(4).)

   * Added support of ‘\N{NAME}’ escapes in *note regular expressions:
     be.:

          >>> notice = 'Copyright © 2019'
          >>> copyright_year_pattern = re.compile(r'\N{copyright sign}\s*(\d{4})')
          >>> int(copyright_year_pattern.search(notice).group(1))
          2019

     (Contributed by Jonathan Eunice and Serhiy Storchaka in
     bpo-30688(5).)

   * Dict and dictviews are now iterable in reversed insertion order
     using *note reversed(): a67.  (Contributed by Rémi Lapeyre in
     bpo-33462(6).)

   * The syntax allowed for keyword names in function calls was further
     restricted.  In particular, ‘f((keyword)=arg)’ is no longer
     allowed.  It was never intended to permit more than a bare name on
     the left-hand side of a keyword argument assignment term.
     (Contributed by Benjamin Peterson in bpo-34641(7).)

   * Generalized iterable unpacking in *note yield: bc4. and *note
     return: 1af. statements no longer requires enclosing parentheses.
     This brings the 'yield' and 'return' syntax into better agreement
     with normal assignment syntax:

          >>> def parse(family):
          ...     lastname, *members = family.split()
          ...     return lastname.upper(), *members
          ...
          >>> parse('simpsons homer marge bart lisa maggie')
          ('SIMPSONS', 'homer', 'marge', 'bart', 'lisa', 'maggie')

     (Contributed by David Cuthbert and Jordan Chapman in bpo-32117(8).)

   * When a comma is missed in code such as ‘[(10, 20) (30, 40)]’, the
     compiler displays a *note SyntaxWarning: 1ae. with a helpful
     suggestion.  This improves on just having a *note TypeError: 198.
     indicating that the first tuple was not callable.  (Contributed by
     Serhiy Storchaka in bpo-15248(9).)

   * Arithmetic operations between subclasses of *note datetime.date:
     1fa. or *note datetime.datetime: 4e3. and *note datetime.timedelta:
     bc5. objects now return an instance of the subclass, rather than
     the base class.  This also affects the return type of operations
     whose implementation (directly or indirectly) uses *note
     datetime.timedelta: bc5. arithmetic, such as *note astimezone():
     bc6.  (Contributed by Paul Ganssle in bpo-32417(10).)

   * When the Python interpreter is interrupted by Ctrl-C (SIGINT) and
     the resulting *note KeyboardInterrupt: bc7. exception is not
     caught, the Python process now exits via a SIGINT signal or with
     the correct exit code such that the calling process can detect that
     it died due to a Ctrl-C. Shells on POSIX and Windows use this to
     properly terminate scripts in interactive sessions.  (Contributed
     by Google via Gregory P. Smith in bpo-1054041(11).)

   * Some advanced styles of programming require updating the *note
     types.CodeType: 32f. object for an existing function.  Since code
     objects are immutable, a new code object needs to be created, one
     that is modeled on the existing code object.  With 19 parameters,
     this was somewhat tedious.  Now, the new ‘replace()’ method makes
     it possible to create a clone with a few altered parameters.

     Here’s an example that alters the *note statistics.mean(): 8e2.
     function to prevent the 'data' parameter from being used as a
     keyword argument:

          >>> from statistics import mean
          >>> mean(data=[10, 20, 90])
          40
          >>> mean.__code__ = mean.__code__.replace(co_posonlyargcount=1)
          >>> mean(data=[10, 20, 90])
          Traceback (most recent call last):
            ...
          TypeError: mean() got some positional-only arguments passed as keyword arguments: 'data'

     (Contributed by Victor Stinner in bpo-37032(12).)

   * For integers, the three-argument form of the *note pow(): 1a4.
     function now permits the exponent to be negative in the case where
     the base is relatively prime to the modulus.  It then computes a
     modular inverse to the base when the exponent is ‘-1’, and a
     suitable power of that inverse for other negative exponents.  For
     example, to compute the modular multiplicative inverse(13) of 38
     modulo 137, write:

          >>> pow(38, -1, 137)
          119
          >>> 119 * 38 % 137
          1

     Modular inverses arise in the solution of linear Diophantine
     equations(14).  For example, to find integer solutions for ‘4258𝑥 +
     147𝑦 = 369’, first rewrite as ‘4258𝑥 ≡ 369 (mod 147)’ then solve:

          >>> x = 369 * pow(4258, -1, 147) % 147
          >>> y = (4258 * x - 369) // -147
          >>> 4258 * x + 147 * y
          369

     (Contributed by Mark Dickinson in bpo-36027(15).)

   * Dict comprehensions have been synced-up with dict literals so that
     the key is computed first and the value second:

          >>> # Dict comprehension
          >>> cast = {input('role? '): input('actor? ') for i in range(2)}
          role? King Arthur
          actor? Chapman
          role? Black Knight
          actor? Cleese

          >>> # Dict literal
          >>> cast = {input('role? '): input('actor? ')}
          role? Sir Robin
          actor? Eric Idle

     The guaranteed execution order is helpful with assignment
     expressions because variables assigned in the key expression will
     be available in the value expression:

          >>> names = ['Martin von Löwis', 'Łukasz Langa', 'Walter Dörwald']
          >>> {(n := normalize('NFC', name)).casefold() : n for name in names}
          {'martin von löwis': 'Martin von Löwis',
           'łukasz langa': 'Łukasz Langa',
           'walter dörwald': 'Walter Dörwald'}

     (Contributed by Jörn Heissler in bpo-35224(16).)

   * The *note object.__reduce__(): bc8. method can now return a tuple
     from two to six elements long.  Formerly, five was the limit.  The
     new, optional sixth element is a callable with a ‘(obj, state)’
     signature.  This allows the direct control over the state-updating
     behavior of a specific object.  If not 'None', this callable will
     have priority over the object’s *note __setstate__(): bc9. method.
     (Contributed by Pierre Glaser and Olivier Grisel in bpo-35900(17).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32489

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33073

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37819

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20092

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30688

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33462

   (7) https://bugs.python.org/issue?@action=redirect&bpo=34641

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32117

   (9) https://bugs.python.org/issue?@action=redirect&bpo=15248

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32417

   (11) https://bugs.python.org/issue?@action=redirect&bpo=1054041

   (12) https://bugs.python.org/issue?@action=redirect&bpo=37032

   (13) https://en.wikipedia.org/wiki/Modular_multiplicative_inverse

   (14) https://en.wikipedia.org/wiki/Diophantine_equation

   (15) https://bugs.python.org/issue?@action=redirect&bpo=36027

   (16) https://bugs.python.org/issue?@action=redirect&bpo=35224

   (17) https://bugs.python.org/issue?@action=redirect&bpo=35900


File: python.info,  Node: New Modules<5>,  Next: Improved Modules<5>,  Prev: Other Language Changes<5>,  Up: What’s New In Python 3 8

1.7.4 New Modules
-----------------

   * The new *note importlib.metadata: 7e. module provides (provisional)
     support for reading metadata from third-party packages.  For
     example, it can extract an installed package’s version number, list
     of entry points, and more:

          >>> # Note following example requires that the popular "requests"
          >>> # package has been installed.
          >>>
          >>> from importlib.metadata import version, requires, files
          >>> version('requests')
          '2.22.0'
          >>> list(requires('requests'))
          ['chardet (<3.1.0,>=3.0.2)']
          >>> list(files('requests'))[:5]
          [PackagePath('requests-2.22.0.dist-info/INSTALLER'),
           PackagePath('requests-2.22.0.dist-info/LICENSE'),
           PackagePath('requests-2.22.0.dist-info/METADATA'),
           PackagePath('requests-2.22.0.dist-info/RECORD'),
           PackagePath('requests-2.22.0.dist-info/WHEEL')]

     (Contributed by Barry Warsaw and Jason R. Coombs in bpo-34632(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34632


File: python.info,  Node: Improved Modules<5>,  Next: Optimizations<6>,  Prev: New Modules<5>,  Up: What’s New In Python 3 8

1.7.5 Improved Modules
----------------------

* Menu:

* ast: ast<5>.
* asyncio: asyncio<9>.
* builtins: builtins<2>.
* collections::
* cProfile::
* csv: csv<2>.
* curses: curses<4>.
* ctypes: ctypes<3>.
* datetime: datetime<4>.
* functools: functools<3>.
* gc: gc<4>.
* gettext::
* gzip: gzip<3>.
* IDLE and idlelib: IDLE and idlelib<4>.
* inspect: inspect<6>.
* io: io<5>.
* itertools: itertools<5>.
* json.tool: json tool.
* logging: logging<2>.
* math: math<5>.
* mmap: mmap<2>.
* multiprocessing: multiprocessing<4>.
* os: os<7>.
* os.path: os path<5>.
* pathlib: pathlib<10>.
* pickle: pickle<2>.
* plistlib::
* pprint: pprint<3>.
* py_compile: py_compile<2>.
* shlex::
* shutil: shutil<4>.
* socket: socket<5>.
* ssl: ssl<5>.
* statistics: statistics<3>.
* sys: sys<7>.
* tarfile: tarfile<5>.
* threading: threading<5>.
* tokenize: tokenize<2>.
* tkinter: tkinter<5>.
* time: time<4>.
* typing: typing<9>.
* unicodedata: unicodedata<6>.
* unittest: unittest<7>.
* venv: venv<4>.
* weakref::
* xml: xml<4>.
* xmlrpc::


File: python.info,  Node: ast<5>,  Next: asyncio<9>,  Up: Improved Modules<5>

1.7.5.1 ast
...........

AST nodes now have ‘end_lineno’ and ‘end_col_offset’ attributes, which
give the precise location of the end of the node.  (This only applies to
nodes that have ‘lineno’ and ‘col_offset’ attributes.)

New function *note ast.get_source_segment(): bcd. returns the source
code for a specific AST node.

(Contributed by Ivan Levkivskyi in bpo-33416(1).)

The *note ast.parse(): 1c2. function has some new flags:

   * ‘type_comments=True’ causes it to return the text of PEP 484(2) and
     PEP 526(3) type comments associated with certain AST nodes;

   * ‘mode='func_type'’ can be used to parse PEP 484(4) «signature type
     comments» (returned for function definition AST nodes);

   * ‘feature_version=(3, N)’ allows specifying an earlier Python 3
     version.  For example, ‘feature_version=(3, 4)’ will treat *note
     async: 93c. and *note await: 18d. as non-reserved words.

(Contributed by Guido van Rossum in bpo-35766(5).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33416

   (2) https://peps.python.org/pep-0484/

   (3) https://peps.python.org/pep-0526/

   (4) https://peps.python.org/pep-0484/

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35766


File: python.info,  Node: asyncio<9>,  Next: builtins<2>,  Prev: ast<5>,  Up: Improved Modules<5>

1.7.5.2 asyncio
...............

*note asyncio.run(): 2f3. has graduated from the provisional to stable
API. This function can be used to execute a *note coroutine: 6ba. and
return the result while automatically managing the event loop.  For
example:

     import asyncio

     async def main():
         await asyncio.sleep(0)
         return 42

     asyncio.run(main())

This is 'roughly' equivalent to:

     import asyncio

     async def main():
         await asyncio.sleep(0)
         return 42

     loop = asyncio.new_event_loop()
     asyncio.set_event_loop(loop)
     try:
         loop.run_until_complete(main())
     finally:
         asyncio.set_event_loop(None)
         loop.close()

The actual implementation is significantly more complex.  Thus, *note
asyncio.run(): 2f3. should be the preferred way of running asyncio
programs.

(Contributed by Yury Selivanov in bpo-32314(1).)

Running ‘python -m asyncio’ launches a natively async REPL. This allows
rapid experimentation with code that has a top-level *note await: 18d.
There is no longer a need to directly call ‘asyncio.run()’ which would
spawn a new event loop on every invocation:

     $ python -m asyncio
     asyncio REPL 3.8.0
     Use "await" directly instead of "asyncio.run()".
     Type "help", "copyright", "credits" or "license" for more information.
     >>> import asyncio
     >>> await asyncio.sleep(10, result='hello')
     hello

(Contributed by Yury Selivanov in bpo-37028(2).)

The exception *note asyncio.CancelledError: 4d5. now inherits from *note
BaseException: 7d8. rather than *note Exception: bcf. and no longer
inherits from *note concurrent.futures.CancelledError: bd0.
(Contributed by Yury Selivanov in bpo-32528(3).)

On Windows, the default event loop is now *note ProactorEventLoop: 81e.
(Contributed by Victor Stinner in bpo-34687(4).)

*note ProactorEventLoop: 81e. now also supports UDP. (Contributed by
Adam Meily and Andrew Svetlov in bpo-29883(5).)

*note ProactorEventLoop: 81e. can now be interrupted by *note
KeyboardInterrupt: bc7. («CTRL+C»).  (Contributed by Vladimir Matveev in
bpo-23057(6).)

Added *note asyncio.Task.get_coro(): bd1. for getting the wrapped
coroutine within an *note asyncio.Task: 1c7.  (Contributed by Alex
Grönholm in bpo-36999(7).)

Asyncio tasks can now be named, either by passing the ‘name’ keyword
argument to *note asyncio.create_task(): 1c9. or the *note
create_task(): 1ca. event loop method, or by calling the *note
set_name(): bd2. method on the task object.  The task name is visible in
the ‘repr()’ output of *note asyncio.Task: 1c7. and can also be
retrieved using the *note get_name(): bd3. method.  (Contributed by Alex
Grönholm in bpo-34270(8).)

Added support for Happy Eyeballs(9) to *note
asyncio.loop.create_connection(): 819.  To specify the behavior, two new
parameters have been added: 'happy_eyeballs_delay' and 'interleave'.
The Happy Eyeballs algorithm improves responsiveness in applications
that support IPv4 and IPv6 by attempting to simultaneously connect using
both.  (Contributed by twisteroid ambassador in bpo-33530(10).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32314

   (2) https://bugs.python.org/issue?@action=redirect&bpo=37028

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32528

   (4) https://bugs.python.org/issue?@action=redirect&bpo=34687

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29883

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23057

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36999

   (8) https://bugs.python.org/issue?@action=redirect&bpo=34270

   (9) https://en.wikipedia.org/wiki/Happy_Eyeballs

   (10) https://bugs.python.org/issue?@action=redirect&bpo=33530


File: python.info,  Node: builtins<2>,  Next: collections,  Prev: asyncio<9>,  Up: Improved Modules<5>

1.7.5.3 builtins
................

The *note compile(): 4b2. built-in has been improved to accept the
‘ast.PyCF_ALLOW_TOP_LEVEL_AWAIT’ flag.  With this new flag passed, *note
compile(): 4b2. will allow top-level ‘await’, ‘async for’ and ‘async
with’ constructs that are usually considered invalid syntax.
Asynchronous code object marked with the ‘CO_COROUTINE’ flag may then be
returned.  (Contributed by Matthias Bussonnier in bpo-34616(1))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34616


File: python.info,  Node: collections,  Next: cProfile,  Prev: builtins<2>,  Up: Improved Modules<5>

1.7.5.4 collections
...................

The *note _asdict(): bd6. method for *note collections.namedtuple():
4e1. now returns a *note dict: 183. instead of a *note
collections.OrderedDict: 7f4.  This works because regular dicts have
guaranteed ordering since Python 3.7.  If the extra features of
‘OrderedDict’ are required, the suggested remediation is to cast the
result to the desired type: ‘OrderedDict(nt._asdict())’.  (Contributed
by Raymond Hettinger in bpo-35864(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35864


File: python.info,  Node: cProfile,  Next: csv<2>,  Prev: collections,  Up: Improved Modules<5>

1.7.5.5 cProfile
................

The *note cProfile.Profile: bd8. class can now be used as a context
manager.  Profile a block of code by running:

     import cProfile

     with cProfile.Profile() as profiler:
           # code to be profiled
           ...

(Contributed by Scott Sanderson in bpo-29235(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29235


File: python.info,  Node: csv<2>,  Next: curses<4>,  Prev: cProfile,  Up: Improved Modules<5>

1.7.5.6 csv
...........

The *note csv.DictReader: bda. now returns instances of *note dict: 183.
instead of a *note collections.OrderedDict: 7f4.  The tool is now faster
and uses less memory while still preserving the field order.
(Contributed by Michael Selik in bpo-34003(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34003


File: python.info,  Node: curses<4>,  Next: ctypes<3>,  Prev: csv<2>,  Up: Improved Modules<5>

1.7.5.7 curses
..............

Added a new variable holding structured version information for the
underlying ncurses library: *note ncurses_version: bdc.  (Contributed by
Serhiy Storchaka in bpo-31680(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31680


File: python.info,  Node: ctypes<3>,  Next: datetime<4>,  Prev: curses<4>,  Up: Improved Modules<5>

1.7.5.8 ctypes
..............

On Windows, *note CDLL: bde. and subclasses now accept a 'winmode'
parameter to specify flags for the underlying ‘LoadLibraryEx’ call.  The
default flags are set to only load DLL dependencies from trusted
locations, including the path where the DLL is stored (if a full or
partial path is used to load the initial DLL) and paths added by *note
add_dll_directory(): bdf.  (Contributed by Steve Dower in bpo-36085(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36085


File: python.info,  Node: datetime<4>,  Next: functools<3>,  Prev: ctypes<3>,  Up: Improved Modules<5>

1.7.5.9 datetime
................

Added new alternate constructors *note datetime.date.fromisocalendar():
be1. and *note datetime.datetime.fromisocalendar(): be2, which construct
*note date: 1fa. and *note datetime: 4e3. objects respectively from ISO
year, week number, and weekday; these are the inverse of each class’s
‘isocalendar’ method.  (Contributed by Paul Ganssle in bpo-36004(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36004


File: python.info,  Node: functools<3>,  Next: gc<4>,  Prev: datetime<4>,  Up: Improved Modules<5>

1.7.5.10 functools
..................

*note functools.lru_cache(): be4. can now be used as a straight
decorator rather than as a function returning a decorator.  So both of
these are now supported:

     @lru_cache
     def f(x):
         ...

     @lru_cache(maxsize=256)
     def f(x):
         ...

(Contributed by Raymond Hettinger in bpo-36772(1).)

Added a new *note functools.cached_property(): 764. decorator, for
computed properties cached for the life of the instance.

     import functools
     import statistics

     class Dataset:
        def __init__(self, sequence_of_numbers):
           self.data = sequence_of_numbers

        @functools.cached_property
        def variance(self):
           return statistics.variance(self.data)

(Contributed by Carl Meyer in bpo-21145(2))

Added a new *note functools.singledispatchmethod(): be5. decorator that
converts methods into *note generic functions: be6. using *note single
dispatch: be7.:

     from functools import singledispatchmethod
     from contextlib import suppress

     class TaskManager:

         def __init__(self, tasks):
             self.tasks = list(tasks)

         @singledispatchmethod
         def discard(self, value):
             with suppress(ValueError):
                 self.tasks.remove(value)

         @discard.register(list)
         def _(self, tasks):
             targets = set(tasks)
             self.tasks = [x for x in self.tasks if x not in targets]

(Contributed by Ethan Smith in bpo-32380(3))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36772

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21145

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32380


File: python.info,  Node: gc<4>,  Next: gettext,  Prev: functools<3>,  Up: Improved Modules<5>

1.7.5.11 gc
...........

*note get_objects(): a06. can now receive an optional 'generation'
parameter indicating a generation to get objects from.  (Contributed by
Pablo Galindo in bpo-36016(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36016


File: python.info,  Node: gettext,  Next: gzip<3>,  Prev: gc<4>,  Up: Improved Modules<5>

1.7.5.12 gettext
................

Added *note pgettext(): bea. and its variants.  (Contributed by Franz
Glasner, Éric Araujo, and Cheryl Sabella in bpo-2504(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=2504


File: python.info,  Node: gzip<3>,  Next: IDLE and idlelib<4>,  Prev: gettext,  Up: Improved Modules<5>

1.7.5.13 gzip
.............

Added the 'mtime' parameter to *note gzip.compress(): 84f. for
reproducible output.  (Contributed by Guo Ci Teo in bpo-34898(1).)

A *note BadGzipFile: bec. exception is now raised instead of *note
OSError: 2c0. for certain types of invalid or corrupt gzip files.
(Contributed by Filip Gruszczyński, Michele Orrù, and Zackery Spytz in
bpo-6584(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34898

   (2) https://bugs.python.org/issue?@action=redirect&bpo=6584


File: python.info,  Node: IDLE and idlelib<4>,  Next: inspect<6>,  Prev: gzip<3>,  Up: Improved Modules<5>

1.7.5.14 IDLE and idlelib
.........................

Output over N lines (50 by default) is squeezed down to a button.  N can
be changed in the PyShell section of the General page of the Settings
dialog.  Fewer, but possibly extra long, lines can be squeezed by right
clicking on the output.  Squeezed output can be expanded in place by
double-clicking the button or into the clipboard or a separate window by
right-clicking the button.  (Contributed by Tal Einat in
bpo-1529353(1).)

Add «Run Customized» to the Run menu to run a module with customized
settings.  Any command line arguments entered are added to sys.argv.
They also re-appear in the box for the next customized run.  One can
also suppress the normal Shell main module restart.  (Contributed by
Cheryl Sabella, Terry Jan Reedy, and others in bpo-5680(2) and
bpo-37627(3).)

Added optional line numbers for IDLE editor windows.  Windows open
without line numbers unless set otherwise in the General tab of the
configuration dialog.  Line numbers for an existing window are shown and
hidden in the Options menu.  (Contributed by Tal Einat and Saimadhav
Heblikar in bpo-17535(4).)

OS native encoding is now used for converting between Python strings and
Tcl objects.  This allows IDLE to work with emoji and other non-BMP
characters.  These characters can be displayed or copied and pasted to
or from the clipboard.  Converting strings from Tcl to Python and back
now never fails.  (Many people worked on this for eight years but the
problem was finally solved by Serhiy Storchaka in bpo-13153(5).)

New in 3.8.1:

Add option to toggle cursor blink off.  (Contributed by Zackery Spytz in
bpo-4603(6).)

Escape key now closes IDLE completion windows.  (Contributed by Johnny
Najera in bpo-38944(7).)

The changes above have been backported to 3.7 maintenance releases.

Add keywords to module name completion list.  (Contributed by Terry J.
Reedy in bpo-37765(8).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1529353

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5680

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37627

   (4) https://bugs.python.org/issue?@action=redirect&bpo=17535

   (5) https://bugs.python.org/issue?@action=redirect&bpo=13153

   (6) https://bugs.python.org/issue?@action=redirect&bpo=4603

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38944

   (8) https://bugs.python.org/issue?@action=redirect&bpo=37765


File: python.info,  Node: inspect<6>,  Next: io<5>,  Prev: IDLE and idlelib<4>,  Up: Improved Modules<5>

1.7.5.15 inspect
................

The *note inspect.getdoc(): bef. function can now find docstrings for
‘__slots__’ if that attribute is a *note dict: 183. where the values are
docstrings.  This provides documentation options similar to what we
already have for *note property(): 4b4, *note classmethod(): 48f, and
*note staticmethod(): 453.:

     class AudioClip:
         __slots__ = {'bit_rate': 'expressed in kilohertz to one decimal place',
                      'duration': 'in seconds, rounded up to an integer'}
         def __init__(self, bit_rate, duration):
             self.bit_rate = round(bit_rate / 1000.0, 1)
             self.duration = ceil(duration)

(Contributed by Raymond Hettinger in bpo-36326(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36326


File: python.info,  Node: io<5>,  Next: itertools<5>,  Prev: inspect<6>,  Up: Improved Modules<5>

1.7.5.16 io
...........

In development mode (*note -X: 16f. ‘env’) and in *note debug build:
50a, the *note io.IOBase: 506. finalizer now logs the exception if the
‘close()’ method fails.  The exception is ignored silently by default in
release build.  (Contributed by Victor Stinner in bpo-18748(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18748


File: python.info,  Node: itertools<5>,  Next: json tool,  Prev: io<5>,  Up: Improved Modules<5>

1.7.5.17 itertools
..................

The *note itertools.accumulate(): bf2. function added an option
'initial' keyword argument to specify an initial value:

     >>> from itertools import accumulate
     >>> list(accumulate([10, 5, 30, 15], initial=1000))
     [1000, 1010, 1015, 1045, 1060]

(Contributed by Lisa Roach in bpo-34659(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34659


File: python.info,  Node: json tool,  Next: logging<2>,  Prev: itertools<5>,  Up: Improved Modules<5>

1.7.5.18 json.tool
..................

Add option ‘--json-lines’ to parse every input line as a separate JSON
object.  (Contributed by Weipeng Hong in bpo-31553(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31553


File: python.info,  Node: logging<2>,  Next: math<5>,  Prev: json tool,  Up: Improved Modules<5>

1.7.5.19 logging
................

Added a 'force' keyword argument to *note logging.basicConfig(): bf5.
When set to true, any existing handlers attached to the root logger are
removed and closed before carrying out the configuration specified by
the other arguments.

This solves a long-standing problem.  Once a logger or 'basicConfig()'
had been called, subsequent calls to 'basicConfig()' were silently
ignored.  This made it difficult to update, experiment with, or teach
the various logging configuration options using the interactive prompt
or a Jupyter notebook.

(Suggested by Raymond Hettinger, implemented by Donghee Na, and reviewed
by Vinay Sajip in bpo-33897(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33897


File: python.info,  Node: math<5>,  Next: mmap<2>,  Prev: logging<2>,  Up: Improved Modules<5>

1.7.5.20 math
.............

Added new function *note math.dist(): bf7. for computing Euclidean
distance between two points.  (Contributed by Raymond Hettinger in
bpo-33089(1).)

Expanded the *note math.hypot(): bf8. function to handle multiple
dimensions.  Formerly, it only supported the 2-D case.  (Contributed by
Raymond Hettinger in bpo-33089(2).)

Added new function, *note math.prod(): bf9, as analogous function to
*note sum(): 696. that returns the product of a “start” value (default:
1) times an iterable of numbers:

     >>> prior = 0.8
     >>> likelihoods = [0.625, 0.84, 0.30]
     >>> math.prod(likelihoods, start=prior)
     0.126

(Contributed by Pablo Galindo in bpo-35606(3).)

Added two new combinatoric functions *note math.perm(): 8e1. and *note
math.comb(): 8e0.:

     >>> math.perm(10, 3)    # Permutations of 10 things taken 3 at a time
     720
     >>> math.comb(10, 3)    # Combinations of 10 things taken 3 at a time
     120

(Contributed by Yash Aggarwal, Keller Fuchs, Serhiy Storchaka, and
Raymond Hettinger in bpo-37128(4), bpo-37178(5), and bpo-35431(6).)

Added a new function *note math.isqrt(): bfa. for computing accurate
integer square roots without conversion to floating point.  The new
function supports arbitrarily large integers.  It is faster than
‘floor(sqrt(n))’ but slower than *note math.sqrt(): bfb.:

     >>> r = 650320427
     >>> s = r ** 2
     >>> isqrt(s - 1)         # correct
     650320426
     >>> floor(sqrt(s - 1))   # incorrect
     650320427

(Contributed by Mark Dickinson in bpo-36887(7).)

The function *note math.factorial(): b43. no longer accepts arguments
that are not int-like.  (Contributed by Pablo Galindo in bpo-33083(8).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33089

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33089

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35606

   (4) https://bugs.python.org/issue?@action=redirect&bpo=37128

   (5) https://bugs.python.org/issue?@action=redirect&bpo=37178

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35431

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36887

   (8) https://bugs.python.org/issue?@action=redirect&bpo=33083


File: python.info,  Node: mmap<2>,  Next: multiprocessing<4>,  Prev: math<5>,  Up: Improved Modules<5>

1.7.5.21 mmap
.............

The *note mmap.mmap: 51a. class now has an *note madvise(): bfd. method
to access the ‘madvise()’ system call.  (Contributed by Zackery Spytz in
bpo-32941(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32941


File: python.info,  Node: multiprocessing<4>,  Next: os<7>,  Prev: mmap<2>,  Up: Improved Modules<5>

1.7.5.22 multiprocessing
........................

Added new *note multiprocessing.shared_memory: 9d. module.  (Contributed
by Davin Potts in bpo-35813(1).)

On macOS, the 'spawn' start method is now used by default.  (Contributed
by Victor Stinner in bpo-33725(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35813

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33725


File: python.info,  Node: os<7>,  Next: os path<5>,  Prev: multiprocessing<4>,  Up: Improved Modules<5>

1.7.5.23 os
...........

Added new function *note add_dll_directory(): bdf. on Windows for
providing additional search paths for native dependencies when importing
extension modules or loading DLLs using *note ctypes: 2e.  (Contributed
by Steve Dower in bpo-36085(1).)

A new *note os.memfd_create(): c00. function was added to wrap the
‘memfd_create()’ syscall.  (Contributed by Zackery Spytz and Christian
Heimes in bpo-26836(2).)

On Windows, much of the manual logic for handling reparse points
(including symlinks and directory junctions) has been delegated to the
operating system.  Specifically, *note os.stat(): 26d. will now traverse
anything supported by the operating system, while *note os.lstat(): 6c9.
will only open reparse points that identify as «name surrogates» while
others are opened as for *note os.stat(): 26d.  In all cases, *note
os.stat_result.st_mode: c01. will only have ‘S_IFLNK’ set for symbolic
links and not other kinds of reparse points.  To identify other kinds of
reparse point, check the new *note os.stat_result.st_reparse_tag: c02.
attribute.

On Windows, *note os.readlink(): b1c. is now able to read directory
junctions.  Note that *note islink(): c03. will return ‘False’ for
directory junctions, and so code that checks ‘islink’ first will
continue to treat junctions as directories, while code that handles
errors from *note os.readlink(): b1c. may now treat junctions as links.

(Contributed by Steve Dower in bpo-37834(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36085

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26836

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37834


File: python.info,  Node: os path<5>,  Next: pathlib<10>,  Prev: os<7>,  Up: Improved Modules<5>

1.7.5.24 os.path
................

*note os.path: a6. functions that return a boolean result like *note
exists(): c05, *note lexists(): c06, *note isdir(): c07, *note isfile():
c08, *note islink(): c03, and *note ismount(): c09. now return ‘False’
instead of raising *note ValueError: 2ec. or its subclasses *note
UnicodeEncodeError: 888. and *note UnicodeDecodeError: c0a. for paths
that contain characters or bytes unrepresentable at the OS level.
(Contributed by Serhiy Storchaka in bpo-33721(1).)

*note expanduser(): c0b. on Windows now prefers the ‘USERPROFILE’
environment variable and does not use ‘HOME’, which is not normally set
for regular user accounts.  (Contributed by Anthony Sottile in
bpo-36264(2).)

*note isdir(): c07. on Windows no longer returns ‘True’ for a link to a
non-existent directory.

*note realpath(): 262. on Windows now resolves reparse points, including
symlinks and directory junctions.

(Contributed by Steve Dower in bpo-37834(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33721

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36264

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37834


File: python.info,  Node: pathlib<10>,  Next: pickle<2>,  Prev: os path<5>,  Up: Improved Modules<5>

1.7.5.25 pathlib
................

*note pathlib.Path: 266. methods that return a boolean result like *note
exists(): c0d, *note is_dir(): 53b, *note is_file(): 53a, *note
is_mount(): c0e, *note is_symlink(): c0f, *note is_block_device(): c10,
*note is_char_device(): c11, *note is_fifo(): c12, *note is_socket():
c13. now return ‘False’ instead of raising *note ValueError: 2ec. or its
subclass *note UnicodeEncodeError: 888. for paths that contain
characters unrepresentable at the OS level.  (Contributed by Serhiy
Storchaka in bpo-33721(1).)

Added ‘pathlib.Path.link_to()’ which creates a hard link pointing to a
path.  (Contributed by Joannah Nanjekye in bpo-26978(2)) Note that
‘link_to’ was deprecated in 3.10 and removed in 3.12 in favor of a
‘hardlink_to’ method added in 3.10 which matches the semantics of the
existing ‘symlink_to’ method.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33721

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26978


File: python.info,  Node: pickle<2>,  Next: plistlib,  Prev: pathlib<10>,  Up: Improved Modules<5>

1.7.5.26 pickle
...............

*note pickle: ab. extensions subclassing the C-optimized *note Pickler:
c15. can now override the pickling logic of functions and classes by
defining the special *note reducer_override(): c16. method.
(Contributed by Pierre Glaser and Olivier Grisel in bpo-35900(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35900


File: python.info,  Node: plistlib,  Next: pprint<3>,  Prev: pickle<2>,  Up: Improved Modules<5>

1.7.5.27 plistlib
.................

Added new *note plistlib.UID: c18. and enabled support for reading and
writing NSKeyedArchiver-encoded binary plists.  (Contributed by Jon
Janzen in bpo-26707(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26707


File: python.info,  Node: pprint<3>,  Next: py_compile<2>,  Prev: plistlib,  Up: Improved Modules<5>

1.7.5.28 pprint
...............

The *note pprint: b3. module added a 'sort_dicts' parameter to several
functions.  By default, those functions continue to sort dictionaries
before rendering or printing.  However, if 'sort_dicts' is set to false,
the dictionaries retain the order that keys were inserted.  This can be
useful for comparison to JSON inputs during debugging.

In addition, there is a convenience new function, *note pprint.pp():
c1a. that is like *note pprint.pprint(): a2b. but with 'sort_dicts'
defaulting to ‘False’:

     >>> from pprint import pprint, pp
     >>> d = dict(source='input.txt', operation='filter', destination='output.txt')
     >>> pp(d, width=40)                  # Original order
     {'source': 'input.txt',
      'operation': 'filter',
      'destination': 'output.txt'}
     >>> pprint(d, width=40)              # Keys sorted alphabetically
     {'destination': 'output.txt',
      'operation': 'filter',
      'source': 'input.txt'}

(Contributed by Rémi Lapeyre in bpo-30670(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30670


File: python.info,  Node: py_compile<2>,  Next: shlex,  Prev: pprint<3>,  Up: Improved Modules<5>

1.7.5.29 py_compile
...................

*note py_compile.compile(): c1c. now supports silent mode.  (Contributed
by Joannah Nanjekye in bpo-22640(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22640


File: python.info,  Node: shlex,  Next: shutil<4>,  Prev: py_compile<2>,  Up: Improved Modules<5>

1.7.5.30 shlex
..............

The new *note shlex.join(): c1e. function acts as the inverse of *note
shlex.split(): 75f.  (Contributed by Bo Bayles in bpo-32102(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32102


File: python.info,  Node: shutil<4>,  Next: socket<5>,  Prev: shlex,  Up: Improved Modules<5>

1.7.5.31 shutil
...............

*note shutil.copytree(): c20. now accepts a new ‘dirs_exist_ok’ keyword
argument.  (Contributed by Josh Bronson in bpo-20849(1).)

*note shutil.make_archive(): 6db. now defaults to the modern pax
(POSIX.1-2001) format for new archives to improve portability and
standards conformance, inherited from the corresponding change to the
*note tarfile: e4. module.  (Contributed by C.A.M. Gerlach in
bpo-30661(2).)

*note shutil.rmtree(): 356. on Windows now removes directory junctions
without recursively removing their contents first.  (Contributed by
Steve Dower in bpo-37834(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20849

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30661

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37834


File: python.info,  Node: socket<5>,  Next: ssl<5>,  Prev: shutil<4>,  Up: Improved Modules<5>

1.7.5.32 socket
...............

Added *note create_server(): c22. and *note has_dualstack_ipv6(): c23.
convenience functions to automate the necessary tasks usually involved
when creating a server socket, including accepting both IPv4 and IPv6
connections on the same socket.  (Contributed by Giampaolo Rodolà in
bpo-17561(1).)

The *note socket.if_nameindex(): c24, *note socket.if_nametoindex():
c25, and *note socket.if_indextoname(): c26. functions have been
implemented on Windows.  (Contributed by Zackery Spytz in bpo-37007(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17561

   (2) https://bugs.python.org/issue?@action=redirect&bpo=37007


File: python.info,  Node: ssl<5>,  Next: statistics<3>,  Prev: socket<5>,  Up: Improved Modules<5>

1.7.5.33 ssl
............

Added *note post_handshake_auth: c28. to enable and *note
verify_client_post_handshake(): c29. to initiate TLS 1.3 post-handshake
authentication.  (Contributed by Christian Heimes in bpo-34670(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34670


File: python.info,  Node: statistics<3>,  Next: sys<7>,  Prev: ssl<5>,  Up: Improved Modules<5>

1.7.5.34 statistics
...................

Added *note statistics.fmean(): c2b. as a faster, floating-point variant
of *note statistics.mean(): 8e2.  (Contributed by Raymond Hettinger and
Steven D’Aprano in bpo-35904(1).)

Added *note statistics.geometric_mean(): c2c. (Contributed by Raymond
Hettinger in bpo-27181(2).)

Added *note statistics.multimode(): c2d. that returns a list of the most
common values.  (Contributed by Raymond Hettinger in bpo-35892(3).)

Added *note statistics.quantiles(): c2e. that divides data or a
distribution in to equiprobable intervals (e.g.  quartiles, deciles, or
percentiles).  (Contributed by Raymond Hettinger in bpo-36546(4).)

Added *note statistics.NormalDist: c2f, a tool for creating and
manipulating normal distributions of a random variable.  (Contributed by
Raymond Hettinger in bpo-36018(5).)

     >>> temperature_feb = NormalDist.from_samples([4, 12, -3, 2, 7, 14])
     >>> temperature_feb.mean
     6.0
     >>> temperature_feb.stdev
     6.356099432828281

     >>> temperature_feb.cdf(3)            # Chance of being under 3 degrees
     0.3184678262814532
     >>> # Relative chance of being 7 degrees versus 10 degrees
     >>> temperature_feb.pdf(7) / temperature_feb.pdf(10)
     1.2039930378537762

     >>> el_niño = NormalDist(4, 2.5)
     >>> temperature_feb += el_niño        # Add in a climate effect
     >>> temperature_feb
     NormalDist(mu=10.0, sigma=6.830080526611674)

     >>> temperature_feb * (9/5) + 32      # Convert to Fahrenheit
     NormalDist(mu=50.0, sigma=12.294144947901014)
     >>> temperature_feb.samples(3)        # Generate random samples
     [7.672102882379219, 12.000027119750287, 4.647488369766392]

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35904

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27181

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35892

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36546

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36018


File: python.info,  Node: sys<7>,  Next: tarfile<5>,  Prev: statistics<3>,  Up: Improved Modules<5>

1.7.5.35 sys
............

Add new *note sys.unraisablehook(): 508. function which can be
overridden to control how «unraisable exceptions» are handled.  It is
called when an exception has occurred but there is no way for Python to
handle it.  For example, when a destructor raises an exception or during
garbage collection (*note gc.collect(): 1b3.).  (Contributed by Victor
Stinner in bpo-36829(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36829


File: python.info,  Node: tarfile<5>,  Next: threading<5>,  Prev: sys<7>,  Up: Improved Modules<5>

1.7.5.36 tarfile
................

The *note tarfile: e4. module now defaults to the modern pax
(POSIX.1-2001) format for new archives, instead of the previous
GNU-specific one.  This improves cross-platform portability with a
consistent encoding (UTF-8) in a standardized and extensible format, and
offers several other benefits.  (Contributed by C.A.M. Gerlach in
bpo-36268(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36268


File: python.info,  Node: threading<5>,  Next: tokenize<2>,  Prev: tarfile<5>,  Up: Improved Modules<5>

1.7.5.37 threading
..................

Add a new *note threading.excepthook(): a4d. function which handles
uncaught *note threading.Thread.run(): c33. exception.  It can be
overridden to control how uncaught *note threading.Thread.run(): c33.
exceptions are handled.  (Contributed by Victor Stinner in
bpo-1230540(1).)

Add a new *note threading.get_native_id(): c34. function and a *note
native_id: c35. attribute to the *note threading.Thread: 176. class.
These return the native integral Thread ID of the current thread
assigned by the kernel.  This feature is only available on certain
platforms, see *note get_native_id: c34. for more information.
(Contributed by Jake Tesler in bpo-36084(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1230540

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36084


File: python.info,  Node: tokenize<2>,  Next: tkinter<5>,  Prev: threading<5>,  Up: Improved Modules<5>

1.7.5.38 tokenize
.................

The *note tokenize: 101. module now implicitly emits a ‘NEWLINE’ token
when provided with input that does not have a trailing new line.  This
behavior now matches what the C tokenizer does internally.  (Contributed
by Ammar Askar in bpo-33899(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33899


File: python.info,  Node: tkinter<5>,  Next: time<4>,  Prev: tokenize<2>,  Up: Improved Modules<5>

1.7.5.39 tkinter
................

Added methods ‘selection_from()’, ‘selection_present()’,
‘selection_range()’ and ‘selection_to()’ in the ‘tkinter.Spinbox’ class.
(Contributed by Juliette Monsel in bpo-34829(1).)

Added method ‘moveto()’ in the ‘tkinter.Canvas’ class.  (Contributed by
Juliette Monsel in bpo-23831(2).)

The ‘tkinter.PhotoImage’ class now has ‘transparency_get()’ and
‘transparency_set()’ methods.  (Contributed by Zackery Spytz in
bpo-25451(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34829

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23831

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25451


File: python.info,  Node: time<4>,  Next: typing<9>,  Prev: tkinter<5>,  Up: Improved Modules<5>

1.7.5.40 time
.............

Added new clock *note CLOCK_UPTIME_RAW: c39. for macOS 10.12.
(Contributed by Joannah Nanjekye in bpo-35702(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35702


File: python.info,  Node: typing<9>,  Next: unicodedata<6>,  Prev: time<4>,  Up: Improved Modules<5>

1.7.5.41 typing
...............

The *note typing: 10a. module incorporates several new features:

   * A dictionary type with per-key types.  See PEP 589(1) and *note
     typing.TypedDict: 332.  TypedDict uses only string keys.  By
     default, every key is required to be present.  Specify
     «total=False» to allow keys to be optional:

          class Location(TypedDict, total=False):
              lat_long: tuple
              grid_square: str
              xy_coordinate: tuple

   * Literal types.  See PEP 586(2) and *note typing.Literal: a57.
     Literal types indicate that a parameter or return value is
     constrained to one or more specific literal values:

          def get_status(port: int) -> Literal['connected', 'disconnected']:
              ...

   * «Final» variables, functions, methods and classes.  See PEP 591(3),
     *note typing.Final: 56e. and *note typing.final(): 8bd.  The final
     qualifier instructs a static type checker to restrict subclassing,
     overriding, or reassignment:

          pi: Final[float] = 3.1415926536

   * Protocol definitions.  See PEP 544(4), *note typing.Protocol: 56b.
     and *note typing.runtime_checkable(): 675.  Simple ABCs like *note
     typing.SupportsInt: c3b. are now ‘Protocol’ subclasses.

   * New protocol class *note typing.SupportsIndex: c3c.

   * New functions *note typing.get_origin(): 2ab. and *note
     typing.get_args(): 2ac.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0589/

   (2) https://peps.python.org/pep-0586/

   (3) https://peps.python.org/pep-0591/

   (4) https://peps.python.org/pep-0544/


File: python.info,  Node: unicodedata<6>,  Next: unittest<7>,  Prev: typing<9>,  Up: Improved Modules<5>

1.7.5.42 unicodedata
....................

The *note unicodedata: 10b. module has been upgraded to use the Unicode
12.1.0(1) release.

New function *note is_normalized(): c3e. can be used to verify a string
is in a specific normal form, often much faster than by actually
normalizing the string.  (Contributed by Max Belanger, David Euresti,
and Greg Price in bpo-32285(2) and bpo-37966(3)).

   ---------- Footnotes ----------

   (1) https://blog.unicode.org/2019/05/unicode-12-1-en.html

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32285

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37966


File: python.info,  Node: unittest<7>,  Next: venv<4>,  Prev: unicodedata<6>,  Up: Improved Modules<5>

1.7.5.43 unittest
.................

Added *note AsyncMock: c40. to support an asynchronous version of *note
Mock: c41.  Appropriate new assert functions for testing have been added
as well.  (Contributed by Lisa Roach in bpo-26467(1)).

Added *note addModuleCleanup(): c42. and *note addClassCleanup(): c43.
to unittest to support cleanups for *note setUpModule(): c44. and *note
setUpClass(): c45.  (Contributed by Lisa Roach in bpo-24412(2).)

Several mock assert functions now also print a list of actual calls upon
failure.  (Contributed by Petter Strandmark in bpo-35047(3).)

*note unittest: 10c. module gained support for coroutines to be used as
test cases with *note unittest.IsolatedAsyncioTestCase: 361.
(Contributed by Andrew Svetlov in bpo-32972(4).)

Example:

     import unittest


     class TestRequest(unittest.IsolatedAsyncioTestCase):

         async def asyncSetUp(self):
             self.connection = await AsyncConnection()

         async def test_get(self):
             response = await self.connection.get("https://example.com")
             self.assertEqual(response.status_code, 200)

         async def asyncTearDown(self):
             await self.connection.close()


     if __name__ == "__main__":
         unittest.main()

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26467

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24412

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35047

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32972


File: python.info,  Node: venv<4>,  Next: weakref,  Prev: unittest<7>,  Up: Improved Modules<5>

1.7.5.44 venv
.............

*note venv: 117. now includes an ‘Activate.ps1’ script on all platforms
for activating virtual environments under PowerShell Core 6.1.
(Contributed by Brett Cannon in bpo-32718(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32718


File: python.info,  Node: weakref,  Next: xml<4>,  Prev: venv<4>,  Up: Improved Modules<5>

1.7.5.45 weakref
................

The proxy objects returned by *note weakref.proxy(): c48. now support
the matrix multiplication operators ‘@’ and ‘@=’ in addition to the
other numeric operators.  (Contributed by Mark Dickinson in
bpo-36669(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36669


File: python.info,  Node: xml<4>,  Next: xmlrpc,  Prev: weakref,  Up: Improved Modules<5>

1.7.5.46 xml
............

As mitigation against DTD and external entity retrieval, the *note
xml.dom.minidom: 128. and *note xml.sax: 12f. modules no longer process
external entities by default.  (Contributed by Christian Heimes in
bpo-17239(1).)

The ‘.find*()’ methods in the *note xml.etree.ElementTree: 12b. module
support wildcard searches like ‘{*}tag’ which ignores the namespace and
‘{namespace}*’ which returns all tags in the given namespace.
(Contributed by Stefan Behnel in bpo-28238(2).)

The *note xml.etree.ElementTree: 12b. module provides a new function
*note canonicalize(): c4a. that implements C14N 2.0.  (Contributed by
Stefan Behnel in bpo-13611(3).)

The target object of *note xml.etree.ElementTree.XMLParser: c4b. can
receive namespace declaration events through the new callback methods
‘start_ns()’ and ‘end_ns()’.  Additionally, the *note
xml.etree.ElementTree.TreeBuilder: c4c. target can be configured to
process events about comments and processing instructions to include
them in the generated tree.  (Contributed by Stefan Behnel in
bpo-36676(4) and bpo-36673(5).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17239

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28238

   (3) https://bugs.python.org/issue?@action=redirect&bpo=13611

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36676

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36673


File: python.info,  Node: xmlrpc,  Prev: xml<4>,  Up: Improved Modules<5>

1.7.5.47 xmlrpc
...............

*note xmlrpc.client.ServerProxy: c4e. now supports an optional 'headers'
keyword argument for a sequence of HTTP headers to be sent with each
request.  Among other things, this makes it possible to upgrade from
default basic authentication to faster session authentication.
(Contributed by Cédric Krier in bpo-35153(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35153


File: python.info,  Node: Optimizations<6>,  Next: Build and C API Changes,  Prev: Improved Modules<5>,  Up: What’s New In Python 3 8

1.7.6 Optimizations
-------------------

   * The *note subprocess: dc. module can now use the *note
     os.posix_spawn(): 52f. function in some cases for better
     performance.  Currently, it is only used on macOS and Linux (using
     glibc 2.24 or newer) if all these conditions are met:

        * 'close_fds' is false;

        * 'preexec_fn', 'pass_fds', 'cwd' and 'start_new_session'
          parameters are not set;

        * the 'executable' path contains a directory.

     (Contributed by Joannah Nanjekye and Victor Stinner in
     bpo-35537(1).)

   * *note shutil.copyfile(): c50, *note shutil.copy(): c51, *note
     shutil.copy2(): c52, *note shutil.copytree(): c20. and *note
     shutil.move(): c53. use platform-specific «fast-copy» syscalls on
     Linux and macOS in order to copy the file more efficiently.
     «fast-copy» means that the copying operation occurs within the
     kernel, avoiding the use of userspace buffers in Python as in
     «‘outfd.write(infd.read())’».  On Windows *note shutil.copyfile():
     c50. uses a bigger default buffer size (1 MiB instead of 16 KiB)
     and a *note memoryview(): 165.-based variant of *note
     shutil.copyfileobj(): c54. is used.  The speedup for copying a 512
     MiB file within the same partition is about +26% on Linux, +50% on
     macOS and +40% on Windows.  Also, much less CPU cycles are
     consumed.  See *note Platform-dependent efficient copy operations:
     c55. section.  (Contributed by Giampaolo Rodolà in bpo-33671(2).)

   * *note shutil.copytree(): c20. uses *note os.scandir(): c56.
     function and all copy functions depending from it use cached *note
     os.stat(): 26d. values.  The speedup for copying a directory with
     8000 files is around +9% on Linux, +20% on Windows and +30% on a
     Windows SMB share.  Also the number of *note os.stat(): 26d.
     syscalls is reduced by 38% making *note shutil.copytree(): c20.
     especially faster on network filesystems.  (Contributed by
     Giampaolo Rodolà in bpo-33695(3).)

   * The default protocol in the *note pickle: ab. module is now
     Protocol 4, first introduced in Python 3.4.  It offers better
     performance and smaller size compared to Protocol 3 available since
     Python 3.0.

   * Removed one *note Py_ssize_t: c57. member from ‘PyGC_Head’.  All GC
     tracked objects (e.g.  tuple, list, dict) size is reduced 4 or 8
     bytes.  (Contributed by Inada Naoki in bpo-33597(4).)

   * *note uuid.UUID: c58. now uses ‘__slots__’ to reduce its memory
     footprint.  (Contributed by Wouter Bolsterlee and Tal Einat in
     bpo-30977(5))

   * Improved performance of *note operator.itemgetter(): c59. by 33%.
     Optimized argument handling and added a fast path for the common
     case of a single non-negative integer index into a tuple (which is
     the typical use case in the standard library).  (Contributed by
     Raymond Hettinger in bpo-35664(6).)

   * Sped-up field lookups in *note collections.namedtuple(): 4e1.  They
     are now more than two times faster, making them the fastest form of
     instance variable lookup in Python.  (Contributed by Raymond
     Hettinger, Pablo Galindo, and Joe Jevnik, Serhiy Storchaka in
     bpo-32492(7).)

   * The *note list: 24d. constructor does not overallocate the internal
     item buffer if the input iterable has a known length (the input
     implements ‘__len__’).  This makes the created list 12% smaller on
     average.  (Contributed by Raymond Hettinger and Pablo Galindo in
     bpo-33234(8).)

   * Doubled the speed of class variable writes.  When a non-dunder
     attribute was updated, there was an unnecessary call to update
     slots.  (Contributed by Stefan Behnel, Pablo Galindo Salgado,
     Raymond Hettinger, Neil Schemenauer, and Serhiy Storchaka in
     bpo-36012(9).)

   * Reduced an overhead of converting arguments passed to many builtin
     functions and methods.  This sped up calling some simple builtin
     functions and methods up to 20–50%.  (Contributed by Serhiy
     Storchaka in bpo-23867(10), bpo-35582(11) and bpo-36127(12).)

   * ‘LOAD_GLOBAL’ instruction now uses new «per opcode cache»
     mechanism.  It is about 40% faster now.  (Contributed by Yury
     Selivanov and Inada Naoki in bpo-26219(13).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35537

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33671

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33695

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33597

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30977

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35664

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32492

   (8) https://bugs.python.org/issue?@action=redirect&bpo=33234

   (9) https://bugs.python.org/issue?@action=redirect&bpo=36012

   (10) https://bugs.python.org/issue?@action=redirect&bpo=23867

   (11) https://bugs.python.org/issue?@action=redirect&bpo=35582

   (12) https://bugs.python.org/issue?@action=redirect&bpo=36127

   (13) https://bugs.python.org/issue?@action=redirect&bpo=26219


File: python.info,  Node: Build and C API Changes,  Next: Deprecated<7>,  Prev: Optimizations<6>,  Up: What’s New In Python 3 8

1.7.7 Build and C API Changes
-----------------------------

   * Default *note sys.abiflags: c5b. became an empty string: the ‘m’
     flag for pymalloc became useless (builds with and without pymalloc
     are ABI compatible) and so has been removed.  (Contributed by
     Victor Stinner in bpo-36707(1).)

     Example of changes:

        * Only ‘python3.8’ program is installed, ‘python3.8m’ program is
          gone.

        * Only ‘python3.8-config’ script is installed,
          ‘python3.8m-config’ script is gone.

        * The ‘m’ flag has been removed from the suffix of dynamic
          library filenames: extension modules in the standard library
          as well as those produced and installed by third-party
          packages, like those downloaded from PyPI. On Linux, for
          example, the Python 3.7 suffix
          ‘.cpython-37m-x86_64-linux-gnu.so’ became
          ‘.cpython-38-x86_64-linux-gnu.so’ in Python 3.8.

   * The header files have been reorganized to better separate the
     different kinds of APIs:

        * ‘Include/*.h’ should be the portable public stable C API.

        * ‘Include/cpython/*.h’ should be the unstable C API specific to
          CPython; public API, with some private API prefixed by ‘_Py’
          or ‘_PY’.

        * ‘Include/internal/*.h’ is the private internal C API very
          specific to CPython.  This API comes with no backward
          compatibility warranty and should not be used outside CPython.
          It is only exposed for very specific needs like debuggers and
          profiles which has to access to CPython internals without
          calling functions.  This API is now installed by ‘make
          install’.

     (Contributed by Victor Stinner in bpo-35134(2) and bpo-35081(3),
     work initiated by Eric Snow in Python 3.7.)

   * Some macros have been converted to static inline functions:
     parameter types and return type are well defined, they don’t have
     issues specific to macros, variables have a local scopes.
     Examples:

        * *note Py_INCREF(): 790, *note Py_DECREF(): 791.

        * *note Py_XINCREF(): c5c, *note Py_XDECREF(): 993.

        * ‘PyObject_INIT’, ‘PyObject_INIT_VAR’

        * Private functions: ‘_PyObject_GC_TRACK()’,
          ‘_PyObject_GC_UNTRACK()’, ‘_Py_Dealloc()’

     (Contributed by Victor Stinner in bpo-35059(4).)

   * The ‘PyByteArray_Init()’ and ‘PyByteArray_Fini()’ functions have
     been removed.  They did nothing since Python 2.7.4 and Python
     3.2.0, were excluded from the limited API (stable ABI), and were
     not documented.  (Contributed by Victor Stinner in bpo-35713(5).)

   * The result of *note PyExceptionClass_Name(): c5d. is now of type
     ‘const char *’ rather of ‘char *’.  (Contributed by Serhiy
     Storchaka in bpo-33818(6).)

   * The duality of ‘Modules/Setup.dist’ and ‘Modules/Setup’ has been
     removed.  Previously, when updating the CPython source tree, one
     had to manually copy ‘Modules/Setup.dist’ (inside the source tree)
     to ‘Modules/Setup’ (inside the build tree) in order to reflect any
     changes upstream.  This was of a small benefit to packagers at the
     expense of a frequent annoyance to developers following CPython
     development, as forgetting to copy the file could produce build
     failures.

     Now the build system always reads from ‘Modules/Setup’ inside the
     source tree.  People who want to customize that file are encouraged
     to maintain their changes in a git fork of CPython or as patch
     files, as they would do for any other change to the source tree.

     (Contributed by Antoine Pitrou in bpo-32430(7).)

   * Functions that convert Python number to C integer like *note
     PyLong_AsLong(): 605. and argument parsing functions like *note
     PyArg_ParseTuple(): 3c1. with integer converting format units like
     ‘'i'’ will now use the *note __index__(): 19e. special method
     instead of *note __int__(): 19d, if available.  The deprecation
     warning will be emitted for objects with the ‘__int__()’ method but
     without the ‘__index__()’ method (like *note Decimal: 1fe. and
     *note Fraction: 213.).  *note PyNumber_Check(): c5e. will now
     return ‘1’ for objects implementing ‘__index__()’.  *note
     PyNumber_Long(): c5f, *note PyNumber_Float(): c60. and *note
     PyFloat_AsDouble(): c61. also now use the ‘__index__()’ method if
     available.  (Contributed by Serhiy Storchaka in bpo-36048(8) and
     bpo-20092(9).)

   * Heap-allocated type objects will now increase their reference count
     in *note PyObject_Init(): c62. (and its parallel macro
     ‘PyObject_INIT’) instead of in *note PyType_GenericAlloc(): c63.
     Types that modify instance allocation or deallocation may need to
     be adjusted.  (Contributed by Eddie Elizondo in bpo-35810(10).)

   * The new function ‘PyCode_NewWithPosOnlyArgs()’ allows to create
     code objects like ‘PyCode_New()’, but with an extra
     'posonlyargcount' parameter for indicating the number of
     positional-only arguments.  (Contributed by Pablo Galindo in
     bpo-37221(11).)

   * ‘Py_SetPath()’ now sets *note sys.executable: 3ed. to the program
     full path (*note Py_GetProgramFullPath(): 3ec.) rather than to the
     program name (*note Py_GetProgramName(): 3ee.).  (Contributed by
     Victor Stinner in bpo-38234(12).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36707

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35134

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35081

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35059

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35713

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33818

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32430

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36048

   (9) https://bugs.python.org/issue?@action=redirect&bpo=20092

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35810

   (11) https://bugs.python.org/issue?@action=redirect&bpo=37221

   (12) https://bugs.python.org/issue?@action=redirect&bpo=38234


File: python.info,  Node: Deprecated<7>,  Next: API and Feature Removals,  Prev: Build and C API Changes,  Up: What’s New In Python 3 8

1.7.8 Deprecated
----------------

   * The distutils ‘bdist_wininst’ command is now deprecated, use
     ‘bdist_wheel’ (wheel packages) instead.  (Contributed by Victor
     Stinner in bpo-37481(1).)

   * Deprecated methods ‘getchildren()’ and ‘getiterator()’ in the *note
     ElementTree: 12b. module now emit a *note DeprecationWarning: 1a3.
     instead of *note PendingDeprecationWarning: ac8.  They will be
     removed in Python 3.9.  (Contributed by Serhiy Storchaka in
     bpo-29209(2).)

   * Passing an object that is not an instance of *note
     concurrent.futures.ThreadPoolExecutor: 94a. to *note
     loop.set_default_executor(): 94b. is deprecated and will be
     prohibited in Python 3.9.  (Contributed by Elvis Pranskevichus in
     bpo-34075(3).)

   * The *note __getitem__(): 588. methods of *note
     xml.dom.pulldom.DOMEventStream: 93f, *note
     wsgiref.util.FileWrapper: 940. and *note fileinput.FileInput: 941.
     have been deprecated.

     Implementations of these methods have been ignoring their 'index'
     parameter, and returning the next item instead.  (Contributed by
     Berker Peksag in bpo-9372(4).)

   * The *note typing.NamedTuple: 331. class has deprecated the
     ‘_field_types’ attribute in favor of the ‘__annotations__’
     attribute which has the same information.  (Contributed by Raymond
     Hettinger in bpo-36320(5).)

   * *note ast: 9. classes ‘Num’, ‘Str’, ‘Bytes’, ‘NameConstant’ and
     ‘Ellipsis’ are considered deprecated and will be removed in future
     Python versions.  *note Constant: 2ef. should be used instead.
     (Contributed by Serhiy Storchaka in bpo-32892(6).)

   * *note ast.NodeVisitor: 2f0. methods ‘visit_Num()’, ‘visit_Str()’,
     ‘visit_Bytes()’, ‘visit_NameConstant()’ and ‘visit_Ellipsis()’ are
     deprecated now and will not be called in future Python versions.
     Add the *note visit_Constant(): c65. method to handle all constant
     nodes.  (Contributed by Serhiy Storchaka in bpo-36917(7).)

   * The ‘@asyncio.coroutine’ *note decorator: 93b. is deprecated and
     will be removed in version 3.10.  Instead of ‘@asyncio.coroutine’,
     use *note async def: 7ee. instead.  (Contributed by Andrew Svetlov
     in bpo-36921(8).)

   * In *note asyncio: b, the explicit passing of a 'loop' argument has
     been deprecated and will be removed in version 3.10 for the
     following: *note asyncio.sleep(): c66, *note asyncio.gather(): 814,
     *note asyncio.shield(): c67, *note asyncio.wait_for(): 816, *note
     asyncio.wait(): 6a8, *note asyncio.as_completed(): 4c7, *note
     asyncio.Task: 1c7, *note asyncio.Lock: c68, *note asyncio.Event:
     2f4, *note asyncio.Condition: c69, *note asyncio.Semaphore: c6a,
     *note asyncio.BoundedSemaphore: c6b, *note asyncio.Queue: c6c,
     *note asyncio.create_subprocess_exec(): c6d, and *note
     asyncio.create_subprocess_shell(): c6e.

   * The explicit passing of coroutine objects to *note asyncio.wait():
     6a8. has been deprecated and will be removed in version 3.11.
     (Contributed by Yury Selivanov in bpo-34790(9).)

   * The following functions and methods are deprecated in the *note
     gettext: 67. module: ‘lgettext()’, ‘ldgettext()’, ‘lngettext()’ and
     ‘ldngettext()’.  They return encoded bytes, and it’s possible that
     you will get unexpected Unicode-related exceptions if there are
     encoding problems with the translated strings.  It’s much better to
     use alternatives which return Unicode strings in Python 3.  These
     functions have been broken for a long time.

     Function ‘bind_textdomain_codeset()’, methods
     ‘NullTranslations.output_charset()’ and
     ‘NullTranslations.set_output_charset()’, and the 'codeset'
     parameter of functions *note translation(): c6f. and *note
     install(): c70. are also deprecated, since they are only used for
     the ‘l*gettext()’ functions.  (Contributed by Serhiy Storchaka in
     bpo-33710(10).)

   * The ‘isAlive()’ method of *note threading.Thread: 176. has been
     deprecated.  (Contributed by Donghee Na in bpo-35283(11).)

   * Many builtin and extension functions that take integer arguments
     will now emit a deprecation warning for *note Decimal: 1fe.s, *note
     Fraction: 213.s and any other objects that can be converted to
     integers only with a loss (e.g.  that have the *note __int__():
     19d. method but do not have the *note __index__(): 19e. method).
     In future version they will be errors.  (Contributed by Serhiy
     Storchaka in bpo-36048(12).)

   * Deprecated passing the following arguments as keyword arguments:

        - 'func' in *note functools.partialmethod(): 218, *note
          weakref.finalize(): c71, *note profile.Profile.runcall(): c72,
          ‘cProfile.Profile.runcall()’, *note bdb.Bdb.runcall(): c73,
          *note trace.Trace.runfunc(): c74. and *note curses.wrapper():
          c75.

        - 'function' in *note unittest.TestCase.addCleanup(): c76.

        - 'fn' in the *note submit(): c77. method of *note
          concurrent.futures.ThreadPoolExecutor: 94a. and *note
          concurrent.futures.ProcessPoolExecutor: 1d6.

        - 'callback' in *note contextlib.ExitStack.callback(): c78,
          ‘contextlib.AsyncExitStack.callback()’ and *note
          contextlib.AsyncExitStack.push_async_callback(): c79.

        - 'c' and 'typeid' in the ‘create()’ method of
          ‘multiprocessing.managers.Server’ and
          ‘multiprocessing.managers.SharedMemoryServer’.

        - 'obj' in *note weakref.finalize(): c71.

     In future releases of Python, they will be *note positional-only:
     c7a.  (Contributed by Serhiy Storchaka in bpo-36492(13).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37481

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29209

   (3) https://bugs.python.org/issue?@action=redirect&bpo=34075

   (4) https://bugs.python.org/issue?@action=redirect&bpo=9372

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36320

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32892

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36917

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36921

   (9) https://bugs.python.org/issue?@action=redirect&bpo=34790

   (10) https://bugs.python.org/issue?@action=redirect&bpo=33710

   (11) https://bugs.python.org/issue?@action=redirect&bpo=35283

   (12) https://bugs.python.org/issue?@action=redirect&bpo=36048

   (13) https://bugs.python.org/issue?@action=redirect&bpo=36492


File: python.info,  Node: API and Feature Removals,  Next: Porting to Python 3 8,  Prev: Deprecated<7>,  Up: What’s New In Python 3 8

1.7.9 API and Feature Removals
------------------------------

The following features and APIs have been removed from Python 3.8:

   * Starting with Python 3.3, importing ABCs from *note collections:
     1e. was deprecated, and importing should be done from *note
     collections.abc: 1f.  Being able to import from collections was
     marked for removal in 3.8, but has been delayed to 3.9.  (See
     gh-81134(1).)

   * The ‘macpath’ module, deprecated in Python 3.7, has been removed.
     (Contributed by Victor Stinner in bpo-35471(2).)

   * The function ‘platform.popen()’ has been removed, after having been
     deprecated since Python 3.3: use *note os.popen(): 31a. instead.
     (Contributed by Victor Stinner in bpo-35345(3).)

   * The function ‘time.clock()’ has been removed, after having been
     deprecated since Python 3.3: use *note time.perf_counter(): c7c. or
     *note time.process_time(): c7d. instead, depending on your
     requirements, to have well-defined behavior.  (Contributed by
     Matthias Bussonnier in bpo-36895(4).)

   * The ‘pyvenv’ script has been removed in favor of ‘python3.8 -m
     venv’ to help eliminate confusion as to what Python interpreter the
     ‘pyvenv’ script is tied to.  (Contributed by Brett Cannon in
     bpo-25427(5).)

   * ‘parse_qs’, ‘parse_qsl’, and ‘escape’ are removed from the ‘cgi’
     module.  They are deprecated in Python 3.2 or older.  They should
     be imported from the ‘urllib.parse’ and ‘html’ modules instead.

   * ‘filemode’ function is removed from the *note tarfile: e4. module.
     It is not documented and deprecated since Python 3.3.

   * The *note XMLParser: c4b. constructor no longer accepts the 'html'
     argument.  It never had an effect and was deprecated in Python 3.4.
     All other parameters are now *note keyword-only: 5a5.  (Contributed
     by Serhiy Storchaka in bpo-29209(6).)

   * Removed the ‘doctype()’ method of *note XMLParser: c4b.
     (Contributed by Serhiy Storchaka in bpo-29209(7).)

   * «unicode_internal» codec is removed.  (Contributed by Inada Naoki
     in bpo-36297(8).)

   * The ‘Cache’ and ‘Statement’ objects of the *note sqlite3: d4.
     module are not exposed to the user.  (Contributed by Aviv Palivoda
     in bpo-30262(9).)

   * The ‘bufsize’ keyword argument of *note fileinput.input(): a02. and
     *note fileinput.FileInput(): 941. which was ignored and deprecated
     since Python 3.6 has been removed.  bpo-36952(10) (Contributed by
     Matthias Bussonnier.)

   * The functions ‘sys.set_coroutine_wrapper()’ and
     ‘sys.get_coroutine_wrapper()’ deprecated in Python 3.7 have been
     removed; bpo-36933(11) (Contributed by Matthias Bussonnier.)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/81134

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35471

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35345

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36895

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25427

   (6) https://bugs.python.org/issue?@action=redirect&bpo=29209

   (7) https://bugs.python.org/issue?@action=redirect&bpo=29209

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36297

   (9) https://bugs.python.org/issue?@action=redirect&bpo=30262

   (10) https://bugs.python.org/issue?@action=redirect&bpo=36952

   (11) https://bugs.python.org/issue?@action=redirect&bpo=36933


File: python.info,  Node: Porting to Python 3 8,  Next: Notable changes in Python 3 8 1,  Prev: API and Feature Removals,  Up: What’s New In Python 3 8

1.7.10 Porting to Python 3.8
----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code.

* Menu:

* Changes in Python behavior::
* Changes in the Python API: Changes in the Python API<5>.
* Changes in the C API: Changes in the C API<5>.
* CPython bytecode changes: CPython bytecode changes<5>.
* Demos and Tools::


File: python.info,  Node: Changes in Python behavior,  Next: Changes in the Python API<5>,  Up: Porting to Python 3 8

1.7.10.1 Changes in Python behavior
...................................

   * Yield expressions (both ‘yield’ and ‘yield from’ clauses) are now
     disallowed in comprehensions and generator expressions (aside from
     the iterable expression in the leftmost ‘for’ clause).
     (Contributed by Serhiy Storchaka in bpo-10544(1).)

   * The compiler now produces a *note SyntaxWarning: 1ae. when identity
     checks (‘is’ and ‘is not’) are used with certain types of literals
     (e.g.  strings, numbers).  These can often work by accident in
     CPython, but are not guaranteed by the language spec.  The warning
     advises users to use equality tests (‘==’ and ‘!=’) instead.
     (Contributed by Serhiy Storchaka in bpo-34850(2).)

   * The CPython interpreter can swallow exceptions in some
     circumstances.  In Python 3.8 this happens in fewer cases.  In
     particular, exceptions raised when getting the attribute from the
     type dictionary are no longer ignored.  (Contributed by Serhiy
     Storchaka in bpo-35459(3).)

   * Removed ‘__str__’ implementations from builtin types *note bool:
     3c3, *note int: 19b, *note float: 196, *note complex: 197. and few
     classes from the standard library.  They now inherit ‘__str__()’
     from *note object: c80.  As result, defining the ‘__repr__()’
     method in the subclass of these classes will affect their string
     representation.  (Contributed by Serhiy Storchaka in bpo-36793(4).)

   * On AIX, *note sys.platform: 291. doesn’t contain the major version
     anymore.  It is always ‘'aix'’, instead of ‘'aix3'’ ..  ‘'aix7'’.
     Since older Python versions include the version number, so it is
     recommended to always use ‘sys.platform.startswith('aix')’.
     (Contributed by M. Felt in bpo-36588(5).)

   * ‘PyEval_AcquireLock()’ and ‘PyEval_AcquireThread()’ now terminate
     the current thread if called while the interpreter is finalizing,
     making them consistent with *note PyEval_RestoreThread(): 648,
     *note Py_END_ALLOW_THREADS(): c81, and *note PyGILState_Ensure():
     64a.  If this behavior is not desired, guard the call by checking
     ‘_Py_IsFinalizing()’ or *note sys.is_finalizing(): c82.
     (Contributed by Joannah Nanjekye in bpo-36475(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10544

   (2) https://bugs.python.org/issue?@action=redirect&bpo=34850

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35459

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36793

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36588

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36475


File: python.info,  Node: Changes in the Python API<5>,  Next: Changes in the C API<5>,  Prev: Changes in Python behavior,  Up: Porting to Python 3 8

1.7.10.2 Changes in the Python API
..................................

   * The *note os.getcwdb(): c84. function now uses the UTF-8 encoding
     on Windows, rather than the ANSI code page: see PEP 529(1) for the
     rationale.  The function is no longer deprecated on Windows.
     (Contributed by Victor Stinner in bpo-37412(2).)

   * *note subprocess.Popen: 4b8. can now use *note os.posix_spawn():
     52f. in some cases for better performance.  On Windows Subsystem
     for Linux and QEMU User Emulation, the *note Popen: 4b8.
     constructor using *note os.posix_spawn(): 52f. no longer raises an
     exception on errors like «missing program».  Instead the child
     process fails with a non-zero *note returncode: c85.  (Contributed
     by Joannah Nanjekye and Victor Stinner in bpo-35537(3).)

   * The 'preexec_fn' argument of * *note subprocess.Popen: 4b8. is no
     longer compatible with subinterpreters.  The use of the parameter
     in a subinterpreter now raises *note RuntimeError: 244.
     (Contributed by Eric Snow in bpo-34651(4), modified by Christian
     Heimes in bpo-37951(5).)

   * The *note imaplib.IMAP4.logout(): c86. method no longer silently
     ignores arbitrary exceptions.  (Contributed by Victor Stinner in
     bpo-36348(6).)

   * The function ‘platform.popen()’ has been removed, after having been
     deprecated since Python 3.3: use *note os.popen(): 31a. instead.
     (Contributed by Victor Stinner in bpo-35345(7).)

   * The *note statistics.mode(): c87. function no longer raises an
     exception when given multimodal data.  Instead, it returns the
     first mode encountered in the input data.  (Contributed by Raymond
     Hettinger in bpo-35892(8).)

   * The *note selection(): c88. method of the *note
     tkinter.ttk.Treeview: c89. class no longer takes arguments.  Using
     it with arguments for changing the selection was deprecated in
     Python 3.6.  Use specialized methods like *note selection_set():
     c8a. for changing the selection.  (Contributed by Serhiy Storchaka
     in bpo-31508(9).)

   * The *note writexml(): c8b, *note toxml(): c8c. and *note
     toprettyxml(): c8d. methods of *note xml.dom.minidom: 128. and the
     *note write(): c8e. method of *note xml.etree.ElementTree: 12b. now
     preserve the attribute order specified by the user.  (Contributed
     by Diego Rojas and Raymond Hettinger in bpo-34160(10).)

   * A *note dbm.dumb: 36. database opened with flags ‘'r'’ is now
     read-only.  *note dbm.dumb.open(): c8f. with flags ‘'r'’ and ‘'w'’
     no longer creates a database if it does not exist.  (Contributed by
     Serhiy Storchaka in bpo-32749(11).)

   * The ‘doctype()’ method defined in a subclass of *note XMLParser:
     c4b. will no longer be called and will emit a *note RuntimeWarning:
     4d8. instead of a *note DeprecationWarning: 1a3.  Define the *note
     doctype(): c90. method on a target for handling an XML doctype
     declaration.  (Contributed by Serhiy Storchaka in bpo-29209(12).)

   * A *note RuntimeError: 244. is now raised when the custom metaclass
     doesn’t provide the ‘__classcell__’ entry in the namespace passed
     to ‘type.__new__’.  A *note DeprecationWarning: 1a3. was emitted in
     Python 3.6–3.7.  (Contributed by Serhiy Storchaka in
     bpo-23722(13).)

   * The *note cProfile.Profile: bd8. class can now be used as a context
     manager.  (Contributed by Scott Sanderson in bpo-29235(14).)

   * *note shutil.copyfile(): c50, *note shutil.copy(): c51, *note
     shutil.copy2(): c52, *note shutil.copytree(): c20. and *note
     shutil.move(): c53. use platform-specific «fast-copy» syscalls (see
     *note Platform-dependent efficient copy operations: c55. section).

   * *note shutil.copyfile(): c50. default buffer size on Windows was
     changed from 16 KiB to 1 MiB.

   * The ‘PyGC_Head’ struct has changed completely.  All code that
     touched the struct member should be rewritten.  (See
     bpo-33597(15).)

   * The *note PyInterpreterState: abc. struct has been moved into the
     «internal» header files (specifically
     Include/internal/pycore_pystate.h).  An opaque ‘PyInterpreterState’
     is still available as part of the public API (and stable ABI). The
     docs indicate that none of the struct’s fields are public, so we
     hope no one has been using them.  However, if you do rely on one or
     more of those private fields and have no alternative then please
     open a BPO issue.  We’ll work on helping you adjust (possibly
     including adding accessor functions to the public API). (See
     bpo-35886(16).)

   * The *note mmap.flush(): c91. method now returns ‘None’ on success
     and raises an exception on error under all platforms.  Previously,
     its behavior was platform-dependent: a nonzero value was returned
     on success; zero was returned on error under Windows.  A zero value
     was returned on success; an exception was raised on error under
     Unix.  (Contributed by Berker Peksag in bpo-2122(17).)

   * *note xml.dom.minidom: 128. and *note xml.sax: 12f. modules no
     longer process external entities by default.  (Contributed by
     Christian Heimes in bpo-17239(18).)

   * Deleting a key from a read-only *note dbm: 35. database (*note
     dbm.dumb: 36, *note dbm.gnu: 37. or *note dbm.ndbm: 38.) raises
     ‘error’ (*note dbm.dumb.error: c92, *note dbm.gnu.error: c93. or
     *note dbm.ndbm.error: c94.) instead of *note KeyError: 5e7.
     (Contributed by Xiang Zhang in bpo-33106(19).)

   * Simplified AST for literals.  All constants will be represented as
     *note ast.Constant: 2ef. instances.  Instantiating old classes
     ‘Num’, ‘Str’, ‘Bytes’, ‘NameConstant’ and ‘Ellipsis’ will return an
     instance of ‘Constant’.  (Contributed by Serhiy Storchaka in
     bpo-32892(20).)

   * *note expanduser(): c0b. on Windows now prefers the ‘USERPROFILE’
     environment variable and does not use ‘HOME’, which is not normally
     set for regular user accounts.  (Contributed by Anthony Sottile in
     bpo-36264(21).)

   * The exception *note asyncio.CancelledError: 4d5. now inherits from
     *note BaseException: 7d8. rather than *note Exception: bcf. and no
     longer inherits from *note concurrent.futures.CancelledError: bd0.
     (Contributed by Yury Selivanov in bpo-32528(22).)

   * The function *note asyncio.wait_for(): 816. now correctly waits for
     cancellation when using an instance of *note asyncio.Task: 1c7.
     Previously, upon reaching 'timeout', it was cancelled and
     immediately returned.  (Contributed by Elvis Pranskevichus in
     bpo-32751(23).)

   * The function *note asyncio.BaseTransport.get_extra_info(): c95. now
     returns a safe to use socket object when “socket” is passed to the
     'name' parameter.  (Contributed by Yury Selivanov in
     bpo-37027(24).)

   * *note asyncio.BufferedProtocol: c96. has graduated to the stable
     API.

   * DLL dependencies for extension modules and DLLs loaded with *note
     ctypes: 2e. on Windows are now resolved more securely.  Only the
     system paths, the directory containing the DLL or PYD file, and
     directories added with *note add_dll_directory(): bdf. are searched
     for load-time dependencies.  Specifically, ‘PATH’ and the current
     working directory are no longer used, and modifications to these
     will no longer have any effect on normal DLL resolution.  If your
     application relies on these mechanisms, you should check for *note
     add_dll_directory(): bdf. and if it exists, use it to add your DLLs
     directory while loading your library.  Note that Windows 7 users
     will need to ensure that Windows Update KB2533623 has been
     installed (this is also verified by the installer).  (Contributed
     by Steve Dower in bpo-36085(25).)

   * The header files and functions related to pgen have been removed
     after its replacement by a pure Python implementation.
     (Contributed by Pablo Galindo in bpo-36623(26).)

   * *note types.CodeType: 32f. has a new parameter in the second
     position of the constructor ('posonlyargcount') to support
     positional-only arguments defined in PEP 570(27).  The first
     argument ('argcount') now represents the total number of positional
     arguments (including positional-only arguments).  The new
     ‘replace()’ method of *note types.CodeType: 32f. can be used to
     make the code future-proof.

   * The parameter ‘digestmod’ for *note hmac.new(): c98. no longer uses
     the MD5 digest by default.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0529/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=37412

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35537

   (4) https://bugs.python.org/issue?@action=redirect&bpo=34651

   (5) https://bugs.python.org/issue?@action=redirect&bpo=37951

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36348

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35345

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35892

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31508

   (10) https://bugs.python.org/issue?@action=redirect&bpo=34160

   (11) https://bugs.python.org/issue?@action=redirect&bpo=32749

   (12) https://bugs.python.org/issue?@action=redirect&bpo=29209

   (13) https://bugs.python.org/issue?@action=redirect&bpo=23722

   (14) https://bugs.python.org/issue?@action=redirect&bpo=29235

   (15) https://bugs.python.org/issue?@action=redirect&bpo=33597

   (16) https://bugs.python.org/issue?@action=redirect&bpo=35886

   (17) https://bugs.python.org/issue?@action=redirect&bpo=2122

   (18) https://bugs.python.org/issue?@action=redirect&bpo=17239

   (19) https://bugs.python.org/issue?@action=redirect&bpo=33106

   (20) https://bugs.python.org/issue?@action=redirect&bpo=32892

   (21) https://bugs.python.org/issue?@action=redirect&bpo=36264

   (22) https://bugs.python.org/issue?@action=redirect&bpo=32528

   (23) https://bugs.python.org/issue?@action=redirect&bpo=32751

   (24) https://bugs.python.org/issue?@action=redirect&bpo=37027

   (25) https://bugs.python.org/issue?@action=redirect&bpo=36085

   (26) https://bugs.python.org/issue?@action=redirect&bpo=36623

   (27) https://peps.python.org/pep-0570/


File: python.info,  Node: Changes in the C API<5>,  Next: CPython bytecode changes<5>,  Prev: Changes in the Python API<5>,  Up: Porting to Python 3 8

1.7.10.3 Changes in the C API
.............................

   * The *note PyCompilerFlags: c9a. structure got a new
     'cf_feature_version' field.  It should be initialized to
     ‘PY_MINOR_VERSION’.  The field is ignored by default, and is used
     if and only if ‘PyCF_ONLY_AST’ flag is set in 'cf_flags'.
     (Contributed by Guido van Rossum in bpo-35766(1).)

   * The ‘PyEval_ReInitThreads()’ function has been removed from the C
     API. It should not be called explicitly: use *note
     PyOS_AfterFork_Child(): 430. instead.  (Contributed by Victor
     Stinner in bpo-36728(2).)

   * On Unix, C extensions are no longer linked to libpython except on
     Android and Cygwin.  When Python is embedded, ‘libpython’ must not
     be loaded with ‘RTLD_LOCAL’, but ‘RTLD_GLOBAL’ instead.
     Previously, using ‘RTLD_LOCAL’, it was already not possible to load
     C extensions which were not linked to ‘libpython’, like C
     extensions of the standard library built by the ‘*shared*’ section
     of ‘Modules/Setup’.  (Contributed by Victor Stinner in
     bpo-21536(3).)

   * Use of ‘#’ variants of formats in parsing or building value (e.g.
     *note PyArg_ParseTuple(): 3c1, *note Py_BuildValue(): 3c2, *note
     PyObject_CallFunction(): 63f, etc.)  without ‘PY_SSIZE_T_CLEAN’
     defined raises ‘DeprecationWarning’ now.  It will be removed in
     3.10 or 4.0.  Read *note Parsing arguments and building values:
     3d5. for detail.  (Contributed by Inada Naoki in bpo-36381(4).)

   * Instances of heap-allocated types (such as those created with *note
     PyType_FromSpec(): 79e.) hold a reference to their type object.
     Increasing the reference count of these type objects has been moved
     from *note PyType_GenericAlloc(): c63. to the more low-level
     functions, *note PyObject_Init(): c62. and ‘PyObject_INIT’.  This
     makes types created through *note PyType_FromSpec(): 79e. behave
     like other classes in managed code.

     *note Statically allocated types: 984. are not affected.

     For the vast majority of cases, there should be no side effect.
     However, types that manually increase the reference count after
     allocating an instance (perhaps to work around the bug) may now
     become immortal.  To avoid this, these classes need to call
     Py_DECREF on the type object during instance deallocation.

     To correctly port these types into 3.8, please apply the following
     changes:

        * Remove *note Py_INCREF: 790. on the type object after
          allocating an instance - if any.  This may happen after
          calling *note PyObject_New: b7e, *note PyObject_NewVar: b7f,
          *note PyObject_GC_New(): c9b, *note PyObject_GC_NewVar(): c9c,
          or any other custom allocator that uses *note PyObject_Init():
          c62. or ‘PyObject_INIT’.

          Example:

               static foo_struct *
               foo_new(PyObject *type) {
                   foo_struct *foo = PyObject_GC_New(foo_struct, (PyTypeObject *) type);
                   if (foo == NULL)
                       return NULL;
               #if PY_VERSION_HEX < 0x03080000
                   // Workaround for Python issue 35810; no longer necessary in Python 3.8
                   PY_INCREF(type)
               #endif
                   return foo;
               }

        * Ensure that all custom ‘tp_dealloc’ functions of
          heap-allocated types decrease the type’s reference count.

          Example:

               static void
               foo_dealloc(foo_struct *instance) {
                   PyObject *type = Py_TYPE(instance);
                   PyObject_GC_Del(instance);
               #if PY_VERSION_HEX >= 0x03080000
                   // This was not needed before Python 3.8 (Python issue 35810)
                   Py_DECREF(type);
               #endif
               }

     (Contributed by Eddie Elizondo in bpo-35810(5).)

   * The *note Py_DEPRECATED(): c9d. macro has been implemented for
     MSVC.  The macro now must be placed before the symbol name.

     Example:

          Py_DEPRECATED(3.8) PyAPI_FUNC(int) Py_OldFunction(void);

     (Contributed by Zackery Spytz in bpo-33407(6).)

   * The interpreter does not pretend to support binary compatibility of
     extension types across feature releases, anymore.  A *note
     PyTypeObject: c9e. exported by a third-party extension module is
     supposed to have all the slots expected in the current Python
     version, including *note tp_finalize: c9f. (*note
     Py_TPFLAGS_HAVE_FINALIZE: 427. is not checked anymore before
     reading *note tp_finalize: c9f.).

     (Contributed by Antoine Pitrou in bpo-32388(7).)

   * The functions ‘PyNode_AddChild()’ and ‘PyParser_AddToken()’ now
     accept two additional ‘int’ arguments 'end_lineno' and
     'end_col_offset'.

   * The ‘libpython38.a’ file to allow MinGW tools to link directly
     against ‘python38.dll’ is no longer included in the regular Windows
     distribution.  If you require this file, it may be generated with
     the ‘gendef’ and ‘dlltool’ tools, which are part of the MinGW
     binutils package:

          gendef - python38.dll > tmp.def
          dlltool --dllname python38.dll --def tmp.def --output-lib libpython38.a

     The location of an installed ‘pythonXY.dll’ will depend on the
     installation options and the version and language of Windows.  See
     *note Using Python on Windows: ca0. for more information.  The
     resulting library should be placed in the same directory as
     ‘pythonXY.lib’, which is generally the ‘libs’ directory under your
     Python installation.

     (Contributed by Steve Dower in bpo-37351(8).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35766

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36728

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21536

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36381

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35810

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33407

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32388

   (8) https://bugs.python.org/issue?@action=redirect&bpo=37351


File: python.info,  Node: CPython bytecode changes<5>,  Next: Demos and Tools,  Prev: Changes in the C API<5>,  Up: Porting to Python 3 8

1.7.10.4 CPython bytecode changes
.................................

   * The interpreter loop has been simplified by moving the logic of
     unrolling the stack of blocks into the compiler.  The compiler
     emits now explicit instructions for adjusting the stack of values
     and calling the cleaning-up code for *note break: 17f, *note
     continue: 180. and *note return: 1af.

     Removed opcodes ‘BREAK_LOOP’, ‘CONTINUE_LOOP’, ‘SETUP_LOOP’ and
     ‘SETUP_EXCEPT’.  Added new opcodes ‘ROT_FOUR’, ‘BEGIN_FINALLY’,
     ‘CALL_FINALLY’ and ‘POP_FINALLY’.  Changed the behavior of
     ‘END_FINALLY’ and ‘WITH_CLEANUP_START’.

     (Contributed by Mark Shannon, Antoine Pitrou and Serhiy Storchaka
     in bpo-17611(1).)

   * Added new opcode *note END_ASYNC_FOR: ca2. for handling exceptions
     raised when awaiting a next item in an *note async for: ca3. loop.
     (Contributed by Serhiy Storchaka in bpo-33041(2).)

   * The *note MAP_ADD: ca4. now expects the value as the first element
     in the stack and the key as the second element.  This change was
     made so the key is always evaluated before the value in dictionary
     comprehensions, as proposed by PEP 572(3).  (Contributed by Jörn
     Heissler in bpo-35224(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17611

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33041

   (3) https://peps.python.org/pep-0572/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35224


File: python.info,  Node: Demos and Tools,  Prev: CPython bytecode changes<5>,  Up: Porting to Python 3 8

1.7.10.5 Demos and Tools
........................

Added a benchmark script for timing various ways to access variables:
‘Tools/scripts/var_access_benchmark.py’.  (Contributed by Raymond
Hettinger in bpo-35884(1).)

Here’s a summary of performance improvements since Python 3.3:

     Python version                       3.3     3.4     3.5     3.6     3.7     3.8
     --------------                       ---     ---     ---     ---     ---     ---

     Variable and attribute read access:
         read_local                       4.0     7.1     7.1     5.4     5.1     3.9
         read_nonlocal                    5.3     7.1     8.1     5.8     5.4     4.4
         read_global                     13.3    15.5    19.0    14.3    13.6     7.6
         read_builtin                    20.0    21.1    21.6    18.5    19.0     7.5
         read_classvar_from_class        20.5    25.6    26.5    20.7    19.5    18.4
         read_classvar_from_instance     18.5    22.8    23.5    18.8    17.1    16.4
         read_instancevar                26.8    32.4    33.1    28.0    26.3    25.4
         read_instancevar_slots          23.7    27.8    31.3    20.8    20.8    20.2
         read_namedtuple                 68.5    73.8    57.5    45.0    46.8    18.4
         read_boundmethod                29.8    37.6    37.9    29.6    26.9    27.7

     Variable and attribute write access:
         write_local                      4.6     8.7     9.3     5.5     5.3     4.3
         write_nonlocal                   7.3    10.5    11.1     5.6     5.5     4.7
         write_global                    15.9    19.7    21.2    18.0    18.0    15.8
         write_classvar                  81.9    92.9    96.0   104.6   102.1    39.2
         write_instancevar               36.4    44.6    45.8    40.0    38.9    35.5
         write_instancevar_slots         28.7    35.6    36.1    27.3    26.6    25.7

     Data structure read access:
         read_list                       19.2    24.2    24.5    20.8    20.8    19.0
         read_deque                      19.9    24.7    25.5    20.2    20.6    19.8
         read_dict                       19.7    24.3    25.7    22.3    23.0    21.0
         read_strdict                    17.9    22.6    24.3    19.5    21.2    18.9

     Data structure write access:
         write_list                      21.2    27.1    28.5    22.5    21.6    20.0
         write_deque                     23.8    28.7    30.1    22.7    21.8    23.5
         write_dict                      25.9    31.4    33.3    29.3    29.2    24.7
         write_strdict                   22.9    28.4    29.9    27.5    25.2    23.1

     Stack (or queue) operations:
         list_append_pop                144.2    93.4   112.7    75.4    74.2    50.8
         deque_append_pop                30.4    43.5    57.0    49.4    49.2    42.5
         deque_append_popleft            30.8    43.7    57.3    49.7    49.7    42.8

     Timing loop:
         loop_overhead                    0.3     0.5     0.6     0.4     0.3     0.3

The benchmarks were measured on an Intel® Core™ i7-4960HQ processor(2)
running the macOS 64-bit builds found at python.org(3).  The benchmark
script displays timings in nanoseconds.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35884

   (2) 
https://ark.intel.com/content/www/us/en/ark/products/76088/intel-core-i7-4960hq-processor-6m-cache-up-to-3-80-ghz.html

   (3) https://www.python.org/downloads/macos/


File: python.info,  Node: Notable changes in Python 3 8 1,  Next: Notable changes in Python 3 8 2,  Prev: Porting to Python 3 8,  Up: What’s New In Python 3 8

1.7.11 Notable changes in Python 3.8.1
--------------------------------------

Due to significant security concerns, the 'reuse_address' parameter of
*note asyncio.loop.create_datagram_endpoint(): 93d. is no longer
supported.  This is because of the behavior of the socket option
‘SO_REUSEADDR’ in UDP. For more details, see the documentation for
‘loop.create_datagram_endpoint()’.  (Contributed by Kyle Stanley,
Antoine Pitrou, and Yury Selivanov in bpo-37228(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37228


File: python.info,  Node: Notable changes in Python 3 8 2,  Next: Notable changes in Python 3 8 3,  Prev: Notable changes in Python 3 8 1,  Up: What’s New In Python 3 8

1.7.12 Notable changes in Python 3.8.2
--------------------------------------

Fixed a regression with the ‘ignore’ callback of *note
shutil.copytree(): c20.  The argument types are now str and List[str]
again.  (Contributed by Manuel Barkhau and Giampaolo Rodola in
gh-83571(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/83571


File: python.info,  Node: Notable changes in Python 3 8 3,  Next: Notable changes in Python 3 8 8,  Prev: Notable changes in Python 3 8 2,  Up: What’s New In Python 3 8

1.7.13 Notable changes in Python 3.8.3
--------------------------------------

The constant values of future flags in the *note __future__: 0. module
are updated in order to prevent collision with compiler flags.
Previously ‘PyCF_ALLOW_TOP_LEVEL_AWAIT’ was clashing with
‘CO_FUTURE_DIVISION’.  (Contributed by Batuhan Taskaya in gh-83743(1))

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/83743


File: python.info,  Node: Notable changes in Python 3 8 8,  Next: Notable changes in Python 3 8 9,  Prev: Notable changes in Python 3 8 3,  Up: What’s New In Python 3 8

1.7.14 Notable changes in Python 3.8.8
--------------------------------------

Earlier Python versions allowed using both ‘;’ and ‘&’ as query
parameter separators in *note urllib.parse.parse_qs(): 31f. and *note
urllib.parse.parse_qsl(): 31e.  Due to security concerns, and to conform
with newer W3C recommendations, this has been changed to allow only a
single separator key, with ‘&’ as the default.  This change also affects
‘cgi.parse()’ and ‘cgi.parse_multipart()’ as they use the affected
functions internally.  For more details, please see their respective
documentation.  (Contributed by Adam Goldschmidt, Senthil Kumaran and
Ken Jin in bpo-42967(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42967


File: python.info,  Node: Notable changes in Python 3 8 9,  Next: Notable changes in Python 3 8 10,  Prev: Notable changes in Python 3 8 8,  Up: What’s New In Python 3 8

1.7.15 Notable changes in Python 3.8.9
--------------------------------------

A security fix alters the *note ftplib.FTP: af8. behavior to not trust
the IPv4 address sent from the remote server when setting up a passive
data channel.  We reuse the ftp server IP address instead.  For unusual
code requiring the old behavior, set a ‘trust_server_pasv_ipv4_address’
attribute on your FTP instance to ‘True’.  (See gh-87451(1))

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/87451


File: python.info,  Node: Notable changes in Python 3 8 10,  Next: Notable changes in Python 3 8 10<2>,  Prev: Notable changes in Python 3 8 9,  Up: What’s New In Python 3 8

1.7.16 Notable changes in Python 3.8.10
---------------------------------------

* Menu:

* macOS 11.0 (Big Sur) and Apple Silicon Mac support: macOS 11 0 Big Sur and Apple Silicon Mac support<2>.


File: python.info,  Node: macOS 11 0 Big Sur and Apple Silicon Mac support<2>,  Up: Notable changes in Python 3 8 10

1.7.16.1 macOS 11.0 (Big Sur) and Apple Silicon Mac support
...........................................................

As of 3.8.10, Python now supports building and running on macOS 11 (Big
Sur) and on Apple Silicon Macs (based on the ‘ARM64’ architecture).  A
new universal build variant, ‘universal2’, is now available to natively
support both ‘ARM64’ and ‘Intel 64’ in one set of executables.  Note
that support for «weaklinking», building binaries targeted for newer
versions of macOS that will also run correctly on older versions by
testing at runtime for missing features, is not included in this
backport from Python 3.9; to support a range of macOS versions, continue
to target for and build on the oldest version in the range.

(Originally contributed by Ronald Oussoren and Lawrence D’Anna in
gh-85272(1), with fixes by FX Coudert and Eli Rykoff, and backported to
3.8 by Maxime Bélanger and Ned Deily)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/85272


File: python.info,  Node: Notable changes in Python 3 8 10<2>,  Next: Notable changes in Python 3 8 12,  Prev: Notable changes in Python 3 8 10,  Up: What’s New In Python 3 8

1.7.17 Notable changes in Python 3.8.10
---------------------------------------

* Menu:

* urllib.parse: urllib parse<4>.


File: python.info,  Node: urllib parse<4>,  Up: Notable changes in Python 3 8 10<2>

1.7.17.1 urllib.parse
.....................

The presence of newline or tab characters in parts of a URL allows for
some forms of attacks.  Following the WHATWG specification that updates
RFC 3986(1), ASCII newline ‘\n’, ‘\r’ and tab ‘\t’ characters are
stripped from the URL by the parser in *note urllib.parse: 110.
preventing such attacks.  The removal characters are controlled by a new
module level variable ‘urllib.parse._UNSAFE_URL_BYTES_TO_REMOVE’.  (See
bpo-43882(2))

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc3986.html

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43882


File: python.info,  Node: Notable changes in Python 3 8 12,  Next: Notable security feature in 3 8 14,  Prev: Notable changes in Python 3 8 10<2>,  Up: What’s New In Python 3 8

1.7.18 Notable changes in Python 3.8.12
---------------------------------------

* Menu:

* Changes in the Python API: Changes in the Python API<6>.


File: python.info,  Node: Changes in the Python API<6>,  Up: Notable changes in Python 3 8 12

1.7.18.1 Changes in the Python API
..................................

Starting with Python 3.8.12 the *note ipaddress: 84. module no longer
accepts any leading zeros in IPv4 address strings.  Leading zeros are
ambiguous and interpreted as octal notation by some libraries.  For
example the legacy function *note socket.inet_aton(): b5c. treats
leading zeros as octal notation.  glibc implementation of modern *note
inet_pton(): b5d. does not accept any leading zeros.

(Originally contributed by Christian Heimes in bpo-36384(1), and
backported to 3.8 by Achraf Merzouki.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36384


File: python.info,  Node: Notable security feature in 3 8 14,  Next: Notable changes in 3 8 17,  Prev: Notable changes in Python 3 8 12,  Up: What’s New In Python 3 8

1.7.19 Notable security feature in 3.8.14
-----------------------------------------

Converting between *note int: 19b. and *note str: 169. in bases other
than 2 (binary), 4, 8 (octal), 16 (hexadecimal), or 32 such as base 10
(decimal) now raises a *note ValueError: 2ec. if the number of digits in
string form is above a limit to avoid potential denial of service
attacks due to the algorithmic complexity.  This is a mitigation for CVE
2020-10735(1).  This limit can be configured or disabled by environment
variable, command line flag, or *note sys: df. APIs.  See the *note
integer string conversion length limitation: 80c. documentation.  The
default limit is 4300 digits in string form.

   ---------- Footnotes ----------

   (1) https://www.cve.org/CVERecord?id=CVE-2020-10735


File: python.info,  Node: Notable changes in 3 8 17,  Prev: Notable security feature in 3 8 14,  Up: What’s New In Python 3 8

1.7.20 Notable changes in 3.8.17
--------------------------------

* Menu:

* tarfile: tarfile<6>.


File: python.info,  Node: tarfile<6>,  Up: Notable changes in 3 8 17

1.7.20.1 tarfile
................

   * The extraction methods in *note tarfile: e4, and *note
     shutil.unpack_archive(): 697, have a new a 'filter' argument that
     allows limiting tar features than may be surprising or dangerous,
     such as creating files outside the destination directory.  See
     *note Extraction filters: 698. for details.  In Python 3.12, use
     without the 'filter' argument will show a *note DeprecationWarning:
     1a3.  In Python 3.14, the default will switch to ‘'data'’.
     (Contributed by Petr Viktorin in PEP 706(1).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0706/


File: python.info,  Node: What’s New In Python 3 7,  Next: What’s New In Python 3 6,  Prev: What’s New In Python 3 8,  Up: Novità in Python

1.8 What’s New In Python 3.7
============================


Editor: Elvis Pranskevichus <<elvis@magic.io>>

This article explains the new features in Python 3.7, compared to 3.6.
Python 3.7 was released on June 27, 2018.  For full details, see the
*note changelog: 142.

* Menu:

* Summary – Release Highlights: Summary – Release Highlights<2>.
* New Features: New Features<10>.
* Other Language Changes: Other Language Changes<6>.
* New Modules: New Modules<6>.
* Improved Modules: Improved Modules<6>.
* C API Changes: C API Changes<5>.
* Build Changes: Build Changes<5>.
* Optimizations: Optimizations<7>.
* Other CPython Implementation Changes: Other CPython Implementation Changes<2>.
* Deprecated Python Behavior::
* Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods.
* Deprecated functions and types of the C API::
* Platform Support Removals::
* API and Feature Removals: API and Feature Removals<2>.
* Module Removals::
* Windows-only Changes::
* Porting to Python 3.7: Porting to Python 3 7.
* Notable changes in Python 3.7.1: Notable changes in Python 3 7 1.
* Notable changes in Python 3.7.2: Notable changes in Python 3 7 2.
* Notable changes in Python 3.7.6: Notable changes in Python 3 7 6.
* Notable changes in Python 3.7.10: Notable changes in Python 3 7 10.
* Notable changes in Python 3.7.11: Notable changes in Python 3 7 11.
* Notable security feature in 3.7.14: Notable security feature in 3 7 14.


File: python.info,  Node: Summary – Release Highlights<2>,  Next: New Features<10>,  Up: What’s New In Python 3 7

1.8.1 Summary – Release Highlights
----------------------------------

New syntax features:

   * *note PEP 563: cb8, postponed evaluation of type annotations.

Backwards incompatible syntax changes:

   * *note async: 93c. and *note await: 18d. are now reserved keywords.

New library modules:

   * *note contextvars: 28.: *note PEP 567 – Context Variables: cb9.

   * *note dataclasses: 33.: *note PEP 557 – Data Classes: cba.

   * *note importlib.resources: cbb.

New built-in features:

   * *note PEP 553: cbc, the new *note breakpoint(): 271. function.

Python data model improvements:

   * *note PEP 562: cbd, customization of access to module attributes.

   * *note PEP 560: cbe, core support for typing module and generic
     types.

   * the insertion-order preservation nature of *note dict: cbf. objects
     has been declared(1) to be an official part of the Python language
     spec.

Significant improvements in the standard library:

   * The *note asyncio: b. module has received new features, significant
     *note usability and performance improvements: cc0.

   * The *note time: f4. module gained support for *note functions with
     nanosecond resolution: cc1.

CPython implementation improvements:

   * Avoiding the use of ASCII as a default text encoding:

        * *note PEP 538: cc2, legacy C locale coercion

        * *note PEP 540: cc3, forced UTF-8 runtime mode

   * *note PEP 552: cc4, deterministic .pycs

   * *note New Python Development Mode: cc5.

   * *note PEP 565: cc6, improved *note DeprecationWarning: 1a3.
     handling

C API improvements:

   * *note PEP 539: cc7, new C API for thread-local storage

Documentation improvements:

   * *note PEP 545: cc8, Python documentation translations

   * New documentation translations: Japanese(2), French(3), and
     Korean(4).

This release features notable performance improvements in many areas.
The *note Optimizations: cc9. section lists them in detail.

For a list of changes that may affect compatibility with previous Python
releases please refer to the *note Porting to Python 3.7: cca. section.

   ---------- Footnotes ----------

   (1) 
https://mail.python.org/pipermail/python-dev/2017-December/151283.html

   (2) https://docs.python.org/ja/

   (3) https://docs.python.org/fr/

   (4) https://docs.python.org/ko/


File: python.info,  Node: New Features<10>,  Next: Other Language Changes<6>,  Prev: Summary – Release Highlights<2>,  Up: What’s New In Python 3 7

1.8.2 New Features
------------------

* Menu:

* PEP 563; Postponed Evaluation of Annotations: PEP 563 Postponed Evaluation of Annotations.
* PEP 538; Legacy C Locale Coercion: PEP 538 Legacy C Locale Coercion.
* PEP 540; Forced UTF-8 Runtime Mode: PEP 540 Forced UTF-8 Runtime Mode.
* PEP 553; Built-in breakpoint(): PEP 553 Built-in breakpoint.
* PEP 539; New C API for Thread-Local Storage: PEP 539 New C API for Thread-Local Storage.
* PEP 562; Customization of Access to Module Attributes: PEP 562 Customization of Access to Module Attributes.
* PEP 564; New Time Functions With Nanosecond Resolution: PEP 564 New Time Functions With Nanosecond Resolution.
* PEP 565; Show DeprecationWarning in __main__: PEP 565 Show DeprecationWarning in __main__.
* PEP 560; Core Support for typing module and Generic Types: PEP 560 Core Support for typing module and Generic Types.
* PEP 552; Hash-based .pyc Files: PEP 552 Hash-based pyc Files.
* PEP 545; Python Documentation Translations: PEP 545 Python Documentation Translations.
* Python Development Mode (-X dev): Python Development Mode -X dev.


File: python.info,  Node: PEP 563 Postponed Evaluation of Annotations,  Next: PEP 538 Legacy C Locale Coercion,  Up: New Features<10>

1.8.2.1 PEP 563: Postponed Evaluation of Annotations
....................................................

The advent of type hints in Python uncovered two glaring usability
issues with the functionality of annotations added in PEP 3107(1) and
refined further in PEP 526(2):

   * annotations could only use names which were already available in
     the current scope, in other words they didn’t support forward
     references of any kind; and

   * annotating source code had adverse effects on startup time of
     Python programs.

Both of these issues are fixed by postponing the evaluation of
annotations.  Instead of compiling code which executes expressions in
annotations at their definition time, the compiler stores the annotation
in a string form equivalent to the AST of the expression in question.
If needed, annotations can be resolved at runtime using *note
typing.get_type_hints(): 8c1.  In the common case where this is not
required, the annotations are cheaper to store (since short strings are
interned by the interpreter) and make startup time faster.

Usability-wise, annotations now support forward references, making the
following syntax valid:

     class C:
         @classmethod
         def from_string(cls, source: str) -> C:
             ...

         def validate_b(self, obj: B) -> bool:
             ...

     class B:
         ...

Since this change breaks compatibility, the new behavior needs to be
enabled on a per-module basis in Python 3.7 using a *note __future__: 0.
import:

     from __future__ import annotations

It will become the default in Python 3.10.

Vedi anche
..........

PEP 563(3) – Postponed evaluation of annotations

     PEP written and implemented by Łukasz Langa.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3107/

   (2) https://peps.python.org/pep-0526/

   (3) https://peps.python.org/pep-0563/


File: python.info,  Node: PEP 538 Legacy C Locale Coercion,  Next: PEP 540 Forced UTF-8 Runtime Mode,  Prev: PEP 563 Postponed Evaluation of Annotations,  Up: New Features<10>

1.8.2.2 PEP 538: Legacy C Locale Coercion
.........................................

An ongoing challenge within the Python 3 series has been determining a
sensible default strategy for handling the «7-bit ASCII» text encoding
assumption currently implied by the use of the default C or POSIX locale
on non-Windows platforms.

PEP 538(1) updates the default interpreter command line interface to
automatically coerce that locale to an available UTF-8 based locale as
described in the documentation of the new *note PYTHONCOERCECLOCALE:
cce. environment variable.  Automatically setting ‘LC_CTYPE’ this way
means that both the core interpreter and locale-aware C extensions (such
as *note readline: bf.) will assume the use of UTF-8 as the default text
encoding, rather than ASCII.

The platform support definition in PEP 11(2) has also been updated to
limit full text handling support to suitably configured non-ASCII based
locales.

As part of this change, the default error handler for *note stdin: 760.
and *note stdout: ccf. is now ‘surrogateescape’ (rather than ‘strict’)
when using any of the defined coercion target locales (currently
‘C.UTF-8’, ‘C.utf8’, and ‘UTF-8’).  The default error handler for *note
stderr: b35. continues to be ‘backslashreplace’, regardless of locale.

Locale coercion is silent by default, but to assist in debugging
potentially locale related integration problems, explicit warnings
(emitted directly on *note stderr: b35.) can be requested by setting
‘PYTHONCOERCECLOCALE=warn’.  This setting will also cause the Python
runtime to emit a warning if the legacy C locale remains active when the
core interpreter is initialized.

While PEP 538(3)’s locale coercion has the benefit of also affecting
extension modules (such as GNU ‘readline’), as well as child processes
(including those running non-Python applications and older versions of
Python), it has the downside of requiring that a suitable target locale
be present on the running system.  To better handle the case where no
suitable target locale is available (as occurs on RHEL/CentOS 7, for
example), Python 3.7 also implements *note PEP 540; Forced UTF-8 Runtime
Mode: cc3.

Vedi anche
..........

PEP 538(4) – Coercing the legacy C locale to a UTF-8 based locale

     PEP written and implemented by Nick Coghlan.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0538/

   (2) https://peps.python.org/pep-0011/

   (3) https://peps.python.org/pep-0538/

   (4) https://peps.python.org/pep-0538/


File: python.info,  Node: PEP 540 Forced UTF-8 Runtime Mode,  Next: PEP 553 Built-in breakpoint,  Prev: PEP 538 Legacy C Locale Coercion,  Up: New Features<10>

1.8.2.3 PEP 540: Forced UTF-8 Runtime Mode
..........................................

The new *note -X: 16f. ‘utf8’ command line option and *note PYTHONUTF8:
cd1. environment variable can be used to enable the *note Python UTF-8
Mode: 867.

When in UTF-8 mode, CPython ignores the locale settings, and uses the
UTF-8 encoding by default.  The error handlers for *note sys.stdin: 760.
and *note sys.stdout: ccf. streams are set to ‘surrogateescape’.

The forced UTF-8 mode can be used to change the text handling behavior
in an embedded Python interpreter without changing the locale settings
of an embedding application.

While PEP 540(1)’s UTF-8 mode has the benefit of working regardless of
which locales are available on the running system, it has the downside
of having no effect on extension modules (such as GNU ‘readline’), child
processes running non-Python applications, and child processes running
older versions of Python.  To reduce the risk of corrupting text data
when communicating with such components, Python 3.7 also implements
*note PEP 540; Forced UTF-8 Runtime Mode: cc3.).

The UTF-8 mode is enabled by default when the locale is ‘C’ or ‘POSIX’,
and the PEP 538(2) locale coercion feature fails to change it to a UTF-8
based alternative (whether that failure is due to
‘PYTHONCOERCECLOCALE=0’ being set, ‘LC_ALL’ being set, or the lack of a
suitable target locale).

Vedi anche
..........

PEP 540(3) – Add a new UTF-8 mode

     PEP written and implemented by Victor Stinner

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0540/

   (2) https://peps.python.org/pep-0538/

   (3) https://peps.python.org/pep-0540/


File: python.info,  Node: PEP 553 Built-in breakpoint,  Next: PEP 539 New C API for Thread-Local Storage,  Prev: PEP 540 Forced UTF-8 Runtime Mode,  Up: New Features<10>

1.8.2.4 PEP 553: Built-in ‘breakpoint()’
........................................

Python 3.7 includes the new built-in *note breakpoint(): 271. function
as an easy and consistent way to enter the Python debugger.

Built-in ‘breakpoint()’ calls *note sys.breakpointhook(): cd3.  By
default, the latter imports *note pdb: aa. and then calls
‘pdb.set_trace()’, but by binding ‘sys.breakpointhook()’ to the function
of your choosing, ‘breakpoint()’ can enter any debugger.  Additionally,
the environment variable *note PYTHONBREAKPOINT: cd4. can be set to the
callable of your debugger of choice.  Set ‘PYTHONBREAKPOINT=0’ to
completely disable built-in ‘breakpoint()’.

Vedi anche
..........

PEP 553(1) – Built-in breakpoint()

     PEP written and implemented by Barry Warsaw

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0553/


File: python.info,  Node: PEP 539 New C API for Thread-Local Storage,  Next: PEP 562 Customization of Access to Module Attributes,  Prev: PEP 553 Built-in breakpoint,  Up: New Features<10>

1.8.2.5 PEP 539: New C API for Thread-Local Storage
...................................................

While Python provides a C API for thread-local storage support; the
existing *note Thread Local Storage (TLS) API: cd6. has used int to
represent TLS keys across all platforms.  This has not generally been a
problem for officially support platforms, but that is neither
POSIX-compliant, nor portable in any practical sense.

PEP 539(1) changes this by providing a new *note Thread Specific Storage
(TSS) API: cd7. to CPython which supersedes use of the existing TLS API
within the CPython interpreter, while deprecating the existing API. The
TSS API uses a new type *note Py_tss_t: cd8. instead of int to represent
TSS keys–an opaque type the definition of which may depend on the
underlying TLS implementation.  Therefore, this will allow to build
CPython on platforms where the native TLS key is defined in a way that
cannot be safely cast to int.

Note that on platforms where the native TLS key is defined in a way that
cannot be safely cast to int, all functions of the existing TLS API will
be no-op and immediately return failure.  This indicates clearly that
the old API is not supported on platforms where it cannot be used
reliably, and that no effort will be made to add such support.

Vedi anche
..........

PEP 539(2) – A New C-API for Thread-Local Storage in CPython

     PEP written by Erik M. Bray; implementation by Masayuki Yamamoto.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0539/

   (2) https://peps.python.org/pep-0539/


File: python.info,  Node: PEP 562 Customization of Access to Module Attributes,  Next: PEP 564 New Time Functions With Nanosecond Resolution,  Prev: PEP 539 New C API for Thread-Local Storage,  Up: New Features<10>

1.8.2.6 PEP 562: Customization of Access to Module Attributes
.............................................................

Python 3.7 allows defining *note __getattr__(): cda. on modules and will
call it whenever a module attribute is otherwise not found.  Defining
*note __dir__(): cdb. on modules is now also allowed.

A typical example of where this may be useful is module attribute
deprecation and lazy loading.

Vedi anche
..........

PEP 562(1) – Module ‘__getattr__’ and ‘__dir__’

     PEP written and implemented by Ivan Levkivskyi

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0562/


File: python.info,  Node: PEP 564 New Time Functions With Nanosecond Resolution,  Next: PEP 565 Show DeprecationWarning in __main__,  Prev: PEP 562 Customization of Access to Module Attributes,  Up: New Features<10>

1.8.2.7 PEP 564: New Time Functions With Nanosecond Resolution
..............................................................

The resolution of clocks in modern systems can exceed the limited
precision of a floating-point number returned by the *note time.time():
55d. function and its variants.  To avoid loss of precision, PEP 564(1)
adds six new «nanosecond» variants of the existing timer functions to
the *note time: f4. module:

   * *note time.clock_gettime_ns(): cdd.

   * *note time.clock_settime_ns(): cde.

   * *note time.monotonic_ns(): cdf.

   * *note time.perf_counter_ns(): ce0.

   * *note time.process_time_ns(): ce1.

   * *note time.time_ns(): ce2.

The new functions return the number of nanoseconds as an integer value.

Measurements(2) show that on Linux and Windows the resolution of *note
time.time_ns(): ce2. is approximately 3 times better than that of *note
time.time(): 55d.

Vedi anche
..........

PEP 564(3) – Add new time functions with nanosecond resolution

     PEP written and implemented by Victor Stinner

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0564/

   (2) 
https://peps.python.org/pep-0564/#annex-clocks-resolution-in-python

   (3) https://peps.python.org/pep-0564/


File: python.info,  Node: PEP 565 Show DeprecationWarning in __main__,  Next: PEP 560 Core Support for typing module and Generic Types,  Prev: PEP 564 New Time Functions With Nanosecond Resolution,  Up: New Features<10>

1.8.2.8 PEP 565: Show DeprecationWarning in ‘__main__’
......................................................

The default handling of *note DeprecationWarning: 1a3. has been changed
such that these warnings are once more shown by default, but only when
the code triggering them is running directly in the *note __main__: 1.
module.  As a result, developers of single file scripts and those using
Python interactively should once again start seeing deprecation warnings
for the APIs they use, but deprecation warnings triggered by imported
application, library and framework modules will continue to be hidden by
default.

As a result of this change, the standard library now allows developers
to choose between three different deprecation warning behaviours:

   * *note FutureWarning: 659.: always displayed by default, recommended
     for warnings intended to be seen by application end users (e.g.
     for deprecated application configuration settings).

   * *note DeprecationWarning: 1a3.: displayed by default only in *note
     __main__: 1. and when running tests, recommended for warnings
     intended to be seen by other Python developers where a version
     upgrade may result in changed behaviour or an error.

   * *note PendingDeprecationWarning: ac8.: displayed by default only
     when running tests, intended for cases where a future version
     upgrade will change the warning category to *note
     DeprecationWarning: 1a3. or *note FutureWarning: 659.

Previously both *note DeprecationWarning: 1a3. and *note
PendingDeprecationWarning: ac8. were only visible when running tests,
which meant that developers primarily writing single file scripts or
using Python interactively could be surprised by breaking changes in the
APIs they used.

Vedi anche
..........

PEP 565(1) – Show DeprecationWarning in ‘__main__’

     PEP written and implemented by Nick Coghlan

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0565/


File: python.info,  Node: PEP 560 Core Support for typing module and Generic Types,  Next: PEP 552 Hash-based pyc Files,  Prev: PEP 565 Show DeprecationWarning in __main__,  Up: New Features<10>

1.8.2.9 PEP 560: Core Support for ‘typing’ module and Generic Types
...................................................................

Initially PEP 484(1) was designed in such way that it would not
introduce 'any' changes to the core CPython interpreter.  Now type hints
and the *note typing: 10a. module are extensively used by the community,
so this restriction is removed.  The PEP introduces two special methods
*note __class_getitem__(): 944. and *note __mro_entries__(): ce5, these
methods are now used by most classes and special constructs in *note
typing: 10a.  As a result, the speed of various operations with types
increased up to 7 times, the generic types can be used without metaclass
conflicts, and several long standing bugs in *note typing: 10a. module
are fixed.

Vedi anche
..........

PEP 560(2) – Core support for typing module and generic types

     PEP written and implemented by Ivan Levkivskyi

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0560/


File: python.info,  Node: PEP 552 Hash-based pyc Files,  Next: PEP 545 Python Documentation Translations,  Prev: PEP 560 Core Support for typing module and Generic Types,  Up: New Features<10>

1.8.2.10 PEP 552: Hash-based .pyc Files
.......................................

Python has traditionally checked the up-to-dateness of bytecode cache
files (i.e., ‘.pyc’ files) by comparing the source metadata
(last-modified timestamp and size) with source metadata saved in the
cache file header when it was generated.  While effective, this
invalidation method has its drawbacks.  When filesystem timestamps are
too coarse, Python can miss source updates, leading to user confusion.
Additionally, having a timestamp in the cache file is problematic for
build reproducibility(1) and content-based build systems.

PEP 552(2) extends the pyc format to allow the hash of the source file
to be used for invalidation instead of the source timestamp.  Such
‘.pyc’ files are called «hash-based».  By default, Python still uses
timestamp-based invalidation and does not generate hash-based ‘.pyc’
files at runtime.  Hash-based ‘.pyc’ files may be generated with *note
py_compile: b8. or *note compileall: 21.

Hash-based ‘.pyc’ files come in two variants: checked and unchecked.
Python validates checked hash-based ‘.pyc’ files against the
corresponding source files at runtime but doesn’t do so for unchecked
hash-based pycs.  Unchecked hash-based ‘.pyc’ files are a useful
performance optimization for environments where a system external to
Python (e.g., the build system) is responsible for keeping ‘.pyc’ files
up-to-date.

See *note Cached bytecode invalidation: 803. for more information.

Vedi anche
..........

PEP 552(3) – Deterministic pycs

     PEP written and implemented by Benjamin Peterson

   ---------- Footnotes ----------

   (1) https://reproducible-builds.org/

   (2) https://peps.python.org/pep-0552/

   (3) https://peps.python.org/pep-0552/


File: python.info,  Node: PEP 545 Python Documentation Translations,  Next: Python Development Mode -X dev,  Prev: PEP 552 Hash-based pyc Files,  Up: New Features<10>

1.8.2.11 PEP 545: Python Documentation Translations
...................................................

PEP 545(1) describes the process of creating and maintaining Python
documentation translations.

Three new translations have been added:

   - Japanese: ‘https://docs.python.org/ja/’

   - French: ‘https://docs.python.org/fr/’

   - Korean: ‘https://docs.python.org/ko/’

Vedi anche
..........

PEP 545(2) – Python Documentation Translations

     PEP written and implemented by Julien Palard, Inada Naoki, and
     Victor Stinner.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0545/

   (2) https://peps.python.org/pep-0545/


File: python.info,  Node: Python Development Mode -X dev,  Prev: PEP 545 Python Documentation Translations,  Up: New Features<10>

1.8.2.12 Python Development Mode (-X dev)
.........................................

The new *note -X: 16f. ‘dev’ command line option or the new *note
PYTHONDEVMODE: ce9. environment variable can be used to enable *note
Python Development Mode: 509.  When in development mode, Python performs
additional runtime checks that are too expensive to be enabled by
default.  See *note Python Development Mode: 509. documentation for the
full description.


File: python.info,  Node: Other Language Changes<6>,  Next: New Modules<6>,  Prev: New Features<10>,  Up: What’s New In Python 3 7

1.8.3 Other Language Changes
----------------------------

   * An *note await: 18d. expression and comprehensions containing an
     *note async for: ca3. clause were illegal in the expressions in
     *note formatted string literals: 19a. due to a problem with the
     implementation.  In Python 3.7 this restriction was lifted.

   * More than 255 arguments can now be passed to a function, and a
     function can now have more than 255 parameters.  (Contributed by
     Serhiy Storchaka in bpo-12844(1) and bpo-18896(2).)

   * *note bytes.fromhex(): 190. and *note bytearray.fromhex(): 191. now
     ignore all ASCII whitespace, not only spaces.  (Contributed by
     Robert Xiao in bpo-28927(3).)

   * *note str: 169, *note bytes: 192, and *note bytearray: 344. gained
     support for the new *note isascii(): ceb. method, which can be used
     to test if a string or bytes contain only the ASCII characters.
     (Contributed by INADA Naoki in bpo-32677(4).)

   * *note ImportError: 65b. now displays module name and module
     ‘__file__’ path when ‘from ... import ...’ fails.  (Contributed by
     Matthias Bussonnier in bpo-29546(5).)

   * Circular imports involving absolute imports with binding a
     submodule to a name are now supported.  (Contributed by Serhiy
     Storchaka in bpo-30024(6).)

   * ‘object.__format__(x, '')’ is now equivalent to ‘str(x)’ rather
     than ‘format(str(self), '')’.  (Contributed by Serhiy Storchaka in
     bpo-28974(7).)

   * In order to better support dynamic creation of stack traces, *note
     types.TracebackType: cec. can now be instantiated from Python code,
     and the *note tb_next: ced. attribute on *note tracebacks: cee. is
     now writable.  (Contributed by Nathaniel J. Smith in bpo-30579(8).)

   * When using the *note -m: 23c. switch, ‘sys.path[0]’ is now eagerly
     expanded to the full starting directory path, rather than being
     left as the empty directory (which allows imports from the
     'current' working directory at the time when an import occurs)
     (Contributed by Nick Coghlan in bpo-33053(9).)

   * The new *note -X: 16f. ‘importtime’ option or the *note
     PYTHONPROFILEIMPORTTIME: cef. environment variable can be used to
     show the timing of each module import.  (Contributed by Inada Naoki
     in bpo-31415(10).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12844

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18896

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28927

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32677

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29546

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30024

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28974

   (8) https://bugs.python.org/issue?@action=redirect&bpo=30579

   (9) https://bugs.python.org/issue?@action=redirect&bpo=33053

   (10) https://bugs.python.org/issue?@action=redirect&bpo=31415


File: python.info,  Node: New Modules<6>,  Next: Improved Modules<6>,  Prev: Other Language Changes<6>,  Up: What’s New In Python 3 7

1.8.4 New Modules
-----------------

* Menu:

* contextvars: contextvars<2>.
* dataclasses: dataclasses<3>.
* importlib.resources: importlib resources<2>.


File: python.info,  Node: contextvars<2>,  Next: dataclasses<3>,  Up: New Modules<6>

1.8.4.1 contextvars
...................

The new *note contextvars: 28. module and a set of *note new C APIs:
cf2. introduce support for 'context variables'.  Context variables are
conceptually similar to thread-local variables.  Unlike TLS, context
variables support asynchronous code correctly.

The *note asyncio: b. and *note decimal: 3a. modules have been updated
to use and support context variables out of the box.  Particularly the
active decimal context is now stored in a context variable, which allows
decimal operations to work with the correct context in asynchronous
code.

Vedi anche
..........

PEP 567(1) – Context Variables

     PEP written and implemented by Yury Selivanov

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0567/


File: python.info,  Node: dataclasses<3>,  Next: importlib resources<2>,  Prev: contextvars<2>,  Up: New Modules<6>

1.8.4.2 dataclasses
...................

The new *note dataclass(): 4e2. decorator provides a way to declare
'data classes'.  A data class describes its attributes using class
variable annotations.  Its constructor and other magic methods, such as
*note __repr__(): 830, *note __eq__(): cf4, and *note __hash__(): cf5.
are generated automatically.

Example:

     @dataclass
     class Point:
         x: float
         y: float
         z: float = 0.0

     p = Point(1.5, 2.5)
     print(p)   # produces "Point(x=1.5, y=2.5, z=0.0)"

Vedi anche
..........

PEP 557(1) – Data Classes

     PEP written and implemented by Eric V. Smith

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0557/


File: python.info,  Node: importlib resources<2>,  Prev: dataclasses<3>,  Up: New Modules<6>

1.8.4.3 importlib.resources
...........................

The new *note importlib.resources: 7f. module provides several new APIs
and one new ABC for access to, opening, and reading 'resources' inside
packages.  Resources are roughly similar to files inside packages, but
they needn’t be actual files on the physical file system.  Module
loaders can provide a ‘get_resource_reader()’ function which returns a
‘importlib.abc.ResourceReader’ instance to support this new API.
Built-in file path loaders and zip file loaders both support this.

Contributed by Barry Warsaw and Brett Cannon in bpo-32248(1).

Vedi anche
..........

importlib_resources(2) – a PyPI backport for earlier Python versions.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32248

   (2) https://importlib-resources.readthedocs.io/en/latest/


File: python.info,  Node: Improved Modules<6>,  Next: C API Changes<5>,  Prev: New Modules<6>,  Up: What’s New In Python 3 7

1.8.5 Improved Modules
----------------------

* Menu:

* argparse: argparse<5>.
* asyncio: asyncio<10>.
* binascii::
* calendar: calendar<3>.
* collections: collections<2>.
* compileall: compileall<3>.
* concurrent.futures: concurrent futures<4>.
* contextlib: contextlib<3>.
* cProfile: cProfile<2>.
* crypt::
* datetime: datetime<5>.
* dbm: dbm<2>.
* decimal: decimal<2>.
* dis: dis<4>.
* distutils: distutils<4>.
* enum: enum<5>.
* functools: functools<4>.
* gc: gc<5>.
* hmac: hmac<3>.
* http.client: http client.
* http.server: http server.
* idlelib and IDLE::
* importlib: importlib<4>.
* io: io<6>.
* ipaddress: ipaddress<3>.
* itertools: itertools<6>.
* locale: locale<4>.
* logging: logging<3>.
* math: math<6>.
* mimetypes: mimetypes<3>.
* msilib::
* multiprocessing: multiprocessing<5>.
* os: os<8>.
* pathlib: pathlib<11>.
* pdb: pdb<6>.
* py_compile: py_compile<3>.
* pydoc: pydoc<3>.
* queue: queue<2>.
* re: re<5>.
* signal: signal<2>.
* socket: socket<6>.
* socketserver::
* sqlite3: sqlite3<7>.
* ssl: ssl<6>.
* string: string<2>.
* subprocess: subprocess<2>.
* sys: sys<8>.
* time: time<5>.
* tkinter: tkinter<6>.
* tracemalloc: tracemalloc<2>.
* types: types<5>.
* unicodedata: unicodedata<7>.
* unittest: unittest<8>.
* unittest.mock: unittest mock.
* urllib.parse: urllib parse<5>.
* uu::
* uuid: uuid<4>.
* warnings: warnings<3>.
* xml: xml<5>.
* xml.etree: xml etree.
* xmlrpc.server: xmlrpc server.
* zipapp::
* zipfile: zipfile<3>.


File: python.info,  Node: argparse<5>,  Next: asyncio<10>,  Up: Improved Modules<6>

1.8.5.1 argparse
................

The new *note ArgumentParser.parse_intermixed_args(): cf9. method allows
intermixing options and positional arguments.  (Contributed by paul.j3
in bpo-14191(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14191


File: python.info,  Node: asyncio<10>,  Next: binascii,  Prev: argparse<5>,  Up: Improved Modules<6>

1.8.5.2 asyncio
...............

The *note asyncio: b. module has received many new features, usability
and *note performance improvements: cfb.  Notable changes include:

   * The new *note provisional: 3d1. *note asyncio.run(): 2f3. function
     can be used to run a coroutine from synchronous code by
     automatically creating and destroying the event loop.  (Contributed
     by Yury Selivanov in bpo-32314(1).)

   * asyncio gained support for *note contextvars: 28.  *note
     loop.call_soon(): cfc, *note loop.call_soon_threadsafe(): cfd,
     *note loop.call_later(): cfe, *note loop.call_at(): cff, and *note
     Future.add_done_callback(): d00. have a new optional keyword-only
     'context' parameter.  *note Tasks: 1c7. now track their context
     automatically.  See PEP 567(2) for more details.  (Contributed by
     Yury Selivanov in bpo-32436(3).)

   * The new *note asyncio.create_task(): 1c9. function has been added
     as a shortcut to ‘asyncio.get_event_loop().create_task()’.
     (Contributed by Andrew Svetlov in bpo-32311(4).)

   * The new *note loop.start_tls(): d01. method can be used to upgrade
     an existing connection to TLS. (Contributed by Yury Selivanov in
     bpo-23749(5).)

   * The new *note loop.sock_recv_into(): d02. method allows reading
     data from a socket directly into a provided buffer making it
     possible to reduce data copies.  (Contributed by Antoine Pitrou in
     bpo-31819(6).)

   * The new *note asyncio.current_task(): 6a6. function returns the
     currently running *note Task: 1c7. instance, and the new *note
     asyncio.all_tasks(): b51. function returns a set of all existing
     ‘Task’ instances in a given loop.  The ‘Task.current_task()’ and
     ‘Task.all_tasks()’ methods have been deprecated.  (Contributed by
     Andrew Svetlov in bpo-32250(7).)

   * The new 'provisional' *note BufferedProtocol: c96. class allows
     implementing streaming protocols with manual control over the
     receive buffer.  (Contributed by Yury Selivanov in bpo-32251(8).)

   * The new *note asyncio.get_running_loop(): d03. function returns the
     currently running loop, and raises a *note RuntimeError: 244. if no
     loop is running.  This is in contrast with *note
     asyncio.get_event_loop(): 2f2, which will 'create' a new event loop
     if none is running.  (Contributed by Yury Selivanov in
     bpo-32269(9).)

   * The new *note StreamWriter.wait_closed(): d04. coroutine method
     allows waiting until the stream writer is closed.  The new *note
     StreamWriter.is_closing(): d05. method can be used to determine if
     the writer is closing.  (Contributed by Andrew Svetlov in
     bpo-32391(10).)

   * The new *note loop.sock_sendfile(): d06. coroutine method allows
     sending files using *note os.sendfile: d07. when possible.
     (Contributed by Andrew Svetlov in bpo-32410(11).)

   * The new *note Future.get_loop(): d08. and ‘Task.get_loop()’ methods
     return the instance of the loop on which a task or a future were
     created.  *note Server.get_loop(): d09. allows doing the same for
     *note asyncio.Server: d0a. objects.  (Contributed by Yury Selivanov
     in bpo-32415(12) and Srinivas Reddy Thatiparthy in bpo-32418(13).)

   * It is now possible to control how instances of *note
     asyncio.Server: d0a. begin serving.  Previously, the server would
     start serving immediately when created.  The new 'start_serving'
     keyword argument to *note loop.create_server(): d0b. and *note
     loop.create_unix_server(): 4cb, as well as *note
     Server.start_serving(): d0c, and *note Server.serve_forever(): d0d.
     can be used to decouple server instantiation and serving.  The new
     *note Server.is_serving(): d0e. method returns ‘True’ if the server
     is serving.  *note Server: d0a. objects are now asynchronous
     context managers:

          srv = await loop.create_server(...)

          async with srv:
              # some code

          # At this point, srv is closed and no longer accepts new connections.

     (Contributed by Yury Selivanov in bpo-32662(14).)

   * Callback objects returned by *note loop.call_later(): cfe. gained
     the new *note when(): d0f. method which returns an absolute
     scheduled callback timestamp.  (Contributed by Andrew Svetlov in
     bpo-32741(15).)

   * The *note loop.create_datagram_endpoint(): 93d. method gained
     support for Unix sockets.  (Contributed by Quentin Dawans in
     bpo-31245(16).)

   * The *note asyncio.open_connection(): d10, *note
     asyncio.start_server(): d11. functions, *note
     loop.create_connection(): 819, *note loop.create_server(): d0b,
     *note loop.create_accepted_socket(): 9e0. methods and their
     corresponding UNIX socket variants now accept the
     'ssl_handshake_timeout' keyword argument.  (Contributed by Neil
     Aspinall in bpo-29970(17).)

   * The new *note Handle.cancelled(): d12. method returns ‘True’ if the
     callback was cancelled.  (Contributed by Marat Sharafutdinov in
     bpo-31943(18).)

   * The asyncio source has been converted to use the *note async:
     93c./*note await: 18d. syntax.  (Contributed by Andrew Svetlov in
     bpo-32193(19).)

   * The new *note ReadTransport.is_reading(): d13. method can be used
     to determine the reading state of the transport.  Additionally,
     calls to *note ReadTransport.resume_reading(): d14. and *note
     ReadTransport.pause_reading(): d15. are now idempotent.
     (Contributed by Yury Selivanov in bpo-32356(20).)

   * Loop methods which accept socket paths now support passing *note
     path-like objects: 5a1.  (Contributed by Yury Selivanov in
     bpo-32066(21).)

   * In *note asyncio: b. TCP sockets on Linux are now created with
     ‘TCP_NODELAY’ flag set by default.  (Contributed by Yury Selivanov
     and Victor Stinner in bpo-27456(22).)

   * Exceptions occurring in cancelled tasks are no longer logged.
     (Contributed by Yury Selivanov in bpo-30508(23).)

   * New ‘WindowsSelectorEventLoopPolicy’ and
     ‘WindowsProactorEventLoopPolicy’ classes.  (Contributed by Yury
     Selivanov in bpo-33792(24).)

Several ‘asyncio’ APIs have been *note deprecated: d16.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32314

   (2) https://peps.python.org/pep-0567/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32436

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32311

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23749

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31819

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32250

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32251

   (9) https://bugs.python.org/issue?@action=redirect&bpo=32269

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32391

   (11) https://bugs.python.org/issue?@action=redirect&bpo=32410

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32415

   (13) https://bugs.python.org/issue?@action=redirect&bpo=32418

   (14) https://bugs.python.org/issue?@action=redirect&bpo=32662

   (15) https://bugs.python.org/issue?@action=redirect&bpo=32741

   (16) https://bugs.python.org/issue?@action=redirect&bpo=31245

   (17) https://bugs.python.org/issue?@action=redirect&bpo=29970

   (18) https://bugs.python.org/issue?@action=redirect&bpo=31943

   (19) https://bugs.python.org/issue?@action=redirect&bpo=32193

   (20) https://bugs.python.org/issue?@action=redirect&bpo=32356

   (21) https://bugs.python.org/issue?@action=redirect&bpo=32066

   (22) https://bugs.python.org/issue?@action=redirect&bpo=27456

   (23) https://bugs.python.org/issue?@action=redirect&bpo=30508

   (24) https://bugs.python.org/issue?@action=redirect&bpo=33792


File: python.info,  Node: binascii,  Next: calendar<3>,  Prev: asyncio<10>,  Up: Improved Modules<6>

1.8.5.3 binascii
................

The *note b2a_uu(): d18. function now accepts an optional 'backtick'
keyword argument.  When it’s true, zeros are represented by ‘'`'’
instead of spaces.  (Contributed by Xiang Zhang in bpo-30103(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30103


File: python.info,  Node: calendar<3>,  Next: collections<2>,  Prev: binascii,  Up: Improved Modules<6>

1.8.5.4 calendar
................

The *note HTMLCalendar: d1a. class has new class attributes which ease
the customization of CSS classes in the produced HTML calendar.
(Contributed by Oz Tiram in bpo-30095(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30095


File: python.info,  Node: collections<2>,  Next: compileall<3>,  Prev: calendar<3>,  Up: Improved Modules<6>

1.8.5.5 collections
...................

‘collections.namedtuple()’ now supports default values.  (Contributed by
Raymond Hettinger in bpo-32320(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32320


File: python.info,  Node: compileall<3>,  Next: concurrent futures<4>,  Prev: collections<2>,  Up: Improved Modules<6>

1.8.5.6 compileall
..................

*note compileall.compile_dir(): d1d. learned the new 'invalidation_mode'
parameter, which can be used to enable *note hash-based .pyc
invalidation: cc4.  The invalidation mode can also be specified on the
command line using the new ‘--invalidation-mode’ argument.  (Contributed
by Benjamin Peterson in bpo-31650(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31650


File: python.info,  Node: concurrent futures<4>,  Next: contextlib<3>,  Prev: compileall<3>,  Up: Improved Modules<6>

1.8.5.7 concurrent.futures
..........................

*note ProcessPoolExecutor: 1d6. and *note ThreadPoolExecutor: 94a. now
support the new 'initializer' and 'initargs' constructor arguments.
(Contributed by Antoine Pitrou in bpo-21423(1).)

The *note ProcessPoolExecutor: 1d6. can now take the multiprocessing
context via the new 'mp_context' argument.  (Contributed by Thomas
Moreau in bpo-31540(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21423

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31540


File: python.info,  Node: contextlib<3>,  Next: cProfile<2>,  Prev: concurrent futures<4>,  Up: Improved Modules<6>

1.8.5.8 contextlib
..................

The new *note nullcontext(): 9f1. is a simpler and faster no-op context
manager than *note ExitStack: d20.  (Contributed by Jesse-Bakker in
bpo-10049(1).)

The new *note asynccontextmanager(): d21, *note
AbstractAsyncContextManager: d22, and *note AsyncExitStack: d23. have
been added to complement their synchronous counterparts.  (Contributed
by Jelle Zijlstra in bpo-29679(2) and bpo-30241(3), and by Alexander
Mohr and Ilya Kulakov in bpo-29302(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10049

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29679

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30241

   (4) https://bugs.python.org/issue?@action=redirect&bpo=29302


File: python.info,  Node: cProfile<2>,  Next: crypt,  Prev: contextlib<3>,  Up: Improved Modules<6>

1.8.5.9 cProfile
................

The *note cProfile: 2b. command line now accepts ‘-m module_name’ as an
alternative to script path.  (Contributed by Sanyam Khurana in
bpo-21862(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21862


File: python.info,  Node: crypt,  Next: datetime<5>,  Prev: cProfile<2>,  Up: Improved Modules<6>

1.8.5.10 crypt
..............

The ‘crypt’ module now supports the Blowfish hashing method.
(Contributed by Serhiy Storchaka in bpo-31664(1).)

The ‘mksalt()’ function now allows specifying the number of rounds for
hashing.  (Contributed by Serhiy Storchaka in bpo-31702(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31664

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31702


File: python.info,  Node: datetime<5>,  Next: dbm<2>,  Prev: crypt,  Up: Improved Modules<6>

1.8.5.11 datetime
.................

The new *note datetime.fromisoformat(): 82b. method constructs a *note
datetime: 4e3. object from a string in one of the formats output by
*note datetime.isoformat(): d27.  (Contributed by Paul Ganssle in
bpo-15873(1).)

The *note tzinfo: 7f7. class now supports sub-minute offsets.
(Contributed by Alexander Belopolsky in bpo-5288(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15873

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5288


File: python.info,  Node: dbm<2>,  Next: decimal<2>,  Prev: datetime<5>,  Up: Improved Modules<6>

1.8.5.12 dbm
............

*note dbm.dumb: 36. now supports reading read-only files and no longer
writes the index file when it is not changed.


File: python.info,  Node: decimal<2>,  Next: dis<4>,  Prev: dbm<2>,  Up: Improved Modules<6>

1.8.5.13 decimal
................

The *note decimal: 3a. module now uses *note context variables: cb9. to
store the decimal context.  (Contributed by Yury Selivanov in
bpo-32630(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32630


File: python.info,  Node: dis<4>,  Next: distutils<4>,  Prev: decimal<2>,  Up: Improved Modules<6>

1.8.5.14 dis
............

The *note dis(): 205. function is now able to disassemble nested code
objects (the code of comprehensions, generator expressions and nested
functions, and the code used for building nested classes).  The maximum
depth of disassembly recursion is controlled by the new 'depth'
parameter.  (Contributed by Serhiy Storchaka in bpo-11822(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11822


File: python.info,  Node: distutils<4>,  Next: enum<5>,  Prev: dis<4>,  Up: Improved Modules<6>

1.8.5.15 distutils
..................

‘README.rst’ is now included in the list of distutils standard READMEs
and therefore included in source distributions.  (Contributed by Ryan
Gonzalez in bpo-11913(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11913


File: python.info,  Node: enum<5>,  Next: functools<4>,  Prev: distutils<4>,  Up: Improved Modules<6>

1.8.5.16 enum
.............

The *note Enum: 843. learned the new ‘_ignore_’ class property, which
allows listing the names of properties which should not become enum
members.  (Contributed by Ethan Furman in bpo-31801(1).)

In Python 3.8, attempting to check for non-Enum objects in *note Enum:
843. classes will raise a *note TypeError: 198. (e.g.  ‘1 in Color’);
similarly, attempting to check for non-Flag objects in a *note Flag:
836. member will raise *note TypeError: 198. (e.g.  ‘1 in Perm.RW’);
currently, both operations return *note False: d2d. instead and are
deprecated.  (Contributed by Ethan Furman in bpo-33217(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31801

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33217


File: python.info,  Node: functools<4>,  Next: gc<5>,  Prev: enum<5>,  Up: Improved Modules<6>

1.8.5.17 functools
..................

*note functools.singledispatch(): 84c. now supports registering
implementations using type annotations.  (Contributed by Łukasz Langa in
bpo-32227(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32227


File: python.info,  Node: gc<5>,  Next: hmac<3>,  Prev: functools<4>,  Up: Improved Modules<6>

1.8.5.18 gc
...........

The new *note gc.freeze(): d30. function allows freezing all objects
tracked by the garbage collector and excluding them from future
collections.  This can be used before a POSIX ‘fork()’ call to make the
GC copy-on-write friendly or to speed up collection.  The new *note
gc.unfreeze(): d31. functions reverses this operation.  Additionally,
*note gc.get_freeze_count(): d32. can be used to obtain the number of
frozen objects.  (Contributed by Li Zekun in bpo-31558(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31558


File: python.info,  Node: hmac<3>,  Next: http client,  Prev: gc<5>,  Up: Improved Modules<6>

1.8.5.19 hmac
.............

The *note hmac: 6e. module now has an optimized one-shot *note digest():
d34. function, which is up to three times faster than *note HMAC(): d35.
(Contributed by Christian Heimes in bpo-32433(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32433


File: python.info,  Node: http client,  Next: http server,  Prev: hmac<3>,  Up: Improved Modules<6>

1.8.5.20 http.client
....................

*note HTTPConnection: d37. and *note HTTPSConnection: d38. now support
the new 'blocksize' argument for improved upload throughput.
(Contributed by Nir Soffer in bpo-31945(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31945


File: python.info,  Node: http server,  Next: idlelib and IDLE,  Prev: http client,  Up: Improved Modules<6>

1.8.5.21 http.server
....................

*note SimpleHTTPRequestHandler: d3a. now supports the HTTP
‘If-Modified-Since’ header.  The server returns the 304 response status
if the target file was not modified after the time specified in the
header.  (Contributed by Pierre Quentel in bpo-29654(1).)

*note SimpleHTTPRequestHandler: d3a. accepts the new 'directory'
argument, in addition to the new ‘--directory’ command line argument.
With this parameter, the server serves the specified directory, by
default it uses the current working directory.  (Contributed by Stéphane
Wirtel and Julien Palard in bpo-28707(2).)

The new *note ThreadingHTTPServer: d3b. class uses threads to handle
requests using *note ThreadingMixIn: d3c.  It is used when ‘http.server’
is run with ‘-m’.  (Contributed by Julien Palard in bpo-31639(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29654

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28707

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31639


File: python.info,  Node: idlelib and IDLE,  Next: importlib<4>,  Prev: http server,  Up: Improved Modules<6>

1.8.5.22 idlelib and IDLE
.........................

Multiple fixes for autocompletion.  (Contributed by Louie Lu in
bpo-15786(1).)

Module Browser (on the File menu, formerly called Class Browser), now
displays nested functions and classes in addition to top-level functions
and classes.  (Contributed by Guilherme Polo, Cheryl Sabella, and Terry
Jan Reedy in bpo-1612262(2).)

The Settings dialog (Options, Configure IDLE) has been partly rewritten
to improve both appearance and function.  (Contributed by Cheryl Sabella
and Terry Jan Reedy in multiple issues.)

The font sample now includes a selection of non-Latin characters so that
users can better see the effect of selecting a particular font.
(Contributed by Terry Jan Reedy in bpo-13802(3).)  The sample can be
edited to include other characters.  (Contributed by Serhiy Storchaka in
bpo-31860(4).)

The IDLE features formerly implemented as extensions have been
reimplemented as normal features.  Their settings have been moved from
the Extensions tab to other dialog tabs.  (Contributed by Charles
Wohlganger and Terry Jan Reedy in bpo-27099(5).)

Editor code context option revised.  Box displays all context lines up
to maxlines.  Clicking on a context line jumps the editor to that line.
Context colors for custom themes is added to Highlights tab of Settings
dialog.  (Contributed by Cheryl Sabella and Terry Jan Reedy in
bpo-33642(6), bpo-33768(7), and bpo-33679(8).)

On Windows, a new API call tells Windows that tk scales for DPI. On
Windows 8.1+ or 10, with DPI compatibility properties of the Python
binary unchanged, and a monitor resolution greater than 96 DPI, this
should make text and lines sharper.  It should otherwise have no effect.
(Contributed by Terry Jan Reedy in bpo-33656(9).)

New in 3.7.1:

Output over N lines (50 by default) is squeezed down to a button.  N can
be changed in the PyShell section of the General page of the Settings
dialog.  Fewer, but possibly extra long, lines can be squeezed by right
clicking on the output.  Squeezed output can be expanded in place by
double-clicking the button or into the clipboard or a separate window by
right-clicking the button.  (Contributed by Tal Einat in
bpo-1529353(10).)

The changes above have been backported to 3.6 maintenance releases.

NEW in 3.7.4:

Add «Run Customized» to the Run menu to run a module with customized
settings.  Any command line arguments entered are added to sys.argv.
They re-appear in the box for the next customized run.  One can also
suppress the normal Shell main module restart.  (Contributed by Cheryl
Sabella, Terry Jan Reedy, and others in bpo-5680(11) and bpo-37627(12).)

New in 3.7.5:

Add optional line numbers for IDLE editor windows.  Windows open without
line numbers unless set otherwise in the General tab of the
configuration dialog.  Line numbers for an existing window are shown and
hidden in the Options menu.  (Contributed by Tal Einat and Saimadhav
Heblikar in bpo-17535(13).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15786

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1612262

   (3) https://bugs.python.org/issue?@action=redirect&bpo=13802

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31860

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27099

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33642

   (7) https://bugs.python.org/issue?@action=redirect&bpo=33768

   (8) https://bugs.python.org/issue?@action=redirect&bpo=33679

   (9) https://bugs.python.org/issue?@action=redirect&bpo=33656

   (10) https://bugs.python.org/issue?@action=redirect&bpo=1529353

   (11) https://bugs.python.org/issue?@action=redirect&bpo=5680

   (12) https://bugs.python.org/issue?@action=redirect&bpo=37627

   (13) https://bugs.python.org/issue?@action=redirect&bpo=17535


File: python.info,  Node: importlib<4>,  Next: io<6>,  Prev: idlelib and IDLE,  Up: Improved Modules<6>

1.8.5.23 importlib
..................

The ‘importlib.abc.ResourceReader’ ABC was introduced to support the
loading of resources from packages.  See also *note importlib.resources:
cbb.  (Contributed by Barry Warsaw, Brett Cannon in bpo-32248(1).)

*note importlib.reload(): 73e. now raises *note ModuleNotFoundError:
d3f. if the module lacks a spec.  (Contributed by Garvit Khatri in
bpo-29851(2).)

*note importlib.util.find_spec(): 5af. now raises *note
ModuleNotFoundError: d3f. instead of *note AttributeError: 5f0. if the
specified parent module is not a package (i.e.  lacks a ‘__path__’
attribute).  (Contributed by Milan Oberkirch in bpo-30436(3).)

The new *note importlib.util.source_hash(): d40. can be used to compute
the hash of the passed source.  A *note hash-based .pyc file: cc4.
embeds the value returned by this function.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32248

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29851

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30436


File: python.info,  Node: io<6>,  Next: ipaddress<3>,  Prev: importlib<4>,  Up: Improved Modules<6>

1.8.5.24 io
...........

The new *note TextIOWrapper.reconfigure(): d42. method can be used to
reconfigure the text stream with the new settings.  (Contributed by
Antoine Pitrou in bpo-30526(1) and INADA Naoki in bpo-15216(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30526

   (2) https://bugs.python.org/issue?@action=redirect&bpo=15216


File: python.info,  Node: ipaddress<3>,  Next: itertools<6>,  Prev: io<6>,  Up: Improved Modules<6>

1.8.5.25 ipaddress
..................

The new ‘subnet_of()’ and ‘supernet_of()’ methods of *note
ipaddress.IPv6Network: 510. and *note ipaddress.IPv4Network: 50f. can be
used for network containment tests.  (Contributed by Michel Albert and
Cheryl Sabella in bpo-20825(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20825


File: python.info,  Node: itertools<6>,  Next: locale<4>,  Prev: ipaddress<3>,  Up: Improved Modules<6>

1.8.5.26 itertools
..................

*note itertools.islice(): d45. now accepts *note integer-like objects:
19e. as start, stop, and slice arguments.  (Contributed by Will Roberts
in bpo-30537(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30537


File: python.info,  Node: locale<4>,  Next: logging<3>,  Prev: itertools<6>,  Up: Improved Modules<6>

1.8.5.27 locale
...............

The new 'monetary' argument to *note locale.format_string(): 743. can be
used to make the conversion use monetary thousands separators and
grouping strings.  (Contributed by Garvit in bpo-10379(1).)

The *note locale.getpreferredencoding(): 75d. function now always
returns ‘'UTF-8'’ on Android or when in the *note forced UTF-8 mode:
cc3.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10379


File: python.info,  Node: logging<3>,  Next: math<6>,  Prev: locale<4>,  Up: Improved Modules<6>

1.8.5.28 logging
................

*note Logger: d48. instances can now be pickled.  (Contributed by Vinay
Sajip in bpo-30520(1).)

The new *note StreamHandler.setStream(): d49. method can be used to
replace the logger stream after handler creation.  (Contributed by Vinay
Sajip in bpo-30522(2).)

It is now possible to specify keyword arguments to handler constructors
in configuration passed to *note logging.config.fileConfig(): d4a.
(Contributed by Preston Landers in bpo-31080(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30520

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30522

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31080


File: python.info,  Node: math<6>,  Next: mimetypes<3>,  Prev: logging<3>,  Up: Improved Modules<6>

1.8.5.29 math
.............

The new *note math.remainder(): d4c. function implements the IEEE
754-style remainder operation.  (Contributed by Mark Dickinson in
bpo-29962(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29962


File: python.info,  Node: mimetypes<3>,  Next: msilib,  Prev: math<6>,  Up: Improved Modules<6>

1.8.5.30 mimetypes
..................

The MIME type of .bmp has been changed from ‘'image/x-ms-bmp'’ to
‘'image/bmp'’.  (Contributed by Nitish Chandra in bpo-22589(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22589


File: python.info,  Node: msilib,  Next: multiprocessing<5>,  Prev: mimetypes<3>,  Up: Improved Modules<6>

1.8.5.31 msilib
...............

The new ‘Database.Close()’ method can be used to close the MSI database.
(Contributed by Berker Peksag in bpo-20486(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20486


File: python.info,  Node: multiprocessing<5>,  Next: os<8>,  Prev: msilib,  Up: Improved Modules<6>

1.8.5.32 multiprocessing
........................

The new *note Process.close(): d50. method explicitly closes the process
object and releases all resources associated with it.  *note ValueError:
2ec. is raised if the underlying process is still running.  (Contributed
by Antoine Pitrou in bpo-30596(1).)

The new *note Process.kill(): d51. method can be used to terminate the
process using the *note SIGKILL: d52. signal on Unix.  (Contributed by
Vitor Pereira in bpo-30794(2).)

Non-daemonic threads created by *note Process: 252. are now joined on
process exit.  (Contributed by Antoine Pitrou in bpo-18966(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30596

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30794

   (3) https://bugs.python.org/issue?@action=redirect&bpo=18966


File: python.info,  Node: os<8>,  Next: pathlib<11>,  Prev: multiprocessing<5>,  Up: Improved Modules<6>

1.8.5.33 os
...........

*note os.fwalk(): d54. now accepts the 'path' argument as *note bytes:
192.  (Contributed by Serhiy Storchaka in bpo-28682(1).)

*note os.scandir(): c56. gained support for *note file descriptors: d55.
(Contributed by Serhiy Storchaka in bpo-25996(2).)

The new *note register_at_fork(): 355. function allows registering
Python callbacks to be executed at process fork.  (Contributed by
Antoine Pitrou in bpo-16500(3).)

Added *note os.preadv(): d56. (combine the functionality of *note
os.readv(): d57. and *note os.pread(): d58.) and *note os.pwritev():
d59. functions (combine the functionality of *note os.writev(): d5a. and
*note os.pwrite(): d5b.).  (Contributed by Pablo Galindo in
bpo-31368(4).)

The mode argument of *note os.makedirs(): 52d. no longer affects the
file permission bits of newly created intermediate-level directories.
(Contributed by Serhiy Storchaka in bpo-19930(5).)

*note os.dup2(): d5c. now returns the new file descriptor.  Previously,
‘None’ was always returned.  (Contributed by Benjamin Peterson in
bpo-32441(6).)

The structure returned by *note os.stat(): 26d. now contains the *note
st_fstype: d5d. attribute on Solaris and its derivatives.  (Contributed
by Jesús Cea Avión in bpo-32659(7).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28682

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25996

   (3) https://bugs.python.org/issue?@action=redirect&bpo=16500

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31368

   (5) https://bugs.python.org/issue?@action=redirect&bpo=19930

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32441

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32659


File: python.info,  Node: pathlib<11>,  Next: pdb<6>,  Prev: os<8>,  Up: Improved Modules<6>

1.8.5.34 pathlib
................

The new *note Path.is_mount(): c0e. method is now available on POSIX
systems and can be used to determine whether a path is a mount point.
(Contributed by Cooper Ry Lees in bpo-30897(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30897


File: python.info,  Node: pdb<6>,  Next: py_compile<3>,  Prev: pathlib<11>,  Up: Improved Modules<6>

1.8.5.35 pdb
............

*note pdb.set_trace(): 272. now takes an optional 'header' keyword-only
argument.  If given, it is printed to the console just before debugging
begins.  (Contributed by Barry Warsaw in bpo-31389(1).)

*note pdb: aa. command line now accepts ‘-m module_name’ as an
alternative to script file.  (Contributed by Mario Corchero in
bpo-32206(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31389

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32206


File: python.info,  Node: py_compile<3>,  Next: pydoc<3>,  Prev: pdb<6>,  Up: Improved Modules<6>

1.8.5.36 py_compile
...................

*note py_compile.compile(): c1c. – and by extension, *note compileall:
21. – now respects the ‘SOURCE_DATE_EPOCH’ environment variable by
unconditionally creating ‘.pyc’ files for hash-based validation.  This
allows for guaranteeing reproducible builds(1) of ‘.pyc’ files when they
are created eagerly.  (Contributed by Bernhard M. Wiedemann in
bpo-29708(2).)

   ---------- Footnotes ----------

   (1) https://reproducible-builds.org/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29708


File: python.info,  Node: pydoc<3>,  Next: queue<2>,  Prev: py_compile<3>,  Up: Improved Modules<6>

1.8.5.37 pydoc
..............

The pydoc server can now bind to an arbitrary hostname specified by the
new ‘-n’ command-line argument.  (Contributed by Feanil Patel in
bpo-31128(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31128


File: python.info,  Node: queue<2>,  Next: re<5>,  Prev: pydoc<3>,  Up: Improved Modules<6>

1.8.5.38 queue
..............

The new *note SimpleQueue: d63. class is an unbounded FIFO queue.
(Contributed by Antoine Pitrou in bpo-14976(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14976


File: python.info,  Node: re<5>,  Next: signal<2>,  Prev: queue<2>,  Up: Improved Modules<6>

1.8.5.39 re
...........

The flags *note re.ASCII: 83f, *note re.LOCALE: d65. and *note
re.UNICODE: d66. can be set within the scope of a group.  (Contributed
by Serhiy Storchaka in bpo-31690(1).)

*note re.split(): 5a2. now supports splitting on a pattern like ‘r'\b'’,
‘'^$'’ or ‘(?=-)’ that matches an empty string.  (Contributed by Serhiy
Storchaka in bpo-25054(2).)

Regular expressions compiled with the *note re.LOCALE: d65. flag no
longer depend on the locale at compile time.  Locale settings are
applied only when the compiled regular expression is used.  (Contributed
by Serhiy Storchaka in bpo-30215(3).)

*note FutureWarning: 659. is now emitted if a regular expression
contains character set constructs that will change semantically in the
future, such as nested sets and set operations.  (Contributed by Serhiy
Storchaka in bpo-30349(4).)

Compiled regular expression and match objects can now be copied using
*note copy.copy(): 758. and *note copy.deepcopy(): d67.  (Contributed by
Serhiy Storchaka in bpo-10076(5).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31690

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25054

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30215

   (4) https://bugs.python.org/issue?@action=redirect&bpo=30349

   (5) https://bugs.python.org/issue?@action=redirect&bpo=10076


File: python.info,  Node: signal<2>,  Next: socket<6>,  Prev: re<5>,  Up: Improved Modules<6>

1.8.5.40 signal
...............

The new 'warn_on_full_buffer' argument to the *note
signal.set_wakeup_fd(): d69. function makes it possible to specify
whether Python prints a warning on stderr when the wakeup buffer
overflows.  (Contributed by Nathaniel J. Smith in bpo-30050(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30050


File: python.info,  Node: socket<6>,  Next: socketserver,  Prev: signal<2>,  Up: Improved Modules<6>

1.8.5.41 socket
...............

The new *note socket.getblocking(): d6b. method returns ‘True’ if the
socket is in blocking mode and ‘False’ otherwise.  (Contributed by Yury
Selivanov in bpo-32373(1).)

The new *note socket.close(): d6c. function closes the passed socket
file descriptor.  This function should be used instead of *note
os.close(): d6d. for better compatibility across platforms.
(Contributed by Christian Heimes in bpo-32454(2).)

The *note socket: d1. module now exposes the *note
socket.TCP_CONGESTION: d6e. (Linux 2.6.13), *note
socket.TCP_USER_TIMEOUT: d6e. (Linux 2.6.37), and *note
socket.TCP_NOTSENT_LOWAT: d6e. (Linux 3.12) constants.  (Contributed by
Omar Sandoval in bpo-26273(3) and Nathaniel J. Smith in bpo-29728(4).)

Support for *note socket.AF_VSOCK: d6f. sockets has been added to allow
communication between virtual machines and their hosts.  (Contributed by
Cathy Avery in bpo-27584(5).)

Sockets now auto-detect family, type and protocol from file descriptor
by default.  (Contributed by Christian Heimes in bpo-28134(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32373

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32454

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26273

   (4) https://bugs.python.org/issue?@action=redirect&bpo=29728

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27584

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28134


File: python.info,  Node: socketserver,  Next: sqlite3<7>,  Prev: socket<6>,  Up: Improved Modules<6>

1.8.5.42 socketserver
.....................

*note socketserver.ThreadingMixIn.server_close: d71. now waits until all
non-daemon threads complete.  *note
socketserver.ForkingMixIn.server_close: d71. now waits until all child
processes complete.

Add a new *note socketserver.ForkingMixIn.block_on_close: d72. class
attribute to *note socketserver.ForkingMixIn: d73. and *note
socketserver.ThreadingMixIn: d3c. classes.  Set the class attribute to
‘False’ to get the pre-3.7 behaviour.


File: python.info,  Node: sqlite3<7>,  Next: ssl<6>,  Prev: socketserver,  Up: Improved Modules<6>

1.8.5.43 sqlite3
................

*note sqlite3.Connection: 54e. now exposes the *note backup(): d75.
method when the underlying SQLite library is at version 3.6.11 or
higher.  (Contributed by Lele Gaifax in bpo-27645(1).)

The 'database' argument of *note sqlite3.connect(): 5a6. now accepts any
*note path-like object: 5a1, instead of just a string.  (Contributed by
Anders Lorentsen in bpo-31843(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27645

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31843


File: python.info,  Node: ssl<6>,  Next: string<2>,  Prev: sqlite3<7>,  Up: Improved Modules<6>

1.8.5.44 ssl
............

The *note ssl: d5. module now uses OpenSSL’s builtin API instead of
‘match_hostname()’ to check a host name or an IP address.  Values are
validated during TLS handshake.  Any certificate validation error
including failing the host name check now raises *note
SSLCertVerificationError: d77. and aborts the handshake with a proper
TLS Alert message.  The new exception contains additional information.
Host name validation can be customized with *note
SSLContext.hostname_checks_common_name: d78.  (Contributed by Christian
Heimes in bpo-31399(1).)

     Nota: The improved host name check requires a 'libssl'
     implementation compatible with OpenSSL 1.0.2 or 1.1.  Consequently,
     OpenSSL 0.9.8 and 1.0.1 are no longer supported (see *note Platform
     Support Removals: d79. for more details).  The ssl module is mostly
     compatible with LibreSSL 2.7.2 and newer.

The ‘ssl’ module no longer sends IP addresses in SNI TLS extension.
(Contributed by Christian Heimes in bpo-32185(2).)

‘match_hostname()’ no longer supports partial wildcards like
‘www*.example.org’.  (Contributed by Mandeep Singh in bpo-23033(3) and
Christian Heimes in bpo-31399(4).)

The default cipher suite selection of the ‘ssl’ module now uses a
blacklist approach rather than a hard-coded whitelist.  Python no longer
re-enables ciphers that have been blocked by OpenSSL security updates.
Default cipher suite selection can be configured at compile time.
(Contributed by Christian Heimes in bpo-31429(5).)

Validation of server certificates containing internationalized domain
names (IDNs) is now supported.  As part of this change, the *note
SSLSocket.server_hostname: d7a. attribute now stores the expected
hostname in A-label form (‘"xn--pythn-mua.org"’), rather than the
U-label form (‘"pythön.org"’).  (Contributed by Nathaniel J. Smith and
Christian Heimes in bpo-28414(6).)

The ‘ssl’ module has preliminary and experimental support for TLS 1.3
and OpenSSL 1.1.1.  At the time of Python 3.7.0 release, OpenSSL 1.1.1
is still under development and TLS 1.3 hasn’t been finalized yet.  The
TLS 1.3 handshake and protocol behaves slightly differently than TLS 1.2
and earlier, see *note TLS 1.3: d7b.  (Contributed by Christian Heimes
in bpo-32947(7), bpo-20995(8), bpo-29136(9), bpo-30622(10) and
bpo-33618(11))

*note SSLSocket: ae9. and *note SSLObject: d7c. no longer have a public
constructor.  Direct instantiation was never a documented and supported
feature.  Instances must be created with *note SSLContext: 357. methods
*note wrap_socket(): 749. and *note wrap_bio(): d7d.  (Contributed by
Christian Heimes in bpo-32951(12))

OpenSSL 1.1 APIs for setting the minimum and maximum TLS protocol
version are available as *note SSLContext.minimum_version: a72. and
*note SSLContext.maximum_version: a73.  Supported protocols are
indicated by several new flags, such as *note HAS_TLSv1_1: d7e.
(Contributed by Christian Heimes in bpo-32609(13).)

Added *note ssl.SSLContext.post_handshake_auth: c28. to enable and *note
ssl.SSLSocket.verify_client_post_handshake(): c29. to initiate TLS 1.3
post-handshake authentication.  (Contributed by Christian Heimes in
gh-78851(14).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31399

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32185

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23033

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31399

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31429

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28414

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32947

   (8) https://bugs.python.org/issue?@action=redirect&bpo=20995

   (9) https://bugs.python.org/issue?@action=redirect&bpo=29136

   (10) https://bugs.python.org/issue?@action=redirect&bpo=30622

   (11) https://bugs.python.org/issue?@action=redirect&bpo=33618

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32951

   (13) https://bugs.python.org/issue?@action=redirect&bpo=32609

   (14) https://github.com/python/cpython/issues/78851


File: python.info,  Node: string<2>,  Next: subprocess<2>,  Prev: ssl<6>,  Up: Improved Modules<6>

1.8.5.45 string
...............

*note string.Template: 898. now lets you to optionally modify the
regular expression pattern for braced placeholders and non-braced
placeholders separately.  (Contributed by Barry Warsaw in
bpo-1198569(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1198569


File: python.info,  Node: subprocess<2>,  Next: sys<8>,  Prev: string<2>,  Up: Improved Modules<6>

1.8.5.46 subprocess
...................

The *note subprocess.run(): d81. function accepts the new
'capture_output' keyword argument.  When true, stdout and stderr will be
captured.  This is equivalent to passing *note subprocess.PIPE: d82. as
'stdout' and 'stderr' arguments.  (Contributed by Bo Bayles in
bpo-32102(1).)

The ‘subprocess.run’ function and the *note subprocess.Popen: 4b8.
constructor now accept the 'text' keyword argument as an alias to
'universal_newlines'.  (Contributed by Andrew Clegg in bpo-31756(2).)

On Windows the default for 'close_fds' was changed from ‘False’ to
‘True’ when redirecting the standard handles.  It’s now possible to set
'close_fds' to true when redirecting the standard handles.  See *note
subprocess.Popen: 4b8.  This means that 'close_fds' now defaults to
‘True’ on all supported platforms.  (Contributed by Segev Finer in
bpo-19764(3).)

The subprocess module is now more graceful when handling *note
KeyboardInterrupt: bc7. during *note subprocess.call(): d83, *note
subprocess.run(): d81, or in a *note Popen: 4b8. context manager.  It
now waits a short amount of time for the child to exit, before
continuing the handling of the ‘KeyboardInterrupt’ exception.
(Contributed by Gregory P. Smith in bpo-25942(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32102

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31756

   (3) https://bugs.python.org/issue?@action=redirect&bpo=19764

   (4) https://bugs.python.org/issue?@action=redirect&bpo=25942


File: python.info,  Node: sys<8>,  Next: time<5>,  Prev: subprocess<2>,  Up: Improved Modules<6>

1.8.5.47 sys
............

The new *note sys.breakpointhook(): cd3. hook function is called by the
built-in *note breakpoint(): 271.  (Contributed by Barry Warsaw in
bpo-31353(1).)

On Android, the new *note sys.getandroidapilevel(): d85. returns the
build-time Android API version.  (Contributed by Victor Stinner in
bpo-28740(2).)

The new *note sys.get_coroutine_origin_tracking_depth(): d86. function
returns the current coroutine origin tracking depth, as set by the new
*note sys.set_coroutine_origin_tracking_depth(): d87.  *note asyncio: b.
has been converted to use this new API instead of the deprecated
‘sys.set_coroutine_wrapper()’.  (Contributed by Nathaniel J. Smith in
bpo-32591(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31353

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28740

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32591


File: python.info,  Node: time<5>,  Next: tkinter<6>,  Prev: sys<8>,  Up: Improved Modules<6>

1.8.5.48 time
.............

PEP 564(1) adds six new functions with nanosecond resolution to the
*note time: f4. module:

   * *note time.clock_gettime_ns(): cdd.

   * *note time.clock_settime_ns(): cde.

   * *note time.monotonic_ns(): cdf.

   * *note time.perf_counter_ns(): ce0.

   * *note time.process_time_ns(): ce1.

   * *note time.time_ns(): ce2.

New clock identifiers have been added:

   * *note time.CLOCK_BOOTTIME: d89. (Linux): Identical to *note
     time.CLOCK_MONOTONIC: 8a9, except it also includes any time that
     the system is suspended.

   * *note time.CLOCK_PROF: d8a. (FreeBSD, NetBSD and OpenBSD):
     High-resolution per-process CPU timer.

   * *note time.CLOCK_UPTIME: d8b. (FreeBSD, OpenBSD): Time whose
     absolute value is the time the system has been running and not
     suspended, providing accurate uptime measurement.

The new *note time.thread_time(): b32. and *note time.thread_time_ns():
d8c. functions can be used to get per-thread CPU time measurements.
(Contributed by Antoine Pitrou in bpo-32025(2).)

The new *note time.pthread_getcpuclockid(): d8d. function returns the
clock ID of the thread-specific CPU-time clock.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0564/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32025


File: python.info,  Node: tkinter<6>,  Next: tracemalloc<2>,  Prev: time<5>,  Up: Improved Modules<6>

1.8.5.49 tkinter
................

The new *note tkinter.ttk.Spinbox: d8f. class is now available.
(Contributed by Alan Moore in bpo-32585(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32585


File: python.info,  Node: tracemalloc<2>,  Next: types<5>,  Prev: tkinter<6>,  Up: Improved Modules<6>

1.8.5.50 tracemalloc
....................

*note tracemalloc.Traceback: d91. behaves more like regular tracebacks,
sorting the frames from oldest to most recent.  *note
Traceback.format(): d92. now accepts negative 'limit', truncating the
result to the ‘abs(limit)’ oldest frames.  To get the old behaviour, use
the new 'most_recent_first' argument to ‘Traceback.format()’.
(Contributed by Jesse Bakker in bpo-32121(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32121


File: python.info,  Node: types<5>,  Next: unicodedata<7>,  Prev: tracemalloc<2>,  Up: Improved Modules<6>

1.8.5.51 types
..............

The new *note WrapperDescriptorType: d94, *note MethodWrapperType: 85c,
*note MethodDescriptorType: d95, and *note ClassMethodDescriptorType:
d96. classes are now available.  (Contributed by Manuel Krebber and
Guido van Rossum in bpo-29377(1), and Serhiy Storchaka in bpo-32265(2).)

The new *note types.resolve_bases(): d97. function resolves MRO entries
dynamically as specified by PEP 560(3).  (Contributed by Ivan Levkivskyi
in bpo-32717(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29377

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32265

   (3) https://peps.python.org/pep-0560/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32717


File: python.info,  Node: unicodedata<7>,  Next: unittest<8>,  Prev: types<5>,  Up: Improved Modules<6>

1.8.5.52 unicodedata
....................

The internal *note unicodedata: 10b. database has been upgraded to use
Unicode 11(1).  (Contributed by Benjamin Peterson.)

   ---------- Footnotes ----------

   (1) https://www.unicode.org/versions/Unicode11.0.0/


File: python.info,  Node: unittest<8>,  Next: unittest mock,  Prev: unicodedata<7>,  Up: Improved Modules<6>

1.8.5.53 unittest
.................

The new ‘-k’ command-line option allows filtering tests by a name
substring or a Unix shell-like pattern.  For example, ‘python -m
unittest -k foo’ runs ‘foo_tests.SomeTest.test_something’,
‘bar_tests.SomeTest.test_foo’, but not
‘bar_tests.FooTest.test_something’.  (Contributed by Jonas Haag in
bpo-32071(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32071


File: python.info,  Node: unittest mock,  Next: urllib parse<5>,  Prev: unittest<8>,  Up: Improved Modules<6>

1.8.5.54 unittest.mock
......................

The *note sentinel: d9b. attributes now preserve their identity when
they are *note copied: 29. or *note pickled: ab.  (Contributed by Serhiy
Storchaka in bpo-20804(1).)

The new *note seal(): d9c. function allows sealing *note Mock: c41.
instances, which will disallow further creation of attribute mocks.  The
seal is applied recursively to all attributes that are themselves mocks.
(Contributed by Mario Corchero in bpo-30541(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20804

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30541


File: python.info,  Node: urllib parse<5>,  Next: uu,  Prev: unittest mock,  Up: Improved Modules<6>

1.8.5.55 urllib.parse
.....................

*note urllib.parse.quote(): d9e. has been updated from RFC 2396(1) to
RFC 3986(2), adding ‘~’ to the set of characters that are never quoted
by default.  (Contributed by Christian Theune and Ratnadeep Debnath in
bpo-16285(3).)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2396.html

   (2) https://datatracker.ietf.org/doc/html/rfc3986.html

   (3) https://bugs.python.org/issue?@action=redirect&bpo=16285


File: python.info,  Node: uu,  Next: uuid<4>,  Prev: urllib parse<5>,  Up: Improved Modules<6>

1.8.5.56 uu
...........

The ‘uu.encode()’ function now accepts an optional 'backtick' keyword
argument.  When it’s true, zeros are represented by ‘'`'’ instead of
spaces.  (Contributed by Xiang Zhang in bpo-30103(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30103


File: python.info,  Node: uuid<4>,  Next: warnings<3>,  Prev: uu,  Up: Improved Modules<6>

1.8.5.57 uuid
.............

The new *note UUID.is_safe: da1. attribute relays information from the
platform about whether generated UUIDs are generated with a
multiprocessing-safe method.  (Contributed by Barry Warsaw in
bpo-22807(1).)

*note uuid.getnode(): da2. now prefers universally administered MAC
addresses over locally administered MAC addresses.  This makes a better
guarantee for global uniqueness of UUIDs returned from *note
uuid.uuid1(): da3.  If only locally administered MAC addresses are
available, the first such one found is returned.  (Contributed by Barry
Warsaw in bpo-32107(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22807

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32107


File: python.info,  Node: warnings<3>,  Next: xml<5>,  Prev: uuid<4>,  Up: Improved Modules<6>

1.8.5.58 warnings
.................

The initialization of the default warnings filters has changed as
follows:

   * warnings enabled via command line options (including those for
     *note -b: 7fa. and the new CPython-specific *note -X: 16f. ‘dev’
     option) are always passed to the warnings machinery via the *note
     sys.warnoptions: 3f5. attribute.

   * warnings filters enabled via the command line or the environment
     now have the following order of precedence:

        * the ‘BytesWarning’ filter for *note -b: 7fa. (or ‘-bb’)

        * any filters specified with the *note -W: ac7. option

        * any filters specified with the *note PYTHONWARNINGS: da5.
          environment variable

        * any other CPython specific filters (e.g.  the ‘default’ filter
          added for the new ‘-X dev’ mode)

        * any implicit filters defined directly by the warnings
          machinery

   * in *note CPython debug builds: 50a, all warnings are now displayed
     by default (the implicit filter list is empty)

(Contributed by Nick Coghlan and Victor Stinner in bpo-20361(1),
bpo-32043(2), and bpo-32230(3).)

Deprecation warnings are once again shown by default in single-file
scripts and at the interactive prompt.  See *note PEP 565; Show
DeprecationWarning in __main__: cc6. for details.  (Contributed by Nick
Coghlan in bpo-31975(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20361

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32043

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32230

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31975


File: python.info,  Node: xml<5>,  Next: xml etree,  Prev: warnings<3>,  Up: Improved Modules<6>

1.8.5.59 xml
............

As mitigation against DTD and external entity retrieval, the *note
xml.dom.minidom: 128. and *note xml.sax: 12f. modules no longer process
external entities by default.  (Contributed by Christian Heimes in
gh-61441(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/61441


File: python.info,  Node: xml etree,  Next: xmlrpc server,  Prev: xml<5>,  Up: Improved Modules<6>

1.8.5.60 xml.etree
..................

*note ElementPath: da8. predicates in the ‘find()’ methods can now
compare text of the current node with ‘[. = "text"]’, not only text in
children.  Predicates also allow adding spaces for better readability.
(Contributed by Stefan Behnel in bpo-31648(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31648


File: python.info,  Node: xmlrpc server,  Next: zipapp,  Prev: xml etree,  Up: Improved Modules<6>

1.8.5.61 xmlrpc.server
......................

‘SimpleXMLRPCDispatcher.register_function()’ can now be used as a
decorator.  (Contributed by Xiang Zhang in bpo-7769(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=7769


File: python.info,  Node: zipapp,  Next: zipfile<3>,  Prev: xmlrpc server,  Up: Improved Modules<6>

1.8.5.62 zipapp
...............

Function *note create_archive(): dab. now accepts an optional 'filter'
argument to allow the user to select which files should be included in
the archive.  (Contributed by Irmen de Jong in bpo-31072(1).)

Function *note create_archive(): dab. now accepts an optional
'compressed' argument to generate a compressed archive.  A command line
option ‘--compress’ has also been added to support compression.
(Contributed by Zhiming Wang in bpo-31638(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31072

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31638


File: python.info,  Node: zipfile<3>,  Prev: zipapp,  Up: Improved Modules<6>

1.8.5.63 zipfile
................

*note ZipFile: 8d4. now accepts the new 'compresslevel' parameter to
control the compression level.  (Contributed by Bo Bayles in
bpo-21417(1).)

Subdirectories in archives created by ‘ZipFile’ are now stored in
alphabetical order.  (Contributed by Bernhard M. Wiedemann in
bpo-30693(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21417

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30693


File: python.info,  Node: C API Changes<5>,  Next: Build Changes<5>,  Prev: Improved Modules<6>,  Up: What’s New In Python 3 7

1.8.6 C API Changes
-------------------

A new API for thread-local storage has been implemented.  See *note PEP
539; New C API for Thread-Local Storage: cc7. for an overview and *note
Thread Specific Storage (TSS) API: cd7. for a complete reference.
(Contributed by Masayuki Yamamoto in bpo-25658(1).)

The new *note context variables: cb9. functionality exposes a number of
*note new C APIs: cf2.

The new *note PyImport_GetModule(): dae. function returns the previously
imported module with the given name.  (Contributed by Eric Snow in
bpo-28411(2).)

The new *note Py_RETURN_RICHCOMPARE: daf. macro eases writing rich
comparison functions.  (Contributed by Petr Victorin in bpo-23699(3).)

The new *note Py_UNREACHABLE: db0. macro can be used to mark unreachable
code paths.  (Contributed by Barry Warsaw in bpo-31338(4).)

The *note tracemalloc: 105. now exposes a C API through the new *note
PyTraceMalloc_Track(): db1. and *note PyTraceMalloc_Untrack(): db2.
functions.  (Contributed by Victor Stinner in bpo-30054(5).)

The new *note import__find__load__start: db3. and *note
import__find__load__done: db3. static markers can be used to trace
module imports.  (Contributed by Christian Heimes in bpo-31574(6).)

The fields ‘name’ and ‘doc’ of structures *note PyMemberDef: 772, *note
PyGetSetDef: db4, *note PyStructSequence_Field: db5, *note
PyStructSequence_Desc: db6, and ‘wrapperbase’ are now of type ‘const
char *’ rather of ‘char *’.  (Contributed by Serhiy Storchaka in
bpo-28761(7).)

The result of *note PyUnicode_AsUTF8AndSize(): a9b. and *note
PyUnicode_AsUTF8(): 424. is now of type ‘const char *’ rather of ‘char
*’.  (Contributed by Serhiy Storchaka in bpo-28769(8).)

The result of *note PyMapping_Keys(): db7, *note PyMapping_Values():
db8. and *note PyMapping_Items(): db9. is now always a list, rather than
a list or a tuple.  (Contributed by Oren Milman in bpo-28280(9).)

Added functions *note PySlice_Unpack(): 432. and *note
PySlice_AdjustIndices(): 433.  (Contributed by Serhiy Storchaka in
bpo-27867(10).)

*note PyOS_AfterFork(): 42f. is deprecated in favour of the new
functions *note PyOS_BeforeFork(): dba, *note PyOS_AfterFork_Parent():
dbb. and *note PyOS_AfterFork_Child(): 430.  (Contributed by Antoine
Pitrou in bpo-16500(11).)

The ‘PyExc_RecursionErrorInst’ singleton that was part of the public API
has been removed as its members being never cleared may cause a segfault
during finalization of the interpreter.  Contributed by Xavier de Gaye
in bpo-22898(12) and bpo-30697(13).

Added C API support for timezones with timezone constructors *note
PyTimeZone_FromOffset(): dbc. and *note PyTimeZone_FromOffsetAndName():
dbd, and access to the UTC singleton with *note PyDateTime_TimeZone_UTC:
dbe.  Contributed by Paul Ganssle in bpo-10381(14).

The type of results of ‘PyThread_start_new_thread()’ and
‘PyThread_get_thread_ident()’, and the 'id' parameter of *note
PyThreadState_SetAsyncExc(): dbf. changed from long to unsigned long.
(Contributed by Serhiy Storchaka in bpo-6532(15).)

*note PyUnicode_AsWideCharString(): abb. now raises a *note ValueError:
2ec. if the second argument is ‘NULL’ and the wchar_t* string contains
null characters.  (Contributed by Serhiy Storchaka in bpo-30708(16).)

Changes to the startup sequence and the management of dynamic memory
allocators mean that the long documented requirement to call *note
Py_Initialize(): 460. before calling most C API functions is now relied
on more heavily, and failing to abide by it may lead to segfaults in
embedding applications.  See the *note Porting to Python 3.7: cca.
section in this document and the *note Before Python Initialization:
dc0. section in the C API documentation for more details.

The new *note PyInterpreterState_GetID(): dc1. returns the unique ID for
a given interpreter.  (Contributed by Eric Snow in bpo-29102(17).)

*note Py_DecodeLocale(): dc2, *note Py_EncodeLocale(): dc3. now use the
UTF-8 encoding when the *note UTF-8 mode: cc3. is enabled.  (Contributed
by Victor Stinner in bpo-29240(18).)

*note PyUnicode_DecodeLocaleAndSize(): dc4. and *note
PyUnicode_EncodeLocale(): dc5. now use the current locale encoding for
‘surrogateescape’ error handler.  (Contributed by Victor Stinner in
bpo-29240(19).)

The 'start' and 'end' parameters of *note PyUnicode_FindChar(): ab8. are
now adjusted to behave like string slices.  (Contributed by Xiang Zhang
in bpo-28822(20).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25658

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28411

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23699

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31338

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30054

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31574

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28761

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28769

   (9) https://bugs.python.org/issue?@action=redirect&bpo=28280

   (10) https://bugs.python.org/issue?@action=redirect&bpo=27867

   (11) https://bugs.python.org/issue?@action=redirect&bpo=16500

   (12) https://bugs.python.org/issue?@action=redirect&bpo=22898

   (13) https://bugs.python.org/issue?@action=redirect&bpo=30697

   (14) https://bugs.python.org/issue?@action=redirect&bpo=10381

   (15) https://bugs.python.org/issue?@action=redirect&bpo=6532

   (16) https://bugs.python.org/issue?@action=redirect&bpo=30708

   (17) https://bugs.python.org/issue?@action=redirect&bpo=29102

   (18) https://bugs.python.org/issue?@action=redirect&bpo=29240

   (19) https://bugs.python.org/issue?@action=redirect&bpo=29240

   (20) https://bugs.python.org/issue?@action=redirect&bpo=28822


File: python.info,  Node: Build Changes<5>,  Next: Optimizations<7>,  Prev: C API Changes<5>,  Up: What’s New In Python 3 7

1.8.7 Build Changes
-------------------

Support for building ‘--without-threads’ has been removed.  The *note
threading: f3. module is now always available.  (Contributed by Antoine
Pitrou in bpo-31370(1).).

A full copy of libffi is no longer bundled for use when building the
*note _ctypes: 2e. module on non-OSX UNIX platforms.  An installed copy
of libffi is now required when building ‘_ctypes’ on such platforms.
(Contributed by Zachary Ware in bpo-27979(2).)

The Windows build process no longer depends on Subversion to pull in
external sources, a Python script is used to download zipfiles from
GitHub instead.  If Python 3.6 is not found on the system (via ‘py
-3.6’), NuGet is used to download a copy of 32-bit Python for this
purpose.  (Contributed by Zachary Ware in bpo-30450(3).)

The *note ssl: d5. module requires OpenSSL 1.0.2 or 1.1 compatible
libssl.  OpenSSL 1.0.1 has reached end of lifetime on 2016-12-31 and is
no longer supported.  LibreSSL is temporarily not supported as well.
LibreSSL releases up to version 2.6.4 are missing required OpenSSL 1.0.2
APIs.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31370

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27979

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30450


File: python.info,  Node: Optimizations<7>,  Next: Other CPython Implementation Changes<2>,  Prev: Build Changes<5>,  Up: What’s New In Python 3 7

1.8.8 Optimizations
-------------------

The overhead of calling many methods of various standard library classes
implemented in C has been significantly reduced by porting more code to
use the ‘METH_FASTCALL’ convention.  (Contributed by Victor Stinner in
bpo-29300(1), bpo-29507(2), bpo-29452(3), and bpo-29286(4).)

Various optimizations have reduced Python startup time by 10% on Linux
and up to 30% on macOS. (Contributed by Victor Stinner, INADA Naoki in
bpo-29585(5), and Ivan Levkivskyi in bpo-31333(6).)

Method calls are now up to 20% faster due to the bytecode changes which
avoid creating bound method instances.  (Contributed by Yury Selivanov
and INADA Naoki in bpo-26110(7).)  The *note asyncio: b. module received
a number of notable optimizations for commonly used functions:

   * The *note asyncio.get_event_loop(): 2f2. function has been
     reimplemented in C to make it up to 15 times faster.  (Contributed
     by Yury Selivanov in bpo-32296(8).)

   * *note asyncio.Future: dc8. callback management has been optimized.
     (Contributed by Yury Selivanov in bpo-32348(9).)

   * *note asyncio.gather(): 814. is now up to 15% faster.  (Contributed
     by Yury Selivanov in bpo-32355(10).)

   * *note asyncio.sleep(): c66. is now up to 2 times faster when the
     'delay' argument is zero or negative.  (Contributed by Andrew
     Svetlov in bpo-32351(11).)

   * The performance overhead of asyncio debug mode has been reduced.
     (Contributed by Antoine Pitrou in bpo-31970(12).)

As a result of *note PEP 560 work: cbe, the import time of *note typing:
10a. has been reduced by a factor of 7, and many typing operations are
now faster.  (Contributed by Ivan Levkivskyi in bpo-32226(13).)

*note sorted(): dc9. and *note list.sort(): dca. have been optimized for
common cases to be up to 40-75% faster.  (Contributed by Elliot
Gorokhovsky in bpo-28685(14).)

*note dict.copy(): dcb. is now up to 5.5 times faster.  (Contributed by
Yury Selivanov in bpo-31179(15).)

*note hasattr(): 6fa. and *note getattr(): dcc. are now about 4 times
faster when 'name' is not found and 'obj' does not override *note
object.__getattr__(): 6fb. or *note object.__getattribute__(): dcd.
(Contributed by INADA Naoki in bpo-32544(16).)

Searching for certain Unicode characters (like Ukrainian capital «Є») in
a string was up to 25 times slower than searching for other characters.
It is now only 3 times slower in the worst case.  (Contributed by Serhiy
Storchaka in bpo-24821(17).)

The *note collections.namedtuple(): 4e1. factory has been reimplemented
to make the creation of named tuples 4 to 6 times faster.  (Contributed
by Jelle Zijlstra with further improvements by INADA Naoki, Serhiy
Storchaka, and Raymond Hettinger in bpo-28638(18).)

*note datetime.date.fromordinal(): dce. and *note
datetime.date.fromtimestamp(): dcf. are now up to 30% faster in the
common case.  (Contributed by Paul Ganssle in bpo-32403(19).)

The *note os.fwalk(): d54. function is now up to 2 times faster thanks
to the use of *note os.scandir(): c56.  (Contributed by Serhiy Storchaka
in bpo-25996(20).)

The speed of the *note shutil.rmtree(): 356. function has been improved
by 20–40% thanks to the use of the *note os.scandir(): c56. function.
(Contributed by Serhiy Storchaka in bpo-28564(21).)

Optimized case-insensitive matching and searching of *note regular
expressions: be.  Searching some patterns can now be up to 20 times
faster.  (Contributed by Serhiy Storchaka in bpo-30285(22).)

*note re.compile(): dd0. now converts ‘flags’ parameter to int object if
it is ‘RegexFlag’.  It is now as fast as Python 3.5, and faster than
Python 3.6 by about 10% depending on the pattern.  (Contributed by INADA
Naoki in bpo-31671(23).)

The *note modify(): dd1. methods of classes *note
selectors.EpollSelector: dd2, *note selectors.PollSelector: dd3. and
*note selectors.DevpollSelector: dd4. may be around 10% faster under
heavy loads.  (Contributed by Giampaolo Rodola” in bpo-30014(24))

Constant folding has been moved from the peephole optimizer to the new
AST optimizer, which is able perform optimizations more consistently.
(Contributed by Eugene Toder and INADA Naoki in bpo-29469(25) and
bpo-11549(26).)

Most functions and methods in *note abc: 4. have been rewritten in C.
This makes creation of abstract base classes, and calling *note
isinstance(): 2ad. and *note issubclass(): 9c6. on them 1.5x faster.
This also reduces Python start-up time by up to 10%.  (Contributed by
Ivan Levkivskyi and INADA Naoki in bpo-31333(27))

Significant speed improvements to alternate constructors for *note
datetime.date: 1fa. and *note datetime.datetime: 4e3. by using fast-path
constructors when not constructing subclasses.  (Contributed by Paul
Ganssle in bpo-32403(28))

The speed of comparison of *note array.array: 4bf. instances has been
improved considerably in certain cases.  It is now from 10x to 70x
faster when comparing arrays holding values of the same integer type.
(Contributed by Adrian Wielgosik in bpo-24700(29).)

The *note math.erf(): dd5. and *note math.erfc(): dd6. functions now use
the (faster) C library implementation on most platforms.  (Contributed
by Serhiy Storchaka in bpo-26121(30).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29300

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29507

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29452

   (4) https://bugs.python.org/issue?@action=redirect&bpo=29286

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29585

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31333

   (7) https://bugs.python.org/issue?@action=redirect&bpo=26110

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32296

   (9) https://bugs.python.org/issue?@action=redirect&bpo=32348

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32355

   (11) https://bugs.python.org/issue?@action=redirect&bpo=32351

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31970

   (13) https://bugs.python.org/issue?@action=redirect&bpo=32226

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28685

   (15) https://bugs.python.org/issue?@action=redirect&bpo=31179

   (16) https://bugs.python.org/issue?@action=redirect&bpo=32544

   (17) https://bugs.python.org/issue?@action=redirect&bpo=24821

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28638

   (19) https://bugs.python.org/issue?@action=redirect&bpo=32403

   (20) https://bugs.python.org/issue?@action=redirect&bpo=25996

   (21) https://bugs.python.org/issue?@action=redirect&bpo=28564

   (22) https://bugs.python.org/issue?@action=redirect&bpo=30285

   (23) https://bugs.python.org/issue?@action=redirect&bpo=31671

   (24) https://bugs.python.org/issue?@action=redirect&bpo=30014

   (25) https://bugs.python.org/issue?@action=redirect&bpo=29469

   (26) https://bugs.python.org/issue?@action=redirect&bpo=11549

   (27) https://bugs.python.org/issue?@action=redirect&bpo=31333

   (28) https://bugs.python.org/issue?@action=redirect&bpo=32403

   (29) https://bugs.python.org/issue?@action=redirect&bpo=24700

   (30) https://bugs.python.org/issue?@action=redirect&bpo=26121


File: python.info,  Node: Other CPython Implementation Changes<2>,  Next: Deprecated Python Behavior,  Prev: Optimizations<7>,  Up: What’s New In Python 3 7

1.8.9 Other CPython Implementation Changes
------------------------------------------

   * Trace hooks may now opt out of receiving the ‘line’ and opt into
     receiving the ‘opcode’ events from the interpreter by setting the
     corresponding new *note f_trace_lines: dd8. and *note
     f_trace_opcodes: dd9. attributes on the frame being traced.
     (Contributed by Nick Coghlan in bpo-31344(1).)

   * Fixed some consistency problems with namespace package module
     attributes.  Namespace module objects now have an ‘__file__’ that
     is set to ‘None’ (previously unset), and their ‘__spec__.origin’ is
     also set to ‘None’ (previously the string ‘"namespace"’).  See
     bpo-32305(2).  Also, the namespace module object’s
     ‘__spec__.loader’ is set to the same value as ‘__loader__’
     (previously, the former was set to ‘None’).  See bpo-32303(3).

   * The *note locals(): 46f. dictionary now displays in the lexical
     order that variables were defined.  Previously, the order was
     undefined.  (Contributed by Raymond Hettinger in bpo-32690(4).)

   * The ‘distutils’ ‘upload’ command no longer tries to change CR
     end-of-line characters to CRLF. This fixes a corruption issue with
     sdists that ended with a byte equivalent to CR. (Contributed by Bo
     Bayles in bpo-32304(5).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31344

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32305

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32303

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32690

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32304


File: python.info,  Node: Deprecated Python Behavior,  Next: Deprecated Python modules functions and methods,  Prev: Other CPython Implementation Changes<2>,  Up: What’s New In Python 3 7

1.8.10 Deprecated Python Behavior
---------------------------------

Yield expressions (both ‘yield’ and ‘yield from’ clauses) are now
deprecated in comprehensions and generator expressions (aside from the
iterable expression in the leftmost ‘for’ clause).  This ensures that
comprehensions always immediately return a container of the appropriate
type (rather than potentially returning a *note generator iterator: ddb.
object), while generator expressions won’t attempt to interleave their
implicit output with the output from any explicit yield expressions.  In
Python 3.7, such expressions emit *note DeprecationWarning: 1a3. when
compiled, in Python 3.8 this will be a *note SyntaxError: 18e.
(Contributed by Serhiy Storchaka in bpo-10544(1).)

Returning a subclass of *note complex: 197. from *note
object.__complex__(): 7fe. is deprecated and will be an error in future
Python versions.  This makes ‘__complex__()’ consistent with *note
object.__int__(): 19d. and *note object.__float__(): bc3.  (Contributed
by Serhiy Storchaka in bpo-28894(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10544

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28894


File: python.info,  Node: Deprecated Python modules functions and methods,  Next: Deprecated functions and types of the C API,  Prev: Deprecated Python Behavior,  Up: What’s New In Python 3 7

1.8.11 Deprecated Python modules, functions and methods
-------------------------------------------------------

* Menu:

* aifc::
* asyncio: asyncio<11>.
* collections: collections<3>.
* dbm: dbm<3>.
* enum: enum<6>.
* gettext: gettext<2>.
* importlib: importlib<5>.
* locale: locale<5>.
* macpath::
* threading: threading<6>.
* socket: socket<7>.
* ssl: ssl<7>.
* sunau::
* sys: sys<9>.
* wave::


File: python.info,  Node: aifc,  Next: asyncio<11>,  Up: Deprecated Python modules functions and methods

1.8.11.1 aifc
.............

‘aifc.openfp()’ has been deprecated and will be removed in Python 3.9.
Use ‘aifc.open()’ instead.  (Contributed by Brian Curtin in
bpo-31985(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31985


File: python.info,  Node: asyncio<11>,  Next: collections<3>,  Prev: aifc,  Up: Deprecated Python modules functions and methods

1.8.11.2 asyncio
................

Support for directly ‘await’-ing instances of *note asyncio.Lock: c68.
and other asyncio synchronization primitives has been deprecated.  An
asynchronous context manager must be used in order to acquire and
release the synchronization resource.  (Contributed by Andrew Svetlov in
bpo-32253(1).)

The ‘asyncio.Task.current_task()’ and ‘asyncio.Task.all_tasks()’ methods
have been deprecated.  (Contributed by Andrew Svetlov in bpo-32250(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32253

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32250


File: python.info,  Node: collections<3>,  Next: dbm<3>,  Prev: asyncio<11>,  Up: Deprecated Python modules functions and methods

1.8.11.3 collections
....................

In Python 3.8, the abstract base classes in *note collections.abc: 1f.
will no longer be exposed in the regular *note collections: 1e. module.
This will help create a clearer distinction between the concrete classes
and the abstract base classes.  (Contributed by Serhiy Storchaka in
bpo-25988(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25988


File: python.info,  Node: dbm<3>,  Next: enum<6>,  Prev: collections<3>,  Up: Deprecated Python modules functions and methods

1.8.11.4 dbm
............

*note dbm.dumb: 36. now supports reading read-only files and no longer
writes the index file when it is not changed.  A deprecation warning is
now emitted if the index file is missing and recreated in the ‘'r'’ and
‘'w'’ modes (this will be an error in future Python releases).
(Contributed by Serhiy Storchaka in bpo-28847(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28847


File: python.info,  Node: enum<6>,  Next: gettext<2>,  Prev: dbm<3>,  Up: Deprecated Python modules functions and methods

1.8.11.5 enum
.............

In Python 3.8, attempting to check for non-Enum objects in *note Enum:
843. classes will raise a *note TypeError: 198. (e.g.  ‘1 in Color’);
similarly, attempting to check for non-Flag objects in a *note Flag:
836. member will raise *note TypeError: 198. (e.g.  ‘1 in Perm.RW’);
currently, both operations return *note False: d2d. instead.
(Contributed by Ethan Furman in bpo-33217(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33217


File: python.info,  Node: gettext<2>,  Next: importlib<5>,  Prev: enum<6>,  Up: Deprecated Python modules functions and methods

1.8.11.6 gettext
................

Using non-integer value for selecting a plural form in *note gettext:
67. is now deprecated.  It never correctly worked.  (Contributed by
Serhiy Storchaka in bpo-28692(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28692


File: python.info,  Node: importlib<5>,  Next: locale<5>,  Prev: gettext<2>,  Up: Deprecated Python modules functions and methods

1.8.11.7 importlib
..................

Methods ‘MetaPathFinder.find_module()’ (replaced by *note
MetaPathFinder.find_spec(): a6a.) and ‘PathEntryFinder.find_loader()’
(replaced by *note PathEntryFinder.find_spec(): a6e.) both deprecated in
Python 3.4 now emit *note DeprecationWarning: 1a3.  (Contributed by
Matthias Bussonnier in bpo-29576(1).)

The *note importlib.abc.ResourceLoader: de4. ABC has been deprecated in
favour of ‘importlib.abc.ResourceReader’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29576


File: python.info,  Node: locale<5>,  Next: macpath,  Prev: importlib<5>,  Up: Deprecated Python modules functions and methods

1.8.11.8 locale
...............

‘locale.format()’ has been deprecated, use *note locale.format_string():
743. instead.  (Contributed by Garvit in bpo-10379(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10379


File: python.info,  Node: macpath,  Next: threading<6>,  Prev: locale<5>,  Up: Deprecated Python modules functions and methods

1.8.11.9 macpath
................

The ‘macpath’ is now deprecated and will be removed in Python 3.8.
(Contributed by Chi Hsuan Yen in bpo-9850(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9850


File: python.info,  Node: threading<6>,  Next: socket<7>,  Prev: macpath,  Up: Deprecated Python modules functions and methods

1.8.11.10 threading
...................

‘dummy_threading’ and ‘_dummy_thread’ have been deprecated.  It is no
longer possible to build Python with threading disabled.  Use *note
threading: f3. instead.  (Contributed by Antoine Pitrou in
bpo-31370(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31370


File: python.info,  Node: socket<7>,  Next: ssl<7>,  Prev: threading<6>,  Up: Deprecated Python modules functions and methods

1.8.11.11 socket
................

The silent argument value truncation in *note socket.htons(): a81. and
*note socket.ntohs(): a82. has been deprecated.  In future versions of
Python, if the passed argument is larger than 16 bits, an exception will
be raised.  (Contributed by Oren Milman in bpo-28332(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28332


File: python.info,  Node: ssl<7>,  Next: sunau,  Prev: socket<7>,  Up: Deprecated Python modules functions and methods

1.8.11.12 ssl
.............

‘ssl.wrap_socket()’ is deprecated.  Use *note
ssl.SSLContext.wrap_socket(): 749. instead.  (Contributed by Christian
Heimes in bpo-28124(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28124


File: python.info,  Node: sunau,  Next: sys<9>,  Prev: ssl<7>,  Up: Deprecated Python modules functions and methods

1.8.11.13 sunau
...............

‘sunau.openfp()’ has been deprecated and will be removed in Python 3.9.
Use ‘sunau.open()’ instead.  (Contributed by Brian Curtin in
bpo-31985(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31985


File: python.info,  Node: sys<9>,  Next: wave,  Prev: sunau,  Up: Deprecated Python modules functions and methods

1.8.11.14 sys
.............

Deprecated ‘sys.set_coroutine_wrapper()’ and
‘sys.get_coroutine_wrapper()’.

The undocumented ‘sys.callstats()’ function has been deprecated and will
be removed in a future Python version.  (Contributed by Victor Stinner
in bpo-28799(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28799


File: python.info,  Node: wave,  Prev: sys<9>,  Up: Deprecated Python modules functions and methods

1.8.11.15 wave
..............

‘wave.openfp()’ has been deprecated and will be removed in Python 3.9.
Use *note wave.open(): b47. instead.  (Contributed by Brian Curtin in
bpo-31985(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31985


File: python.info,  Node: Deprecated functions and types of the C API,  Next: Platform Support Removals,  Prev: Deprecated Python modules functions and methods,  Up: What’s New In Python 3 7

1.8.12 Deprecated functions and types of the C API
--------------------------------------------------

Function *note PySlice_GetIndicesEx(): 431. is deprecated and replaced
with a macro if ‘Py_LIMITED_API’ is not set or set to a value in the
range between ‘0x03050400’ and ‘0x03060000’ (not inclusive), or is
‘0x03060100’ or higher.  (Contributed by Serhiy Storchaka in
bpo-27867(1).)

*note PyOS_AfterFork(): 42f. has been deprecated.  Use *note
PyOS_BeforeFork(): dba, *note PyOS_AfterFork_Parent(): dbb. or *note
PyOS_AfterFork_Child(): 430. instead.  (Contributed by Antoine Pitrou in
bpo-16500(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27867

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16500


File: python.info,  Node: Platform Support Removals,  Next: API and Feature Removals<2>,  Prev: Deprecated functions and types of the C API,  Up: What’s New In Python 3 7

1.8.13 Platform Support Removals
--------------------------------

   * FreeBSD 9 and older are no longer officially supported.

   * For full Unicode support, including within extension modules, *nix
     platforms are now expected to provide at least one of ‘C.UTF-8’
     (full locale), ‘C.utf8’ (full locale) or ‘UTF-8’ (‘LC_CTYPE’-only
     locale) as an alternative to the legacy ‘ASCII’-based ‘C’ locale.

   * OpenSSL 0.9.8 and 1.0.1 are no longer supported, which means
     building CPython 3.7 with SSL/TLS support on older platforms still
     using these versions requires custom build options that link to a
     more recent version of OpenSSL.

     Notably, this issue affects the Debian 8 (aka «jessie») and Ubuntu
     14.04 (aka «Trusty») LTS Linux distributions, as they still use
     OpenSSL 1.0.1 by default.

     Debian 9 («stretch») and Ubuntu 16.04 («xenial»), as well as recent
     releases of other LTS Linux releases (e.g.  RHEL/CentOS 7.5, SLES
     12-SP3), use OpenSSL 1.0.2 or later, and remain supported in the
     default build configuration.

     CPython’s own CI configuration file(1) provides an example of using
     the SSL compatibility testing infrastructure(2) in CPython’s test
     suite to build and link against OpenSSL 1.1.0 rather than an
     outdated system provided OpenSSL.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/blob/v3.7.13/.travis.yml

   (2) 
https://github.com/python/cpython/tree/3.14/Tools/ssl/multissltests.py


File: python.info,  Node: API and Feature Removals<2>,  Next: Module Removals,  Prev: Platform Support Removals,  Up: What’s New In Python 3 7

1.8.14 API and Feature Removals
-------------------------------

The following features and APIs have been removed from Python 3.7:

   * The ‘os.stat_float_times()’ function has been removed.  It was
     introduced in Python 2.3 for backward compatibility with Python
     2.2, and was deprecated since Python 3.1.

   * Unknown escapes consisting of ‘'\'’ and an ASCII letter in
     replacement templates for *note re.sub(): 5a3. were deprecated in
     Python 3.5, and will now cause an error.

   * Removed support of the 'exclude' argument in *note
     tarfile.TarFile.add(): df0.  It was deprecated in Python 2.7 and
     3.2.  Use the 'filter' argument instead.

   * The ‘ntpath.splitunc()’ function was deprecated in Python 3.1, and
     has now been removed.  Use *note splitdrive(): df1. instead.

   * *note collections.namedtuple(): 4e1. no longer supports the
     'verbose' parameter or ‘_source’ attribute which showed the
     generated source code for the named tuple class.  This was part of
     an optimization designed to speed-up class creation.  (Contributed
     by Jelle Zijlstra with further improvements by INADA Naoki, Serhiy
     Storchaka, and Raymond Hettinger in bpo-28638(1).)

   * Functions *note bool(): 3c3, *note float(): 196, *note list(): 24d.
     and *note tuple(): 614. no longer take keyword arguments.  The
     first argument of *note int(): 19b. can now be passed only as
     positional argument.

   * Removed previously deprecated in Python 2.4 classes ‘Plist’, ‘Dict’
     and ‘_InternalDict’ in the *note plistlib: b0. module.  Dict values
     in the result of functions ‘readPlist()’ and ‘readPlistFromBytes()’
     are now normal dicts.  You no longer can use attribute access to
     access items of these dictionaries.

   * The ‘asyncio.windows_utils.socketpair()’ function has been removed.
     Use the *note socket.socketpair(): df2. function instead, it is
     available on all platforms since Python 3.5.
     ‘asyncio.windows_utils.socketpair’ was just an alias to
     ‘socket.socketpair’ on Python 3.5 and newer.

   * *note asyncio: b. no longer exports the *note selectors: c7. and
     ‘_overlapped’ modules as ‘asyncio.selectors’ and
     ‘asyncio._overlapped’.  Replace ‘from asyncio import selectors’
     with ‘import selectors’.

   * Direct instantiation of *note ssl.SSLSocket: ae9. and *note
     ssl.SSLObject: d7c. objects is now prohibited.  The constructors
     were never documented, tested, or designed as public constructors.
     Users were supposed to use ‘ssl.wrap_socket()’ or *note
     ssl.SSLContext: 357.  (Contributed by Christian Heimes in
     bpo-32951(2).)

   * The unused ‘distutils’ ‘install_misc’ command has been removed.
     (Contributed by Eric N. Vander Weele in bpo-29218(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28638

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32951

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29218


File: python.info,  Node: Module Removals,  Next: Windows-only Changes,  Prev: API and Feature Removals<2>,  Up: What’s New In Python 3 7

1.8.15 Module Removals
----------------------

The ‘fpectl’ module has been removed.  It was never enabled by default,
never worked correctly on x86-64, and it changed the Python ABI in ways
that caused unexpected breakage of C extensions.  (Contributed by
Nathaniel J. Smith in bpo-29137(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29137


File: python.info,  Node: Windows-only Changes,  Next: Porting to Python 3 7,  Prev: Module Removals,  Up: What’s New In Python 3 7

1.8.16 Windows-only Changes
---------------------------

The python launcher, (py.exe), can accept 32 & 64 bit specifiers
'without' having to specify a minor version as well.  So ‘py -3-32’ and
‘py -3-64’ become valid as well as ‘py -3.7-32’, also the -'m'-64 and
-'m.n'-64 forms are now accepted to force 64 bit python even if 32 bit
would have otherwise been used.  If the specified version is not
available py.exe will error exit.  (Contributed by Steve Barnes in
bpo-30291(1).)

The launcher can be run as ‘py -0’ to produce a list of the installed
pythons, 'with default marked with an asterisk'.  Running ‘py -0p’ will
include the paths.  If py is run with a version specifier that cannot be
matched it will also print the 'short form' list of available
specifiers.  (Contributed by Steve Barnes in bpo-30362(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30291

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30362


File: python.info,  Node: Porting to Python 3 7,  Next: Notable changes in Python 3 7 1,  Prev: Windows-only Changes,  Up: What’s New In Python 3 7

1.8.17 Porting to Python 3.7
----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code.

* Menu:

* Changes in Python Behavior::
* Changes in the Python API: Changes in the Python API<7>.
* Changes in the C API: Changes in the C API<6>.
* CPython bytecode changes: CPython bytecode changes<6>.
* Windows-only Changes: Windows-only Changes<2>.
* Other CPython implementation changes::


File: python.info,  Node: Changes in Python Behavior,  Next: Changes in the Python API<7>,  Up: Porting to Python 3 7

1.8.17.1 Changes in Python Behavior
...................................

   * *note async: 93c. and *note await: 18d. names are now reserved
     keywords.  Code using these names as identifiers will now raise a
     *note SyntaxError: 18e.  (Contributed by Jelle Zijlstra in
     bpo-30406(1).)

   * PEP 479(2) is enabled for all code in Python 3.7, meaning that
     *note StopIteration: df7. exceptions raised directly or indirectly
     in coroutines and generators are transformed into *note
     RuntimeError: 244. exceptions.  (Contributed by Yury Selivanov in
     bpo-32670(3).)

   * *note object.__aiter__(): df8. methods can no longer be declared as
     asynchronous.  (Contributed by Yury Selivanov in bpo-31709(4).)

   * Due to an oversight, earlier Python versions erroneously accepted
     the following syntax:

          f(1 for x in [1],)

          class C(1 for x in [1]):
              pass

     Python 3.7 now correctly raises a *note SyntaxError: 18e, as a
     generator expression always needs to be directly inside a set of
     parentheses and cannot have a comma on either side, and the
     duplication of the parentheses can be omitted only on calls.
     (Contributed by Serhiy Storchaka in bpo-32012(5) and bpo-32023(6).)

   * When using the *note -m: 23c. switch, the initial working directory
     is now added to *note sys.path: 3e4, rather than an empty string
     (which dynamically denoted the current working directory at the
     time of each import).  Any programs that are checking for the empty
     string, or otherwise relying on the previous behaviour, will need
     to be updated accordingly (e.g.  by also checking for ‘os.getcwd()’
     or ‘os.path.dirname(__main__.__file__)’, depending on why the code
     was checking for the empty string in the first place).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30406

   (2) https://peps.python.org/pep-0479/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32670

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31709

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32012

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32023


File: python.info,  Node: Changes in the Python API<7>,  Next: Changes in the C API<6>,  Prev: Changes in Python Behavior,  Up: Porting to Python 3 7

1.8.17.2 Changes in the Python API
..................................

   * *note socketserver.ThreadingMixIn.server_close: d71. now waits
     until all non-daemon threads complete.  Set the new *note
     socketserver.ThreadingMixIn.block_on_close: d72. class attribute to
     ‘False’ to get the pre-3.7 behaviour.  (Contributed by Victor
     Stinner in bpo-31233(1) and bpo-33540(2).)

   * *note socketserver.ForkingMixIn.server_close: d71. now waits until
     all child processes complete.  Set the new *note
     socketserver.ForkingMixIn.block_on_close: d72. class attribute to
     ‘False’ to get the pre-3.7 behaviour.  (Contributed by Victor
     Stinner in bpo-31151(3) and bpo-33540(4).)

   * The *note locale.localeconv(): dfa. function now temporarily sets
     the ‘LC_CTYPE’ locale to the value of ‘LC_NUMERIC’ in some cases.
     (Contributed by Victor Stinner in bpo-31900(5).)

   * *note pkgutil.walk_packages(): dfb. now raises a *note ValueError:
     2ec. if 'path' is a string.  Previously an empty list was returned.
     (Contributed by Sanyam Khurana in bpo-24744(6).)

   * A format string argument for *note string.Formatter.format(): dfc.
     is now *note positional-only: c7a.  Passing it as a keyword
     argument was deprecated in Python 3.5.  (Contributed by Serhiy
     Storchaka in bpo-29193(7).)

   * Attributes *note key: dfd, *note value: dfe. and *note coded_value:
     dff. of class *note http.cookies.Morsel: e00. are now read-only.
     Assigning to them was deprecated in Python 3.5.  Use the *note
     set(): e01. method for setting them.  (Contributed by Serhiy
     Storchaka in bpo-29192(8).)

   * The 'mode' argument of *note os.makedirs(): 52d. no longer affects
     the file permission bits of newly created intermediate-level
     directories.  To set their file permission bits you can set the
     umask before invoking ‘makedirs()’.  (Contributed by Serhiy
     Storchaka in bpo-19930(9).)

   * The *note struct.Struct.format: e02. type is now *note str: 169.
     instead of *note bytes: 192.  (Contributed by Victor Stinner in
     bpo-21071(10).)

   * ‘cgi.parse_multipart()’ now accepts the 'encoding' and 'errors'
     arguments and returns the same results as ‘FieldStorage’: for
     non-file fields, the value associated to a key is a list of
     strings, not bytes.  (Contributed by Pierre Quentel in
     bpo-29979(11).)

   * Due to internal changes in *note socket: d1, calling *note
     socket.fromshare(): e03. on a socket created by *note socket.share:
     e04. in older Python versions is not supported.

   * ‘repr’ for *note BaseException: 7d8. has changed to not include the
     trailing comma.  Most exceptions are affected by this change.
     (Contributed by Serhiy Storchaka in bpo-30399(12).)

   * ‘repr’ for *note datetime.timedelta: bc5. has changed to include
     the keyword arguments in the output.  (Contributed by Utkarsh
     Upadhyay in bpo-30302(13).)

   * Because *note shutil.rmtree(): 356. is now implemented using the
     *note os.scandir(): c56. function, the user specified handler
     'onerror' is now called with the first argument ‘os.scandir’
     instead of ‘os.listdir’ when listing the directory is failed.

   * Support for nested sets and set operations in regular expressions
     as in Unicode Technical Standard #18(14) might be added in the
     future.  This would change the syntax.  To facilitate this future
     change a *note FutureWarning: 659. will be raised in ambiguous
     cases for the time being.  That include sets starting with a
     literal ‘'['’ or containing literal character sequences ‘'--'’,
     ‘'&&'’, ‘'~~'’, and ‘'||'’.  To avoid a warning, escape them with a
     backslash.  (Contributed by Serhiy Storchaka in bpo-30349(15).)

   * The result of splitting a string on a *note regular expression: be.
     that could match an empty string has been changed.  For example
     splitting on ‘r'\s*'’ will now split not only on whitespaces as it
     did previously, but also on empty strings before all non-whitespace
     characters and just before the end of the string.  The previous
     behavior can be restored by changing the pattern to ‘r'\s+'’.  A
     *note FutureWarning: 659. was emitted for such patterns since
     Python 3.5.

     For patterns that match both empty and non-empty strings, the
     result of searching for all matches may also be changed in other
     cases.  For example in the string ‘'a\n\n'’, the pattern
     ‘r'(?m)^\s*?$'’ will not only match empty strings at positions 2
     and 3, but also the string ‘'\n'’ at positions 2–3.  To match only
     blank lines, the pattern should be rewritten as
     ‘r'(?m)^[^\S\n]*$'’.

     *note re.sub(): 5a3. now replaces empty matches adjacent to a
     previous non-empty match.  For example ‘re.sub('x*', '-', 'abxd')’
     returns now ‘'-a-b--d-'’ instead of ‘'-a-b-d-'’ (the first minus
     between “b” and “d” replaces “x”, and the second minus replaces an
     empty string between “x” and “d”).

     (Contributed by Serhiy Storchaka in bpo-25054(16) and
     bpo-32308(17).)

   * Change *note re.escape(): e05. to only escape regex special
     characters instead of escaping all characters other than ASCII
     letters, numbers, and ‘'_'’.  (Contributed by Serhiy Storchaka in
     bpo-29995(18).)

   * *note tracemalloc.Traceback: d91. frames are now sorted from oldest
     to most recent to be more consistent with *note traceback: 104.
     (Contributed by Jesse Bakker in bpo-32121(19).)

   * On OSes that support *note socket.SOCK_NONBLOCK: e06. or *note
     socket.SOCK_CLOEXEC: e07. bit flags, the *note socket.type: e08. no
     longer has them applied.  Therefore, checks like ‘if sock.type ==
     socket.SOCK_STREAM’ work as expected on all platforms.
     (Contributed by Yury Selivanov in bpo-32331(20).)

   * On Windows the default for the 'close_fds' argument of *note
     subprocess.Popen: 4b8. was changed from *note False: d2d. to *note
     True: e09. when redirecting the standard handles.  If you
     previously depended on handles being inherited when using *note
     subprocess.Popen: 4b8. with standard io redirection, you will have
     to pass ‘close_fds=False’ to preserve the previous behaviour, or
     use *note STARTUPINFO.lpAttributeList: e0a.

   * *note importlib.machinery.PathFinder.invalidate_caches(): e0b. –
     which implicitly affects *note importlib.invalidate_caches(): e0c.
     – now deletes entries in *note sys.path_importer_cache: 7fb. which
     are set to ‘None’.  (Contributed by Brett Cannon in bpo-33169(21).)

   * In *note asyncio: b, *note loop.sock_recv(): e0d, *note
     loop.sock_sendall(): e0e, *note loop.sock_accept(): e0f, *note
     loop.getaddrinfo(): e10, *note loop.getnameinfo(): e11. have been
     changed to be proper coroutine methods to match their
     documentation.  Previously, these methods returned *note
     asyncio.Future: dc8. instances.  (Contributed by Yury Selivanov in
     bpo-32327(22).)

   * *note asyncio.Server.sockets: e12. now returns a copy of the
     internal list of server sockets, instead of returning it directly.
     (Contributed by Yury Selivanov in bpo-32662(23).)

   * *note Struct.format: e02. is now a *note str: 169. instance instead
     of a *note bytes: 192. instance.  (Contributed by Victor Stinner in
     bpo-21071(24).)

   * *note argparse: 7. subparsers can now be made mandatory by passing
     ‘required=True’ to *note ArgumentParser.add_subparsers(): e13.
     (Contributed by Anthony Sottile in bpo-26510(25).)

   * *note ast.literal_eval(): e14. is now stricter.  Addition and
     subtraction of arbitrary numbers are no longer allowed.
     (Contributed by Serhiy Storchaka in bpo-31778(26).)

   * *note Calendar.itermonthdates: e15. will now consistently raise an
     exception when a date falls outside of the ‘0001-01-01’ through
     ‘9999-12-31’ range.  To support applications that cannot tolerate
     such exceptions, the new *note Calendar.itermonthdays3: e16. and
     *note Calendar.itermonthdays4: e17. can be used.  The new methods
     return tuples and are not restricted by the range supported by
     *note datetime.date: 1fa.  (Contributed by Alexander Belopolsky in
     bpo-28292(27).)

   * *note collections.ChainMap: e18. now preserves the order of the
     underlying mappings.  (Contributed by Raymond Hettinger in
     bpo-32792(28).)

   * The ‘submit()’ method of *note
     concurrent.futures.ThreadPoolExecutor: 94a. and *note
     concurrent.futures.ProcessPoolExecutor: 1d6. now raises a *note
     RuntimeError: 244. if called during interpreter shutdown.
     (Contributed by Mark Nemec in bpo-33097(29).)

   * The *note configparser.ConfigParser: 4df. constructor now uses
     ‘read_dict()’ to process the default values, making its behavior
     consistent with the rest of the parser.  Non-string keys and values
     in the defaults dictionary are now being implicitly converted to
     strings.  (Contributed by James Tocknell in bpo-23835(30).)

   * Several undocumented internal imports were removed.  One example is
     that ‘os.errno’ is no longer available; use ‘import errno’ directly
     instead.  Note that such undocumented internal imports may be
     removed any time without notice, even in micro version releases.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31233

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33540

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31151

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33540

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31900

   (6) https://bugs.python.org/issue?@action=redirect&bpo=24744

   (7) https://bugs.python.org/issue?@action=redirect&bpo=29193

   (8) https://bugs.python.org/issue?@action=redirect&bpo=29192

   (9) https://bugs.python.org/issue?@action=redirect&bpo=19930

   (10) https://bugs.python.org/issue?@action=redirect&bpo=21071

   (11) https://bugs.python.org/issue?@action=redirect&bpo=29979

   (12) https://bugs.python.org/issue?@action=redirect&bpo=30399

   (13) https://bugs.python.org/issue?@action=redirect&bpo=30302

   (14) https://unicode.org/reports/tr18/

   (15) https://bugs.python.org/issue?@action=redirect&bpo=30349

   (16) https://bugs.python.org/issue?@action=redirect&bpo=25054

   (17) https://bugs.python.org/issue?@action=redirect&bpo=32308

   (18) https://bugs.python.org/issue?@action=redirect&bpo=29995

   (19) https://bugs.python.org/issue?@action=redirect&bpo=32121

   (20) https://bugs.python.org/issue?@action=redirect&bpo=32331

   (21) https://bugs.python.org/issue?@action=redirect&bpo=33169

   (22) https://bugs.python.org/issue?@action=redirect&bpo=32327

   (23) https://bugs.python.org/issue?@action=redirect&bpo=32662

   (24) https://bugs.python.org/issue?@action=redirect&bpo=21071

   (25) https://bugs.python.org/issue?@action=redirect&bpo=26510

   (26) https://bugs.python.org/issue?@action=redirect&bpo=31778

   (27) https://bugs.python.org/issue?@action=redirect&bpo=28292

   (28) https://bugs.python.org/issue?@action=redirect&bpo=32792

   (29) https://bugs.python.org/issue?@action=redirect&bpo=33097

   (30) https://bugs.python.org/issue?@action=redirect&bpo=23835


File: python.info,  Node: Changes in the C API<6>,  Next: CPython bytecode changes<6>,  Prev: Changes in the Python API<7>,  Up: Porting to Python 3 7

1.8.17.3 Changes in the C API
.............................

The function *note PySlice_GetIndicesEx(): 431. is considered unsafe for
resizable sequences.  If the slice indices are not instances of *note
int: 19b, but objects that implement the ‘__index__()’ method, the
sequence can be resized after passing its length to
‘PySlice_GetIndicesEx()’.  This can lead to returning indices out of the
length of the sequence.  For avoiding possible problems use new
functions *note PySlice_Unpack(): 432. and *note
PySlice_AdjustIndices(): 433.  (Contributed by Serhiy Storchaka in
bpo-27867(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27867


File: python.info,  Node: CPython bytecode changes<6>,  Next: Windows-only Changes<2>,  Prev: Changes in the C API<6>,  Up: Porting to Python 3 7

1.8.17.4 CPython bytecode changes
.................................

There are two new opcodes: ‘LOAD_METHOD’ and ‘CALL_METHOD’.
(Contributed by Yury Selivanov and INADA Naoki in bpo-26110(1).)

The ‘STORE_ANNOTATION’ opcode has been removed.  (Contributed by Mark
Shannon in bpo-32550(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26110

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32550


File: python.info,  Node: Windows-only Changes<2>,  Next: Other CPython implementation changes,  Prev: CPython bytecode changes<6>,  Up: Porting to Python 3 7

1.8.17.5 Windows-only Changes
.............................

The file used to override *note sys.path: 3e4. is now called
‘<python-executable>._pth’ instead of ‘'sys.path'’.  See *note Finding
modules: e1c. for more information.  (Contributed by Steve Dower in
bpo-28137(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28137


File: python.info,  Node: Other CPython implementation changes,  Prev: Windows-only Changes<2>,  Up: Porting to Python 3 7

1.8.17.6 Other CPython implementation changes
.............................................

In preparation for potential future changes to the public CPython
runtime initialization API (see PEP 432(1) for an initial, but somewhat
outdated, draft), CPython’s internal startup and configuration
management logic has been significantly refactored.  While these updates
are intended to be entirely transparent to both embedding applications
and users of the regular CPython CLI, they’re being mentioned here as
the refactoring changes the internal order of various operations during
interpreter startup, and hence may uncover previously latent defects,
either in embedding applications, or in CPython itself.  (Initially
contributed by Nick Coghlan and Eric Snow as part of bpo-22257(2), and
further updated by Nick, Eric, and Victor Stinner in a number of other
issues).  Some known details affected:

   * ‘PySys_AddWarnOptionUnicode()’ is not currently usable by embedding
     applications due to the requirement to create a Unicode object
     prior to calling ‘Py_Initialize’.  Use ‘PySys_AddWarnOption()’
     instead.

   * warnings filters added by an embedding application with
     ‘PySys_AddWarnOption()’ should now more consistently take
     precedence over the default filters set by the interpreter

Due to changes in the way the default warnings filters are configured,
setting *note Py_BytesWarningFlag: 406. to a value greater than one is
no longer sufficient to both emit *note BytesWarning: e1e. messages and
have them converted to exceptions.  Instead, the flag must be set (to
cause the warnings to be emitted in the first place), and an explicit
‘error::BytesWarning’ warnings filter added to convert them to
exceptions.

Due to a change in the way docstrings are handled by the compiler, the
implicit ‘return None’ in a function body consisting solely of a
docstring is now marked as occurring on the same line as the docstring,
not on the function’s header line.

The current exception state has been moved from the frame object to the
co-routine.  This simplified the interpreter and fixed a couple of
obscure bugs caused by having swap exception state when entering or
exiting a generator.  (Contributed by Mark Shannon in bpo-25612(3).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0432/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22257

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25612


File: python.info,  Node: Notable changes in Python 3 7 1,  Next: Notable changes in Python 3 7 2,  Prev: Porting to Python 3 7,  Up: What’s New In Python 3 7

1.8.18 Notable changes in Python 3.7.1
--------------------------------------

Starting in 3.7.1, *note Py_Initialize(): 460. now consistently reads
and respects all of the same environment settings as *note Py_Main():
e20. (in earlier Python versions, it respected an ill-defined subset of
those environment variables, while in Python 3.7.0 it didn’t read any of
them due to bpo-34247(1)).  If this behavior is unwanted, set *note
Py_IgnoreEnvironmentFlag: 40a. to 1 before calling *note
Py_Initialize(): 460.

In 3.7.1 the C API for Context Variables *note was updated: e21. to use
*note PyObject: 5df. pointers.  See also bpo-34762(2).

In 3.7.1 the *note tokenize: 101. module now implicitly emits a
‘NEWLINE’ token when provided with input that does not have a trailing
new line.  This behavior now matches what the C tokenizer does
internally.  (Contributed by Ammar Askar in bpo-33899(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34247

   (2) https://bugs.python.org/issue?@action=redirect&bpo=34762

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33899


File: python.info,  Node: Notable changes in Python 3 7 2,  Next: Notable changes in Python 3 7 6,  Prev: Notable changes in Python 3 7 1,  Up: What’s New In Python 3 7

1.8.19 Notable changes in Python 3.7.2
--------------------------------------

In 3.7.2, *note venv: 117. on Windows no longer copies the original
binaries, but creates redirector scripts named ‘python.exe’ and
‘pythonw.exe’ instead.  This resolves a long standing issue where all
virtual environments would have to be upgraded or recreated with each
Python update.  However, note that this release will still require
recreation of virtual environments in order to get the new scripts.


File: python.info,  Node: Notable changes in Python 3 7 6,  Next: Notable changes in Python 3 7 10,  Prev: Notable changes in Python 3 7 2,  Up: What’s New In Python 3 7

1.8.20 Notable changes in Python 3.7.6
--------------------------------------

Due to significant security concerns, the 'reuse_address' parameter of
*note asyncio.loop.create_datagram_endpoint(): 93d. is no longer
supported.  This is because of the behavior of the socket option
‘SO_REUSEADDR’ in UDP. For more details, see the documentation for
‘loop.create_datagram_endpoint()’.  (Contributed by Kyle Stanley,
Antoine Pitrou, and Yury Selivanov in bpo-37228(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37228


File: python.info,  Node: Notable changes in Python 3 7 10,  Next: Notable changes in Python 3 7 11,  Prev: Notable changes in Python 3 7 6,  Up: What’s New In Python 3 7

1.8.21 Notable changes in Python 3.7.10
---------------------------------------

Earlier Python versions allowed using both ‘;’ and ‘&’ as query
parameter separators in *note urllib.parse.parse_qs(): 31f. and *note
urllib.parse.parse_qsl(): 31e.  Due to security concerns, and to conform
with newer W3C recommendations, this has been changed to allow only a
single separator key, with ‘&’ as the default.  This change also affects
‘cgi.parse()’ and ‘cgi.parse_multipart()’ as they use the affected
functions internally.  For more details, please see their respective
documentation.  (Contributed by Adam Goldschmidt, Senthil Kumaran and
Ken Jin in bpo-42967(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42967


File: python.info,  Node: Notable changes in Python 3 7 11,  Next: Notable security feature in 3 7 14,  Prev: Notable changes in Python 3 7 10,  Up: What’s New In Python 3 7

1.8.22 Notable changes in Python 3.7.11
---------------------------------------

A security fix alters the *note ftplib.FTP: af8. behavior to not trust
the IPv4 address sent from the remote server when setting up a passive
data channel.  We reuse the ftp server IP address instead.  For unusual
code requiring the old behavior, set a ‘trust_server_pasv_ipv4_address’
attribute on your FTP instance to ‘True’.  (See gh-87451(1))

The presence of newline or tab characters in parts of a URL allows for
some forms of attacks.  Following the WHATWG specification that updates
RFC 3986, ASCII newline ‘\n’, ‘\r’ and tab ‘\t’ characters are stripped
from the URL by the parser *note urllib.parse(): 110. preventing such
attacks.  The removal characters are controlled by a new module level
variable ‘urllib.parse._UNSAFE_URL_BYTES_TO_REMOVE’.  (See gh-88048(2))

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/87451

   (2) https://github.com/python/cpython/issues/88048


File: python.info,  Node: Notable security feature in 3 7 14,  Prev: Notable changes in Python 3 7 11,  Up: What’s New In Python 3 7

1.8.23 Notable security feature in 3.7.14
-----------------------------------------

Converting between *note int: 19b. and *note str: 169. in bases other
than 2 (binary), 4, 8 (octal), 16 (hexadecimal), or 32 such as base 10
(decimal) now raises a *note ValueError: 2ec. if the number of digits in
string form is above a limit to avoid potential denial of service
attacks due to the algorithmic complexity.  This is a mitigation for CVE
2020-10735(1).  This limit can be configured or disabled by environment
variable, command line flag, or *note sys: df. APIs.  See the *note
integer string conversion length limitation: 80c. documentation.  The
default limit is 4300 digits in string form.

   ---------- Footnotes ----------

   (1) https://www.cve.org/CVERecord?id=CVE-2020-10735


File: python.info,  Node: What’s New In Python 3 6,  Next: What’s New In Python 3 5,  Prev: What’s New In Python 3 7,  Up: Novità in Python

1.9 What’s New In Python 3.6
============================


Editors: Elvis Pranskevichus <<elvis@magic.io>>, Yury Selivanov
<<yury@magic.io>>

This article explains the new features in Python 3.6, compared to 3.5.
Python 3.6 was released on December 23, 2016.  See the changelog(1) for
a full list of changes.

Vedi anche
..........

PEP 494(2) - Python 3.6 Release Schedule

* Menu:

* Summary – Release highlights: Summary – Release highlights<6>.
* New Features: New Features<11>.
* Other Language Changes: Other Language Changes<7>.
* New Modules: New Modules<7>.
* Improved Modules: Improved Modules<7>.
* Optimizations: Optimizations<8>.
* Build and C API Changes: Build and C API Changes<2>.
* Other Improvements::
* Deprecated: Deprecated<8>.
* Removed: Removed<8>.
* Porting to Python 3.6: Porting to Python 3 6.
* Notable changes in Python 3.6.2: Notable changes in Python 3 6 2.
* Notable changes in Python 3.6.4: Notable changes in Python 3 6 4.
* Notable changes in Python 3.6.5: Notable changes in Python 3 6 5.
* Notable changes in Python 3.6.7: Notable changes in Python 3 6 7.
* Notable changes in Python 3.6.10: Notable changes in Python 3 6 10.
* Notable changes in Python 3.6.13: Notable changes in Python 3 6 13.
* Notable changes in Python 3.6.14: Notable changes in Python 3 6 14.

   ---------- Footnotes ----------

   (1) https://docs.python.org/3.6/whatsnew/changelog.html

   (2) https://peps.python.org/pep-0494/


File: python.info,  Node: Summary – Release highlights<6>,  Next: New Features<11>,  Up: What’s New In Python 3 6

1.9.1 Summary – Release highlights
----------------------------------

New syntax features:

   * *note PEP 498: e2b, formatted string literals.

   * *note PEP 515: e2c, underscores in numeric literals.

   * *note PEP 526: e2d, syntax for variable annotations.

   * *note PEP 525: e2e, asynchronous generators.

   * *note PEP 530: e2f.: asynchronous comprehensions.

New library modules:

   * *note secrets: c5.: *note PEP 506 – Adding A Secrets Module To The
     Standard Library: e30.

CPython implementation improvements:

   * The *note dict: cbf. type has been reimplemented to use a *note
     more compact representation: e31. based on a proposal by Raymond
     Hettinger(1) and similar to the PyPy dict implementation(2).  This
     resulted in dictionaries using 20% to 25% less memory when compared
     to Python 3.5.

   * Customization of class creation has been simplified with the *note
     new protocol: e32.

   * The class attribute definition order is *note now preserved: e33.

   * The order of elements in ‘**kwargs’ now *note corresponds to the
     order: e34. in which keyword arguments were passed to the function.

   * DTrace and SystemTap *note probing support: e35. has been added.

   * The new *note PYTHONMALLOC: e36. environment variable can now be
     used to debug the interpreter memory allocation and access errors.

Significant improvements in the standard library:

   * The *note asyncio: b. module has received new features, significant
     usability and performance improvements, and a fair amount of bug
     fixes.  Starting with Python 3.6 the ‘asyncio’ module is no longer
     provisional and its API is considered stable.

   * A new *note file system path protocol: e37. has been implemented to
     support *note path-like objects: 5a1.  All standard library
     functions operating on paths have been updated to work with the new
     protocol.

   * The *note datetime: 34. module has gained support for *note Local
     Time Disambiguation: e38.

   * The *note typing: 10a. module received a number of *note
     improvements: e39.

   * The *note tracemalloc: 105. module has been significantly reworked
     and is now used to provide better output for *note ResourceWarning:
     54d. as well as provide better diagnostics for memory allocation
     errors.  See the *note PYTHONMALLOC section: e36. for more
     information.

Security improvements:

   * The new *note secrets: c5. module has been added to simplify the
     generation of cryptographically strong pseudo-random numbers
     suitable for managing secrets such as account authentication,
     tokens, and similar.

   * On Linux, *note os.urandom(): 747. now blocks until the system
     urandom entropy pool is initialized to increase the security.  See
     the PEP 524(3) for the rationale.

   * The *note hashlib: 6c. and *note ssl: d5. modules now support
     OpenSSL 1.1.0.

   * The default settings and feature set of the *note ssl: d5. module
     have been improved.

   * The *note hashlib: 6c. module received support for the BLAKE2,
     SHA-3 and SHAKE hash algorithms and the *note scrypt(): e3a. key
     derivation function.

Windows improvements:

   * *note PEP 528: e3b. and *note PEP 529: e3c, Windows filesystem and
     console encoding changed to UTF-8.

   * The ‘py.exe’ launcher, when used interactively, no longer prefers
     Python 2 over Python 3 when the user doesn’t specify a version (via
     command line arguments or a config file).  Handling of shebang
     lines remains unchanged - «python» refers to Python 2 in that case.

   * ‘python.exe’ and ‘pythonw.exe’ have been marked as long-path aware,
     which means that the 260 character path limit may no longer apply.
     See *note removing the MAX_PATH limitation: e3d. for details.

   * A ‘._pth’ file can be added to force isolated mode and fully
     specify all search paths to avoid registry and environment lookup.
     See *note the documentation: e1c. for more information.

   * A ‘python36.zip’ file now works as a landmark to infer *note
     PYTHONHOME: 3f0.  See *note the documentation: e1c. for more
     information.

   ---------- Footnotes ----------

   (1) 
https://mail.python.org/pipermail/python-dev/2012-December/123028.html

   (2) 
https://morepypy.blogspot.com/2015/01/faster-more-memory-efficient-and-more.html

   (3) https://peps.python.org/pep-0524/


File: python.info,  Node: New Features<11>,  Next: Other Language Changes<7>,  Prev: Summary – Release highlights<6>,  Up: What’s New In Python 3 6

1.9.2 New Features
------------------

* Menu:

* PEP 498; Formatted string literals: PEP 498 Formatted string literals.
* PEP 526; Syntax for variable annotations: PEP 526 Syntax for variable annotations.
* PEP 515; Underscores in Numeric Literals: PEP 515 Underscores in Numeric Literals.
* PEP 525; Asynchronous Generators: PEP 525 Asynchronous Generators.
* PEP 530; Asynchronous Comprehensions: PEP 530 Asynchronous Comprehensions.
* PEP 487; Simpler customization of class creation: PEP 487 Simpler customization of class creation.
* PEP 487; Descriptor Protocol Enhancements: PEP 487 Descriptor Protocol Enhancements.
* PEP 519; Adding a file system path protocol: PEP 519 Adding a file system path protocol.
* PEP 495; Local Time Disambiguation: PEP 495 Local Time Disambiguation.
* PEP 529; Change Windows filesystem encoding to UTF-8: PEP 529 Change Windows filesystem encoding to UTF-8.
* PEP 528; Change Windows console encoding to UTF-8: PEP 528 Change Windows console encoding to UTF-8.
* PEP 520; Preserving Class Attribute Definition Order: PEP 520 Preserving Class Attribute Definition Order.
* PEP 468; Preserving Keyword Argument Order: PEP 468 Preserving Keyword Argument Order.
* New dict implementation::
* PEP 523; Adding a frame evaluation API to CPython: PEP 523 Adding a frame evaluation API to CPython.
* PYTHONMALLOC environment variable::
* DTrace and SystemTap probing support::


File: python.info,  Node: PEP 498 Formatted string literals,  Next: PEP 526 Syntax for variable annotations,  Up: New Features<11>

1.9.2.1 PEP 498: Formatted string literals
..........................................

PEP 498(1) introduces a new kind of string literals: 'f-strings', or
*note formatted string literals: 19a.

Formatted string literals are prefixed with ‘'f'’ and are similar to the
format strings accepted by *note str.format(): 834.  They contain
replacement fields surrounded by curly braces.  The replacement fields
are expressions, which are evaluated at run time, and then formatted
using the *note format(): 199. protocol:

     >>> name = "Fred"
     >>> f"He said his name is {name}."
     'He said his name is Fred.'
     >>> width = 10
     >>> precision = 4
     >>> value = decimal.Decimal("12.34567")
     >>> f"result: {value:{width}.{precision}}"  # nested fields
     'result:      12.35'

Vedi anche
..........

PEP 498(2) – Literal String Interpolation.

     PEP written and implemented by Eric V. Smith.

*note Feature documentation: 19a.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0498/

   (2) https://peps.python.org/pep-0498/


File: python.info,  Node: PEP 526 Syntax for variable annotations,  Next: PEP 515 Underscores in Numeric Literals,  Prev: PEP 498 Formatted string literals,  Up: New Features<11>

1.9.2.2 PEP 526: Syntax for variable annotations
................................................

PEP 484(1) introduced the standard for type annotations of function
parameters, a.k.a.  type hints.  This PEP adds syntax to Python for
annotating the types of variables including class variables and instance
variables:

     primes: List[int] = []

     captain: str  # Note: no initial value!

     class Starship:
         stats: Dict[str, int] = {}

Just as for function annotations, the Python interpreter does not attach
any particular meaning to variable annotations and only stores them in
the ‘__annotations__’ attribute of a class or module.

In contrast to variable declarations in statically typed languages, the
goal of annotation syntax is to provide an easy way to specify
structured type metadata for third party tools and libraries via the
abstract syntax tree and the ‘__annotations__’ attribute.

Vedi anche
..........

PEP 526(2) – Syntax for variable annotations.

     PEP written by Ryan Gonzalez, Philip House, Ivan Levkivskyi, Lisa
     Roach, and Guido van Rossum.  Implemented by Ivan Levkivskyi.

Tools that use or will use the new syntax: mypy(3), pytype(4), PyCharm,
etc.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0526/

   (3) https://www.mypy-lang.org/

   (4) https://github.com/google/pytype


File: python.info,  Node: PEP 515 Underscores in Numeric Literals,  Next: PEP 525 Asynchronous Generators,  Prev: PEP 526 Syntax for variable annotations,  Up: New Features<11>

1.9.2.3 PEP 515: Underscores in Numeric Literals
................................................

PEP 515(1) adds the ability to use underscores in numeric literals for
improved readability.  For example:

     >>> 1_000_000_000_000_000
     1000000000000000
     >>> 0x_FF_FF_FF_FF
     4294967295

Single underscores are allowed between digits and after any base
specifier.  Leading, trailing, or multiple underscores in a row are not
allowed.

The *note string formatting: 4fa. language also now has support for the
‘'_'’ option to signal the use of an underscore for a thousands
separator for floating-point presentation types and for integer
presentation type ‘'d'’.  For integer presentation types ‘'b'’, ‘'o'’,
‘'x'’, and ‘'X'’, underscores will be inserted every 4 digits:

     >>> '{:_}'.format(1000000)
     '1_000_000'
     >>> '{:_x}'.format(0xFFFFFFFF)
     'ffff_ffff'

Vedi anche
..........

PEP 515(2) – Underscores in Numeric Literals

     PEP written by Georg Brandl and Serhiy Storchaka.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0515/

   (2) https://peps.python.org/pep-0515/


File: python.info,  Node: PEP 525 Asynchronous Generators,  Next: PEP 530 Asynchronous Comprehensions,  Prev: PEP 515 Underscores in Numeric Literals,  Up: New Features<11>

1.9.2.4 PEP 525: Asynchronous Generators
........................................

PEP 492(1) introduced support for native coroutines and ‘async’ /
‘await’ syntax to Python 3.5.  A notable limitation of the Python 3.5
implementation is that it was not possible to use ‘await’ and ‘yield’ in
the same function body.  In Python 3.6 this restriction has been lifted,
making it possible to define 'asynchronous generators':

     async def ticker(delay, to):
         """Yield numbers from 0 to *to* every *delay* seconds."""
         for i in range(to):
             yield i
             await asyncio.sleep(delay)

The new syntax allows for faster and more concise code.

Vedi anche
..........

PEP 525(2) – Asynchronous Generators

     PEP written and implemented by Yury Selivanov.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0492/

   (2) https://peps.python.org/pep-0525/


File: python.info,  Node: PEP 530 Asynchronous Comprehensions,  Next: PEP 487 Simpler customization of class creation,  Prev: PEP 525 Asynchronous Generators,  Up: New Features<11>

1.9.2.5 PEP 530: Asynchronous Comprehensions
............................................

PEP 530(1) adds support for using ‘async for’ in list, set, dict
comprehensions and generator expressions:

     result = [i async for i in aiter() if i % 2]

Additionally, ‘await’ expressions are supported in all kinds of
comprehensions:

     result = [await fun() for fun in funcs if await condition()]

Vedi anche
..........

PEP 530(2) – Asynchronous Comprehensions

     PEP written and implemented by Yury Selivanov.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0530/

   (2) https://peps.python.org/pep-0530/


File: python.info,  Node: PEP 487 Simpler customization of class creation,  Next: PEP 487 Descriptor Protocol Enhancements,  Prev: PEP 530 Asynchronous Comprehensions,  Up: New Features<11>

1.9.2.6 PEP 487: Simpler customization of class creation
........................................................

It is now possible to customize subclass creation without using a
metaclass.  The new ‘__init_subclass__’ classmethod will be called on
the base class whenever a new subclass is created:

     class PluginBase:
         subclasses = []

         def __init_subclass__(cls, **kwargs):
             super().__init_subclass__(**kwargs)
             cls.subclasses.append(cls)

     class Plugin1(PluginBase):
         pass

     class Plugin2(PluginBase):
         pass

In order to allow zero-argument *note super(): 1a6. calls to work
correctly from *note __init_subclass__(): 844. implementations, custom
metaclasses must ensure that the new ‘__classcell__’ namespace entry is
propagated to ‘type.__new__’ (as described in *note Creating the class
object: e46.).

Vedi anche
..........

PEP 487(1) – Simpler customization of class creation

     PEP written and implemented by Martin Teichmann.

*note Feature documentation: e47.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0487/


File: python.info,  Node: PEP 487 Descriptor Protocol Enhancements,  Next: PEP 519 Adding a file system path protocol,  Prev: PEP 487 Simpler customization of class creation,  Up: New Features<11>

1.9.2.7 PEP 487: Descriptor Protocol Enhancements
.................................................

PEP 487(1) extends the descriptor protocol to include the new optional
*note __set_name__(): e4a. method.  Whenever a new class is defined, the
new method will be called on all descriptors included in the definition,
providing them with a reference to the class being defined and the name
given to the descriptor within the class namespace.  In other words,
instances of descriptors can now know the attribute name of the
descriptor in the owner class:

     class IntField:
         def __get__(self, instance, owner):
             return instance.__dict__[self.name]

         def __set__(self, instance, value):
             if not isinstance(value, int):
                 raise ValueError(f'expecting integer in {self.name}')
             instance.__dict__[self.name] = value

         # this is the new initializer:
         def __set_name__(self, owner, name):
             self.name = name

     class Model:
         int_field = IntField()

Vedi anche
..........

PEP 487(2) – Simpler customization of class creation

     PEP written and implemented by Martin Teichmann.

*note Feature documentation: e4b.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0487/

   (2) https://peps.python.org/pep-0487/


File: python.info,  Node: PEP 519 Adding a file system path protocol,  Next: PEP 495 Local Time Disambiguation,  Prev: PEP 487 Descriptor Protocol Enhancements,  Up: New Features<11>

1.9.2.8 PEP 519: Adding a file system path protocol
...................................................

File system paths have historically been represented as *note str: 169.
or *note bytes: 192. objects.  This has led to people who write code
which operate on file system paths to assume that such objects are only
one of those two types (an *note int: 19b. representing a file
descriptor does not count as that is not a file path).  Unfortunately
that assumption prevents alternative object representations of file
system paths like *note pathlib: a8. from working with pre-existing
code, including Python’s standard library.

To fix this situation, a new interface represented by *note os.PathLike:
e4d. has been defined.  By implementing the *note __fspath__(): e4e.
method, an object signals that it represents a path.  An object can then
provide a low-level representation of a file system path as a *note str:
169. or *note bytes: 192. object.  This means an object is considered
*note path-like: 5a1. if it implements *note os.PathLike: e4d. or is a
*note str: 169. or *note bytes: 192. object which represents a file
system path.  Code can use *note os.fspath(): e4f, *note os.fsdecode():
e50, or *note os.fsencode(): e51. to explicitly get a *note str: 169.
and/or *note bytes: 192. representation of a path-like object.

The built-in *note open(): 316. function has been updated to accept
*note os.PathLike: e4d. objects, as have all relevant functions in the
*note os: a5. and *note os.path: a6. modules, and most other functions
and classes in the standard library.  The *note os.DirEntry: 6c4. class
and relevant classes in *note pathlib: a8. have also been updated to
implement *note os.PathLike: e4d.

The hope is that updating the fundamental functions for operating on
file system paths will lead to third-party code to implicitly support
all *note path-like objects: 5a1. without any code changes, or at least
very minimal ones (e.g.  calling *note os.fspath(): e4f. at the
beginning of code before operating on a path-like object).

Here are some examples of how the new interface allows for *note
pathlib.Path: 266. to be used more easily and transparently with
pre-existing code:

     >>> import pathlib
     >>> with open(pathlib.Path("README")) as f:
     ...     contents = f.read()
     ...
     >>> import os.path
     >>> os.path.splitext(pathlib.Path("some_file.txt"))
     ('some_file', '.txt')
     >>> os.path.join("/a/b", pathlib.Path("c"))
     '/a/b/c'
     >>> import os
     >>> os.fspath(pathlib.Path("some_file.txt"))
     'some_file.txt'

(Implemented by Brett Cannon, Ethan Furman, Dusty Phillips, and Jelle
Zijlstra.)

Vedi anche
..........

PEP 519(1) – Adding a file system path protocol

     PEP written by Brett Cannon and Koos Zevenhoven.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0519/


File: python.info,  Node: PEP 495 Local Time Disambiguation,  Next: PEP 529 Change Windows filesystem encoding to UTF-8,  Prev: PEP 519 Adding a file system path protocol,  Up: New Features<11>

1.9.2.9 PEP 495: Local Time Disambiguation
..........................................

In most world locations, there have been and will be times when local
clocks are moved back.  In those times, intervals are introduced in
which local clocks show the same time twice in the same day.  In these
situations, the information displayed on a local clock (or stored in a
Python datetime instance) is insufficient to identify a particular
moment in time.

PEP 495(1) adds the new 'fold' attribute to instances of *note
datetime.datetime: 4e3. and *note datetime.time: 1fb. classes to
differentiate between two moments in time for which local times are the
same:

     >>> u0 = datetime(2016, 11, 6, 4, tzinfo=timezone.utc)
     >>> for i in range(4):
     ...     u = u0 + i*HOUR
     ...     t = u.astimezone(Eastern)
     ...     print(u.time(), 'UTC =', t.time(), t.tzname(), t.fold)
     ...
     04:00:00 UTC = 00:00:00 EDT 0
     05:00:00 UTC = 01:00:00 EDT 0
     06:00:00 UTC = 01:00:00 EST 1
     07:00:00 UTC = 02:00:00 EST 0

The values of the *note fold: e53. attribute have the value ‘0’ for all
instances except those that represent the second (chronologically)
moment in time in an ambiguous case.

Vedi anche
..........

PEP 495(2) – Local Time Disambiguation

     PEP written by Alexander Belopolsky and Tim Peters, implementation
     by Alexander Belopolsky.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0495/

   (2) https://peps.python.org/pep-0495/


File: python.info,  Node: PEP 529 Change Windows filesystem encoding to UTF-8,  Next: PEP 528 Change Windows console encoding to UTF-8,  Prev: PEP 495 Local Time Disambiguation,  Up: New Features<11>

1.9.2.10 PEP 529: Change Windows filesystem encoding to UTF-8
.............................................................

Representing filesystem paths is best performed with str (Unicode)
rather than bytes.  However, there are some situations where using bytes
is sufficient and correct.

Prior to Python 3.6, data loss could result when using bytes paths on
Windows.  With this change, using bytes to represent paths is now
supported on Windows, provided those bytes are encoded with the encoding
returned by *note sys.getfilesystemencoding(): e55, which now defaults
to ‘'utf-8'’.

Applications that do not use str to represent paths should use *note
os.fsencode(): e51. and *note os.fsdecode(): e50. to ensure their bytes
are correctly encoded.  To revert to the previous behaviour, set *note
PYTHONLEGACYWINDOWSFSENCODING: 33f. or call *note
sys._enablelegacywindowsfsencoding(): 33e.

See PEP 529(1) for more information and discussion of code modifications
that may be required.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0529/


File: python.info,  Node: PEP 528 Change Windows console encoding to UTF-8,  Next: PEP 520 Preserving Class Attribute Definition Order,  Prev: PEP 529 Change Windows filesystem encoding to UTF-8,  Up: New Features<11>

1.9.2.11 PEP 528: Change Windows console encoding to UTF-8
..........................................................

The default console on Windows will now accept all Unicode characters
and provide correctly read str objects to Python code.  ‘sys.stdin’,
‘sys.stdout’ and ‘sys.stderr’ now default to utf-8 encoding.

This change only applies when using an interactive console, and not when
redirecting files or pipes.  To revert to the previous behaviour for
interactive console use, set *note PYTHONLEGACYWINDOWSSTDIO: e57.

Vedi anche
..........

PEP 528(1) – Change Windows console encoding to UTF-8

     PEP written and implemented by Steve Dower.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0528/


File: python.info,  Node: PEP 520 Preserving Class Attribute Definition Order,  Next: PEP 468 Preserving Keyword Argument Order,  Prev: PEP 528 Change Windows console encoding to UTF-8,  Up: New Features<11>

1.9.2.12 PEP 520: Preserving Class Attribute Definition Order
.............................................................

Attributes in a class definition body have a natural ordering: the same
order in which the names appear in the source.  This order is now
preserved in the new class’s *note __dict__: e59. attribute.

Also, the effective default class 'execution' namespace (returned from
*note type.__prepare__(): e5a.) is now an insertion-order-preserving
mapping.

Vedi anche
..........

PEP 520(1) – Preserving Class Attribute Definition Order

     PEP written and implemented by Eric Snow.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0520/


File: python.info,  Node: PEP 468 Preserving Keyword Argument Order,  Next: New dict implementation,  Prev: PEP 520 Preserving Class Attribute Definition Order,  Up: New Features<11>

1.9.2.13 PEP 468: Preserving Keyword Argument Order
...................................................

‘**kwargs’ in a function signature is now guaranteed to be an
insertion-order-preserving mapping.

Vedi anche
..........

PEP 468(1) – Preserving Keyword Argument Order

     PEP written and implemented by Eric Snow.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0468/


File: python.info,  Node: New dict implementation,  Next: PEP 523 Adding a frame evaluation API to CPython,  Prev: PEP 468 Preserving Keyword Argument Order,  Up: New Features<11>

1.9.2.14 New dict implementation
................................

The *note dict: cbf. type now uses a «compact» representation based on a
proposal by Raymond Hettinger(1) which was first implemented by PyPy(2).
The memory usage of the new *note dict(): 183. is between 20% and 25%
smaller compared to Python 3.5.

The order-preserving aspect of this new implementation is considered an
implementation detail and should not be relied upon (this may change in
the future, but it is desired to have this new dict implementation in
the language for a few releases before changing the language spec to
mandate order-preserving semantics for all current and future Python
implementations; this also helps preserve backwards-compatibility with
older versions of the language where random iteration order is still in
effect, e.g.  Python 3.5).

(Contributed by INADA Naoki in bpo-27350(3).  Idea originally suggested
by Raymond Hettinger(4).)

   ---------- Footnotes ----------

   (1) 
https://mail.python.org/pipermail/python-dev/2012-December/123028.html

   (2) 
https://morepypy.blogspot.com/2015/01/faster-more-memory-efficient-and-more.html

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27350

   (4) 
https://mail.python.org/pipermail/python-dev/2012-December/123028.html


File: python.info,  Node: PEP 523 Adding a frame evaluation API to CPython,  Next: PYTHONMALLOC environment variable,  Prev: New dict implementation,  Up: New Features<11>

1.9.2.15 PEP 523: Adding a frame evaluation API to CPython
..........................................................

While Python provides extensive support to customize how code executes,
one place it has not done so is in the evaluation of frame objects.  If
you wanted some way to intercept frame evaluation in Python there really
wasn’t any way without directly manipulating function pointers for
defined functions.

PEP 523(1) changes this by providing an API to make frame evaluation
pluggable at the C level.  This will allow for tools such as debuggers
and JITs to intercept frame evaluation before the execution of Python
code begins.  This enables the use of alternative evaluation
implementations for Python code, tracking frame evaluation, etc.

This API is not part of the limited C API and is marked as private to
signal that usage of this API is expected to be limited and only
applicable to very select, low-level use-cases.  Semantics of the API
will change with Python as necessary.

Vedi anche
..........

PEP 523(2) – Adding a frame evaluation API to CPython

     PEP written by Brett Cannon and Dino Viehland.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0523/

   (2) https://peps.python.org/pep-0523/


File: python.info,  Node: PYTHONMALLOC environment variable,  Next: DTrace and SystemTap probing support,  Prev: PEP 523 Adding a frame evaluation API to CPython,  Up: New Features<11>

1.9.2.16 PYTHONMALLOC environment variable
..........................................

The new *note PYTHONMALLOC: e60. environment variable allows setting the
Python memory allocators and installing debug hooks.

It is now possible to install debug hooks on Python memory allocators on
Python compiled in release mode using ‘PYTHONMALLOC=debug’.  Effects of
debug hooks:

   * Newly allocated memory is filled with the byte ‘0xCB’

   * Freed memory is filled with the byte ‘0xDB’

   * Detect violations of the Python memory allocator API. For example,
     *note PyObject_Free(): e61. called on a memory block allocated by
     *note PyMem_Malloc(): e62.

   * Detect writes before the start of a buffer (buffer underflows)

   * Detect writes after the end of a buffer (buffer overflows)

   * Check that the *note GIL: 474. is held when allocator functions of
     *note PYMEM_DOMAIN_OBJ: e63. (ex: *note PyObject_Malloc(): e64.)
     and *note PYMEM_DOMAIN_MEM: e65. (ex: *note PyMem_Malloc(): e62.)
     domains are called.

Checking if the GIL is held is also a new feature of Python 3.6.

See the *note PyMem_SetupDebugHooks(): e66. function for debug hooks on
Python memory allocators.

It is now also possible to force the usage of the ‘malloc()’ allocator
of the C library for all Python memory allocations using
‘PYTHONMALLOC=malloc’.  This is helpful when using external memory
debuggers like Valgrind on a Python compiled in release mode.

On error, the debug hooks on Python memory allocators now use the *note
tracemalloc: 105. module to get the traceback where a memory block was
allocated.

Example of fatal error on buffer overflow using ‘python3.6 -X
tracemalloc=5’ (store 5 frames in traces):

     Debug memory block at address p=0x7fbcd41666f8: API 'o'
         4 bytes originally requested
         The 7 pad bytes at p-7 are FORBIDDENBYTE, as expected.
         The 8 pad bytes at tail=0x7fbcd41666fc are not all FORBIDDENBYTE (0xfb):
             at tail+0: 0x02 *** OUCH
             at tail+1: 0xfb
             at tail+2: 0xfb
             at tail+3: 0xfb
             at tail+4: 0xfb
             at tail+5: 0xfb
             at tail+6: 0xfb
             at tail+7: 0xfb
         The block was made by call #1233329 to debug malloc/realloc.
         Data at p: 1a 2b 30 00

     Memory block allocated at (most recent call first):
       File "test/test_bytes.py", line 323
       File "unittest/case.py", line 600
       File "unittest/case.py", line 648
       File "unittest/suite.py", line 122
       File "unittest/suite.py", line 84

     Fatal Python error: bad trailing pad byte

     Current thread 0x00007fbcdbd32700 (most recent call first):
       File "test/test_bytes.py", line 323 in test_hex
       File "unittest/case.py", line 600 in run
       File "unittest/case.py", line 648 in __call__
       File "unittest/suite.py", line 122 in run
       File "unittest/suite.py", line 84 in __call__
       File "unittest/suite.py", line 122 in run
       File "unittest/suite.py", line 84 in __call__
       ...

(Contributed by Victor Stinner in bpo-26516(1) and bpo-26564(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26516

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26564


File: python.info,  Node: DTrace and SystemTap probing support,  Prev: PYTHONMALLOC environment variable,  Up: New Features<11>

1.9.2.17 DTrace and SystemTap probing support
.............................................

Python can now be built ‘--with-dtrace’ which enables static markers for
the following events in the interpreter:

   * function call/return

   * garbage collection started/finished

   * line of code executed.

This can be used to instrument running interpreters in production,
without the need to recompile specific *note debug builds: 50a. or
providing application-specific profiling/debugging code.

More details in *note Instrumenting CPython with DTrace and SystemTap:
e68.

The current implementation is tested on Linux and macOS. Additional
markers may be added in the future.

(Contributed by Łukasz Langa in bpo-21590(1), based on patches by Jesús
Cea Avión, David Malcolm, and Nikhil Benesch.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21590


File: python.info,  Node: Other Language Changes<7>,  Next: New Modules<7>,  Prev: New Features<11>,  Up: What’s New In Python 3 6

1.9.3 Other Language Changes
----------------------------

Some smaller changes made to the core Python language are:

   * A ‘global’ or ‘nonlocal’ statement must now textually appear before
     the first use of the affected name in the same scope.  Previously
     this was a *note SyntaxWarning: 1ae.

   * It is now possible to set a *note special method: e6a. to ‘None’ to
     indicate that the corresponding operation is not available.  For
     example, if a class sets *note __iter__(): e6b. to ‘None’, the
     class is not iterable.  (Contributed by Andrew Barnert and Ivan
     Levkivskyi in bpo-25958(1).)

   * Long sequences of repeated traceback lines are now abbreviated as
     ‘"[Previous line repeated {count} more times]"’ (see *note
     traceback: e6c. for an example).  (Contributed by Emanuel Barry in
     bpo-26823(2).)

   * Import now raises the new exception *note ModuleNotFoundError: d3f.
     (subclass of *note ImportError: 65b.) when it cannot find a module.
     Code that currently checks for ImportError (in try-except) will
     still work.  (Contributed by Eric Snow in bpo-15767(3).)

   * Class methods relying on zero-argument ‘super()’ will now work
     correctly when called from metaclass methods during class creation.
     (Contributed by Martin Teichmann in bpo-23722(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25958

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26823

   (3) https://bugs.python.org/issue?@action=redirect&bpo=15767

   (4) https://bugs.python.org/issue?@action=redirect&bpo=23722


File: python.info,  Node: New Modules<7>,  Next: Improved Modules<7>,  Prev: Other Language Changes<7>,  Up: What’s New In Python 3 6

1.9.4 New Modules
-----------------

* Menu:

* secrets::


File: python.info,  Node: secrets,  Up: New Modules<7>

1.9.4.1 secrets
...............

The main purpose of the new *note secrets: c5. module is to provide an
obvious way to reliably generate cryptographically strong pseudo-random
values suitable for managing secrets, such as account authentication,
tokens, and similar.

     Avvertimento: Note that the pseudo-random generators in the *note
     random: bd. module should 'NOT' be used for security purposes.  Use
     *note secrets: c5. on Python 3.6+ and *note os.urandom(): 747. on
     Python 3.5 and earlier.

Vedi anche
..........

PEP 506(1) – Adding A Secrets Module To The Standard Library

     PEP written and implemented by Steven D’Aprano.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0506/


File: python.info,  Node: Improved Modules<7>,  Next: Optimizations<8>,  Prev: New Modules<7>,  Up: What’s New In Python 3 6

1.9.5 Improved Modules
----------------------

* Menu:

* array: array<4>.
* ast: ast<6>.
* asyncio: asyncio<12>.
* binascii: binascii<2>.
* cmath::
* collections: collections<4>.
* concurrent.futures: concurrent futures<5>.
* contextlib: contextlib<4>.
* datetime: datetime<6>.
* decimal: decimal<3>.
* distutils: distutils<5>.
* email: email<3>.
* encodings: encodings<2>.
* enum: enum<7>.
* faulthandler: faulthandler<3>.
* fileinput: fileinput<2>.
* hashlib: hashlib<5>.
* http.client: http client<2>.
* idlelib and IDLE: idlelib and IDLE<2>.
* importlib: importlib<6>.
* inspect: inspect<7>.
* json: json<2>.
* logging: logging<4>.
* math: math<7>.
* multiprocessing: multiprocessing<6>.
* os: os<9>.
* pathlib: pathlib<12>.
* pdb: pdb<7>.
* pickle: pickle<3>.
* pickletools::
* pydoc: pydoc<4>.
* random: random<4>.
* re: re<6>.
* readline::
* rlcompleter::
* shlex: shlex<2>.
* site: site<3>.
* sqlite3: sqlite3<8>.
* socket: socket<8>.
* socketserver: socketserver<2>.
* ssl: ssl<8>.
* statistics: statistics<4>.
* struct: struct<2>.
* subprocess: subprocess<3>.
* sys: sys<10>.
* telnetlib::
* time: time<6>.
* timeit::
* tkinter: tkinter<7>.
* traceback: traceback<4>.
* tracemalloc: tracemalloc<3>.
* typing: typing<10>.
* unicodedata: unicodedata<8>.
* unittest.mock: unittest mock<2>.
* urllib.request: urllib request.
* urllib.robotparser: urllib robotparser.
* venv: venv<5>.
* warnings: warnings<4>.
* winreg::
* winsound::
* xmlrpc.client: xmlrpc client.
* zipfile: zipfile<4>.
* zlib: zlib<2>.


File: python.info,  Node: array<4>,  Next: ast<6>,  Up: Improved Modules<7>

1.9.5.1 array
.............

Exhausted iterators of *note array.array: 4bf. will now stay exhausted
even if the iterated array is extended.  This is consistent with the
behavior of other mutable sequences.

Contributed by Serhiy Storchaka in bpo-26492(1).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26492


File: python.info,  Node: ast<6>,  Next: asyncio<12>,  Prev: array<4>,  Up: Improved Modules<7>

1.9.5.2 ast
...........

The new *note ast.Constant: 2ef. AST node has been added.  It can be
used by external AST optimizers for the purposes of constant folding.

Contributed by Victor Stinner in bpo-26146(1).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26146


File: python.info,  Node: asyncio<12>,  Next: binascii<2>,  Prev: ast<6>,  Up: Improved Modules<7>

1.9.5.3 asyncio
...............

Starting with Python 3.6 the ‘asyncio’ module is no longer provisional
and its API is considered stable.

Notable changes in the *note asyncio: b. module since Python 3.5.0 (all
backported to 3.5.x due to the provisional status):

   * The *note get_event_loop(): 2f2. function has been changed to
     always return the currently running loop when called from
     coroutines and callbacks.  (Contributed by Yury Selivanov in
     bpo-28613(1).)

   * The *note ensure_future(): e73. function and all functions that use
     it, such as *note loop.run_until_complete(): e74, now accept all
     kinds of *note awaitable objects: 4ca.  (Contributed by Yury
     Selivanov.)

   * New *note run_coroutine_threadsafe(): a84. function to submit
     coroutines to event loops from other threads.  (Contributed by
     Vincent Michel.)

   * New *note Transport.is_closing(): e75. method to check if the
     transport is closing or closed.  (Contributed by Yury Selivanov.)

   * The *note loop.create_server(): d0b. method can now accept a list
     of hosts.  (Contributed by Yann Sionneau.)

   * New *note loop.create_future(): e76. method to create Future
     objects.  This allows alternative event loop implementations, such
     as uvloop(2), to provide a faster *note asyncio.Future: dc8.
     implementation.  (Contributed by Yury Selivanov in bpo-27041(3).)

   * New *note loop.get_exception_handler(): e77. method to get the
     current exception handler.  (Contributed by Yury Selivanov in
     bpo-27040(4).)

   * New *note StreamReader.readuntil(): 4d1. method to read data from
     the stream until a separator bytes sequence appears.  (Contributed
     by Mark Korenberg.)

   * The performance of *note StreamReader.readexactly(): e78. has been
     improved.  (Contributed by Mark Korenberg in bpo-28370(5).)

   * The *note loop.getaddrinfo(): e10. method is optimized to avoid
     calling the system ‘getaddrinfo’ function if the address is already
     resolved.  (Contributed by A. Jesse Jiryu Davis.)

   * The *note loop.stop(): e79. method has been changed to stop the
     loop immediately after the current iteration.  Any new callbacks
     scheduled as a result of the last iteration will be discarded.
     (Contributed by Guido van Rossum in bpo-25593(6).)

   * *note Future.set_exception: e7a. will now raise *note TypeError:
     198. when passed an instance of the *note StopIteration: df7.
     exception.  (Contributed by Chris Angelico in bpo-26221(7).)

   * New *note loop.connect_accepted_socket(): 9e0. method to be used by
     servers that accept connections outside of asyncio, but that use
     asyncio to handle them.  (Contributed by Jim Fulton in
     bpo-27392(8).)

   * ‘TCP_NODELAY’ flag is now set for all TCP transports by default.
     (Contributed by Yury Selivanov in bpo-27456(9).)

   * New *note loop.shutdown_asyncgens(): e7b. to properly close pending
     asynchronous generators before closing the loop.  (Contributed by
     Yury Selivanov in bpo-28003(10).)

   * *note Future: dc8. and *note Task: 1c7. classes now have an
     optimized C implementation which makes asyncio code up to 30%
     faster.  (Contributed by Yury Selivanov and INADA Naoki in
     bpo-26081(11) and bpo-28544(12).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28613

   (2) https://github.com/MagicStack/uvloop

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27041

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27040

   (5) https://bugs.python.org/issue?@action=redirect&bpo=28370

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25593

   (7) https://bugs.python.org/issue?@action=redirect&bpo=26221

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27392

   (9) https://bugs.python.org/issue?@action=redirect&bpo=27456

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28003

   (11) https://bugs.python.org/issue?@action=redirect&bpo=26081

   (12) https://bugs.python.org/issue?@action=redirect&bpo=28544


File: python.info,  Node: binascii<2>,  Next: cmath,  Prev: asyncio<12>,  Up: Improved Modules<7>

1.9.5.4 binascii
................

The *note b2a_base64(): e7d. function now accepts an optional 'newline'
keyword argument to control whether the newline character is appended to
the return value.  (Contributed by Victor Stinner in bpo-25357(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25357


File: python.info,  Node: cmath,  Next: collections<4>,  Prev: binascii<2>,  Up: Improved Modules<7>

1.9.5.5 cmath
.............

The new *note cmath.tau: e7f. ('τ') constant has been added.
(Contributed by Lisa Roach in bpo-12345(1), see PEP 628(2) for details.)

New constants: *note cmath.inf: e80. and *note cmath.nan: e81. to match
*note math.inf: e82. and *note math.nan: 874, and also *note cmath.infj:
e83. and *note cmath.nanj: e84. to match the format used by complex
repr.  (Contributed by Mark Dickinson in bpo-23229(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12345

   (2) https://peps.python.org/pep-0628/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23229


File: python.info,  Node: collections<4>,  Next: concurrent futures<5>,  Prev: cmath,  Up: Improved Modules<7>

1.9.5.6 collections
...................

The new *note Collection: e86. abstract base class has been added to
represent sized iterable container classes.  (Contributed by Ivan
Levkivskyi, docs by Neil Girdhar in bpo-27598(1).)

The new *note Reversible: e87. abstract base class represents iterable
classes that also provide the *note __reversed__(): e88. method.
(Contributed by Ivan Levkivskyi in bpo-25987(2).)

The new *note AsyncGenerator: e89. abstract base class represents
asynchronous generators.  (Contributed by Yury Selivanov in
bpo-28720(3).)

The *note namedtuple(): 4e1. function now accepts an optional keyword
argument 'module', which, when specified, is used for the *note
__module__: 617. attribute of the returned named tuple class.
(Contributed by Raymond Hettinger in bpo-17941(4).)

The 'verbose' and 'rename' arguments for *note namedtuple(): 4e1. are
now keyword-only.  (Contributed by Raymond Hettinger in bpo-25628(5).)

Recursive *note collections.deque: 7f5. instances can now be pickled.
(Contributed by Serhiy Storchaka in bpo-26482(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27598

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25987

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28720

   (4) https://bugs.python.org/issue?@action=redirect&bpo=17941

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25628

   (6) https://bugs.python.org/issue?@action=redirect&bpo=26482


File: python.info,  Node: concurrent futures<5>,  Next: contextlib<4>,  Prev: collections<4>,  Up: Improved Modules<7>

1.9.5.7 concurrent.futures
..........................

The *note ThreadPoolExecutor: 94a. class constructor now accepts an
optional 'thread_name_prefix' argument to make it possible to customize
the names of the threads created by the pool.  (Contributed by Gregory
P.  Smith in bpo-27664(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27664


File: python.info,  Node: contextlib<4>,  Next: datetime<6>,  Prev: concurrent futures<5>,  Up: Improved Modules<7>

1.9.5.8 contextlib
..................

The *note contextlib.AbstractContextManager: e8c. class has been added
to provide an abstract base class for context managers.  It provides a
sensible default implementation for ‘__enter__()’ which returns ‘self’
and leaves ‘__exit__()’ an abstract method.  A matching class has been
added to the *note typing: 10a. module as *note typing.ContextManager:
e8d.  (Contributed by Brett Cannon in bpo-25609(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25609


File: python.info,  Node: datetime<6>,  Next: decimal<3>,  Prev: contextlib<4>,  Up: Improved Modules<7>

1.9.5.9 datetime
................

The *note datetime: 4e3. and *note time: 1fb. classes have the new *note
fold: e8f. attribute used to disambiguate local time when necessary.
Many functions in the *note datetime: 34. have been updated to support
local time disambiguation.  See *note Local Time Disambiguation: e38.
section for more information.  (Contributed by Alexander Belopolsky in
bpo-24773(1).)

The *note datetime.strftime(): e90. and *note date.strftime(): e91.
methods now support ISO 8601 date directives ‘%G’, ‘%u’ and ‘%V’.
(Contributed by Ashley Anderson in bpo-12006(2).)

The *note datetime.isoformat(): d27. function now accepts an optional
'timespec' argument that specifies the number of additional components
of the time value to include.  (Contributed by Alessandro Cucci and
Alexander Belopolsky in bpo-19475(3).)

The *note datetime.combine(): e92. now accepts an optional 'tzinfo'
argument.  (Contributed by Alexander Belopolsky in bpo-27661(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24773

   (2) https://bugs.python.org/issue?@action=redirect&bpo=12006

   (3) https://bugs.python.org/issue?@action=redirect&bpo=19475

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27661


File: python.info,  Node: decimal<3>,  Next: distutils<5>,  Prev: datetime<6>,  Up: Improved Modules<7>

1.9.5.10 decimal
................

New *note Decimal.as_integer_ratio(): e94. method that returns a pair
‘(n, d)’ of integers that represent the given *note Decimal: 1fe.
instance as a fraction, in lowest terms and with a positive denominator:

     >>> Decimal('-3.14').as_integer_ratio()
     (-157, 50)

(Contributed by Stefan Krah amd Mark Dickinson in bpo-25928(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25928


File: python.info,  Node: distutils<5>,  Next: email<3>,  Prev: decimal<3>,  Up: Improved Modules<7>

1.9.5.11 distutils
..................

The ‘default_format’ attribute has been removed from
‘distutils.command.sdist.sdist’ and the ‘formats’ attribute defaults to
‘['gztar']’.  Although not anticipated, any code relying on the presence
of ‘default_format’ may need to be adapted.  See bpo-27819(1) for more
details.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27819


File: python.info,  Node: email<3>,  Next: encodings<2>,  Prev: distutils<5>,  Up: Improved Modules<7>

1.9.5.12 email
..............

The new email API, enabled via the 'policy' keyword to various
constructors, is no longer provisional.  The *note email: 3f.
documentation has been reorganized and rewritten to focus on the new
API, while retaining the old documentation for the legacy API.
(Contributed by R. David Murray in bpo-24277(1).)

The *note email.mime: 49. classes now all accept an optional 'policy'
keyword.  (Contributed by Berker Peksag in bpo-27331(2).)

The *note DecodedGenerator: e97. now supports the 'policy' keyword.

There is a new *note policy: 53. attribute, *note message_factory: e98,
that controls what class is used by default when the parser creates new
message objects.  For the *note email.policy.compat32: e99. policy this
is *note Message: 581, for the new policies it is *note EmailMessage:
580.  (Contributed by R. David Murray in bpo-20476(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24277

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27331

   (3) https://bugs.python.org/issue?@action=redirect&bpo=20476


File: python.info,  Node: encodings<2>,  Next: enum<7>,  Prev: email<3>,  Up: Improved Modules<7>

1.9.5.13 encodings
..................

On Windows, added the ‘'oem'’ encoding to use ‘CP_OEMCP’, and the
‘'ansi'’ alias for the existing ‘'mbcs'’ encoding, which uses the
‘CP_ACP’ code page.  (Contributed by Steve Dower in bpo-27959(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27959


File: python.info,  Node: enum<7>,  Next: faulthandler<3>,  Prev: encodings<2>,  Up: Improved Modules<7>

1.9.5.14 enum
.............

Two new enumeration base classes have been added to the *note enum: 5a.
module: *note Flag: 836. and *note IntFlag: e9c.  Both are used to
define constants that can be combined using the bitwise operators.
(Contributed by Ethan Furman in bpo-23591(1).)

Many standard library modules have been updated to use the *note
IntFlag: e9c. class for their constants.

The new *note enum.auto: e9d. value can be used to assign values to enum
members automatically:

     >>> from enum import Enum, auto
     >>> class Color(Enum):
     ...     red = auto()
     ...     blue = auto()
     ...     green = auto()
     ...
     >>> list(Color)
     [<Color.red: 1>, <Color.blue: 2>, <Color.green: 3>]

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23591


File: python.info,  Node: faulthandler<3>,  Next: fileinput<2>,  Prev: enum<7>,  Up: Improved Modules<7>

1.9.5.15 faulthandler
.....................

On Windows, the *note faulthandler: 5c. module now installs a handler
for Windows exceptions: see *note faulthandler.enable(): 20f.
(Contributed by Victor Stinner in bpo-23848(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23848


File: python.info,  Node: fileinput<2>,  Next: hashlib<5>,  Prev: faulthandler<3>,  Up: Improved Modules<7>

1.9.5.16 fileinput
..................

*note hook_encoded(): ea0. now supports the 'errors' argument.
(Contributed by Joseph Hackman in bpo-25788(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25788


File: python.info,  Node: hashlib<5>,  Next: http client<2>,  Prev: fileinput<2>,  Up: Improved Modules<7>

1.9.5.17 hashlib
................

*note hashlib: 6c. supports OpenSSL 1.1.0.  The minimum recommend
version is 1.0.2.  (Contributed by Christian Heimes in bpo-26470(1).)

BLAKE2 hash functions were added to the module.  *note blake2b(): 853.
and *note blake2s(): 854. are always available and support the full
feature set of BLAKE2.  (Contributed by Christian Heimes in bpo-26798(2)
based on code by Dmitry Chestnykh and Samuel Neves.  Documentation
written by Dmitry Chestnykh.)

The SHA-3 hash functions *note sha3_224(): ea2, *note sha3_256(): ea3,
*note sha3_384(): ea4, *note sha3_512(): ea5, and SHAKE hash functions
*note shake_128(): ea6. and *note shake_256(): ea7. were added.
(Contributed by Christian Heimes in bpo-16113(3).  Keccak Code Package
by Guido Bertoni, Joan Daemen, Michaël Peeters, Gilles Van Assche, and
Ronny Van Keer.)

The password-based key derivation function *note scrypt(): e3a. is now
available with OpenSSL 1.1.0 and newer.  (Contributed by Christian
Heimes in bpo-27928(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26470

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26798

   (3) https://bugs.python.org/issue?@action=redirect&bpo=16113

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27928


File: python.info,  Node: http client<2>,  Next: idlelib and IDLE<2>,  Prev: hashlib<5>,  Up: Improved Modules<7>

1.9.5.18 http.client
....................

*note HTTPConnection.request(): ea9. and *note endheaders(): eaa. both
now support chunked encoding request bodies.  (Contributed by Demian
Brecht and Rolf Krahl in bpo-12319(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12319


File: python.info,  Node: idlelib and IDLE<2>,  Next: importlib<6>,  Prev: http client<2>,  Up: Improved Modules<7>

1.9.5.19 idlelib and IDLE
.........................

The idlelib package is being modernized and refactored to make IDLE look
and work better and to make the code easier to understand, test, and
improve.  Part of making IDLE look better, especially on Linux and Mac,
is using ttk widgets, mostly in the dialogs.  As a result, IDLE no
longer runs with tcl/tk 8.4.  It now requires tcl/tk 8.5 or 8.6.  We
recommend running the latest release of either.

“Modernizing” includes renaming and consolidation of idlelib modules.
The renaming of files with partial uppercase names is similar to the
renaming of, for instance, Tkinter and TkFont to tkinter and
tkinter.font in 3.0.  As a result, imports of idlelib files that worked
in 3.5 will usually not work in 3.6.  At least a module name change will
be needed (see idlelib/README.txt), sometimes more.  (Name changes
contributed by Al Swiegart and Terry Reedy in bpo-24225(1).  Most
idlelib patches since have been and will be part of the process.)

In compensation, the eventual result with be that some idlelib classes
will be easier to use, with better APIs and docstrings explaining them.
Additional useful information will be added to idlelib when available.

New in 3.6.2:

Multiple fixes for autocompletion.  (Contributed by Louie Lu in
bpo-15786(2).)

New in 3.6.3:

Module Browser (on the File menu, formerly called Class Browser), now
displays nested functions and classes in addition to top-level functions
and classes.  (Contributed by Guilherme Polo, Cheryl Sabella, and Terry
Jan Reedy in bpo-1612262(3).)

The IDLE features formerly implemented as extensions have been
reimplemented as normal features.  Their settings have been moved from
the Extensions tab to other dialog tabs.  (Contributed by Charles
Wohlganger and Terry Jan Reedy in bpo-27099(4).)

The Settings dialog (Options, Configure IDLE) has been partly rewritten
to improve both appearance and function.  (Contributed by Cheryl Sabella
and Terry Jan Reedy in multiple issues.)

New in 3.6.4:

The font sample now includes a selection of non-Latin characters so that
users can better see the effect of selecting a particular font.
(Contributed by Terry Jan Reedy in bpo-13802(5).)  The sample can be
edited to include other characters.  (Contributed by Serhiy Storchaka in
bpo-31860(6).)

New in 3.6.6:

Editor code context option revised.  Box displays all context lines up
to maxlines.  Clicking on a context line jumps the editor to that line.
Context colors for custom themes is added to Highlights tab of Settings
dialog.  (Contributed by Cheryl Sabella and Terry Jan Reedy in
bpo-33642(7), bpo-33768(8), and bpo-33679(9).)

On Windows, a new API call tells Windows that tk scales for DPI. On
Windows 8.1+ or 10, with DPI compatibility properties of the Python
binary unchanged, and a monitor resolution greater than 96 DPI, this
should make text and lines sharper.  It should otherwise have no effect.
(Contributed by Terry Jan Reedy in bpo-33656(10).)

New in 3.6.7:

Output over N lines (50 by default) is squeezed down to a button.  N can
be changed in the PyShell section of the General page of the Settings
dialog.  Fewer, but possibly extra long, lines can be squeezed by right
clicking on the output.  Squeezed output can be expanded in place by
double-clicking the button or into the clipboard or a separate window by
right-clicking the button.  (Contributed by Tal Einat in
bpo-1529353(11).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24225

   (2) https://bugs.python.org/issue?@action=redirect&bpo=15786

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1612262

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27099

   (5) https://bugs.python.org/issue?@action=redirect&bpo=13802

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31860

   (7) https://bugs.python.org/issue?@action=redirect&bpo=33642

   (8) https://bugs.python.org/issue?@action=redirect&bpo=33768

   (9) https://bugs.python.org/issue?@action=redirect&bpo=33679

   (10) https://bugs.python.org/issue?@action=redirect&bpo=33656

   (11) https://bugs.python.org/issue?@action=redirect&bpo=1529353


File: python.info,  Node: importlib<6>,  Next: inspect<7>,  Prev: idlelib and IDLE<2>,  Up: Improved Modules<7>

1.9.5.20 importlib
..................

Import now raises the new exception *note ModuleNotFoundError: d3f.
(subclass of *note ImportError: 65b.) when it cannot find a module.
Code that current checks for ‘ImportError’ (in try-except) will still
work.  (Contributed by Eric Snow in bpo-15767(1).)

*note importlib.util.LazyLoader: ead. now calls *note create_module():
eae. on the wrapped loader, removing the restriction that *note
importlib.machinery.BuiltinImporter: eaf. and *note
importlib.machinery.ExtensionFileLoader: eb0. couldn’t be used with
*note importlib.util.LazyLoader: ead.

*note importlib.util.cache_from_source(): 353, *note
importlib.util.source_from_cache(): 73f, and *note
importlib.util.spec_from_file_location(): eb1. now accept a *note
path-like object: 5a1.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15767


File: python.info,  Node: inspect<7>,  Next: json<2>,  Prev: importlib<6>,  Up: Improved Modules<7>

1.9.5.21 inspect
................

The *note inspect.signature(): 22f. function now reports the implicit
‘.0’ parameters generated by the compiler for comprehension and
generator expression scopes as if they were positional-only parameters
called ‘implicit0’.  (Contributed by Jelle Zijlstra in bpo-19611(1).)

To reduce code churn when upgrading from Python 2.7 and the legacy
‘inspect.getargspec()’ API, the previously documented deprecation of
*note inspect.getfullargspec(): 942. has been reversed.  While this
function is convenient for single/source Python 2/3 code bases, the
richer *note inspect.signature(): 22f. interface remains the recommended
approach for new code.  (Contributed by Nick Coghlan in bpo-27172(2))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19611

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27172


File: python.info,  Node: json<2>,  Next: logging<4>,  Prev: inspect<7>,  Up: Improved Modules<7>

1.9.5.22 json
.............

*note json.load(): eb4. and *note json.loads(): b50. now support binary
input.  Encoded JSON should be represented using either UTF-8, UTF-16,
or UTF-32.  (Contributed by Serhiy Storchaka in bpo-17909(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17909


File: python.info,  Node: logging<4>,  Next: math<7>,  Prev: json<2>,  Up: Improved Modules<7>

1.9.5.23 logging
................

The new *note WatchedFileHandler.reopenIfNeeded(): eb6. method has been
added to add the ability to check if the log file needs to be reopened.
(Contributed by Marian Horban in bpo-24884(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24884


File: python.info,  Node: math<7>,  Next: multiprocessing<6>,  Prev: logging<4>,  Up: Improved Modules<7>

1.9.5.24 math
.............

The tau ('τ') constant has been added to the *note math: 92. and *note
cmath: 19. modules.  (Contributed by Lisa Roach in bpo-12345(1), see PEP
628(2) for details.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12345

   (2) https://peps.python.org/pep-0628/


File: python.info,  Node: multiprocessing<6>,  Next: os<9>,  Prev: math<7>,  Up: Improved Modules<7>

1.9.5.25 multiprocessing
........................

*note Proxy Objects: 24c. returned by *note multiprocessing.Manager():
250. can now be nested.  (Contributed by Davin Potts in bpo-6766(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6766


File: python.info,  Node: os<9>,  Next: pathlib<12>,  Prev: multiprocessing<6>,  Up: Improved Modules<7>

1.9.5.26 os
...........

See the summary of *note PEP 519: e37. for details on how the *note os:
a5. and *note os.path: a6. modules now support *note path-like objects:
5a1.

*note scandir(): c56. now supports *note bytes: 192. paths on Windows.

A new *note close(): eba. method allows explicitly closing a *note
scandir(): c56. iterator.  The *note scandir(): c56. iterator now
supports the *note context manager: 1e1. protocol.  If a ‘scandir()’
iterator is neither exhausted nor explicitly closed a *note
ResourceWarning: 54d. will be emitted in its destructor.  (Contributed
by Serhiy Storchaka in bpo-25994(1).)

On Linux, *note os.urandom(): 747. now blocks until the system urandom
entropy pool is initialized to increase the security.  See the PEP
524(2) for the rationale.

The Linux ‘getrandom()’ syscall (get random bytes) is now exposed as the
new *note os.getrandom(): ebb. function.  (Contributed by Victor
Stinner, part of the PEP 524(3))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25994

   (2) https://peps.python.org/pep-0524/

   (3) https://peps.python.org/pep-0524/


File: python.info,  Node: pathlib<12>,  Next: pdb<7>,  Prev: os<9>,  Up: Improved Modules<7>

1.9.5.27 pathlib
................

*note pathlib: a8. now supports *note path-like objects: 5a1.
(Contributed by Brett Cannon in bpo-27186(1).)

See the summary of *note PEP 519: e37. for details.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27186


File: python.info,  Node: pdb<7>,  Next: pickle<3>,  Prev: pathlib<12>,  Up: Improved Modules<7>

1.9.5.28 pdb
............

The *note Pdb: 273. class constructor has a new optional 'readrc'
argument to control whether ‘.pdbrc’ files should be read.


File: python.info,  Node: pickle<3>,  Next: pickletools,  Prev: pdb<7>,  Up: Improved Modules<7>

1.9.5.29 pickle
...............

Objects that need ‘__new__’ called with keyword arguments can now be
pickled using *note pickle protocols: 27b. older than protocol version
4.  Protocol version 4 already supports this case.  (Contributed by
Serhiy Storchaka in bpo-24164(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24164


File: python.info,  Node: pickletools,  Next: pydoc<4>,  Prev: pickle<3>,  Up: Improved Modules<7>

1.9.5.30 pickletools
....................

*note pickletools.dis(): ec0. now outputs the implicit memo index for
the ‘MEMOIZE’ opcode.  (Contributed by Serhiy Storchaka in
bpo-25382(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25382


File: python.info,  Node: pydoc<4>,  Next: random<4>,  Prev: pickletools,  Up: Improved Modules<7>

1.9.5.31 pydoc
..............

The *note pydoc: ba. module has learned to respect the ‘MANPAGER’
environment variable.  (Contributed by Matthias Klose in bpo-8637(1).)

*note help(): ad6. and *note pydoc: ba. can now list named tuple fields
in the order they were defined rather than alphabetically.  (Contributed
by Raymond Hettinger in bpo-24879(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8637

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24879


File: python.info,  Node: random<4>,  Next: re<6>,  Prev: pydoc<4>,  Up: Improved Modules<7>

1.9.5.32 random
...............

The new *note choices(): ec3. function returns a list of elements of
specified size from the given population with optional weights.
(Contributed by Raymond Hettinger in bpo-18844(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18844


File: python.info,  Node: re<6>,  Next: readline,  Prev: random<4>,  Up: Improved Modules<7>

1.9.5.33 re
...........

Added support of modifier spans in regular expressions.  Examples:
‘'(?i:p)ython'’ matches ‘'python'’ and ‘'Python'’, but not ‘'PYTHON'’;
‘'(?i)g(?-i:v)r'’ matches ‘'GvR'’ and ‘'gvr'’, but not ‘'GVR'’.
(Contributed by Serhiy Storchaka in bpo-433028(1).)

Match object groups can be accessed by ‘__getitem__’, which is
equivalent to ‘group()’.  So ‘mo['name']’ is now equivalent to
‘mo.group('name')’.  (Contributed by Eric Smith in bpo-24454(2).)

*note Match: ec5. objects now support *note index-like objects: 19e. as
group indices.  (Contributed by Jeroen Demeyer and Xiang Zhang in
bpo-27177(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=433028

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24454

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27177


File: python.info,  Node: readline,  Next: rlcompleter,  Prev: re<6>,  Up: Improved Modules<7>

1.9.5.34 readline
.................

Added *note set_auto_history(): ec7. to enable or disable automatic
addition of input to the history list.  (Contributed by Tyler Crompton
in bpo-26870(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26870


File: python.info,  Node: rlcompleter,  Next: shlex<2>,  Prev: readline,  Up: Improved Modules<7>

1.9.5.35 rlcompleter
....................

Private and special attribute names now are omitted unless the prefix
starts with underscores.  A space or a colon is added after some
completed keywords.  (Contributed by Serhiy Storchaka in bpo-25011(1)
and bpo-25209(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25011

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25209


File: python.info,  Node: shlex<2>,  Next: site<3>,  Prev: rlcompleter,  Up: Improved Modules<7>

1.9.5.36 shlex
..............

The *note shlex: eca. has much *note improved shell compatibility: ecb.
through the new 'punctuation_chars' argument to control which characters
are treated as punctuation.  (Contributed by Vinay Sajip in
bpo-1521950(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1521950


File: python.info,  Node: site<3>,  Next: sqlite3<8>,  Prev: shlex<2>,  Up: Improved Modules<7>

1.9.5.37 site
.............

When specifying paths to add to *note sys.path: 3e4. in a ‘.pth’ file,
you may now specify file paths on top of directories (e.g.  zip files).
(Contributed by Wolfgang Langner in bpo-26587(1)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26587


File: python.info,  Node: sqlite3<8>,  Next: socket<8>,  Prev: site<3>,  Up: Improved Modules<7>

1.9.5.38 sqlite3
................

*note sqlite3.Cursor.lastrowid: ece. now supports the ‘REPLACE’
statement.  (Contributed by Alex LordThorsen in bpo-16864(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16864


File: python.info,  Node: socket<8>,  Next: socketserver<2>,  Prev: sqlite3<8>,  Up: Improved Modules<7>

1.9.5.39 socket
...............

The *note ioctl(): ed0. function now supports the *note
SIO_LOOPBACK_FAST_PATH: ed1. control code.  (Contributed by Daniel
Stokes in bpo-26536(1).)

The *note getsockopt(): ed2. constants ‘SO_DOMAIN’, ‘SO_PROTOCOL’,
‘SO_PEERSEC’, and ‘SO_PASSSEC’ are now supported.  (Contributed by
Christian Heimes in bpo-26907(2).)

The *note setsockopt(): ed3. now supports the ‘setsockopt(level,
optname, None, optlen: int)’ form.  (Contributed by Christian Heimes in
bpo-27744(3).)

The socket module now supports the address family *note AF_ALG: ed4. to
interface with Linux Kernel crypto API. ‘ALG_*’, ‘SOL_ALG’ and *note
sendmsg_afalg(): ed5. were added.  (Contributed by Christian Heimes in
bpo-27744(4) with support from Victor Stinner.)

New Linux constants ‘TCP_USER_TIMEOUT’ and ‘TCP_CONGESTION’ were added.
(Contributed by Omar Sandoval, bpo-26273(5)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26536

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26907

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27744

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27744

   (5) https://bugs.python.org/issue?@action=redirect&bpo=26273


File: python.info,  Node: socketserver<2>,  Next: ssl<8>,  Prev: socket<8>,  Up: Improved Modules<7>

1.9.5.40 socketserver
.....................

Servers based on the *note socketserver: d2. module, including those
defined in *note http.server: 76, *note xmlrpc.server: 135. and *note
wsgiref.simple_server: 121, now support the *note context manager: 1e1.
protocol.  (Contributed by Aviv Palivoda in bpo-26404(1).)

The *note wfile: ed7. attribute of *note StreamRequestHandler: ed8.
classes now implements the *note io.BufferedIOBase: 8a4. writable
interface.  In particular, calling *note write(): ed9. is now guaranteed
to send the data in full.  (Contributed by Martin Panter in
bpo-26721(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26404

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26721


File: python.info,  Node: ssl<8>,  Next: statistics<4>,  Prev: socketserver<2>,  Up: Improved Modules<7>

1.9.5.41 ssl
............

*note ssl: d5. supports OpenSSL 1.1.0.  The minimum recommend version is
1.0.2.  (Contributed by Christian Heimes in bpo-26470(1).)

3DES has been removed from the default cipher suites and ChaCha20
Poly1305 cipher suites have been added.  (Contributed by Christian
Heimes in bpo-27850(2) and bpo-27766(3).)

*note SSLContext: 357. has better default configuration for options and
ciphers.  (Contributed by Christian Heimes in bpo-28043(4).)

SSL session can be copied from one client-side connection to another
with the new *note SSLSession: edb. class.  TLS session resumption can
speed up the initial handshake, reduce latency and improve performance
(Contributed by Christian Heimes in bpo-19500(5) based on a draft by
Alex Warhawk.)

The new *note get_ciphers(): edc. method can be used to get a list of
enabled ciphers in order of cipher priority.

All constants and flags have been converted to *note IntEnum: edd. and
*note IntFlag: e9c.  (Contributed by Christian Heimes in bpo-28025(6).)

Server and client-side specific TLS protocols for *note SSLContext: 357.
were added.  (Contributed by Christian Heimes in bpo-28085(7).)

Added *note ssl.SSLContext.post_handshake_auth: c28. to enable and *note
ssl.SSLSocket.verify_client_post_handshake(): c29. to initiate TLS 1.3
post-handshake authentication.  (Contributed by Christian Heimes in
gh-78851(8).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26470

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27850

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27766

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28043

   (5) https://bugs.python.org/issue?@action=redirect&bpo=19500

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28025

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28085

   (8) https://github.com/python/cpython/issues/78851


File: python.info,  Node: statistics<4>,  Next: struct<2>,  Prev: ssl<8>,  Up: Improved Modules<7>

1.9.5.42 statistics
...................

A new *note harmonic_mean(): edf. function has been added.  (Contributed
by Steven D’Aprano in bpo-27181(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27181


File: python.info,  Node: struct<2>,  Next: subprocess<3>,  Prev: statistics<4>,  Up: Improved Modules<7>

1.9.5.43 struct
...............

*note struct: db. now supports IEEE 754 half-precision floats via the
‘'e'’ format specifier.  (Contributed by Eli Stevens, Mark Dickinson in
bpo-11734(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11734


File: python.info,  Node: subprocess<3>,  Next: sys<10>,  Prev: struct<2>,  Up: Improved Modules<7>

1.9.5.44 subprocess
...................

*note subprocess.Popen: 4b8. destructor now emits a *note
ResourceWarning: 54d. warning if the child process is still running.
Use the context manager protocol (‘with proc: ...’) or explicitly call
the *note wait(): ee2. method to read the exit status of the child
process.  (Contributed by Victor Stinner in bpo-26741(1).)

The *note subprocess.Popen: 4b8. constructor and all functions that pass
arguments through to it now accept 'encoding' and 'errors' arguments.
Specifying either of these will enable text mode for the 'stdin',
'stdout' and 'stderr' streams.  (Contributed by Steve Dower in
bpo-6135(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26741

   (2) https://bugs.python.org/issue?@action=redirect&bpo=6135


File: python.info,  Node: sys<10>,  Next: telnetlib,  Prev: subprocess<3>,  Up: Improved Modules<7>

1.9.5.45 sys
............

The new *note getfilesystemencodeerrors(): ee4. function returns the
name of the error mode used to convert between Unicode filenames and
bytes filenames.  (Contributed by Steve Dower in bpo-27781(1).)

On Windows the return value of the *note getwindowsversion(): ee5.
function now includes the 'platform_version' field which contains the
accurate major version, minor version and build number of the current
operating system, rather than the version that is being emulated for the
process (Contributed by Steve Dower in bpo-27932(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27781

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27932


File: python.info,  Node: telnetlib,  Next: time<6>,  Prev: sys<10>,  Up: Improved Modules<7>

1.9.5.46 telnetlib
..................

‘telnetlib.Telnet’ is now a context manager (contributed by Stéphane
Wirtel in bpo-25485(1)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25485


File: python.info,  Node: time<6>,  Next: timeit,  Prev: telnetlib,  Up: Improved Modules<7>

1.9.5.47 time
.............

The *note struct_time: ee8. attributes ‘tm_gmtoff’ and ‘tm_zone’ are now
available on all platforms.


File: python.info,  Node: timeit,  Next: tkinter<7>,  Prev: time<6>,  Up: Improved Modules<7>

1.9.5.48 timeit
...............

The new *note Timer.autorange(): eea. convenience method has been added
to call *note Timer.timeit(): eeb. repeatedly so that the total run time
is greater or equal to 200 milliseconds.  (Contributed by Steven
D’Aprano in bpo-6422(1).)

*note timeit: f5. now warns when there is substantial (4x) variance
between best and worst times.  (Contributed by Serhiy Storchaka in
bpo-23552(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6422

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23552


File: python.info,  Node: tkinter<7>,  Next: traceback<4>,  Prev: timeit,  Up: Improved Modules<7>

1.9.5.49 tkinter
................

Added methods ‘Variable.trace_add()’, ‘Variable.trace_remove()’ and
‘trace_info()’ in the ‘tkinter.Variable’ class.  They replace old
methods ‘trace_variable()’, ‘trace()’, ‘trace_vdelete()’ and
‘trace_vinfo()’ that use obsolete Tcl commands and might not work in
future versions of Tcl.  (Contributed by Serhiy Storchaka in
bpo-22115(1)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22115


File: python.info,  Node: traceback<4>,  Next: tracemalloc<3>,  Prev: tkinter<7>,  Up: Improved Modules<7>

1.9.5.50 traceback
..................

Both the traceback module and the interpreter’s builtin exception
display now abbreviate long sequences of repeated lines in tracebacks as
shown in the following example:

     >>> def f(): f()
     ...
     >>> f()
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
       File "<stdin>", line 1, in f
       File "<stdin>", line 1, in f
       File "<stdin>", line 1, in f
       [Previous line repeated 995 more times]
     RecursionError: maximum recursion depth exceeded

(Contributed by Emanuel Barry in bpo-26823(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26823


File: python.info,  Node: tracemalloc<3>,  Next: typing<10>,  Prev: traceback<4>,  Up: Improved Modules<7>

1.9.5.51 tracemalloc
....................

The *note tracemalloc: 105. module now supports tracing memory
allocations in multiple different address spaces.

The new *note DomainFilter: eef. filter class has been added to filter
block traces by their address space (domain).

(Contributed by Victor Stinner in bpo-26588(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26588


File: python.info,  Node: typing<10>,  Next: unicodedata<8>,  Prev: tracemalloc<3>,  Up: Improved Modules<7>

1.9.5.52 typing
...............

Since the *note typing: 10a. module is *note provisional: 3d1, all
changes introduced in Python 3.6 have also been backported to Python
3.5.x.

The *note typing: 10a. module has a much improved support for generic
type aliases.  For example ‘Dict[str, Tuple[S, T]]’ is now a valid type
annotation.  (Contributed by Guido van Rossum in Github #195(1).)

The *note typing.ContextManager: e8d. class has been added for
representing *note contextlib.AbstractContextManager: e8c.  (Contributed
by Brett Cannon in bpo-25609(2).)

The *note typing.Collection: ef1. class has been added for representing
*note collections.abc.Collection: e86.  (Contributed by Ivan Levkivskyi
in bpo-27598(3).)

The *note typing.ClassVar: 56d. type construct has been added to mark
class variables.  As introduced in PEP 526(4), a variable annotation
wrapped in ClassVar indicates that a given attribute is intended to be
used as a class variable and should not be set on instances of that
class.  (Contributed by Ivan Levkivskyi in Github #280(5).)

A new *note TYPE_CHECKING: ef2. constant that is assumed to be ‘True’ by
the static type checkers, but is ‘False’ at runtime.  (Contributed by
Guido van Rossum in Github #230(6).)

A new *note NewType(): ef3. helper function has been added to create
lightweight distinct types for annotations:

     from typing import NewType

     UserId = NewType('UserId', int)
     some_id = UserId(524313)

The static type checker will treat the new type as if it were a subclass
of the original type.  (Contributed by Ivan Levkivskyi in Github
#189(7).)

   ---------- Footnotes ----------

   (1) https://github.com/python/typing/pull/195

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25609

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27598

   (4) https://peps.python.org/pep-0526/

   (5) https://github.com/python/typing/pull/280

   (6) https://github.com/python/typing/issues/230

   (7) https://github.com/python/typing/issues/189


File: python.info,  Node: unicodedata<8>,  Next: unittest mock<2>,  Prev: typing<10>,  Up: Improved Modules<7>

1.9.5.53 unicodedata
....................

The *note unicodedata: 10b. module now uses data from Unicode 9.0.0(1).
(Contributed by Benjamin Peterson.)

   ---------- Footnotes ----------

   (1) https://unicode.org/versions/Unicode9.0.0/


File: python.info,  Node: unittest mock<2>,  Next: urllib request,  Prev: unicodedata<8>,  Up: Improved Modules<7>

1.9.5.54 unittest.mock
......................

The *note Mock: c41. class has the following improvements:

   * Two new methods, *note Mock.assert_called(): ef6. and *note
     Mock.assert_called_once(): ef7. to check if the mock object was
     called.  (Contributed by Amit Saha in bpo-26323(1).)

   * The *note Mock.reset_mock(): ef8. method now has two optional
     keyword only arguments: 'return_value' and 'side_effect'.
     (Contributed by Kushal Das in bpo-21271(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26323

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21271


File: python.info,  Node: urllib request,  Next: urllib robotparser,  Prev: unittest mock<2>,  Up: Improved Modules<7>

1.9.5.55 urllib.request
.......................

If a HTTP request has a file or iterable body (other than a bytes
object) but no ‘Content-Length’ header, rather than throwing an error,
*note AbstractHTTPHandler: efa. now falls back to use chunked transfer
encoding.  (Contributed by Demian Brecht and Rolf Krahl in
bpo-12319(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12319


File: python.info,  Node: urllib robotparser,  Next: venv<5>,  Prev: urllib request,  Up: Improved Modules<7>

1.9.5.56 urllib.robotparser
...........................

*note RobotFileParser: efc. now supports the ‘Crawl-delay’ and
‘Request-rate’ extensions.  (Contributed by Nikolay Bogoychev in
bpo-16099(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16099


File: python.info,  Node: venv<5>,  Next: warnings<4>,  Prev: urllib robotparser,  Up: Improved Modules<7>

1.9.5.57 venv
.............

*note venv: 117. accepts a new parameter ‘--prompt’.  This parameter
provides an alternative prefix for the virtual environment.  (Proposed
by Łukasz Balcerzak and ported to 3.6 by Stéphane Wirtel in
bpo-22829(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22829


File: python.info,  Node: warnings<4>,  Next: winreg,  Prev: venv<5>,  Up: Improved Modules<7>

1.9.5.58 warnings
.................

A new optional 'source' parameter has been added to the *note
warnings.warn_explicit(): eff. function: the destroyed object which
emitted a *note ResourceWarning: 54d.  A 'source' attribute has also
been added to ‘warnings.WarningMessage’ (contributed by Victor Stinner
in bpo-26568(1) and bpo-26567(2)).

When a *note ResourceWarning: 54d. warning is logged, the *note
tracemalloc: 105. module is now used to try to retrieve the traceback
where the destroyed object was allocated.

Example with the script ‘example.py’:

     import warnings

     def func():
         return open(__file__)

     f = func()
     f = None

Output of the command ‘python3.6 -Wd -X tracemalloc=5 example.py’:

     example.py:7: ResourceWarning: unclosed file <_io.TextIOWrapper name='example.py' mode='r' encoding='UTF-8'>
       f = None
     Object allocated at (most recent call first):
       File "example.py", lineno 4
         return open(__file__)
       File "example.py", lineno 6
         f = func()

The «Object allocated at» traceback is new and is only displayed if
*note tracemalloc: 105. is tracing Python memory allocations and if the
*note warnings: 118. module was already imported.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26568

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26567


File: python.info,  Node: winreg,  Next: winsound,  Prev: warnings<4>,  Up: Improved Modules<7>

1.9.5.59 winreg
...............

Added the 64-bit integer type *note REG_QWORD: f01.  (Contributed by
Clement Rouault in bpo-23026(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23026


File: python.info,  Node: winsound,  Next: xmlrpc client,  Prev: winreg,  Up: Improved Modules<7>

1.9.5.60 winsound
.................

Allowed keyword arguments to be passed to *note Beep: f03, *note
MessageBeep: f04, and *note PlaySound: f05. (bpo-27982(1)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27982


File: python.info,  Node: xmlrpc client,  Next: zipfile<4>,  Prev: winsound,  Up: Improved Modules<7>

1.9.5.61 xmlrpc.client
......................

The *note xmlrpc.client: 134. module now supports unmarshalling
additional data types used by the Apache XML-RPC implementation for
numerics and ‘None’.  (Contributed by Serhiy Storchaka in bpo-26885(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26885


File: python.info,  Node: zipfile<4>,  Next: zlib<2>,  Prev: xmlrpc client,  Up: Improved Modules<7>

1.9.5.62 zipfile
................

A new *note ZipInfo.from_file(): f08. class method allows making a *note
ZipInfo: 2cb. instance from a filesystem file.  A new *note
ZipInfo.is_dir(): f09. method can be used to check if the *note ZipInfo:
2cb. instance represents a directory.  (Contributed by Thomas Kluyver in
bpo-26039(1).)

The *note ZipFile.open(): 65d. method can now be used to write data into
a ZIP file, as well as for extracting data.  (Contributed by Thomas
Kluyver in bpo-26039(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26039

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26039


File: python.info,  Node: zlib<2>,  Prev: zipfile<4>,  Up: Improved Modules<7>

1.9.5.63 zlib
.............

The *note compress(): 850. and *note decompress(): f0b. functions now
accept keyword arguments.  (Contributed by Aviv Palivoda in bpo-26243(1)
and Xiang Zhang in bpo-16764(2) respectively.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26243

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16764


File: python.info,  Node: Optimizations<8>,  Next: Build and C API Changes<2>,  Prev: Improved Modules<7>,  Up: What’s New In Python 3 6

1.9.6 Optimizations
-------------------

   * The Python interpreter now uses a 16-bit wordcode instead of
     bytecode which made a number of opcode optimizations possible.
     (Contributed by Demur Rumed with input and reviews from Serhiy
     Storchaka and Victor Stinner in bpo-26647(1) and bpo-28050(2).)

   * The *note asyncio.Future: dc8. class now has an optimized C
     implementation.  (Contributed by Yury Selivanov and INADA Naoki in
     bpo-26081(3).)

   * The *note asyncio.Task: 1c7. class now has an optimized C
     implementation.  (Contributed by Yury Selivanov in bpo-28544(4).)

   * Various implementation improvements in the *note typing: 10a.
     module (such as caching of generic types) allow up to 30 times
     performance improvements and reduced memory footprint.

   * The ASCII decoder is now up to 60 times as fast for error handlers
     ‘surrogateescape’, ‘ignore’ and ‘replace’ (Contributed by Victor
     Stinner in bpo-24870(5)).

   * The ASCII and the Latin1 encoders are now up to 3 times as fast for
     the error handler ‘surrogateescape’ (Contributed by Victor Stinner
     in bpo-25227(6)).

   * The UTF-8 encoder is now up to 75 times as fast for error handlers
     ‘ignore’, ‘replace’, ‘surrogateescape’, ‘surrogatepass’
     (Contributed by Victor Stinner in bpo-25267(7)).

   * The UTF-8 decoder is now up to 15 times as fast for error handlers
     ‘ignore’, ‘replace’ and ‘surrogateescape’ (Contributed by Victor
     Stinner in bpo-25301(8)).

   * ‘bytes % args’ is now up to 2 times faster.  (Contributed by Victor
     Stinner in bpo-25349(9)).

   * ‘bytearray % args’ is now between 2.5 and 5 times faster.
     (Contributed by Victor Stinner in bpo-25399(10)).

   * Optimize *note bytes.fromhex(): 190. and *note bytearray.fromhex():
     191.: they are now between 2x and 3.5x faster.  (Contributed by
     Victor Stinner in bpo-25401(11)).

   * Optimize ‘bytes.replace(b'', b'.')’ and ‘bytearray.replace(b'',
     b'.')’: up to 80% faster.  (Contributed by Josh Snider in
     bpo-26574(12)).

   * Allocator functions of the *note PyMem_Malloc(): e62. domain (*note
     PYMEM_DOMAIN_MEM: e65.) now use the *note pymalloc memory
     allocator: f0d. instead of ‘malloc()’ function of the C library.
     The pymalloc allocator is optimized for objects smaller or equal to
     512 bytes with a short lifetime, and use ‘malloc()’ for larger
     memory blocks.  (Contributed by Victor Stinner in bpo-26249(13)).

   * *note pickle.load(): f0e. and *note pickle.loads(): f0f. are now up
     to 10% faster when deserializing many small objects (Contributed by
     Victor Stinner in bpo-27056(14)).

   * Passing *note keyword arguments: f10. to a function has an overhead
     in comparison with passing *note positional arguments: f11.  Now in
     extension functions implemented with using Argument Clinic this
     overhead is significantly decreased.  (Contributed by Serhiy
     Storchaka in bpo-27574(15)).

   * Optimized *note glob(): 5a0. and *note iglob(): a0a. functions in
     the *note glob: 68. module; they are now about 3–6 times faster.
     (Contributed by Serhiy Storchaka in bpo-25596(16)).

   * Optimized globbing in *note pathlib: a8. by using *note
     os.scandir(): c56.; it is now about 1.5–4 times faster.
     (Contributed by Serhiy Storchaka in bpo-26032(17)).

   * *note xml.etree.ElementTree: 12b. parsing, iteration and deepcopy
     performance has been significantly improved.  (Contributed by
     Serhiy Storchaka in bpo-25638(18), bpo-25873(19), and
     bpo-25869(20).)

   * Creation of *note fractions.Fraction: 213. instances from floats
     and decimals is now 2 to 3 times faster.  (Contributed by Serhiy
     Storchaka in bpo-25971(21).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26647

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28050

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26081

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28544

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24870

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25227

   (7) https://bugs.python.org/issue?@action=redirect&bpo=25267

   (8) https://bugs.python.org/issue?@action=redirect&bpo=25301

   (9) https://bugs.python.org/issue?@action=redirect&bpo=25349

   (10) https://bugs.python.org/issue?@action=redirect&bpo=25399

   (11) https://bugs.python.org/issue?@action=redirect&bpo=25401

   (12) https://bugs.python.org/issue?@action=redirect&bpo=26574

   (13) https://bugs.python.org/issue?@action=redirect&bpo=26249

   (14) https://bugs.python.org/issue?@action=redirect&bpo=27056

   (15) https://bugs.python.org/issue?@action=redirect&bpo=27574

   (16) https://bugs.python.org/issue?@action=redirect&bpo=25596

   (17) https://bugs.python.org/issue?@action=redirect&bpo=26032

   (18) https://bugs.python.org/issue?@action=redirect&bpo=25638

   (19) https://bugs.python.org/issue?@action=redirect&bpo=25873

   (20) https://bugs.python.org/issue?@action=redirect&bpo=25869

   (21) https://bugs.python.org/issue?@action=redirect&bpo=25971


File: python.info,  Node: Build and C API Changes<2>,  Next: Other Improvements,  Prev: Optimizations<8>,  Up: What’s New In Python 3 6

1.9.7 Build and C API Changes
-----------------------------

   * Python now requires some C99 support in the toolchain to build.
     Most notably, Python now uses standard integer types and macros in
     place of custom macros like ‘PY_LONG_LONG’.  For more information,
     see PEP 7(1) and bpo-17884(2).

   * Cross-compiling CPython with the Android NDK and the Android API
     level set to 21 (Android 5.0 Lollipop) or greater runs
     successfully.  While Android is not yet a supported platform, the
     Python test suite runs on the Android emulator with only about 16
     tests failures.  See the Android meta-issue bpo-26865(3).

   * The ‘--enable-optimizations’ configure flag has been added.
     Turning it on will activate expensive optimizations like PGO.
     (Original patch by Alecsandru Patrascu of Intel in bpo-26359(4).)

   * The *note GIL: 474. must now be held when allocator functions of
     *note PYMEM_DOMAIN_OBJ: e63. (ex: *note PyObject_Malloc(): e64.)
     and *note PYMEM_DOMAIN_MEM: e65. (ex: *note PyMem_Malloc(): e62.)
     domains are called.

   * New *note Py_FinalizeEx(): f13. API which indicates if flushing
     buffered data failed.  (Contributed by Martin Panter in
     bpo-5319(5).)

   * *note PyArg_ParseTupleAndKeywords(): 624. now supports *note
     positional-only parameters: c7a.  Positional-only parameters are
     defined by empty names.  (Contributed by Serhiy Storchaka in
     bpo-26282(6)).

   * ‘PyTraceback_Print’ method now abbreviates long sequences of
     repeated lines as ‘"[Previous line repeated {count} more times]"’.
     (Contributed by Emanuel Barry in bpo-26823(7).)

   * The new *note PyErr_SetImportErrorSubclass(): f14. function allows
     for specifying a subclass of *note ImportError: 65b. to raise.
     (Contributed by Eric Snow in bpo-15767(8).)

   * The new *note PyErr_ResourceWarning(): f15. function can be used to
     generate a *note ResourceWarning: 54d. providing the source of the
     resource allocation.  (Contributed by Victor Stinner in
     bpo-26567(9).)

   * The new *note PyOS_FSPath(): f16. function returns the file system
     representation of a *note path-like object: 5a1.  (Contributed by
     Brett Cannon in bpo-27186(10).)

   * The *note PyUnicode_FSConverter(): f17. and *note
     PyUnicode_FSDecoder(): 798. functions will now accept *note
     path-like objects: 5a1.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0007/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17884

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26865

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26359

   (5) https://bugs.python.org/issue?@action=redirect&bpo=5319

   (6) https://bugs.python.org/issue?@action=redirect&bpo=26282

   (7) https://bugs.python.org/issue?@action=redirect&bpo=26823

   (8) https://bugs.python.org/issue?@action=redirect&bpo=15767

   (9) https://bugs.python.org/issue?@action=redirect&bpo=26567

   (10) https://bugs.python.org/issue?@action=redirect&bpo=27186


File: python.info,  Node: Other Improvements,  Next: Deprecated<8>,  Prev: Build and C API Changes<2>,  Up: What’s New In Python 3 6

1.9.8 Other Improvements
------------------------

   * When *note -version: f19. (short form: *note -V: 49c.) is supplied
     twice, Python prints *note sys.version: 49d. for detailed
     information.

          $ ./python -VV
          Python 3.6.0b4+ (3.6:223967b49e49+, Nov 21 2016, 20:55:04)
          [GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)]


File: python.info,  Node: Deprecated<8>,  Next: Removed<8>,  Prev: Other Improvements,  Up: What’s New In Python 3 6

1.9.9 Deprecated
----------------

* Menu:

* New Keywords::
* Deprecated Python behavior::
* Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<2>.
* xml: xml<6>.
* Deprecated functions and types of the C API: Deprecated functions and types of the C API<2>.
* Deprecated Build Options::


File: python.info,  Node: New Keywords,  Next: Deprecated Python behavior,  Up: Deprecated<8>

1.9.9.1 New Keywords
....................

‘async’ and ‘await’ are not recommended to be used as variable, class,
function or module names.  Introduced by PEP 492(1) in Python 3.5, they
will become proper keywords in Python 3.7.  Starting in Python 3.6, the
use of ‘async’ or ‘await’ as names will generate a *note
DeprecationWarning: 1a3.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0492/


File: python.info,  Node: Deprecated Python behavior,  Next: Deprecated Python modules functions and methods<2>,  Prev: New Keywords,  Up: Deprecated<8>

1.9.9.2 Deprecated Python behavior
..................................

Raising the *note StopIteration: df7. exception inside a generator will
now generate a *note DeprecationWarning: 1a3, and will trigger a *note
RuntimeError: 244. in Python 3.7.  See *note PEP 479; Change
StopIteration handling inside generators: f1d. for details.

The *note __aiter__(): df8. method is now expected to return an
asynchronous iterator directly instead of returning an awaitable as
previously.  Doing the former will trigger a *note DeprecationWarning:
1a3.  Backward compatibility will be removed in Python 3.7.
(Contributed by Yury Selivanov in bpo-27243(1).)

A backslash-character pair that is not a valid escape sequence now
generates a *note DeprecationWarning: 1a3.  Although this will
eventually become a *note SyntaxError: 18e, that will not be for several
Python releases.  (Contributed by Emanuel Barry in bpo-27364(2).)

When performing a relative import, falling back on ‘__name__’ and
‘__path__’ from the calling module when ‘__spec__’ or ‘__package__’ are
not defined now raises an *note ImportWarning: 71f.  (Contributed by
Rose Ames in bpo-25791(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27243

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27364

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25791


File: python.info,  Node: Deprecated Python modules functions and methods<2>,  Next: xml<6>,  Prev: Deprecated Python behavior,  Up: Deprecated<8>

1.9.9.3 Deprecated Python modules, functions and methods
........................................................

* Menu:

* asynchat::
* asyncore::
* dbm: dbm<4>.
* distutils: distutils<6>.
* grp::
* importlib: importlib<7>.
* os: os<10>.
* re: re<7>.
* ssl: ssl<9>.
* tkinter: tkinter<8>.
* venv: venv<6>.


File: python.info,  Node: asynchat,  Next: asyncore,  Up: Deprecated Python modules functions and methods<2>

1.9.9.4 asynchat
................

The ‘asynchat’ has been deprecated in favor of *note asyncio: b.
(Contributed by Mariatta in bpo-25002(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25002


File: python.info,  Node: asyncore,  Next: dbm<4>,  Prev: asynchat,  Up: Deprecated Python modules functions and methods<2>

1.9.9.5 asyncore
................

The ‘asyncore’ has been deprecated in favor of *note asyncio: b.
(Contributed by Mariatta in bpo-25002(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25002


File: python.info,  Node: dbm<4>,  Next: distutils<6>,  Prev: asyncore,  Up: Deprecated Python modules functions and methods<2>

1.9.9.6 dbm
...........

Unlike other *note dbm: 35. implementations, the *note dbm.dumb: 36.
module creates databases with the ‘'rw'’ mode and allows modifying the
database opened with the ‘'r'’ mode.  This behavior is now deprecated
and will be removed in 3.8.  (Contributed by Serhiy Storchaka in
bpo-21708(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21708


File: python.info,  Node: distutils<6>,  Next: grp,  Prev: dbm<4>,  Up: Deprecated Python modules functions and methods<2>

1.9.9.7 distutils
.................

The undocumented ‘extra_path’ argument to the ‘distutils.Distribution’
constructor is now considered deprecated and will raise a warning if
set.  Support for this parameter will be removed in a future Python
release.  See bpo-27919(1) for details.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27919


File: python.info,  Node: grp,  Next: importlib<7>,  Prev: distutils<6>,  Up: Deprecated Python modules functions and methods<2>

1.9.9.8 grp
...........

The support of non-integer arguments in *note getgrgid(): f24. has been
deprecated.  (Contributed by Serhiy Storchaka in bpo-26129(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26129


File: python.info,  Node: importlib<7>,  Next: os<10>,  Prev: grp,  Up: Deprecated Python modules functions and methods<2>

1.9.9.9 importlib
.................

The *note importlib.machinery.SourceFileLoader.load_module(): f26. and
*note importlib.machinery.SourcelessFileLoader.load_module(): f27.
methods are now deprecated.  They were the only remaining
implementations of *note importlib.abc.Loader.load_module(): a6b. in
*note importlib: 7b. that had not been deprecated in previous versions
of Python in favour of *note importlib.abc.Loader.exec_module(): a6c.

The *note importlib.machinery.WindowsRegistryFinder: f28. class is now
deprecated.  As of 3.6.0, it is still added to *note sys.meta_path: f29.
by default (on Windows), but this may change in future releases.


File: python.info,  Node: os<10>,  Next: re<7>,  Prev: importlib<7>,  Up: Deprecated Python modules functions and methods<2>

1.9.9.10 os
...........

Undocumented support of general *note bytes-like objects: 193. as paths
in *note os: a5. functions, *note compile(): 4b2. and similar functions
is now deprecated.  (Contributed by Serhiy Storchaka in bpo-25791(1) and
bpo-26754(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25791

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26754


File: python.info,  Node: re<7>,  Next: ssl<9>,  Prev: os<10>,  Up: Deprecated Python modules functions and methods<2>

1.9.9.11 re
...........

Support for inline flags ‘(?letters)’ in the middle of the regular
expression has been deprecated and will be removed in a future Python
version.  Flags at the start of a regular expression are still allowed.
(Contributed by Serhiy Storchaka in bpo-22493(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22493


File: python.info,  Node: ssl<9>,  Next: tkinter<8>,  Prev: re<7>,  Up: Deprecated Python modules functions and methods<2>

1.9.9.12 ssl
............

OpenSSL 0.9.8, 1.0.0 and 1.0.1 are deprecated and no longer supported.
In the future the *note ssl: d5. module will require at least OpenSSL
1.0.2 or 1.1.0.

SSL-related arguments like ‘certfile’, ‘keyfile’ and ‘check_hostname’ in
*note ftplib: 62, *note http.client: 73, *note imaplib: 78, *note
poplib: b1, and *note smtplib: cf. have been deprecated in favor of
‘context’.  (Contributed by Christian Heimes in bpo-28022(1).)

A couple of protocols and functions of the *note ssl: d5. module are now
deprecated.  Some features will no longer be available in future
versions of OpenSSL. Other features are deprecated in favor of a
different API. (Contributed by Christian Heimes in bpo-28022(2) and
bpo-26470(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28022

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28022

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26470


File: python.info,  Node: tkinter<8>,  Next: venv<6>,  Prev: ssl<9>,  Up: Deprecated Python modules functions and methods<2>

1.9.9.13 tkinter
................

The ‘tkinter.tix’ module is now deprecated.  *note tkinter: f6. users
should use *note tkinter.ttk: ff. instead.


File: python.info,  Node: venv<6>,  Prev: tkinter<8>,  Up: Deprecated Python modules functions and methods<2>

1.9.9.14 venv
.............

The ‘pyvenv’ script has been deprecated in favour of ‘python3 -m venv’.
This prevents confusion as to what Python interpreter ‘pyvenv’ is
connected to and thus what Python interpreter will be used by the
virtual environment.  (Contributed by Brett Cannon in bpo-25154(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25154


File: python.info,  Node: xml<6>,  Next: Deprecated functions and types of the C API<2>,  Prev: Deprecated Python modules functions and methods<2>,  Up: Deprecated<8>

1.9.9.15 xml
............

   * As mitigation against DTD and external entity retrieval, the *note
     xml.dom.minidom: 128. and *note xml.sax: 12f. modules no longer
     process external entities by default.  (Contributed by Christian
     Heimes in gh-61441(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/61441


File: python.info,  Node: Deprecated functions and types of the C API<2>,  Next: Deprecated Build Options,  Prev: xml<6>,  Up: Deprecated<8>

1.9.9.16 Deprecated functions and types of the C API
....................................................

Undocumented functions ‘PyUnicode_AsEncodedObject()’,
‘PyUnicode_AsDecodedObject()’, ‘PyUnicode_AsEncodedUnicode()’ and
‘PyUnicode_AsDecodedUnicode()’ are deprecated now.  Use the *note
generic codec based API: f32. instead.


File: python.info,  Node: Deprecated Build Options,  Prev: Deprecated functions and types of the C API<2>,  Up: Deprecated<8>

1.9.9.17 Deprecated Build Options
.................................

The ‘--with-system-ffi’ configure flag is now on by default on non-macOS
UNIX platforms.  It may be disabled by using ‘--without-system-ffi’, but
using the flag is deprecated and will not be accepted in Python 3.7.
macOS is unaffected by this change.  Note that many OS distributors
already use the ‘--with-system-ffi’ flag when building their system
Python.


File: python.info,  Node: Removed<8>,  Next: Porting to Python 3 6,  Prev: Deprecated<8>,  Up: What’s New In Python 3 6

1.9.10 Removed
--------------

* Menu:

* API and Feature Removals: API and Feature Removals<3>.


File: python.info,  Node: API and Feature Removals<3>,  Up: Removed<8>

1.9.10.1 API and Feature Removals
.................................

   * Unknown escapes consisting of ‘'\'’ and an ASCII letter in regular
     expressions will now cause an error.  In replacement templates for
     *note re.sub(): 5a3. they are still allowed, but deprecated.  The
     *note re.LOCALE: d65. flag can now only be used with binary
     patterns.

   * ‘inspect.getmoduleinfo()’ was removed (was deprecated since CPython
     3.3).  *note inspect.getmodulename(): f36. should be used for
     obtaining the module name for a given path.  (Contributed by Yury
     Selivanov in bpo-13248(1).)

   * ‘traceback.Ignore’ class and ‘traceback.usage’,
     ‘traceback.modname’, ‘traceback.fullmodname’,
     ‘traceback.find_lines_from_code’, ‘traceback.find_lines’,
     ‘traceback.find_strings’, ‘traceback.find_executable_lines’ methods
     were removed from the *note traceback: 104. module.  They were
     undocumented methods deprecated since Python 3.2 and equivalent
     functionality is available from private methods.

   * The ‘tk_menuBar()’ and ‘tk_bindForTraversal()’ dummy methods in
     *note tkinter: f6. widget classes were removed (corresponding Tk
     commands were obsolete since Tk 4.0).

   * The *note open(): 65d. method of the *note zipfile.ZipFile: 8d4.
     class no longer supports the ‘'U'’ mode (was deprecated since
     Python 3.4).  Use *note io.TextIOWrapper: 9c0. for reading
     compressed text files in *note universal newlines: f37. mode.

   * The undocumented ‘IN’, ‘CDROM’, ‘DLFCN’, ‘TYPES’, ‘CDIO’, and
     ‘STROPTS’ modules have been removed.  They had been available in
     the platform specific ‘Lib/plat-*/’ directories, but were
     chronically out of date, inconsistently available across platforms,
     and unmaintained.  The script that created these modules is still
     available in the source distribution at Tools/scripts/h2py.py(2).

   * The deprecated ‘asynchat.fifo’ class has been removed.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13248

   (2) 
https://github.com/python/cpython/blob/v3.6.15/Tools/scripts/h2py.py


File: python.info,  Node: Porting to Python 3 6,  Next: Notable changes in Python 3 6 2,  Prev: Removed<8>,  Up: What’s New In Python 3 6

1.9.11 Porting to Python 3.6
----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code.

* Menu:

* Changes in “python” Command Behavior::
* Changes in the Python API: Changes in the Python API<8>.
* Changes in the C API: Changes in the C API<7>.
* CPython bytecode changes: CPython bytecode changes<7>.


File: python.info,  Node: Changes in “python” Command Behavior,  Next: Changes in the Python API<8>,  Up: Porting to Python 3 6

1.9.11.1 Changes in “python” Command Behavior
.............................................

   * The output of a special Python build with defined ‘COUNT_ALLOCS’,
     ‘SHOW_ALLOC_COUNT’ or ‘SHOW_TRACK_COUNT’ macros is now off by
     default.  It can be re-enabled using the ‘-X showalloccount’
     option.  It now outputs to ‘stderr’ instead of ‘stdout’.
     (Contributed by Serhiy Storchaka in bpo-23034(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23034


File: python.info,  Node: Changes in the Python API<8>,  Next: Changes in the C API<7>,  Prev: Changes in “python” Command Behavior,  Up: Porting to Python 3 6

1.9.11.2 Changes in the Python API
..................................

   * *note open(): 316. will no longer allow combining the ‘'U'’ mode
     flag with ‘'+'’.  (Contributed by Jeff Balogh and John O’Connor in
     bpo-2091(1).)

   * *note sqlite3: d4. no longer implicitly commits an open transaction
     before DDL statements.

   * On Linux, *note os.urandom(): 747. now blocks until the system
     urandom entropy pool is initialized to increase the security.

   * When *note importlib.abc.Loader.exec_module(): a6c. is defined,
     *note importlib.abc.Loader.create_module(): eae. must also be
     defined.

   * *note PyErr_SetImportError(): f3b. now sets *note TypeError: 198.
     when its 'msg' argument is not set.  Previously only ‘NULL’ was
     returned.

   * The format of the *note co_lnotab: 330. attribute of code objects
     changed to support a negative line number delta.  By default,
     Python does not emit bytecode with a negative line number delta.
     Functions using *note frame.f_lineno: 9b1,
     ‘PyFrame_GetLineNumber()’ or ‘PyCode_Addr2Line()’ are not affected.
     Functions directly decoding ‘co_lnotab’ should be updated to use a
     signed 8-bit integer type for the line number delta, but this is
     only required to support applications using a negative line number
     delta.  See ‘Objects/lnotab_notes.txt’ for the ‘co_lnotab’ format
     and how to decode it, and see the PEP 511(2) for the rationale.

   * The functions in the *note compileall: 21. module now return
     booleans instead of ‘1’ or ‘0’ to represent success or failure,
     respectively.  Thanks to booleans being a subclass of integers,
     this should only be an issue if you were doing identity checks for
     ‘1’ or ‘0’.  See bpo-25768(3).

   * Reading the ‘port’ attribute of *note urllib.parse.urlsplit(): f3c.
     and *note urlparse(): 362. results now raises *note ValueError:
     2ec. for out-of-range values, rather than returning *note None:
     886.  See bpo-20059(4).

   * The ‘imp’ module now raises a *note DeprecationWarning: 1a3.
     instead of *note PendingDeprecationWarning: ac8.

   * The following modules have had missing APIs added to their *note
     __all__: f3d. attributes to match the documented APIs: *note
     calendar: 15, ‘cgi’, *note csv: 2d, *note ElementTree: 12b, *note
     enum: 5a, *note fileinput: 5f, *note ftplib: 62, *note logging: 8b,
     *note mailbox: 8f, *note mimetypes: 93, *note optparse: a4, *note
     plistlib: b0, ‘smtpd’, *note subprocess: dc, *note tarfile: e4,
     *note threading: f3. and *note wave: 119.  This means they will
     export new symbols when ‘import *’ is used.  (Contributed by Joel
     Taddei and Jacek Kołodziej in bpo-23883(5).)

   * When performing a relative import, if ‘__package__’ does not
     compare equal to ‘__spec__.parent’ then *note ImportWarning: 71f.
     is raised.  (Contributed by Brett Cannon in bpo-25791(6).)

   * When a relative import is performed and no parent package is known,
     then *note ImportError: 65b. will be raised.  Previously, *note
     SystemError: 796. could be raised.  (Contributed by Brett Cannon in
     bpo-18018(7).)

   * Servers based on the *note socketserver: d2. module, including
     those defined in *note http.server: 76, *note xmlrpc.server: 135.
     and *note wsgiref.simple_server: 121, now only catch exceptions
     derived from *note Exception: bcf.  Therefore if a request handler
     raises an exception like *note SystemExit: f3e. or *note
     KeyboardInterrupt: bc7, *note handle_error(): f3f. is no longer
     called, and the exception will stop a single-threaded server.
     (Contributed by Martin Panter in bpo-23430(8).)

   * ‘spwd.getspnam()’ now raises a *note PermissionError: f40. instead
     of *note KeyError: 5e7. if the user doesn’t have privileges.

   * The *note socket.socket.close(): f41. method now raises an
     exception if an error (e.g.  ‘EBADF’) was reported by the
     underlying system call.  (Contributed by Martin Panter in
     bpo-26685(9).)

   * The 'decode_data' argument for the ‘smtpd.SMTPChannel’ and
     ‘smtpd.SMTPServer’ constructors is now ‘False’ by default.  This
     means that the argument passed to ‘process_message()’ is now a
     bytes object by default, and ‘process_message()’ will be passed
     keyword arguments.  Code that has already been updated in
     accordance with the deprecation warning generated by 3.5 will not
     be affected.

   * All optional arguments of the *note dump(): f42, *note dumps():
     f43, *note load(): eb4. and *note loads(): b50. functions and *note
     JSONEncoder: f44. and *note JSONDecoder: f45. class constructors in
     the *note json: 86. module are now *note keyword-only: 5a5.
     (Contributed by Serhiy Storchaka in bpo-18726(10).)

   * Subclasses of *note type: f46. which don’t override ‘type.__new__’
     may no longer use the one-argument form to get the type of an
     object.

   * As part of PEP 487(11), the handling of keyword arguments passed to
     *note type: f46. (other than the metaclass hint, ‘metaclass’) is
     now consistently delegated to *note object.__init_subclass__():
     844.  This means that *note type.__new__: 7a1. and *note
     type.__init__: 8c0. both now accept arbitrary keyword arguments,
     but *note object.__init_subclass__(): 844. (which is called from
     *note type.__new__: 7a1.) will reject them by default.  Custom
     metaclasses accepting additional keyword arguments will need to
     adjust their calls to *note type.__new__: 7a1. (whether direct or
     via *note super: 1a6.) accordingly.

   * In ‘distutils.command.sdist.sdist’, the ‘default_format’ attribute
     has been removed and is no longer honored.  Instead, the gzipped
     tarfile format is the default on all platforms and no
     platform-specific selection is made.  In environments where
     distributions are built on Windows and zip distributions are
     required, configure the project with a ‘setup.cfg’ file containing
     the following:

          [sdist]
          formats=zip

     This behavior has also been backported to earlier Python versions
     by Setuptools 26.0.0.

   * In the *note urllib.request: 111. module and the *note
     http.client.HTTPConnection.request(): ea9. method, if no
     Content-Length header field has been specified and the request body
     is a file object, it is now sent with HTTP 1.1 chunked encoding.
     If a file object has to be sent to a HTTP 1.0 server, the
     Content-Length value now has to be specified by the caller.
     (Contributed by Demian Brecht and Rolf Krahl with tweaks from
     Martin Panter in bpo-12319(12).)

   * The *note DictReader: bda. now returns rows of type *note
     OrderedDict: 7f4.  (Contributed by Steve Holden in bpo-27842(13).)

   * The ‘crypt.METHOD_CRYPT’ will no longer be added to ‘crypt.methods’
     if unsupported by the platform.  (Contributed by Victor Stinner in
     bpo-25287(14).)

   * The 'verbose' and 'rename' arguments for *note namedtuple(): 4e1.
     are now keyword-only.  (Contributed by Raymond Hettinger in
     bpo-25628(15).)

   * On Linux, *note ctypes.util.find_library(): f47. now looks in
     ‘LD_LIBRARY_PATH’ for shared libraries.  (Contributed by Vinay
     Sajip in bpo-9998(16).)

   * The *note imaplib.IMAP4: b01. class now handles flags containing
     the ‘']'’ character in messages sent from the server to improve
     real-world compatibility.  (Contributed by Lita Cho in
     bpo-21815(17).)

   * The *note mmap.mmap.write(): f48. function now returns the number
     of bytes written like other write methods.  (Contributed by Jakub
     Stasiak in bpo-26335(18).)

   * The *note pkgutil.iter_modules(): f49. and *note
     pkgutil.walk_packages(): dfb. functions now return *note
     ModuleInfo: f4a. named tuples.  (Contributed by Ramchandra Apte in
     bpo-17211(19).)

   * *note re.sub(): 5a3. now raises an error for invalid numerical
     group references in replacement templates even if the pattern is
     not found in the string.  The error message for invalid group
     references now includes the group index and the position of the
     reference.  (Contributed by SilentGhost, Serhiy Storchaka in
     bpo-25953(20).)

   * *note zipfile.ZipFile: 8d4. will now raise *note
     NotImplementedError: 36b. for unrecognized compression values.
     Previously a plain *note RuntimeError: 244. was raised.
     Additionally, calling *note ZipFile: 8d4. methods on a closed
     ZipFile or calling the *note write(): f4b. method on a ZipFile
     created with mode ‘'r'’ will raise a *note ValueError: 2ec.
     Previously, a *note RuntimeError: 244. was raised in those
     scenarios.

   * when custom metaclasses are combined with zero-argument *note
     super(): 1a6. or direct references from methods to the implicit
     ‘__class__’ closure variable, the implicit ‘__classcell__’
     namespace entry must now be passed up to ‘type.__new__’ for
     initialisation.  Failing to do so will result in a *note
     DeprecationWarning: 1a3. in Python 3.6 and a *note RuntimeError:
     244. in Python 3.8.

   * With the introduction of *note ModuleNotFoundError: d3f, import
     system consumers may start expecting import system replacements to
     raise that more specific exception when appropriate, rather than
     the less-specific *note ImportError: 65b.  To provide future
     compatibility with such consumers, implementers of alternative
     import systems that completely replace *note __import__(): ad3.
     will need to update their implementations to raise the new subclass
     when a module can’t be found at all.  Implementers of compliant
     plugins to the default import system shouldn’t need to make any
     changes, as the default import system will raise the new subclass
     when appropriate.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=2091

   (2) https://peps.python.org/pep-0511/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25768

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20059

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23883

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25791

   (7) https://bugs.python.org/issue?@action=redirect&bpo=18018

   (8) https://bugs.python.org/issue?@action=redirect&bpo=23430

   (9) https://bugs.python.org/issue?@action=redirect&bpo=26685

   (10) https://bugs.python.org/issue?@action=redirect&bpo=18726

   (11) https://peps.python.org/pep-0487/

   (12) https://bugs.python.org/issue?@action=redirect&bpo=12319

   (13) https://bugs.python.org/issue?@action=redirect&bpo=27842

   (14) https://bugs.python.org/issue?@action=redirect&bpo=25287

   (15) https://bugs.python.org/issue?@action=redirect&bpo=25628

   (16) https://bugs.python.org/issue?@action=redirect&bpo=9998

   (17) https://bugs.python.org/issue?@action=redirect&bpo=21815

   (18) https://bugs.python.org/issue?@action=redirect&bpo=26335

   (19) https://bugs.python.org/issue?@action=redirect&bpo=17211

   (20) https://bugs.python.org/issue?@action=redirect&bpo=25953


File: python.info,  Node: Changes in the C API<7>,  Next: CPython bytecode changes<7>,  Prev: Changes in the Python API<8>,  Up: Porting to Python 3 6

1.9.11.3 Changes in the C API
.............................

   * The *note PyMem_Malloc(): e62. allocator family now uses the *note
     pymalloc allocator: f0d. rather than the system ‘malloc()’.
     Applications calling *note PyMem_Malloc(): e62. without holding the
     GIL can now crash.  Set the *note PYTHONMALLOC: e60. environment
     variable to ‘debug’ to validate the usage of memory allocators in
     your application.  See bpo-26249(1).

   * *note Py_Exit(): f4d. (and the main interpreter) now override the
     exit status with 120 if flushing buffered data failed.  See
     bpo-5319(2).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26249

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5319


File: python.info,  Node: CPython bytecode changes<7>,  Prev: Changes in the C API<7>,  Up: Porting to Python 3 6

1.9.11.4 CPython bytecode changes
.................................

There have been several major changes to the *note bytecode: 4ab. in
Python 3.6.

   * The Python interpreter now uses a 16-bit wordcode instead of
     bytecode.  (Contributed by Demur Rumed with input and reviews from
     Serhiy Storchaka and Victor Stinner in bpo-26647(1) and
     bpo-28050(2).)

   * The new ‘FORMAT_VALUE’ and *note BUILD_STRING: f4f. opcodes as part
     of the *note formatted string literal: e2b. implementation.
     (Contributed by Eric Smith in bpo-25483(3) and Serhiy Storchaka in
     bpo-27078(4).)

   * The new ‘BUILD_CONST_KEY_MAP’ opcode to optimize the creation of
     dictionaries with constant keys.  (Contributed by Serhiy Storchaka
     in bpo-27140(5).)

   * The function call opcodes have been heavily reworked for better
     performance and simpler implementation.  The *note MAKE_FUNCTION:
     f50, ‘CALL_FUNCTION’, ‘CALL_FUNCTION_KW’ and
     ‘BUILD_MAP_UNPACK_WITH_CALL’ opcodes have been modified, the new
     *note CALL_FUNCTION_EX: f51. and ‘BUILD_TUPLE_UNPACK_WITH_CALL’
     have been added, and ‘CALL_FUNCTION_VAR’, ‘CALL_FUNCTION_VAR_KW’
     and ‘MAKE_CLOSURE’ opcodes have been removed.  (Contributed by
     Demur Rumed in bpo-27095(6), and Serhiy Storchaka in bpo-27213(7),
     bpo-28257(8).)

   * The new *note SETUP_ANNOTATIONS: f52. and ‘STORE_ANNOTATION’
     opcodes have been added to support the new *note variable
     annotation: f53. syntax.  (Contributed by Ivan Levkivskyi in
     bpo-27985(9).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26647

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28050

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25483

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27078

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27140

   (6) https://bugs.python.org/issue?@action=redirect&bpo=27095

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27213

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28257

   (9) https://bugs.python.org/issue?@action=redirect&bpo=27985


File: python.info,  Node: Notable changes in Python 3 6 2,  Next: Notable changes in Python 3 6 4,  Prev: Porting to Python 3 6,  Up: What’s New In Python 3 6

1.9.12 Notable changes in Python 3.6.2
--------------------------------------

* Menu:

* New make regen-all build target::
* Removal of make touch build target::


File: python.info,  Node: New make regen-all build target,  Next: Removal of make touch build target,  Up: Notable changes in Python 3 6 2

1.9.12.1 New ‘make regen-all’ build target
..........................................

To simplify cross-compilation, and to ensure that CPython can reliably
be compiled without requiring an existing version of Python to already
be available, the autotools-based build system no longer attempts to
implicitly recompile generated files based on file modification times.

Instead, a new ‘make regen-all’ command has been added to force
regeneration of these files when desired (e.g.  after an initial version
of Python has already been built based on the pregenerated versions).

More selective regeneration targets are also defined - see
Makefile.pre.in(1) for details.

(Contributed by Victor Stinner in bpo-23404(2).)

Added in version 3.6.2.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Makefile.pre.in

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23404


File: python.info,  Node: Removal of make touch build target,  Prev: New make regen-all build target,  Up: Notable changes in Python 3 6 2

1.9.12.2 Removal of ‘make touch’ build target
.............................................

The ‘make touch’ build target previously used to request implicit
regeneration of generated files by updating their modification times has
been removed.

It has been replaced by the new ‘make regen-all’ target.

(Contributed by Victor Stinner in bpo-23404(1).)

Cambiato nella versione 3.6.2.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23404


File: python.info,  Node: Notable changes in Python 3 6 4,  Next: Notable changes in Python 3 6 5,  Prev: Notable changes in Python 3 6 2,  Up: What’s New In Python 3 6

1.9.13 Notable changes in Python 3.6.4
--------------------------------------

The ‘PyExc_RecursionErrorInst’ singleton that was part of the public API
has been removed as its members being never cleared may cause a segfault
during finalization of the interpreter.  (Contributed by Xavier de Gaye
in bpo-22898(1) and bpo-30697(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22898

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30697


File: python.info,  Node: Notable changes in Python 3 6 5,  Next: Notable changes in Python 3 6 7,  Prev: Notable changes in Python 3 6 4,  Up: What’s New In Python 3 6

1.9.14 Notable changes in Python 3.6.5
--------------------------------------

The *note locale.localeconv(): dfa. function now sets temporarily the
‘LC_CTYPE’ locale to the ‘LC_NUMERIC’ locale in some cases.
(Contributed by Victor Stinner in bpo-31900(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31900


File: python.info,  Node: Notable changes in Python 3 6 7,  Next: Notable changes in Python 3 6 10,  Prev: Notable changes in Python 3 6 5,  Up: What’s New In Python 3 6

1.9.15 Notable changes in Python 3.6.7
--------------------------------------

*note xml.dom.minidom: 128. and *note xml.sax: 12f. modules no longer
process external entities by default.  See also gh-61441(1).

In 3.6.7 the *note tokenize: 101. module now implicitly emits a
‘NEWLINE’ token when provided with input that does not have a trailing
new line.  This behavior now matches what the C tokenizer does
internally.  (Contributed by Ammar Askar in bpo-33899(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/61441

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33899


File: python.info,  Node: Notable changes in Python 3 6 10,  Next: Notable changes in Python 3 6 13,  Prev: Notable changes in Python 3 6 7,  Up: What’s New In Python 3 6

1.9.16 Notable changes in Python 3.6.10
---------------------------------------

Due to significant security concerns, the 'reuse_address' parameter of
*note asyncio.loop.create_datagram_endpoint(): 93d. is no longer
supported.  This is because of the behavior of the socket option
‘SO_REUSEADDR’ in UDP. For more details, see the documentation for
‘loop.create_datagram_endpoint()’.  (Contributed by Kyle Stanley,
Antoine Pitrou, and Yury Selivanov in bpo-37228(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37228


File: python.info,  Node: Notable changes in Python 3 6 13,  Next: Notable changes in Python 3 6 14,  Prev: Notable changes in Python 3 6 10,  Up: What’s New In Python 3 6

1.9.17 Notable changes in Python 3.6.13
---------------------------------------

Earlier Python versions allowed using both ‘;’ and ‘&’ as query
parameter separators in *note urllib.parse.parse_qs(): 31f. and *note
urllib.parse.parse_qsl(): 31e.  Due to security concerns, and to conform
with newer W3C recommendations, this has been changed to allow only a
single separator key, with ‘&’ as the default.  This change also affects
‘cgi.parse()’ and ‘cgi.parse_multipart()’ as they use the affected
functions internally.  For more details, please see their respective
documentation.  (Contributed by Adam Goldschmidt, Senthil Kumaran and
Ken Jin in bpo-42967(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42967


File: python.info,  Node: Notable changes in Python 3 6 14,  Prev: Notable changes in Python 3 6 13,  Up: What’s New In Python 3 6

1.9.18 Notable changes in Python 3.6.14
---------------------------------------

A security fix alters the *note ftplib.FTP: af8. behavior to not trust
the IPv4 address sent from the remote server when setting up a passive
data channel.  We reuse the ftp server IP address instead.  For unusual
code requiring the old behavior, set a ‘trust_server_pasv_ipv4_address’
attribute on your FTP instance to ‘True’.  (See gh-87451(1))

The presence of newline or tab characters in parts of a URL allows for
some forms of attacks.  Following the WHATWG specification that updates
RFC 3986, ASCII newline ‘\n’, ‘\r’ and tab ‘\t’ characters are stripped
from the URL by the parser *note urllib.parse(): 110. preventing such
attacks.  The removal characters are controlled by a new module level
variable ‘urllib.parse._UNSAFE_URL_BYTES_TO_REMOVE’.  (See gh-88048(2))

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/87451

   (2) https://github.com/python/cpython/issues/88048


File: python.info,  Node: What’s New In Python 3 5,  Next: What’s New In Python 3 4,  Prev: What’s New In Python 3 6,  Up: Novità in Python

1.10 What’s New In Python 3.5
=============================


Editors: Elvis Pranskevichus <<elvis@magic.io>>, Yury Selivanov
<<yury@magic.io>>

This article explains the new features in Python 3.5, compared to 3.4.
Python 3.5 was released on September 13, 2015.  See the changelog(1) for
a full list of changes.

Vedi anche
..........

PEP 478(2) - Python 3.5 Release Schedule

* Menu:

* Summary – Release highlights: Summary – Release highlights<7>.
* New Features: New Features<12>.
* Other Language Changes: Other Language Changes<8>.
* New Modules: New Modules<8>.
* Improved Modules: Improved Modules<8>.
* Other module-level changes::
* Optimizations: Optimizations<9>.
* Build and C API Changes: Build and C API Changes<3>.
* Deprecated: Deprecated<9>.
* Removed: Removed<9>.
* Porting to Python 3.5: Porting to Python 3 5.
* Notable changes in Python 3.5.4: Notable changes in Python 3 5 4.

   ---------- Footnotes ----------

   (1) https://docs.python.org/3.5/whatsnew/changelog.html

   (2) https://peps.python.org/pep-0478/


File: python.info,  Node: Summary – Release highlights<7>,  Next: New Features<12>,  Up: What’s New In Python 3 5

1.10.1 Summary – Release highlights
-----------------------------------

New syntax features:

   * *note PEP 492: f61, coroutines with async and await syntax.

   * *note PEP 465: f62, a new matrix multiplication operator: ‘a @ b’.

   * *note PEP 448: f63, additional unpacking generalizations.

New library modules:

   * *note typing: 10a.: *note PEP 484 – Type Hints: f64.

   * *note zipapp: 136.: *note PEP 441 Improving Python ZIP Application
     Support: f65.

New built-in features:

   * ‘bytes % args’, ‘bytearray % args’: *note PEP 461: f66. – Adding
     ‘%’ formatting to bytes and bytearray.

   * New *note bytes.hex(): f67, *note bytearray.hex(): f68. and *note
     memoryview.hex(): f69. methods.  (Contributed by Arnon Yaari in
     bpo-9951(1).)

   * *note memoryview: 165. now supports tuple indexing (including
     multi-dimensional).  (Contributed by Antoine Pitrou in
     bpo-23632(2).)

   * Generators have a new ‘gi_yieldfrom’ attribute, which returns the
     object being iterated by ‘yield from’ expressions.  (Contributed by
     Benno Leslie and Yury Selivanov in bpo-24450(3).)

   * A new *note RecursionError: f6a. exception is now raised when
     maximum recursion depth is reached.  (Contributed by Georg Brandl
     in bpo-19235(4).)

CPython implementation improvements:

   * When the ‘LC_TYPE’ locale is the POSIX locale (‘C’ locale), *note
     sys.stdin: 760. and *note sys.stdout: ccf. now use the
     ‘surrogateescape’ error handler, instead of the ‘strict’ error
     handler.  (Contributed by Victor Stinner in bpo-19977(5).)

   * ‘.pyo’ files are no longer used and have been replaced by a more
     flexible scheme that includes the optimization level explicitly in
     ‘.pyc’ name.  (See *note PEP 488 overview: f6b.)

   * Builtin and extension modules are now initialized in a multi-phase
     process, which is similar to how Python modules are loaded.  (See
     *note PEP 489 overview: f6c.)

Significant improvements in the standard library:

   * *note collections.OrderedDict: 7f4. is now *note implemented in C:
     f6d, which makes it 4 to 100 times faster.

   * The *note ssl: d5. module gained *note support for Memory BIO: f6e,
     which decouples SSL protocol handling from network IO.

   * The new *note os.scandir(): c56. function provides a *note better
     and significantly faster way: f6f. of directory traversal.

   * *note functools.lru_cache(): be4. has been mostly *note
     reimplemented in C: f70, yielding much better performance.

   * The new *note subprocess.run(): d81. function provides a *note
     streamlined way to run subprocesses: f71.

   * The *note traceback: 104. module has been significantly *note
     enhanced: f72. for improved performance and developer convenience.

Security improvements:

   * SSLv3 is now disabled throughout the standard library.  It can
     still be enabled by instantiating a *note ssl.SSLContext: 357.
     manually.  (See bpo-22638(6) for more details; this change was
     backported to CPython 3.4 and 2.7.)

   * HTTP cookie parsing is now stricter, in order to protect against
     potential injection attacks.  (Contributed by Antoine Pitrou in
     bpo-22796(7).)

Windows improvements:

   * A new installer for Windows has replaced the old MSI. See *note
     Using Python on Windows: ca0. for more information.

   * Windows builds now use Microsoft Visual C++ 14.0, and extension
     modules should use the same.

Please read on for a comprehensive list of user-facing changes,
including many other smaller improvements, CPython optimizations,
deprecations, and potential porting issues.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9951

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23632

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24450

   (4) https://bugs.python.org/issue?@action=redirect&bpo=19235

   (5) https://bugs.python.org/issue?@action=redirect&bpo=19977

   (6) https://bugs.python.org/issue?@action=redirect&bpo=22638

   (7) https://bugs.python.org/issue?@action=redirect&bpo=22796


File: python.info,  Node: New Features<12>,  Next: Other Language Changes<8>,  Prev: Summary – Release highlights<7>,  Up: What’s New In Python 3 5

1.10.2 New Features
-------------------

* Menu:

* PEP 492 - Coroutines with async and await syntax::
* PEP 465 - A dedicated infix operator for matrix multiplication::
* PEP 448 - Additional Unpacking Generalizations::
* PEP 461 - percent formatting support for bytes and bytearray::
* PEP 484 - Type Hints::
* PEP 471 - os.scandir() function – a better and faster directory iterator: PEP 471 - os scandir function – a better and faster directory iterator.
* PEP 475; Retry system calls failing with EINTR: PEP 475 Retry system calls failing with EINTR.
* PEP 479; Change StopIteration handling inside generators: PEP 479 Change StopIteration handling inside generators.
* PEP 485; A function for testing approximate equality: PEP 485 A function for testing approximate equality.
* PEP 486; Make the Python Launcher aware of virtual environments: PEP 486 Make the Python Launcher aware of virtual environments.
* PEP 488; Elimination of PYO files: PEP 488 Elimination of PYO files.
* PEP 489; Multi-phase extension module initialization: PEP 489 Multi-phase extension module initialization.


File: python.info,  Node: PEP 492 - Coroutines with async and await syntax,  Next: PEP 465 - A dedicated infix operator for matrix multiplication,  Up: New Features<12>

1.10.2.1 PEP 492 - Coroutines with async and await syntax
.........................................................

PEP 492(1) greatly improves support for asynchronous programming in
Python by adding *note awaitable objects: 4ca, *note coroutine
functions: f75, *note asynchronous iteration: f76, and *note
asynchronous context managers: 7f1.

Coroutine functions are declared using the new *note async def: 7ee.
syntax:

     >>> async def coro():
     ...     return 'spam'

Inside a coroutine function, the new *note await: 18d. expression can be
used to suspend coroutine execution until the result is available.  Any
object can be 'awaited', as long as it implements the *note awaitable:
4ca. protocol by defining the *note __await__(): f77. method.

PEP 492 also adds *note async for: ca3. statement for convenient
iteration over asynchronous iterables.

An example of a rudimentary HTTP client written using the new syntax:

     import asyncio

     async def http_get(domain):
         reader, writer = await asyncio.open_connection(domain, 80)

         writer.write(b'\r\n'.join([
             b'GET / HTTP/1.1',
             b'Host: %b' % domain.encode('latin-1'),
             b'Connection: close',
             b'', b''
         ]))

         async for line in reader:
             print('>>>', line)

         writer.close()

     loop = asyncio.get_event_loop()
     try:
         loop.run_until_complete(http_get('example.com'))
     finally:
         loop.close()

Similarly to asynchronous iteration, there is a new syntax for
asynchronous context managers.  The following script:

     import asyncio

     async def coro(name, lock):
         print('coro {}: waiting for lock'.format(name))
         async with lock:
             print('coro {}: holding the lock'.format(name))
             await asyncio.sleep(1)
             print('coro {}: releasing the lock'.format(name))

     loop = asyncio.get_event_loop()
     lock = asyncio.Lock()
     coros = asyncio.gather(coro(1, lock), coro(2, lock))
     try:
         loop.run_until_complete(coros)
     finally:
         loop.close()

will output:

     coro 2: waiting for lock
     coro 2: holding the lock
     coro 1: waiting for lock
     coro 2: releasing the lock
     coro 1: holding the lock
     coro 1: releasing the lock

Note that both *note async for: ca3. and *note async with: 185. can only
be used inside a coroutine function declared with *note async def: 7ee.

Coroutine functions are intended to be run inside a compatible event
loop, such as the *note asyncio loop: f78.

     Nota: 
     Cambiato nella versione 3.5.2: Starting with CPython 3.5.2,
     ‘__aiter__’ can directly return *note asynchronous iterators: 4c8.
     Returning an *note awaitable: 4ca. object will result in a *note
     PendingDeprecationWarning: ac8.

     See more details in the *note Asynchronous Iterators: f79.
     documentation section.

Vedi anche
..........

PEP 492(2) – Coroutines with async and await syntax

     PEP written and implemented by Yury Selivanov.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0492/

   (2) https://peps.python.org/pep-0492/


File: python.info,  Node: PEP 465 - A dedicated infix operator for matrix multiplication,  Next: PEP 448 - Additional Unpacking Generalizations,  Prev: PEP 492 - Coroutines with async and await syntax,  Up: New Features<12>

1.10.2.2 PEP 465 - A dedicated infix operator for matrix multiplication
.......................................................................

PEP 465(1) adds the ‘@’ infix operator for matrix multiplication.
Currently, no builtin Python types implement the new operator, however,
it can be implemented by defining *note __matmul__(): f7b, *note
__rmatmul__(): f7c, and *note __imatmul__(): f7d. for regular,
reflected, and in-place matrix multiplication.  The semantics of these
methods is similar to that of methods defining other infix arithmetic
operators.

Matrix multiplication is a notably common operation in many fields of
mathematics, science, engineering, and the addition of ‘@’ allows
writing cleaner code:

     S = (H @ beta - r).T @ inv(H @ V @ H.T) @ (H @ beta - r)

instead of:

     S = dot((dot(H, beta) - r).T,
             dot(inv(dot(dot(H, V), H.T)), dot(H, beta) - r))

NumPy 1.10 has support for the new operator:

     >>> import numpy

     >>> x = numpy.ones(3)
     >>> x
     array([ 1., 1., 1.])

     >>> m = numpy.eye(3)
     >>> m
     array([[ 1., 0., 0.],
            [ 0., 1., 0.],
            [ 0., 0., 1.]])

     >>> x @ m
     array([ 1., 1., 1.])

Vedi anche
..........

PEP 465(2) – A dedicated infix operator for matrix multiplication

     PEP written by Nathaniel J. Smith; implemented by Benjamin
     Peterson.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0465/

   (2) https://peps.python.org/pep-0465/


File: python.info,  Node: PEP 448 - Additional Unpacking Generalizations,  Next: PEP 461 - percent formatting support for bytes and bytearray,  Prev: PEP 465 - A dedicated infix operator for matrix multiplication,  Up: New Features<12>

1.10.2.3 PEP 448 - Additional Unpacking Generalizations
.......................................................

PEP 448(1) extends the allowed uses of the ‘*’ iterable unpacking
operator and ‘**’ dictionary unpacking operator.  It is now possible to
use an arbitrary number of unpackings in *note function calls: f7f.:

     >>> print(*[1], *[2], 3, *[4, 5])
     1 2 3 4 5

     >>> def fn(a, b, c, d):
     ...     print(a, b, c, d)
     ...

     >>> fn(**{'a': 1, 'c': 3}, **{'b': 2, 'd': 4})
     1 2 3 4

Similarly, tuple, list, set, and dictionary displays allow multiple
unpackings (see *note Expression lists: f80. and *note Dictionary
displays: f81.):

     >>> *range(4), 4
     (0, 1, 2, 3, 4)

     >>> [*range(4), 4]
     [0, 1, 2, 3, 4]

     >>> {*range(4), 4, *(5, 6, 7)}
     {0, 1, 2, 3, 4, 5, 6, 7}

     >>> {'x': 1, **{'y': 2}}
     {'x': 1, 'y': 2}

Vedi anche
..........

PEP 448(2) – Additional Unpacking Generalizations

     PEP written by Joshua Landau; implemented by Neil Girdhar, Thomas
     Wouters, and Joshua Landau.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0448/

   (2) https://peps.python.org/pep-0448/


File: python.info,  Node: PEP 461 - percent formatting support for bytes and bytearray,  Next: PEP 484 - Type Hints,  Prev: PEP 448 - Additional Unpacking Generalizations,  Up: New Features<12>

1.10.2.4 PEP 461 - percent formatting support for bytes and bytearray
.....................................................................

PEP 461(1) adds support for the ‘%’ *note interpolation operator: f83.
to *note bytes: 192. and *note bytearray: 344.

While interpolation is usually thought of as a string operation, there
are cases where interpolation on ‘bytes’ or ‘bytearrays’ makes sense,
and the work needed to make up for this missing functionality detracts
from the overall readability of the code.  This issue is particularly
important when dealing with wire format protocols, which are often a
mixture of binary and ASCII compatible text.

Examples:

     >>> b'Hello %b!' % b'World'
     b'Hello World!'

     >>> b'x=%i y=%f' % (1, 2.5)
     b'x=1 y=2.500000'

Unicode is not allowed for ‘%b’, but it is accepted by ‘%a’ (equivalent
of ‘repr(obj).encode('ascii', 'backslashreplace')’):

     >>> b'Hello %b!' % 'World'
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: %b requires bytes, or an object that implements __bytes__, not 'str'

     >>> b'price: %a' % '10€'
     b"price: '10\\u20ac'"

Note that ‘%s’ and ‘%r’ conversion types, although supported, should
only be used in codebases that need compatibility with Python 2.

Vedi anche
..........

PEP 461(2) – Adding % formatting to bytes and bytearray

     PEP written by Ethan Furman; implemented by Neil Schemenauer and
     Ethan Furman.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0461/

   (2) https://peps.python.org/pep-0461/


File: python.info,  Node: PEP 484 - Type Hints,  Next: PEP 471 - os scandir function – a better and faster directory iterator,  Prev: PEP 461 - percent formatting support for bytes and bytearray,  Up: New Features<12>

1.10.2.5 PEP 484 - Type Hints
.............................

Function annotation syntax has been a Python feature since version 3.0 (
PEP 3107(1)), however the semantics of annotations has been left
undefined.

Experience has shown that the majority of function annotation uses were
to provide type hints to function parameters and return values.  It
became evident that it would be beneficial for Python users, if the
standard library included the base definitions and tools for type
annotations.

PEP 484(2) introduces a *note provisional module: 3d1. to provide these
standard definitions and tools, along with some conventions for
situations where annotations are not available.

For example, here is a simple function whose argument and return type
are declared in the annotations:

     def greeting(name: str) -> str:
         return 'Hello ' + name

While these annotations are available at runtime through the usual *note
__annotations__: 458. attribute, 'no automatic type checking happens at
runtime'.  Instead, it is assumed that a separate off-line type checker
(e.g.  mypy(3)) will be used for on-demand source code analysis.

The type system supports unions, generic types, and a special type named
*note Any: 8bc. which is consistent with (i.e.  assignable to and from)
all types.

Vedi anche
..........

   * *note typing: 10a. module documentation

   * 
     PEP 484(4) – Type Hints

          PEP written by Guido van Rossum, Jukka Lehtosalo, and Łukasz
          Langa; implemented by Guido van Rossum.

   * 
     PEP 483(5) – The Theory of Type Hints

          PEP written by Guido van Rossum

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3107/

   (2) https://peps.python.org/pep-0484/

   (3) https://mypy-lang.org

   (4) https://peps.python.org/pep-0484/

   (5) https://peps.python.org/pep-0483/


File: python.info,  Node: PEP 471 - os scandir function – a better and faster directory iterator,  Next: PEP 475 Retry system calls failing with EINTR,  Prev: PEP 484 - Type Hints,  Up: New Features<12>

1.10.2.6 PEP 471 - os.scandir() function – a better and faster directory iterator
.................................................................................

PEP 471(1) adds a new directory iteration function, *note os.scandir():
c56, to the standard library.  Additionally, *note os.walk(): 6d1. is
now implemented using ‘scandir’, which makes it 3 to 5 times faster on
POSIX systems and 7 to 20 times faster on Windows systems.  This is
largely achieved by greatly reducing the number of calls to *note
os.stat(): 26d. required to walk a directory tree.

Additionally, ‘scandir’ returns an iterator, as opposed to returning a
list of file names, which improves memory efficiency when iterating over
very large directories.

The following example shows a simple use of *note os.scandir(): c56. to
display all the files (excluding directories) in the given 'path' that
don’t start with ‘'.'’.  The *note entry.is_file(): f86. call will
generally not make an additional system call:

     for entry in os.scandir(path):
         if not entry.name.startswith('.') and entry.is_file():
             print(entry.name)

Vedi anche
..........

PEP 471(2) – os.scandir() function – a better and faster directory iterator

     PEP written and implemented by Ben Hoyt with the help of Victor
     Stinner.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0471/

   (2) https://peps.python.org/pep-0471/


File: python.info,  Node: PEP 475 Retry system calls failing with EINTR,  Next: PEP 479 Change StopIteration handling inside generators,  Prev: PEP 471 - os scandir function – a better and faster directory iterator,  Up: New Features<12>

1.10.2.7 PEP 475: Retry system calls failing with EINTR
.......................................................

An *note errno.EINTR: f89. error code is returned whenever a system
call, that is waiting for I/O, is interrupted by a signal.  Previously,
Python would raise *note InterruptedError: f8a. in such cases.  This
meant that, when writing a Python application, the developer had two
choices:

  1. Ignore the ‘InterruptedError’.

  2. Handle the ‘InterruptedError’ and attempt to restart the
     interrupted system call at every call site.

The first option makes an application fail intermittently.  The second
option adds a large amount of boilerplate that makes the code nearly
unreadable.  Compare:

     print("Hello World")

and:

     while True:
         try:
             print("Hello World")
             break
         except InterruptedError:
             continue

PEP 475(1) implements automatic retry of system calls on ‘EINTR’.  This
removes the burden of dealing with ‘EINTR’ or *note InterruptedError:
f8a. in user code in most situations and makes Python programs,
including the standard library, more robust.  Note that the system call
is only retried if the signal handler does not raise an exception.

Below is a list of functions which are now retried when interrupted by a
signal:

   * *note open(): 316. and *note io.open(): 741.;

   * functions of the *note faulthandler: 5c. module;

   * *note os: a5. functions: *note fchdir(): f8b, *note fchmod(): 52b,
     *note fchown(): f8c, *note fdatasync(): f8d, *note fstat(): f8e,
     *note fstatvfs(): f8f, *note fsync(): f90, *note ftruncate(): f91,
     *note mkfifo(): f92, *note mknod(): f93, *note open(): f94, *note
     posix_fadvise(): f95, *note posix_fallocate(): f96, *note pread():
     d58, *note pwrite(): d5b, *note read(): f97, *note readv(): d57,
     *note sendfile(): d07, *note wait3(): f98, *note wait4(): f99,
     *note wait(): f9a, *note waitid(): f9b, *note waitpid(): f9c, *note
     write(): f9d, *note writev(): d5a.;

   * special cases: *note os.close(): d6d. and *note os.dup2(): d5c. now
     ignore *note EINTR: f89. errors; the syscall is not retried (see
     the PEP for the rationale);

   * *note select: c6. functions: *note devpoll.poll(): f9e, *note
     epoll.poll(): f9f, *note kqueue.control(): fa0, *note poll.poll():
     fa1, *note select(): fa2.;

   * methods of the *note socket: fa3. class: *note accept(): fa4, *note
     connect(): fa5. (except for non-blocking sockets), *note recv():
     fa6, *note recvfrom(): fa7, *note recvmsg(): fa8, *note send():
     fa9, *note sendall(): faa, *note sendmsg(): 6a2, *note sendto():
     fab.;

   * *note signal.sigtimedwait(): fac. and *note signal.sigwaitinfo():
     fad.;

   * *note time.sleep(): 8ad.

Vedi anche
..........

PEP 475(2) – Retry system calls failing with EINTR

     PEP and implementation written by Charles-François Natali and
     Victor Stinner, with the help of Antoine Pitrou (the French
     connection).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0475/

   (2) https://peps.python.org/pep-0475/


File: python.info,  Node: PEP 479 Change StopIteration handling inside generators,  Next: PEP 485 A function for testing approximate equality,  Prev: PEP 475 Retry system calls failing with EINTR,  Up: New Features<12>

1.10.2.8 PEP 479: Change StopIteration handling inside generators
.................................................................

The interaction of generators and *note StopIteration: df7. in Python
3.4 and earlier was sometimes surprising, and could conceal obscure
bugs.  Previously, ‘StopIteration’ raised accidentally inside a
generator function was interpreted as the end of the iteration by the
loop construct driving the generator.

PEP 479(1) changes the behavior of generators: when a ‘StopIteration’
exception is raised inside a generator, it is replaced with a *note
RuntimeError: 244. before it exits the generator frame.  The main goal
of this change is to ease debugging in the situation where an unguarded
*note next(): 9da. call raises ‘StopIteration’ and causes the iteration
controlled by the generator to terminate silently.  This is particularly
pernicious in combination with the ‘yield from’ construct.

This is a backwards incompatible change, so to enable the new behavior,
a *note __future__: faf. import is necessary:

     >>> from __future__ import generator_stop

     >>> def gen():
     ...     next(iter([]))
     ...     yield
     ...
     >>> next(gen())
     Traceback (most recent call last):
       File "<stdin>", line 2, in gen
     StopIteration

     The above exception was the direct cause of the following exception:

     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     RuntimeError: generator raised StopIteration

Without a ‘__future__’ import, a *note PendingDeprecationWarning: ac8.
will be raised whenever a *note StopIteration: df7. exception is raised
inside a generator.

Vedi anche
..........

PEP 479(2) – Change StopIteration handling inside generators

     PEP written by Chris Angelico and Guido van Rossum.  Implemented by
     Chris Angelico, Yury Selivanov and Nick Coghlan.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0479/

   (2) https://peps.python.org/pep-0479/


File: python.info,  Node: PEP 485 A function for testing approximate equality,  Next: PEP 486 Make the Python Launcher aware of virtual environments,  Prev: PEP 479 Change StopIteration handling inside generators,  Up: New Features<12>

1.10.2.9 PEP 485: A function for testing approximate equality
.............................................................

PEP 485(1) adds the *note math.isclose(): fb2. and *note
cmath.isclose(): fb3. functions which tell whether two values are
approximately equal or «close» to each other.  Whether or not two values
are considered close is determined according to given absolute and
relative tolerances.  Relative tolerance is the maximum allowed
difference between ‘isclose’ arguments, relative to the larger absolute
value:

     >>> import math
     >>> a = 5.0
     >>> b = 4.99998
     >>> math.isclose(a, b, rel_tol=1e-5)
     True
     >>> math.isclose(a, b, rel_tol=1e-6)
     False

It is also possible to compare two values using absolute tolerance,
which must be a non-negative value:

     >>> import math
     >>> a = 5.0
     >>> b = 4.99998
     >>> math.isclose(a, b, abs_tol=0.00003)
     True
     >>> math.isclose(a, b, abs_tol=0.00001)
     False

Vedi anche
..........

PEP 485(2) – A function for testing approximate equality

     PEP written by Christopher Barker; implemented by Chris Barker and
     Tal Einat.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0485/

   (2) https://peps.python.org/pep-0485/


File: python.info,  Node: PEP 486 Make the Python Launcher aware of virtual environments,  Next: PEP 488 Elimination of PYO files,  Prev: PEP 485 A function for testing approximate equality,  Up: New Features<12>

1.10.2.10 PEP 486: Make the Python Launcher aware of virtual environments
.........................................................................

PEP 486(1) makes the Windows launcher (see PEP 397(2)) aware of an
active virtual environment.  When the default interpreter would be used
and the ‘VIRTUAL_ENV’ environment variable is set, the interpreter in
the virtual environment will be used.

Vedi anche
..........

PEP 486(3) – Make the Python Launcher aware of virtual environments

     PEP written and implemented by Paul Moore.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0486/

   (2) https://peps.python.org/pep-0397/

   (3) https://peps.python.org/pep-0486/


File: python.info,  Node: PEP 488 Elimination of PYO files,  Next: PEP 489 Multi-phase extension module initialization,  Prev: PEP 486 Make the Python Launcher aware of virtual environments,  Up: New Features<12>

1.10.2.11 PEP 488: Elimination of PYO files
...........................................

PEP 488(1) does away with the concept of ‘.pyo’ files.  This means that
‘.pyc’ files represent both unoptimized and optimized bytecode.  To
prevent the need to constantly regenerate bytecode files, ‘.pyc’ files
now have an optional ‘opt-’ tag in their name when the bytecode is
optimized.  This has the side-effect of no more bytecode file name
clashes when running under either *note -O: 18c. or *note -OO: fb7.
Consequently, bytecode files generated from *note -O: 18c, and *note
-OO: fb7. may now exist simultaneously.  *note
importlib.util.cache_from_source(): 353. has an updated API to help with
this change.

Vedi anche
..........

PEP 488(2) – Elimination of PYO files

     PEP written and implemented by Brett Cannon.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0488/

   (2) https://peps.python.org/pep-0488/


File: python.info,  Node: PEP 489 Multi-phase extension module initialization,  Prev: PEP 488 Elimination of PYO files,  Up: New Features<12>

1.10.2.12 PEP 489: Multi-phase extension module initialization
..............................................................

PEP 489(1) updates extension module initialization to take advantage of
the two step module loading mechanism introduced by PEP 451(2) in Python
3.4.

This change brings the import semantics of extension modules that opt-in
to using the new mechanism much closer to those of Python source and
bytecode modules, including the ability to use any valid identifier as a
module name, rather than being restricted to ASCII.

Vedi anche
..........

PEP 489(3) – Multi-phase extension module initialization

     PEP written by Petr Viktorin, Stefan Behnel, and Nick Coghlan;
     implemented by Petr Viktorin.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0489/

   (2) https://peps.python.org/pep-0451/

   (3) https://peps.python.org/pep-0489/


File: python.info,  Node: Other Language Changes<8>,  Next: New Modules<8>,  Prev: New Features<12>,  Up: What’s New In Python 3 5

1.10.3 Other Language Changes
-----------------------------

Some smaller changes made to the core Python language are:

   * Added the ‘"namereplace"’ error handlers.  The ‘"backslashreplace"’
     error handlers now work with decoding and translating.
     (Contributed by Serhiy Storchaka in bpo-19676(1) and bpo-22286(2).)

   * The *note -b: 7fa. option now affects comparisons of *note bytes:
     192. with *note int: 19b.  (Contributed by Serhiy Storchaka in
     bpo-23681(3).)

   * New Kazakh ‘kz1048’ and Tajik ‘koi8_t’ *note codecs: fba.
     (Contributed by Serhiy Storchaka in bpo-22682(4) and bpo-22681(5).)

   * Property docstrings are now writable.  This is especially useful
     for *note collections.namedtuple(): 4e1. docstrings.  (Contributed
     by Berker Peksag in bpo-24064(6).)

   * Circular imports involving relative imports are now supported.
     (Contributed by Brett Cannon and Antoine Pitrou in bpo-17636(7).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19676

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22286

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23681

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22682

   (5) https://bugs.python.org/issue?@action=redirect&bpo=22681

   (6) https://bugs.python.org/issue?@action=redirect&bpo=24064

   (7) https://bugs.python.org/issue?@action=redirect&bpo=17636


File: python.info,  Node: New Modules<8>,  Next: Improved Modules<8>,  Prev: Other Language Changes<8>,  Up: What’s New In Python 3 5

1.10.4 New Modules
------------------

* Menu:

* typing: typing<11>.
* zipapp: zipapp<2>.


File: python.info,  Node: typing<11>,  Next: zipapp<2>,  Up: New Modules<8>

1.10.4.1 typing
...............

The new *note typing: 10a. *note provisional: 3d1. module provides
standard definitions and tools for function type annotations.  See *note
Type Hints: f64. for more information.


File: python.info,  Node: zipapp<2>,  Prev: typing<11>,  Up: New Modules<8>

1.10.4.2 zipapp
...............

The new *note zipapp: 136. module (specified in PEP 441(1)) provides an
API and command line tool for creating executable Python Zip
Applications, which were introduced in Python 2.6 in bpo-1739468(2), but
which were not well publicized, either at the time or since.

With the new module, bundling your application is as simple as putting
all the files, including a ‘__main__.py’ file, into a directory ‘myapp’
and running:

     $ python -m zipapp myapp
     $ python myapp.pyz

The module implementation has been contributed by Paul Moore in
bpo-23491(3).

Vedi anche
..........

PEP 441(4) – Improving Python ZIP Application Support

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0441/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1739468

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23491

   (4) https://peps.python.org/pep-0441/


File: python.info,  Node: Improved Modules<8>,  Next: Other module-level changes,  Prev: New Modules<8>,  Up: What’s New In Python 3 5

1.10.5 Improved Modules
-----------------------

* Menu:

* argparse: argparse<6>.
* asyncio: asyncio<13>.
* bz2::
* cgi::
* cmath: cmath<2>.
* code::
* collections: collections<5>.
* collections.abc: collections abc<3>.
* compileall: compileall<4>.
* concurrent.futures: concurrent futures<6>.
* configparser: configparser<5>.
* contextlib: contextlib<5>.
* csv: csv<3>.
* curses: curses<5>.
* dbm: dbm<5>.
* difflib: difflib<3>.
* distutils: distutils<7>.
* doctest: doctest<3>.
* email: email<4>.
* enum: enum<8>.
* faulthandler: faulthandler<4>.
* functools: functools<5>.
* glob: glob<3>.
* gzip: gzip<4>.
* heapq: heapq<2>.
* http: http<3>.
* http.client: http client<3>.
* idlelib and IDLE: idlelib and IDLE<3>.
* imaplib: imaplib<3>.
* imghdr::
* importlib: importlib<8>.
* inspect: inspect<8>.
* io: io<7>.
* ipaddress: ipaddress<4>.
* json: json<3>.
* linecache: linecache<3>.
* locale: locale<6>.
* logging: logging<5>.
* lzma::
* math: math<8>.
* multiprocessing: multiprocessing<7>.
* operator: operator<3>.
* os: os<11>.
* pathlib: pathlib<13>.
* pickle: pickle<4>.
* poplib: poplib<2>.
* re: re<8>.
* readline: readline<2>.
* selectors::
* shutil: shutil<5>.
* signal: signal<3>.
* smtpd: smtpd<2>.
* smtplib: smtplib<2>.
* sndhdr::
* socket: socket<9>.
* ssl: ssl<10>.
* sqlite3: sqlite3<9>.
* subprocess: subprocess<4>.
* sys: sys<11>.
* sysconfig: sysconfig<3>.
* tarfile: tarfile<7>.
* threading: threading<7>.
* time: time<7>.
* timeit: timeit<2>.
* tkinter: tkinter<9>.
* traceback: traceback<5>.
* types: types<6>.
* unicodedata: unicodedata<9>.
* unittest: unittest<9>.
* unittest.mock: unittest mock<3>.
* urllib: urllib<4>.
* wsgiref::
* xmlrpc: xmlrpc<2>.
* xml.sax: xml sax.
* zipfile: zipfile<5>.


File: python.info,  Node: argparse<6>,  Next: asyncio<13>,  Up: Improved Modules<8>

1.10.5.1 argparse
.................

The *note ArgumentParser: 1bd. class now allows disabling *note
abbreviated usage: fc0. of long options by setting *note allow_abbrev:
fc1. to ‘False’.  (Contributed by Jonathan Paugh, Steven Bethard, paul
j3 and Daniel Eriksson in bpo-14910(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14910


File: python.info,  Node: asyncio<13>,  Next: bz2,  Prev: argparse<6>,  Up: Improved Modules<8>

1.10.5.2 asyncio
................

Since the *note asyncio: b. module is *note provisional: 3d1, all
changes introduced in Python 3.5 have also been backported to Python
3.4.x.

Notable changes in the *note asyncio: b. module since Python 3.4.0:

   * New debugging APIs: *note loop.set_debug(): fc3. and *note
     loop.get_debug(): fc4. methods.  (Contributed by Victor Stinner.)

   * The proactor event loop now supports SSL. (Contributed by Antoine
     Pitrou and Victor Stinner in bpo-22560(1).)

   * A new *note loop.is_closed(): fc5. method to check if the event
     loop is closed.  (Contributed by Victor Stinner in bpo-21326(2).)

   * A new *note loop.create_task(): 1ca. to conveniently create and
     schedule a new *note Task: 1c7. for a coroutine.  The ‘create_task’
     method is also used by all asyncio functions that wrap coroutines
     into tasks, such as *note asyncio.wait(): 6a8, *note
     asyncio.gather(): 814, etc.  (Contributed by Victor Stinner.)

   * A new *note transport.get_write_buffer_limits(): fc6. method to
     inquire for 'high-' and 'low-' water limits of the flow control.
     (Contributed by Victor Stinner.)

   * The ‘async()’ function is deprecated in favor of *note
     ensure_future(): e73.  (Contributed by Yury Selivanov.)

   * New *note loop.set_task_factory(): 1c8. and *note
     loop.get_task_factory(): fc7. methods to customize the task factory
     that *note loop.create_task(): 1ca. method uses.  (Contributed by
     Yury Selivanov.)

   * New *note Queue.join(): fc8. and *note Queue.task_done(): fc9.
     queue methods.  (Contributed by Victor Stinner.)

   * The ‘JoinableQueue’ class was removed, in favor of the *note
     asyncio.Queue: c6c. class.  (Contributed by Victor Stinner.)

Updates in 3.5.1:

   * The *note ensure_future(): e73. function and all functions that use
     it, such as *note loop.run_until_complete(): e74, now accept all
     kinds of *note awaitable objects: 4ca.  (Contributed by Yury
     Selivanov.)

   * New *note run_coroutine_threadsafe(): a84. function to submit
     coroutines to event loops from other threads.  (Contributed by
     Vincent Michel.)

   * New *note Transport.is_closing(): e75. method to check if the
     transport is closing or closed.  (Contributed by Yury Selivanov.)

   * The *note loop.create_server(): d0b. method can now accept a list
     of hosts.  (Contributed by Yann Sionneau.)

Updates in 3.5.2:

   * New *note loop.create_future(): e76. method to create Future
     objects.  This allows alternative event loop implementations, such
     as uvloop(3), to provide a faster *note asyncio.Future: dc8.
     implementation.  (Contributed by Yury Selivanov.)

   * New *note loop.get_exception_handler(): e77. method to get the
     current exception handler.  (Contributed by Yury Selivanov.)

   * New *note StreamReader.readuntil(): 4d1. method to read data from
     the stream until a separator bytes sequence appears.  (Contributed
     by Mark Korenberg.)

   * The *note loop.create_connection(): 819. and *note
     loop.create_server(): d0b. methods are optimized to avoid calling
     the system ‘getaddrinfo’ function if the address is already
     resolved.  (Contributed by A. Jesse Jiryu Davis.)

   * The *note loop.sock_connect(sock, address): fca. no longer requires
     the 'address' to be resolved prior to the call.  (Contributed by A.
     Jesse Jiryu Davis.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22560

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21326

   (3) https://github.com/MagicStack/uvloop


File: python.info,  Node: bz2,  Next: cgi,  Prev: asyncio<13>,  Up: Improved Modules<8>

1.10.5.3 bz2
............

The *note BZ2Decompressor.decompress: fcc. method now accepts an
optional 'max_length' argument to limit the maximum size of decompressed
data.  (Contributed by Nikolaus Rath in bpo-15955(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15955


File: python.info,  Node: cgi,  Next: cmath<2>,  Prev: bz2,  Up: Improved Modules<8>

1.10.5.4 cgi
............

The ‘FieldStorage’ class now supports the *note context manager: 1e1.
protocol.  (Contributed by Berker Peksag in bpo-20289(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20289


File: python.info,  Node: cmath<2>,  Next: code,  Prev: cgi,  Up: Improved Modules<8>

1.10.5.5 cmath
..............

A new function *note isclose(): fb3. provides a way to test for
approximate equality.  (Contributed by Chris Barker and Tal Einat in
bpo-24270(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24270


File: python.info,  Node: code,  Next: collections<5>,  Prev: cmath<2>,  Up: Improved Modules<8>

1.10.5.6 code
.............

The *note InteractiveInterpreter.showtraceback(): fd0. method now prints
the full chained traceback, just like the interactive interpreter.
(Contributed by Claudiu Popa in bpo-17442(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17442


File: python.info,  Node: collections<5>,  Next: collections abc<3>,  Prev: code,  Up: Improved Modules<8>

1.10.5.7 collections
....................

The *note OrderedDict: 7f4. class is now implemented in C, which makes
it 4 to 100 times faster.  (Contributed by Eric Snow in bpo-16991(1).)

‘OrderedDict.items()’, ‘OrderedDict.keys()’, and ‘OrderedDict.values()’
views now support *note reversed(): a67. iteration.  (Contributed by
Serhiy Storchaka in bpo-19505(2).)

The *note deque: 7f5. class now defines *note index(): fd2, *note
insert(): fd3, and *note copy(): fd4, and supports the ‘+’ and ‘*’
operators.  This allows deques to be recognized as a *note
MutableSequence: 4c0. and improves their substitutability for lists.
(Contributed by Raymond Hettinger in bpo-23704(3).)

Docstrings produced by *note namedtuple(): 4e1. can now be updated:

     Point = namedtuple('Point', ['x', 'y'])
     Point.__doc__ += ': Cartesian coordinate'
     Point.x.__doc__ = 'abscissa'
     Point.y.__doc__ = 'ordinate'

(Contributed by Berker Peksag in bpo-24064(4).)

The *note UserString: fd5. class now implements the *note
__getnewargs__(): fd6, *note __rmod__(): fd7, *note casefold(): fd8,
*note format_map(): fd9, *note isprintable(): fda, and *note
maketrans(): fdb. methods to match the corresponding methods of *note
str: 169.  (Contributed by Joe Jevnik in bpo-22189(5).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16991

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19505

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23704

   (4) https://bugs.python.org/issue?@action=redirect&bpo=24064

   (5) https://bugs.python.org/issue?@action=redirect&bpo=22189


File: python.info,  Node: collections abc<3>,  Next: compileall<4>,  Prev: collections<5>,  Up: Improved Modules<8>

1.10.5.8 collections.abc
........................

The ‘Sequence.index()’ method now accepts 'start' and 'stop' arguments
to match the corresponding methods of *note tuple: 614, *note list: 24d,
etc.  (Contributed by Devin Jeanpierre in bpo-23086(1).)

A new *note Generator: fdd. abstract base class.  (Contributed by Stefan
Behnel in bpo-24018(2).)

New *note Awaitable: fde, *note Coroutine: fdf, *note AsyncIterator:
fe0, and *note AsyncIterable: fe1. abstract base classes.  (Contributed
by Yury Selivanov in bpo-24184(3).)

For earlier Python versions, a backport of the new ABCs is available in
an external PyPI package(4).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23086

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24018

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24184

   (4) https://pypi.org/project/backports_abc/


File: python.info,  Node: compileall<4>,  Next: concurrent futures<6>,  Prev: collections abc<3>,  Up: Improved Modules<8>

1.10.5.9 compileall
...................

A new *note compileall: 21. option, ‘-j N’, allows running 'N' workers
simultaneously to perform parallel bytecode compilation.  The *note
compile_dir(): d1d. function has a corresponding ‘workers’ parameter.
(Contributed by Claudiu Popa in bpo-16104(1).)

Another new option, ‘-r’, allows controlling the maximum recursion level
for subdirectories.  (Contributed by Claudiu Popa in bpo-19628(2).)

The ‘-q’ command line option can now be specified more than once, in
which case all output, including errors, will be suppressed.  The
corresponding ‘quiet’ parameter in *note compile_dir(): d1d, *note
compile_file(): fe3, and *note compile_path(): fe4. can now accept an
integer value indicating the level of output suppression.  (Contributed
by Thomas Kluyver in bpo-21338(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16104

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19628

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21338


File: python.info,  Node: concurrent futures<6>,  Next: configparser<5>,  Prev: compileall<4>,  Up: Improved Modules<8>

1.10.5.10 concurrent.futures
............................

The *note Executor.map(): 1dc. method now accepts a 'chunksize' argument
to allow batching of tasks to improve performance when *note
ProcessPoolExecutor(): 1d6. is used.  (Contributed by Dan O’Reilly in
bpo-11271(1).)

The number of workers in the *note ThreadPoolExecutor: 94a. constructor
is optional now.  The default value is 5 times the number of CPUs.
(Contributed by Claudiu Popa in bpo-21527(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11271

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21527


File: python.info,  Node: configparser<5>,  Next: contextlib<5>,  Prev: concurrent futures<6>,  Up: Improved Modules<8>

1.10.5.11 configparser
......................

*note configparser: 26. now provides a way to customize the conversion
of values by specifying a dictionary of converters in the *note
ConfigParser: 4df. constructor, or by defining them as methods in
‘ConfigParser’ subclasses.  Converters defined in a parser instance are
inherited by its section proxies.

Example:

     >>> import configparser
     >>> conv = {}
     >>> conv['list'] = lambda v: [e.strip() for e in v.split() if e.strip()]
     >>> cfg = configparser.ConfigParser(converters=conv)
     >>> cfg.read_string("""
     ... [s]
     ... list = a b c d e f g
     ... """)
     >>> cfg.get('s', 'list')
     'a b c d e f g'
     >>> cfg.getlist('s', 'list')
     ['a', 'b', 'c', 'd', 'e', 'f', 'g']
     >>> section = cfg['s']
     >>> section.getlist('list')
     ['a', 'b', 'c', 'd', 'e', 'f', 'g']

(Contributed by Łukasz Langa in bpo-18159(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18159


File: python.info,  Node: contextlib<5>,  Next: csv<3>,  Prev: configparser<5>,  Up: Improved Modules<8>

1.10.5.12 contextlib
....................

The new *note redirect_stderr(): fe8. *note context manager: 1e1.
(similar to *note redirect_stdout(): fe9.) makes it easier for utility
scripts to handle inflexible APIs that write their output to *note
sys.stderr: b35. and don’t provide any options to redirect it:

     >>> import contextlib, io, logging
     >>> f = io.StringIO()
     >>> with contextlib.redirect_stderr(f):
     ...     logging.warning('warning')
     ...
     >>> f.getvalue()
     'WARNING:root:warning\n'

(Contributed by Berker Peksag in bpo-22389(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22389


File: python.info,  Node: csv<3>,  Next: curses<5>,  Prev: contextlib<5>,  Up: Improved Modules<8>

1.10.5.13 csv
.............

The *note writerow(): feb. method now supports arbitrary iterables, not
just sequences.  (Contributed by Serhiy Storchaka in bpo-23171(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23171


File: python.info,  Node: curses<5>,  Next: dbm<5>,  Prev: csv<3>,  Up: Improved Modules<8>

1.10.5.14 curses
................

The new *note update_lines_cols(): fed. function updates the *note
LINES: fee. and *note COLS: fef. module variables.  This is useful for
detecting manual screen resizing.  (Contributed by Arnon Yaari in
bpo-4254(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4254


File: python.info,  Node: dbm<5>,  Next: difflib<3>,  Prev: curses<5>,  Up: Improved Modules<8>

1.10.5.15 dbm
.............

*note dumb.open: c8f. always creates a new database when the flag has
the value ‘"n"’.  (Contributed by Claudiu Popa in bpo-18039(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18039


File: python.info,  Node: difflib<3>,  Next: distutils<7>,  Prev: dbm<5>,  Up: Improved Modules<8>

1.10.5.16 difflib
.................

The charset of HTML documents generated by *note HtmlDiff.make_file():
ff2. can now be customized by using a new 'charset' keyword-only
argument.  The default charset of HTML document changed from
‘"ISO-8859-1"’ to ‘"utf-8"’.  (Contributed by Berker Peksag in
bpo-2052(1).)

The *note diff_bytes(): ff3. function can now compare lists of byte
strings.  This fixes a regression from Python 2.  (Contributed by Terry
J. Reedy and Greg Ward in bpo-17445(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=2052

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17445


File: python.info,  Node: distutils<7>,  Next: doctest<3>,  Prev: difflib<3>,  Up: Improved Modules<8>

1.10.5.17 distutils
...................

Both the ‘build’ and ‘build_ext’ commands now accept a ‘-j’ option to
enable parallel building of extension modules.  (Contributed by Antoine
Pitrou in bpo-5309(1).)

The ‘distutils’ module now supports ‘xz’ compression, and can be enabled
by passing ‘xztar’ as an argument to ‘bdist --format’.  (Contributed by
Serhiy Storchaka in bpo-16314(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5309

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16314


File: python.info,  Node: doctest<3>,  Next: email<4>,  Prev: distutils<7>,  Up: Improved Modules<8>

1.10.5.18 doctest
.................

The *note DocTestSuite(): ff6. function returns an empty *note
unittest.TestSuite: ff7. if 'module' contains no docstrings, instead of
raising *note ValueError: 2ec.  (Contributed by Glenn Jones in
bpo-15916(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15916


File: python.info,  Node: email<4>,  Next: enum<8>,  Prev: doctest<3>,  Up: Improved Modules<8>

1.10.5.19 email
...............

A new policy option *note Policy.mangle_from_: ff9. controls whether or
not lines that start with ‘"From "’ in email bodies are prefixed with a
‘">"’ character by generators.  The default is ‘True’ for *note
compat32: e99. and ‘False’ for all other policies.  (Contributed by
Milan Oberkirch in bpo-20098(1).)

A new *note Message.get_content_disposition(): ffa. method provides easy
access to a canonical value for the ‘Content-Disposition’ header.
(Contributed by Abhilash Raj in bpo-21083(2).)

A new policy option *note EmailPolicy.utf8: ffb. can be set to ‘True’ to
encode email headers using the UTF-8 charset instead of using encoded
words.  This allows ‘Messages’ to be formatted according to RFC 6532(3)
and used with an SMTP server that supports the RFC 6531(4) ‘SMTPUTF8’
extension.  (Contributed by R. David Murray in bpo-24211(5).)

The *note mime.text.MIMEText: ffc. constructor now accepts a *note
charset.Charset: ffd. instance.  (Contributed by Claude Paroz and Berker
Peksag in bpo-16324(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20098

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21083

   (3) https://datatracker.ietf.org/doc/html/rfc6532.html

   (4) https://datatracker.ietf.org/doc/html/rfc6531.html

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24211

   (6) https://bugs.python.org/issue?@action=redirect&bpo=16324


File: python.info,  Node: enum<8>,  Next: faulthandler<4>,  Prev: email<4>,  Up: Improved Modules<8>

1.10.5.20 enum
..............

The *note Enum: 843. callable has a new parameter 'start' to specify the
initial number of enum values if only 'names' are provided:

     >>> Animal = enum.Enum('Animal', 'cat dog', start=10)
     >>> Animal.cat
     <Animal.cat: 10>
     >>> Animal.dog
     <Animal.dog: 11>

(Contributed by Ethan Furman in bpo-21706(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21706


File: python.info,  Node: faulthandler<4>,  Next: functools<5>,  Prev: enum<8>,  Up: Improved Modules<8>

1.10.5.21 faulthandler
......................

The *note enable(): 20f, *note register(): 1000, *note dump_traceback():
1001. and *note dump_traceback_later(): 1002. functions now accept file
descriptors in addition to file-like objects.  (Contributed by Wei Wu in
bpo-23566(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23566


File: python.info,  Node: functools<5>,  Next: glob<3>,  Prev: faulthandler<4>,  Up: Improved Modules<8>

1.10.5.22 functools
...................

Most of the *note lru_cache(): be4. machinery is now implemented in C,
making it significantly faster.  (Contributed by Matt Joiner, Alexey
Kachayev, and Serhiy Storchaka in bpo-14373(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14373


File: python.info,  Node: glob<3>,  Next: gzip<4>,  Prev: functools<5>,  Up: Improved Modules<8>

1.10.5.23 glob
..............

The *note iglob(): a0a. and *note glob(): 5a0. functions now support
recursive search in subdirectories, using the ‘"**"’ pattern.
(Contributed by Serhiy Storchaka in bpo-13968(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13968


File: python.info,  Node: gzip<4>,  Next: heapq<2>,  Prev: glob<3>,  Up: Improved Modules<8>

1.10.5.24 gzip
..............

The 'mode' argument of the *note GzipFile: 65c. constructor now accepts
‘"x"’ to request exclusive creation.  (Contributed by Tim Heaney in
bpo-19222(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19222


File: python.info,  Node: heapq<2>,  Next: http<3>,  Prev: gzip<4>,  Up: Improved Modules<8>

1.10.5.25 heapq
...............

Element comparison in *note merge(): 1007. can now be customized by
passing a *note key function: 1008. in a new optional 'key' keyword
argument, and a new optional 'reverse' keyword argument can be used to
reverse element comparison:

     >>> import heapq
     >>> a = ['9', '777', '55555']
     >>> b = ['88', '6666']
     >>> list(heapq.merge(a, b, key=len))
     ['9', '88', '777', '6666', '55555']
     >>> list(heapq.merge(reversed(a), reversed(b), key=len, reverse=True))
     ['55555', '6666', '777', '88', '9']

(Contributed by Raymond Hettinger in bpo-13742(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13742


File: python.info,  Node: http<3>,  Next: http client<3>,  Prev: heapq<2>,  Up: Improved Modules<8>

1.10.5.26 http
..............

A new *note HTTPStatus: afe. enum that defines a set of HTTP status
codes, reason phrases and long descriptions written in English.
(Contributed by Demian Brecht in bpo-21793(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21793


File: python.info,  Node: http client<3>,  Next: idlelib and IDLE<3>,  Prev: http<3>,  Up: Improved Modules<8>

1.10.5.27 http.client
.....................

*note HTTPConnection.getresponse(): 100b. now raises a *note
RemoteDisconnected: 100c. exception when a remote server connection is
closed unexpectedly.  Additionally, if a *note ConnectionError: 100d.
(of which ‘RemoteDisconnected’ is a subclass) is raised, the client
socket is now closed automatically, and will reconnect on the next
request:

     import http.client
     conn = http.client.HTTPConnection('www.python.org')
     for retries in range(3):
         try:
             conn.request('GET', '/')
             resp = conn.getresponse()
         except http.client.RemoteDisconnected:
             pass

(Contributed by Martin Panter in bpo-3566(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=3566


File: python.info,  Node: idlelib and IDLE<3>,  Next: imaplib<3>,  Prev: http client<3>,  Up: Improved Modules<8>

1.10.5.28 idlelib and IDLE
..........................

Since idlelib implements the IDLE shell and editor and is not intended
for import by other programs, it gets improvements with every release.
See ‘Lib/idlelib/NEWS.txt’ for a cumulative list of changes since 3.4.0,
as well as changes made in future 3.5.x releases.  This file is also
available from the IDLE Help ‣ About IDLE dialog.


File: python.info,  Node: imaplib<3>,  Next: imghdr,  Prev: idlelib and IDLE<3>,  Up: Improved Modules<8>

1.10.5.29 imaplib
.................

The *note IMAP4: b01. class now supports the *note context manager: 1e1.
protocol.  When used in a *note with: 186. statement, the IMAP4 ‘LOGOUT’
command will be called automatically at the end of the block.
(Contributed by Tarek Ziadé and Serhiy Storchaka in bpo-4972(1).)

The *note imaplib: 78. module now supports RFC 5161(2) (ENABLE
Extension) and RFC 6855(3) (UTF-8 Support) via the *note IMAP4.enable():
1010. method.  A new *note IMAP4.utf8_enabled: 1011. attribute tracks
whether or not RFC 6855(4) support is enabled.  (Contributed by Milan
Oberkirch, R. David Murray, and Maciej Szulik in bpo-21800(5).)

The *note imaplib: 78. module now automatically encodes non-ASCII string
usernames and passwords using UTF-8, as recommended by the RFCs.
(Contributed by Milan Oberkirch in bpo-21800(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4972

   (2) https://datatracker.ietf.org/doc/html/rfc5161.html

   (3) https://datatracker.ietf.org/doc/html/rfc6855.html

   (4) https://datatracker.ietf.org/doc/html/rfc6855.html

   (5) https://bugs.python.org/issue?@action=redirect&bpo=21800

   (6) https://bugs.python.org/issue?@action=redirect&bpo=21800


File: python.info,  Node: imghdr,  Next: importlib<8>,  Prev: imaplib<3>,  Up: Improved Modules<8>

1.10.5.30 imghdr
................

The ‘what()’ function now recognizes the OpenEXR(1) format (contributed
by Martin Vignali and Claudiu Popa in bpo-20295(2)), and the WebP(3)
format (contributed by Fabrice Aneche and Claudiu Popa in bpo-20197(4).)

   ---------- Footnotes ----------

   (1) https://www.openexr.com

   (2) https://bugs.python.org/issue?@action=redirect&bpo=20295

   (3) https://en.wikipedia.org/wiki/WebP

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20197


File: python.info,  Node: importlib<8>,  Next: inspect<8>,  Prev: imghdr,  Up: Improved Modules<8>

1.10.5.31 importlib
...................

The *note util.LazyLoader: ead. class allows for lazy loading of modules
in applications where startup time is important.  (Contributed by Brett
Cannon in bpo-17621(1).)

The *note abc.InspectLoader.source_to_code(): 1014. method is now a
static method.  This makes it easier to initialize a module object with
code compiled from a string by running ‘exec(code, module.__dict__)’.
(Contributed by Brett Cannon in bpo-21156(2).)

The new *note util.module_from_spec(): 1015. function is now the
preferred way to create a new module.  As opposed to creating a *note
types.ModuleType: 1016. instance directly, this new function will set
the various import-controlled attributes based on the passed-in spec
object.  (Contributed by Brett Cannon in bpo-20383(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17621

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21156

   (3) https://bugs.python.org/issue?@action=redirect&bpo=20383


File: python.info,  Node: inspect<8>,  Next: io<7>,  Prev: importlib<8>,  Up: Improved Modules<8>

1.10.5.32 inspect
.................

Both the *note Signature: 4e4. and *note Parameter: 4e5. classes are now
picklable and hashable.  (Contributed by Yury Selivanov in bpo-20726(1)
and bpo-20334(2).)

A new *note BoundArguments.apply_defaults(): 1018. method provides a way
to set default values for missing arguments:

     >>> def foo(a, b='ham', *args): pass
     >>> ba = inspect.signature(foo).bind('spam')
     >>> ba.apply_defaults()
     >>> ba.arguments
     OrderedDict([('a', 'spam'), ('b', 'ham'), ('args', ())])

(Contributed by Yury Selivanov in bpo-24190(3).)

A new class method *note Signature.from_callable(): 943. makes
subclassing of *note Signature: 4e4. easier.  (Contributed by Yury
Selivanov and Eric Snow in bpo-17373(4).)

The *note signature(): 22f. function now accepts a 'follow_wrapped'
optional keyword argument, which, when set to ‘False’, disables
automatic following of ‘__wrapped__’ links.  (Contributed by Yury
Selivanov in bpo-20691(5).)

A set of new functions to inspect *note coroutine functions: f75. and
*note coroutine objects: 6ba. has been added: *note iscoroutine(): 1019,
*note iscoroutinefunction(): 30d, *note isawaitable(): 101a, *note
getcoroutinelocals(): 101b, and *note getcoroutinestate(): 101c.
(Contributed by Yury Selivanov in bpo-24017(6) and bpo-24400(7).)

The *note stack(): 863, *note trace(): 864, *note getouterframes(): 861,
and *note getinnerframes(): 862. functions now return a list of named
tuples.  (Contributed by Daniel Shahaf in bpo-16808(8).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20726

   (2) https://bugs.python.org/issue?@action=redirect&bpo=20334

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24190

   (4) https://bugs.python.org/issue?@action=redirect&bpo=17373

   (5) https://bugs.python.org/issue?@action=redirect&bpo=20691

   (6) https://bugs.python.org/issue?@action=redirect&bpo=24017

   (7) https://bugs.python.org/issue?@action=redirect&bpo=24400

   (8) https://bugs.python.org/issue?@action=redirect&bpo=16808


File: python.info,  Node: io<7>,  Next: ipaddress<4>,  Prev: inspect<8>,  Up: Improved Modules<8>

1.10.5.33 io
............

A new *note BufferedIOBase.readinto1(): 101e. method, that uses at most
one call to the underlying raw stream’s *note RawIOBase.read(): 101f. or
*note RawIOBase.readinto(): 1020. methods.  (Contributed by Nikolaus
Rath in bpo-20578(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20578


File: python.info,  Node: ipaddress<4>,  Next: json<3>,  Prev: io<7>,  Up: Improved Modules<8>

1.10.5.34 ipaddress
...................

Both the *note IPv4Network: 50f. and *note IPv6Network: 510. classes now
accept an ‘(address, netmask)’ tuple argument, so as to easily construct
network objects from existing addresses:

     >>> import ipaddress
     >>> ipaddress.IPv4Network(('127.0.0.0', 8))
     IPv4Network('127.0.0.0/8')
     >>> ipaddress.IPv4Network(('127.0.0.0', '255.0.0.0'))
     IPv4Network('127.0.0.0/8')

(Contributed by Peter Moody and Antoine Pitrou in bpo-16531(1).)

A new *note reverse_pointer: 1022. attribute for the *note IPv4Address:
50d. and *note IPv6Address: 50e. classes returns the name of the reverse
DNS PTR record:

     >>> import ipaddress
     >>> addr = ipaddress.IPv4Address('127.0.0.1')
     >>> addr.reverse_pointer
     '1.0.0.127.in-addr.arpa'
     >>> addr6 = ipaddress.IPv6Address('::1')
     >>> addr6.reverse_pointer
     '1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa'

(Contributed by Leon Weber in bpo-20480(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16531

   (2) https://bugs.python.org/issue?@action=redirect&bpo=20480


File: python.info,  Node: json<3>,  Next: linecache<3>,  Prev: ipaddress<4>,  Up: Improved Modules<8>

1.10.5.35 json
..............

The *note json.tool: 87. command line interface now preserves the order
of keys in JSON objects passed in input.  The new ‘--sort-keys’ option
can be used to sort the keys alphabetically.  (Contributed by Berker
Peksag in bpo-21650(1).)

JSON decoder now raises *note JSONDecodeError: 1024. instead of *note
ValueError: 2ec. to provide better context information about the error.
(Contributed by Serhiy Storchaka in bpo-19361(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21650

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19361


File: python.info,  Node: linecache<3>,  Next: locale<6>,  Prev: json<3>,  Up: Improved Modules<8>

1.10.5.36 linecache
...................

A new *note lazycache(): 1026. function can be used to capture
information about a non-file-based module to permit getting its lines
later via *note getline(): 240.  This avoids doing I/O until a line is
actually needed, without having to carry the module globals around
indefinitely.  (Contributed by Robert Collins in bpo-17911(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17911


File: python.info,  Node: locale<6>,  Next: logging<5>,  Prev: linecache<3>,  Up: Improved Modules<8>

1.10.5.37 locale
................

A new *note delocalize(): 1028. function can be used to convert a string
into a normalized number string, taking the ‘LC_NUMERIC’ settings into
account:

     >>> import locale
     >>> locale.setlocale(locale.LC_NUMERIC, 'de_DE.UTF-8')
     'de_DE.UTF-8'
     >>> locale.delocalize('1.234,56')
     '1234.56'
     >>> locale.setlocale(locale.LC_NUMERIC, 'en_US.UTF-8')
     'en_US.UTF-8'
     >>> locale.delocalize('1,234.56')
     '1234.56'

(Contributed by Cédric Krier in bpo-13918(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13918


File: python.info,  Node: logging<5>,  Next: lzma,  Prev: locale<6>,  Up: Improved Modules<8>

1.10.5.38 logging
.................

All logging methods (*note Logger: d48. *note log(): 102a, *note
exception(): 102b, *note critical(): 102c, *note debug(): 102d, etc.),
now accept exception instances as an 'exc_info' argument, in addition to
boolean values and exception tuples:

     >>> import logging
     >>> try:
     ...     1/0
     ... except ZeroDivisionError as ex:
     ...     logging.error('exception', exc_info=ex)
     ERROR:root:exception

(Contributed by Yury Selivanov in bpo-20537(1).)

The *note handlers.HTTPHandler: 102e. class now accepts an optional
*note ssl.SSLContext: 357. instance to configure SSL settings used in an
HTTP connection.  (Contributed by Alex Gaynor in bpo-22788(2).)

The *note handlers.QueueListener: 242. class now takes a
'respect_handler_level' keyword argument which, if set to ‘True’, will
pass messages to handlers taking handler levels into account.
(Contributed by Vinay Sajip.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20537

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22788


File: python.info,  Node: lzma,  Next: math<8>,  Prev: logging<5>,  Up: Improved Modules<8>

1.10.5.39 lzma
..............

The *note LZMADecompressor.decompress(): 1030. method now accepts an
optional 'max_length' argument to limit the maximum size of decompressed
data.  (Contributed by Martin Panter in bpo-15955(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15955


File: python.info,  Node: math<8>,  Next: multiprocessing<7>,  Prev: lzma,  Up: Improved Modules<8>

1.10.5.40 math
..............

Two new constants have been added to the *note math: 92. module: *note
inf: e82. and *note nan: 874.  (Contributed by Mark Dickinson in
bpo-23185(1).)

A new function *note isclose(): fb2. provides a way to test for
approximate equality.  (Contributed by Chris Barker and Tal Einat in
bpo-24270(2).)

A new *note gcd(): b0e. function has been added.  The ‘fractions.gcd()’
function is now deprecated.  (Contributed by Mark Dickinson and Serhiy
Storchaka in bpo-22486(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23185

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24270

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22486


File: python.info,  Node: multiprocessing<7>,  Next: operator<3>,  Prev: math<8>,  Up: Improved Modules<8>

1.10.5.41 multiprocessing
.........................

*note sharedctypes.synchronized(): 1033. objects now support the *note
context manager: 1e1. protocol.  (Contributed by Charles-François Natali
in bpo-21565(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21565


File: python.info,  Node: operator<3>,  Next: os<11>,  Prev: multiprocessing<7>,  Up: Improved Modules<8>

1.10.5.42 operator
..................

*note attrgetter(): 1035, *note itemgetter(): c59, and *note
methodcaller(): 1036. objects now support pickling.  (Contributed by
Josh Rosenberg and Serhiy Storchaka in bpo-22955(1).)

New *note matmul(): 1037. and *note imatmul(): 1038. functions to
perform matrix multiplication.  (Contributed by Benjamin Peterson in
bpo-21176(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22955

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21176


File: python.info,  Node: os<11>,  Next: pathlib<13>,  Prev: operator<3>,  Up: Improved Modules<8>

1.10.5.43 os
............

The new *note scandir(): c56. function returning an iterator of *note
DirEntry: 6c4. objects has been added.  If possible, *note scandir():
c56. extracts file attributes while scanning a directory, removing the
need to perform subsequent system calls to determine file type or
attributes, which may significantly improve performance.  (Contributed
by Ben Hoyt with the help of Victor Stinner in bpo-22524(1).)

On Windows, a new *note stat_result.st_file_attributes: 103a. attribute
is now available.  It corresponds to the ‘dwFileAttributes’ member of
the ‘BY_HANDLE_FILE_INFORMATION’ structure returned by
‘GetFileInformationByHandle()’.  (Contributed by Ben Hoyt in
bpo-21719(2).)

The *note urandom(): 747. function now uses the ‘getrandom()’ syscall on
Linux 3.17 or newer, and ‘getentropy()’ on OpenBSD 5.6 and newer,
removing the need to use ‘/dev/urandom’ and avoiding failures due to
potential file descriptor exhaustion.  (Contributed by Victor Stinner in
bpo-22181(3).)

New *note get_blocking(): 103b. and *note set_blocking(): 103c.
functions allow getting and setting a file descriptor’s blocking mode
(*note O_NONBLOCK: 103d.)  (Contributed by Victor Stinner in
bpo-22054(4).)

The *note truncate(): 103e. and *note ftruncate(): f91. functions are
now supported on Windows.  (Contributed by Steve Dower in bpo-23668(5).)

There is a new *note os.path.commonpath(): 103f. function returning the
longest common sub-path of each passed pathname.  Unlike the *note
os.path.commonprefix(): 1040. function, it always returns a valid path:

     >>> os.path.commonprefix(['/usr/lib', '/usr/local/lib'])
     '/usr/l'

     >>> os.path.commonpath(['/usr/lib', '/usr/local/lib'])
     '/usr'

(Contributed by Rafik Draoui and Serhiy Storchaka in bpo-10395(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22524

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21719

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22181

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22054

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23668

   (6) https://bugs.python.org/issue?@action=redirect&bpo=10395


File: python.info,  Node: pathlib<13>,  Next: pickle<4>,  Prev: os<11>,  Up: Improved Modules<8>

1.10.5.44 pathlib
.................

The new *note Path.samefile(): 1042. method can be used to check whether
the path points to the same file as another path, which can be either
another *note Path: 266. object, or a string:

     >>> import pathlib
     >>> p1 = pathlib.Path('/etc/hosts')
     >>> p2 = pathlib.Path('/etc/../etc/hosts')
     >>> p1.samefile(p2)
     True

(Contributed by Vajrasky Kok and Antoine Pitrou in bpo-19775(1).)

The *note Path.mkdir(): 1043. method now accepts a new optional
'exist_ok' argument to match ‘mkdir -p’ and *note os.makedirs(): 52d.
functionality.  (Contributed by Berker Peksag in bpo-21539(2).)

There is a new *note Path.expanduser(): 1044. method to expand ‘~’ and
‘~user’ prefixes.  (Contributed by Serhiy Storchaka and Claudiu Popa in
bpo-19776(3).)

A new *note Path.home(): 1045. class method can be used to get a *note
Path: 266. instance representing the user’s home directory.
(Contributed by Victor Salgado and Mayank Tripathi in bpo-19777(4).)

New *note Path.write_text(): 1046, *note Path.read_text(): 1047, *note
Path.write_bytes(): 1048, *note Path.read_bytes(): 2df. methods to
simplify read/write operations on files.

The following code snippet will create or rewrite existing file
‘~/spam42’:

     >>> import pathlib
     >>> p = pathlib.Path('~/spam42')
     >>> p.expanduser().write_text('ham')
     3

(Contributed by Christopher Welborn in bpo-20218(5).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19775

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21539

   (3) https://bugs.python.org/issue?@action=redirect&bpo=19776

   (4) https://bugs.python.org/issue?@action=redirect&bpo=19777

   (5) https://bugs.python.org/issue?@action=redirect&bpo=20218


File: python.info,  Node: pickle<4>,  Next: poplib<2>,  Prev: pathlib<13>,  Up: Improved Modules<8>

1.10.5.45 pickle
................

Nested objects, such as unbound methods or nested classes, can now be
pickled using *note pickle protocols: 27b. older than protocol version
4.  Protocol version 4 already supports these cases.  (Contributed by
Serhiy Storchaka in bpo-23611(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23611


File: python.info,  Node: poplib<2>,  Next: re<8>,  Prev: pickle<4>,  Up: Improved Modules<8>

1.10.5.46 poplib
................

A new *note POP3.utf8(): 104b. command enables RFC 6856(1)
(Internationalized Email) support, if a POP server supports it.
(Contributed by Milan OberKirch in bpo-21804(2).)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc6856.html

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21804


File: python.info,  Node: re<8>,  Next: readline<2>,  Prev: poplib<2>,  Up: Improved Modules<8>

1.10.5.47 re
............

References and conditional references to groups with fixed length are
now allowed in lookbehind assertions:

     >>> import re
     >>> pat = re.compile(r'(a|b).(?<=\1)c')
     >>> pat.match('aac')
     <_sre.SRE_Match object; span=(0, 3), match='aac'>
     >>> pat.match('bbc')
     <_sre.SRE_Match object; span=(0, 3), match='bbc'>

(Contributed by Serhiy Storchaka in bpo-9179(1).)

The number of capturing groups in regular expressions is no longer
limited to 100.  (Contributed by Serhiy Storchaka in bpo-22437(2).)

The *note sub(): 5a3. and *note subn(): 5a4. functions now replace
unmatched groups with empty strings instead of raising an exception.
(Contributed by Serhiy Storchaka in bpo-1519638(3).)

The *note re.error: 547. exceptions have new attributes, *note msg:
104d, *note pattern: 104e, *note pos: 104f, *note lineno: 1050, and
*note colno: 1051, that provide better context information about the
error:

     >>> re.compile("""
     ...     (?x)
     ...     .++
     ... """)
     Traceback (most recent call last):
        ...
     sre_constants.error: multiple repeat at position 16 (line 3, column 7)

(Contributed by Serhiy Storchaka in bpo-22578(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9179

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22437

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1519638

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22578


File: python.info,  Node: readline<2>,  Next: selectors,  Prev: re<8>,  Up: Improved Modules<8>

1.10.5.48 readline
..................

A new *note append_history_file(): 1053. function can be used to append
the specified number of trailing elements in history to the given file.
(Contributed by Bruno Cauet in bpo-22940(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22940


File: python.info,  Node: selectors,  Next: shutil<5>,  Prev: readline<2>,  Up: Improved Modules<8>

1.10.5.49 selectors
...................

The new *note DevpollSelector: dd4. supports efficient ‘/dev/poll’
polling on Solaris.  (Contributed by Giampaolo Rodola” in bpo-18931(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18931


File: python.info,  Node: shutil<5>,  Next: signal<3>,  Prev: selectors,  Up: Improved Modules<8>

1.10.5.50 shutil
................

The *note move(): c53. function now accepts a 'copy_function' argument,
allowing, for example, the *note copy(): c51. function to be used
instead of the default *note copy2(): c52. if there is a need to ignore
file metadata when moving.  (Contributed by Claudiu Popa in
bpo-19840(1).)

The *note make_archive(): 6db. function now supports the 'xztar' format.
(Contributed by Serhiy Storchaka in bpo-5411(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19840

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5411


File: python.info,  Node: signal<3>,  Next: smtpd<2>,  Prev: shutil<5>,  Up: Improved Modules<8>

1.10.5.51 signal
................

On Windows, the *note set_wakeup_fd(): d69. function now also supports
socket handles.  (Contributed by Victor Stinner in bpo-22018(1).)

Various ‘SIG*’ constants in the *note signal: cb. module have been
converted into *note Enums: 5a.  This allows meaningful names to be
printed during debugging, instead of integer «magic numbers».
(Contributed by Giampaolo Rodola” in bpo-21076(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22018

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21076


File: python.info,  Node: smtpd<2>,  Next: smtplib<2>,  Prev: signal<3>,  Up: Improved Modules<8>

1.10.5.52 smtpd
...............

Both the ‘SMTPServer’ and ‘SMTPChannel’ classes now accept a
'decode_data' keyword argument to determine if the ‘DATA’ portion of the
SMTP transaction is decoded using the ‘"utf-8"’ codec or is instead
provided to the ‘SMTPServer.process_message()’ method as a byte string.
The default is ‘True’ for backward compatibility reasons, but will
change to ‘False’ in Python 3.6.  If 'decode_data' is set to ‘False’,
the ‘process_message’ method must be prepared to accept keyword
arguments.  (Contributed by Maciej Szulik in bpo-19662(1).)

The ‘SMTPServer’ class now advertises the ‘8BITMIME’ extension ( RFC
6152(2)) if 'decode_data' has been set ‘True’.  If the client specifies
‘BODY=8BITMIME’ on the ‘MAIL’ command, it is passed to
‘SMTPServer.process_message()’ via the 'mail_options' keyword.
(Contributed by Milan Oberkirch and R. David Murray in bpo-21795(3).)

The ‘SMTPServer’ class now also supports the ‘SMTPUTF8’ extension ( RFC
6531(4): Internationalized Email).  If the client specified ‘SMTPUTF8
BODY=8BITMIME’ on the ‘MAIL’ command, they are passed to
‘SMTPServer.process_message()’ via the 'mail_options' keyword.  It is
the responsibility of the ‘process_message’ method to correctly handle
the ‘SMTPUTF8’ data.  (Contributed by Milan Oberkirch in bpo-21725(5).)

It is now possible to provide, directly or via name resolution, IPv6
addresses in the ‘SMTPServer’ constructor, and have it successfully
connect.  (Contributed by Milan Oberkirch in bpo-14758(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19662

   (2) https://datatracker.ietf.org/doc/html/rfc6152.html

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21795

   (4) https://datatracker.ietf.org/doc/html/rfc6531.html

   (5) https://bugs.python.org/issue?@action=redirect&bpo=21725

   (6) https://bugs.python.org/issue?@action=redirect&bpo=14758


File: python.info,  Node: smtplib<2>,  Next: sndhdr,  Prev: smtpd<2>,  Up: Improved Modules<8>

1.10.5.53 smtplib
.................

A new *note SMTP.auth(): 1059. method provides a convenient way to
implement custom authentication mechanisms.  (Contributed by Milan
Oberkirch in bpo-15014(1).)

The *note SMTP.set_debuglevel(): 105a. method now accepts an additional
debuglevel (2), which enables timestamps in debug messages.
(Contributed by Gavin Chappell and Maciej Szulik in bpo-16914(2).)

Both the *note SMTP.sendmail(): 105b. and *note SMTP.send_message():
105c. methods now support RFC 6531(3) (SMTPUTF8).  (Contributed by Milan
Oberkirch and R. David Murray in bpo-22027(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15014

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16914

   (3) https://datatracker.ietf.org/doc/html/rfc6531.html

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22027


File: python.info,  Node: sndhdr,  Next: socket<9>,  Prev: smtplib<2>,  Up: Improved Modules<8>

1.10.5.54 sndhdr
................

The ‘what()’ and ‘whathdr()’ functions now return a *note namedtuple():
4e1.  (Contributed by Claudiu Popa in bpo-18615(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18615


File: python.info,  Node: socket<9>,  Next: ssl<10>,  Prev: sndhdr,  Up: Improved Modules<8>

1.10.5.55 socket
................

Functions with timeouts now use a monotonic clock, instead of a system
clock.  (Contributed by Victor Stinner in bpo-22043(1).)

A new *note socket.sendfile(): 105f. method allows sending a file over a
socket by using the high-performance *note os.sendfile(): d07. function
on UNIX, resulting in uploads being from 2 to 3 times faster than when
using plain *note socket.send(): fa9.  (Contributed by Giampaolo Rodola”
in bpo-17552(2).)

The *note socket.sendall(): faa. method no longer resets the socket
timeout every time bytes are received or sent.  The socket timeout is
now the maximum total duration to send all data.  (Contributed by Victor
Stinner in bpo-23853(3).)

The 'backlog' argument of the *note socket.listen(): 1060. method is now
optional.  By default it is set to *note SOMAXCONN: 1061. or to ‘128’,
whichever is less.  (Contributed by Charles-François Natali in
bpo-21455(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22043

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17552

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23853

   (4) https://bugs.python.org/issue?@action=redirect&bpo=21455


File: python.info,  Node: ssl<10>,  Next: sqlite3<9>,  Prev: socket<9>,  Up: Improved Modules<8>

1.10.5.56 ssl
.............

* Menu:

* Memory BIO Support::
* Application-Layer Protocol Negotiation Support::
* Other Changes::


File: python.info,  Node: Memory BIO Support,  Next: Application-Layer Protocol Negotiation Support,  Up: ssl<10>

1.10.5.57 Memory BIO Support
............................

(Contributed by Geert Jansen in bpo-21965(1).)

The new *note SSLObject: d7c. class has been added to provide SSL
protocol support for cases when the network I/O capabilities of *note
SSLSocket: ae9. are not necessary or are suboptimal.  ‘SSLObject’
represents an SSL protocol instance, but does not implement any network
I/O methods, and instead provides a memory buffer interface.  The new
*note MemoryBIO: 1064. class can be used to pass data between Python and
an SSL protocol instance.

The memory BIO SSL support is primarily intended to be used in
frameworks implementing asynchronous I/O for which *note SSLSocket:
ae9.’s readiness model («select/poll») is inefficient.

A new *note SSLContext.wrap_bio(): d7d. method can be used to create a
new ‘SSLObject’ instance.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21965


File: python.info,  Node: Application-Layer Protocol Negotiation Support,  Next: Other Changes,  Prev: Memory BIO Support,  Up: ssl<10>

1.10.5.58 Application-Layer Protocol Negotiation Support
........................................................

(Contributed by Benjamin Peterson in bpo-20188(1).)

Where OpenSSL support is present, the *note ssl: d5. module now
implements the 'Application-Layer Protocol Negotiation' TLS extension as
described in RFC 7301(2).

The new *note SSLContext.set_alpn_protocols(): 1066. can be used to
specify which protocols a socket should advertise during the TLS
handshake.

The new *note SSLSocket.selected_alpn_protocol(): 1067. returns the
protocol that was selected during the TLS handshake.  The *note
HAS_ALPN: 1068. flag indicates whether ALPN support is present.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20188

   (2) https://datatracker.ietf.org/doc/html/rfc7301.html


File: python.info,  Node: Other Changes,  Prev: Application-Layer Protocol Negotiation Support,  Up: ssl<10>

1.10.5.59 Other Changes
.......................

There is a new *note SSLSocket.version(): 106a. method to query the
actual protocol version in use.  (Contributed by Antoine Pitrou in
bpo-20421(1).)

The *note SSLSocket: ae9. class now implements a ‘SSLSocket.sendfile()’
method.  (Contributed by Giampaolo Rodola” in bpo-17552(2).)

The ‘SSLSocket.send()’ method now raises either the *note
ssl.SSLWantReadError: 106b. or *note ssl.SSLWantWriteError: 106c.
exception on a non-blocking socket if the operation would block.
Previously, it would return ‘0’.  (Contributed by Nikolaus Rath in
bpo-20951(3).)

The *note cert_time_to_seconds(): 106d. function now interprets the
input time as UTC and not as local time, per RFC 5280(4).  Additionally,
the return value is always an *note int: 19b.  (Contributed by Akira Li
in bpo-19940(5).)

New ‘SSLObject.shared_ciphers()’ and *note SSLSocket.shared_ciphers():
106e. methods return the list of ciphers sent by the client during the
handshake.  (Contributed by Benjamin Peterson in bpo-23186(6).)

The *note SSLSocket.do_handshake(): 106f, *note SSLSocket.read(): 1070,
‘SSLSocket.shutdown()’, and *note SSLSocket.write(): 1071. methods of
the *note SSLSocket: ae9. class no longer reset the socket timeout every
time bytes are received or sent.  The socket timeout is now the maximum
total duration of the method.  (Contributed by Victor Stinner in
bpo-23853(7).)

The ‘match_hostname()’ function now supports matching of IP addresses.
(Contributed by Antoine Pitrou in bpo-23239(8).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20421

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17552

   (3) https://bugs.python.org/issue?@action=redirect&bpo=20951

   (4) https://datatracker.ietf.org/doc/html/rfc5280.html

   (5) https://bugs.python.org/issue?@action=redirect&bpo=19940

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23186

   (7) https://bugs.python.org/issue?@action=redirect&bpo=23853

   (8) https://bugs.python.org/issue?@action=redirect&bpo=23239


File: python.info,  Node: sqlite3<9>,  Next: subprocess<4>,  Prev: ssl<10>,  Up: Improved Modules<8>

1.10.5.60 sqlite3
.................

The *note Row: 1073. class now fully supports the sequence protocol, in
particular *note reversed(): a67. iteration and slice indexing.
(Contributed by Claudiu Popa in bpo-10203(1); by Lucas Sinclair, Jessica
McKellar, and Serhiy Storchaka in bpo-13583(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10203

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13583


File: python.info,  Node: subprocess<4>,  Next: sys<11>,  Prev: sqlite3<9>,  Up: Improved Modules<8>

1.10.5.61 subprocess
....................

The new *note run(): d81. function has been added.  It runs the
specified command and returns a *note CompletedProcess: 1075. object,
which describes a finished process.  The new API is more consistent and
is the recommended approach to invoking subprocesses in Python code that
does not need to maintain compatibility with earlier Python versions.
(Contributed by Thomas Kluyver in bpo-23342(1).)

Examples:

     >>> subprocess.run(["ls", "-l"])  # doesn't capture output
     CompletedProcess(args=['ls', '-l'], returncode=0)

     >>> subprocess.run("exit 1", shell=True, check=True)
     Traceback (most recent call last):
       ...
     subprocess.CalledProcessError: Command 'exit 1' returned non-zero exit status 1

     >>> subprocess.run(["ls", "-l", "/dev/null"], stdout=subprocess.PIPE)
     CompletedProcess(args=['ls', '-l', '/dev/null'], returncode=0,
     stdout=b'crw-rw-rw- 1 root root 1, 3 Jan 23 16:23 /dev/null\n')

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23342


File: python.info,  Node: sys<11>,  Next: sysconfig<3>,  Prev: subprocess<4>,  Up: Improved Modules<8>

1.10.5.62 sys
.............

A new ‘set_coroutine_wrapper()’ function allows setting a global hook
that will be called whenever a *note coroutine object: 6ba. is created
by an *note async def: 7ee. function.  A corresponding
‘get_coroutine_wrapper()’ can be used to obtain a currently set wrapper.
Both functions are *note provisional: 3d1, and are intended for
debugging purposes only.  (Contributed by Yury Selivanov in
bpo-24017(1).)

A new *note is_finalizing(): c82. function can be used to check if the
Python interpreter is *note shutting down: 47a.  (Contributed by Antoine
Pitrou in bpo-22696(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24017

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22696


File: python.info,  Node: sysconfig<3>,  Next: tarfile<7>,  Prev: sys<11>,  Up: Improved Modules<8>

1.10.5.63 sysconfig
...................

The name of the user scripts directory on Windows now includes the first
two components of the Python version.  (Contributed by Paul Moore in
bpo-23437(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23437


File: python.info,  Node: tarfile<7>,  Next: threading<7>,  Prev: sysconfig<3>,  Up: Improved Modules<8>

1.10.5.64 tarfile
.................

The 'mode' argument of the *note open(): 1079. function now accepts
‘"x"’ to request exclusive creation.  (Contributed by Berker Peksag in
bpo-21717(1).)

The *note TarFile.extractall(): 29b. and *note TarFile.extract(): 29c.
methods now take a keyword argument 'numeric_owner'.  If set to ‘True’,
the extracted files and directories will be owned by the numeric ‘uid’
and ‘gid’ from the tarfile.  If set to ‘False’ (the default, and the
behavior in versions prior to 3.5), they will be owned by the named user
and group in the tarfile.  (Contributed by Michael Vogt and Eric Smith
in bpo-23193(2).)

The *note TarFile.list(): 107a. now accepts an optional 'members'
keyword argument that can be set to a subset of the list returned by
*note TarFile.getmembers(): 107b.  (Contributed by Serhiy Storchaka in
bpo-21549(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21717

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23193

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21549


File: python.info,  Node: threading<7>,  Next: time<7>,  Prev: tarfile<7>,  Up: Improved Modules<8>

1.10.5.65 threading
...................

Both the *note Lock.acquire(): 8a8. and *note RLock.acquire(): 107d.
methods now use a monotonic clock for timeout management.  (Contributed
by Victor Stinner in bpo-22043(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22043


File: python.info,  Node: time<7>,  Next: timeit<2>,  Prev: threading<7>,  Up: Improved Modules<8>

1.10.5.66 time
..............

The *note monotonic(): 55c. function is now always available.
(Contributed by Victor Stinner in bpo-22043(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22043


File: python.info,  Node: timeit<2>,  Next: tkinter<9>,  Prev: time<7>,  Up: Improved Modules<8>

1.10.5.67 timeit
................

A new command line option ‘-u’ or ‘--unit=U’ can be used to specify the
time unit for the timer output.  Supported options are ‘usec’, ‘msec’,
or ‘sec’.  (Contributed by Julian Gindi in bpo-18983(1).)

The *note timeit(): 1080. function has a new 'globals' parameter for
specifying the namespace in which the code will be running.
(Contributed by Ben Roberts in bpo-2527(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18983

   (2) https://bugs.python.org/issue?@action=redirect&bpo=2527


File: python.info,  Node: tkinter<9>,  Next: traceback<5>,  Prev: timeit<2>,  Up: Improved Modules<8>

1.10.5.68 tkinter
.................

The ‘tkinter._fix’ module used for setting up the Tcl/Tk environment on
Windows has been replaced by a private function in the ‘_tkinter’ module
which makes no permanent changes to environment variables.  (Contributed
by Zachary Ware in bpo-20035(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20035


File: python.info,  Node: traceback<5>,  Next: types<6>,  Prev: tkinter<9>,  Up: Improved Modules<8>

1.10.5.69 traceback
...................

New *note walk_stack(): 1083. and *note walk_tb(): 1084. functions to
conveniently traverse frame and *note traceback objects: cee.
(Contributed by Robert Collins in bpo-17911(1).)

New lightweight classes: *note TracebackException: 563, *note
StackSummary: 1085, and *note FrameSummary: 1086.  (Contributed by
Robert Collins in bpo-17911(2).)

Both the *note print_tb(): 1087. and *note print_stack(): 1088.
functions now support negative values for the 'limit' argument.
(Contributed by Dmitry Kazakov in bpo-22619(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17911

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17911

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22619


File: python.info,  Node: types<6>,  Next: unicodedata<9>,  Prev: traceback<5>,  Up: Improved Modules<8>

1.10.5.70 types
...............

A new *note coroutine(): 108a. function to transform *note generator:
ddb. and *note generator-like: fdd. objects into *note awaitables: 4ca.
(Contributed by Yury Selivanov in bpo-24017(1).)

A new type called *note CoroutineType: 108b, which is used for *note
coroutine: 6ba. objects created by *note async def: 7ee. functions.
(Contributed by Yury Selivanov in bpo-24400(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24017

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24400


File: python.info,  Node: unicodedata<9>,  Next: unittest<9>,  Prev: types<6>,  Up: Improved Modules<8>

1.10.5.71 unicodedata
.....................

The *note unicodedata: 10b. module now uses data from Unicode 8.0.0(1).

   ---------- Footnotes ----------

   (1) https://unicode.org/versions/Unicode8.0.0/


File: python.info,  Node: unittest<9>,  Next: unittest mock<3>,  Prev: unicodedata<9>,  Up: Improved Modules<8>

1.10.5.72 unittest
..................

The *note TestLoader.loadTestsFromModule(): 594. method now accepts a
keyword-only argument 'pattern' which is passed to ‘load_tests’ as the
third argument.  Found packages are now checked for ‘load_tests’
regardless of whether their path matches 'pattern', because it is
impossible for a package name to match the default pattern.
(Contributed by Robert Collins and Barry A. Warsaw in bpo-16662(1).)

Unittest discovery errors now are exposed in the *note
TestLoader.errors: 108e. attribute of the *note TestLoader: 593.
instance.  (Contributed by Robert Collins in bpo-19746(2).)

A new command line option ‘--locals’ to show local variables in
tracebacks.  (Contributed by Robert Collins in bpo-22936(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16662

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19746

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22936


File: python.info,  Node: unittest mock<3>,  Next: urllib<4>,  Prev: unittest<9>,  Up: Improved Modules<8>

1.10.5.73 unittest.mock
.......................

The *note Mock: c41. class has the following improvements:

   * The class constructor has a new 'unsafe' parameter, which causes
     mock objects to raise *note AttributeError: 5f0. on attribute names
     starting with ‘"assert"’.  (Contributed by Kushal Das in
     bpo-21238(1).)

   * A new *note Mock.assert_not_called(): 1090. method to check if the
     mock object was called.  (Contributed by Kushal Das in
     bpo-21262(2).)

The *note MagicMock: 1091. class now supports *note __truediv__(): 1092,
*note __divmod__(): 1093. and *note __matmul__(): f7b. operators.
(Contributed by Johannes Baiter in bpo-20968(3), and Håkan Lövdahl in
bpo-23581(4) and bpo-23568(5).)

It is no longer necessary to explicitly pass ‘create=True’ to the *note
patch(): 1094. function when patching builtin names.  (Contributed by
Kushal Das in bpo-17660(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21238

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21262

   (3) https://bugs.python.org/issue?@action=redirect&bpo=20968

   (4) https://bugs.python.org/issue?@action=redirect&bpo=23581

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23568

   (6) https://bugs.python.org/issue?@action=redirect&bpo=17660


File: python.info,  Node: urllib<4>,  Next: wsgiref,  Prev: unittest mock<3>,  Up: Improved Modules<8>

1.10.5.74 urllib
................

A new *note request.HTTPPasswordMgrWithPriorAuth: 1096. class allows
HTTP Basic Authentication credentials to be managed so as to eliminate
unnecessary ‘401’ response handling, or to unconditionally send
credentials on the first request in order to communicate with servers
that return a ‘404’ response instead of a ‘401’ if the ‘Authorization’
header is not sent.  (Contributed by Matej Cepl in bpo-19494(1) and
Akshit Khurana in bpo-7159(2).)

A new 'quote_via' argument for the *note parse.urlencode(): 1097.
function provides a way to control the encoding of query parts if
needed.  (Contributed by Samwyse and Arnon Yaari in bpo-13866(3).)

The *note request.urlopen(): 307. function accepts an *note
ssl.SSLContext: 357. object as a 'context' argument, which will be used
for the HTTPS connection.  (Contributed by Alex Gaynor in bpo-22366(4).)

The *note parse.urljoin(): 1098. was updated to use the RFC 3986(5)
semantics for the resolution of relative URLs, rather than RFC 1808(6)
and RFC 2396(7).  (Contributed by Demian Brecht and Senthil Kumaran in
bpo-22118(8).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19494

   (2) https://bugs.python.org/issue?@action=redirect&bpo=7159

   (3) https://bugs.python.org/issue?@action=redirect&bpo=13866

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22366

   (5) https://datatracker.ietf.org/doc/html/rfc3986.html

   (6) https://datatracker.ietf.org/doc/html/rfc1808.html

   (7) https://datatracker.ietf.org/doc/html/rfc2396.html

   (8) https://bugs.python.org/issue?@action=redirect&bpo=22118


File: python.info,  Node: wsgiref,  Next: xmlrpc<2>,  Prev: urllib<4>,  Up: Improved Modules<8>

1.10.5.75 wsgiref
.................

The 'headers' argument of the *note headers.Headers: 109a. class
constructor is now optional.  (Contributed by Pablo Torres Navarrete and
SilentGhost in bpo-5800(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5800


File: python.info,  Node: xmlrpc<2>,  Next: xml sax,  Prev: wsgiref,  Up: Improved Modules<8>

1.10.5.76 xmlrpc
................

The *note client.ServerProxy: c4e. class now supports the *note context
manager: 1e1. protocol.  (Contributed by Claudiu Popa in bpo-20627(1).)

The *note client.ServerProxy: c4e. constructor now accepts an optional
*note ssl.SSLContext: 357. instance.  (Contributed by Alex Gaynor in
bpo-22960(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20627

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22960


File: python.info,  Node: xml sax,  Next: zipfile<5>,  Prev: xmlrpc<2>,  Up: Improved Modules<8>

1.10.5.77 xml.sax
.................

SAX parsers now support a character stream of the *note
xmlreader.InputSource: 109d. object.  (Contributed by Serhiy Storchaka
in bpo-2175(1).)

*note parseString(): 109e. now accepts a *note str: 169. instance.
(Contributed by Serhiy Storchaka in bpo-10590(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=2175

   (2) https://bugs.python.org/issue?@action=redirect&bpo=10590


File: python.info,  Node: zipfile<5>,  Prev: xml sax,  Up: Improved Modules<8>

1.10.5.78 zipfile
.................

ZIP output can now be written to unseekable streams.  (Contributed by
Serhiy Storchaka in bpo-23252(1).)

The 'mode' argument of *note ZipFile.open(): 65d. method now accepts
‘"x"’ to request exclusive creation.  (Contributed by Serhiy Storchaka
in bpo-21717(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23252

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21717


File: python.info,  Node: Other module-level changes,  Next: Optimizations<9>,  Prev: Improved Modules<8>,  Up: What’s New In Python 3 5

1.10.6 Other module-level changes
---------------------------------

Many functions in the *note mmap: 94, ‘ossaudiodev’, *note socket: d1,
*note ssl: d5, and *note codecs: 1c. modules now accept writable *note
bytes-like objects: 193.  (Contributed by Serhiy Storchaka in
bpo-23001(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23001


File: python.info,  Node: Optimizations<9>,  Next: Build and C API Changes<3>,  Prev: Other module-level changes,  Up: What’s New In Python 3 5

1.10.7 Optimizations
--------------------

The *note os.walk(): 6d1. function has been sped up by 3 to 5 times on
POSIX systems, and by 7 to 20 times on Windows.  This was done using the
new *note os.scandir(): c56. function, which exposes file information
from the underlying ‘readdir’ or ‘FindFirstFile’/‘FindNextFile’ system
calls.  (Contributed by Ben Hoyt with help from Victor Stinner in
bpo-23605(1).)

Construction of ‘bytes(int)’ (filled by zero bytes) is faster and uses
less memory for large objects.  ‘calloc()’ is used instead of ‘malloc()’
to allocate memory for these objects.  (Contributed by Victor Stinner in
bpo-21233(2).)

Some operations on *note ipaddress: 84. *note IPv4Network: 50f. and
*note IPv6Network: 510. have been massively sped up, such as *note
subnets(): 10a2, *note supernet(): 10a3, *note
summarize_address_range(): 10a4, *note collapse_addresses(): 10a5.  The
speed up can range from 3 to 15 times.  (Contributed by Antoine Pitrou,
Michel Albert, and Markus in bpo-21486(3), bpo-21487(4), bpo-20826(5),
bpo-23266(6).)

Pickling of *note ipaddress: 84. objects was optimized to produce
significantly smaller output.  (Contributed by Serhiy Storchaka in
bpo-23133(7).)

Many operations on *note io.BytesIO: 10a6. are now 50% to 100% faster.
(Contributed by Serhiy Storchaka in bpo-15381(8) and David Wilson in
bpo-22003(9).)

The *note marshal.dumps(): 10a7. function is now faster: 65–85% with
versions 3 and 4, 20–25% with versions 0 to 2 on typical data, and up to
5 times in best cases.  (Contributed by Serhiy Storchaka in
bpo-20416(10) and bpo-23344(11).)

The UTF-32 encoder is now 3 to 7 times faster.  (Contributed by Serhiy
Storchaka in bpo-15027(12).)

Regular expressions are now parsed up to 10% faster.  (Contributed by
Serhiy Storchaka in bpo-19380(13).)

The *note json.dumps(): f43. function was optimized to run with
‘ensure_ascii=False’ as fast as with ‘ensure_ascii=True’.  (Contributed
by Naoki Inada in bpo-23206(14).)

The *note PyObject_IsInstance(): 10a8. and *note PyObject_IsSubclass():
10a9. functions have been sped up in the common case that the second
argument has *note type: f46. as its metaclass.  (Contributed Georg
Brandl by in bpo-22540(15).)

Method caching was slightly improved, yielding up to 5% performance
improvement in some benchmarks.  (Contributed by Antoine Pitrou in
bpo-22847(16).)

Objects from the *note random: bd. module now use 50% less memory on
64-bit builds.  (Contributed by Serhiy Storchaka in bpo-23488(17).)

The *note property(): 4b4. getter calls are up to 25% faster.
(Contributed by Joe Jevnik in bpo-23910(18).)

Instantiation of *note fractions.Fraction: 213. is now up to 30% faster.
(Contributed by Stefan Behnel in bpo-22464(19).)

String methods *note find(): 10aa, *note rfind(): 10ab, *note split():
10ac, *note partition(): 10ad. and the *note in: 34b. string operator
are now significantly faster for searching 1-character substrings.
(Contributed by Serhiy Storchaka in bpo-23573(20).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23605

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21233

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21486

   (4) https://bugs.python.org/issue?@action=redirect&bpo=21487

   (5) https://bugs.python.org/issue?@action=redirect&bpo=20826

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23266

   (7) https://bugs.python.org/issue?@action=redirect&bpo=23133

   (8) https://bugs.python.org/issue?@action=redirect&bpo=15381

   (9) https://bugs.python.org/issue?@action=redirect&bpo=22003

   (10) https://bugs.python.org/issue?@action=redirect&bpo=20416

   (11) https://bugs.python.org/issue?@action=redirect&bpo=23344

   (12) https://bugs.python.org/issue?@action=redirect&bpo=15027

   (13) https://bugs.python.org/issue?@action=redirect&bpo=19380

   (14) https://bugs.python.org/issue?@action=redirect&bpo=23206

   (15) https://bugs.python.org/issue?@action=redirect&bpo=22540

   (16) https://bugs.python.org/issue?@action=redirect&bpo=22847

   (17) https://bugs.python.org/issue?@action=redirect&bpo=23488

   (18) https://bugs.python.org/issue?@action=redirect&bpo=23910

   (19) https://bugs.python.org/issue?@action=redirect&bpo=22464

   (20) https://bugs.python.org/issue?@action=redirect&bpo=23573


File: python.info,  Node: Build and C API Changes<3>,  Next: Deprecated<9>,  Prev: Optimizations<9>,  Up: What’s New In Python 3 5

1.10.8 Build and C API Changes
------------------------------

New ‘calloc’ functions were added:

   * *note PyMem_RawCalloc(): 632,

   * *note PyMem_Calloc(): 10af,

   * *note PyObject_Calloc(): 10b0.

(Contributed by Victor Stinner in bpo-21233(1).)

New encoding/decoding helper functions:

   * *note Py_DecodeLocale(): dc2. (replaced ‘_Py_char2wchar()’),

   * *note Py_EncodeLocale(): dc3. (replaced ‘_Py_wchar2char()’).

(Contributed by Victor Stinner in bpo-18395(2).)

A new *note PyCodec_NameReplaceErrors(): 10b1. function to replace the
unicode encode error with ‘\N{...}’ escapes.  (Contributed by Serhiy
Storchaka in bpo-19676(3).)

A new *note PyErr_FormatV(): 10b2. function similar to *note
PyErr_Format(): 10b3, but accepts a ‘va_list’ argument.  (Contributed by
Antoine Pitrou in bpo-18711(4).)

A new *note PyExc_RecursionError: 10b4. exception.  (Contributed by
Georg Brandl in bpo-19235(5).)

New *note PyModule_FromDefAndSpec(): 10b5, *note
PyModule_FromDefAndSpec2(): 10b6, and *note PyModule_ExecDef(): 10b7.
functions introduced by PEP 489(6) – multi-phase extension module
initialization.  (Contributed by Petr Viktorin in bpo-24268(7).)

New *note PyNumber_MatrixMultiply(): 10b8. and *note
PyNumber_InPlaceMatrixMultiply(): 10b9. functions to perform matrix
multiplication.  (Contributed by Benjamin Peterson in bpo-21176(8).  See
also PEP 465(9) for details.)

The *note PyTypeObject.tp_finalize: c9f. slot is now part of the stable
ABI.

Windows builds now require Microsoft Visual C++ 14.0, which is available
as part of Visual Studio 2015(10).

Extension modules now include a platform information tag in their
filename on some platforms (the tag is optional, and CPython will import
extensions without it, although if the tag is present and mismatched,
the extension won’t be loaded):

   * On Linux, extension module filenames end with
     ‘.cpython-<major><minor>m-<architecture>-<os>.pyd’:

        * ‘<major>’ is the major number of the Python version; for
          Python 3.5 this is ‘3’.

        * ‘<minor>’ is the minor number of the Python version; for
          Python 3.5 this is ‘5’.

        * ‘<architecture>’ is the hardware architecture the extension
          module was built to run on.  It’s most commonly either ‘i386’
          for 32-bit Intel platforms or ‘x86_64’ for 64-bit Intel (and
          AMD) platforms.

        * ‘<os>’ is always ‘linux-gnu’, except for extensions built to
          talk to the 32-bit ABI on 64-bit platforms, in which case it
          is ‘linux-gnu32’ (and ‘<architecture>’ will be ‘x86_64’).

   * On Windows, extension module filenames end with
     ‘<debug>.cp<major><minor>-<platform>.pyd’:

        * ‘<major>’ is the major number of the Python version; for
          Python 3.5 this is ‘3’.

        * ‘<minor>’ is the minor number of the Python version; for
          Python 3.5 this is ‘5’.

        * ‘<platform>’ is the platform the extension module was built
          for, either ‘win32’ for Win32, ‘win_amd64’ for Win64,
          ‘win_ia64’ for Windows Itanium 64, and ‘win_arm’ for Windows
          on ARM.

        * If built in debug mode, ‘<debug>’ will be ‘_d’, otherwise it
          will be blank.

   * On OS X platforms, extension module filenames now end with
     ‘-darwin.so’.

   * On all other platforms, extension module filenames are the same as
     they were with Python 3.4.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21233

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18395

   (3) https://bugs.python.org/issue?@action=redirect&bpo=19676

   (4) https://bugs.python.org/issue?@action=redirect&bpo=18711

   (5) https://bugs.python.org/issue?@action=redirect&bpo=19235

   (6) https://peps.python.org/pep-0489/

   (7) https://bugs.python.org/issue?@action=redirect&bpo=24268

   (8) https://bugs.python.org/issue?@action=redirect&bpo=21176

   (9) https://peps.python.org/pep-0465/

   (10) 
https://visualstudio.microsoft.com/en/vs/older-downloads/#visual-studio-2015-and-other-products


File: python.info,  Node: Deprecated<9>,  Next: Removed<9>,  Prev: Build and C API Changes<3>,  Up: What’s New In Python 3 5

1.10.9 Deprecated
-----------------

* Menu:

* New Keywords: New Keywords<2>.
* Deprecated Python Behavior: Deprecated Python Behavior<2>.
* Unsupported Operating Systems::
* Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<3>.


File: python.info,  Node: New Keywords<2>,  Next: Deprecated Python Behavior<2>,  Up: Deprecated<9>

1.10.9.1 New Keywords
.....................

‘async’ and ‘await’ are not recommended to be used as variable, class,
function or module names.  Introduced by PEP 492(1) in Python 3.5, they
will become proper keywords in Python 3.7.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0492/


File: python.info,  Node: Deprecated Python Behavior<2>,  Next: Unsupported Operating Systems,  Prev: New Keywords<2>,  Up: Deprecated<9>

1.10.9.2 Deprecated Python Behavior
...................................

Raising the *note StopIteration: df7. exception inside a generator will
now generate a silent *note PendingDeprecationWarning: ac8, which will
become a non-silent deprecation warning in Python 3.6 and will trigger a
*note RuntimeError: 244. in Python 3.7.  See *note PEP 479; Change
StopIteration handling inside generators: f1d. for details.


File: python.info,  Node: Unsupported Operating Systems,  Next: Deprecated Python modules functions and methods<3>,  Prev: Deprecated Python Behavior<2>,  Up: Deprecated<9>

1.10.9.3 Unsupported Operating Systems
......................................

Windows XP is no longer supported by Microsoft, thus, per PEP 11(1),
CPython 3.5 is no longer officially supported on this OS.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0011/


File: python.info,  Node: Deprecated Python modules functions and methods<3>,  Prev: Unsupported Operating Systems,  Up: Deprecated<9>

1.10.9.4 Deprecated Python modules, functions and methods
.........................................................

The ‘formatter’ module has now graduated to full deprecation and is
still slated for removal in Python 3.6.

The ‘asyncio.async()’ function is deprecated in favor of *note
ensure_future(): e73.

The ‘smtpd’ module has in the past always decoded the DATA portion of
email messages using the ‘utf-8’ codec.  This can now be controlled by
the new 'decode_data' keyword to ‘SMTPServer’.  The default value is
‘True’, but this default is deprecated.  Specify the 'decode_data'
keyword with an appropriate value to avoid the deprecation warning.

Directly assigning values to the *note key: dfd, *note value: dfe. and
*note coded_value: dff. of *note http.cookies.Morsel: e00. objects is
deprecated.  Use the *note set(): e01. method instead.  In addition, the
undocumented 'LegalChars' parameter of *note set(): e01. is deprecated,
and is now ignored.

Passing a format string as keyword argument 'format_string' to the *note
format(): dfc. method of the *note string.Formatter: 10bf. class has
been deprecated.  (Contributed by Serhiy Storchaka in bpo-23671(1).)

The ‘platform.dist()’ and ‘platform.linux_distribution()’ functions are
now deprecated.  Linux distributions use too many different ways of
describing themselves, so the functionality is left to a package.
(Contributed by Vajrasky Kok and Berker Peksag in bpo-1322(2).)

The previously undocumented ‘from_function’ and ‘from_builtin’ methods
of *note inspect.Signature: 4e4. are deprecated.  Use the new *note
Signature.from_callable(): 943. method instead.  (Contributed by Yury
Selivanov in bpo-24248(3).)

The ‘inspect.getargspec()’ function is deprecated and scheduled to be
removed in Python 3.6.  (See bpo-20438(4) for details.)

The *note inspect: 82. *note getfullargspec(): 942, *note getcallargs():
10c0, and ‘formatargspec()’ functions are deprecated in favor of the
*note inspect.signature(): 22f. API. (Contributed by Yury Selivanov in
bpo-20438(5).)

*note getargvalues(): 10c1. and *note formatargvalues(): 10c2. functions
were inadvertently marked as deprecated with the release of Python
3.5.0.

Use of *note re.LOCALE: d65. flag with str patterns or *note re.ASCII:
83f. is now deprecated.  (Contributed by Serhiy Storchaka in
bpo-22407(6).)

Use of unrecognized special sequences consisting of ‘'\'’ and an ASCII
letter in regular expression patterns and replacement patterns now
raises a deprecation warning and will be forbidden in Python 3.6.
(Contributed by Serhiy Storchaka in bpo-23622(7).)

The undocumented and unofficial 'use_load_tests' default argument of the
*note unittest.TestLoader.loadTestsFromModule(): 594. method now is
deprecated and ignored.  (Contributed by Robert Collins and Barry A.
Warsaw in bpo-16662(8).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23671

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1322

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24248

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20438

   (5) https://bugs.python.org/issue?@action=redirect&bpo=20438

   (6) https://bugs.python.org/issue?@action=redirect&bpo=22407

   (7) https://bugs.python.org/issue?@action=redirect&bpo=23622

   (8) https://bugs.python.org/issue?@action=redirect&bpo=16662


File: python.info,  Node: Removed<9>,  Next: Porting to Python 3 5,  Prev: Deprecated<9>,  Up: What’s New In Python 3 5

1.10.10 Removed
---------------

* Menu:

* API and Feature Removals: API and Feature Removals<4>.


File: python.info,  Node: API and Feature Removals<4>,  Up: Removed<9>

1.10.10.1 API and Feature Removals
..................................

The following obsolete and previously deprecated APIs and features have
been removed:

   * The ‘__version__’ attribute has been dropped from the email
     package.  The email code hasn’t been shipped separately from the
     stdlib for a long time, and the ‘__version__’ string was not
     updated in the last few releases.

   * The internal ‘Netrc’ class in the *note ftplib: 62. module was
     deprecated in 3.4, and has now been removed.  (Contributed by Matt
     Chaput in bpo-6623(1).)

   * The concept of ‘.pyo’ files has been removed.

   * The JoinableQueue class in the provisional *note asyncio: b. module
     was deprecated in 3.4.4 and is now removed.  (Contributed by A.
     Jesse Jiryu Davis in bpo-23464(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6623

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23464


File: python.info,  Node: Porting to Python 3 5,  Next: Notable changes in Python 3 5 4,  Prev: Removed<9>,  Up: What’s New In Python 3 5

1.10.11 Porting to Python 3.5
-----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code.

* Menu:

* Changes in Python behavior: Changes in Python behavior<2>.
* Changes in the Python API: Changes in the Python API<9>.
* Changes in the C API: Changes in the C API<8>.


File: python.info,  Node: Changes in Python behavior<2>,  Next: Changes in the Python API<9>,  Up: Porting to Python 3 5

1.10.11.1 Changes in Python behavior
....................................

   * Due to an oversight, earlier Python versions erroneously accepted
     the following syntax:

          f(1 for x in [1], *args)
          f(1 for x in [1], **kwargs)

     Python 3.5 now correctly raises a *note SyntaxError: 18e, as
     generator expressions must be put in parentheses if not a sole
     argument to a function.


File: python.info,  Node: Changes in the Python API<9>,  Next: Changes in the C API<8>,  Prev: Changes in Python behavior<2>,  Up: Porting to Python 3 5

1.10.11.2 Changes in the Python API
...................................

   * PEP 475(1): System calls are now retried when interrupted by a
     signal instead of raising *note InterruptedError: f8a. if the
     Python signal handler does not raise an exception.

   * Before Python 3.5, a *note datetime.time: 1fb. object was
     considered to be false if it represented midnight in UTC. This
     behavior was considered obscure and error-prone and has been
     removed in Python 3.5.  See bpo-13936(2) for full details.

   * The ‘ssl.SSLSocket.send()’ method now raises either *note
     ssl.SSLWantReadError: 106b. or *note ssl.SSLWantWriteError: 106c.
     on a non-blocking socket if the operation would block.  Previously,
     it would return ‘0’.  (Contributed by Nikolaus Rath in
     bpo-20951(3).)

   * The ‘__name__’ attribute of generators is now set from the function
     name, instead of being set from the code name.  Use
     ‘gen.gi_code.co_name’ to retrieve the code name.  Generators also
     have a new ‘__qualname__’ attribute, the qualified name, which is
     now used for the representation of a generator (‘repr(gen)’).
     (Contributed by Victor Stinner in bpo-21205(4).)

   * The deprecated «strict» mode and argument of *note HTMLParser: a79,
     ‘HTMLParser.error()’, and the ‘HTMLParserError’ exception have been
     removed.  (Contributed by Ezio Melotti in bpo-15114(5).)  The
     'convert_charrefs' argument of *note HTMLParser: a79. is now ‘True’
     by default.  (Contributed by Berker Peksag in bpo-21047(6).)

   * Although it is not formally part of the API, it is worth noting for
     porting purposes (ie: fixing tests) that error messages that were
     previously of the form «“sometype” does not support the buffer
     protocol» are now of the form «a *note bytes-like object: 193. is
     required, not “sometype”».  (Contributed by Ezio Melotti in
     bpo-16518(7).)

   * If the current directory is set to a directory that no longer
     exists then *note FileNotFoundError: 264. will no longer be raised
     and instead *note find_spec(): 10c8. will return ‘None’ 'without'
     caching ‘None’ in *note sys.path_importer_cache: 7fb, which is
     different than the typical case (bpo-22834(8)).

   * HTTP status code and messages from *note http.client: 73. and *note
     http.server: 76. were refactored into a common *note HTTPStatus:
     afe. enum.  The values in *note http.client: 73. and *note
     http.server: 76. remain available for backwards compatibility.
     (Contributed by Demian Brecht in bpo-21793(9).)

   * When an import loader defines *note exec_module(): a6c. it is now
     expected to also define *note create_module(): eae. (raises a *note
     DeprecationWarning: 1a3. now, will be an error in Python 3.6).  If
     the loader inherits from *note importlib.abc.Loader: 10c9. then
     there is nothing to do, else simply define *note create_module():
     eae. to return ‘None’.  (Contributed by Brett Cannon in
     bpo-23014(10).)

   * The *note re.split(): 5a2. function always ignored empty pattern
     matches, so the ‘"x*"’ pattern worked the same as ‘"x+"’, and the
     ‘"\b"’ pattern never worked.  Now *note re.split(): 5a2. raises a
     warning if the pattern could match an empty string.  For
     compatibility, use patterns that never match an empty string (e.g.
     ‘"x+"’ instead of ‘"x*"’).  Patterns that could only match an empty
     string (such as ‘"\b"’) now raise an error.  (Contributed by Serhiy
     Storchaka in bpo-22818(11).)

   * The *note http.cookies.Morsel: e00. dict-like interface has been
     made self consistent: morsel comparison now takes the *note key:
     dfd. and *note value: dfe. into account, *note copy(): 10ca. now
     results in a *note Morsel: e00. instance rather than a *note dict:
     183, and *note update(): 10cb. will now raise an exception if any
     of the keys in the update dictionary are invalid.  In addition, the
     undocumented 'LegalChars' parameter of *note set(): e01. is
     deprecated and is now ignored.  (Contributed by Demian Brecht in
     bpo-2211(12).)

   * PEP 488(13) has removed ‘.pyo’ files from Python and introduced the
     optional ‘opt-’ tag in ‘.pyc’ file names.  The *note
     importlib.util.cache_from_source(): 353. has gained an
     'optimization' parameter to help control the ‘opt-’ tag.  Because
     of this, the 'debug_override' parameter of the function is now
     deprecated.  ‘.pyo’ files are also no longer supported as a file
     argument to the Python interpreter and thus serve no purpose when
     distributed on their own (i.e.  sourceless code distribution).  Due
     to the fact that the magic number for bytecode has changed in
     Python 3.5, all old ‘.pyo’ files from previous versions of Python
     are invalid regardless of this PEP.

   * The *note socket: d1. module now exports the *note
     CAN_RAW_FD_FRAMES: 10cc. constant on linux 3.6 and greater.

   * The *note ssl.cert_time_to_seconds(): 106d. function now interprets
     the input time as UTC and not as local time, per RFC 5280(14).
     Additionally, the return value is always an *note int: 19b.
     (Contributed by Akira Li in bpo-19940(15).)

   * The ‘pygettext.py’ Tool now uses the standard +NNNN format for
     timezones in the POT-Creation-Date header.

   * The *note smtplib: cf. module now uses *note sys.stderr: b35.
     instead of the previous module-level ‘stderr’ variable for debug
     output.  If your (test) program depends on patching the
     module-level variable to capture the debug output, you will need to
     update it to capture sys.stderr instead.

   * The *note str.startswith(): 10cd. and *note str.endswith(): 10ce.
     methods no longer return ‘True’ when finding the empty string and
     the indexes are completely out of range.  (Contributed by Serhiy
     Storchaka in bpo-24284(16).)

   * The *note inspect.getdoc(): bef. function now returns documentation
     strings inherited from base classes.  Documentation strings no
     longer need to be duplicated if the inherited documentation is
     appropriate.  To suppress an inherited string, an empty string must
     be specified (or the documentation may be filled in).  This change
     affects the output of the *note pydoc: ba. module and the *note
     help(): ad6. function.  (Contributed by Serhiy Storchaka in
     bpo-15582(17).)

   * Nested *note functools.partial(): 217. calls are now flattened.  If
     you were relying on the previous behavior, you can now either add
     an attribute to a *note functools.partial(): 217. object or you can
     create a subclass of *note functools.partial(): 217.  (Contributed
     by Alexander Belopolsky in bpo-7830(18).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0475/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13936

   (3) https://bugs.python.org/issue?@action=redirect&bpo=20951

   (4) https://bugs.python.org/issue?@action=redirect&bpo=21205

   (5) https://bugs.python.org/issue?@action=redirect&bpo=15114

   (6) https://bugs.python.org/issue?@action=redirect&bpo=21047

   (7) https://bugs.python.org/issue?@action=redirect&bpo=16518

   (8) https://bugs.python.org/issue?@action=redirect&bpo=22834

   (9) https://bugs.python.org/issue?@action=redirect&bpo=21793

   (10) https://bugs.python.org/issue?@action=redirect&bpo=23014

   (11) https://bugs.python.org/issue?@action=redirect&bpo=22818

   (12) https://bugs.python.org/issue?@action=redirect&bpo=2211

   (13) https://peps.python.org/pep-0488/

   (14) https://datatracker.ietf.org/doc/html/rfc5280.html

   (15) https://bugs.python.org/issue?@action=redirect&bpo=19940

   (16) https://bugs.python.org/issue?@action=redirect&bpo=24284

   (17) https://bugs.python.org/issue?@action=redirect&bpo=15582

   (18) https://bugs.python.org/issue?@action=redirect&bpo=7830


File: python.info,  Node: Changes in the C API<8>,  Prev: Changes in the Python API<9>,  Up: Porting to Python 3 5

1.10.11.3 Changes in the C API
..............................

   * The undocumented ‘format’ member of the (non-public)
     ‘PyMemoryViewObject’ structure has been removed.  All extensions
     relying on the relevant parts in ‘memoryobject.h’ must be rebuilt.

   * The ‘PyMemAllocator’ structure was renamed to *note
     PyMemAllocatorEx: 10d0. and a new ‘calloc’ field was added.

   * Removed non-documented macro ‘PyObject_REPR()’ which leaked
     references.  Use format character ‘%R’ in *note
     PyUnicode_FromFormat(): 62b.-like functions to format the *note
     repr(): 1c1. of the object.  (Contributed by Serhiy Storchaka in
     bpo-22453(1).)

   * Because the lack of the *note __module__: 617. attribute breaks
     pickling and introspection, a deprecation warning is now raised for
     builtin types without the *note __module__: 617. attribute.  This
     will be an *note AttributeError: 5f0. in the future.  (Contributed
     by Serhiy Storchaka in bpo-20204(2).)

   * As part of the PEP 492(3) implementation, the ‘tp_reserved’ slot of
     *note PyTypeObject: c9e. was replaced with a *note tp_as_async:
     10d1. slot.  Refer to *note Coroutine Objects: 10d2. for new types,
     structures and functions.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22453

   (2) https://bugs.python.org/issue?@action=redirect&bpo=20204

   (3) https://peps.python.org/pep-0492/


File: python.info,  Node: Notable changes in Python 3 5 4,  Prev: Porting to Python 3 5,  Up: What’s New In Python 3 5

1.10.12 Notable changes in Python 3.5.4
---------------------------------------

* Menu:

* New make regen-all build target: New make regen-all build target<2>.
* Removal of make touch build target: Removal of make touch build target<2>.


File: python.info,  Node: New make regen-all build target<2>,  Next: Removal of make touch build target<2>,  Up: Notable changes in Python 3 5 4

1.10.12.1 New ‘make regen-all’ build target
...........................................

To simplify cross-compilation, and to ensure that CPython can reliably
be compiled without requiring an existing version of Python to already
be available, the autotools-based build system no longer attempts to
implicitly recompile generated files based on file modification times.

Instead, a new ‘make regen-all’ command has been added to force
regeneration of these files when desired (e.g.  after an initial version
of Python has already been built based on the pregenerated versions).

More selective regeneration targets are also defined - see
Makefile.pre.in(1) for details.

(Contributed by Victor Stinner in bpo-23404(2).)

Added in version 3.5.4.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Makefile.pre.in

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23404


File: python.info,  Node: Removal of make touch build target<2>,  Prev: New make regen-all build target<2>,  Up: Notable changes in Python 3 5 4

1.10.12.2 Removal of ‘make touch’ build target
..............................................

The ‘make touch’ build target previously used to request implicit
regeneration of generated files by updating their modification times has
been removed.

It has been replaced by the new ‘make regen-all’ target.

(Contributed by Victor Stinner in bpo-23404(1).)

Cambiato nella versione 3.5.4.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23404


File: python.info,  Node: What’s New In Python 3 4,  Next: What’s New In Python 3 3,  Prev: What’s New In Python 3 5,  Up: Novità in Python

1.11 What’s New In Python 3.4
=============================


Author: R. David Murray <<rdmurray@bitdance.com>> (Editor)

This article explains the new features in Python 3.4, compared to 3.3.
Python 3.4 was released on March 16, 2014.  For full details, see the
changelog(1).

Vedi anche
..........

PEP 429(2) – Python 3.4 Release Schedule

* Menu:

* Summary – Release Highlights: Summary – Release Highlights<3>.
* New Features: New Features<13>.
* New Modules: New Modules<9>.
* Improved Modules: Improved Modules<9>.
* CPython Implementation Changes::
* Deprecated: Deprecated<10>.
* Removed: Removed<10>.
* Porting to Python 3.4: Porting to Python 3 4.
* Changed in 3.4.3: Changed in 3 4 3.

   ---------- Footnotes ----------

   (1) https://docs.python.org/3.4/whatsnew/changelog.html

   (2) https://peps.python.org/pep-0429/


File: python.info,  Node: Summary – Release Highlights<3>,  Next: New Features<13>,  Up: What’s New In Python 3 4

1.11.1 Summary – Release Highlights
-----------------------------------

New syntax features:

   * No new syntax features were added in Python 3.4.

Other new features:

   * *note pip should always be available: 10da. ( PEP 453(1)).

   * *note Newly created file descriptors are non-inheritable: 10db. (
     PEP 446(2)).

   * command line option for *note isolated mode: 10dc. (bpo-16499(3)).

   * *note improvements in the handling of codecs: 10dd. that are not
     text encodings (multiple issues).

   * *note A ModuleSpec Type: 10de. for the Import System ( PEP 451(4)).
     (Affects importer authors.)

   * The *note marshal: 91. format has been made *note more compact and
     efficient: 10df. (bpo-16475(5)).

New library modules:

   * *note asyncio: b.: *note New provisional API for asynchronous IO:
     10e0. ( PEP 3156(6)).

   * *note ensurepip: 59.: *note Bootstrapping the pip installer: 10e1.
     ( PEP 453(7)).

   * *note enum: 5a.: *note Support for enumeration types: 10e2. ( PEP
     435(8)).

   * *note pathlib: a8.: *note Object-oriented filesystem paths: 10e3. (
     PEP 428(9)).

   * *note selectors: c7.: *note High-level and efficient I/O
     multiplexing: 10e4, built upon the *note select: c6. module
     primitives (part of PEP 3156(10)).

   * *note statistics: d7.: A basic *note numerically stable statistics
     library: 10e5. ( PEP 450(11)).

   * *note tracemalloc: 105.: *note Trace Python memory allocations:
     10e6. ( PEP 454(12)).

Significantly improved library modules:

   * *note Single-dispatch generic functions: 10e7. in *note functools:
     63. ( PEP 443(13)).

   * New *note pickle: ab. *note protocol 4: 10e8. ( PEP 3154(14)).

   * *note multiprocessing: 98. now has *note an option to avoid using
     os.fork on Unix: 10e9. (bpo-8713(15)).

   * *note email: 3f. has a new submodule, *note contentmanager: 41, and
     a new *note Message: 581. subclass (*note EmailMessage: 580.) that
     *note simplify MIME handling: 10ea. (bpo-18891(16)).

   * The *note inspect: 82. and *note pydoc: ba. modules are now capable
     of correct introspection of a much wider variety of callable
     objects, which improves the output of the Python *note help(): ad6.
     system.

   * The *note ipaddress: 84. module API has been declared stable

Security improvements:

   * *note Secure and interchangeable hash algorithm: 10eb. ( PEP
     456(17)).

   * *note Make newly created file descriptors non-inheritable: 10db. (
     PEP 446(18)) to avoid leaking file descriptors to child processes.

   * New command line option for *note isolated mode: 10dc,
     (bpo-16499(19)).

   * *note multiprocessing: 98. now has *note an option to avoid using
     os.fork on Unix: 10e9.  'spawn' and 'forkserver' are more secure
     because they avoid sharing data with child processes.

   * *note multiprocessing: 98. child processes on Windows no longer
     inherit all of the parent’s inheritable handles, only the necessary
     ones.

   * A new *note hashlib.pbkdf2_hmac(): 734. function provides the
     PKCS#5 password-based key derivation function 2(20).

   * *note TLSv1.1 and TLSv1.2 support: 10ec. for *note ssl: d5.

   * *note Retrieving certificates from the Windows system cert store
     support: 10ed. for *note ssl: d5.

   * *note Server-side SNI (Server Name Indication) support: 10ee. for
     *note ssl: d5.

   * The *note ssl.SSLContext: 357. class has a *note lot of
     improvements: 10ef.

   * All modules in the standard library that support SSL now support
     server certificate verification, including hostname matching
     (‘ssl.match_hostname()’) and CRLs (Certificate Revocation lists,
     see *note ssl.SSLContext.load_verify_locations(): 10f0.).

CPython implementation improvements:

   * *note Safe object finalization: 10f1. ( PEP 442(21)).

   * Leveraging PEP 442(22), in most cases *note module globals are no
     longer set to None during finalization: 10f1. (bpo-18214(23)).

   * *note Configurable memory allocators: 10f2. ( PEP 445(24)).

   * *note Argument Clinic: 10f3. ( PEP 436(25)).

Please read on for a comprehensive list of user-facing changes,
including many other smaller improvements, CPython optimizations,
deprecations, and potential porting issues.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0453/

   (2) https://peps.python.org/pep-0446/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=16499

   (4) https://peps.python.org/pep-0451/

   (5) https://bugs.python.org/issue?@action=redirect&bpo=16475

   (6) https://peps.python.org/pep-3156/

   (7) https://peps.python.org/pep-0453/

   (8) https://peps.python.org/pep-0435/

   (9) https://peps.python.org/pep-0428/

   (10) https://peps.python.org/pep-3156/

   (11) https://peps.python.org/pep-0450/

   (12) https://peps.python.org/pep-0454/

   (13) https://peps.python.org/pep-0443/

   (14) https://peps.python.org/pep-3154/

   (15) https://bugs.python.org/issue?@action=redirect&bpo=8713

   (16) https://bugs.python.org/issue?@action=redirect&bpo=18891

   (17) https://peps.python.org/pep-0456/

   (18) https://peps.python.org/pep-0446/

   (19) https://bugs.python.org/issue?@action=redirect&bpo=16499

   (20) https://en.wikipedia.org/wiki/PBKDF2

   (21) https://peps.python.org/pep-0442/

   (22) https://peps.python.org/pep-0442/

   (23) https://bugs.python.org/issue?@action=redirect&bpo=18214

   (24) https://peps.python.org/pep-0445/

   (25) https://peps.python.org/pep-0436/


File: python.info,  Node: New Features<13>,  Next: New Modules<9>,  Prev: Summary – Release Highlights<3>,  Up: What’s New In Python 3 4

1.11.2 New Features
-------------------

* Menu:

* PEP 453; Explicit Bootstrapping of PIP in Python Installations: PEP 453 Explicit Bootstrapping of PIP in Python Installations.
* PEP 446; Newly Created File Descriptors Are Non-Inheritable: PEP 446 Newly Created File Descriptors Are Non-Inheritable.
* Improvements to Codec Handling::
* PEP 451; A ModuleSpec Type for the Import System: PEP 451 A ModuleSpec Type for the Import System.
* Other Language Changes: Other Language Changes<9>.


File: python.info,  Node: PEP 453 Explicit Bootstrapping of PIP in Python Installations,  Next: PEP 446 Newly Created File Descriptors Are Non-Inheritable,  Up: New Features<13>

1.11.2.1 PEP 453: Explicit Bootstrapping of PIP in Python Installations
.......................................................................

* Menu:

* Bootstrapping pip By Default::
* Documentation Changes::


File: python.info,  Node: Bootstrapping pip By Default,  Next: Documentation Changes,  Up: PEP 453 Explicit Bootstrapping of PIP in Python Installations

1.11.2.2 Bootstrapping pip By Default
.....................................

The new *note ensurepip: 59. module (defined in PEP 453(1)) provides a
standard cross-platform mechanism to bootstrap the pip installer into
Python installations and virtual environments.  The version of ‘pip’
included with Python 3.4.0 is ‘pip’ 1.5.4, and future 3.4.x maintenance
releases will update the bundled version to the latest version of ‘pip’
that is available at the time of creating the release candidate.

By default, the commands ‘pipX’ and ‘pipX.Y’ will be installed on all
platforms (where X.Y stands for the version of the Python installation),
along with the ‘pip’ Python package and its dependencies.  On Windows
and in virtual environments on all platforms, the unversioned ‘pip’
command will also be installed.  On other platforms, the system wide
unversioned ‘pip’ command typically refers to the separately installed
Python 2 version.

The ‘pyvenv’ command line utility and the *note venv: 117. module make
use of the *note ensurepip: 59. module to make ‘pip’ readily available
in virtual environments.  When using the command line utility, ‘pip’ is
installed by default, while when using the *note venv: 117. module *note
API: 10f7. installation of ‘pip’ must be requested explicitly.

For CPython *note source builds on POSIX systems: 10f8, the ‘make
install’ and ‘make altinstall’ commands bootstrap ‘pip’ by default.
This behaviour can be controlled through configure options, and
overridden through Makefile options.

On Windows and Mac OS X, the CPython installers now default to
installing ‘pip’ along with CPython itself (users may opt out of
installing it during the installation process).  Window users will need
to opt in to the automatic ‘PATH’ modifications to have ‘pip’ available
from the command line by default, otherwise it can still be accessed
through the Python launcher for Windows as ‘py -m pip’.

As discussed in the PEP(2) platform packagers may choose not to install
these commands by default, as long as, when invoked, they provide clear
and simple directions on how to install them on that platform (usually
using the system package manager).

     Nota: To avoid conflicts between parallel Python 2 and Python 3
     installations, only the versioned ‘pip3’ and ‘pip3.4’ commands are
     bootstrapped by default when ‘ensurepip’ is invoked directly - the
     ‘--default-pip’ option is needed to also request the unversioned
     ‘pip’ command.  ‘pyvenv’ and the Windows installer ensure that the
     unqualified ‘pip’ command is made available in those environments,
     and ‘pip’ can always be invoked via the ‘-m’ switch rather than
     directly to avoid ambiguity on systems with multiple Python
     installations.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0453/

   (2) 
https://peps.python.org/pep-0453/#recommendations-for-downstream-distributors


File: python.info,  Node: Documentation Changes,  Prev: Bootstrapping pip By Default,  Up: PEP 453 Explicit Bootstrapping of PIP in Python Installations

1.11.2.3 Documentation Changes
..............................

As part of this change, the *note Installing Python Modules: 10fa. and
distributing-index sections of the documentation have been completely
redesigned as short getting started and FAQ documents.  Most packaging
documentation has now been moved out to the Python Packaging Authority
maintained Python Packaging User Guide(1) and the documentation of the
individual projects.

However, as this migration is currently still incomplete, the legacy
versions of those guides remaining available as *note Building C and C++
Extensions with setuptools: 10fb. and *note Building C and C++
Extensions with setuptools: 10fc.

Vedi anche
..........

PEP 453(2) – Explicit bootstrapping of pip in Python installations

     PEP written by Donald Stufft and Nick Coghlan, implemented by
     Donald Stufft, Nick Coghlan, Martin von Löwis and Ned Deily.

   ---------- Footnotes ----------

   (1) https://packaging.python.org

   (2) https://peps.python.org/pep-0453/


File: python.info,  Node: PEP 446 Newly Created File Descriptors Are Non-Inheritable,  Next: Improvements to Codec Handling,  Prev: PEP 453 Explicit Bootstrapping of PIP in Python Installations,  Up: New Features<13>

1.11.2.4 PEP 446: Newly Created File Descriptors Are Non-Inheritable
....................................................................

PEP 446(1) makes newly created file descriptors *note non-inheritable:
10fe.  In general, this is the behavior an application will want: when
launching a new process, having currently open files also open in the
new process can lead to all sorts of hard to find bugs, and potentially
to security issues.

However, there are occasions when inheritance is desired.  To support
these cases, the following new functions and methods are available:

   * *note os.get_inheritable(): 10ff, *note os.set_inheritable(): 1100.

   * *note os.get_handle_inheritable(): 1101, *note
     os.set_handle_inheritable(): 1102.

   * *note socket.socket.get_inheritable(): 1103, *note
     socket.socket.set_inheritable(): 1104.

Vedi anche
..........

PEP 446(2) – Make newly created file descriptors non-inheritable

     PEP written and implemented by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0446/

   (2) https://peps.python.org/pep-0446/


File: python.info,  Node: Improvements to Codec Handling,  Next: PEP 451 A ModuleSpec Type for the Import System,  Prev: PEP 446 Newly Created File Descriptors Are Non-Inheritable,  Up: New Features<13>

1.11.2.5 Improvements to Codec Handling
.......................................

Since it was first introduced, the *note codecs: 1c. module has always
been intended to operate as a type-neutral dynamic encoding and decoding
system.  However, its close coupling with the Python text model,
especially the type restricted convenience methods on the builtin *note
str: 169, *note bytes: 192. and *note bytearray: 344. types, has
historically obscured that fact.

As a key step in clarifying the situation, the *note codecs.encode():
1106. and *note codecs.decode(): 1107. convenience functions are now
properly documented in Python 2.7, 3.3 and 3.4.  These functions have
existed in the *note codecs: 1c. module (and have been covered by the
regression test suite) since Python 2.4, but were previously only
discoverable through runtime introspection.

Unlike the convenience methods on *note str: 169, *note bytes: 192. and
*note bytearray: 344, the *note codecs: 1c. convenience functions
support arbitrary codecs in both Python 2 and Python 3, rather than
being limited to Unicode text encodings (in Python 3) or ‘basestring’
<-> ‘basestring’ conversions (in Python 2).

In Python 3.4, the interpreter is able to identify the known non-text
encodings provided in the standard library and direct users towards
these general purpose convenience functions when appropriate:

     >>> b"abcdef".decode("hex")
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     LookupError: 'hex' is not a text encoding; use codecs.decode() to handle arbitrary codecs

     >>> "hello".encode("rot13")
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     LookupError: 'rot13' is not a text encoding; use codecs.encode() to handle arbitrary codecs

     >>> open("foo.txt", encoding="hex")
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     LookupError: 'hex' is not a text encoding; use codecs.open() to handle arbitrary codecs

In a related change, whenever it is feasible without breaking backwards
compatibility, exceptions raised during encoding and decoding operations
are wrapped in a chained exception of the same type that mentions the
name of the codec responsible for producing the error:

     >>> import codecs

     >>> codecs.decode(b"abcdefgh", "hex")
     Traceback (most recent call last):
       File "/usr/lib/python3.4/encodings/hex_codec.py", line 20, in hex_decode
         return (binascii.a2b_hex(input), len(input))
     binascii.Error: Non-hexadecimal digit found

     The above exception was the direct cause of the following exception:

     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     binascii.Error: decoding with 'hex' codec failed (Error: Non-hexadecimal digit found)

     >>> codecs.encode("hello", "bz2")
     Traceback (most recent call last):
       File "/usr/lib/python3.4/encodings/bz2_codec.py", line 17, in bz2_encode
         return (bz2.compress(input), len(input))
       File "/usr/lib/python3.4/bz2.py", line 498, in compress
         return comp.compress(data) + comp.flush()
     TypeError: 'str' does not support the buffer interface

     The above exception was the direct cause of the following exception:

     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: encoding with 'bz2' codec failed (TypeError: 'str' does not support the buffer interface)

Finally, as the examples above show, these improvements have permitted
the restoration of the convenience aliases for the non-Unicode codecs
that were themselves restored in Python 3.2.  This means that encoding
binary data to and from its hexadecimal representation (for example) can
now be written as:

     >>> from codecs import encode, decode
     >>> encode(b"hello", "hex")
     b'68656c6c6f'
     >>> decode(b"68656c6c6f", "hex")
     b'hello'

The binary and text transforms provided in the standard library are
detailed in *note Binary Transforms: 1108. and *note Text Transforms:
1109.

(Contributed by Nick Coghlan in bpo-7475(1), bpo-17827(2), bpo-17828(3)
and bpo-19619(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=7475

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17827

   (3) https://bugs.python.org/issue?@action=redirect&bpo=17828

   (4) https://bugs.python.org/issue?@action=redirect&bpo=19619


File: python.info,  Node: PEP 451 A ModuleSpec Type for the Import System,  Next: Other Language Changes<9>,  Prev: Improvements to Codec Handling,  Up: New Features<13>

1.11.2.6 PEP 451: A ModuleSpec Type for the Import System
.........................................................

PEP 451(1) provides an encapsulation of the information about a module
that the import machinery will use to load it (that is, a module
specification).  This helps simplify both the import implementation and
several import-related APIs.  The change is also a stepping stone for
several future import-related improvements(2).

The public-facing changes from the PEP are entirely backward-compatible.
Furthermore, they should be transparent to everyone but importer
authors.  Key finder and loader methods have been deprecated, but they
will continue working.  New importers should use the new methods
described in the PEP. Existing importers should be updated to implement
the new methods.  See the *note Deprecated: 110b. section for a list of
methods that should be replaced and their replacements.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0451/

   (2) 
https://mail.python.org/pipermail/python-dev/2013-November/130111.html


File: python.info,  Node: Other Language Changes<9>,  Prev: PEP 451 A ModuleSpec Type for the Import System,  Up: New Features<13>

1.11.2.7 Other Language Changes
...............................

Some smaller changes made to the core Python language are:

   * Unicode database updated to UCD version 6.3.

   * *note min(): 110d. and *note max(): 110e. now accept a 'default'
     keyword-only argument that can be used to specify the value they
     return if the iterable they are evaluating has no elements.
     (Contributed by Julian Berman in bpo-18111(1).)

   * Module objects are now *note weakly referenceable: 110f.

   * Module ‘__file__’ attributes (and related values) should now always
     contain absolute paths by default, with the sole exception of
     ‘__main__.__file__’ when a script has been executed directly using
     a relative path.  (Contributed by Brett Cannon in bpo-18416(2).)

   * All the UTF-* codecs (except UTF-7) now reject surrogates during
     both encoding and decoding unless the ‘surrogatepass’ error handler
     is used, with the exception of the UTF-16 decoder (which accepts
     valid surrogate pairs) and the UTF-16 encoder (which produces them
     while encoding non-BMP characters).  (Contributed by Victor
     Stinner, Kang-Hao (Kenny) Lu and Serhiy Storchaka in bpo-12892(3).)

   * New German EBCDIC *note codec: fba. ‘cp273’.  (Contributed by
     Michael Bierenfeld and Andrew Kuchling in bpo-1097797(4).)

   * New Ukrainian *note codec: fba. ‘cp1125’.  (Contributed by Serhiy
     Storchaka in bpo-19668(5).)

   * *note bytes: 192.join() and *note bytearray: 344.join() now accept
     arbitrary buffer objects as arguments.  (Contributed by Antoine
     Pitrou in bpo-15958(6).)

   * The *note int: 19b. constructor now accepts any object that has an
     ‘__index__’ method for its 'base' argument.  (Contributed by Mark
     Dickinson in bpo-16772(7).)

   * Frame objects now have a *note clear(): 585. method that clears all
     references to local variables from the frame.  (Contributed by
     Antoine Pitrou in bpo-17934(8).)

   * *note memoryview: 165. is now registered as a *note Sequence: 1f,
     and supports the *note reversed(): a67. builtin.  (Contributed by
     Nick Coghlan and Claudiu Popa in bpo-18690(9) and bpo-19078(10).)

   * Signatures reported by *note help(): ad6. have been modified and
     improved in several cases as a result of the introduction of
     Argument Clinic and other changes to the *note inspect: 82. and
     *note pydoc: ba. modules.

   * *note __length_hint__(): 1110. is now part of the formal language
     specification (see PEP 424(11)).  (Contributed by Armin Ronacher in
     bpo-16148(12).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18111

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18416

   (3) https://bugs.python.org/issue?@action=redirect&bpo=12892

   (4) https://bugs.python.org/issue?@action=redirect&bpo=1097797

   (5) https://bugs.python.org/issue?@action=redirect&bpo=19668

   (6) https://bugs.python.org/issue?@action=redirect&bpo=15958

   (7) https://bugs.python.org/issue?@action=redirect&bpo=16772

   (8) https://bugs.python.org/issue?@action=redirect&bpo=17934

   (9) https://bugs.python.org/issue?@action=redirect&bpo=18690

   (10) https://bugs.python.org/issue?@action=redirect&bpo=19078

   (11) https://peps.python.org/pep-0424/

   (12) https://bugs.python.org/issue?@action=redirect&bpo=16148


File: python.info,  Node: New Modules<9>,  Next: Improved Modules<9>,  Prev: New Features<13>,  Up: What’s New In Python 3 4

1.11.3 New Modules
------------------

* Menu:

* asyncio: asyncio<14>.
* ensurepip: ensurepip<2>.
* enum: enum<9>.
* pathlib: pathlib<14>.
* selectors: selectors<2>.
* statistics: statistics<5>.
* tracemalloc: tracemalloc<4>.


File: python.info,  Node: asyncio<14>,  Next: ensurepip<2>,  Up: New Modules<9>

1.11.3.1 asyncio
................

The new *note asyncio: b. module (defined in PEP 3156(1)) provides a
standard pluggable event loop model for Python, providing solid
asynchronous IO support in the standard library, and making it easier
for other event loop implementations to interoperate with the standard
library and each other.

For Python 3.4, this module is considered a *note provisional API: 3d1.

Vedi anche
..........

PEP 3156(2) – Asynchronous IO Support Rebooted: the «asyncio» Module

     PEP written and implementation led by Guido van Rossum.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3156/

   (2) https://peps.python.org/pep-3156/


File: python.info,  Node: ensurepip<2>,  Next: enum<9>,  Prev: asyncio<14>,  Up: New Modules<9>

1.11.3.2 ensurepip
..................

The new *note ensurepip: 59. module is the primary infrastructure for
the PEP 453(1) implementation.  In the normal course of events end users
will not need to interact with this module, but it can be used to
manually bootstrap ‘pip’ if the automated bootstrapping into an
installation or virtual environment was declined.

*note ensurepip: 59. includes a bundled copy of ‘pip’, up-to-date as of
the first release candidate of the release of CPython with which it
ships (this applies to both maintenance releases and feature releases).
‘ensurepip’ does not access the internet.  If the installation has
internet access, after ‘ensurepip’ is run the bundled ‘pip’ can be used
to upgrade ‘pip’ to a more recent release than the bundled one.  (Note
that such an upgraded version of ‘pip’ is considered to be a separately
installed package and will not be removed if Python is uninstalled.)

The module is named 'ensure'pip because if called when ‘pip’ is already
installed, it does nothing.  It also has an ‘--upgrade’ option that will
cause it to install the bundled copy of ‘pip’ if the existing installed
version of ‘pip’ is older than the bundled copy.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0453/


File: python.info,  Node: enum<9>,  Next: pathlib<14>,  Prev: ensurepip<2>,  Up: New Modules<9>

1.11.3.3 enum
.............

The new *note enum: 5a. module (defined in PEP 435(1)) provides a
standard implementation of enumeration types, allowing other modules
(such as *note socket: d1.) to provide more informative error messages
and better debugging support by replacing opaque integer constants with
backwards compatible enumeration values.

Vedi anche
..........

PEP 435(2) – Adding an Enum type to the Python standard library

     PEP written by Barry Warsaw, Eli Bendersky and Ethan Furman,
     implemented by Ethan Furman.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0435/

   (2) https://peps.python.org/pep-0435/


File: python.info,  Node: pathlib<14>,  Next: selectors<2>,  Prev: enum<9>,  Up: New Modules<9>

1.11.3.4 pathlib
................

The new *note pathlib: a8. module offers classes representing filesystem
paths with semantics appropriate for different operating systems.  Path
classes are divided between 'pure paths', which provide purely
computational operations without I/O, and 'concrete paths', which
inherit from pure paths but also provide I/O operations.

For Python 3.4, this module is considered a *note provisional API: 3d1.

Vedi anche
..........

PEP 428(1) – The pathlib module – object-oriented filesystem paths

     PEP written and implemented by Antoine Pitrou.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0428/


File: python.info,  Node: selectors<2>,  Next: statistics<5>,  Prev: pathlib<14>,  Up: New Modules<9>

1.11.3.5 selectors
..................

The new *note selectors: c7. module (created as part of implementing PEP
3156(1)) allows high-level and efficient I/O multiplexing, built upon
the *note select: c6. module primitives.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3156/


File: python.info,  Node: statistics<5>,  Next: tracemalloc<4>,  Prev: selectors<2>,  Up: New Modules<9>

1.11.3.6 statistics
...................

The new *note statistics: d7. module (defined in PEP 450(1)) offers some
core statistics functionality directly in the standard library.  This
module supports calculation of the mean, median, mode, variance and
standard deviation of a data series.

Vedi anche
..........

PEP 450(2) – Adding A Statistics Module To The Standard Library

     PEP written and implemented by Steven D’Aprano

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0450/

   (2) https://peps.python.org/pep-0450/


File: python.info,  Node: tracemalloc<4>,  Prev: statistics<5>,  Up: New Modules<9>

1.11.3.7 tracemalloc
....................

The new *note tracemalloc: 105. module (defined in PEP 454(1)) is a
debug tool to trace memory blocks allocated by Python.  It provides the
following information:

   * Trace where an object was allocated

   * Statistics on allocated memory blocks per filename and per line
     number: total size, number and average size of allocated memory
     blocks

   * Compute the differences between two snapshots to detect memory
     leaks

Vedi anche
..........

PEP 454(2) – Add a new tracemalloc module to trace Python memory allocations

     PEP written and implemented by Victor Stinner

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0454/

   (2) https://peps.python.org/pep-0454/


File: python.info,  Node: Improved Modules<9>,  Next: CPython Implementation Changes,  Prev: New Modules<9>,  Up: What’s New In Python 3 4

1.11.4 Improved Modules
-----------------------

* Menu:

* abc::
* aifc: aifc<2>.
* argparse: argparse<7>.
* audioop::
* base64: base64<4>.
* collections: collections<6>.
* colorsys::
* contextlib: contextlib<6>.
* dbm: dbm<6>.
* dis: dis<5>.
* doctest: doctest<4>.
* email: email<5>.
* filecmp::
* functools: functools<6>.
* gc: gc<6>.
* glob: glob<4>.
* hashlib: hashlib<6>.
* hmac: hmac<4>.
* html::
* http: http<4>.
* idlelib and IDLE: idlelib and IDLE<4>.
* importlib: importlib<9>.
* inspect: inspect<9>.
* ipaddress: ipaddress<5>.
* logging: logging<6>.
* marshal: marshal<2>.
* mmap: mmap<3>.
* multiprocessing: multiprocessing<8>.
* operator: operator<4>.
* os: os<12>.
* pdb: pdb<8>.
* pickle: pickle<5>.
* plistlib: plistlib<2>.
* poplib: poplib<3>.
* pprint: pprint<4>.
* pty: pty<2>.
* pydoc: pydoc<5>.
* re: re<9>.
* resource::
* select::
* shelve: shelve<2>.
* shutil: shutil<6>.
* smtpd: smtpd<3>.
* smtplib: smtplib<3>.
* socket: socket<10>.
* sqlite3: sqlite3<10>.
* ssl: ssl<11>.
* stat::
* struct: struct<3>.
* subprocess: subprocess<5>.
* sunau: sunau<2>.
* sys: sys<12>.
* tarfile: tarfile<8>.
* textwrap: textwrap<2>.
* threading: threading<8>.
* traceback: traceback<6>.
* types: types<7>.
* urllib: urllib<5>.
* unittest: unittest<10>.
* venv: venv<7>.
* wave: wave<2>.
* weakref: weakref<2>.
* xml.etree: xml etree<2>.
* zipfile: zipfile<6>.


File: python.info,  Node: abc,  Next: aifc<2>,  Up: Improved Modules<9>

1.11.4.1 abc
............

New function *note abc.get_cache_token(): 111b. can be used to know when
to invalidate caches that are affected by changes in the object graph.
(Contributed by Łukasz Langa in bpo-16832(1).)

New class *note ABC: 111c. has *note ABCMeta: 111d. as its meta class.
Using ‘ABC’ as a base class has essentially the same effect as
specifying ‘metaclass=abc.ABCMeta’, but is simpler to type and easier to
read.  (Contributed by Bruno Dupuis in bpo-16049(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16832

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16049


File: python.info,  Node: aifc<2>,  Next: argparse<7>,  Prev: abc,  Up: Improved Modules<9>

1.11.4.2 aifc
.............

The ‘getparams()’ method now returns a namedtuple rather than a plain
tuple.  (Contributed by Claudiu Popa in bpo-17818(1).)

‘aifc.open()’ now supports the context management protocol: when used in
a *note with: 186. block, the ‘close()’ method of the returned object
will be called automatically at the end of the block.  (Contributed by
Serhiy Storchacha in bpo-16486(2).)

The ‘writeframesraw()’ and ‘writeframes()’ methods now accept any *note
bytes-like object: 193.  (Contributed by Serhiy Storchaka in
bpo-8311(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17818

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16486

   (3) https://bugs.python.org/issue?@action=redirect&bpo=8311


File: python.info,  Node: argparse<7>,  Next: audioop,  Prev: aifc<2>,  Up: Improved Modules<9>

1.11.4.3 argparse
.................

The *note FileType: 30c. class now accepts 'encoding' and 'errors'
arguments, which are passed through to *note open(): 316.  (Contributed
by Lucas Maystre in bpo-11175(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11175


File: python.info,  Node: audioop,  Next: base64<4>,  Prev: argparse<7>,  Up: Improved Modules<9>

1.11.4.4 audioop
................

‘audioop’ now supports 24-bit samples.  (Contributed by Serhiy Storchaka
in bpo-12866(1).)

New ‘byteswap()’ function converts big-endian samples to little-endian
and vice versa.  (Contributed by Serhiy Storchaka in bpo-19641(2).)

All ‘audioop’ functions now accept any *note bytes-like object: 193.
Strings are not accepted: they didn’t work before, now they raise an
error right away.  (Contributed by Serhiy Storchaka in bpo-16685(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12866

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19641

   (3) https://bugs.python.org/issue?@action=redirect&bpo=16685


File: python.info,  Node: base64<4>,  Next: collections<6>,  Prev: audioop,  Up: Improved Modules<9>

1.11.4.5 base64
...............

The encoding and decoding functions in *note base64: f. now accept any
*note bytes-like object: 193. in cases where it previously required a
*note bytes: 192. or *note bytearray: 344. instance.  (Contributed by
Nick Coghlan in bpo-17839(1).)

New functions *note a85encode(): 1122, *note a85decode(): 1123, *note
b85encode(): 1124, and *note b85decode(): 1125. provide the ability to
encode and decode binary data from and to ‘Ascii85’ and the
git/mercurial ‘Base85’ formats, respectively.  The ‘a85’ functions have
options that can be used to make them compatible with the variants of
the ‘Ascii85’ encoding, including the Adobe variant.  (Contributed by
Martin Morrison, the Mercurial project, Serhiy Storchaka, and Antoine
Pitrou in bpo-17618(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17839

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17618


File: python.info,  Node: collections<6>,  Next: colorsys,  Prev: base64<4>,  Up: Improved Modules<9>

1.11.4.6 collections
....................

The *note ChainMap.new_child(): 1127. method now accepts an 'm' argument
specifying the child map to add to the chain.  This allows an existing
mapping and/or a custom mapping type to be used for the child.
(Contributed by Vinay Sajip in bpo-16613(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16613


File: python.info,  Node: colorsys,  Next: contextlib<6>,  Prev: collections<6>,  Up: Improved Modules<9>

1.11.4.7 colorsys
.................

The number of digits in the coefficients for the RGB — YIQ conversions
have been expanded so that they match the FCC NTSC versions.  The change
in results should be less than 1% and may better match results found
elsewhere.  (Contributed by Brian Landers and Serhiy Storchaka in
bpo-14323(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14323


File: python.info,  Node: contextlib<6>,  Next: dbm<6>,  Prev: colorsys,  Up: Improved Modules<9>

1.11.4.8 contextlib
...................

The new *note contextlib.suppress: 112a. context manager helps to
clarify the intent of code that deliberately suppresses exceptions from
a single statement.  (Contributed by Raymond Hettinger in bpo-15806(1)
and Zero Piraeus in bpo-19266(2).)

The new *note contextlib.redirect_stdout(): fe9. context manager makes
it easier for utility scripts to handle inflexible APIs that write their
output to *note sys.stdout: ccf. and don’t provide any options to
redirect it.  Using the context manager, the *note sys.stdout: ccf.
output can be redirected to any other stream or, in conjunction with
*note io.StringIO: 112b, to a string.  The latter can be especially
useful, for example, to capture output from a function that was written
to implement a command line interface.  It is recommended only for
utility scripts because it affects the global state of *note sys.stdout:
ccf.  (Contributed by Raymond Hettinger in bpo-15805(3).)

The *note contextlib: 27. documentation has also been updated to include
a *note discussion: 112c. of the differences between single use,
reusable and reentrant context managers.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15806

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19266

   (3) https://bugs.python.org/issue?@action=redirect&bpo=15805


File: python.info,  Node: dbm<6>,  Next: dis<5>,  Prev: contextlib<6>,  Up: Improved Modules<9>

1.11.4.9 dbm
............

*note dbm.open(): 112e. objects now support the context management
protocol.  When used in a *note with: 186. statement, the ‘close’ method
of the database object will be called automatically at the end of the
block.  (Contributed by Claudiu Popa and Nick Coghlan in bpo-19282(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19282


File: python.info,  Node: dis<5>,  Next: doctest<4>,  Prev: dbm<6>,  Up: Improved Modules<9>

1.11.4.10 dis
.............

Functions *note show_code(): 1130, *note dis(): 205, *note distb(): 206,
and *note disassemble(): 207. now accept a keyword-only 'file' argument
that controls where they write their output.

The *note dis: 3c. module is now built around an *note Instruction: 203.
class that provides object oriented access to the details of each
individual bytecode operation.

A new method, *note get_instructions(): 4ed, provides an iterator that
emits the Instruction stream for a given piece of Python code.  Thus it
is now possible to write a program that inspects and manipulates a
bytecode object in ways different from those provided by the *note dis:
3c. module itself.  For example:

     >>> import dis
     >>> for instr in dis.get_instructions(lambda x: x + 1):
     ...     print(instr.opname)
     LOAD_FAST
     LOAD_CONST
     BINARY_ADD
     RETURN_VALUE

The various display tools in the *note dis: 3c. module have been
rewritten to use these new components.

In addition, a new application-friendly class *note Bytecode: 204.
provides an object-oriented API for inspecting bytecode in both in
human-readable form and for iterating over instructions.  The *note
Bytecode: 204. constructor takes the same arguments that *note
get_instructions(): 4ed. does (plus an optional 'current_offset'), and
the resulting object can be iterated to produce *note Instruction: 203.
objects.  But it also has a *note dis: 1131. method, equivalent to
calling *note dis: 205. on the constructor argument, but returned as a
multi-line string:

     >>> bytecode = dis.Bytecode(lambda x: x + 1, current_offset=3)
     >>> for instr in bytecode:
     ...     print('{} ({})'.format(instr.opname, instr.opcode))
     LOAD_FAST (124)
     LOAD_CONST (100)
     BINARY_ADD (23)
     RETURN_VALUE (83)
     >>> bytecode.dis().splitlines()
     ['  1           0 LOAD_FAST                0 (x)',
      '      -->     3 LOAD_CONST               1 (1)',
      '              6 BINARY_ADD',
      '              7 RETURN_VALUE']

*note Bytecode: 204. also has a class method, *note from_traceback():
1132, that provides the ability to manipulate a traceback (that is,
‘print(Bytecode.from_traceback(tb).dis())’ is equivalent to
‘distb(tb)’).

(Contributed by Nick Coghlan, Ryan Kelly and Thomas Kluyver in
bpo-11816(1) and Claudiu Popa in bpo-17916(2).)

New function *note stack_effect(): 1133. computes the effect on the
Python stack of a given opcode and argument, information that is not
otherwise available.  (Contributed by Larry Hastings in bpo-19722(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11816

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17916

   (3) https://bugs.python.org/issue?@action=redirect&bpo=19722


File: python.info,  Node: doctest<4>,  Next: email<5>,  Prev: dis<5>,  Up: Improved Modules<9>

1.11.4.11 doctest
.................

A new *note option flag: 1135, *note FAIL_FAST: 1136, halts test running
as soon as the first failure is detected.  (Contributed by R. David
Murray and Daniel Urban in bpo-16522(1).)

The *note doctest: 3e. command line interface now uses *note argparse:
7, and has two new options, ‘-o’ and ‘-f’.  ‘-o’ allows *note doctest
options: 1135. to be specified on the command line, and ‘-f’ is a
shorthand for ‘-o FAIL_FAST’ (to parallel the similar option supported
by the *note unittest: 10c. CLI). (Contributed by R. David Murray in
bpo-11390(2).)

*note doctest: 3e. will now find doctests in extension module ‘__doc__’
strings.  (Contributed by Zachary Ware in bpo-3158(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16522

   (2) https://bugs.python.org/issue?@action=redirect&bpo=11390

   (3) https://bugs.python.org/issue?@action=redirect&bpo=3158


File: python.info,  Node: email<5>,  Next: filecmp,  Prev: doctest<4>,  Up: Improved Modules<9>

1.11.4.12 email
...............

*note as_string(): 1138. now accepts a 'policy' argument to override the
default policy of the message when generating a string representation of
it.  This means that ‘as_string’ can now be used in more circumstances,
instead of having to create and use a *note generator: 44. in order to
pass formatting parameters to its ‘flatten’ method.  (Contributed by R.
David Murray in bpo-18600(1).)

New method *note as_bytes(): 1139. added to produce a bytes
representation of the message in a fashion similar to how ‘as_string’
produces a string representation.  It does not accept the 'maxheaderlen'
argument, but does accept the 'unixfrom' and 'policy' arguments.  The
*note Message: 581. *note __bytes__(): 113a. method calls it, meaning
that ‘bytes(mymsg)’ will now produce the intuitive result: a bytes
object containing the fully formatted message.  (Contributed by R. David
Murray in bpo-18600(2).)

The *note Message.set_param(): 113b. message now accepts a 'replace'
keyword argument.  When specified, the associated header will be updated
without changing its location in the list of headers.  For backward
compatibility, the default is ‘False’.  (Contributed by R. David Murray
in bpo-18891(3).)  A pair of new subclasses of *note Message: 581. have
been added (*note EmailMessage: 580. and *note MIMEPart: 113c.), along
with a new sub-module, *note contentmanager: 41. and a new *note policy:
53. attribute *note content_manager: 113d.  All documentation is
currently in the new module, which is being added as part of email’s new
*note provisional API: 3d1.  These classes provide a number of new
methods that make extracting content from and inserting content into
email messages much easier.  For details, see the *note contentmanager:
41. documentation and the *note email; Examples: 113e.  These API
additions complete the bulk of the work that was planned as part of the
email6 project.  The currently provisional API is scheduled to become
final in Python 3.5 (possibly with a few minor additions in the area of
error handling).  (Contributed by R. David Murray in bpo-18891(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18600

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18600

   (3) https://bugs.python.org/issue?@action=redirect&bpo=18891

   (4) https://bugs.python.org/issue?@action=redirect&bpo=18891


File: python.info,  Node: filecmp,  Next: functools<6>,  Prev: email<5>,  Up: Improved Modules<9>

1.11.4.13 filecmp
.................

A new *note clear_cache(): 1140. function provides the ability to clear
the *note filecmp: 5e. comparison cache, which uses *note os.stat():
26d. information to determine if the file has changed since the last
compare.  This can be used, for example, if the file might have been
changed and re-checked in less time than the resolution of a particular
filesystem’s file modification time field.  (Contributed by Mark Levitt
in bpo-18149(1).)

New module attribute *note DEFAULT_IGNORES: 1141. provides the list of
directories that are used as the default value for the 'ignore'
parameter of the *note dircmp(): 1142. function.  (Contributed by Eli
Bendersky in bpo-15442(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18149

   (2) https://bugs.python.org/issue?@action=redirect&bpo=15442


File: python.info,  Node: functools<6>,  Next: gc<6>,  Prev: filecmp,  Up: Improved Modules<9>

1.11.4.14 functools
...................

The new *note partialmethod(): 218. descriptor brings partial argument
application to descriptors, just as *note partial(): 217. provides for
normal callables.  The new descriptor also makes it easier to get
arbitrary callables (including *note partial(): 217. instances) to
behave like normal instance methods when included in a class definition.
(Contributed by Alon Horev and Nick Coghlan in bpo-4331(1).)  The new
*note singledispatch(): 84c. decorator brings support for
single-dispatch generic functions to the Python standard library.  Where
object oriented programming focuses on grouping multiple operations on a
common set of data into a class, a generic function focuses on grouping
multiple implementations of an operation that allows it to work with
'different' kinds of data.

Vedi anche
..........

PEP 443(2) – Single-dispatch generic functions

     PEP written and implemented by Łukasz Langa.

*note total_ordering(): 1144. now supports a return value of *note
NotImplemented: 1a2. from the underlying comparison function.
(Contributed by Katie Miller in bpo-10042(3).)

A pure-python version of the *note partial(): 217. function is now in
the stdlib; in CPython it is overridden by the C accelerated version,
but it is available for other implementations to use.  (Contributed by
Brian Thorne in bpo-12428(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4331

   (2) https://peps.python.org/pep-0443/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=10042

   (4) https://bugs.python.org/issue?@action=redirect&bpo=12428


File: python.info,  Node: gc<6>,  Next: glob<4>,  Prev: functools<6>,  Up: Improved Modules<9>

1.11.4.15 gc
............

New function *note get_stats(): 2dc. returns a list of three
per-generation dictionaries containing the collections statistics since
interpreter startup.  (Contributed by Antoine Pitrou in bpo-16351(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16351


File: python.info,  Node: glob<4>,  Next: hashlib<6>,  Prev: gc<6>,  Up: Improved Modules<9>

1.11.4.16 glob
..............

A new function *note escape(): 1147. provides a way to escape special
characters in a filename so that they do not become part of the globbing
expansion but are instead matched literally.  (Contributed by Serhiy
Storchaka in bpo-8402(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8402


File: python.info,  Node: hashlib<6>,  Next: hmac<4>,  Prev: glob<4>,  Up: Improved Modules<9>

1.11.4.17 hashlib
.................

A new *note hashlib.pbkdf2_hmac(): 734. function provides the PKCS#5
password-based key derivation function 2(1).  (Contributed by Christian
Heimes in bpo-18582(2).)

The *note name: 1149. attribute of *note hashlib: 6c. hash objects is
now a formally supported interface.  It has always existed in CPython’s
*note hashlib: 6c. (although it did not return lower case names for all
supported hashes), but it was not a public interface and so some other
Python implementations have not previously supported it.  (Contributed
by Jason R. Coombs in bpo-18532(3).)

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/PBKDF2

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18582

   (3) https://bugs.python.org/issue?@action=redirect&bpo=18532


File: python.info,  Node: hmac<4>,  Next: html,  Prev: hashlib<6>,  Up: Improved Modules<9>

1.11.4.18 hmac
..............

*note hmac: 6e. now accepts ‘bytearray’ as well as ‘bytes’ for the 'key'
argument to the *note new(): c98. function, and the 'msg' parameter to
both the *note new(): c98. function and the *note update(): 114b. method
now accepts any type supported by the *note hashlib: 6c. module.
(Contributed by Jonas Borgström in bpo-18240(1).)

The 'digestmod' argument to the *note hmac.new(): c98. function may now
be any hash digest name recognized by *note hashlib: 6c.  In addition,
the current behavior in which the value of 'digestmod' defaults to ‘MD5’
is deprecated: in a future version of Python there will be no default
value.  (Contributed by Christian Heimes in bpo-17276(2).)

With the addition of *note block_size: 114c. and *note name: 114d.
attributes (and the formal documentation of the *note digest_size: 114e.
attribute), the *note hmac: 6e. module now conforms fully to the PEP
247(3) API. (Contributed by Christian Heimes in bpo-18775(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18240

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17276

   (3) https://peps.python.org/pep-0247/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=18775


File: python.info,  Node: html,  Next: http<4>,  Prev: hmac<4>,  Up: Improved Modules<9>

1.11.4.19 html
..............

New function *note unescape(): b52. function converts HTML5 character
references to the corresponding Unicode characters.  (Contributed by
Ezio Melotti in bpo-2927(1).)

*note HTMLParser: a79. accepts a new keyword argument 'convert_charrefs'
that, when ‘True’, automatically converts all character references.  For
backward-compatibility, its value defaults to ‘False’, but it will
change to ‘True’ in a future version of Python, so you are invited to
set it explicitly and update your code to use this new feature.
(Contributed by Ezio Melotti in bpo-13633(2).)

The 'strict' argument of *note HTMLParser: a79. is now deprecated.
(Contributed by Ezio Melotti in bpo-15114(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=2927

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13633

   (3) https://bugs.python.org/issue?@action=redirect&bpo=15114


File: python.info,  Node: http<4>,  Next: idlelib and IDLE<4>,  Prev: html,  Up: Improved Modules<9>

1.11.4.20 http
..............

*note send_error(): 1151. now accepts an optional additional 'explain'
parameter which can be used to provide an extended error description,
overriding the hardcoded default if there is one.  This extended error
description will be formatted using the *note error_message_format:
1152. attribute and sent as the body of the error response.
(Contributed by Karl Cow in bpo-12921(1).)

The *note http.server: 76. *note command line interface: 1153. now has a
‘-b/--bind’ option that causes the server to listen on a specific
address.  (Contributed by Malte Swart in bpo-17764(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12921

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17764


File: python.info,  Node: idlelib and IDLE<4>,  Next: importlib<9>,  Prev: http<4>,  Up: Improved Modules<9>

1.11.4.21 idlelib and IDLE
..........................

Since idlelib implements the IDLE shell and editor and is not intended
for import by other programs, it gets improvements with every release.
See ‘Lib/idlelib/NEWS.txt’ for a cumulative list of changes since 3.3.0,
as well as changes made in future 3.4.x releases.  This file is also
available from the IDLE Help ‣ About IDLE dialog.


File: python.info,  Node: importlib<9>,  Next: inspect<9>,  Prev: idlelib and IDLE<4>,  Up: Improved Modules<9>

1.11.4.22 importlib
...................

The *note InspectLoader: 1156. ABC defines a new method, *note
source_to_code(): 1014. that accepts source data and a path and returns
a code object.  The default implementation is equivalent to
‘compile(data, path, 'exec', dont_inherit=True)’.  (Contributed by Eric
Snow and Brett Cannon in bpo-15627(1).)

*note InspectLoader: 1156. also now has a default implementation for the
*note get_code(): 1157. method.  However, it will normally be desirable
to override the default implementation for performance reasons.
(Contributed by Brett Cannon in bpo-18072(2).)

The *note reload(): 73e. function has been moved from ‘imp’ to *note
importlib: 7b. as part of the ‘imp’ module deprecation.  (Contributed by
Berker Peksag in bpo-18193(3).)

*note importlib.util: 81. now has a *note MAGIC_NUMBER: 738. attribute
providing access to the bytecode version number.  This replaces the
‘get_magic()’ function in the deprecated ‘imp’ module.  (Contributed by
Brett Cannon in bpo-18192(4).)

New *note importlib.util: 81. functions *note cache_from_source(): 353.
and *note source_from_cache(): 73f. replace the same-named functions in
the deprecated ‘imp’ module.  (Contributed by Brett Cannon in
bpo-18194(5).)

The *note importlib: 7b. bootstrap *note NamespaceLoader: 1158. now
conforms to the *note InspectLoader: 1156. ABC, which means that ‘runpy’
and ‘python -m’ can now be used with namespace packages.  (Contributed
by Brett Cannon in bpo-18058(6).)

*note importlib.util: 81. has a new function *note decode_source():
1159. that decodes source from bytes using universal newline processing.
This is useful for implementing *note InspectLoader.get_source(): 115a.
methods.

*note importlib.machinery.ExtensionFileLoader: eb0. now has a *note
get_filename(): 115b. method.  This was inadvertently omitted in the
original implementation.  (Contributed by Eric Snow in bpo-19152(7).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15627

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18072

   (3) https://bugs.python.org/issue?@action=redirect&bpo=18193

   (4) https://bugs.python.org/issue?@action=redirect&bpo=18192

   (5) https://bugs.python.org/issue?@action=redirect&bpo=18194

   (6) https://bugs.python.org/issue?@action=redirect&bpo=18058

   (7) https://bugs.python.org/issue?@action=redirect&bpo=19152


File: python.info,  Node: inspect<9>,  Next: ipaddress<5>,  Prev: importlib<9>,  Up: Improved Modules<9>

1.11.4.23 inspect
.................

The *note inspect: 82. module now offers a basic *note command line
interface: 115d. to quickly display source code and other information
for modules, classes and functions.  (Contributed by Claudiu Popa and
Nick Coghlan in bpo-18626(1).)

*note unwrap(): 115e. makes it easy to unravel wrapper function chains
created by *note functools.wraps(): 115f. (and any other API that sets
the ‘__wrapped__’ attribute on a wrapper function).  (Contributed by
Daniel Urban, Aaron Iles and Nick Coghlan in bpo-13266(2).)

As part of the implementation of the new *note enum: 5a. module, the
*note inspect: 82. module now has substantially better support for
custom ‘__dir__’ methods and dynamic class attributes provided through
metaclasses.  (Contributed by Ethan Furman in bpo-18929(3) and
bpo-19030(4).)

*note getfullargspec(): 942. and ‘getargspec()’ now use the *note
signature(): 22f. API. This allows them to support a much broader range
of callables, including those with ‘__signature__’ attributes, those
with metadata provided by argument clinic, *note functools.partial():
217. objects and more.  Note that, unlike *note signature(): 22f, these
functions still ignore ‘__wrapped__’ attributes, and report the already
bound first argument for bound methods, so it is still necessary to
update your code to use *note signature(): 22f. directly if those
features are desired.  (Contributed by Yury Selivanov in bpo-17481(5).)

*note signature(): 22f. now supports duck types of CPython functions,
which adds support for functions compiled with Cython.  (Contributed by
Stefan Behnel and Yury Selivanov in bpo-17159(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18626

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13266

   (3) https://bugs.python.org/issue?@action=redirect&bpo=18929

   (4) https://bugs.python.org/issue?@action=redirect&bpo=19030

   (5) https://bugs.python.org/issue?@action=redirect&bpo=17481

   (6) https://bugs.python.org/issue?@action=redirect&bpo=17159


File: python.info,  Node: ipaddress<5>,  Next: logging<6>,  Prev: inspect<9>,  Up: Improved Modules<9>

1.11.4.24 ipaddress
...................

*note ipaddress: 84. was added to the standard library in Python 3.3 as
a *note provisional API: 3d1.  With the release of Python 3.4, this
qualification has been removed: *note ipaddress: 84. is now considered a
stable API, covered by the normal standard library requirements to
maintain backwards compatibility.

A new *note is_global: 1161. property is ‘True’ if an address is
globally routeable.  (Contributed by Peter Moody in bpo-17400(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17400


File: python.info,  Node: logging<6>,  Next: marshal<2>,  Prev: ipaddress<5>,  Up: Improved Modules<9>

1.11.4.25 logging
.................

The *note TimedRotatingFileHandler: 1163. has a new 'atTime' parameter
that can be used to specify the time of day when rollover should happen.
(Contributed by Ronald Oussoren in bpo-9556(1).)

*note SocketHandler: 1164. and *note DatagramHandler: 1165. now support
Unix domain sockets (by setting 'port' to ‘None’).  (Contributed by
Vinay Sajip in commit ce46195b56a9.)

*note fileConfig(): d4a. now accepts a *note
configparser.RawConfigParser: 1166. subclass instance for the 'fname'
parameter.  This facilitates using a configuration file when logging
configuration is just a part of the overall application configuration,
or where the application modifies the configuration before passing it to
*note fileConfig(): d4a.  (Contributed by Vinay Sajip in bpo-16110(2).)

Logging configuration data received from a socket via the *note
logging.config.listen(): 1167. function can now be validated before
being processed by supplying a verification function as the argument to
the new 'verify' keyword argument.  (Contributed by Vinay Sajip in
bpo-15452(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9556

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16110

   (3) https://bugs.python.org/issue?@action=redirect&bpo=15452


File: python.info,  Node: marshal<2>,  Next: mmap<3>,  Prev: logging<6>,  Up: Improved Modules<9>

1.11.4.26 marshal
.................

The default *note marshal: 91. version has been bumped to 3.  The code
implementing the new version restores the Python2 behavior of recording
only one copy of interned strings and preserving the interning on
deserialization, and extends this «one copy» ability to any object type
(including handling recursive references).  This reduces both the size
of ‘.pyc’ files and the amount of memory a module occupies in memory
when it is loaded from a ‘.pyc’ (or ‘.pyo’) file.  (Contributed by
Kristján Valur Jónsson in bpo-16475(1), with additional speedups by
Antoine Pitrou in bpo-19219(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16475

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19219


File: python.info,  Node: mmap<3>,  Next: multiprocessing<8>,  Prev: marshal<2>,  Up: Improved Modules<9>

1.11.4.27 mmap
..............

mmap objects are now *note weakly referenceable: 110f.  (Contributed by
Valerie Lambert in bpo-4885(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4885


File: python.info,  Node: multiprocessing<8>,  Next: operator<4>,  Prev: mmap<3>,  Up: Improved Modules<9>

1.11.4.28 multiprocessing
.........................

On Unix two new *note start methods: 1d5, ‘spawn’ and ‘forkserver’, have
been added for starting processes using *note multiprocessing: 98.
These make the mixing of processes with threads more robust, and the
‘spawn’ method matches the semantics that multiprocessing has always
used on Windows.  New function *note get_all_start_methods(): 116b.
reports all start methods available on the platform, *note
get_start_method(): 116c. reports the current start method, and *note
set_start_method(): 24b. sets the start method.  (Contributed by Richard
Oudkerk in bpo-8713(1).)

*note multiprocessing: 98. also now has the concept of a ‘context’,
which determines how child processes are created.  New function *note
get_context(): 24a. returns a context that uses a specified start
method.  It has the same API as the *note multiprocessing: 98. module
itself, so you can use it to create *note Pool: 116d.s and other objects
that will operate within that context.  This allows a framework and an
application or different parts of the same application to use
multiprocessing without interfering with each other.  (Contributed by
Richard Oudkerk in bpo-18999(2).)

Except when using the old 'fork' start method, child processes no longer
inherit unneeded handles/file descriptors from their parents (part of
bpo-8713(3)).

*note multiprocessing: 98. now relies on *note runpy: c3. (which
implements the ‘-m’ switch) to initialise ‘__main__’ appropriately in
child processes when using the ‘spawn’ or ‘forkserver’ start methods.
This resolves some edge cases where combining multiprocessing, the ‘-m’
command line switch, and explicit relative imports could cause obscure
failures in child processes.  (Contributed by Nick Coghlan in
bpo-19946(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8713

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18999

   (3) https://bugs.python.org/issue?@action=redirect&bpo=8713

   (4) https://bugs.python.org/issue?@action=redirect&bpo=19946


File: python.info,  Node: operator<4>,  Next: os<12>,  Prev: multiprocessing<8>,  Up: Improved Modules<9>

1.11.4.29 operator
..................

New function *note length_hint(): 116f. provides an implementation of
the specification for how the *note __length_hint__(): 1110. special
method should be used, as part of the PEP 424(1) formal specification of
this language feature.  (Contributed by Armin Ronacher in bpo-16148(2).)

There is now a pure-python version of the *note operator: a3. module
available for reference and for use by alternate implementations of
Python.  (Contributed by Zachary Ware in bpo-16694(3).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0424/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16148

   (3) https://bugs.python.org/issue?@action=redirect&bpo=16694


File: python.info,  Node: os<12>,  Next: pdb<8>,  Prev: operator<4>,  Up: Improved Modules<9>

1.11.4.30 os
............

There are new functions to get and set the *note inheritable flag: 10fe.
of a file descriptor (*note os.get_inheritable(): 10ff, *note
os.set_inheritable(): 1100.) or a Windows handle (*note
os.get_handle_inheritable(): 1101, *note os.set_handle_inheritable():
1102.).

New function *note cpu_count(): 4dc. reports the number of CPUs
available on the platform on which Python is running (or ‘None’ if the
count can’t be determined).  The *note multiprocessing.cpu_count():
1171. function is now implemented in terms of this function).
(Contributed by Trent Nelson, Yogesh Chaudhari, Victor Stinner, and
Charles-François Natali in bpo-17914(1).)

*note os.path.samestat(): 1172. is now available on the Windows platform
(and the *note os.path.samefile(): 1173. implementation is now shared
between Unix and Windows).  (Contributed by Brian Curtin in
bpo-11939(2).)

*note os.path.ismount(): c09. now recognizes volumes mounted below a
drive root on Windows.  (Contributed by Tim Golden in bpo-9035(3).)

*note os.open(): f94. supports two new flags on platforms that provide
them, *note O_PATH: 1174. (un-opened file descriptor), and *note
O_TMPFILE: 1175. (unnamed temporary file; as of 3.4.0 release available
only on Linux systems with a kernel version of 3.11 or newer that have
uapi headers).  (Contributed by Christian Heimes in bpo-18673(4) and
Benjamin Peterson, respectively.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17914

   (2) https://bugs.python.org/issue?@action=redirect&bpo=11939

   (3) https://bugs.python.org/issue?@action=redirect&bpo=9035

   (4) https://bugs.python.org/issue?@action=redirect&bpo=18673


File: python.info,  Node: pdb<8>,  Next: pickle<5>,  Prev: os<12>,  Up: Improved Modules<9>

1.11.4.31 pdb
.............

*note pdb: aa. has been enhanced to handle generators, *note yield: bc4,
and ‘yield from’ in a more useful fashion.  This is especially helpful
when debugging *note asyncio: b. based programs.  (Contributed by Andrew
Svetlov and Xavier de Gaye in bpo-16596(1).)

The ‘print’ command has been removed from *note pdb: aa, restoring
access to the Python *note print(): 1177. function from the pdb command
line.  Python2’s ‘pdb’ did not have a ‘print’ command; instead, entering
‘print’ executed the ‘print’ statement.  In Python3 ‘print’ was
mistakenly made an alias for the pdb *note p: 1178. command.  ‘p’,
however, prints the ‘repr’ of its argument, not the ‘str’ like the
Python2 ‘print’ command did.  Worse, the Python3 ‘pdb print’ command
shadowed the Python3 ‘print’ function, making it inaccessible at the
‘pdb’ prompt.  (Contributed by Connor Osborn in bpo-18764(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16596

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18764


File: python.info,  Node: pickle<5>,  Next: plistlib<2>,  Prev: pdb<8>,  Up: Improved Modules<9>

1.11.4.32 pickle
................

*note pickle: ab. now supports (but does not use by default) a new
pickle protocol, protocol 4.  This new protocol addresses a number of
issues that were present in previous protocols, such as the
serialization of nested classes, very large strings and containers, and
classes whose *note __new__(): 7a1. method takes keyword-only arguments.
It also provides some efficiency improvements.

Vedi anche
..........

PEP 3154(1) – Pickle protocol 4

     PEP written by Antoine Pitrou and implemented by Alexandre
     Vassalotti.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3154/


File: python.info,  Node: plistlib<2>,  Next: poplib<3>,  Prev: pickle<5>,  Up: Improved Modules<9>

1.11.4.33 plistlib
..................

*note plistlib: b0. now has an API that is similar to the standard
pattern for stdlib serialization protocols, with new *note load(): b4a,
*note dump(): b4c, *note loads(): b4b, and *note dumps(): b4d.
functions.  (The older API is now deprecated.)  In addition to the
already supported XML plist format (*note FMT_XML: 117b.), it also now
supports the binary plist format (*note FMT_BINARY: 117c.).
(Contributed by Ronald Oussoren and others in bpo-14455(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14455


File: python.info,  Node: poplib<3>,  Next: pprint<4>,  Prev: plistlib<2>,  Up: Improved Modules<9>

1.11.4.34 poplib
................

Two new methods have been added to *note poplib: b1.: *note capa():
117e, which returns the list of capabilities advertised by the POP
server, and *note stls(): 117f, which switches a clear-text POP3 session
into an encrypted POP3 session if the POP server supports it.
(Contributed by Lorenzo Catucci in bpo-4473(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4473


File: python.info,  Node: pprint<4>,  Next: pty<2>,  Prev: poplib<3>,  Up: Improved Modules<9>

1.11.4.35 pprint
................

The *note pprint: b3. module’s *note PrettyPrinter: 1181. class and its
*note pformat(): 1182, and *note pprint(): a2b. functions have a new
option, 'compact', that controls how the output is formatted.  Currently
setting 'compact' to ‘True’ means that sequences will be printed with as
many sequence elements as will fit within 'width' on each (indented)
line.  (Contributed by Serhiy Storchaka in bpo-19132(1).)

Long strings are now wrapped using Python’s normal line continuation
syntax.  (Contributed by Antoine Pitrou in bpo-17150(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19132

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17150


File: python.info,  Node: pty<2>,  Next: pydoc<5>,  Prev: pprint<4>,  Up: Improved Modules<9>

1.11.4.36 pty
.............

*note pty.spawn(): 1184. now returns the status value from *note
os.waitpid(): f9c. on the child process, instead of ‘None’.
(Contributed by Gregory P. Smith.)


File: python.info,  Node: pydoc<5>,  Next: re<9>,  Prev: pty<2>,  Up: Improved Modules<9>

1.11.4.37 pydoc
...............

The *note pydoc: ba. module is now based directly on the *note
inspect.signature(): 22f. introspection API, allowing it to provide
signature information for a wider variety of callable objects.  This
change also means that ‘__wrapped__’ attributes are now taken into
account when displaying help information.  (Contributed by Larry
Hastings in bpo-19674(1).)

The *note pydoc: ba. module no longer displays the ‘self’ parameter for
already bound methods.  Instead, it aims to always display the exact
current signature of the supplied callable.  (Contributed by Larry
Hastings in bpo-20710(2).)

In addition to the changes that have been made to *note pydoc: ba.
directly, its handling of custom ‘__dir__’ methods and various
descriptor behaviours has also been improved substantially by the
underlying changes in the *note inspect: 82. module.

As the *note help(): ad6. builtin is based on *note pydoc: ba, the above
changes also affect the behaviour of *note help(): ad6.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19674

   (2) https://bugs.python.org/issue?@action=redirect&bpo=20710


File: python.info,  Node: re<9>,  Next: resource,  Prev: pydoc<5>,  Up: Improved Modules<9>

1.11.4.38 re
............

New *note fullmatch(): 1187. function and *note Pattern.fullmatch():
1188. method anchor the pattern at both ends of the string to match.
This provides a way to be explicit about the goal of the match, which
avoids a class of subtle bugs where ‘$’ characters get lost during code
changes or the addition of alternatives to an existing regular
expression.  (Contributed by Matthew Barnett in bpo-16203(1).)

The repr of *note regex objects: 1189. now includes the pattern and the
flags; the repr of *note match objects: 118a. now includes the start,
end, and the part of the string that matched.  (Contributed by Hugo
Lopes Tavares and Serhiy Storchaka in bpo-13592(2) and bpo-17087(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16203

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13592

   (3) https://bugs.python.org/issue?@action=redirect&bpo=17087


File: python.info,  Node: resource,  Next: select,  Prev: re<9>,  Up: Improved Modules<9>

1.11.4.39 resource
..................

New *note prlimit(): 118c. function, available on Linux platforms with a
kernel version of 2.6.36 or later and glibc of 2.13 or later, provides
the ability to query or set the resource limits for processes other than
the one making the call.  (Contributed by Christian Heimes in
bpo-16595(1).)

On Linux kernel version 2.6.36 or later, there are also some new Linux
specific constants: *note RLIMIT_MSGQUEUE: 118d, *note RLIMIT_NICE:
118e, *note RLIMIT_RTPRIO: 118f, *note RLIMIT_RTTIME: 1190, and *note
RLIMIT_SIGPENDING: 1191.  (Contributed by Christian Heimes in
bpo-19324(2).)

On FreeBSD version 9 and later, there some new FreeBSD specific
constants: *note RLIMIT_SBSIZE: 1192, *note RLIMIT_SWAP: 1193, and *note
RLIMIT_NPTS: 1194.  (Contributed by Claudiu Popa in bpo-19343(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16595

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19324

   (3) https://bugs.python.org/issue?@action=redirect&bpo=19343


File: python.info,  Node: select,  Next: shelve<2>,  Prev: resource,  Up: Improved Modules<9>

1.11.4.40 select
................

*note epoll: 1196. objects now support the context management protocol.
When used in a *note with: 186. statement, the *note close(): 1197.
method will be called automatically at the end of the block.
(Contributed by Serhiy Storchaka in bpo-16488(1).)

*note devpoll: 1198. objects now have *note fileno(): 1199. and *note
close(): 119a. methods, as well as a new attribute *note closed: 119b.
(Contributed by Victor Stinner in bpo-18794(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16488

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18794


File: python.info,  Node: shelve<2>,  Next: shutil<6>,  Prev: select,  Up: Improved Modules<9>

1.11.4.41 shelve
................

*note Shelf: 119d. instances may now be used in *note with: 186.
statements, and will be automatically closed at the end of the ‘with’
block.  (Contributed by Filip Gruszczyński in bpo-13896(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13896


File: python.info,  Node: shutil<6>,  Next: smtpd<3>,  Prev: shelve<2>,  Up: Improved Modules<9>

1.11.4.42 shutil
................

*note copyfile(): c50. now raises a specific *note Error: 119f.
subclass, *note SameFileError: 11a0, when the source and destination are
the same file, which allows an application to take appropriate action on
this specific error.  (Contributed by Atsuo Ishimoto and Hynek Schlawack
in bpo-1492704(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1492704


File: python.info,  Node: smtpd<3>,  Next: smtplib<3>,  Prev: shutil<6>,  Up: Improved Modules<9>

1.11.4.43 smtpd
...............

The ‘SMTPServer’ and ‘SMTPChannel’ classes now accept a 'map' keyword
argument which, if specified, is passed in to ‘asynchat.async_chat’ as
its 'map' argument.  This allows an application to avoid affecting the
global socket map.  (Contributed by Vinay Sajip in bpo-11959(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11959


File: python.info,  Node: smtplib<3>,  Next: socket<10>,  Prev: smtpd<3>,  Up: Improved Modules<9>

1.11.4.44 smtplib
.................

*note SMTPException: 11a3. is now a subclass of *note OSError: 2c0,
which allows both socket level errors and SMTP protocol level errors to
be caught in one try/except statement by code that only cares whether or
not an error occurred.  (Contributed by Ned Jackson Lovely in
bpo-2118(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=2118


File: python.info,  Node: socket<10>,  Next: sqlite3<10>,  Prev: smtplib<3>,  Up: Improved Modules<9>

1.11.4.45 socket
................

The socket module now supports the *note CAN_BCM: 11a5. protocol on
platforms that support it.  (Contributed by Brian Thorne in
bpo-15359(1).)

Socket objects have new methods to get or set their *note inheritable
flag: 10fe, *note get_inheritable(): 1103. and *note set_inheritable():
1104.

The ‘socket.AF_*’ and ‘socket.SOCK_*’ constants are now enumeration
values using the new *note enum: 5a. module.  This allows meaningful
names to be printed during debugging, instead of integer «magic
numbers».

The *note AF_LINK: 11a6. constant is now available on BSD and OSX.

*note inet_pton(): b5d. and *note inet_ntop(): 11a7. are now supported
on Windows.  (Contributed by Atsuo Ishimoto in bpo-7171(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15359

   (2) https://bugs.python.org/issue?@action=redirect&bpo=7171


File: python.info,  Node: sqlite3<10>,  Next: ssl<11>,  Prev: socket<10>,  Up: Improved Modules<9>

1.11.4.46 sqlite3
.................

A new boolean parameter to the *note connect(): 5a6. function, 'uri',
can be used to indicate that the 'database' parameter is a ‘uri’ (see
the SQLite URI documentation(1)).  (Contributed by poq in bpo-13773(2).)

   ---------- Footnotes ----------

   (1) https://www.sqlite.org/uri.html

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13773


File: python.info,  Node: ssl<11>,  Next: stat,  Prev: sqlite3<10>,  Up: Improved Modules<9>

1.11.4.47 ssl
.............

*note PROTOCOL_TLSv1_1: 11aa. and *note PROTOCOL_TLSv1_2: 11ab. (TLSv1.1
and TLSv1.2 support) have been added; support for these protocols is
only available if Python is linked with OpenSSL 1.0.1 or later.
(Contributed by Michele Orrù and Antoine Pitrou in bpo-16692(1).)  New
function *note create_default_context(): 480. provides a standard way to
obtain an *note SSLContext: 357. whose settings are intended to be a
reasonable balance between compatibility and security.  These settings
are more stringent than the defaults provided by the *note SSLContext:
357. constructor, and may be adjusted in the future, without prior
deprecation, if best-practice security requirements change.  The new
recommended best practice for using stdlib libraries that support SSL is
to use *note create_default_context(): 480. to obtain an *note
SSLContext: 357. object, modify it if needed, and then pass it as the
'context' argument of the appropriate stdlib API. (Contributed by
Christian Heimes in bpo-19689(2).)

*note SSLContext: 357. method *note load_verify_locations(): 10f0.
accepts a new optional argument 'cadata', which can be used to provide
PEM or DER encoded certificates directly via strings or bytes,
respectively.  (Contributed by Christian Heimes in bpo-18138(3).)

New function *note get_default_verify_paths(): 11ac. returns a named
tuple of the paths and environment variables that the *note
set_default_verify_paths(): 11ad. method uses to set OpenSSL’s default
‘cafile’ and ‘capath’.  This can be an aid in debugging default
verification issues.  (Contributed by Christian Heimes in bpo-18143(4).)

*note SSLContext: 357. has a new method, *note cert_store_stats(): 11ae,
that reports the number of loaded ‘X.509’ certs, ‘X.509 CA’ certs, and
certificate revocation lists (‘crl’s), as well as a *note
get_ca_certs(): 11af. method that returns a list of the loaded ‘CA’
certificates.  (Contributed by Christian Heimes in bpo-18147(5).)

If OpenSSL 0.9.8 or later is available, *note SSLContext: 357. has a new
attribute *note verify_flags: 11b0. that can be used to control the
certificate verification process by setting it to some combination of
the new constants *note VERIFY_DEFAULT: 11b1, *note
VERIFY_CRL_CHECK_LEAF: 11b2, *note VERIFY_CRL_CHECK_CHAIN: 11b3, or
*note VERIFY_X509_STRICT: 482.  OpenSSL does not do any CRL verification
by default.  (Contributed by Christien Heimes in bpo-8813(6).)

New *note SSLContext: 357. method *note load_default_certs(): 11b4.
loads a set of default «certificate authority» (CA) certificates from
default locations, which vary according to the platform.  It can be used
to load both TLS web server authentication certificates (‘purpose=’*note
SERVER_AUTH: 11b5.) for a client to use to verify a server, and
certificates for a server to use in verifying client certificates
(‘purpose=’*note CLIENT_AUTH: 11b6.).  (Contributed by Christian Heimes
in bpo-19292(7).)  Two new windows-only functions, *note
enum_certificates(): 11b7. and *note enum_crls(): 11b8. provide the
ability to retrieve certificates, certificate information, and CRLs from
the Windows cert store.  (Contributed by Christian Heimes in
bpo-17134(8).)  Support for server-side SNI (Server Name Indication)
using the new *note ssl.SSLContext.set_servername_callback(): 11b9.
method.  (Contributed by Daniel Black in bpo-8109(9).)

The dictionary returned by *note SSLSocket.getpeercert(): 11ba. contains
additional ‘X509v3’ extension items: ‘crlDistributionPoints’,
‘calIssuers’, and ‘OCSP’ URIs.  (Contributed by Christian Heimes in
bpo-18379(10).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16692

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19689

   (3) https://bugs.python.org/issue?@action=redirect&bpo=18138

   (4) https://bugs.python.org/issue?@action=redirect&bpo=18143

   (5) https://bugs.python.org/issue?@action=redirect&bpo=18147

   (6) https://bugs.python.org/issue?@action=redirect&bpo=8813

   (7) https://bugs.python.org/issue?@action=redirect&bpo=19292

   (8) https://bugs.python.org/issue?@action=redirect&bpo=17134

   (9) https://bugs.python.org/issue?@action=redirect&bpo=8109

   (10) https://bugs.python.org/issue?@action=redirect&bpo=18379


File: python.info,  Node: stat,  Next: struct<3>,  Prev: ssl<11>,  Up: Improved Modules<9>

1.11.4.48 stat
..............

The *note stat: d6. module is now backed by a C implementation in
‘_stat’.  A C implementation is required as most of the values aren’t
standardized and are platform-dependent.  (Contributed by Christian
Heimes in bpo-11016(1).)

The module supports new *note ST_MODE: 11bc. flags, *note S_IFDOOR:
11bd, *note S_IFPORT: 11be, and *note S_IFWHT: 11bf.  (Contributed by
Christian Hiemes in bpo-11016(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11016

   (2) https://bugs.python.org/issue?@action=redirect&bpo=11016


File: python.info,  Node: struct<3>,  Next: subprocess<5>,  Prev: stat,  Up: Improved Modules<9>

1.11.4.49 struct
................

New function *note iter_unpack: 11c1. and a new *note
struct.Struct.iter_unpack(): 11c2. method on compiled formats provide
streamed unpacking of a buffer containing repeated instances of a given
format of data.  (Contributed by Antoine Pitrou in bpo-17804(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17804


File: python.info,  Node: subprocess<5>,  Next: sunau<2>,  Prev: struct<3>,  Up: Improved Modules<9>

1.11.4.50 subprocess
....................

*note check_output(): 11c4. now accepts an 'input' argument that can be
used to provide the contents of ‘stdin’ for the command that is run.
(Contributed by Zack Weinberg in bpo-16624(1).)

*note getoutput(): 11c5. and *note getstatusoutput(): 11c6. now work on
Windows.  This change was actually inadvertently made in 3.3.4.
(Contributed by Tim Golden in bpo-10197(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16624

   (2) https://bugs.python.org/issue?@action=redirect&bpo=10197


File: python.info,  Node: sunau<2>,  Next: sys<12>,  Prev: subprocess<5>,  Up: Improved Modules<9>

1.11.4.51 sunau
...............

The ‘getparams()’ method now returns a namedtuple rather than a plain
tuple.  (Contributed by Claudiu Popa in bpo-18901(1).)

‘sunau.open()’ now supports the context management protocol: when used
in a *note with: 186. block, the ‘close’ method of the returned object
will be called automatically at the end of the block.  (Contributed by
Serhiy Storchaka in bpo-18878(2).)

‘AU_write.setsampwidth()’ now supports 24 bit samples, thus adding
support for writing 24 sample using the module.  (Contributed by Serhiy
Storchaka in bpo-19261(3).)

The ‘writeframesraw()’ and ‘writeframes()’ methods now accept any *note
bytes-like object: 193.  (Contributed by Serhiy Storchaka in
bpo-8311(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18901

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18878

   (3) https://bugs.python.org/issue?@action=redirect&bpo=19261

   (4) https://bugs.python.org/issue?@action=redirect&bpo=8311


File: python.info,  Node: sys<12>,  Next: tarfile<8>,  Prev: sunau<2>,  Up: Improved Modules<9>

1.11.4.52 sys
.............

New function *note sys.getallocatedblocks(): 11c9. returns the current
number of blocks allocated by the interpreter.  (In CPython with the
default ‘--with-pymalloc’ setting, this is allocations made through the
*note PyObject_Malloc(): e64. API.) This can be useful for tracking
memory leaks, especially if automated via a test suite.  (Contributed by
Antoine Pitrou in bpo-13390(1).)

When the Python interpreter starts in *note interactive mode: 443, it
checks for an *note __interactivehook__: 11ca. attribute on the *note
sys: df. module.  If the attribute exists, its value is called with no
arguments just before interactive mode is started.  The check is made
after the *note PYTHONSTARTUP: 1b8. file is read, so it can be set
there.  The *note site: cc. module *note sets it: 11cb. to a function
that enables tab completion and history saving (in ‘~/.python-history’)
if the platform supports *note readline: bf.  If you do not want this
(new) behavior, you can override it in *note PYTHONSTARTUP: 1b8, *note
sitecustomize: cd, or *note usercustomize: 114. by deleting this
attribute from *note sys: df. (or setting it to some other callable).
(Contributed by Éric Araujo and Antoine Pitrou in bpo-5845(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13390

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5845


File: python.info,  Node: tarfile<8>,  Next: textwrap<2>,  Prev: sys<12>,  Up: Improved Modules<9>

1.11.4.53 tarfile
.................

The *note tarfile: e4. module now supports a simple *note Command-Line
Interface: 11cd. when called as a script directly or via ‘-m’.  This can
be used to create and extract tarfile archives.  (Contributed by Berker
Peksag in bpo-13477(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13477


File: python.info,  Node: textwrap<2>,  Next: threading<8>,  Prev: tarfile<8>,  Up: Improved Modules<9>

1.11.4.54 textwrap
..................

The *note TextWrapper: 11cf. class has two new attributes/constructor
arguments: *note max_lines: 11d0, which limits the number of lines in
the output, and *note placeholder: 11d1, which is a string that will
appear at the end of the output if it has been truncated because of
'max_lines'.  Building on these capabilities, a new convenience function
*note shorten(): 11d2. collapses all of the whitespace in the input to
single spaces and produces a single line of a given 'width' that ends
with the 'placeholder' (by default, ‘[...]’).  (Contributed by Antoine
Pitrou and Serhiy Storchaka in bpo-18585(1) and bpo-18725(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18585

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18725


File: python.info,  Node: threading<8>,  Next: traceback<6>,  Prev: textwrap<2>,  Up: Improved Modules<9>

1.11.4.55 threading
...................

The *note Thread: 176. object representing the main thread can be
obtained from the new *note main_thread(): 11d4. function.  In normal
conditions this will be the thread from which the Python interpreter was
started.  (Contributed by Andrew Svetlov in bpo-18882(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18882


File: python.info,  Node: traceback<6>,  Next: types<7>,  Prev: threading<8>,  Up: Improved Modules<9>

1.11.4.56 traceback
...................

A new *note traceback.clear_frames(): 11d6. function takes a traceback
object and clears the local variables in all of the frames it
references, reducing the amount of memory consumed.  (Contributed by
Andrew Kuchling in bpo-1565525(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1565525


File: python.info,  Node: types<7>,  Next: urllib<5>,  Prev: traceback<6>,  Up: Improved Modules<9>

1.11.4.57 types
...............

A new *note DynamicClassAttribute(): 83d. descriptor provides a way to
define an attribute that acts normally when looked up through an
instance object, but which is routed to the 'class' ‘__getattr__’ when
looked up through the class.  This allows one to have properties active
on a class, and have virtual attributes on the class with the same name
(see *note enum: 5a. for an example).  (Contributed by Ethan Furman in
bpo-19030(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19030


File: python.info,  Node: urllib<5>,  Next: unittest<10>,  Prev: types<7>,  Up: Improved Modules<9>

1.11.4.58 urllib
................

*note urllib.request: 111. now supports ‘data:’ URLs via the *note
DataHandler: 11d9. class.  (Contributed by Mathias Panzenböck in
bpo-16423(1).)

The http method that will be used by a *note Request: 11da. class can
now be specified by setting a *note method: 11db. class attribute on the
subclass.  (Contributed by Jason R Coombs in bpo-18978(2).)

*note Request: 11da. objects are now reusable: if the *note full_url:
11dc. or *note data: 11dd. attributes are modified, all relevant
internal properties are updated.  This means, for example, that it is
now possible to use the same *note Request: 11da. object in more than
one *note OpenerDirector.open(): 11de. call with different 'data'
arguments, or to modify a *note Request: 11da.“s ‘url’ rather than
recomputing it from scratch.  There is also a new *note remove_header():
11df. method that can be used to remove headers from a *note Request:
11da.  (Contributed by Alexey Kachayev in bpo-16464(3), Daniel Wozniak
in bpo-17485(4), and Damien Brecht and Senthil Kumaran in bpo-17272(5).)

*note HTTPError: 11e0. objects now have a *note headers: 11e1. attribute
that provides access to the HTTP response headers associated with the
error.  (Contributed by Berker Peksag in bpo-15701(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16423

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18978

   (3) https://bugs.python.org/issue?@action=redirect&bpo=16464

   (4) https://bugs.python.org/issue?@action=redirect&bpo=17485

   (5) https://bugs.python.org/issue?@action=redirect&bpo=17272

   (6) https://bugs.python.org/issue?@action=redirect&bpo=15701


File: python.info,  Node: unittest<10>,  Next: venv<7>,  Prev: urllib<5>,  Up: Improved Modules<9>

1.11.4.59 unittest
..................

The *note TestCase: 2b3. class has a new method, *note subTest(): 11e3,
that produces a context manager whose *note with: 186. block becomes a
«sub-test».  This context manager allows a test method to dynamically
generate subtests by, say, calling the ‘subTest’ context manager inside
a loop.  A single test method can thereby produce an indefinite number
of separately identified and separately counted tests, all of which will
run even if one or more of them fail.  For example:

     class NumbersTest(unittest.TestCase):
         def test_even(self):
             for i in range(6):
                 with self.subTest(i=i):
                     self.assertEqual(i % 2, 0)

will result in six subtests, each identified in the unittest verbose
output with a label consisting of the variable name ‘i’ and a particular
value for that variable (‘i=0’, ‘i=1’, etc).  See *note Distinguishing
test iterations using subtests: 11e4. for the full version of this
example.  (Contributed by Antoine Pitrou in bpo-16997(1).)

*note unittest.main(): 11e5. now accepts an iterable of test names for
'defaultTest', where previously it only accepted a single test name as a
string.  (Contributed by Jyrki Pulliainen in bpo-15132(2).)

If *note SkipTest: 11e6. is raised during test discovery (that is, at
the module level in the test file), it is now reported as a skip instead
of an error.  (Contributed by Zach Ware in bpo-16935(3).)

*note discover(): 11e7. now sorts the discovered files to provide
consistent test ordering.  (Contributed by Martin Melin and Jeff Ramnani
in bpo-16709(4).)

*note TestSuite: ff7. now drops references to tests as soon as the test
has been run, if the test is successful.  On Python interpreters that do
garbage collection, this allows the tests to be garbage collected if
nothing else is holding a reference to the test.  It is possible to
override this behavior by creating a *note TestSuite: ff7. subclass that
defines a custom ‘_removeTestAtIndex’ method.  (Contributed by Tom
Wardill, Matt McClure, and Andrew Svetlov in bpo-11798(5).)

A new test assertion context-manager, *note assertLogs(): a5b, will
ensure that a given block of code emits a log message using the *note
logging: 8b. module.  By default the message can come from any logger
and have a priority of ‘INFO’ or higher, but both the logger name and an
alternative minimum logging level may be specified.  The object returned
by the context manager can be queried for the *note LogRecord: 11e8.s
and/or formatted messages that were logged.  (Contributed by Antoine
Pitrou in bpo-18937(6).)

Test discovery now works with namespace packages (Contributed by Claudiu
Popa in bpo-17457(7).)

*note unittest.mock: 10d. objects now inspect their specification
signatures when matching calls, which means an argument can now be
matched by either position or name, instead of only by position.
(Contributed by Antoine Pitrou in bpo-17015(8).)

*note mock_open(): 11e9. objects now have ‘readline’ and ‘readlines’
methods.  (Contributed by Toshio Kuratomi in bpo-17467(9).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16997

   (2) https://bugs.python.org/issue?@action=redirect&bpo=15132

   (3) https://bugs.python.org/issue?@action=redirect&bpo=16935

   (4) https://bugs.python.org/issue?@action=redirect&bpo=16709

   (5) https://bugs.python.org/issue?@action=redirect&bpo=11798

   (6) https://bugs.python.org/issue?@action=redirect&bpo=18937

   (7) https://bugs.python.org/issue?@action=redirect&bpo=17457

   (8) https://bugs.python.org/issue?@action=redirect&bpo=17015

   (9) https://bugs.python.org/issue?@action=redirect&bpo=17467


File: python.info,  Node: venv<7>,  Next: wave<2>,  Prev: unittest<10>,  Up: Improved Modules<9>

1.11.4.60 venv
..............

*note venv: 117. now includes activation scripts for the ‘csh’ and
‘fish’ shells.  (Contributed by Andrew Svetlov in bpo-15417(1).)

*note EnvBuilder: 571. and the *note create(): 572. convenience function
take a new keyword argument 'with_pip', which defaults to ‘False’, that
controls whether or not *note EnvBuilder: 571. ensures that ‘pip’ is
installed in the virtual environment.  (Contributed by Nick Coghlan in
bpo-19552(2) as part of the PEP 453(3) implementation.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15417

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19552

   (3) https://peps.python.org/pep-0453/


File: python.info,  Node: wave<2>,  Next: weakref<2>,  Prev: venv<7>,  Up: Improved Modules<9>

1.11.4.61 wave
..............

The *note getparams(): 11ec. method now returns a namedtuple rather than
a plain tuple.  (Contributed by Claudiu Popa in bpo-17487(1).)

*note wave.open(): b47. now supports the context management protocol.
(Contributed by Claudiu Popa in bpo-17616(2).)

*note wave: 119. can now *note write output to unseekable files: 11ed.
(Contributed by David Jones, Guilherme Polo, and Serhiy Storchaka in
bpo-5202(3).)

The *note writeframesraw(): 11ee. and *note writeframes(): 11ef. methods
now accept any *note bytes-like object: 193.  (Contributed by Serhiy
Storchaka in bpo-8311(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17487

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17616

   (3) https://bugs.python.org/issue?@action=redirect&bpo=5202

   (4) https://bugs.python.org/issue?@action=redirect&bpo=8311


File: python.info,  Node: weakref<2>,  Next: xml etree<2>,  Prev: wave<2>,  Up: Improved Modules<9>

1.11.4.62 weakref
.................

New *note WeakMethod: 11f1. class simulates weak references to bound
methods.  (Contributed by Antoine Pitrou in bpo-14631(1).)

New *note finalize: c71. class makes it possible to register a callback
to be invoked when an object is garbage collected, without needing to
carefully manage the lifecycle of the weak reference itself.
(Contributed by Richard Oudkerk in bpo-15528(2).)

The callback, if any, associated with a *note ref: 11f2. is now exposed
via the *note __callback__: 11f3. attribute.  (Contributed by Mark
Dickinson in bpo-17643(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14631

   (2) https://bugs.python.org/issue?@action=redirect&bpo=15528

   (3) https://bugs.python.org/issue?@action=redirect&bpo=17643


File: python.info,  Node: xml etree<2>,  Next: zipfile<6>,  Prev: weakref<2>,  Up: Improved Modules<9>

1.11.4.63 xml.etree
...................

A new parser, *note XMLPullParser: 11f5, allows a non-blocking
applications to parse XML documents.  An example can be seen at *note
Pull API for non-blocking parsing: 11f6.  (Contributed by Antoine Pitrou
in bpo-17741(1).)

The *note xml.etree.ElementTree: 12b. *note tostring(): 11f7. and *note
tostringlist(): 11f8. functions, and the *note ElementTree: b49. *note
write(): c8e. method, now have a 'short_empty_elements' *note
keyword-only parameter: 5a5. providing control over whether elements
with no content are written in abbreviated (‘<tag />’) or expanded
(‘<tag></tag>’) form.  (Contributed by Ariel Poliak and Serhiy Storchaka
in bpo-14377(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17741

   (2) https://bugs.python.org/issue?@action=redirect&bpo=14377


File: python.info,  Node: zipfile<6>,  Prev: xml etree<2>,  Up: Improved Modules<9>

1.11.4.64 zipfile
.................

The *note writepy(): 11fa. method of the *note PyZipFile: 11fb. class
has a new 'filterfunc' option that can be used to control which
directories and files are added to the archive.  For example, this could
be used to exclude test files from the archive.  (Contributed by
Christian Tismer in bpo-19274(1).)

The 'allowZip64' parameter to *note ZipFile: 8d4. and *note PyZipFile:
11fb. is now ‘True’ by default.  (Contributed by William Mallard in
bpo-17201(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19274

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17201


File: python.info,  Node: CPython Implementation Changes,  Next: Deprecated<10>,  Prev: Improved Modules<9>,  Up: What’s New In Python 3 4

1.11.5 CPython Implementation Changes
-------------------------------------

* Menu:

* PEP 445; Customization of CPython Memory Allocators: PEP 445 Customization of CPython Memory Allocators.
* PEP 442; Safe Object Finalization: PEP 442 Safe Object Finalization.
* PEP 456; Secure and Interchangeable Hash Algorithm: PEP 456 Secure and Interchangeable Hash Algorithm.
* PEP 436; Argument Clinic: PEP 436 Argument Clinic.
* Other Build and C API Changes::
* Other Improvements: Other Improvements<2>.
* Significant Optimizations::


File: python.info,  Node: PEP 445 Customization of CPython Memory Allocators,  Next: PEP 442 Safe Object Finalization,  Up: CPython Implementation Changes

1.11.5.1 PEP 445: Customization of CPython Memory Allocators
............................................................

PEP 445(1) adds new C level interfaces to customize memory allocation in
the CPython interpreter.

Vedi anche
..........

PEP 445(2) – Add new APIs to customize Python memory allocators

     PEP written and implemented by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0445/

   (2) https://peps.python.org/pep-0445/


File: python.info,  Node: PEP 442 Safe Object Finalization,  Next: PEP 456 Secure and Interchangeable Hash Algorithm,  Prev: PEP 445 Customization of CPython Memory Allocators,  Up: CPython Implementation Changes

1.11.5.2 PEP 442: Safe Object Finalization
..........................................

PEP 442(1) removes the current limitations and quirks of object
finalization in CPython.  With it, objects with *note __del__(): 11ff.
methods, as well as generators with *note finally: 1b0. clauses, can be
finalized when they are part of a reference cycle.

As part of this change, module globals are no longer forcibly set to
*note None: 886. during interpreter shutdown in most cases, instead
relying on the normal operation of the cyclic garbage collector.  This
avoids a whole class of interpreter-shutdown-time errors, usually
involving ‘__del__’ methods, that have plagued Python since the cyclic
GC was first introduced.

Vedi anche
..........

PEP 442(2) – Safe object finalization

     PEP written and implemented by Antoine Pitrou.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0442/

   (2) https://peps.python.org/pep-0442/


File: python.info,  Node: PEP 456 Secure and Interchangeable Hash Algorithm,  Next: PEP 436 Argument Clinic,  Prev: PEP 442 Safe Object Finalization,  Up: CPython Implementation Changes

1.11.5.3 PEP 456: Secure and Interchangeable Hash Algorithm
...........................................................

PEP 456(1) follows up on earlier security fix work done on Python’s hash
algorithm to address certain DOS attacks to which public facing APIs
backed by dictionary lookups may be subject.  (See bpo-14621(2) for the
start of the current round of improvements.)  The PEP unifies CPython’s
hash code to make it easier for a packager to substitute a different
hash algorithm, and switches Python’s default implementation to a
SipHash implementation on platforms that have a 64 bit data type.  Any
performance differences in comparison with the older FNV algorithm are
trivial.

The PEP adds additional fields to the *note sys.hash_info: 1201. named
tuple to describe the hash algorithm in use by the currently executing
binary.  Otherwise, the PEP does not alter any existing CPython APIs.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0456/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=14621


File: python.info,  Node: PEP 436 Argument Clinic,  Next: Other Build and C API Changes,  Prev: PEP 456 Secure and Interchangeable Hash Algorithm,  Up: CPython Implementation Changes

1.11.5.4 PEP 436: Argument Clinic
.................................

«Argument Clinic» ( PEP 436(1)) is now part of the CPython build process
and can be used to simplify the process of defining and maintaining
accurate signatures for builtins and standard library extension modules
implemented in C.

Some standard library extension modules have been converted to use
Argument Clinic in Python 3.4, and *note pydoc: ba. and *note inspect:
82. have been updated accordingly.

It is expected that signature metadata for programmatic introspection
will be added to additional callables implemented in C as part of Python
3.4 maintenance releases.

     Nota: The Argument Clinic PEP is not fully up to date with the
     state of the implementation.  This has been deemed acceptable by
     the release manager and core development team in this case, as
     Argument Clinic will not be made available as a public API for
     third party use in Python 3.4.

Vedi anche
..........

PEP 436(2) – The Argument Clinic DSL

     PEP written and implemented by Larry Hastings.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0436/

   (2) https://peps.python.org/pep-0436/


File: python.info,  Node: Other Build and C API Changes,  Next: Other Improvements<2>,  Prev: PEP 436 Argument Clinic,  Up: CPython Implementation Changes

1.11.5.5 Other Build and C API Changes
......................................

   * The new *note PyType_GetSlot(): a9e. function has been added to the
     stable ABI, allowing retrieval of function pointers from named type
     slots when using the limited API. (Contributed by Martin von Löwis
     in bpo-17162(1).)

   * The new ‘Py_SetStandardStreamEncoding()’ pre-initialization API
     allows applications embedding the CPython interpreter to reliably
     force a particular encoding and error handler for the standard
     streams.  (Contributed by Bastien Montagne and Nick Coghlan in
     bpo-16129(2).)

   * Most Python C APIs that don’t mutate string arguments are now
     correctly marked as accepting ‘const char *’ rather than ‘char *’.
     (Contributed by Serhiy Storchaka in bpo-1772673(3).)

   * A new shell version of ‘python-config’ can be used even when a
     python interpreter is not available (for example, in cross
     compilation scenarios).

   * *note PyUnicode_FromFormat(): 62b. now supports width and precision
     specifications for ‘%s’, ‘%A’, ‘%U’, ‘%V’, ‘%S’, and ‘%R’.
     (Contributed by Ysj Ray and Victor Stinner in bpo-7330(4).)

   * New function *note PyStructSequence_InitType2(): 1204. supplements
     the existing *note PyStructSequence_InitType(): 1205. function.
     The difference is that it returns ‘0’ on success and ‘-1’ on
     failure.

   * The CPython source can now be compiled using the address sanity
     checking features of recent versions of GCC and clang: the false
     alarms in the small object allocator have been silenced.
     (Contributed by Dhiru Kholia in bpo-18596(5).)

   * The Windows build now uses Address Space Layout Randomization(6)
     and Data Execution Prevention(7).  (Contributed by Christian Heimes
     in bpo-16632(8).)

   * New function *note PyObject_LengthHint(): 1206. is the C API
     equivalent of *note operator.length_hint(): 116f.  (Contributed by
     Armin Ronacher in bpo-16148(9).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17162

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16129

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1772673

   (4) https://bugs.python.org/issue?@action=redirect&bpo=7330

   (5) https://bugs.python.org/issue?@action=redirect&bpo=18596

   (6) https://en.wikipedia.org/wiki/Address_space_layout_randomization

   (7) https://en.wikipedia.org/wiki/Data_Execution_Prevention

   (8) https://bugs.python.org/issue?@action=redirect&bpo=16632

   (9) https://bugs.python.org/issue?@action=redirect&bpo=16148


File: python.info,  Node: Other Improvements<2>,  Next: Significant Optimizations,  Prev: Other Build and C API Changes,  Up: CPython Implementation Changes

1.11.5.6 Other Improvements
...........................

   * The *note python: 1209. command has a new *note option: 120a, ‘-I’,
     which causes it to run in «isolated mode», which means that *note
     sys.path: 3e4. contains neither the script’s directory nor the
     user’s ‘site-packages’ directory, and all ‘PYTHON*’ environment
     variables are ignored (it implies both ‘-s’ and ‘-E’).  Other
     restrictions may also be applied in the future, with the goal being
     to isolate the execution of a script from the user’s environment.
     This is appropriate, for example, when Python is used to run a
     system script.  On most POSIX systems it can and should be used in
     the ‘#!’ line of system scripts.  (Contributed by Christian Heimes
     in bpo-16499(1).)

   * Tab-completion is now enabled by default in the interactive
     interpreter on systems that support *note readline: bf.  History is
     also enabled by default, and is written to (and read from) the file
     ‘~/.python-history’.  (Contributed by Antoine Pitrou and Éric
     Araujo in bpo-5845(2).)

   * Invoking the Python interpreter with ‘--version’ now outputs the
     version to standard output instead of standard error
     (bpo-18338(3)).  Similar changes were made to *note argparse: 7.
     (bpo-18920(4)) and other modules that have script-like invocation
     capabilities (bpo-18922(5)).

   * The CPython Windows installer now adds ‘.py’ to the ‘PATHEXT’
     variable when extensions are registered, allowing users to run a
     python script at the windows command prompt by just typing its name
     without the ‘.py’ extension.  (Contributed by Paul Moore in
     bpo-18569(6).)

   * A new ‘make’ target coverage-report(7) will build python, run the
     test suite, and generate an HTML coverage report for the C codebase
     using ‘gcov’ and lcov(8).

   * The ‘-R’ option to the *note python regression test suite: 120b.
     now also checks for memory allocation leaks, using *note
     sys.getallocatedblocks(): 11c9.  (Contributed by Antoine Pitrou in
     bpo-13390(9).)

   * ‘python -m’ now works with namespace packages.

   * The *note stat: d6. module is now implemented in C, which means it
     gets the values for its constants from the C header files, instead
     of having the values hard-coded in the python module as was
     previously the case.

   * Loading multiple python modules from a single OS module (‘.so’,
     ‘.dll’) now works correctly (previously it silently returned the
     first python module in the file).  (Contributed by Václav Šmilauer
     in bpo-16421(10).)

   * A new opcode, ‘LOAD_CLASSDEREF’, has been added to fix a bug in the
     loading of free variables in class bodies that could be triggered
     by certain uses of *note __prepare__: e5a.  (Contributed by
     Benjamin Peterson in bpo-17853(11).)

   * A number of MemoryError-related crashes were identified and fixed
     by Victor Stinner using his PEP 445(12)-based ‘pyfailmalloc’ tool
     (bpo-18408(13), bpo-18520(14)).

   * The ‘pyvenv’ command now accepts a ‘--copies’ option to use copies
     rather than symlinks even on systems where symlinks are the
     default.  (Contributed by Vinay Sajip in bpo-18807(15).)

   * The ‘pyvenv’ command also accepts a ‘--without-pip’ option to
     suppress the otherwise-automatic bootstrapping of pip into the
     virtual environment.  (Contributed by Nick Coghlan in bpo-19552(16)
     as part of the PEP 453(17) implementation.)

   * The encoding name is now optional in the value set for the *note
     PYTHONIOENCODING: 120c. environment variable.  This makes it
     possible to set just the error handler, without changing the
     default encoding.  (Contributed by Serhiy Storchaka in
     bpo-18818(18).)

   * The *note bz2: 14, *note lzma: 8e, and *note gzip: 6b. module
     ‘open’ functions now support ‘x’ (exclusive creation) mode.
     (Contributed by Tim Heaney and Vajrasky Kok in bpo-19201(19),
     bpo-19222(20), and bpo-19223(21).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16499

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5845

   (3) https://bugs.python.org/issue?@action=redirect&bpo=18338

   (4) https://bugs.python.org/issue?@action=redirect&bpo=18920

   (5) https://bugs.python.org/issue?@action=redirect&bpo=18922

   (6) https://bugs.python.org/issue?@action=redirect&bpo=18569

   (7) 
https://devguide.python.org/coverage/#measuring-coverage-of-c-code-with-gcov-and-lcov

   (8) https://github.com/linux-test-project/lcov

   (9) https://bugs.python.org/issue?@action=redirect&bpo=13390

   (10) https://bugs.python.org/issue?@action=redirect&bpo=16421

   (11) https://bugs.python.org/issue?@action=redirect&bpo=17853

   (12) https://peps.python.org/pep-0445/

   (13) https://bugs.python.org/issue?@action=redirect&bpo=18408

   (14) https://bugs.python.org/issue?@action=redirect&bpo=18520

   (15) https://bugs.python.org/issue?@action=redirect&bpo=18807

   (16) https://bugs.python.org/issue?@action=redirect&bpo=19552

   (17) https://peps.python.org/pep-0453/

   (18) https://bugs.python.org/issue?@action=redirect&bpo=18818

   (19) https://bugs.python.org/issue?@action=redirect&bpo=19201

   (20) https://bugs.python.org/issue?@action=redirect&bpo=19222

   (21) https://bugs.python.org/issue?@action=redirect&bpo=19223


File: python.info,  Node: Significant Optimizations,  Prev: Other Improvements<2>,  Up: CPython Implementation Changes

1.11.5.7 Significant Optimizations
..................................

   * The UTF-32 decoder is now 3x to 4x faster.  (Contributed by Serhiy
     Storchaka in bpo-14625(1).)

   * The cost of hash collisions for sets is now reduced.  Each hash
     table probe now checks a series of consecutive, adjacent key/hash
     pairs before continuing to make random probes through the hash
     table.  This exploits cache locality to make collision resolution
     less expensive.  The collision resolution scheme can be described
     as a hybrid of linear probing and open addressing.  The number of
     additional linear probes defaults to nine.  This can be changed at
     compile-time by defining LINEAR_PROBES to be any value.  Set
     LINEAR_PROBES=0 to turn-off linear probing entirely.  (Contributed
     by Raymond Hettinger in bpo-18771(2).)

   * The interpreter starts about 30% faster.  A couple of measures lead
     to the speedup.  The interpreter loads fewer modules on startup,
     e.g.  the *note re: be, *note collections: 1e. and *note locale:
     8a. modules and their dependencies are no longer imported by
     default.  The marshal module has been improved to load compiled
     Python code faster.  (Contributed by Antoine Pitrou, Christian
     Heimes and Victor Stinner in bpo-19219(3), bpo-19218(4),
     bpo-19209(5), bpo-19205(6) and bpo-9548(7).)

   * *note bz2.BZ2File: a68. is now as fast or faster than the Python2
     version for most cases.  *note lzma.LZMAFile: 120e. has also been
     optimized.  (Contributed by Serhiy Storchaka and Nadeem Vawda in
     bpo-16034(8).)

   * *note random.getrandbits(): 120f. is 20%-40% faster for small
     integers (the most common use case).  (Contributed by Serhiy
     Storchaka in bpo-16674(9).)

   * By taking advantage of the new storage format for strings, pickling
     of strings is now significantly faster.  (Contributed by Victor
     Stinner and Antoine Pitrou in bpo-15596(10).)

   * A performance issue in ‘io.FileIO.readall()’ has been solved.  This
     particularly affects Windows, and significantly speeds up the case
     of piping significant amounts of data through *note subprocess: dc.
     (Contributed by Richard Oudkerk in bpo-15758(11).)

   * *note html.escape(): 1210. is now 10x faster.  (Contributed by Matt
     Bryant in bpo-18020(12).)

   * On Windows, the native ‘VirtualAlloc’ is now used instead of the
     CRT ‘malloc’ in ‘obmalloc’.  Artificial benchmarks show about a 3%
     memory savings.

   * *note os.urandom(): 747. now uses a lazily opened persistent file
     descriptor so as to avoid using many file descriptors when run in
     parallel from multiple threads.  (Contributed by Antoine Pitrou in
     bpo-18756(13).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14625

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18771

   (3) https://bugs.python.org/issue?@action=redirect&bpo=19219

   (4) https://bugs.python.org/issue?@action=redirect&bpo=19218

   (5) https://bugs.python.org/issue?@action=redirect&bpo=19209

   (6) https://bugs.python.org/issue?@action=redirect&bpo=19205

   (7) https://bugs.python.org/issue?@action=redirect&bpo=9548

   (8) https://bugs.python.org/issue?@action=redirect&bpo=16034

   (9) https://bugs.python.org/issue?@action=redirect&bpo=16674

   (10) https://bugs.python.org/issue?@action=redirect&bpo=15596

   (11) https://bugs.python.org/issue?@action=redirect&bpo=15758

   (12) https://bugs.python.org/issue?@action=redirect&bpo=18020

   (13) https://bugs.python.org/issue?@action=redirect&bpo=18756


File: python.info,  Node: Deprecated<10>,  Next: Removed<10>,  Prev: CPython Implementation Changes,  Up: What’s New In Python 3 4

1.11.6 Deprecated
-----------------

This section covers various APIs and other features that have been
deprecated in Python 3.4, and will be removed in Python 3.5 or later.
In most (but not all) cases, using the deprecated APIs will produce a
*note DeprecationWarning: 1a3. when the interpreter is run with
deprecation warnings enabled (for example, by using ‘-Wd’).

* Menu:

* Deprecations in the Python API::
* Deprecated Features::


File: python.info,  Node: Deprecations in the Python API,  Next: Deprecated Features,  Up: Deprecated<10>

1.11.6.1 Deprecations in the Python API
.......................................

   * As mentioned in *note PEP 451; A ModuleSpec Type for the Import
     System: 10de, a number of *note importlib: 7b. methods and
     functions are deprecated: ‘importlib.find_loader()’ is replaced by
     *note importlib.util.find_spec(): 5af.;
     ‘importlib.machinery.PathFinder.find_module()’ is replaced by *note
     importlib.machinery.PathFinder.find_spec(): 1213.;
     ‘importlib.abc.MetaPathFinder.find_module()’ is replaced by *note
     importlib.abc.MetaPathFinder.find_spec(): a6a.;
     ‘importlib.abc.PathEntryFinder.find_loader()’ and ‘find_module()’
     are replaced by *note importlib.abc.PathEntryFinder.find_spec():
     a6e.; all of the ‘XXXLoader’ ABC ‘load_module’ methods
     (‘importlib.abc.Loader.load_module()’,
     ‘importlib.abc.InspectLoader.load_module()’,
     ‘importlib.abc.FileLoader.load_module()’,
     ‘importlib.abc.SourceLoader.load_module()’) should no longer be
     implemented, instead loaders should implement an ‘exec_module’
     method (*note importlib.abc.Loader.exec_module(): a6c, *note
     importlib.abc.InspectLoader.exec_module(): 1214. *note
     importlib.abc.SourceLoader.exec_module(): 1215.) and let the import
     system take care of the rest; and
     ‘importlib.abc.Loader.module_repr()’,
     ‘importlib.util.module_for_loader()’,
     ‘importlib.util.set_loader()’, and ‘importlib.util.set_package()’
     are no longer needed because their functions are now handled
     automatically by the import system.

   * The ‘imp’ module is pending deprecation.  To keep compatibility
     with Python 2/3 code bases, the module’s removal is currently not
     scheduled.

   * The ‘formatter’ module is pending deprecation and is slated for
     removal in Python 3.6.

   * ‘MD5’ as the default 'digestmod' for the *note hmac.new(): c98.
     function is deprecated.  Python 3.6 will require an explicit digest
     name or constructor as 'digestmod' argument.

   * The internal ‘Netrc’ class in the *note ftplib: 62. module has been
     documented as deprecated in its docstring for quite some time.  It
     now emits a *note DeprecationWarning: 1a3. and will be removed
     completely in Python 3.5.

   * The undocumented 'endtime' argument to *note
     subprocess.Popen.wait(): ee2. should not have been exposed and is
     hopefully not in use; it is deprecated and will mostly likely be
     removed in Python 3.5.

   * The 'strict' argument of *note HTMLParser: a79. is deprecated.

   * The *note plistlib: b0. ‘readPlist()’, ‘writePlist()’,
     ‘readPlistFromBytes()’, and ‘writePlistToBytes()’ functions are
     deprecated in favor of the corresponding new functions *note
     load(): b4a, *note dump(): b4c, *note loads(): b4b, and *note
     dumps(): b4d.  ‘Data()’ is deprecated in favor of just using the
     *note bytes: 192. constructor.

   * The *note sysconfig: e1. key ‘SO’ is deprecated, it has been
     replaced by ‘EXT_SUFFIX’.

   * The ‘U’ mode accepted by various ‘open’ functions is deprecated.
     In Python3 it does not do anything useful, and should be replaced
     by appropriate uses of *note io.TextIOWrapper: 9c0. (if needed) and
     its 'newline' argument.

   * The 'parser' argument of *note xml.etree.ElementTree.iterparse():
     57a. has been deprecated, as has the 'html' argument of *note
     XMLParser(): c4b.  To prepare for the removal of the latter, all
     arguments to ‘XMLParser’ should be passed by keyword.


File: python.info,  Node: Deprecated Features,  Prev: Deprecations in the Python API,  Up: Deprecated<10>

1.11.6.2 Deprecated Features
............................

   * Running *note IDLE — Python editor and shell: 1217. with the ‘-n’
     flag (no subprocess) is deprecated.  However, the feature will not
     be removed until bpo-18823(1) is resolved.

   * The site module adding a «site-python» directory to sys.path, if it
     exists, is deprecated (bpo-19375(2)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18823

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19375


File: python.info,  Node: Removed<10>,  Next: Porting to Python 3 4,  Prev: Deprecated<10>,  Up: What’s New In Python 3 4

1.11.7 Removed
--------------

* Menu:

* Operating Systems No Longer Supported::
* API and Feature Removals: API and Feature Removals<5>.
* Code Cleanups::


File: python.info,  Node: Operating Systems No Longer Supported,  Next: API and Feature Removals<5>,  Up: Removed<10>

1.11.7.1 Operating Systems No Longer Supported
..............................................

Support for the following operating systems has been removed from the
source and build tools:

   * OS/2 (bpo-16135(1)).

   * Windows 2000 (changeset e52df05b496a).

   * Windows systems where ‘COMSPEC’ points to ‘command.com’
     (bpo-14470(2)).

   * VMS (bpo-16136(3)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16135

   (2) https://bugs.python.org/issue?@action=redirect&bpo=14470

   (3) https://bugs.python.org/issue?@action=redirect&bpo=16136


File: python.info,  Node: API and Feature Removals<5>,  Next: Code Cleanups,  Prev: Operating Systems No Longer Supported,  Up: Removed<10>

1.11.7.2 API and Feature Removals
.................................

The following obsolete and previously deprecated APIs and features have
been removed:

   * The unmaintained ‘Misc/TextMate’ and ‘Misc/vim’ directories have
     been removed (see the devguide(1) for suggestions on what to use
     instead).

   * The ‘SO’ makefile macro is removed (it was replaced by the
     ‘SHLIB_SUFFIX’ and ‘EXT_SUFFIX’ macros) (bpo-16754(2)).

   * The ‘PyThreadState.tick_counter’ field has been removed; its value
     has been meaningless since Python 3.2, when the «new GIL» was
     introduced (bpo-19199(3)).

   * ‘PyLoader’ and ‘PyPycLoader’ have been removed from *note
     importlib: 7b.  (Contributed by Taras Lyapun in bpo-15641(4).)

   * The 'strict' argument to *note HTTPConnection: d37. and *note
     HTTPSConnection: d38. has been removed.  HTTP 0.9-style «Simple
     Responses» are no longer supported.

   * The deprecated *note urllib.request.Request: 11da. getter and
     setter methods ‘add_data’, ‘has_data’, ‘get_data’, ‘get_type’,
     ‘get_host’, ‘get_selector’, ‘set_proxy’, ‘get_origin_req_host’, and
     ‘is_unverifiable’ have been removed (use direct attribute access
     instead).

   * Support for loading the deprecated ‘TYPE_INT64’ has been removed
     from *note marshal: 91.  (Contributed by Dan Riti in bpo-15480(5).)

   * *note inspect.Signature: 4e4.: positional-only parameters are now
     required to have a valid name.

   * *note object.__format__(): 832. no longer accepts non-empty format
     strings, it now raises a *note TypeError: 198. instead.  Using a
     non-empty string has been deprecated since Python 3.2.  This change
     has been made to prevent a situation where previously working (but
     incorrect) code would start failing if an object gained a
     __format__ method, which means that your code may now raise a *note
     TypeError: 198. if you are using an ‘'s'’ format code with objects
     that do not have a __format__ method that handles it.  See
     bpo-7994(6) for background.

   * ‘difflib.SequenceMatcher.isbjunk()’ and
     ‘difflib.SequenceMatcher.isbpopular()’ were deprecated in 3.2, and
     have now been removed: use ‘x in sm.bjunk’ and ‘x in sm.bpopular’,
     where 'sm' is a *note SequenceMatcher: 121b. object (bpo-13248(7)).

   ---------- Footnotes ----------

   (1) https://devguide.python.org

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16754

   (3) https://bugs.python.org/issue?@action=redirect&bpo=19199

   (4) https://bugs.python.org/issue?@action=redirect&bpo=15641

   (5) https://bugs.python.org/issue?@action=redirect&bpo=15480

   (6) https://bugs.python.org/issue?@action=redirect&bpo=7994

   (7) https://bugs.python.org/issue?@action=redirect&bpo=13248


File: python.info,  Node: Code Cleanups,  Prev: API and Feature Removals<5>,  Up: Removed<10>

1.11.7.3 Code Cleanups
......................

   * The unused and undocumented internal ‘Scanner’ class has been
     removed from the *note pydoc: ba. module.

   * The private and effectively unused ‘_gestalt’ module has been
     removed, along with the private *note platform: af. functions
     ‘_mac_ver_lookup’, ‘_mac_ver_gstalt’, and ‘_bcd2str’, which would
     only have ever been called on badly broken OSX systems (see
     bpo-18393(1)).

   * The hardcoded copies of certain *note stat: d6. constants that were
     included in the *note tarfile: e4. module namespace have been
     removed.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18393


File: python.info,  Node: Porting to Python 3 4,  Next: Changed in 3 4 3,  Prev: Removed<10>,  Up: What’s New In Python 3 4

1.11.8 Porting to Python 3.4
----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code.

* Menu:

* Changes in “python” Command Behavior: Changes in “python” Command Behavior<2>.
* Changes in the Python API: Changes in the Python API<10>.
* Changes in the C API: Changes in the C API<9>.


File: python.info,  Node: Changes in “python” Command Behavior<2>,  Next: Changes in the Python API<10>,  Up: Porting to Python 3 4

1.11.8.1 Changes in “python” Command Behavior
.............................................

   * In a posix shell, setting the ‘PATH’ environment variable to an
     empty value is equivalent to not setting it at all.  However,
     setting *note PYTHONPATH: 121f. to an empty value was 'not'
     equivalent to not setting it at all: setting *note PYTHONPATH:
     121f. to an empty value was equivalent to setting it to ‘.’, which
     leads to confusion when reasoning by analogy to how ‘PATH’ works.
     The behavior now conforms to the posix convention for ‘PATH’.

   * The [X refs, Y blocks] output of a debug (‘--with-pydebug’) build
     of the CPython interpreter is now off by default.  It can be
     re-enabled using the ‘-X showrefcount’ option.  (Contributed by
     Ezio Melotti in bpo-17323(1).)

   * The python command and most stdlib scripts (as well as *note
     argparse: 7.) now output ‘--version’ information to ‘stdout’
     instead of ‘stderr’ (for issue list see *note Other Improvements:
     1208. above).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17323


File: python.info,  Node: Changes in the Python API<10>,  Next: Changes in the C API<9>,  Prev: Changes in “python” Command Behavior<2>,  Up: Porting to Python 3 4

1.11.8.2 Changes in the Python API
..................................

   * The ABCs defined in *note importlib.abc: 7c. now either raise the
     appropriate exception or return a default value instead of raising
     *note NotImplementedError: 36b. blindly.  This will only affect
     code calling *note super(): 1a6. and falling through all the way to
     the ABCs.  For compatibility, catch both *note NotImplementedError:
     36b. or the appropriate exception as needed.

   * The module type now initializes the *note __package__: 323. and
     *note __loader__: 33b. attributes to ‘None’ by default.  To
     determine if these attributes were set in a backwards-compatible
     fashion, use e.g.  ‘getattr(module, '__loader__', None) is not
     None’.  (bpo-17115(1).)

   * ‘importlib.util.module_for_loader()’ now sets ‘__loader__’ and
     ‘__package__’ unconditionally to properly support reloading.  If
     this is not desired then you will need to set these attributes
     manually.  You can use ‘importlib.util.module_to_load()’ for module
     management.

   * Import now resets relevant attributes (e.g.  ‘__name__’,
     ‘__loader__’, ‘__package__’, ‘__file__’, ‘__cached__’)
     unconditionally when reloading.  Note that this restores a pre-3.3
     behavior in that it means a module is re-found when re-loaded
     (bpo-19413(2)).

   * Frozen packages no longer set ‘__path__’ to a list containing the
     package name, they now set it to an empty list.  The previous
     behavior could cause the import system to do the wrong thing on
     submodule imports if there was also a directory with the same name
     as the frozen package.  The correct way to determine if a module is
     a package or not is to use ‘hasattr(module, '__path__')’
     (bpo-18065(3)).

   * Frozen modules no longer define a ‘__file__’ attribute.  It’s
     semantically incorrect for frozen modules to set the attribute as
     they are not loaded from any explicit location.  If you must know
     that a module comes from frozen code then you can see if the
     module’s ‘__spec__.location’ is set to ‘'frozen'’, check if the
     loader is a subclass of *note importlib.machinery.FrozenImporter:
     1221, or if Python 2 compatibility is necessary you can use
     ‘imp.is_frozen()’.

   * *note py_compile.compile(): c1c. now raises *note FileExistsError:
     1222. if the file path it would write to is a symlink or a
     non-regular file.  This is to act as a warning that import will
     overwrite those files with a regular file regardless of what type
     of file path they were originally.

   * *note importlib.abc.SourceLoader.get_source(): 1223. no longer
     raises *note ImportError: 65b. when the source code being loaded
     triggers a *note SyntaxError: 18e. or *note UnicodeDecodeError:
     c0a.  As *note ImportError: 65b. is meant to be raised only when
     source code cannot be found but it should, it was felt to be
     over-reaching/overloading of that meaning when the source code is
     found but improperly structured.  If you were catching ImportError
     before and wish to continue to ignore syntax or decoding issues,
     catch all three exceptions now.

   * *note functools.update_wrapper(): 1224. and *note
     functools.wraps(): 115f. now correctly set the ‘__wrapped__’
     attribute to the function being wrapped, even if that function also
     had its ‘__wrapped__’ attribute set.  This means ‘__wrapped__’
     attributes now correctly link a stack of decorated functions rather
     than every ‘__wrapped__’ attribute in the chain referring to the
     innermost function.  Introspection libraries that assumed the
     previous behaviour was intentional can use *note inspect.unwrap():
     115e. to access the first function in the chain that has no
     ‘__wrapped__’ attribute.

   * *note inspect.getfullargspec(): 942. has been reimplemented on top
     of *note inspect.signature(): 22f. and hence handles a much wider
     variety of callable objects than it did in the past.  It is
     expected that additional builtin and extension module callables
     will gain signature metadata over the course of the Python 3.4
     series.  Code that assumes that *note inspect.getfullargspec():
     942. will fail on non-Python callables may need to be adjusted
     accordingly.

   * *note importlib.machinery.PathFinder: 1225. now passes on the
     current working directory to objects in *note sys.path_hooks: 1226.
     for the empty string.  This results in *note
     sys.path_importer_cache: 7fb. never containing ‘''’, thus iterating
     through *note sys.path_importer_cache: 7fb. based on *note
     sys.path: 3e4. will not find all keys.  A module’s ‘__file__’ when
     imported in the current working directory will also now have an
     absolute path, including when using ‘-m’ with the interpreter
     (except for ‘__main__.__file__’ when a script has been executed
     directly using a relative path) (Contributed by Brett Cannon in
     bpo-18416(4)).  is specified on the command-line) (bpo-18416(5)).

   * The removal of the 'strict' argument to *note HTTPConnection: d37.
     and *note HTTPSConnection: d38. changes the meaning of the
     remaining arguments if you are specifying them positionally rather
     than by keyword.  If you’ve been paying attention to deprecation
     warnings your code should already be specifying any additional
     arguments via keywords.

   * Strings between ‘from __future__ import ...’ statements now
     'always' raise a *note SyntaxError: 18e.  Previously if there was
     no leading docstring, an interstitial string would sometimes be
     ignored.  This brings CPython into compliance with the language
     spec; Jython and PyPy already were.  (bpo-17434(6)).

   * *note ssl.SSLSocket.getpeercert(): 11ba. and *note
     ssl.SSLSocket.do_handshake(): 106f. now raise an *note OSError:
     2c0. with ‘ENOTCONN’ when the ‘SSLSocket’ is not connected, instead
     of the previous behavior of raising an *note AttributeError: 5f0.
     In addition, *note getpeercert(): 11ba. will raise a *note
     ValueError: 2ec. if the handshake has not yet been done.

   * *note base64.b32decode(): 1227. now raises a *note binascii.Error:
     1228. when the input string contains non-b32-alphabet characters,
     instead of a *note TypeError: 198.  This particular *note
     TypeError: 198. was missed when the other *note TypeError: 198.s
     were converted.  (Contributed by Serhiy Storchaka in bpo-18011(7).)
     Note: this change was also inadvertently applied in Python 3.3.3.

   * The ‘file’ attribute is now automatically closed when the creating
     ‘cgi.FieldStorage’ instance is garbage collected.  If you were
     pulling the file object out separately from the ‘cgi.FieldStorage’
     instance and not keeping the instance alive, then you should either
     store the entire ‘cgi.FieldStorage’ instance or read the contents
     of the file before the ‘cgi.FieldStorage’ instance is garbage
     collected.

   * Calling ‘read’ or ‘write’ on a closed SSL socket now raises an
     informative *note ValueError: 2ec. rather than the previous more
     mysterious *note AttributeError: 5f0. (bpo-9177(8)).

   * *note slice.indices(): 1229. no longer produces an *note
     OverflowError: a83. for huge values.  As a consequence of this fix,
     *note slice.indices(): 1229. now raises a *note ValueError: 2ec. if
     given a negative length; previously it returned nonsense values
     (bpo-14794(9)).

   * The *note complex: 197. constructor, unlike the *note cmath: 19.
     functions, was incorrectly accepting *note float: 196. values if an
     object’s ‘__complex__’ special method returned one.  This now
     raises a *note TypeError: 198.  (bpo-16290(10).)

   * The *note int: 19b. constructor in 3.2 and 3.3 erroneously accepts
     *note float: 196. values for the 'base' parameter.  It is unlikely
     anyone was doing this, but if so, it will now raise a *note
     TypeError: 198. (bpo-16772(11)).

   * Defaults for keyword-only arguments are now evaluated 'after'
     defaults for regular keyword arguments, instead of before.
     Hopefully no one wrote any code that depends on the previous buggy
     behavior (bpo-16967(12)).

   * Stale thread states are now cleared after *note fork(): 4b6.  This
     may cause some system resources to be released that previously were
     incorrectly kept perpetually alive (for example, database
     connections kept in thread-local storage).  (bpo-17094(13).)

   * Parameter names in ‘__annotations__’ dicts are now mangled
     properly, similarly to *note __kwdefaults__: 122a.  (Contributed by
     Yury Selivanov in bpo-20625(14).)

   * *note hashlib.hash.name: 1149. now always returns the identifier in
     lower case.  Previously some builtin hashes had uppercase names,
     but now that it is a formal public interface the naming has been
     made consistent (bpo-18532(15)).

   * Because *note unittest.TestSuite: ff7. now drops references to
     tests after they are run, test harnesses that reuse a *note
     TestSuite: ff7. to re-run a set of tests may fail.  Test suites
     should not be re-used in this fashion since it means state is
     retained between test runs, breaking the test isolation that *note
     unittest: 10c. is designed to provide.  However, if the lack of
     isolation is considered acceptable, the old behavior can be
     restored by creating a *note TestSuite: ff7. subclass that defines
     a ‘_removeTestAtIndex’ method that does nothing (see *note
     TestSuite.__iter__(): 122b.) (bpo-11798(16)).

   * *note unittest: 10c. now uses *note argparse: 7. for command line
     parsing.  There are certain invalid command forms that used to work
     that are no longer allowed; in theory this should not cause
     backward compatibility issues since the disallowed command forms
     didn’t make any sense and are unlikely to be in use.

   * The *note re.split(): 5a2, *note re.findall(): 122c, and *note
     re.sub(): 5a3. functions, and the *note group(): 122d. and *note
     groups(): 122e. methods of ‘match’ objects now always return a
     'bytes' object when the string to be matched is a *note bytes-like
     object: 193.  Previously the return type matched the input type, so
     if your code was depending on the return value being, say, a
     ‘bytearray’, you will need to change your code.

   * ‘audioop’ functions now raise an error immediately if passed string
     input, instead of failing randomly later on (bpo-16685(17)).

   * The new 'convert_charrefs' argument to *note HTMLParser: a79.
     currently defaults to ‘False’ for backward compatibility, but will
     eventually be changed to default to ‘True’.  It is recommended that
     you add this keyword, with the appropriate value, to any *note
     HTMLParser: a79. calls in your code (bpo-13633(18)).

   * Since the 'digestmod' argument to the *note hmac.new(): c98.
     function will in the future have no default, all calls to *note
     hmac.new(): c98. should be changed to explicitly specify a
     'digestmod' (bpo-17276(19)).

   * Calling *note sysconfig.get_config_var(): 174. with the ‘SO’ key,
     or looking ‘SO’ up in the results of a call to *note
     sysconfig.get_config_vars(): 298. is deprecated.  This key should
     be replaced by ‘EXT_SUFFIX’ or ‘SHLIB_SUFFIX’, depending on the
     context (bpo-19555(20)).

   * Any calls to ‘open’ functions that specify ‘U’ should be modified.
     ‘U’ is ineffective in Python3 and will eventually raise an error if
     used.  Depending on the function, the equivalent of its old Python2
     behavior can be achieved using either a 'newline' argument, or if
     necessary by wrapping the stream in *note TextIOWrapper: 9c0. to
     use its 'newline' argument (bpo-15204(21)).

   * If you use ‘pyvenv’ in a script and desire that pip 'not' be
     installed, you must add ‘--without-pip’ to your command invocation.

   * The default behavior of *note json.dump(): f42. and *note
     json.dumps(): f43. when an indent is specified has changed: it no
     longer produces trailing spaces after the item separating commas at
     the ends of lines.  This will matter only if you have tests that
     are doing white-space-sensitive comparisons of such output
     (bpo-16333(22)).

   * *note doctest: 3e. now looks for doctests in extension module
     ‘__doc__’ strings, so if your doctest test discovery includes
     extension modules that have things that look like doctests in them
     you may see test failures you’ve never seen before when running
     your tests (bpo-3158(23)).

   * The *note collections.abc: 1f. module has been slightly refactored
     as part of the Python startup improvements.  As a consequence of
     this, it is no longer the case that importing *note collections:
     1e. automatically imports *note collections.abc: 1f.  If your
     program depended on the (undocumented) implicit import, you will
     need to add an explicit ‘import collections.abc’ (bpo-20784(24)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17115

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19413

   (3) https://bugs.python.org/issue?@action=redirect&bpo=18065

   (4) https://bugs.python.org/issue?@action=redirect&bpo=18416

   (5) https://bugs.python.org/issue?@action=redirect&bpo=18416

   (6) https://bugs.python.org/issue?@action=redirect&bpo=17434

   (7) https://bugs.python.org/issue?@action=redirect&bpo=18011

   (8) https://bugs.python.org/issue?@action=redirect&bpo=9177

   (9) https://bugs.python.org/issue?@action=redirect&bpo=14794

   (10) https://bugs.python.org/issue?@action=redirect&bpo=16290

   (11) https://bugs.python.org/issue?@action=redirect&bpo=16772

   (12) https://bugs.python.org/issue?@action=redirect&bpo=16967

   (13) https://bugs.python.org/issue?@action=redirect&bpo=17094

   (14) https://bugs.python.org/issue?@action=redirect&bpo=20625

   (15) https://bugs.python.org/issue?@action=redirect&bpo=18532

   (16) https://bugs.python.org/issue?@action=redirect&bpo=11798

   (17) https://bugs.python.org/issue?@action=redirect&bpo=16685

   (18) https://bugs.python.org/issue?@action=redirect&bpo=13633

   (19) https://bugs.python.org/issue?@action=redirect&bpo=17276

   (20) https://bugs.python.org/issue?@action=redirect&bpo=19555

   (21) https://bugs.python.org/issue?@action=redirect&bpo=15204

   (22) https://bugs.python.org/issue?@action=redirect&bpo=16333

   (23) https://bugs.python.org/issue?@action=redirect&bpo=3158

   (24) https://bugs.python.org/issue?@action=redirect&bpo=20784


File: python.info,  Node: Changes in the C API<9>,  Prev: Changes in the Python API<10>,  Up: Porting to Python 3 4

1.11.8.3 Changes in the C API
.............................

   * *note PyEval_EvalFrameEx(): 1230, *note PyObject_Repr(): 1231, and
     *note PyObject_Str(): 1232, along with some other internal C APIs,
     now include a debugging assertion that ensures they are not used in
     situations where they may silently discard a currently active
     exception.  In cases where discarding the active exception is
     expected and desired (for example, because it has already been
     saved locally with *note PyErr_Fetch(): 428. or is being
     deliberately replaced with a different exception), an explicit
     *note PyErr_Clear(): 1233. call will be needed to avoid triggering
     the assertion when invoking these operations (directly or
     indirectly) and running against a version of Python that is
     compiled with assertions enabled.

   * *note PyErr_SetImportError(): f3b. now sets *note TypeError: 198.
     when its 'msg' argument is not set.  Previously only ‘NULL’ was
     returned with no exception set.

   * The result of the *note PyOS_ReadlineFunctionPointer: 7a6. callback
     must now be a string allocated by *note PyMem_RawMalloc(): 631. or
     *note PyMem_RawRealloc(): 633, or ‘NULL’ if an error occurred,
     instead of a string allocated by *note PyMem_Malloc(): e62. or
     *note PyMem_Realloc(): 1234. (bpo-16742(1))

   * *note PyThread_set_key_value(): 43b. now always set the value.  In
     Python 3.3, the function did nothing if the key already exists (if
     the current value is a non-‘NULL’ pointer).

   * The ‘f_tstate’ (thread state) field of the *note PyFrameObject:
     98d. structure has been removed to fix a bug: see bpo-14432(2) for
     the rationale.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16742

   (2) https://bugs.python.org/issue?@action=redirect&bpo=14432


File: python.info,  Node: Changed in 3 4 3,  Prev: Porting to Python 3 4,  Up: What’s New In Python 3 4

1.11.9 Changed in 3.4.3
-----------------------

* Menu:

* PEP 476; Enabling certificate verification by default for stdlib http clients: PEP 476 Enabling certificate verification by default for stdlib http clients.


File: python.info,  Node: PEP 476 Enabling certificate verification by default for stdlib http clients,  Up: Changed in 3 4 3

1.11.9.1 PEP 476: Enabling certificate verification by default for stdlib http clients
......................................................................................

*note http.client: 73. and modules which use it, such as *note
urllib.request: 111. and *note xmlrpc.client: 134, will now verify that
the server presents a certificate which is signed by a CA in the
platform trust store and whose hostname matches the hostname being
requested by default, significantly improving security for many
applications.

For applications which require the old previous behavior, they can pass
an alternate context:

     import urllib.request
     import ssl

     # This disables all verification
     context = ssl._create_unverified_context()

     # This allows using a specific certificate for the host, which doesn't need
     # to be in the trust store
     context = ssl.create_default_context(cafile="/path/to/file.crt")

     urllib.request.urlopen("https://invalid-cert", context=context)


File: python.info,  Node: What’s New In Python 3 3,  Next: What’s New In Python 3 2,  Prev: What’s New In Python 3 4,  Up: Novità in Python

1.12 What’s New In Python 3.3
=============================

This article explains the new features in Python 3.3, compared to 3.2.
Python 3.3 was released on September 29, 2012.  For full details, see
the changelog(1).

Vedi anche
..........

PEP 398(2) - Python 3.3 Release Schedule

* Menu:

* Summary – Release highlights: Summary – Release highlights<8>.
* PEP 405; Virtual Environments: PEP 405 Virtual Environments.
* PEP 420; Implicit Namespace Packages: PEP 420 Implicit Namespace Packages.
* PEP 3118; New memoryview implementation and buffer protocol documentation: PEP 3118 New memoryview implementation and buffer protocol documentation.
* PEP 393; Flexible String Representation: PEP 393 Flexible String Representation.
* PEP 397; Python Launcher for Windows: PEP 397 Python Launcher for Windows.
* PEP 3151; Reworking the OS and IO exception hierarchy: PEP 3151 Reworking the OS and IO exception hierarchy.
* PEP 380; Syntax for Delegating to a Subgenerator: PEP 380 Syntax for Delegating to a Subgenerator.
* PEP 409; Suppressing exception context: PEP 409 Suppressing exception context.
* PEP 414; Explicit Unicode literals: PEP 414 Explicit Unicode literals.
* PEP 3155; Qualified name for classes and functions: PEP 3155 Qualified name for classes and functions.
* PEP 412; Key-Sharing Dictionary: PEP 412 Key-Sharing Dictionary.
* PEP 362; Function Signature Object: PEP 362 Function Signature Object.
* PEP 421; Adding sys.implementation: PEP 421 Adding sys implementation.
* Using importlib as the Implementation of Import::
* Other Language Changes: Other Language Changes<10>.
* A Finer-Grained Import Lock::
* Builtin functions and types::
* New Modules: New Modules<10>.
* Improved Modules: Improved Modules<10>.
* Optimizations: Optimizations<10>.
* Build and C API Changes: Build and C API Changes<4>.
* Deprecated: Deprecated<11>.
* Porting to Python 3.3: Porting to Python 3 3.

   ---------- Footnotes ----------

   (1) https://docs.python.org/3.3/whatsnew/changelog.html

   (2) https://peps.python.org/pep-0398/


File: python.info,  Node: Summary – Release highlights<8>,  Next: PEP 405 Virtual Environments,  Up: What’s New In Python 3 3

1.12.1 Summary – Release highlights
-----------------------------------

New syntax features:

   * New ‘yield from’ expression for *note generator delegation: 123c.

   * The ‘u'unicode'’ syntax is accepted again for *note str: 169.
     objects.

New library modules:

   * *note faulthandler: 5c. (helps debugging low-level crashes)

   * *note ipaddress: 84. (high-level objects representing IP addresses
     and masks)

   * *note lzma: 8e. (compress data using the XZ / LZMA algorithm)

   * *note unittest.mock: 10d. (replace parts of your system under test
     with mock objects)

   * *note venv: 117. (Python *note virtual environments: 123d, as in
     the popular ‘virtualenv’ package)

New built-in features:

   * Reworked *note I/O exception hierarchy: 123e.

Implementation improvements:

   * Rewritten *note import machinery: 123f. based on *note importlib:
     7b.

   * More compact *note unicode strings: 1240.

   * More compact *note attribute dictionaries: 1241.

Significantly Improved Library Modules:

   * C Accelerator for the *note decimal: 1242. module.

   * Better unicode handling in the *note email: 1243. module (*note
     provisional: 1244.).

Security improvements:

   * Hash randomization is switched on by default.

Please read on for a comprehensive list of user-facing changes.


File: python.info,  Node: PEP 405 Virtual Environments,  Next: PEP 420 Implicit Namespace Packages,  Prev: Summary – Release highlights<8>,  Up: What’s New In Python 3 3

1.12.2 PEP 405: Virtual Environments
------------------------------------

Virtual environments help create separate Python setups while sharing a
system-wide base install, for ease of maintenance.  Virtual environments
have their own set of private site packages (i.e.  locally installed
libraries), and are optionally segregated from the system-wide site
packages.  Their concept and implementation are inspired by the popular
‘virtualenv’ third-party package, but benefit from tighter integration
with the interpreter core.

This PEP adds the *note venv: 117. module for programmatic access, and
the ‘pyvenv’ script for command-line access and administration.  The
Python interpreter checks for a ‘pyvenv.cfg’, file whose existence
signals the base of a virtual environment’s directory tree.

Vedi anche
..........

PEP 405(1) - Python Virtual Environments

     PEP written by Carl Meyer; implementation by Carl Meyer and Vinay
     Sajip

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0405/


File: python.info,  Node: PEP 420 Implicit Namespace Packages,  Next: PEP 3118 New memoryview implementation and buffer protocol documentation,  Prev: PEP 405 Virtual Environments,  Up: What’s New In Python 3 3

1.12.3 PEP 420: Implicit Namespace Packages
-------------------------------------------

Native support for package directories that don’t require ‘__init__.py’
marker files and can automatically span multiple path segments (inspired
by various third party approaches to namespace packages, as described in
PEP 420(1))

Vedi anche
..........

PEP 420(2) - Implicit Namespace Packages

     PEP written by Eric V. Smith; implementation by Eric V. Smith and
     Barry Warsaw

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0420/

   (2) https://peps.python.org/pep-0420/


File: python.info,  Node: PEP 3118 New memoryview implementation and buffer protocol documentation,  Next: PEP 393 Flexible String Representation,  Prev: PEP 420 Implicit Namespace Packages,  Up: What’s New In Python 3 3

1.12.4 PEP 3118: New memoryview implementation and buffer protocol documentation
--------------------------------------------------------------------------------

The implementation of PEP 3118(1) has been significantly improved.

The new memoryview implementation comprehensively fixes all ownership
and lifetime issues of dynamically allocated fields in the Py_buffer
struct that led to multiple crash reports.  Additionally, several
functions that crashed or returned incorrect results for non-contiguous
or multi-dimensional input have been fixed.

The memoryview object now has a PEP-3118 compliant getbufferproc() that
checks the consumer’s request type.  Many new features have been added,
most of them work in full generality for non-contiguous arrays and
arrays with suboffsets.

The documentation has been updated, clearly spelling out
responsibilities for both exporters and consumers.  Buffer request flags
are grouped into basic and compound flags.  The memory layout of
non-contiguous and multi-dimensional NumPy-style arrays is explained.

* Menu:

* Features::
* API changes::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3118/


File: python.info,  Node: Features,  Next: API changes,  Up: PEP 3118 New memoryview implementation and buffer protocol documentation

1.12.4.1 Features
.................

   * All native single character format specifiers in struct module
     syntax (optionally prefixed with “@”) are now supported.

   * With some restrictions, the cast() method allows changing of format
     and shape of C-contiguous arrays.

   * Multi-dimensional list representations are supported for any array
     type.

   * Multi-dimensional comparisons are supported for any array type.

   * One-dimensional memoryviews of hashable (read-only) types with
     formats B, b or c are now hashable.  (Contributed by Antoine Pitrou
     in bpo-13411(1).)

   * Arbitrary slicing of any 1-D arrays type is supported.  For
     example, it is now possible to reverse a memoryview in 'O'(1) by
     using a negative step.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13411


File: python.info,  Node: API changes,  Prev: Features,  Up: PEP 3118 New memoryview implementation and buffer protocol documentation

1.12.4.2 API changes
....................

   * The maximum number of dimensions is officially limited to 64.

   * The representation of empty shape, strides and suboffsets is now an
     empty tuple instead of ‘None’.

   * Accessing a memoryview element with format “B” (unsigned bytes) now
     returns an integer (in accordance with the struct module syntax).
     For returning a bytes object the view must be cast to “c” first.

   * memoryview comparisons now use the logical structure of the
     operands and compare all array elements by value.  All format
     strings in struct module syntax are supported.  Views with
     unrecognised format strings are still permitted, but will always
     compare as unequal, regardless of view contents.

   * For further changes see *note Build and C API Changes: 124b. and
     *note Porting C code: 124c.

(Contributed by Stefan Krah in bpo-10181(1).)

Vedi anche
..........

PEP 3118(2) - Revising the Buffer Protocol

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10181

   (2) https://peps.python.org/pep-3118/


File: python.info,  Node: PEP 393 Flexible String Representation,  Next: PEP 397 Python Launcher for Windows,  Prev: PEP 3118 New memoryview implementation and buffer protocol documentation,  Up: What’s New In Python 3 3

1.12.5 PEP 393: Flexible String Representation
----------------------------------------------

The Unicode string type is changed to support multiple internal
representations, depending on the character with the largest Unicode
ordinal (1, 2, or 4 bytes) in the represented string.  This allows a
space-efficient representation in common cases, but gives access to full
UCS-4 on all systems.  For compatibility with existing APIs, several
representations may exist in parallel; over time, this compatibility
should be phased out.

On the Python side, there should be no downside to this change.

On the C API side, PEP 393(1) is fully backward compatible.  The legacy
API should remain available at least five years.  Applications using the
legacy API will not fully benefit of the memory reduction, or - worse -
may use a bit more memory, because Python may have to maintain two
versions of each string (in the legacy format and in the new efficient
storage).

* Menu:

* Functionality::
* Performance and resource usage::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0393/


File: python.info,  Node: Functionality,  Next: Performance and resource usage,  Up: PEP 393 Flexible String Representation

1.12.5.1 Functionality
......................

Changes introduced by PEP 393(1) are the following:

   * Python now always supports the full range of Unicode code points,
     including non-BMP ones (i.e.  from ‘U+0000’ to ‘U+10FFFF’).  The
     distinction between narrow and wide builds no longer exists and
     Python now behaves like a wide build, even under Windows.

   * With the death of narrow builds, the problems specific to narrow
     builds have also been fixed, for example:

        * *note len(): 841. now always returns 1 for non-BMP characters,
          so ‘len('\U0010FFFF') == 1’;

        * surrogate pairs are not recombined in string literals, so
          ‘'\uDBFF\uDFFF' != '\U0010FFFF'’;

        * indexing or slicing non-BMP characters returns the expected
          value, so ‘'\U0010FFFF'[0]’ now returns ‘'\U0010FFFF'’ and not
          ‘'\uDBFF'’;

        * all other functions in the standard library now correctly
          handle non-BMP code points.

   * The value of *note sys.maxunicode: 124f. is now always ‘1114111’
     (‘0x10FFFF’ in hexadecimal).  The ‘PyUnicode_GetMax()’ function
     still returns either ‘0xFFFF’ or ‘0x10FFFF’ for backward
     compatibility, and it should not be used with the new Unicode API
     (see bpo-13054(2)).

   * The ‘./configure’ flag ‘--with-wide-unicode’ has been removed.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0393/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13054


File: python.info,  Node: Performance and resource usage,  Prev: Functionality,  Up: PEP 393 Flexible String Representation

1.12.5.2 Performance and resource usage
.......................................

The storage of Unicode strings now depends on the highest code point in
the string:

   * pure ASCII and Latin1 strings (‘U+0000-U+00FF’) use 1 byte per code
     point;

   * BMP strings (‘U+0000-U+FFFF’) use 2 bytes per code point;

   * non-BMP strings (‘U+10000-U+10FFFF’) use 4 bytes per code point.

The net effect is that for most applications, memory usage of string
storage should decrease significantly - especially compared to former
wide unicode builds - as, in many cases, strings will be pure ASCII even
in international contexts (because many strings store non-human language
data, such as XML fragments, HTTP headers, JSON-encoded data, etc.).  We
also hope that it will, for the same reasons, increase CPU cache
efficiency on non-trivial applications.  The memory usage of Python 3.3
is two to three times smaller than Python 3.2, and a little bit better
than Python 2.7, on a Django benchmark (see the PEP for details).

Vedi anche
..........

PEP 393(1) - Flexible String Representation

     PEP written by Martin von Löwis; implementation by Torsten Becker
     and Martin von Löwis.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0393/


File: python.info,  Node: PEP 397 Python Launcher for Windows,  Next: PEP 3151 Reworking the OS and IO exception hierarchy,  Prev: PEP 393 Flexible String Representation,  Up: What’s New In Python 3 3

1.12.6 PEP 397: Python Launcher for Windows
-------------------------------------------

The Python 3.3 Windows installer now includes a ‘py’ launcher
application that can be used to launch Python applications in a version
independent fashion.

This launcher is invoked implicitly when double-clicking ‘*.py’ files.
If only a single Python version is installed on the system, that version
will be used to run the file.  If multiple versions are installed, the
most recent version is used by default, but this can be overridden by
including a Unix-style «shebang line» in the Python script.

The launcher can also be used explicitly from the command line as the
‘py’ application.  Running ‘py’ follows the same version selection rules
as implicitly launching scripts, but a more specific version can be
selected by passing appropriate arguments (such as ‘-3’ to request
Python 3 when Python 2 is also installed, or ‘-2.6’ to specifically
request an earlier Python version when a more recent version is
installed).

In addition to the launcher, the Windows installer now includes an
option to add the newly installed Python to the system PATH.
(Contributed by Brian Curtin in bpo-3561(1).)

Vedi anche
..........

PEP 397(2) - Python Launcher for Windows

     PEP written by Mark Hammond and Martin v.  Löwis; implementation by
     Vinay Sajip.

Launcher documentation: *note Python install manager: 7db.

Installer PATH modification: *note Python install manager: 1253.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=3561

   (2) https://peps.python.org/pep-0397/


File: python.info,  Node: PEP 3151 Reworking the OS and IO exception hierarchy,  Next: PEP 380 Syntax for Delegating to a Subgenerator,  Prev: PEP 397 Python Launcher for Windows,  Up: What’s New In Python 3 3

1.12.7 PEP 3151: Reworking the OS and IO exception hierarchy
------------------------------------------------------------

The hierarchy of exceptions raised by operating system errors is now
both simplified and finer-grained.

You don’t have to worry anymore about choosing the appropriate exception
type between *note OSError: 2c0, *note IOError: 1255, *note
EnvironmentError: 1256, *note WindowsError: 1257, ‘mmap.error’, *note
socket.error: 1258. or *note select.error: 1259.  All these exception
types are now only one: *note OSError: 2c0.  The other names are kept as
aliases for compatibility reasons.

Also, it is now easier to catch a specific error condition.  Instead of
inspecting the ‘errno’ attribute (or ‘args[0]’) for a particular
constant from the *note errno: 5b. module, you can catch the adequate
*note OSError: 2c0. subclass.  The available subclasses are the
following:

   * *note BlockingIOError: 235.

   * *note ChildProcessError: 125a.

   * *note ConnectionError: 100d.

   * *note FileExistsError: 1222.

   * *note FileNotFoundError: 264.

   * *note InterruptedError: f8a.

   * *note IsADirectoryError: 125b.

   * *note NotADirectoryError: 125c.

   * *note PermissionError: f40.

   * *note ProcessLookupError: 125d.

   * *note TimeoutError: a38.

And the *note ConnectionError: 100d. itself has finer-grained
subclasses:

   * *note BrokenPipeError: 125e.

   * *note ConnectionAbortedError: 125f.

   * *note ConnectionRefusedError: 1260.

   * *note ConnectionResetError: 1261.

Thanks to the new exceptions, common usages of the *note errno: 5b. can
now be avoided.  For example, the following code written for Python 3.2:

     from errno import ENOENT, EACCES, EPERM

     try:
         with open("document.txt") as f:
             content = f.read()
     except IOError as err:
         if err.errno == ENOENT:
             print("document.txt file is missing")
         elif err.errno in (EACCES, EPERM):
             print("You are not allowed to read document.txt")
         else:
             raise

can now be written without the *note errno: 5b. import and without
manual inspection of exception attributes:

     try:
         with open("document.txt") as f:
             content = f.read()
     except FileNotFoundError:
         print("document.txt file is missing")
     except PermissionError:
         print("You are not allowed to read document.txt")

Vedi anche
..........

PEP 3151(1) - Reworking the OS and IO Exception Hierarchy

     PEP written and implemented by Antoine Pitrou

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3151/


File: python.info,  Node: PEP 380 Syntax for Delegating to a Subgenerator,  Next: PEP 409 Suppressing exception context,  Prev: PEP 3151 Reworking the OS and IO exception hierarchy,  Up: What’s New In Python 3 3

1.12.8 PEP 380: Syntax for Delegating to a Subgenerator
-------------------------------------------------------

PEP 380 adds the ‘yield from’ expression, allowing a *note generator:
1263. to delegate part of its operations to another generator.  This
allows a section of code containing *note yield: bc4. to be factored out
and placed in another generator.  Additionally, the subgenerator is
allowed to return with a value, and the value is made available to the
delegating generator.

While designed primarily for use in delegating to a subgenerator, the
‘yield from’ expression actually allows delegation to arbitrary
subiterators.

For simple iterators, ‘yield from iterable’ is essentially just a
shortened form of ‘for item in iterable: yield item’:

     >>> def g(x):
     ...     yield from range(x, 0, -1)
     ...     yield from range(x)
     ...
     >>> list(g(5))
     [5, 4, 3, 2, 1, 0, 1, 2, 3, 4]

However, unlike an ordinary loop, ‘yield from’ allows subgenerators to
receive sent and thrown values directly from the calling scope, and
return a final value to the outer generator:

     >>> def accumulate():
     ...     tally = 0
     ...     while 1:
     ...         next = yield
     ...         if next is None:
     ...             return tally
     ...         tally += next
     ...
     >>> def gather_tallies(tallies):
     ...     while 1:
     ...         tally = yield from accumulate()
     ...         tallies.append(tally)
     ...
     >>> tallies = []
     >>> acc = gather_tallies(tallies)
     >>> next(acc)  # Ensure the accumulator is ready to accept values
     >>> for i in range(4):
     ...     acc.send(i)
     ...
     >>> acc.send(None)  # Finish the first tally
     >>> for i in range(5):
     ...     acc.send(i)
     ...
     >>> acc.send(None)  # Finish the second tally
     >>> tallies
     [6, 10]

The main principle driving this change is to allow even generators that
are designed to be used with the ‘send’ and ‘throw’ methods to be split
into multiple subgenerators as easily as a single large function can be
split into multiple subfunctions.

Vedi anche
..........

PEP 380(1) - Syntax for Delegating to a Subgenerator

     PEP written by Greg Ewing; implementation by Greg Ewing, integrated
     into 3.3 by Renaud Blanch, Ryan Kelly and Nick Coghlan;
     documentation by Zbigniew Jędrzejewski-Szmek and Nick Coghlan

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0380/


File: python.info,  Node: PEP 409 Suppressing exception context,  Next: PEP 414 Explicit Unicode literals,  Prev: PEP 380 Syntax for Delegating to a Subgenerator,  Up: What’s New In Python 3 3

1.12.9 PEP 409: Suppressing exception context
---------------------------------------------

PEP 409 introduces new syntax that allows the display of the chained
exception context to be disabled.  This allows cleaner error messages in
applications that convert between exception types:

     >>> class D:
     ...     def __init__(self, extra):
     ...         self._extra_attributes = extra
     ...     def __getattr__(self, attr):
     ...         try:
     ...             return self._extra_attributes[attr]
     ...         except KeyError:
     ...             raise AttributeError(attr) from None
     ...
     >>> D({}).x
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
       File "<stdin>", line 8, in __getattr__
     AttributeError: x

Without the ‘from None’ suffix to suppress the cause, the original
exception would be displayed by default:

     >>> class C:
     ...     def __init__(self, extra):
     ...         self._extra_attributes = extra
     ...     def __getattr__(self, attr):
     ...         try:
     ...             return self._extra_attributes[attr]
     ...         except KeyError:
     ...             raise AttributeError(attr)
     ...
     >>> C({}).x
     Traceback (most recent call last):
       File "<stdin>", line 6, in __getattr__
     KeyError: 'x'

     During handling of the above exception, another exception occurred:

     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
       File "<stdin>", line 8, in __getattr__
     AttributeError: x

No debugging capability is lost, as the original exception context
remains available if needed (for example, if an intervening library has
incorrectly suppressed valuable underlying details):

     >>> try:
     ...     D({}).x
     ... except AttributeError as exc:
     ...     print(repr(exc.__context__))
     ...
     KeyError('x',)

Vedi anche
..........

PEP 409(1) - Suppressing exception context

     PEP written by Ethan Furman; implemented by Ethan Furman and Nick
     Coghlan.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0409/


File: python.info,  Node: PEP 414 Explicit Unicode literals,  Next: PEP 3155 Qualified name for classes and functions,  Prev: PEP 409 Suppressing exception context,  Up: What’s New In Python 3 3

1.12.10 PEP 414: Explicit Unicode literals
------------------------------------------

To ease the transition from Python 2 for Unicode aware Python
applications that make heavy use of Unicode literals, Python 3.3 once
again supports the «‘u’» prefix for string literals.  This prefix has no
semantic significance in Python 3, it is provided solely to reduce the
number of purely mechanical changes in migrating to Python 3, making it
easier for developers to focus on the more significant semantic changes
(such as the stricter default separation of binary and text data).

Vedi anche
..........

PEP 414(1) - Explicit Unicode literals

     PEP written by Armin Ronacher.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0414/


File: python.info,  Node: PEP 3155 Qualified name for classes and functions,  Next: PEP 412 Key-Sharing Dictionary,  Prev: PEP 414 Explicit Unicode literals,  Up: What’s New In Python 3 3

1.12.11 PEP 3155: Qualified name for classes and functions
----------------------------------------------------------

Functions and class objects have a new *note __qualname__: 1267.
attribute representing the «path» from the module top-level to their
definition.  For global functions and classes, this is the same as *note
__name__: 1268.  For other functions and classes, it provides better
information about where they were actually defined, and how they might
be accessible from the global scope.

Example with (non-bound) methods:

     >>> class C:
     ...     def meth(self):
     ...         pass
     ...
     >>> C.meth.__name__
     'meth'
     >>> C.meth.__qualname__
     'C.meth'

Example with nested classes:

     >>> class C:
     ...     class D:
     ...         def meth(self):
     ...             pass
     ...
     >>> C.D.__name__
     'D'
     >>> C.D.__qualname__
     'C.D'
     >>> C.D.meth.__name__
     'meth'
     >>> C.D.meth.__qualname__
     'C.D.meth'

Example with nested functions:

     >>> def outer():
     ...     def inner():
     ...         pass
     ...     return inner
     ...
     >>> outer().__name__
     'inner'
     >>> outer().__qualname__
     'outer.<locals>.inner'

The string representation of those objects is also changed to include
the new, more precise information:

     >>> str(C.D)
     "<class '__main__.C.D'>"
     >>> str(C.D.meth)
     '<function C.D.meth at 0x7f46b9fe31e0>'

Vedi anche
..........

PEP 3155(1) - Qualified name for classes and functions

     PEP written and implemented by Antoine Pitrou.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3155/


File: python.info,  Node: PEP 412 Key-Sharing Dictionary,  Next: PEP 362 Function Signature Object,  Prev: PEP 3155 Qualified name for classes and functions,  Up: What’s New In Python 3 3

1.12.12 PEP 412: Key-Sharing Dictionary
---------------------------------------

Dictionaries used for the storage of objects” attributes are now able to
share part of their internal storage between each other (namely, the
part which stores the keys and their respective hashes).  This reduces
the memory consumption of programs creating many instances of
non-builtin types.

Vedi anche
..........

PEP 412(1) - Key-Sharing Dictionary

     PEP written and implemented by Mark Shannon.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0412/


File: python.info,  Node: PEP 362 Function Signature Object,  Next: PEP 421 Adding sys implementation,  Prev: PEP 412 Key-Sharing Dictionary,  Up: What’s New In Python 3 3

1.12.13 PEP 362: Function Signature Object
------------------------------------------

A new function *note inspect.signature(): 22f. makes introspection of
python callables easy and straightforward.  A broad range of callables
is supported: python functions, decorated or not, classes, and *note
functools.partial(): 217. objects.  New classes *note inspect.Signature:
4e4, *note inspect.Parameter: 4e5. and *note inspect.BoundArguments:
126b. hold information about the call signatures, such as, annotations,
default values, parameters kinds, and bound arguments, which
considerably simplifies writing decorators and any code that validates
or amends calling signatures or arguments.

Vedi anche
..........

PEP 362(1): - Function Signature Object

     PEP written by Brett Cannon, Yury Selivanov, Larry Hastings, Jiwon
     Seo; implemented by Yury Selivanov.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0362/


File: python.info,  Node: PEP 421 Adding sys implementation,  Next: Using importlib as the Implementation of Import,  Prev: PEP 362 Function Signature Object,  Up: What’s New In Python 3 3

1.12.14 PEP 421: Adding sys.implementation
------------------------------------------

A new attribute on the *note sys: df. module exposes details specific to
the implementation of the currently running interpreter.  The initial
set of attributes on *note sys.implementation: 73c. are ‘name’,
‘version’, ‘hexversion’, and ‘cache_tag’.

The intention of ‘sys.implementation’ is to consolidate into one
namespace the implementation-specific data used by the standard library.
This allows different Python implementations to share a single standard
library code base much more easily.  In its initial state,
‘sys.implementation’ holds only a small portion of the
implementation-specific data.  Over time that ratio will shift in order
to make the standard library more portable.

One example of improved standard library portability is ‘cache_tag’.  As
of Python 3.3, ‘sys.implementation.cache_tag’ is used by *note
importlib: 7b. to support PEP 3147(1) compliance.  Any Python
implementation that uses ‘importlib’ for its built-in import system may
use ‘cache_tag’ to control the caching behavior for modules.

* Menu:

* SimpleNamespace::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3147/


File: python.info,  Node: SimpleNamespace,  Up: PEP 421 Adding sys implementation

1.12.14.1 SimpleNamespace
.........................

The implementation of ‘sys.implementation’ also introduces a new type to
Python: *note types.SimpleNamespace: 4e6.  In contrast to a
mapping-based namespace, like *note dict: 183, ‘SimpleNamespace’ is
attribute-based, like *note object: c80.  However, unlike ‘object’,
‘SimpleNamespace’ instances are writable.  This means that you can add,
remove, and modify the namespace through normal attribute access.

Vedi anche
..........

PEP 421(1) - Adding sys.implementation

     PEP written and implemented by Eric Snow.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0421/


File: python.info,  Node: Using importlib as the Implementation of Import,  Next: Other Language Changes<10>,  Prev: PEP 421 Adding sys implementation,  Up: What’s New In Python 3 3

1.12.15 Using importlib as the Implementation of Import
-------------------------------------------------------

bpo-2377(1) - Replace __import__ w/ importlib.__import__ bpo-13959(2) -
Re-implement parts of ‘imp’ in pure Python bpo-14605(3) - Make import
machinery explicit bpo-14646(4) - Require loaders set __loader__ and
__package__

The *note __import__(): ad3. function is now powered by *note
importlib.__import__(): 126f.  This work leads to the completion of
«phase 2» of PEP 302(5).  There are multiple benefits to this change.
First, it has allowed for more of the machinery powering import to be
exposed instead of being implicit and hidden within the C code.  It also
provides a single implementation for all Python VMs supporting Python
3.3 to use, helping to end any VM-specific deviations in import
semantics.  And finally it eases the maintenance of import, allowing for
future growth to occur.

For the common user, there should be no visible change in semantics.
For those whose code currently manipulates import or calls import
programmatically, the code changes that might possibly be required are
covered in the *note Porting Python code: 1270. section of this
document.

* Menu:

* New APIs::
* Visible Changes::

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=2377

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13959

   (3) https://bugs.python.org/issue?@action=redirect&bpo=14605

   (4) https://bugs.python.org/issue?@action=redirect&bpo=14646

   (5) https://peps.python.org/pep-0302/


File: python.info,  Node: New APIs,  Next: Visible Changes,  Up: Using importlib as the Implementation of Import

1.12.15.1 New APIs
..................

One of the large benefits of this work is the exposure of what goes into
making the import statement work.  That means the various importers that
were once implicit are now fully exposed as part of the *note importlib:
7b. package.

The abstract base classes defined in *note importlib.abc: 7c. have been
expanded to properly delineate between *note meta path finders: 1272.
and *note path entry finders: 1273. by introducing *note
importlib.abc.MetaPathFinder: a70. and *note
importlib.abc.PathEntryFinder: a71, respectively.  The old ABC of
‘importlib.abc.Finder’ is now only provided for backwards-compatibility
and does not enforce any method requirements.

In terms of finders, *note importlib.machinery.FileFinder: 1274. exposes
the mechanism used to search for source and bytecode files of a module.
Previously this class was an implicit member of *note sys.path_hooks:
1226.

For loaders, the new abstract base class *note importlib.abc.FileLoader:
1275. helps write a loader that uses the file system as the storage
mechanism for a module’s code.  The loader for source files (*note
importlib.machinery.SourceFileLoader: 1276.), sourceless bytecode files
(*note importlib.machinery.SourcelessFileLoader: 1277.), and extension
modules (*note importlib.machinery.ExtensionFileLoader: eb0.) are now
available for direct use.

*note ImportError: 65b. now has ‘name’ and ‘path’ attributes which are
set when there is relevant data to provide.  The message for failed
imports will also provide the full name of the module now instead of
just the tail end of the module’s name.

The *note importlib.invalidate_caches(): e0c. function will now call the
method with the same name on all finders cached in *note
sys.path_importer_cache: 7fb. to help clean up any stored state as
necessary.


File: python.info,  Node: Visible Changes,  Prev: New APIs,  Up: Using importlib as the Implementation of Import

1.12.15.2 Visible Changes
.........................

For potential required changes to code, see the *note Porting Python
code: 1270. section.

Beyond the expanse of what *note importlib: 7b. now exposes, there are
other visible changes to import.  The biggest is that *note
sys.meta_path: f29. and *note sys.path_hooks: 1226. now store all of the
meta path finders and path entry hooks used by import.  Previously the
finders were implicit and hidden within the C code of import instead of
being directly exposed.  This means that one can now easily remove or
change the order of the various finders to fit one’s needs.

Another change is that all modules have a ‘__loader__’ attribute,
storing the loader used to create the module.  PEP 302(1) has been
updated to make this attribute mandatory for loaders to implement, so in
the future once 3rd-party loaders have been updated people will be able
to rely on the existence of the attribute.  Until such time, though,
import is setting the module post-load.

Loaders are also now expected to set the ‘__package__’ attribute from
PEP 366(2).  Once again, import itself is already setting this on all
loaders from *note importlib: 7b. and import itself is setting the
attribute post-load.

‘None’ is now inserted into *note sys.path_importer_cache: 7fb. when no
finder can be found on *note sys.path_hooks: 1226.  Since
‘imp.NullImporter’ is not directly exposed on *note sys.path_hooks:
1226. it could no longer be relied upon to always be available to use as
a value representing no finder found.

All other changes relate to semantic changes which should be taken into
consideration when updating code for Python 3.3, and thus should be read
about in the *note Porting Python code: 1270. section of this document.

(Implementation by Brett Cannon)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0302/

   (2) https://peps.python.org/pep-0366/


File: python.info,  Node: Other Language Changes<10>,  Next: A Finer-Grained Import Lock,  Prev: Using importlib as the Implementation of Import,  Up: What’s New In Python 3 3

1.12.16 Other Language Changes
------------------------------

Some smaller changes made to the core Python language are:

   * Added support for Unicode name aliases and named sequences.  Both
     *note unicodedata.lookup(): 127a. and ‘'\N{...}'’ now resolve name
     aliases, and *note unicodedata.lookup(): 127a. resolves named
     sequences too.

     (Contributed by Ezio Melotti in bpo-12753(1).)

   * Unicode database updated to UCD version 6.1.0

   * Equality comparisons on *note range(): b3f. objects now return a
     result reflecting the equality of the underlying sequences
     generated by those range objects.  (bpo-13201(2))

   * The ‘count()’, ‘find()’, ‘rfind()’, ‘index()’ and ‘rindex()’
     methods of *note bytes: 192. and *note bytearray: 344. objects now
     accept an integer between 0 and 255 as their first argument.

     (Contributed by Petri Lehtinen in bpo-12170(3).)

   * The ‘rjust()’, ‘ljust()’, and ‘center()’ methods of *note bytes:
     192. and *note bytearray: 344. now accept a *note bytearray: 344.
     for the ‘fill’ argument.  (Contributed by Petri Lehtinen in
     bpo-12380(4).)

   * New methods have been added to *note list: 24d. and *note
     bytearray: 344.: ‘copy()’ and ‘clear()’ (bpo-10516(5)).
     Consequently, *note MutableSequence: 4c0. now also defines a
     ‘clear()’ method (bpo-11388(6)).

   * Raw bytes literals can now be written ‘rb"..."’ as well as
     ‘br"..."’.

     (Contributed by Antoine Pitrou in bpo-13748(7).)

   * *note dict.setdefault(): 127b. now does only one lookup for the
     given key, making it atomic when used with built-in types.

     (Contributed by Filip Gruszczyński in bpo-13521(8).)

   * The error messages produced when a function call does not match the
     function signature have been significantly improved.

     (Contributed by Benjamin Peterson.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12753

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13201

   (3) https://bugs.python.org/issue?@action=redirect&bpo=12170

   (4) https://bugs.python.org/issue?@action=redirect&bpo=12380

   (5) https://bugs.python.org/issue?@action=redirect&bpo=10516

   (6) https://bugs.python.org/issue?@action=redirect&bpo=11388

   (7) https://bugs.python.org/issue?@action=redirect&bpo=13748

   (8) https://bugs.python.org/issue?@action=redirect&bpo=13521


File: python.info,  Node: A Finer-Grained Import Lock,  Next: Builtin functions and types,  Prev: Other Language Changes<10>,  Up: What’s New In Python 3 3

1.12.17 A Finer-Grained Import Lock
-----------------------------------

Previous versions of CPython have always relied on a global import lock.
This led to unexpected annoyances, such as deadlocks when importing a
module would trigger code execution in a different thread as a
side-effect.  Clumsy workarounds were sometimes employed, such as the
*note PyImport_ImportModuleNoBlock(): 3db. C API function.

In Python 3.3, importing a module takes a per-module lock.  This
correctly serializes importation of a given module from multiple threads
(preventing the exposure of incompletely initialized modules), while
eliminating the aforementioned annoyances.

(Contributed by Antoine Pitrou in bpo-9260(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9260


File: python.info,  Node: Builtin functions and types,  Next: New Modules<10>,  Prev: A Finer-Grained Import Lock,  Up: What’s New In Python 3 3

1.12.18 Builtin functions and types
-----------------------------------

   * *note open(): 316. gets a new 'opener' parameter: the underlying
     file descriptor for the file object is then obtained by calling
     'opener' with ('file', 'flags').  It can be used to use custom
     flags like *note os.O_CLOEXEC: 127e. for example.  The ‘'x'’ mode
     was added: open for exclusive creation, failing if the file already
     exists.

   * *note print(): 1177.: added the 'flush' keyword argument.  If the
     'flush' keyword argument is true, the stream is forcibly flushed.

   * *note hash(): 802.: hash randomization is enabled by default, see
     *note object.__hash__(): cf5. and *note PYTHONHASHSEED: 127f.

   * The *note str: 169. type gets a new *note casefold(): fd8. method:
     return a casefolded copy of the string, casefolded strings may be
     used for caseless matching.  For example, ‘'ß'.casefold()’ returns
     ‘'ss'’.

   * The sequence documentation has been substantially rewritten to
     better explain the binary/text sequence distinction and to provide
     specific documentation sections for the individual builtin sequence
     types (bpo-4966(1)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4966


File: python.info,  Node: New Modules<10>,  Next: Improved Modules<10>,  Prev: Builtin functions and types,  Up: What’s New In Python 3 3

1.12.19 New Modules
-------------------

* Menu:

* faulthandler: faulthandler<5>.
* ipaddress: ipaddress<6>.
* lzma: lzma<2>.


File: python.info,  Node: faulthandler<5>,  Next: ipaddress<6>,  Up: New Modules<10>

1.12.19.1 faulthandler
......................

This new debug module *note faulthandler: 5c. contains functions to dump
Python tracebacks explicitly, on a fault (a crash like a segmentation
fault), after a timeout, or on a user signal.  Call *note
faulthandler.enable(): 20f. to install fault handlers for the *note
SIGSEGV: 1282, *note SIGFPE: 1283, *note SIGABRT: 1284, *note SIGBUS:
1285, and *note SIGILL: 1286. signals.  You can also enable them at
startup by setting the *note PYTHONFAULTHANDLER: 1287. environment
variable or by using *note -X: 16f. ‘faulthandler’ command line option.

Example of a segmentation fault on Linux:

     $ python -q -X faulthandler
     >>> import ctypes
     >>> ctypes.string_at(0)
     Fatal Python error: Segmentation fault

     Current thread 0x00007fb899f39700:
       File "/home/python/cpython/Lib/ctypes/__init__.py", line 486 in string_at
       File "<stdin>", line 1 in <module>
     Segmentation fault


File: python.info,  Node: ipaddress<6>,  Next: lzma<2>,  Prev: faulthandler<5>,  Up: New Modules<10>

1.12.19.2 ipaddress
...................

The new *note ipaddress: 84. module provides tools for creating and
manipulating objects representing IPv4 and IPv6 addresses, networks and
interfaces (i.e.  an IP address associated with a specific IP subnet).

(Contributed by Google and Peter Moody in PEP 3144(1).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3144/


File: python.info,  Node: lzma<2>,  Prev: ipaddress<6>,  Up: New Modules<10>

1.12.19.3 lzma
..............

The newly added *note lzma: 8e. module provides data compression and
decompression using the LZMA algorithm, including support for the ‘.xz’
and ‘.lzma’ file formats.

(Contributed by Nadeem Vawda and Per Øyvind Karlsen in bpo-6715(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6715


File: python.info,  Node: Improved Modules<10>,  Next: Optimizations<10>,  Prev: New Modules<10>,  Up: What’s New In Python 3 3

1.12.20 Improved Modules
------------------------

* Menu:

* abc: abc<2>.
* array: array<5>.
* base64: base64<5>.
* binascii: binascii<3>.
* bz2: bz2<2>.
* codecs: codecs<2>.
* collections: collections<7>.
* contextlib: contextlib<7>.
* crypt: crypt<2>.
* curses: curses<6>.
* datetime: datetime<7>.
* decimal: decimal<4>.
* email: email<6>.
* ftplib: ftplib<3>.
* functools: functools<7>.
* gc: gc<7>.
* hmac: hmac<5>.
* http: http<5>.
* html: html<2>.
* imaplib: imaplib<4>.
* inspect: inspect<10>.
* io: io<8>.
* itertools: itertools<7>.
* logging: logging<7>.
* math: math<9>.
* mmap: mmap<4>.
* multiprocessing: multiprocessing<9>.
* nntplib: nntplib<2>.
* os: os<13>.
* pdb: pdb<9>.
* pickle: pickle<6>.
* pydoc: pydoc<6>.
* re: re<10>.
* sched::
* select: select<2>.
* shlex: shlex<3>.
* shutil: shutil<7>.
* signal: signal<4>.
* smtpd: smtpd<4>.
* smtplib: smtplib<4>.
* socket: socket<11>.
* socketserver: socketserver<3>.
* sqlite3: sqlite3<11>.
* ssl: ssl<12>.
* stat: stat<2>.
* struct: struct<4>.
* subprocess: subprocess<6>.
* sys: sys<13>.
* tarfile: tarfile<9>.
* tempfile: tempfile<4>.
* textwrap: textwrap<3>.
* threading: threading<9>.
* time: time<8>.
* types: types<8>.
* unittest: unittest<11>.
* urllib: urllib<6>.
* webbrowser: webbrowser<4>.
* xml.etree.ElementTree: xml etree ElementTree<2>.
* zlib: zlib<3>.


File: python.info,  Node: abc<2>,  Next: array<5>,  Up: Improved Modules<10>

1.12.20.1 abc
.............

Improved support for abstract base classes containing descriptors
composed with abstract methods.  The recommended approach to declaring
abstract descriptors is now to provide ‘__isabstractmethod__’ as a
dynamically updated property.  The built-in descriptors have been
updated accordingly.

   * *note abc.abstractproperty: 128c. has been deprecated, use *note
     property: 4b4. with *note abc.abstractmethod(): 128d. instead.

   * *note abc.abstractclassmethod: 128e. has been deprecated, use *note
     classmethod: 48f. with *note abc.abstractmethod(): 128d. instead.

   * *note abc.abstractstaticmethod: 128f. has been deprecated, use
     *note staticmethod: 453. with *note abc.abstractmethod(): 128d.
     instead.

(Contributed by Darren Dale in bpo-11610(1).)

*note abc.ABCMeta.register(): 1290. now returns the registered subclass,
which means it can now be used as a class decorator (bpo-10868(2)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11610

   (2) https://bugs.python.org/issue?@action=redirect&bpo=10868


File: python.info,  Node: array<5>,  Next: base64<5>,  Prev: abc<2>,  Up: Improved Modules<10>

1.12.20.2 array
...............

The *note array: 8. module supports the long long type using ‘q’ and ‘Q’
type codes.

(Contributed by Oren Tirosh and Hirokazu Yamamoto in bpo-1172711(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1172711


File: python.info,  Node: base64<5>,  Next: binascii<3>,  Prev: array<5>,  Up: Improved Modules<10>

1.12.20.3 base64
................

ASCII-only Unicode strings are now accepted by the decoding functions of
the *note base64: f. modern interface.  For example,
‘base64.b64decode('YWJj')’ returns ‘b'abc'’.  (Contributed by Catalin
Iacob in bpo-13641(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13641


File: python.info,  Node: binascii<3>,  Next: bz2<2>,  Prev: base64<5>,  Up: Improved Modules<10>

1.12.20.4 binascii
..................

In addition to the binary objects they normally accept, the ‘a2b_’
functions now all also accept ASCII-only strings as input.  (Contributed
by Antoine Pitrou in bpo-13637(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13637


File: python.info,  Node: bz2<2>,  Next: codecs<2>,  Prev: binascii<3>,  Up: Improved Modules<10>

1.12.20.5 bz2
.............

The *note bz2: 14. module has been rewritten from scratch.  In the
process, several new features have been added:

   * New *note bz2.open(): 1295. function: open a bzip2-compressed file
     in binary or text mode.

   * *note bz2.BZ2File: a68. can now read from and write to arbitrary
     file-like objects, by means of its constructor’s 'fileobj'
     argument.

     (Contributed by Nadeem Vawda in bpo-5863(1).)

   * *note bz2.BZ2File: a68. and *note bz2.decompress(): 1296. can now
     decompress multi-stream inputs (such as those produced by the
     ‘pbzip2’ tool).  *note bz2.BZ2File: a68. can now also be used to
     create this type of file, using the ‘'a'’ (append) mode.

     (Contributed by Nir Aides in bpo-1625(2).)

   * *note bz2.BZ2File: a68. now implements all of the *note
     io.BufferedIOBase: 8a4. API, except for the ‘detach()’ and
     ‘truncate()’ methods.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5863

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1625


File: python.info,  Node: codecs<2>,  Next: collections<7>,  Prev: bz2<2>,  Up: Improved Modules<10>

1.12.20.6 codecs
................

The *note mbcs: 57. codec has been rewritten to handle correctly
‘replace’ and ‘ignore’ error handlers on all Windows versions.  The
*note mbcs: 57. codec now supports all error handlers, instead of only
‘replace’ to encode and ‘ignore’ to decode.

A new Windows-only codec has been added: ‘cp65001’ (bpo-13216(1)).  It
is the Windows code page 65001 (Windows UTF-8, ‘CP_UTF8’).  For example,
it is used by ‘sys.stdout’ if the console output code page is set to
cp65001 (e.g., using ‘chcp 65001’ command).

Multibyte CJK decoders now resynchronize faster.  They only ignore the
first byte of an invalid byte sequence.  For example,
‘b'\xff\n'.decode('gb2312', 'replace')’ now returns a ‘\n’ after the
replacement character.

(bpo-12016(2))

Incremental CJK codec encoders are no longer reset at each call to their
encode() methods.  For example:

     >>> import codecs
     >>> encoder = codecs.getincrementalencoder('hz')('strict')
     >>> b''.join(encoder.encode(x) for x in '\u52ff\u65bd\u65bc\u4eba\u3002 Bye.')
     b'~{NpJ)l6HK!#~} Bye.'

This example gives ‘b'~{Np~}~{J)~}~{l6~}~{HK~}~{!#~} Bye.'’ with older
Python versions.

(bpo-12100(3))

The ‘unicode_internal’ codec has been deprecated.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13216

   (2) https://bugs.python.org/issue?@action=redirect&bpo=12016

   (3) https://bugs.python.org/issue?@action=redirect&bpo=12100


File: python.info,  Node: collections<7>,  Next: contextlib<7>,  Prev: codecs<2>,  Up: Improved Modules<10>

1.12.20.7 collections
.....................

Addition of a new *note ChainMap: e18. class to allow treating a number
of mappings as a single unit.  (Written by Raymond Hettinger for
bpo-11089(1), made public in bpo-11297(2).)

The abstract base classes have been moved in a new *note
collections.abc: 1f. module, to better differentiate between the
abstract and the concrete collections classes.  Aliases for ABCs are
still present in the *note collections: 1e. module to preserve existing
imports.  (bpo-11085(3))

The *note Counter: 1299. class now supports the unary ‘+’ and ‘-’
operators, as well as the in-place operators ‘+=’, ‘-=’, ‘|=’, and ‘&=’.
(Contributed by Raymond Hettinger in bpo-13121(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11089

   (2) https://bugs.python.org/issue?@action=redirect&bpo=11297

   (3) https://bugs.python.org/issue?@action=redirect&bpo=11085

   (4) https://bugs.python.org/issue?@action=redirect&bpo=13121


File: python.info,  Node: contextlib<7>,  Next: crypt<2>,  Prev: collections<7>,  Up: Improved Modules<10>

1.12.20.8 contextlib
....................

*note ExitStack: d20. now provides a solid foundation for programmatic
manipulation of context managers and similar cleanup functionality.
Unlike the previous ‘contextlib.nested’ API (which was deprecated and
removed), the new API is designed to work correctly regardless of
whether context managers acquire their resources in their ‘__init__’
method (for example, file objects) or in their ‘__enter__’ method (for
example, synchronisation objects from the *note threading: f3. module).

(bpo-13585(1))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13585


File: python.info,  Node: crypt<2>,  Next: curses<6>,  Prev: contextlib<7>,  Up: Improved Modules<10>

1.12.20.9 crypt
...............

Addition of salt and modular crypt format (hashing method) and the
‘mksalt()’ function to the ‘crypt’ module.

(bpo-10924(1))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10924


File: python.info,  Node: curses<6>,  Next: datetime<7>,  Prev: crypt<2>,  Up: Improved Modules<10>

1.12.20.10 curses
.................

   * If the *note curses: 2f. module is linked to the ncursesw library,
     use Unicode functions when Unicode strings or characters are passed
     (e.g.  ‘waddwstr()’), and bytes functions otherwise (e.g.
     ‘waddstr()’).

   * Use the locale encoding instead of ‘utf-8’ to encode Unicode
     strings.

   * *note curses.window: 129d. has a new *note curses.window.encoding:
     129e. attribute.

   * The *note curses.window: 129d. class has a new *note get_wch():
     129f. method to get a wide character

   * The *note curses: 2f. module has a new *note unget_wch(): 12a0.
     function to push a wide character so the next *note get_wch():
     129f. will return it

(Contributed by Iñigo Serna in bpo-6755(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6755


File: python.info,  Node: datetime<7>,  Next: decimal<4>,  Prev: curses<6>,  Up: Improved Modules<10>

1.12.20.11 datetime
...................

   * Equality comparisons between naive and aware *note datetime: 4e3.
     instances now return *note False: d2d. instead of raising *note
     TypeError: 198. (bpo-15006(1)).

   * New *note datetime.datetime.timestamp(): 12a2. method: Return POSIX
     timestamp corresponding to the *note datetime: 4e3. instance.

   * The *note datetime.datetime.strftime(): e90. method supports
     formatting years older than 1000.

   * The *note datetime.datetime.astimezone(): bc6. method can now be
     called without arguments to convert datetime instance to the system
     timezone.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15006


File: python.info,  Node: decimal<4>,  Next: email<6>,  Prev: datetime<7>,  Up: Improved Modules<10>

1.12.20.12 decimal
..................

bpo-7652(1) - integrate fast native decimal arithmetic.

     C-module and libmpdec written by Stefan Krah.

The new C version of the decimal module integrates the high speed
libmpdec library for arbitrary precision correctly rounded decimal
floating-point arithmetic.  libmpdec conforms to IBM’s General Decimal
Arithmetic Specification.

Performance gains range from 10x for database applications to 100x for
numerically intensive applications.  These numbers are expected gains
for standard precisions used in decimal floating-point arithmetic.
Since the precision is user configurable, the exact figures may vary.
For example, in integer bignum arithmetic the differences can be
significantly higher.

The following table is meant as an illustration.  Benchmarks are
available at ‘https://www.bytereef.org/mpdecimal/quickstart.html’.

                   decimal.py        _decimal           speedup
                                                        
     ---------------------------------------------------------------------
                                                        
     pi            42.02s            0.345s             120x
                                                        
                                                        
     telco         172.19s           5.68s              30x
                                                        
                                                        
     psycopg       3.57s             0.29s              12x
                                                        

* Menu:

* Features: Features<2>.
* API changes: API changes<2>.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=7652


File: python.info,  Node: Features<2>,  Next: API changes<2>,  Up: decimal<4>

1.12.20.13 Features
...................

   * The *note FloatOperation: 12a5. signal optionally enables stricter
     semantics for mixing floats and Decimals.

   * If Python is compiled without threads, the C version automatically
     disables the expensive thread local context machinery.  In this
     case, the variable *note HAVE_THREADS: 12a6. is set to ‘False’.


File: python.info,  Node: API changes<2>,  Prev: Features<2>,  Up: decimal<4>

1.12.20.14 API changes
......................

   * The C module has the following context limits, depending on the
     machine architecture:

                                           32-bit               64-bit
                                                                
          ------------------------------------------------------------------------------------
                                                                
          *note MAX_PREC: 12a8.            ‘425000000’          ‘999999999999999999’
                                                                
                                                                
          *note MAX_EMAX: 12a9.            ‘425000000’          ‘999999999999999999’
                                                                
                                                                
          *note MIN_EMIN: 12aa.            ‘-425000000’         ‘-999999999999999999’
                                                                

   * In the context templates (*note DefaultContext: 12ab, *note
     BasicContext: 12ac. and *note ExtendedContext: 12ad.) the magnitude
     of *note Emax: 12ae. and *note Emin: 12af. has changed to ‘999999’.

   * The *note Decimal: 1fe. constructor in decimal.py does not observe
     the context limits and converts values with arbitrary exponents or
     precision exactly.  Since the C version has internal limits, the
     following scheme is used: If possible, values are converted
     exactly, otherwise *note InvalidOperation: 12b0. is raised and the
     result is NaN. In the latter case it is always possible to use
     *note create_decimal(): 12b1. in order to obtain a rounded or
     inexact value.

   * The power function in decimal.py is always correctly rounded.  In
     the C version, it is defined in terms of the correctly rounded
     *note exp(): 12b2. and *note ln(): 12b3. functions, but the final
     result is only «almost always correctly rounded».

   * In the C version, the context dictionary containing the signals is
     a *note MutableMapping: 12b4.  For speed reasons, *note flags:
     12b5. and *note traps: 12b6. always refer to the same *note
     MutableMapping: 12b4. that the context was initialized with.  If a
     new signal dictionary is assigned, *note flags: 12b5. and *note
     traps: 12b6. are updated with the new values, but they do not
     reference the RHS dictionary.

   * Pickling a *note Context: 12b7. produces a different output in
     order to have a common interchange format for the Python and C
     versions.

   * The order of arguments in the *note Context: 12b7. constructor has
     been changed to match the order displayed by *note repr(): 1c1.

   * The ‘watchexp’ parameter in the *note quantize(): 12b8. method is
     deprecated.


File: python.info,  Node: email<6>,  Next: ftplib<3>,  Prev: decimal<4>,  Up: Improved Modules<10>

1.12.20.15 email
................

* Menu:

* Policy Framework::
* Provisional Policy with New Header API::
* Other API Changes::


File: python.info,  Node: Policy Framework,  Next: Provisional Policy with New Header API,  Up: email<6>

1.12.20.16 Policy Framework
...........................

The email package now has a *note policy: 53. framework.  A *note
Policy: 12bb. is an object with several methods and properties that
control how the email package behaves.  The primary policy for Python
3.3 is the *note Compat32: 12bc. policy, which provides backward
compatibility with the email package in Python 3.2.  A ‘policy’ can be
specified when an email message is parsed by a *note parser: 52, or when
a *note Message: 581. object is created, or when an email is serialized
using a *note generator: 44.  Unless overridden, a policy passed to a
‘parser’ is inherited by all the ‘Message’ object and sub-objects
created by the ‘parser’.  By default a ‘generator’ will use the policy
of the ‘Message’ object it is serializing.  The default policy is *note
compat32: e99.

The minimum set of controls implemented by all ‘policy’ objects are:

max_line_length     The maximum length, excluding the linesep character(s),
                    individual lines may have when a ‘Message’ is serialized.
                    Defaults to 78.
                    
                    
linesep             The character used to separate individual lines when a
                    ‘Message’ is serialized.  Defaults to ‘\n’.
                    
                    
cte_type            ‘7bit’ or ‘8bit’.  ‘8bit’ applies only to a ‘Bytes’
                    ‘generator’, and means that non-ASCII may be used where
                    allowed by the protocol (or where it exists in the
                    original input).
                    
                    
raise_on_defect     Causes a ‘parser’ to raise error when defects are
                    encountered instead of adding them to the ‘Message’
                    object’s ‘defects’ list.
                    

A new policy instance, with new settings, is created using the *note
clone(): 12bd. method of policy objects.  ‘clone’ takes any of the above
controls as keyword arguments.  Any control not specified in the call
retains its default value.  Thus you can create a policy that uses
‘\r\n’ linesep characters like this:

     mypolicy = compat32.clone(linesep='\r\n')

Policies can be used to make the generation of messages in the format
needed by your application simpler.  Instead of having to remember to
specify ‘linesep='\r\n'’ in all the places you call a ‘generator’, you
can specify it once, when you set the policy used by the ‘parser’ or the
‘Message’, whichever your program uses to create ‘Message’ objects.  On
the other hand, if you need to generate messages in multiple forms, you
can still specify the parameters in the appropriate ‘generator’ call.
Or you can have custom policy instances for your different cases, and
pass those in when you create the ‘generator’.


File: python.info,  Node: Provisional Policy with New Header API,  Next: Other API Changes,  Prev: Policy Framework,  Up: email<6>

1.12.20.17 Provisional Policy with New Header API
.................................................

While the policy framework is worthwhile all by itself, the main
motivation for introducing it is to allow the creation of new policies
that implement new features for the email package in a way that
maintains backward compatibility for those who do not use the new
policies.  Because the new policies introduce a new API, we are
releasing them in Python 3.3 as a *note provisional policy: 1244.
Backwards incompatible changes (up to and including removal of the code)
may occur if deemed necessary by the core developers.

The new policies are instances of *note EmailPolicy: 12bf, and add the
following additional controls:

refold_source       Controls whether or not headers parsed by a
                    *note parser: 52. are refolded by the
                    *note generator: 44.  It can be ‘none’, ‘long’, or ‘all’.
                    The default is ‘long’, which means that source headers
                    with a line longer than ‘max_line_length’ get refolded.
                    ‘none’ means no line get refolded, and ‘all’ means that
                    all lines get refolded.
                    
                    
header_factory      A callable that take a ‘name’ and ‘value’ and produces a
                    custom header object.
                    

The ‘header_factory’ is the key to the new features provided by the new
policies.  When one of the new policies is used, any header retrieved
from a ‘Message’ object is an object produced by the ‘header_factory’,
and any time you set a header on a ‘Message’ it becomes an object
produced by ‘header_factory’.  All such header objects have a ‘name’
attribute equal to the header name.  Address and Date headers have
additional attributes that give you access to the parsed data of the
header.  This means you can now do things like this:

     >>> m = Message(policy=SMTP)
     >>> m['To'] = 'Éric <foo@example.com>'
     >>> m['to']
     'Éric <foo@example.com>'
     >>> m['to'].addresses
     (Address(display_name='Éric', username='foo', domain='example.com'),)
     >>> m['to'].addresses[0].username
     'foo'
     >>> m['to'].addresses[0].display_name
     'Éric'
     >>> m['Date'] = email.utils.localtime()
     >>> m['Date'].datetime
     datetime.datetime(2012, 5, 25, 21, 39, 24, 465484, tzinfo=datetime.timezone(datetime.timedelta(-1, 72000), 'EDT'))
     >>> m['Date']
     'Fri, 25 May 2012 21:44:27 -0400'
     >>> print(m)
     To: =?utf-8?q?=C3=89ric?= <foo@example.com>
     Date: Fri, 25 May 2012 21:44:27 -0400

You will note that the unicode display name is automatically encoded as
‘utf-8’ when the message is serialized, but that when the header is
accessed directly, you get the unicode version.  This eliminates any
need to deal with the *note email.header: 45. *note decode_header():
12c0. or *note make_header(): 12c1. functions.

You can also create addresses from parts:

     >>> m['cc'] = [Group('pals', [Address('Bob', 'bob', 'example.com'),
     ...                           Address('Sally', 'sally', 'example.com')]),
     ...            Address('Bonzo', addr_spec='bonz@laugh.com')]
     >>> print(m)
     To: =?utf-8?q?=C3=89ric?= <foo@example.com>
     Date: Fri, 25 May 2012 21:44:27 -0400
     cc: pals: Bob <bob@example.com>, Sally <sally@example.com>;, Bonzo <bonz@laugh.com>

Decoding to unicode is done automatically:

     >>> m2 = message_from_string(str(m))
     >>> m2['to']
     'Éric <foo@example.com>'

When you parse a message, you can use the ‘addresses’ and ‘groups’
attributes of the header objects to access the groups and individual
addresses:

     >>> m2['cc'].addresses
     (Address(display_name='Bob', username='bob', domain='example.com'), Address(display_name='Sally', username='sally', domain='example.com'), Address(display_name='Bonzo', username='bonz', domain='laugh.com'))
     >>> m2['cc'].groups
     (Group(display_name='pals', addresses=(Address(display_name='Bob', username='bob', domain='example.com'), Address(display_name='Sally', username='sally', domain='example.com')), Group(display_name=None, addresses=(Address(display_name='Bonzo', username='bonz', domain='laugh.com'),))

In summary, if you use one of the new policies, header manipulation
works the way it ought to: your application works with unicode strings,
and the email package transparently encodes and decodes the unicode to
and from the RFC standard Content Transfer Encodings.


File: python.info,  Node: Other API Changes,  Prev: Provisional Policy with New Header API,  Up: email<6>

1.12.20.18 Other API Changes
............................

New *note BytesHeaderParser: 12c3, added to the *note parser: 52. module
to complement *note HeaderParser: 12c4. and complete the Bytes API.

New utility functions:

   * *note format_datetime(): 12c5.: given a *note datetime: 4e3,
     produce a string formatted for use in an email header.

   * *note parsedate_to_datetime(): 12c6.: given a date string from an
     email header, convert it into an aware *note datetime: 4e3, or a
     naive *note datetime: 4e3. if the offset is ‘-0000’.

   * *note localtime(): 2f7.: With no argument, returns the current
     local time as an aware *note datetime: 4e3. using the local *note
     timezone: 12c7.  Given an aware *note datetime: 4e3, converts it
     into an aware *note datetime: 4e3. using the local *note timezone:
     12c7.


File: python.info,  Node: ftplib<3>,  Next: functools<7>,  Prev: email<6>,  Up: Improved Modules<10>

1.12.20.19 ftplib
.................

   * *note ftplib.FTP: af8. now accepts a ‘source_address’ keyword
     argument to specify the ‘(host, port)’ to use as the source address
     in the bind call when creating the outgoing socket.  (Contributed
     by Giampaolo Rodolà in bpo-8594(1).)

   * The *note FTP_TLS: af9. class now provides a new *note ccc(): 12c9.
     function to revert control channel back to plaintext.  This can be
     useful to take advantage of firewalls that know how to handle NAT
     with non-secure FTP without opening fixed ports.  (Contributed by
     Giampaolo Rodolà in bpo-12139(2).)

   * Added *note ftplib.FTP.mlsd(): 12ca. method which provides a
     parsable directory listing format and deprecates *note
     ftplib.FTP.nlst(): 12cb. and *note ftplib.FTP.dir(): 12cc.
     (Contributed by Giampaolo Rodolà in bpo-11072(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8594

   (2) https://bugs.python.org/issue?@action=redirect&bpo=12139

   (3) https://bugs.python.org/issue?@action=redirect&bpo=11072


File: python.info,  Node: functools<7>,  Next: gc<7>,  Prev: ftplib<3>,  Up: Improved Modules<10>

1.12.20.20 functools
....................

The *note functools.lru_cache(): be4. decorator now accepts a ‘typed’
keyword argument (that defaults to ‘False’ to ensure that it caches
values of different types that compare equal in separate cache slots.
(Contributed by Raymond Hettinger in bpo-13227(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13227


File: python.info,  Node: gc<7>,  Next: hmac<5>,  Prev: functools<7>,  Up: Improved Modules<10>

1.12.20.21 gc
.............

It is now possible to register callbacks invoked by the garbage
collector before and after collection using the new *note callbacks:
12cf. list.


File: python.info,  Node: hmac<5>,  Next: http<5>,  Prev: gc<7>,  Up: Improved Modules<10>

1.12.20.22 hmac
...............

A new *note compare_digest(): 12d1. function has been added to prevent
side channel attacks on digests through timing analysis.  (Contributed
by Nick Coghlan and Christian Heimes in bpo-15061(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15061


File: python.info,  Node: http<5>,  Next: html<2>,  Prev: hmac<5>,  Up: Improved Modules<10>

1.12.20.23 http
...............

*note http.server.BaseHTTPRequestHandler: 12d3. now buffers the headers
and writes them all at once when *note end_headers(): 12d4. is called.
A new method *note flush_headers(): 12d5. can be used to directly manage
when the accumulated headers are sent.  (Contributed by Andrew Schaaf in
bpo-3709(1).)

*note http.server: 76. now produces valid ‘HTML 4.01 strict’ output.
(Contributed by Ezio Melotti in bpo-13295(2).)

*note http.client.HTTPResponse: 12d6. now has a *note readinto(): 12d7.
method, which means it can be used as an *note io.RawIOBase: 12d8.
class.  (Contributed by John Kuhn in bpo-13464(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=3709

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13295

   (3) https://bugs.python.org/issue?@action=redirect&bpo=13464


File: python.info,  Node: html<2>,  Next: imaplib<4>,  Prev: http<5>,  Up: Improved Modules<10>

1.12.20.24 html
...............

*note html.parser.HTMLParser: a79. is now able to parse broken markup
without raising errors, therefore the 'strict' argument of the
constructor and the ‘HTMLParseError’ exception are now deprecated.  The
ability to parse broken markup is the result of a number of bug fixes
that are also available on the latest bug fix releases of Python
2.7/3.2.  (Contributed by Ezio Melotti in bpo-15114(1), and
bpo-14538(2), bpo-13993(3), bpo-13960(4), bpo-13358(5), bpo-1745761(6),
bpo-755670(7), bpo-13357(8), bpo-12629(9), bpo-1200313(10),
bpo-670664(11), bpo-13273(12), bpo-12888(13), bpo-7311(14).)

A new *note html5: 12da. dictionary that maps HTML5 named character
references to the equivalent Unicode character(s) (e.g.  ‘html5['gt;']
== '>'’) has been added to the *note html.entities: 70. module.  The
dictionary is now also used by *note HTMLParser: a79.  (Contributed by
Ezio Melotti in bpo-11113(15) and bpo-15156(16).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15114

   (2) https://bugs.python.org/issue?@action=redirect&bpo=14538

   (3) https://bugs.python.org/issue?@action=redirect&bpo=13993

   (4) https://bugs.python.org/issue?@action=redirect&bpo=13960

   (5) https://bugs.python.org/issue?@action=redirect&bpo=13358

   (6) https://bugs.python.org/issue?@action=redirect&bpo=1745761

   (7) https://bugs.python.org/issue?@action=redirect&bpo=755670

   (8) https://bugs.python.org/issue?@action=redirect&bpo=13357

   (9) https://bugs.python.org/issue?@action=redirect&bpo=12629

   (10) https://bugs.python.org/issue?@action=redirect&bpo=1200313

   (11) https://bugs.python.org/issue?@action=redirect&bpo=670664

   (12) https://bugs.python.org/issue?@action=redirect&bpo=13273

   (13) https://bugs.python.org/issue?@action=redirect&bpo=12888

   (14) https://bugs.python.org/issue?@action=redirect&bpo=7311

   (15) https://bugs.python.org/issue?@action=redirect&bpo=11113

   (16) https://bugs.python.org/issue?@action=redirect&bpo=15156


File: python.info,  Node: imaplib<4>,  Next: inspect<10>,  Prev: html<2>,  Up: Improved Modules<10>

1.12.20.25 imaplib
..................

The *note IMAP4_SSL: b02. constructor now accepts an SSLContext
parameter to control parameters of the secure channel.

(Contributed by Sijin Joseph in bpo-8808(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8808


File: python.info,  Node: inspect<10>,  Next: io<8>,  Prev: imaplib<4>,  Up: Improved Modules<10>

1.12.20.26 inspect
..................

A new *note getclosurevars(): 12dd. function has been added.  This
function reports the current binding of all names referenced from the
function body and where those names were resolved, making it easier to
verify correct internal state when testing code that relies on stateful
closures.

(Contributed by Meador Inge and Nick Coghlan in bpo-13062(1).)

A new *note getgeneratorlocals(): 12de. function has been added.  This
function reports the current binding of local variables in the
generator’s stack frame, making it easier to verify correct internal
state when testing generators.

(Contributed by Meador Inge in bpo-15153(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13062

   (2) https://bugs.python.org/issue?@action=redirect&bpo=15153


File: python.info,  Node: io<8>,  Next: itertools<7>,  Prev: inspect<10>,  Up: Improved Modules<10>

1.12.20.27 io
.............

The *note open(): 741. function has a new ‘'x'’ mode that can be used to
exclusively create a new file, and raise a *note FileExistsError: 1222.
if the file already exists.  It is based on the C11 “x” mode to fopen().

(Contributed by David Townshend in bpo-12760(1).)

The constructor of the *note TextIOWrapper: 9c0. class has a new
'write_through' optional argument.  If 'write_through' is ‘True’, calls
to ‘write()’ are guaranteed not to be buffered: any data written on the
*note TextIOWrapper: 9c0. object is immediately handled to its
underlying binary buffer.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12760


File: python.info,  Node: itertools<7>,  Next: logging<7>,  Prev: io<8>,  Up: Improved Modules<10>

1.12.20.28 itertools
....................

*note accumulate(): bf2. now takes an optional ‘func’ argument for
providing a user-supplied binary function.


File: python.info,  Node: logging<7>,  Next: math<9>,  Prev: itertools<7>,  Up: Improved Modules<10>

1.12.20.29 logging
..................

The *note basicConfig(): bf5. function now supports an optional
‘handlers’ argument taking an iterable of handlers to be added to the
root logger.

A class level attribute ‘append_nul’ has been added to *note
SysLogHandler: 86d. to allow control of the appending of the ‘NUL’
(‘\000’) byte to syslog records, since for some daemons it is required
while for others it is passed through to the log.


File: python.info,  Node: math<9>,  Next: mmap<4>,  Prev: logging<7>,  Up: Improved Modules<10>

1.12.20.30 math
...............

The *note math: 92. module has a new function, *note log2(): 12e3, which
returns the base-2 logarithm of 'x'.

(Written by Mark Dickinson in bpo-11888(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11888


File: python.info,  Node: mmap<4>,  Next: multiprocessing<9>,  Prev: math<9>,  Up: Improved Modules<10>

1.12.20.31 mmap
...............

The *note read(): 12e5. method is now more compatible with other
file-like objects: if the argument is omitted or specified as ‘None’, it
returns the bytes from the current file position to the end of the
mapping.  (Contributed by Petri Lehtinen in bpo-12021(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12021


File: python.info,  Node: multiprocessing<9>,  Next: nntplib<2>,  Prev: mmap<4>,  Up: Improved Modules<10>

1.12.20.32 multiprocessing
..........................

The new *note multiprocessing.connection.wait(): 12e7. function allows
polling multiple objects (such as connections, sockets and pipes) with a
timeout.  (Contributed by Richard Oudkerk in bpo-12328(1).)

*note multiprocessing.connection.Connection: 12e8. objects can now be
transferred over multiprocessing connections.  (Contributed by Richard
Oudkerk in bpo-4892(2).)

*note multiprocessing.Process: 252. now accepts a ‘daemon’ keyword
argument to override the default behavior of inheriting the ‘daemon’
flag from the parent process (bpo-6064(3)).

New attribute *note multiprocessing.Process.sentinel: 12e9. allows a
program to wait on multiple *note Process: 252. objects at one time
using the appropriate OS primitives (for example, *note select: c6. on
posix systems).

New methods *note multiprocessing.pool.Pool.starmap(): 12ea. and *note
starmap_async(): 12eb. provide *note itertools.starmap(): 12ec.
equivalents to the existing *note multiprocessing.pool.Pool.map(): 12ed.
and *note map_async(): 12ee. functions.  (Contributed by Hynek Schlawack
in bpo-12708(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12328

   (2) https://bugs.python.org/issue?@action=redirect&bpo=4892

   (3) https://bugs.python.org/issue?@action=redirect&bpo=6064

   (4) https://bugs.python.org/issue?@action=redirect&bpo=12708


File: python.info,  Node: nntplib<2>,  Next: os<13>,  Prev: multiprocessing<9>,  Up: Improved Modules<10>

1.12.20.33 nntplib
..................

The ‘nntplib.NNTP’ class now supports the context management protocol to
unconditionally consume *note socket.error: 1258. exceptions and to
close the NNTP connection when done:

     >>> from nntplib import NNTP
     >>> with NNTP('news.gmane.org') as n:
     ...     n.group('gmane.comp.python.committers')
     ...
     ('211 1755 1 1755 gmane.comp.python.committers', 1755, 1, 1755, 'gmane.comp.python.committers')
     >>>

(Contributed by Giampaolo Rodolà in bpo-9795(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9795


File: python.info,  Node: os<13>,  Next: pdb<9>,  Prev: nntplib<2>,  Up: Improved Modules<10>

1.12.20.34 os
.............

   * The *note os: a5. module has a new *note pipe2(): 12f1. function
     that makes it possible to create a pipe with *note O_CLOEXEC: 127e.
     or *note O_NONBLOCK: 103d. flags set atomically.  This is
     especially useful to avoid race conditions in multi-threaded
     programs.

   * The *note os: a5. module has a new *note sendfile(): d07. function
     which provides an efficient «zero-copy» way for copying data from
     one file (or socket) descriptor to another.  The phrase «zero-copy»
     refers to the fact that all of the copying of data between the two
     descriptors is done entirely by the kernel, with no copying of data
     into userspace buffers.  *note sendfile(): d07. can be used to
     efficiently copy data from a file on disk to a network socket, e.g.
     for downloading a file.

     (Patch submitted by Ross Lagerwall and Giampaolo Rodolà in
     bpo-10882(1).)

   * To avoid race conditions like symlink attacks and issues with
     temporary files and directories, it is more reliable (and also
     faster) to manipulate file descriptors instead of file names.
     Python 3.3 enhances existing functions and introduces new functions
     to work on file descriptors (bpo-4761(2), bpo-10755(3) and
     bpo-14626(4)).

        - The *note os: a5. module has a new *note fwalk(): d54.
          function similar to *note walk(): 6d1. except that it also
          yields file descriptors referring to the directories visited.
          This is especially useful to avoid symlink races.

        - The following functions get new optional 'dir_fd' (*note paths
          relative to directory descriptors: 12f2.) and/or
          'follow_symlinks' (*note not following symlinks: 12f3.): *note
          access(): 12f4, *note chflags(): 12f5, *note chmod(): 52a,
          *note chown(): 12f6, *note link(): 12f7, *note lstat(): 6c9,
          *note mkdir(): 52c, *note mkfifo(): f92, *note mknod(): f93,
          *note open(): f94, *note readlink(): b1c, *note remove():
          12f8, *note rename(): 12f9, *note replace(): 12fa, *note
          rmdir(): 12fb, *note stat(): 26d, *note symlink(): 12fc, *note
          unlink(): 12fd, *note utime(): 12fe.  Platform support for
          using these parameters can be checked via the sets *note
          os.supports_dir_fd: 12ff. and *note
          os.supports_follow_symlinks: 1300.

        - The following functions now support a file descriptor for
          their path argument: *note chdir(): 822, *note chmod(): 52a,
          *note chown(): 12f6, *note execve(): 1301, *note listdir():
          1302, *note pathconf(): 1303, *note exists(): c05, *note
          stat(): 26d, *note statvfs(): 1304, *note utime(): 12fe.
          Platform support for this can be checked via the *note
          os.supports_fd: 1305. set.

   * *note access(): 12f4. accepts an ‘effective_ids’ keyword argument
     to turn on using the effective uid/gid rather than the real uid/gid
     in the access check.  Platform support for this can be checked via
     the *note supports_effective_ids: 1306. set.

   * The *note os: a5. module has two new functions: *note
     getpriority(): 1307. and *note setpriority(): 1308.  They can be
     used to get or set process niceness/priority in a fashion similar
     to *note os.nice(): 1309. but extended to all processes instead of
     just the current one.

     (Patch submitted by Giampaolo Rodolà in bpo-10784(5).)

   * The new *note os.replace(): 12fa. function allows cross-platform
     renaming of a file with overwriting the destination.  With *note
     os.rename(): 12f9, an existing destination file is overwritten
     under POSIX, but raises an error under Windows.  (Contributed by
     Antoine Pitrou in bpo-8828(6).)

   * The stat family of functions (*note stat(): 26d, *note fstat():
     f8e, and *note lstat(): 6c9.) now support reading a file’s
     timestamps with nanosecond precision.  Symmetrically, *note
     utime(): 12fe. can now write file timestamps with nanosecond
     precision.  (Contributed by Larry Hastings in bpo-14127(7).)

   * The new *note os.get_terminal_size(): 130a. function queries the
     size of the terminal attached to a file descriptor.  See also *note
     shutil.get_terminal_size(): 130b.  (Contributed by Zbigniew
     Jędrzejewski-Szmek in bpo-13609(8).)

   * New functions to support Linux extended attributes (bpo-12720(9)):
     *note getxattr(): 130c, *note listxattr(): 130d, *note
     removexattr(): 130e, *note setxattr(): 130f.

   * New interface to the scheduler.  These functions control how a
     process is allocated CPU time by the operating system.  New
     functions: *note sched_get_priority_max(): 1310, *note
     sched_get_priority_min(): 1311, *note sched_getaffinity(): 1312,
     *note sched_getparam(): 1313, *note sched_getscheduler(): 1314,
     *note sched_rr_get_interval(): 1315, *note sched_setaffinity():
     1316, *note sched_setparam(): 1317, *note sched_setscheduler():
     1318, *note sched_yield(): 1319,

   * New functions to control the file system:

        * *note posix_fadvise(): f95.: Announces an intention to access
          data in a specific pattern thus allowing the kernel to make
          optimizations.

        * *note posix_fallocate(): f96.: Ensures that enough disk space
          is allocated for a file.

        * *note sync(): 131a.: Force write of everything to disk.

   * Additional new posix functions:

        * *note lockf(): 131b.: Apply, test or remove a POSIX lock on an
          open file descriptor.

        * *note pread(): d58.: Read from a file descriptor at an offset,
          the file offset remains unchanged.

        * *note pwrite(): d5b.: Write to a file descriptor from an
          offset, leaving the file offset unchanged.

        * *note readv(): d57.: Read from a file descriptor into a number
          of writable buffers.

        * *note truncate(): 103e.: Truncate the file corresponding to
          'path', so that it is at most 'length' bytes in size.

        * *note waitid(): f9b.: Wait for the completion of one or more
          child processes.

        * *note writev(): d5a.: Write the contents of 'buffers' to a
          file descriptor, where 'buffers' is an arbitrary sequence of
          buffers.

        * *note getgrouplist(): 131c. (bpo-9344(10)): Return list of
          group ids that specified user belongs to.

   * *note times(): 131d. and *note uname(): 131e.: Return type changed
     from a tuple to a tuple-like object with named attributes.

   * Some platforms now support additional constants for the *note
     lseek(): 131f. function, such as ‘os.SEEK_HOLE’ and ‘os.SEEK_DATA’.

   * New constants *note RTLD_LAZY: 1320, *note RTLD_NOW: 1321, *note
     RTLD_GLOBAL: 1322, *note RTLD_LOCAL: 1323, *note RTLD_NODELETE:
     1324, *note RTLD_NOLOAD: 1325, and *note RTLD_DEEPBIND: 1326. are
     available on platforms that support them.  These are for use with
     the *note sys.setdlopenflags(): 1327. function, and supersede the
     similar constants defined in *note ctypes: 2e. and ‘DLFCN’.
     (Contributed by Victor Stinner in bpo-13226(11).)

   * *note os.symlink(): 12fc. now accepts (and ignores) the
     ‘target_is_directory’ keyword argument on non-Windows platforms, to
     ease cross-platform support.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10882

   (2) https://bugs.python.org/issue?@action=redirect&bpo=4761

   (3) https://bugs.python.org/issue?@action=redirect&bpo=10755

   (4) https://bugs.python.org/issue?@action=redirect&bpo=14626

   (5) https://bugs.python.org/issue?@action=redirect&bpo=10784

   (6) https://bugs.python.org/issue?@action=redirect&bpo=8828

   (7) https://bugs.python.org/issue?@action=redirect&bpo=14127

   (8) https://bugs.python.org/issue?@action=redirect&bpo=13609

   (9) https://bugs.python.org/issue?@action=redirect&bpo=12720

   (10) https://bugs.python.org/issue?@action=redirect&bpo=9344

   (11) https://bugs.python.org/issue?@action=redirect&bpo=13226


File: python.info,  Node: pdb<9>,  Next: pickle<6>,  Prev: os<13>,  Up: Improved Modules<10>

1.12.20.35 pdb
..............

Tab-completion is now available not only for command names, but also
their arguments.  For example, for the ‘break’ command, function and
file names are completed.

(Contributed by Georg Brandl in bpo-14210(1))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14210


File: python.info,  Node: pickle<6>,  Next: pydoc<6>,  Prev: pdb<9>,  Up: Improved Modules<10>

1.12.20.36 pickle
.................

*note pickle.Pickler: c15. objects now have an optional *note
dispatch_table: 132a. attribute allowing per-pickler reduction functions
to be set.

(Contributed by Richard Oudkerk in bpo-14166(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14166


File: python.info,  Node: pydoc<6>,  Next: re<10>,  Prev: pickle<6>,  Up: Improved Modules<10>

1.12.20.37 pydoc
................

The Tk GUI and the ‘serve()’ function have been removed from the *note
pydoc: ba. module: ‘pydoc -g’ and ‘serve()’ have been deprecated in
Python 3.2.


File: python.info,  Node: re<10>,  Next: sched,  Prev: pydoc<6>,  Up: Improved Modules<10>

1.12.20.38 re
.............

*note str: 169. regular expressions now support ‘\u’ and ‘\U’ escapes.

(Contributed by Serhiy Storchaka in bpo-3665(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=3665


File: python.info,  Node: sched,  Next: select<2>,  Prev: re<10>,  Up: Improved Modules<10>

1.12.20.39 sched
................

   * *note run(): 132e. now accepts a 'blocking' parameter which when
     set to false makes the method execute the scheduled events due to
     expire soonest (if any) and then return immediately.  This is
     useful in case you want to use the *note scheduler: 132f. in
     non-blocking applications.  (Contributed by Giampaolo Rodolà in
     bpo-13449(1).)

   * *note scheduler: 132f. class can now be safely used in
     multi-threaded environments.  (Contributed by Josiah Carlson and
     Giampaolo Rodolà in bpo-8684(2).)

   * 'timefunc' and 'delayfunct' parameters of *note scheduler: 132f.
     class constructor are now optional and defaults to *note
     time.time(): 55d. and *note time.sleep(): 8ad. respectively.
     (Contributed by Chris Clark in bpo-13245(3).)

   * *note enter(): 1330. and *note enterabs(): 1331. 'argument'
     parameter is now optional.  (Contributed by Chris Clark in
     bpo-13245(4).)

   * *note enter(): 1330. and *note enterabs(): 1331. now accept a
     'kwargs' parameter.  (Contributed by Chris Clark in bpo-13245(5).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13449

   (2) https://bugs.python.org/issue?@action=redirect&bpo=8684

   (3) https://bugs.python.org/issue?@action=redirect&bpo=13245

   (4) https://bugs.python.org/issue?@action=redirect&bpo=13245

   (5) https://bugs.python.org/issue?@action=redirect&bpo=13245


File: python.info,  Node: select<2>,  Next: shlex<3>,  Prev: sched,  Up: Improved Modules<10>

1.12.20.40 select
.................

Solaris and derivative platforms have a new class *note select.devpoll:
1198. for high performance asynchronous sockets via ‘/dev/poll’.
(Contributed by Jesús Cea Avión in bpo-6397(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6397


File: python.info,  Node: shlex<3>,  Next: shutil<7>,  Prev: select<2>,  Up: Improved Modules<10>

1.12.20.41 shlex
................

The previously undocumented helper function ‘quote’ from the ‘pipes’
modules has been moved to the *note shlex: c9. module and documented.
*note quote(): 582. properly escapes all characters in a string that
might be otherwise given special meaning by the shell.


File: python.info,  Node: shutil<7>,  Next: signal<4>,  Prev: shlex<3>,  Up: Improved Modules<10>

1.12.20.42 shutil
.................

   * New functions:

        * *note disk_usage(): 1335.: provides total, used and free disk
          space statistics.  (Contributed by Giampaolo Rodolà in
          bpo-12442(1).)

        * *note chown(): 549.: allows one to change user and/or group of
          the given path also specifying the user/group names and not
          only their numeric ids.  (Contributed by Sandro Tosi in
          bpo-12191(2).)

        * *note shutil.get_terminal_size(): 130b.: returns the size of
          the terminal window to which the interpreter is attached.
          (Contributed by Zbigniew Jędrzejewski-Szmek in bpo-13609(3).)

   * *note copy2(): c52. and *note copystat(): 1336. now preserve file
     timestamps with nanosecond precision on platforms that support it.
     They also preserve file «extended attributes» on Linux.
     (Contributed by Larry Hastings in bpo-14127(4) and bpo-15238(5).)

   * Several functions now take an optional ‘symlinks’ argument: when
     that parameter is true, symlinks aren’t dereferenced and the
     operation instead acts on the symlink itself (or creates one, if
     relevant).  (Contributed by Hynek Schlawack in bpo-12715(6).)

   * When copying files to a different file system, *note move(): c53.
     now handles symlinks the way the posix ‘mv’ command does,
     recreating the symlink rather than copying the target file
     contents.  (Contributed by Jonathan Niehof in bpo-9993(7).)  *note
     move(): c53. now also returns the ‘dst’ argument as its result.

   * *note rmtree(): 356. is now resistant to symlink attacks on
     platforms which support the new ‘dir_fd’ parameter in *note
     os.open(): f94. and *note os.unlink(): 12fd.  (Contributed by
     Martin von Löwis and Hynek Schlawack in bpo-4489(8).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12442

   (2) https://bugs.python.org/issue?@action=redirect&bpo=12191

   (3) https://bugs.python.org/issue?@action=redirect&bpo=13609

   (4) https://bugs.python.org/issue?@action=redirect&bpo=14127

   (5) https://bugs.python.org/issue?@action=redirect&bpo=15238

   (6) https://bugs.python.org/issue?@action=redirect&bpo=12715

   (7) https://bugs.python.org/issue?@action=redirect&bpo=9993

   (8) https://bugs.python.org/issue?@action=redirect&bpo=4489


File: python.info,  Node: signal<4>,  Next: smtpd<4>,  Prev: shutil<7>,  Up: Improved Modules<10>

1.12.20.43 signal
.................

   * The *note signal: cb. module has new functions:

        * *note pthread_sigmask(): 1338.: fetch and/or change the signal
          mask of the calling thread (Contributed by Jean-Paul Calderone
          in bpo-8407(1));

        * *note pthread_kill(): 1339.: send a signal to a thread;

        * *note sigpending(): 133a.: examine pending functions;

        * *note sigwait(): 133b.: wait a signal;

        * *note sigwaitinfo(): fad.: wait for a signal, returning
          detailed information about it;

        * *note sigtimedwait(): fac.: like *note sigwaitinfo(): fad. but
          with a timeout.

   * The signal handler writes the signal number as a single byte
     instead of a nul byte into the wakeup file descriptor.  So it is
     possible to wait more than one signal and know which signals were
     raised.

   * *note signal.signal(): 133c. and *note signal.siginterrupt(): 133d.
     raise an OSError, instead of a RuntimeError: OSError has an errno
     attribute.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8407


File: python.info,  Node: smtpd<4>,  Next: smtplib<4>,  Prev: signal<4>,  Up: Improved Modules<10>

1.12.20.44 smtpd
................

The ‘smtpd’ module now supports RFC 5321(1) (extended SMTP) and RFC
1870(2) (size extension).  Per the standard, these extensions are
enabled if and only if the client initiates the session with an ‘EHLO’
command.

(Initial ‘ELHO’ support by Alberto Trevino.  Size extension by Juhana
Jauhiainen.  Substantial additional work on the patch contributed by
Michele Orrù and Dan Boswell.  bpo-8739(3))

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc5321.html

   (2) https://datatracker.ietf.org/doc/html/rfc1870.html

   (3) https://bugs.python.org/issue?@action=redirect&bpo=8739


File: python.info,  Node: smtplib<4>,  Next: socket<11>,  Prev: smtpd<4>,  Up: Improved Modules<10>

1.12.20.45 smtplib
..................

The *note SMTP: b29, *note SMTP_SSL: b2a, and *note LMTP: b2b. classes
now accept a ‘source_address’ keyword argument to specify the ‘(host,
port)’ to use as the source address in the bind call when creating the
outgoing socket.  (Contributed by Paulo Scardine in bpo-11281(1).)

*note SMTP: b29. now supports the context management protocol, allowing
an ‘SMTP’ instance to be used in a ‘with’ statement.  (Contributed by
Giampaolo Rodolà in bpo-11289(2).)

The *note SMTP_SSL: b2a. constructor and the *note starttls(): 1340.
method now accept an SSLContext parameter to control parameters of the
secure channel.  (Contributed by Kasun Herath in bpo-8809(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11281

   (2) https://bugs.python.org/issue?@action=redirect&bpo=11289

   (3) https://bugs.python.org/issue?@action=redirect&bpo=8809


File: python.info,  Node: socket<11>,  Next: socketserver<3>,  Prev: smtplib<4>,  Up: Improved Modules<10>

1.12.20.46 socket
.................

   * The *note socket: fa3. class now exposes additional methods to
     process ancillary data when supported by the underlying platform:

        * *note sendmsg(): 6a2.

        * *note recvmsg(): fa8.

        * *note recvmsg_into(): 1342.

     (Contributed by David Watson in bpo-6560(1), based on an earlier
     patch by Heiko Wundram)

   * The *note socket: fa3. class now supports the PF_CAN protocol
     family (‘https://en.wikipedia.org/wiki/Socketcan’), on Linux
     (‘https://lwn.net/Articles/253425’).

     (Contributed by Matthias Fuchs, updated by Tiago Gonçalves in
     bpo-10141(2).)

   * The *note socket: fa3. class now supports the PF_RDS protocol
     family (‘https://en.wikipedia.org/wiki/Reliable_Datagram_Sockets’
     and https://oss.oracle.com/projects/rds(3)).

   * The *note socket: fa3. class now supports the ‘PF_SYSTEM’ protocol
     family on OS X. (Contributed by Michael Goderbauer in
     bpo-13777(4).)

   * New function *note sethostname(): 1343. allows the hostname to be
     set on Unix systems if the calling process has sufficient
     privileges.  (Contributed by Ross Lagerwall in bpo-10866(5).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6560

   (2) https://bugs.python.org/issue?@action=redirect&bpo=10141

   (3) 
https://web.archive.org/web/20130115155505/https://oss.oracle.com/projects/rds/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=13777

   (5) https://bugs.python.org/issue?@action=redirect&bpo=10866


File: python.info,  Node: socketserver<3>,  Next: sqlite3<11>,  Prev: socket<11>,  Up: Improved Modules<10>

1.12.20.47 socketserver
.......................

*note BaseServer: 1345. now has an overridable method *note
service_actions(): 1346. that is called by the *note serve_forever():
1347. method in the service loop.  *note ForkingMixIn: d73. now uses
this to clean up zombie child processes.  (Contributed by Justin
Warkentin in bpo-11109(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11109


File: python.info,  Node: sqlite3<11>,  Next: ssl<12>,  Prev: socketserver<3>,  Up: Improved Modules<10>

1.12.20.48 sqlite3
..................

New *note sqlite3.Connection: 54e. method *note set_trace_callback():
5ab. can be used to capture a trace of all sql commands processed by
sqlite.  (Contributed by Torsten Landschoff in bpo-11688(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11688


File: python.info,  Node: ssl<12>,  Next: stat<2>,  Prev: sqlite3<11>,  Up: Improved Modules<10>

1.12.20.49 ssl
..............

   * The *note ssl: d5. module has two new random generation functions:

        * *note RAND_bytes(): 748.: generate cryptographically strong
          pseudo-random bytes.

        * ‘RAND_pseudo_bytes()’: generate pseudo-random bytes.

     (Contributed by Victor Stinner in bpo-12049(1).)

   * The *note ssl: d5. module now exposes a finer-grained exception
     hierarchy in order to make it easier to inspect the various kinds
     of errors.  (Contributed by Antoine Pitrou in bpo-11183(2).)

   * *note load_cert_chain(): 598. now accepts a 'password' argument to
     be used if the private key is encrypted.  (Contributed by Adam
     Simpkins in bpo-12803(3).)

   * Diffie-Hellman key exchange, both regular and Elliptic Curve-based,
     is now supported through the *note load_dh_params(): 134a. and
     *note set_ecdh_curve(): 134b. methods.  (Contributed by Antoine
     Pitrou in bpo-13626(4) and bpo-13627(5).)

   * SSL sockets have a new *note get_channel_binding(): 134c. method
     allowing the implementation of certain authentication mechanisms
     such as SCRAM-SHA-1-PLUS. (Contributed by Jacek Konieczny in
     bpo-12551(6).)

   * You can query the SSL compression algorithm used by an SSL socket,
     thanks to its new *note compression(): 134d. method.  The new
     attribute *note OP_NO_COMPRESSION: 134e. can be used to disable
     compression.  (Contributed by Antoine Pitrou in bpo-13634(7).)

   * Support has been added for the Next Protocol Negotiation extension
     using the *note ssl.SSLContext.set_npn_protocols(): 358. method.
     (Contributed by Colin Marc in bpo-14204(8).)

   * SSL errors can now be introspected more easily thanks to *note
     library: 134f. and *note reason: 1350. attributes.  (Contributed by
     Antoine Pitrou in bpo-14837(9).)

   * The *note get_server_certificate(): a3f. function now supports
     IPv6.  (Contributed by Charles-François Natali in bpo-11811(10).)

   * New attribute *note OP_CIPHER_SERVER_PREFERENCE: 1351. allows
     setting SSLv3 server sockets to use the server’s cipher ordering
     preference rather than the client’s (bpo-13635(11)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12049

   (2) https://bugs.python.org/issue?@action=redirect&bpo=11183

   (3) https://bugs.python.org/issue?@action=redirect&bpo=12803

   (4) https://bugs.python.org/issue?@action=redirect&bpo=13626

   (5) https://bugs.python.org/issue?@action=redirect&bpo=13627

   (6) https://bugs.python.org/issue?@action=redirect&bpo=12551

   (7) https://bugs.python.org/issue?@action=redirect&bpo=13634

   (8) https://bugs.python.org/issue?@action=redirect&bpo=14204

   (9) https://bugs.python.org/issue?@action=redirect&bpo=14837

   (10) https://bugs.python.org/issue?@action=redirect&bpo=11811

   (11) https://bugs.python.org/issue?@action=redirect&bpo=13635


File: python.info,  Node: stat<2>,  Next: struct<4>,  Prev: ssl<12>,  Up: Improved Modules<10>

1.12.20.50 stat
...............

The undocumented tarfile.filemode function has been moved to *note
stat.filemode(): 1353.  It can be used to convert a file’s mode to a
string of the form “-rwxrwxrwx”.

(Contributed by Giampaolo Rodolà in bpo-14807(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14807


File: python.info,  Node: struct<4>,  Next: subprocess<6>,  Prev: stat<2>,  Up: Improved Modules<10>

1.12.20.51 struct
.................

The *note struct: db. module now supports ‘ssize_t’ and ‘size_t’ via the
new codes ‘n’ and ‘N’, respectively.  (Contributed by Antoine Pitrou in
bpo-3163(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=3163


File: python.info,  Node: subprocess<6>,  Next: sys<13>,  Prev: struct<4>,  Up: Improved Modules<10>

1.12.20.52 subprocess
.....................

Command strings can now be bytes objects on posix platforms.
(Contributed by Victor Stinner in bpo-8513(1).)

A new constant *note DEVNULL: 1356. allows suppressing output in a
platform-independent fashion.  (Contributed by Ross Lagerwall in
bpo-5870(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8513

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5870


File: python.info,  Node: sys<13>,  Next: tarfile<9>,  Prev: subprocess<6>,  Up: Improved Modules<10>

1.12.20.53 sys
..............

The *note sys: df. module has a new *note thread_info: 1358. *note named
tuple: 85f. holding information about the thread implementation
(bpo-11223(1)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=11223


File: python.info,  Node: tarfile<9>,  Next: tempfile<4>,  Prev: sys<13>,  Up: Improved Modules<10>

1.12.20.54 tarfile
..................

*note tarfile: e4. now supports ‘lzma’ encoding via the *note lzma: 8e.
module.  (Contributed by Lars Gustäbel in bpo-5689(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5689


File: python.info,  Node: tempfile<4>,  Next: textwrap<3>,  Prev: tarfile<9>,  Up: Improved Modules<10>

1.12.20.55 tempfile
...................

*note tempfile.SpooledTemporaryFile: 8a3.'s ‘truncate()’ method now
accepts a ‘size’ parameter.  (Contributed by Ryan Kelly in bpo-9957(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9957


File: python.info,  Node: textwrap<3>,  Next: threading<9>,  Prev: tempfile<4>,  Up: Improved Modules<10>

1.12.20.56 textwrap
...................

The *note textwrap: f2. module has a new *note indent(): 57d. that makes
it straightforward to add a common prefix to selected lines in a block
of text (bpo-13857(1)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13857


File: python.info,  Node: threading<9>,  Next: time<8>,  Prev: textwrap<3>,  Up: Improved Modules<10>

1.12.20.57 threading
....................

*note threading.Condition: 135d, *note threading.Semaphore: 135e, *note
threading.BoundedSemaphore: 135f, *note threading.Event: 1360, and *note
threading.Timer: 1361, all of which used to be factory functions
returning a class instance, are now classes and may be subclassed.
(Contributed by Éric Araujo in bpo-10968(1).)

The *note threading.Thread: 176. constructor now accepts a ‘daemon’
keyword argument to override the default behavior of inheriting the
‘daemon’ flag value from the parent thread (bpo-6064(2)).

The formerly private function ‘_thread.get_ident’ is now available as
the public function *note threading.get_ident(): 1362.  This eliminates
several cases of direct access to the ‘_thread’ module in the stdlib.
Third party code that used ‘_thread.get_ident’ should likewise be
changed to use the new public interface.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10968

   (2) https://bugs.python.org/issue?@action=redirect&bpo=6064


File: python.info,  Node: time<8>,  Next: types<8>,  Prev: threading<9>,  Up: Improved Modules<10>

1.12.20.58 time
...............

The PEP 418(1) added new functions to the *note time: f4. module:

   * *note get_clock_info(): 1364.: Get information on a clock.

   * *note monotonic(): 55c.: Monotonic clock (cannot go backward), not
     affected by system clock updates.

   * *note perf_counter(): c7c.: Performance counter with the highest
     available resolution to measure a short duration.

   * *note process_time(): c7d.: Sum of the system and user CPU time of
     the current process.

Other new functions:

   * *note clock_getres(): 1365, *note clock_gettime(): 1366. and *note
     clock_settime(): 1367. functions with ‘CLOCK_XXX’ constants.
     (Contributed by Victor Stinner in bpo-10278(2).)

To improve cross platform consistency, *note sleep(): 8ad. now raises a
*note ValueError: 2ec. when passed a negative sleep value.  Previously
this was an error on posix, but produced an infinite sleep on Windows.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0418/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=10278


File: python.info,  Node: types<8>,  Next: unittest<11>,  Prev: time<8>,  Up: Improved Modules<10>

1.12.20.59 types
................

Add a new *note types.MappingProxyType: 699. class: Read-only proxy of a
mapping.  (bpo-14386(1))

The new functions *note types.new_class(): 1369. and *note
types.prepare_class(): 136a. provide support for PEP 3115(2) compliant
dynamic type creation.  (bpo-14588(3))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14386

   (2) https://peps.python.org/pep-3115/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=14588


File: python.info,  Node: unittest<11>,  Next: urllib<6>,  Prev: types<8>,  Up: Improved Modules<10>

1.12.20.60 unittest
...................

*note assertRaises(): 751, *note assertRaisesRegex(): 753, *note
assertWarns(): 136c, and *note assertWarnsRegex(): 136d. now accept a
keyword argument 'msg' when used as context managers.  (Contributed by
Ezio Melotti and Winston Ewert in bpo-10775(1).)

*note unittest.TestCase.run(): 136e. now returns the *note TestResult:
136f. object.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10775


File: python.info,  Node: urllib<6>,  Next: webbrowser<4>,  Prev: unittest<11>,  Up: Improved Modules<10>

1.12.20.61 urllib
.................

The *note Request: 11da. class, now accepts a 'method' argument used by
*note get_method(): 1371. to determine what HTTP method should be used.
For example, this will send a ‘'HEAD'’ request:

     >>> urlopen(Request('https://www.python.org', method='HEAD'))

(bpo-1673007(1))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1673007


File: python.info,  Node: webbrowser<4>,  Next: xml etree ElementTree<2>,  Prev: urllib<6>,  Up: Improved Modules<10>

1.12.20.62 webbrowser
.....................

The *note webbrowser: 11b. module supports more «browsers»: Google
Chrome (named ‘chrome’, ‘chromium’, ‘chrome-browser’ or
‘chromium-browser’ depending on the version and operating system), and
the generic launchers ‘xdg-open’, from the FreeDesktop.org project, and
‘gvfs-open’, which is the default URI handler for GNOME 3.  (The former
contributed by Arnaud Calmettes in bpo-13620(1), the latter by Matthias
Klose in bpo-14493(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13620

   (2) https://bugs.python.org/issue?@action=redirect&bpo=14493


File: python.info,  Node: xml etree ElementTree<2>,  Next: zlib<3>,  Prev: webbrowser<4>,  Up: Improved Modules<10>

1.12.20.63 xml.etree.ElementTree
................................

The *note xml.etree.ElementTree: 12b. module now imports its C
accelerator by default; there is no longer a need to explicitly import
‘xml.etree.cElementTree’ (this module stays for backwards compatibility,
but is now deprecated).  In addition, the ‘iter’ family of methods of
*note Element: 363. has been optimized (rewritten in C). The module’s
documentation has also been greatly improved with added examples and a
more detailed reference.


File: python.info,  Node: zlib<3>,  Prev: xml etree ElementTree<2>,  Up: Improved Modules<10>

1.12.20.64 zlib
...............

New attribute *note zlib.Decompress.eof: 1375. makes it possible to
distinguish between a properly formed compressed stream and an
incomplete or truncated one.  (Contributed by Nadeem Vawda in
bpo-12646(1).)

New attribute *note zlib.ZLIB_RUNTIME_VERSION: 1376. reports the version
string of the underlying ‘zlib’ library that is loaded at runtime.
(Contributed by Torsten Landschoff in bpo-12306(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12646

   (2) https://bugs.python.org/issue?@action=redirect&bpo=12306


File: python.info,  Node: Optimizations<10>,  Next: Build and C API Changes<4>,  Prev: Improved Modules<10>,  Up: What’s New In Python 3 3

1.12.21 Optimizations
---------------------

Major performance enhancements have been added:

   * Thanks to PEP 393(1), some operations on Unicode strings have been
     optimized:

        * the memory footprint is divided by 2 to 4 depending on the
          text

        * encode an ASCII string to UTF-8 doesn’t need to encode
          characters anymore, the UTF-8 representation is shared with
          the ASCII representation

        * the UTF-8 encoder has been optimized

        * repeating a single ASCII letter and getting a substring of an
          ASCII string is 4 times faster

   * UTF-8 is now 2x to 4x faster.  UTF-16 encoding is now up to 10x
     faster.

     (Contributed by Serhiy Storchaka, bpo-14624(2), bpo-14738(3) and
     bpo-15026(4).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0393/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=14624

   (3) https://bugs.python.org/issue?@action=redirect&bpo=14738

   (4) https://bugs.python.org/issue?@action=redirect&bpo=15026


File: python.info,  Node: Build and C API Changes<4>,  Next: Deprecated<11>,  Prev: Optimizations<10>,  Up: What’s New In Python 3 3

1.12.22 Build and C API Changes
-------------------------------

Changes to Python’s build process and to the C API include:

   * New PEP 3118(1) related function:

        * *note PyMemoryView_FromMemory(): 1378.

   * PEP 393(2) added new Unicode types, macros and functions:

        * High-level API:

             * *note PyUnicode_CopyCharacters(): ab4.

             * *note PyUnicode_FindChar(): ab8.

             * *note PyUnicode_GetLength(): ab2, *note
               PyUnicode_GET_LENGTH: ab3.

             * *note PyUnicode_New(): aab.

             * *note PyUnicode_Substring(): ab5.

             * *note PyUnicode_ReadChar(): 1379, *note
               PyUnicode_WriteChar(): 137a.

        * Low-level API:

             * *note Py_UCS1: 137b, *note Py_UCS2: 137c, *note Py_UCS4:
               33d. types

             * *note PyASCIIObject: 137d. and *note
               PyCompactUnicodeObject: 137e. structures

             * *note PyUnicode_READY: 434.

             * *note PyUnicode_FromKindAndData(): 137f.

             * *note PyUnicode_AsUCS4(): 1380, *note
               PyUnicode_AsUCS4Copy(): aba.

             * *note PyUnicode_DATA: 1381, *note PyUnicode_1BYTE_DATA:
               1382, *note PyUnicode_2BYTE_DATA: 1383, *note
               PyUnicode_4BYTE_DATA: 1384.

             * *note PyUnicode_KIND: 1385. with ‘PyUnicode_Kind’ enum:
               ‘PyUnicode_WCHAR_KIND’, *note PyUnicode_1BYTE_KIND: 1386,
               *note PyUnicode_2BYTE_KIND: 1387, *note
               PyUnicode_4BYTE_KIND: 1388.

             * *note PyUnicode_READ: 1389, *note PyUnicode_READ_CHAR:
               138a, *note PyUnicode_WRITE: 138b.

             * *note PyUnicode_MAX_CHAR_VALUE: 138c.

   * *note PyArg_ParseTuple: 3c1. now accepts a *note bytearray: 344.
     for the ‘c’ format (bpo-12380(3)).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3118/

   (2) https://peps.python.org/pep-0393/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=12380


File: python.info,  Node: Deprecated<11>,  Next: Porting to Python 3 3,  Prev: Build and C API Changes<4>,  Up: What’s New In Python 3 3

1.12.23 Deprecated
------------------

* Menu:

* Unsupported Operating Systems: Unsupported Operating Systems<2>.
* Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<4>.
* Deprecated functions and types of the C API: Deprecated functions and types of the C API<3>.
* Deprecated features::


File: python.info,  Node: Unsupported Operating Systems<2>,  Next: Deprecated Python modules functions and methods<4>,  Up: Deprecated<11>

1.12.23.1 Unsupported Operating Systems
.......................................

OS/2 and VMS are no longer supported due to the lack of a maintainer.

Windows 2000 and Windows platforms which set ‘COMSPEC’ to ‘command.com’
are no longer supported due to maintenance burden.

OSF support, which was deprecated in 3.2, has been completely removed.


File: python.info,  Node: Deprecated Python modules functions and methods<4>,  Next: Deprecated functions and types of the C API<3>,  Prev: Unsupported Operating Systems<2>,  Up: Deprecated<11>

1.12.23.2 Deprecated Python modules, functions and methods
..........................................................

   * Passing a non-empty string to ‘object.__format__()’ is deprecated,
     and will produce a *note TypeError: 198. in Python 3.4
     (bpo-9856(1)).

   * The ‘unicode_internal’ codec has been deprecated because of the PEP
     393(2), use UTF-8, UTF-16 (‘utf-16-le’ or ‘utf-16-be’), or UTF-32
     (‘utf-32-le’ or ‘utf-32-be’)

   * *note ftplib.FTP.nlst(): 12cb. and *note ftplib.FTP.dir(): 12cc.:
     use *note ftplib.FTP.mlsd(): 12ca.

   * ‘platform.popen()’: use the *note subprocess: dc. module.  Check
     especially the *note Replacing Older Functions with the subprocess
     Module: 1390. section (bpo-11377(3)).

   * bpo-13374(4): The Windows bytes API has been deprecated in the
     *note os: a5. module.  Use Unicode filenames, instead of bytes
     filenames, to not depend on the ANSI code page anymore and to
     support any filename.

   * bpo-13988(5): The ‘xml.etree.cElementTree’ module is deprecated.
     The accelerator is used automatically whenever available.

   * The behaviour of ‘time.clock()’ depends on the platform: use the
     new *note time.perf_counter(): c7c. or *note time.process_time():
     c7d. function instead, depending on your requirements, to have a
     well defined behaviour.

   * The ‘os.stat_float_times()’ function is deprecated.

   * *note abc: 4. module:

        * *note abc.abstractproperty: 128c. has been deprecated, use
          *note property: 4b4. with *note abc.abstractmethod(): 128d.
          instead.

        * *note abc.abstractclassmethod: 128e. has been deprecated, use
          *note classmethod: 48f. with *note abc.abstractmethod(): 128d.
          instead.

        * *note abc.abstractstaticmethod: 128f. has been deprecated, use
          *note staticmethod: 453. with *note abc.abstractmethod():
          128d. instead.

   * *note importlib: 7b. package:

        * *note importlib.abc.SourceLoader.path_mtime(): 1391. is now
          deprecated in favour of *note
          importlib.abc.SourceLoader.path_stats(): 1392. as bytecode
          files now store both the modification time and size of the
          source file the bytecode file was compiled from.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9856

   (2) https://peps.python.org/pep-0393/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=11377

   (4) https://bugs.python.org/issue?@action=redirect&bpo=13374

   (5) https://bugs.python.org/issue?@action=redirect&bpo=13988


File: python.info,  Node: Deprecated functions and types of the C API<3>,  Next: Deprecated features,  Prev: Deprecated Python modules functions and methods<4>,  Up: Deprecated<11>

1.12.23.3 Deprecated functions and types of the C API
.....................................................

The *note Py_UNICODE: 3e0. has been deprecated by PEP 393(1) and will be
removed in Python 4.  All functions using this type are deprecated:

Unicode functions and methods using *note Py_UNICODE: 3e0. and *note
Py_UNICODE: 3e0.* types:

   * ‘PyUnicode_FromUnicode’: use *note PyUnicode_FromWideChar(): 1394.
     or *note PyUnicode_FromKindAndData(): 137f.

   * ‘PyUnicode_AS_UNICODE’, ‘PyUnicode_AsUnicode()’,
     ‘PyUnicode_AsUnicodeAndSize()’: use *note
     PyUnicode_AsWideCharString(): abb.

   * ‘PyUnicode_AS_DATA’: use *note PyUnicode_DATA: 1381. with *note
     PyUnicode_READ: 1389. and *note PyUnicode_WRITE: 138b.

   * ‘PyUnicode_GET_SIZE’, ‘PyUnicode_GetSize()’: use *note
     PyUnicode_GET_LENGTH: ab3. or *note PyUnicode_GetLength(): ab2.

   * ‘PyUnicode_GET_DATA_SIZE’: use ‘PyUnicode_GET_LENGTH(str) *
     PyUnicode_KIND(str)’ (only work on ready strings)

   * ‘PyUnicode_AsUnicodeCopy()’: use *note PyUnicode_AsUCS4Copy(): aba.
     or *note PyUnicode_AsWideCharString(): abb.

   * ‘PyUnicode_GetMax()’

Functions and macros manipulating Py_UNICODE* strings:

   * ‘Py_UNICODE_strlen()’: use *note PyUnicode_GetLength(): ab2. or
     *note PyUnicode_GET_LENGTH: ab3.

   * ‘Py_UNICODE_strcat()’: use *note PyUnicode_CopyCharacters(): ab4.
     or *note PyUnicode_FromFormat(): 62b.

   * ‘Py_UNICODE_strcpy()’, ‘Py_UNICODE_strncpy()’, ‘Py_UNICODE_COPY()’:
     use *note PyUnicode_CopyCharacters(): ab4. or *note
     PyUnicode_Substring(): ab5.

   * ‘Py_UNICODE_strcmp()’: use *note PyUnicode_Compare(): ab6.

   * ‘Py_UNICODE_strncmp()’: use *note PyUnicode_Tailmatch(): ab7.

   * ‘Py_UNICODE_strchr()’, ‘Py_UNICODE_strrchr()’: use *note
     PyUnicode_FindChar(): ab8.

   * ‘Py_UNICODE_FILL()’: use *note PyUnicode_Fill(): 1395.

   * ‘Py_UNICODE_MATCH’

Encoders:

   * ‘PyUnicode_Encode()’: use ‘PyUnicode_AsEncodedObject()’

   * ‘PyUnicode_EncodeUTF7()’

   * ‘PyUnicode_EncodeUTF8()’: use *note PyUnicode_AsUTF8(): 424. or
     *note PyUnicode_AsUTF8String(): 1396.

   * ‘PyUnicode_EncodeUTF32()’

   * ‘PyUnicode_EncodeUTF16()’

   * ‘PyUnicode_EncodeUnicodeEscape()’ use *note
     PyUnicode_AsUnicodeEscapeString(): 1397.

   * ‘PyUnicode_EncodeRawUnicodeEscape()’ use *note
     PyUnicode_AsRawUnicodeEscapeString(): 1398.

   * ‘PyUnicode_EncodeLatin1()’: use *note PyUnicode_AsLatin1String():
     1399.

   * ‘PyUnicode_EncodeASCII()’: use *note PyUnicode_AsASCIIString():
     139a.

   * ‘PyUnicode_EncodeCharmap()’

   * ‘PyUnicode_TranslateCharmap()’

   * ‘PyUnicode_EncodeMBCS()’: use *note PyUnicode_AsMBCSString(): 139b.
     or *note PyUnicode_EncodeCodePage(): 139c. (with ‘CP_ACP’
     code_page)

   * ‘PyUnicode_EncodeDecimal()’, ‘PyUnicode_TransformDecimalToASCII()’

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0393/


File: python.info,  Node: Deprecated features,  Prev: Deprecated functions and types of the C API<3>,  Up: Deprecated<11>

1.12.23.4 Deprecated features
.............................

The *note array: 8. module’s ‘'u'’ format code is now deprecated and
will be removed in Python 4 together with the rest of the (*note
Py_UNICODE: 3e0.) API.


File: python.info,  Node: Porting to Python 3 3,  Prev: Deprecated<11>,  Up: What’s New In Python 3 3

1.12.24 Porting to Python 3.3
-----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code.

* Menu:

* Porting Python code::
* Porting C code::
* Building C extensions::
* Command Line Switch Changes::


File: python.info,  Node: Porting Python code,  Next: Porting C code,  Up: Porting to Python 3 3

1.12.24.1 Porting Python code
.............................

   * Hash randomization is enabled by default.  Set the *note
     PYTHONHASHSEED: 127f. environment variable to ‘0’ to disable hash
     randomization.  See also the *note object.__hash__(): cf5. method.

   * bpo-12326(1): On Linux, sys.platform doesn’t contain the major
     version anymore.  It is now always “linux”, instead of “linux2” or
     “linux3” depending on the Linux version used to build Python.
     Replace sys.platform == “linux2” with
     sys.platform.startswith(“linux”), or directly sys.platform ==
     “linux” if you don’t need to support older Python versions.

   * bpo-13847(2), bpo-14180(3): *note time: f4. and *note datetime:
     34.: *note OverflowError: a83. is now raised instead of *note
     ValueError: 2ec. if a timestamp is out of range.  *note OSError:
     2c0. is now raised if C functions ‘gmtime()’ or ‘localtime()’
     failed.

   * The default finders used by import now utilize a cache of what is
     contained within a specific directory.  If you create a Python
     source file or sourceless bytecode file, make sure to call *note
     importlib.invalidate_caches(): e0c. to clear out the cache for the
     finders to notice the new file.

   * *note ImportError: 65b. now uses the full name of the module that
     was attempted to be imported.  Doctests that check ImportErrors”
     message will need to be updated to use the full name of the module
     instead of just the tail of the name.

   * The 'index' argument to *note __import__(): ad3. now defaults to 0
     instead of -1 and no longer support negative values.  It was an
     oversight when PEP 328(4) was implemented that the default value
     remained -1.  If you need to continue to perform a relative import
     followed by an absolute import, then perform the relative import
     using an index of 1, followed by another import using an index of
     0.  It is preferred, though, that you use *note
     importlib.import_module(): 73d. rather than call *note
     __import__(): ad3. directly.

   * *note __import__(): ad3. no longer allows one to use an index value
     other than 0 for top-level modules.  E.g.  ‘__import__('sys',
     level=1)’ is now an error.

   * Because *note sys.meta_path: f29. and *note sys.path_hooks: 1226.
     now have finders on them by default, you will most likely want to
     use *note list.insert(): 13a0. instead of *note list.append(): 8dd.
     to add to those lists.

   * Because ‘None’ is now inserted into *note sys.path_importer_cache:
     7fb, if you are clearing out entries in the dictionary of paths
     that do not have a finder, you will need to remove keys paired with
     values of ‘None’ 'and' ‘imp.NullImporter’ to be
     backwards-compatible.  This will lead to extra overhead on older
     versions of Python that re-insert ‘None’ into *note
     sys.path_importer_cache: 7fb. where it represents the use of
     implicit finders, but semantically it should not change anything.

   * ‘importlib.abc.Finder’ no longer specifies a ‘find_module()’
     abstract method that must be implemented.  If you were relying on
     subclasses to implement that method, make sure to check for the
     method’s existence first.  You will probably want to check for
     ‘find_loader()’ first, though, in the case of working with *note
     path entry finders: 1273.

   * *note pkgutil: ae. has been converted to use *note importlib: 7b.
     internally.  This eliminates many edge cases where the old
     behaviour of the PEP 302(5) import emulation failed to match the
     behaviour of the real import system.  The import emulation itself
     is still present, but is now deprecated.  The *note
     pkgutil.iter_importers(): 13a1. and *note pkgutil.walk_packages():
     dfb. functions special case the standard import hooks so they are
     still supported even though they do not provide the non-standard
     ‘iter_modules()’ method.

   * A longstanding RFC-compliance bug (bpo-1079(6)) in the parsing done
     by *note email.header.decode_header(): 12c0. has been fixed.  Code
     that uses the standard idiom to convert encoded headers into
     unicode (‘str(make_header(decode_header(h))’) will see no change,
     but code that looks at the individual tuples returned by
     decode_header will see that whitespace that precedes or follows
     ‘ASCII’ sections is now included in the ‘ASCII’ section.  Code that
     builds headers using ‘make_header’ should also continue to work
     without change, since ‘make_header’ continues to add whitespace
     between ‘ASCII’ and non-‘ASCII’ sections if it is not already
     present in the input strings.

   * *note email.utils.formataddr(): 13a2. now does the correct content
     transfer encoding when passed non-‘ASCII’ display names.  Any code
     that depended on the previous buggy behavior that preserved the
     non-‘ASCII’ unicode in the formatted output string will need to be
     changed (bpo-1690608(7)).

   * *note poplib.POP3.quit(): 13a3. may now raise protocol errors like
     all other ‘poplib’ methods.  Code that assumes ‘quit’ does not
     raise *note poplib.error_proto: 13a4. errors may need to be changed
     if errors on ‘quit’ are encountered by a particular application
     (bpo-11291(8)).

   * The ‘strict’ argument to *note email.parser.Parser: 13a5,
     deprecated since Python 2.4, has finally been removed.

   * The deprecated method ‘unittest.TestCase.assertSameElements’ has
     been removed.

   * The deprecated variable ‘time.accept2dyear’ has been removed.

   * The deprecated ‘Context._clamp’ attribute has been removed from the
     *note decimal: 3a. module.  It was previously replaced by the
     public attribute *note clamp: 13a6.  (See bpo-8540(9).)

   * The undocumented internal helper class ‘SSLFakeFile’ has been
     removed from *note smtplib: cf, since its functionality has long
     been provided directly by *note socket.socket.makefile(): 13a7.

   * Passing a negative value to *note time.sleep(): 8ad. on Windows now
     raises an error instead of sleeping forever.  It has always raised
     an error on posix.

   * The ‘ast.__version__’ constant has been removed.  If you need to
     make decisions affected by the AST version, use *note
     sys.version_info: 8b0. to make the decision.

   * Code that used to work around the fact that the *note threading:
     f3. module used factory functions by subclassing the private
     classes will need to change to subclass the now-public classes.

   * The undocumented debugging machinery in the threading module has
     been removed, simplifying the code.  This should have no effect on
     production code, but is mentioned here in case any application
     debug frameworks were interacting with it (bpo-13550(10)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=12326

   (2) https://bugs.python.org/issue?@action=redirect&bpo=13847

   (3) https://bugs.python.org/issue?@action=redirect&bpo=14180

   (4) https://peps.python.org/pep-0328/

   (5) https://peps.python.org/pep-0302/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=1079

   (7) https://bugs.python.org/issue?@action=redirect&bpo=1690608

   (8) https://bugs.python.org/issue?@action=redirect&bpo=11291

   (9) https://bugs.python.org/issue?@action=redirect&bpo=8540

   (10) https://bugs.python.org/issue?@action=redirect&bpo=13550


File: python.info,  Node: Porting C code,  Next: Building C extensions,  Prev: Porting Python code,  Up: Porting to Python 3 3

1.12.24.2 Porting C code
........................

   * In the course of changes to the buffer API the undocumented
     ‘smalltable’ member of the *note Py_buffer: 95d. structure has been
     removed and the layout of the ‘PyMemoryViewObject’ has changed.

     All extensions relying on the relevant parts in ‘memoryobject.h’ or
     ‘object.h’ must be rebuilt.

   * Due to *note PEP 393: 1240, the *note Py_UNICODE: 3e0. type and all
     functions using this type are deprecated (but will stay available
     for at least five years).  If you were using low-level Unicode APIs
     to construct and access unicode objects and you want to benefit of
     the memory footprint reduction provided by PEP 393(1), you have to
     convert your code to the new *note Unicode API: 13a8.

     However, if you only have been using high-level functions such as
     *note PyUnicode_Concat(): 13a9, *note PyUnicode_Join(): 13aa. or
     *note PyUnicode_FromFormat(): 62b, your code will automatically
     take advantage of the new unicode representations.

   * *note PyImport_GetMagicNumber(): 13ab. now returns ‘-1’ upon
     failure.

   * As a negative value for the 'level' argument to *note __import__():
     ad3. is no longer valid, the same now holds for *note
     PyImport_ImportModuleLevel(): 13ac.  This also means that the value
     of 'level' used by *note PyImport_ImportModuleEx(): 13ad. is now
     ‘0’ instead of ‘-1’.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0393/


File: python.info,  Node: Building C extensions,  Next: Command Line Switch Changes,  Prev: Porting C code,  Up: Porting to Python 3 3

1.12.24.3 Building C extensions
...............................

   * The range of possible file names for C extensions has been
     narrowed.  Very rarely used spellings have been suppressed: under
     POSIX, files named ‘xxxmodule.so’, ‘xxxmodule.abi3.so’ and
     ‘xxxmodule.cpython-*.so’ are no longer recognized as implementing
     the ‘xxx’ module.  If you had been generating such files, you have
     to switch to the other spellings (i.e., remove the ‘module’ string
     from the file names).

     (implemented in bpo-14040(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14040


File: python.info,  Node: Command Line Switch Changes,  Prev: Building C extensions,  Up: Porting to Python 3 3

1.12.24.4 Command Line Switch Changes
.....................................

   * The -Q command-line flag and related artifacts have been removed.
     Code checking sys.flags.division_warning will need updating.

     (bpo-10998(1), contributed by Éric Araujo.)

   * When ‘python’ is started with *note -S: 13b0, ‘import site’ will no
     longer add site-specific paths to the module search paths.  In
     previous versions, it did.

     (bpo-11591(2), contributed by Carl Meyer with editions by Éric
     Araujo.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10998

   (2) https://bugs.python.org/issue?@action=redirect&bpo=11591


File: python.info,  Node: What’s New In Python 3 2,  Next: What’s New In Python 3 1,  Prev: What’s New In Python 3 3,  Up: Novità in Python

1.13 What’s New In Python 3.2
=============================


Author: Raymond Hettinger

This article explains the new features in Python 3.2 as compared to 3.1.
Python 3.2 was released on February 20, 2011.  It focuses on a few
highlights and gives a few examples.  For full details, see the
Misc/NEWS(1) file.

Vedi anche
..........

PEP 392(2) - Python 3.2 Release Schedule

* Menu:

* PEP 384; Defining a Stable ABI: PEP 384 Defining a Stable ABI.
* PEP 389; Argparse Command Line Parsing Module: PEP 389 Argparse Command Line Parsing Module.
* PEP 391; Dictionary Based Configuration for Logging: PEP 391 Dictionary Based Configuration for Logging.
* PEP 3148; The concurrent.futures module: PEP 3148 The concurrent futures module.
* PEP 3147; PYC Repository Directories: PEP 3147 PYC Repository Directories.
* PEP 3149; ABI Version Tagged .so Files: PEP 3149 ABI Version Tagged so Files.
* PEP 3333; Python Web Server Gateway Interface v1.0.1: PEP 3333 Python Web Server Gateway Interface v1 0 1.
* Other Language Changes: Other Language Changes<11>.
* New, Improved, and Deprecated Modules: New Improved and Deprecated Modules.
* Multi-threading::
* Optimizations: Optimizations<11>.
* Unicode::
* Codecs::
* Documentation::
* IDLE::
* Code Repository::
* Build and C API Changes: Build and C API Changes<5>.
* Porting to Python 3.2: Porting to Python 3 2.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/blob/076ca6c3c8df3030307e548d9be792ce3c1c6eea/Misc/NEWS

   (2) https://peps.python.org/pep-0392/


File: python.info,  Node: PEP 384 Defining a Stable ABI,  Next: PEP 389 Argparse Command Line Parsing Module,  Up: What’s New In Python 3 2

1.13.1 PEP 384: Defining a Stable ABI
-------------------------------------

In the past, extension modules built for one Python version were often
not usable with other Python versions.  Particularly on Windows, every
feature release of Python required rebuilding all extension modules that
one wanted to use.  This requirement was the result of the free access
to Python interpreter internals that extension modules could use.

With Python 3.2, an alternative approach becomes available: extension
modules which restrict themselves to a limited API (by defining
Py_LIMITED_API) cannot use many of the internals, but are constrained to
a set of API functions that are promised to be stable for several
releases.  As a consequence, extension modules built for 3.2 in that
mode will also work with 3.3, 3.4, and so on.  Extension modules that
make use of details of memory structures can still be built, but will
need to be recompiled for every feature release.

Vedi anche
..........

PEP 384(1) - Defining a Stable ABI

     PEP written by Martin von Löwis.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0384/


File: python.info,  Node: PEP 389 Argparse Command Line Parsing Module,  Next: PEP 391 Dictionary Based Configuration for Logging,  Prev: PEP 384 Defining a Stable ABI,  Up: What’s New In Python 3 2

1.13.2 PEP 389: Argparse Command Line Parsing Module
----------------------------------------------------

A new module for command line parsing, *note argparse: 7, was introduced
to overcome the limitations of *note optparse: a4. which did not provide
support for positional arguments (not just options), subcommands,
required options and other common patterns of specifying and validating
options.

This module has already had widespread success in the community as a
third-party module.  Being more fully featured than its predecessor, the
*note argparse: 7. module is now the preferred module for command-line
processing.  The older module is still being kept available because of
the substantial amount of legacy code that depends on it.

Here’s an annotated example parser showing features like limiting
results to a set of choices, specifying a 'metavar' in the help screen,
validating that one or more positional arguments is present, and making
a required option:

     import argparse
     parser = argparse.ArgumentParser(
                 description = 'Manage servers',         # main description for help
                 epilog = 'Tested on Solaris and Linux') # displayed after help
     parser.add_argument('action',                       # argument name
                 choices = ['deploy', 'start', 'stop'],  # three allowed values
                 help = 'action on each target')         # help msg
     parser.add_argument('targets',
                 metavar = 'HOSTNAME',                   # var name used in help msg
                 nargs = '+',                            # require one or more targets
                 help = 'url for target machines')       # help msg explanation
     parser.add_argument('-u', '--user',                 # -u or --user option
                 required = True,                        # make it a required argument
                 help = 'login as user')

Example of calling the parser on a command string:

     >>> cmd = 'deploy sneezy.example.com sleepy.example.com -u skycaptain'
     >>> result = parser.parse_args(cmd.split())
     >>> result.action
     'deploy'
     >>> result.targets
     ['sneezy.example.com', 'sleepy.example.com']
     >>> result.user
     'skycaptain'

Example of the parser’s automatically generated help:

     >>> parser.parse_args('-h'.split())

     usage: manage_cloud.py [-h] -u USER
                            {deploy,start,stop} HOSTNAME [HOSTNAME ...]

     Manage servers

     positional arguments:
       {deploy,start,stop}   action on each target
       HOSTNAME              url for target machines

     optional arguments:
       -h, --help            show this help message and exit
       -u USER, --user USER  login as user

     Tested on Solaris and Linux

An especially nice *note argparse: 7. feature is the ability to define
subparsers, each with their own argument patterns and help displays:

     import argparse
     parser = argparse.ArgumentParser(prog='HELM')
     subparsers = parser.add_subparsers()

     parser_l = subparsers.add_parser('launch', help='Launch Control')   # first subgroup
     parser_l.add_argument('-m', '--missiles', action='store_true')
     parser_l.add_argument('-t', '--torpedos', action='store_true')

     parser_m = subparsers.add_parser('move', help='Move Vessel',        # second subgroup
                                      aliases=('steer', 'turn'))         # equivalent names
     parser_m.add_argument('-c', '--course', type=int, required=True)
     parser_m.add_argument('-s', '--speed', type=int, default=0)

     $ ./helm.py --help                         # top level help (launch and move)
     $ ./helm.py launch --help                  # help for launch options
     $ ./helm.py launch --missiles              # set missiles=True and torpedos=False
     $ ./helm.py steer --course 180 --speed 5   # set movement parameters

Vedi anche
..........

PEP 389(1) - New Command Line Parsing Module

     PEP written by Steven Bethard.

*note Migrating optparse code to argparse: 13b6. for details on the
differences from *note optparse: a4.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0389/


File: python.info,  Node: PEP 391 Dictionary Based Configuration for Logging,  Next: PEP 3148 The concurrent futures module,  Prev: PEP 389 Argparse Command Line Parsing Module,  Up: What’s New In Python 3 2

1.13.3 PEP 391: Dictionary Based Configuration for Logging
----------------------------------------------------------

The *note logging: 8b. module provided two kinds of configuration, one
style with function calls for each option or another style driven by an
external file saved in a *note configparser: 26. format.  Those options
did not provide the flexibility to create configurations from JSON or
YAML files, nor did they support incremental configuration, which is
needed for specifying logger options from a command line.

To support a more flexible style, the module now offers *note
logging.config.dictConfig(): 13b8. for specifying logging configuration
with plain Python dictionaries.  The configuration options include
formatters, handlers, filters, and loggers.  Here’s a working example of
a configuration dictionary:

     {"version": 1,
      "formatters": {"brief": {"format": "%(levelname)-8s: %(name)-15s: %(message)s"},
                     "full": {"format": "%(asctime)s %(name)-15s %(levelname)-8s %(message)s"}
                     },
      "handlers": {"console": {
                        "class": "logging.StreamHandler",
                        "formatter": "brief",
                        "level": "INFO",
                        "stream": "ext://sys.stdout"},
                   "console_priority": {
                        "class": "logging.StreamHandler",
                        "formatter": "full",
                        "level": "ERROR",
                        "stream": "ext://sys.stderr"}
                   },
      "root": {"level": "DEBUG", "handlers": ["console", "console_priority"]}}

If that dictionary is stored in a file called ‘conf.json’, it can be
loaded and called with code like this:

     >>> import json, logging.config
     >>> with open('conf.json') as f:
     ...     conf = json.load(f)
     ...
     >>> logging.config.dictConfig(conf)
     >>> logging.info("Transaction completed normally")
     INFO    : root           : Transaction completed normally
     >>> logging.critical("Abnormal termination")
     2011-02-17 11:14:36,694 root            CRITICAL Abnormal termination

Vedi anche
..........

PEP 391(1) - Dictionary Based Configuration for Logging

     PEP written by Vinay Sajip.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0391/


File: python.info,  Node: PEP 3148 The concurrent futures module,  Next: PEP 3147 PYC Repository Directories,  Prev: PEP 391 Dictionary Based Configuration for Logging,  Up: What’s New In Python 3 2

1.13.4 PEP 3148: The ‘concurrent.futures’ module
------------------------------------------------

Code for creating and managing concurrency is being collected in a new
top-level namespace, 'concurrent'.  Its first member is a 'futures'
package which provides a uniform high-level interface for managing
threads and processes.

The design for *note concurrent.futures: 24. was inspired by the
'java.util.concurrent' package.  In that model, a running call and its
result are represented by a *note Future: 13ba. object that abstracts
features common to threads, processes, and remote procedure calls.  That
object supports status checks (running or done), timeouts,
cancellations, adding callbacks, and access to results or exceptions.

The primary offering of the new module is a pair of executor classes for
launching and managing calls.  The goal of the executors is to make it
easier to use existing tools for making parallel calls.  They save the
effort needed to setup a pool of resources, launch the calls, create a
results queue, add time-out handling, and limit the total number of
threads, processes, or remote procedure calls.

Ideally, each application should share a single executor across multiple
components so that process and thread limits can be centrally managed.
This solves the design challenge that arises when each component has its
own competing strategy for resource management.

Both classes share a common interface with three methods: *note
submit(): c77. for scheduling a callable and returning a *note Future:
13ba. object; *note map(): 1dc. for scheduling many asynchronous calls
at a time, and *note shutdown(): aec. for freeing resources.  The class
is a *note context manager: 1e1. and can be used in a *note with: 186.
statement to assure that resources are automatically released when
currently pending futures are done executing.

A simple of example of *note ThreadPoolExecutor: 94a. is a launch of
four parallel threads for copying files:

     import concurrent.futures, shutil
     with concurrent.futures.ThreadPoolExecutor(max_workers=4) as e:
         e.submit(shutil.copy, 'src1.txt', 'dest1.txt')
         e.submit(shutil.copy, 'src2.txt', 'dest2.txt')
         e.submit(shutil.copy, 'src3.txt', 'dest3.txt')
         e.submit(shutil.copy, 'src3.txt', 'dest4.txt')

Vedi anche
..........

PEP 3148(1) - Futures – Execute Computations Asynchronously

     PEP written by Brian Quinlan.

*note Code for Threaded Parallel URL reads: 13bb, an example using
threads to fetch multiple web pages in parallel.

*note Code for computing prime numbers in parallel: 13bc, an example
demonstrating *note ProcessPoolExecutor: 1d6.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3148/


File: python.info,  Node: PEP 3147 PYC Repository Directories,  Next: PEP 3149 ABI Version Tagged so Files,  Prev: PEP 3148 The concurrent futures module,  Up: What’s New In Python 3 2

1.13.5 PEP 3147: PYC Repository Directories
-------------------------------------------

Python’s scheme for caching bytecode in '.pyc' files did not work well
in environments with multiple Python interpreters.  If one interpreter
encountered a cached file created by another interpreter, it would
recompile the source and overwrite the cached file, thus losing the
benefits of caching.

The issue of «pyc fights» has become more pronounced as it has become
commonplace for Linux distributions to ship with multiple versions of
Python.  These conflicts also arise with CPython alternatives such as
Unladen Swallow.

To solve this problem, Python’s import machinery has been extended to
use distinct filenames for each interpreter.  Instead of Python 3.2 and
Python 3.3 and Unladen Swallow each competing for a file called
«mymodule.pyc», they will now look for «mymodule.cpython-32.pyc»,
«mymodule.cpython-33.pyc», and «mymodule.unladen10.pyc».  And to prevent
all of these new files from cluttering source directories, the 'pyc'
files are now collected in a «__pycache__» directory stored under the
package directory.

Aside from the filenames and target directories, the new scheme has a
few aspects that are visible to the programmer:

   * Imported modules now have a *note __cached__: 321. attribute which
     stores the name of the actual file that was imported:

          >>> import collections
          >>> collections.__cached__
          'c:/py32/lib/__pycache__/collections.cpython-32.pyc'

   * The tag that is unique to each interpreter is accessible from the
     ‘imp’ module:

          >>> import imp
          >>> imp.get_tag()
          'cpython-32'

   * Scripts that try to deduce source filename from the imported file
     now need to be smarter.  It is no longer sufficient to simply strip
     the «c» from a «.pyc» filename.  Instead, use the new functions in
     the ‘imp’ module:

          >>> imp.source_from_cache('c:/py32/lib/__pycache__/collections.cpython-32.pyc')
          'c:/py32/lib/collections.py'
          >>> imp.cache_from_source('c:/py32/lib/collections.py')
          'c:/py32/lib/__pycache__/collections.cpython-32.pyc'

   * The *note py_compile: b8. and *note compileall: 21. modules have
     been updated to reflect the new naming convention and target
     directory.  The command-line invocation of 'compileall' has new
     options: ‘-i’ for specifying a list of files and directories to
     compile and ‘-b’ which causes bytecode files to be written to their
     legacy location rather than '__pycache__'.

   * The *note importlib.abc: 7c. module has been updated with new *note
     abstract base classes: 13be. for loading bytecode files.  The
     obsolete ABCs, ‘PyLoader’ and ‘PyPycLoader’, have been deprecated
     (instructions on how to stay Python 3.1 compatible are included
     with the documentation).

Vedi anche
..........

PEP 3147(1) - PYC Repository Directories

     PEP written by Barry Warsaw.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3147/


File: python.info,  Node: PEP 3149 ABI Version Tagged so Files,  Next: PEP 3333 Python Web Server Gateway Interface v1 0 1,  Prev: PEP 3147 PYC Repository Directories,  Up: What’s New In Python 3 2

1.13.6 PEP 3149: ABI Version Tagged .so Files
---------------------------------------------

The PYC repository directory allows multiple bytecode cache files to be
co-located.  This PEP implements a similar mechanism for shared object
files by giving them a common directory and distinct names for each
version.

The common directory is «pyshared» and the file names are made distinct
by identifying the Python implementation (such as CPython, PyPy, Jython,
etc.), the major and minor version numbers, and optional build flags
(such as «d» for debug, «m» for pymalloc, «u» for wide-unicode).  For an
arbitrary package «foo», you may see these files when the distribution
package is installed:

     /usr/share/pyshared/foo.cpython-32m.so
     /usr/share/pyshared/foo.cpython-33md.so

In Python itself, the tags are accessible from functions in the *note
sysconfig: e1. module:

     >>> import sysconfig
     >>> sysconfig.get_config_var('SOABI')       # find the version tag
     'cpython-32mu'
     >>> sysconfig.get_config_var('EXT_SUFFIX')  # find the full filename extension
     '.cpython-32mu.so'

Vedi anche
..........

PEP 3149(1) - ABI Version Tagged .so Files

     PEP written by Barry Warsaw.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3149/


File: python.info,  Node: PEP 3333 Python Web Server Gateway Interface v1 0 1,  Next: Other Language Changes<11>,  Prev: PEP 3149 ABI Version Tagged so Files,  Up: What’s New In Python 3 2

1.13.7 PEP 3333: Python Web Server Gateway Interface v1.0.1
-----------------------------------------------------------

This informational PEP clarifies how bytes/text issues are to be handled
by the WSGI protocol.  The challenge is that string handling in Python 3
is most conveniently handled with the *note str: 169. type even though
the HTTP protocol is itself bytes oriented.

The PEP differentiates so-called 'native strings' that are used for
request/response headers and metadata versus 'byte strings' which are
used for the bodies of requests and responses.

The 'native strings' are always of type *note str: 169. but are
restricted to code points between 'U+0000' through 'U+00FF' which are
translatable to bytes using 'Latin-1' encoding.  These strings are used
for the keys and values in the environment dictionary and for response
headers and statuses in the ‘start_response()’ function.  They must
follow RFC 2616(1) with respect to encoding.  That is, they must either
be 'ISO-8859-1' characters or use RFC 2047(2) MIME encoding.

For developers porting WSGI applications from Python 2, here are the
salient points:

   * If the app already used strings for headers in Python 2, no change
     is needed.

   * If instead, the app encoded output headers or decoded input
     headers, then the headers will need to be re-encoded to Latin-1.
     For example, an output header encoded in utf-8 was using
     ‘h.encode('utf-8')’ now needs to convert from bytes to native
     strings using ‘h.encode('utf-8').decode('latin-1')’.

   * Values yielded by an application or sent using the ‘write()’ method
     must be byte strings.  The ‘start_response()’ function and environ
     must use native strings.  The two cannot be mixed.

For server implementers writing CGI-to-WSGI pathways or other CGI-style
protocols, the users must to be able access the environment using native
strings even though the underlying platform may have a different
convention.  To bridge this gap, the *note wsgiref: 11e. module has a
new function, *note wsgiref.handlers.read_environ(): 13c1. for
transcoding CGI variables from *note os.environ: 259. into native
strings and returning a new dictionary.

Vedi anche
..........

PEP 3333(3) - Python Web Server Gateway Interface v1.0.1

     PEP written by Phillip Eby.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2616.html

   (2) https://datatracker.ietf.org/doc/html/rfc2047.html

   (3) https://peps.python.org/pep-3333/


File: python.info,  Node: Other Language Changes<11>,  Next: New Improved and Deprecated Modules,  Prev: PEP 3333 Python Web Server Gateway Interface v1 0 1,  Up: What’s New In Python 3 2

1.13.8 Other Language Changes
-----------------------------

Some smaller changes made to the core Python language are:

   * String formatting for *note format(): 199. and *note str.format():
     834. gained new capabilities for the format character '#'.
     Previously, for integers in binary, octal, or hexadecimal, it
     caused the output to be prefixed with “0b”, “0o”, or “0x”
     respectively.  Now it can also handle floats, complex, and Decimal,
     causing the output to always have a decimal point even when no
     digits follow it.

          >>> format(20, '#o')
          '0o24'
          >>> format(12.34, '#5.0f')
          '  12.'

     (Suggested by Mark Dickinson and implemented by Eric Smith in
     bpo-7094(1).)

   * There is also a new *note str.format_map(): fd9. method that
     extends the capabilities of the existing *note str.format(): 834.
     method by accepting arbitrary *note mapping: 13c3. objects.  This
     new method makes it possible to use string formatting with any of
     Python’s many dictionary-like objects such as *note defaultdict:
     13c4, *note Shelf: 119d, *note ConfigParser: 4df, or *note dbm: 35.
     It is also useful with custom *note dict: 183. subclasses that
     normalize keys before look-up or that supply a *note __missing__():
     13c5. method for unknown keys:

          >>> import shelve
          >>> d = shelve.open('tmp.shl')
          >>> 'The {project_name} status is {status} as of {date}'.format_map(d)
          'The testing project status is green as of February 15, 2011'

          >>> class LowerCasedDict(dict):
          ...     def __getitem__(self, key):
          ...         return dict.__getitem__(self, key.lower())
          ...
          >>> lcd = LowerCasedDict(part='widgets', quantity=10)
          >>> 'There are {QUANTITY} {Part} in stock'.format_map(lcd)
          'There are 10 widgets in stock'

          >>> class PlaceholderDict(dict):
          ...     def __missing__(self, key):
          ...         return '<{}>'.format(key)
          ...
          >>> 'Hello {name}, welcome to {location}'.format_map(PlaceholderDict())
          'Hello <name>, welcome to <location>'

     (Suggested by Raymond Hettinger and implemented by Eric Smith in
     bpo-6081(2).)

   * The interpreter can now be started with a quiet option, ‘-q’, to
     prevent the copyright and version information from being displayed
     in the interactive mode.  The option can be introspected using the
     *note sys.flags: 89d. attribute:

          $ python -q
          >>> sys.flags
          sys.flags(debug=0, division_warning=0, inspect=0, interactive=0,
          optimize=0, dont_write_bytecode=0, no_user_site=0, no_site=0,
          ignore_environment=0, verbose=0, bytes_warning=0, quiet=1)

     (Contributed by Marcin Wojdyr in bpo-1772833(3)).

   * The *note hasattr(): 6fa. function works by calling *note
     getattr(): dcc. and detecting whether an exception is raised.  This
     technique allows it to detect methods created dynamically by *note
     __getattr__(): 6fb. or *note __getattribute__(): dcd. which would
     otherwise be absent from the class dictionary.  Formerly, 'hasattr'
     would catch any exception, possibly masking genuine errors.  Now,
     'hasattr' has been tightened to only catch *note AttributeError:
     5f0. and let other exceptions pass through:

          >>> class A:
          ...     @property
          ...     def f(self):
          ...         return 1 // 0
          ...
          >>> a = A()
          >>> hasattr(a, 'f')
          Traceback (most recent call last):
            ...
          ZeroDivisionError: integer division or modulo by zero

     (Discovered by Yury Selivanov and fixed by Benjamin Peterson;
     bpo-9666(4).)

   * The *note str(): 169. of a float or complex number is now the same
     as its *note repr(): 1c1.  Previously, the *note str(): 169. form
     was shorter but that just caused confusion and is no longer needed
     now that the shortest possible *note repr(): 1c1. is displayed by
     default:

          >>> import math
          >>> repr(math.pi)
          '3.141592653589793'
          >>> str(math.pi)
          '3.141592653589793'

     (Proposed and implemented by Mark Dickinson; bpo-9337(5).)

   * *note memoryview: 165. objects now have a *note release(): 13c6.
     method and they also now support the context management protocol.
     This allows timely release of any resources that were acquired when
     requesting a buffer from the original object.

          >>> with memoryview(b'abcdefgh') as v:
          ...     print(v.tolist())
          [97, 98, 99, 100, 101, 102, 103, 104]

     (Added by Antoine Pitrou; bpo-9757(6).)

   * Previously it was illegal to delete a name from the local namespace
     if it occurs as a free variable in a nested block:

          def outer(x):
              def inner():
                  return x
              inner()
              del x

     This is now allowed.  Remember that the target of an *note except:
     1ab. clause is cleared, so this code which used to work with Python
     2.6, raised a *note SyntaxError: 18e. with Python 3.1 and now works
     again:

          def f():
              def print_error():
                  print(e)
              try:
                  something
              except Exception as e:
                  print_error()
                  # implicit "del e" here

     (See bpo-4617(7).)

   * *note Struct sequence types: 13c7. are now subclasses of tuple.
     This means that C structures like those returned by *note
     os.stat(): 26d, *note time.gmtime(): 13c8, and *note
     sys.version_info: 8b0. now work like a *note named tuple: 85f. and
     now work with functions and methods that expect a tuple as an
     argument.  This is a big step forward in making the C structures as
     flexible as their pure Python counterparts:

          >>> import sys
          >>> isinstance(sys.version_info, tuple)
          True
          >>> 'Version %d.%d.%d %s(%d)' % sys.version_info
          'Version 3.2.0 final(0)'

     (Suggested by Arfrever Frehtes Taifersar Arahesis and implemented
     by Benjamin Peterson in bpo-8413(8).)

   * Warnings are now easier to control using the *note PYTHONWARNINGS:
     da5. environment variable as an alternative to using ‘-W’ at the
     command line:

          $ export PYTHONWARNINGS='ignore::RuntimeWarning::,once::UnicodeWarning::'

     (Suggested by Barry Warsaw and implemented by Philip Jenvey in
     bpo-7301(9).)

   * A new warning category, *note ResourceWarning: 54d, has been added.
     It is emitted when potential issues with resource consumption or
     cleanup are detected.  It is silenced by default in normal release
     builds but can be enabled through the means provided by the *note
     warnings: 118. module, or on the command line.

     A *note ResourceWarning: 54d. is issued at interpreter shutdown if
     the *note gc.garbage: 13c9. list isn’t empty, and if *note
     gc.DEBUG_UNCOLLECTABLE: 13ca. is set, all uncollectable objects are
     printed.  This is meant to make the programmer aware that their
     code contains object finalization issues.

     A *note ResourceWarning: 54d. is also issued when a *note file
     object: 13cb. is destroyed without having been explicitly closed.
     While the deallocator for such object ensures it closes the
     underlying operating system resource (usually, a file descriptor),
     the delay in deallocating the object could produce various issues,
     especially under Windows.  Here is an example of enabling the
     warning from the command line:

          $ python -q -Wdefault
          >>> f = open("foo", "wb")
          >>> del f
          __main__:1: ResourceWarning: unclosed file <_io.BufferedWriter name='foo'>

     (Added by Antoine Pitrou and Georg Brandl in bpo-10093(10) and
     bpo-477863(11).)

   * *note range: b3f. objects now support 'index' and 'count' methods.
     This is part of an effort to make more objects fully implement the
     *note collections.Sequence: 13cc. *note abstract base class: 13be.
     As a result, the language will have a more uniform API. In
     addition, *note range: b3f. objects now support slicing and
     negative indices, even with values larger than *note sys.maxsize:
     13cd.  This makes 'range' more interoperable with lists:

          >>> range(0, 100, 2).count(10)
          1
          >>> range(0, 100, 2).index(10)
          5
          >>> range(0, 100, 2)[5]
          10
          >>> range(0, 100, 2)[0:5]
          range(0, 10, 2)

     (Contributed by Daniel Stutzbach in bpo-9213(12), by Alexander
     Belopolsky in bpo-2690(13), and by Nick Coghlan in bpo-10889(14).)

   * The *note callable(): 13ce. builtin function from Py2.x was
     resurrected.  It provides a concise, readable alternative to using
     an *note abstract base class: 13be. in an expression like
     ‘isinstance(x, collections.Callable)’:

          >>> callable(max)
          True
          >>> callable(20)
          False

     (See bpo-10518(15).)

   * Python’s import mechanism can now load modules installed in
     directories with non-ASCII characters in the path name.  This
     solved an aggravating problem with home directories for users with
     non-ASCII characters in their usernames.

     (Required extensive work by Victor Stinner in bpo-9425(16).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=7094

   (2) https://bugs.python.org/issue?@action=redirect&bpo=6081

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1772833

   (4) https://bugs.python.org/issue?@action=redirect&bpo=9666

   (5) https://bugs.python.org/issue?@action=redirect&bpo=9337

   (6) https://bugs.python.org/issue?@action=redirect&bpo=9757

   (7) https://bugs.python.org/issue?@action=redirect&bpo=4617

   (8) https://bugs.python.org/issue?@action=redirect&bpo=8413

   (9) https://bugs.python.org/issue?@action=redirect&bpo=7301

   (10) https://bugs.python.org/issue?@action=redirect&bpo=10093

   (11) https://bugs.python.org/issue?@action=redirect&bpo=477863

   (12) https://bugs.python.org/issue?@action=redirect&bpo=9213

   (13) https://bugs.python.org/issue?@action=redirect&bpo=2690

   (14) https://bugs.python.org/issue?@action=redirect&bpo=10889

   (15) https://bugs.python.org/issue?@action=redirect&bpo=10518

   (16) https://bugs.python.org/issue?@action=redirect&bpo=9425


File: python.info,  Node: New Improved and Deprecated Modules,  Next: Multi-threading,  Prev: Other Language Changes<11>,  Up: What’s New In Python 3 2

1.13.9 New, Improved, and Deprecated Modules
--------------------------------------------

Python’s standard library has undergone significant maintenance efforts
and quality improvements.

The biggest news for Python 3.2 is that the *note email: 3f. package,
*note mailbox: 8f. module, and ‘nntplib’ modules now work correctly with
the bytes/text model in Python 3.  For the first time, there is correct
handling of messages with mixed encodings.

Throughout the standard library, there has been more careful attention
to encodings and text versus bytes issues.  In particular, interactions
with the operating system are now better able to exchange non-ASCII data
using the Windows MBCS encoding, locale-aware encodings, or UTF-8.

Another significant win is the addition of substantially better support
for 'SSL' connections and security certificates.

In addition, more classes now implement a *note context manager: 1e1. to
support convenient and reliable resource clean-up using a *note with:
186. statement.

* Menu:

* email: email<7>.
* elementtree::
* functools: functools<8>.
* itertools: itertools<8>.
* collections: collections<8>.
* threading: threading<10>.
* datetime and time::
* math: math<10>.
* abc: abc<3>.
* io: io<9>.
* reprlib::
* logging: logging<8>.
* csv: csv<4>.
* contextlib: contextlib<8>.
* decimal and fractions::
* ftp::
* popen::
* select: select<3>.
* gzip and zipfile::
* tarfile: tarfile<10>.
* hashlib: hashlib<7>.
* ast: ast<7>.
* os: os<14>.
* shutil: shutil<8>.
* sqlite3: sqlite3<12>.
* html: html<3>.
* socket: socket<12>.
* ssl: ssl<13>.
* nntp::
* certificates::
* imaplib: imaplib<5>.
* http.client: http client<4>.
* unittest: unittest<12>.
* random: random<5>.
* poplib: poplib<4>.
* asyncore: asyncore<2>.
* tempfile: tempfile<5>.
* inspect: inspect<11>.
* pydoc: pydoc<7>.
* dis: dis<6>.
* dbm: dbm<7>.
* ctypes: ctypes<4>.
* site: site<4>.
* sysconfig: sysconfig<4>.
* pdb: pdb<10>.
* configparser: configparser<6>.
* urllib.parse: urllib parse<6>.
* mailbox::
* turtledemo::


File: python.info,  Node: email<7>,  Next: elementtree,  Up: New Improved and Deprecated Modules

1.13.9.1 email
..............

The usability of the *note email: 3f. package in Python 3 has been
mostly fixed by the extensive efforts of R. David Murray.  The problem
was that emails are typically read and stored in the form of *note
bytes: 192. rather than *note str: 169. text, and they may contain
multiple encodings within a single email.  So, the email package had to
be extended to parse and generate email messages in bytes format.

   * New functions *note message_from_bytes(): 13d1. and *note
     message_from_binary_file(): 13d2, and new classes *note
     BytesFeedParser: 13d3. and *note BytesParser: 13d4. allow binary
     message data to be parsed into model objects.

   * Given bytes input to the model, *note get_payload(): 13d5. will by
     default decode a message body that has a
     ‘Content-Transfer-Encoding’ of '8bit' using the charset specified
     in the MIME headers and return the resulting string.

   * Given bytes input to the model, *note Generator: 13d6. will convert
     message bodies that have a ‘Content-Transfer-Encoding’ of '8bit' to
     instead have a '7bit' ‘Content-Transfer-Encoding’.

     Headers with unencoded non-ASCII bytes are deemed to be RFC
     2047(1)-encoded using the 'unknown-8bit' character set.

   * A new class *note BytesGenerator: 13d7. produces bytes as output,
     preserving any unchanged non-ASCII data that was present in the
     input used to build the model, including message bodies with a
     ‘Content-Transfer-Encoding’ of '8bit'.

   * The *note smtplib: cf. *note SMTP: b29. class now accepts a byte
     string for the 'msg' argument to the *note sendmail(): 105b.
     method, and a new method, *note send_message(): 105c. accepts a
     *note Message: 581. object and can optionally obtain the
     'from_addr' and 'to_addrs' addresses directly from the object.

(Proposed and implemented by R. David Murray, bpo-4661(2) and
bpo-10321(3).)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2047.html

   (2) https://bugs.python.org/issue?@action=redirect&bpo=4661

   (3) https://bugs.python.org/issue?@action=redirect&bpo=10321


File: python.info,  Node: elementtree,  Next: functools<8>,  Prev: email<7>,  Up: New Improved and Deprecated Modules

1.13.9.2 elementtree
....................

The *note xml.etree.ElementTree: 12b. package and its
‘xml.etree.cElementTree’ counterpart have been updated to version 1.3.

Several new and useful functions and methods have been added:

   * *note xml.etree.ElementTree.fromstringlist(): 13d9. which builds an
     XML document from a sequence of fragments

   * *note xml.etree.ElementTree.register_namespace(): 13da. for
     registering a global namespace prefix

   * *note xml.etree.ElementTree.tostringlist(): 11f8. for string
     representation including all sublists

   * *note xml.etree.ElementTree.Element.extend(): 13db. for appending a
     sequence of zero or more elements

   * *note xml.etree.ElementTree.Element.iterfind(): 13dc. searches an
     element and subelements

   * *note xml.etree.ElementTree.Element.itertext(): 13dd. creates a
     text iterator over an element and its subelements

   * *note xml.etree.ElementTree.TreeBuilder.end(): 13de. closes the
     current element

   * *note xml.etree.ElementTree.TreeBuilder.doctype(): c90. handles a
     doctype declaration

Two methods have been deprecated:

   * ‘xml.etree.ElementTree.getchildren()’ use ‘list(elem)’ instead.

   * ‘xml.etree.ElementTree.getiterator()’ use ‘Element.iter’ instead.

For details of the update, see Introducing ElementTree(1) on Fredrik
Lundh’s website.

(Contributed by Florent Xicluna and Fredrik Lundh, bpo-6472(2).)

   ---------- Footnotes ----------

   (1) 
https://web.archive.org/web/20200703234532/http://effbot.org/zone/elementtree-13-intro.htm

   (2) https://bugs.python.org/issue?@action=redirect&bpo=6472


File: python.info,  Node: functools<8>,  Next: itertools<8>,  Prev: elementtree,  Up: New Improved and Deprecated Modules

1.13.9.3 functools
..................

   * The *note functools: 63. module includes a new decorator for
     caching function calls.  *note functools.lru_cache(): be4. can save
     repeated queries to an external resource whenever the results are
     expected to be the same.

     For example, adding a caching decorator to a database query
     function can save database accesses for popular searches:

          >>> import functools
          >>> @functools.lru_cache(maxsize=300)
          ... def get_phone_number(name):
          ...     c = conn.cursor()
          ...     c.execute('SELECT phonenumber FROM phonelist WHERE name=?', (name,))
          ...     return c.fetchone()[0]

          >>> for name in user_requests:
          ...     get_phone_number(name)        # cached lookup

     To help with choosing an effective cache size, the wrapped function
     is instrumented for tracking cache statistics:

          >>> get_phone_number.cache_info()
          CacheInfo(hits=4805, misses=980, maxsize=300, currsize=300)

     If the phonelist table gets updated, the outdated contents of the
     cache can be cleared with:

          >>> get_phone_number.cache_clear()

     (Contributed by Raymond Hettinger and incorporating design ideas
     from Jim Baker, Miki Tebeka, and Nick Coghlan; see recipe
     498245(1), recipe 577479(2), bpo-10586(3), and bpo-10593(4).)

   * The *note functools.wraps(): 115f. decorator now adds a
     ‘__wrapped__’ attribute pointing to the original callable function.
     This allows wrapped functions to be introspected.  It also copies
     *note __annotations__: 13e0. if defined.  And now it also
     gracefully skips over missing attributes such as *note __doc__:
     13e1. which might not be defined for the wrapped callable.

     In the above example, the cache can be removed by recovering the
     original function:

          >>> get_phone_number = get_phone_number.__wrapped__    # uncached function

     (By Nick Coghlan and Terrence Cole; bpo-9567(5), bpo-3445(6), and
     bpo-8814(7).)

   * To help write classes with rich comparison methods, a new decorator
     *note functools.total_ordering(): 1144. will use existing equality
     and inequality methods to fill in the remaining methods.

     For example, supplying '__eq__' and '__lt__' will enable *note
     total_ordering(): 1144. to fill-in '__le__', '__gt__' and '__ge__':

          @total_ordering
          class Student:
              def __eq__(self, other):
                  return ((self.lastname.lower(), self.firstname.lower()) ==
                          (other.lastname.lower(), other.firstname.lower()))

              def __lt__(self, other):
                  return ((self.lastname.lower(), self.firstname.lower()) <
                          (other.lastname.lower(), other.firstname.lower()))

     With the 'total_ordering' decorator, the remaining comparison
     methods are filled in automatically.

     (Contributed by Raymond Hettinger.)

   * To aid in porting programs from Python 2, the *note
     functools.cmp_to_key(): 13e2. function converts an old-style
     comparison function to modern *note key function: 1008.:

          >>> # locale-aware sort order
          >>> sorted(iterable, key=cmp_to_key(locale.strcoll))

     For sorting examples and a brief sorting tutorial, see the Sorting
     HowTo(8) tutorial.

     (Contributed by Raymond Hettinger.)

   ---------- Footnotes ----------

   (1) 
https://code.activestate.com/recipes/498245-lru-and-lfu-cache-decorators/

   (2) 
https://code.activestate.com/recipes/577479-simple-caching-decorator/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=10586

   (4) https://bugs.python.org/issue?@action=redirect&bpo=10593

   (5) https://bugs.python.org/issue?@action=redirect&bpo=9567

   (6) https://bugs.python.org/issue?@action=redirect&bpo=3445

   (7) https://bugs.python.org/issue?@action=redirect&bpo=8814

   (8) https://wiki.python.org/moin/HowTo/Sorting/


File: python.info,  Node: itertools<8>,  Next: collections<8>,  Prev: functools<8>,  Up: New Improved and Deprecated Modules

1.13.9.4 itertools
..................

   * The *note itertools: 85. module has a new *note accumulate(): bf2.
     function modeled on APL’s 'scan' operator and Numpy’s 'accumulate'
     function:

          >>> from itertools import accumulate
          >>> list(accumulate([8, 2, 50]))
          [8, 10, 60]

          >>> prob_dist = [0.1, 0.4, 0.2, 0.3]
          >>> list(accumulate(prob_dist))      # cumulative probability distribution
          [0.1, 0.5, 0.7, 1.0]

     For an example using *note accumulate(): bf2, see the *note
     examples for the random module: 13e4.

     (Contributed by Raymond Hettinger and incorporating design
     suggestions from Mark Dickinson.)


File: python.info,  Node: collections<8>,  Next: threading<10>,  Prev: itertools<8>,  Up: New Improved and Deprecated Modules

1.13.9.5 collections
....................

   * The *note collections.Counter: 1299. class now has two forms of
     in-place subtraction, the existing '-=' operator for saturating
     subtraction(1) and the new *note subtract(): 13e6. method for
     regular subtraction.  The former is suitable for multisets(2) which
     only have positive counts, and the latter is more suitable for use
     cases that allow negative counts:

          >>> from collections import Counter
          >>> tally = Counter(dogs=5, cats=3)
          >>> tally -= Counter(dogs=2, cats=8)    # saturating subtraction
          >>> tally
          Counter({'dogs': 3})

          >>> tally = Counter(dogs=5, cats=3)
          >>> tally.subtract(dogs=2, cats=8)      # regular subtraction
          >>> tally
          Counter({'dogs': 3, 'cats': -5})

     (Contributed by Raymond Hettinger.)

   * The *note collections.OrderedDict: 7f4. class has a new method
     *note move_to_end(): 13e7. which takes an existing key and moves it
     to either the first or last position in the ordered sequence.

     The default is to move an item to the last position.  This is
     equivalent of renewing an entry with ‘od[k] = od.pop(k)’.

     A fast move-to-end operation is useful for resequencing entries.
     For example, an ordered dictionary can be used to track order of
     access by aging entries from the oldest to the most recently
     accessed.

          >>> from collections import OrderedDict
          >>> d = OrderedDict.fromkeys(['a', 'b', 'X', 'd', 'e'])
          >>> list(d)
          ['a', 'b', 'X', 'd', 'e']
          >>> d.move_to_end('X')
          >>> list(d)
          ['a', 'b', 'd', 'e', 'X']

     (Contributed by Raymond Hettinger.)

   * The *note collections.deque: 7f5. class grew two new methods *note
     count(): 13e8. and *note reverse(): 13e9. that make them more
     substitutable for *note list: 24d. objects:

          >>> from collections import deque
          >>> d = deque('simsalabim')
          >>> d.count('s')
          2
          >>> d.reverse()
          >>> d
          deque(['m', 'i', 'b', 'a', 'l', 'a', 's', 'm', 'i', 's'])

     (Contributed by Raymond Hettinger.)

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Saturation_arithmetic

   (2) https://en.wikipedia.org/wiki/Multiset


File: python.info,  Node: threading<10>,  Next: datetime and time,  Prev: collections<8>,  Up: New Improved and Deprecated Modules

1.13.9.6 threading
..................

The *note threading: f3. module has a new *note Barrier: 13eb.
synchronization class for making multiple threads wait until all of them
have reached a common barrier point.  Barriers are useful for making
sure that a task with multiple preconditions does not run until all of
the predecessor tasks are complete.

Barriers can work with an arbitrary number of threads.  This is a
generalization of a Rendezvous(1) which is defined for only two threads.

Implemented as a two-phase cyclic barrier, *note Barrier: 13eb. objects
are suitable for use in loops.  The separate 'filling' and 'draining'
phases assure that all threads get released (drained) before any one of
them can loop back and re-enter the barrier.  The barrier fully resets
after each cycle.

Example of using barriers:

     from threading import Barrier, Thread

     def get_votes(site):
         ballots = conduct_election(site)
         all_polls_closed.wait()        # do not count until all polls are closed
         totals = summarize(ballots)
         publish(site, totals)

     all_polls_closed = Barrier(len(sites))
     for site in sites:
         Thread(target=get_votes, args=(site,)).start()

In this example, the barrier enforces a rule that votes cannot be
counted at any polling site until all polls are closed.  Notice how a
solution with a barrier is similar to one with *note
threading.Thread.join(): 13ec, but the threads stay alive and continue
to do work (summarizing ballots) after the barrier point is crossed.

If any of the predecessor tasks can hang or be delayed, a barrier can be
created with an optional 'timeout' parameter.  Then if the timeout
period elapses before all the predecessor tasks reach the barrier point,
all waiting threads are released and a *note BrokenBarrierError: 13ed.
exception is raised:

     def get_votes(site):
         ballots = conduct_election(site)
         try:
             all_polls_closed.wait(timeout=midnight - time.now())
         except BrokenBarrierError:
             lockbox = seal_ballots(ballots)
             queue.put(lockbox)
         else:
             totals = summarize(ballots)
             publish(site, totals)

In this example, the barrier enforces a more robust rule.  If some
election sites do not finish before midnight, the barrier times-out and
the ballots are sealed and deposited in a queue for later handling.

See Barrier Synchronization Patterns(2) for more examples of how
barriers can be used in parallel computing.  Also, there is a simple but
thorough explanation of barriers in The Little Book of Semaphores(3),
'section 3.6'.

(Contributed by Kristján Valur Jónsson with an API review by Jeffrey
Yasskin in bpo-8777(4).)

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Synchronous_rendezvous

   (2) 
https://osl.cs.illinois.edu/media/papers/karmani-2009-barrier_synchronization_pattern.pdf

   (3) https://greenteapress.com/semaphores/LittleBookOfSemaphores.pdf

   (4) https://bugs.python.org/issue?@action=redirect&bpo=8777


File: python.info,  Node: datetime and time,  Next: math<10>,  Prev: threading<10>,  Up: New Improved and Deprecated Modules

1.13.9.7 datetime and time
..........................

   * The *note datetime: 34. module has a new type *note timezone: 12c7.
     that implements the *note tzinfo: 7f7. interface by returning a
     fixed UTC offset and timezone name.  This makes it easier to create
     timezone-aware datetime objects:

          >>> from datetime import datetime, timezone

          >>> datetime.now(timezone.utc)
          datetime.datetime(2010, 12, 8, 21, 4, 2, 923754, tzinfo=datetime.timezone.utc)

          >>> datetime.strptime("01/01/2000 12:00 +0000", "%m/%d/%Y %H:%M %z")
          datetime.datetime(2000, 1, 1, 12, 0, tzinfo=datetime.timezone.utc)

   * Also, *note timedelta: bc5. objects can now be multiplied by *note
     float: 196. and divided by *note float: 196. and *note int: 19b.
     objects.  And *note timedelta: bc5. objects can now divide one
     another.

   * The *note datetime.date.strftime(): e91. method is no longer
     restricted to years after 1900.  The new supported year range is
     from 1000 to 9999 inclusive.

   * Whenever a two-digit year is used in a time tuple, the
     interpretation has been governed by ‘time.accept2dyear’.  The
     default is ‘True’ which means that for a two-digit year, the
     century is guessed according to the POSIX rules governing the ‘%y’
     strptime format.

     Starting with Py3.2, use of the century guessing heuristic will
     emit a *note DeprecationWarning: 1a3.  Instead, it is recommended
     that ‘time.accept2dyear’ be set to ‘False’ so that large date
     ranges can be used without guesswork:

          >>> import time, warnings
          >>> warnings.resetwarnings()      # remove the default warning filters

          >>> time.accept2dyear = True      # guess whether 11 means 11 or 2011
          >>> time.asctime((11, 1, 1, 12, 34, 56, 4, 1, 0))
          Warning (from warnings module):
            ...
          DeprecationWarning: Century info guessed for a 2-digit year.
          'Fri Jan  1 12:34:56 2011'

          >>> time.accept2dyear = False     # use the full range of allowable dates
          >>> time.asctime((11, 1, 1, 12, 34, 56, 4, 1, 0))
          'Fri Jan  1 12:34:56 11'

     Several functions now have significantly expanded date ranges.
     When ‘time.accept2dyear’ is false, the *note time.asctime(): 13ef.
     function will accept any year that fits in a C int, while the *note
     time.mktime(): 13f0. and *note time.strftime(): 13f1. functions
     will accept the full range supported by the corresponding operating
     system functions.

(Contributed by Alexander Belopolsky and Victor Stinner in
bpo-1289118(1), bpo-5094(2), bpo-6641(3), bpo-2706(4), bpo-1777412(5),
bpo-8013(6), and bpo-10827(7).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1289118

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5094

   (3) https://bugs.python.org/issue?@action=redirect&bpo=6641

   (4) https://bugs.python.org/issue?@action=redirect&bpo=2706

   (5) https://bugs.python.org/issue?@action=redirect&bpo=1777412

   (6) https://bugs.python.org/issue?@action=redirect&bpo=8013

   (7) https://bugs.python.org/issue?@action=redirect&bpo=10827


File: python.info,  Node: math<10>,  Next: abc<3>,  Prev: datetime and time,  Up: New Improved and Deprecated Modules

1.13.9.8 math
.............

The *note math: 92. module has been updated with six new functions
inspired by the C99 standard.

The *note isfinite(): 13f3. function provides a reliable and fast way to
detect special values.  It returns ‘True’ for regular numbers and
‘False’ for 'Nan' or 'Infinity':

     >>> from math import isfinite
     >>> [isfinite(x) for x in (123, 4.56, float('Nan'), float('Inf'))]
     [True, True, False, False]

The *note expm1(): 13f4. function computes ‘e**x-1’ for small values of
'x' without incurring the loss of precision that usually accompanies the
subtraction of nearly equal quantities:

     >>> from math import expm1
     >>> expm1(0.013671875)   # more accurate way to compute e**x-1 for a small x
     0.013765762467652909

The *note erf(): dd5. function computes a probability integral or
Gaussian error function(1).  The complementary error function, *note
erfc(): dd6, is ‘1 - erf(x)’:

     >>> from math import erf, erfc, sqrt
     >>> erf(1.0/sqrt(2.0))   # portion of normal distribution within 1 standard deviation
     0.682689492137086
     >>> erfc(1.0/sqrt(2.0))  # portion of normal distribution outside 1 standard deviation
     0.31731050786291404
     >>> erf(1.0/sqrt(2.0)) + erfc(1.0/sqrt(2.0))
     1.0

The *note gamma(): 13f5. function is a continuous extension of the
factorial function.  See ‘https://en.wikipedia.org/wiki/Gamma_function’
for details.  Because the function is related to factorials, it grows
large even for small values of 'x', so there is also a *note lgamma():
13f6. function for computing the natural logarithm of the gamma
function:

     >>> from math import gamma, lgamma
     >>> gamma(7.0)           # six factorial
     720.0
     >>> lgamma(801.0)        # log(800 factorial)
     4551.950730698041

(Contributed by Mark Dickinson.)

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Error_function


File: python.info,  Node: abc<3>,  Next: io<9>,  Prev: math<10>,  Up: New Improved and Deprecated Modules

1.13.9.9 abc
............

The *note abc: 4. module now supports *note abstractclassmethod(): 128e.
and *note abstractstaticmethod(): 128f.

These tools make it possible to define an *note abstract base class:
13be. that requires a particular *note classmethod(): 48f. or *note
staticmethod(): 453. to be implemented:

     class Temperature(metaclass=abc.ABCMeta):
         @abc.abstractclassmethod
         def from_fahrenheit(cls, t):
             ...
         @abc.abstractclassmethod
         def from_celsius(cls, t):
             ...

(Patch submitted by Daniel Urban; bpo-5867(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5867


File: python.info,  Node: io<9>,  Next: reprlib,  Prev: abc<3>,  Up: New Improved and Deprecated Modules

1.13.9.10 io
............

The *note io.BytesIO: 10a6. has a new method, *note getbuffer(): 13f9,
which provides functionality similar to *note memoryview(): 165.  It
creates an editable view of the data without making a copy.  The
buffer’s random access and support for slice notation are well-suited to
in-place editing:

     >>> REC_LEN, LOC_START, LOC_LEN = 34, 7, 11

     >>> def change_location(buffer, record_number, location):
     ...     start = record_number * REC_LEN + LOC_START
     ...     buffer[start: start+LOC_LEN] = location

     >>> import io

     >>> byte_stream = io.BytesIO(
     ...     b'G3805  storeroom  Main chassis    '
     ...     b'X7899  shipping   Reserve cog     '
     ...     b'L6988  receiving  Primary sprocket'
     ... )
     >>> buffer = byte_stream.getbuffer()
     >>> change_location(buffer, 1, b'warehouse  ')
     >>> change_location(buffer, 0, b'showroom   ')
     >>> print(byte_stream.getvalue())
     b'G3805  showroom   Main chassis    '
     b'X7899  warehouse  Reserve cog     '
     b'L6988  receiving  Primary sprocket'

(Contributed by Antoine Pitrou in bpo-5506(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5506


File: python.info,  Node: reprlib,  Next: logging<8>,  Prev: io<9>,  Up: New Improved and Deprecated Modules

1.13.9.11 reprlib
.................

When writing a *note __repr__(): 830. method for a custom container, it
is easy to forget to handle the case where a member refers back to the
container itself.  Python’s builtin objects such as *note list: 24d. and
*note set: 184. handle self-reference by displaying «…» in the recursive
part of the representation string.

To help write such *note __repr__(): 830. methods, the *note reprlib:
c0. module has a new decorator, *note recursive_repr(): 13fb, for
detecting recursive calls to ‘__repr__()’ and substituting a placeholder
string instead:

     >>> class MyList(list):
     ...     @recursive_repr()
     ...     def __repr__(self):
     ...         return '<' + '|'.join(map(repr, self)) + '>'
     ...
     >>> m = MyList('abc')
     >>> m.append(m)
     >>> m.append('x')
     >>> print(m)
     <'a'|'b'|'c'|...|'x'>

(Contributed by Raymond Hettinger in bpo-9826(1) and bpo-9840(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9826

   (2) https://bugs.python.org/issue?@action=redirect&bpo=9840


File: python.info,  Node: logging<8>,  Next: csv<4>,  Prev: reprlib,  Up: New Improved and Deprecated Modules

1.13.9.12 logging
.................

In addition to dictionary-based configuration described above, the *note
logging: 8b. package has many other improvements.

The logging documentation has been augmented by a *note basic tutorial:
13fd, an *note advanced tutorial: 13fe, and a *note cookbook: 13ff. of
logging recipes.  These documents are the fastest way to learn about
logging.

The *note logging.basicConfig(): bf5. set-up function gained a 'style'
argument to support three different types of string formatting.  It
defaults to «%» for traditional %-formatting, can be set to «{» for the
new *note str.format(): 834. style, or can be set to «$» for the
shell-style formatting provided by *note string.Template: 898.  The
following three configurations are equivalent:

     >>> from logging import basicConfig
     >>> basicConfig(style='%', format="%(name)s -> %(levelname)s: %(message)s")
     >>> basicConfig(style='{', format="{name} -> {levelname} {message}")
     >>> basicConfig(style='$', format="$name -> $levelname: $message")

If no configuration is set-up before a logging event occurs, there is
now a default configuration using a *note StreamHandler: 1400. directed
to *note sys.stderr: b35. for events of ‘WARNING’ level or higher.
Formerly, an event occurring before a configuration was set-up would
either raise an exception or silently drop the event depending on the
value of *note logging.raiseExceptions: 1401.  The new default handler
is stored in *note logging.lastResort: 1402.

The use of filters has been simplified.  Instead of creating a *note
Filter: 1403. object, the predicate can be any Python callable that
returns ‘True’ or ‘False’.

There were a number of other improvements that add flexibility and
simplify configuration.  See the module documentation for a full listing
of changes in Python 3.2.


File: python.info,  Node: csv<4>,  Next: contextlib<8>,  Prev: logging<8>,  Up: New Improved and Deprecated Modules

1.13.9.13 csv
.............

The *note csv: 2d. module now supports a new dialect, *note
unix_dialect: 1405, which applies quoting for all fields and a
traditional Unix style with ‘'\n'’ as the line terminator.  The
registered dialect name is ‘unix’.

The *note csv.DictWriter: 1406. has a new method, *note writeheader():
1407. for writing-out an initial row to document the field names:

     >>> import csv, sys
     >>> w = csv.DictWriter(sys.stdout, ['name', 'dept'], dialect='unix')
     >>> w.writeheader()
     "name","dept"
     >>> w.writerows([
     ...     {'name': 'tom', 'dept': 'accounting'},
     ...     {'name': 'susan', 'dept': 'Salesl'}])
     "tom","accounting"
     "susan","sales"

(New dialect suggested by Jay Talbot in bpo-5975(1), and the new method
suggested by Ed Abraham in bpo-1537721(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5975

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1537721


File: python.info,  Node: contextlib<8>,  Next: decimal and fractions,  Prev: csv<4>,  Up: New Improved and Deprecated Modules

1.13.9.14 contextlib
....................

There is a new and slightly mind-blowing tool *note ContextDecorator:
1409. that is helpful for creating a *note context manager: 1e1. that
does double duty as a function decorator.

As a convenience, this new functionality is used by *note
contextmanager(): 140a. so that no extra effort is needed to support
both roles.

The basic idea is that both context managers and function decorators can
be used for pre-action and post-action wrappers.  Context managers wrap
a group of statements using a *note with: 186. statement, and function
decorators wrap a group of statements enclosed in a function.  So,
occasionally there is a need to write a pre-action or post-action
wrapper that can be used in either role.

For example, it is sometimes useful to wrap functions or groups of
statements with a logger that can track the time of entry and time of
exit.  Rather than writing both a function decorator and a context
manager for the task, the *note contextmanager(): 140a. provides both
capabilities in a single definition:

     from contextlib import contextmanager
     import logging

     logging.basicConfig(level=logging.INFO)

     @contextmanager
     def track_entry_and_exit(name):
         logging.info('Entering: %s', name)
         yield
         logging.info('Exiting: %s', name)

Formerly, this would have only been usable as a context manager:

     with track_entry_and_exit('widget loader'):
         print('Some time consuming activity goes here')
         load_widget()

Now, it can be used as a decorator as well:

     @track_entry_and_exit('widget loader')
     def activity():
         print('Some time consuming activity goes here')
         load_widget()

Trying to fulfill two roles at once places some limitations on the
technique.  Context managers normally have the flexibility to return an
argument usable by a *note with: 186. statement, but there is no
parallel for function decorators.

In the above example, there is not a clean way for the
'track_entry_and_exit' context manager to return a logging instance for
use in the body of enclosed statements.

(Contributed by Michael Foord in bpo-9110(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9110


File: python.info,  Node: decimal and fractions,  Next: ftp,  Prev: contextlib<8>,  Up: New Improved and Deprecated Modules

1.13.9.15 decimal and fractions
...............................

Mark Dickinson crafted an elegant and efficient scheme for assuring that
different numeric datatypes will have the same hash value whenever their
actual values are equal (bpo-8188(1)):

     assert hash(Fraction(3, 2)) == hash(1.5) == \
            hash(Decimal("1.5")) == hash(complex(1.5, 0))

Some of the hashing details are exposed through a new attribute, *note
sys.hash_info: 1201, which describes the bit width of the hash value,
the prime modulus, the hash values for 'infinity' and 'nan', and the
multiplier used for the imaginary part of a number:

     >>> sys.hash_info
     sys.hash_info(width=64, modulus=2305843009213693951, inf=314159, nan=0, imag=1000003)

An early decision to limit the interoperability of various numeric types
has been relaxed.  It is still unsupported (and ill-advised) to have
implicit mixing in arithmetic expressions such as ‘Decimal('1.1') +
float('1.1')’ because the latter loses information in the process of
constructing the binary float.  However, since existing floating-point
value can be converted losslessly to either a decimal or rational
representation, it makes sense to add them to the constructor and to
support mixed-type comparisons.

   * The *note decimal.Decimal: 1fe. constructor now accepts *note
     float: 196. objects directly so there in no longer a need to use
     the *note from_float(): 140c. method (bpo-8257(2)).

   * Mixed type comparisons are now fully supported so that *note
     Decimal: 1fe. objects can be directly compared with *note float:
     196. and *note fractions.Fraction: 213. (bpo-2531(3) and
     bpo-8188(4)).

Similar changes were made to *note fractions.Fraction: 213. so that the
*note from_float(): 140d. and *note from_decimal(): 140e. methods are no
longer needed (bpo-8294(5)):

     >>> from decimal import Decimal
     >>> from fractions import Fraction
     >>> Decimal(1.1)
     Decimal('1.100000000000000088817841970012523233890533447265625')
     >>> Fraction(1.1)
     Fraction(2476979795053773, 2251799813685248)

Another useful change for the *note decimal: 3a. module is that the
*note Context.clamp: 13a6. attribute is now public.  This is useful in
creating contexts that correspond to the decimal interchange formats
specified in IEEE 754 (see bpo-8540(6)).

(Contributed by Mark Dickinson and Raymond Hettinger.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8188

   (2) https://bugs.python.org/issue?@action=redirect&bpo=8257

   (3) https://bugs.python.org/issue?@action=redirect&bpo=2531

   (4) https://bugs.python.org/issue?@action=redirect&bpo=8188

   (5) https://bugs.python.org/issue?@action=redirect&bpo=8294

   (6) https://bugs.python.org/issue?@action=redirect&bpo=8540


File: python.info,  Node: ftp,  Next: popen,  Prev: decimal and fractions,  Up: New Improved and Deprecated Modules

1.13.9.16 ftp
.............

The *note ftplib.FTP: af8. class now supports the context management
protocol to unconditionally consume *note socket.error: 1258. exceptions
and to close the FTP connection when done:

     >>> from ftplib import FTP
     >>> with FTP("ftp1.at.proftpd.org") as ftp:
             ftp.login()
             ftp.dir()

     '230 Anonymous login ok, restrictions apply.'
     dr-xr-xr-x   9 ftp      ftp           154 May  6 10:43 .
     dr-xr-xr-x   9 ftp      ftp           154 May  6 10:43 ..
     dr-xr-xr-x   5 ftp      ftp          4096 May  6 10:43 CentOS
     dr-xr-xr-x   3 ftp      ftp            18 Jul 10  2008 Fedora

Other file-like objects such as *note mmap.mmap: 51a. and *note
fileinput.input(): a02. also grew auto-closing context managers:

     with fileinput.input(files=('log1.txt', 'log2.txt')) as f:
         for line in f:
             process(line)

(Contributed by Tarek Ziadé and Giampaolo Rodolà in bpo-4972(1), and by
Georg Brandl in bpo-8046(2) and bpo-1286(3).)

The *note FTP_TLS: af9. class now accepts a 'context' parameter, which
is a *note ssl.SSLContext: 357. object allowing bundling SSL
configuration options, certificates and private keys into a single
(potentially long-lived) structure.

(Contributed by Giampaolo Rodolà; bpo-8806(4).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4972

   (2) https://bugs.python.org/issue?@action=redirect&bpo=8046

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1286

   (4) https://bugs.python.org/issue?@action=redirect&bpo=8806


File: python.info,  Node: popen,  Next: select<3>,  Prev: ftp,  Up: New Improved and Deprecated Modules

1.13.9.17 popen
...............

The *note os.popen(): 31a. and *note subprocess.Popen(): 4b8. functions
now support *note with: 186. statements for auto-closing of the file
descriptors.

(Contributed by Antoine Pitrou and Brian Curtin in bpo-7461(1) and
bpo-10554(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=7461

   (2) https://bugs.python.org/issue?@action=redirect&bpo=10554


File: python.info,  Node: select<3>,  Next: gzip and zipfile,  Prev: popen,  Up: New Improved and Deprecated Modules

1.13.9.18 select
................

The *note select: c6. module now exposes a new, constant attribute,
*note PIPE_BUF: 1412, which gives the minimum number of bytes which are
guaranteed not to block when *note select.select(): fa2. says a pipe is
ready for writing.

     >>> import select
     >>> select.PIPE_BUF
     512

(Available on Unix systems.  Patch by Sébastien Sablé in bpo-9862(1))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9862


File: python.info,  Node: gzip and zipfile,  Next: tarfile<10>,  Prev: select<3>,  Up: New Improved and Deprecated Modules

1.13.9.19 gzip and zipfile
..........................

*note gzip.GzipFile: 65c. now implements the *note io.BufferedIOBase:
8a4. *note abstract base class: 13be. (except for ‘truncate()’).  It
also has a *note peek(): 1414. method and supports unseekable as well as
zero-padded file objects.

The *note gzip: 6b. module also gains the *note compress(): 84f. and
*note decompress(): 1415. functions for easier in-memory compression and
decompression.  Keep in mind that text needs to be encoded as *note
bytes: 192. before compressing and decompressing:

     >>> import gzip
     >>> s = 'Three shall be the number thou shalt count, '
     >>> s += 'and the number of the counting shall be three'
     >>> b = s.encode()                        # convert to utf-8
     >>> len(b)
     89
     >>> c = gzip.compress(b)
     >>> len(c)
     77
     >>> gzip.decompress(c).decode()[:42]      # decompress and convert to text
     'Three shall be the number thou shalt count'

(Contributed by Anand B. Pillai in bpo-3488(1); and by Antoine Pitrou,
Nir Aides and Brian Curtin in bpo-9962(2), bpo-1675951(3), bpo-7471(4)
and bpo-2846(5).)

Also, the *note zipfile.ZipExtFile: 65d. class was reworked internally
to represent files stored inside an archive.  The new implementation is
significantly faster and can be wrapped in an *note io.BufferedReader:
1416. object for more speedups.  It also solves an issue where
interleaved calls to 'read' and 'readline' gave the wrong results.

(Patch submitted by Nir Aides in bpo-7610(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=3488

   (2) https://bugs.python.org/issue?@action=redirect&bpo=9962

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1675951

   (4) https://bugs.python.org/issue?@action=redirect&bpo=7471

   (5) https://bugs.python.org/issue?@action=redirect&bpo=2846

   (6) https://bugs.python.org/issue?@action=redirect&bpo=7610


File: python.info,  Node: tarfile<10>,  Next: hashlib<7>,  Prev: gzip and zipfile,  Up: New Improved and Deprecated Modules

1.13.9.20 tarfile
.................

The *note TarFile: 1418. class can now be used as a context manager.  In
addition, its *note add(): df0. method has a new option, 'filter', that
controls which files are added to the archive and allows the file
metadata to be edited.

The new 'filter' option replaces the older, less flexible 'exclude'
parameter which is now deprecated.  If specified, the optional 'filter'
parameter needs to be a *note keyword argument: f10.  The user-supplied
filter function accepts a *note TarInfo: 1419. object and returns an
updated *note TarInfo: 1419. object, or if it wants the file to be
excluded, the function can return ‘None’:

     >>> import tarfile, glob

     >>> def myfilter(tarinfo):
     ...     if tarinfo.isfile():             # only save real files
     ...         tarinfo.uname = 'monty'      # redact the user name
     ...         return tarinfo

     >>> with tarfile.open(name='myarchive.tar.gz', mode='w:gz') as tf:
     ...     for filename in glob.glob('*.txt'):
     ...         tf.add(filename, filter=myfilter)
     ...     tf.list()
     -rw-r--r-- monty/501        902 2011-01-26 17:59:11 annotations.txt
     -rw-r--r-- monty/501        123 2011-01-26 17:59:11 general_questions.txt
     -rw-r--r-- monty/501       3514 2011-01-26 17:59:11 prion.txt
     -rw-r--r-- monty/501        124 2011-01-26 17:59:11 py_todo.txt
     -rw-r--r-- monty/501       1399 2011-01-26 17:59:11 semaphore_notes.txt

(Proposed by Tarek Ziadé and implemented by Lars Gustäbel in
bpo-6856(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6856


File: python.info,  Node: hashlib<7>,  Next: ast<7>,  Prev: tarfile<10>,  Up: New Improved and Deprecated Modules

1.13.9.21 hashlib
.................

The *note hashlib: 6c. module has two new constant attributes listing
the hashing algorithms guaranteed to be present in all implementations
and those available on the current implementation:

     >>> import hashlib

     >>> hashlib.algorithms_guaranteed
     {'sha1', 'sha224', 'sha384', 'sha256', 'sha512', 'md5'}

     >>> hashlib.algorithms_available
     {'md2', 'SHA256', 'SHA512', 'dsaWithSHA', 'mdc2', 'SHA224', 'MD4', 'sha256',
     'sha512', 'ripemd160', 'SHA1', 'MDC2', 'SHA', 'SHA384', 'MD2',
     'ecdsa-with-SHA1','md4', 'md5', 'sha1', 'DSA-SHA', 'sha224',
     'dsaEncryption', 'DSA', 'RIPEMD160', 'sha', 'MD5', 'sha384'}

(Suggested by Carl Chenet in bpo-7418(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=7418


File: python.info,  Node: ast<7>,  Next: os<14>,  Prev: hashlib<7>,  Up: New Improved and Deprecated Modules

1.13.9.22 ast
.............

The *note ast: 9. module has a wonderful a general-purpose tool for
safely evaluating expression strings using the Python literal syntax.
The *note ast.literal_eval(): e14. function serves as a secure
alternative to the builtin *note eval(): 4a4. function which is easily
abused.  Python 3.2 adds *note bytes: 192. and *note set: 184. literals
to the list of supported types: strings, bytes, numbers, tuples, lists,
dicts, sets, booleans, and ‘None’.

     >>> from ast import literal_eval

     >>> request = "{'req': 3, 'func': 'pow', 'args': (2, 0.5)}"
     >>> literal_eval(request)
     {'args': (2, 0.5), 'req': 3, 'func': 'pow'}

     >>> request = "os.system('do something harmful')"
     >>> literal_eval(request)
     Traceback (most recent call last):
       ...
     ValueError: malformed node or string: <_ast.Call object at 0x101739a10>

(Implemented by Benjamin Peterson and Georg Brandl.)


File: python.info,  Node: os<14>,  Next: shutil<8>,  Prev: ast<7>,  Up: New Improved and Deprecated Modules

1.13.9.23 os
............

Different operating systems use various encodings for filenames and
environment variables.  The *note os: a5. module provides two new
functions, *note fsencode(): e51. and *note fsdecode(): e50, for
encoding and decoding filenames:

     >>> import os
     >>> filename = 'Sehenswürdigkeiten'
     >>> os.fsencode(filename)
     b'Sehensw\xc3\xbcrdigkeiten'

Some operating systems allow direct access to encoded bytes in the
environment.  If so, the *note os.supports_bytes_environ: 141d. constant
will be true.

For direct access to encoded environment variables (if available), use
the new *note os.getenvb(): 141e. function or use *note os.environb:
25a. which is a bytes version of *note os.environ: 259.

(Contributed by Victor Stinner.)


File: python.info,  Node: shutil<8>,  Next: sqlite3<12>,  Prev: os<14>,  Up: New Improved and Deprecated Modules

1.13.9.24 shutil
................

The *note shutil.copytree(): c20. function has two new options:

   * 'ignore_dangling_symlinks': when ‘symlinks=False’ so that the
     function copies a file pointed to by a symlink, not the symlink
     itself.  This option will silence the error raised if the file
     doesn’t exist.

   * 'copy_function': is a callable that will be used to copy files.
     *note shutil.copy2(): c52. is used by default.

(Contributed by Tarek Ziadé.)

In addition, the *note shutil: ca. module now supports *note archiving
operations: 1420. for zipfiles, uncompressed tarfiles, gzipped tarfiles,
and bzipped tarfiles.  And there are functions for registering
additional archiving file formats (such as xz compressed tarfiles or
custom formats).

The principal functions are *note make_archive(): 6db. and *note
unpack_archive(): 697.  By default, both operate on the current
directory (which can be set by *note os.chdir(): 822.) and on any
sub-directories.  The archive filename needs to be specified with a full
pathname.  The archiving step is non-destructive (the original files are
left unchanged).

     >>> import shutil, pprint

     >>> os.chdir('mydata')  # change to the source directory
     >>> f = shutil.make_archive('/var/backup/mydata',
     ...                         'zip')      # archive the current directory
     >>> f                                   # show the name of archive
     '/var/backup/mydata.zip'
     >>> os.chdir('tmp')                     # change to an unpacking
     >>> shutil.unpack_archive('/var/backup/mydata.zip')  # recover the data

     >>> pprint.pprint(shutil.get_archive_formats())  # display known formats
     [('bztar', "bzip2'ed tar-file"),
      ('gztar', "gzip'ed tar-file"),
      ('tar', 'uncompressed tar file'),
      ('zip', 'ZIP file')]

     >>> shutil.register_archive_format(     # register a new archive format
     ...     name='xz',
     ...     function=xz.compress,           # callable archiving function
     ...     extra_args=[('level', 8)],      # arguments to the function
     ...     description='xz compression'
     ... )

(Contributed by Tarek Ziadé.)


File: python.info,  Node: sqlite3<12>,  Next: html<3>,  Prev: shutil<8>,  Up: New Improved and Deprecated Modules

1.13.9.25 sqlite3
.................

The *note sqlite3: d4. module was updated to pysqlite version 2.6.0.  It
has two new capabilities.

   * The ‘sqlite3.Connection.in_transit’ attribute is true if there is
     an active transaction for uncommitted changes.

   * The *note sqlite3.Connection.enable_load_extension(): a41. and
     *note sqlite3.Connection.load_extension(): 6e0. methods allows you
     to load SQLite extensions from «.so» files.  One well-known
     extension is the fulltext-search extension distributed with SQLite.

(Contributed by R. David Murray and Shashwat Anand; bpo-8845(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8845


File: python.info,  Node: html<3>,  Next: socket<12>,  Prev: sqlite3<12>,  Up: New Improved and Deprecated Modules

1.13.9.26 html
..............

A new *note html: 6f. module was introduced with only a single function,
*note escape(): 1210, which is used for escaping reserved characters
from HTML markup:

     >>> import html
     >>> html.escape('x > 2 && x < 7')
     'x &gt; 2 &amp;&amp; x &lt; 7'


File: python.info,  Node: socket<12>,  Next: ssl<13>,  Prev: html<3>,  Up: New Improved and Deprecated Modules

1.13.9.27 socket
................

The *note socket: d1. module has two new improvements.

   * Socket objects now have a *note detach(): 1424. method which puts
     the socket into closed state without actually closing the
     underlying file descriptor.  The latter can then be reused for
     other purposes.  (Added by Antoine Pitrou; bpo-8524(1).)

   * *note socket.create_connection(): 883. now supports the context
     management protocol to unconditionally consume *note socket.error:
     1258. exceptions and to close the socket when done.  (Contributed
     by Giampaolo Rodolà; bpo-9794(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8524

   (2) https://bugs.python.org/issue?@action=redirect&bpo=9794


File: python.info,  Node: ssl<13>,  Next: nntp,  Prev: socket<12>,  Up: New Improved and Deprecated Modules

1.13.9.28 ssl
.............

The *note ssl: d5. module added a number of features to satisfy common
requirements for secure (encrypted, authenticated) internet connections:

   * A new class, *note SSLContext: 357, serves as a container for
     persistent SSL data, such as protocol settings, certificates,
     private keys, and various other options.  It includes a *note
     wrap_socket(): 749. for creating an SSL socket from an SSL context.

   * A new function, ‘ssl.match_hostname()’, supports server identity
     verification for higher-level protocols by implementing the rules
     of HTTPS (from RFC 2818(1)) which are also suitable for other
     protocols.

   * The *note ssl.wrap_socket(): 749. constructor function now takes a
     'ciphers' argument.  The 'ciphers' string lists the allowed
     encryption algorithms using the format described in the OpenSSL
     documentation(2).

   * When linked against recent versions of OpenSSL, the *note ssl: d5.
     module now supports the Server Name Indication extension to the TLS
     protocol, allowing multiple «virtual hosts» using different
     certificates on a single IP port.  This extension is only supported
     in client mode, and is activated by passing the 'server_hostname'
     argument to *note ssl.SSLContext.wrap_socket(): 749.

   * Various options have been added to the *note ssl: d5. module, such
     as *note OP_NO_SSLv2: a3c. which disables the insecure and obsolete
     SSLv2 protocol.

   * The extension now loads all the OpenSSL ciphers and digest
     algorithms.  If some SSL certificates cannot be verified, they are
     reported as an «unknown algorithm» error.

   * The version of OpenSSL being used is now accessible using the
     module attributes *note ssl.OPENSSL_VERSION: 1426. (a string),
     *note ssl.OPENSSL_VERSION_INFO: 1427. (a 5-tuple), and *note
     ssl.OPENSSL_VERSION_NUMBER: 1428. (an integer).

(Contributed by Antoine Pitrou in bpo-8850(3), bpo-1589(4), bpo-8322(5),
bpo-5639(6), bpo-4870(7), bpo-8484(8), and bpo-8321(9).)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2818.html

   (2) https://docs.openssl.org/1.0.2/man1/ciphers/#cipher-list-format

   (3) https://bugs.python.org/issue?@action=redirect&bpo=8850

   (4) https://bugs.python.org/issue?@action=redirect&bpo=1589

   (5) https://bugs.python.org/issue?@action=redirect&bpo=8322

   (6) https://bugs.python.org/issue?@action=redirect&bpo=5639

   (7) https://bugs.python.org/issue?@action=redirect&bpo=4870

   (8) https://bugs.python.org/issue?@action=redirect&bpo=8484

   (9) https://bugs.python.org/issue?@action=redirect&bpo=8321


File: python.info,  Node: nntp,  Next: certificates,  Prev: ssl<13>,  Up: New Improved and Deprecated Modules

1.13.9.29 nntp
..............

The ‘nntplib’ module has a revamped implementation with better bytes and
text semantics as well as more practical APIs.  These improvements break
compatibility with the nntplib version in Python 3.1, which was partly
dysfunctional in itself.

Support for secure connections through both implicit (using
‘nntplib.NNTP_SSL’) and explicit (using ‘nntplib.NNTP.starttls()’) TLS
has also been added.

(Contributed by Antoine Pitrou in bpo-9360(1) and Andrew Vant in
bpo-1926(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9360

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1926


File: python.info,  Node: certificates,  Next: imaplib<5>,  Prev: nntp,  Up: New Improved and Deprecated Modules

1.13.9.30 certificates
......................

*note http.client.HTTPSConnection: d38, *note
urllib.request.HTTPSHandler: 142b. and *note urllib.request.urlopen():
307. now take optional arguments to allow for server certificate
checking against a set of Certificate Authorities, as recommended in
public uses of HTTPS.

(Added by Antoine Pitrou, bpo-9003(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9003


File: python.info,  Node: imaplib<5>,  Next: http client<4>,  Prev: certificates,  Up: New Improved and Deprecated Modules

1.13.9.31 imaplib
.................

Support for explicit TLS on standard IMAP4 connections has been added
through the new *note imaplib.IMAP4.starttls: 142d. method.

(Contributed by Lorenzo M. Catucci and Antoine Pitrou, bpo-4471(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4471


File: python.info,  Node: http client<4>,  Next: unittest<12>,  Prev: imaplib<5>,  Up: New Improved and Deprecated Modules

1.13.9.32 http.client
.....................

There were a number of small API improvements in the *note http.client:
73. module.  The old-style HTTP 0.9 simple responses are no longer
supported and the 'strict' parameter is deprecated in all classes.

The *note HTTPConnection: d37. and *note HTTPSConnection: d38. classes
now have a 'source_address' parameter for a (host, port) tuple
indicating where the HTTP connection is made from.

Support for certificate checking and HTTPS virtual hosts were added to
*note HTTPSConnection: d38.

The *note request(): ea9. method on connection objects allowed an
optional 'body' argument so that a *note file object: 13cb. could be
used to supply the content of the request.  Conveniently, the 'body'
argument now also accepts an *note iterable: 142f. object so long as it
includes an explicit ‘Content-Length’ header.  This extended interface
is much more flexible than before.

To establish an HTTPS connection through a proxy server, there is a new
*note set_tunnel(): 1430. method that sets the host and port for HTTP
Connect tunneling.

To match the behavior of *note http.server: 76, the HTTP client library
now also encodes headers with ISO-8859-1 (Latin-1) encoding.  It was
already doing that for incoming headers, so now the behavior is
consistent for both incoming and outgoing traffic.  (See work by Armin
Ronacher in bpo-10980(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10980


File: python.info,  Node: unittest<12>,  Next: random<5>,  Prev: http client<4>,  Up: New Improved and Deprecated Modules

1.13.9.33 unittest
..................

The unittest module has a number of improvements supporting test
discovery for packages, easier experimentation at the interactive
prompt, new testcase methods, improved diagnostic messages for test
failures, and better method names.

   * The command-line call ‘python -m unittest’ can now accept file
     paths instead of module names for running specific tests
     (bpo-10620(1)).  The new test discovery can find tests within
     packages, locating any test importable from the top-level
     directory.  The top-level directory can be specified with the ‘-t’
     option, a pattern for matching files with ‘-p’, and a directory to
     start discovery with ‘-s’:

          $ python -m unittest discover -s my_proj_dir -p _test.py

     (Contributed by Michael Foord.)

   * Experimentation at the interactive prompt is now easier because the
     *note unittest.TestCase: 2b3. class can now be instantiated without
     arguments:

          >>> from unittest import TestCase
          >>> TestCase().assertEqual(pow(2, 3), 8)

     (Contributed by Michael Foord.)

   * The *note unittest: 10c. module has two new methods, *note
     assertWarns(): 136c. and *note assertWarnsRegex(): 136d. to verify
     that a given warning type is triggered by the code under test:

          with self.assertWarns(DeprecationWarning):
              legacy_function('XYZ')

     (Contributed by Antoine Pitrou, bpo-9754(2).)

     Another new method, *note assertCountEqual(): 1432. is used to
     compare two iterables to determine if their element counts are
     equal (whether the same elements are present with the same number
     of occurrences regardless of order):

          def test_anagram(self):
              self.assertCountEqual('algorithm', 'logarithm')

     (Contributed by Raymond Hettinger.)

   * A principal feature of the unittest module is an effort to produce
     meaningful diagnostics when a test fails.  When possible, the
     failure is recorded along with a diff of the output.  This is
     especially helpful for analyzing log files of failed test runs.
     However, since diffs can sometime be voluminous, there is a new
     *note maxDiff: 1433. attribute that sets maximum length of diffs
     displayed.

   * In addition, the method names in the module have undergone a number
     of clean-ups.

     For example, *note assertRegex(): 752. is the new name for
     ‘assertRegexpMatches()’ which was misnamed because the test uses
     *note re.search(): 1434, not *note re.match(): 1435.  Other methods
     using regular expressions are now named using short form «Regex» in
     preference to «Regexp» – this matches the names used in other
     unittest implementations, matches Python’s old name for the *note
     re: be. module, and it has unambiguous camel-casing.

     (Contributed by Raymond Hettinger and implemented by Ezio Melotti.)

   * To improve consistency, some long-standing method aliases are being
     deprecated in favor of the preferred names:

          Old Name                            Preferred Name
                                              
          -----------------------------------------------------------------------
                                              
          ‘assert_()’                         *note assertTrue(): 74b.
                                              
                                              
          ‘assertEquals()’                    *note assertEqual(): 74d.
                                              
                                              
          ‘assertNotEquals()’                 *note assertNotEqual(): 74e.
                                              
                                              
          ‘assertAlmostEquals()’              *note assertAlmostEqual(): 74f.
                                              
                                              
          ‘assertNotAlmostEquals()’           *note assertNotAlmostEqual(): 750.
                                              

     Likewise, the ‘TestCase.fail*’ methods deprecated in Python 3.1 are
     expected to be removed in Python 3.3.

     (Contributed by Ezio Melotti; bpo-9424(3).)

   * The ‘assertDictContainsSubset()’ method was deprecated because it
     was misimplemented with the arguments in the wrong order.  This
     created hard-to-debug optical illusions where tests like
     ‘TestCase().assertDictContainsSubset({'a':1, 'b':2}, {'a':1})’
     would fail.

     (Contributed by Raymond Hettinger.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10620

   (2) https://bugs.python.org/issue?@action=redirect&bpo=9754

   (3) https://bugs.python.org/issue?@action=redirect&bpo=9424


File: python.info,  Node: random<5>,  Next: poplib<4>,  Prev: unittest<12>,  Up: New Improved and Deprecated Modules

1.13.9.34 random
................

The integer methods in the *note random: bd. module now do a better job
of producing uniform distributions.  Previously, they computed
selections with ‘int(n*random())’ which had a slight bias whenever 'n'
was not a power of two.  Now, multiple selections are made from a range
up to the next power of two and a selection is kept only when it falls
within the range ‘0 <= x < n’.  The functions and methods affected are
*note randrange(): a6d, *note randint(): 1437, *note choice(): 1438,
*note shuffle(): 94f. and *note sample(): 94e.

(Contributed by Raymond Hettinger; bpo-9025(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9025


File: python.info,  Node: poplib<4>,  Next: asyncore<2>,  Prev: random<5>,  Up: New Improved and Deprecated Modules

1.13.9.35 poplib
................

*note POP3_SSL: b20. class now accepts a 'context' parameter, which is a
*note ssl.SSLContext: 357. object allowing bundling SSL configuration
options, certificates and private keys into a single (potentially
long-lived) structure.

(Contributed by Giampaolo Rodolà; bpo-8807(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8807


File: python.info,  Node: asyncore<2>,  Next: tempfile<5>,  Prev: poplib<4>,  Up: New Improved and Deprecated Modules

1.13.9.36 asyncore
..................

‘asyncore.dispatcher’ now provides a ‘handle_accepted()’ method
returning a ‘(sock, addr)’ pair which is called when a connection has
actually been established with a new remote endpoint.  This is supposed
to be used as a replacement for old ‘handle_accept()’ and avoids the
user to call ‘accept()’ directly.

(Contributed by Giampaolo Rodolà; bpo-6706(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6706


File: python.info,  Node: tempfile<5>,  Next: inspect<11>,  Prev: asyncore<2>,  Up: New Improved and Deprecated Modules

1.13.9.37 tempfile
..................

The *note tempfile: e6. module has a new context manager, *note
TemporaryDirectory: 143c. which provides easy deterministic cleanup of
temporary directories:

     with tempfile.TemporaryDirectory() as tmpdirname:
         print('created temporary dir:', tmpdirname)

(Contributed by Neil Schemenauer and Nick Coghlan; bpo-5178(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5178


File: python.info,  Node: inspect<11>,  Next: pydoc<7>,  Prev: tempfile<5>,  Up: New Improved and Deprecated Modules

1.13.9.38 inspect
.................

   * The *note inspect: 82. module has a new function *note
     getgeneratorstate(): 143e. to easily identify the current state of
     a generator-iterator:

          >>> from inspect import getgeneratorstate
          >>> def gen():
          ...     yield 'demo'
          ...
          >>> g = gen()
          >>> getgeneratorstate(g)
          'GEN_CREATED'
          >>> next(g)
          'demo'
          >>> getgeneratorstate(g)
          'GEN_SUSPENDED'
          >>> next(g, None)
          >>> getgeneratorstate(g)
          'GEN_CLOSED'

     (Contributed by Rodolpho Eckhardt and Nick Coghlan, bpo-10220(1).)

   * To support lookups without the possibility of activating a dynamic
     attribute, the *note inspect: 82. module has a new function, *note
     getattr_static(): 6bd.  Unlike *note hasattr(): 6fa, this is a true
     read-only search, guaranteed not to change state while it is
     searching:

          >>> class A:
          ...     @property
          ...     def f(self):
          ...         print('Running')
          ...         return 10
          ...
          >>> a = A()
          >>> getattr(a, 'f')
          Running
          10
          >>> inspect.getattr_static(a, 'f')
          <property object at 0x1022bd788>

     (Contributed by Michael Foord.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10220


File: python.info,  Node: pydoc<7>,  Next: dis<6>,  Prev: inspect<11>,  Up: New Improved and Deprecated Modules

1.13.9.39 pydoc
...............

The *note pydoc: ba. module now provides a much-improved web server
interface, as well as a new command-line option ‘-b’ to automatically
open a browser window to display that server:

     $ pydoc3.2 -b

(Contributed by Ron Adam; bpo-2001(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=2001


File: python.info,  Node: dis<6>,  Next: dbm<7>,  Prev: pydoc<7>,  Up: New Improved and Deprecated Modules

1.13.9.40 dis
.............

The *note dis: 3c. module gained two new functions for inspecting code,
*note code_info(): 1441. and *note show_code(): 1130.  Both provide
detailed code object information for the supplied function, method,
source code string or code object.  The former returns a string and the
latter prints it:

     >>> import dis, random
     >>> dis.show_code(random.choice)
     Name:              choice
     Filename:          /Library/Frameworks/Python.framework/Versions/3.2/lib/python3.2/random.py
     Argument count:    2
     Kw-only arguments: 0
     Number of locals:  3
     Stack size:        11
     Flags:             OPTIMIZED, NEWLOCALS, NOFREE
     Constants:
        0: 'Choose a random element from a non-empty sequence.'
        1: 'Cannot choose from an empty sequence'
     Names:
        0: _randbelow
        1: len
        2: ValueError
        3: IndexError
     Variable names:
        0: self
        1: seq
        2: i

In addition, the *note dis(): 205. function now accepts string arguments
so that the common idiom ‘dis(compile(s, '', 'eval'))’ can be shortened
to ‘dis(s)’:

     >>> dis('3*x+1 if x%2==1 else x//2')
       1           0 LOAD_NAME                0 (x)
                   3 LOAD_CONST               0 (2)
                   6 BINARY_MODULO
                   7 LOAD_CONST               1 (1)
                  10 COMPARE_OP               2 (==)
                  13 POP_JUMP_IF_FALSE       28
                  16 LOAD_CONST               2 (3)
                  19 LOAD_NAME                0 (x)
                  22 BINARY_MULTIPLY
                  23 LOAD_CONST               1 (1)
                  26 BINARY_ADD
                  27 RETURN_VALUE
             >>   28 LOAD_NAME                0 (x)
                  31 LOAD_CONST               0 (2)
                  34 BINARY_FLOOR_DIVIDE
                  35 RETURN_VALUE

Taken together, these improvements make it easier to explore how CPython
is implemented and to see for yourself what the language syntax does
under-the-hood.

(Contributed by Nick Coghlan in bpo-9147(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9147


File: python.info,  Node: dbm<7>,  Next: ctypes<4>,  Prev: dis<6>,  Up: New Improved and Deprecated Modules

1.13.9.41 dbm
.............

All database modules now support the ‘get()’ and ‘setdefault()’ methods.

(Suggested by Ray Allen in bpo-9523(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9523


File: python.info,  Node: ctypes<4>,  Next: site<4>,  Prev: dbm<7>,  Up: New Improved and Deprecated Modules

1.13.9.42 ctypes
................

A new type, *note ctypes.c_ssize_t: 1444. represents the C ‘ssize_t’
datatype.


File: python.info,  Node: site<4>,  Next: sysconfig<4>,  Prev: ctypes<4>,  Up: New Improved and Deprecated Modules

1.13.9.43 site
..............

The *note site: cc. module has three new functions useful for reporting
on the details of a given Python installation.

   * *note getsitepackages(): 1446. lists all global site-packages
     directories.

   * *note getuserbase(): 1447. reports on the user’s base directory
     where data can be stored.

   * *note getusersitepackages(): 1448. reveals the user-specific
     site-packages directory path.

     >>> import site
     >>> site.getsitepackages()
     ['/Library/Frameworks/Python.framework/Versions/3.2/lib/python3.2/site-packages',
      '/Library/Frameworks/Python.framework/Versions/3.2/lib/site-python',
      '/Library/Python/3.2/site-packages']
     >>> site.getuserbase()
     '/Users/raymondhettinger/Library/Python/3.2'
     >>> site.getusersitepackages()
     '/Users/raymondhettinger/Library/Python/3.2/lib/python/site-packages'

Conveniently, some of site’s functionality is accessible directly from
the command-line:

     $ python -m site --user-base
     /Users/raymondhettinger/.local
     $ python -m site --user-site
     /Users/raymondhettinger/.local/lib/python3.2/site-packages

(Contributed by Tarek Ziadé in bpo-6693(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6693


File: python.info,  Node: sysconfig<4>,  Next: pdb<10>,  Prev: site<4>,  Up: New Improved and Deprecated Modules

1.13.9.44 sysconfig
...................

The new *note sysconfig: e1. module makes it straightforward to discover
installation paths and configuration variables that vary across
platforms and installations.

The module offers access simple access functions for platform and
version information:

   * *note get_platform(): 144a. returning values like 'linux-i586' or
     'macosx-10.6-ppc'.

   * *note get_python_version(): 144b. returns a Python version string
     such as «3.2».

It also provides access to the paths and variables corresponding to one
of seven named schemes used by ‘distutils’.  Those include
'posix_prefix', 'posix_home', 'posix_user', 'nt', 'nt_user', 'os2',
'os2_home':

   * *note get_paths(): 340. makes a dictionary containing installation
     paths for the current installation scheme.

   * *note get_config_vars(): 298. returns a dictionary of platform
     specific variables.

There is also a convenient command-line interface:

     C:\Python32>python -m sysconfig
     Platform: "win32"
     Python version: "3.2"
     Current installation scheme: "nt"

     Paths:
             data = "C:\Python32"
             include = "C:\Python32\Include"
             platinclude = "C:\Python32\Include"
             platlib = "C:\Python32\Lib\site-packages"
             platstdlib = "C:\Python32\Lib"
             purelib = "C:\Python32\Lib\site-packages"
             scripts = "C:\Python32\Scripts"
             stdlib = "C:\Python32\Lib"

     Variables:
             BINDIR = "C:\Python32"
             BINLIBDEST = "C:\Python32\Lib"
             EXE = ".exe"
             INCLUDEPY = "C:\Python32\Include"
             LIBDEST = "C:\Python32\Lib"
             SO = ".pyd"
             VERSION = "32"
             abiflags = ""
             base = "C:\Python32"
             exec_prefix = "C:\Python32"
             platbase = "C:\Python32"
             prefix = "C:\Python32"
             projectbase = "C:\Python32"
             py_version = "3.2"
             py_version_nodot = "32"
             py_version_short = "3.2"
             srcdir = "C:\Python32"
             userbase = "C:\Documents and Settings\Raymond\Application Data\Python"

(Moved out of Distutils by Tarek Ziadé.)


File: python.info,  Node: pdb<10>,  Next: configparser<6>,  Prev: sysconfig<4>,  Up: New Improved and Deprecated Modules

1.13.9.45 pdb
.............

The *note pdb: aa. debugger module gained a number of usability
improvements:

   * ‘pdb.py’ now has a ‘-c’ option that executes commands as given in a
     ‘.pdbrc’ script file.

   * A ‘.pdbrc’ script file can contain ‘continue’ and ‘next’ commands
     that continue debugging.

   * The *note Pdb: 273. class constructor now accepts a 'nosigint'
     argument.

   * New commands: ‘l(list)’, ‘ll(long list)’ and ‘source’ for listing
     source code.

   * New commands: ‘display’ and ‘undisplay’ for showing or hiding the
     value of an expression if it has changed.

   * New command: ‘interact’ for starting an interactive interpreter
     containing the global and local names found in the current scope.

   * Breakpoints can be cleared by breakpoint number.

(Contributed by Georg Brandl, Antonio Cuni and Ilya Sandler.)


File: python.info,  Node: configparser<6>,  Next: urllib parse<6>,  Prev: pdb<10>,  Up: New Improved and Deprecated Modules

1.13.9.46 configparser
......................

The *note configparser: 26. module was modified to improve usability and
predictability of the default parser and its supported INI syntax.  The
old ‘ConfigParser’ class was removed in favor of ‘SafeConfigParser’
which has in turn been renamed to *note ConfigParser: 4df.  Support for
inline comments is now turned off by default and section or option
duplicates are not allowed in a single configuration source.

Config parsers gained a new API based on the mapping protocol:

     >>> parser = ConfigParser()
     >>> parser.read_string("""
     ... [DEFAULT]
     ... location = upper left
     ... visible = yes
     ... editable = no
     ... color = blue
     ...
     ... [main]
     ... title = Main Menu
     ... color = green
     ...
     ... [options]
     ... title = Options
     ... """)
     >>> parser['main']['color']
     'green'
     >>> parser['main']['editable']
     'no'
     >>> section = parser['options']
     >>> section['title']
     'Options'
     >>> section['title'] = 'Options (editable: %(editable)s)'
     >>> section['title']
     'Options (editable: no)'

The new API is implemented on top of the classical API, so custom parser
subclasses should be able to use it without modifications.

The INI file structure accepted by config parsers can now be customized.
Users can specify alternative option/value delimiters and comment
prefixes, change the name of the 'DEFAULT' section or switch the
interpolation syntax.

There is support for pluggable interpolation including an additional
interpolation handler *note ExtendedInterpolation: 92e.:

     >>> parser = ConfigParser(interpolation=ExtendedInterpolation())
     >>> parser.read_dict({'buildout': {'directory': '/home/ambv/zope9'},
     ...                   'custom': {'prefix': '/usr/local'}})
     >>> parser.read_string("""
     ... [buildout]
     ... parts =
     ...   zope9
     ...   instance
     ... find-links =
     ...   ${buildout:directory}/downloads/dist
     ...
     ... [zope9]
     ... recipe = plone.recipe.zope9install
     ... location = /opt/zope
     ...
     ... [instance]
     ... recipe = plone.recipe.zope9instance
     ... zope9-location = ${zope9:location}
     ... zope-conf = ${custom:prefix}/etc/zope.conf
     ... """)
     >>> parser['buildout']['find-links']
     '\n/home/ambv/zope9/downloads/dist'
     >>> parser['instance']['zope-conf']
     '/usr/local/etc/zope.conf'
     >>> instance = parser['instance']
     >>> instance['zope-conf']
     '/usr/local/etc/zope.conf'
     >>> instance['zope9-location']
     '/opt/zope'

A number of smaller features were also introduced, like support for
specifying encoding in read operations, specifying fallback values for
get-functions, or reading directly from dictionaries and strings.

(All changes contributed by Łukasz Langa.)


File: python.info,  Node: urllib parse<6>,  Next: mailbox,  Prev: configparser<6>,  Up: New Improved and Deprecated Modules

1.13.9.47 urllib.parse
......................

A number of usability improvements were made for the *note urllib.parse:
110. module.

The *note urlparse(): 362. function now supports IPv6(1) addresses as
described in RFC 2732(2):

     >>> import urllib.parse
     >>> urllib.parse.urlparse('http://[dead:beef:cafe:5417:affe:8FA3:deaf:feed]/foo/')
     ParseResult(scheme='http',
                 netloc='[dead:beef:cafe:5417:affe:8FA3:deaf:feed]',
                 path='/foo/',
                 params='',
                 query='',
                 fragment='')

The *note urldefrag(): 144f. function now returns a *note named tuple:
85f.:

     >>> r = urllib.parse.urldefrag('http://python.org/about/#target')
     >>> r
     DefragResult(url='http://python.org/about/', fragment='target')
     >>> r[0]
     'http://python.org/about/'
     >>> r.fragment
     'target'

And, the *note urlencode(): 1097. function is now much more flexible,
accepting either a string or bytes type for the 'query' argument.  If it
is a string, then the 'safe', 'encoding', and 'error' parameters are
sent to *note quote_plus(): 1450. for encoding:

     >>> urllib.parse.urlencode([
     ...      ('type', 'telenovela'),
     ...      ('name', '¿Dónde Está Elisa?')],
     ...      encoding='latin-1')
     'type=telenovela&name=%BFD%F3nde+Est%E1+Elisa%3F'

As detailed in *note Parsing ASCII Encoded Bytes: 1451, all the *note
urllib.parse: 110. functions now accept ASCII-encoded byte strings as
input, so long as they are not mixed with regular strings.  If
ASCII-encoded byte strings are given as parameters, the return types
will also be an ASCII-encoded byte strings:

     >>> urllib.parse.urlparse(b'http://www.python.org:80/about/')
     ParseResultBytes(scheme=b'http', netloc=b'www.python.org:80',
                      path=b'/about/', params=b'', query=b'', fragment=b'')

(Work by Nick Coghlan, Dan Mahn, and Senthil Kumaran in bpo-2987(3),
bpo-5468(4), and bpo-9873(5).)

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/IPv6

   (2) https://datatracker.ietf.org/doc/html/rfc2732.html

   (3) https://bugs.python.org/issue?@action=redirect&bpo=2987

   (4) https://bugs.python.org/issue?@action=redirect&bpo=5468

   (5) https://bugs.python.org/issue?@action=redirect&bpo=9873


File: python.info,  Node: mailbox,  Next: turtledemo,  Prev: urllib parse<6>,  Up: New Improved and Deprecated Modules

1.13.9.48 mailbox
.................

Thanks to a concerted effort by R. David Murray, the *note mailbox: 8f.
module has been fixed for Python 3.2.  The challenge was that mailbox
had been originally designed with a text interface, but email messages
are best represented with *note bytes: 192. because various parts of a
message may have different encodings.

The solution harnessed the *note email: 3f. package’s binary support for
parsing arbitrary email messages.  In addition, the solution required a
number of API changes.

As expected, the *note add(): 1453. method for *note mailbox.Mailbox:
1454. objects now accepts binary input.

*note StringIO: 112b. and text file input are deprecated.  Also, string
input will fail early if non-ASCII characters are used.  Previously it
would fail when the email was processed in a later step.

There is also support for binary output.  The *note get_file(): 1455.
method now returns a file in the binary mode (where it used to
incorrectly set the file to text-mode).  There is also a new *note
get_bytes(): 1456. method that returns a *note bytes: 192.
representation of a message corresponding to a given 'key'.

It is still possible to get non-binary output using the old API’s *note
get_string(): 1457. method, but that approach is not very useful.
Instead, it is best to extract messages from a *note Message: 1458.
object or to load them from binary input.

(Contributed by R. David Murray, with efforts from Steffen Daode
Nurpmeso and an initial patch by Victor Stinner in bpo-9124(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=9124


File: python.info,  Node: turtledemo,  Prev: mailbox,  Up: New Improved and Deprecated Modules

1.13.9.49 turtledemo
....................

The demonstration code for the *note turtle: 107. module was moved from
the 'Demo' directory to main library.  It includes over a dozen sample
scripts with lively displays.  Being on *note sys.path: 3e4, it can now
be run directly from the command-line:

     $ python -m turtledemo

(Moved from the Demo directory by Alexander Belopolsky in bpo-10199(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10199


File: python.info,  Node: Multi-threading,  Next: Optimizations<11>,  Prev: New Improved and Deprecated Modules,  Up: What’s New In Python 3 2

1.13.10 Multi-threading
-----------------------

   * The mechanism for serializing execution of concurrently running
     Python threads (generally known as the *note GIL: 164. or Global
     Interpreter Lock) has been rewritten.  Among the objectives were
     more predictable switching intervals and reduced overhead due to
     lock contention and the number of ensuing system calls.  The notion
     of a «check interval» to allow thread switches has been abandoned
     and replaced by an absolute duration expressed in seconds.  This
     parameter is tunable through *note sys.setswitchinterval(): b46.
     It currently defaults to 5 milliseconds.

     Additional details about the implementation can be read from a
     python-dev mailing-list message(1) (however, «priority requests» as
     exposed in this message have not been kept for inclusion).

     (Contributed by Antoine Pitrou.)

   * Regular and recursive locks now accept an optional 'timeout'
     argument to their *note acquire(): 8a8. method.  (Contributed by
     Antoine Pitrou; bpo-7316(2).)

   * Similarly, *note threading.Semaphore.acquire(): 145b. also gained a
     'timeout' argument.  (Contributed by Torsten Landschoff;
     bpo-850728(3).)

   * Regular and recursive lock acquisitions can now be interrupted by
     signals on platforms using Pthreads.  This means that Python
     programs that deadlock while acquiring locks can be successfully
     killed by repeatedly sending SIGINT to the process (by pressing
     ‘Ctrl’+‘C’ in most shells).  (Contributed by Reid Kleckner;
     bpo-8844(4).)

   ---------- Footnotes ----------

   (1) 
https://mail.python.org/pipermail/python-dev/2009-October/093321.html

   (2) https://bugs.python.org/issue?@action=redirect&bpo=7316

   (3) https://bugs.python.org/issue?@action=redirect&bpo=850728

   (4) https://bugs.python.org/issue?@action=redirect&bpo=8844


File: python.info,  Node: Optimizations<11>,  Next: Unicode,  Prev: Multi-threading,  Up: What’s New In Python 3 2

1.13.11 Optimizations
---------------------

A number of small performance enhancements have been added:

   * Python’s peephole optimizer now recognizes patterns such ‘x in {1,
     2, 3}’ as being a test for membership in a set of constants.  The
     optimizer recasts the *note set: 184. as a *note frozenset: 7f3.
     and stores the pre-built constant.

     Now that the speed penalty is gone, it is practical to start
     writing membership tests using set-notation.  This style is both
     semantically clear and operationally fast:

          extension = name.rpartition('.')[2]
          if extension in {'xml', 'html', 'xhtml', 'css'}:
              handle(name)

     (Patch and additional tests contributed by Dave Malcolm;
     bpo-6690(1)).

   * Serializing and unserializing data using the *note pickle: ab.
     module is now several times faster.

     (Contributed by Alexandre Vassalotti, Antoine Pitrou and the
     Unladen Swallow team in bpo-9410(2) and bpo-3873(3).)

   * The Timsort algorithm(4) used in *note list.sort(): dca. and *note
     sorted(): dc9. now runs faster and uses less memory when called
     with a *note key function: 1008.  Previously, every element of a
     list was wrapped with a temporary object that remembered the key
     value associated with each element.  Now, two arrays of keys and
     values are sorted in parallel.  This saves the memory consumed by
     the sort wrappers, and it saves time lost to delegating
     comparisons.

     (Patch by Daniel Stutzbach in bpo-9915(5).)

   * JSON decoding performance is improved and memory consumption is
     reduced whenever the same string is repeated for multiple keys.
     Also, JSON encoding now uses the C speedups when the ‘sort_keys’
     argument is true.

     (Contributed by Antoine Pitrou in bpo-7451(6) and by Raymond
     Hettinger and Antoine Pitrou in bpo-10314(7).)

   * Recursive locks (created with the *note threading.RLock(): 32e.
     API) now benefit from a C implementation which makes them as fast
     as regular locks, and between 10x and 15x faster than their
     previous pure Python implementation.

     (Contributed by Antoine Pitrou; bpo-3001(8).)

   * The fast-search algorithm in stringlib is now used by the *note
     split(): 10ac, *note rsplit(): 145d, *note splitlines(): 145e. and
     *note replace(): 4b9. methods on *note bytes: 192, *note bytearray:
     344. and *note str: 169. objects.  Likewise, the algorithm is also
     used by *note rfind(): 10ab, *note rindex(): 145f, *note rsplit():
     145d. and *note rpartition(): 1460.

     (Patch by Florent Xicluna in bpo-7622(9) and bpo-7462(10).)

   * Integer to string conversions now work two «digits» at a time,
     reducing the number of division and modulo operations.

     (bpo-6713(11) by Gawain Bolton, Mark Dickinson, and Victor
     Stinner.)

There were several other minor optimizations.  Set differencing now runs
faster when one operand is much larger than the other (patch by Andress
Bennetts in bpo-8685(12)).  The ‘array.repeat()’ method has a faster
implementation (bpo-1569291(13) by Alexander Belopolsky).  The *note
BaseHTTPRequestHandler: 12d3. has more efficient buffering (bpo-3709(14)
by Andrew Schaaf).  The *note operator.attrgetter(): 1035. function has
been sped-up (bpo-10160(15) by Christos Georgiou).  And *note
ConfigParser: 4df. loads multi-line arguments a bit faster (bpo-7113(16)
by Łukasz Langa).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6690

   (2) https://bugs.python.org/issue?@action=redirect&bpo=9410

   (3) https://bugs.python.org/issue?@action=redirect&bpo=3873

   (4) https://en.wikipedia.org/wiki/Timsort

   (5) https://bugs.python.org/issue?@action=redirect&bpo=9915

   (6) https://bugs.python.org/issue?@action=redirect&bpo=7451

   (7) https://bugs.python.org/issue?@action=redirect&bpo=10314

   (8) https://bugs.python.org/issue?@action=redirect&bpo=3001

   (9) https://bugs.python.org/issue?@action=redirect&bpo=7622

   (10) https://bugs.python.org/issue?@action=redirect&bpo=7462

   (11) https://bugs.python.org/issue?@action=redirect&bpo=6713

   (12) https://bugs.python.org/issue?@action=redirect&bpo=8685

   (13) https://bugs.python.org/issue?@action=redirect&bpo=1569291

   (14) https://bugs.python.org/issue?@action=redirect&bpo=3709

   (15) https://bugs.python.org/issue?@action=redirect&bpo=10160

   (16) https://bugs.python.org/issue?@action=redirect&bpo=7113


File: python.info,  Node: Unicode,  Next: Codecs,  Prev: Optimizations<11>,  Up: What’s New In Python 3 2

1.13.12 Unicode
---------------

Python has been updated to Unicode 6.0.0(1).  The update to the standard
adds over 2,000 new characters including emoji(2) symbols which are
important for mobile phones.

In addition, the updated standard has altered the character properties
for two Kannada characters (U+0CF1, U+0CF2) and one New Tai Lue numeric
character (U+19DA), making the former eligible for use in identifiers
while disqualifying the latter.  For more information, see Unicode
Character Database Changes(3).

   ---------- Footnotes ----------

   (1) https://unicode.org/versions/Unicode6.0.0/

   (2) https://en.wikipedia.org/wiki/Emoji

   (3) https://www.unicode.org/versions/Unicode6.0.0/#Database_Changes


File: python.info,  Node: Codecs,  Next: Documentation,  Prev: Unicode,  Up: What’s New In Python 3 2

1.13.13 Codecs
--------------

Support was added for 'cp720' Arabic DOS encoding (bpo-1616979(1)).

MBCS encoding no longer ignores the error handler argument.  In the
default strict mode, it raises an *note UnicodeDecodeError: c0a. when it
encounters an undecodable byte sequence and an *note UnicodeEncodeError:
888. for an unencodable character.

The MBCS codec supports ‘'strict'’ and ‘'ignore'’ error handlers for
decoding, and ‘'strict'’ and ‘'replace'’ for encoding.

To emulate Python3.1 MBCS encoding, select the ‘'ignore'’ handler for
decoding and the ‘'replace'’ handler for encoding.

On Mac OS X, Python decodes command line arguments with ‘'utf-8'’ rather
than the locale encoding.

By default, *note tarfile: e4. uses ‘'utf-8'’ encoding on Windows
(instead of ‘'mbcs'’) and the ‘'surrogateescape'’ error handler on all
operating systems.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1616979


File: python.info,  Node: Documentation,  Next: IDLE,  Prev: Codecs,  Up: What’s New In Python 3 2

1.13.14 Documentation
---------------------

The documentation continues to be improved.

   * A table of quick links has been added to the top of lengthy
     sections such as *note Funzioni Incorporate: 1464.  In the case of
     *note itertools: 85, the links are accompanied by tables of
     cheatsheet-style summaries to provide an overview and memory jog
     without having to read all of the docs.

   * In some cases, the pure Python source code can be a helpful adjunct
     to the documentation, so now many modules now feature quick links
     to the latest version of the source code.  For example, the *note
     functools: 63. module documentation has a quick link at the top
     labeled:

          'Source code' Lib/functools.py(1).

     (Contributed by Raymond Hettinger; see rationale(2).)

   * The docs now contain more examples and recipes.  In particular,
     *note re: be. module has an extensive section, *note Regular
     Expression Examples: 1465.  Likewise, the *note itertools: 85.
     module continues to be updated with new *note Itertools Recipes:
     1466.

   * The *note datetime: 34. module now has an auxiliary implementation
     in pure Python.  No functionality was changed.  This just provides
     an easier-to-read alternate implementation.

     (Contributed by Alexander Belopolsky in bpo-9528(3).)

   * The unmaintained ‘Demo’ directory has been removed.  Some demos
     were integrated into the documentation, some were moved to the
     ‘Tools/demo’ directory, and others were removed altogether.

     (Contributed by Georg Brandl in bpo-7962(4).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/functools.py

   (2) 
https://rhettinger.wordpress.com/2011/01/28/open-your-source-more/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=9528

   (4) https://bugs.python.org/issue?@action=redirect&bpo=7962


File: python.info,  Node: IDLE,  Next: Code Repository,  Prev: Documentation,  Up: What’s New In Python 3 2

1.13.15 IDLE
------------

   * The format menu now has an option to clean source files by
     stripping trailing whitespace.

     (Contributed by Raymond Hettinger; bpo-5150(1).)

   * IDLE on Mac OS X now works with both Carbon AquaTk and Cocoa
     AquaTk.

     (Contributed by Kevin Walzer, Ned Deily, and Ronald Oussoren;
     bpo-6075(2).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5150

   (2) https://bugs.python.org/issue?@action=redirect&bpo=6075


File: python.info,  Node: Code Repository,  Next: Build and C API Changes<5>,  Prev: IDLE,  Up: What’s New In Python 3 2

1.13.16 Code Repository
-----------------------

In addition to the existing Subversion code repository at
‘https://svn.python.org’ there is now a Mercurial(1) repository at
‘https://hg.python.org/’.

After the 3.2 release, there are plans to switch to Mercurial as the
primary repository.  This distributed version control system should make
it easier for members of the community to create and share external
changesets.  See PEP 385(2) for details.

To learn to use the new version control system, see the Quick Start(3)
or the Guide to Mercurial Workflows(4).

   ---------- Footnotes ----------

   (1) https://www.mercurial-scm.org/

   (2) https://peps.python.org/pep-0385/

   (3) https://www.mercurial-scm.org/wiki/QuickStart

   (4) https://www.mercurial-scm.org/guide


File: python.info,  Node: Build and C API Changes<5>,  Next: Porting to Python 3 2,  Prev: Code Repository,  Up: What’s New In Python 3 2

1.13.17 Build and C API Changes
-------------------------------

Changes to Python’s build process and to the C API include:

   * The 'idle', 'pydoc' and '2to3' scripts are now installed with a
     version-specific suffix on ‘make altinstall’ (bpo-10679(1)).

   * The C functions that access the Unicode Database now accept and
     return characters from the full Unicode range, even on narrow
     unicode builds (Py_UNICODE_TOLOWER, Py_UNICODE_ISDECIMAL, and
     others).  A visible difference in Python is that *note
     unicodedata.numeric(): 146a. now returns the correct value for
     large code points, and *note repr(): 1c1. may consider more
     characters as printable.

     (Reported by Bupjoe Lee and fixed by Amaury Forgeot D’Arc;
     bpo-5127(2).)

   * Computed gotos are now enabled by default on supported compilers
     (which are detected by the configure script).  They can still be
     disabled selectively by specifying ‘--without-computed-gotos’.

     (Contributed by Antoine Pitrou; bpo-9203(3).)

   * The option ‘--with-wctype-functions’ was removed.  The built-in
     unicode database is now used for all functions.

     (Contributed by Amaury Forgeot D’Arc; bpo-9210(4).)

   * Hash values are now values of a new type, *note Py_hash_t: 146b,
     which is defined to be the same size as a pointer.  Previously they
     were of type long, which on some 64-bit operating systems is still
     only 32 bits long.  As a result of this fix, *note set: 184. and
     *note dict: 183. can now hold more than ‘2**32’ entries on builds
     with 64-bit pointers (previously, they could grow to that size but
     their performance degraded catastrophically).

     (Suggested by Raymond Hettinger and implemented by Benjamin
     Peterson; bpo-9778(5).)

   * A new macro ‘Py_VA_COPY’ copies the state of the variable argument
     list.  It is equivalent to C99 'va_copy' but available on all
     Python platforms (bpo-2443(6)).

   * A new C API function ‘PySys_SetArgvEx()’ allows an embedded
     interpreter to set *note sys.argv: 146c. without also modifying
     *note sys.path: 3e4. (bpo-5753(7)).

   * ‘PyEval_CallObject()’ is now only available in macro form.  The
     function declaration, which was kept for backwards compatibility
     reasons, is now removed – the macro was introduced in 1997
     (bpo-8276(8)).

   * There is a new function *note PyLong_AsLongLongAndOverflow(): 146d.
     which is analogous to *note PyLong_AsLongAndOverflow(): 146e.  They
     both serve to convert Python *note int: 19b. into a native
     fixed-width type while providing detection of cases where the
     conversion won’t fit (bpo-7767(9)).

   * The *note PyUnicode_CompareWithASCIIString(): 146f. function now
     returns 'not equal' if the Python string is 'NUL' terminated.

   * There is a new function *note PyErr_NewExceptionWithDoc(): 1470.
     that is like *note PyErr_NewException(): 1471. but allows a
     docstring to be specified.  This lets C exceptions have the same
     self-documenting capabilities as their pure Python counterparts
     (bpo-7033(10)).

   * When compiled with the ‘--with-valgrind’ option, the pymalloc
     allocator will be automatically disabled when running under
     Valgrind.  This gives improved memory leak detection when running
     under Valgrind, while taking advantage of pymalloc at other times
     (bpo-2422(11)).

   * Removed the ‘O?’ format from the 'PyArg_Parse' functions.  The
     format is no longer used and it had never been documented
     (bpo-8837(12)).

There were a number of other small changes to the C-API. See the
Misc/NEWS(13) file for a complete list.

Also, there were a number of updates to the Mac OS X build, see
Mac/BuildScript/README.txt(14) for details.  For users running a
32/64-bit build, there is a known problem with the default Tcl/Tk on Mac
OS X 10.6.  Accordingly, we recommend installing an updated alternative
such as ActiveState Tcl/Tk 8.5.9(15).  See
‘https://www.python.org/download/mac/tcltk/’ for additional details.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10679

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5127

   (3) https://bugs.python.org/issue?@action=redirect&bpo=9203

   (4) https://bugs.python.org/issue?@action=redirect&bpo=9210

   (5) https://bugs.python.org/issue?@action=redirect&bpo=9778

   (6) https://bugs.python.org/issue?@action=redirect&bpo=2443

   (7) https://bugs.python.org/issue?@action=redirect&bpo=5753

   (8) https://bugs.python.org/issue?@action=redirect&bpo=8276

   (9) https://bugs.python.org/issue?@action=redirect&bpo=7767

   (10) https://bugs.python.org/issue?@action=redirect&bpo=7033

   (11) https://bugs.python.org/issue?@action=redirect&bpo=2422

   (12) https://bugs.python.org/issue?@action=redirect&bpo=8837

   (13) https://github.com/python/cpython/blob/v3.2.6/Misc/NEWS

   (14) 
https://github.com/python/cpython/blob/v3.2.6/Mac/BuildScript/README.txt

   (15) 
https://web.archive.org/web/20101208191259/https://www.activestate.com/activetcl/downloads


File: python.info,  Node: Porting to Python 3 2,  Prev: Build and C API Changes<5>,  Up: What’s New In Python 3 2

1.13.18 Porting to Python 3.2
-----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code:

   * The *note configparser: 26. module has a number of clean-ups.  The
     major change is to replace the old ‘ConfigParser’ class with
     long-standing preferred alternative ‘SafeConfigParser’.  In
     addition there are a number of smaller incompatibilities:

        * The interpolation syntax is now validated on *note get():
          1473. and *note set(): 1474. operations.  In the default
          interpolation scheme, only two tokens with percent signs are
          valid: ‘%(name)s’ and ‘%%’, the latter being an escaped
          percent sign.

        * The *note set(): 1474. and *note add_section(): 1475. methods
          now verify that values are actual strings.  Formerly,
          unsupported types could be introduced unintentionally.

        * Duplicate sections or options from a single source now raise
          either *note DuplicateSectionError: 1476. or *note
          DuplicateOptionError: 1477.  Formerly, duplicates would
          silently overwrite a previous entry.

        * Inline comments are now disabled by default so now the ';'
          character can be safely used in values.

        * Comments now can be indented.  Consequently, for ';' or '#' to
          appear at the start of a line in multiline values, it has to
          be interpolated.  This keeps comment prefix characters in
          values from being mistaken as comments.

        * ‘""’ is now a valid value and is no longer automatically
          converted to an empty string.  For empty strings, use ‘"option
          ="’ in a line.

   * The ‘nntplib’ module was reworked extensively, meaning that its
     APIs are often incompatible with the 3.1 APIs.

   * *note bytearray: 344. objects can no longer be used as filenames;
     instead, they should be converted to *note bytes: 192.

   * The ‘array.tostring()’ and ‘array.fromstring()’ have been renamed
     to *note array.tobytes(): 1478. and *note array.frombytes(): 1479.
     for clarity.  The old names have been deprecated.  (See
     bpo-8990(1).)

   * ‘PyArg_Parse*()’ functions:

        * «t#» format has been removed: use «s#» or «s*» instead

        * «w» and «w#» formats has been removed: use «w*» instead

   * The ‘PyCObject’ type, deprecated in 3.1, has been removed.  To wrap
     opaque C pointers in Python objects, the *note PyCapsule: 147a. API
     should be used instead; the new type has a well-defined interface
     for passing typing safety information and a less complicated
     signature for calling a destructor.

   * The ‘sys.setfilesystemencoding()’ function was removed because it
     had a flawed design.

   * The *note random.seed(): 147b. function and method now salt string
     seeds with an sha512 hash function.  To access the previous version
     of 'seed' in order to reproduce Python 3.1 sequences, set the
     'version' argument to '1', ‘random.seed(s, version=1)’.

   * The previously deprecated ‘string.maketrans()’ function has been
     removed in favor of the static methods *note bytes.maketrans():
     147c. and *note bytearray.maketrans(): 147d.  This change solves
     the confusion around which types were supported by the *note
     string: d8. module.  Now, *note str: 169, *note bytes: 192, and
     *note bytearray: 344. each have their own 'maketrans' and
     'translate' methods with intermediate translation tables of the
     appropriate type.

     (Contributed by Georg Brandl; bpo-5675(2).)

   * The previously deprecated ‘contextlib.nested()’ function has been
     removed in favor of a plain *note with: 186. statement which can
     accept multiple context managers.  The latter technique is faster
     (because it is built-in), and it does a better job finalizing
     multiple context managers when one of them raises an exception:

          with open('mylog.txt') as infile, open('a.out', 'w') as outfile:
              for line in infile:
                  if '<critical>' in line:
                      outfile.write(line)

     (Contributed by Georg Brandl and Mattias Brändström; appspot issue
     53094(3).)

   * *note struct.pack(): 147e. now only allows bytes for the ‘s’ string
     pack code.  Formerly, it would accept text arguments and implicitly
     encode them to bytes using UTF-8.  This was problematic because it
     made assumptions about the correct encoding and because a
     variable-length encoding can fail when writing to fixed length
     segment of a structure.

     Code such as ‘struct.pack('<6sHHBBB', 'GIF87a', x, y)’ should be
     rewritten with to use bytes instead of text,
     ‘struct.pack('<6sHHBBB', b'GIF87a', x, y)’.

     (Discovered by David Beazley and fixed by Victor Stinner;
     bpo-10783(4).)

   * The *note xml.etree.ElementTree: 12b. class now raises an *note
     xml.etree.ElementTree.ParseError: 147f. when a parse fails.
     Previously it raised an *note xml.parsers.expat.ExpatError: 1480.

   * The new, longer *note str(): 169. value on floats may break
     doctests which rely on the old output format.

   * In *note subprocess.Popen: 4b8, the default value for 'close_fds'
     is now ‘True’ under Unix; under Windows, it is ‘True’ if the three
     standard streams are set to ‘None’, ‘False’ otherwise.  Previously,
     'close_fds' was always ‘False’ by default, which produced difficult
     to solve bugs or race conditions when open file descriptors would
     leak into the child process.

   * Support for legacy HTTP 0.9 has been removed from *note
     urllib.request: 111. and *note http.client: 73.  Such support is
     still present on the server side (in *note http.server: 76.).

     (Contributed by Antoine Pitrou, bpo-10711(5).)

   * SSL sockets in timeout mode now raise *note socket.timeout: a37.
     when a timeout occurs, rather than a generic *note SSLError: 1481.

     (Contributed by Antoine Pitrou, bpo-10272(6).)

   * The misleading functions ‘PyEval_AcquireLock()’ and
     ‘PyEval_ReleaseLock()’ have been officially deprecated.  The
     thread-state aware APIs (such as *note PyEval_SaveThread(): 647.
     and *note PyEval_RestoreThread(): 648.) should be used instead.

   * Due to security risks, ‘asyncore.handle_accept()’ has been
     deprecated, and a new function, ‘asyncore.handle_accepted()’, was
     added to replace it.

     (Contributed by Giampaolo Rodola in bpo-6706(7).)

   * Due to the new *note GIL: 164. implementation,
     ‘PyEval_InitThreads()’ cannot be called before *note
     Py_Initialize(): 460. anymore.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8990

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5675

   (3) https://codereview.appspot.com/53094

   (4) https://bugs.python.org/issue?@action=redirect&bpo=10783

   (5) https://bugs.python.org/issue?@action=redirect&bpo=10711

   (6) https://bugs.python.org/issue?@action=redirect&bpo=10272

   (7) https://bugs.python.org/issue?@action=redirect&bpo=6706


File: python.info,  Node: What’s New In Python 3 1,  Next: What’s New In Python 3 0,  Prev: What’s New In Python 3 2,  Up: Novità in Python

1.14 What’s New In Python 3.1
=============================


Author: Raymond Hettinger

This article explains the new features in Python 3.1, compared to 3.0.
Python 3.1 was released on June 27, 2009.

* Menu:

* PEP 372; Ordered Dictionaries: PEP 372 Ordered Dictionaries.
* PEP 378; Format Specifier for Thousands Separator: PEP 378 Format Specifier for Thousands Separator.
* Other Language Changes: Other Language Changes<12>.
* New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<2>.
* Optimizations: Optimizations<12>.
* IDLE: IDLE<2>.
* Build and C API Changes: Build and C API Changes<6>.
* Porting to Python 3.1: Porting to Python 3 1.


File: python.info,  Node: PEP 372 Ordered Dictionaries,  Next: PEP 378 Format Specifier for Thousands Separator,  Up: What’s New In Python 3 1

1.14.1 PEP 372: Ordered Dictionaries
------------------------------------

Regular Python dictionaries iterate over key/value pairs in arbitrary
order.  Over the years, a number of authors have written alternative
implementations that remember the order that the keys were originally
inserted.  Based on the experiences from those implementations, a new
*note collections.OrderedDict: 7f4. class has been introduced.

The OrderedDict API is substantially the same as regular dictionaries
but will iterate over keys and values in a guaranteed order depending on
when a key was first inserted.  If a new entry overwrites an existing
entry, the original insertion position is left unchanged.  Deleting an
entry and reinserting it will move it to the end.

The standard library now supports use of ordered dictionaries in several
modules.  The *note configparser: 26. module uses them by default.  This
lets configuration files be read, modified, and then written back in
their original order.  The '_asdict()' method for *note
collections.namedtuple(): 4e1. now returns an ordered dictionary with
the values appearing in the same order as the underlying tuple indices.
The *note json: 86. module is being built-out with an
'object_pairs_hook' to allow OrderedDicts to be built by the decoder.
Support was also added for third-party tools like PyYAML(1).

Vedi anche
..........

PEP 372(2) - Ordered Dictionaries

     PEP written by Armin Ronacher and Raymond Hettinger.
     Implementation written by Raymond Hettinger.

Since an ordered dictionary remembers its insertion order, it can be
used in conjunction with sorting to make a sorted dictionary:

     >>> # regular unsorted dictionary
     >>> d = {'banana': 3, 'apple':4, 'pear': 1, 'orange': 2}

     >>> # dictionary sorted by key
     >>> OrderedDict(sorted(d.items(), key=lambda t: t[0]))
     OrderedDict([('apple', 4), ('banana', 3), ('orange', 2), ('pear', 1)])

     >>> # dictionary sorted by value
     >>> OrderedDict(sorted(d.items(), key=lambda t: t[1]))
     OrderedDict([('pear', 1), ('orange', 2), ('banana', 3), ('apple', 4)])

     >>> # dictionary sorted by length of the key string
     >>> OrderedDict(sorted(d.items(), key=lambda t: len(t[0])))
     OrderedDict([('pear', 1), ('apple', 4), ('orange', 2), ('banana', 3)])

The new sorted dictionaries maintain their sort order when entries are
deleted.  But when new keys are added, the keys are appended to the end
and the sort is not maintained.

   ---------- Footnotes ----------

   (1) https://pyyaml.org/

   (2) https://peps.python.org/pep-0372/


File: python.info,  Node: PEP 378 Format Specifier for Thousands Separator,  Next: Other Language Changes<12>,  Prev: PEP 372 Ordered Dictionaries,  Up: What’s New In Python 3 1

1.14.2 PEP 378: Format Specifier for Thousands Separator
--------------------------------------------------------

The built-in *note format(): 199. function and the *note str.format():
834. method use a mini-language that now includes a simple, non-locale
aware way to format a number with a thousands separator.  That provides
a way to humanize a program’s output, improving its professional
appearance and readability:

     >>> format(1234567, ',d')
     '1,234,567'
     >>> format(1234567.89, ',.2f')
     '1,234,567.89'
     >>> format(12345.6 + 8901234.12j, ',f')
     '12,345.600000+8,901,234.120000j'
     >>> format(Decimal('1234567.89'), ',f')
     '1,234,567.89'

The supported types are *note int: 19b, *note float: 196, *note complex:
197. and *note decimal.Decimal: 1fe.

Discussions are underway about how to specify alternative separators
like dots, spaces, apostrophes, or underscores.  Locale-aware
applications should use the existing 'n' format specifier which already
has some support for thousands separators.

Vedi anche
..........

PEP 378(1) - Format Specifier for Thousands Separator

     PEP written by Raymond Hettinger and implemented by Eric Smith and
     Mark Dickinson.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0378/


File: python.info,  Node: Other Language Changes<12>,  Next: New Improved and Deprecated Modules<2>,  Prev: PEP 378 Format Specifier for Thousands Separator,  Up: What’s New In Python 3 1

1.14.3 Other Language Changes
-----------------------------

Some smaller changes made to the core Python language are:

   * Directories and zip archives containing a ‘__main__.py’ file can
     now be executed directly by passing their name to the interpreter.
     The directory/zipfile is automatically inserted as the first entry
     in sys.path.  (Suggestion and initial patch by Andy Chu; revised
     patch by Phillip J. Eby and Nick Coghlan; bpo-1739468(1).)

   * The *note int(): 19b. type gained a ‘bit_length’ method that
     returns the number of bits necessary to represent its argument in
     binary:

          >>> n = 37
          >>> bin(37)
          '0b100101'
          >>> n.bit_length()
          6
          >>> n = 2**123-1
          >>> n.bit_length()
          123
          >>> (n+1).bit_length()
          124

     (Contributed by Fredrik Johansson, Victor Stinner, Raymond
     Hettinger, and Mark Dickinson; bpo-3439(2).)

   * The fields in *note format(): 199. strings can now be automatically
     numbered:

          >>> 'Sir {} of {}'.format('Gallahad', 'Camelot')
          'Sir Gallahad of Camelot'

     Formerly, the string would have required numbered fields such as:
     ‘'Sir {0} of {1}'’.

     (Contributed by Eric Smith; bpo-5237(3).)

   * The ‘string.maketrans()’ function is deprecated and is replaced by
     new static methods, *note bytes.maketrans(): 147c. and *note
     bytearray.maketrans(): 147d.  This change solves the confusion
     around which types were supported by the *note string: d8. module.
     Now, *note str: 169, *note bytes: 192, and *note bytearray: 344.
     each have their own 'maketrans' and 'translate' methods with
     intermediate translation tables of the appropriate type.

     (Contributed by Georg Brandl; bpo-5675(4).)

   * The syntax of the *note with: 186. statement now allows multiple
     context managers in a single statement:

          >>> with open('mylog.txt') as infile, open('a.out', 'w') as outfile:
          ...     for line in infile:
          ...         if '<critical>' in line:
          ...             outfile.write(line)

     With the new syntax, the ‘contextlib.nested()’ function is no
     longer needed and is now deprecated.

     (Contributed by Georg Brandl and Mattias Brändström; appspot issue
     53094(5).)

   * ‘round(x, n)’ now returns an integer if 'x' is an integer.
     Previously it returned a float:

          >>> round(1123, -2)
          1100

     (Contributed by Mark Dickinson; bpo-4707(6).)

   * Python now uses David Gay’s algorithm for finding the shortest
     floating-point representation that doesn’t change its value.  This
     should help mitigate some of the confusion surrounding binary
     floating-point numbers.

     The significance is easily seen with a number like ‘1.1’ which does
     not have an exact equivalent in binary floating point.  Since there
     is no exact equivalent, an expression like ‘float('1.1')’ evaluates
     to the nearest representable value which is ‘0x1.199999999999ap+0’
     in hex or ‘1.100000000000000088817841970012523233890533447265625’
     in decimal.  That nearest value was and still is used in subsequent
     floating-point calculations.

     What is new is how the number gets displayed.  Formerly, Python
     used a simple approach.  The value of ‘repr(1.1)’ was computed as
     ‘format(1.1, '.17g')’ which evaluated to ‘'1.1000000000000001'’.
     The advantage of using 17 digits was that it relied on IEEE-754
     guarantees to assure that ‘eval(repr(1.1))’ would round-trip
     exactly to its original value.  The disadvantage is that many
     people found the output to be confusing (mistaking intrinsic
     limitations of binary floating-point representation as being a
     problem with Python itself).

     The new algorithm for ‘repr(1.1)’ is smarter and returns ‘'1.1'’.
     Effectively, it searches all equivalent string representations
     (ones that get stored with the same underlying float value) and
     returns the shortest representation.

     The new algorithm tends to emit cleaner representations when
     possible, but it does not change the underlying values.  So, it is
     still the case that ‘1.1 + 2.2 != 3.3’ even though the
     representations may suggest otherwise.

     The new algorithm depends on certain features in the underlying
     floating-point implementation.  If the required features are not
     found, the old algorithm will continue to be used.  Also, the text
     pickle protocols assure cross-platform portability by using the old
     algorithm.

     (Contributed by Eric Smith and Mark Dickinson; bpo-1580(7))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1739468

   (2) https://bugs.python.org/issue?@action=redirect&bpo=3439

   (3) https://bugs.python.org/issue?@action=redirect&bpo=5237

   (4) https://bugs.python.org/issue?@action=redirect&bpo=5675

   (5) https://codereview.appspot.com/53094

   (6) https://bugs.python.org/issue?@action=redirect&bpo=4707

   (7) https://bugs.python.org/issue?@action=redirect&bpo=1580


File: python.info,  Node: New Improved and Deprecated Modules<2>,  Next: Optimizations<12>,  Prev: Other Language Changes<12>,  Up: What’s New In Python 3 1

1.14.4 New, Improved, and Deprecated Modules
--------------------------------------------

   * Added a *note collections.Counter: 1299. class to support
     convenient counting of unique items in a sequence or iterable:

          >>> Counter(['red', 'blue', 'red', 'green', 'blue', 'blue'])
          Counter({'blue': 3, 'red': 2, 'green': 1})

     (Contributed by Raymond Hettinger; bpo-1696199(1).)

   * Added a new module, *note tkinter.ttk: ff. for access to the Tk
     themed widget set.  The basic idea of ttk is to separate, to the
     extent possible, the code implementing a widget’s behavior from the
     code implementing its appearance.

     (Contributed by Guilherme Polo; bpo-2983(2).)

   * The *note gzip.GzipFile: 65c. and *note bz2.BZ2File: a68. classes
     now support the context management protocol:

          >>> # Automatically close file after writing
          >>> with gzip.GzipFile(filename, "wb") as f:
          ...     f.write(b"xxx")

     (Contributed by Antoine Pitrou.)

   * The *note decimal: 3a. module now supports methods for creating a
     decimal object from a binary *note float: 196.  The conversion is
     exact but can sometimes be surprising:

          >>> Decimal.from_float(1.1)
          Decimal('1.100000000000000088817841970012523233890533447265625')

     The long decimal result shows the actual binary fraction being
     stored for '1.1'.  The fraction has many digits because '1.1'
     cannot be exactly represented in binary.

     (Contributed by Raymond Hettinger and Mark Dickinson.)

   * The *note itertools: 85. module grew two new functions.  The *note
     itertools.combinations_with_replacement(): 1489. function is one of
     four for generating combinatorics including permutations and
     Cartesian products.  The *note itertools.compress(): 148a. function
     mimics its namesake from APL. Also, the existing *note
     itertools.count(): 148b. function now has an optional 'step'
     argument and can accept any type of counting sequence including
     *note fractions.Fraction: 213. and *note decimal.Decimal: 1fe.:

          >>> [p+q for p,q in combinations_with_replacement('LOVE', 2)]
          ['LL', 'LO', 'LV', 'LE', 'OO', 'OV', 'OE', 'VV', 'VE', 'EE']

          >>> list(compress(data=range(10), selectors=[0,0,1,1,0,1,0,1,0,0]))
          [2, 3, 5, 7]

          >>> c = count(start=Fraction(1,2), step=Fraction(1,6))
          >>> [next(c), next(c), next(c), next(c)]
          [Fraction(1, 2), Fraction(2, 3), Fraction(5, 6), Fraction(1, 1)]

     (Contributed by Raymond Hettinger.)

   * *note collections.namedtuple(): 4e1. now supports a keyword
     argument 'rename' which lets invalid fieldnames be automatically
     converted to positional names in the form _0, _1, etc.  This is
     useful when the field names are being created by an external source
     such as a CSV header, SQL field list, or user input:

          >>> query = input()
          SELECT region, dept, count(*) FROM main GROUPBY region, dept

          >>> cursor.execute(query)
          >>> query_fields = [desc[0] for desc in cursor.description]
          >>> UserQuery = namedtuple('UserQuery', query_fields, rename=True)
          >>> pprint.pprint([UserQuery(*row) for row in cursor])
          [UserQuery(region='South', dept='Shipping', _2=185),
           UserQuery(region='North', dept='Accounting', _2=37),
           UserQuery(region='West', dept='Sales', _2=419)]

     (Contributed by Raymond Hettinger; bpo-1818(3).)

   * The *note re.sub(): 5a3, *note re.subn(): 5a4. and *note
     re.split(): 5a2. functions now accept a flags parameter.

     (Contributed by Gregory Smith.)

   * The *note logging: 8b. module now implements a simple *note
     logging.NullHandler: 148c. class for applications that are not
     using logging but are calling library code that does.  Setting-up a
     null handler will suppress spurious warnings such as «No handlers
     could be found for logger foo»:

          >>> h = logging.NullHandler()
          >>> logging.getLogger("foo").addHandler(h)

     (Contributed by Vinay Sajip; bpo-4384(4)).

   * The *note runpy: c3. module which supports the ‘-m’ command line
     switch now supports the execution of packages by looking for and
     executing a ‘__main__’ submodule when a package name is supplied.

     (Contributed by Andi Vajda; bpo-4195(5).)

   * The *note pdb: aa. module can now access and display source code
     loaded via *note zipimport: 138. (or any other conformant PEP
     302(6) loader).

     (Contributed by Alexander Belopolsky; bpo-4201(7).)

   * *note functools.partial: 217. objects can now be pickled.

     (Suggested by Antoine Pitrou and Jesse Noller.  Implemented by Jack
     Diederich; bpo-5228(8).)

   * Add *note pydoc: ba. help topics for symbols so that ‘help('@')’
     works as expected in the interactive environment.

     (Contributed by David Laban; bpo-4739(9).)

   * The *note unittest: 10c. module now supports skipping individual
     tests or classes of tests.  And it supports marking a test as an
     expected failure, a test that is known to be broken, but shouldn’t
     be counted as a failure on a TestResult:

          class TestGizmo(unittest.TestCase):

              @unittest.skipUnless(sys.platform.startswith("win"), "requires Windows")
              def test_gizmo_on_windows(self):
                  ...

              @unittest.expectedFailure
              def test_gimzo_without_required_library(self):
                  ...

     Also, tests for exceptions have been builtout to work with context
     managers using the *note with: 186. statement:

          def test_division_by_zero(self):
              with self.assertRaises(ZeroDivisionError):
                  x / 0

     In addition, several new assertion methods were added including
     *note assertSetEqual(): 148d, *note assertDictEqual(): 148e,
     ‘assertDictContainsSubset()’, *note assertListEqual(): 148f, *note
     assertTupleEqual(): 1490, *note assertSequenceEqual(): 1491, *note
     assertRaisesRegexp(): 753, *note assertIsNone(): 1492, and *note
     assertIsNotNone(): 1493.

     (Contributed by Benjamin Peterson and Antoine Pitrou.)

   * The *note io: 83. module has three new constants for the *note
     seek(): 1494. method: *note SEEK_SET: 1495, *note SEEK_CUR: 1496,
     and *note SEEK_END: 1497.

   * The *note sys.version_info: 8b0. tuple is now a named tuple:

          >>> sys.version_info
          sys.version_info(major=3, minor=1, micro=0, releaselevel='alpha', serial=2)

     (Contributed by Ross Light; bpo-4285(10).)

   * The ‘nntplib’ and *note imaplib: 78. modules now support IPv6.

     (Contributed by Derek Morr; bpo-1655(11) and bpo-1664(12).)

   * The *note pickle: ab. module has been adapted for better
     interoperability with Python 2.x when used with protocol 2 or
     lower.  The reorganization of the standard library changed the
     formal reference for many objects.  For example, ‘__builtin__.set’
     in Python 2 is called ‘builtins.set’ in Python 3.  This change
     confounded efforts to share data between different versions of
     Python.  But now when protocol 2 or lower is selected, the pickler
     will automatically use the old Python 2 names for both loading and
     dumping.  This remapping is turned-on by default but can be
     disabled with the 'fix_imports' option:

          >>> s = {1, 2, 3}
          >>> pickle.dumps(s, protocol=0)
          b'c__builtin__\nset\np0\n((lp1\nL1L\naL2L\naL3L\natp2\nRp3\n.'
          >>> pickle.dumps(s, protocol=0, fix_imports=False)
          b'cbuiltins\nset\np0\n((lp1\nL1L\naL2L\naL3L\natp2\nRp3\n.'

     An unfortunate but unavoidable side-effect of this change is that
     protocol 2 pickles produced by Python 3.1 won’t be readable with
     Python 3.0.  The latest pickle protocol, protocol 3, should be used
     when migrating data between Python 3.x implementations, as it
     doesn’t attempt to remain compatible with Python 2.x.

     (Contributed by Alexandre Vassalotti and Antoine Pitrou,
     bpo-6137(13).)

   * A new module, *note importlib: 7b. was added.  It provides a
     complete, portable, pure Python reference implementation of the
     *note import: 7f9. statement and its counterpart, the *note
     __import__(): ad3. function.  It represents a substantial step
     forward in documenting and defining the actions that take place
     during imports.

     (Contributed by Brett Cannon.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1696199

   (2) https://bugs.python.org/issue?@action=redirect&bpo=2983

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1818

   (4) https://bugs.python.org/issue?@action=redirect&bpo=4384

   (5) https://bugs.python.org/issue?@action=redirect&bpo=4195

   (6) https://peps.python.org/pep-0302/

   (7) https://bugs.python.org/issue?@action=redirect&bpo=4201

   (8) https://bugs.python.org/issue?@action=redirect&bpo=5228

   (9) https://bugs.python.org/issue?@action=redirect&bpo=4739

   (10) https://bugs.python.org/issue?@action=redirect&bpo=4285

   (11) https://bugs.python.org/issue?@action=redirect&bpo=1655

   (12) https://bugs.python.org/issue?@action=redirect&bpo=1664

   (13) https://bugs.python.org/issue?@action=redirect&bpo=6137


File: python.info,  Node: Optimizations<12>,  Next: IDLE<2>,  Prev: New Improved and Deprecated Modules<2>,  Up: What’s New In Python 3 1

1.14.5 Optimizations
--------------------

Major performance enhancements have been added:

   * The new I/O library (as defined in PEP 3116(1)) was mostly written
     in Python and quickly proved to be a problematic bottleneck in
     Python 3.0.  In Python 3.1, the I/O library has been entirely
     rewritten in C and is 2 to 20 times faster depending on the task at
     hand.  The pure Python version is still available for
     experimentation purposes through the ‘_pyio’ module.

     (Contributed by Amaury Forgeot d’Arc and Antoine Pitrou.)

   * Added a heuristic so that tuples and dicts containing only
     untrackable objects are not tracked by the garbage collector.  This
     can reduce the size of collections and therefore the garbage
     collection overhead on long-running programs, depending on their
     particular use of datatypes.

     (Contributed by Antoine Pitrou, bpo-4688(2).)

   * Enabling a configure option named ‘--with-computed-gotos’ on
     compilers that support it (notably: gcc, SunPro, icc), the bytecode
     evaluation loop is compiled with a new dispatch mechanism which
     gives speedups of up to 20%, depending on the system, the compiler,
     and the benchmark.

     (Contributed by Antoine Pitrou along with a number of other
     participants, bpo-4753(3)).

   * The decoding of UTF-8, UTF-16 and LATIN-1 is now two to four times
     faster.

     (Contributed by Antoine Pitrou and Amaury Forgeot d’Arc,
     bpo-4868(4).)

   * The *note json: 86. module now has a C extension to substantially
     improve its performance.  In addition, the API was modified so that
     json works only with *note str: 169, not with *note bytes: 192.
     That change makes the module closely match the JSON
     specification(5) which is defined in terms of Unicode.

     (Contributed by Bob Ippolito and converted to Py3.1 by Antoine
     Pitrou and Benjamin Peterson; bpo-4136(6).)

   * Unpickling now interns the attribute names of pickled objects.
     This saves memory and allows pickles to be smaller.

     (Contributed by Jake McGuire and Antoine Pitrou; bpo-5084(7).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3116/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=4688

   (3) https://bugs.python.org/issue?@action=redirect&bpo=4753

   (4) https://bugs.python.org/issue?@action=redirect&bpo=4868

   (5) https://json.org/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=4136

   (7) https://bugs.python.org/issue?@action=redirect&bpo=5084


File: python.info,  Node: IDLE<2>,  Next: Build and C API Changes<6>,  Prev: Optimizations<12>,  Up: What’s New In Python 3 1

1.14.6 IDLE
-----------

   * IDLE’s format menu now provides an option to strip trailing
     whitespace from a source file.

     (Contributed by Roger D. Serwy; bpo-5150(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5150


File: python.info,  Node: Build and C API Changes<6>,  Next: Porting to Python 3 1,  Prev: IDLE<2>,  Up: What’s New In Python 3 1

1.14.7 Build and C API Changes
------------------------------

Changes to Python’s build process and to the C API include:

   * Integers are now stored internally either in base ‘2**15’ or in
     base ‘2**30’, the base being determined at build time.  Previously,
     they were always stored in base ‘2**15’.  Using base ‘2**30’ gives
     significant performance improvements on 64-bit machines, but
     benchmark results on 32-bit machines have been mixed.  Therefore,
     the default is to use base ‘2**30’ on 64-bit machines and base
     ‘2**15’ on 32-bit machines; on Unix, there’s a new configure option
     ‘--enable-big-digits’ that can be used to override this default.

     Apart from the performance improvements this change should be
     invisible to end users, with one exception: for testing and
     debugging purposes there’s a new *note sys.int_info: 149b. that
     provides information about the internal format, giving the number
     of bits per digit and the size in bytes of the C type used to store
     each digit:

          >>> import sys
          >>> sys.int_info
          sys.int_info(bits_per_digit=30, sizeof_digit=4)

     (Contributed by Mark Dickinson; bpo-4258(1).)

   * The *note PyLong_AsUnsignedLongLong(): 149c. function now handles a
     negative 'pylong' by raising *note OverflowError: a83. instead of
     *note TypeError: 198.

     (Contributed by Mark Dickinson and Lisandro Dalcrin; bpo-5175(2).)

   * Deprecated ‘PyNumber_Int()’.  Use *note PyNumber_Long(): c5f.
     instead.

     (Contributed by Mark Dickinson; bpo-4910(3).)

   * Added a new *note PyOS_string_to_double(): 149d. function to
     replace the deprecated functions ‘PyOS_ascii_strtod()’ and
     ‘PyOS_ascii_atof()’.

     (Contributed by Mark Dickinson; bpo-5914(4).)

   * Added *note PyCapsule: 147a. as a replacement for the ‘PyCObject’
     API. The principal difference is that the new type has a well
     defined interface for passing typing safety information and a less
     complicated signature for calling a destructor.  The old type had a
     problematic API and is now deprecated.

     (Contributed by Larry Hastings; bpo-5630(5).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4258

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5175

   (3) https://bugs.python.org/issue?@action=redirect&bpo=4910

   (4) https://bugs.python.org/issue?@action=redirect&bpo=5914

   (5) https://bugs.python.org/issue?@action=redirect&bpo=5630


File: python.info,  Node: Porting to Python 3 1,  Prev: Build and C API Changes<6>,  Up: What’s New In Python 3 1

1.14.8 Porting to Python 3.1
----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code:

   * The new floating-point string representations can break existing
     doctests.  For example:

          def e():
              '''Compute the base of natural logarithms.

              >>> e()
              2.7182818284590451

              '''
              return sum(1/math.factorial(x) for x in reversed(range(30)))

          doctest.testmod()

          **********************************************************************
          Failed example:
              e()
          Expected:
              2.7182818284590451
          Got:
              2.718281828459045
          **********************************************************************

   * The automatic name remapping in the pickle module for protocol 2 or
     lower can make Python 3.1 pickles unreadable in Python 3.0.  One
     solution is to use protocol 3.  Another solution is to set the
     'fix_imports' option to ‘False’.  See the discussion above for more
     details.


File: python.info,  Node: What’s New In Python 3 0,  Next: What’s New in Python 2 7,  Prev: What’s New In Python 3 1,  Up: Novità in Python

1.15 What’s New In Python 3.0
=============================


Author: Guido van Rossum

This article explains the new features in Python 3.0, compared to 2.6.
Python 3.0, also known as «Python 3000» or «Py3K», is the first ever
'intentionally backwards incompatible' Python release.  Python 3.0 was
released on December 3, 2008.  There are more changes than in a typical
release, and more that are important for all Python users.
Nevertheless, after digesting the changes, you’ll find that Python
really hasn’t changed all that much – by and large, we’re mostly fixing
well-known annoyances and warts, and removing a lot of old cruft.

This article doesn’t attempt to provide a complete specification of all
new features, but instead tries to give a convenient overview.  For full
details, you should refer to the documentation for Python 3.0, and/or
the many PEPs referenced in the text.  If you want to understand the
complete implementation and design rationale for a particular feature,
PEPs usually have more details than the regular documentation; but note
that PEPs usually are not kept up-to-date once a feature has been fully
implemented.

Due to time constraints this document is not as complete as it should
have been.  As always for a new release, the ‘Misc/NEWS’ file in the
source distribution contains a wealth of detailed information about
every small thing that was changed.

* Menu:

* Common Stumbling Blocks::
* Overview Of Syntax Changes::
* Changes Already Present In Python 2.6: Changes Already Present In Python 2 6.
* Library Changes::
* PEP 3101; A New Approach To String Formatting: PEP 3101 A New Approach To String Formatting.
* Changes To Exceptions::
* Miscellaneous Other Changes::
* Build and C API Changes: Build and C API Changes<7>.
* Performance::
* Porting To Python 3.0: Porting To Python 3 0.


File: python.info,  Node: Common Stumbling Blocks,  Next: Overview Of Syntax Changes,  Up: What’s New In Python 3 0

1.15.1 Common Stumbling Blocks
------------------------------

This section lists those few changes that are most likely to trip you up
if you’re used to Python 2.5.

* Menu:

* Print Is A Function::
* Views And Iterators Instead Of Lists::
* Ordering Comparisons::
* Integers::
* Text Vs. Data Instead Of Unicode Vs. 8-bit: Text Vs Data Instead Of Unicode Vs 8-bit.


File: python.info,  Node: Print Is A Function,  Next: Views And Iterators Instead Of Lists,  Up: Common Stumbling Blocks

1.15.1.1 Print Is A Function
............................

The ‘print’ statement has been replaced with a *note print(): 1177.
function, with keyword arguments to replace most of the special syntax
of the old ‘print’ statement ( PEP 3105(1)).  Examples:

     Old: print "The answer is", 2*2
     New: print("The answer is", 2*2)

     Old: print x,           # Trailing comma suppresses newline
     New: print(x, end=" ")  # Appends a space instead of a newline

     Old: print              # Prints a newline
     New: print()            # You must call the function!

     Old: print >>sys.stderr, "fatal error"
     New: print("fatal error", file=sys.stderr)

     Old: print (x, y)       # prints repr((x, y))
     New: print((x, y))      # Not the same as print(x, y)!

You can also customize the separator between items, e.g.:

     print("There are <", 2**32, "> possibilities!", sep="")

which produces:

     There are <4294967296> possibilities!

Note:

   * The *note print(): 1177. function doesn’t support the «softspace»
     feature of the old ‘print’ statement.  For example, in Python 2.x,
     ‘print "A\n", "B"’ would write ‘"A\nB\n"’; but in Python 3.0,
     ‘print("A\n", "B")’ writes ‘"A\n B\n"’.

   * Initially, you’ll be finding yourself typing the old ‘print x’ a
     lot in interactive mode.  Time to retrain your fingers to type
     ‘print(x)’ instead!

   * When using the ‘2to3’ source-to-source conversion tool, all ‘print’
     statements are automatically converted to *note print(): 1177.
     function calls, so this is mostly a non-issue for larger projects.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3105/


File: python.info,  Node: Views And Iterators Instead Of Lists,  Next: Ordering Comparisons,  Prev: Print Is A Function,  Up: Common Stumbling Blocks

1.15.1.2 Views And Iterators Instead Of Lists
.............................................

Some well-known APIs no longer return lists:

   * *note dict: 183. methods *note dict.keys(): 9d2, *note
     dict.items(): 9d4. and *note dict.values(): 9d3. return «views»
     instead of lists.  For example, this no longer works: ‘k =
     d.keys(); k.sort()’.  Use ‘k = sorted(d)’ instead (this works in
     Python 2.5 too and is just as efficient).

   * Also, the ‘dict.iterkeys()’, ‘dict.iteritems()’ and
     ‘dict.itervalues()’ methods are no longer supported.

   * *note map(): 19f. and *note filter(): a66. return iterators.  If
     you really need a list and the input sequences are all of equal
     length, a quick fix is to wrap *note map(): 19f. in *note list():
     24d, e.g.  ‘list(map(...))’, but a better fix is often to use a
     list comprehension (especially when the original code uses *note
     lambda: 14a5.), or rewriting the code so it doesn’t need a list at
     all.  Particularly tricky is *note map(): 19f. invoked for the side
     effects of the function; the correct transformation is to use a
     regular *note for: 34a. loop (since creating a list would just be
     wasteful).

     If the input sequences are not of equal length, *note map(): 19f.
     will stop at the termination of the shortest of the sequences.  For
     full compatibility with *note map(): 19f. from Python 2.x, also
     wrap the sequences in *note itertools.zip_longest(): 14a6, e.g.
     ‘map(func, *sequences)’ becomes ‘list(map(func,
     itertools.zip_longest(*sequences)))’.

   * *note range(): b3f. now behaves like ‘xrange()’ used to behave,
     except it works with values of arbitrary size.  The latter no
     longer exists.

   * *note zip(): 1a0. now returns an iterator.


File: python.info,  Node: Ordering Comparisons,  Next: Integers,  Prev: Views And Iterators Instead Of Lists,  Up: Common Stumbling Blocks

1.15.1.3 Ordering Comparisons
.............................

Python 3.0 has simplified the rules for ordering comparisons:

   * The ordering comparison operators (‘<’, ‘<=’, ‘>=’, ‘>’) raise a
     TypeError exception when the operands don’t have a meaningful
     natural ordering.  Thus, expressions like ‘1 < ''’, ‘0 > None’ or
     ‘len <= len’ are no longer valid, and e.g.  ‘None < None’ raises
     *note TypeError: 198. instead of returning ‘False’.  A corollary is
     that sorting a heterogeneous list no longer makes sense – all the
     elements must be comparable to each other.  Note that this does not
     apply to the ‘==’ and ‘!=’ operators: objects of different
     incomparable types always compare unequal to each other.

   * *note sorted(): dc9. and *note list.sort(): dca. no longer accept
     the 'cmp' argument providing a comparison function.  Use the 'key'
     argument instead.  N.B. the 'key' and 'reverse' arguments are now
     «keyword-only».

   * The ‘cmp()’ function should be treated as gone, and the ‘__cmp__()’
     special method is no longer supported.  Use *note __lt__(): 14a8.
     for sorting, *note __eq__(): cf4. with *note __hash__(): cf5, and
     other rich comparisons as needed.  (If you really need the ‘cmp()’
     functionality, you could use the expression ‘(a > b) - (a < b)’ as
     the equivalent for ‘cmp(a, b)’.)


File: python.info,  Node: Integers,  Next: Text Vs Data Instead Of Unicode Vs 8-bit,  Prev: Ordering Comparisons,  Up: Common Stumbling Blocks

1.15.1.4 Integers
.................

   * PEP 237(1): Essentially, ‘long’ renamed to *note int: 19b.  That
     is, there is only one built-in integral type, named *note int:
     19b.; but it behaves mostly like the old ‘long’ type.

   * PEP 238(2): An expression like ‘1/2’ returns a float.  Use ‘1//2’
     to get the truncating behavior.  (The latter syntax has existed for
     years, at least since Python 2.2.)

   * The ‘sys.maxint’ constant was removed, since there is no longer a
     limit to the value of integers.  However, *note sys.maxsize: 13cd.
     can be used as an integer larger than any practical list or string
     index.  It conforms to the implementation’s «natural» integer size
     and is typically the same as ‘sys.maxint’ in previous releases on
     the same platform (assuming the same build options).

   * The *note repr(): 1c1. of a long integer doesn’t include the
     trailing ‘L’ anymore, so code that unconditionally strips that
     character will chop off the last digit instead.  (Use *note str():
     169. instead.)

   * Octal literals are no longer of the form ‘0720’; use ‘0o720’
     instead.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0237/

   (2) https://peps.python.org/pep-0238/


File: python.info,  Node: Text Vs Data Instead Of Unicode Vs 8-bit,  Prev: Integers,  Up: Common Stumbling Blocks

1.15.1.5 Text Vs. Data Instead Of Unicode Vs. 8-bit
...................................................

Everything you thought you knew about binary data and Unicode has
changed.

   * Python 3.0 uses the concepts of 'text' and (binary) 'data' instead
     of Unicode strings and 8-bit strings.  All text is Unicode; however
     'encoded' Unicode is represented as binary data.  The type used to
     hold text is *note str: 169, the type used to hold data is *note
     bytes: 192.  The biggest difference with the 2.x situation is that
     any attempt to mix text and data in Python 3.0 raises *note
     TypeError: 198, whereas if you were to mix Unicode and 8-bit
     strings in Python 2.x, it would work if the 8-bit string happened
     to contain only 7-bit (ASCII) bytes, but you would get *note
     UnicodeDecodeError: c0a. if it contained non-ASCII values.  This
     value-specific behavior has caused numerous sad faces over the
     years.

   * As a consequence of this change in philosophy, pretty much all code
     that uses Unicode, encodings or binary data most likely has to
     change.  The change is for the better, as in the 2.x world there
     were numerous bugs having to do with mixing encoded and unencoded
     text.  To be prepared in Python 2.x, start using ‘unicode’ for all
     unencoded text, and *note str: 169. for binary or encoded data
     only.  Then the ‘2to3’ tool will do most of the work for you.

   * You can no longer use ‘u"..."’ literals for Unicode text.  However,
     you must use ‘b"..."’ literals for binary data.

   * As the *note str: 169. and *note bytes: 192. types cannot be mixed,
     you must always explicitly convert between them.  Use *note
     str.encode(): ad4. to go from *note str: 169. to *note bytes: 192,
     and *note bytes.decode(): ad5. to go from *note bytes: 192. to
     *note str: 169.  You can also use ‘bytes(s, encoding=...)’ and
     ‘str(b, encoding=...)’, respectively.

   * Like *note str: 169, the *note bytes: 192. type is immutable.
     There is a separate 'mutable' type to hold buffered binary data,
     *note bytearray: 344.  Nearly all APIs that accept *note bytes:
     192. also accept *note bytearray: 344.  The mutable API is based on
     *note collections.MutableSequence: 4c0.

   * All backslashes in raw string literals are interpreted literally.
     This means that ‘'\U'’ and ‘'\u'’ escapes in raw strings are not
     treated specially.  For example, ‘r'\u20ac'’ is a string of 6
     characters in Python 3.0, whereas in 2.6, ‘ur'\u20ac'’ was the
     single «euro» character.  (Of course, this change only affects raw
     string literals; the euro character is ‘'\u20ac'’ in Python 3.0.)

   * The built-in ‘basestring’ abstract type was removed.  Use *note
     str: 169. instead.  The *note str: 169. and *note bytes: 192. types
     don’t have functionality enough in common to warrant a shared base
     class.  The ‘2to3’ tool (see below) replaces every occurrence of
     ‘basestring’ with *note str: 169.

   * Files opened as text files (still the default mode for *note
     open(): 316.) always use an encoding to map between strings (in
     memory) and bytes (on disk).  Binary files (opened with a ‘b’ in
     the mode argument) always use bytes in memory.  This means that if
     a file is opened using an incorrect mode or encoding, I/O will
     likely fail loudly, instead of silently producing incorrect data.
     It also means that even Unix users will have to specify the correct
     mode (text or binary) when opening a file.  There is a
     platform-dependent default encoding, which on Unixy platforms can
     be set with the ‘LANG’ environment variable (and sometimes also
     with some other platform-specific locale-related environment
     variables).  In many cases, but not all, the system default is
     UTF-8; you should never count on this default.  Any application
     reading or writing more than pure ASCII text should probably have a
     way to override the encoding.  There is no longer any need for
     using the encoding-aware streams in the *note codecs: 1c. module.

   * The initial values of *note sys.stdin: 760, *note sys.stdout: ccf.
     and *note sys.stderr: b35. are now unicode-only text files (i.e.,
     they are instances of *note io.TextIOBase: 8a5.).  To read and
     write bytes data with these streams, you need to use their *note
     io.TextIOBase.buffer: 14ab. attribute.

   * Filenames are passed to and returned from APIs as (Unicode)
     strings.  This can present platform-specific problems because on
     some platforms filenames are arbitrary byte strings.  (On the other
     hand, on Windows filenames are natively stored as Unicode.)  As a
     work-around, most APIs (e.g.  *note open(): 316. and many functions
     in the *note os: a5. module) that take filenames accept *note
     bytes: 192. objects as well as strings, and a few APIs have a way
     to ask for a *note bytes: 192. return value.  Thus, *note
     os.listdir(): 1302. returns a list of *note bytes: 192. instances
     if the argument is a *note bytes: 192. instance, and *note
     os.getcwdb(): c84. returns the current working directory as a *note
     bytes: 192. instance.  Note that when *note os.listdir(): 1302.
     returns a list of strings, filenames that cannot be decoded
     properly are omitted rather than raising *note UnicodeError: 462.

   * Some system APIs like *note os.environ: 259. and *note sys.argv:
     146c. can also present problems when the bytes made available by
     the system is not interpretable using the default encoding.
     Setting the ‘LANG’ variable and rerunning the program is probably
     the best approach.

   * PEP 3138(1): The *note repr(): 1c1. of a string no longer escapes
     non-ASCII characters.  It still escapes control characters and code
     points with non-printable status in the Unicode standard, however.

   * PEP 3120(2): The default source encoding is now UTF-8.

   * PEP 3131(3): Non-ASCII letters are now allowed in identifiers.
     (However, the standard library remains ASCII-only with the
     exception of contributor names in comments.)

   * The ‘StringIO’ and ‘cStringIO’ modules are gone.  Instead, import
     the *note io: 83. module and use *note io.StringIO: 112b. or *note
     io.BytesIO: 10a6. for text and data respectively.

   * See also the *note Unicode HOWTO: 14ac, which was updated for
     Python 3.0.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3138/

   (2) https://peps.python.org/pep-3120/

   (3) https://peps.python.org/pep-3131/


File: python.info,  Node: Overview Of Syntax Changes,  Next: Changes Already Present In Python 2 6,  Prev: Common Stumbling Blocks,  Up: What’s New In Python 3 0

1.15.2 Overview Of Syntax Changes
---------------------------------

This section gives a brief overview of every 'syntactic' change in
Python 3.0.

* Menu:

* New Syntax::
* Changed Syntax::
* Removed Syntax::


File: python.info,  Node: New Syntax,  Next: Changed Syntax,  Up: Overview Of Syntax Changes

1.15.2.1 New Syntax
...................

   * PEP 3107(1): Function argument and return value annotations.  This
     provides a standardized way of annotating a function’s parameters
     and return value.  There are no semantics attached to such
     annotations except that they can be introspected at runtime using
     the *note __annotations__: 458. attribute.  The intent is to
     encourage experimentation through metaclasses, decorators or
     frameworks.

   * PEP 3102(2): Keyword-only arguments.  Named parameters occurring
     after ‘*args’ in the parameter list 'must' be specified using
     keyword syntax in the call.  You can also use a bare ‘*’ in the
     parameter list to indicate that you don’t accept a variable-length
     argument list, but you do have keyword-only arguments.

   * Keyword arguments are allowed after the list of base classes in a
     class definition.  This is used by the new convention for
     specifying a metaclass (see next section), but can be used for
     other purposes as well, as long as the metaclass supports it.

   * PEP 3104(3): *note nonlocal: 14af. statement.  Using ‘nonlocal x’
     you can now assign directly to a variable in an outer (but
     non-global) scope.  ‘nonlocal’ is a new reserved word.

   * PEP 3132(4): Extended Iterable Unpacking.  You can now write things
     like ‘a, b, *rest = some_sequence’.  And even ‘*rest, a = stuff’.
     The ‘rest’ object is always a (possibly empty) list; the right-hand
     side may be any iterable.  Example:

          (a, *rest, b) = range(5)

     This sets 'a' to ‘0’, 'b' to ‘4’, and 'rest' to ‘[1, 2, 3]’.

   * Dictionary comprehensions: ‘{k: v for k, v in stuff}’ means the
     same thing as ‘dict(stuff)’ but is more flexible.  (This is PEP
     274(5) vindicated.  :-)

   * Set literals, e.g.  ‘{1, 2}’.  Note that ‘{}’ is an empty
     dictionary; use ‘set()’ for an empty set.  Set comprehensions are
     also supported; e.g., ‘{x for x in stuff}’ means the same thing as
     ‘set(stuff)’ but is more flexible.

   * New octal literals, e.g.  ‘0o720’ (already in 2.6).  The old octal
     literals (‘0720’) are gone.

   * New binary literals, e.g.  ‘0b1010’ (already in 2.6), and there is
     a new corresponding built-in function, *note bin(): 14b0.

   * Bytes literals are introduced with a leading ‘b’ or ‘B’, and there
     is a new corresponding built-in function, *note bytes(): 192.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3107/

   (2) https://peps.python.org/pep-3102/

   (3) https://peps.python.org/pep-3104/

   (4) https://peps.python.org/pep-3132/

   (5) https://peps.python.org/pep-0274/


File: python.info,  Node: Changed Syntax,  Next: Removed Syntax,  Prev: New Syntax,  Up: Overview Of Syntax Changes

1.15.2.2 Changed Syntax
.......................

   * PEP 3109(1) and PEP 3134(2): new *note raise: 804. statement
     syntax: ‘raise [EXPR [from EXPR]]’.  See below.

   * ‘as’ and *note with: 186. are now reserved words.  (Since 2.6,
     actually.)

   * ‘True’, ‘False’, and ‘None’ are reserved words.  (2.6 partially
     enforced the restrictions on ‘None’ already.)

   * Change from *note except: 1ab. 'exc', 'var' to ‘except’ 'exc' ‘as’
     'var'.  See PEP 3110(3).

   * PEP 3115(4): New Metaclass Syntax.  Instead of:

          class C:
              __metaclass__ = M
              ...

     you must now use:

          class C(metaclass=M):
              ...

     The module-global ‘__metaclass__’ variable is no longer supported.
     (It was a crutch to make it easier to default to new-style classes
     without deriving every class from *note object: c80.)

   * List comprehensions no longer support the syntactic form ‘[... for
     VAR in ITEM1, ITEM2, ...]’.  Use ‘[... for VAR in (ITEM1, ITEM2,
     ...)]’ instead.  Also note that list comprehensions have different
     semantics: they are closer to syntactic sugar for a generator
     expression inside a *note list(): 24d. constructor, and in
     particular the loop control variables are no longer leaked into the
     surrounding scope.

   * The 'ellipsis' (‘...’) can be used as an atomic expression
     anywhere.  (Previously it was only allowed in slices.)  Also, it
     'must' now be spelled as ‘...’.  (Previously it could also be
     spelled as ‘. . .’, by a mere accident of the grammar.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3109/

   (2) https://peps.python.org/pep-3134/

   (3) https://peps.python.org/pep-3110/

   (4) https://peps.python.org/pep-3115/


File: python.info,  Node: Removed Syntax,  Prev: Changed Syntax,  Up: Overview Of Syntax Changes

1.15.2.3 Removed Syntax
.......................

   * PEP 3113(1): Tuple parameter unpacking removed.  You can no longer
     write ‘def foo(a, (b, c)): ...’.  Use ‘def foo(a, b_c): b, c = b_c’
     instead.

   * Removed backticks (use *note repr(): 1c1. instead).

   * Removed ‘<>’ (use ‘!=’ instead).

   * Removed keyword: *note exec(): 4a3. is no longer a keyword; it
     remains as a function.  (Fortunately the function syntax was also
     accepted in 2.x.)  Also note that *note exec(): 4a3. no longer
     takes a stream argument; instead of ‘exec(f)’ you can use
     ‘exec(f.read())’.

   * Integer literals no longer support a trailing ‘l’ or ‘L’.

   * String literals no longer support a leading ‘u’ or ‘U’.

   * The *note from: 14b3. 'module' *note import: 7f9. ‘*’ syntax is
     only allowed at the module level, no longer inside functions.

   * The only acceptable syntax for relative imports is ‘from .[MODULE]
     import NAME’.  All *note import: 7f9. forms not starting with ‘.’
     are interpreted as absolute imports.  ( PEP 328(2))

   * Classic classes are gone.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3113/

   (2) https://peps.python.org/pep-0328/


File: python.info,  Node: Changes Already Present In Python 2 6,  Next: Library Changes,  Prev: Overview Of Syntax Changes,  Up: What’s New In Python 3 0

1.15.3 Changes Already Present In Python 2.6
--------------------------------------------

Since many users presumably make the jump straight from Python 2.5 to
Python 3.0, this section reminds the reader of new features that were
originally designed for Python 3.0 but that were back-ported to Python
2.6.  The corresponding sections in *note What’s New in Python 2.6:
14b5. should be consulted for longer descriptions.

   * *note PEP 343; The “with” statement: 14b6.  The *note with: 186.
     statement is now a standard feature and no longer needs to be
     imported from the *note __future__: 0.  Also check out *note
     Writing Context Managers: 14b7. and *note The contextlib module:
     14b8.

   * *note PEP 366; Explicit Relative Imports From a Main Module: 14b9.
     This enhances the usefulness of the *note -m: 23c. option when the
     referenced module lives in a package.

   * *note PEP 370; Per-user site-packages Directory: 14ba.

   * *note PEP 371; The multiprocessing Package: 14bb.

   * *note PEP 3101; Advanced String Formatting: 14bc.  Note: the 2.6
     description mentions the *note format(): 199. method for both 8-bit
     and Unicode strings.  In 3.0, only the *note str: 169. type (text
     strings with Unicode support) supports this method; the *note
     bytes: 192. type does not.  The plan is to eventually make this the
     only API for string formatting, and to start deprecating the ‘%’
     operator in Python 3.1.

   * *note PEP 3105; print As a Function: 14bd.  This is now a standard
     feature and no longer needs to be imported from *note __future__:
     0.  More details were given above.

   * *note PEP 3110; Exception-Handling Changes: 14be.  The *note
     except: 1ab. 'exc' ‘as’ 'var' syntax is now standard and ‘except’
     'exc', 'var' is no longer supported.  (Of course, the ‘as’ 'var'
     part is still optional.)

   * *note PEP 3112; Byte Literals: 14bf.  The ‘b"..."’ string literal
     notation (and its variants like ‘b'...'’, ‘b"""..."""’, and
     ‘br"..."’) now produces a literal of type *note bytes: 192.

   * *note PEP 3116; New I/O Library: 14c0.  The *note io: 83. module is
     now the standard way of doing file I/O. The built-in *note open():
     316. function is now an alias for *note io.open(): 741. and has
     additional keyword arguments 'encoding', 'errors', 'newline' and
     'closefd'.  Also note that an invalid 'mode' argument now raises
     *note ValueError: 2ec, not *note IOError: 1255.  The binary file
     object underlying a text file object can be accessed as ‘f.buffer’
     (but beware that the text object maintains a buffer of itself in
     order to speed up the encoding and decoding operations).

   * *note PEP 3118; Revised Buffer Protocol: 14c1.  The old builtin
     ‘buffer()’ is now really gone; the new builtin *note memoryview():
     165. provides (mostly) similar functionality.

   * *note PEP 3119; Abstract Base Classes: 14c2.  The *note abc: 4.
     module and the ABCs defined in the *note collections: 1e. module
     plays a somewhat more prominent role in the language now, and
     built-in collection types like *note dict: 183. and *note list:
     24d. conform to the *note collections.MutableMapping: 12b4. and
     *note collections.MutableSequence: 4c0. ABCs, respectively.

   * *note PEP 3127; Integer Literal Support and Syntax: 14c3.  As
     mentioned above, the new octal literal notation is the only one
     supported, and binary literals have been added.

   * *note PEP 3129; Class Decorators: 14c4.

   * *note PEP 3141; A Type Hierarchy for Numbers: 14c5.  The *note
     numbers: a2. module is another new use of ABCs, defining Python’s
     «numeric tower».  Also note the new *note fractions: 61. module
     which implements *note numbers.Rational: 14c6.


File: python.info,  Node: Library Changes,  Next: PEP 3101 A New Approach To String Formatting,  Prev: Changes Already Present In Python 2 6,  Up: What’s New In Python 3 0

1.15.4 Library Changes
----------------------

Due to time constraints, this document does not exhaustively cover the
very extensive changes to the standard library.  PEP 3108(1) is the
reference for the major changes to the library.  Here’s a capsule
review:

   * Many old modules were removed.  Some, like ‘gopherlib’ (no longer
     used) and ‘md5’ (replaced by *note hashlib: 6c.), were already
     deprecated by PEP 4(2).  Others were removed as a result of the
     removal of support for various platforms such as Irix, BeOS and Mac
     OS 9 (see PEP 11(3)).  Some modules were also selected for removal
     in Python 3.0 due to lack of use or because a better replacement
     exists.  See PEP 3108(4) for an exhaustive list.

   * The ‘bsddb3’ package was removed because its presence in the core
     standard library has proved over time to be a particular burden for
     the core developers due to testing instability and Berkeley DB’s
     release schedule.  However, the package is alive and well,
     externally maintained at
     ‘https://www.jcea.es/programacion/pybsddb.htm’.

   * Some modules were renamed because their old name disobeyed PEP
     8(5), or for various other reasons.  Here’s the list:

     Old Name                    New Name
                                 
     --------------------------------------------------------
                                 
     _winreg                     winreg
                                 
                                 
     ConfigParser                configparser
                                 
                                 
     copy_reg                    copyreg
                                 
                                 
     Queue                       queue
                                 
                                 
     SocketServer                socketserver
                                 
                                 
     markupbase                  _markupbase
                                 
                                 
     repr                        reprlib
                                 
                                 
     test.test_support           test.support
                                 

   * A common pattern in Python 2.x is to have one version of a module
     implemented in pure Python, with an optional accelerated version
     implemented as a C extension; for example, *note pickle: ab. and
     ‘cPickle’.  This places the burden of importing the accelerated
     version and falling back on the pure Python version on each user of
     these modules.  In Python 3.0, the accelerated versions are
     considered implementation details of the pure Python versions.
     Users should always import the standard version, which attempts to
     import the accelerated version and falls back to the pure Python
     version.  The *note pickle: ab. / ‘cPickle’ pair received this
     treatment.  The *note profile: b4. module is on the list for 3.1.
     The ‘StringIO’ module has been turned into a class in the *note io:
     83. module.

   * Some related modules have been grouped into packages, and usually
     the submodule names have been simplified.  The resulting new
     packages are:

        * *note dbm: 35. (‘anydbm’, ‘dbhash’, ‘dbm’, ‘dumbdbm’, ‘gdbm’,
          ‘whichdb’).

        * *note html: 6f. (‘HTMLParser’, ‘htmlentitydefs’).

        * *note http: 72. (‘httplib’, ‘BaseHTTPServer’, ‘CGIHTTPServer’,
          ‘SimpleHTTPServer’, ‘Cookie’, ‘cookielib’).

        * *note tkinter: f6. (all ‘Tkinter’-related modules except *note
          turtle: 107.).  The target audience of *note turtle: 107.
          doesn’t really care about *note tkinter: f6.  Also note that
          as of Python 2.6, the functionality of *note turtle: 107. has
          been greatly enhanced.

        * *note urllib: 10e. (‘urllib’, ‘urllib2’, ‘urlparse’,
          ‘robotparse’).

        * *note xmlrpc: 133. (‘xmlrpclib’, ‘DocXMLRPCServer’,
          ‘SimpleXMLRPCServer’).

Some other changes to standard library modules, not covered by PEP
3108(6):

   * Killed ‘sets’.  Use the built-in *note set(): 184. class.

   * Cleanup of the *note sys: df. module: removed ‘sys.exitfunc()’,
     ‘sys.exc_clear()’, ‘sys.exc_type’, ‘sys.exc_value’,
     ‘sys.exc_traceback’.  (Note that *note sys.last_type: 6e7. etc.
     remain.)

   * Cleanup of the *note array.array: 4bf. type: the ‘read()’ and
     ‘write()’ methods are gone; use *note fromfile(): 14c8. and *note
     tofile(): 14c9. instead.  Also, the ‘'c'’ typecode for array is
     gone – use either ‘'b'’ for bytes or ‘'u'’ for Unicode characters.

   * Cleanup of the *note operator: a3. module: removed
     ‘sequenceIncludes()’ and ‘isCallable()’.

   * Cleanup of the ‘thread’ module: ‘acquire_lock()’ and
     ‘release_lock()’ are gone; use *note acquire(): 8a8. and *note
     release(): 14ca. instead.

   * Cleanup of the *note random: bd. module: removed the ‘jumpahead()’
     API.

   * The ‘new’ module is gone.

   * The functions ‘os.tmpnam()’, ‘os.tempnam()’ and ‘os.tmpfile()’ have
     been removed in favor of the *note tempfile: e6. module.

   * The *note tokenize: 101. module has been changed to work with
     bytes.  The main entry point is now *note tokenize.tokenize(): 701,
     instead of generate_tokens.

   * ‘string.letters’ and its friends (‘string.lowercase’ and
     ‘string.uppercase’) are gone.  Use *note string.ascii_letters:
     14cb. etc.  instead.  (The reason for the removal is that
     ‘string.letters’ and friends had locale-specific behavior, which is
     a bad idea for such attractively named global «constants».)

   * Renamed module ‘__builtin__’ to *note builtins: 13. (removing the
     underscores, adding an “s”).  The ‘__builtins__’ variable found in
     most global namespaces is unchanged.  To modify a builtin, you
     should use *note builtins: 13, not ‘__builtins__’!

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3108/

   (2) https://peps.python.org/pep-0004/

   (3) https://peps.python.org/pep-0011/

   (4) https://peps.python.org/pep-3108/

   (5) https://peps.python.org/pep-0008/

   (6) https://peps.python.org/pep-3108/


File: python.info,  Node: PEP 3101 A New Approach To String Formatting,  Next: Changes To Exceptions,  Prev: Library Changes,  Up: What’s New In Python 3 0

'PEP 3101': A New Approach To String Formatting

   * A new system for built-in string formatting operations replaces the
     ‘%’ string formatting operator.  (However, the ‘%’ operator is
     still supported; it will be deprecated in Python 3.1 and removed
     from the language at some later time.)  Read PEP 3101(1) for the
     full scoop.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3101/


File: python.info,  Node: Changes To Exceptions,  Next: Miscellaneous Other Changes,  Prev: PEP 3101 A New Approach To String Formatting,  Up: What’s New In Python 3 0

1.15.6 Changes To Exceptions
----------------------------

The APIs for raising and catching exception have been cleaned up and new
powerful features added:

   * PEP 352(1): All exceptions must be derived (directly or indirectly)
     from *note BaseException: 7d8.  This is the root of the exception
     hierarchy.  This is not new as a recommendation, but the
     'requirement' to inherit from *note BaseException: 7d8. is new.
     (Python 2.6 still allowed classic classes to be raised, and placed
     no restriction on what you can catch.)  As a consequence, string
     exceptions are finally truly and utterly dead.

   * Almost all exceptions should actually derive from *note Exception:
     bcf.; *note BaseException: 7d8. should only be used as a base class
     for exceptions that should only be handled at the top level, such
     as *note SystemExit: f3e. or *note KeyboardInterrupt: bc7.  The
     recommended idiom for handling all exceptions except for this
     latter category is to use *note except: 1ab. *note Exception: bcf.

   * ‘StandardError’ was removed.

   * Exceptions no longer behave as sequences.  Use the *note args: 78e.
     attribute instead.

   * PEP 3109(2): Raising exceptions.  You must now use ‘raise
     EXCEPTION(ARGS)’ instead of ‘raise EXCEPTION, ARGS’.  Additionally,
     you can no longer explicitly specify a traceback; instead, if you
     'have' to do this, you can assign directly to the *note
     __traceback__: 14ce. attribute (see below).

   * PEP 3110(3): Catching exceptions.  You must now use ‘except
     SOMEEXCEPTION as VARIABLE’ instead of ‘except SOMEEXCEPTION,
     VARIABLE’.  Moreover, the 'variable' is explicitly deleted when the
     *note except: 1ab. block is left.

   * PEP 3134(4): Exception chaining.  There are two cases: implicit
     chaining and explicit chaining.  Implicit chaining happens when an
     exception is raised in an *note except: 1ab. or *note finally: 1b0.
     handler block.  This usually happens due to a bug in the handler
     block; we call this a 'secondary' exception.  In this case, the
     original exception (that was being handled) is saved as the *note
     __context__: 14cf. attribute of the secondary exception.  Explicit
     chaining is invoked with this syntax:

          raise SecondaryException() from primary_exception

     (where 'primary_exception' is any expression that produces an
     exception object, probably an exception that was previously
     caught).  In this case, the primary exception is stored on the
     *note __cause__: 14d0. attribute of the secondary exception.  The
     traceback printed when an unhandled exception occurs walks the
     chain of ‘__cause__’ and *note __context__: 14cf. attributes and
     prints a separate traceback for each component of the chain, with
     the primary exception at the top.  (Java users may recognize this
     behavior.)

   * PEP 3134(5): Exception objects now store their traceback as the
     *note __traceback__: 14ce. attribute.  This means that an exception
     object now contains all the information pertaining to an exception,
     and there are fewer reasons to use *note sys.exc_info(): 89b.
     (though the latter is not removed).

   * A few exception messages are improved when Windows fails to load an
     extension module.  For example, ‘error code 193’ is now ‘%1 is not
     a valid Win32 application’.  Strings now deal with non-English
     locales.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0352/

   (2) https://peps.python.org/pep-3109/

   (3) https://peps.python.org/pep-3110/

   (4) https://peps.python.org/pep-3134/

   (5) https://peps.python.org/pep-3134/


File: python.info,  Node: Miscellaneous Other Changes,  Next: Build and C API Changes<7>,  Prev: Changes To Exceptions,  Up: What’s New In Python 3 0

1.15.7 Miscellaneous Other Changes
----------------------------------

* Menu:

* Operators And Special Methods::
* Builtins::


File: python.info,  Node: Operators And Special Methods,  Next: Builtins,  Up: Miscellaneous Other Changes

1.15.7.1 Operators And Special Methods
......................................

   * ‘!=’ now returns the opposite of ‘==’, unless ‘==’ returns *note
     NotImplemented: 1a2.

   * The concept of «unbound methods» has been removed from the
     language.  When referencing a method as a class attribute, you now
     get a plain function object.

   * ‘__getslice__()’, ‘__setslice__()’ and ‘__delslice__()’ were
     killed.  The syntax ‘a[i:j]’ now translates to
     ‘a.__getitem__(slice(i, j))’ (or *note __setitem__(): 14d3. or
     *note __delitem__(): 14d4, when used as an assignment or deletion
     target, respectively).

   * PEP 3114(1): the standard *note next(): 9da. method has been
     renamed to *note __next__(): 14d5.

   * The ‘__oct__()’ and ‘__hex__()’ special methods are removed – *note
     oct(): 14d6. and *note hex(): 14d7. use *note __index__(): 19e. now
     to convert the argument to an integer.

   * Removed support for ‘__members__’ and ‘__methods__’.

   * The function attributes named ‘func_X’ have been renamed to use the
     ‘__X__’ form, freeing up these names in the function attribute
     namespace for user-defined attributes.  To wit, ‘func_closure’,
     ‘func_code’, ‘func_defaults’, ‘func_dict’, ‘func_doc’,
     ‘func_globals’, ‘func_name’ were renamed to *note __closure__:
     14d8, *note __code__: 59d, *note __defaults__: 14d9, *note
     __dict__: 14da, *note __doc__: 13e1, *note __globals__: 14db, *note
     __name__: 14dc, respectively.

   * ‘__nonzero__()’ is now *note __bool__(): 14dd.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3114/


File: python.info,  Node: Builtins,  Prev: Operators And Special Methods,  Up: Miscellaneous Other Changes

1.15.7.2 Builtins
.................

   * PEP 3135(1): New *note super(): 1a6.  You can now invoke *note
     super(): 1a6. without arguments and (assuming this is in a regular
     instance method defined inside a *note class: 14df. statement) the
     right class and instance will automatically be chosen.  With
     arguments, the behavior of *note super(): 1a6. is unchanged.

   * PEP 3111(2): ‘raw_input()’ was renamed to *note input(): 14e0.
     That is, the new *note input(): 14e0. function reads a line from
     *note sys.stdin: 760. and returns it with the trailing newline
     stripped.  It raises *note EOFError: 14e1. if the input is
     terminated prematurely.  To get the old behavior of *note input():
     14e0, use ‘eval(input())’.

   * A new built-in function *note next(): 9da. was added to call the
     *note __next__(): 14d5. method on an object.

   * The *note round(): 14e2. function rounding strategy and return type
     have changed.  Exact halfway cases are now rounded to the nearest
     even result instead of away from zero.  (For example, ‘round(2.5)’
     now returns ‘2’ rather than ‘3’.)  ‘round(x[, n])’ now delegates to
     ‘x.__round__([n])’ instead of always returning a float.  It
     generally returns an integer when called with a single argument and
     a value of the same type as ‘x’ when called with two arguments.

   * Moved ‘intern()’ to *note sys.intern(): 14e3.

   * Removed: ‘apply()’.  Instead of ‘apply(f, args)’ use ‘f(*args)’.

   * Removed *note callable(): 13ce.  Instead of ‘callable(f)’ you can
     use ‘isinstance(f, collections.Callable)’.  The
     ‘operator.isCallable()’ function is also gone.

   * Removed ‘coerce()’.  This function no longer serves a purpose now
     that classic classes are gone.

   * Removed ‘execfile()’.  Instead of ‘execfile(fn)’ use
     ‘exec(open(fn).read())’.

   * Removed the ‘file’ type.  Use *note open(): 316.  There are now
     several different kinds of streams that open can return in the
     *note io: 83. module.

   * Removed ‘reduce()’.  Use *note functools.reduce(): 21a. if you
     really need it; however, 99 percent of the time an explicit *note
     for: 34a. loop is more readable.

   * Removed ‘reload()’.  Use ‘imp.reload()’.

   * Removed.  ‘dict.has_key()’ – use the *note in: 34b. operator
     instead.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3135/

   (2) https://peps.python.org/pep-3111/


File: python.info,  Node: Build and C API Changes<7>,  Next: Performance,  Prev: Miscellaneous Other Changes,  Up: What’s New In Python 3 0

1.15.8 Build and C API Changes
------------------------------

Due to time constraints, here is a 'very' incomplete list of changes to
the C API.

   * Support for several platforms was dropped, including but not
     limited to Mac OS 9, BeOS, RISCOS, Irix, and Tru64.

   * PEP 3118(1): New Buffer API.

   * PEP 3121(2): Extension Module Initialization & Finalization.

   * PEP 3123(3): Making *note PyObject_HEAD: 14e5. conform to standard
     C.

   * No more C API support for restricted execution.

   * ‘PyNumber_Coerce()’, ‘PyNumber_CoerceEx()’, ‘PyMember_Get()’, and
     ‘PyMember_Set()’ C APIs are removed.

   * New C API *note PyImport_ImportModuleNoBlock(): 3db, works like
     *note PyImport_ImportModule(): 3dc. but won’t block on the import
     lock (returning an error instead).

   * Renamed the boolean conversion C-level slot and method:
     ‘nb_nonzero’ is now ‘nb_bool’.

   * Removed ‘METH_OLDARGS’ and ‘WITH_CYCLE_GC’ from the C API.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3118/

   (2) https://peps.python.org/pep-3121/

   (3) https://peps.python.org/pep-3123/


File: python.info,  Node: Performance,  Next: Porting To Python 3 0,  Prev: Build and C API Changes<7>,  Up: What’s New In Python 3 0

1.15.9 Performance
------------------

The net result of the 3.0 generalizations is that Python 3.0 runs the
pystone benchmark around 10% slower than Python 2.5.  Most likely the
biggest cause is the removal of special-casing for small integers.
There’s room for improvement, but it will happen after 3.0 is released!


File: python.info,  Node: Porting To Python 3 0,  Prev: Performance,  Up: What’s New In Python 3 0

1.15.10 Porting To Python 3.0
-----------------------------

For porting existing Python 2.5 or 2.6 source code to Python 3.0, the
best strategy is the following:

  0. (Prerequisite:) Start with excellent test coverage.

  1. Port to Python 2.6.  This should be no more work than the average
     port from Python 2.x to Python 2.(x+1).  Make sure all your tests
     pass.

  2. (Still using 2.6:) Turn on the ‘-3’ command line switch.  This
     enables warnings about features that will be removed (or change) in
     3.0.  Run your test suite again, and fix code that you get warnings
     about until there are no warnings left, and all your tests still
     pass.

  3. Run the ‘2to3’ source-to-source translator over your source code
     tree.  Run the result of the translation under Python 3.0.
     Manually fix up any remaining issues, fixing problems until all
     tests pass again.

It is not recommended to try to write source code that runs unchanged
under both Python 2.6 and 3.0; you’d have to use a very contorted coding
style, e.g.  avoiding ‘print’ statements, metaclasses, and much more.
If you are maintaining a library that needs to support both Python 2.6
and Python 3.0, the best approach is to modify step 3 above by editing
the 2.6 version of the source code and running the ‘2to3’ translator
again, rather than editing the 3.0 version of the source code.

For porting C extensions to Python 3.0, please see *note Porting
Extension Modules to Python 3: 14e8.


File: python.info,  Node: What’s New in Python 2 7,  Next: What’s New in Python 2 6,  Prev: What’s New In Python 3 0,  Up: Novità in Python

1.16 What’s New in Python 2.7
=============================


Author: A.M. Kuchling (amk at amk.ca)

This article explains the new features in Python 2.7.  Python 2.7 was
released on July 3, 2010.

Numeric handling has been improved in many ways, for both floating-point
numbers and for the *note Decimal: 1fe. class.  There are some useful
additions to the standard library, such as a greatly enhanced *note
unittest: 10c. module, the *note argparse: 7. module for parsing
command-line options, convenient *note OrderedDict: 7f4. and *note
Counter: 1299. classes in the *note collections: 1e. module, and many
other improvements.

Python 2.7 is planned to be the last of the 2.x releases, so we worked
on making it a good release for the long term.  To help with porting to
Python 3, several new features from the Python 3.x series have been
included in 2.7.

This article doesn’t attempt to provide a complete specification of the
new features, but instead provides a convenient overview.  For full
details, you should refer to the documentation for Python 2.7 at
‘https://docs.python.org’.  If you want to understand the rationale for
the design and implementation, refer to the PEP for a particular new
feature or the issue on ‘https://bugs.python.org’ in which a change was
discussed.  Whenever possible, «What’s New in Python» links to the
bug/patch item for each change.

* Menu:

* The Future for Python 2.x: The Future for Python 2 x.
* Changes to the Handling of Deprecation Warnings::
* Python 3.1 Features: Python 3 1 Features.
* PEP 372; Adding an Ordered Dictionary to collections: PEP 372 Adding an Ordered Dictionary to collections.
* PEP 378; Format Specifier for Thousands Separator: PEP 378 Format Specifier for Thousands Separator<2>.
* PEP 389; The argparse Module for Parsing Command Lines: PEP 389 The argparse Module for Parsing Command Lines.
* PEP 391; Dictionary-Based Configuration For Logging: PEP 391 Dictionary-Based Configuration For Logging.
* PEP 3106; Dictionary Views: PEP 3106 Dictionary Views.
* PEP 3137; The memoryview Object: PEP 3137 The memoryview Object.
* Other Language Changes: Other Language Changes<13>.
* New and Improved Modules::
* Build and C API Changes: Build and C API Changes<8>.
* Other Changes and Fixes::
* Porting to Python 2.7: Porting to Python 2 7.
* New Features Added to Python 2.7 Maintenance Releases: New Features Added to Python 2 7 Maintenance Releases.
* Acknowledgements::


File: python.info,  Node: The Future for Python 2 x,  Next: Changes to the Handling of Deprecation Warnings,  Up: What’s New in Python 2 7

1.16.1 The Future for Python 2.x
--------------------------------

Python 2.7 is the last major release in the 2.x series, as the Python
maintainers have shifted the focus of their new feature development
efforts to the Python 3.x series.  This means that while Python 2
continues to receive bug fixes, and to be updated to build correctly on
new hardware and versions of supported operated systems, there will be
no new full feature releases for the language or standard library.

However, while there is a large common subset between Python 2.7 and
Python 3, and many of the changes involved in migrating to that common
subset, or directly to Python 3, can be safely automated, some other
changes (notably those associated with Unicode handling) may require
careful consideration, and preferably robust automated regression test
suites, to migrate effectively.

This means that Python 2.7 will remain in place for a long time,
providing a stable and supported base platform for production systems
that have not yet been ported to Python 3.  The full expected lifecycle
of the Python 2.7 series is detailed in PEP 373(1).

Some key consequences of the long-term significance of 2.7 are:

   * As noted above, the 2.7 release has a much longer period of
     maintenance when compared to earlier 2.x versions.  Python 2.7 is
     currently expected to remain supported by the core development team
     (receiving security updates and other bug fixes) until at least
     2020 (10 years after its initial release, compared to the more
     typical support period of 18–24 months).

   * As the Python 2.7 standard library ages, making effective use of
     the Python Package Index (either directly or via a redistributor)
     becomes more important for Python 2 users.  In addition to a wide
     variety of third party packages for various tasks, the available
     packages include backports of new modules and features from the
     Python 3 standard library that are compatible with Python 2, as
     well as various tools and libraries that can make it easier to
     migrate to Python 3.  The Python Packaging User Guide(2) provides
     guidance on downloading and installing software from the Python
     Package Index.

   * While the preferred approach to enhancing Python 2 is now the
     publication of new packages on the Python Package Index, this
     approach doesn’t necessarily work in all cases, especially those
     related to network security.  In exceptional cases that cannot be
     handled adequately by publishing new or updated packages on PyPI,
     the Python Enhancement Proposal process may be used to make the
     case for adding new features directly to the Python 2 standard
     library.  Any such additions, and the maintenance releases where
     they were added, will be noted in the *note New Features Added to
     Python 2.7 Maintenance Releases: 14ee. section below.

For projects wishing to migrate from Python 2 to Python 3, or for
library and framework developers wishing to support users on both Python
2 and Python 3, there are a variety of tools and guides available to
help decide on a suitable approach and manage some of the technical
details involved.  The recommended starting point is the pyporting-howto
HOWTO guide.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0373/

   (2) https://packaging.python.org


File: python.info,  Node: Changes to the Handling of Deprecation Warnings,  Next: Python 3 1 Features,  Prev: The Future for Python 2 x,  Up: What’s New in Python 2 7

1.16.2 Changes to the Handling of Deprecation Warnings
------------------------------------------------------

For Python 2.7, a policy decision was made to silence warnings only of
interest to developers by default.  *note DeprecationWarning: 1a3. and
its descendants are now ignored unless otherwise requested, preventing
users from seeing warnings triggered by an application.  This change was
also made in the branch that became Python 3.2.  (Discussed on
stdlib-sig and carried out in bpo-7319(1).)

In previous releases, *note DeprecationWarning: 1a3. messages were
enabled by default, providing Python developers with a clear indication
of where their code may break in a future major version of Python.

However, there are increasingly many users of Python-based applications
who are not directly involved in the development of those applications.
*note DeprecationWarning: 1a3. messages are irrelevant to such users,
making them worry about an application that’s actually working correctly
and burdening application developers with responding to these concerns.

You can re-enable display of *note DeprecationWarning: 1a3. messages by
running Python with the *note -Wdefault: ac7. (short form: *note -Wd:
ac7.) switch, or by setting the *note PYTHONWARNINGS: da5. environment
variable to ‘"default"’ (or ‘"d"’) before running Python.  Python code
can also re-enable them by calling ‘warnings.simplefilter('default')’.

The ‘unittest’ module also automatically reenables deprecation warnings
when running tests.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=7319


File: python.info,  Node: Python 3 1 Features,  Next: PEP 372 Adding an Ordered Dictionary to collections,  Prev: Changes to the Handling of Deprecation Warnings,  Up: What’s New in Python 2 7

1.16.3 Python 3.1 Features
--------------------------

Much as Python 2.6 incorporated features from Python 3.0, version 2.7
incorporates some of the new features in Python 3.1.  The 2.x series
continues to provide tools for migrating to the 3.x series.

A partial list of 3.1 features that were backported to 2.7:

   * The syntax for set literals (‘{1,2,3}’ is a mutable set).

   * Dictionary and set comprehensions (‘{i: i*2 for i in range(3)}’).

   * Multiple context managers in a single *note with: 186. statement.

   * A new version of the *note io: 83. library, rewritten in C for
     performance.

   * The ordered-dictionary type described in *note PEP 372; Adding an
     Ordered Dictionary to collections: 14f1.

   * The new ‘","’ format specifier described in *note PEP 378; Format
     Specifier for Thousands Separator: 14f2.

   * The *note memoryview: 165. object.

   * A small subset of the *note importlib: 7b. module, *note described
     below: 14f3.

   * The *note repr(): 1c1. of a float ‘x’ is shorter in many cases:
     it’s now based on the shortest decimal string that’s guaranteed to
     round back to ‘x’.  As in previous versions of Python, it’s
     guaranteed that ‘float(repr(x))’ recovers ‘x’.

   * Float-to-string and string-to-float conversions are correctly
     rounded.  The *note round(): 14e2. function is also now correctly
     rounded.

   * The *note PyCapsule: 147a. type, used to provide a C API for
     extension modules.

   * The *note PyLong_AsLongAndOverflow(): 146e. C API function.

Other new Python3-mode warnings include:

   * ‘operator.isCallable()’ and ‘operator.sequenceIncludes()’, which
     are not supported in 3.x, now trigger warnings.

   * The ‘-3’ switch now automatically enables the ‘-Qwarn’ switch that
     causes warnings about using classic division with integers and long
     integers.


File: python.info,  Node: PEP 372 Adding an Ordered Dictionary to collections,  Next: PEP 378 Format Specifier for Thousands Separator<2>,  Prev: Python 3 1 Features,  Up: What’s New in Python 2 7

1.16.4 PEP 372: Adding an Ordered Dictionary to collections
-----------------------------------------------------------

Regular Python dictionaries iterate over key/value pairs in arbitrary
order.  Over the years, a number of authors have written alternative
implementations that remember the order that the keys were originally
inserted.  Based on the experiences from those implementations, 2.7
introduces a new *note OrderedDict: 7f4. class in the *note collections:
1e. module.

The *note OrderedDict: 7f4. API provides the same interface as regular
dictionaries but iterates over keys and values in a guaranteed order
depending on when a key was first inserted:

     >>> from collections import OrderedDict
     >>> d = OrderedDict([('first', 1),
     ...                  ('second', 2),
     ...                  ('third', 3)])
     >>> d.items()
     [('first', 1), ('second', 2), ('third', 3)]

If a new entry overwrites an existing entry, the original insertion
position is left unchanged:

     >>> d['second'] = 4
     >>> d.items()
     [('first', 1), ('second', 4), ('third', 3)]

Deleting an entry and reinserting it will move it to the end:

     >>> del d['second']
     >>> d['second'] = 5
     >>> d.items()
     [('first', 1), ('third', 3), ('second', 5)]

The *note popitem(): 14f5. method has an optional 'last' argument that
defaults to ‘True’.  If 'last' is true, the most recently added key is
returned and removed; if it’s false, the oldest key is selected:

     >>> od = OrderedDict([(x,0) for x in range(20)])
     >>> od.popitem()
     (19, 0)
     >>> od.popitem()
     (18, 0)
     >>> od.popitem(last=False)
     (0, 0)
     >>> od.popitem(last=False)
     (1, 0)

Comparing two ordered dictionaries checks both the keys and values, and
requires that the insertion order was the same:

     >>> od1 = OrderedDict([('first', 1),
     ...                    ('second', 2),
     ...                    ('third', 3)])
     >>> od2 = OrderedDict([('third', 3),
     ...                    ('first', 1),
     ...                    ('second', 2)])
     >>> od1 == od2
     False
     >>> # Move 'third' key to the end
     >>> del od2['third']; od2['third'] = 3
     >>> od1 == od2
     True

Comparing an *note OrderedDict: 7f4. with a regular dictionary ignores
the insertion order and just compares the keys and values.

How does the *note OrderedDict: 7f4. work?  It maintains a doubly linked
list of keys, appending new keys to the list as they’re inserted.  A
secondary dictionary maps keys to their corresponding list node, so
deletion doesn’t have to traverse the entire linked list and therefore
remains 'O'(1).

The standard library now supports use of ordered dictionaries in several
modules.

   * The *note ConfigParser: 26. module uses them by default, meaning
     that configuration files can now be read, modified, and then
     written back in their original order.

   * The *note _asdict(): bd6. method for *note
     collections.namedtuple(): 4e1. now returns an ordered dictionary
     with the values appearing in the same order as the underlying tuple
     indices.

   * The *note json: 86. module’s *note JSONDecoder: f45. class
     constructor was extended with an 'object_pairs_hook' parameter to
     allow ‘OrderedDict’ instances to be built by the decoder.  Support
     was also added for third-party tools like PyYAML(1).

Vedi anche
..........

PEP 372(2) - Adding an ordered dictionary to collections

     PEP written by Armin Ronacher and Raymond Hettinger; implemented by
     Raymond Hettinger.

   ---------- Footnotes ----------

   (1) https://pyyaml.org/

   (2) https://peps.python.org/pep-0372/


File: python.info,  Node: PEP 378 Format Specifier for Thousands Separator<2>,  Next: PEP 389 The argparse Module for Parsing Command Lines,  Prev: PEP 372 Adding an Ordered Dictionary to collections,  Up: What’s New in Python 2 7

1.16.5 PEP 378: Format Specifier for Thousands Separator
--------------------------------------------------------

To make program output more readable, it can be useful to add separators
to large numbers, rendering them as 18,446,744,073,709,551,616 instead
of 18446744073709551616.

The fully general solution for doing this is the *note locale: 8a.
module, which can use different separators («,» in North America, «.» in
Europe) and different grouping sizes, but *note locale: 8a. is
complicated to use and unsuitable for multi-threaded applications where
different threads are producing output for different locales.

Therefore, a simple comma-grouping mechanism has been added to the
mini-language used by the *note str.format(): 834. method.  When
formatting a floating-point number, simply include a comma between the
width and the precision:

     >>> '{:20,.2f}'.format(18446744073709551616.0)
     '18,446,744,073,709,551,616.00'

When formatting an integer, include the comma after the width:

     >>> '{:20,d}'.format(18446744073709551616)
     '18,446,744,073,709,551,616'

This mechanism is not adaptable at all; commas are always used as the
separator and the grouping is always into three-digit groups.  The
comma-formatting mechanism isn’t as general as the *note locale: 8a.
module, but it’s easier to use.

Vedi anche
..........

PEP 378(1) - Format Specifier for Thousands Separator

     PEP written by Raymond Hettinger; implemented by Eric Smith.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0378/


File: python.info,  Node: PEP 389 The argparse Module for Parsing Command Lines,  Next: PEP 391 Dictionary-Based Configuration For Logging,  Prev: PEP 378 Format Specifier for Thousands Separator<2>,  Up: What’s New in Python 2 7

1.16.6 PEP 389: The argparse Module for Parsing Command Lines
-------------------------------------------------------------

The *note argparse: 7. module for parsing command-line arguments was
added as a more powerful replacement for the *note optparse: a4. module.

This means Python now supports three different modules for parsing
command-line arguments: *note getopt: 65, *note optparse: a4, and *note
argparse: 7.  The *note getopt: 65. module closely resembles the C
library’s ‘getopt()’ function, so it remains useful if you’re writing a
Python prototype that will eventually be rewritten in C. *note optparse:
a4. becomes redundant, but there are no plans to remove it because there
are many scripts still using it, and there’s no automated way to update
these scripts.  (Making the *note argparse: 7. API consistent with *note
optparse: a4.’s interface was discussed but rejected as too messy and
difficult.)

In short, if you’re writing a new script and don’t need to worry about
compatibility with earlier versions of Python, use *note argparse: 7.
instead of *note optparse: a4.

Here’s an example:

     import argparse

     parser = argparse.ArgumentParser(description='Command-line example.')

     # Add optional switches
     parser.add_argument('-v', action='store_true', dest='is_verbose',
                         help='produce verbose output')
     parser.add_argument('-o', action='store', dest='output',
                         metavar='FILE',
                         help='direct output to FILE instead of stdout')
     parser.add_argument('-C', action='store', type=int, dest='context',
                         metavar='NUM', default=0,
                         help='display NUM lines of added context')

     # Allow any number of additional arguments.
     parser.add_argument(nargs='*', action='store', dest='inputs',
                         help='input filenames (default is stdin)')

     args = parser.parse_args()
     print args.__dict__

Unless you override it, ‘-h’ and ‘--help’ switches are automatically
added, and produce neatly formatted output:

     -> ./python.exe argparse-example.py --help
     usage: argparse-example.py [-h] [-v] [-o FILE] [-C NUM] [inputs [inputs ...]]

     Command-line example.

     positional arguments:
       inputs      input filenames (default is stdin)

     optional arguments:
       -h, --help  show this help message and exit
       -v          produce verbose output
       -o FILE     direct output to FILE instead of stdout
       -C NUM      display NUM lines of added context

As with *note optparse: a4, the command-line switches and arguments are
returned as an object with attributes named by the 'dest' parameters:

     -> ./python.exe argparse-example.py -v
     {'output': None,
      'is_verbose': True,
      'context': 0,
      'inputs': []}

     -> ./python.exe argparse-example.py -v -o /tmp/output -C 4 file1 file2
     {'output': '/tmp/output',
      'is_verbose': True,
      'context': 4,
      'inputs': ['file1', 'file2']}

*note argparse: 7. has much fancier validation than *note optparse: a4.;
you can specify an exact number of arguments as an integer, 0 or more
arguments by passing ‘'*'’, 1 or more by passing ‘'+'’, or an optional
argument with ‘'?'’.  A top-level parser can contain sub-parsers to
define subcommands that have different sets of switches, as in ‘svn
commit’, ‘svn checkout’, etc.  You can specify an argument’s type as
*note FileType: 30c, which will automatically open files for you and
understands that ‘'-'’ means standard input or output.

Vedi anche
..........

*note argparse: 7. documentation

     The documentation page of the argparse module.

*note Migrating optparse code to argparse: 13b6.

     Part of the Python documentation, describing how to convert code
     that uses *note optparse: a4.

PEP 389(1) - argparse - New Command Line Parsing Module

     PEP written and implemented by Steven Bethard.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0389/


File: python.info,  Node: PEP 391 Dictionary-Based Configuration For Logging,  Next: PEP 3106 Dictionary Views,  Prev: PEP 389 The argparse Module for Parsing Command Lines,  Up: What’s New in Python 2 7

1.16.7 PEP 391: Dictionary-Based Configuration For Logging
----------------------------------------------------------

The *note logging: 8b. module is very flexible; applications can define
a tree of logging subsystems, and each logger in this tree can filter
out certain messages, format them differently, and direct messages to a
varying number of handlers.

All this flexibility can require a lot of configuration.  You can write
Python statements to create objects and set their properties, but a
complex set-up requires verbose but boring code.  *note logging: 8b.
also supports a *note fileConfig(): d4a. function that parses a file,
but the file format doesn’t support configuring filters, and it’s
messier to generate programmatically.

Python 2.7 adds a *note dictConfig(): 13b8. function that uses a
dictionary to configure logging.  There are many ways to produce a
dictionary from different sources: construct one with code; parse a file
containing JSON; or use a YAML parsing library if one is installed.  For
more information see *note Configuration functions: 14f9.

The following example configures two loggers, the root logger and a
logger named «network».  Messages sent to the root logger will be sent
to the system log using the syslog protocol, and messages to the
«network» logger will be written to a ‘network.log’ file that will be
rotated once the log reaches 1MB.

     import logging
     import logging.config

     configdict = {
      'version': 1,    # Configuration schema in use; must be 1 for now
      'formatters': {
          'standard': {
              'format': ('%(asctime)s %(name)-15s '
                         '%(levelname)-8s %(message)s')}},

      'handlers': {'netlog': {'backupCount': 10,
                          'class': 'logging.handlers.RotatingFileHandler',
                          'filename': '/logs/network.log',
                          'formatter': 'standard',
                          'level': 'INFO',
                          'maxBytes': 1000000},
                   'syslog': {'class': 'logging.handlers.SysLogHandler',
                              'formatter': 'standard',
                              'level': 'ERROR'}},

      # Specify all the subordinate loggers
      'loggers': {
                  'network': {
                              'handlers': ['netlog']
                  }
      },
      # Specify properties of the root logger
      'root': {
               'handlers': ['syslog']
      },
     }

     # Set up configuration
     logging.config.dictConfig(configdict)

     # As an example, log two error messages
     logger = logging.getLogger('/')
     logger.error('Database not found')

     netlogger = logging.getLogger('network')
     netlogger.error('Connection failed')

Three smaller enhancements to the *note logging: 8b. module, all
implemented by Vinay Sajip, are:

   * The *note SysLogHandler: 86d. class now supports syslogging over
     TCP. The constructor has a 'socktype' parameter giving the type of
     socket to use, either *note socket.SOCK_DGRAM: 14fa. for UDP or
     *note socket.SOCK_STREAM: 14fb. for TCP. The default protocol
     remains UDP.

   * *note Logger: d48. instances gained a *note getChild(): 14fc.
     method that retrieves a descendant logger using a relative path.
     For example, once you retrieve a logger by doing ‘log =
     getLogger('app')’, calling ‘log.getChild('network.listen')’ is
     equivalent to ‘getLogger('app.network.listen')’.

   * The *note LoggerAdapter: 14fd. class gained an *note
     isEnabledFor(): 14fe. method that takes a 'level' and returns
     whether the underlying logger would process a message of that level
     of importance.

Vedi anche
..........

PEP 391(1) - Dictionary-Based Configuration For Logging

     PEP written and implemented by Vinay Sajip.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0391/


File: python.info,  Node: PEP 3106 Dictionary Views,  Next: PEP 3137 The memoryview Object,  Prev: PEP 391 Dictionary-Based Configuration For Logging,  Up: What’s New in Python 2 7

1.16.8 PEP 3106: Dictionary Views
---------------------------------

The dictionary methods *note keys(): 9d2, *note values(): 9d3, and *note
items(): 9d4. are different in Python 3.x.  They return an object called
a 'view' instead of a fully materialized list.

It’s not possible to change the return values of *note keys(): 9d2,
*note values(): 9d3, and *note items(): 9d4. in Python 2.7 because too
much code would break.  Instead the 3.x versions were added under the
new names ‘viewkeys()’, ‘viewvalues()’, and ‘viewitems()’.

     >>> d = dict((i*10, chr(65+i)) for i in range(26))
     >>> d
     {0: 'A', 130: 'N', 10: 'B', 140: 'O', 20: ..., 250: 'Z'}
     >>> d.viewkeys()
     dict_keys([0, 130, 10, 140, 20, 150, 30, ..., 250])

Views can be iterated over, but the key and item views also behave like
sets.  The ‘&’ operator performs intersection, and ‘|’ performs a union:

     >>> d1 = dict((i*10, chr(65+i)) for i in range(26))
     >>> d2 = dict((i**.5, i) for i in range(1000))
     >>> d1.viewkeys() & d2.viewkeys()
     set([0.0, 10.0, 20.0, 30.0])
     >>> d1.viewkeys() | range(0, 30)
     set([0, 1, 130, 3, 4, 5, 6, ..., 120, 250])

The view keeps track of the dictionary and its contents change as the
dictionary is modified:

     >>> vk = d.viewkeys()
     >>> vk
     dict_keys([0, 130, 10, ..., 250])
     >>> d[260] = '&'
     >>> vk
     dict_keys([0, 130, 260, 10, ..., 250])

However, note that you can’t add or remove keys while you’re iterating
over the view:

     >>> for k in vk:
     ...     d[k*2] = k
     ...
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     RuntimeError: dictionary changed size during iteration

You can use the view methods in Python 2.x code, and the 2to3 converter
will change them to the standard *note keys(): 9d2, *note values(): 9d3,
and *note items(): 9d4. methods.

Vedi anche
..........

PEP 3106(1) - Revamping dict.keys(), .values() and .items()

     PEP written by Guido van Rossum.  Backported to 2.7 by Alexandre
     Vassalotti; bpo-1967(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3106/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1967


File: python.info,  Node: PEP 3137 The memoryview Object,  Next: Other Language Changes<13>,  Prev: PEP 3106 Dictionary Views,  Up: What’s New in Python 2 7

1.16.9 PEP 3137: The memoryview Object
--------------------------------------

The *note memoryview: 165. object provides a view of another object’s
memory content that matches the *note bytes: 192. type’s interface.

     >>> import string
     >>> m = memoryview(string.letters)
     >>> m
     <memory at 0x37f850>
     >>> len(m)           # Returns length of underlying object
     52
     >>> m[0], m[25], m[26]   # Indexing returns one byte
     ('a', 'z', 'A')
     >>> m2 = m[0:26]         # Slicing returns another memoryview
     >>> m2
     <memory at 0x37f080>

The content of the view can be converted to a string of bytes or a list
of integers:

     >>> m2.tobytes()
     'abcdefghijklmnopqrstuvwxyz'
     >>> m2.tolist()
     [97, 98, 99, 100, 101, 102, 103, ... 121, 122]
     >>>

*note memoryview: 165. objects allow modifying the underlying object if
it’s a mutable object.

     >>> m2[0] = 75
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: cannot modify read-only memory
     >>> b = bytearray(string.letters)  # Creating a mutable object
     >>> b
     bytearray(b'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ')
     >>> mb = memoryview(b)
     >>> mb[0] = '*'         # Assign to view, changing the bytearray.
     >>> b[0:5]              # The bytearray has been changed.
     bytearray(b'*bcde')
     >>>

Vedi anche
..........

PEP 3137(1) - Immutable Bytes and Mutable Buffer

     PEP written by Guido van Rossum.  Implemented by Travis Oliphant,
     Antoine Pitrou and others.  Backported to 2.7 by Antoine Pitrou;
     bpo-2396(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3137/

   (2) https://bugs.python.org/issue?@action=redirect&bpo=2396


File: python.info,  Node: Other Language Changes<13>,  Next: New and Improved Modules,  Prev: PEP 3137 The memoryview Object,  Up: What’s New in Python 2 7

1.16.10 Other Language Changes
------------------------------

Some smaller changes made to the core Python language are:

   * The syntax for set literals has been backported from Python 3.x.
     Curly brackets are used to surround the contents of the resulting
     mutable set; set literals are distinguished from dictionaries by
     not containing colons and values.  ‘{}’ continues to represent an
     empty dictionary; use ‘set()’ for an empty set.

          >>> {1, 2, 3, 4, 5}
          set([1, 2, 3, 4, 5])
          >>> set() # empty set
          set([])
          >>> {}    # empty dict
          {}

     Backported by Alexandre Vassalotti; bpo-2335(1).

   * Dictionary and set comprehensions are another feature backported
     from 3.x, generalizing list/generator comprehensions to use the
     literal syntax for sets and dictionaries.

          >>> {x: x*x for x in range(6)}
          {0: 0, 1: 1, 2: 4, 3: 9, 4: 16, 5: 25}
          >>> {('a'*x) for x in range(6)}
          set(['', 'a', 'aa', 'aaa', 'aaaa', 'aaaaa'])

     Backported by Alexandre Vassalotti; bpo-2333(2).

   * The *note with: 186. statement can now use multiple context
     managers in one statement.  Context managers are processed from
     left to right and each one is treated as beginning a new ‘with’
     statement.  This means that:

          with A() as a, B() as b:
              ... suite of statements ...

     is equivalent to:

          with A() as a:
              with B() as b:
                  ... suite of statements ...

     The ‘contextlib.nested()’ function provides a very similar
     function, so it’s no longer necessary and has been deprecated.

     (Proposed in ‘https://codereview.appspot.com/53094’; implemented by
     Georg Brandl.)

   * Conversions between floating-point numbers and strings are now
     correctly rounded on most platforms.  These conversions occur in
     many different places: *note str(): 169. on floats and complex
     numbers; the *note float: 196. and *note complex: 197.
     constructors; numeric formatting; serializing and deserializing
     floats and complex numbers using the *note marshal: 91, *note
     pickle: ab. and *note json: 86. modules; parsing of float and
     imaginary literals in Python code; and *note Decimal: 1fe.-to-float
     conversion.

     Related to this, the *note repr(): 1c1. of a floating-point number
     'x' now returns a result based on the shortest decimal string
     that’s guaranteed to round back to 'x' under correct rounding (with
     round-half-to-even rounding mode).  Previously it gave a string
     based on rounding x to 17 decimal digits.

     The rounding library responsible for this improvement works on
     Windows and on Unix platforms using the gcc, icc, or suncc
     compilers.  There may be a small number of platforms where correct
     operation of this code cannot be guaranteed, so the code is not
     used on such systems.  You can find out which code is being used by
     checking *note sys.float_repr_style: 1502, which will be ‘short’ if
     the new code is in use and ‘legacy’ if it isn’t.

     Implemented by Eric Smith and Mark Dickinson, using David Gay’s
     ‘dtoa.c’ library; bpo-7117(3).

   * Conversions from long integers and regular integers to floating
     point now round differently, returning the floating-point number
     closest to the number.  This doesn’t matter for small integers that
     can be converted exactly, but for large numbers that will
     unavoidably lose precision, Python 2.7 now approximates more
     closely.  For example, Python 2.6 computed the following:

          >>> n = 295147905179352891391
          >>> float(n)
          2.9514790517935283e+20
          >>> n - long(float(n))
          65535L

     Python 2.7’s floating-point result is larger, but much closer to
     the true value:

          >>> n = 295147905179352891391
          >>> float(n)
          2.9514790517935289e+20
          >>> n - long(float(n))
          -1L

     (Implemented by Mark Dickinson; bpo-3166(4).)

     Integer division is also more accurate in its rounding behaviours.
     (Also implemented by Mark Dickinson; bpo-1811(5).)

   * Implicit coercion for complex numbers has been removed; the
     interpreter will no longer ever attempt to call a ‘__coerce__()’
     method on complex objects.  (Removed by Meador Inge and Mark
     Dickinson; bpo-5211(6).)

   * The *note str.format(): 834. method now supports automatic
     numbering of the replacement fields.  This makes using *note
     str.format(): 834. more closely resemble using ‘%s’ formatting:

          >>> '{}:{}:{}'.format(2009, 04, 'Sunday')
          '2009:4:Sunday'
          >>> '{}:{}:{day}'.format(2009, 4, day='Sunday')
          '2009:4:Sunday'

     The auto-numbering takes the fields from left to right, so the
     first ‘{...}’ specifier will use the first argument to *note
     str.format(): 834, the next specifier will use the next argument,
     and so on.  You can’t mix auto-numbering and explicit numbering –
     either number all of your specifier fields or none of them – but
     you can mix auto-numbering and named fields, as in the second
     example above.  (Contributed by Eric Smith; bpo-5237(7).)

     Complex numbers now correctly support usage with *note format():
     199, and default to being right-aligned.  Specifying a precision or
     comma-separation applies to both the real and imaginary parts of
     the number, but a specified field width and alignment is applied to
     the whole of the resulting ‘1.5+3j’ output.  (Contributed by Eric
     Smith; bpo-1588(8) and bpo-7988(9).)

     The “F” format code now always formats its output using uppercase
     characters, so it will now produce “INF” and “NAN”.  (Contributed
     by Eric Smith; bpo-3382(10).)

     A low-level change: the *note object.__format__(): 832. method now
     triggers a *note PendingDeprecationWarning: ac8. if it’s passed a
     format string, because the ‘__format__()’ method for *note object:
     c80. converts the object to a string representation and formats
     that.  Previously the method silently applied the format string to
     the string representation, but that could hide mistakes in Python
     code.  If you’re supplying formatting information such as an
     alignment or precision, presumably you’re expecting the formatting
     to be applied in some object-specific way.  (Fixed by Eric Smith;
     bpo-7994(11).)

   * The *note int(): 19b. and ‘long()’ types gained a ‘bit_length’
     method that returns the number of bits necessary to represent its
     argument in binary:

          >>> n = 37
          >>> bin(n)
          '0b100101'
          >>> n.bit_length()
          6
          >>> n = 2**123-1
          >>> n.bit_length()
          123
          >>> (n+1).bit_length()
          124

     (Contributed by Fredrik Johansson and Victor Stinner;
     bpo-3439(12).)

   * The *note import: 7f9. statement will no longer try an absolute
     import if a relative import (e.g.  ‘from .os import sep’) fails.
     This fixes a bug, but could possibly break certain ‘import’
     statements that were only working by accident.  (Fixed by Meador
     Inge; bpo-7902(13).)

   * It’s now possible for a subclass of the built-in ‘unicode’ type to
     override the ‘__unicode__()’ method.  (Implemented by Victor
     Stinner; bpo-1583863(14).)

   * The *note bytearray: 344. type’s *note translate(): 1503. method
     now accepts ‘None’ as its first argument.  (Fixed by Georg Brandl;
     bpo-4759(15).)

   * When using *note @classmethod: 48f. and *note @staticmethod: 453.
     to wrap methods as class or static methods, the wrapper object now
     exposes the wrapped function as their *note __func__: 1504.
     attribute.  (Contributed by Amaury Forgeot d’Arc, after a
     suggestion by George Sakkis; bpo-5982(16).)

   * When a restricted set of attributes were set using ‘__slots__’,
     deleting an unset attribute would not raise *note AttributeError:
     5f0. as you would expect.  Fixed by Benjamin Peterson;
     bpo-7604(17).)

   * Two new encodings are now supported: «cp720», used primarily for
     Arabic text; and «cp858», a variant of CP 850 that adds the euro
     symbol.  (CP720 contributed by Alexander Belchenko and Amaury
     Forgeot d’Arc in bpo-1616979(18); CP858 contributed by Tim Hatch in
     bpo-8016(19).)

   * The ‘file’ object will now set the ‘filename’ attribute on the
     *note IOError: 1255. exception when trying to open a directory on
     POSIX platforms (noted by Jan Kaliszewski; bpo-4764(20)), and now
     explicitly checks for and forbids writing to read-only file objects
     instead of trusting the C library to catch and report the error
     (fixed by Stefan Krah; bpo-5677(21)).

   * The Python tokenizer now translates line endings itself, so the
     *note compile(): 4b2. built-in function now accepts code using any
     line-ending convention.  Additionally, it no longer requires that
     the code end in a newline.

   * Extra parentheses in function definitions are illegal in Python
     3.x, meaning that you get a syntax error from ‘def f((x)): pass’.
     In Python3-warning mode, Python 2.7 will now warn about this odd
     usage.  (Noted by James Lingard; bpo-7362(22).)

   * It’s now possible to create weak references to old-style class
     objects.  New-style classes were always weak-referenceable.  (Fixed
     by Antoine Pitrou; bpo-8268(23).)

   * When a module object is garbage-collected, the module’s dictionary
     is now only cleared if no one else is holding a reference to the
     dictionary (bpo-7140(24)).

* Menu:

* Interpreter Changes::
* Optimizations: Optimizations<13>.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=2335

   (2) https://bugs.python.org/issue?@action=redirect&bpo=2333

   (3) https://bugs.python.org/issue?@action=redirect&bpo=7117

   (4) https://bugs.python.org/issue?@action=redirect&bpo=3166

   (5) https://bugs.python.org/issue?@action=redirect&bpo=1811

   (6) https://bugs.python.org/issue?@action=redirect&bpo=5211

   (7) https://bugs.python.org/issue?@action=redirect&bpo=5237

   (8) https://bugs.python.org/issue?@action=redirect&bpo=1588

   (9) https://bugs.python.org/issue?@action=redirect&bpo=7988

   (10) https://bugs.python.org/issue?@action=redirect&bpo=3382

   (11) https://bugs.python.org/issue?@action=redirect&bpo=7994

   (12) https://bugs.python.org/issue?@action=redirect&bpo=3439

   (13) https://bugs.python.org/issue?@action=redirect&bpo=7902

   (14) https://bugs.python.org/issue?@action=redirect&bpo=1583863

   (15) https://bugs.python.org/issue?@action=redirect&bpo=4759

   (16) https://bugs.python.org/issue?@action=redirect&bpo=5982

   (17) https://bugs.python.org/issue?@action=redirect&bpo=7604

   (18) https://bugs.python.org/issue?@action=redirect&bpo=1616979

   (19) https://bugs.python.org/issue?@action=redirect&bpo=8016

   (20) https://bugs.python.org/issue?@action=redirect&bpo=4764

   (21) https://bugs.python.org/issue?@action=redirect&bpo=5677

   (22) https://bugs.python.org/issue?@action=redirect&bpo=7362

   (23) https://bugs.python.org/issue?@action=redirect&bpo=8268

   (24) https://bugs.python.org/issue?@action=redirect&bpo=7140


File: python.info,  Node: Interpreter Changes,  Next: Optimizations<13>,  Up: Other Language Changes<13>

1.16.10.1 Interpreter Changes
.............................

A new environment variable, *note PYTHONWARNINGS: da5, allows
controlling warnings.  It should be set to a string containing warning
settings, equivalent to those used with the *note -W: ac7. switch,
separated by commas.  (Contributed by Brian Curtin; bpo-7301(1).)

For example, the following setting will print warnings every time they
occur, but turn warnings from the *note Cookie: 75. module into an
error.  (The exact syntax for setting an environment variable varies
across operating systems and shells.)

     export PYTHONWARNINGS=all,error:::Cookie:0

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=7301


File: python.info,  Node: Optimizations<13>,  Prev: Interpreter Changes,  Up: Other Language Changes<13>

1.16.10.2 Optimizations
.......................

Several performance enhancements have been added:

   * A new opcode was added to perform the initial setup for *note with:
     186. statements, looking up the *note __enter__(): 7e5. and *note
     __exit__(): 1508. methods.  (Contributed by Benjamin Peterson.)

   * The garbage collector now performs better for one common usage
     pattern: when many objects are being allocated without deallocating
     any of them.  This would previously take quadratic time for garbage
     collection, but now the number of full garbage collections is
     reduced as the number of objects on the heap grows.  The new logic
     only performs a full garbage collection pass when the middle
     generation has been collected 10 times and when the number of
     survivor objects from the middle generation exceeds 10% of the
     number of objects in the oldest generation.  (Suggested by Martin
     von Löwis and implemented by Antoine Pitrou; bpo-4074(1).)

   * The garbage collector tries to avoid tracking simple containers
     which can’t be part of a cycle.  In Python 2.7, this is now true
     for tuples and dicts containing atomic types (such as ints,
     strings, etc.).  Transitively, a dict containing tuples of atomic
     types won’t be tracked either.  This helps reduce the cost of each
     garbage collection by decreasing the number of objects to be
     considered and traversed by the collector.  (Contributed by Antoine
     Pitrou; bpo-4688(2).)

   * Long integers are now stored internally either in base ‘2**15’ or
     in base ‘2**30’, the base being determined at build time.
     Previously, they were always stored in base ‘2**15’.  Using base
     ‘2**30’ gives significant performance improvements on 64-bit
     machines, but benchmark results on 32-bit machines have been mixed.
     Therefore, the default is to use base ‘2**30’ on 64-bit machines
     and base ‘2**15’ on 32-bit machines; on Unix, there’s a new
     configure option ‘--enable-big-digits’ that can be used to override
     this default.

     Apart from the performance improvements this change should be
     invisible to end users, with one exception: for testing and
     debugging purposes there’s a new structseq ‘sys.long_info’ that
     provides information about the internal format, giving the number
     of bits per digit and the size in bytes of the C type used to store
     each digit:

          >>> import sys
          >>> sys.long_info
          sys.long_info(bits_per_digit=30, sizeof_digit=4)

     (Contributed by Mark Dickinson; bpo-4258(3).)

     Another set of changes made long objects a few bytes smaller: 2
     bytes smaller on 32-bit systems and 6 bytes on 64-bit.
     (Contributed by Mark Dickinson; bpo-5260(4).)

   * The division algorithm for long integers has been made faster by
     tightening the inner loop, doing shifts instead of multiplications,
     and fixing an unnecessary extra iteration.  Various benchmarks show
     speedups of between 50% and 150% for long integer divisions and
     modulo operations.  (Contributed by Mark Dickinson; bpo-5512(5).)
     Bitwise operations are also significantly faster (initial patch by
     Gregory Smith; bpo-1087418(6)).

   * The implementation of ‘%’ checks for the left-side operand being a
     Python string and special-cases it; this results in a 1–3%
     performance increase for applications that frequently use ‘%’ with
     strings, such as templating libraries.  (Implemented by Collin
     Winter; bpo-5176(7).)

   * List comprehensions with an ‘if’ condition are compiled into faster
     bytecode.  (Patch by Antoine Pitrou, back-ported to 2.7 by Jeffrey
     Yasskin; bpo-4715(8).)

   * Converting an integer or long integer to a decimal string was made
     faster by special-casing base 10 instead of using a generalized
     conversion function that supports arbitrary bases.  (Patch by
     Gawain Bolton; bpo-6713(9).)

   * The ‘split()’, ‘replace()’, ‘rindex()’, ‘rpartition()’, and
     ‘rsplit()’ methods of string-like types (strings, Unicode strings,
     and *note bytearray: 344. objects) now use a fast reverse-search
     algorithm instead of a character-by-character scan.  This is
     sometimes faster by a factor of 10.  (Added by Florent Xicluna;
     bpo-7462(10) and bpo-7622(11).)

   * The *note pickle: ab. and ‘cPickle’ modules now automatically
     intern the strings used for attribute names, reducing memory usage
     of the objects resulting from unpickling.  (Contributed by Jake
     McGuire; bpo-5084(12).)

   * The ‘cPickle’ module now special-cases dictionaries, nearly halving
     the time required to pickle them.  (Contributed by Collin Winter;
     bpo-5670(13).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4074

   (2) https://bugs.python.org/issue?@action=redirect&bpo=4688

   (3) https://bugs.python.org/issue?@action=redirect&bpo=4258

   (4) https://bugs.python.org/issue?@action=redirect&bpo=5260

   (5) https://bugs.python.org/issue?@action=redirect&bpo=5512

   (6) https://bugs.python.org/issue?@action=redirect&bpo=1087418

   (7) https://bugs.python.org/issue?@action=redirect&bpo=5176

   (8) https://bugs.python.org/issue?@action=redirect&bpo=4715

   (9) https://bugs.python.org/issue?@action=redirect&bpo=6713

   (10) https://bugs.python.org/issue?@action=redirect&bpo=7462

   (11) https://bugs.python.org/issue?@action=redirect&bpo=7622

   (12) https://bugs.python.org/issue?@action=redirect&bpo=5084

   (13) https://bugs.python.org/issue?@action=redirect&bpo=5670


File: python.info,  Node: New and Improved Modules,  Next: Build and C API Changes<8>,  Prev: Other Language Changes<13>,  Up: What’s New in Python 2 7

1.16.11 New and Improved Modules
--------------------------------

As in every release, Python’s standard library received a number of
enhancements and bug fixes.  Here’s a partial list of the most notable
changes, sorted alphabetically by module name.  Consult the ‘Misc/NEWS’
file in the source tree for a more complete list of changes, or look
through the Subversion logs for all the details.

   * The *note bdb: 10. module’s base debugging class *note Bdb: 2d5.
     gained a feature for skipping modules.  The constructor now takes
     an iterable containing glob-style patterns such as ‘django.*’; the
     debugger will not step into stack frames from a module that matches
     one of these patterns.  (Contributed by Maru Newby after a
     suggestion by Senthil Kumaran; bpo-5142(1).)

   * The *note binascii: 11. module now supports the buffer API, so it
     can be used with *note memoryview: 165. instances and other similar
     buffer objects.  (Backported from 3.x by Florent Xicluna;
     bpo-7703(2).)

   * Updated module: the ‘bsddb’ module has been updated from
     4.7.2devel9 to version 4.8.4 of the pybsddb package(3).  The new
     version features better Python 3.x compatibility, various bug
     fixes, and adds several new BerkeleyDB flags and methods.  (Updated
     by Jesús Cea Avión; bpo-8156(4).  The pybsddb changelog can be read
     at ‘https://hg.jcea.es/pybsddb/file/tip/ChangeLog’.)

   * The *note bz2: 14. module’s *note BZ2File: a68. now supports the
     context management protocol, so you can write ‘with
     bz2.BZ2File(...) as f:’.  (Contributed by Hagen Fürstenau;
     bpo-3860(5).)

   * New class: the *note Counter: 1299. class in the *note collections:
     1e. module is useful for tallying data.  *note Counter: 1299.
     instances behave mostly like dictionaries but return zero for
     missing keys instead of raising a *note KeyError: 5e7.:

          >>> from collections import Counter
          >>> c = Counter()
          >>> for letter in 'here is a sample of english text':
          ...   c[letter] += 1
          ...
          >>> c
          Counter({' ': 6, 'e': 5, 's': 3, 'a': 2, 'i': 2, 'h': 2,
          'l': 2, 't': 2, 'g': 1, 'f': 1, 'm': 1, 'o': 1, 'n': 1,
          'p': 1, 'r': 1, 'x': 1})
          >>> c['e']
          5
          >>> c['z']
          0

     There are three additional *note Counter: 1299. methods.  *note
     most_common(): 150a. returns the N most common elements and their
     counts.  *note elements(): 150b. returns an iterator over the
     contained elements, repeating each element as many times as its
     count.  *note subtract(): 13e6. takes an iterable and subtracts one
     for each element instead of adding; if the argument is a dictionary
     or another ‘Counter’, the counts are subtracted.

          >>> c.most_common(5)
          [(' ', 6), ('e', 5), ('s', 3), ('a', 2), ('i', 2)]
          >>> c.elements() ->
             'a', 'a', ' ', ' ', ' ', ' ', ' ', ' ',
             'e', 'e', 'e', 'e', 'e', 'g', 'f', 'i', 'i',
             'h', 'h', 'm', 'l', 'l', 'o', 'n', 'p', 's',
             's', 's', 'r', 't', 't', 'x'
          >>> c['e']
          5
          >>> c.subtract('very heavy on the letter e')
          >>> c['e']    # Count is now lower
          -1

     Contributed by Raymond Hettinger; bpo-1696199(6).

     New class: *note OrderedDict: 7f4. is described in the earlier
     section *note PEP 372; Adding an Ordered Dictionary to collections:
     14f1.

     New method: The *note deque: 7f5. data type now has a *note
     count(): 13e8. method that returns the number of contained elements
     equal to the supplied argument 'x', and a *note reverse(): 13e9.
     method that reverses the elements of the deque in-place.  *note
     deque: 7f5. also exposes its maximum length as the read-only *note
     maxlen: 150c. attribute.  (Both features added by Raymond
     Hettinger.)

     The *note namedtuple: 4e1. class now has an optional 'rename'
     parameter.  If 'rename' is true, field names that are invalid
     because they’ve been repeated or aren’t legal Python identifiers
     will be renamed to legal names that are derived from the field’s
     position within the list of fields:

          >>> from collections import namedtuple
          >>> T = namedtuple('T', ['field1', '$illegal', 'for', 'field2'], rename=True)
          >>> T._fields
          ('field1', '_1', '_2', 'field2')

     (Added by Raymond Hettinger; bpo-1818(7).)

     Finally, the *note Mapping: ac9. abstract base class now returns
     *note NotImplemented: 1a2. if a mapping is compared to another type
     that isn’t a ‘Mapping’.  (Fixed by Daniel Stutzbach; bpo-8729(8).)

   * Constructors for the parsing classes in the *note ConfigParser: 26.
     module now take an 'allow_no_value' parameter, defaulting to false;
     if true, options without values will be allowed.  For example:

          >>> import ConfigParser, StringIO
          >>> sample_config = """
          ... [mysqld]
          ... user = mysql
          ... pid-file = /var/run/mysqld/mysqld.pid
          ... skip-bdb
          ... """
          >>> config = ConfigParser.RawConfigParser(allow_no_value=True)
          >>> config.readfp(StringIO.StringIO(sample_config))
          >>> config.get('mysqld', 'user')
          'mysql'
          >>> print config.get('mysqld', 'skip-bdb')
          None
          >>> print config.get('mysqld', 'unknown')
          Traceback (most recent call last):
            ...
          NoOptionError: No option 'unknown' in section: 'mysqld'

     (Contributed by Mats Kindahl; bpo-7005(9).)

   * Deprecated function: ‘contextlib.nested()’, which allows handling
     more than one context manager with a single *note with: 186.
     statement, has been deprecated, because the ‘with’ statement now
     supports multiple context managers.

   * The *note cookielib: 74. module now ignores cookies that have an
     invalid version field, one that doesn’t contain an integer value.
     (Fixed by John J. Lee; bpo-3924(10).)

   * The *note copy: 29. module’s *note deepcopy(): d67. function will
     now correctly copy bound instance methods.  (Implemented by Robert
     Collins; bpo-1515(11).)

   * The *note ctypes: 2e. module now always converts ‘None’ to a C
     ‘NULL’ pointer for arguments declared as pointers.  (Changed by
     Thomas Heller; bpo-4606(12).)  The underlying libffi library(13)
     has been updated to version 3.0.9, containing various fixes for
     different platforms.  (Updated by Matthias Klose; bpo-8142(14).)

   * New method: the *note datetime: 34. module’s *note timedelta: bc5.
     class gained a *note total_seconds(): 150d. method that returns the
     number of seconds in the duration.  (Contributed by Brian Quinlan;
     bpo-5788(15).)

   * New method: the *note Decimal: 1fe. class gained a *note
     from_float(): 140c. class method that performs an exact conversion
     of a floating-point number to a ‘Decimal’.  This exact conversion
     strives for the closest decimal approximation to the floating-point
     representation’s value; the resulting decimal value will therefore
     still include the inaccuracy, if any.  For example,
     ‘Decimal.from_float(0.1)’ returns
     ‘Decimal('0.1000000000000000055511151231257827021181583404541015625')’.
     (Implemented by Raymond Hettinger; bpo-4796(16).)

     Comparing instances of *note Decimal: 1fe. with floating-point
     numbers now produces sensible results based on the numeric values
     of the operands.  Previously such comparisons would fall back to
     Python’s default rules for comparing objects, which produced
     arbitrary results based on their type.  Note that you still cannot
     combine ‘Decimal’ and floating point in other operations such as
     addition, since you should be explicitly choosing how to convert
     between float and ‘Decimal’.  (Fixed by Mark Dickinson;
     bpo-2531(17).)

     The constructor for *note Decimal: 1fe. now accepts floating-point
     numbers (added by Raymond Hettinger; bpo-8257(18)) and non-European
     Unicode characters such as Arabic-Indic digits (contributed by Mark
     Dickinson; bpo-6595(19)).

     Most of the methods of the *note Context: 12b7. class now accept
     integers as well as *note Decimal: 1fe. instances; the only
     exceptions are the *note canonical(): 150e. and *note
     is_canonical(): 150f. methods.  (Patch by Juan José Conti;
     bpo-7633(20).)

     When using *note Decimal: 1fe. instances with a string’s *note
     format(): 834. method, the default alignment was previously
     left-alignment.  This has been changed to right-alignment, which is
     more sensible for numeric types.  (Changed by Mark Dickinson;
     bpo-6857(21).)

     Comparisons involving a signaling NaN value (or ‘sNAN’) now signal
     *note InvalidOperation: 12b0. instead of silently returning a true
     or false value depending on the comparison operator.  Quiet NaN
     values (or ‘NaN’) are now hashable.  (Fixed by Mark Dickinson;
     bpo-7279(22).)

   * The *note difflib: 3b. module now produces output that is more
     compatible with modern ‘diff’/‘patch’ tools through one small
     change, using a tab character instead of spaces as a separator in
     the header giving the filename.  (Fixed by Anatoly Techtonik;
     bpo-7585(23).)

   * The Distutils ‘sdist’ command now always regenerates the ‘MANIFEST’
     file, since even if the ‘MANIFEST.in’ or ‘setup.py’ files haven’t
     been modified, the user might have created some new files that
     should be included.  (Fixed by Tarek Ziadé; bpo-8688(24).)

   * The *note doctest: 3e. module’s *note IGNORE_EXCEPTION_DETAIL:
     1510. flag will now ignore the name of the module containing the
     exception being tested.  (Patch by Lennart Regebro; bpo-7490(25).)

   * The *note email: 3f. module’s *note Message: 581. class will now
     accept a Unicode-valued payload, automatically converting the
     payload to the encoding specified by ‘output_charset’.  (Added by
     R.  David Murray; bpo-1368247(26).)

   * The *note Fraction: 213. class now accepts a single float or *note
     Decimal: 1fe. instance, or two rational numbers, as arguments to
     its constructor.  (Implemented by Mark Dickinson; rationals added
     in bpo-5812(27), and float/decimal in bpo-8294(28).)

     Ordering comparisons (‘<’, ‘<=’, ‘>’, ‘>=’) between fractions and
     complex numbers now raise a *note TypeError: 198.  This fixes an
     oversight, making the *note Fraction: 213. match the other numeric
     types.

   * New class: *note FTP_TLS: af9. in the *note ftplib: 62. module
     provides secure FTP connections using TLS encapsulation of
     authentication as well as subsequent control and data transfers.
     (Contributed by Giampaolo Rodola; bpo-2054(29).)

     The *note storbinary(): 1511. method for binary uploads can now
     restart uploads thanks to an added 'rest' parameter (patch by Pablo
     Mouzo; bpo-6845(30).)

   * New class decorator: *note total_ordering(): 1144. in the *note
     functools: 63. module takes a class that defines an *note __eq__():
     cf4. method and one of *note __lt__(): 14a8, *note __le__(): 1512,
     *note __gt__(): 1513, or *note __ge__(): 1514, and generates the
     missing comparison methods.  Since the ‘__cmp__()’ method is being
     deprecated in Python 3.x, this decorator makes it easier to define
     ordered classes.  (Added by Raymond Hettinger; bpo-5479(31).)

     New function: *note cmp_to_key(): 13e2. will take an old-style
     comparison function that expects two arguments and return a new
     callable that can be used as the 'key' parameter to functions such
     as *note sorted(): dc9, *note min(): 110d. and *note max(): 110e,
     etc.  The primary intended use is to help with making code
     compatible with Python 3.x.  (Added by Raymond Hettinger.)

   * New function: the *note gc: 64. module’s *note is_tracked(): 1515.
     returns true if a given instance is tracked by the garbage
     collector, false otherwise.  (Contributed by Antoine Pitrou;
     bpo-4688(32).)

   * The *note gzip: 6b. module’s *note GzipFile: 65c. now supports the
     context management protocol, so you can write ‘with
     gzip.GzipFile(...) as f:’ (contributed by Hagen Fürstenau;
     bpo-3860(33)), and it now implements the *note io.BufferedIOBase:
     8a4. ABC, so you can wrap it with *note io.BufferedReader: 1416.
     for faster processing (contributed by Nir Aides; bpo-7471(34)).
     It’s also now possible to override the modification time recorded
     in a gzipped file by providing an optional timestamp to the
     constructor.  (Contributed by Jacques Frechet; bpo-4272(35).)

     Files in gzip format can be padded with trailing zero bytes; the
     *note gzip: 6b. module will now consume these trailing bytes.
     (Fixed by Tadek Pietraszek and Brian Curtin; bpo-2846(36).)

   * New attribute: the *note hashlib: 6c. module now has an
     ‘algorithms’ attribute containing a tuple naming the supported
     algorithms.  In Python 2.7, ‘hashlib.algorithms’ contains ‘('md5',
     'sha1', 'sha224', 'sha256', 'sha384', 'sha512')’.  (Contributed by
     Carl Chenet; bpo-7418(37).)

   * The default *note HTTPResponse: 12d6. class used by the *note
     httplib: 72. module now supports buffering, resulting in much
     faster reading of HTTP responses.  (Contributed by Kristján Valur
     Jónsson; bpo-4879(38).)

     The *note HTTPConnection: d37. and *note HTTPSConnection: d38.
     classes now support a 'source_address' parameter, a ‘(host, port)’
     2-tuple giving the source address that will be used for the
     connection.  (Contributed by Eldon Ziegler; bpo-3972(39).)

   * The ‘ihooks’ module now supports relative imports.  Note that
     ‘ihooks’ is an older module for customizing imports, superseded by
     the ‘imputil’ module added in Python 2.0.  (Relative import support
     added by Neil Schemenauer.)

   * The *note imaplib: 78. module now supports IPv6 addresses.
     (Contributed by Derek Morr; bpo-1655(40).)

   * New function: the *note inspect: 82. module’s *note getcallargs():
     10c0. takes a callable and its positional and keyword arguments,
     and figures out which of the callable’s parameters will receive
     each argument, returning a dictionary mapping argument names to
     their values.  For example:

          >>> from inspect import getcallargs
          >>> def f(a, b=1, *pos, **named):
          ...     pass
          ...
          >>> getcallargs(f, 1, 2, 3)
          {'a': 1, 'b': 2, 'pos': (3,), 'named': {}}
          >>> getcallargs(f, a=2, x=4)
          {'a': 2, 'b': 1, 'pos': (), 'named': {'x': 4}}
          >>> getcallargs(f)
          Traceback (most recent call last):
          ...
          TypeError: f() takes at least 1 argument (0 given)

     Contributed by George Sakkis; bpo-3135(41).

   * Updated module: The *note io: 83. library has been upgraded to the
     version shipped with Python 3.1.  For 3.1, the I/O library was
     entirely rewritten in C and is 2 to 20 times faster depending on
     the task being performed.  The original Python version was renamed
     to the ‘_pyio’ module.

     One minor resulting change: the *note io.TextIOBase: 8a5. class now
     has an *note errors: 1516. attribute giving the error setting used
     for encoding and decoding errors (one of ‘'strict'’, ‘'replace'’,
     ‘'ignore'’).

     The *note io.FileIO: 1517. class now raises an *note OSError: 2c0.
     when passed an invalid file descriptor.  (Implemented by Benjamin
     Peterson; bpo-4991(42).)  The *note truncate(): 1518. method now
     preserves the file position; previously it would change the file
     position to the end of the new file.  (Fixed by Pascal Chambon;
     bpo-6939(43).)

   * New function: ‘itertools.compress(data, selectors)’ takes two
     iterators.  Elements of 'data' are returned if the corresponding
     value in 'selectors' is true:

          itertools.compress('ABCDEF', [1,0,1,0,1,1]) =>
            A, C, E, F

     New function: ‘itertools.combinations_with_replacement(iter, r)’
     returns all the possible 'r'-length combinations of elements from
     the iterable 'iter'.  Unlike *note combinations(): 1519, individual
     elements can be repeated in the generated combinations:

          itertools.combinations_with_replacement('abc', 2) =>
            ('a', 'a'), ('a', 'b'), ('a', 'c'),
            ('b', 'b'), ('b', 'c'), ('c', 'c')

     Note that elements are treated as unique depending on their
     position in the input, not their actual values.

     The *note itertools.count(): 148b. function now has a 'step'
     argument that allows incrementing by values other than 1.  *note
     count(): 148b. also now allows keyword arguments, and using
     non-integer values such as floats or *note Decimal: 1fe. instances.
     (Implemented by Raymond Hettinger; bpo-5032(44).)

     *note itertools.combinations(): 1519. and *note
     itertools.product(): 151a. previously raised *note ValueError: 2ec.
     for values of 'r' larger than the input iterable.  This was deemed
     a specification error, so they now return an empty iterator.
     (Fixed by Raymond Hettinger; bpo-4816(45).)

   * Updated module: The *note json: 86. module was upgraded to version
     2.0.9 of the simplejson package, which includes a C extension that
     makes encoding and decoding faster.  (Contributed by Bob Ippolito;
     bpo-4136(46).)

     To support the new *note collections.OrderedDict: 7f4. type, *note
     json.load(): eb4. now has an optional 'object_pairs_hook' parameter
     that will be called with any object literal that decodes to a list
     of pairs.  (Contributed by Raymond Hettinger; bpo-5381(47).)

   * The *note mailbox: 8f. module’s *note Maildir: 65e. class now
     records the timestamp on the directories it reads, and only
     re-reads them if the modification time has subsequently changed.
     This improves performance by avoiding unneeded directory scans.
     (Fixed by A.M. Kuchling and Antoine Pitrou; bpo-1607951(48),
     bpo-6896(49).)

   * New functions: the *note math: 92. module gained *note erf(): dd5.
     and *note erfc(): dd6. for the error function and the complementary
     error function, *note expm1(): 13f4. which computes ‘e**x - 1’ with
     more precision than using *note exp(): 151b. and subtracting 1,
     *note gamma(): 13f5. for the Gamma function, and *note lgamma():
     13f6. for the natural log of the Gamma function.  (Contributed by
     Mark Dickinson and nirinA raseliarison; bpo-3366(50).)

   * The *note multiprocessing: 98. module’s ‘Manager*’ classes can now
     be passed a callable that will be called whenever a subprocess is
     started, along with a set of arguments that will be passed to the
     callable.  (Contributed by lekma; bpo-5585(51).)

     The *note Pool: 116d. class, which controls a pool of worker
     processes, now has an optional 'maxtasksperchild' parameter.
     Worker processes will perform the specified number of tasks and
     then exit, causing the ‘Pool’ to start a new worker.  This is
     useful if tasks may leak memory or other resources, or if some
     tasks will cause the worker to become very large.  (Contributed by
     Charles Cazabon; bpo-6963(52).)

   * The ‘nntplib’ module now supports IPv6 addresses.  (Contributed by
     Derek Morr; bpo-1664(53).)

   * New functions: the *note os: a5. module wraps the following POSIX
     system calls: *note getresgid(): 151c. and *note getresuid(): 151d,
     which return the real, effective, and saved GIDs and UIDs; *note
     setresgid(): 151e. and *note setresuid(): 151f, which set real,
     effective, and saved GIDs and UIDs to new values; *note
     initgroups(): 1520, which initialize the group access list for the
     current process.  (GID/UID functions contributed by Travis H.;
     bpo-6508(54).  Support for initgroups added by Jean-Paul Calderone;
     bpo-7333(55).)

     The *note os.fork(): 4b6. function now re-initializes the import
     lock in the child process; this fixes problems on Solaris when
     *note fork(): 4b6. is called from a thread.  (Fixed by Zsolt
     Cserna; bpo-7242(56).)

   * In the *note os.path: a6. module, the *note normpath(): 1521. and
     *note abspath(): 1522. functions now preserve Unicode; if their
     input path is a Unicode string, the return value is also a Unicode
     string.  (*note normpath(): 1521. fixed by Matt Giuca in
     bpo-5827(57); *note abspath(): 1522. fixed by Ezio Melotti in
     bpo-3426(58).)

   * The *note pydoc: ba. module now has help for the various symbols
     that Python uses.  You can now do ‘help('<<')’ or ‘help('@')’, for
     example.  (Contributed by David Laban; bpo-4739(59).)

   * The *note re: be. module’s *note split(): 5a2, *note sub(): 5a3,
     and *note subn(): 5a4. now accept an optional 'flags' argument, for
     consistency with the other functions in the module.  (Added by
     Gregory P. Smith.)

   * New function: *note run_path(): 4a5. in the *note runpy: c3. module
     will execute the code at a provided 'path' argument.  'path' can be
     the path of a Python source file (‘example.py’), a compiled
     bytecode file (‘example.pyc’), a directory (‘./package/’), or a zip
     archive (‘example.zip’).  If a directory or zip path is provided,
     it will be added to the front of ‘sys.path’ and the module *note
     __main__: 1. will be imported.  It’s expected that the directory or
     zip contains a ‘__main__.py’; if it doesn’t, some other
     ‘__main__.py’ might be imported from a location later in
     ‘sys.path’.  This makes more of the machinery of *note runpy: c3.
     available to scripts that want to mimic the way Python’s command
     line processes an explicit path name.  (Added by Nick Coghlan;
     bpo-6816(60).)

   * New function: in the *note shutil: ca. module, *note
     make_archive(): 6db. takes a filename, archive type (zip or
     tar-format), and a directory path, and creates an archive
     containing the directory’s contents.  (Added by Tarek Ziadé.)

     *note shutil: ca.’s *note copyfile(): c50. and *note copytree():
     c20. functions now raise a *note SpecialFileError: 1523. exception
     when asked to copy a named pipe.  Previously the code would treat
     named pipes like a regular file by opening them for reading, and
     this would block indefinitely.  (Fixed by Antoine Pitrou;
     bpo-3002(61).)

   * The *note signal: cb. module no longer re-installs the signal
     handler unless this is truly necessary, which fixes a bug that
     could make it impossible to catch the EINTR signal robustly.
     (Fixed by Charles-Francois Natali; bpo-8354(62).)

   * New functions: in the *note site: cc. module, three new functions
     return various site- and user-specific paths.  *note
     getsitepackages(): 1446. returns a list containing all global
     site-packages directories, *note getusersitepackages(): 1448.
     returns the path of the user’s site-packages directory, and *note
     getuserbase(): 1447. returns the value of the *note USER_BASE:
     1524. environment variable, giving the path to a directory that can
     be used to store data.  (Contributed by Tarek Ziadé; bpo-6693(63).)

     The *note site: cc. module now reports exceptions occurring when
     the *note sitecustomize: cd. module is imported, and will no longer
     catch and swallow the *note KeyboardInterrupt: bc7. exception.
     (Fixed by Victor Stinner; bpo-3137(64).)

   * The *note create_connection(): 883. function gained a
     'source_address' parameter, a ‘(host, port)’ 2-tuple giving the
     source address that will be used for the connection.  (Contributed
     by Eldon Ziegler; bpo-3972(65).)

     The *note recv_into(): 1525. and *note recvfrom_into(): 1526.
     methods will now write into objects that support the buffer API,
     most usefully the *note bytearray: 344. and *note memoryview: 165.
     objects.  (Implemented by Antoine Pitrou; bpo-8104(66).)

   * The *note SocketServer: d2. module’s *note TCPServer: 1527. class
     now supports socket timeouts and disabling the Nagle algorithm.
     The ‘disable_nagle_algorithm’ class attribute defaults to ‘False’;
     if overridden to be true, new request connections will have the
     TCP_NODELAY option set to prevent buffering many small sends into a
     single TCP packet.  The *note timeout: 1528. class attribute can
     hold a timeout in seconds that will be applied to the request
     socket; if no request is received within that time, *note
     handle_timeout(): 1529. will be called and *note handle_request():
     152a. will return.  (Contributed by Kristján Valur Jónsson;
     bpo-6192(67) and bpo-6267(68).)

   * Updated module: the *note sqlite3: d4. module has been updated to
     version 2.6.0 of the pysqlite package(69).  Version 2.6.0 includes
     a number of bugfixes, and adds the ability to load SQLite
     extensions from shared libraries.  Call the
     ‘enable_load_extension(True)’ method to enable extensions, and then
     call *note load_extension(): 6e0. to load a particular shared
     library.  (Updated by Gerhard Häring.)

   * The *note ssl: d5. module’s *note SSLSocket: ae9. objects now
     support the buffer API, which fixed a test suite failure (fix by
     Antoine Pitrou; bpo-7133(70)) and automatically set OpenSSL’s
     ‘SSL_MODE_AUTO_RETRY’, which will prevent an error code being
     returned from ‘recv()’ operations that trigger an SSL renegotiation
     (fix by Antoine Pitrou; bpo-8222(71)).

     The *note wrap_socket(): 749. constructor function now takes a
     'ciphers' argument that’s a string listing the encryption
     algorithms to be allowed; the format of the string is described in
     the OpenSSL documentation(72).  (Added by Antoine Pitrou;
     bpo-8322(73).)

     Another change makes the extension load all of OpenSSL’s ciphers
     and digest algorithms so that they’re all available.  Some SSL
     certificates couldn’t be verified, reporting an «unknown algorithm»
     error.  (Reported by Beda Kosata, and fixed by Antoine Pitrou;
     bpo-8484(74).)

     The version of OpenSSL being used is now available as the module
     attributes *note ssl.OPENSSL_VERSION: 1426. (a string), *note
     ssl.OPENSSL_VERSION_INFO: 1427. (a 5-tuple), and *note
     ssl.OPENSSL_VERSION_NUMBER: 1428. (an integer).  (Added by Antoine
     Pitrou; bpo-8321(75).)

   * The *note struct: db. module will no longer silently ignore
     overflow errors when a value is too large for a particular integer
     format code (one of ‘bBhHiIlLqQ’); it now always raises a *note
     struct.error: 152b. exception.  (Changed by Mark Dickinson;
     bpo-1523(76).)  The *note pack(): 147e. function will also attempt
     to use *note __index__(): 19e. to convert and pack non-integers
     before trying the *note __int__(): 19d. method or reporting an
     error.  (Changed by Mark Dickinson; bpo-8300(77).)

   * New function: the *note subprocess: dc. module’s *note
     check_output(): 11c4. runs a command with a specified set of
     arguments and returns the command’s output as a string when the
     command runs without error, or raises a *note CalledProcessError:
     152c. exception otherwise.

          >>> subprocess.check_output(['df', '-h', '.'])
          'Filesystem     Size   Used  Avail Capacity  Mounted on\n
          /dev/disk0s2    52G    49G   3.0G    94%    /\n'

          >>> subprocess.check_output(['df', '-h', '/bogus'])
            ...
          subprocess.CalledProcessError: Command '['df', '-h', '/bogus']' returned non-zero exit status 1

     (Contributed by Gregory P. Smith.)

     The *note subprocess: dc. module will now retry its internal system
     calls on receiving an *note EINTR: f89. signal.  (Reported by
     several people; final patch by Gregory P. Smith in
     bpo-1068268(78).)

   * New function: *note is_declared_global(): 152d. in the *note
     symtable: de. module returns true for variables that are explicitly
     declared to be global, false for ones that are implicitly global.
     (Contributed by Jeremy Hylton.)

   * The *note syslog: e2. module will now use the value of
     ‘sys.argv[0]’ as the identifier instead of the previous default
     value of ‘'python'’.  (Changed by Sean Reifschneider;
     bpo-8451(79).)

   * The *note sys.version_info: 8b0. value is now a named tuple, with
     attributes named ‘major’, ‘minor’, ‘micro’, ‘releaselevel’, and
     ‘serial’.  (Contributed by Ross Light; bpo-4285(80).)

     *note sys.getwindowsversion(): ee5. also returns a named tuple,
     with attributes named ‘major’, ‘minor’, ‘build’, ‘platform’,
     ‘service_pack’, ‘service_pack_major’, ‘service_pack_minor’,
     ‘suite_mask’, and ‘product_type’.  (Contributed by Brian Curtin;
     bpo-7766(81).)

   * The *note tarfile: e4. module’s default error handling has changed,
     to no longer suppress fatal errors.  The default error level was
     previously 0, which meant that errors would only result in a
     message being written to the debug log, but because the debug log
     is not activated by default, these errors go unnoticed.  The
     default error level is now 1, which raises an exception if there’s
     an error.  (Changed by Lars Gustäbel; bpo-7357(82).)

     *note tarfile: e4. now supports filtering the *note TarInfo: 1419.
     objects being added to a tar file.  When you call *note add(): df0,
     you may supply an optional 'filter' argument that’s a callable.
     The 'filter' callable will be passed the *note TarInfo: 1419. for
     every file being added, and can modify and return it.  If the
     callable returns ‘None’, the file will be excluded from the
     resulting archive.  This is more powerful than the existing
     'exclude' argument, which has therefore been deprecated.  (Added by
     Lars Gustäbel; bpo-6856(83).)  The *note TarFile: 1418. class also
     now supports the context management protocol.  (Added by Lars
     Gustäbel; bpo-7232(84).)

   * The *note wait(): 152e. method of the *note threading.Event: 1360.
     class now returns the internal flag on exit.  This means the method
     will usually return true because *note wait(): 152e. is supposed to
     block until the internal flag becomes true.  The return value will
     only be false if a timeout was provided and the operation timed
     out.  (Contributed by Tim Lesher; bpo-1674032(85).)

   * The Unicode database provided by the *note unicodedata: 10b. module
     is now used internally to determine which characters are numeric,
     whitespace, or represent line breaks.  The database also includes
     information from the ‘Unihan.txt’ data file (patch by Anders
     Chrigström and Amaury Forgeot d’Arc; bpo-1571184(86)) and has been
     updated to version 5.2.0 (updated by Florent Xicluna;
     bpo-8024(87)).

   * The *note urlparse: 110. module’s *note urlsplit(): f3c. now
     handles unknown URL schemes in a fashion compliant with RFC
     3986(88): if the URL is of the form ‘"<something>://..."’, the text
     before the ‘://’ is treated as the scheme, even if it’s a made-up
     scheme that the module doesn’t know about.  This change may break
     code that worked around the old behaviour.  For example, Python
     2.6.4 or 2.5 will return the following:

          >>> import urlparse
          >>> urlparse.urlsplit('invented://host/filename?query')
          ('invented', '', '//host/filename?query', '', '')

     Python 2.7 (and Python 2.6.5) will return:

          >>> import urlparse
          >>> urlparse.urlsplit('invented://host/filename?query')
          ('invented', 'host', '/filename?query', '', '')

     (Python 2.7 actually produces slightly different output, since it
     returns a named tuple instead of a standard tuple.)

     The *note urlparse: 110. module also supports IPv6 literal
     addresses as defined by RFC 2732(89) (contributed by Senthil
     Kumaran; bpo-2987(90)).

          >>> urlparse.urlparse('http://[1080::8:800:200C:417A]/foo')
          ParseResult(scheme='http', netloc='[1080::8:800:200C:417A]',
                      path='/foo', params='', query='', fragment='')

   * New class: the *note WeakSet: 7f6. class in the *note weakref: 11a.
     module is a set that only holds weak references to its elements;
     elements will be removed once there are no references pointing to
     them.  (Originally implemented in Python 3.x by Raymond Hettinger,
     and backported to 2.7 by Michael Foord.)

   * The *note xml.etree.ElementTree: 12b. library, no longer escapes
     ampersands and angle brackets when outputting an XML processing
     instruction (which looks like ‘<?xml-stylesheet href="#style1"?>’)
     or comment (which looks like ‘<!-- comment -->’).  (Patch by Neil
     Muller; bpo-2746(91).)

   * The XML-RPC client and server, provided by the *note xmlrpclib:
     134. and *note SimpleXMLRPCServer: 135. modules, have improved
     performance by supporting HTTP/1.1 keep-alive and by optionally
     using gzip encoding to compress the XML being exchanged.  The gzip
     compression is controlled by the ‘encode_threshold’ attribute of
     *note SimpleXMLRPCRequestHandler: 152f, which contains a size in
     bytes; responses larger than this will be compressed.  (Contributed
     by Kristján Valur Jónsson; bpo-6267(92).)

   * The *note zipfile: 137. module’s *note ZipFile: 8d4. now supports
     the context management protocol, so you can write ‘with
     zipfile.ZipFile(...) as f:’.  (Contributed by Brian Curtin;
     bpo-5511(93).)

     *note zipfile: 137. now also supports archiving empty directories
     and extracts them correctly.  (Fixed by Kuba Wieczorek;
     bpo-4710(94).)  Reading files out of an archive is faster, and
     interleaving *note read(): 1530. and *note readline(): 1531. now
     works correctly.  (Contributed by Nir Aides; bpo-7610(95).)

     The *note is_zipfile(): 1532. function now accepts a file object,
     in addition to the path names accepted in earlier versions.
     (Contributed by Gabriel Genellina; bpo-4756(96).)

     The *note writestr(): 2cc. method now has an optional
     'compress_type' parameter that lets you override the default
     compression method specified in the *note ZipFile: 8d4.
     constructor.  (Contributed by Ronald Oussoren; bpo-6003(97).)

* Menu:

* New module; importlib: New module importlib.
* New module; sysconfig: New module sysconfig.
* ttk; Themed Widgets for Tk: ttk Themed Widgets for Tk.
* Updated module; unittest: Updated module unittest.
* Updated module; ElementTree 1.3: Updated module ElementTree 1 3.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5142

   (2) https://bugs.python.org/issue?@action=redirect&bpo=7703

   (3) https://www.jcea.es/programacion/pybsddb.htm

   (4) https://bugs.python.org/issue?@action=redirect&bpo=8156

   (5) https://bugs.python.org/issue?@action=redirect&bpo=3860

   (6) https://bugs.python.org/issue?@action=redirect&bpo=1696199

   (7) https://bugs.python.org/issue?@action=redirect&bpo=1818

   (8) https://bugs.python.org/issue?@action=redirect&bpo=8729

   (9) https://bugs.python.org/issue?@action=redirect&bpo=7005

   (10) https://bugs.python.org/issue?@action=redirect&bpo=3924

   (11) https://bugs.python.org/issue?@action=redirect&bpo=1515

   (12) https://bugs.python.org/issue?@action=redirect&bpo=4606

   (13) https://sourceware.org/libffi/

   (14) https://bugs.python.org/issue?@action=redirect&bpo=8142

   (15) https://bugs.python.org/issue?@action=redirect&bpo=5788

   (16) https://bugs.python.org/issue?@action=redirect&bpo=4796

   (17) https://bugs.python.org/issue?@action=redirect&bpo=2531

   (18) https://bugs.python.org/issue?@action=redirect&bpo=8257

   (19) https://bugs.python.org/issue?@action=redirect&bpo=6595

   (20) https://bugs.python.org/issue?@action=redirect&bpo=7633

   (21) https://bugs.python.org/issue?@action=redirect&bpo=6857

   (22) https://bugs.python.org/issue?@action=redirect&bpo=7279

   (23) https://bugs.python.org/issue?@action=redirect&bpo=7585

   (24) https://bugs.python.org/issue?@action=redirect&bpo=8688

   (25) https://bugs.python.org/issue?@action=redirect&bpo=7490

   (26) https://bugs.python.org/issue?@action=redirect&bpo=1368247

   (27) https://bugs.python.org/issue?@action=redirect&bpo=5812

   (28) https://bugs.python.org/issue?@action=redirect&bpo=8294

   (29) https://bugs.python.org/issue?@action=redirect&bpo=2054

   (30) https://bugs.python.org/issue?@action=redirect&bpo=6845

   (31) https://bugs.python.org/issue?@action=redirect&bpo=5479

   (32) https://bugs.python.org/issue?@action=redirect&bpo=4688

   (33) https://bugs.python.org/issue?@action=redirect&bpo=3860

   (34) https://bugs.python.org/issue?@action=redirect&bpo=7471

   (35) https://bugs.python.org/issue?@action=redirect&bpo=4272

   (36) https://bugs.python.org/issue?@action=redirect&bpo=2846

   (37) https://bugs.python.org/issue?@action=redirect&bpo=7418

   (38) https://bugs.python.org/issue?@action=redirect&bpo=4879

   (39) https://bugs.python.org/issue?@action=redirect&bpo=3972

   (40) https://bugs.python.org/issue?@action=redirect&bpo=1655

   (41) https://bugs.python.org/issue?@action=redirect&bpo=3135

   (42) https://bugs.python.org/issue?@action=redirect&bpo=4991

   (43) https://bugs.python.org/issue?@action=redirect&bpo=6939

   (44) https://bugs.python.org/issue?@action=redirect&bpo=5032

   (45) https://bugs.python.org/issue?@action=redirect&bpo=4816

   (46) https://bugs.python.org/issue?@action=redirect&bpo=4136

   (47) https://bugs.python.org/issue?@action=redirect&bpo=5381

   (48) https://bugs.python.org/issue?@action=redirect&bpo=1607951

   (49) https://bugs.python.org/issue?@action=redirect&bpo=6896

   (50) https://bugs.python.org/issue?@action=redirect&bpo=3366

   (51) https://bugs.python.org/issue?@action=redirect&bpo=5585

   (52) https://bugs.python.org/issue?@action=redirect&bpo=6963

   (53) https://bugs.python.org/issue?@action=redirect&bpo=1664

   (54) https://bugs.python.org/issue?@action=redirect&bpo=6508

   (55) https://bugs.python.org/issue?@action=redirect&bpo=7333

   (56) https://bugs.python.org/issue?@action=redirect&bpo=7242

   (57) https://bugs.python.org/issue?@action=redirect&bpo=5827

   (58) https://bugs.python.org/issue?@action=redirect&bpo=3426

   (59) https://bugs.python.org/issue?@action=redirect&bpo=4739

   (60) https://bugs.python.org/issue?@action=redirect&bpo=6816

   (61) https://bugs.python.org/issue?@action=redirect&bpo=3002

   (62) https://bugs.python.org/issue?@action=redirect&bpo=8354

   (63) https://bugs.python.org/issue?@action=redirect&bpo=6693

   (64) https://bugs.python.org/issue?@action=redirect&bpo=3137

   (65) https://bugs.python.org/issue?@action=redirect&bpo=3972

   (66) https://bugs.python.org/issue?@action=redirect&bpo=8104

   (67) https://bugs.python.org/issue?@action=redirect&bpo=6192

   (68) https://bugs.python.org/issue?@action=redirect&bpo=6267

   (69) https://github.com/ghaering/pysqlite

   (70) https://bugs.python.org/issue?@action=redirect&bpo=7133

   (71) https://bugs.python.org/issue?@action=redirect&bpo=8222

   (72) https://docs.openssl.org/1.0.2/man1/ciphers/

   (73) https://bugs.python.org/issue?@action=redirect&bpo=8322

   (74) https://bugs.python.org/issue?@action=redirect&bpo=8484

   (75) https://bugs.python.org/issue?@action=redirect&bpo=8321

   (76) https://bugs.python.org/issue?@action=redirect&bpo=1523

   (77) https://bugs.python.org/issue?@action=redirect&bpo=8300

   (78) https://bugs.python.org/issue?@action=redirect&bpo=1068268

   (79) https://bugs.python.org/issue?@action=redirect&bpo=8451

   (80) https://bugs.python.org/issue?@action=redirect&bpo=4285

   (81) https://bugs.python.org/issue?@action=redirect&bpo=7766

   (82) https://bugs.python.org/issue?@action=redirect&bpo=7357

   (83) https://bugs.python.org/issue?@action=redirect&bpo=6856

   (84) https://bugs.python.org/issue?@action=redirect&bpo=7232

   (85) https://bugs.python.org/issue?@action=redirect&bpo=1674032

   (86) https://bugs.python.org/issue?@action=redirect&bpo=1571184

   (87) https://bugs.python.org/issue?@action=redirect&bpo=8024

   (88) https://datatracker.ietf.org/doc/html/rfc3986.html

   (89) https://datatracker.ietf.org/doc/html/rfc2732.html

   (90) https://bugs.python.org/issue?@action=redirect&bpo=2987

   (91) https://bugs.python.org/issue?@action=redirect&bpo=2746

   (92) https://bugs.python.org/issue?@action=redirect&bpo=6267

   (93) https://bugs.python.org/issue?@action=redirect&bpo=5511

   (94) https://bugs.python.org/issue?@action=redirect&bpo=4710

   (95) https://bugs.python.org/issue?@action=redirect&bpo=7610

   (96) https://bugs.python.org/issue?@action=redirect&bpo=4756

   (97) https://bugs.python.org/issue?@action=redirect&bpo=6003


File: python.info,  Node: New module importlib,  Next: New module sysconfig,  Up: New and Improved Modules

1.16.11.1 New module: importlib
...............................

Python 3.1 includes the *note importlib: 7b. package, a
re-implementation of the logic underlying Python’s *note import: 7f9.
statement.  *note importlib: 7b. is useful for implementers of Python
interpreters and to users who wish to write new importers that can
participate in the import process.  Python 2.7 doesn’t contain the
complete *note importlib: 7b. package, but instead has a tiny subset
that contains a single function, *note import_module(): 73d.

‘import_module(name, package=None)’ imports a module.  'name' is a
string containing the module or package’s name.  It’s possible to do
relative imports by providing a string that begins with a ‘.’ character,
such as ‘..utils.errors’.  For relative imports, the 'package' argument
must be provided and is the name of the package that will be used as the
anchor for the relative import.  *note import_module(): 73d. both
inserts the imported module into ‘sys.modules’ and returns the module
object.

Here are some examples:

     >>> from importlib import import_module
     >>> anydbm = import_module('anydbm')  # Standard absolute import
     >>> anydbm
     <module 'anydbm' from '/p/python/Lib/anydbm.py'>
     >>> # Relative import
     >>> file_util = import_module('..file_util', 'distutils.command')
     >>> file_util
     <module 'distutils.file_util' from '/python/Lib/distutils/file_util.pyc'>

*note importlib: 7b. was implemented by Brett Cannon and introduced in
Python 3.1.


File: python.info,  Node: New module sysconfig,  Next: ttk Themed Widgets for Tk,  Prev: New module importlib,  Up: New and Improved Modules

1.16.11.2 New module: sysconfig
...............................

The *note sysconfig: e1. module has been pulled out of the Distutils
package, becoming a new top-level module in its own right.  *note
sysconfig: e1. provides functions for getting information about Python’s
build process: compiler switches, installation paths, the platform name,
and whether Python is running from its source directory.

Some of the functions in the module are:

   * *note get_config_var(): 174. returns variables from Python’s
     Makefile and the ‘pyconfig.h’ file.

   * *note get_config_vars(): 298. returns a dictionary containing all
     of the configuration variables.

   * *note get_path(): 1535. returns the configured path for a
     particular type of module: the standard library, site-specific
     modules, platform-specific modules, etc.

   * *note is_python_build(): 32d. returns true if you’re running a
     binary from a Python source tree, and false otherwise.

Consult the *note sysconfig: e1. documentation for more details and for
a complete list of functions.

The Distutils package and *note sysconfig: e1. are now maintained by
Tarek Ziadé, who has also started a Distutils2 package (source
repository at ‘https://hg.python.org/distutils2/’) for developing a
next-generation version of Distutils.


File: python.info,  Node: ttk Themed Widgets for Tk,  Next: Updated module unittest,  Prev: New module sysconfig,  Up: New and Improved Modules

1.16.11.3 ttk: Themed Widgets for Tk
....................................

Tcl/Tk 8.5 includes a set of themed widgets that re-implement basic Tk
widgets but have a more customizable appearance and can therefore more
closely resemble the native platform’s widgets.  This widget set was
originally called Tile, but was renamed to Ttk (for «themed Tk») on
being added to Tcl/Tck release 8.5.

To learn more, read the *note ttk: ff. module documentation.  You may
also wish to read the Tcl/Tk manual page describing the Ttk theme
engine, available at
‘https://www.tcl.tk/man/tcl8.5/TkCmd/ttk_intro.html’.  Some screenshots
of the Python/Ttk code in use are at
‘https://code.google.com/archive/p/python-ttk/wikis/Screenshots.wiki’.

The *note tkinter.ttk: ff. module was written by Guilherme Polo and
added in bpo-2983(1).  An alternate version called ‘Tile.py’, written by
Martin Franklin and maintained by Kevin Walzer, was proposed for
inclusion in bpo-2618(2), but the authors argued that Guilherme Polo’s
work was more comprehensive.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=2983

   (2) https://bugs.python.org/issue?@action=redirect&bpo=2618


File: python.info,  Node: Updated module unittest,  Next: Updated module ElementTree 1 3,  Prev: ttk Themed Widgets for Tk,  Up: New and Improved Modules

1.16.11.4 Updated module: unittest
..................................

The *note unittest: 10c. module was greatly enhanced; many new features
were added.  Most of these features were implemented by Michael Foord,
unless otherwise noted.  The enhanced version of the module is
downloadable separately for use with Python versions 2.4 to 2.6,
packaged as the ‘unittest2’ package, from unittest2(1).

When used from the command line, the module can automatically discover
tests.  It’s not as fancy as py.test(2) or nose(3), but provides a
simple way to run tests kept within a set of package directories.  For
example, the following command will search the ‘test/’ subdirectory for
any importable test files named ‘test*.py’:

     python -m unittest discover -s test

Consult the *note unittest: 10c. module documentation for more details.
(Developed in bpo-6001(4).)

The *note main(): 11e5. function supports some other new options:

   * *note -b: 1539. or ‘--buffer’ will buffer the standard output and
     standard error streams during each test.  If the test passes, any
     resulting output will be discarded; on failure, the buffered output
     will be displayed.

   * *note -c: 153a. or ‘--catch’ will cause the control-C interrupt to
     be handled more gracefully.  Instead of interrupting the test
     process immediately, the currently running test will be completed
     and then the partial results up to the interruption will be
     reported.  If you’re impatient, a second press of control-C will
     cause an immediate interruption.

     This control-C handler tries to avoid causing problems when the
     code being tested or the tests being run have defined a signal
     handler of their own, by noticing that a signal handler was already
     set and calling it.  If this doesn’t work for you, there’s a *note
     removeHandler(): 153b. decorator that can be used to mark tests
     that should have the control-C handling disabled.

   * *note -f: 153c. or ‘--failfast’ makes test execution stop
     immediately when a test fails instead of continuing to execute
     further tests.  (Suggested by Cliff Dyer and implemented by Michael
     Foord; bpo-8074(5).)

The progress messages now show “x” for expected failures and “u” for
unexpected successes when run in verbose mode.  (Contributed by Benjamin
Peterson.)

Test cases can raise the *note SkipTest: 11e6. exception to skip a test
(bpo-1034053(6)).

The error messages for *note assertEqual(): 74d, *note assertTrue():
74b, and *note assertFalse(): 74c. failures now provide more
information.  If you set the *note longMessage: 153d. attribute of your
*note TestCase: 2b3. classes to true, both the standard error message
and any additional message you provide will be printed for failures.
(Added by Michael Foord; bpo-5663(7).)

The *note assertRaises(): 751. method now returns a context handler when
called without providing a callable object to run.  For example, you can
write this:

     with self.assertRaises(KeyError):
         {}['foo']

(Implemented by Antoine Pitrou; bpo-4444(8).)

Module- and class-level setup and teardown fixtures are now supported.
Modules can contain *note setUpModule(): c44. and *note
tearDownModule(): 153e. functions.  Classes can have *note setUpClass():
c45. and *note tearDownClass(): 153f. methods that must be defined as
class methods (using ‘@classmethod’ or equivalent).  These functions and
methods are invoked when the test runner switches to a test case in a
different module or class.

The methods *note addCleanup(): c76. and *note doCleanups(): 1540. were
added.  *note addCleanup(): c76. lets you add cleanup functions that
will be called unconditionally (after *note setUp(): 1541. if *note
setUp(): 1541. fails, otherwise after *note tearDown(): 1542.).  This
allows for much simpler resource allocation and deallocation during
tests (bpo-5679(9)).

A number of new methods were added that provide more specialized tests.
Many of these methods were written by Google engineers for use in their
test suites; Gregory P. Smith, Michael Foord, and GvR worked on merging
them into Python’s version of *note unittest: 10c.

   * *note assertIsNone(): 1492. and *note assertIsNotNone(): 1493. take
     one expression and verify that the result is or is not ‘None’.

   * *note assertIs(): 1543. and *note assertIsNot(): 1544. take two
     values and check whether the two values evaluate to the same object
     or not.  (Added by Michael Foord; bpo-2578(10).)

   * *note assertIsInstance(): 1545. and *note assertNotIsInstance():
     1546. check whether the resulting object is an instance of a
     particular class, or of one of a tuple of classes.  (Added by Georg
     Brandl; bpo-7031(11).)

   * *note assertGreater(): 1547, *note assertGreaterEqual(): 1548,
     *note assertLess(): 1549, and *note assertLessEqual(): 154a.
     compare two quantities.

   * *note assertMultiLineEqual(): 154b. compares two strings, and if
     they’re not equal, displays a helpful comparison that highlights
     the differences in the two strings.  This comparison is now used by
     default when Unicode strings are compared with *note assertEqual():
     74d.

   * *note assertRegexpMatches(): 752. and *note
     assertNotRegexpMatches(): 754. checks whether the first argument is
     a string matching or not matching the regular expression provided
     as the second argument (bpo-8038(12)).

   * *note assertRaisesRegexp(): 753. checks whether a particular
     exception is raised, and then also checks that the string
     representation of the exception matches the provided regular
     expression.

   * *note assertIn(): 154c. and *note assertNotIn(): 154d. tests
     whether 'first' is or is not in 'second'.

   * *note assertItemsEqual(): 1432. tests whether two provided
     sequences contain the same elements.

   * *note assertSetEqual(): 148d. compares whether two sets are equal,
     and only reports the differences between the sets in case of error.

   * Similarly, *note assertListEqual(): 148f. and *note
     assertTupleEqual(): 1490. compare the specified types and explain
     any differences without necessarily printing their full values;
     these methods are now used by default when comparing lists and
     tuples using *note assertEqual(): 74d.  More generally, *note
     assertSequenceEqual(): 1491. compares two sequences and can
     optionally check whether both sequences are of a particular type.

   * *note assertDictEqual(): 148e. compares two dictionaries and
     reports the differences; it’s now used by default when you compare
     two dictionaries using *note assertEqual(): 74d.
     ‘assertDictContainsSubset()’ checks whether all of the key/value
     pairs in 'first' are found in 'second'.

   * *note assertAlmostEqual(): 74f. and *note assertNotAlmostEqual():
     750. test whether 'first' and 'second' are approximately equal.
     This method can either round their difference to an optionally
     specified number of 'places' (the default is 7) and compare it to
     zero, or require the difference to be smaller than a supplied
     'delta' value.

   * *note loadTestsFromName(): 154e. properly honors the *note
     suiteClass: 154f. attribute of the *note TestLoader: 593.  (Fixed
     by Mark Roddy; bpo-6866(13).)

   * A new hook lets you extend the *note assertEqual(): 74d. method to
     handle new data types.  The *note addTypeEqualityFunc(): 1550.
     method takes a type object and a function.  The function will be
     used when both of the objects being compared are of the specified
     type.  This function should compare the two objects and raise an
     exception if they don’t match; it’s a good idea for the function to
     provide additional information about why the two objects aren’t
     matching, much as the new sequence comparison methods do.

*note unittest.main(): 11e5. now takes an optional ‘exit’ argument.  If
false, *note main(): 11e5. doesn’t call *note sys.exit(): 277, allowing
*note main(): 11e5. to be used from the interactive interpreter.
(Contributed by J. Pablo Fernández; bpo-3379(14).)

*note TestResult: 136f. has new *note startTestRun(): 1551. and *note
stopTestRun(): 1552. methods that are called immediately before and
after a test run.  (Contributed by Robert Collins; bpo-5728(15).)

With all these changes, the ‘unittest.py’ was becoming awkwardly large,
so the module was turned into a package and the code split into several
files (by Benjamin Peterson).  This doesn’t affect how the module is
imported or used.

Vedi anche
..........

‘https://web.archive.org/web/20210619163128/http://www.voidspace.org.uk/python/articles/unittest2.shtml’

     Describes the new features, how to use them, and the rationale for
     various design decisions.  (By Michael Foord.)

   ---------- Footnotes ----------

   (1) https://pypi.org/project/unittest2/

   (2) https://pytest.org

   (3) https://nose.readthedocs.io/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=6001

   (5) https://bugs.python.org/issue?@action=redirect&bpo=8074

   (6) https://bugs.python.org/issue?@action=redirect&bpo=1034053

   (7) https://bugs.python.org/issue?@action=redirect&bpo=5663

   (8) https://bugs.python.org/issue?@action=redirect&bpo=4444

   (9) https://bugs.python.org/issue?@action=redirect&bpo=5679

   (10) https://bugs.python.org/issue?@action=redirect&bpo=2578

   (11) https://bugs.python.org/issue?@action=redirect&bpo=7031

   (12) https://bugs.python.org/issue?@action=redirect&bpo=8038

   (13) https://bugs.python.org/issue?@action=redirect&bpo=6866

   (14) https://bugs.python.org/issue?@action=redirect&bpo=3379

   (15) https://bugs.python.org/issue?@action=redirect&bpo=5728


File: python.info,  Node: Updated module ElementTree 1 3,  Prev: Updated module unittest,  Up: New and Improved Modules

1.16.11.5 Updated module: ElementTree 1.3
.........................................

The version of the ElementTree library included with Python was updated
to version 1.3.  Some of the new features are:

   * The various parsing functions now take a 'parser' keyword argument
     giving an *note XMLParser: c4b. instance that will be used.  This
     makes it possible to override the file’s internal encoding:

          p = ET.XMLParser(encoding='utf-8')
          t = ET.XML("""<root/>""", parser=p)

     Errors in parsing XML now raise a *note ParseError: 147f.
     exception, whose instances have a ‘position’ attribute containing a
     ('line', 'column') tuple giving the location of the problem.

   * ElementTree’s code for converting trees to a string has been
     significantly reworked, making it roughly twice as fast in many
     cases.  The *note ElementTree.write(): c8e. and ‘Element.write()’
     methods now have a 'method' parameter that can be «xml» (the
     default), «html», or «text».  HTML mode will output empty elements
     as ‘<empty></empty>’ instead of ‘<empty/>’, and text mode will skip
     over elements and only output the text chunks.  If you set the
     *note tag: 1555. attribute of an element to ‘None’ but leave its
     children in place, the element will be omitted when the tree is
     written out, so you don’t need to do more extensive rearrangement
     to remove a single element.

     Namespace handling has also been improved.  All ‘xmlns:<whatever>’
     declarations are now output on the root element, not scattered
     throughout the resulting XML. You can set the default namespace for
     a tree by setting the ‘default_namespace’ attribute and can
     register new prefixes with *note register_namespace(): 13da.  In
     XML mode, you can use the true/false 'xml_declaration' parameter to
     suppress the XML declaration.

   * New *note Element: 363. method: *note extend(): 13db. appends the
     items from a sequence to the element’s children.  Elements
     themselves behave like sequences, so it’s easy to move children
     from one element to another:

          from xml.etree import ElementTree as ET

          t = ET.XML("""<list>
            <item>1</item> <item>2</item>  <item>3</item>
          </list>""")
          new = ET.XML('<root/>')
          new.extend(t)

          # Outputs <root><item>1</item>...</root>
          print ET.tostring(new)

   * New *note Element: 363. method: *note iter(): 1556. yields the
     children of the element as a generator.  It’s also possible to
     write ‘for child in elem:’ to loop over an element’s children.  The
     existing method ‘getiterator()’ is now deprecated, as is
     ‘getchildren()’ which constructs and returns a list of children.

   * New *note Element: 363. method: *note itertext(): 13dd. yields all
     chunks of text that are descendants of the element.  For example:

          t = ET.XML("""<list>
            <item>1</item> <item>2</item>  <item>3</item>
          </list>""")

          # Outputs ['\n  ', '1', ' ', '2', '  ', '3', '\n']
          print list(t.itertext())

   * Deprecated: using an element as a Boolean (i.e., ‘if elem:’) would
     return true if the element had any children, or false if there were
     no children.  This behaviour is confusing – ‘None’ is false, but so
     is a childless element?  – so it will now trigger a *note
     FutureWarning: 659.  In your code, you should be explicit: write
     ‘len(elem) != 0’ if you’re interested in the number of children, or
     ‘elem is not None’.

Fredrik Lundh develops ElementTree and produced the 1.3 version; you can
read his article describing 1.3 at
‘https://web.archive.org/web/20200703234532/http://effbot.org/zone/elementtree-13-intro.htm’.
Florent Xicluna updated the version included with Python, after
discussions on python-dev and in bpo-6472(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=6472


File: python.info,  Node: Build and C API Changes<8>,  Next: Other Changes and Fixes,  Prev: New and Improved Modules,  Up: What’s New in Python 2 7

1.16.12 Build and C API Changes
-------------------------------

Changes to Python’s build process and to the C API include:

   * The latest release of the GNU Debugger, GDB 7, can be scripted
     using Python(1).  When you begin debugging an executable program P,
     GDB will look for a file named ‘P-gdb.py’ and automatically read
     it.  Dave Malcolm contributed a ‘python-gdb.py’ that adds a number
     of commands useful when debugging Python itself.  For example,
     ‘py-up’ and ‘py-down’ go up or down one Python stack frame, which
     usually corresponds to several C stack frames.  ‘py-print’ prints
     the value of a Python variable, and ‘py-bt’ prints the Python stack
     trace.  (Added as a result of bpo-8032(2).)

   * If you use the ‘.gdbinit’ file provided with Python, the «pyo»
     macro in the 2.7 version now works correctly when the thread being
     debugged doesn’t hold the GIL; the macro now acquires it before
     printing.  (Contributed by Victor Stinner; bpo-3632(3).)

   * *note Py_AddPendingCall(): b7a. is now thread-safe, letting any
     worker thread submit notifications to the main Python thread.  This
     is particularly useful for asynchronous IO operations.
     (Contributed by Kristján Valur Jónsson; bpo-4293(4).)

   * New function: *note PyCode_NewEmpty(): 1558. creates an empty code
     object; only the filename, function name, and first line number are
     required.  This is useful for extension modules that are attempting
     to construct a more useful traceback stack.  Previously such
     extensions needed to call ‘PyCode_New()’, which had many more
     arguments.  (Added by Jeffrey Yasskin.)

   * New function: *note PyErr_NewExceptionWithDoc(): 1470. creates a
     new exception class, just as the existing *note
     PyErr_NewException(): 1471. does, but takes an extra ‘char *’
     argument containing the docstring for the new exception class.
     (Added by “lekma” on the Python bug tracker; bpo-7033(5).)

   * New function: *note PyFrame_GetLineNumber(): 98f. takes a frame
     object and returns the line number that the frame is currently
     executing.  Previously code would need to get the index of the
     bytecode instruction currently executing, and then look up the line
     number corresponding to that address.  (Added by Jeffrey Yasskin.)

   * New functions: *note PyLong_AsLongAndOverflow(): 146e. and *note
     PyLong_AsLongLongAndOverflow(): 146d. approximates a Python long
     integer as a C long or long long.  If the number is too large to
     fit into the output type, an 'overflow' flag is set and returned to
     the caller.  (Contributed by Case Van Horsen; bpo-7528(6) and
     bpo-7767(7).)

   * New function: stemming from the rewrite of string-to-float
     conversion, a new *note PyOS_string_to_double(): 149d. function was
     added.  The old ‘PyOS_ascii_strtod()’ and ‘PyOS_ascii_atof()’
     functions are now deprecated.

   * New function: ‘PySys_SetArgvEx()’ sets the value of ‘sys.argv’ and
     can optionally update ‘sys.path’ to include the directory
     containing the script named by ‘sys.argv[0]’ depending on the value
     of an 'updatepath' parameter.

     This function was added to close a security hole for applications
     that embed Python.  The old function, ‘PySys_SetArgv()’, would
     always update ‘sys.path’, and sometimes it would add the current
     directory.  This meant that, if you ran an application embedding
     Python in a directory controlled by someone else, attackers could
     put a Trojan-horse module in the directory (say, a file named
     ‘os.py’) that your application would then import and run.

     If you maintain a C/C++ application that embeds Python, check
     whether you’re calling ‘PySys_SetArgv()’ and carefully consider
     whether the application should be using ‘PySys_SetArgvEx()’ with
     'updatepath' set to false.

     Security issue reported as CVE 2008-5983(8); discussed in
     bpo-5753(9), and fixed by Antoine Pitrou.

   * New macros: the Python header files now define the following
     macros: *note Py_ISALNUM: 1559, *note Py_ISALPHA: 155a, *note
     Py_ISDIGIT: 155b, *note Py_ISLOWER: 155c, *note Py_ISSPACE: 155d,
     *note Py_ISUPPER: 155e, *note Py_ISXDIGIT: 155f, *note Py_TOLOWER:
     1560, and *note Py_TOUPPER: 1561.  All of these functions are
     analogous to the C standard macros for classifying characters, but
     ignore the current locale setting, because in several places Python
     needs to analyze characters in a locale-independent way.  (Added by
     Eric Smith; bpo-5793(10).)

   * Removed function: ‘PyEval_CallObject()’ is now only available as a
     macro.  A function version was being kept around to preserve ABI
     linking compatibility, but that was in 1997; it can certainly be
     deleted by now.  (Removed by Antoine Pitrou; bpo-8276(11).)

   * New format codes: the ‘PyString_FromFormat()’,
     ‘PyString_FromFormatV()’, and *note PyErr_Format(): 10b3. functions
     now accept ‘%lld’ and ‘%llu’ format codes for displaying C’s long
     long types.  (Contributed by Mark Dickinson; bpo-7228(12).)

   * The complicated interaction between threads and process forking has
     been changed.  Previously, the child process created by *note
     os.fork(): 4b6. might fail because the child is created with only a
     single thread running, the thread performing the *note os.fork():
     4b6.  If other threads were holding a lock, such as Python’s import
     lock, when the fork was performed, the lock would still be marked
     as «held» in the new process.  But in the child process nothing
     would ever release the lock, since the other threads weren’t
     replicated, and the child process would no longer be able to
     perform imports.

     Python 2.7 acquires the import lock before performing an *note
     os.fork(): 4b6, and will also clean up any locks created using the
     *note threading: f3. module.  C extension modules that have
     internal locks, or that call ‘fork()’ themselves, will not benefit
     from this clean-up.

     (Fixed by Thomas Wouters; bpo-1590864(13).)

   * The *note Py_Finalize(): 45f. function now calls the internal
     ‘threading._shutdown()’ function; this prevents some exceptions
     from being raised when an interpreter shuts down.  (Patch by Adam
     Olsen; bpo-1722344(14).)

   * When using the *note PyMemberDef: 772. structure to define
     attributes of a type, Python will no longer let you try to delete
     or set a ‘T_STRING_INPLACE’ attribute.

   * Global symbols defined by the *note ctypes: 2e. module are now
     prefixed with ‘Py’, or with ‘_ctypes’.  (Implemented by Thomas
     Heller; bpo-3102(15).)

   * New configure option: the ‘--with-system-expat’ switch allows
     building the *note pyexpat: 12c. module to use the system Expat
     library.  (Contributed by Arfrever Frehtes Taifersar Arahesis;
     bpo-7609(16).)

   * New configure option: the ‘--with-valgrind’ option will now disable
     the pymalloc allocator, which is difficult for the Valgrind
     memory-error detector to analyze correctly.  Valgrind will
     therefore be better at detecting memory leaks and overruns.
     (Contributed by James Henstridge; bpo-2422(17).)

   * New configure option: you can now supply an empty string to
     ‘--with-dbmliborder=’ in order to disable all of the various DBM
     modules.  (Added by Arfrever Frehtes Taifersar Arahesis;
     bpo-6491(18).)

   * The ‘configure’ script now checks for floating-point rounding bugs
     on certain 32-bit Intel chips and defines a ‘X87_DOUBLE_ROUNDING’
     preprocessor definition.  No code currently uses this definition,
     but it’s available if anyone wishes to use it.  (Added by Mark
     Dickinson; bpo-2937(19).)

     ‘configure’ also now sets a ‘LDCXXSHARED’ Makefile variable for
     supporting C++ linking.  (Contributed by Arfrever Frehtes Taifersar
     Arahesis; bpo-1222585(20).)

   * The build process now creates the necessary files for pkg-config
     support.  (Contributed by Clinton Roy; bpo-3585(21).)

   * The build process now supports Subversion 1.7.  (Contributed by
     Arfrever Frehtes Taifersar Arahesis; bpo-6094(22).)

* Menu:

* Capsules::
* Port-Specific Changes; Windows: Port-Specific Changes Windows.
* Port-Specific Changes; Mac OS X: Port-Specific Changes Mac OS X.
* Port-Specific Changes; FreeBSD: Port-Specific Changes FreeBSD.

   ---------- Footnotes ----------

   (1) 
https://web.archive.org/web/20110715084810/http://sourceware.org/gdb/current/onlinedocs/gdb/Python.html

   (2) https://bugs.python.org/issue?@action=redirect&bpo=8032

   (3) https://bugs.python.org/issue?@action=redirect&bpo=3632

   (4) https://bugs.python.org/issue?@action=redirect&bpo=4293

   (5) https://bugs.python.org/issue?@action=redirect&bpo=7033

   (6) https://bugs.python.org/issue?@action=redirect&bpo=7528

   (7) https://bugs.python.org/issue?@action=redirect&bpo=7767

   (8) https://www.cve.org/CVERecord?id=CVE-2008-5983

   (9) https://bugs.python.org/issue?@action=redirect&bpo=5753

   (10) https://bugs.python.org/issue?@action=redirect&bpo=5793

   (11) https://bugs.python.org/issue?@action=redirect&bpo=8276

   (12) https://bugs.python.org/issue?@action=redirect&bpo=7228

   (13) https://bugs.python.org/issue?@action=redirect&bpo=1590864

   (14) https://bugs.python.org/issue?@action=redirect&bpo=1722344

   (15) https://bugs.python.org/issue?@action=redirect&bpo=3102

   (16) https://bugs.python.org/issue?@action=redirect&bpo=7609

   (17) https://bugs.python.org/issue?@action=redirect&bpo=2422

   (18) https://bugs.python.org/issue?@action=redirect&bpo=6491

   (19) https://bugs.python.org/issue?@action=redirect&bpo=2937

   (20) https://bugs.python.org/issue?@action=redirect&bpo=1222585

   (21) https://bugs.python.org/issue?@action=redirect&bpo=3585

   (22) https://bugs.python.org/issue?@action=redirect&bpo=6094


File: python.info,  Node: Capsules,  Next: Port-Specific Changes Windows,  Up: Build and C API Changes<8>

1.16.12.1 Capsules
..................

Python 3.1 adds a new C datatype, *note PyCapsule: 147a, for providing a
C API to an extension module.  A capsule is essentially the holder of a
C ‘void *’ pointer, and is made available as a module attribute; for
example, the *note socket: d1. module’s API is exposed as ‘socket.CAPI’,
and *note unicodedata: 10b. exposes ‘ucnhash_CAPI’.  Other extensions
can import the module, access its dictionary to get the capsule object,
and then get the ‘void *’ pointer, which will usually point to an array
of pointers to the module’s various API functions.

There is an existing data type already used for this, ‘PyCObject’, but
it doesn’t provide type safety.  Evil code written in pure Python could
cause a segmentation fault by taking a ‘PyCObject’ from module A and
somehow substituting it for the ‘PyCObject’ in module B. Capsules know
their own name, and getting the pointer requires providing the name:

     void *vtable;

     if (!PyCapsule_IsValid(capsule, "mymodule.CAPI") {
             PyErr_SetString(PyExc_ValueError, "argument type invalid");
             return NULL;
     }

     vtable = PyCapsule_GetPointer(capsule, "mymodule.CAPI");

You are assured that ‘vtable’ points to whatever you’re expecting.  If a
different capsule was passed in, *note PyCapsule_IsValid(): 1564. would
detect the mismatched name and return false.  Refer to *note Providing a
C API for an Extension Module: 1565. for more information on using these
objects.

Python 2.7 now uses capsules internally to provide various
extension-module APIs, but the ‘PyCObject_AsVoidPtr()’ was modified to
handle capsules, preserving compile-time compatibility with the
‘PyCObject’ interface.  Use of ‘PyCObject_AsVoidPtr()’ will signal a
*note PendingDeprecationWarning: ac8, which is silent by default.

Implemented in Python 3.1 and backported to 2.7 by Larry Hastings;
discussed in bpo-5630(1).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5630


File: python.info,  Node: Port-Specific Changes Windows,  Next: Port-Specific Changes Mac OS X,  Prev: Capsules,  Up: Build and C API Changes<8>

1.16.12.2 Port-Specific Changes: Windows
........................................

   * The *note msvcrt: 97. module now contains some constants from the
     ‘crtassem.h’ header file: *note CRT_ASSEMBLY_VERSION: 1567, *note
     VC_ASSEMBLY_PUBLICKEYTOKEN: 1568, and *note
     LIBRARIES_ASSEMBLY_NAME_PREFIX: 1569.  (Contributed by David
     Cournapeau; bpo-4365(1).)

   * The *note _winreg: 11c. module for accessing the registry now
     implements the *note CreateKeyEx(): 156a. and *note DeleteKeyEx():
     156b. functions, extended versions of previously supported
     functions that take several extra arguments.  The *note
     DisableReflectionKey(): 156c, *note EnableReflectionKey(): 156d,
     and *note QueryReflectionKey(): 156e. were also tested and
     documented.  (Implemented by Brian Curtin: bpo-7347(2).)

   * The new ‘_beginthreadex()’ API is used to start threads, and the
     native thread-local storage functions are now used.  (Contributed
     by Kristján Valur Jónsson; bpo-3582(3).)

   * The *note os.kill(): 156f. function now works on Windows.  The
     signal value can be the constants *note CTRL_C_EVENT: 1570, *note
     CTRL_BREAK_EVENT: 1571, or any integer.  The first two constants
     will send ‘Control’-‘C’ and ‘Control’-‘Break’ keystroke events to
     subprocesses; any other value will use the ‘TerminateProcess()’
     API.  (Contributed by Miki Tebeka; bpo-1220212(4).)

   * The *note os.listdir(): 1302. function now correctly fails for an
     empty path.  (Fixed by Hirokazu Yamamoto; bpo-5913(5).)

   * The *note mimetypes: 93. module will now read the MIME database
     from the Windows registry when initializing.  (Patch by Gabriel
     Genellina; bpo-4969(6).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4365

   (2) https://bugs.python.org/issue?@action=redirect&bpo=7347

   (3) https://bugs.python.org/issue?@action=redirect&bpo=3582

   (4) https://bugs.python.org/issue?@action=redirect&bpo=1220212

   (5) https://bugs.python.org/issue?@action=redirect&bpo=5913

   (6) https://bugs.python.org/issue?@action=redirect&bpo=4969


File: python.info,  Node: Port-Specific Changes Mac OS X,  Next: Port-Specific Changes FreeBSD,  Prev: Port-Specific Changes Windows,  Up: Build and C API Changes<8>

1.16.12.3 Port-Specific Changes: Mac OS X
.........................................

   * The path ‘/Library/Python/2.7/site-packages’ is now appended to
     ‘sys.path’, in order to share added packages between the system
     installation and a user-installed copy of the same version.
     (Changed by Ronald Oussoren; bpo-4865(1).)

     Cambiato nella versione 2.7.13: As of 2.7.13, this change was
     removed.  ‘/Library/Python/2.7/site-packages’, the site-packages
     directory used by the Apple-supplied system Python 2.7 is no longer
     appended to ‘sys.path’ for user-installed Pythons such as from the
     python.org installers.  As of macOS 10.12, Apple changed how the
     system site-packages directory is configured, which could cause
     installation of pip components, like setuptools, to fail.  Packages
     installed for the system Python will no longer be shared with
     user-installed Pythons.  (bpo-28440(2))

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=4865

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28440


File: python.info,  Node: Port-Specific Changes FreeBSD,  Prev: Port-Specific Changes Mac OS X,  Up: Build and C API Changes<8>

1.16.12.4 Port-Specific Changes: FreeBSD
........................................

   * FreeBSD 7.1’s ‘SO_SETFIB’ constant, used with the *note socket():
     fa3. methods *note getsockopt(): ed2./*note setsockopt(): ed3. to
     select an alternate routing table, is now available in the *note
     socket: d1. module.  (Added by Kyle VanderBeek; bpo-8235(1).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=8235


File: python.info,  Node: Other Changes and Fixes,  Next: Porting to Python 2 7,  Prev: Build and C API Changes<8>,  Up: What’s New in Python 2 7

1.16.13 Other Changes and Fixes
-------------------------------

   * Two benchmark scripts, ‘iobench’ and ‘ccbench’, were added to the
     ‘Tools’ directory.  ‘iobench’ measures the speed of the built-in
     file I/O objects returned by *note open(): 316. while performing
     various operations, and ‘ccbench’ is a concurrency benchmark that
     tries to measure computing throughput, thread switching latency,
     and IO processing bandwidth when performing several tasks using a
     varying number of threads.

   * The ‘Tools/i18n/msgfmt.py’ script now understands plural forms in
     ‘.po’ files.  (Fixed by Martin von Löwis; bpo-5464(1).)

   * When importing a module from a ‘.pyc’ or ‘.pyo’ file with an
     existing ‘.py’ counterpart, the *note co_filename: 1575. attributes
     of the resulting code objects are overwritten when the original
     filename is obsolete.  This can happen if the file has been
     renamed, moved, or is accessed through different paths.  (Patch by
     Ziga Seilnacht and Jean-Paul Calderone; bpo-1180193(2).)

   * The ‘regrtest.py’ script now takes a ‘--randseed=’ switch that
     takes an integer that will be used as the random seed for the ‘-r’
     option that executes tests in random order.  The ‘-r’ option also
     reports the seed that was used (Added by Collin Winter.)

   * Another ‘regrtest.py’ switch is ‘-j’, which takes an integer
     specifying how many tests run in parallel.  This allows reducing
     the total runtime on multi-core machines.  This option is
     compatible with several other options, including the ‘-R’ switch
     which is known to produce long runtimes.  (Added by Antoine Pitrou,
     bpo-6152(3).)  This can also be used with a new ‘-F’ switch that
     runs selected tests in a loop until they fail.  (Added by Antoine
     Pitrou; bpo-7312(4).)

   * When executed as a script, the ‘py_compile.py’ module now accepts
     ‘'-'’ as an argument, which will read standard input for the list
     of filenames to be compiled.  (Contributed by Piotr Ożarowski;
     bpo-8233(5).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5464

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1180193

   (3) https://bugs.python.org/issue?@action=redirect&bpo=6152

   (4) https://bugs.python.org/issue?@action=redirect&bpo=7312

   (5) https://bugs.python.org/issue?@action=redirect&bpo=8233


File: python.info,  Node: Porting to Python 2 7,  Next: New Features Added to Python 2 7 Maintenance Releases,  Prev: Other Changes and Fixes,  Up: What’s New in Python 2 7

1.16.14 Porting to Python 2.7
-----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code:

   * The *note range(): b3f. function processes its arguments more
     consistently; it will now call *note __int__(): 19d. on non-float,
     non-integer arguments that are supplied to it.  (Fixed by Alexander
     Belopolsky; bpo-1533(1).)

   * The string *note format(): 199. method changed the default
     precision used for floating-point and complex numbers from 6
     decimal places to 12, which matches the precision used by *note
     str(): 169.  (Changed by Eric Smith; bpo-5920(2).)

   * Because of an optimization for the *note with: 186. statement, the
     special methods *note __enter__(): 7e5. and *note __exit__(): 1508.
     must belong to the object’s type, and cannot be directly attached
     to the object’s instance.  This affects new-style classes (derived
     from *note object: c80.) and C extension types.  (bpo-6101(3).)

   * Due to a bug in Python 2.6, the 'exc_value' parameter to *note
     __exit__(): 1508. methods was often the string representation of
     the exception, not an instance.  This was fixed in 2.7, so
     'exc_value' will be an instance as expected.  (Fixed by Florent
     Xicluna; bpo-7853(4).)

   * When a restricted set of attributes were set using ‘__slots__’,
     deleting an unset attribute would not raise *note AttributeError:
     5f0. as you would expect.  Fixed by Benjamin Peterson;
     bpo-7604(5).)

In the standard library:

   * Operations with *note datetime: 4e3. instances that resulted in a
     year falling outside the supported range didn’t always raise *note
     OverflowError: a83.  Such errors are now checked more carefully and
     will now raise the exception.  (Reported by Mark Leander, patch by
     Anand B. Pillai and Alexander Belopolsky; bpo-7150(6).)

   * When using *note Decimal: 1fe. instances with a string’s *note
     format(): 199. method, the default alignment was previously
     left-alignment.  This has been changed to right-alignment, which
     might change the output of your programs.  (Changed by Mark
     Dickinson; bpo-6857(7).)

     Comparisons involving a signaling NaN value (or ‘sNAN’) now signal
     *note InvalidOperation: 12b0. instead of silently returning a true
     or false value depending on the comparison operator.  Quiet NaN
     values (or ‘NaN’) are now hashable.  (Fixed by Mark Dickinson;
     bpo-7279(8).)

   * The *note xml.etree.ElementTree: 12b. library no longer escapes
     ampersands and angle brackets when outputting an XML processing
     instruction (which looks like ‘<?xml-stylesheet href="#style1"?>’)
     or comment (which looks like ‘<!-- comment -->’).  (Patch by Neil
     Muller; bpo-2746(9).)

   * The ‘readline()’ method of *note StringIO: 112b. objects now does
     nothing when a negative length is requested, as other file-like
     objects do.  (bpo-7348(10)).

   * The *note syslog: e2. module will now use the value of
     ‘sys.argv[0]’ as the identifier instead of the previous default
     value of ‘'python'’.  (Changed by Sean Reifschneider;
     bpo-8451(11).)

   * The *note tarfile: e4. module’s default error handling has changed,
     to no longer suppress fatal errors.  The default error level was
     previously 0, which meant that errors would only result in a
     message being written to the debug log, but because the debug log
     is not activated by default, these errors go unnoticed.  The
     default error level is now 1, which raises an exception if there’s
     an error.  (Changed by Lars Gustäbel; bpo-7357(12).)

   * The *note urlparse: 110. module’s *note urlsplit(): f3c. now
     handles unknown URL schemes in a fashion compliant with RFC
     3986(13): if the URL is of the form ‘"<something>://..."’, the text
     before the ‘://’ is treated as the scheme, even if it’s a made-up
     scheme that the module doesn’t know about.  This change may break
     code that worked around the old behaviour.  For example, Python
     2.6.4 or 2.5 will return the following:

          >>> import urlparse
          >>> urlparse.urlsplit('invented://host/filename?query')
          ('invented', '', '//host/filename?query', '', '')

     Python 2.7 (and Python 2.6.5) will return:

          >>> import urlparse
          >>> urlparse.urlsplit('invented://host/filename?query')
          ('invented', 'host', '/filename?query', '', '')

     (Python 2.7 actually produces slightly different output, since it
     returns a named tuple instead of a standard tuple.)

For C extensions:

   * C extensions that use integer format codes with the ‘PyArg_Parse*’
     family of functions will now raise a *note TypeError: 198.
     exception instead of triggering a *note DeprecationWarning: 1a3.
     (bpo-5080(14)).

   * Use the new *note PyOS_string_to_double(): 149d. function instead
     of the old ‘PyOS_ascii_strtod()’ and ‘PyOS_ascii_atof()’ functions,
     which are now deprecated.

For applications that embed Python:

   * The ‘PySys_SetArgvEx()’ function was added, letting applications
     close a security hole when the existing ‘PySys_SetArgv()’ function
     was used.  Check whether you’re calling ‘PySys_SetArgv()’ and
     carefully consider whether the application should be using
     ‘PySys_SetArgvEx()’ with 'updatepath' set to false.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1533

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5920

   (3) https://bugs.python.org/issue?@action=redirect&bpo=6101

   (4) https://bugs.python.org/issue?@action=redirect&bpo=7853

   (5) https://bugs.python.org/issue?@action=redirect&bpo=7604

   (6) https://bugs.python.org/issue?@action=redirect&bpo=7150

   (7) https://bugs.python.org/issue?@action=redirect&bpo=6857

   (8) https://bugs.python.org/issue?@action=redirect&bpo=7279

   (9) https://bugs.python.org/issue?@action=redirect&bpo=2746

   (10) https://bugs.python.org/issue?@action=redirect&bpo=7348

   (11) https://bugs.python.org/issue?@action=redirect&bpo=8451

   (12) https://bugs.python.org/issue?@action=redirect&bpo=7357

   (13) https://datatracker.ietf.org/doc/html/rfc3986.html

   (14) https://bugs.python.org/issue?@action=redirect&bpo=5080


File: python.info,  Node: New Features Added to Python 2 7 Maintenance Releases,  Next: Acknowledgements,  Prev: Porting to Python 2 7,  Up: What’s New in Python 2 7

1.16.15 New Features Added to Python 2.7 Maintenance Releases
-------------------------------------------------------------

New features may be added to Python 2.7 maintenance releases when the
situation genuinely calls for it.  Any such additions must go through
the Python Enhancement Proposal process, and make a compelling case for
why they can’t be adequately addressed by either adding the new feature
solely to Python 3, or else by publishing it on the Python Package
Index.

In addition to the specific proposals listed below, there is a general
exemption allowing new ‘-3’ warnings to be added in any Python 2.7
maintenance release.

* Menu:

* Two new environment variables for debug mode::
* PEP 434; IDLE Enhancement Exception for All Branches: PEP 434 IDLE Enhancement Exception for All Branches.
* PEP 466; Network Security Enhancements for Python 2.7: PEP 466 Network Security Enhancements for Python 2 7.
* PEP 477; Backport ensurepip (PEP 453) to Python 2.7: PEP 477 Backport ensurepip PEP 453 to Python 2 7.
* PEP 476; Enabling certificate verification by default for stdlib http clients: PEP 476 Enabling certificate verification by default for stdlib http clients<2>.
* PEP 493; HTTPS verification migration tools for Python 2.7: PEP 493 HTTPS verification migration tools for Python 2 7.
* New make regen-all build target: New make regen-all build target<3>.
* Removal of make touch build target: Removal of make touch build target<3>.


File: python.info,  Node: Two new environment variables for debug mode,  Next: PEP 434 IDLE Enhancement Exception for All Branches,  Up: New Features Added to Python 2 7 Maintenance Releases

1.16.15.1 Two new environment variables for debug mode
......................................................

In debug mode, the ‘[xxx refs]’ statistic is not written by default, the
‘PYTHONSHOWREFCOUNT’ environment variable now must also be set.
(Contributed by Victor Stinner; bpo-31733(1).)

When Python is compiled with ‘COUNT_ALLOC’ defined, allocation counts
are no longer dumped by default anymore: the ‘PYTHONSHOWALLOCCOUNT’
environment variable must now also be set.  Moreover, allocation counts
are now dumped into stderr, rather than stdout.  (Contributed by Victor
Stinner; bpo-31692(2).)

Added in version 2.7.15.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31733

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31692


File: python.info,  Node: PEP 434 IDLE Enhancement Exception for All Branches,  Next: PEP 466 Network Security Enhancements for Python 2 7,  Prev: Two new environment variables for debug mode,  Up: New Features Added to Python 2 7 Maintenance Releases

1.16.15.2 PEP 434: IDLE Enhancement Exception for All Branches
..............................................................

PEP 434(1) describes a general exemption for changes made to the IDLE
development environment shipped along with Python.  This exemption makes
it possible for the IDLE developers to provide a more consistent user
experience across all supported versions of Python 2 and 3.

For details of any IDLE changes, refer to the NEWS file for the specific
release.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0434/


File: python.info,  Node: PEP 466 Network Security Enhancements for Python 2 7,  Next: PEP 477 Backport ensurepip PEP 453 to Python 2 7,  Prev: PEP 434 IDLE Enhancement Exception for All Branches,  Up: New Features Added to Python 2 7 Maintenance Releases

1.16.15.3 PEP 466: Network Security Enhancements for Python 2.7
...............................................................

PEP 466(1) describes a number of network security enhancement proposals
that have been approved for inclusion in Python 2.7 maintenance
releases, with the first of those changes appearing in the Python 2.7.7
release.

PEP 466(2) related features added in Python 2.7.7:

   * *note hmac.compare_digest(): 12d1. was backported from Python 3 to
     make a timing attack resistant comparison operation available to
     Python 2 applications.  (Contributed by Alex Gaynor; bpo-21306(3).)

   * OpenSSL 1.0.1g was upgraded in the official Windows installers
     published on python.org.  (Contributed by Zachary Ware;
     bpo-21462(4).)

PEP 466(5) related features added in Python 2.7.8:

   * *note hashlib.pbkdf2_hmac(): 734. was backported from Python 3 to
     make a hashing algorithm suitable for secure password storage
     broadly available to Python 2 applications.  (Contributed by Alex
     Gaynor; bpo-21304(6).)

   * OpenSSL 1.0.1h was upgraded for the official Windows installers
     published on python.org.  (Contributed by Zachary Ware in
     bpo-21671(7) for CVE 2014-0224(8).)

PEP 466(9) related features added in Python 2.7.9:

   * Most of Python 3.4’s *note ssl: d5. module was backported.  This
     means *note ssl: d5. now supports Server Name Indication, TLS1.x
     settings, access to the platform certificate store, the *note
     SSLContext: 357. class, and other features.  (Contributed by Alex
     Gaynor and David Reid; bpo-21308(10).)

     Refer to the «Version added: 2.7.9» notes in the module
     documentation for specific details.

   * *note os.urandom(): 747. was changed to cache a file descriptor to
     ‘/dev/urandom’ instead of reopening ‘/dev/urandom’ on every call.
     (Contributed by Alex Gaynor; bpo-21305(11).)

   * *note hashlib.algorithms_guaranteed: 157b. and *note
     hashlib.algorithms_available: 157c. were backported from Python 3
     to make it easier for Python 2 applications to select the strongest
     available hash algorithm.  (Contributed by Alex Gaynor in
     bpo-21307(12))

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0466/

   (2) https://peps.python.org/pep-0466/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21306

   (4) https://bugs.python.org/issue?@action=redirect&bpo=21462

   (5) https://peps.python.org/pep-0466/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=21304

   (7) https://bugs.python.org/issue?@action=redirect&bpo=21671

   (8) https://www.cve.org/CVERecord?id=CVE-2014-0224

   (9) https://peps.python.org/pep-0466/

   (10) https://bugs.python.org/issue?@action=redirect&bpo=21308

   (11) https://bugs.python.org/issue?@action=redirect&bpo=21305

   (12) https://bugs.python.org/issue?@action=redirect&bpo=21307


File: python.info,  Node: PEP 477 Backport ensurepip PEP 453 to Python 2 7,  Next: PEP 476 Enabling certificate verification by default for stdlib http clients<2>,  Prev: PEP 466 Network Security Enhancements for Python 2 7,  Up: New Features Added to Python 2 7 Maintenance Releases

1.16.15.4 PEP 477: Backport ensurepip (PEP 453) to Python 2.7
.............................................................

PEP 477(1) approves the inclusion of the PEP 453(2) ensurepip module and
the improved documentation that was enabled by it in the Python 2.7
maintenance releases, appearing first in the Python 2.7.9 release.

* Menu:

* Bootstrapping pip By Default: Bootstrapping pip By Default<2>.
* Documentation Changes: Documentation Changes<2>.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0477/

   (2) https://peps.python.org/pep-0453/


File: python.info,  Node: Bootstrapping pip By Default<2>,  Next: Documentation Changes<2>,  Up: PEP 477 Backport ensurepip PEP 453 to Python 2 7

1.16.15.5 Bootstrapping pip By Default
......................................

The new *note ensurepip: 59. module (defined in PEP 453(1)) provides a
standard cross-platform mechanism to bootstrap the pip installer into
Python installations.  The version of ‘pip’ included with Python 2.7.9
is ‘pip’ 1.5.6, and future 2.7.x maintenance releases will update the
bundled version to the latest version of ‘pip’ that is available at the
time of creating the release candidate.

By default, the commands ‘pip’, ‘pipX’ and ‘pipX.Y’ will be installed on
all platforms (where X.Y stands for the version of the Python
installation), along with the ‘pip’ Python package and its dependencies.

For CPython *note source builds on POSIX systems: 10f8, the ‘make
install’ and ‘make altinstall’ commands do not bootstrap ‘pip’ by
default.  This behaviour can be controlled through configure options,
and overridden through Makefile options.

On Windows and Mac OS X, the CPython installers now default to
installing ‘pip’ along with CPython itself (users may opt out of
installing it during the installation process).  Window users will need
to opt in to the automatic ‘PATH’ modifications to have ‘pip’ available
from the command line by default, otherwise it can still be accessed
through the Python launcher for Windows as ‘py -m pip’.

As discussed in the PEP(2), platform packagers may choose not to install
these commands by default, as long as, when invoked, they provide clear
and simple directions on how to install them on that platform (usually
using the system package manager).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0453/

   (2) 
https://peps.python.org/pep-0477/#disabling-ensurepip-by-downstream-distributors


File: python.info,  Node: Documentation Changes<2>,  Prev: Bootstrapping pip By Default<2>,  Up: PEP 477 Backport ensurepip PEP 453 to Python 2 7

1.16.15.6 Documentation Changes
...............................

As part of this change, the *note Installing Python Modules: 10fa. and
distributing-index sections of the documentation have been completely
redesigned as short getting started and FAQ documents.  Most packaging
documentation has now been moved out to the Python Packaging Authority
maintained Python Packaging User Guide(1) and the documentation of the
individual projects.

However, as this migration is currently still incomplete, the legacy
versions of those guides remaining available as *note Building C and C++
Extensions with setuptools: 10fb. and *note Building C and C++
Extensions with setuptools: 10fc.

Vedi anche
..........

PEP 453(2) – Explicit bootstrapping of pip in Python installations

     PEP written by Donald Stufft and Nick Coghlan, implemented by
     Donald Stufft, Nick Coghlan, Martin von Löwis and Ned Deily.

   ---------- Footnotes ----------

   (1) https://packaging.python.org

   (2) https://peps.python.org/pep-0453/


File: python.info,  Node: PEP 476 Enabling certificate verification by default for stdlib http clients<2>,  Next: PEP 493 HTTPS verification migration tools for Python 2 7,  Prev: PEP 477 Backport ensurepip PEP 453 to Python 2 7,  Up: New Features Added to Python 2 7 Maintenance Releases

1.16.15.7 PEP 476: Enabling certificate verification by default for stdlib http clients
.......................................................................................

PEP 476(1) updated *note httplib: 72. and modules which use it, such as
*note urllib2: 111. and *note xmlrpclib: 134, to now verify that the
server presents a certificate which is signed by a Certificate Authority
in the platform trust store and whose hostname matches the hostname
being requested by default, significantly improving security for many
applications.  This change was made in the Python 2.7.9 release.

For applications which require the old previous behavior, they can pass
an alternate context:

     import urllib2
     import ssl

     # This disables all verification
     context = ssl._create_unverified_context()

     # This allows using a specific certificate for the host, which doesn't need
     # to be in the trust store
     context = ssl.create_default_context(cafile="/path/to/file.crt")

     urllib2.urlopen("https://invalid-cert", context=context)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0476/


File: python.info,  Node: PEP 493 HTTPS verification migration tools for Python 2 7,  Next: New make regen-all build target<3>,  Prev: PEP 476 Enabling certificate verification by default for stdlib http clients<2>,  Up: New Features Added to Python 2 7 Maintenance Releases

1.16.15.8 PEP 493: HTTPS verification migration tools for Python 2.7
....................................................................

PEP 493(1) provides additional migration tools to support a more
incremental infrastructure upgrade process for environments containing
applications and services relying on the historically permissive
processing of server certificates when establishing client HTTPS
connections.  These additions were made in the Python 2.7.12 release.

These tools are intended for use in cases where affected applications
and services can’t be modified to explicitly pass a more permissive SSL
context when establishing the connection.

For applications and services which can’t be modified at all, the new
‘PYTHONHTTPSVERIFY’ environment variable may be set to ‘0’ to revert an
entire Python process back to the default permissive behaviour of Python
2.7.8 and earlier.

For cases where the connection establishment code can’t be modified, but
the overall application can be, the new
‘ssl._https_verify_certificates()’ function can be used to adjust the
default behaviour at runtime.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0493/


File: python.info,  Node: New make regen-all build target<3>,  Next: Removal of make touch build target<3>,  Prev: PEP 493 HTTPS verification migration tools for Python 2 7,  Up: New Features Added to Python 2 7 Maintenance Releases

1.16.15.9 New ‘make regen-all’ build target
...........................................

To simplify cross-compilation, and to ensure that CPython can reliably
be compiled without requiring an existing version of Python to already
be available, the autotools-based build system no longer attempts to
implicitly recompile generated files based on file modification times.

Instead, a new ‘make regen-all’ command has been added to force
regeneration of these files when desired (e.g.  after an initial version
of Python has already been built based on the pregenerated versions).

More selective regeneration targets are also defined - see
Makefile.pre.in(1) for details.

(Contributed by Victor Stinner in bpo-23404(2).)

Added in version 2.7.14.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Makefile.pre.in

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23404


File: python.info,  Node: Removal of make touch build target<3>,  Prev: New make regen-all build target<3>,  Up: New Features Added to Python 2 7 Maintenance Releases

1.16.15.10 Removal of ‘make touch’ build target
...............................................

The ‘make touch’ build target previously used to request implicit
regeneration of generated files by updating their modification times has
been removed.

It has been replaced by the new ‘make regen-all’ target.

(Contributed by Victor Stinner in bpo-23404(1).)

Cambiato nella versione 2.7.14.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23404


File: python.info,  Node: Acknowledgements,  Prev: New Features Added to Python 2 7 Maintenance Releases,  Up: What’s New in Python 2 7

1.16.16 Acknowledgements
------------------------

The author would like to thank the following people for offering
suggestions, corrections and assistance with various drafts of this
article: Nick Coghlan, Philip Jenvey, Ryan Lovett, R. David Murray, Hugh
Secker-Walker.


File: python.info,  Node: What’s New in Python 2 6,  Next: What’s New in Python 2 5,  Prev: What’s New in Python 2 7,  Up: Novità in Python

1.17 What’s New in Python 2.6
=============================


Author: A.M. Kuchling (amk at amk.ca)

This article explains the new features in Python 2.6, released on
October 1, 2008.  The release schedule is described in PEP 361(1).

The major theme of Python 2.6 is preparing the migration path to Python
3.0, a major redesign of the language.  Whenever possible, Python 2.6
incorporates new features and syntax from 3.0 while remaining compatible
with existing code by not removing older features or syntax.  When it’s
not possible to do that, Python 2.6 tries to do what it can, adding
compatibility functions in a ‘future_builtins’ module and a ‘-3’ switch
to warn about usages that will become unsupported in 3.0.

Some significant new packages have been added to the standard library,
such as the *note multiprocessing: 98. and *note json: 86. modules, but
there aren’t many new features that aren’t related to Python 3.0 in some
way.

Python 2.6 also sees a number of improvements and bugfixes throughout
the source.  A search through the change logs finds there were 259
patches applied and 612 bugs fixed between Python 2.5 and 2.6.  Both
figures are likely to be underestimates.

This article doesn’t attempt to provide a complete specification of the
new features, but instead provides a convenient overview.  For full
details, you should refer to the documentation for Python 2.6.  If you
want to understand the rationale for the design and implementation,
refer to the PEP for a particular new feature.  Whenever possible,
«What’s New in Python» links to the bug/patch item for each change.

* Menu:

* Python 3.0: Python 3 0.
* Changes to the Development Process::
* PEP 343; The “with” statement: PEP 343 The “with” statement.
* PEP 366; Explicit Relative Imports From a Main Module: PEP 366 Explicit Relative Imports From a Main Module.
* PEP 370; Per-user site-packages Directory: PEP 370 Per-user site-packages Directory.
* PEP 371; The multiprocessing Package: PEP 371 The multiprocessing Package.
* PEP 3101; Advanced String Formatting: PEP 3101 Advanced String Formatting.
* PEP 3105; print As a Function: PEP 3105 print As a Function.
* PEP 3110; Exception-Handling Changes: PEP 3110 Exception-Handling Changes.
* PEP 3112; Byte Literals: PEP 3112 Byte Literals.
* PEP 3116; New I/O Library: PEP 3116 New I/O Library.
* PEP 3118; Revised Buffer Protocol: PEP 3118 Revised Buffer Protocol.
* PEP 3119; Abstract Base Classes: PEP 3119 Abstract Base Classes.
* PEP 3127; Integer Literal Support and Syntax: PEP 3127 Integer Literal Support and Syntax.
* PEP 3129; Class Decorators: PEP 3129 Class Decorators.
* PEP 3141; A Type Hierarchy for Numbers: PEP 3141 A Type Hierarchy for Numbers.
* Other Language Changes: Other Language Changes<14>.
* New and Improved Modules: New and Improved Modules<2>.
* Deprecations and Removals::
* Build and C API Changes: Build and C API Changes<9>.
* Porting to Python 2.6: Porting to Python 2 6.
* Acknowledgements: Acknowledgements<2>.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0361/


File: python.info,  Node: Python 3 0,  Next: Changes to the Development Process,  Up: What’s New in Python 2 6

1.17.1 Python 3.0
-----------------

The development cycle for Python versions 2.6 and 3.0 was synchronized,
with the alpha and beta releases for both versions being made on the
same days.  The development of 3.0 has influenced many features in 2.6.

Python 3.0 is a far-ranging redesign of Python that breaks compatibility
with the 2.x series.  This means that existing Python code will need
some conversion in order to run on Python 3.0.  However, not all the
changes in 3.0 necessarily break compatibility.  In cases where new
features won’t cause existing code to break, they’ve been backported to
2.6 and are described in this document in the appropriate place.  Some
of the 3.0-derived features are:

   * A ‘__complex__()’ method for converting objects to a complex
     number.

   * Alternate syntax for catching exceptions: ‘except TypeError as
     exc’.

   * The addition of *note functools.reduce(): 21a. as a synonym for the
     built-in ‘reduce()’ function.

Python 3.0 adds several new built-in functions and changes the semantics
of some existing builtins.  Functions that are new in 3.0 such as *note
bin(): 14b0. have simply been added to Python 2.6, but existing builtins
haven’t been changed; instead, the ‘future_builtins’ module has versions
with the new 3.0 semantics.  Code written to be compatible with 3.0 can
do ‘from future_builtins import hex, map’ as necessary.

A new command-line switch, ‘-3’, enables warnings about features that
will be removed in Python 3.0.  You can run code with this switch to see
how much work will be necessary to port code to 3.0.  The value of this
switch is available to Python code as the boolean variable
‘sys.py3kwarning’, and to C extension code as ‘Py_Py3kWarningFlag’.

Vedi anche
..........

The 3'xxx' series of PEPs, which contains proposals for Python 3.0.  PEP
3000(1) describes the development process for Python 3.0.  Start with
PEP 3100(2) that describes the general goals for Python 3.0, and then
explore the higher-numbered PEPs that propose specific features.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3000/

   (2) https://peps.python.org/pep-3100/


File: python.info,  Node: Changes to the Development Process,  Next: PEP 343 The “with” statement,  Prev: Python 3 0,  Up: What’s New in Python 2 6

1.17.2 Changes to the Development Process
-----------------------------------------

While 2.6 was being developed, the Python development process underwent
two significant changes: we switched from SourceForge’s issue tracker to
a customized Roundup installation, and the documentation was converted
from LaTeX to reStructuredText.

* Menu:

* New Issue Tracker; Roundup: New Issue Tracker Roundup.
* New Documentation Format; reStructuredText Using Sphinx: New Documentation Format reStructuredText Using Sphinx.


File: python.info,  Node: New Issue Tracker Roundup,  Next: New Documentation Format reStructuredText Using Sphinx,  Up: Changes to the Development Process

1.17.2.1 New Issue Tracker: Roundup
...................................

For a long time, the Python developers had been growing increasingly
annoyed by SourceForge’s bug tracker.  SourceForge’s hosted solution
doesn’t permit much customization; for example, it wasn’t possible to
customize the life cycle of issues.

The infrastructure committee of the Python Software Foundation therefore
posted a call for issue trackers, asking volunteers to set up different
products and import some of the bugs and patches from SourceForge.  Four
different trackers were examined: Jira(1), Launchpad(2), Roundup(3), and
Trac(4).  The committee eventually settled on Jira and Roundup as the
two candidates.  Jira is a commercial product that offers no-cost hosted
instances to free-software projects; Roundup is an open-source project
that requires volunteers to administer it and a server to host it.

After posting a call for volunteers, a new Roundup installation was set
up at ‘https://bugs.python.org’.  One installation of Roundup can host
multiple trackers, and this server now also hosts issue trackers for
Jython and for the Python web site.  It will surely find other uses in
the future.  Where possible, this edition of «What’s New in Python»
links to the bug/patch item for each change.

Hosting of the Python bug tracker is kindly provided by Upfront
Systems(5) of Stellenbosch, South Africa.  Martin von Löwis put a lot of
effort into importing existing bugs and patches from SourceForge; his
scripts for this import operation are at
‘https://svn.python.org/view/tracker/importer/’ and may be useful to
other projects wishing to move from SourceForge to Roundup.

Vedi anche
..........

‘https://bugs.python.org’

     The Python bug tracker.

‘https://bugs.jython.org’:

     The Jython bug tracker.

‘https://roundup.sourceforge.io/’

     Roundup downloads and documentation.

‘https://svn.python.org/view/tracker/importer/’

     Martin von Löwis’s conversion scripts.

   ---------- Footnotes ----------

   (1) https://www.atlassian.com/software/jira/

   (2) https://launchpad.net/

   (3) https://roundup.sourceforge.io/

   (4) https://trac.edgewall.org/

   (5) https://upfrontsoftware.co.za


File: python.info,  Node: New Documentation Format reStructuredText Using Sphinx,  Prev: New Issue Tracker Roundup,  Up: Changes to the Development Process

1.17.2.2 New Documentation Format: reStructuredText Using Sphinx
................................................................

The Python documentation was written using LaTeX since the project
started around 1989.  In the 1980s and early 1990s, most documentation
was printed out for later study, not viewed online.  LaTeX was widely
used because it provided attractive printed output while remaining
straightforward to write once the basic rules of the markup were
learned.

Today LaTeX is still used for writing publications destined for
printing, but the landscape for programming tools has shifted.  We no
longer print out reams of documentation; instead, we browse through it
online and HTML has become the most important format to support.
Unfortunately, converting LaTeX to HTML is fairly complicated and Fred
L.  Drake Jr., the long-time Python documentation editor, spent a lot of
time maintaining the conversion process.  Occasionally people would
suggest converting the documentation into SGML and later XML, but
performing a good conversion is a major task and no one ever committed
the time required to finish the job.

During the 2.6 development cycle, Georg Brandl put a lot of effort into
building a new toolchain for processing the documentation.  The
resulting package is called Sphinx, and is available from
‘https://www.sphinx-doc.org/’.

Sphinx concentrates on HTML output, producing attractively styled and
modern HTML; printed output is still supported through conversion to
LaTeX. The input format is reStructuredText, a markup syntax supporting
custom extensions and directives that is commonly used in the Python
community.

Sphinx is a standalone package that can be used for writing, and almost
two dozen other projects (listed on the Sphinx web site(1)) have adopted
Sphinx as their documentation tool.

Vedi anche
..........

Documenting Python(2)

     Describes how to write for Python’s documentation.

Sphinx(3)

     Documentation and code for the Sphinx toolchain.

Docutils(4)

     The underlying reStructuredText parser and toolset.

   ---------- Footnotes ----------

   (1) https://www.sphinx-doc.org/en/master/examples.html

   (2) https://devguide.python.org/documenting/

   (3) https://www.sphinx-doc.org/

   (4) https://docutils.sourceforge.io


File: python.info,  Node: PEP 343 The “with” statement,  Next: PEP 366 Explicit Relative Imports From a Main Module,  Prev: Changes to the Development Process,  Up: What’s New in Python 2 6

1.17.3 PEP 343: The “with” statement
------------------------------------

The previous version, Python 2.5, added the “*note with: 186.” statement
as an optional feature, to be enabled by a ‘from __future__ import
with_statement’ directive.  In 2.6 the statement no longer needs to be
specially enabled; this means that ‘with’ is now always a keyword.  The
rest of this section is a copy of the corresponding section from the
«What’s New in Python 2.5» document; if you’re familiar with the
“‘with’” statement from Python 2.5, you can skip this section.

The “*note with: 186.” statement clarifies code that previously would
use ‘try...finally’ blocks to ensure that clean-up code is executed.  In
this section, I’ll discuss the statement as it will commonly be used.
In the next section, I’ll examine the implementation details and show
how to write objects for use with this statement.

The “*note with: 186.” statement is a control-flow structure whose basic
structure is:

     with expression [as variable]:
         with-block

The expression is evaluated, and it should result in an object that
supports the context management protocol (that is, has *note
__enter__(): 7e5. and *note __exit__(): 1508. methods).

The object’s *note __enter__(): 7e5. is called before 'with-block' is
executed and therefore can run set-up code.  It also may return a value
that is bound to the name 'variable', if given.  (Note carefully that
'variable' is 'not' assigned the result of 'expression'.)

After execution of the 'with-block' is finished, the object’s *note
__exit__(): 1508. method is called, even if the block raised an
exception, and can therefore run clean-up code.

Some standard Python objects now support the context management protocol
and can be used with the “*note with: 186.” statement.  File objects are
one example:

     with open('/etc/passwd', 'r') as f:
         for line in f:
             print line
             ... more processing code ...

After this statement has executed, the file object in 'f' will have been
automatically closed, even if the *note for: 34a. loop raised an
exception part-way through the block.

     Nota: In this case, 'f' is the same object created by *note open():
     316, because *note __enter__(): 7e5. returns 'self'.

The *note threading: f3. module’s locks and condition variables also
support the “*note with: 186.” statement:

     lock = threading.Lock()
     with lock:
         # Critical section of code
         ...

The lock is acquired before the block is executed and always released
once the block is complete.

The *note localcontext(): 158e. function in the *note decimal: 3a.
module makes it easy to save and restore the current decimal context,
which encapsulates the desired precision and rounding characteristics
for computations:

     from decimal import Decimal, Context, localcontext

     # Displays with default precision of 28 digits
     v = Decimal('578')
     print v.sqrt()

     with localcontext(Context(prec=16)):
         # All code in this block uses a precision of 16 digits.
         # The original context is restored on exiting the block.
         print v.sqrt()

* Menu:

* Writing Context Managers::
* The contextlib module::


File: python.info,  Node: Writing Context Managers,  Next: The contextlib module,  Up: PEP 343 The “with” statement

1.17.3.1 Writing Context Managers
.................................

Under the hood, the “*note with: 186.” statement is fairly complicated.
Most people will only use “‘with’” in company with existing objects and
don’t need to know these details, so you can skip the rest of this
section if you like.  Authors of new objects will need to understand the
details of the underlying implementation and should keep reading.

A high-level explanation of the context management protocol is:

   * The expression is evaluated and should result in an object called a
     «context manager».  The context manager must have *note
     __enter__(): 7e5. and *note __exit__(): 1508. methods.

   * The context manager’s *note __enter__(): 7e5. method is called.
     The value returned is assigned to 'VAR'. If no ‘as VAR’ clause is
     present, the value is simply discarded.

   * The code in 'BLOCK' is executed.

   * If 'BLOCK' raises an exception, the context manager’s *note
     __exit__(): 1508. method is called with three arguments, the
     exception details (‘type, value, traceback’, the same values
     returned by *note sys.exc_info(): 89b, which can also be ‘None’ if
     no exception occurred).  The method’s return value controls whether
     an exception is re-raised: any false value re-raises the exception,
     and ‘True’ will result in suppressing it.  You’ll only rarely want
     to suppress the exception, because if you do the author of the code
     containing the “*note with: 186.” statement will never realize
     anything went wrong.

   * If 'BLOCK' didn’t raise an exception, the *note __exit__(): 1508.
     method is still called, but 'type', 'value', and 'traceback' are
     all ‘None’.

Let’s think through an example.  I won’t present detailed code but will
only sketch the methods necessary for a database that supports
transactions.

(For people unfamiliar with database terminology: a set of changes to
the database are grouped into a transaction.  Transactions can be either
committed, meaning that all the changes are written into the database,
or rolled back, meaning that the changes are all discarded and the
database is unchanged.  See any database textbook for more information.)

Let’s assume there’s an object representing a database connection.  Our
goal will be to let the user write code like this:

     db_connection = DatabaseConnection()
     with db_connection as cursor:
         cursor.execute('insert into ...')
         cursor.execute('delete from ...')
         # ... more operations ...

The transaction should be committed if the code in the block runs
flawlessly or rolled back if there’s an exception.  Here’s the basic
interface for ‘DatabaseConnection’ that I’ll assume:

     class DatabaseConnection:
         # Database interface
         def cursor(self):
             "Returns a cursor object and starts a new transaction"
         def commit(self):
             "Commits current transaction"
         def rollback(self):
             "Rolls back current transaction"

The *note __enter__(): 7e5. method is pretty easy, having only to start
a new transaction.  For this application the resulting cursor object
would be a useful result, so the method will return it.  The user can
then add ‘as cursor’ to their “*note with: 186.” statement to bind the
cursor to a variable name.

     class DatabaseConnection:
         ...
         def __enter__(self):
             # Code to start a new transaction
             cursor = self.cursor()
             return cursor

The *note __exit__(): 1508. method is the most complicated because it’s
where most of the work has to be done.  The method has to check if an
exception occurred.  If there was no exception, the transaction is
committed.  The transaction is rolled back if there was an exception.

In the code below, execution will just fall off the end of the function,
returning the default value of ‘None’.  ‘None’ is false, so the
exception will be re-raised automatically.  If you wished, you could be
more explicit and add a *note return: 1af. statement at the marked
location.

     class DatabaseConnection:
         ...
         def __exit__(self, type, value, tb):
             if tb is None:
                 # No exception, so commit
                 self.commit()
             else:
                 # Exception occurred, so rollback.
                 self.rollback()
                 # return False


File: python.info,  Node: The contextlib module,  Prev: Writing Context Managers,  Up: PEP 343 The “with” statement

1.17.3.2 The contextlib module
..............................

The *note contextlib: 27. module provides some functions and a decorator
that are useful when writing objects for use with the “*note with: 186.”
statement.

The decorator is called *note contextmanager(): 140a, and lets you write
a single generator function instead of defining a new class.  The
generator should yield exactly one value.  The code up to the *note
yield: bc4. will be executed as the *note __enter__(): 7e5. method, and
the value yielded will be the method’s return value that will get bound
to the variable in the “*note with: 186.” statement’s ‘as’ clause, if
any.  The code after the ‘yield’ will be executed in the *note
__exit__(): 1508. method.  Any exception raised in the block will be
raised by the ‘yield’ statement.

Using this decorator, our database example from the previous section
could be written as:

     from contextlib import contextmanager

     @contextmanager
     def db_transaction(connection):
         cursor = connection.cursor()
         try:
             yield cursor
         except:
             connection.rollback()
             raise
         else:
             connection.commit()

     db = DatabaseConnection()
     with db_transaction(db) as cursor:
         ...

The *note contextlib: 27. module also has a ‘nested(mgr1, mgr2, ...)’
function that combines a number of context managers so you don’t need to
write nested “*note with: 186.” statements.  In this example, the single
“‘with’” statement both starts a database transaction and acquires a
thread lock:

     lock = threading.Lock()
     with nested (db_transaction(db), lock) as (cursor, locked):
         ...

Finally, the *note closing(): 1591. function returns its argument so
that it can be bound to a variable, and calls the argument’s ‘.close()’
method at the end of the block.

     import urllib, sys
     from contextlib import closing

     with closing(urllib.urlopen('http://www.yahoo.com')) as f:
         for line in f:
             sys.stdout.write(line)

Vedi anche
..........

PEP 343(1) - The «with» statement

     PEP written by Guido van Rossum and Nick Coghlan; implemented by
     Mike Bland, Guido van Rossum, and Neal Norwitz.  The PEP shows the
     code generated for a “*note with: 186.” statement, which can be
     helpful in learning how the statement works.

The documentation for the *note contextlib: 27. module.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0343/


File: python.info,  Node: PEP 366 Explicit Relative Imports From a Main Module,  Next: PEP 370 Per-user site-packages Directory,  Prev: PEP 343 The “with” statement,  Up: What’s New in Python 2 6

1.17.4 PEP 366: Explicit Relative Imports From a Main Module
------------------------------------------------------------

Python’s *note -m: 23c. switch allows running a module as a script.
When you ran a module that was located inside a package, relative
imports didn’t work correctly.

The fix for Python 2.6 adds a *note module.__package__: 323. attribute.
When this attribute is present, relative imports will be relative to the
value of this attribute instead of the *note __name__: 1593. attribute.

PEP 302-style importers can then set *note __package__: 323. as
necessary.  The *note runpy: c3. module that implements the *note -m:
23c. switch now does this, so relative imports will now work correctly
in scripts running from inside a package.


File: python.info,  Node: PEP 370 Per-user site-packages Directory,  Next: PEP 371 The multiprocessing Package,  Prev: PEP 366 Explicit Relative Imports From a Main Module,  Up: What’s New in Python 2 6

1.17.5 PEP 370: Per-user ‘site-packages’ Directory
--------------------------------------------------

When you run Python, the module search path ‘sys.path’ usually includes
a directory whose path ends in ‘"site-packages"’.  This directory is
intended to hold locally installed packages available to all users using
a machine or a particular site installation.

Python 2.6 introduces a convention for user-specific site directories.
The directory varies depending on the platform:

   * Unix and Mac OS X: ‘~/.local/’

   * Windows: ‘%APPDATA%/Python’

Within this directory, there will be version-specific subdirectories,
such as ‘lib/python2.6/site-packages’ on Unix/Mac OS and
‘Python26/site-packages’ on Windows.

If you don’t like the default directory, it can be overridden by an
environment variable.  *note PYTHONUSERBASE: 1595. sets the root
directory used for all Python versions supporting this feature.  On
Windows, the directory for application-specific data can be changed by
setting the ‘APPDATA’ environment variable.  You can also modify the
‘site.py’ file for your Python installation.

The feature can be disabled entirely by running Python with the *note
-s: 1596. option or setting the *note PYTHONNOUSERSITE: 1597.
environment variable.

Vedi anche
..........

PEP 370(1) - Per-user ‘site-packages’ Directory

     PEP written and implemented by Christian Heimes.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0370/


File: python.info,  Node: PEP 371 The multiprocessing Package,  Next: PEP 3101 Advanced String Formatting,  Prev: PEP 370 Per-user site-packages Directory,  Up: What’s New in Python 2 6

1.17.6 PEP 371: The ‘multiprocessing’ Package
---------------------------------------------

The new *note multiprocessing: 98. package lets Python programs create
new processes that will perform a computation and return a result to the
parent.  The parent and child processes can communicate using queues and
pipes, synchronize their operations using locks and semaphores, and can
share simple arrays of data.

The *note multiprocessing: 98. module started out as an exact emulation
of the *note threading: f3. module using processes instead of threads.
That goal was discarded along the path to Python 2.6, but the general
approach of the module is still similar.  The fundamental class is the
*note Process: 252, which is passed a callable object and a collection
of arguments.  The *note start(): 1599. method sets the callable running
in a subprocess, after which you can call the *note is_alive(): 159a.
method to check whether the subprocess is still running and the *note
join(): 159b. method to wait for the process to exit.

Here’s a simple example where the subprocess will calculate a factorial.
The function doing the calculation is written strangely so that it takes
significantly longer when the input argument is a multiple of 4.

     import time
     from multiprocessing import Process, Queue


     def factorial(queue, N):
         "Compute a factorial."
         # If N is a multiple of 4, this function will take much longer.
         if (N % 4) == 0:
             time.sleep(.05 * N/4)

         # Calculate the result
         fact = 1L
         for i in range(1, N+1):
             fact = fact * i

         # Put the result on the queue
         queue.put(fact)

     if __name__ == '__main__':
         queue = Queue()

         N = 5

         p = Process(target=factorial, args=(queue, N))
         p.start()
         p.join()

         result = queue.get()
         print 'Factorial', N, '=', result

A *note Queue: 159c. is used to communicate the result of the factorial.
The *note Queue: 159c. object is stored in a global variable.  The child
process will use the value of the variable when the child was created;
because it’s a *note Queue: 159c, parent and child can use the object to
communicate.  (If the parent were to change the value of the global
variable, the child’s value would be unaffected, and vice versa.)

Two other classes, *note Pool: 116d. and *note Manager: 250, provide
higher-level interfaces.  *note Pool: 116d. will create a fixed number
of worker processes, and requests can then be distributed to the workers
by calling *note apply(): 159d. or *note apply_async(): 159e. to add a
single request, and *note map(): 12ed. or *note map_async(): 12ee. to
add a number of requests.  The following code uses a *note Pool: 116d.
to spread requests across 5 worker processes and retrieve a list of
results:

     from multiprocessing import Pool

     def factorial(N, dictionary):
         "Compute a factorial."
         ...
     p = Pool(5)
     result = p.map(factorial, range(1, 1000, 10))
     for v in result:
         print v

This produces the following output:

     1
     39916800
     51090942171709440000
     8222838654177922817725562880000000
     33452526613163807108170062053440751665152000000000
     ...

The other high-level interface, the *note Manager: 250. class, creates a
separate server process that can hold master copies of Python data
structures.  Other processes can then access and modify these data
structures using proxy objects.  The following example creates a shared
dictionary by calling the *note dict(): 183. method; the worker
processes then insert values into the dictionary.  (Locking is not done
for you automatically, which doesn’t matter in this example.  *note
Manager: 250.’s methods also include *note Lock(): 159f, *note RLock():
15a0, and *note Semaphore(): 15a1. to create shared locks.)

     import time
     from multiprocessing import Pool, Manager

     def factorial(N, dictionary):
         "Compute a factorial."
         # Calculate the result
         fact = 1L
         for i in range(1, N+1):
             fact = fact * i

         # Store result in dictionary
         dictionary[N] = fact

     if __name__ == '__main__':
         p = Pool(5)
         mgr = Manager()
         d = mgr.dict()         # Create shared dictionary

         # Run tasks using the pool
         for N in range(1, 1000, 10):
             p.apply_async(factorial, (N, d))

         # Mark pool as closed -- no more tasks can be added.
         p.close()

         # Wait for tasks to exit
         p.join()

         # Output results
         for k, v in sorted(d.items()):
             print k, v

This will produce the output:

     1 1
     11 39916800
     21 51090942171709440000
     31 8222838654177922817725562880000000
     41 33452526613163807108170062053440751665152000000000
     51 15511187532873822802242430164693032110632597200169861120000...

Vedi anche
..........

The documentation for the *note multiprocessing: 98. module.

PEP 371(1) - Addition of the multiprocessing package

     PEP written by Jesse Noller and Richard Oudkerk; implemented by
     Richard Oudkerk and Jesse Noller.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0371/


File: python.info,  Node: PEP 3101 Advanced String Formatting,  Next: PEP 3105 print As a Function,  Prev: PEP 371 The multiprocessing Package,  Up: What’s New in Python 2 6

1.17.7 PEP 3101: Advanced String Formatting
-------------------------------------------

In Python 3.0, the ‘%’ operator is supplemented by a more powerful
string formatting method, *note format(): 199.  Support for the *note
str.format(): 834. method has been backported to Python 2.6.

In 2.6, both 8-bit and Unicode strings have a ‘.format()’ method that
treats the string as a template and takes the arguments to be formatted.
The formatting template uses curly brackets (‘{’, ‘}’) as special
characters:

     >>> # Substitute positional argument 0 into the string.
     >>> "User ID: {0}".format("root")
     'User ID: root'
     >>> # Use the named keyword arguments
     >>> "User ID: {uid}   Last seen: {last_login}".format(
     ...    uid="root",
     ...    last_login = "5 Mar 2008 07:20")
     'User ID: root   Last seen: 5 Mar 2008 07:20'

Curly brackets can be escaped by doubling them:

     >>> "Empty dict: {{}}".format()
     "Empty dict: {}"

Field names can be integers indicating positional arguments, such as
‘{0}’, ‘{1}’, etc.  or names of keyword arguments.  You can also supply
compound field names that read attributes or access dictionary keys:

     >>> import sys
     >>> print 'Platform: {0.platform}\nPython version: {0.version}'.format(sys)
     Platform: darwin
     Python version: 2.6a1+ (trunk:61261M, Mar  5 2008, 20:29:41)
     [GCC 4.0.1 (Apple Computer, Inc. build 5367)]'

     >>> import mimetypes
     >>> 'Content-type: {0[.mp4]}'.format(mimetypes.types_map)
     'Content-type: video/mp4'

Note that when using dictionary-style notation such as ‘[.mp4]’, you
don’t need to put any quotation marks around the string; it will look up
the value using ‘.mp4’ as the key.  Strings beginning with a number will
be converted to an integer.  You can’t write more complicated
expressions inside a format string.

So far we’ve shown how to specify which field to substitute into the
resulting string.  The precise formatting used is also controllable by
adding a colon followed by a format specifier.  For example:

     >>> # Field 0: left justify, pad to 15 characters
     >>> # Field 1: right justify, pad to 6 characters
     >>> fmt = '{0:15} ${1:>6}'
     >>> fmt.format('Registration', 35)
     'Registration    $    35'
     >>> fmt.format('Tutorial', 50)
     'Tutorial        $    50'
     >>> fmt.format('Banquet', 125)
     'Banquet         $   125'

Format specifiers can reference other fields through nesting:

     >>> fmt = '{0:{1}}'
     >>> width = 15
     >>> fmt.format('Invoice #1234', width)
     'Invoice #1234  '
     >>> width = 35
     >>> fmt.format('Invoice #1234', width)
     'Invoice #1234                      '

The alignment of a field within the desired width can be specified:

Character            Effect
                     
----------------------------------------------------------------------
                     
< (default)          Left-align
                     
                     
>                    Right-align
                     
                     
^                    Center
                     
                     
=                    (For numeric types only) Pad after the sign.
                     

Format specifiers can also include a presentation type, which controls
how the value is formatted.  For example, floating-point numbers can be
formatted as a general number or in exponential notation:

     >>> '{0:g}'.format(3.75)
     '3.75'
     >>> '{0:e}'.format(3.75)
     '3.750000e+00'

A variety of presentation types are available.  Consult the 2.6
documentation for a *note complete list: 15a3.; here’s a sample:

‘b’       Binary.  Outputs the number in base 2.
          
          
‘c’       Character.  Converts the integer to the corresponding Unicode character
          before printing.
          
          
‘d’       Decimal Integer.  Outputs the number in base 10.
          
          
‘o’       Octal format.  Outputs the number in base 8.
          
          
‘x’       Hex format.  Outputs the number in base 16, using lower-case letters for
          the digits above 9.
          
          
‘e’       Exponent notation.  Prints the number in scientific notation using the
          letter “e” to indicate the exponent.
          
          
‘g’       General format.  This prints the number as a fixed-point number, unless
          the number is too large, in which case it switches to “e” exponent
          notation.
          
          
‘n’       Number.  This is the same as “g” (for floats) or “d” (for integers),
          except that it uses the current locale setting to insert the appropriate
          number separator characters.
          
          
‘%’       Percentage.  Multiplies the number by 100 and displays in fixed (“f”)
          format, followed by a percent sign.
          

Classes and types can define a *note __format__(): 832. method to
control how they’re formatted.  It receives a single argument, the
format specifier:

     def __format__(self, format_spec):
         if isinstance(format_spec, unicode):
             return unicode(str(self))
         else:
             return str(self)

There’s also a *note format(): 199. builtin that will format a single
value.  It calls the type’s *note __format__(): 832. method with the
provided specifier:

     >>> format(75.6564, '.2f')
     '75.66'

Vedi anche
..........

*note Format String Syntax: 15a3.

     The reference documentation for format fields.

PEP 3101(1) - Advanced String Formatting

     PEP written by Talin.  Implemented by Eric Smith.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3101/


File: python.info,  Node: PEP 3105 print As a Function,  Next: PEP 3110 Exception-Handling Changes,  Prev: PEP 3101 Advanced String Formatting,  Up: What’s New in Python 2 6

1.17.8 PEP 3105: ‘print’ As a Function
--------------------------------------

The ‘print’ statement becomes the *note print(): 1177. function in
Python 3.0.  Making *note print(): 1177. a function makes it possible to
replace the function by doing ‘def print(...)’ or importing a new
function from somewhere else.

Python 2.6 has a ‘__future__’ import that removes ‘print’ as language
syntax, letting you use the functional form instead.  For example:

     >>> from __future__ import print_function
     >>> print('# of entries', len(dictionary), file=sys.stderr)

The signature of the new function is:

     def print(*args, sep=' ', end='\n', file=None)

The parameters are:

   * 'args': positional arguments whose values will be printed out.

   * 'sep': the separator, which will be printed between arguments.

   * 'end': the ending text, which will be printed after all of the
     arguments have been output.

   * 'file': the file object to which the output will be sent.

Vedi anche
..........

PEP 3105(1) - Make print a function

     PEP written by Georg Brandl.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3105/


File: python.info,  Node: PEP 3110 Exception-Handling Changes,  Next: PEP 3112 Byte Literals,  Prev: PEP 3105 print As a Function,  Up: What’s New in Python 2 6

1.17.9 PEP 3110: Exception-Handling Changes
-------------------------------------------

One error that Python programmers occasionally make is writing the
following code:

     try:
         ...
     except TypeError, ValueError:  # Wrong!
         ...

The author is probably trying to catch both *note TypeError: 198. and
*note ValueError: 2ec. exceptions, but this code actually does something
different: it will catch *note TypeError: 198. and bind the resulting
exception object to the local name ‘"ValueError"’.  The *note
ValueError: 2ec. exception will not be caught at all.  The correct code
specifies a tuple of exceptions:

     try:
         ...
     except (TypeError, ValueError):
         ...

This error happens because the use of the comma here is ambiguous: does
it indicate two different nodes in the parse tree, or a single node
that’s a tuple?

Python 3.0 makes this unambiguous by replacing the comma with the word
«as».  To catch an exception and store the exception object in the
variable ‘exc’, you must write:

     try:
         ...
     except TypeError as exc:
         ...

Python 3.0 will only support the use of «as», and therefore interprets
the first example as catching two different exceptions.  Python 2.6
supports both the comma and «as», so existing code will continue to
work.  We therefore suggest using «as» when writing new Python code that
will only be executed with 2.6.

Vedi anche
..........

PEP 3110(1) - Catching Exceptions in Python 3000

     PEP written and implemented by Collin Winter.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3110/


File: python.info,  Node: PEP 3112 Byte Literals,  Next: PEP 3116 New I/O Library,  Prev: PEP 3110 Exception-Handling Changes,  Up: What’s New in Python 2 6

1.17.10 PEP 3112: Byte Literals
-------------------------------

Python 3.0 adopts Unicode as the language’s fundamental string type and
denotes 8-bit literals differently, either as ‘b'string'’ or using a
*note bytes: 192. constructor.  For future compatibility, Python 2.6
adds *note bytes: 192. as a synonym for the *note str: 169. type, and it
also supports the ‘b''’ notation.

The 2.6 *note str: 169. differs from 3.0’s *note bytes: 192. type in
various ways; most notably, the constructor is completely different.  In
3.0, ‘bytes([65, 66, 67])’ is 3 elements long, containing the bytes
representing ‘ABC’; in 2.6, ‘bytes([65, 66, 67])’ returns the 12-byte
string representing the *note str(): 169. of the list.

The primary use of *note bytes: 192. in 2.6 will be to write tests of
object type such as ‘isinstance(x, bytes)’.  This will help the 2to3
converter, which can’t tell whether 2.x code intends strings to contain
either characters or 8-bit bytes; you can now use either *note bytes:
192. or *note str: 169. to represent your intention exactly, and the
resulting code will also be correct in Python 3.0.

There’s also a ‘__future__’ import that causes all string literals to
become Unicode strings.  This means that ‘\u’ escape sequences can be
used to include Unicode characters:

     from __future__ import unicode_literals

     s = ('\u751f\u3080\u304e\u3000\u751f\u3054'
          '\u3081\u3000\u751f\u305f\u307e\u3054')

     print len(s)               # 12 Unicode characters

At the C level, Python 3.0 will rename the existing 8-bit string type,
called ‘PyStringObject’ in Python 2.x, to *note PyBytesObject: 996.
Python 2.6 uses ‘#define’ to support using the names *note
PyBytesObject(): 996, *note PyBytes_Check(): 15a7, *note
PyBytes_FromStringAndSize(): 15a8, and all the other functions and
macros used with strings.

Instances of the *note bytes: 192. type are immutable just as strings
are.  A new *note bytearray: 344. type stores a mutable sequence of
bytes:

     >>> bytearray([65, 66, 67])
     bytearray(b'ABC')
     >>> b = bytearray(u'\u21ef\u3244', 'utf-8')
     >>> b
     bytearray(b'\xe2\x87\xaf\xe3\x89\x84')
     >>> b[0] = '\xe3'
     >>> b
     bytearray(b'\xe3\x87\xaf\xe3\x89\x84')
     >>> unicode(str(b), 'utf-8')
     u'\u31ef \u3244'

Byte arrays support most of the methods of string types, such as *note
startswith(): 15a9./*note endswith(): 15aa, *note find(): 15ab./*note
rfind(): 15ac, and some of the methods of lists, such as *note append():
15ad, *note pop(): 15ae, and *note reverse(): 15af.

     >>> b = bytearray('ABC')
     >>> b.append('d')
     >>> b.append(ord('e'))
     >>> b
     bytearray(b'ABCde')

There’s also a corresponding C API, with *note PyByteArray_FromObject():
15b0, *note PyByteArray_FromStringAndSize(): 15b1, and various other
functions.

Vedi anche
..........

PEP 3112(1) - Bytes literals in Python 3000

     PEP written by Jason Orendorff; backported to 2.6 by Christian
     Heimes.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3112/


File: python.info,  Node: PEP 3116 New I/O Library,  Next: PEP 3118 Revised Buffer Protocol,  Prev: PEP 3112 Byte Literals,  Up: What’s New in Python 2 6

1.17.11 PEP 3116: New I/O Library
---------------------------------

Python’s built-in file objects support a number of methods, but
file-like objects don’t necessarily support all of them.  Objects that
imitate files usually support ‘read()’ and ‘write()’, but they may not
support ‘readline()’, for example.  Python 3.0 introduces a layered I/O
library in the *note io: 83. module that separates buffering and
text-handling features from the fundamental read and write operations.

There are three levels of abstract base classes provided by the *note
io: 83. module:

   * *note RawIOBase: 12d8. defines raw I/O operations: *note read():
     101f, *note readinto(): 1020, *note write(): 15b3, *note seek():
     1494, *note tell(): 15b4, *note truncate(): 1518, and *note
     close(): 507.  Most of the methods of this class will often map to
     a single system call.  There are also *note readable(): 15b5, *note
     writable(): 15b6, and *note seekable(): 15b7. methods for
     determining what operations a given object will allow.

     Python 3.0 has concrete implementations of this class for files and
     sockets, but Python 2.6 hasn’t restructured its file and socket
     objects in this way.

   * *note BufferedIOBase: 8a4. is an abstract base class that buffers
     data in memory to reduce the number of system calls used, making
     I/O processing more efficient.  It supports all of the methods of
     *note RawIOBase: 12d8, and adds a *note raw: 15b8. attribute
     holding the underlying raw object.

     There are five concrete classes implementing this ABC. *note
     BufferedWriter: 15b9. and *note BufferedReader: 1416. are for
     objects that support write-only or read-only usage that have a
     *note seek(): 1494. method for random access.  *note
     BufferedRandom: 15ba. objects support read and write access upon
     the same underlying stream, and *note BufferedRWPair: 15bb. is for
     objects such as TTYs that have both read and write operations
     acting upon unconnected streams of data.  The *note BytesIO: 10a6.
     class supports reading, writing, and seeking over an in-memory
     buffer.

   * *note TextIOBase: 8a5.: Provides functions for reading and writing
     strings (remember, strings will be Unicode in Python 3.0), and
     supporting *note universal newlines: f37.  *note TextIOBase: 8a5.
     defines the *note readline(): bf. method and supports iteration
     upon objects.

     There are two concrete implementations.  *note TextIOWrapper: 9c0.
     wraps a buffered I/O object, supporting all of the methods for text
     I/O and adding a *note buffer: 14ab. attribute for access to the
     underlying object.  *note StringIO: 112b. simply buffers everything
     in memory without ever writing anything to disk.

     (In Python 2.6, *note io.StringIO: 112b. is implemented in pure
     Python, so it’s pretty slow.  You should therefore stick with the
     existing ‘StringIO’ module or ‘cStringIO’ for now.  At some point
     Python 3.0’s *note io: 83. module will be rewritten into C for
     speed, and perhaps the C implementation will be backported to the
     2.x releases.)

In Python 2.6, the underlying implementations haven’t been restructured
to build on top of the *note io: 83. module’s classes.  The module is
being provided to make it easier to write code that’s forward-compatible
with 3.0, and to save developers the effort of writing their own
implementations of buffering and text I/O.

Vedi anche
..........

PEP 3116(1) - New I/O

     PEP written by Daniel Stutzbach, Mike Verdone, and Guido van
     Rossum.  Code by Guido van Rossum, Georg Brandl, Walter Doerwald,
     Jeremy Hylton, Martin von Löwis, Tony Lownds, and others.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3116/


File: python.info,  Node: PEP 3118 Revised Buffer Protocol,  Next: PEP 3119 Abstract Base Classes,  Prev: PEP 3116 New I/O Library,  Up: What’s New in Python 2 6

1.17.12 PEP 3118: Revised Buffer Protocol
-----------------------------------------

The buffer protocol is a C-level API that lets Python types exchange
pointers into their internal representations.  A memory-mapped file can
be viewed as a buffer of characters, for example, and this lets another
module such as *note re: be. treat memory-mapped files as a string of
characters to be searched.

The primary users of the buffer protocol are numeric-processing packages
such as NumPy, which expose the internal representation of arrays so
that callers can write data directly into an array instead of going
through a slower API. This PEP updates the buffer protocol in light of
experience from NumPy development, adding a number of new features such
as indicating the shape of an array or locking a memory region.

The most important new C API function is ‘PyObject_GetBuffer(PyObject
*obj, Py_buffer *view, int flags)’, which takes an object and a set of
flags, and fills in the ‘Py_buffer’ structure with information about the
object’s memory representation.  Objects can use this operation to lock
memory in place while an external caller could be modifying the
contents, so there’s a corresponding ‘PyBuffer_Release(Py_buffer *view)’
to indicate that the external caller is done.

The 'flags' argument to *note PyObject_GetBuffer(): 63a. specifies
constraints upon the memory returned.  Some examples are:

   * *note PyBUF_WRITABLE: 15bd. indicates that the memory must be
     writable.

   * ‘PyBUF_LOCK’ requests a read-only or exclusive lock on the memory.

   * *note PyBUF_C_CONTIGUOUS: 15be. and *note PyBUF_F_CONTIGUOUS: 15bf.
     requests a C-contiguous (last dimension varies the fastest) or
     Fortran-contiguous (first dimension varies the fastest) array
     layout.

Two new argument codes for *note PyArg_ParseTuple(): 3c1, ‘s*’ and ‘z*’,
return locked buffer objects for a parameter.

Vedi anche
..........

PEP 3118(1) - Revising the buffer protocol

     PEP written by Travis Oliphant and Carl Banks; implemented by
     Travis Oliphant.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3118/


File: python.info,  Node: PEP 3119 Abstract Base Classes,  Next: PEP 3127 Integer Literal Support and Syntax,  Prev: PEP 3118 Revised Buffer Protocol,  Up: What’s New in Python 2 6

1.17.13 PEP 3119: Abstract Base Classes
---------------------------------------

Some object-oriented languages such as Java support interfaces,
declaring that a class has a given set of methods or supports a given
access protocol.  Abstract Base Classes (or ABCs) are an equivalent
feature for Python.  The ABC support consists of an *note abc: 4. module
containing a metaclass called *note ABCMeta: 111d, special handling of
this metaclass by the *note isinstance(): 2ad. and *note issubclass():
9c6. builtins, and a collection of basic ABCs that the Python developers
think will be widely useful.  Future versions of Python will probably
add more ABCs.

Let’s say you have a particular class and wish to know whether it
supports dictionary-style access.  The phrase «dictionary-style» is
vague, however.  It probably means that accessing items with ‘obj[1]’
works.  Does it imply that setting items with ‘obj[2] = value’ works?
Or that the object will have ‘keys()’, ‘values()’, and ‘items()’
methods?  What about the iterative variants such as ‘iterkeys()’?
‘copy`and :meth:()’!update'?  Iterating over the object with ‘iter()’?

The Python 2.6 *note collections: 1e. module includes a number of
different ABCs that represent these distinctions.  ‘Iterable’ indicates
that a class defines *note __iter__(): e6b, and ‘Container’ means the
class defines a *note __contains__(): 15c1. method and therefore
supports ‘x in y’ expressions.  The basic dictionary interface of
getting items, setting items, and ‘keys()’, ‘values()’, and ‘items()’,
is defined by the ‘MutableMapping’ ABC.

You can derive your own classes from a particular ABC to indicate they
support that ABC’s interface:

     import collections

     class Storage(collections.MutableMapping):
         ...

Alternatively, you could write the class without deriving from the
desired ABC and instead register the class by calling the ABC’s *note
register(): 1290. method:

     import collections

     class Storage:
         ...

     collections.MutableMapping.register(Storage)

For classes that you write, deriving from the ABC is probably clearer.
The *note register(): 1290. method is useful when you’ve written a new
ABC that can describe an existing type or class, or if you want to
declare that some third-party class implements an ABC. For example, if
you defined a ‘PrintableType’ ABC, it’s legal to do:

     # Register Python's types
     PrintableType.register(int)
     PrintableType.register(float)
     PrintableType.register(str)

Classes should obey the semantics specified by an ABC, but Python can’t
check this; it’s up to the class author to understand the ABC’s
requirements and to implement the code accordingly.

To check whether an object supports a particular interface, you can now
write:

     def func(d):
         if not isinstance(d, collections.MutableMapping):
             raise ValueError("Mapping object expected, not %r" % d)

Don’t feel that you must now begin writing lots of checks as in the
above example.  Python has a strong tradition of duck-typing, where
explicit type-checking is never done and code simply calls methods on an
object, trusting that those methods will be there and raising an
exception if they aren’t.  Be judicious in checking for ABCs and only do
it where it’s absolutely necessary.

You can write your own ABCs by using ‘abc.ABCMeta’ as the metaclass in a
class definition:

     from abc import ABCMeta, abstractmethod

     class Drawable():
         __metaclass__ = ABCMeta

         @abstractmethod
         def draw(self, x, y, scale=1.0):
             pass

         def draw_doubled(self, x, y):
             self.draw(x, y, scale=2.0)


     class Square(Drawable):
         def draw(self, x, y, scale):
             ...

In the ‘Drawable’ ABC above, the ‘draw_doubled()’ method renders the
object at twice its size and can be implemented in terms of other
methods described in ‘Drawable’.  Classes implementing this ABC
therefore don’t need to provide their own implementation of
‘draw_doubled()’, though they can do so.  An implementation of ‘draw()’
is necessary, though; the ABC can’t provide a useful generic
implementation.

You can apply the *note @~abc.abstractmethod: 128d. decorator to methods
such as ‘draw()’ that must be implemented; Python will then raise an
exception for classes that don’t define the method.  Note that the
exception is only raised when you actually try to create an instance of
a subclass lacking the method:

     >>> class Circle(Drawable):
     ...     pass
     ...
     >>> c = Circle()
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: Can't instantiate abstract class Circle with abstract methods draw
     >>>

Abstract data attributes can be declared using the ‘@abstractproperty’
decorator:

     from abc import abstractproperty
     ...

     @abstractproperty
     def readonly(self):
        return self._x

Subclasses must then define a ‘readonly’ property.

Vedi anche
..........

PEP 3119(1) - Introducing Abstract Base Classes

     PEP written by Guido van Rossum and Talin.  Implemented by Guido
     van Rossum.  Backported to 2.6 by Benjamin Aranguren, with Alex
     Martelli.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3119/


File: python.info,  Node: PEP 3127 Integer Literal Support and Syntax,  Next: PEP 3129 Class Decorators,  Prev: PEP 3119 Abstract Base Classes,  Up: What’s New in Python 2 6

1.17.14 PEP 3127: Integer Literal Support and Syntax
----------------------------------------------------

Python 3.0 changes the syntax for octal (base-8) integer literals,
prefixing them with «0o» or «0O» instead of a leading zero, and adds
support for binary (base-2) integer literals, signalled by a «0b» or
«0B» prefix.

Python 2.6 doesn’t drop support for a leading 0 signalling an octal
number, but it does add support for «0o» and «0b»:

     >>> 0o21, 2*8 + 1
     (17, 17)
     >>> 0b101111
     47

The *note oct(): 14d6. builtin still returns numbers prefixed with a
leading zero, and a new *note bin(): 14b0. builtin returns the binary
representation for a number:

     >>> oct(42)
     '052'
     >>> future_builtins.oct(42)
     '0o52'
     >>> bin(173)
     '0b10101101'

The *note int(): 19b. and ‘long()’ builtins will now accept the «0o» and
«0b» prefixes when base-8 or base-2 are requested, or when the 'base'
argument is zero (signalling that the base used should be determined
from the string):

     >>> int ('0o52', 0)
     42
     >>> int('1101', 2)
     13
     >>> int('0b1101', 2)
     13
     >>> int('0b1101', 0)
     13

Vedi anche
..........

PEP 3127(1) - Integer Literal Support and Syntax

     PEP written by Patrick Maupin; backported to 2.6 by Eric Smith.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3127/


File: python.info,  Node: PEP 3129 Class Decorators,  Next: PEP 3141 A Type Hierarchy for Numbers,  Prev: PEP 3127 Integer Literal Support and Syntax,  Up: What’s New in Python 2 6

1.17.15 PEP 3129: Class Decorators
----------------------------------

Decorators have been extended from functions to classes.  It’s now legal
to write:

     @foo
     @bar
     class A:
       pass

This is equivalent to:

     class A:
       pass

     A = foo(bar(A))

Vedi anche
..........

PEP 3129(1) - Class Decorators

     PEP written by Collin Winter.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3129/


File: python.info,  Node: PEP 3141 A Type Hierarchy for Numbers,  Next: Other Language Changes<14>,  Prev: PEP 3129 Class Decorators,  Up: What’s New in Python 2 6

1.17.16 PEP 3141: A Type Hierarchy for Numbers
----------------------------------------------

Python 3.0 adds several abstract base classes for numeric types inspired
by Scheme’s numeric tower.  These classes were backported to 2.6 as the
*note numbers: a2. module.

The most general ABC is ‘Number’.  It defines no operations at all, and
only exists to allow checking if an object is a number by doing
‘isinstance(obj, Number)’.

‘Complex’ is a subclass of ‘Number’.  Complex numbers can undergo the
basic operations of addition, subtraction, multiplication, division, and
exponentiation, and you can retrieve the real and imaginary parts and
obtain a number’s conjugate.  Python’s built-in complex type is an
implementation of ‘Complex’.

‘Real’ further derives from ‘Complex’, and adds operations that only
work on real numbers: ‘floor()’, ‘trunc()’, rounding, taking the
remainder mod N, floor division, and comparisons.

‘Rational’ numbers derive from ‘Real’, have ‘numerator’ and
‘denominator’ properties, and can be converted to floats.  Python 2.6
adds a simple rational-number class, ‘Fraction’, in the *note fractions:
61. module.  (It’s called ‘Fraction’ instead of ‘Rational’ to avoid a
name clash with *note numbers.Rational: 14c6.)

‘Integral’ numbers derive from ‘Rational’, and can be shifted left and
right with ‘<<’ and ‘>>’, combined using bitwise operations such as ‘&’
and ‘|’, and can be used as array indexes and slice boundaries.

In Python 3.0, the PEP slightly redefines the existing builtins *note
round(): 14e2, *note math.floor(): 15c5, *note math.ceil(): 15c6, and
adds a new one, *note math.trunc(): 15c7, that’s been backported to
Python 2.6.  *note math.trunc(): 15c7. rounds toward zero, returning the
closest ‘Integral’ that’s between the function’s argument and zero.

Vedi anche
..........

PEP 3141(1) - A Type Hierarchy for Numbers

     PEP written by Jeffrey Yasskin.

Scheme's numerical tower(2), from the Guile manual.

Scheme's number datatypes(3) from the R5RS Scheme specification.

* Menu:

* The fractions Module::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3141/

   (2) 
https://www.gnu.org/software/guile/manual/html_node/Numerical-Tower.html#Numerical-Tower

   (3) 
https://conservatory.scheme.org/schemers/Documents/Standards/R5RS/HTML/r5rs-Z-H-9.html#%_sec_6.2


File: python.info,  Node: The fractions Module,  Up: PEP 3141 A Type Hierarchy for Numbers

1.17.16.1 The ‘fractions’ Module
................................

To fill out the hierarchy of numeric types, the *note fractions: 61.
module provides a rational-number class.  Rational numbers store their
values as a numerator and denominator forming a fraction, and can
exactly represent numbers such as ‘2/3’ that floating-point numbers can
only approximate.

The ‘Fraction’ constructor takes two ‘Integral’ values that will be the
numerator and denominator of the resulting fraction.

     >>> from fractions import Fraction
     >>> a = Fraction(2, 3)
     >>> b = Fraction(2, 5)
     >>> float(a), float(b)
     (0.66666666666666663, 0.40000000000000002)
     >>> a+b
     Fraction(16, 15)
     >>> a/b
     Fraction(5, 3)

For converting floating-point numbers to rationals, the float type now
has an ‘as_integer_ratio()’ method that returns the numerator and
denominator for a fraction that evaluates to the same floating-point
value:

     >>> (2.5) .as_integer_ratio()
     (5, 2)
     >>> (3.1415) .as_integer_ratio()
     (7074029114692207L, 2251799813685248L)
     >>> (1./3) .as_integer_ratio()
     (6004799503160661L, 18014398509481984L)

Note that values that can only be approximated by floating-point
numbers, such as 1./3, are not simplified to the number being
approximated; the fraction attempts to match the floating-point value
'exactly'.

The *note fractions: 61. module is based upon an implementation by
Sjoerd Mullender that was in Python’s ‘Demo/classes/’ directory for a
long time.  This implementation was significantly updated by Jeffrey
Yasskin.


File: python.info,  Node: Other Language Changes<14>,  Next: New and Improved Modules<2>,  Prev: PEP 3141 A Type Hierarchy for Numbers,  Up: What’s New in Python 2 6

1.17.17 Other Language Changes
------------------------------

Some smaller changes made to the core Python language are:

   * Directories and zip archives containing a ‘__main__.py’ file can
     now be executed directly by passing their name to the interpreter.
     The directory or zip archive is automatically inserted as the first
     entry in sys.path.  (Suggestion and initial patch by Andy Chu,
     subsequently revised by Phillip J. Eby and Nick Coghlan;
     bpo-1739468(1).)

   * The *note hasattr(): 6fa. function was catching and ignoring all
     errors, under the assumption that they meant a ‘__getattr__()’
     method was failing somehow and the return value of *note hasattr():
     6fa. would therefore be ‘False’.  This logic shouldn’t be applied
     to *note KeyboardInterrupt: bc7. and *note SystemExit: f3e,
     however; Python 2.6 will no longer discard such exceptions when
     *note hasattr(): 6fa. encounters them.  (Fixed by Benjamin
     Peterson; bpo-2196(2).)

   * When calling a function using the ‘**’ syntax to provide keyword
     arguments, you are no longer required to use a Python dictionary;
     any mapping will now work:

          >>> def f(**kw):
          ...    print sorted(kw)
          ...
          >>> ud=UserDict.UserDict()
          >>> ud['a'] = 1
          >>> ud['b'] = 'string'
          >>> f(**ud)
          ['a', 'b']

     (Contributed by Alexander Belopolsky; bpo-1686487(3).)

     It’s also become legal to provide keyword arguments after a ‘*args’
     argument to a function call.

          >>> def f(*args, **kw):
          ...     print args, kw
          ...
          >>> f(1,2,3, *(4,5,6), keyword=13)
          (1, 2, 3, 4, 5, 6) {'keyword': 13}

     Previously this would have been a syntax error.  (Contributed by
     Amaury Forgeot d’Arc; bpo-3473(4).)

   * A new builtin, ‘next(iterator, [default])’ returns the next item
     from the specified iterator.  If the 'default' argument is
     supplied, it will be returned if 'iterator' has been exhausted;
     otherwise, the *note StopIteration: df7. exception will be raised.
     (Backported in bpo-2719(5).)

   * Tuples now have *note index(): 15ca. and *note count(): 15cb.
     methods matching the list type’s *note index(): 15cc. and *note
     count(): 15cd. methods:

          >>> t = (0,1,2,3,4,0,1,2)
          >>> t.index(3)
          3
          >>> t.count(0)
          2

     (Contributed by Raymond Hettinger)

   * The built-in types now have improved support for extended slicing
     syntax, accepting various combinations of ‘(start, stop, step)’.
     Previously, the support was partial and certain corner cases
     wouldn’t work.  (Implemented by Thomas Wouters.)

   * Properties now have three attributes, ‘getter’, ‘setter’ and
     ‘deleter’, that are decorators providing useful shortcuts for
     adding a getter, setter or deleter function to an existing
     property.  You would use them like this:

          class C(object):
              @property
              def x(self):
                  return self._x

              @x.setter
              def x(self, value):
                  self._x = value

              @x.deleter
              def x(self):
                  del self._x

          class D(C):
              @C.x.getter
              def x(self):
                  return self._x * 2

              @x.setter
              def x(self, value):
                  self._x = value / 2

   * Several methods of the built-in set types now accept multiple
     iterables: ‘intersection()’, ‘intersection_update()’, ‘union()’,
     ‘update()’, ‘difference()’ and ‘difference_update()’.

          >>> s=set('1234567890')
          >>> s.intersection('abc123', 'cdf246')  # Intersection between all inputs
          set(['2'])
          >>> s.difference('246', '789')
          set(['1', '0', '3', '5'])

     (Contributed by Raymond Hettinger.)

   * Many floating-point features were added.  The *note float(): 196.
     function will now turn the string ‘nan’ into an IEEE 754 Not A
     Number value, and ‘+inf’ and ‘-inf’ into positive or negative
     infinity.  This works on any platform with IEEE 754 semantics.
     (Contributed by Christian Heimes; bpo-1635(6).)

     Other functions in the *note math: 92. module, ‘isinf()’ and
     ‘isnan()’, return true if their floating-point argument is infinite
     or Not A Number.  (bpo-1640(7))

     Conversion functions were added to convert floating-point numbers
     into hexadecimal strings (bpo-3008(8)).  These functions convert
     floats to and from a string representation without introducing
     rounding errors from the conversion between decimal and binary.
     Floats have a *note hex(): 14d7. method that returns a string
     representation, and the ‘float.fromhex()’ method converts a string
     back into a number:

          >>> a = 3.75
          >>> a.hex()
          '0x1.e000000000000p+1'
          >>> float.fromhex('0x1.e000000000000p+1')
          3.75
          >>> b=1./3
          >>> b.hex()
          '0x1.5555555555555p-2'

   * A numerical nicety: when creating a complex number from two floats
     on systems that support signed zeros (-0 and +0), the *note
     complex(): 197. constructor will now preserve the sign of the zero.
     (Fixed by Mark T. Dickinson; bpo-1507(9).)

   * Classes that inherit a ‘__hash__()’ method from a parent class can
     set ‘__hash__ = None’ to indicate that the class isn’t hashable.
     This will make ‘hash(obj)’ raise a *note TypeError: 198. and the
     class will not be indicated as implementing the ‘Hashable’ ABC.

     You should do this when you’ve defined a ‘__cmp__()’ or ‘__eq__()’
     method that compares objects by their value rather than by
     identity.  All objects have a default hash method that uses
     ‘id(obj)’ as the hash value.  There’s no tidy way to remove the
     ‘__hash__()’ method inherited from a parent class, so assigning
     ‘None’ was implemented as an override.  At the C level, extensions
     can set ‘tp_hash’ to *note PyObject_HashNotImplemented(): 15ce.
     (Fixed by Nick Coghlan and Amaury Forgeot d’Arc; bpo-2235(10).)

   * The *note GeneratorExit: 15cf. exception now subclasses *note
     BaseException: 7d8. instead of *note Exception: bcf.  This means
     that an exception handler that does ‘except Exception:’ will not
     inadvertently catch *note GeneratorExit: 15cf.  (Contributed by
     Chad Austin; bpo-1537(11).)

   * Generator objects now have a ‘gi_code’ attribute that refers to the
     original code object backing the generator.  (Contributed by Collin
     Winter; bpo-1473257(12).)

   * The *note compile(): 4b2. built-in function now accepts keyword
     arguments as well as positional parameters.  (Contributed by Thomas
     Wouters; bpo-1444529(13).)

   * The *note complex(): 197. constructor now accepts strings
     containing parenthesized complex numbers, meaning that
     ‘complex(repr(cplx))’ will now round-trip values.  For example,
     ‘complex('(3+4j)')’ now returns the value (3+4j).
     (bpo-1491866(14))

   * The string ‘translate()’ method now accepts ‘None’ as the
     translation table parameter, which is treated as the identity
     transformation.  This makes it easier to carry out operations that
     only delete characters.  (Contributed by Bengt Richter and
     implemented by Raymond Hettinger; bpo-1193128(15).)

   * The built-in *note dir(): 845. function now checks for a
     ‘__dir__()’ method on the objects it receives.  This method must
     return a list of strings containing the names of valid attributes
     for the object, and lets the object control the value that *note
     dir(): 845. produces.  Objects that have ‘__getattr__()’ or
     ‘__getattribute__()’ methods can use this to advertise
     pseudo-attributes they will honor.  (bpo-1591665(16))

   * Instance method objects have new attributes for the object and
     function comprising the method; the new synonym for ‘im_self’ is
     *note __self__: 15d0, and ‘im_func’ is also available as *note
     __func__: 1504.  The old names are still supported in Python 2.6,
     but are gone in 3.0.

   * An obscure change: when you use the *note locals(): 46f. function
     inside a *note class: 14df. statement, the resulting dictionary no
     longer returns free variables.  (Free variables, in this case, are
     variables referenced in the ‘class’ statement that aren’t
     attributes of the class.)

* Menu:

* Optimizations: Optimizations<14>.
* Interpreter Changes: Interpreter Changes<2>.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1739468

   (2) https://bugs.python.org/issue?@action=redirect&bpo=2196

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1686487

   (4) https://bugs.python.org/issue?@action=redirect&bpo=3473

   (5) https://bugs.python.org/issue?@action=redirect&bpo=2719

   (6) https://bugs.python.org/issue?@action=redirect&bpo=1635

   (7) https://bugs.python.org/issue?@action=redirect&bpo=1640

   (8) https://bugs.python.org/issue?@action=redirect&bpo=3008

   (9) https://bugs.python.org/issue?@action=redirect&bpo=1507

   (10) https://bugs.python.org/issue?@action=redirect&bpo=2235

   (11) https://bugs.python.org/issue?@action=redirect&bpo=1537

   (12) https://bugs.python.org/issue?@action=redirect&bpo=1473257

   (13) https://bugs.python.org/issue?@action=redirect&bpo=1444529

   (14) https://bugs.python.org/issue?@action=redirect&bpo=1491866

   (15) https://bugs.python.org/issue?@action=redirect&bpo=1193128

   (16) https://bugs.python.org/issue?@action=redirect&bpo=1591665


File: python.info,  Node: Optimizations<14>,  Next: Interpreter Changes<2>,  Up: Other Language Changes<14>

1.17.17.1 Optimizations
.......................

   * The *note warnings: 118. module has been rewritten in C. This makes
     it possible to invoke warnings from the parser, and may also make
     the interpreter’s startup faster.  (Contributed by Neal Norwitz and
     Brett Cannon; bpo-1631171(1).)

   * Type objects now have a cache of methods that can reduce the work
     required to find the correct method implementation for a particular
     class; once cached, the interpreter doesn’t need to traverse base
     classes to figure out the right method to call.  The cache is
     cleared if a base class or the class itself is modified, so the
     cache should remain correct even in the face of Python’s dynamic
     nature.  (Original optimization implemented by Armin Rigo, updated
     for Python 2.6 by Kevin Jacobs; bpo-1700288(2).)

     By default, this change is only applied to types that are included
     with the Python core.  Extension modules may not necessarily be
     compatible with this cache, so they must explicitly add
     ‘Py_TPFLAGS_HAVE_VERSION_TAG’ to the module’s ‘tp_flags’ field to
     enable the method cache.  (To be compatible with the method cache,
     the extension module’s code must not directly access and modify the
     ‘tp_dict’ member of any of the types it implements.  Most modules
     don’t do this, but it’s impossible for the Python interpreter to
     determine that.  See bpo-1878(3) for some discussion.)

   * Function calls that use keyword arguments are significantly faster
     by doing a quick pointer comparison, usually saving the time of a
     full string comparison.  (Contributed by Raymond Hettinger, after
     an initial implementation by Antoine Pitrou; bpo-1819(4).)

   * All of the functions in the *note struct: db. module have been
     rewritten in C, thanks to work at the Need For Speed sprint.
     (Contributed by Raymond Hettinger.)

   * Some of the standard built-in types now set a bit in their type
     objects.  This speeds up checking whether an object is a subclass
     of one of these types.  (Contributed by Neal Norwitz.)

   * Unicode strings now use faster code for detecting whitespace and
     line breaks; this speeds up the ‘split()’ method by about 25% and
     ‘splitlines()’ by 35%.  (Contributed by Antoine Pitrou.)  Memory
     usage is reduced by using pymalloc for the Unicode string’s data.

   * The ‘with’ statement now stores the *note __exit__(): 1508. method
     on the stack, producing a small speedup.  (Implemented by Jeffrey
     Yasskin.)

   * To reduce memory usage, the garbage collector will now clear
     internal free lists when garbage-collecting the highest generation
     of objects.  This may return memory to the operating system sooner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1631171

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1700288

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1878

   (4) https://bugs.python.org/issue?@action=redirect&bpo=1819


File: python.info,  Node: Interpreter Changes<2>,  Prev: Optimizations<14>,  Up: Other Language Changes<14>

1.17.17.2 Interpreter Changes
.............................

Two command-line options have been reserved for use by other Python
implementations.  The ‘-J’ switch has been reserved for use by Jython
for Jython-specific options, such as switches that are passed to the
underlying JVM. *note -X: 16f. has been reserved for options specific to
a particular implementation of Python such as CPython, Jython, or
IronPython.  If either option is used with Python 2.6, the interpreter
will report that the option isn’t currently used.

Python can now be prevented from writing ‘.pyc’ or ‘.pyo’ files by
supplying the *note -B: 15d4. switch to the Python interpreter, or by
setting the *note PYTHONDONTWRITEBYTECODE: 15d5. environment variable
before running the interpreter.  This setting is available to Python
programs as the ‘sys.dont_write_bytecode’ variable, and Python code can
change the value to modify the interpreter’s behaviour.  (Contributed by
Neal Norwitz and Georg Brandl.)

The encoding used for standard input, output, and standard error can be
specified by setting the *note PYTHONIOENCODING: 120c. environment
variable before running the interpreter.  The value should be a string
in the form ‘<encoding>’ or ‘<encoding>:<errorhandler>’.  The 'encoding'
part specifies the encoding’s name, e.g.  ‘utf-8’ or ‘latin-1’; the
optional 'errorhandler' part specifies what to do with characters that
can’t be handled by the encoding, and should be one of «error»,
«ignore», or «replace».  (Contributed by Martin von Löwis.)


File: python.info,  Node: New and Improved Modules<2>,  Next: Deprecations and Removals,  Prev: Other Language Changes<14>,  Up: What’s New in Python 2 6

1.17.18 New and Improved Modules
--------------------------------

As in every release, Python’s standard library received a number of
enhancements and bug fixes.  Here’s a partial list of the most notable
changes, sorted alphabetically by module name.  Consult the ‘Misc/NEWS’
file in the source tree for a more complete list of changes, or look
through the Subversion logs for all the details.

   * The ‘asyncore’ and ‘asynchat’ modules are being actively maintained
     again, and a number of patches and bugfixes were applied.
     (Maintained by Josiah Carlson; see bpo-1736190(1) for one patch.)

   * The ‘bsddb’ module also has a new maintainer, Jesús Cea Avión, and
     the package is now available as a standalone package.  The web page
     for the package is www.jcea.es/programacion/pybsddb.htm(2).  The
     plan is to remove the package from the standard library in Python
     3.0, because its pace of releases is much more frequent than
     Python’s.

     The ‘bsddb.dbshelve’ module now uses the highest pickling protocol
     available, instead of restricting itself to protocol 1.
     (Contributed by W. Barnes.)

   * The ‘cgi’ module will now read variables from the query string of
     an HTTP POST request.  This makes it possible to use form actions
     with URLs that include query strings such as
     «/cgi-bin/add.py?category=1».  (Contributed by Alexandre Fiori and
     Nubis; bpo-1817(3).)

     The ‘parse_qs()’ and ‘parse_qsl()’ functions have been relocated
     from the ‘cgi’ module to the *note urlparse: 110. module.  The
     versions still available in the ‘cgi’ module will trigger *note
     PendingDeprecationWarning: ac8. messages in 2.6 (bpo-600362(4)).

   * The *note cmath: 19. module underwent extensive revision,
     contributed by Mark Dickinson and Christian Heimes.  Five new
     functions were added:

        * ‘polar()’ converts a complex number to polar form, returning
          the modulus and argument of the complex number.

        * ‘rect()’ does the opposite, turning a modulus, argument pair
          back into the corresponding complex number.

        * ‘phase()’ returns the argument (also called the angle) of a
          complex number.

        * ‘isnan()’ returns True if either the real or imaginary part of
          its argument is a NaN.

        * ‘isinf()’ returns True if either the real or imaginary part of
          its argument is infinite.

     The revisions also improved the numerical soundness of the *note
     cmath: 19. module.  For all functions, the real and imaginary parts
     of the results are accurate to within a few units of least
     precision (ulps) whenever possible.  See bpo-1381(5) for the
     details.  The branch cuts for ‘asinh()’, ‘atanh()’: and ‘atan()’
     have also been corrected.

     The tests for the module have been greatly expanded; nearly 2000
     new test cases exercise the algebraic functions.

     On IEEE 754 platforms, the *note cmath: 19. module now handles IEEE
     754 special values and floating-point exceptions in a manner
     consistent with Annex “G” of the C99 standard.

   * A new data type in the *note collections: 1e. module:
     ‘namedtuple(typename, fieldnames)’ is a factory function that
     creates subclasses of the standard tuple whose fields are
     accessible by name as well as index.  For example:

          >>> var_type = collections.namedtuple('variable',
          ...             'id name type size')
          >>> # Names are separated by spaces or commas.
          >>> # 'id, name, type, size' would also work.
          >>> var_type._fields
          ('id', 'name', 'type', 'size')

          >>> var = var_type(1, 'frequency', 'int', 4)
          >>> print var[0], var.id    # Equivalent
          1 1
          >>> print var[2], var.type  # Equivalent
          int int
          >>> var._asdict()
          {'size': 4, 'type': 'int', 'id': 1, 'name': 'frequency'}
          >>> v2 = var._replace(name='amplitude')
          >>> v2
          variable(id=1, name='amplitude', type='int', size=4)

     Several places in the standard library that returned tuples have
     been modified to return ‘namedtuple()’ instances.  For example, the
     ‘Decimal.as_tuple()’ method now returns a named tuple with ‘sign’,
     ‘digits’, and ‘exponent’ fields.

     (Contributed by Raymond Hettinger.)

   * Another change to the *note collections: 1e. module is that the
     ‘deque’ type now supports an optional 'maxlen' parameter; if
     supplied, the deque’s size will be restricted to no more than
     'maxlen' items.  Adding more items to a full deque causes old items
     to be discarded.

          >>> from collections import deque
          >>> dq=deque(maxlen=3)
          >>> dq
          deque([], maxlen=3)
          >>> dq.append(1); dq.append(2); dq.append(3)
          >>> dq
          deque([1, 2, 3], maxlen=3)
          >>> dq.append(4)
          >>> dq
          deque([2, 3, 4], maxlen=3)

     (Contributed by Raymond Hettinger.)

   * The *note Cookie: 75. module’s *note Morsel: e00. objects now
     support an *note httponly: 15d7. attribute.  In some browsers.
     cookies with this attribute set cannot be accessed or manipulated
     by JavaScript code.  (Contributed by Arvin Schnell;
     bpo-1638033(6).)

   * A new window method in the *note curses: 2f. module, ‘chgat()’,
     changes the display attributes for a certain number of characters
     on a single line.  (Contributed by Fabian Kreutz.)

          # Boldface text starting at y=0,x=21
          # and affecting the rest of the line.
          stdscr.chgat(0, 21, curses.A_BOLD)

     The ‘Textbox’ class in the *note curses.textpad: 32. module now
     supports editing in insert mode as well as overwrite mode.  Insert
     mode is enabled by supplying a true value for the 'insert_mode'
     parameter when creating the ‘Textbox’ instance.

   * The *note datetime: 34. module’s ‘strftime()’ methods now support a
     ‘%f’ format code that expands to the number of microseconds in the
     object, zero-padded on the left to six places.  (Contributed by
     Skip Montanaro; bpo-1158(7).)

   * The *note decimal: 3a. module was updated to version 1.66 of the
     General Decimal Specification(8).  New features include some
     methods for some basic mathematical functions such as ‘exp()’ and
     ‘log10()’:

          >>> Decimal(1).exp()
          Decimal("2.718281828459045235360287471")
          >>> Decimal("2.7182818").ln()
          Decimal("0.9999999895305022877376682436")
          >>> Decimal(1000).log10()
          Decimal("3")

     The ‘as_tuple()’ method of ‘Decimal’ objects now returns a named
     tuple with ‘sign’, ‘digits’, and ‘exponent’ fields.

     (Implemented by Facundo Batista and Mark Dickinson.  Named tuple
     support added by Raymond Hettinger.)

   * The *note difflib: 3b. module’s ‘SequenceMatcher’ class now returns
     named tuples representing matches, with ‘a’, ‘b’, and ‘size’
     attributes.  (Contributed by Raymond Hettinger.)

   * An optional ‘timeout’ parameter, specifying a timeout measured in
     seconds, was added to the *note ftplib.FTP: af8. class constructor
     as well as the ‘connect()’ method.  (Added by Facundo Batista.)
     Also, the ‘FTP’ class’s ‘storbinary()’ and ‘storlines()’ now take
     an optional 'callback' parameter that will be called with each
     block of data after the data has been sent.  (Contributed by Phil
     Schwartz; bpo-1221598(9).)

   * The ‘reduce()’ built-in function is also available in the *note
     functools: 63. module.  In Python 3.0, the builtin has been dropped
     and ‘reduce()’ is only available from *note functools: 63.;
     currently there are no plans to drop the builtin in the 2.x series.
     (Patched by Christian Heimes; bpo-1739906(10).)

   * When possible, the *note getpass: 66. module will now use
     ‘/dev/tty’ to print a prompt message and read the password, falling
     back to standard error and standard input.  If the password may be
     echoed to the terminal, a warning is printed before the prompt is
     displayed.  (Contributed by Gregory P. Smith.)

   * The *note glob.glob(): 5a0. function can now return Unicode
     filenames if a Unicode path was used and Unicode filenames are
     matched within the directory.  (bpo-1001604(11))

   * A new function in the *note heapq: 6d. module, ‘merge(iter1, iter2,
     ...)’, takes any number of iterables returning data in sorted
     order, and returns a new generator that returns the contents of all
     the iterators, also in sorted order.  For example:

          >>> list(heapq.merge([1, 3, 5, 9], [2, 8, 16]))
          [1, 2, 3, 5, 8, 9, 16]

     Another new function, ‘heappushpop(heap, item)’, pushes 'item' onto
     'heap', then pops off and returns the smallest item.  This is more
     efficient than making a call to ‘heappush()’ and then ‘heappop()’.

     *note heapq: 6d. is now implemented to only use less-than
     comparison, instead of the less-than-or-equal comparison it
     previously used.  This makes *note heapq: 6d.’s usage of a type
     match the *note list.sort(): dca. method.  (Contributed by Raymond
     Hettinger.)

   * An optional ‘timeout’ parameter, specifying a timeout measured in
     seconds, was added to the *note httplib.HTTPConnection: d37. and
     *note HTTPSConnection: d38. class constructors.  (Added by Facundo
     Batista.)

   * Most of the *note inspect: 82. module’s functions, such as
     ‘getmoduleinfo()’ and ‘getargs()’, now return named tuples.  In
     addition to behaving like tuples, the elements of the return value
     can also be accessed as attributes.  (Contributed by Raymond
     Hettinger.)

     Some new functions in the module include ‘isgenerator()’,
     ‘isgeneratorfunction()’, and ‘isabstract()’.

   * The *note itertools: 85. module gained several new functions.

     ‘izip_longest(iter1, iter2, ...[, fillvalue])’ makes tuples from
     each of the elements; if some of the iterables are shorter than
     others, the missing values are set to 'fillvalue'.  For example:

          >>> tuple(itertools.izip_longest([1,2,3], [1,2,3,4,5]))
          ((1, 1), (2, 2), (3, 3), (None, 4), (None, 5))

     ‘product(iter1, iter2, ..., [repeat=N])’ returns the Cartesian
     product of the supplied iterables, a set of tuples containing every
     possible combination of the elements returned from each iterable.

          >>> list(itertools.product([1,2,3], [4,5,6]))
          [(1, 4), (1, 5), (1, 6),
           (2, 4), (2, 5), (2, 6),
           (3, 4), (3, 5), (3, 6)]

     The optional 'repeat' keyword argument is used for taking the
     product of an iterable or a set of iterables with themselves,
     repeated 'N' times.  With a single iterable argument, 'N'-tuples
     are returned:

          >>> list(itertools.product([1,2], repeat=3))
          [(1, 1, 1), (1, 1, 2), (1, 2, 1), (1, 2, 2),
           (2, 1, 1), (2, 1, 2), (2, 2, 1), (2, 2, 2)]

     With two iterables, '2N'-tuples are returned.

          >>> list(itertools.product([1,2], [3,4], repeat=2))
          [(1, 3, 1, 3), (1, 3, 1, 4), (1, 3, 2, 3), (1, 3, 2, 4),
           (1, 4, 1, 3), (1, 4, 1, 4), (1, 4, 2, 3), (1, 4, 2, 4),
           (2, 3, 1, 3), (2, 3, 1, 4), (2, 3, 2, 3), (2, 3, 2, 4),
           (2, 4, 1, 3), (2, 4, 1, 4), (2, 4, 2, 3), (2, 4, 2, 4)]

     ‘combinations(iterable, r)’ returns sub-sequences of length 'r'
     from the elements of 'iterable'.

          >>> list(itertools.combinations('123', 2))
          [('1', '2'), ('1', '3'), ('2', '3')]
          >>> list(itertools.combinations('123', 3))
          [('1', '2', '3')]
          >>> list(itertools.combinations('1234', 3))
          [('1', '2', '3'), ('1', '2', '4'),
           ('1', '3', '4'), ('2', '3', '4')]

     ‘permutations(iter[, r])’ returns all the permutations of length
     'r' of the iterable’s elements.  If 'r' is not specified, it will
     default to the number of elements produced by the iterable.

          >>> list(itertools.permutations([1,2,3,4], 2))
          [(1, 2), (1, 3), (1, 4),
           (2, 1), (2, 3), (2, 4),
           (3, 1), (3, 2), (3, 4),
           (4, 1), (4, 2), (4, 3)]

     ‘itertools.chain(*iterables)’ is an existing function in *note
     itertools: 85. that gained a new constructor in Python 2.6.
     ‘itertools.chain.from_iterable(iterable)’ takes a single iterable
     that should return other iterables.  ‘chain()’ will then return all
     the elements of the first iterable, then all the elements of the
     second, and so on.

          >>> list(itertools.chain.from_iterable([[1,2,3], [4,5,6]]))
          [1, 2, 3, 4, 5, 6]

     (All contributed by Raymond Hettinger.)

   * The *note logging: 8b. module’s ‘FileHandler’ class and its
     subclasses ‘WatchedFileHandler’, ‘RotatingFileHandler’, and
     ‘TimedRotatingFileHandler’ now have an optional 'delay' parameter
     to their constructors.  If 'delay' is true, opening of the log file
     is deferred until the first ‘emit()’ call is made.  (Contributed by
     Vinay Sajip.)

     ‘TimedRotatingFileHandler’ also has a 'utc' constructor parameter.
     If the argument is true, UTC time will be used in determining when
     midnight occurs and in generating filenames; otherwise local time
     will be used.

   * Several new functions were added to the *note math: 92. module:

        * *note isinf(): 15d8. and *note isnan(): 15d9. determine
          whether a given float is a (positive or negative) infinity or
          a NaN (Not a Number), respectively.

        * *note copysign(): 15da. copies the sign bit of an IEEE 754
          number, returning the absolute value of 'x' combined with the
          sign bit of 'y'.  For example, ‘math.copysign(1, -0.0)’
          returns -1.0.  (Contributed by Christian Heimes.)

        * *note factorial(): b43. computes the factorial of a number.
          (Contributed by Raymond Hettinger; bpo-2138(12).)

        * *note fsum(): 15db. adds up the stream of numbers from an
          iterable, and is careful to avoid loss of precision through
          using partial sums.  (Contributed by Jean Brouwers, Raymond
          Hettinger, and Mark Dickinson; bpo-2819(13).)

        * *note acosh(): 15dc, *note asinh(): 15dd. and *note atanh():
          15de. compute the inverse hyperbolic functions.

        * *note log1p(): 15df. returns the natural logarithm of '1+x'
          (base 'e').

        * ‘trunc()’ rounds a number toward zero, returning the closest
          ‘Integral’ that’s between the function’s argument and zero.
          Added as part of the backport of *note PEP 3141's type
          hierarchy for numbers: 14c5.

   * The *note math: 92. module has been improved to give more
     consistent behaviour across platforms, especially with respect to
     handling of floating-point exceptions and IEEE 754 special values.

     Whenever possible, the module follows the recommendations of the
     C99 standard about 754’s special values.  For example, ‘sqrt(-1.)’
     should now give a *note ValueError: 2ec. across almost all
     platforms, while ‘sqrt(float('NaN'))’ should return a NaN on all
     IEEE 754 platforms.  Where Annex “F” of the C99 standard recommends
     signaling “divide-by-zero” or “invalid”, Python will raise *note
     ValueError: 2ec.  Where Annex “F” of the C99 standard recommends
     signaling “overflow”, Python will raise *note OverflowError: a83.
     (See bpo-711019(14) and bpo-1640(15).)

     (Contributed by Christian Heimes and Mark Dickinson.)

   * *note mmap: 51a. objects now have a ‘rfind()’ method that searches
     for a substring beginning at the end of the string and searching
     backwards.  The ‘find()’ method also gained an 'end' parameter
     giving an index at which to stop searching.  (Contributed by John
     Lenton.)

   * The *note operator: a3. module gained a ‘methodcaller()’ function
     that takes a name and an optional set of arguments, returning a
     callable that will call the named function on any arguments passed
     to it.  For example:

          >>> # Equivalent to lambda s: s.replace('old', 'new')
          >>> replacer = operator.methodcaller('replace', 'old', 'new')
          >>> replacer('old wine in old bottles')
          'new wine in new bottles'

     (Contributed by Georg Brandl, after a suggestion by Gregory
     Petrosyan.)

     The ‘attrgetter()’ function now accepts dotted names and performs
     the corresponding attribute lookups:

          >>> inst_name = operator.attrgetter(
          ...        '__class__.__name__')
          >>> inst_name('')
          'str'
          >>> inst_name(help)
          '_Helper'

     (Contributed by Georg Brandl, after a suggestion by Barry Warsaw.)

   * The *note os: a5. module now wraps several new system calls.
     ‘fchmod(fd, mode)’ and ‘fchown(fd, uid, gid)’ change the mode and
     ownership of an opened file, and ‘lchmod(path, mode)’ changes the
     mode of a symlink.  (Contributed by Georg Brandl and Christian
     Heimes.)

     ‘chflags()’ and ‘lchflags()’ are wrappers for the corresponding
     system calls (where they’re available), changing the flags set on a
     file.  Constants for the flag values are defined in the *note stat:
     d6. module; some possible values include ‘UF_IMMUTABLE’ to signal
     the file may not be changed and ‘UF_APPEND’ to indicate that data
     can only be appended to the file.  (Contributed by M. Levinson.)

     ‘os.closerange(low, high)’ efficiently closes all file descriptors
     from 'low' to 'high', ignoring any errors and not including 'high'
     itself.  This function is now used by the *note subprocess: dc.
     module to make starting processes faster.  (Contributed by Georg
     Brandl; bpo-1663329(16).)

   * The ‘os.environ’ object’s ‘clear()’ method will now unset the
     environment variables using *note os.unsetenv(): 25c. in addition
     to clearing the object’s keys.  (Contributed by Martin Horcicka;
     bpo-1181(17).)

   * The *note os.walk(): 6d1. function now has a ‘followlinks’
     parameter.  If set to True, it will follow symlinks pointing to
     directories and visit the directory’s contents.  For backward
     compatibility, the parameter’s default value is false.  Note that
     the function can fall into an infinite recursion if there’s a
     symlink that points to a parent directory.  (bpo-1273829(18))

   * In the *note os.path: a6. module, the ‘splitext()’ function has
     been changed to not split on leading period characters.  This
     produces better results when operating on Unix’s dot-files.  For
     example, ‘os.path.splitext('.ipython')’ now returns ‘('.ipython',
     '')’ instead of ‘('', '.ipython')’.  (bpo-1115886(19))

     A new function, ‘os.path.relpath(path, start='.')’, returns a
     relative path from the ‘start’ path, if it’s supplied, or from the
     current working directory to the destination ‘path’.  (Contributed
     by Richard Barran; bpo-1339796(20).)

     On Windows, *note os.path.expandvars(): 15e0. will now expand
     environment variables given in the form «%var%», and «~user» will
     be expanded into the user’s home directory path.  (Contributed by
     Josiah Carlson; bpo-957650(21).)

   * The Python debugger provided by the *note pdb: aa. module gained a
     new command: «run» restarts the Python program being debugged and
     can optionally take new command-line arguments for the program.
     (Contributed by Rocky Bernstein; bpo-1393667(22).)

   * The *note pdb.post_mortem(): 15e1. function, used to begin
     debugging a traceback, will now use the traceback returned by *note
     sys.exc_info(): 89b. if no traceback is supplied.  (Contributed by
     Facundo Batista; bpo-1106316(23).)

   * The *note pickletools: ac. module now has an ‘optimize()’ function
     that takes a string containing a pickle and removes some unused
     opcodes, returning a shorter pickle that contains the same data
     structure.  (Contributed by Raymond Hettinger.)

   * A ‘get_data()’ function was added to the *note pkgutil: ae. module
     that returns the contents of resource files included with an
     installed Python package.  For example:

          >>> import pkgutil
          >>> print pkgutil.get_data('test', 'exception_hierarchy.txt')
          BaseException
           +-- SystemExit
           +-- KeyboardInterrupt
           +-- GeneratorExit
           +-- Exception
                +-- StopIteration
                +-- StandardError
           ...

     (Contributed by Paul Moore; bpo-2439(24).)

   * The ‘pyexpat’ module’s ‘Parser’ objects now allow setting their
     ‘buffer_size’ attribute to change the size of the buffer used to
     hold character data.  (Contributed by Achim Gaedke; bpo-1137(25).)

   * The ‘Queue’ module now provides queue variants that retrieve
     entries in different orders.  The ‘PriorityQueue’ class stores
     queued items in a heap and retrieves them in priority order, and
     ‘LifoQueue’ retrieves the most recently added entries first,
     meaning that it behaves like a stack.  (Contributed by Raymond
     Hettinger.)

   * The *note random: bd. module’s ‘Random’ objects can now be pickled
     on a 32-bit system and unpickled on a 64-bit system, and vice
     versa.  Unfortunately, this change also means that Python 2.6’s
     ‘Random’ objects can’t be unpickled correctly on earlier versions
     of Python.  (Contributed by Shawn Ligocki; bpo-1727780(26).)

     The new ‘triangular(low, high, mode)’ function returns random
     numbers following a triangular distribution.  The returned values
     are between 'low' and 'high', not including 'high' itself, and with
     'mode' as the most frequently occurring value in the distribution.
     (Contributed by Wladmir van der Laan and Raymond Hettinger;
     bpo-1681432(27).)

   * Long regular expression searches carried out by the *note re: be.
     module will check for signals being delivered, so time-consuming
     searches can now be interrupted.  (Contributed by Josh Hoyt and
     Ralf Schmitt; bpo-846388(28).)

     The regular expression module is implemented by compiling bytecodes
     for a tiny regex-specific virtual machine.  Untrusted code could
     create malicious strings of bytecode directly and cause crashes, so
     Python 2.6 includes a verifier for the regex bytecode.
     (Contributed by Guido van Rossum from work for Google App Engine;
     bpo-3487(29).)

   * The *note rlcompleter: c2. module’s ‘Completer.complete()’ method
     will now ignore exceptions triggered while evaluating a name.
     (Fixed by Lorenz Quack; bpo-2250(30).)

   * The *note sched: c4. module’s ‘scheduler’ instances now have a
     read-only *note queue: bb. attribute that returns the contents of
     the scheduler’s queue, represented as a list of named tuples with
     the fields ‘(time, priority, action, argument)’.  (Contributed by
     Raymond Hettinger; bpo-1861(31).)

   * The *note select: c6. module now has wrapper functions for the
     Linux ‘epoll()’ and BSD ‘kqueue()’ system calls.  ‘modify()’ method
     was added to the existing ‘poll’ objects; ‘pollobj.modify(fd,
     eventmask)’ takes a file descriptor or file object and an event
     mask, modifying the recorded event mask for that file.
     (Contributed by Christian Heimes; bpo-1657(32).)

   * The *note shutil.copytree(): c20. function now has an optional
     'ignore' argument that takes a callable object.  This callable will
     receive each directory path and a list of the directory’s contents,
     and returns a list of names that will be ignored, not copied.

     The *note shutil: ca. module also provides an ‘ignore_patterns()’
     function for use with this new parameter.  ‘ignore_patterns()’
     takes an arbitrary number of glob-style patterns and returns a
     callable that will ignore any files and directories that match any
     of these patterns.  The following example copies a directory tree,
     but skips both ‘.svn’ directories and Emacs backup files, which
     have names ending with “~”:

          shutil.copytree('Doc/library', '/tmp/library',
                          ignore=shutil.ignore_patterns('*~', '.svn'))

     (Contributed by Tarek Ziadé; bpo-2663(33).)

   * Integrating signal handling with GUI handling event loops like
     those used by Tkinter or GTk+ has long been a problem; most
     software ends up polling, waking up every fraction of a second to
     check if any GUI events have occurred.  The *note signal: cb.
     module can now make this more efficient.  Calling
     ‘signal.set_wakeup_fd(fd)’ sets a file descriptor to be used; when
     a signal is received, a byte is written to that file descriptor.
     There’s also a C-level function, *note PySignal_SetWakeupFd():
     15e2, for setting the descriptor.

     Event loops will use this by opening a pipe to create two
     descriptors, one for reading and one for writing.  The writable
     descriptor will be passed to ‘set_wakeup_fd()’, and the readable
     descriptor will be added to the list of descriptors monitored by
     the event loop via ‘select()’ or ‘poll()’.  On receiving a signal,
     a byte will be written and the main event loop will be woken up,
     avoiding the need to poll.

     (Contributed by Adam Olsen; bpo-1583(34).)

     The ‘siginterrupt()’ function is now available from Python code,
     and allows changing whether signals can interrupt system calls or
     not.  (Contributed by Ralf Schmitt.)

     The ‘setitimer()’ and ‘getitimer()’ functions have also been added
     (where they’re available).  ‘setitimer()’ allows setting interval
     timers that will cause a signal to be delivered to the process
     after a specified time, measured in wall-clock time, consumed
     process time, or combined process+system time.  (Contributed by
     Guilherme Polo; bpo-2240(35).)

   * The *note smtplib: cf. module now supports SMTP over SSL thanks to
     the addition of the ‘SMTP_SSL’ class.  This class supports an
     interface identical to the existing ‘SMTP’ class.  (Contributed by
     Monty Taylor.)  Both class constructors also have an optional
     ‘timeout’ parameter that specifies a timeout for the initial
     connection attempt, measured in seconds.  (Contributed by Facundo
     Batista.)

     An implementation of the LMTP protocol ( RFC 2033(36)) was also
     added to the module.  LMTP is used in place of SMTP when
     transferring e-mail between agents that don’t manage a mail queue.
     (LMTP implemented by Leif Hedstrom; bpo-957003(37).)

     ‘SMTP.starttls()’ now complies with RFC 3207(38) and forgets any
     knowledge obtained from the server not obtained from the TLS
     negotiation itself.  (Patch contributed by Bill Fenner;
     bpo-829951(39).)

   * The *note socket: d1. module now supports TIPC
     (‘https://tipc.sourceforge.net/’), a high-performance non-IP-based
     protocol designed for use in clustered environments.  TIPC
     addresses are 4- or 5-tuples.  (Contributed by Alberto Bertogli;
     bpo-1646(40).)

     A new function, ‘create_connection()’, takes an address and
     connects to it using an optional timeout value, returning the
     connected socket object.  This function also looks up the address’s
     type and connects to it using IPv4 or IPv6 as appropriate.
     Changing your code to use ‘create_connection()’ instead of
     ‘socket(socket.AF_INET, ...)’ may be all that’s required to make
     your code work with IPv6.

   * The base classes in the *note SocketServer: d2. module now support
     calling a *note handle_timeout(): 1529. method after a span of
     inactivity specified by the server’s *note timeout: 1528.
     attribute.  (Contributed by Michael Pomraning.)  The *note
     serve_forever(): 1347. method now takes an optional poll interval
     measured in seconds, controlling how often the server will check
     for a shutdown request.  (Contributed by Pedro Werneck and Jeffrey
     Yasskin; bpo-742598(41), bpo-1193577(42).)

   * The *note sqlite3: d4. module, maintained by Gerhard Häring, has
     been updated from version 2.3.2 in Python 2.5 to version 2.4.1.

   * The *note struct: db. module now supports the C99 _Bool type, using
     the format character ‘'?'’.  (Contributed by David Remahl.)

   * The *note Popen: 4b8. objects provided by the *note subprocess: dc.
     module now have *note terminate(): 15e3, *note kill(): 15e4, and
     *note send_signal(): 15e5. methods.  On Windows, ‘send_signal()’
     only supports the *note SIGTERM: 15e6. signal, and all these
     methods are aliases for the Win32 API function
     ‘TerminateProcess()’.  (Contributed by Christian Heimes.)

   * A new variable in the *note sys: df. module, ‘float_info’, is an
     object containing information derived from the ‘float.h’ file about
     the platform’s floating-point support.  Attributes of this object
     include ‘mant_dig’ (number of digits in the mantissa), ‘epsilon’
     (smallest difference between 1.0 and the next largest value
     representable), and several others.  (Contributed by Christian
     Heimes; bpo-1534(43).)

     Another new variable, ‘dont_write_bytecode’, controls whether
     Python writes any ‘.pyc’ or ‘.pyo’ files on importing a module.  If
     this variable is true, the compiled files are not written.  The
     variable is initially set on start-up by supplying the *note -B:
     15d4. switch to the Python interpreter, or by setting the *note
     PYTHONDONTWRITEBYTECODE: 15d5. environment variable before running
     the interpreter.  Python code can subsequently change the value of
     this variable to control whether bytecode files are written or not.
     (Contributed by Neal Norwitz and Georg Brandl.)

     Information about the command-line arguments supplied to the Python
     interpreter is available by reading attributes of a named tuple
     available as ‘sys.flags’.  For example, the ‘verbose’ attribute is
     true if Python was executed in verbose mode, ‘debug’ is true in
     debugging mode, etc.  These attributes are all read-only.
     (Contributed by Christian Heimes.)

     A new function, ‘getsizeof()’, takes a Python object and returns
     the amount of memory used by the object, measured in bytes.
     Built-in objects return correct results; third-party extensions may
     not, but can define a ‘__sizeof__()’ method to return the object’s
     size.  (Contributed by Robert Schuppenies; bpo-2898(44).)

     It’s now possible to determine the current profiler and tracer
     functions by calling *note sys.getprofile(): 15e7. and *note
     sys.gettrace(): 15e8.  (Contributed by Georg Brandl; bpo-1648(45).)

   * The *note tarfile: e4. module now supports POSIX.1-2001 (pax)
     tarfiles in addition to the POSIX.1-1988 (ustar) and GNU tar
     formats that were already supported.  The default format is GNU
     tar; specify the ‘format’ parameter to open a file using a
     different format:

          tar = tarfile.open("output.tar", "w",
                             format=tarfile.PAX_FORMAT)

     The new ‘encoding’ and ‘errors’ parameters specify an encoding and
     an error handling scheme for character conversions.  ‘'strict'’,
     ‘'ignore'’, and ‘'replace'’ are the three standard ways Python can
     handle errors,; ‘'utf-8'’ is a special value that replaces bad
     characters with their UTF-8 representation.  (Character conversions
     occur because the PAX format supports Unicode filenames, defaulting
     to UTF-8 encoding.)

     The ‘TarFile.add()’ method now accepts an ‘exclude’ argument that’s
     a function that can be used to exclude certain filenames from an
     archive.  The function must take a filename and return true if the
     file should be excluded or false if it should be archived.  The
     function is applied to both the name initially passed to ‘add()’
     and to the names of files in recursively added directories.

     (All changes contributed by Lars Gustäbel).

   * An optional ‘timeout’ parameter was added to the ‘telnetlib.Telnet’
     class constructor, specifying a timeout measured in seconds.
     (Added by Facundo Batista.)

   * The *note tempfile.NamedTemporaryFile: 6ee. class usually deletes
     the temporary file it created when the file is closed.  This
     behaviour can now be changed by passing ‘delete=False’ to the
     constructor.  (Contributed by Damien Miller; bpo-1537850(46).)

     A new class, ‘SpooledTemporaryFile’, behaves like a temporary file
     but stores its data in memory until a maximum size is exceeded.  On
     reaching that limit, the contents will be written to an on-disk
     temporary file.  (Contributed by Dustin J. Mitchell.)

     The ‘NamedTemporaryFile’ and ‘SpooledTemporaryFile’ classes both
     work as context managers, so you can write ‘with
     tempfile.NamedTemporaryFile() as tmp: ...’.  (Contributed by
     Alexander Belopolsky; bpo-2021(47).)

   * The *note test.test_support: ea. module gained a number of context
     managers useful for writing tests.  *note EnvironmentVarGuard():
     15e9. is a context manager that temporarily changes environment
     variables and automatically restores them to their old values.

     Another context manager, ‘TransientResource’, can surround calls to
     resources that may or may not be available; it will catch and
     ignore a specified list of exceptions.  For example, a network test
     may ignore certain failures when connecting to an external web
     site:

          with test_support.TransientResource(IOError,
                                          errno=errno.ETIMEDOUT):
              f = urllib.urlopen('https://sf.net')
              ...

     Finally, ‘check_warnings()’ resets the ‘warning’ module’s warning
     filters and returns an object that will record all warning messages
     triggered (bpo-3781(48)):

          with test_support.check_warnings() as wrec:
              warnings.simplefilter("always")
              # ... code that triggers a warning ...
              assert str(wrec.message) == "function is outdated"
              assert len(wrec.warnings) == 1, "Multiple warnings raised"

     (Contributed by Brett Cannon.)

   * The *note textwrap: f2. module can now preserve existing whitespace
     at the beginnings and ends of the newly created lines by specifying
     ‘drop_whitespace=False’ as an argument:

          >>> S = """This  sentence  has a bunch   of
          ...   extra   whitespace."""
          >>> print textwrap.fill(S, width=15)
          This  sentence
          has a bunch
          of    extra
          whitespace.
          >>> print textwrap.fill(S, drop_whitespace=False, width=15)
          This  sentence
            has a bunch
             of    extra
             whitespace.
          >>>

     (Contributed by Dwayne Bailey; bpo-1581073(49).)

   * The *note threading: f3. module API is being changed to use
     properties such as ‘daemon’ instead of ‘setDaemon()’ and
     ‘isDaemon()’ methods, and some methods have been renamed to use
     underscores instead of camel-case; for example, the ‘activeCount()’
     method is renamed to ‘active_count()’.  Both the 2.6 and 3.0
     versions of the module support the same properties and renamed
     methods, but don’t remove the old methods.  No date has been set
     for the deprecation of the old APIs in Python 3.x; the old APIs
     won’t be removed in any 2.x version.  (Carried out by several
     people, most notably Benjamin Peterson.)

     The *note threading: f3. module’s ‘Thread’ objects gained an
     ‘ident’ property that returns the thread’s identifier, a nonzero
     integer.  (Contributed by Gregory P. Smith; bpo-2871(50).)

   * The *note timeit: f5. module now accepts callables as well as
     strings for the statement being timed and for the setup code.  Two
     convenience functions were added for creating ‘Timer’ instances:
     ‘repeat(stmt, setup, time, repeat, number)’ and ‘timeit(stmt,
     setup, time, number)’ create an instance and call the corresponding
     method.  (Contributed by Erik Demaine; bpo-1533909(51).)

   * The ‘Tkinter’ module now accepts lists and tuples for options,
     separating the elements by spaces before passing the resulting
     value to Tcl/Tk.  (Contributed by Guilherme Polo; bpo-2906(52).)

   * The *note turtle: 107. module for turtle graphics was greatly
     enhanced by Gregor Lingl.  New features in the module include:

        * Better animation of turtle movement and rotation.

        * Control over turtle movement using the new ‘delay()’,
          ‘tracer()’, and ‘speed()’ methods.

        * The ability to set new shapes for the turtle, and to define a
          new coordinate system.

        * Turtles now have an ‘undo()’ method that can roll back
          actions.

        * Simple support for reacting to input events such as mouse and
          keyboard activity, making it possible to write simple games.

        * A ‘turtle.cfg’ file can be used to customize the starting
          appearance of the turtle’s screen.

        * The module’s docstrings can be replaced by new docstrings that
          have been translated into another language.

     (bpo-1513695(53))

   * An optional ‘timeout’ parameter was added to the *note
     urllib.urlopen: 307. function and the ‘urllib.ftpwrapper’ class
     constructor, as well as the *note urllib2.urlopen: 307. function.
     The parameter specifies a timeout measured in seconds.  For
     example:

          >>> u = urllib2.urlopen("http://slow.example.com",
                                  timeout=3)
          Traceback (most recent call last):
            ...
          urllib2.URLError: <urlopen error timed out>
          >>>

     (Added by Facundo Batista.)

   * The Unicode database provided by the *note unicodedata: 10b. module
     has been updated to version 5.1.0.  (Updated by Martin von Löwis;
     bpo-3811(54).)

   * The *note warnings: 118. module’s ‘formatwarning()’ and
     ‘showwarning()’ gained an optional 'line' argument that can be used
     to supply the line of source code.  (Added as part of
     bpo-1631171(55), which re-implemented part of the *note warnings:
     118. module in C code.)

     A new function, ‘catch_warnings()’, is a context manager intended
     for testing purposes that lets you temporarily modify the warning
     filters and then restore their original values (bpo-3781(56)).

   * The XML-RPC *note SimpleXMLRPCServer: 135. and *note
     DocXMLRPCServer: 135. classes can now be prevented from immediately
     opening and binding to their socket by passing ‘False’ as the
     'bind_and_activate' constructor parameter.  This can be used to
     modify the instance’s ‘allow_reuse_address’ attribute before
     calling the ‘server_bind()’ and ‘server_activate()’ methods to open
     the socket and begin listening for connections.  (Contributed by
     Peter Parente; bpo-1599845(57).)

     ‘SimpleXMLRPCServer’ also has a ‘_send_traceback_header’ attribute;
     if true, the exception and formatted traceback are returned as HTTP
     headers «X-Exception» and «X-Traceback».  This feature is for
     debugging purposes only and should not be used on production
     servers because the tracebacks might reveal passwords or other
     sensitive information.  (Contributed by Alan McIntyre as part of
     his project for Google’s Summer of Code 2007.)

   * The *note xmlrpclib: 134. module no longer automatically converts
     *note datetime.date: 1fa. and *note datetime.time: 1fb. to the
     *note xmlrpclib.DateTime: 15ea. type; the conversion semantics were
     not necessarily correct for all applications.  Code using
     ‘xmlrpclib’ should convert ‘date’ and *note time: 1fb. instances.
     (bpo-1330538(58)) The code can also handle dates before 1900
     (contributed by Ralf Schmitt; bpo-2014(59)) and 64-bit integers
     represented by using ‘<i8>’ in XML-RPC responses (contributed by
     Riku Lindblad; bpo-2985(60)).

   * The *note zipfile: 137. module’s ‘ZipFile’ class now has
     ‘extract()’ and ‘extractall()’ methods that will unpack a single
     file or all the files in the archive to the current directory, or
     to a specified directory:

          z = zipfile.ZipFile('python-251.zip')

          # Unpack a single file, writing it relative
          # to the /tmp directory.
          z.extract('Python/sysmodule.c', '/tmp')

          # Unpack all the files in the archive.
          z.extractall()

     (Contributed by Alan McIntyre; bpo-467924(61).)

     The *note open(): 316, ‘read()’ and ‘extract()’ methods can now
     take either a filename or a ‘ZipInfo’ object.  This is useful when
     an archive accidentally contains a duplicated filename.
     (Contributed by Graham Horler; bpo-1775025(62).)

     Finally, *note zipfile: 137. now supports using Unicode filenames
     for archived files.  (Contributed by Alexey Borzenkov;
     bpo-1734346(63).)

* Menu:

* The ast module::
* The future_builtins module::
* The json module; JavaScript Object Notation: The json module JavaScript Object Notation.
* The plistlib module; A Property-List Parser: The plistlib module A Property-List Parser.
* ctypes Enhancements::
* Improved SSL Support::

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1736190

   (2) https://www.jcea.es/programacion/pybsddb.htm

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1817

   (4) https://bugs.python.org/issue?@action=redirect&bpo=600362

   (5) https://bugs.python.org/issue?@action=redirect&bpo=1381

   (6) https://bugs.python.org/issue?@action=redirect&bpo=1638033

   (7) https://bugs.python.org/issue?@action=redirect&bpo=1158

   (8) https://speleotrove.com/decimal/decarith.html

   (9) https://bugs.python.org/issue?@action=redirect&bpo=1221598

   (10) https://bugs.python.org/issue?@action=redirect&bpo=1739906

   (11) https://bugs.python.org/issue?@action=redirect&bpo=1001604

   (12) https://bugs.python.org/issue?@action=redirect&bpo=2138

   (13) https://bugs.python.org/issue?@action=redirect&bpo=2819

   (14) https://bugs.python.org/issue?@action=redirect&bpo=711019

   (15) https://bugs.python.org/issue?@action=redirect&bpo=1640

   (16) https://bugs.python.org/issue?@action=redirect&bpo=1663329

   (17) https://bugs.python.org/issue?@action=redirect&bpo=1181

   (18) https://bugs.python.org/issue?@action=redirect&bpo=1273829

   (19) https://bugs.python.org/issue?@action=redirect&bpo=1115886

   (20) https://bugs.python.org/issue?@action=redirect&bpo=1339796

   (21) https://bugs.python.org/issue?@action=redirect&bpo=957650

   (22) https://bugs.python.org/issue?@action=redirect&bpo=1393667

   (23) https://bugs.python.org/issue?@action=redirect&bpo=1106316

   (24) https://bugs.python.org/issue?@action=redirect&bpo=2439

   (25) https://bugs.python.org/issue?@action=redirect&bpo=1137

   (26) https://bugs.python.org/issue?@action=redirect&bpo=1727780

   (27) https://bugs.python.org/issue?@action=redirect&bpo=1681432

   (28) https://bugs.python.org/issue?@action=redirect&bpo=846388

   (29) https://bugs.python.org/issue?@action=redirect&bpo=3487

   (30) https://bugs.python.org/issue?@action=redirect&bpo=2250

   (31) https://bugs.python.org/issue?@action=redirect&bpo=1861

   (32) https://bugs.python.org/issue?@action=redirect&bpo=1657

   (33) https://bugs.python.org/issue?@action=redirect&bpo=2663

   (34) https://bugs.python.org/issue?@action=redirect&bpo=1583

   (35) https://bugs.python.org/issue?@action=redirect&bpo=2240

   (36) https://datatracker.ietf.org/doc/html/rfc2033.html

   (37) https://bugs.python.org/issue?@action=redirect&bpo=957003

   (38) https://datatracker.ietf.org/doc/html/rfc3207.html

   (39) https://bugs.python.org/issue?@action=redirect&bpo=829951

   (40) https://bugs.python.org/issue?@action=redirect&bpo=1646

   (41) https://bugs.python.org/issue?@action=redirect&bpo=742598

   (42) https://bugs.python.org/issue?@action=redirect&bpo=1193577

   (43) https://bugs.python.org/issue?@action=redirect&bpo=1534

   (44) https://bugs.python.org/issue?@action=redirect&bpo=2898

   (45) https://bugs.python.org/issue?@action=redirect&bpo=1648

   (46) https://bugs.python.org/issue?@action=redirect&bpo=1537850

   (47) https://bugs.python.org/issue?@action=redirect&bpo=2021

   (48) https://bugs.python.org/issue?@action=redirect&bpo=3781

   (49) https://bugs.python.org/issue?@action=redirect&bpo=1581073

   (50) https://bugs.python.org/issue?@action=redirect&bpo=2871

   (51) https://bugs.python.org/issue?@action=redirect&bpo=1533909

   (52) https://bugs.python.org/issue?@action=redirect&bpo=2906

   (53) https://bugs.python.org/issue?@action=redirect&bpo=1513695

   (54) https://bugs.python.org/issue?@action=redirect&bpo=3811

   (55) https://bugs.python.org/issue?@action=redirect&bpo=1631171

   (56) https://bugs.python.org/issue?@action=redirect&bpo=3781

   (57) https://bugs.python.org/issue?@action=redirect&bpo=1599845

   (58) https://bugs.python.org/issue?@action=redirect&bpo=1330538

   (59) https://bugs.python.org/issue?@action=redirect&bpo=2014

   (60) https://bugs.python.org/issue?@action=redirect&bpo=2985

   (61) https://bugs.python.org/issue?@action=redirect&bpo=467924

   (62) https://bugs.python.org/issue?@action=redirect&bpo=1775025

   (63) https://bugs.python.org/issue?@action=redirect&bpo=1734346


File: python.info,  Node: The ast module,  Next: The future_builtins module,  Up: New and Improved Modules<2>

1.17.18.1 The ‘ast’ module
..........................

The *note ast: 9. module provides an Abstract Syntax Tree representation
of Python code, and Armin Ronacher contributed a set of helper functions
that perform a variety of common tasks.  These will be useful for HTML
templating packages, code analyzers, and similar tools that process
Python code.

The ‘parse()’ function takes an expression and returns an AST. The
‘dump()’ function outputs a representation of a tree, suitable for
debugging:

     import ast

     t = ast.parse("""
     d = {}
     for i in 'abcdefghijklm':
         d[i + i] = ord(i) - ord('a') + 1
     print d
     """)
     print ast.dump(t)

This outputs a deeply nested tree:

     Module(body=[
       Assign(targets=[
         Name(id='d', ctx=Store())
        ], value=Dict(keys=[], values=[]))
       For(target=Name(id='i', ctx=Store()),
           iter=Str(s='abcdefghijklm'), body=[
         Assign(targets=[
           Subscript(value=
             Name(id='d', ctx=Load()),
               slice=
               Index(value=
                 BinOp(left=Name(id='i', ctx=Load()), op=Add(),
                  right=Name(id='i', ctx=Load()))), ctx=Store())
          ], value=
          BinOp(left=
           BinOp(left=
            Call(func=
             Name(id='ord', ctx=Load()), args=[
               Name(id='i', ctx=Load())
              ], keywords=[], starargs=None, kwargs=None),
            op=Sub(), right=Call(func=
             Name(id='ord', ctx=Load()), args=[
               Str(s='a')
              ], keywords=[], starargs=None, kwargs=None)),
            op=Add(), right=Num(n=1)))
         ], orelse=[])
        Print(dest=None, values=[
          Name(id='d', ctx=Load())
        ], nl=True)
      ])

The ‘literal_eval()’ method takes a string or an AST representing a
literal expression, parses and evaluates it, and returns the resulting
value.  A literal expression is a Python expression containing only
strings, numbers, dictionaries, etc.  but no statements or function
calls.  If you need to evaluate an expression but cannot accept the
security risk of using an *note eval(): 4a4. call, ‘literal_eval()’ will
handle it safely:

     >>> literal = '("a", "b", {2:4, 3:8, 1:2})'
     >>> print ast.literal_eval(literal)
     ('a', 'b', {1: 2, 2: 4, 3: 8})
     >>> print ast.literal_eval('"a" + "b"')
     Traceback (most recent call last):
       ...
     ValueError: malformed string

The module also includes ‘NodeVisitor’ and ‘NodeTransformer’ classes for
traversing and modifying an AST, and functions for common
transformations such as changing line numbers.


File: python.info,  Node: The future_builtins module,  Next: The json module JavaScript Object Notation,  Prev: The ast module,  Up: New and Improved Modules<2>

1.17.18.2 The ‘future_builtins’ module
......................................

Python 3.0 makes many changes to the repertoire of built-in functions,
and most of the changes can’t be introduced in the Python 2.x series
because they would break compatibility.  The ‘future_builtins’ module
provides versions of these built-in functions that can be imported when
writing 3.0-compatible code.

The functions in this module currently include:

   * ‘ascii(obj)’: equivalent to *note repr(): 1c1.  In Python 3.0,
     *note repr(): 1c1. will return a Unicode string, while *note
     ascii(): 15ed. will return a pure ASCII bytestring.

   * ‘filter(predicate, iterable)’, ‘map(func, iterable1, ...)’: the 3.0
     versions return iterators, unlike the 2.x builtins which return
     lists.

   * ‘hex(value)’, ‘oct(value)’: instead of calling the ‘__hex__()’ or
     ‘__oct__()’ methods, these versions will call the ‘__index__()’
     method and convert the result to hexadecimal or octal.  *note
     oct(): 14d6. will use the new ‘0o’ notation for its result.


File: python.info,  Node: The json module JavaScript Object Notation,  Next: The plistlib module A Property-List Parser,  Prev: The future_builtins module,  Up: New and Improved Modules<2>

1.17.18.3 The ‘json’ module: JavaScript Object Notation
.......................................................

The new *note json: 86. module supports the encoding and decoding of
Python types in JSON (Javascript Object Notation).  JSON is a
lightweight interchange format often used in web applications.  For more
information about JSON, see ‘http://www.json.org’.

*note json: 86. comes with support for decoding and encoding most
built-in Python types.  The following example encodes and decodes a
dictionary:

     >>> import json
     >>> data = {"spam": "foo", "parrot": 42}
     >>> in_json = json.dumps(data) # Encode the data
     >>> in_json
     '{"parrot": 42, "spam": "foo"}'
     >>> json.loads(in_json) # Decode into a Python object
     {"spam": "foo", "parrot": 42}

It’s also possible to write your own decoders and encoders to support
more types.  Pretty-printing of the JSON strings is also supported.

*note json: 86. (originally called simplejson) was written by Bob
Ippolito.


File: python.info,  Node: The plistlib module A Property-List Parser,  Next: ctypes Enhancements,  Prev: The json module JavaScript Object Notation,  Up: New and Improved Modules<2>

1.17.18.4 The ‘plistlib’ module: A Property-List Parser
.......................................................

The ‘.plist’ format is commonly used on Mac OS X to store basic data
types (numbers, strings, lists, and dictionaries) by serializing them
into an XML-based format.  It resembles the XML-RPC serialization of
data types.

Despite being primarily used on Mac OS X, the format has nothing
Mac-specific about it and the Python implementation works on any
platform that Python supports, so the *note plistlib: b0. module has
been promoted to the standard library.

Using the module is simple:

     import sys
     import plistlib
     import datetime

     # Create data structure
     data_struct = dict(lastAccessed=datetime.datetime.now(),
                        version=1,
                        categories=('Personal','Shared','Private'))

     # Create string containing XML.
     plist_str = plistlib.writePlistToString(data_struct)
     new_struct = plistlib.readPlistFromString(plist_str)
     print data_struct
     print new_struct

     # Write data structure to a file and read it back.
     plistlib.writePlist(data_struct, '/tmp/customizations.plist')
     new_struct = plistlib.readPlist('/tmp/customizations.plist')

     # read/writePlist accepts file-like objects as well as paths.
     plistlib.writePlist(data_struct, sys.stdout)


File: python.info,  Node: ctypes Enhancements,  Next: Improved SSL Support,  Prev: The plistlib module A Property-List Parser,  Up: New and Improved Modules<2>

1.17.18.5 ctypes Enhancements
.............................

Thomas Heller continued to maintain and enhance the *note ctypes: 2e.
module.

*note ctypes: 2e. now supports a ‘c_bool’ datatype that represents the
C99 ‘bool’ type.  (Contributed by David Remahl; bpo-1649190(1).)

The *note ctypes: 2e. string, buffer and array types have improved
support for extended slicing syntax, where various combinations of
‘(start, stop, step)’ are supplied.  (Implemented by Thomas Wouters.)

All *note ctypes: 2e. data types now support ‘from_buffer()’ and
‘from_buffer_copy()’ methods that create a ctypes instance based on a
provided buffer object.  ‘from_buffer_copy()’ copies the contents of the
object, while ‘from_buffer()’ will share the same memory area.

A new calling convention tells *note ctypes: 2e. to clear the ‘errno’ or
Win32 LastError variables at the outset of each wrapped call.
(Implemented by Thomas Heller; bpo-1798(2).)

You can now retrieve the Unix ‘errno’ variable after a function call.
When creating a wrapped function, you can supply ‘use_errno=True’ as a
keyword parameter to the ‘DLL()’ function and then call the module-level
methods ‘set_errno()’ and ‘get_errno()’ to set and retrieve the error
value.

The Win32 LastError variable is similarly supported by the ‘DLL()’,
‘OleDLL()’, and ‘WinDLL()’ functions.  You supply ‘use_last_error=True’
as a keyword parameter and then call the module-level methods
‘set_last_error()’ and ‘get_last_error()’.

The ‘byref()’ function, used to retrieve a pointer to a ctypes instance,
now has an optional 'offset' parameter that is a byte count that will be
added to the returned pointer.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1649190

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1798


File: python.info,  Node: Improved SSL Support,  Prev: ctypes Enhancements,  Up: New and Improved Modules<2>

1.17.18.6 Improved SSL Support
..............................

Bill Janssen made extensive improvements to Python 2.6’s support for the
Secure Sockets Layer by adding a new module, *note ssl: d5, that’s built
atop the OpenSSL(1) library.  This new module provides more control over
the protocol negotiated, the X.509 certificates used, and has better
support for writing SSL servers (as opposed to clients) in Python.  The
existing SSL support in the *note socket: d1. module hasn’t been removed
and continues to work, though it will be removed in Python 3.0.

To use the new module, you must first create a TCP connection in the
usual way and then pass it to the ‘ssl.wrap_socket()’ function.  It’s
possible to specify whether a certificate is required, and to obtain
certificate info by calling the ‘getpeercert()’ method.

Vedi anche
..........

The documentation for the *note ssl: d5. module.

   ---------- Footnotes ----------

   (1) https://www.openssl.org/


File: python.info,  Node: Deprecations and Removals,  Next: Build and C API Changes<9>,  Prev: New and Improved Modules<2>,  Up: What’s New in Python 2 6

1.17.19 Deprecations and Removals
---------------------------------

   * String exceptions have been removed.  Attempting to use them raises
     a *note TypeError: 198.

   * Changes to the *note Exception: bcf. interface as dictated by PEP
     352(1) continue to be made.  For 2.6, the ‘message’ attribute is
     being deprecated in favor of the *note args: 78e. attribute.

   * (3.0-warning mode) Python 3.0 will feature a reorganized standard
     library that will drop many outdated modules and rename others.
     Python 2.6 running in 3.0-warning mode will warn about these
     modules when they are imported.

     The list of deprecated modules is: ‘audiodev’, ‘bgenlocations’,
     ‘buildtools’, ‘bundlebuilder’, ‘Canvas’, ‘compiler’, ‘dircache’,
     ‘dl’, ‘fpformat’, ‘gensuitemodule’, ‘ihooks’, ‘imageop’, ‘imgfile’,
     ‘linuxaudiodev’, ‘mhlib’, ‘mimetools’, ‘multifile’, ‘new’, ‘pure’,
     ‘statvfs’, ‘sunaudiodev’, ‘test.testall’, and ‘toaiff’.

   * The ‘gopherlib’ module has been removed.

   * The ‘MimeWriter’ module and ‘mimify’ module have been deprecated;
     use the *note email: 3f. package instead.

   * The ‘md5’ module has been deprecated; use the *note hashlib: 6c.
     module instead.

   * The ‘posixfile’ module has been deprecated; *note fcntl.lockf():
     15f3. provides better locking.

   * The ‘popen2’ module has been deprecated; use the *note subprocess:
     dc. module.

   * The ‘rgbimg’ module has been removed.

   * The ‘sets’ module has been deprecated; it’s better to use the
     built-in *note set: 184. and *note frozenset: 7f3. types.

   * The ‘sha’ module has been deprecated; use the *note hashlib: 6c.
     module instead.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0352/


File: python.info,  Node: Build and C API Changes<9>,  Next: Porting to Python 2 6,  Prev: Deprecations and Removals,  Up: What’s New in Python 2 6

1.17.20 Build and C API Changes
-------------------------------

Changes to Python’s build process and to the C API include:

   * Python now must be compiled with C89 compilers (after 19 years!).
     This means that the Python source tree has dropped its own
     implementations of ‘memmove()’ and ‘strerror()’, which are in the
     C89 standard library.

   * Python 2.6 can be built with Microsoft Visual Studio 2008 (version
     9.0), and this is the new default compiler.  See the ‘PCbuild’
     directory for the build files.  (Implemented by Christian Heimes.)

   * On Mac OS X, Python 2.6 can be compiled as a 4-way universal build.
     The ‘configure’ script can take a
     ‘--with-universal-archs=[32-bit|64-bit|all]’ switch, controlling
     whether the binaries are built for 32-bit architectures (x86,
     PowerPC), 64-bit (x86-64 and PPC-64), or both.  (Contributed by
     Ronald Oussoren.)

   * A new function added in Python 2.6.6, ‘PySys_SetArgvEx()’, sets the
     value of ‘sys.argv’ and can optionally update ‘sys.path’ to include
     the directory containing the script named by ‘sys.argv[0]’
     depending on the value of an 'updatepath' parameter.

     This function was added to close a security hole for applications
     that embed Python.  The old function, ‘PySys_SetArgv()’, would
     always update ‘sys.path’, and sometimes it would add the current
     directory.  This meant that, if you ran an application embedding
     Python in a directory controlled by someone else, attackers could
     put a Trojan-horse module in the directory (say, a file named
     ‘os.py’) that your application would then import and run.

     If you maintain a C/C++ application that embeds Python, check
     whether you’re calling ‘PySys_SetArgv()’ and carefully consider
     whether the application should be using ‘PySys_SetArgvEx()’ with
     'updatepath' set to false.  Note that using this function will
     break compatibility with Python versions 2.6.5 and earlier; if you
     have to continue working with earlier versions, you can leave the
     call to ‘PySys_SetArgv()’ alone and call
     ‘PyRun_SimpleString("sys.path.pop(0)\n")’ afterwards to discard the
     first ‘sys.path’ component.

     Security issue reported as CVE 2008-5983(1); discussed in
     gh-50003(2), and fixed by Antoine Pitrou.

   * The BerkeleyDB module now has a C API object, available as
     ‘bsddb.db.api’.  This object can be used by other C extensions that
     wish to use the ‘bsddb’ module for their own purposes.
     (Contributed by Duncan Grisby.)

   * The new buffer interface, previously described in *note the PEP
     3118 section: 15bc, adds *note PyObject_GetBuffer(): 63a. and *note
     PyBuffer_Release(): 63b, as well as a few other functions.

   * Python’s use of the C stdio library is now thread-safe, or at least
     as thread-safe as the underlying library is.  A long-standing
     potential bug occurred if one thread closed a file object while
     another thread was reading from or writing to the object.  In 2.6
     file objects have a reference count, manipulated by the
     ‘PyFile_IncUseCount()’ and ‘PyFile_DecUseCount()’ functions.  File
     objects can’t be closed unless the reference count is zero.
     ‘PyFile_IncUseCount()’ should be called while the GIL is still
     held, before carrying out an I/O operation using the ‘FILE *’
     pointer, and ‘PyFile_DecUseCount()’ should be called immediately
     after the GIL is re-acquired.  (Contributed by Antoine Pitrou and
     Gregory P. Smith.)

   * Importing modules simultaneously in two different threads no longer
     deadlocks; it will now raise an *note ImportError: 65b.  A new API
     function, *note PyImport_ImportModuleNoBlock(): 3db, will look for
     a module in ‘sys.modules’ first, then try to import it after
     acquiring an import lock.  If the import lock is held by another
     thread, an *note ImportError: 65b. is raised.  (Contributed by
     Christian Heimes.)

   * Several functions return information about the platform’s
     floating-point support.  *note PyFloat_GetMax(): 15f5. returns the
     maximum representable floating-point value, and *note
     PyFloat_GetMin(): 15f6. returns the minimum positive value.  *note
     PyFloat_GetInfo(): 15f7. returns an object containing more
     information from the ‘float.h’ file, such as ‘"mant_dig"’ (number
     of digits in the mantissa), ‘"epsilon"’ (smallest difference
     between 1.0 and the next largest value representable), and several
     others.  (Contributed by Christian Heimes; bpo-1534(3).)

   * C functions and methods that use *note PyComplex_AsCComplex():
     15f8. will now accept arguments that have a ‘__complex__()’ method.
     In particular, the functions in the *note cmath: 19. module will
     now accept objects with this method.  This is a backport of a
     Python 3.0 change.  (Contributed by Mark Dickinson;
     bpo-1675423(4).)

   * Python’s C API now includes two functions for case-insensitive
     string comparisons, ‘PyOS_stricmp(char*, char*)’ and
     ‘PyOS_strnicmp(char*, char*, Py_ssize_t)’.  (Contributed by
     Christian Heimes; bpo-1635(5).)

   * Many C extensions define their own little macro for adding integers
     and strings to the module’s dictionary in the ‘init*’ function.
     Python 2.6 finally defines standard macros for adding values to a
     module, *note PyModule_AddStringMacro: 15f9. and *note
     PyModule_AddIntMacro(): 15fa.  (Contributed by Christian Heimes.)

   * Some macros were renamed in both 3.0 and 2.6 to make it clearer
     that they are macros, not functions.  ‘Py_Size()’ became *note
     Py_SIZE(): 986, ‘Py_Type()’ became *note Py_TYPE(): 3c9, and
     ‘Py_Refcnt()’ became *note Py_REFCNT(): 2cf.  The mixed-case macros
     are still available in Python 2.6 for backward compatibility.
     (bpo-1629(6))

   * Distutils now places C extensions it builds in a different
     directory when running on a debug version of Python.  (Contributed
     by Collin Winter; bpo-1530959(7).)

   * Several basic data types, such as integers and strings, maintain
     internal free lists of objects that can be re-used.  The data
     structures for these free lists now follow a naming convention: the
     variable is always named ‘free_list’, the counter is always named
     ‘numfree’, and a macro ‘Py<typename>_MAXFREELIST’ is always
     defined.

   * A new Makefile target, «make patchcheck», prepares the Python
     source tree for making a patch: it fixes trailing whitespace in all
     modified ‘.py’ files, checks whether the documentation has been
     changed, and reports whether the ‘Misc/ACKS’ and ‘Misc/NEWS’ files
     have been updated.  (Contributed by Brett Cannon.)

     Another new target, «make profile-opt», compiles a Python binary
     using GCC’s profile-guided optimization.  It compiles Python with
     profiling enabled, runs the test suite to obtain a set of profiling
     results, and then compiles using these results for optimization.
     (Contributed by Gregory P. Smith.)

* Menu:

* Port-Specific Changes; Windows: Port-Specific Changes Windows<2>.
* Port-Specific Changes; Mac OS X: Port-Specific Changes Mac OS X<2>.
* Port-Specific Changes; IRIX: Port-Specific Changes IRIX.

   ---------- Footnotes ----------

   (1) https://www.cve.org/CVERecord?id=CVE-2008-5983

   (2) https://github.com/python/cpython/issues/50003

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1534

   (4) https://bugs.python.org/issue?@action=redirect&bpo=1675423

   (5) https://bugs.python.org/issue?@action=redirect&bpo=1635

   (6) https://bugs.python.org/issue?@action=redirect&bpo=1629

   (7) https://bugs.python.org/issue?@action=redirect&bpo=1530959


File: python.info,  Node: Port-Specific Changes Windows<2>,  Next: Port-Specific Changes Mac OS X<2>,  Up: Build and C API Changes<9>

1.17.20.1 Port-Specific Changes: Windows
........................................

   * The support for Windows 95, 98, ME and NT4 has been dropped.
     Python 2.6 requires at least Windows 2000 SP4.

   * The new default compiler on Windows is Visual Studio 2008 (version
     9.0).  The build directories for Visual Studio 2003 (version 7.1)
     and 2005 (version 8.0) were moved into the PC/ directory.  The new
     ‘PCbuild’ directory supports cross compilation for X64, debug
     builds and Profile Guided Optimization (PGO). PGO builds are
     roughly 10% faster than normal builds.  (Contributed by Christian
     Heimes with help from Amaury Forgeot d’Arc and Martin von Löwis.)

   * The *note msvcrt: 97. module now supports both the normal and wide
     char variants of the console I/O API. The *note getwch(): 15fc.
     function reads a keypress and returns a Unicode value, as does the
     *note getwche(): 15fd. function.  The *note putwch(): 15fe.
     function takes a Unicode character and writes it to the console.
     (Contributed by Christian Heimes.)

   * *note os.path.expandvars(): 15e0. will now expand environment
     variables in the form «%var%», and «~user» will be expanded into
     the user’s home directory path.  (Contributed by Josiah Carlson;
     bpo-957650(1).)

   * The *note socket: d1. module’s socket objects now have an *note
     ioctl(): ed0. method that provides a limited interface to the
     ‘WSAIoctl()’ system interface.

   * The *note _winreg: 11c. module now has a function, *note
     ExpandEnvironmentStrings(): 15ff, that expands environment variable
     references such as ‘%NAME%’ in an input string.  The handle objects
     provided by this module now support the context protocol, so they
     can be used in *note with: 186. statements.  (Contributed by
     Christian Heimes.)

     *note _winreg: 11c. also has better support for x64 systems,
     exposing the *note DisableReflectionKey(): 156c, *note
     EnableReflectionKey(): 156d, and *note QueryReflectionKey(): 156e.
     functions, which enable and disable registry reflection for 32-bit
     processes running on 64-bit systems.  (bpo-1753245(2))

   * The ‘msilib’ module’s ‘Record’ object gained ‘GetInteger()’ and
     ‘GetString()’ methods that return field values as an integer or a
     string.  (Contributed by Floris Bruynooghe; bpo-2125(3).)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=957650

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1753245

   (3) https://bugs.python.org/issue?@action=redirect&bpo=2125


File: python.info,  Node: Port-Specific Changes Mac OS X<2>,  Next: Port-Specific Changes IRIX,  Prev: Port-Specific Changes Windows<2>,  Up: Build and C API Changes<9>

1.17.20.2 Port-Specific Changes: Mac OS X
.........................................

   * When compiling a framework build of Python, you can now specify the
     framework name to be used by providing the ‘--with-framework-name=’
     option to the ‘configure’ script.

   * The ‘macfs’ module has been removed.  This in turn required the
     ‘macostools.touched()’ function to be removed because it depended
     on the ‘macfs’ module.  (bpo-1490190(1))

   * Many other Mac OS modules have been deprecated and will be removed
     in Python 3.0: ‘_builtinSuites’, ‘aepack’, ‘aetools’, ‘aetypes’,
     ‘applesingle’, ‘appletrawmain’, ‘appletrunner’, ‘argvemulator’,
     ‘Audio_mac’, ‘autoGIL’, ‘Carbon’, ‘cfmfile’, ‘CodeWarrior’,
     ‘ColorPicker’, ‘EasyDialogs’, ‘Explorer’, ‘Finder’, ‘FrameWork’,
     ‘findertools’, ‘ic’, ‘icglue’, ‘icopen’, ‘macerrors’, ‘MacOS’,
     ‘macfs’, ‘macostools’, ‘macresource’, ‘MiniAEFrame’, ‘Nav’,
     ‘Netscape’, ‘OSATerminology’, ‘pimp’, ‘PixMapWrapper’, ‘StdSuites’,
     ‘SystemEvents’, ‘Terminal’, and ‘terminalcommand’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1490190


File: python.info,  Node: Port-Specific Changes IRIX,  Prev: Port-Specific Changes Mac OS X<2>,  Up: Build and C API Changes<9>

1.17.20.3 Port-Specific Changes: IRIX
.....................................

A number of old IRIX-specific modules were deprecated and will be
removed in Python 3.0: ‘al’ and ‘AL’, ‘cd’, ‘cddb’, ‘cdplayer’, ‘CL’ and
‘cl’, ‘DEVICE’, ‘ERRNO’, ‘FILE’, ‘FL’ and ‘fl’, ‘flp’, ‘fm’, ‘GET’,
‘GLWS’, ‘GL’ and ‘gl’, ‘IN’, ‘IOCTL’, ‘jpeg’, ‘panelparser’, ‘readcd’,
‘SV’ and ‘sv’, ‘torgb’, ‘videoreader’, and ‘WAIT’.


File: python.info,  Node: Porting to Python 2 6,  Next: Acknowledgements<2>,  Prev: Build and C API Changes<9>,  Up: What’s New in Python 2 6

1.17.21 Porting to Python 2.6
-----------------------------

This section lists previously described changes and other bugfixes that
may require changes to your code:

   * Classes that aren’t supposed to be hashable should set ‘__hash__ =
     None’ in their definitions to indicate the fact.

   * String exceptions have been removed.  Attempting to use them raises
     a *note TypeError: 198.

   * The ‘__init__()’ method of *note collections.deque: 7f5. now clears
     any existing contents of the deque before adding elements from the
     iterable.  This change makes the behavior match ‘list.__init__()’.

   * *note object.__init__(): 8c0. previously accepted arbitrary
     arguments and keyword arguments, ignoring them.  In Python 2.6,
     this is no longer allowed and will result in a *note TypeError:
     198.  This will affect ‘__init__()’ methods that end up calling the
     corresponding method on *note object: c80. (perhaps through using
     *note super(): 1a6.).  See bpo-1683368(1) for discussion.

   * The ‘Decimal’ constructor now accepts leading and trailing
     whitespace when passed a string.  Previously it would raise an
     ‘InvalidOperation’ exception.  On the other hand, the
     ‘create_decimal()’ method of ‘Context’ objects now explicitly
     disallows extra whitespace, raising a ‘ConversionSyntax’ exception.

   * Due to an implementation accident, if you passed a file path to the
     built-in *note __import__(): ad3. function, it would actually
     import the specified file.  This was never intended to work,
     however, and the implementation now explicitly checks for this case
     and raises an *note ImportError: 65b.

   * C API: the *note PyImport_Import(): 1603. and *note
     PyImport_ImportModule(): 3dc. functions now default to absolute
     imports, not relative imports.  This will affect C extensions that
     import other modules.

   * C API: extension data types that shouldn’t be hashable should
     define their ‘tp_hash’ slot to *note PyObject_HashNotImplemented():
     15ce.

   * The *note socket: d1. module exception *note socket.error: 1258.
     now inherits from *note IOError: 1255.  Previously it wasn’t a
     subclass of ‘StandardError’ but now it is, through *note IOError:
     1255.  (Implemented by Gregory P. Smith; bpo-1706815(2).)

   * The *note xmlrpclib: 134. module no longer automatically converts
     *note datetime.date: 1fa. and *note datetime.time: 1fb. to the
     *note xmlrpclib.DateTime: 15ea. type; the conversion semantics were
     not necessarily correct for all applications.  Code using
     ‘xmlrpclib’ should convert ‘date’ and *note time: 1fb. instances.
     (bpo-1330538(3))

   * (3.0-warning mode) The *note Exception: bcf. class now warns when
     accessed using slicing or index access; having *note Exception:
     bcf. behave like a tuple is being phased out.

   * (3.0-warning mode) inequality comparisons between two dictionaries
     or two objects that don’t implement comparison methods are reported
     as warnings.  ‘dict1 == dict2’ still works, but ‘dict1 < dict2’ is
     being phased out.

     Comparisons between cells, which are an implementation detail of
     Python’s scoping rules, also cause warnings because such
     comparisons are forbidden entirely in 3.0.

For applications that embed Python:

   * The ‘PySys_SetArgvEx()’ function was added in Python 2.6.6, letting
     applications close a security hole when the existing
     ‘PySys_SetArgv()’ function was used.  Check whether you’re calling
     ‘PySys_SetArgv()’ and carefully consider whether the application
     should be using ‘PySys_SetArgvEx()’ with 'updatepath' set to false.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1683368

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1706815

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1330538


File: python.info,  Node: Acknowledgements<2>,  Prev: Porting to Python 2 6,  Up: What’s New in Python 2 6

1.17.22 Acknowledgements
------------------------

The author would like to thank the following people for offering
suggestions, corrections and assistance with various drafts of this
article: Georg Brandl, Steve Brown, Nick Coghlan, Ralph Corderoy, Jim
Jewett, Kent Johnson, Chris Lambacher, Martin Michlmayr, Antoine Pitrou,
Brian Warner.


File: python.info,  Node: What’s New in Python 2 5,  Next: What’s New in Python 2 4,  Prev: What’s New in Python 2 6,  Up: Novità in Python

1.18 What’s New in Python 2.5
=============================


Author: A.M. Kuchling

This article explains the new features in Python 2.5.  The final release
of Python 2.5 is scheduled for August 2006; PEP 356(1) describes the
planned release schedule.  Python 2.5 was released on September 19,
2006.

The changes in Python 2.5 are an interesting mix of language and library
improvements.  The library enhancements will be more important to
Python’s user community, I think, because several widely useful packages
were added.  New modules include ElementTree for XML processing
(‘xml.etree’), the SQLite database module (‘sqlite’), and the *note
ctypes: 2e. module for calling C functions.

The language changes are of middling significance.  Some pleasant new
features were added, but most of them aren’t features that you’ll use
every day.  Conditional expressions were finally added to the language
using a novel syntax; see section *note PEP 308; Conditional
Expressions: 1609.  The new “*note with: 186.” statement will make
writing cleanup code easier (section *note PEP 343; The “with”
statement: 160a.).  Values can now be passed into generators (section
*note PEP 342; New Generator Features: 160b.).  Imports are now visible
as either absolute or relative (section *note PEP 328; Absolute and
Relative Imports: 160c.).  Some corner cases of exception handling are
handled better (section *note PEP 341; Unified try/except/finally:
160d.).  All these improvements are worthwhile, but they’re improvements
to one specific language feature or another; none of them are broad
modifications to Python’s semantics.

As well as the language and library additions, other improvements and
bugfixes were made throughout the source tree.  A search through the SVN
change logs finds there were 353 patches applied and 458 bugs fixed
between Python 2.4 and 2.5.  (Both figures are likely to be
underestimates.)

This article doesn’t try to be a complete specification of the new
features; instead changes are briefly introduced using helpful examples.
For full details, you should always refer to the documentation for
Python 2.5 at ‘https://docs.python.org’.  If you want to understand the
complete implementation and design rationale, refer to the PEP for a
particular new feature.

Comments, suggestions, and error reports for this document are welcome;
please e-mail them to the author or open a bug in the Python bug
tracker.

* Menu:

* PEP 308; Conditional Expressions: PEP 308 Conditional Expressions.
* PEP 309; Partial Function Application: PEP 309 Partial Function Application.
* PEP 314; Metadata for Python Software Packages v1.1: PEP 314 Metadata for Python Software Packages v1 1.
* PEP 328; Absolute and Relative Imports: PEP 328 Absolute and Relative Imports.
* PEP 338; Executing Modules as Scripts: PEP 338 Executing Modules as Scripts.
* PEP 341; Unified try/except/finally: PEP 341 Unified try/except/finally.
* PEP 342; New Generator Features: PEP 342 New Generator Features.
* PEP 343; The “with” statement: PEP 343 The “with” statement<2>.
* PEP 352; Exceptions as New-Style Classes: PEP 352 Exceptions as New-Style Classes.
* PEP 353; Using ssize_t as the index type: PEP 353 Using ssize_t as the index type.
* PEP 357; The “__index__” method: PEP 357 The “__index__” method.
* Other Language Changes: Other Language Changes<15>.
* New, Improved, and Removed Modules: New Improved and Removed Modules.
* Build and C API Changes: Build and C API Changes<10>.
* Porting to Python 2.5: Porting to Python 2 5.
* Acknowledgements: Acknowledgements<3>.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0356/


File: python.info,  Node: PEP 308 Conditional Expressions,  Next: PEP 309 Partial Function Application,  Up: What’s New in Python 2 5

1.18.1 PEP 308: Conditional Expressions
---------------------------------------

For a long time, people have been requesting a way to write conditional
expressions, which are expressions that return value A or value B
depending on whether a Boolean value is true or false.  A conditional
expression lets you write a single assignment statement that has the
same effect as the following:

     if condition:
         x = true_value
     else:
         x = false_value

There have been endless tedious discussions of syntax on both python-dev
and comp.lang.python.  A vote was even held that found the majority of
voters wanted conditional expressions in some form, but there was no
syntax that was preferred by a clear majority.  Candidates included C’s
‘cond ? true_v : false_v’, ‘if cond then true_v else false_v’, and 16
other variations.

Guido van Rossum eventually chose a surprising syntax:

     x = true_value if condition else false_value

Evaluation is still lazy as in existing Boolean expressions, so the
order of evaluation jumps around a bit.  The 'condition' expression in
the middle is evaluated first, and the 'true_value' expression is
evaluated only if the condition was true.  Similarly, the 'false_value'
expression is only evaluated when the condition is false.

This syntax may seem strange and backwards; why does the condition go in
the 'middle' of the expression, and not in the front as in C’s ‘c ? x :
y’?  The decision was checked by applying the new syntax to the modules
in the standard library and seeing how the resulting code read.  In many
cases where a conditional expression is used, one value seems to be the
“common case” and one value is an “exceptional case”, used only on rarer
occasions when the condition isn’t met.  The conditional syntax makes
this pattern a bit more obvious:

     contents = ((doc + '\n') if doc else '')

I read the above statement as meaning «here 'contents' is usually
assigned a value of ‘doc+'\n'’; sometimes 'doc' is empty, in which
special case an empty string is returned.» I doubt I will use
conditional expressions very often where there isn’t a clear common and
uncommon case.

There was some discussion of whether the language should require
surrounding conditional expressions with parentheses.  The decision was
made to 'not' require parentheses in the Python language’s grammar, but
as a matter of style I think you should always use them.  Consider these
two statements:

     # First version -- no parens
     level = 1 if logging else 0

     # Second version -- with parens
     level = (1 if logging else 0)

In the first version, I think a reader’s eye might group the statement
into “level = 1”, “if logging”, “else 0”, and think that the condition
decides whether the assignment to 'level' is performed.  The second
version reads better, in my opinion, because it makes it clear that the
assignment is always performed and the choice is being made between two
values.

Another reason for including the brackets: a few odd combinations of
list comprehensions and lambdas could look like incorrect conditional
expressions.  See PEP 308(1) for some examples.  If you put parentheses
around your conditional expressions, you won’t run into this case.

Vedi anche
..........

PEP 308(2) - Conditional Expressions

     PEP written by Guido van Rossum and Raymond D. Hettinger;
     implemented by Thomas Wouters.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0308/

   (2) https://peps.python.org/pep-0308/


File: python.info,  Node: PEP 309 Partial Function Application,  Next: PEP 314 Metadata for Python Software Packages v1 1,  Prev: PEP 308 Conditional Expressions,  Up: What’s New in Python 2 5

1.18.2 PEP 309: Partial Function Application
--------------------------------------------

The *note functools: 63. module is intended to contain tools for
functional-style programming.

One useful tool in this module is the ‘partial()’ function.  For
programs written in a functional style, you’ll sometimes want to
construct variants of existing functions that have some of the
parameters filled in.  Consider a Python function ‘f(a, b, c)’; you
could create a new function ‘g(b, c)’ that was equivalent to ‘f(1, b,
c)’.  This is called «partial function application».

‘partial()’ takes the arguments ‘(function, arg1, arg2, ...
kwarg1=value1, kwarg2=value2)’.  The resulting object is callable, so
you can just call it to invoke 'function' with the filled-in arguments.

Here’s a small but realistic example:

     import functools

     def log (message, subsystem):
         "Write the contents of 'message' to the specified subsystem."
         print '%s: %s' % (subsystem, message)
         ...

     server_log = functools.partial(log, subsystem='server')
     server_log('Unable to open socket')

Here’s another example, from a program that uses PyGTK. Here a
context-sensitive pop-up menu is being constructed dynamically.  The
callback provided for the menu option is a partially applied version of
the ‘open_item()’ method, where the first argument has been provided.

     ...
     class Application:
         def open_item(self, path):
            ...
         def init (self):
             open_func = functools.partial(self.open_item, item_path)
             popup_menu.append( ("Open", open_func, 1) )

Another function in the *note functools: 63. module is the
‘update_wrapper(wrapper, wrapped)’ function that helps you write
well-behaved decorators.  ‘update_wrapper()’ copies the name, module,
and docstring attribute to a wrapper function so that tracebacks inside
the wrapped function are easier to understand.  For example, you might
write:

     def my_decorator(f):
         def wrapper(*args, **kwds):
             print 'Calling decorated function'
             return f(*args, **kwds)
         functools.update_wrapper(wrapper, f)
         return wrapper

‘wraps()’ is a decorator that can be used inside your own decorators to
copy the wrapped function’s information.  An alternate version of the
previous example would be:

     def my_decorator(f):
         @functools.wraps(f)
         def wrapper(*args, **kwds):
             print 'Calling decorated function'
             return f(*args, **kwds)
         return wrapper

Vedi anche
..........

PEP 309(1) - Partial Function Application

     PEP proposed and written by Peter Harris; implemented by Hye-Shik
     Chang and Nick Coghlan, with adaptations by Raymond Hettinger.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0309/


File: python.info,  Node: PEP 314 Metadata for Python Software Packages v1 1,  Next: PEP 328 Absolute and Relative Imports,  Prev: PEP 309 Partial Function Application,  Up: What’s New in Python 2 5

1.18.3 PEP 314: Metadata for Python Software Packages v1.1
----------------------------------------------------------

Some simple dependency support was added to Distutils.  The ‘setup()’
function now has ‘requires’, ‘provides’, and ‘obsoletes’ keyword
parameters.  When you build a source distribution using the ‘sdist’
command, the dependency information will be recorded in the ‘PKG-INFO’
file.

Another new keyword parameter is ‘download_url’, which should be set to
a URL for the package’s source code.  This means it’s now possible to
look up an entry in the package index, determine the dependencies for a
package, and download the required packages.

     VERSION = '1.0'
     setup(name='PyPackage',
           version=VERSION,
           requires=['numarray', 'zlib (>=1.1.4)'],
           obsoletes=['OldPackage']
           download_url=('http://www.example.com/pypackage/dist/pkg-%s.tar.gz'
                         % VERSION),
          )

Another new enhancement to the Python package index at
‘https://pypi.org’ is storing source and binary archives for a package.
The new ‘upload’ Distutils command will upload a package to the
repository.

Before a package can be uploaded, you must be able to build a
distribution using the ‘sdist’ Distutils command.  Once that works, you
can run ‘python setup.py upload’ to add your package to the PyPI
archive.  Optionally you can GPG-sign the package by supplying the
‘--sign’ and ‘--identity’ options.

Package uploading was implemented by Martin von Löwis and Richard Jones.

Vedi anche
..........

PEP 314(1) - Metadata for Python Software Packages v1.1

     PEP proposed and written by A.M. Kuchling, Richard Jones, and Fred
     Drake; implemented by Richard Jones and Fred Drake.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0314/


File: python.info,  Node: PEP 328 Absolute and Relative Imports,  Next: PEP 338 Executing Modules as Scripts,  Prev: PEP 314 Metadata for Python Software Packages v1 1,  Up: What’s New in Python 2 5

1.18.4 PEP 328: Absolute and Relative Imports
---------------------------------------------

The simpler part of PEP 328(1) was implemented in Python 2.4:
parentheses could now be used to enclose the names imported from a
module using the ‘from ... import ...’ statement, making it easier to
import many different names.

The more complicated part has been implemented in Python 2.5: importing
a module can be specified to use absolute or package-relative imports.
The plan is to move toward making absolute imports the default in future
versions of Python.

Let’s say you have a package directory like this:

     pkg/
     pkg/__init__.py
     pkg/main.py
     pkg/string.py

This defines a package named ‘pkg’ containing the ‘pkg.main’ and
‘pkg.string’ submodules.

Consider the code in the ‘main.py’ module.  What happens if it executes
the statement ‘import string’?  In Python 2.4 and earlier, it will first
look in the package’s directory to perform a relative import, finds
‘pkg/string.py’, imports the contents of that file as the ‘pkg.string’
module, and that module is bound to the name ‘string’ in the ‘pkg.main’
module’s namespace.

That’s fine if ‘pkg.string’ was what you wanted.  But what if you wanted
Python’s standard *note string: d8. module?  There’s no clean way to
ignore ‘pkg.string’ and look for the standard module; generally you had
to look at the contents of ‘sys.modules’, which is slightly unclean.
Holger Krekel’s ‘py.std’ package provides a tidier way to perform
imports from the standard library, ‘import py; py.std.string.join()’,
but that package isn’t available on all Python installations.

Reading code which relies on relative imports is also less clear,
because a reader may be confused about which module, *note string: d8.
or ‘pkg.string’, is intended to be used.  Python users soon learned not
to duplicate the names of standard library modules in the names of their
packages” submodules, but you can’t protect against having your
submodule’s name being used for a new module added in a future version
of Python.

In Python 2.5, you can switch *note import: 7f9.’s behaviour to absolute
imports using a ‘from __future__ import absolute_import’ directive.
This absolute-import behaviour will become the default in a future
version (probably Python 2.7).  Once absolute imports are the default,
‘import string’ will always find the standard library’s version.  It’s
suggested that users should begin using absolute imports as much as
possible, so it’s preferable to begin writing ‘from pkg import string’
in your code.

Relative imports are still possible by adding a leading period to the
module name when using the ‘from ... import’ form:

     # Import names from pkg.string
     from .string import name1, name2
     # Import pkg.string
     from . import string

This imports the *note string: d8. module relative to the current
package, so in ‘pkg.main’ this will import 'name1' and 'name2' from
‘pkg.string’.  Additional leading periods perform the relative import
starting from the parent of the current package.  For example, code in
the ‘A.B.C’ module can do:

     from . import D                 # Imports A.B.D
     from .. import E                # Imports A.E
     from ..F import G               # Imports A.F.G

Leading periods cannot be used with the ‘import modname’ form of the
import statement, only the ‘from ... import’ form.

Vedi anche
..........

PEP 328(2) - Imports: Multi-Line and Absolute/Relative

     PEP written by Aahz; implemented by Thomas Wouters.

‘https://pylib.readthedocs.io/’

     The py library by Holger Krekel, which contains the ‘py.std’
     package.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0328/

   (2) https://peps.python.org/pep-0328/


File: python.info,  Node: PEP 338 Executing Modules as Scripts,  Next: PEP 341 Unified try/except/finally,  Prev: PEP 328 Absolute and Relative Imports,  Up: What’s New in Python 2 5

1.18.5 PEP 338: Executing Modules as Scripts
--------------------------------------------

The *note -m: 23c. switch added in Python 2.4 to execute a module as a
script gained a few more abilities.  Instead of being implemented in C
code inside the Python interpreter, the switch now uses an
implementation in a new module, *note runpy: c3.

The *note runpy: c3. module implements a more sophisticated import
mechanism so that it’s now possible to run modules in a package such as
‘pychecker.checker’.  The module also supports alternative import
mechanisms such as the *note zipimport: 138. module.  This means you can
add a .zip archive’s path to ‘sys.path’ and then use the *note -m: 23c.
switch to execute code from the archive.

Vedi anche
..........

PEP 338(1) - Executing modules as scripts

     PEP written and implemented by Nick Coghlan.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0338/


File: python.info,  Node: PEP 341 Unified try/except/finally,  Next: PEP 342 New Generator Features,  Prev: PEP 338 Executing Modules as Scripts,  Up: What’s New in Python 2 5

1.18.6 PEP 341: Unified try/except/finally
------------------------------------------

Until Python 2.5, the *note try: 8f9. statement came in two flavours.
You could use a *note finally: 1b0. block to ensure that code is always
executed, or one or more *note except: 1ab. blocks to catch specific
exceptions.  You couldn’t combine both ‘except’ blocks and a ‘finally’
block, because generating the right bytecode for the combined version
was complicated and it wasn’t clear what the semantics of the combined
statement should be.

Guido van Rossum spent some time working with Java, which does support
the equivalent of combining *note except: 1ab. blocks and a *note
finally: 1b0. block, and this clarified what the statement should mean.
In Python 2.5, you can now write:

     try:
         block-1 ...
     except Exception1:
         handler-1 ...
     except Exception2:
         handler-2 ...
     else:
         else-block
     finally:
         final-block

The code in 'block-1' is executed.  If the code raises an exception, the
various *note except: 1ab. blocks are tested: if the exception is of
class ‘Exception1’, 'handler-1' is executed; otherwise if it’s of class
‘Exception2’, 'handler-2' is executed, and so forth.  If no exception is
raised, the 'else-block' is executed.

No matter what happened previously, the 'final-block' is executed once
the code block is complete and any raised exceptions handled.  Even if
there’s an error in an exception handler or the 'else-block' and a new
exception is raised, the code in the 'final-block' is still run.

Vedi anche
..........

PEP 341(1) - Unifying try-except and try-finally

     PEP written by Georg Brandl; implementation by Thomas Lee.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0341/


File: python.info,  Node: PEP 342 New Generator Features,  Next: PEP 343 The “with” statement<2>,  Prev: PEP 341 Unified try/except/finally,  Up: What’s New in Python 2 5

1.18.7 PEP 342: New Generator Features
--------------------------------------

Python 2.5 adds a simple way to pass values 'into' a generator.  As
introduced in Python 2.3, generators only produce output; once a
generator’s code was invoked to create an iterator, there was no way to
pass any new information into the function when its execution is
resumed.  Sometimes the ability to pass in some information would be
useful.  Hackish solutions to this include making the generator’s code
look at a global variable and then changing the global variable’s value,
or passing in some mutable object that callers then modify.

To refresh your memory of basic generators, here’s a simple example:

     def counter (maximum):
         i = 0
         while i < maximum:
             yield i
             i += 1

When you call ‘counter(10)’, the result is an iterator that returns the
values from 0 up to 9.  On encountering the *note yield: bc4. statement,
the iterator returns the provided value and suspends the function’s
execution, preserving the local variables.  Execution resumes on the
following call to the iterator’s *note next(): 9da. method, picking up
after the ‘yield’ statement.

In Python 2.3, *note yield: bc4. was a statement; it didn’t return any
value.  In 2.5, ‘yield’ is now an expression, returning a value that can
be assigned to a variable or otherwise operated on:

     val = (yield i)

I recommend that you always put parentheses around a *note yield: bc4.
expression when you’re doing something with the returned value, as in
the above example.  The parentheses aren’t always necessary, but it’s
easier to always add them instead of having to remember when they’re
needed.

( PEP 342(1) explains the exact rules, which are that a *note yield:
bc4.-expression must always be parenthesized except when it occurs at
the top-level expression on the right-hand side of an assignment.  This
means you can write ‘val = yield i’ but have to use parentheses when
there’s an operation, as in ‘val = (yield i) + 12’.)

Values are sent into a generator by calling its ‘send(value)’ method.
The generator’s code is then resumed and the *note yield: bc4.
expression returns the specified 'value'.  If the regular *note next():
9da. method is called, the ‘yield’ returns *note None: 886.

Here’s the previous example, modified to allow changing the value of the
internal counter.

     def counter (maximum):
         i = 0
         while i < maximum:
             val = (yield i)
             # If value provided, change counter
             if val is not None:
                 i = val
             else:
                 i += 1

And here’s an example of changing the counter:

     >>> it = counter(10)
     >>> print it.next()
     0
     >>> print it.next()
     1
     >>> print it.send(8)
     8
     >>> print it.next()
     9
     >>> print it.next()
     Traceback (most recent call last):
       File "t.py", line 15, in ?
         print it.next()
     StopIteration

*note yield: bc4. will usually return *note None: 886, so you should
always check for this case.  Don’t just use its value in expressions
unless you’re sure that the ‘send()’ method will be the only method used
to resume your generator function.

In addition to ‘send()’, there are two other new methods on generators:

   * ‘throw(type, value=None, traceback=None)’ is used to raise an
     exception inside the generator; the exception is raised by the
     *note yield: bc4. expression where the generator’s execution is
     paused.

   * ‘close()’ raises a new *note GeneratorExit: 15cf. exception inside
     the generator to terminate the iteration.  On receiving this
     exception, the generator’s code must either raise *note
     GeneratorExit: 15cf. or *note StopIteration: df7.  Catching the
     *note GeneratorExit: 15cf. exception and returning a value is
     illegal and will trigger a *note RuntimeError: 244.; if the
     function raises some other exception, that exception is propagated
     to the caller.  ‘close()’ will also be called by Python’s garbage
     collector when the generator is garbage-collected.

     If you need to run cleanup code when a *note GeneratorExit: 15cf.
     occurs, I suggest using a ‘try: ... finally:’ suite instead of
     catching *note GeneratorExit: 15cf.

The cumulative effect of these changes is to turn generators from
one-way producers of information into both producers and consumers.

Generators also become 'coroutines', a more generalized form of
subroutines.  Subroutines are entered at one point and exited at another
point (the top of the function, and a *note return: 1af. statement), but
coroutines can be entered, exited, and resumed at many different points
(the *note yield: bc4. statements).  We’ll have to figure out patterns
for using coroutines effectively in Python.

The addition of the ‘close()’ method has one side effect that isn’t
obvious.  ‘close()’ is called when a generator is garbage-collected, so
this means the generator’s code gets one last chance to run before the
generator is destroyed.  This last chance means that ‘try...finally’
statements in generators can now be guaranteed to work; the *note
finally: 1b0. clause will now always get a chance to run.  The syntactic
restriction that you couldn’t mix *note yield: bc4. statements with a
‘try...finally’ suite has therefore been removed.  This seems like a
minor bit of language trivia, but using generators and ‘try...finally’
is actually necessary in order to implement the *note with: 186.
statement described by PEP 343(2).  I’ll look at this new statement in
the following section.

Another even more esoteric effect of this change: previously, the
‘gi_frame’ attribute of a generator was always a frame object.  It’s now
possible for ‘gi_frame’ to be ‘None’ once the generator has been
exhausted.

Vedi anche
..........

PEP 342(3) - Coroutines via Enhanced Generators

     PEP written by Guido van Rossum and Phillip J. Eby; implemented by
     Phillip J. Eby.  Includes examples of some fancier uses of
     generators as coroutines.

     Earlier versions of these features were proposed in PEP 288(4) by
     Raymond Hettinger and PEP 325(5) by Samuele Pedroni.

‘https://en.wikipedia.org/wiki/Coroutine’

     The Wikipedia entry for coroutines.

‘https://web.archive.org/web/20160321211320/http://www.sidhe.org/~dan/blog/archives/000178.html’

     An explanation of coroutines from a Perl point of view, written by
     Dan Sugalski.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0342/

   (2) https://peps.python.org/pep-0343/

   (3) https://peps.python.org/pep-0342/

   (4) https://peps.python.org/pep-0288/

   (5) https://peps.python.org/pep-0325/


File: python.info,  Node: PEP 343 The “with” statement<2>,  Next: PEP 352 Exceptions as New-Style Classes,  Prev: PEP 342 New Generator Features,  Up: What’s New in Python 2 5

1.18.8 PEP 343: The “with” statement
------------------------------------

The “*note with: 186.” statement clarifies code that previously would
use ‘try...finally’ blocks to ensure that clean-up code is executed.  In
this section, I’ll discuss the statement as it will commonly be used.
In the next section, I’ll examine the implementation details and show
how to write objects for use with this statement.

The “*note with: 186.” statement is a new control-flow structure whose
basic structure is:

     with expression [as variable]:
         with-block

The expression is evaluated, and it should result in an object that
supports the context management protocol (that is, has *note
__enter__(): 7e5. and *note __exit__(): 1508. methods.

The object’s *note __enter__(): 7e5. is called before 'with-block' is
executed and therefore can run set-up code.  It also may return a value
that is bound to the name 'variable', if given.  (Note carefully that
'variable' is 'not' assigned the result of 'expression'.)

After execution of the 'with-block' is finished, the object’s *note
__exit__(): 1508. method is called, even if the block raised an
exception, and can therefore run clean-up code.

To enable the statement in Python 2.5, you need to add the following
directive to your module:

     from __future__ import with_statement

The statement will always be enabled in Python 2.6.

Some standard Python objects now support the context management protocol
and can be used with the “*note with: 186.” statement.  File objects are
one example:

     with open('/etc/passwd', 'r') as f:
         for line in f:
             print line
             ... more processing code ...

After this statement has executed, the file object in 'f' will have been
automatically closed, even if the *note for: 34a. loop raised an
exception part-way through the block.

     Nota: In this case, 'f' is the same object created by *note open():
     316, because *note __enter__(): 7e5. returns 'self'.

The *note threading: f3. module’s locks and condition variables also
support the “*note with: 186.” statement:

     lock = threading.Lock()
     with lock:
         # Critical section of code
         ...

The lock is acquired before the block is executed and always released
once the block is complete.

The new ‘localcontext()’ function in the *note decimal: 3a. module makes
it easy to save and restore the current decimal context, which
encapsulates the desired precision and rounding characteristics for
computations:

     from decimal import Decimal, Context, localcontext

     # Displays with default precision of 28 digits
     v = Decimal('578')
     print v.sqrt()

     with localcontext(Context(prec=16)):
         # All code in this block uses a precision of 16 digits.
         # The original context is restored on exiting the block.
         print v.sqrt()

* Menu:

* Writing Context Managers: Writing Context Managers<2>.
* The contextlib module: The contextlib module<2>.


File: python.info,  Node: Writing Context Managers<2>,  Next: The contextlib module<2>,  Up: PEP 343 The “with” statement<2>

1.18.8.1 Writing Context Managers
.................................

Under the hood, the “*note with: 186.” statement is fairly complicated.
Most people will only use “‘with’” in company with existing objects and
don’t need to know these details, so you can skip the rest of this
section if you like.  Authors of new objects will need to understand the
details of the underlying implementation and should keep reading.

A high-level explanation of the context management protocol is:

   * The expression is evaluated and should result in an object called a
     «context manager».  The context manager must have *note
     __enter__(): 7e5. and *note __exit__(): 1508. methods.

   * The context manager’s *note __enter__(): 7e5. method is called.
     The value returned is assigned to 'VAR'. If no ‘'as VAR'’ clause is
     present, the value is simply discarded.

   * The code in 'BLOCK' is executed.

   * If 'BLOCK' raises an exception, the ‘__exit__(type, value,
     traceback)’ is called with the exception details, the same values
     returned by *note sys.exc_info(): 89b.  The method’s return value
     controls whether the exception is re-raised: any false value
     re-raises the exception, and ‘True’ will result in suppressing it.
     You’ll only rarely want to suppress the exception, because if you
     do the author of the code containing the “*note with: 186.”
     statement will never realize anything went wrong.

   * If 'BLOCK' didn’t raise an exception, the *note __exit__(): 1508.
     method is still called, but 'type', 'value', and 'traceback' are
     all ‘None’.

Let’s think through an example.  I won’t present detailed code but will
only sketch the methods necessary for a database that supports
transactions.

(For people unfamiliar with database terminology: a set of changes to
the database are grouped into a transaction.  Transactions can be either
committed, meaning that all the changes are written into the database,
or rolled back, meaning that the changes are all discarded and the
database is unchanged.  See any database textbook for more information.)

Let’s assume there’s an object representing a database connection.  Our
goal will be to let the user write code like this:

     db_connection = DatabaseConnection()
     with db_connection as cursor:
         cursor.execute('insert into ...')
         cursor.execute('delete from ...')
         # ... more operations ...

The transaction should be committed if the code in the block runs
flawlessly or rolled back if there’s an exception.  Here’s the basic
interface for ‘DatabaseConnection’ that I’ll assume:

     class DatabaseConnection:
         # Database interface
         def cursor (self):
             "Returns a cursor object and starts a new transaction"
         def commit (self):
             "Commits current transaction"
         def rollback (self):
             "Rolls back current transaction"

The *note __enter__(): 7e5. method is pretty easy, having only to start
a new transaction.  For this application the resulting cursor object
would be a useful result, so the method will return it.  The user can
then add ‘as cursor’ to their “*note with: 186.” statement to bind the
cursor to a variable name.

     class DatabaseConnection:
         ...
         def __enter__ (self):
             # Code to start a new transaction
             cursor = self.cursor()
             return cursor

The *note __exit__(): 1508. method is the most complicated because it’s
where most of the work has to be done.  The method has to check if an
exception occurred.  If there was no exception, the transaction is
committed.  The transaction is rolled back if there was an exception.

In the code below, execution will just fall off the end of the function,
returning the default value of ‘None’.  ‘None’ is false, so the
exception will be re-raised automatically.  If you wished, you could be
more explicit and add a *note return: 1af. statement at the marked
location.

     class DatabaseConnection:
         ...
         def __exit__ (self, type, value, tb):
             if tb is None:
                 # No exception, so commit
                 self.commit()
             else:
                 # Exception occurred, so rollback.
                 self.rollback()
                 # return False


File: python.info,  Node: The contextlib module<2>,  Prev: Writing Context Managers<2>,  Up: PEP 343 The “with” statement<2>

1.18.8.2 The contextlib module
..............................

The new *note contextlib: 27. module provides some functions and a
decorator that are useful for writing objects for use with the “*note
with: 186.” statement.

The decorator is called ‘contextmanager()’, and lets you write a single
generator function instead of defining a new class.  The generator
should yield exactly one value.  The code up to the *note yield: bc4.
will be executed as the *note __enter__(): 7e5. method, and the value
yielded will be the method’s return value that will get bound to the
variable in the “*note with: 186.” statement’s ‘as’ clause, if any.  The
code after the *note yield: bc4. will be executed in the *note
__exit__(): 1508. method.  Any exception raised in the block will be
raised by the ‘yield’ statement.

Our database example from the previous section could be written using
this decorator as:

     from contextlib import contextmanager

     @contextmanager
     def db_transaction (connection):
         cursor = connection.cursor()
         try:
             yield cursor
         except:
             connection.rollback()
             raise
         else:
             connection.commit()

     db = DatabaseConnection()
     with db_transaction(db) as cursor:
         ...

The *note contextlib: 27. module also has a ‘nested(mgr1, mgr2, ...)’
function that combines a number of context managers so you don’t need to
write nested “*note with: 186.” statements.  In this example, the single
“‘with’” statement both starts a database transaction and acquires a
thread lock:

     lock = threading.Lock()
     with nested (db_transaction(db), lock) as (cursor, locked):
         ...

Finally, the ‘closing(object)’ function returns 'object' so that it can
be bound to a variable, and calls ‘object.close’ at the end of the
block.

     import urllib, sys
     from contextlib import closing

     with closing(urllib.urlopen('http://www.yahoo.com')) as f:
         for line in f:
             sys.stdout.write(line)

Vedi anche
..........

PEP 343(1) - The «with» statement

     PEP written by Guido van Rossum and Nick Coghlan; implemented by
     Mike Bland, Guido van Rossum, and Neal Norwitz.  The PEP shows the
     code generated for a “*note with: 186.” statement, which can be
     helpful in learning how the statement works.

The documentation for the *note contextlib: 27. module.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0343/


File: python.info,  Node: PEP 352 Exceptions as New-Style Classes,  Next: PEP 353 Using ssize_t as the index type,  Prev: PEP 343 The “with” statement<2>,  Up: What’s New in Python 2 5

1.18.9 PEP 352: Exceptions as New-Style Classes
-----------------------------------------------

Exception classes can now be new-style classes, not just classic
classes, and the built-in *note Exception: bcf. class and all the
standard built-in exceptions (*note NameError: 452, *note ValueError:
2ec, etc.)  are now new-style classes.

The inheritance hierarchy for exceptions has been rearranged a bit.  In
2.5, the inheritance relationships are:

     BaseException       # New in Python 2.5
     |- KeyboardInterrupt
     |- SystemExit
     |- Exception
        |- (all other current built-in exceptions)

This rearrangement was done because people often want to catch all
exceptions that indicate program errors.  *note KeyboardInterrupt: bc7.
and *note SystemExit: f3e. aren’t errors, though, and usually represent
an explicit action such as the user hitting ‘Control’-‘C’ or code
calling *note sys.exit(): 277.  A bare ‘except:’ will catch all
exceptions, so you commonly need to list *note KeyboardInterrupt: bc7.
and *note SystemExit: f3e. in order to re-raise them.  The usual pattern
is:

     try:
         ...
     except (KeyboardInterrupt, SystemExit):
         raise
     except:
         # Log error...
         # Continue running program...

In Python 2.5, you can now write ‘except Exception’ to achieve the same
result, catching all the exceptions that usually indicate errors but
leaving *note KeyboardInterrupt: bc7. and *note SystemExit: f3e. alone.
As in previous versions, a bare ‘except:’ still catches all exceptions.

The goal for Python 3.0 is to require any class raised as an exception
to derive from *note BaseException: 7d8. or some descendant of *note
BaseException: 7d8, and future releases in the Python 2.x series may
begin to enforce this constraint.  Therefore, I suggest you begin making
all your exception classes derive from *note Exception: bcf. now.  It’s
been suggested that the bare ‘except:’ form should be removed in Python
3.0, but Guido van Rossum hasn’t decided whether to do this or not.

Raising of strings as exceptions, as in the statement ‘raise "Error
occurred"’, is deprecated in Python 2.5 and will trigger a warning.  The
aim is to be able to remove the string-exception feature in a few
releases.

Vedi anche
..........

PEP 352(1) - Required Superclass for Exceptions

     PEP written by Brett Cannon and Guido van Rossum; implemented by
     Brett Cannon.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0352/


File: python.info,  Node: PEP 353 Using ssize_t as the index type,  Next: PEP 357 The “__index__” method,  Prev: PEP 352 Exceptions as New-Style Classes,  Up: What’s New in Python 2 5

1.18.10 PEP 353: Using ssize_t as the index type
------------------------------------------------

A wide-ranging change to Python’s C API, using a new *note Py_ssize_t:
c57. type definition instead of int, will permit the interpreter to
handle more data on 64-bit platforms.  This change doesn’t affect
Python’s capacity on 32-bit platforms.

Various pieces of the Python interpreter used C’s int type to store
sizes or counts; for example, the number of items in a list or tuple
were stored in an int.  The C compilers for most 64-bit platforms still
define int as a 32-bit type, so that meant that lists could only hold up
to ‘2**31 - 1’ = 2147483647 items.  (There are actually a few different
programming models that 64-bit C compilers can use – see
‘https://unix.org/version2/whatsnew/lp64_wp.html’ for a discussion – but
the most commonly available model leaves int as 32 bits.)

A limit of 2147483647 items doesn’t really matter on a 32-bit platform
because you’ll run out of memory before hitting the length limit.  Each
list item requires space for a pointer, which is 4 bytes, plus space for
a *note PyObject: 5df. representing the item.  2147483647*4 is already
more bytes than a 32-bit address space can contain.

It’s possible to address that much memory on a 64-bit platform, however.
The pointers for a list that size would only require 16 GiB of space, so
it’s not unreasonable that Python programmers might construct lists that
large.  Therefore, the Python interpreter had to be changed to use some
type other than int, and this will be a 64-bit type on 64-bit platforms.
The change will cause incompatibilities on 64-bit machines, so it was
deemed worth making the transition now, while the number of 64-bit users
is still relatively small.  (In 5 or 10 years, we may 'all' be on 64-bit
machines, and the transition would be more painful then.)

This change most strongly affects authors of C extension modules.
Python strings and container types such as lists and tuples now use
*note Py_ssize_t: c57. to store their size.  Functions such as *note
PyList_Size(): 1621. now return *note Py_ssize_t: c57.  Code in
extension modules may therefore need to have some variables changed to
*note Py_ssize_t: c57.

The *note PyArg_ParseTuple(): 3c1. and *note Py_BuildValue(): 3c2.
functions have a new conversion code, ‘n’, for *note Py_ssize_t: c57.
*note PyArg_ParseTuple(): 3c1.”s ‘s#’ and ‘t#’ still output int by
default, but you can define the macro ‘PY_SSIZE_T_CLEAN’ before
including ‘Python.h’ to make them return *note Py_ssize_t: c57.

PEP 353(1) has a section on conversion guidelines that extension authors
should read to learn about supporting 64-bit platforms.

Vedi anche
..........

PEP 353(2) - Using ssize_t as the index type

     PEP written and implemented by Martin von Löwis.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0353/

   (2) https://peps.python.org/pep-0353/


File: python.info,  Node: PEP 357 The “__index__” method,  Next: Other Language Changes<15>,  Prev: PEP 353 Using ssize_t as the index type,  Up: What’s New in Python 2 5

1.18.11 PEP 357: The “__index__” method
---------------------------------------

The NumPy developers had a problem that could only be solved by adding a
new special method, ‘__index__()’.  When using slice notation, as in
‘[start:stop:step]’, the values of the 'start', 'stop', and 'step'
indexes must all be either integers or long integers.  NumPy defines a
variety of specialized integer types corresponding to unsigned and
signed integers of 8, 16, 32, and 64 bits, but there was no way to
signal that these types could be used as slice indexes.

Slicing can’t just use the existing ‘__int__()’ method because that
method is also used to implement coercion to integers.  If slicing used
‘__int__()’, floating-point numbers would also become legal slice
indexes and that’s clearly an undesirable behaviour.

Instead, a new special method called ‘__index__()’ was added.  It takes
no arguments and returns an integer giving the slice index to use.  For
example:

     class C:
         def __index__ (self):
             return self.value

The return value must be either a Python integer or long integer.  The
interpreter will check that the type returned is correct, and raises a
*note TypeError: 198. if this requirement isn’t met.

A corresponding *note nb_index: 1624. slot was added to the C-level
*note PyNumberMethods: 1625. structure to let C extensions implement
this protocol.  ‘PyNumber_Index(obj)’ can be used in extension code to
call the ‘__index__()’ function and retrieve its result.

Vedi anche
..........

PEP 357(1) - Allowing Any Object to be Used for Slicing

     PEP written and implemented by Travis Oliphant.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0357/


File: python.info,  Node: Other Language Changes<15>,  Next: New Improved and Removed Modules,  Prev: PEP 357 The “__index__” method,  Up: What’s New in Python 2 5

1.18.12 Other Language Changes
------------------------------

Here are all of the changes that Python 2.5 makes to the core Python
language.

   * The *note dict: 183. type has a new hook for letting subclasses
     provide a default value when a key isn’t contained in the
     dictionary.  When a key isn’t found, the dictionary’s
     ‘__missing__(key)’ method will be called.  This hook is used to
     implement the new ‘defaultdict’ class in the *note collections: 1e.
     module.  The following example defines a dictionary that returns
     zero for any missing key:

          class zerodict (dict):
              def __missing__ (self, key):
                  return 0

          d = zerodict({1:1, 2:2})
          print d[1], d[2]   # Prints 1, 2
          print d[3], d[4]   # Prints 0, 0

   * Both 8-bit and Unicode strings have new ‘partition(sep)’ and
     ‘rpartition(sep)’ methods that simplify a common use case.

     The ‘find(S)’ method is often used to get an index which is then
     used to slice the string and obtain the pieces that are before and
     after the separator.  ‘partition(sep)’ condenses this pattern into
     a single method call that returns a 3-tuple containing the
     substring before the separator, the separator itself, and the
     substring after the separator.  If the separator isn’t found, the
     first element of the tuple is the entire string and the other two
     elements are empty.  ‘rpartition(sep)’ also returns a 3-tuple but
     starts searching from the end of the string; the ‘r’ stands for
     “reverse”.

     Some examples:

          >>> ('http://www.python.org').partition('://')
          ('http', '://', 'www.python.org')
          >>> ('file:/usr/share/doc/index.html').partition('://')
          ('file:/usr/share/doc/index.html', '', '')
          >>> (u'Subject: a quick question').partition(':')
          (u'Subject', u':', u' a quick question')
          >>> 'www.python.org'.rpartition('.')
          ('www.python', '.', 'org')
          >>> 'www.python.org'.rpartition(':')
          ('', '', 'www.python.org')

     (Implemented by Fredrik Lundh following a suggestion by Raymond
     Hettinger.)

   * The ‘startswith()’ and ‘endswith()’ methods of string types now
     accept tuples of strings to check for.

          def is_image_file (filename):
              return filename.endswith(('.gif', '.jpg', '.tiff'))

     (Implemented by Georg Brandl following a suggestion by Tom Lynn.)

   * The *note min(): 110d. and *note max(): 110e. built-in functions
     gained a ‘key’ keyword parameter analogous to the ‘key’ argument
     for ‘sort()’.  This parameter supplies a function that takes a
     single argument and is called for every value in the list; *note
     min(): 110d./*note max(): 110e. will return the element with the
     smallest/largest return value from this function.  For example, to
     find the longest string in a list, you can do:

          L = ['medium', 'longest', 'short']
          # Prints 'longest'
          print max(L, key=len)
          # Prints 'short', because lexicographically 'short' has the largest value
          print max(L)

     (Contributed by Steven Bethard and Raymond Hettinger.)

   * Two new built-in functions, *note any(): 1628. and *note all():
     1629, evaluate whether an iterator contains any true or false
     values.  *note any(): 1628. returns *note True: e09. if any value
     returned by the iterator is true; otherwise it will return *note
     False: d2d.  *note all(): 1629. returns *note True: e09. only if
     all of the values returned by the iterator evaluate as true.
     (Suggested by Guido van Rossum, and implemented by Raymond
     Hettinger.)

   * The result of a class’s ‘__hash__()’ method can now be either a
     long integer or a regular integer.  If a long integer is returned,
     the hash of that value is taken.  In earlier versions the hash
     value was required to be a regular integer, but in 2.5 the *note
     id(): 162a. built-in was changed to always return non-negative
     numbers, and users often seem to use ‘id(self)’ in ‘__hash__()’
     methods (though this is discouraged).

   * ASCII is now the default encoding for modules.  It’s now a syntax
     error if a module contains string literals with 8-bit characters
     but doesn’t have an encoding declaration.  In Python 2.4 this
     triggered a warning, not a syntax error.  See PEP 263(1) for how to
     declare a module’s encoding; for example, you might add a line like
     this near the top of the source file:

          # -*- coding: latin1 -*-

   * A new warning, *note UnicodeWarning: 162b, is triggered when you
     attempt to compare a Unicode string and an 8-bit string that can’t
     be converted to Unicode using the default ASCII encoding.  The
     result of the comparison is false:

          >>> chr(128) == unichr(128)   # Can't convert chr(128) to Unicode
          __main__:1: UnicodeWarning: Unicode equal comparison failed
            to convert both arguments to Unicode - interpreting them
            as being unequal
          False
          >>> chr(127) == unichr(127)   # chr(127) can be converted
          True

     Previously this would raise a *note UnicodeDecodeError: c0a.
     exception, but in 2.5 this could result in puzzling problems when
     accessing a dictionary.  If you looked up ‘unichr(128)’ and
     ‘chr(128)’ was being used as a key, you’d get a *note
     UnicodeDecodeError: c0a. exception.  Other changes in 2.5 resulted
     in this exception being raised instead of suppressed by the code in
     ‘dictobject.c’ that implements dictionaries.

     Raising an exception for such a comparison is strictly correct, but
     the change might have broken code, so instead *note UnicodeWarning:
     162b. was introduced.

     (Implemented by Marc-André Lemburg.)

   * One error that Python programmers sometimes make is forgetting to
     include an ‘__init__.py’ module in a package directory.  Debugging
     this mistake can be confusing, and usually requires running Python
     with the *note -v: 162c. switch to log all the paths searched.  In
     Python 2.5, a new *note ImportWarning: 71f. warning is triggered
     when an import would have picked up a directory as a package but no
     ‘__init__.py’ was found.  This warning is silently ignored by
     default; provide the *note -Wd: ac7. option when running the Python
     executable to display the warning message.  (Implemented by Thomas
     Wouters.)

   * The list of base classes in a class definition can now be empty.
     As an example, this is now legal:

          class C():
              pass

     (Implemented by Brett Cannon.)

* Menu:

* Interactive Interpreter Changes::
* Optimizations: Optimizations<15>.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0263/


File: python.info,  Node: Interactive Interpreter Changes,  Next: Optimizations<15>,  Up: Other Language Changes<15>

1.18.12.1 Interactive Interpreter Changes
.........................................

In the interactive interpreter, ‘quit’ and ‘exit’ have long been strings
so that new users get a somewhat helpful message when they try to quit:

     >>> quit
     'Use Ctrl-D (i.e. EOF) to exit.'

In Python 2.5, ‘quit’ and ‘exit’ are now objects that still produce
string representations of themselves, but are also callable.  Newbies
who try ‘quit()’ or ‘exit()’ will now exit the interpreter as they
expect.  (Implemented by Georg Brandl.)

The Python executable now accepts the standard long options *note -help:
807. and *note -version: f19.; on Windows, it also accepts the *note /?:
162f. option for displaying a help message.  (Implemented by Georg
Brandl.)


File: python.info,  Node: Optimizations<15>,  Prev: Interactive Interpreter Changes,  Up: Other Language Changes<15>

1.18.12.2 Optimizations
.......................

Several of the optimizations were developed at the NeedForSpeed sprint,
an event held in Reykjavik, Iceland, from May 21–28 2006.  The sprint
focused on speed enhancements to the CPython implementation and was
funded by EWT LLC with local support from CCP Games.  Those
optimizations added at this sprint are specially marked in the following
list.

   * When they were introduced in Python 2.4, the built-in *note set:
     184. and *note frozenset: 7f3. types were built on top of Python’s
     dictionary type.  In 2.5 the internal data structure has been
     customized for implementing sets, and as a result sets will use a
     third less memory and are somewhat faster.  (Implemented by Raymond
     Hettinger.)

   * The speed of some Unicode operations, such as finding substrings,
     string splitting, and character map encoding and decoding, has been
     improved.  (Substring search and splitting improvements were added
     by Fredrik Lundh and Andrew Dalke at the NeedForSpeed sprint.
     Character maps were improved by Walter Dörwald and Martin von
     Löwis.)

   * The ‘long(str, base)’ function is now faster on long digit strings
     because fewer intermediate results are calculated.  The peak is for
     strings of around 800–1000 digits where the function is 6 times
     faster.  (Contributed by Alan McIntyre and committed at the
     NeedForSpeed sprint.)

   * It’s now illegal to mix iterating over a file with ‘for line in
     file’ and calling the file object’s ‘read()’/*note readline():
     bf./‘readlines()’ methods.  Iteration uses an internal buffer and
     the ‘read*()’ methods don’t use that buffer.  Instead they would
     return the data following the buffer, causing the data to appear
     out of order.  Mixing iteration and these methods will now trigger
     a *note ValueError: 2ec. from the ‘read*()’ method.  (Implemented
     by Thomas Wouters.)

   * The *note struct: db. module now compiles structure format strings
     into an internal representation and caches this representation,
     yielding a 20% speedup.  (Contributed by Bob Ippolito at the
     NeedForSpeed sprint.)

   * The *note re: be. module got a 1 or 2% speedup by switching to
     Python’s allocator functions instead of the system’s ‘malloc()’ and
     ‘free()’.  (Contributed by Jack Diederich at the NeedForSpeed
     sprint.)

   * The code generator’s peephole optimizer now performs simple
     constant folding in expressions.  If you write something like ‘a =
     2+3’, the code generator will do the arithmetic and produce code
     corresponding to ‘a = 5’.  (Proposed and implemented by Raymond
     Hettinger.)

   * Function calls are now faster because code objects now keep the
     most recently finished frame (a «zombie frame») in an internal
     field of the code object, reusing it the next time the code object
     is invoked.  (Original patch by Michael Hudson, modified by Armin
     Rigo and Richard Jones; committed at the NeedForSpeed sprint.)
     Frame objects are also slightly smaller, which may improve cache
     locality and reduce memory usage a bit.  (Contributed by Neal
     Norwitz.)

   * Python’s built-in exceptions are now new-style classes, a change
     that speeds up instantiation considerably.  Exception handling in
     Python 2.5 is therefore about 30% faster than in 2.4.  (Contributed
     by Richard Jones, Georg Brandl and Sean Reifschneider at the
     NeedForSpeed sprint.)

   * Importing now caches the paths tried, recording whether they exist
     or not so that the interpreter makes fewer ‘open()’ and ‘stat()’
     calls on startup.  (Contributed by Martin von Löwis and Georg
     Brandl.)


File: python.info,  Node: New Improved and Removed Modules,  Next: Build and C API Changes<10>,  Prev: Other Language Changes<15>,  Up: What’s New in Python 2 5

1.18.13 New, Improved, and Removed Modules
------------------------------------------

The standard library received many enhancements and bug fixes in Python
2.5.  Here’s a partial list of the most notable changes, sorted
alphabetically by module name.  Consult the ‘Misc/NEWS’ file in the
source tree for a more complete list of changes, or look through the SVN
logs for all the details.

   * The ‘audioop’ module now supports the a-LAW encoding, and the code
     for u-LAW encoding has been improved.  (Contributed by Lars
     Immisch.)

   * The *note codecs: 1c. module gained support for incremental codecs.
     The ‘codec.lookup()’ function now returns a ‘CodecInfo’ instance
     instead of a tuple.  ‘CodecInfo’ instances behave like a 4-tuple to
     preserve backward compatibility but also have the attributes
     ‘encode’, ‘decode’, ‘incrementalencoder’, ‘incrementaldecoder’,
     ‘streamwriter’, and ‘streamreader’.  Incremental codecs can receive
     input and produce output in multiple chunks; the output is the same
     as if the entire input was fed to the non-incremental codec.  See
     the *note codecs: 1c. module documentation for details.  (Designed
     and implemented by Walter Dörwald.)

   * The *note collections: 1e. module gained a new type, ‘defaultdict’,
     that subclasses the standard *note dict: 183. type.  The new type
     mostly behaves like a dictionary but constructs a default value
     when a key isn’t present, automatically adding it to the dictionary
     for the requested key value.

     The first argument to ‘defaultdict’’s constructor is a factory
     function that gets called whenever a key is requested but not
     found.  This factory function receives no arguments, so you can use
     built-in type constructors such as *note list(): 24d. or *note
     int(): 19b.  For example, you can make an index of words based on
     their initial letter like this:

          words = """Nel mezzo del cammin di nostra vita
          mi ritrovai per una selva oscura
          che la diritta via era smarrita""".lower().split()

          index = defaultdict(list)

          for w in words:
              init_letter = w[0]
              index[init_letter].append(w)

     Printing ‘index’ results in the following output:

          defaultdict(<type 'list'>, {'c': ['cammin', 'che'], 'e': ['era'],
                  'd': ['del', 'di', 'diritta'], 'm': ['mezzo', 'mi'],
                  'l': ['la'], 'o': ['oscura'], 'n': ['nel', 'nostra'],
                  'p': ['per'], 's': ['selva', 'smarrita'],
                  'r': ['ritrovai'], 'u': ['una'], 'v': ['vita', 'via']}

     (Contributed by Guido van Rossum.)

   * The ‘deque’ double-ended queue type supplied by the *note
     collections: 1e. module now has a ‘remove(value)’ method that
     removes the first occurrence of 'value' in the queue, raising *note
     ValueError: 2ec. if the value isn’t found.  (Contributed by Raymond
     Hettinger.)

   * New module: The *note contextlib: 27. module contains helper
     functions for use with the new “*note with: 186.” statement.  See
     section *note The contextlib module: 161b. for more about this
     module.

   * New module: The *note cProfile: 2b. module is a C implementation of
     the existing *note profile: b4. module that has much lower
     overhead.  The module’s interface is the same as *note profile:
     b4.: you run ‘cProfile.run('main()')’ to profile a function, can
     save profile data to a file, etc.  It’s not yet known if the
     Hotshot profiler, which is also written in C but doesn’t match the
     *note profile: b4. module’s interface, will continue to be
     maintained in future versions of Python.  (Contributed by Armin
     Rigo.)

     Also, the *note pstats: b5. module for analyzing the data measured
     by the profiler now supports directing the output to any file
     object by supplying a 'stream' argument to the ‘Stats’ constructor.
     (Contributed by Skip Montanaro.)

   * The *note csv: 2d. module, which parses files in comma-separated
     value format, received several enhancements and a number of
     bugfixes.  You can now set the maximum size in bytes of a field by
     calling the ‘csv.field_size_limit(new_limit)’ function; omitting
     the 'new_limit' argument will return the currently set limit.  The
     ‘reader’ class now has a ‘line_num’ attribute that counts the
     number of physical lines read from the source; records can span
     multiple physical lines, so ‘line_num’ is not the same as the
     number of records read.

     The CSV parser is now stricter about multi-line quoted fields.
     Previously, if a line ended within a quoted field without a
     terminating newline character, a newline would be inserted into the
     returned field.  This behavior caused problems when reading files
     that contained carriage return characters within fields, so the
     code was changed to return the field without inserting newlines.
     As a consequence, if newlines embedded within fields are important,
     the input should be split into lines in a manner that preserves the
     newline characters.

     (Contributed by Skip Montanaro and Andrew McNamara.)

   * The *note datetime: 4e3. class in the *note datetime: 34. module
     now has a ‘strptime(string, format)’ method for parsing date
     strings, contributed by Josh Spoerri.  It uses the same format
     characters as *note time.strptime(): 1634. and *note
     time.strftime(): 13f1.:

          from datetime import datetime

          ts = datetime.strptime('10:13:15 2006-03-07',
                                 '%H:%M:%S %Y-%m-%d')

   * The ‘SequenceMatcher.get_matching_blocks()’ method in the *note
     difflib: 3b. module now guarantees to return a minimal list of
     blocks describing matching subsequences.  Previously, the algorithm
     would occasionally break a block of matching elements into two list
     entries.  (Enhancement by Tim Peters.)

   * The *note doctest: 3e. module gained a ‘SKIP’ option that keeps an
     example from being executed at all.  This is intended for code
     snippets that are usage examples intended for the reader and aren’t
     actually test cases.

     An 'encoding' parameter was added to the ‘testfile()’ function and
     the ‘DocFileSuite’ class to specify the file’s encoding.  This
     makes it easier to use non-ASCII characters in tests contained
     within a docstring.  (Contributed by Bjorn Tillenius.)

   * The *note email: 3f. package has been updated to version 4.0.
     (Contributed by Barry Warsaw.)

   * The *note fileinput: 5f. module was made more flexible.  Unicode
     filenames are now supported, and a 'mode' parameter that defaults
     to ‘"r"’ was added to the *note input(): 14e0. function to allow
     opening files in binary or *note universal newlines: f37. mode.
     Another new parameter, 'openhook', lets you use a function other
     than *note open(): 316. to open the input files.  Once you’re
     iterating over the set of files, the ‘FileInput’ object’s new *note
     fileno(): 1635. returns the file descriptor for the currently
     opened file.  (Contributed by Georg Brandl.)

   * In the *note gc: 64. module, the new ‘get_count()’ function returns
     a 3-tuple containing the current collection counts for the three GC
     generations.  This is accounting information for the garbage
     collector; when these counts reach a specified threshold, a garbage
     collection sweep will be made.  The existing *note gc.collect():
     1b3. function now takes an optional 'generation' argument of 0, 1,
     or 2 to specify which generation to collect.  (Contributed by Barry
     Warsaw.)

   * The ‘nsmallest()’ and ‘nlargest()’ functions in the *note heapq:
     6d. module now support a ‘key’ keyword parameter similar to the one
     provided by the *note min(): 110d./*note max(): 110e. functions and
     the ‘sort()’ methods.  For example:

          >>> import heapq
          >>> L = ["short", 'medium', 'longest', 'longer still']
          >>> heapq.nsmallest(2, L)  # Return two lowest elements, lexicographically
          ['longer still', 'longest']
          >>> heapq.nsmallest(2, L, key=len)   # Return two shortest elements
          ['short', 'medium']

     (Contributed by Raymond Hettinger.)

   * The *note itertools.islice(): d45. function now accepts ‘None’ for
     the start and step arguments.  This makes it more compatible with
     the attributes of slice objects, so that you can now write the
     following:

          s = slice(5)     # Create slice object
          itertools.islice(iterable, s.start, s.stop, s.step)

     (Contributed by Raymond Hettinger.)

   * The *note format(): 199. function in the *note locale: 8a. module
     has been modified and two new functions were added,
     ‘format_string()’ and ‘currency()’.

     The *note format(): 199. function’s 'val' parameter could
     previously be a string as long as no more than one %char specifier
     appeared; now the parameter must be exactly one %char specifier
     with no surrounding text.  An optional 'monetary' parameter was
     also added which, if ‘True’, will use the locale’s rules for
     formatting currency in placing a separator between groups of three
     digits.

     To format strings with multiple %char specifiers, use the new
     ‘format_string()’ function that works like *note format(): 199. but
     also supports mixing %char specifiers with arbitrary text.

     A new ‘currency()’ function was also added that formats a number
     according to the current locale’s settings.

     (Contributed by Georg Brandl.)

   * The *note mailbox: 8f. module underwent a massive rewrite to add
     the capability to modify mailboxes in addition to reading them.  A
     new set of classes that include ‘mbox’, ‘MH’, and ‘Maildir’ are
     used to read mailboxes, and have an ‘add(message)’ method to add
     messages, ‘remove(key)’ to remove messages, and ‘lock()’/‘unlock()’
     to lock/unlock the mailbox.  The following example converts a
     maildir-format mailbox into an mbox-format one:

          import mailbox

          # 'factory=None' uses email.Message.Message as the class representing
          # individual messages.
          src = mailbox.Maildir('maildir', factory=None)
          dest = mailbox.mbox('/tmp/mbox')

          for msg in src:
              dest.add(msg)

     (Contributed by Gregory K. Johnson.  Funding was provided by
     Google’s 2005 Summer of Code.)

   * New module: the ‘msilib’ module allows creating Microsoft Installer
     ‘.msi’ files and CAB files.  Some support for reading the ‘.msi’
     database is also included.  (Contributed by Martin von Löwis.)

   * The ‘nis’ module now supports accessing domains other than the
     system default domain by supplying a 'domain' argument to the
     ‘nis.match()’ and ‘nis.maps()’ functions.  (Contributed by Ben
     Bell.)

   * The *note operator: a3. module’s ‘itemgetter()’ and ‘attrgetter()’
     functions now support multiple fields.  A call such as
     ‘operator.attrgetter('a', 'b')’ will return a function that
     retrieves the ‘a’ and ‘b’ attributes.  Combining this new feature
     with the ‘sort()’ method’s ‘key’ parameter lets you easily sort
     lists using multiple fields.  (Contributed by Raymond Hettinger.)

   * The *note optparse: a4. module was updated to version 1.5.1 of the
     Optik library.  The ‘OptionParser’ class gained an ‘epilog’
     attribute, a string that will be printed after the help message,
     and a ‘destroy()’ method to break reference cycles created by the
     object.  (Contributed by Greg Ward.)

   * The *note os: a5. module underwent several changes.  The
     ‘stat_float_times’ variable now defaults to true, meaning that
     *note os.stat(): 26d. will now return time values as floats.  (This
     doesn’t necessarily mean that *note os.stat(): 26d. will return
     times that are precise to fractions of a second; not all systems
     support such precision.)

     Constants named *note os.SEEK_SET: 1495, *note os.SEEK_CUR: 1496,
     and *note os.SEEK_END: 1497. have been added; these are the
     parameters to the *note os.lseek(): 131f. function.  Two new
     constants for locking are *note os.O_SHLOCK: 1636. and *note
     os.O_EXLOCK: 1637.

     Two new functions, ‘wait3()’ and ‘wait4()’, were added.  They’re
     similar the ‘waitpid()’ function which waits for a child process to
     exit and returns a tuple of the process ID and its exit status, but
     ‘wait3()’ and ‘wait4()’ return additional information.  ‘wait3()’
     doesn’t take a process ID as input, so it waits for any child
     process to exit and returns a 3-tuple of 'process-id',
     'exit-status', 'resource-usage' as returned from the *note
     resource.getrusage(): 1638. function.  ‘wait4(pid)’ does take a
     process ID. (Contributed by Chad J. Schroeder.)

     On FreeBSD, the *note os.stat(): 26d. function now returns times
     with nanosecond resolution, and the returned object now has
     ‘st_gen’ and ‘st_birthtime’.  The ‘st_flags’ attribute is also
     available, if the platform supports it.  (Contributed by Antti
     Louko and Diego Pettenò.)

   * The Python debugger provided by the *note pdb: aa. module can now
     store lists of commands to execute when a breakpoint is reached and
     execution stops.  Once breakpoint #1 has been created, enter
     ‘commands 1’ and enter a series of commands to be executed,
     finishing the list with ‘end’.  The command list can include
     commands that resume execution, such as ‘continue’ or ‘next’.
     (Contributed by Grégoire Dooms.)

   * The *note pickle: ab. and ‘cPickle’ modules no longer accept a
     return value of ‘None’ from the *note __reduce__(): bc8. method;
     the method must return a tuple of arguments instead.  The ability
     to return ‘None’ was deprecated in Python 2.4, so this completes
     the removal of the feature.

   * The *note pkgutil: ae. module, containing various utility functions
     for finding packages, was enhanced to support PEP 302(1)’s import
     hooks and now also works for packages stored in ZIP-format
     archives.  (Contributed by Phillip J. Eby.)

   * The pybench benchmark suite by Marc-André Lemburg is now included
     in the ‘Tools/pybench’ directory.  The pybench suite is an
     improvement on the commonly used ‘pystone.py’ program because
     pybench provides a more detailed measurement of the interpreter’s
     speed.  It times particular operations such as function calls,
     tuple slicing, method lookups, and numeric operations, instead of
     performing many different operations and reducing the result to a
     single number as ‘pystone.py’ does.

   * The ‘pyexpat’ module now uses version 2.0 of the Expat parser.
     (Contributed by Trent Mick.)

   * The *note Queue: 159c. class provided by the ‘Queue’ module gained
     two new methods.  ‘join()’ blocks until all items in the queue have
     been retrieved and all processing work on the items have been
     completed.  Worker threads call the other new method,
     ‘task_done()’, to signal that processing for an item has been
     completed.  (Contributed by Raymond Hettinger.)

   * The old ‘regex’ and ‘regsub’ modules, which have been deprecated
     ever since Python 2.0, have finally been deleted.  Other deleted
     modules: ‘statcache’, ‘tzparse’, ‘whrandom’.

   * Also deleted: the ‘lib-old’ directory, which includes ancient
     modules such as ‘dircmp’ and ‘ni’, was removed.  ‘lib-old’ wasn’t
     on the default ‘sys.path’, so unless your programs explicitly added
     the directory to ‘sys.path’, this removal shouldn’t affect your
     code.

   * The *note rlcompleter: c2. module is no longer dependent on
     importing the *note readline: bf. module and therefore now works on
     non-Unix platforms.  (Patch from Robert Kiendl.)

   * The *note SimpleXMLRPCServer: 135. and *note DocXMLRPCServer: 135.
     classes now have a ‘rpc_paths’ attribute that constrains XML-RPC
     operations to a limited set of URL paths; the default is to allow
     only ‘'/'’ and ‘'/RPC2'’.  Setting ‘rpc_paths’ to ‘None’ or an
     empty tuple disables this path checking.

   * The *note socket: d1. module now supports ‘AF_NETLINK’ sockets on
     Linux, thanks to a patch from Philippe Biondi.  Netlink sockets are
     a Linux-specific mechanism for communications between a user-space
     process and kernel code; an introductory article about them is at
     ‘https://www.linuxjournal.com/article/7356’.  In Python code,
     netlink addresses are represented as a tuple of 2 integers, ‘(pid,
     group_mask)’.

     Two new methods on socket objects, ‘recv_into(buffer)’ and
     ‘recvfrom_into(buffer)’, store the received data in an object that
     supports the buffer protocol instead of returning the data as a
     string.  This means you can put the data directly into an array or
     a memory-mapped file.

     Socket objects also gained ‘getfamily()’, ‘gettype()’, and
     ‘getproto()’ accessor methods to retrieve the family, type, and
     protocol values for the socket.

   * New module: the ‘spwd’ module provides functions for accessing the
     shadow password database on systems that support shadow passwords.

   * The *note struct: db. is now faster because it compiles format
     strings into ‘Struct’ objects with ‘pack()’ and ‘unpack()’ methods.
     This is similar to how the *note re: be. module lets you create
     compiled regular expression objects.  You can still use the
     module-level ‘pack()’ and ‘unpack()’ functions; they’ll create
     ‘Struct’ objects and cache them.  Or you can use ‘Struct’ instances
     directly:

          s = struct.Struct('ih3s')

          data = s.pack(1972, 187, 'abc')
          year, number, name = s.unpack(data)

     You can also pack and unpack data to and from buffer objects
     directly using the ‘pack_into(buffer, offset, v1, v2, ...)’ and
     ‘unpack_from(buffer, offset)’ methods.  This lets you store data
     directly into an array or a memory-mapped file.

     (‘Struct’ objects were implemented by Bob Ippolito at the
     NeedForSpeed sprint.  Support for buffer objects was added by
     Martin Blais, also at the NeedForSpeed sprint.)

   * The Python developers switched from CVS to Subversion during the
     2.5 development process.  Information about the exact build version
     is available as the ‘sys.subversion’ variable, a 3-tuple of
     ‘(interpreter-name, branch-name, revision-range)’.  For example, at
     the time of writing my copy of 2.5 was reporting ‘('CPython',
     'trunk', '45313:45315')’.

     This information is also available to C extensions via the *note
     Py_GetBuildInfo(): 1639. function that returns a string of build
     information like this: ‘"trunk:45355:45356M, Apr 13 2006,
     07:42:19"’.  (Contributed by Barry Warsaw.)

   * Another new function, *note sys._current_frames(): 163a, returns
     the current stack frames for all running threads as a dictionary
     mapping thread identifiers to the topmost stack frame currently
     active in that thread at the time the function is called.
     (Contributed by Tim Peters.)

   * The ‘TarFile’ class in the *note tarfile: e4. module now has an
     ‘extractall()’ method that extracts all members from the archive
     into the current working directory.  It’s also possible to set a
     different directory as the extraction target, and to unpack only a
     subset of the archive’s members.

     The compression used for a tarfile opened in stream mode can now be
     autodetected using the mode ‘'r|*'’.  (Contributed by Lars
     Gustäbel.)

   * The *note threading: f3. module now lets you set the stack size
     used when new threads are created.  The ‘stack_size([*size*])’
     function returns the currently configured stack size, and supplying
     the optional 'size' parameter sets a new value.  Not all platforms
     support changing the stack size, but Windows, POSIX threading, and
     OS/2 all do.  (Contributed by Andrew MacIntyre.)

   * The *note unicodedata: 10b. module has been updated to use version
     4.1.0 of the Unicode character database.  Version 3.2.0 is required
     by some specifications, so it’s still available as *note
     unicodedata.ucd_3_2_0: 163b.

   * New module: the *note uuid: 116. module generates universally
     unique identifiers (UUIDs) according to RFC 4122(2).  The RFC
     defines several different UUID versions that are generated from a
     starting string, from system properties, or purely randomly.  This
     module contains a ‘UUID’ class and functions named ‘uuid1()’,
     ‘uuid3()’, ‘uuid4()’, and ‘uuid5()’ to generate different versions
     of UUID. (Version 2 UUIDs are not specified in RFC 4122(3) and are
     not supported by this module.)

          >>> import uuid
          >>> # make a UUID based on the host ID and current time
          >>> uuid.uuid1()
          UUID('a8098c1a-f86e-11da-bd1a-00112444be1e')

          >>> # make a UUID using an MD5 hash of a namespace UUID and a name
          >>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org')
          UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')

          >>> # make a random UUID
          >>> uuid.uuid4()
          UUID('16fd2706-8baf-433b-82eb-8c7fada847da')

          >>> # make a UUID using a SHA-1 hash of a namespace UUID and a name
          >>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org')
          UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d')

     (Contributed by Ka-Ping Yee.)

   * The *note weakref: 11a. module’s ‘WeakKeyDictionary’ and
     ‘WeakValueDictionary’ types gained new methods for iterating over
     the weak references contained in the dictionary.  ‘iterkeyrefs()’
     and ‘keyrefs()’ methods were added to ‘WeakKeyDictionary’, and
     ‘itervaluerefs()’ and ‘valuerefs()’ were added to
     ‘WeakValueDictionary’.  (Contributed by Fred L. Drake, Jr.)

   * The *note webbrowser: 11b. module received a number of
     enhancements.  It’s now usable as a script with ‘python -m
     webbrowser’, taking a URL as the argument; there are a number of
     switches to control the behaviour (‘-n’ for a new browser window,
     ‘-t’ for a new tab).  New module-level functions, ‘open_new()’ and
     ‘open_new_tab()’, were added to support this.  The module’s *note
     open(): 316. function supports an additional feature, an
     'autoraise' parameter that signals whether to raise the open window
     when possible.  A number of additional browsers were added to the
     supported list such as Firefox, Opera, Konqueror, and elinks.
     (Contributed by Oleg Broytmann and Georg Brandl.)

   * The *note xmlrpclib: 134. module now supports returning *note
     datetime: 4e3. objects for the XML-RPC date type.  Supply
     ‘use_datetime=True’ to the *note loads(): 163c. function or the
     ‘Unmarshaller’ class to enable this feature.  (Contributed by Skip
     Montanaro.)

   * The *note zipfile: 137. module now supports the ZIP64 version of
     the format, meaning that a .zip archive can now be larger than 4
     GiB and can contain individual files larger than 4 GiB.
     (Contributed by Ronald Oussoren.)

   * The *note zlib: 139. module’s ‘Compress’ and ‘Decompress’ objects
     now support a *note copy(): 29. method that makes a copy of the
     object’s internal state and returns a new ‘Compress’ or
     ‘Decompress’ object.  (Contributed by Chris AtLee.)

* Menu:

* The ctypes package::
* The ElementTree package::
* The hashlib package::
* The sqlite3 package::
* The wsgiref package::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0302/

   (2) https://datatracker.ietf.org/doc/html/rfc4122.html

   (3) https://datatracker.ietf.org/doc/html/rfc4122.html


File: python.info,  Node: The ctypes package,  Next: The ElementTree package,  Up: New Improved and Removed Modules

1.18.13.1 The ctypes package
............................

The *note ctypes: 2e. package, written by Thomas Heller, has been added
to the standard library.  *note ctypes: 2e. lets you call arbitrary
functions in shared libraries or DLLs.  Long-time users may remember the
‘dl’ module, which provides functions for loading shared libraries and
calling functions in them.  The *note ctypes: 2e. package is much
fancier.

To load a shared library or DLL, you must create an instance of the
‘CDLL’ class and provide the name or path of the shared library or DLL.
Once that’s done, you can call arbitrary functions by accessing them as
attributes of the ‘CDLL’ object.

     import ctypes

     libc = ctypes.CDLL('libc.so.6')
     result = libc.printf("Line of output\n")

Type constructors for the various C types are provided: ‘c_int()’,
‘c_float()’, ‘c_double()’, ‘c_char_p()’ (equivalent to char*), and so
forth.  Unlike Python’s types, the C versions are all mutable; you can
assign to their ‘value’ attribute to change the wrapped value.  Python
integers and strings will be automatically converted to the
corresponding C types, but for other types you must call the correct
type constructor.  (And I mean 'must'; getting it wrong will often
result in the interpreter crashing with a segmentation fault.)

You shouldn’t use ‘c_char_p()’ with a Python string when the C function
will be modifying the memory area, because Python strings are supposed
to be immutable; breaking this rule will cause puzzling bugs.  When you
need a modifiable memory area, use ‘create_string_buffer()’:

     s = "this is a string"
     buf = ctypes.create_string_buffer(s)
     libc.strfry(buf)

C functions are assumed to return integers, but you can set the
‘restype’ attribute of the function object to change this:

     >>> libc.atof('2.71828')
     -1783957616
     >>> libc.atof.restype = ctypes.c_double
     >>> libc.atof('2.71828')
     2.71828

*note ctypes: 2e. also provides a wrapper for Python’s C API as the
‘ctypes.pythonapi’ object.  This object does 'not' release the global
interpreter lock before calling a function, because the lock must be
held when calling into the interpreter’s code.  There’s a *note
py_object: 1f3. type constructor that will create a *note PyObject:
5df.* pointer.  A simple usage:

     import ctypes

     d = {}
     ctypes.pythonapi.PyObject_SetItem(ctypes.py_object(d),
               ctypes.py_object("abc"),  ctypes.py_object(1))
     # d is now {'abc', 1}.

Don’t forget to use *note py_object(): 1f3.; if it’s omitted you end up
with a segmentation fault.

*note ctypes: 2e. has been around for a while, but people still write
and distribution hand-coded extension modules because you can’t rely on
*note ctypes: 2e. being present.  Perhaps developers will begin to write
Python wrappers atop a library accessed through *note ctypes: 2e.
instead of extension modules, now that *note ctypes: 2e. is included
with core Python.

Vedi anche
..........

‘https://web.archive.org/web/20180410025338/http://starship.python.net/crew/theller/ctypes/’

     The pre-stdlib ctypes web page, with a tutorial, reference, and
     FAQ.

The documentation for the *note ctypes: 2e. module.


File: python.info,  Node: The ElementTree package,  Next: The hashlib package,  Prev: The ctypes package,  Up: New Improved and Removed Modules

1.18.13.2 The ElementTree package
.................................

A subset of Fredrik Lundh’s ElementTree library for processing XML has
been added to the standard library as ‘xml.etree’.  The available
modules are ‘ElementTree’, ‘ElementPath’, and ‘ElementInclude’ from
ElementTree 1.2.6.  The ‘cElementTree’ accelerator module is also
included.

The rest of this section will provide a brief overview of using
ElementTree.  Full documentation for ElementTree is available at
‘https://web.archive.org/web/20201124024954/http://effbot.org/zone/element-index.htm’.

ElementTree represents an XML document as a tree of element nodes.  The
text content of the document is stored as the ‘text’ and ‘tail’
attributes of (This is one of the major differences between ElementTree
and the Document Object Model; in the DOM there are many different types
of node, including ‘TextNode’.)

The most commonly used parsing function is ‘parse()’, that takes either
a string (assumed to contain a filename) or a file-like object and
returns an ‘ElementTree’ instance:

     from xml.etree import ElementTree as ET

     tree = ET.parse('ex-1.xml')

     feed = urllib.urlopen(
               'http://planet.python.org/rss10.xml')
     tree = ET.parse(feed)

Once you have an ‘ElementTree’ instance, you can call its ‘getroot()’
method to get the root ‘Element’ node.

There’s also an ‘XML()’ function that takes a string literal and returns
an ‘Element’ node (not an ‘ElementTree’).  This function provides a tidy
way to incorporate XML fragments, approaching the convenience of an XML
literal:

     svg = ET.XML("""<svg width="10px" version="1.0">
                  </svg>""")
     svg.set('height', '320px')
     svg.append(elem1)

Each XML element supports some dictionary-like and some list-like access
methods.  Dictionary-like operations are used to access attribute
values, and list-like operations are used to access child nodes.

Operation                           Result
                                    
-------------------------------------------------------------------------------------
                                    
‘elem[n]’                           Returns n’th child element.
                                    
                                    
‘elem[m:n]’                         Returns list of m’th through n’th child
                                    elements.
                                    
                                    
‘len(elem)’                         Returns number of child elements.
                                    
                                    
‘list(elem)’                        Returns list of child elements.
                                    
                                    
‘elem.append(elem2)’                Adds 'elem2' as a child.
                                    
                                    
‘elem.insert(index, elem2)’         Inserts 'elem2' at the specified location.
                                    
                                    
‘del elem[n]’                       Deletes n’th child element.
                                    
                                    
‘elem.keys()’                       Returns list of attribute names.
                                    
                                    
‘elem.get(name)’                    Returns value of attribute 'name'.
                                    
                                    
‘elem.set(name, value)’             Sets new value for attribute 'name'.
                                    
                                    
‘elem.attrib’                       Retrieves the dictionary containing
                                    attributes.
                                    
                                    
‘del elem.attrib[name]’             Deletes attribute 'name'.
                                    

Comments and processing instructions are also represented as ‘Element’
nodes.  To check if a node is a comment or processing instructions:

     if elem.tag is ET.Comment:
         ...
     elif elem.tag is ET.ProcessingInstruction:
         ...

To generate XML output, you should call the ‘ElementTree.write()’
method.  Like ‘parse()’, it can take either a string or a file-like
object:

     # Encoding is US-ASCII
     tree.write('output.xml')

     # Encoding is UTF-8
     f = open('output.xml', 'w')
     tree.write(f, encoding='utf-8')

(Caution: the default encoding used for output is ASCII. For general XML
work, where an element’s name may contain arbitrary Unicode characters,
ASCII isn’t a very useful encoding because it will raise an exception if
an element’s name contains any characters with values greater than 127.
Therefore, it’s best to specify a different encoding such as UTF-8 that
can handle any Unicode character.)

This section is only a partial description of the ElementTree
interfaces.  Please read the package’s official documentation for more
details.

Vedi anche
..........

‘https://web.archive.org/web/20201124024954/http://effbot.org/zone/element-index.htm’

     Official documentation for ElementTree.


File: python.info,  Node: The hashlib package,  Next: The sqlite3 package,  Prev: The ElementTree package,  Up: New Improved and Removed Modules

1.18.13.3 The hashlib package
.............................

A new *note hashlib: 6c. module, written by Gregory P. Smith, has been
added to replace the ‘md5’ and ‘sha’ modules.  *note hashlib: 6c. adds
support for additional secure hashes (SHA-224, SHA-256, SHA-384, and
SHA-512).  When available, the module uses OpenSSL for fast platform
optimized implementations of algorithms.

The old ‘md5’ and ‘sha’ modules still exist as wrappers around hashlib
to preserve backwards compatibility.  The new module’s interface is very
close to that of the old modules, but not identical.  The most
significant difference is that the constructor functions for creating
new hashing objects are named differently.

     # Old versions
     h = md5.md5()
     h = md5.new()

     # New version
     h = hashlib.md5()

     # Old versions
     h = sha.sha()
     h = sha.new()

     # New version
     h = hashlib.sha1()

     # Hash that weren't previously available
     h = hashlib.sha224()
     h = hashlib.sha256()
     h = hashlib.sha384()
     h = hashlib.sha512()

     # Alternative form
     h = hashlib.new('md5')          # Provide algorithm as a string

Once a hash object has been created, its methods are the same as before:
‘update(string)’ hashes the specified string into the current digest
state, ‘digest()’ and ‘hexdigest()’ return the digest value as a binary
string or a string of hex digits, and *note copy(): 29. returns a new
hashing object with the same digest state.

Vedi anche
..........

The documentation for the *note hashlib: 6c. module.


File: python.info,  Node: The sqlite3 package,  Next: The wsgiref package,  Prev: The hashlib package,  Up: New Improved and Removed Modules

1.18.13.4 The sqlite3 package
.............................

The pysqlite module (‘https://www.pysqlite.org’), a wrapper for the
SQLite embedded database, has been added to the standard library under
the package name *note sqlite3: d4.

SQLite is a C library that provides a lightweight disk-based database
that doesn’t require a separate server process and allows accessing the
database using a nonstandard variant of the SQL query language.  Some
applications can use SQLite for internal data storage.  It’s also
possible to prototype an application using SQLite and then port the code
to a larger database such as PostgreSQL or Oracle.

pysqlite was written by Gerhard Häring and provides a SQL interface
compliant with the DB-API 2.0 specification described by PEP 249(1).

If you’re compiling the Python source yourself, note that the source
tree doesn’t include the SQLite code, only the wrapper module.  You’ll
need to have the SQLite libraries and headers installed before compiling
Python, and the build process will compile the module when the necessary
headers are available.

To use the module, you must first create a ‘Connection’ object that
represents the database.  Here the data will be stored in the
‘/tmp/example’ file:

     conn = sqlite3.connect('/tmp/example')

You can also supply the special name ‘:memory:’ to create a database in
RAM.

Once you have a ‘Connection’, you can create a ‘Cursor’ object and call
its ‘execute()’ method to perform SQL commands:

     c = conn.cursor()

     # Create table
     c.execute('''create table stocks
     (date text, trans text, symbol text,
      qty real, price real)''')

     # Insert a row of data
     c.execute("""insert into stocks
               values ('2006-01-05','BUY','RHAT',100,35.14)""")

Usually your SQL operations will need to use values from Python
variables.  You shouldn’t assemble your query using Python’s string
operations because doing so is insecure; it makes your program
vulnerable to an SQL injection attack.

Instead, use the DB-API’s parameter substitution.  Put ‘?’ as a
placeholder wherever you want to use a value, and then provide a tuple
of values as the second argument to the cursor’s ‘execute()’ method.
(Other database modules may use a different placeholder, such as ‘%s’ or
‘:1’.)  For example:

     # Never do this -- insecure!
     symbol = 'IBM'
     c.execute("... where symbol = '%s'" % symbol)

     # Do this instead
     t = (symbol,)
     c.execute('select * from stocks where symbol=?', t)

     # Larger example
     for t in (('2006-03-28', 'BUY', 'IBM', 1000, 45.00),
               ('2006-04-05', 'BUY', 'MSOFT', 1000, 72.00),
               ('2006-04-06', 'SELL', 'IBM', 500, 53.00),
              ):
         c.execute('insert into stocks values (?,?,?,?,?)', t)

To retrieve data after executing a SELECT statement, you can either
treat the cursor as an iterator, call the cursor’s ‘fetchone()’ method
to retrieve a single matching row, or call ‘fetchall()’ to get a list of
the matching rows.

This example uses the iterator form:

     >>> c = conn.cursor()
     >>> c.execute('select * from stocks order by price')
     >>> for row in c:
     ...    print row
     ...
     (u'2006-01-05', u'BUY', u'RHAT', 100, 35.140000000000001)
     (u'2006-03-28', u'BUY', u'IBM', 1000, 45.0)
     (u'2006-04-06', u'SELL', u'IBM', 500, 53.0)
     (u'2006-04-05', u'BUY', u'MSOFT', 1000, 72.0)
     >>>

For more information about the SQL dialect supported by SQLite, see
‘https://www.sqlite.org’.

Vedi anche
..........

‘https://www.pysqlite.org’

     The pysqlite web page.

‘https://www.sqlite.org’

     The SQLite web page; the documentation describes the syntax and the
     available data types for the supported SQL dialect.

The documentation for the *note sqlite3: d4. module.

PEP 249(2) - Database API Specification 2.0

     PEP written by Marc-André Lemburg.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0249/

   (2) https://peps.python.org/pep-0249/


File: python.info,  Node: The wsgiref package,  Prev: The sqlite3 package,  Up: New Improved and Removed Modules

1.18.13.5 The wsgiref package
.............................

The Web Server Gateway Interface (WSGI) v1.0 defines a standard
interface between web servers and Python web applications and is
described in PEP 333(1).  The *note wsgiref: 11e. package is a reference
implementation of the WSGI specification.

The package includes a basic HTTP server that will run a WSGI
application; this server is useful for debugging but isn’t intended for
production use.  Setting up a server takes only a few lines of code:

     from wsgiref import simple_server

     wsgi_app = ...

     host = ''
     port = 8000
     httpd = simple_server.make_server(host, port, wsgi_app)
     httpd.serve_forever()

Vedi anche
..........

‘https://web.archive.org/web/20160331090247/http://wsgi.readthedocs.org/en/latest/’

     A central web site for WSGI-related resources.

PEP 333(2) - Python Web Server Gateway Interface v1.0

     PEP written by Phillip J. Eby.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0333/

   (2) https://peps.python.org/pep-0333/


File: python.info,  Node: Build and C API Changes<10>,  Next: Porting to Python 2 5,  Prev: New Improved and Removed Modules,  Up: What’s New in Python 2 5

1.18.14 Build and C API Changes
-------------------------------

Changes to Python’s build process and to the C API include:

   * The Python source tree was converted from CVS to Subversion, in a
     complex migration procedure that was supervised and flawlessly
     carried out by Martin von Löwis.  The procedure was developed as
     PEP 347(1).

   * Coverity, a company that markets a source code analysis tool called
     Prevent, provided the results of their examination of the Python
     source code.  The analysis found about 60 bugs that were quickly
     fixed.  Many of the bugs were refcounting problems, often occurring
     in error-handling code.  See ‘https://scan.coverity.com’ for the
     statistics.

   * The largest change to the C API came from PEP 353(2), which
     modifies the interpreter to use a *note Py_ssize_t: c57. type
     definition instead of int.  See the earlier section *note PEP 353;
     Using ssize_t as the index type: 161f. for a discussion of this
     change.

   * The design of the bytecode compiler has changed a great deal, no
     longer generating bytecode by traversing the parse tree.  Instead
     the parse tree is converted to an abstract syntax tree (or AST),
     and it is the abstract syntax tree that’s traversed to produce the
     bytecode.

     It’s possible for Python code to obtain AST objects by using the
     *note compile(): 4b2. built-in and specifying ‘_ast.PyCF_ONLY_AST’
     as the value of the 'flags' parameter:

          from _ast import PyCF_ONLY_AST
          ast = compile("""a=0
          for i in range(10):
              a += i
          """, "<string>", 'exec', PyCF_ONLY_AST)

          assignment = ast.body[0]
          for_loop = ast.body[1]

     No official documentation has been written for the AST code yet,
     but PEP 339(3) discusses the design.  To start learning about the
     code, read the definition of the various AST nodes in
     ‘Parser/Python.asdl’.  A Python script reads this file and
     generates a set of C structure definitions in
     ‘Include/Python-ast.h’.  The ‘PyParser_ASTFromString()’ and
     ‘PyParser_ASTFromFile()’, defined in ‘Include/pythonrun.h’, take
     Python source as input and return the root of an AST representing
     the contents.  This AST can then be turned into a code object by
     ‘PyAST_Compile()’.  For more information, read the source code, and
     then ask questions on python-dev.

     The AST code was developed under Jeremy Hylton’s management, and
     implemented by (in alphabetical order) Brett Cannon, Nick Coghlan,
     Grant Edwards, John Ehresman, Kurt Kaiser, Neal Norwitz, Tim
     Peters, Armin Rigo, and Neil Schemenauer, plus the participants in
     a number of AST sprints at conferences such as PyCon.

   * Evan Jones’s patch to obmalloc, first described in a talk at PyCon
     DC 2005, was applied.  Python 2.4 allocated small objects in
     256K-sized arenas, but never freed arenas.  With this patch, Python
     will free arenas when they’re empty.  The net effect is that on
     some platforms, when you allocate many objects, Python’s memory
     usage may actually drop when you delete them and the memory may be
     returned to the operating system.  (Implemented by Evan Jones, and
     reworked by Tim Peters.)

     Note that this change means extension modules must be more careful
     when allocating memory.  Python’s API has many different functions
     for allocating memory that are grouped into families.  For example,
     *note PyMem_Malloc(): e62, *note PyMem_Realloc(): 1234, and *note
     PyMem_Free(): 1649. are one family that allocates raw memory, while
     *note PyObject_Malloc(): e64, *note PyObject_Realloc(): 164a, and
     *note PyObject_Free(): e61. are another family that’s supposed to
     be used for creating Python objects.

     Previously these different families all reduced to the platform’s
     ‘malloc()’ and ‘free()’ functions.  This meant it didn’t matter if
     you got things wrong and allocated memory with the ‘PyMem’ function
     but freed it with the ‘PyObject’ function.  With 2.5’s changes to
     obmalloc, these families now do different things and mismatches
     will probably result in a segfault.  You should carefully test your
     C extension modules with Python 2.5.

   * The built-in set types now have an official C API. Call *note
     PySet_New(): 164b. and *note PyFrozenSet_New(): 164c. to create a
     new set, *note PySet_Add(): 164d. and *note PySet_Discard(): 164e.
     to add and remove elements, and *note PySet_Contains(): 164f. and
     *note PySet_Size(): 1650. to examine the set’s state.  (Contributed
     by Raymond Hettinger.)

   * C code can now obtain information about the exact revision of the
     Python interpreter by calling the *note Py_GetBuildInfo(): 1639.
     function that returns a string of build information like this:
     ‘"trunk:45355:45356M, Apr 13 2006, 07:42:19"’.  (Contributed by
     Barry Warsaw.)

   * Two new macros can be used to indicate C functions that are local
     to the current file so that a faster calling convention can be
     used.  *note Py_LOCAL: 1651. declares the function as returning a
     value of the specified 'type' and uses a fast-calling qualifier.
     *note Py_LOCAL_INLINE: 1652. does the same thing and also requests
     the function be inlined.  If macro ‘PY_LOCAL_AGGRESSIVE’ is defined
     before ‘python.h’ is included, a set of more aggressive
     optimizations are enabled for the module; you should benchmark the
     results to find out if these optimizations actually make the code
     faster.  (Contributed by Fredrik Lundh at the NeedForSpeed sprint.)

   * ‘PyErr_NewException(name, base, dict)’ can now accept a tuple of
     base classes as its 'base' argument.  (Contributed by Georg
     Brandl.)

   * The ‘PyErr_Warn()’ function for issuing warnings is now deprecated
     in favour of ‘PyErr_WarnEx(category, message, stacklevel)’ which
     lets you specify the number of stack frames separating this
     function and the caller.  A 'stacklevel' of 1 is the function
     calling *note PyErr_WarnEx(): 1653, 2 is the function above that,
     and so forth.  (Added by Neal Norwitz.)

   * The CPython interpreter is still written in C, but the code can now
     be compiled with a C++ compiler without errors.  (Implemented by
     Anthony Baxter, Martin von Löwis, Skip Montanaro.)

   * The ‘PyRange_New()’ function was removed.  It was never documented,
     never used in the core code, and had dangerously lax error
     checking.  In the unlikely case that your extensions were using it,
     you can replace it by something like the following:

          range = PyObject_CallFunction((PyObject*) &PyRange_Type, "lll",
                                        start, stop, step);

* Menu:

* Port-Specific Changes::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0347/

   (2) https://peps.python.org/pep-0353/

   (3) https://peps.python.org/pep-0339/


File: python.info,  Node: Port-Specific Changes,  Up: Build and C API Changes<10>

1.18.14.1 Port-Specific Changes
...............................

   * MacOS X (10.3 and higher): dynamic loading of modules now uses the
     ‘dlopen()’ function instead of MacOS-specific functions.

   * MacOS X: an ‘--enable-universalsdk’ switch was added to the
     ‘configure’ script that compiles the interpreter as a universal
     binary able to run on both PowerPC and Intel processors.
     (Contributed by Ronald Oussoren; bpo-2573(1).)

   * Windows: ‘.dll’ is no longer supported as a filename extension for
     extension modules.  ‘.pyd’ is now the only filename extension that
     will be searched for.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=2573


File: python.info,  Node: Porting to Python 2 5,  Next: Acknowledgements<3>,  Prev: Build and C API Changes<10>,  Up: What’s New in Python 2 5

1.18.15 Porting to Python 2.5
-----------------------------

This section lists previously described changes that may require changes
to your code:

   * ASCII is now the default encoding for modules.  It’s now a syntax
     error if a module contains string literals with 8-bit characters
     but doesn’t have an encoding declaration.  In Python 2.4 this
     triggered a warning, not a syntax error.

   * Previously, the ‘gi_frame’ attribute of a generator was always a
     frame object.  Because of the PEP 342(1) changes described in
     section *note PEP 342; New Generator Features: 160b, it’s now
     possible for ‘gi_frame’ to be ‘None’.

   * A new warning, *note UnicodeWarning: 162b, is triggered when you
     attempt to compare a Unicode string and an 8-bit string that can’t
     be converted to Unicode using the default ASCII encoding.
     Previously such comparisons would raise a *note UnicodeDecodeError:
     c0a. exception.

   * Library: the *note csv: 2d. module is now stricter about multi-line
     quoted fields.  If your files contain newlines embedded within
     fields, the input should be split into lines in a manner which
     preserves the newline characters.

   * Library: the *note locale: 8a. module’s *note format(): 199.
     function’s would previously accept any string as long as no more
     than one %char specifier appeared.  In Python 2.5, the argument
     must be exactly one %char specifier with no surrounding text.

   * Library: The *note pickle: ab. and ‘cPickle’ modules no longer
     accept a return value of ‘None’ from the *note __reduce__(): bc8.
     method; the method must return a tuple of arguments instead.  The
     modules also no longer accept the deprecated 'bin' keyword
     parameter.

   * Library: The *note SimpleXMLRPCServer: 135. and *note
     DocXMLRPCServer: 135. classes now have a ‘rpc_paths’ attribute that
     constrains XML-RPC operations to a limited set of URL paths; the
     default is to allow only ‘'/'’ and ‘'/RPC2'’.  Setting ‘rpc_paths’
     to ‘None’ or an empty tuple disables this path checking.

   * C API: Many functions now use *note Py_ssize_t: c57. instead of int
     to allow processing more data on 64-bit machines.  Extension code
     may need to make the same change to avoid warnings and to support
     64-bit machines.  See the earlier section *note PEP 353; Using
     ssize_t as the index type: 161f. for a discussion of this change.

   * C API: The obmalloc changes mean that you must be careful to not
     mix usage of the ‘PyMem_*’ and ‘PyObject_*’ families of functions.
     Memory allocated with one family’s ‘*_Malloc’ must be freed with
     the corresponding family’s ‘*_Free’ function.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0342/


File: python.info,  Node: Acknowledgements<3>,  Prev: Porting to Python 2 5,  Up: What’s New in Python 2 5

1.18.16 Acknowledgements
------------------------

The author would like to thank the following people for offering
suggestions, corrections and assistance with various drafts of this
article: Georg Brandl, Nick Coghlan, Phillip J. Eby, Lars Gustäbel,
Raymond Hettinger, Ralf W. Grosse-Kunstleve, Kent Johnson, Iain Lowe,
Martin von Löwis, Fredrik Lundh, Andrew McNamara, Skip Montanaro,
Gustavo Niemeyer, Paul Prescod, James Pryor, Mike Rovner, Scott Weikart,
Barry Warsaw, Thomas Wouters.


File: python.info,  Node: What’s New in Python 2 4,  Next: What’s New in Python 2 3,  Prev: What’s New in Python 2 5,  Up: Novità in Python

1.19 What’s New in Python 2.4
=============================


Author: A.M. Kuchling

This article explains the new features in Python 2.4.1, released on
March 30, 2005.

Python 2.4 is a medium-sized release.  It doesn’t introduce as many
changes as the radical Python 2.2, but introduces more features than the
conservative 2.3 release.  The most significant new language features
are function decorators and generator expressions; most other changes
are to the standard library.

According to the CVS change logs, there were 481 patches applied and 502
bugs fixed between Python 2.3 and 2.4.  Both figures are likely to be
underestimates.

This article doesn’t attempt to provide a complete specification of
every single new feature, but instead provides a brief introduction to
each feature.  For full details, you should refer to the documentation
for Python 2.4, such as the Python Library Reference and the Python
Reference Manual.  Often you will be referred to the PEP for a
particular new feature for explanations of the implementation and design
rationale.

* Menu:

* PEP 218; Built-In Set Objects: PEP 218 Built-In Set Objects.
* PEP 237; Unifying Long Integers and Integers: PEP 237 Unifying Long Integers and Integers.
* PEP 289; Generator Expressions: PEP 289 Generator Expressions.
* PEP 292; Simpler String Substitutions: PEP 292 Simpler String Substitutions.
* PEP 318; Decorators for Functions and Methods: PEP 318 Decorators for Functions and Methods.
* PEP 322; Reverse Iteration: PEP 322 Reverse Iteration.
* PEP 324; New subprocess Module: PEP 324 New subprocess Module.
* PEP 327; Decimal Data Type: PEP 327 Decimal Data Type.
* PEP 328; Multi-line Imports: PEP 328 Multi-line Imports.
* PEP 331; Locale-Independent Float/String Conversions: PEP 331 Locale-Independent Float/String Conversions.
* Other Language Changes: Other Language Changes<16>.
* New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<3>.
* Build and C API Changes: Build and C API Changes<11>.
* Porting to Python 2.4: Porting to Python 2 4.
* Acknowledgements: Acknowledgements<4>.


File: python.info,  Node: PEP 218 Built-In Set Objects,  Next: PEP 237 Unifying Long Integers and Integers,  Up: What’s New in Python 2 4

1.19.1 PEP 218: Built-In Set Objects
------------------------------------

Python 2.3 introduced the ‘sets’ module.  C implementations of set data
types have now been added to the Python core as two new built-in types,
‘set(iterable)’ and ‘frozenset(iterable)’.  They provide high speed
operations for membership testing, for eliminating duplicates from
sequences, and for mathematical operations like unions, intersections,
differences, and symmetric differences.

     >>> a = set('abracadabra')              # form a set from a string
     >>> 'z' in a                            # fast membership testing
     False
     >>> a                                   # unique letters in a
     set(['a', 'r', 'b', 'c', 'd'])
     >>> ''.join(a)                          # convert back into a string
     'arbcd'

     >>> b = set('alacazam')                 # form a second set
     >>> a - b                               # letters in a but not in b
     set(['r', 'd', 'b'])
     >>> a | b                               # letters in either a or b
     set(['a', 'c', 'r', 'd', 'b', 'm', 'z', 'l'])
     >>> a & b                               # letters in both a and b
     set(['a', 'c'])
     >>> a ^ b                               # letters in a or b but not both
     set(['r', 'd', 'b', 'm', 'z', 'l'])

     >>> a.add('z')                          # add a new element
     >>> a.update('wxy')                     # add multiple new elements
     >>> a
     set(['a', 'c', 'b', 'd', 'r', 'w', 'y', 'x', 'z'])
     >>> a.remove('x')                       # take one element out
     >>> a
     set(['a', 'c', 'b', 'd', 'r', 'w', 'y', 'z'])

The *note frozenset(): 7f3. type is an immutable version of *note set():
184.  Since it is immutable and hashable, it may be used as a dictionary
key or as a member of another set.

The ‘sets’ module remains in the standard library, and may be useful if
you wish to subclass the ‘Set’ or ‘ImmutableSet’ classes.  There are
currently no plans to deprecate the module.

Vedi anche
..........

PEP 218(1) - Adding a Built-In Set Object Type

     Originally proposed by Greg Wilson and ultimately implemented by
     Raymond Hettinger.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0218/


File: python.info,  Node: PEP 237 Unifying Long Integers and Integers,  Next: PEP 289 Generator Expressions,  Prev: PEP 218 Built-In Set Objects,  Up: What’s New in Python 2 4

1.19.2 PEP 237: Unifying Long Integers and Integers
---------------------------------------------------

The lengthy transition process for this PEP, begun in Python 2.2, takes
another step forward in Python 2.4.  In 2.3, certain integer operations
that would behave differently after int/long unification triggered *note
FutureWarning: 659. warnings and returned values limited to 32 or 64
bits (depending on your platform).  In 2.4, these expressions no longer
produce a warning and instead produce a different result that’s usually
a long integer.

The problematic expressions are primarily left shifts and lengthy
hexadecimal and octal constants.  For example, ‘2 << 32’ results in a
warning in 2.3, evaluating to 0 on 32-bit platforms.  In Python 2.4,
this expression now returns the correct answer, 8589934592.

Vedi anche
..........

PEP 237(1) - Unifying Long Integers and Integers

     Original PEP written by Moshe Zadka and GvR. The changes for 2.4
     were implemented by Kalle Svensson.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0237/


File: python.info,  Node: PEP 289 Generator Expressions,  Next: PEP 292 Simpler String Substitutions,  Prev: PEP 237 Unifying Long Integers and Integers,  Up: What’s New in Python 2 4

1.19.3 PEP 289: Generator Expressions
-------------------------------------

The iterator feature introduced in Python 2.2 and the *note itertools:
85. module make it easier to write programs that loop through large data
sets without having the entire data set in memory at one time.  List
comprehensions don’t fit into this picture very well because they
produce a Python list object containing all of the items.  This
unavoidably pulls all of the objects into memory, which can be a problem
if your data set is very large.  When trying to write a functionally
styled program, it would be natural to write something like:

     links = [link for link in get_all_links() if not link.followed]
     for link in links:
         ...

instead of

     for link in get_all_links():
         if link.followed:
             continue
         ...

The first form is more concise and perhaps more readable, but if you’re
dealing with a large number of link objects you’d have to write the
second form to avoid having all link objects in memory at the same time.

Generator expressions work similarly to list comprehensions but don’t
materialize the entire list; instead they create a generator that will
return elements one by one.  The above example could be written as:

     links = (link for link in get_all_links() if not link.followed)
     for link in links:
         ...

Generator expressions always have to be written inside parentheses, as
in the above example.  The parentheses signalling a function call also
count, so if you want to create an iterator that will be immediately
passed to a function you could write:

     print sum(obj.count for obj in list_all_objects())

Generator expressions differ from list comprehensions in various small
ways.  Most notably, the loop variable ('obj' in the above example) is
not accessible outside of the generator expression.  List comprehensions
leave the variable assigned to its last value; future versions of Python
will change this, making list comprehensions match generator expressions
in this respect.

Vedi anche
..........

PEP 289(1) - Generator Expressions

     Proposed by Raymond Hettinger and implemented by Jiwon Seo with
     early efforts steered by Hye-Shik Chang.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0289/


File: python.info,  Node: PEP 292 Simpler String Substitutions,  Next: PEP 318 Decorators for Functions and Methods,  Prev: PEP 289 Generator Expressions,  Up: What’s New in Python 2 4

1.19.4 PEP 292: Simpler String Substitutions
--------------------------------------------

Some new classes in the standard library provide an alternative
mechanism for substituting variables into strings; this style of
substitution may be better for applications where untrained users need
to edit templates.

The usual way of substituting variables by name is the ‘%’ operator:

     >>> '%(page)i: %(title)s' % {'page':2, 'title': 'The Best of Times'}
     '2: The Best of Times'

When writing the template string, it can be easy to forget the ‘i’ or
‘s’ after the closing parenthesis.  This isn’t a big problem if the
template is in a Python module, because you run the code, get an
«Unsupported format character» *note ValueError: 2ec, and fix the
problem.  However, consider an application such as Mailman where
template strings or translations are being edited by users who aren’t
aware of the Python language.  The format string’s syntax is complicated
to explain to such users, and if they make a mistake, it’s difficult to
provide helpful feedback to them.

PEP 292 adds a ‘Template’ class to the *note string: d8. module that
uses ‘$’ to indicate a substitution:

     >>> import string
     >>> t = string.Template('$page: $title')
     >>> t.substitute({'page':2, 'title': 'The Best of Times'})
     '2: The Best of Times'

If a key is missing from the dictionary, the ‘substitute()’ method will
raise a *note KeyError: 5e7.  There’s also a ‘safe_substitute()’ method
that ignores missing keys:

     >>> t = string.Template('$page: $title')
     >>> t.safe_substitute({'page':3})
     '3: $title'

Vedi anche
..........

PEP 292(1) - Simpler String Substitutions

     Written and implemented by Barry Warsaw.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0292/


File: python.info,  Node: PEP 318 Decorators for Functions and Methods,  Next: PEP 322 Reverse Iteration,  Prev: PEP 292 Simpler String Substitutions,  Up: What’s New in Python 2 4

1.19.5 PEP 318: Decorators for Functions and Methods
----------------------------------------------------

Python 2.2 extended Python’s object model by adding static methods and
class methods, but it didn’t extend Python’s syntax to provide any new
way of defining static or class methods.  Instead, you had to write a
*note def: 1661. statement in the usual way, and pass the resulting
method to a *note staticmethod(): 453. or *note classmethod(): 48f.
function that would wrap up the function as a method of the new type.
Your code would look like this:

     class C:
        def meth (cls):
            ...

        meth = classmethod(meth)   # Rebind name to wrapped-up class method

If the method was very long, it would be easy to miss or forget the
*note classmethod(): 48f. invocation after the function body.

The intention was always to add some syntax to make such definitions
more readable, but at the time of 2.2’s release a good syntax was not
obvious.  Today a good syntax 'still' isn’t obvious but users are asking
for easier access to the feature; a new syntactic feature has been added
to meet this need.

The new feature is called «function decorators».  The name comes from
the idea that *note classmethod(): 48f, *note staticmethod(): 453, and
friends are storing additional information on a function object; they’re
'decorating' functions with more details.

The notation borrows from Java and uses the ‘'@'’ character as an
indicator.  Using the new syntax, the example above would be written:

     class C:

        @classmethod
        def meth (cls):
            ...

The ‘@classmethod’ is shorthand for the ‘meth=classmethod(meth)’
assignment.  More generally, if you have the following:

     @A
     @B
     @C
     def f ():
         ...

It’s equivalent to the following pre-decorator code:

     def f(): ...
     f = A(B(C(f)))

Decorators must come on the line before a function definition, one
decorator per line, and can’t be on the same line as the def statement,
meaning that ‘@A def f(): ...’ is illegal.  You can only decorate
function definitions, either at the module level or inside a class; you
can’t decorate class definitions.

A decorator is just a function that takes the function to be decorated
as an argument and returns either the same function or some new object.
The return value of the decorator need not be callable (though it
typically is), unless further decorators will be applied to the result.
It’s easy to write your own decorators.  The following simple example
just sets an attribute on the function object:

     >>> def deco(func):
     ...    func.attr = 'decorated'
     ...    return func
     ...
     >>> @deco
     ... def f(): pass
     ...
     >>> f
     <function f at 0x402ef0d4>
     >>> f.attr
     'decorated'
     >>>

As a slightly more realistic example, the following decorator checks
that the supplied argument is an integer:

     def require_int (func):
         def wrapper (arg):
             assert isinstance(arg, int)
             return func(arg)

         return wrapper

     @require_int
     def p1 (arg):
         print arg

     @require_int
     def p2(arg):
         print arg*2

An example in PEP 318(1) contains a fancier version of this idea that
lets you both specify the required type and check the returned type.

Decorator functions can take arguments.  If arguments are supplied, your
decorator function is called with only those arguments and must return a
new decorator function; this function must take a single function and
return a function, as previously described.  In other words, ‘@A @B
@C(args)’ becomes:

     def f(): ...
     _deco = C(args)
     f = A(B(_deco(f)))

Getting this right can be slightly brain-bending, but it’s not too
difficult.

A small related change makes the *note func_name: 14dc. attribute of
functions writable.  This attribute is used to display function names in
tracebacks, so decorators should change the name of any new function
that’s constructed and returned.

Vedi anche
..........

PEP 318(2) - Decorators for Functions, Methods and Classes

     Written by Kevin D. Smith, Jim Jewett, and Skip Montanaro.  Several
     people wrote patches implementing function decorators, but the one
     that was actually checked in was patch #979728, written by Mark
     Russell.

‘https://wiki.python.org/moin/PythonDecoratorLibrary’

     This Wiki page contains several examples of decorators.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0318/

   (2) https://peps.python.org/pep-0318/


File: python.info,  Node: PEP 322 Reverse Iteration,  Next: PEP 324 New subprocess Module,  Prev: PEP 318 Decorators for Functions and Methods,  Up: What’s New in Python 2 4

1.19.6 PEP 322: Reverse Iteration
---------------------------------

A new built-in function, ‘reversed(seq)’, takes a sequence and returns
an iterator that loops over the elements of the sequence in reverse
order.

     >>> for i in reversed(xrange(1,4)):
     ...    print i
     ...
     3
     2
     1

Compared to extended slicing, such as ‘range(1,4)[::-1]’, *note
reversed(): a67. is easier to read, runs faster, and uses substantially
less memory.

Note that *note reversed(): a67. only accepts sequences, not arbitrary
iterators.  If you want to reverse an iterator, first convert it to a
list with *note list(): 24d.

     >>> input = open('/etc/passwd', 'r')
     >>> for line in reversed(list(input)):
     ...   print line
     ...
     root:*:0:0:System Administrator:/var/root:/bin/tcsh
       ...

Vedi anche
..........

PEP 322(1) - Reverse Iteration

     Written and implemented by Raymond Hettinger.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0322/


File: python.info,  Node: PEP 324 New subprocess Module,  Next: PEP 327 Decimal Data Type,  Prev: PEP 322 Reverse Iteration,  Up: What’s New in Python 2 4

1.19.7 PEP 324: New subprocess Module
-------------------------------------

The standard library provides a number of ways to execute a subprocess,
offering different features and different levels of complexity.
‘os.system(command)’ is easy to use, but slow (it runs a shell process
which executes the command) and dangerous (you have to be careful about
escaping the shell’s metacharacters).  The ‘popen2’ module offers
classes that can capture standard output and standard error from the
subprocess, but the naming is confusing.  The *note subprocess: dc.
module cleans this up, providing a unified interface that offers all the
features you might need.

Instead of ‘popen2’’s collection of classes, *note subprocess: dc.
contains a single class called *note subprocess.Popen: 4b8. whose
constructor supports a number of different keyword arguments.

     class Popen(args, bufsize=0, executable=None,
                 stdin=None, stdout=None, stderr=None,
                 preexec_fn=None, close_fds=False, shell=False,
                 cwd=None, env=None, universal_newlines=False,
                 startupinfo=None, creationflags=0):

'args' is commonly a sequence of strings that will be the arguments to
the program executed as the subprocess.  (If the 'shell' argument is
true, 'args' can be a string which will then be passed on to the shell
for interpretation, just as *note os.system(): 1664. does.)

'stdin', 'stdout', and 'stderr' specify what the subprocess’s input,
output, and error streams will be.  You can provide a file object or a
file descriptor, or you can use the constant ‘subprocess.PIPE’ to create
a pipe between the subprocess and the parent.

The constructor has a number of handy options:

   * 'close_fds' requests that all file descriptors be closed before
     running the subprocess.

   * 'cwd' specifies the working directory in which the subprocess will
     be executed (defaulting to whatever the parent’s working directory
     is).

   * 'env' is a dictionary specifying environment variables.

   * 'preexec_fn' is a function that gets called before the child is
     started.

   * 'universal_newlines' opens the child’s input and output using
     Python’s *note universal newlines: f37. feature.

Once you’ve created the ‘Popen’ instance, you can call its ‘wait()’
method to pause until the subprocess has exited, ‘poll()’ to check if
it’s exited without pausing, or ‘communicate(data)’ to send the string
'data' to the subprocess’s standard input.  ‘communicate(data)’ then
reads any data that the subprocess has sent to its standard output or
standard error, returning a tuple ‘(stdout_data, stderr_data)’.

‘call()’ is a shortcut that passes its arguments along to the ‘Popen’
constructor, waits for the command to complete, and returns the status
code of the subprocess.  It can serve as a safer analog to *note
os.system(): 1664.:

     sts = subprocess.call(['dpkg', '-i', '/tmp/new-package.deb'])
     if sts == 0:
         # Success
         ...
     else:
         # dpkg returned an error
         ...

The command is invoked without use of the shell.  If you really do want
to use the shell, you can add ‘shell=True’ as a keyword argument and
provide a string instead of a sequence:

     sts = subprocess.call('dpkg -i /tmp/new-package.deb', shell=True)

The PEP takes various examples of shell and Python code and shows how
they’d be translated into Python code that uses *note subprocess: dc.
Reading this section of the PEP is highly recommended.

Vedi anche
..........

PEP 324(1) - subprocess - New process module

     Written and implemented by Peter Åstrand, with assistance from
     Fredrik Lundh and others.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0324/


File: python.info,  Node: PEP 327 Decimal Data Type,  Next: PEP 328 Multi-line Imports,  Prev: PEP 324 New subprocess Module,  Up: What’s New in Python 2 4

1.19.8 PEP 327: Decimal Data Type
---------------------------------

Python has always supported floating-point (FP) numbers, based on the
underlying C double type, as a data type.  However, while most
programming languages provide a floating-point type, many people (even
programmers) are unaware that floating-point numbers don’t represent
certain decimal fractions accurately.  The new ‘Decimal’ type can
represent these fractions accurately, up to a user-specified precision
limit.

* Menu:

* Why is Decimal needed?::
* The Decimal type::
* The Context type::


File: python.info,  Node: Why is Decimal needed?,  Next: The Decimal type,  Up: PEP 327 Decimal Data Type

1.19.8.1 Why is Decimal needed?
...............................

The limitations arise from the representation used for floating-point
numbers.  FP numbers are made up of three components:

   * The sign, which is positive or negative.

   * The mantissa, which is a single-digit binary number followed by a
     fractional part.  For example, ‘1.01’ in base-2 notation is ‘1 +
     0/2 + 1/4’, or 1.25 in decimal notation.

   * The exponent, which tells where the decimal point is located in the
     number represented.

For example, the number 1.25 has positive sign, a mantissa value of 1.01
(in binary), and an exponent of 0 (the decimal point doesn’t need to be
shifted).  The number 5 has the same sign and mantissa, but the exponent
is 2 because the mantissa is multiplied by 4 (2 to the power of the
exponent 2); 1.25 * 4 equals 5.

Modern systems usually provide floating-point support that conforms to a
standard called IEEE 754.  C’s double type is usually implemented as a
64-bit IEEE 754 number, which uses 52 bits of space for the mantissa.
This means that numbers can only be specified to 52 bits of precision.
If you’re trying to represent numbers whose expansion repeats endlessly,
the expansion is cut off after 52 bits.  Unfortunately, most software
needs to produce output in base 10, and common fractions in base 10 are
often repeating decimals in binary.  For example, 1.1 decimal is binary
‘1.0001100110011 ...’; .1 = 1/16 + 1/32 + 1/256 plus an infinite number
of additional terms.  IEEE 754 has to chop off that infinitely repeated
decimal after 52 digits, so the representation is slightly inaccurate.

Sometimes you can see this inaccuracy when the number is printed:

     >>> 1.1
     1.1000000000000001

The inaccuracy isn’t always visible when you print the number because
the FP-to-decimal-string conversion is provided by the C library, and
most C libraries try to produce sensible output.  Even if it’s not
displayed, however, the inaccuracy is still there and subsequent
operations can magnify the error.

For many applications this doesn’t matter.  If I’m plotting points and
displaying them on my monitor, the difference between 1.1 and
1.1000000000000001 is too small to be visible.  Reports often limit
output to a certain number of decimal places, and if you round the
number to two or three or even eight decimal places, the error is never
apparent.  However, for applications where it does matter, it’s a lot of
work to implement your own custom arithmetic routines.

Hence, the ‘Decimal’ type was created.


File: python.info,  Node: The Decimal type,  Next: The Context type,  Prev: Why is Decimal needed?,  Up: PEP 327 Decimal Data Type

1.19.8.2 The ‘Decimal’ type
...........................

A new module, *note decimal: 3a, was added to Python’s standard library.
It contains two classes, ‘Decimal’ and ‘Context’.  ‘Decimal’ instances
represent numbers, and ‘Context’ instances are used to wrap up various
settings such as the precision and default rounding mode.

‘Decimal’ instances are immutable, like regular Python integers and FP
numbers; once it’s been created, you can’t change the value an instance
represents.  ‘Decimal’ instances can be created from integers or
strings:

     >>> import decimal
     >>> decimal.Decimal(1972)
     Decimal("1972")
     >>> decimal.Decimal("1.1")
     Decimal("1.1")

You can also provide tuples containing the sign, the mantissa
represented as a tuple of decimal digits, and the exponent:

     >>> decimal.Decimal((1, (1, 4, 7, 5), -2))
     Decimal("-14.75")

Cautionary note: the sign bit is a Boolean value, so 0 is positive and 1
is negative.

Converting from floating-point numbers poses a bit of a problem: should
the FP number representing 1.1 turn into the decimal number for exactly
1.1, or for 1.1 plus whatever inaccuracies are introduced?  The decision
was to dodge the issue and leave such a conversion out of the API.
Instead, you should convert the floating-point number into a string
using the desired precision and pass the string to the ‘Decimal’
constructor:

     >>> f = 1.1
     >>> decimal.Decimal(str(f))
     Decimal("1.1")
     >>> decimal.Decimal('%.12f' % f)
     Decimal("1.100000000000")

Once you have ‘Decimal’ instances, you can perform the usual
mathematical operations on them.  One limitation: exponentiation
requires an integer exponent:

     >>> a = decimal.Decimal('35.72')
     >>> b = decimal.Decimal('1.73')
     >>> a+b
     Decimal("37.45")
     >>> a-b
     Decimal("33.99")
     >>> a*b
     Decimal("61.7956")
     >>> a/b
     Decimal("20.64739884393063583815028902")
     >>> a ** 2
     Decimal("1275.9184")
     >>> a**b
     Traceback (most recent call last):
       ...
     decimal.InvalidOperation: x ** (non-integer)

You can combine ‘Decimal’ instances with integers, but not with
floating-point numbers:

     >>> a + 4
     Decimal("39.72")
     >>> a + 4.5
     Traceback (most recent call last):
       ...
     TypeError: You can interact Decimal only with int, long or Decimal data types.
     >>>

‘Decimal’ numbers can be used with the *note math: 92. and *note cmath:
19. modules, but note that they’ll be immediately converted to
floating-point numbers before the operation is performed, resulting in a
possible loss of precision and accuracy.  You’ll also get back a regular
floating-point number and not a ‘Decimal’.

     >>> import math, cmath
     >>> d = decimal.Decimal('123456789012.345')
     >>> math.sqrt(d)
     351364.18288201344
     >>> cmath.sqrt(-d)
     351364.18288201344j

‘Decimal’ instances have a ‘sqrt()’ method that returns a ‘Decimal’, but
if you need other things such as trigonometric functions you’ll have to
implement them.

     >>> d.sqrt()
     Decimal("351364.1828820134592177245001")


File: python.info,  Node: The Context type,  Prev: The Decimal type,  Up: PEP 327 Decimal Data Type

1.19.8.3 The ‘Context’ type
...........................

Instances of the ‘Context’ class encapsulate several settings for
decimal operations:

   * ‘prec’ is the precision, the number of decimal places.

   * ‘rounding’ specifies the rounding mode.  The *note decimal: 3a.
     module has constants for the various possibilities: ‘ROUND_DOWN’,
     ‘ROUND_CEILING’, ‘ROUND_HALF_EVEN’, and various others.

   * ‘traps’ is a dictionary specifying what happens on encountering
     certain error conditions: either an exception is raised or a value
     is returned.  Some examples of error conditions are division by
     zero, loss of precision, and overflow.

There’s a thread-local default context available by calling
‘getcontext()’; you can change the properties of this context to alter
the default precision, rounding, or trap handling.  The following
example shows the effect of changing the precision of the default
context:

     >>> decimal.getcontext().prec
     28
     >>> decimal.Decimal(1) / decimal.Decimal(7)
     Decimal("0.1428571428571428571428571429")
     >>> decimal.getcontext().prec = 9
     >>> decimal.Decimal(1) / decimal.Decimal(7)
     Decimal("0.142857143")

The default action for error conditions is selectable; the module can
either return a special value such as infinity or not-a-number, or
exceptions can be raised:

     >>> decimal.Decimal(1) / decimal.Decimal(0)
     Traceback (most recent call last):
       ...
     decimal.DivisionByZero: x / 0
     >>> decimal.getcontext().traps[decimal.DivisionByZero] = False
     >>> decimal.Decimal(1) / decimal.Decimal(0)
     Decimal("Infinity")
     >>>

The ‘Context’ instance also has various methods for formatting numbers
such as ‘to_eng_string()’ and ‘to_sci_string()’.

For more information, see the documentation for the *note decimal: 3a.
module, which includes a quick-start tutorial and a reference.

Vedi anche
..........

PEP 327(1) - Decimal Data Type

     Written by Facundo Batista and implemented by Facundo Batista, Eric
     Price, Raymond Hettinger, Aahz, and Tim Peters.

http://www.lahey.com/float.htm(2)

     The article uses Fortran code to illustrate many of the problems
     that floating-point inaccuracy can cause.

‘https://speleotrove.com/decimal/’

     A description of a decimal-based representation.  This
     representation is being proposed as a standard, and underlies the
     new Python decimal type.  Much of this material was written by Mike
     Cowlishaw, designer of the Rexx language.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0327/

   (2) 
https://web.archive.org/web/20230604072523/http://www.lahey.com/float.htm


File: python.info,  Node: PEP 328 Multi-line Imports,  Next: PEP 331 Locale-Independent Float/String Conversions,  Prev: PEP 327 Decimal Data Type,  Up: What’s New in Python 2 4

1.19.9 PEP 328: Multi-line Imports
----------------------------------

One language change is a small syntactic tweak aimed at making it easier
to import many names from a module.  In a ‘from module import names’
statement, 'names' is a sequence of names separated by commas.  If the
sequence is very long, you can either write multiple imports from the
same module, or you can use backslashes to escape the line endings like
this:

     from SimpleXMLRPCServer import SimpleXMLRPCServer,\
                 SimpleXMLRPCRequestHandler,\
                 CGIXMLRPCRequestHandler,\
                 resolve_dotted_attribute

The syntactic change in Python 2.4 simply allows putting the names
within parentheses.  Python ignores newlines within a parenthesized
expression, so the backslashes are no longer needed:

     from SimpleXMLRPCServer import (SimpleXMLRPCServer,
                                     SimpleXMLRPCRequestHandler,
                                     CGIXMLRPCRequestHandler,
                                     resolve_dotted_attribute)

The PEP also proposes that all *note import: 7f9. statements be absolute
imports, with a leading ‘.’ character to indicate a relative import.
This part of the PEP was not implemented for Python 2.4, but was
completed for Python 2.5.

Vedi anche
..........

PEP 328(1) - Imports: Multi-Line and Absolute/Relative

     Written by Aahz.  Multi-line imports were implemented by Dima
     Dorfman.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0328/


File: python.info,  Node: PEP 331 Locale-Independent Float/String Conversions,  Next: Other Language Changes<16>,  Prev: PEP 328 Multi-line Imports,  Up: What’s New in Python 2 4

1.19.10 PEP 331: Locale-Independent Float/String Conversions
------------------------------------------------------------

The *note locale: 8a. modules lets Python software select various
conversions and display conventions that are localized to a particular
country or language.  However, the module was careful to not change the
numeric locale because various functions in Python’s implementation
required that the numeric locale remain set to the ‘'C'’ locale.  Often
this was because the code was using the C library’s ‘atof()’ function.

Not setting the numeric locale caused trouble for extensions that used
third-party C libraries, however, because they wouldn’t have the correct
locale set.  The motivating example was GTK+, whose user interface
widgets weren’t displaying numbers in the current locale.

The solution described in the PEP is to add three new functions to the
Python API that perform ASCII-only conversions, ignoring the locale
setting:

   * ‘PyOS_ascii_strtod(str, ptr)’ and ‘PyOS_ascii_atof(str, ptr)’ both
     convert a string to a C double.

   * ‘PyOS_ascii_formatd(buffer, buf_len, format, d)’ converts a double
     to an ASCII string.

The code for these functions came from the GLib library
(https://developer-old.gnome.org/glib/2.26/(1)), whose developers kindly
relicensed the relevant functions and donated them to the Python
Software Foundation.  The *note locale: 8a. module can now change the
numeric locale, letting extensions such as GTK+ produce the correct
results.

Vedi anche
..........

PEP 331(2) - Locale-Independent Float/String Conversions

     Written by Christian R. Reis, and implemented by Gustavo Carneiro.

   ---------- Footnotes ----------

   (1) 
http://web.archive.org/web/20210306104320/https://developer.gnome.org/glib/2.26/

   (2) https://peps.python.org/pep-0331/


File: python.info,  Node: Other Language Changes<16>,  Next: New Improved and Deprecated Modules<3>,  Prev: PEP 331 Locale-Independent Float/String Conversions,  Up: What’s New in Python 2 4

1.19.11 Other Language Changes
------------------------------

Here are all of the changes that Python 2.4 makes to the core Python
language.

   * Decorators for functions and methods were added ( PEP 318(1)).

   * Built-in *note set(): 184. and *note frozenset(): 7f3. types were
     added ( PEP 218(2)).  Other new built-ins include the
     ‘reversed(seq)’ function ( PEP 322(3)).

   * Generator expressions were added ( PEP 289(4)).

   * Certain numeric expressions no longer return values restricted to
     32 or 64 bits ( PEP 237(5)).

   * You can now put parentheses around the list of names in a ‘from
     module import names’ statement ( PEP 328(6)).

   * The *note dict.update(): 166c. method now accepts the same argument
     forms as the *note dict: 183. constructor.  This includes any
     mapping, any iterable of key/value pairs, and keyword arguments.
     (Contributed by Raymond Hettinger.)

   * The string methods ‘ljust()’, ‘rjust()’, and ‘center()’ now take an
     optional argument for specifying a fill character other than a
     space.  (Contributed by Raymond Hettinger.)

   * Strings also gained an ‘rsplit()’ method that works like the
     ‘split()’ method but splits from the end of the string.
     (Contributed by Sean Reifschneider.)

          >>> 'www.python.org'.split('.', 1)
          ['www', 'python.org']
          'www.python.org'.rsplit('.', 1)
          ['www.python', 'org']

   * Three keyword parameters, 'cmp', 'key', and 'reverse', were added
     to the ‘sort()’ method of lists.  These parameters make some common
     usages of ‘sort()’ simpler.  All of these parameters are optional.

     For the 'cmp' parameter, the value should be a comparison function
     that takes two parameters and returns -1, 0, or +1 depending on how
     the parameters compare.  This function will then be used to sort
     the list.  Previously this was the only parameter that could be
     provided to ‘sort()’.

     'key' should be a single-parameter function that takes a list
     element and returns a comparison key for the element.  The list is
     then sorted using the comparison keys.  The following example sorts
     a list case-insensitively:

          >>> L = ['A', 'b', 'c', 'D']
          >>> L.sort()                 # Case-sensitive sort
          >>> L
          ['A', 'D', 'b', 'c']
          >>> # Using 'key' parameter to sort list
          >>> L.sort(key=lambda x: x.lower())
          >>> L
          ['A', 'b', 'c', 'D']
          >>> # Old-fashioned way
          >>> L.sort(cmp=lambda x,y: cmp(x.lower(), y.lower()))
          >>> L
          ['A', 'b', 'c', 'D']

     The last example, which uses the 'cmp' parameter, is the old way to
     perform a case-insensitive sort.  It works but is slower than using
     a 'key' parameter.  Using 'key' calls ‘lower()’ method once for
     each element in the list while using 'cmp' will call it twice for
     each comparison, so using 'key' saves on invocations of the
     ‘lower()’ method.

     For simple key functions and comparison functions, it is often
     possible to avoid a *note lambda: 14a5. expression by using an
     unbound method instead.  For example, the above case-insensitive
     sort is best written as:

          >>> L.sort(key=str.lower)
          >>> L
          ['A', 'b', 'c', 'D']

     Finally, the 'reverse' parameter takes a Boolean value.  If the
     value is true, the list will be sorted into reverse order.  Instead
     of ‘L.sort(); L.reverse()’, you can now write
     ‘L.sort(reverse=True)’.

     The results of sorting are now guaranteed to be stable.  This means
     that two entries with equal keys will be returned in the same order
     as they were input.  For example, you can sort a list of people by
     name, and then sort the list by age, resulting in a list sorted by
     age where people with the same age are in name-sorted order.

     (All changes to ‘sort()’ contributed by Raymond Hettinger.)

   * There is a new built-in function ‘sorted(iterable)’ that works like
     the in-place *note list.sort(): dca. method but can be used in
     expressions.  The differences are:

   * the input may be any iterable;

   * a newly formed copy is sorted, leaving the original intact; and

   * the expression returns the new sorted copy

          >>> L = [9,7,8,3,2,4,1,6,5]
          >>> [10+i for i in sorted(L)]       # usable in a list comprehension
          [11, 12, 13, 14, 15, 16, 17, 18, 19]
          >>> L                               # original is left unchanged
          [9,7,8,3,2,4,1,6,5]
          >>> sorted('Monty Python')          # any iterable may be an input
          [' ', 'M', 'P', 'h', 'n', 'n', 'o', 'o', 't', 't', 'y', 'y']

          >>> # List the contents of a dict sorted by key values
          >>> colormap = dict(red=1, blue=2, green=3, black=4, yellow=5)
          >>> for k, v in sorted(colormap.iteritems()):
          ...     print k, v
          ...
          black 4
          blue 2
          green 3
          red 1
          yellow 5

     (Contributed by Raymond Hettinger.)

   * Integer operations will no longer trigger an ‘OverflowWarning’.
     The ‘OverflowWarning’ warning will disappear in Python 2.5.

   * The interpreter gained a new switch, *note -m: 23c, that takes a
     name, searches for the corresponding module on ‘sys.path’, and runs
     the module as a script.  For example, you can now run the Python
     profiler with ‘python -m profile’.  (Contributed by Nick Coghlan.)

   * The ‘eval(expr, globals, locals)’ and ‘execfile(filename, globals,
     locals)’ functions and the ‘exec’ statement now accept any mapping
     type for the 'locals' parameter.  Previously this had to be a
     regular Python dictionary.  (Contributed by Raymond Hettinger.)

   * The *note zip(): 1a0. built-in function and ‘itertools.izip()’ now
     return an empty list if called with no arguments.  Previously they
     raised a *note TypeError: 198. exception.  This makes them more
     suitable for use with variable length argument lists:

          >>> def transpose(array):
          ...    return zip(*array)
          ...
          >>> transpose([(1,2,3), (4,5,6)])
          [(1, 4), (2, 5), (3, 6)]
          >>> transpose([])
          []

     (Contributed by Raymond Hettinger.)

   * Encountering a failure while importing a module no longer leaves a
     partially initialized module object in ‘sys.modules’.  The
     incomplete module object left behind would fool further imports of
     the same module into succeeding, leading to confusing errors.
     (Fixed by Tim Peters.)

   * *note None: 886. is now a constant; code that binds a new value to
     the name ‘None’ is now a syntax error.  (Contributed by Raymond
     Hettinger.)

* Menu:

* Optimizations: Optimizations<16>.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0318/

   (2) https://peps.python.org/pep-0218/

   (3) https://peps.python.org/pep-0322/

   (4) https://peps.python.org/pep-0289/

   (5) https://peps.python.org/pep-0237/

   (6) https://peps.python.org/pep-0328/


File: python.info,  Node: Optimizations<16>,  Up: Other Language Changes<16>

1.19.11.1 Optimizations
.......................

   * The inner loops for list and tuple slicing were optimized and now
     run about one-third faster.  The inner loops for dictionaries were
     also optimized, resulting in performance boosts for ‘keys()’,
     ‘values()’, ‘items()’, ‘iterkeys()’, ‘itervalues()’, and
     ‘iteritems()’.  (Contributed by Raymond Hettinger.)

   * The machinery for growing and shrinking lists was optimized for
     speed and for space efficiency.  Appending and popping from lists
     now runs faster due to more efficient code paths and less frequent
     use of the underlying system ‘realloc()’.  List comprehensions also
     benefit.  *note list.extend(): 602. was also optimized and no
     longer converts its argument into a temporary list before extending
     the base list.  (Contributed by Raymond Hettinger.)

   * *note list(): 24d, *note tuple(): 614, *note map(): 19f, *note
     filter(): a66, and *note zip(): 1a0. now run several times faster
     with non-sequence arguments that supply a ‘__len__()’ method.
     (Contributed by Raymond Hettinger.)

   * The methods ‘list.__getitem__()’, ‘dict.__getitem__()’, and
     ‘dict.__contains__()’ are now implemented as ‘method_descriptor’
     objects rather than ‘wrapper_descriptor’ objects.  This form of
     access doubles their performance and makes them more suitable for
     use as arguments to functionals: ‘map(mydict.__getitem__,
     keylist)’.  (Contributed by Raymond Hettinger.)

   * Added a new opcode, ‘LIST_APPEND’, that simplifies the generated
     bytecode for list comprehensions and speeds them up by about a
     third.  (Contributed by Raymond Hettinger.)

   * The peephole bytecode optimizer has been improved to produce
     shorter, faster bytecode; remarkably, the resulting bytecode is
     more readable.  (Enhanced by Raymond Hettinger.)

   * String concatenations in statements of the form ‘s = s + "abc"’ and
     ‘s += "abc"’ are now performed more efficiently in certain
     circumstances.  This optimization won’t be present in other Python
     implementations such as Jython, so you shouldn’t rely on it; using
     the ‘join()’ method of strings is still recommended when you want
     to efficiently glue a large number of strings together.
     (Contributed by Armin Rigo.)

The net result of the 2.4 optimizations is that Python 2.4 runs the
pystone benchmark around 5% faster than Python 2.3 and 35% faster than
Python 2.2.  (pystone is not a particularly good benchmark, but it’s the
most commonly used measurement of Python’s performance.  Your own
applications may show greater or smaller benefits from Python 2.4.)


File: python.info,  Node: New Improved and Deprecated Modules<3>,  Next: Build and C API Changes<11>,  Prev: Other Language Changes<16>,  Up: What’s New in Python 2 4

1.19.12 New, Improved, and Deprecated Modules
---------------------------------------------

As usual, Python’s standard library received a number of enhancements
and bug fixes.  Here’s a partial list of the most notable changes,
sorted alphabetically by module name.  Consult the ‘Misc/NEWS’ file in
the source tree for a more complete list of changes, or look through the
CVS logs for all the details.

   * The ‘asyncore’ module’s ‘loop()’ function now has a 'count'
     parameter that lets you perform a limited number of passes through
     the polling loop.  The default is still to loop forever.

   * The *note base64: f. module now has more complete RFC 3548(1)
     support for Base64, Base32, and Base16 encoding and decoding,
     including optional case folding and optional alternative alphabets.
     (Contributed by Barry Warsaw.)

   * The *note bisect: 12. module now has an underlying C implementation
     for improved performance.  (Contributed by Dmitry Vasiliev.)

   * The CJKCodecs collections of East Asian codecs, maintained by
     Hye-Shik Chang, was integrated into 2.4.  The new encodings are:

   * Chinese (PRC): gb2312, gbk, gb18030, big5hkscs, hz

   * Chinese (ROC): big5, cp950

   * 
     Japanese: cp932, euc-jis-2004, euc-jp, euc-jisx0213, iso-2022-jp,

          iso-2022-jp-1, iso-2022-jp-2, iso-2022-jp-3, iso-2022-jp-ext,
          iso-2022-jp-2004, shift-jis, shift-jisx0213, shift-jis-2004

   * Korean: cp949, euc-kr, johab, iso-2022-kr

   * Some other new encodings were added: HP Roman8, ISO_8859-11,
     ISO_8859-16, PCTP-154, and TIS-620.

   * The UTF-8 and UTF-16 codecs now cope better with receiving partial
     input.  Previously the ‘StreamReader’ class would try to read more
     data, making it impossible to resume decoding from the stream.  The
     ‘read()’ method will now return as much data as it can and future
     calls will resume decoding where previous ones left off.
     (Implemented by Walter Dörwald.)

   * There is a new *note collections: 1e. module for various
     specialized collection datatypes.  Currently it contains just one
     type, ‘deque’, a double-ended queue that supports efficiently
     adding and removing elements from either end:

          >>> from collections import deque
          >>> d = deque('ghi')        # make a new deque with three items
          >>> d.append('j')           # add a new entry to the right side
          >>> d.appendleft('f')       # add a new entry to the left side
          >>> d                       # show the representation of the deque
          deque(['f', 'g', 'h', 'i', 'j'])
          >>> d.pop()                 # return and remove the rightmost item
          'j'
          >>> d.popleft()             # return and remove the leftmost item
          'f'
          >>> list(d)                 # list the contents of the deque
          ['g', 'h', 'i']
          >>> 'h' in d                # search the deque
          True

     Several modules, such as the ‘Queue’ and *note threading: f3.
     modules, now take advantage of *note collections.deque: 7f5. for
     improved performance.  (Contributed by Raymond Hettinger.)

   * The *note ConfigParser: 26. classes have been enhanced slightly.
     The *note read(): 166f. method now returns a list of the files that
     were successfully parsed, and the *note set(): 1474. method raises
     *note TypeError: 198. if passed a 'value' argument that isn’t a
     string.  (Contributed by John Belmonte and David Goodger.)

   * The *note curses: 2f. module now supports the ncurses extension
     ‘use_default_colors()’.  On platforms where the terminal supports
     transparency, this makes it possible to use a transparent
     background.  (Contributed by Jörg Lehmann.)

   * The *note difflib: 3b. module now includes an ‘HtmlDiff’ class that
     creates an HTML table showing a side by side comparison of two
     versions of a text.  (Contributed by Dan Gass.)

   * The *note email: 3f. package was updated to version 3.0, which
     dropped various deprecated APIs and removes support for Python
     versions earlier than 2.3.  The 3.0 version of the package uses a
     new incremental parser for MIME messages, available in the
     ‘email.FeedParser’ module.  The new parser doesn’t require reading
     the entire message into memory, and doesn’t raise exceptions if a
     message is malformed; instead it records any problems in the
     ‘defect’ attribute of the message.  (Developed by Anthony Baxter,
     Barry Warsaw, Thomas Wouters, and others.)

   * The *note heapq: 6d. module has been converted to C. The resulting
     tenfold improvement in speed makes the module suitable for handling
     high volumes of data.  In addition, the module has two new
     functions ‘nlargest()’ and ‘nsmallest()’ that use heaps to find the
     N largest or smallest values in a dataset without the expense of a
     full sort.  (Contributed by Raymond Hettinger.)

   * The *note httplib: 72. module now contains constants for HTTP
     status codes defined in various HTTP-related RFC documents.
     Constants have names such as ‘OK’, ‘CREATED’, ‘CONTINUE’, and
     ‘MOVED_PERMANENTLY’; use pydoc to get a full list.  (Contributed by
     Andrew Eland.)

   * The *note imaplib: 78. module now supports IMAP’s THREAD command
     (contributed by Yves Dionne) and new ‘deleteacl()’ and ‘myrights()’
     methods (contributed by Arnaud Mazin).

   * The *note itertools: 85. module gained a ‘groupby(iterable[,
     *func*])’ function.  'iterable' is something that can be iterated
     over to return a stream of elements, and the optional 'func'
     parameter is a function that takes an element and returns a key
     value; if omitted, the key is simply the element itself.
     ‘groupby()’ then groups the elements into subsequences which have
     matching values of the key, and returns a series of 2-tuples
     containing the key value and an iterator over the subsequence.

     Here’s an example to make this clearer.  The 'key' function simply
     returns whether a number is even or odd, so the result of
     ‘groupby()’ is to return consecutive runs of odd or even numbers.

          >>> import itertools
          >>> L = [2, 4, 6, 7, 8, 9, 11, 12, 14]
          >>> for key_val, it in itertools.groupby(L, lambda x: x % 2):
          ...    print key_val, list(it)
          ...
          0 [2, 4, 6]
          1 [7]
          0 [8]
          1 [9, 11]
          0 [12, 14]
          >>>

     ‘groupby()’ is typically used with sorted input.  The logic for
     ‘groupby()’ is similar to the Unix ‘uniq’ filter which makes it
     handy for eliminating, counting, or identifying duplicate elements:

          >>> word = 'abracadabra'
          >>> letters = sorted(word)   # Turn string into a sorted list of letters
          >>> letters
          ['a', 'a', 'a', 'a', 'a', 'b', 'b', 'c', 'd', 'r', 'r']
          >>> for k, g in itertools.groupby(letters):
          ...    print k, list(g)
          ...
          a ['a', 'a', 'a', 'a', 'a']
          b ['b', 'b']
          c ['c']
          d ['d']
          r ['r', 'r']
          >>> # List unique letters
          >>> [k for k, g in groupby(letters)]
          ['a', 'b', 'c', 'd', 'r']
          >>> # Count letter occurrences
          >>> [(k, len(list(g))) for k, g in groupby(letters)]
          [('a', 5), ('b', 2), ('c', 1), ('d', 1), ('r', 2)]

     (Contributed by Hye-Shik Chang.)

   * *note itertools: 85. also gained a function named ‘tee(iterator,
     N)’ that returns 'N' independent iterators that replicate
     'iterator'.  If 'N' is omitted, the default is 2.

          >>> L = [1,2,3]
          >>> i1, i2 = itertools.tee(L)
          >>> i1,i2
          (<itertools.tee object at 0x402c2080>, <itertools.tee object at 0x402c2090>)
          >>> list(i1)               # Run the first iterator to exhaustion
          [1, 2, 3]
          >>> list(i2)               # Run the second iterator to exhaustion
          [1, 2, 3]

     Note that ‘tee()’ has to keep copies of the values returned by the
     iterator; in the worst case, it may need to keep all of them.  This
     should therefore be used carefully if the leading iterator can run
     far ahead of the trailing iterator in a long stream of inputs.  If
     the separation is large, then you might as well use *note list():
     24d. instead.  When the iterators track closely with one another,
     ‘tee()’ is ideal.  Possible applications include bookmarking,
     windowing, or lookahead iterators.  (Contributed by Raymond
     Hettinger.)

   * A number of functions were added to the *note locale: 8a. module,
     such as ‘bind_textdomain_codeset()’ to specify a particular
     encoding and a family of ‘l*gettext()’ functions that return
     messages in the chosen encoding.  (Contributed by Gustavo
     Niemeyer.)

   * Some keyword arguments were added to the *note logging: 8b.
     package’s ‘basicConfig()’ function to simplify log configuration.
     The default behavior is to log messages to standard error, but
     various keyword arguments can be specified to log to a particular
     file, change the logging format, or set the logging level.  For
     example:

          import logging
          logging.basicConfig(filename='/var/log/application.log',
              level=0,  # Log all messages
              format='%(levelname):%(process):%(thread):%(message)')

     Other additions to the *note logging: 8b. package include a
     ‘log(level, msg)’ convenience method, as well as a
     ‘TimedRotatingFileHandler’ class that rotates its log files at a
     timed interval.  The module already had ‘RotatingFileHandler’,
     which rotated logs once the file exceeded a certain size.  Both
     classes derive from a new ‘BaseRotatingHandler’ class that can be
     used to implement other rotating handlers.

     (Changes implemented by Vinay Sajip.)

   * The *note marshal: 91. module now shares interned strings on
     unpacking a data structure.  This may shrink the size of certain
     pickle strings, but the primary effect is to make ‘.pyc’ files
     significantly smaller.  (Contributed by Martin von Löwis.)

   * The ‘nntplib’ module’s ‘NNTP’ class gained ‘description()’ and
     ‘descriptions()’ methods to retrieve newsgroup descriptions for a
     single group or for a range of groups.  (Contributed by Jürgen A.
     Erhard.)

   * Two new functions were added to the *note operator: a3. module,
     ‘attrgetter(attr)’ and ‘itemgetter(index)’.  Both functions return
     callables that take a single argument and return the corresponding
     attribute or item; these callables make excellent data extractors
     when used with *note map(): 19f. or *note sorted(): dc9.  For
     example:

          >>> L = [('c', 2), ('d', 1), ('a', 4), ('b', 3)]
          >>> map(operator.itemgetter(0), L)
          ['c', 'd', 'a', 'b']
          >>> map(operator.itemgetter(1), L)
          [2, 1, 4, 3]
          >>> sorted(L, key=operator.itemgetter(1)) # Sort list by second tuple item
          [('d', 1), ('c', 2), ('b', 3), ('a', 4)]

     (Contributed by Raymond Hettinger.)

   * The *note optparse: a4. module was updated in various ways.  The
     module now passes its messages through *note gettext.gettext():
     1670, making it possible to internationalize Optik’s help and error
     messages.  Help messages for options can now include the string
     ‘'%default'’, which will be replaced by the option’s default value.
     (Contributed by Greg Ward.)

   * The long-term plan is to deprecate the ‘rfc822’ module in some
     future Python release in favor of the *note email: 3f. package.  To
     this end, the *note email.Utils.formatdate: 1671. function has been
     changed to make it usable as a replacement for
     ‘rfc822.formatdate()’.  You may want to write new e-mail processing
     code with this in mind.  (Change implemented by Anthony Baxter.)

   * A new ‘urandom(n)’ function was added to the *note os: a5. module,
     returning a string containing 'n' bytes of random data.  This
     function provides access to platform-specific sources of randomness
     such as ‘/dev/urandom’ on Linux or the Windows CryptoAPI.
     (Contributed by Trevor Perrin.)

   * Another new function: ‘os.path.lexists(path)’ returns true if the
     file specified by 'path' exists, whether or not it’s a symbolic
     link.  This differs from the existing ‘os.path.exists(path)’
     function, which returns false if 'path' is a symlink that points to
     a destination that doesn’t exist.  (Contributed by Beni
     Cherniavsky.)

   * A new ‘getsid()’ function was added to the *note posix: b2. module
     that underlies the *note os: a5. module.  (Contributed by J.
     Raynor.)

   * The *note poplib: b1. module now supports POP over SSL.
     (Contributed by Hector Urtubia.)

   * The *note profile: b4. module can now profile C extension
     functions.  (Contributed by Nick Bastin.)

   * The *note random: bd. module has a new method called
     ‘getrandbits(N)’ that returns a long integer 'N' bits in length.
     The existing ‘randrange()’ method now uses ‘getrandbits()’ where
     appropriate, making generation of arbitrarily large random numbers
     more efficient.  (Contributed by Raymond Hettinger.)

   * The regular expression language accepted by the *note re: be.
     module was extended with simple conditional expressions, written as
     ‘(?(group)A|B)’.  'group' is either a numeric group ID or a group
     name defined with ‘(?P<group>...)’ earlier in the expression.  If
     the specified group matched, the regular expression pattern 'A'
     will be tested against the string; if the group didn’t match, the
     pattern 'B' will be used instead.  (Contributed by Gustavo
     Niemeyer.)

   * The *note re: be. module is also no longer recursive, thanks to a
     massive amount of work by Gustavo Niemeyer.  In a recursive regular
     expression engine, certain patterns result in a large amount of C
     stack space being consumed, and it was possible to overflow the
     stack.  For example, if you matched a 30000-byte string of ‘a’
     characters against the expression ‘(a|b)+’, one stack frame was
     consumed per character.  Python 2.3 tried to check for stack
     overflow and raise a *note RuntimeError: 244. exception, but
     certain patterns could sidestep the checking and if you were
     unlucky Python could segfault.  Python 2.4’s regular expression
     engine can match this pattern without problems.

   * The *note signal: cb. module now performs tighter error-checking on
     the parameters to the *note signal.signal(): 133c. function.  For
     example, you can’t set a handler on the ‘SIGKILL’ signal; previous
     versions of Python would quietly accept this, but 2.4 will raise a
     *note RuntimeError: 244. exception.

   * Two new functions were added to the *note socket: d1. module.
     ‘socketpair()’ returns a pair of connected sockets and
     ‘getservbyport(port)’ looks up the service name for a given port
     number.  (Contributed by Dave Cole and Barry Warsaw.)

   * The ‘sys.exitfunc()’ function has been deprecated.  Code should be
     using the existing *note atexit: d. module, which correctly handles
     calling multiple exit functions.  Eventually ‘sys.exitfunc()’ will
     become a purely internal interface, accessed only by *note atexit:
     d.

   * The *note tarfile: e4. module now generates GNU-format tar files by
     default.  (Contributed by Lars Gustäbel.)

   * The *note threading: f3. module now has an elegantly simple way to
     support thread-local data.  The module contains a ‘local’ class
     whose attribute values are local to different threads.

          import threading

          data = threading.local()
          data.number = 42
          data.url = ('www.python.org', 80)

     Other threads can assign and retrieve their own values for the
     ‘number’ and ‘url’ attributes.  You can subclass ‘local’ to
     initialize attributes or to add methods.  (Contributed by Jim
     Fulton.)

   * The *note timeit: f5. module now automatically disables periodic
     garbage collection during the timing loop.  This change makes
     consecutive timings more comparable.  (Contributed by Raymond
     Hettinger.)

   * The *note weakref: 11a. module now supports a wider variety of
     objects including Python functions, class instances, sets,
     frozensets, deques, arrays, files, sockets, and regular expression
     pattern objects.  (Contributed by Raymond Hettinger.)

   * The *note xmlrpclib: 134. module now supports a multi-call
     extension for transmitting multiple XML-RPC calls in a single HTTP
     operation.  (Contributed by Brian Quinlan.)

   * The ‘mpz’, ‘rotor’, and ‘xreadlines’ modules have been removed.

* Menu:

* cookielib::
* doctest: doctest<5>.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc3548.html


File: python.info,  Node: cookielib,  Next: doctest<5>,  Up: New Improved and Deprecated Modules<3>

1.19.12.1 cookielib
...................

The *note cookielib: 74. library supports client-side handling for HTTP
cookies, mirroring the *note Cookie: 75. module’s server-side cookie
support.  Cookies are stored in cookie jars; the library transparently
stores cookies offered by the web server in the cookie jar, and fetches
the cookie from the jar when connecting to the server.  As in web
browsers, policy objects control whether cookies are accepted or not.

In order to store cookies across sessions, two implementations of cookie
jars are provided: one that stores cookies in the Netscape format so
applications can use the Mozilla or Lynx cookie files, and one that
stores cookies in the same format as the Perl libwww library.

*note urllib2: 111. has been changed to interact with *note cookielib:
74.: ‘HTTPCookieProcessor’ manages a cookie jar that is used when
accessing URLs.

This module was contributed by John J. Lee.


File: python.info,  Node: doctest<5>,  Prev: cookielib,  Up: New Improved and Deprecated Modules<3>

1.19.12.2 doctest
.................

The *note doctest: 3e. module underwent considerable refactoring thanks
to Edward Loper and Tim Peters.  Testing can still be as simple as
running *note doctest.testmod(): 1674, but the refactorings allow
customizing the module’s operation in various ways

The new ‘DocTestFinder’ class extracts the tests from a given object’s
docstrings:

     def f (x, y):
         """>>> f(2,2)
     4
     >>> f(3,2)
     6
         """
         return x*y

     finder = doctest.DocTestFinder()

     # Get list of DocTest instances
     tests = finder.find(f)

The new ‘DocTestRunner’ class then runs individual tests and can produce
a summary of the results:

     runner = doctest.DocTestRunner()
     for t in tests:
         tried, failed = runner.run(t)

     runner.summarize(verbose=1)

The above example produces the following output:

     1 items passed all tests:
        2 tests in f
     2 tests in 1 items.
     2 passed and 0 failed.
     Test passed.

‘DocTestRunner’ uses an instance of the ‘OutputChecker’ class to compare
the expected output with the actual output.  This class takes a number
of different flags that customize its behaviour; ambitious users can
also write a completely new subclass of ‘OutputChecker’.

The default output checker provides a number of handy features.  For
example, with the *note doctest.ELLIPSIS: 1675. option flag, an ellipsis
(‘...’) in the expected output matches any substring, making it easier
to accommodate outputs that vary in minor ways:

     def o (n):
         """>>> o(1)
     <__main__.C instance at 0x...>
     >>>
     """

Another special string, ‘<BLANKLINE>’, matches a blank line:

     def p (n):
         """>>> p(1)
     <BLANKLINE>
     >>>
     """

Another new capability is producing a diff-style display of the output
by specifying the *note doctest.REPORT_UDIFF: 1676. (unified diffs),
*note doctest.REPORT_CDIFF: 1677. (context diffs), or *note
doctest.REPORT_NDIFF: 1678. (delta-style) option flags.  For example:

     def g (n):
         """>>> g(4)
     here
     is
     a
     lengthy
     >>>"""
         L = 'here is a rather lengthy list of words'.split()
         for word in L[:n]:
             print word

Running the above function’s tests with *note doctest.REPORT_UDIFF:
1676. specified, you get the following output:

     **********************************************************************
     File "t.py", line 15, in g
     Failed example:
         g(4)
     Differences (unified diff with -expected +actual):
         @@ -2,3 +2,3 @@
          is
          a
         -lengthy
         +rather
     **********************************************************************


File: python.info,  Node: Build and C API Changes<11>,  Next: Porting to Python 2 4,  Prev: New Improved and Deprecated Modules<3>,  Up: What’s New in Python 2 4

1.19.13 Build and C API Changes
-------------------------------

Some of the changes to Python’s build process and to the C API are:

   * Three new convenience macros were added for common return values
     from extension functions: *note Py_RETURN_NONE: 167a, *note
     Py_RETURN_TRUE: 167b, and *note Py_RETURN_FALSE: 167c.
     (Contributed by Brett Cannon.)

   * Another new macro, *note Py_CLEAR: 799, decreases the reference
     count of 'obj' and sets 'obj' to the null pointer.  (Contributed by
     Jim Fulton.)

   * A new function, ‘PyTuple_Pack(N, obj1, obj2, ..., objN)’,
     constructs tuples from a variable length argument list of Python
     objects.  (Contributed by Raymond Hettinger.)

   * A new function, ‘PyDict_Contains(d, k)’, implements fast dictionary
     lookups without masking exceptions raised during the look-up
     process.  (Contributed by Raymond Hettinger.)

   * The *note Py_IS_NAN: 167d.(X) macro returns 1 if its float or
     double argument 'X' is a NaN. (Contributed by Tim Peters.)

   * C code can avoid unnecessary locking by using the new
     ‘PyEval_ThreadsInitialized()’ function to tell if any thread
     operations have been performed.  If this function returns false, no
     lock operations are needed.  (Contributed by Nick Coghlan.)

   * A new function, *note PyArg_VaParseTupleAndKeywords(): 625, is the
     same as *note PyArg_ParseTupleAndKeywords(): 624. but takes a
     ‘va_list’ instead of a number of arguments.  (Contributed by Greg
     Chapman.)

   * A new method flag, *note METH_COEXIST: 167e, allows a function
     defined in slots to co-exist with a *note PyCFunction: 167f. having
     the same name.  This can halve the access time for a method such as
     ‘set.__contains__()’.  (Contributed by Raymond Hettinger.)

   * Python can now be built with additional profiling for the
     interpreter itself, intended as an aid to people developing the
     Python core.  Providing ‘--enable-profiling’ to the ‘configure’
     script will let you profile the interpreter with ‘gprof’, and
     providing the ‘--with-tsc’ switch enables profiling using the
     Pentium’s Time-Stamp-Counter register.  Note that the ‘--with-tsc’
     switch is slightly misnamed, because the profiling feature also
     works on the PowerPC platform, though that processor architecture
     doesn’t call that register «the TSC register».  (Contributed by
     Jeremy Hylton.)

   * The ‘tracebackobject’ type has been renamed to ‘PyTracebackObject’.

* Menu:

* Port-Specific Changes: Port-Specific Changes<2>.


File: python.info,  Node: Port-Specific Changes<2>,  Up: Build and C API Changes<11>

1.19.13.1 Port-Specific Changes
...............................

   * The Windows port now builds under MSVC++ 7.1 as well as version 6.
     (Contributed by Martin von Löwis.)


File: python.info,  Node: Porting to Python 2 4,  Next: Acknowledgements<4>,  Prev: Build and C API Changes<11>,  Up: What’s New in Python 2 4

1.19.14 Porting to Python 2.4
-----------------------------

This section lists previously described changes that may require changes
to your code:

   * Left shifts and hexadecimal/octal constants that are too large no
     longer trigger a *note FutureWarning: 659. and return a value
     limited to 32 or 64 bits; instead they return a long integer.

   * Integer operations will no longer trigger an ‘OverflowWarning’.
     The ‘OverflowWarning’ warning will disappear in Python 2.5.

   * The *note zip(): 1a0. built-in function and ‘itertools.izip()’ now
     return an empty list instead of raising a *note TypeError: 198.
     exception if called with no arguments.

   * You can no longer compare the ‘date’ and *note datetime: 4e3.
     instances provided by the *note datetime: 34. module.  Two
     instances of different classes will now always be unequal, and
     relative comparisons (‘<’, ‘>’) will raise a *note TypeError: 198.

   * ‘dircache.listdir()’ now passes exceptions to the caller instead of
     returning empty lists.

   * ‘LexicalHandler.startDTD()’ used to receive the public and system
     IDs in the wrong order.  This has been corrected; applications
     relying on the wrong order need to be fixed.

   * *note fcntl.ioctl(): 1682. now warns if the 'mutate' argument is
     omitted and relevant.

   * The *note tarfile: e4. module now generates GNU-format tar files by
     default.

   * Encountering a failure while importing a module no longer leaves a
     partially initialized module object in ‘sys.modules’.

   * *note None: 886. is now a constant; code that binds a new value to
     the name ‘None’ is now a syntax error.

   * The ‘signals.signal()’ function now raises a *note RuntimeError:
     244. exception for certain illegal values; previously these errors
     would pass silently.  For example, you can no longer set a handler
     on the ‘SIGKILL’ signal.


File: python.info,  Node: Acknowledgements<4>,  Prev: Porting to Python 2 4,  Up: What’s New in Python 2 4

1.19.15 Acknowledgements
------------------------

The author would like to thank the following people for offering
suggestions, corrections and assistance with various drafts of this
article: Koray Can, Hye-Shik Chang, Michael Dyck, Raymond Hettinger,
Brian Hurt, Hamish Lawson, Fredrik Lundh, Sean Reifschneider, Sadruddin
Rejeb.


File: python.info,  Node: What’s New in Python 2 3,  Next: What’s New in Python 2 2,  Prev: What’s New in Python 2 4,  Up: Novità in Python

1.20 What’s New in Python 2.3
=============================


Author: A.M. Kuchling

This article explains the new features in Python 2.3.  Python 2.3 was
released on July 29, 2003.

The main themes for Python 2.3 are polishing some of the features added
in 2.2, adding various small but useful enhancements to the core
language, and expanding the standard library.  The new object model
introduced in the previous version has benefited from 18 months of
bugfixes and from optimization efforts that have improved the
performance of new-style classes.  A few new built-in functions have
been added such as *note sum(): 696. and *note enumerate(): 1688.  The
*note in: 34b. operator can now be used for substring searches (e.g.
‘"ab" in "abc"’ returns *note True: e09.).

Some of the many new library features include Boolean, set, heap, and
date/time data types, the ability to import modules from ZIP-format
archives, metadata support for the long-awaited Python catalog, an
updated version of IDLE, and modules for logging messages, wrapping
text, parsing CSV files, processing command-line options, using
BerkeleyDB databases… the list of new and enhanced modules is lengthy.

This article doesn’t attempt to provide a complete specification of the
new features, but instead provides a convenient overview.  For full
details, you should refer to the documentation for Python 2.3, such as
the Python Library Reference and the Python Reference Manual.  If you
want to understand the complete implementation and design rationale,
refer to the PEP for a particular new feature.

* Menu:

* PEP 218; A Standard Set Datatype: PEP 218 A Standard Set Datatype.
* PEP 255; Simple Generators: PEP 255 Simple Generators.
* PEP 263; Source Code Encodings: PEP 263 Source Code Encodings.
* PEP 273; Importing Modules from ZIP Archives: PEP 273 Importing Modules from ZIP Archives.
* PEP 277; Unicode file name support for Windows NT: PEP 277 Unicode file name support for Windows NT.
* PEP 278; Universal Newline Support: PEP 278 Universal Newline Support.
* PEP 279; enumerate(): PEP 279 enumerate.
* PEP 282; The logging Package: PEP 282 The logging Package.
* PEP 285; A Boolean Type: PEP 285 A Boolean Type.
* PEP 293; Codec Error Handling Callbacks: PEP 293 Codec Error Handling Callbacks.
* PEP 301; Package Index and Metadata for Distutils: PEP 301 Package Index and Metadata for Distutils.
* PEP 302; New Import Hooks: PEP 302 New Import Hooks.
* PEP 305; Comma-separated Files: PEP 305 Comma-separated Files.
* PEP 307; Pickle Enhancements: PEP 307 Pickle Enhancements.
* Extended Slices::
* Other Language Changes: Other Language Changes<17>.
* New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<4>.
* Pymalloc; A Specialized Object Allocator: Pymalloc A Specialized Object Allocator.
* Build and C API Changes: Build and C API Changes<12>.
* Other Changes and Fixes: Other Changes and Fixes<2>.
* Porting to Python 2.3: Porting to Python 2 3.
* Acknowledgements: Acknowledgements<5>.


File: python.info,  Node: PEP 218 A Standard Set Datatype,  Next: PEP 255 Simple Generators,  Up: What’s New in Python 2 3

1.20.1 PEP 218: A Standard Set Datatype
---------------------------------------

The new ‘sets’ module contains an implementation of a set datatype.  The
‘Set’ class is for mutable sets, sets that can have members added and
removed.  The ‘ImmutableSet’ class is for sets that can’t be modified,
and instances of ‘ImmutableSet’ can therefore be used as dictionary
keys.  Sets are built on top of dictionaries, so the elements within a
set must be hashable.

Here’s a simple example:

     >>> import sets
     >>> S = sets.Set([1,2,3])
     >>> S
     Set([1, 2, 3])
     >>> 1 in S
     True
     >>> 0 in S
     False
     >>> S.add(5)
     >>> S.remove(3)
     >>> S
     Set([1, 2, 5])
     >>>

The union and intersection of sets can be computed with the *note
union(): 168a. and *note intersection(): 168b. methods; an alternative
notation uses the bitwise operators ‘&’ and ‘|’.  Mutable sets also have
in-place versions of these methods, ‘union_update()’ and *note
intersection_update(): 168c.

     >>> S1 = sets.Set([1,2,3])
     >>> S2 = sets.Set([4,5,6])
     >>> S1.union(S2)
     Set([1, 2, 3, 4, 5, 6])
     >>> S1 | S2                  # Alternative notation
     Set([1, 2, 3, 4, 5, 6])
     >>> S1.intersection(S2)
     Set([])
     >>> S1 & S2                  # Alternative notation
     Set([])
     >>> S1.union_update(S2)
     >>> S1
     Set([1, 2, 3, 4, 5, 6])
     >>>

It’s also possible to take the symmetric difference of two sets.  This
is the set of all elements in the union that aren’t in the intersection.
Another way of putting it is that the symmetric difference contains all
elements that are in exactly one set.  Again, there’s an alternative
notation (‘^’), and an in-place version with the ungainly name *note
symmetric_difference_update(): 168d.

     >>> S1 = sets.Set([1,2,3,4])
     >>> S2 = sets.Set([3,4,5,6])
     >>> S1.symmetric_difference(S2)
     Set([1, 2, 5, 6])
     >>> S1 ^ S2
     Set([1, 2, 5, 6])
     >>>

There are also ‘issubset()’ and ‘issuperset()’ methods for checking
whether one set is a subset or superset of another:

     >>> S1 = sets.Set([1,2,3])
     >>> S2 = sets.Set([2,3])
     >>> S2.issubset(S1)
     True
     >>> S1.issubset(S2)
     False
     >>> S1.issuperset(S2)
     True
     >>>

Vedi anche
..........

PEP 218(1) - Adding a Built-In Set Object Type

     PEP written by Greg V. Wilson.  Implemented by Greg V. Wilson, Alex
     Martelli, and GvR.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0218/


File: python.info,  Node: PEP 255 Simple Generators,  Next: PEP 263 Source Code Encodings,  Prev: PEP 218 A Standard Set Datatype,  Up: What’s New in Python 2 3

1.20.2 PEP 255: Simple Generators
---------------------------------

In Python 2.2, generators were added as an optional feature, to be
enabled by a ‘from __future__ import generators’ directive.  In 2.3
generators no longer need to be specially enabled, and are now always
present; this means that *note yield: bc4. is now always a keyword.  The
rest of this section is a copy of the description of generators from the
«What’s New in Python 2.2» document; if you read it back when Python 2.2
came out, you can skip the rest of this section.

You’re doubtless familiar with how function calls work in Python or C.
When you call a function, it gets a private namespace where its local
variables are created.  When the function reaches a *note return: 1af.
statement, the local variables are destroyed and the resulting value is
returned to the caller.  A later call to the same function will get a
fresh new set of local variables.  But, what if the local variables
weren’t thrown away on exiting a function?  What if you could later
resume the function where it left off?  This is what generators provide;
they can be thought of as resumable functions.

Here’s the simplest example of a generator function:

     def generate_ints(N):
         for i in range(N):
             yield i

A new keyword, *note yield: bc4, was introduced for generators.  Any
function containing a ‘yield’ statement is a generator function; this is
detected by Python’s bytecode compiler which compiles the function
specially as a result.

When you call a generator function, it doesn’t return a single value;
instead it returns a generator object that supports the iterator
protocol.  On executing the *note yield: bc4. statement, the generator
outputs the value of ‘i’, similar to a *note return: 1af. statement.
The big difference between ‘yield’ and a ‘return’ statement is that on
reaching a ‘yield’ the generator’s state of execution is suspended and
local variables are preserved.  On the next call to the generator’s
‘.next()’ method, the function will resume executing immediately after
the ‘yield’ statement.  (For complicated reasons, the ‘yield’ statement
isn’t allowed inside the *note try: 8f9. block of a ‘try’…‘finally’
statement; read PEP 255(1) for a full explanation of the interaction
between ‘yield’ and exceptions.)

Here’s a sample usage of the ‘generate_ints()’ generator:

     >>> gen = generate_ints(3)
     >>> gen
     <generator object at 0x8117f90>
     >>> gen.next()
     0
     >>> gen.next()
     1
     >>> gen.next()
     2
     >>> gen.next()
     Traceback (most recent call last):
       File "stdin", line 1, in ?
       File "stdin", line 2, in generate_ints
     StopIteration

You could equally write ‘for i in generate_ints(5)’, or ‘a,b,c =
generate_ints(3)’.

Inside a generator function, the *note return: 1af. statement can only
be used without a value, and signals the end of the procession of
values; afterwards the generator cannot return any further values.
‘return’ with a value, such as ‘return 5’, is a syntax error inside a
generator function.  The end of the generator’s results can also be
indicated by raising *note StopIteration: df7. manually, or by just
letting the flow of execution fall off the bottom of the function.

You could achieve the effect of generators manually by writing your own
class and storing all the local variables of the generator as instance
variables.  For example, returning a list of integers could be done by
setting ‘self.count’ to 0, and having the *note next(): 9da. method
increment ‘self.count’ and return it.  However, for a moderately
complicated generator, writing a corresponding class would be much
messier.  ‘Lib/test/test_generators.py’ contains a number of more
interesting examples.  The simplest one implements an in-order traversal
of a tree using generators recursively.

     # A recursive generator that generates Tree leaves in in-order.
     def inorder(t):
         if t:
             for x in inorder(t.left):
                 yield x
             yield t.label
             for x in inorder(t.right):
                 yield x

Two other examples in ‘Lib/test/test_generators.py’ produce solutions
for the N-Queens problem (placing $N$ queens on an $NxN$ chess board so
that no queen threatens another) and the Knight’s Tour (a route that
takes a knight to every square of an $NxN$ chessboard without visiting
any square twice).

The idea of generators comes from other programming languages,
especially Icon (‘https://www2.cs.arizona.edu/icon/’), where the idea of
generators is central.  In Icon, every expression and function call
behaves like a generator.  One example from «An Overview of the Icon
Programming Language» at
‘https://www2.cs.arizona.edu/icon/docs/ipd266.htm’ gives an idea of what
this looks like:

     sentence := "Store it in the neighboring harbor"
     if (i := find("or", sentence)) > 5 then write(i)

In Icon the ‘find()’ function returns the indexes at which the substring
«or» is found: 3, 23, 33.  In the *note if: 181. statement, ‘i’ is first
assigned a value of 3, but 3 is less than 5, so the comparison fails,
and Icon retries it with the second value of 23.  23 is greater than 5,
so the comparison now succeeds, and the code prints the value 23 to the
screen.

Python doesn’t go nearly as far as Icon in adopting generators as a
central concept.  Generators are considered part of the core Python
language, but learning or using them isn’t compulsory; if they don’t
solve any problems that you have, feel free to ignore them.  One novel
feature of Python’s interface as compared to Icon’s is that a
generator’s state is represented as a concrete object (the iterator)
that can be passed around to other functions or stored in a data
structure.

Vedi anche
..........

PEP 255(2) - Simple Generators

     Written by Neil Schemenauer, Tim Peters, Magnus Lie Hetland.
     Implemented mostly by Neil Schemenauer and Tim Peters, with other
     fixes from the Python Labs crew.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0255/

   (2) https://peps.python.org/pep-0255/


File: python.info,  Node: PEP 263 Source Code Encodings,  Next: PEP 273 Importing Modules from ZIP Archives,  Prev: PEP 255 Simple Generators,  Up: What’s New in Python 2 3

1.20.3 PEP 263: Source Code Encodings
-------------------------------------

Python source files can now be declared as being in different character
set encodings.  Encodings are declared by including a specially
formatted comment in the first or second line of the source file.  For
example, a UTF-8 file can be declared with:

     #!/usr/bin/env python
     # -*- coding: UTF-8 -*-

Without such an encoding declaration, the default encoding used is 7-bit
ASCII. Executing or importing modules that contain string literals with
8-bit characters and have no encoding declaration will result in a *note
DeprecationWarning: 1a3. being signalled by Python 2.3; in 2.4 this will
be a syntax error.

The encoding declaration only affects Unicode string literals, which
will be converted to Unicode using the specified encoding.  Note that
Python identifiers are still restricted to ASCII characters, so you
can’t have variable names that use characters outside of the usual
alphanumerics.

Vedi anche
..........

PEP 263(1) - Defining Python Source Code Encodings

     Written by Marc-André Lemburg and Martin von Löwis; implemented by
     Suzuki Hisao and Martin von Löwis.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0263/


File: python.info,  Node: PEP 273 Importing Modules from ZIP Archives,  Next: PEP 277 Unicode file name support for Windows NT,  Prev: PEP 263 Source Code Encodings,  Up: What’s New in Python 2 3

1.20.4 PEP 273: Importing Modules from ZIP Archives
---------------------------------------------------

The new *note zipimport: 138. module adds support for importing modules
from a ZIP-format archive.  You don’t need to import the module
explicitly; it will be automatically imported if a ZIP archive’s
filename is added to ‘sys.path’.  For example:

     amk@nyman:~/src/python$ unzip -l /tmp/example.zip
     Archive:  /tmp/example.zip
       Length     Date   Time    Name
      --------    ----   ----    ----
          8467  11-26-02 22:30   jwzthreading.py
      --------                   -------
          8467                   1 file
     amk@nyman:~/src/python$ ./python
     Python 2.3 (#1, Aug 1 2003, 19:54:32)
     >>> import sys
     >>> sys.path.insert(0, '/tmp/example.zip')  # Add .zip file to front of path
     >>> import jwzthreading
     >>> jwzthreading.__file__
     '/tmp/example.zip/jwzthreading.py'
     >>>

An entry in ‘sys.path’ can now be the filename of a ZIP archive.  The
ZIP archive can contain any kind of files, but only files named ‘*.py’,
‘*.pyc’, or ‘*.pyo’ can be imported.  If an archive only contains ‘*.py’
files, Python will not attempt to modify the archive by adding the
corresponding ‘*.pyc’ file, meaning that if a ZIP archive doesn’t
contain ‘*.pyc’ files, importing may be rather slow.

A path within the archive can also be specified to only import from a
subdirectory; for example, the path ‘/tmp/example.zip/lib/’ would only
import from the ‘lib/’ subdirectory within the archive.

Vedi anche
..........

PEP 273(1) - Import Modules from Zip Archives

     Written by James C. Ahlstrom, who also provided an implementation.
     Python 2.3 follows the specification in PEP 273(2), but uses an
     implementation written by Just van Rossum that uses the import
     hooks described in PEP 302(3).  See section *note PEP 302; New
     Import Hooks: 1693. for a description of the new import hooks.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0273/

   (2) https://peps.python.org/pep-0273/

   (3) https://peps.python.org/pep-0302/


File: python.info,  Node: PEP 277 Unicode file name support for Windows NT,  Next: PEP 278 Universal Newline Support,  Prev: PEP 273 Importing Modules from ZIP Archives,  Up: What’s New in Python 2 3

1.20.5 PEP 277: Unicode file name support for Windows NT
--------------------------------------------------------

On Windows NT, 2000, and XP, the system stores file names as Unicode
strings.  Traditionally, Python has represented file names as byte
strings, which is inadequate because it renders some file names
inaccessible.

Python now allows using arbitrary Unicode strings (within the
limitations of the file system) for all functions that expect file
names, most notably the *note open(): 316. built-in function.  If a
Unicode string is passed to *note os.listdir(): 1302, Python now returns
a list of Unicode strings.  A new function, ‘os.getcwdu()’, returns the
current directory as a Unicode string.

Byte strings still work as file names, and on Windows Python will
transparently convert them to Unicode using the ‘mbcs’ encoding.

Other systems also allow Unicode strings as file names but convert them
to byte strings before passing them to the system, which can cause a
*note UnicodeError: 462. to be raised.  Applications can test whether
arbitrary Unicode strings are supported as file names by checking *note
os.path.supports_unicode_filenames: 1695, a Boolean value.

Under MacOS, *note os.listdir(): 1302. may now return Unicode filenames.

Vedi anche
..........

PEP 277(1) - Unicode file name support for Windows NT

     Written by Neil Hodgson; implemented by Neil Hodgson, Martin von
     Löwis, and Mark Hammond.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0277/


File: python.info,  Node: PEP 278 Universal Newline Support,  Next: PEP 279 enumerate,  Prev: PEP 277 Unicode file name support for Windows NT,  Up: What’s New in Python 2 3

1.20.6 PEP 278: Universal Newline Support
-----------------------------------------

The three major operating systems used today are Microsoft Windows,
Apple’s Macintosh OS, and the various Unix derivatives.  A minor
irritation of cross-platform work is that these three platforms all use
different characters to mark the ends of lines in text files.  Unix uses
the linefeed (ASCII character 10), MacOS uses the carriage return (ASCII
character 13), and Windows uses a two-character sequence of a carriage
return plus a newline.

Python’s file objects can now support end of line conventions other than
the one followed by the platform on which Python is running.  Opening a
file with the mode ‘'U'’ or ‘'rU'’ will open a file for reading in *note
universal newlines: f37. mode.  All three line ending conventions will
be translated to a ‘'\n'’ in the strings returned by the various file
methods such as ‘read()’ and ‘readline()’.

Universal newline support is also used when importing modules and when
executing a file with the ‘execfile()’ function.  This means that Python
modules can be shared between all three operating systems without
needing to convert the line-endings.

This feature can be disabled when compiling Python by specifying the
‘--without-universal-newlines’ switch when running Python’s ‘configure’
script.

Vedi anche
..........

PEP 278(1) - Universal Newline Support

     Written and implemented by Jack Jansen.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0278/


File: python.info,  Node: PEP 279 enumerate,  Next: PEP 282 The logging Package,  Prev: PEP 278 Universal Newline Support,  Up: What’s New in Python 2 3

1.20.7 PEP 279: enumerate()
---------------------------

A new built-in function, *note enumerate(): 1688, will make certain
loops a bit clearer.  ‘enumerate(thing)’, where 'thing' is either an
iterator or a sequence, returns an iterator that will return ‘(0,
thing[0])’, ‘(1, thing[1])’, ‘(2, thing[2])’, and so forth.

A common idiom to change every element of a list looks like this:

     for i in range(len(L)):
         item = L[i]
         # ... compute some result based on item ...
         L[i] = result

This can be rewritten using *note enumerate(): 1688. as:

     for i, item in enumerate(L):
         # ... compute some result based on item ...
         L[i] = result

Vedi anche
..........

PEP 279(1) - The enumerate() built-in function

     Written and implemented by Raymond D. Hettinger.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0279/


File: python.info,  Node: PEP 282 The logging Package,  Next: PEP 285 A Boolean Type,  Prev: PEP 279 enumerate,  Up: What’s New in Python 2 3

1.20.8 PEP 282: The logging Package
-----------------------------------

A standard package for writing logs, *note logging: 8b, has been added
to Python 2.3.  It provides a powerful and flexible mechanism for
generating logging output which can then be filtered and processed in
various ways.  A configuration file written in a standard format can be
used to control the logging behavior of a program.  Python includes
handlers that will write log records to standard error or to a file or
socket, send them to the system log, or even e-mail them to a particular
address; of course, it’s also possible to write your own handler
classes.

The *note Logger: d48. class is the primary class.  Most application
code will deal with one or more *note Logger: d48. objects, each one
used by a particular subsystem of the application.  Each *note Logger:
d48. is identified by a name, and names are organized into a hierarchy
using ‘.’ as the component separator.  For example, you might have *note
Logger: d48. instances named ‘server’, ‘server.auth’ and
‘server.network’.  The latter two instances are below ‘server’ in the
hierarchy.  This means that if you turn up the verbosity for ‘server’ or
direct ‘server’ messages to a different handler, the changes will also
apply to records logged to ‘server.auth’ and ‘server.network’.  There’s
also a root *note Logger: d48. that’s the parent of all other loggers.

For simple uses, the *note logging: 8b. package contains some
convenience functions that always use the root log:

     import logging

     logging.debug('Debugging information')
     logging.info('Informational message')
     logging.warning('Warning:config file %s not found', 'server.conf')
     logging.error('Error occurred')
     logging.critical('Critical error -- shutting down')

This produces the following output:

     WARNING:root:Warning:config file server.conf not found
     ERROR:root:Error occurred
     CRITICAL:root:Critical error -- shutting down

In the default configuration, informational and debugging messages are
suppressed and the output is sent to standard error.  You can enable the
display of informational and debugging messages by calling the *note
setLevel(): 169a. method on the root logger.

Notice the *note warning(): 354. call’s use of string formatting
operators; all of the functions for logging messages take the arguments
‘(msg, arg1, arg2, ...)’ and log the string resulting from ‘msg % (arg1,
arg2, ...)’.

There’s also an *note exception(): 169b. function that records the most
recent traceback.  Any of the other functions will also record the
traceback if you specify a true value for the keyword argument
'exc_info'.

     def f():
         try:    1/0
         except: logging.exception('Problem recorded')

     f()

This produces the following output:

     ERROR:root:Problem recorded
     Traceback (most recent call last):
       File "t.py", line 6, in f
         1/0
     ZeroDivisionError: integer division or modulo by zero

Slightly more advanced programs will use a logger other than the root
logger.  The ‘getLogger(name)’ function is used to get a particular log,
creating it if it doesn’t exist yet.  ‘getLogger(None)’ returns the root
logger.

     log = logging.getLogger('server')
      ...
     log.info('Listening on port %i', port)
      ...
     log.critical('Disk full')
      ...

Log records are usually propagated up the hierarchy, so a message logged
to ‘server.auth’ is also seen by ‘server’ and ‘root’, but a *note
Logger: d48. can prevent this by setting its *note propagate: 169c.
attribute to *note False: d2d.

There are more classes provided by the *note logging: 8b. package that
can be customized.  When a *note Logger: d48. instance is told to log a
message, it creates a *note LogRecord: 11e8. instance that is sent to
any number of different *note Handler: 169d. instances.  Loggers and
handlers can also have an attached list of filters, and each filter can
cause the *note LogRecord: 11e8. to be ignored or can modify the record
before passing it along.  When they’re finally output, *note LogRecord:
11e8. instances are converted to text by a *note Formatter: 169e. class.
All of these classes can be replaced by your own specially written
classes.

With all of these features the *note logging: 8b. package should provide
enough flexibility for even the most complicated applications.  This is
only an incomplete overview of its features, so please see the package’s
reference documentation for all of the details.  Reading PEP 282(1) will
also be helpful.

Vedi anche
..........

PEP 282(2) - A Logging System

     Written by Vinay Sajip and Trent Mick; implemented by Vinay Sajip.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0282/

   (2) https://peps.python.org/pep-0282/


File: python.info,  Node: PEP 285 A Boolean Type,  Next: PEP 293 Codec Error Handling Callbacks,  Prev: PEP 282 The logging Package,  Up: What’s New in Python 2 3

1.20.9 PEP 285: A Boolean Type
------------------------------

A Boolean type was added to Python 2.3.  Two new constants were added to
the ‘__builtin__’ module, *note True: e09. and *note False: d2d.  (*note
True: e09. and *note False: d2d. constants were added to the built-ins
in Python 2.2.1, but the 2.2.1 versions are simply set to integer values
of 1 and 0 and aren’t a different type.)

The type object for this new type is named *note bool: 3c3.; the
constructor for it takes any Python value and converts it to *note True:
e09. or *note False: d2d.

     >>> bool(1)
     True
     >>> bool(0)
     False
     >>> bool([])
     False
     >>> bool( (1,) )
     True

Most of the standard library modules and built-in functions have been
changed to return Booleans.

     >>> obj = []
     >>> hasattr(obj, 'append')
     True
     >>> isinstance(obj, list)
     True
     >>> isinstance(obj, tuple)
     False

Python’s Booleans were added with the primary goal of making code
clearer.  For example, if you’re reading a function and encounter the
statement ‘return 1’, you might wonder whether the ‘1’ represents a
Boolean truth value, an index, or a coefficient that multiplies some
other quantity.  If the statement is ‘return True’, however, the meaning
of the return value is quite clear.

Python’s Booleans were 'not' added for the sake of strict type-checking.
A very strict language such as Pascal would also prevent you performing
arithmetic with Booleans, and would require that the expression in an
*note if: 181. statement always evaluate to a Boolean result.  Python is
not this strict and never will be, as PEP 285(1) explicitly says.  This
means you can still use any expression in an ‘if’ statement, even ones
that evaluate to a list or tuple or some random object.  The Boolean
type is a subclass of the *note int: 19b. class so that arithmetic using
a Boolean still works.

     >>> True + 1
     2
     >>> False + 1
     1
     >>> False * 75
     0
     >>> True * 75
     75

To sum up *note True: e09. and *note False: d2d. in a sentence: they’re
alternative ways to spell the integer values 1 and 0, with the single
difference that *note str(): 169. and *note repr(): 1c1. return the
strings ‘'True'’ and ‘'False'’ instead of ‘'1'’ and ‘'0'’.

Vedi anche
..........

PEP 285(2) - Adding a bool type

     Written and implemented by GvR.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0285/

   (2) https://peps.python.org/pep-0285/


File: python.info,  Node: PEP 293 Codec Error Handling Callbacks,  Next: PEP 301 Package Index and Metadata for Distutils,  Prev: PEP 285 A Boolean Type,  Up: What’s New in Python 2 3

1.20.10 PEP 293: Codec Error Handling Callbacks
-----------------------------------------------

When encoding a Unicode string into a byte string, unencodable
characters may be encountered.  So far, Python has allowed specifying
the error processing as either «strict» (raising *note UnicodeError:
462.), «ignore» (skipping the character), or «replace» (using a question
mark in the output string), with «strict» being the default behavior.
It may be desirable to specify alternative processing of such errors,
such as inserting an XML character reference or HTML entity reference
into the converted string.

Python now has a flexible framework to add different processing
strategies.  New error handlers can be added with *note
codecs.register_error(): 16a2, and codecs then can access the error
handler with *note codecs.lookup_error(): 16a3.  An equivalent C API has
been added for codecs written in C. The error handler gets the necessary
state information such as the string being converted, the position in
the string where the error was detected, and the target encoding.  The
handler can then either raise an exception or return a replacement
string.

Two additional error handlers have been implemented using this
framework: «backslashreplace» uses Python backslash quoting to represent
unencodable characters and «xmlcharrefreplace» emits XML character
references.

Vedi anche
..........

PEP 293(1) - Codec Error Handling Callbacks

     Written and implemented by Walter Dörwald.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0293/


File: python.info,  Node: PEP 301 Package Index and Metadata for Distutils,  Next: PEP 302 New Import Hooks,  Prev: PEP 293 Codec Error Handling Callbacks,  Up: What’s New in Python 2 3

1.20.11 PEP 301: Package Index and Metadata for Distutils
---------------------------------------------------------

Support for the long-requested Python catalog makes its first appearance
in 2.3.

The heart of the catalog is the new Distutils ‘register’ command.
Running ‘python setup.py register’ will collect the metadata describing
a package, such as its name, version, maintainer, description, &c., and
send it to a central catalog server.  The resulting catalog is available
from ‘https://pypi.org’.

To make the catalog a bit more useful, a new optional 'classifiers'
keyword argument has been added to the Distutils ‘setup()’ function.  A
list of Trove(1)-style strings can be supplied to help classify the
software.

Here’s an example ‘setup.py’ with classifiers, written to be compatible
with older versions of the Distutils:

     from distutils import core
     kw = {'name': "Quixote",
           'version': "0.5.1",
           'description': "A highly Pythonic Web application framework",
           # ...
           }

     if (hasattr(core, 'setup_keywords') and
         'classifiers' in core.setup_keywords):
         kw['classifiers'] = \
             ['Topic :: Internet :: WWW/HTTP :: Dynamic Content',
              'Environment :: No Input/Output (Daemon)',
              'Intended Audience :: Developers'],

     core.setup(**kw)

The full list of classifiers can be obtained by running ‘python setup.py
register --list-classifiers’.

Vedi anche
..........

PEP 301(2) - Package Index and Metadata for Distutils

     Written and implemented by Richard Jones.

   ---------- Footnotes ----------

   (1) http://catb.org/~esr/trove/

   (2) https://peps.python.org/pep-0301/


File: python.info,  Node: PEP 302 New Import Hooks,  Next: PEP 305 Comma-separated Files,  Prev: PEP 301 Package Index and Metadata for Distutils,  Up: What’s New in Python 2 3

1.20.12 PEP 302: New Import Hooks
---------------------------------

While it’s been possible to write custom import hooks ever since the
‘ihooks’ module was introduced in Python 1.3, no one has ever been
really happy with it because writing new import hooks is difficult and
messy.  There have been various proposed alternatives such as the
‘imputil’ and ‘iu’ modules, but none of them has ever gained much
acceptance, and none of them were easily usable from C code.

PEP 302(1) borrows ideas from its predecessors, especially from Gordon
McMillan’s ‘iu’ module.  Three new items are added to the *note sys: df.
module:

   * ‘sys.path_hooks’ is a list of callable objects; most often they’ll
     be classes.  Each callable takes a string containing a path and
     either returns an importer object that will handle imports from
     this path or raises an *note ImportError: 65b. exception if it
     can’t handle this path.

   * ‘sys.path_importer_cache’ caches importer objects for each path, so
     ‘sys.path_hooks’ will only need to be traversed once for each path.

   * ‘sys.meta_path’ is a list of importer objects that will be
     traversed before ‘sys.path’ is checked.  This list is initially
     empty, but user code can add objects to it.  Additional built-in
     and frozen modules can be imported by an object added to this list.

Importer objects must have a single method, ‘find_module(fullname,
path=None)’.  'fullname' will be a module or package name, e.g.
‘string’ or ‘distutils.core’.  ‘find_module()’ must return a loader
object that has a single method, ‘load_module(fullname)’, that creates
and returns the corresponding module object.

Pseudo-code for Python’s new import logic, therefore, looks something
like this (simplified a bit; see PEP 302(2) for the full details):

     for mp in sys.meta_path:
         loader = mp(fullname)
         if loader is not None:
             <module> = loader.load_module(fullname)

     for path in sys.path:
         for hook in sys.path_hooks:
             try:
                 importer = hook(path)
             except ImportError:
                 # ImportError, so try the other path hooks
                 pass
             else:
                 loader = importer.find_module(fullname)
                 <module> = loader.load_module(fullname)

     # Not found!
     raise ImportError

Vedi anche
..........

PEP 302(3) - New Import Hooks

     Written by Just van Rossum and Paul Moore.  Implemented by Just van
     Rossum.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0302/

   (2) https://peps.python.org/pep-0302/

   (3) https://peps.python.org/pep-0302/


File: python.info,  Node: PEP 305 Comma-separated Files,  Next: PEP 307 Pickle Enhancements,  Prev: PEP 302 New Import Hooks,  Up: What’s New in Python 2 3

1.20.13 PEP 305: Comma-separated Files
--------------------------------------

Comma-separated files are a format frequently used for exporting data
from databases and spreadsheets.  Python 2.3 adds a parser for
comma-separated files.

Comma-separated format is deceptively simple at first glance:

     Costs,150,200,3.95

Read a line and call ‘line.split(',')’: what could be simpler?  But toss
in string data that can contain commas, and things get more complicated:

     "Costs",150,200,3.95,"Includes taxes, shipping, and sundry items"

A big ugly regular expression can parse this, but using the new *note
csv: 2d. package is much simpler:

     import csv

     input = open('datafile', 'rb')
     reader = csv.reader(input)
     for line in reader:
         print line

The *note reader(): 6af. function takes a number of different options.
The field separator isn’t limited to the comma and can be changed to any
character, and so can the quoting and line-ending characters.

Different dialects of comma-separated files can be defined and
registered; currently there are two dialects, both used by Microsoft
Excel.  A separate *note csv.writer: 6b0. class will generate
comma-separated files from a succession of tuples or lists, quoting
strings that contain the delimiter.

Vedi anche
..........

PEP 305(1) - CSV File API

     Written and implemented by Kevin Altis, Dave Cole, Andrew McNamara,
     Skip Montanaro, Cliff Wells.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0305/


File: python.info,  Node: PEP 307 Pickle Enhancements,  Next: Extended Slices,  Prev: PEP 305 Comma-separated Files,  Up: What’s New in Python 2 3

1.20.14 PEP 307: Pickle Enhancements
------------------------------------

The *note pickle: ab. and ‘cPickle’ modules received some attention
during the 2.3 development cycle.  In 2.2, new-style classes could be
pickled without difficulty, but they weren’t pickled very compactly; PEP
307(1) quotes a trivial example where a new-style class results in a
pickled string three times longer than that for a classic class.

The solution was to invent a new pickle protocol.  The *note
pickle.dumps(): 16ab. function has supported a text-or-binary flag for a
long time.  In 2.3, this flag is redefined from a Boolean to an integer:
0 is the old text-mode pickle format, 1 is the old binary format, and
now 2 is a new 2.3-specific format.  A new constant, *note
pickle.HIGHEST_PROTOCOL: 16ac, can be used to select the fanciest
protocol available.

Unpickling is no longer considered a safe operation.  2.2’s *note
pickle: ab. provided hooks for trying to prevent unsafe classes from
being unpickled (specifically, a ‘__safe_for_unpickling__’ attribute),
but none of this code was ever audited and therefore it’s all been
ripped out in 2.3.  You should not unpickle untrusted data in any
version of Python.

To reduce the pickling overhead for new-style classes, a new interface
for customizing pickling was added using three special methods: *note
__getstate__(): 7f2, *note __setstate__(): bc9, and *note
__getnewargs__(): fd6.  Consult PEP 307(2) for the full semantics of
these methods.

As a way to compress pickles yet further, it’s now possible to use
integer codes instead of long strings to identify pickled classes.  The
Python Software Foundation will maintain a list of standardized codes;
there’s also a range of codes for private use.  Currently no codes have
been specified.

Vedi anche
..........

PEP 307(3) - Extensions to the pickle protocol

     Written and implemented by Guido van Rossum and Tim Peters.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0307/

   (2) https://peps.python.org/pep-0307/

   (3) https://peps.python.org/pep-0307/


File: python.info,  Node: Extended Slices,  Next: Other Language Changes<17>,  Prev: PEP 307 Pickle Enhancements,  Up: What’s New in Python 2 3

1.20.15 Extended Slices
-----------------------

Ever since Python 1.4, the slicing syntax has supported an optional
third «step» or «stride» argument.  For example, these are all legal
Python syntax: ‘L[1:10:2]’, ‘L[:-1:1]’, ‘L[::-1]’.  This was added to
Python at the request of the developers of Numerical Python, which uses
the third argument extensively.  However, Python’s built-in list, tuple,
and string sequence types have never supported this feature, raising a
*note TypeError: 198. if you tried it.  Michael Hudson contributed a
patch to fix this shortcoming.

For example, you can now easily extract the elements of a list that have
even indexes:

     >>> L = range(10)
     >>> L[::2]
     [0, 2, 4, 6, 8]

Negative values also work to make a copy of the same list in reverse
order:

     >>> L[::-1]
     [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]

This also works for tuples, arrays, and strings:

     >>> s='abcd'
     >>> s[::2]
     'ac'
     >>> s[::-1]
     'dcba'

If you have a mutable sequence such as a list or an array you can assign
to or delete an extended slice, but there are some differences between
assignment to extended and regular slices.  Assignment to a regular
slice can be used to change the length of the sequence:

     >>> a = range(3)
     >>> a
     [0, 1, 2]
     >>> a[1:3] = [4, 5, 6]
     >>> a
     [0, 4, 5, 6]

Extended slices aren’t this flexible.  When assigning to an extended
slice, the list on the right hand side of the statement must contain the
same number of items as the slice it is replacing:

     >>> a = range(4)
     >>> a
     [0, 1, 2, 3]
     >>> a[::2]
     [0, 2]
     >>> a[::2] = [0, -1]
     >>> a
     [0, 1, -1, 3]
     >>> a[::2] = [0,1,2]
     Traceback (most recent call last):
       File "<stdin>", line 1, in ?
     ValueError: attempt to assign sequence of size 3 to extended slice of size 2

Deletion is more straightforward:

     >>> a = range(4)
     >>> a
     [0, 1, 2, 3]
     >>> a[::2]
     [0, 2]
     >>> del a[::2]
     >>> a
     [1, 3]

One can also now pass slice objects to the *note __getitem__(): 588.
methods of the built-in sequences:

     >>> range(10).__getitem__(slice(0, 5, 2))
     [0, 2, 4]

Or use slice objects directly in subscripts:

     >>> range(10)[slice(0, 5, 2)]
     [0, 2, 4]

To simplify implementing sequences that support extended slicing, slice
objects now have a method ‘indices(length)’ which, given the length of a
sequence, returns a ‘(start, stop, step)’ tuple that can be passed
directly to *note range(): b3f.  ‘indices()’ handles omitted and
out-of-bounds indices in a manner consistent with regular slices (and
this innocuous phrase hides a welter of confusing details!).  The method
is intended to be used like this:

     class FakeSeq:
         ...
         def calc_item(self, i):
             ...
         def __getitem__(self, item):
             if isinstance(item, slice):
                 indices = item.indices(len(self))
                 return FakeSeq([self.calc_item(i) for i in range(*indices)])
             else:
                 return self.calc_item(i)

From this example you can also see that the built-in *note slice: 695.
object is now the type object for the slice type, and is no longer a
function.  This is consistent with Python 2.2, where *note int: 19b,
*note str: 169, etc., underwent the same change.


File: python.info,  Node: Other Language Changes<17>,  Next: New Improved and Deprecated Modules<4>,  Prev: Extended Slices,  Up: What’s New in Python 2 3

1.20.16 Other Language Changes
------------------------------

Here are all of the changes that Python 2.3 makes to the core Python
language.

   * The *note yield: bc4. statement is now always a keyword, as
     described in section *note PEP 255; Simple Generators: 168f. of
     this document.

   * A new built-in function *note enumerate(): 1688. was added, as
     described in section *note PEP 279; enumerate(): 1698. of this
     document.

   * Two new constants, *note True: e09. and *note False: d2d. were
     added along with the built-in *note bool: 3c3. type, as described
     in section *note PEP 285; A Boolean Type: 16a0. of this document.

   * The *note int(): 19b. type constructor will now return a long
     integer instead of raising an *note OverflowError: a83. when a
     string or floating-point number is too large to fit into an
     integer.  This can lead to the paradoxical result that
     ‘isinstance(int(expression), int)’ is false, but that seems
     unlikely to cause problems in practice.

   * Built-in types now support the extended slicing syntax, as
     described in section *note Extended Slices: 16ae. of this document.

   * A new built-in function, ‘sum(iterable, start=0)’, adds up the
     numeric items in the iterable object and returns their sum.  *note
     sum(): 696. only accepts numbers, meaning that you can’t use it to
     concatenate a bunch of strings.  (Contributed by Alex Martelli.)

   * ‘list.insert(pos, value)’ used to insert 'value' at the front of
     the list when 'pos' was negative.  The behaviour has now been
     changed to be consistent with slice indexing, so when 'pos' is -1
     the value will be inserted before the last element, and so forth.

   * ‘list.index(value)’, which searches for 'value' within the list and
     returns its index, now takes optional 'start' and 'stop' arguments
     to limit the search to only part of the list.

   * Dictionaries have a new method, ‘pop(key[, *default*])’, that
     returns the value corresponding to 'key' and removes that key/value
     pair from the dictionary.  If the requested key isn’t present in
     the dictionary, 'default' is returned if it’s specified and *note
     KeyError: 5e7. raised if it isn’t.

          >>> d = {1:2}
          >>> d
          {1: 2}
          >>> d.pop(4)
          Traceback (most recent call last):
            File "stdin", line 1, in ?
          KeyError: 4
          >>> d.pop(1)
          2
          >>> d.pop(1)
          Traceback (most recent call last):
            File "stdin", line 1, in ?
          KeyError: 'pop(): dictionary is empty'
          >>> d
          {}
          >>>

     There’s also a new class method, ‘dict.fromkeys(iterable, value)’,
     that creates a dictionary with keys taken from the supplied
     iterator 'iterable' and all values set to 'value', defaulting to
     ‘None’.

     (Patches contributed by Raymond Hettinger.)

     Also, the *note dict(): 183. constructor now accepts keyword
     arguments to simplify creating small dictionaries:

          >>> dict(red=1, blue=2, green=3, black=4)
          {'blue': 2, 'black': 4, 'green': 3, 'red': 1}

     (Contributed by Just van Rossum.)

   * The *note assert: b62. statement no longer checks the ‘__debug__’
     flag, so you can no longer disable assertions by assigning to
     ‘__debug__’.  Running Python with the *note -O: 18c. switch will
     still generate code that doesn’t execute any assertions.

   * Most type objects are now callable, so you can use them to create
     new objects such as functions, classes, and modules.  (This means
     that the ‘new’ module can be deprecated in a future Python version,
     because you can now use the type objects available in the *note
     types: 109. module.)  For example, you can create a new module
     object with the following code:

          >>> import types
          >>> m = types.ModuleType('abc','docstring')
          >>> m
          <module 'abc' (built-in)>
          >>> m.__doc__
          'docstring'

   * A new warning, *note PendingDeprecationWarning: ac8. was added to
     indicate features which are in the process of being deprecated.
     The warning will 'not' be printed by default.  To check for use of
     features that will be deprecated in the future, supply *note
     -Walways;;PendingDeprecationWarning;;: ac7. on the command line or
     use *note warnings.filterwarnings(): 16b0.

   * The process of deprecating string-based exceptions, as in ‘raise
     "Error occurred"’, has begun.  Raising a string will now trigger
     *note PendingDeprecationWarning: ac8.

   * Using ‘None’ as a variable name will now result in a *note
     SyntaxWarning: 1ae. warning.  In a future version of Python, ‘None’
     may finally become a keyword.

   * The ‘xreadlines()’ method of file objects, introduced in Python
     2.1, is no longer necessary because files now behave as their own
     iterator.  ‘xreadlines()’ was originally introduced as a faster way
     to loop over all the lines in a file, but now you can simply write
     ‘for line in file_obj’.  File objects also have a new read-only
     ‘encoding’ attribute that gives the encoding used by the file;
     Unicode strings written to the file will be automatically converted
     to bytes using the given encoding.

   * The method resolution order used by new-style classes has changed,
     though you’ll only notice the difference if you have a really
     complicated inheritance hierarchy.  Classic classes are unaffected
     by this change.  Python 2.2 originally used a topological sort of a
     class’s ancestors, but 2.3 now uses the C3 algorithm as described
     in the paper "A Monotonic Superclass Linearization for Dylan"(1).
     To understand the motivation for this change, read Michele
     Simionato’s article *note The Python 2.3 Method Resolution Order:
     16b1, or read the thread on python-dev starting with the message at
     ‘https://mail.python.org/pipermail/python-dev/2002-October/029035.html’.
     Samuele Pedroni first pointed out the problem and also implemented
     the fix by coding the C3 algorithm.

   * Python runs multithreaded programs by switching between threads
     after executing N bytecodes.  The default value for N has been
     increased from 10 to 100 bytecodes, speeding up single-threaded
     applications by reducing the switching overhead.  Some
     multithreaded applications may suffer slower response time, but
     that’s easily fixed by setting the limit back to a lower number
     using ‘sys.setcheckinterval(N)’.  The limit can be retrieved with
     the new ‘sys.getcheckinterval()’ function.

   * One minor but far-reaching change is that the names of extension
     types defined by the modules included with Python now contain the
     module and a ‘'.'’ in front of the type name.  For example, in
     Python 2.2, if you created a socket and printed its ‘__class__’,
     you’d get this output:

          >>> s = socket.socket()
          >>> s.__class__
          <type 'socket'>

     In 2.3, you get this:

          >>> s.__class__
          <type '_socket.socket'>

   * One of the noted incompatibilities between old- and new-style
     classes has been removed: you can now assign to the *note __name__:
     16b2. and *note __bases__: 16b3. attributes of new-style classes.
     There are some restrictions on what can be assigned to ‘__bases__’
     along the lines of those relating to assigning to an instance’s
     *note __class__: 16b4. attribute.

* Menu:

* String Changes::
* Optimizations: Optimizations<17>.

   ---------- Footnotes ----------

   (1) https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.19.3910


File: python.info,  Node: String Changes,  Next: Optimizations<17>,  Up: Other Language Changes<17>

1.20.16.1 String Changes
........................

   * The *note in: 34b. operator now works differently for strings.
     Previously, when evaluating ‘X in Y’ where 'X' and 'Y' are strings,
     'X' could only be a single character.  That’s now changed; 'X' can
     be a string of any length, and ‘X in Y’ will return *note True:
     e09. if 'X' is a substring of 'Y'. If 'X' is the empty string, the
     result is always *note True: e09.

          >>> 'ab' in 'abcd'
          True
          >>> 'ad' in 'abcd'
          False
          >>> '' in 'abcd'
          True

     Note that this doesn’t tell you where the substring starts; if you
     need that information, use the *note find(): 10aa. string method.

   * The *note strip(): 16b6, *note lstrip(): 16b7, and *note rstrip():
     16b8. string methods now have an optional argument for specifying
     the characters to strip.  The default is still to remove all
     whitespace characters:

          >>> '   abc '.strip()
          'abc'
          >>> '><><abc<><><>'.strip('<>')
          'abc'
          >>> '><><abc<><><>\n'.strip('<>')
          'abc<><><>\n'
          >>> u'\u4000\u4001abc\u4000'.strip(u'\u4000')
          u'\u4001abc'
          >>>

     (Suggested by Simon Brunning and implemented by Walter Dörwald.)

   * The *note startswith(): 10cd. and *note endswith(): 10ce. string
     methods now accept negative numbers for the 'start' and 'end'
     parameters.

   * Another new string method is *note zfill(): 16b9, originally a
     function in the *note string: d8. module.  *note zfill(): 16b9.
     pads a numeric string with zeros on the left until it’s the
     specified width.  Note that the ‘%’ operator is still more flexible
     and powerful than *note zfill(): 16b9.

          >>> '45'.zfill(4)
          '0045'
          >>> '12345'.zfill(4)
          '12345'
          >>> 'goofy'.zfill(6)
          '0goofy'

     (Contributed by Walter Dörwald.)

   * A new type object, ‘basestring’, has been added.  Both 8-bit
     strings and Unicode strings inherit from this type, so
     ‘isinstance(obj, basestring)’ will return *note True: e09. for
     either kind of string.  It’s a completely abstract type, so you
     can’t create ‘basestring’ instances.

   * Interned strings are no longer immortal and will now be
     garbage-collected in the usual way when the only reference to them
     is from the internal dictionary of interned strings.  (Implemented
     by Oren Tirosh.)


File: python.info,  Node: Optimizations<17>,  Prev: String Changes,  Up: Other Language Changes<17>

1.20.16.2 Optimizations
.......................

   * The creation of new-style class instances has been made much
     faster; they’re now faster than classic classes!

   * The *note sort(): dca. method of list objects has been extensively
     rewritten by Tim Peters, and the implementation is significantly
     faster.

   * Multiplication of large long integers is now much faster thanks to
     an implementation of Karatsuba multiplication, an algorithm that
     scales better than the 'O'('n'^2) required for the grade-school
     multiplication algorithm.  (Original patch by Christopher A. Craig,
     and significantly reworked by Tim Peters.)

   * The ‘SET_LINENO’ opcode is now gone.  This may provide a small
     speed increase, depending on your compiler’s idiosyncrasies.  See
     section *note Other Changes and Fixes: 16bb. for a longer
     explanation.  (Removed by Michael Hudson.)

   * ‘xrange()’ objects now have their own iterator, making ‘for i in
     xrange(n)’ slightly faster than ‘for i in range(n)’.  (Patch by
     Raymond Hettinger.)

   * A number of small rearrangements have been made in various hotspots
     to improve performance, such as inlining a function or removing
     some code.  (Implemented mostly by GvR, but lots of people have
     contributed single changes.)

The net result of the 2.3 optimizations is that Python 2.3 runs the
pystone benchmark around 25% faster than Python 2.2.


File: python.info,  Node: New Improved and Deprecated Modules<4>,  Next: Pymalloc A Specialized Object Allocator,  Prev: Other Language Changes<17>,  Up: What’s New in Python 2 3

1.20.17 New, Improved, and Deprecated Modules
---------------------------------------------

As usual, Python’s standard library received a number of enhancements
and bug fixes.  Here’s a partial list of the most notable changes,
sorted alphabetically by module name.  Consult the ‘Misc/NEWS’ file in
the source tree for a more complete list of changes, or look through the
CVS logs for all the details.

   * The *note array: 8. module now supports arrays of Unicode
     characters using the ‘'u'’ format character.  Arrays also now
     support using the ‘+=’ assignment operator to add another array’s
     contents, and the ‘*=’ assignment operator to repeat an array.
     (Contributed by Jason Orendorff.)

   * The ‘bsddb’ module has been replaced by version 4.1.6 of the
     PyBSDDB(1) package, providing a more complete interface to the
     transactional features of the BerkeleyDB library.

     The old version of the module has been renamed to ‘bsddb185’ and is
     no longer built automatically; you’ll have to edit ‘Modules/Setup’
     to enable it.  Note that the new ‘bsddb’ package is intended to be
     compatible with the old module, so be sure to file bugs if you
     discover any incompatibilities.  When upgrading to Python 2.3, if
     the new interpreter is compiled with a new version of the
     underlying BerkeleyDB library, you will almost certainly have to
     convert your database files to the new version.  You can do this
     fairly easily with the new scripts ‘db2pickle.py’ and
     ‘pickle2db.py’ which you will find in the distribution’s
     ‘Tools/scripts’ directory.  If you’ve already been using the
     PyBSDDB package and importing it as ‘bsddb3’, you will have to
     change your ‘import’ statements to import it as ‘bsddb’.

   * The new *note bz2: 14. module is an interface to the bz2 data
     compression library.  bz2-compressed data is usually smaller than
     corresponding *note zlib: 139.-compressed data.  (Contributed by
     Gustavo Niemeyer.)

   * A set of standard date/time types has been added in the new *note
     datetime: 34. module.  See the following section for more details.

   * The Distutils ‘Extension’ class now supports an extra constructor
     argument named 'depends' for listing additional source files that
     an extension depends on.  This lets Distutils recompile the module
     if any of the dependency files are modified.  For example, if
     ‘sampmodule.c’ includes the header file ‘sample.h’, you would
     create the ‘Extension’ object like this:

          ext = Extension("samp",
                          sources=["sampmodule.c"],
                          depends=["sample.h"])

     Modifying ‘sample.h’ would then cause the module to be recompiled.
     (Contributed by Jeremy Hylton.)

   * Other minor changes to Distutils: it now checks for the *note CC:
     16bd, *note CFLAGS: 16be, ‘CPP’, *note LDFLAGS: 16bf, and *note
     CPPFLAGS: 16c0. environment variables, using them to override the
     settings in Python’s configuration (contributed by Robert Weber).

   * Previously the *note doctest: 3e. module would only search the
     docstrings of public methods and functions for test cases, but it
     now also examines private ones as well.  The *note DocTestSuite():
     ff6. function creates a *note unittest.TestSuite: ff7. object from
     a set of *note doctest: 3e. tests.

   * The new ‘gc.get_referents(object)’ function returns a list of all
     the objects referenced by 'object'.

   * The *note getopt: 65. module gained a new function, *note
     gnu_getopt(): 16c1, that supports the same arguments as the
     existing *note getopt(): 16c2. function but uses GNU-style scanning
     mode.  The existing *note getopt(): 16c2. stops processing options
     as soon as a non-option argument is encountered, but in GNU-style
     mode processing continues, meaning that options and arguments can
     be mixed.  For example:

          >>> getopt.getopt(['-f', 'filename', 'output', '-v'], 'f:v')
          ([('-f', 'filename')], ['output', '-v'])
          >>> getopt.gnu_getopt(['-f', 'filename', 'output', '-v'], 'f:v')
          ([('-f', 'filename'), ('-v', '')], ['output'])

     (Contributed by Peter Åstrand.)

   * The *note grp: 6a, *note pwd: b7, and *note resource: c1. modules
     now return enhanced tuples:

          >>> import grp
          >>> g = grp.getgrnam('amk')
          >>> g.gr_name, g.gr_gid
          ('amk', 500)

   * The *note gzip: 6b. module can now handle files exceeding 2 GiB.

   * The new *note heapq: 6d. module contains an implementation of a
     heap queue algorithm.  A heap is an array-like data structure that
     keeps items in a partially sorted order such that, for every index
     'k', ‘heap[k] <= heap[2*k+1]’ and ‘heap[k] <= heap[2*k+2]’.  This
     makes it quick to remove the smallest item, and inserting a new
     item while maintaining the heap property is 'O'(log 'n').  (See
     ‘https://xlinux.nist.gov/dads//HTML/priorityque.html’ for more
     information about the priority queue data structure.)

     The *note heapq: 6d. module provides *note heappush(): 16c3. and
     *note heappop(): 16c4. functions for adding and removing items
     while maintaining the heap property on top of some other mutable
     Python sequence type.  Here’s an example that uses a Python list:

          >>> import heapq
          >>> heap = []
          >>> for item in [3, 7, 5, 11, 1]:
          ...    heapq.heappush(heap, item)
          ...
          >>> heap
          [1, 3, 5, 11, 7]
          >>> heapq.heappop(heap)
          1
          >>> heapq.heappop(heap)
          3
          >>> heap
          [5, 7, 11]

     (Contributed by Kevin O’Connor.)

   * The IDLE integrated development environment has been updated using
     the code from the IDLEfork project
     (‘https://idlefork.sourceforge.net’).  The most notable feature is
     that the code being developed is now executed in a subprocess,
     meaning that there’s no longer any need for manual ‘reload()’
     operations.  IDLE’s core code has been incorporated into the
     standard library as the *note idlelib: 77. package.

   * The *note imaplib: 78. module now supports IMAP over SSL.
     (Contributed by Piers Lauder and Tino Lange.)

   * The *note itertools: 85. contains a number of useful functions for
     use with iterators, inspired by various functions provided by the
     ML and Haskell languages.  For example,
     ‘itertools.ifilter(predicate, iterator)’ returns all elements in
     the iterator for which the function ‘predicate()’ returns *note
     True: e09, and ‘itertools.repeat(obj, N)’ returns ‘obj’ 'N' times.
     There are a number of other functions in the module; see the
     package’s reference documentation for details.  (Contributed by
     Raymond Hettinger.)

   * Two new functions in the *note math: 92. module, ‘degrees(rads)’
     and ‘radians(degs)’, convert between radians and degrees.  Other
     functions in the *note math: 92. module such as *note math.sin():
     16c5. and *note math.cos(): 16c6. have always required input values
     measured in radians.  Also, an optional 'base' argument was added
     to *note math.log(): 16c7. to make it easier to compute logarithms
     for bases other than ‘e’ and ‘10’.  (Contributed by Raymond
     Hettinger.)

   * Several new POSIX functions (‘getpgid()’, ‘killpg()’, ‘lchown()’,
     ‘loadavg()’, ‘major()’, ‘makedev()’, ‘minor()’, and ‘mknod()’) were
     added to the *note posix: b2. module that underlies the *note os:
     a5. module.  (Contributed by Gustavo Niemeyer, Geert Jansen, and
     Denis S. Otkidach.)

   * In the *note os: a5. module, the ‘*stat()’ family of functions can
     now report fractions of a second in a timestamp.  Such time stamps
     are represented as floats, similar to the value returned by *note
     time.time(): 55d.

     During testing, it was found that some applications will break if
     time stamps are floats.  For compatibility, when using the tuple
     interface of the *note stat_result: 16c8. time stamps will be
     represented as integers.  When using named fields (a feature first
     introduced in Python 2.2), time stamps are still represented as
     integers, unless ‘os.stat_float_times()’ is invoked to enable float
     return values:

          >>> os.stat("/tmp").st_mtime
          1034791200
          >>> os.stat_float_times(True)
          >>> os.stat("/tmp").st_mtime
          1034791200.6335014

     In Python 2.4, the default will change to always returning floats.

     Application developers should enable this feature only if all their
     libraries work properly when confronted with floating-point time
     stamps, or if they use the tuple API. If used, the feature should
     be activated on an application level instead of trying to enable it
     on a per-use basis.

   * The *note optparse: a4. module contains a new parser for
     command-line arguments that can convert option values to a
     particular Python type and will automatically generate a usage
     message.  See the following section for more details.

   * The old and never-documented ‘linuxaudiodev’ module has been
     deprecated, and a new version named ‘ossaudiodev’ has been added.
     The module was renamed because the OSS sound drivers can be used on
     platforms other than Linux, and the interface has also been tidied
     and brought up to date in various ways.  (Contributed by Greg Ward
     and Nicholas FitzRoy-Dale.)

   * The new *note platform: af. module contains a number of functions
     that try to determine various properties of the platform you’re
     running on.  There are functions for getting the architecture, CPU
     type, the Windows OS version, and even the Linux distribution
     version.  (Contributed by Marc-André Lemburg.)

   * The parser objects provided by the *note pyexpat: 12c. module can
     now optionally buffer character data, resulting in fewer calls to
     your character data handler and therefore faster performance.
     Setting the parser object’s *note buffer_text: 16c9. attribute to
     *note True: e09. will enable buffering.

   * The ‘sample(population, k)’ function was added to the *note random:
     bd. module.  'population' is a sequence or ‘xrange’ object
     containing the elements of a population, and *note sample(): 94e.
     chooses 'k' elements from the population without replacing chosen
     elements.  'k' can be any value up to ‘len(population)’.  For
     example:

          >>> days = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'St', 'Sn']
          >>> random.sample(days, 3)      # Choose 3 elements
          ['St', 'Sn', 'Th']
          >>> random.sample(days, 7)      # Choose 7 elements
          ['Tu', 'Th', 'Mo', 'We', 'St', 'Fr', 'Sn']
          >>> random.sample(days, 7)      # Choose 7 again
          ['We', 'Mo', 'Sn', 'Fr', 'Tu', 'St', 'Th']
          >>> random.sample(days, 8)      # Can't choose eight
          Traceback (most recent call last):
            File "<stdin>", line 1, in ?
            File "random.py", line 414, in sample
                raise ValueError, "sample larger than population"
          ValueError: sample larger than population
          >>> random.sample(xrange(1,10000,2), 10)   # Choose ten odd nos. under 10000
          [3407, 3805, 1505, 7023, 2401, 2267, 9733, 3151, 8083, 9195]

     The *note random: bd. module now uses a new algorithm, the Mersenne
     Twister, implemented in C. It’s faster and more extensively studied
     than the previous algorithm.

     (All changes contributed by Raymond Hettinger.)

   * The *note readline: bf. module also gained a number of new
     functions: *note get_history_item(): 16ca, *note
     get_current_history_length(): 16cb, and *note redisplay(): 16cc.

   * The ‘rexec’ and ‘Bastion’ modules have been declared dead, and
     attempts to import them will fail with a *note RuntimeError: 244.
     New-style classes provide new ways to break out of the restricted
     execution environment provided by ‘rexec’, and no one has interest
     in fixing them or time to do so.  If you have applications using
     ‘rexec’, rewrite them to use something else.

     (Sticking with Python 2.2 or 2.1 will not make your applications
     any safer because there are known bugs in the ‘rexec’ module in
     those versions.  To repeat: if you’re using ‘rexec’, stop using it
     immediately.)

   * The ‘rotor’ module has been deprecated because the algorithm it
     uses for encryption is not believed to be secure.  If you need
     encryption, use one of the several AES Python modules that are
     available separately.

   * The *note shutil: ca. module gained a ‘move(src, dest)’ function
     that recursively moves a file or directory to a new location.

   * Support for more advanced POSIX signal handling was added to the
     *note signal: cb. but then removed again as it proved impossible to
     make it work reliably across platforms.

   * The *note socket: d1. module now supports timeouts.  You can call
     the ‘settimeout(t)’ method on a socket object to set a timeout of
     't' seconds.  Subsequent socket operations that take longer than
     't' seconds to complete will abort and raise a *note
     socket.timeout: a37. exception.

     The original timeout implementation was by Tim O’Malley.  Michael
     Gilfix integrated it into the Python *note socket: d1. module and
     shepherded it through a lengthy review.  After the code was checked
     in, Guido van Rossum rewrote parts of it.  (This is a good example
     of a collaborative development process in action.)

   * On Windows, the *note socket: d1. module now ships with Secure
     Sockets Layer (SSL) support.

   * The value of the C ‘PYTHON_API_VERSION’ macro is now exposed at the
     Python level as ‘sys.api_version’.  The current exception can be
     cleared by calling the new ‘sys.exc_clear()’ function.

   * The new *note tarfile: e4. module allows reading from and writing
     to ‘tar’-format archive files.  (Contributed by Lars Gustäbel.)

   * The new *note textwrap: f2. module contains functions for wrapping
     strings containing paragraphs of text.  The ‘wrap(text, width)’
     function takes a string and returns a list containing the text
     split into lines of no more than the chosen width.  The ‘fill(text,
     width)’ function returns a single string, reformatted to fit into
     lines no longer than the chosen width.  (As you can guess, *note
     fill(): 16cd. is built on top of *note wrap(): 16ce.  For example:

          >>> import textwrap
          >>> paragraph = "Not a whit, we defy augury: ... more text ..."
          >>> textwrap.wrap(paragraph, 60)
          ["Not a whit, we defy augury: there's a special providence in",
           "the fall of a sparrow. If it be now, 'tis not to come; if it",
           ...]
          >>> print textwrap.fill(paragraph, 35)
          Not a whit, we defy augury: there's
          a special providence in the fall of
          a sparrow. If it be now, 'tis not
          to come; if it be not to come, it
          will be now; if it be not now, yet
          it will come: the readiness is all.
          >>>

     The module also contains a *note TextWrapper: 11cf. class that
     actually implements the text wrapping strategy.  Both the *note
     TextWrapper: 11cf. class and the *note wrap(): 16ce. and *note
     fill(): 16cd. functions support a number of additional keyword
     arguments for fine-tuning the formatting; consult the module’s
     documentation for details.  (Contributed by Greg Ward.)

   * The ‘thread’ and *note threading: f3. modules now have companion
     modules, ‘dummy_thread’ and ‘dummy_threading’, that provide a
     do-nothing implementation of the ‘thread’ module’s interface for
     platforms where threads are not supported.  The intention is to
     simplify thread-aware modules (ones that 'don’t' rely on threads to
     run) by putting the following code at the top:

          try:
              import threading as _threading
          except ImportError:
              import dummy_threading as _threading

     In this example, ‘_threading’ is used as the module name to make it
     clear that the module being used is not necessarily the actual
     *note threading: f3. module.  Code can call functions and use
     classes in ‘_threading’ whether or not threads are supported,
     avoiding an *note if: 181. statement and making the code slightly
     clearer.  This module will not magically make multithreaded code
     run without threads; code that waits for another thread to return
     or to do something will simply hang forever.

   * The *note time: f4. module’s *note strptime(): 1634. function has
     long been an annoyance because it uses the platform C library’s
     *note strptime(): 1634. implementation, and different platforms
     sometimes have odd bugs.  Brett Cannon contributed a portable
     implementation that’s written in pure Python and should behave
     identically on all platforms.

   * The new *note timeit: f5. module helps measure how long snippets of
     Python code take to execute.  The ‘timeit.py’ file can be run
     directly from the command line, or the module’s *note Timer: 16cf.
     class can be imported and used directly.  Here’s a short example
     that figures out whether it’s faster to convert an 8-bit string to
     Unicode by appending an empty Unicode string to it or by using the
     ‘unicode()’ function:

          import timeit

          timer1 = timeit.Timer('unicode("abc")')
          timer2 = timeit.Timer('"abc" + u""')

          # Run three trials
          print timer1.repeat(repeat=3, number=100000)
          print timer2.repeat(repeat=3, number=100000)

          # On my laptop this outputs:
          # [0.36831796169281006, 0.37441694736480713, 0.35304892063140869]
          # [0.17574405670166016, 0.18193507194519043, 0.17565798759460449]

   * The ‘Tix’ module has received various bug fixes and updates for the
     current version of the Tix package.

   * The ‘Tkinter’ module now works with a thread-enabled version of
     Tcl.  Tcl’s threading model requires that widgets only be accessed
     from the thread in which they’re created; accesses from another
     thread can cause Tcl to panic.  For certain Tcl interfaces,
     ‘Tkinter’ will now automatically avoid this when a widget is
     accessed from a different thread by marshalling a command, passing
     it to the correct thread, and waiting for the results.  Other
     interfaces can’t be handled automatically but ‘Tkinter’ will now
     raise an exception on such an access so that you can at least find
     out about the problem.  See
     ‘https://mail.python.org/pipermail/python-dev/2002-December/031107.html’
     for a more detailed explanation of this change.  (Implemented by
     Martin von Löwis.)

   * Calling Tcl methods through ‘_tkinter’ no longer returns only
     strings.  Instead, if Tcl returns other objects those objects are
     converted to their Python equivalent, if one exists, or wrapped
     with a ‘_tkinter.Tcl_Obj’ object if no Python equivalent exists.
     This behavior can be controlled through the ‘wantobjects()’ method
     of ‘tkapp’ objects.

     When using ‘_tkinter’ through the ‘Tkinter’ module (as most Tkinter
     applications will), this feature is always activated.  It should
     not cause compatibility problems, since Tkinter would always
     convert string results to Python types where possible.

     If any incompatibilities are found, the old behavior can be
     restored by setting the ‘wantobjects’ variable in the ‘Tkinter’
     module to false before creating the first ‘tkapp’ object.

          import Tkinter
          Tkinter.wantobjects = 0

     Any breakage caused by this change should be reported as a bug.

   * The ‘UserDict’ module has a new ‘DictMixin’ class which defines all
     dictionary methods for classes that already have a minimum mapping
     interface.  This greatly simplifies writing classes that need to be
     substitutable for dictionaries, such as the classes in the *note
     shelve: c8. module.

     Adding the mix-in as a superclass provides the full dictionary
     interface whenever the class defines *note __getitem__(): 588,
     *note __setitem__(): 14d3, *note __delitem__(): 14d4, and ‘keys()’.
     For example:

          >>> import UserDict
          >>> class SeqDict(UserDict.DictMixin):
          ...     """Dictionary lookalike implemented with lists."""
          ...     def __init__(self):
          ...         self.keylist = []
          ...         self.valuelist = []
          ...     def __getitem__(self, key):
          ...         try:
          ...             i = self.keylist.index(key)
          ...         except ValueError:
          ...             raise KeyError
          ...         return self.valuelist[i]
          ...     def __setitem__(self, key, value):
          ...         try:
          ...             i = self.keylist.index(key)
          ...             self.valuelist[i] = value
          ...         except ValueError:
          ...             self.keylist.append(key)
          ...             self.valuelist.append(value)
          ...     def __delitem__(self, key):
          ...         try:
          ...             i = self.keylist.index(key)
          ...         except ValueError:
          ...             raise KeyError
          ...         self.keylist.pop(i)
          ...         self.valuelist.pop(i)
          ...     def keys(self):
          ...         return list(self.keylist)
          ...
          >>> s = SeqDict()
          >>> dir(s)      # See that other dictionary methods are implemented
          ['__cmp__', '__contains__', '__delitem__', '__doc__', '__getitem__',
           '__init__', '__iter__', '__len__', '__module__', '__repr__',
           '__setitem__', 'clear', 'get', 'has_key', 'items', 'iteritems',
           'iterkeys', 'itervalues', 'keylist', 'keys', 'pop', 'popitem',
           'setdefault', 'update', 'valuelist', 'values']

     (Contributed by Raymond Hettinger.)

   * The DOM implementation in *note xml.dom.minidom: 128. can now
     generate XML output in a particular encoding by providing an
     optional encoding argument to the *note toxml(): c8c. and *note
     toprettyxml(): c8d. methods of DOM nodes.

   * The ‘xmlrpclib’ module now supports an XML-RPC extension for
     handling nil data values such as Python’s ‘None’.  Nil values are
     always supported on unmarshalling an XML-RPC response.  To generate
     requests containing ‘None’, you must supply a true value for the
     'allow_none' parameter when creating a ‘Marshaller’ instance.

   * The new ‘DocXMLRPCServer’ module allows writing self-documenting
     XML-RPC servers.  Run it in demo mode (as a program) to see it in
     action.  Pointing the web browser to the RPC server produces
     pydoc-style documentation; pointing xmlrpclib to the server allows
     invoking the actual methods.  (Contributed by Brian Quinlan.)

   * Support for internationalized domain names (RFCs 3454, 3490, 3491,
     and 3492) has been added.  The «idna» encoding can be used to
     convert between a Unicode domain name and the ASCII-compatible
     encoding (ACE) of that name.

          >{}>{}> u"www.Alliancefrançaise.nu".encode("idna")
          'www.xn--alliancefranaise-npb.nu'

     The *note socket: d1. module has also been extended to
     transparently convert Unicode hostnames to the ACE version before
     passing them to the C library.  Modules that deal with hostnames
     such as ‘httplib’ and *note ftplib: 62.) also support Unicode host
     names; ‘httplib’ also sends HTTP ‘Host’ headers using the ACE
     version of the domain name.  *note urllib: 10e. supports Unicode
     URLs with non-ASCII host names as long as the ‘path’ part of the
     URL is ASCII only.

     To implement this change, the *note stringprep: da. module, the
     ‘mkstringprep’ tool and the ‘punycode’ encoding have been added.

* Menu:

* Date/Time Type::
* The optparse Module::

   ---------- Footnotes ----------

   (1) https://pybsddb.sourceforge.net


File: python.info,  Node: Date/Time Type,  Next: The optparse Module,  Up: New Improved and Deprecated Modules<4>

1.20.17.1 Date/Time Type
........................

Date and time types suitable for expressing timestamps were added as the
*note datetime: 34. module.  The types don’t support different calendars
or many fancy features, and just stick to the basics of representing
time.

The three primary types are: *note date: 1fa, representing a day, month,
and year; *note time: 1fb, consisting of hour, minute, and second; and
*note datetime: 4e3, which contains all the attributes of both *note
date: 1fa. and *note time: 1fb.  There’s also a *note timedelta: bc5.
class representing differences between two points in time, and time zone
logic is implemented by classes inheriting from the abstract *note
tzinfo: 7f7. class.

You can create instances of *note date: 1fa. and *note time: 1fb. by
either supplying keyword arguments to the appropriate constructor, e.g.
‘datetime.date(year=1972, month=10, day=15)’, or by using one of a
number of class methods.  For example, the *note today(): 16d1. class
method returns the current local date.

Once created, instances of the date/time classes are all immutable.
There are a number of methods for producing formatted strings from
objects:

     >>> import datetime
     >>> now = datetime.datetime.now()
     >>> now.isoformat()
     '2002-12-30T21:27:03.994956'
     >>> now.ctime()  # Only available on date, datetime
     'Mon Dec 30 21:27:03 2002'
     >>> now.strftime('%Y %d %b')
     '2002 30 Dec'

The *note replace(): 16d2. method allows modifying one or more fields of
a *note date: 1fa. or *note datetime: 4e3. instance, returning a new
instance:

     >>> d = datetime.datetime.now()
     >>> d
     datetime.datetime(2002, 12, 30, 22, 15, 38, 827738)
     >>> d.replace(year=2001, hour = 12)
     datetime.datetime(2001, 12, 30, 12, 15, 38, 827738)
     >>>

Instances can be compared, hashed, and converted to strings (the result
is the same as that of *note isoformat(): d27.).  *note date: 1fa. and
*note datetime: 4e3. instances can be subtracted from each other, and
added to *note timedelta: bc5. instances.  The largest missing feature
is that there’s no standard library support for parsing strings and
getting back a *note date: 1fa. or *note datetime: 4e3.

For more information, refer to the module’s reference documentation.
(Contributed by Tim Peters.)


File: python.info,  Node: The optparse Module,  Prev: Date/Time Type,  Up: New Improved and Deprecated Modules<4>

1.20.17.2 The optparse Module
.............................

The *note getopt: 65. module provides simple parsing of command-line
arguments.  The new *note optparse: a4. module (originally named Optik)
provides more elaborate command-line parsing that follows the Unix
conventions, automatically creates the output for ‘--help’, and can
perform different actions for different options.

You start by creating an instance of *note OptionParser: 16d4. and
telling it what your program’s options are.

     import sys
     from optparse import OptionParser

     op = OptionParser()
     op.add_option('-i', '--input',
                   action='store', type='string', dest='input',
                   help='set input filename')
     op.add_option('-l', '--length',
                   action='store', type='int', dest='length',
                   help='set maximum length of output')

Parsing a command line is then done by calling the *note parse_args():
16d5. method.

     options, args = op.parse_args(sys.argv[1:])
     print options
     print args

This returns an object containing all of the option values, and a list
of strings containing the remaining arguments.

Invoking the script with the various arguments now works as you’d expect
it to.  Note that the length argument is automatically converted to an
integer.

     $ ./python opt.py -i data arg1
     <Values at 0x400cad4c: {'input': 'data', 'length': None}>
     ['arg1']
     $ ./python opt.py --input=data --length=4
     <Values at 0x400cad2c: {'input': 'data', 'length': 4}>
     []
     $

The help message is automatically generated for you:

     $ ./python opt.py --help
     usage: opt.py [options]

     options:
       -h, --help            show this help message and exit
       -iINPUT, --input=INPUT
                             set input filename
       -lLENGTH, --length=LENGTH
                             set maximum length of output
     $

See the module’s documentation for more details.

Optik was written by Greg Ward, with suggestions from the readers of the
Getopt SIG.


File: python.info,  Node: Pymalloc A Specialized Object Allocator,  Next: Build and C API Changes<12>,  Prev: New Improved and Deprecated Modules<4>,  Up: What’s New in Python 2 3

1.20.18 Pymalloc: A Specialized Object Allocator
------------------------------------------------

Pymalloc, a specialized object allocator written by Vladimir Marangozov,
was a feature added to Python 2.1.  Pymalloc is intended to be faster
than the system ‘malloc()’ and to have less memory overhead for
allocation patterns typical of Python programs.  The allocator uses C’s
‘malloc()’ function to get large pools of memory and then fulfills
smaller memory requests from these pools.

In 2.1 and 2.2, pymalloc was an experimental feature and wasn’t enabled
by default; you had to explicitly enable it when compiling Python by
providing the ‘--with-pymalloc’ option to the ‘configure’ script.  In
2.3, pymalloc has had further enhancements and is now enabled by
default; you’ll have to supply ‘--without-pymalloc’ to disable it.

This change is transparent to code written in Python; however, pymalloc
may expose bugs in C extensions.  Authors of C extension modules should
test their code with pymalloc enabled, because some incorrect code may
cause core dumps at runtime.

There’s one particularly common error that causes problems.  There are a
number of memory allocation functions in Python’s C API that have
previously just been aliases for the C library’s ‘malloc()’ and
‘free()’, meaning that if you accidentally called mismatched functions
the error wouldn’t be noticeable.  When the object allocator is enabled,
these functions aren’t aliases of ‘malloc()’ and ‘free()’ any more, and
calling the wrong function to free memory may get you a core dump.  For
example, if memory was allocated using *note PyObject_Malloc(): e64, it
has to be freed using *note PyObject_Free(): e61, not ‘free()’.  A few
modules included with Python fell afoul of this and had to be fixed;
doubtless there are more third-party modules that will have the same
problem.

As part of this change, the confusing multiple interfaces for allocating
memory have been consolidated down into two API families.  Memory
allocated with one family must not be manipulated with functions from
the other family.  There is one family for allocating chunks of memory
and another family of functions specifically for allocating Python
objects.

   * To allocate and free an undistinguished chunk of memory use the
     «raw memory» family: *note PyMem_Malloc(): e62, *note
     PyMem_Realloc(): 1234, and *note PyMem_Free(): 1649.

   * The «object memory» family is the interface to the pymalloc
     facility described above and is biased towards a large number of
     «small» allocations: *note PyObject_Malloc(): e64, *note
     PyObject_Realloc(): 164a, and *note PyObject_Free(): e61.

   * To allocate and free Python objects, use the «object» family *note
     PyObject_New: b7e, *note PyObject_NewVar: b7f, and *note
     PyObject_Del(): 16d8.

Thanks to lots of work by Tim Peters, pymalloc in 2.3 also provides
debugging features to catch memory overwrites and doubled frees in both
extension modules and in the interpreter itself.  To enable this
support, compile a debugging version of the Python interpreter by
running ‘configure’ with ‘--with-pydebug’.

To aid extension writers, a header file ‘Misc/pymemcompat.h’ is
distributed with the source to Python 2.3 that allows Python extensions
to use the 2.3 interfaces to memory allocation while compiling against
any version of Python since 1.5.2.  You would copy the file from
Python’s source distribution and bundle it with the source of your
extension.

Vedi anche
..........

‘https://hg.python.org/cpython/file/default/Objects/obmalloc.c’

     For the full details of the pymalloc implementation, see the
     comments at the top of the file ‘Objects/obmalloc.c’ in the Python
     source code.  The above link points to the file within the
     python.org SVN browser.


File: python.info,  Node: Build and C API Changes<12>,  Next: Other Changes and Fixes<2>,  Prev: Pymalloc A Specialized Object Allocator,  Up: What’s New in Python 2 3

1.20.19 Build and C API Changes
-------------------------------

Changes to Python’s build process and to the C API include:

   * The cycle detection implementation used by the garbage collection
     has proven to be stable, so it’s now been made mandatory.  You can
     no longer compile Python without it, and the ‘--with-cycle-gc’
     switch to ‘configure’ has been removed.

   * Python can now optionally be built as a shared library
     (‘libpython2.3.so’) by supplying ‘--enable-shared’ when running
     Python’s ‘configure’ script.  (Contributed by Ondrej Palkovsky.)

   * The ‘DL_EXPORT’ and ‘DL_IMPORT’ macros are now deprecated.
     Initialization functions for Python extension modules should now be
     declared using the new macro *note PyMODINIT_FUNC: 16da, while the
     Python core will generally use the ‘PyAPI_FUNC’ and ‘PyAPI_DATA’
     macros.

   * The interpreter can be compiled without any docstrings for the
     built-in functions and modules by supplying ‘--without-doc-strings’
     to the ‘configure’ script.  This makes the Python executable about
     10% smaller, but will also mean that you can’t get help for
     Python’s built-ins.  (Contributed by Gustavo Niemeyer.)

   * The ‘PyArg_NoArgs()’ macro is now deprecated, and code that uses it
     should be changed.  For Python 2.2 and later, the method definition
     table can specify the *note METH_NOARGS: 16db. flag, signalling
     that there are no arguments, and the argument checking can then be
     removed.  If compatibility with pre-2.2 versions of Python is
     important, the code could use ‘PyArg_ParseTuple(args, "")’ instead,
     but this will be slower than using *note METH_NOARGS: 16db.

   * *note PyArg_ParseTuple(): 3c1. accepts new format characters for
     various sizes of unsigned integers: ‘B’ for unsigned char, ‘H’ for
     unsigned short int, ‘I’ for unsigned int, and ‘K’ for unsigned long
     long.

   * A new function, ‘PyObject_DelItemString(mapping, char *key)’ was
     added as shorthand for ‘PyObject_DelItem(mapping,
     PyString_New(key))’.

   * File objects now manage their internal string buffer differently,
     increasing it exponentially when needed.  This results in the
     benchmark tests in ‘Lib/test/test_bufio.py’ speeding up
     considerably (from 57 seconds to 1.7 seconds, according to one
     measurement).

   * It’s now possible to define class and static methods for a C
     extension type by setting either the *note METH_CLASS: 16dc. or
     *note METH_STATIC: 16dd. flags in a method’s *note PyMethodDef:
     16de. structure.

   * Python now includes a copy of the Expat XML parser’s source code,
     removing any dependence on a system version or local installation
     of Expat.

   * If you dynamically allocate type objects in your extension, you
     should be aware of a change in the rules relating to the *note
     __module__: 617. and *note __name__: 16b2. attributes.  In summary,
     you will want to ensure the type’s dictionary contains a
     ‘'__module__'’ key; making the module name the part of the type
     name leading up to the final period will no longer have the desired
     effect.  For more detail, read the API reference documentation or
     the source.

* Menu:

* Port-Specific Changes: Port-Specific Changes<3>.


File: python.info,  Node: Port-Specific Changes<3>,  Up: Build and C API Changes<12>

1.20.19.1 Port-Specific Changes
...............................

Support for a port to IBM’s OS/2 using the EMX runtime environment was
merged into the main Python source tree.  EMX is a POSIX emulation layer
over the OS/2 system APIs.  The Python port for EMX tries to support all
the POSIX-like capability exposed by the EMX runtime, and mostly
succeeds; ‘fork()’ and *note fcntl(): 5d. are restricted by the
limitations of the underlying emulation layer.  The standard OS/2 port,
which uses IBM’s Visual Age compiler, also gained support for
case-sensitive import semantics as part of the integration of the EMX
port into CVS. (Contributed by Andrew MacIntyre.)

On MacOS, most toolbox modules have been weaklinked to improve backward
compatibility.  This means that modules will no longer fail to load if a
single routine is missing on the current OS version.  Instead calling
the missing routine will raise an exception.  (Contributed by Jack
Jansen.)

The RPM spec files, found in the ‘Misc/RPM/’ directory in the Python
source distribution, were updated for 2.3.  (Contributed by Sean
Reifschneider.)

Other new platforms now supported by Python include AtheOS
(‘http://www.atheos.cx/’), GNU/Hurd, and OpenVMS.


File: python.info,  Node: Other Changes and Fixes<2>,  Next: Porting to Python 2 3,  Prev: Build and C API Changes<12>,  Up: What’s New in Python 2 3

1.20.20 Other Changes and Fixes
-------------------------------

As usual, there were a bunch of other improvements and bugfixes
scattered throughout the source tree.  A search through the CVS change
logs finds there were 523 patches applied and 514 bugs fixed between
Python 2.2 and 2.3.  Both figures are likely to be underestimates.

Some of the more notable changes are:

   * If the *note PYTHONINSPECT: 16e1. environment variable is set, the
     Python interpreter will enter the interactive prompt after running
     a Python program, as if Python had been invoked with the *note -i:
     16e2. option.  The environment variable can be set before running
     the Python interpreter, or it can be set by the Python program as
     part of its execution.

   * The ‘regrtest.py’ script now provides a way to allow «all resources
     except 'foo'.» A resource name passed to the ‘-u’ option can now be
     prefixed with a hyphen (‘'-'’) to mean «remove this resource.» For
     example, the option “‘-uall,-bsddb’” could be used to enable the
     use of all resources except ‘bsddb’.

   * The tools used to build the documentation now work under Cygwin as
     well as Unix.

   * The ‘SET_LINENO’ opcode has been removed.  Back in the mists of
     time, this opcode was needed to produce line numbers in tracebacks
     and support trace functions (for, e.g., *note pdb: aa.).  Since
     Python 1.5, the line numbers in tracebacks have been computed using
     a different mechanism that works with «python -O».  For Python 2.3
     Michael Hudson implemented a similar scheme to determine when to
     call the trace function, removing the need for ‘SET_LINENO’
     entirely.

     It would be difficult to detect any resulting difference from
     Python code, apart from a slight speed up when Python is run
     without *note -O: 18c.

     C extensions that access the *note f_lineno: 9b1. field of frame
     objects should instead call ‘PyCode_Addr2Line(f->f_code,
     f->f_lasti)’.  This will have the added effect of making the code
     work as desired under «python -O» in earlier versions of Python.

     A nifty new feature is that trace functions can now assign to the
     *note f_lineno: 9b1. attribute of frame objects, changing the line
     that will be executed next.  A ‘jump’ command has been added to the
     *note pdb: aa. debugger taking advantage of this new feature.
     (Implemented by Richie Hindle.)


File: python.info,  Node: Porting to Python 2 3,  Next: Acknowledgements<5>,  Prev: Other Changes and Fixes<2>,  Up: What’s New in Python 2 3

1.20.21 Porting to Python 2.3
-----------------------------

This section lists previously described changes that may require changes
to your code:

   * *note yield: bc4. is now always a keyword; if it’s used as a
     variable name in your code, a different name must be chosen.

   * For strings 'X' and 'Y', ‘X in Y’ now works if 'X' is more than one
     character long.

   * The *note int(): 19b. type constructor will now return a long
     integer instead of raising an *note OverflowError: a83. when a
     string or floating-point number is too large to fit into an
     integer.

   * If you have Unicode strings that contain 8-bit characters, you must
     declare the file’s encoding (UTF-8, Latin-1, or whatever) by adding
     a comment to the top of the file.  See section *note PEP 263;
     Source Code Encodings: 1691. for more information.

   * Calling Tcl methods through ‘_tkinter’ no longer returns only
     strings.  Instead, if Tcl returns other objects those objects are
     converted to their Python equivalent, if one exists, or wrapped
     with a ‘_tkinter.Tcl_Obj’ object if no Python equivalent exists.

   * Large octal and hex literals such as ‘0xffffffff’ now trigger a
     *note FutureWarning: 659.  Currently they’re stored as 32-bit
     numbers and result in a negative value, but in Python 2.4 they’ll
     become positive long integers.

     There are a few ways to fix this warning.  If you really need a
     positive number, just add an ‘L’ to the end of the literal.  If
     you’re trying to get a 32-bit integer with low bits set and have
     previously used an expression such as ‘~(1 << 31)’, it’s probably
     clearest to start with all bits set and clear the desired upper
     bits.  For example, to clear just the top bit (bit 31), you could
     write ‘0xffffffffL &~(1L<<31)’.

   * You can no longer disable assertions by assigning to ‘__debug__’.

   * The Distutils ‘setup()’ function has gained various new keyword
     arguments such as 'depends'.  Old versions of the Distutils will
     abort if passed unknown keywords.  A solution is to check for the
     presence of the new ‘get_distutil_options()’ function in your
     ‘setup.py’ and only uses the new keywords with a version of the
     Distutils that supports them:

          from distutils import core

          kw = {'sources': 'foo.c', ...}
          if hasattr(core, 'get_distutil_options'):
              kw['depends'] = ['foo.h']
          ext = Extension(**kw)

   * Using ‘None’ as a variable name will now result in a *note
     SyntaxWarning: 1ae. warning.

   * Names of extension types defined by the modules included with
     Python now contain the module and a ‘'.'’ in front of the type
     name.


File: python.info,  Node: Acknowledgements<5>,  Prev: Porting to Python 2 3,  Up: What’s New in Python 2 3

1.20.22 Acknowledgements
------------------------

The author would like to thank the following people for offering
suggestions, corrections and assistance with various drafts of this
article: Jeff Bauer, Simon Brunning, Brett Cannon, Michael Chermside,
Andrew Dalke, Scott David Daniels, Fred L. Drake, Jr., David Fraser,
Kelly Gerber, Raymond Hettinger, Michael Hudson, Chris Lambert, Detlef
Lannert, Martin von Löwis, Andrew MacIntyre, Lalo Martins, Chad Netzer,
Gustavo Niemeyer, Neal Norwitz, Hans Nowak, Chris Reedy, Francesco
Ricciardi, Vinay Sajip, Neil Schemenauer, Roman Suzi, Jason Tishler,
Just van Rossum.


File: python.info,  Node: What’s New in Python 2 2,  Next: What’s New in Python 2 1,  Prev: What’s New in Python 2 3,  Up: Novità in Python

1.21 What’s New in Python 2.2
=============================


Author: A.M. Kuchling

* Menu:

* Introduction::
* PEPs 252 and 253; Type and Class Changes: PEPs 252 and 253 Type and Class Changes.
* PEP 234; Iterators: PEP 234 Iterators.
* PEP 255; Simple Generators: PEP 255 Simple Generators<2>.
* PEP 237; Unifying Long Integers and Integers: PEP 237 Unifying Long Integers and Integers<2>.
* PEP 238; Changing the Division Operator: PEP 238 Changing the Division Operator.
* Unicode Changes::
* PEP 227; Nested Scopes: PEP 227 Nested Scopes.
* New and Improved Modules: New and Improved Modules<3>.
* Interpreter Changes and Fixes::
* Other Changes and Fixes: Other Changes and Fixes<3>.
* Acknowledgements: Acknowledgements<6>.


File: python.info,  Node: Introduction,  Next: PEPs 252 and 253 Type and Class Changes,  Up: What’s New in Python 2 2

1.21.1 Introduction
-------------------

This article explains the new features in Python 2.2.2, released on
October 14, 2002.  Python 2.2.2 is a bugfix release of Python 2.2,
originally released on December 21, 2001.

Python 2.2 can be thought of as the «cleanup release».  There are some
features such as generators and iterators that are completely new, but
most of the changes, significant and far-reaching though they may be,
are aimed at cleaning up irregularities and dark corners of the language
design.

This article doesn’t attempt to provide a complete specification of the
new features, but instead provides a convenient overview.  For full
details, you should refer to the documentation for Python 2.2, such as
the Python Library Reference(1) and the Python Reference Manual(2).  If
you want to understand the complete implementation and design rationale
for a change, refer to the PEP for a particular new feature.

   ---------- Footnotes ----------

   (1) https://docs.python.org/2.2/lib/lib.html

   (2) https://docs.python.org/2.2/ref/ref.html


File: python.info,  Node: PEPs 252 and 253 Type and Class Changes,  Next: PEP 234 Iterators,  Prev: Introduction,  Up: What’s New in Python 2 2

1.21.2 PEPs 252 and 253: Type and Class Changes
-----------------------------------------------

The largest and most far-reaching changes in Python 2.2 are to Python’s
model of objects and classes.  The changes should be backward
compatible, so it’s likely that your code will continue to run
unchanged, but the changes provide some amazing new capabilities.
Before beginning this, the longest and most complicated section of this
article, I’ll provide an overview of the changes and offer some
comments.

A long time ago I wrote a web page listing flaws in Python’s design.
One of the most significant flaws was that it’s impossible to subclass
Python types implemented in C. In particular, it’s not possible to
subclass built-in types, so you can’t just subclass, say, lists in order
to add a single useful method to them.  The ‘UserList’ module provides a
class that supports all of the methods of lists and that can be
subclassed further, but there’s lots of C code that expects a regular
Python list and won’t accept a *note UserList: 16eb. instance.

Python 2.2 fixes this, and in the process adds some exciting new
capabilities.  A brief summary:

   * You can subclass built-in types such as lists and even integers,
     and your subclasses should work in every place that requires the
     original type.

   * It’s now possible to define static and class methods, in addition
     to the instance methods available in previous versions of Python.

   * It’s also possible to automatically call methods on accessing or
     setting an instance attribute by using a new mechanism called
     'properties'.  Many uses of *note __getattr__(): 6fb. can be
     rewritten to use properties instead, making the resulting code
     simpler and faster.  As a small side benefit, attributes can now
     have docstrings, too.

   * The list of legal attributes for an instance can be limited to a
     particular set using 'slots', making it possible to safeguard
     against typos and perhaps make more optimizations possible in
     future versions of Python.

Some users have voiced concern about all these changes.  Sure, they say,
the new features are neat and lend themselves to all sorts of tricks
that weren’t possible in previous versions of Python, but they also make
the language more complicated.  Some people have said that they’ve
always recommended Python for its simplicity, and feel that its
simplicity is being lost.

Personally, I think there’s no need to worry.  Many of the new features
are quite esoteric, and you can write a lot of Python code without ever
needed to be aware of them.  Writing a simple class is no more difficult
than it ever was, so you don’t need to bother learning or teaching them
unless they’re actually needed.  Some very complicated tasks that were
previously only possible from C will now be possible in pure Python, and
to my mind that’s all for the better.

I’m not going to attempt to cover every single corner case and small
change that were required to make the new features work.  Instead this
section will paint only the broad strokes.  See section *note Related
Links: 16ec, «Related Links», for further sources of information about
Python 2.2’s new object model.

* Menu:

* Old and New Classes::
* Descriptors::
* Multiple Inheritance; The Diamond Rule: Multiple Inheritance The Diamond Rule.
* Attribute Access::
* Related Links::


File: python.info,  Node: Old and New Classes,  Next: Descriptors,  Up: PEPs 252 and 253 Type and Class Changes

1.21.2.1 Old and New Classes
............................

First, you should know that Python 2.2 really has two kinds of classes:
classic or old-style classes, and new-style classes.  The old-style
class model is exactly the same as the class model in earlier versions
of Python.  All the new features described in this section apply only to
new-style classes.  This divergence isn’t intended to last forever;
eventually old-style classes will be dropped, possibly in Python 3.0.

So how do you define a new-style class?  You do it by subclassing an
existing new-style class.  Most of Python’s built-in types, such as
integers, lists, dictionaries, and even files, are new-style classes
now.  A new-style class named *note object: c80, the base class for all
built-in types, has also been added so if no built-in type is suitable,
you can just subclass *note object: c80.:

     class C(object):
         def __init__ (self):
             ...
         ...

This means that *note class: 14df. statements that don’t have any base
classes are always classic classes in Python 2.2.  (Actually you can
also change this by setting a module-level variable named
‘__metaclass__’ — see PEP 253(1) for the details — but it’s easier to
just subclass *note object: c80.)

The type objects for the built-in types are available as built-ins,
named using a clever trick.  Python has always had built-in functions
named *note int(): 19b, *note float(): 196, and *note str(): 169.  In
2.2, they aren’t functions any more, but type objects that behave as
factories when called.

     >>> int
     <type 'int'>
     >>> int('123')
     123

To make the set of types complete, new type objects such as *note
dict(): 183. and ‘file()’ have been added.  Here’s a more interesting
example, adding a ‘lock()’ method to file objects:

     class LockableFile(file):
         def lock (self, operation, length=0, start=0, whence=0):
             import fcntl
             return fcntl.lockf(self.fileno(), operation,
                                length, start, whence)

The now-obsolete ‘posixfile’ module contained a class that emulated all
of a file object’s methods and also added a ‘lock()’ method, but this
class couldn’t be passed to internal functions that expected a built-in
file, something which is possible with our new ‘LockableFile’.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0253/


File: python.info,  Node: Descriptors,  Next: Multiple Inheritance The Diamond Rule,  Prev: Old and New Classes,  Up: PEPs 252 and 253 Type and Class Changes

1.21.2.2 Descriptors
....................

In previous versions of Python, there was no consistent way to discover
what attributes and methods were supported by an object.  There were
some informal conventions, such as defining ‘__members__’ and
‘__methods__’ attributes that were lists of names, but often the author
of an extension type or a class wouldn’t bother to define them.  You
could fall back on inspecting the *note __dict__: 77e. of an object, but
when class inheritance or an arbitrary ‘__getattr__()’ hook were in use
this could still be inaccurate.

The one big idea underlying the new class model is that an API for
describing the attributes of an object using 'descriptors' has been
formalized.  Descriptors specify the value of an attribute, stating
whether it’s a method or a field.  With the descriptor API, static
methods and class methods become possible, as well as more exotic
constructs.

Attribute descriptors are objects that live inside class objects, and
have a few attributes of their own:

   * *note __name__: 1268. is the attribute’s name.

   * *note __doc__: b23. is the attribute’s docstring.

   * ‘__get__(object)’ is a method that retrieves the attribute value
     from 'object'.

   * ‘__set__(object, value)’ sets the attribute on 'object' to 'value'.

   * ‘__delete__(object, value)’ deletes the 'value' attribute of
     'object'.

For example, when you write ‘obj.x’, the steps that Python actually
performs are:

     descriptor = obj.__class__.x
     descriptor.__get__(obj)

For methods, *note descriptor.__get__: 16ef. returns a temporary object
that’s callable, and wraps up the instance and the method to be called
on it.  This is also why static methods and class methods are now
possible; they have descriptors that wrap up just the method, or the
method and the class.  As a brief explanation of these new kinds of
methods, static methods aren’t passed the instance, and therefore
resemble regular functions.  Class methods are passed the class of the
object, but not the object itself.  Static and class methods are defined
like this:

     class C(object):
         def f(arg1, arg2):
             ...
         f = staticmethod(f)

         def g(cls, arg1, arg2):
             ...
         g = classmethod(g)

The *note staticmethod(): 453. function takes the function ‘f()’, and
returns it wrapped up in a descriptor so it can be stored in the class
object.  You might expect there to be special syntax for creating such
methods (‘def static f’, ‘defstatic f()’, or something like that) but no
such syntax has been defined yet; that’s been left for future versions
of Python.

More new features, such as slots and properties, are also implemented as
new kinds of descriptors, and it’s not difficult to write a descriptor
class that does something novel.  For example, it would be possible to
write a descriptor class that made it possible to write Eiffel-style
preconditions and postconditions for a method.  A class that used this
feature might be defined like this:

     from eiffel import eiffelmethod

     class C(object):
         def f(self, arg1, arg2):
             # The actual function
             ...
         def pre_f(self):
             # Check preconditions
             ...
         def post_f(self):
             # Check postconditions
             ...

         f = eiffelmethod(f, pre_f, post_f)

Note that a person using the new ‘eiffelmethod()’ doesn’t have to
understand anything about descriptors.  This is why I think the new
features don’t increase the basic complexity of the language.  There
will be a few wizards who need to know about it in order to write
‘eiffelmethod()’ or the ZODB or whatever, but most users will just write
code on top of the resulting libraries and ignore the implementation
details.


File: python.info,  Node: Multiple Inheritance The Diamond Rule,  Next: Attribute Access,  Prev: Descriptors,  Up: PEPs 252 and 253 Type and Class Changes

1.21.2.3 Multiple Inheritance: The Diamond Rule
...............................................

Multiple inheritance has also been made more useful through changing the
rules under which names are resolved.  Consider this set of classes
(diagram taken from PEP 253(1) by Guido van Rossum):

           class A:
             ^ ^  def save(self): ...
            /   \
           /     \
          /       \
         /         \
     class B     class C:
         ^         ^  def save(self): ...
          \       /
           \     /
            \   /
             \ /
           class D

The lookup rule for classic classes is simple but not very smart; the
base classes are searched depth-first, going from left to right.  A
reference to ‘D.save()’ will search the classes ‘D’, ‘B’, and then ‘A’,
where ‘save()’ would be found and returned.  ‘C.save()’ would never be
found at all.  This is bad, because if ‘C’’s ‘save()’ method is saving
some internal state specific to ‘C’, not calling it will result in that
state never getting saved.

New-style classes follow a different algorithm that’s a bit more
complicated to explain, but does the right thing in this situation.
(Note that Python 2.3 changes this algorithm to one that produces the
same results in most cases, but produces more useful results for really
complicated inheritance graphs.)

  1. List all the base classes, following the classic lookup rule and
     include a class multiple times if it’s visited repeatedly.  In the
     above example, the list of visited classes is [‘D’, ‘B’, ‘A’, ‘C’,
     ‘A’].

  2. Scan the list for duplicated classes.  If any are found, remove all
     but one occurrence, leaving the 'last' one in the list.  In the
     above example, the list becomes [‘D’, ‘B’, ‘C’, ‘A’] after dropping
     duplicates.

Following this rule, referring to ‘D.save()’ will return ‘C.save()’,
which is the behaviour we’re after.  This lookup rule is the same as the
one followed by Common Lisp.  A new built-in function, *note super():
1a6, provides a way to get at a class’s superclasses without having to
reimplement Python’s algorithm.  The most commonly used form will be
‘super(class, obj)’, which returns a bound superclass object (not the
actual class object).  This form will be used in methods to call a
method in the superclass; for example, ‘D’’s ‘save()’ method would look
like this:

     class D (B,C):
         def save (self):
             # Call superclass .save()
             super(D, self).save()
             # Save D's private information here
             ...

*note super(): 1a6. can also return unbound superclass objects when
called as ‘super(class)’ or ‘super(class1, class2)’, but this probably
won’t often be useful.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0253/


File: python.info,  Node: Attribute Access,  Next: Related Links,  Prev: Multiple Inheritance The Diamond Rule,  Up: PEPs 252 and 253 Type and Class Changes

1.21.2.4 Attribute Access
.........................

A fair number of sophisticated Python classes define hooks for attribute
access using *note __getattr__(): 6fb.; most commonly this is done for
convenience, to make code more readable by automatically mapping an
attribute access such as ‘obj.parent’ into a method call such as
‘obj.get_parent’.  Python 2.2 adds some new ways of controlling
attribute access.

First, ‘__getattr__(attr_name)’ is still supported by new-style classes,
and nothing about it has changed.  As before, it will be called when an
attempt is made to access ‘obj.foo’ and no attribute named ‘foo’ is
found in the instance’s dictionary.

New-style classes also support a new method,
‘__getattribute__(attr_name)’.  The difference between the two methods
is that *note __getattribute__(): dcd. is 'always' called whenever any
attribute is accessed, while the old *note __getattr__(): 6fb. is only
called if ‘foo’ isn’t found in the instance’s dictionary.

However, Python 2.2’s support for 'properties' will often be a simpler
way to trap attribute references.  Writing a ‘__getattr__()’ method is
complicated because to avoid recursion you can’t use regular attribute
accesses inside them, and instead have to mess around with the contents
of *note __dict__: 77e.  *note __getattr__(): 6fb. methods also end up
being called by Python when it checks for other methods such as *note
__repr__(): 830. or ‘__coerce__()’, and so have to be written with this
in mind.  Finally, calling a function on every attribute access results
in a sizable performance loss.

*note property: 4b4. is a new built-in type that packages up three
functions that get, set, or delete an attribute, and a docstring.  For
example, if you want to define a ‘size’ attribute that’s computed, but
also settable, you could write:

     class C(object):
         def get_size (self):
             result = ... computation ...
             return result
         def set_size (self, size):
             ... compute something based on the size
             and set internal state appropriately ...

         # Define a property.  The 'delete this attribute'
         # method is defined as None, so the attribute
         # can't be deleted.
         size = property(get_size, set_size,
                         None,
                         "Storage size of this instance")

That is certainly clearer and easier to write than a pair of
‘__getattr__()’/‘__setattr__()’ methods that check for the ‘size’
attribute and handle it specially while retrieving all other attributes
from the instance’s *note __dict__: 77e.  Accesses to ‘size’ are also
the only ones which have to perform the work of calling a function, so
references to other attributes run at their usual speed.

Finally, it’s possible to constrain the list of attributes that can be
referenced on an object using the new *note __slots__: 16f2. class
attribute.  Python objects are usually very dynamic; at any time it’s
possible to define a new attribute on an instance by just doing
‘obj.new_attr=1’.  A new-style class can define a class attribute named
*note __slots__: 16f2. to limit the legal attributes to a particular set
of names.  An example will make this clear:

     >>> class C(object):
     ...     __slots__ = ('template', 'name')
     ...
     >>> obj = C()
     >>> print obj.template
     None
     >>> obj.template = 'Test'
     >>> print obj.template
     Test
     >>> obj.newattr = None
     Traceback (most recent call last):
       File "<stdin>", line 1, in ?
     AttributeError: 'C' object has no attribute 'newattr'

Note how you get an *note AttributeError: 5f0. on the attempt to assign
to an attribute not listed in *note __slots__: 16f2.


File: python.info,  Node: Related Links,  Prev: Attribute Access,  Up: PEPs 252 and 253 Type and Class Changes

1.21.2.5 Related Links
......................

This section has just been a quick overview of the new features, giving
enough of an explanation to start you programming, but many details have
been simplified or ignored.  Where should you go to get a more complete
picture?

The *note Descriptor Guide: 16f4. is a lengthy tutorial introduction to
the descriptor features, written by Guido van Rossum.  If my description
has whetted your appetite, go read this tutorial next, because it goes
into much more detail about the new features while still remaining quite
easy to read.

Next, there are two relevant PEPs, PEP 252(1) and PEP 253(2).  PEP
252(3) is titled «Making Types Look More Like Classes», and covers the
descriptor API. PEP 253(4) is titled «Subtyping Built-in Types», and
describes the changes to type objects that make it possible to subtype
built-in objects.  PEP 253(5) is the more complicated PEP of the two,
and at a few points the necessary explanations of types and meta-types
may cause your head to explode.  Both PEPs were written and implemented
by Guido van Rossum, with substantial assistance from the rest of the
Zope Corp.  team.

Finally, there’s the ultimate authority: the source code.  Most of the
machinery for the type handling is in ‘Objects/typeobject.c’, but you
should only resort to it after all other avenues have been exhausted,
including posting a question to python-list or python-dev.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0252/

   (2) https://peps.python.org/pep-0253/

   (3) https://peps.python.org/pep-0252/

   (4) https://peps.python.org/pep-0253/

   (5) https://peps.python.org/pep-0253/


File: python.info,  Node: PEP 234 Iterators,  Next: PEP 255 Simple Generators<2>,  Prev: PEPs 252 and 253 Type and Class Changes,  Up: What’s New in Python 2 2

1.21.3 PEP 234: Iterators
-------------------------

Another significant addition to 2.2 is an iteration interface at both
the C and Python levels.  Objects can define how they can be looped over
by callers.

In Python versions up to 2.1, the usual way to make ‘for item in obj’
work is to define a *note __getitem__(): 588. method that looks
something like this:

     def __getitem__(self, index):
         return <next item>

*note __getitem__(): 588. is more properly used to define an indexing
operation on an object so that you can write ‘obj[5]’ to retrieve the
sixth element.  It’s a bit misleading when you’re using this only to
support *note for: 34a. loops.  Consider some file-like object that
wants to be looped over; the 'index' parameter is essentially
meaningless, as the class probably assumes that a series of *note
__getitem__(): 588. calls will be made with 'index' incrementing by one
each time.  In other words, the presence of the *note __getitem__():
588. method doesn’t mean that using ‘file[5]’ to randomly access the
sixth element will work, though it really should.

In Python 2.2, iteration can be implemented separately, and *note
__getitem__(): 588. methods can be limited to classes that really do
support random access.  The basic idea of iterators is simple.  A new
built-in function, ‘iter(obj)’ or ‘iter(C, sentinel)’, is used to get an
iterator.  ‘iter(obj)’ returns an iterator for the object 'obj', while
‘iter(C, sentinel)’ returns an iterator that will invoke the callable
object 'C' until it returns 'sentinel' to signal that the iterator is
done.

Python classes can define an ‘__iter__()’ method, which should create
and return a new iterator for the object; if the object is its own
iterator, this method can just return ‘self’.  In particular, iterators
will usually be their own iterators.  Extension types implemented in C
can implement a *note tp_iter: 16f6. function in order to return an
iterator, and extension types that want to behave as iterators can
define a *note tp_iternext: 16f7. function.

So, after all this, what do iterators actually do?  They have one
required method, *note next(): 9da, which takes no arguments and returns
the next value.  When there are no more values to be returned, calling
*note next(): 9da. should raise the *note StopIteration: df7. exception.

     >>> L = [1,2,3]
     >>> i = iter(L)
     >>> print i
     <iterator object at 0x8116870>
     >>> i.next()
     1
     >>> i.next()
     2
     >>> i.next()
     3
     >>> i.next()
     Traceback (most recent call last):
       File "<stdin>", line 1, in ?
     StopIteration
     >>>

In 2.2, Python’s *note for: 34a. statement no longer expects a sequence;
it expects something for which *note iter(): 9d9. will return an
iterator.  For backward compatibility and convenience, an iterator is
automatically constructed for sequences that don’t implement
‘__iter__()’ or a *note tp_iter: 16f6. slot, so ‘for i in [1,2,3]’ will
still work.  Wherever the Python interpreter loops over a sequence, it’s
been changed to use the iterator protocol.  This means you can do things
like this:

     >>> L = [1,2,3]
     >>> i = iter(L)
     >>> a,b,c = i
     >>> a,b,c
     (1, 2, 3)

Iterator support has been added to some of Python’s basic types.
Calling *note iter(): 9d9. on a dictionary will return an iterator which
loops over its keys:

     >>> m = {'Jan': 1, 'Feb': 2, 'Mar': 3, 'Apr': 4, 'May': 5, 'Jun': 6,
     ...      'Jul': 7, 'Aug': 8, 'Sep': 9, 'Oct': 10, 'Nov': 11, 'Dec': 12}
     >>> for key in m: print key, m[key]
     ...
     Mar 3
     Feb 2
     Aug 8
     Sep 9
     May 5
     Jun 6
     Jul 7
     Jan 1
     Apr 4
     Nov 11
     Dec 12
     Oct 10

That’s just the default behaviour.  If you want to iterate over keys,
values, or key/value pairs, you can explicitly call the ‘iterkeys()’,
‘itervalues()’, or ‘iteritems()’ methods to get an appropriate iterator.
In a minor related change, the *note in: 34b. operator now works on
dictionaries, so ‘key in dict’ is now equivalent to ‘dict.has_key(key)’.

Files also provide an iterator, which calls the *note readline(): bf.
method until there are no more lines in the file.  This means you can
now read each line of a file using code like this:

     for line in file:
         # do something for each line
         ...

Note that you can only go forward in an iterator; there’s no way to get
the previous element, reset the iterator, or make a copy of it.  An
iterator object could provide such additional capabilities, but the
iterator protocol only requires a *note next(): 9da. method.

Vedi anche
..........

PEP 234(1) - Iterators

     Written by Ka-Ping Yee and GvR; implemented by the Python Labs
     crew, mostly by GvR and Tim Peters.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0234/


File: python.info,  Node: PEP 255 Simple Generators<2>,  Next: PEP 237 Unifying Long Integers and Integers<2>,  Prev: PEP 234 Iterators,  Up: What’s New in Python 2 2

1.21.4 PEP 255: Simple Generators
---------------------------------

Generators are another new feature, one that interacts with the
introduction of iterators.

You’re doubtless familiar with how function calls work in Python or C.
When you call a function, it gets a private namespace where its local
variables are created.  When the function reaches a *note return: 1af.
statement, the local variables are destroyed and the resulting value is
returned to the caller.  A later call to the same function will get a
fresh new set of local variables.  But, what if the local variables
weren’t thrown away on exiting a function?  What if you could later
resume the function where it left off?  This is what generators provide;
they can be thought of as resumable functions.

Here’s the simplest example of a generator function:

     def generate_ints(N):
         for i in range(N):
             yield i

A new keyword, *note yield: bc4, was introduced for generators.  Any
function containing a ‘yield’ statement is a generator function; this is
detected by Python’s bytecode compiler which compiles the function
specially as a result.  Because a new keyword was introduced, generators
must be explicitly enabled in a module by including a ‘from __future__
import generators’ statement near the top of the module’s source code.
In Python 2.3 this statement will become unnecessary.

When you call a generator function, it doesn’t return a single value;
instead it returns a generator object that supports the iterator
protocol.  On executing the *note yield: bc4. statement, the generator
outputs the value of ‘i’, similar to a *note return: 1af. statement.
The big difference between ‘yield’ and a ‘return’ statement is that on
reaching a ‘yield’ the generator’s state of execution is suspended and
local variables are preserved.  On the next call to the generator’s
‘next()’ method, the function will resume executing immediately after
the ‘yield’ statement.  (For complicated reasons, the ‘yield’ statement
isn’t allowed inside the ‘try’ block of a *note try: 8f9.…*note finally:
1b0. statement; read PEP 255(1) for a full explanation of the
interaction between ‘yield’ and exceptions.)

Here’s a sample usage of the ‘generate_ints()’ generator:

     >>> gen = generate_ints(3)
     >>> gen
     <generator object at 0x8117f90>
     >>> gen.next()
     0
     >>> gen.next()
     1
     >>> gen.next()
     2
     >>> gen.next()
     Traceback (most recent call last):
       File "<stdin>", line 1, in ?
       File "<stdin>", line 2, in generate_ints
     StopIteration

You could equally write ‘for i in generate_ints(5)’, or ‘a,b,c =
generate_ints(3)’.

Inside a generator function, the *note return: 1af. statement can only
be used without a value, and signals the end of the procession of
values; afterwards the generator cannot return any further values.
‘return’ with a value, such as ‘return 5’, is a syntax error inside a
generator function.  The end of the generator’s results can also be
indicated by raising *note StopIteration: df7. manually, or by just
letting the flow of execution fall off the bottom of the function.

You could achieve the effect of generators manually by writing your own
class and storing all the local variables of the generator as instance
variables.  For example, returning a list of integers could be done by
setting ‘self.count’ to 0, and having the *note next(): 9da. method
increment ‘self.count’ and return it.  However, for a moderately
complicated generator, writing a corresponding class would be much
messier.  ‘Lib/test/test_generators.py’ contains a number of more
interesting examples.  The simplest one implements an in-order traversal
of a tree using generators recursively.

     # A recursive generator that generates Tree leaves in in-order.
     def inorder(t):
         if t:
             for x in inorder(t.left):
                 yield x
             yield t.label
             for x in inorder(t.right):
                 yield x

Two other examples in ‘Lib/test/test_generators.py’ produce solutions
for the N-Queens problem (placing $N$ queens on an $NxN$ chess board so
that no queen threatens another) and the Knight’s Tour (a route that
takes a knight to every square of an $NxN$ chessboard without visiting
any square twice).

The idea of generators comes from other programming languages,
especially Icon (‘https://www2.cs.arizona.edu/icon/’), where the idea of
generators is central.  In Icon, every expression and function call
behaves like a generator.  One example from «An Overview of the Icon
Programming Language» at
‘https://www2.cs.arizona.edu/icon/docs/ipd266.htm’ gives an idea of what
this looks like:

     sentence := "Store it in the neighboring harbor"
     if (i := find("or", sentence)) > 5 then write(i)

In Icon the ‘find()’ function returns the indexes at which the substring
«or» is found: 3, 23, 33.  In the *note if: 181. statement, ‘i’ is first
assigned a value of 3, but 3 is less than 5, so the comparison fails,
and Icon retries it with the second value of 23.  23 is greater than 5,
so the comparison now succeeds, and the code prints the value 23 to the
screen.

Python doesn’t go nearly as far as Icon in adopting generators as a
central concept.  Generators are considered a new part of the core
Python language, but learning or using them isn’t compulsory; if they
don’t solve any problems that you have, feel free to ignore them.  One
novel feature of Python’s interface as compared to Icon’s is that a
generator’s state is represented as a concrete object (the iterator)
that can be passed around to other functions or stored in a data
structure.

Vedi anche
..........

PEP 255(2) - Simple Generators

     Written by Neil Schemenauer, Tim Peters, Magnus Lie Hetland.
     Implemented mostly by Neil Schemenauer and Tim Peters, with other
     fixes from the Python Labs crew.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0255/

   (2) https://peps.python.org/pep-0255/


File: python.info,  Node: PEP 237 Unifying Long Integers and Integers<2>,  Next: PEP 238 Changing the Division Operator,  Prev: PEP 255 Simple Generators<2>,  Up: What’s New in Python 2 2

1.21.5 PEP 237: Unifying Long Integers and Integers
---------------------------------------------------

In recent versions, the distinction between regular integers, which are
32-bit values on most machines, and long integers, which can be of
arbitrary size, was becoming an annoyance.  For example, on platforms
that support files larger than ‘2**32’ bytes, the ‘tell()’ method of
file objects has to return a long integer.  However, there were various
bits of Python that expected plain integers and would raise an error if
a long integer was provided instead.  For example, in Python 1.5, only
regular integers could be used as a slice index, and ‘'abc'[1L:]’ would
raise a *note TypeError: 198. exception with the message “slice index
must be int”.

Python 2.2 will shift values from short to long integers as required.
The “L” suffix is no longer needed to indicate a long integer literal,
as now the compiler will choose the appropriate type.  (Using the “L”
suffix will be discouraged in future 2.x versions of Python, triggering
a warning in Python 2.4, and probably dropped in Python 3.0.)  Many
operations that used to raise an *note OverflowError: a83. will now
return a long integer as their result.  For example:

     >>> 1234567890123
     1234567890123L
     >>> 2 ** 64
     18446744073709551616L

In most cases, integers and long integers will now be treated
identically.  You can still distinguish them with the *note type(): f46.
built-in function, but that’s rarely needed.

Vedi anche
..........

PEP 237(1) - Unifying Long Integers and Integers

     Written by Moshe Zadka and Guido van Rossum.  Implemented mostly by
     Guido van Rossum.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0237/


File: python.info,  Node: PEP 238 Changing the Division Operator,  Next: Unicode Changes,  Prev: PEP 237 Unifying Long Integers and Integers<2>,  Up: What’s New in Python 2 2

1.21.6 PEP 238: Changing the Division Operator
----------------------------------------------

The most controversial change in Python 2.2 heralds the start of an
effort to fix an old design flaw that’s been in Python from the
beginning.  Currently Python’s division operator, ‘/’, behaves like C’s
division operator when presented with two integer arguments: it returns
an integer result that’s truncated down when there would be a fractional
part.  For example, ‘3/2’ is 1, not 1.5, and ‘(-1)/2’ is -1, not -0.5.
This means that the results of division can vary unexpectedly depending
on the type of the two operands and because Python is dynamically typed,
it can be difficult to determine the possible types of the operands.

(The controversy is over whether this is 'really' a design flaw, and
whether it’s worth breaking existing code to fix this.  It’s caused
endless discussions on python-dev, and in July 2001 erupted into a storm
of acidly sarcastic postings on ‘comp.lang.python’.  I won’t argue for
either side here and will stick to describing what’s implemented in 2.2.
Read PEP 238(1) for a summary of arguments and counter-arguments.)

Because this change might break code, it’s being introduced very
gradually.  Python 2.2 begins the transition, but the switch won’t be
complete until Python 3.0.

First, I’ll borrow some terminology from PEP 238(2).  «True division» is
the division that most non-programmers are familiar with: 3/2 is 1.5,
1/4 is 0.25, and so forth.  «Floor division» is what Python’s ‘/’
operator currently does when given integer operands; the result is the
floor of the value returned by true division.  «Classic division» is the
current mixed behaviour of ‘/’; it returns the result of floor division
when the operands are integers, and returns the result of true division
when one of the operands is a floating-point number.

Here are the changes 2.2 introduces:

   * A new operator, ‘//’, is the floor division operator.  (Yes, we
     know it looks like C++”s comment symbol.)  ‘//’ 'always' performs
     floor division no matter what the types of its operands are, so ‘1
     // 2’ is 0 and ‘1.0 // 2.0’ is also 0.0.

     ‘//’ is always available in Python 2.2; you don’t need to enable it
     using a ‘__future__’ statement.

   * By including a ‘from __future__ import division’ in a module, the
     ‘/’ operator will be changed to return the result of true division,
     so ‘1/2’ is 0.5.  Without the ‘__future__’ statement, ‘/’ still
     means classic division.  The default meaning of ‘/’ will not change
     until Python 3.0.

   * Classes can define methods called *note __truediv__(): 1092. and
     *note __floordiv__(): 16fb. to overload the two division operators.
     At the C level, there are also slots in the *note PyNumberMethods:
     1625. structure so extension types can define the two operators.

   * Python 2.2 supports some command-line arguments for testing whether
     code will work with the changed division semantics.  Running python
     with ‘-Q warn’ will cause a warning to be issued whenever division
     is applied to two integers.  You can use this to find code that’s
     affected by the change and fix it.  By default, Python 2.2 will
     simply perform classic division without a warning; the warning will
     be turned on by default in Python 2.3.

Vedi anche
..........

PEP 238(3) - Changing the Division Operator

     Written by Moshe Zadka and Guido van Rossum.  Implemented by Guido
     van Rossum..

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0238/

   (2) https://peps.python.org/pep-0238/

   (3) https://peps.python.org/pep-0238/


File: python.info,  Node: Unicode Changes,  Next: PEP 227 Nested Scopes,  Prev: PEP 238 Changing the Division Operator,  Up: What’s New in Python 2 2

1.21.7 Unicode Changes
----------------------

Python’s Unicode support has been enhanced a bit in 2.2.  Unicode
strings are usually stored as UCS-2, as 16-bit unsigned integers.
Python 2.2 can also be compiled to use UCS-4, 32-bit unsigned integers,
as its internal encoding by supplying ‘--enable-unicode=ucs4’ to the
configure script.  (It’s also possible to specify ‘--disable-unicode’ to
completely disable Unicode support.)

When built to use UCS-4 (a «wide Python»), the interpreter can natively
handle Unicode characters from U+000000 to U+110000, so the range of
legal values for the ‘unichr()’ function is expanded accordingly.  Using
an interpreter compiled to use UCS-2 (a «narrow Python»), values greater
than 65535 will still cause ‘unichr()’ to raise a *note ValueError: 2ec.
exception.  This is all described in PEP 261(1), «Support for “wide”
Unicode characters»; consult it for further details.

Another change is simpler to explain.  Since their introduction, Unicode
strings have supported an ‘encode()’ method to convert the string to a
selected encoding such as UTF-8 or Latin-1.  A symmetric
‘decode([*encoding*])’ method has been added to 8-bit strings (though
not to Unicode strings) in 2.2.  ‘decode()’ assumes that the string is
in the specified encoding and decodes it, returning whatever is returned
by the codec.

Using this new feature, codecs have been added for tasks not directly
related to Unicode.  For example, codecs have been added for
uu-encoding, MIME’s base64 encoding, and compression with the *note
zlib: 139. module:

     >>> s = """Here is a lengthy piece of redundant, overly verbose,
     ... and repetitive text.
     ... """
     >>> data = s.encode('zlib')
     >>> data
     'x\x9c\r\xc9\xc1\r\x80 \x10\x04\xc0?Ul...'
     >>> data.decode('zlib')
     'Here is a lengthy piece of redundant, overly verbose,\nand repetitive text.\n'
     >>> print s.encode('uu')
     begin 666 <data>
     M2&5R92!I<R!A(&QE;F=T:'D@<&EE8V4@;V8@<F5D=6YD86YT+"!O=F5R;'D@
     >=F5R8F]S92P*86YD(')E<&5T:71I=F4@=&5X="X*

     end
     >>> "sheesh".encode('rot-13')
     'furrfu'

To convert a class instance to Unicode, a ‘__unicode__()’ method can be
defined by a class, analogous to ‘__str__()’.

‘encode()’, ‘decode()’, and ‘__unicode__()’ were implemented by
Marc-André Lemburg.  The changes to support using UCS-4 internally were
implemented by Fredrik Lundh and Martin von Löwis.

Vedi anche
..........

PEP 261(2) - Support for “wide” Unicode characters

     Written by Paul Prescod.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0261/

   (2) https://peps.python.org/pep-0261/


File: python.info,  Node: PEP 227 Nested Scopes,  Next: New and Improved Modules<3>,  Prev: Unicode Changes,  Up: What’s New in Python 2 2

1.21.8 PEP 227: Nested Scopes
-----------------------------

In Python 2.1, statically nested scopes were added as an optional
feature, to be enabled by a ‘from __future__ import nested_scopes’
directive.  In 2.2 nested scopes no longer need to be specially enabled,
and are now always present.  The rest of this section is a copy of the
description of nested scopes from my «What’s New in Python 2.1»
document; if you read it when 2.1 came out, you can skip the rest of
this section.

The largest change introduced in Python 2.1, and made complete in 2.2,
is to Python’s scoping rules.  In Python 2.0, at any given time there
are at most three namespaces used to look up variable names: local,
module-level, and the built-in namespace.  This often surprised people
because it didn’t match their intuitive expectations.  For example, a
nested recursive function definition doesn’t work:

     def f():
         ...
         def g(value):
             ...
             return g(value-1) + 1
         ...

The function ‘g()’ will always raise a *note NameError: 452. exception,
because the binding of the name ‘g’ isn’t in either its local namespace
or in the module-level namespace.  This isn’t much of a problem in
practice (how often do you recursively define interior functions like
this?), but this also made using the *note lambda: 14a5. expression
clumsier, and this was a problem in practice.  In code which uses
‘lambda’ you can often find local variables being copied by passing them
as the default values of arguments.

     def find(self, name):
         "Return list of any entries equal to 'name'"
         L = filter(lambda x, name=name: x == name,
                    self.list_attribute)
         return L

The readability of Python code written in a strongly functional style
suffers greatly as a result.

The most significant change to Python 2.2 is that static scoping has
been added to the language to fix this problem.  As a first effect, the
‘name=name’ default argument is now unnecessary in the above example.
Put simply, when a given variable name is not assigned a value within a
function (by an assignment, or the *note def: 1661, *note class: 14df,
or *note import: 7f9. statements), references to the variable will be
looked up in the local namespace of the enclosing scope.  A more
detailed explanation of the rules, and a dissection of the
implementation, can be found in the PEP.

This change may cause some compatibility problems for code where the
same variable name is used both at the module level and as a local
variable within a function that contains further function definitions.
This seems rather unlikely though, since such code would have been
pretty confusing to read in the first place.

One side effect of the change is that the ‘from module import *’ and
‘exec’ statements have been made illegal inside a function scope under
certain conditions.  The Python reference manual has said all along that
‘from module import *’ is only legal at the top level of a module, but
the CPython interpreter has never enforced this before.  As part of the
implementation of nested scopes, the compiler which turns Python source
into bytecodes has to generate different code to access variables in a
containing scope.  ‘from module import *’ and ‘exec’ make it impossible
for the compiler to figure this out, because they add names to the local
namespace that are unknowable at compile time.  Therefore, if a function
contains function definitions or *note lambda: 14a5. expressions with
free variables, the compiler will flag this by raising a *note
SyntaxError: 18e. exception.

To make the preceding explanation a bit clearer, here’s an example:

     x = 1
     def f():
         # The next line is a syntax error
         exec 'x=2'
         def g():
             return x

Line 4 containing the ‘exec’ statement is a syntax error, since ‘exec’
would define a new local variable named ‘x’ whose value should be
accessed by ‘g()’.

This shouldn’t be much of a limitation, since ‘exec’ is rarely used in
most Python code (and when it is used, it’s often a sign of a poor
design anyway).

Vedi anche
..........

PEP 227(1) - Statically Nested Scopes

     Written and implemented by Jeremy Hylton.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0227/


File: python.info,  Node: New and Improved Modules<3>,  Next: Interpreter Changes and Fixes,  Prev: PEP 227 Nested Scopes,  Up: What’s New in Python 2 2

1.21.9 New and Improved Modules
-------------------------------

   * The *note xmlrpclib: 134. module was contributed to the standard
     library by Fredrik Lundh, providing support for writing XML-RPC
     clients.  XML-RPC is a simple remote procedure call protocol built
     on top of HTTP and XML. For example, the following snippet
     retrieves a list of RSS channels from the O’Reilly Network, and
     then lists the recent headlines for one channel:

          import xmlrpclib
          s = xmlrpclib.Server(
                'http://www.oreillynet.com/meerkat/xml-rpc/server.php')
          channels = s.meerkat.getChannels()
          # channels is a list of dictionaries, like this:
          # [{'id': 4, 'title': 'Freshmeat Daily News'}
          #  {'id': 190, 'title': '32Bits Online'},
          #  {'id': 4549, 'title': '3DGamers'}, ... ]

          # Get the items for one channel
          items = s.meerkat.getItems( {'channel': 4} )

          # 'items' is another list of dictionaries, like this:
          # [{'link': 'http://freshmeat.net/releases/52719/',
          #   'description': 'A utility which converts HTML to XSL FO.',
          #   'title': 'html2fo 0.3 (Default)'}, ... ]

     The *note SimpleXMLRPCServer: 135. module makes it easy to create
     straightforward XML-RPC servers.  See
     ‘http://xmlrpc.scripting.com/’ for more information about XML-RPC.

   * The new *note hmac: 6e. module implements the HMAC algorithm
     described by RFC 2104(1).  (Contributed by Gerhard Häring.)

   * Several functions that originally returned lengthy tuples now
     return pseudo-sequences that still behave like tuples but also have
     mnemonic attributes such as ‘memberst_mtime’ or *note tm_year:
     16ff.  The enhanced functions include *note stat(): 26d, *note
     fstat(): f8e, *note statvfs(): 1304, and *note fstatvfs(): f8f. in
     the *note os: a5. module, and *note localtime(): 1700, *note
     gmtime(): 13c8, and *note strptime(): 1634. in the *note time: f4.
     module.

     For example, to obtain a file’s size using the old tuples, you’d
     end up writing something like ‘file_size =
     os.stat(filename)[stat.ST_SIZE]’, but now this can be written more
     clearly as ‘file_size = os.stat(filename).st_size’.

     The original patch for this feature was contributed by Nick
     Mathewson.

   * The Python profiler has been extensively reworked and various
     errors in its output have been corrected.  (Contributed by Fred L.
     Drake, Jr.  and Tim Peters.)

   * The *note socket: d1. module can be compiled to support IPv6;
     specify the ‘--enable-ipv6’ option to Python’s configure script.
     (Contributed by Jun-ichiro «itojun» Hagino.)

   * Two new format characters were added to the *note struct: db.
     module for 64-bit integers on platforms that support the C long
     long type.  ‘q’ is for a signed 64-bit integer, and ‘Q’ is for an
     unsigned one.  The value is returned in Python’s long integer type.
     (Contributed by Tim Peters.)

   * In the interpreter’s interactive mode, there’s a new built-in
     function *note help(): ad6. that uses the *note pydoc: ba. module
     introduced in Python 2.1 to provide interactive help.
     ‘help(object)’ displays any available help text about 'object'.
     *note help(): ad6. with no argument puts you in an online help
     utility, where you can enter the names of functions, classes, or
     modules to read their help text.  (Contributed by Guido van Rossum,
     using Ka-Ping Yee’s *note pydoc: ba. module.)

   * Various bugfixes and performance improvements have been made to the
     SRE engine underlying the *note re: be. module.  For example, the
     *note re.sub(): 5a3. and *note re.split(): 5a2. functions have been
     rewritten in C. Another contributed patch speeds up certain Unicode
     character ranges by a factor of two, and a new *note finditer():
     1701. method that returns an iterator over all the non-overlapping
     matches in a given string.  (SRE is maintained by Fredrik Lundh.
     The BIGCHARSET patch was contributed by Martin von Löwis.)

   * The *note smtplib: cf. module now supports RFC 2487(2), «Secure
     SMTP over TLS», so it’s now possible to encrypt the SMTP traffic
     between a Python program and the mail transport agent being handed
     a message.  *note smtplib: cf. also supports SMTP authentication.
     (Contributed by Gerhard Häring.)

   * The *note imaplib: 78. module, maintained by Piers Lauder, has
     support for several new extensions: the NAMESPACE extension defined
     in RFC 2342(3), SORT, GETACL and SETACL. (Contributed by Anthony
     Baxter and Michel Pelletier.)

   * The ‘rfc822’ module’s parsing of email addresses is now compliant
     with RFC 2822(4), an update to RFC 822(5).  (The module’s name is
     'not' going to be changed to ‘rfc2822’.)  A new package, *note
     email: 3f, has also been added for parsing and generating e-mail
     messages.  (Contributed by Barry Warsaw, and arising out of his
     work on Mailman.)

   * The *note difflib: 3b. module now contains a new ‘Differ’ class for
     producing human-readable lists of changes (a «delta») between two
     sequences of lines of text.  There are also two generator
     functions, ‘ndiff()’ and ‘restore()’, which respectively return a
     delta from two sequences, or one of the original sequences from a
     delta.  (Grunt work contributed by David Goodger, from ndiff.py
     code by Tim Peters who then did the generatorization.)

   * New constants ‘ascii_letters’, ‘ascii_lowercase’, and
     ‘ascii_uppercase’ were added to the *note string: d8. module.
     There were several modules in the standard library that used
     ‘string.letters’ to mean the ranges A-Za-z, but that assumption is
     incorrect when locales are in use, because ‘string.letters’ varies
     depending on the set of legal characters defined by the current
     locale.  The buggy modules have all been fixed to use
     ‘ascii_letters’ instead.  (Reported by an unknown person; fixed by
     Fred L. Drake, Jr.)

   * The *note mimetypes: 93. module now makes it easier to use
     alternative MIME-type databases by the addition of a *note
     MimeTypes: 1702. class, which takes a list of filenames to be
     parsed.  (Contributed by Fred L. Drake, Jr.)

   * A *note Timer: 1361. class was added to the *note threading: f3.
     module that allows scheduling an activity to happen at some future
     time.  (Contributed by Itamar Shtull-Trauring.)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2104.html

   (2) https://datatracker.ietf.org/doc/html/rfc2487.html

   (3) https://datatracker.ietf.org/doc/html/rfc2342.html

   (4) https://datatracker.ietf.org/doc/html/rfc2822.html

   (5) https://datatracker.ietf.org/doc/html/rfc822.html


File: python.info,  Node: Interpreter Changes and Fixes,  Next: Other Changes and Fixes<3>,  Prev: New and Improved Modules<3>,  Up: What’s New in Python 2 2

1.21.10 Interpreter Changes and Fixes
-------------------------------------

Some of the changes only affect people who deal with the Python
interpreter at the C level because they’re writing Python extension
modules, embedding the interpreter, or just hacking on the interpreter
itself.  If you only write Python code, none of the changes described
here will affect you very much.

   * Profiling and tracing functions can now be implemented in C, which
     can operate at much higher speeds than Python-based functions and
     should reduce the overhead of profiling and tracing.  This will be
     of interest to authors of development environments for Python.  Two
     new C functions were added to Python’s API, *note
     PyEval_SetProfile(): 1704. and *note PyEval_SetTrace(): 663.  The
     existing *note sys.setprofile(): 1705. and *note sys.settrace():
     2e1. functions still exist, and have simply been changed to use the
     new C-level interface.  (Contributed by Fred L. Drake, Jr.)

   * Another low-level API, primarily of interest to implementers of
     Python debuggers and development tools, was added.  *note
     PyInterpreterState_Head(): 1706. and *note
     PyInterpreterState_Next(): 1707. let a caller walk through all the
     existing interpreter objects; *note
     PyInterpreterState_ThreadHead(): 1708. and *note
     PyThreadState_Next(): 1709. allow looping over all the thread
     states for a given interpreter.  (Contributed by David Beazley.)

   * The C-level interface to the garbage collector has been changed to
     make it easier to write extension types that support garbage
     collection and to debug misuses of the functions.  Various
     functions have slightly different semantics, so a bunch of
     functions had to be renamed.  Extensions that use the old API will
     still compile but will 'not' participate in garbage collection, so
     updating them for 2.2 should be considered fairly high priority.

     To upgrade an extension module to the new API, perform the
     following steps:

   * Rename ‘Py_TPFLAGS_GC’ to *note Py_TPFLAGS_HAVE_GC: 982.

   * 
     Use *note PyObject_GC_New(): c9b. or *note PyObject_GC_NewVar(): c9c. to allocate

          objects, and *note PyObject_GC_Del(): 170a. to deallocate
          them.

   * Rename ‘PyObject_GC_Init()’ to *note PyObject_GC_Track(): 170b. and
     ‘PyObject_GC_Fini()’ to *note PyObject_GC_UnTrack(): 170c.

   * Remove ‘PyGC_HEAD_SIZE’ from object size calculations.

   * Remove calls to ‘PyObject_AS_GC()’ and ‘PyObject_FROM_GC()’.

   * A new ‘et’ format sequence was added to *note PyArg_ParseTuple():
     3c1.; ‘et’ takes both a parameter and an encoding name, and
     converts the parameter to the given encoding if the parameter turns
     out to be a Unicode string, or leaves it alone if it’s an 8-bit
     string, assuming it to already be in the desired encoding.  This
     differs from the ‘es’ format character, which assumes that 8-bit
     strings are in Python’s default ASCII encoding and converts them to
     the specified new encoding.  (Contributed by M.-A. Lemburg, and
     used for the MBCS support on Windows described in the following
     section.)

   * A different argument parsing function, *note PyArg_UnpackTuple():
     170d, has been added that’s simpler and presumably faster.  Instead
     of specifying a format string, the caller simply gives the minimum
     and maximum number of arguments expected, and a set of pointers to
     *note PyObject: 5df.* variables that will be filled in with
     argument values.

   * Two new flags *note METH_NOARGS: 16db. and *note METH_O: 170e. are
     available in method definition tables to simplify implementation of
     methods with no arguments or a single untyped argument.  Calling
     such methods is more efficient than calling a corresponding method
     that uses *note METH_VARARGS: 170f.  Also, the old ‘METH_OLDARGS’
     style of writing C methods is now officially deprecated.

   * Two new wrapper functions, *note PyOS_snprintf(): 1710. and *note
     PyOS_vsnprintf(): 1711. were added to provide cross-platform
     implementations for the relatively new ‘snprintf()’ and
     ‘vsnprintf()’ C lib APIs.  In contrast to the standard ‘sprintf()’
     and ‘vsprintf()’ functions, the Python versions check the bounds of
     the buffer used to protect against buffer overruns.  (Contributed
     by M.-A. Lemburg.)

   * The *note _PyTuple_Resize(): 1712. function has lost an unused
     parameter, so now it takes 2 parameters instead of 3.  The third
     argument was never used, and can simply be discarded when porting
     code from earlier versions to Python 2.2.


File: python.info,  Node: Other Changes and Fixes<3>,  Next: Acknowledgements<6>,  Prev: Interpreter Changes and Fixes,  Up: What’s New in Python 2 2

1.21.11 Other Changes and Fixes
-------------------------------

As usual there were a bunch of other improvements and bugfixes scattered
throughout the source tree.  A search through the CVS change logs finds
there were 527 patches applied and 683 bugs fixed between Python 2.1 and
2.2; 2.2.1 applied 139 patches and fixed 143 bugs; 2.2.2 applied 106
patches and fixed 82 bugs.  These figures are likely to be
underestimates.

Some of the more notable changes are:

   * The code for the MacOS port for Python, maintained by Jack Jansen,
     is now kept in the main Python CVS tree, and many changes have been
     made to support MacOS X.

     The most significant change is the ability to build Python as a
     framework, enabled by supplying the ‘--enable-framework’ option to
     the configure script when compiling Python.  According to Jack
     Jansen, «This installs a self-contained Python installation plus
     the OS X framework «glue» into
     ‘/Library/Frameworks/Python.framework’ (or another location of
     choice).  For now there is little immediate added benefit to this
     (actually, there is the disadvantage that you have to change your
     PATH to be able to find Python), but it is the basis for creating a
     full-blown Python application, porting the MacPython IDE, possibly
     using Python as a standard OSA scripting language and much more.»

     Most of the MacPython toolbox modules, which interface to MacOS
     APIs such as windowing, QuickTime, scripting, etc.  have been
     ported to OS X, but they’ve been left commented out in ‘setup.py’.
     People who want to experiment with these modules can uncomment them
     manually.

   * Keyword arguments passed to built-in functions that don’t take them
     now cause a *note TypeError: 198. exception to be raised, with the
     message «'function' takes no keyword arguments».

   * Weak references, added in Python 2.1 as an extension module, are
     now part of the core because they’re used in the implementation of
     new-style classes.  The *note ReferenceError: 1714. exception has
     therefore moved from the *note weakref: 11a. module to become a
     built-in exception.

   * A new script, ‘Tools/scripts/cleanfuture.py’ by Tim Peters,
     automatically removes obsolete ‘__future__’ statements from Python
     source code.

   * An additional 'flags' argument has been added to the built-in
     function *note compile(): 4b2, so the behaviour of ‘__future__’
     statements can now be correctly observed in simulated shells, such
     as those presented by IDLE and other development environments.
     This is described in PEP 264(1).  (Contributed by Michael Hudson.)

   * The new license introduced with Python 1.6 wasn’t GPL-compatible.
     This is fixed by some minor textual changes to the 2.2 license, so
     it’s now legal to embed Python inside a GPLed program again.  Note
     that Python itself is not GPLed, but instead is under a license
     that’s essentially equivalent to the BSD license, same as it always
     was.  The license changes were also applied to the Python 2.0.1 and
     2.1.1 releases.

   * When presented with a Unicode filename on Windows, Python will now
     convert it to an MBCS encoded string, as used by the Microsoft file
     APIs.  As MBCS is explicitly used by the file APIs, Python’s choice
     of ASCII as the default encoding turns out to be an annoyance.  On
     Unix, the locale’s character set is used if
     ‘locale.nl_langinfo(CODESET)’ is available.  (Windows support was
     contributed by Mark Hammond with assistance from Marc-André
     Lemburg.  Unix support was added by Martin von Löwis.)

   * Large file support is now enabled on Windows.  (Contributed by Tim
     Peters.)

   * The ‘Tools/scripts/ftpmirror.py’ script now parses a ‘.netrc’ file,
     if you have one.  (Contributed by Mike Romberg.)

   * Some features of the object returned by the ‘xrange()’ function are
     now deprecated, and trigger warnings when they’re accessed; they’ll
     disappear in Python 2.3.  ‘xrange’ objects tried to pretend they
     were full sequence types by supporting slicing, sequence
     multiplication, and the *note in: 34b. operator, but these features
     were rarely used and therefore buggy.  The ‘tolist()’ method and
     the ‘start’, ‘stop’, and ‘step’ attributes are also being
     deprecated.  At the C level, the fourth argument to the
     ‘PyRange_New()’ function, ‘repeat’, has also been deprecated.

   * There were a bunch of patches to the dictionary implementation,
     mostly to fix potential core dumps if a dictionary contains objects
     that sneakily changed their hash value, or mutated the dictionary
     they were contained in.  For a while python-dev fell into a gentle
     rhythm of Michael Hudson finding a case that dumped core, Tim
     Peters fixing the bug, Michael finding another case, and round and
     round it went.

   * On Windows, Python can now be compiled with Borland C thanks to a
     number of patches contributed by Stephen Hansen, though the result
     isn’t fully functional yet.  (But this 'is' progress…)

   * Another Windows enhancement: Wise Solutions generously offered
     PythonLabs use of their InstallerMaster 8.1 system.  Earlier
     PythonLabs Windows installers used Wise 5.0a, which was beginning
     to show its age.  (Packaged up by Tim Peters.)

   * Files ending in ‘.pyw’ can now be imported on Windows.  ‘.pyw’ is a
     Windows-only thing, used to indicate that a script needs to be run
     using PYTHONW.EXE instead of PYTHON.EXE in order to prevent a DOS
     console from popping up to display the output.  This patch makes it
     possible to import such scripts, in case they’re also usable as
     modules.  (Implemented by David Bolen.)

   * On platforms where Python uses the C ‘dlopen()’ function to load
     extension modules, it’s now possible to set the flags used by
     ‘dlopen()’ using the *note sys.getdlopenflags(): 1715. and *note
     sys.setdlopenflags(): 1327. functions.  (Contributed by Bram
     Stolk.)

   * The *note pow(): 1a4. built-in function no longer supports 3
     arguments when floating-point numbers are supplied.  ‘pow(x, y, z)’
     returns ‘(x**y) % z’, but this is never useful for floating-point
     numbers, and the final result varies unpredictably depending on the
     platform.  A call such as ‘pow(2.0, 8.0, 7.0)’ will now raise a
     *note TypeError: 198. exception.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0264/


File: python.info,  Node: Acknowledgements<6>,  Prev: Other Changes and Fixes<3>,  Up: What’s New in Python 2 2

1.21.12 Acknowledgements
------------------------

The author would like to thank the following people for offering
suggestions, corrections and assistance with various drafts of this
article: Fred Bremmer, Keith Briggs, Andrew Dalke, Fred L. Drake, Jr.,
Carel Fellinger, David Goodger, Mark Hammond, Stephen Hansen, Michael
Hudson, Jack Jansen, Marc-André Lemburg, Martin von Löwis, Fredrik
Lundh, Michael McLay, Nick Mathewson, Paul Moore, Gustavo Niemeyer, Don
O’Donnell, Joonas Paalasma, Tim Peters, Jens Quade, Tom Reinhardt, Neil
Schemenauer, Guido van Rossum, Greg Ward, Edward Welbourne.


File: python.info,  Node: What’s New in Python 2 1,  Next: What’s New in Python 2 0,  Prev: What’s New in Python 2 2,  Up: Novità in Python

1.22 What’s New in Python 2.1
=============================


Author: A.M. Kuchling

* Menu:

* Introduction: Introduction<2>.
* PEP 227; Nested Scopes: PEP 227 Nested Scopes<2>.
* PEP 236; __future__ Directives: PEP 236 __future__ Directives.
* PEP 207; Rich Comparisons: PEP 207 Rich Comparisons.
* PEP 230; Warning Framework: PEP 230 Warning Framework.
* PEP 229; New Build System: PEP 229 New Build System.
* PEP 205; Weak References: PEP 205 Weak References.
* PEP 232; Function Attributes: PEP 232 Function Attributes.
* PEP 235; Importing Modules on Case-Insensitive Platforms: PEP 235 Importing Modules on Case-Insensitive Platforms.
* PEP 217; Interactive Display Hook: PEP 217 Interactive Display Hook.
* PEP 208; New Coercion Model: PEP 208 New Coercion Model.
* PEP 241; Metadata in Python Packages: PEP 241 Metadata in Python Packages.
* New and Improved Modules: New and Improved Modules<4>.
* Other Changes and Fixes: Other Changes and Fixes<4>.
* Acknowledgements: Acknowledgements<7>.


File: python.info,  Node: Introduction<2>,  Next: PEP 227 Nested Scopes<2>,  Up: What’s New in Python 2 1

1.22.1 Introduction
-------------------

This article explains the new features in Python 2.1.  While there
aren’t as many changes in 2.1 as there were in Python 2.0, there are
still some pleasant surprises in store.  2.1 is the first release to be
steered through the use of Python Enhancement Proposals, or PEPs, so
most of the sizable changes have accompanying PEPs that provide more
complete documentation and a design rationale for the change.  This
article doesn’t attempt to document the new features completely, but
simply provides an overview of the new features for Python programmers.
Refer to the Python 2.1 documentation, or to the specific PEP, for more
details about any new feature that particularly interests you.

One recent goal of the Python development team has been to accelerate
the pace of new releases, with a new release coming every 6 to 9 months.
2.1 is the first release to come out at this faster pace, with the first
alpha appearing in January, 3 months after the final version of 2.0 was
released.

The final release of Python 2.1 was made on April 17, 2001.


File: python.info,  Node: PEP 227 Nested Scopes<2>,  Next: PEP 236 __future__ Directives,  Prev: Introduction<2>,  Up: What’s New in Python 2 1

1.22.2 PEP 227: Nested Scopes
-----------------------------

The largest change in Python 2.1 is to Python’s scoping rules.  In
Python 2.0, at any given time there are at most three namespaces used to
look up variable names: local, module-level, and the built-in namespace.
This often surprised people because it didn’t match their intuitive
expectations.  For example, a nested recursive function definition
doesn’t work:

     def f():
         ...
         def g(value):
             ...
             return g(value-1) + 1
         ...

The function ‘g()’ will always raise a *note NameError: 452. exception,
because the binding of the name ‘g’ isn’t in either its local namespace
or in the module-level namespace.  This isn’t much of a problem in
practice (how often do you recursively define interior functions like
this?), but this also made using the *note lambda: 14a5. expression
clumsier, and this was a problem in practice.  In code which uses *note
lambda: 14a5. you can often find local variables being copied by passing
them as the default values of arguments.

     def find(self, name):
         "Return list of any entries equal to 'name'"
         L = filter(lambda x, name=name: x == name,
                    self.list_attribute)
         return L

The readability of Python code written in a strongly functional style
suffers greatly as a result.

The most significant change to Python 2.1 is that static scoping has
been added to the language to fix this problem.  As a first effect, the
‘name=name’ default argument is now unnecessary in the above example.
Put simply, when a given variable name is not assigned a value within a
function (by an assignment, or the *note def: 1661, *note class: 14df,
or *note import: 7f9. statements), references to the variable will be
looked up in the local namespace of the enclosing scope.  A more
detailed explanation of the rules, and a dissection of the
implementation, can be found in the PEP.

This change may cause some compatibility problems for code where the
same variable name is used both at the module level and as a local
variable within a function that contains further function definitions.
This seems rather unlikely though, since such code would have been
pretty confusing to read in the first place.

One side effect of the change is that the ‘from module import *’ and
‘exec’ statements have been made illegal inside a function scope under
certain conditions.  The Python reference manual has said all along that
‘from module import *’ is only legal at the top level of a module, but
the CPython interpreter has never enforced this before.  As part of the
implementation of nested scopes, the compiler which turns Python source
into bytecodes has to generate different code to access variables in a
containing scope.  ‘from module import *’ and ‘exec’ make it impossible
for the compiler to figure this out, because they add names to the local
namespace that are unknowable at compile time.  Therefore, if a function
contains function definitions or *note lambda: 14a5. expressions with
free variables, the compiler will flag this by raising a *note
SyntaxError: 18e. exception.

To make the preceding explanation a bit clearer, here’s an example:

     x = 1
     def f():
         # The next line is a syntax error
         exec 'x=2'
         def g():
             return x

Line 4 containing the ‘exec’ statement is a syntax error, since ‘exec’
would define a new local variable named ‘x’ whose value should be
accessed by ‘g()’.

This shouldn’t be much of a limitation, since ‘exec’ is rarely used in
most Python code (and when it is used, it’s often a sign of a poor
design anyway).

Compatibility concerns have led to nested scopes being introduced
gradually; in Python 2.1, they aren’t enabled by default, but can be
turned on within a module by using a future statement as described in
PEP 236(1).  (See the following section for further discussion of PEP
236(2).)  In Python 2.2, nested scopes will become the default and there
will be no way to turn them off, but users will have had all of 2.1’s
lifetime to fix any breakage resulting from their introduction.

Vedi anche
..........

PEP 227(3) - Statically Nested Scopes

     Written and implemented by Jeremy Hylton.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0236/

   (2) https://peps.python.org/pep-0236/

   (3) https://peps.python.org/pep-0227/


File: python.info,  Node: PEP 236 __future__ Directives,  Next: PEP 207 Rich Comparisons,  Prev: PEP 227 Nested Scopes<2>,  Up: What’s New in Python 2 1

1.22.3 PEP 236: __future__ Directives
-------------------------------------

The reaction to nested scopes was widespread concern about the dangers
of breaking code with the 2.1 release, and it was strong enough to make
the Pythoneers take a more conservative approach.  This approach
consists of introducing a convention for enabling optional functionality
in release N that will become compulsory in release N+1.

The syntax uses a ‘from...import’ statement using the reserved module
name *note __future__: 0.  Nested scopes can be enabled by the following
statement:

     from __future__ import nested_scopes

While it looks like a normal *note import: 7f9. statement, it’s not;
there are strict rules on where such a future statement can be put.
They can only be at the top of a module, and must precede any Python
code or regular ‘import’ statements.  This is because such statements
can affect how the Python bytecode compiler parses code and generates
bytecode, so they must precede any statement that will result in
bytecodes being produced.

Vedi anche
..........

PEP 236(1) - Back to the *note __future__: 0.

     Written by Tim Peters, and primarily implemented by Jeremy Hylton.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0236/


File: python.info,  Node: PEP 207 Rich Comparisons,  Next: PEP 230 Warning Framework,  Prev: PEP 236 __future__ Directives,  Up: What’s New in Python 2 1

1.22.4 PEP 207: Rich Comparisons
--------------------------------

In earlier versions, Python’s support for implementing comparisons on
user-defined classes and extension types was quite simple.  Classes
could implement a ‘__cmp__()’ method that was given two instances of a
class, and could only return 0 if they were equal or +1 or -1 if they
weren’t; the method couldn’t raise an exception or return anything other
than a Boolean value.  Users of Numeric Python often found this model
too weak and restrictive, because in the number-crunching programs that
numeric Python is used for, it would be more useful to be able to
perform elementwise comparisons of two matrices, returning a matrix
containing the results of a given comparison for each element.  If the
two matrices are of different sizes, then the compare has to be able to
raise an exception to signal the error.

In Python 2.1, rich comparisons were added in order to support this
need.  Python classes can now individually overload each of the ‘<’,
‘<=’, ‘>’, ‘>=’, ‘==’, and ‘!=’ operations.  The new magic method names
are:

Operation       Method name
                
---------------------------------------------
                
‘<’             *note __lt__(): 14a8.
                
                
‘<=’            *note __le__(): 1512.
                
                
‘>’             *note __gt__(): 1513.
                
                
‘>=’            *note __ge__(): 1514.
                
                
‘==’            *note __eq__(): cf4.
                
                
‘!=’            *note __ne__(): 171e.
                

(The magic methods are named after the corresponding Fortran operators
‘.LT.’.  ‘.LE.’, &c.  Numeric programmers are almost certainly quite
familiar with these names and will find them easy to remember.)

Each of these magic methods is of the form ‘method(self, other)’, where
‘self’ will be the object on the left-hand side of the operator, while
‘other’ will be the object on the right-hand side.  For example, the
expression ‘A < B’ will cause ‘A.__lt__(B)’ to be called.

Each of these magic methods can return anything at all: a Boolean, a
matrix, a list, or any other Python object.  Alternatively they can
raise an exception if the comparison is impossible, inconsistent, or
otherwise meaningless.

The built-in ‘cmp(A,B)’ function can use the rich comparison machinery,
and now accepts an optional argument specifying which comparison
operation to use; this is given as one of the strings ‘"<"’, ‘"<="’,
‘">"’, ‘">="’, ‘"=="’, or ‘"!="’.  If called without the optional third
argument, ‘cmp()’ will only return -1, 0, or +1 as in previous versions
of Python; otherwise it will call the appropriate method and can return
any Python object.

There are also corresponding changes of interest to C programmers;
there’s a new slot ‘tp_richcmp’ in type objects and an API for
performing a given rich comparison.  I won’t cover the C API here, but
will refer you to PEP 207(1), or to 2.1’s C API documentation, for the
full list of related functions.

Vedi anche
..........

PEP 207(2) - Rich Comparisons

     Written by Guido van Rossum, heavily based on earlier work by David
     Ascher, and implemented by Guido van Rossum.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0207/

   (2) https://peps.python.org/pep-0207/


File: python.info,  Node: PEP 230 Warning Framework,  Next: PEP 229 New Build System,  Prev: PEP 207 Rich Comparisons,  Up: What’s New in Python 2 1

1.22.5 PEP 230: Warning Framework
---------------------------------

Over its 10 years of existence, Python has accumulated a certain number
of obsolete modules and features along the way.  It’s difficult to know
when a feature is safe to remove, since there’s no way of knowing how
much code uses it — perhaps no programs depend on the feature, or
perhaps many do.  To enable removing old features in a more structured
way, a warning framework was added.  When the Python developers want to
get rid of a feature, it will first trigger a warning in the next
version of Python.  The following Python version can then drop the
feature, and users will have had a full release cycle to remove uses of
the old feature.

Python 2.1 adds the warning framework to be used in this scheme.  It
adds a *note warnings: 118. module that provide functions to issue
warnings, and to filter out warnings that you don’t want to be
displayed.  Third-party modules can also use this framework to deprecate
old features that they no longer wish to support.

For example, in Python 2.1 the ‘regex’ module is deprecated, so
importing it causes a warning to be printed:

     >>> import regex
     __main__:1: DeprecationWarning: the regex module
              is deprecated; please use the re module
     >>>

Warnings can be issued by calling the *note warnings.warn(): 1720.
function:

     warnings.warn("feature X no longer supported")

The first parameter is the warning message; an additional optional
parameters can be used to specify a particular warning category.

Filters can be added to disable certain warnings; a regular expression
pattern can be applied to the message or to the module name in order to
suppress a warning.  For example, you may have a program that uses the
‘regex’ module and not want to spare the time to convert it to use the
*note re: be. module right now.  The warning can be suppressed by
calling

     import warnings
     warnings.filterwarnings(action = 'ignore',
                             message='.*regex module is deprecated',
                             category=DeprecationWarning,
                             module = '__main__')

This adds a filter that will apply only to warnings of the class *note
DeprecationWarning: 1a3. triggered in the *note __main__: 1. module, and
applies a regular expression to only match the message about the ‘regex’
module being deprecated, and will cause such warnings to be ignored.
Warnings can also be printed only once, printed every time the offending
code is executed, or turned into exceptions that will cause the program
to stop (unless the exceptions are caught in the usual way, of course).

Functions were also added to Python’s C API for issuing warnings; refer
to PEP 230 or to Python’s API documentation for the details.

Vedi anche
..........

PEP 5(1) - Guidelines for Language Evolution

     Written by Paul Prescod, to specify procedures to be followed when
     removing old features from Python.  The policy described in this
     PEP hasn’t been officially adopted, but the eventual policy
     probably won’t be too different from Prescod’s proposal.

PEP 230(2) - Warning Framework

     Written and implemented by Guido van Rossum.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0005/

   (2) https://peps.python.org/pep-0230/


File: python.info,  Node: PEP 229 New Build System,  Next: PEP 205 Weak References,  Prev: PEP 230 Warning Framework,  Up: What’s New in Python 2 1

1.22.6 PEP 229: New Build System
--------------------------------

When compiling Python, the user had to go in and edit the
‘Modules/Setup’ file in order to enable various additional modules; the
default set is relatively small and limited to modules that compile on
most Unix platforms.  This means that on Unix platforms with many more
features, most notably Linux, Python installations often don’t contain
all useful modules they could.

Python 2.0 added the Distutils, a set of modules for distributing and
installing extensions.  In Python 2.1, the Distutils are used to compile
much of the standard library of extension modules, autodetecting which
ones are supported on the current machine.  It’s hoped that this will
make Python installations easier and more featureful.

Instead of having to edit the ‘Modules/Setup’ file in order to enable
modules, a ‘setup.py’ script in the top directory of the Python source
distribution is run at build time, and attempts to discover which
modules can be enabled by examining the modules and header files on the
system.  If a module is configured in ‘Modules/Setup’, the ‘setup.py’
script won’t attempt to compile that module and will defer to the
‘Modules/Setup’ file’s contents.  This provides a way to specific any
strange command-line flags or libraries that are required for a specific
platform.

In another far-reaching change to the build mechanism, Neil Schemenauer
restructured things so Python now uses a single makefile that isn’t
recursive, instead of makefiles in the top directory and in each of the
‘Python/’, ‘Parser/’, ‘Objects/’, and ‘Modules/’ subdirectories.  This
makes building Python faster and also makes hacking the Makefiles
clearer and simpler.

Vedi anche
..........

PEP 229(1) - Using Distutils to Build Python

     Written and implemented by A.M. Kuchling.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0229/


File: python.info,  Node: PEP 205 Weak References,  Next: PEP 232 Function Attributes,  Prev: PEP 229 New Build System,  Up: What’s New in Python 2 1

1.22.7 PEP 205: Weak References
-------------------------------

Weak references, available through the *note weakref: 11a. module, are a
minor but useful new data type in the Python programmer’s toolbox.

Storing a reference to an object (say, in a dictionary or a list) has
the side effect of keeping that object alive forever.  There are a few
specific cases where this behaviour is undesirable, object caches being
the most common one, and another being circular references in data
structures such as trees.

For example, consider a memoizing function that caches the results of
another function ‘f(x)’ by storing the function’s argument and its
result in a dictionary:

     _cache = {}
     def memoize(x):
         if _cache.has_key(x):
             return _cache[x]

         retval = f(x)

         # Cache the returned object
         _cache[x] = retval

         return retval

This version works for simple things such as integers, but it has a side
effect; the ‘_cache’ dictionary holds a reference to the return values,
so they’ll never be deallocated until the Python process exits and
cleans up.  This isn’t very noticeable for integers, but if ‘f()’
returns an object, or a data structure that takes up a lot of memory,
this can be a problem.

Weak references provide a way to implement a cache that won’t keep
objects alive beyond their time.  If an object is only accessible
through weak references, the object will be deallocated and the weak
references will now indicate that the object it referred to no longer
exists.  A weak reference to an object 'obj' is created by calling ‘wr =
weakref.ref(obj)’.  The object being referred to is returned by calling
the weak reference as if it were a function: ‘wr()’.  It will return the
referenced object, or ‘None’ if the object no longer exists.

This makes it possible to write a ‘memoize()’ function whose cache
doesn’t keep objects alive, by storing weak references in the cache.

     _cache = {}
     def memoize(x):
         if _cache.has_key(x):
             obj = _cache[x]()
             # If weak reference object still exists,
             # return it
             if obj is not None: return obj

         retval = f(x)

         # Cache a weak reference
         _cache[x] = weakref.ref(retval)

         return retval

The *note weakref: 11a. module also allows creating proxy objects which
behave like weak references — an object referenced only by proxy objects
is deallocated – but instead of requiring an explicit call to retrieve
the object, the proxy transparently forwards all operations to the
object as long as the object still exists.  If the object is
deallocated, attempting to use a proxy will cause a
‘weakref.ReferenceError’ exception to be raised.

     proxy = weakref.proxy(obj)
     proxy.attr   # Equivalent to obj.attr
     proxy.meth() # Equivalent to obj.meth()
     del obj
     proxy.attr   # raises weakref.ReferenceError

Vedi anche
..........

PEP 205(1) - Weak References

     Written and implemented by Fred L. Drake, Jr.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0205/


File: python.info,  Node: PEP 232 Function Attributes,  Next: PEP 235 Importing Modules on Case-Insensitive Platforms,  Prev: PEP 205 Weak References,  Up: What’s New in Python 2 1

1.22.8 PEP 232: Function Attributes
-----------------------------------

In Python 2.1, functions can now have arbitrary information attached to
them.  People were often using docstrings to hold information about
functions and methods, because the *note __doc__: 13e1. attribute was
the only way of attaching any information to a function.  For example,
in the Zope web application server, functions are marked as safe for
public access by having a docstring, and in John Aycock’s SPARK parsing
framework, docstrings hold parts of the BNF grammar to be parsed.  This
overloading is unfortunate, since docstrings are really intended to hold
a function’s documentation; for example, it means you can’t properly
document functions intended for private use in Zope.

Arbitrary attributes can now be set and retrieved on functions using the
regular Python syntax:

     def f(): pass

     f.publish = 1
     f.secure = 1
     f.grammar = "A ::= B (C D)*"

The dictionary containing attributes can be accessed as the function’s
*note __dict__: 14da.  Unlike the *note __dict__: e59. attribute of
class instances, in functions you can actually assign a new dictionary
to *note __dict__: 14da, though the new value is restricted to a regular
Python dictionary; you 'can’t' be tricky and set it to a ‘UserDict’
instance, or any other random object that behaves like a mapping.

Vedi anche
..........

PEP 232(1) - Function Attributes

     Written and implemented by Barry Warsaw.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0232/


File: python.info,  Node: PEP 235 Importing Modules on Case-Insensitive Platforms,  Next: PEP 217 Interactive Display Hook,  Prev: PEP 232 Function Attributes,  Up: What’s New in Python 2 1

1.22.9 PEP 235: Importing Modules on Case-Insensitive Platforms
---------------------------------------------------------------

Some operating systems have filesystems that are case-insensitive, MacOS
and Windows being the primary examples; on these systems, it’s
impossible to distinguish the filenames ‘FILE.PY’ and ‘file.py’, even
though they do store the file’s name in its original case (they’re
case-preserving, too).

In Python 2.1, the *note import: 7f9. statement will work to simulate
case-sensitivity on case-insensitive platforms.  Python will now search
for the first case-sensitive match by default, raising an *note
ImportError: 65b. if no such file is found, so ‘import file’ will not
import a module named ‘FILE.PY’.  Case-insensitive matching can be
requested by setting the *note PYTHONCASEOK: b57. environment variable
before starting the Python interpreter.


File: python.info,  Node: PEP 217 Interactive Display Hook,  Next: PEP 208 New Coercion Model,  Prev: PEP 235 Importing Modules on Case-Insensitive Platforms,  Up: What’s New in Python 2 1

1.22.10 PEP 217: Interactive Display Hook
-----------------------------------------

When using the Python interpreter interactively, the output of commands
is displayed using the built-in *note repr(): 1c1. function.  In Python
2.1, the variable *note sys.displayhook(): 1726. can be set to a
callable object which will be called instead of *note repr(): 1c1.  For
example, you can set it to a special pretty-printing function:

     >>> # Create a recursive data structure
     ... L = [1,2,3]
     >>> L.append(L)
     >>> L # Show Python's default output
     [1, 2, 3, [...]]
     >>> # Use pprint.pprint() as the display function
     ... import sys, pprint
     >>> sys.displayhook = pprint.pprint
     >>> L
     [1, 2, 3,  <Recursion on list with id=135143996>]
     >>>

Vedi anche
..........

PEP 217(1) - Display Hook for Interactive Use

     Written and implemented by Moshe Zadka.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0217/


File: python.info,  Node: PEP 208 New Coercion Model,  Next: PEP 241 Metadata in Python Packages,  Prev: PEP 217 Interactive Display Hook,  Up: What’s New in Python 2 1

1.22.11 PEP 208: New Coercion Model
-----------------------------------

How numeric coercion is done at the C level was significantly modified.
This will only affect the authors of C extensions to Python, allowing
them more flexibility in writing extension types that support numeric
operations.

Extension types can now set the type flag ‘Py_TPFLAGS_CHECKTYPES’ in
their ‘PyTypeObject’ structure to indicate that they support the new
coercion model.  In such extension types, the numeric slot functions can
no longer assume that they’ll be passed two arguments of the same type;
instead they may be passed two arguments of differing types, and can
then perform their own internal coercion.  If the slot function is
passed a type it can’t handle, it can indicate the failure by returning
a reference to the ‘Py_NotImplemented’ singleton value.  The numeric
functions of the other type will then be tried, and perhaps they can
handle the operation; if the other type also returns
‘Py_NotImplemented’, then a *note TypeError: 198. will be raised.
Numeric methods written in Python can also return ‘Py_NotImplemented’,
causing the interpreter to act as if the method did not exist (perhaps
raising a *note TypeError: 198, perhaps trying another object’s numeric
methods).

Vedi anche
..........

PEP 208(1) - Reworking the Coercion Model

     Written and implemented by Neil Schemenauer, heavily based upon
     earlier work by Marc-André Lemburg.  Read this to understand the
     fine points of how numeric operations will now be processed at the
     C level.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0208/


File: python.info,  Node: PEP 241 Metadata in Python Packages,  Next: New and Improved Modules<4>,  Prev: PEP 208 New Coercion Model,  Up: What’s New in Python 2 1

1.22.12 PEP 241: Metadata in Python Packages
--------------------------------------------

A common complaint from Python users is that there’s no single catalog
of all the Python modules in existence.  T. Middleton’s Vaults of
Parnassus at ‘www.vex.net/parnassus/’ (retired in February 2009,
available in the Internet Archive Wayback Machine(1)) was the largest
catalog of Python modules, but registering software at the Vaults is
optional, and many people did not bother.

As a first small step toward fixing the problem, Python software
packaged using the Distutils ‘sdist’ command will include a file named
‘PKG-INFO’ containing information about the package such as its name,
version, and author (metadata, in cataloguing terminology).  PEP 241(2)
contains the full list of fields that can be present in the ‘PKG-INFO’
file.  As people began to package their software using Python 2.1, more
and more packages will include metadata, making it possible to build
automated cataloguing systems and experiment with them.  With the result
experience, perhaps it’ll be possible to design a really good catalog
and then build support for it into Python 2.2.  For example, the
Distutils ‘sdist’ and ‘bdist_*’ commands could support an ‘upload’
option that would automatically upload your package to a catalog server.

You can start creating packages containing ‘PKG-INFO’ even if you’re not
using Python 2.1, since a new release of the Distutils will be made for
users of earlier Python versions.  Version 1.0.2 of the Distutils
includes the changes described in PEP 241(3), as well as various
bugfixes and enhancements.  It will be available from the Distutils SIG
at ‘https://www.python.org/community/sigs/current/distutils-sig/’.

Vedi anche
..........

PEP 241(4) - Metadata for Python Software Packages

     Written and implemented by A.M. Kuchling.

PEP 243(5) - Module Repository Upload Mechanism

     Written by Sean Reifschneider, this draft PEP describes a proposed
     mechanism for uploading Python packages to a central server.

   ---------- Footnotes ----------

   (1) 
https://web.archive.org/web/20090130140102/http://www.vex.net/parnassus/

   (2) https://peps.python.org/pep-0241/

   (3) https://peps.python.org/pep-0241/

   (4) https://peps.python.org/pep-0241/

   (5) https://peps.python.org/pep-0243/


File: python.info,  Node: New and Improved Modules<4>,  Next: Other Changes and Fixes<4>,  Prev: PEP 241 Metadata in Python Packages,  Up: What’s New in Python 2 1

1.22.13 New and Improved Modules
--------------------------------

   * Ka-Ping Yee contributed two new modules: ‘inspect.py’, a module for
     getting information about live Python code, and ‘pydoc.py’, a
     module for interactively converting docstrings to HTML or text.  As
     a bonus, ‘Tools/scripts/pydoc’, which is now automatically
     installed, uses ‘pydoc.py’ to display documentation given a Python
     module, package, or class name.  For example, ‘pydoc xml.dom’
     displays the following:

          Python Library Documentation: package xml.dom in xml

          NAME
              xml.dom - W3C Document Object Model implementation for Python.

          FILE
              /usr/local/lib/python2.1/xml/dom/__init__.pyc

          DESCRIPTION
              The Python mapping of the Document Object Model is documented in the
              Python Library Reference in the section on the xml.dom package.

              This package contains the following modules:
                ...

     ‘pydoc’ also includes a Tk-based interactive help browser.  ‘pydoc’
     quickly becomes addictive; try it out!

   * Two different modules for unit testing were added to the standard
     library.  The *note doctest: 3e. module, contributed by Tim Peters,
     provides a testing framework based on running embedded examples in
     docstrings and comparing the results against the expected output.
     PyUnit, contributed by Steve Purcell, is a unit testing framework
     inspired by JUnit, which was in turn an adaptation of Kent Beck’s
     Smalltalk testing framework.  See ‘https://pyunit.sourceforge.net/’
     for more information about PyUnit.

   * The *note difflib: 3b. module contains a class, *note
     SequenceMatcher: 121b, which compares two sequences and computes
     the changes required to transform one sequence into the other.  For
     example, this module can be used to write a tool similar to the
     Unix ‘diff’ program, and in fact the sample program
     ‘Tools/scripts/ndiff.py’ demonstrates how to write such a script.

   * *note curses.panel: 31, a wrapper for the panel library, part of
     ncurses and of SYSV curses, was contributed by Thomas Gellekum.
     The panel library provides windows with the additional feature of
     depth.  Windows can be moved higher or lower in the depth ordering,
     and the panel library figures out where panels overlap and which
     sections are visible.

   * The PyXML package has gone through a few releases since Python 2.0,
     and Python 2.1 includes an updated version of the *note xml: 126.
     package.  Some of the noteworthy changes include support for Expat
     1.2 and later versions, the ability for Expat parsers to handle
     files in any encoding supported by Python, and various bugfixes for
     SAX, DOM, and the ‘minidom’ module.

   * Ping also contributed another hook for handling uncaught
     exceptions.  *note sys.excepthook(): a0e. can be set to a callable
     object.  When an exception isn’t caught by any *note try:
     8f9.…*note except: 1ab. blocks, the exception will be passed to
     *note sys.excepthook(): a0e, which can then do whatever it likes.
     At the Ninth Python Conference, Ping demonstrated an application
     for this hook: printing an extended traceback that not only lists
     the stack frames, but also lists the function arguments and the
     local variables for each frame.

   * Various functions in the *note time: f4. module, such as *note
     asctime(): 13ef. and *note localtime(): 1700, require a
     floating-point argument containing the time in seconds since the
     epoch.  The most common use of these functions is to work with the
     current time, so the floating-point argument has been made
     optional; when a value isn’t provided, the current time will be
     used.  For example, log file entries usually need a string
     containing the current time; in Python 2.1, ‘time.asctime()’ can be
     used, instead of the lengthier
     ‘time.asctime(time.localtime(time.time()))’ that was previously
     required.

     This change was proposed and implemented by Thomas Wouters.

   * The *note ftplib: 62. module now defaults to retrieving files in
     passive mode, because passive mode is more likely to work from
     behind a firewall.  This request came from the Debian bug tracking
     system, since other Debian packages use *note ftplib: 62. to
     retrieve files and then don’t work from behind a firewall.  It’s
     deemed unlikely that this will cause problems for anyone, because
     Netscape defaults to passive mode and few people complain, but if
     passive mode is unsuitable for your application or network setup,
     call ‘set_pasv(0)’ on FTP objects to disable passive mode.

   * Support for raw socket access has been added to the *note socket:
     d1. module, contributed by Grant Edwards.

   * The *note pstats: b5. module now contains a simple interactive
     statistics browser for displaying timing profiles for Python
     programs, invoked when the module is run as a script.  Contributed
     by Eric S. Raymond.

   * A new implementation-dependent function, ‘sys._getframe([depth])’,
     has been added to return a given frame object from the current call
     stack.  *note sys._getframe(): 8f1. returns the frame at the top of
     the call stack; if the optional integer argument 'depth' is
     supplied, the function returns the frame that is 'depth' calls
     below the top of the stack.  For example, ‘sys._getframe(1)’
     returns the caller’s frame object.

     This function is only present in CPython, not in Jython or the .NET
     implementation.  Use it for debugging, and resist the temptation to
     put it into production code.


File: python.info,  Node: Other Changes and Fixes<4>,  Next: Acknowledgements<7>,  Prev: New and Improved Modules<4>,  Up: What’s New in Python 2 1

1.22.14 Other Changes and Fixes
-------------------------------

There were relatively few smaller changes made in Python 2.1 due to the
shorter release cycle.  A search through the CVS change logs turns up
117 patches applied, and 136 bugs fixed; both figures are likely to be
underestimates.  Some of the more notable changes are:

   * A specialized object allocator is now optionally available, that
     should be faster than the system ‘malloc()’ and have less memory
     overhead.  The allocator uses C’s ‘malloc()’ function to get large
     pools of memory, and then fulfills smaller memory requests from
     these pools.  It can be enabled by providing the ‘--with-pymalloc’
     option to the ‘configure’ script; see ‘Objects/obmalloc.c’ for the
     implementation details.

     Authors of C extension modules should test their code with the
     object allocator enabled, because some incorrect code may break,
     causing core dumps at runtime.  There are a bunch of memory
     allocation functions in Python’s C API that have previously been
     just aliases for the C library’s ‘malloc()’ and ‘free()’, meaning
     that if you accidentally called mismatched functions, the error
     wouldn’t be noticeable.  When the object allocator is enabled,
     these functions aren’t aliases of ‘malloc()’ and ‘free()’ any more,
     and calling the wrong function to free memory will get you a core
     dump.  For example, if memory was allocated using *note PyMem_New:
     172b, it has to be freed using *note PyMem_Del(): 172c, not
     ‘free()’.  A few modules included with Python fell afoul of this
     and had to be fixed; doubtless there are more third-party modules
     that will have the same problem.

     The object allocator was contributed by Vladimir Marangozov.

   * The speed of line-oriented file I/O has been improved because
     people often complain about its lack of speed, and because it’s
     often been used as a naïve benchmark.  The *note readline(): bf.
     method of file objects has therefore been rewritten to be much
     faster.  The exact amount of the speedup will vary from platform to
     platform depending on how slow the C library’s ‘getc()’ was, but is
     around 66%, and potentially much faster on some particular
     operating systems.  Tim Peters did much of the benchmarking and
     coding for this change, motivated by a discussion in
     comp.lang.python.

     A new module and method for file objects was also added,
     contributed by Jeff Epler.  The new method, ‘xreadlines()’, is
     similar to the existing ‘xrange()’ built-in.  ‘xreadlines()’
     returns an opaque sequence object that only supports being iterated
     over, reading a line on every iteration but not reading the entire
     file into memory as the existing ‘readlines()’ method does.  You’d
     use it like this:

          for line in sys.stdin.xreadlines():
              # ... do something for each line ...
              ...

     For a fuller discussion of the line I/O changes, see the python-dev
     summary for January 1–15, 2001 at
     ‘https://mail.python.org/pipermail/python-dev/2001-January/’.

   * A new method, *note popitem(): 172d, was added to dictionaries to
     enable destructively iterating through the contents of a
     dictionary; this can be faster for large dictionaries because
     there’s no need to construct a list containing all the keys or
     values.  ‘D.popitem()’ removes a random ‘(key, value)’ pair from
     the dictionary ‘D’ and returns it as a 2-tuple.  This was
     implemented mostly by Tim Peters and Guido van Rossum, after a
     suggestion and preliminary patch by Moshe Zadka.

   * Modules can now control which names are imported when ‘from module
     import *’ is used, by defining an ‘__all__’ attribute containing a
     list of names that will be imported.  One common complaint is that
     if the module imports other modules such as *note sys: df. or *note
     string: d8, ‘from module import *’ will add them to the importing
     module’s namespace.  To fix this, simply list the public names in
     ‘__all__’:

          # List public names
          __all__ = ['Database', 'open']

     A stricter version of this patch was first suggested and
     implemented by Ben Wolfson, but after some python-dev discussion, a
     weaker final version was checked in.

   * Applying *note repr(): 1c1. to strings previously used octal
     escapes for non-printable characters; for example, a newline was
     ‘'\012'’.  This was a vestigial trace of Python’s C ancestry, but
     today octal is of very little practical use.  Ka-Ping Yee suggested
     using hex escapes instead of octal ones, and using the ‘\n’, ‘\t’,
     ‘\r’ escapes for the appropriate characters, and implemented this
     new formatting.

   * Syntax errors detected at compile-time can now raise exceptions
     containing the filename and line number of the error, a pleasant
     side effect of the compiler reorganization done by Jeremy Hylton.

   * C extensions which import other modules have been changed to use
     *note PyImport_ImportModule(): 3dc, which means that they will use
     any import hooks that have been installed.  This is also encouraged
     for third-party extensions that need to import some other module
     from C code.

   * The size of the Unicode character database was shrunk by another
     340K thanks to Fredrik Lundh.

   * Some new ports were contributed: MacOS X (by Steven Majewski),
     Cygwin (by Jason Tishler); RISCOS (by Dietmar Schwertberger);
     Unixware 7 (by Billy G. Allie).

And there’s the usual list of minor bugfixes, minor memory leaks,
docstring edits, and other tweaks, too lengthy to be worth itemizing;
see the CVS logs for the full details if you want them.


File: python.info,  Node: Acknowledgements<7>,  Prev: Other Changes and Fixes<4>,  Up: What’s New in Python 2 1

1.22.15 Acknowledgements
------------------------

The author would like to thank the following people for offering
suggestions on various drafts of this article: Graeme Cross, David
Goodger, Jay Graves, Michael Hudson, Marc-André Lemburg, Fredrik Lundh,
Neil Schemenauer, Thomas Wouters.


File: python.info,  Node: What’s New in Python 2 0,  Next: Changelog,  Prev: What’s New in Python 2 1,  Up: Novità in Python

1.23 What’s New in Python 2.0
=============================


Author: A.M. Kuchling and Moshe Zadka

* Menu:

* Introduction: Introduction<3>.
* What About Python 1.6?: What About Python 1 6?.
* New Development Process::
* Unicode: Unicode<2>.
* List Comprehensions::
* Augmented Assignment::
* String Methods::
* Garbage Collection of Cycles::
* Other Core Changes::
* Porting to 2.0: Porting to 2 0.
* Extending/Embedding Changes::
* Distutils; Making Modules Easy to Install: Distutils Making Modules Easy to Install.
* XML Modules::
* Module changes::
* New modules: New modules<2>.
* IDLE Improvements::
* Deleted and Deprecated Modules::
* Acknowledgements: Acknowledgements<8>.


File: python.info,  Node: Introduction<3>,  Next: What About Python 1 6?,  Up: What’s New in Python 2 0

1.23.1 Introduction
-------------------

A new release of Python, version 2.0, was released on October 16, 2000.
This article covers the exciting new features in 2.0, highlights some
other useful changes, and points out a few incompatible changes that may
require rewriting code.

Python’s development never completely stops between releases, and a
steady flow of bug fixes and improvements are always being submitted.  A
host of minor fixes, a few optimizations, additional docstrings, and
better error messages went into 2.0; to list them all would be
impossible, but they’re certainly significant.  Consult the publicly
available CVS logs if you want to see the full list.  This progress is
due to the five developers working for PythonLabs are now getting paid
to spend their days fixing bugs, and also due to the improved
communication resulting from moving to SourceForge.


File: python.info,  Node: What About Python 1 6?,  Next: New Development Process,  Prev: Introduction<3>,  Up: What’s New in Python 2 0

1.23.2 What About Python 1.6?
-----------------------------

Python 1.6 can be thought of as the Contractual Obligations Python
release.  After the core development team left CNRI in May 2000, CNRI
requested that a 1.6 release be created, containing all the work on
Python that had been performed at CNRI. Python 1.6 therefore represents
the state of the CVS tree as of May 2000, with the most significant new
feature being Unicode support.  Development continued after May, of
course, so the 1.6 tree received a few fixes to ensure that it’s
forward-compatible with Python 2.0.  1.6 is therefore part of Python’s
evolution, and not a side branch.

So, should you take much interest in Python 1.6?  Probably not.  The
1.6final and 2.0beta1 releases were made on the same day (September 5,
2000), the plan being to finalize Python 2.0 within a month or so.  If
you have applications to maintain, there seems little point in breaking
things by moving to 1.6, fixing them, and then having another round of
breakage within a month by moving to 2.0; you’re better off just going
straight to 2.0.  Most of the really interesting features described in
this document are only in 2.0, because a lot of work was done between
May and September.


File: python.info,  Node: New Development Process,  Next: Unicode<2>,  Prev: What About Python 1 6?,  Up: What’s New in Python 2 0

1.23.3 New Development Process
------------------------------

The most important change in Python 2.0 may not be to the code at all,
but to how Python is developed: in May 2000 the Python developers began
using the tools made available by SourceForge for storing source code,
tracking bug reports, and managing the queue of patch submissions.  To
report bugs or submit patches for Python 2.0, use the bug tracking and
patch manager tools available from Python’s project page, located at
‘https://sourceforge.net/projects/python/’.

The most important of the services now hosted at SourceForge is the
Python CVS tree, the version-controlled repository containing the source
code for Python.  Previously, there were roughly 7 or so people who had
write access to the CVS tree, and all patches had to be inspected and
checked in by one of the people on this short list.  Obviously, this
wasn’t very scalable.  By moving the CVS tree to SourceForge, it became
possible to grant write access to more people; as of September 2000
there were 27 people able to check in changes, a fourfold increase.
This makes possible large-scale changes that wouldn’t be attempted if
they’d have to be filtered through the small group of core developers.
For example, one day Peter Schneider-Kamp took it into his head to drop
K&R C compatibility and convert the C source for Python to ANSI C. After
getting approval on the python-dev mailing list, he launched into a
flurry of checkins that lasted about a week, other developers joined in
to help, and the job was done.  If there were only 5 people with write
access, probably that task would have been viewed as «nice, but not
worth the time and effort needed» and it would never have gotten done.

The shift to using SourceForge’s services has resulted in a remarkable
increase in the speed of development.  Patches now get submitted,
commented on, revised by people other than the original submitter, and
bounced back and forth between people until the patch is deemed worth
checking in.  Bugs are tracked in one central location and can be
assigned to a specific person for fixing, and we can count the number of
open bugs to measure progress.  This didn’t come without a cost:
developers now have more e-mail to deal with, more mailing lists to
follow, and special tools had to be written for the new environment.
For example, SourceForge sends default patch and bug notification e-mail
messages that are completely unhelpful, so Ka-Ping Yee wrote an HTML
screen-scraper that sends more useful messages.

The ease of adding code caused a few initial growing pains, such as code
was checked in before it was ready or without getting clear agreement
from the developer group.  The approval process that has emerged is
somewhat similar to that used by the Apache group.  Developers can vote
+1, +0, -0, or -1 on a patch; +1 and -1 denote acceptance or rejection,
while +0 and -0 mean the developer is mostly indifferent to the change,
though with a slight positive or negative slant.  The most significant
change from the Apache model is that the voting is essentially advisory,
letting Guido van Rossum, who has Benevolent Dictator For Life status,
know what the general opinion is.  He can still ignore the result of a
vote, and approve or reject a change even if the community disagrees
with him.

Producing an actual patch is the last step in adding a new feature, and
is usually easy compared to the earlier task of coming up with a good
design.  Discussions of new features can often explode into lengthy
mailing list threads, making the discussion hard to follow, and no one
can read every posting to python-dev.  Therefore, a relatively formal
process has been set up to write Python Enhancement Proposals (PEPs),
modelled on the internet RFC process.  PEPs are draft documents that
describe a proposed new feature, and are continually revised until the
community reaches a consensus, either accepting or rejecting the
proposal.  Quoting from the introduction to PEP 1(1), «PEP Purpose and
Guidelines»:

     PEP stands for Python Enhancement Proposal.  A PEP is a design
     document providing information to the Python community, or
     describing a new feature for Python.  The PEP should provide a
     concise technical specification of the feature and a rationale for
     the feature.

     We intend PEPs to be the primary mechanisms for proposing new
     features, for collecting community input on an issue, and for
     documenting the design decisions that have gone into Python.  The
     PEP author is responsible for building consensus within the
     community and documenting dissenting opinions.

Read the rest of PEP 1(2) for the details of the PEP editorial process,
style, and format.  PEPs are kept in the Python CVS tree on SourceForge,
though they’re not part of the Python 2.0 distribution, and are also
available in HTML form from ‘https://peps.python.org/’.  As of September
2000, there are 25 PEPs, ranging from PEP 201(3), «Lockstep Iteration»,
to PEP 225, «Elementwise/Objectwise Operators».

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0001/

   (2) https://peps.python.org/pep-0001/

   (3) https://peps.python.org/pep-0201/


File: python.info,  Node: Unicode<2>,  Next: List Comprehensions,  Prev: New Development Process,  Up: What’s New in Python 2 0

1.23.4 Unicode
--------------

The largest new feature in Python 2.0 is a new fundamental data type:
Unicode strings.  Unicode uses 16-bit numbers to represent characters
instead of the 8-bit number used by ASCII, meaning that 65,536 distinct
characters can be supported.

The final interface for Unicode support was arrived at through countless
often-stormy discussions on the python-dev mailing list, and mostly
implemented by Marc-André Lemburg, based on a Unicode string type
implementation by Fredrik Lundh.  A detailed explanation of the
interface was written up as PEP 100(1), «Python Unicode Integration».
This article will simply cover the most significant points about the
Unicode interfaces.

In Python source code, Unicode strings are written as ‘u"string"’.
Arbitrary Unicode characters can be written using a new escape sequence,
‘\uHHHH’, where 'HHHH' is a 4-digit hexadecimal number from 0000 to
FFFF.  The existing ‘\xHH’ escape sequence can also be used, and octal
escapes can be used for characters up to U+01FF, which is represented by
‘\777’.

Unicode strings, just like regular strings, are an immutable sequence
type.  They can be indexed and sliced, but not modified in place.
Unicode strings have an ‘encode( [encoding] )’ method that returns an
8-bit string in the desired encoding.  Encodings are named by strings,
such as ‘'ascii'’, ‘'utf-8'’, ‘'iso-8859-1'’, or whatever.  A codec API
is defined for implementing and registering new encodings that are then
available throughout a Python program.  If an encoding isn’t specified,
the default encoding is usually 7-bit ASCII, though it can be changed
for your Python installation by calling the
‘sys.setdefaultencoding(encoding)’ function in a customized version of
‘site.py’.

Combining 8-bit and Unicode strings always coerces to Unicode, using the
default ASCII encoding; the result of ‘'a' + u'bc'’ is ‘u'abc'’.

New built-in functions have been added, and existing built-ins modified
to support Unicode:

   * ‘unichr(ch)’ returns a Unicode string 1 character long, containing
     the character 'ch'.

   * ‘ord(u)’, where 'u' is a 1-character regular or Unicode string,
     returns the number of the character as an integer.

   * ‘unicode(string [, encoding] [, errors] )’ creates a Unicode string
     from an 8-bit string.  ‘encoding’ is a string naming the encoding
     to use.  The ‘errors’ parameter specifies the treatment of
     characters that are invalid for the current encoding; passing
     ‘'strict'’ as the value causes an exception to be raised on any
     encoding error, while ‘'ignore'’ causes errors to be silently
     ignored and ‘'replace'’ uses U+FFFD, the official replacement
     character, in case of any problems.

   * The ‘exec’ statement, and various built-ins such as ‘eval()’,
     ‘getattr()’, and ‘setattr()’ will also accept Unicode strings as
     well as regular strings.  (It’s possible that the process of fixing
     this missed some built-ins; if you find a built-in function that
     accepts strings but doesn’t accept Unicode strings at all, please
     report it as a bug.)

A new module, *note unicodedata: 10b, provides an interface to Unicode
character properties.  For example, ‘unicodedata.category(u'A')’ returns
the 2-character string “Lu”, the “L” denoting it’s a letter, and “u”
meaning that it’s uppercase.  ‘unicodedata.bidirectional(u'\u0660')’
returns “AN”, meaning that U+0660 is an Arabic number.

The *note codecs: 1c. module contains functions to look up existing
encodings and register new ones.  Unless you want to implement a new
encoding, you’ll most often use the ‘codecs.lookup(encoding)’ function,
which returns a 4-element tuple: ‘(encode_func, decode_func,
stream_reader, stream_writer)’.

   * 'encode_func' is a function that takes a Unicode string, and
     returns a 2-tuple ‘(string, length)’.  'string' is an 8-bit string
     containing a portion (perhaps all) of the Unicode string converted
     into the given encoding, and 'length' tells you how much of the
     Unicode string was converted.

   * 'decode_func' is the opposite of 'encode_func', taking an 8-bit
     string and returning a 2-tuple ‘(ustring, length)’, consisting of
     the resulting Unicode string 'ustring' and the integer 'length'
     telling how much of the 8-bit string was consumed.

   * 'stream_reader' is a class that supports decoding input from a
     stream.  'stream_reader(file_obj)' returns an object that supports
     the ‘read()’, ‘readline()’, and ‘readlines()’ methods.  These
     methods will all translate from the given encoding and return
     Unicode strings.

   * 'stream_writer', similarly, is a class that supports encoding
     output to a stream.  'stream_writer(file_obj)' returns an object
     that supports the ‘write()’ and ‘writelines()’ methods.  These
     methods expect Unicode strings, translating them to the given
     encoding on output.

For example, the following code writes a Unicode string into a file,
encoding it as UTF-8:

     import codecs

     unistr = u'\u0660\u2000ab ...'

     (UTF8_encode, UTF8_decode,
      UTF8_streamreader, UTF8_streamwriter) = codecs.lookup('UTF-8')

     output = UTF8_streamwriter( open( '/tmp/output', 'wb') )
     output.write( unistr )
     output.close()

The following code would then read UTF-8 input from the file:

     input = UTF8_streamreader( open( '/tmp/output', 'rb') )
     print repr(input.read())
     input.close()

Unicode-aware regular expressions are available through the *note re:
be. module, which has a new underlying implementation called SRE written
by Fredrik Lundh of Secret Labs AB.

A ‘-U’ command line option was added which causes the Python compiler to
interpret all string literals as Unicode string literals.  This is
intended to be used in testing and future-proofing your Python code,
since some future version of Python may drop support for 8-bit strings
and provide only Unicode strings.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0100/


File: python.info,  Node: List Comprehensions,  Next: Augmented Assignment,  Prev: Unicode<2>,  Up: What’s New in Python 2 0

1.23.5 List Comprehensions
--------------------------

Lists are a workhorse data type in Python, and many programs manipulate
a list at some point.  Two common operations on lists are to loop over
them, and either pick out the elements that meet a certain criterion, or
apply some function to each element.  For example, given a list of
strings, you might want to pull out all the strings containing a given
substring, or strip off trailing whitespace from each line.

The existing *note map(): 19f. and *note filter(): a66. functions can be
used for this purpose, but they require a function as one of their
arguments.  This is fine if there’s an existing built-in function that
can be passed directly, but if there isn’t, you have to create a little
function to do the required work, and Python’s scoping rules make the
result ugly if the little function needs additional information.  Take
the first example in the previous paragraph, finding all the strings in
the list containing a given substring.  You could write the following to
do it:

     # Given the list L, make a list of all strings
     # containing the substring S.
     sublist = filter( lambda s, substring=S:
                          string.find(s, substring) != -1,
                       L)

Because of Python’s scoping rules, a default argument is used so that
the anonymous function created by the *note lambda: 14a5. expression
knows what substring is being searched for.  List comprehensions make
this cleaner:

     sublist = [ s for s in L if string.find(s, S) != -1 ]

List comprehensions have the form:

     [ expression for expr in sequence1
                  for expr2 in sequence2 ...
                  for exprN in sequenceN
                  if condition ]

The ‘for’…‘in’ clauses contain the sequences to be iterated over.  The
sequences do not have to be the same length, because they are 'not'
iterated over in parallel, but from left to right; this is explained
more clearly in the following paragraphs.  The elements of the generated
list will be the successive values of 'expression'.  The final ‘if’
clause is optional; if present, 'expression' is only evaluated and added
to the result if 'condition' is true.

To make the semantics very clear, a list comprehension is equivalent to
the following Python code:

     for expr1 in sequence1:
         for expr2 in sequence2:
         ...
             for exprN in sequenceN:
                  if (condition):
                       # Append the value of
                       # the expression to the
                       # resulting list.

This means that when there are multiple ‘for’…‘in’ clauses, the
resulting list will be equal to the product of the lengths of all the
sequences.  If you have two lists of length 3, the output list is 9
elements long:

     seq1 = 'abc'
     seq2 = (1,2,3)
     >>> [ (x,y) for x in seq1 for y in seq2]
     [('a', 1), ('a', 2), ('a', 3), ('b', 1), ('b', 2), ('b', 3), ('c', 1),
     ('c', 2), ('c', 3)]

To avoid introducing an ambiguity into Python’s grammar, if 'expression'
is creating a tuple, it must be surrounded with parentheses.  The first
list comprehension below is a syntax error, while the second one is
correct:

     # Syntax error
     [ x,y for x in seq1 for y in seq2]
     # Correct
     [ (x,y) for x in seq1 for y in seq2]

The idea of list comprehensions originally comes from the functional
programming language Haskell (‘https://www.haskell.org’).  Greg Ewing
argued most effectively for adding them to Python and wrote the initial
list comprehension patch, which was then discussed for a seemingly
endless time on the python-dev mailing list and kept up-to-date by Skip
Montanaro.


File: python.info,  Node: Augmented Assignment,  Next: String Methods,  Prev: List Comprehensions,  Up: What’s New in Python 2 0

1.23.6 Augmented Assignment
---------------------------

Augmented assignment operators, another long-requested feature, have
been added to Python 2.0.  Augmented assignment operators include ‘+=’,
‘-=’, ‘*=’, and so forth.  For example, the statement ‘a += 2’
increments the value of the variable ‘a’ by 2, equivalent to the
slightly lengthier ‘a = a + 2’.

The full list of supported assignment operators is ‘+=’, ‘-=’, ‘*=’,
‘/=’, ‘%=’, ‘**=’, ‘&=’, ‘|=’, ‘^=’, ‘>>=’, and ‘<<=’.  Python classes
can override the augmented assignment operators by defining methods
named ‘__iadd__()’, ‘__isub__()’, etc.  For example, the following
‘Number’ class stores a number and supports using += to create a new
instance with an incremented value.

     class Number:
         def __init__(self, value):
             self.value = value
         def __iadd__(self, increment):
             return Number( self.value + increment)

     n = Number(5)
     n += 3
     print n.value

The ‘__iadd__()’ special method is called with the value of the
increment, and should return a new instance with an appropriately
modified value; this return value is bound as the new value of the
variable on the left-hand side.

Augmented assignment operators were first introduced in the C
programming language, and most C-derived languages, such as ‘awk’, C++,
Java, Perl, and PHP also support them.  The augmented assignment patch
was implemented by Thomas Wouters.


File: python.info,  Node: String Methods,  Next: Garbage Collection of Cycles,  Prev: Augmented Assignment,  Up: What’s New in Python 2 0

1.23.7 String Methods
---------------------

Until now string-manipulation functionality was in the *note string: d8.
module, which was usually a front-end for the ‘strop’ module written in
C. The addition of Unicode posed a difficulty for the ‘strop’ module,
because the functions would all need to be rewritten in order to accept
either 8-bit or Unicode strings.  For functions such as
‘string.replace()’, which takes 3 string arguments, that means eight
possible permutations, and correspondingly complicated code.

Instead, Python 2.0 pushes the problem onto the string type, making
string manipulation functionality available through methods on both
8-bit strings and Unicode strings.

     >>> 'andrew'.capitalize()
     'Andrew'
     >>> 'hostname'.replace('os', 'linux')
     'hlinuxtname'
     >>> 'moshe'.find('sh')
     2

One thing that hasn’t changed, a noteworthy April Fools” joke
notwithstanding, is that Python strings are immutable.  Thus, the string
methods return new strings, and do not modify the string on which they
operate.

The old *note string: d8. module is still around for backwards
compatibility, but it mostly acts as a front-end to the new string
methods.

Two methods which have no parallel in pre-2.0 versions, although they
did exist in JPython for quite some time, are ‘startswith()’ and
‘endswith()’.  ‘s.startswith(t)’ is equivalent to ‘s[:len(t)] == t’,
while ‘s.endswith(t)’ is equivalent to ‘s[-len(t):] == t’.

One other method which deserves special mention is ‘join()’.  The
‘join()’ method of a string receives one parameter, a sequence of
strings, and is equivalent to the ‘string.join()’ function from the old
*note string: d8. module, with the arguments reversed.  In other words,
‘s.join(seq)’ is equivalent to the old ‘string.join(seq, s)’.


File: python.info,  Node: Garbage Collection of Cycles,  Next: Other Core Changes,  Prev: String Methods,  Up: What’s New in Python 2 0

1.23.8 Garbage Collection of Cycles
-----------------------------------

The C implementation of Python uses reference counting to implement
garbage collection.  Every Python object maintains a count of the number
of references pointing to itself, and adjusts the count as references
are created or destroyed.  Once the reference count reaches zero, the
object is no longer accessible, since you need to have a reference to an
object to access it, and if the count is zero, no references exist any
longer.

Reference counting has some pleasant properties: it’s easy to understand
and implement, and the resulting implementation is portable, fairly
fast, and reacts well with other libraries that implement their own
memory handling schemes.  The major problem with reference counting is
that it sometimes doesn’t realise that objects are no longer accessible,
resulting in a memory leak.  This happens when there are cycles of
references.

Consider the simplest possible cycle, a class instance which has a
reference to itself:

     instance = SomeClass()
     instance.myself = instance

After the above two lines of code have been executed, the reference
count of ‘instance’ is 2; one reference is from the variable named
‘'instance'’, and the other is from the ‘myself’ attribute of the
instance.

If the next line of code is ‘del instance’, what happens?  The reference
count of ‘instance’ is decreased by 1, so it has a reference count of 1;
the reference in the ‘myself’ attribute still exists.  Yet the instance
is no longer accessible through Python code, and it could be deleted.
Several objects can participate in a cycle if they have references to
each other, causing all of the objects to be leaked.

Python 2.0 fixes this problem by periodically executing a cycle
detection algorithm which looks for inaccessible cycles and deletes the
objects involved.  A new *note gc: 64. module provides functions to
perform a garbage collection, obtain debugging statistics, and tuning
the collector’s parameters.

Running the cycle detection algorithm takes some time, and therefore
will result in some additional overhead.  It is hoped that after we’ve
gotten experience with the cycle collection from using 2.0, Python 2.1
will be able to minimize the overhead with careful tuning.  It’s not yet
obvious how much performance is lost, because benchmarking this is
tricky and depends crucially on how often the program creates and
destroys objects.  The detection of cycles can be disabled when Python
is compiled, if you can’t afford even a tiny speed penalty or suspect
that the cycle collection is buggy, by specifying the
‘--without-cycle-gc’ switch when running the ‘configure’ script.

Several people tackled this problem and contributed to a solution.  An
early implementation of the cycle detection approach was written by Toby
Kelsey.  The current algorithm was suggested by Eric Tiedemann during a
visit to CNRI, and Guido van Rossum and Neil Schemenauer wrote two
different implementations, which were later integrated by Neil.  Lots of
other people offered suggestions along the way; the March 2000 archives
of the python-dev mailing list contain most of the relevant discussion,
especially in the threads titled «Reference cycle collection for Python»
and «Finalization again».


File: python.info,  Node: Other Core Changes,  Next: Porting to 2 0,  Prev: Garbage Collection of Cycles,  Up: What’s New in Python 2 0

1.23.9 Other Core Changes
-------------------------

Various minor changes have been made to Python’s syntax and built-in
functions.  None of the changes are very far-reaching, but they’re handy
conveniences.

* Menu:

* Minor Language Changes::
* Changes to Built-in Functions::


File: python.info,  Node: Minor Language Changes,  Next: Changes to Built-in Functions,  Up: Other Core Changes

1.23.9.1 Minor Language Changes
...............................

A new syntax makes it more convenient to call a given function with a
tuple of arguments and/or a dictionary of keyword arguments.  In Python
1.5 and earlier, you’d use the ‘apply()’ built-in function: ‘apply(f,
args, kw)’ calls the function ‘f()’ with the argument tuple 'args' and
the keyword arguments in the dictionary 'kw'.  ‘apply()’ is the same in
2.0, but thanks to a patch from Greg Ewing, ‘f(*args, **kw)’ is a
shorter and clearer way to achieve the same effect.  This syntax is
symmetrical with the syntax for defining functions:

     def f(*args, **kw):
         # args is a tuple of positional args,
         # kw is a dictionary of keyword args
         ...

The ‘print’ statement can now have its output directed to a file-like
object by following the ‘print’ with ‘>> file’, similar to the
redirection operator in Unix shells.  Previously you’d either have to
use the ‘write()’ method of the file-like object, which lacks the
convenience and simplicity of ‘print’, or you could assign a new value
to ‘sys.stdout’ and then restore the old value.  For sending output to
standard error, it’s much easier to write this:

     print >> sys.stderr, "Warning: action field not supplied"

Modules can now be renamed on importing them, using the syntax ‘import
module as name’ or ‘from module import name as othername’.  The patch
was submitted by Thomas Wouters.

A new format style is available when using the ‘%’ operator; “%r” will
insert the *note repr(): 1c1. of its argument.  This was also added from
symmetry considerations, this time for symmetry with the existing “%s”
format style, which inserts the *note str(): 169. of its argument.  For
example, ‘'%r %s' % ('abc', 'abc')’ returns a string containing ‘'abc'
abc’.

Previously there was no way to implement a class that overrode Python’s
built-in *note in: 34b. operator and implemented a custom version.  ‘obj
in seq’ returns true if 'obj' is present in the sequence 'seq'; Python
computes this by simply trying every index of the sequence until either
'obj' is found or an *note IndexError: 173c. is encountered.  Moshe
Zadka contributed a patch which adds a ‘__contains__()’ magic method for
providing a custom implementation for ‘in’.  Additionally, new built-in
objects written in C can define what ‘in’ means for them via a new slot
in the sequence protocol.

Earlier versions of Python used a recursive algorithm for deleting
objects.  Deeply nested data structures could cause the interpreter to
fill up the C stack and crash; Christian Tismer rewrote the deletion
logic to fix this problem.  On a related note, comparing recursive
objects recursed infinitely and crashed; Jeremy Hylton rewrote the code
to no longer crash, producing a useful result instead.  For example,
after this code:

     a = []
     b = []
     a.append(a)
     b.append(b)

The comparison ‘a==b’ returns true, because the two recursive data
structures are isomorphic.  See the thread «trashcan and PR#7» in the
April 2000 archives of the python-dev mailing list for the discussion
leading up to this implementation, and some useful relevant links.  Note
that comparisons can now also raise exceptions.  In earlier versions of
Python, a comparison operation such as ‘cmp(a,b)’ would always produce
an answer, even if a user-defined ‘__cmp__()’ method encountered an
error, since the resulting exception would simply be silently swallowed.

Work has been done on porting Python to 64-bit Windows on the Itanium
processor, mostly by Trent Mick of ActiveState.  (Confusingly,
‘sys.platform’ is still ‘'win32'’ on Win64 because it seems that for
ease of porting, MS Visual C++ treats code as 32 bit on Itanium.)
PythonWin also supports Windows CE; see the Python CE page at
‘https://pythonce.sourceforge.net/’ for more information.

Another new platform is Darwin/MacOS X; initial support for it is in
Python 2.0.  Dynamic loading works, if you specify «configure –with-dyld
–with-suffix=.x».  Consult the README in the Python source distribution
for more instructions.

An attempt has been made to alleviate one of Python’s warts, the
often-confusing *note NameError: 452. exception when code refers to a
local variable before the variable has been assigned a value.  For
example, the following code raises an exception on the ‘print’ statement
in both 1.5.2 and 2.0; in 1.5.2 a *note NameError: 452. exception is
raised, while 2.0 raises a new *note UnboundLocalError: 173d. exception.
*note UnboundLocalError: 173d. is a subclass of *note NameError: 452, so
any existing code that expects *note NameError: 452. to be raised should
still work.

     def f():
         print "i=",i
         i = i + 1
     f()

Two new exceptions, *note TabError: 766. and *note IndentationError:
9ad, have been introduced.  They’re both subclasses of *note
SyntaxError: 18e, and are raised when Python code is found to be
improperly indented.


File: python.info,  Node: Changes to Built-in Functions,  Prev: Minor Language Changes,  Up: Other Core Changes

1.23.9.2 Changes to Built-in Functions
......................................

A new built-in, ‘zip(seq1, seq2, ...)’, has been added.  *note zip():
1a0. returns a list of tuples where each tuple contains the i-th element
from each of the argument sequences.  The difference between *note
zip(): 1a0. and ‘map(None, seq1, seq2)’ is that *note map(): 19f. pads
the sequences with ‘None’ if the sequences aren’t all of the same
length, while *note zip(): 1a0. truncates the returned list to the
length of the shortest argument sequence.

The *note int(): 19b. and ‘long()’ functions now accept an optional
«base» parameter when the first argument is a string.  ‘int('123', 10)’
returns 123, while ‘int('123', 16)’ returns 291.  ‘int(123, 16)’ raises
a *note TypeError: 198. exception with the message «can’t convert
non-string with explicit base».

A new variable holding more detailed version information has been added
to the *note sys: df. module.  ‘sys.version_info’ is a tuple ‘(major,
minor, micro, level, serial)’ For example, in a hypothetical 2.0.1beta1,
‘sys.version_info’ would be ‘(2, 0, 1, 'beta', 1)’.  'level' is a string
such as ‘"alpha"’, ‘"beta"’, or ‘"final"’ for a final release.

Dictionaries have an odd new method, ‘setdefault(key, default)’, which
behaves similarly to the existing ‘get()’ method.  However, if the key
is missing, ‘setdefault()’ both returns the value of 'default' as
‘get()’ would do, and also inserts it into the dictionary as the value
for 'key'.  Thus, the following lines of code:

     if dict.has_key( key ): return dict[key]
     else:
         dict[key] = []
         return dict[key]

can be reduced to a single ‘return dict.setdefault(key, [])’ statement.

The interpreter sets a maximum recursion depth in order to catch runaway
recursion before filling the C stack and causing a core dump or GPF..
Previously this limit was fixed when you compiled Python, but in 2.0 the
maximum recursion depth can be read and modified using *note
sys.getrecursionlimit(): 6ec. and *note sys.setrecursionlimit(): 6eb.
The default value is 1000, and a rough maximum value for a given
platform can be found by running a new script,
‘Misc/find_recursionlimit.py’.


File: python.info,  Node: Porting to 2 0,  Next: Extending/Embedding Changes,  Prev: Other Core Changes,  Up: What’s New in Python 2 0

1.23.10 Porting to 2.0
----------------------

New Python releases try hard to be compatible with previous releases,
and the record has been pretty good.  However, some changes are
considered useful enough, usually because they fix initial design
decisions that turned out to be actively mistaken, that breaking
backward compatibility can’t always be avoided.  This section lists the
changes in Python 2.0 that may cause old Python code to break.

The change which will probably break the most code is tightening up the
arguments accepted by some methods.  Some methods would take multiple
arguments and treat them as a tuple, particularly various list methods
such as *note append(): 8dd. and *note insert(): 13a0.  In earlier
versions of Python, if ‘L’ is a list, ‘L.append( 1,2 )’ appends the
tuple ‘(1,2)’ to the list.  In Python 2.0 this causes a *note TypeError:
198. exception to be raised, with the message: “append requires exactly
1 argument; 2 given”.  The fix is to simply add an extra set of
parentheses to pass both values as a tuple: ‘L.append( (1,2) )’.

The earlier versions of these methods were more forgiving because they
used an old function in Python’s C interface to parse their arguments;
2.0 modernizes them to use *note PyArg_ParseTuple(): 3c1, the current
argument parsing function, which provides more helpful error messages
and treats multi-argument calls as errors.  If you absolutely must use
2.0 but can’t fix your code, you can edit ‘Objects/listobject.c’ and
define the preprocessor symbol ‘NO_STRICT_LIST_APPEND’ to preserve the
old behaviour; this isn’t recommended.

Some of the functions in the *note socket: d1. module are still
forgiving in this way.  For example, ‘socket.connect( ('hostname', 25)
)’ is the correct form, passing a tuple representing an IP address, but
‘socket.connect('hostname', 25)’ also works.  *note socket.connect_ex:
1740. and *note socket.bind: 1741. are similarly easy-going.  2.0alpha1
tightened these functions up, but because the documentation actually
used the erroneous multiple argument form, many people wrote code which
would break with the stricter checking.  GvR backed out the changes in
the face of public reaction, so for the *note socket: d1. module, the
documentation was fixed and the multiple argument form is simply marked
as deprecated; it 'will' be tightened up again in a future Python
version.

The ‘\x’ escape in string literals now takes exactly 2 hex digits.
Previously it would consume all the hex digits following the “x” and
take the lowest 8 bits of the result, so ‘\x123456’ was equivalent to
‘\x56’.

The *note AttributeError: 5f0. and *note NameError: 452. exceptions have
a more friendly error message, whose text will be something like ‘'Spam'
instance has no attribute 'eggs'’ or ‘name 'eggs' is not defined’.
Previously the error message was just the missing attribute name ‘eggs’,
and code written to take advantage of this fact will break in 2.0.

Some work has been done to make integers and long integers a bit more
interchangeable.  In 1.5.2, large-file support was added for Solaris, to
allow reading files larger than 2 GiB; this made the ‘tell()’ method of
file objects return a long integer instead of a regular integer.  Some
code would subtract two file offsets and attempt to use the result to
multiply a sequence or slice a string, but this raised a *note
TypeError: 198.  In 2.0, long integers can be used to multiply or slice
a sequence, and it’ll behave as you’d intuitively expect it to; ‘3L *
'abc'’ produces “abcabcabc”, and ‘(0,1,2,3)[2L:4L]’ produces (2,3).
Long integers can also be used in various contexts where previously only
integers were accepted, such as in the ‘seek()’ method of file objects,
and in the formats supported by the ‘%’ operator (‘%d’, ‘%i’, ‘%x’,
etc.).  For example, ‘"%d" % 2L**64’ will produce the string
‘18446744073709551616’.

The subtlest long integer change of all is that the *note str(): 169. of
a long integer no longer has a trailing “L” character, though *note
repr(): 1c1. still includes it.  The “L” annoyed many people who wanted
to print long integers that looked just like regular integers, since
they had to go out of their way to chop off the character.  This is no
longer a problem in 2.0, but code which does ‘str(longval)[:-1]’ and
assumes the “L” is there, will now lose the final digit.

Taking the *note repr(): 1c1. of a float now uses a different formatting
precision than *note str(): 169.  *note repr(): 1c1. uses ‘%.17g’ format
string for C’s ‘sprintf()’, while *note str(): 169. uses ‘%.12g’ as
before.  The effect is that *note repr(): 1c1. may occasionally show
more decimal places than *note str(): 169, for certain numbers.  For
example, the number 8.1 can’t be represented exactly in binary, so
‘repr(8.1)’ is ‘'8.0999999999999996'’, while str(8.1) is ‘'8.1'’.

The ‘-X’ command-line option, which turned all standard exceptions into
strings instead of classes, has been removed; the standard exceptions
will now always be classes.  The ‘exceptions’ module containing the
standard exceptions was translated from Python to a built-in C module,
written by Barry Warsaw and Fredrik Lundh.


File: python.info,  Node: Extending/Embedding Changes,  Next: Distutils Making Modules Easy to Install,  Prev: Porting to 2 0,  Up: What’s New in Python 2 0

1.23.11 Extending/Embedding Changes
-----------------------------------

Some of the changes are under the covers, and will only be apparent to
people writing C extension modules or embedding a Python interpreter in
a larger application.  If you aren’t dealing with Python’s C API, you
can safely skip this section.

The version number of the Python C API was incremented, so C extensions
compiled for 1.5.2 must be recompiled in order to work with 2.0.  On
Windows, it’s not possible for Python 2.0 to import a third party
extension built for Python 1.5.x due to how Windows DLLs work, so Python
will raise an exception and the import will fail.

Users of Jim Fulton’s ExtensionClass module will be pleased to find out
that hooks have been added so that ExtensionClasses are now supported by
*note isinstance(): 2ad. and *note issubclass(): 9c6.  This means you no
longer have to remember to write code such as ‘if type(obj) ==
myExtensionClass’, but can use the more natural ‘if isinstance(obj,
myExtensionClass)’.

The ‘Python/importdl.c’ file, which was a mass of #ifdefs to support
dynamic loading on many different platforms, was cleaned up and
reorganised by Greg Stein.  ‘importdl.c’ is now quite small, and
platform-specific code has been moved into a bunch of
‘Python/dynload_*.c’ files.  Another cleanup: there were also a number
of ‘my*.h’ files in the Include/ directory that held various portability
hacks; they’ve been merged into a single file, ‘Include/pyport.h’.

Vladimir Marangozov’s long-awaited malloc restructuring was completed,
to make it easy to have the Python interpreter use a custom allocator
instead of C’s standard ‘malloc()’.  For documentation, read the
comments in ‘Include/pymem.h’ and ‘Include/objimpl.h’.  For the lengthy
discussions during which the interface was hammered out, see the web
archives of the “patches” and “python-dev” lists at python.org.

Recent versions of the GUSI development environment for MacOS support
POSIX threads.  Therefore, Python’s POSIX threading support now works on
the Macintosh.  Threading support using the user-space GNU ‘pth’ library
was also contributed.

Threading support on Windows was enhanced, too.  Windows supports thread
locks that use kernel objects only in case of contention; in the common
case when there’s no contention, they use simpler functions which are an
order of magnitude faster.  A threaded version of Python 1.5.2 on NT is
twice as slow as an unthreaded version; with the 2.0 changes, the
difference is only 10%.  These improvements were contributed by Yakov
Markovitch.

Python 2.0’s source now uses only ANSI C prototypes, so compiling Python
now requires an ANSI C compiler, and can no longer be done using a
compiler that only supports K&R C.

Previously the Python virtual machine used 16-bit numbers in its
bytecode, limiting the size of source files.  In particular, this
affected the maximum size of literal lists and dictionaries in Python
source; occasionally people who are generating Python code would run
into this limit.  A patch by Charles G. Waldman raises the limit from
‘2**16’ to ‘2**32’.

Three new convenience functions intended for adding constants to a
module’s dictionary at module initialization time were added: *note
PyModule_AddObject(): 60b, *note PyModule_AddIntConstant(): 1743, and
*note PyModule_AddStringConstant(): 1744.  Each of these functions takes
a module object, a null-terminated C string containing the name to be
added, and a third argument for the value to be assigned to the name.
This third argument is, respectively, a Python object, a C long, or a C
string.

A wrapper API was added for Unix-style signal handlers.  *note
PyOS_getsig(): 1745. gets a signal handler and *note PyOS_setsig():
1746. will set a new handler.


File: python.info,  Node: Distutils Making Modules Easy to Install,  Next: XML Modules,  Prev: Extending/Embedding Changes,  Up: What’s New in Python 2 0

1.23.12 Distutils: Making Modules Easy to Install
-------------------------------------------------

Before Python 2.0, installing modules was a tedious affair – there was
no way to figure out automatically where Python is installed, or what
compiler options to use for extension modules.  Software authors had to
go through an arduous ritual of editing Makefiles and configuration
files, which only really work on Unix and leave Windows and MacOS
unsupported.  Python users faced wildly differing installation
instructions which varied between different extension packages, which
made administering a Python installation something of a chore.

The SIG for distribution utilities, shepherded by Greg Ward, has created
the Distutils, a system to make package installation much easier.  They
form the ‘distutils’ package, a new part of Python’s standard library.
In the best case, installing a Python module from source will require
the same steps: first you simply mean unpack the tarball or zip archive,
and the run «‘python setup.py install’».  The platform will be
automatically detected, the compiler will be recognized, C extension
modules will be compiled, and the distribution installed into the proper
directory.  Optional command-line arguments provide more control over
the installation process, the distutils package offers many places to
override defaults – separating the build from the install, building or
installing in non-default directories, and more.

In order to use the Distutils, you need to write a ‘setup.py’ script.
For the simple case, when the software contains only .py files, a
minimal ‘setup.py’ can be just a few lines long:

     from distutils.core import setup
     setup (name = "foo", version = "1.0",
            py_modules = ["module1", "module2"])

The ‘setup.py’ file isn’t much more complicated if the software consists
of a few packages:

     from distutils.core import setup
     setup (name = "foo", version = "1.0",
            packages = ["package", "package.subpackage"])

A C extension can be the most complicated case; here’s an example taken
from the PyXML package:

     from distutils.core import setup, Extension

     expat_extension = Extension('xml.parsers.pyexpat',
          define_macros = [('XML_NS', None)],
          include_dirs = [ 'extensions/expat/xmltok',
                           'extensions/expat/xmlparse' ],
          sources = [ 'extensions/pyexpat.c',
                      'extensions/expat/xmltok/xmltok.c',
                      'extensions/expat/xmltok/xmlrole.c', ]
            )
     setup (name = "PyXML", version = "0.5.4",
            ext_modules =[ expat_extension ] )

The Distutils can also take care of creating source and binary
distributions.  The «sdist» command, run by «‘python setup.py sdist’”,
builds a source distribution such as ‘foo-1.0.tar.gz’.  Adding new
commands isn’t difficult, «bdist_rpm» and «bdist_wininst» commands have
already been contributed to create an RPM distribution and a Windows
installer for the software, respectively.  Commands to create other
distribution formats such as Debian packages and Solaris ‘.pkg’ files
are in various stages of development.

All this is documented in a new manual, 'Distributing Python Modules',
that joins the basic set of Python documentation.


File: python.info,  Node: XML Modules,  Next: Module changes,  Prev: Distutils Making Modules Easy to Install,  Up: What’s New in Python 2 0

1.23.13 XML Modules
-------------------

Python 1.5.2 included a simple XML parser in the form of the ‘xmllib’
module, contributed by Sjoerd Mullender.  Since 1.5.2’s release, two
different interfaces for processing XML have become common: SAX2
(version 2 of the Simple API for XML) provides an event-driven interface
with some similarities to ‘xmllib’, and the DOM (Document Object Model)
provides a tree-based interface, transforming an XML document into a
tree of nodes that can be traversed and modified.  Python 2.0 includes a
SAX2 interface and a stripped-down DOM interface as part of the *note
xml: 126. package.  Here we will give a brief overview of these new
interfaces; consult the Python documentation or the source code for
complete details.  The Python XML SIG is also working on improved
documentation.

* Menu:

* SAX2 Support::
* DOM Support::
* Relationship to PyXML::


File: python.info,  Node: SAX2 Support,  Next: DOM Support,  Up: XML Modules

1.23.13.1 SAX2 Support
......................

SAX defines an event-driven interface for parsing XML. To use SAX, you
must write a SAX handler class.  Handler classes inherit from various
classes provided by SAX, and override various methods that will then be
called by the XML parser.  For example, the *note startElement(): 174a.
and *note endElement(): 174b. methods are called for every starting and
end tag encountered by the parser, the *note characters(): 174c. method
is called for every chunk of character data, and so forth.

The advantage of the event-driven approach is that the whole document
doesn’t have to be resident in memory at any one time, which matters if
you are processing really huge documents.  However, writing the SAX
handler class can get very complicated if you’re trying to modify the
document structure in some elaborate way.

For example, this little example program defines a handler that prints a
message for every starting and ending tag, and then parses the file
‘hamlet.xml’ using it:

     from xml import sax

     class SimpleHandler(sax.ContentHandler):
         def startElement(self, name, attrs):
             print 'Start of element:', name, attrs.keys()

         def endElement(self, name):
             print 'End of element:', name

     # Create a parser object
     parser = sax.make_parser()

     # Tell it what handler to use
     handler = SimpleHandler()
     parser.setContentHandler( handler )

     # Parse a file!
     parser.parse( 'hamlet.xml' )

For more information, consult the Python documentation, or the XML HOWTO
at ‘https://pyxml.sourceforge.net/topics/howto/xml-howto.html’.


File: python.info,  Node: DOM Support,  Next: Relationship to PyXML,  Prev: SAX2 Support,  Up: XML Modules

1.23.13.2 DOM Support
.....................

The Document Object Model is a tree-based representation for an XML
document.  A top-level ‘Document’ instance is the root of the tree, and
has a single child which is the top-level ‘Element’ instance.  This
‘Element’ has children nodes representing character data and any
sub-elements, which may have further children of their own, and so
forth.  Using the DOM you can traverse the resulting tree any way you
like, access element and attribute values, insert and delete nodes, and
convert the tree back into XML.

The DOM is useful for modifying XML documents, because you can create a
DOM tree, modify it by adding new nodes or rearranging subtrees, and
then produce a new XML document as output.  You can also construct a DOM
tree manually and convert it to XML, which can be a more flexible way of
producing XML output than simply writing ‘<tag1>’…‘</tag1>’ to a file.

The DOM implementation included with Python lives in the *note
xml.dom.minidom: 128. module.  It’s a lightweight implementation of the
Level 1 DOM with support for XML namespaces.  The ‘parse()’ and
‘parseString()’ convenience functions are provided for generating a DOM
tree:

     from xml.dom import minidom
     doc = minidom.parse('hamlet.xml')

‘doc’ is a ‘Document’ instance.  ‘Document’, like all the other DOM
classes such as ‘Element’ and ‘Text’, is a subclass of the ‘Node’ base
class.  All the nodes in a DOM tree therefore support certain common
methods, such as ‘toxml()’ which returns a string containing the XML
representation of the node and its children.  Each class also has
special methods of its own; for example, ‘Element’ and ‘Document’
instances have a method to find all child elements with a given tag
name.  Continuing from the previous 2-line example:

     perslist = doc.getElementsByTagName( 'PERSONA' )
     print perslist[0].toxml()
     print perslist[1].toxml()

For the 'Hamlet' XML file, the above few lines output:

     <PERSONA>CLAUDIUS, king of Denmark. </PERSONA>
     <PERSONA>HAMLET, son to the late, and nephew to the present king.</PERSONA>

The root element of the document is available as ‘doc.documentElement’,
and its children can be easily modified by deleting, adding, or removing
nodes:

     root = doc.documentElement

     # Remove the first child
     root.removeChild( root.childNodes[0] )

     # Move the new first child to the end
     root.appendChild( root.childNodes[0] )

     # Insert the new first child (originally,
     # the third child) before the 20th child.
     root.insertBefore( root.childNodes[0], root.childNodes[20] )

Again, I will refer you to the Python documentation for a complete
listing of the different ‘Node’ classes and their various methods.


File: python.info,  Node: Relationship to PyXML,  Prev: DOM Support,  Up: XML Modules

1.23.13.3 Relationship to PyXML
...............................

The XML Special Interest Group has been working on XML-related Python
code for a while.  Its code distribution, called PyXML, is available
from the SIG’s web pages at
‘https://www.python.org/community/sigs/current/xml-sig’.  The PyXML
distribution also used the package name ‘xml’.  If you’ve written
programs that used PyXML, you’re probably wondering about its
compatibility with the 2.0 *note xml: 126. package.

The answer is that Python 2.0’s *note xml: 126. package isn’t compatible
with PyXML, but can be made compatible by installing a recent version
PyXML. Many applications can get by with the XML support that is
included with Python 2.0, but more complicated applications will require
that the full PyXML package will be installed.  When installed, PyXML
versions 0.6.0 or greater will replace the *note xml: 126. package
shipped with Python, and will be a strict superset of the standard
package, adding a bunch of additional features.  Some of the additional
features in PyXML include:

   * 4DOM, a full DOM implementation from FourThought, Inc.

   * The xmlproc validating parser, written by Lars Marius Garshol.

   * The ‘sgmlop’ parser accelerator module, written by Fredrik Lundh.


File: python.info,  Node: Module changes,  Next: New modules<2>,  Prev: XML Modules,  Up: What’s New in Python 2 0

1.23.14 Module changes
----------------------

Lots of improvements and bugfixes were made to Python’s extensive
standard library; some of the affected modules include *note readline:
bf, *note ConfigParser: 26, ‘cgi’, *note calendar: 15, *note posix: b2,
*note readline: bf, ‘xmllib’, ‘aifc’, ‘chunk’, *note wave: 119, *note
random: bd, *note shelve: c8, and ‘nntplib’.  Consult the CVS logs for
the exact patch-by-patch details.

Brian Gallew contributed OpenSSL support for the *note socket: d1.
module.  OpenSSL is an implementation of the Secure Socket Layer, which
encrypts the data being sent over a socket.  When compiling Python, you
can edit ‘Modules/Setup’ to include SSL support, which adds an
additional function to the *note socket: d1. module: ‘socket.ssl(socket,
keyfile, certfile)’, which takes a socket object and returns an SSL
socket.  The *note httplib: 72. and *note urllib: 10e. modules were also
changed to support ‘https://’ URLs, though no one has implemented FTP or
SMTP over SSL.

The *note httplib: 72. module has been rewritten by Greg Stein to
support HTTP/1.1.

Backward compatibility with the 1.5 version of ‘httplib’ is provided,
though using HTTP/1.1 features such as pipelining will require rewriting
code to use a different set of interfaces.

The ‘Tkinter’ module now supports Tcl/Tk version 8.1, 8.2, or 8.3, and
support for the older 7.x versions has been dropped.  The Tkinter module
now supports displaying Unicode strings in Tk widgets.  Also, Fredrik
Lundh contributed an optimization which makes operations like
‘create_line’ and ‘create_polygon’ much faster, especially when using
lots of coordinates.

The *note curses: 2f. module has been greatly extended, starting from
Oliver Andrich’s enhanced version, to provide many additional functions
from ncurses and SYSV curses, such as colour, alternative character set
support, pads, and mouse support.  This means the module is no longer
compatible with operating systems that only have BSD curses, but there
don’t seem to be any currently maintained OSes that fall into this
category.

As mentioned in the earlier discussion of 2.0’s Unicode support, the
underlying implementation of the regular expressions provided by the
*note re: be. module has been changed.  SRE, a new regular expression
engine written by Fredrik Lundh and partially funded by Hewlett Packard,
supports matching against both 8-bit strings and Unicode strings.


File: python.info,  Node: New modules<2>,  Next: IDLE Improvements,  Prev: Module changes,  Up: What’s New in Python 2 0

1.23.15 New modules
-------------------

A number of new modules were added.  We’ll simply list them with brief
descriptions; consult the 2.0 documentation for the details of a
particular module.

   * *note atexit: d.: For registering functions to be called before the
     Python interpreter exits.  Code that currently sets ‘sys.exitfunc’
     directly should be changed to use the *note atexit: d. module
     instead, importing *note atexit: d. and calling *note
     atexit.register(): a80. with the function to be called on exit.
     (Contributed by Skip Montanaro.)

   * *note codecs: 1c, ‘encodings’, *note unicodedata: 10b.: Added as
     part of the new Unicode support.

   * *note filecmp: 5e.: Supersedes the old ‘cmp’, ‘cmpcache’ and
     ‘dircmp’ modules, which have now become deprecated.  (Contributed
     by Gordon MacMillan and Moshe Zadka.)

   * *note gettext: 67.: This module provides internationalization
     (I18N) and localization (L10N) support for Python programs by
     providing an interface to the GNU gettext message catalog library.
     (Integrated by Barry Warsaw, from separate contributions by Martin
     von Löwis, Peter Funk, and James Henstridge.)

   * ‘linuxaudiodev’: Support for the ‘/dev/audio’ device on Linux, a
     twin to the existing ‘sunaudiodev’ module.  (Contributed by Peter
     Bosch, with fixes by Jeremy Hylton.)

   * *note mmap: 94.: An interface to memory-mapped files on both
     Windows and Unix.  A file’s contents can be mapped directly into
     memory, at which point it behaves like a mutable string, so its
     contents can be read and modified.  They can even be passed to
     functions that expect ordinary strings, such as the *note re: be.
     module.  (Contributed by Sam Rushing, with some extensions by A.M.
     Kuchling.)

   * ‘pyexpat’: An interface to the Expat XML parser.  (Contributed by
     Paul Prescod.)

   * *note robotparser: 113.: Parse a ‘robots.txt’ file, which is used
     for writing web spiders that politely avoid certain areas of a web
     site.  The parser accepts the contents of a ‘robots.txt’ file,
     builds a set of rules from it, and can then answer questions about
     the fetchability of a given URL. (Contributed by Skip Montanaro.)

   * *note tabnanny: e3.: A module/script to check Python source code
     for ambiguous indentation.  (Contributed by Tim Peters.)

   * ‘UserString’: A base class useful for deriving objects that behave
     like strings.

   * *note webbrowser: 11b.: A module that provides a platform
     independent way to launch a web browser on a specific URL. For each
     platform, various browsers are tried in a specific order.  The user
     can alter which browser is launched by setting the 'BROWSER'
     environment variable.  (Originally inspired by Eric S. Raymond’s
     patch to *note urllib: 10e. which added similar functionality, but
     the final module comes from code originally implemented by Fred
     Drake as ‘Tools/idle/BrowserControl.py’, and adapted for the
     standard library by Fred.)

   * *note _winreg: 11c.: An interface to the Windows registry.
     ‘_winreg’ is an adaptation of functions that have been part of
     PythonWin since 1995, but has now been added to the core
     distribution, and enhanced to support Unicode.  ‘_winreg’ was
     written by Bill Tutt and Mark Hammond.

   * *note zipfile: 137.: A module for reading and writing ZIP-format
     archives.  These are archives produced by ‘PKZIP’ on DOS/Windows or
     ‘zip’ on Unix, not to be confused with ‘gzip’-format files (which
     are supported by the *note gzip: 6b. module) (Contributed by James
     C. Ahlstrom.)

   * ‘imputil’: A module that provides a simpler way for writing
     customized import hooks, in comparison to the existing ‘ihooks’
     module.  (Implemented by Greg Stein, with much discussion on
     python-dev along the way.)


File: python.info,  Node: IDLE Improvements,  Next: Deleted and Deprecated Modules,  Prev: New modules<2>,  Up: What’s New in Python 2 0

1.23.16 IDLE Improvements
-------------------------

IDLE is the official Python cross-platform IDE, written using Tkinter.
Python 2.0 includes IDLE 0.6, which adds a number of new features and
improvements.  A partial list:

   * UI improvements and optimizations, especially in the area of syntax
     highlighting and auto-indentation.

   * The class browser now shows more information, such as the top level
     functions in a module.

   * Tab width is now a user settable option.  When opening an existing
     Python file, IDLE automatically detects the indentation
     conventions, and adapts.

   * There is now support for calling browsers on various platforms,
     used to open the Python documentation in a browser.

   * IDLE now has a command line, which is largely similar to the
     vanilla Python interpreter.

   * Call tips were added in many places.

   * IDLE can now be installed as a package.

   * In the editor window, there is now a line/column bar at the bottom.

   * Three new keystroke commands: Check module (‘Alt’-‘F5’), Import
     module (‘F5’) and Run script (‘Ctrl’-‘F5’).


File: python.info,  Node: Deleted and Deprecated Modules,  Next: Acknowledgements<8>,  Prev: IDLE Improvements,  Up: What’s New in Python 2 0

1.23.17 Deleted and Deprecated Modules
--------------------------------------

A few modules have been dropped because they’re obsolete, or because
there are now better ways to do the same thing.  The ‘stdwin’ module is
gone; it was for a platform-independent windowing toolkit that’s no
longer developed.

A number of modules have been moved to the ‘lib-old’ subdirectory:
‘cmp’, ‘cmpcache’, ‘dircmp’, ‘dump’, ‘find’, ‘grep’, ‘packmail’, ‘poly’,
‘util’, ‘whatsound’, ‘zmod’.  If you have code which relies on a module
that’s been moved to ‘lib-old’, you can simply add that directory to
‘sys.path’ to get them back, but you’re encouraged to update any code
that uses these modules.


File: python.info,  Node: Acknowledgements<8>,  Prev: Deleted and Deprecated Modules,  Up: What’s New in Python 2 0

1.23.18 Acknowledgements
------------------------

The authors would like to thank the following people for offering
suggestions on various drafts of this article: David Bolen, Mark
Hammond, Gregg Hauser, Jeremy Hylton, Fredrik Lundh, Detlef Lannert,
Aahz Maruch, Skip Montanaro, Vladimir Marangozov, Tobias Polzin, Guido
van Rossum, Neil Schemenauer, and Russ Schmidt.

Il «Changelog» è una versione HTML del file built(1) dai contenuti del
Misc/NEWS.d(2), e contiene 'tutte' le modifiche non banali a Python per
la versione corrente.

   ---------- Footnotes ----------

   (1) https://pypi.org/project/blurb/

   (2) https://github.com/python/cpython/tree/3.14/Misc/NEWS.d


File: python.info,  Node: Changelog,  Prev: What’s New in Python 2 0,  Up: Novità in Python

1.24 Changelog
==============

* Menu:

* Python next::
* Python 3.14.2 final: Python 3 14 2 final.
* Python 3.14.1 final: Python 3 14 1 final.
* Python 3.14.0 final: Python 3 14 0 final.
* Python 3.14.0 release candidate 3: Python 3 14 0 release candidate 3.
* Python 3.14.0 release candidate 2: Python 3 14 0 release candidate 2.
* Python 3.14.0 release candidate 1: Python 3 14 0 release candidate 1.
* Python 3.14.0 beta 4: Python 3 14 0 beta 4.
* Python 3.14.0 beta 3: Python 3 14 0 beta 3.
* Python 3.14.0 beta 2: Python 3 14 0 beta 2.
* Python 3.14.0 beta 1: Python 3 14 0 beta 1.
* Python 3.14.0 alpha 7: Python 3 14 0 alpha 7.
* Python 3.14.0 alpha 6: Python 3 14 0 alpha 6.
* Python 3.14.0 alpha 5: Python 3 14 0 alpha 5.
* Python 3.14.0 alpha 4: Python 3 14 0 alpha 4.
* Python 3.14.0 alpha 3: Python 3 14 0 alpha 3.
* Python 3.14.0 alpha 2: Python 3 14 0 alpha 2.
* Python 3.14.0 alpha 1: Python 3 14 0 alpha 1.
* Python 3.13.0 beta 1: Python 3 13 0 beta 1.
* Python 3.13.0 alpha 6: Python 3 13 0 alpha 6.
* Python 3.13.0 alpha 5: Python 3 13 0 alpha 5.
* Python 3.13.0 alpha 4: Python 3 13 0 alpha 4.
* Python 3.13.0 alpha 3: Python 3 13 0 alpha 3.
* Python 3.13.0 alpha 2: Python 3 13 0 alpha 2.
* Python 3.13.0 alpha 1: Python 3 13 0 alpha 1.
* Python 3.12.0 beta 1: Python 3 12 0 beta 1.
* Python 3.12.0 alpha 7: Python 3 12 0 alpha 7.
* Python 3.12.0 alpha 6: Python 3 12 0 alpha 6.
* Python 3.12.0 alpha 5: Python 3 12 0 alpha 5.
* Python 3.12.0 alpha 4: Python 3 12 0 alpha 4.
* Python 3.12.0 alpha 3: Python 3 12 0 alpha 3.
* Python 3.12.0 alpha 2: Python 3 12 0 alpha 2.
* Python 3.12.0 alpha 1: Python 3 12 0 alpha 1.
* Python 3.11.0 beta 1: Python 3 11 0 beta 1.
* Python 3.11.0 alpha 7: Python 3 11 0 alpha 7.
* Python 3.11.0 alpha 6: Python 3 11 0 alpha 6.
* Python 3.11.0 alpha 5: Python 3 11 0 alpha 5.
* Python 3.11.0 alpha 4: Python 3 11 0 alpha 4.
* Python 3.11.0 alpha 3: Python 3 11 0 alpha 3.
* Python 3.11.0 alpha 2: Python 3 11 0 alpha 2.
* Python 3.11.0 alpha 1: Python 3 11 0 alpha 1.
* Python 3.10.0 beta 1: Python 3 10 0 beta 1.
* Python 3.10.0 alpha 7: Python 3 10 0 alpha 7.
* Python 3.10.0 alpha 6: Python 3 10 0 alpha 6.
* Python 3.10.0 alpha 5: Python 3 10 0 alpha 5.
* Python 3.10.0 alpha 4: Python 3 10 0 alpha 4.
* Python 3.10.0 alpha 3: Python 3 10 0 alpha 3.
* Python 3.10.0 alpha 2: Python 3 10 0 alpha 2.
* Python 3.10.0 alpha 1: Python 3 10 0 alpha 1.
* Python 3.9.0 beta 1: Python 3 9 0 beta 1.
* Python 3.9.0 alpha 6: Python 3 9 0 alpha 6.
* Python 3.9.0 alpha 5: Python 3 9 0 alpha 5.
* Python 3.9.0 alpha 4: Python 3 9 0 alpha 4.
* Python 3.9.0 alpha 3: Python 3 9 0 alpha 3.
* Python 3.9.0 alpha 2: Python 3 9 0 alpha 2.
* Python 3.9.0 alpha 1: Python 3 9 0 alpha 1.
* Python 3.8.0 beta 1: Python 3 8 0 beta 1.
* Python 3.8.0 alpha 4: Python 3 8 0 alpha 4.
* Python 3.8.0 alpha 3: Python 3 8 0 alpha 3.
* Python 3.8.0 alpha 2: Python 3 8 0 alpha 2.
* Python 3.8.0 alpha 1: Python 3 8 0 alpha 1.
* Python 3.7.0 final: Python 3 7 0 final.
* Python 3.7.0 release candidate 1: Python 3 7 0 release candidate 1.
* Python 3.7.0 beta 5: Python 3 7 0 beta 5.
* Python 3.7.0 beta 4: Python 3 7 0 beta 4.
* Python 3.7.0 beta 3: Python 3 7 0 beta 3.
* Python 3.7.0 beta 2: Python 3 7 0 beta 2.
* Python 3.7.0 beta 1: Python 3 7 0 beta 1.
* Python 3.7.0 alpha 4: Python 3 7 0 alpha 4.
* Python 3.7.0 alpha 3: Python 3 7 0 alpha 3.
* Python 3.7.0 alpha 2: Python 3 7 0 alpha 2.
* Python 3.7.0 alpha 1: Python 3 7 0 alpha 1.
* Python 3.6.6 final: Python 3 6 6 final.
* Python 3.6.6 release candidate 1: Python 3 6 6 release candidate 1.
* Python 3.6.5 final: Python 3 6 5 final.
* Python 3.6.5 release candidate 1: Python 3 6 5 release candidate 1.
* Python 3.6.4 final: Python 3 6 4 final.
* Python 3.6.4 release candidate 1: Python 3 6 4 release candidate 1.
* Python 3.6.3 final: Python 3 6 3 final.
* Python 3.6.3 release candidate 1: Python 3 6 3 release candidate 1.
* Python 3.6.2 final: Python 3 6 2 final.
* Python 3.6.2 release candidate 2: Python 3 6 2 release candidate 2.
* Python 3.6.2 release candidate 1: Python 3 6 2 release candidate 1.
* Python 3.6.1 final: Python 3 6 1 final.
* Python 3.6.1 release candidate 1: Python 3 6 1 release candidate 1.
* Python 3.6.0 final: Python 3 6 0 final.
* Python 3.6.0 release candidate 2: Python 3 6 0 release candidate 2.
* Python 3.6.0 release candidate 1: Python 3 6 0 release candidate 1.
* Python 3.6.0 beta 4: Python 3 6 0 beta 4.
* Python 3.6.0 beta 3: Python 3 6 0 beta 3.
* Python 3.6.0 beta 2: Python 3 6 0 beta 2.
* Python 3.6.0 beta 1: Python 3 6 0 beta 1.
* Python 3.6.0 alpha 4: Python 3 6 0 alpha 4.
* Python 3.6.0 alpha 3: Python 3 6 0 alpha 3.
* Python 3.6.0 alpha 2: Python 3 6 0 alpha 2.
* Python 3.6.0 alpha 1: Python 3 6 0 alpha 1.
* Python 3.5.5 final: Python 3 5 5 final.
* Python 3.5.5 release candidate 1: Python 3 5 5 release candidate 1.
* Python 3.5.4 final: Python 3 5 4 final.
* Python 3.5.4 release candidate 1: Python 3 5 4 release candidate 1.
* Python 3.5.3 final: Python 3 5 3 final.
* Python 3.5.3 release candidate 1: Python 3 5 3 release candidate 1.
* Python 3.5.2 final: Python 3 5 2 final.
* Python 3.5.2 release candidate 1: Python 3 5 2 release candidate 1.
* Python 3.5.1 final: Python 3 5 1 final.
* Python 3.5.1 release candidate 1: Python 3 5 1 release candidate 1.
* Python 3.5.0 final: Python 3 5 0 final.
* Python 3.5.0 release candidate 4: Python 3 5 0 release candidate 4.
* Python 3.5.0 release candidate 3: Python 3 5 0 release candidate 3.
* Python 3.5.0 release candidate 2: Python 3 5 0 release candidate 2.
* Python 3.5.0 release candidate 1: Python 3 5 0 release candidate 1.
* Python 3.5.0 beta 4: Python 3 5 0 beta 4.
* Python 3.5.0 beta 3: Python 3 5 0 beta 3.
* Python 3.5.0 beta 2: Python 3 5 0 beta 2.
* Python 3.5.0 beta 1: Python 3 5 0 beta 1.
* Python 3.5.0 alpha 4: Python 3 5 0 alpha 4.
* Python 3.5.0 alpha 3: Python 3 5 0 alpha 3.
* Python 3.5.0 alpha 2: Python 3 5 0 alpha 2.
* Python 3.5.0 alpha 1: Python 3 5 0 alpha 1.


File: python.info,  Node: Python next,  Next: Python 3 14 2 final,  Up: Changelog

1.24.1 Python next
------------------

'Release date: XXXX-XX-XX'

* Menu:

* Windows::
* Tools/Demos::
* Tests::
* Security::
* Library::
* IDLE: IDLE<3>.
* Documentation: Documentation<2>.
* Core and Builtins::
* C API::
* Build::


File: python.info,  Node: Windows,  Next: Tools/Demos,  Up: Python next

1.24.1.1 Windows
................

   - gh-128067(1): Fix a bug in PyREPL on Windows where output without a
     trailing newline was overwritten by the next prompt.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128067


File: python.info,  Node: Tools/Demos,  Next: Tests,  Prev: Windows,  Up: Python next

1.24.1.2 Tools/Demos
....................

   - gh-142095(1): Make gdb “py-bt” command use frame from thread local
     state when available.  Patch by Sam Gross and Victor Stinner.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/142095


File: python.info,  Node: Tests,  Next: Security,  Prev: Tools/Demos,  Up: Python next

1.24.1.3 Tests
..............

   - gh-143460(1): Skip tests relying on infinite recusion if stack size
     is unlimited.

   - gh-65784(2): Add support for parametrized resource ‘wantobjects’ in
     regrtests, which allows to run Tkinter tests with the specified
     value of ‘tkinter.wantobjects’, for example ‘-u wantobjects=0’.

   - gh-143553(3): Add support for parametrized resources, such as ‘-u
     xpickle=2.7’.

   - gh-142836(4): Accommodated Solaris in
     ‘test_pdb.test_script_target_anonymous_pipe’.

   - bpo-31391(5): Forward-port test_xpickle from Python 2 to Python 3
     and add the resource back to test’s command line.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/143460

   (2) https://github.com/python/cpython/issues/65784

   (3) https://github.com/python/cpython/issues/143553

   (4) https://github.com/python/cpython/issues/142836

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31391


File: python.info,  Node: Security,  Next: Library,  Prev: Tests,  Up: Python next

1.24.1.4 Security
.................

   - gh-144125(1): *note BytesGenerator: 13d7. will now refuse to
     serialize (write) headers that are unsafely folded or delimited;
     see *note verify_generated_headers: 4f3.  (Contributed by Bas
     Bloemsaat and Petr Viktorin in gh-121650(2)).

   - gh-143935(3): Fixed a bug in the folding of comments when
     flattening an email message using a modern email policy.  Comments
     consisting of a very long sequence of non-foldable characters could
     trigger a forced line wrap that omitted the required leading space
     on the continuation line, causing the remainder of the comment to
     be interpreted as a new header field.  This enabled header
     injection with carefully crafted inputs.

   - gh-143925(4): Reject control characters in ‘data:’ URL media types.

   - gh-143919(5): Reject control characters in *note
     http.cookies.Morsel: e00. fields and values.

   - gh-143916(6): Reject C0 control characters within
     wsgiref.headers.Headers fields, values, and parameters.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/144125

   (2) https://github.com/python/cpython/issues/121650

   (3) https://github.com/python/cpython/issues/143935

   (4) https://github.com/python/cpython/issues/143925

   (5) https://github.com/python/cpython/issues/143919

   (6) https://github.com/python/cpython/issues/143916


File: python.info,  Node: Library,  Next: IDLE<3>,  Prev: Security,  Up: Python next

1.24.1.5 Library
................

   - gh-144169(1): Fix three crashes when non-string keyword arguments
     are supplied to objects in the *note ast: 9. module.

   - gh-144100(2): Fixed a crash in ctypes when using a deprecated
     ‘POINTER(str)’ type in ‘argtypes’.  Instead of aborting, ctypes now
     raises a proper Python exception when the pointer target type is
     unresolved.

   - gh-144050(3): Fix *note stat.filemode(): 1353. in the pure-Python
     implementation to avoid misclassifying invalid mode values as block
     devices.

   - gh-144023(4): Fixed validation of file descriptor 0 in posix
     functions when used with follow_symlinks parameter.

   - gh-143999(5): Fix an issue where *note inspect.getgeneratorstate():
     143e. and *note inspect.getcoroutinestate(): 101c. could fail for
     generators wrapped by *note types.coroutine(): 108a. in the
     suspended state.

   - gh-143831(6): *note annotationlib.ForwardRef: 175d. objects are now
     hashable when created from annotation scopes with closures.
     Previously, hashing such objects would throw an exception.  Patch
     by Bartosz Sławecki.

   - gh-143874(7): Fixed a bug in *note pdb: aa. where expression
     results were not sent back to remote client.

   - gh-143880(8): Fix data race in *note functools.partial(): 217. in
     the *note free threading: 1f4. build.

   - gh-143706(9): Fix *note multiprocessing: 98. forkserver so that
     *note sys.argv: 146c. is correctly set before ‘__main__’ is
     preloaded.  Previously, *note sys.argv: 146c. was empty during main
     module import in forkserver child processes.  This fixes a
     regression introduced in 3.13.8 and 3.14.1.  Root caused by Aaron
     Wieczorek, test provided by Thomas Watson, thanks!

   - gh-143638(10): Forbid reentrant calls of the *note pickle.Pickler:
     c15. and *note pickle.Unpickler: 175e. methods for the C
     implementation.  Previously, this could cause crash or data
     corruption, now concurrent calls of methods of the same object
     raise *note RuntimeError: 244.

   - gh-78724(11): Raise *note RuntimeError: 244.’s when user attempts
     to call methods on half-initialized *note Struct: 175f. objects,
     For example, created by ‘Struct.__new__(Struct)’.  Patch by Sergey
     B Kirpichev.

   - gh-143196(12): Fix crash when the internal encoder object returned
     by undocumented function ‘json.encoder.c_make_encoder()’ was called
     with non-zero second ('_current_indent_level') argument.

   - gh-143191(13): *note _thread.stack_size(): 1760. now raises *note
     ValueError: 2ec. if the stack size is too small.  Patch by Victor
     Stinner.

   - gh-143602(14): Fix a inconsistency issue in *note write(): 15b3.
     that leads to unexpected buffer overwrite by deduplicating the
     buffer exports.

   - gh-143547(15): Fix *note sys.unraisablehook(): 508. when the hook
     raises an exception and changes *note sys.unraisablehook(): 508.:
     hold a strong reference to the old hook.  Patch by Victor Stinner.

   - gh-143517(16): *note annotationlib.get_annotations(): 459. no
     longer raises a *note SyntaxError: 18e. when evaluating a
     stringified starred annotation that starts with one or more
     whitespace characters followed by a ‘*’.  Patch by Bartosz
     Sławecki.

   - gh-143378(17): Fix use-after-free crashes when a *note BytesIO:
     10a6. object is concurrently mutated during *note write(): 15b3. or
     *note writelines(): 1761.

   - gh-143346(18): Fix incorrect wrapping of the Base64 data in
     ‘plistlib._PlistWriter’ when the indent contains a mix of tabs and
     spaces.

   - gh-143310(19): *note tkinter: f6.: fix a crash when a Python *note
     list: 24d. is mutated during the conversion to a Tcl object (e.g.,
     when setting a Tcl variable).  Patch by Bénédikt Tran.

   - gh-143309(20): Fix a crash in *note os.execve(): 1301. on
     non-Windows platforms when given a custom environment mapping which
     is then mutated during parsing.  Patch by Bénédikt Tran.

   - gh-143308(21): *note pickle: ab.: fix use-after-free crashes when a
     *note PickleBuffer: 1762. is concurrently mutated by a custom
     buffer callback during pickling.  Patch by Bénédikt Tran and Aaron
     Wieczorek.

   - gh-143237(22): Fix support of named pipes in the rotating *note
     logging: 8b. handlers.

   - gh-143249(23): Fix possible buffer leaks in Windows overlapped I/O
     on error handling.

   - gh-143241(24): *note zoneinfo: 13a.: fix infinite loop in *note
     ZoneInfo.from_file: 1763. when parsing a malformed TZif file.
     Patch by Fatih Celik.

   - gh-142830(25): *note sqlite3: d4.: fix use-after-free crashes when
     the connection’s callbacks are mutated during a callback execution.
     Patch by Bénédikt Tran.

   - gh-143200(26): *note xml.etree.ElementTree: 12b.: fix
     use-after-free crashes in *note __getitem__(): 588. and *note
     __setitem__(): 14d3. methods of *note Element: 363. when the
     element is concurrently mutated.  Patch by Bénédikt Tran.

   - gh-142195(27): Updated timeout evaluation logic in *note
     subprocess: dc. to be compatible with deterministic environments
     like Shadow where time moves exactly as requested.

   - gh-142164(28): Fix the ctypes bitfield overflow error message to
     report the correct offset and size calculation.

   - gh-143145(29): Fixed a possible reference leak in ctypes when
     constructing results with multiple output parameters on error.

   - gh-122431(30): Corrected the error message in *note
     readline.append_history_file(): 1053. to state that ‘nelements’
     must be non-negative instead of positive.

   - gh-143004(31): Fix a potential use-after-free in *note
     collections.Counter.update(): 1764. when user code mutates the
     Counter during an update.

   - gh-143046(32): The *note asyncio: b. REPL no longer prints
     copyright and version messages in the quiet mode (*note -q: 1765.).
     Patch by Bartosz Sławecki.

   - gh-140648(33): The *note asyncio: b. REPL now respects the *note
     -I: b59. flag (isolated mode).  Previously, it would load and
     execute *note PYTHONSTARTUP: 1b8. even if the flag was set.
     Contributed by Bartosz Sławecki.

   - gh-142991(34): Fixed socket operations such as recvfrom() and
     sendto() for FreeBSD divert(4) socket.

   - gh-143010(35): Fixed a bug in *note mailbox: 8f. where the precise
     timing of an external event could result in the library opening an
     existing file instead of a file it expected to create.

   - gh-142881(36): Fix concurrent and reentrant call of *note
     atexit.unregister(): 1766.

   - gh-112127(37): Fix possible use-after-free in *note
     atexit.unregister(): 1766. when the callback is unregistered during
     comparison.

   - gh-142783(38): Fix zoneinfo use-after-free with descriptor
     _weak_cache.  a descriptor as _weak_cache could cause crashes
     during object creation.  The fix ensures proper reference counting
     for descriptor-provided objects.

   - gh-142754(39): Add the 'ownerDocument' attribute to *note
     xml.dom.minidom: 128. elements and attributes created by directly
     instantiating the ‘Element’ or ‘Attr’ class.  Note that this way of
     creating nodes is not supported; creator functions like *note
     xml.dom.Document.documentElement(): 1767. should be used instead.

   - gh-142784(40): The *note asyncio: b. REPL now properly closes the
     loop upon the end of interactive session.  Previously, it could
     cause surprising warnings.  Contributed by Bartosz Sławecki.

   - gh-142594(41): Fix crash in ‘TextIOWrapper.close()’ when the
     underlying buffer’s ‘closed’ property calls *note detach(): 1768.

   - gh-142451(42): *note hmac: 6e.: Ensure that the *note
     HMAC.block_size: 114c. attribute is correctly copied by *note
     HMAC.copy: 1769.  Patch by Bénédikt Tran.

   - gh-142495(43): *note collections.defaultdict: 13c4. now prioritizes
     *note __setitem__(): 14d3. when inserting default values from
     ‘default_factory’.  This prevents race conditions where a default
     value would overwrite a value set before ‘default_factory’ returns.

   - gh-142651(44): *note unittest.mock: 10d.: fix a thread safety issue
     where *note Mock.call_count: 176a. may return inaccurate values
     when the mock is called concurrently from multiple threads.

   - gh-142595(45): Added type check during initialization of the *note
     decimal: 3a. module to prevent a crash in case of broken stdlib.
     Patch by Sergey B Kirpichev.

   - gh-142556(46): Fix crash when a task gets re-registered during
     finalization in *note asyncio: b.  Patch by Kumar Aditya.

   - gh-123241(47): Avoid reference count operations in garbage
     collection of *note ctypes: 2e. objects.

   - gh-142517(48): The non-‘compat32’ *note email: 3f. policies now
     correctly handle refolding encoded words that contain bytes that
     can not be decoded in their specified character set.  Previously
     this resulted in an encoding exception during folding.

   - gh-112527(49): The help text for required options in *note
     argparse: 7. no longer extended with « (default: None)».

   - gh-142346(50): Fix usage formatting for mutually exclusive groups
     in *note argparse: 7. when they are preceded by positional
     arguments or followed or intermixed with other optional arguments.

   - gh-142315(51): Pdb can now run scripts from anonymous pipes used in
     process substitution.  Patch by Bartosz Sławecki.

   - gh-142332(52): Fix usage formatting for positional arguments in
     mutually exclusive groups in *note argparse: 7.  in *note argparse:
     7.

   - gh-142282(53): Fix *note winreg.QueryValueEx(): 176b. to not
     accidentally read garbage buffer under race condition.

   - gh-75949(54): Fix *note argparse: 7. to preserve ‘|’ separators in
     mutually exclusive groups when the usage line wraps due to length.

   - gh-142267(55): Improve *note argparse: 7. performance by caching
     the formatter used for argument validation.

   - gh-68552(56): ‘MisplacedEnvelopeHeaderDefect’ and ‘Missing header
     name’ defects are now correctly passed to the ‘handle_defect’
     method of ‘policy’ in *note FeedParser: 176c.

   - gh-142006(57): Fix a bug in the *note email.policy.default: 176d.
     folding algorithm which incorrectly resulted in a doubled newline
     when a line ending at exactly max_line_length was followed by an
     unfoldable token.

   - gh-105836(58): Fix *note asyncio.run_coroutine_threadsafe(): a84.
     leaving underlying cancelled asyncio task running.

   - gh-139971(59): *note pydoc: ba.: Ensure that the link to the online
     documentation of a *note stdlib: 176e. module is correct.

   - gh-139262(60): Some keystrokes can be swallowed in the new ‘PyREPL’
     on Windows, especially when used together with the ALT key.  Fix by
     Chris Eibl.

   - gh-138897(61): Improved *note license: 176f./*note copyright:
     1770./*note credits: 1771. display in the *note REPL: 492.: now
     uses a pager.

   - gh-79986(62): Add parsing for ‘References’ and ‘In-Reply-To’
     headers to the *note email: 3f. library that parses the header
     content as lists of message id tokens.  This prevents them from
     being folded incorrectly.

   - gh-136282(63): Add support for *note UNNAMED_SECTION: 1772. when
     creating a section via the mapping protocol access

   - gh-109263(64): Starting a process from spawn context in *note
     multiprocessing: 98. no longer sets the start method globally.

   - gh-133253(65): Fix thread-safety issues in *note linecache: 89.

   - gh-132715(66): Skip writing objects during marshalling once a
     failure has occurred.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/144169

   (2) https://github.com/python/cpython/issues/144100

   (3) https://github.com/python/cpython/issues/144050

   (4) https://github.com/python/cpython/issues/144023

   (5) https://github.com/python/cpython/issues/143999

   (6) https://github.com/python/cpython/issues/143831

   (7) https://github.com/python/cpython/issues/143874

   (8) https://github.com/python/cpython/issues/143880

   (9) https://github.com/python/cpython/issues/143706

   (10) https://github.com/python/cpython/issues/143638

   (11) https://github.com/python/cpython/issues/78724

   (12) https://github.com/python/cpython/issues/143196

   (13) https://github.com/python/cpython/issues/143191

   (14) https://github.com/python/cpython/issues/143602

   (15) https://github.com/python/cpython/issues/143547

   (16) https://github.com/python/cpython/issues/143517

   (17) https://github.com/python/cpython/issues/143378

   (18) https://github.com/python/cpython/issues/143346

   (19) https://github.com/python/cpython/issues/143310

   (20) https://github.com/python/cpython/issues/143309

   (21) https://github.com/python/cpython/issues/143308

   (22) https://github.com/python/cpython/issues/143237

   (23) https://github.com/python/cpython/issues/143249

   (24) https://github.com/python/cpython/issues/143241

   (25) https://github.com/python/cpython/issues/142830

   (26) https://github.com/python/cpython/issues/143200

   (27) https://github.com/python/cpython/issues/142195

   (28) https://github.com/python/cpython/issues/142164

   (29) https://github.com/python/cpython/issues/143145

   (30) https://github.com/python/cpython/issues/122431

   (31) https://github.com/python/cpython/issues/143004

   (32) https://github.com/python/cpython/issues/143046

   (33) https://github.com/python/cpython/issues/140648

   (34) https://github.com/python/cpython/issues/142991

   (35) https://github.com/python/cpython/issues/143010

   (36) https://github.com/python/cpython/issues/142881

   (37) https://github.com/python/cpython/issues/112127

   (38) https://github.com/python/cpython/issues/142783

   (39) https://github.com/python/cpython/issues/142754

   (40) https://github.com/python/cpython/issues/142784

   (41) https://github.com/python/cpython/issues/142594

   (42) https://github.com/python/cpython/issues/142451

   (43) https://github.com/python/cpython/issues/142495

   (44) https://github.com/python/cpython/issues/142651

   (45) https://github.com/python/cpython/issues/142595

   (46) https://github.com/python/cpython/issues/142556

   (47) https://github.com/python/cpython/issues/123241

   (48) https://github.com/python/cpython/issues/142517

   (49) https://github.com/python/cpython/issues/112527

   (50) https://github.com/python/cpython/issues/142346

   (51) https://github.com/python/cpython/issues/142315

   (52) https://github.com/python/cpython/issues/142332

   (53) https://github.com/python/cpython/issues/142282

   (54) https://github.com/python/cpython/issues/75949

   (55) https://github.com/python/cpython/issues/142267

   (56) https://github.com/python/cpython/issues/68552

   (57) https://github.com/python/cpython/issues/142006

   (58) https://github.com/python/cpython/issues/105836

   (59) https://github.com/python/cpython/issues/139971

   (60) https://github.com/python/cpython/issues/139262

   (61) https://github.com/python/cpython/issues/138897

   (62) https://github.com/python/cpython/issues/79986

   (63) https://github.com/python/cpython/issues/136282

   (64) https://github.com/python/cpython/issues/109263

   (65) https://github.com/python/cpython/issues/133253

   (66) https://github.com/python/cpython/issues/132715


File: python.info,  Node: IDLE<3>,  Next: Documentation<2>,  Prev: Library,  Up: Python next

1.24.1.6 IDLE
.............

   - gh-143774(1): Better explain the operation of Format / Format
     Paragraph.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/143774


File: python.info,  Node: Documentation<2>,  Next: Core and Builtins,  Prev: IDLE<3>,  Up: Python next

1.24.1.7 Documentation
......................

   - gh-140806(1): Add documentation for *note enum.bin(): 1775.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/140806


File: python.info,  Node: Core and Builtins,  Next: C API,  Prev: Documentation<2>,  Up: Python next

1.24.1.8 Core and Builtins
..........................

   - gh-144307(1): Prevent a reference leak in module teardown at
     interpreter finalization.

   - gh-144194(2): Fix error handling in perf jitdump initialization on
     memory allocation failure.

   - gh-144012(3): Check if the result is ‘NULL’ in ‘BINARY_OP_EXTENT’
     opcode.

   - gh-141805(4): Fix crash in *note set: 184. when objects with the
     same hash are concurrently added to the set after removing an
     element with the same hash while the set still contains elements
     with the same hash.

   - gh-143670(5): Fixes a crash in ‘ga_repr_items_list’ function.

   - gh-143377(6): Fix a crash in ‘_interpreters.capture_exception()’
     when the exception is incorrectly formatted.  Patch by Bénédikt
     Tran.

   - gh-136924(7): The interactive help mode in the *note REPL: 492. no
     longer incorrectly syntax highlights text input as Python code.
     Contributed by Olga Matoula.

   - gh-143189(8): Fix crash when inserting a non-*note str: 169. key
     into a split table dictionary when the key matches an existing key
     in the split table but has no corresponding value in the dict.

   - gh-143228(9): Fix use-after-free in perf trampoline when toggling
     profiling while threads are running or during interpreter
     finalization with daemon threads active.  The fix uses reference
     counting to ensure trampolines are not freed while any code object
     could still reference them.  Pach by Pablo Galindo

   - gh-142664(10): Fix a use-after-free crash in *note
     memoryview.__hash__: cf5. when the ‘__hash__’ method of the
     referenced object mutates that object or the view.  Patch by
     Bénédikt Tran.

   - gh-142557(11): Fix a use-after-free crash in *note
     bytearray.__mod__: f83. when the ‘bytearray’ is mutated while
     formatting the ‘%’-style arguments.  Patch by Bénédikt Tran.

   - gh-143195(12): Fix use-after-free crashes in *note bytearray.hex():
     f68. and *note memoryview.hex(): f69. when the separator’s *note
     __len__(): 1777. mutates the original object.  Patch by Bénédikt
     Tran.

   - gh-142975(13): Fix crash after unfreezing all objects tracked by
     the garbage collector on the *note free threaded: 1f4. build.

   - gh-143135(14): Set *note sys.flags.inspect: 1778. to ‘1’ when *note
     PYTHONINSPECT: 16e1. is ‘0’.  Previously, it was set to ‘0’ in this
     case.

   - gh-143003(15): Fix an overflow of the shared empty buffer in *note
     bytearray.extend(): 1779. when ‘__length_hint__()’ returns 0 for
     non-empty iterator.

   - gh-143006(16): Fix a possible assertion error when comparing
     negative non-integer ‘float’ and ‘int’ with the same number of bits
     in the integer part.

   - gh-143057(17): Avoid locking in *note PyTraceMalloc_Track(): db1.
     and *note PyTraceMalloc_Untrack(): db2. when *note tracemalloc:
     105. is not enabled.

   - gh-142776(18): Fix a file descriptor leak in import.c

   - gh-142829(19): Fix a use-after-free crash in *note
     contextvars.Context: 177. comparison when a custom ‘__eq__’ method
     modifies the context via *note set(): 177a.

   - gh-142766(20): Clear the frame of a generator when *note
     generator.close(): 177b. is called.

   - gh-142737(21): Tracebacks will be displayed in fallback mode even
     if *note io.open(): 741. is lost.  Previously, this would crash the
     interpreter.  Patch by Bartosz Sławecki.

   - gh-142554(22): Fix a crash in *note divmod(): b9b. when
     ‘_pylong.int_divmod()’ does not return a tuple of length two
     exactly.  Patch by Bénédikt Tran.

   - gh-142560(23): Fix use-after-free in *note bytearray: 344.
     search-like methods (*note find(): 15ab, *note count(): 177c, *note
     index(): 177d, *note rindex(): 177e, and *note rfind(): 15ac.) by
     marking the storage as exported which causes reallocation attempts
     to raise *note BufferError: 177f.  For *note contains(): ad9, *note
     split(): 1780, and *note rsplit(): 1781. the *note buffer protocol:
     260. is used for this.

   - gh-142531(24): Fix a free-threaded GC performance regression.  If
     there are many untracked tuples, the GC will run too often,
     resulting in poor performance.  The fix is to include untracked
     tuples in the «long lived» object count.  The number of frozen
     objects is also now included since the free-threaded GC must scan
     those too.

   - gh-142402(25): Fix reference counting when adjacent literal parts
     are merged while constructing *note string.templatelib.Template:
     16a, preventing the displaced string object from leaking.

   - gh-133932(26): Fix crash in the free threading build when clearing
     frames that hold tagged integers.

   - gh-142343(27): Fix SIGILL crash on m68k due to incorrect assembly
     constraint.

   - gh-100964(28): Fix reference cycle in exhausted generator frames.
     Patch by Savannah Ostrowski.

   - gh-69605(29): Fix edge-cases around already imported modules in the
     *note REPL: 492. auto-completion of imports.

   - gh-138568(30): Adjusted the built-in *note help(): ad6. function so
     that empty inputs are ignored in interactive mode.

   - gh-137007(31): Fix a bug during JIT compilation failure which
     caused garbage collection debug assertions to fail.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/144307

   (2) https://github.com/python/cpython/issues/144194

   (3) https://github.com/python/cpython/issues/144012

   (4) https://github.com/python/cpython/issues/141805

   (5) https://github.com/python/cpython/issues/143670

   (6) https://github.com/python/cpython/issues/143377

   (7) https://github.com/python/cpython/issues/136924

   (8) https://github.com/python/cpython/issues/143189

   (9) https://github.com/python/cpython/issues/143228

   (10) https://github.com/python/cpython/issues/142664

   (11) https://github.com/python/cpython/issues/142557

   (12) https://github.com/python/cpython/issues/143195

   (13) https://github.com/python/cpython/issues/142975

   (14) https://github.com/python/cpython/issues/143135

   (15) https://github.com/python/cpython/issues/143003

   (16) https://github.com/python/cpython/issues/143006

   (17) https://github.com/python/cpython/issues/143057

   (18) https://github.com/python/cpython/issues/142776

   (19) https://github.com/python/cpython/issues/142829

   (20) https://github.com/python/cpython/issues/142766

   (21) https://github.com/python/cpython/issues/142737

   (22) https://github.com/python/cpython/issues/142554

   (23) https://github.com/python/cpython/issues/142560

   (24) https://github.com/python/cpython/issues/142531

   (25) https://github.com/python/cpython/issues/142402

   (26) https://github.com/python/cpython/issues/133932

   (27) https://github.com/python/cpython/issues/142343

   (28) https://github.com/python/cpython/issues/100964

   (29) https://github.com/python/cpython/issues/69605

   (30) https://github.com/python/cpython/issues/138568

   (31) https://github.com/python/cpython/issues/137007


File: python.info,  Node: C API,  Next: Build,  Prev: Core and Builtins,  Up: Python next

1.24.1.9 C API
..............

   - gh-142589(1): Fix *note
     PyUnstable_Object_IsUniqueReferencedTemporary(): 3c7. handling of
     tagged ints on the interpreter stack.

   - gh-142571(2): ‘PyUnstable_CopyPerfMapFile()’ now checks that
     opening the file succeeded before flushing.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/142589

   (2) https://github.com/python/cpython/issues/142571


File: python.info,  Node: Build,  Prev: C API,  Up: Python next

1.24.1.10 Build
...............

   - gh-142454(1): When calculating the digest of the JIT stencils
     input, sort the hashed files by filenames before adding their
     content to the hasher.  This ensures deterministic hash input and
     hence deterministic hash, independent on filesystem order.

   - gh-141808(2): When running ‘make clean-retain-profile’, keep the
     generated JIT stencils.  That way, the stencils are not generated
     twice when Profile-guided optimization (PGO) is used.  It also
     allows distributors to supply their own pre-built JIT stencils.

   - gh-138061(3): Ensure reproducible builds by making JIT stencil
     header generation deterministic.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/142454

   (2) https://github.com/python/cpython/issues/141808

   (3) https://github.com/python/cpython/issues/138061


File: python.info,  Node: Python 3 14 2 final,  Next: Python 3 14 1 final,  Prev: Python next,  Up: Changelog

1.24.2 Python 3.14.2 final
--------------------------

'Release date: 2025-12-05'

* Menu:

* Security: Security<2>.
* Library: Library<2>.
* Core and Builtins: Core and Builtins<2>.
* Library: Library<3>.


File: python.info,  Node: Security<2>,  Next: Library<2>,  Up: Python 3 14 2 final

1.24.2.1 Security
.................

   - gh-142145(1): Remove quadratic behavior in ‘xml.minidom’ node ID
     cache clearing.

   - gh-119452(2): Fix a potential memory denial of service in the *note
     http.server: 76. module.  When a malicious user is connected to the
     CGI server on Windows, it could cause an arbitrary amount of memory
     to be allocated.  This could have led to symptoms including a *note
     MemoryError: 1786, swapping, out of memory (OOM) killed processes
     or containers, or even system crashes.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/142145

   (2) https://github.com/python/cpython/issues/119452


File: python.info,  Node: Library<2>,  Next: Core and Builtins<2>,  Prev: Security<2>,  Up: Python 3 14 2 final

1.24.2.2 Library
................

   - gh-140797(1): Revert changes to the undocumented ‘re.Scanner’
     class.  Capturing groups are still allowed for backward
     compatibility, although using them can lead to incorrect result.
     They will be forbidden in future Python versions.

   - gh-142206(2): The resource tracker in the *note multiprocessing:
     98. module now uses the original communication protocol, as in
     Python 3.14.0 and below, by default.  This avoids issues with
     upgrading Python while it is running.  (Note that such “in-place”
     upgrades are not tested.)  The tracker remains compatible with
     subprocesses that use new protocol (that is, subprocesses using
     Python 3.13.10, 3.14.1 and 3.15).

   - gh-142214(3): Fix two regressions in *note dataclasses: 33. in
     Python 3.14.1 related to annotations.

        * An exception is no longer raised if ‘slots=True’ is used and
          the ‘__init__’ method does not have an ‘__annotate__’
          attribute (likely because ‘init=False’ was used).

        * An exception is no longer raised if annotations are requested
          on the ‘__init__’ method and one of the fields is not present
          in the class annotations.  This can occur in certain dynamic
          scenarios.

     Patch by Jelle Zijlstra.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/140797

   (2) https://github.com/python/cpython/issues/142206

   (3) https://github.com/python/cpython/issues/142214


File: python.info,  Node: Core and Builtins<2>,  Next: Library<3>,  Prev: Library<2>,  Up: Python 3 14 2 final

1.24.2.3 Core and Builtins
..........................

   - gh-142218(1): Fix crash when inserting into a split table
     dictionary with a non *note str: 169. key that matches an existing
     key.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/142218


File: python.info,  Node: Library<3>,  Prev: Core and Builtins<2>,  Up: Python 3 14 2 final

1.24.2.4 Library
................

   - gh-116738(1): Fix *note cmath: 19. data race when initializing
     trigonometric tables with subinterpreters.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116738


File: python.info,  Node: Python 3 14 1 final,  Next: Python 3 14 0 final,  Prev: Python 3 14 2 final,  Up: Changelog

1.24.3 Python 3.14.1 final
--------------------------

'Release date: 2025-12-02'

* Menu:

* Windows: Windows<2>.
* Tools/Demos: Tools/Demos<2>.
* Tests: Tests<2>.
* Security: Security<3>.
* Library: Library<4>.
* IDLE: IDLE<4>.
* Documentation: Documentation<3>.
* Core and Builtins: Core and Builtins<3>.
* Library: Library<5>.
* Core and Builtins: Core and Builtins<4>.
* Library: Library<6>.
* Core and Builtins: Core and Builtins<5>.
* Library: Library<7>.
* Core and Builtins: Core and Builtins<6>.
* Library: Library<8>.
* Core and Builtins: Core and Builtins<7>.
* Library: Library<9>.
* Core and Builtins: Core and Builtins<8>.
* Library: Library<10>.
* Core and Builtins: Core and Builtins<9>.
* C API: C API<2>.
* Build: Build<2>.


File: python.info,  Node: Windows<2>,  Next: Tools/Demos<2>,  Up: Python 3 14 1 final

1.24.3.1 Windows
................

   - gh-139810(1): Installing with ‘py install 3[.x]-dev’ will now
     select final versions as well as prereleases.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/139810


File: python.info,  Node: Tools/Demos<2>,  Next: Tests<2>,  Prev: Windows<2>,  Up: Python 3 14 1 final

1.24.3.2 Tools/Demos
....................

   - gh-141692(1): Each slice of an iOS XCframework now contains a ‘lib’
     folder that contains a symlink to the libpython dylib.  This allows
     binary modules to be compiled for iOS using dynamic libreary
     linking, rather than Framework linking.

   - gh-141442(2): The iOS testbed now correctly handles test arguments
     that contain spaces.

   - gh-140702(3): The iOS testbed app will now expose the
     ‘GITHUB_ACTIONS’ environment variable to iOS apps being tested.

   - gh-137484(4): Have ‘Tools/wasm/wasi’ put the build Python into a
     directory named after the build triple instead of «build».

   - gh-137248(5): Add a ‘--logdir’ option to ‘Tools/wasm/wasi’ for
     specifying where to write log files.

   - gh-137243(6): Have Tools/wasm/wasi detect a WASI SDK install in
     /opt when it was directly extracted from a release tarball.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/141692

   (2) https://github.com/python/cpython/issues/141442

   (3) https://github.com/python/cpython/issues/140702

   (4) https://github.com/python/cpython/issues/137484

   (5) https://github.com/python/cpython/issues/137248

   (6) https://github.com/python/cpython/issues/137243


File: python.info,  Node: Tests<2>,  Next: Security<3>,  Prev: Tools/Demos<2>,  Up: Python 3 14 1 final

1.24.3.3 Tests
..............

   - gh-140482(1): Preserve and restore the state of ‘stty echo’ as part
     of the test environment.

   - gh-140082(2): Update ‘python -m test’ to set ‘FORCE_COLOR=1’ when
     being run with color enabled so that *note unittest: 10c. which is
     run by it with redirected output will output in color.

   - gh-139208(3): Fix regrtest ‘--fast-ci --verbose’: don’t ignore the
     ‘--verbose’ option anymore.  Patch by Victor Stinner.

   - gh-136442(4): Use exitcode ‘1’ instead of ‘5’ if *note
     unittest.TestCase.setUpClass(): c45. raises an exception

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/140482

   (2) https://github.com/python/cpython/issues/140082

   (3) https://github.com/python/cpython/issues/139208

   (4) https://github.com/python/cpython/issues/136442


File: python.info,  Node: Security<3>,  Next: Library<4>,  Prev: Tests<2>,  Up: Python 3 14 1 final

1.24.3.4 Security
.................

   - gh-139700(1): Check consistency of the zip64 end of central
     directory record.  Support records with «zip64 extensible data» if
     there are no bytes prepended to the ZIP file.

   - gh-139283(2): *note sqlite3: d4.: correctly handle maximum number
     of rows to fetch in *note Cursor.fetchmany: 178f. and reject
     negative values for *note Cursor.arraysize: 1790.  Patch by
     Bénédikt Tran.

   - gh-137836(3): Add support of the «plaintext» element, RAWTEXT
     elements «xmp», «iframe», «noembed» and «noframes», and optionally
     RAWTEXT element «noscript» in *note html.parser.HTMLParser: a79.

   - gh-136063(4): *note email.message: 48.: ensure linear complexity
     for legacy HTTP parameters parsing.  Patch by Bénédikt Tran.

   - gh-136065(5): Fix quadratic complexity in *note
     os.path.expandvars(): 15e0.

   - gh-119451(6): Fix a potential memory denial of service in the *note
     http.client: 73. module.  When connecting to a malicious server, it
     could cause an arbitrary amount of memory to be allocated.  This
     could have led to symptoms including a *note MemoryError: 1786,
     swapping, out of memory (OOM) killed processes or containers, or
     even system crashes.

   - gh-119342(7): Fix a potential memory denial of service in the *note
     plistlib: b0. module.  When reading a Plist file received from
     untrusted source, it could cause an arbitrary amount of memory to
     be allocated.  This could have led to symptoms including a *note
     MemoryError: 1786, swapping, out of memory (OOM) killed processes
     or containers, or even system crashes.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/139700

   (2) https://github.com/python/cpython/issues/139283

   (3) https://github.com/python/cpython/issues/137836

   (4) https://github.com/python/cpython/issues/136063

   (5) https://github.com/python/cpython/issues/136065

   (6) https://github.com/python/cpython/issues/119451

   (7) https://github.com/python/cpython/issues/119342


File: python.info,  Node: Library<4>,  Next: IDLE<4>,  Prev: Security<3>,  Up: Python 3 14 1 final

1.24.3.5 Library
................

   - gh-74389(1): When the stdin being used by a *note subprocess.Popen:
     4b8. instance is closed, this is now ignored in *note
     subprocess.Popen.communicate(): 1792. instead of leaving the class
     in an inconsistent state.

   - gh-87512(2): Fix *note subprocess.Popen.communicate(): 1792.
     timeout handling on Windows when writing large input.  Previously,
     the timeout was ignored during stdin writing, causing the method to
     block indefinitely if the child process did not consume input
     quickly.  The stdin write is now performed in a background thread,
     allowing the timeout to be properly enforced.

   - gh-141473(3): When *note subprocess.Popen.communicate(): 1792. was
     called with 'input' and a 'timeout' and is called for a second time
     after a *note TimeoutExpired: 1793. exception before the process
     has died, it should no longer hang.

   - gh-59000(4): Fix *note pdb: aa. breakpoint resolution for class
     methods when the module defining the class is not imported.

   - gh-141570(5): Support *note file-like object: 1794. raising *note
     OSError: 2c0. from *note fileno(): 1795. in color detection
     (‘_colorize.can_colorize()’).  This can occur when ‘sys.stdout’ is
     redirected.

   - gh-141659(6): Fix bad file descriptor errors from
     ‘_posixsubprocess’ on AIX.

   - gh-141600(7): Fix musl version detection on Void Linux.

   - gh-141497(8): *note ipaddress: 84.: ensure that the methods *note
     IPv4Network.hosts(): 1796. and *note IPv6Network.hosts(): 1797.
     always return an iterator.

   - gh-140938(9): The *note statistics.stdev(): 8e4. and *note
     statistics.pstdev(): 1798. functions now raise a *note ValueError:
     2ec. when the input contains an infinity or a NaN.

   - gh-124111(10): Updated Tcl threading configuration in *note
     _tkinter: 3. to assume that threads are always available in Tcl 9
     and later.

   - gh-137109(11): The *note os.fork: 4b6. and related forking APIs
     will no longer warn in the common case where Linux or macOS
     platform APIs return the number of threads in a process and find
     the answer to be 1 even when a *note os.register_at_fork(): 355.
     ‘after_in_parent=’ callback (re)starts a thread.

   - gh-141314(12): Fix assertion failure in *note
     io.TextIOWrapper.tell(): 1799. when reading files with standalone
     carriage return (‘\r’) line endings.

   - gh-141311(13): Fix assertion failure in ‘io.BytesIO.readinto()’ and
     undefined behavior arising when read position is above capcity in
     *note io.BytesIO: 10a6.

   - gh-141141(14): Fix a thread safety issue with *note
     base64.b85decode(): 1125.  Contributed by Benel Tayar.

   - gh-137969(15): Fix *note annotationlib.ForwardRef.evaluate(): 179a.
     returning *note ForwardRef: 175d. objects which don’t update with
     new globals.

   - gh-140911(16): *note collections: 1e.: Ensure that the methods
     ‘UserString.rindex()’ and ‘UserString.index()’ accept *note
     collections.UserString: fd5. instances as the sub argument.

   - gh-140797(17): The undocumented ‘re.Scanner’ class now forbids
     regular expressions containing capturing groups in its lexicon
     patterns.  Patterns using capturing groups could previously lead to
     crashes with segmentation fault.  Use non-capturing groups (?:…)
     instead.

   - gh-125115(18): Refactor the *note pdb: aa. parsing issue so
     positional arguments can pass through intuitively.

   - gh-140815(19): *note faulthandler: 5c. now detects if a frame or a
     code object is invalid or freed.  Patch by Victor Stinner.

   - gh-100218(20): Correctly set *note errno: 179b. when *note
     socket.if_nametoindex(): c25. or *note socket.if_indextoname():
     c26. raise an *note OSError: 2c0.  Patch by Bénédikt Tran.

   - gh-140875(21): Fix handling of unclosed character references (named
     and numerical) followed by the end of file in *note
     html.parser.HTMLParser: a79. with ‘convert_charrefs=False’.

   - gh-140734(22): *note multiprocessing: 98.: fix off-by-one error
     when checking the length of a temporary socket file path.  Patch by
     Bénédikt Tran.

   - gh-140874(23): Bump the version of pip bundled in ensurepip to
     version 25.3

   - gh-140691(24): In *note urllib.request: 111, when opening a FTP URL
     fails because a data connection cannot be made, the control
     connection’s socket is now closed to avoid a *note ResourceWarning:
     54d.

   - gh-103847(25): Fix hang when cancelling process created by *note
     asyncio.create_subprocess_exec(): c6d. or *note
     asyncio.create_subprocess_shell(): c6e.  Patch by Kumar Aditya.

   - gh-120057(26): Add *note os.reload_environ(): 258. to ‘os.__all__’.

   - gh-140228(27): Avoid making unnecessary filesystem calls for frozen
     modules in *note linecache: 89. when the global module cache is not
     present.

   - gh-140590(28): Fix arguments checking for the
     ‘functools.partial.__setstate__()’ that may lead to internal state
     corruption and crash.  Patch by Sergey Miryanov.

   - gh-125434(29): Display thread name in *note faulthandler: 5c. on
     Windows.  Patch by Victor Stinner.

   - gh-140634(30): Fix a reference counting bug in
     ‘os.sched_param.__reduce__()’.

   - gh-140633(31): Ignore *note AttributeError: 5f0. when setting a
     module’s ‘__file__’ attribute when loading an extension module
     packaged as Apple Framework.

   - gh-140593(32): *note xml.parsers.expat: 12c.: Fix a memory leak
     that could affect users with *note ElementDeclHandler(): 179c. set
     to a custom element declaration handler.  Patch by Sebastian
     Pipping.

   - gh-140607(33): Inside *note io.RawIOBase.read(): 101f, validate
     that the count of bytes returned by *note io.RawIOBase.readinto():
     1020. is valid (inside the provided buffer).

   - gh-138162(34): Fix *note logging.LoggerAdapter: 14fd. with
     ‘merge_extra=True’ and without the 'extra' argument.

   - gh-138774(35): *note ast.unparse(): ae4. now generates full source
     code when handling *note ast.Interpolation: 179d. nodes that do not
     have a specified source.

   - gh-140474(36): Fix memory leak in *note array.array: 4bf. when
     creating arrays from an empty *note str: 169. and the ‘u’ type
     code.

   - gh-137530(37): *note dataclasses: 33. Fix annotations for generated
     ‘__init__’ methods by replacing the annotations that were in-line
     in the generated source code with ‘__annotate__’ functions attached
     to the methods.

   - gh-140348(38): Fix regression in Python 3.14.0 where using the ‘|’
     operator on a *note typing.Union: 2a8. object combined with an
     object that is not a type would raise an error.

   - gh-140272(39): Fix memory leak in the ‘clear()’ method of the *note
     dbm.gnu: 37. database.

   - gh-140041(40): Fix import of *note ctypes: 2e. on Android and
     Cygwin when ABI flags are present.

   - gh-140120(41): Fixed a memory leak in *note hmac: 6e. when it was
     using the hacl-star backend.  Discovered by ‘@ashm-dev’ using
     AddressSanitizer.

   - gh-139905(42): Add suggestion to error message for *note
     typing.Generic: 179e. subclasses when ‘cls.__parameters__’ is
     missing due to a parent class failing to call *note
     super().__init_subclass__(): 844. in its ‘__init_subclass__’.

   - gh-139894(43): Fix incorrect sharing of current task with the child
     process while forking in *note asyncio: b.  Patch by Kumar Aditya.

   - gh-139845(44): Fix to not print KeyboardInterrupt twice in default
     asyncio REPL.

   - gh-139783(45): Fix *note inspect.getsourcelines(): 179f. for the
     case when a decorator is followed by a comment or an empty line.

   - gh-139809(46): Prevent premature colorization of subparser ‘prog’
     in *note argparse.ArgumentParser.add_subparsers(): e13. to respect
     color environment variable changes after parser creation.

   - gh-139736(47): Fix excessive indentation in the default *note
     argparse: 7. ‘HelpFormatter’.  Patch by Alexander Edland.

   - gh-70765(48): *note http.server: 76.: fix default handling of
     HTTP/0.9 requests in *note BaseHTTPRequestHandler: 12d3.
     Previously, ‘BaseHTTPRequestHandler.parse_request()’ incorrectly
     waited for headers in the request although those are not supported
     in HTTP/0.9.  Patch by Bénédikt Tran.

   - gh-63161(49): Fix *note tokenize.detect_encoding(): 17a0.  Support
     non-UTF-8 shebang and comments if non-UTF-8 encoding is specified.
     Detect decoding error for non-UTF-8 encoding.  Detect null bytes in
     source code.

   - gh-139391(50): Fix an issue when, on non-Windows platforms, it was
     not possible to gracefully exit a ‘python -m asyncio’ process
     suspended by Ctrl+Z and later resumed by ‘fg(51)’ other than with
     ‘kill(52)’.

   - gh-101828(53): Fix ‘'shift_jisx0213'’, ‘'shift_jis_2004'’,
     ‘'euc_jisx0213'’ and ‘'euc_jis_2004'’ codecs truncating null chars
     as they were treated as part of multi-character sequences.

   - gh-139289(54): Do a real lazy-import on *note rlcompleter: c2. in
     *note pdb: aa. and restore the existing completer after importing
     *note rlcompleter: c2.

   - gh-139246(55): fix: paste zero-width in default repl width is
     wrong.

   - gh-90949(56): Add *note SetAllocTrackerActivationThreshold(): 17a1.
     and *note SetAllocTrackerMaximumAmplification(): 17a2. to *note
     xmlparser: 17a3. objects to prevent use of disproportional amounts
     of dynamic memory from within an Expat parser.  Patch by Bénédikt
     Tran.

   - gh-139210(57): Fix use-after-free when reporting unknown event in
     *note xml.etree.ElementTree.iterparse(): 57a.  Patch by Ken Jin.

   - gh-138860(58): Lazy import *note rlcompleter: c2. in *note pdb: aa.
     to avoid deadlock in subprocess.

   - gh-112729(59): Fix crash when calling *note
     concurrent.interpreters.create(): 17a4. when the process is out of
     memory.

   - gh-135729(60): Fix unraisable exception during finalization when
     using *note concurrent.interpreters: 25. in the REPL.

   - gh-139076(61): Fix a bug in the *note pydoc: ba. module that was
     hiding functions in a Python module if they were implemented in an
     extension module and the module did not have ‘__all__’.

   - gh-139065(62): Fix trailing space before a wrapped long word if the
     line length is exactly 'width' in *note textwrap: f2.

   - gh-139001(63): Fix race condition in *note pathlib.Path: 266. on
     the internal ‘_raw_paths’ field.

   - gh-138813(64): ‘multiprocessing.BaseProcess’ defaults ‘kwargs’ to
     ‘None’ instead of a shared dictionary.

   - gh-138993(65): Dedent *note credits: 1771. text.

   - gh-138891(66): Fix ‘SyntaxError’ when ‘inspect.get_annotations(f,
     eval_str=True)’ is called on a function annotated with a PEP
     646(67) ‘star_expression’

   - gh-130567(68): Fix possible crash in *note locale.strxfrm(): 17a5.
     due to a platform bug on macOS.

   - gh-138859(69): Fix generic type parameterization raising a *note
     TypeError: 198. when omitting a ‘ParamSpec’ that has a default
     which is not a list of types.

   - gh-138764(70): Prevent *note
     annotationlib.call_annotate_function(): 17a6. from calling
     ‘__annotate__’ functions that don’t support
     ‘VALUE_WITH_FAKE_GLOBALS’ in a fake globals namespace with empty
     globals.

     Make ‘FORWARDREF’ and ‘STRING’ annotations fall back to using
     ‘VALUE’ annotations in the case that neither their own format, nor
     ‘VALUE_WITH_FAKE_GLOBALS’ are supported.

   - gh-138775(71): Use of ‘python -m’ with *note base64: f. has been
     fixed to detect input from a terminal so that it properly notices
     EOF.

   - gh-138779(72): Support device numbers larger than ‘2**63-1’ for the
     *note st_rdev: 17a7. field of the *note os.stat_result: 16c8.
     structure.

   - gh-137706(73): Fix the partial evaluation of annotations that use
     ‘typing.Annotated[T, x]’ where ‘T’ is a forward reference.

   - gh-88375(74): Fix normalization of the ‘robots.txt’ rules and URLs
     in the *note urllib.robotparser: 113. module.  No longer ignore
     trailing ‘?’.  Distinguish raw special characters ‘?’, ‘=’ and ‘&’
     from the percent-encoded ones.

   - gh-111788(75): Fix parsing errors in the *note urllib.robotparser:
     113. module.  Don’t fail trying to parse weird paths.  Don’t fail
     trying to decode non-UTF-8 ‘robots.txt’ files.

   - gh-98896(76): Fix a failure in multiprocessing resource_tracker
     when SharedMemory names contain colons.  Patch by Rani Pinchuk.

   - gh-138425(77): Fix partial evaluation of *note
     annotationlib.ForwardRef: 175d. objects which rely on names defined
     as globals.

   - gh-138432(78): *note zoneinfo.reset_tzpath(): 17a8. will now
     convert any *note os.PathLike: e4d. objects it receives into
     strings before adding them to ‘TZPATH’.  It will raise ‘TypeError’
     if anything other than a string is found after this conversion.  If
     given an *note os.PathLike: e4d. object that represents a relative
     path, it will now raise ‘ValueError’ instead of ‘TypeError’, and
     present a more informative error message.

   - gh-138008(79): Fix segmentation faults in the *note ctypes: 2e.
     module due to invalid *note argtypes: 17a9.  Patch by Dung Nguyen.

   - gh-60462(80): Fix *note locale.strxfrm(): 17a5. on Solaris (and
     possibly other platforms).

   - gh-138239(81): The REPL now highlights *note type: 66d. as a soft
     keyword in *note type statements: 66d.

   - gh-138204(82): Forbid expansion of shared anonymous *note memory
     maps: 94. on Linux, which caused a bus error.

   - gh-138010(83): Fix an issue where defining a class with an *note
     @warnings.deprecated: 48a.-decorated base class may not invoke the
     correct *note __init_subclass__(): 844. method in cases involving
     multiple inheritance.  Patch by Brian Schubert.

   - gh-138151(84): In *note annotationlib: 6, improve evaluation of
     forward references to nonlocal variables that are not yet defined
     when the annotations are initially evaluated.

   - gh-137317(85): *note inspect.signature(): 22f. now correctly
     handles classes that use a descriptor on a wrapped ‘__init__()’ or
     ‘__new__()’ method.  Contributed by Yongyu Yan.

   - gh-137754(86): Fix import of the *note zoneinfo: 13a. module if the
     C implementation of the *note datetime: 34. module is not
     available.

   - gh-137490(87): Handle *note ECANCELED: 17aa. in the same way as
     *note EINTR: f89. in *note signal.sigwaitinfo(): fad. on NetBSD.

   - gh-137477(88): Fix ‘inspect.getblock()’, *note
     inspect.getsourcelines(): 179f. and *note inspect.getsource():
     17ab. for generator expressions.

   - gh-137044(89): Return large limit values as positive integers
     instead of negative integers in *note resource.getrlimit(): 17ac.
     Accept large values and reject negative values (except *note
     RLIM_INFINITY: 17ad.) for limits in *note resource.setrlimit():
     17ae.

   - gh-75989(90): *note tarfile.TarFile.extractall(): 29b. and *note
     tarfile.TarFile.extract(): 29c. now overwrite symlinks when
     extracting hardlinks.  (Contributed by Alexander Enrique Urieles
     Nieto in gh-75989(91).)

   - gh-137017(92): Fix *note threading.Thread.is_alive: b48. to remain
     ‘True’ until the underlying OS thread is fully cleaned up.  This
     avoids false negatives in edge cases involving thread monitoring or
     premature *note threading.Thread.is_alive: b48. calls.

   - gh-137273(93): Fix debug assertion failure in *note
     locale.setlocale(): 328. on Windows.

   - gh-137239(94): *note heapq: 6d.: Update ‘heapq.__all__’ with
     ‘*_max’ functions.

   - gh-81325(95): *note tarfile.TarFile: 1418. now accepts a *note
     path-like: 5a1. when working on a tar archive.  (Contributed by
     Alexander Enrique Urieles Nieto in gh-81325(96).)

   - gh-137185(97): Fix a potential async-signal-safety issue in *note
     faulthandler: 5c. when printing C stack traces.

   - gh-136914(98): Fix retrieval of *note doctest.DocTest.lineno: 17af.
     for objects decorated with *note functools.cache(): 17b0. or *note
     functools.cached_property: 764.

   - gh-136912(99): *note hmac.digest(): d34. now properly handles large
     keys and messages by falling back to the pure Python implementation
     when necessary.  Patch by Bénédikt Tran.

   - gh-83424(100): Allows creating a *note ctypes.CDLL: bde. without
     name when passing a handle as an argument.

   - gh-136234(101): Fix *note asyncio.WriteTransport.writelines():
     17b1. to be robust to connection failure, by using the same
     behavior as *note write(): 17b2.

   - gh-136507(102): Fix mimetypes CLI to handle multiple file
     parameters.

   - gh-136057(103): Fixed the bug in *note pdb: aa. and *note bdb: 10.
     where ‘next’ and ‘step’ can’t go over the line if a loop exists in
     the line.

   - gh-135386(104): Fix opening a *note dbm.sqlite3: 39. database for
     reading from read-only file or directory.

   - gh-135444(105): Fix *note asyncio.DatagramTransport.sendto(): 4cc.
     to account for datagram header size when data cannot be sent.

   - gh-126631(106): Fix *note multiprocessing: 98. ‘forkserver’ bug
     which prevented ‘__main__’ from being preloaded.

   - gh-135307(107): *note email: 3f.: Fix exception in ‘set_content()’
     when encoding text and max_line_length is set to ‘0’ or ‘None’
     (unlimited).

   - gh-134453(108): Fixed *note subprocess.Popen.communicate(): 1792.
     ‘input=’ handling of *note memoryview: 165. instances that were
     non-byte shaped on POSIX platforms.  Those are now properly cast to
     a byte shaped view instead of truncating the input.  Windows
     platforms did not have this bug.

   - gh-134698(109): Fix a crash when calling methods of *note
     ssl.SSLContext: 357. or *note ssl.SSLSocket: ae9. across multiple
     threads.

   - gh-125996(110): Fix thread safety of *note collections.OrderedDict:
     7f4.  Patch by Kumar Aditya.

   - gh-133789(111): Fix unpickling of *note pathlib: a8. objects that
     were pickled in Python 3.13.

   - gh-127081(112): Fix libc thread safety issues with *note dbm: 35.
     by performing stateful operations in critical sections.

   - gh-132551(113): Make *note io.BytesIO: 10a6. safe in *note
     free-threaded: 1f4. build.

   - gh-131788(114): Make ‘ResourceTracker.send’ from *note
     multiprocessing: 98. re-entrant safe

   - gh-118981(115): Fix potential hang in
     ‘multiprocessing.popen_spawn_posix’ that can happen when the child
     proc dies early by closing the child fds right away.

   - gh-102431(116): Clarify constraints for «logical» arguments in
     methods of *note decimal.Context: 12b7.

   - gh-78319(117): UTF8 support for the IMAP APPEND command has been
     made RFC compliant.

   - bpo-38735(118): Fix failure when importing a module from the root
     directory on unix-like platforms with sys.pycache_prefix set.

   - bpo-41839(119): Allow negative priority values from *note
     os.sched_get_priority_min(): 1311. and *note
     os.sched_get_priority_max(): 1310. functions.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/74389

   (2) https://github.com/python/cpython/issues/87512

   (3) https://github.com/python/cpython/issues/141473

   (4) https://github.com/python/cpython/issues/59000

   (5) https://github.com/python/cpython/issues/141570

   (6) https://github.com/python/cpython/issues/141659

   (7) https://github.com/python/cpython/issues/141600

   (8) https://github.com/python/cpython/issues/141497

   (9) https://github.com/python/cpython/issues/140938

   (10) https://github.com/python/cpython/issues/124111

   (11) https://github.com/python/cpython/issues/137109

   (12) https://github.com/python/cpython/issues/141314

   (13) https://github.com/python/cpython/issues/141311

   (14) https://github.com/python/cpython/issues/141141

   (15) https://github.com/python/cpython/issues/137969

   (16) https://github.com/python/cpython/issues/140911

   (17) https://github.com/python/cpython/issues/140797

   (18) https://github.com/python/cpython/issues/125115

   (19) https://github.com/python/cpython/issues/140815

   (20) https://github.com/python/cpython/issues/100218

   (21) https://github.com/python/cpython/issues/140875

   (22) https://github.com/python/cpython/issues/140734

   (23) https://github.com/python/cpython/issues/140874

   (24) https://github.com/python/cpython/issues/140691

   (25) https://github.com/python/cpython/issues/103847

   (26) https://github.com/python/cpython/issues/120057

   (27) https://github.com/python/cpython/issues/140228

   (28) https://github.com/python/cpython/issues/140590

   (29) https://github.com/python/cpython/issues/125434

   (30) https://github.com/python/cpython/issues/140634

   (31) https://github.com/python/cpython/issues/140633

   (32) https://github.com/python/cpython/issues/140593

   (33) https://github.com/python/cpython/issues/140607

   (34) https://github.com/python/cpython/issues/138162

   (35) https://github.com/python/cpython/issues/138774

   (36) https://github.com/python/cpython/issues/140474

   (37) https://github.com/python/cpython/issues/137530

   (38) https://github.com/python/cpython/issues/140348

   (39) https://github.com/python/cpython/issues/140272

   (40) https://github.com/python/cpython/issues/140041

   (41) https://github.com/python/cpython/issues/140120

   (42) https://github.com/python/cpython/issues/139905

   (43) https://github.com/python/cpython/issues/139894

   (44) https://github.com/python/cpython/issues/139845

   (45) https://github.com/python/cpython/issues/139783

   (46) https://github.com/python/cpython/issues/139809

   (47) https://github.com/python/cpython/issues/139736

   (48) https://github.com/python/cpython/issues/70765

   (49) https://github.com/python/cpython/issues/63161

   (50) https://github.com/python/cpython/issues/139391

   (51) https://manpages.debian.org/fg

   (52) https://manpages.debian.org/kill

   (53) https://github.com/python/cpython/issues/101828

   (54) https://github.com/python/cpython/issues/139289

   (55) https://github.com/python/cpython/issues/139246

   (56) https://github.com/python/cpython/issues/90949

   (57) https://github.com/python/cpython/issues/139210

   (58) https://github.com/python/cpython/issues/138860

   (59) https://github.com/python/cpython/issues/112729

   (60) https://github.com/python/cpython/issues/135729

   (61) https://github.com/python/cpython/issues/139076

   (62) https://github.com/python/cpython/issues/139065

   (63) https://github.com/python/cpython/issues/139001

   (64) https://github.com/python/cpython/issues/138813

   (65) https://github.com/python/cpython/issues/138993

   (66) https://github.com/python/cpython/issues/138891

   (67) https://peps.python.org/pep-0646/

   (68) https://github.com/python/cpython/issues/130567

   (69) https://github.com/python/cpython/issues/138859

   (70) https://github.com/python/cpython/issues/138764

   (71) https://github.com/python/cpython/issues/138775

   (72) https://github.com/python/cpython/issues/138779

   (73) https://github.com/python/cpython/issues/137706

   (74) https://github.com/python/cpython/issues/88375

   (75) https://github.com/python/cpython/issues/111788

   (76) https://github.com/python/cpython/issues/98896

   (77) https://github.com/python/cpython/issues/138425

   (78) https://github.com/python/cpython/issues/138432

   (79) https://github.com/python/cpython/issues/138008

   (80) https://github.com/python/cpython/issues/60462

   (81) https://github.com/python/cpython/issues/138239

   (82) https://github.com/python/cpython/issues/138204

   (83) https://github.com/python/cpython/issues/138010

   (84) https://github.com/python/cpython/issues/138151

   (85) https://github.com/python/cpython/issues/137317

   (86) https://github.com/python/cpython/issues/137754

   (87) https://github.com/python/cpython/issues/137490

   (88) https://github.com/python/cpython/issues/137477

   (89) https://github.com/python/cpython/issues/137044

   (90) https://github.com/python/cpython/issues/75989

   (91) https://github.com/python/cpython/issues/75989

   (92) https://github.com/python/cpython/issues/137017

   (93) https://github.com/python/cpython/issues/137273

   (94) https://github.com/python/cpython/issues/137239

   (95) https://github.com/python/cpython/issues/81325

   (96) https://github.com/python/cpython/issues/81325

   (97) https://github.com/python/cpython/issues/137185

   (98) https://github.com/python/cpython/issues/136914

   (99) https://github.com/python/cpython/issues/136912

   (100) https://github.com/python/cpython/issues/83424

   (101) https://github.com/python/cpython/issues/136234

   (102) https://github.com/python/cpython/issues/136507

   (103) https://github.com/python/cpython/issues/136057

   (104) https://github.com/python/cpython/issues/135386

   (105) https://github.com/python/cpython/issues/135444

   (106) https://github.com/python/cpython/issues/126631

   (107) https://github.com/python/cpython/issues/135307

   (108) https://github.com/python/cpython/issues/134453

   (109) https://github.com/python/cpython/issues/134698

   (110) https://github.com/python/cpython/issues/125996

   (111) https://github.com/python/cpython/issues/133789

   (112) https://github.com/python/cpython/issues/127081

   (113) https://github.com/python/cpython/issues/132551

   (114) https://github.com/python/cpython/issues/131788

   (115) https://github.com/python/cpython/issues/118981

   (116) https://github.com/python/cpython/issues/102431

   (117) https://github.com/python/cpython/issues/78319

   (118) https://bugs.python.org/issue?@action=redirect&bpo=38735

   (119) https://bugs.python.org/issue?@action=redirect&bpo=41839


File: python.info,  Node: IDLE<4>,  Next: Documentation<3>,  Prev: Library<4>,  Up: Python 3 14 1 final

1.24.3.6 IDLE
.............

   - gh-96491(1): Deduplicate version number in IDLE shell title bar
     after saving to a file.

   - gh-139742(2): Colorize t-string prefixes for template strings in
     IDLE, as done for f-string prefixes.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/96491

   (2) https://github.com/python/cpython/issues/139742


File: python.info,  Node: Documentation<3>,  Next: Core and Builtins<3>,  Prev: IDLE<4>,  Up: Python 3 14 1 final

1.24.3.7 Documentation
......................

   - gh-141994(1): *note xml.sax.handler: 130.: Make Documentation of
     *note xml.sax.handler.feature_external_ges: 17b5. warn of opening
     up to external entity attacks(2).  Patch by Sebastian Pipping.

   - gh-140578(3): Remove outdated sencence in the documentation for
     *note multiprocessing: 98, that implied that *note
     concurrent.futures.ThreadPoolExecutor: 94a. did not exist.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/141994

   (2) https://en.wikipedia.org/wiki/XML_external_entity_attack

   (3) https://github.com/python/cpython/issues/140578


File: python.info,  Node: Core and Builtins<3>,  Next: Library<5>,  Prev: Documentation<3>,  Up: Python 3 14 1 final

1.24.3.8 Core and Builtins
..........................

   - gh-142048(1): Fix quadratically increasing garbage collection
     delays in free-threaded build.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/142048


File: python.info,  Node: Library<5>,  Next: Core and Builtins<4>,  Prev: Core and Builtins<3>,  Up: Python 3 14 1 final

1.24.3.9 Library
................

   - gh-116738(1): Fix thread safety issue with *note re: be. scanner
     objects in free-threaded builds.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116738


File: python.info,  Node: Core and Builtins<4>,  Next: Library<6>,  Prev: Library<5>,  Up: Python 3 14 1 final

1.24.3.10 Core and Builtins
...........................

   - gh-141930(1): When importing a module, use Python’s regular file
     object to ensure that writes to ‘.pyc’ files are complete or an
     appropriate error is raised.

   - gh-120158(2): Fix inconsistent state when enabling or disabling
     monitoring events too many times.

   - gh-139653(3): Only raise a ‘RecursionError’ or trigger a fatal
     error if the stack pointer is both below the limit pointer 'and'
     above the stack base.  If outside of these bounds assume that it is
     OK. This prevents false positives when user-space threads swap
     stacks.

   - gh-139103(4): Improve multithreaded scaling of dataclasses on the
     free-threaded build.

   - gh-141579(5): Fix *note sys.activate_stack_trampoline(): 69b. to
     properly support the ‘perf_jit’ backend.  Patch by Pablo Galindo.

   - gh-114203(6): Skip locking if object is already locked by two-mutex
     critical section.

   - gh-141528(7): Suggest using *note
     concurrent.interpreters.Interpreter.close(): 17b9. instead of the
     private ‘_interpreters.destroy’ function when warning about
     remaining subinterpreters.  Patch by Sergey Miryanov.

   - gh-141312(8): Fix the assertion failure in the ‘__setstate__’
     method of the range iterator when a non-integer argument is passed.
     Patch by Sergey Miryanov.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/141930

   (2) https://github.com/python/cpython/issues/120158

   (3) https://github.com/python/cpython/issues/139653

   (4) https://github.com/python/cpython/issues/139103

   (5) https://github.com/python/cpython/issues/141579

   (6) https://github.com/python/cpython/issues/114203

   (7) https://github.com/python/cpython/issues/141528

   (8) https://github.com/python/cpython/issues/141312


File: python.info,  Node: Library<6>,  Next: Core and Builtins<5>,  Prev: Core and Builtins<4>,  Up: Python 3 14 1 final

1.24.3.11 Library
.................

   - gh-116738(1): Make csv module thread-safe on the *note free
     threaded: 1f4. build.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116738


File: python.info,  Node: Core and Builtins<5>,  Next: Library<7>,  Prev: Library<6>,  Up: Python 3 14 1 final

1.24.3.12 Core and Builtins
...........................

   - gh-140939(1): Fix memory leak when *note bytearray: 344. or *note
     bytes: 192. is formated with the ‘%*b’ format with a large width
     that results in a *note MemoryError: 1786.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/140939


File: python.info,  Node: Library<7>,  Next: Core and Builtins<6>,  Prev: Core and Builtins<5>,  Up: Python 3 14 1 final

1.24.3.13 Library
.................

   - gh-140260(1): Fix *note struct: db. data race in endian table
     initialization with subinterpreters.  Patch by Shamil Abdulaev.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/140260


File: python.info,  Node: Core and Builtins<6>,  Next: Library<8>,  Prev: Library<7>,  Up: Python 3 14 1 final

1.24.3.14 Core and Builtins
...........................

   - gh-140530(1): Fix a reference leak when ‘raise exc from cause’
     fails.  Patch by Bénédikt Tran.

   - gh-140373(2): Correctly emit ‘PY_UNWIND’ event when generator
     object is closed.  Patch by Mikhail Efimov.

   - gh-140576(3): Fixed crash in *note tokenize.generate_tokens(): 702.
     in case of specific incorrect input.  Patch by Mikhail Efimov.

   - gh-140551(4): Fixed crash in *note dict: 183. if *note
     dict.clear(): 17be. is called at the lookup stage.  Patch by
     Mikhail Efimov and Inada Naoki.

   - gh-140517(5): Fixed a reference leak when iterating over the result
     of *note map(): 19f. with ‘strict=True’ when the input iterables
     have different lengths.  Patch by Mikhail Efimov.

   - gh-140471(6): Fix potential buffer overflow in *note ast.AST: 4c4.
     node initialization when encountering malformed *note _fields:
     17bf. containing non-*note str: 169.

   - gh-140431(7): Fix a crash in Python’s *note garbage collector:
     17c0. due to partially initialized *note coroutine: 6ba. objects
     when coroutine origin tracking depth is enabled (*note
     sys.set_coroutine_origin_tracking_depth(): d87.).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/140530

   (2) https://github.com/python/cpython/issues/140373

   (3) https://github.com/python/cpython/issues/140576

   (4) https://github.com/python/cpython/issues/140551

   (5) https://github.com/python/cpython/issues/140517

   (6) https://github.com/python/cpython/issues/140471

   (7) https://github.com/python/cpython/issues/140431


File: python.info,  Node: Library<8>,  Next: Core and Builtins<7>,  Prev: Core and Builtins<6>,  Up: Python 3 14 1 final

1.24.3.15 Library
.................

   - gh-140398(1): Fix memory leaks in *note readline: bf. functions
     *note read_init_file(): 17c2, *note read_history_file(): 17c3,
     *note write_history_file(): 17c4, and *note append_history_file():
     1053. when *note PySys_Audit(): 613. fails.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/140398


File: python.info,  Node: Core and Builtins<7>,  Next: Library<9>,  Prev: Library<8>,  Up: Python 3 14 1 final

1.24.3.16 Core and Builtins
...........................

   - gh-140406(1): Fix memory leak when an object’s *note __hash__():
     cf5. method returns an object that isn’t an *note int: 19b.

   - gh-140358(2): Restore elapsed time and unreachable object count in
     GC debug output.  These were inadvertently removed during a
     refactor of ‘gc.c’.  The debug log now again reports elapsed
     collection time and the number of unreachable objects.  Contributed
     by Pål Grønås Drange.

   - gh-140306(3): Fix memory leaks in cross-interpreter channel
     operations and shared namespace handling.

   - gh-140301(4): Fix memory leak of ‘PyConfig’ in subinterpreters.

   - gh-140257(5): Fix data race between interpreter_clear() and
     take_gil() on eval_breaker during finalization with daemon threads.

   - gh-139951(6): Fixes a regression in GC performance for a growing
     heap composed mostly of small tuples.

        * Counts number of actually tracked objects, instead of
          trackable objects.  This ensures that untracking tuples has
          the desired effect of reducing GC overhead.

        * Does not track most untrackable tuples during creation.  This
          prevents large numbers of small tuples causing excessive GCs.

   - gh-140104(7): Fix a bug with exception handling in the JIT. Patch
     by Ken Jin.  Bug reported by Daniel Diniz.

   - gh-140061(8): Fixing the checking of whether an object is uniquely
     referenced to ensure free-threaded compatibility.  Patch by Sergey
     Miryanov.

   - gh-140067(9): Fix memory leak in sub-interpreter creation.

   - gh-140000(10): Fix potential memory leak when a reference cycle
     exists between an instance of *note typing.TypeAliasType: 2ae,
     *note typing.TypeVar: 487, *note typing.ParamSpec: 488, or *note
     typing.TypeVarTuple: 489. and its ‘__name__’ attribute.  Patch by
     Mikhail Efimov.

   - gh-139914(11): Restore support for HP PA-RISC, which has an
     upwards-growing stack.

   - gh-139988(12): Fix a memory leak when failing to create a *note
     Union: 2a8. type.  Patch by Bénédikt Tran.

   - gh-139748(13): Fix reference leaks in error branches of functions
     accepting path strings or bytes such as *note compile(): 4b2. and
     *note os.system(): 1664.  Patch by Bénédikt Tran.

   - gh-139516(14): Fix lambda colon erroneously start format spec in
     f-string in tokenizer.

   - gh-139640(15): *note ast.parse(): 1c2. no longer emits syntax
     warnings for ‘return’/‘break’/‘continue’ in ‘finally’ (see PEP
     765(16)) – they are only emitted during compilation.

   - gh-139640(17): Fix swallowing some syntax warnings in different
     modules if they accidentally have the same message and are emitted
     from the same line.  Fix duplicated warnings in the ‘finally’
     block.

   - gh-63161(18): Support non-UTF-8 shebang and comments in Python
     source files if non-UTF-8 encoding is specified.  Detect decoding
     error in comments for default (UTF-8) encoding.  Show the line and
     position of decoding error for default encoding in a traceback.
     Show the line containing the coding cookie when it conflicts with
     the BOM in a traceback.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/140406

   (2) https://github.com/python/cpython/issues/140358

   (3) https://github.com/python/cpython/issues/140306

   (4) https://github.com/python/cpython/issues/140301

   (5) https://github.com/python/cpython/issues/140257

   (6) https://github.com/python/cpython/issues/139951

   (7) https://github.com/python/cpython/issues/140104

   (8) https://github.com/python/cpython/issues/140061

   (9) https://github.com/python/cpython/issues/140067

   (10) https://github.com/python/cpython/issues/140000

   (11) https://github.com/python/cpython/issues/139914

   (12) https://github.com/python/cpython/issues/139988

   (13) https://github.com/python/cpython/issues/139748

   (14) https://github.com/python/cpython/issues/139516

   (15) https://github.com/python/cpython/issues/139640

   (16) https://peps.python.org/pep-0765/

   (17) https://github.com/python/cpython/issues/139640

   (18) https://github.com/python/cpython/issues/63161


File: python.info,  Node: Library<9>,  Next: Core and Builtins<8>,  Prev: Core and Builtins<7>,  Up: Python 3 14 1 final

1.24.3.17 Library
.................

   - gh-116738(1): Make *note mmap: 94. thread-safe on the *note free
     threaded: 1f4. build.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116738


File: python.info,  Node: Core and Builtins<8>,  Next: Library<10>,  Prev: Library<9>,  Up: Python 3 14 1 final

1.24.3.18 Core and Builtins
...........................

   - gh-138558(1): Fix handling of unusual t-string annotations in
     annotationlib.  Patch by Dave Peck.

   - gh-134466(2): Don’t run PyREPL in a degraded environment where
     setting termios attributes is not allowed.

   - gh-138944(3): Fix *note SyntaxError: 18e. message when invalid
     syntax appears on the same line as a valid ‘import ... as ...’ or
     ‘from ... import ... as ...’ statement.  Patch by Brian Schubert.

   - gh-105487(4): Remove non-existent *note __copy__(): 17c8, *note
     __deepcopy__(): 17c9, and *note __bases__: 16b3. from the *note
     __dir__(): 17ca. entries of *note types.GenericAlias: 9ee.

   - gh-69605(5): Fix some standard library submodules missing from the
     *note REPL: 492. auto-completion of imports.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/138558

   (2) https://github.com/python/cpython/issues/134466

   (3) https://github.com/python/cpython/issues/138944

   (4) https://github.com/python/cpython/issues/105487

   (5) https://github.com/python/cpython/issues/69605


File: python.info,  Node: Library<10>,  Next: Core and Builtins<9>,  Prev: Core and Builtins<8>,  Up: Python 3 14 1 final

1.24.3.19 Library
.................

   - gh-116738(1): Make *note cProfile: 2b. thread-safe on the *note
     free threaded: 1f4. build.

   - gh-138004(2): On Solaris/Illumos platforms, thread names are now
     encoded as ASCII to avoid errors on systems (e.g.  OpenIndiana)
     that don’t support non-ASCII names.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116738

   (2) https://github.com/python/cpython/issues/138004


File: python.info,  Node: Core and Builtins<9>,  Next: C API<2>,  Prev: Library<10>,  Up: Python 3 14 1 final

1.24.3.20 Core and Builtins
...........................

   - gh-137433(1): Fix a potential deadlock in the *note free threading:
     1f4. build when daemon threads enable or disable profiling or
     tracing while the main thread is shutting down the interpreter.

   - gh-137400(2): Fix a crash in the *note free threading: 1f4. build
     when disabling profiling or tracing across all threads with *note
     PyEval_SetProfileAllThreads(): 782. or *note
     PyEval_SetTraceAllThreads(): 664. or their Python equivalents *note
     threading.settrace_all_threads(): 6f0. and *note
     threading.setprofile_all_threads(): 6f1.

   - gh-58124(3): Fix name of the Python encoding in Unicode errors of
     the code page codec: use «cp65000» and «cp65001» instead of
     «CP_UTF7» and «CP_UTF8» which are not valid Python code names.
     Patch by Victor Stinner.

   - gh-132657(4): Improve performance of *note frozenset: 7f3. by
     removing locks in the free-threading build.

   - gh-133400(5): Fixed Ctrl+D (^D) behavior in _pyrepl module to match
     old pre-3.13 REPL behavior.

   - gh-128640(6): Fix a crash when using threads inside of a
     subinterpreter.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/137433

   (2) https://github.com/python/cpython/issues/137400

   (3) https://github.com/python/cpython/issues/58124

   (4) https://github.com/python/cpython/issues/132657

   (5) https://github.com/python/cpython/issues/133400

   (6) https://github.com/python/cpython/issues/128640


File: python.info,  Node: C API<2>,  Next: Build<2>,  Prev: Core and Builtins<9>,  Up: Python 3 14 1 final

1.24.3.21 C API
...............

   - gh-137422(1): Fix *note free threading: 1f4. race condition in
     *note PyImport_AddModuleRef(): 5fb.  It was previously possible for
     two calls to the function return two different objects, only one of
     which was stored in *note sys.modules: 17ce.

   - gh-140042(2): Removed the sqlite3_shutdown call that could cause
     closing connections for sqlite when used with multiple sub
     interpreters.

   - gh-141042(3): Make qNaN in *note PyFloat_Pack2(): 96a. and *note
     PyFloat_Pack4(): 96b, if while conversion to a narrower precision
     floating-point format — the remaining after truncation payload will
     be zero.  Patch by Sergey B Kirpichev.

   - gh-140487(4): Fix *note Py_RETURN_NOTIMPLEMENTED: 17cf. in limited
     C API 3.11 and older: don’t treat ‘Py_NotImplemented’ as immortal.
     Patch by Victor Stinner.

   - gh-140153(5): Fix *note Py_REFCNT(): 2cf. definition on limited C
     API 3.11-3.13.  Patch by Victor Stinner.

   - gh-139653(6): Add *note
     PyUnstable_ThreadState_SetStackProtection(): 466. and *note
     PyUnstable_ThreadState_ResetStackProtection(): 467. functions to
     set the stack protection base address and stack protection size of
     a Python thread state.  Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/137422

   (2) https://github.com/python/cpython/issues/140042

   (3) https://github.com/python/cpython/issues/141042

   (4) https://github.com/python/cpython/issues/140487

   (5) https://github.com/python/cpython/issues/140153

   (6) https://github.com/python/cpython/issues/139653


File: python.info,  Node: Build<2>,  Prev: C API<2>,  Up: Python 3 14 1 final

1.24.3.22 Build
...............

   - gh-141808(1): Do not generate the jit stencils twice in case of PGO
     builds on Windows.

   - gh-141784(2): Fix ‘_remote_debugging_module.c’ compilation on
     32-bit Linux.  Include Python.h before system headers to make sure
     that ‘_remote_debugging_module.c’ uses the same types (ABI) than
     Python.  Patch by Victor Stinner.

   - gh-140768(3): Warn when the WASI SDK version doesn’t match what’s
     supported.

   - gh-140513(4): Generate a clear compilation error when
     ‘_Py_TAIL_CALL_INTERP’ is enabled but either ‘preserve_none’ or
     ‘musttail’ is not supported.

   - gh-140189(5): iOS builds were added to CI.

   - gh-138489(6): When cross-compiling for WASI by ‘build_wasm’ or
     ‘build_emscripten’, the ‘build-details.json’ step is now included
     in the build process, just like with native builds.

     This fixes the ‘libinstall’ task which requires the
     ‘build-details.json’ file during the process.

   - gh-137618(7): ‘PYTHON_FOR_REGEN’ now requires Python 3.10 to Python
     3.15.  Patch by Adam Turner.

   - gh-123681(8): Check the ‘strftime()’ behavior at runtime instead of
     at the compile time to support cross-compiling.  Remove the
     internal macro ‘_Py_NORMALIZE_CENTURY’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/141808

   (2) https://github.com/python/cpython/issues/141784

   (3) https://github.com/python/cpython/issues/140768

   (4) https://github.com/python/cpython/issues/140513

   (5) https://github.com/python/cpython/issues/140189

   (6) https://github.com/python/cpython/issues/138489

   (7) https://github.com/python/cpython/issues/137618

   (8) https://github.com/python/cpython/issues/123681


File: python.info,  Node: Python 3 14 0 final,  Next: Python 3 14 0 release candidate 3,  Prev: Python 3 14 1 final,  Up: Changelog

1.24.4 Python 3.14.0 final
--------------------------

'Release date: 2025-10-07'

* Menu:

* macOS::
* Windows: Windows<3>.
* Tools/Demos: Tools/Demos<3>.
* Security: Security<4>.
* Library: Library<11>.


File: python.info,  Node: macOS,  Next: Windows<3>,  Up: Python 3 14 0 final

1.24.4.1 macOS
..............

   - gh-124111(1): Update macOS installer to use Tcl/Tk 8.6.17.

   - gh-139573(2): Updated bundled version of OpenSSL to 3.0.18.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/124111

   (2) https://github.com/python/cpython/issues/139573


File: python.info,  Node: Windows<3>,  Next: Tools/Demos<3>,  Prev: macOS,  Up: Python 3 14 0 final

1.24.4.2 Windows
................

   - gh-139573(1): Updated bundled version of OpenSSL to 3.0.18.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/139573


File: python.info,  Node: Tools/Demos<3>,  Next: Security<4>,  Prev: Windows<3>,  Up: Python 3 14 0 final

1.24.4.3 Tools/Demos
....................

   - gh-139330(1): SBOM generation tool didn’t cross-check the version
     and checksum values against the ‘Modules/expat/refresh.sh’ script,
     leading to the values becoming out-of-date during routine updates.

   - gh-132006(2): XCframeworks now include privacy manifests to satisfy
     Apple App Store submission requirements.

   - gh-138171(3): A script for building an iOS XCframework was added.
     As part of this change, the top level ‘iOS’ folder has been moved
     to be a subdirectory of the ‘Apple’ folder.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/139330

   (2) https://github.com/python/cpython/issues/132006

   (3) https://github.com/python/cpython/issues/138171


File: python.info,  Node: Security<4>,  Next: Library<11>,  Prev: Tools/Demos<3>,  Up: Python 3 14 0 final

1.24.4.4 Security
.................

   - gh-139400(1): *note xml.parsers.expat: 12c.: Make sure that parent
     Expat parsers are only garbage-collected once they are no longer
     referenced by subparsers created by *note
     ExternalEntityParserCreate(): 17d6.  Patch by Sebastian Pipping.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/139400


File: python.info,  Node: Library<11>,  Prev: Security<4>,  Up: Python 3 14 0 final

1.24.4.5 Library
................

   - gh-139312(1): Upgrade bundled libexpat to 2.7.3

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/139312


File: python.info,  Node: Python 3 14 0 release candidate 3,  Next: Python 3 14 0 release candidate 2,  Prev: Python 3 14 0 final,  Up: Changelog

1.24.5 Python 3.14.0 release candidate 3
----------------------------------------

'Release date: 2025-09-18'

* Menu:

* Windows: Windows<4>.
* Tools/Demos: Tools/Demos<4>.
* Security: Security<5>.
* Library: Library<12>.
* Core and Builtins: Core and Builtins<10>.


File: python.info,  Node: Windows<4>,  Next: Tools/Demos<4>,  Up: Python 3 14 0 release candidate 3

1.24.5.1 Windows
................

   - gh-138896(1): Fix error installing C runtime on non-updated Windows
     machines

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/138896


File: python.info,  Node: Tools/Demos<4>,  Next: Security<5>,  Prev: Windows<4>,  Up: Python 3 14 0 release candidate 3

1.24.5.2 Tools/Demos
....................

   - gh-137873(1): The iOS test runner has been simplified, resolving
     some issues that have been observed using the runner in GitHub
     Actions and Azure Pipelines test environments.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/137873


File: python.info,  Node: Security<5>,  Next: Library<12>,  Prev: Tools/Demos<4>,  Up: Python 3 14 0 release candidate 3

1.24.5.3 Security
.................

   - gh-135661(1): Fix CDATA section parsing in *note
     html.parser.HTMLParser: a79. according to the HTML5 standard: ‘]
     ]>’ and ‘]] >’ no longer end the CDATA section.  Add private method
     ‘_set_support_cdata()’ which can be used to specify how to parse
     ‘<[CDATA[’ — as a CDATA section in foreign content (SVG or MathML)
     or as a bogus comment in the HTML namespace.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135661


File: python.info,  Node: Library<12>,  Next: Core and Builtins<10>,  Prev: Security<5>,  Up: Python 3 14 0 release candidate 3

1.24.5.4 Library
................

   - gh-138998(1): Update bundled libexpat to 2.7.2

   - gh-118803(2): Add back *note collections.abc.ByteString: 342. and
     *note typing.ByteString: 345.  Both had been removed in prior
     alpha, beta and release candidates for Python 3.14, but their
     removal has now been postponed to Python 3.17.

   - gh-137226(3): Fix *note typing.get_type_hints(): 8c1. calls on
     generic *note typing.TypedDict: 332. classes defined with string
     annotations.

   - gh-138804(4): Raise *note TypeError: 198. instead of *note
     AttributeError: 5f0. when an argument of incorrect type is passed
     to *note shlex.quote(): 582.  This restores the behavior of the
     function prior to 3.14.

   - gh-128636(5): Fix crash in PyREPL when os.environ is overwritten
     with an invalid value for mac

   - gh-138514(6): Raise *note ValueError: 2ec. when a multi-character
     string is passed to the 'echo_char' parameter of *note
     getpass.getpass(): 21d.  Patch by Benjamin Johnson.

   - gh-138515(7): *note email: 3f. is added to Emscripten build.

   - gh-99948(8): *note ctypes.util.find_library(): f47. now works in
     Emscripten build.

   - gh-138253(9): Add the 'block' parameter in the ‘put()’ and ‘get()’
     methods of the *note concurrent.interpreters: 25. queues for
     compatibility with the *note queue.Queue: 159c. interface.

   - gh-138133(10): Prevent infinite traceback loop when sending CTRL^C
     to Python through ‘strace’.

   - gh-134869(11): Fix an issue where pressing Ctrl+C during tab
     completion in the REPL would leave the autocompletion menu in a
     corrupted state.

   - gh-90548(12): Fix ‘musl’ detection for *note platform.libc_ver():
     17dd. on Alpine Linux if compiled with –strip-all.

   - gh-136134(13): ‘SMTP.auth_cram_md5()’ now raises an *note
     SMTPException: 11a3. instead of a *note ValueError: 2ec. if Python
     has been built without MD5 support.  In particular, *note SMTP:
     b29. clients will not attempt to use this method even if the remote
     server is assumed to support it.  Patch by Bénédikt Tran.

   - gh-136134(14): *note IMAP4.login_cram_md5: 17de. now raises an
     *note IMAP4.error: 17df. if CRAM-MD5 authentication is not
     supported.  Patch by Bénédikt Tran.

   - gh-134953(15): Expand ‘_colorize’ theme with ‘keyword_constant’ and
     implement in *note repl: 492.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/138998

   (2) https://github.com/python/cpython/issues/118803

   (3) https://github.com/python/cpython/issues/137226

   (4) https://github.com/python/cpython/issues/138804

   (5) https://github.com/python/cpython/issues/128636

   (6) https://github.com/python/cpython/issues/138514

   (7) https://github.com/python/cpython/issues/138515

   (8) https://github.com/python/cpython/issues/99948

   (9) https://github.com/python/cpython/issues/138253

   (10) https://github.com/python/cpython/issues/138133

   (11) https://github.com/python/cpython/issues/134869

   (12) https://github.com/python/cpython/issues/90548

   (13) https://github.com/python/cpython/issues/136134

   (14) https://github.com/python/cpython/issues/136134

   (15) https://github.com/python/cpython/issues/134953


File: python.info,  Node: Core and Builtins<10>,  Prev: Library<12>,  Up: Python 3 14 0 release candidate 3

1.24.5.5 Core and Builtins
..........................

   - gh-71810(1): Raise *note OverflowError: a83. for ‘(-1).to_bytes()’
     for signed conversions when bytes count is zero.  Patch by Sergey B
     Kirpichev.

   - gh-138192(2): Fix *note contextvars: 28. initialization so that all
     subinterpreters are assigned the *note MISSING: 17e1. value.

   - gh-138479(3): Fix a crash when a generic object’s
     ‘__typing_subst__’ returns an object that isn’t a *note tuple: 614.

   - gh-138372(4): Fix *note SyntaxWarning: 1ae. emitted for erroneous
     subscript expressions involving *note template string literals:
     17e2.  Patch by Brian Schubert.

   - gh-138318(5): The default REPL now avoids highlighting built-in
     names (for instance *note set: 184. or *note format(): 199.) when
     they are used as attribute names (for instance in ‘value.set’ or
     ‘text.format’).

   - gh-138349(6): Fix crash in certain cases where a module contains
     both a module-level annotation and a comprehension.

   - gh-137384(7): Fix a crash when using the *note warnings: 118.
     module in a finalizer at shutdown.  Patch by Kumar Aditya.

   - gh-137883(8): Fix runaway recursion when calling a function with
     keyword arguments.

   - gh-137079(9): Fix keyword typo recognition when parsing files.
     Patch by Pablo Galindo.

   - gh-137728(10): Fix the JIT’s handling of many local variables.
     This previously caused a segfault.

   - gh-137576(11): Fix for incorrect source code being shown in
     tracebacks from the Basic REPL when *note PYTHONSTARTUP: 1b8. is
     given.  Patch by Adam Hartz.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/71810

   (2) https://github.com/python/cpython/issues/138192

   (3) https://github.com/python/cpython/issues/138479

   (4) https://github.com/python/cpython/issues/138372

   (5) https://github.com/python/cpython/issues/138318

   (6) https://github.com/python/cpython/issues/138349

   (7) https://github.com/python/cpython/issues/137384

   (8) https://github.com/python/cpython/issues/137883

   (9) https://github.com/python/cpython/issues/137079

   (10) https://github.com/python/cpython/issues/137728

   (11) https://github.com/python/cpython/issues/137576


File: python.info,  Node: Python 3 14 0 release candidate 2,  Next: Python 3 14 0 release candidate 1,  Prev: Python 3 14 0 release candidate 3,  Up: Changelog

1.24.6 Python 3.14.0 release candidate 2
----------------------------------------

'Release date: 2025-08-14'

* Menu:

* macOS: macOS<2>.
* Windows: Windows<5>.
* Library: Library<13>.
* Documentation: Documentation<4>.
* Core and Builtins: Core and Builtins<11>.
* C API: C API<3>.
* Build: Build<3>.


File: python.info,  Node: macOS<2>,  Next: Windows<5>,  Up: Python 3 14 0 release candidate 2

1.24.6.1 macOS
..............

   - gh-137450(1): macOS installer shell path management improvements:
     separate the installer ‘Shell profile updater’ postinstall script
     from the ‘Update Shell Profile.command’ to enable more robust error
     handling.

   - gh-137134(2): Update macOS installer to ship with SQLite version
     3.50.4.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/137450

   (2) https://github.com/python/cpython/issues/137134


File: python.info,  Node: Windows<5>,  Next: Library<13>,  Prev: macOS<2>,  Up: Python 3 14 0 release candidate 2

1.24.6.2 Windows
................

   - gh-137134(1): Update Windows installer to ship with SQLite 3.50.4.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/137134


File: python.info,  Node: Library<13>,  Next: Documentation<4>,  Prev: Windows<5>,  Up: Python 3 14 0 release candidate 2

1.24.6.3 Library
................

   - gh-137426(1): Remove the code deprecation of
     ‘importlib.abc.ResourceLoader’.  It is documented as deprecated,
     but left for backwards compatibility with other classes in
     ‘importlib.abc’.

   - gh-137282(2): Fix tab completion and *note dir(): 845. on *note
     concurrent.futures: 24.

   - gh-137257(3): Bump the version of pip bundled in ensurepip to
     version 25.2

   - gh-137226(4): Fix behavior of *note
     annotationlib.ForwardRef.evaluate(): 179a. when the 'type_params'
     parameter is passed and the name of a type param is also present in
     an enclosing scope.

   - gh-130522(5): Fix unraisable *note TypeError: 198. raised during
     *note interpreter shutdown: 47a. in the *note threading: f3.
     module.

   - gh-137059(6): Fix handling of file URLs with a Windows drive letter
     in the URL authority by *note urllib.request.url2pathname(): 2bd.
     This fixes a regression in earlier pre-releases of Python 3.14.

   - gh-130577(7): *note tarfile: e4. now validates archives to ensure
     member offsets are non-negative.  (Contributed by Alexander Enrique
     Urieles Nieto in gh-130577(8).)

   - gh-135228(9): When *note dataclasses: 33. replaces a class with a
     slotted dataclass, the original class can now be garbage collected
     again.  Earlier changes in Python 3.14 caused this class to always
     remain in existence together with the replacement class synthesized
     by *note dataclasses: 33.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/137426

   (2) https://github.com/python/cpython/issues/137282

   (3) https://github.com/python/cpython/issues/137257

   (4) https://github.com/python/cpython/issues/137226

   (5) https://github.com/python/cpython/issues/130522

   (6) https://github.com/python/cpython/issues/137059

   (7) https://github.com/python/cpython/issues/130577

   (8) https://github.com/python/cpython/issues/130577

   (9) https://github.com/python/cpython/issues/135228


File: python.info,  Node: Documentation<4>,  Next: Core and Builtins<11>,  Prev: Library<13>,  Up: Python 3 14 0 release candidate 2

1.24.6.4 Documentation
......................

   - gh-136155(1): We are now checking for fatal errors in EPUB builds
     in CI.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/136155


File: python.info,  Node: Core and Builtins<11>,  Next: C API<3>,  Prev: Documentation<4>,  Up: Python 3 14 0 release candidate 2

1.24.6.5 Core and Builtins
..........................

   - gh-137400(1): Fix a crash in the *note free threading: 1f4. build
     when disabling profiling or tracing across all threads with *note
     PyEval_SetProfileAllThreads(): 782. or *note
     PyEval_SetTraceAllThreads(): 664. or their Python equivalents *note
     threading.settrace_all_threads(): 6f0. and *note
     threading.setprofile_all_threads(): 6f1.

   - gh-137314(2): Fixed a regression where raw f-strings incorrectly
     interpreted escape sequences in format specifications.  Raw
     f-strings now properly preserve literal backslashes in format
     specs, matching the behavior from Python 3.11.  For example,
     ‘rf"{obj:\xFF}"’ now correctly produces ‘'\\xFF'’ instead of ‘'ÿ'’.
     Patch by Pablo Galindo.

   - gh-137308(3): A standalone docstring in a node body is optimized as
     a *note pass: 17e. statement to ensure that the node’s body is
     never empty.  There was a *note ValueError: 2ec. in *note
     compile(): 4b2. otherwise.

   - gh-137288(4): Fix bug where some bytecode instructions of a boolean
     expression are not associated with the correct exception handler.

   - gh-134291(5): Remove some newer macOS API usage from the JIT
     compiler in order to restore compatibility with older OSX 10.15
     deployment targets.

   - gh-131338(6): Disable computed stack limit checks on non-glibc
     linux platforms to fix crashes on deep recursion.

   - gh-136870(7): Fix data races while de-instrumenting bytecode of
     code objects running concurrently in threads.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/137400

   (2) https://github.com/python/cpython/issues/137314

   (3) https://github.com/python/cpython/issues/137308

   (4) https://github.com/python/cpython/issues/137288

   (5) https://github.com/python/cpython/issues/134291

   (6) https://github.com/python/cpython/issues/131338

   (7) https://github.com/python/cpython/issues/136870


File: python.info,  Node: C API<3>,  Next: Build<3>,  Prev: Core and Builtins<11>,  Up: Python 3 14 0 release candidate 2

1.24.6.6 C API
..............

   - gh-137573(1): Mark ‘_PyOptimizer_Optimize’ as *note Py_NO_INLINE:
     17ea. to prevent stack overflow crashes on macOS.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/137573


File: python.info,  Node: Build<3>,  Prev: C API<3>,  Up: Python 3 14 0 release candidate 2

1.24.6.7 Build
..............

   - gh-132339(1): Add support for OpenSSL 3.5.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132339


File: python.info,  Node: Python 3 14 0 release candidate 1,  Next: Python 3 14 0 beta 4,  Prev: Python 3 14 0 release candidate 2,  Up: Changelog

1.24.7 Python 3.14.0 release candidate 1
----------------------------------------

'Release date: 2025-07-22'

* Menu:

* Tools/Demos: Tools/Demos<5>.
* Security: Security<6>.
* Library: Library<14>.
* Core and Builtins: Core and Builtins<12>.
* Library: Library<15>.
* Core and Builtins: Core and Builtins<13>.
* Library: Library<16>.
* Core and Builtins: Core and Builtins<14>.
* C API: C API<4>.
* Build: Build<4>.


File: python.info,  Node: Tools/Demos<5>,  Next: Security<6>,  Up: Python 3 14 0 release candidate 1

1.24.7.1 Tools/Demos
....................

   - gh-136251(1): Fixes and usability improvements for
     ‘Tools/wasm/emscripten/web_example’

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/136251


File: python.info,  Node: Security<6>,  Next: Library<14>,  Prev: Tools/Demos<5>,  Up: Python 3 14 0 release candidate 1

1.24.7.2 Security
.................

   - gh-135661(1): Fix parsing attributes with whitespaces around the
     ‘=’ separator in *note html.parser.HTMLParser: a79. according to
     the HTML5 standard.

   - gh-118350(2): Fix support of escapable raw text mode (elements
     «textarea» and «title») in *note html.parser.HTMLParser: a79.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135661

   (2) https://github.com/python/cpython/issues/118350


File: python.info,  Node: Library<14>,  Next: Core and Builtins<12>,  Prev: Security<6>,  Up: Python 3 14 0 release candidate 1

1.24.7.3 Library
................

   - gh-136170(1): Removed the unreleased ‘zipfile.ZipFile.data_offset’
     property added in 3.14.0a7 as it wasn’t fully clear which behavior
     it should have in some situations so the result was not always what
     a user might expect.

   - gh-124621(2): pyrepl now works in Emscripten.

   - gh-136874(3): Discard URL query and fragment in *note
     urllib.request.url2pathname(): 2bd.

   - gh-130645(4): Enable color help by default in *note argparse: 7.

   - gh-136549(5): Fix signature of *note threading.excepthook(): a4d.

   - gh-136523(6): Fix *note wave.Wave_write: 337. emitting an
     unraisable when open raises.

   - gh-52876(7): Add missing ‘keepends’ (default ‘True’) parameter to
     ‘codecs.StreamReaderWriter.readline()’ and
     ‘codecs.StreamReaderWriter.readlines()’.

   - gh-136470(8): Correct *note
     concurrent.futures.InterpreterPoolExecutor: 1d2.’s default thread
     name.

   - gh-136476(9): Fix a bug that was causing the
     ‘get_async_stack_trace’ function to miss some frames in the stack
     trace.

   - gh-136434(10): Fix docs generation of ‘UnboundItem’ in *note
     concurrent.interpreters: 25. when running with *note -OO: fb7.

   - gh-136380(11): Raises *note AttributeError: 5f0. when accessing
     *note concurrent.futures.InterpreterPoolExecutor: 1d2. and
     subinterpreters are not available.

   - gh-134759(12): Fix *note UnboundLocalError: 173d. in *note
     email.message.Message.get_payload(): 13d5. when the payload to
     decode is a *note bytes: 192. object.  Patch by Kliment Lamonov.

   - gh-134657(13): *note asyncio: b.: Remove some private names from
     ‘asyncio.__all__’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/136170

   (2) https://github.com/python/cpython/issues/124621

   (3) https://github.com/python/cpython/issues/136874

   (4) https://github.com/python/cpython/issues/130645

   (5) https://github.com/python/cpython/issues/136549

   (6) https://github.com/python/cpython/issues/136523

   (7) https://github.com/python/cpython/issues/52876

   (8) https://github.com/python/cpython/issues/136470

   (9) https://github.com/python/cpython/issues/136476

   (10) https://github.com/python/cpython/issues/136434

   (11) https://github.com/python/cpython/issues/136380

   (12) https://github.com/python/cpython/issues/134759

   (13) https://github.com/python/cpython/issues/134657


File: python.info,  Node: Core and Builtins<12>,  Next: Library<15>,  Prev: Library<14>,  Up: Python 3 14 0 release candidate 1

1.24.7.4 Core and Builtins
..........................

   - gh-136801(1): Fix PyREPL syntax highlighting on match cases after
     multi-line case.  Contributed by Olga Matoula.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/136801


File: python.info,  Node: Library<15>,  Next: Core and Builtins<13>,  Prev: Core and Builtins<12>,  Up: Python 3 14 0 release candidate 1

1.24.7.5 Library
................

   - gh-136421(1): Fix crash when initializing *note datetime: 34.
     concurrently.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/136421


File: python.info,  Node: Core and Builtins<13>,  Next: Library<16>,  Prev: Library<15>,  Up: Python 3 14 0 release candidate 1

1.24.7.6 Core and Builtins
..........................

   - gh-136541(1): Fix some issues with the perf trampolines on x86-64
     and aarch64.  The trampolines were not being generated correctly
     for some cases, which could lead to the perf integration not
     working correctly.  Patch by Pablo Galindo.

   - gh-136517(2): Fixed a typo that prevented printing of uncollectable
     objects when the *note gc.DEBUG_UNCOLLECTABLE: 13ca. mode was set.

   - gh-136525(3): Fix issue where per-thread bytecode was not
     instrumented for newly created threads.

   - gh-132661(4): ‘Interpolation.expression’ now has a default, the
     empty string.

   - gh-132661(5): Reflect recent PEP 750(6) change.

     Disallow concatenation of ‘string.templatelib.Template’ and *note
     str: 169.  Also, disallow implicit concatenation of t-string
     literals with string or f-string literals.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/136541

   (2) https://github.com/python/cpython/issues/136517

   (3) https://github.com/python/cpython/issues/136525

   (4) https://github.com/python/cpython/issues/132661

   (5) https://github.com/python/cpython/issues/132661

   (6) https://peps.python.org/pep-0750/


File: python.info,  Node: Library<16>,  Next: Core and Builtins<14>,  Prev: Core and Builtins<13>,  Up: Python 3 14 0 release candidate 1

1.24.7.7 Library
................

   - gh-116738(1): Make functions in *note grp: 6a. thread-safe on the
     *note free threaded: 1f4. build.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116738


File: python.info,  Node: Core and Builtins<14>,  Next: C API<4>,  Prev: Library<16>,  Up: Python 3 14 0 release candidate 1

1.24.7.8 Core and Builtins
..........................

   - gh-135148(1): Fixed a bug where f-string debug expressions (using
     =) would incorrectly strip out parts of strings containing escaped
     quotes and # characters.  Patch by Pablo Galindo.

   - gh-133136(2): Limit excess memory usage in the *note free
     threading: 1f4. build when a large dictionary or list is resized
     and accessed by multiple threads.

   - gh-91153(3): Fix a crash when a *note bytearray: 344. is
     concurrently mutated during item assignment.

   - gh-127971(4): Fix off-by-one read beyond the end of a string in
     string search.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135148

   (2) https://github.com/python/cpython/issues/133136

   (3) https://github.com/python/cpython/issues/91153

   (4) https://github.com/python/cpython/issues/127971


File: python.info,  Node: C API<4>,  Next: Build<4>,  Prev: Core and Builtins<14>,  Up: Python 3 14 0 release candidate 1

1.24.7.9 C API
..............

   - gh-112068(1): Revert support of nullable arguments in *note
     PyArg_Parse(): 17f6.

   - gh-133296(2): New variants for the critical section API that accept
     one or two *note PyMutex: 485. pointers rather than *note PyObject:
     5df. instances are now public in the non-limited C API.

   - gh-134009(3): Expose *note PyMutex_IsLocked(): 463. as part of the
     public C API.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/112068

   (2) https://github.com/python/cpython/issues/133296

   (3) https://github.com/python/cpython/issues/134009


File: python.info,  Node: Build<4>,  Prev: C API<4>,  Up: Python 3 14 0 release candidate 1

1.24.7.10 Build
...............

   - gh-135621(1): PyREPL no longer depends on the *note curses: 2f.
     standard library.  Contributed by Łukasz Langa.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135621


File: python.info,  Node: Python 3 14 0 beta 4,  Next: Python 3 14 0 beta 3,  Prev: Python 3 14 0 release candidate 1,  Up: Changelog

1.24.8 Python 3.14.0 beta 4
---------------------------

'Release date: 2025-07-08'

* Menu:

* Tools/Demos: Tools/Demos<6>.
* Tests: Tests<3>.
* Security: Security<7>.
* Library: Library<17>.
* Documentation: Documentation<5>.
* Core and Builtins: Core and Builtins<15>.
* C API: C API<5>.
* Build: Build<5>.


File: python.info,  Node: Tools/Demos<6>,  Next: Tests<3>,  Up: Python 3 14 0 beta 4

1.24.8.1 Tools/Demos
....................

   - gh-135968(1): Stubs for ‘strip’ are now provided as part of an iOS
     install.

   - gh-133600(2): Backport file reorganization for Tools/wasm/wasi.

     This should make backporting future code changes easier.  It also
     simplifies instructions around how to do WASI builds in the
     devguide.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135968

   (2) https://github.com/python/cpython/issues/133600


File: python.info,  Node: Tests<3>,  Next: Security<7>,  Prev: Tools/Demos<6>,  Up: Python 3 14 0 beta 4

1.24.8.2 Tests
..............

   - gh-135966(1): The iOS testbed now handles the ‘app_packages’ folder
     as a site directory.

   - gh-135494(2): Fix regrtest to support excluding tests from ‘--pgo’
     tests.  Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135966

   (2) https://github.com/python/cpython/issues/135494


File: python.info,  Node: Security<7>,  Next: Library<17>,  Prev: Tests<3>,  Up: Python 3 14 0 beta 4

1.24.8.3 Security
.................

   - gh-136053(1): *note marshal: 91.: fix a possible crash when
     deserializing *note slice: 695. objects.

   - gh-135661(2): Fix parsing start and end tags in *note
     html.parser.HTMLParser: a79. according to the HTML5 standard.

        * Whitespaces no longer accepted between ‘</’ and the tag name.
          E.g.  ‘</ script>’ does not end the script section.

        * Vertical tabulation (‘\v’) and non-ASCII whitespaces no longer
          recognized as whitespaces.  The only whitespaces are
          ‘\t\n\r\f’ and space.

        * Null character (U+0000) no longer ends the tag name.

        * Attributes and slashes after the tag name in end tags are now
          ignored, instead of terminating after the first ‘>’ in quoted
          attribute value.  E.g.  ‘</script/foo=">"/>’.

        * Multiple slashes and whitespaces between the last attribute
          and closing ‘>’ are now ignored in both start and end tags.
          E.g.  ‘<a foo=bar/ //>’.

        * Multiple ‘=’ between attribute name and value are no longer
          collapsed.  E.g.  ‘<a foo==bar>’ produces attribute «foo» with
          value «=bar».

        * [Reverted in gh-136927(3)] Whitespaces between the ‘=’
          separator and attribute name or value are no longer ignored.
          E.g.  ‘<a foo =bar>’ produces two attributes «foo» and «=bar»,
          both with value None; ‘<a foo= bar>’ produces two attributes:
          «foo» with value «» and «bar» with value None.

   - gh-102555(4): Fix comment parsing in *note html.parser.HTMLParser:
     a79. according to the HTML5 standard.  ‘--!>’ now ends the comment.
     ‘-- >’ no longer ends the comment.  Support abnormally ended empty
     comments ‘<-->’ and ‘<--->’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/136053

   (2) https://github.com/python/cpython/issues/135661

   (3) https://github.com/python/cpython/issues/136927

   (4) https://github.com/python/cpython/issues/102555


File: python.info,  Node: Library<17>,  Next: Documentation<5>,  Prev: Security<7>,  Up: Python 3 14 0 beta 4

1.24.8.4 Library
................

   - gh-136286(1): Fix pickling failures for protocols 0 and 1 for many
     objects realted to subinterpreters.

   - gh-136316(2): Improve support for evaluating nested forward
     references in *note typing.evaluate_forward_ref(): 17fd.

   - gh-85702(3): If ‘zoneinfo._common.load_tzdata’ is given a package
     without a resource a *note zoneinfo.ZoneInfoNotFoundError: 17fe. is
     raised rather than a *note PermissionError: f40.  Patch by Victor
     Stinner.

   - gh-136028(4): Fix parsing month names containing «İ» (U+0130, LATIN
     CAPITAL LETTER I WITH DOT ABOVE) in *note time.strptime(): 1634.
     This affects locales az_AZ, ber_DZ, ber_MA and crh_UA.

   - gh-135995(5): In the palmos encoding, make byte ‘0x9b’ decode to
     ‘›’ (U+203A - SINGLE RIGHT-POINTING ANGLE QUOTATION MARK).

   - gh-53203(6): Fix *note time.strptime(): 1634. for ‘%c’ and ‘%x’
     formats on locales byn_ER, wal_ET and lzh_TW, and for ‘%X’ format
     on locales ar_SA, bg_BG and lzh_TW.

   - gh-91555(7): An earlier change, which was introduced in 3.14.0b2,
     has been reverted.  It disabled logging for a logger during
     handling of log messages for that logger.  Since the reversion, the
     behaviour should be as it was before 3.14.0b2.

   - gh-135878(8): Fixes a crash of *note types.SimpleNamespace: 4e6. on
     *note free threading: 1f4. builds, when several threads were
     calling its *note __repr__(): 830. method at the same time.

   - gh-135836(9): Fix *note IndexError: 173c. in *note
     asyncio.loop.create_connection(): 819. that could occur when
     non-*note OSError: 2c0. exception is raised during connection and
     socket’s ‘close()’ raises ‘OSError’.

   - gh-135836(10): Fix *note IndexError: 173c. in *note
     asyncio.loop.create_connection(): 819. that could occur when the
     Happy Eyeballs algorithm resulted in an empty exceptions list
     during connection attempts.

   - gh-135855(11): Raise *note TypeError: 198. instead of *note
     SystemError: 796. when ‘_interpreters.set___main___attrs()’ is
     passed a non-dict object.  Patch by Brian Schubert.

   - gh-135815(12): *note netrc: 9f.: skip security checks if *note
     os.getuid(): 17ff. is missing.  Patch by Bénédikt Tran.

   - gh-135640(13): Address bug where it was possible to call *note
     xml.etree.ElementTree.ElementTree.write(): c8e. on an ElementTree
     object with an invalid root element.  This behavior blanked the
     file passed to ‘write’ if it already existed.

   - gh-135645(14): Added ‘supports_isolated_interpreters’ field to
     *note sys.implementation: 73c.

   - gh-135646(15): Raise consistent *note NameError: 452. exceptions in
     *note annotationlib.ForwardRef.evaluate(): 179a.

   - gh-135557(16): Fix races on *note heapq: 6d. updates and *note
     list: 24d. reads on the *note free threaded: 1f4. build.

   - gh-119180(17): Only fetch globals and locals if necessary in *note
     annotationlib.get_annotations(): 459.

   - gh-135561(18): Fix a crash on DEBUG builds when an HACL* HMAC
     routine fails.  Patch by Bénédikt Tran.

   - gh-135487(19): Fix ‘reprlib.Repr.repr_int()’ when given integers
     with more than *note sys.get_int_max_str_digits(): 1800. digits.
     Patch by Bénédikt Tran.

   - gh-135335(20): *note multiprocessing: 98.: Flush ‘stdout’ and
     ‘stderr’ after preloading modules in the ‘forkserver’.

   - gh-135069(21): Fix the «Invalid error handling» exception in
     ‘encodings.idna.IncrementalDecoder’ to correctly replace the
     “errors” parameter.

   - gh-130662(22): +Accept leading zeros in precision and width fields
     for +:class:*note Decimal: 1fe. formatting, for example
     ‘format(Decimal(1.25), '.016f')’.

   - gh-130662(23): Accept leading zeros in precision and width fields
     for *note Fraction: 213. formatting, for example
     ‘format(Fraction(1, 3), '.016f')’.

   - gh-87790(24): Support underscore and comma as thousands separators
     in the fractional part for *note Fraction: 213.’s formatting.
     Patch by Sergey B Kirpichev.

   - gh-87790(25): Support underscore and comma as thousands separators
     in the fractional part for *note Decimal: 1fe.’s formatting.  Patch
     by Sergey B Kirpichev.

   - gh-130664(26): Handle corner-case for *note Fraction: 213.’s
     formatting: treat zero-padding (preceding the width field by a zero
     (‘'0'’) character) as an equivalent to a fill character of ‘'0'’
     with an alignment type of ‘'='’, just as in case of *note float:
     196.’s.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/136286

   (2) https://github.com/python/cpython/issues/136316

   (3) https://github.com/python/cpython/issues/85702

   (4) https://github.com/python/cpython/issues/136028

   (5) https://github.com/python/cpython/issues/135995

   (6) https://github.com/python/cpython/issues/53203

   (7) https://github.com/python/cpython/issues/91555

   (8) https://github.com/python/cpython/issues/135878

   (9) https://github.com/python/cpython/issues/135836

   (10) https://github.com/python/cpython/issues/135836

   (11) https://github.com/python/cpython/issues/135855

   (12) https://github.com/python/cpython/issues/135815

   (13) https://github.com/python/cpython/issues/135640

   (14) https://github.com/python/cpython/issues/135645

   (15) https://github.com/python/cpython/issues/135646

   (16) https://github.com/python/cpython/issues/135557

   (17) https://github.com/python/cpython/issues/119180

   (18) https://github.com/python/cpython/issues/135561

   (19) https://github.com/python/cpython/issues/135487

   (20) https://github.com/python/cpython/issues/135335

   (21) https://github.com/python/cpython/issues/135069

   (22) https://github.com/python/cpython/issues/130662

   (23) https://github.com/python/cpython/issues/130662

   (24) https://github.com/python/cpython/issues/87790

   (25) https://github.com/python/cpython/issues/87790

   (26) https://github.com/python/cpython/issues/130664


File: python.info,  Node: Documentation<5>,  Next: Core and Builtins<15>,  Prev: Library<17>,  Up: Python 3 14 0 beta 4

1.24.8.5 Documentation
......................

   - gh-136155(1): EPUB builds are fixed by excluding
     non-XHTML-compatible tags.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/136155


File: python.info,  Node: Core and Builtins<15>,  Next: C API<5>,  Prev: Documentation<5>,  Up: Python 3 14 0 beta 4

1.24.8.6 Core and Builtins
..........................

   - gh-109700(1): Fix memory error handling in *note
     PyDict_SetDefault(): 5e4.

   - gh-78465(2): Fix error message for ‘cls.__new__(cls, ...)’ where
     ‘cls’ is not instantiable builtin or extension type (with ‘tp_new’
     set to ‘NULL’).

   - gh-129958(3): Differentiate between t-strings and f-strings in
     syntax error for newlines in format specifiers of single-quoted
     interpolated strings.

   - gh-135871(4): Non-blocking mutex lock attempts now return
     immediately when the lock is busy instead of briefly spinning in
     the *note free threading: 1f4. build.

   - gh-135106(5): Restrict the trashcan mechanism to GC’ed objects and
     untrack them while in the trashcan to prevent the GC and trashcan
     mechanisms conflicting.

   - gh-135607(6): Fix potential *note weakref: 11a. races in an
     object’s destructor on the *note free threaded: 1f4. build.

   - gh-135608(7): Fix a crash in the JIT involving attributes of
     modules.

   - gh-135543(8): Emit ‘sys.remote_exec’ audit event when *note
     sys.remote_exec(): 16d. is called and migrate
     ‘remote_debugger_script’ to ‘cpython.remote_debugger_script’.

   - gh-134280(9): Disable constant folding for ‘~’ with a boolean
     argument.  This moves the deprecation warning from compile time to
     runtime.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109700

   (2) https://github.com/python/cpython/issues/78465

   (3) https://github.com/python/cpython/issues/129958

   (4) https://github.com/python/cpython/issues/135871

   (5) https://github.com/python/cpython/issues/135106

   (6) https://github.com/python/cpython/issues/135607

   (7) https://github.com/python/cpython/issues/135608

   (8) https://github.com/python/cpython/issues/135543

   (9) https://github.com/python/cpython/issues/134280


File: python.info,  Node: C API<5>,  Next: Build<5>,  Prev: Core and Builtins<15>,  Up: Python 3 14 0 beta 4

1.24.8.7 C API
..............

   - gh-135906(1): Fix compilation errors when compiling the internal
     headers with a C++ compiler.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135906


File: python.info,  Node: Build<5>,  Prev: C API<5>,  Up: Python 3 14 0 beta 4

1.24.8.8 Build
..............

   - gh-134273(1): Add support for configuring compiler flags for the
     JIT with ‘CFLAGS_JIT’

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/134273


File: python.info,  Node: Python 3 14 0 beta 3,  Next: Python 3 14 0 beta 2,  Prev: Python 3 14 0 beta 4,  Up: Changelog

1.24.9 Python 3.14.0 beta 3
---------------------------

'Release date: 2025-06-17'

* Menu:

* Windows: Windows<6>.
* Tests: Tests<4>.
* Security: Security<8>.
* Library: Library<18>.
* Documentation: Documentation<6>.
* Core and Builtins: Core and Builtins<16>.
* Library: Library<19>.
* Core and Builtins: Core and Builtins<17>.
* Library: Library<20>.
* Core and Builtins: Core and Builtins<18>.
* Library: Library<21>.
* Core and Builtins: Core and Builtins<19>.
* C API: C API<6>.
* Build: Build<6>.


File: python.info,  Node: Windows<6>,  Next: Tests<4>,  Up: Python 3 14 0 beta 3

1.24.9.1 Windows
................

   - gh-135099(1): Fix a crash that could occur on Windows when a
     background thread waits on a *note PyMutex: 485. while the main
     thread is shutting down the interpreter.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135099


File: python.info,  Node: Tests<4>,  Next: Security<8>,  Prev: Windows<6>,  Up: Python 3 14 0 beta 3

1.24.9.2 Tests
..............

   - gh-132815(1): Fix test__opcode: add ‘JUMP_BACKWARD’ to
     specialization stats.

   - gh-135489(2): Show verbose output for failing tests during PGO
     profiling step with –enable-optimizations.

   - gh-135120(3): Add ‘test.support.subTests()’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132815

   (2) https://github.com/python/cpython/issues/135489

   (3) https://github.com/python/cpython/issues/135120


File: python.info,  Node: Security<8>,  Next: Library<18>,  Prev: Tests<4>,  Up: Python 3 14 0 beta 3

1.24.9.3 Security
.................

   - gh-135462(1): Fix quadratic complexity in processing specially
     crafted input in *note html.parser.HTMLParser: a79.  End-of-file
     errors are now handled according to the HTML5 specs – comments and
     declarations are automatically closed, tags are ignored.

   - gh-135034(2): Fixes multiple issues that allowed ‘tarfile’
     extraction filters (‘filter="data"’ and ‘filter="tar"’) to be
     bypassed using crafted symlinks and hard links.

     Addresses CVE 2024-12718(3), CVE 2025-4138(4), CVE 2025-4330(5),
     and CVE 2025-4517(6).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135462

   (2) https://github.com/python/cpython/issues/135034

   (3) https://www.cve.org/CVERecord?id=CVE-2024-12718

   (4) https://www.cve.org/CVERecord?id=CVE-2025-4138

   (5) https://www.cve.org/CVERecord?id=CVE-2025-4330

   (6) https://www.cve.org/CVERecord?id=CVE-2025-4517


File: python.info,  Node: Library<18>,  Next: Documentation<6>,  Prev: Security<8>,  Up: Python 3 14 0 beta 3

1.24.9.4 Library
................

   - gh-65697(1): *note configparser: 26.’s error message when
     attempting to write an invalid key is now more helpful.

   - gh-135497(2): Fix *note os.getlogin(): 180a. failing for longer
     usernames on BSD-based platforms.

   - gh-135429(3): Fix the argument mismatch in ‘_lsprof’ for ‘PY_THROW’
     event.

   - gh-135368(4): Fix *note unittest.mock.Mock: c41. generation on
     *note dataclasses.dataclass(): 4e2. objects.  Now all special
     attributes are set as it was before gh-124429(5).

   - gh-133967(6): Do not normalize *note locale: 8a. name “C.UTF-8” to
     “en_US.UTF-8”.

   - gh-135321(7): Raise a correct exception for values greater than
     0x7fffffff for the ‘BINSTRING’ opcode in the C implementation of
     *note pickle: ab.

   - gh-135276(8): Backported bugfixes in zipfile.Path from zipp 3.23.
     Fixed ‘.name’, ‘.stem’ and other basename-based properties on
     Windows when working with a zipfile on disk.

   - gh-135244(9): *note uuid: 116.: when the MAC address cannot be
     determined, the 48-bit node ID is now generated with a
     cryptographically-secure pseudo-random number generator (CSPRNG) as
     per RFC 9562, §6.10.3(10).  This affects *note uuid1(): da3. and
     *note uuid6(): 2c2.

   - gh-134970(11): Fix the «unknown action» exception in *note
     argparse.ArgumentParser.add_argument_group(): 2eb. to correctly
     replace the action class.

   - gh-134718(12): *note ast.dump(): ae3. now only omits ‘None’ and
     ‘[]’ values if they are default values.

   - gh-134939(13): Add the *note concurrent.interpreters: 25. module.
     See PEP 734(14).

   - gh-134885(15): Fix possible crash in the *note compression.zstd:
     23. module related to setting parameter types.  Patch by Jelle
     Zijlstra.

   - gh-134857(16): Improve error report for *note doctest: 3e.s run
     with *note unittest: 10c.  Remove ‘doctest’ module frames from
     tracebacks and redundant newline character from a failure message.

   - gh-128840(17): Fix parsing long IPv6 addresses with embedded IPv4
     address.

   - gh-134637(18): Fix performance regression in calling a *note
     ctypes: 2e. function pointer in *note free threading: 1f4.

   - gh-134696(19): Built-in HACL* and OpenSSL implementations of hash
     function constructors now correctly accept the same 'documented'
     named arguments.  For instance, *note md5(): 180b. could be
     previously invoked as ‘md5(data=data)’ or ‘md5(string=string)’
     depending on the underlying implementation but these calls were not
     compatible.  Patch by Bénédikt Tran.

   - gh-134151(20): *note email: 3f.: Fix *note TypeError: 198. in *note
     email.utils.decode_params(): 180c. when sorting RFC 2231(21)
     continuations that contain an unnumbered section.

   - gh-134210(22): *note curses.window.getch(): 180d. now correctly
     handles signals.  Patch by Bénédikt Tran.

   - gh-134152(23): *note email: 3f.: Fix parsing of email message ID
     with invalid domain.

   - gh-133489(24): *note random.getrandbits(): 120f. can now generate
     more that 2^31 bits.  *note random.randbytes(): 180e. can now
     generate more that 256 MiB.

   - gh-132813(25): Improve error messages for incorrect types and
     values of *note csv.Dialect: 180f. attributes.

   - gh-132969(26): Prevent the *note ProcessPoolExecutor: 1d6. executor
     thread, which remains running when *note shutdown(wait=False): aec,
     from attempting to adjust the pool’s worker processes after the
     object state has already been reset during shutdown.  A combination
     of conditions, including a worker process having terminated
     abormally, resulted in an exception and a potential hang when the
     still-running executor thread attempted to replace dead workers
     within the pool.

   - gh-127081(27): Fix libc thread safety issues with *note os: a5. by
     replacing ‘getlogin’ with ‘getlogin_r’ re-entrant version.

   - gh-131884(28): Fix formatting issues in *note json.dump(): f42.
     when both 'indent' and 'skipkeys' are used.

   - gh-130999(29): Avoid exiting the new REPL and offer suggestions
     even if there are non-string candidates when errors occur.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/65697

   (2) https://github.com/python/cpython/issues/135497

   (3) https://github.com/python/cpython/issues/135429

   (4) https://github.com/python/cpython/issues/135368

   (5) https://github.com/python/cpython/issues/124429

   (6) https://github.com/python/cpython/issues/133967

   (7) https://github.com/python/cpython/issues/135321

   (8) https://github.com/python/cpython/issues/135276

   (9) https://github.com/python/cpython/issues/135244

   (10) 
https://datatracker.ietf.org/doc/html/rfc9562.html#section-6.10-3

   (11) https://github.com/python/cpython/issues/134970

   (12) https://github.com/python/cpython/issues/134718

   (13) https://github.com/python/cpython/issues/134939

   (14) https://peps.python.org/pep-0734/

   (15) https://github.com/python/cpython/issues/134885

   (16) https://github.com/python/cpython/issues/134857

   (17) https://github.com/python/cpython/issues/128840

   (18) https://github.com/python/cpython/issues/134637

   (19) https://github.com/python/cpython/issues/134696

   (20) https://github.com/python/cpython/issues/134151

   (21) https://datatracker.ietf.org/doc/html/rfc2231.html

   (22) https://github.com/python/cpython/issues/134210

   (23) https://github.com/python/cpython/issues/134152

   (24) https://github.com/python/cpython/issues/133489

   (25) https://github.com/python/cpython/issues/132813

   (26) https://github.com/python/cpython/issues/132969

   (27) https://github.com/python/cpython/issues/127081

   (28) https://github.com/python/cpython/issues/131884

   (29) https://github.com/python/cpython/issues/130999


File: python.info,  Node: Documentation<6>,  Next: Core and Builtins<16>,  Prev: Library<18>,  Up: Python 3 14 0 beta 3

1.24.9.5 Documentation
......................

   - gh-135171(1): Document that the *note iterator: 4c9. for the
     leftmost ‘for’ clause in the generator expression is created
     immediately.

   - bpo-45210(2): Document that error indicator may be set in
     tp_dealloc, and how to avoid clobbering it.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135171

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45210


File: python.info,  Node: Core and Builtins<16>,  Next: Library<19>,  Prev: Documentation<6>,  Up: Python 3 14 0 beta 3

1.24.9.6 Core and Builtins
..........................

   - gh-135496(1): Fix typo in the f-string conversion type error
     («exclamanation» -> «exclamation»).

   - gh-135371(2): Fixed *note asyncio: b. debugging tools to properly
     display internal coroutine call stacks alongside external task
     dependencies.  The ‘python -m asyncio ps’ and ‘python -m asyncio
     pstree’ commands now show complete execution context.  Patch by
     Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135496

   (2) https://github.com/python/cpython/issues/135371


File: python.info,  Node: Library<19>,  Next: Core and Builtins<17>,  Prev: Core and Builtins<16>,  Up: Python 3 14 0 beta 3

1.24.9.7 Library
................

   - gh-127319(1): Set the ‘allow_reuse_port’ class variable to ‘False’
     on the XMLRPC, logging, and HTTP servers.  This matches the
     behavior in prior Python releases, which is to not allow port
     reuse.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127319


File: python.info,  Node: Core and Builtins<17>,  Next: Library<20>,  Prev: Library<19>,  Up: Python 3 14 0 beta 3

1.24.9.8 Core and Builtins
..........................

   - gh-135171(1): Reverts the behavior of async generator expressions
     when created with object w/o __aiter__ method to the pre-3.13
     behavior of raising a TypeError.

   - gh-130077(2): Properly raise custom syntax errors when incorrect
     syntax containing names that are prefixes of soft keywords is
     encountered.  Patch by Pablo Galindo.

   - gh-135171(3): Reverts the behavior of generator expressions when
     created with a non-iterable to the pre-3.13 behavior of raising a
     TypeError.  It is no longer possible to cause a crash in the
     debugger by altering the generator expression’s local variables.
     This is achieved by moving the ‘GET_ITER’ instruction back to the
     creation of the generator expression and adding an additional check
     to ‘FOR_ITER’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/135171

   (2) https://github.com/python/cpython/issues/130077

   (3) https://github.com/python/cpython/issues/135171


File: python.info,  Node: Library<20>,  Next: Core and Builtins<18>,  Prev: Core and Builtins<17>,  Up: Python 3 14 0 beta 3

1.24.9.9 Library
................

   - gh-116738(1): Make methods in *note heapq: 6d. thread-safe on the
     *note free threaded: 1f4. build.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116738


File: python.info,  Node: Core and Builtins<18>,  Next: Library<21>,  Prev: Library<20>,  Up: Python 3 14 0 beta 3

1.24.9.10 Core and Builtins
...........................

   - gh-134876(1): Add support to PEP 768(2) remote debugging for Linux
     kernels which don’t have CONFIG_CROSS_MEMORY_ATTACH configured.

   - gh-134889(3): Fix handling of a few opcodes that leave operands on
     the stack when optimizing ‘LOAD_FAST’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/134876

   (2) https://peps.python.org/pep-0768/

   (3) https://github.com/python/cpython/issues/134889


File: python.info,  Node: Library<21>,  Next: Core and Builtins<19>,  Prev: Core and Builtins<18>,  Up: Python 3 14 0 beta 3

1.24.9.11 Library
.................

   - gh-134908(1): Fix crash when iterating over lines in a text file on
     the *note free threaded: 1f4. build.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/134908


File: python.info,  Node: Core and Builtins<19>,  Next: C API<6>,  Prev: Library<21>,  Up: Python 3 14 0 beta 3

1.24.9.12 Core and Builtins
...........................

   - gh-132617(1): Fix *note dict.update(): 166c. modification check
     that could incorrectly raise a «dict mutated during update» error
     when a different dictionary was modified that happens to share the
     same underlying keys object.

   - gh-134679(2): Fix crash in the *note free threading: 1f4. build’s
     QSBR code that could occur when changing an object’s ‘__dict__’
     attribute.

   - gh-127682(3): No longer call ‘__iter__’ twice in list
     comprehensions.  This brings the behavior of list comprehensions in
     line with other forms of iteration

   - gh-133912(4): Fix the C API function ‘PyObject_GenericSetDict’ to
     handle extension classes with inline values.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132617

   (2) https://github.com/python/cpython/issues/134679

   (3) https://github.com/python/cpython/issues/127682

   (4) https://github.com/python/cpython/issues/133912


File: python.info,  Node: C API<6>,  Next: Build<6>,  Prev: Core and Builtins<19>,  Up: Python 3 14 0 beta 3

1.24.9.13 C API
...............

   - gh-134989(1): Fix ‘Py_RETURN_NONE’, ‘Py_RETURN_TRUE’ and
     ‘Py_RETURN_FALSE’ macros in the limited C API 3.11 and older: don’t
     treat ‘Py_None’, ‘Py_True’ and ‘Py_False’ as immortal.  Patch by
     Victor Stinner.

   - gh-134989(2): Implement *note PyObject_DelAttr(): 1819. and *note
     PyObject_DelAttrString(): 181a. as macros in the limited C API 3.12
     and older.  Patch by Victor Stinner.

   - gh-133968(3): Add *note PyUnicodeWriter_WriteASCII(): 3b9. function
     to write an ASCII string into a *note PyUnicodeWriter: 3b3.  The
     function is faster than *note PyUnicodeWriter_WriteUTF8(): 3bf, but
     has an undefined behavior if the input string contains non-ASCII
     characters.  Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/134989

   (2) https://github.com/python/cpython/issues/134989

   (3) https://github.com/python/cpython/issues/133968


File: python.info,  Node: Build<6>,  Prev: C API<6>,  Up: Python 3 14 0 beta 3

1.24.9.14 Build
...............

   - gh-119132(1): Remove «experimental» tag from the CPython
     free-threading build.

   - gh-135497(2): Fix the detection of ‘MAXLOGNAME’ in the
     ‘configure.ac’ script.

   - gh-134923(3): Windows builds with profile-guided optimization
     enabled now use ‘/GENPROFILE’ and ‘/USEPROFILE’ instead of
     deprecated ‘/LTCG:’ options.

   - gh-134774(4): Fix *note Py_DEBUG: 181c. macro redefinition warnings
     on Windows debug builds.  Patch by Chris Eibl.

   - gh-134632(5): Fixed ‘build-details.json’ generation to use
     ‘INCLUDEPY’, in order to reference the ‘pythonX.Y’ subdirectory of
     the include directory, as required in PEP 739(6), instead of the
     top-level include directory.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/119132

   (2) https://github.com/python/cpython/issues/135497

   (3) https://github.com/python/cpython/issues/134923

   (4) https://github.com/python/cpython/issues/134774

   (5) https://github.com/python/cpython/issues/134632

   (6) https://peps.python.org/pep-0739/


File: python.info,  Node: Python 3 14 0 beta 2,  Next: Python 3 14 0 beta 1,  Prev: Python 3 14 0 beta 3,  Up: Changelog

1.24.10 Python 3.14.0 beta 2
----------------------------

'Release date: 2025-05-26'

* Menu:

* Windows: Windows<7>.
* Tools/Demos: Tools/Demos<7>.
* Tests: Tests<5>.
* Security: Security<9>.
* Library: Library<22>.
* Core and Builtins: Core and Builtins<20>.
* C API: C API<7>.
* Build: Build<7>.


File: python.info,  Node: Windows<7>,  Next: Tools/Demos<7>,  Up: Python 3 14 0 beta 2

1.24.10.1 Windows
.................

   - gh-130727(1): Fix a race in internal calls into WMI that can result
     in an «invalid handle» exception under high load.  Patch by Chris
     Eibl.

   - gh-76023(2): Make *note os.path.realpath(): 262. ignore Windows
     error 1005 when in non-strict mode.

   - gh-133779(3): Reverts the change to generate different ‘pyconfig.h’
     files based on compiler settings, as it was frequently causing
     extension builds to break.  In particular, the ‘Py_GIL_DISABLED’
     preprocessor variable must now always be defined explicitly when
     compiling for the experimental free-threaded runtime.  The *note
     sysconfig.get_config_var(): 174. function can be used to determine
     whether the current runtime was compiled with that flag or not.

   - gh-133626(4): Ensures packages are not accidentally bundled into
     the traditional installer.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/130727

   (2) https://github.com/python/cpython/issues/76023

   (3) https://github.com/python/cpython/issues/133779

   (4) https://github.com/python/cpython/issues/133626


File: python.info,  Node: Tools/Demos<7>,  Next: Tests<5>,  Prev: Windows<7>,  Up: Python 3 14 0 beta 2

1.24.10.2 Tools/Demos
.....................

   - gh-134215(1): *note REPL: 492. import autocomplete only suggests
     private modules when explicitly specified.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/134215


File: python.info,  Node: Tests<5>,  Next: Security<9>,  Prev: Tools/Demos<7>,  Up: Python 3 14 0 beta 2

1.24.10.3 Tests
...............

   - gh-133744(1): Fix multiprocessing interrupt test.  Add an event to
     synchronize the parent process with the child process: wait until
     the child process starts sleeping.  Patch by Victor Stinner.

   - gh-133682(2): Fixed test case
     ‘test.test_annotationlib.TestStringFormat.test_displays’ which
     ensures proper handling of complex data structures (lists, sets,
     dictionaries, and tuples) in string annotations.

   - gh-133639(3): Fix ‘TestPyReplAutoindent.test_auto_indent_default()’
     doesn’t run ‘input_code’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/133744

   (2) https://github.com/python/cpython/issues/133682

   (3) https://github.com/python/cpython/issues/133639


File: python.info,  Node: Security<9>,  Next: Library<22>,  Prev: Tests<5>,  Up: Python 3 14 0 beta 2

1.24.10.4 Security
..................

   - gh-133767(1): Fix use-after-free in the «unicode-escape» decoder
     with a non-«strict» error handler.

   - gh-128840(2): Short-circuit the processing of long IPv6 addresses
     early in *note ipaddress: 84. to prevent excessive memory
     consumption and a minor denial-of-service.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/133767

   (2) https://github.com/python/cpython/issues/128840


File: python.info,  Node: Library<22>,  Next: Core and Builtins<20>,  Prev: Security<9>,  Up: Python 3 14 0 beta 2

1.24.10.5 Library
.................

   - gh-132710(1): If possible, ensure that *note uuid.getnode(): da2.
     returns the same result even across different processes.
     Previously, the result was constant only within the same process.
     Patch by Bénédikt Tran.

   - gh-80334(2): *note multiprocessing.freeze_support(): 1823. now
     checks for work on any «spawn» start method platform rather than
     only on Windows.

   - gh-134582(3): Fix tokenize.untokenize() round-trip errors related
     to t-strings braces escaping

   - gh-134546(4): Ensure *note pdb: aa. remote debugging script is
     readable by remote Python process.

   - gh-134451(5): Converted ‘asyncio.tools.CycleFoundException’ from
     dataclass to a regular exception type.

   - gh-114177(6): Fix *note asyncio: b. to not close subprocess pipes
     which would otherwise error out when the event loop is already
     closed.

   - gh-90871(7): Fixed an off by one error concerning the backlog
     parameter in *note create_unix_server(): 4cb.  Contributed by
     Christian Harries.

   - gh-134323(8): Fix the *note threading.RLock.locked(): 1824. method.

   - gh-86802(9): Fixed asyncio memory leak in cancelled shield tasks.
     For shielded tasks where the shield was cancelled, log potential
     exceptions through the exception handler.  Contributed by Christian
     Harries.

   - gh-134209(10): *note curses: 2f.: The *note curses.window.instr():
     1825. and *note curses.window.getstr(): 1826. methods now allocate
     their internal buffer on the heap instead of the stack; in
     addition, the max buffer size is increased from 1023 to 2047.

   - gh-134235(11): Updated tab completion on REPL to include builtin
     modules.  Contributed by Tom Wang, Hunter Young

   - gh-134152(12): Fixed *note UnboundLocalError: 173d. that could
     occur during *note email: 3f. header parsing if an expected
     trailing delimiter is missing in some contexts.

   - gh-134168(13): *note http.server: 76.: Fix IPv6 address binding and
     *note -directory: 1827. handling when using HTTPS.

   - gh-62184(14): Remove import of C implementation of *note io.FileIO:
     1517. from Python implementation which has its own implementation

   - gh-133982(15): Emit *note RuntimeWarning: 4d8. in the Python
     implementation of *note io: 83. when the *note file-like object:
     13cb. is not closed explicitly in the presence of multiple I/O
     layers.

   - gh-133890(16): The *note tarfile: e4. module now handles *note
     UnicodeEncodeError: 888. in the same way as *note OSError: 2c0.
     when cannot extract a member.

   - gh-134097(17): Fix interaction of the new *note REPL: 492. and
     *note -X showrefcount: 16f. command line option.

   - gh-133889(18): The generated directory listing page in *note
     http.server.SimpleHTTPRequestHandler: d3a. now only shows the
     decoded path component of the requested URL, and not the query and
     fragment.

   - gh-134098(19): Fix handling paths that end with a percent-encoded
     slash (‘%2f’ or ‘%2F’) in *note
     http.server.SimpleHTTPRequestHandler: d3a.

   - gh-132124(20): On POSIX-compliant systems,
     ‘multiprocessing.util.get_temp_dir()’ now ignores ‘TMPDIR’ (and
     similar environment variables) if the path length of ‘AF_UNIX’
     socket files exceeds the platform-specific maximum length when
     using the *note forkserver: 1d4. start method.  Patch by Bénédikt
     Tran.

   - gh-134062(21): *note ipaddress: 84.: fix collisions in *note
     __hash__(): cf5. for *note IPv4Network: 50f. and *note IPv6Network:
     510. objects.

   - gh-133970(22): Make ‘string.templatelib.Template’ and
     ‘string.templatelib.Interpolation’ generic.

   - gh-71253(23): Raise *note ValueError: 2ec. in *note open(): 316. if
     'opener' returns a negative file-descriptor in the Python
     implementation of *note io: 83. to match the C implementation.

   - gh-133960(24): Simplify and improve *note
     typing.evaluate_forward_ref(): 17fd.  It now no longer raises
     errors on certain invalid types.  In several situations, it is now
     able to evaluate forward references that were previously
     unsupported.

   - gh-133925(25): Make the private class ‘typing._UnionGenericAlias’
     hashable.

   - gh-133653(26): Fix *note argparse.ArgumentParser: 1bd. with the
     'formatter_class' argument.  Fix TypeError when 'formatter_class'
     is a custom subclass of ‘HelpFormatter’.  Fix TypeError when
     'formatter_class' is not a subclass of ‘HelpFormatter’ and
     non-standard 'prefix_char' is used.  Fix support of colorizing when
     'formatter_class' is not a subclass of ‘HelpFormatter’.

   - gh-132641(27): Fixed a race in *note functools.lru_cache(): be4.
     under free-threading.

   - gh-133783(28): Fix bug with applying *note copy.replace(): 1c0. to
     *note ast: 9. objects.  Attributes that default to ‘None’ were
     incorrectly treated as required for manually created AST nodes.

   - gh-133684(29): Fix bug where *note annotationlib.get_annotations():
     459. would return the wrong result for certain classes that are
     part of a class hierarchy where ‘from __future__ import
     annotations’ is used.

   - gh-77057(30): Fix handling of invalid markup declarations in *note
     html.parser.HTMLParser: a79.

   - gh-130328(31): Speedup pasting in ‘PyREPL’ on Windows in a legacy
     console.  Patch by Chris Eibl.

   - gh-133701(32): Fix bug where *note typing.TypedDict: 332. classes
     defined under ‘from __future__ import annotations’ and inheriting
     from another ‘TypedDict’ had an incorrect ‘__annotations__’
     attribute.

   - gh-133581(33): Improve unparsing of t-strings in *note
     ast.unparse(): ae4. and ‘from __future__ import annotations’.
     Empty t-strings now round-trip correctly and formatting in
     interpolations is preserved.  Patch by Jelle Zijlstra.

   - gh-133551(34): Support t-strings ( PEP 750(35)) in *note
     annotationlib: 6.  Patch by Jelle Zijlstra.

   - gh-133439(36): Fix dot commands with trailing spaces are mistaken
     for multi-line SQL statements in the sqlite3 command-line
     interface.

   - gh-132493(37): Avoid accessing ‘__annotations__’ unnecessarily in
     *note inspect.signature(): 22f.

   - gh-132876(38): ‘ldexp()’ on Windows doesn’t round subnormal results
     before Windows 11, but should.  Python’s *note math.ldexp(): 1828.
     wrapper now does round them, so results may change slightly, in
     rare cases of very small results, on Windows versions before 11.

   - gh-133009(39): *note xml.etree.ElementTree: 12b.: Fix a crash in
     *note Element.__deepcopy__: 17c9. when the element is concurrently
     mutated.  Patch by Bénédikt Tran.

   - gh-91555(40): Ignore log messages generated during handling of log
     messages, to avoid deadlock or infinite recursion.  [NOTE: This
     change has since been reverted.]

   - gh-125028(41): *note functools.Placeholder: 216. cannot be passed
     to *note functools.partial(): 217. as a keyword argument.

   - gh-62824(42): Fix aliases for ‘iso8859_8’ encoding.  Patch by Dave
     Goncalves.

   - gh-86155(43): *note html.parser.HTMLParser.close(): 1829. no longer
     loses data when the ‘<script>’ tag is not closed.  Patch by Waylan
     Limberg.

   - gh-69426(44): Fix *note html.parser.HTMLParser: a79. to not
     unescape character entities in attribute values if they are
     followed by an ASCII alphanumeric or an equals sign.

   - bpo-28494(45): Improve Zip file validation false positive rate in
     *note zipfile.is_zipfile(): 1532.

   - gh-134381(46): Fix *note RuntimeError: 244. when using a
     not-started *note threading.Thread: 176. after calling *note
     os.fork(): 4b6.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132710

   (2) https://github.com/python/cpython/issues/80334

   (3) https://github.com/python/cpython/issues/134582

   (4) https://github.com/python/cpython/issues/134546

   (5) https://github.com/python/cpython/issues/134451

   (6) https://github.com/python/cpython/issues/114177

   (7) https://github.com/python/cpython/issues/90871

   (8) https://github.com/python/cpython/issues/134323

   (9) https://github.com/python/cpython/issues/86802

   (10) https://github.com/python/cpython/issues/134209

   (11) https://github.com/python/cpython/issues/134235

   (12) https://github.com/python/cpython/issues/134152

   (13) https://github.com/python/cpython/issues/134168

   (14) https://github.com/python/cpython/issues/62184

   (15) https://github.com/python/cpython/issues/133982

   (16) https://github.com/python/cpython/issues/133890

   (17) https://github.com/python/cpython/issues/134097

   (18) https://github.com/python/cpython/issues/133889

   (19) https://github.com/python/cpython/issues/134098

   (20) https://github.com/python/cpython/issues/132124

   (21) https://github.com/python/cpython/issues/134062

   (22) https://github.com/python/cpython/issues/133970

   (23) https://github.com/python/cpython/issues/71253

   (24) https://github.com/python/cpython/issues/133960

   (25) https://github.com/python/cpython/issues/133925

   (26) https://github.com/python/cpython/issues/133653

   (27) https://github.com/python/cpython/issues/132641

   (28) https://github.com/python/cpython/issues/133783

   (29) https://github.com/python/cpython/issues/133684

   (30) https://github.com/python/cpython/issues/77057

   (31) https://github.com/python/cpython/issues/130328

   (32) https://github.com/python/cpython/issues/133701

   (33) https://github.com/python/cpython/issues/133581

   (34) https://github.com/python/cpython/issues/133551

   (35) https://peps.python.org/pep-0750/

   (36) https://github.com/python/cpython/issues/133439

   (37) https://github.com/python/cpython/issues/132493

   (38) https://github.com/python/cpython/issues/132876

   (39) https://github.com/python/cpython/issues/133009

   (40) https://github.com/python/cpython/issues/91555

   (41) https://github.com/python/cpython/issues/125028

   (42) https://github.com/python/cpython/issues/62824

   (43) https://github.com/python/cpython/issues/86155

   (44) https://github.com/python/cpython/issues/69426

   (45) https://bugs.python.org/issue?@action=redirect&bpo=28494

   (46) https://github.com/python/cpython/issues/134381


File: python.info,  Node: Core and Builtins<20>,  Next: C API<7>,  Prev: Library<22>,  Up: Python 3 14 0 beta 2

1.24.10.6 Core and Builtins
...........................

   - gh-127960(1): PyREPL interactive shell no longer starts with
     ‘__package__’ and ‘__file__’ global names set to ‘_pyrepl’ package
     internals.  Contributed by Yuichiro Tachibana.

   - gh-130397(2): Remove special-casing for C stack depth limits for
     WASI. Due to WebAssembly’s built-in stack protection this does not
     pose a security concern.

   - gh-128066(3): Fixes an edge case where PyREPL improperly threw an
     error when Python is invoked on a read only filesystem while trying
     to write history file entries.

   - gh-69605(4): When auto-completing an import in the *note REPL: 492,
     finding no candidates now issues no suggestion, rather than
     suggestions from the current namespace.

   - gh-134158(5): Fix coloring of double braces in f-strings and
     t-strings in the *note REPL: 492.

   - gh-134119(6): Fix crash when calling *note next(): 9da. on an
     exhausted template string iterator.  Patch by Jelle Zijlstra.

   - gh-134100(7): Fix a use-after-free bug that occurs when an imported
     module isn’t in *note sys.modules: 17ce. after its initial import.
     Patch by Nico-Posada.

   - gh-133999(8): Fix *note SyntaxError: 18e. regression in *note
     except: 1ab. parsing after gh-123440(9).

   - gh-133886(10): Fix *note sys.remote_exec(): 16d. for non-ASCII
     paths in non-UTF-8 locales and non-UTF-8 paths in UTF-8 locales.

   - gh-133703(11): Fix hashtable in dict can be bigger than intended in
     some situations.

   - gh-133778(12): Fix bug where assigning to the *note
     __annotations__: 182b. attributes of classes defined under ‘from
     __future__ import annotations’ had no effect.

   - gh-132762(13): *note fromkeys(): 24e. no longer loops forever when
     adding a small set of keys to a large base dict.  Patch by Angela
     Liss.

   - gh-133541(14): Inconsistent indentation in user input crashed the
     new REPL when syntax highlighting was active.  This is now fixed.

   - gh-133516(15): Raise *note ValueError: 2ec. when constants ‘True’,
     ‘False’ or ‘None’ are used as an identifier after NFKC
     normalization.

   - gh-132542(16): Update *note Thread.native_id: c35. after
     ‘fork(2)(17)’ to ensure accuracy.  Patch by Noam Cohen.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127960

   (2) https://github.com/python/cpython/issues/130397

   (3) https://github.com/python/cpython/issues/128066

   (4) https://github.com/python/cpython/issues/69605

   (5) https://github.com/python/cpython/issues/134158

   (6) https://github.com/python/cpython/issues/134119

   (7) https://github.com/python/cpython/issues/134100

   (8) https://github.com/python/cpython/issues/133999

   (9) https://github.com/python/cpython/issues/123440

   (10) https://github.com/python/cpython/issues/133886

   (11) https://github.com/python/cpython/issues/133703

   (12) https://github.com/python/cpython/issues/133778

   (13) https://github.com/python/cpython/issues/132762

   (14) https://github.com/python/cpython/issues/133541

   (15) https://github.com/python/cpython/issues/133516

   (16) https://github.com/python/cpython/issues/132542

   (17) https://manpages.debian.org/fork(2)


File: python.info,  Node: C API<7>,  Next: Build<7>,  Prev: Core and Builtins<20>,  Up: Python 3 14 0 beta 2

1.24.10.7 C API
...............

   - gh-134144(1): Fix crash when calling *note Py_EndInterpreter():
     182d. with a *note thread state: 182e. that isn’t the initial
     thread for the interpreter.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/134144


File: python.info,  Node: Build<7>,  Prev: C API<7>,  Up: Python 3 14 0 beta 2

1.24.10.8 Build
...............

   - gh-134455(1): Fixed ‘build-details.json’ generation to use the
     correct ‘c_api.headers’ as defined in PEP 739(2), instead of
     ‘c_api.include’.

   - gh-131769(3): Fix detecting when the build Python in a cross-build
     is a pydebug build.

   - gh-117088(4): AIX linker don’t support -h option, so avoid it
     through platform check

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/134455

   (2) https://peps.python.org/pep-0739/

   (3) https://github.com/python/cpython/issues/131769

   (4) https://github.com/python/cpython/issues/117088


File: python.info,  Node: Python 3 14 0 beta 1,  Next: Python 3 14 0 alpha 7,  Prev: Python 3 14 0 beta 2,  Up: Changelog

1.24.11 Python 3.14.0 beta 1
----------------------------

'Release date: 2025-05-06'

* Menu:

* Windows: Windows<8>.
* Tools/Demos: Tools/Demos<8>.
* Tests: Tests<6>.
* Security: Security<10>.
* Library: Library<23>.
* IDLE: IDLE<5>.
* Documentation: Documentation<7>.
* Core and Builtins: Core and Builtins<21>.
* Library: Library<24>.
* Core and Builtins: Core and Builtins<22>.
* Library: Library<25>.
* Core and Builtins: Core and Builtins<23>.
* Library: Library<26>.
* C API: C API<8>.
* Build: Build<8>.


File: python.info,  Node: Windows<8>,  Next: Tools/Demos<8>,  Up: Python 3 14 0 beta 1

1.24.11.1 Windows
.................

   - gh-132930(1): Marks the installer for Windows as deprecated and
     updates documentation to cover the new Python install manager.

   - gh-127405(2): Add ‘ABIFLAGS’ to *note sysconfig.get_config_vars():
     298. on Windows.  Patch by Xuehai Pan.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132930

   (2) https://github.com/python/cpython/issues/127405


File: python.info,  Node: Tools/Demos<8>,  Next: Tests<6>,  Prev: Windows<8>,  Up: Python 3 14 0 beta 1

1.24.11.2 Tools/Demos
.....................

   - gh-130453(1): Allow passing multiple keyword arguments with the
     same function name in ‘pygettext’.

   - gh-130195(2): Add warning messages when ‘pygettext’ unimplemented
     ‘-a/--extract-all’ option is called.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/130453

   (2) https://github.com/python/cpython/issues/130195


File: python.info,  Node: Tests<6>,  Next: Security<10>,  Prev: Tools/Demos<8>,  Up: Python 3 14 0 beta 1

1.24.11.3 Tests
...............

   - gh-133131(1): The iOS testbed will now select the most recently
     released «SE-class» device for testing if a device isn’t explicitly
     specified.

   - gh-91048(2): Add ability to externally inspect all pending asyncio
     tasks, even if no task is currently entered on the event loop.

   - gh-109981(3): The test helper that counts the list of open file
     descriptors now uses the optimised ‘/dev/fd’ approach on all Apple
     platforms, not just macOS. This avoids crashes caused by guarded
     file descriptors.

   - gh-132678(4): Add ‘--prioritize’ to ‘-m test’.  This option allows
     the user to specify which selected tests should execute first, even
     if the order is otherwise randomized.  This is particularly useful
     for tests that run the longest.

   - gh-131290(5): Tests in ‘Lib/test’ can now be correctly executed as
     standalone scripts.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/133131

   (2) https://github.com/python/cpython/issues/91048

   (3) https://github.com/python/cpython/issues/109981

   (4) https://github.com/python/cpython/issues/132678

   (5) https://github.com/python/cpython/issues/131290


File: python.info,  Node: Security<10>,  Next: Library<23>,  Prev: Tests<6>,  Up: Python 3 14 0 beta 1

1.24.11.4 Security
..................

   - gh-115322(1): The underlying extension modules behind *note
     readline: bf.:, *note subprocess: dc, and *note ctypes: 2e. now
     raise audit events on previously uncovered code paths that could
     lead to file system access related to C function calling and
     external binary execution.  The ‘ctypes.call_function’ audit hook
     has also been fixed to use an unsigned value for its ‘function
     pointer’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115322


File: python.info,  Node: Library<23>,  Next: IDLE<5>,  Prev: Security<10>,  Up: Python 3 14 0 beta 1

1.24.11.5 Library
.................

   - gh-133490(1): Add color support to PDB in remote mode.

   - gh-132493(2): Avoid eagerly evaluating annotations in functions
     decorated with *note reprlib.recursive_repr(): 13fb.

   - gh-130645(3): Add color to stdlib argparse CLIs.  Patch by Hugo van
     Kemenade.

   - gh-119180(4): Make *note annotationlib.get_annotations(): 459.
     succeed with the ‘FORWARDREF’ format if evaluating the annotations
     throws an exception other than *note NameError: 452. or *note
     AttributeError: 5f0.

   - gh-133351(5): Fix remote PDB to correctly request tab completions
     for Python expressions from the server when completing a
     continuation line of a multi-line Python block.

   - gh-133367(6): Add the ‘--feature-version’, ‘--optimize’, and
     ‘--show-empty’ options to the *note ast: 9. command-line interface.
     Patch by Semyon Moroz.

   - gh-133363(7): The *note cmd.Cmd: 1836. class has been fixed to
     reliably call the ‘completedefault’ method whenever the ‘do_shell’
     method is not defined and tab completion is requested for a line
     beginning with ‘!’.

   - gh-113081(8): Highlight syntax on source code in *note pdb: aa.

   - gh-133349(9): Introduced auto-indent in *note pdb: aa. multi-line
     input.

   - gh-133306(10): Use ‘\z’ instead of ‘\Z’ in *note
     fnmatch.translate(): 1837. and *note glob.translate(): 4fc.

   - gh-133306(11): Support ‘\z’ as a synonym for ‘\Z’ in *note regular
     expressions: be.

   - gh-133300(12): Make *note argparse.ArgumentParser: 1bd.’s
     ‘suggest_on_error’ a keyword-only parameter.  Patch by Hugo van
     Kemenade.

   - gh-133290(13): Fix attribute caching issue when setting *note
     ctypes._Pointer._type_: 1838. in the undocumented and deprecated
     ‘ctypes.SetPointerType()’ function and the undocumented
     ‘set_type()’ method.

   - gh-133223(14): When PDB is attached to a remote process, do a
     better job of intercepting Ctrl+C and forwarding it to the remote
     process.

   - gh-133153(15): Do not complete *note pdb: aa. commands in
     ‘interact’ mode of *note pdb: aa.

   - gh-133139(16): Add the *note curses.assume_default_colors(): 1f6.
     function, a refinement of the *note curses.use_default_colors():
     1f7. function which allows to change the color pair ‘0’.

   - gh-133089(17): Use original timeout value for *note
     subprocess.TimeoutExpired: 1793. when the func *note
     subprocess.run(): d81. is called with a timeout instead of
     sometimes a confusing partial remaining time out value used
     internally on the final ‘wait()’.

   - gh-133036(18): *note codecs.open(): 315. is now deprecated.  Use
     *note open(): 316. instead.  Contributed by Inada Naoki.

   - gh-132987(19): Many builtin and extension functions which accept an
     unsigned integer argument, now use *note __index__(): 19e. if
     available.

   - gh-124703(20): Set return code to ‘1’ when aborting process from
     *note pdb: aa.

   - gh-133005(21): Support passing ‘preset’ option to *note
     tarfile.open(): 1079. when using ‘'w|xz'’ mode.

   - gh-115032(22): Support for custom logging handlers with the 'strm'
     argument is deprecated and scheduled for removal in Python 3.16.
     Define handlers with the 'stream' argument instead.  Patch by
     Mariusz Felisiak.

   - gh-132991(23): Add ‘socket.IP_FREEBIND’ constant on Linux 2.4 and
     later.

   - gh-132995(24): Bump the version of pip bundled in ensurepip to
     version 25.1.1

   - gh-132933(25): The zipapp module now applies the filter when
     creating the list of files to add, rather than waiting until the
     file is being added to the archive.

   - gh-121249(26): Always support the float complex and double complex
     C types in the *note struct: db. module.  Patch by Sergey B
     Kirpichev.

   - gh-132915(27): *note fcntl.fcntl(): 1839. and *note fcntl.ioctl():
     1682. can now detect a buffer overflow and raise *note SystemError:
     796.  The stack and memory can be corrupted in such case, so treat
     this error as fatal.

   - gh-132017(28): Fix error when ‘pyrepl’ is suspended, then resumed
     and terminated.

   - gh-132893(29): Improved *note statistics.NormalDist.cdf(): 183a.
     accuracy for inputs smaller than the mean.

   - gh-130328(30): Speedup pasting in ‘PyREPL’ on Windows.  Fix by
     Chris Eibl.

   - gh-132882(31): Fix copying of *note typing.Union: 2a8. objects
     containing objects that do not support the ‘|’ operator.

   - gh-93696(32): Fixed the breakpoint display error for frozen modules
     in *note pdb: aa.

   - gh-129965(33): Add MIME types for ‘.7z’, ‘.apk’, ‘.deb’, ‘.glb’,
     ‘.gltf’, ‘.gz’, ‘.m4v’, ‘.php’, ‘.rar’, ‘.rpm’, ‘.stl’ and ‘.wmv’.
     Patch by Hugo van Kemenade.

   - gh-132742(34): *note fcntl.fcntl(): 1839. now supports arbitrary
     *note bytes-like objects: 193, not only *note bytes: 192.  *note
     fcntl.ioctl(): 1682. now automatically retries system calls failing
     with EINTR and releases the GIL during a system call even for large
     bytes-like object.

   - gh-132451(35): The CLI for the PDB debugger now accepts a ‘-p PID’
     argument to allow attaching to a running process.  The process must
     be running the same version of Python as the one running PDB.

   - gh-125618(36): Add a 'format' parameter to *note
     annotationlib.ForwardRef.evaluate(): 179a.  Evaluating annotations
     in the ‘FORWARDREF’ format now succeeds in more cases that would
     previously have raised an exception.

   - gh-132805(37): Fix incorrect handling of nested non-constant values
     in the FORWARDREF format in *note annotationlib: 6.

   - gh-132734(38): Add new constants for Bluetooth *note sockets: d1.

   - gh-132673(39): Fix *note AssertionError: 8b9. raised on *note
     ctypes.Structure: 1e5. with ‘_align_ = 0’ and ‘_fields_ = []’.

   - gh-132578(40): Rename the ‘threading.Thread._handle’ field to avoid
     shadowing methods defined on subclasses of ‘threading.Thread’.

   - gh-132561(41): Fix the public ‘locked’ method of
     ‘multiprocessing.SemLock’ class.  Also adding 2 tests for the
     derivated *note multiprocessing.Lock: 183b. and *note
     multiprocessing.RLock: 183c. classes.

   - gh-121468(42): Add *note pdb.set_trace_async(): 279. function to
     support *note await: 18d. statements in *note pdb: aa.

   - gh-132493(43): *note typing.Protocol: 56b. now uses *note
     annotationlib.get_annotations(): 459. when checking whether or not
     an instance implements the protocol with *note isinstance(): 2ad.
     This enables support for ‘isinstance’ checks against classes with
     deferred annotations.

   - gh-132536(44): Do not disable *note PY_THROW: 183d. event in *note
     bdb: 10. because it can’t be disabled.

   - gh-132527(45): Include the valid typecode “w” in the error message
     when an invalid typecode is passed to *note array.array: 4bf.

   - gh-132099(46): The Bluetooth socket with the *note BTPROTO_HCI:
     281. protocol on Linux now accepts an address in the format of an
     integer ‘device_id’, not only a tuple ‘(device_id,)’.

   - gh-81793(47): Fix *note os.link(): 12f7. on platforms (like Linux)
     where the system ‘link()’ function does not follow symlinks.  On
     Linux, it now follows symlinks by default or if
     ‘follow_symlinks=True’ is specified.  On Windows, it now raises an
     error if ‘follow_symlinks=True’ is passed.  On macOS, it now raises
     an error if ‘follow_symlinks=False’ is passed and the system
     ‘linkat()’ function is not available at runtime.

   - gh-132493(48): Support creation of *note typing.Protocol: 56b.
     classes with annotations that cannot be resolved at class creation
     time.

   - gh-132491(49): Rename ‘annotationlib.value_to_string’ to *note
     annotationlib.type_repr(): 183e. and provide better handling for
     function objects.

   - gh-132426(50): Add *note
     annotationlib.get_annotate_from_class_namespace(): 45b. as a helper
     for accessing annotations in metaclasses, and remove
     ‘annotationlib.get_annotate_function’.

   - gh-70145(51): Add support for channels in Bluetooth HCI protocol
     (*note BTPROTO_HCI: 281.).

   - gh-131913(52): Add a shortcut function *note
     multiprocessing.Process.interrupt(): 251. alongside the existing
     *note multiprocessing.Process.terminate(): 183f. and *note
     multiprocessing.Process.kill(): d51. for an improved control over
     child process termination.

   - gh-132439(53): Fix ‘PyREPL’ on Windows: characters entered via
     AltGr are swallowed.  Patch by Chris Eibl.

   - gh-132429(54): Fix support of Bluetooth sockets on NetBSD and
     DragonFly BSD. Add support for 'cid' and 'bdaddr_type' in the
     BTPROTO_L2CAP address on FreeBSD. Return 'cid' in ‘getsockname()’
     for BTPROTO_L2CAP if it is not zero.

   - gh-132106(55): *note QueueListener.start: 243. now raises a *note
     RuntimeError: 244. if the listener is already started.

   - gh-132417(56): Fix a ‘NULL’ pointer dereference when a C function
     called using *note ctypes: 2e. with ‘restype’ *note py_object: 1f3.
     returns ‘NULL’.

   - gh-132385(57): Fix instance error suggestions trigger potential
     exceptions in *note object.__getattr__(): 6fb. in *note traceback:
     104.

   - gh-125866(58): Add optional 'add_scheme' argument to *note
     urllib.request.pathname2url(): 2bf.; when set to true, a complete
     URL is returned.  Likewise add optional 'require_scheme' argument
     to *note url2pathname(): 2bd.; when set to true, a complete URL is
     accepted.

   - gh-132308(59): A *note traceback.TracebackException: 563. now
     correctly renders the ‘__context__’ and ‘__cause__’ attributes from
     *note falsey: 1840. *note Exception: bcf, and the ‘exceptions’
     attribute from falsey *note ExceptionGroup: 4d3.

   - gh-130645(60): Add colour to *note argparse: 7. help output.  Patch
     by Hugo van Kemenade.

   - gh-127495(61): In PyREPL, append a new entry to the
     ‘PYTHON_HISTORY’ file 'after' every statement.  This should
     preserve command-line history after interpreter is terminated.
     Patch by Sergey B Kirpichev.

   - gh-129463(62): Comparison of *note annotationlib.ForwardRef: 175d.
     objects no longer uses the internal ‘__code__’ and ‘__ast_node__’
     attributes, which are used as caches.

   - gh-132250(63): Fixed the *note SystemError: 796. in *note cProfile:
     2b. when locating the actual C function of a method raises an
     exception.

   - gh-132064(64): *note annotationlib.get_annotations(): 459. now uses
     the ‘__annotate__’ attribute if it is present, even if
     ‘__annotations__’ is not present.  Additionally, the function now
     raises a *note TypeError: 198. if it is passed an object that does
     not have any annotatins.

   - gh-130664(65): Support the ‘'_'’ digit separator in formatting of
     the integral part of *note Decimal: 1fe.’s.  Patch by Sergey B
     Kirpichev.

   - gh-131952(66): Add color output to the ‘json’ CLI. Patch by Tomas
     Roun.

   - gh-132063(67): Prevent exceptions that evaluate as falsey (namely,
     when their ‘__bool__’ method returns ‘False’ or their ‘__len__’
     method returns 0) from being ignored by *note
     concurrent.futures.ProcessPoolExecutor: 1d6. and *note
     concurrent.futures.ThreadPoolExecutor: 94a.

   - gh-132106(68): *note logging.handlers.QueueListener: 242. now
     implements the context manager protocol, allowing it to be used in
     a *note with: 186. statement.

   - gh-132054(69): The ‘application/yaml’ mime type ( RFC 9512(70)) is
     now supported by *note mimetypes: 93.  Patch by Sasha «Nelie»
     Chernykh and Hugo van Kemenade.

   - gh-119605(71): Respect ‘follow_wrapped’ for ‘__init__()’ and
     ‘__new__()’ methods when getting the class signature for a class
     with *note inspect.signature(): 22f.  Preserve class signature
     after wrapping with *note warnings.deprecated(): 48a.  Patch by
     Xuehai Pan.

   - gh-118761(72): Improve import times by up to 33x for the *note
     shlex: c9. module, and improve the performance of *note
     shlex.quote(): 582. by up to 12x.  Patch by Adam Turner.

   - gh-85302(73): Add support for *note BTPROTO_SCO: 282. in sockets on
     FreeBSD.

   - gh-131757(74): Make *note functools.lru_cache(): be4. call the
     cached function unlocked to allow concurrency.

   - gh-131423(75): *note ssl: d5. can show descriptions for errors
     added in OpenSSL 3.4.1.  Patch by Bénédikt Tran.

   - gh-131434(76): Improve error reporting for incorrect format in
     *note time.strptime(): 1634.

   - gh-131524(77): Add help message to *note platform: af. command-line
     interface.  Contributed by Harry Lees.

   - gh-100926(78): Move *note ctypes.POINTER(): 1f1. types cache from a
     global internal cache (‘_pointer_type_cache’) to the *note
     ctypes._CData.__pointer_type__: 1f2. attribute of the corresponding
     *note ctypes: 2e. types.  This will stop the cache from growing
     without limits in some situations.

   - gh-85702(79): If ‘zoneinfo._common.load_tzdata’ is given a package
     without a resource a ‘ZoneInfoNotFoundError’ is raised rather than
     a *note IsADirectoryError: 125b.

   - gh-123471(80): Make concurrent iterations over *note
     itertools.repeat: 1841. safe under free-threading.

   - gh-131127(81): Systems using LibreSSL now successfully build.

   - gh-89157(82): Make the pure Python implementation of *note
     datetime.date.fromisoformat(): 829, only accept ASCII strings for
     consistency with the C implementation.

   - gh-130941(83): Fix *note configparser.ConfigParser: 4df. parsing
     empty interpolation with ‘allow_no_value’ set to ‘True’.

   - gh-110067(84): Make *note heapq: 6d. max-heap functions *note
     heapq.heapify_max(): 221, *note heapq.heappush_max(): 222, *note
     heapq.heappop_max(): 223, and *note heapq.heapreplace_max(): 224.
     public.  Previous underscored naming is kept for backwards
     compatibility.  Additionally, the missing function *note
     heapq.heappushpop_max(): 225. has been added to both the C and
     Python implementations.

   - gh-129098(85): Fix REPL traceback reporting when using *note
     compile(): 4b2. with an inexisting file.  Patch by Bénédikt Tran.

   - gh-130631(86): ‘http.cookiejar.join_header_words()’ is now more
     similar to the original Perl version.  It now quotes the same set
     of characters and always quote values that end with ‘"\n"’.

   - gh-130482(87): Add ability to specify name for ‘tkinter.OptionMenu’
     and ‘tkinter.ttk.OptionMenu’.

   - gh-77065(88): Add keyword-only optional argument 'echo_char' for
     *note getpass.getpass(): 21d. for optional visual keyboard feedback
     support.  Patch by Semyon Moroz.

   - gh-130317(89): Fix *note PyFloat_Pack2(): 96a. and *note
     PyFloat_Unpack2(): 96d. for NaN’s with payload.  This corrects
     round-trip for *note struct.unpack(): 1842. and *note
     struct.pack(): 147e. in case of the IEEE 754 binary16 «half
     precision» type.  Patch by Sergey B Kirpichev.

   - gh-130402(90): Joining running daemon threads during interpreter
     shutdown now raises *note PythonFinalizationError: 479.

   - gh-130167(91): Improve speed of *note difflib.IS_LINE_JUNK(): 2d7.
     Patch by Semyon Moroz.

   - gh-101410(92): Added more detailed messages for domain errors in
     the *note math: 92. module.

   - gh-128384(93): Make *note warnings.catch_warnings: 179. use a
     context variable for holding the warning filtering state if the
     *note sys.flags.context_aware_warnings: 18a. flag is set to true.
     This makes using the context manager thread-safe in multi-threaded
     programs.  The flag is true by default in free-threaded builds and
     is otherwise false.  The value of the flag can be overridden by the
     the *note -X context_aware_warnings: 16f. command-line option or by
     the *note PYTHON_CONTEXT_AWARE_WARNINGS: 1843. environment
     variable.

   - gh-129719(94): Fix missing ‘socket.CAN_RAW_ERR_FILTER’ constant in
     the socket module on Linux systems.  It was missing since Python
     3.11.

   - gh-129027(95): Raise *note DeprecationWarning: 1a3. for *note
     sys._clear_type_cache(): 292.  This function was deprecated in
     Python 3.13 but it didn’t raise a runtime warning.

   - gh-128307(96): Add ‘eager_start’ keyword argument to *note
     asyncio.loop.create_task(): 1ca.

   - gh-127604(97): Add support for printing the C stack trace on
     systems that support it via *note faulthandler.dump_c_stack(): 20e.
     or via the 'c_stack' argument in *note faulthandler.enable(): 20f.

   - gh-127385(98): Add the ‘F_DUPFD_QUERY’ constant to the *note fcntl:
     5d. module.

   - gh-126838(99): Add 'resolve_host' keyword-only parameter to *note
     urllib.request.url2pathname(): 2bd, and fix handling of file URLs
     with authorities.

   - gh-82129(100): Fix *note NameError: 452. when calling *note
     typing.get_type_hints(): 8c1. on a *note dataclasses.dataclass():
     4e2. created by *note dataclasses.make_dataclass(): 1844. with
     un-annotated fields.

   - gh-122559(101): Remove ‘__reduce__()’ and ‘__reduce_ex__()’ methods
     that always raise *note TypeError: 198. in the C implementation of
     *note io.FileIO: 1517, *note io.BufferedReader: 1416, *note
     io.BufferedWriter: 15b9. and *note io.BufferedRandom: 15ba. and
     replace them with default ‘__getstate__()’ methods that raise
     ‘TypeError’.  This restores fine details of behavior of Python 3.11
     and older versions.

   - gh-122179(102): *note hashlib.file_digest(): 855. now raises *note
     BlockingIOError: 235. when no data is available during non-blocking
     I/O. Before, it added spurious null bytes to the digest.

   - gh-53032(103): Expose *note decimal.IEEEContext(): 1ff. to support
     creation of contexts corresponding to the IEEE 754 (2008) decimal
     interchange formats.  Patch by Sergey B Kirpichev.

   - gh-120220(104): Deprecate the ‘tkinter.Variable’ methods
     ‘trace_variable()’, ‘trace_vdelete()’ and ‘trace_vinfo()’.  Methods
     ‘trace_add()’, ‘trace_remove()’ and ‘trace_info()’ can be used
     instead.

   - gh-113539(105): *note webbrowser: 11b.: Names in the ‘BROWSER’
     environment variable can now refer to already registered web
     browsers, instead of always generating a new browser command.

     This makes it possible to set ‘BROWSER’ to the value of one of the
     supported browsers on macOS.

   - bpo-44172(106): Keep a reference to original *note curses: 2f.
     windows in subwindows so that the original window does not get
     deleted before subwindows.

   - gh-75223(107): Deprecate undotted extensions in *note
     mimetypes.MimeTypes.add_type(): 319.  Patch by Hugo van Kemenade.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/133490

   (2) https://github.com/python/cpython/issues/132493

   (3) https://github.com/python/cpython/issues/130645

   (4) https://github.com/python/cpython/issues/119180

   (5) https://github.com/python/cpython/issues/133351

   (6) https://github.com/python/cpython/issues/133367

   (7) https://github.com/python/cpython/issues/133363

   (8) https://github.com/python/cpython/issues/113081

   (9) https://github.com/python/cpython/issues/133349

   (10) https://github.com/python/cpython/issues/133306

   (11) https://github.com/python/cpython/issues/133306

   (12) https://github.com/python/cpython/issues/133300

   (13) https://github.com/python/cpython/issues/133290

   (14) https://github.com/python/cpython/issues/133223

   (15) https://github.com/python/cpython/issues/133153

   (16) https://github.com/python/cpython/issues/133139

   (17) https://github.com/python/cpython/issues/133089

   (18) https://github.com/python/cpython/issues/133036

   (19) https://github.com/python/cpython/issues/132987

   (20) https://github.com/python/cpython/issues/124703

   (21) https://github.com/python/cpython/issues/133005

   (22) https://github.com/python/cpython/issues/115032

   (23) https://github.com/python/cpython/issues/132991

   (24) https://github.com/python/cpython/issues/132995

   (25) https://github.com/python/cpython/issues/132933

   (26) https://github.com/python/cpython/issues/121249

   (27) https://github.com/python/cpython/issues/132915

   (28) https://github.com/python/cpython/issues/132017

   (29) https://github.com/python/cpython/issues/132893

   (30) https://github.com/python/cpython/issues/130328

   (31) https://github.com/python/cpython/issues/132882

   (32) https://github.com/python/cpython/issues/93696

   (33) https://github.com/python/cpython/issues/129965

   (34) https://github.com/python/cpython/issues/132742

   (35) https://github.com/python/cpython/issues/132451

   (36) https://github.com/python/cpython/issues/125618

   (37) https://github.com/python/cpython/issues/132805

   (38) https://github.com/python/cpython/issues/132734

   (39) https://github.com/python/cpython/issues/132673

   (40) https://github.com/python/cpython/issues/132578

   (41) https://github.com/python/cpython/issues/132561

   (42) https://github.com/python/cpython/issues/121468

   (43) https://github.com/python/cpython/issues/132493

   (44) https://github.com/python/cpython/issues/132536

   (45) https://github.com/python/cpython/issues/132527

   (46) https://github.com/python/cpython/issues/132099

   (47) https://github.com/python/cpython/issues/81793

   (48) https://github.com/python/cpython/issues/132493

   (49) https://github.com/python/cpython/issues/132491

   (50) https://github.com/python/cpython/issues/132426

   (51) https://github.com/python/cpython/issues/70145

   (52) https://github.com/python/cpython/issues/131913

   (53) https://github.com/python/cpython/issues/132439

   (54) https://github.com/python/cpython/issues/132429

   (55) https://github.com/python/cpython/issues/132106

   (56) https://github.com/python/cpython/issues/132417

   (57) https://github.com/python/cpython/issues/132385

   (58) https://github.com/python/cpython/issues/125866

   (59) https://github.com/python/cpython/issues/132308

   (60) https://github.com/python/cpython/issues/130645

   (61) https://github.com/python/cpython/issues/127495

   (62) https://github.com/python/cpython/issues/129463

   (63) https://github.com/python/cpython/issues/132250

   (64) https://github.com/python/cpython/issues/132064

   (65) https://github.com/python/cpython/issues/130664

   (66) https://github.com/python/cpython/issues/131952

   (67) https://github.com/python/cpython/issues/132063

   (68) https://github.com/python/cpython/issues/132106

   (69) https://github.com/python/cpython/issues/132054

   (70) https://datatracker.ietf.org/doc/html/rfc9512.html

   (71) https://github.com/python/cpython/issues/119605

   (72) https://github.com/python/cpython/issues/118761

   (73) https://github.com/python/cpython/issues/85302

   (74) https://github.com/python/cpython/issues/131757

   (75) https://github.com/python/cpython/issues/131423

   (76) https://github.com/python/cpython/issues/131434

   (77) https://github.com/python/cpython/issues/131524

   (78) https://github.com/python/cpython/issues/100926

   (79) https://github.com/python/cpython/issues/85702

   (80) https://github.com/python/cpython/issues/123471

   (81) https://github.com/python/cpython/issues/131127

   (82) https://github.com/python/cpython/issues/89157

   (83) https://github.com/python/cpython/issues/130941

   (84) https://github.com/python/cpython/issues/110067

   (85) https://github.com/python/cpython/issues/129098

   (86) https://github.com/python/cpython/issues/130631

   (87) https://github.com/python/cpython/issues/130482

   (88) https://github.com/python/cpython/issues/77065

   (89) https://github.com/python/cpython/issues/130317

   (90) https://github.com/python/cpython/issues/130402

   (91) https://github.com/python/cpython/issues/130167

   (92) https://github.com/python/cpython/issues/101410

   (93) https://github.com/python/cpython/issues/128384

   (94) https://github.com/python/cpython/issues/129719

   (95) https://github.com/python/cpython/issues/129027

   (96) https://github.com/python/cpython/issues/128307

   (97) https://github.com/python/cpython/issues/127604

   (98) https://github.com/python/cpython/issues/127385

   (99) https://github.com/python/cpython/issues/126838

   (100) https://github.com/python/cpython/issues/82129

   (101) https://github.com/python/cpython/issues/122559

   (102) https://github.com/python/cpython/issues/122179

   (103) https://github.com/python/cpython/issues/53032

   (104) https://github.com/python/cpython/issues/120220

   (105) https://github.com/python/cpython/issues/113539

   (106) https://bugs.python.org/issue?@action=redirect&bpo=44172

   (107) https://github.com/python/cpython/issues/75223


File: python.info,  Node: IDLE<5>,  Next: Documentation<7>,  Prev: Library<23>,  Up: Python 3 14 0 beta 1

1.24.11.6 IDLE
..............

   - gh-112936(1): fix IDLE: no Shell menu item in single-process mode.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/112936


File: python.info,  Node: Documentation<7>,  Next: Core and Builtins<21>,  Prev: IDLE<5>,  Up: Python 3 14 0 beta 1

1.24.11.7 Documentation
.......................

   - gh-107006(1): Move documentation and example code for *note
     threading.local: 1847. from its docstring to the official docs.

   - gh-125142(2): As part of the builtin help intro text, show the
     keyboard shortcuts for the new, non-basic REPL (F1, F2, and F3).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/107006

   (2) https://github.com/python/cpython/issues/125142


File: python.info,  Node: Core and Builtins<21>,  Next: Library<24>,  Prev: Documentation<7>,  Up: Python 3 14 0 beta 1

1.24.11.8 Core and Builtins
...........................

   - gh-133336(1): ‘-J’ is no longer reserved for use by Jython.  Patch
     by Adam Turner.

   - gh-133261(2): Fix bug where the cycle GC could untrack objects in
     the trashcan because they looked like they were immortal.  When
     objects are added to the trashcan, we take care to ensure they keep
     a mortal reference count.

   - gh-133346(3): Added experimental color theming support to the
     ‘_colorize’ module.

   - gh-132917(4): For the free-threaded build, check the process memory
     usage increase before triggering a full automatic garbage
     collection.  If the memory used has not increased 10% since the
     last collection then defer it.

   - gh-91048(5): Add a new ‘python -m asyncio ps PID’ command-line
     interface to inspect asyncio tasks in a running Python process.
     Displays a flat table of await relationships.  A variant showing a
     tree view is also available as ‘python -m asyncio pstree PID’.
     Both are useful for debugging async code.  Patch by Pablo Galindo,
     Łukasz Langa, Yury Selivanov, and Marta Gomez Macias.

   - gh-133304(6): Workaround NaN’s «canonicalization» in *note
     PyFloat_Pack4(): 96b. and *note PyFloat_Unpack4(): 96e. on RISC-V.

   - gh-133197(7): Improve *note SyntaxError: 18e. error messages for
     incompatible string / bytes prefixes.

   - gh-133231(8): Add new utilities of observing JIT compilation: *note
     sys._jit.is_available(): 44f, *note sys._jit.is_enabled(): 450, and
     *note sys._jit.is_active(): 1849.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/133336

   (2) https://github.com/python/cpython/issues/133261

   (3) https://github.com/python/cpython/issues/133346

   (4) https://github.com/python/cpython/issues/132917

   (5) https://github.com/python/cpython/issues/91048

   (6) https://github.com/python/cpython/issues/133304

   (7) https://github.com/python/cpython/issues/133197

   (8) https://github.com/python/cpython/issues/133231


File: python.info,  Node: Library<24>,  Next: Core and Builtins<22>,  Prev: Core and Builtins<21>,  Up: Python 3 14 0 beta 1

1.24.11.9 Library
.................

   - gh-133194(1): *note ast.parse(): 1c2. will no longer parse new PEP
     758(2) syntax with older 'feature_version' passed.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/133194

   (2) https://peps.python.org/pep-0758/


File: python.info,  Node: Core and Builtins<22>,  Next: Library<25>,  Prev: Library<24>,  Up: Python 3 14 0 beta 1

1.24.11.10 Core and Builtins
............................

   - gh-131798(1): Split ‘CALL_LEN’ into several uops allowing the JIT
     to remove them when optimizing.  Patch by Diego Russo.

   - gh-131798(2): Use ‘sym_new_type’ instead of ‘sym_new_not_null’ for
     _BUILD_STRING, _BUILD_SET

   - gh-132942(3): Fix two races in the type lookup cache.  This
     affected the free-threaded build and could cause crashes
     (apparently quite difficult to trigger).

   - gh-131798(4): Propagate the return type of
     ‘_BINARY_OP_SUBSCR_TUPLE_INT’ in JIT. Patch by Tomas Roun

   - gh-132952(5): Speed up startup with the ‘-S’ argument by importing
     the private ‘_io’ module instead of *note io: 83.  This fixes a
     performance regression introduced earlier in Python 3.14
     development and restores performance to the level of Python 3.13.

   - gh-131798(6): Allow the JIT to remove int guards after ‘_CALL_LEN’
     by setting the return type to int.  Patch by Diego Russo

   - gh-131798(7): Split ‘CALL_TUPLE_1’ into several uops allowing the
     JIT to remove some of them.  Patch by Tomas Roun

   - gh-131798(8): Split ‘CALL_STR_1’ into several uops allowing the JIT
     to remove some of them.  Patch by Tomas Roun

   - gh-132825(9): Enhance unhashable key/element error messages for
     *note dict: 183. and *note set: 184.  Patch by Victor Stinner.

   - gh-131591(10): Reset any PEP 768(11) remote debugging pending call
     in children after *note os.fork(): 4b6. calls.

   - gh-132713(12): Fix ‘repr(list)’ race condition: hold a strong
     reference to the item while calling ‘repr(item)’.  Patch by Victor
     Stinner.

   - gh-132661(13): Implement PEP 750(14) (Template Strings).  Add new
     syntax for t-strings and implement new internal
     ‘string.templatelib.Template’ and
     ‘string.templatelib.Interpolation’ types.

   - gh-132479(15): Fix compiler crash in certain circumstances where
     multiple module-level annotations include comprehensions and other
     nested scopes.

   - gh-132747(16): Fix a crash when calling *note __get__(): 16ef. of a
     *note method: 184c. with a *note None: 886. second argument.

   - gh-132744(17): Certain calls now check for runaway recursion and
     respect the system recursion limit.

   - gh-132449(18): Syntax errors that look like misspellings of Python
     keywords now provide a helpful fix suggestion for the typo.
     Contributed by Pablo Galindo Salgado.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131798

   (2) https://github.com/python/cpython/issues/131798

   (3) https://github.com/python/cpython/issues/132942

   (4) https://github.com/python/cpython/issues/131798

   (5) https://github.com/python/cpython/issues/132952

   (6) https://github.com/python/cpython/issues/131798

   (7) https://github.com/python/cpython/issues/131798

   (8) https://github.com/python/cpython/issues/131798

   (9) https://github.com/python/cpython/issues/132825

   (10) https://github.com/python/cpython/issues/131591

   (11) https://peps.python.org/pep-0768/

   (12) https://github.com/python/cpython/issues/132713

   (13) https://github.com/python/cpython/issues/132661

   (14) https://peps.python.org/pep-0750/

   (15) https://github.com/python/cpython/issues/132479

   (16) https://github.com/python/cpython/issues/132747

   (17) https://github.com/python/cpython/issues/132744

   (18) https://github.com/python/cpython/issues/132449


File: python.info,  Node: Library<25>,  Next: Core and Builtins<23>,  Prev: Core and Builtins<22>,  Up: Python 3 14 0 beta 1

1.24.11.11 Library
..................

   - gh-132737(1): Support profiling code that requires ‘__main__’, such
     as *note pickle: ab.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132737


File: python.info,  Node: Core and Builtins<23>,  Next: Library<26>,  Prev: Library<25>,  Up: Python 3 14 0 beta 1

1.24.11.12 Core and Builtins
............................

   - gh-132639(1): Added *note PyLong_AsNativeBytes(): 606, *note
     PyLong_FromNativeBytes(): 607. and *note
     PyLong_FromUnsignedNativeBytes(): 608. to the limited C API.

   - gh-100239(2): Add specialisation for ‘BINARY_OP/SUBSCR’ on list and
     slice.

   - gh-132508(3): Uses tagged integers on the evaluation stack to
     represent the instruction offsets when reraising an exception.
     This avoids the need to box the integer which could fail in low
     memory conditions.

   - gh-124476(4): Fix decoding from the locale encoding in the C.UTF-8
     locale.

   - gh-131927(5): Compiler warnings originating from the same module
     and line number are now only emitted once, matching the behaviour
     of warnings emitted from user code.  This can also be configured
     with *note warnings: 118. filters.

   - gh-132457(6): Make *note staticmethod(): 453. and *note
     classmethod(): 48f. generic.

   - gh-131798(7): Use ‘sym_new_type’ instead of ‘sym_new_not_null’ for
     _BUILD_LIST, _BUILD_SET, _BUILD_MAP

   - gh-131798(8): Split ‘CALL_TYPE_1’ into several uops allowing the
     JIT to remove some of them.

   - gh-132386(9): Fix crash when passing a dict subclass as the
     ‘globals’ parameter to *note exec(): 4a3.

   - gh-127682(10): No longer call ‘__iter__’ twice when creating and
     executing a generator expression.  Creating a generator expression
     from a non-interable will raise only when the generator expression
     is executed.  This brings the behavior of generator expressions in
     line with other generators.

   - gh-132261(11): The internal storage for annotations and annotate
     functions on classes now uses different keys in the class
     dictionary.  This eliminates various edge cases where access to the
     ‘__annotate__’ and ‘__annotations__’ attributes would behave
     unpredictably.

   - gh-132284(12): Don’t wrap base ‘PyCFunction’ slots on class
     creation if not overridden.

   - gh-130415(13): Improve the JIT’s ability to remove unused constant
     and local variable loads, and fix an issue where deallocating
     unused values could cause JIT code to crash or behave incorrectly.

   - gh-126703(14): Fix possible use after free in cases where a
     method’s definition has the same lifetime as its ‘self’.

   - gh-132286(15): Fix that *note type.__annotate__: 184f. was not
     deleted, when *note type.__annotations__: 182b. was deleted.

   - gh-131798(16): Allow the JIT to remove an extra ‘_TO_BOOL_BOOL’
     instruction after ‘_CONTAINS_OP_DICT’ by setting the return type to
     bool.

   - gh-124715(17): Prevents against stack overflows when calling *note
     Py_DECREF(): 791.  Third-party extension objects no longer need to
     use the «trashcan» mechanism, as protection is now built into the
     *note Py_DECREF(): 791. macro.

   - gh-131798(18): Allow the JIT compiler to remove some type checks
     for operations on lists, tuples, dictionaries, and sets.

   - gh-128398(19): Improve error message when an object supporting the
     synchronous (resp.  asynchronous) context manager protocol is
     entered using *note async with: 185. (resp.  *note with: 186.)
     instead of *note with: 186. (resp.  *note async with: 185.).  Patch
     by Bénédikt Tran.

   - gh-131798(20): Allow the JIT to remove unicode guards after
     ‘_BINARY_OP_SUBSCR_STR_INT’ by setting the return type to string.

   - gh-131878(21): Handle uncaught exceptions in the main input loop
     for the new REPL.

   - gh-131878(22): Fix support of unicode characters with two or more
     codepoints on Windows in the new REPL.

   - gh-126835(23): Move constant folding to the peephole optimizer.
     Rename AST optimization related files (Python/ast_opt.c ->
     Python/ast_preprocess.c), structs (_PyASTOptimizeState ->
     _PyASTPreprocessState) and functions (_PyAST_Optimize ->
     _PyAST_Preprocess, _PyCompile_AstOptimize ->
     _PyCompile_AstPreprocess).

   - gh-114809(24): Add support for macOS multi-arch builds with the JIT
     enabled

   - gh-131507(25): PyREPL now supports syntax highlighting.
     Contributed by Łukasz Langa.

   - gh-130907(26): If the ‘__annotations__’ of a module object are
     accessed while the module is executing, return the annotations that
     have been defined so far, without caching them.

   - gh-130104(27): Three-argument *note pow(): 1a4. now try calling
     *note __rpow__(): 1a5. if necessary.  Previously it was only called
     in two-argument ‘pow()’ and the binary power operator.

   - gh-130070(28): Fixed an assertion error for *note exec(): 4a3.
     passed a string ‘source’ and a non-‘None’ ‘closure’.  Patch by
     Bartosz Sławecki.

   - gh-129958(29): Fix a bug that was allowing newlines inconsistently
     in format specifiers for single-quoted f-strings.  Patch by Pablo
     Galindo.

   - gh-129858(30): ‘elif’ statements that follow an ‘else’ block now
     have a specific error message.

   - gh-69605(31): Add module autocomplete to PyREPL.

   - gh-128555(32): Add the *note sys.flags.thread_inherit_context: 175.
     flag.

        * This flag is set to true by default on the free-threaded build
          and false otherwise.  If the flag is true, starting a new
          thread using *note threading.Thread: 176. will, by default,
          use a copy of the *note contextvars.Context: 177. from the
          caller of *note threading.Thread.start(): 178. rather than
          using an empty context.

        * Add the *note -X thread_inherit_context: 16f. command-line
          option and *note PYTHON_THREAD_INHERIT_CONTEXT: 1850.
          environment variable, which set the *note
          thread_inherit_context: 175. flag.

        * Add the ‘context’ keyword parameter to *note Thread: 176.  It
          can be used to explicitly pass a context value to be used by a
          new thread.

        * Make the ‘_contextvars’ module built-in.

   - gh-123539(33): Improve *note SyntaxError: 18e. message for using
     ‘import ... as’ and ‘from ... import ... as’ with not a name.

   - gh-102567(34): *note -X importtime: 16f. now accepts value ‘2’,
     which indicates that an ‘importtime’ entry should also be printed
     if an imported module has already been loaded.  Patch by Noah Kim
     and Adam Turner.

   - gh-116436(35): Improve error message when *note TypeError: 198.
     occurs during *note dict.update(): 166c.

   - gh-103997(36): String arguments passed to «-c» are now
     automatically dedented as if by *note textwrap.dedent(): 1a9.  This
     allows «python -c» invocations to be indented in shell scripts
     without causing indentation errors.  (Patch by Jon Crall and Steven
     Sun)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132639

   (2) https://github.com/python/cpython/issues/100239

   (3) https://github.com/python/cpython/issues/132508

   (4) https://github.com/python/cpython/issues/124476

   (5) https://github.com/python/cpython/issues/131927

   (6) https://github.com/python/cpython/issues/132457

   (7) https://github.com/python/cpython/issues/131798

   (8) https://github.com/python/cpython/issues/131798

   (9) https://github.com/python/cpython/issues/132386

   (10) https://github.com/python/cpython/issues/127682

   (11) https://github.com/python/cpython/issues/132261

   (12) https://github.com/python/cpython/issues/132284

   (13) https://github.com/python/cpython/issues/130415

   (14) https://github.com/python/cpython/issues/126703

   (15) https://github.com/python/cpython/issues/132286

   (16) https://github.com/python/cpython/issues/131798

   (17) https://github.com/python/cpython/issues/124715

   (18) https://github.com/python/cpython/issues/131798

   (19) https://github.com/python/cpython/issues/128398

   (20) https://github.com/python/cpython/issues/131798

   (21) https://github.com/python/cpython/issues/131878

   (22) https://github.com/python/cpython/issues/131878

   (23) https://github.com/python/cpython/issues/126835

   (24) https://github.com/python/cpython/issues/114809

   (25) https://github.com/python/cpython/issues/131507

   (26) https://github.com/python/cpython/issues/130907

   (27) https://github.com/python/cpython/issues/130104

   (28) https://github.com/python/cpython/issues/130070

   (29) https://github.com/python/cpython/issues/129958

   (30) https://github.com/python/cpython/issues/129858

   (31) https://github.com/python/cpython/issues/69605

   (32) https://github.com/python/cpython/issues/128555

   (33) https://github.com/python/cpython/issues/123539

   (34) https://github.com/python/cpython/issues/102567

   (35) https://github.com/python/cpython/issues/116436

   (36) https://github.com/python/cpython/issues/103997


File: python.info,  Node: Library<26>,  Next: C API<8>,  Prev: Core and Builtins<23>,  Up: Python 3 14 0 beta 1

1.24.11.13 Library
..................

   - gh-89562(1): Remove ‘hostflags’ member from ‘PySSLContext’ struct.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89562


File: python.info,  Node: C API<8>,  Next: Build<8>,  Prev: Library<26>,  Up: Python 3 14 0 beta 1

1.24.11.14 C API
................

   - gh-133166(1): Fix regression where *note PyType_GetModuleByDef():
     635. returns NULL without setting *note TypeError: 198. when a
     static type is passed.

   - gh-133164(2): Add *note
     PyUnstable_Object_IsUniqueReferencedTemporary(): 3c7. function for
     determining if an object exists as a unique temporary variable on
     the interpreter’s stack.  This is a replacement for some cases
     where checking that *note Py_REFCNT(): 2cf. is one is no longer
     sufficient to determine if it’s safe to modify a Python object
     in-place with no visible side effects.

   - gh-133140(3): Add *note PyUnstable_Object_IsUniquelyReferenced():
     3c6. as a replacement for ‘Py_REFNCT(op) == 1’ on *note free
     threaded: 1f4. builds of Python.

   - gh-131747(4): On non-Windows platforms, deprecate using *note
     ctypes.Structure._pack_: 317. to use a Windows-compatible layout on
     non-Windows platforms.  The layout should be specified explicitly
     by setting *note ctypes.Structure._layout_: 1e7. to ‘'ms'’.

   - gh-128972(5): For non-free-threaded builds, the memory layout of
     *note PyASCIIObject: 137d. is reverted to match Python 3.13.  (Note
     that the structure is not part of stable ABI and so its memory
     layout is 'guaranteed' to remain stable.)

   - gh-133079(6): The undocumented APIs ‘Py_C_RECURSION_LIMIT’ and
     ‘PyThreadState.c_recursion_remaining’, added in 3.13, are removed
     without a deprecation period.

   - gh-132987(7): The ‘k’ and ‘K’ formats in *note PyArg_Parse(): 17f6.
     now support the *note __index__(): 19e. special method, like all
     other integer formats.

   - gh-132909(8): Fix an overflow when handling the *note K: 1853.
     format in *note Py_BuildValue(): 3c2.  Patch by Bénédikt Tran.

   - gh-132798(9): Deprecated and undocumented functions
     ‘PyUnicode_AsEncodedObject()’, ‘PyUnicode_AsDecodedObject()’,
     ‘PyUnicode_AsEncodedUnicode()’ and ‘PyUnicode_AsDecodedUnicode()’
     are scheduled for removal in 3.15.

   - gh-132470(10): Creating a *note ctypes.CField: 1e8. with a
     'byte_size' that does not match the actual type size now raises a
     *note ValueError: 2ec. instead of crashing the interpreter.

   - gh-112068(11): [Reverted in gh-136991(12)] Add support of nullable
     arguments in *note PyArg_Parse(): 17f6. and similar functions.
     Adding ‘?’ after any format unit makes ‘None’ be accepted as a
     value.

   - gh-50333(13): Non-tuple sequences are deprecated as argument for
     the ‘(items)’ format unit in *note PyArg_ParseTuple(): 3c1. and
     other *note argument parsing: 3d5. functions if 'items' contains
     format units which store a *note borrowed buffer: 3d6. or a *note
     borrowed reference: 3d7.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/133166

   (2) https://github.com/python/cpython/issues/133164

   (3) https://github.com/python/cpython/issues/133140

   (4) https://github.com/python/cpython/issues/131747

   (5) https://github.com/python/cpython/issues/128972

   (6) https://github.com/python/cpython/issues/133079

   (7) https://github.com/python/cpython/issues/132987

   (8) https://github.com/python/cpython/issues/132909

   (9) https://github.com/python/cpython/issues/132798

   (10) https://github.com/python/cpython/issues/132470

   (11) https://github.com/python/cpython/issues/112068

   (12) https://github.com/python/cpython/issues/136991

   (13) https://github.com/python/cpython/issues/50333


File: python.info,  Node: Build<8>,  Prev: C API<8>,  Up: Python 3 14 0 beta 1

1.24.11.15 Build
................

   - gh-113464(1): Use the cpython-bin-deps «externals» repository for
     Windows LLVM dependency management.  Installing LLVM manually is no
     longer necessary for Windows JIT builds.

   - gh-133183(2): iOS compiler shims now include
     ‘IPHONEOS_DEPLOYMENT_TARGET’ in target triples, ensuring that SDK
     version minimums are honored.

   - gh-133167(3): Fix compilation process with ‘--enable-optimizations’
     and ‘--without-docstrings’.

   - gh-133171(4): Since free-threaded builds do not support the
     experimental JIT compiler, prevent these configurations from being
     combined.

   - gh-132758(5): Fix building with tail call interpreter and pystats.

   - gh-132649(6): The ‘PClayout’ script now allows passing
     ‘--include-tcltk’ on Windows ARM64.

   - gh-132257(7): Change the default LTO flags on GCC to not pass
     ‘-flto-partition=none’, and allow parallelization of LTO. For newer
     GNU makes and GCC, this has a multiple factor speedup for LTO build
     times, with no noticeable loss in performance.

   - gh-132026(8): Fix use of undefined identifiers in platform triplet
     detection on MIPS Linux platforms.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/113464

   (2) https://github.com/python/cpython/issues/133183

   (3) https://github.com/python/cpython/issues/133167

   (4) https://github.com/python/cpython/issues/133171

   (5) https://github.com/python/cpython/issues/132758

   (6) https://github.com/python/cpython/issues/132649

   (7) https://github.com/python/cpython/issues/132257

   (8) https://github.com/python/cpython/issues/132026


File: python.info,  Node: Python 3 14 0 alpha 7,  Next: Python 3 14 0 alpha 6,  Prev: Python 3 14 0 beta 1,  Up: Changelog

1.24.12 Python 3.14.0 alpha 7
-----------------------------

'Release date: 2025-04-08'

* Menu:

* macOS: macOS<3>.
* Windows: Windows<9>.
* Tools/Demos: Tools/Demos<9>.
* Tests: Tests<7>.
* Security: Security<11>.
* Library: Library<27>.
* Documentation: Documentation<8>.
* Core and Builtins: Core and Builtins<24>.
* Library: Library<28>.
* Core and Builtins: Core and Builtins<25>.
* C API: C API<9>.
* Build: Build<9>.


File: python.info,  Node: macOS<3>,  Next: Windows<9>,  Up: Python 3 14 0 alpha 7

1.24.12.1 macOS
...............

   - gh-124111(1): Update macOS installer to use Tcl/Tk 8.6.16.

   - gh-131423(2): Update macOS installer to use OpenSSL 3.0.16.  Patch
     by Bénédikt Tran.

   - gh-131025(3): Update macOS installer to ship with SQLite 3.49.1.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/124111

   (2) https://github.com/python/cpython/issues/131423

   (3) https://github.com/python/cpython/issues/131025


File: python.info,  Node: Windows<9>,  Next: Tools/Demos<9>,  Prev: macOS<3>,  Up: Python 3 14 0 alpha 7

1.24.12.2 Windows
.................

   - gh-131423(1): Update bundled version of OpenSSL to 3.0.16.  The new
     build also disables uplink support, which may be relevant to
     embedders but has no impact on normal use.

   - gh-131453(2): Some ‘SND_*’ and ‘MB_*’ constants are added to *note
     winsound: 11d.

   - gh-91349(3): Replaces our copy of ‘zlib’ with ‘zlib-ng’, for
     performance improvements in *note zlib: 139.

   - gh-131025(4): Update Windows installer to ship with SQLite 3.49.1.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131423

   (2) https://github.com/python/cpython/issues/131453

   (3) https://github.com/python/cpython/issues/91349

   (4) https://github.com/python/cpython/issues/131025


File: python.info,  Node: Tools/Demos<9>,  Next: Tests<7>,  Prev: Windows<9>,  Up: Python 3 14 0 alpha 7

1.24.12.3 Tools/Demos
.....................

   - gh-132121(1): Always escape non-printable Unicode characters in
     ‘pygettext’.

   - gh-131852(2): ‘msgfmt’ no longer adds the ‘POT-Creation-Date’ to
     generated ‘.mo’ files for consistency with GNU ‘msgfmt’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132121

   (2) https://github.com/python/cpython/issues/131852


File: python.info,  Node: Tests<7>,  Next: Security<11>,  Prev: Tools/Demos<9>,  Up: Python 3 14 0 alpha 7

1.24.12.4 Tests
...............

   - gh-131277(1): Allow to unset one or more environment variables at
     once via *note EnvironmentVarGuard.unset(): 185a.  Patch by
     Bénédikt Tran.

   - gh-131050(2): ‘test_ssl.test_dh_params’ is skipped if the
     underlying TLS library does not support finite-field ephemeral
     Diffie-Hellman.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131277

   (2) https://github.com/python/cpython/issues/131050


File: python.info,  Node: Security<11>,  Next: Library<27>,  Prev: Tests<7>,  Up: Python 3 14 0 alpha 7

1.24.12.5 Security
..................

   - gh-131809(1): Update bundled libexpat to 2.7.1

   - gh-131261(2): Upgrade to libexpat 2.7.0

   - gh-121284(3): Fix bug in the folding of rfc2047 encoded-words when
     flattening an email message using a modern email policy.
     Previously when an encoded-word was too long for a line, it would
     be decoded, split across lines, and re-encoded.  But commas and
     other special characters in the original text could be left
     unencoded and unquoted.  This could theoretically be used to spoof
     header lines using a carefully constructed encoded-word if the
     resulting rendered email was transmitted or re-parsed.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131809

   (2) https://github.com/python/cpython/issues/131261

   (3) https://github.com/python/cpython/issues/121284


File: python.info,  Node: Library<27>,  Next: Documentation<8>,  Prev: Security<11>,  Up: Python 3 14 0 alpha 7

1.24.12.6 Library
.................

   - gh-132174(1): Fix function name in error message of
     ‘_interpreters.run_string’.

   - gh-132171(2): Fix crash of ‘_interpreters.run_string’ on string
     subclasses.

   - gh-129204(3): Introduce new ‘_PYTHON_SUBPROCESS_USE_POSIX_SPAWN’
     environment variable knob in *note subprocess: dc. to control the
     use of *note os.posix_spawn(): 52f.

   - gh-132159(4): Do not shadow user arguments in generated ‘__new__()’
     by decorator *note warnings.deprecated: 48a.  Patch by Xuehai Pan.

   - gh-132168(5): The *note ctypes.py_object: 1f3. type now supports
     subscription, making it a *note generic type: 1a1.

   - gh-84481(6): Add the ‘zipfile.ZipFile.data_offset’ attribute, which
     stores the offset to the beginning of ZIP data in a file when
     available.  When the *note zipfile.ZipFile: 8d4. is opened in
     either mode ‘'w'’ or ‘'x'’ and the underlying file does not support
     ‘tell()’, the value will be ‘None’ instead.

   - gh-132075(7): Fix possible use of *note socket: d1. address
     structures with uninitialized members.  Now all structure members
     are initialized with zeroes by default.

   - gh-118761(8): Improve import times by up to 27x for the *note
     string: d8. module.  Patch by Adam Turner.

   - gh-125434(9): Display thread name in *note faulthandler: 5c.  Patch
     by Victor Stinner.

   - gh-132002(10): Fix crash when deallocating *note
     contextvars.ContextVar: 185d. with weird unahashable string names.

   - gh-131938(11): *note xml.etree.ElementTree: 12b.: update the error
     message when an element to remove via *note Element.remove: 185e.
     is not found.  Patch by Bénédikt Tran.

   - gh-115942(12): Add *note threading.RLock.locked(): 1824, *note
     multiprocessing.Lock.locked(): 185f, *note
     multiprocessing.RLock.locked(): 1860, and allow *note
     multiprocessing.managers.SyncManager.Lock(): 159f. and *note
     multiprocessing.managers.SyncManager.RLock(): 15a0. to proxy
     ‘locked()’ call.

   - gh-131974(13): Fix several thread-safety issues in *note ctypes:
     2e. on the *note free threaded: 1f4. build.

   - gh-118761(14): Improve the import time of the *note ast: 9. module
     by extracting the *note unparse(): ae4. function to a helper
     module.

   - gh-107369(15): Improved performance of *note textwrap.indent():
     57d. by an average of ~1.3x.  Patch by Adam Turner.

   - gh-131792(16): Improved performance of *note textwrap.dedent():
     1a9. by an average of ~2.4x, (with improvements of up to 4x for
     large inputs), and fixed a bug where blank lines with whitespace
     characters other than space or horizontal tab were not normalised
     to the newline.  Patch by Adam Turner, Marius Juston, and Pieter
     Eendebak.

   - gh-131668(17): *note socket: d1.: Fix code parsing AF_BLUETOOTH
     socket addresses.

   - gh-60115(18): Support frozen modules for *note linecache.getline():
     240.

   - gh-131492(19): Fix a resource leak when constructing a *note
     gzip.GzipFile: 65c. with a filename fails, for example when passing
     an invalid ‘compresslevel’.

   - gh-131435(20): 10-20% performance improvement of *note
     random.randint(): 1437.

   - gh-131461(21): Fix *note ResourceWarning: 54d. when constructing a
     *note gzip.GzipFile: 65c. in write mode with a broken file object.

   - gh-125866(22): Deprecate the ‘nturl2path’ module.  Call *note
     urllib.request.url2pathname(): 2bd. and *note pathname2url(): 2bf.
     instead.

   - gh-126367(23): Fix issue where *note urllib.request.url2pathname():
     2bd. raised *note OSError: 2c0. when given a Windows URI containing
     a colon character not following a drive letter, such as before an
     NTFS alternate data stream.

   - gh-120144(24): Disable ‘CALL’ event in *note bdb: 10. in
     ‘monitoring’ backend when we don’t need any new events on the code
     object to get a better performance.

   - gh-131358(25): Register ‘cseuckr’ as an encoding alias for
     ‘euc_kr’.

   - gh-131325(26): Fix sendfile fallback implementation to drain data
     after writing to transport in *note asyncio: b.

   - gh-90548(27): *note platform.libc_ver(): 17dd. can now detect and
     report the version of ‘musl’ on Alpine Linux.

   - gh-129843(28): Fix incorrect argument passing in *note
     warnings.warn_explicit(): eff.

   - gh-70647(29): When creating a *note datetime: 34. object with an
     out of range date a more informative error is raised.

   - gh-130914(30): Allow *note graphlib.TopologicalSorter.prepare():
     21f. to be called more than once as long as sorting has not
     started.  Patch by Daniel Pope.

   - gh-131236(31): Allow to generate multiple UUIDs at once via *note
     python -m uuid -count: 2c7.

   - gh-126895(32): Fix *note readline: bf. in *note free-threaded: 1f4.
     build.

   - gh-121468(33): ‘$_asynctask’ is added as a *note pdb: aa.
     convenience variable to access the current asyncio task if
     applicable.

   - gh-118761(34): Improve import time of *note locale: 8a. using lazy
     import ‘re’.  Patch by Semyon Moroz.

   - gh-129598(35): Fix *note ast.unparse(): ae4. when *note
     ast.Interactive: 1861. contains multiple statements.

   - gh-85162(36): The *note http.server: 76. module now includes
     built-in support for HTTPS servers exposed by *note
     http.server.HTTPSServer: 228.  This functionality is exposed by the
     command-line interface (‘python -m http.server’) through the
     ‘--tls-cert’, ‘--tls-key’ and ‘--tls-password-file’ options.  Patch
     by Semyon Moroz.

   - gh-129463(37): The implementations of equality and hashing for
     *note annotationlib.ForwardRef: 175d. now use all attributes on the
     object.  Two ‘ForwardRef’ objects are equal only if all attributes
     are equal.

   - gh-128593(38): *note annotationlib.ForwardRef: 175d. objects no
     longer cache their value when they are successfully evaluated.
     Successive calls to *note annotationlib.ForwardRef.evaluate():
     179a. may return different values.

   - gh-117779(39): Fix reading duplicated entries in *note zipfile:
     137. by name.  Reading duplicated entries (except the last one) by
     ‘ZipInfo’ now emits a warning instead of raising an exception.

   - gh-128715(40): The class of *note Structure: 1e5./*note Union: 1e6.
     field descriptors is now available as *note CField: 1e8, and has
     new attributes to aid debugging and introspection.

   - gh-128055(41): Fix ‘test.test_sysconfig.test_sysconfigdata_json’
     when running outside the build directory (eg.  after installing).

   - gh-126037(42): *note xml.etree.ElementTree: 12b.: Fix a crash in
     *note Element.find: 1862, *note Element.findtext: 1863. and *note
     Element.findall: 1864. when the tag to find implements an *note
     __eq__(): cf4. method mutating the element being queried.  Patch by
     Bénédikt Tran.

   - gh-127794(43): When headers are added to *note
     email.message.Message: 581. objects, either through *note
     email.message.Message.__setitem__(): 1865. or *note
     email.message.Message.add_header(): 1866, the field name is now
     validated according to RFC 5322, Section 2.2(44) and a *note
     ValueError: 2ec. is raised if the field name contains any invalid
     characters.

   - gh-123599(45): Deprecate ‘pathlib.PurePath.as_uri()’; use *note
     pathlib.Path.as_uri(): 31c. instead.

   - gh-126033(46): *note xml.etree.ElementTree: 12b.: Fix a crash in
     *note Element.remove: 185e. when the element is concurrently
     mutated.  Patch by Bénédikt Tran.

   - gh-120144(47): Add the optional backend of ‘sys.monitoring’ to
     *note bdb: 10. and use it for *note pdb: aa.

   - gh-74598(48): Add *note fnmatch.filterfalse(): 211. for excluding
     names matching a pattern.  Patch by Bénédikt Tran.

   - gh-114917(49): Add support for AI_NUMERICSERV in getaddrinfo
     emulation

   - bpo-17254(50): Added aliases for Thai Language using Microsoft Code
     Pages.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132174

   (2) https://github.com/python/cpython/issues/132171

   (3) https://github.com/python/cpython/issues/129204

   (4) https://github.com/python/cpython/issues/132159

   (5) https://github.com/python/cpython/issues/132168

   (6) https://github.com/python/cpython/issues/84481

   (7) https://github.com/python/cpython/issues/132075

   (8) https://github.com/python/cpython/issues/118761

   (9) https://github.com/python/cpython/issues/125434

   (10) https://github.com/python/cpython/issues/132002

   (11) https://github.com/python/cpython/issues/131938

   (12) https://github.com/python/cpython/issues/115942

   (13) https://github.com/python/cpython/issues/131974

   (14) https://github.com/python/cpython/issues/118761

   (15) https://github.com/python/cpython/issues/107369

   (16) https://github.com/python/cpython/issues/131792

   (17) https://github.com/python/cpython/issues/131668

   (18) https://github.com/python/cpython/issues/60115

   (19) https://github.com/python/cpython/issues/131492

   (20) https://github.com/python/cpython/issues/131435

   (21) https://github.com/python/cpython/issues/131461

   (22) https://github.com/python/cpython/issues/125866

   (23) https://github.com/python/cpython/issues/126367

   (24) https://github.com/python/cpython/issues/120144

   (25) https://github.com/python/cpython/issues/131358

   (26) https://github.com/python/cpython/issues/131325

   (27) https://github.com/python/cpython/issues/90548

   (28) https://github.com/python/cpython/issues/129843

   (29) https://github.com/python/cpython/issues/70647

   (30) https://github.com/python/cpython/issues/130914

   (31) https://github.com/python/cpython/issues/131236

   (32) https://github.com/python/cpython/issues/126895

   (33) https://github.com/python/cpython/issues/121468

   (34) https://github.com/python/cpython/issues/118761

   (35) https://github.com/python/cpython/issues/129598

   (36) https://github.com/python/cpython/issues/85162

   (37) https://github.com/python/cpython/issues/129463

   (38) https://github.com/python/cpython/issues/128593

   (39) https://github.com/python/cpython/issues/117779

   (40) https://github.com/python/cpython/issues/128715

   (41) https://github.com/python/cpython/issues/128055

   (42) https://github.com/python/cpython/issues/126037

   (43) https://github.com/python/cpython/issues/127794

   (44) https://datatracker.ietf.org/doc/html/rfc5322.html#section-2.2

   (45) https://github.com/python/cpython/issues/123599

   (46) https://github.com/python/cpython/issues/126033

   (47) https://github.com/python/cpython/issues/120144

   (48) https://github.com/python/cpython/issues/74598

   (49) https://github.com/python/cpython/issues/114917

   (50) https://bugs.python.org/issue?@action=redirect&bpo=17254


File: python.info,  Node: Documentation<8>,  Next: Core and Builtins<24>,  Prev: Library<27>,  Up: Python 3 14 0 alpha 7

1.24.12.7 Documentation
.......................

   - gh-131417(1): Mention *note asyncio.Future: dc8. and *note
     asyncio.Task: 1c7. in generic classes list.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131417


File: python.info,  Node: Core and Builtins<24>,  Next: Library<28>,  Prev: Documentation<8>,  Up: Python 3 14 0 alpha 7

1.24.12.8 Core and Builtins
...........................

   - gh-131798(1): Allow the JIT to remove an extra ‘_TO_BOOL_BOOL’
     instruction after ‘_CONTAINS_OP_SET’ by setting the return type to
     bool.

   - gh-132011(2): Fix crash when calling *note list.append(): 8dd. as
     an unbound method.

   - gh-131998(3): Fix a crash when using an unbound method *note
     descriptor: 1869. object in a function where a bound method
     descriptor was used.

   - gh-131591(4): Implement PEP 768(5) (Safe external debugger
     interface for CPython).  Add a new *note sys.remote_exec(): 16d.
     function to the *note sys: df. module.  This function schedules the
     execution of a Python file in a separate process.  Patch by Pablo
     Galindo, Matt Wozniski and Ivona Stojanovic.

   - gh-131798(6): Allow JIT to omit str guard in truthiness test when
     str type is known.

   - gh-131833(7): Add support for optionally dropping grouping
     parentheses when using multiple exception types as per PEP 758(8).
     Patch by Pablo Galindo

   - gh-130924(9): Usage of a name in a function-scope annotation no
     longer triggers creation of a cell for that variable.  This fixes a
     regression in earlier alphas of Python 3.14.

   - gh-131800(10): Improve the experimental JIT’s ability to remove
     type checks for certain subscripting operations.

   - gh-131738(11): Compiler emits optimized code for builtin
     any/all/tuple calls over a generator expression.

   - gh-131719(12): Fix missing NULL check in ‘_PyMem_FreeDelayed’ in
     *note free-threaded: 1f4. build.

   - gh-131670(13): Fix *note anext(): 9d8. failing on sync *note
     __anext__(): 186a. raising an exception.

   - gh-131666(14): Fix signature of ‘anext_awaitable.close’ objects.
     Patch by Bénédikt Tran.

   - gh-130415(15): Optimize comparison of two constants in JIT builds

   - gh-129149(16): Add fast path for small and medium-size integers in
     *note PyLong_FromInt32(): 3a3, *note PyLong_FromUInt32(): 3a5,
     *note PyLong_FromInt64(): 3a4. and *note PyLong_FromUInt64(): 3a6.
     Patch by Chris Eibl.

   - gh-130887(17): Optimize the AArch64 code generation for the JIT.
     Patch by Diego Russo

   - gh-130956(18): Optimize the AArch64 code generation for the JIT.
     Patch by Diego Russo

   - gh-130928(19): Fix error message when formatting bytes using the
     ‘'i'’ flag.  Patch by Maxim Ageev.

   - gh-130935(20): Annotations at the class and module level that are
     conditionally defined are now only reflected in ‘__annotations__’
     if the block they are in is executed.  Patch by Jelle Zijlstra.

   - gh-130775(21): Do not crash on negative ‘column’ and ‘end_column’
     in *note ast: 9. locations.

   - gh-130704(22): Optimize ‘LOAD_FAST’ and its superinstruction form
     to reduce reference counting overhead.  These instructions are
     replaced with faster variants that load borrowed references onto
     the operand stack when we can prove that the reference in the frame
     outlives the reference loaded onto the stack.

   - gh-88887(23): Fixing multiprocessing Resource Tracker process
     leaking, usually observed when running Python as PID 1.

   - gh-130115(24): Fix an issue with thread identifiers being
     sign-extended on some platforms.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131798

   (2) https://github.com/python/cpython/issues/132011

   (3) https://github.com/python/cpython/issues/131998

   (4) https://github.com/python/cpython/issues/131591

   (5) https://peps.python.org/pep-0768/

   (6) https://github.com/python/cpython/issues/131798

   (7) https://github.com/python/cpython/issues/131833

   (8) https://peps.python.org/pep-0758/

   (9) https://github.com/python/cpython/issues/130924

   (10) https://github.com/python/cpython/issues/131800

   (11) https://github.com/python/cpython/issues/131738

   (12) https://github.com/python/cpython/issues/131719

   (13) https://github.com/python/cpython/issues/131670

   (14) https://github.com/python/cpython/issues/131666

   (15) https://github.com/python/cpython/issues/130415

   (16) https://github.com/python/cpython/issues/129149

   (17) https://github.com/python/cpython/issues/130887

   (18) https://github.com/python/cpython/issues/130956

   (19) https://github.com/python/cpython/issues/130928

   (20) https://github.com/python/cpython/issues/130935

   (21) https://github.com/python/cpython/issues/130775

   (22) https://github.com/python/cpython/issues/130704

   (23) https://github.com/python/cpython/issues/88887

   (24) https://github.com/python/cpython/issues/130115


File: python.info,  Node: Library<28>,  Next: Core and Builtins<25>,  Prev: Core and Builtins<24>,  Up: Python 3 14 0 alpha 7

1.24.12.9 Library
.................

   - gh-99108(1): Add support for built-in implementation of HMAC ( RFC
     2104(2)) based on HACL*.  Patch by Bénédikt Tran.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99108

   (2) https://datatracker.ietf.org/doc/html/rfc2104.html


File: python.info,  Node: Core and Builtins<25>,  Next: C API<9>,  Prev: Library<28>,  Up: Python 3 14 0 alpha 7

1.24.12.10 Core and Builtins
............................

   - gh-130080(1): Implement PEP 765: Disallow return/break/continue
     that exit a finally block.

   - gh-129900(2): Fix return codes inside *note SystemExit: f3e. not
     getting returned by the REPL.

   - gh-128632(3): Disallow ‘__classdict__’ as the name of a type
     parameter.  Using this name would previously crash the interpreter
     in some circumstances.

   - gh-126703(4): Improve performance of builtin methods by using a
     freelist.

   - gh-126703(5): Improve performance of *note range: b3f. by using a
     freelist.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/130080

   (2) https://github.com/python/cpython/issues/129900

   (3) https://github.com/python/cpython/issues/128632

   (4) https://github.com/python/cpython/issues/126703

   (5) https://github.com/python/cpython/issues/126703


File: python.info,  Node: C API<9>,  Next: Build<9>,  Prev: Core and Builtins<25>,  Up: Python 3 14 0 alpha 7

1.24.12.11 C API
................

   - gh-131740(1): Update PyUnstable_GC_VisitObjects to traverse perm
     gen.

   - gh-131525(2): The PyTupleObject now caches the computed hash value
     in the new field ob_hash.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131740

   (2) https://github.com/python/cpython/issues/131525


File: python.info,  Node: Build<9>,  Prev: C API<9>,  Up: Python 3 14 0 alpha 7

1.24.12.12 Build
................

   - gh-131865(1): The DTrace build now properly passes the ‘CC’ and
     ‘CFLAGS’ variables to the ‘dtrace’ command when utilizing SystemTap
     on Linux.

   - gh-131675(2): Fix mimalloc library builds for 32-bit ARM targets.

   - gh-131691(3): clang-cl on Windows needs option ‘/EHa’ to support
     SEH (structured exception handling) correctly.  Fix by Chris Eibl.

   - gh-131278(4): Add optimizing flag ‘WITH_COMPUTED_GOTOS’ to Windows
     builds for when using a compiler that supports it (currently
     clang-cl).  Patch by Chris Eibl.

   - gh-130213(5): Update the vendored HACL* library to fix build issues
     with older clang compilers.

   - gh-130673(6): Fix potential ‘KeyError’ when handling object
     sections during JIT building process.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131865

   (2) https://github.com/python/cpython/issues/131675

   (3) https://github.com/python/cpython/issues/131691

   (4) https://github.com/python/cpython/issues/131278

   (5) https://github.com/python/cpython/issues/130213

   (6) https://github.com/python/cpython/issues/130673


File: python.info,  Node: Python 3 14 0 alpha 6,  Next: Python 3 14 0 alpha 5,  Prev: Python 3 14 0 alpha 7,  Up: Changelog

1.24.13 Python 3.14.0 alpha 6
-----------------------------

'Release date: 2025-03-14'

* Menu:

* macOS: macOS<4>.
* Windows: Windows<10>.
* Tools/Demos: Tools/Demos<10>.
* Tests: Tests<8>.
* Security: Security<12>.
* Library: Library<29>.
* Documentation: Documentation<9>.
* Core and Builtins: Core and Builtins<26>.
* Library: Library<30>.
* Core and Builtins: Core and Builtins<27>.
* Library: Library<31>.
* Core and Builtins: Core and Builtins<28>.
* C API: C API<10>.
* Build: Build<10>.


File: python.info,  Node: macOS<4>,  Next: Windows<10>,  Up: Python 3 14 0 alpha 6

1.24.13.1 macOS
...............

   - gh-128540(1): Ensure web browser is launched by *note
     webbrowser.open(): 1871. on macOS, even for ‘file://’ URLs.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128540


File: python.info,  Node: Windows<10>,  Next: Tools/Demos<10>,  Prev: macOS<4>,  Up: Python 3 14 0 alpha 6

1.24.13.2 Windows
.................

   - gh-131020(1): pylauncher(2) correctly detects a BOM when searching
     for the shebang.  Fix by Chris Eibl.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131020

   (2) https://github.com/python/cpython/tree/3.14/PC/launcher2.c


File: python.info,  Node: Tools/Demos<10>,  Next: Tests<8>,  Prev: Windows<10>,  Up: Python 3 14 0 alpha 6

1.24.13.3 Tools/Demos
.....................

   - gh-130453(1): Make it possible to override default keywords in
     ‘pygettext’.

   - gh-85012(2): Correctly reset ‘msgctxt’ when compiling messages in
     ‘msgfmt’.

   - gh-130453(3): Extend support for specifying custom keywords in
     ‘pygettext’.

   - gh-130195(4): Add warning messages when ‘pygettext’ unimplemented
     ‘-a/--extract-all’ option is called.

   - gh-130057(5): Add support for translator comments in
     ‘pygettext.py’.

   - gh-130025(6): The iOS testbed now correctly handles symlinks used
     as Python framework references.

   - gh-129911(7): Fix the keyword entry in the help output of
     ‘pygettext’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/130453

   (2) https://github.com/python/cpython/issues/85012

   (3) https://github.com/python/cpython/issues/130453

   (4) https://github.com/python/cpython/issues/130195

   (5) https://github.com/python/cpython/issues/130057

   (6) https://github.com/python/cpython/issues/130025

   (7) https://github.com/python/cpython/issues/129911


File: python.info,  Node: Tests<8>,  Next: Security<12>,  Prev: Tools/Demos<10>,  Up: Python 3 14 0 alpha 6

1.24.13.4 Tests
...............

   - gh-129200(1): Multiple iOS testbed runners can now be started at
     the same time without introducing an ambiguity over simulator
     ownership.

   - gh-130292(2): The iOS testbed will now run successfully on a
     machine that has not previously run Xcode tests (such as CI
     configurations).

   - gh-130293(3): The tests of terminal colorization are no longer
     sensitive to the value of the ‘TERM’ variable in the testing
     environment.

   - gh-129401(4): Fix a flaky test in ‘test_repr_rlock’ that checks the
     representation of *note multiprocessing.RLock: 183c.

   - gh-126332(5): Add unit tests for pyrepl.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129200

   (2) https://github.com/python/cpython/issues/130292

   (3) https://github.com/python/cpython/issues/130293

   (4) https://github.com/python/cpython/issues/129401

   (5) https://github.com/python/cpython/issues/126332


File: python.info,  Node: Security<12>,  Next: Library<29>,  Prev: Tests<8>,  Up: Python 3 14 0 alpha 6

1.24.13.5 Security
..................

   - gh-127371(1): Avoid unbounded buffering for
     ‘tempfile.SpooledTemporaryFile.writelines()’.  Previously, disk
     spillover was only checked after the lines iterator had been
     exhausted.  This is now done after each line is written.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127371


File: python.info,  Node: Library<29>,  Next: Documentation<9>,  Prev: Security<12>,  Up: Python 3 14 0 alpha 6

1.24.13.6 Library
.................

   - gh-131204(1): Use monospace font from System Font Stack for
     cross-platform support in *note difflib.HtmlDiff: 201.

   - gh-131196(2): Improve performance of *note uuid.UUID.hex: 1877. and
     *note uuid.UUID.__str__: 831.

   - gh-130940(3): The behavior of ‘PyConfig.use_system_logger’ was
     modified to be enabled by default on iOS. It remains disabled by
     default on macOS.

   - gh-131123(4): Supported completions for attributes of convenience
     variables in *note pdb: aa.

   - gh-93096(5): Removed undocumented CLI ‘python -m difflib’.  Use
     ‘python -m doctest Lib/difflib.py -v’ instead.  Patch by Semyon
     Moroz.

   - gh-93096(6): Removed undocumented ‘-t’ and ‘-v’ arguments of
     ‘python -m pickle’.  Use ‘python -m doctest Lib/pickle.py -v’
     instead.  Patch by Semyon Moroz.

   - gh-81267(7): Correct *note time.sleep(): 8ad. error message when an
     object that cannot be interpreted as an integer or float is
     provided.

   - gh-93096(8): Removed undocumented ‘-t’ and ‘-v’ arguments of
     ‘python -m pickletools’.  Use ‘python -m doctest Lib/pickletools.py
     -v’ instead.  Patch by Semyon Moroz.

   - gh-131045(9): Fix issue with ‘__contains__’, values, and
     pseudo-members for *note enum.Flag: 836.

   - gh-130959(10): Fix pure-Python implementation of *note
     datetime.time.fromisoformat(): 82a. to reject times with spaces in
     fractional part (for example, ‘12:34:56.400 +02:00’), matching the
     C implementation.  Patch by Michał Gorny.

   - gh-130806(11): Deleting *note gzip.GzipFile: 65c. before it is
     closed now emits a *note ResourceWarning: 54d.

   - gh-130637(12): Add validation for numeric response data in
     poplib.POP3.stat() method

   - gh-130665(13): Only apply locale to *note calendar CLI: 1d0. when
     set via ‘--locale’ and not via ‘LANG’ environment variable.

   - gh-130660(14): ‘sys.ps1’ and ‘sys.ps2’ are now restored after *note
     code.interact(): 1878. call.

   - gh-130608(15): Remove 'dirs_exist_ok' argument from *note
     pathlib.Path.copy(): 267. and *note copy_into(): 268.  These
     methods are new in Python 3.14.

   - gh-130461(16): Remove ‘.. index::’ directives from the *note uuid:
     116. module documentation.  These directives previously created
     entries in the general index for *note getnode(): da2. as well as
     the *note uuid1(): da3, *note uuid3(): 2e5, *note uuid4(): 2e7,
     *note uuid5(): 2e6, and *note uuid8(): 2c4. constructor functions.

   - gh-130379(17): The zipapp module now calculates the list of files
     to be added to the archive before creating the archive.  This
     avoids accidentally including the target when it is being created
     in the source directory.

   - gh-82987(18): Inline breakpoints like *note breakpoint(): 271. or
     *note pdb.set_trace(): 272. will always stop the program at calling
     frame, ignoring the ‘skip’ pattern (if any).

   - gh-125377(19): ‘<tab>’ at the beginning of the line in *note pdb:
     aa. multi-line input will fill in a 4-space indentation now,
     instead of inserting a ‘\t’ character.

   - gh-125413(20): Ensure the path returned from *note
     pathlib.Path.copy(): 267. or *note move(): 269. has fresh *note
     info: 26b.

   - gh-65697(21): stdlib configparser will now attempt to validate that
     keys it writes will not result in file corruption (creating a file
     unable to be accurately parsed by a future read() call from the
     same parser).  Attempting a corrupting write() will raise an
     InvalidWriteError.

   - gh-125413(22): Speed up *note Path.copy: 267. by making better use
     of *note info: 26b. internally.

   - gh-130285(23): Fix corner case for *note random.sample(): 94e.
     allowing the 'counts' parameter to specify an empty population.  So
     now, ‘sample([], 0, counts=[])’ and ‘sample('abc', k=0, counts=[0,
     0, 0])’ both give the same result as ‘sample([], 0)’.

   - gh-124703(24): Executing ‘quit’ command in *note pdb: aa. will
     raise *note bdb.BdbQuit: 278. when *note pdb: aa. is started from
     an interactive console using *note breakpoint(): 271. or *note
     pdb.set_trace(): 272.

   - gh-107773(25): Make *note datetime: 34. subclass *note __repr__():
     830. consistent both implementations.  Patch by Semyon Moroz.

   - gh-130250(26): Fix regression in ‘traceback.print_last()’.

   - gh-123471(27): Make concurrent iterations over *note
     itertools.batched: 512. safe under free-threading.

   - gh-57537(28): Support breakpoints for *note zipimport: 138. modules
     on *note pdb: aa.

   - gh-130230(29): Fix crash in *note pow(): 1a4. with only *note
     Decimal: 1fe. third argument.

   - gh-126944(30): Show explicit errors when required arguments of
     *note pdb: aa. commands are missing

   - gh-127750(31): Improve repr of *note
     functools.singledispatchmethod: be5. methods and descriptors.

   - gh-128520(32): Apply type conversion consistently in *note
     pathlib.PurePath: 6ce. and *note Path: 266. methods can accept a
     path object as an argument, such as *note match(): 6d4. and *note
     rename(): 1879.  The argument is now converted to path object if it
     lacks a *note with_segments(): 6cf. attribute, and not otherwise.

   - gh-118761(33): Reverts a change in the previous release attempting
     to make some stdlib imports used within the *note subprocess: dc.
     module lazy as this was causing errors during ‘__del__’ finalizers
     calling methods such as ‘terminate’, or ‘kill’, or ‘send_signal’.

   - gh-130164(34): Fixed failure to raise *note TypeError: 198. in
     *note inspect.Signature.bind(): 187a. for positional-only arguments
     provided by keyword when a variadic keyword argument (e.g.
     ‘**kwargs’) is present.

   - gh-130151(35): Fix reference leaks in ‘_hashlib.hmac_new()’ and
     ‘_hashlib.hmac_digest()’.  Patch by Bénédikt Tran.

   - gh-130145(36): Fix ‘asyncio.AbstractEventloop.run_forever()’ when
     another loop is already running.

   - gh-130139(37): Fix bug where *note ast.parse(): 1c2. did not error
     on AST input which is not of the correct type, when called with
     optimize=False.

   - gh-127260(38): Forbid the use of colon («:») as a fractional
     component separator and other improvements to the consistency of
     error raising between the C and Python implementations of *note
     datetime.time.fromisoformat(): 82a. and *note
     datetime.datetime.fromisoformat(): 82b.  Patch by Semyon Moroz.

   - gh-85795(39): Using *note super(): 1a6. and ‘__class__’ *note
     closure variable: 187b. in user-defined methods of *note
     typing.NamedTuple: 331. subclasses is now explicitly prohibited at
     runtime.  Contributed by Bartosz Sławecki in gh-130082(40).

   - gh-118761(41): Improve import time of *note cmd: 1a. by lazy
     importing *note inspect: 82. and removing *note string: d8.  Patch
     by Semyon Moroz.

   - gh-129726(42): Fix *note gzip.GzipFile: 65c. raising an unraisable
     exception during garbage collection when referring to a temporary
     object by breaking the reference loop with *note weakref: 11a.

   - gh-127750(43): Remove broken *note
     functools.singledispatchmethod(): be5. caching introduced in
     gh-85160(44).  Achieve the same performance using different
     optimization.

   - gh-129948(45): Add support for shared *note set: 184. to *note
     multiprocessing.managers.SyncManager: 187c. via *note
     SyncManager.set(): 24f.

   - gh-129965(46): Update MIME types for ‘.avi’ and ‘.wav’.  Add MIME
     types for ‘.docx’, ‘.pptx’, ‘.xlsx’, ‘.epub’, ‘.flac’, ‘.m4a’,
     ‘.odg’, ‘.odp’, ‘.ods’, ‘.odt’, ‘.oga’, ‘.ogg’, ‘.ogx’ and ‘.weba’.
     Patch by Hugo van Kemenade.

   - gh-129889(47): Support context manager protocol by *note
     contextvars.Token: 1e2.  Patch by Andrew Svetlov.

   - gh-97850(48): Update the deprecation warning of *note
     importlib.abc.Loader.load_module(): a6b.

   - gh-129678(49): *note configparser.ConfigParser: 4df.: do not write
     an empty unnamed section

   - gh-128641(50): Restore *note configparser.ConfigParser.read():
     166f. performance.

   - gh-129569(51): Fix *note unicodedata.normalize(): 8e5. to always
     return a built-in *note str: 169. object when given an input of a
     *note str: 169. subclass, regardless of whether the string is
     already normalized.

   - gh-128231(52): Execution of multiple statements in the new REPL now
     stops immediately upon the first exception encountered.  Patch by
     Bartosz Sławecki.

   - gh-96092(53): Fix bug in *note traceback.walk_stack(): 1083. called
     with None where it was skipping more frames than in prior versions.
     This bug fix also changes walk_stack to walk the stack in the frame
     where it was called rather than where it first gets used.

   - gh-129288(54): Add optional ‘l2_cid’ and ‘l2_bdaddr_type’ fields to
     *note socket: d1. ‘BTPROTO_L2CAP’ sockaddr tuple.

   - gh-128703(55): Fix *note mimetypes.guess_type(): 518. to use
     default mapping for empty ‘Content-Type’ in registry.

   - gh-128647(56): Eagerly write to buffers passed to *note
     gzip.GzipFile: 65c.’s *note readinto(): 187d. and *note
     readinto1(): 101e. implementations, avoiding unnecessary
     allocations.  Patch by Chris Markiewicz.

   - gh-128184(57): Improve display of *note annotationlib.ForwardRef:
     175d. object within *note inspect.Signature: 4e4. representations.
     This also fixes a *note NameError: 452. that was raised when using
     *note dataclasses.dataclass(): 4e2. on classes with unresolvable
     forward references.

   - gh-128041(58): Add *note
     concurrent.futures.ProcessPoolExecutor.terminate_workers(): 1da.
     and *note concurrent.futures.ProcessPoolExecutor.kill_workers():
     1db. as ways to terminate or kill all living worker processes in
     the given pool.  (Contributed by Charles Machalow in
     gh-130849(59).)

   - gh-127647(60): Add protocols *note io.Reader: 236. and *note
     io.Writer: 237. as alternatives to *note typing.IO: 238, *note
     typing.TextIO: 239, and *note typing.BinaryIO: 23a.

   - gh-109798(61): Added additional information into error messages in
     *note datetime: 34, and made the messages more consistent between
     the C and Python implementations.  Patch by Semyon Moroz.

   - gh-125746(62): Delay deprecated *note
     zipimport.zipimporter.load_module(): 338. removal time to 3.15.
     Use *note zipimport.zipimporter.exec_module(): 339. instead.

   - gh-74028(63): Add the optional ‘buffersize’ parameter to *note
     concurrent.futures.Executor.map(): 1dc. to limit the number of
     submitted tasks whose results have not yet been yielded.  If the
     buffer is full, iteration over the 'iterables' pauses until a
     result is yielded from the buffer.

   - gh-124927(64): Non-printing characters are now properly handled in
     the new REPL.

   - gh-124096(65): Turn on virtual terminal mode and enable bracketed
     paste in REPL on Windows console.  (If the terminal does not
     support bracketed paste, enabling it does nothing.)

   - gh-89083(66): Add *note uuid.uuid7(): 2c3. for generating UUIDv7
     objects as specified in RFC 9562(67).  Patch by Bénédikt Tran.

   - gh-89083(68): Add *note uuid.uuid6(): 2c2. for generating UUIDv6
     objects as specified in RFC 9562(69).  Patch by Bénédikt Tran.

   - gh-117151(70): Increase ‘io.DEFAULT_BUFFER_SIZE’ from 8k to 128k
     and adjust *note open(): 316. on platforms where *note os.fstat():
     f8e. provides a ‘st_blksize’ field (such as Linux) to use
     ‘max(min(blocksize, 8 MiB), io.DEFAULT_BUFFER_SIZE)’ rather than
     always using the device block size.  This should improve I/O
     performance.  Patch by Romain Morotti.

   - gh-105499(71): Make *note types.UnionType: 2a7. an alias for *note
     typing.Union: 2a8.  Both ‘int | str’ and ‘Union[int, str]’ now
     create instances of the same type.  Patch by Jelle Zijlstra.

   - gh-93096(72): Document the command-line for *note mimetypes: 93.
     It now exits with ‘1’ on failure instead of ‘0’ and ‘2’ on
     incorrect command-line parameters instead of ‘1’.  Also, errors are
     printed to stderr instead of stdout and their text is made tighter.
     Patch by Oleg Iarygin and Hugo van Kemenade.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131204

   (2) https://github.com/python/cpython/issues/131196

   (3) https://github.com/python/cpython/issues/130940

   (4) https://github.com/python/cpython/issues/131123

   (5) https://github.com/python/cpython/issues/93096

   (6) https://github.com/python/cpython/issues/93096

   (7) https://github.com/python/cpython/issues/81267

   (8) https://github.com/python/cpython/issues/93096

   (9) https://github.com/python/cpython/issues/131045

   (10) https://github.com/python/cpython/issues/130959

   (11) https://github.com/python/cpython/issues/130806

   (12) https://github.com/python/cpython/issues/130637

   (13) https://github.com/python/cpython/issues/130665

   (14) https://github.com/python/cpython/issues/130660

   (15) https://github.com/python/cpython/issues/130608

   (16) https://github.com/python/cpython/issues/130461

   (17) https://github.com/python/cpython/issues/130379

   (18) https://github.com/python/cpython/issues/82987

   (19) https://github.com/python/cpython/issues/125377

   (20) https://github.com/python/cpython/issues/125413

   (21) https://github.com/python/cpython/issues/65697

   (22) https://github.com/python/cpython/issues/125413

   (23) https://github.com/python/cpython/issues/130285

   (24) https://github.com/python/cpython/issues/124703

   (25) https://github.com/python/cpython/issues/107773

   (26) https://github.com/python/cpython/issues/130250

   (27) https://github.com/python/cpython/issues/123471

   (28) https://github.com/python/cpython/issues/57537

   (29) https://github.com/python/cpython/issues/130230

   (30) https://github.com/python/cpython/issues/126944

   (31) https://github.com/python/cpython/issues/127750

   (32) https://github.com/python/cpython/issues/128520

   (33) https://github.com/python/cpython/issues/118761

   (34) https://github.com/python/cpython/issues/130164

   (35) https://github.com/python/cpython/issues/130151

   (36) https://github.com/python/cpython/issues/130145

   (37) https://github.com/python/cpython/issues/130139

   (38) https://github.com/python/cpython/issues/127260

   (39) https://github.com/python/cpython/issues/85795

   (40) https://github.com/python/cpython/issues/130082

   (41) https://github.com/python/cpython/issues/118761

   (42) https://github.com/python/cpython/issues/129726

   (43) https://github.com/python/cpython/issues/127750

   (44) https://github.com/python/cpython/issues/85160

   (45) https://github.com/python/cpython/issues/129948

   (46) https://github.com/python/cpython/issues/129965

   (47) https://github.com/python/cpython/issues/129889

   (48) https://github.com/python/cpython/issues/97850

   (49) https://github.com/python/cpython/issues/129678

   (50) https://github.com/python/cpython/issues/128641

   (51) https://github.com/python/cpython/issues/129569

   (52) https://github.com/python/cpython/issues/128231

   (53) https://github.com/python/cpython/issues/96092

   (54) https://github.com/python/cpython/issues/129288

   (55) https://github.com/python/cpython/issues/128703

   (56) https://github.com/python/cpython/issues/128647

   (57) https://github.com/python/cpython/issues/128184

   (58) https://github.com/python/cpython/issues/128041

   (59) https://github.com/python/cpython/issues/130849

   (60) https://github.com/python/cpython/issues/127647

   (61) https://github.com/python/cpython/issues/109798

   (62) https://github.com/python/cpython/issues/125746

   (63) https://github.com/python/cpython/issues/74028

   (64) https://github.com/python/cpython/issues/124927

   (65) https://github.com/python/cpython/issues/124096

   (66) https://github.com/python/cpython/issues/89083

   (67) https://datatracker.ietf.org/doc/html/rfc9562.html

   (68) https://github.com/python/cpython/issues/89083

   (69) https://datatracker.ietf.org/doc/html/rfc9562.html

   (70) https://github.com/python/cpython/issues/117151

   (71) https://github.com/python/cpython/issues/105499

   (72) https://github.com/python/cpython/issues/93096


File: python.info,  Node: Documentation<9>,  Next: Core and Builtins<26>,  Prev: Library<29>,  Up: Python 3 14 0 alpha 6

1.24.13.7 Documentation
.......................

   - gh-125722(1): Require Sphinx 8.2.0 or later to build the Python
     documentation.  Patch by Adam Turner.

   - gh-129712(2): The wheel tags supported by each macOS universal SDK
     option are now documented.

   - gh-46236(3): C API: Document *note PyUnicode_RSplit(): 187f, *note
     PyUnicode_Partition(): 1880. and *note PyUnicode_RPartition():
     1881.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/125722

   (2) https://github.com/python/cpython/issues/129712

   (3) https://github.com/python/cpython/issues/46236


File: python.info,  Node: Core and Builtins<26>,  Next: Library<30>,  Prev: Documentation<9>,  Up: Python 3 14 0 alpha 6

1.24.13.8 Core and Builtins
...........................

   - gh-131141(1): Fix data race in *note sys.monitoring: e0.
     instrumentation while registering callback.

   - gh-130804(2): Fix support of unicode characters on Windows in the
     new REPL.

   - gh-130932(3): Fix incorrect exception handling in
     ‘_PyModule_IsPossiblyShadowing’

   - gh-122029(4): *note sys.setprofile(): 1705. and *note
     sys.settrace(): 2e1. will not generate a ‘c_call’ event for
     ‘INSTRUMENTED_CALL_FUNCTION_EX’ if the callable is a method with a
     C function wrapped, because we do not generate ‘c_return’ event in
     such case.

   - gh-129964(5): Fix JIT crash on Windows on Arm.  Patch by Diego
     Russo and Brandt Bucher.

   - gh-130851(6): Fix a crash in the *note free threading: 1f4. build
     when constructing a *note code: 1b. object with *note co_consts:
     1883. that contains instances of types that are not otherwise
     generated by the bytecode compiler.

   - gh-128534(7): Ensure that both left and right branches have the
     same source for ‘async for’ loops.  Add these branches to the
     ‘co_branches()’ iterator.

   - gh-130794(8): Fix memory leak in the *note free threaded: 1f4.
     build when resizing a shared list or dictionary from multiple
     short-lived threads.

   - gh-130415(9): Improve JIT understanding of integers in boolean
     context.

   - gh-130382(10): Fix ‘PyRefTracer_DESTROY’ not being sent from
     ‘Python/ceval.c’ ‘Py_DECREF()’.

   - gh-130574(11): Renumber *note RESUME: 5bb. from 149 to 128.

   - gh-124878(12): Fix race conditions during runtime finalization that
     could lead to accessing freed memory.

   - gh-130415(13): Improve the experimental JIT’s ability to narrow
     boolean values based on the results of truthiness tests.

   - gh-130618(14): Fix a bug that was causing ‘UnicodeDecodeError’ or
     ‘SystemError’ to be raised when using f-strings with ‘lambda’
     expressions with non-ASCII characters.  Patch by Pablo Galindo

   - gh-123044(15): Make sure that the location of branch targets in
     ‘match’ cases is in the body, not the pattern.

   - gh-128534(16): Add branch monitoring (‘BRANCH_LEFT’ and
     ‘BRANCH_RIGHT’ events) for ‘async for’ loops.

   - gh-130163(17): Fix possible crashes related to concurrent change
     and use of the *note sys: df. module attributes.

   - gh-122029(18): ‘INSTRUMENTED_CALL_KW’ will expand the method before
     monitoring to reflect the actual behavior more accurately.

   - gh-130415(19): Improve JIT’s ability to optimize strings in boolean
     contexts.

   - gh-130396(20): Use actual stack limits (from
     ‘pthread_getattr_np(3)(21)’) for linux, and other systems with
     ‘_GNU_SOURCE’ defined, when determining limits for C stack
     protection.

   - gh-128396(22): Fix a crash that occurs when calling *note locals():
     46f. inside an inline comprehension that uses the same local
     variable as the outer frame scope where the variable is a free or
     cell var.

   - gh-129107(23): Fix two more *note bytearray: 344. functions for
     *note free threading: 1f4.

   - gh-127705(24): Use tagged references (‘_PyStackRef’) for the
     default build as well as for the free-threading build.  This has a
     small negative performance impact short-term but will enable larger
     speedups in the future and significantly reduce maintenance costs
     by allowing a single implementation of tagged references in the
     future.

   - gh-130094(25): Fix two race conditions involving concurrent imports
     that could lead to spurious failures with *note
     ModuleNotFoundError: d3f.

   - gh-129107(26): Make *note bytearray: 344. iterator safe under *note
     free threading: 1f4.

   - gh-115802(27): Use the more efficient «medium» code model for
     JIT-compiled code on supported platforms.

   - gh-107956(28): A ‘build-details.json’ file is now install in the
     platform-independent standard library directory ( PEP 739(29)
     implementation).

   - gh-116042(30): Fix location for SyntaxErrors of invalid escapes in
     the tokenizer.  Patch by Pablo Galindo

   - gh-91079(31): Change C stack overflow protection to consider the
     amount of stack consumed, rather than a counter.  This allows
     deeper recursion in many cases, but remains safe.

   - gh-129715(32): Improve the experimental JIT’s handling of returns
     to unknown callers.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131141

   (2) https://github.com/python/cpython/issues/130804

   (3) https://github.com/python/cpython/issues/130932

   (4) https://github.com/python/cpython/issues/122029

   (5) https://github.com/python/cpython/issues/129964

   (6) https://github.com/python/cpython/issues/130851

   (7) https://github.com/python/cpython/issues/128534

   (8) https://github.com/python/cpython/issues/130794

   (9) https://github.com/python/cpython/issues/130415

   (10) https://github.com/python/cpython/issues/130382

   (11) https://github.com/python/cpython/issues/130574

   (12) https://github.com/python/cpython/issues/124878

   (13) https://github.com/python/cpython/issues/130415

   (14) https://github.com/python/cpython/issues/130618

   (15) https://github.com/python/cpython/issues/123044

   (16) https://github.com/python/cpython/issues/128534

   (17) https://github.com/python/cpython/issues/130163

   (18) https://github.com/python/cpython/issues/122029

   (19) https://github.com/python/cpython/issues/130415

   (20) https://github.com/python/cpython/issues/130396

   (21) https://manpages.debian.org/pthread_getattr_np(3)

   (22) https://github.com/python/cpython/issues/128396

   (23) https://github.com/python/cpython/issues/129107

   (24) https://github.com/python/cpython/issues/127705

   (25) https://github.com/python/cpython/issues/130094

   (26) https://github.com/python/cpython/issues/129107

   (27) https://github.com/python/cpython/issues/115802

   (28) https://github.com/python/cpython/issues/107956

   (29) https://peps.python.org/pep-0739/

   (30) https://github.com/python/cpython/issues/116042

   (31) https://github.com/python/cpython/issues/91079

   (32) https://github.com/python/cpython/issues/129715


File: python.info,  Node: Library<30>,  Next: Core and Builtins<27>,  Prev: Core and Builtins<26>,  Up: Python 3 14 0 alpha 6

1.24.13.9 Library
.................

   - gh-129983(1): Fix data race in compile_template in ‘sre.c’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129983


File: python.info,  Node: Core and Builtins<27>,  Next: Library<31>,  Prev: Library<30>,  Up: Python 3 14 0 alpha 6

1.24.13.10 Core and Builtins
............................

   - gh-129967(1): Fix a race condition in the *note free threading:
     1f4. build when ‘repr(set)’ is called concurrently with
     ‘set.clear()’.

   - gh-129953(2): The internal (evaluation) stack is now spilled to
     memory whenever execution escapes from the interpreter or JIT
     compiled code.  This should have no observable effect in either
     Python or builtin extensions, but will allow various important
     optimizations in the future.

   - gh-129515(3): Clarify syntax error messages for conditional
     expressions when a statement is specified before an *note if: 181.
     or after an *note else: 17c. keyword.

   - gh-129349(4): *note bytes.fromhex(): 190. and *note
     bytearray.fromhex(): 191. now accepts ASCII *note bytes: 192. and
     *note bytes-like objects: 193.

   - gh-129149(5): Add fast path for medium-size integers in *note
     PyLong_FromSsize_t(): 1886.  Patch by Chris Eibl.

   - gh-129107(6): Make the *note bytearray: 344. safe under *note free
     threading: 1f4.

   - gh-128974(7): Fix a crash in *note UnicodeError.__str__: 831. when
     custom attributes implement *note __str__(): 831. with
     side-effects.  Patch by Bénédikt Tran.

   - gh-126085(8): *note typing.TypeAliasType: 2ae. now supports star
     unpacking.

   - gh-125331(9): ‘from __future__ import barry_as_FLUFL’ now works in
     more contexts, including when it is used in files, with the ‘-c’
     flag, and in the REPL when there are multiple statements on the
     same line.  Previously, it worked only on subsequent lines in the
     REPL, and when the appropriate flags were passed directly to *note
     compile(): 4b2.  Patch by Pablo Galindo.

   - gh-121464(10): Make concurrent iterations over the same *note
     enumerate(): 1688. iterator safe under free-threading.  See
     Strategy for Iterators in Free Threading(11).

   - gh-87790(12): Support underscore and comma as thousands separators
     in the fractional part for floating-point presentation types of the
     new-style string formatting (with *note format(): 199. or *note
     f-strings: 19a.).  Patch by Sergey B Kirpichev.

   - gh-124445(13): Fix specialization of generic aliases that are
     generic over a *note typing.ParamSpec: 488. and have been
     specialized with a nested type variable.

   - gh-120608(14): Adapt *note reversed(): a67. for use in the
     free-threading build.  The *note reversed(): a67. is still not
     thread-safe in the sense that concurrent iterations may see the
     same object, but they will not corrupt the interpreter state.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129967

   (2) https://github.com/python/cpython/issues/129953

   (3) https://github.com/python/cpython/issues/129515

   (4) https://github.com/python/cpython/issues/129349

   (5) https://github.com/python/cpython/issues/129149

   (6) https://github.com/python/cpython/issues/129107

   (7) https://github.com/python/cpython/issues/128974

   (8) https://github.com/python/cpython/issues/126085

   (9) https://github.com/python/cpython/issues/125331

   (10) https://github.com/python/cpython/issues/121464

   (11) https://github.com/python/cpython/issues/124397

   (12) https://github.com/python/cpython/issues/87790

   (13) https://github.com/python/cpython/issues/124445

   (14) https://github.com/python/cpython/issues/120608


File: python.info,  Node: Library<31>,  Next: Core and Builtins<28>,  Prev: Core and Builtins<27>,  Up: Python 3 14 0 alpha 6

1.24.13.11 Library
..................

   - gh-100388(1): Fix the ‘platform._sys_version()’ method when
     ‘__DATE__’ is undefined at buildtime by changing default buildtime
     datetime string to the UNIX epoch.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100388


File: python.info,  Node: Core and Builtins<28>,  Next: C API<10>,  Prev: Library<31>,  Up: Python 3 14 0 alpha 6

1.24.13.12 Core and Builtins
............................

   - bpo-44369(1): Improve syntax errors for incorrectly closed strings.
     Patch by Pablo Galindo

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44369


File: python.info,  Node: C API<10>,  Next: Build<10>,  Prev: Core and Builtins<28>,  Up: Python 3 14 0 alpha 6

1.24.13.13 C API
................

   - gh-111178(1): Fix *note PyCMethod: 969. API: replace ‘size_t nargs’
     with ‘Py_ssize_t nargs’ in *note PyCMethod: 969.  Patch by Victor
     Stinner.

   - gh-130947(2): Add again *note PySequence_Fast(): 188a. to the
     limited C API. Patch by Victor Stinner.

   - gh-128863(3): The following private functions are deprecated and
     planned for removal in Python 3.18:

        * ‘_PyUnicodeWriter_Init()’: replace
          ‘_PyUnicodeWriter_Init(&writer)’ with *note writer =
          PyUnicodeWriter_Create(0): 3b4.

        * ‘_PyUnicodeWriter_Finish()’: replace
          ‘_PyUnicodeWriter_Finish(&writer)’ with *note
          PyUnicodeWriter_Finish(writer): 3b7.

        * ‘_PyUnicodeWriter_Dealloc()’: replace
          ‘_PyUnicodeWriter_Dealloc(&writer)’ with *note
          PyUnicodeWriter_Discard(writer): 3b6.

        * ‘_PyUnicodeWriter_WriteChar()’: replace
          ‘_PyUnicodeWriter_WriteChar(&writer, ch)’ with *note
          PyUnicodeWriter_WriteChar(writer, ch): 3ba.

        * ‘_PyUnicodeWriter_WriteStr()’: replace
          ‘_PyUnicodeWriter_WriteStr(&writer, str)’ with *note
          PyUnicodeWriter_WriteStr(writer, str): 3bc.

        * ‘_PyUnicodeWriter_WriteSubstring()’: replace
          ‘_PyUnicodeWriter_WriteSubstring(&writer, str, start, end)’
          with *note PyUnicodeWriter_WriteSubstring(writer, str, start,
          end): 3bd.

        * ‘_PyUnicodeWriter_WriteASCIIString()’: replace
          ‘_PyUnicodeWriter_WriteASCIIString(&writer, str)’ with *note
          PyUnicodeWriter_WriteUTF8(writer, str): 3bf.

        * ‘_PyUnicodeWriter_WriteLatin1String()’: replace
          ‘_PyUnicodeWriter_WriteLatin1String(&writer, str)’ with *note
          PyUnicodeWriter_WriteUTF8(writer, str): 3bf.

        * ‘_PyUnicodeWriter_Prepare()’: (no replacement).

        * ‘_PyUnicodeWriter_PrepareKind()’: (no replacement).

     The pythoncapi-compat project(4) can be used to get these new
     public functions on Python 3.13 and older.

     Patch by Victor Stinner.

   - gh-45325(5): Add a new ‘p’ format parameter to *note
     Py_BuildValue(): 3c2. that allows to take a C integer and produce a
     Python *note bool: 3c3. object.  Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/111178

   (2) https://github.com/python/cpython/issues/130947

   (3) https://github.com/python/cpython/issues/128863

   (4) https://github.com/python/pythoncapi-compat/

   (5) https://github.com/python/cpython/issues/45325


File: python.info,  Node: Build<10>,  Prev: C API<10>,  Up: Python 3 14 0 alpha 6

1.24.13.14 Build
................

   - gh-131035(1): Use ‘-flto=thin’ for faster build times using
     clang-cl on Windows.  Patch by Chris Eibl.

   - gh-130740(2): Ensure that ‘Python.h’ is included before ‘stdbool.h’
     unless ‘pyconfig.h’ is included before or in some platform-specific
     contexts.

   - gh-130090(3): Building with ‘PlatformToolset=ClangCL’ on Windows
     now supports PGO (profile guided optimization).  Patch by Chris
     Eibl with invaluable support from Steve Dover.

   - gh-129819(4): Allow building the JIT with the tailcall interpreter.

   - gh-129989(5): Fix a bug where the tailcall interpreter was enabled
     when ‘--without-tail-call-interp’ was provided to the configure
     script.

   - gh-129838(6): Don’t redefine ‘_Py_NO_SANITIZE_UNDEFINED’ when
     compiling with a recent GCC version and undefined sanitizer
     enabled.

   - gh-82909(7): ‘#pragma’-based linking with ‘python3*.lib’ can now be
     switched off with *note Py_NO_LINK_LIB: 444.  Patch by
     Jean-Christophe Fillion-Robin.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/131035

   (2) https://github.com/python/cpython/issues/130740

   (3) https://github.com/python/cpython/issues/130090

   (4) https://github.com/python/cpython/issues/129819

   (5) https://github.com/python/cpython/issues/129989

   (6) https://github.com/python/cpython/issues/129838

   (7) https://github.com/python/cpython/issues/82909


File: python.info,  Node: Python 3 14 0 alpha 5,  Next: Python 3 14 0 alpha 4,  Prev: Python 3 14 0 alpha 6,  Up: Changelog

1.24.14 Python 3.14.0 alpha 5
-----------------------------

'Release date: 2025-02-11'

* Menu:

* macOS: macOS<5>.
* Tools/Demos: Tools/Demos<11>.
* Tests: Tests<9>.
* Security: Security<13>.
* Library: Library<32>.
* IDLE: IDLE<6>.
* Documentation: Documentation<10>.
* Core and Builtins: Core and Builtins<29>.
* Library: Library<33>.
* Core and Builtins: Core and Builtins<30>.
* Library: Library<34>.
* Core and Builtins: Core and Builtins<31>.
* Library: Library<35>.
* C API: C API<11>.
* Build: Build<11>.


File: python.info,  Node: macOS<5>,  Next: Tools/Demos<11>,  Up: Python 3 14 0 alpha 5

1.24.14.1 macOS
...............

   - gh-91132(1): Update macOS installer to use ncurses 6.5.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91132


File: python.info,  Node: Tools/Demos<11>,  Next: Tests<9>,  Prev: macOS<5>,  Up: Python 3 14 0 alpha 5

1.24.14.2 Tools/Demos
.....................

   - gh-129248(1): The iOS test runner now strips the log prefix from
     each line output by the test suite.

   - gh-104400(2): Fix several bugs in extraction by switching to an AST
     parser in ‘pygettext’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129248

   (2) https://github.com/python/cpython/issues/104400


File: python.info,  Node: Tests<9>,  Next: Security<13>,  Prev: Tools/Demos<11>,  Up: Python 3 14 0 alpha 5

1.24.14.3 Tests
...............

   - gh-129386(1): Add ‘test.support.reset_code’, which can be used to
     reset various bytecode-level optimizations and local
     instrumentation for a function.

   - gh-128474(2): Disable ‘test_embed’ test cases that segfault on BOLT
     instrument binaries.  The tests are only disabled when BOLT is
     enabled.

   - gh-128003(3): Add an option ‘--parallel-threads=N’ to the
     regression test runner that runs individual tests in multiple
     threads in parallel in order to find concurrency bugs.  Note that
     most of the test suite is not yet reviewed for thread-safety or
     annotated with ‘@thread_unsafe’ when necessary.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129386

   (2) https://github.com/python/cpython/issues/128474

   (3) https://github.com/python/cpython/issues/128003


File: python.info,  Node: Security<13>,  Next: Library<32>,  Prev: Tests<9>,  Up: Python 3 14 0 alpha 5

1.24.14.4 Security
..................

   - gh-105704(1): When using *note urllib.parse.urlsplit(): f3c. and
     *note urllib.parse.urlparse(): 362. host parsing would not reject
     domain names containing square brackets (‘[’ and ‘]’).  Square
     brackets are only valid for IPv6 and IPvFuture hosts according to
     RFC 3986 Section 3.2.2(2).

   - gh-126108(3): Fix a possible ‘NULL’ pointer dereference in
     ‘PySys_AddWarnOptionUnicode()’.

   - gh-80222(4): Fix bug in the folding of quoted strings when
     flattening an email message using a modern email policy.
     Previously when a quoted string was folded so that it spanned more
     than one line, the surrounding quotes and internal escapes would be
     omitted.  This could theoretically be used to spoof header lines
     using a carefully constructed quoted string if the resulting
     rendered email was transmitted or re-parsed.

   - gh-119511(5): Fix a potential denial of service in the *note
     imaplib: 78. module.  When connecting to a malicious server, it
     could cause an arbitrary amount of memory to be allocated.  On many
     systems this is harmless as unused virtual memory is only a
     mapping, but if this hit a virtual address size limit it could lead
     to a *note MemoryError: 1786. or other process crash.  On unusual
     systems or builds where all allocated memory is touched and backed
     by actual ram or storage it could’ve consumed resources doing so
     until similarly crashing.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/105704

   (2) https://www.rfc-editor.org/rfc/rfc3986#section-3.2.2

   (3) https://github.com/python/cpython/issues/126108

   (4) https://github.com/python/cpython/issues/80222

   (5) https://github.com/python/cpython/issues/119511


File: python.info,  Node: Library<32>,  Next: IDLE<6>,  Prev: Security<13>,  Up: Python 3 14 0 alpha 5

1.24.14.5 Library
.................

   - gh-129939(1): Comparison pages with highlighted changes generated
     by the *note difflib.HtmlDiff: 201. class now support dark mode.

   - gh-129928(2): Raise *note sqlite3.ProgrammingError: 305. if a
     user-defined SQL function with invalid number of parameters is
     created.  Patch by Erlend Aasland.

   - gh-129583(3): Update bundled pip to 25.0.1

   - gh-129766(4): Fix crash in *note warnings: 118, when calling
     ‘_release_lock()’ with no existing lock.

   - gh-129005(5): ‘_pyio.FileIO.readall()’ now allocates, resizes, and
     fills a data buffer using the same algorithm ‘_io.FileIO.readall()’
     uses.

   - gh-129646(6): Update the locale alias mapping in the *note locale:
     8a. module to match the latest X Org locale alias mapping and
     support new locales in Glibc 2.41.

   - gh-128317(7): Put CLI calendar highlighting in private class,
     removing ‘highlight_day’ from public *note calendar.TextCalendar:
     1892. API. Patch by Hugo van Kemenade.

   - gh-129603(8): Fix bugs where *note sqlite3.Row: 1073. objects could
     segfault if their inherited *note description: 1893. was set to
     ‘None’.  Patch by Erlend Aasland.

   - gh-129559(9): Add *note bytearray.resize(): 1894. method so *note
     bytearray: 344. can be efficiently resized in place.

   - gh-129502(10): Unlikely errors in preparing arguments for *note
     ctypes: 2e. callback are now handled in the same way as errors
     raised in the callback of in converting the result of the callback
     – using *note sys.unraisablehook(): 508. instead of *note
     sys.excepthook(): a0e. and not setting *note sys.last_exc: 6e6. and
     other variables.

   - gh-129403(11): Corrected *note ValueError: 2ec. message for *note
     asyncio.Barrier: 817. and *note threading.Barrier: 13eb.

   - gh-129409(12): Fix an integer overflow in the *note csv: 2d. module
     when writing a data field larger than 2GB.

   - gh-126400(13): Add a socket 'timeout' keyword argument to *note
     logging.handlers.SysLogHandler: 86d.

   - gh-118761(14): Always lazy import ‘warnings’ in *note threading:
     f3.  Patch by Taneli Hukkinen.

   - gh-118761(15): Improve import time of *note subprocess: dc. by lazy
     importing ‘locale’ and ‘signal’.  Patch by Taneli Hukkinen.

   - gh-129346(16): In *note sqlite3: d4, handle out-of-memory when
     creating user-defined SQL functions.

   - gh-129005(17): Optimize ‘_pyio.FileIO.readinto’ by avoiding
     unnecessary objects and copies using *note os.readinto(): 25f.

   - gh-129195(18): Support reporting call graph information from
     ‘asyncio.staggered.staggered_race()’.

   - gh-129205(19): Add *note os.readinto(): 25f. to read into a *note
     buffer object: 260. from a file descriptor.

   - gh-128772(20): Fix *note pydoc: ba. for methods with the
     ‘__module__’ attribute equal to ‘None’.

   - gh-129061(21): Fix FORCE_COLOR and NO_COLOR when empty strings.
     Patch by Hugo van Kemenade.

   - gh-92897(22): Scheduled the deprecation of the ‘check_home’
     argument of *note sysconfig.is_python_build(): 32d. to Python 3.15.

   - gh-129064(23): Deprecate ‘sysconfig.expand_makefile_vars()’, in
     favor of using *note sysconfig.get_paths(): 340. with the ‘vars’
     argument.

   - gh-128550(24): Removed an incorrect optimization relating to eager
     tasks in *note asyncio.TaskGroup: 4d2. that resulted in
     cancellations being missed.

   - gh-128991(25): Release the enter frame reference within *note bdb:
     10. callback

   - gh-118761(26): Reduce import time of *note pstats: b5. and *note
     zipfile: 137. by up to 20%, by removing unnecessary imports to
     *note typing: 10a.  Patch by Bénédikt Tran.

   - gh-128978(27): Fix a *note NameError: 452. in
     ‘sysconfig.expand_makefile_vars()’.  Patch by Bénédikt Tran.

   - gh-128961(28): Fix a crash when setting state on an exhausted *note
     array.array: 4bf. iterator.

   - gh-128894(29): Fix
     ‘traceback.TracebackException._format_syntax_error’ not to fail on
     exceptions with custom metadata.

   - gh-128916(30): Do not attempt to set ‘SO_REUSEPORT’ on sockets of
     address families other than ‘AF_INET’ and ‘AF_INET6’, as it is
     meaningless with these address families, and the call with fail
     with Linux kernel 6.12.9 and newer.

   - gh-118761(31): Improve import time of *note tomllib: 102. by
     removing ‘typing’, ‘string’, and ‘tomllib._types’ imports.  Patch
     by Taneli Hukkinen.

   - gh-128679(32): *note tracemalloc: 105.: Fix race conditions when
     *note tracemalloc.stop(): 1895. is called by a thread, while other
     threads are tracing memory allocations.  Patch by Victor Stinner.

   - gh-128891(33): Add specialized opcodes to ‘opcode.opname’.

   - gh-118761(34): Reduce import time of *note gettext: 67. by up to
     ten times, by importing *note re: be. on demand.  In particular,
     ‘re’ is no longer implicitly exposed as ‘gettext.re’.  Patch by Eli
     Schwartz.

   - gh-118761(35): Reduce the import time of *note optparse: a4. when
     no help text is printed.  Patch by Eli Schwartz.

   - gh-128657(36): Fix possible extra reference when using objects
     returned by *note hashlib.sha256(): 1896. under *note free
     threading: 1f4.

   - gh-118761(37): Reduce the import time of *note csv: 2d. by up to
     five times, by importing *note re: be. on demand.  In particular,
     ‘re’ is no more implicitly exposed as ‘csv.re’.  Patch by Bénédikt
     Tran.

   - gh-128308(38): Support the 'name' keyword argument for eager tasks
     in *note asyncio.loop.create_task(): 1ca, *note
     asyncio.create_task(): 1c9. and *note
     asyncio.TaskGroup.create_task(): 1cb, by passing on all 'kwargs' to
     the task factory set by *note asyncio.loop.set_task_factory(): 1c8.

   - gh-118761(39): Improve the performance of *note base64.b16decode():
     2d3. by up to ten times by more efficiently checking the
     byte-string for hexadecimal digits.  Reduce the import time of
     *note base64: f. by up to six times, by no longer importing *note
     re: be.  Patch by Bénédikt Tran, Chris Markiewicz, and Adam Turner.

   - gh-128156(40): When using macOS system ‘libffi’, support for
     complex types in *note ctypes: 2e. is now checked at runtime (macOS
     10.15 or newer).  The types must also be available at build time.

   - gh-128636(41): Fix PyREPL failure when *note os.environ: 259. is
     overwritten with an invalid value.

   - gh-128498(42): Default to stdout isatty for color detection instead
     of stderr.  Patch by Hugo van Kemenade.

   - gh-128384(43): Add locking to *note warnings: 118. to avoid some
     data races when free-threading is used.  Change
     ‘_warnings_runtime_state.mutex’ to be a recursive mutex and expose
     it to *note warnings: 118, via the ‘_acquire_lock()’ and
     ‘_release_lock()’ functions.  The lock is held when ‘filters’ and
     ‘_filters_version’ are updated.

   - gh-128509(44): Add *note sys._is_immortal(): 28f. for identifying
     *note immortal: 290. objects at runtime.

   - gh-128479(45): Fix ‘asyncio.staggered.staggered_race()’ leaking
     tasks and issuing an unhandled exception.

   - gh-128427(46): *note uuid.NIL: 2c5. and *note uuid.MAX: 2c6. are
     now available to represent the Nil and Max UUID formats as defined
     by RFC 9562(47).

   - gh-91279(48): *note zipfile.ZipFile.writestr(): 2cc. now respect
     ‘SOURCE_DATE_EPOCH’ that distributions can set centrally and have
     build tools consume this in order to produce reproducible output.

   - gh-112064(49): Fix incorrect handling of negative read sizes in
     *note HTTPResponse.read: 1897.  Patch by Yury Manushkin.

   - gh-58956(50): Fixed a frame reference leak in *note bdb: 10.

   - gh-128131(51): Completely support random access of uncompressed
     unencrypted read-only zip files obtained by *note ZipFile.open:
     65d.

   - gh-127975(52): Avoid reusing quote types in *note ast.unparse():
     ae4. if not needed.

   - gh-115514(53): Fix exceptions and incomplete writes after
     ‘asyncio._SelectorTransport’ is closed before writes are completed.

   - gh-121604(54): Add missing Deprecation warnings for *note
     importlib.machinery.DEBUG_BYTECODE_SUFFIXES: 1898, *note
     importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES: 1899, *note
     importlib.machinery.WindowsRegistryFinder: f28, *note
     importlib.abc.ResourceLoader: de4, *note
     importlib.abc.SourceLoader.path_mtime(): 1391.

   - gh-127873(55): When ‘-E’ is set, only ignore ‘PYTHON_COLORS’ and
     not ‘FORCE_COLOR’/‘NO_COLOR’/‘TERM’ when colourising output.  Patch
     by Hugo van Kemenade.

   - gh-125413(56): Add *note pathlib.Path.info: 26b. attribute, which
     stores an object implementing the *note pathlib.types.PathInfo:
     26c. protocol (also new).  The object supports querying the file
     type and internally caching *note stat(): 26d. results.  Path
     objects generated by *note iterdir(): 26e. are initialized with
     file type information gleaned from scanning the parent directory.

   - gh-127712(57): Fix handling of the ‘secure’ argument of *note
     logging.handlers.SMTPHandler: 189a.

   - gh-127096(58): Do not recreate unnamed section on every read in
     *note configparser.ConfigParser: 4df.  Patch by Andrey Efremov.

   - gh-124369(59): Deprecate ‘pdb.Pdb.curframe_locals’

   - gh-126332(60): Fix _pyrepl crash when entering a double CTRL-Z on
     an overflowing line.

   - gh-125553(61): Fix round-trip invariance for backslash
     continuations in *note tokenize.untokenize(): 189b.

   - gh-91048(62): Add *note asyncio.capture_call_graph(): 1cc. and
     *note asyncio.print_call_graph(): 1cd. functions.

   - gh-124703(63): Quitting *note pdb: aa. in ‘inline’ mode will emit a
     confirmation prompt and exit gracefully now, instead of printing an
     exception traceback.

   - gh-123987(64): Fixed issue in NamespaceReader where a non-path item
     in a namespace path, such as a sentinel added by an editable
     installer, would break resource loading.

   - gh-119349(65): Add the *note ctypes.util.dllist(): 1f0. function to
     list the loaded shared libraries for the current process.

   - gh-55454(66): Add IMAP4 ‘IDLE’ support to the *note imaplib: 78.
     module.  Patch by Forest.

   - gh-119257(67): Show tab completions menu below the current line,
     which results in less janky behaviour, and fixes a cursor movement
     bug.  Patch by Daniel Hollas

   - gh-101410(68): Support custom messages for domain errors in the
     *note math: 92. module (*note math.sqrt(): bfb, *note math.log():
     16c7. and *note math.atanh(): 15de. were modified as examples).
     Patch by Charlie Zhao and Sergey B Kirpichev.

   - gh-81340(69): Use *note os.copy_file_range(): 189c. in *note
     shutil.copy(): c51, *note shutil.copy2(): c52, and *note
     shutil.copyfile(): c50. functions by default.  An underlying Linux
     system call gives filesystems an opportunity to implement the use
     of copy-on-write (in case of btrfs and XFS) or server-side copy (in
     the case of NFS.) Patch by Illia Volochii.

   - bpo-27307(70): Add attribute and item access support to *note
     string.Formatter: 10bf. in auto-numbering mode, which allows format
     strings like “{.name}” and “{[1]}”.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129939

   (2) https://github.com/python/cpython/issues/129928

   (3) https://github.com/python/cpython/issues/129583

   (4) https://github.com/python/cpython/issues/129766

   (5) https://github.com/python/cpython/issues/129005

   (6) https://github.com/python/cpython/issues/129646

   (7) https://github.com/python/cpython/issues/128317

   (8) https://github.com/python/cpython/issues/129603

   (9) https://github.com/python/cpython/issues/129559

   (10) https://github.com/python/cpython/issues/129502

   (11) https://github.com/python/cpython/issues/129403

   (12) https://github.com/python/cpython/issues/129409

   (13) https://github.com/python/cpython/issues/126400

   (14) https://github.com/python/cpython/issues/118761

   (15) https://github.com/python/cpython/issues/118761

   (16) https://github.com/python/cpython/issues/129346

   (17) https://github.com/python/cpython/issues/129005

   (18) https://github.com/python/cpython/issues/129195

   (19) https://github.com/python/cpython/issues/129205

   (20) https://github.com/python/cpython/issues/128772

   (21) https://github.com/python/cpython/issues/129061

   (22) https://github.com/python/cpython/issues/92897

   (23) https://github.com/python/cpython/issues/129064

   (24) https://github.com/python/cpython/issues/128550

   (25) https://github.com/python/cpython/issues/128991

   (26) https://github.com/python/cpython/issues/118761

   (27) https://github.com/python/cpython/issues/128978

   (28) https://github.com/python/cpython/issues/128961

   (29) https://github.com/python/cpython/issues/128894

   (30) https://github.com/python/cpython/issues/128916

   (31) https://github.com/python/cpython/issues/118761

   (32) https://github.com/python/cpython/issues/128679

   (33) https://github.com/python/cpython/issues/128891

   (34) https://github.com/python/cpython/issues/118761

   (35) https://github.com/python/cpython/issues/118761

   (36) https://github.com/python/cpython/issues/128657

   (37) https://github.com/python/cpython/issues/118761

   (38) https://github.com/python/cpython/issues/128308

   (39) https://github.com/python/cpython/issues/118761

   (40) https://github.com/python/cpython/issues/128156

   (41) https://github.com/python/cpython/issues/128636

   (42) https://github.com/python/cpython/issues/128498

   (43) https://github.com/python/cpython/issues/128384

   (44) https://github.com/python/cpython/issues/128509

   (45) https://github.com/python/cpython/issues/128479

   (46) https://github.com/python/cpython/issues/128427

   (47) https://datatracker.ietf.org/doc/html/rfc9562.html

   (48) https://github.com/python/cpython/issues/91279

   (49) https://github.com/python/cpython/issues/112064

   (50) https://github.com/python/cpython/issues/58956

   (51) https://github.com/python/cpython/issues/128131

   (52) https://github.com/python/cpython/issues/127975

   (53) https://github.com/python/cpython/issues/115514

   (54) https://github.com/python/cpython/issues/121604

   (55) https://github.com/python/cpython/issues/127873

   (56) https://github.com/python/cpython/issues/125413

   (57) https://github.com/python/cpython/issues/127712

   (58) https://github.com/python/cpython/issues/127096

   (59) https://github.com/python/cpython/issues/124369

   (60) https://github.com/python/cpython/issues/126332

   (61) https://github.com/python/cpython/issues/125553

   (62) https://github.com/python/cpython/issues/91048

   (63) https://github.com/python/cpython/issues/124703

   (64) https://github.com/python/cpython/issues/123987

   (65) https://github.com/python/cpython/issues/119349

   (66) https://github.com/python/cpython/issues/55454

   (67) https://github.com/python/cpython/issues/119257

   (68) https://github.com/python/cpython/issues/101410

   (69) https://github.com/python/cpython/issues/81340

   (70) https://bugs.python.org/issue?@action=redirect&bpo=27307


File: python.info,  Node: IDLE<6>,  Next: Documentation<10>,  Prev: Library<32>,  Up: Python 3 14 0 alpha 5

1.24.14.6 IDLE
..............

   - gh-129873(1): Simplify displaying the IDLE doc by only copying the
     text section of idle.html to idlelib/help.html.  Patch by Stan
     Ulbrych.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129873


File: python.info,  Node: Documentation<10>,  Next: Core and Builtins<29>,  Prev: IDLE<6>,  Up: Python 3 14 0 alpha 5

1.24.14.7 Documentation
.......................

   - gh-125722(1): Require Sphinx 8.1.3 or later to build the Python
     documentation.  Patch by Adam Turner.

   - gh-67206(2): Document that *note string.printable: 189f. is not
     printable in the POSIX sense.  In particular, *note
     string.printable.isprintable(): fda. returns *note False: d2d.
     Patch by Bénédikt Tran.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/125722

   (2) https://github.com/python/cpython/issues/67206


File: python.info,  Node: Core and Builtins<29>,  Next: Library<33>,  Prev: Documentation<10>,  Up: Python 3 14 0 alpha 5

1.24.14.8 Core and Builtins
...........................

   - gh-100239(1): Replace the opcode BINARY_SUBSCR and its family by
     BINARY_OP with oparg NB_SUBSCR.

   - gh-129732(2): Fixed a race in ‘_Py_qsbr_reserve’ in the free
     threading build.

   - gh-129763(3): Remove the internal ‘LLTRACE’ macro (use *note
     Py_DEBUG: 181c. instead).

   - gh-129715(4): Improve JIT performance for generators.

   - gh-129643(5): Fix thread safety of *note PyList_Insert(): 18a1. in
     free-threading builds.

   - gh-129668(6): Fix race condition when raising *note MemoryError:
     1786. in the free threaded build.

   - gh-129643(7): Fix thread safety of *note PyList_SetItem(): 18a2. in
     free-threading builds.  Patch by Kumar Aditya.

   - gh-128563(8): Fix an issue where the «lltrace» debug feature could
     have been incorrectly enabled for some frames.

   - gh-129393(9): On FreeBSD, *note sys.platform: 291. doesn’t contain
     the major version anymore.  It is always ‘'freebsd'’, instead of
     ‘'freebsd13'’ or ‘'freebsd14'’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100239

   (2) https://github.com/python/cpython/issues/129732

   (3) https://github.com/python/cpython/issues/129763

   (4) https://github.com/python/cpython/issues/129715

   (5) https://github.com/python/cpython/issues/129643

   (6) https://github.com/python/cpython/issues/129668

   (7) https://github.com/python/cpython/issues/129643

   (8) https://github.com/python/cpython/issues/128563

   (9) https://github.com/python/cpython/issues/129393


File: python.info,  Node: Library<33>,  Next: Core and Builtins<30>,  Prev: Core and Builtins<29>,  Up: Python 3 14 0 alpha 5

1.24.14.9 Library
.................

   - gh-129345(1): Fix null pointer dereference in *note
     syslog.openlog(): 761. when an audit hook raises an exception.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129345


File: python.info,  Node: Core and Builtins<30>,  Next: Library<34>,  Prev: Library<33>,  Up: Python 3 14 0 alpha 5

1.24.14.10 Core and Builtins
............................

   - gh-129231(1): Improve memory layout of JIT traces.  Patch by Diego
     Russo

   - gh-129149(2): Add fast path for medium-size integers in *note
     PyLong_FromUnsignedLong(): 18a5, *note
     PyLong_FromUnsignedLongLong(): 18a6. and *note PyLong_FromSize_t():
     18a7.

   - gh-129201(3): The free-threaded version of the cyclic garbage
     collector has been optimized to conditionally use CPU prefetch
     instructions during the collection.  This can reduce collection
     times by making it more likely that data is in the CPU cache when
     it is needed.  The prefetch instructions are enabled if the number
     of long-lived objects (objects surviving a full collection) exceeds
     a threshold.

   - gh-129093(4): Fix f-strings such as ‘f'{expr=}'’ sometimes not
     displaying the full expression when the expression contains ‘!=’.

   - gh-124363(5): Treat debug expressions in f-string as raw strings.
     Patch by Pablo Galindo

   - gh-128714(6): Fix the potential races in get/set dunder methods
     ‘__annotations__’, ‘__annotate__’ and ‘__type_params__’ for
     function object, and add related tests.

   - gh-128799(7): Add frame of ‘except*’ to traceback when it wraps a
     naked exception.

   - gh-128842(8): Collect JIT memory stats using pystats.  Patch by
     Diego Russo.

   - gh-100239(9): Specialize ‘BINARY_OP’ for bitwise logical operations
     on compact ints.

   - gh-128910(10): Undocumented and unused private C-API functions
     ‘_PyTrash_begin’ and ‘_PyTrash_end’ are removed.

   - gh-128807(11): Add a marking phase to the free-threaded GC. This is
     similar to what was done in gh-126491(12).  Since the free-threaded
     GC does not have generations and is not incremental, the marking
     phase looks for all objects reachable from known roots.  The roots
     are objects known to not be garbage, like the module dictionary for
     *note sys: df.  For most programs, this marking phase should make
     the GC a bit faster since typically less work is done per object.

   - gh-100239(13): Add opcode ‘BINARY_OP_EXTEND’ which executes a pair
     of functions (guard and specialization functions) accessed from the
     inline cache.

   - gh-128563(14): A new type of interpreter has been added to CPython.
     This interpreter uses tail calls for its instruction handlers.
     Preliminary benchmark results suggest 7-11% geometric mean faster
     on pyperformance (depending on platform), and up to 30% faster on
     Python-intensive workloads.  This interpreter currently only works
     on newer compilers, such as ‘clang-19’.  Other compilers will
     continue using the old interpreter.  Patch by Ken Jin, with ideas
     on how to implement this in CPython by Mark Shannon, Garret Gu,
     Haoran Xu, and Josh Haberman.

   - gh-126703(15): Improve performance of iterating over lists and
     tuples by using a freelist for the iterator objects.

   - gh-127953(16): The time to handle a ‘LINE’ event in sys.monitoring
     (and sys.settrace) is now independent of the number of lines in the
     code object.

   - gh-128330(17): Restore terminal control characters on REPL exit.

   - gh-128016(18): Improved the ‘SyntaxWarning’ message for invalid
     escape sequences to clarify that such sequences will raise a
     ‘SyntaxError’ in future Python releases.  The new message also
     suggests a potential fix, i.e., ‘Did you mean "\\e"?’.

   - gh-126004(19): Fix handling of *note UnicodeError.start: 18a8. and
     *note UnicodeError.end: 18a9. values in the *note
     codecs.replace_errors(): 18aa. error handler.  Patch by Bénédikt
     Tran.

   - gh-126004(20): Fix handling of *note UnicodeError.start: 18a8. and
     *note UnicodeError.end: 18a9. values in the *note
     codecs.backslashreplace_errors(): 18ab. error handler.  Patch by
     Bénédikt Tran.

   - gh-126004(21): Fix handling of *note UnicodeError.start: 18a8. and
     *note UnicodeError.end: 18a9. values in the *note
     codecs.xmlcharrefreplace_errors(): 18ac. error handler.  Patch by
     Bénédikt Tran.

   - gh-127119(22): Slightly optimize the *note int: 19b. deallocator.

   - gh-127349(23): Fixed the error when resizing terminal in Python
     REPL. Patch by Semyon Moroz.

   - gh-125723(24): Fix crash with ‘gi_frame.f_locals’ when generator
     frames outlive their generator.  Patch by Mikhail Efimov.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129231

   (2) https://github.com/python/cpython/issues/129149

   (3) https://github.com/python/cpython/issues/129201

   (4) https://github.com/python/cpython/issues/129093

   (5) https://github.com/python/cpython/issues/124363

   (6) https://github.com/python/cpython/issues/128714

   (7) https://github.com/python/cpython/issues/128799

   (8) https://github.com/python/cpython/issues/128842

   (9) https://github.com/python/cpython/issues/100239

   (10) https://github.com/python/cpython/issues/128910

   (11) https://github.com/python/cpython/issues/128807

   (12) https://github.com/python/cpython/issues/126491

   (13) https://github.com/python/cpython/issues/100239

   (14) https://github.com/python/cpython/issues/128563

   (15) https://github.com/python/cpython/issues/126703

   (16) https://github.com/python/cpython/issues/127953

   (17) https://github.com/python/cpython/issues/128330

   (18) https://github.com/python/cpython/issues/128016

   (19) https://github.com/python/cpython/issues/126004

   (20) https://github.com/python/cpython/issues/126004

   (21) https://github.com/python/cpython/issues/126004

   (22) https://github.com/python/cpython/issues/127119

   (23) https://github.com/python/cpython/issues/127349

   (24) https://github.com/python/cpython/issues/125723


File: python.info,  Node: Library<34>,  Next: Core and Builtins<31>,  Prev: Core and Builtins<30>,  Up: Python 3 14 0 alpha 5

1.24.14.11 Library
..................

   - gh-126349(1): Add *note turtle.fill(): 2a3, *note turtle.poly():
     2a4. and *note turtle.no_animation(): 2a5. context managers.  Patch
     by Marie Roald and Yngve Mardal Moe.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126349


File: python.info,  Node: Core and Builtins<31>,  Next: Library<35>,  Prev: Library<34>,  Up: Python 3 14 0 alpha 5

1.24.14.12 Core and Builtins
............................

   - gh-115911(1): If the current working directory cannot be determined
     due to permissions, then import will no longer raise *note
     PermissionError: f40.  Patch by Alex Willmer.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115911


File: python.info,  Node: Library<35>,  Next: C API<11>,  Prev: Core and Builtins<31>,  Up: Python 3 14 0 alpha 5

1.24.14.13 Library
..................

   - gh-112713(1): Added support for the ‘Partitioned’ cookie flag in
     *note http.cookies: 75.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/112713


File: python.info,  Node: C API<11>,  Next: Build<11>,  Prev: Library<35>,  Up: Python 3 14 0 alpha 5

1.24.14.14 C API
................

   - gh-129533(1): Update *note PyGC_Enable(): aa6, *note
     PyGC_Disable(): aa7, *note PyGC_IsEnabled(): aa8. to use atomic
     operation for thread-safety at free-threading build.  Patch by
     Donghee Na.

   - gh-89188(2): Implement *note PyUnicode_KIND(): 1385. and *note
     PyUnicode_DATA(): 1381. as function, in addition to the macros with
     the same names.  The macros rely on C bit fields which have
     compiler-specific layout.  Patch by Victor Stinner.

   - gh-91417(3): Remove *note PySequence_Fast(): 188a. from the limited
     C API, since this function has to be used with *note
     PySequence_Fast_GET_ITEM: 3cb. which never worked in the limited C
     API. Patch by Victor Stinner.

   - gh-128509(4): Add *note PyUnstable_IsImmortal(): 3c4. for
     determining whether an object is *note immortal: 290.

   - gh-129033(5): Remove ‘_PyInterpreterState_GetConfigCopy()’ and
     ‘_PyInterpreterState_SetConfig()’ private functions.  Use instead
     *note PyConfig_Get(): 37c. and *note PyConfig_Set(): 37d, public C
     API added by PEP 741(6) «Python Configuration C API».  Patch by
     Victor Stinner.

   - gh-129033(7): Remove the private ‘_Py_InitializeMain()’ function.
     It was a *note provisional API: 3d1. added to Python 3.8 by PEP
     587(8).  Patch by Victor Stinner.

   - gh-128844(9): Add *note PyUnstable_TryIncRef(): 18b1. and *note
     PyUnstable_EnableTryIncRef(): 18b2. unstable APIs.  These are
     helpers for dealing with unowned references in a thread-safe way,
     particularly in the free threading build.

   - gh-128911(10): Add *note PyImport_ImportModuleAttr(): 396. and
     *note PyImport_ImportModuleAttrString(): 397. helper functions to
     import a module and get an attribute of the module.  Patch by
     Victor Stinner.

   - gh-128863(11): The following private functions are deprecated and
     planned for removal in Python 3.18:

        * ‘_PyBytes_Join()’: use *note PyBytes_Join(): 383.

        * ‘_PyDict_GetItemStringWithError()’: use *note
          PyDict_GetItemStringRef(): 421.

        * ‘_PyDict_Pop()’: use *note PyDict_Pop(): 422.

        * ‘_PyLong_Sign()’: use *note PyLong_GetSign(): 39a.

        * ‘_PyLong_FromDigits()’ and ‘_PyLong_New()’: use *note
          PyLongWriter_Create(): 3aa.

        * ‘_PyThreadState_UncheckedGet()’: use *note
          PyThreadState_GetUnchecked(): 423.

        * ‘_PyUnicode_AsString()’: use *note PyUnicode_AsUTF8(): 424.

        * ‘_Py_HashPointer()’: use *note Py_HashPointer(): 425.

        * ‘_Py_fopen_obj()’: use *note Py_fopen(): 393.

     The pythoncapi-compat project(12) can be used to get these new
     public functions on Python 3.13 and older.

     Patch by Victor Stinner.

   - gh-126599(13): Remove some internal test APIs for the experimental
     JIT compiler.

   - gh-127925(14): Convert the *note decimal: 3a. module to use PEP
     757(15) C API (export-import integers), offering some speed-up if
     the integer part of the *note Decimal: 1fe. instance is small.
     Patch by Sergey B Kirpichev.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129533

   (2) https://github.com/python/cpython/issues/89188

   (3) https://github.com/python/cpython/issues/91417

   (4) https://github.com/python/cpython/issues/128509

   (5) https://github.com/python/cpython/issues/129033

   (6) https://peps.python.org/pep-0741/

   (7) https://github.com/python/cpython/issues/129033

   (8) https://peps.python.org/pep-0587/

   (9) https://github.com/python/cpython/issues/128844

   (10) https://github.com/python/cpython/issues/128911

   (11) https://github.com/python/cpython/issues/128863

   (12) https://github.com/python/pythoncapi-compat/

   (13) https://github.com/python/cpython/issues/126599

   (14) https://github.com/python/cpython/issues/127925

   (15) https://peps.python.org/pep-0757/


File: python.info,  Node: Build<11>,  Prev: C API<11>,  Up: Python 3 14 0 alpha 5

1.24.14.15 Build
................

   - gh-129660(1): Drop ‘test_embed’ from PGO training, whose
     contribution in recent versions is considered to be ignorable.

   - gh-128902(2): Fix compile errors with Clang 9 and older due to lack
     of ‘__attribute__((fallthrough))’ support.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/129660

   (2) https://github.com/python/cpython/issues/128902


File: python.info,  Node: Python 3 14 0 alpha 4,  Next: Python 3 14 0 alpha 3,  Prev: Python 3 14 0 alpha 5,  Up: Changelog

1.24.15 Python 3.14.0 alpha 4
-----------------------------

'Release date: 2025-01-14'

* Menu:

* macOS: macOS<6>.
* Tools/Demos: Tools/Demos<12>.
* Tests: Tests<10>.
* Library: Library<36>.
* Core and Builtins: Core and Builtins<32>.
* Library: Library<37>.
* Core and Builtins: Core and Builtins<33>.
* Library: Library<38>.
* Core and Builtins: Core and Builtins<34>.
* C API: C API<12>.
* Build: Build<12>.


File: python.info,  Node: macOS<6>,  Next: Tools/Demos<12>,  Up: Python 3 14 0 alpha 4

1.24.15.1 macOS
...............

   - gh-127592(1): Usage of the unified Apple System Log APIs was
     disabled when the minimum macOS version is earlier than 10.12.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127592


File: python.info,  Node: Tools/Demos<12>,  Next: Tests<10>,  Prev: macOS<6>,  Up: Python 3 14 0 alpha 4

1.24.15.2 Tools/Demos
.....................

   - gh-128152(1): Fix a bug where Argument Clinic’s C pre-processor
     parser tried to parse pre-processor directives inside C comments.
     Patch by Erlend Aasland.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128152


File: python.info,  Node: Tests<10>,  Next: Library<36>,  Prev: Tools/Demos<12>,  Up: Python 3 14 0 alpha 4

1.24.15.3 Tests
...............

   - gh-128690(1): Temporarily do not use test_embed in PGO profile
     builds until the problem with test_init_pyvenv_cfg failing in some
     configurations is resolved.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128690


File: python.info,  Node: Library<36>,  Next: Core and Builtins<32>,  Prev: Tests<10>,  Up: Python 3 14 0 alpha 4

1.24.15.4 Library
.................

   - gh-128731(1): Fix *note ResourceWarning: 54d. in *note
     urllib.robotparser.RobotFileParser.read(): 18b9.

   - gh-71339(2): Add new assertion methods for *note unittest: 10c.:
     *note assertHasAttr(): 2b4, *note assertNotHasAttr(): 2b5, *note
     assertIsSubclass(): 2b6, *note assertNotIsSubclass(): 2b7. *note
     assertStartsWith(): 2b8, *note assertNotStartsWith(): 2b9, *note
     assertEndsWith(): 2ba. and *note assertNotEndsWith(): 2bb.

   - gh-118761(3): Improve import time of *note pickle: ab. by 25% by
     removing an unnecessary regular expression.  As such, *note re: be.
     is no more implicitly available as ‘pickle.re’.  Patch by Bénédikt
     Tran.

   - gh-128661(4): Fixes *note typing.evaluate_forward_ref(): 17fd. not
     showing deprecation when ‘type_params’ arg is not passed.

   - gh-128562(5): Fix possible conflicts in generated *note tkinter:
     f6. widget names if the widget class name ends with a digit.

   - gh-128559(6): Improved import time of *note asyncio: b.

   - gh-128552(7): Fix cyclic garbage introduced by *note
     asyncio.loop.create_task(): 1ca. and *note
     asyncio.TaskGroup.create_task(): 1cb. holding a reference to the
     created task if it is eager.

   - gh-128340(8): Add internal thread safe handle to be used in *note
     asyncio.loop.call_soon_threadsafe(): cfd. for thread safe
     cancellation.

   - gh-128182(9): Fix crash when using *note ctypes: 2e. pointers
     concurrently on the *note free threaded: 1f4. build.

   - gh-128400(10): Only show the current thread in *note faulthandler:
     5c. on the *note free threaded: 1f4. build to prevent races.

   - gh-128400(11): Fix crash when using *note
     faulthandler.dump_traceback(): 1001. while other threads are active
     on the *note free threaded: 1f4. build.

   - gh-128388(12): Fix ‘PyREPL’ on Windows to support more keybindings,
     like the ‘Control’-‘←’ and ‘Control’-‘→’ word-skipping keybindings
     and those with meta (i.e.  ‘Alt’), e.g.  ‘Alt’-‘d’ to ‘kill-word’
     or ‘Alt’-‘Backspace’ ‘backward-kill-word’.

   - gh-88834(13): Unify the instance check for *note typing.Union: 2a8.
     and *note types.UnionType: 2a7.: ‘Union’ now uses the instance
     checks against its parameters instead of the subclass checks.

   - gh-128302(14): Fix
     ‘xml.dom.xmlbuilder.DOMEntityResolver.resolveEntity()’, which was
     broken by the Python 3.0 transition.

   - gh-128317(15): Highlight today in colour in *note calendar: 15.’s
     CLI output.  Patch by Hugo van Kemenade.

   - gh-128302(16): Allow ‘xml.dom.xmlbuilder.DOMParser.parse()’ to
     correctly handle ‘xml.dom.xmlbuilder.DOMInputSource’ instances that
     only have a ‘systemId’ attribute set.

   - gh-128151(17): Improve generation of *note UUID: c58. objects
     version 3, 4, 5, and 8 via their dedicated functions by 30%.  Patch
     by Bénédikt Tran.

   - gh-128118(18): Improve performance of *note copy.copy(): 758. by
     30% via a fast path for atomic types and container types.

   - gh-127946(19): Fix crash when modifying *note ctypes._CFuncPtr:
     18ba. objects concurrently on the *note free threaded: 1f4. build.

   - gh-128062(20): Revert the font of *note turtledemo: 108.’s menu bar
     to its default value and display the shortcut keys in the correct
     position.

   - gh-128014(21): Fix resetting the default window icon by passing
     ‘default=''’ to the *note tkinter: f6. method ‘wm_iconbitmap()’.

   - gh-41872(22): Fix quick extraction of module docstrings from a file
     in *note pydoc: ba.  It now supports docstrings with single quotes,
     escape sequences, raw string literals, and other Python syntax.

   - gh-127060(23): Set TERM environment variable to «dumb» to disable
     traceback colors in IDLE, since IDLE doesn’t understand ANSI escape
     sequences.  Patch by Victor Stinner.

   - gh-126742(24): Fix support of localized error messages reported by
     ‘dlerror(3)(25)’ and ‘gdbm_strerror(26)’ in *note ctypes: 2e. and
     *note dbm.gnu: 37. functions respectively.  Patch by Bénédikt Tran.

   - gh-122548(27): Adds two new local events to sys.monitoring,
     ‘BRANCH_LEFT’ and ‘BRANCH_RIGHT’.  This allows the two arms of the
     branch to be disabled independently, which should hugely improve
     performance of branch-level coverage tools.  The old branch event,
     ‘BRANCH’ is now deprecated.

   - gh-127847(28): Fix the position when doing interleaved seeks and
     reads in uncompressed, unencrypted zip files returned by *note
     zipfile.ZipFile.open(): 65d.

   - gh-127688(29): Add the *note SCHED_DEADLINE: 25d. and *note
     SCHED_NORMAL: 25e. constants to the *note os: a5. module.

   - gh-83662(30): Add missing ‘__class_getitem__’ method to the Python
     implementation of *note functools.partial(): 217, to make it
     compatible with the C version.  This is mainly relevant for
     alternative Python implementations like PyPy and GraalPy, because
     CPython will usually use the C-implementation of that function.

   - gh-127586(31): *note multiprocessing.pool.Pool: 116d. now properly
     restores blocked signal handlers of the parent thread when creating
     processes via either 'spawn' or 'forkserver'.

   - gh-98188(32): Fix an issue in *note
     email.message.Message.get_payload(): 13d5. where data cannot be
     decoded if the Content Transfer Encoding mechanism contains
     trailing whitespaces or additional junk text.  Patch by Hui Liu.

   - gh-127529(33): Correct behavior of
     ‘asyncio.selector_events.BaseSelectorEventLoop._accept_connection()’
     in handling *note ConnectionAbortedError: 125f. in a loop.  This
     improves performance on OpenBSD.

   - gh-127360(34): When a descriptive error message cannot be provided
     for an *note ssl.SSLError: 1481, the «unknown error» message now
     shows the internal error code (as retrieved by ‘ERR_get_error’ and
     similar OpenSSL functions).

   - gh-127196(35): Fix crash when dict with keys in invalid encoding
     were passed to several functions in ‘_interpreters’ module.

   - gh-124130(36): Fix a bug in matching regular expression ‘\B’ in
     empty input string.  Now it is always the opposite of ‘\b’.  To get
     an old behavior, use ‘(?!\A\Z)\B’.  To get a new behavior in old
     Python versions, use ‘(?!\b)’.

   - gh-126639(37): *note tempfile.NamedTemporaryFile: 6ee. will now
     issue a *note ResourceWarning: 54d. when it is finalized by the
     garbage collector without being explicitly closed.

   - gh-126624(38): Expose error code *note XML_ERROR_NOT_STARTED: 18bb.
     of Expat >=2.6.4 in *note xml.parsers.expat.errors: 12d.

   - gh-126225(39): *note getopt: 65. and *note optparse: a4. are no
     longer marked as deprecated.  There are legitimate reasons to use
     one of these modules in preference to *note argparse: 7, and none
     of these modules are at risk of being removed from the standard
     library.  Of the three, ‘argparse’ remains the recommended default
     choice, 'unless' one of the concerns noted at the top of the
     ‘optparse’ module documentation applies.

   - gh-124761(40): Add *note SO_REUSEPORT_LB: 18bc. constant to *note
     socket: d1. for FreeBSD.

   - gh-121720(41): *note enum.EnumDict: 4f7. can now be used without
     resorting to private API.

   - gh-123424(42): Add *note zipfile.ZipInfo._for_archive(): 2ca.
     setting default properties on *note ZipInfo: 2cb. objects.  Patch
     by Bénédikt Tran and Jason R. Coombs.

   - gh-121676(43): Deprecate calling the Python implementation of *note
     functools.reduce(): 21a. with a ‘function’ or ‘sequence’ as a *note
     keyword argument: f10.  This will be forbidden in Python 3.16 in
     order to match the C implementation.

   - gh-112015(44): *note ctypes.memoryview_at(): 1eb. now exists to
     create a *note memoryview: 165. object that refers to the supplied
     pointer and length.  This works like *note ctypes.string_at(): 1ec.
     except it avoids a buffer copy, and is typically useful when
     implementing pure Python callback functions that are passed
     dynamically-sized buffers.

   - gh-95371(45): Added support for other image formats (PNG, PGM, and
     PPM) to the turtle module.  Patch by Shin-myoung-serp.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128731

   (2) https://github.com/python/cpython/issues/71339

   (3) https://github.com/python/cpython/issues/118761

   (4) https://github.com/python/cpython/issues/128661

   (5) https://github.com/python/cpython/issues/128562

   (6) https://github.com/python/cpython/issues/128559

   (7) https://github.com/python/cpython/issues/128552

   (8) https://github.com/python/cpython/issues/128340

   (9) https://github.com/python/cpython/issues/128182

   (10) https://github.com/python/cpython/issues/128400

   (11) https://github.com/python/cpython/issues/128400

   (12) https://github.com/python/cpython/issues/128388

   (13) https://github.com/python/cpython/issues/88834

   (14) https://github.com/python/cpython/issues/128302

   (15) https://github.com/python/cpython/issues/128317

   (16) https://github.com/python/cpython/issues/128302

   (17) https://github.com/python/cpython/issues/128151

   (18) https://github.com/python/cpython/issues/128118

   (19) https://github.com/python/cpython/issues/127946

   (20) https://github.com/python/cpython/issues/128062

   (21) https://github.com/python/cpython/issues/128014

   (22) https://github.com/python/cpython/issues/41872

   (23) https://github.com/python/cpython/issues/127060

   (24) https://github.com/python/cpython/issues/126742

   (25) https://manpages.debian.org/dlerror(3)

   (26) https://manpages.debian.org/gdbm(3)

   (27) https://github.com/python/cpython/issues/122548

   (28) https://github.com/python/cpython/issues/127847

   (29) https://github.com/python/cpython/issues/127688

   (30) https://github.com/python/cpython/issues/83662

   (31) https://github.com/python/cpython/issues/127586

   (32) https://github.com/python/cpython/issues/98188

   (33) https://github.com/python/cpython/issues/127529

   (34) https://github.com/python/cpython/issues/127360

   (35) https://github.com/python/cpython/issues/127196

   (36) https://github.com/python/cpython/issues/124130

   (37) https://github.com/python/cpython/issues/126639

   (38) https://github.com/python/cpython/issues/126624

   (39) https://github.com/python/cpython/issues/126225

   (40) https://github.com/python/cpython/issues/124761

   (41) https://github.com/python/cpython/issues/121720

   (42) https://github.com/python/cpython/issues/123424

   (43) https://github.com/python/cpython/issues/121676

   (44) https://github.com/python/cpython/issues/112015

   (45) https://github.com/python/cpython/issues/95371


File: python.info,  Node: Core and Builtins<32>,  Next: Library<37>,  Prev: Library<36>,  Up: Python 3 14 0 alpha 4

1.24.15.5 Core and Builtins
...........................

   - gh-128078(1): Fix a *note SystemError: 796. when using *note
     anext(): 9d8. with a default tuple value.  Patch by Bénédikt Tran.

   - gh-128717(2): Fix a crash when setting the recursion limit while
     other threads are active on the *note free threaded: 1f4. build.

   - gh-124483(3): Treat ‘Py_DECREF’ and variants as escaping when
     generating opcode and uop metadata.  This prevents the possibility
     of a ‘__del__’ method causing the JIT to behave incorrectly.

   - gh-126703(4): Improve performance of class methods by using a
     freelist.

   - gh-128137(5): Update *note PyASCIIObject: 137d. layout to handle
     interned field with the atomic operation.  Patch by Donghee Na.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128078

   (2) https://github.com/python/cpython/issues/128717

   (3) https://github.com/python/cpython/issues/124483

   (4) https://github.com/python/cpython/issues/126703

   (5) https://github.com/python/cpython/issues/128137


File: python.info,  Node: Library<37>,  Next: Core and Builtins<33>,  Prev: Core and Builtins<32>,  Up: Python 3 14 0 alpha 4

1.24.15.6 Library
.................

   - gh-128192(1): Upgrade HTTP digest authentication algorithm for
     *note urllib.request: 111. by supporting SHA-256 digest
     authentication as specified in RFC 7616(2).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128192

   (2) https://datatracker.ietf.org/doc/html/rfc7616.html


File: python.info,  Node: Core and Builtins<33>,  Next: Library<38>,  Prev: Library<37>,  Up: Python 3 14 0 alpha 4

1.24.15.7 Core and Builtins
...........................

   - gh-126868(1): Increase usage of freelist for *note int: 19b.
     allocation.

   - gh-114203(2): Optimize ‘Py_BEGIN_CRITICAL_SECTION’ for simple
     recursive calls.

   - gh-127705(3): Adds stackref debugging when ‘Py_STACKREF_DEBUG’ is
     set.  Finds all double-closes and leaks, logging the origin and
     last borrow.

     Inspired by HPy’s debug mode.
     ‘https://docs.hpyproject.org/en/latest/debug-mode.html’

   - gh-128079(4): Fix a bug where *note except*: 1ac. does not properly
     check the return value of an *note ExceptionGroup: 4d3.’s *note
     split(): 18c0. function, leading to a crash in some cases.  Now
     when *note split(): 18c0. returns an invalid object, *note except*:
     1ac. raises a *note TypeError: 198. with the original raised *note
     ExceptionGroup: 4d3. object chained to it.

   - gh-128030(5): Avoid error from calling ‘PyModule_GetFilenameObject’
     on a non-module object when importing a non-existent symbol from a
     non-module object.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126868

   (2) https://github.com/python/cpython/issues/114203

   (3) https://github.com/python/cpython/issues/127705

   (4) https://github.com/python/cpython/issues/128079

   (5) https://github.com/python/cpython/issues/128030


File: python.info,  Node: Library<38>,  Next: Core and Builtins<34>,  Prev: Core and Builtins<33>,  Up: Python 3 14 0 alpha 4

1.24.15.8 Library
.................

   - gh-128035(1): Indicate through *note ssl.HAS_PHA: 286. whether the
     *note ssl: d5. module supports TLSv1.3 post-handshake client
     authentication (PHA). Patch by Will Childs-Klein.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128035


File: python.info,  Node: Core and Builtins<34>,  Next: C API<12>,  Prev: Library<38>,  Up: Python 3 14 0 alpha 4

1.24.15.9 Core and Builtins
...........................

   - gh-127274(1): Add a new flag, ‘CO_METHOD’, to *note co_flags: 18c3.
     that indicates whether the code object belongs to a function
     defined in class scope.

   - gh-66409(2): During the *note path initialization: 18c4, we now
     check if ‘base_exec_prefix’ is the same as ‘base_prefix’ before
     falling back to searching the Python interpreter directory.

   - gh-127970(3): We now use the location of the ‘libpython’ runtime
     library used in the current process to determine *note
     sys.base_prefix: 3e6. on all platforms implementing the dladdr(4)
     function defined by the UNIX standard — this includes Linux,
     Android, macOS, iOS, FreeBSD, etc.  This was already the case on
     Windows and macOS Framework builds.

   - gh-127773(5): Do not use the type attribute cache for types with
     incompatible *note MRO: 18c5.

   - gh-127903(6): ‘Objects/unicodeobject.c’: fix a crash on DEBUG
     builds in ‘_copy_characters’ when there is nothing to copy.

   - gh-127809(7): Fix an issue where the experimental JIT may infer an
     incorrect result type for exponentiation (‘**’ and ‘**=’), leading
     to bugs or crashes.

   - gh-126862(8): Fix a possible overflow when a class inherits from an
     absurd number of super-classes.  Reported by Valery Fedorenko.
     Patch by Bénédikt Tran.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127274

   (2) https://github.com/python/cpython/issues/66409

   (3) https://github.com/python/cpython/issues/127970

   (4) 
https://pubs.opengroup.org/onlinepubs/9799919799/functions/dladdr.html

   (5) https://github.com/python/cpython/issues/127773

   (6) https://github.com/python/cpython/issues/127903

   (7) https://github.com/python/cpython/issues/127809

   (8) https://github.com/python/cpython/issues/126862


File: python.info,  Node: C API<12>,  Next: Build<12>,  Prev: Core and Builtins<34>,  Up: Python 3 14 0 alpha 4

1.24.15.10 C API
................

   - gh-128400(1): *note Py_FatalError(): b7c. no longer shows all
     threads on the *note free threaded: 1f4. build to prevent crashes.

   - gh-128629(2): Add macros *note Py_PACK_VERSION(): 37f. and *note
     Py_PACK_FULL_VERSION(): 380. for bit-packing Python version
     numbers.

   - gh-128008(3): Add *note PyWeakref_IsDead(): 18c7. function, which
     tests if a weak reference is dead.

   - gh-127350(4): Add *note Py_fopen(): 393. function to open a file.
     Similar to the ‘fopen()’ function, but the 'path' parameter is a
     Python object and an exception is set on error.  Add also *note
     Py_fclose(): 394. function to close a file, function needed for
     Windows support.  Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128400

   (2) https://github.com/python/cpython/issues/128629

   (3) https://github.com/python/cpython/issues/128008

   (4) https://github.com/python/cpython/issues/127350


File: python.info,  Node: Build<12>,  Prev: C API<12>,  Up: Python 3 14 0 alpha 4

1.24.15.11 Build
................

   - gh-128627(1): For Emscripten builds the function pointer cast call
     trampoline now uses the wasm-gc ref.test instruction if it’s
     available instead of Wasm JS type reflection.

   - gh-128472(2): Skip BOLT optimization of functions using computed
     gotos, fixing errors on build with LLVM 19.

   - gh-115765(3): GNU Autoconf 2.72 is now required to generate
     ‘configure’.  Patch by Erlend Aasland.

   - gh-123925(4): Fix building the *note curses: 2f. module on
     platforms with libncurses but without libncursesw.

   - gh-90905(5): Add support for cross-compiling to x86_64 on
     aarch64/arm64 macOS.

   - gh-128321(6): Set ‘LIBS’ instead of ‘LDFLAGS’ when checking if
     *note sqlite3: d4. library functions are available.  This fixes the
     ordering of linked libraries during checks, which was incorrect
     when using a statically linked ‘libsqlite3’.

   - gh-100384(7): Error on ‘unguarded-availability’ in macOS builds,
     preventing invalid use of symbols that are not available in older
     versions of the OS.

   - gh-128104(8): Remove ‘Py_STRFTIME_C99_SUPPORT’ conditions in favor
     of requiring C99 ‘strftime(3)(9)’ specifier support at build time.
     When cross-compiling, there is no build time check and support is
     assumed.

   - gh-127951(10): Add option ‘--pystats’ to the Windows build to
     enable performance statistics collection.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/128627

   (2) https://github.com/python/cpython/issues/128472

   (3) https://github.com/python/cpython/issues/115765

   (4) https://github.com/python/cpython/issues/123925

   (5) https://github.com/python/cpython/issues/90905

   (6) https://github.com/python/cpython/issues/128321

   (7) https://github.com/python/cpython/issues/100384

   (8) https://github.com/python/cpython/issues/128104

   (9) https://manpages.debian.org/strftime(3)

   (10) https://github.com/python/cpython/issues/127951


File: python.info,  Node: Python 3 14 0 alpha 3,  Next: Python 3 14 0 alpha 2,  Prev: Python 3 14 0 alpha 4,  Up: Changelog

1.24.16 Python 3.14.0 alpha 3
-----------------------------

'Release date: 2024-12-17'

* Menu:

* Windows: Windows<11>.
* Tools/Demos: Tools/Demos<13>.
* Tests: Tests<11>.
* Security: Security<14>.
* Library: Library<39>.
* Documentation: Documentation<11>.
* Core and Builtins: Core and Builtins<35>.
* Library: Library<40>.
* Core and Builtins: Core and Builtins<36>.
* C API: C API<13>.
* Build: Build<13>.


File: python.info,  Node: Windows<11>,  Next: Tools/Demos<13>,  Up: Python 3 14 0 alpha 3

1.24.16.1 Windows
.................

   - gh-127353(1): Allow to force color output on Windows using
     environment variables.  Patch by Andrey Efremov.

   - gh-125729(2): Makes the presence of the *note turtle: 107. module
     dependent on the Tcl/Tk installer option.  Previously, the module
     was always installed but would be unusable without Tcl/Tk.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127353

   (2) https://github.com/python/cpython/issues/125729


File: python.info,  Node: Tools/Demos<13>,  Next: Tests<11>,  Prev: Windows<11>,  Up: Python 3 14 0 alpha 3

1.24.16.2 Tools/Demos
.....................

   - gh-126700(1): Add support for multi-argument *note gettext: 67.
     functions in ‘pygettext.py’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126700


File: python.info,  Node: Tests<11>,  Next: Security<14>,  Prev: Tools/Demos<13>,  Up: Python 3 14 0 alpha 3

1.24.16.3 Tests
...............

   - gh-127906(1): Test the limited C API in test_cppext.  Patch by
     Victor Stinner.

   - gh-127637(2): Add tests for the *note dis: 3c. command-line
     interface.  Patch by Bénédikt Tran.

   - gh-126925(3): iOS test results are now streamed during test
     execution, and the deprecated xcresulttool is no longer used.

   - gh-127076(4): Disable strace based system call tests when
     LD_PRELOAD is set.

   - gh-127076(5): Filter out memory-related ‘mmap’, ‘munmap’, and
     ‘mprotect’ calls from file-related ones when testing *note io: 83.
     behavior using strace.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127906

   (2) https://github.com/python/cpython/issues/127637

   (3) https://github.com/python/cpython/issues/126925

   (4) https://github.com/python/cpython/issues/127076

   (5) https://github.com/python/cpython/issues/127076


File: python.info,  Node: Security<14>,  Next: Library<39>,  Prev: Tests<11>,  Up: Python 3 14 0 alpha 3

1.24.16.4 Security
..................

   - gh-127655(1): Fixed the
     ‘asyncio.selector_events._SelectorSocketTransport’ transport not
     pausing writes for the protocol when the buffer reaches the high
     water mark when using *note asyncio.WriteTransport.writelines():
     17b1.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127655


File: python.info,  Node: Library<39>,  Next: Documentation<11>,  Prev: Security<14>,  Up: Python 3 14 0 alpha 3

1.24.16.5 Library
.................

   - gh-126907(1): Fix crash when using *note atexit: d. concurrently on
     the *note free-threaded: 1f4. build.

   - gh-127870(2): Detect recursive calls in ctypes ‘_as_parameter_’
     handling.  Patch by Victor Stinner.

   - gh-127732(3): The *note platform: af. module now correctly detects
     Windows Server 2025.

   - gh-126789(4): Fixed *note sysconfig.get_config_vars(): 298, *note
     sysconfig.get_paths(): 340, and siblings, returning outdated cached
     data if the value of *note sys.prefix: 3e7. or *note
     sys.exec_prefix: 3eb. changes.  Overwriting *note sys.prefix: 3e7.
     or *note sys.exec_prefix: 3eb. still is discouraged, as that might
     break other parts of the code.

   - gh-127718(5): Add colour to *note test.regrtest: e9. output.  Patch
     by Hugo van Kemenade.

   - gh-127610(6): Added validation for more than one var-positional or
     var-keyword parameters in *note inspect.Signature: 4e4.  Patch by
     Maxim Ageev.

   - gh-127627(7): Added ‘posix._emscripten_debugger()’ to help with
     debugging the test suite on the Emscripten target.

   - gh-126821(8): macOS and iOS apps can now choose to redirect stdout
     and stderr to the system log during interpreter configuration.

   - gh-93312(9): Include ‘<sys/pidfd.h>’ to get ‘os.PIDFD_NONBLOCK’
     constant.  Patch by Victor Stinner.

   - gh-127481(10): Add the ‘EPOLLWAKEUP’ constant to the *note select:
     c6. module.

   - gh-127065(11): Make *note operator.methodcaller(): 1036.
     thread-safe and re-entrant safe.

   - gh-127321(12): *note pdb.set_trace(): 272. will not stop at an
     opcode that does not have an associated line number anymore.

   - gh-127429(13): Fixed bug where, on cross-builds, the *note
     sysconfig: e1. POSIX data was being generated with the host
     Python’s ‘Makefile’.  The data is now generated from current
     build’s ‘Makefile’.

   - gh-127413(14): Add the *note dis -specialized: 209. command-line
     option to show specialized bytecode.  Patch by Bénédikt Tran.

   - gh-125413(15): Revert addition of ‘pathlib.Path.scandir()’.  This
     method was added in 3.14.0a2.  The optimizations remain for file
     system paths, but other subclasses should only have to implement
     *note pathlib.Path.iterdir(): 26e.

   - gh-127257(16): In *note ssl: d5, system call failures that OpenSSL
     reports using ‘ERR_LIB_SYS’ are now raised as *note OSError: 2c0.

   - gh-59705(17): On Linux, *note threading.Thread: 176. now sets the
     thread name to the operating system.  Patch by Victor Stinner.

   - gh-127303(18): Publicly expose *note EXACT_TOKEN_TYPES: 18cf. in
     ‘token.__all__’.

   - gh-127331(19): *note ssl: d5. can show descriptions for errors
     added in OpenSSL 3.4.

   - gh-123967(20): Fix faulthandler for trampoline frames.  If the
     top-most frame is a trampoline frame, skip it.  Patch by Victor
     Stinner.

   - gh-127178(21): A ‘_sysconfig_vars_(...).json’ file is now shipped
     in the standard library directory.  It contains the output of *note
     sysconfig.get_config_vars(): 298. on the default environment
     encoded as JSON data.  This is an implementation detail, and may
     change at any time.

   - gh-127072(22): Remove outdated ‘socket.NETLINK_*’ constants not
     present in Linux kernels beyond 2.6.17.

   - gh-127255(23): The *note CopyComPointer(): 1ea. function is now
     public.  Previously, this was private and only available in
     ‘_ctypes’.

   - gh-127182(24): Fix ‘io.StringIO.__setstate__()’ crash, when *note
     None: 886. was passed as the first value.

   - gh-127217(25): Fix *note urllib.request.pathname2url(): 2bf. for
     paths starting with multiple slashes on Posix.

   - gh-125866(26): *note urllib.request.pathname2url(): 2bf. now adds
     an empty authority when generating a URL for a path that begins
     with exactly one slash.  For example, the path ‘/etc/hosts’ is
     converted to the scheme-less URL ‘///etc/hosts’.  As a result of
     this change, URLs without authorities are only generated for
     relative paths.

   - gh-127221(27): Add colour to *note unittest: 10c. output.  Patch by
     Hugo van Kemenade.

   - gh-127035(28): Fix *note shutil.which: 6dc. on Windows.  Now it
     looks at direct match if and only if the command ends with a
     PATHEXT extension or X_OK is not in mode.  Support extensionless
     files if «.» is in PATHEXT. Support PATHEXT extensions that end
     with a dot.

   - gh-122273(29): Support PyREPL history on Windows.  Patch by
     devdanzin and Victor Stinner.

   - gh-125866(30): *note urllib.request.pathname2url(): 2bf. and *note
     url2pathname(): 2bd. no longer convert Windows drive letters to
     uppercase.

   - gh-127078(31): Fix issue where *note urllib.request.url2pathname():
     2bd. failed to discard an extra slash before a UNC drive in the URL
     path on Windows.

   - gh-126766(32): Fix issue where *note urllib.request.url2pathname():
     2bd. failed to discard any “localhost” authority present in the
     URL.

   - gh-127065(33): Fix crash when calling a *note
     operator.methodcaller(): 1036. instance from multiple threads in
     the free threading build.

   - gh-127090(34): Fix value of *note urllib.response.addinfourl.url:
     18d0. for ‘file:’ URLs that express relative paths and absolute
     Windows paths.  The canonical URL generated by *note
     urllib.request.pathname2url(): 2bf. is now used.

   - gh-126992(35): Fix LONG and INT opcodes to only use base 10 for
     string to integer conversion in *note pickle: ab.

   - gh-126997(36): Fix support of STRING and GLOBAL opcodes with
     non-ASCII arguments in *note pickletools: ac.  *note
     pickletools.dis(): ec0. now outputs non-ASCII bytes in STRING,
     BINSTRING and SHORT_BINSTRING arguments as escaped (‘\xXX’).

   - gh-126316(37): *note grp: 6a.: Make *note grp.getgrall(): 18d1.
     thread-safe by adding a mutex.  Patch by Victor Stinner.

   - gh-126618(38): Fix the representation of *note itertools.count:
     148b. objects when the count value is *note sys.maxsize: 13cd.

   - gh-126615(39): The *note COMError: 1e9. exception is now public.
     Previously, this was private and only available in ‘_ctypes’.

   - gh-126985(40): When running under a virtual environment with the
     *note site: cc. disabled (see *note -S: 13b0.), *note sys.prefix:
     3e7. and *note sys.base_prefix: 3e6. will now point to the virtual
     environment, instead of the base installation.

   - gh-112192(41): In the *note trace: 103. module, increase the
     coverage precision (‘cov%’) to one decimal.

   - gh-118761(42): Improve import time of *note mimetypes: 93. by
     around 11-16 times.  Patch by Hugo van Kemenade.

   - gh-126947(43): Raise *note TypeError: 198. in
     ‘_pydatetime.timedelta.__new__()’ if the passed arguments are not
     *note int: 19b. or *note float: 196, so that the Python
     implementation is in line with the C implementation.

   - gh-126946(44): Improve the *note GetoptError: 18d2. error message
     when a long option prefix matches multiple accepted options in
     *note getopt.getopt(): 16c2. and *note getopt.gnu_getopt(): 16c1.

   - gh-126899(45): Make tkinter widget methods ‘after()’ and
     ‘after_idle()’ accept arguments passed by keyword.

   - gh-85168(46): Fix issue where *note urllib.request.url2pathname():
     2bd. and *note pathname2url(): 2bf. always used UTF-8 when quoting
     and unquoting file URIs.  They now use the *note filesystem
     encoding and error handler: 75e.

   - gh-126780(47): Fix *note os.path.normpath(): 1521. for
     drive-relative paths on Windows.

   - gh-126775(48): Make *note linecache.checkcache(): 18d3. thread safe
     and GC re-entrancy safe.

   - gh-126601(49): Fix issue where *note urllib.request.pathname2url():
     2bf. raised *note OSError: 2c0. when given a Windows path
     containing a colon character not following a drive letter, such as
     before an NTFS alternate data stream.

   - gh-126727(50): ‘locale.nl_langinfo(locale.ERA)’ now returns
     multiple era description segments separated by semicolons.
     Previously it only returned the first segment on platforms with
     Glibc.

   - gh-85046(51): Add *note EHWPOISON: 20b. error code to *note errno:
     5b.

   - gh-118201(52): Fixed intermittent failures of *note os.confstr:
     18d4, *note os.pathconf: 1303. and *note os.sysconf: 18d5. on iOS
     and Android.

   - gh-86463(53): The ‘usage’ parameter of *note
     argparse.ArgumentParser: 1bd. no longer affects the default value
     of the ‘prog’ parameter in subparsers.

   - gh-124008(54): Fix possible crash (in debug build), incorrect
     output or returning incorrect value from raw binary ‘write()’ when
     writing to console on Windows.

   - gh-123401(55): The *note http.cookies: 75. module now supports
     parsing obsolete RFC 850(56) date formats, in accordance with RFC
     9110(57) requirements.  Patch by Nano Zheng.

   - gh-122431(58): *note readline.append_history_file(): 1053. now
     raises a *note ValueError: 2ec. when given a negative value.

   - gh-122356(59): Guarantee that the position of a file-like object
     passed to *note zipfile.is_zipfile(): 1532. is left untouched after
     the call.  Patch by Bénédikt Tran.

   - gh-122288(60): Improve the performances of *note
     fnmatch.translate(): 1837. by a factor 1.7.  Patch by Bénédikt
     Tran.

   - gh-88110(61): Fixed *note multiprocessing.Process: 252. reporting a
     ‘.exitcode’ of 1 even on success when using the ‘"fork"’ start
     method while using a *note concurrent.futures.ThreadPoolExecutor:
     94a.

   - gh-97514(62): Authentication was added to the *note
     multiprocessing: 98. forkserver start method control socket so that
     only processes with the authentication key generated by the process
     that spawned the forkserver can control it.  This is an enhancement
     over the other gh-97514(63) fixes so that access is no longer
     limited only by filesystem permissions.

     The file descriptor exchange of control pipes with the forked
     worker process now requires an explicit acknowledgement byte to be
     sent over the socket after the exchange on all forkserver
     supporting platforms.  That makes testing the above much easier.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126907

   (2) https://github.com/python/cpython/issues/127870

   (3) https://github.com/python/cpython/issues/127732

   (4) https://github.com/python/cpython/issues/126789

   (5) https://github.com/python/cpython/issues/127718

   (6) https://github.com/python/cpython/issues/127610

   (7) https://github.com/python/cpython/issues/127627

   (8) https://github.com/python/cpython/issues/126821

   (9) https://github.com/python/cpython/issues/93312

   (10) https://github.com/python/cpython/issues/127481

   (11) https://github.com/python/cpython/issues/127065

   (12) https://github.com/python/cpython/issues/127321

   (13) https://github.com/python/cpython/issues/127429

   (14) https://github.com/python/cpython/issues/127413

   (15) https://github.com/python/cpython/issues/125413

   (16) https://github.com/python/cpython/issues/127257

   (17) https://github.com/python/cpython/issues/59705

   (18) https://github.com/python/cpython/issues/127303

   (19) https://github.com/python/cpython/issues/127331

   (20) https://github.com/python/cpython/issues/123967

   (21) https://github.com/python/cpython/issues/127178

   (22) https://github.com/python/cpython/issues/127072

   (23) https://github.com/python/cpython/issues/127255

   (24) https://github.com/python/cpython/issues/127182

   (25) https://github.com/python/cpython/issues/127217

   (26) https://github.com/python/cpython/issues/125866

   (27) https://github.com/python/cpython/issues/127221

   (28) https://github.com/python/cpython/issues/127035

   (29) https://github.com/python/cpython/issues/122273

   (30) https://github.com/python/cpython/issues/125866

   (31) https://github.com/python/cpython/issues/127078

   (32) https://github.com/python/cpython/issues/126766

   (33) https://github.com/python/cpython/issues/127065

   (34) https://github.com/python/cpython/issues/127090

   (35) https://github.com/python/cpython/issues/126992

   (36) https://github.com/python/cpython/issues/126997

   (37) https://github.com/python/cpython/issues/126316

   (38) https://github.com/python/cpython/issues/126618

   (39) https://github.com/python/cpython/issues/126615

   (40) https://github.com/python/cpython/issues/126985

   (41) https://github.com/python/cpython/issues/112192

   (42) https://github.com/python/cpython/issues/118761

   (43) https://github.com/python/cpython/issues/126947

   (44) https://github.com/python/cpython/issues/126946

   (45) https://github.com/python/cpython/issues/126899

   (46) https://github.com/python/cpython/issues/85168

   (47) https://github.com/python/cpython/issues/126780

   (48) https://github.com/python/cpython/issues/126775

   (49) https://github.com/python/cpython/issues/126601

   (50) https://github.com/python/cpython/issues/126727

   (51) https://github.com/python/cpython/issues/85046

   (52) https://github.com/python/cpython/issues/118201

   (53) https://github.com/python/cpython/issues/86463

   (54) https://github.com/python/cpython/issues/124008

   (55) https://github.com/python/cpython/issues/123401

   (56) https://datatracker.ietf.org/doc/html/rfc850.html

   (57) https://datatracker.ietf.org/doc/html/rfc9110.html

   (58) https://github.com/python/cpython/issues/122431

   (59) https://github.com/python/cpython/issues/122356

   (60) https://github.com/python/cpython/issues/122288

   (61) https://github.com/python/cpython/issues/88110

   (62) https://github.com/python/cpython/issues/97514

   (63) https://github.com/python/cpython/issues/97514


File: python.info,  Node: Documentation<11>,  Next: Core and Builtins<35>,  Prev: Library<39>,  Up: Python 3 14 0 alpha 3

1.24.16.6 Documentation
.......................

   - gh-127347(1): Publicly expose *note traceback.print_list(): 18d7.
     in ‘traceback.__all__’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127347


File: python.info,  Node: Core and Builtins<35>,  Next: Library<40>,  Prev: Documentation<11>,  Up: Python 3 14 0 alpha 3

1.24.16.7 Core and Builtins
...........................

   - gh-127740(1): Fix error message in *note bytes.fromhex(): 190. when
     given an odd number of digits to properly indicate that an even
     number of hexadecimal digits is required.

   - gh-127058(2): ‘PySequence_Tuple’ now creates the resulting tuple
     atomically, preventing partially created tuples being visible to
     the garbage collector or through ‘gc.get_referrers()’

   - gh-127599(3): Fix statistics for increments of object reference
     counts (in particular, when a reference count was increased by more
     than 1 in a single operation).

   - gh-127651(4): When raising *note ImportError: 65b. for missing
     symbols in ‘from’ imports, use ‘__file__’ in the error message if
     ‘__spec__.origin’ is not a location

   - gh-127582(5): Fix non-thread-safe object resurrection when calling
     finalizers and watcher callbacks in the free threading build.

   - gh-127434(6): The iOS compiler shims can now accept arguments with
     spaces.

   - gh-127536(7): Add missing locks around some list assignment
     operations in the free threading build.

   - gh-127085(8): Fix race when exporting a buffer from a *note
     memoryview: 165. object on the *note free-threaded: 1f4. build.

   - gh-127238(9): Correct error message for *note
     sys.set_int_max_str_digits(): 18d9.

   - gh-113841(10): Fix possible undefined behavior division by zero in
     *note complex: 197.’s *note _Py_c_pow(): 18da.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127740

   (2) https://github.com/python/cpython/issues/127058

   (3) https://github.com/python/cpython/issues/127599

   (4) https://github.com/python/cpython/issues/127651

   (5) https://github.com/python/cpython/issues/127582

   (6) https://github.com/python/cpython/issues/127434

   (7) https://github.com/python/cpython/issues/127536

   (8) https://github.com/python/cpython/issues/127085

   (9) https://github.com/python/cpython/issues/127238

   (10) https://github.com/python/cpython/issues/113841


File: python.info,  Node: Library<40>,  Next: Core and Builtins<36>,  Prev: Core and Builtins<35>,  Up: Python 3 14 0 alpha 3

1.24.16.8 Library
.................

   - gh-127133(1): Calling *note
     argparse.ArgumentParser.add_argument_group(): 2eb. on an argument
     group, and calling *note
     argparse.ArgumentParser.add_argument_group(): 2eb. or *note
     argparse.ArgumentParser.add_mutually_exclusive_group(): 2ed. on a
     mutually exclusive group now raise exceptions.  This nesting was
     never supported, often failed to work correctly, and was
     unintentionally exposed through inheritance.  This functionality
     has been deprecated since Python 3.11.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127133


File: python.info,  Node: Core and Builtins<36>,  Next: C API<13>,  Prev: Library<40>,  Up: Python 3 14 0 alpha 3

1.24.16.9 Core and Builtins
...........................

   - gh-126491(1): Add a marking phase to the GC. All objects that can
     be transitively reached from builtin modules or the stacks are
     marked as reachable before cycle detection.  This reduces the
     amount of work done by the GC by approximately half.

   - gh-127020(2): Fix a crash in the free threading build when *note
     PyCode_GetCode(): 97d, *note PyCode_GetVarnames(): 97e, *note
     PyCode_GetCellvars(): 97f, or *note PyCode_GetFreevars(): 980. were
     called from multiple threads at the same time.

   - gh-127010(3): Simplify GC tracking of dictionaries.  All
     dictionaries are tracked when created, rather than being lazily
     tracked when a trackable object was added to them.  This simplifies
     the code considerably and results in a slight speedup.

   - gh-126980(4): Fix *note __buffer__(): 68d. of *note bytearray: 344.
     crashing when *note READ: 18dd. or *note WRITE: 18de. are passed as
     flags.

   - gh-126937(5): Fix *note TypeError: 198. when a *note
     ctypes.Structure: 1e5. has a field size that doesn’t fit into an
     unsigned 16-bit integer.  Instead, the maximum number of 'bits' is
     *note sys.maxsize: 13cd.

   - gh-126868(6): Increase performance of *note int: 19b. by adding a
     freelist for compact ints.

   - gh-126881(7): Fix crash in finalization of dtoa state.  Patch by
     Kumar Aditya.

   - gh-126892(8): Require cold or invalidated code to «warm up» before
     being JIT compiled again.

   - gh-126091(9): Ensure stack traces are complete when throwing into a
     generator chain that ends in a custom generator.

   - gh-126024(10): Optimize decoding of short UTF-8 sequences
     containing non-ASCII characters by approximately 15%.

   - gh-125420(11): Add *note memoryview.index(): 18df. to *note
     memoryview: 165. objects.  Patch by Bénédikt Tran.

   - gh-125420(12): Add *note memoryview.count(): 18e0. to *note
     memoryview: 165. objects.  Patch by Bénédikt Tran.

   - gh-124470(13): Fix crash in free-threaded builds when replacing
     object dictionary while reading attribute on another thread

   - gh-69639(14): Implement mixed-mode arithmetic rules combining real
     and complex numbers as specified by C standards since C99.  Patch
     by Sergey B Kirpichev.

   - gh-120010(15): Correct invalid corner cases which resulted in
     ‘(nan+nanj)’ output in complex multiplication, e.g.,
     ‘(1e300+1j)*(nan+infj)’.  Patch by Sergey B Kirpichev.

   - gh-109746(16): If ‘_thread.start_new_thread()’ fails to start a new
     thread, it deletes its state from interpreter and thus avoids its
     repeated cleanup on finalization.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126491

   (2) https://github.com/python/cpython/issues/127020

   (3) https://github.com/python/cpython/issues/127010

   (4) https://github.com/python/cpython/issues/126980

   (5) https://github.com/python/cpython/issues/126937

   (6) https://github.com/python/cpython/issues/126868

   (7) https://github.com/python/cpython/issues/126881

   (8) https://github.com/python/cpython/issues/126892

   (9) https://github.com/python/cpython/issues/126091

   (10) https://github.com/python/cpython/issues/126024

   (11) https://github.com/python/cpython/issues/125420

   (12) https://github.com/python/cpython/issues/125420

   (13) https://github.com/python/cpython/issues/124470

   (14) https://github.com/python/cpython/issues/69639

   (15) https://github.com/python/cpython/issues/120010

   (16) https://github.com/python/cpython/issues/109746


File: python.info,  Node: C API<13>,  Next: Build<13>,  Prev: Core and Builtins<36>,  Up: Python 3 14 0 alpha 3

1.24.16.10 C API
................

   - gh-127896(1): The previously undocumented function *note
     PySequence_In(): 3d8. is *note soft deprecated: 23d.  Use *note
     PySequence_Contains(): 3d9. instead.

   - gh-127791(2): Fix loss of callbacks after more than one call to
     *note PyUnstable_AtExit(): 18e2.

   - gh-127691(3): The *note Unicode Exception Objects: 461. C API now
     raises a *note TypeError: 198. if its exception argument is not a
     *note UnicodeError: 462. object.  Patch by Bénédikt Tran.

   - gh-123378(4): Ensure that the value of *note
     UnicodeEncodeError.end: 18a9. retrieved by *note
     PyUnicodeEncodeError_GetEnd(): 18e3. lies in ‘[min(1, objlen),
     max(min(1, objlen), objlen)]’ where 'objlen' is the length of *note
     UnicodeEncodeError.object: 18e4.  Similar arguments apply to *note
     UnicodeDecodeError: c0a. and *note UnicodeTranslateError: 18e5. and
     their corresponding C interface.  Patch by Bénédikt Tran.

   - gh-127314(5): Improve error message when calling the C API without
     an active thread state on the *note free-threaded: 1f4. build.

   - gh-123378(6): Ensure that the value of *note
     UnicodeEncodeError.start: 18a8. retrieved by *note
     PyUnicodeEncodeError_GetStart(): 18e6. lies in ‘[0, max(0, objlen -
     1)]’ where 'objlen' is the length of *note
     UnicodeEncodeError.object: 18e4.  Similar arguments apply to *note
     UnicodeDecodeError: c0a. and *note UnicodeTranslateError: 18e5. and
     their corresponding C interface.  Patch by Bénédikt Tran.

   - gh-109523(7): Reading text from a non-blocking stream with ‘read’
     may now raise a *note BlockingIOError: 235. if the operation cannot
     immediately return bytes.

   - gh-102471(8): Add a new import and export API for Python *note int:
     19b. objects ( PEP 757(9)):

        * *note PyLong_GetNativeLayout(): 3a7.;

        * *note PyLong_Export(): 3a8.;

        * *note PyLong_FreeExport(): 3a9.;

        * *note PyLongWriter_Create(): 3aa.;

        * *note PyLongWriter_Finish(): 3ab.;

        * *note PyLongWriter_Discard(): 3ac.

     Patch by Victor Stinner.

   - gh-121058(10): ‘PyThreadState_Clear()’ now warns (and calls
     ‘sys.excepthook’) if the thread state still has an active
     exception.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127896

   (2) https://github.com/python/cpython/issues/127791

   (3) https://github.com/python/cpython/issues/127691

   (4) https://github.com/python/cpython/issues/123378

   (5) https://github.com/python/cpython/issues/127314

   (6) https://github.com/python/cpython/issues/123378

   (7) https://github.com/python/cpython/issues/109523

   (8) https://github.com/python/cpython/issues/102471

   (9) https://peps.python.org/pep-0757/

   (10) https://github.com/python/cpython/issues/121058


File: python.info,  Node: Build<13>,  Prev: C API<13>,  Up: Python 3 14 0 alpha 3

1.24.16.11 Build
................

   - gh-127865(1): Fix build failure on systems without thread-locals
     support.

   - gh-127629(2): Emscripten builds now include ctypes support.

   - gh-127111(3): Updated the Emscripten web example to use ES6 modules
     and be built into a distinct ‘web_example’ subfolder.

   - gh-115869(4): Make ‘jit_stencils.h’ (which is produced during JIT
     builds) reproducible.

   - gh-126898(5): The Emscripten build of Python is now based on ES6
     modules.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/127865

   (2) https://github.com/python/cpython/issues/127629

   (3) https://github.com/python/cpython/issues/127111

   (4) https://github.com/python/cpython/issues/115869

   (5) https://github.com/python/cpython/issues/126898


File: python.info,  Node: Python 3 14 0 alpha 2,  Next: Python 3 14 0 alpha 1,  Prev: Python 3 14 0 alpha 3,  Up: Changelog

1.24.17 Python 3.14.0 alpha 2
-----------------------------

'Release date: 2024-11-19'

* Menu:

* Windows: Windows<12>.
* Tools/Demos: Tools/Demos<14>.
* Tests: Tests<12>.
* Security: Security<15>.
* Library: Library<41>.
* Documentation: Documentation<12>.
* Core and Builtins: Core and Builtins<37>.
* Library: Library<42>.
* Core and Builtins: Core and Builtins<38>.
* Library: Library<43>.
* Core and Builtins: Core and Builtins<39>.
* Library: Library<44>.
* C API: C API<14>.
* Build: Build<14>.


File: python.info,  Node: Windows<12>,  Next: Tools/Demos<14>,  Up: Python 3 14 0 alpha 2

1.24.17.1 Windows
.................

   - gh-126911(1): Update credits command output.

   - gh-118973(2): Ensures the experimental free-threaded install
     includes the ‘_tkinter’ module.  The optional Tcl/Tk component must
     also be installed in order for the module to work.

   - gh-126497(3): Fixes venv failure due to missing redirector
     executables in experimental free-threaded installs.

   - gh-126074(4): Removed unnecessary DLLs from Windows embeddable
     package

   - gh-125315(5): Avoid crashing in *note platform: af. due to slow WMI
     calls on some Windows machines.

   - gh-126084(6): Fix venvwlauncher to launch pythonw instead of python
     so no extra console window is created.

   - gh-125842(7): Fix a *note SystemError: 796. when *note sys.exit():
     277. is called with ‘0xffffffff’ on Windows.

   - gh-125550(8): Enable the *note Python install manager: 7db. to
     detect Python 3.14 installs from the Windows Store.

   - gh-123803(9): All Windows code pages are now supported as «cpXXX»
     codecs on Windows.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126911

   (2) https://github.com/python/cpython/issues/118973

   (3) https://github.com/python/cpython/issues/126497

   (4) https://github.com/python/cpython/issues/126074

   (5) https://github.com/python/cpython/issues/125315

   (6) https://github.com/python/cpython/issues/126084

   (7) https://github.com/python/cpython/issues/125842

   (8) https://github.com/python/cpython/issues/125550

   (9) https://github.com/python/cpython/issues/123803


File: python.info,  Node: Tools/Demos<14>,  Next: Tests<12>,  Prev: Windows<12>,  Up: Python 3 14 0 alpha 2

1.24.17.2 Tools/Demos
.....................

   - gh-126807(1): Fix extraction warnings in ‘pygettext.py’ caused by
     mistaking function definitions for function calls.

   - gh-126167(2): The iOS testbed was modified so that it can be used
     by third-party projects for testing purposes.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126807

   (2) https://github.com/python/cpython/issues/126167


File: python.info,  Node: Tests<12>,  Next: Security<15>,  Prev: Tools/Demos<14>,  Up: Python 3 14 0 alpha 2

1.24.17.3 Tests
...............

   - gh-126909(1): Fix test_os extended attribute tests to work on
     filesystems with 1 KiB xattr size limit.

   - gh-125730(2): Change ‘make test’ to not run GUI tests by default.
     Use ‘make ci’ to run tests with GUI tests instead.

   - gh-124295(3): Add translation tests to the *note argparse: 7.
     module.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126909

   (2) https://github.com/python/cpython/issues/125730

   (3) https://github.com/python/cpython/issues/124295


File: python.info,  Node: Security<15>,  Next: Library<41>,  Prev: Tests<12>,  Up: Python 3 14 0 alpha 2

1.24.17.4 Security
..................

   - gh-126623(1): Upgrade libexpat to 2.6.4

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126623


File: python.info,  Node: Library<41>,  Next: Documentation<12>,  Prev: Security<15>,  Up: Python 3 14 0 alpha 2

1.24.17.5 Library
.................

   - gh-85957(1): Add missing MIME types for images with RFCs: emf,
     fits, g3fax, jp2, jpm, jpx, t38, tiff-fx and wmf.  Patch by Hugo
     van Kemenade.

   - gh-126920(2): Fix the ‘prefix’ and ‘exec_prefix’ keys from *note
     sysconfig.get_config_vars(): 298. incorrectly having the same value
     as *note sys.base_prefix: 3e6. and *note sys.base_exec_prefix: 3ea,
     respectively, inside virtual environments.  They now accurately
     reflect *note sys.prefix: 3e7. and *note sys.exec_prefix: 3eb.

   - gh-67877(3): Fix memory leaks when *note regular expression: be.
     matching terminates abruptly, either because of a signal or because
     memory allocation fails.

   - gh-125063(4): *note marshal: 91. now supports *note slice: 695.
     objects.  The marshal format version was increased to 5.

   - gh-126789(5): Fixed the values of *note
     sysconfig.get_config_vars(): 298, *note sysconfig.get_paths(): 340,
     and their siblings when the *note site: cc. initialization happens
     after *note sysconfig: e1. has built a cache for *note
     sysconfig.get_config_vars(): 298.

   - gh-126188(6): Update bundled pip to 24.3.1

   - gh-126766(7): Fix issue where *note urllib.request.url2pathname():
     2bd. failed to discard two leading slashes introducing an empty
     authority section.

   - gh-126705(8): Allow *note os.PathLike: e4d. to be a base for
     Protocols.

   - gh-126699(9): Allow *note collections.abc.AsyncIterator: fe0. to be
     a base for Protocols.

   - gh-126654(10): Fix crash when non-dict was passed to several
     functions in ‘_interpreters’ module.

   - gh-104745(11): Limit starting a patcher (from *note
     unittest.mock.patch(): 1094. or *note unittest.mock.patch.object():
     18ee.) more than once without stopping it

   - gh-126595(12): Fix a crash when instantiating *note
     itertools.count: 148b. with an initial count of *note sys.maxsize:
     13cd. on debug builds.  Patch by Bénédikt Tran.

   - gh-120423(13): Fix issue where *note urllib.request.pathname2url():
     2bf. mishandled Windows paths with embedded forward slashes.

   - gh-126565(14): Improve performances of *note zipfile.Path.open():
     18ef. for non-reading modes.

   - gh-126505(15): Fix bugs in compiling case-insensitive *note regular
     expressions: be. with character classes containing non-BMP
     characters: upper-case non-BMP character did was ignored and the
     ASCII flag was ignored when matching a character range whose upper
     bound is beyond the BMP region.

   - gh-117378(16): Fixed the *note multiprocessing: 98. ‘"forkserver"’
     start method forkserver process to correctly inherit the parent’s
     *note sys.path: 3e4. during the importing of *note
     multiprocessing.set_forkserver_preload(): 18f0. modules in the same
     manner as *note sys.path: 3e4. is configured in workers before
     executing work items.

     This bug caused some forkserver module preloading to silently fail
     to preload.  This manifested as a performance degradation in child
     processes when the ‘sys.path’ was required due to additional
     repeated work in every worker.

     It could also have a side effect of ‘""’ remaining in *note
     sys.path: 3e4. during forkserver preload imports instead of the
     absolute path from *note os.getcwd(): 18f1. at multiprocessing
     import time used in the worker ‘sys.path’.

     The ‘sys.path’ differences between phases in the child process
     could potentially have caused preload to import incorrect things
     from the wrong location.  We are unaware of that actually having
     happened in practice.

   - gh-125679(17): The *note multiprocessing.Lock: 183b. and *note
     multiprocessing.RLock: 183c. ‘repr’ values no longer say «unknown»
     on macOS.

   - gh-126476(18): Raise *note calendar.IllegalMonthError: 18f2. (now a
     subclass of *note IndexError: 173c.) for *note calendar.month():
     18f3. when the input month is not correct.

   - gh-126489(19): The Python implementation of *note pickle: ab. no
     longer calls *note pickle.Pickler.persistent_id(): 18f4. for the
     result of ‘persistent_id()’.

   - gh-126451(20): Register the *note contextvars.Context: 177. type to
     *note collections.abc.Mapping: ac9.

   - gh-126175(21): Add ‘msg’, ‘doc’, ‘pos’, ‘lineno’ and ‘colno’
     attributes to *note tomllib.TOMLDecodeError: 18f5.  Deprecate
     instantiating with free-form arguments.

   - gh-89416(22): Add RFC 9559(23) MIME types for Matroska audiovisual
     container formats.  Patch by Hugo van Kemenade.

   - gh-126417(24): Register the ‘multiprocessing.managers.DictProxy’
     and ‘multiprocessing.managers.ListProxy’ types in *note
     multiprocessing.managers: 9b. to *note
     collections.abc.MutableMapping: 12b4. and *note
     collections.abc.MutableSequence: 4c0, respectively.

   - gh-126390(25): Add support for returning intermixed options and
     non-option arguments in order in *note getopt.gnu_getopt(): 16c1.

   - gh-126374(26): Add support for options with optional arguments in
     the *note getopt: 65. module.

   - gh-126363(27): Speed up pattern parsing in *note
     pathlib.Path.glob(): 538. by skipping creation of a *note
     pathlib.Path: 266. object for the pattern.

   - gh-126353(28): *note asyncio.get_event_loop(): 2f2. now does not
     implicitly creates an event loop.  It now raises a *note
     RuntimeError: 244. if there is no set event loop.  Patch by Kumar
     Aditya.

   - gh-126313(29): Fix an issue in *note curses.napms(): 18f6. when
     *note curses.initscr(): 18f7. has not yet been called.  Patch by
     Bénédikt Tran.

   - gh-126303(30): Fix pickling and copying of *note os.sched_param:
     18f8. objects.

   - gh-126138(31): Fix a use-after-free crash on *note asyncio.Task:
     1c7. objects whose underlying coroutine yields an object that
     implements an evil *note __getattribute__(): dcd.  Patch by Nico
     Posada.

   - gh-120057(32): Replace the ‘os.environ.refresh()’ method with a new
     *note os.reload_environ(): 258. function.  Patch by Victor Stinner.

   - gh-126220(33): Fix crash in ‘cProfile.Profile’ and
     ‘_lsprof.Profiler’ when their callbacks were directly called with 0
     arguments.

   - gh-126212(34): Fix issue where *note urllib.request.pathname2url():
     2bf. and *note url2pathname(): 2bd. removed slashes from Windows
     DOS drive paths and URLs.

   - gh-126223(35): Raise a *note UnicodeEncodeError: 888. instead of a
     *note SystemError: 796. upon calling ‘_interpreters.create()’ with
     an invalid Unicode character.

   - gh-126205(36): Fix issue where *note urllib.request.pathname2url():
     2bf. generated URLs beginning with four slashes (rather than two)
     when given a Windows UNC path.

   - gh-126156(37): Improved performances of creating *note Morsel: e00.
     objects by a factor of 3.8x.

   - gh-126105(38): Fix a crash in *note ast: 9. when the *note
     ast.AST._fields: 17bf. attribute is deleted.

   - gh-126106(39): Fixes a possible ‘NULL’ pointer dereference in *note
     ssl: d5.

   - gh-126080(40): Fix a use-after-free crash on *note asyncio.Task:
     1c7. objects for which the underlying event loop implements an evil
     *note __getattribute__(): dcd.  Reported by Nico-Posada.  Patch by
     Bénédikt Tran.

   - gh-125322(41): Correct detection of complex numbers support in
     libffi.

   - gh-126083(42): Fixed a reference leak in *note asyncio.Task: 1c7.
     objects when reinitializing the same object with a non-‘None’
     context.  Patch by Nico Posada.

   - gh-126068(43): Fix exceptions in the *note argparse: 7. module so
     that only error messages for ArgumentError and ArgumentTypeError
     are now translated.  ArgumentError is now only used for command
     line errors, not for logical errors in the program.  TypeError is
     now raised instead of ValueError for some logical errors.

   - gh-125413(44): Add ‘pathlib.Path.scandir()’ method to efficiently
     fetch directory children and their file attributes.  This is a
     trivial wrapper of *note os.scandir(): c56.

   - gh-125984(45): Fix use-after-free crashes on *note asyncio.Future:
     dc8. objects for which the underlying event loop implements an evil
     *note __getattribute__(): dcd.  Reported by Nico-Posada.  Patch by
     Bénédikt Tran.

   - gh-125926(46): Fix *note urllib.parse.urljoin(): 1098. for base URI
     with undefined authority.  Although RFC 3986(47) only specify
     reference resolution for absolute base URI, ‘urljoin()’ should
     continue to return sensible result for relative base URI.

   - gh-125969(48): Fix an out-of-bounds crash when an evil *note
     asyncio.loop.call_soon(): cfc. mutates the length of the internal
     callbacks list.  Patch by Bénédikt Tran.

   - gh-125966(49): Fix a use-after-free crash in *note
     asyncio.Future.remove_done_callback(): 18f9.  Patch by Bénédikt
     Tran.

   - gh-125789(50): Fix possible crash when mutating list of callbacks
     returned by ‘asyncio.Future._callbacks’.  It now always returns a
     new copy in C implementation ‘_asyncio’.  Patch by Kumar Aditya.

   - gh-126916(51): Allow the 'initial' parameter of *note
     functools.reduce(): 21a. to be passed as a keyword argument.  Patch
     by Sayandip Dutta.

   - gh-124452(52): Fix an issue in *note
     email.policy.EmailPolicy.header_source_parse(): 18fa. and *note
     email.policy.Compat32.header_source_parse(): 18fb. that introduced
     spurious leading whitespaces into header values when the header
     includes a newline character after the header name delimiter (‘:’)
     and before the value.

   - gh-117941(53): ‘argparse.BooleanOptionalAction’ now rejects option
     names starting with ‘--no-’.

   - gh-125884(54): Fixed the bug for *note pdb: aa. where it can’t set
     breakpoints on functions with certain annotations.

   - gh-125355(55): Fix several bugs in *note
     argparse.ArgumentParser.parse_intermixed_args(): cf9.

        * The parser no longer changes temporarily during parsing.

        * Default values are not processed twice.

        * Required mutually exclusive groups containing positional
          arguments are now supported.

        * The missing arguments report now includes the names of all
          required optional and positional arguments.

        * Unknown options can be intermixed with positional arguments in
          parse_known_intermixed_args().

   - gh-125767(56): *note super: 1a6. objects are now *note pickleable:
     ab. and *note copyable: 29.

   - gh-124969(57): ‘locale.nl_langinfo(locale.ALT_DIGITS)’ now returns
     a string again.  The returned value consists of up to 100
     semicolon-separated symbols.

   - gh-84850(58): Remove ‘URLopener’ and ‘FancyURLopener’ classes from
     *note urllib.request: 111.  They had previously raised *note
     DeprecationWarning: 1a3. since Python 3.3.

   - gh-125666(59): Avoid the exiting the interpreter if a null byte is
     given as input in the new REPL.

   - gh-125710(60): [Enum] fix hashable<->nonhashable comparisons for
     member values

   - gh-125631(61): Restore ability to set *note persistent_id: 18f4.
     and *note persistent_load: 18fc. attributes of instances of the
     ‘Pickler’ and ‘Unpickler’ classes in the *note pickle: ab. module.

   - gh-125378(62): Fixed the bug in *note pdb: aa. where after a
     multi-line command, an empty line repeats the first line of the
     multi-line command, instead of the full command.

   - gh-125682(63): Reject non-ASCII digits in the Python implementation
     of *note json.loads(): b50. conforming to the JSON specification.

   - gh-125660(64): Reject invalid unicode escapes for Python
     implementation of *note json.loads(): b50.

   - gh-52551(65): Use ‘wcsftime()’ to implement *note time.strftime():
     13f1. on Windows.

   - gh-125259(66): Fix the notes removal logic for errors thrown in
     enum initialization.

   - gh-125633(67): Add function *note inspect.ispackage(): 232. to
     determine whether an object is a *note package: 233. or not.

   - gh-125614(68): In the *note FORWARDREF: 15f. format of *note
     annotationlib: 6, fix bug where nested expressions were not
     returned as *note annotationlib.ForwardRef: 175d. format.

   - gh-125590(69): Allow ‘FrameLocalsProxy’ to delete and pop if the
     key is not a fast variable.

   - gh-125600(70): Only show stale code warning in *note pdb: aa. when
     we display source code.

   - gh-125542(71): Deprecate passing keyword-only 'prefix_chars'
     argument to *note argparse.ArgumentParser.add_argument_group():
     2eb.

   - gh-125541(72): Pressing ‘Ctrl’-‘C’ while blocked in *note
     threading.Lock.acquire(): 8a8, *note threading.RLock.acquire():
     107d, and *note threading.Thread.join(): 13ec. now interrupts the
     function call and raises a *note KeyboardInterrupt: bc7. exception
     on Windows, similar to how those functions behave on macOS and
     Linux.

   - gh-125519(73): Improve traceback if *note importlib.reload(): 73e.
     is called with an object that is not a module.  Patch by Alex
     Waygood.

   - gh-125451(74): Fix deadlock when *note
     concurrent.futures.ProcessPoolExecutor: 1d6. shuts down
     concurrently with an error when feeding a job to a worker process.

   - gh-125115(75): Fixed a bug in *note pdb: aa. where arguments
     starting with ‘-’ can’t be passed to the debugged script.

   - gh-125398(76): Fix the conversion of the ‘VIRTUAL_ENV’ path in the
     activate script in *note venv: 117. when running in Git Bash for
     Windows.

   - gh-125245(77): Fix race condition when importing *note
     collections.abc: 1f, which could incorrectly return an empty
     module.

   - gh-52551(78): Fix encoding issues in *note time.strftime(): 13f1,
     the *note strftime(): e90. method of the *note datetime: 34.
     classes *note datetime: 4e3, *note date: 1fa. and *note time: 1fb.
     and formatting of these classes.  Characters not encodable in the
     current locale are now acceptable in the format string.  Surrogate
     pairs and sequence of surrogatescape-encoded bytes are no longer
     recombinated.  Embedded null character no longer terminates the
     format string.

   - gh-124984(79): Fixed thread safety in *note ssl: d5. in the
     free-threaded build.  OpenSSL operations are now protected by a
     per-object lock.

   - gh-124651(80): Properly quote template strings in *note venv: 117.
     activation scripts.

   - gh-124694(81): We’ve added *note
     concurrent.futures.InterpreterPoolExecutor: 1d2, which allows you
     to run code in multiple isolated interpreters.  This allows you to
     circumvent the limitations of CPU-bound threads (due to the GIL).
     Patch by Eric Snow.

     This addition is unrelated to PEP 734(82).

   - gh-58032(83): Deprecate the *note argparse.FileType: 30c. type
     converter.

   - gh-99749(84): Adds a feature to optionally enable suggestions for
     argument choices and subparser names if mistyped by the user.

   - gh-58956(85): Fixed a bug in *note pdb: aa. where sometimes the
     breakpoint won’t trigger if it was set on a function which is
     already in the call stack.

   - gh-124111(86): The tkinter module can now be built to use either
     the new version 9.0.0 of Tcl/Tk or the latest release 8.6.15 of
     Tcl/Tk 8.  Tcl/Tk 9 includes many improvements, both to the Tcl
     language and to the appearance and utility of the graphical user
     interface provided by Tk.

   - gh-80958(87): unittest discovery supports PEP 420 namespace
     packages as start directory again.

   - gh-123370(88): Fix the canvas not clearing after running turtledemo
     clock.

   - gh-89083(89): Add *note uuid.uuid8(): 2c4. for generating UUIDv8
     objects as specified in RFC 9562(90).  Patch by Bénédikt Tran

   - gh-122549(91): Add *note platform.invalidate_caches(): 27d. to
     invalidate cached results.

   - gh-120754(92): Update unbounded ‘read’ calls in *note zipfile: 137.
     to specify an explicit ‘size’ putting a limit on how much data they
     may read.  This also updates handling around ZIP max comment size
     to match the standard instead of reading comments that are one byte
     too long.

   - gh-121267(93): Improve the performance of *note tarfile: e4. when
     writing files, by caching user names and group names.

   - gh-70764(94): Fixed an issue where *note inspect.getclosurevars():
     12dd. would incorrectly classify an attribute name as a global
     variable when the name exists both as an attribute name and a
     global variable.

   - gh-118289(95): ‘posixpath.realpath()’ now raises *note
     NotADirectoryError: 125c. when 'strict' mode is enabled and a
     non-directory path with a trailing slash is supplied.

   - gh-119826(96): Always return an absolute path for *note
     os.path.abspath(): 1522. on Windows.

   - gh-97850(97): Remove deprecated ‘pkgutil.get_loader()’ and
     ‘pkgutil.find_loader()’.

   - gh-118986(98): Add ‘socket.IPV6_RECVERR’ constant (available since
     Linux 2.2).

   - gh-116897(99): Accepting objects with false values (like ‘0’ and
     ‘[]’) except empty strings, byte-like objects and ‘None’ in *note
     urllib.parse: 110. functions *note parse_qsl(): 31e. and *note
     parse_qs(): 31f. is now deprecated.

   - gh-101955(100): Fix SystemError when match regular expression
     pattern containing some combination of possessive quantifier,
     alternative and capture group.

   - gh-71936(101): Fix a race condition in *note
     multiprocessing.pool.Pool: 116d.

   - bpo-46128(102): Strip *note unittest.IsolatedAsyncioTestCase: 361.
     stack frames from reported stacktraces.

   - gh-84852(103): Add MIME types for MS Embedded OpenType, OpenType
     Layout, TrueType, WOFF 1.0 and 2.0 fonts.  Patch by Sahil Prajapati
     and Hugo van Kemenade.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/85957

   (2) https://github.com/python/cpython/issues/126920

   (3) https://github.com/python/cpython/issues/67877

   (4) https://github.com/python/cpython/issues/125063

   (5) https://github.com/python/cpython/issues/126789

   (6) https://github.com/python/cpython/issues/126188

   (7) https://github.com/python/cpython/issues/126766

   (8) https://github.com/python/cpython/issues/126705

   (9) https://github.com/python/cpython/issues/126699

   (10) https://github.com/python/cpython/issues/126654

   (11) https://github.com/python/cpython/issues/104745

   (12) https://github.com/python/cpython/issues/126595

   (13) https://github.com/python/cpython/issues/120423

   (14) https://github.com/python/cpython/issues/126565

   (15) https://github.com/python/cpython/issues/126505

   (16) https://github.com/python/cpython/issues/117378

   (17) https://github.com/python/cpython/issues/125679

   (18) https://github.com/python/cpython/issues/126476

   (19) https://github.com/python/cpython/issues/126489

   (20) https://github.com/python/cpython/issues/126451

   (21) https://github.com/python/cpython/issues/126175

   (22) https://github.com/python/cpython/issues/89416

   (23) https://datatracker.ietf.org/doc/html/rfc9559.html

   (24) https://github.com/python/cpython/issues/126417

   (25) https://github.com/python/cpython/issues/126390

   (26) https://github.com/python/cpython/issues/126374

   (27) https://github.com/python/cpython/issues/126363

   (28) https://github.com/python/cpython/issues/126353

   (29) https://github.com/python/cpython/issues/126313

   (30) https://github.com/python/cpython/issues/126303

   (31) https://github.com/python/cpython/issues/126138

   (32) https://github.com/python/cpython/issues/120057

   (33) https://github.com/python/cpython/issues/126220

   (34) https://github.com/python/cpython/issues/126212

   (35) https://github.com/python/cpython/issues/126223

   (36) https://github.com/python/cpython/issues/126205

   (37) https://github.com/python/cpython/issues/126156

   (38) https://github.com/python/cpython/issues/126105

   (39) https://github.com/python/cpython/issues/126106

   (40) https://github.com/python/cpython/issues/126080

   (41) https://github.com/python/cpython/issues/125322

   (42) https://github.com/python/cpython/issues/126083

   (43) https://github.com/python/cpython/issues/126068

   (44) https://github.com/python/cpython/issues/125413

   (45) https://github.com/python/cpython/issues/125984

   (46) https://github.com/python/cpython/issues/125926

   (47) https://datatracker.ietf.org/doc/html/rfc3986.html

   (48) https://github.com/python/cpython/issues/125969

   (49) https://github.com/python/cpython/issues/125966

   (50) https://github.com/python/cpython/issues/125789

   (51) https://github.com/python/cpython/issues/126916

   (52) https://github.com/python/cpython/issues/124452

   (53) https://github.com/python/cpython/issues/117941

   (54) https://github.com/python/cpython/issues/125884

   (55) https://github.com/python/cpython/issues/125355

   (56) https://github.com/python/cpython/issues/125767

   (57) https://github.com/python/cpython/issues/124969

   (58) https://github.com/python/cpython/issues/84850

   (59) https://github.com/python/cpython/issues/125666

   (60) https://github.com/python/cpython/issues/125710

   (61) https://github.com/python/cpython/issues/125631

   (62) https://github.com/python/cpython/issues/125378

   (63) https://github.com/python/cpython/issues/125682

   (64) https://github.com/python/cpython/issues/125660

   (65) https://github.com/python/cpython/issues/52551

   (66) https://github.com/python/cpython/issues/125259

   (67) https://github.com/python/cpython/issues/125633

   (68) https://github.com/python/cpython/issues/125614

   (69) https://github.com/python/cpython/issues/125590

   (70) https://github.com/python/cpython/issues/125600

   (71) https://github.com/python/cpython/issues/125542

   (72) https://github.com/python/cpython/issues/125541

   (73) https://github.com/python/cpython/issues/125519

   (74) https://github.com/python/cpython/issues/125451

   (75) https://github.com/python/cpython/issues/125115

   (76) https://github.com/python/cpython/issues/125398

   (77) https://github.com/python/cpython/issues/125245

   (78) https://github.com/python/cpython/issues/52551

   (79) https://github.com/python/cpython/issues/124984

   (80) https://github.com/python/cpython/issues/124651

   (81) https://github.com/python/cpython/issues/124694

   (82) https://peps.python.org/pep-0734/

   (83) https://github.com/python/cpython/issues/58032

   (84) https://github.com/python/cpython/issues/99749

   (85) https://github.com/python/cpython/issues/58956

   (86) https://github.com/python/cpython/issues/124111

   (87) https://github.com/python/cpython/issues/80958

   (88) https://github.com/python/cpython/issues/123370

   (89) https://github.com/python/cpython/issues/89083

   (90) https://datatracker.ietf.org/doc/html/rfc9562.html

   (91) https://github.com/python/cpython/issues/122549

   (92) https://github.com/python/cpython/issues/120754

   (93) https://github.com/python/cpython/issues/121267

   (94) https://github.com/python/cpython/issues/70764

   (95) https://github.com/python/cpython/issues/118289

   (96) https://github.com/python/cpython/issues/119826

   (97) https://github.com/python/cpython/issues/97850

   (98) https://github.com/python/cpython/issues/118986

   (99) https://github.com/python/cpython/issues/116897

   (100) https://github.com/python/cpython/issues/101955

   (101) https://github.com/python/cpython/issues/71936

   (102) https://bugs.python.org/issue?@action=redirect&bpo=46128

   (103) https://github.com/python/cpython/issues/84852


File: python.info,  Node: Documentation<12>,  Next: Core and Builtins<37>,  Prev: Library<41>,  Up: Python 3 14 0 alpha 2

1.24.17.6 Documentation
.......................

   - gh-126622(1): Added stub pages for removed modules explaining their
     removal, where to find replacements, and linking to the last Python
     version that supported them.  Contributed by Ned Batchelder.

   - gh-125277(2): Require Sphinx 7.2.6 or later to build the Python
     documentation.  Patch by Adam Turner.

   - gh-60712(3): Include the *note object: c80. type in the lists of
     documented types.  Change by Furkan Onder and Martin Panter.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126622

   (2) https://github.com/python/cpython/issues/125277

   (3) https://github.com/python/cpython/issues/60712


File: python.info,  Node: Core and Builtins<37>,  Next: Library<42>,  Prev: Documentation<12>,  Up: Python 3 14 0 alpha 2

1.24.17.7 Core and Builtins
...........................

   - gh-126795(1): Increase the threshold for JIT code warmup.
     Depending on platform and workload, this can result in performance
     gains of 1-9% and memory savings of 3-5%.

   - gh-126341(2): Now *note ValueError: 2ec. is raised instead of *note
     SystemError: 796. when trying to iterate over a released *note
     memoryview: 165. object.

   - gh-126688(3): Fix a crash when calling *note os.fork(): 4b6. on
     some operating systems, including SerenityOS.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126795

   (2) https://github.com/python/cpython/issues/126341

   (3) https://github.com/python/cpython/issues/126688


File: python.info,  Node: Library<42>,  Next: Core and Builtins<38>,  Prev: Core and Builtins<37>,  Up: Python 3 14 0 alpha 2

1.24.17.8 Library
.................

   - gh-126066(1): Fix *note importlib: 7b. to not write an incomplete
     .pyc files when a ulimit or some other operating system mechanism
     is preventing the write to go through fully.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126066


File: python.info,  Node: Core and Builtins<38>,  Next: Library<43>,  Prev: Library<42>,  Up: Python 3 14 0 alpha 2

1.24.17.9 Core and Builtins
...........................

   - gh-126222(1): Do not include count of «peek» items in
     ‘_PyUop_num_popped’.  This ensures that the correct number of items
     are popped from the stack when a micro-op exits with an error.

   - gh-126366(2): Fix crash when using ‘yield from’ on an object that
     raises an exception in its ‘__iter__’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126222

   (2) https://github.com/python/cpython/issues/126366


File: python.info,  Node: Library<43>,  Next: Core and Builtins<39>,  Prev: Core and Builtins<38>,  Up: Python 3 14 0 alpha 2

1.24.17.10 Library
..................

   - gh-126209(1): Fix an issue with ‘skip_file_prefixes’ parameter
     which resulted in an inconsistent behaviour between the C and
     Python implementations of *note warnings.warn(): 1720.  Patch by
     Daehee Kim.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126209


File: python.info,  Node: Core and Builtins<39>,  Next: Library<44>,  Prev: Library<43>,  Up: Python 3 14 0 alpha 2

1.24.17.11 Core and Builtins
............................

   - gh-126312(1): Fix crash during garbage collection on an object
     frozen by *note gc.freeze(): d30. on the free-threaded build.

   - gh-103951(2): Relax optimization requirements to allow fast
     attribute access to module subclasses.

   - gh-126072(3): Following gh-126101(4), for *note Code Objects: 7d3.
     like lambda, annotation and type alias, we no longer add ‘None’ to
     its *note co_consts: 1883.

   - gh-126195(5): Improve JIT performance by 1.4% on macOS Apple
     Silicon by using platform-specific memory protection APIs.  Patch
     by Diego Russo.

   - gh-126139(6): Provide better error location when attempting to use
     a *note future statement: faf. with an unknown future feature.

   - gh-126072(7): Add a new attribute in *note co_flags: 18c3. to
     indicate whether the first item in *note co_consts: 1883. is the
     docstring.  If a code object has no docstring, ‘None’ will 'NOT' be
     inserted.

   - gh-126076(8): Relocated objects such as ‘tuple’, ‘bytes’ and ‘str’
     objects are properly tracked by *note tracemalloc: 105. and its
     associated hooks.  Patch by Pablo Galindo.

   - gh-90370(9): Avoid temporary tuple creation for vararg in argument
     passing with Argument Clinic generated code (if arguments either
     vararg or positional-only).

   - gh-126018(10): Fix a crash in *note sys.audit(): 1903. when passing
     a non-string as first argument and Python was compiled in debug
     mode.

   - gh-126012(11): The *note memoryview: 165. type now supports
     subscription, making it a *note generic type: 1a1.

   - gh-125837(12): Adds *note LOAD_SMALL_INT: 36e. and *note
     LOAD_CONST_IMMORTAL: 375. instructions.  ‘LOAD_SMALL_INT’ pushes a
     small integer equal to the ‘oparg’ to the stack.
     ‘LOAD_CONST_IMMORTAL’ does the same as ‘LOAD_CONST’ but is more
     efficient for immortal objects.  Removes ‘RETURN_CONST’
     instruction.

   - gh-125942(13): On Android, the ‘errors’ setting of *note
     sys.stdout: ccf. was changed from ‘surrogateescape’ to
     ‘backslashreplace’.

   - gh-125859(14): Fix a crash in the free threading build when *note
     gc.get_objects(): a06. or *note gc.get_referrers(): a07. is called
     during an in-progress garbage collection.

   - gh-125868(15): It was possible in 3.14.0a1 only for attribute
     lookup to give the wrong value.  This was due to an incorrect
     specialization in very specific circumstances.  This is fixed in
     3.14.0a2.

   - gh-125498(16): The JIT has been updated to leverage Clang 19’s new
     ‘preserve_none’ attribute, which supports more platforms and is
     more useful than LLVM’s existing ‘ghccc’ calling convention.  This
     also removes the need to manually patch the calling convention in
     LLVM IR, simplifying the JIT compilation process.

   - gh-125703(17): Correctly honour *note tracemalloc: 105. hooks in
     specialized ‘Py_DECREF’ paths.  Patch by Pablo Galindo

   - gh-125593(18): Use color to highlight error locations in traceback
     from exception group

   - gh-125017(19): Fix crash on certain accesses to the
     ‘__annotations__’ of *note staticmethod: 453. and *note
     classmethod: 48f. objects.

   - gh-125588(20): The Python PEG generator can now use f-strings in
     the grammar actions.  Patch by Pablo Galindo

   - gh-125444(21): Fix illegal instruction for older Arm architectures.
     Patch by Diego Russo, testing by Ross Burton.

   - gh-118423(22): Add a new ‘INSTRUCTION_SIZE’ macro to the cases
     generator which returns the current instruction size.

   - gh-125038(23): Fix crash when iterating over a generator expression
     after direct changes on ‘gi_frame.f_locals’.  Patch by Mikhail
     Efimov.

   - gh-124855(24): Don’t allow the JIT and perf support to be active at
     the same time.  Patch by Pablo Galindo

   - gh-123714(25): Update JIT compilation to use LLVM 19

   - gh-123930(26): Improve the error message when a script shadowing a
     module from the standard library causes *note ImportError: 65b. to
     be raised during a «from» import.  Similarly, improve the error
     message when a script shadowing a third party module attempts to
     «from» import an attribute from that third party module while still
     initialising.

   - gh-119793(27): The *note map(): 19f. built-in now has an optional
     keyword-only 'strict' flag like *note zip(): 1a0. to check that all
     the iterables are of equal length.  Patch by Wannes Boeykens.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126312

   (2) https://github.com/python/cpython/issues/103951

   (3) https://github.com/python/cpython/issues/126072

   (4) https://github.com/python/cpython/issues/126101

   (5) https://github.com/python/cpython/issues/126195

   (6) https://github.com/python/cpython/issues/126139

   (7) https://github.com/python/cpython/issues/126072

   (8) https://github.com/python/cpython/issues/126076

   (9) https://github.com/python/cpython/issues/90370

   (10) https://github.com/python/cpython/issues/126018

   (11) https://github.com/python/cpython/issues/126012

   (12) https://github.com/python/cpython/issues/125837

   (13) https://github.com/python/cpython/issues/125942

   (14) https://github.com/python/cpython/issues/125859

   (15) https://github.com/python/cpython/issues/125868

   (16) https://github.com/python/cpython/issues/125498

   (17) https://github.com/python/cpython/issues/125703

   (18) https://github.com/python/cpython/issues/125593

   (19) https://github.com/python/cpython/issues/125017

   (20) https://github.com/python/cpython/issues/125588

   (21) https://github.com/python/cpython/issues/125444

   (22) https://github.com/python/cpython/issues/118423

   (23) https://github.com/python/cpython/issues/125038

   (24) https://github.com/python/cpython/issues/124855

   (25) https://github.com/python/cpython/issues/123714

   (26) https://github.com/python/cpython/issues/123930

   (27) https://github.com/python/cpython/issues/119793


File: python.info,  Node: Library<44>,  Next: C API<14>,  Prev: Core and Builtins<39>,  Up: Python 3 14 0 alpha 2

1.24.17.12 Library
..................

   - gh-118950(1): Fix bug where SSLProtocol.connection_lost wasn’t
     getting called when OSError was thrown on writing to socket.

   - gh-113570(2): Fixed a bug in ‘reprlib.repr’ where it incorrectly
     called the repr method on shadowed Python built-in types.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118950

   (2) https://github.com/python/cpython/issues/113570


File: python.info,  Node: C API<14>,  Next: Build<14>,  Prev: Library<44>,  Up: Python 3 14 0 alpha 2

1.24.17.13 C API
................

   - gh-126554(1): Fix error handling in *note ctypes.CDLL: bde. objects
     which could result in a crash in rare situations.

   - gh-126061(2): Add *note PyLong_IsPositive(): 39b, *note
     PyLong_IsNegative(): 39c. and *note PyLong_IsZero(): 39d. for
     checking if a *note PyLongObject: 39e. is positive, negative, or
     zero, respectively.

   - gh-125608(3): Fix a bug where dictionary watchers (e.g., *note
     PyDict_Watch(): 785.) on an object’s attribute dictionary (*note
     __dict__: 77e.) were not triggered when the object’s attributes
     were modified.

   - gh-123619(4): Added the *note
     PyUnstable_Object_EnableDeferredRefcount(): 3c5. function for
     enabling PEP 703(5) deferred reference counting.

   - gh-121654(6): Add *note PyType_Freeze(): 3af. function to make a
     type immutable.  Patch by Victor Stinner.

   - gh-120026(7): The ‘Py_HUGE_VAL’ macro is *note soft deprecated:
     23d.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126554

   (2) https://github.com/python/cpython/issues/126061

   (3) https://github.com/python/cpython/issues/125608

   (4) https://github.com/python/cpython/issues/123619

   (5) https://peps.python.org/pep-0703/

   (6) https://github.com/python/cpython/issues/121654

   (7) https://github.com/python/cpython/issues/120026


File: python.info,  Node: Build<14>,  Prev: C API<14>,  Up: Python 3 14 0 alpha 2

1.24.17.14 Build
................

   - gh-126691(1): Removed the ‘--with-emscripten-target’ configure
     flag.  We unified the ‘node’ and ‘browser’ options and the same
     build can now be used, independent of target runtime.

   - gh-123877(2): Use ‘wasm32-wasip1’ as the target triple for WASI
     instead of ‘wasm32-wasi’.  The latter will eventually be reclaimed
     for WASI 1.0 while CPython currently only supports WASI preview1.

   - gh-126458(3): Disable SIMD support for HACL under WASI.

   - gh-89640(4): Hard-code float word ordering as little endian on
     WASM.

   - gh-126206(5): ‘make clinic’ now runs Argument Clinic using the
     ‘--force’ option, thus forcefully regenerating generated code.

   - gh-126187(6): Introduced ‘Tools/wasm/emscripten.py’ to simplify
     doing Emscripten builds.

   - gh-124932(7): For cross builds, there is now support for having a
     different install ‘prefix’ than the ‘host_prefix’ used by
     ‘getpath.py’.  This is set to ‘/’ by default for Emscripten, on
     other platforms the default behavior is the same as before.

   - gh-125946(8): The minimum supported Android version is now 7.0 (API
     level 24).

   - gh-125940(9): The Android build now supports 16 KB page sizes(10).

   - gh-89640(11): Improve detection of float word ordering on Linux
     when link-time optimizations are enabled.

   - gh-124928(12): Emscripten builds now require node >= 18.

   - gh-115382(13): Fix cross compile failures when the host and target
     SOABIs match.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/126691

   (2) https://github.com/python/cpython/issues/123877

   (3) https://github.com/python/cpython/issues/126458

   (4) https://github.com/python/cpython/issues/89640

   (5) https://github.com/python/cpython/issues/126206

   (6) https://github.com/python/cpython/issues/126187

   (7) https://github.com/python/cpython/issues/124932

   (8) https://github.com/python/cpython/issues/125946

   (9) https://github.com/python/cpython/issues/125940

   (10) https://developer.android.com/guide/practices/page-sizes

   (11) https://github.com/python/cpython/issues/89640

   (12) https://github.com/python/cpython/issues/124928

   (13) https://github.com/python/cpython/issues/115382


File: python.info,  Node: Python 3 14 0 alpha 1,  Next: Python 3 13 0 beta 1,  Prev: Python 3 14 0 alpha 2,  Up: Changelog

1.24.18 Python 3.14.0 alpha 1
-----------------------------

'Release date: 2024-10-15'

* Menu:

* macOS: macOS<7>.
* Windows: Windows<13>.
* Tools/Demos: Tools/Demos<15>.
* Tests: Tests<13>.
* Security: Security<16>.
* Library: Library<45>.
* IDLE: IDLE<7>.
* Documentation: Documentation<13>.
* Core and Builtins: Core and Builtins<40>.
* Library: Library<46>.
* Core and Builtins: Core and Builtins<41>.
* Library: Library<47>.
* Core and Builtins: Core and Builtins<42>.
* Library: Library<48>.
* Core and Builtins: Core and Builtins<43>.
* Library: Library<49>.
* Core and Builtins: Core and Builtins<44>.
* Library: Library<50>.
* Core and Builtins: Core and Builtins<45>.
* Library: Library<51>.
* Core and Builtins: Core and Builtins<46>.
* Library: Library<52>.
* Core and Builtins: Core and Builtins<47>.
* C API: C API<15>.
* Build: Build<15>.


File: python.info,  Node: macOS<7>,  Next: Windows<13>,  Up: Python 3 14 0 alpha 1

1.24.18.1 macOS
...............

   - gh-124448(1): Update bundled Tcl/Tk in macOS installer to 8.6.15.

   - gh-123797(2): Check for runtime availability of ‘ptsname_r’
     function on macos.

   - gh-123418(3): Updated macOS installer build to use OpenSSL 3.0.15.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/124448

   (2) https://github.com/python/cpython/issues/123797

   (3) https://github.com/python/cpython/issues/123418


File: python.info,  Node: Windows<13>,  Next: Tools/Demos<15>,  Prev: macOS<7>,  Up: Python 3 14 0 alpha 1

1.24.18.2 Windows
.................

   - gh-124487(1): Increases Windows required OS and API level to
     Windows 10.

   - gh-124609(2): Fix ‘_Py_ThreadId’ for Windows builds using MinGW.
     Patch by Tony Roberts.

   - gh-124448(3): Updated bundled Tcl/Tk to 8.6.15.

   - gh-124254(4): Ensures experimental free-threaded binaries remain
     installed when updating.

   - gh-123915(5): Ensure that ‘Tools\msi\buildrelease.bat’ uses
     different directories for AMD64 and ARM64 builds.

   - gh-123418(6): Updated Windows build to use OpenSSL 3.0.15.

   - gh-123476(7): Add support for ‘socket.TCP_QUICKACK’ on Windows
     platforms.

   - gh-122573(8): The Windows build of CPython now requires 3.10 or
     newer.

   - gh-100256(9): *note mimetypes: 93. no longer fails when it
     encounters an inaccessible registry key.

   - gh-119679(10): Ensures correct import libraries are included in
     Windows installs.

   - gh-119690(11): Adds Unicode support and fixes audit events for
     ‘_winapi.CreateNamedPipe’.

   - gh-111201(12): Add support for new pyrepl on Windows

   - gh-119070(13): Fixes ‘py.exe’ handling of shebangs like
     ‘/usr/bin/env python3.12’, which were previously interpreted as
     ‘python3.exe’ instead of ‘python3.12.exe’.

   - gh-117505(14): Fixes an issue with the Windows installer not
     running ensurepip in a fully isolated environment.  This could
     cause unexpected interactions with the user site-packages.

   - gh-118209(15): Avoid crashing in *note mmap: 94. on Windows when
     the mapped memory is inaccessible due to file system errors or
     access violations.

   - gh-79846(16): Makes ‘ssl.create_default_context()’ ignore invalid
     certificates in the Windows certificate store

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/124487

   (2) https://github.com/python/cpython/issues/124609

   (3) https://github.com/python/cpython/issues/124448

   (4) https://github.com/python/cpython/issues/124254

   (5) https://github.com/python/cpython/issues/123915

   (6) https://github.com/python/cpython/issues/123418

   (7) https://github.com/python/cpython/issues/123476

   (8) https://github.com/python/cpython/issues/122573

   (9) https://github.com/python/cpython/issues/100256

   (10) https://github.com/python/cpython/issues/119679

   (11) https://github.com/python/cpython/issues/119690

   (12) https://github.com/python/cpython/issues/111201

   (13) https://github.com/python/cpython/issues/119070

   (14) https://github.com/python/cpython/issues/117505

   (15) https://github.com/python/cpython/issues/118209

   (16) https://github.com/python/cpython/issues/79846


File: python.info,  Node: Tools/Demos<15>,  Next: Tests<13>,  Prev: Windows<13>,  Up: Python 3 14 0 alpha 1

1.24.18.3 Tools/Demos
.....................

   - gh-123418(1): Update GitHub CI workflows to use OpenSSL 3.0.15 and
     multissltests to use 3.0.15, 3.1.7, and 3.2.3.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/123418


File: python.info,  Node: Tests<13>,  Next: Security<16>,  Prev: Tools/Demos<15>,  Up: Python 3 14 0 alpha 1

1.24.18.4 Tests
...............

   - gh-125041(1): Re-enable skipped tests for *note zlib: 139. on the
     s390x architecture: only skip checks of the compressed bytes, which
     can be different between zlib’s software implementation and the
     hardware-accelerated implementation.

   - gh-124378(2): Updated ‘test_ttk’ to pass with Tcl/Tk 8.6.15.

   - gh-124213(3): Detect whether the test suite is running inside a
     systemd-nspawn container with ‘--suppress-sync=true’ option, and
     skip the ‘test_os’ and ‘test_mmap’ tests that are failing in this
     scenario.

   - gh-124190(4): Add capability to ignore entire files or directories
     in check warning CI tool

   - gh-121921(5): Update ‘Lib/test/crashers/bogus_code_obj.py’ so that
     it crashes properly again.

   - gh-112301(6): Add tooling to check for changes in compiler
     warnings.  Patch by Nate Ohlson.

   - gh-59022(7): Add tests for *note pkgutil.extend_path(): 190c.
     Patch by Andreas Stocker.

   - gh-99242(8): *note os.getloadavg(): 190d. may throw *note OSError:
     2c0. when running regression tests under certain conditions (e.g.
     chroot).  This error is now caught and ignored, since reporting
     load average is optional.

   - gh-121084(9): Fix test_typing random leaks.  Clear typing ABC
     caches when running tests for refleaks (‘-R’ option): call
     ‘_abc_caches_clear()’ on typing abstract classes and their
     subclasses.  Patch by Victor Stinner.

   - gh-121160(10): Add a test for *note readline.set_history_length():
     190e.  Note that this test may fail on readline libraries.

   - gh-121200(11): Fix ‘test_expanduser_pwd2()’ of ‘test_posixpath’.
     Call ‘getpwnam()’ to get ‘pw_dir’, since it can be different than
     ‘getpwall()’ ‘pw_dir’.  Patch by Victor Stinner.

   - gh-121188(12): When creating the JUnit XML file, regrtest now
     escapes characters which are invalid in XML, such as the chr(27)
     control character used in ANSI escape sequences.  Patch by Victor
     Stinner.

   - gh-120801(13): Cleaned up fixtures for importlib.metadata tests and
     consolidated behavior with “test.support.os_helper”.

   - gh-119727(14): Add ‘--single-process’ command line option to Python
     test runner (regrtest).  Patch by Victor Stinner.

   - gh-119273(15): Python test runner no longer runs tests using TTY
     (ex: test_ioctl) in a process group (using ‘setsid()’).
     Previously, tests using TTY were skipped.  Patch by Victor Stinner.

   - gh-119050(16): regrtest test runner: Add XML support to the refleak
     checker (-R option).  Patch by Victor Stinner.

   - gh-101525(17): Skip ‘test_gdb’ if the binary is relocated by BOLT.
     Patch by Donghee Na.

   - gh-107562(18): Test certificates have been updated to expire far in
     the future.  This allows testing Y2038 with system time set to
     after that, so that actual Y2038 issues can be exposed, and not
     masked by expired certificate errors.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/125041

   (2) https://github.com/python/cpython/issues/124378

   (3) https://github.com/python/cpython/issues/124213

   (4) https://github.com/python/cpython/issues/124190

   (5) https://github.com/python/cpython/issues/121921

   (6) https://github.com/python/cpython/issues/112301

   (7) https://github.com/python/cpython/issues/59022

   (8) https://github.com/python/cpython/issues/99242

   (9) https://github.com/python/cpython/issues/121084

   (10) https://github.com/python/cpython/issues/121160

   (11) https://github.com/python/cpython/issues/121200

   (12) https://github.com/python/cpython/issues/121188

   (13) https://github.com/python/cpython/issues/120801

   (14) https://github.com/python/cpython/issues/119727

   (15) https://github.com/python/cpython/issues/119273

   (16) https://github.com/python/cpython/issues/119050

   (17) https://github.com/python/cpython/issues/101525

   (18) https://github.com/python/cpython/issues/107562


File: python.info,  Node: Security<16>,  Next: Library<45>,  Prev: Tests<13>,  Up: Python 3 14 0 alpha 1

1.24.18.5 Security
..................

   - gh-125140(1): Remove the current directory from ‘sys.path’ when
     using PyREPL.

   - gh-123678(2): Upgrade libexpat to 2.6.3

   - gh-112301(3): Enable compiler options that warn of potential
     security vulnerabilities.

   - gh-122792(4): Changed IPv4-mapped ‘ipaddress.IPv6Address’ to
     consistently use the mapped IPv4 address value for deciding
     properties.  Properties which have their behavior fixed are
     ‘is_multicast’, ‘is_reserved’, ‘is_link_local’, ‘is_global’, and
     ‘is_unspecified’.

   - gh-112301(5): Add ability to ignore warnings per file with warning
     count in warning checking tooling.  Patch by Nate Ohlson.

   - gh-112301(6): Add macOS warning tracking to warning check tooling.
     Patch by Nate Ohlson.

   - gh-122133(7): Authenticate the socket connection for the
     ‘socket.socketpair()’ fallback on platforms where ‘AF_UNIX’ is not
     available like Windows.

     Patch by Gregory P. Smith <<greg@krypto.org>> and Seth Larson
     <<seth@python.org>>.  Reported by Ellie <<el@horse64.org>>

   - gh-121957(8): Fixed missing audit events around interactive use of
     Python, now also properly firing for ‘python -i’, as well as for
     ‘python -m asyncio’.  The events in question are
     ‘cpython.run_stdin’ and ‘cpython.run_startup’.

   - gh-112301(9): Enable runtime protections for glibc to abort
     execution when unsafe behavior is encountered, for all platforms
     except Windows.

   - gh-121285(10): Remove backtracking from tarfile header parsing for
     ‘hdrcharset’, PAX, and GNU sparse headers.

   - gh-112301(11): Add default compiler options to improve security.
     Enable -Wimplicit-fallthrough, -fstack-protector-strong,
     -Wtrampolines.

   - gh-118773(12): Fixes creation of ACLs in *note os.mkdir(): 52c. on
     Windows to work correctly on non-English machines.

   - gh-118486(13): *note os.mkdir(): 52c. on Windows now accepts 'mode'
     of ‘0o700’ to restrict the new directory to the current user.  This
     fixes CVE 2024-4030(14) affecting *note tempfile.mkdtemp(): 52e. in
     scenarios where the base temporary directory is more permissive
     than the default.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/125140

   (2) https://github.com/python/cpython/issues/123678

   (3) https://github.com/python/cpython/issues/112301

   (4) https://github.com/python/cpython/issues/122792

   (5) https://github.com/python/cpython/issues/112301

   (6) https://github.com/python/cpython/issues/112301

   (7) https://github.com/python/cpython/issues/122133

   (8) https://github.com/python/cpython/issues/121957

   (9) https://github.com/python/cpython/issues/112301

   (10) https://github.com/python/cpython/issues/121285

   (11) https://github.com/python/cpython/issues/112301

   (12) https://github.com/python/cpython/issues/118773

   (13) https://github.com/python/cpython/issues/118486

   (14) https://www.cve.org/CVERecord?id=CVE-2024-4030


File: python.info,  Node: Library<45>,  Next: IDLE<7>,  Prev: Security<16>,  Up: Python 3 14 0 alpha 1

1.24.18.6 Library
.................

   - gh-125422(1): Fixed the bug where *note pdb: aa. and *note bdb: 10.
     can step into the bottom caller frame.

   - gh-100141(2): Fixed the bug where *note pdb: aa. will be stuck in
     an infinite loop when debugging an empty file.

   - gh-53203(3): Fix *note time.strptime(): 1634. for ‘%c’, ‘%x’ and
     ‘%X’ formats in many locales that use non-ASCII digits, like
     Persian, Burmese, Odia and Shan.

   - gh-125206(4): Workaround for old libffi versions is added.  Module
     ctypes supports double complex only with libffi >= 3.3.0.  Patch by
     Mikhail Efimov.

   - gh-89967(5): Make *note WeakKeyDictionary: 1911. and *note
     WeakValueDictionary: 1912. safe against concurrent mutations from
     other threads.  Patch by Kumar Aditya.

   - gh-125260(6): The *note gzip.compress(): 84f. 'mtime' parameter now
     defaults to 0 for reproducible output.  Patch by Bernhard M.
     Wiedemann and Adam Turner.

   - gh-125243(7): Fix data race when creating *note zoneinfo.ZoneInfo:
     ade. objects in the free threading build.

   - gh-125254(8): Fix a bug where ArgumentError includes the incorrect
     ambiguous option in *note argparse: 7.

   - gh-125235(9): Keep *note tkinter: f6. TCL paths in venv pointing to
     base installation on Windows.

   - gh-61011(10): Fix inheritance of nested mutually exclusive groups
     from parent parser in *note argparse.ArgumentParser: 1bd.
     Previously, all nested mutually exclusive groups lost their
     connection to the group containing them and were displayed as
     belonging directly to the parser.

   - gh-125118(11): Don’t copy arbitrary values to _Bool in the *note
     struct: db. module.

   - gh-125069(12): Fix an issue where providing a *note
     pathlib.PurePath: 6ce. object as an initializer argument to a
     second *note PurePath: 6ce. object with a different *note parser:
     537. resulted in arguments to the former object’s initializer being
     joined by the latter object’s parser.

   - gh-125096(13): If the *note PYTHON_BASIC_REPL: 1b6. environment
     variable is set, the *note site: cc. module no longer imports the
     ‘_pyrepl’ module.  Moreover, the *note site: cc. module now
     respects *note -E: b58. and *note -I: b59. command line options:
     ignore *note PYTHON_BASIC_REPL: 1b6. in this case.  Patch by Victor
     Stinner.

   - gh-124969(14): Fix ‘locale.nl_langinfo(locale.ALT_DIGITS)’.  Now it
     returns a tuple of up to 100 strings (an empty tuple on most
     locales).  Previously it returned the first item of that tuple or
     an empty string.

   - gh-124960(15): Fix support for the ‘barry_as_FLUFL’ future flag in
     the new REPL.

   - gh-69998(16): Fix *note locale.nl_langinfo(): 454. in case when
     different categories have different locales.  The function now sets
     temporarily the ‘LC_CTYPE’ locale in some cases.  This temporary
     change affects other threads.

   - gh-124958(17): Fix refcycles in exceptions raised from *note
     asyncio.TaskGroup: 4d2. and the python implementation of *note
     asyncio.Future: dc8.

   - gh-53203(18): Fix *note time.strptime(): 1634. for ‘%c’ and ‘%x’
     formats in many locales: Arabic, Bislama, Breton, Bodo, Kashubian,
     Chuvash, Estonian, French, Irish, Ge’ez, Gurajati, Manx Gaelic,
     Hebrew, Hindi, Chhattisgarhi, Haitian Kreyol, Japanese, Kannada,
     Korean, Marathi, Malay, Norwegian, Nynorsk, Punjabi, Rajasthani,
     Tok Pisin, Yoruba, Yue Chinese, Yau/Nungon and Chinese.

   - gh-123961(19): Convert *note curses: 2f. to multi-phase
     initialization ( PEP 489(20)), thereby fixing reference leaks at
     interpreter shutdown.  Patch by Bénédikt Tran.

   - gh-124944(21): Add ‘SO_ORIGINAL_DST’ to the *note socket: d1.
     module.

   - gh-117151(22): The default buffer size used by *note
     shutil.copyfileobj(): c54. has been increased from 64k to 256k on
     non-Windows platforms.  It was already larger on Windows.

   - gh-90102(23): Skip the ‘isatty’ system call during open() when the
     file is known to not be a character device.  This provides a slight
     performance improvement when reading whole files.

   - gh-124917(24): Allow calling *note os.path.exists(): c05. and *note
     os.path.lexists(): c06. with keyword arguments on Windows.  Fixes a
     regression in 3.13.0.

   - gh-65865(25): *note argparse: 7. now raises early error for invalid
     ‘help’ arguments to *note add_argument(): 4bd, *note
     add_subparsers(): e13. and ‘add_parser()’.

   - gh-124653(26): Fix detection of the minimal Queue API needed by the
     *note logging: 8b. module.  Patch by Bénédikt Tran.

   - gh-91818(27): The CLI of many modules (*note ast: 9, *note
     ensurepip: 59, *note json: 86, *note pdb: aa, *note sqlite3: d4,
     *note tokenize: 101, *note venv: 117.) now uses the actual
     executable name instead of simply «python» to display in the usage
     message.

   - gh-124858(28): Fix reference cycles left in tracebacks in *note
     asyncio.open_connection(): d10. when used with
     ‘happy_eyeballs_delay’

   - gh-124390(29): Fixed *note AssertionError: 8b9. when using
     ‘asyncio.staggered.staggered_race()’ with *note
     asyncio.eager_task_factory: 6a3.

   - gh-85935(30): *note argparse.ArgumentParser.add_argument(): 4bd.
     now raises an exception if an *note action: 1913. that does not
     consume arguments (like “store_const” or “store_true”) or explicit
     ‘nargs=0’ are specified for positional arguments.

   - gh-124835(31): Make *note tomllib.loads(): 1914. raise *note
     TypeError: 198. not *note AttributeError: 5f0. on bad input types
     that do not have the ‘replace’ attribute.  Improve error message
     when *note bytes: 192. is received.

   - gh-124693(32): Fix a bug where *note argparse: 7. doesn’t recognize
     negative complex numbers or negative numbers using scientific
     notation.

   - gh-124787(33): Fix *note typing.TypeAliasType: 2ae. with incorrect
     ‘type_params’ argument.  Now it raises a *note TypeError: 198. when
     a type parameter without a default follows one with a default, and
     when an entry in the ‘type_params’ tuple is not a type parameter
     object.

   - gh-66436(34): Improved *note prog: 1bc. default value for *note
     argparse.ArgumentParser: 1bd.  It will now include the name of the
     Python executable along with the module or package name, or the
     path to a directory, ZIP file, or directory within a ZIP file if
     the code was run that way.

   - gh-116850(35): Fix *note argparse: 7. for namespaces with not
     directly writable dict (e.g.  classes).

   - gh-101552(36): Add an 'annoation_format' parameter to *note
     inspect.signature(): 22f.  Add an 'quote_annotation_strings'
     parameter to *note inspect.Signature.format(): 231.  Use the new
     functionality to improve the display of annotations in signatures
     in *note pydoc: ba.  Patch by Jelle Zijlstra.

   - gh-58573(37): Fix conflicts between abbreviated long options in the
     parent parser and subparsers in *note argparse: 7.

   - gh-124594(38): All *note asyncio: b. REPL prompts run in the same
     *note context: 177.  Contributed by Bartosz Sławecki.

   - gh-61181(39): Fix support of *note choices: 1915. with string value
     in *note argparse: 7.  Substrings of the specified string no longer
     considered valid values.

   - gh-116750(40): Provide *note sys.monitoring.clear_tool_id(): 1916.
     to unregister all events and callbacks set by the tool.

   - gh-124552(41): Improve the accuracy of *note bdb: 10.’s check for
     the possibility of breakpoint in a frame.  This makes it possible
     to disable unnecessary events in functions.

   - gh-124538(42): Fixed crash when using *note gc.get_referents():
     a08. on a capsule object.

   - gh-80259(43): Fix *note argparse: 7. support of positional
     arguments with ‘nargs='?'’, ‘default=argparse.SUPPRESS’ and
     specified ‘type’.

   - gh-120378(44): Fix a crash related to an integer overflow in *note
     curses.resizeterm(): 1917. and *note curses.resize_term(): 1918.

   - gh-124498(45): Fix *note typing.TypeAliasType: 2ae. not to be
     generic, when ‘type_params’ is an empty tuple.

   - gh-53834(46): Fix support of arguments with *note choices: 1915. in
     *note argparse: 7.  Positional arguments with *note nargs: 1919.
     equal to ‘'?'’ or ‘'*'’ no longer check *note default: 191a.
     against ‘choices’.  Optional arguments with ‘nargs’ equal to ‘'?'’
     no longer check *note const: 191b. against ‘choices’.

   - gh-123884(47): Fixed bug in itertools.tee() handling of other tee
     inputs (a tee in a tee).  The output now has the promised 'n'
     independent new iterators.  Formerly, the first iterator was
     identical (not independent) to the input iterator.  This would
     sometimes give surprising results.

   - gh-123017(48): Due to unreliable results on some devices, *note
     time.strftime(): 13f1. no longer accepts negative years on Android.

   - gh-123014(49): *note os.pidfd_open(): 6a5. and *note
     signal.pidfd_send_signal(): b27. are now unavailable when building
     against Android API levels older than 31, since the underlying
     system calls may cause a crash.

   - gh-124176(50): Add support for *note dataclasses.dataclass(): 4e2.
     in *note unittest.mock.create_autospec(): 191c.  Now
     ‘create_autospec’ will check for potential dataclasses and use
     *note dataclasses.fields(): 191d. function to retrieve the spec
     information.

   - gh-124345(51): *note argparse: 7. supports abbreviated single-dash
     long options separated by ‘=’ from its value.

   - gh-124400(52): Fixed a *note pdb: aa. bug where ‘until’ has no
     effect when it appears in a ‘commands’ sequence.  Also avoid
     printing the frame information at a breakpoint that has a command
     list containing a command that resumes execution.

   - gh-90562(53): Modify dataclasses to support zero-argument super()
     when ‘slots=True’ is specified.  This works by modifying all
     references to ‘__class__’ to point to the newly created class.

   - gh-104860(54): Fix disallowing abbreviation of single-dash long
     options in *note argparse: 7. with ‘allow_abbrev=False’.

   - gh-63143(55): Fix parsing mutually exclusive arguments in *note
     argparse: 7.  Arguments with the value identical to the default
     value (e.g.  booleans, small integers, empty or 1-character
     strings) are no longer considered «not present».

   - gh-72795(56): Positional arguments with *note nargs: 1919. equal to
     ‘'*'’ or ‘argparse.REMAINDER’ are no longer required.  This allows
     to use positional argument with ‘nargs='*'’ and without ‘default’
     in mutually exclusive group and improves error message about
     required arguments.

   - gh-59317(57): Fix parsing positional argument with *note nargs:
     1919. equal to ‘'?'’ or ‘'*'’ if it is preceded by an option and
     another positional argument.

   - gh-100980(58): The *note _fields_: 191e. attribute of *note
     ctypes.Structure: 1e5. and *note Union: 1e6. is no longer set if
     the setattr operation raises an error.

   - gh-53780(59): *note argparse: 7. now ignores the first ‘"--"’
     (double dash) between an option and command.

   - gh-124217(60): Add RFC 9637 reserved IPv6 block ‘3fff::/20’ in
     *note ipaddress: 84. module.

   - gh-111513(61): Improve the error message that may be raised by
     *note datetime.date.fromtimestamp(): dcf.

   - gh-124248(62): Fixed potential crash when using *note struct: db.
     to process zero-width “Pascal string” fields (‘0p’).

   - gh-81691(63): Fix handling of multiple ‘"--"’ (double dashes) in
     *note argparse: 7.  Only the first one has now been removed, all
     subsequent ones are now taken literally.

   - gh-87041(64): Fix a bug in *note argparse: 7. where lengthy
     subparser argument help is incorrectly indented.

   - gh-84559(65): The default *note multiprocessing: 98. start method
     on Linux and other POSIX systems has been changed away from often
     unsafe ‘"fork"’ to ‘"forkserver"’ (when the platform supports
     sending file handles over pipes as most do) or ‘"spawn"’.  Mac and
     Windows are unchanged as they already default to ‘"spawn"’.

   - gh-124212(66): Fix invalid variable in *note venv: 117. handling of
     failed symlink on Windows

   - gh-124171(67): Add workaround for broken ‘fmod()’ implementations
     on Windows, that loose zero sign (e.g.  ‘fmod(-10, 1)’ returns
     ‘0.0’).  Patch by Sergey B Kirpichev.

   - gh-123978(68): Remove broken *note time.thread_time(): b32. and
     *note time.thread_time_ns(): d8c. on NetBSD.

   - gh-123934(69): Fix *note unittest.mock.MagicMock: 1091. resetting
     magic methods return values after ‘.reset_mock(return_value=True)’
     was called.

   - gh-124016(70): Update *note unicodedata: 10b. database to Unicode
     16.0.0.

   - gh-123968(71): Fix the command-line interface for the *note random:
     bd. module to select floats between 0 and N, not 1 and N.

   - gh-123945(72): Fix a bug where *note argparse: 7. doesn’t recognize
     negative numbers with underscores

   - gh-123935(73): Fix parent slots detection for dataclasses that
     inherit from classes with ‘__dictoffset__’.

   - gh-123892(74): Add ‘"_wmi"’ to *note sys.stdlib_module_names: a44.
     Patch by Victor Stinner.

   - gh-84808(75): Fix error handling in *note socket: fa3. method *note
     connect_ex(): 1740. on platforms where ‘errno’ can be negative.

   - gh-123756(76): Added a new argument ‘mode’ to *note pdb.Pdb: 273.
     Only allow *note pdb: aa. from command line to use ‘restart’
     command.

   - gh-122765(77): Fix unbalanced quote errors occurring when
     activate.csh in *note venv: 117. was sourced with a custom prompt
     containing unpaired quotes or newlines.

   - gh-123657(78): Fix crash and memory leak in *note
     decimal.getcontext(): 191f.  It crashed when using a thread-local
     context by ‘--with-decimal-contextvar=no’.

   - gh-123339(79): Fix *note inspect.getsource(): 17ab. for classes in
     *note collections.abc: 1f. and *note decimal: 3a. (for pure Python
     implementation) modules.  *note inspect.getcomments(): 1920. now
     raises OSError instead of IndexError if the ‘__firstlineno__’ value
     for a class is out of bound.

   - gh-123374(80): Remove check for redefined memo entry in *note
     pickletools.dis(): ec0.

   - gh-123504(81): Fixed reference leak in the finalization of *note
     tkinter: f6.

   - gh-123430(82): Pages generated by the *note http.server: 76. module
     allow the browser to apply its default dark mode.

   - gh-123446(83): Fix empty function name in *note TypeError: 198.
     when *note csv.reader(): 6af, *note csv.writer(): 6b0, or *note
     csv.register_dialect(): 1921. are used without the required args.

   - gh-123448(84): Fixed memory leak of *note typing.NoDefault: 569. by
     moving it to the static types array.

   - gh-123409(85): Fix *note ipaddress.IPv6Address.reverse_pointer:
     1922. output according to RFC 3596, §2.5(86).  Patch by Bénédikt
     Tran.

   - gh-123089(87): Make *note weakref.WeakSet: 7f6. safe against
     concurrent mutations while it is being iterated.  Patch by Kumar
     Aditya.

   - gh-123363(88): Show string value of *note CONTAINS_OP: 1923. oparg
     in *note dis: 3c. output.  Patch by Alexandr153.

   - gh-123341(89): Add *note __class_getitem__(): 944. to
     ‘tkinter.Event’ for type subscript support at runtime.  Patch by
     Adonis Rakateli.

   - gh-123340(90): Show string value of *note IS_OP: 1924. oparg in
     *note dis: 3c. output.

   - gh-119518(91): Speed up normalization of *note pathlib.PurePath:
     6ce. and *note Path: 266. objects by not interning string parts.

   - gh-123270(92): Applied a more surgical fix for malformed payloads
     in *note zipfile.Path: 8d9. causing infinite loops (gh-122905(93))
     without breaking contents using legitimate characters.

   - gh-73991(94): Add *note pathlib.Path.copy_into(): 268. and *note
     move_into(): 26a, which copy and move files and directories into
     'existing' directories.

   - gh-123228(95): Fix return type for
     ‘_pyrepl.readline._ReadlineWrapper.get_line_buffer()’ to be *note
     str(): 169.  Patch by Sergey B Kirpichev.

   - gh-123240(96): Raise audit events for the *note input(): 14e0. in
     the new REPL.

   - gh-76960(97): Fix *note urllib.parse.urljoin(): 1098. and *note
     urllib.parse.urldefrag(): 144f. for URIs containing empty
     components.  For example, ‘urljoin()’ with relative reference «?»
     now sets empty query and removes fragment.  Preserve empty
     components (authority, params, query, fragment) in ‘urljoin()’.
     Preserve empty components (authority, params, query) in
     ‘urldefrag()’.

   - gh-116810(98): Resolve a memory leak introduced in CPython 3.10’s
     *note ssl: d5. when the *note ssl.SSLSocket.session: 1925. property
     was accessed.  Speeds up read and write access to said property by
     no longer unnecessarily cloning session objects via serialization.

   - gh-123243(99): Fix memory leak in ‘_decimal’.

   - gh-122546(100): Consistently use same file name for different
     exceptions in the new repl.  Patch by Sergey B Kirpichev.

   - gh-123213(101): *note xml.etree.ElementTree.Element.extend(): 13db.
     and *note Element: 363. assignment no longer hide the internal
     exception if an erroneous generator is passed.  Patch by Bar Harel.

   - gh-85110(102): Preserve relative path in URL without netloc in
     *note urllib.parse.urlunsplit(): 1926. and *note
     urllib.parse.urlunparse(): 1927.

   - gh-123165(103): Add support for rendering *note Positions: 1928. in
     *note dis: 3c.

   - gh-122909(104): In urllib.request when URLError is raised opening
     an ftp URL, the exception argument is now consistently a string.
     Earlier versions passed either a string or an ftplib exception
     instance as the argument to URLError.

   - gh-123084(105): Deprecate ‘shutil.ExecError’, which hasn’t been
     raised by any *note shutil: ca. function since Python 3.4.  It’s
     now an alias for *note RuntimeError: 244.

   - gh-123085(106): In a bare call to *note
     importlib.resources.files(): 6b7, ensure the caller’s frame is
     properly detected when ‘importlib.resources’ is itself available as
     a compiled module only (no source).

   - gh-123067(107): Fix quadratic complexity in parsing ‘"’-quoted
     cookie values with backslashes by *note http.cookies: 75.

   - gh-123049(108): Add support for *note UNNAMED_SECTION: 1772. in
     *note configparser.ConfigParser.add_section(): 1475.

   - gh-121735(109): When working with zip archives, importlib.resources
     now properly honors module-adjacent references (e.g.
     ‘files(pkg.mod)’ and not just ‘files(pkg)’).

   - gh-122981(110): Fix *note inspect.getsource(): 17ab. for generated
     classes with Python base classes (e.g.  enums).

   - gh-122903(111): ‘zipfile.Path.glob’ now correctly matches
     directories instead of silently omitting them.

   - gh-122905(112): *note zipfile.Path: 8d9. objects now sanitize names
     from the zipfile.

   - gh-122873(113): Enable *note json: 86. module to work as a script
     using the *note -m: 23c. switch: ‘python -m json’.  See the *note
     JSON command-line interface: 23e. documentation.  Patch by Trey
     Hunner.

   - gh-122858(114): Deprecate ‘asyncio.iscoroutinefunction()’ in favor
     of *note inspect.iscoroutinefunction(): 30d.

   - gh-116263(115): *note logging.handlers.RotatingFileHandler: 1929.
     no longer rolls over empty log files.

   - gh-105376(116): Restore the deprecated *note logging: 8b. ‘warn()’
     method.  It was removed in Python 3.13 alpha 1.  Keep the
     deprecated ‘warn()’ method in Python 3.13.  Patch by Victor
     Stinner.

   - gh-122311(117): Improve errors in the *note pickle: ab. module.
     *note PicklingError: 192a. is now raised more often instead of
     *note UnicodeEncodeError: 888, *note ValueError: 2ec. and *note
     AttributeError: 5f0, and the original exception is chained to it.
     Improve and unify error messages in Python and C implementations.

   - gh-122744(118): Bump the version of pip bundled in ensurepip to
     version 24.2.

   - gh-118761(119): Improve import time of *note pprint: b3. by around
     seven times.  Patch by Hugo van Kemenade.

   - gh-118974(120): Add ‘decorator’ parameter to *note
     dataclasses.make_dataclass(): 1844. to customize the functional
     creation of dataclasses.

   - gh-118814(121): Fix the *note typing.TypeVar: 487. constructor when
     name is passed by keyword.

   - gh-122637(122): Adjust ‘cmath.tanh(nanj)’ and ‘cmath.tanh(infj)’
     for recent C standards.

   - gh-122478(123): Remove internal frames from tracebacks shown in
     *note code.InteractiveInterpreter: 192b. with non-default *note
     sys.excepthook(): a0e.  Save correct tracebacks in *note
     sys.last_traceback: 6e9. and update ‘__traceback__’ attribute of
     *note sys.last_value: 6e8. and *note sys.last_exc: 6e6.

   - gh-116622(124): On Android, the ‘FICLONE’ and ‘FICLONERANGE’
     constants are no longer exposed by *note fcntl: 5d, as these ioctls
     are blocked by SELinux.

   - gh-82378(125): Make sure that the new *note REPL: 492. interprets
     *note sys.tracebacklimit: 192c. in the same way that the classic
     REPL did.

   - gh-122334(126): Fix crash when importing *note ssl: d5. after the
     main interpreter restarts.

   - gh-122459(127): Optimize *note pickling: ab. by name objects
     without the ‘__module__’ attribute.

   - gh-87320(128): In *note code.InteractiveInterpreter: 192b, handle
     exceptions caused by calling a non-default *note sys.excepthook():
     a0e.  Before, the exception bubbled up to the caller, ending the
     *note REPL: 492.

   - gh-122272(129): On some platforms such as Linux, year with century
     was not 0-padded when formatted by *note strftime(): e90. with
     C99-specific specifiers ‘'%C'’ or ‘'%F'’.  The 0-padding behavior
     is now guaranteed when the format specifiers ‘'%C'’ and ‘'%F'’ are
     supported by the C library.  Patch by Ben Hsing

   - gh-122400(130): Handle *note ValueError: 2ec.s raised by *note
     os.stat(): 26d. in *note filecmp.dircmp: 1142. and *note
     filecmp.cmpfiles(): 192d.  Patch by Bénédikt Tran.

   - gh-122311(131): Fix some error messages in *note pickle: ab.

   - gh-121650(132): *note email: 3f. headers with embedded newlines are
     now quoted on output.  The *note generator: 44. will now refuse to
     serialize (write) headers that are unsafely folded or delimited;
     see *note verify_generated_headers: 4f3.  (Contributed by Bas
     Bloemsaat and Petr Viktorin in gh-121650(133).)

   - gh-122332(134): Fixed segfault with *note asyncio.Task.get_coro():
     bd1. when using an eager task factory.

   - gh-105733(135): *note ctypes.ARRAY(): 59e. is now *note soft
     deprecated: 23d.: it no longer emits deprecation warnings and is
     not scheduled for removal.

   - gh-122213(136): Add notes for pickle serialization errors that
     allow to identify the source of the error.

   - gh-119180(137): As part of PEP 749(138), add the following
     attributes for customizing evaluation of annotation scopes:

        * ‘evaluate_value’ on *note typing.TypeAliasType: 2ae.

        * ‘evaluate_bound’, ‘evaluate_constraints’, and
          ‘evaluate_default’ on *note typing.TypeVar: 487.

        * ‘evaluate_default’ on *note typing.ParamSpec: 488.

        * ‘evaluate_default’ on *note typing.TypeVarTuple: 489.

   - gh-119180(139): Fix handling of classes with custom metaclasses in
     ‘annotationlib.get_annotations’.

   - gh-122170(140): Handle *note ValueError: 2ec.s raised by *note
     os.stat(): 26d. in *note linecache: 89.  Patch by Bénédikt Tran.

   - gh-122163(141): Add notes for JSON serialization errors that allow
     to identify the source of the error.

   - gh-122129(142): Improve support of method descriptors and wrappers
     in the help title.

   - gh-122145(143): Fix an issue when reporting tracebacks
     corresponding to Python code emitting an empty AST body.  Patch by
     Nikita Sobolev and Bénédikt Tran.

   - gh-121723(144): Make *note logging.config.dictConfig(): 13b8.
     accept any object implementing the Queue public API. See the *note
     queue configuration: 192e. section for details.  Patch by Bénédikt
     Tran.

   - gh-82951(145): Serializing objects with complex ‘__qualname__’
     (such as unbound methods and nested classes) by name no longer
     involves serializing parent objects by value in pickle protocols <
     4.

   - gh-120754(146): ‘Pathlib.read_bytes’ no longer opens the file in
     Python’s buffered I/O mode.  This reduces overheads as the code
     reads a file in whole leading to a modest speedup.

   - gh-113785(147): *note csv: 2d. now correctly parses numeric fields
     (when used with *note csv.QUOTE_NONNUMERIC: 192f. or *note
     csv.QUOTE_STRINGS: 6ae.) which start with an escape character.

   - gh-122088(148): *note @warnings.deprecated: 48a. now copies the
     coroutine status of functions and methods so that *note
     inspect.iscoroutinefunction(): 30d. returns the correct result.

   - gh-122081(149): Fix a crash in the ‘decimal.IEEEContext()’ optional
     function available via the ‘EXTRA_FUNCTIONALITY’ configuration
     flag.

   - gh-73991(150): Add *note pathlib.Path.move(): 269, which moves a
     file or directory tree.

   - gh-121268(151): Remove workarounds for non-IEEE 754 systems in
     *note cmath: 19.

   - gh-119698(152): Due to the lack of interest for *note
     symtable.Class.get_methods(): 31d, the method is marked as
     deprecated and will be removed in Python 3.16.  Patch by Bénédikt
     Tran.

   - gh-121889(153): Adjusts ‘cmath.acosh(complex('0+nanj'))’ for recent
     C standards.

   - gh-121804(154): Correctly show error locations, when *note
     SyntaxError: 18e. raised in new repl.  Patch by Sergey B Kirpichev.

   - gh-121797(155): Add alternative *note Fraction: 213. constructor
     *note Fraction.from_number(): 214.

   - gh-121798(156): Add alternative *note Decimal: 1fe. constructor
     *note Decimal.from_number(): 1fd.

   - gh-120930(157): Fixed a bug introduced by gh-92081(158) that added
     an incorrect extra blank to encoded words occurring in wrapped
     headers.

   - gh-57141(159): The 'shallow' argument to *note filecmp.dircmp:
     1142. (new in Python 3.13) is now keyword-only.

   - gh-121245(160): Simplify handling of the history file in
     ‘site.register_readline()’ helper.  The ‘CAN_USE_PYREPL’ variable
     now will be initialized, when imported.  Patch by Sergey B
     Kirpichev.

   - gh-121249(161): Support the float complex and double complex C
     types in the *note struct: db. module if the compiler has C11
     complex arithmetic.  Patch by Sergey B Kirpichev.

   - gh-121486(162): *note math: 92. functions *note isqrt(): bfa, *note
     log(): 16c7, *note log2(): 12e3. and *note log10(): 1930. now
     support integers larger than ‘2**2**32’ on 32-bit platforms.

   - gh-121474(163): Fix missing sanity check for ‘parties’ arg in *note
     threading.Barrier: 13eb. constructor.  Patch by Clinton Christian
     (pygeek).

   - gh-121450(164): Hard-coded breakpoints (*note breakpoint(): 271.
     and *note pdb.set_trace(): 272.) now reuse the most recent ‘Pdb’
     instance that calls ‘Pdb.set_trace()’, instead of creating a new
     one each time.  As a result, all the instance specific data like
     ‘display’ and ‘commands’ are preserved across Hard-coded
     breakpoints.

   - gh-119169(165): Slightly speed up *note os.walk(): 6d1. by
     simplifying exception handling.

   - gh-121423(166): Improve import time of *note socket: d1. by lazy
     importing modules and writing ‘socket.errorTab’ as a constant.

   - gh-59110(167): *note zipimport: 138. supports now namespace
     packages when no directory entry exists.

   - gh-119004(168): Fix a crash in *note OrderedDict.__eq__: 1931. when
     operands are mutated during the check.  Patch by Bénédikt Tran.

   - gh-121313(169): Limit the reading size in the *note
     multiprocessing.connection.Connection: 12e8. class to 64 KiB to
     prevent memory overallocation and unnecessary memory management
     system calls.

   - gh-121332(170): Fix constructor of *note ast: 9. nodes with custom
     ‘_attributes’.  Previously, passing custom attributes would raise a
     *note DeprecationWarning: 1a3.  Passing arguments to the
     constructor that are not in ‘_fields’ or ‘_attributes’ remains
     deprecated.  Patch by Jelle Zijlstra.

   - gh-121245(171): Fix a bug in the handling of the command history of
     the new *note REPL: 492. that caused the history file to be wiped
     at REPL exit.

   - gh-121210(172): Handle AST nodes with missing runtime fields or
     attributes in *note ast.compare(): 1bf.  Patch by Bénédikt Tran.

   - gh-121163(173): Add support for ‘all’ as an valid ‘action’ for
     *note warnings.simplefilter(): 8d1. and *note
     warnings.filterwarnings(): 16b0.

   - gh-121151(174): Fix wrapping of long usage text of arguments inside
     a mutually exclusive group in *note argparse: 7.

   - gh-121141(175): Add support for *note copy.replace(): 1c0. to AST
     nodes.  Patch by Bénédikt Tran.

   - gh-87744(176): Fix waitpid race while calling *note send_signal():
     1932. in asyncio.  Patch by Kumar Aditya.

   - gh-121027(177): Add a future warning in
     ‘functools.partial.__get__()’.  In future Python versions *note
     functools.partial: 217. will be a method descriptor.

   - gh-121027(178): Make the *note functools.partial: 217. object a
     method descriptor.

   - gh-117784(179): CPython now detects whether its linked TLS library
     supports TLSv1.3 post-handshake authentication and disables that
     feature if support is lacking.

   - gh-121025(180): Improve the *note __repr__(): 830. of *note
     functools.partialmethod: 218.  Patch by Bénédikt Tran.

   - gh-121018(181): Fixed issues where
     ‘argparse.ArgumentParser.parse_args()’ did not honor
     ‘exit_on_error=False’.  Based on patch by Ben Hsing.

   - gh-119614(182): Fix truncation of strings with embedded null
     characters in some internal operations in *note tkinter: f6.

   - gh-120910(183): When reading installed files from an egg, use
     ‘relative_to(walk_up=True)’ to honor files installed outside of the
     installation root.

   - gh-61103(184): Support float complex, double complex and long
     double complex C types in *note ctypes: 2e. as *note
     c_float_complex: 1ed, *note c_double_complex: 1ee. and *note
     c_longdouble_complex: 1ef. if the compiler has C11 complex
     arithmetic.  Patch by Sergey B Kirpichev.

   - gh-120888(185): Upgrade pip wheel bundled with ensurepip (pip
     24.1.1)

   - gh-101830(186): Accessing the *note tkinter: f6. object’s string
     representation no longer converts the underlying Tcl object to a
     string on Windows.

   - gh-120678(187): Fix regression in the new REPL that meant that
     globals from files passed using the ‘-i’ argument would not be
     included in the REPL’s global namespace.  Patch by Alex Waygood.

   - gh-120811(188): Fix possible memory leak in *note
     contextvars.Context.run(): 1933.

   - gh-120782(189): Fix wrong references of the *note datetime: 34.
     types after reloading the module.

   - gh-120713(190): *note datetime.datetime.strftime(): e90. now 0-pads
     years with less than four digits for the format specifiers ‘%Y’ and
     ‘%G’ on Linux.  Patch by Ben Hsing

   - gh-120769(191): Make empty line in *note pdb: aa. repeats the last
     command even when the command is from ‘cmdqueue’.

   - gh-120780(192): Show string value of LOAD_SPECIAL oparg in *note
     dis: 3c. output.

   - gh-41431(193): Add *note datetime.time.strptime(): 1934. and *note
     datetime.date.strptime(): 1f9.  Contributed by Wannes Boeykens.

   - gh-120743(194): *note Soft deprecate: 23d. *note os.popen(): 31a.
     and *note os.spawn*: 31b. functions.  They should no longer be used
     to write new code.  The *note subprocess: dc. module is recommended
     instead.  Patch by Victor Stinner.

   - gh-120732(195): Fix ‘name’ passing to *note unittest.mock.Mock:
     c41. object when using *note unittest.mock.create_autospec(): 191c.

   - gh-111259(196): *note re: be. now handles patterns like ‘"[\s\S]"’
     or ‘"\s|\S"’ which match any character as effectively as a dot with
     the ‘DOTALL’ modifier (‘"(?s:.)"’).

   - gh-120683(197): Fix an error in *note logging.LogRecord: 11e8, when
     the integer part of the timestamp is rounded up, while the
     millisecond calculation truncates, causing the log timestamp to be
     wrong by up to 999 ms (affected roughly 1 in 8 million timestamps).

   - gh-118710(198): *note ipaddress.IPv4Address: 50d. and *note
     ipaddress.IPv6Address: 50e. attributes ‘version’ and
     ‘max_prefixlen’ are now available on the class.

   - gh-120633(199): Move scrollbar and remove tear-off menus in
     turtledemo.

   - gh-120606(200): Allow users to use EOF to exit ‘commands’
     definition in *note pdb: aa.

   - gh-120284(201): Allow *note asyncio.Runner.run(): 1935. to accept
     *note awaitable: 4ca. objects instead of simply *note coroutine:
     6ba.s.

   - gh-120541(202): Improve the prompt in the «less» pager when *note
     help(): ad6. is called with non-string argument.

   - gh-120495(203): Fix incorrect exception handling in Tab Nanny.
     Patch by Wulian233.

   - gh-120388(204): Improve a warning message when a test method in
     *note unittest: 10c. returns something other than ‘None’.  Now we
     show the returned object type and optional asyncio-related tip.

   - gh-120381(205): Correct *note inspect.ismethoddescriptor(): 1936.
     to check also for the lack of *note __delete__(): 1937.  Patch by
     Jan Kaliszewski.

   - gh-90425(206): The OS byte in gzip headers is now always set to 255
     when using *note gzip.compress(): 84f.

   - gh-120343(207): Fix column offset reporting for tokens that come
     after multiline f-strings in the *note tokenize: 101. module.

   - gh-119180(208): As part of implementing PEP 649(209) and PEP
     749(210), add a new module ‘annotationlib’.  Add support for
     unresolved forward references in annotations to *note dataclasses:
     33, *note typing.TypedDict: 332, and *note typing.NamedTuple: 331.

   - gh-119600(211): Fix *note unittest.mock.patch(): 1094. to not read
     attributes of the target when ‘new_callable’ is set.  Patch by
     Robert Collins.

   - gh-120289(212): Fixed the use-after-free issue in *note cProfile:
     2b. by disallowing ‘disable()’ and ‘clear()’ in external timers.

   - gh-82017(213): Added support for converting any objects that have
     the ‘as_integer_ratio()’ method to a *note Fraction: 213.

   - gh-114053(214): Fix edge-case bug where *note
     typing.get_type_hints(): 8c1. would produce incorrect results if
     type parameters in a class scope were overridden by assignments in
     a class scope and ‘from __future__ import annotations’ semantics
     were enabled.  Patch by Alex Waygood.

   - gh-114053(215): Fix erroneous *note NameError: 452. when calling
     *note inspect.get_annotations(): a16. with ‘eval_str=True`’ on a
     class that made use of PEP 695(216) type parameters in a module
     that had ‘from __future__ import annotations’ at the top of the
     file.  Patch by Alex Waygood.

   - gh-120268(217): Prohibit passing ‘None’ to pure-Python *note
     datetime.date.fromtimestamp(): dcf. to achieve consistency with
     C-extension implementation.

   - gh-120244(218): Fix memory leak in *note re.sub(): 5a3. when the
     replacement string contains backreferences.

   - gh-120254(219): Added ‘commands’ argument to *note pdb.set_trace():
     272. which allows users to send debugger commands from the source
     file.

   - gh-120211(220): Fix *note tkinter.ttk: ff. with Tcl/Tk 9.0.

   - gh-71587(221): Fix crash in C version of *note
     datetime.datetime.strptime(): 1938. when called again on the
     restarted interpreter.

   - gh-117983(222): Defer the ‘threading’ import in ‘importlib.util’
     until lazy loading is used.

   - gh-120157(223): Remove unused constant
     ‘concurrent.futures._base._FUTURE_STATES’ in *note
     concurrent.futures: 24.  Patch by Clinton Christian (pygeek).

   - gh-120161(224): *note datetime: 34. no longer crashes in certain
     complex reference cycle situations.

   - gh-119698(225): Fix *note symtable.Class.get_methods(): 31d. and
     document its behaviour.  Patch by Bénédikt Tran.

   - gh-120121(226): Add *note concurrent.futures.InvalidStateError:
     1939. to module’s ‘__all__’.

   - gh-119933(227): Add the *note symtable.SymbolTableType: 193a.
     enumeration to represent the possible outputs of the *note
     symtable.SymbolTable.get_type: 193b. method.  Patch by Bénédikt
     Tran.

   - gh-120029(228): Expose *note symtable.Symbol: 289. methods *note
     is_free_class(): 28c, *note is_comp_iter(): 28b. and *note
     is_comp_cell(): 28a.  Patch by Bénédikt Tran.

   - gh-120108(229): Fix calling *note copy.deepcopy(): d67. on *note
     ast: 9. trees that have been modified to have references to parent
     nodes.  Patch by Jelle Zijlstra.

   - gh-120056(230): Add ‘socket.IP_RECVERR’ and ‘socket.IP_RECVTTL’
     constants (both available since Linux 2.2).  And
     ‘socket.IP_RECVORIGDSTADDR’ constant (available since Linux
     2.6.29).

   - gh-112672(231): Support building *note tkinter: f6. with Tcl 9.0.

   - gh-120057(232): Added the *note os.environ.refresh(): 259. method
     to update *note os.environ: 259. with changes to the environment
     made by *note os.putenv(): 25b, by *note os.unsetenv(): 25c, or
     made outside Python in the same process.  Patch by Victor Stinner.

   - gh-120029(233): Expose *note symtable.Symbol.is_type_parameter():
     193c. in the *note symtable: de. module.  Patch by Bénédikt Tran.

   - gh-119819(234): Fix regression to allow logging configuration with
     multiprocessing queue types.

   - gh-65454(235): *note unittest.mock.Mock.attach_mock(): 193d. no
     longer triggers a call to a ‘PropertyMock’ being attached.

   - gh-117142(236): The *note ctypes: 2e. module may now be imported in
     all subinterpreters, including those that have their own GIL.

   - gh-118835(237): Fix _pyrepl crash when using custom prompt with
     ANSI escape codes.

   - gh-81936(238): ‘help()’ and ‘showtopic()’ methods now respect a
     configured 'output' argument to ‘pydoc.Helper’ and not use the
     pager in such cases.  Patch by Enrico Tröger.

   - gh-117398(239): The ‘_datetime’ module (C implementation for *note
     datetime: 34.) now supports being imported in multiple
     interpreters.

   - gh-119824(240): Print stack entry in *note pdb: aa. when and only
     when user input is needed.

   - gh-119838(241): In mixed arithmetic operations with *note Fraction:
     213. and complex, the fraction is now converted to *note float:
     196. instead of *note complex: 197.

   - gh-119770(242): Make *note termios: e7. ‘ioctl()’ constants
     positive.  Patch by Victor Stinner.

   - gh-89727(243): Fix issue with *note shutil.rmtree(): 356. where a
     *note RecursionError: f6a. is raised on deep directory trees.

   - gh-119577(244): The *note DeprecationWarning: 1a3. emitted when
     testing the truth value of an *note xml.etree.ElementTree.Element:
     363. now describes unconditionally returning ‘True’ in a future
     version rather than raising an exception in Python 3.14.

   - gh-89727(245): Partially fix issue with *note shutil.rmtree(): 356.
     where a *note RecursionError: f6a. is raised on deep directory
     trees.  A recursion error is no longer raised when
     ‘rmtree.avoids_symlink_attacks’ is false.

   - gh-93963(246): Remove deprecated names from ‘importlib.abc’ as
     found in ‘importlib.resources.abc’.

   - gh-119118(247): Fix performance regression in the *note tokenize:
     101. module by caching the ‘line’ token attribute and calculating
     the column offset more efficiently.

   - gh-89727(248): Fix issue with *note os.fwalk(): d54. where a *note
     RecursionError: f6a. was raised on deep directory trees by
     adjusting the implementation to be iterative instead of recursive.

   - gh-119594(249): If one calls pow(fractions.Fraction, x, module)
     with modulo not None, the error message now says that the types are
     incompatible rather than saying pow only takes 2 arguments.  Patch
     by Wim Jeantine-Glenn and Mark Dickinson.

   - gh-119588(250): ‘zipfile.Path.is_symlink’ now assesses if the given
     path is a symlink.

   - gh-119562(251): Remove ‘ast.Num’, ‘ast.Str’, ‘ast.Bytes’,
     ‘ast.NameConstant’ and ‘ast.Ellipsis’.  They had all emitted
     deprecation warnings since Python 3.12.  Patch by Alex Waygood.

   - gh-119555(252): Catch *note SyntaxError: 18e. from *note compile():
     4b2. in the runsource() method of the InteractiveColoredConsole.
     Patch by Sergey B Kirpichev.

   - gh-118908(253): Limit exposed globals from internal imports and
     definitions on new REPL startup.  Patch by Eugene Triguba and Pablo
     Galindo.

   - gh-117865(254): Improve the import time of the *note ast: 9. module
     by deferring the import of *note re: be.  Patch by Jelle Zijlstra.

   - gh-119127(255): Positional arguments of *note functools.partial():
     217. objects now support placeholders via *note
     functools.Placeholder: 216.

   - gh-113892(256): Now, the method ‘sock_connect’ of *note
     asyncio.ProactorEventLoop: 81e. raises a *note ValueError: 2ec. if
     given socket is not in non-blocking mode, as well as in other loop
     implementations.

   - gh-119506(257): Fix ‘io.TextIOWrapper.write()’ method breaks
     internal buffer when the method is called again during flushing
     internal buffer.

   - gh-69214(258): Fix ‘fcntl.ioctl()’ 'request' parameter: use an
     ‘unsigned long’ instead of an ‘unsigned int’ for the 'request'
     parameter of *note fcntl.ioctl(): 1682. to support requests larger
     than ‘UINT_MAX’.  Patch by Victor Stinner.

   - gh-119105(259): ‘difflib’’s ‘DIffer.compare()’ (and so also
     ‘ndiff’) can no longer be provoked into cubic-time behavior, or
     into unbounded recursion, and should generally be faster in
     ordinary cases too.  Results may change in some cases, although
     that should be rare.  Correctness of diffs is not affected.  Some
     similar lines far apart may be reported as deleting one and adding
     the other, where before they were displayed on adjacent output
     lines with markup showing the intraline differences.

   - gh-119443(260): The interactive REPL no longer runs with ‘from
     __future__ import annotations’ enabled.  Patch by Jelle Zijlstra.

   - gh-119461(261): Add ‘socket.VMADDR_CID_LOCAL’ constant.  Patch by
     Victor Stinner.

   - gh-117398(262): Objects in the datetime C-API are now all
     statically allocated, which means better memory safety, especially
     when the module is reloaded.  This should be transparent to users.

   - gh-118894(263): *note asyncio: b. REPL now has the same
     capabilities as PyREPL.

   - gh-118830(264): Bump *note pickle: ab. default protocol to ‘5’.

   - gh-118911(265): In PyREPL, updated ‘maybe-accept’’s logic so that
     if the user hits ‘Enter’ twice, they are able to terminate the
     block even if there’s trailing whitespace.  Also, now when the user
     hits arrow up, the cursor is on the last functional line.  This
     matches IPython’s behavior.  Patch by Aya Elsayed.

   - gh-115225(266): Raise error on certain technically valid but
     pathological ISO 8601 strings passed to *note
     datetime.time.fromisoformat(): 82a. that were previously parsed
     incorrectly.

   - gh-111201(267): Remove dependency to *note readline: bf. from the
     new Python REPL.

   - gh-119189(268): When using the ‘**’ operator or *note pow(): 1a4.
     with *note Fraction: 213. as the base and an exponent that is not
     rational, a float, or a complex, the fraction is no longer
     converted to a float.

   - gh-119174(269): Fix high DPI causes turtledemo(turtle-graphics
     examples) windows blurry Patch by Wulian233 and Terry Jan Reedy

   - gh-119121(270): Fix a NameError happening in
     ‘asyncio.staggered.staggered_race’.  This function is now tested.

   - gh-119105(271): ‘difflib.Differ’ is much faster for some cases of
     diffs where many pairs of lines are equally similar.

   - gh-119113(272): Fix issue where *note
     pathlib.PurePath.with_suffix(): 193e. didn’t raise *note TypeError:
     198. when given ‘None’ as a suffix.

   - gh-118643(273): Fix an AttributeError in the *note email: 3f.
     module when re-fold a long address list.  Also fix more cases of
     incorrect encoding of the address separator in the address list.

   - gh-73991(274): Add *note pathlib.Path.copy(): 267, which copies a
     file or directory to another.

   - gh-58933(275): Make *note pdb: aa. return to caller frame correctly
     when ‘f_trace’ of the caller frame is not set

   - gh-82805(276): Support single-dot file extensions in *note
     pathlib.PurePath.suffix: 193f. and related attributes and methods.
     For example, the *note suffixes: 1940. of ‘PurePath('foo.bar.')’
     are now ‘['.bar', '.']’ rather than ‘[]’.  This brings file
     extension splitting in line with *note os.path.splitext(): 1941.

   - gh-118924(277): Remove ‘version’ and ‘version_info’ from *note
     sqlite3: d4.  Patch by Hugo van Kemenade.

   - gh-118928(278): Disallow using a sequence of parameters with named
     placeholders in *note sqlite3: d4. queries.  Patch by Erlend E.
     Aasland.

   - gh-118895(279): Setting attributes on *note typing.NoDefault: 569.
     now raises *note AttributeError: 5f0. instead of *note TypeError:
     198.

   - gh-118868(280): Fixed issue where kwargs were no longer passed to
     the logging handler QueueHandler

   - gh-118827(281): Remove deprecated ‘Quoter’ class from *note
     urllib.parse: 110.  It had previously raised a *note
     DeprecationWarning: 1a3. since Python 3.11.  Patch by Nikita
     Sobolev.

   - gh-118824(282): Remove deprecated ‘pty.master_open()’ and
     ‘pty.slave_open()’.  Use *note pty.openpty(): 301. instead.  Patch
     by Nikita Sobolev.

   - gh-118851(283): ‘ctx’ arguments to the constructors of *note ast:
     9. node classes now default to *note ast.Load(): 4c3.  Patch by
     Jelle Zijlstra.

   - gh-101588(284): Remove copy, deepcopy, and pickle from itertools.
     These had previously raised a DeprecationWarning since Python 3.12.

   - gh-118805(285): Remove 'type', 'choices', and 'metavar' parameters
     of ‘argparse.BooleanOptionalAction’.  They were deprecated since
     Python 3.12.

   - gh-118803(286): ‘typing.ByteString’ and
     ‘collections.abc.ByteString’ are removed.  They had previously
     raised a *note DeprecationWarning: 1a3. since Python 3.12.

   - gh-118798(287): The 'isdst' parameter has been removed from *note
     email.utils.localtime(): 2f7.  Patch by Hugo van Kemenade.

   - gh-118760(288): Restore the default value of ‘tkiter.wantobjects’
     to ‘1’.

   - gh-118760(289): Fix errors in calling Tkinter bindings on Windows.

   - gh-74033(290): Drop support for passing keyword arguments to *note
     pathlib.Path: 266.

   - gh-101357(291): Suppress all *note OSError: 2c0. exceptions from
     *note pathlib.Path.exists(): c0d. and ‘is_*()’ methods, rather than
     a selection of more common errors.  The new behaviour is consistent
     with *note os.path.exists(): c05, *note os.path.isdir(): c07, etc.
     Use *note pathlib.Path.stat(): a26. to retrieve the file status
     without suppressing exceptions.

   - gh-78707(292): Drop support for passing additional positional
     arguments to *note pathlib.PurePath.relative_to(): 2fd. and *note
     is_relative_to(): 2fe.

   - gh-118507(293): Fix *note os.path.isfile(): c08. on Windows for
     pipes.  Speedup *note os.path.isjunction(): 6cb. and *note
     os.path.lexists(): c06. on Windows with a native implementation.

   - gh-118772(294): Allow *note typing.TypeVar: 487. instances without
     a default to follow instances without a default in some cases.
     Patch by Jelle Zijlstra.

   - gh-118714(295): Allow ‘restart’ in post-mortem debugging of *note
     pdb: aa.  Removed restart message when the user quits pdb from
     post-mortem mode.

   - gh-118673(296): Removed executable bits and shebang from stdlib
     modules.

   - gh-110863(297): *note os.path.realpath(): 262. now suppresses any
     *note OSError: 2c0. from *note os.readlink(): b1c. when 'strict'
     mode is disabled (the default).

   - gh-118263(298): Speed up *note os.path.splitroot(): 6cc. & *note
     os.path.normpath(): 1521. with a direct C call.

   - gh-110190(299): Fix ctypes structs with array on SPARC by setting
     ‘MAX_STRUCT_SIZE’ to 32 in stgdict.  Patch by Jakub Kulik

   - gh-118033(300): Fix *note dataclasses.dataclass(): 4e2. not
     creating a ‘__weakref__’ slot when subclassing *note
     typing.Generic: 179e.

   - gh-117766(301): Always use *note str(): 169. to print ‘choices’ in
     *note argparse: 7.

   - gh-106531(302): In *note importlib.resources: 7f, sync with
     importlib_resources 6.3.2(303), including: ‘MultiplexedPath’ now
     expects ‘Traversable’ paths, deprecating string arguments to
     ‘MultiplexedPath’; Enabled support for resources in namespace
     packages in zip files; Fixed ‘NotADirectoryError’ when calling
     files on a subdirectory of a namespace package.

   - gh-115937(304): Removed extra preprocessing for the ‘__signature__’
     attribute: the code just check if it’s a *note inspect.Signature:
     4e4. instance.  Patch by Sergey B Kirpichev.

   - gh-115808(305): Add *note operator.is_none(): 255. and *note
     operator.is_not_none(): 256. functions.

   - gh-114264(306): Improve performance of *note copy.deepcopy(): d67.
     by adding a fast path for atomic types.

   - gh-113878(307): Add 'doc' parameter to *note dataclasses.field():
     1942, so it can be stored and shown as a documentation / metadata.
     If ‘@dataclass(slots=True)’ is used, then the supplied string is
     available in the *note __slots__: 16f2. dict.  Otherwise, the
     supplied string is only available in the corresponding *note
     dataclasses.Field: 1943. object.

     In order to support this feature we are changing the ‘__slots__’
     format in dataclasses from *note tuple: 614. to *note dict: 183.
     when documentation / metadata is present.

   - gh-113978(308): Ignore warnings on text completion inside REPL.

   - gh-113008(309): Correct argparse usage output for required,
     mutually exclusive groups containing a positional argument

   - gh-108172(310): ‘webbrowser’ honors OS preferred browser on Linux
     when its desktop entry name contains the text of a known browser
     name.

   - gh-109109(311): You can now get the raw TLS certificate chains from
     TLS connections via *note ssl.SSLSocket.get_verified_chain(): 1944.
     and *note ssl.SSLSocket.get_unverified_chain(): 1945. methods.

     Contributed by Mateusz Nowak.

   - gh-105623(312): Fix performance degradation in *note
     logging.handlers.RotatingFileHandler: 1929.  Patch by Craig Robson.

   - gh-102450(313): Add missing ISO-8601 24:00 alternative to midnight
     of next day to *note datetime.datetime.fromisoformat(): 82b. and
     *note datetime.time.fromisoformat(): 82a.  Patch by Izan
     «TizzySaurus» Robinson (<tizzysaurus@gmail.com>)

   - gh-103956(314): Fix lack of newline characters in *note trace: 103.
     module output when line tracing is enabled but source code line for
     current frame is not available.

   - gh-92081(315): Fix missing spaces in email headers when the spaces
     are mixed with encoded 8-bit characters.

   - gh-103194(316): Prepare Tkinter for C API changes in Tcl 8.7/9.0 to
     avoid ‘_tkinter.Tcl_Obj’ being unexpectedly returned instead of
     *note bool: 3c3, *note str: 169, *note bytearray: 344, or *note
     int: 19b.

   - gh-87106(317): Fixed handling in *note inspect.Signature.bind():
     187a. of keyword arguments having the same name as positional-only
     arguments when a variadic keyword argument (e.g.  ‘**kwargs’) is
     present.

   - gh-103134(318): Add additional methods to *note proxy objects: 24c.
     in the ‘multiprocessing’ module:

        * ‘clear()’ and ‘copy()’ for proxies of *note list: 24d.

        * *note fromkeys(): 24e, ‘reversed(d)’, ‘d | {}’, ‘{} | d’, ‘d
          |= {'b': 2}’ for proxies of *note dict: 183.

   - bpo-45767(319): Fix integer conversion in *note os.major(): 1946,
     *note os.minor(): 1947, and *note os.makedev(): 1948.  Support
     device numbers larger than ‘2**63-1’.  Support non-existent device
     number (‘NODEV’).

   - bpo-44864(320): Do not translate user-provided strings in *note
     argparse.ArgumentParser: 1bd.

   - bpo-41843(321): Solaris now uses *note os.sendfile(): d07.
     fast-copy syscall for more efficient *note shutil: ca. file copy
     related functions.

   - bpo-15987(322): Implemented *note ast.compare(): 1bf. for comparing
     two ASTs.  Patch by Batuhan Taskaya with some help from Jeremy
     Hylton.

   - gh-67693(323): Fix *note urllib.parse.urlunparse(): 1927. and *note
     urllib.parse.urlunsplit(): 1926. for URIs with path starting with
     multiple slashes and no authority.  Based on patch by Ashwin
     Ramaswami.

   - bpo-14074(324): Fix *note argparse: 7. metavar processing to allow
     positional arguments to have a tuple metavar.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/125422

   (2) https://github.com/python/cpython/issues/100141

   (3) https://github.com/python/cpython/issues/53203

   (4) https://github.com/python/cpython/issues/125206

   (5) https://github.com/python/cpython/issues/89967

   (6) https://github.com/python/cpython/issues/125260

   (7) https://github.com/python/cpython/issues/125243

   (8) https://github.com/python/cpython/issues/125254

   (9) https://github.com/python/cpython/issues/125235

   (10) https://github.com/python/cpython/issues/61011

   (11) https://github.com/python/cpython/issues/125118

   (12) https://github.com/python/cpython/issues/125069

   (13) https://github.com/python/cpython/issues/125096

   (14) https://github.com/python/cpython/issues/124969

   (15) https://github.com/python/cpython/issues/124960

   (16) https://github.com/python/cpython/issues/69998

   (17) https://github.com/python/cpython/issues/124958

   (18) https://github.com/python/cpython/issues/53203

   (19) https://github.com/python/cpython/issues/123961

   (20) https://peps.python.org/pep-0489/

   (21) https://github.com/python/cpython/issues/124944

   (22) https://github.com/python/cpython/issues/117151

   (23) https://github.com/python/cpython/issues/90102

   (24) https://github.com/python/cpython/issues/124917

   (25) https://github.com/python/cpython/issues/65865

   (26) https://github.com/python/cpython/issues/124653

   (27) https://github.com/python/cpython/issues/91818

   (28) https://github.com/python/cpython/issues/124858

   (29) https://github.com/python/cpython/issues/124390

   (30) https://github.com/python/cpython/issues/85935

   (31) https://github.com/python/cpython/issues/124835

   (32) https://github.com/python/cpython/issues/124693

   (33) https://github.com/python/cpython/issues/124787

   (34) https://github.com/python/cpython/issues/66436

   (35) https://github.com/python/cpython/issues/116850

   (36) https://github.com/python/cpython/issues/101552

   (37) https://github.com/python/cpython/issues/58573

   (38) https://github.com/python/cpython/issues/124594

   (39) https://github.com/python/cpython/issues/61181

   (40) https://github.com/python/cpython/issues/116750

   (41) https://github.com/python/cpython/issues/124552

   (42) https://github.com/python/cpython/issues/124538

   (43) https://github.com/python/cpython/issues/80259

   (44) https://github.com/python/cpython/issues/120378

   (45) https://github.com/python/cpython/issues/124498

   (46) https://github.com/python/cpython/issues/53834

   (47) https://github.com/python/cpython/issues/123884

   (48) https://github.com/python/cpython/issues/123017

   (49) https://github.com/python/cpython/issues/123014

   (50) https://github.com/python/cpython/issues/124176

   (51) https://github.com/python/cpython/issues/124345

   (52) https://github.com/python/cpython/issues/124400

   (53) https://github.com/python/cpython/issues/90562

   (54) https://github.com/python/cpython/issues/104860

   (55) https://github.com/python/cpython/issues/63143

   (56) https://github.com/python/cpython/issues/72795

   (57) https://github.com/python/cpython/issues/59317

   (58) https://github.com/python/cpython/issues/100980

   (59) https://github.com/python/cpython/issues/53780

   (60) https://github.com/python/cpython/issues/124217

   (61) https://github.com/python/cpython/issues/111513

   (62) https://github.com/python/cpython/issues/124248

   (63) https://github.com/python/cpython/issues/81691

   (64) https://github.com/python/cpython/issues/87041

   (65) https://github.com/python/cpython/issues/84559

   (66) https://github.com/python/cpython/issues/124212

   (67) https://github.com/python/cpython/issues/124171

   (68) https://github.com/python/cpython/issues/123978

   (69) https://github.com/python/cpython/issues/123934

   (70) https://github.com/python/cpython/issues/124016

   (71) https://github.com/python/cpython/issues/123968

   (72) https://github.com/python/cpython/issues/123945

   (73) https://github.com/python/cpython/issues/123935

   (74) https://github.com/python/cpython/issues/123892

   (75) https://github.com/python/cpython/issues/84808

   (76) https://github.com/python/cpython/issues/123756

   (77) https://github.com/python/cpython/issues/122765

   (78) https://github.com/python/cpython/issues/123657

   (79) https://github.com/python/cpython/issues/123339

   (80) https://github.com/python/cpython/issues/123374

   (81) https://github.com/python/cpython/issues/123504

   (82) https://github.com/python/cpython/issues/123430

   (83) https://github.com/python/cpython/issues/123446

   (84) https://github.com/python/cpython/issues/123448

   (85) https://github.com/python/cpython/issues/123409

   (86) https://datatracker.ietf.org/doc/html/rfc3596.html#section-2.5

   (87) https://github.com/python/cpython/issues/123089

   (88) https://github.com/python/cpython/issues/123363

   (89) https://github.com/python/cpython/issues/123341

   (90) https://github.com/python/cpython/issues/123340

   (91) https://github.com/python/cpython/issues/119518

   (92) https://github.com/python/cpython/issues/123270

   (93) https://github.com/python/cpython/issues/122905

   (94) https://github.com/python/cpython/issues/73991

   (95) https://github.com/python/cpython/issues/123228

   (96) https://github.com/python/cpython/issues/123240

   (97) https://github.com/python/cpython/issues/76960

   (98) https://github.com/python/cpython/issues/116810

   (99) https://github.com/python/cpython/issues/123243

   (100) https://github.com/python/cpython/issues/122546

   (101) https://github.com/python/cpython/issues/123213

   (102) https://github.com/python/cpython/issues/85110

   (103) https://github.com/python/cpython/issues/123165

   (104) https://github.com/python/cpython/issues/122909

   (105) https://github.com/python/cpython/issues/123084

   (106) https://github.com/python/cpython/issues/123085

   (107) https://github.com/python/cpython/issues/123067

   (108) https://github.com/python/cpython/issues/123049

   (109) https://github.com/python/cpython/issues/121735

   (110) https://github.com/python/cpython/issues/122981

   (111) https://github.com/python/cpython/issues/122903

   (112) https://github.com/python/cpython/issues/122905

   (113) https://github.com/python/cpython/issues/122873

   (114) https://github.com/python/cpython/issues/122858

   (115) https://github.com/python/cpython/issues/116263

   (116) https://github.com/python/cpython/issues/105376

   (117) https://github.com/python/cpython/issues/122311

   (118) https://github.com/python/cpython/issues/122744

   (119) https://github.com/python/cpython/issues/118761

   (120) https://github.com/python/cpython/issues/118974

   (121) https://github.com/python/cpython/issues/118814

   (122) https://github.com/python/cpython/issues/122637

   (123) https://github.com/python/cpython/issues/122478

   (124) https://github.com/python/cpython/issues/116622

   (125) https://github.com/python/cpython/issues/82378

   (126) https://github.com/python/cpython/issues/122334

   (127) https://github.com/python/cpython/issues/122459

   (128) https://github.com/python/cpython/issues/87320

   (129) https://github.com/python/cpython/issues/122272

   (130) https://github.com/python/cpython/issues/122400

   (131) https://github.com/python/cpython/issues/122311

   (132) https://github.com/python/cpython/issues/121650

   (133) https://github.com/python/cpython/issues/121650

   (134) https://github.com/python/cpython/issues/122332

   (135) https://github.com/python/cpython/issues/105733

   (136) https://github.com/python/cpython/issues/122213

   (137) https://github.com/python/cpython/issues/119180

   (138) https://peps.python.org/pep-0749/

   (139) https://github.com/python/cpython/issues/119180

   (140) https://github.com/python/cpython/issues/122170

   (141) https://github.com/python/cpython/issues/122163

   (142) https://github.com/python/cpython/issues/122129

   (143) https://github.com/python/cpython/issues/122145

   (144) https://github.com/python/cpython/issues/121723

   (145) https://github.com/python/cpython/issues/82951

   (146) https://github.com/python/cpython/issues/120754

   (147) https://github.com/python/cpython/issues/113785

   (148) https://github.com/python/cpython/issues/122088

   (149) https://github.com/python/cpython/issues/122081

   (150) https://github.com/python/cpython/issues/73991

   (151) https://github.com/python/cpython/issues/121268

   (152) https://github.com/python/cpython/issues/119698

   (153) https://github.com/python/cpython/issues/121889

   (154) https://github.com/python/cpython/issues/121804

   (155) https://github.com/python/cpython/issues/121797

   (156) https://github.com/python/cpython/issues/121798

   (157) https://github.com/python/cpython/issues/120930

   (158) https://github.com/python/cpython/issues/92081

   (159) https://github.com/python/cpython/issues/57141

   (160) https://github.com/python/cpython/issues/121245

   (161) https://github.com/python/cpython/issues/121249

   (162) https://github.com/python/cpython/issues/121486

   (163) https://github.com/python/cpython/issues/121474

   (164) https://github.com/python/cpython/issues/121450

   (165) https://github.com/python/cpython/issues/119169

   (166) https://github.com/python/cpython/issues/121423

   (167) https://github.com/python/cpython/issues/59110

   (168) https://github.com/python/cpython/issues/119004

   (169) https://github.com/python/cpython/issues/121313

   (170) https://github.com/python/cpython/issues/121332

   (171) https://github.com/python/cpython/issues/121245

   (172) https://github.com/python/cpython/issues/121210

   (173) https://github.com/python/cpython/issues/121163

   (174) https://github.com/python/cpython/issues/121151

   (175) https://github.com/python/cpython/issues/121141

   (176) https://github.com/python/cpython/issues/87744

   (177) https://github.com/python/cpython/issues/121027

   (178) https://github.com/python/cpython/issues/121027

   (179) https://github.com/python/cpython/issues/117784

   (180) https://github.com/python/cpython/issues/121025

   (181) https://github.com/python/cpython/issues/121018

   (182) https://github.com/python/cpython/issues/119614

   (183) https://github.com/python/cpython/issues/120910

   (184) https://github.com/python/cpython/issues/61103

   (185) https://github.com/python/cpython/issues/120888

   (186) https://github.com/python/cpython/issues/101830

   (187) https://github.com/python/cpython/issues/120678

   (188) https://github.com/python/cpython/issues/120811

   (189) https://github.com/python/cpython/issues/120782

   (190) https://github.com/python/cpython/issues/120713

   (191) https://github.com/python/cpython/issues/120769

   (192) https://github.com/python/cpython/issues/120780

   (193) https://github.com/python/cpython/issues/41431

   (194) https://github.com/python/cpython/issues/120743

   (195) https://github.com/python/cpython/issues/120732

   (196) https://github.com/python/cpython/issues/111259

   (197) https://github.com/python/cpython/issues/120683

   (198) https://github.com/python/cpython/issues/118710

   (199) https://github.com/python/cpython/issues/120633

   (200) https://github.com/python/cpython/issues/120606

   (201) https://github.com/python/cpython/issues/120284

   (202) https://github.com/python/cpython/issues/120541

   (203) https://github.com/python/cpython/issues/120495

   (204) https://github.com/python/cpython/issues/120388

   (205) https://github.com/python/cpython/issues/120381

   (206) https://github.com/python/cpython/issues/90425

   (207) https://github.com/python/cpython/issues/120343

   (208) https://github.com/python/cpython/issues/119180

   (209) https://peps.python.org/pep-0649/

   (210) https://peps.python.org/pep-0749/

   (211) https://github.com/python/cpython/issues/119600

   (212) https://github.com/python/cpython/issues/120289

   (213) https://github.com/python/cpython/issues/82017

   (214) https://github.com/python/cpython/issues/114053

   (215) https://github.com/python/cpython/issues/114053

   (216) https://peps.python.org/pep-0695/

   (217) https://github.com/python/cpython/issues/120268

   (218) https://github.com/python/cpython/issues/120244

   (219) https://github.com/python/cpython/issues/120254

   (220) https://github.com/python/cpython/issues/120211

   (221) https://github.com/python/cpython/issues/71587

   (222) https://github.com/python/cpython/issues/117983

   (223) https://github.com/python/cpython/issues/120157

   (224) https://github.com/python/cpython/issues/120161

   (225) https://github.com/python/cpython/issues/119698

   (226) https://github.com/python/cpython/issues/120121

   (227) https://github.com/python/cpython/issues/119933

   (228) https://github.com/python/cpython/issues/120029

   (229) https://github.com/python/cpython/issues/120108

   (230) https://github.com/python/cpython/issues/120056

   (231) https://github.com/python/cpython/issues/112672

   (232) https://github.com/python/cpython/issues/120057

   (233) https://github.com/python/cpython/issues/120029

   (234) https://github.com/python/cpython/issues/119819

   (235) https://github.com/python/cpython/issues/65454

   (236) https://github.com/python/cpython/issues/117142

   (237) https://github.com/python/cpython/issues/118835

   (238) https://github.com/python/cpython/issues/81936

   (239) https://github.com/python/cpython/issues/117398

   (240) https://github.com/python/cpython/issues/119824

   (241) https://github.com/python/cpython/issues/119838

   (242) https://github.com/python/cpython/issues/119770

   (243) https://github.com/python/cpython/issues/89727

   (244) https://github.com/python/cpython/issues/119577

   (245) https://github.com/python/cpython/issues/89727

   (246) https://github.com/python/cpython/issues/93963

   (247) https://github.com/python/cpython/issues/119118

   (248) https://github.com/python/cpython/issues/89727

   (249) https://github.com/python/cpython/issues/119594

   (250) https://github.com/python/cpython/issues/119588

   (251) https://github.com/python/cpython/issues/119562

   (252) https://github.com/python/cpython/issues/119555

   (253) https://github.com/python/cpython/issues/118908

   (254) https://github.com/python/cpython/issues/117865

   (255) https://github.com/python/cpython/issues/119127

   (256) https://github.com/python/cpython/issues/113892

   (257) https://github.com/python/cpython/issues/119506

   (258) https://github.com/python/cpython/issues/69214

   (259) https://github.com/python/cpython/issues/119105

   (260) https://github.com/python/cpython/issues/119443

   (261) https://github.com/python/cpython/issues/119461

   (262) https://github.com/python/cpython/issues/117398

   (263) https://github.com/python/cpython/issues/118894

   (264) https://github.com/python/cpython/issues/118830

   (265) https://github.com/python/cpython/issues/118911

   (266) https://github.com/python/cpython/issues/115225

   (267) https://github.com/python/cpython/issues/111201

   (268) https://github.com/python/cpython/issues/119189

   (269) https://github.com/python/cpython/issues/119174

   (270) https://github.com/python/cpython/issues/119121

   (271) https://github.com/python/cpython/issues/119105

   (272) https://github.com/python/cpython/issues/119113

   (273) https://github.com/python/cpython/issues/118643

   (274) https://github.com/python/cpython/issues/73991

   (275) https://github.com/python/cpython/issues/58933

   (276) https://github.com/python/cpython/issues/82805

   (277) https://github.com/python/cpython/issues/118924

   (278) https://github.com/python/cpython/issues/118928

   (279) https://github.com/python/cpython/issues/118895

   (280) https://github.com/python/cpython/issues/118868

   (281) https://github.com/python/cpython/issues/118827

   (282) https://github.com/python/cpython/issues/118824

   (283) https://github.com/python/cpython/issues/118851

   (284) https://github.com/python/cpython/issues/101588

   (285) https://github.com/python/cpython/issues/118805

   (286) https://github.com/python/cpython/issues/118803

   (287) https://github.com/python/cpython/issues/118798

   (288) https://github.com/python/cpython/issues/118760

   (289) https://github.com/python/cpython/issues/118760

   (290) https://github.com/python/cpython/issues/74033

   (291) https://github.com/python/cpython/issues/101357

   (292) https://github.com/python/cpython/issues/78707

   (293) https://github.com/python/cpython/issues/118507

   (294) https://github.com/python/cpython/issues/118772

   (295) https://github.com/python/cpython/issues/118714

   (296) https://github.com/python/cpython/issues/118673

   (297) https://github.com/python/cpython/issues/110863

   (298) https://github.com/python/cpython/issues/118263

   (299) https://github.com/python/cpython/issues/110190

   (300) https://github.com/python/cpython/issues/118033

   (301) https://github.com/python/cpython/issues/117766

   (302) https://github.com/python/cpython/issues/106531

   (303) 
https://importlib-resources.readthedocs.io/en/latest/history.html#v6-3-2

   (304) https://github.com/python/cpython/issues/115937

   (305) https://github.com/python/cpython/issues/115808

   (306) https://github.com/python/cpython/issues/114264

   (307) https://github.com/python/cpython/issues/113878

   (308) https://github.com/python/cpython/issues/113978

   (309) https://github.com/python/cpython/issues/113008

   (310) https://github.com/python/cpython/issues/108172

   (311) https://github.com/python/cpython/issues/109109

   (312) https://github.com/python/cpython/issues/105623

   (313) https://github.com/python/cpython/issues/102450

   (314) https://github.com/python/cpython/issues/103956

   (315) https://github.com/python/cpython/issues/92081

   (316) https://github.com/python/cpython/issues/103194

   (317) https://github.com/python/cpython/issues/87106

   (318) https://github.com/python/cpython/issues/103134

   (319) https://bugs.python.org/issue?@action=redirect&bpo=45767

   (320) https://bugs.python.org/issue?@action=redirect&bpo=44864

   (321) https://bugs.python.org/issue?@action=redirect&bpo=41843

   (322) https://bugs.python.org/issue?@action=redirect&bpo=15987

   (323) https://github.com/python/cpython/issues/67693

   (324) https://bugs.python.org/issue?@action=redirect&bpo=14074


File: python.info,  Node: IDLE<7>,  Next: Documentation<13>,  Prev: Library<45>,  Up: Python 3 14 0 alpha 1

1.24.18.7 IDLE
..............

   - gh-122392(1): Increase currently inadequate vertical spacing for
     the IDLE browsers (path, module, and stack) on high-resolution
     monitors.

   - gh-112938(2): Fix uninteruptable hang when Shell gets rapid
     continuous output.

   - gh-122482(3): Change About IDLE to direct users to
     discuss.python.org instead of the now unused idle-dev email and
     mailing list.

   - gh-78889(4): Stop Shell freezes by blocking user access to
     non-method sys.stdout.shell attributes, which are all private.

   - gh-120083(5): Add explicit black IDLE Hovertip foreground color
     needed for recent macOS. Fixes Sonoma showing unreadable white on
     pale yellow.  Patch by John Riggles.

   - gh-120104(6): Fix padding in config and search dialog windows in
     IDLE.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/122392

   (2) https://github.com/python/cpython/issues/112938

   (3) https://github.com/python/cpython/issues/122482

   (4) https://github.com/python/cpython/issues/78889

   (5) https://github.com/python/cpython/issues/120083

   (6) https://github.com/python/cpython/issues/120104


File: python.info,  Node: Documentation<13>,  Next: Core and Builtins<40>,  Prev: IDLE<7>,  Up: Python 3 14 0 alpha 1

1.24.18.8 Documentation
.......................

   - gh-124872(1): Added definitions for *note context: 194b, *note
     current context: 194c, and *note context management protocol: 194d,
     updated related definitions to be consistent, and expanded the
     documentation for *note contextvars.Context: 177.

   - gh-125018(2): The *note importlib.metadata: 7e. documentation now
     includes semantic cross-reference targets for the significant
     documented APIs.  This means intersphinx references like *note
     importlib.metadata.version(): 194e. will now work as expected.

   - gh-124720(3): Update «Using Python on a Mac» section of the «Python
     Setup and Usage» document and include information on installing
     free-threading support.

   - gh-124457(4): Remove coverity scan from the CPython repo.  It has
     not been used since 2020 and is currently unmaintained.

   - gh-116622(5): Add an Android platform guide, and flag modules not
     available on Android.

   - gh-123976(6): Refresh docs around custom providers.

   - gh-70870(7): Clarified the dual usage of the term «free variable»
     (both the formal meaning of any reference to names defined outside
     the local scope, and the narrower pragmatic meaning of nonlocal
     variables named in ‘co_freevars’).

   - gh-121277(8): Writers of CPython’s documentation can now use ‘next’
     as the version for the ‘versionchanged’, ‘versionadded’,
     ‘deprecated’ directives.

   - gh-117765(9): Improved documentation for *note
     unittest.mock.patch.dict(): 194f.

   - gh-121749(10): Fix documentation for *note PyModule_AddObjectRef():
     60a.

   - gh-120012(11): Clarify the behaviours of *note
     multiprocessing.Queue.empty(): 1950. and *note
     multiprocessing.SimpleQueue.empty(): 1951. on closed queues.  Patch
     by Bénédikt Tran.

   - gh-119574(12): Added some missing environment variables to the
     output of *note -help-env: 809.

   - bpo-34008(13): The *note Py_Main(): e20. documentation moved from
     the «Very High Level API» section to the «Initialization and
     Finalization» section.

     Also make it explicit that we expect ‘Py_Main’ to typically be
     called instead of ‘Py_Initialize’ rather than after it (since
     ‘Py_Main’ makes its own call to ‘Py_Initialize’).  Document that
     calling both is supported but is version dependent on which
     settings will be applied correctly.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/124872

   (2) https://github.com/python/cpython/issues/125018

   (3) https://github.com/python/cpython/issues/124720

   (4) https://github.com/python/cpython/issues/124457

   (5) https://github.com/python/cpython/issues/116622

   (6) https://github.com/python/cpython/issues/123976

   (7) https://github.com/python/cpython/issues/70870

   (8) https://github.com/python/cpython/issues/121277

   (9) https://github.com/python/cpython/issues/117765

   (10) https://github.com/python/cpython/issues/121749

   (11) https://github.com/python/cpython/issues/120012

   (12) https://github.com/python/cpython/issues/119574

   (13) https://bugs.python.org/issue?@action=redirect&bpo=34008


File: python.info,  Node: Core and Builtins<40>,  Next: Library<46>,  Prev: Documentation<13>,  Up: Python 3 14 0 alpha 1

1.24.18.9 Core and Builtins
...........................

   - gh-124375(1): Fix a crash in the free threading build when the GC
     runs concurrently with a new thread starting.

   - gh-125221(2): Fix possible race condition when calling *note
     __reduce_ex__(): 1953. for the first time in the free threading
     build.

   - gh-125174(3): Make the handling of reference counts of immortal
     objects more robust.  Immortal objects with reference counts that
     deviate from their original reference count by up to a billion
     (half a billion on 32 bit builds) are still counted as immortal.

   - gh-125039(4): Make ‘this_instr’ and ‘prev_instr’ const in cases
     generator.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/124375

   (2) https://github.com/python/cpython/issues/125221

   (3) https://github.com/python/cpython/issues/125174

   (4) https://github.com/python/cpython/issues/125039


File: python.info,  Node: Library<46>,  Next: Core and Builtins<41>,  Prev: Core and Builtins<40>,  Up: Python 3 14 0 alpha 1

1.24.18.10 Library
..................

   - gh-125008(1): Fix *note tokenize.untokenize(): 189b. producing
     invalid syntax for double braces preceded by certain escape
     characters.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/125008


File: python.info,  Node: Core and Builtins<41>,  Next: Library<47>,  Prev: Library<46>,  Up: Python 3 14 0 alpha 1

1.24.18.11 Core and Builtins
............................

   - gh-124871(1): Fix compiler bug (in some versions of 3.13) where an
     assertion fails during reachability analysis.

   - gh-123378(2): Fix a crash in the *note __str__(): 831. method of
     *note UnicodeError: 462. objects when the *note UnicodeError.start:
     18a8. and *note UnicodeError.end: 18a9. values are invalid or
     out-of-range.  Patch by Bénédikt Tran.

   - gh-118093(3): Improve the experimental JIT compiler’s ability to
     stay «on trace» when encountering highly-biased branches.

   - gh-124642(4): Fixed scalability issue in free-threaded builds for
     lock-free reads from dictionaries in multi-threaded scenarios

   - gh-116510(5): Fix a crash caused by immortal interned strings being
     shared between sub-interpreters that use basic single-phase init.
     In that case, the string can be used by an interpreter that
     outlives the interpreter that created and interned it.  For
     interpreters that share obmalloc state, also share the interned
     dict with the main interpreter.

   - gh-116510(6): Fix a bug that can cause a crash when
     sub-interpreters use «basic» single-phase extension modules.
     Shared objects could refer to PyGC_Head nodes that had been freed
     as part of interpreter cleanup.

   - gh-119180(7): The ‘__main__’ module no longer always contains an
     ‘__annotations__’ dictionary in its global namespace.

   - gh-124547(8): When deallocating an object with inline values whose
     ‘__dict__’ is still live: if memory allocation for the inline
     values fails, clear the dictionary.  Prevents an interpreter crash.

   - gh-124513(9): Fix a crash in FrameLocalsProxy constructor: check
     the number of arguments.  Patch by Victor Stinner.

   - gh-124442(10): Fix nondeterminism in compilation by sorting the
     value of *note __static_attributes__: 477.  Patch by kp2pml30.

   - gh-124285(11): Fix bug where ‘bool(a)’ can be invoked more than
     once during the evaluation of a compound boolean expression.

   - gh-123856(12): Fix PyREPL failure when a keyboard interrupt is
     triggered after using a history search

   - gh-65961(13): Deprecate the setting and using ‘__package__’ and
     ‘__cached__’.

   - gh-119726(14): The JIT now generates more efficient code for calls
     to C functions resulting in up to 0.8% memory savings and 1.5%
     speed improvement on AArch64.  Patch by Diego Russo.

   - gh-122878(15): Use the ‘pager’ binary, if available (e.g.  on
     Debian and derivatives), to display REPL ‘help()’.

   - gh-124188(16): Fix reading and decoding a line from the source file
     with non-UTF-8 encoding for syntax errors raised in the compiler.

   - gh-124027(17): Support ‘<page up>’, ‘<page down>’, and ‘<delete>’
     keys in the Python REPL when ‘$TERM’ is set to ‘vt100’.

   - gh-124022(18): Fix bug where docstring is removed from classes in
     interactive mode.

   - gh-123958(19): docstrings are now removed from the optimized AST in
     optimization level 2.

   - gh-123923(20): The ‘f_executable’ field in the internal *note
     _PyInterpreterFrame: 1956. struct now uses a tagged pointer.
     Profilers and debuggers that uses this field should clear the least
     significant bit to recover the *note PyObject: 5df.* pointer.

   - gh-77894(21): Fix possible crash in the garbage collector when it
     tries to break a reference loop containing a *note memoryview: 165.
     object.  Now a ‘memoryview’ object can only be cleared if there are
     no buffers that refer it.

   - gh-120221(22): asyncio REPL is now again properly recognizing
     KeyboardInterrupts.  Display of exceptions raised in secondary
     threads is fixed.

   - gh-119310(23): Allow the new interactive shell to read history
     files written with the editline library that use unicode-escaped
     entries.  Patch by aorcajo and Łukasz Langa.

   - gh-123572(24): Fix key mappings for various F-keys in Windows for
     the new REPL. Patch by devdanzin

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/124871

   (2) https://github.com/python/cpython/issues/123378

   (3) https://github.com/python/cpython/issues/118093

   (4) https://github.com/python/cpython/issues/124642

   (5) https://github.com/python/cpython/issues/116510

   (6) https://github.com/python/cpython/issues/116510

   (7) https://github.com/python/cpython/issues/119180

   (8) https://github.com/python/cpython/issues/124547

   (9) https://github.com/python/cpython/issues/124513

   (10) https://github.com/python/cpython/issues/124442

   (11) https://github.com/python/cpython/issues/124285

   (12) https://github.com/python/cpython/issues/123856

   (13) https://github.com/python/cpython/issues/65961

   (14) https://github.com/python/cpython/issues/119726

   (15) https://github.com/python/cpython/issues/122878

   (16) https://github.com/python/cpython/issues/124188

   (17) https://github.com/python/cpython/issues/124027

   (18) https://github.com/python/cpython/issues/124022

   (19) https://github.com/python/cpython/issues/123958

   (20) https://github.com/python/cpython/issues/123923

   (21) https://github.com/python/cpython/issues/77894

   (22) https://github.com/python/cpython/issues/120221

   (23) https://github.com/python/cpython/issues/119310

   (24) https://github.com/python/cpython/issues/123572


File: python.info,  Node: Library<47>,  Next: Core and Builtins<42>,  Prev: Core and Builtins<41>,  Up: Python 3 14 0 alpha 1

1.24.18.12 Library
..................

   - gh-123614(1): Add *note turtle.save(): 1958. to easily save Turtle
     drawings as PostScript files.  Patch by Marie Roald and Yngve
     Mardal Moe.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/123614


File: python.info,  Node: Core and Builtins<42>,  Next: Library<48>,  Prev: Library<47>,  Up: Python 3 14 0 alpha 1

1.24.18.13 Core and Builtins
............................

   - gh-123339(1): Setting the ‘__module__’ attribute for a class now
     removes the ‘__firstlineno__’ item from the type’s dict, so they
     will no longer be inconsistent.

   - gh-119034(2): Change ‘<page up>’ and ‘<page down>’ keys of the
     Python REPL to history search forward/backward.  Patch by Victor
     Stinner.

   - gh-123562(3): Improve *note SyntaxError: 18e. message for using
     ‘case ... as ...’ with not a name.

   - gh-123545(4): Fix a double decref in rare cases on experimental JIT
     builds.

   - gh-123484(5): Fix ‘_Py_DebugOffsets’ for long objects to be
     relative to the start of the object rather than the start of a
     subobject.

   - gh-123446(6): Fix empty function name in *note TypeError: 198. when
     builtin magic methods are used without the required args.

   - gh-123440(7): Improve *note SyntaxError: 18e. message for using
     ‘except as’ with not a name.

   - gh-116017(8): Improved JIT memory consumption by periodically
     freeing memory used by infrequently-executed code.  This change is
     especially likely to improve the memory footprint of long-running
     programs.

   - gh-123344(9): Add AST optimizations for type parameter defaults.

   - gh-123321(10): Prevent Parser/myreadline race condition from
     segfaulting on multi-threaded use.  Patch by Bar Harel and Amit
     Wienner.

   - gh-123177(11): Fix a bug causing stray prompts to appear in the
     middle of wrapped lines in the new REPL.

   - gh-122982(12): Extend the deprecation period for bool inversion
     (‘~’) by two years.

   - gh-123271(13): Make concurrent iterations over the same *note
     zip(): 1a0. iterator safe under free-threading.

   - gh-123275(14): Support *note -X gil=1: 16f. and *note PYTHON_GIL=1:
     49b. on non-free-threaded builds.

   - gh-123177(15): Deactivate line wrap in the Apple Terminal via a
     ANSI escape code.  Patch by Pablo Galindo

   - gh-123229(16): Fix valgrind warning by initializing the f-string
     buffers to 0 in the tokenizer.  Patch by Pablo Galindo

   - gh-122298(17): Restore printout of GC stats when
     ‘gc.set_debug(gc.DEBUG_STATS)’ is called.  This feature was
     accidentally removed when implementing incremental GC.

   - gh-121804(18): Correctly show error locations when a *note
     SyntaxError: 18e. is raised in the basic REPL. Patch by Sergey B
     Kirpichev.

   - gh-115776(19): Enables inline values (Python’s equivalent of hidden
     classes) on any class who’s instances are of a fixed size.

   - gh-123142(20): Fix too-wide source location in exception tracebacks
     coming from broken iterables in comprehensions.

   - gh-123048(21): Fix a bug where pattern matching code could emit a
     *note JUMP_FORWARD: 195a. with no source location.

   - gh-118093(22): Break up ‘CALL_ALLOC_AND_ENTER_INIT’ into micro-ops
     and relax requirement for exact args, in order to increase the
     amount of code supported by tier 2.

   - gh-123123(23): Fix displaying *note SyntaxError: 18e. exceptions
     covering multiple lines.  Patch by Pablo Galindo

   - gh-123083(24): Fix a potential use-after-free in
     ‘STORE_ATTR_WITH_HINT’.

   - gh-123022(25): Fix crash in free-threaded build when calling *note
     Py_Initialize(): 460. from a non-main thread.

   - gh-118093(26): Add three specializations for *note CALL_KW: 372.:

        * ‘CALL_KW_PY’ for calls to Python functions

        * ‘CALL_KW_BOUND_METHOD’ for calls to bound methods

        * ‘CALL_KW_NON_PY’ for all other calls

   - gh-122821(27): Make sure that branches in *note while: 195b.
     statements have consistent offsets for *note sys.monitoring: e0.
     ‘while’ statements are now compiled with a simple jump at the end
     of the body, instead of duplicating the test.

   - gh-122907(28): Building with ‘HAVE_DYNAMIC_LOADING’ now works as
     well as it did in 3.12.  Existing deficiences will be addressed
     separately.  (See
     ‘https://github.com/python/cpython/issues/122950’.)

   - gh-122888(29): Fix crash on certain calls to ‘str()’ with
     positional arguments of the wrong type.  Patch by Jelle Zijlstra.

   - gh-118093(30): Improve the experimental JIT’s handling of
     polymorphic code.

   - gh-122697(31): Fixed memory leaks at interpreter shutdown in the
     free-threaded build, and also reporting of leaked memory blocks via
     *note -X showrefcount: 16f.

   - gh-116622(32): Fix Android stdout and stderr messages being
     truncated or lost.

   - gh-122527(33): Fix a crash that occurred when a ‘PyStructSequence’
     was deallocated after its type’s dictionary was cleared by the GC.
     The type’s *note tp_basicsize: b80. now accounts for non-sequence
     fields that aren’t included in the *note Py_SIZE: 986. of the
     sequence.

   - gh-122445(34): Add only fields which are modified via self.* to
     *note __static_attributes__: 477.

   - gh-122417(35): In the free-threaded build, the reference counts for
     heap type objects are now partially stored in a distributed manner
     in per-thread arrays.  This reduces contention on the heap type’s
     reference count fields when creating or destroying instances of the
     same type from multiple threads concurrently.

   - gh-116090(36): Fix an issue in JIT builds that prevented some *note
     for: 34a. loops from correctly firing *note RAISE: 195c. monitoring
     events.

   - gh-122300(37): Preserve AST nodes for f-string with single-element
     format specifiers.  Patch by Pablo Galindo

   - gh-120906(38): *note frame.f_locals: 4a6. now supports arbitrary
     hashable objects as keys.

   - gh-122239(39): When a *note list: 24d, *note tuple: 614. or *note
     dict: 183. with too many elements is unpacked, show the actual
     length in the error message.

   - gh-122245(40): Detection of writes to ‘__debug__’ is moved from the
     compiler’s codegen stage to the symtable.  This means that these
     errors are now detected even in code that is optimized away before
     codegen (such as assertions with the *note -O: 18c. command line
     option).

   - gh-122234(41): Specializations for sums with float and complex
     inputs in *note sum(): 696. now always use compensated summation.
     Also, for integer items in above specializations: *note
     PyLong_AsDouble(): 195d. is used, instead of *note
     PyLong_AsLongAndOverflow(): 146e.  Patch by Sergey B Kirpichev.

   - gh-122208(42): Dictionary watchers now only deliver the
     PyDict_EVENT_ADDED event when the insertion is in a known good
     state to succeed.

   - gh-122160(43): Remove the ‘BUILD_CONST_KEY_MAP’ opcode.  Use *note
     BUILD_MAP: 369. instead.

   - gh-122029(44): Emit ‘c_call’ events in *note sys.setprofile():
     1705. when a ‘PyMethodObject’ pointing to a ‘PyCFunction’ is
     called.

   - gh-122026(45): Fix a bug that caused the tokenizer to not correctly
     identify mismatched parentheses inside f-strings in some
     situations.  Patch by Pablo Galindo

   - gh-99108(46): Python’s hashlib now unconditionally uses the
     vendored HACL* library for Blake2.  Python no longer accepts libb2
     as an optional dependency for Blake2.

     We refreshed HACL* to the latest version, and now vendor HACL*”s
     128-bit and 256-bit wide vector implementations for Blake2, which
     are used on x86/x64 toolchains when the required CPU features are
     available at runtime.

     HACL*”s 128-bit wide vector implementation of Blake2 can also run
     on ARM NEON and Power8, but lacking evidence of a performance gain,
     these are not enabled (yet).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/123339

   (2) https://github.com/python/cpython/issues/119034

   (3) https://github.com/python/cpython/issues/123562

   (4) https://github.com/python/cpython/issues/123545

   (5) https://github.com/python/cpython/issues/123484

   (6) https://github.com/python/cpython/issues/123446

   (7) https://github.com/python/cpython/issues/123440

   (8) https://github.com/python/cpython/issues/116017

   (9) https://github.com/python/cpython/issues/123344

   (10) https://github.com/python/cpython/issues/123321

   (11) https://github.com/python/cpython/issues/123177

   (12) https://github.com/python/cpython/issues/122982

   (13) https://github.com/python/cpython/issues/123271

   (14) https://github.com/python/cpython/issues/123275

   (15) https://github.com/python/cpython/issues/123177

   (16) https://github.com/python/cpython/issues/123229

   (17) https://github.com/python/cpython/issues/122298

   (18) https://github.com/python/cpython/issues/121804

   (19) https://github.com/python/cpython/issues/115776

   (20) https://github.com/python/cpython/issues/123142

   (21) https://github.com/python/cpython/issues/123048

   (22) https://github.com/python/cpython/issues/118093

   (23) https://github.com/python/cpython/issues/123123

   (24) https://github.com/python/cpython/issues/123083

   (25) https://github.com/python/cpython/issues/123022

   (26) https://github.com/python/cpython/issues/118093

   (27) https://github.com/python/cpython/issues/122821

   (28) https://github.com/python/cpython/issues/122907

   (29) https://github.com/python/cpython/issues/122888

   (30) https://github.com/python/cpython/issues/118093

   (31) https://github.com/python/cpython/issues/122697

   (32) https://github.com/python/cpython/issues/116622

   (33) https://github.com/python/cpython/issues/122527

   (34) https://github.com/python/cpython/issues/122445

   (35) https://github.com/python/cpython/issues/122417

   (36) https://github.com/python/cpython/issues/116090

   (37) https://github.com/python/cpython/issues/122300

   (38) https://github.com/python/cpython/issues/120906

   (39) https://github.com/python/cpython/issues/122239

   (40) https://github.com/python/cpython/issues/122245

   (41) https://github.com/python/cpython/issues/122234

   (42) https://github.com/python/cpython/issues/122208

   (43) https://github.com/python/cpython/issues/122160

   (44) https://github.com/python/cpython/issues/122029

   (45) https://github.com/python/cpython/issues/122026

   (46) https://github.com/python/cpython/issues/99108


File: python.info,  Node: Library<48>,  Next: Core and Builtins<43>,  Prev: Core and Builtins<42>,  Up: Python 3 14 0 alpha 1

1.24.18.14 Library
..................

   - gh-121999(1): The default extraction filter for the *note tarfile:
     e4. module is now set to *note 'data': 29a.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/121999


File: python.info,  Node: Core and Builtins<43>,  Next: Library<49>,  Prev: Library<48>,  Up: Python 3 14 0 alpha 1

1.24.18.15 Core and Builtins
............................

   - gh-121860(1): Fix crash when rematerializing a managed dictionary
     after it was deleted.

   - gh-121795(2): Improve performance of set membership testing,
     ‘set.remove()’ and ‘set.discard()’ when the argument is a set.

   - gh-121814(3): Fixed the SegFault when *note PyEval_SetTrace(): 663.
     is used with no Python frame on stack.

   - gh-121295(4): Fix PyREPL console getting into a blocked state after
     interrupting a long paste

   - gh-121794(5): Fix bug in free-threaded Python where a resurrected
     object could lead to a negative ref count assertion failure.

   - gh-121657(6): Improve the *note SyntaxError: 18e. message if the
     user tries to use *note yield from: bc4. outside a function.

   - gh-121609(7): Fix pasting of characters containing unicode
     character joiners in the new REPL. Patch by Marta Gomez Macias

   - gh-121297(8): Previously, incorrect usage of *note await: 18d. or
     asynchronous comprehensions in code removed by the *note -O: 18c.
     option was not flagged by the Python compiler.  Now, such code
     raises *note SyntaxError: 18e.  Patch by Jelle Zijlstra.

   - gh-117482(9): Unexpected slot wrappers are no longer created for
     builtin static types in subinterpreters.

   - gh-121562(10): Optimized performance of hex_from_char by replacing
     switch-case with a lookup table

   - gh-121499(11): Fix a bug affecting how multi-line history was being
     rendered in the new REPL after interacting with the new screen
     cache.  Patch by Pablo Galindo

   - gh-121497(12): Fix a bug that was preventing the REPL to correctly
     respect the history when an input hook was set.  Patch by Pablo
     Galindo

   - gh-121012(13): Tier 2 execution now ensures that list iterators
     remain exhausted, once they become exhausted.

   - gh-121439(14): Allow tuples of length 20 in the freelist to be
     reused.

   - gh-121288(15): *note ValueError: 2ec. messages for *note
     list.index(): 15cc, *note range.index(): 1960, ‘deque.index()’,
     ‘deque.remove()’ and ‘ShareableList.index()’ no longer contain the
     repr of the searched value (which can be arbitrary large) and are
     consistent with error messages for other *note index(): 1961. and
     *note remove(): 1962. methods.

   - gh-121368(16): Fix race condition in ‘_PyType_Lookup’ in the
     free-threaded build due to a missing memory fence.  This could lead
     to ‘_PyType_Lookup’ returning incorrect results on arm64.

   - gh-121149(17): Added specialization for summation of complexes,
     this also improves accuracy of builtin *note sum(): 696. for such
     inputs.  Patch by Sergey B Kirpichev.

   - gh-121130(18): Fix f-strings with debug expressions in format
     specifiers.  Patch by Pablo Galindo

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/121860

   (2) https://github.com/python/cpython/issues/121795

   (3) https://github.com/python/cpython/issues/121814

   (4) https://github.com/python/cpython/issues/121295

   (5) https://github.com/python/cpython/issues/121794

   (6) https://github.com/python/cpython/issues/121657

   (7) https://github.com/python/cpython/issues/121609

   (8) https://github.com/python/cpython/issues/121297

   (9) https://github.com/python/cpython/issues/117482

   (10) https://github.com/python/cpython/issues/121562

   (11) https://github.com/python/cpython/issues/121499

   (12) https://github.com/python/cpython/issues/121497

   (13) https://github.com/python/cpython/issues/121012

   (14) https://github.com/python/cpython/issues/121439

   (15) https://github.com/python/cpython/issues/121288

   (16) https://github.com/python/cpython/issues/121368

   (17) https://github.com/python/cpython/issues/121149

   (18) https://github.com/python/cpython/issues/121130


File: python.info,  Node: Library<49>,  Next: Core and Builtins<44>,  Prev: Core and Builtins<43>,  Up: Python 3 14 0 alpha 1

1.24.18.16 Library
..................

   - gh-121381(1): Remove ‘subprocess._USE_VFORK’ escape hatch code and
     documentation.  It was added just in case, and doesn’t have any
     known cases that require it.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/121381


File: python.info,  Node: Core and Builtins<44>,  Next: Library<50>,  Prev: Library<49>,  Up: Python 3 14 0 alpha 1

1.24.18.17 Core and Builtins
............................

   - gh-119726(1): Optimize code layout for calls to C functions from
     the JIT on AArch64.  Patch by Diego Russo.

   - gh-121115(2): *note PyLong_AsNativeBytes(): 606. no longer uses
     *note __index__(): 19e. methods by default.  The
     ‘Py_ASNATIVEBYTES_ALLOW_INDEX’ flag has been added to allow it.

   - gh-120838(3): *note Py_Finalize(): 45f. and *note Py_FinalizeEx():
     f13. now always run with the main interpreter active.

   - gh-113433(4): Subinterpreters now get cleaned up automatically
     during runtime finalization.

   - gh-119726(5): Improve the speed and memory use of C function calls
     from JIT code on AArch64.  Patch by Diego Russo

   - gh-116017(6): Simplify the warmup mechanism used for «side exits»
     in JIT code, resulting in slightly better performance and slightly
     lower memory usage for most platforms.

   - gh-98442(7): Fix too wide source locations of the cleanup
     instructions of a with statement.

   - gh-120754(8): Reduce the number of system calls invoked when
     reading a whole file (ex.  ‘open('a.txt').read()’).  For a sample
     program that reads the contents of the 400+ ‘.rst’ files in the
     cpython repository ‘Doc’ folder, there is an over 10% reduction in
     system call count.

   - gh-119462(9): Make sure that invariants of type versioning are
     maintained: * Superclasses always have their version number
     assigned before subclasses * The version tag is always zero if the
     tag is not valid.  * The version tag is always non-if the tag is
     valid.

   - gh-120437(10): Fix ‘_CHECK_STACK_SPACE’ optimization problems
     introduced in gh-118322(11).

   - gh-120722(12): Correctly set the bytecode position on return
     instructions within lambdas.  Patch by Jelle Zijlstra.

   - gh-120367(13): Fix bug where compiler creates a redundant jump
     during pseudo-op replacement.  Can only happen with a synthetic AST
     that has a try on the same line as the instruction following the
     exception handler.

   - gh-120507(14): Remove the ‘BEFORE_WITH’ and ‘BEFORE_ASYNC_WITH’
     instructions.  Add the new *note LOAD_SPECIAL: 36f. instruction.
     Generate code for ‘with’ and ‘async with’ statements using the new
     instruction.

   - gh-113993(15): Strings interned with *note sys.intern(): 14e3. are
     again garbage-collected when no longer used, as per the
     documentation.  Strings interned with the C function *note
     PyUnicode_InternInPlace(): ab0. are still immortal.  Internals of
     the string interning mechanism have been changed.  This may affect
     performance and identities of *note str: 169. objects.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/119726

   (2) https://github.com/python/cpython/issues/121115

   (3) https://github.com/python/cpython/issues/120838

   (4) https://github.com/python/cpython/issues/113433

   (5) https://github.com/python/cpython/issues/119726

   (6) https://github.com/python/cpython/issues/116017

   (7) https://github.com/python/cpython/issues/98442

   (8) https://github.com/python/cpython/issues/120754

   (9) https://github.com/python/cpython/issues/119462

   (10) https://github.com/python/cpython/issues/120437

   (11) https://github.com/python/cpython/issues/118322

   (12) https://github.com/python/cpython/issues/120722

   (13) https://github.com/python/cpython/issues/120367

   (14) https://github.com/python/cpython/issues/120507

   (15) https://github.com/python/cpython/issues/113993


File: python.info,  Node: Library<50>,  Next: Core and Builtins<45>,  Prev: Core and Builtins<44>,  Up: Python 3 14 0 alpha 1

1.24.18.18 Library
..................

   - gh-120485(1): Add an override of ‘allow_reuse_port’ on classes
     subclassing ‘socketserver.TCPServer’ where ‘allow_reuse_address’ is
     also overridden.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/120485


File: python.info,  Node: Core and Builtins<45>,  Next: Library<51>,  Prev: Library<50>,  Up: Python 3 14 0 alpha 1

1.24.18.19 Core and Builtins
............................

   - gh-120384(1): Fix an array out of bounds crash in
     ‘list_ass_subscript’, which could be invoked via some specifically
     tailored input: including concurrent modification of a list object,
     where one thread assigns a slice and another clears it.

   - gh-120367(2): Fix crash in compiler on code with redundant NOPs and
     JUMPs which show up after exception handlers are moved to the end
     of the code.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/120384

   (2) https://github.com/python/cpython/issues/120367


File: python.info,  Node: Library<51>,  Next: Core and Builtins<46>,  Prev: Core and Builtins<45>,  Up: Python 3 14 0 alpha 1

1.24.18.20 Library
..................

   - gh-120380(1): Fix Python implementation of *note pickle.Pickler:
     c15. for *note bytes: 192. and *note bytearray: 344. objects when
     using protocol version 5.  Patch by Bénédikt Tran.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/120380


File: python.info,  Node: Core and Builtins<46>,  Next: Library<52>,  Prev: Library<51>,  Up: Python 3 14 0 alpha 1

1.24.18.21 Core and Builtins
............................

   - gh-120397(1): Improve the throughput by up to two times for the
     *note str.count(): 1969, *note bytes.count(): 196a. and *note
     bytearray.count(): 177c. methods for counting single characters.

   - gh-120221(2): Deliver real signals on Ctrl-C and Ctrl-Z in the new
     REPL. Patch by Pablo Galindo

   - gh-120346(3): Respect *note PYTHON_BASIC_REPL: 1b6. when running in
     interactive inspect mode (‘python -i’).  Patch by Pablo Galindo

   - gh-93691(4): Fix source locations of instructions generated for the
     iterator of a for statement.

   - gh-120198(5): Fix a crash when multiple threads read and write to
     the same ‘__class__’ of an object concurrently.

   - gh-120298(6): Fix use-after free in ‘list_richcompare_impl’ which
     can be invoked via some specifically tailored evil input.

   - gh-119666(7): Fix a compiler crash in the case where two
     comprehensions in class scope both reference ‘__class__’.

   - gh-119726(8): JIT: Re-use trampolines on AArch64 when creating
     stencils.  Patch by Diego Russo

   - gh-120225(9): Fix crash in compiler on empty block at end of
     exception handler.

   - gh-93691(10): Fix source locations of instructions generated for
     with statements.

   - gh-120097(11): ‘FrameLocalsProxy’ now subclasses
     ‘collections.abc.Mapping’ and can be matched as a mapping in
     ‘match’ statements

   - gh-120080(12): Direct call to the ‘int.__round__()’ now accepts
     ‘None’ as a valid argument.

   - gh-119933(13): Improve *note SyntaxError: 18e. messages for invalid
     expressions in a type parameters bound, a type parameter constraint
     tuple or a default type parameter.  Patch by Bénédikt Tran.

   - gh-119724(14): Reverted improvements to error messages for
     ‘elif’/‘else’ statements not matching any valid statements, which
     made in hard to locate the syntax errors inside those ‘elif’/‘else’
     blocks.

   - gh-119879(15): String search is now slightly faster for certain
     cases.  It now utilizes last character gap (good suffix rule) for
     two-way periodic needles.

   - gh-119842(16): Honor *note PyOS_InputHook(): 7a5. in the new REPL.
     Patch by Pablo Galindo

   - gh-119180(17): *note classmethod(): 48f. and *note staticmethod():
     453. now wrap the *note __annotations__: 458. and *note
     __annotate__: 196b. attributes of their underlying callable lazily.
     See PEP 649(18).  Patch by Jelle Zijlstra.

   - gh-119821(19): Fix execution of *note annotation scopes: 4ac.
     within classes when ‘globals’ is set to a non-dict.  Patch by Jelle
     Zijlstra.

   - gh-118934(20): Make ‘PyEval_GetLocals’ return borrowed reference

   - gh-119740(21): Remove the previously-deprecated delegation of *note
     int(): 19b. to *note __trunc__(): 19c.

   - gh-119689(22): Generate stack effect metadata for pseudo
     instructions from bytecodes.c.

   - gh-109218(23): *note complex(): 197. accepts now a string only as a
     positional argument.  Passing a complex number as the «real» or
     «imag» argument is deprecated; it should only be passed as a single
     positional argument.

   - gh-119548(24): Add a ‘clear’ command to the REPL. Patch by Pablo
     Galindo

   - gh-111999(25): Fix the signature of *note str.format_map(): fd9.

   - gh-119560(26): An invalid assert in beta 1 has been removed.  The
     assert would fail if ‘PyState_FindModule()’ was used in an
     extension module’s init function before the module def had been
     initialized.

   - gh-119369(27): Fix deadlock during thread deletion in free-threaded
     build, which could occur when the GIL was enabled at runtime.

   - gh-119525(28): Fix deadlock involving ‘_PyType_Lookup()’ cache in
     the free-threaded build when the GIL is dynamically enabled at
     runtime.

   - gh-119258(29): Eliminate type version guards in the tier two
     interpreter.

     Note that setting the ‘tp_version_tag’ manually (which has never
     been supported) may result in crashes.

   - gh-119311(30): Fix bug where names are unexpectedly mangled in the
     bases of generic classes.

   - gh-119395(31): Fix bug where names appearing after a generic class
     are mangled as if they are in the generic class.

   - gh-119372(32): Correct invalid corner cases in complex division
     (resulted in ‘(nan+nanj)’ output), e.g.  ‘1/complex('(inf+infj)')’.
     Patch by Sergey B Kirpichev.

   - gh-119180(33): Evaluation of annotations is now deferred.  See PEP
     649(34) for details.

   - gh-119180(35): Replace ‘LOAD_ASSERTION_ERROR’ opcode with *note
     LOAD_COMMON_CONSTANT: 36a. and add support for *note
     NotImplementedError: 36b.

   - gh-119213(36): Non-builtin modules built with argument clinic were
     crashing if used in a subinterpreter before the main interpreter.
     The objects that were causing the problem by leaking between
     interpreters carelessly have been fixed.

   - gh-119011(37): Fixes ‘type.__type_params__’ to return an empty
     tuple instead of a descriptor.

   - gh-118692(38): Avoid creating unnecessary *note StopIteration: df7.
     instances for monitoring.

   - gh-119180(39): Add an ‘__annotate__’ attribute to functions,
     classes, and modules as part of PEP 649(40).  Patch by Jelle
     Zijlstra.

   - gh-119049(41): Fix displaying the source line for warnings created
     by the C API if the *note warnings: 118. module had not yet been
     imported.

   - gh-119057(42): Improve *note ZeroDivisionError: b41. error message.
     Now, all error messages are harmonized: all ‘/’, ‘//’, and ‘%’
     operations just use «division by zero» message.  And ‘0 ** -1’
     operation uses «zero to a negative power».

   - gh-118844(43): Fix build failures when configuring with both
     ‘--disable-gil’ and ‘--enable-experimental-jit’.

   - gh-118921(44): Add ‘copy()’ method for ‘FrameLocalsProxy’ which
     returns a snapshot ‘dict’ for local variables.

   - gh-117657(45): Fix data races on the field that stores a pointer to
     the interpreter’s main thread that occur in free-threaded builds.

   - gh-118750(46): If the C version of the ‘decimal’ module is
     available, ‘int(str)’ now uses it to supply an asymptotically much
     faster conversion.  However, this only applies if the string
     contains over about 2 million digits.

   - gh-118767(47): Using *note NotImplemented: 1a2. in a boolean
     context now raises *note TypeError: 198.  Contributed by Jelle
     Zijlstra.

   - gh-118561(48): Fix race condition in free-threaded build where
     *note list.extend(): 602. could expose uninitialised memory to
     concurrent readers.

   - gh-117139(49): Convert the Python evaluation stack to use internal
     stack references.  The purpose is to support tagged pointers.  In
     PEP 703(50), this will allow for its form of deferred reference
     counting.  For both the default and free-threaded builds, this sets
     up the infrastructure for unboxed integers in the future.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/120397

   (2) https://github.com/python/cpython/issues/120221

   (3) https://github.com/python/cpython/issues/120346

   (4) https://github.com/python/cpython/issues/93691

   (5) https://github.com/python/cpython/issues/120198

   (6) https://github.com/python/cpython/issues/120298

   (7) https://github.com/python/cpython/issues/119666

   (8) https://github.com/python/cpython/issues/119726

   (9) https://github.com/python/cpython/issues/120225

   (10) https://github.com/python/cpython/issues/93691

   (11) https://github.com/python/cpython/issues/120097

   (12) https://github.com/python/cpython/issues/120080

   (13) https://github.com/python/cpython/issues/119933

   (14) https://github.com/python/cpython/issues/119724

   (15) https://github.com/python/cpython/issues/119879

   (16) https://github.com/python/cpython/issues/119842

   (17) https://github.com/python/cpython/issues/119180

   (18) https://peps.python.org/pep-0649/

   (19) https://github.com/python/cpython/issues/119821

   (20) https://github.com/python/cpython/issues/118934

   (21) https://github.com/python/cpython/issues/119740

   (22) https://github.com/python/cpython/issues/119689

   (23) https://github.com/python/cpython/issues/109218

   (24) https://github.com/python/cpython/issues/119548

   (25) https://github.com/python/cpython/issues/111999

   (26) https://github.com/python/cpython/issues/119560

   (27) https://github.com/python/cpython/issues/119369

   (28) https://github.com/python/cpython/issues/119525

   (29) https://github.com/python/cpython/issues/119258

   (30) https://github.com/python/cpython/issues/119311

   (31) https://github.com/python/cpython/issues/119395

   (32) https://github.com/python/cpython/issues/119372

   (33) https://github.com/python/cpython/issues/119180

   (34) https://peps.python.org/pep-0649/

   (35) https://github.com/python/cpython/issues/119180

   (36) https://github.com/python/cpython/issues/119213

   (37) https://github.com/python/cpython/issues/119011

   (38) https://github.com/python/cpython/issues/118692

   (39) https://github.com/python/cpython/issues/119180

   (40) https://peps.python.org/pep-0649/

   (41) https://github.com/python/cpython/issues/119049

   (42) https://github.com/python/cpython/issues/119057

   (43) https://github.com/python/cpython/issues/118844

   (44) https://github.com/python/cpython/issues/118921

   (45) https://github.com/python/cpython/issues/117657

   (46) https://github.com/python/cpython/issues/118750

   (47) https://github.com/python/cpython/issues/118767

   (48) https://github.com/python/cpython/issues/118561

   (49) https://github.com/python/cpython/issues/117139

   (50) https://peps.python.org/pep-0703/


File: python.info,  Node: Library<52>,  Next: Core and Builtins<47>,  Prev: Core and Builtins<46>,  Up: Python 3 14 0 alpha 1

1.24.18.22 Library
..................

   - gh-115801(1): Raise ‘TypeError’ when passing a string to *note
     difflib.unified_diff(): 196d. and *note difflib.context_diff():
     196e.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115801


File: python.info,  Node: Core and Builtins<47>,  Next: C API<15>,  Prev: Library<52>,  Up: Python 3 14 0 alpha 1

1.24.18.23 Core and Builtins
............................

   - gh-117558(1): Improve error messages when a string, bytes or
     bytearray object of length 1 is expected.

   - gh-117195(2): Avoid assertion failure for debug builds when calling
     ‘object.__sizeof__(1)’

   - gh-116022(3): Improve the *note __repr__(): 830. output of *note
     AST: 4c4. nodes.

   - gh-114091(4): Changed the error message for awaiting something that
     can’t be awaited from «object <type> can’t be used in an await
     expression» to «”<type>” object can’t be awaited».

   - gh-113190(5): *note Py_Finalize(): 45f. now deletes all interned
     strings.

   - gh-84978(6): Add class methods *note float.from_number(): 194. and
     *note complex.from_number(): 195.

   - gh-95144(7): Improve the error message from ‘a in b’ when ‘b’ is
     not a container to mention the term «container».

   - bpo-24766(8): Fix handling of ‘doc’ argument to subclasses of
     ‘property’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/117558

   (2) https://github.com/python/cpython/issues/117195

   (3) https://github.com/python/cpython/issues/116022

   (4) https://github.com/python/cpython/issues/114091

   (5) https://github.com/python/cpython/issues/113190

   (6) https://github.com/python/cpython/issues/84978

   (7) https://github.com/python/cpython/issues/95144

   (8) https://bugs.python.org/issue?@action=redirect&bpo=24766


File: python.info,  Node: C API<15>,  Next: Build<15>,  Prev: Core and Builtins<47>,  Up: Python 3 14 0 alpha 1

1.24.18.24 C API
................

   - gh-123961(1): Convert the *note curses.window: 1971. static type
     exposed by the ‘PyCursesWindow_Type’ macro in ‘Include/py_curses.h’
     to a *note heap type: b60.  Patch by Bénédikt Tran.

   - gh-124502(2): Add *note PyUnicode_Equal(): 3b2. function to the
     limited C API: test if two strings are equal.  Patch by Victor
     Stinner.

   - gh-124296(3): *note PyDictObject: 64f. no longer maintains a
     private version tag field ‘ma_version_tag’ per PEP 699(4).  This
     field was originally added in Python 3.6 ( PEP 509(5)) and
     deprecated in Python 3.12.

   - gh-124160(6): Fix crash when importing modules containing state and
     single-phase initialization in a subinterpreter.

   - gh-124153(7): Add *note PyType_GetBaseByToken(): 3b0. and *note
     Py_tp_token: 3b1. slot for easier type checking, related to PEP
     489(8) and PEP 630(9).

   - gh-124127(10): In the limited C API 3.14 and newer, *note
     Py_REFCNT(): 2cf. is now implemented as an opaque function call to
     hide implementation details.  Patch by Victor Stinner.

   - gh-123880(11): Fixed a bug that prevented circular imports of
     extension modules that use single-phase initialization.

   - gh-123909(12): *note PyType_FromSpec(): 79e, *note
     PyType_FromSpecWithBases(): 79f. and *note
     PyType_FromModuleAndSpec(): 774. will now fail if the metaclass of
     the new type has custom *note tp_new: 7a0.

   - gh-107954(13): Add functions to configure the Python initialization
     ( PEP 741(14)):

        * *note PyInitConfig_Create(): 387.

        * *note PyInitConfig_Free(): 388.

        * *note PyInitConfig_GetError(): 38a.

        * *note PyInitConfig_GetExitCode(): 38b.

        * *note PyInitConfig_HasOption(): 38f.

        * *note PyInitConfig_GetInt(): 38c.

        * *note PyInitConfig_GetStr(): 38d.

        * *note PyInitConfig_GetStrList(): 38e.

        * *note PyInitConfig_FreeStrList(): 389.

        * *note PyInitConfig_SetInt(): 390.

        * *note PyInitConfig_SetStr(): 391.

        * *note PyInitConfig_SetStrList(): 392.

        * *note PyInitConfig_AddModule(): 37b.

        * *note Py_InitializeFromInitConfig(): 386.

     Patch by Victor Stinner.

   - gh-107954(15): Add functions to get and set the current runtime
     Python configuration:

        * *note PyConfig_Get(): 37c.

        * *note PyConfig_GetInt(): 384.

        * *note PyConfig_Set(): 37d.

        * *note PyConfig_Names(): 385.

     Patch by Victor Stinner.

   - gh-123465(16): *note Py_RELATIVE_OFFSET: 771. is now allowed in
     *note PyMemberDef: 772. for the special offset member
     ‘"__vectorcalloffset__"’, as well as the discouraged special offset
     members ‘"__dictoffset__"’ and ‘"__weaklistoffset__"’

   - gh-100554(17): Added a slot ‘Py_tp_vectorcall’ to set *note
     tp_vectorcall: 1972. via the *note PyType_FromSpec(): 79e. function
     family.  Limited API extensions can use this feature to provide
     more efficient vector call-based implementation of ‘__new__’ and
     ‘__init__’.

   - gh-122854(18): Add *note Py_HashBuffer(): 395. to compute and
     return the hash value of a buffer.  Patch by Antoine Pitrou and
     Victor Stinner.

   - gh-122728(19): Fix *note PyEval_GetLocals(): 5f8. to avoid *note
     SystemError: 796. («bad argument to internal function»).  Patch by
     Victor Stinner.

   - gh-116622(20): Make *note PyObject_Print: 1973. work around a bug
     in Android and OpenBSD which prevented it from throwing an
     exception when trying to write to a read-only stream.

   - gh-105201(21): Add *note PyIter_NextItem(): 398. to replace *note
     PyIter_Next(): 399, which has an ambiguous return value.  Patch by
     Irit Katriel and Erlend Aasland.

   - gh-121489(22): Export private ‘_PyBytes_Join()’ again.

   - gh-121645(23): Add *note PyBytes_Join(sep, iterable): 383.
     function, similar to ‘sep.join(iterable)’ in Python.  Patch by
     Victor Stinner.

   - gh-89364(24): Export the *note PySignal_SetWakeupFd(): 15e2.
     function.  Previously, the function was documented but it couldn’t
     be used in 3rd party code.  Patch by Victor Stinner.

   - gh-113993(25): *note PyUnicode_InternInPlace(): ab0. no longer
     prevents its argument from being garbage collected.

     Several functions that take ‘char *’ are now documented as possibly
     preventing string objects from being garbage collected; refer to
     their documentation for details: *note
     PyUnicode_InternFromString(): 1974, *note PyDict_SetItemString():
     1975, *note PyObject_SetAttrString(): 1976, *note
     PyObject_DelAttrString(): 181a, *note PyUnicode_InternFromString():
     1974, and ‘PyModule_Add*’ convenience functions.

   - gh-113601(26): Removed debug build assertions related to interning
     strings, which were falsely triggered by stable ABI extensions.

   - gh-112136(27): Restore the private ‘_PyArg_Parser’ structure and
     the private ‘_PyArg_ParseTupleAndKeywordsFast()’ function,
     previously removed in Python 3.13 alpha 1.  Patch by Victor
     Stinner.

   - gh-120642(28): Remove the private ‘_Py_CODEUNIT’ type from the
     public C API. The internal ‘pycore_code.h’ header should now be
     used to get this internal type.  Patch by Victor Stinner.

   - gh-120858(29): *note PyDict_Next(): 1977. no longer locks the
     dictionary in the free-threaded build.  The locking needs to be
     done by the caller around the entire iteration loop.

   - gh-120642(30): Remove the following unstable functions:

        * ‘PyUnstable_Replace_Executor()’

        * ‘PyUnstable_SetOptimizer()’

        * ‘PyUnstable_GetOptimizer()’

        * ‘PyUnstable_GetExecutor()’

        * ‘PyUnstable_Optimizer_NewCounter()’

        * ‘PyUnstable_Optimizer_NewUOpOptimizer()’

     Patch by Victor Stinner.

   - gh-120389(31): Add new functions to convert C ‘<stdint.h>’ numbers
     from/to Python *note int: 19b.:

        * *note PyLong_FromInt32(): 3a3.

        * *note PyLong_FromUInt32(): 3a5.

        * *note PyLong_FromInt64(): 3a4.

        * *note PyLong_FromUInt64(): 3a6.

        * *note PyLong_AsInt32(): 39f.

        * *note PyLong_AsUInt32(): 3a1.

        * *note PyLong_AsInt64(): 3a0.

        * *note PyLong_AsUInt64(): 3a2.

     Patch by Victor Stinner.

   - gh-120600(32): In the limited C API 3.14 and newer, *note
     Py_TYPE(): 3c9. is now implemented as an opaque function call to
     hide implementation details.  Patch by Victor Stinner.

   - gh-70278(33): *note PyUnicode_FromFormat(): 62b. no longer produces
     the ending ‘\ufffd’ character for truncated C string when use
     precision with ‘%s’ and ‘%V’.  It now truncates the string before
     the start of truncated multibyte sequences.

   - gh-119771(34): Set *note errno: 5b. in *note _Py_c_pow(): 18da. on
     overflows.  Patch by Sergey B Kirpichev.

   - gh-119182(35): Add a new *note PyUnicodeWriter: 3b3. API to create
     a Python *note str: 169. object:

        * *note PyUnicodeWriter_Create(): 3b4.

        * *note PyUnicodeWriter_Discard(): 3b6.

        * *note PyUnicodeWriter_Finish(): 3b7.

        * *note PyUnicodeWriter_WriteChar(): 3ba.

        * *note PyUnicodeWriter_WriteUTF8(): 3bf.

        * *note PyUnicodeWriter_WriteUCS4(): 3be.

        * *note PyUnicodeWriter_WriteWideChar(): 3c0.

        * *note PyUnicodeWriter_WriteStr(): 3bc.

        * *note PyUnicodeWriter_WriteRepr(): 3bb.

        * *note PyUnicodeWriter_WriteSubstring(): 3bd.

        * *note PyUnicodeWriter_Format(): 3b8.

        * *note PyUnicodeWriter_DecodeUTF8Stateful(): 3b5.

     Patch by Victor Stinner.

   - gh-119613(36): Soft deprecate the *note Py_MEMCPY: 1978. macro: use
     directly ‘memcpy()’ instead.  Patch by Victor Stinner.

   - gh-119775(37): Creating *note immutable types: 3cf. with mutable
     bases was deprecated since 3.12 and now raises a *note TypeError:
     198.

   - gh-119585(38): Fix crash when a thread state that was created by
     *note PyGILState_Ensure(): 64a. calls a destructor that during
     *note PyThreadState_Clear(): 1979. that calls back into *note
     PyGILState_Ensure(): 64a. and *note PyGILState_Release(): 64b.
     This might occur when in the free-threaded build or when using
     thread-local variables whose destructors call *note
     PyGILState_Ensure(): 64a.

   - gh-119613(39): Macros ‘Py_IS_NAN’, ‘Py_IS_INFINITY’ and
     ‘Py_IS_FINITE’ are *note soft deprecated: 23d.

   - gh-119336(40): Restore the removed ‘_PyLong_NumBits()’ function.
     It is used by the pywin32 project.  Patch by Ethan Smith

   - gh-119344(41): The critical section API is now public as part of
     the non-limited C API.

   - gh-119333(42): Add *note PyContext_AddWatcher(): 197a. and *note
     PyContext_ClearWatcher(): 197b. APIs to register callbacks to
     receive notification on enter and exit of context objects.

   - gh-119247(43): Added ‘Py_BEGIN_CRITICAL_SECTION_SEQUENCE_FAST’ and
     ‘Py_END_CRITICAL_SECTION_SEQUENCE_FAST’ macros to make it possible
     to use PySequence_Fast APIs safely when free-threaded, and update
     str.join to work without the GIL using them.

   - gh-111389(44): Add *note PyHASH_MULTIPLIER: 197c. constant: prime
     multiplier used in string and various other hashes.  Patch by
     Victor Stinner.

   - gh-118771(45): Several C declarations with names that didn’t start
     with the ‘Py’ or ‘_Py’ prefixes, which were added by mistake in
     3.13 alpha and beta releases, were moved to internal headers.

   - gh-116984(46): Make mimalloc includes relative to the current file
     to avoid embedders or extensions needing to include
     ‘Internal/mimalloc’ if they are already including internal CPython
     headers.

   - gh-118789(47): Add *note
     PyUnstable_Object_ClearWeakRefsNoCallbacks(): 197d, which clears
     weakrefs without calling their callbacks.

   - gh-118789(48): Restore ‘_PyWeakref_ClearRef’ that was previously
     removed in Python 3.13 alpha 1.

   - gh-117511(49): Make the *note PyMutex: 485. public in the
     non-limited C API.

   - gh-116560(50): Add *note PyLong_GetSign(): 39a. function.  Patch by
     Sergey B Kirpichev.

   - gh-97588(51): Fix creating bitfields in *note ctypes: 2e.
     structures and unions.  Fields no longer overlap.

   - gh-87135(52): Attempting to acquire the GIL after runtime
     finalization has begun in a different thread now causes the thread
     to hang rather than terminate, which avoids potential crashes or
     memory corruption caused by attempting to terminate a thread that
     is running code not specifically designed to support termination.
     In most cases this hanging is harmless since the process will soon
     exit anyway.

     The ‘PyThread_exit_thread’ function is now deprecated.  Its
     behavior is inconsistent across platforms, and it can only be used
     safely in the unlikely case that every function in the entire call
     stack has been designed to support the platform-dependent
     termination mechanism.  It is recommended that users of this
     function change their design to not require thread termination.  In
     the unlikely case that thread termination is needed and can be done
     safely, users may migrate to calling platform-specific APIs such as
     ‘pthread_exit’ (POSIX) or ‘_endthreadex’ (Windows) directly.

   - bpo-34008(53): Added ‘Py_IsInitialized’ to the list of APIs that
     are safe to call before the interpreter is initialized, and updated
     the embedding tests to cover it.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/123961

   (2) https://github.com/python/cpython/issues/124502

   (3) https://github.com/python/cpython/issues/124296

   (4) https://peps.python.org/pep-0699/

   (5) https://peps.python.org/pep-0509/

   (6) https://github.com/python/cpython/issues/124160

   (7) https://github.com/python/cpython/issues/124153

   (8) https://peps.python.org/pep-0489/

   (9) https://peps.python.org/pep-0630/

   (10) https://github.com/python/cpython/issues/124127

   (11) https://github.com/python/cpython/issues/123880

   (12) https://github.com/python/cpython/issues/123909

   (13) https://github.com/python/cpython/issues/107954

   (14) https://peps.python.org/pep-0741/

   (15) https://github.com/python/cpython/issues/107954

   (16) https://github.com/python/cpython/issues/123465

   (17) https://github.com/python/cpython/issues/100554

   (18) https://github.com/python/cpython/issues/122854

   (19) https://github.com/python/cpython/issues/122728

   (20) https://github.com/python/cpython/issues/116622

   (21) https://github.com/python/cpython/issues/105201

   (22) https://github.com/python/cpython/issues/121489

   (23) https://github.com/python/cpython/issues/121645

   (24) https://github.com/python/cpython/issues/89364

   (25) https://github.com/python/cpython/issues/113993

   (26) https://github.com/python/cpython/issues/113601

   (27) https://github.com/python/cpython/issues/112136

   (28) https://github.com/python/cpython/issues/120642

   (29) https://github.com/python/cpython/issues/120858

   (30) https://github.com/python/cpython/issues/120642

   (31) https://github.com/python/cpython/issues/120389

   (32) https://github.com/python/cpython/issues/120600

   (33) https://github.com/python/cpython/issues/70278

   (34) https://github.com/python/cpython/issues/119771

   (35) https://github.com/python/cpython/issues/119182

   (36) https://github.com/python/cpython/issues/119613

   (37) https://github.com/python/cpython/issues/119775

   (38) https://github.com/python/cpython/issues/119585

   (39) https://github.com/python/cpython/issues/119613

   (40) https://github.com/python/cpython/issues/119336

   (41) https://github.com/python/cpython/issues/119344

   (42) https://github.com/python/cpython/issues/119333

   (43) https://github.com/python/cpython/issues/119247

   (44) https://github.com/python/cpython/issues/111389

   (45) https://github.com/python/cpython/issues/118771

   (46) https://github.com/python/cpython/issues/116984

   (47) https://github.com/python/cpython/issues/118789

   (48) https://github.com/python/cpython/issues/118789

   (49) https://github.com/python/cpython/issues/117511

   (50) https://github.com/python/cpython/issues/116560

   (51) https://github.com/python/cpython/issues/97588

   (52) https://github.com/python/cpython/issues/87135

   (53) https://bugs.python.org/issue?@action=redirect&bpo=34008


File: python.info,  Node: Build<15>,  Prev: C API<15>,  Up: Python 3 14 0 alpha 1

1.24.18.25 Build
................

   - gh-125269(1): Fix detection of whether ‘-latomic’ is needed when
     cross-compiling CPython using the configure script.

   - gh-123990(2): Remove ‘WITH_FREELISTS’ macro and
     ‘--without-freelists’ build configuration

   - gh-124102(3): Update internal documentation under PCbuild, so it
     now correctly states that Windows requires VS2017 or later and
     Python 3.10 or later

   - gh-124043(4): Building using *note -with-trace-refs: 636. is
     (temporarily) disallowed when the GIL is disabled.

   - gh-123418(5): Updated Android build to use OpenSSL 3.0.15.

   - gh-123297(6): Propagate the value of ‘LDFLAGS’ to ‘LDCXXSHARED’ in
     *note sysconfig: e1.  Patch by Pablo Galindo

   - gh-121634(7): Allow for specifying the target compile triple for
     WASI.

   - gh-122578(8): Use WASI SDK 24 for testing.

   - gh-116622(9): Rename build variable ‘MODULE_LDFLAGS’ back to
     ‘LIBPYTHON’, as it’s used by package build systems (e.g.  Meson).

   - gh-118943(10): Fix an issue where the experimental JIT could be
     built several times by the ‘make regen-all’ target, leading to
     possible race conditions on heavily parallelized builds.

   - gh-121996(11): Introduce ./configure –disable-safety and
     –enable-slower-safety options.  Patch by Donghee Na.

   - gh-120522(12): Added a *note -with-app-store-compliance: 197f.
     option to patch out known issues with macOS/iOS App Store review
     processes.

   - gh-120371(13): Support WASI SDK 22 by explicitly skipping functions
     that are just stubs in wasi-libc.

   - gh-121731(14): Fix mimalloc compile error on GNU/Hurd

   - gh-121487(15): Fix deprecation warning for ATOMIC_VAR_INIT in
     mimalloc.

   - gh-121467(16): Fix a Makefile bug that prevented mimalloc header
     files from being installed.

   - gh-121103(17): On POSIX systems, excluding macOS framework
     installs, the lib directory for the free-threaded build now
     includes a «t» suffix to avoid conflicts with a co-located default
     build installation.

   - gh-120831(18): The default minimum iOS version was increased to
     13.0.

   - gh-121082(19): Fix build failure when the developer use
     ‘--enable-pystats’ arguments in configuration command after
     #118450.

   - gh-120671(20): Fix failing configure tests due to a missing space
     when appending to CFLAGS.

   - gh-120602(21): Correctly handle LLVM installs with
     ‘LLVM_VERSION_SUFFIX’ when building with
     ‘--enable-experimental-jit’.

   - gh-120688(22): On WASI in debug mode, Python is now built with
     compiler flag ‘-O3’ instead of ‘-Og’, to support more recursive
     calls.  Patch by Victor Stinner.

   - gh-118943(23): Fix a possible race condition affecting parallel
     builds configured with ‘--enable-experimental-jit’, in which *note
     FileNotFoundError: 264. could be caused by another process already
     moving ‘jit_stencils.h.new’ to ‘jit_stencils.h’.

   - gh-120326(24): On Windows, fix build error when ‘--disable-gil’ and
     ‘--experimental-jit’ options are combined.

   - gh-120291(25): Make the ‘python-config’ shell script compatible
     with non-bash shells.

   - gh-113565(26): Improve *note curses: 2f. and *note curses.panel:
     31. dependency checks in ‘configure’.

   - gh-119729(27): On POSIX systems, the pkg-config (‘.pc’) filenames
     now include the ABI flags, which may include debug («d») and
     free-threaded («t»).  For example: * ‘python-3.14.pc’ (default,
     non-debug build) * ‘python-3.14d.pc’ (default, debug build) *
     ‘python-3.14t.pc’ (free-threaded build)

   - gh-119400(28): ‘make_ssl_certs’, the script that prepares
     certificate data for the test suite, now allows specifying
     expiration dates.

   - gh-115119(29): Fall back to the bundled libmpdec if a system
     version cannot be found.

   - gh-119132(30): Update *note sys.version: 49d. to identify whether
     the build is default build or free-threading build.  Patch By
     Donghee Na.

   - gh-118836(31): Fix an ‘AssertionError’ when building with
     ‘--enable-experimental-jit’ and the compiler emits a ‘SHT_NOTE’
     section.

   - gh-118943(32): Fix a possible race condition affecting parallel
     builds configured with ‘--enable-experimental-jit’, in which
     compilation errors could be caused by an incompletely-generated
     header file.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/125269

   (2) https://github.com/python/cpython/issues/123990

   (3) https://github.com/python/cpython/issues/124102

   (4) https://github.com/python/cpython/issues/124043

   (5) https://github.com/python/cpython/issues/123418

   (6) https://github.com/python/cpython/issues/123297

   (7) https://github.com/python/cpython/issues/121634

   (8) https://github.com/python/cpython/issues/122578

   (9) https://github.com/python/cpython/issues/116622

   (10) https://github.com/python/cpython/issues/118943

   (11) https://github.com/python/cpython/issues/121996

   (12) https://github.com/python/cpython/issues/120522

   (13) https://github.com/python/cpython/issues/120371

   (14) https://github.com/python/cpython/issues/121731

   (15) https://github.com/python/cpython/issues/121487

   (16) https://github.com/python/cpython/issues/121467

   (17) https://github.com/python/cpython/issues/121103

   (18) https://github.com/python/cpython/issues/120831

   (19) https://github.com/python/cpython/issues/121082

   (20) https://github.com/python/cpython/issues/120671

   (21) https://github.com/python/cpython/issues/120602

   (22) https://github.com/python/cpython/issues/120688

   (23) https://github.com/python/cpython/issues/118943

   (24) https://github.com/python/cpython/issues/120326

   (25) https://github.com/python/cpython/issues/120291

   (26) https://github.com/python/cpython/issues/113565

   (27) https://github.com/python/cpython/issues/119729

   (28) https://github.com/python/cpython/issues/119400

   (29) https://github.com/python/cpython/issues/115119

   (30) https://github.com/python/cpython/issues/119132

   (31) https://github.com/python/cpython/issues/118836

   (32) https://github.com/python/cpython/issues/118943


File: python.info,  Node: Python 3 13 0 beta 1,  Next: Python 3 13 0 alpha 6,  Prev: Python 3 14 0 alpha 1,  Up: Changelog

1.24.19 Python 3.13.0 beta 1
----------------------------

'Release date: 2024-05-08'

* Menu:

* Security: Security<17>.
* Core and Builtins: Core and Builtins<48>.
* Library: Library<53>.
* Core and Builtins: Core and Builtins<49>.
* Library: Library<54>.
* Documentation: Documentation<14>.
* Build: Build<16>.
* Windows: Windows<14>.
* macOS: macOS<8>.
* IDLE: IDLE<8>.
* C API: C API<16>.


File: python.info,  Node: Security<17>,  Next: Core and Builtins<48>,  Up: Python 3 13 0 beta 1

1.24.19.1 Security
..................

   - gh-116741(1): Update bundled libexpat to 2.6.2

   - gh-117233(2): Detect BLAKE2, SHA3, Shake, & truncated SHA512
     support in the OpenSSL-ish libcrypto library at build time.  This
     allows *note hashlib: 6c. to be used with libraries that do not to
     support every algorithm that upstream OpenSSL does.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116741

   (2) https://github.com/python/cpython/issues/117233


File: python.info,  Node: Core and Builtins<48>,  Next: Library<53>,  Prev: Security<17>,  Up: Python 3 13 0 beta 1

1.24.19.2 Core and Builtins
...........................

   - gh-118414(1): Add instrumented opcodes to YIELD_VALUE assertion for
     tracing cases.

   - gh-117953(2): When a builtin or extension module is imported for
     the first time, while a subinterpreter is active, the module’s init
     function is now run by the main interpreter first before import
     continues in the subinterpreter.  Consequently, single-phase init
     modules now fail in an isolated subinterpreter without the init
     function running under that interpreter, whereas before it would
     run under the subinterpreter 'before' failing, potentially leaving
     behind global state and callbacks and otherwise leaving the module
     in an inconsistent state.

   - gh-117549(3): Don’t use designated initializer syntax in inline
     functions in internal headers.  They cause problems for C++ or MSVC
     users who aren’t yet using the latest C++ standard (C++20).  While
     internal, pycore_backoff.h, is included (indirectly, via
     pycore_code.h) by some key 3rd party software that does so for
     speed.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118414

   (2) https://github.com/python/cpython/issues/117953

   (3) https://github.com/python/cpython/issues/117549


File: python.info,  Node: Library<53>,  Next: Core and Builtins<49>,  Prev: Core and Builtins<48>,  Up: Python 3 13 0 beta 1

1.24.19.3 Library
.................

   - gh-95382(1): Improve performance of *note json.dumps(): f43. and
     *note json.dump(): f42. when using the argument 'indent'.
     Depending on the data the encoding using *note json.dumps(): f43.
     with 'indent' can be up to 2 to 3 times faster.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/95382


File: python.info,  Node: Core and Builtins<49>,  Next: Library<54>,  Prev: Library<53>,  Up: Python 3 13 0 beta 1

1.24.19.4 Core and Builtins
...........................

   - gh-116322(1): In ‘--disable-gil’ builds, the GIL will be enabled
     while loading C extension modules.  If the module indicates that it
     supports running without the GIL, the GIL will be disabled once
     loading is complete.  Otherwise, the GIL will remain enabled for
     the remainder of the interpreter’s lifetime.  This behavior does
     not apply if the GIL has been explicitly enabled or disabled with
     ‘PYTHON_GIL’ or ‘-Xgil’.

   - gh-118513(2): Fix incorrect *note UnboundLocalError: 173d. when two
     comprehensions in the same function both reference the same name,
     and in one comprehension the name is bound while in the other it’s
     an implicit global.

   - gh-118518(3): Allow the Linux perf support to work without frame
     pointers using perf’s advanced JIT support.  The feature is
     activated when using the ‘PYTHON_PERF_JIT_SUPPORT’ environment
     variable or when running Python with ‘-Xperf_jit’.  Patch by Pablo
     Galindo.

   - gh-117514(4): Add ‘sys._is_gil_enabled()’ function that returns
     whether the GIL is currently enabled.  In the default build it
     always returns ‘True’ because the GIL is always enabled.  In the
     free-threaded build, it may return ‘True’ or ‘False’.

   - gh-118164(5): Break a loop between the Python implementation of the
     *note decimal: 3a. module and the Python code for integer to string
     conversion.  Also optimize integer to string conversion for values
     in the range from 9_000 to 135_000 decimal digits.

   - gh-118473(6): Fix *note sys.set_asyncgen_hooks(): 1985. not to be
     partially set when raising *note TypeError: 198.

   - gh-118465(7): Compiler populates the new ‘__firstlineno__’ field on
     a class with the line number of the first line of the class
     definition.

   - gh-118492(8): Fix an issue where the type cache can expose a
     previously accessed attribute when a finalizer is run.

   - gh-117714(9): update ‘async_generator.athrow().close()’ and
     ‘async_generator.asend().close()’ to close their section of the
     underlying async generator

   - gh-111201(10): The *note interactive: 1b5. interpreter is now
     implemented in Python, which allows for a number of new features
     like colors, multiline input, history viewing, and paste mode.
     Contributed by Pablo Galindo, Łukasz Langa and Lysandros Nikolaou
     based on code from the PyPy project.

   - gh-74929(11): Implement PEP 667: converted *note
     FrameType.f_locals: 4a6. and *note PyFrame_GetLocals(): 661. to
     return a write-through proxy object when the frame refers to a
     function or comprehension.

   - gh-116767(12): Fix crash in compiler on “async with” that has many
     context managers.

   - gh-118335(13): Change how to use the tier 2 interpreter.  Instead
     of running Python with ‘-X uops’ or setting the environment
     variable ‘PYTHON_UOPS=1’, this choice is now made at build time by
     configuring with ‘--enable-experimental-jit=interpreter’.

     'Beware!'  This changes the environment variable to enable or
     disable micro-ops to ‘PYTHON_JIT’.  The old ‘PYTHON_UOPS’ is no
     longer used.

   - gh-118306(14): Update JIT compilation to use LLVM 18

   - gh-118160(15): *note Annotation scopes: 4ac. within classes can now
     contain comprehensions.  However, such comprehensions are not
     inlined into their parent scope at runtime.  Patch by Jelle
     Zijlstra.

   - gh-118272(16): Fix bug where ‘generator.close’ does not free the
     generator frame’s locals.

   - gh-118216(17): Don’t consider *note __future__: 0. imports with
     dots before the module name.

   - gh-118074(18): Make sure that the Executor objects in the
     COLD_EXITS array aren’t assumed to be GC-able (which would access
     bytes outside the object).

   - gh-107674(19): Lazy load frame line number to improve performance
     of tracing

   - gh-118082(20): Improve *note SyntaxError: 18e. message for imports
     without names, like in ‘from x import’ and ‘import’ cases.  It now
     points out to users that *note import: 7f9. expects at least one
     name after it.

   - gh-118090(21): Improve *note SyntaxError: 18e. message for empty
     type param brackets.

   - gh-117958(22): Added a ‘get_jit_code()’ method to access JIT
     compiled machine code from the UOp Executor when the experimental
     JIT is enabled.  Patch by Anthony Shaw.

   - gh-117901(23): Add option for compiler’s codegen to save nested
     instruction sequences for introspection.

   - gh-116622(24): Redirect stdout and stderr to system log when
     embedded in an Android app.

   - gh-109118(25): *note annotation scope: 4ac. within class scopes can
     now contain lambdas.

   - gh-117894(26): Prevent ‘agen.aclose()’ objects being re-used after
     ‘.throw()’.

   - gh-117881(27): prevent concurrent access to an async generator via
     athrow().throw() or asend().throw()

   - gh-117536(28): Fix a *note RuntimeWarning: 4d8. when calling
     ‘agen.aclose().throw(Exception)’.

   - gh-117755(29): Fix mimalloc allocator for huge memory allocation
     (around 8,589,934,592 GiB) on s390x.  Patch by Victor Stinner.

   - gh-117750(30): Fix issue where an object’s dict would get out of
     sync with the object’s internal values when being cleared.
     ‘obj.__dict__.clear()’ now clears the internal values, but leaves
     the dict attached to the object.

   - gh-117431(31): Improve the performance of the following *note
     bytes: 192. and *note bytearray: 344. methods by adapting them to
     the *note METH_FASTCALL: 1986. calling convention:

        * ‘count()’

        * ‘find()’

        * ‘index()’

        * ‘rfind()’

        * ‘rindex()’

   - gh-117709(32): Speed up calls to *note str(): 169. with
     positional-only argument, by using the PEP 590(33) ‘vectorcall’
     calling convention.  Patch by Erlend Aasland.

   - gh-117680(34): Give ‘_PyInstructionSequence’ a Python interface and
     use it in tests.

   - gh-115776(35): Statically allocated objects are, by definition,
     immortal so must be marked as such regardless of whether they are
     in extension modules or not.

   - gh-117385(36): Remove unhandled ‘PY_MONITORING_EVENT_BRANCH’ and
     ‘PY_MONITORING_EVENT_EXCEPTION_HANDLED’ events from *note
     sys.settrace(): 2e1.

   - gh-116322(37): Extension modules may indicate to the runtime that
     they can run without the GIL. Multi-phase init modules do so by
     calling providing ‘Py_MOD_GIL_NOT_USED’ for the ‘Py_mod_gil’ slot,
     while single-phase init modules call ‘PyUnstable_Module_SetGIL(mod,
     Py_MOD_GIL_NOT_USED)’ from their init function.

   - gh-116129(38): Implement PEP 696(39), adding support for defaults
     on type parameters.  Patch by Jelle Zijlstra.

   - gh-93502(40): Add two new functions to the C-API, *note
     PyRefTracer_SetTracer(): 610. and *note PyRefTracer_GetTracer():
     611, that allows to track object creation and destruction the same
     way the *note tracemalloc: 105. module does.  Patch by Pablo
     Galindo

   - gh-107674(41): Improved the performance of *note sys.settrace():
     2e1. significantly

   - gh-95754(42): Improve the error message when a script shadowing a
     module from the standard library causes *note AttributeError: 5f0.
     to be raised.  Similarly, improve the error message when a script
     shadowing a third party module attempts to access an attribute from
     that third party module while still initialising.

   - gh-99180(43): Elide uninformative traceback indicators in ‘return’
     and simple ‘assignment’ statements.  Patch by Pablo Galindo.

   - gh-105879(44): Allow the 'globals' and 'locals' arguments to *note
     exec(): 4a3. and *note eval(): 4a4. to be passed as keywords.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116322

   (2) https://github.com/python/cpython/issues/118513

   (3) https://github.com/python/cpython/issues/118518

   (4) https://github.com/python/cpython/issues/117514

   (5) https://github.com/python/cpython/issues/118164

   (6) https://github.com/python/cpython/issues/118473

   (7) https://github.com/python/cpython/issues/118465

   (8) https://github.com/python/cpython/issues/118492

   (9) https://github.com/python/cpython/issues/117714

   (10) https://github.com/python/cpython/issues/111201

   (11) https://github.com/python/cpython/issues/74929

   (12) https://github.com/python/cpython/issues/116767

   (13) https://github.com/python/cpython/issues/118335

   (14) https://github.com/python/cpython/issues/118306

   (15) https://github.com/python/cpython/issues/118160

   (16) https://github.com/python/cpython/issues/118272

   (17) https://github.com/python/cpython/issues/118216

   (18) https://github.com/python/cpython/issues/118074

   (19) https://github.com/python/cpython/issues/107674

   (20) https://github.com/python/cpython/issues/118082

   (21) https://github.com/python/cpython/issues/118090

   (22) https://github.com/python/cpython/issues/117958

   (23) https://github.com/python/cpython/issues/117901

   (24) https://github.com/python/cpython/issues/116622

   (25) https://github.com/python/cpython/issues/109118

   (26) https://github.com/python/cpython/issues/117894

   (27) https://github.com/python/cpython/issues/117881

   (28) https://github.com/python/cpython/issues/117536

   (29) https://github.com/python/cpython/issues/117755

   (30) https://github.com/python/cpython/issues/117750

   (31) https://github.com/python/cpython/issues/117431

   (32) https://github.com/python/cpython/issues/117709

   (33) https://peps.python.org/pep-0590/

   (34) https://github.com/python/cpython/issues/117680

   (35) https://github.com/python/cpython/issues/115776

   (36) https://github.com/python/cpython/issues/117385

   (37) https://github.com/python/cpython/issues/116322

   (38) https://github.com/python/cpython/issues/116129

   (39) https://peps.python.org/pep-0696/

   (40) https://github.com/python/cpython/issues/93502

   (41) https://github.com/python/cpython/issues/107674

   (42) https://github.com/python/cpython/issues/95754

   (43) https://github.com/python/cpython/issues/99180

   (44) https://github.com/python/cpython/issues/105879


File: python.info,  Node: Library<54>,  Next: Documentation<14>,  Prev: Core and Builtins<49>,  Up: Python 3 13 0 beta 1

1.24.19.5 Library
.................

   - gh-118418(1): A *note DeprecationWarning: 1a3. is now emitted if
     you fail to pass a value to the new 'type_params' parameter of
     ‘typing._eval_type()’ or ‘typing.ForwardRef._evaluate()’.  (Using
     either of these private and undocumented functions is discouraged
     to begin with, but failing to pass a value to the ‘type_params’
     parameter may lead to incorrect behaviour on Python 3.12 or newer.)

   - gh-118660(2): Add an optional second type parameter to *note
     typing.ContextManager: e8d. and *note typing.AsyncContextManager:
     1988, representing the return types of *note __exit__(): 1508. and
     *note __aexit__(): 1989. respectively.  This parameter defaults to
     ‘bool | None’.

   - gh-118650(3): The ‘enum’ module allows method named ‘_repr_*’ to be
     defined on ‘Enum’ types.

   - gh-118648(4): Add type parameter defaults to *note
     typing.Generator: 198a. and *note typing.AsyncGenerator: 198b.

   - gh-101137(5): Mime type ‘text/x-rst’ is now supported by *note
     mimetypes: 93.

   - gh-118164(6): The Python implementation of the ‘decimal’ module
     could appear to hang in relatively small power cases (like
     ‘2**117’) if context precision was set to a very high value.  A
     different method to check for exactly representable results is used
     now that doesn’t rely on computing ‘10**precision’ (which could be
     effectively too large to compute).

   - gh-111744(7): ‘breakpoint()’ and ‘pdb.set_trace()’ now enter the
     debugger immediately after the call rather than before the next
     line is executed.

   - gh-118500(8): Add *note pdb: aa. support for zipapps

   - gh-118406(9): Add signature for *note sqlite3.Connection: 54e.
     objects.

   - gh-101732(10): Use a Y2038 compatible openssl time function when
     available.

   - gh-118404(11): Fix *note inspect.signature(): 22f. for
     non-comparable callables.

   - gh-118402(12): Fix *note inspect.signature(): 22f. for the result
     of the *note functools.cmp_to_key(): 13e2. call.

   - gh-116622(13): On Android, *note sysconfig.get_platform: 144a. now
     returns the format specified by PEP 738(14).

   - gh-118285(15): Allow to specify the signature of custom callable
     instances of extension type by the ‘__text_signature__’ attribute.
     Specify signatures of *note operator.attrgetter: 1035, *note
     operator.itemgetter: c59, and *note operator.methodcaller: 1036.
     instances.

   - gh-118314(16): Fix an edge case in *note binascii.a2b_base64():
     198c. strict mode, where excessive padding is not detected when no
     padding is necessary.

   - gh-118271(17): Add the ‘PhotoImage’ methods ‘read()’ to read an
     image from a file and ‘data()’ to get the image data.  Add
     'background' and 'grayscale' parameters to ‘PhotoImage’ method
     ‘write()’.

   - gh-118225(18): Add the ‘PhotoImage’ method ‘copy_replace()’ to copy
     a region from one image to other image, possibly with pixel zooming
     and/or subsampling.  Add 'from_coords' parameter to ‘PhotoImage’
     methods ‘copy()’, ‘zoom()’ and ‘subsample()’.  Add 'zoom' and
     'subsample' parameters to ‘PhotoImage’ method ‘copy()’.

   - gh-118221(19): Fix a bug where *note sqlite3.Connection.iterdump():
     550. could fail if a custom *note row factory: 198d. was used.
     Patch by Erlend Aasland.

   - gh-118013(20): Fix regression introduced in gh-103193(21) that
     meant that calling *note inspect.getattr_static(): 6bd. on an
     instance would cause a strong reference to that instance’s class to
     persist in an internal cache in the *note inspect: 82. module.
     This caused unexpected memory consumption if the class was
     dynamically created, the class held strong references to other
     objects which took up a significant amount of memory, and the cache
     contained the sole strong reference to the class.  The fix for the
     regression leads to a slowdown in ‘getattr_static()’, but the
     function should still be significantly faster than it was in Python
     3.11.  Patch by Alex Waygood.

   - gh-118218(22): Speed up *note itertools.pairwise(): a18. in the
     common case by up to 1.8x.

   - gh-117486(23): Improve the behavior of user-defined subclasses of
     *note ast.AST: 4c4.  Such classes will now require no changes in
     the usual case to conform with the behavior changes of the *note
     ast: 9. module in Python 3.13.  Patch by Jelle Zijlstra.

   - gh-90848(24): Fixed *note unittest.mock.create_autospec(): 191c. to
     configure parent mock with keyword arguments.

   - gh-118168(25): Fix incorrect argument substitution when *note
     typing.Unpack: 198e. is used with the builtin *note tuple: 614.
     ‘typing.Unpack’ now raises *note TypeError: 198. when used with
     certain invalid types.  Patch by Jelle Zijlstra.

   - gh-118131(26): Add command-line interface for the *note random: bd.
     module.  Patch by Hugo van Kemenade.

   - gh-118107(27): Fix *note zipimport: 138. reading of ZIP64 files
     with file entries that are too big or offset too far.

   - gh-102511(28): Fix *note os.path.normpath(): 1521. for UNC paths on
     Windows.  Speed up *note os.path.splitroot(): 6cc. with a native
     implementation.

   - gh-117535(29): Change the unknown filename of *note warnings: 118.
     from ‘sys’ to ‘<sys>’ to clarify that it’s not a real filename.

   - gh-114053(30): Fix erroneous *note NameError: 452. when calling
     *note typing.get_type_hints(): 8c1. on a class that made use of PEP
     695(31) type parameters in a module that had ‘from __future__
     import annotations’ at the top of the file.  Patch by Alex Waygood.

   - gh-116931(32): Add parameter 'fileobj' check for *note
     tarfile.TarFile.addfile(): 198f.

   - gh-117995(33): Don’t raise *note DeprecationWarning: 1a3. when a
     *note sequence: 717. of parameters is used to bind indexed,
     nameless placeholders.  See also gh-100668(34).

   - gh-80361(35): Fix TypeError in *note
     email.message.Message.get_payload(): 13d5. when the charset is RFC
     2231(36) encoded.

   - gh-86650(37): Fix IndexError when parse some emails with invalid
     Message-ID (including one-off addresses generated by Microsoft
     Outlook).

   - gh-117691(38): Improve the error messages emitted by *note tarfile:
     e4. deprecation warnings relating to PEP 706.  If a ‘filter’
     argument is not provided to ‘extract()’ or ‘extractall’, the
     deprecation warning now points to the line in the user’s code where
     the relevant function was called.  Patch by Alex Waygood.

   - gh-115874(39): Fixed a possible segfault during garbage collection
     of ‘_asyncio.FutureIter’ objects.  Patch by Savannah Ostrowski.

   - gh-115060(40): Speed up *note pathlib.Path.glob(): 538. by omitting
     an initial *note is_dir(): 53b. call.  As a result of this change,
     *note glob(): 538. can no longer raise *note OSError: 2c0.

   - gh-77102(41): *note site: cc. module now parses ‘.pth’ file with
     UTF-8 first, and *note locale encoding: 54b. if
     ‘UnicodeDecodeError’ happened.  It supported only locale encoding
     before.

   - gh-76785(42): We’ve exposed the low-level ‘_interpreters’ module
     for the sake of the PyPI implementation of PEP 734(43).  It was
     sometimes available as the ‘_xxsubinterpreters’ module and was
     formerly used only for testing.  For the most part, it should be
     considered an internal module, like ‘_thread’ and ‘_imp’.  See
     ‘https://discuss.python.org/t/pep-734-multiple-interpreters-in-the-stdlib/41147/26’.

   - gh-115060(44): Speed up *note pathlib.Path.glob(): 538. by not
     scanning directories for non-wildcard pattern segments.

   - gh-117727(45): Speed up *note pathlib.Path.iterdir(): 26e. by using
     *note os.scandir(): c56. internally.

   - gh-117586(46): Speed up *note pathlib.Path.walk(): 6d0. by working
     with strings internally.

   - gh-117722(47): Change the new multi-separator support in *note
     asyncio.StreamReader.readuntil(): 4d1. to only accept tuples of
     separators rather than arbitrary iterables.

   - gh-117692(48): Fixes a bug when *note doctest.DocTestFinder: 1990.
     was failing on wrapped ‘builtin_function_or_method’.

   - gh-117348(49): Largely restored import time performance of
     configparser by avoiding dataclasses.

   - gh-117641(50): Speedup *note os.path.commonpath(): 103f. on Unix.

   - gh-117663(51): Fix ‘_simple_enum’ to detect aliases when multiple
     arguments are present but only one is the member value.

   - gh-117636(52): Speedup *note os.path.join(): 1991.

   - gh-117618(53): Support ‘package.module’ as ‘filename’ for ‘break’
     command of *note pdb: aa.

   - gh-102247(54): the status codes enum with constants in
     http.HTTPStatus are updated to include the names from RFC9110.
     This RFC includes some HTTP statuses previously only used for
     WEBDAV and assigns more generic names to them.

     The old constants are preserved for backwards compatibility.

   - gh-117607(55): Speedup *note os.path.relpath(): 6d2.

   - gh-117586(56): Speed up *note pathlib.Path.glob(): 538. by working
     with strings internally.

   - gh-117225(57): Add colour to doctest output.  Patch by Hugo van
     Kemenade.

   - gh-117566(58): *note ipaddress.IPv6Address.is_loopback(): 1992.
     will now return ‘True’ for IPv4-mapped loopback addresses, i.e.
     addresses in the ‘::ffff:127.0.0.0/104’ address space.

   - gh-117546(59): Fix issue where *note os.path.realpath(): 262.
     stopped resolving symlinks after encountering a symlink loop on
     POSIX.

   - gh-116720(60): Improved behavior of *note asyncio.TaskGroup: 4d2.
     when an external cancellation collides with an internal
     cancellation.  For example, when two task groups are nested and
     both experience an exception in a child task simultaneously, it was
     possible that the outer task group would misbehave, because its
     internal cancellation was swallowed by the inner task group.

     In the case where a task group is cancelled externally and also
     must raise an *note ExceptionGroup: 4d3, it will now call the
     parent task’s *note cancel(): 4d4. method.  This ensures that a
     *note asyncio.CancelledError: 4d5. will be raised at the next *note
     await: 18d, so the cancellation is not lost.

     An added benefit of these changes is that task groups now preserve
     the cancellation count (*note asyncio.Task.cancelling(): 4d6.).

     In order to handle some corner cases, *note
     asyncio.Task.uncancel(): 4d7. may now reset the undocumented
     ‘_must_cancel’ flag when the cancellation count reaches zero.

   - gh-117516(61): Add *note typing.TypeIs: 48c, implementing PEP
     742(62).  Patch by Jelle Zijlstra.

   - gh-117503(63): Fix support of non-ASCII user names in bytes paths
     in *note os.path.expanduser(): c0b. on Posix.

   - gh-117394(64): *note os.path.ismount(): c09. is now 2-3 times
     faster if the user has permissions.

   - gh-117313(65): Only treat ‘'\n'’, ‘'\r'’ and ‘'\r\n'’ as line
     separators in re-folding the *note email: 3f. messages.  Preserve
     control characters ‘'\v'’, ‘'\f'’, ‘'\x1c'’, ‘'\x1d'’ and ‘'\x1e'’
     and Unicode line separators ‘'\x85'’, ‘'\u2028'’ and ‘'\u2029'’ as
     is.

   - gh-117142(66): Convert ‘_ctypes’ to multi-phase initialisation (
     PEP 489(67)).

   - gh-66543(68): Add the *note mimetypes.guess_file_type(): 517.
     function which works with file path.  Passing file path instead of
     URL in *note guess_type(): 518. is *note soft deprecated: 23d.

   - gh-68583(69): webbrowser CLI: replace getopt with argparse, add
     long options.  Patch by Hugo van Kemenade.

   - gh-116871(70): Name suggestions for *note AttributeError: 5f0. and
     *note ImportError: 65b. now only include underscored names if the
     original name was underscored.

   - gh-116023(71): Don’t show empty fields (value ‘None’ or ‘[]’) in
     *note ast.dump(): ae3. by default.  Add ‘show_empty=False’
     parameter to optionally show them.

   - gh-115961(72): Added ‘name’ and ‘mode’ attributes for compressed
     and archived file-like objects in modules *note bz2: 14, *note
     lzma: 8e, *note tarfile: e4. and *note zipfile: 137.  The value of
     the ‘mode’ attribute of *note gzip.GzipFile: 65c. was changed from
     integer (‘1’ or ‘2’) to string (‘'rb'’ or ‘'wb'’).  The value of
     the ‘mode’ attribute of the readable file-like object returned by
     *note zipfile.ZipFile.open(): 65d. was changed from ‘'r'’ to
     ‘'rb'’.

   - gh-82062(73): Fix *note inspect.signature(): 22f. to correctly
     handle parameter defaults on methods in extension modules that use
     names defined in the module namespace.

   - gh-83856(74): Honor *note atexit: d. for all *note multiprocessing:
     98. start methods

   - gh-113081(75): Print colorized exception just like built-in
     traceback in *note pdb: aa.

   - gh-112855(76): Speed up pickling of *note pathlib.PurePath: 6ce.
     objects.  Patch by Barney Gale.

   - gh-111744(77): Support opcode events in *note bdb: 10.

   - gh-109617(78): ‘ncurses’: fixed a crash that could occur on macOS
     13 or earlier when Python was built with Apple Xcode 15’s SDK.

   - gh-83151(79): Enabled arbitrary statements and evaluations in *note
     pdb: aa. shell to access the local variables of the current frame,
     which made it possible for multi-scope code like generators or
     nested function to work.

   - gh-110209(80): Add *note __class_getitem__(): 944. to *note
     types.GeneratorType: 1993. and *note types.CoroutineType: 108b. for
     type hinting purposes.  Patch by James Hilton-Balfe.

   - gh-108191(81): The *note types.SimpleNamespace: 4e6. now accepts an
     optional positional argument which specifies initial values of
     attributes as a dict or an iterable of key-value pairs.

   - gh-62090(82): Fix assertion errors caused by whitespace in metavars
     or ‘SUPPRESS’-ed groups in *note argparse: 7. by simplifying usage
     formatting.  Patch by Ali Hamdan.

   - gh-102402(83): Adjust ‘logging.LogRecord’ to use ‘time.time_ns()’
     and fix minor bug related to floating-point math.

   - gh-100242(84): Bring pure Python implementation
     ‘functools.partial.__new__’ more in line with the C-implementation
     by not just always checking for the presence of the attribute
     ‘'func'’ on the first argument of ‘partial’.  Instead, both the
     Python version and the C version perform an ‘isinstance(func,
     partial)’ check on the first argument of ‘partial’.

   - gh-99730(85): HEAD requests are no longer upgraded to GET request
     during redirects in urllib.

   - gh-66410(86): Setting the ‘tkinter’ module global ‘wantobjects’ to
     ‘2’ before creating the *note Tk: 1994. object or call the
     ‘wantobjects()’ method of the ‘Tk’ object with argument ‘2’ makes
     now arguments to callbacks registered in the *note tkinter: f6.
     module to be passed as various Python objects (‘int’, ‘float’,
     ‘bytes’, ‘tuple’), depending on their internal representation in
     Tcl, instead of always ‘str’.  ‘tkinter.wantobjects’ is now set to
     ‘2’ by default.

   - bpo-40943(87): Fix several IndexError when parse emails with
     truncated Message-ID, address, routes, etc, e.g.  ‘example@’.

   - bpo-39324(88): Add mime type mapping for .md <-> text/markdown

   - bpo-18108(89): *note shutil.chown(): 549. now supports 'dir_fd' and
     'follow_symlinks' keyword arguments.

   - bpo-30988(90): Fix parsing of emails with invalid address headers
     having a leading or trailing dot.  Patch by tsufeki.

   - bpo-32839(91): Add the ‘after_info()’ method for Tkinter widgets.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118418

   (2) https://github.com/python/cpython/issues/118660

   (3) https://github.com/python/cpython/issues/118650

   (4) https://github.com/python/cpython/issues/118648

   (5) https://github.com/python/cpython/issues/101137

   (6) https://github.com/python/cpython/issues/118164

   (7) https://github.com/python/cpython/issues/111744

   (8) https://github.com/python/cpython/issues/118500

   (9) https://github.com/python/cpython/issues/118406

   (10) https://github.com/python/cpython/issues/101732

   (11) https://github.com/python/cpython/issues/118404

   (12) https://github.com/python/cpython/issues/118402

   (13) https://github.com/python/cpython/issues/116622

   (14) https://peps.python.org/pep-0738/

   (15) https://github.com/python/cpython/issues/118285

   (16) https://github.com/python/cpython/issues/118314

   (17) https://github.com/python/cpython/issues/118271

   (18) https://github.com/python/cpython/issues/118225

   (19) https://github.com/python/cpython/issues/118221

   (20) https://github.com/python/cpython/issues/118013

   (21) https://github.com/python/cpython/issues/103193

   (22) https://github.com/python/cpython/issues/118218

   (23) https://github.com/python/cpython/issues/117486

   (24) https://github.com/python/cpython/issues/90848

   (25) https://github.com/python/cpython/issues/118168

   (26) https://github.com/python/cpython/issues/118131

   (27) https://github.com/python/cpython/issues/118107

   (28) https://github.com/python/cpython/issues/102511

   (29) https://github.com/python/cpython/issues/117535

   (30) https://github.com/python/cpython/issues/114053

   (31) https://peps.python.org/pep-0695/

   (32) https://github.com/python/cpython/issues/116931

   (33) https://github.com/python/cpython/issues/117995

   (34) https://github.com/python/cpython/issues/100668

   (35) https://github.com/python/cpython/issues/80361

   (36) https://datatracker.ietf.org/doc/html/rfc2231.html

   (37) https://github.com/python/cpython/issues/86650

   (38) https://github.com/python/cpython/issues/117691

   (39) https://github.com/python/cpython/issues/115874

   (40) https://github.com/python/cpython/issues/115060

   (41) https://github.com/python/cpython/issues/77102

   (42) https://github.com/python/cpython/issues/76785

   (43) https://peps.python.org/pep-0734/

   (44) https://github.com/python/cpython/issues/115060

   (45) https://github.com/python/cpython/issues/117727

   (46) https://github.com/python/cpython/issues/117586

   (47) https://github.com/python/cpython/issues/117722

   (48) https://github.com/python/cpython/issues/117692

   (49) https://github.com/python/cpython/issues/117348

   (50) https://github.com/python/cpython/issues/117641

   (51) https://github.com/python/cpython/issues/117663

   (52) https://github.com/python/cpython/issues/117636

   (53) https://github.com/python/cpython/issues/117618

   (54) https://github.com/python/cpython/issues/102247

   (55) https://github.com/python/cpython/issues/117607

   (56) https://github.com/python/cpython/issues/117586

   (57) https://github.com/python/cpython/issues/117225

   (58) https://github.com/python/cpython/issues/117566

   (59) https://github.com/python/cpython/issues/117546

   (60) https://github.com/python/cpython/issues/116720

   (61) https://github.com/python/cpython/issues/117516

   (62) https://peps.python.org/pep-0742/

   (63) https://github.com/python/cpython/issues/117503

   (64) https://github.com/python/cpython/issues/117394

   (65) https://github.com/python/cpython/issues/117313

   (66) https://github.com/python/cpython/issues/117142

   (67) https://peps.python.org/pep-0489/

   (68) https://github.com/python/cpython/issues/66543

   (69) https://github.com/python/cpython/issues/68583

   (70) https://github.com/python/cpython/issues/116871

   (71) https://github.com/python/cpython/issues/116023

   (72) https://github.com/python/cpython/issues/115961

   (73) https://github.com/python/cpython/issues/82062

   (74) https://github.com/python/cpython/issues/83856

   (75) https://github.com/python/cpython/issues/113081

   (76) https://github.com/python/cpython/issues/112855

   (77) https://github.com/python/cpython/issues/111744

   (78) https://github.com/python/cpython/issues/109617

   (79) https://github.com/python/cpython/issues/83151

   (80) https://github.com/python/cpython/issues/110209

   (81) https://github.com/python/cpython/issues/108191

   (82) https://github.com/python/cpython/issues/62090

   (83) https://github.com/python/cpython/issues/102402

   (84) https://github.com/python/cpython/issues/100242

   (85) https://github.com/python/cpython/issues/99730

   (86) https://github.com/python/cpython/issues/66410

   (87) https://bugs.python.org/issue?@action=redirect&bpo=40943

   (88) https://bugs.python.org/issue?@action=redirect&bpo=39324

   (89) https://bugs.python.org/issue?@action=redirect&bpo=18108

   (90) https://bugs.python.org/issue?@action=redirect&bpo=30988

   (91) https://bugs.python.org/issue?@action=redirect&bpo=32839


File: python.info,  Node: Documentation<14>,  Next: Build<16>,  Prev: Library<54>,  Up: Python 3 13 0 beta 1

1.24.19.6 Documentation
.......................

   - gh-117928(1): The minimum Sphinx version required for the
     documentation is now 6.2.1.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/117928


File: python.info,  Node: Build<16>,  Next: Windows<14>,  Prev: Documentation<14>,  Up: Python 3 13 0 beta 1

1.24.19.7 Build
...............

   - gh-118734(1): Fixes Windows build when invoked directly (not
     through the ‘build.bat’ script) without specifying a value for
     ‘UseTIER2’.

   - gh-115119(2): The ‘configure’ option *note -with-system-libmpdec:
     657. now defaults to ‘yes’.  The bundled copy of ‘libmpdecimal’
     will be removed in Python 3.15.

   - gh-117845(3): Fix building against recent libedit versions by
     detecting readline hook signatures in ‘configure’.

   - gh-116622(4): A testbed project was added to run the test suite on
     Android.

   - gh-117645(5): Increase WASI stack size from 512 KiB to 8 MiB and
     the initial memory from 10 MiB to 20 MiB. Patch by Victor Stinner.

   - gh-115119(6): ‘configure’ now uses ‘pkg-config’ to detect *note
     decimal: 3a. dependencies if the *note -with-system-libmpdec: 657.
     option is given.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118734

   (2) https://github.com/python/cpython/issues/115119

   (3) https://github.com/python/cpython/issues/117845

   (4) https://github.com/python/cpython/issues/116622

   (5) https://github.com/python/cpython/issues/117645

   (6) https://github.com/python/cpython/issues/115119


File: python.info,  Node: Windows<14>,  Next: macOS<8>,  Prev: Build<16>,  Up: Python 3 13 0 beta 1

1.24.19.8 Windows
.................

   - gh-115119(1): Update Windows installer to use libmpdecimal 4.0.0.

   - gh-118486(2): *note os.mkdir(): 52c. now accepts 'mode' of ‘0o700’
     to restrict the new directory to the current user.

   - gh-118347(3): Fixes launcher updates not being installed.

   - gh-118293(4): The ‘multiprocessing’ module now passes the
     ‘STARTF_FORCEOFFFEEDBACK’ flag when spawning processes to tell
     Windows not to change the mouse cursor.

   - gh-115009(5): Update Windows installer to use SQLite 3.45.3.

   - gh-90329(6): Suppress the warning displayed on virtual environment
     creation when the requested and created paths differ only by a
     short (8.3 style) name.  Warnings will continue to be shown if a
     junction or symlink in the path caused the venv to be created in a
     different location than originally requested.

   - gh-117786(7): Fixes virtual environments not correctly launching
     when created from a Store install.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115119

   (2) https://github.com/python/cpython/issues/118486

   (3) https://github.com/python/cpython/issues/118347

   (4) https://github.com/python/cpython/issues/118293

   (5) https://github.com/python/cpython/issues/115009

   (6) https://github.com/python/cpython/issues/90329

   (7) https://github.com/python/cpython/issues/117786


File: python.info,  Node: macOS<8>,  Next: IDLE<8>,  Prev: Windows<14>,  Up: Python 3 13 0 beta 1

1.24.19.9 macOS
...............

   - gh-115119(1): Update macOS installer to use libmpdecimal 4.0.0.

   - gh-114099(2): iOS preprocessor symbol usage was made compatible
     with older macOS SDKs.

   - gh-115009(3): Update macOS installer to use SQLite 3.45.3.

   - gh-91629(4): Use ‘~/.config/fish/conf.d’ configs and
     ‘fish_add_path’ to set ‘PATH’ when installing for the Fish shell.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115119

   (2) https://github.com/python/cpython/issues/114099

   (3) https://github.com/python/cpython/issues/115009

   (4) https://github.com/python/cpython/issues/91629


File: python.info,  Node: IDLE<8>,  Next: C API<16>,  Prev: macOS<8>,  Up: Python 3 13 0 beta 1

1.24.19.10 IDLE
...............

   - bpo-34774(1): Use user-selected color theme for Help => IDLE Doc.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34774


File: python.info,  Node: C API<16>,  Prev: IDLE<8>,  Up: Python 3 13 0 beta 1

1.24.19.11 C API
................

   - gh-118124(1): Fix *note Py_BUILD_ASSERT: 199b. and *note
     Py_BUILD_ASSERT_EXPR: 199c. for non-constant expressions: use
     ‘static_assert()’ on C11 and newer.  Patch by Victor Stinner.

   - gh-110850(2): Add «Raw» variant of PyTime functions

        * *note PyTime_MonotonicRaw(): 5d8.

        * *note PyTime_PerfCounterRaw(): 5da.

        * *note PyTime_TimeRaw(): 5dc.

     Patch by Victor Stinner.

   - gh-117987(3): Restore functions removed in Python 3.13 alpha 1:

        * *note Py_SetPythonHome(): 199d.

        * *note Py_SetProgramName(): 199e.

        * *note PySys_SetArgvEx(): 199f.

        * *note PySys_SetArgv(): 19a0.

     Patch by Victor Stinner.

   - gh-117929(4): Restore removed *note PyEval_InitThreads(): 19a1.
     function.  Patch by Victor Stinner.

   - gh-117534(5): Improve validation logic in the C implementation of
     *note datetime.datetime.fromisoformat(): 82b. to better handle
     invalid years.  Patch by Vlad Efanov.

   - gh-68114(6): Fixed skipitem()”s handling of the old “w” and “w#”
     formatters.  These are no longer supported and now raise an
     exception if used.

   - gh-111997(7): Add a C-API for firing monitoring events.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/118124

   (2) https://github.com/python/cpython/issues/110850

   (3) https://github.com/python/cpython/issues/117987

   (4) https://github.com/python/cpython/issues/117929

   (5) https://github.com/python/cpython/issues/117534

   (6) https://github.com/python/cpython/issues/68114

   (7) https://github.com/python/cpython/issues/111997


File: python.info,  Node: Python 3 13 0 alpha 6,  Next: Python 3 13 0 alpha 5,  Prev: Python 3 13 0 beta 1,  Up: Changelog

1.24.20 Python 3.13.0 alpha 6
-----------------------------

'Release date: 2024-04-09'

* Menu:

* Core and Builtins: Core and Builtins<50>.
* Library: Library<55>.
* Core and Builtins: Core and Builtins<51>.
* Library: Library<56>.
* Documentation: Documentation<15>.
* Tests: Tests<14>.
* Build: Build<17>.
* Windows: Windows<15>.
* C API: C API<17>.


File: python.info,  Node: Core and Builtins<50>,  Next: Library<55>,  Up: Python 3 13 0 alpha 6

1.24.20.1 Core and Builtins
...........................

   - gh-117494(1): Refactored the instruction sequence data structure
     out of compile.c into instruction_sequence.c.

   - gh-116968(2): Introduce a unified 16-bit backoff counter type
     (‘_Py_BackoffCounter’), shared between the Tier 1 adaptive
     specializer and the Tier 2 optimizer.  The API used for adaptive
     specialization counters is changed but the behavior is (supposed to
     be) identical.

     The behavior of the Tier 2 counters is changed:

        * There are no longer dynamic thresholds (we never varied
          these).

        * All counters now use the same exponential backoff.

        * The counter for ‘JUMP_BACKWARD’ starts counting down from 16.

        * The ‘temperature’ in side exits starts counting down from 64.

   - gh-117431(3): Improve the performance of the following *note bytes:
     192. and *note bytearray: 344. methods by adapting them to the
     *note METH_FASTCALL: 1986. calling convention:

        * ‘endswith()’

        * ‘startswith()’

   - gh-117431(4): Improve the performance of the following *note str:
     169. methods by adapting them to the *note METH_FASTCALL: 1986.
     calling convention:

        * *note count(): 1969.

        * *note endswith(): 10ce.

        * *note find(): 10aa.

        * *note index(): 19a4.

        * *note rfind(): 10ab.

        * *note rindex(): 145f.

        * *note startswith(): 10cd.

   - gh-117411(5): Move ‘PyFutureFeatures’ to an internal header and
     make it private.

   - gh-109120(6): Added handle of incorrect star expressions, e.g ‘f(3,
     *)’.  Patch by Grigoryev Semyon

   - gh-117266(7): Fix crashes for certain user-created subclasses of
     *note ast.AST: 4c4.  Such classes are now expected to set the
     ‘_field_types’ attribute.

   - gh-99108(8): Updated the *note hashlib: 6c. built-in HACL*
     project(9) C code from upstream that we use for many
     implementations when they are not present via OpenSSL in a given
     build.  This also avoids the rare potential for a C symbol name one
     definition rule linking issue.

   - gh-117108(10): Change the old space bit of objects in the young
     generation from 0 to gcstate->visited, so that any objects created
     during GC will have the old bit set correctly if they get moved
     into the old generation.

   - gh-117108(11): The cycle GC now chooses the size of increments
     based on the total heap size, instead of the rate of object
     creation.  This ensures that it can keep up with growing heaps.

   - gh-116735(12): For ‘INSTRUMENTED_CALL_FUNCTION_EX’, set ‘arg0’ to
     ‘sys.monitoring.MISSING’ instead of ‘None’ for *note CALL: 19a5.
     event.

   - gh-113964(13): Starting new threads and process creation through
     *note os.fork(): 4b6. are now only prevented once all non-daemon
     threads exit.

   - gh-116626(14): Ensure ‘INSTRUMENTED_CALL_FUNCTION_EX’ always emits
     *note CALL: 19a5.

   - gh-116554(15): ‘list.sort()’ now exploits more cases of partial
     ordering, particularly those with long descending runs with
     sub-runs of equal values.  Those are recognized as single runs now
     (previously, each block of repeated values caused a new run to be
     created).

   - gh-114099(16): Added a Loader that can discover extension modules
     in an iOS-style Frameworks folder.

   - gh-115775(17): Compiler populates the new ‘__static_attributes__’
     field on a class with the names of attributes of this class which
     are accessed through self.X from any function in its body.

   - gh-115776(18): The array of values, the ‘PyDictValues’ struct is
     now embedded in the object during allocation.  This provides better
     performance in the common case, and does not degrade as much when
     the object’s ‘__dict__’ is materialized.

   - gh-108362(19): Implement an incremental cyclic garbage collector.
     By collecting the old generation in increments, there is no need
     for a full heap scan.  This can hugely reduce maximum pause time
     for programs with large heaps.

     Reduce the number of generations from three to two.  The old
     generation is split into two spaces, «visited» and «pending».

     Collection happens in two steps:: * An increment is formed from the
     young generation and a small part of the pending space.  * This
     increment is scanned and the survivors moved to the end of the
     visited space.

     When the collecting space becomes empty, the two spaces are
     swapped.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/117494

   (2) https://github.com/python/cpython/issues/116968

   (3) https://github.com/python/cpython/issues/117431

   (4) https://github.com/python/cpython/issues/117431

   (5) https://github.com/python/cpython/issues/117411

   (6) https://github.com/python/cpython/issues/109120

   (7) https://github.com/python/cpython/issues/117266

   (8) https://github.com/python/cpython/issues/99108

   (9) https://github.com/hacl-star/hacl-star

   (10) https://github.com/python/cpython/issues/117108

   (11) https://github.com/python/cpython/issues/117108

   (12) https://github.com/python/cpython/issues/116735

   (13) https://github.com/python/cpython/issues/113964

   (14) https://github.com/python/cpython/issues/116626

   (15) https://github.com/python/cpython/issues/116554

   (16) https://github.com/python/cpython/issues/114099

   (17) https://github.com/python/cpython/issues/115775

   (18) https://github.com/python/cpython/issues/115776

   (19) https://github.com/python/cpython/issues/108362


File: python.info,  Node: Library<55>,  Next: Core and Builtins<51>,  Prev: Core and Builtins<50>,  Up: Python 3 13 0 alpha 6

1.24.20.2 Library
.................

   - gh-109870(1): Dataclasses now calls *note exec(): 4a3. once per
     dataclass, instead of once per method being added.  This can speed
     up dataclass creation by up to 20%.

   - gh-97901(2): Mime type ‘text/rtf’ is now supported by *note
     mimetypes: 93.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109870

   (2) https://github.com/python/cpython/issues/97901


File: python.info,  Node: Core and Builtins<51>,  Next: Library<56>,  Prev: Library<55>,  Up: Python 3 13 0 alpha 6

1.24.20.3 Core and Builtins
...........................

   - bpo-24612(1): Improve the *note SyntaxError: 18e. that happens when
     “not” appears after an operator.  Patch by Pablo Galindo

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24612


File: python.info,  Node: Library<56>,  Next: Documentation<15>,  Prev: Core and Builtins<51>,  Up: Python 3 13 0 alpha 6

1.24.20.4 Library
.................

   - gh-117648(1): Improve performance of *note os.path.join(): 1991.
     and *note os.path.expanduser(): c0b.

   - gh-117584(2): Raise *note TypeError: 198. for non-paths in *note
     posixpath.relpath: 6d2.

   - gh-117467(3): Preserve mailbox ownership when rewriting in *note
     mailbox.mbox.flush: 19a9.  Patch by Tony Mountifield.

   - gh-114848(4): Raise *note FileNotFoundError: 264. when ‘getcwd()’
     returns “(unreachable)”, which can happen on Linux >= 2.6.36 with
     glibc < 2.27.

   - gh-117459(5): ‘asyncio.asyncio.run_coroutine_threadsafe()’ now
     keeps the traceback of ‘CancelledError’, *note TimeoutError: a38.
     and ‘InvalidStateError’ which are raised in the coroutine.

   - gh-117381(6): Fix error message for ‘ntpath.commonpath()’.

   - gh-117337(7): Deprecate undocumented ‘glob.glob0()’ and
     ‘glob.glob1()’ functions.  Use *note glob.glob(): 5a0. and pass a
     directory to its 'root_dir' argument instead.

   - gh-117349(8): Optimise several functions in *note os.path: a6.

   - gh-117348(9): Refactored ‘configparser.RawConfigParser._read()’ to
     reduce cyclometric complexity and improve comprehensibility.

   - gh-117335(10): Raise TypeError for non-sequences for
     ‘ntpath.commonpath()’.

   - gh-66449(11): *note configparser.ConfigParser: 4df. now accepts
     unnamed sections before named ones, if configured to do so.

   - gh-88014(12): In documentation of *note gzip.GzipFile: 65c. in
     module gzip, explain data type of optional constructor argument
     'mtime', and recommend ‘mtime = 0’ for generating deterministic
     streams.

   - gh-117310(13): Fixed an unlikely early & extra ‘Py_DECREF’
     triggered crash in *note ssl: d5. when creating a new
     ‘_ssl._SSLContext’ if CPython was built implausibly such that the
     default cipher list is empty 'or' the SSL library it was linked
     against reports a failure from its C ‘SSL_CTX_set_cipher_list()’
     API.

   - gh-117294(14): A ‘DocTestCase’ now reports as skipped if all
     examples in the doctest are skipped.

   - gh-98966(15): In *note subprocess: dc, raise a more informative
     message when ‘stdout=STDOUT’.

   - gh-117225(16): doctest: only print «and X failed» when non-zero,
     don’t pluralise «1 items».  Patch by Hugo van Kemenade.

   - gh-117205(17): Speed up *note compileall.compile_dir(): d1d. by 20%
     when using multiprocessing by increasing ‘chunksize’.

   - gh-117178(18): Fix regression in lazy loading of self-referential
     modules, introduced in gh-114781(19).

   - gh-112383(20): Fix *note dis: 3c. module’s handling of
     ‘ENTER_EXECUTOR’ instructions.

   - gh-117182(21): Lazy-loading of modules that modify their own
     ‘__class__’ no longer reverts the ‘__class__’ to *note
     types.ModuleType: 1016.

   - gh-117084(22): Fix *note zipfile: 137. extraction for directory
     entries with the name containing backslashes on Windows.

   - gh-117114(23): Make *note os.path.isdevdrive(): 19aa. available on
     all platforms.  For those that do not offer Dev Drives, it will
     always return ‘False’.

   - gh-117110(24): Fix a bug that prevents subclasses of *note
     typing.Any: 8bc. to be instantiated with arguments.  Patch by Chris
     Fu.

   - gh-109653(25): Deferred select imports in importlib.metadata and
     importlib.resources for a 14% speedup.

   - gh-70647(26): Start the deprecation period for the current behavior
     of *note datetime.datetime.strptime(): 1938. and *note
     time.strptime(): 1634. which always fails to parse a date string
     with a *note ValueError: 2ec. involving a day of month such as
     ‘strptime("02-29", "%m-%d")’ when a year is 'not' specified and the
     date happen to be February 29th.  This should help avoid users
     finding new bugs every four years due to a natural mistaken
     assumption about the API when parsing partial date values.

   - gh-116987(27): Fixed ‘inspect.findsource()’ for class code objects.

   - gh-114099(28): Modify standard library to allow for iOS platform
     differences.

   - gh-90872(29): On Windows, *note subprocess.Popen.wait(): ee2. no
     longer calls ‘WaitForSingleObject()’ with a negative timeout: pass
     ‘0’ ms if the timeout is negative.  Patch by Victor Stinner.

   - gh-116957(30): configparser: Don’t leave ConfigParser values in an
     invalid state (stored as a list instead of a str) after an earlier
     read raised DuplicateSectionError or DuplicateOptionError.

   - gh-115538(31): ‘_io.WindowsConsoleIO’ now emit a warning if a
     boolean value is passed as a filedescriptor argument.

   - gh-90095(32): Ignore empty lines and comments in ‘.pdbrc’

   - gh-106531(33): Refreshed zipfile._path from zipp 3.18(34),
     providing better compatibility for PyPy, better glob performance
     for deeply nested zipfiles, and providing internal access to
     ‘CompleteDirs.inject’ for use in other tests (like
     importlib.resources).

   - gh-63207(35): On Windows, *note time.time(): 55d. now uses the
     ‘GetSystemTimePreciseAsFileTime()’ clock to have a resolution
     better than 1 us, instead of the ‘GetSystemTimeAsFileTime()’ clock
     which has a resolution of 15.6 ms.  Patch by Victor Stinner.

   - gh-116764(36): Restore support of ‘None’ and other false values in
     *note urllib.parse: 110. functions *note parse_qs(): 31f. and *note
     parse_qsl(): 31e.  Also, they now raise a TypeError for non-zero
     integers and non-empty sequences.

   - gh-116811(37): In ‘PathFinder.invalidate_caches’, delegate to
     ‘MetadataPathFinder.invalidate_caches’.

   - gh-116647(38): Fix recursive child in dataclasses

   - gh-113171(39): Fixed various false positives and false negatives in

        * *note ipaddress.IPv4Address.is_private: 19ab. (see these docs
          for details)

        * *note ipaddress.IPv4Address.is_global: 1161.

        * *note ipaddress.IPv6Address.is_private: 19ac.

        * *note ipaddress.IPv6Address.is_global: 19ad.

     Also in the corresponding *note ipaddress.IPv4Network: 50f. and
     *note ipaddress.IPv6Network: 510. attributes.

   - gh-63283(40): In *note encodings.idna: 56, any capitalization of
     the ACE prefix (‘xn--’) is now acceptable.  Patch by Pepijn de Vos
     and Zackery Spytz.

   - gh-71042(41): Add *note platform.android_ver(): 19ae, which
     provides device and OS information on Android.

   - gh-73468(42): Added new *note math.fma(): 515. function, wrapping
     C99’s ‘fma()’ operation: fused multiply-add function.  Patch by
     Mark Dickinson and Victor Stinner.

   - gh-116608(43): The *note importlib.resources: 7f. functions *note
     is_resource(): 4fe, *note open_binary(): 4ff, *note open_text():
     500, *note path(): 501, *note read_binary(): 502, and *note
     read_text(): 503. are un-deprecated, and support subdirectories via
     multiple positional arguments.  The *note contents(): 504. function
     also allows subdirectories, but remains deprecated.

   - gh-116484(44): Change automatically generated ‘tkinter.Checkbutton’
     widget names to avoid collisions with automatically generated
     ‘tkinter.ttk.Checkbutton’ widget names within the same parent
     widget.

   - gh-114314(45): In *note ctypes: 2e, ctype data is now stored in
     type objects directly rather than in a dict subclass.  This is an
     internal change that should not affect usage.

   - gh-116401(46): Fix blocking *note os.fwalk(): d54. and *note
     shutil.rmtree(): 356. on opening named pipe.

   - gh-71052(47): Implement *note ctypes.util.find_library(): f47. on
     Android.

   - gh-90535(48): Fix support of 'interval' values > 1 in
     ‘logging.TimedRotatingFileHandler’ for ‘when='MIDNIGHT'’ and
     ‘when='Wx'’.

   - gh-113308(49): Remove some internal protected parts from *note
     uuid: 116.: ‘_has_uuid_generate_time_safe’, ‘_netbios_getnode’,
     ‘_ipconfig_getnode’, and ‘_load_system_functions’.  They were
     unused.

   - gh-115627(50): Fix the *note ssl: d5. module error handling of
     connection terminate by peer.  It now throws an OSError with the
     appropriate error code instead of an EOFError.

   - gh-114847(51): Speed up *note os.path.realpath(): 262. on
     non-Windows platforms.

   - gh-114271(52): Fix a race in ‘threading.Thread.join()’.

     ‘threading._MainThread’ now always represents the main thread of
     the main interpreter.

     ‘PyThreadState.on_delete’ and ‘PyThreadState.on_delete_data’ have
     been removed.

   - gh-113538(53): Add *note asyncio.Server.close_clients(): 4cf. and
     *note asyncio.Server.abort_clients(): 4d0. methods which allow to
     more forcefully close an asyncio server.

   - gh-85287(54): Changes Unicode codecs to return UnicodeEncodeError
     or UnicodeDecodeError, rather than just UnicodeError.

   - gh-113548(55): *note pdb: aa. now allows CLI arguments to ‘pdb -m’.

   - gh-112948(56): Make completion of *note pdb: aa. similar to Python
     REPL

   - gh-105866(57): Fixed ‘_get_slots’ bug which caused error when
     defining dataclasses with slots and a weakref_slot.

   - gh-96471(58): Add *note asyncio.Queue: c6c. termination with *note
     shutdown(): 4cd. method.

   - gh-89739(59): The *note zipimport: 138. module can now read ZIP64
     files.

   - bpo-33533(60): *note asyncio.as_completed(): 4c7. now returns an
     object that is both an asynchronous iterator and plain iterator.
     The new asynchronous iteration pattern allows for easier
     correlation between prior tasks and their completed results.  This
     is a closer match to *note concurrent.futures.as_completed():
     19af.”s iteration pattern.  Patch by Justin Arthur.

   - bpo-27578(61): *note inspect.getsource(): 17ab. (and related
     functions) work with empty module files, returning ‘'\n'’ (or
     reasonable equivalent) instead of raising ‘OSError’.  Patch by
     Kernc.

   - bpo-37141(62): Accept an iterable of separators in *note
     asyncio.StreamReader.readuntil(): 4d1, stopping when one of them is
     encountered.

   - gh-66543(63): Make *note mimetypes.guess_type(): 518. properly
     parsing of URLs with only a host name, URLs containing fragment or
     query, and filenames with only a UNC sharepoint on Windows.  Based
     on patch by Dong-hee Na.

   - bpo-15010(64): *note unittest.TestLoader.discover(): 11e7. now
     saves the original value of ‘unittest.TestLoader._top_level_dir’
     and restores it at the end of the call.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/117648

   (2) https://github.com/python/cpython/issues/117584

   (3) https://github.com/python/cpython/issues/117467

   (4) https://github.com/python/cpython/issues/114848

   (5) https://github.com/python/cpython/issues/117459

   (6) https://github.com/python/cpython/issues/117381

   (7) https://github.com/python/cpython/issues/117337

   (8) https://github.com/python/cpython/issues/117349

   (9) https://github.com/python/cpython/issues/117348

   (10) https://github.com/python/cpython/issues/117335

   (11) https://github.com/python/cpython/issues/66449

   (12) https://github.com/python/cpython/issues/88014

   (13) https://github.com/python/cpython/issues/117310

   (14) https://github.com/python/cpython/issues/117294

   (15) https://github.com/python/cpython/issues/98966

   (16) https://github.com/python/cpython/issues/117225

   (17) https://github.com/python/cpython/issues/117205

   (18) https://github.com/python/cpython/issues/117178

   (19) https://github.com/python/cpython/issues/114781

   (20) https://github.com/python/cpython/issues/112383

   (21) https://github.com/python/cpython/issues/117182

   (22) https://github.com/python/cpython/issues/117084

   (23) https://github.com/python/cpython/issues/117114

   (24) https://github.com/python/cpython/issues/117110

   (25) https://github.com/python/cpython/issues/109653

   (26) https://github.com/python/cpython/issues/70647

   (27) https://github.com/python/cpython/issues/116987

   (28) https://github.com/python/cpython/issues/114099

   (29) https://github.com/python/cpython/issues/90872

   (30) https://github.com/python/cpython/issues/116957

   (31) https://github.com/python/cpython/issues/115538

   (32) https://github.com/python/cpython/issues/90095

   (33) https://github.com/python/cpython/issues/106531

   (34) https://zipp.readthedocs.io/en/latest/history.html#v3-18-0

   (35) https://github.com/python/cpython/issues/63207

   (36) https://github.com/python/cpython/issues/116764

   (37) https://github.com/python/cpython/issues/116811

   (38) https://github.com/python/cpython/issues/116647

   (39) https://github.com/python/cpython/issues/113171

   (40) https://github.com/python/cpython/issues/63283

   (41) https://github.com/python/cpython/issues/71042

   (42) https://github.com/python/cpython/issues/73468

   (43) https://github.com/python/cpython/issues/116608

   (44) https://github.com/python/cpython/issues/116484

   (45) https://github.com/python/cpython/issues/114314

   (46) https://github.com/python/cpython/issues/116401

   (47) https://github.com/python/cpython/issues/71052

   (48) https://github.com/python/cpython/issues/90535

   (49) https://github.com/python/cpython/issues/113308

   (50) https://github.com/python/cpython/issues/115627

   (51) https://github.com/python/cpython/issues/114847

   (52) https://github.com/python/cpython/issues/114271

   (53) https://github.com/python/cpython/issues/113538

   (54) https://github.com/python/cpython/issues/85287

   (55) https://github.com/python/cpython/issues/113548

   (56) https://github.com/python/cpython/issues/112948

   (57) https://github.com/python/cpython/issues/105866

   (58) https://github.com/python/cpython/issues/96471

   (59) https://github.com/python/cpython/issues/89739

   (60) https://bugs.python.org/issue?@action=redirect&bpo=33533

   (61) https://bugs.python.org/issue?@action=redirect&bpo=27578

   (62) https://bugs.python.org/issue?@action=redirect&bpo=37141

   (63) https://github.com/python/cpython/issues/66543

   (64) https://bugs.python.org/issue?@action=redirect&bpo=15010


File: python.info,  Node: Documentation<15>,  Next: Tests<14>,  Prev: Library<56>,  Up: Python 3 13 0 alpha 6

1.24.20.5 Documentation
.......................

   - gh-115977(1): Remove compatibility references to Emscripten.

   - gh-114099(2): Add an iOS platform guide, and flag modules not
     available on iOS.

   - gh-91565(3): Changes to documentation files and config outputs to
     reflect the new location for reporting bugs - i.e.  GitHub rather
     than bugs.python.org.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115977

   (2) https://github.com/python/cpython/issues/114099

   (3) https://github.com/python/cpython/issues/91565


File: python.info,  Node: Tests<14>,  Next: Build<17>,  Prev: Documentation<15>,  Up: Python 3 13 0 alpha 6

1.24.20.6 Tests
...............

   - gh-83434(1): Disable JUnit XML output (‘--junit-xml=FILE’ command
     line option) in regrtest when hunting for reference leaks (‘-R’
     option).  Patch by Victor Stinner.

   - gh-117187(2): Fix XML tests for vanilla Expat <2.6.0.

   - gh-116333(3): Tests of TLS related things (error codes, etc) were
     updated to be more lenient about specific error message strings and
     behaviors as seen in the BoringSSL and AWS-LC forks of OpenSSL.

   - gh-117089(4): Consolidated tests for importlib.metadata in their
     own ‘metadata’ package.

   - gh-115979(5): Update test_importlib so that it passes under WASI
     SDK 21.

   - gh-112536(6): Add –tsan to test.regrtest for running TSAN tests in
     reasonable execution times.  Patch by Donghee Na.

   - gh-116307(7): Added import helper ‘isolated_modules’ as
     ‘CleanImport’ does not remove modules imported during the context.
     Use it in importlib.resources tests to avoid leaving ‘mod’ around
     to impede importlib.metadata tests.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/83434

   (2) https://github.com/python/cpython/issues/117187

   (3) https://github.com/python/cpython/issues/116333

   (4) https://github.com/python/cpython/issues/117089

   (5) https://github.com/python/cpython/issues/115979

   (6) https://github.com/python/cpython/issues/112536

   (7) https://github.com/python/cpython/issues/116307


File: python.info,  Node: Build<17>,  Next: Windows<15>,  Prev: Tests<14>,  Up: Python 3 13 0 alpha 6

1.24.20.7 Build
...............

   - gh-114736(1): Have WASI builds use WASI SDK 21.

   - gh-115983(2): Skip building test modules that must be built as
     shared under WASI.

   - gh-71052(3): Add Android build script and instructions.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/114736

   (2) https://github.com/python/cpython/issues/115983

   (3) https://github.com/python/cpython/issues/71052


File: python.info,  Node: Windows<15>,  Next: C API<17>,  Prev: Build<17>,  Up: Python 3 13 0 alpha 6

1.24.20.8 Windows
.................

   - gh-117267(1): Ensure ‘DirEntry.stat().st_ctime’ behaves
     consistently with *note os.stat(): 26d. during the deprecation
     period of ‘st_ctime’ by containing the same value as
     ‘st_birthtime’.  After the deprecation period, ‘st_ctime’ will be
     the metadata change time (or unavailable through ‘DirEntry’), and
     only ‘st_birthtime’ will contain the creation time.

   - gh-116195(2): Improves performance of *note os.getppid(): 19b4. by
     using an alternate system API when available.  Contributed by
     vxiiduu.

   - gh-88494(3): On Windows, *note time.monotonic(): 55c. now uses the
     ‘QueryPerformanceCounter()’ clock to have a resolution better than
     1 us, instead of the ‘GetTickCount64()’ clock which has a
     resolution of 15.6 ms.  Patch by Victor Stinner.

   - gh-116773(4): Fix instances of ‘<_overlapped.Overlapped object at
     0xXXX> still has pending operation at deallocation, the process may
     crash’.

   - gh-91227(5): Fix the asyncio ProactorEventLoop implementation so
     that sending a datagram to an address that is not listening does
     not prevent receiving any more datagrams.

   - gh-115119(6): Switched from vendored ‘libmpdecimal’ code to a
     separately-hosted external package in the ‘cpython-source-deps’
     repository when building the ‘_decimal’ module.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/117267

   (2) https://github.com/python/cpython/issues/116195

   (3) https://github.com/python/cpython/issues/88494

   (4) https://github.com/python/cpython/issues/116773

   (5) https://github.com/python/cpython/issues/91227

   (6) https://github.com/python/cpython/issues/115119


File: python.info,  Node: C API<17>,  Prev: Windows<15>,  Up: Python 3 13 0 alpha 6

1.24.20.9 C API
...............

   - gh-117642(1): Fix PEP 737(2) implementation for ‘%#T’ and ‘%#N’.

   - gh-87193(3): *note _PyBytes_Resize(): 19b6. can now be called for
     bytes objects with reference count > 1, including 1-byte bytes
     objects.  It creates a new bytes object and destroys the old one if
     it has reference count > 1.

   - gh-117021(4): Fix integer overflow in *note PyLong_AsPid(): 19b7.
     on non-Windows 64-bit platforms.

   - gh-115756(5): ‘PyCode_GetFirstFree()’ is an ustable API now and has
     been renamed to *note PyUnstable_Code_GetFirstFree(): 627.
     (Contributed by Bogdan Romanyuk in gh-115781(6))

   - gh-116869(7): Add ‘test_cext’ test: build a C extension to check if
     the Python C API emits C compiler warnings.  Patch by Victor
     Stinner.

   - gh-116869(8): Make the C API compatible with
     ‘-Werror=declaration-after-statement’ compiler flag again.  Patch
     by Victor Stinner.

   - gh-116936(9): Add *note PyType_GetModuleByDef(): 635. to the
     limited C API. Patch by Victor Stinner.

   - gh-116809(10): Restore removed private ‘_PyErr_ChainExceptions1()’
     function.  Patch by Victor Stinner.

   - gh-115754(11): In the limited C API version 3.13, getting
     ‘Py_None’, ‘Py_False’, ‘Py_True’, ‘Py_Ellipsis’ and
     ‘Py_NotImplemented’ singletons is now implemented as function calls
     at the stable ABI level to hide implementation details.  Getting
     these constants still return borrowed references.  Patch by Victor
     Stinner.

   - gh-115754(12): Add *note Py_GetConstant(): 5f9. and *note
     Py_GetConstantBorrowed(): 5fa. functions to get constants.  For
     example, ‘Py_GetConstant(Py_CONSTANT_ZERO)’ returns a *note strong
     reference: 5e2. to the constant zero.  Patch by Victor Stinner.

   - gh-111696(13): Add support for ‘%T’, ‘%T#’, ‘%N’ and ‘%N#’ formats
     to *note PyUnicode_FromFormat(): 62b.: format the fully qualified
     name of an object type and of a type: call *note
     PyType_GetModuleName(): 618.  See PEP 737(14) for more information.
     Patch by Victor Stinner.

   - gh-111696(15): Add *note PyType_GetModuleName(): 618. function to
     get the type’s module name.  Equivalent to getting the
     ‘type.__module__’ attribute.  Patch by Eric Snow and Victor
     Stinner.

   - gh-111696(16): Add *note PyType_GetFullyQualifiedName(): 616.
     function to get the type’s fully qualified name.  Equivalent to
     ‘f"{type.__module__}.{type.__qualname__}"’, or ‘type.__qualname__’
     if ‘type.__module__’ is not a string or is equal to ‘"builtins"’.
     Patch by Victor Stinner.

   - gh-85283(17): The ‘fcntl’, ‘grp’, ‘pwd’, ‘termios’, ‘_statistics’
     and ‘_testconsole’ C extensions are now built with the *note
     limited C API: 637.  Patch by Victor Stinner.

   - gh-111140(18): Add additional flags to *note
     PyLong_AsNativeBytes(): 606. and *note PyLong_FromNativeBytes():
     607. to allow the caller to determine how to handle edge cases
     around values that fill the entire buffer.

   - gh-113024(19): Add *note PyObject_GenericHash(): 60c. function.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/117642

   (2) https://peps.python.org/pep-0737/

   (3) https://github.com/python/cpython/issues/87193

   (4) https://github.com/python/cpython/issues/117021

   (5) https://github.com/python/cpython/issues/115756

   (6) https://github.com/python/cpython/issues/115781

   (7) https://github.com/python/cpython/issues/116869

   (8) https://github.com/python/cpython/issues/116869

   (9) https://github.com/python/cpython/issues/116936

   (10) https://github.com/python/cpython/issues/116809

   (11) https://github.com/python/cpython/issues/115754

   (12) https://github.com/python/cpython/issues/115754

   (13) https://github.com/python/cpython/issues/111696

   (14) https://peps.python.org/pep-0737/

   (15) https://github.com/python/cpython/issues/111696

   (16) https://github.com/python/cpython/issues/111696

   (17) https://github.com/python/cpython/issues/85283

   (18) https://github.com/python/cpython/issues/111140

   (19) https://github.com/python/cpython/issues/113024


File: python.info,  Node: Python 3 13 0 alpha 5,  Next: Python 3 13 0 alpha 4,  Prev: Python 3 13 0 alpha 6,  Up: Changelog

1.24.21 Python 3.13.0 alpha 5
-----------------------------

'Release date: 2024-03-12'

* Menu:

* Security: Security<18>.
* Core and Builtins: Core and Builtins<52>.
* Library: Library<57>.
* Core and Builtins: Core and Builtins<53>.
* Library: Library<58>.
* Core and Builtins: Core and Builtins<54>.
* Library: Library<59>.
* Documentation: Documentation<16>.
* Tests: Tests<15>.
* Build: Build<18>.
* Windows: Windows<16>.
* macOS: macOS<9>.
* IDLE: IDLE<9>.
* Tools/Demos: Tools/Demos<16>.
* C API: C API<18>.


File: python.info,  Node: Security<18>,  Next: Core and Builtins<52>,  Up: Python 3 13 0 alpha 5

1.24.21.1 Security
..................

   - gh-115398(1): Allow controlling Expat >=2.6.0 reparse deferral (
     CVE 2023-52425(2)) by adding five new methods:

        * *note xml.etree.ElementTree.XMLParser.flush(): 576.

        * *note xml.etree.ElementTree.XMLPullParser.flush(): 577.

        * *note xml.parsers.expat.xmlparser.GetReparseDeferralEnabled():
          578.

        * *note xml.parsers.expat.xmlparser.SetReparseDeferralEnabled():
          579.

        * ‘xml.sax.expatreader.ExpatParser.flush()’

   - gh-114572(3): *note ssl.SSLContext.cert_store_stats(): 11ae. and
     *note ssl.SSLContext.get_ca_certs(): 11af. now correctly lock
     access to the certificate store, when the *note ssl.SSLContext:
     357. is shared across multiple threads.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115398

   (2) https://www.cve.org/CVERecord?id=CVE-2023-52425

   (3) https://github.com/python/cpython/issues/114572


File: python.info,  Node: Core and Builtins<52>,  Next: Library<57>,  Prev: Security<18>,  Up: Python 3 13 0 alpha 5

1.24.21.2 Core and Builtins
...........................

   - gh-116604(1): Respect the status of the garbage collector when
     indirect calls are made via *note PyErr_CheckSignals(): 694. and
     the evaluation breaker.  Patch by Pablo Galindo

   - gh-112087(2): *note list: 24d. is now compatible with the
     implementation of PEP 703(3).

   - gh-116381(4): Add specialization for ‘CONTAINS_OP’.

   - gh-116296(5): Fix possible refleak in ‘object.__reduce__()’
     internal error handling.

   - gh-115823(6): Properly calculate error ranges in the parser when
     raising *note SyntaxError: 18e. exceptions caused by invalid byte
     sequences.  Patch by Pablo Galindo

   - gh-115778(7): Add ‘tierN’ annotation for instruction definition in
     interpreter DSL.

   - gh-115733(8): Fix crash when calling ‘next()’ on exhausted list
     iterators.

   - gh-115700(9): The regen-cases build stage now works on Windows.

   - gh-115347(10): Fix bug where docstring was replaced by a redundant
     NOP when Python is run with ‘-OO’.

   - gh-115323(11): Make error message more meaningful for when *note
     bytearray.extend(): 1779. is called with a *note str: 169. object.

   - gh-112175(12): Every ‘PyThreadState’ now has its own
     ‘eval_breaker’, allowing specific threads to be interrupted.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116604

   (2) https://github.com/python/cpython/issues/112087

   (3) https://peps.python.org/pep-0703/

   (4) https://github.com/python/cpython/issues/116381

   (5) https://github.com/python/cpython/issues/116296

   (6) https://github.com/python/cpython/issues/115823

   (7) https://github.com/python/cpython/issues/115778

   (8) https://github.com/python/cpython/issues/115733

   (9) https://github.com/python/cpython/issues/115700

   (10) https://github.com/python/cpython/issues/115347

   (11) https://github.com/python/cpython/issues/115323

   (12) https://github.com/python/cpython/issues/112175


File: python.info,  Node: Library<57>,  Next: Core and Builtins<53>,  Prev: Core and Builtins<52>,  Up: Python 3 13 0 alpha 5

1.24.21.3 Library
.................

   - gh-115154(1): Fix a bug that was causing the *note
     tokenize.untokenize(): 189b. function to handle unicode named
     literals incorrectly.  Patch by Pablo Galindo

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115154


File: python.info,  Node: Core and Builtins<53>,  Next: Library<58>,  Prev: Library<57>,  Up: Python 3 13 0 alpha 5

1.24.21.4 Core and Builtins
...........................

   - gh-112433(1): Add ability to force alignment of *note
     ctypes.Structure: 1e5. by way of the new ‘_align_’ attribute on the
     class.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/112433


File: python.info,  Node: Library<58>,  Next: Core and Builtins<54>,  Prev: Core and Builtins<53>,  Up: Python 3 13 0 alpha 5

1.24.21.5 Library
.................

   - gh-104090(1): The multiprocessing resource tracker now exits with
     non-zero status code if a resource leak was detected.  It still
     exits with status code 0 otherwise.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104090


File: python.info,  Node: Core and Builtins<54>,  Next: Library<59>,  Prev: Library<58>,  Up: Python 3 13 0 alpha 5

1.24.21.6 Core and Builtins
...........................

   - gh-105858(1): Improve the constructors for *note ast: 9. nodes.
     Arguments of list types now default to an empty list if omitted,
     and optional fields default to ‘None’.  AST nodes now have an
     ‘__annotations__’ attribute with the expected types of their
     attributes.  Passing unrecognized extra arguments to AST nodes is
     deprecated and will become an error in Python 3.15.  Omitting a
     required argument to an AST node is deprecated and will become an
     error in Python 3.15.  Patch by Jelle Zijlstra.

   - gh-101860(2): Expose ‘__name__’ attribute on property.

   - gh-96497(3): Fix incorrect resolution of mangled class variables
     used in assignment expressions in comprehensions.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/105858

   (2) https://github.com/python/cpython/issues/101860

   (3) https://github.com/python/cpython/issues/96497


File: python.info,  Node: Library<59>,  Next: Documentation<16>,  Prev: Core and Builtins<54>,  Up: Python 3 13 0 alpha 5

1.24.21.7 Library
.................

   - gh-116600(1): Fix *note repr(): 1c1. for global *note Flag: 836.
     members.

   - gh-116349(2): *note platform.java_ver(): 32c. is deprecated and
     will be removed in 3.15.  It was largely untested, had a confusing
     API, and was only useful for Jython support.

   - gh-116143(3): Fix a race in pydoc ‘_start_server’, eliminating a
     window in which ‘_start_server’ can return a thread that is
     «serving» but without a ‘docserver’ set.

   - gh-116127(4): *note typing: 10a.: implement PEP 705(5) which adds
     *note typing.ReadOnly: 48b. support to *note typing.TypedDict: 332.

   - gh-116325(6): *note typing: 10a.: raise *note SyntaxError: 18e.
     instead of *note AttributeError: 5f0. on forward references as
     empty strings.

   - gh-115957(7): When ‘asyncio.TaskGroup.create_task’ is called on an
     inactive ‘asyncio.TaskGroup’, the given coroutine will be closed
     (which prevents a ‘RuntimeWarning’).

   - gh-115978(8): Disable preadv(), readv(), pwritev(), and writev() on
     WASI.

     Under wasmtime for WASI 0.2, these functions don’t pass test_posix
     (‘https://github.com/bytecodealliance/wasmtime/issues/7830’).

   - gh-88352(9): Fix the computation of the next rollover time in the
     ‘logging.TimedRotatingFileHandler’ handler.  ‘computeRollover()’
     now always returns a timestamp larger than the specified time and
     works correctly during the DST change.  ‘doRollover()’ no longer
     overwrite the already rolled over file, saving from data loss when
     run at midnight or during repeated time at the DST change.

   - gh-87115(10): Set ‘__main__.__spec__’ to ‘None’ when running a
     script with *note pdb: aa.

   - gh-76511(11): Fix UnicodeEncodeError in ‘email.Message.as_string()’
     that results when a message that claims to be in the ascii
     character set actually has non-ascii characters.  Non-ascii
     characters are now replaced with the U+FFFD replacement character,
     like in the ‘replace’ error handler.

   - gh-89547(12): Add support for nested typing special forms like
     Final[ClassVar[int]].

   - gh-65824(13): Improve the ‘less’ prompt in *note pydoc: ba.

   - gh-116040(14): [Enum] fix by-value calls when second value is
     falsey; e.g.  Cardinal(1, 0)

   - gh-115821(15): [Enum] Improve error message when calling
     super().__new__() in custom __new__.

   - gh-85644(16): Use the ‘XDG_CURRENT_DESKTOP’ environment variable in
     *note webbrowser: 11b. to check desktop.  Prefer it to the
     deprecated ‘GNOME_DESKTOP_SESSION_ID’ for GNOME detection.

   - gh-75988(17): Fixed *note unittest.mock.create_autospec(): 191c. to
     pass the call through to the wrapped object to return the real
     result.

   - gh-115881(18): Fix issue where *note ast.parse(): 1c2. would
     incorrectly flag conditional context managers (such as ‘with (x()
     if y else z()): ...’) as invalid syntax if ‘feature_version=(3, 8)’
     was passed.  This reverts changes to the grammar made as part of
     gh-94949(19).

   - gh-115886(20): Fix silent truncation of the name with an embedded
     null character in *note multiprocessing.shared_memory.SharedMemory:
     19c0.

   - gh-115532(21): Add kernel density estimation to the statistics
     module.

   - gh-115714(22): On WASI, the *note time: f4. module no longer get
     process time using ‘times()’ or ‘CLOCK_PROCESS_CPUTIME_ID’, system
     API is that is unreliable and is likely to be removed from WASI.
     The affected clock functions fall back to calling ‘clock()’.

   - gh-115809(23): Improve algorithm for computing which rolled-over
     log files to delete in ‘logging.TimedRotatingFileHandler’.  It is
     now reliable for handlers without ‘namer’ and with arbitrary
     deterministic ‘namer’ that leaves the datetime part in the file
     name unmodified.

   - gh-74668(24): *note urllib.parse: 110. functions *note parse_qs():
     31f. and *note parse_qsl(): 31e. now support bytes arguments
     containing raw and percent-encoded non-ASCII data.

   - gh-67044(25): *note csv.writer(): 6b0. now always quotes or escapes
     ‘'\r'’ and ‘'\n'’, regardless of 'lineterminator' value.

   - gh-115712(26): Restore support of space delimiter with
     ‘skipinitialspace=True’ in *note csv: 2d.  *note csv.writer(): 6b0.
     now quotes empty fields if delimiter is a space and
     skipinitialspace is true and raises exception if quoting is not
     possible.

   - gh-112364(27): Fixed *note ast.unparse(): ae4. to handle
     format_spec with ‘"’, ‘'’ or ‘\\’.  Patched by Frank Hoffmann.

   - gh-112997(28): Stop logging potentially sensitive callback
     arguments in *note asyncio: b. unless debug mode is active.

   - gh-114914(29): Fix an issue where an abandoned ‘StreamWriter’ would
     not be garbage collected.

   - gh-111358(30): Fix a bug in
     ‘asyncio.BaseEventLoop.shutdown_default_executor()’ to ensure the
     timeout passed to the coroutine behaves as expected.

   - gh-115618(31): Fix improper decreasing the reference count for
     ‘None’ argument in *note property: 4b4. methods *note getter():
     19c1, *note setter(): 19c2. and *note deleter(): 19c3.

   - gh-112720(32): Refactor ‘dis.ArgResolver’ to make it possible to
     subclass and change the way jump args are interpreted.

   - gh-112006(33): Fix *note inspect.unwrap(): 115e. for types with the
     ‘__wrapper__’ data descriptor.  Fix *note
     inspect.Signature.from_callable(): 943. for builtins *note
     classmethod(): 48f. and *note staticmethod(): 453.

   - gh-101293(34): Support callables with the ‘__call__()’ method and
     types with ‘__new__()’ and ‘__init__()’ methods set to class
     methods, static methods, bound methods, partial functions, and
     other types of methods and descriptors in *note
     inspect.Signature.from_callable(): 943.

   - gh-103092(35): Isolate ‘_lsprof’ (apply PEP 687(36)).

   - gh-113942(37): *note pydoc: ba. no longer skips global functions
     implemented as builtin methods, such as ‘MethodDescriptorType’ and
     ‘WrapperDescriptorType’.

   - gh-115256(38): Added DeprecationWarning when accessing the tarfile
     attribute of TarInfo objects.  The attribute is never used
     internally and is only attached to TarInfos when the tarfile is
     opened in write-mode, not read-mode.  The attribute creates an
     unnecessary reference cycle which may cause corruption when not
     closing the handle after writing a tarfile.

   - gh-115197(39): ‘urllib.request’ no longer resolves the hostname
     before checking it against the system’s proxy bypass list on macOS
     and Windows.

   - gh-113812(40): ‘DatagramTransport.sendto()’ will now send
     zero-length datagrams if called with an empty bytes object.  The
     transport flow control also now accounts for the datagram header
     when calculating the buffer size.

   - gh-114763(41): Protect modules loaded with *note
     importlib.util.LazyLoader: ead. from race conditions when multiple
     threads try to access attributes before the loading is complete.

   - gh-114709(42): ‘posixpath.commonpath()’ now raises a *note
     ValueError: 2ec. exception when passed an empty iterable.
     Previously, *note IndexError: 173c. was raised.

     ‘posixpath.commonpath()’ now raises a *note TypeError: 198.
     exception when passed ‘None’.  Previously, *note ValueError: 2ec.
     was raised.

   - gh-114610(43): Fix bug where *note pathlib.PurePath.with_stem():
     19c4. converted a non-empty path suffix to a stem when given an
     empty 'stem' argument.  It now raises *note ValueError: 2ec, just
     like *note pathlib.PurePath.with_suffix(): 193e. does when called
     on a path with an empty stem, given a non-empty 'suffix' argument.

   - gh-107361(44): Add *note ssl.VERIFY_X509_PARTIAL_CHAIN: 481. and
     ‘VERIFY_X509_STRICT’ to the default SSL context created with *note
     ssl.create_default_context(): 480.

   - gh-112281(45): Allow creating *note union of types: 9c7. for *note
     typing.Annotated: b39. with unhashable metadata.

   - gh-111775(46): Fix
     ‘importlib.resources.simple.ResourceHandle.open()’ for text mode,
     added missed ‘stream’ argument.

   - gh-90095(47): Make .pdbrc and -c work with any valid pdb commands.

   - gh-107625(48): Raise *note configparser.ParsingError: 72a. from
     *note read(): 166f. and *note read_file(): 72b. methods of *note
     configparser.ConfigParser: 4df. if a key without a corresponding
     value is continued (that is, followed by an indented line).

   - gh-107155(49): Fix incorrect output of ‘help(x)’ where ‘x’ is a
     *note lambda: 14a5. function, which has an ‘__annotations__’
     dictionary attribute with a ‘"return"’ key.

   - gh-57141(50): Add option for 'non-shallow' comparisons to *note
     filecmp.dircmp: 1142. like *note filecmp.cmp(): 19c5.  Original
     patch by Steven Ward.  Enhanced by Tobias Rautenkranz

   - gh-69990(51): ‘Profile.print_stats()’ has been improved to accept
     multiple sort arguments.  Patched by Chiu-Hsiang Hsu and Furkan
     Onder.

   - gh-104061(52): Add ‘socket.SO_BINDTOIFINDEX’ constant.

   - gh-60346(53): Fix ArgumentParser inconsistent with
     parse_known_args.

   - gh-102389(54): Add ‘windows_31j’ to aliases for ‘cp932’ codec

   - gh-72249(55): Always include the *note module: 19c6. name in the
     *note repr(): 1c1. of *note functools.partial(): 217. objects.
     Patch by Furkan Onder and Anilyka Barry.

   - gh-100985(56): Update HTTPSConnection to consistently wrap IPv6
     Addresses when using a proxy.

   - gh-100884(57): email: fix misfolding of comma in address-lists over
     multiple lines in combination with unicode encoding.

   - gh-95782(58): Fix ‘io.BufferedReader.tell()’,
     ‘io.BufferedReader.seek()’, ‘_pyio.BufferedReader.tell()’,
     ‘io.BufferedRandom.tell()’, ‘io.BufferedRandom.seek()’ and
     ‘_pyio.BufferedRandom.tell()’ being able to return negative
     offsets.

   - gh-96310(59): Fix a traceback in *note argparse: 7. when all
     options in a mutually exclusive group are suppressed.

   - gh-93205(60): Fixed a bug in *note
     logging.handlers.TimedRotatingFileHandler: 1163. where multiple
     rotating handler instances pointing to files with the same name but
     different extensions would conflict and not delete the correct
     files.

   - bpo-31116(61): Add Z85 encoding to ‘base64’.

   - bpo-44865(62): Add missing call to localization function in *note
     argparse: 7.

   - bpo-43952(63): Fix *note
     multiprocessing.connection.Listener.accept(): 19c7. to accept empty
     bytes as authkey.  Not accepting empty bytes as key causes it to
     hang indefinitely.

   - bpo-42125(64): linecache: get module name from ‘__spec__’ if
     available.  This allows getting source code for the ‘__main__’
     module when a custom loader is used.

   - bpo-41122(65): Failing to pass arguments properly to *note
     functools.singledispatchmethod(): be5. now throws a TypeError
     instead of hitting an index out of bounds internally.

   - bpo-40818(66): The asyncio REPL now runs *note
     sys.__interactivehook__: 11ca. on startup.  The default
     implementation of *note sys.__interactivehook__: 11ca. provides
     auto-completion to the asyncio REPL. Patch contributed by Rémi
     Lapeyre.

   - bpo-33775(67): Add “default” and “version” help text for
     localization in argparse.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116600

   (2) https://github.com/python/cpython/issues/116349

   (3) https://github.com/python/cpython/issues/116143

   (4) https://github.com/python/cpython/issues/116127

   (5) https://peps.python.org/pep-0705/

   (6) https://github.com/python/cpython/issues/116325

   (7) https://github.com/python/cpython/issues/115957

   (8) https://github.com/python/cpython/issues/115978

   (9) https://github.com/python/cpython/issues/88352

   (10) https://github.com/python/cpython/issues/87115

   (11) https://github.com/python/cpython/issues/76511

   (12) https://github.com/python/cpython/issues/89547

   (13) https://github.com/python/cpython/issues/65824

   (14) https://github.com/python/cpython/issues/116040

   (15) https://github.com/python/cpython/issues/115821

   (16) https://github.com/python/cpython/issues/85644

   (17) https://github.com/python/cpython/issues/75988

   (18) https://github.com/python/cpython/issues/115881

   (19) https://github.com/python/cpython/issues/94949

   (20) https://github.com/python/cpython/issues/115886

   (21) https://github.com/python/cpython/issues/115532

   (22) https://github.com/python/cpython/issues/115714

   (23) https://github.com/python/cpython/issues/115809

   (24) https://github.com/python/cpython/issues/74668

   (25) https://github.com/python/cpython/issues/67044

   (26) https://github.com/python/cpython/issues/115712

   (27) https://github.com/python/cpython/issues/112364

   (28) https://github.com/python/cpython/issues/112997

   (29) https://github.com/python/cpython/issues/114914

   (30) https://github.com/python/cpython/issues/111358

   (31) https://github.com/python/cpython/issues/115618

   (32) https://github.com/python/cpython/issues/112720

   (33) https://github.com/python/cpython/issues/112006

   (34) https://github.com/python/cpython/issues/101293

   (35) https://github.com/python/cpython/issues/103092

   (36) https://peps.python.org/pep-0687/

   (37) https://github.com/python/cpython/issues/113942

   (38) https://github.com/python/cpython/issues/115256

   (39) https://github.com/python/cpython/issues/115197

   (40) https://github.com/python/cpython/issues/113812

   (41) https://github.com/python/cpython/issues/114763

   (42) https://github.com/python/cpython/issues/114709

   (43) https://github.com/python/cpython/issues/114610

   (44) https://github.com/python/cpython/issues/107361

   (45) https://github.com/python/cpython/issues/112281

   (46) https://github.com/python/cpython/issues/111775

   (47) https://github.com/python/cpython/issues/90095

   (48) https://github.com/python/cpython/issues/107625

   (49) https://github.com/python/cpython/issues/107155

   (50) https://github.com/python/cpython/issues/57141

   (51) https://github.com/python/cpython/issues/69990

   (52) https://github.com/python/cpython/issues/104061

   (53) https://github.com/python/cpython/issues/60346

   (54) https://github.com/python/cpython/issues/102389

   (55) https://github.com/python/cpython/issues/72249

   (56) https://github.com/python/cpython/issues/100985

   (57) https://github.com/python/cpython/issues/100884

   (58) https://github.com/python/cpython/issues/95782

   (59) https://github.com/python/cpython/issues/96310

   (60) https://github.com/python/cpython/issues/93205

   (61) https://bugs.python.org/issue?@action=redirect&bpo=31116

   (62) https://bugs.python.org/issue?@action=redirect&bpo=44865

   (63) https://bugs.python.org/issue?@action=redirect&bpo=43952

   (64) https://bugs.python.org/issue?@action=redirect&bpo=42125

   (65) https://bugs.python.org/issue?@action=redirect&bpo=41122

   (66) https://bugs.python.org/issue?@action=redirect&bpo=40818

   (67) https://bugs.python.org/issue?@action=redirect&bpo=33775


File: python.info,  Node: Documentation<16>,  Next: Tests<15>,  Prev: Library<59>,  Up: Python 3 13 0 alpha 5

1.24.21.8 Documentation
.......................

   - gh-115399(1): Document CVE 2023-52425(2) of Expat <2.6.0 under «XML
     vulnerabilities».

   - gh-109653(3): Improve import time of *note uuid: 116. on Linux.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115399

   (2) https://www.cve.org/CVERecord?id=CVE-2023-52425

   (3) https://github.com/python/cpython/issues/109653


File: python.info,  Node: Tests<15>,  Next: Build<18>,  Prev: Documentation<16>,  Up: Python 3 13 0 alpha 5

1.24.21.9 Tests
...............

   - gh-71052(1): Add test exclusions to support running the test suite
     on Android.

   - gh-71052(2): Enable ‘test_concurrent_futures’ on platforms that
     support threading but not multiprocessing.

   - gh-115796(3): Make “_testinternalcapi.assemble_code_object”
     construct the exception table for the code object.

   - gh-115720(4): Leak tests (‘-R’, ‘--huntrleaks’) now show a summary
     of the number of leaks found in each iteration.

   - gh-115122(5): Add ‘--bisect’ option to regrtest test runner: run
     failed tests with ‘test.bisect_cmd’ to identify failing tests.
     Patch by Victor Stinner.

   - gh-115596(6): Fix ‘ProgramPriorityTests’ in ‘test_os’ permanently
     changing the process priority.

   - gh-115556(7): On Windows, commas passed in arguments to
     ‘Tools\buildbot\test.bat’ and ‘PCbuild\\rt.bat’ are now properly
     handled.

   - gh-115420(8): Fix translation of exception handler targets by
     ‘_testinternalcapi.optimize_cfg’.

   - gh-115376(9): Fix segfault in ‘_testinternalcapi.compiler_codegen’
     on bad input.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/71052

   (2) https://github.com/python/cpython/issues/71052

   (3) https://github.com/python/cpython/issues/115796

   (4) https://github.com/python/cpython/issues/115720

   (5) https://github.com/python/cpython/issues/115122

   (6) https://github.com/python/cpython/issues/115596

   (7) https://github.com/python/cpython/issues/115556

   (8) https://github.com/python/cpython/issues/115420

   (9) https://github.com/python/cpython/issues/115376


File: python.info,  Node: Build<18>,  Next: Windows<16>,  Prev: Tests<15>,  Up: Python 3 13 0 alpha 5

1.24.21.10 Build
................

   - gh-116313(1): Get WASI builds to work under wasmtime 18 w/ WASI
     0.2/preview2 primitives.

   - gh-71052(2): Change Android’s *note sys.platform: 291. from
     ‘"linux"’ to ‘"android"’.

   - gh-116117(3): Backport ‘libb2’’s PR #42 to fix compiling CPython on
     32-bit Windows with ‘clang-cl’.

   - gh-71052(4): Fix several Android build issues

   - gh-114099(5): A testbed project was added to run the test suite on
     iOS.

   - gh-115350(6): Fix building ctypes module with -DWIN32_LEAN_AND_MEAN
     defined

   - gh-111225(7): Link extension modules against libpython on Android.

   - gh-115737(8): The install name for libPython is now correctly set
     for non-framework macOS builds.

   - gh-114099(9): Makefile targets were added to support compiling an
     iOS-compatible framework build.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116313

   (2) https://github.com/python/cpython/issues/71052

   (3) https://github.com/python/cpython/issues/116117

   (4) https://github.com/python/cpython/issues/71052

   (5) https://github.com/python/cpython/issues/114099

   (6) https://github.com/python/cpython/issues/115350

   (7) https://github.com/python/cpython/issues/111225

   (8) https://github.com/python/cpython/issues/115737

   (9) https://github.com/python/cpython/issues/114099


File: python.info,  Node: Windows<16>,  Next: macOS<9>,  Prev: Build<18>,  Up: Python 3 13 0 alpha 5

1.24.21.11 Windows
..................

   - gh-116012(1): Ensure the value of ‘GetLastError()’ is preserved
     across GIL operations.

   - gh-115582(2): Building extensions intended for free-threaded builds
     of CPython now require compiling with ‘/DPy_GIL_DISABLED’ manually
     when using a regular install.  This is expected to change in future
     releases.

   - gh-115554(3): The installer now has more strict rules about
     updating the *note Python install manager: 7db.  In general, most
     users only have a single launcher installed and will see no
     difference.  When multiple launchers have been installed, the
     option to install the launcher is disabled until all but one have
     been removed.  Downgrading the launcher (which was never allowed)
     is now more obviously blocked.

   - gh-115543(4): *note Python install manager: 7db. can now detect
     Python 3.13 when installed from the Microsoft Store, and will
     install Python 3.12 by default when ‘PYLAUNCHER_ALLOW_INSTALL’ is
     set.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116012

   (2) https://github.com/python/cpython/issues/115582

   (3) https://github.com/python/cpython/issues/115554

   (4) https://github.com/python/cpython/issues/115543


File: python.info,  Node: macOS<9>,  Next: IDLE<9>,  Prev: Windows<16>,  Up: Python 3 13 0 alpha 5

1.24.21.12 macOS
................

   - gh-116145(1): Update macOS installer to Tcl/Tk 8.6.14.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/116145


File: python.info,  Node: IDLE<9>,  Next: Tools/Demos<16>,  Prev: macOS<9>,  Up: Python 3 13 0 alpha 5

1.24.21.13 IDLE
...............

   - gh-88516(1): On macOS show a proxy icon in the title bar of editor
     windows to match platform behaviour.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/88516


File: python.info,  Node: Tools/Demos<16>,  Next: C API<18>,  Prev: IDLE<9>,  Up: Python 3 13 0 alpha 5

1.24.21.14 Tools/Demos
......................

   - gh-100176(1): Remove outdated Tools/{io,cc,string}bench

   - bpo-45101(2): Add consistency in usage message IO between 2
     versions of python-config.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100176

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45101


File: python.info,  Node: C API<18>,  Prev: Tools/Demos<16>,  Up: Python 3 13 0 alpha 5

1.24.21.15 C API
................

   - gh-114626(1): Add again ‘_PyCFunctionFastWithKeywords’ name,
     removed in Python 3.13 alpha 4 by mistake.  Keep the old private
     ‘_PyCFunctionFastWithKeywords’ name (Python 3.7) as an alias to the
     new public name ‘PyCFunctionFastWithKeywords’ (Python 3.13a4).
     Patch by Victor Stinner.

   - gh-111418(2): Add *note PyHASH_MODULUS: 19d0, *note PyHASH_BITS:
     19d1, *note PyHASH_INF: 19d2. and *note PyHASH_IMAG: 19d3. C
     macros.  Patch by Sergey B Kirpichev.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/114626

   (2) https://github.com/python/cpython/issues/111418


File: python.info,  Node: Python 3 13 0 alpha 4,  Next: Python 3 13 0 alpha 3,  Prev: Python 3 13 0 alpha 5,  Up: Changelog

1.24.22 Python 3.13.0 alpha 4
-----------------------------

'Release date: 2024-02-15'

* Menu:

* Security: Security<19>.
* Core and Builtins: Core and Builtins<55>.
* Library: Library<60>.
* Documentation: Documentation<17>.
* Tests: Tests<16>.
* Build: Build<19>.
* Windows: Windows<17>.
* macOS: macOS<10>.
* IDLE: IDLE<10>.
* Tools/Demos: Tools/Demos<17>.
* C API: C API<19>.


File: python.info,  Node: Security<19>,  Next: Core and Builtins<55>,  Up: Python 3 13 0 alpha 4

1.24.22.1 Security
..................

   - gh-115399(1): Update bundled libexpat to 2.6.0

   - gh-115243(2): Fix possible crashes in *note
     collections.deque.index(): fd2. when the deque is concurrently
     modified.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115399

   (2) https://github.com/python/cpython/issues/115243


File: python.info,  Node: Core and Builtins<55>,  Next: Library<60>,  Prev: Security<19>,  Up: Python 3 13 0 alpha 4

1.24.22.2 Core and Builtins
...........................

   - gh-112087(1): For an empty reverse iterator for list will be
     reduced to *note reversed(): a67.  Patch by Donghee Na

   - gh-114570(2): Add *note PythonFinalizationError: 479. exception.
     This exception derived from *note RuntimeError: 244. is raised when
     an operation is blocked during the *note Python finalization: 47a.
     Patch by Victor Stinner.

   - gh-114695(3): Add *note sys._clear_internal_caches(): 364, which
     clears all internal performance-related caches (and deprecate the
     less-general *note sys._clear_type_cache(): 292. function).

   - gh-114828(4): Fix compilation crashes in uncommon code examples
     using *note super(): 1a6. inside a comprehension in a class body.

   - gh-112069(5): Adapt *note set: 184. and *note frozenset: 7f3.
     methods to Argument Clinic.

   - gh-115011(6): Setters for members with an unsigned integer type now
     support the same range of valid values for objects that has a *note
     __index__(): 19e. method as for *note int: 19b.

   - gh-114887(7): Changed socket type validation in *note
     create_datagram_endpoint(): 93d. to accept all non-stream sockets.
     This fixes a regression in compatibility with raw sockets.

   - gh-114944(8): Fixes a race between ‘PyParkingLot_Park’ and
     ‘_PyParkingLot_UnparkAll’.

   - gh-113462(9): Limit the number of versions that a single class can
     use.  Prevents a few wayward classes using up all the version
     numbers.

   - gh-76763(10): The *note chr(): 19d7. builtin function now always
     raises *note ValueError: 2ec. for values outside the valid range.
     Previously it raised *note OverflowError: a83. for very large or
     small values.

   - gh-114806(11): No longer specialize calls to classes, if those
     classes have metaclasses.  Fixes bug where the ‘__call__’ method of
     the metaclass was not being called.

   - gh-107944(12): Improve error message for function calls with bad
     keyword arguments via getargs

   - gh-112529(13): The free-threaded build no longer allocates space
     for the ‘PyGC_Head’ structure in objects that support cyclic
     garbage collection.  A number of other fields and data structures
     are used as replacements, including ‘ob_gc_bits’, ‘ob_tid’, and
     mimalloc internal data structures.

   - gh-114456(14): Lower the recursion limit under a debug build of
     WASI.

   - gh-114083(15): Compiler applies folding of LOAD_CONST with
     following instruction in a separate pass before other
     optimisations.  This enables jump threading in certain
     circumstances.

   - gh-114388(16): Fix a *note RuntimeWarning: 4d8. emitted when assign
     an integer-like value that is not an instance of *note int: 19b. to
     an attribute that corresponds to a C struct member of *note type:
     19d8. T_UINT and T_ULONG. Fix a double *note RuntimeWarning: 4d8.
     emitted when assign a negative integer value to an attribute that
     corresponds to a C struct member of type T_UINT.

   - gh-114265(17): Compiler propagates line numbers before
     optimization, leading to more optimization opportunities and
     removing the need for the ‘guarantee_lineno_for_exits’ hack.

   - gh-112529(18): The free-threaded build now has its own thread-safe
     GC implementation that uses mimalloc to find GC tracked objects.
     It is non-generational, unlike the existing GC implementation.

   - gh-114050(19): Fix segmentation fault caused by an incorrect format
     string in ‘TypeError’ exception when more than two arguments are
     passed to ‘int’.

   - gh-112354(20): The ‘END_FOR’ instruction now pops only one value.
     This is to better support side exits in loops.

   - gh-113884(21): Make *note queue.SimpleQueue: d63. thread safe when
     the GIL is disabled.

   - gh-114058(22): Implement the foundations of the Tier 2 redundancy
     eliminator.

   - gh-113939(23): frame.clear(): Clear frame.f_locals as well, and not
     only the fast locals.  This is relevant once frame.f_locals was
     accessed, which would contain also references to all the locals.

   - gh-112050(24): Convert *note collections.deque: 7f5. to use
     Argument Clinic.

   - gh-112050(25): Make methods on *note collections.deque: 7f5.
     thread-safe when the GIL is disabled.

   - gh-113464(26): Add an option (‘--enable-experimental-jit’ for
     ‘configure’-based builds or ‘--experimental-jit’ for
     ‘PCbuild’-based ones) to build an 'experimental' just-in-time
     compiler, based on copy-and-patch(27)

   - gh-113055(28): Make interp->obmalloc a pointer.  For interpreters
     that share state with the main interpreter, this points to the same
     static memory structure.  For interpreters with their own obmalloc
     state, it is heap allocated.  Add free_obmalloc_arenas() which will
     free the obmalloc arenas and radix tree structures for interpreters
     with their own obmalloc state.

   - gh-55664(29): Add warning when creating *note type: f46. using a
     namespace dictionary with non-string keys.  Patched by Daniel Urban
     and Furkan Onder.

   - gh-104530(30): Use native Win32 condition variables.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/112087

   (2) https://github.com/python/cpython/issues/114570

   (3) https://github.com/python/cpython/issues/114695

   (4) https://github.com/python/cpython/issues/114828

   (5) https://github.com/python/cpython/issues/112069

   (6) https://github.com/python/cpython/issues/115011

   (7) https://github.com/python/cpython/issues/114887

   (8) https://github.com/python/cpython/issues/114944

   (9) https://github.com/python/cpython/issues/113462

   (10) https://github.com/python/cpython/issues/76763

   (11) https://github.com/python/cpython/issues/114806

   (12) https://github.com/python/cpython/issues/107944

   (13) https://github.com/python/cpython/issues/112529

   (14) https://github.com/python/cpython/issues/114456

   (15) https://github.com/python/cpython/issues/114083

   (16) https://github.com/python/cpython/issues/114388

   (17) https://github.com/python/cpython/issues/114265

   (18) https://github.com/python/cpython/issues/112529

   (19) https://github.com/python/cpython/issues/114050

   (20) https://github.com/python/cpython/issues/112354

   (21) https://github.com/python/cpython/issues/113884

   (22) https://github.com/python/cpython/issues/114058

   (23) https://github.com/python/cpython/issues/113939

   (24) https://github.com/python/cpython/issues/112050

   (25) https://github.com/python/cpython/issues/112050

   (26) https://github.com/python/cpython/issues/113464

   (27) https://fredrikbk.com/publications/copy-and-patch.pdf

   (28) https://github.com/python/cpython/issues/113055

   (29) https://github.com/python/cpython/issues/55664

   (30) https://github.com/python/cpython/issues/104530


File: python.info,  Node: Library<60>,  Next: Documentation<17>,  Prev: Core and Builtins<55>,  Up: Python 3 13 0 alpha 4

1.24.22.3 Library
.................

   - gh-115392(1): Fix a bug in *note doctest: 3e. where incorrect line
     numbers would be reported for decorated functions.

   - gh-114563(2): Fix several *note format(): 199. bugs when using the
     C implementation of *note Decimal: 1fe.: * memory leak in some rare
     cases when using the ‘z’ format option (coerce negative 0) *
     incorrect output when applying the ‘z’ format option to type ‘F’
     (fixed-point with capital ‘NAN’ / ‘INF’) * incorrect output when
     applying the ‘#’ format option (alternate form)

   - gh-102840(3): Fix confused traceback when floordiv, mod, or divmod
     operations happens between instances of *note fractions.Fraction:
     213. and *note complex: 197.

   - gh-115165(4): Most exceptions are now ignored when attempting to
     set the ‘__orig_class__’ attribute on objects returned when calling
     *note typing: 10a. generic aliases (including generic aliases
     created using *note typing.Annotated: b39.).  Previously only *note
     AttributeError: 5f0. was ignored.  Patch by Dave Shawley.

   - gh-112903(5): Fix «issubclass() arg 1 must be a class» errors in
     certain cases of multiple inheritance with generic aliases
     (regression in early 3.13 alpha releases).

   - gh-115133(6): Fix tests for *note XMLPullParser: 11f5. with Expat
     2.6.0.

   - gh-115059(7): ‘io.BufferedRandom.read1()’ now flushes the
     underlying write buffer.

   - gh-79382(8): Trailing ‘**’ no longer allows to match files and
     non-existing paths in recursive *note glob(): 5a0.

   - gh-67837(9): Avoid race conditions in the creation of directories
     during concurrent extraction in *note tarfile: e4. and *note
     zipfile: 137.

   - gh-115060(10): Speed up *note pathlib.Path.glob(): 538. by removing
     redundant regex matching.

   - gh-97928(11): Partially revert the behavior of
     ‘tkinter.Text.count()’.  By default it preserves the behavior of
     older Python versions, except that setting ‘wantobjects’ to 0 no
     longer has effect.  Add a new parameter 'return_ints': specifying
     ‘return_ints=True’ makes ‘Text.count()’ always returning the single
     count as an integer instead of a 1-tuple or ‘None’.

   - gh-114628(12): When csv.Error is raised when handling TypeError, do
     not print the TypeError traceback.

   - gh-85984(13): Added ‘_POSIX_VDISABLE’ from C’s ‘<unistd.h>’ to
     *note termios: e7.

   - gh-114965(14): Update bundled pip to 24.0

   - gh-114959(15): *note tarfile: e4. no longer ignores errors when
     trying to extract a directory on top of a file.

   - gh-114894(16): Add *note array.array.clear(): 4c1.

   - gh-114071(17): Support tuple subclasses using auto() for enum
     member value.

   - gh-109475(18): Fix support of explicit option value «–» in *note
     argparse: 7. (e.g.  ‘--option=--’).

   - gh-49766(19): Fix *note date: 1fa.-*note datetime: 4e3. comparison.
     Now the special comparison methods like ‘__eq__’ and ‘__lt__’
     return *note NotImplemented: 1a2. if one of comparands is ‘date’
     and other is ‘datetime’ instead of ignoring the time part and the
     time zone or forcefully return «not equal» or raise *note
     TypeError: 198.  It makes comparison of ‘date’ and ‘datetime’
     subclasses more symmetric and allows to change the default behavior
     by overriding the special comparison methods in subclasses.

   - gh-110190(20): Fix ctypes structs with array on Windows ARM64
     platform by setting ‘MAX_STRUCT_SIZE’ to 32 in stgdict.  Patch by
     Diego Russo

   - gh-114678(21): Ensure that deprecation warning for “N” specifier in
     *note Decimal: 1fe. format is not raised for cases where “N”
     appears in other places in the format specifier.  Based on patch by
     Stefan Krah.

   - gh-70303(22): Return both files and directories from *note
     pathlib.Path.glob(): 538. if a pattern ends with «‘**’».
     Previously only directories were returned.

   - gh-109653(23): Improve import time of *note importlib.metadata: 7e.
     and *note email.utils: 54.

   - gh-113280(24): Fix a leak of open socket in rare cases when error
     occurred in *note ssl.SSLSocket: ae9. creation.

   - gh-77749(25): *note email.policy.EmailPolicy.fold(): 19da. now
     always encodes non-ASCII characters in headers if *note utf8: ffb.
     is false.

   - gh-83383(26): Synchronization of the *note dbm.dumb: 36. database
     is now no-op if there was no modification since opening or last
     synchronization.  The directory file for a newly created empty
     *note dbm.dumb: 36. database is now created immediately after
     opening instead of deferring this until synchronizing or closing.

   - gh-91602(27): Add 'filter' keyword-only parameter to *note
     sqlite3.Connection.iterdump(): 550. for filtering database objects
     to dump.  Patch by Mariusz Felisiak.

   - gh-112451(28): Prohibit subclassing pure-Python *note
     datetime.timezone: 12c7.  This is consistent with C-extension
     implementation.  Patch by Mariusz Felisiak.

   - gh-69893(29): Add the ‘close()’ method for the iterator returned by
     *note xml.etree.ElementTree.iterparse(): 57a.

   - gh-109653(30): Reduce the import time of *note threading: f3.
     module by ~50%.  Patch by Daniel Hollas.

   - gh-114492(31): Make the result of *note termios.tcgetattr(): 19db.
     reproducible on Alpine Linux.  Previously it could leave a random
     garbage in some fields.

   - gh-114315(32): Make *note threading.Lock: 19dc. a real class, not a
     factory function.  Add ‘__new__’ to ‘_thread.lock’ type.

   - gh-100414(33): Add *note dbm.sqlite3: 39. as a backend to *note
     dbm: 35, and make it the new default ‘dbm’ backend.  Patch by
     Raymond Hettinger and Erlend E. Aasland.

   - gh-113267(34): Revert changes in gh-106584(35) which made calls of
     ‘TestResult’ methods ‘startTest()’ and ‘stopTest()’ unbalanced.

   - gh-75128(36): Ignore an *note OSError: 2c0. in
     ‘asyncio.BaseEventLoop.create_server()’ when IPv6 is available but
     the interface cannot actually support it.

   - gh-114423(37): ‘_DummyThread’ entries in ‘threading._active’ are
     now automatically removed when the related thread dies.

   - gh-114257(38): Dismiss the ‘FileNotFound’ error in *note
     ctypes.util.find_library(): f47. and just return ‘None’ on Linux.

   - gh-114321(39): Expose more platform specific constants in the *note
     fcntl: 5d. module on Linux, macOS, FreeBSD and NetBSD.

   - gh-114328(40): The *note tty.setcbreak(): 19dd. and new *note
     tty.cfmakecbreak(): 19de. no longer clears the terminal input ICRLF
     flag.  This fixes a regression introduced in 3.12 that no longer
     matched how OSes define cbreak mode in their ‘stty(1)’ manual
     pages.

   - gh-114281(41): Remove type hints from ‘Lib/asyncio/staggered.py’.
     The annotations in the typeshed(42) project should be used instead.

   - gh-101438(43): Avoid reference cycle in ElementTree.iterparse.  The
     iterator returned by ‘ElementTree.iterparse’ may hold on to a file
     descriptor.  The reference cycle prevented prompt clean-up of the
     file descriptor if the returned iterator was not exhausted.

   - gh-114198(44): The signature for the ‘__replace__’ method on *note
     dataclasses: 33. now has the first argument named ‘self’, rather
     than ‘obj’.

   - gh-104522(45): *note OSError: 2c0. raised when run a subprocess now
     only has 'filename' attribute set to 'cwd' if the error was caused
     by a failed attempt to change the current directory.

   - gh-114149(46): Enum: correctly handle tuple subclasses in custom
     ‘__new__’.

   - gh-83648(47): Support deprecation of options, positional arguments
     and subcommands in *note argparse: 7.

   - gh-114087(48): Speed up ‘dataclasses.asdict’ up to 1.35x.

   - gh-109534(49): Fix a reference leak in
     ‘asyncio.selector_events.BaseSelectorEventLoop’ when SSL handshakes
     fail.  Patch contributed by Jamie Phan.

   - gh-79634(50): Accept *note path-like objects: 5a1. as patterns in
     *note pathlib.Path.glob(): 538. and *note rglob(): 539.

   - gh-112202(51): Ensure that a *note asyncio.Condition.notify():
     19df. call does not get lost if the awakened ‘Task’ is
     simultaneously cancelled or encounters any other error.

   - gh-113951(52): Fix the behavior of ‘tag_unbind()’ methods of
     ‘tkinter.Text’ and ‘tkinter.Canvas’ classes with three arguments.
     Previously, ‘widget.tag_unbind(tag, sequence, funcid)’ destroyed
     the current binding for 'sequence', leaving 'sequence' unbound, and
     deleted the 'funcid' command.  Now it removes only 'funcid' from
     the binding for 'sequence', keeping other commands, and deletes the
     'funcid' command.  It leaves 'sequence' unbound only if 'funcid'
     was the last bound command.

   - gh-97959(53): Fix rendering class methods, bound methods, method
     and function aliases in *note pydoc: ba.  Class methods no longer
     have «method of builtins.type instance» note.  Corresponding notes
     are now added for class and unbound methods.  Method and function
     aliases now have references to the module or the class where the
     origin was defined if it differs from the current.  Bound methods
     are now listed in the static methods section.  Methods of builtin
     classes are now supported as well as methods of Python classes.

   - gh-113796(54): Add more validation checks in the *note csv.Dialect:
     180f. constructor.  *note ValueError: 2ec. is now raised if the
     same character is used in different roles.

   - gh-113732(55): Fix support of *note QUOTE_NOTNULL: 6ad. and *note
     QUOTE_STRINGS: 6ae. in *note csv.reader(): 6af.

   - gh-113225(56): Speed up *note pathlib.Path.walk(): 6d0. by using
     *note os.DirEntry.path: 19e0. where possible.

   - gh-89039(57): When replace() method is called on a subclass of
     datetime, date or time, properly call derived constructor.
     Previously, only the base class’s constructor was called.

     Also, make sure to pass non-zero fold values when creating
     subclasses in various methods.  Previously, fold was silently
     ignored.

   - gh-112919(58): Speed-up *note datetime.datetime.replace(): 16d2,
     *note datetime.date.replace(): 19e1. and *note
     datetime.time.replace(): 19e2.

   - gh-59013(59): Set breakpoint on the first executable line of the
     function, instead of the line of function definition when the user
     do ‘break func’ using *note pdb: aa.

   - gh-112343(60): Improve handling of pdb convenience variables to
     avoid replacing string contents.

   - gh-112240(61): Add option to calendar module CLI to specify the
     weekday to start each week.  Patch by Steven Ward.

   - gh-111741(62): Recognise ‘image/webp’ as a standard format in the
     *note mimetypes: 93. module.

   - gh-43457(63): Fix the *note tkinter: f6. widget method
     ‘wm_attributes()’.  It now accepts the attribute name without the
     minus prefix to get window attributes and allows to specify
     attributes and values to set as keyword arguments.  Add new
     optional keyword argument 'return_python_dict': calling
     ‘w.wm_attributes(return_python_dict=True)’ returns the attributes
     as a dict instead of a tuple.  Calling ‘w.wm_attributes()’ now
     returns a tuple instead of string if 'wantobjects' was set to 0.

   - gh-82626(64): Many functions now emit a warning if a boolean value
     is passed as a file descriptor argument.

   - gh-111051(65): Added check for file modification during debugging
     with *note pdb: aa.

   - gh-110345(66): Show the Tcl/Tk patchlevel (rather than version) in
     ‘tkinter._test()’.

   - gh-38807(67): Fix race condition in *note trace: 103.  Instead of
     checking if a directory exists and creating it, directly call *note
     os.makedirs(): 52d. with the kwarg ‘exist_ok=True’.

   - gh-75705(68): Set unixfrom envelope in *note mailbox.mbox: 19e3.
     and *note mailbox.MMDF: 19e4.

   - gh-106233(69): Fix stacklevel in ‘InvalidTZPathWarning’ during
     *note zoneinfo: 13a. module import.

   - gh-105102(70): Allow *note ctypes.Union: 1e6. to be nested in *note
     ctypes.Structure: 1e5. when the system endianness is the opposite
     of the classes.

   - gh-104282(71): Fix null pointer dereference in
     ‘lzma._decode_filter_properties()’ due to improper handling of BCJ
     filters with properties of zero length.  Patch by Radislav
     Chugunov.

   - gh-96471(72): Add *note queue.Queue: 159c. termination with *note
     shutdown(): 543.

   - gh-101599(73): Changed argparse flag options formatting to remove
     redundancy.

   - gh-85984(74): Add POSIX pseudo-terminal functions *note
     os.posix_openpt(): 19e5, *note os.grantpt(): 19e6, *note
     os.unlockpt(): 19e7, and *note os.ptsname(): 19e8.

   - gh-102512(75): When *note os.fork(): 4b6. is called from a foreign
     thread (aka ‘_DummyThread’), the type of the thread in a child
     process is changed to ‘_MainThread’.  Also changed its name and
     daemonic status, it can be now joined.

   - gh-88569(76): Add *note os.path.isreserved(): 32b, which identifies
     reserved pathnames such as «NUL», «AUX» and «CON».  This function
     is only available on Windows.

     Deprecate *note pathlib.PurePath.is_reserved(): 32a.

   - bpo-38364(77): The ‘inspect’ functions ‘isgeneratorfunction’,
     ‘iscoroutinefunction’, ‘isasyncgenfunction’ now support
     ‘functools.partialmethod’ wrapped functions the same way they
     support ‘functools.partial’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115392

   (2) https://github.com/python/cpython/issues/114563

   (3) https://github.com/python/cpython/issues/102840

   (4) https://github.com/python/cpython/issues/115165

   (5) https://github.com/python/cpython/issues/112903

   (6) https://github.com/python/cpython/issues/115133

   (7) https://github.com/python/cpython/issues/115059

   (8) https://github.com/python/cpython/issues/79382

   (9) https://github.com/python/cpython/issues/67837

   (10) https://github.com/python/cpython/issues/115060

   (11) https://github.com/python/cpython/issues/97928

   (12) https://github.com/python/cpython/issues/114628

   (13) https://github.com/python/cpython/issues/85984

   (14) https://github.com/python/cpython/issues/114965

   (15) https://github.com/python/cpython/issues/114959

   (16) https://github.com/python/cpython/issues/114894

   (17) https://github.com/python/cpython/issues/114071

   (18) https://github.com/python/cpython/issues/109475

   (19) https://github.com/python/cpython/issues/49766

   (20) https://github.com/python/cpython/issues/110190

   (21) https://github.com/python/cpython/issues/114678

   (22) https://github.com/python/cpython/issues/70303

   (23) https://github.com/python/cpython/issues/109653

   (24) https://github.com/python/cpython/issues/113280

   (25) https://github.com/python/cpython/issues/77749

   (26) https://github.com/python/cpython/issues/83383

   (27) https://github.com/python/cpython/issues/91602

   (28) https://github.com/python/cpython/issues/112451

   (29) https://github.com/python/cpython/issues/69893

   (30) https://github.com/python/cpython/issues/109653

   (31) https://github.com/python/cpython/issues/114492

   (32) https://github.com/python/cpython/issues/114315

   (33) https://github.com/python/cpython/issues/100414

   (34) https://github.com/python/cpython/issues/113267

   (35) https://github.com/python/cpython/issues/106584

   (36) https://github.com/python/cpython/issues/75128

   (37) https://github.com/python/cpython/issues/114423

   (38) https://github.com/python/cpython/issues/114257

   (39) https://github.com/python/cpython/issues/114321

   (40) https://github.com/python/cpython/issues/114328

   (41) https://github.com/python/cpython/issues/114281

   (42) https://github.com/python/typeshed

   (43) https://github.com/python/cpython/issues/101438

   (44) https://github.com/python/cpython/issues/114198

   (45) https://github.com/python/cpython/issues/104522

   (46) https://github.com/python/cpython/issues/114149

   (47) https://github.com/python/cpython/issues/83648

   (48) https://github.com/python/cpython/issues/114087

   (49) https://github.com/python/cpython/issues/109534

   (50) https://github.com/python/cpython/issues/79634

   (51) https://github.com/python/cpython/issues/112202

   (52) https://github.com/python/cpython/issues/113951

   (53) https://github.com/python/cpython/issues/97959

   (54) https://github.com/python/cpython/issues/113796

   (55) https://github.com/python/cpython/issues/113732

   (56) https://github.com/python/cpython/issues/113225

   (57) https://github.com/python/cpython/issues/89039

   (58) https://github.com/python/cpython/issues/112919

   (59) https://github.com/python/cpython/issues/59013

   (60) https://github.com/python/cpython/issues/112343

   (61) https://github.com/python/cpython/issues/112240

   (62) https://github.com/python/cpython/issues/111741

   (63) https://github.com/python/cpython/issues/43457

   (64) https://github.com/python/cpython/issues/82626

   (65) https://github.com/python/cpython/issues/111051

   (66) https://github.com/python/cpython/issues/110345

   (67) https://github.com/python/cpython/issues/38807

   (68) https://github.com/python/cpython/issues/75705

   (69) https://github.com/python/cpython/issues/106233

   (70) https://github.com/python/cpython/issues/105102

   (71) https://github.com/python/cpython/issues/104282

   (72) https://github.com/python/cpython/issues/96471

   (73) https://github.com/python/cpython/issues/101599

   (74) https://github.com/python/cpython/issues/85984

   (75) https://github.com/python/cpython/issues/102512

   (76) https://github.com/python/cpython/issues/88569

   (77) https://bugs.python.org/issue?@action=redirect&bpo=38364


File: python.info,  Node: Documentation<17>,  Next: Tests<16>,  Prev: Library<60>,  Up: Python 3 13 0 alpha 4

1.24.22.4 Documentation
.......................

   - gh-115233(1): Fix an example for *note LoggerAdapter: 14fd. in the
     Logging Cookbook.

   - gh-114123(2): Move the *note csv: 2d. module docstring to the ‘csv’
     module instead of reexporting it from the internal ‘_csv’ module,
     and remove ‘__doc__’ from ‘csv.__all__’.

     Move ‘csv.__version__’ to the ‘csv’ module instead of reexporting
     it from the internal ‘_csv’ module, and remove ‘__version__’ from
     ‘csv.__all__’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115233

   (2) https://github.com/python/cpython/issues/114123


File: python.info,  Node: Tests<16>,  Next: Build<19>,  Prev: Documentation<17>,  Up: Python 3 13 0 alpha 4

1.24.22.5 Tests
...............

   - gh-114099(1): Added test exclusions required to run the test suite
     on iOS.

   - gh-105089(2): Fix
     ‘test.test_zipfile.test_core.TestWithDirectory.test_create_directory_with_write’
     test in AIX by doing a bitwise AND of 0xFFFF on mode , so that it
     will be in sync with ‘zinfo.external_attr’

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/114099

   (2) https://github.com/python/cpython/issues/105089


File: python.info,  Node: Build<19>,  Next: Windows<17>,  Prev: Tests<16>,  Up: Python 3 13 0 alpha 4

1.24.22.6 Build
...............

   - gh-115167(1): Avoid vendoring ‘vcruntime140_threads.dll’ when
     building with Visual Studio 2022 version 17.8.

   - gh-113632(2): Promote WASI to a tier 2 platform and drop Emscripten
     from tier 3 in configure.ac.

   - gh-114099(3): configure and Makefile were refactored to accommodate
     framework builds on Apple platforms other than macOS.

   - gh-114875(4): Add ‘getgrent()’ as a prerequisite for building the
     *note grp: 6a. module.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115167

   (2) https://github.com/python/cpython/issues/113632

   (3) https://github.com/python/cpython/issues/114099

   (4) https://github.com/python/cpython/issues/114875


File: python.info,  Node: Windows<17>,  Next: macOS<10>,  Prev: Build<19>,  Up: Python 3 13 0 alpha 4

1.24.22.7 Windows
.................

   - gh-115049(1): Fixes ‘py.exe’ launcher failing when run as users
     without user profiles.

   - gh-115009(2): Update Windows installer to use SQLite 3.45.1.

   - gh-109991(3): Update Windows build to use OpenSSL 3.0.13.

   - gh-111239(4): Update Windows builds to use zlib v1.3.1.

   - gh-100107(5): The ‘py.exe’ launcher will no longer attempt to run
     the Microsoft Store redirector when launching a script containing a
     ‘/usr/bin/env’ shebang

   - gh-112984(6): Adds free-threaded binaries to Windows installer as
     an optional component.

   - gh-89240(7): Allows *note multiprocessing: 98. to create pools of
     greater than 62 processes.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115049

   (2) https://github.com/python/cpython/issues/115009

   (3) https://github.com/python/cpython/issues/109991

   (4) https://github.com/python/cpython/issues/111239

   (5) https://github.com/python/cpython/issues/100107

   (6) https://github.com/python/cpython/issues/112984

   (7) https://github.com/python/cpython/issues/89240


File: python.info,  Node: macOS<10>,  Next: IDLE<10>,  Prev: Windows<17>,  Up: Python 3 13 0 alpha 4

1.24.22.8 macOS
...............

   - gh-115009(1): Update macOS installer to use SQLite 3.45.1.

   - gh-109991(2): Update macOS installer to use OpenSSL 3.0.13.

   - gh-114490(3): Add Mach-O linkage support for *note
     platform.architecture(): 19ee.

   - gh-87804(4): On macOS the result of ‘os.statvfs’ and ‘os.fstatvfs’
     now correctly report the size of very large disks, in previous
     versions the reported number of blocks was wrong for disks with at
     least 2**32 blocks.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115009

   (2) https://github.com/python/cpython/issues/109991

   (3) https://github.com/python/cpython/issues/114490

   (4) https://github.com/python/cpython/issues/87804


File: python.info,  Node: IDLE<10>,  Next: Tools/Demos<17>,  Prev: macOS<10>,  Up: Python 3 13 0 alpha 4

1.24.22.9 IDLE
..............

   - gh-96905(1): In idlelib code, stop redefining built-ins “dict” and
     “object”.

   - gh-103820(2): Revise IDLE bindings so that events from mouse button
     4/5 on non-X11 windowing systems (i.e.  Win32 and Aqua) are not
     mistaken for scrolling.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/96905

   (2) https://github.com/python/cpython/issues/103820


File: python.info,  Node: Tools/Demos<17>,  Next: C API<19>,  Prev: IDLE<10>,  Up: Python 3 13 0 alpha 4

1.24.22.10 Tools/Demos
......................

   - gh-113516(1): Don’t set ‘LDSHARED’ when building for WASI.

   - gh-109991(2): Update GitHub CI workflows to use OpenSSL 3.0.13 and
     multissltests to use 1.1.1w, 3.0.13, 3.1.5, and 3.2.1.

   - gh-115015(3): Fix a bug in Argument Clinic that generated incorrect
     code for methods with no parameters that use the *note METH_METHOD
     | METH_FASTCALL | METH_KEYWORDS: 19f1. calling convention.  Only
     the positional parameter count was checked; any keyword argument
     passed would be silently accepted.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/113516

   (2) https://github.com/python/cpython/issues/109991

   (3) https://github.com/python/cpython/issues/115015


File: python.info,  Node: C API<19>,  Prev: Tools/Demos<17>,  Up: Python 3 13 0 alpha 4

1.24.22.11 C API
................

   - gh-111140(1): Adds *note PyLong_AsNativeBytes(): 606, *note
     PyLong_FromNativeBytes(): 607. and *note
     PyLong_FromUnsignedNativeBytes(): 608. functions.

   - gh-114685(2): *note PyBuffer_FillInfo(): 965. now raises a *note
     SystemError: 796. if called with *note PyBUF_READ: 19f3. or *note
     PyBUF_WRITE: 19f4. as flags.  These flags should only be used with
     the ‘PyMemoryView_*’ C API.

   - gh-114685(3): *note PyObject_GetBuffer(): 63a. now raises a *note
     SystemError: 796. if called with *note PyBUF_READ: 19f3. or *note
     PyBUF_WRITE: 19f4. as flags.  These flags should only be used with
     the ‘PyMemoryView_*’ C API.

   - gh-114626(4): Add ‘PyCFunctionFast’ and
     ‘PyCFunctionFastWithKeywords’ typedefs (identical to the existing
     ‘_PyCFunctionFast’ and ‘_PyCFunctionFastWithKeywords’ typedefs,
     just without a leading ‘_’ prefix).

   - gh-114329(5): Add *note PyList_GetItemRef(): 5fe, which is similar
     to *note PyList_GetItem(): 5ff. but returns a *note strong
     reference: 5e2. instead of a *note borrowed reference: 3d7.

   - gh-110850(6): Add PyTime C API:

        * *note PyTime_t: 5d3. type.

        * *note PyTime_MIN: 5d4. and *note PyTime_MAX: 5d5. constants.

        * *note PyTime_AsSecondsDouble(): 5d6, *note PyTime_Monotonic():
          5d7, *note PyTime_PerfCounter(): 5d9, and *note PyTime_Time():
          5db. functions.

     Patch by Victor Stinner.

   - gh-112066(7): Add *note PyDict_SetDefaultRef(): 5e3.: insert a key
     and value into a dictionary if the key is not already present.
     This is similar to *note dict.setdefault(): 127b, but returns an
     integer value indicating if the key was already present.  It is
     also similar to *note PyDict_SetDefault(): 5e4, but returns a
     strong reference instead of a borrowed reference.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/111140

   (2) https://github.com/python/cpython/issues/114685

   (3) https://github.com/python/cpython/issues/114685

   (4) https://github.com/python/cpython/issues/114626

   (5) https://github.com/python/cpython/issues/114329

   (6) https://github.com/python/cpython/issues/110850

   (7) https://github.com/python/cpython/issues/112066


File: python.info,  Node: Python 3 13 0 alpha 3,  Next: Python 3 13 0 alpha 2,  Prev: Python 3 13 0 alpha 4,  Up: Changelog

1.24.23 Python 3.13.0 alpha 3
-----------------------------

'Release date: 2024-01-17'

* Menu:

* Security: Security<20>.
* Core and Builtins: Core and Builtins<56>.
* Library: Library<61>.
* Documentation: Documentation<18>.
* Tests: Tests<17>.
* Build: Build<20>.
* Windows: Windows<18>.
* macOS: macOS<11>.
* IDLE: IDLE<11>.
* C API: C API<20>.


File: python.info,  Node: Security<20>,  Next: Core and Builtins<56>,  Up: Python 3 13 0 alpha 3

1.24.23.1 Security
..................

   - gh-113659(1): Skip ‘.pth’ files with names starting with a dot or
     hidden file attribute.

   - gh-112302(2): Created a Software Bill-of-Materials document and
     tooling for tracking dependencies.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/113659

   (2) https://github.com/python/cpython/issues/112302


File: python.info,  Node: Core and Builtins<56>,  Next: Library<61>,  Prev: Security<20>,  Up: Python 3 13 0 alpha 3

1.24.23.2 Core and Builtins
...........................

   - gh-107901(1): Compiler duplicates basic blocks that have an eval
     breaker check, no line number, and multiple predecessors.

   - gh-107901(2): A jump leaving an exception handler back to normal
     code no longer checks the eval breaker.

   - gh-113655(3): Set the C recursion limit to 4000 on Windows, and
     10000 on Linux/OSX. This seems to be near the sweet spot to
     maintain safety, but not compromise backwards compatibility.

   - gh-113710(4): Add typed stack effects to the interpreter DSL, along
     with various instruction annotations.

   - gh-77046(5): On Windows, file descriptors wrapping Windows handles
     are now created non inheritable by default ( PEP 446(6)).  Patch by
     Zackery Spytz and Victor Stinner.

   - gh-113853(7): Guarantee that all executors make progress.  This
     then guarantees that tier 2 execution always makes progress.

   - gh-113753(8): Fix an issue where the finalizer of ‘PyAsyncGenASend’
     objects might not be called if they were allocated from a free
     list.

   - gh-107901(9): Compiler changed so that synthetic jumps which are
     not at loop end no longer check the eval breaker.

   - gh-113703(10): Fix a regression in the *note codeop: 1d. module
     that was causing it to incorrectly identify incomplete f-strings.
     Patch by Pablo Galindo

   - gh-89811(11): Check for a valid ‘tp_version_tag’ before performing
     bytecode specializations that rely on this value being usable.

   - gh-111488(12): Changed error message in case of no “in” keyword
     after “for” in list comprehensions

   - gh-113657(13): Fix an issue that caused important instruction
     pointer updates to be optimized out of tier two traces.

   - gh-113603(14): Fixed bug where a redundant NOP is not removed,
     causing an assertion to fail in the compiler in debug mode.

   - gh-113602(15): Fix an error that was causing the parser to try to
     overwrite existing errors and crashing in the process.  Patch by
     Pablo Galindo

   - gh-113486(16): No longer issue spurious ‘PY_UNWIND’ events for
     optimized calls to classes.

   - gh-113297(17): Fix segfault in the compiler on with statement with
     19 context managers.

   - gh-113212(18): Improve *note super: 1a6. error messages.

   - gh-111375(19): Only use ‘NULL’ in the exception stack to indicate
     an exception was handled.  Patch by Carey Metcalfe.

   - gh-112215(20): Increase the C recursion limit by a factor of 3 for
     non-debug builds, except for webassembly and s390 platforms which
     are unchanged.  This mitigates some regressions in 3.12 with deep
     recursion mixing builtin (C) and Python code.

   - gh-113054(21): Fixed bug where a redundant NOP is not removed,
     causing an assertion to fail in the compiler in debug mode.

   - gh-106905(22): Use per AST-parser state rather than global state to
     track recursion depth within the AST parser to prevent potential
     race condition due to simultaneous parsing.

     The issue primarily showed up in 3.11 by multithreaded users of
     *note ast.parse(): 1c2.  In 3.12 a change to when garbage
     collection can be triggered prevented the race condition from
     occurring.

   - gh-108866(23): Change the API and contract of ‘_PyExecutorObject’
     to return the next_instr pointer, instead of the frame, and to
     always execute at least one instruction.

   - gh-90350(24): Optimize builtin functions *note min(): 110d. and
     *note max(): 110e.

   - gh-112943(25): Correctly compute end column offsets for multiline
     tokens in the *note tokenize: 101. module.  Patch by Pablo Galindo

   - gh-112125(26): Fix ‘None.__ne__(None)’ returning ‘NotImplemented’
     instead of ‘False’.

   - gh-74616(27): *note input(): 14e0. now raises a ValueError when
     output on the terminal if the prompt contains embedded null
     characters instead of silently truncating it.

   - gh-112716(28): Fix SystemError in the ‘import’ statement and in
     ‘__reduce__()’ methods of builtin types when ‘__builtins__’ is not
     a dict.

   - gh-112730(29): Use color to highlight error locations in
     tracebacks.  Patch by Pablo Galindo

   - gh-112625(30): Fixes a bug where a bytearray object could be
     cleared while iterating over an argument in the ‘bytearray.join()’
     method that could result in reading memory after it was freed.

   - gh-112660(31): Do not clear unexpected errors during formatting
     error messages for ImportError and AttributeError for modules.

   - gh-105967(32): Workaround a bug in Apple’s macOS platform zlib
     library where *note zlib.crc32(): 19f8. and *note binascii.crc32():
     19f9. could produce incorrect results on multi-gigabyte inputs.
     Including when using *note zipfile: 137. on zips containing large
     data.

   - gh-95754(33): Provide a better error message when accessing invalid
     attributes on partially initialized modules.  The origin of the
     module being accessed is now included in the message to help with
     the common issue of shadowing other modules.

   - gh-112217(34): Add check for the type of ‘__cause__’ returned from
     calling the type ‘T’ in ‘raise from T’.

   - gh-111058(35): Change coro.cr_frame/gen.gi_frame to return ‘None’
     after the coroutine/generator has been closed.  This fixes a bug
     where *note getcoroutinestate(): 101c. and *note
     getgeneratorstate(): 143e. return the wrong state for a closed
     coroutine/generator.

   - gh-112388(36): Fix an error that was causing the parser to try to
     overwrite tokenizer errors.  Patch by pablo Galindo

   - gh-112387(37): Fix error positions for decoded strings with
     backwards tokenize errors.  Patch by Pablo Galindo

   - gh-99606(38): Make code generated for an empty f-string identical
     to the code of an empty normal string.

   - gh-112367(39): Avoid undefined behaviour when using the perf
     trampolines by not freeing the code arenas until shutdown.  Patch
     by Pablo Galindo

   - gh-112320(40): The Tier 2 translator now tracks the confidence
     level for staying «on trace» (i.e.  not exiting back to the Tier 1
     interpreter) for branch instructions based on the number of bits
     set in the branch «counter».  Trace translation ends when the
     confidence drops below 1/3rd.

   - gh-109598(41): *note PyComplex_RealAsDouble(): 19fa./*note
     PyComplex_ImagAsDouble(): 19fb. now tries to convert an object to a
     *note complex: 197. instance using its ‘__complex__()’ method
     before falling back to the ‘__float__()’ method.  Patch by Sergey B
     Kirpichev.

   - gh-94606(42): Fix UnicodeEncodeError when
     ‘email.message.get_payload()’ reads a message with a Unicode
     surrogate character and the message content is not well-formed for
     surrogateescape encoding.  Patch by Sidney Markowitz.

   - bpo-21861(43): Use the object’s actual class name in
     ‘_io.FileIO.__repr__()’, ‘_io._WindowsConsoleIO()’ and
     ‘_io.TextIOWrapper.__repr__()’, to make these methods subclass
     friendly.

   - bpo-45369(44): Remove LibreSSL workarounds as per PEP 644(45).

   - bpo-34392(46): Added *note sys._is_interned(): 559.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/107901

   (2) https://github.com/python/cpython/issues/107901

   (3) https://github.com/python/cpython/issues/113655

   (4) https://github.com/python/cpython/issues/113710

   (5) https://github.com/python/cpython/issues/77046

   (6) https://peps.python.org/pep-0446/

   (7) https://github.com/python/cpython/issues/113853

   (8) https://github.com/python/cpython/issues/113753

   (9) https://github.com/python/cpython/issues/107901

   (10) https://github.com/python/cpython/issues/113703

   (11) https://github.com/python/cpython/issues/89811

   (12) https://github.com/python/cpython/issues/111488

   (13) https://github.com/python/cpython/issues/113657

   (14) https://github.com/python/cpython/issues/113603

   (15) https://github.com/python/cpython/issues/113602

   (16) https://github.com/python/cpython/issues/113486

   (17) https://github.com/python/cpython/issues/113297

   (18) https://github.com/python/cpython/issues/113212

   (19) https://github.com/python/cpython/issues/111375

   (20) https://github.com/python/cpython/issues/112215

   (21) https://github.com/python/cpython/issues/113054

   (22) https://github.com/python/cpython/issues/106905

   (23) https://github.com/python/cpython/issues/108866

   (24) https://github.com/python/cpython/issues/90350

   (25) https://github.com/python/cpython/issues/112943

   (26) https://github.com/python/cpython/issues/112125

   (27) https://github.com/python/cpython/issues/74616

   (28) https://github.com/python/cpython/issues/112716

   (29) https://github.com/python/cpython/issues/112730

   (30) https://github.com/python/cpython/issues/112625

   (31) https://github.com/python/cpython/issues/112660

   (32) https://github.com/python/cpython/issues/105967

   (33) https://github.com/python/cpython/issues/95754

   (34) https://github.com/python/cpython/issues/112217

   (35) https://github.com/python/cpython/issues/111058

   (36) https://github.com/python/cpython/issues/112388

   (37) https://github.com/python/cpython/issues/112387

   (38) https://github.com/python/cpython/issues/99606

   (39) https://github.com/python/cpython/issues/112367

   (40) https://github.com/python/cpython/issues/112320

   (41) https://github.com/python/cpython/issues/109598

   (42) https://github.com/python/cpython/issues/94606

   (43) https://bugs.python.org/issue?@action=redirect&bpo=21861

   (44) https://bugs.python.org/issue?@action=redirect&bpo=45369

   (45) https://peps.python.org/pep-0644/

   (46) https://bugs.python.org/issue?@action=redirect&bpo=34392


File: python.info,  Node: Library<61>,  Next: Documentation<18>,  Prev: Core and Builtins<56>,  Up: Python 3 13 0 alpha 3

1.24.23.3 Library
.................

   - gh-114077(1): Fix possible *note OverflowError: a83. in *note
     socket.socket.sendfile(): 105f. when pass 'count' larger than 2 GiB
     on 32-bit platform.

   - gh-111803(2): *note plistlib: b0. now supports loading more deeply
     nested lists in binary format.

   - gh-114014(3): Fixed a bug in *note fractions.Fraction: 213. where
     an invalid string using ‘d’ in the decimals part creates a
     different error compared to other invalid letters/characters.
     Patch by Jeremiah Gabriel Pascual.

   - gh-108364(4): *note sqlite3.Connection.iterdump(): 550. now ensures
     that foreign key support is disabled before dumping the database
     schema, if there is any foreign key violation.  Patch by Erlend E.
     Aasland and Mariusz Felisiak.

   - gh-113971(5): The *note zipfile.ZipInfo: 2cb. previously protected
     ‘._compresslevel’ attribute has been made public as
     ‘.compress_level’ with the old ‘_compresslevel’ name remaining
     available as a property to retain compatibility.

   - gh-113877(6): Fix *note tkinter: f6. method ‘winfo_pathname()’ on
     64-bit Windows.

   - gh-113868(7): Added *note mmap.MAP_NORESERVE: 19fd, *note
     mmap.MAP_NOEXTEND: 19fe, *note mmap.MAP_HASSEMAPHORE: 19ff, *note
     mmap.MAP_NOCACHE: 1a00, *note mmap.MAP_JIT: 1a01, *note
     mmap.MAP_RESILIENT_CODESIGN: 1a02, *note mmap.MAP_RESILIENT_MEDIA:
     1a03, *note mmap.MAP_32BIT: 1a04, *note
     mmap.MAP_TRANSLATED_ALLOW_EXECUTE: 1a05, *note mmap.MAP_UNIX03:
     1a06. and *note mmap.MAP_TPRO: 1a07.  All of them are ‘mmap(2)’
     flags on macOS.

   - gh-113848(8): *note asyncio.TaskGroup(): 4d2. and *note
     asyncio.timeout(): 815. context managers now handle *note
     CancelledError: 4d5. subclasses as well as exact ‘CancelledError’.

   - gh-113661(9): unittest runner: Don’t exit 5 if tests were skipped.
     The intention of exiting 5 was to detect issues where the test
     suite wasn’t discovered at all.  If we skipped tests, it was
     correctly discovered.

   - gh-96037(10): Insert *note TimeoutError: a38. in the context of the
     exception that was raised during exiting an expired *note
     asyncio.timeout(): 815. block.

   - gh-113781(11): Silence unraisable AttributeError when warnings are
     emitted during Python finalization.

   - gh-113238(12): Add ‘Anchor’ to ‘importlib.resources’ (in order for
     the code to comply with the documentation)

   - gh-111693(13): *note asyncio.Condition.wait(): 1a08. now re-raises
     the same ‘CancelledError’ instance that may have caused it to be
     interrupted.  Fixed race condition in *note
     asyncio.Semaphore.acquire(): 1a09. when interrupted with a
     ‘CancelledError’.

   - gh-113791(14): Add ‘CLOCK_MONOTONIC_RAW_APPROX’ and
     ‘CLOCK_UPTIME_RAW_APPROX’ to *note time: f4. on macOS. These are
     clocks available on macOS 10.12 or later.

   - gh-112932(15): Restore the ability for *note zipfile: 137. to
     ‘extractall’ from zip files with a «/» directory entry in them as
     is commonly added to zips by some wiki or bug tracker data
     exporters.

   - gh-113568(16): Raise deprecation warnings from *note
     pathlib.PurePath: 6ce. and not its private base class
     ‘PurePathBase’.

   - gh-113594(17): Fix *note UnicodeEncodeError: 888. in *note email:
     3f. when re-fold lines that contain unknown-8bit encoded part
     followed by non-unknown-8bit encoded part.

   - gh-113538(18): In ‘asyncio.StreamReaderProtocol.connection_made()’,
     there is callback that logs an error if the task wrapping the
     «connected callback» fails.  This callback would itself fail if the
     task was cancelled.  Prevent this by checking whether the task was
     cancelled first.  If so, close the transport but don’t log an
     error.

   - gh-113626(19): Add support for the 'allow_code' argument in the
     *note marshal: 91. module.  Passing ‘allow_code=False’ prevents
     serialization and de-serialization of code objects which is
     incompatible between Python versions.

   - gh-85567(20): Fix resource warnings for unclosed files in *note
     pickle: ab. and *note pickletools: ac. command line interfaces.

   - gh-113537(21): Support loads ‘str’ in *note plistlib.loads(): b4b.

   - gh-89850(22): Add default implementations of *note
     pickle.Pickler.persistent_id(): 18f4. and *note
     pickle.Unpickler.persistent_load(): 18fc. methods in the C
     implementation.  Calling ‘super().persistent_id()’ and
     ‘super().persistent_load()’ in subclasses of the C implementation
     of *note pickle.Pickler: c15. and *note pickle.Unpickler: 175e.
     classes no longer causes infinite recursion.

   - gh-113569(23): Indicate if there were no actual calls in unittest
     *note assert_has_calls(): 1a0a. failure.

   - gh-101225(24): Increase the backlog for *note
     multiprocessing.connection.Listener: 1a0b. objects created by
     ‘multiprocessing.manager’ and ‘multiprocessing.resource_sharer’ to
     significantly reduce the risk of getting a connection refused error
     when creating a *note multiprocessing.connection.Connection: 12e8.
     to them.

   - gh-113568(25): Raise audit events from *note pathlib.Path: 266. and
     not its private base class ‘PathBase’.

   - gh-113543(26): Make sure that ‘webbrowser.MacOSXOSAScript’ sends
     ‘webbrowser.open’ audit event.

   - gh-113028(27): When a second reference to a string appears in the
     input to *note pickle: ab, and the Python implementation is in use,
     we are guaranteed that a single copy gets pickled and a single
     object is shared when reloaded.  Previously, in protocol 0, when a
     string contained certain characters (e.g.  newline) it resulted in
     duplicate objects.

   - gh-113421(28): Fix multiprocessing logger for ‘%(filename)s’.

   - gh-111784(29): Fix segfaults in the ‘_elementtree’ module.  Fix
     first segfault during deallocation of ‘_elementtree.XMLParser’
     instances by keeping strong reference to ‘pyexpat’ module in module
     state for capsule lifetime.  Fix second segfault which happens in
     the same deallocation process by keeping strong reference to
     ‘_elementtree’ module in ‘XMLParser’ structure for ‘_elementtree’
     module lifetime.

   - gh-113407(30): Fix import of *note unittest.mock: 10d. when CPython
     is built without docstrings.

   - gh-113320(31): Fix regression in Python 3.12 where *note Protocol:
     56b. classes that were not marked as *note runtime-checkable: 675.
     would be unnecessarily introspected, potentially causing exceptions
     to be raised if the protocol had problematic members.  Patch by
     Alex Waygood.

   - gh-53502(32): Add a new option ‘aware_datetime’ in *note plistlib:
     b0. to loads or dumps aware datetime.

   - gh-113358(33): Fix rendering tracebacks with exceptions with a
     broken __getattr__

   - gh-113214(34): Fix an ‘AttributeError’ during asyncio SSL protocol
     aborts in SSL-over-SSL scenarios.

   - gh-113246(35): Update bundled pip to 23.3.2.

   - gh-87264(36): Fixed tarfile list() method to show file type.

   - gh-112182(37): ‘asyncio.futures.Future.set_exception()’ now
     transforms *note StopIteration: df7. into *note RuntimeError: 244.
     instead of hanging or other misbehavior.  Patch contributed by
     Jamie Phan.

   - gh-113225(38): Speed up *note pathlib.Path.glob(): 538. by using
     *note os.DirEntry.path: 19e0. where possible.

   - gh-113149(39): Improve error message when a JSON array or object
     contains a trailing comma.  Patch by Carson Radtke.

   - gh-113117(40): The *note subprocess: dc. module can now use the
     *note os.posix_spawn(): 52f. function with ‘close_fds=True’ on
     platforms where ‘posix_spawn_file_actions_addclosefrom_np’ is
     available.  Patch by Jakub Kulik.

   - gh-113199(41): Make ‘http.client.HTTPResponse.read1’ and
     ‘http.client.HTTPResponse.readline’ close IO after reading all data
     when content length is known.  Patch by Illia Volochii.

   - gh-113191(42): Add support of *note os.fchmod(): 52b. and a file
     descriptor in *note os.chmod(): 52a. on Windows.

   - gh-113188(43): Fix *note shutil.copymode(): 1a0c. and *note
     shutil.copystat(): 1336. on Windows.  Previously they worked
     differently if 'dst' is a symbolic link: they modified the
     permission bits of 'dst' itself rather than the file it points to
     if 'follow_symlinks' is true or 'src' is not a symbolic link, and
     did not modify the permission bits if 'follow_symlinks' is false
     and 'src' is a symbolic link.

   - gh-113119(44): *note os.posix_spawn(): 52f. now accepts ‘env=None’,
     which makes the newly spawned process use the current process
     environment.  Patch by Jakub Kulik.

   - gh-113202(45): Add a ‘strict’ option to ‘batched()’ in the
     ‘itertools’ module.

   - gh-61648(46): Detect line numbers of properties in doctests.

   - gh-113175(47): Sync with importlib_metadata 7.0, including improved
     type annotations, fixed issue with symlinked packages in
     ‘package_distributions’, added ‘EntryPoints.__repr__’, introduced
     the ‘diagnose’ script, added ‘Distribution.origin’ property, and
     removed deprecated ‘EntryPoint’ access by numeric index (tuple
     behavior).

   - gh-59616(48): Add support of *note os.lchmod(): 529. and the
     'follow_symlinks' argument in *note os.chmod(): 52a. on Windows.
     Note that the default value of 'follow_symlinks' in ‘os.lchmod()’
     is ‘False’ on Windows.

   - gh-112559(49): *note signal.signal(): 133c. and *note
     signal.getsignal(): 1a0d. no longer call ‘repr’ on callable
     handlers.  *note asyncio.run(): 2f3. and *note
     asyncio.Runner.run(): 1935. no longer call ‘repr’ on the task
     results.  Patch by Yilei Yang.

   - gh-112962(50): *note dis: 3c. module functions add cache
     information to the *note Instruction: 203. instance rather than
     creating fake *note Instruction: 203. instances to represent the
     cache entries.

   - gh-112989(51): Reduce overhead to connect sockets with *note
     asyncio: b. SelectorEventLoop.

   - gh-112970(52): Use ‘closefrom()’ on Linux where available (e.g.
     glibc-2.34), rather than only FreeBSD.

   - gh-110190(53): Fix ctypes structs with array on PPC64LE platform by
     setting ‘MAX_STRUCT_SIZE’ to 64 in stgdict.  Patch by Diego Russo.

   - gh-112540(54): The statistics.geometric_mean() function now returns
     zero for datasets containing a zero.  Formerly, it would raise an
     exception.

   - gh-87286(55): Added ‘LOG_FTP’, ‘LOG_NETINFO’, ‘LOG_REMOTEAUTH’,
     ‘LOG_INSTALL’, ‘LOG_RAS’, and ‘LOG_LAUNCHD’ tot the *note syslog:
     e2. module, all of them constants on used on macOS.

   - gh-112800(56): Fix *note asyncio: b. ‘SubprocessTransport.close()’
     not to throw ‘PermissionError’ when used with setuid executables.

   - gh-51944(57): Add the following constants to the *note termios: e7.
     module.  These values are present in macOS system headers:
     ‘ALTWERASE’, ‘B14400’, ‘B28800’, ‘B7200’, ‘B76800’, ‘CCAR_OFLOW’,
     ‘CCTS_OFLOW’, ‘CDSR_OFLOW’, ‘CDTR_IFLOW’, ‘CIGNORE’, ‘CRTS_IFLOW’,
     ‘EXTPROC’, ‘IUTF8’, ‘MDMBUF’, ‘NL2’, ‘NL3’, ‘NOKERNINFO’, ‘ONOEOT’,
     ‘OXTABS’, ‘VDSUSP’, ‘VSTATUS’.

   - gh-79325(58): Fix an infinite recursion error in *note
     tempfile.TemporaryDirectory(): 143c. cleanup on Windows.

   - gh-94692(59): *note shutil.rmtree(): 356. now only catches OSError
     exceptions.  Previously a symlink attack resistant version of
     ‘shutil.rmtree()’ could ignore or pass to the error handler
     arbitrary exception when invalid arguments were provided.

   - gh-112736(60): The use of del-safe symbols in ‘subprocess’ was
     refactored to allow for use in cross-platform build environments.

   - gh-112727(61): Speed up *note pathlib.Path.absolute(): 1a0e.  Patch
     by Barney Gale.

   - gh-74690(62): Speedup *note issubclass(): 9c6. checks against
     simple *note runtime-checkable protocols: 675. by around 6%.  Patch
     by Alex Waygood.

   - gh-74690(63): Speedup *note isinstance(): 2ad. checks by roughly
     20% for *note runtime-checkable protocols: 675. that only have one
     callable member.  Speedup *note issubclass(): 9c6. checks for these
     protocols by roughly 10%.  Patch by Alex Waygood.

   - gh-112645(64): Remove deprecation error on passing ‘onerror’ to
     *note shutil.rmtree(): 356.

   - gh-112640(65): Add ‘kwdefaults’ parameter to *note
     types.FunctionType: a85. to set default keyword argument values.

   - gh-112622(66): Ensure ‘name’ parameter is passed to event loop in
     *note asyncio.create_task(): 1c9.

   - gh-112618(67): Fix a caching bug relating to *note
     typing.Annotated: b39.  ‘Annotated[str, True]’ is no longer
     identical to ‘Annotated[str, 1]’.

   - gh-112334(68): Fixed a performance regression in 3.12’s *note
     subprocess: dc. on Linux where it would no longer use the fast-path
     ‘vfork()’ system call when it could have due to a logic bug,
     instead falling back to the safe but slower ‘fork()’.

     Also fixed a second 3.12.0 potential security bug.  If a value of
     ‘extra_groups=[]’ was passed to *note subprocess.Popen: 4b8. or
     related APIs, the underlying ‘setgroups(0, NULL)’ system call to
     clear the groups list would not be made in the child process prior
     to ‘exec()’.

     This was identified via code inspection in the process of fixing
     the first bug.

   - gh-110190(69): Fix ctypes structs with array on Arm platform by
     setting ‘MAX_STRUCT_SIZE’ to 32 in stgdict.  Patch by Diego Russo.

   - gh-81194(70): Fix a crash in *note socket.if_indextoname(): c26.
     with specific value (UINT_MAX). Fix an integer overflow in *note
     socket.if_indextoname(): c26. on 64-bit non-Windows platforms.

   - gh-112578(71): Fix a spurious *note RuntimeWarning: 4d8. when
     executing the *note zipfile: 137. module.

   - gh-112516(72): Update the bundled copy of pip to version 23.3.1.

   - gh-112510(73): Add *note readline.backend: 1a0f. for the backend
     readline uses (‘editline’ or ‘readline’)

   - gh-112328(74): [Enum] Make ‘EnumDict’, ‘EnumDict.member_names’,
     ‘EnumType._add_alias_’ and ‘EnumType._add_value_alias_’ public.

   - gh-112509(75): Fix edge cases that could cause a key to be present
     in both the ‘__required_keys__’ and ‘__optional_keys__’ attributes
     of a *note typing.TypedDict: 332.  Patch by Jelle Zijlstra.

   - gh-101336(76): Add ‘keep_alive’ keyword parameter for
     ‘AbstractEventLoop.create_server()’ and
     ‘BaseEventLoop.create_server()’.

   - gh-63284(77): Added support for TLS-PSK (pre-shared key) mode to
     the *note ssl: d5. module.

   - gh-112414(78): Fix regression in Python 3.12 where calling *note
     repr(): 1c1. on a module that had been imported using a custom
     *note loader: 1a10. could fail with *note AttributeError: 5f0.
     Patch by Alex Waygood.

   - gh-112358(79): Revert change to *note struct.Struct: 175f.
     initialization that broke some cases of subclassing.

   - gh-112405(80): Optimize *note pathlib.PurePath.relative_to(): 2fd.
     Patch by Alex Waygood.

   - gh-94722(81): Fix bug where comparison between instances of *note
     DocTest: 1a11. fails if one of them has ‘None’ as its lineno.

   - gh-112361(82): Speed up a small handful of *note pathlib: a8.
     methods by removing some temporary objects.

   - gh-112345(83): Improve error message when trying to call *note
     issubclass(): 9c6. against a *note typing.Protocol: 56b. that has
     non-method members.  Patch by Randolf Scholz.

   - gh-112137(84): Change *note dis: 3c. output to display no-lineno as
     «–» instead of «None».

   - gh-112332(85): Deprecate the ‘exc_type’ field of *note
     traceback.TracebackException: 563.  Add ‘exc_type_str’ to replace
     it.

   - gh-81620(86): Add extra tests for *note random.binomialvariate():
     6d8.

   - gh-112292(87): Fix a crash in *note readline: bf. when imported
     from a sub interpreter.  Patch by Anthony Shaw

   - gh-77621(88): Slightly improve the import time of the *note
     pathlib: a8. module by deferring some imports.  Patch by Barney
     Gale.

   - gh-112137(89): Change *note dis: 3c. output to display logical
     labels for jump targets instead of offsets.

   - gh-112139(90): Add ‘Signature.format()’ to format signatures to
     string with extra options.  And use it in *note pydoc: ba. to
     render more readable signatures that have new lines between
     parameters.

   - gh-112105(91): Make *note readline.set_completer_delims(): 1a12.
     work with libedit

   - gh-106922(92): Display multiple lines with ‘traceback’ when errors
     span multiple lines.

   - gh-111874(93): When creating a *note typing.NamedTuple: 331. class,
     ensure *note __set_name__(): e4a. is called on all objects that
     define ‘__set_name__’ and exist in the values of the ‘NamedTuple’
     class’s class dictionary.  Patch by Alex Waygood.

   - gh-68166(94): Add support of the «vsapi» element type in *note
     tkinter.ttk.Style.element_create(): 55f.

   - gh-110275(95): Named tuple’s methods ‘_replace()’ and
     ‘__replace__()’ now raise TypeError instead of ValueError for
     invalid keyword arguments.

   - gh-99367(96): Do not mangle ‘sys.path[0]’ in *note pdb: aa. if
     safe_path is set

   - gh-111615(97): Fix a regression caused by a fix to gh-93162(98)
     whereby you couldn’t configure a ‘QueueHandler’ without specifying
     handlers.

   - gh-75666(99): Fix the behavior of *note tkinter: f6. widget’s
     ‘unbind()’ method with two arguments.  Previously,
     ‘widget.unbind(sequence, funcid)’ destroyed the current binding for
     'sequence', leaving 'sequence' unbound, and deleted the 'funcid'
     command.  Now it removes only 'funcid' from the binding for
     'sequence', keeping other commands, and deletes the 'funcid'
     command.  It leaves 'sequence' unbound only if 'funcid' was the
     last bound command.

   - gh-67790(100): Implement basic formatting support (minimum width,
     alignment, fill) for *note fractions.Fraction: 213.

   - gh-111049(101): Fix crash during garbage collection of the *note
     io.BytesIO: 10a6. buffer object.

   - gh-102980(102): Redirect the output of ‘interact’ command of *note
     pdb: aa. to the same channel as the debugger.  Add tests and
     improve docs.

   - gh-102988(103): *note email.utils.getaddresses(): 4f4. and *note
     email.utils.parseaddr(): 4f5. now return ‘('', '')’ 2-tuples in
     more situations where invalid email addresses are encountered
     instead of potentially inaccurate values.  Add optional 'strict'
     parameter to these two functions: use ‘strict=False’ to get the old
     behavior, accept malformed inputs.  ‘getattr(email.utils,
     'supports_strict_parsing', False)’ can be use to check if the
     'strict' parameter is available.  Patch by Thomas Dwyer and Victor
     Stinner to improve the CVE 2023-27043(104) fix.

   - gh-52161(105): *note cmd.Cmd.do_help(): 1a13. now cleans docstrings
     with *note inspect.cleandoc(): 1a14. before writing them.  Patch by
     Filip Łapkiewicz.

   - gh-82300(106): Add ‘track’ parameter to *note
     multiprocessing.shared_memory.SharedMemory: 19c0. that allows using
     shared memory blocks without having to register with the POSIX
     resource tracker that automatically releases them upon process
     exit.

   - gh-110109(107): Add private ‘pathlib._PurePathBase’ class: a base
     class for *note pathlib.PurePath: 6ce. that omits certain magic
     methods.  It may be made public (along with ‘_PathBase’) in future.

   - gh-109858(108): Protect *note zipfile: 137. from «quoted-overlap»
     zipbomb.  It now raises BadZipFile when try to read an entry that
     overlaps with other entry or central directory.

   - gh-109786(109): Fix possible reference leaks and crash when
     re-enter the ‘__next__()’ method of *note itertools.pairwise: a18.

   - gh-91539(110): Small (10 - 20%) and trivial performance improvement
     of ‘urllib.request.getproxies_environment()’, typically useful when
     there are many environment variables to go over.

   - gh-103363(111): Add 'follow_symlinks' keyword-only argument to
     *note pathlib.Path.owner(): 53c. and *note group(): 53d, defaulting
     to ‘True’.

   - gh-102130(112): Support tab completion in *note cmd: 1a. for
     ‘editline’.

   - gh-99437(113): *note runpy.run_path(): 4a5. now decodes path-like
     objects, making sure __file__ and sys.argv[0] of the module being
     run are always strings.

   - gh-104003(114): Add *note warnings.deprecated(): 48a, a decorator
     to mark deprecated functions to static type checkers and to warn on
     usage of deprecated classes and functions.  See PEP 702(115).
     Patch by Jelle Zijlstra.

   - gh-103708(116): Make hardcoded python name, a configurable
     parameter so that different implementations of python can override
     it instead of making huge diffs in sysconfig.py

   - gh-66515(117): *note mailbox.MH: 1a15. now supports folders that do
     not contain a ‘.mh_sequences’ file (e.g.  Claws Mail IMAP-cache
     folders).  Patch by Serhiy Storchaka.

   - gh-83162(118): Renamed ‘re.error’ to ‘PatternError’ for clarity,
     and kept ‘re.error’ for backward compatibility.  Patch by Matthias
     Bussonnier and Adam Chhina.

   - gh-91133(119): Fix a bug in *note tempfile.TemporaryDirectory:
     143c. cleanup, which now no longer dereferences symlinks when
     working around file system permission errors.

   - bpo-43153(120): On Windows, ‘tempfile.TemporaryDirectory’
     previously masked a ‘PermissionError’ with ‘NotADirectoryError’
     during directory cleanup.  It now correctly raises
     ‘PermissionError’ if errors are not ignored.  Patch by Andrei
     Kulakov and Ken Jin.

   - bpo-32731(121): *note getpass.getuser(): 65a. now raises *note
     OSError: 2c0. for all failures rather than *note ImportError: 65b.
     on systems lacking the *note pwd: b7. module or *note KeyError:
     5e7. if the password database is empty.

   - bpo-34321(122): *note mmap.mmap: 51a. now has a 'trackfd' parameter
     on Unix; if it is ‘False’, the file descriptor specified by
     'fileno' will not be duplicated.

   - bpo-35332(123): The *note shutil.rmtree(): 356. function now
     ignores errors when calling *note os.close(): d6d. when
     'ignore_errors' is ‘True’, and *note os.close(): d6d. no longer
     retried after error.

   - bpo-35928(124): *note io.TextIOWrapper: 9c0. now correctly handles
     the decoding buffer after ‘read()’ and ‘write()’.

   - bpo-26791(125): *note shutil.move(): c53. now moves a symlink into
     a directory when that directory is the target of the symlink.  This
     provides the same behavior as the mv shell command.  The previous
     behavior raised an exception.  Patch by Jeffrey Kintscher.

   - bpo-41422(126): Fixed memory leaks of *note pickle.Pickler: c15.
     and *note pickle.Unpickler: 175e. involving cyclic references via
     the internal memo mapping.

   - bpo-19821(127): The ‘pydoc.ispackage()’ function has been
     deprecated.

   - bpo-40262(128): The ‘ssl.SSLSocket.recv_into()’ method no longer
     requires the 'buffer' argument to implement ‘__len__’ and supports
     buffers with arbitrary item size.

   - bpo-39912(129): *note warnings.filterwarnings(): 16b0. and *note
     warnings.simplefilter(): 8d1. now raise appropriate exceptions
     instead of ‘AssertionError’.  Patch contributed by Rémi Lapeyre.

   - bpo-37260(130): Fixed a race condition in *note shutil.rmtree():
     356. in which directory entries removed by another process or
     thread while ‘shutil.rmtree()’ is running can cause it to raise
     FileNotFoundError.  Patch by Jeffrey Kintscher.

   - bpo-36959(131): Fix some error messages for invalid ISO format
     string combinations in ‘strptime()’ that referred to directives not
     contained in the format string.  Patch by Gordon P. Hemsley.

   - bpo-18060(132): Fixed a class inheritance issue that can cause
     segfaults when deriving two or more levels of subclasses from a
     base class of Structure or Union.

   - bpo-29779(133): Add a new *note PYTHON_HISTORY: 4b1. environment
     variable to set the location of a ‘.python_history’ file.

   - bpo-21360(134): *note mailbox.Maildir: 65e. now ignores files with
     a leading dot.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/114077

   (2) https://github.com/python/cpython/issues/111803

   (3) https://github.com/python/cpython/issues/114014

   (4) https://github.com/python/cpython/issues/108364

   (5) https://github.com/python/cpython/issues/113971

   (6) https://github.com/python/cpython/issues/113877

   (7) https://github.com/python/cpython/issues/113868

   (8) https://github.com/python/cpython/issues/113848

   (9) https://github.com/python/cpython/issues/113661

   (10) https://github.com/python/cpython/issues/96037

   (11) https://github.com/python/cpython/issues/113781

   (12) https://github.com/python/cpython/issues/113238

   (13) https://github.com/python/cpython/issues/111693

   (14) https://github.com/python/cpython/issues/113791

   (15) https://github.com/python/cpython/issues/112932

   (16) https://github.com/python/cpython/issues/113568

   (17) https://github.com/python/cpython/issues/113594

   (18) https://github.com/python/cpython/issues/113538

   (19) https://github.com/python/cpython/issues/113626

   (20) https://github.com/python/cpython/issues/85567

   (21) https://github.com/python/cpython/issues/113537

   (22) https://github.com/python/cpython/issues/89850

   (23) https://github.com/python/cpython/issues/113569

   (24) https://github.com/python/cpython/issues/101225

   (25) https://github.com/python/cpython/issues/113568

   (26) https://github.com/python/cpython/issues/113543

   (27) https://github.com/python/cpython/issues/113028

   (28) https://github.com/python/cpython/issues/113421

   (29) https://github.com/python/cpython/issues/111784

   (30) https://github.com/python/cpython/issues/113407

   (31) https://github.com/python/cpython/issues/113320

   (32) https://github.com/python/cpython/issues/53502

   (33) https://github.com/python/cpython/issues/113358

   (34) https://github.com/python/cpython/issues/113214

   (35) https://github.com/python/cpython/issues/113246

   (36) https://github.com/python/cpython/issues/87264

   (37) https://github.com/python/cpython/issues/112182

   (38) https://github.com/python/cpython/issues/113225

   (39) https://github.com/python/cpython/issues/113149

   (40) https://github.com/python/cpython/issues/113117

   (41) https://github.com/python/cpython/issues/113199

   (42) https://github.com/python/cpython/issues/113191

   (43) https://github.com/python/cpython/issues/113188

   (44) https://github.com/python/cpython/issues/113119

   (45) https://github.com/python/cpython/issues/113202

   (46) https://github.com/python/cpython/issues/61648

   (47) https://github.com/python/cpython/issues/113175

   (48) https://github.com/python/cpython/issues/59616

   (49) https://github.com/python/cpython/issues/112559

   (50) https://github.com/python/cpython/issues/112962

   (51) https://github.com/python/cpython/issues/112989

   (52) https://github.com/python/cpython/issues/112970

   (53) https://github.com/python/cpython/issues/110190

   (54) https://github.com/python/cpython/issues/112540

   (55) https://github.com/python/cpython/issues/87286

   (56) https://github.com/python/cpython/issues/112800

   (57) https://github.com/python/cpython/issues/51944

   (58) https://github.com/python/cpython/issues/79325

   (59) https://github.com/python/cpython/issues/94692

   (60) https://github.com/python/cpython/issues/112736

   (61) https://github.com/python/cpython/issues/112727

   (62) https://github.com/python/cpython/issues/74690

   (63) https://github.com/python/cpython/issues/74690

   (64) https://github.com/python/cpython/issues/112645

   (65) https://github.com/python/cpython/issues/112640

   (66) https://github.com/python/cpython/issues/112622

   (67) https://github.com/python/cpython/issues/112618

   (68) https://github.com/python/cpython/issues/112334

   (69) https://github.com/python/cpython/issues/110190

   (70) https://github.com/python/cpython/issues/81194

   (71) https://github.com/python/cpython/issues/112578

   (72) https://github.com/python/cpython/issues/112516

   (73) https://github.com/python/cpython/issues/112510

   (74) https://github.com/python/cpython/issues/112328

   (75) https://github.com/python/cpython/issues/112509

   (76) https://github.com/python/cpython/issues/101336

   (77) https://github.com/python/cpython/issues/63284

   (78) https://github.com/python/cpython/issues/112414

   (79) https://github.com/python/cpython/issues/112358

   (80) https://github.com/python/cpython/issues/112405

   (81) https://github.com/python/cpython/issues/94722

   (82) https://github.com/python/cpython/issues/112361

   (83) https://github.com/python/cpython/issues/112345

   (84) https://github.com/python/cpython/issues/112137

   (85) https://github.com/python/cpython/issues/112332

   (86) https://github.com/python/cpython/issues/81620

   (87) https://github.com/python/cpython/issues/112292

   (88) https://github.com/python/cpython/issues/77621

   (89) https://github.com/python/cpython/issues/112137

   (90) https://github.com/python/cpython/issues/112139

   (91) https://github.com/python/cpython/issues/112105

   (92) https://github.com/python/cpython/issues/106922

   (93) https://github.com/python/cpython/issues/111874

   (94) https://github.com/python/cpython/issues/68166

   (95) https://github.com/python/cpython/issues/110275

   (96) https://github.com/python/cpython/issues/99367

   (97) https://github.com/python/cpython/issues/111615

   (98) https://github.com/python/cpython/issues/93162

   (99) https://github.com/python/cpython/issues/75666

   (100) https://github.com/python/cpython/issues/67790

   (101) https://github.com/python/cpython/issues/111049

   (102) https://github.com/python/cpython/issues/102980

   (103) https://github.com/python/cpython/issues/102988

   (104) https://www.cve.org/CVERecord?id=CVE-2023-27043

   (105) https://github.com/python/cpython/issues/52161

   (106) https://github.com/python/cpython/issues/82300

   (107) https://github.com/python/cpython/issues/110109

   (108) https://github.com/python/cpython/issues/109858

   (109) https://github.com/python/cpython/issues/109786

   (110) https://github.com/python/cpython/issues/91539

   (111) https://github.com/python/cpython/issues/103363

   (112) https://github.com/python/cpython/issues/102130

   (113) https://github.com/python/cpython/issues/99437

   (114) https://github.com/python/cpython/issues/104003

   (115) https://peps.python.org/pep-0702/

   (116) https://github.com/python/cpython/issues/103708

   (117) https://github.com/python/cpython/issues/66515

   (118) https://github.com/python/cpython/issues/83162

   (119) https://github.com/python/cpython/issues/91133

   (120) https://bugs.python.org/issue?@action=redirect&bpo=43153

   (121) https://bugs.python.org/issue?@action=redirect&bpo=32731

   (122) https://bugs.python.org/issue?@action=redirect&bpo=34321

   (123) https://bugs.python.org/issue?@action=redirect&bpo=35332

   (124) https://bugs.python.org/issue?@action=redirect&bpo=35928

   (125) https://bugs.python.org/issue?@action=redirect&bpo=26791

   (126) https://bugs.python.org/issue?@action=redirect&bpo=41422

   (127) https://bugs.python.org/issue?@action=redirect&bpo=19821

   (128) https://bugs.python.org/issue?@action=redirect&bpo=40262

   (129) https://bugs.python.org/issue?@action=redirect&bpo=39912

   (130) https://bugs.python.org/issue?@action=redirect&bpo=37260

   (131) https://bugs.python.org/issue?@action=redirect&bpo=36959

   (132) https://bugs.python.org/issue?@action=redirect&bpo=18060

   (133) https://bugs.python.org/issue?@action=redirect&bpo=29779

   (134) https://bugs.python.org/issue?@action=redirect&bpo=21360


File: python.info,  Node: Documentation<18>,  Next: Tests<17>,  Prev: Library<61>,  Up: Python 3 13 0 alpha 3

1.24.23.4 Documentation
.......................

   - gh-111699(1): Relocate ‘smtpd’ deprecation notice to its own
     section rather than under ‘locale’ in What’s New in Python 3.12
     document

   - gh-110746(2): Improved markup for valid options/values for methods
     ttk.treeview.column and ttk.treeview.heading, and for Layouts.

   - gh-95649(3): Document that the *note asyncio: b. module contains
     code taken from v0.16.0 of the uvloop project(4), as well as the
     required MIT licensing information.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/111699

   (2) https://github.com/python/cpython/issues/110746

   (3) https://github.com/python/cpython/issues/95649

   (4) https://github.com/MagicStack/uvloop/tree/v0.16.0


File: python.info,  Node: Tests<17>,  Next: Build<20>,  Prev: Documentation<18>,  Up: Python 3 13 0 alpha 3

1.24.23.5 Tests
...............

   - gh-111798(1): Disable ‘test_super_deep()’ from ‘test_call’ under
     pydebug builds on WASI; the stack depth is too small to make the
     test useful.

   - gh-111801(2): Lower the recursion limit in ‘test_isinstance’ for
     ‘test_infinitely_many_bases()’.  This prevents a stack overflow on
     a pydebug build of WASI.

   - gh-111802(3): Specify a low recursion depth for
     ‘test_bad_getattr()’ in ‘test.pickletester’ to avoid exhausting the
     stack under a pydebug build for WASI.

   - gh-44626(4): Fix *note os.path.isabs(): 532. incorrectly returning
     ‘True’ when given a path that starts with exactly one (back)slash
     on Windows.

     Fix ‘pathlib.PureWindowsPath.is_absolute()’ incorrectly returning
     ‘False’ for some paths beginning with two (back)slashes.

   - gh-113633(5): Use module state for the _testcapi extension module.

   - gh-109980(6): Fix ‘test_tarfile_vs_tar’ in ‘test_shutil’ for macOS,
     where system tar can include more information in the archive than
     *note shutil.make_archive: 6db.

   - gh-112769(7): The tests now correctly compare zlib version when
     *note zlib.ZLIB_RUNTIME_VERSION: 1376. contains non-integer
     suffixes.  For example zlib-ng defines the version as
     ‘1.3.0.zlib-ng’.

   - gh-112334(8): Adds a regression test to verify that ‘vfork()’ is
     used when expected by *note subprocess: dc. on vfork enabled POSIX
     systems (Linux).

   - gh-108927(9): Fixed order dependence in running tests in the same
     process when a test that has submodules (e.g.  test_importlib)
     follows a test that imports its submodule (e.g.
     test_importlib.util) and precedes a test (e.g.  test_unittest or
     test_compileall) that uses that submodule.

   - bpo-40648(10): Test modes that file can get with chmod() on
     Windows.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/111798

   (2) https://github.com/python/cpython/issues/111801

   (3) https://github.com/python/cpython/issues/111802

   (4) https://github.com/python/cpython/issues/44626

   (5) https://github.com/python/cpython/issues/113633

   (6) https://github.com/python/cpython/issues/109980

   (7) https://github.com/python/cpython/issues/112769

   (8) https://github.com/python/cpython/issues/112334

   (9) https://github.com/python/cpython/issues/108927

   (10) https://bugs.python.org/issue?@action=redirect&bpo=40648


File: python.info,  Node: Build<20>,  Next: Windows<18>,  Prev: Tests<17>,  Up: Python 3 13 0 alpha 3

1.24.23.6 Build
...............

   - gh-114013(1): Fix ‘Tools/wasm/wasi.py’ to not include the path to
     ‘python.wasm’ as part of ‘HOSTRUNNER’.  The environment variable is
     meant to specify how to run the WASI host only, having
     ‘python.wasm’ and relevant flags appended to the ‘HOSTRUNNER’.
     This fixes ‘make test’ work.

   - gh-113258(2): Changed the Windows build to write out generated
     frozen modules into the build tree instead of the source tree.

   - gh-112305(3): Fixed the ‘check-clean-src’ step performed on out of
     tree builds to detect errant ‘$(srcdir)/Python/frozen_modules/*.h’
     files and recommend appropriate source tree cleanup steps to get a
     working build again.

   - gh-112536(4): Add support for thread sanitizer (TSAN)

   - gh-112867(5): Fix the build for the case that
     WITH_PYMALLOC_RADIX_TREE=0 set.

   - gh-103065(6): Introduce ‘Tools/wasm/wasi.py’ to simplify doing a
     WASI build.

   - bpo-11102(7): The *note os.major(): 1946, *note os.makedev(): 1948,
     and *note os.minor(): 1947. functions are now available on HP-UX
     v3.

   - bpo-36351(8): Do not set ipv6type when cross-compiling.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/114013

   (2) https://github.com/python/cpython/issues/113258

   (3) https://github.com/python/cpython/issues/112305

   (4) https://github.com/python/cpython/issues/112536

   (5) https://github.com/python/cpython/issues/112867

   (6) https://github.com/python/cpython/issues/103065

   (7) https://bugs.python.org/issue?@action=redirect&bpo=11102

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36351


File: python.info,  Node: Windows<18>,  Next: macOS<11>,  Prev: Build<20>,  Up: Python 3 13 0 alpha 3

1.24.23.7 Windows
.................

   - gh-114096(1): Process privileges that are activated for creating
     directory junctions are now restored afterwards, avoiding behaviour
     changes in other parts of the program.

   - gh-111877(2): *note os.stat(): 26d. calls were returning incorrect
     time values for files that could not be accessed directly.

   - gh-111973(3): Update Windows installer to use SQLite 3.44.2.

   - gh-113009(4): *note multiprocessing: 98.: On Windows, fix a race
     condition in ‘Process.terminate()’: no longer set the ‘returncode’
     attribute to always call ‘WaitForSingleObject()’ in
     ‘Process.wait()’.  Previously, sometimes the process was still
     running after ‘TerminateProcess()’ even if ‘GetExitCodeProcess()’
     is not ‘STILL_ACTIVE’.  Patch by Victor Stinner.

   - gh-86179(5): Fixes path calculations when launching Python on
     Windows through a symlink.

   - gh-71383(6): Update Tcl/Tk in Windows installer to 8.6.13 with a
     patch to suppress incorrect ThemeChanged warnings.

   - gh-111650(7): Ensures the ‘Py_GIL_DISABLED’ preprocessor variable
     is defined in ‘pyconfig.h’ so that extension modules written in C
     are able to use it.

   - gh-112278(8): Reduce the time cost for some functions in *note
     platform: af. on Windows if current user has no permission to the
     WMI.

   - gh-73427(9): Deprecate *note sys._enablelegacywindowsfsencoding():
     33e.  Use *note PYTHONLEGACYWINDOWSFSENCODING: 33f. instead.  Patch
     by Inada Naoki.

   - gh-87868(10): Correctly sort and remove duplicate environment
     variables in ‘_winapi.CreateProcess()’.

   - bpo-37308(11): Fix mojibake in *note mmap.mmap: 51a. when using a
     non-ASCII 'tagname' argument on Windows.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/114096

   (2) https://github.com/python/cpython/issues/111877

   (3) https://github.com/python/cpython/issues/111973

   (4) https://github.com/python/cpython/issues/113009

   (5) https://github.com/python/cpython/issues/86179

   (6) https://github.com/python/cpython/issues/71383

   (7) https://github.com/python/cpython/issues/111650

   (8) https://github.com/python/cpython/issues/112278

   (9) https://github.com/python/cpython/issues/73427

   (10) https://github.com/python/cpython/issues/87868

   (11) https://bugs.python.org/issue?@action=redirect&bpo=37308


File: python.info,  Node: macOS<11>,  Next: IDLE<11>,  Prev: Windows<18>,  Up: Python 3 13 0 alpha 3

1.24.23.8 macOS
...............

   - gh-113666(1): Add the following constants to module *note stat:
     d6.: ‘UF_SETTABLE’, ‘UF_TRACKED’, ‘UF_DATAVAULT’, ‘SF_SUPPORTED’,
     ‘SF_SETTABLE’, ‘SF_SYNTHETIC’, ‘SF_RESTRICTED’, ‘SF_FIRMLINK’ and
     ‘SF_DATALESS’.  The values ‘UF_SETTABLE’, ‘SF_SUPPORTED’,
     ‘SF_SETTABLE’ and ‘SF_SYNTHETIC’ are only available on macOS.

   - gh-113536(2): *note os.waitid(): f9b. is now available on macOS

   - gh-110459(3): Running ‘configure ... --with-openssl-rpath=X/Y/Z’ no
     longer fails to detect OpenSSL on macOS.

   - gh-74573(4): Document that *note dbm.ndbm: 38. can silently corrupt
     DBM files on updates when exceeding undocumented platform limits,
     and can crash (segmentation fault) when reading such a corrupted
     file.  (FB8919203)

   - gh-65701(5): The ‘freeze’ tool doesn’t work with framework builds
     of Python.  Document this and bail out early when running the tool
     with such a build.

   - gh-87277(6): webbrowser: Don’t look for X11 browsers on macOS.
     Those are generally not used and probing for them can result in
     starting XQuartz even if it isn’t used otherwise.

   - gh-111973(7): Update macOS installer to use SQLite 3.44.2.

   - gh-108269(8): Set ‘CFBundleAllowMixedLocalizations’ to true in the
     Info.plist for the framework, embedded Python.app and IDLE.app with
     framework installs on macOS. This allows applications to pick up
     the user’s preferred locale when that’s different from english.

   - gh-102362(9): Make sure the result of ‘sysconfig.get_plaform()’
     includes at least a major and minor versions, even if
     ‘MACOSX_DEPLOYMENT_TARGET’ is set to only a major version during
     build to match the format expected by pip.

   - gh-110017(10): Disable a signal handling stress test on macOS due
     to a bug in macOS (FB13453490).

   - gh-110820(11): Make sure the preprocessor definitions for
     ‘ALIGNOF_MAX_ALIGN_T’, ‘SIZEOF_LONG_DOUBLE’ and
     ‘HAVE_GCC_ASM_FOR_X64’ are correct for Universal 2 builds on macOS.

   - gh-109981(12): Use ‘/dev/fd’ on macOS to determine the number of
     open files in ‘test.support.os_helper.fd_count’ to avoid a crash
     with «guarded» file descriptors when probing for open files.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/113666

   (2) https://github.com/python/cpython/issues/113536

   (3) https://github.com/python/cpython/issues/110459

   (4) https://github.com/python/cpython/issues/74573

   (5) https://github.com/python/cpython/issues/65701

   (6) https://github.com/python/cpython/issues/87277

   (7) https://github.com/python/cpython/issues/111973

   (8) https://github.com/python/cpython/issues/108269

   (9) https://github.com/python/cpython/issues/102362

   (10) https://github.com/python/cpython/issues/110017

   (11) https://github.com/python/cpython/issues/110820

   (12) https://github.com/python/cpython/issues/109981


File: python.info,  Node: IDLE<11>,  Next: C API<20>,  Prev: macOS<11>,  Up: Python 3 13 0 alpha 3

1.24.23.9 IDLE
..............

   - gh-72284(1): Improve the lists of features, editor key bindings,
     and shell key bingings in the IDLE doc.

   - gh-113903(2): Fix rare failure of test.test_idle, in
     test_configdialog.

   - gh-113729(3): Fix the «Help -> IDLE Doc» menu bug in 3.11.7 and
     3.12.1.

   - gh-113269(4): Fix test_editor hang on macOS Catalina.

   - gh-112898(5): Fix processing unsaved files when quitting IDLE on
     macOS.

   - bpo-13586(6): Enter the selected text when opening the «Replace»
     dialog.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/72284

   (2) https://github.com/python/cpython/issues/113903

   (3) https://github.com/python/cpython/issues/113729

   (4) https://github.com/python/cpython/issues/113269

   (5) https://github.com/python/cpython/issues/112898

   (6) https://bugs.python.org/issue?@action=redirect&bpo=13586


File: python.info,  Node: C API<20>,  Prev: IDLE<11>,  Up: Python 3 13 0 alpha 3

1.24.23.10 C API
................

   - gh-106560(1): Fix redundant declarations in the public C API.
     Declare PyBool_Type, PyLong_Type and PySys_Audit() only once.
     Patch by Victor Stinner.

   - gh-112438(2): Fix support of format units «es», «et», «es#», and
     «et#» in nested tuples in *note PyArg_ParseTuple(): 3c1.-like
     functions.

   - gh-111545(3): Add *note Py_HashPointer(): 425. function to hash a
     pointer.  Patch by Victor Stinner.

   - gh-65210(4): Change the declaration of the 'keywords' parameter of
     *note PyArg_ParseTupleAndKeywords(): 624. and *note
     PyArg_VaParseTupleAndKeywords(): 625. for better compatibility with
     C++.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/106560

   (2) https://github.com/python/cpython/issues/112438

   (3) https://github.com/python/cpython/issues/111545

   (4) https://github.com/python/cpython/issues/65210


File: python.info,  Node: Python 3 13 0 alpha 2,  Next: Python 3 13 0 alpha 1,  Prev: Python 3 13 0 alpha 3,  Up: Changelog

1.24.24 Python 3.13.0 alpha 2
-----------------------------

'Release date: 2023-11-22'

* Menu:

* Core and Builtins: Core and Builtins<57>.
* Library: Library<62>.
* Tests: Tests<18>.
* Build: Build<21>.
* Windows: Windows<19>.
* macOS: macOS<12>.
* IDLE: IDLE<12>.
* Tools/Demos: Tools/Demos<18>.
* C API: C API<21>.


File: python.info,  Node: Core and Builtins<57>,  Next: Library<62>,  Up: Python 3 13 0 alpha 2

1.24.24.1 Core and Builtins
...........................

   - gh-112243(1): Don’t include comments in f-string debug expressions.
     Patch by Pablo Galindo

   - gh-112287(2): Slightly optimize the Tier 2 (uop) interpreter by
     only loading ‘oparg’ and ‘operand’ when needed.  Also double the
     trace size limit again, to 512 this time.

   - gh-112266(3): Change docstrings of *note __dict__: 77e. and
     ‘__weakref__’.

   - gh-111807(4): Lower the max parser stack depth to 1000 under WASI
     debug builds.

   - gh-111798(5): When Python is built in debug mode, set the C
     recursion limit to 500 instead of 1500.  A debug build is likely
     built with low optimization level which implies higher stack memory
     usage than a release build.  Patch by Victor Stinner.

   - gh-106529(6): Enable translating unspecialized ‘FOR_ITER’ to Tier
     2.

   - gh-111916(7): Make hashlib related modules thread-safe without the
     GIL

   - gh-81137(8): Deprecate assignment to a function’s ‘__code__’ field
     when the new code object is of a mismatched type (e.g., from a
     generator to a plain function).

   - gh-79932(9): Raise exception if *note frame.clear(): 585. is called
     on a suspended frame.

   - gh-81925(10): Implement native thread ids for GNU KFreeBSD.

   - gh-111843(11): Use exponential backoff to reduce the number of
     failed tier 2 optimization attempts by over 99%.

   - gh-110829(12): Joining a thread now ensures the underlying OS
     thread has exited.  This is required for safer fork() in
     multi-threaded processes.

   - gh-109369(13): Make sure that tier 2 traces are de-optimized if the
     code is instrumented

   - gh-111772(14): Specialize slot loads and stores for _Py_T_OBJECT as
     well as Py_T_OBJECT_EX

   - gh-111666(15): Speed up *note BaseExceptionGroup.derive(): 1a1f,
     *note BaseExceptionGroup.subgroup(): 1a20, and *note
     BaseExceptionGroup.split(): 18c0. by changing how they parse passed
     arguments.

   - gh-111654(16): Fix runtime crash when some error happens in opcode
     ‘LOAD_FROM_DICT_OR_DEREF’.

   - gh-111623(17): Add support for sharing tuples between interpreters
     using the cross-interpreter API. Patch by Anthony Shaw.

   - gh-111354(18): The oparg of *note YIELD_VALUE: 5ba. is now ‘1’ if
     the instruction is part of a yield-from or await, and ‘0’
     otherwise.

     The SUSPENDED frame state is now split into ‘SUSPENDED’ and
     ‘SUSPENDED_YIELD_FROM’.  This simplifies the code in ‘_PyGen_yf’.

   - gh-111520(19): Merge the Tier 1 (bytecode) and Tier 2 (micro-ops)
     interpreters together, moving the Tier 2 interpreter loop and
     switch into ‘_PyEval_EvalFrameDefault()’ in ‘Python/ceval.c’.  The
     ‘Python/executor.c’ file is gone.  Also the ‘TIER_ONE’ and
     ‘TIER_TWO’ macros are now handled by the code generator.

     'Beware!'  This changes the environment variables to enable
     micro-ops and their debugging to ‘PYTHON_UOPS’ and
     ‘PYTHON_LLTRACE’.

   - gh-109181(20): Speed up ‘Traceback’ object creation by lazily
     compute the line number.  Patch by Pablo Galindo

   - gh-111420(21): Allow type comments in parenthesized ‘with’
     statements

   - gh-111438(22): Add support for sharing floats between interpreters
     using the cross-interpreter API. Patch by Anthony Shaw.

   - gh-111435(23): Add support for sharing of ‘True’ and ‘False’
     between interpreters using the cross-interpreter API. Patch by
     Anthony Shaw.

   - gh-102388(24): Fix a bug where ‘iso2022_jp_3’ and ‘iso2022_jp_2004’
     codecs read out of bounds

   - gh-111366(25): Fix an issue in the *note codeop: 1d. that was
     causing *note SyntaxError: 18e. exceptions raised in the presence
     of invalid syntax to not contain precise error messages.  Patch by
     Pablo Galindo

   - gh-111380(26): Fix a bug that was causing *note SyntaxWarning: 1ae.
     to appear twice when parsing if invalid syntax is encountered
     later.  Patch by Pablo galindo

   - gh-111374(27): Added a new environment variable *note
     PYTHON_FROZEN_MODULES: 4ae.  It determines whether or not frozen
     modules are ignored by the import machinery, equivalent of the
     *note -X frozen_modules: 16f. command-line option.

   - gh-111354(28): Remove ‘oparg’ from *note YIELD_VALUE: 5ba.  Change
     ‘oparg’ of *note RESUME: 5bb. to include information about the
     except-depth.  These changes make it possible to simplify the code
     in generator close.

   - gh-94438(29): Fix a regression that prevented jumping across ‘is
     None’ and ‘is not None’ when debugging.  Patch by Savannah
     Ostrowski.

   - gh-67224(30): Show source lines in tracebacks when using the ‘-c’
     option when running Python.  Patch by Pablo Galindo

   - gh-111123(31): Fix a bug where a *note global: 4ad. declaration in
     an *note except: 1ab. block is rejected when the global is used in
     the *note else: 17c. block.

   - gh-110938(32): Fix error messages for indented blocks with
     functions and classes with generic type parameters.  Patch by Pablo
     Galindo

   - gh-109214(33): Remove unnecessary instruction pointer updates
     before returning from frames.

   - gh-110912(34): Correctly display the traceback for *note
     MemoryError: 1786. exceptions using the *note traceback: 104.
     module.  Patch by Pablo Galindo

   - gh-109894(35): Fixed crash due to improperly initialized static
     *note MemoryError: 1786. in subinterpreter.

   - gh-110892(36): Return ‘NULL’ for ‘PyTrace_RETURN’ events caused by
     an exception

   - gh-110864(37): Fix argument parsing by
     ‘_PyArg_UnpackKeywordsWithVararg’ for functions defining
     pos-or-keyword, vararg, and kw-only parameters.

   - gh-109094(38): Replace ‘prev_instr’ on the interpreter frame by
     ‘instr_ptr’ which points to the beginning of the instruction that
     is currently executing (or will execute once the frame resumes).

   - gh-110805(39): Allow the repl to show source code and complete
     tracebacks.  Patch by Pablo Galindo

   - gh-110722(40): Add ‘PYTHON_PRESITE=package.module’ to import a
     module early in the interpreter lifecycle before ‘site.py’ is
     executed.  Python needs to be *note built in debug mode: 50a. for
     this option to exist.

   - gh-110481(41): Implement biased reference counting in
     ‘--disable-gil’ builds.

   - gh-110543(42): Fix regression in Python 3.12 where
     ‘types.CodeType.replace()’ would produce a broken code object if
     called on a module or class code object that contains a
     comprehension.  Patch by Jelle Zijlstra.

   - gh-89519(43): Removed chained *note classmethod: 48f. descriptors
     (introduced in bpo-19072(44)).  This can no longer be used to wrap
     other descriptors such as *note property: 4b4.  The core design of
     this feature was flawed and caused a number of downstream problems.
     To «pass-through» a *note classmethod: 48f, consider using the
     ‘__wrapped__’ attribute that was added in Python 3.10.

   - gh-103615(45): Use local events for opcode tracing

   - bpo-46657(46): Add mimalloc memory allocator support.

   - gh-106718(47): When PyConfig.stdlib_dir is explicitly set, it’s now
     respected and won’t be overridden by PyConfig.home.

   - gh-106905(48): Fix incorrect SystemError about AST constructor
     recursion depth mismatch.

   - gh-100445(49): Improve error message for unterminated strings with
     escapes.

   - bpo-45759(50): Improved error messages for ‘elif’/‘else’ statements
     not matching any valid statements.  Patch by Jeremiah Vivian.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/112243

   (2) https://github.com/python/cpython/issues/112287

   (3) https://github.com/python/cpython/issues/112266

   (4) https://github.com/python/cpython/issues/111807

   (5) https://github.com/python/cpython/issues/111798

   (6) https://github.com/python/cpython/issues/106529

   (7) https://github.com/python/cpython/issues/111916

   (8) https://github.com/python/cpython/issues/81137

   (9) https://github.com/python/cpython/issues/79932

   (10) https://github.com/python/cpython/issues/81925

   (11) https://github.com/python/cpython/issues/111843

   (12) https://github.com/python/cpython/issues/110829

   (13) https://github.com/python/cpython/issues/109369

   (14) https://github.com/python/cpython/issues/111772

   (15) https://github.com/python/cpython/issues/111666

   (16) https://github.com/python/cpython/issues/111654

   (17) https://github.com/python/cpython/issues/111623

   (18) https://github.com/python/cpython/issues/111354

   (19) https://github.com/python/cpython/issues/111520

   (20) https://github.com/python/cpython/issues/109181

   (21) https://github.com/python/cpython/issues/111420

   (22) https://github.com/python/cpython/issues/111438

   (23) https://github.com/python/cpython/issues/111435

   (24) https://github.com/python/cpython/issues/102388

   (25) https://github.com/python/cpython/issues/111366

   (26) https://github.com/python/cpython/issues/111380

   (27) https://github.com/python/cpython/issues/111374

   (28) https://github.com/python/cpython/issues/111354

   (29) https://github.com/python/cpython/issues/94438

   (30) https://github.com/python/cpython/issues/67224

   (31) https://github.com/python/cpython/issues/111123

   (32) https://github.com/python/cpython/issues/110938

   (33) https://github.com/python/cpython/issues/109214

   (34) https://github.com/python/cpython/issues/110912

   (35) https://github.com/python/cpython/issues/109894

   (36) https://github.com/python/cpython/issues/110892

   (37) https://github.com/python/cpython/issues/110864

   (38) https://github.com/python/cpython/issues/109094

   (39) https://github.com/python/cpython/issues/110805

   (40) https://github.com/python/cpython/issues/110722

   (41) https://github.com/python/cpython/issues/110481

   (42) https://github.com/python/cpython/issues/110543

   (43) https://github.com/python/cpython/issues/89519

   (44) https://bugs.python.org/issue?@action=redirect&bpo=19072

   (45) https://github.com/python/cpython/issues/103615

   (46) https://bugs.python.org/issue?@action=redirect&bpo=46657

   (47) https://github.com/python/cpython/issues/106718

   (48) https://github.com/python/cpython/issues/106905

   (49) https://github.com/python/cpython/issues/100445

   (50) https://bugs.python.org/issue?@action=redirect&bpo=45759


File: python.info,  Node: Library<62>,  Next: Tests<18>,  Prev: Core and Builtins<57>,  Up: Python 3 13 0 alpha 2

1.24.24.2 Library
.................

   - gh-111942(1): Fix SystemError in the TextIOWrapper constructor with
     non-encodable «errors» argument in non-debug mode.

   - gh-111995(2): Added the ‘NI_IDN’ constant to the *note socket: d1.
     module when present in C at build time for use with *note
     socket.getnameinfo(): 1a22.

   - gh-109538(3): Issue warning message instead of having *note
     RuntimeError: 244. be displayed when event loop has already been
     closed at ‘StreamWriter.__del__()’.

   - gh-111942(4): Fix crashes in *note io.TextIOWrapper.reconfigure():
     d42. when pass invalid arguments, e.g.  non-string encoding.

   - gh-111460(5): *note curses: 2f.: restore wide character support
     (including *note curses.unget_wch(): 12a0. and *note get_wch():
     129f.) on macOS, which was unavailable due to a regression in
     Python 3.12.

   - gh-103791(6): *note contextlib.suppress: 112a. now supports
     suppressing exceptions raised as part of a *note
     BaseExceptionGroup: 566, in addition to the recent support for
     *note ExceptionGroup: 4d3.

   - gh-111835(7): The *note mmap.mmap: 51a. class now has an *note
     seekable(): 51b. method that can be used when a seekable file-like
     object is required.  The *note seek(): 51c. method now returns the
     new absolute position.  Patch by Donghee Na.

   - gh-111804(8): Remove posix.fallocate() under WASI as the underlying
     posix_fallocate() is not available in WASI preview2.

   - gh-111841(9): Fix truncating arguments on an embedded null
     character in *note os.putenv(): 25b. and *note os.unsetenv(): 25c.
     on Windows.

   - gh-111768(10): *note wsgiref.util.is_hop_by_hop(): 1a23. is now
     exposed correctly in ‘__all__’.

   - gh-80731(11): Avoid executing the default function in *note
     cmd.Cmd: 1836. in an except block

   - gh-111541(12): Fix *note doctest: 3e. for *note SyntaxError: 18e.
     not-builtin subclasses.

   - gh-111719(13): Add extra argument validation for ‘alias’ command in
     *note pdb: aa.

   - gh-111482(14): *note time: f4.: Make *note time.clock_gettime():
     1366. and *note time.clock_gettime_ns(): cdd. functions up to 2x
     faster by faster calling convention.  Patch by Victor Stinner.

   - gh-110894(15): Call loop exception handler for exceptions in
     ‘client_connected_cb’ of *note asyncio.start_server(): d11. so that
     applications can handle it.  Patch by Kumar Aditya.

   - gh-111531(16): Fix reference leaks in ‘bind_class()’ and
     ‘bind_all()’ methods of *note tkinter: f6. widgets.

   - gh-111246(17): *note asyncio.loop.create_unix_server(): 4cb. will
     now automatically remove the Unix socket when the server is closed.

   - gh-111356(18): Added *note io.text_encoding(): 1a24, *note
     io.DEFAULT_BUFFER_SIZE: 1a25, and *note
     io.IncrementalNewlineDecoder: 1a26. to ‘io.__all__’.

   - gh-66425(19): Remove the code to set the REMOTE_HOST header from
     wsgiref module, as it is unreachable.  This header is used for
     performance reasons, which is not necessary in the wsgiref module.

   - gh-111429(20): Speed up *note pathlib.PurePath.relative_to(): 2fd.
     and *note is_relative_to(): 2fe.

   - gh-111342(21): Fixed typo in *note math.sumprod(): 6c0.

   - gh-68166(22): Remove mention of not supported «vsapi» element type
     in *note tkinter.ttk.Style.element_create(): 55f.  Add tests for
     ‘element_create()’ and other ‘ttk.Style’ methods.  Add examples for
     ‘element_create()’ in the documentation.

   - gh-111388(23): Add ‘show_group’ parameter to *note
     traceback.format_exception_only(): a50, which allows to format
     *note ExceptionGroup: 4d3. instances.

   - gh-79033(24): Another attempt at fixing *note
     asyncio.Server.wait_closed(): 1a27.  It now blocks until both
     conditions are true: the server is closed, 'and' there are no more
     active connections.  (This means that in some cases where in 3.12.0
     this function would 'incorrectly' have returned immediately, it
     will now block; in particular, when there are no active connections
     but the server hasn’t been closed yet.)

   - gh-111259(25): Optimize recursive wildcards in *note pathlib: a8.

   - gh-111295(26): Fix *note time: f4. not checking for errors when
     initializing.

   - gh-111253(27): Add error checking during ‘_socket’ module init.

   - gh-111251(28): Fix ‘_blake2’ not checking for errors when
     initializing.

   - gh-111233(29): Fix *note select: c6. not checking for errors when
     initializing.

   - gh-111230(30): Fix *note ssl: d5. not checking for errors when
     initializing.

   - gh-111174(31): Fix crash in *note io.BytesIO.getbuffer(): 13f9.
     called repeatedly for empty BytesIO.

   - gh-111187(32): Postpone removal version for
     locale.getdefaultlocale() to Python 3.15.

   - gh-111159(33): Fix *note doctest: 3e. output comparison for
     exceptions with notes.

   - gh-110910(34): Fix invalid state handling in *note
     asyncio.TaskGroup: 4d2. and *note asyncio.Timeout: 1a28.  They now
     raise proper RuntimeError if they are improperly used and are left
     in consistent state after this.

   - gh-111092(35): Make turtledemo run without default root enabled.

   - gh-110944(36): Support alias and convenience vars for *note pdb:
     aa. completion

   - gh-110745(37): Added 'newline' parameter to *note
     pathlib.Path.read_text(): 1047.  Patch by Junya Okabe.

   - gh-84583(38): Make *note pdb: aa. enter post-mortem mode even for
     *note SyntaxError: 18e.

   - gh-80675(39): Set ‘f_trace_lines = True’ on all frames upon *note
     pdb.set_trace(): 272.

   - gh-110771(40): Expose the setup and cleanup portions of
     ‘asyncio.run_forever()’ as the standalone methods
     ‘asyncio.run_forever_setup()’ and ‘asyncio.run_forever_cleanup()’.
     This allows for tighter integration with GUI event loops.

   - gh-110774(41): Support setting the *note asyncio.Runner: 2f5.
     loop_factory kwarg in *note unittest.IsolatedAsyncioTestCase: 361.

   - gh-110392(42): Fix *note tty.setraw(): 1a29. and *note
     tty.setcbreak(): 19dd.: previously they returned partially modified
     list of the original tty attributes.  *note tty.cfmakeraw(): 1a2a.
     and *note tty.cfmakecbreak(): 19de. now make a copy of the list of
     special characters before modifying it.

   - gh-59013(43): Make line number of function breakpoint more precise
     in *note pdb: aa.

   - gh-88434(44): Emit deprecation warning for non-integer numbers in
     *note gettext: 67. functions and methods that consider plural forms
     even if the translation was not found.

   - gh-110395(45): Ensure that *note select.kqueue(): 1a2b. objects
     correctly appear as closed in forked children, to prevent
     operations on an invalid file descriptor.

   - gh-110196(46): Add ‘__reduce__’ method to ‘IPv6Address’ in order to
     keep ‘scope_id’

   - gh-109747(47): Improve errors for unsupported look-behind patterns.
     Now re.error is raised instead of OverflowError or RuntimeError for
     too large width of look-behind pattern.

   - gh-109466(48): Add the *note ipaddress.IPv4Address.ipv6_mapped:
     50c. property, which returns the IPv4-mapped IPv6 address.

   - gh-85098(49): Implement the CLI of the *note symtable: de. module
     and improve the repr of *note Symbol: 289.

   - gh-108791(50): Improved error handling in *note pdb: aa. command
     line interface, making it produce more concise error messages.

   - gh-105931(51): Change *note compileall: 21. to only strip the
     stripdir prefix from the full path recorded in the compiled ‘.pyc’
     file, when the prefix matches the start of the full path in its
     entirety.  When the prefix does not match, no stripping is
     performed and a warning to this effect is displayed.

     Previously all path components of the stripdir prefix that matched
     the full path were removed, while those that did not match were
     left alone (including ones interspersed between matching
     components).

   - gh-107431(52): Make the ‘DictProxy’ and ‘ListProxy’ types in *note
     multiprocessing.managers: 9b. *note Generic Alias Types: 8c2. for
     ‘[]’ use in typing contexts.

   - gh-72904(53): Add *note glob.translate(): 4fc.  This function
     converts a pathname with shell-style wildcards to a regular
     expression.

   - gh-90026(54): Define ‘USE_XATTRS’ on Cygwin so that XATTR-related
     functions in the *note os: a5. module become available.

   - gh-90890(55): New methods *note mailbox.Maildir.get_info(): 1a2c,
     *note mailbox.Maildir.set_info(): 1a2d, *note
     mailbox.Maildir.get_flags(): 1a2e, *note
     mailbox.Maildir.set_flags(): 1a2f, *note
     mailbox.Maildir.add_flag(): 1a30, *note
     mailbox.Maildir.remove_flag(): 1a31.  These methods speed up
     accessing a message’s info and/or flags and are useful when it is
     not necessary to access the message’s contents, as when iterating
     over a Maildir to find messages with specific flags.

   - gh-102956(56): Fix returning of empty byte strings after seek in
     zipfile module

   - gh-102895(57): Added a parameter ‘local_exit’ for *note
     code.interact(): 1878. to prevent ‘exit()’ and ‘quit’ from closing
     ‘sys.stdin’ and raise ‘SystemExit’.

   - gh-97928(58): Change the behavior of ‘tkinter.Text.count()’.  It
     now always returns an integer if one or less counting options are
     specified.  Previously it could return a single count as a 1-tuple,
     an integer (only if option ‘"update"’ was specified) or ‘None’ if
     no items found.  The result is now the same if ‘wantobjects’ is set
     to ‘0’.

   - gh-96954(59): Switch the storage of the unicode codepoint names to
     use a different data-structure, a directed acyclic word graph(60).
     This makes the unicodedata shared library about 440 KiB smaller.
     Contributed by Carl Friedrich Bolz-Tereick using code from the PyPy
     project.

   - gh-73561(61): Omit the interface scope from an IPv6 address when
     used as Host header by *note http.client: 73.

   - gh-86826(62): ‘zipinfo’ now supports the full range of values in
     the TZ string determined by RFC 8536 and detects all invalid
     formats.  Both Python and C implementations now raise exceptions of
     the same type on invalid data.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/111942

   (2) https://github.com/python/cpython/issues/111995

   (3) https://github.com/python/cpython/issues/109538

   (4) https://github.com/python/cpython/issues/111942

   (5) https://github.com/python/cpython/issues/111460

   (6) https://github.com/python/cpython/issues/103791

   (7) https://github.com/python/cpython/issues/111835

   (8) https://github.com/python/cpython/issues/111804

   (9) https://github.com/python/cpython/issues/111841

   (10) https://github.com/python/cpython/issues/111768

   (11) https://github.com/python/cpython/issues/80731

   (12) https://github.com/python/cpython/issues/111541

   (13) https://github.com/python/cpython/issues/111719

   (14) https://github.com/python/cpython/issues/111482

   (15) https://github.com/python/cpython/issues/110894

   (16) https://github.com/python/cpython/issues/111531

   (17) https://github.com/python/cpython/issues/111246

   (18) https://github.com/python/cpython/issues/111356

   (19) https://github.com/python/cpython/issues/66425

   (20) https://github.com/python/cpython/issues/111429

   (21) https://github.com/python/cpython/issues/111342

   (22) https://github.com/python/cpython/issues/68166

   (23) https://github.com/python/cpython/issues/111388

   (24) https://github.com/python/cpython/issues/79033

   (25) https://github.com/python/cpython/issues/111259

   (26) https://github.com/python/cpython/issues/111295

   (27) https://github.com/python/cpython/issues/111253

   (28) https://github.com/python/cpython/issues/111251

   (29) https://github.com/python/cpython/issues/111233

   (30) https://github.com/python/cpython/issues/111230

   (31) https://github.com/python/cpython/issues/111174

   (32) https://github.com/python/cpython/issues/111187

   (33) https://github.com/python/cpython/issues/111159

   (34) https://github.com/python/cpython/issues/110910

   (35) https://github.com/python/cpython/issues/111092

   (36) https://github.com/python/cpython/issues/110944

   (37) https://github.com/python/cpython/issues/110745

   (38) https://github.com/python/cpython/issues/84583

   (39) https://github.com/python/cpython/issues/80675

   (40) https://github.com/python/cpython/issues/110771

   (41) https://github.com/python/cpython/issues/110774

   (42) https://github.com/python/cpython/issues/110392

   (43) https://github.com/python/cpython/issues/59013

   (44) https://github.com/python/cpython/issues/88434

   (45) https://github.com/python/cpython/issues/110395

   (46) https://github.com/python/cpython/issues/110196

   (47) https://github.com/python/cpython/issues/109747

   (48) https://github.com/python/cpython/issues/109466

   (49) https://github.com/python/cpython/issues/85098

   (50) https://github.com/python/cpython/issues/108791

   (51) https://github.com/python/cpython/issues/105931

   (52) https://github.com/python/cpython/issues/107431

   (53) https://github.com/python/cpython/issues/72904

   (54) https://github.com/python/cpython/issues/90026

   (55) https://github.com/python/cpython/issues/90890

   (56) https://github.com/python/cpython/issues/102956

   (57) https://github.com/python/cpython/issues/102895

   (58) https://github.com/python/cpython/issues/97928

   (59) https://github.com/python/cpython/issues/96954

   (60) 
https://en.wikipedia.org/wiki/Deterministic_acyclic_finite_state_automaton

   (61) https://github.com/python/cpython/issues/73561

   (62) https://github.com/python/cpython/issues/86826


File: python.info,  Node: Tests<18>,  Next: Build<21>,  Prev: Library<62>,  Up: Python 3 13 0 alpha 2

1.24.24.3 Tests
...............

   - gh-111808(1): Make the default value of
     ‘test.support.infinite_recursion()’ to be conditional based on
     whether optimizations were used when compiling the interpreter.
     This helps with platforms like WASI whose stack size is greatly
     restricted in debug builds.

   - gh-110722(2): Gathering line coverage of standard libraries within
     the regression test suite is now precise, as well as much faster.
     Patch by Łukasz Langa.

   - gh-110367(3): Make regrtest ‘--verbose3’ option compatible with
     ‘--huntrleaks -jN’ options.  The ‘./python -m test -j1 -R 3:3
     --verbose3’ command now works as expected.  Patch by Victor
     Stinner.

   - gh-111165(4): Remove no longer used functions ‘run_unittest()’ and
     ‘run_doctest()’ from the *note test.support: ea. module.

   - gh-110932(5): Fix regrtest if the ‘SOURCE_DATE_EPOCH’ environment
     variable is defined: use the variable value as the random seed.
     Patch by Victor Stinner.

   - gh-110995(6): test_gdb: Fix detection of gdb built without Python
     scripting support.  Patch by Victor Stinner.

   - gh-110918(7): Test case matching patterns specified by options
     ‘--match’, ‘--ignore’, ‘--matchfile’ and ‘--ignorefile’ are now
     tested in the order of specification, and the last match determines
     whether the test case be run or ignored.

   - gh-108747(8): Add unit test for ‘usercustomize’ and ‘sitecustomize’
     hooks from *note site: cc.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/111808

   (2) https://github.com/python/cpython/issues/110722

   (3) https://github.com/python/cpython/issues/110367

   (4) https://github.com/python/cpython/issues/111165

   (5) https://github.com/python/cpython/issues/110932

   (6) https://github.com/python/cpython/issues/110995

   (7) https://github.com/python/cpython/issues/110918

   (8) https://github.com/python/cpython/issues/108747


File: python.info,  Node: Build<21>,  Next: Windows<19>,  Prev: Tests<18>,  Up: Python 3 13 0 alpha 2

1.24.24.4 Build
...............

   - gh-96954(1): Make ‘make regen-unicodedata’ work for out-of-tree
     builds of CPython.

   - gh-112088(2): Add ‘Tools/build/regen-configure.sh’ script to
     regenerate the ‘configure’ with an Ubuntu container image.  The
     ‘quay.io/tiran/cpython_autoconf:271’ container image
     (tiran/cpython_autoconf(3)) is no longer used.  Patch by Victor
     Stinner.

   - gh-111046(4): For wasi-threads, memory is now exported to fix
     compatibility issues with some wasm runtimes.

   - gh-110828(5): AIX 32bit needs ‘-latomic’ to build the ‘_testcapi’
     extension module.

   - gh-85283(6): The ‘errno’, ‘md5’, ‘resource’, ‘winsound’,
     ‘_ctypes_test’, ‘_multiprocessing.posixshmem’, ‘_scproxy’, ‘_stat’,
     ‘_testimportmultiple’ and ‘_uuid’ C extensions are now built with
     the *note limited C API: 637.  Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/96954

   (2) https://github.com/python/cpython/issues/112088

   (3) https://github.com/tiran/cpython_autoconf

   (4) https://github.com/python/cpython/issues/111046

   (5) https://github.com/python/cpython/issues/110828

   (6) https://github.com/python/cpython/issues/85283


File: python.info,  Node: Windows<19>,  Next: macOS<12>,  Prev: Build<21>,  Up: Python 3 13 0 alpha 2

1.24.24.5 Windows
.................

   - gh-111856(1): Fixes *note fstat(): f8e. on file systems that do not
     support file ID requests.  This includes FAT32 and exFAT.

   - gh-111293(2): Fix *note os.DirEntry.inode: 1a35. dropping higher 64
     bits of a file id on some filesystems on Windows.

   - gh-110913(3): WindowsConsoleIO now correctly chunks large buffers
     without splitting up UTF-8 sequences.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/111856

   (2) https://github.com/python/cpython/issues/111293

   (3) https://github.com/python/cpython/issues/110913


File: python.info,  Node: macOS<12>,  Next: IDLE<12>,  Prev: Windows<19>,  Up: Python 3 13 0 alpha 2

1.24.24.6 macOS
...............

   - gh-59703(1): For macOS framework builds, in ‘getpath.c’ use the
     system ‘dladdr’ function to find the path to the shared library
     rather than depending on deprecated macOS APIs.

   - gh-110950(2): Update macOS installer to include an upstream Tcl/Tk
     fix for the ‘Secure coding is not enabled for restorable state!’
     warning encountered in Tkinter on macOS 14 Sonoma.

   - gh-111015(3): Ensure that IDLE.app and Python Launcher.app are
     installed with appropriate permissions on macOS builds.

   - gh-71383(4): Update macOS installer to include an upstream Tcl/Tk
     fix for the ‘ttk::ThemeChanged’ error encountered in Tkinter.

   - gh-92603(5): Update macOS installer to include a fix accepted by
     upstream Tcl/Tk for a crash encountered after the first *note
     tkinter.Tk(): 1994. instance is destroyed.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/59703

   (2) https://github.com/python/cpython/issues/110950

   (3) https://github.com/python/cpython/issues/111015

   (4) https://github.com/python/cpython/issues/71383

   (5) https://github.com/python/cpython/issues/92603


File: python.info,  Node: IDLE<12>,  Next: Tools/Demos<18>,  Prev: macOS<12>,  Up: Python 3 13 0 alpha 2

1.24.24.7 IDLE
..............

   - bpo-35668(1): Add docstrings to the IDLE debugger module.  Fix two
     bugs: initialize ‘Idb.botframe’ (should be in Bdb); in
     ‘Idb.in_rpc_code’, check whether ‘prev_frame’ is ‘None’ before
     trying to use it.  Greatly expand test_debugger.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35668


File: python.info,  Node: Tools/Demos<18>,  Next: C API<21>,  Prev: IDLE<12>,  Up: Python 3 13 0 alpha 2

1.24.24.8 Tools/Demos
.....................

   - gh-111903(1): Argument Clinic now supports the ‘@critical_section’
     directive that instructs Argument Clinic to generate a critical
     section around the function call, which locks the ‘self’ object in
     ‘--disable-gil’ builds.  Patch by Sam Gross.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/111903


File: python.info,  Node: C API<21>,  Prev: Tools/Demos<18>,  Up: Python 3 13 0 alpha 2

1.24.24.9 C API
...............

   - gh-112026(1): Add again the private ‘_PyThreadState_UncheckedGet()’
     function as an alias to the new public *note
     PyThreadState_GetUnchecked(): 423. function.  Patch by Victor
     Stinner.

   - gh-112026(2): Restore the removed
     ‘_PyDict_GetItemStringWithError()’ function.  It is used by numpy.
     Patch by Victor Stinner.

   - gh-112026(3): Restore removed private C API functions, macros and
     structures which have no simple replacement for now:

        * _PyDict_GetItem_KnownHash()

        * _PyDict_NewPresized()

        * _PyHASH_BITS

        * _PyHASH_IMAG

        * _PyHASH_INF

        * _PyHASH_MODULUS

        * _PyHASH_MULTIPLIER

        * _PyLong_Copy()

        * _PyLong_FromDigits()

        * _PyLong_New()

        * _PyLong_Sign()

        * _PyObject_CallMethodId()

        * _PyObject_CallMethodNoArgs()

        * _PyObject_CallMethodOneArg()

        * _PyObject_CallOneArg()

        * _PyObject_EXTRA_INIT

        * _PyObject_FastCallDict()

        * _PyObject_GetAttrId()

        * _PyObject_Vectorcall()

        * _PyObject_VectorcallMethod()

        * _PyStack_AsDict()

        * _PyThread_CurrentFrames()

        * _PyUnicodeWriter structure

        * _PyUnicodeWriter_Dealloc()

        * _PyUnicodeWriter_Finish()

        * _PyUnicodeWriter_Init()

        * _PyUnicodeWriter_Prepare()

        * _PyUnicodeWriter_PrepareKind()

        * _PyUnicodeWriter_WriteASCIIString()

        * _PyUnicodeWriter_WriteChar()

        * _PyUnicodeWriter_WriteLatin1String()

        * _PyUnicodeWriter_WriteStr()

        * _PyUnicodeWriter_WriteSubstring()

        * _PyUnicode_AsString()

        * _PyUnicode_FromId()

        * _PyVectorcall_Function()

        * _Py_IDENTIFIER()

        * _Py_c_abs()

        * _Py_c_diff()

        * _Py_c_neg()

        * _Py_c_pow()

        * _Py_c_prod()

        * _Py_c_quot()

        * _Py_c_sum()

        * _Py_static_string()

        * _Py_static_string_init()

     Patch by Victor Stinner.

   - gh-112026(4): Add again ‘<ctype.h>’ and ‘<unistd.h>’ includes in
     ‘Python.h’, but don’t include them in the limited C API version
     3.13 and newer.  Patch by Victor Stinner.

   - gh-111956(5): Add internal-only one-time initialization API:
     ‘_PyOnceFlag’ and ‘_PyOnceFlag_CallOnce’.

   - gh-111262(6): Add *note PyDict_Pop(): 422. and *note
     PyDict_PopString(): 5e5. functions: remove a key from a dictionary
     and optionally return the removed value.  This is similar to *note
     dict.pop(): 5e6, but without the default value and not raising
     *note KeyError: 5e7. if the key missing.  Patch by Stefan Behnel
     and Victor Stinner.

   - gh-111863(7): Rename ‘Py_NOGIL’ to ‘Py_GIL_DISABLED’.  Patch by
     Hugo van Kemenade.

   - gh-111138(8): Add *note PyList_Extend(): 600. and *note
     PyList_Clear(): 601. functions: similar to Python ‘list.extend()’
     and ‘list.clear()’ methods.  Patch by Victor Stinner.

   - gh-108765(9): On Windows, ‘Python.h’ no longer includes the
     ‘<stddef.h>’ standard header file.  If needed, it should now be
     included explicitly.  Patch by Victor Stinner.

   - gh-111569(10): Implement «Python Critical Sections» from PEP
     703(11).  These are macros to help replace the GIL with per-object
     locks in the ‘--disable-gil’ build of CPython.  The macros are
     no-ops in the default build.

   - gh-111506(12): In the limited C API version 3.13, *note
     Py_SET_REFCNT(): aaa. function is now implemented as an opaque
     function call.  Patch by Victor Stinner.

   - gh-108082(13): Add *note PyErr_FormatUnraisable(): 5f1. function.

   - gh-110964(14): Move the undocumented private _PyArg functions and
     _PyArg_Parser structure to internal C API (‘pycore_modsupport.h’).
     Patch by Victor Stinner.

   - gh-110815(15): Support non-ASCII keyword names in *note
     PyArg_ParseTupleAndKeywords(): 624.

   - gh-109587(16): Introduced
     ‘PyUnstable_PerfTrampoline_CompileCode()’,
     ‘PyUnstable_PerfTrampoline_SetPersistAfterFork()’ and
     ‘PyUnstable_CopyPerfMapFile()’.  These functions allow extension
     modules to initialize trampolines eagerly, after the application is
     «warmed up».  This makes it possible to have perf-trampolines
     running in an always-enabled fashion.

   - gh-85283(17): Add the *note PySys_Audit(): 613. function to the
     limited C API. Patch by Victor Stinner.

   - gh-85283(18): Add *note PyMem_RawMalloc(): 631, *note
     PyMem_RawCalloc(): 632, *note PyMem_RawRealloc(): 633. and *note
     PyMem_RawFree(): 634. to the limited C API. Patch by Victor
     Stinner.

   - gh-106672(19): Functions *note PyDict_GetItem(): 628, *note
     PyDict_GetItemString(): 629, *note PyMapping_HasKey(): 620, *note
     PyMapping_HasKeyString(): 622, *note PyObject_HasAttr(): 61c, *note
     PyObject_HasAttrString(): 61e, and *note PySys_GetObject(): 62a,
     which clear all errors occurred during calling the function, report
     now them using *note sys.unraisablehook(): 508.

   - gh-67565(20): Remove redundant C-contiguity check in ‘getargs.c’,
     *note binascii: 11, *note ssl: d5. and Argument Clinic.  Patched by
     Stefan Krah and Furkan Onder

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/112026

   (2) https://github.com/python/cpython/issues/112026

   (3) https://github.com/python/cpython/issues/112026

   (4) https://github.com/python/cpython/issues/112026

   (5) https://github.com/python/cpython/issues/111956

   (6) https://github.com/python/cpython/issues/111262

   (7) https://github.com/python/cpython/issues/111863

   (8) https://github.com/python/cpython/issues/111138

   (9) https://github.com/python/cpython/issues/108765

   (10) https://github.com/python/cpython/issues/111569

   (11) https://peps.python.org/pep-0703/

   (12) https://github.com/python/cpython/issues/111506

   (13) https://github.com/python/cpython/issues/108082

   (14) https://github.com/python/cpython/issues/110964

   (15) https://github.com/python/cpython/issues/110815

   (16) https://github.com/python/cpython/issues/109587

   (17) https://github.com/python/cpython/issues/85283

   (18) https://github.com/python/cpython/issues/85283

   (19) https://github.com/python/cpython/issues/106672

   (20) https://github.com/python/cpython/issues/67565


File: python.info,  Node: Python 3 13 0 alpha 1,  Next: Python 3 12 0 beta 1,  Prev: Python 3 13 0 alpha 2,  Up: Changelog

1.24.25 Python 3.13.0 alpha 1
-----------------------------

'Release date: 2023-10-13'

* Menu:

* Security: Security<21>.
* Core and Builtins: Core and Builtins<58>.
* Library: Library<63>.
* Documentation: Documentation<19>.
* Tests: Tests<19>.
* Build: Build<22>.
* Windows: Windows<20>.
* macOS: macOS<13>.
* IDLE: IDLE<13>.
* Tools/Demos: Tools/Demos<19>.
* C API: C API<22>.


File: python.info,  Node: Security<21>,  Next: Core and Builtins<58>,  Up: Python 3 13 0 alpha 1

1.24.25.1 Security
..................

   - gh-108310(1): Fixed an issue where instances of *note
     ssl.SSLSocket: ae9. were vulnerable to a bypass of the TLS
     handshake and included protections (like certificate verification)
     and treating sent unencrypted data as if it were post-handshake TLS
     encrypted data.  Security issue reported as CVE 2023-40217(2) by
     Aapo Oksman.  Patch by Gregory P. Smith.

   - gh-107774(3): PEP 669 specifies that
     ‘sys.monitoring.register_callback’ will generate an audit event.
     Pre-releases of Python 3.12 did not generate the audit event.  This
     is now fixed.

   - gh-102988(4): Reverted the *note email.utils: 54. security
     improvement change released in 3.12beta4 that unintentionally
     caused *note email.utils.getaddresses: 4f4. to fail to parse email
     addresses with a comma in the quoted name field.  See gh-106669(5).

   - gh-99108(6): Refresh our new HACL* built-in *note hashlib: 6c. code
     from upstream.  Built-in SHA2 should be faster and an issue with
     SHA3 on 32-bit platforms is fixed.

   - gh-102509(7): Start initializing ‘ob_digit’ during creation of
     *note PyLongObject: 39e. objects.  Patch by Illia Volochii.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/108310

   (2) https://www.cve.org/CVERecord?id=CVE-2023-40217

   (3) https://github.com/python/cpython/issues/107774

   (4) https://github.com/python/cpython/issues/102988

   (5) https://github.com/python/cpython/issues/106669

   (6) https://github.com/python/cpython/issues/99108

   (7) https://github.com/python/cpython/issues/102509


File: python.info,  Node: Core and Builtins<58>,  Next: Library<63>,  Prev: Security<21>,  Up: Python 3 13 0 alpha 1

1.24.25.2 Core and Builtins
...........................

   - gh-110782(1): Fix crash when *note typing.TypeVar: 487. is
     constructed with a keyword argument.  Patch by Jelle Zijlstra.

   - gh-110752(2): Reset ‘ceval.eval_breaker’ in ‘interpreter_clear()’

   - gh-110721(3): Use the *note traceback: 104. implementation for the
     default ‘PyErr_Display()’ functionality.  Patch by Pablo Galindo

   - gh-110696(4): Fix incorrect error message for invalid argument
     unpacking.  Patch by Pablo Galindo

   - gh-104169(5): Split the tokenizer into two separate directories: -
     One part includes the actual lexeme producing logic and lives in
     ‘Parser/lexer’.  - The second part wraps the lexer according to the
     different tokenization modes we have (string, utf-8, file,
     interactive, readline) and lives in ‘Parser/tokenizer’.

   - gh-110688(6): Remove undocumented ‘test_c_api’ method from *note
     set: 184, which was only defined for testing purposes under
     ‘Py_DEBUG’.  Now we have proper CAPI tests.

   - gh-104584(7): Fix a reference leak when running with ‘PYTHONUOPS’
     or *note -X uops: 16f. enabled.

   - gh-110514(8): Add ‘PY_THROW’ to *note sys.setprofile(): 1705.
     events

   - gh-110489(9): Optimise *note math.ceil(): 15c6. when the input is
     exactly a float, resulting in about a 10% improvement.

   - gh-110455(10): Guard ‘assert(tstate->thread_id > 0)’ with ‘#ifndef
     HAVE_PTHREAD_STUBS’.  This allows for for pydebug builds to work
     under WASI which (currently) lacks thread support.

   - gh-110309(11): Remove unnecessary empty constant nodes in the ast
     of f-string specs.

   - gh-110259(12): Correctly identify the format spec in f-strings
     (with single or triple quotes) that have multiple lines in the
     expression part and include a formatting spec.  Patch by Pablo
     Galindo

   - gh-110237(13): Fix missing error checks for calls to
     ‘PyList_Append’ in ‘_PyEval_MatchClass’.

   - gh-110164(14): regrtest: If the ‘SOURCE_DATE_EPOCH’ environment
     variable is defined, regrtest now disables tests randomization.
     Patch by Victor Stinner.

   - gh-109889(15): Fix the compiler’s redundant NOP detection algorithm
     to skip over NOPs with no line number when looking for the next
     instruction’s lineno.

   - gh-109853(16): ‘sys.path[0]’ is now set correctly for
     subinterpreters.

   - gh-109923(17): Set line number on the ‘POP_TOP’ that follows a
     ‘RETURN_GENERATOR’.

   - gh-105716(18): Subinterpreters now correctly handle the case where
     they have threads running in the background.  Before, such threads
     would interfere with cleaning up and destroying them, as well as
     prevent running another script.

   - gh-109369(19): The internal eval_breaker and supporting flags, plus
     the monitoring version have been merged into a single atomic
     integer to speed up checks.

   - gh-109823(20): Fix bug where compiler does not adjust labels when
     removing an empty basic block which is a jump target.

   - gh-109793(21): The main thread no longer exits prematurely when a
     subinterpreter is cleaned up during runtime finalization.  The bug
     was a problem particularly because, when triggered, the Python
     process would always return with a 0 exitcode, even if it failed.

   - gh-109719(22): Fix missing jump target labels when compiler
     reorders cold/warm blocks.

   - gh-109595(23): Add *note -X cpu_count: 16f. command line option to
     override return results of *note os.cpu_count(): 4dc. and *note
     os.process_cpu_count(): 4db.  This option is useful for users who
     need to limit CPU resources of a container system without having to
     modify the container (application code).  Patch by Donghee Na.

   - gh-109627(24): Fix bug where the compiler does not assign a new
     jump target label to a duplicated small exit block.

   - gh-109596(25): Fix some tokens in the grammar that were incorrectly
     marked as soft keywords.  Also fix some repeated rule names and
     ensure that repeated rules are not allowed.  Patch by Pablo Galindo

   - gh-109496(26): On a Python built in debug mode, *note Py_DECREF():
     791. now calls ‘_Py_NegativeRefcount()’ if the object is a dangling
     pointer to deallocated memory: memory filled with ‘0xDD’ «dead
     byte» by the debug hook on memory allocators.  The fix is to check
     the reference count 'before' checking for ‘_Py_IsImmortal()’.
     Patch by Victor Stinner.

   - gh-107265(27): Deopt opcodes hidden by the executor when base
     opcode is needed

   - gh-109371(28): Deopted instructions correctly for tool
     initialization and modified the incorrect assertion in
     instrumentation, when a previous tool already sets INSTRUCTION
     events

   - gh-105658(29): Fix bug where the line trace of an except block
     ending with a conditional includes an excess event with the line of
     the conditional expression.

   - gh-109219(30): Fix compiling type param scopes that use a name
     which is also free in an inner scope.

   - gh-109351(31): Fix crash when compiling an invalid AST involving a
     named (walrus) expression.

   - gh-109341(32): Fix crash when compiling an invalid AST involving a
     *note ast.TypeAlias: 1a3d.

   - gh-109195(33): Fix source location for the ‘LOAD_*’ instruction
     preceding a ‘LOAD_SUPER_ATTR’ to load the ‘super’ global (or
     shadowing variable) so that it encompasses only the name ‘super’
     and not the following parentheses.

   - gh-109256(34): Opcode IDs for specialized opcodes are allocated in
     their own range to improve stability of the IDs for the “real”
     opcodes.

   - gh-109216(35): Fix possible memory leak in *note BUILD_MAP: 369.

   - gh-109207(36): Fix a SystemError in ‘__repr__’ of symtable entry
     object.

   - gh-109179(37): Fix bug where the C traceback display drops notes
     from *note SyntaxError: 18e.

   - gh-109118(38): Disallow nested scopes (lambdas, generator
     expressions, and comprehensions) within PEP 695 annotation scopes
     that are nested within classes.

   - gh-109156(39): Add tests for de-instrumenting instructions while
     keeping the instrumentation for lines

   - gh-109114(40): Relax the detection of the error message for invalid
     lambdas inside f-strings to not search for arbitrary replacement
     fields to avoid false positives.  Patch by Pablo Galindo

   - gh-105848(41): Add a new *note CALL_KW: 372. opcode, used for calls
     containing keyword arguments.  Also, fix a possible crash when
     jumping over method calls in a debugger.

   - gh-109052(42): Use the base opcode when comparing code objects to
     avoid interference from instrumentation

   - gh-109118(43): Fix interpreter crash when a NameError is raised
     inside the type parameters of a generic class.

   - gh-88943(44): Improve syntax error for non-ASCII character that
     follows a numerical literal.  It now points on the invalid
     non-ASCII character, not on the valid numerical literal.

   - gh-108976(45): Fix crash that occurs after de-instrumenting a code
     object in a monitoring callback.

   - gh-108732(46): Make iteration variables of module- and class-scoped
     comprehensions visible to pdb and other tools that use
     ‘frame.f_locals’ again.

   - gh-108959(47): Fix caret placement for error locations for
     subscript and binary operations that involve non-semantic
     parentheses and spaces.  Patch by Pablo Galindo

   - gh-104584(48): Fix a crash when running with ‘PYTHONUOPS’ or *note
     -X uops: 16f. enabled and an error occurs during optimization.

   - gh-108727(49): Define ‘tp_dealloc’ for ‘CounterOptimizer_Type’.
     This fixes a segfault on deallocation.

   - gh-108520(50): Fix
     ‘multiprocessing.synchronize.SemLock.__setstate__()’ to properly
     initialize ‘multiprocessing.synchronize.SemLock._is_fork_ctx’.
     This fixes a regression when passing a SemLock across nested
     processes.

     Rename ‘multiprocessing.synchronize.SemLock.is_fork_ctx’ to
     ‘multiprocessing.synchronize.SemLock._is_fork_ctx’ to avoid
     exposing it as public API.

   - gh-108654(51): Restore locals shadowed by an inlined comprehension
     if the comprehension raises an exception.

   - gh-108488(52): Change the initialization of inline cache entries so
     that the cache entry for ‘JUMP_BACKWARD’ is initialized to zero,
     instead of the ‘adaptive_counter_warmup()’ value used for all other
     instructions.  This counter, unique among instructions, counts up
     from zero.

   - gh-108716(53): Turn off deep-freezing of code objects.  Modules are
     still frozen, so that a file system search is not needed for common
     modules.

   - gh-108614(54): Add RESUME_CHECK instruction, to avoid having to
     handle instrumentation, signals, and contexts switches in the tier
     2 execution engine.

   - gh-108487(55): Move an assert that would cause a spurious crash in
     a devious case that should only trigger deoptimization.

   - gh-106176(56): Use a ‘WeakValueDictionary’ to track the lists
     containing the modules each thread is currently importing.  This
     helps avoid a reference leak from keeping the list around longer
     than necessary.  Weakrefs are used as GC can’t interrupt the
     cleanup.

   - gh-105481(57): The regen-opcode build stage was removed and its
     work is now done in regen-cases.

   - gh-107901(58): Fix missing line number on *note JUMP_BACKWARD: 91b.
     at the end of a for loop.

   - gh-108113(59): The *note compile(): 4b2. built-in can now accept a
     new flag, ‘ast.PyCF_OPTIMIZED_AST’, which is similar to
     ‘ast.PyCF_ONLY_AST’ except that the returned ‘AST’ is optimized
     according to the value of the ‘optimize’ argument.

     *note ast.parse(): 1c2. now accepts an optional argument ‘optimize’
     which is passed on to the *note compile(): 4b2. built-in.  This
     makes it possible to obtain an optimized ‘AST’.

   - gh-107971(60): Opcode IDs are generated from bytecodes.c instead of
     being hard coded in opcode.py.

   - gh-107944(61): Improve error message for function calls with bad
     keyword arguments.  Patch by Pablo Galindo

   - gh-108390(62): Raise an exception when setting a non-local event
     (‘RAISE’, ‘EXCEPTION_HANDLED’, etc.)  in
     ‘sys.monitoring.set_local_events’.

     Fixes crash when tracing in recursive calls to Python classes.

   - gh-108035(63): Remove the ‘_PyCFrame’ struct, moving the pointer to
     the current interpreter frame back to the threadstate, as it was
     for 3.10 and earlier.  The ‘_PyCFrame’ existed as a performance
     optimization for tracing.  Since PEP 669 has been implemented, this
     optimization no longer applies.

   - gh-91051(64): Fix abort / segfault when using all eight type
     watcher slots, on platforms where ‘char’ is signed by default.

   - gh-106581(65): Fix possible assertion failures and missing
     instrumentation events when ‘PYTHONUOPS’ or *note -X uops: 16f. is
     enabled.

   - gh-107526(66): Revert converting ‘vars’, ‘dir’, ‘next’, ‘getattr’,
     and ‘iter’ to argument clinic.

   - gh-84805(67): Autogenerate signature for *note METH_NOARGS: 16db.
     and *note METH_O: 170e. extension functions.

   - gh-107758(68): Make the ‘dump_stack()’ routine used by the
     ‘lltrace’ feature (low-level interpreter debugging) robust against
     recursion by ensuring that it never calls a ‘__repr__’ method
     implemented in Python.  Also make the similar output for Tier-2
     uops appear on ‘stdout’ (instead of ‘stderr’), to match the
     ‘lltrace’ code in ceval.c.

   - gh-107659(69): Add docstrings for *note ctypes.pointer(): 1a3e. and
     *note ctypes.POINTER(): 1f1.

   - gh-105848(70): Modify the bytecode so that the actual callable for
     a *note CALL: 916. is at a consistent position on the stack
     (regardless of whether or not bound-method-calling optimizations
     are active).

   - gh-107674(71): Fixed performance regression in ‘sys.settrace’.

   - gh-107724(72): In pre-release versions of 3.12, up to rc1, the
     sys.monitoring callback function for the ‘PY_THROW’ event was
     missing the third, exception argument.  That is now fixed.

   - gh-84436(73): Skip reference count modifications for many known
     immortal objects.

   - gh-107596(74): Specialize subscripting *note str: 169. objects by
     *note int: 19b. indexes.

   - gh-107080(75): Trace refs builds (‘--with-trace-refs’) were
     crashing when used with isolated subinterpreters.  The problematic
     global state has been isolated to each interpreter.  Other fixing
     the crashes, this change does not affect users.

   - gh-107557(76): Generate the cases needed for the barebones tier 2
     abstract interpreter for optimization passes in CPython.

   - gh-106608(77): Make ‘_PyUOpExecutorObject’ variable length.

   - gh-100964(78): Clear generators” exception state after ‘return’ to
     break reference cycles.

   - gh-107455(79): Improve error messages when converting an
     incompatible type to *note ctypes.c_char_p: 1a3f, *note
     ctypes.c_wchar_p: 1a40. and *note ctypes.c_void_p: 1a41.

   - gh-107263(80): Increase C recursion limit for functions other than
     the main interpreter from 800 to 1500.  This should allow functions
     like ‘list.__repr__’ and ‘json.dumps’ to handle all the inputs that
     they could prior to 3.12

   - gh-104584(81): Fix an issue which caused incorrect inline caches to
     be read when running with ‘PYTHONUOPS’ or *note -X uops: 16f.
     enabled.

   - gh-104432(82): Fix potential unaligned memory access on C APIs
     involving returned sequences of ‘char *’ pointers within the *note
     grp: 6a. and *note socket: d1. modules.  These were revealed using
     a ‘-fsaniziter=alignment’ build on ARM macOS. Patch by Christopher
     Chavez.

   - gh-106078(83): Isolate ‘_decimal’ (apply PEP 687(84)).  Patch by
     Charlie Zhao.

   - gh-106898(85): Add the exception as the third argument to
     ‘PY_UNIND’ callbacks in ‘sys.monitoring’.  This makes the
     ‘PY_UNWIND’ callback consistent with the other exception handling
     callbacks.

   - gh-106895(86): Raise a ‘ValueError’ when a monitoring callback
     function returns ‘DISABLE’ for events that cannot be disabled
     locally.

   - gh-106897(87): Add a ‘RERAISE’ event to ‘sys.monitoring’, which
     occurs when an exception is reraise, either explicitly by a plain
     ‘raise’ statement, or implicitly in an ‘except’ or ‘finally’ block.

   - gh-77377(88): Ensure that multiprocessing synchronization objects
     created in a fork context are not sent to a different process
     created in a spawn context.  This changes a segfault into an
     actionable RuntimeError in the parent process.

   - gh-106931(89): Statically allocated string objects are now interned
     globally instead of per-interpreter.  This fixes a situation where
     such a string would only be interned in a single interpreter.
     Normal string objects are unaffected.

   - gh-104621(90): Unsupported modules now always fail to be imported.

   - gh-107122(91): Add ‘dbm.ndbm.ndbm.clear()’ to *note dbm.ndbm: 38.
     Patch By Donghee Na.

   - gh-107122(92): Add ‘dbm.gnu.gdbm.clear()’ to *note dbm.gnu: 37.
     Patch By Donghee Na.

   - gh-107015(93): The ASYNC and AWAIT tokens are removed from the
     Grammar, which removes the possibility of making ‘async’ and
     ‘await’ soft keywords when using ‘feature_version<7’ in *note
     ast.parse(): 1c2.

   - gh-106917(94): Fix classmethod-style *note super(): 1a6. method
     calls (i.e., where the second argument to *note super(): 1a6, or
     the implied second argument drawn from ‘self/cls’ in the case of
     zero-arg super, is a type) when the target of the call is not a
     classmethod.

   - gh-105699(95): Python no longer crashes due an infrequent race when
     initializing per-interpreter interned strings.  The crash would
     manifest when the interpreter was finalized.

   - gh-105699(96): Python no longer crashes due to an infrequent race
     in setting ‘Py_FileSystemDefaultEncoding’ and
     ‘Py_FileSystemDefaultEncodeErrors’ (both deprecated), when
     simultaneously initializing two isolated subinterpreters.  Now they
     are only set during runtime initialization.

   - gh-106908(97): Fix various hangs, reference leaks, test failures,
     and tracing/introspection bugs when running with ‘PYTHONUOPS’ or
     *note -X uops: 16f. enabled.

   - gh-106092(98): Fix a segmentation fault caused by a use-after-free
     bug in ‘frame_dealloc’ when the trashcan delays the deallocation of
     a ‘PyFrameObject’.

   - gh-106485(99): Reduce the number of materialized instances
     dictionaries by dematerializing them when possible.

   - gh-106719(100): No longer suppress arbitrary errors in the
     ‘__annotations__’ getter and setter in the type and module types.

   - gh-106723(101): Propagate ‘frozen_modules’ to multiprocessing
     spawned process interpreters.

   - gh-104909(102): Split ‘LOAD_ATTR_INSTANCE_VALUE’ into micro-ops.

   - gh-104909(103): Split *note LOAD_GLOBAL: 1a42. specializations into
     micro-ops.

   - gh-106597(104): A new debug structure of offsets has been added to
     the ‘_PyRuntimeState’ that will help out-of-process debuggers and
     profilers to obtain the offsets to relevant interpreter structures
     in a way that is agnostic of how Python was compiled and that
     doesn’t require copying the headers.  Patch by Pablo Galindo

   - gh-106487(105): Allow the 'count' argument of *note str.replace():
     4b9. to be a keyword.  Patch by Hugo van Kemenade.

   - gh-96844(106): Improve error message of *note list.remove(): 1a43.
     Patch by Donghee Na.

   - gh-81283(107): Compiler now strips indents from docstrings.  It
     reduces ‘pyc’ file size 5% when the module is heavily documented.
     This change affects to ‘__doc__’ so tools like doctest will be
     affected.

   - gh-106396(108): When the format specification of an f-string
     expression is empty, the parser now generates an empty *note
     ast.JoinedStr: 1a44. node for it instead of an one-element *note
     ast.JoinedStr: 1a44. with an empty string *note ast.Constant: 2ef.

   - gh-100288(109): Specialize *note LOAD_ATTR: 705. for
     non-descriptors on the class.  Adds
     ‘LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES’ and
     ‘LOAD_ATTR_NONDESCRIPTOR_NO_DICT’.

   - gh-106008(110): Fix possible reference leaks when failing to
     optimize comparisons with *note None: 886. in the bytecode
     compiler.

   - gh-106145(111): Make ‘end_lineno’ and ‘end_col_offset’ required on
     ‘type_param’ ast nodes.

   - gh-106213(112): Changed the way that Emscripten call trampolines
     work for compatibility with Wasm/JS Promise integration.

   - gh-106182(113): *note sys.getfilesystemencoding(): e55. and *note
     sys.getfilesystemencodeerrors: ee4. now return interned Unicode
     object.

   - gh-106210(114): Removed Emscripten import trampoline as it was no
     longer necessary for Pyodide.

   - gh-104584(115): Added a new, experimental, tracing optimizer and
     interpreter (a.k.a.  «tier 2»).  This currently pessimizes, so
     don’t use yet – this is infrastructure so we can experiment with
     optimizing passes.  To enable it, pass ‘-Xuops’ or set
     ‘PYTHONUOPS=1’.  To get debug output, set ‘PYTHONUOPSDEBUG=N’ where
     ‘N’ is a debug level (0-4, where 0 is no debug output and 4 is
     excessively verbose).

   - gh-105775(116): *note LOAD_CLOSURE: 1a45. is now a pseudo-op.

   - gh-105730(117): Allow any callable other than type objects as the
     condition predicate in *note BaseExceptionGroup.split(): 18c0. and
     *note BaseExceptionGroup.subgroup(): 1a20.

   - gh-105979(118): Fix crash in ‘_imp.get_frozen_object()’ due to
     improper exception handling.

   - gh-106003(119): Add a new *note TO_BOOL: 1a46. instruction, which
     performs boolean conversions for *note POP_JUMP_IF_TRUE: 1a47,
     *note POP_JUMP_IF_FALSE: 1a48, and *note UNARY_NOT: 1a49. (which
     all expect exact *note bool: 3c3. values now).  Also, modify the
     oparg of *note COMPARE_OP: b63. to include an optional «boolean
     conversion» flag.

   - gh-98931(120): Ensure custom *note SyntaxError: 18e. error messages
     are raised for invalid imports with multiple targets.  Patch by
     Pablo Galindo

   - gh-105724(121): Improve ‘assert’ error messages by providing exact
     error range.

   - gh-105908(122): Fixed bug where gh-99111(123) breaks future import
     ‘barry_as_FLUFL’ in the Python REPL.

   - gh-105840(124): Fix possible crashes when specializing function
     calls with too many ‘__defaults__’.

   - gh-105831(125): Fix an f-string bug, where using a debug expression
     (the ‘=’ sign) that appears in the last line of a file results to
     the debug buffer that holds the expression text being one character
     too small.

   - gh-105800(126): Correctly issue *note SyntaxWarning: 1ae. in
     f-strings if invalid sequences are used.  Patch by Pablo Galindo

   - gh-105340(127): Include the comprehension iteration variable in
     ‘locals()’ inside a module- or class-scope comprehension.

   - gh-105331(128): Raise *note ValueError: 2ec. if the ‘delay’
     argument to *note asyncio.sleep(): c66. is a NaN (matching *note
     time.sleep(): 8ad.).

   - gh-105587(129): The runtime can’t guarantee that immortal objects
     will not be mutated by Extensions.  Thus, this modifies
     _PyStaticObject_CheckRefcnt to warn instead of asserting.

   - gh-105564(130): Don’t include artificil newlines in the ‘line’
     attribute of tokens in the APIs of the *note tokenize: 101. module.
     Patch by Pablo Galindo

   - gh-105549(131): Tokenize separately ‘NUMBER’ and ‘NAME’ tokens that
     are not ambiguous.  Patch by Pablo Galindo.

   - gh-105588(132): Fix an issue that could result in crashes when
     compiling malformed *note ast: 9. nodes.

   - gh-100987(133): Allow objects other than code objects as the
     «executable» in internal frames.  In the long term, this can help
     tools like Cython and PySpy interact more efficiently.  In the
     shorter term, it allows us to perform some optimizations more
     simply.

   - gh-105375(134): Fix bugs in the *note builtins: 13. module where
     exceptions could end up being overwritten.

   - gh-105375(135): Fix bug in the compiler where an exception could
     end up being overwritten.

   - gh-105375(136): Improve error handling in *note
     PyUnicode_BuildEncodingMap(): 1a4a. where an exception could end up
     being overwritten.

   - gh-105486(137): Change the repr of ‘ParamSpec’ list of args in
     ‘types.GenericAlias’.

   - gh-105678(138): Break the ‘MAKE_FUNCTION’ instruction into two
     parts, ‘MAKE_FUNCTION’ which makes the function and
     ‘SET_FUNCTION_ATTRIBUTE’ which sets the attributes on the function.
     This makes the stack effect of ‘MAKE_FUNCTION’ regular to ease
     optimization and code generation.

   - gh-105435(139): Fix spurious newline character if file ends on a
     comment without a newline.  Patch by Pablo Galindo

   - gh-105390(140): Correctly raise *note tokenize.TokenError: 765.
     exceptions instead of *note SyntaxError: 18e. for tokenize errors
     such as incomplete input.  Patch by Pablo Galindo

   - gh-105259(141): Don’t include newline character for trailing
     ‘NEWLINE’ tokens emitted in the *note tokenize: 101. module.  Patch
     by Pablo Galindo

   - gh-104635(142): Eliminate redundant *note STORE_FAST: 1a4b.
     instructions in the compiler.  Patch by Donghee Na and Carl Meyer.

   - gh-105324(143): Fix the main function of the *note tokenize: 101.
     module when reading from ‘sys.stdin’.  Patch by Pablo Galindo

   - gh-33092(144): Simplify and speed up interpreter for f-strings.
     Removes ‘FORMAT_VALUE’ opcode.  Add ‘CONVERT_VALUE’,
     ‘FORMAT_SIMPLE’ and ‘FORMAT_WITH_SPEC’ opcode.  Compiler emits more
     efficient sequence for each format expression.

   - gh-105229(145): Remove remaining two-codeunit superinstructions.
     All remaining superinstructions only take a single codeunit,
     simplifying instrumentation and quickening.

   - gh-105235(146): Prevent out-of-bounds memory access during
     ‘mmap.find()’ calls.

   - gh-98963(147): Restore the ability for a subclass of *note
     property: 4b4. to define ‘__slots__’ or otherwise be dict-less by
     ignoring failures to set a docstring on such a class.  This
     behavior had regressed in 3.12beta1.  An *note AttributeError: 5f0.
     where there had not previously been one was disruptive to existing
     code.

   - gh-104812(148): The «pending call» machinery now works for all
     interpreters, not just the main interpreter, and runs in all
     threads, not just the main thread.  Some calls are still only done
     in the main thread, ergo in the main interpreter.  This change does
     not affect signal handling nor the existing public C-API
     (‘Py_AddPendingCall()’), which both still only target the main
     thread.  The new functionality is meant strictly for internal use
     for now, since consequences of its use are not well understood yet
     outside some very restricted cases.  This change brings the
     capability in line with the intention when the state was made
     per-interpreter several years ago.

   - gh-105194(149): Do not escape with backslashes f-string format
     specifiers.  Patch by Pablo Galindo

   - gh-105229(150): Replace some dynamic superinstructions with single
     instruction equivalents.

   - gh-105162(151): Fixed bug in generator.close()/throw() where an
     inner iterator would be ignored when the outer iterator was
     instrumented.

   - gh-105164(152): Ensure annotations are set up correctly if the only
     annotation in a block is within a *note match: a10. block.  Patch
     by Jelle Zijlstra.

   - gh-105148(153): Make ‘_PyASTOptimizeState’ internal to ast_opt.c.
     Make ‘_PyAST_Optimize’ take two integers instead of a pointer to
     this struct.  This avoids the need to include pycore_compile.h in
     ast_opt.c.

   - gh-104799(154): Attributes of *note ast: 9. nodes that are lists
     now default to the empty list if omitted.  This means that some
     code that previously raised *note TypeError: 198. when the AST node
     was used will now proceed with the empty list instead.  Patch by
     Jelle Zijlstra.

   - gh-105111(155): Remove the old trashcan macros
     ‘Py_TRASHCAN_SAFE_BEGIN’ and ‘Py_TRASHCAN_SAFE_END’.  They should
     be replaced by the new macros ‘Py_TRASHCAN_BEGIN’ and
     ‘Py_TRASHCAN_END’.

   - gh-105035(156): Fix *note super(): 1a6. calls on types with custom
     *note tp_getattro: 1a4c. implementation (e.g.  meta-types.)

   - gh-105017(157): Show CRLF lines in the tokenize string attribute in
     both NL and NEWLINE tokens.  Patch by Marta Gómez.

   - gh-105013(158): Fix handling of multiline parenthesized lambdas in
     *note inspect.getsource(): 17ab.  Patch by Pablo Galindo

   - gh-105017(159): Do not include an additional final ‘NL’ token when
     parsing files having CRLF lines.  Patch by Marta Gómez.

   - gh-104976(160): Ensure that trailing ‘DEDENT’ ‘tokenize.TokenInfo’
     objects emitted by the *note tokenize: 101. module are reported as
     in Python 3.11.  Patch by Pablo Galindo

   - gh-104972(161): Ensure that the ‘line’ attribute in
     ‘tokenize.TokenInfo’ objects in the *note tokenize: 101. module are
     always correct.  Patch by Pablo Galindo

   - gh-104955(162): Fix signature for the new *note
     __release_buffer__(): 1a4d. slot.  Patch by Jelle Zijlstra.

   - gh-104690(163): Starting new threads and process creation through
     *note os.fork(): 4b6. during interpreter shutdown (such as from
     *note atexit: d. handlers) is no longer supported.  It can lead to
     race condition between the main Python runtime thread freeing
     thread states while internal *note threading: f3. routines are
     trying to allocate and use the state of just created threads.  Or
     forked children trying to use the mid-shutdown runtime and thread
     state in the child process.

   - gh-104879(164): Fix crash when accessing the ‘__module__’ attribute
     of type aliases defined outside a module.  Patch by Jelle Zijlstra.

   - gh-104825(165): Tokens emitted by the *note tokenize: 101. module
     do not include an implicit ‘\n’ character in the ‘line’ attribute
     anymore.  Patch by Pablo Galindo

   - gh-104770(166): If a generator returns a value upon being closed,
     the value is now returned by *note generator.close(): 177b.

   - gh-89091(167): Raise *note RuntimeWarning: 4d8. for unawaited async
     generator methods like *note asend(): ad8, *note athrow(): 71e. and
     *note aclose(): ad7.  Patch by Kumar Aditya.

   - gh-96663(168): Add a better, more introspect-able error message
     when setting attributes on classes without a ‘__dict__’ and no slot
     member for the attribute.

   - gh-93627(169): Update the Python pickle module implementation to
     match the C implementation of the pickle module.  For objects
     setting reduction methods like *note __reduce_ex__(): 1953. or
     *note __reduce__(): bc8. to ‘None’, pickling will result in a *note
     TypeError: 198.

   - gh-101006(170): Improve error handling when read *note marshal: 91.
     data.

   - gh-91095(171): Specializes calls to most Python classes.
     Specifically, any class that inherits from ‘object’, or another
     Python class, and does not override ‘__new__’.

     The specialized instruction does the following:

       1. Creates the object (by calling ‘object.__new__’)

       2. Pushes a shim frame to the frame stack (to cleanup after
          ‘__init__’)

       3. Pushes the frame for ‘__init__’ to the frame stack

     Speeds up the instantiation of most Python classes.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/110782

   (2) https://github.com/python/cpython/issues/110752

   (3) https://github.com/python/cpython/issues/110721

   (4) https://github.com/python/cpython/issues/110696

   (5) https://github.com/python/cpython/issues/104169

   (6) https://github.com/python/cpython/issues/110688

   (7) https://github.com/python/cpython/issues/104584

   (8) https://github.com/python/cpython/issues/110514

   (9) https://github.com/python/cpython/issues/110489

   (10) https://github.com/python/cpython/issues/110455

   (11) https://github.com/python/cpython/issues/110309

   (12) https://github.com/python/cpython/issues/110259

   (13) https://github.com/python/cpython/issues/110237

   (14) https://github.com/python/cpython/issues/110164

   (15) https://github.com/python/cpython/issues/109889

   (16) https://github.com/python/cpython/issues/109853

   (17) https://github.com/python/cpython/issues/109923

   (18) https://github.com/python/cpython/issues/105716

   (19) https://github.com/python/cpython/issues/109369

   (20) https://github.com/python/cpython/issues/109823

   (21) https://github.com/python/cpython/issues/109793

   (22) https://github.com/python/cpython/issues/109719

   (23) https://github.com/python/cpython/issues/109595

   (24) https://github.com/python/cpython/issues/109627

   (25) https://github.com/python/cpython/issues/109596

   (26) https://github.com/python/cpython/issues/109496

   (27) https://github.com/python/cpython/issues/107265

   (28) https://github.com/python/cpython/issues/109371

   (29) https://github.com/python/cpython/issues/105658

   (30) https://github.com/python/cpython/issues/109219

   (31) https://github.com/python/cpython/issues/109351

   (32) https://github.com/python/cpython/issues/109341

   (33) https://github.com/python/cpython/issues/109195

   (34) https://github.com/python/cpython/issues/109256

   (35) https://github.com/python/cpython/issues/109216

   (36) https://github.com/python/cpython/issues/109207

   (37) https://github.com/python/cpython/issues/109179

   (38) https://github.com/python/cpython/issues/109118

   (39) https://github.com/python/cpython/issues/109156

   (40) https://github.com/python/cpython/issues/109114

   (41) https://github.com/python/cpython/issues/105848

   (42) https://github.com/python/cpython/issues/109052

   (43) https://github.com/python/cpython/issues/109118

   (44) https://github.com/python/cpython/issues/88943

   (45) https://github.com/python/cpython/issues/108976

   (46) https://github.com/python/cpython/issues/108732

   (47) https://github.com/python/cpython/issues/108959

   (48) https://github.com/python/cpython/issues/104584

   (49) https://github.com/python/cpython/issues/108727

   (50) https://github.com/python/cpython/issues/108520

   (51) https://github.com/python/cpython/issues/108654

   (52) https://github.com/python/cpython/issues/108488

   (53) https://github.com/python/cpython/issues/108716

   (54) https://github.com/python/cpython/issues/108614

   (55) https://github.com/python/cpython/issues/108487

   (56) https://github.com/python/cpython/issues/106176

   (57) https://github.com/python/cpython/issues/105481

   (58) https://github.com/python/cpython/issues/107901

   (59) https://github.com/python/cpython/issues/108113

   (60) https://github.com/python/cpython/issues/107971

   (61) https://github.com/python/cpython/issues/107944

   (62) https://github.com/python/cpython/issues/108390

   (63) https://github.com/python/cpython/issues/108035

   (64) https://github.com/python/cpython/issues/91051

   (65) https://github.com/python/cpython/issues/106581

   (66) https://github.com/python/cpython/issues/107526

   (67) https://github.com/python/cpython/issues/84805

   (68) https://github.com/python/cpython/issues/107758

   (69) https://github.com/python/cpython/issues/107659

   (70) https://github.com/python/cpython/issues/105848

   (71) https://github.com/python/cpython/issues/107674

   (72) https://github.com/python/cpython/issues/107724

   (73) https://github.com/python/cpython/issues/84436

   (74) https://github.com/python/cpython/issues/107596

   (75) https://github.com/python/cpython/issues/107080

   (76) https://github.com/python/cpython/issues/107557

   (77) https://github.com/python/cpython/issues/106608

   (78) https://github.com/python/cpython/issues/100964

   (79) https://github.com/python/cpython/issues/107455

   (80) https://github.com/python/cpython/issues/107263

   (81) https://github.com/python/cpython/issues/104584

   (82) https://github.com/python/cpython/issues/104432

   (83) https://github.com/python/cpython/issues/106078

   (84) https://peps.python.org/pep-0687/

   (85) https://github.com/python/cpython/issues/106898

   (86) https://github.com/python/cpython/issues/106895

   (87) https://github.com/python/cpython/issues/106897

   (88) https://github.com/python/cpython/issues/77377

   (89) https://github.com/python/cpython/issues/106931

   (90) https://github.com/python/cpython/issues/104621

   (91) https://github.com/python/cpython/issues/107122

   (92) https://github.com/python/cpython/issues/107122

   (93) https://github.com/python/cpython/issues/107015

   (94) https://github.com/python/cpython/issues/106917

   (95) https://github.com/python/cpython/issues/105699

   (96) https://github.com/python/cpython/issues/105699

   (97) https://github.com/python/cpython/issues/106908

   (98) https://github.com/python/cpython/issues/106092

   (99) https://github.com/python/cpython/issues/106485

   (100) https://github.com/python/cpython/issues/106719

   (101) https://github.com/python/cpython/issues/106723

   (102) https://github.com/python/cpython/issues/104909

   (103) https://github.com/python/cpython/issues/104909

   (104) https://github.com/python/cpython/issues/106597

   (105) https://github.com/python/cpython/issues/106487

   (106) https://github.com/python/cpython/issues/96844

   (107) https://github.com/python/cpython/issues/81283

   (108) https://github.com/python/cpython/issues/106396

   (109) https://github.com/python/cpython/issues/100288

   (110) https://github.com/python/cpython/issues/106008

   (111) https://github.com/python/cpython/issues/106145

   (112) https://github.com/python/cpython/issues/106213

   (113) https://github.com/python/cpython/issues/106182

   (114) https://github.com/python/cpython/issues/106210

   (115) https://github.com/python/cpython/issues/104584

   (116) https://github.com/python/cpython/issues/105775

   (117) https://github.com/python/cpython/issues/105730

   (118) https://github.com/python/cpython/issues/105979

   (119) https://github.com/python/cpython/issues/106003

   (120) https://github.com/python/cpython/issues/98931

   (121) https://github.com/python/cpython/issues/105724

   (122) https://github.com/python/cpython/issues/105908

   (123) https://github.com/python/cpython/issues/99111

   (124) https://github.com/python/cpython/issues/105840

   (125) https://github.com/python/cpython/issues/105831

   (126) https://github.com/python/cpython/issues/105800

   (127) https://github.com/python/cpython/issues/105340

   (128) https://github.com/python/cpython/issues/105331

   (129) https://github.com/python/cpython/issues/105587

   (130) https://github.com/python/cpython/issues/105564

   (131) https://github.com/python/cpython/issues/105549

   (132) https://github.com/python/cpython/issues/105588

   (133) https://github.com/python/cpython/issues/100987

   (134) https://github.com/python/cpython/issues/105375

   (135) https://github.com/python/cpython/issues/105375

   (136) https://github.com/python/cpython/issues/105375

   (137) https://github.com/python/cpython/issues/105486

   (138) https://github.com/python/cpython/issues/105678

   (139) https://github.com/python/cpython/issues/105435

   (140) https://github.com/python/cpython/issues/105390

   (141) https://github.com/python/cpython/issues/105259

   (142) https://github.com/python/cpython/issues/104635

   (143) https://github.com/python/cpython/issues/105324

   (144) https://github.com/python/cpython/issues/33092

   (145) https://github.com/python/cpython/issues/105229

   (146) https://github.com/python/cpython/issues/105235

   (147) https://github.com/python/cpython/issues/98963

   (148) https://github.com/python/cpython/issues/104812

   (149) https://github.com/python/cpython/issues/105194

   (150) https://github.com/python/cpython/issues/105229

   (151) https://github.com/python/cpython/issues/105162

   (152) https://github.com/python/cpython/issues/105164

   (153) https://github.com/python/cpython/issues/105148

   (154) https://github.com/python/cpython/issues/104799

   (155) https://github.com/python/cpython/issues/105111

   (156) https://github.com/python/cpython/issues/105035

   (157) https://github.com/python/cpython/issues/105017

   (158) https://github.com/python/cpython/issues/105013

   (159) https://github.com/python/cpython/issues/105017

   (160) https://github.com/python/cpython/issues/104976

   (161) https://github.com/python/cpython/issues/104972

   (162) https://github.com/python/cpython/issues/104955

   (163) https://github.com/python/cpython/issues/104690

   (164) https://github.com/python/cpython/issues/104879

   (165) https://github.com/python/cpython/issues/104825

   (166) https://github.com/python/cpython/issues/104770

   (167) https://github.com/python/cpython/issues/89091

   (168) https://github.com/python/cpython/issues/96663

   (169) https://github.com/python/cpython/issues/93627

   (170) https://github.com/python/cpython/issues/101006

   (171) https://github.com/python/cpython/issues/91095


File: python.info,  Node: Library<63>,  Next: Documentation<19>,  Prev: Core and Builtins<58>,  Up: Python 3 13 0 alpha 1

1.24.25.3 Library
.................

   - gh-110786(1): *note sysconfig: e1.’s CLI now ignores *note
     BrokenPipeError: 125e, making it exit normally if its output is
     being piped and the pipe closes.

   - gh-103480(2): The *note sysconfig: e1. module is now a package,
     instead of a single-file module.

   - gh-110733(3): Micro-optimization: Avoid calling ‘min()’, ‘max()’ in
     ‘BaseEventLoop._run_once()’.

   - gh-94597(4): Added *note asyncio.EventLoop: 1a4f. for use with the
     *note asyncio.run(): 2f3. 'loop_factory' kwarg to avoid calling the
     asyncio policy system.

   - gh-110682(5): *note runtime-checkable protocols: 675. used to
     consider ‘__match_args__’ a protocol member in ‘__instancecheck__’
     if it was present on the protocol.  Now, this attribute is ignored
     if it is present.

   - gh-110488(6): Fix a couple of issues in *note
     pathlib.PurePath.with_name(): 1a50.: a single dot was incorrectly
     considered a valid name, and in ‘PureWindowsPath’, a name with an
     NTFS alternate data stream, like ‘a:b’, was incorrectly considered
     invalid.

   - gh-110590(7): Fix a bug in ‘_sre.compile()’ where *note TypeError:
     198. would be overwritten by *note OverflowError: a83. when the
     'code' argument was a list of non-ints.

   - gh-65052(8): Prevent *note pdb: aa. from crashing when trying to
     display undisplayable objects

   - gh-110519(9): Deprecation warning about non-integer number in *note
     gettext: 67. now always refers to the line in the user code where
     gettext function or method is used.  Previously it could refer to a
     line in ‘gettext’ code.

   - gh-89902(10): Deprecate non-standard format specifier «N» for *note
     decimal.Decimal: 1fe.  It was not documented and only supported in
     the C implementation.

   - gh-110378(11): *note contextmanager(): 140a. and *note
     asynccontextmanager(): d21. context managers now close an invalid
     underlying generator object that yields more then one value.

   - gh-106670(12): In *note pdb: aa, set convenience variable
     ‘$_exception’ for post mortem debugging.

   - gh-110365(13): Fix *note termios.tcsetattr(): 1a51. bug that was
     overwriting existing errors during parsing integers from ‘term’
     list.

   - gh-109653(14): Slightly improve the import time of several
     standard-library modules by deferring imports of *note warnings:
     118. within those modules.  Patch by Alex Waygood.

   - gh-110273(15): *note dataclasses.replace(): 1a52. now raises
     TypeError instead of ValueError if specify keyword argument for a
     field declared with init=False or miss keyword argument for
     required InitVar field.

   - gh-110249(16): Add ‘--inline-caches’ flag to ‘dis’ command line.

   - gh-109653(17): Fix a Python 3.12 regression in the import time of
     *note random: bd.  Patch by Alex Waygood.

   - gh-110222(18): Add support of struct sequence objects in *note
     copy.replace(): 1c0.  Patched by Xuehai Pan.

   - gh-109649(19): *note multiprocessing: 98, *note concurrent.futures:
     24, *note compileall: 21.: Replace *note os.cpu_count(): 4dc. with
     *note os.process_cpu_count(): 4db. to select the default number of
     worker threads and processes.  Get the CPU affinity if supported.
     Patch by Victor Stinner.

   - gh-110150(20): Fix base case handling in statistics.quantiles.  Now
     allows a single data point.

   - gh-110036(21): On Windows, multiprocessing ‘Popen.terminate()’ now
     catches *note PermissionError: f40. and get the process exit code.
     If the process is still running, raise again the *note
     PermissionError: f40.  Otherwise, the process terminated as
     expected: store its exit code.  Patch by Victor Stinner.

   - gh-110038(22): Fixed an issue that caused ‘KqueueSelector.select()’
     to not return all the ready events in some cases when a file
     descriptor is registered for both read and write.

   - gh-110045(23): Update the *note symtable: de. module to support the
     new scopes introduced by PEP 695(24).

   - gh-88402(25): Add new variables to *note
     sysconfig.get_config_vars(): 298. on Windows: ‘LIBRARY’,
     ‘LDLIBRARY’, ‘LIBDIR’, ‘SOABI’, and ‘Py_NOGIL’.

   - gh-109631(26): *note re: be. functions such as *note re.findall():
     122c, *note re.split(): 5a2, *note re.search(): 1434. and *note
     re.sub(): 5a3. which perform short repeated matches can now be
     interrupted by user.

   - gh-109653(27): Reduce the import time of *note email.utils: 54. by
     around 43%.  This results in the import time of *note
     email.message: 48. falling by around 18%, which in turn reduces the
     import time of *note importlib.metadata: 7e. by around 6%.  Patch
     by Alex Waygood.

   - gh-109818(28): Fix *note reprlib.recursive_repr(): 13fb. not
     copying ‘__type_params__’ from decorated function.

   - gh-109047(29): *note concurrent.futures: 24.: The 'executor manager
     thread' now catches exceptions when adding an item to the 'call
     queue'.  During Python finalization, creating a new thread can now
     raise *note RuntimeError: 244.  Catch the exception and call
     ‘terminate_broken()’ in this case.  Patch by Victor Stinner.

   - gh-109782(30): Ensure the signature of *note os.path.isdir(): c07.
     is identical on all platforms.  Patch by Amin Alaee.

   - gh-109653(31): Improve import time of *note functools: 63. by
     around 13%.  Patch by Alex Waygood.

   - gh-109590(32): *note shutil.which(): 6dc. will prefer files with an
     extension in ‘PATHEXT’ if the given mode includes ‘os.X_OK’ on
     win32.  If no ‘PATHEXT’ match is found, a file without an extension
     in ‘PATHEXT’ can be returned.  This change will have *note
     shutil.which(): 6dc. act more similarly to previous behavior in
     Python 3.11.

   - gh-109653(33): Reduce the import time of *note enum: 5a. by over
     50%.  Patch by Alex Waygood.

   - gh-109593(34): Avoid deadlocking on a reentrant call to the
     multiprocessing resource tracker.  Such a reentrant call, though
     unlikely, can happen if a GC pass invokes the finalizer for a
     multiprocessing object such as SemLock.

   - gh-109653(35): Reduce the import time of *note typing: 10a. by
     around a third.  Patch by Alex Waygood.

   - gh-109649(36): Add *note os.process_cpu_count(): 4db. function to
     get the number of logical CPUs usable by the calling thread of the
     current process.  Patch by Victor Stinner.

   - gh-74481(37): Add ‘set_error_mode’ related constants in ‘msvcrt’
     module in Python debug build.

   - gh-109613(38): Fix *note os.stat(): 26d. and *note
     os.DirEntry.stat(): 1a53.: check for exceptions.  Previously, on
     Python built in debug mode, these functions could trigger a fatal
     Python error (and abort the process) when a function succeeded with
     an exception set.  Patch by Victor Stinner.

   - gh-109599(39): Expose the type of PyCapsule objects as
     ‘types.CapsuleType’.

   - gh-109109(40): You can now get the raw TLS certificate chains from
     TLS connections via *note ssl.SSLSocket.get_verified_chain(): 1944.
     and *note ssl.SSLSocket.get_unverified_chain(): 1945. methods.

     Contributed by Mateusz Nowak.

   - gh-109559(41): Update *note unicodedata: 10b. database to Unicode
     15.1.0.

   - gh-109543(42): Remove unnecessary *note hasattr(): 6fa. check
     during *note typing.TypedDict: 332. creation.

   - gh-109495(43): Remove unnecessary extra ‘__slots__’ in *note
     datetime: 4e3.'s pure python implementation to reduce memory size,
     as they are defined in the superclass.  Patch by James Hilton-Balfe

   - gh-109461(44): *note logging: 8b.: Use a context manager for lock
     acquisition.

   - gh-109096(45): *note http.server.CGIHTTPRequestHandler: 325. has
     been deprecated for removal in 3.15.  Its design is old and the web
     world has long since moved beyond CGI.

   - gh-109409(46): Fix error when it was possible to inherit a frozen
     dataclass from multiple parents some of which were possibly not
     frozen.

   - gh-109375(47): The *note pdb: aa. ‘alias’ command now prevents
     registering aliases without arguments.

   - gh-109319(48): Deprecate the ‘dis.HAVE_ARGUMENT’ field in favour of
     ‘dis.hasarg’.

   - gh-107219(49): Fix a race condition in ‘concurrent.futures’.  When
     a process in the process pool was terminated abruptly (while the
     future was running or pending), close the connection write end.  If
     the call queue is blocked on sending bytes to a worker process,
     closing the connection write end interrupts the send, so the queue
     can be closed.  Patch by Victor Stinner.

   - gh-66143(50): The *note codecs.CodecInfo: 1a54. object has been
     made copyable and pickleable.  Patched by Robert Lehmann and Furkan
     Onder.

   - gh-109187(51): *note pathlib.Path.resolve(): 1a55. now treats
     symlink loops like other errors: in strict mode, *note OSError:
     2c0. is raised, and in non-strict mode, no exception is raised.

   - gh-50644(52): Attempts to pickle or create a shallow or deep copy
     of *note codecs: 1c. streams now raise a TypeError.  Previously,
     copying failed with a RecursionError, while pickling produced wrong
     results that eventually caused unpickling to fail with a
     RecursionError.

   - gh-109174(53): Add support of *note types.SimpleNamespace: 4e6. in
     *note copy.replace(): 1c0.

   - gh-109164(54): *note pdb: aa.: Replace *note getopt: 65. with *note
     argparse: 7. for parsing command line arguments.

   - gh-109151(55): Enable ‘readline’ editing features in the *note
     sqlite3 command-line interface: 674. (‘python -m sqlite3’).

   - gh-108987(56): Fix *note _thread.start_new_thread(): 4b5. race
     condition.  If a thread is created during Python finalization, the
     newly spawned thread now exits immediately instead of trying to
     access freed memory and lead to a crash.  Patch by Victor Stinner.

   - gh-108682(57): Enum: require ‘names=()’ or ‘type=...’ to create an
     empty enum using the functional syntax.

   - gh-109033(58): Exceptions raised by os.utime builtin function now
     include the related filename

   - gh-108843(59): Fix an issue in *note ast.unparse(): ae4. when
     unparsing f-strings containing many quote types.

   - gh-108469(60): *note ast.unparse(): ae4. now supports new *note
     f-string: 66b. syntax introduced in Python 3.12.  Note that the
     *note f-string: 66b. quotes are reselected for simplicity under the
     new syntax.  (Patch by Steven Sun)

   - gh-108751(61): Add *note copy.replace(): 1c0. function which allows
     to create a modified copy of an object.  It supports named tuples,
     dataclasses, and many other objects.

   - gh-108682(62): Enum: raise *note TypeError: 198. if
     ‘super().__new__()’ is called from a custom ‘__new__’.

   - gh-108278(63): Deprecate passing the callback callable by keyword
     for the following *note sqlite3.Connection: 54e. APIs:

        * *note set_authorizer(): 5a9.

        * *note set_progress_handler(): 5aa.

        * *note set_trace_callback(): 5ab.

     The affected parameters will become positional-only in Python 3.15.

     Patch by Erlend E. Aasland.

   - gh-105829(64): Fix concurrent.futures.ProcessPoolExecutor deadlock

   - gh-108295(65): Fix crashes related to use of weakrefs on *note
     typing.TypeVar: 487.

   - gh-108463(66): Make expressions/statements work as expected in pdb

   - gh-108277(67): Add *note os.timerfd_create(): 520, *note
     os.timerfd_settime(): 521, *note os.timerfd_gettime(): 523, *note
     os.timerfd_settime_ns(): 522, and *note os.timerfd_gettime_ns():
     524. to provide a low level interface for Linux’s timer
     notification file descriptor.

   - gh-107811(68): *note tarfile: e4.: extraction of members with
     overly large UID or GID (e.g.  on an OS with 32-bit ‘id_t’) now
     fails in the same way as failing to set the ID.

   - gh-64662(69): Fix support for virtual tables in *note
     sqlite3.Connection.iterdump(): 550.  Patch by Aviv Palivoda.

   - gh-108111(70): Fix a regression introduced in gh-101251(71) for
     3.12, resulting in an incorrect offset calculation in
     ‘gzip.GzipFile.seek()’.

   - gh-108294(72): *note time.sleep(): 8ad. now raises an auditing
     event.

   - gh-108278(73): Deprecate passing name, number of arguments, and the
     callable as keyword arguments, for the following *note
     sqlite3.Connection: 54e. APIs:

        * *note create_function(): 5a7.

        * *note create_aggregate(): 5a8.

     The affected parameters will become positional-only in Python 3.15.

     Patch by Erlend E. Aasland.

   - gh-108322(74): Speed-up NormalDist.samples() by using the inverse
     CDF method instead of calling random.gauss().

   - gh-83417(75): Add the ability for venv to create a ‘.gitignore’
     file which causes the created environment to be ignored by Git.  It
     is on by default when venv is called via its CLI.

   - gh-105736(76): Harmonized the pure Python version of *note
     OrderedDict: 7f4. with the C version.  Now, both versions set up
     their internal state in ‘__new__’.  Formerly, the pure Python
     version did the set up in ‘__init__’.

   - gh-108083(77): Fix bugs in the constructor of *note
     sqlite3.Connection: 54e. and *note sqlite3.Connection.close(): 54f.
     where exceptions could be leaked.  Patch by Erlend E. Aasland.

   - gh-107932(78): Fix ‘dis’ module to properly report and display
     bytecode that do not have source lines.

   - gh-105539(79): *note sqlite3: d4. now emits an *note
     ResourceWarning: 54d. if a *note sqlite3.Connection: 54e. object is
     not ‘closed’ explicitly.  Patch by Erlend E. Aasland.

   - gh-107995(80): The ‘__module__’ attribute on instances of *note
     functools.cached_property: 764. is now set to the name of the
     module in which the cached_property is defined, rather than
     «functools».  This means that doctests in ‘cached_property’
     docstrings are now properly collected by the *note doctest: 3e.
     module.  Patch by Tyler Smart.

   - gh-107963(81): Fix *note multiprocessing.set_forkserver_preload():
     18f0. to check the given list of modules names.  Patch by Donghee
     Na.

   - gh-106242(82): Fixes *note os.path.normpath(): 1521. to handle
     embedded null characters without truncating the path.

   - gh-81555(83): *note xml.dom.minidom: 128. now only quotes ‘"’ in
     attributes.

   - gh-50002(84): *note xml.dom.minidom: 128. now preserves whitespaces
     in attributes.

   - gh-93057(85): Passing more than one positional argument to *note
     sqlite3.connect(): 5a6. and the *note sqlite3.Connection: 54e.
     constructor is deprecated.  The remaining parameters will become
     keyword-only in Python 3.15.  Patch by Erlend E. Aasland.

   - gh-76913(86): Add 'merge_extra' parameter/feature to *note
     logging.LoggerAdapter: 14fd.

   - gh-107913(87): Fix possible losses of ‘errno’ and ‘winerror’ values
     in *note OSError: 2c0. exceptions if they were cleared or modified
     by the cleanup code before creating the exception object.

   - gh-107845(88): *note tarfile.data_filter(): 29a. now takes the
     location of symlinks into account when determining their target, so
     it will no longer reject some valid tarballs with
     ‘LinkOutsideDestinationError’.

   - gh-107812(89): Extend socket’s netlink support to the FreeBSD
     platform.

   - gh-107805(90): Fix signatures of module-level generated functions
     in *note turtle: 107.

   - gh-107782(91): *note pydoc: ba. is now able to show signatures
     which are not representable in Python, e.g.  for ‘getattr’ and
     ‘dict.pop’.

   - gh-56166(92): Deprecate passing optional arguments 'maxsplit',
     'count' and 'flags' in module-level functions *note re.split():
     5a2, *note re.sub(): 5a3. and *note re.subn(): 5a4. as positional.
     They should only be passed by keyword.

   - gh-107710(93): Speed up *note logging.getHandlerNames(): 1a56.

   - gh-107715(94): Fix *note doctest.DocTestFinder.find(): 1a57. in
     presence of class names with special characters.  Patch by Gertjan
     van Zwieten.

   - gh-100814(95): Passing a callable object as an option value to a
     Tkinter image now raises the expected TclError instead of an
     AttributeError.

   - gh-72684(96): Add *note tkinter: f6. widget methods:
     ‘tk_busy_hold()’, ‘tk_busy_configure()’, ‘tk_busy_cget()’,
     ‘tk_busy_forget()’, ‘tk_busy_current()’, and ‘tk_busy_status()’.

   - gh-106684(97): Raise *note ResourceWarning: 54d. when *note
     asyncio.StreamWriter: 1a58. is not closed leading to memory leaks.
     Patch by Kumar Aditya.

   - gh-107465(98): Add *note pathlib.Path.from_uri(): 535. classmethod.

   - gh-107077(99): Seems that in some conditions, OpenSSL will return
     ‘SSL_ERROR_SYSCALL’ instead of ‘SSL_ERROR_SSL’ when a certification
     verification has failed, but the error parameters will still
     contain ‘ERR_LIB_SSL’ and ‘SSL_R_CERTIFICATE_VERIFY_FAILED’.  We
     are now detecting this situation and raising the appropriate
     ‘ssl.SSLCertVerificationError’.  Patch by Pablo Galindo

   - gh-107576(100): Fix *note types.get_original_bases(): 6f6. to only
     return ‘__orig_bases__’ if it is present on ‘cls’ directly.  Patch
     by James Hilton-Balfe.

   - gh-105481(101): Remove ‘opcode.is_pseudo’,
     ‘opcode.MIN_PSEUDO_OPCODE’ and ‘opcode.MAX_PSEUDO_OPCODE’, which
     were added in 3.12, were never documented and were not intended to
     be used externally.

   - gh-105481(102): ‘opcode.ENABLE_SPECIALIZATION’ (which was added in
     3.12 but never documented or intended for external usage) is moved
     to ‘_opcode.ENABLE_SPECIALIZATION’ where tests can access it.

   - gh-107396(103): tarfiles; Fixed use before assignment of
     self.exception for gzip decompression

   - gh-107409(104): Set ‘__wrapped__’ attribute in *note
     reprlib.recursive_repr(): 13fb.

   - gh-107406(105): Implement new ‘__repr__()’ method for *note
     struct.Struct: 175f.  Now it returns ‘Struct(<format repr>)’.

   - gh-107369(106): Optimize *note textwrap.indent(): 57d.  It is ~30%
     faster for large input.  Patch by Inada Naoki.

   - gh-78722(107): Fix issue where *note pathlib.Path.iterdir(): 26e.
     did not raise *note OSError: 2c0. until iterated.

   - gh-105578(108): Deprecate *note typing.AnyStr: 5ac. in favor of the
     new Type Parameter syntax.  See PEP 695.

   - gh-62519(109): Make *note gettext.pgettext(): bea. search plural
     definitions when translation is not found.

   - gh-107089(110): Shelves opened with *note shelve.open(): 1a59. have
     a much faster ‘clear()’ method.  Patch by James Cave.

   - gh-82500(111): Fix overflow on 32-bit systems with *note asyncio:
     b. *note os.sendfile(): d07. implementation.

   - gh-83006(112): Document behavior of *note shutil.disk_usage():
     1335. for non-mounted filesystems on Unix.

   - gh-65495(113): Use lowercase ‘mail from’ and ‘rcpt to’ in
     ‘smptlib.SMTP’.

   - gh-106186(114): Do not report ‘MultipartInvariantViolationDefect’
     defect when the *note email.parser.Parser: 13a5. class is used to
     parse emails with ‘headersonly=True’.

   - gh-105002(115): Fix invalid result from ‘PurePath.relative_to()’
     method when attempting to walk a «‘..’» segment in 'other' with
     'walk_up' enabled.  A *note ValueError: 2ec. exception is now
     raised in this case.

   - gh-106739(116): Add the ‘rtype_cache’ to the warning message (as an
     addition to the type of leaked objects and the number of leaked
     objects already included in the message) to make debugging leaked
     objects easier when the multiprocessing resource tracker process
     finds leaked objects at shutdown.  This helps more quickly identify
     what was leaked and/or why the leaked object was not properly
     cleaned up.

   - gh-106751(117): Optimize ‘SelectSelector.select()’ for many
     iteration case.  Patch By Donghee Na.

   - gh-106751(118): Optimize ‘_PollLikeSelector.select()’ for many
     iteration case.

   - gh-106751(119): Optimize ‘KqueueSelector.select()’ for many
     iteration case.  Patch By Donghee Na.

   - gh-106831(120): Fix potential missing ‘NULL’ check of
     ‘d2i_SSL_SESSION’ result in ‘_ssl.c’.

   - gh-105481(121): The various opcode lists in the *note dis: 3c.
     module are now generated from bytecodes.c instead of explicitly
     constructed in opcode.py.

   - gh-106727(122): Make *note inspect.getsource(): 17ab. smarter for
     class for same name definitions

   - gh-106789(123): Remove import of *note pprint: b3. from *note
     sysconfig: e1.

   - gh-105726(124): Added ‘__slots__’ to *note
     contextlib.AbstractContextManager: e8c. and *note
     contextlib.AbstractAsyncContextManager: d22. so that child classes
     can use ‘__slots__’.

   - gh-106774(125): Update the bundled copy of pip to version 23.2.1.

   - gh-106751(126): *note selectors: c7.: Optimize
     ‘EpollSelector.select()’ code by moving some code outside of the
     loop.

   - gh-106752(127): Fixed several bugs in zipfile.Path, including: in
     ‘zipfile.Path.match()’, Windows separators are no longer honored
     (and never were meant to be); Fixed
     ‘name’/‘suffix’/‘suffixes’/‘stem’ operations when no filename is
     present and the Path is not at the root of the zipfile; Reworked
     glob for performance and more correct matching behavior.

   - gh-105293(128): Remove call to ‘SSL_CTX_set_session_id_context’
     during client side context creation in the *note ssl: d5. module.

   - gh-106734(129): Disable tab completion in multiline mode of *note
     pdb: aa.

   - gh-105481(130): Expose opcode metadata through ‘_opcode’.

   - gh-106670(131): Add the new ‘exceptions’ command to the Pdb
     debugger.  It makes it possible to move between chained exceptions
     when using post mortem debugging.

   - gh-106602(132): Add __copy__ and __deepcopy__ in *note enum: 5a.

   - gh-106664(133): *note selectors: c7.: Add ‘_SelectorMapping.get()’
     method and optimize ‘_SelectorMapping.__getitem__()’.

   - gh-106628(134): Speed up parsing of emails by about 20% by not
     compiling a new regular expression for every single email.

   - gh-89427(135): Set the environment variable ‘VIRTUAL_ENV_PROMPT’ at
     *note venv: 117. activation, even when ‘VIRTUAL_ENV_DISABLE_PROMPT’
     is set.

   - gh-106530(136): Revert a change to *note colorsys.rgb_to_hls():
     1a5a. that caused division by zero for certain almost-white inputs.
     Patch by Terry Jan Reedy.

   - gh-106584(137): Fix exit code for ‘unittest’ if all tests are
     skipped.  Patch by Egor Eliseev.

   - gh-106566(138): Optimize ‘(?!)’ (pattern which always fails) in
     regular expressions.

   - gh-106554(139): *note selectors: c7.: Reduce Selector overhead by
     using a ‘dict.get()’ to lookup file descriptors.

   - gh-106558(140): Remove ref cycle in callers of ‘convert_to_error()’
     by deleting ‘result’ from scope in a ‘finally’ block.

   - gh-100502(141): Add ‘pathlib.PurePath.pathmod’ class attribute that
     stores the implementation of *note os.path: a6. used for low-level
     path operations: either ‘posixpath’ or ‘ntpath’.

   - gh-106527(142): Reduce overhead to add and remove *note asyncio: b.
     readers and writers.

   - gh-106524(143): Fix crash in ‘_sre.template()’ with templates
     containing invalid group indices.

   - gh-106531(144): Removed ‘_legacy’ and the names it provided from
     ‘importlib.resources’: ‘Resource’, ‘contents’, ‘is_resource’,
     ‘open_binary’, ‘open_text’, ‘path’, ‘read_binary’, and ‘read_text’.

   - gh-106052(145): *note re: be. module: fix the matching of
     possessive quantifiers in the case of a subpattern containing
     backtracking.

   - gh-106510(146): Improve debug output for atomic groups in regular
     expressions.

   - gh-106503(147): Fix ref cycle in ‘asyncio._SelectorSocketTransport’
     by removing ‘_write_ready’ in ‘close’.

   - gh-105497(148): Fix flag mask inversion when unnamed flags exist.

   - gh-90876(149): Prevent ‘multiprocessing.spawn’ from failing to
     'import' in environments where ‘sys.executable’ is ‘None’.  This
     regressed in 3.11 with the addition of support for path-like
     objects in multiprocessing.

   - gh-106403(150): Instances of *note typing.TypeVar: 487, *note
     typing.ParamSpec: 488, *note typing.ParamSpecArgs: 9cb, *note
     typing.ParamSpecKwargs: 9cc, and *note typing.TypeVarTuple: 489.
     once again support weak references, fixing a regression introduced
     in Python 3.12.0 beta 1.  Patch by Jelle Zijlstra.

   - gh-89812(151): Add private ‘pathlib._PathBase’ class, which
     provides experimental support for virtual filesystems, and may be
     made public in a future version of Python.

   - gh-106292(152): Check for an instance-dict cached value in the
     ‘__get__()’ method of *note functools.cached_property(): 764.  This
     better matches the pre-3.12 behavior and improves compatibility for
     users subclassing *note functools.cached_property(): 764. and
     adding a ‘__set__()’ method.

   - gh-106350(153): Detect possible memory allocation failure in the
     libtommath function ‘mp_init()’ used by the ‘_tkinter’ module.

   - gh-106330(154): Fix incorrect matching of empty paths in *note
     pathlib.PurePath.match(): 6d4.  This bug was introduced in Python
     3.12.0 beta 1.

   - gh-106309(155): Deprecate *note typing.no_type_check_decorator():
     333.  No major type checker ever added support for this decorator.
     Patch by Alex Waygood.

   - gh-102541(156): Make ‘pydoc.doc()’ catch bad module *note
     ImportError: 65b. when output stream is not ‘None’.

   - gh-106263(157): Fix crash when calling ‘repr’ with a manually
     constructed SignalDict object.  Patch by Charlie Zhao.

   - gh-106236(158): Replace ‘assert’ statements with ‘raise
     RuntimeError’ in *note threading: f3, so that ‘_DummyThread’ cannot
     be joined even with ‘-OO’.

   - gh-106238(159): Fix rare concurrency bug in lock acquisition by the
     logging package.

   - gh-106152(160): Added PY_THROW event hook for *note cProfile: 2b.
     for generators

   - gh-106075(161): Added ‘asyncio.taskgroups.__all__’ to
     ‘asyncio.__all__’ for export in star imports.

   - gh-104527(162): Zipapp will now skip over appending an archive to
     itself.

   - gh-106046(163): Improve the error message from *note os.fspath():
     e4f. if called on an object where ‘__fspath__’ is set to ‘None’.
     Patch by Alex Waygood.

   - gh-105987(164): Fix crash due to improper reference counting in
     *note asyncio: b. eager task factory internal routines.

   - gh-105974(165): Fix bug where a *note typing.Protocol: 56b. class
     that had one or more non-callable members would raise *note
     TypeError: 198. when *note issubclass(): 9c6. was called against
     it, even if it defined a custom ‘__subclasshook__’ method.  The
     behaviour in Python 3.11 and lower – which has now been restored –
     was not to raise *note TypeError: 198. in these situations if a
     custom ‘__subclasshook__’ method was defined.  Patch by Alex
     Waygood.

   - gh-96145(166): Reverted addition of ‘json.AttrDict’.

   - gh-89812(167): Add *note pathlib.UnsupportedOperation: 534, which
     is raised instead of *note NotImplementedError: 36b. when a path
     operation isn’t supported.

   - gh-105808(168): Fix a regression introduced in gh-101251(169) for
     3.12, causing ‘gzip.GzipFile.flush()’ to not flush the compressor
     (nor pass along the ‘zip_mode’ argument).

   - gh-105481(170): *note stack_effect(): 1133. no longer raises an
     exception if an ‘oparg’ is provided for an ‘opcode’ that doesn’t
     use its arg, or when it is not provided for an ‘opcode’ that does
     use it.  In the latter case, the stack effect is returned for
     ‘oparg=0’.

   - gh-104799(171): Enable *note ast.unparse(): ae4. to unparse
     function and class definitions created without the new
     ‘type_params’ field from PEP 695(172).  Patch by Jelle Zijlstra.

   - gh-105793(173): Add 'follow_symlinks' keyword-only argument to
     *note pathlib.Path.is_dir(): 53b. and *note is_file(): 53a,
     defaulting to ‘True’.

   - gh-105570(174): Deprecate two methods of creating *note
     typing.TypedDict: 332. classes with 0 fields using the functional
     syntax: ‘TD = TypedDict("TD")’ and ‘TD = TypedDict("TD", None)’.
     Both will be disallowed in Python 3.15.  To create a ‘TypedDict’
     class with 0 fields, either use ‘class TD(TypedDict): pass’ or ‘TD
     = TypedDict("TD", {})’.

   - gh-105745(175): Fix ‘webbrowser.Konqueror.open’ method.

   - gh-105733(176): *note ctypes: 2e.: Deprecate undocumented
     ‘ctypes.SetPointerType()’ and ‘ctypes.ARRAY()’ functions.  Patch by
     Victor Stinner.

   - gh-105687(177): Remove deprecated ‘re.template’, ‘re.T’,
     ‘re.TEMPLATE’, ‘sre_constans.SRE_FLAG_TEMPLATE’.

   - gh-105684(178): Supporting *note asyncio.Task.set_name(): bd2. is
     now mandatory for third party task implementations.  The
     undocumented ‘_set_task_name()’ function (deprecated since 3.8) has
     been removed.  Patch by Kumar Aditya.

   - gh-105375(179): Fix a bug in ‘_Unpickler_SetInputStream()’ where an
     exception could end up being overwritten in case of failure.

   - gh-105626(180): Change the default return value of *note
     http.client.HTTPConnection.get_proxy_response_headers(): 1a5b. to
     be ‘None’ and not ‘{}’.

   - gh-105375(181): Fix bugs in *note sys: df. where exceptions could
     end up being overwritten because of deferred error handling.

   - gh-105605(182): Harden ‘pyexpat’ error handling during module
     initialisation to prevent exceptions from possibly being
     overwritten, and objects from being dereferenced twice.

   - gh-105375(183): Fix bug in *note decimal: 3a. where an exception
     could end up being overwritten.

   - gh-105375(184): Fix bugs in ‘_datetime’ where exceptions could be
     overwritten in case of module initialisation failure.

   - gh-105375(185): Fix bugs in ‘_ssl’ initialisation which could lead
     to leaked references and overwritten exceptions.

   - gh-105375(186): Fix a bug in *note array.array: 4bf. where an
     exception could end up being overwritten.

   - gh-105375(187): Fix bugs in ‘_ctypes’ where exceptions could end up
     being overwritten.

   - gh-105375(188): Fix a bug in the *note posix: b2. module where an
     exception could be overwritten.

   - gh-105375(189): Fix bugs in ‘_elementtree’ where exceptions could
     be overwritten.

   - gh-105375(190): Fix bugs in *note zoneinfo: 13a. where exceptions
     could be overwritten.

   - gh-105375(191): Fix bugs in *note errno: 5b. where exceptions could
     be overwritten.

   - gh-105566(192): Deprecate creating a *note typing.NamedTuple: 331.
     class using keyword arguments to denote the fields (‘NT =
     NamedTuple("NT", x=int, y=str)’).  This will be disallowed in
     Python 3.15.  Use the class-based syntax or the functional syntax
     instead.

     Two methods of creating ‘NamedTuple’ classes with 0 fields using
     the functional syntax are also deprecated, and will be disallowed
     in Python 3.15: ‘NT = NamedTuple("NT")’ and ‘NT = NamedTuple("NT",
     None)’.  To create a ‘NamedTuple’ class with 0 fields, either use
     ‘class NT(NamedTuple): pass’ or ‘NT = NamedTuple("NT", [])’.

   - gh-105545(193): Remove deprecated in 3.11
     ‘webbrowser.MacOSXOSAScript._name’ attribute.

   - gh-105497(194): Fix flag inversion when alias/mask members exist.

   - gh-105509(195): *note typing.Annotated: b39. is now implemented as
     an instance of ‘typing._SpecialForm’ rather than a class.  This
     should have no user-facing impact for users of the *note typing:
     10a. module public API.

   - gh-105375(196): Fix bugs in *note pickle: ab. where exceptions
     could be overwritten.

   - gh-70303(197): Emit *note FutureWarning: 659. from *note
     pathlib.Path.glob(): 538. and *note rglob(): 539. if the given
     pattern ends with «‘**’».  In a future Python release, patterns
     with this ending will match both files and directories.  Add a
     trailing slash to only match directories.

   - gh-105375(198): Fix a bug in *note sqlite3: d4. where an exception
     could be overwritten in the *note collation: 887. callback.

   - gh-105382(199): Remove 'cafile', 'capath' and 'cadefault'
     parameters of the *note urllib.request.urlopen(): 307. function,
     deprecated in Python 3.6.  Patch by Victor Stinner.

   - gh-105376(200): *note logging: 8b.: Remove undocumented and
     untested ‘Logger.warn()’ and ‘LoggerAdapter.warn()’ methods and
     ‘logging.warn()’ function.  Deprecated since Python 3.3, they were
     aliases to the *note logging.Logger.warning(): 1a5c. method,
     ‘logging.LoggerAdapter.warning()’ method and *note
     logging.warning(): 354. function.  Patch by Victor Stinner.

   - gh-105332(201): Revert pickling method from by-name back to
     by-value.

   - gh-104554(202): Add RTSPS scheme support in urllib.parse

   - gh-105292(203): Add option to *note
     traceback.format_exception_only(): a50. to recurse into the nested
     exception of a *note BaseExceptionGroup: 566.

   - gh-105280(204): Fix bug where ‘isinstance([],
     collections.abc.Mapping)’ could evaluate to ‘True’ if garbage
     collection happened at the wrong time.  The bug was caused by
     changes to the implementation of *note typing.Protocol: 56b. in
     Python 3.12.

   - gh-80480(205): *note array: 8.: Add ‘'w'’ typecode that represents
     ‘Py_UCS4’.

   - gh-105239(206): Fix longstanding bug where ‘issubclass(object,
     typing.Protocol)’ would evaluate to ‘True’ in some edge cases.
     Patch by Alex Waygood.

   - gh-104310(207): In the beta 1 release we added a utility function
     for extension module authors, to use when testing their module for
     support in multiple interpreters or under a per-interpreter GIL.
     The name of that function has changed from
     ‘allowing_all_extensions’ to
     ‘_incompatible_extension_module_restrictions’.  The default for the
     «disable_check» argument has change from ‘True’ to ‘False’, to
     better match the new function name.

   - gh-105080(208): Fixed inconsistent signature on derived classes for
     *note inspect.signature(): 22f.

   - gh-105144(209): Fix a recent regression in the *note typing: 10a.
     module.  The regression meant that doing ‘class Foo(X,
     typing.Protocol)’, where ‘X’ was a class that had *note
     abc.ABCMeta: 111d. as its metaclass, would then cause subsequent
     ‘isinstance(1, X)’ calls to erroneously raise *note TypeError: 198.
     Patch by Alex Waygood.

   - gh-62948(210): The *note io.IOBase: 506. finalizer now logs the
     ‘close()’ method errors with *note sys.unraisablehook: 508.
     Previously, errors were ignored silently by default, and only
     logged in *note Python Development Mode: 509. or on *note Python
     built on debug mode: 50a.  Patch by Victor Stinner.

   - gh-105096(211): *note wave: 119.: Deprecate the ‘getmark()’,
     ‘setmark()’ and ‘getmarkers()’ methods of the *note wave.Wave_read:
     336. and *note wave.Wave_write: 337. classes.  They will be removed
     in Python 3.15.  Patch by Victor Stinner.

   - gh-104992(212): Remove the untested and undocumented
     ‘unittest.TestProgram.usageExit()’ method, deprecated in Python
     3.11.  Patch by Hugo van Kemenade.

   - gh-104996(213): Improve performance of *note pathlib.PurePath: 6ce.
     initialisation by deferring joining of paths when multiple
     arguments are given.

   - gh-101588(214): Deprecate undocumented copy/deepcopy/pickle support
     for itertools.

   - gh-103631(215): Fix
     ‘pathlib.PurePosixPath(pathlib.PureWindowsPath(...))’ not
     converting path separators to restore 3.11 compatible behavior.

   - gh-104947(216): Make comparisons between *note
     pathlib.PureWindowsPath: 1a5d. objects consistent across Windows
     and Posix to match 3.11 behavior.

   - gh-104773(217): PEP 594(218): Remove the ‘audioop’ module,
     deprecated in Python 3.11.  Patch by Victor Stinner.

   - gh-104773(219): PEP 594(220): Remove the ‘aifc’ module, deprecated
     in Python 3.11.  Patch by Victor Stinner.

   - gh-104773(221): PEP 594(222): Remove the ‘uu’ module, deprecated in
     Python 3.11.  Patch by Victor Stinner.

   - gh-104935(223): Fix bugs with the interaction between *note
     typing.runtime_checkable(): 675. and *note typing.Generic: 179e.
     that were introduced by the PEP 695(224) implementation.  Patch by
     Jelle Zijlstra.

   - gh-104773(225): PEP 594(226): Remove the ‘crypt’ module and its
     private ‘_crypt’ extension, deprecated in Python 3.11.  Patch by
     Victor Stinner.

   - gh-104773(227): PEP 594(228): Remove the ‘nis’ module, deprecated
     in Python 3.11.  Patch by Victor Stinner.

   - gh-104898(229): Add missing *note __slots__: 16f2. to *note
     os.PathLike: e4d.

   - gh-104773(230): PEP 594(231): Remove the ‘xdrlib’ module,
     deprecated in Python 3.11.  Patch by Victor Stinner.

   - gh-104773(232): PEP 594(233): Remove the ‘nntplib’ module,
     deprecated in Python 3.11.  Patch by Victor Stinner.

   - gh-104886(234): Remove the undocumented
     ‘configparser.LegacyInterpolation’ class, deprecated in the
     docstring since Python 3.2, and with a deprecation warning since
     Python 3.11.  Patch by Hugo van Kemenade.

   - gh-104786(235): Remove kwargs-based *note typing.TypedDict: 332.
     creation

   - gh-104876(236): Remove the ‘turtle.RawTurtle.settiltangle()’
     method, deprecated in docs since Python 3.1 and with a deprecation
     warning since Python 3.11.  Patch by Hugo van Kemenade.

   - gh-104773(237): PEP 594(238): Removed the ‘msilib’ package,
     deprecated in Python 3.11.

   - gh-104773(239): PEP 594(240): Remove the ‘spwd’ module, deprecated
     in Python 3.11: the python-pam(241) project can be used instead.
     Patch by Victor Stinner.

   - gh-75552(242): Removed the ‘tkinter.tix’ module, deprecated since
     Python 3.6.

   - gh-104773(243): PEP 594(244): Remove the ‘chunk’ module, deprecated
     in Python 3.11.  Patch by Victor Stinner.

   - gh-104773(245): PEP 594(246): Remove the ‘mailcap’ module,
     deprecated in Python 3.11.  Patch by Victor Stinner.

   - gh-104773(247): PEP 594(248): Remove the ‘sunau’ module, deprecated
     in Python 3.11.  Patch by Victor Stinner.

   - gh-104780(249): PEP 594(250): Remove the ‘ossaudiodev’ module,
     deprecated in Python 3.11.  Patch Victor Stinner.

   - gh-104773(251): PEP 594(252): Remove the ‘pipes’ module, deprecated
     in Python 3.11.  Patch by Victor Stinner.

   - gh-104873(253): Add *note typing.get_protocol_members(): 56a. to
     return the set of members defining a *note typing.Protocol: 56b.
     Add *note typing.is_protocol(): 56c. to check whether a class is a
     *note typing.Protocol: 56b.  Patch by Jelle Zijlstra.

   - gh-104874(254): Document the ‘__name__’ and ‘__supertype__’
     attributes of *note typing.NewType: ef3.  Patch by Jelle Zijlstra.

   - gh-104835(255): Removed the following *note unittest: 10c.
     functions, deprecated in Python 3.11:

        * ‘unittest.findTestCases()’

        * ‘unittest.makeSuite()’

        * ‘unittest.getTestCaseNames()’

     Use *note TestLoader: 593. methods instead:

        * *note unittest.TestLoader.loadTestsFromModule(): 594.

        * *note unittest.TestLoader.loadTestsFromTestCase(): 595.

        * *note unittest.TestLoader.getTestCaseNames(): 596.

     Patch by Hugo van Kemenade.

   - gh-104804(256): Remove the untested and undocumented *note
     webbrowser: 11b. ‘MacOSX’ class, deprecated in Python 3.11.  Patch
     by Hugo van Kemenade.

   - gh-83863(257): Support for using *note pathlib.Path: 266. objects
     as context managers has been removed.  Before Python 3.9, exiting
     the context manager marked a path as «closed», which caused some
     (but not all!)  methods to raise when called.  Since Python 3.9,
     using a path as a context manager does nothing.

   - gh-104799(258): Adjust the location of the (see PEP 695(259))
     ‘type_params’ field on *note ast.ClassDef: 1a5e, *note
     ast.AsyncFunctionDef: 1a5f, and *note ast.FunctionDef: 1a60. to
     better preserve backward compatibility.  Patch by Jelle Zijlstra

   - gh-104797(260): Allow *note typing.Protocol: 56b. classes to
     inherit from *note collections.abc.Buffer: 343.  Patch by Jelle
     Zijlstra.

   - gh-104783(261): Remove ‘locale.resetlocale()’ function deprecated
     in Python 3.11.  Patch by Victor Stinner.

   - gh-104780(262): Remove the ‘2to3’ program and the ‘lib2to3’ module,
     deprecated in Python 3.11.  Patch by Victor Stinner.

   - gh-104773(263): PEP 594(264): Remove the ‘telnetlib’ module,
     deprecated in Python 3.11.  Patch by Victor Stinner.

   - gh-104773(265): PEP 594(266): Remove the ‘imghdr’ module,
     deprecated in Python 3.11.  Patch by Victor Stinner.

   - gh-104773(267): PEP 594(268): Remove the ‘cgi’ and ‘cgitb’ modules,
     deprecated in Python 3.11.  Patch by Victor Stinner.

   - gh-104773(269): PEP 594(270): Remove the ‘sndhdr’ module,
     deprecated in Python 3.11.  Patch by Victor Stinner.

   - gh-104372(271): On Linux where *note subprocess: dc. can use the
     ‘vfork()’ syscall for faster spawning, prevent the parent process
     from blocking other threads by dropping the GIL while it waits for
     the vfork’ed child process ‘exec()’ outcome.  This prevents
     spawning a binary from a slow filesystem from blocking the rest of
     the application.

   - gh-99108(272): We now release the GIL around built-in *note
     hashlib: 6c. computations of reasonable size for the SHA families
     and MD5 hash functions, matching what our OpenSSL backed hash
     computations already does.

   - gh-102613(273): Improve performance of *note pathlib.Path.glob():
     538. when expanding a pattern with a non-terminal «‘**’» component
     by filtering walked paths through a regular expression, rather than
     calling *note os.scandir(): c56. more than once on each directory.

   - gh-104399(274): Prepare the ‘_tkinter’ module for building with Tcl
     9.0 and future libtommath by replacing usage of deprecated
     functions ‘mp_to_unsigned_bin_n()’ and ‘mp_unsigned_bin_size()’
     when necessary.

   - gh-102676(275): Add fields ‘start_offset’, ‘cache_offset’,
     ‘end_offset’, ‘baseopname’, ‘baseopcode’, ‘jump_target’ and ‘oparg’
     to *note dis.Instruction: 203.

   - gh-103558(276): Fixed ‘parent’ argument validation mechanism of
     *note argparse: 7.  Improved test coverage.

   - gh-103464(277): Provide helpful usage messages when parsing
     incorrect *note pdb: aa. commands.

   - gh-103384(278): Generalize the regex pattern
     ‘BaseConfigurator.INDEX_PATTERN’ to allow spaces and
     non-alphanumeric characters in keys.

   - gh-103124(279): Added multiline statement support for *note pdb:
     aa.

   - gh-101162(280): Forbid using ‘builtins.issubclass()’ with *note
     types.GenericAlias: 9ee. as the first argument.

   - gh-103200(281): Fix cache repopulation semantics of
     zipimport.invalidate_caches().  The cache is now repopulated upon
     retrieving files with an invalid cache, not when the cache is
     invalidated.

   - gh-100061(282): Fix a bug that causes wrong matches for regular
     expressions with possessive qualifier.

   - gh-77609(283): Add 'follow_symlinks' argument to *note
     pathlib.Path.glob(): 538. and *note rglob(): 539, defaulting to
     false.

   - gh-102541(284): Hide traceback in *note help(): ad6. prompt, when
     import failed.

   - gh-102120(285): Added a stream mode to ‘tarfile’ that allows for
     reading archives without caching info about the inner files.

   - gh-102029(286): Deprecate passing any arguments to *note
     threading.RLock(): 32e.

   - gh-88233(287): Refactored ‘zipfile._strip_extra’ to use higher
     level abstractions for extras instead of a heavy-state loop.

   - gh-102024(288): Reduce calls of ‘_idle_semaphore.release()’ in
     ‘concurrent.futures.thread._worker()’.

   - gh-73435(289): Add support for recursive wildcards in *note
     pathlib.PurePath.match(): 6d4.

   - gh-84867(290): *note unittest.TestLoader: 593. no longer loads test
     cases from exact *note unittest.TestCase: 2b3. and *note
     unittest.FunctionTestCase: 1a61. classes.

   - gh-99203(291): Restore following CPython <= 3.10.5 behavior of
     *note shutil.make_archive(): 6db.: do not create an empty archive
     if ‘root_dir’ is not a directory, and, in that case, raise *note
     FileNotFoundError: 264. or *note NotADirectoryError: 125c.
     regardless of ‘format’ choice.  Beyond the brought-back behavior,
     the function may now also raise these exceptions in ‘dry_run’ mode.

   - gh-80480(292): Emit *note DeprecationWarning: 1a3. for *note array:
     8.’s ‘'u'’ type code, deprecated in docs since Python 3.3.

   - gh-94924(293): *note unittest.mock.create_autospec(): 191c. now
     properly returns coroutine functions compatible with *note
     inspect.iscoroutinefunction(): 30d.

   - gh-94777(294): Fix hanging *note multiprocessing: 98.
     ‘ProcessPoolExecutor’ when a child process crashes while data is
     being written in the call queue.

   - gh-92871(295): Remove the ‘typing.io’ and ‘typing.re’ namespaces,
     deprecated since Python 3.8.  All items are still available from
     the main *note typing: 10a. module.

   - bpo-43633(296): Improve the textual representation of IPv4-mapped
     IPv6 addresses ( RFC 4291(297) Sections 2.2, 2.5.5.2) in *note
     ipaddress: 84.  Patch by Oleksandr Pavliuk.

   - bpo-44850(298): Improve performance of *note
     operator.methodcaller(): 1036. using the PEP 590(299) ‘vectorcall’
     convention.  Patch by Anthony Lee and Pieter Eendebak.

   - bpo-44185(300): *note unittest.mock.mock_open(): 11e9. will call
     the ‘close()’ method of the file handle mock when it is exiting
     from the context manager.  Patch by Samet Yaslan.

   - bpo-40988(301): Improve performance of *note
     functools.singledispatchmethod: be5. by caching the generated
     dispatch wrapper.  Optimization suggested by frederico.  Patch by
     @mental32, Alex Waygood and Pieter Eendebak.

   - bpo-41768(302): *note unittest.mock: 10d. speccing no longer calls
     class properties.  Patch by Melanie Witt.

   - bpo-18319(303): Ensure ‘gettext(msg)’ retrieve translations even if
     a plural form exists.  In other words: ‘gettext(msg) ==
     ngettext(msg, '', 1)’.

   - bpo-17013(304): Add ‘ThreadingMock’ to *note unittest.mock: 10d.
     that can be used to create Mock objects that can wait until they
     are called.  Patch by Karthikeyan Singaravelan and Mario Corchero.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/110786

   (2) https://github.com/python/cpython/issues/103480

   (3) https://github.com/python/cpython/issues/110733

   (4) https://github.com/python/cpython/issues/94597

   (5) https://github.com/python/cpython/issues/110682

   (6) https://github.com/python/cpython/issues/110488

   (7) https://github.com/python/cpython/issues/110590

   (8) https://github.com/python/cpython/issues/65052

   (9) https://github.com/python/cpython/issues/110519

   (10) https://github.com/python/cpython/issues/89902

   (11) https://github.com/python/cpython/issues/110378

   (12) https://github.com/python/cpython/issues/106670

   (13) https://github.com/python/cpython/issues/110365

   (14) https://github.com/python/cpython/issues/109653

   (15) https://github.com/python/cpython/issues/110273

   (16) https://github.com/python/cpython/issues/110249

   (17) https://github.com/python/cpython/issues/109653

   (18) https://github.com/python/cpython/issues/110222

   (19) https://github.com/python/cpython/issues/109649

   (20) https://github.com/python/cpython/issues/110150

   (21) https://github.com/python/cpython/issues/110036

   (22) https://github.com/python/cpython/issues/110038

   (23) https://github.com/python/cpython/issues/110045

   (24) https://peps.python.org/pep-0695/

   (25) https://github.com/python/cpython/issues/88402

   (26) https://github.com/python/cpython/issues/109631

   (27) https://github.com/python/cpython/issues/109653

   (28) https://github.com/python/cpython/issues/109818

   (29) https://github.com/python/cpython/issues/109047

   (30) https://github.com/python/cpython/issues/109782

   (31) https://github.com/python/cpython/issues/109653

   (32) https://github.com/python/cpython/issues/109590

   (33) https://github.com/python/cpython/issues/109653

   (34) https://github.com/python/cpython/issues/109593

   (35) https://github.com/python/cpython/issues/109653

   (36) https://github.com/python/cpython/issues/109649

   (37) https://github.com/python/cpython/issues/74481

   (38) https://github.com/python/cpython/issues/109613

   (39) https://github.com/python/cpython/issues/109599

   (40) https://github.com/python/cpython/issues/109109

   (41) https://github.com/python/cpython/issues/109559

   (42) https://github.com/python/cpython/issues/109543

   (43) https://github.com/python/cpython/issues/109495

   (44) https://github.com/python/cpython/issues/109461

   (45) https://github.com/python/cpython/issues/109096

   (46) https://github.com/python/cpython/issues/109409

   (47) https://github.com/python/cpython/issues/109375

   (48) https://github.com/python/cpython/issues/109319

   (49) https://github.com/python/cpython/issues/107219

   (50) https://github.com/python/cpython/issues/66143

   (51) https://github.com/python/cpython/issues/109187

   (52) https://github.com/python/cpython/issues/50644

   (53) https://github.com/python/cpython/issues/109174

   (54) https://github.com/python/cpython/issues/109164

   (55) https://github.com/python/cpython/issues/109151

   (56) https://github.com/python/cpython/issues/108987

   (57) https://github.com/python/cpython/issues/108682

   (58) https://github.com/python/cpython/issues/109033

   (59) https://github.com/python/cpython/issues/108843

   (60) https://github.com/python/cpython/issues/108469

   (61) https://github.com/python/cpython/issues/108751

   (62) https://github.com/python/cpython/issues/108682

   (63) https://github.com/python/cpython/issues/108278

   (64) https://github.com/python/cpython/issues/105829

   (65) https://github.com/python/cpython/issues/108295

   (66) https://github.com/python/cpython/issues/108463

   (67) https://github.com/python/cpython/issues/108277

   (68) https://github.com/python/cpython/issues/107811

   (69) https://github.com/python/cpython/issues/64662

   (70) https://github.com/python/cpython/issues/108111

   (71) https://github.com/python/cpython/issues/101251

   (72) https://github.com/python/cpython/issues/108294

   (73) https://github.com/python/cpython/issues/108278

   (74) https://github.com/python/cpython/issues/108322

   (75) https://github.com/python/cpython/issues/83417

   (76) https://github.com/python/cpython/issues/105736

   (77) https://github.com/python/cpython/issues/108083

   (78) https://github.com/python/cpython/issues/107932

   (79) https://github.com/python/cpython/issues/105539

   (80) https://github.com/python/cpython/issues/107995

   (81) https://github.com/python/cpython/issues/107963

   (82) https://github.com/python/cpython/issues/106242

   (83) https://github.com/python/cpython/issues/81555

   (84) https://github.com/python/cpython/issues/50002

   (85) https://github.com/python/cpython/issues/93057

   (86) https://github.com/python/cpython/issues/76913

   (87) https://github.com/python/cpython/issues/107913

   (88) https://github.com/python/cpython/issues/107845

   (89) https://github.com/python/cpython/issues/107812

   (90) https://github.com/python/cpython/issues/107805

   (91) https://github.com/python/cpython/issues/107782

   (92) https://github.com/python/cpython/issues/56166

   (93) https://github.com/python/cpython/issues/107710

   (94) https://github.com/python/cpython/issues/107715

   (95) https://github.com/python/cpython/issues/100814

   (96) https://github.com/python/cpython/issues/72684

   (97) https://github.com/python/cpython/issues/106684

   (98) https://github.com/python/cpython/issues/107465

   (99) https://github.com/python/cpython/issues/107077

   (100) https://github.com/python/cpython/issues/107576

   (101) https://github.com/python/cpython/issues/105481

   (102) https://github.com/python/cpython/issues/105481

   (103) https://github.com/python/cpython/issues/107396

   (104) https://github.com/python/cpython/issues/107409

   (105) https://github.com/python/cpython/issues/107406

   (106) https://github.com/python/cpython/issues/107369

   (107) https://github.com/python/cpython/issues/78722

   (108) https://github.com/python/cpython/issues/105578

   (109) https://github.com/python/cpython/issues/62519

   (110) https://github.com/python/cpython/issues/107089

   (111) https://github.com/python/cpython/issues/82500

   (112) https://github.com/python/cpython/issues/83006

   (113) https://github.com/python/cpython/issues/65495

   (114) https://github.com/python/cpython/issues/106186

   (115) https://github.com/python/cpython/issues/105002

   (116) https://github.com/python/cpython/issues/106739

   (117) https://github.com/python/cpython/issues/106751

   (118) https://github.com/python/cpython/issues/106751

   (119) https://github.com/python/cpython/issues/106751

   (120) https://github.com/python/cpython/issues/106831

   (121) https://github.com/python/cpython/issues/105481

   (122) https://github.com/python/cpython/issues/106727

   (123) https://github.com/python/cpython/issues/106789

   (124) https://github.com/python/cpython/issues/105726

   (125) https://github.com/python/cpython/issues/106774

   (126) https://github.com/python/cpython/issues/106751

   (127) https://github.com/python/cpython/issues/106752

   (128) https://github.com/python/cpython/issues/105293

   (129) https://github.com/python/cpython/issues/106734

   (130) https://github.com/python/cpython/issues/105481

   (131) https://github.com/python/cpython/issues/106670

   (132) https://github.com/python/cpython/issues/106602

   (133) https://github.com/python/cpython/issues/106664

   (134) https://github.com/python/cpython/issues/106628

   (135) https://github.com/python/cpython/issues/89427

   (136) https://github.com/python/cpython/issues/106530

   (137) https://github.com/python/cpython/issues/106584

   (138) https://github.com/python/cpython/issues/106566

   (139) https://github.com/python/cpython/issues/106554

   (140) https://github.com/python/cpython/issues/106558

   (141) https://github.com/python/cpython/issues/100502

   (142) https://github.com/python/cpython/issues/106527

   (143) https://github.com/python/cpython/issues/106524

   (144) https://github.com/python/cpython/issues/106531

   (145) https://github.com/python/cpython/issues/106052

   (146) https://github.com/python/cpython/issues/106510

   (147) https://github.com/python/cpython/issues/106503

   (148) https://github.com/python/cpython/issues/105497

   (149) https://github.com/python/cpython/issues/90876

   (150) https://github.com/python/cpython/issues/106403

   (151) https://github.com/python/cpython/issues/89812

   (152) https://github.com/python/cpython/issues/106292

   (153) https://github.com/python/cpython/issues/106350

   (154) https://github.com/python/cpython/issues/106330

   (155) https://github.com/python/cpython/issues/106309

   (156) https://github.com/python/cpython/issues/102541

   (157) https://github.com/python/cpython/issues/106263

   (158) https://github.com/python/cpython/issues/106236

   (159) https://github.com/python/cpython/issues/106238

   (160) https://github.com/python/cpython/issues/106152

   (161) https://github.com/python/cpython/issues/106075

   (162) https://github.com/python/cpython/issues/104527

   (163) https://github.com/python/cpython/issues/106046

   (164) https://github.com/python/cpython/issues/105987

   (165) https://github.com/python/cpython/issues/105974

   (166) https://github.com/python/cpython/issues/96145

   (167) https://github.com/python/cpython/issues/89812

   (168) https://github.com/python/cpython/issues/105808

   (169) https://github.com/python/cpython/issues/101251

   (170) https://github.com/python/cpython/issues/105481

   (171) https://github.com/python/cpython/issues/104799

   (172) https://peps.python.org/pep-0695/

   (173) https://github.com/python/cpython/issues/105793

   (174) https://github.com/python/cpython/issues/105570

   (175) https://github.com/python/cpython/issues/105745

   (176) https://github.com/python/cpython/issues/105733

   (177) https://github.com/python/cpython/issues/105687

   (178) https://github.com/python/cpython/issues/105684

   (179) https://github.com/python/cpython/issues/105375

   (180) https://github.com/python/cpython/issues/105626

   (181) https://github.com/python/cpython/issues/105375

   (182) https://github.com/python/cpython/issues/105605

   (183) https://github.com/python/cpython/issues/105375

   (184) https://github.com/python/cpython/issues/105375

   (185) https://github.com/python/cpython/issues/105375

   (186) https://github.com/python/cpython/issues/105375

   (187) https://github.com/python/cpython/issues/105375

   (188) https://github.com/python/cpython/issues/105375

   (189) https://github.com/python/cpython/issues/105375

   (190) https://github.com/python/cpython/issues/105375

   (191) https://github.com/python/cpython/issues/105375

   (192) https://github.com/python/cpython/issues/105566

   (193) https://github.com/python/cpython/issues/105545

   (194) https://github.com/python/cpython/issues/105497

   (195) https://github.com/python/cpython/issues/105509

   (196) https://github.com/python/cpython/issues/105375

   (197) https://github.com/python/cpython/issues/70303

   (198) https://github.com/python/cpython/issues/105375

   (199) https://github.com/python/cpython/issues/105382

   (200) https://github.com/python/cpython/issues/105376

   (201) https://github.com/python/cpython/issues/105332

   (202) https://github.com/python/cpython/issues/104554

   (203) https://github.com/python/cpython/issues/105292

   (204) https://github.com/python/cpython/issues/105280

   (205) https://github.com/python/cpython/issues/80480

   (206) https://github.com/python/cpython/issues/105239

   (207) https://github.com/python/cpython/issues/104310

   (208) https://github.com/python/cpython/issues/105080

   (209) https://github.com/python/cpython/issues/105144

   (210) https://github.com/python/cpython/issues/62948

   (211) https://github.com/python/cpython/issues/105096

   (212) https://github.com/python/cpython/issues/104992

   (213) https://github.com/python/cpython/issues/104996

   (214) https://github.com/python/cpython/issues/101588

   (215) https://github.com/python/cpython/issues/103631

   (216) https://github.com/python/cpython/issues/104947

   (217) https://github.com/python/cpython/issues/104773

   (218) https://peps.python.org/pep-0594/

   (219) https://github.com/python/cpython/issues/104773

   (220) https://peps.python.org/pep-0594/

   (221) https://github.com/python/cpython/issues/104773

   (222) https://peps.python.org/pep-0594/

   (223) https://github.com/python/cpython/issues/104935

   (224) https://peps.python.org/pep-0695/

   (225) https://github.com/python/cpython/issues/104773

   (226) https://peps.python.org/pep-0594/

   (227) https://github.com/python/cpython/issues/104773

   (228) https://peps.python.org/pep-0594/

   (229) https://github.com/python/cpython/issues/104898

   (230) https://github.com/python/cpython/issues/104773

   (231) https://peps.python.org/pep-0594/

   (232) https://github.com/python/cpython/issues/104773

   (233) https://peps.python.org/pep-0594/

   (234) https://github.com/python/cpython/issues/104886

   (235) https://github.com/python/cpython/issues/104786

   (236) https://github.com/python/cpython/issues/104876

   (237) https://github.com/python/cpython/issues/104773

   (238) https://peps.python.org/pep-0594/

   (239) https://github.com/python/cpython/issues/104773

   (240) https://peps.python.org/pep-0594/

   (241) https://pypi.org/project/python-pam/

   (242) https://github.com/python/cpython/issues/75552

   (243) https://github.com/python/cpython/issues/104773

   (244) https://peps.python.org/pep-0594/

   (245) https://github.com/python/cpython/issues/104773

   (246) https://peps.python.org/pep-0594/

   (247) https://github.com/python/cpython/issues/104773

   (248) https://peps.python.org/pep-0594/

   (249) https://github.com/python/cpython/issues/104780

   (250) https://peps.python.org/pep-0594/

   (251) https://github.com/python/cpython/issues/104773

   (252) https://peps.python.org/pep-0594/

   (253) https://github.com/python/cpython/issues/104873

   (254) https://github.com/python/cpython/issues/104874

   (255) https://github.com/python/cpython/issues/104835

   (256) https://github.com/python/cpython/issues/104804

   (257) https://github.com/python/cpython/issues/83863

   (258) https://github.com/python/cpython/issues/104799

   (259) https://peps.python.org/pep-0695/

   (260) https://github.com/python/cpython/issues/104797

   (261) https://github.com/python/cpython/issues/104783

   (262) https://github.com/python/cpython/issues/104780

   (263) https://github.com/python/cpython/issues/104773

   (264) https://peps.python.org/pep-0594/

   (265) https://github.com/python/cpython/issues/104773

   (266) https://peps.python.org/pep-0594/

   (267) https://github.com/python/cpython/issues/104773

   (268) https://peps.python.org/pep-0594/

   (269) https://github.com/python/cpython/issues/104773

   (270) https://peps.python.org/pep-0594/

   (271) https://github.com/python/cpython/issues/104372

   (272) https://github.com/python/cpython/issues/99108

   (273) https://github.com/python/cpython/issues/102613

   (274) https://github.com/python/cpython/issues/104399

   (275) https://github.com/python/cpython/issues/102676

   (276) https://github.com/python/cpython/issues/103558

   (277) https://github.com/python/cpython/issues/103464

   (278) https://github.com/python/cpython/issues/103384

   (279) https://github.com/python/cpython/issues/103124

   (280) https://github.com/python/cpython/issues/101162

   (281) https://github.com/python/cpython/issues/103200

   (282) https://github.com/python/cpython/issues/100061

   (283) https://github.com/python/cpython/issues/77609

   (284) https://github.com/python/cpython/issues/102541

   (285) https://github.com/python/cpython/issues/102120

   (286) https://github.com/python/cpython/issues/102029

   (287) https://github.com/python/cpython/issues/88233

   (288) https://github.com/python/cpython/issues/102024

   (289) https://github.com/python/cpython/issues/73435

   (290) https://github.com/python/cpython/issues/84867

   (291) https://github.com/python/cpython/issues/99203

   (292) https://github.com/python/cpython/issues/80480

   (293) https://github.com/python/cpython/issues/94924

   (294) https://github.com/python/cpython/issues/94777

   (295) https://github.com/python/cpython/issues/92871

   (296) https://bugs.python.org/issue?@action=redirect&bpo=43633

   (297) https://datatracker.ietf.org/doc/html/rfc4291.html

   (298) https://bugs.python.org/issue?@action=redirect&bpo=44850

   (299) https://peps.python.org/pep-0590/

   (300) https://bugs.python.org/issue?@action=redirect&bpo=44185

   (301) https://bugs.python.org/issue?@action=redirect&bpo=40988

   (302) https://bugs.python.org/issue?@action=redirect&bpo=41768

   (303) https://bugs.python.org/issue?@action=redirect&bpo=18319

   (304) https://bugs.python.org/issue?@action=redirect&bpo=17013


File: python.info,  Node: Documentation<19>,  Next: Tests<19>,  Prev: Library<63>,  Up: Python 3 13 0 alpha 1

1.24.25.4 Documentation
.......................

   - gh-109209(1): The minimum Sphinx version required for the
     documentation is now 4.2.

   - gh-108826(2): *note dis: 3c. module command-line interface is now
     mentioned in documentation.

   - gh-107305(3): Add documentation for *note PyInterpreterConfig: 78f.
     and *note Py_NewInterpreterFromConfig(): 68a.  Also clarify some of
     the nearby docs relative to per-interpreter GIL.

   - gh-107008(4): Document the *note curses: 2f. module variables *note
     LINES: fee. and *note COLS: fef.

   - gh-106948(5): Add a number of standard external names to
     ‘nitpick_ignore’.

   - gh-106232(6): Make timeit doc command lines compatible with Windows
     by using double quotes for arguments.  This works on linux and
     macOS also.

   - gh-105172(7): Fixed *note functools.lru_cache(): be4. docstring
     accounting for ‘typed’ argument’s different handling of str and
     int.  Patch by Bar Harel.

   - gh-105052(8): Update ‘timeit’ doc to specify that time in seconds
     is just the default.

   - gh-89455(9): Add missing documentation for the ‘max_group_depth’
     and ‘max_group_width’ parameters and the ‘exceptions’ attribute of
     the *note traceback.TracebackException: 563. class.

   - gh-89412(10): Add missing documentation for the ‘end_lineno’ and
     ‘end_offset’ attributes of the *note traceback.TracebackException:
     563. class.

   - gh-104943(11): Remove mentions of old Python versions in *note
     typing.NamedTuple: 331.

   - gh-54738(12): Add documentation on how to localize the *note
     argparse: 7. module.

   - gh-102823(13): Document the return type of ‘x // y’ when ‘x’ and
     ‘y’ have type *note float: 196.

   - gh-102759(14): Align function signature for ‘functools.reduce’ in
     documentation and docstring with the C implementation.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109209

   (2) https://github.com/python/cpython/issues/108826

   (3) https://github.com/python/cpython/issues/107305

   (4) https://github.com/python/cpython/issues/107008

   (5) https://github.com/python/cpython/issues/106948

   (6) https://github.com/python/cpython/issues/106232

   (7) https://github.com/python/cpython/issues/105172

   (8) https://github.com/python/cpython/issues/105052

   (9) https://github.com/python/cpython/issues/89455

   (10) https://github.com/python/cpython/issues/89412

   (11) https://github.com/python/cpython/issues/104943

   (12) https://github.com/python/cpython/issues/54738

   (13) https://github.com/python/cpython/issues/102823

   (14) https://github.com/python/cpython/issues/102759


File: python.info,  Node: Tests<19>,  Next: Build<22>,  Prev: Documentation<19>,  Up: Python 3 13 0 alpha 1

1.24.25.5 Tests
...............

   - gh-110647(1): Fix test_stress_modifying_handlers() of test_signal.
     Patch by Victor Stinner.

   - gh-103053(2): Fix test_tools.test_freeze on FreeBSD: run «make
     distclean» instead of «make clean» in the copied source directory
     to remove also the «python» program.  Patch by Victor Stinner.

   - gh-110167(3): Fix a deadlock in test_socket when server fails with
     a timeout but the client is still running in its thread.  Don’t
     hold a lock to call cleanup functions in doCleanups().  One of the
     cleanup function waits until the client completes, whereas the
     client could deadlock if it called addCleanup() in such situation.
     Patch by Victor Stinner.

   - gh-110388(4): Add tests for *note tty: 106.

   - gh-81002(5): Add tests for *note termios: e7.

   - gh-110367(6): regrtest: When using worker processes (-jN) with
     –verbose3 option, regrtest can now display the worker output even
     if a worker process does crash.  Previously, sys.stdout and
     sys.stderr were replaced and so the worker output was lost on a
     crash.  Patch by Victor Stinner.

   - gh-110267(7): Add tests for pickling and copying PyStructSequence
     objects.  Patched by Xuehai Pan.

   - gh-110171(8): ‘libregrtest’ now always sets and shows
     ‘random.seed’, so tests are more reproducible.  Use ‘--randseed’
     flag to pass the explicit random seed for tests.

   - gh-110152(9): Remove ‘Tools/scripts/run_tests.py’ and ‘make
     hostrunnertest’.  Just run ‘./python -m test --slow-ci’, ‘make
     buildbottest’ or ‘make test’ instead.  Python test runner
     (regrtest) now handles cross-compilation and HOSTRUNNER. It also
     adds options to Python such fast ‘-u -E -W default -bb’ when
     ‘--fast-ci’ or ‘--slow-ci’ option is used.  Patch by Victor
     Stinner.

   - gh-110031(10): Skip test_threading tests using thread+fork if
     Python is built with Address Sanitizer (ASAN). Patch by Victor
     Stinner.

   - gh-110088(11): Fix test_asyncio timeouts: don’t measure the maximum
     duration, a test should not measure a CI performance.  Only measure
     the minimum duration when a task has a timeout or delay.  Add
     ‘CLOCK_RES’ to ‘test_asyncio.utils’.  Patch by Victor Stinner.

   - gh-109974(12): Fix race conditions in test_threading lock tests.
     Wait until a condition is met rather than using *note time.sleep():
     8ad. with a hardcoded number of seconds.  Patch by Victor Stinner.

   - gh-110033(13): Fix ‘test_interprocess_signal()’ of ‘test_signal’.
     Make sure that the ‘subprocess.Popen’ object is deleted before the
     test raising an exception in a signal handler.  Otherwise,
     ‘Popen.__del__()’ can get the exception which is logged as
     ‘Exception ignored in: ...’ and the test fails.  Patch by Victor
     Stinner.

   - gh-109594(14): Fix test_timeout() of
     test_concurrent_futures.test_wait.  Remove the future which may or
     may not complete depending if it takes longer than the timeout or
     not.  Keep the second future which does not complete before wait()
     timeout.  Patch by Victor Stinner.

   - gh-109972(15): Split test_gdb.py file into a test_gdb package made
     of multiple tests, so tests can now be run in parallel.  Patch by
     Victor Stinner.

   - gh-109566(16): regrtest: When ‘--fast-ci’ or ‘--slow-ci’ option is
     used, regrtest now replaces the current process with a new process
     to add ‘-u -W default -bb -E’ options to Python.  Patch by Victor
     Stinner.

   - gh-109748(17): Fix ‘test_zippath_from_non_installed_posix()’ of
     test_venv: don’t copy ‘__pycache__/’ sub-directories, because they
     can be modified by other Python tests running in parallel.  Patch
     by Victor Stinner.

   - gh-109739(18): regrtest: Fix reference leak check on Windows.
     Disable the load tracker on Windows in the reference leak check
     mode (-R option).  Patch by Victor Stinner.

   - gh-109276(19): regrtest: When a test fails with «env changed» and
     the –rerun option is used, the test is now re-run in verbose mode
     in a fresh process.  Patch by Victor Stinner.

   - gh-103053(20): Skip test_freeze_simple_script() of
     test_tools.test_freeze if Python is built with ‘./configure
     --enable-optimizations’, which means with Profile Guided
     Optimization (PGO): it just makes the test too slow.  The freeze
     tool is tested by many other CIs with other (faster) compiler
     flags.  Patch by Victor Stinner.

   - gh-109580(21): Skip ‘test_perf_profiler’ if Python is built with
     ASAN, MSAN or UBSAN sanitizer.  Python does crash randomly in this
     test on such build.  Patch by Victor Stinner.

   - gh-109566(22): regrtest: Add ‘--fast-ci’ and ‘--slow-ci’ options.
     ‘--fast-ci’ uses a default timeout of 10 minutes and ‘-u all,-cpu’
     (skip slowest tests).  ‘--slow-ci’ uses a default timeout of 20
     minutes and ‘-u all’ (run all tests).  Patch by Victor Stinner.

   - gh-109425(23): libregrtest now decodes stdout of test worker
     processes with the «backslashreplace» error handler to log
     corrupted stdout, instead of failing with an error and not logging
     the stdout.  Patch by Victor Stinner.

   - gh-109396(24): Fix ‘test_socket.test_hmac_sha1()’ in FIPS mode.
     Use a longer key: FIPS mode requires at least of at least 112 bits.
     The previous key was only 32 bits.  Patch by Victor Stinner.

   - gh-104736(25): Fix test_gdb on Python built with LLVM clang 16 on
     Linux ppc64le (ex: Fedora 38).  Search patterns in gdb «bt» command
     output to detect when gdb fails to retrieve the traceback.  For
     example, skip a test if ‘Backtrace stopped: frame did not save the
     PC’ is found.  Patch by Victor Stinner.

   - gh-109276(26): libregrtest now calls *note random.seed(): 147b.
     before running each test file when ‘-r/--randomize’ command line
     option is used.  Moreover, it’s also called in worker processes.
     It should help to make tests more deterministic.  Previously, it
     was only called once in the main process before running all test
     files and it was not called in worker processes.  Patch by Victor
     Stinner.

   - gh-109276(27): libregrtest now uses a separated file descriptor to
     write test result as JSON. Previously, if a test wrote debug
     messages late around the JSON, the main test process failed to
     parse JSON. Patch by Victor Stinner.

   - gh-108996(28): Fix and enable ‘test_msvcrt’.

   - gh-109237(29): Fix ‘test_site.test_underpth_basic()’ when the
     working directory contains at least one non-ASCII character: encode
     the ‘._pth’ file to UTF-8 and enable the UTF-8 Mode to use UTF-8
     for the child process stdout.  Patch by Victor Stinner.

   - gh-109230(30): Fix ‘test_pyexpat.test_exception()’: it can now be
     run from a directory different than Python source code directory.
     Before, the test failed in this case.  Skip the test if
     Modules/pyexpat.c source is not available.  Skip also the test on
     Python implementations other than CPython.  Patch by Victor
     Stinner.

   - gh-108996(31): Add tests for ‘msvcrt’.

   - gh-109015(32): Fix test_asyncio, test_imaplib and test_socket tests
     on FreeBSD if the TCP blackhole is enabled (‘sysctl
     net.inet.tcp.blackhole’).  Skip the few tests which failed with
     ‘ETIMEDOUT’ which such non standard configuration.  Currently, the
     FreeBSD GCP image enables TCP and UDP blackhole(33) (‘sysctl
     net.inet.tcp.blackhole=2’ and ‘sysctl net.inet.udp.blackhole=1’).
     Patch by Victor Stinner.

   - gh-91960(34): Skip ‘test_gdb’ if gdb is unable to retrieve Python
     frame objects: if a frame is ‘<optimized out>’.  When Python is
     built with «clang -Og», gdb can fail to retrieve the 'frame'
     parameter of ‘_PyEval_EvalFrameDefault()’.  In this case, tests
     like ‘py_bt()’ are likely to fail.  Without getting access to
     Python frames, ‘python-gdb.py’ is mostly clueless on retrieving the
     Python traceback.  Moreover, ‘test_gdb’ is no longer skipped on
     macOS if Python is built with Clang.  Patch by Victor Stinner.

   - gh-108962(35): Skip ‘test_tempfile.test_flags()’ if ‘chflags()’
     fails with «OSError: [Errno 45] Operation not supported» (ex: on
     FreeBSD 13).  Patch by Victor Stinner.

   - gh-91960(36): FreeBSD 13.2 CI coverage for pull requests is now
     provided by Cirrus-CI (a hosted CI service that supports Linux,
     macOS, Windows, and FreeBSD).

   - gh-89392(37): Removed support of ‘test_main()’ function in tests.
     They now always use normal unittest test runner.

   - gh-108851(38): Fix ‘test_tomllib’ recursion tests for WASI
     buildbots: reduce the recursion limit and compute the maximum
     nested array/dict depending on the current available recursion
     limit.  Patch by Victor Stinner.

   - gh-108851(39): Add ‘get_recursion_available()’ and
     ‘get_recursion_depth()’ functions to the *note test.support: ea.
     module.  Patch by Victor Stinner.

   - gh-108834(40): Add ‘--fail-rerun option’ option to regrtest: if a
     test failed when then passed when rerun in verbose mode, exit the
     process with exit code 2 (error), instead of exit code 0 (success).
     Patch by Victor Stinner.

   - gh-108834(41): Rename regrtest ‘--verbose2’ option (‘-w’) to
     ‘--rerun’.  Keep ‘--verbose2’ as a deprecated alias.  Patch by
     Victor Stinner.

   - gh-108834(42): When regrtest reruns failed tests in verbose mode
     (‘./python -m test --rerun’), tests are now rerun in fresh worker
     processes rather than being executed in the main process.  If a
     test does crash or is killed by a timeout, the main process can
     detect and handle the killed worker process.  Tests are rerun in
     parallel if the ‘-jN’ option is used to run tests in parallel.
     Patch by Victor Stinner.

   - gh-108822(43): ‘regrtest’ now computes statistics on all tests:
     successes, failures and skipped.  ‘test_netrc’,
     ‘test_pep646_syntax’ and ‘test_xml_etree’ now return results in
     their ‘test_main()’ function.  Patch by Victor Stinner and Alex
     Waygood.

   - gh-108794(44): The *note doctest.DocTestRunner.run(): 4ef. method
     now counts the number of skipped tests.  Add *note
     doctest.DocTestRunner.skips: 4f0. and *note
     doctest.TestResults.skipped: 4f1. attributes.  Patch by Victor
     Stinner.

   - gh-108388(45): Convert test_concurrent_futures to a package of 7
     sub-tests.  Patch by Victor Stinner.

   - gh-108388(46): Split test_multiprocessing_fork,
     test_multiprocessing_forkserver and test_multiprocessing_spawn into
     test packages.  Each package is made of 4 sub-tests: processes,
     threads, manager and misc.  It allows running more tests in
     parallel and so reduce the total test duration.  Patch by Victor
     Stinner.

   - gh-105776(47): Fix test_cppext when the C compiler command
     ‘-std=c11’ option: remove ‘-std=’ options from the compiler
     command.  Patch by Victor Stinner.

   - gh-107652(48): Set up CIFuzz to run fuzz targets in GitHub Actions.
     Patch by Illia Volochii.

   - gh-107237(49): ‘test_logging’: Fix ‘test_udp_reconnection()’ by
     increasing the timeout from 100 ms to 5 minutes (LONG_TIMEOUT).
     Patch by Victor Stinner.

   - gh-107178(50): Add the C API test for functions in the Mapping
     Protocol, the Sequence Protocol and some functions in the Object
     Protocol.

   - gh-106714(51): test_capi: Fix test_no_FatalError_infinite_loop() to
     no longer write a coredump, by using
     test.support.SuppressCrashReport.  Patch by Victor Stinner.

   - gh-104090(52): Avoid creating a reference to the test object in
     *note collectedDurations(): 1a64.

   - gh-106752(53): Moved tests for ‘zipfile.Path’ into
     ‘Lib/test/test_zipfile/_path’.  Made ‘zipfile._path’ a package.

   - gh-106690(54): Add .coveragerc to cpython repository for use with
     coverage package.

   - gh-101634(55): When running the Python test suite with ‘-jN’
     option, if a worker stdout cannot be decoded from the locale
     encoding report a failed testn so the exitcode is non-zero.  Patch
     by Victor Stinner.

   - gh-105084(56): When the Python build is configured
     ‘--with-wheel-pkg-dir’, tests requiring the ‘setuptools’ and
     ‘wheel’ wheels will search for the wheels in ‘WHEEL_PKG_DIR’.

   - gh-81005(57): String tests are modified to reflect that ‘str’ and
     ‘unicode’ are merged in Python 3.  Patch by Daniel Fortunov.

   - gh-103186(58): Suppress and assert expected RuntimeWarnings in
     test_sys_settrace.py

   - gh-69714(59): Add additional tests to *note calendar: 15. to
     achieve full test coverage.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/110647

   (2) https://github.com/python/cpython/issues/103053

   (3) https://github.com/python/cpython/issues/110167

   (4) https://github.com/python/cpython/issues/110388

   (5) https://github.com/python/cpython/issues/81002

   (6) https://github.com/python/cpython/issues/110367

   (7) https://github.com/python/cpython/issues/110267

   (8) https://github.com/python/cpython/issues/110171

   (9) https://github.com/python/cpython/issues/110152

   (10) https://github.com/python/cpython/issues/110031

   (11) https://github.com/python/cpython/issues/110088

   (12) https://github.com/python/cpython/issues/109974

   (13) https://github.com/python/cpython/issues/110033

   (14) https://github.com/python/cpython/issues/109594

   (15) https://github.com/python/cpython/issues/109972

   (16) https://github.com/python/cpython/issues/109566

   (17) https://github.com/python/cpython/issues/109748

   (18) https://github.com/python/cpython/issues/109739

   (19) https://github.com/python/cpython/issues/109276

   (20) https://github.com/python/cpython/issues/103053

   (21) https://github.com/python/cpython/issues/109580

   (22) https://github.com/python/cpython/issues/109566

   (23) https://github.com/python/cpython/issues/109425

   (24) https://github.com/python/cpython/issues/109396

   (25) https://github.com/python/cpython/issues/104736

   (26) https://github.com/python/cpython/issues/109276

   (27) https://github.com/python/cpython/issues/109276

   (28) https://github.com/python/cpython/issues/108996

   (29) https://github.com/python/cpython/issues/109237

   (30) https://github.com/python/cpython/issues/109230

   (31) https://github.com/python/cpython/issues/108996

   (32) https://github.com/python/cpython/issues/109015

   (33) https://reviews.freebsd.org/D41751

   (34) https://github.com/python/cpython/issues/91960

   (35) https://github.com/python/cpython/issues/108962

   (36) https://github.com/python/cpython/issues/91960

   (37) https://github.com/python/cpython/issues/89392

   (38) https://github.com/python/cpython/issues/108851

   (39) https://github.com/python/cpython/issues/108851

   (40) https://github.com/python/cpython/issues/108834

   (41) https://github.com/python/cpython/issues/108834

   (42) https://github.com/python/cpython/issues/108834

   (43) https://github.com/python/cpython/issues/108822

   (44) https://github.com/python/cpython/issues/108794

   (45) https://github.com/python/cpython/issues/108388

   (46) https://github.com/python/cpython/issues/108388

   (47) https://github.com/python/cpython/issues/105776

   (48) https://github.com/python/cpython/issues/107652

   (49) https://github.com/python/cpython/issues/107237

   (50) https://github.com/python/cpython/issues/107178

   (51) https://github.com/python/cpython/issues/106714

   (52) https://github.com/python/cpython/issues/104090

   (53) https://github.com/python/cpython/issues/106752

   (54) https://github.com/python/cpython/issues/106690

   (55) https://github.com/python/cpython/issues/101634

   (56) https://github.com/python/cpython/issues/105084

   (57) https://github.com/python/cpython/issues/81005

   (58) https://github.com/python/cpython/issues/103186

   (59) https://github.com/python/cpython/issues/69714


File: python.info,  Node: Build<22>,  Next: Windows<20>,  Prev: Tests<19>,  Up: Python 3 13 0 alpha 1

1.24.25.6 Build
...............

   - gh-103053(1): «make check-clean-src» now also checks if the
     «python» program is found in the source directory: fail with an
     error if it does exist.  Patch by Victor Stinner.

   - gh-109191(2): Fix compile error when building with recent versions
     of libedit.

   - gh-110276(3): No longer ignore *note PROFILE_TASK: 1a66. failure
     silently: command used by Profile Guided Optimization (PGO). Patch
     by Victor Stinner.

   - gh-109566(4): Remove ‘make testall’ target: use ‘make buildbottest’
     instead.  Patch by Victor Stinner.

   - gh-109740(5): The experimental ‘--disable-gil’ configure flag now
     includes «t» (for «threaded») in extension ABI tags.

   - gh-109054(6): Fix building the ‘_testcapi’ extension on Linux
     AArch64 which requires linking to libatomic when
     ‘<cpython/pyatomic.h>’ is used: the ‘_Py_atomic_or_uint64()’
     function requires libatomic ‘__atomic_fetch_or_8()’ on this
     platform.  The configure script now checks if linking to libatomic
     is needed and generates a new LIBATOMIC variable used to build the
     _testcapi extension.  Patch by Victor Stinner.

   - gh-63760(7): Fix Solaris build: no longer redefine the
     ‘gethostname()’ function.  Solaris defines the function since 2005.
     Patch by Victor Stinner, original patch by Jakub Kulík.

   - gh-108740(8): Fix a race condition in ‘make regen-all’.  The
     ‘deepfreeze.c’ source and files generated by Argument Clinic are
     now generated or updated before generating «global objects».
     Previously, some identifiers may miss depending on the order in
     which these files were generated.  Patch by Victor Stinner.

   - gh-108634(9): Python built with ‘configure’ *note -with-trace-refs:
     636. (tracing references) is now ABI compatible with Python release
     build and *note debug build: 50a.  Patch by Victor Stinner.

   - gh-85283(10): The ‘_stat’ C extension is now built with the *note
     limited C API: 637.  Patch by Victor Stinner.

   - gh-108447(11): Fix x86_64 GNU/Hurd build

   - gh-107814(12): When calling ‘find_python.bat’ with ‘-q’ it did not
     properly silence the output of nuget.  That is now fixed.

   - gh-105481(13): Remove the make target ‘regen-opcode-targets’, merge
     its work into ‘regen-opcode’ which repeats most of the calculation.
     This simplifies the code for the build and reduces code
     duplication.

   - gh-106881(14): Check for ‘linux/limits.h’ before including it in
     ‘Modules/posixmodule.c’.

   - gh-95855(15): Refactor platform triplet detection code and add
     detection for MIPS soft float and musl libc.

   - gh-106962(16): Detect MPI compilers in ‘configure’.

   - gh-106118(17): Fix compilation for platforms without ‘O_CLOEXEC’.
     The issue was introduced with Python 3.12b1 in gh-103295(18).
     Patch by Erlend Aasland.

   - gh-105875(19): SQLite 3.15.2 or newer is required to build the
     *note sqlite3: d4. extension module.  Patch by Erlend Aasland.

   - gh-90005(20): Fix a regression in ‘configure’ where we could end up
     unintentionally linking with ‘libbsd’.

   - gh-102404(21): Document how to perform a WASI build on Linux.  Also
     add Tools/wasm/build_wasi.sh as a reference implementation of the
     docs.

   - gh-89886(22): Autoconf 2.71 and aclocal 1.16.4 is now required to
     regenerate ‘configure’.

   - gh-104692(23): Include ‘commoninstall’ as a prerequisite for
     ‘bininstall’

     This ensures that ‘commoninstall’ is completed before ‘bininstall’
     is started when parallel builds are used (‘make -j install’), and
     so the ‘python3’ symlink is only installed after all standard
     library modules are installed.

   - gh-101538(24): Add experimental wasi-threads support.  Patch by
     Takashi Yamamoto.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/103053

   (2) https://github.com/python/cpython/issues/109191

   (3) https://github.com/python/cpython/issues/110276

   (4) https://github.com/python/cpython/issues/109566

   (5) https://github.com/python/cpython/issues/109740

   (6) https://github.com/python/cpython/issues/109054

   (7) https://github.com/python/cpython/issues/63760

   (8) https://github.com/python/cpython/issues/108740

   (9) https://github.com/python/cpython/issues/108634

   (10) https://github.com/python/cpython/issues/85283

   (11) https://github.com/python/cpython/issues/108447

   (12) https://github.com/python/cpython/issues/107814

   (13) https://github.com/python/cpython/issues/105481

   (14) https://github.com/python/cpython/issues/106881

   (15) https://github.com/python/cpython/issues/95855

   (16) https://github.com/python/cpython/issues/106962

   (17) https://github.com/python/cpython/issues/106118

   (18) https://github.com/python/cpython/issues/103295

   (19) https://github.com/python/cpython/issues/105875

   (20) https://github.com/python/cpython/issues/90005

   (21) https://github.com/python/cpython/issues/102404

   (22) https://github.com/python/cpython/issues/89886

   (23) https://github.com/python/cpython/issues/104692

   (24) https://github.com/python/cpython/issues/101538


File: python.info,  Node: Windows<20>,  Next: macOS<13>,  Prev: Build<22>,  Up: Python 3 13 0 alpha 1

1.24.25.7 Windows
.................

   - gh-110437(1): Allows overriding the source of VC redistributables
     so that releases can be guaranteed to never downgrade between
     updates.

   - gh-109286(2): Update Windows installer to use SQLite 3.43.1.

   - gh-82367(3): *note os.path.realpath(): 262. now resolves MS-DOS
     style file names even if the file is not accessible.  Patch by
     Moonsik Park.

   - gh-109991(4): Update Windows build to use OpenSSL 3.0.11.

   - gh-106242(5): Fixes *note realpath(): 262. to behave consistently
     when passed a path containing an embedded null character on
     Windows.  In strict mode, it now raises *note OSError: 2c0. instead
     of the unexpected *note ValueError: 2ec, and in non-strict mode
     will make the path absolute.

   - gh-83180(6): Changes the *note Python install manager: 7db. to
     prefer an active virtual environment when the launched script has a
     shebang line using a Unix-like virtual command, even if the command
     requests a specific version of Python.

   - gh-106844(7): Fix integer overflow and truncating by the null
     character in ‘_winapi.LCMapStringEx()’ which affects
     ‘ntpath.normcase()’.

   - gh-105436(8): Ensure that an empty environment block is terminated
     by two null characters, as is required by Windows.

   - gh-105146(9): Updated the links at the end of the installer to
     point to Discourse rather than the mailing lists.

   - gh-103646(10): When installed from the Microsoft Store, ‘pip’ no
     longer defaults to per-user installs.  However, as the install
     directory is unwritable, it should automatically decide to do a
     per-user install anyway.  This should resolve issues when ‘pip’ is
     passed an option that conflicts with ‘--user’.

   - gh-88745(11): Improve performance of *note shutil.copy2(): c52. by
     using the operating system’s ‘CopyFile2’ function.  This may result
     in subtle changes to metadata copied along with some files,
     bringing them in line with normal OS behavior.

   - gh-104820(12): Fixes *note stat(): 26d. and related functions on
     file systems that do not support file ID requests.  This includes
     FAT32 and exFAT.

   - gh-104803(13): Add *note os.path.isdevdrive(): 19aa. to detect
     whether a path is on a Windows Dev Drive.  Returns ‘False’ on
     platforms that do not support Dev Drive, and is absent on
     non-Windows platforms.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/110437

   (2) https://github.com/python/cpython/issues/109286

   (3) https://github.com/python/cpython/issues/82367

   (4) https://github.com/python/cpython/issues/109991

   (5) https://github.com/python/cpython/issues/106242

   (6) https://github.com/python/cpython/issues/83180

   (7) https://github.com/python/cpython/issues/106844

   (8) https://github.com/python/cpython/issues/105436

   (9) https://github.com/python/cpython/issues/105146

   (10) https://github.com/python/cpython/issues/103646

   (11) https://github.com/python/cpython/issues/88745

   (12) https://github.com/python/cpython/issues/104820

   (13) https://github.com/python/cpython/issues/104803


File: python.info,  Node: macOS<13>,  Next: IDLE<13>,  Prev: Windows<20>,  Up: Python 3 13 0 alpha 1

1.24.25.8 macOS
...............

   - gh-109286(1): Update macOS installer to use SQLite 3.43.1.

   - gh-109991(2): Update macOS installer to use OpenSSL 3.0.11.

   - gh-99079(3): Update macOS installer to use OpenSSL 3.0.9.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109286

   (2) https://github.com/python/cpython/issues/109991

   (3) https://github.com/python/cpython/issues/99079


File: python.info,  Node: IDLE<13>,  Next: Tools/Demos<19>,  Prev: macOS<13>,  Up: Python 3 13 0 alpha 1

1.24.25.9 IDLE
..............

   - gh-104719(1): Remove IDLE’s modification of tokenize.tabsize and
     test other uses of tokenize data and methods.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104719


File: python.info,  Node: Tools/Demos<19>,  Next: C API<22>,  Prev: IDLE<13>,  Up: Python 3 13 0 alpha 1

1.24.25.10 Tools/Demos
......................

   - gh-109991(1): Update GitHub CI workflows to use OpenSSL 3.0.11 and
     multissltests to use 1.1.1w, 3.0.11, and 3.1.3.

   - gh-108494(2): Argument Clinic(3) now has a partial support of the
     *note Limited API: 637.: see documentation in the Python
     Developer's Guide(4) Patch by Victor Stinner.

   - gh-107704(5): It is now possible to deprecate passing keyword
     arguments for keyword-or-positional parameters with Argument
     Clinic, using the new ‘/ [from X.Y]’ syntax.  (To be read as
     '«positional-only from Python version X.Y»'.)  See documentation in
     the Python Developer's Guide(6) for more information.

   - gh-107880(7): Argument Clinic can now clone ‘__init__()’ and
     ‘__new__()’ methods.

   - gh-104683(8): Add ‘--exclude’ option to Argument Clinic CLI.

   - gh-95065(9): Argument Clinic now supports overriding automatically
     generated signature by using directive ‘@text_signature’.  See
     documentation in the Python Developer's Guide(10)

   - gh-107609(11): Fix duplicate module check in Argument Clinic.
     Previously, a duplicate definition would incorrectly be silently
     accepted.  Patch by Erlend E. Aasland.

   - gh-107467(12): The Argument Clinic command-line tool now prints to
     stderr instead of stdout on failure.

   - gh-106970(13): Fix bugs in the Argument Clinic ‘destination <name>
     clear’ command; the destination buffers would never be cleared, and
     the ‘destination’ directive parser would simply continue to the
     fault handler after processing the command.  Patch by Erlend E.
     Aasland.

   - gh-106706(14): Change bytecode syntax for families to remove
     redundant name matching pseudo syntax.

   - gh-106359(15): Argument Clinic now explicitly forbids «kwarg
     splats» in function calls used as annotations.

   - gh-103186(16): ‘freeze’ now fetches ‘CONFIG_ARGS’ from the original
     CPython instance the Makefile uses to call utility scripts.  Patch
     by Ijtaba Hussain.

   - gh-95065(17): It is now possible to deprecate passing parameters
     positionally with Argument Clinic, using the new ‘* [from X.Y]’
     syntax.  (To be read as '«keyword-only from Python version X.Y»'.)
     See documentation in the Python Developer's Guide(18) for more
     information.  Patch by Erlend E. Aasland with help from Alex
     Waygood, Nikita Sobolev, and Serhiy Storchaka.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/109991

   (2) https://github.com/python/cpython/issues/108494

   (3) https://devguide.python.org/development-tools/clinic/

   (4) 
https://devguide.python.org/development-tools/clinic/#clinic-howto-limited-capi

   (5) https://github.com/python/cpython/issues/107704

   (6) 
https://devguide.python.org/development-tools/clinic/#clinic-howto-deprecate-keyword

   (7) https://github.com/python/cpython/issues/107880

   (8) https://github.com/python/cpython/issues/104683

   (9) https://github.com/python/cpython/issues/95065

   (10) 
https://devguide.python.org/development-tools/clinic/#clinic-howto-override-signature

   (11) https://github.com/python/cpython/issues/107609

   (12) https://github.com/python/cpython/issues/107467

   (13) https://github.com/python/cpython/issues/106970

   (14) https://github.com/python/cpython/issues/106706

   (15) https://github.com/python/cpython/issues/106359

   (16) https://github.com/python/cpython/issues/103186

   (17) https://github.com/python/cpython/issues/95065

   (18) 
https://devguide.python.org/development-tools/clinic/#clinic-howto-deprecate-positional


File: python.info,  Node: C API<22>,  Prev: Tools/Demos<19>,  Up: Python 3 13 0 alpha 1

1.24.25.11 C API
................

   - gh-85283(1): If the *note Py_LIMITED_API: 660. macro is defined,
     ‘Py_BUILD_CORE’, ‘Py_BUILD_CORE_BUILTIN’ and ‘Py_BUILD_CORE_MODULE’
     macros are now undefined by ‘<Python.h>’.  Patch by Victor Stinner.

   - gh-110289(2): Add *note PyUnicode_EqualToUTF8AndSize(): 619. and
     *note PyUnicode_EqualToUTF8(): 61a. functions.

   - gh-110235(3): Raise *note TypeError: 198. for duplicate/unknown
     fields in ‘PyStructSequence’ constructor.  Patched by Xuehai Pan.

   - gh-110014(4): Remove undocumented ‘PY_TIMEOUT_MAX’ constant from
     the limited C API. Patch by Victor Stinner.

   - gh-109521(5): *note PyImport_GetImporter(): 1a6c. now sets
     RuntimeError if it fails to get *note sys.path_hooks: 1226. or
     *note sys.path_importer_cache: 7fb. or they are not list and dict
     correspondingly.  Previously it could return NULL without setting
     error in obscure cases, crash or raise SystemError if these
     attributes have wrong type.

   - gh-108724(6): Add *note PyMutex: 485. internal-only lightweight
     locking API.

   - gh-85283(7): Add *note PySys_AuditTuple(): 612. function: similar
     to *note PySys_Audit(): 613, but pass event arguments as a Python
     *note tuple: 614. object.  Patch by Victor Stinner.

   - gh-108867(8): Add *note PyThreadState_GetUnchecked(): 423.
     function: similar to *note PyThreadState_Get(): 615, but don’t kill
     the process with a fatal error if it is NULL. The caller is
     responsible to check if the result is NULL. Previously, the
     function was private and known as ‘_PyThreadState_UncheckedGet()’.
     Patch by Victor Stinner.

   - gh-108765(9): ‘Python.h’ no longer includes the ‘<ctype.h>’
     standard header file.  If needed, it should now be included
     explicitly.  For example, it provides ‘isalpha()’ and ‘tolower()’
     functions which are locale dependent.  Python provides locale
     independent functions, like ‘Py_ISALPHA()’ and ‘Py_TOLOWER()’.
     Patch by Victor Stinner.

   - gh-108765(10): ‘Python.h’ no longer includes the ‘<unistd.h>’
     standard header file.  If needed, it should now be included
     explicitly.  For example, it provides the functions: ‘close()’,
     ‘getpagesize()’, ‘getpid()’ and ‘sysconf()’.  Patch by Victor
     Stinner.

   - gh-108765(11): ‘Python.h’ no longer includes the ‘<ieeefp.h>’
     standard header.  It was included for the ‘finite()’ function which
     is now provided by the ‘<math.h>’ header.  It should now be
     included explicitly if needed.  Remove also the ‘HAVE_IEEEFP_H’
     macro.  Patch by Victor Stinner.

   - gh-108765(12): ‘Python.h’ no longer includes these standard header
     files: ‘<time.h>’, ‘<sys/select.h>’ and ‘<sys/time.h>’.  If needed,
     they should now be included explicitly.  For example, ‘<time.h>’
     provides the ‘clock()’ and ‘gmtime()’ functions, ‘<sys/select.h>’
     provides the ‘select()’ function, and ‘<sys/time.h>’ provides the
     ‘futimes()’, ‘gettimeofday()’ and ‘setitimer()’ functions.  Patch
     by Victor Stinner.

   - gh-108511(13): Add functions *note PyObject_HasAttrWithError():
     61b, *note PyObject_HasAttrStringWithError(): 61d, *note
     PyMapping_HasKeyWithError(): 61f. and *note
     PyMapping_HasKeyStringWithError(): 621.

   - gh-107073(14): Add *note PyObject_VisitManagedDict(): 60d. and
     *note PyObject_ClearManagedDict(): 60e. functions which must be
     called by the traverse and clear functions of a type using *note
     Py_TPFLAGS_MANAGED_DICT: 60f. flag.  Patch by Victor Stinner.

   - gh-108634(15): Python built with ‘configure’ *note
     -with-trace-refs: 636. (tracing references) now supports the *note
     Limited API: 637.  Patch by Victor Stinner.

   - gh-108014(16): Add *note PyLong_AsInt(): 604. function: similar to
     *note PyLong_AsLong(): 605, but store the result in a C int instead
     of a C long.  Previously, it was known as the private function
     ‘_PyLong_AsInt()’ (with an underscore prefix).  Patch by Victor
     Stinner.

   - gh-108314(17): Add *note PyDict_ContainsString(): 5dd. function:
     same as *note PyDict_Contains(): 5de, but 'key' is specified as a
     const char* UTF-8 encoded bytes string, rather than a *note
     PyObject: 5df.*.  Patch by Victor Stinner.

   - gh-108337(18): Add atomic operations on additional data types in
     pyatomic.h.

   - gh-108014(19): Add *note Py_IsFinalizing(): 5fd. function: check if
     the main Python interpreter is *note shutting down: 47a.  Patch by
     Victor Stinner.

   - gh-107916(20): C API functions *note
     PyErr_SetFromErrnoWithFilename(): 1a6d, *note
     PyErr_SetExcFromWindowsErrWithFilename(): 1a6e. and *note
     PyErr_SetFromWindowsErrWithFilename(): 1a6f. save now the error
     code before calling *note PyUnicode_DecodeFSDefault(): 1a70.

   - gh-107915(21): Such C API functions as ‘PyErr_SetString()’,
     ‘PyErr_Format()’, ‘PyErr_SetFromErrnoWithFilename()’ and many
     others no longer crash or ignore errors if it failed to format the
     error message or decode the filename.  Instead, they keep a
     corresponding error.

   - gh-107810(22): Improve *note DeprecationWarning: 1a3. for uses of
     *note PyType_Spec: 1a71. with metaclasses that have custom
     ‘tp_new’.

   - gh-107249(23): Implement the *note Py_UNUSED: 1a72. macro for
     Windows MSVC compiler.  Patch by Victor Stinner.

   - gh-107226(24): *note PyModule_AddObjectRef(): 60a. is now only
     available in the limited API version 3.10 or later.

   - gh-106320(25): Remove private ‘_PyUnicode_AsString()’ alias to
     *note PyUnicode_AsUTF8(): 424.  It was kept for backward
     compatibility with Python 3.0 - 3.2.  The *note PyUnicode_AsUTF8():
     424. is available since Python 3.3.  The *note
     PyUnicode_AsUTF8String(): 1396. function can be used to keep
     compatibility with Python 3.2 and older.  Patch by Victor Stinner.

   - gh-106572(26): Convert *note PyObject_DelAttr(): 1819. and *note
     PyObject_DelAttrString(): 181a. macros to functions.  Patch by
     Victor Stinner.

   - gh-106307(27): Add *note PyMapping_GetOptionalItem(): 5e8.
     function.

   - gh-106521(28): Add *note PyObject_GetOptionalAttr(): 5ec. and *note
     PyObject_GetOptionalAttrString(): 5ed. functions.

   - gh-106320(29): Remove ‘_PyInterpreterState_Get()’ alias to *note
     PyInterpreterState_Get(): 64c. which was kept for backward
     compatibility with Python 3.8.  Patch by Victor Stinner.

   - gh-106316(30): Remove ‘cpython/pytime.h’ header file: it only
     contained private functions.  Patch by Victor Stinner.

   - gh-106023(31): Remove private ‘_PyObject_FastCall()’ function: use
     ‘PyObject_Vectorcall()’ which is available since Python 3.8 ( PEP
     590(32)).  Patch by Victor Stinner.

   - gh-106168(33): If Python is built in *note debug mode: 50a. or
     *note with assertions: 62d, *note PyTuple_SET_ITEM(): 62e. and
     *note PyList_SET_ITEM(): 62f. now check the index argument with an
     assertion.  If the assertion fails, make sure that the size is set
     before.  Patch by Victor Stinner.

   - gh-106084(34): Remove the old aliases to functions calling
     functions which were kept for backward compatibility with Python
     3.8 provisional API:

        * ‘_PyObject_CallMethodNoArgs()’: use
          ‘PyObject_CallMethodNoArgs()’

        * ‘_PyObject_CallMethodOneArg()’: use
          ‘PyObject_CallMethodOneArg()’

        * ‘_PyObject_CallOneArg()’: use ‘PyObject_CallOneArg()’

        * ‘_PyObject_FastCallDict()’: use ‘PyObject_VectorcallDict()’

        * ‘_PyObject_Vectorcall()’: use ‘PyObject_Vectorcall()’

        * ‘_PyObject_VectorcallMethod()’: use
          ‘PyObject_VectorcallMethod()’

        * ‘_PyVectorcall_Function()’: use ‘PyVectorcall_Function()’

     Just remove the underscore prefix to update your code.  Patch by
     Victor Stinner.

   - gh-106004(35): Adds *note PyDict_GetItemRef(): 5e0. and *note
     PyDict_GetItemStringRef(): 421. functions: similar to *note
     PyDict_GetItemWithError(): 5e1. but returning a *note strong
     reference: 5e2. instead of a *note borrowed reference: 3d7.  Patch
     by Victor Stinner.

   - gh-105927(36): Deprecate the *note PyWeakref_GetObject(): 3dd. and
     *note PyWeakref_GET_OBJECT(): 3de. functions: use the new *note
     PyWeakref_GetRef(): 3df. function instead.  Patch by Victor
     Stinner.

   - gh-105927(37): Add *note PyWeakref_GetRef(): 3df. function: similar
     to *note PyWeakref_GetObject(): 3dd. but returns a *note strong
     reference: 5e2, or ‘NULL’ if the referent is no longer live.  Patch
     by Victor Stinner.

   - gh-105922(38): Add *note PyImport_AddModuleRef(): 5fb.: similar to
     *note PyImport_AddModule(): 5fc, but return a *note strong
     reference: 5e2. instead of a *note borrowed reference: 3d7.  Patch
     by Victor Stinner.

   - gh-105227(39): The new *note PyType_GetDict(): 1a73. provides the
     dictionary for the given type object that is normally exposed by
     ‘cls.__dict__’.  Normally it’s sufficient to use *note tp_dict:
     1a74, but for the static builtin types ‘tp_dict’ is now always
     ‘NULL’.  ‘PyType_GetDict()’ provides the correct dict object
     instead.

   - gh-105375(40): Fix a bug in *note PyErr_WarnExplicit(): 1a75. where
     an exception could end up being overwritten if the API failed
     internally.

   - gh-105603(41): We’ve renamed the new (in 3.12)
     ‘PyInterpreterConfig.own_gil’ to ‘PyInterpreterConfig.gil’ and
     changed the meaning of the value from «bool» to an integer with
     supported values of ‘PyInterpreterConfig_DEFAULT_GIL’,
     ‘PyInterpreterConfig_SHARED_GIL’, and
     ‘PyInterpreterConfig_OWN_GIL’.  The default is «shared».

   - gh-105387(42): In the limited C API version 3.12, *note
     Py_INCREF(): 790. and *note Py_DECREF(): 791. functions are now
     implemented as opaque function calls to hide implementation
     details.  Patch by Victor Stinner.

   - gh-105396(43): Deprecate the *note PyImport_ImportModuleNoBlock():
     3db. function which is just an alias to *note
     PyImport_ImportModule(): 3dc. since Python 3.3.  Patch by Victor
     Stinner.

   - gh-103968(44): *note PyType_FromMetaclass(): 773. now allows
     metaclasses with ‘tp_new’ set to ‘NULL’.

   - gh-105268(45): Remove the old private, undocumented and untested
     ‘_PyGC_FINALIZED()’ macro which was kept for backward compatibility
     with Python 3.8 and older.  Patch by Victor Stinner.

   - gh-105182(46): Remove ‘PyEval_AcquireLock()’ and
     ‘PyEval_ReleaseLock()’ functions, deprecated in Python 3.2.  Patch
     by Victor Stinner.

   - gh-105182(47): Remove ‘PyEval_InitThreads()’ and
     ‘PyEval_ThreadsInitialized()’ functions, deprecated in Python 3.9.
     Patch by Victor Stinner.

   - gh-105145(48): Deprecate old Python initialization functions:

        * *note PySys_ResetWarnOptions(): 3f4.

        * *note Py_GetExecPrefix(): 3e9.

        * *note Py_GetPath(): 3e3.

        * *note Py_GetPrefix(): 3e5.

        * *note Py_GetProgramFullPath(): 3ec.

        * *note Py_GetProgramName(): 3ee.

        * *note Py_GetPythonHome(): 3ef.

     Patch by Victor Stinner.

   - gh-85275(49): ‘PyObject_AsCharBuffer()’, ‘PyObject_AsReadBuffer()’,
     ‘PyObject_CheckReadBuffer()’, and ‘PyObject_AsWriteBuffer()’ are
     removed.  Please migrate to new buffer protocol; *note
     PyObject_GetBuffer(): 63a. and *note PyBuffer_Release(): 63b.

   - gh-105156(50): Deprecate the old ‘Py_UNICODE’ and ‘PY_UNICODE_TYPE’
     types: use directly the ‘wchar_t’ type instead.  Since Python 3.3,
     ‘Py_UNICODE’ and ‘PY_UNICODE_TYPE’ are just aliases to ‘wchar_t’.
     Patch by Victor Stinner.

   - gh-105145(51): Remove the following old functions to configure the
     Python initialization, deprecated in Python 3.11:

        * ‘PySys_AddWarnOptionUnicode()’

        * ‘PySys_AddWarnOption()’

        * ‘PySys_AddXOption()’

        * ‘PySys_HasWarnOptions()’

        * ‘PySys_SetArgvEx()’

        * ‘PySys_SetArgv()’

        * ‘PySys_SetPath()’

        * ‘Py_SetPath()’

        * ‘Py_SetProgramName()’

        * ‘Py_SetPythonHome()’

        * ‘Py_SetStandardStreamEncoding()’

        * ‘_Py_SetProgramFullPath()’

     Patch by Victor Stinner.

   - gh-105107(52): Remove functions deprecated in Python 3.9.

        * ‘PyEval_CallObject()’, ‘PyEval_CallObjectWithKeywords()’: use
          *note PyObject_CallNoArgs(): 63c. and *note PyObject_Call():
          63d. (positional arguments must not be 'NULL') instead.

        * ‘PyEval_CallFunction()’: use *note PyObject_CallFunction():
          63f. instead.

        * ‘PyEval_CallMethod()’: use *note PyObject_CallMethod(): 640.
          instead.

        * ‘PyCFunction_Call()’: use *note PyObject_Call(): 63d. instead.

     Patch by Victor Stinner.

   - gh-105115(53): ‘PyTypeObject.tp_bases’ (and ‘tp_mro’) for builtin
     static types are now shared by all interpreters, whereas in
     3.12-beta1 they were stored on ‘PyInterpreterState’.  Also note
     that now the tuples are immortal objects.

   - gh-105071(54): Add ‘PyUnstable_Exc_PrepReraiseStar’ to the unstable
     C api to expose the implementation of *note except*: 1ac.

   - gh-104922(55): ‘PY_SSIZE_T_CLEAN’ is no longer required to use
     ‘'#'’ formats in APIs like *note PyArg_ParseTuple(): 3c1. and *note
     Py_BuildValue(): 3c2.  They uses ‘Py_ssize_t’ for ‘'#'’ regardless
     ‘PY_SSIZE_T_CLEAN’.

   - gh-104584(56): Add an unstable C API for hooking in an optimizer.
     This is mainly internal, but marked «unstable» to allow third-party
     experimentation.

   - gh-104668(57): Don’t call *note PyOS_InputHook: 7a5. or *note
     PyOS_ReadlineFunctionPointer: 7a6. in subinterpreters, since it’s
     generally difficult to avoid using global state in their registered
     callbacks.  This also avoids situations where extensions may find
     themselves running in a subinterpreter they don’t support (or
     haven’t yet been loaded in).

   - bpo-42327(58): Add *note PyModule_Add(): 609. function: similar to
     *note PyModule_AddObjectRef(): 60a. and *note PyModule_AddObject():
     60b, but always steals a reference to the value.

   - bpo-40309(59): Properly handle trailing spaces before closing
     parenthesis in *note Py_BuildValue(): 3c2. format strings.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/85283

   (2) https://github.com/python/cpython/issues/110289

   (3) https://github.com/python/cpython/issues/110235

   (4) https://github.com/python/cpython/issues/110014

   (5) https://github.com/python/cpython/issues/109521

   (6) https://github.com/python/cpython/issues/108724

   (7) https://github.com/python/cpython/issues/85283

   (8) https://github.com/python/cpython/issues/108867

   (9) https://github.com/python/cpython/issues/108765

   (10) https://github.com/python/cpython/issues/108765

   (11) https://github.com/python/cpython/issues/108765

   (12) https://github.com/python/cpython/issues/108765

   (13) https://github.com/python/cpython/issues/108511

   (14) https://github.com/python/cpython/issues/107073

   (15) https://github.com/python/cpython/issues/108634

   (16) https://github.com/python/cpython/issues/108014

   (17) https://github.com/python/cpython/issues/108314

   (18) https://github.com/python/cpython/issues/108337

   (19) https://github.com/python/cpython/issues/108014

   (20) https://github.com/python/cpython/issues/107916

   (21) https://github.com/python/cpython/issues/107915

   (22) https://github.com/python/cpython/issues/107810

   (23) https://github.com/python/cpython/issues/107249

   (24) https://github.com/python/cpython/issues/107226

   (25) https://github.com/python/cpython/issues/106320

   (26) https://github.com/python/cpython/issues/106572

   (27) https://github.com/python/cpython/issues/106307

   (28) https://github.com/python/cpython/issues/106521

   (29) https://github.com/python/cpython/issues/106320

   (30) https://github.com/python/cpython/issues/106316

   (31) https://github.com/python/cpython/issues/106023

   (32) https://peps.python.org/pep-0590/

   (33) https://github.com/python/cpython/issues/106168

   (34) https://github.com/python/cpython/issues/106084

   (35) https://github.com/python/cpython/issues/106004

   (36) https://github.com/python/cpython/issues/105927

   (37) https://github.com/python/cpython/issues/105927

   (38) https://github.com/python/cpython/issues/105922

   (39) https://github.com/python/cpython/issues/105227

   (40) https://github.com/python/cpython/issues/105375

   (41) https://github.com/python/cpython/issues/105603

   (42) https://github.com/python/cpython/issues/105387

   (43) https://github.com/python/cpython/issues/105396

   (44) https://github.com/python/cpython/issues/103968

   (45) https://github.com/python/cpython/issues/105268

   (46) https://github.com/python/cpython/issues/105182

   (47) https://github.com/python/cpython/issues/105182

   (48) https://github.com/python/cpython/issues/105145

   (49) https://github.com/python/cpython/issues/85275

   (50) https://github.com/python/cpython/issues/105156

   (51) https://github.com/python/cpython/issues/105145

   (52) https://github.com/python/cpython/issues/105107

   (53) https://github.com/python/cpython/issues/105115

   (54) https://github.com/python/cpython/issues/105071

   (55) https://github.com/python/cpython/issues/104922

   (56) https://github.com/python/cpython/issues/104584

   (57) https://github.com/python/cpython/issues/104668

   (58) https://bugs.python.org/issue?@action=redirect&bpo=42327

   (59) https://bugs.python.org/issue?@action=redirect&bpo=40309


File: python.info,  Node: Python 3 12 0 beta 1,  Next: Python 3 12 0 alpha 7,  Prev: Python 3 13 0 alpha 1,  Up: Changelog

1.24.26 Python 3.12.0 beta 1
----------------------------

'Release date: 2023-05-22'

* Menu:

* Security: Security<22>.
* Library: Library<64>.
* Core and Builtins: Core and Builtins<59>.
* Library: Library<65>.
* Core and Builtins: Core and Builtins<60>.
* Library: Library<66>.
* Documentation: Documentation<20>.
* Tests: Tests<20>.
* Build: Build<23>.
* Windows: Windows<21>.
* macOS: macOS<14>.
* IDLE: IDLE<14>.
* Tools/Demos: Tools/Demos<20>.
* C API: C API<23>.


File: python.info,  Node: Security<22>,  Next: Library<64>,  Up: Python 3 12 0 beta 1

1.24.26.1 Security
..................

   - gh-99889(1): Fixed a security in flaw in ‘uu.decode()’ that could
     allow for directory traversal based on the input if no ‘out_file’
     was specified.

   - gh-104049(2): Do not expose the local on-disk location in directory
     indexes produced by ‘http.client.SimpleHTTPRequestHandler’.

   - gh-99108(3): Upgrade built-in *note hashlib: 6c. SHA3
     implementation to a verified implementation from the ‘HACL*’
     project.  Used when OpenSSL is not present or lacks SHA3.

   - gh-102153(4): *note urllib.parse.urlsplit(): f3c. now strips
     leading C0 control and space characters following the specification
     for URLs defined by WHATWG in response to CVE 2023-24329(5).  Patch
     by Illia Volochii.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99889

   (2) https://github.com/python/cpython/issues/104049

   (3) https://github.com/python/cpython/issues/99108

   (4) https://github.com/python/cpython/issues/102153

   (5) https://www.cve.org/CVERecord?id=CVE-2023-24329


File: python.info,  Node: Library<64>,  Next: Core and Builtins<59>,  Prev: Security<22>,  Up: Python 3 12 0 beta 1

1.24.26.2 Library
.................

   - gh-102856(1): Implement PEP 701 changes in the *note tokenize: 101.
     module.  Patch by Marta Gómez Macías and Pablo Galindo Salgado

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102856


File: python.info,  Node: Core and Builtins<59>,  Next: Library<65>,  Prev: Library<64>,  Up: Python 3 12 0 beta 1

1.24.26.3 Core and Builtins
...........................

   - gh-104615(1): Fix wrong ordering of assignments in code like ‘a, a
     = x, y’.  Contributed by Carl Meyer.

   - gh-104572(2): Improve syntax error message for invalid constructs
     in PEP 695(3) contexts and in annotations when ‘from __future__
     import annotations’ is active.

   - gh-104482(4): Fix three error handling bugs in ast.c’s validation
     of pattern matching statements.

   - gh-102818(5): Do not add a frame to the traceback in the
     ‘sys.setprofile’ and ‘sys.settrace’ trampoline functions.  This
     ensures that frames are not duplicated if an exception is raised in
     the callback function, and ensures that frames are not omitted if a
     C callback is used and that does not add the frame.

   - gh-104405(6): Fix an issue where some *note bytecode: 4ab.
     instructions could ignore PEP 523(7) when «inlining» calls.

   - gh-103082(8): Change behavior of ‘sys.monitoring.events.LINE’
     events in ‘sys.monitoring’: Line events now occur when a new line
     is reached dynamically, instead of using a static approximation, as
     before.  This makes the behavior very similar to that of «line»
     events in ‘sys.settrace’.  This should ease porting of tools from
     3.11 to 3.12.

   - gh-104263(9): Fix ‘float("nan")’ to produce a quiet NaN on
     platforms (like MIPS) where the meaning of the signalling / quiet
     bit is inverted from its usual meaning.  Also introduce a new macro
     ‘Py_INFINITY’ matching C99’s ‘INFINITY’, and refactor internals to
     rely on C99’s ‘NAN’ and ‘INFINITY’ macros instead of hard-coding
     bit patterns for infinities and NaNs.  Thanks Sebastian Berg.

   - gh-99113(10): Multi-phase init extension modules may now indicate
     that they support running in subinterpreters that have their own
     GIL. This is done by using ‘Py_MOD_PER_INTERPRETER_GIL_SUPPORTED’
     as the value for the ‘Py_mod_multiple_interpreters’ module def
     slot.  Otherwise the module, by default, cannot be imported in such
     subinterpreters.  (This does not affect the main interpreter or
     subinterpreters that do not have their own GIL.) In addition to the
     isolation that multi-phase init already normally requires, support
     for per-interpreter GIL involves one additional constraint:
     thread-safety.  If the module has external (linked) dependencies
     and those libraries have any state that isn’t thread-safe then the
     module must do the additional work to add thread-safety.  This
     should be an uncommon case.

   - gh-99113(11): The GIL is now (optionally) per-interpreter.  This is
     the fundamental change for PEP 684.  This is all made possible by
     virtue of the isolated state of each interpreter in the process.
     The behavior of the main interpreter remains unchanged.  Likewise,
     interpreters created using ‘Py_NewInterpreter()’ are not affected.
     To get an interpreter with its own GIL, call
     ‘Py_NewInterpreterFromConfig()’.

   - gh-104108(12): Multi-phase init extension modules may now indicate
     whether or not they actually support multiple interpreters.  By
     default such modules are expected to support use in multiple
     interpreters.  In the uncommon case that one does not, it may use
     the new ‘Py_mod_multiple_interpreters’ module def slot.  A value of
     ‘0’ means the module does not support them.  ‘1’ means it does.
     The default is ‘1’.

   - gh-104142(13): Fix an issue where *note list: 24d. or *note tuple:
     614. repetition could fail to respect PEP 683(14).

   - gh-104078(15): Improve the performance of *note
     PyObject_HasAttrString(): 61e.

   - gh-104066(16): Improve the performance of *note hasattr(): 6fa. for
     module objects with a missing attribute.

   - gh-104028(17): Reduce object creation while calling callback
     function from gc.  Patch by Donghee Na.

   - gh-104018(18): Disallow the «z» format specifier in %-format of
     bytes objects.

   - gh-102213(19): Fix performance loss when accessing an object’s
     attributes with ‘__getattr__’ defined.

   - gh-103895(20): Improve handling of edge cases in showing
     ‘Exception.__notes__’.  Ensures that the messages always end with a
     newline and that string/bytes are not exploded over multiple lines.
     Patch by Carey Metcalfe.

   - gh-103907(21): Don’t modify the refcounts of known immortal objects
     (*note True: e09, *note False: d2d, and *note None: 886.) in the
     main interpreter loop.

   - gh-103899(22): Provide a helpful hint in the *note TypeError: 198.
     message when accidentally calling a *note module: 19c6. object that
     has a callable attribute of the same name (such as *note dis.dis():
     205. or *note datetime.datetime: 4e3.).

   - gh-103845(23): Remove both line and instruction instrumentation
     before adding new ones for monitoring, to avoid newly added
     instrumentation being removed immediately.

   - gh-103763(24): Implement PEP 695(25), adding syntactic support for
     generic classes, generic functions, and type aliases.

     A new ‘type X = ...’ syntax is added for type aliases, which
     resolves at runtime to an instance of the new class
     ‘typing.TypeAliasType’.  The value is lazily evaluated and is
     accessible through the ‘.__value__’ attribute.  This is implemented
     as a new AST node ‘ast.TypeAlias’.

     New syntax (‘class X[T]: ...’, ‘def func[T](): ...’) is added for
     defining generic functions and classes.  This is implemented as a
     new ‘type_params’ attribute on the AST nodes for classes and
     functions.  This node holds instances of the new AST classes
     ‘ast.TypeVar’, ‘ast.ParamSpec’, and ‘ast.TypeVarTuple’.

     ‘typing.TypeVar’, ‘typing.ParamSpec’, ‘typing.ParamSpecArgs’,
     ‘typing.ParamSpecKwargs’, ‘typing.TypeVarTuple’, and
     ‘typing.Generic’ are now implemented in C rather than Python.

     There are new bytecode instructions ‘LOAD_LOCALS’,
     ‘LOAD_CLASSDICT_OR_GLOBAL’, and ‘LOAD_CLASSDICT_OR_DEREF’ to
     support correct resolution of names in class namespaces.

     Patch by Eric Traut, Larry Hastings, and Jelle Zijlstra.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104615

   (2) https://github.com/python/cpython/issues/104572

   (3) https://peps.python.org/pep-0695/

   (4) https://github.com/python/cpython/issues/104482

   (5) https://github.com/python/cpython/issues/102818

   (6) https://github.com/python/cpython/issues/104405

   (7) https://peps.python.org/pep-0523/

   (8) https://github.com/python/cpython/issues/103082

   (9) https://github.com/python/cpython/issues/104263

   (10) https://github.com/python/cpython/issues/99113

   (11) https://github.com/python/cpython/issues/99113

   (12) https://github.com/python/cpython/issues/104108

   (13) https://github.com/python/cpython/issues/104142

   (14) https://peps.python.org/pep-0683/

   (15) https://github.com/python/cpython/issues/104078

   (16) https://github.com/python/cpython/issues/104066

   (17) https://github.com/python/cpython/issues/104028

   (18) https://github.com/python/cpython/issues/104018

   (19) https://github.com/python/cpython/issues/102213

   (20) https://github.com/python/cpython/issues/103895

   (21) https://github.com/python/cpython/issues/103907

   (22) https://github.com/python/cpython/issues/103899

   (23) https://github.com/python/cpython/issues/103845

   (24) https://github.com/python/cpython/issues/103763

   (25) https://peps.python.org/pep-0695/


File: python.info,  Node: Library<65>,  Next: Core and Builtins<60>,  Prev: Core and Builtins<59>,  Up: Python 3 12 0 beta 1

1.24.26.4 Library
.................

   - gh-103801(1): Adds three minor linting fixes to the wasm module
     caught that were caught by ruff.

   - gh-103793(2): Optimized asyncio Task creation by deferring
     expensive string formatting (task name generation) from Task
     creation to the first time ‘get_name’ is called.  This makes
     asyncio benchmarks up to 5% faster.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/103801

   (2) https://github.com/python/cpython/issues/103793


File: python.info,  Node: Core and Builtins<60>,  Next: Library<66>,  Prev: Library<65>,  Up: Python 3 12 0 beta 1

1.24.26.5 Core and Builtins
...........................

   - gh-102310(1): Change the error range for invalid bytes literals.

   - gh-103590(2): Do not wrap a single exception raised from a
     ‘try-except*’ construct in an *note ExceptionGroup: 4d3.

   - gh-103650(3): Change the perf map format to remove the “0x” prefix
     from the addresses

   - gh-102856(4): Implement the required C tokenizer changes for PEP
     701.  Patch by Pablo Galindo Salgado, Lysandros Nikolaou, Batuhan
     Taskaya, Marta Gómez Macías and sunmy2019.

   - gh-100530(5): Clarify the error message raised when the called part
     of a class pattern isn’t actually a class.

   - gh-101517(6): Fix bug in line numbers of instructions emitted for
     *note except*: 1ac.

   - gh-103492(7): Clarify *note SyntaxWarning: 1ae. with literal ‘is’
     comparison by specifying which literal is problematic, since
     comparisons using ‘is’ with e.g.  ‘None’ and bool literals are
     idiomatic.

   - gh-87729(8): Add *note LOAD_SUPER_ATTR: 703. (and a specialization
     for ‘super().method()’) to speed up ‘super().method()’ and
     ‘super().attr’.  This makes ‘super().method()’ roughly 2.3x faster
     and brings it within 20% of the performance of a simple method
     call.  Patch by Vladimir Matveev and Carl Meyer.

   - gh-103488(9): Change the internal offset distinguishing yield and
     return target addresses, so that the instruction pointer is correct
     for exception handling and other stack unwinding.

   - gh-82012(10): The bitwise inversion operator (‘~’) on bool is
     deprecated.  It returns the bitwise inversion of the underlying
     ‘int’ representation such that ‘bool(~True) == True’, which can be
     confusing.  Use ‘not’ for logical negation of bools.  In the rare
     case that you really need the bitwise inversion of the underlying
     ‘int’, convert to int explicitly ‘~int(x)’.

   - gh-77757(11): Exceptions raised in a typeobject’s ‘__set_name__’
     method are no longer wrapped by a *note RuntimeError: 244.  Context
     information is added to the exception as a PEP 678(12) note.

   - gh-103333(13): *note AttributeError: 5f0. now retains the ‘name’
     attribute when pickled and unpickled.

   - gh-103242(14): Migrate *note set_ecdh_curve(): 134b. method not to
     use deprecated OpenSSL APIs.  Patch by Donghee Na.

   - gh-103323(15): We’ve replaced our use of
     ‘_PyRuntime.tstate_current’ with a thread-local variable.  This is
     a fairly low-level implementation detail, and there should be no
     change in behavior.

   - gh-84436(16): The implementation of PEP-683 which adds Immortal
     Objects by using a fixed reference count that skips reference
     counting to make objects truly immutable.

   - gh-102700(17): Allow built-in modules to be submodules.  This
     allows submodules to be statically linked into a CPython binary.

   - gh-103082(18): Implement PEP 669(19) Low Impact Monitoring for
     CPython.

   - gh-88691(20): Reduce the number of inline *note CACHE: 909. entries
     for *note CALL: 916.

   - gh-102500(21): Make the buffer protocol accessible in Python code
     using the new ‘__buffer__’ and ‘__release_buffer__’ magic methods.
     See PEP 688(22) for details.  Patch by Jelle Zijlstra.

   - gh-97933(23): PEP 709(24): inline list, dict and set comprehensions
     to improve performance and reduce bytecode size.

   - gh-99184(25): Bypass instance attribute access of ‘__name__’ in
     ‘repr’ of *note weakref.ref: 11f2.

   - gh-98003(26): Complex function calls are now faster and consume no
     C stack space.

   - bpo-39610(27): ‘len()’ for 0-dimensional *note memoryview: 165.
     objects (such as ‘memoryview(ctypes.c_uint8(42))’) now raises a
     *note TypeError: 198.  Previously this returned ‘1’, which was not
     consistent with ‘mem_0d[0]’ raising an *note IndexError: 173c.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102310

   (2) https://github.com/python/cpython/issues/103590

   (3) https://github.com/python/cpython/issues/103650

   (4) https://github.com/python/cpython/issues/102856

   (5) https://github.com/python/cpython/issues/100530

   (6) https://github.com/python/cpython/issues/101517

   (7) https://github.com/python/cpython/issues/103492

   (8) https://github.com/python/cpython/issues/87729

   (9) https://github.com/python/cpython/issues/103488

   (10) https://github.com/python/cpython/issues/82012

   (11) https://github.com/python/cpython/issues/77757

   (12) https://peps.python.org/pep-0678/

   (13) https://github.com/python/cpython/issues/103333

   (14) https://github.com/python/cpython/issues/103242

   (15) https://github.com/python/cpython/issues/103323

   (16) https://github.com/python/cpython/issues/84436

   (17) https://github.com/python/cpython/issues/102700

   (18) https://github.com/python/cpython/issues/103082

   (19) https://peps.python.org/pep-0669/

   (20) https://github.com/python/cpython/issues/88691

   (21) https://github.com/python/cpython/issues/102500

   (22) https://peps.python.org/pep-0688/

   (23) https://github.com/python/cpython/issues/97933

   (24) https://peps.python.org/pep-0709/

   (25) https://github.com/python/cpython/issues/99184

   (26) https://github.com/python/cpython/issues/98003

   (27) https://bugs.python.org/issue?@action=redirect&bpo=39610


File: python.info,  Node: Library<66>,  Next: Documentation<20>,  Prev: Core and Builtins<60>,  Up: Python 3 12 0 beta 1

1.24.26.6 Library
.................

   - bpo-31821(1): Fix ‘pause_reading()’ to work when called from
     ‘connection_made()’ in *note asyncio: b.

   - gh-104600(2): *note functools.update_wrapper(): 1224. now sets the
     ‘__type_params__’ attribute (added by PEP 695(3)).

   - gh-104340(4): When an ‘asyncio’ pipe protocol loses its connection
     due to an error, and the caller doesn’t await ‘wait_closed()’ on
     the corresponding ‘StreamWriter’, don’t log a warning about an
     exception that was never retrieved.  After all, according to the
     ‘StreamWriter.close()’ docs, the ‘wait_closed()’ call is optional
     («not mandatory»).

   - gh-104555(5): Fix issue where an *note issubclass(): 9c6. check
     comparing a class ‘X’ against a *note runtime-checkable protocol:
     675. ‘Y’ with non-callable members would not cause *note TypeError:
     198. to be raised if an *note isinstance(): 2ad. call had
     previously been made comparing an instance of ‘X’ to ‘Y’.  This
     issue was present in edge cases on Python 3.11, but became more
     prominent in 3.12 due to some unrelated changes that were made to
     runtime-checkable protocols.  Patch by Alex Waygood.

   - gh-104372(6): Refactored the ‘_posixsubprocess’ internals to avoid
     Python C API usage between fork and exec when marking ‘pass_fds=’
     file descriptors inheritable.

   - gh-104484(7): Added 'case_sensitive' argument to *note
     pathlib.PurePath.match(): 6d4.

   - gh-75367(8): Fix data descriptor detection in *note
     inspect.getattr_static(): 6bd.

   - gh-104536(9): Fix a race condition in the internal
     ‘multiprocessing.process’ cleanup logic that could manifest as an
     unintended ‘AttributeError’ when calling ‘process.close()’.

   - gh-103857(10): Update datetime deprecations” stracktrace to point
     to the calling line

   - gh-101520(11): Move the core functionality of the ‘tracemalloc’
     module in the ‘Python/’ folder, leaving just the module wrapper in
     ‘Modules/’.

   - gh-104392(12): Remove undocumented and unused ‘_paramspec_tvars’
     attribute from some classes in *note typing: 10a.

   - gh-102613(13): Fix issue where *note pathlib.Path.glob(): 538.
     raised *note RecursionError: f6a. when walking deep directory
     trees.

   - gh-103000(14): Improve performance of *note dataclasses.asdict():
     1a7d. for the common case where 'dict_factory' is ‘dict’.  Patch by
     David C Ellis.

   - gh-104301(15): Allow leading whitespace in disambiguated statements
     in *note pdb: aa.

   - gh-104139(16): Teach ‘urllib.parse.unsplit()’ to retain the ‘"//"’
     when assembling ‘itms-services://?action=generate-bugs’ style Apple
     Platform Deployment(17) URLs.

   - gh-104307(18): *note socket.getnameinfo(): 1a22. now releases the
     GIL while contacting the DNS server

   - gh-104310(19): Users may now use
     ‘importlib.util.allowing_all_extensions()’ (a context manager) to
     temporarily disable the strict compatibility checks for importing
     extension modules in subinterpreters.

   - gh-87695(20): Fix issue where *note pathlib.Path.glob(): 538.
     raised *note OSError: 2c0. when it encountered a symlink to an
     overly long path.

   - gh-104265(21): Prevent possible crash by disallowing instantiation
     of the ‘_csv.Reader’ and ‘_csv.Writer’ types.  The regression was
     introduced in 3.10.0a4 with PR 23224 (bpo-14935(22)).  Patch by
     Radislav Chugunov.

   - gh-102613(23): Improve performance of *note pathlib.Path.glob():
     538. when expanding recursive wildcards (»‘**’») by merging
     adjacent wildcards and de-duplicating results only when necessary.

   - gh-65772(24): Remove unneeded comments and code in turtle.py.

   - gh-90208(25): Fixed issue where *note pathlib.Path.glob(): 538.
     returned incomplete results when it encountered a *note
     PermissionError: f40.  This method now suppresses all *note
     OSError: 2c0. exceptions, except those raised from calling *note
     is_dir(): 53b. on the top-level path.

   - gh-104144(26): Optimize *note asyncio.TaskGroup: 4d2. when using
     *note asyncio.eager_task_factory(): 6a3.  Skip scheduling a done
     callback if a TaskGroup task completes eagerly.

   - gh-104144(27): Optimize *note asyncio.gather(): 814. when using
     *note asyncio.eager_task_factory(): 6a3. to complete eagerly if all
     fututres completed eagerly.  Avoid scheduling done callbacks for
     futures that complete eagerly.

   - gh-104114(28): Fix issue where *note pathlib.Path.glob(): 538.
     returns paths using the case of non-wildcard segments for
     corresponding path segments, rather than the real filesystem case.

   - gh-104104(29): Improve performance of *note pathlib.Path.glob():
     538. by using *note re.IGNORECASE: 1a7e. to implement
     case-insensitive matching.

   - gh-104102(30): Improve performance of *note pathlib.Path.glob():
     538. when evaluating patterns that contain ‘'../'’ segments.

   - gh-103822(31): Update the return type of ‘weekday’ to the newly
     added Day attribute

   - gh-103629(32): Update the ‘repr’ of *note typing.Unpack: 198e.
     according to PEP 692(33).

   - gh-103963(34): Make *note dis: 3c. display the names of the args
     for ‘CALL_INTRINSIC_*’.

   - gh-104035(35): Do not ignore user-defined ‘__getstate__’ and
     ‘__setstate__’ methods for slotted frozen dataclasses.

   - gh-103987(36): In *note mmap: 94, fix several bugs that could lead
     to access to memory-mapped files after they have been invalidated.

   - gh-103977(37): Improve import time of *note platform: af. module.

   - gh-88773(38): Added *note turtle.teleport(): 1a7f. to the *note
     turtle: 107. module to move a turtle to a new point without tracing
     a line, visible or invisible.  Patch by Liam Gersten.

   - gh-103935(39): Use *note io.open_code(): 1a80. for files to be
     executed instead of raw *note open(): 316.

   - gh-68968(40): Fixed garbled output of *note assertEqual(): 74d.
     when an input lacks final newline.

   - gh-100370(41): Fix potential *note OverflowError: a83. in *note
     sqlite3.Connection.blobopen(): 892. for 32-bit builds.  Patch by
     Erlend E. Aasland.

   - gh-102628(42): Substitute CTRL-D with CTRL-Z in *note sqlite3: d4.
     CLI banner when running on Windows.

   - gh-103636(43): Module-level attributes ‘January’ and ‘February’ are
     deprecated from *note calendar: 15.

   - gh-103583(44): Isolate ‘_multibytecodec’ and codecs extension
     modules.  Patches by Erlend E. Aasland.

   - gh-103848(45): Add checks to ensure that ‘[’ bracketed ‘]’ hosts
     found by *note urllib.parse.urlsplit(): f3c. are of IPv6 or
     IPvFuture format.

   - gh-103872(46): Update the bundled copy of pip to version 23.1.2.

   - gh-99944(47): Make *note dis: 3c. display the value of oparg of
     ‘KW_NAMES’.

   - gh-74940(48): The C.UTF-8 locale is no longer converted to
     en_US.UTF-8, enabling the use of UTF-8 encoding on systems which
     have no locales installed.

   - gh-103861(49): Fix ‘zipfile.Zipfile’ creating invalid zip files
     when ‘force_zip64’ was used to add files to them.  Patch by Carey
     Metcalfe.

   - gh-103857(50): Deprecated *note datetime.datetime.utcnow(): 351.
     and *note datetime.datetime.utcfromtimestamp(): 352.  (Patch by
     Paul Ganssle)

   - gh-103839(51): Avoid compilation error due to tommath.h not being
     found when building Tkinter against Tcl 8.7 built with bundled
     libtommath.

   - gh-103791(52): *note contextlib.suppress: 112a. now supports
     suppressing exceptions raised as part of an *note ExceptionGroup:
     4d3.  If other exceptions exist on the group, they are re-raised in
     a group that does not contain the suppressed exceptions.

   - gh-90750(53): Use *note datetime.datetime.fromisocalendar(): be2.
     in the implementation of *note datetime.datetime.strptime(): 1938,
     which should now accept only valid ISO dates.  (Patch by Paul
     Ganssle)

   - gh-103685(54): Prepare ‘tkinter.Menu.index()’ for Tk 8.7 so that it
     does not raise ‘TclError: expected integer but got ""’ when it
     should return ‘None’.

   - gh-81403(55): *note urllib.request.CacheFTPHandler: 1a81. no longer
     raises ‘URLError’ if a cached FTP instance is reused.  ftplib’s
     endtransfer method calls voidresp to drain the connection to handle
     FTP instance reuse properly.

   - gh-103699(56): Add ‘__orig_bases__’ to non-generic TypedDicts,
     call-based TypedDicts, and call-based NamedTuples.  Other
     TypedDicts and NamedTuples already had the attribute.

   - gh-103693(57): Add convenience variable feature to *note pdb: aa.

   - gh-92248(58): Deprecate ‘type’, ‘choices’, and ‘metavar’ parameters
     of ‘argparse.BooleanOptionalAction’.

   - gh-89415(59): Add *note socket: d1. constants for source-specific
     multicast.  Patch by Reese Hyde.

   - gh-103673(60): *note socketserver: d2. gains
     ‘ForkingUnixStreamServer’ and ‘ForkingUnixDatagramServer’ classes.
     Patch by Jay Berry.

   - gh-103636(61): Added Enum for months and days in the calendar
     module.

   - gh-84976(62): Create a new ‘Lib/_pydatetime.py’ file that defines
     the Python version of the ‘datetime’ module, and make ‘datetime’
     import the contents of the new library only if the C implementation
     is missing.  Currently, the full Python implementation is defined
     and then deleted if the C implementation is not available, slowing
     down ‘import datetime’ unnecessarily.

   - gh-103596(63): Attributes/methods are no longer shadowed by
     same-named enum members, although they may be shadowed by
     enum.property’s.

   - gh-103584(64): Updated ‘importlib.metadata’ with changes from
     ‘importlib_metadata’ 5.2 through 6.5.0, including: Support
     ‘installed-files.txt’ for ‘Distribution.files’ when present.
     ‘PackageMetadata’ now stipulates an additional ‘get’ method
     allowing for easy querying of metadata keys that may not be
     present.  ‘packages_distributions’ now honors packages and modules
     with Python modules that not ‘.py’ sources (e.g.  ‘.pyc’, ‘.so’).
     Expand protocol for ‘PackageMetadata.get_all’ to match the upstream
     implementation of ‘email.message.Message.get_all’ in
     python/typeshed#9620.  Deprecated use of ‘Distribution’ without
     defining abstract methods.  Deprecated expectation that
     ‘PackageMetadata.__getitem__’ will return ‘None’ for missing keys.
     In the future, it will raise a ‘KeyError’.

   - gh-103578(65): Fixed a bug where *note pdb: aa. crashes when
     reading source file with different encoding by replacing *note
     io.open(): 741. with *note io.open_code(): 1a80.  The new method
     would also call into the hook set by *note
     PyFile_SetOpenCodeHook(): 1a82.

   - gh-103556(66): Now creating *note inspect.Signature: 4e4. objects
     with positional-only parameter with a default followed by a
     positional-or-keyword parameter without one is impossible.

   - gh-103559(67): Update the bundled copy of pip to version 23.1.1.

   - gh-103548(68): Improve performance of *note
     pathlib.Path.absolute(): 1a0e. and *note cwd(): 1a83. by joining
     paths only when necessary.  Also improve performance of *note
     pathlib.PurePath.is_absolute(): 1a84. on Posix by skipping path
     parsing and normalization.

   - gh-103538(69): Remove ‘_tkinter’ module code guarded by definition
     of the ‘TK_AQUA’ macro which was only needed for Tk 8.4.7 or
     earlier and was never actually defined by any build system or
     documented for manual use.

   - gh-103533(70): Update *note cProfile: 2b. to use PEP 669 API

   - gh-103525(71): Fix misleading exception message when mixed ‘str’
     and ‘bytes’ arguments are supplied to *note pathlib.PurePath: 6ce.
     and *note Path: 266.

   - gh-103489(72): Add *note getconfig(): 6e1. and *note setconfig():
     6e2. to *note Connection: 54e. to make configuration changes to a
     database connection.  Patch by Erlend E. Aasland.

   - gh-103365(73): Set default Flag boundary to ‘STRICT’ and fix
     bitwise operations.

   - gh-103472(74): Avoid a potential *note ResourceWarning: 54d. in
     *note http.client.HTTPConnection: d37. by closing the proxy /
     tunnel’s CONNECT response explicitly.

   - gh-103462(75): Fixed an issue with using *note writelines(): 17b1.
     in *note asyncio: b. to send very large payloads that exceed the
     amount of data that can be written in one call to *note
     socket.socket.send(): fa9. or *note socket.socket.sendmsg(): 6a2,
     resulting in the remaining buffer being left unwritten.

   - gh-103449(76): Fix a bug in doc string generation in *note
     dataclasses.dataclass(): 4e2.

   - gh-103092(77): Isolate ‘_collections’ (apply PEP 687(78)).  Patch
     by Erlend E. Aasland.

   - gh-103357(79): Added support for *note logging.Formatter: 169e.
     ‘defaults’ parameter to *note logging.config.dictConfig(): 13b8.
     and *note logging.config.fileConfig(): d4a.  Patch by Bar Harel.

   - gh-103092(80): Adapt the *note winreg: 11c. extension module to PEP
     687(81).

   - gh-74690(82): The performance of *note isinstance(): 2ad. checks
     against *note runtime-checkable protocols: 675. has been
     considerably improved for protocols that only have a few members.
     To achieve this improvement, several internal implementation
     details of the *note typing: 10a. module have been refactored,
     including ‘typing._ProtocolMeta.__instancecheck__’,
     ‘typing._is_callable_members_only’, and
     ‘typing._get_protocol_attrs’.  Patches by Alex Waygood.

   - gh-74690(83): The members of a runtime-checkable protocol are now
     considered «frozen» at runtime as soon as the class has been
     created.  See *note «What’s new in Python 3.12»: 6f9. for more
     details.

   - gh-103256(84): Fixed a bug that caused *note hmac: 6e. to raise an
     exception when the requested hash algorithm was not available in
     OpenSSL despite being available separately as part of ‘hashlib’
     itself.  It now falls back properly to the built-in.  This could
     happen when, for example, your OpenSSL does not include SHA3
     support and you want to compute ‘hmac.digest(b'K', b'M',
     'sha3_256')’.

   - gh-102778(85): Support ‘sys.last_exc’ in *note idlelib: 77.

   - gh-103285(86): Improve performance of *note
     ast.get_source_segment(): bcd.

   - gh-103225(87): Fix a bug in *note pdb: aa. when displaying line
     numbers of module-level source code.

   - gh-103092(88): Adapt the *note msvcrt: 97. extension module to PEP
     687(89).

   - gh-103092(90): Adapt the *note winsound: 11d. extension module to
     PEP 687(91).

   - gh-93910(92): Remove deprecation of enum ‘member.member’ access.

   - gh-102978(93): Fixes *note unittest.mock.patch(): 1094. not
     enforcing function signatures for methods decorated with
     ‘@classmethod’ or ‘@staticmethod’ when patch is called with
     ‘autospec=True’.

   - gh-103092(94): Isolate ‘_socket’ (apply PEP 687(95)).  Patch by
     Erlend E. Aasland.

   - gh-100479(96): Add *note pathlib.PurePath.with_segments(): 6cf,
     which creates a path object from arguments.  This method is called
     whenever a derivative path is created, such as from *note
     pathlib.PurePath.parent: 1a85.  Subclasses may override this method
     to share information between path objects.

   - gh-103220(97): Fix issue where *note os.path.join(): 1991. added a
     slash when joining onto an incomplete UNC drive with a trailing
     slash on Windows.

   - gh-103204(98): Fixes *note http.server: 76. accepting HTTP requests
     with HTTP version numbers preceded by “+”, or “-”, or with
     digit-separating “_” characters.  The length of the version numbers
     is also constrained.

   - gh-75586(99): Fix various Windows-specific issues with
     ‘shutil.which’.

   - gh-103193(100): Improve performance of *note
     inspect.getattr_static(): 6bd.  Patch by Alex Waygood.

   - gh-103176(101): *note sys._current_exceptions(): 6ea. now returns a
     mapping from thread-id to an exception instance, rather than to a
     ‘(typ, exc, tb)’ tuple.

   - gh-103143(102): Polish the help messages and docstrings of *note
     pdb: aa.

   - gh-103015(103): Add 'entrypoint' keyword-only parameter to *note
     sqlite3.Connection.load_extension(): 6e0, for overriding the SQLite
     extension entry point.  Patch by Erlend E. Aasland.

   - gh-103000(104): Improve performance of *note dataclasses.astuple():
     1a86. and *note dataclasses.asdict(): 1a7d. in cases where the
     contents are common Python types.

   - gh-102953(105): The extraction methods in *note tarfile: e4, and
     *note shutil.unpack_archive(): 697, have a new a 'filter' argument
     that allows limiting tar features than may be surprising or
     dangerous, such as creating files outside the destination
     directory.  See *note Extraction filters: 698. for details.

   - gh-97696(106): Implemented an eager task factory in asyncio.  When
     used as a task factory on an event loop, it performs eager
     execution of coroutines.  Coroutines that are able to complete
     synchronously (e.g.  return or raise without blocking) are returned
     immediately as a finished task, and the task is never scheduled to
     the event loop.  If the coroutine blocks, the (pending) task is
     scheduled and returned.

   - gh-81079(107): Add 'case_sensitive' keyword-only argument to *note
     pathlib.Path.glob(): 538. and *note rglob(): 539.

   - gh-101819(108): Isolate the *note io: 83. extension module by
     applying PEP 687(109).  Patch by Kumar Aditya, Victor Stinner, and
     Erlend E. Aasland.

   - gh-91896(110): Deprecate *note collections.abc.ByteString: 342.

   - gh-101362(111): Speed up *note pathlib.Path: 266. construction by
     omitting the path anchor from the internal list of path parts.

   - gh-102114(112): Functions in the *note dis: 3c. module that accept
     a source code string as argument now print a more concise traceback
     when the string contains a syntax or indentation error.

   - gh-62432(113): The *note unittest: 10c. runner will now exit with
     status code 5 if no tests were run.  It is common for test runner
     misconfiguration to fail to find any tests, this should be an
     error.

   - gh-78079(114): Fix incorrect normalization of UNC device path
     roots, and partial UNC share path roots, in *note pathlib.PurePath:
     6ce.  Pathlib no longer appends a trailing slash to such paths.

   - gh-85984(115): Add *note tty.cfmakeraw(): 1a2a. and *note
     tty.cfmakecbreak(): 19de. to *note tty: 106. and modernize, the
     behavior of *note tty.setraw(): 1a29. and *note tty.setcbreak():
     19dd. to use POSIX.1-2017 Chapter 11 «General Terminal Interface»
     flag masks by default.

   - gh-101688(116): Implement *note types.get_original_bases(): 6f6. to
     provide further introspection for types.

   - gh-101640(117): *note argparse.ArgumentParser: 1bd. now catches
     errors when writing messages, such as when *note sys.stderr: b35.
     is ‘None’.  Patch by Oleg Iarygin.

   - gh-83861(118): Fix datetime.astimezone method return value when
     invoked on a naive datetime instance that represents local time
     falling in a timezone transition gap.  PEP 495 requires that
     instances with fold=1 produce earlier times than those with fold=0
     in this case.

   - gh-89550(119): Decrease execution time of some *note gzip: 6b. file
     writes by 15% by adding more appropriate buffering.

   - gh-95299(120): Remove the bundled setuptools wheel from
     ‘ensurepip’, and stop installing setuptools in environments created
     by ‘venv’.

   - gh-99353(121): Respect the *note http.client.HTTPConnection: d37.
     ‘.debuglevel’ flag in ‘urllib.request.AbstractHTTPHandler’ when its
     constructor parameter ‘debuglevel’ is not set.  And do the same for
     ‘*HTTPS*’.

   - gh-98040(122): Remove the long-deprecated ‘imp’ module.

   - gh-97850(123): Deprecate ‘pkgutil.find_loader()’ and
     ‘pkgutil.get_loader()’ in favor of *note
     importlib.util.find_spec(): 5af.

   - gh-94473(124): Flatten arguments in ‘tkinter.Canvas.coords()’.  It
     now accepts not only ‘x1, y1, x2, y2, ...’ and ‘[x1, y1, x2, y2,
     ...]’, but also ‘(x1, y1), (x2, y2), ...’ and ‘[(x1, y1), (x2, y2),
     ...]’.

   - gh-98040(125): Remove more deprecated importlib APIs:
     ‘find_loader()’, ‘find_module()’, ‘importlib.abc.Finder’,
     ‘pkgutil.ImpImporter’, ‘pkgutil.ImpLoader’.

   - gh-96522(126): Fix potential deadlock in pty.spawn()

   - gh-96534(127): Support divert(4) added in FreeBSD 14.

   - gh-87474(128): Fix potential file descriptor leaks in *note
     subprocess.Popen: 4b8.

   - gh-94906(129): Support multiple steps in *note math.nextafter():
     6c1.  Patch by Shantanu Jain and Matthias Gorgens.

   - gh-51574(130): Make *note tempfile.mkdtemp(): 52e. return absolute
     paths when its 'dir' parameter is relative.

   - gh-94518(131): Convert private ‘_posixsubprocess.fork_exec()’ to
     use Argument Clinic.

   - gh-92184(132): When creating zip files using *note zipfile: 137,
     ‘os.altsep’, if not ‘None’, will always be treated as a path
     separator even when it is not ‘/’.  Patch by Carey Metcalfe.

   - bpo-46797(133): Deprecation warnings are now emitted for ‘ast.Num’,
     ‘ast.Bytes’, ‘ast.Str’, ‘ast.NameConstant’ and ‘ast.Ellipsis’.
     These have been documented as deprecated since Python 3.8, and will
     be removed in Python 3.14.

   - bpo-44844(134): Enables *note webbrowser: 11b. to detect and launch
     Microsoft Edge browser.

   - bpo-45606(135): Fixed the bug in *note pathlib.Path.glob(): 538. –
     previously a dangling symlink would not be found by this method
     when the pattern is an exact match, but would be found when the
     pattern contains a wildcard or the recursive wildcard (‘**’).  With
     this change, a dangling symlink will be found in both cases.

   - bpo-23041(136): Add *note QUOTE_STRINGS: 6ae. and *note
     QUOTE_NOTNULL: 6ad. to the suite of *note csv: 2d. module quoting
     styles.

   - bpo-24964(137): Added *note
     http.client.HTTPConnection.get_proxy_response_headers(): 1a5b. that
     provides access to the HTTP headers on a proxy server response to
     the ‘CONNECT’ request.

   - bpo-17258(138): *note multiprocessing: 98. now supports stronger
     HMAC algorithms for inter-process connection authentication rather
     than only HMAC-MD5.

   - bpo-39744(139): Make *note
     asyncio.subprocess.Process.communicate(): 1a87. close the
     subprocess’s stdin even when called with ‘input=None’.

   - bpo-22708(140): http.client CONNECT method tunnel improvements: Use
     HTTP 1.1 protocol; send a matching Host: header with CONNECT, if
     one is not provided; convert IDN domain names to Punycode.  Patch
     by Michael Handler.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31821

   (2) https://github.com/python/cpython/issues/104600

   (3) https://peps.python.org/pep-0695/

   (4) https://github.com/python/cpython/issues/104340

   (5) https://github.com/python/cpython/issues/104555

   (6) https://github.com/python/cpython/issues/104372

   (7) https://github.com/python/cpython/issues/104484

   (8) https://github.com/python/cpython/issues/75367

   (9) https://github.com/python/cpython/issues/104536

   (10) https://github.com/python/cpython/issues/103857

   (11) https://github.com/python/cpython/issues/101520

   (12) https://github.com/python/cpython/issues/104392

   (13) https://github.com/python/cpython/issues/102613

   (14) https://github.com/python/cpython/issues/103000

   (15) https://github.com/python/cpython/issues/104301

   (16) https://github.com/python/cpython/issues/104139

   (17) 
https://support.apple.com/en-gb/guide/deployment/depce7cefc4d/web

   (18) https://github.com/python/cpython/issues/104307

   (19) https://github.com/python/cpython/issues/104310

   (20) https://github.com/python/cpython/issues/87695

   (21) https://github.com/python/cpython/issues/104265

   (22) https://bugs.python.org/issue?@action=redirect&bpo=14935

   (23) https://github.com/python/cpython/issues/102613

   (24) https://github.com/python/cpython/issues/65772

   (25) https://github.com/python/cpython/issues/90208

   (26) https://github.com/python/cpython/issues/104144

   (27) https://github.com/python/cpython/issues/104144

   (28) https://github.com/python/cpython/issues/104114

   (29) https://github.com/python/cpython/issues/104104

   (30) https://github.com/python/cpython/issues/104102

   (31) https://github.com/python/cpython/issues/103822

   (32) https://github.com/python/cpython/issues/103629

   (33) https://peps.python.org/pep-0692/

   (34) https://github.com/python/cpython/issues/103963

   (35) https://github.com/python/cpython/issues/104035

   (36) https://github.com/python/cpython/issues/103987

   (37) https://github.com/python/cpython/issues/103977

   (38) https://github.com/python/cpython/issues/88773

   (39) https://github.com/python/cpython/issues/103935

   (40) https://github.com/python/cpython/issues/68968

   (41) https://github.com/python/cpython/issues/100370

   (42) https://github.com/python/cpython/issues/102628

   (43) https://github.com/python/cpython/issues/103636

   (44) https://github.com/python/cpython/issues/103583

   (45) https://github.com/python/cpython/issues/103848

   (46) https://github.com/python/cpython/issues/103872

   (47) https://github.com/python/cpython/issues/99944

   (48) https://github.com/python/cpython/issues/74940

   (49) https://github.com/python/cpython/issues/103861

   (50) https://github.com/python/cpython/issues/103857

   (51) https://github.com/python/cpython/issues/103839

   (52) https://github.com/python/cpython/issues/103791

   (53) https://github.com/python/cpython/issues/90750

   (54) https://github.com/python/cpython/issues/103685

   (55) https://github.com/python/cpython/issues/81403

   (56) https://github.com/python/cpython/issues/103699

   (57) https://github.com/python/cpython/issues/103693

   (58) https://github.com/python/cpython/issues/92248

   (59) https://github.com/python/cpython/issues/89415

   (60) https://github.com/python/cpython/issues/103673

   (61) https://github.com/python/cpython/issues/103636

   (62) https://github.com/python/cpython/issues/84976

   (63) https://github.com/python/cpython/issues/103596

   (64) https://github.com/python/cpython/issues/103584

   (65) https://github.com/python/cpython/issues/103578

   (66) https://github.com/python/cpython/issues/103556

   (67) https://github.com/python/cpython/issues/103559

   (68) https://github.com/python/cpython/issues/103548

   (69) https://github.com/python/cpython/issues/103538

   (70) https://github.com/python/cpython/issues/103533

   (71) https://github.com/python/cpython/issues/103525

   (72) https://github.com/python/cpython/issues/103489

   (73) https://github.com/python/cpython/issues/103365

   (74) https://github.com/python/cpython/issues/103472

   (75) https://github.com/python/cpython/issues/103462

   (76) https://github.com/python/cpython/issues/103449

   (77) https://github.com/python/cpython/issues/103092

   (78) https://peps.python.org/pep-0687/

   (79) https://github.com/python/cpython/issues/103357

   (80) https://github.com/python/cpython/issues/103092

   (81) https://peps.python.org/pep-0687/

   (82) https://github.com/python/cpython/issues/74690

   (83) https://github.com/python/cpython/issues/74690

   (84) https://github.com/python/cpython/issues/103256

   (85) https://github.com/python/cpython/issues/102778

   (86) https://github.com/python/cpython/issues/103285

   (87) https://github.com/python/cpython/issues/103225

   (88) https://github.com/python/cpython/issues/103092

   (89) https://peps.python.org/pep-0687/

   (90) https://github.com/python/cpython/issues/103092

   (91) https://peps.python.org/pep-0687/

   (92) https://github.com/python/cpython/issues/93910

   (93) https://github.com/python/cpython/issues/102978

   (94) https://github.com/python/cpython/issues/103092

   (95) https://peps.python.org/pep-0687/

   (96) https://github.com/python/cpython/issues/100479

   (97) https://github.com/python/cpython/issues/103220

   (98) https://github.com/python/cpython/issues/103204

   (99) https://github.com/python/cpython/issues/75586

   (100) https://github.com/python/cpython/issues/103193

   (101) https://github.com/python/cpython/issues/103176

   (102) https://github.com/python/cpython/issues/103143

   (103) https://github.com/python/cpython/issues/103015

   (104) https://github.com/python/cpython/issues/103000

   (105) https://github.com/python/cpython/issues/102953

   (106) https://github.com/python/cpython/issues/97696

   (107) https://github.com/python/cpython/issues/81079

   (108) https://github.com/python/cpython/issues/101819

   (109) https://peps.python.org/pep-0687/

   (110) https://github.com/python/cpython/issues/91896

   (111) https://github.com/python/cpython/issues/101362

   (112) https://github.com/python/cpython/issues/102114

   (113) https://github.com/python/cpython/issues/62432

   (114) https://github.com/python/cpython/issues/78079

   (115) https://github.com/python/cpython/issues/85984

   (116) https://github.com/python/cpython/issues/101688

   (117) https://github.com/python/cpython/issues/101640

   (118) https://github.com/python/cpython/issues/83861

   (119) https://github.com/python/cpython/issues/89550

   (120) https://github.com/python/cpython/issues/95299

   (121) https://github.com/python/cpython/issues/99353

   (122) https://github.com/python/cpython/issues/98040

   (123) https://github.com/python/cpython/issues/97850

   (124) https://github.com/python/cpython/issues/94473

   (125) https://github.com/python/cpython/issues/98040

   (126) https://github.com/python/cpython/issues/96522

   (127) https://github.com/python/cpython/issues/96534

   (128) https://github.com/python/cpython/issues/87474

   (129) https://github.com/python/cpython/issues/94906

   (130) https://github.com/python/cpython/issues/51574

   (131) https://github.com/python/cpython/issues/94518

   (132) https://github.com/python/cpython/issues/92184

   (133) https://bugs.python.org/issue?@action=redirect&bpo=46797

   (134) https://bugs.python.org/issue?@action=redirect&bpo=44844

   (135) https://bugs.python.org/issue?@action=redirect&bpo=45606

   (136) https://bugs.python.org/issue?@action=redirect&bpo=23041

   (137) https://bugs.python.org/issue?@action=redirect&bpo=24964

   (138) https://bugs.python.org/issue?@action=redirect&bpo=17258

   (139) https://bugs.python.org/issue?@action=redirect&bpo=39744

   (140) https://bugs.python.org/issue?@action=redirect&bpo=22708


File: python.info,  Node: Documentation<20>,  Next: Tests<20>,  Prev: Library<66>,  Up: Python 3 12 0 beta 1

1.24.26.7 Documentation
.......................

   - gh-67056(1): Document that the effect of registering or
     unregistering an *note atexit: d. cleanup function from within a
     registered cleanup function is undefined.

   - gh-103629(2): Mention the new way of typing ‘**kwargs’ with
     ‘Unpack’ and ‘TypedDict’ introduced in PEP 692(3).

   - gh-48241(4): Clarifying documentation about the url parameter to
     urllib.request.urlopen and urllib.request.Request needing to be
     encoded properly.

   - gh-86094(5): Add support for Unicode Path Extra Field in ZipFile.
     Patch by Yeojin Kim and Andrea Giudiceandrea

   - gh-99202(6): Fix extension type from documentation for compiling in
     C++20 mode

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/67056

   (2) https://github.com/python/cpython/issues/103629

   (3) https://peps.python.org/pep-0692/

   (4) https://github.com/python/cpython/issues/48241

   (5) https://github.com/python/cpython/issues/86094

   (6) https://github.com/python/cpython/issues/99202


File: python.info,  Node: Tests<20>,  Next: Build<23>,  Prev: Documentation<20>,  Up: Python 3 12 0 beta 1

1.24.26.8 Tests
...............

   - gh-104494(1): Update ‘test_pack_configure_in’ and
     ‘test_place_configure_in’ for changes to error message formatting
     in Tk 8.7.

   - gh-104461(2): Run test_configure_screen on X11 only, since the
     ‘DISPLAY’ environment variable and ‘-screen’ option for toplevels
     are not useful on Tk for Win32 or Aqua.

   - gh-86275(3): Added property-based tests to the *note zoneinfo: 13a.
     tests, along with stubs for the ‘hypothesis’ interface.  (Patch by
     Paul Ganssle)

   - gh-103329(4): Regression tests for the behaviour of
     ‘unittest.mock.PropertyMock’ were added.

   - gh-102795(5): fix use of poll in test_epoll’s test_control_and_wait

   - gh-75729(6): Fix the *note os.spawn*: 31b. tests failing on Windows
     when the working directory or interpreter path contains spaces.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104494

   (2) https://github.com/python/cpython/issues/104461

   (3) https://github.com/python/cpython/issues/86275

   (4) https://github.com/python/cpython/issues/103329

   (5) https://github.com/python/cpython/issues/102795

   (6) https://github.com/python/cpython/issues/75729


File: python.info,  Node: Build<23>,  Next: Windows<21>,  Prev: Tests<20>,  Up: Python 3 12 0 beta 1

1.24.26.9 Build
...............

   - gh-101282(1): BOLT optimization is now applied to the libpython
     shared library if building a shared library.  BOLT instrumentation
     and application settings can now be influenced via the
     ‘BOLT_INSTRUMENT_FLAGS’ and ‘BOLT_APPLY_FLAGS’ configure variables.

   - gh-99017(2): ‘PYTHON_FOR_REGEN’ now require Python 3.10 or newer.

   - gh-104490(3): Define ‘.PHONY’ / virtual make targets consistently
     and properly.

   - gh-104106(4): Add gcc fallback of mkfifoat/mknodat for macOS. Patch
     by Donghee Na.

   - gh-103532(5): The ‘TKINTER_PROTECT_LOADTK’ macro is no longer
     defined or used in the ‘_tkinter’ module.  It was previously only
     defined when building against Tk 8.4.13 and older, but Tk older
     than 8.5.12 has been unsupported since gh-91152(6).

   - gh-99069(7): Extended workaround defining ‘static_assert’ when
     missing from the libc headers to all clang and gcc builds.  In
     particular, this fixes building on macOS <= 10.10.

   - gh-100220(8): Changed the default value of the ‘SHELL’ Makefile
     variable from ‘/bin/sh’ to ‘/bin/sh -e’ to ensure that complex
     recipes correctly fail after an error.  Previously, ‘make install’
     could fail to install some files and yet return a successful
     result.

   - gh-90656(9): Add platform triplets for 64-bit LoongArch:

        * loongarch64-linux-gnusf

        * loongarch64-linux-gnuf32

        * loongarch64-linux-gnu

     Patch by Zhang Na.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101282

   (2) https://github.com/python/cpython/issues/99017

   (3) https://github.com/python/cpython/issues/104490

   (4) https://github.com/python/cpython/issues/104106

   (5) https://github.com/python/cpython/issues/103532

   (6) https://github.com/python/cpython/issues/91152

   (7) https://github.com/python/cpython/issues/99069

   (8) https://github.com/python/cpython/issues/100220

   (9) https://github.com/python/cpython/issues/90656


File: python.info,  Node: Windows<21>,  Next: macOS<14>,  Prev: Build<23>,  Up: Python 3 12 0 beta 1

1.24.26.10 Windows
..................

   - gh-104623(1): Update Windows installer to use SQLite 3.42.0.

   - gh-82814(2): Fix a potential ‘[Errno 13] Permission denied’ when
     using *note shutil.copystat(): 1336. within Windows Subsystem for
     Linux (WSL) on a mounted filesystem by adding ‘errno.EACCES’ to the
     list of ignored errors within the internal implementation.

   - gh-103088(3): Fix virtual environment ‘activate’ script having
     incorrect line endings for Cygwin.

   - gh-103088(4): Fixes venvs not working in bash on Windows across
     different disks

   - gh-102997(5): Update Windows installer to use SQLite 3.41.2.

   - gh-88013(6): Fixed a bug where *note TypeError: 198. was raised
     when calling ‘ntpath.realpath()’ with a bytes parameter in some
     cases.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104623

   (2) https://github.com/python/cpython/issues/82814

   (3) https://github.com/python/cpython/issues/103088

   (4) https://github.com/python/cpython/issues/103088

   (5) https://github.com/python/cpython/issues/102997

   (6) https://github.com/python/cpython/issues/88013


File: python.info,  Node: macOS<14>,  Next: IDLE<14>,  Prev: Windows<21>,  Up: Python 3 12 0 beta 1

1.24.26.11 macOS
................

   - gh-99834(1): Update macOS installer to Tcl/Tk 8.6.13.

   - gh-104623(2): Update macOS installer to SQLite 3.42.0.

   - gh-103545(3): Add ‘os.PRIO_DARWIN_THREAD’,
     ‘os.PRIO_DARWIN_PROCESS’, ‘os.PRIO_DARWIN_BG’ and
     ‘os.PRIO_DARWIN_NONUI’.  These can be used with ‘os.setpriority’ to
     run the process at a lower priority and make use of the efficiency
     cores on Apple Silicon systems.

   - gh-104180(4): Support reading SOCKS proxy configuration from macOS
     System Configuration.  Patch by Sam Schott.

   - gh-60436(5): update curses textbox to additionally handle backspace
     using the ‘curses.ascii.DEL’ key press.

   - gh-102997(6): Update macOS installer to SQLite 3.41.2.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99834

   (2) https://github.com/python/cpython/issues/104623

   (3) https://github.com/python/cpython/issues/103545

   (4) https://github.com/python/cpython/issues/104180

   (5) https://github.com/python/cpython/issues/60436

   (6) https://github.com/python/cpython/issues/102997


File: python.info,  Node: IDLE<14>,  Next: Tools/Demos<20>,  Prev: macOS<14>,  Up: Python 3 12 0 beta 1

1.24.26.12 IDLE
...............

   - gh-104499(1): Fix completions for Tk Aqua 8.7 (currently blank).

   - gh-104496(2): About prints both tcl and tk versions if different
     (expected someday).

   - gh-88496(3): Fix IDLE test hang on macOS.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104499

   (2) https://github.com/python/cpython/issues/104496

   (3) https://github.com/python/cpython/issues/88496


File: python.info,  Node: Tools/Demos<20>,  Next: C API<23>,  Prev: IDLE<14>,  Up: Python 3 12 0 beta 1

1.24.26.13 Tools/Demos
......................

   - gh-104389(1): Argument Clinic C converters now accept the ‘unused’
     keyword, for wrapping a parameter with *note Py_UNUSED: 1a72.
     Patch by Erlend E. Aasland.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/104389


File: python.info,  Node: C API<23>,  Prev: Tools/Demos<20>,  Up: Python 3 12 0 beta 1

1.24.26.14 C API
................

   - gh-101291(1): Added unstable C API for extracting the value of
     «compact» integers: *note PyUnstable_Long_IsCompact(): 7a7. and
     *note PyUnstable_Long_CompactValue(): 7a8.

   - gh-104109(2): We’ve added ‘Py_NewInterpreterFromConfig()’ and
     ‘PyInterpreterConfig’ to the public C-API (but not the stable ABI;
     not yet at least).  The new function may be used to create a new
     interpreter with various features configured.  The function was
     added to support PEP 684 (per-interpreter GIL).

   - gh-103968(3): *note PyType_FromSpec(): 79e. and its variants now
     allow creating classes whose metaclass overrides *note tp_new: 7a0.
     The ‘tp_new’ is ignored.  This behavior is deprecated and will be
     disallowed in 3.14+.  The new *note PyType_FromMetaclass(): 773.
     already disallows it.

   - gh-103743(4): Add *note PyUnstable_Object_GC_NewWithExtraData():
     1a90. function that can be used to allocate additional memory after
     an object for data not managed by Python.

   - gh-103295(5): Introduced *note PyUnstable_WritePerfMapEntry():
     1a91, *note PyUnstable_PerfMapState_Init(): 1a92. and *note
     PyUnstable_PerfMapState_Fini(): 1a93.  These allow extension
     modules (JIT compilers in particular) to write to perf-map files in
     a thread safe manner.  The *note Python support for the Linux perf
     profiler: 1a94. also uses these APIs to write entries in the
     perf-map file.

   - gh-103509(6): Added C API for extending types whose instance memory
     layout is opaque: *note PyType_Spec.basicsize: 76b. can now be zero
     or negative, *note PyObject_GetTypeData(): 76c. can be used to get
     subclass-specific data, and *note Py_TPFLAGS_ITEMS_AT_END: 76e. can
     be used to safely extend variable-size objects.  See PEP 697(7) for
     details.

   - gh-103091(8): Add a new C-API function to eagerly assign a version
     tag to a PyTypeObject: ‘PyUnstable_Type_AssignVersionTag()’.

   - gh-101408(9): *note PyObject_GC_Resize: 1a95. should calculate
     preheader size if needed.  Patch by Donghee Na.

   - gh-98836(10): Add support of more formatting options (left
     aligning, octals, uppercase hexadecimals, ‘intmax_t’, ‘ptrdiff_t’,
     ‘wchar_t’ C strings, variable width and precision) in *note
     PyUnicode_FromFormat(): 62b. and *note PyUnicode_FromFormatV():
     795.

   - gh-96803(11): Add unstable C-API functions to get the code object,
     lasti and line number from the internal ‘_PyInterpreterFrame’ in
     the limited API. The functions are:

        * ‘PyCodeObject * PyUnstable_InterpreterFrame_GetCode(struct
          _PyInterpreterFrame *frame)’

        * ‘int PyUnstable_InterpreterFrame_GetLasti(struct
          _PyInterpreterFrame *frame)’

        * ‘int PyUnstable_InterpreterFrame_GetLine(struct
          _PyInterpreterFrame *frame)’

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101291

   (2) https://github.com/python/cpython/issues/104109

   (3) https://github.com/python/cpython/issues/103968

   (4) https://github.com/python/cpython/issues/103743

   (5) https://github.com/python/cpython/issues/103295

   (6) https://github.com/python/cpython/issues/103509

   (7) https://peps.python.org/pep-0697/

   (8) https://github.com/python/cpython/issues/103091

   (9) https://github.com/python/cpython/issues/101408

   (10) https://github.com/python/cpython/issues/98836

   (11) https://github.com/python/cpython/issues/96803


File: python.info,  Node: Python 3 12 0 alpha 7,  Next: Python 3 12 0 alpha 6,  Prev: Python 3 12 0 beta 1,  Up: Changelog

1.24.27 Python 3.12.0 alpha 7
-----------------------------

'Release date: 2023-04-04'

* Menu:

* Core and Builtins: Core and Builtins<61>.
* Library: Library<67>.
* Core and Builtins: Core and Builtins<62>.
* Build: Build<24>.
* Core and Builtins: Core and Builtins<63>.
* Library: Library<68>.
* Documentation: Documentation<21>.
* Tests: Tests<21>.
* Build: Build<25>.
* Windows: Windows<22>.
* Tools/Demos: Tools/Demos<21>.
* C API: C API<24>.


File: python.info,  Node: Core and Builtins<61>,  Next: Library<67>,  Up: Python 3 12 0 alpha 7

1.24.27.1 Core and Builtins
...........................

   - gh-102192(1): Deprecated ‘_PyErr_ChainExceptions’ in favour of
     ‘_PyErr_ChainExceptions1’.

   - gh-89987(2): Reduce the number of inline *note CACHE: 909. entries
     for ‘BINARY_SUBSCR’.

   - gh-102859(3): Removed ‘JUMP_IF_FALSE_OR_POP’ and
     ‘JUMP_IF_TRUE_OR_POP’ instructions.

   - gh-101975(4): Fixed ‘stacktop’ value on tracing entries to avoid
     corruption on garbage collection.

   - gh-102778(5): Add *note sys.last_exc: 6e6. and deprecate *note
     sys.last_type: 6e7, *note sys.last_value: 6e8. and *note
     sys.last_traceback: 6e9, which hold the same information in its
     legacy form.

   - gh-100982(6): Replace all occurrences of ‘COMPARE_AND_BRANCH’ with
     *note COMPARE_OP: b63.

   - gh-102701(7): Fix overflow when creating very large dict.

   - gh-102755(8): Add *note PyErr_DisplayException(): 435. which takes
     just an exception instance, to replace the legacy ‘PyErr_Display()’
     which takes the ‘(typ, exc, tb)’ triplet.

   - gh-102594(9): Add note to exception raised in ‘PyErr_SetObject’
     when normalization fails.

   - gh-90997(10): Shrink the number of inline *note CACHE: 909. entries
     used by *note LOAD_GLOBAL: 1a42.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102192

   (2) https://github.com/python/cpython/issues/89987

   (3) https://github.com/python/cpython/issues/102859

   (4) https://github.com/python/cpython/issues/101975

   (5) https://github.com/python/cpython/issues/102778

   (6) https://github.com/python/cpython/issues/100982

   (7) https://github.com/python/cpython/issues/102701

   (8) https://github.com/python/cpython/issues/102755

   (9) https://github.com/python/cpython/issues/102594

   (10) https://github.com/python/cpython/issues/90997


File: python.info,  Node: Library<67>,  Next: Core and Builtins<62>,  Prev: Core and Builtins<61>,  Up: Python 3 12 0 alpha 7

1.24.27.2 Library
.................

   - gh-102491(1): Improve import time of ‘platform’ by removing
     IronPython version parsing.  The IronPython version parsing was not
     functional (see
     ‘https://github.com/IronLanguages/ironpython3/issues/1667’).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102491


File: python.info,  Node: Core and Builtins<62>,  Next: Build<24>,  Prev: Library<67>,  Up: Python 3 12 0 alpha 7

1.24.27.3 Core and Builtins
...........................

   - gh-101291(1): Rearrage bits in first field (after header) of
     PyLongObject.  * Bits 0 and 1: 1 - sign.  I.e.  0 for positive
     numbers, 1 for zero and 2 for negative numbers.  * Bit 2 reserved
     (probably for the immortal bit) * Bits 3+ the unsigned size.

     This makes a few operations slightly more efficient, and will
     enable a more compact and faster 2s-complement representation of
     most ints in future.

   - gh-102397(2): Fix segfault from race condition in signal handling
     during garbage collection.  Patch by Kumar Aditya.

   - gh-102406(3): *note codecs: 1c. encoding/decoding errors now get
     the context information (which operation and which codecs) attached
     as PEP 678(4) notes instead of through chaining a new instance of
     the exception.

   - gh-102281(5): Fix potential nullptr dereference and use of
     uninitialized memory in fileutils.  Patch by Max Bachmann.

   - gh-102300(6): Reuse operands with refcount of 1 in float
     specializations of BINARY_OP.

   - gh-102213(7): Fix performance loss when accessing an object’s
     attributes with ‘__getattr__’ defined.

   - gh-102255(8): Improve build support for the Xbox.  Patch by Max
     Bachmann.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101291

   (2) https://github.com/python/cpython/issues/102397

   (3) https://github.com/python/cpython/issues/102406

   (4) https://peps.python.org/pep-0678/

   (5) https://github.com/python/cpython/issues/102281

   (6) https://github.com/python/cpython/issues/102300

   (7) https://github.com/python/cpython/issues/102213

   (8) https://github.com/python/cpython/issues/102255


File: python.info,  Node: Build<24>,  Next: Core and Builtins<63>,  Prev: Core and Builtins<62>,  Up: Python 3 12 0 alpha 7

1.24.27.4 Build
...............

   - gh-102027(1): Fix SSE2 and SSE3 detection in ‘_blake2’ internal
     module.  Patch by Max Bachmann.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102027


File: python.info,  Node: Core and Builtins<63>,  Next: Library<68>,  Prev: Build<24>,  Up: Python 3 12 0 alpha 7

1.24.27.5 Core and Builtins
...........................

   - gh-101865(1): Deprecate ‘co_lnotab’ in code objects, schedule it
     for removal in Python 3.14

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101865


File: python.info,  Node: Library<68>,  Next: Documentation<21>,  Prev: Core and Builtins<63>,  Up: Python 3 12 0 alpha 7

1.24.27.6 Library
.................

   - bpo-1635741(1): Adapt ‘_pickle’ to PEP 687(2).  Patch by Mohamed
     Koubaa and Erlend Aasland.

   - gh-103085(3): Pure python *note locale.getencoding(): 329. will not
     warn deprecation.

   - gh-103068(4): It’s no longer possible to register conditional
     breakpoints in *note Pdb: 273. that raise *note SyntaxError: 18e.
     Patch by Tian Gao.

   - gh-102549(5): Don’t ignore exceptions in member type creation.

   - gh-103056(6): Ensure final ‘_generate_next_value_’ is a
     ‘staticmethod’.

   - gh-103046(7): Display current line label correctly in *note dis:
     3c. when ‘show_caches’ is False and ‘lasti’ points to a CACHE
     entry.

   - gh-102433(8): *note isinstance(): 2ad. checks against *note
     runtime-checkable protocols: 675. now use *note
     inspect.getattr_static(): 6bd. rather than *note hasattr(): 6fa. to
     lookup whether attributes exist.  This means that descriptors and
     *note __getattr__(): 6fb. methods are no longer unexpectedly
     evaluated during ‘isinstance()’ checks against runtime-checkable
     protocols.  However, it may also mean that some objects which used
     to be considered instances of a runtime-checkable protocol may no
     longer be considered instances of that protocol on Python 3.12+,
     and vice versa.  Most users are unlikely to be affected by this
     change.  Patch by Alex Waygood.

   - gh-103023(9): It’s no longer possible to register expressions to
     display in *note Pdb: 273. that raise *note SyntaxError: 18e.
     Patch by Tian Gao.

   - gh-102947(10): Improve traceback when *note dataclasses.fields():
     191d. is called on a non-dataclass.  Patch by Alex Waygood

   - gh-102780(11): The *note asyncio.Timeout: 1a28. context manager now
     works reliably even when performing cleanup due to task
     cancellation.  Previously it could raise a *note CancelledError:
     4d5. instead of an *note TimeoutError: 1a9d. in such cases.

   - gh-102871(12): Remove support for obsolete browsers from *note
     webbrowser: 11b.  Removed browsers include Grail, Mosaic, Netscape,
     Galeon, Skipstone, Iceape, Firebird, and Firefox versions 35 and
     below.

   - gh-102839(13): Improve performance of *note math.log(): 16c7.
     arguments handling by removing the argument clinic.

   - gh-102828(14): Add the ‘onexc’ arg to *note shutil.rmtree(): 356,
     which is like ‘onerror’ but expects an exception instance rather
     than an exc_info tuple.  Deprecate ‘onerror’.

   - gh-88965(15): typing: Fix a bug relating to substitution in custom
     classes generic over a *note ParamSpec: 488.  Previously, if the
     ‘ParamSpec’ was substituted with a parameters list that itself
     contained a *note TypeVar: 487, the ‘TypeVar’ in the parameters
     list could not be subsequently substituted.  This is now fixed.

     Patch by Nikita Sobolev.

   - gh-76846(16): Fix issue where ‘__new__()’ and ‘__init__()’ methods
     of *note pathlib.PurePath: 6ce. and *note Path: 266. subclasses
     were not called in some circumstances.

   - gh-78530(17): *note asyncio.wait(): 6a8. now accepts generators
     yielding tasks.  Patch by Kumar Aditya.

   - gh-102748(18): *note asyncio.iscoroutine(): 6a7. now returns
     ‘False’ for generators as *note asyncio: b. does not support legacy
     generator-based coroutines.  Patch by Kumar Aditya.

   - gh-102670(19): Optimized fmean(), correlation(), covariance(), and
     linear_regression() using the new math.sumprod() function.

   - gh-102615(20): Typing: Improve the ‘repr’ of generic aliases for
     classes generic over a *note ParamSpec: 488.  (Use square brackets
     to represent a parameter list.)

   - gh-100112(21): *note asyncio.Task.get_coro(): bd1. now always
     returns a coroutine when wrapping an awaitable object.  Patch by
     Kumar Aditya.

   - gh-102578(22): Speed up setting or deleting mutable attributes on
     non-dataclass subclasses of frozen dataclasses.  Due to the
     implementation of ‘__setattr__’ and ‘__delattr__’ for frozen
     dataclasses, this previously had a time complexity of 'O'('n').  It
     now has a time complexity of 'O'(1).

   - gh-102519(23): Add *note os.listdrives(): 6c6, *note
     os.listvolumes(): 6c7. and *note os.listmounts(): 6c8. functions on
     Windows for enumerating drives, volumes and mount points

   - gh-74468(24): Attribute name of the extracted *note tarfile: e4.
     file object now holds filename of itself rather than of the archive
     it is contained in.  Patch by Oleg Iarygin.

   - gh-102378(25): Private helper method
     ‘inspect._signature_strip_non_python_syntax’ will no longer strip
     ‘/’ from the input string.

   - gh-79940(26): Add *note inspect.getasyncgenstate(): 6bb. and *note
     inspect.getasyncgenlocals(): 6bc.  Patch by Thomas Krennwallner.

   - gh-102103(27): Add ‘module’ argument to *note
     dataclasses.make_dataclass(): 1844. and make classes produced by it
     pickleable.

   - gh-102069(28): Fix ‘__weakref__’ descriptor generation for custom
     dataclasses.

   - gh-102038(29): Skip a ‘stat’ in *note site: cc. if we have already
     found a ‘pyvenv.cfg’

   - gh-98886(30): Fix issues when defining dataclasses that have fields
     with specific underscore names that aren’t clearly reserved by
     *note dataclasses: 33.

   - gh-101673(31): Fix a *note pdb: aa. bug where ‘ll’ clears the
     changes to local variables.

   - gh-101313(32): Added -h and –help arguments to the webbrowser CLI

   - gh-100372(33): *note ssl.SSLContext.load_verify_locations(): 10f0.
     no longer incorrectly accepts some cases of trailing data when
     parsing DER.

   - gh-89727(34): Fix pathlib.Path.walk RecursionError on deep
     directory trees by rewriting it using iteration instead of
     recursion.

   - gh-100131(35): Added an optional ‘delete’ keyword argument to *note
     tempfile.TemporaryDirectory: 143c.

   - gh-48330(36): Added ‘--durations’ command line option, showing the
     N slowest test cases.  *note unittest.TextTestRunner: 1a9e. and
     *note unittest.TextTestResult: 755. constructors accept a new
     'durations' keyword argument.  Subclasses should take this into
     account or accept ‘**kwargs’.  Added *note
     unittest.TestResult.addDuration(): 1a9f. method and *note
     unittest.TestResult.collectedDurations: 1a64. attribute.

     (Contributed by Giampaolo Rodola)

   - gh-98169(37): Fix *note dataclasses.astuple(): 1a86. crash when
     *note collections.defaultdict: 13c4. is present in the attributes.

   - gh-96931(38): Fix incorrect results from *note
     ssl.SSLSocket.shared_ciphers(): 106e.

   - gh-95495(39): When built against OpenSSL 3.0, the *note ssl: d5.
     module had a bug where it reported unauthenticated EOFs (i.e.
     without close_notify) as a clean TLS-level EOF. It now raises *note
     SSLEOFError: 1aa0, matching the behavior in previous versions of
     OpenSSL. The *note options: a3b. attribute on *note SSLContext:
     357. also no longer includes *note OP_IGNORE_UNEXPECTED_EOF: a3a.
     by default.  This option may be set to specify the previous OpenSSL
     3.0 behavior.

   - gh-94684(40): Now *note uuid.uuid3(): 2e5. and *note uuid.uuid5():
     2e6. functions support *note bytes: 192. objects as their 'name'
     argument.

   - gh-94440(41): Fix a ‘concurrent.futures.process’ bug where
     ‘ProcessPoolExecutor’ shutdown could hang after a future has been
     quickly submitted and canceled.

   - gh-72346(42): Added deprecation warning to 'isdst' parameter of
     *note email.utils.localtime(): 2f7.

   - bpo-36305(43): Fix handling of Windows filenames that resemble
     drives, such as ‘./a:b’, in *note pathlib: a8.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (2) https://peps.python.org/pep-0687/

   (3) https://github.com/python/cpython/issues/103085

   (4) https://github.com/python/cpython/issues/103068

   (5) https://github.com/python/cpython/issues/102549

   (6) https://github.com/python/cpython/issues/103056

   (7) https://github.com/python/cpython/issues/103046

   (8) https://github.com/python/cpython/issues/102433

   (9) https://github.com/python/cpython/issues/103023

   (10) https://github.com/python/cpython/issues/102947

   (11) https://github.com/python/cpython/issues/102780

   (12) https://github.com/python/cpython/issues/102871

   (13) https://github.com/python/cpython/issues/102839

   (14) https://github.com/python/cpython/issues/102828

   (15) https://github.com/python/cpython/issues/88965

   (16) https://github.com/python/cpython/issues/76846

   (17) https://github.com/python/cpython/issues/78530

   (18) https://github.com/python/cpython/issues/102748

   (19) https://github.com/python/cpython/issues/102670

   (20) https://github.com/python/cpython/issues/102615

   (21) https://github.com/python/cpython/issues/100112

   (22) https://github.com/python/cpython/issues/102578

   (23) https://github.com/python/cpython/issues/102519

   (24) https://github.com/python/cpython/issues/74468

   (25) https://github.com/python/cpython/issues/102378

   (26) https://github.com/python/cpython/issues/79940

   (27) https://github.com/python/cpython/issues/102103

   (28) https://github.com/python/cpython/issues/102069

   (29) https://github.com/python/cpython/issues/102038

   (30) https://github.com/python/cpython/issues/98886

   (31) https://github.com/python/cpython/issues/101673

   (32) https://github.com/python/cpython/issues/101313

   (33) https://github.com/python/cpython/issues/100372

   (34) https://github.com/python/cpython/issues/89727

   (35) https://github.com/python/cpython/issues/100131

   (36) https://github.com/python/cpython/issues/48330

   (37) https://github.com/python/cpython/issues/98169

   (38) https://github.com/python/cpython/issues/96931

   (39) https://github.com/python/cpython/issues/95495

   (40) https://github.com/python/cpython/issues/94684

   (41) https://github.com/python/cpython/issues/94440

   (42) https://github.com/python/cpython/issues/72346

   (43) https://bugs.python.org/issue?@action=redirect&bpo=36305


File: python.info,  Node: Documentation<21>,  Next: Tests<21>,  Prev: Library<68>,  Up: Python 3 12 0 alpha 7

1.24.27.7 Documentation
.......................

   - gh-103112(1): Add docstring to *note
     http.client.HTTPResponse.read(): 1897. to fix ‘pydoc’ output.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/103112


File: python.info,  Node: Tests<21>,  Next: Build<25>,  Prev: Documentation<21>,  Up: Python 3 12 0 alpha 7

1.24.27.8 Tests
...............

   - gh-102980(1): Improve test coverage on *note pdb: aa.

   - gh-102537(2): Adjust the error handling strategy in
     ‘test_zoneinfo.TzPathTest.python_tzpath_context’.  Patch by Paul
     Ganssle.

   - gh-101377(3): Improved test_locale_calendar_formatweekday of
     calendar.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102980

   (2) https://github.com/python/cpython/issues/102537

   (3) https://github.com/python/cpython/issues/101377


File: python.info,  Node: Build<25>,  Next: Windows<22>,  Prev: Tests<21>,  Up: Python 3 12 0 alpha 7

1.24.27.9 Build
...............

   - gh-102973(1): Add a dev container (along with accompanying
     Dockerfile) for development purposes.

   - gh-102711(2): Fix ‘-Wstrict-prototypes’ compiler warnings.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102973

   (2) https://github.com/python/cpython/issues/102711


File: python.info,  Node: Windows<22>,  Next: Tools/Demos<21>,  Prev: Build<25>,  Up: Python 3 12 0 alpha 7

1.24.27.10 Windows
..................

   - gh-102690(1): Update *note webbrowser: 11b. to fall back to
     Microsoft Edge instead of Internet Explorer.

   - gh-99726(2): Improves correctness of stat results for Windows, and
     uses faster API when available

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102690

   (2) https://github.com/python/cpython/issues/99726


File: python.info,  Node: Tools/Demos<21>,  Next: C API<24>,  Prev: Windows<22>,  Up: Python 3 12 0 alpha 7

1.24.27.11 Tools/Demos
......................

   - gh-102809(1): ‘Misc/gdbinit’ was removed.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102809


File: python.info,  Node: C API<24>,  Prev: Tools/Demos<21>,  Up: Python 3 12 0 alpha 7

1.24.27.12 C API
................

   - gh-102013(1): Add a new (unstable) C-API function for iterating
     over GC’able objects using a callback: ‘PyUnstable_VisitObjects’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102013


File: python.info,  Node: Python 3 12 0 alpha 6,  Next: Python 3 12 0 alpha 5,  Prev: Python 3 12 0 alpha 7,  Up: Changelog

1.24.28 Python 3.12.0 alpha 6
-----------------------------

'Release date: 2023-03-07'

* Menu:

* Security: Security<23>.
* Core and Builtins: Core and Builtins<64>.
* Library: Library<69>.
* Documentation: Documentation<22>.
* Tests: Tests<22>.
* Build: Build<26>.
* Windows: Windows<23>.
* macOS: macOS<15>.
* C API: C API<25>.


File: python.info,  Node: Security<23>,  Next: Core and Builtins<64>,  Up: Python 3 12 0 alpha 6

1.24.28.1 Security
..................

   - gh-99108(1): Replace builtin hashlib implementations of MD5 and
     SHA1 with verified ones from the HACL* project.

   - gh-101727(2): Updated the OpenSSL version used in Windows and macOS
     binary release builds to 1.1.1t to address CVE 2023-0286(3), CVE
     2022-4303(4), and CVE 2022-4303(5) per the OpenSSL 2023-02-07
     security advisory(6).

   - gh-99108(7): Replace the builtin *note hashlib: 6c. implementations
     of SHA2-384 and SHA2-512 originally from LibTomCrypt with formally
     verified, side-channel resistant code from the HACL*(8) project.
     The builtins remain a fallback only used when OpenSSL does not
     provide them.

   - gh-101283(9): *note subprocess.Popen: 4b8. now uses a safer
     approach to find ‘cmd.exe’ when launching with ‘shell=True’.  Patch
     by Eryk Sun, based on a patch by Oleg Iarygin.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99108

   (2) https://github.com/python/cpython/issues/101727

   (3) https://www.cve.org/CVERecord?id=CVE-2023-0286

   (4) https://www.cve.org/CVERecord?id=CVE-2022-4303

   (5) https://www.cve.org/CVERecord?id=CVE-2022-4303

   (6) https://openssl-library.org/news/secadv/20230207.txt

   (7) https://github.com/python/cpython/issues/99108

   (8) https://github.com/hacl-star/hacl-star/

   (9) https://github.com/python/cpython/issues/101283


File: python.info,  Node: Core and Builtins<64>,  Next: Library<69>,  Prev: Security<23>,  Up: Python 3 12 0 alpha 6

1.24.28.2 Core and Builtins
...........................

   - gh-102493(1): Fix regression in semantics of normalisation in
     ‘PyErr_SetObject’.

   - gh-102416(2): Do not memoize incorrectly automatically generated
     loop rules in the parser.  Patch by Pablo Galindo.

   - gh-102356(3): Fix a bug that caused a crash when deallocating
     deeply nested filter objects.  Patch by Marta Gómez Macías.

   - gh-102336(4): Cleanup Windows 7 specific special handling.  Patch
     by Max Bachmann.

   - gh-102250(5): Fixed a segfault occurring when the interpreter calls
     a ‘__bool__’ method that raises.

   - gh-102126(6): Fix deadlock at shutdown when clearing thread states
     if any finalizer tries to acquire the runtime head lock.  Patch by
     Kumar Aditya.

   - gh-102027(7): Use ‘GetCurrentProcessId’ on Windows when ‘getpid’ is
     unavailable.  Patch by Max Bachmann.

   - gh-102056(8): Fix error handling bugs in interpreter’s exception
     printing code, which could cause a crash on infinite recursion.

   - gh-100982(9): Restrict the scope of the ‘FOR_ITER_RANGE’
     instruction to the scope of the original *note FOR_ITER: 1aaa.
     instruction, to allow instrumentation.

   - gh-101967(10): Fix possible segfault in
     ‘positional_only_passed_as_keyword’ function, when new list
     created.

   - gh-101952(11): Fix possible segfault in ‘BUILD_SET’ opcode, when
     new set created.

   - gh-74895(12): *note socket.getaddrinfo: 1aab. no longer raises
     *note OverflowError: a83. for *note int: 19b. 'port' values outside
     of the C long range.  Out of range values are left up to the
     underlying string based C library API to report.  A *note
     socket.gaierror: 1aac. ‘SAI_SERVICE’ may occur instead, or no error
     at all as not all platform C libraries generate an error.

   - gh-101799(13): Add *note CALL_INTRINSIC_2: 709. and use it instead
     of ‘PREP_RERAISE_STAR’.

   - gh-101857(14): Fix xattr support detection on Linux systems by
     widening the check to linux, not just glibc.  This fixes support
     for musl.

   - gh-84783(15): Make the slice object hashable.  Patch by Will
     Bradshaw and Furkan Onder.

   - gh-87849(16): Change the ‘SEND’ instruction to leave the receiver
     on the stack.  This allows the specialized form of ‘SEND’ to skip
     the chain of C calls and jump directly to the ‘RESUME’ in the
     generator or coroutine.

   - gh-101765(17): Fix SystemError / segmentation fault in iter
     ‘__reduce__’ when internal access of ‘builtins.__dict__’ keys
     mutates the iter object.

   - gh-101430(18): Update *note tracemalloc: 105. to handle presize of
     object properly.  Patch by Donghee Na.

   - gh-101696(19): Invalidate type version tag in
     ‘_PyStaticType_Dealloc’ for static types, avoiding bug where a
     false cache hit could crash the interpreter.  Patch by Kumar
     Aditya.

   - gh-101632(20): Adds a new ‘RETURN_CONST’ instruction.

   - gh-100719(21): Remove gi_code field from generator (and coroutine
     and async generator) objects as it is redundant.  The frame already
     includes a reference to the code object.

   - gh-98627(22): When an interpreter is configured to check (and only
     then), importing an extension module will now fail when the
     extension does not support multiple interpreters (i.e.  doesn’t
     implement PEP 489 multi-phase init).  This does not apply to the
     main interpreter, nor to subinterpreters created with
     ‘Py_NewInterpreter()’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102493

   (2) https://github.com/python/cpython/issues/102416

   (3) https://github.com/python/cpython/issues/102356

   (4) https://github.com/python/cpython/issues/102336

   (5) https://github.com/python/cpython/issues/102250

   (6) https://github.com/python/cpython/issues/102126

   (7) https://github.com/python/cpython/issues/102027

   (8) https://github.com/python/cpython/issues/102056

   (9) https://github.com/python/cpython/issues/100982

   (10) https://github.com/python/cpython/issues/101967

   (11) https://github.com/python/cpython/issues/101952

   (12) https://github.com/python/cpython/issues/74895

   (13) https://github.com/python/cpython/issues/101799

   (14) https://github.com/python/cpython/issues/101857

   (15) https://github.com/python/cpython/issues/84783

   (16) https://github.com/python/cpython/issues/87849

   (17) https://github.com/python/cpython/issues/101765

   (18) https://github.com/python/cpython/issues/101430

   (19) https://github.com/python/cpython/issues/101696

   (20) https://github.com/python/cpython/issues/101632

   (21) https://github.com/python/cpython/issues/100719

   (22) https://github.com/python/cpython/issues/98627


File: python.info,  Node: Library<69>,  Next: Documentation<22>,  Prev: Core and Builtins<64>,  Up: Python 3 12 0 alpha 6

1.24.28.3 Library
.................

   - gh-102302(1): Micro-optimise hashing of *note inspect.Parameter:
     4e5, reducing the time it takes to hash an instance by around 40%.

   - gh-101979(2): Fix a bug where parentheses in the ‘metavar’ argument
     to *note argparse.ArgumentParser.add_argument(): 4bd. were dropped.
     Patch by Yeojin Kim.

   - gh-91038(3): *note platform.platform(): 1aae. now has boolean
     default arguments.

   - gh-81652(4): Add *note mmap.MAP_ALIGNED_SUPER: 1aaf. FreeBSD and
     *note mmap.MAP_CONCEAL: 1ab0. OpenBSD constants to *note mmap: 94.
     Patch by Yeojin Kim.

   - gh-102179(5): Fix *note os.dup2(): d5c. error message for negative
     fds.

   - gh-101961(6): For the binary mode, ‘fileinput.hookcompressed()’
     doesn’t set the ‘encoding’ value even if the value is ‘None’.
     Patch by Gihwan Kim.

   - gh-101936(7): The default value of ‘fp’ becomes *note io.BytesIO:
     10a6. if *note HTTPError: 11e0. is initialized without a designated
     ‘fp’ parameter.  Patch by Long Vo.

   - gh-101566(8): In zipfile, sync Path with zipp 3.14(9), including
     fix for extractall on the underlying zipfile after being wrapped in
     ‘Path’.

   - gh-97930(10): Apply changes from importlib_resources 5.12(11),
     including fix for ‘MultiplexedPath’ to support directories in
     multiple namespaces (python/importlib_resources#265).

   - gh-101997(12): Upgrade pip wheel bundled with ensurepip (pip
     23.0.1)

   - gh-99108(13): The built-in extension modules for *note hashlib: 6c.
     SHA2 algorithms, used when OpenSSL does not provide them, now live
     in a single internal ‘_sha2’ module instead of separate ‘_sha256’
     and ‘_sha512’ modules.

   - gh-101892(14): Callable iterators no longer raise *note
     SystemError: 796. when the callable object exhausts the iterator
     but forgets to either return a sentinel value or raise *note
     StopIteration: df7.

   - gh-87634(15): Remove locking behavior from *note
     functools.cached_property(): 764.

   - gh-97786(16): Fix potential undefined behaviour in corner cases of
     floating-point-to-time conversions.

   - gh-101517(17): Fixed bug where *note bdb: 10. looks up the source
     line with *note linecache: 89. with a ‘lineno=None’, which causes
     it to fail with an unhandled exception.

   - gh-101773(18): Optimize *note fractions.Fraction: 213. for small
     components.  The private argument ‘_normalize’ of the *note
     fractions.Fraction: 213. constructor has been removed.

   - gh-101693(19): In *note sqlite3.Cursor.execute(): 5b0, *note
     DeprecationWarning: 1a3. is now emitted when *note named
     placeholders: 5b2. are used together with parameters supplied as a
     *note sequence: 717. instead of as a *note dict: 183.  Starting
     from Python 3.14, using named placeholders with parameters supplied
     as a sequence will raise a *note ProgrammingError: 305.  Patch by
     Erlend E. Aasland.

   - gh-101446(20): Change repr of *note collections.OrderedDict: 7f4.
     to use regular dictionary formatting instead of pairs of keys and
     values.

   - gh-101362(21): Speed up *note pathlib.PurePath: 6ce. construction
     by handling arguments more uniformly.  When a *note pathlib.Path:
     266. argument is supplied, we use its string representation rather
     than joining its parts with *note os.path.join(): 1991.

   - gh-101362(22): Speed up *note pathlib.PurePath: 6ce. construction
     by calling *note os.path.join(): 1991. only when two or more
     arguments are given.

   - gh-101362(23): Speed up *note pathlib.Path: 266. construction by
     running the path flavour compatibility check only when pathlib is
     imported.

   - gh-85984(24): Refactored the implementation of *note pty.fork():
     1ab1. to use *note os.login_tty(): 1ab2.

     A *note DeprecationWarning: 1a3. is now raised by
     ‘pty.master_open()’ and ‘pty.slave_open()’.  They were undocumented
     and deprecated long long ago in the docstring in favor of *note
     pty.openpty(): 301.

   - gh-101561(25): Add a new decorator *note typing.override(): 67d.
     See PEP 698(26) for details.  Patch by Steven Troxler.

   - gh-63301(27): Set exit code when *note tabnanny: e3. CLI exits on
     error.

   - gh-101360(28): Fix anchor matching in
     ‘pathlib.PureWindowsPath.match()’.  Path and pattern anchors are
     now matched with *note fnmatch: 60, just like other path parts.
     This allows patterns such as ‘"*:/Users/*"’ to be matched.

   - gh-101277(29): Remove global state from *note itertools: 85. module
     ( PEP 687(30)).  Patches by Erlend E. Aasland.

   - gh-100809(31): Fix handling of drive-relative paths (like “C:” and
     “C:foo”) in *note pathlib.Path.absolute(): 1a0e.  This method now
     uses the OS API to retrieve the correct current working directory
     for the drive.

   - gh-99138(32): Apply PEP 687(33) to *note zoneinfo: 13a.  Patch by
     Erlend E. Aasland.

   - gh-96764(34): *note asyncio.wait_for(): 816. now uses *note
     asyncio.timeout(): 815. as its underlying implementation.  Patch by
     Kumar Aditya.

   - gh-88233(35): Correctly preserve «extra» fields in ‘zipfile’
     regardless of their ordering relative to a zip64 «extra.»

   - bpo-23224(36): Fix segfaults when creating *note
     lzma.LZMADecompressor: 1ab3. and *note bz2.BZ2Decompressor: 1ab4.
     objects without calling ‘__init__()’, and fix leakage of locks and
     internal buffers when calling the ‘__init__()’ methods of *note
     lzma.LZMADecompressor: 1ab3, *note lzma.LZMACompressor: 1ab5, *note
     bz2.BZ2Compressor: 1ab6, and *note bz2.BZ2Decompressor: 1ab4.
     objects multiple times.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102302

   (2) https://github.com/python/cpython/issues/101979

   (3) https://github.com/python/cpython/issues/91038

   (4) https://github.com/python/cpython/issues/81652

   (5) https://github.com/python/cpython/issues/102179

   (6) https://github.com/python/cpython/issues/101961

   (7) https://github.com/python/cpython/issues/101936

   (8) https://github.com/python/cpython/issues/101566

   (9) https://zipp.readthedocs.io/en/latest/history.html#v3-14-0

   (10) https://github.com/python/cpython/issues/97930

   (11) 
https://importlib-resources.readthedocs.io/en/latest/history.html#v5-12-0

   (12) https://github.com/python/cpython/issues/101997

   (13) https://github.com/python/cpython/issues/99108

   (14) https://github.com/python/cpython/issues/101892

   (15) https://github.com/python/cpython/issues/87634

   (16) https://github.com/python/cpython/issues/97786

   (17) https://github.com/python/cpython/issues/101517

   (18) https://github.com/python/cpython/issues/101773

   (19) https://github.com/python/cpython/issues/101693

   (20) https://github.com/python/cpython/issues/101446

   (21) https://github.com/python/cpython/issues/101362

   (22) https://github.com/python/cpython/issues/101362

   (23) https://github.com/python/cpython/issues/101362

   (24) https://github.com/python/cpython/issues/85984

   (25) https://github.com/python/cpython/issues/101561

   (26) https://peps.python.org/pep-0698/

   (27) https://github.com/python/cpython/issues/63301

   (28) https://github.com/python/cpython/issues/101360

   (29) https://github.com/python/cpython/issues/101277

   (30) https://peps.python.org/pep-0687/

   (31) https://github.com/python/cpython/issues/100809

   (32) https://github.com/python/cpython/issues/99138

   (33) https://peps.python.org/pep-0687/

   (34) https://github.com/python/cpython/issues/96764

   (35) https://github.com/python/cpython/issues/88233

   (36) https://bugs.python.org/issue?@action=redirect&bpo=23224


File: python.info,  Node: Documentation<22>,  Next: Tests<22>,  Prev: Library<69>,  Up: Python 3 12 0 alpha 6

1.24.28.4 Documentation
.......................

   - gh-85417(1): Update *note cmath: 19. documentation to clarify
     behaviour on branch cuts.

   - gh-97725(2): Fix *note asyncio.Task.print_stack(): 1ab8.
     description for ‘file=None’.  Patch by Oleg Iarygin.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/85417

   (2) https://github.com/python/cpython/issues/97725


File: python.info,  Node: Tests<22>,  Next: Build<26>,  Prev: Documentation<22>,  Up: Python 3 12 0 alpha 6

1.24.28.5 Tests
...............

   - gh-102019(1): Fix deadlock on shutdown if
     ‘test_current_{exception,frames}’ fails.  Patch by Jacob Bower.

   - gh-85984(2): Utilize new «winsize» functions from termios in pty
     tests.

   - gh-89792(3): ‘test_tools’ now copies up to 10x less source data to
     a temporary directory during the ‘freeze’ test by ignoring git
     metadata and other artifacts.  It also limits its python build
     parallelism based on os.cpu_count instead of hard coding it as 8
     cores.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102019

   (2) https://github.com/python/cpython/issues/85984

   (3) https://github.com/python/cpython/issues/89792


File: python.info,  Node: Build<26>,  Next: Windows<23>,  Prev: Tests<22>,  Up: Python 3 12 0 alpha 6

1.24.28.6 Build
...............

   - gh-99942(1): On Android, in a static build, python-config in embed
     mode no longer incorrectly reports a library to link to.

   - gh-99942(2): On Android, python.pc now correctly reports the
     library to link to, the same as python-config.sh.

   - gh-100221(3): Fix creating install directories in ‘make
     sharedinstall’ if they exist outside ‘DESTDIR’ already.

   - gh-96821(4): Explicitly mark C extension modules that need defined
     signed integer overflow, and add a configure option *note
     -with-strict-overflow: 1abb.  Patch by Matthias Görgens and
     Shantanu Jain.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99942

   (2) https://github.com/python/cpython/issues/99942

   (3) https://github.com/python/cpython/issues/100221

   (4) https://github.com/python/cpython/issues/96821


File: python.info,  Node: Windows<23>,  Next: macOS<15>,  Prev: Build<26>,  Up: Python 3 12 0 alpha 6

1.24.28.7 Windows
.................

   - gh-102344(1): Implement ‘winreg.QueryValue’ using ‘QueryValueEx’
     and ‘winreg.SetValue’ using ‘SetValueEx’.  Patch by Max Bachmann.

   - gh-101881(2): Handle read and write operations on non-blocking
     pipes properly on Windows.

   - gh-101881(3): Add support for the os.get_blocking() and
     os.set_blocking() functions on Windows.

   - gh-101849(4): Ensures installer will correctly upgrade existing
     ‘py.exe’ launcher installs.

   - gh-101763(5): Updates copy of libffi bundled with Windows installs
     to 3.4.4.

   - gh-101759(6): Update Windows installer to SQLite 3.40.1.

   - gh-101614(7): Correctly handle extensions built against debug
     binaries that reference ‘python3_d.dll’.

   - gh-101196(8): The functions ‘os.path.isdir’, ‘os.path.isfile’,
     ‘os.path.islink’ and ‘os.path.exists’ are now 13% to 28% faster on
     Windows, by making fewer Win32 API calls.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/102344

   (2) https://github.com/python/cpython/issues/101881

   (3) https://github.com/python/cpython/issues/101881

   (4) https://github.com/python/cpython/issues/101849

   (5) https://github.com/python/cpython/issues/101763

   (6) https://github.com/python/cpython/issues/101759

   (7) https://github.com/python/cpython/issues/101614

   (8) https://github.com/python/cpython/issues/101196


File: python.info,  Node: macOS<15>,  Next: C API<25>,  Prev: Windows<23>,  Up: Python 3 12 0 alpha 6

1.24.28.8 macOS
...............

   - gh-101759(1): Update macOS installer to SQLite 3.40.1.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101759


File: python.info,  Node: C API<25>,  Prev: macOS<15>,  Up: Python 3 12 0 alpha 6

1.24.28.9 C API
...............

   - gh-101907(1): Removes use of non-standard C++ extension in public
     header files.

   - gh-99293(2): Document that the Py_TPFLAGS_VALID_VERSION_TAG is an
     internal feature, should not be used, and will be removed.

   - gh-101578(3): Add *note PyErr_GetRaisedException(): 429. and *note
     PyErr_SetRaisedException(): 42c. for saving and restoring the
     current exception.  These functions return and accept a single
     exception object, rather than the triple arguments of the
     now-deprecated *note PyErr_Fetch(): 428. and *note PyErr_Restore():
     42b.  This is less error prone and a bit more efficient.

     Add *note PyException_GetArgs(): 78c. and *note
     PyException_SetArgs(): 78d. as convenience functions for retrieving
     and modifying the *note args: 78e. passed to the exception’s
     constructor.

   - gh-91744(4): Introduced the 'Unstable C API tier', marking APi that
     is allowed to change in minor releases without a deprecation
     period.  See PEP 689(5) for details.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101907

   (2) https://github.com/python/cpython/issues/99293

   (3) https://github.com/python/cpython/issues/101578

   (4) https://github.com/python/cpython/issues/91744

   (5) https://peps.python.org/pep-0689/


File: python.info,  Node: Python 3 12 0 alpha 5,  Next: Python 3 12 0 alpha 4,  Prev: Python 3 12 0 alpha 6,  Up: Changelog

1.24.29 Python 3.12.0 alpha 5
-----------------------------

'Release date: 2023-02-07'

* Menu:

* Security: Security<24>.
* Core and Builtins: Core and Builtins<65>.
* Library: Library<70>.
* Documentation: Documentation<23>.
* Tests: Tests<23>.
* Build: Build<27>.
* Windows: Windows<24>.


File: python.info,  Node: Security<24>,  Next: Core and Builtins<65>,  Up: Python 3 12 0 alpha 5

1.24.29.1 Security
..................

   - gh-99108(1): Replace the builtin *note hashlib: 6c. implementations
     of SHA2-224 and SHA2-256 originally from LibTomCrypt with formally
     verified, side-channel resistant code from the HACL*(2) project.
     The builtins remain a fallback only used when OpenSSL does not
     provide them.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99108

   (2) https://github.com/hacl-star/hacl-star/


File: python.info,  Node: Core and Builtins<65>,  Next: Library<70>,  Prev: Security<24>,  Up: Python 3 12 0 alpha 5

1.24.29.2 Core and Builtins
...........................

   - gh-92173(1): Fix the ‘defs’ and ‘kwdefs’ arguments to *note
     PyEval_EvalCodeEx(): 1ac2. and a reference leak in that function.

   - gh-59956(2): The GILState API is now partially compatible with
     subinterpreters.  Previously, ‘PyThreadState_GET()’ and
     ‘PyGILState_GetThisThreadState()’ would get out of sync, causing
     inconsistent behavior and crashes.

   - gh-101400(3): Fix wrong lineno in exception message on *note
     continue: 180. or *note break: 17f. which are not in a loop.  Patch
     by Donghee Na.

   - gh-101372(4): Fix *note is_normalized(): c3e. to properly handle
     the UCD 3.2.0 cases.  Patch by Donghee Na.

   - gh-101266(5): Fix *note sys.getsizeof(): 1ac3. reporting for *note
     int: 19b. subclasses.

   - gh-101291(6): Refactor the ‘PyLongObject’ struct into a normal
     Python object header and a ‘PyLongValue’ struct.

   - gh-101046(7): Fix a possible memory leak in the parser when raising
     *note MemoryError: 1786.  Patch by Pablo Galindo

   - gh-101037(8): Fix potential memory underallocation issue for
     instances of *note int: 19b. subclasses with value zero.

   - gh-100762(9): Record the (virtual) exception block depth in the
     oparg of *note YIELD_VALUE: 5ba.  Use this to avoid the expensive
     ‘throw()’ when closing generators (and coroutines) that can be
     closed trivially.

   - gh-100982(10): Adds a new ‘COMPARE_AND_BRANCH’ instruction.  This
     is a bit more efficient when performing a comparison immediately
     followed by a branch, and restores the design intent of PEP 659
     that specializations are local to a single instruction.

   - gh-100942(11): Fixed segfault in property.getter/setter/deleter
     that occurred when a property subclass overrode the ‘__new__’
     method to return a non-property instance.

   - gh-100923(12): Remove the ‘mask’ cache entry for the *note
     COMPARE_OP: b63. instruction and embed the mask into the oparg.

   - gh-100892(13): Fix race while iterating over thread states in
     clearing *note threading.local: 1847.  Patch by Kumar Aditya.

   - gh-91351(14): Fix a case where re-entrant imports could corrupt the
     import deadlock detection code and cause a *note KeyError: 5e7. to
     be raised out of ‘importlib/_bootstrap’.  In addition to the
     straightforward cases, this could also happen when garbage
     collection leads to a warning being emitted – as happens when it
     collects an open socket or file)

   - gh-100726(15): Optimize construction of ‘range’ object for medium
     size integers.

   - gh-100712(16): Added option to build cpython with specialization
     disabled, by setting ‘ENABLE_SPECIALIZATION=False’ in ‘opcode’,
     followed by ‘make regen-all’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/92173

   (2) https://github.com/python/cpython/issues/59956

   (3) https://github.com/python/cpython/issues/101400

   (4) https://github.com/python/cpython/issues/101372

   (5) https://github.com/python/cpython/issues/101266

   (6) https://github.com/python/cpython/issues/101291

   (7) https://github.com/python/cpython/issues/101046

   (8) https://github.com/python/cpython/issues/101037

   (9) https://github.com/python/cpython/issues/100762

   (10) https://github.com/python/cpython/issues/100982

   (11) https://github.com/python/cpython/issues/100942

   (12) https://github.com/python/cpython/issues/100923

   (13) https://github.com/python/cpython/issues/100892

   (14) https://github.com/python/cpython/issues/91351

   (15) https://github.com/python/cpython/issues/100726

   (16) https://github.com/python/cpython/issues/100712


File: python.info,  Node: Library<70>,  Next: Documentation<23>,  Prev: Core and Builtins<65>,  Up: Python 3 12 0 alpha 5

1.24.29.3 Library
.................

   - bpo-32780(1): Inter-field padding is now inserted into the PEP3118
     format strings obtained from *note ctypes.Structure: 1e5. objects,
     reflecting their true representation in memory.

   - gh-101541(2): [Enum] - fix psuedo-flag creation

   - gh-101570(3): Upgrade pip wheel bundled with ensurepip (pip 23.0)

   - gh-101323(4): Fix a bug where errors where not thrown by
     zlib._ZlibDecompressor if encountered during decompressing.

   - gh-101317(5): Add 'ssl_shutdown_timeout' parameter for *note
     asyncio.StreamWriter.start_tls(): 81a.

   - gh-101326(6): Fix regression when passing ‘None’ as second or third
     argument to ‘FutureIter.throw’.

   - gh-92123(7): Adapt the ‘_elementtree’ extension module to
     multi-phase init ( PEP 489(8)).  Patches by Erlend E. Aasland.

   - gh-100795(9): Avoid potential unexpected ‘freeaddrinfo’ call
     (double free) in *note socket: d1. when when a libc ‘getaddrinfo()’
     implementation leaves garbage in an output pointer when returning
     an error.  Original patch by Sergey G. Brester.

   - gh-101143(10): Remove unused references to *note TimerHandle: 1ac5.
     in ‘asyncio.base_events.BaseEventLoop._add_callback’.

   - gh-101144(11): Make *note zipfile.Path.open(): 18ef. and *note
     zipfile.Path.read_text(): 1ac6. also accept ‘encoding’ as a
     positional argument.  This was the behavior in Python 3.9 and
     earlier.  3.10 introduced a regression where supplying it as a
     positional argument would lead to a *note TypeError: 198.

   - gh-94518(12): Group-related variables of ‘_posixsubprocess’ module
     are renamed to stress that supplementary group affinity is added to
     a fork, not replace the inherited ones.  Patch by Oleg Iarygin.

   - gh-101015(13): Fix *note typing.get_type_hints(): 8c1. on
     ‘'*tuple[...]'’ and ‘*tuple[...]’.  It must not drop the ‘Unpack’
     part.

   - gh-101000(14): Add *note os.path.splitroot(): 6cc, which splits a
     path into a 3-item tuple ‘(drive, root, tail)’.  This new function
     is used by *note pathlib: a8. to improve the performance of path
     construction by up to a third.

   - gh-100573(15): Fix a Windows *note asyncio: b. bug with named pipes
     where a client doing ‘os.stat()’ on the pipe would cause an error
     in the server that disabled serving future requests.

   - gh-39615(16): *note warnings.warn(): 1720. now has the ability to
     skip stack frames based on code filename prefix rather than only a
     numeric ‘stacklevel’ via the new ‘skip_file_prefixes’ keyword
     argument.

   - gh-100750(17): pass encoding kwarg to subprocess in platform

   - gh-100160(18): Emit a deprecation warning in
     ‘asyncio.DefaultEventLoopPolicy.get_event_loop()’ if there is no
     current event loop set and it decides to create one.

   - gh-96290(19): Fix handling of partial and invalid UNC drives in
     ‘ntpath.splitdrive()’, and in ‘ntpath.normpath()’ on non-Windows
     systems.  Paths such as “\server” and “\” are now considered by
     ‘splitdrive()’ to contain only a drive, and consequently are not
     modified by ‘normpath()’ on non-Windows systems.  The behaviour of
     ‘normpath()’ on Windows systems is unaffected, as native OS APIs
     are used.  Patch by Eryk Sun, with contributions by Barney Gale.

   - gh-99952(20): Fix a reference undercounting issue in *note
     ctypes.Structure: 1e5. with ‘from_param()’ results larger than a C
     pointer.

   - gh-67790(21): Add float-style formatting support for *note
     fractions.Fraction: 213. instances.

   - gh-99266(22): Preserve more detailed error messages in *note
     ctypes: 2e.

   - gh-86682(23): Ensure runtime-created collections have the correct
     module name using the newly added (internal) *note
     sys._getframemodulename(): 1ac7.

   - gh-88597(24): *note uuid: 116. now has a command line interface.
     Try ‘python -m uuid -h’.

   - gh-60580(25): ‘ctypes.wintypes.BYTE’ definition changed from *note
     c_byte: 1ac8. to *note c_ubyte: 1ac9. to match Windows SDK. Patch
     by Anatoly Techtonik and Oleg Iarygin.

   - gh-94518(26): ‘_posixsubprocess’ now initializes all UID and GID
     variables using a reserved ‘-1’ value instead of a separate flag.
     Patch by Oleg Iarygin.

   - bpo-38941(27): The *note xml.etree.ElementTree: 12b. module now
     emits *note DeprecationWarning: 1a3. when testing the truth value
     of an *note xml.etree.ElementTree.Element: 363.  Before, the Python
     implementation emitted *note FutureWarning: 659, and the C
     implementation emitted nothing.

   - bpo-40077(28): Convert ‘elementtree’ types to heap types.  Patch by
     Erlend E. Aasland.

   - bpo-29847(29): Fix a bug where *note pathlib.Path: 266. accepted
     and ignored keyword arguments.  Patch provided by Yurii Karabas.

   - gh-77772(30): *note ctypes.CDLL: bde, *note ctypes.OleDLL: 1aca,
     *note ctypes.WinDLL: 1acb, and *note ctypes.PyDLL: 1acc. now accept
     *note path-like objects: 5a1. as their ‘name’ argument.  Patch by
     Robert Hoelzl.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32780

   (2) https://github.com/python/cpython/issues/101541

   (3) https://github.com/python/cpython/issues/101570

   (4) https://github.com/python/cpython/issues/101323

   (5) https://github.com/python/cpython/issues/101317

   (6) https://github.com/python/cpython/issues/101326

   (7) https://github.com/python/cpython/issues/92123

   (8) https://peps.python.org/pep-0489/

   (9) https://github.com/python/cpython/issues/100795

   (10) https://github.com/python/cpython/issues/101143

   (11) https://github.com/python/cpython/issues/101144

   (12) https://github.com/python/cpython/issues/94518

   (13) https://github.com/python/cpython/issues/101015

   (14) https://github.com/python/cpython/issues/101000

   (15) https://github.com/python/cpython/issues/100573

   (16) https://github.com/python/cpython/issues/39615

   (17) https://github.com/python/cpython/issues/100750

   (18) https://github.com/python/cpython/issues/100160

   (19) https://github.com/python/cpython/issues/96290

   (20) https://github.com/python/cpython/issues/99952

   (21) https://github.com/python/cpython/issues/67790

   (22) https://github.com/python/cpython/issues/99266

   (23) https://github.com/python/cpython/issues/86682

   (24) https://github.com/python/cpython/issues/88597

   (25) https://github.com/python/cpython/issues/60580

   (26) https://github.com/python/cpython/issues/94518

   (27) https://bugs.python.org/issue?@action=redirect&bpo=38941

   (28) https://bugs.python.org/issue?@action=redirect&bpo=40077

   (29) https://bugs.python.org/issue?@action=redirect&bpo=29847

   (30) https://github.com/python/cpython/issues/77772


File: python.info,  Node: Documentation<23>,  Next: Tests<23>,  Prev: Library<70>,  Up: Python 3 12 0 alpha 5

1.24.29.4 Documentation
.......................

   - gh-88324(1): Reword *note subprocess: dc. to emphasize default
     behavior of 'stdin', 'stdout', and 'stderr' arguments.  Remove
     inaccurate statement about child file handle inheritance.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/88324


File: python.info,  Node: Tests<23>,  Next: Build<27>,  Prev: Documentation<23>,  Up: Python 3 12 0 alpha 5

1.24.29.5 Tests
...............

   - gh-101334(1): ‘test_tarfile’ has been updated to pass when run as a
     high UID.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101334


File: python.info,  Node: Build<27>,  Next: Windows<24>,  Prev: Tests<23>,  Up: Python 3 12 0 alpha 5

1.24.29.6 Build
...............

   - gh-101282(1): Update BOLT configuration not to use deprecated usage
     of ‘--split functions’.  Patch by Donghee Na.

   - gh-101522(2): Allow overriding Windows dependencies versions and
     paths using MSBuild properties.

   - gh-77532(3): Minor fixes to allow building with
     ‘PlatformToolset=ClangCL’ on Windows.

   - gh-101152(4): In accordance with PEP 699(5), the ‘ma_version_tag’
     field in *note PyDictObject: 64f. is deprecated for extension
     modules.  Accessing this field will generate a compiler warning at
     compile time.  This field will be removed in Python 3.14.

   - gh-100340(6): Allows -Wno-int-conversion for wasm-sdk 17 and
     onwards, thus enables building WASI builds once against the latest
     sdk.

   - gh-101060(7): Conditionally add ‘-fno-reorder-blocks-and-partition’
     in configure.  Effectively fixes ‘--enable-bolt’ when using Clang,
     as this appears to be a GCC-only flag.

   - gh-98705(8): ‘__bool__’ is defined in AIX system header files which
     breaks the build in AIX, so undefine it.

   - gh-98636(9): Fix a regression in detecting ‘gdbm_compat’ library
     for the ‘_gdbm’ module build.

   - gh-96305(10): ‘_aix_support’ now uses a simple code to get platform
     details rather than the now non-existent ‘_bootsubprocess’ during
     bootstrap.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101282

   (2) https://github.com/python/cpython/issues/101522

   (3) https://github.com/python/cpython/issues/77532

   (4) https://github.com/python/cpython/issues/101152

   (5) https://peps.python.org/pep-0699/

   (6) https://github.com/python/cpython/issues/100340

   (7) https://github.com/python/cpython/issues/101060

   (8) https://github.com/python/cpython/issues/98705

   (9) https://github.com/python/cpython/issues/98636

   (10) https://github.com/python/cpython/issues/96305


File: python.info,  Node: Windows<24>,  Prev: Build<27>,  Up: Python 3 12 0 alpha 5

1.24.29.7 Windows
.................

   - gh-101543(1): Ensure the install path in the registry is only used
     when the standard library hasn’t been located in any other way.

   - gh-101467(2): The ‘py.exe’ launcher now correctly filters when only
     a single runtime is installed.  It also correctly handles prefix
     matches on tags so that ‘-3.1’ does not match ‘3.11’, but would
     still match ‘3.1-32’.

   - gh-99834(3): Updates bundled copy of Tcl/Tk to 8.6.13.0

   - gh-101135(4): Restore ability to launch older 32-bit versions from
     the ‘py.exe’ launcher when both 32-bit and 64-bit installs of the
     same version are available.

   - gh-82052(5): Fixed an issue where writing more than 32K of Unicode
     output to the console screen in one go can result in mojibake.

   - gh-100320(6): Ensures the ‘PythonPath’ registry key from an install
     is used when launching from a different copy of Python that relies
     on an existing install to provide a copy of its modules and
     standard library.

   - gh-100247(7): Restores support for the ‘py.exe’ launcher finding
     shebang commands in its configuration file using the full command
     name.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/101543

   (2) https://github.com/python/cpython/issues/101467

   (3) https://github.com/python/cpython/issues/99834

   (4) https://github.com/python/cpython/issues/101135

   (5) https://github.com/python/cpython/issues/82052

   (6) https://github.com/python/cpython/issues/100320

   (7) https://github.com/python/cpython/issues/100247


File: python.info,  Node: Python 3 12 0 alpha 4,  Next: Python 3 12 0 alpha 3,  Prev: Python 3 12 0 alpha 5,  Up: Changelog

1.24.30 Python 3.12.0 alpha 4
-----------------------------

'Release date: 2023-01-10'

* Menu:

* Core and Builtins: Core and Builtins<66>.
* Library: Library<71>.
* Core and Builtins: Core and Builtins<67>.
* Library: Library<72>.
* Core and Builtins: Core and Builtins<68>.
* Library: Library<73>.
* Documentation: Documentation<24>.
* Tests: Tests<24>.
* Build: Build<28>.
* Windows: Windows<25>.
* macOS: macOS<16>.
* Tools/Demos: Tools/Demos<22>.
* C API: C API<26>.


File: python.info,  Node: Core and Builtins<66>,  Next: Library<71>,  Up: Python 3 12 0 alpha 4

1.24.30.1 Core and Builtins
...........................

   - gh-100776(1): Fix misleading default value in *note input():
     14e0.”s ‘__text_signature__’.

   - gh-99005(2): Remove ‘UNARY_POSITIVE’, ‘ASYNC_GEN_WRAP’ and
     ‘LIST_TO_TUPLE’, replacing them with intrinsics.

   - gh-99005(3): Add new *note CALL_INTRINSIC_1: 708. instruction.
     Remove ‘IMPORT_STAR’, ‘PRINT_EXPR’ and ‘STOPITERATION_ERROR’,
     replacing them with the *note CALL_INTRINSIC_1: 708. instruction.

   - gh-100288(4): Remove the LOAD_ATTR_METHOD_WITH_DICT specialized
     instruction.  Stats show it is not useful.

   - gh-100720(5): Added ‘_PyFrame_NumSlotsForCodeObject’, which returns
     the number of slots needed in a frame for a given code object.

   - gh-100719(6): Removed the co_nplaincellvars field from the code
     object, as it is redundant.

   - gh-100637(7): Fix ‘int.__sizeof__()’ calculation to include the
     1-element ‘ob_digit’ array for ‘0’ and ‘False’.

   - gh-100649(8): Update the native_thread_id field of PyThreadState
     after fork.

   - gh-100126(9): Fix an issue where «incomplete» frames could be
     briefly visible to C code while other frames are being torn down,
     possibly resulting in corruption or hard crashes of the interpreter
     while running finalizers.

   - gh-87447(10): Fix *note SyntaxError: 18e. on comprehension rebind
     checking with names that are not actually redefined.

     Now reassigning ‘b’ in ‘[(b := 1) for a, b.prop in some_iter]’ is
     allowed.  Reassigning ‘a’ is still disallowed as per PEP 572(11).

   - gh-100268(12): Add *note int.is_integer(): 1ad3. to improve duck
     type compatibility between *note int: 19b. and *note float: 196.

   - gh-100425(13): Improve the accuracy of ‘sum()’ with compensated
     summation.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100776

   (2) https://github.com/python/cpython/issues/99005

   (3) https://github.com/python/cpython/issues/99005

   (4) https://github.com/python/cpython/issues/100288

   (5) https://github.com/python/cpython/issues/100720

   (6) https://github.com/python/cpython/issues/100719

   (7) https://github.com/python/cpython/issues/100637

   (8) https://github.com/python/cpython/issues/100649

   (9) https://github.com/python/cpython/issues/100126

   (10) https://github.com/python/cpython/issues/87447

   (11) https://peps.python.org/pep-0572/

   (12) https://github.com/python/cpython/issues/100268

   (13) https://github.com/python/cpython/issues/100425


File: python.info,  Node: Library<71>,  Next: Core and Builtins<67>,  Prev: Core and Builtins<66>,  Up: Python 3 12 0 alpha 4

1.24.30.2 Library
.................

   - gh-100374(1): Fix incorrect result and delay in *note
     socket.getfqdn(): 1ad5.  Patch by Dominic Socular.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100374


File: python.info,  Node: Core and Builtins<67>,  Next: Library<72>,  Prev: Library<71>,  Up: Python 3 12 0 alpha 4

1.24.30.3 Core and Builtins
...........................

   - gh-100357(1): Convert ‘vars’, ‘dir’, ‘next’, ‘getattr’, and ‘iter’
     to argument clinic.

   - gh-100117(2): Improve the output of *note codeobject.co_lines():
     350. by emitting only one entry for each line range.

   - gh-90043(3): Handle NaNs when specializing *note COMPARE_OP: b63.
     for *note float: 196. values.

   - gh-100222(4): Redefine the ‘_Py_CODEUNIT’ typedef as a union to
     describe its layout to the C compiler, avoiding type punning and
     improving clarity.

   - gh-99955(5): Internal compiler functions (in compile.c) now
     consistently return -1 on error and 0 on success.

   - gh-100188(6): The ‘BINARY_SUBSCR_LIST_INT’ and
     ‘BINARY_SUBSCR_TUPLE_INT’ instructions are no longer used for
     negative integers because those instructions always miss when
     encountering negative integers.

   - gh-99110(7): Initialize frame->previous in frameobject.c to fix a
     segmentation fault when accessing frames created by *note
     PyFrame_New(): 1ad7.

   - gh-94155(8): Improved the hashing algorithm for code objects,
     mitigating some hash collisions.

   - gh-99540(9): ‘None’ now hashes to a constant value.  This is not a
     requirements change.

   - gh-100143(10): When built with ‘--enable-pystats’, stats collection
     is now off by default.  To enable it early at startup, pass the
     ‘-Xpystats’ flag.  Stats are now always dumped, even if switched
     off.

   - gh-100146(11): Improve ‘BUILD_LIST’ opcode so that it works
     similarly to the ‘BUILD_TUPLE’ opcode, by stealing references from
     the stack rather than repeatedly using stack operations to set list
     elements.  Implementation details are in a new private API
     ‘_PyList_FromArraySteal()’.

   - gh-100110(12): Specialize ‘FOR_ITER’ for tuples.

   - gh-100050(13): Honor existing errors obtained when searching for
     mismatching parentheses in the tokenizer.  Patch by Pablo Galindo

   - gh-92216(14): Improve the performance of *note hasattr(): 6fa. for
     type objects with a missing attribute.

   - gh-99582(15): Freeze *note zipimport: 138. module into
     ‘_bootstrap_python’.

   - gh-99554(16): Pack debugging location tables more efficiently
     during bytecode compilation.

   - gh-98522(17): Add an internal version number to code objects, to
     give better versioning of inner functions and comprehensions, and
     thus better specialization of those functions.  This change is
     invisible to both Python and C extensions.

   - gh-94603(18): Improve performance of ‘list.pop’ for small lists.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100357

   (2) https://github.com/python/cpython/issues/100117

   (3) https://github.com/python/cpython/issues/90043

   (4) https://github.com/python/cpython/issues/100222

   (5) https://github.com/python/cpython/issues/99955

   (6) https://github.com/python/cpython/issues/100188

   (7) https://github.com/python/cpython/issues/99110

   (8) https://github.com/python/cpython/issues/94155

   (9) https://github.com/python/cpython/issues/99540

   (10) https://github.com/python/cpython/issues/100143

   (11) https://github.com/python/cpython/issues/100146

   (12) https://github.com/python/cpython/issues/100110

   (13) https://github.com/python/cpython/issues/100050

   (14) https://github.com/python/cpython/issues/92216

   (15) https://github.com/python/cpython/issues/99582

   (16) https://github.com/python/cpython/issues/99554

   (17) https://github.com/python/cpython/issues/98522

   (18) https://github.com/python/cpython/issues/94603


File: python.info,  Node: Library<72>,  Next: Core and Builtins<68>,  Prev: Core and Builtins<67>,  Up: Python 3 12 0 alpha 4

1.24.30.4 Library
.................

   - gh-89051(1): Add *note ssl.OP_LEGACY_SERVER_CONNECT: 1ad9.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89051


File: python.info,  Node: Core and Builtins<68>,  Next: Library<73>,  Prev: Library<72>,  Up: Python 3 12 0 alpha 4

1.24.30.5 Core and Builtins
...........................

   - bpo-32782(1): ‘ctypes’ arrays of length 0 now report a correct
     itemsize when a ‘memoryview’ is constructed from them, rather than
     always giving a value of 0.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32782


File: python.info,  Node: Library<73>,  Next: Documentation<24>,  Prev: Core and Builtins<68>,  Up: Python 3 12 0 alpha 4

1.24.30.6 Library
.................

   - gh-100833(1): Speed up *note math.fsum(): 15db. by removing
     defensive ‘volatile’ qualifiers.

   - gh-100805(2): Modify *note random.choice(): 1438. implementation to
     once again work with NumPy arrays.

   - gh-100813(3): Add ‘socket.IP_PKTINFO’ constant.

   - gh-100792(4): Make *note email.message.Message.__contains__():
     1adc. twice as fast.

   - gh-91851(5): Microoptimizations for *note
     fractions.Fraction.__round__(): 1add, *note
     fractions.Fraction.__ceil__(): 1ade. and *note
     fractions.Fraction.__floor__(): 1adf.

   - gh-90104(6): Avoid RecursionError on ‘repr’ if a dataclass field
     definition has a cyclic reference.

   - gh-100689(7): Fix crash in ‘pyexpat’ by statically allocating
     ‘PyExpat_CAPI’ capsule.

   - gh-100740(8): Fix ‘unittest.mock.Mock’ not respecting the spec for
     attribute names prefixed with ‘assert’.

   - gh-91219(9): Change ‘SimpleHTTPRequestHandler’ to support
     subclassing to provide a different set of index file names instead
     of using ‘__init__’ parameters.

   - gh-100690(10): ‘Mock’ objects which are not unsafe will now raise
     an ‘AttributeError’ when accessing an attribute that matches the
     name of an assertion but without the prefix ‘assert_’, e.g.
     accessing ‘called_once’ instead of ‘assert_called_once’.  This is
     in addition to this already happening for accessing attributes with
     prefixes ‘assert’, ‘assret’, ‘asert’, ‘aseert’, and ‘assrt’.

   - gh-89727(11): Simplify and optimize *note os.walk(): 6d1. by using
     *note isinstance(): 2ad. checks to check the top of the stack.

   - gh-100485(12): Add math.sumprod() to compute the sum of products.

   - gh-86508(13): Fix *note asyncio.open_connection(): d10. to skip
     binding to local addresses of different family.  Patch by Kumar
     Aditya.

   - gh-97930(14): ‘importlib.resources.files’ now accepts a module as
     an anchor instead of only accepting packages.  If a module is
     passed, resources are resolved adjacent to that module (in the same
     package or at the package root).  The parameter was renamed from
     ‘package’ to ‘anchor’ with a compatibility shim for those passing
     by keyword.  Additionally, the new ‘anchor’ parameter is now
     optional and will default to the caller’s module.

   - gh-100585(15): Fixed a bug where importlib.resources.as_file was
     leaving file pointers open

   - gh-100562(16): Improve performance of *note
     pathlib.Path.absolute(): 1a0e. by nearly 2x.  This comes at the
     cost of a performance regression in *note pathlib.Path.cwd(): 1a83,
     which is generally used less frequently in user code.

   - gh-100519(17): Small simplification of
     ‘http.cookiejar.eff_request_host()’ that improves readability and
     better matches the RFC wording.

   - gh-100287(18): Fix the interaction of *note unittest.mock.seal():
     d9c. with *note unittest.mock.AsyncMock: c40.

   - gh-100488(19): Add ‘Fraction.is_integer()’ to check whether a *note
     fractions.Fraction: 213. is an integer.  This improves duck type
     compatibility with *note float: 196. and *note int: 19b.

   - gh-100474(20): *note http.server: 76. now checks that an index page
     is actually a regular file before trying to serve it.  This avoids
     issues with directories named ‘index.html’.

   - gh-100363(21): Speed up *note asyncio.get_running_loop(): d03. by
     removing redundant ‘getpid’ checks.  Patch by Kumar Aditya.

   - gh-78878(22): Fix crash when creating an instance of
     ‘_ctypes.CField’.

   - gh-100348(23): Fix ref cycle in ‘asyncio._SelectorSocketTransport’
     by removing ‘_read_ready_cb’ in ‘close’.

   - gh-100344(24): Provide C implementation for *note
     asyncio.current_task(): 6a6. for a 4x-6x speedup.

   - gh-100272(25): Fix JSON serialization of OrderedDict.  It now
     preserves the order of keys.

   - gh-83076(26): Instantiation of ‘Mock()’ and ‘AsyncMock()’ is now
     3.8x faster.

   - gh-100234(27): Set a default value of 1.0 for the ‘lambd’ parameter
     in random.expovariate().

   - gh-100228(28): A *note DeprecationWarning: 1a3. may be raised when
     *note os.fork(): 4b6. or *note os.forkpty(): 4b7. is called from
     multi-threaded processes.  Forking with threads is unsafe and can
     cause deadlocks, crashes and subtle problems.  Lack of a warning
     does not indicate that the fork call was actually safe, as Python
     may not be aware of all threads.

   - gh-100039(29): Improve signatures for enums and flags.

   - gh-100133(30): Fix regression in *note asyncio: b. where a
     subprocess would sometimes lose data received from pipe.

   - bpo-44592(31): Fixes inconsistent handling of case sensitivity of
     'extrasaction' arg in *note csv.DictWriter: 1406.

   - gh-100098(32): Fix ‘tuple’ subclasses being cast to ‘tuple’ when
     used as enum values.

   - gh-85432(33): Rename the 'fmt' parameter of the pure-Python
     implementation of *note datetime.time.strftime(): 1ae0. to
     'format'.  Rename the 't' parameter of *note
     datetime.datetime.fromtimestamp(): 713. to 'timestamp'.  These
     changes mean the parameter names in the pure-Python implementation
     now match the parameter names in the C implementation.  Patch by
     Alex Waygood.

   - gh-98778(34): Update *note HTTPError: 11e0. to be initialized
     properly, even if the ‘fp’ is ‘None’.  Patch by Donghee Na.

   - gh-99925(35): Unify error messages in JSON serialization between
     ‘json.dumps(float('nan'), allow_nan=False)’ and
     ‘json.dumps(float('nan'), allow_nan=False, indent=<SOMETHING>)’.
     Now both include the representation of the value that could not be
     serialized.

   - gh-89727(36): Fix issue with *note os.walk(): 6d1. where a *note
     RecursionError: f6a. would occur on deep directory structures by
     adjusting the implementation of *note os.walk(): 6d1. to be
     iterative instead of recursive.

   - gh-94943(37): Add *note Dataclass support: 1ae1. to the *note Enum:
     843. *note __repr__(): 1ae2.  When inheriting from a *note
     dataclass: 4e2, only show the field names in the value section of
     the member *note repr(): 1c1, and not the dataclass” class name.

   - gh-83035(38): Fix *note inspect.getsource(): 17ab. handling of
     decorator calls with nested parentheses.

   - gh-99576(39): Fix ‘.save()’ method for ‘LWPCookieJar’ and
     ‘MozillaCookieJar’: saved file was not truncated on repeated save.

   - gh-94912(40): Add *note inspect.markcoroutinefunction(): 6b9.
     decorator which manually marks a function as a coroutine for the
     benefit of ‘iscoroutinefunction()’.

   - gh-99509(41): Add PEP 585(42) support for
     ‘multiprocessing.queues.Queue’.

   - gh-99482(43): Remove ‘Jython’ partial compatibility code from
     several stdlib modules.

   - gh-99433(44): Fix *note doctest: 3e. failure on *note
     types.MethodWrapperType: 85c. in modules.

   - gh-85267(45): Several improvements to *note inspect.signature():
     22f.”s handling of ‘__text_signature’.  - Fixes a case where *note
     inspect.signature(): 22f. dropped parameters - Fixes a case where
     *note inspect.signature(): 22f. raised *note tokenize.TokenError:
     765. - Allows *note inspect.signature(): 22f. to understand
     defaults involving binary operations of constants - *note
     inspect.signature(): 22f. is documented as only raising *note
     TypeError: 198. or *note ValueError: 2ec, but sometimes raised
     *note RuntimeError: 244.  These cases now raise *note ValueError:
     2ec. - Removed a dead code path

   - gh-91166(46): *note asyncio: b. is optimized to avoid excessive
     copying when writing to socket and use *note sendmsg(): 6a2. if the
     platform supports it.  Patch by Kumar Aditya.

   - gh-98030(47): Add missing TCP socket options from Linux:
     ‘TCP_MD5SIG’, ‘TCP_THIN_LINEAR_TIMEOUTS’, ‘TCP_THIN_DUPACK’,
     ‘TCP_REPAIR’, ‘TCP_REPAIR_QUEUE’, ‘TCP_QUEUE_SEQ’,
     ‘TCP_REPAIR_OPTIONS’, ‘TCP_TIMESTAMP’, ‘TCP_CC_INFO’,
     ‘TCP_SAVE_SYN’, ‘TCP_SAVED_SYN’, ‘TCP_REPAIR_WINDOW’,
     ‘TCP_FASTOPEN_CONNECT’, ‘TCP_ULP’, ‘TCP_MD5SIG_EXT’,
     ‘TCP_FASTOPEN_KEY’, ‘TCP_FASTOPEN_NO_COOKIE’,
     ‘TCP_ZEROCOPY_RECEIVE’, ‘TCP_INQ’, ‘TCP_TX_DELAY’.

   - gh-88500(48): Reduced the memory usage of *note
     urllib.parse.unquote(): 1ae3. and *note
     urllib.parse.unquote_to_bytes(): 1ae4. on large values.

   - gh-96127(49): ‘inspect.signature’ was raising ‘TypeError’ on call
     with mock objects.  Now it correctly returns ‘(*args, **kwargs)’ as
     inferred signature.

   - gh-95882(50): Fix a 3.11 regression in *note asynccontextmanager():
     d21, which caused it to propagate exceptions with incorrect
     tracebacks and fix a 3.11 regression in *note contextmanager():
     140a, which caused it to propagate exceptions with incorrect
     tracebacks for *note StopIteration: df7.

   - gh-78707(51): Deprecate passing more than one positional argument
     to *note pathlib.PurePath.relative_to(): 2fd. and *note
     is_relative_to(): 2fe.

   - gh-92122(52): Fix reStructuredText syntax errors in docstrings in
     the *note enum: 5a. module.

   - gh-91851(53): Optimize the *note Fraction: 213. arithmetics for
     small components.

   - bpo-24132(54): Make *note pathlib.PurePath: 6ce. and *note Path:
     266. subclassable (private to start).  Previously, attempting to
     instantiate a subclass resulted in an *note AttributeError: 5f0.
     being raised.  Patch by Barney Gale.

   - bpo-40447(55): Accept *note os.PathLike: e4d. (such as *note
     pathlib.Path: 266.) in the ‘stripdir’ arguments of *note
     compileall.compile_file(): fe3. and *note compileall.compile_dir():
     d1d.

   - bpo-36880(56): Fix a reference counting issue when a *note ctypes:
     2e. callback with return type *note py_object: 1f3. returns ‘None’,
     which could cause crashes.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100833

   (2) https://github.com/python/cpython/issues/100805

   (3) https://github.com/python/cpython/issues/100813

   (4) https://github.com/python/cpython/issues/100792

   (5) https://github.com/python/cpython/issues/91851

   (6) https://github.com/python/cpython/issues/90104

   (7) https://github.com/python/cpython/issues/100689

   (8) https://github.com/python/cpython/issues/100740

   (9) https://github.com/python/cpython/issues/91219

   (10) https://github.com/python/cpython/issues/100690

   (11) https://github.com/python/cpython/issues/89727

   (12) https://github.com/python/cpython/issues/100485

   (13) https://github.com/python/cpython/issues/86508

   (14) https://github.com/python/cpython/issues/97930

   (15) https://github.com/python/cpython/issues/100585

   (16) https://github.com/python/cpython/issues/100562

   (17) https://github.com/python/cpython/issues/100519

   (18) https://github.com/python/cpython/issues/100287

   (19) https://github.com/python/cpython/issues/100488

   (20) https://github.com/python/cpython/issues/100474

   (21) https://github.com/python/cpython/issues/100363

   (22) https://github.com/python/cpython/issues/78878

   (23) https://github.com/python/cpython/issues/100348

   (24) https://github.com/python/cpython/issues/100344

   (25) https://github.com/python/cpython/issues/100272

   (26) https://github.com/python/cpython/issues/83076

   (27) https://github.com/python/cpython/issues/100234

   (28) https://github.com/python/cpython/issues/100228

   (29) https://github.com/python/cpython/issues/100039

   (30) https://github.com/python/cpython/issues/100133

   (31) https://bugs.python.org/issue?@action=redirect&bpo=44592

   (32) https://github.com/python/cpython/issues/100098

   (33) https://github.com/python/cpython/issues/85432

   (34) https://github.com/python/cpython/issues/98778

   (35) https://github.com/python/cpython/issues/99925

   (36) https://github.com/python/cpython/issues/89727

   (37) https://github.com/python/cpython/issues/94943

   (38) https://github.com/python/cpython/issues/83035

   (39) https://github.com/python/cpython/issues/99576

   (40) https://github.com/python/cpython/issues/94912

   (41) https://github.com/python/cpython/issues/99509

   (42) https://peps.python.org/pep-0585/

   (43) https://github.com/python/cpython/issues/99482

   (44) https://github.com/python/cpython/issues/99433

   (45) https://github.com/python/cpython/issues/85267

   (46) https://github.com/python/cpython/issues/91166

   (47) https://github.com/python/cpython/issues/98030

   (48) https://github.com/python/cpython/issues/88500

   (49) https://github.com/python/cpython/issues/96127

   (50) https://github.com/python/cpython/issues/95882

   (51) https://github.com/python/cpython/issues/78707

   (52) https://github.com/python/cpython/issues/92122

   (53) https://github.com/python/cpython/issues/91851

   (54) https://bugs.python.org/issue?@action=redirect&bpo=24132

   (55) https://bugs.python.org/issue?@action=redirect&bpo=40447

   (56) https://bugs.python.org/issue?@action=redirect&bpo=36880


File: python.info,  Node: Documentation<24>,  Next: Tests<24>,  Prev: Library<73>,  Up: Python 3 12 0 alpha 4

1.24.30.7 Documentation
.......................

   - gh-100616(1): Document existing ‘attr’ parameter to *note
     curses.window.vline(): 1ae6. function in *note curses: 2f.

   - gh-100472(2): Remove claim in documentation that the ‘stripdir’,
     ‘prependdir’ and ‘limit_sl_dest’ parameters of *note
     compileall.compile_dir(): d1d. and *note compileall.compile_file():
     fe3. could be *note bytes: 192.

   - bpo-25377(3): Clarify use of octal format of mode argument in
     help(os.chmod) as well as help(os.fchmod)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100616

   (2) https://github.com/python/cpython/issues/100472

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25377


File: python.info,  Node: Tests<24>,  Next: Build<28>,  Prev: Documentation<24>,  Up: Python 3 12 0 alpha 4

1.24.30.8 Tests
...............

   - gh-100454(1): Start running SSL tests with OpenSSL 3.1.0-beta1.

   - gh-100086(2): The Python test runner (libregrtest) now logs Python
     build information like «debug» vs «release» build, or LTO and PGO
     optimizations.  Patch by Victor Stinner.

   - gh-93018(3): Make two tests forgiving towards host system libexpat
     with backported security fixes applied.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100454

   (2) https://github.com/python/cpython/issues/100086

   (3) https://github.com/python/cpython/issues/93018


File: python.info,  Node: Build<28>,  Next: Windows<25>,  Prev: Tests<24>,  Up: Python 3 12 0 alpha 4

1.24.30.9 Build
...............

   - gh-100540(1): Removed the ‘--with-system-ffi’ ‘configure’ option;
     ‘libffi’ must now always be supplied by the system on all
     non-Windows platforms.  The option has had no effect on non-Darwin
     platforms for several releases, and in 3.11 only had the
     non-obvious effect of invoking ‘pkg-config’ to find ‘libffi’ and
     never setting ‘-DUSING_APPLE_OS_LIBFFI’.  Now on Darwin platforms
     ‘configure’ will first check for the OS ‘libffi’ and then fall back
     to the same processing as other platforms if it is not found.

   - gh-88267(2): Avoid exporting Python symbols in linked Windows
     applications when the core is built as static.

   - bpo-41916(3): Allow override of ac_cv_cxx_thread so that cross
     compiled python can set -pthread for CXX.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100540

   (2) https://github.com/python/cpython/issues/88267

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41916


File: python.info,  Node: Windows<25>,  Next: macOS<16>,  Prev: Build<28>,  Up: Python 3 12 0 alpha 4

1.24.30.10 Windows
..................

   - gh-100180(1): Update Windows installer to OpenSSL 1.1.1s

   - gh-99191(2): Use ‘_MSVC_LANG >= 202002L’ instead of less-precise
     ‘_MSC_VER >=1929’ to more accurately test for C++20 support in
     ‘PC/_wmimodule.cpp’.

   - gh-79218(3): Define ‘MS_WIN64’ for Mingw-w64 64bit, fix cython
     compilation failure.

   - gh-99941(4): Ensure that *note asyncio.Protocol.data_received():
     1aea. receives an immutable *note bytes: 192. object (as
     documented), instead of *note bytearray: 344.

   - bpo-43984(5): *note winreg.SetValueEx(): 1aeb. now leaves the
     target value untouched in the case of conversion errors.
     Previously, ‘-1’ would be written in case of such errors.

   - bpo-34816(6): ‘hasattr(ctypes.windll, 'nonexistant')’ now returns
     ‘False’ instead of raising *note OSError: 2c0.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100180

   (2) https://github.com/python/cpython/issues/99191

   (3) https://github.com/python/cpython/issues/79218

   (4) https://github.com/python/cpython/issues/99941

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43984

   (6) https://bugs.python.org/issue?@action=redirect&bpo=34816


File: python.info,  Node: macOS<16>,  Next: Tools/Demos<22>,  Prev: Windows<25>,  Up: Python 3 12 0 alpha 4

1.24.30.11 macOS
................

   - gh-100180(1): Update macOS installer to OpenSSL 1.1.1s

   - gh-100540(2): Removed obsolete ‘dlfcn.h’ shim from the ‘_ctypes’
     extension module, which has not been necessary since Mac OS X 10.2.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100180

   (2) https://github.com/python/cpython/issues/100540


File: python.info,  Node: Tools/Demos<22>,  Next: C API<26>,  Prev: macOS<16>,  Up: Python 3 12 0 alpha 4

1.24.30.12 Tools/Demos
......................

   - bpo-45256(1): Fix a bug that caused an *note AttributeError: 5f0.
     to be raised in ‘python-gdb.py’ when ‘py-locals’ is used without a
     frame.

   - gh-100342(2): Add missing ‘NULL’ check for possible allocation
     failure in ‘*args’ parsing in Argument Clinic.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45256

   (2) https://github.com/python/cpython/issues/100342


File: python.info,  Node: C API<26>,  Prev: Tools/Demos<22>,  Up: Python 3 12 0 alpha 4

1.24.30.13 C API
................

   - gh-99947(1): Raising SystemError on import will now have its cause
     be set to the original unexpected exception.

   - gh-99240(2): In argument parsing, after deallocating newly
     allocated memory, reset its pointer to NULL.

   - gh-98724(3): The *note Py_CLEAR: 799, *note Py_SETREF: 79a. and
     *note Py_XSETREF: 79b. macros now only evaluate their arguments
     once.  If an argument has side effects, these side effects are no
     longer duplicated.  Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99947

   (2) https://github.com/python/cpython/issues/99240

   (3) https://github.com/python/cpython/issues/98724


File: python.info,  Node: Python 3 12 0 alpha 3,  Next: Python 3 12 0 alpha 2,  Prev: Python 3 12 0 alpha 4,  Up: Changelog

1.24.31 Python 3.12.0 alpha 3
-----------------------------

'Release date: 2022-12-06'

* Menu:

* Security: Security<25>.
* Core and Builtins: Core and Builtins<69>.
* Library: Library<74>.
* Core and Builtins: Core and Builtins<70>.
* Library: Library<75>.
* Documentation: Documentation<25>.
* Tests: Tests<25>.
* Build: Build<29>.
* Windows: Windows<26>.
* macOS: macOS<17>.
* Tools/Demos: Tools/Demos<23>.
* C API: C API<27>.


File: python.info,  Node: Security<25>,  Next: Core and Builtins<69>,  Up: Python 3 12 0 alpha 3

1.24.31.1 Security
..................

   - gh-100001(1): ‘python -m http.server’ no longer allows terminal
     control characters sent within a garbage request to be printed to
     the stderr server log.

     This is done by changing the *note http.server: 76.
     ‘BaseHTTPRequestHandler’ ‘.log_message’ method to replace control
     characters with a ‘\xHH’ hex escape before printing.

   - gh-87604(2): Avoid publishing list of active per-interpreter audit
     hooks via the *note gc: 64. module

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100001

   (2) https://github.com/python/cpython/issues/87604


File: python.info,  Node: Core and Builtins<69>,  Next: Library<74>,  Prev: Security<25>,  Up: Python 3 12 0 alpha 3

1.24.31.2 Core and Builtins
...........................

   - gh-99891(1): Fix a bug in the tokenizer that could cause infinite
     recursion when showing syntax warnings that happen in the first
     line of the source.  Patch by Pablo Galindo

   - gh-91054(2): Add *note PyCode_AddWatcher(): 788. and *note
     PyCode_ClearWatcher(): 789. APIs to register callbacks to receive
     notification on creation and destruction of code objects.

   - gh-99729(3): Fix an issue that could cause frames to be visible to
     Python code as they are being torn down, possibly leading to memory
     corruption or hard crashes of the interpreter.

   - gh-99708(4): Fix bug where compiler crashes on an if expression
     with an empty body block.

   - gh-99578(5): Fix a reference bug in ‘_imp.create_builtin()’ after
     the creation of the first sub-interpreter for modules ‘builtins’
     and ‘sys’.  Patch by Victor Stinner.

   - gh-99581(6): Fixed a bug that was causing a buffer overflow if the
     tokenizer copies a line missing the newline character from a file
     that is as long as the available tokenizer buffer.  Patch by Pablo
     galindo

   - gh-99553(7): Fix bug where an *note ExceptionGroup: 4d3. subclass
     can wrap a *note BaseException: 7d8.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99891

   (2) https://github.com/python/cpython/issues/91054

   (3) https://github.com/python/cpython/issues/99729

   (4) https://github.com/python/cpython/issues/99708

   (5) https://github.com/python/cpython/issues/99578

   (6) https://github.com/python/cpython/issues/99581

   (7) https://github.com/python/cpython/issues/99553


File: python.info,  Node: Library<74>,  Next: Core and Builtins<70>,  Prev: Core and Builtins<69>,  Up: Python 3 12 0 alpha 3

1.24.31.3 Library
.................

   - gh-99547(1): Add a function to os.path to check if a path is a
     junction: isjunction.  Add similar functionality to pathlib.Path as
     is_junction.

   - gh-99370(2): Fix zip path for venv created from a non-installed
     python on POSIX platforms.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99547

   (2) https://github.com/python/cpython/issues/99370


File: python.info,  Node: Core and Builtins<70>,  Next: Library<75>,  Prev: Library<74>,  Up: Python 3 12 0 alpha 3

1.24.31.4 Core and Builtins
...........................

   - gh-99377(1): Add audit events for thread creation and clear
     operations.

   - gh-98686(2): Remove the ‘BINARY_OP_GENERIC’ and
     ‘COMPARE_OP_GENERIC’ «specializations».

   - gh-99298(3): Remove the remaining error paths for attribute
     specializations, and refuse to specialize attribute accesses on
     types that haven’t had *note PyType_Ready(): 981. called on them
     yet.

   - gh-99127(4): Allow some features of *note syslog: e2. to the main
     interpreter only.  Patch by Donghee Na.

   - gh-91053(5): Optimizing interpreters and JIT compilers may need to
     invalidate internal metadata when functions are modified.  This
     change adds the ability to provide a callback that will be invoked
     each time a function is created, modified, or destroyed.

   - gh-90994(6): Improve error messages when there’s a syntax error
     with call arguments.  The following three cases are covered: - No
     value is assigned to a named argument, eg ‘foo(a=)’.  - A value is
     assigned to a star argument, eg ‘foo(*args=[0])’.  - A value is
     assigned to a double-star keyword argument, eg ‘foo(**kwarg={'a':
     0})’.

   - bpo-45026(7): Optimize the *note range: b3f. object iterator.  It
     is now smaller, faster iteration of ranges containing large
     numbers.  Smaller pickles, faster unpickling.

   - bpo-31718(8): Raise *note ValueError: 2ec. instead of *note
     SystemError: 796. when methods of uninitialized *note
     io.IncrementalNewlineDecoder: 1a26. objects are called.  Patch by
     Oren Milman.

   - bpo-38031(9): Fix a possible assertion failure in *note io.FileIO:
     1517. when the opener returns an invalid file descriptor.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99377

   (2) https://github.com/python/cpython/issues/98686

   (3) https://github.com/python/cpython/issues/99298

   (4) https://github.com/python/cpython/issues/99127

   (5) https://github.com/python/cpython/issues/91053

   (6) https://github.com/python/cpython/issues/90994

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45026

   (8) https://bugs.python.org/issue?@action=redirect&bpo=31718

   (9) https://bugs.python.org/issue?@action=redirect&bpo=38031


File: python.info,  Node: Library<75>,  Next: Documentation<25>,  Prev: Core and Builtins<70>,  Up: Python 3 12 0 alpha 3

1.24.31.5 Library
.................

   - gh-100001(1): Also escape s in the http.server
     BaseHTTPRequestHandler.log_message so that it is technically
     possible to parse the line and reconstruct what the original data
     was.  Without this a xHH is ambiguous as to if it is a hex
     replacement we put in or the characters r»x» came through in the
     original request line.

   - gh-99957(2): Add ‘frozen_default’ parameter to *note
     typing.dataclass_transform(): 6fc.

   - gh-79033(3): Fix *note asyncio.Server.wait_closed(): 1a27. to
     actually do what the docs promise – wait for all existing
     connections to complete, after closing the server.

   - gh-51524(4): Fix bug when calling trace.CoverageResults with valid
     infile.

   - gh-99645(5): Fix a bug in handling class cleanups in *note
     unittest.TestCase: 2b3.  Now ‘addClassCleanup()’ uses separate
     lists for different ‘TestCase’ subclasses, and ‘doClassCleanups()’
     only cleans up the particular class.

   - gh-99508(6): Fix ‘TypeError’ in
     ‘Lib/importlib/_bootstrap_external.py’ while calling
     ‘_imp.source_hash()’.

   - gh-66285(7): Fix *note asyncio: b. to not share event loop and
     signal wakeupfd in forked processes.  Patch by Kumar Aditya.

   - gh-97001(8): Release the GIL when calling termios APIs to avoid
     blocking threads.

   - gh-92647(9): Use final status of an enum to determine lookup or
     creation branch of functional API.

   - gh-99388(10): Add 'loop_factory' parameter to *note asyncio.run():
     2f3. to allow specifying a custom event loop factory.  Patch by
     Kumar Aditya.

   - gh-99341(11): Fix *note ast.increment_lineno(): 1af5. to also cover
     *note ast.TypeIgnore: 1af6. when changing line numbers.

   - gh-99382(12): Check the number of arguments in substitution in user
     generics containing a *note TypeVarTuple: 489. and one or more
     *note TypeVar: 487.

   - gh-99379(13): Fix substitution of *note ParamSpec: 488. followed by
     *note TypeVarTuple: 489. in generic aliases.

   - gh-99344(14): Fix substitution of *note TypeVarTuple: 489. and
     *note ParamSpec: 488. together in user generics.

   - gh-99284(15): Remove ‘_use_broken_old_ctypes_structure_semantics_’
     old untested and undocumented hack from *note ctypes: 2e.

   - gh-99201(16): Fix *note IndexError: 173c. when initializing the
     config variables on Windows if ‘HAVE_DYNAMIC_LOADING’ is not set.

   - gh-99240(17): Fix double-free bug in Argument Clinic
     ‘str_converter’ by extracting memory clean up to a new
     ‘post_parsing’ section.

   - gh-64490(18): Fix refcount error when arguments are packed to tuple
     in Argument Clinic.

   - gh-99029(19): *note pathlib.PurePath.relative_to(): 2fd. now treats
     naked Windows drive paths as relative.  This brings its behaviour
     in line with other parts of pathlib.

   - gh-98253(20): The implementation of the typing module is now more
     resilient to reference leaks in binary extension modules.

     Previously, a reference leak in a typed C API-based extension
     module could leak internals of the typing module, which could in
     turn introduce leaks in essentially any other package with typed
     function signatures.  Although the typing package is not the
     original source of the problem, such non-local dependences
     exacerbate debugging of large-scale projects, and the
     implementation was therefore changed to reduce harm by providing
     better isolation.

   - gh-98458(21): Fix infinite loop in unittest when a self-referencing
     chained exception is raised

   - gh-93453(22): *note asyncio.get_event_loop(): 2f2. and many other
     *note asyncio: b. functions like *note asyncio.ensure_future():
     e73, *note asyncio.shield(): c67. or *note asyncio.gather(): 814,
     and also the ‘get_event_loop()’ method of
     ‘asyncio.BaseDefaultEventLoopPolicy’ now raise a *note
     RuntimeError: 244. if called when there is no running event loop
     and the current event loop was not set.  Previously they implicitly
     created and set a new current event loop.  *note
     DeprecationWarning: 1a3. is no longer emitted if there is no
     running event loop but the current event loop was set.

   - gh-97966(23): On ‘uname_result’, restored expectation that
     ‘_fields’ and ‘_asdict’ would include all six properties including
     ‘processor’.

   - gh-98248(24): Provide informative error messages in *note
     struct.pack(): 147e. when its integral arguments are not in range.

   - gh-98108(25): ‘zipfile.Path’ is now pickleable if its
     initialization parameters were pickleable (e.g.  for file system
     paths).

   - gh-98098(26): Created packages from zipfile and test_zipfile
     modules, separating ‘zipfile.Path’ functionality.

   - gh-82836(27): Fix *note is_private: 19ab. properties in the *note
     ipaddress: 84. module.  Previously non-private networks (0.0.0.0/0)
     would return ‘True’ from this method; now they correctly return
     ‘False’.

   - gh-96828(28): Add an *note OP_ENABLE_KTLS: 1af7. option for
     enabling the use of the kernel TLS (kTLS). Patch by Illia Volochii.

   - gh-88863(29): To avoid apparent memory leaks when *note
     asyncio.open_connection(): d10. raises, break reference cycles
     generated by local exception and future instances (which has
     exception instance as its member var).  Patch by Dong Uk, Kang.

   - gh-91078(30): ‘TarFile.next()’ now returns ‘None’ when called on an
     empty tarfile.

   - bpo-47220(31): Document the optional 'callback' parameter of
     ‘WeakMethod’.  Patch by Géry Ogam.

   - bpo-44817(32): Ignore WinError 53 (ERROR_BAD_NETPATH), 65
     (ERROR_NETWORK_ACCESS_DENIED) and 161 (ERROR_BAD_PATHNAME) when
     using ntpath.realpath().

   - bpo-41260(33): Rename the 'fmt' parameter of the pure Python
     implementation of *note datetime.date.strftime(): e91. to 'format'.

   - bpo-15999(34): All built-in functions now accept arguments of any
     type instead of just ‘bool’ and ‘int’ for boolean parameters.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/100001

   (2) https://github.com/python/cpython/issues/99957

   (3) https://github.com/python/cpython/issues/79033

   (4) https://github.com/python/cpython/issues/51524

   (5) https://github.com/python/cpython/issues/99645

   (6) https://github.com/python/cpython/issues/99508

   (7) https://github.com/python/cpython/issues/66285

   (8) https://github.com/python/cpython/issues/97001

   (9) https://github.com/python/cpython/issues/92647

   (10) https://github.com/python/cpython/issues/99388

   (11) https://github.com/python/cpython/issues/99341

   (12) https://github.com/python/cpython/issues/99382

   (13) https://github.com/python/cpython/issues/99379

   (14) https://github.com/python/cpython/issues/99344

   (15) https://github.com/python/cpython/issues/99284

   (16) https://github.com/python/cpython/issues/99201

   (17) https://github.com/python/cpython/issues/99240

   (18) https://github.com/python/cpython/issues/64490

   (19) https://github.com/python/cpython/issues/99029

   (20) https://github.com/python/cpython/issues/98253

   (21) https://github.com/python/cpython/issues/98458

   (22) https://github.com/python/cpython/issues/93453

   (23) https://github.com/python/cpython/issues/97966

   (24) https://github.com/python/cpython/issues/98248

   (25) https://github.com/python/cpython/issues/98108

   (26) https://github.com/python/cpython/issues/98098

   (27) https://github.com/python/cpython/issues/82836

   (28) https://github.com/python/cpython/issues/96828

   (29) https://github.com/python/cpython/issues/88863

   (30) https://github.com/python/cpython/issues/91078

   (31) https://bugs.python.org/issue?@action=redirect&bpo=47220

   (32) https://bugs.python.org/issue?@action=redirect&bpo=44817

   (33) https://bugs.python.org/issue?@action=redirect&bpo=41260

   (34) https://bugs.python.org/issue?@action=redirect&bpo=15999


File: python.info,  Node: Documentation<25>,  Next: Tests<25>,  Prev: Library<75>,  Up: Python 3 12 0 alpha 3

1.24.31.6 Documentation
.......................

   - gh-99931(1): Use sphinxext-opengraph(2) to generate OpenGraph
     metadata(3).

   - gh-89682(4): Reworded docstring of the default ‘__contains__’ to
     clarify that it returns a *note bool: 3c3.

   - gh-88330(5): Improved the description of what a resource is in
     importlib.resources docs.

   - gh-92892(6): Document that calling variadic functions with ctypes
     requires special care on macOS/arm64 (and possibly other
     platforms).

   - bpo-41825(7): Restructured the documentation for the *note
     os.wait*: f9a. family of functions, and improved the docs for *note
     os.waitid(): f9b. with more explanation of the possible argument
     constants.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99931

   (2) https://sphinxext-opengraph.readthedocs.io/

   (3) https://ogp.me/

   (4) https://github.com/python/cpython/issues/89682

   (5) https://github.com/python/cpython/issues/88330

   (6) https://github.com/python/cpython/issues/92892

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41825


File: python.info,  Node: Tests<25>,  Next: Build<29>,  Prev: Documentation<25>,  Up: Python 3 12 0 alpha 3

1.24.31.7 Tests
...............

   - gh-99892(1): Skip test_normalization() of test_unicodedata if it
     fails to download NormalizationTest.txt file from pythontest.net.
     Patch by Victor Stinner.

   - gh-99934(2): Correct test_marsh on (32 bit) x86: test_deterministic
     sets was failing.

   - gh-99741(3): We’ve implemented multi-phase init (PEP 489/630/687)
     for the internal (for testing) _xxsubinterpreters module.

   - gh-99659(4): Optional big memory tests in ‘test_sqlite3’ now catch
     the correct ‘sqlite.DataError’ exception type in case of too large
     strings and/or blobs passed.

   - gh-99593(5): Cover the Unicode C API with tests.

   - gh-96002(6): Add functional test for Argument Clinic.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99892

   (2) https://github.com/python/cpython/issues/99934

   (3) https://github.com/python/cpython/issues/99741

   (4) https://github.com/python/cpython/issues/99659

   (5) https://github.com/python/cpython/issues/99593

   (6) https://github.com/python/cpython/issues/96002


File: python.info,  Node: Build<29>,  Next: Windows<26>,  Prev: Tests<25>,  Up: Python 3 12 0 alpha 3

1.24.31.8 Build
...............

   - gh-99086(1): Fix ‘-Wimplicit-int’, ‘-Wstrict-prototypes’, and
     ‘-Wimplicit-function-declaration’ compiler warnings in ‘configure’
     checks.

   - gh-99337(2): Fix a compilation issue with GCC 12 on macOS.

   - gh-99289(3): Add a ‘COMPILEALL_OPTS’ variable in Makefile to
     override *note compileall: 21. options (default: ‘-j0’) in ‘make
     install’.  Also merged the ‘compileall’ commands into a single
     command building .pyc files for the all optimization levels (0, 1,
     2) at once.  Patch by Victor Stinner.

   - gh-98872(4): Fix a possible fd leak in ‘Programs/_freeze_module.c’
     introduced in Python 3.11.

   - gh-88226(5): Always define ‘TARGET_*’ labels in ‘Python/ceval.c’,
     even if ‘USE_COMPUTED_GOTOS’ is disabled.  This allows breakpoints
     to be set at those labels in (for instance) ‘gdb’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99086

   (2) https://github.com/python/cpython/issues/99337

   (3) https://github.com/python/cpython/issues/99289

   (4) https://github.com/python/cpython/issues/98872

   (5) https://github.com/python/cpython/issues/88226


File: python.info,  Node: Windows<26>,  Next: macOS<17>,  Prev: Build<29>,  Up: Python 3 12 0 alpha 3

1.24.31.9 Windows
.................

   - gh-99345(1): Use faster initialization functions to detect install
     location for Windows Store package

   - gh-98629(2): Fix initialization of *note sys.version: 49d. and
     ‘sys._git’ on Windows

   - gh-99442(3): Fix handling in *note Python install manager: 7db.
     when ‘argv[0]’ does not include a file extension.

   - bpo-40882(4): Fix a memory leak in *note
     multiprocessing.shared_memory.SharedMemory: 19c0. on Windows.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99345

   (2) https://github.com/python/cpython/issues/98629

   (3) https://github.com/python/cpython/issues/99442

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40882


File: python.info,  Node: macOS<17>,  Next: Tools/Demos<23>,  Prev: Windows<26>,  Up: Python 3 12 0 alpha 3

1.24.31.10 macOS
................

   - gh-87235(1): On macOS ‘python3 /dev/fd/9 9</path/to/script.py’
     failed for any script longer than a couple of bytes.

   - gh-98940(2): Fix ‘Mac/Extras.install.py’ file filter bug.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/87235

   (2) https://github.com/python/cpython/issues/98940


File: python.info,  Node: Tools/Demos<23>,  Next: C API<27>,  Prev: macOS<17>,  Up: Python 3 12 0 alpha 3

1.24.31.11 Tools/Demos
......................

   - gh-64490(1): Argument Clinic varargs bugfixes

        * Fix out-of-bounds error in
          ‘_PyArg_UnpackKeywordsWithVararg()’.

        * Fix incorrect check which allowed more than one varargs in
          clinic.py.

        * Fix miscalculation of ‘noptargs’ in generated code.

        * Do not generate ‘noptargs’ when there is a vararg argument and
          no optional argument.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/64490


File: python.info,  Node: C API<27>,  Prev: Tools/Demos<23>,  Up: Python 3 12 0 alpha 3

1.24.31.12 C API
................

   - gh-98680(1): ‘PyBUF_*’ constants were marked as part of Limited API
     of Python 3.11+.  These were available in 3.11.0 with *note
     Py_LIMITED_API: 660. defined for 3.11, and are necessary to use the
     buffer API.

   - gh-99612(2): Fix *note PyUnicode_DecodeUTF8Stateful(): 1aff. for
     ASCII-only data: ‘*consumed’ was not set.

   - gh-47146(3): The ‘structmember.h’ header is deprecated.  Its
     non-deprecated contents are now available just by including
     ‘Python.h’, with a ‘Py_’ prefix added if it was missing.
     (Deprecated contents are *note T_OBJECT: 7b1, *note T_NONE: 7b3,
     and no-op flags.)  Patch by Petr Viktorin, based on earlier work by
     Alexander Belopolsky and Matthias Braun.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98680

   (2) https://github.com/python/cpython/issues/99612

   (3) https://github.com/python/cpython/issues/47146


File: python.info,  Node: Python 3 12 0 alpha 2,  Next: Python 3 12 0 alpha 1,  Prev: Python 3 12 0 alpha 3,  Up: Changelog

1.24.32 Python 3.12.0 alpha 2
-----------------------------

'Release date: 2022-11-14'

* Menu:

* Security: Security<26>.
* Core and Builtins: Core and Builtins<71>.
* Build: Build<30>.
* Core and Builtins: Core and Builtins<72>.
* Library: Library<76>.
* Documentation: Documentation<26>.
* Tests: Tests<26>.
* Build: Build<31>.
* Windows: Windows<27>.
* macOS: macOS<18>.
* C API: C API<28>.


File: python.info,  Node: Security<26>,  Next: Core and Builtins<71>,  Up: Python 3 12 0 alpha 2

1.24.32.1 Security
..................

   - gh-98433(1): The IDNA codec decoder used on DNS hostnames by *note
     socket: d1. or *note asyncio: b. related name resolution functions
     no longer involves a quadratic algorithm.  This prevents a
     potential CPU denial of service if an out-of-spec excessive length
     hostname involving bidirectional characters were decoded.  Some
     protocols such as *note urllib: 10e. http ‘3XX’ redirects
     potentially allow for an attacker to supply such a name.

     Individual labels within an IDNA encoded DNS name will now raise an
     error early during IDNA decoding if they are longer than 1024
     unicode characters given that each decoded DNS label must be 63 or
     fewer characters and the entire decoded DNS name is limited to 255.
     Only an application presenting a hostname or label consisting
     primarily of RFC 3454(2) section 3.1 «Nothing» characters to be
     removed would run into of this new limit.  See also RFC 5894(3)
     section 6 and RFC 3491(4).

   - gh-98739(5): Update bundled libexpat to 2.5.0

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98433

   (2) https://datatracker.ietf.org/doc/html/rfc3454.html

   (3) https://datatracker.ietf.org/doc/html/rfc5894.html

   (4) https://datatracker.ietf.org/doc/html/rfc3491.html

   (5) https://github.com/python/cpython/issues/98739


File: python.info,  Node: Core and Builtins<71>,  Next: Build<30>,  Prev: Security<26>,  Up: Python 3 12 0 alpha 2

1.24.32.2 Core and Builtins
...........................

   - gh-81057(1): The docs clearly say that *note PyImport_Inittab:
     1b03, *note PyImport_AppendInittab(): 1b04, and *note
     PyImport_ExtendInittab(): 1b05. should not be used after *note
     Py_Initialize(): 460. has been called.  We now enforce this for the
     two functions.  Additionally, the runtime now uses an internal copy
     of *note PyImport_Inittab: 1b03, to guard against modification.

   - gh-99298(2): Fix an issue that could potentially cause incorrect
     error handling for some bytecode instructions.

   - gh-99254(3): The compiler now removes all unused constants from
     code objects (except the first one, which may be a docstring).

   - gh-99205(4): Fix an issue that prevented *note PyThreadState: 991.
     and *note PyInterpreterState: abc. memory from being freed
     properly.

   - gh-81057(5): The 18 global C variables holding the state of the
     allocators have been moved to ‘_PyRuntimeState’.  This is a
     strictly internal change with no change in behavior.

   - gh-99181(6): Fix failure in *note except*: 1ac. with unhashable
     exceptions.

   - gh-99204(7): Fix calculation of ‘sys._base_executable’ when inside
     a POSIX virtual environment using copies of the python binary when
     the base installation does not provide the executable name used by
     the venv.  Calculation will fall back to alternative names
     («python<MAJOR>», «python<MAJOR>.<MINOR>»).

   - gh-96055(8): Update *note faulthandler: 5c. to emit an error
     message with the proper unexpected signal number.  Patch by Donghee
     Na.

   - gh-99153(9): Fix location of *note SyntaxError: 18e. for a *note
     try: 8f9. block with both *note except: 1ab. and *note except*:
     1ac.

   - gh-98686(10): Merge the adaptive opcode logic into each
     instruction’s unquickened variant, and merge the logic in
     ‘EXTENDED_ARG_QUICK’ into *note EXTENDED_ARG: 1b06.  With these
     changes, the quickening that happens at code object creation is now
     only responsible for initializing warmup counters and inserting
     superinstructions.

   - gh-99103(11): Fix the error reporting positions of specialized
     traceback anchors when the source line contains Unicode characters.

   - gh-99139(12): Improve the error suggestion for *note NameError:
     452. exceptions for instances.  Now if a *note NameError: 452. is
     raised in a method and the instance has an attribute that’s exactly
     equal to the name in the exception, the suggestion will include
     ‘self.<NAME>’ instead of the closest match in the method scope.
     Patch by Pablo Galindo

   - gh-98401(13): Octal escapes with value larger than ‘0o377’ (ex:
     ‘"\477"’), deprecated in Python 3.11, now produce a *note
     SyntaxWarning: 1ae, instead of *note DeprecationWarning: 1a3.  In a
     future Python version they will be eventually a *note SyntaxError:
     18e.  Patch by Victor Stinner.

   - gh-98401(14): A backslash-character pair that is not a valid escape
     sequence now generates a *note SyntaxWarning: 1ae, instead of *note
     DeprecationWarning: 1a3.  For example, ‘re.compile("\d+\.\d+")’ now
     emits a *note SyntaxWarning: 1ae. (‘"\d"’ is an invalid escape
     sequence), use raw strings for regular expression:
     ‘re.compile(r"\d+\.\d+")’.  In a future Python version, *note
     SyntaxError: 18e. will eventually be raised, instead of *note
     SyntaxWarning: 1ae.  Patch by Victor Stinner.

   - gh-96793(15): Handle StopIteration and StopAsyncIteration raised in
     generator or coroutines in the bytecode, rather than in wrapping C
     code.

   - gh-98931(16): Improve the *note SyntaxError: 18e. error message
     when the user types ‘import x from y’ instead of ‘from y import x’.
     Patch by Pablo Galindo

   - gh-98852(17): Fix subscription of type aliases containing bare
     generic types or types like *note TypeVar: 487.: for example
     ‘tuple[A, T][int]’ and ‘tuple[TypeVar, T][int]’, where ‘A’ is a
     generic type, and ‘T’ is a type variable.

   - gh-98925(18): Lower the recursion depth for marshal on WASI to
     support (in-development) wasmtime 2.0.

   - gh-98783(19): Fix multiple crashes in debug mode when ‘str’
     subclasses are used instead of ‘str’ itself.

   - gh-98811(20): Use complete source locations to simplify detection
     of ‘__future__’ imports which are not at the beginning of the file.
     Also corrects the offset in the exception raised in one case, which
     was off by one and impeded highlighting.

   - gh-96793(21): Add specialization of *note FOR_ITER: 1aaa. for
     generators.  Saves multiple layers of dispatch and checking to get
     from the *note FOR_ITER: 1aaa. instruction in the caller to the
     *note RESUME: 5bb. in the generator.

   - gh-98762(22): Fix source locations of *note match: a10.
     sub-patterns.

   - gh-98586(23): Added the methods *note PyObject_Vectorcall(): 77f.
     and *note PyObject_VectorcallMethod(): 780. to the *note Limited
     API: 776. along with the auxiliary macro constant *note
     PY_VECTORCALL_ARGUMENTS_OFFSET: 781.

     The availability of these functions enables more efficient PEP
     590(24) vector calls from binary extension modules that avoid
     argument boxing/unboxing overheads.

   - gh-99257(25): Fix an issue where member descriptors (such as those
     for *note __slots__: 16f2.) could behave incorrectly or crash
     instead of raising a *note TypeError: 198. when accessed via an
     instance of an invalid type.

   - gh-93143(26): Rather than changing ‘co_code’, the interpreter will
     now display a *note RuntimeWarning: 4d8. and assign *note None:
     886. to any fast locals that are left unbound after jumps or *note
     del: 1b07. statements executed while tracing.

   - gh-96421(27): When calling into Python code from C code, through
     *note PyEval_EvalFrameEx(): 1230. or a related C-API function, a
     shim frame in inserted into the call stack.  This occurs in the
     ‘_PyEval_EvalFrameDefault()’ function.  The extra frame should be
     invisible to all Python and most C extensions, but out-of-process
     profilers and debuggers need to be aware of it.  These shim frames
     can be detected by checking ‘frame->owner ==
     FRAME_OWNED_BY_CSTACK’.

     Extensions implementing their own interpreters using PEP 523 need
     to be aware of this shim frame and the changes to the semantics of
     *note RETURN_VALUE: 1b08, *note YIELD_VALUE: 5ba, and *note
     RETURN_GENERATOR: 90c, which now clear the frame.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/81057

   (2) https://github.com/python/cpython/issues/99298

   (3) https://github.com/python/cpython/issues/99254

   (4) https://github.com/python/cpython/issues/99205

   (5) https://github.com/python/cpython/issues/81057

   (6) https://github.com/python/cpython/issues/99181

   (7) https://github.com/python/cpython/issues/99204

   (8) https://github.com/python/cpython/issues/96055

   (9) https://github.com/python/cpython/issues/99153

   (10) https://github.com/python/cpython/issues/98686

   (11) https://github.com/python/cpython/issues/99103

   (12) https://github.com/python/cpython/issues/99139

   (13) https://github.com/python/cpython/issues/98401

   (14) https://github.com/python/cpython/issues/98401

   (15) https://github.com/python/cpython/issues/96793

   (16) https://github.com/python/cpython/issues/98931

   (17) https://github.com/python/cpython/issues/98852

   (18) https://github.com/python/cpython/issues/98925

   (19) https://github.com/python/cpython/issues/98783

   (20) https://github.com/python/cpython/issues/98811

   (21) https://github.com/python/cpython/issues/96793

   (22) https://github.com/python/cpython/issues/98762

   (23) https://github.com/python/cpython/issues/98586

   (24) https://peps.python.org/pep-0590/

   (25) https://github.com/python/cpython/issues/99257

   (26) https://github.com/python/cpython/issues/93143

   (27) https://github.com/python/cpython/issues/96421


File: python.info,  Node: Build<30>,  Next: Core and Builtins<72>,  Prev: Core and Builtins<71>,  Up: Python 3 12 0 alpha 2

1.24.32.3 Build
...............

   - gh-98415(1): Fix detection of MAC addresses for *note uuid: 116. on
     certain OSs.  Patch by Chaim Sanders

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98415


File: python.info,  Node: Core and Builtins<72>,  Next: Library<76>,  Prev: Build<30>,  Up: Python 3 12 0 alpha 2

1.24.32.4 Core and Builtins
...........................

   - gh-98686(1): Quicken all code objects, and specialize adaptive
     bytecode instructions more aggressively.

   - gh-92119(2): Print exception class name instead of its string
     representation when raising errors from *note ctypes: 2e. calls.

   - gh-91058(3): *note ImportError: 65b. raised from failed ‘from
     <module> import <name>’ now include suggestions for the value of
     ‘<name>’ based on the available names in ‘<module>’.  Patch by
     Pablo Galindo

   - gh-96793(4): The *note FOR_ITER: 1aaa. now leaves the iterator on
     the stack on termination of the loop.  This is to assist
     specialization of loops for generators.

   - gh-90716(5): Add _pylong.py module.  It includes asymptotically
     faster algorithms that can be used for operations on integers with
     many digits.  It is used by longobject.c to speed up some
     operations.

   - gh-95389(6): Expose *note ETH_P_ALL: 1b0b. and some of the *note
     ETHERTYPE_* constants: 1b0c. in *note socket: d1.  Patch by Noam
     Cohen.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98686

   (2) https://github.com/python/cpython/issues/92119

   (3) https://github.com/python/cpython/issues/91058

   (4) https://github.com/python/cpython/issues/96793

   (5) https://github.com/python/cpython/issues/90716

   (6) https://github.com/python/cpython/issues/95389


File: python.info,  Node: Library<76>,  Next: Documentation<26>,  Prev: Core and Builtins<72>,  Up: Python 3 12 0 alpha 2

1.24.32.5 Library
.................

   - gh-93696(1): Allow *note pdb: aa. to locate source for frozen
     modules in the standard library.

   - gh-99418(2): Fix bug in *note urllib.parse.urlparse(): 362. that
     causes URL schemes that begin with a digit, a plus sign, or a minus
     sign to be parsed incorrectly.

   - gh-94597(3): Deprecate ‘asyncio.AbstractChildWatcher’ to be removed
     in Python 3.14.  Patch by Kumar Aditya.

   - gh-99305(4): Improve performance of *note secrets.token_hex():
     1b0e.

   - gh-74044(5): Fixed bug where *note inspect.signature(): 22f.
     reported incorrect arguments for decorated methods.

   - gh-99275(6): Fix ‘SystemError’ in *note ctypes: 2e. when exception
     was not set during ‘__initsubclass__’.

   - gh-99277(7): Remove older version of
     ‘_SSLProtocolTransport.get_write_buffer_limits’ in
     ‘asyncio.sslproto’

   - gh-99248(8): fix negative numbers failing in verify()

   - gh-99155(9): Fix *note statistics.NormalDist: c2f. pickle with ‘0’
     and ‘1’ protocols.

   - gh-93464(10): ‘enum.auto()’ is now correctly activated when
     combined with other assignment values.  E.g.  ‘ONE = auto(), 'some
     text'’ will now evaluate as ‘(1, 'some text')’.

   - gh-99134(11): Update the bundled copy of pip to version 22.3.1.

   - gh-92584(12): Remove the ‘distutils’ package.  It was deprecated in
     Python 3.10 by PEP 632(13) «Deprecate distutils module».  For
     projects still using ‘distutils’ and cannot be updated to something
     else, the ‘setuptools’ project can be installed: it still provides
     ‘distutils’.  Patch by Victor Stinner.

   - gh-98999(14): Now ‘_pyio’ is consistent with ‘_io’ in raising
     ‘ValueError’ when executing methods over closed buffers.

   - gh-83004(15): Clean up refleak on failed module initialisation in
     ‘_zoneinfo’

   - gh-83004(16): Clean up refleaks on failed module initialisation in
     ‘_pickle’

   - gh-83004(17): Clean up refleak on failed module initialisation in
     ‘_io’.

   - gh-98897(18): Fix memory leak in *note math.dist(): bf7. when both
     points don’t have the same dimension.  Patch by Kumar Aditya.

   - gh-98878(19): Use the frame bound builtins when offering a name
     suggestion in *note traceback: 104. to prevent crashing when
     ‘__builtins__’ is not a dict.

   - gh-98139(20): In ‘importlib._bootstrap’, enhance namespace package
     repr to ‘<module 'x' (namespace) from ['path']>’.

   - gh-90352(21): Fix ‘_SelectorDatagramTransport’ to inherit from
     *note DatagramTransport: 1b0f. in *note asyncio: b.  Patch by Kumar
     Aditya.

   - gh-98793(22): Fix argument typechecks in ‘_overlapped.WSAConnect()’
     and ‘_overlapped.Overlapped.WSASendTo()’ functions.

   - gh-98744(23): Prevent crashing in *note traceback: 104. when
     retrieving the byte-offset for some source files that contain
     certain unicode characters.

   - gh-98740(24): Fix internal error in the *note re: be. module which
     in very rare circumstances prevented compilation of a regular
     expression containing a *note conditional expression: 1b10. without
     the «else» branch.

   - gh-98703(25): Fix *note asyncio.StreamWriter.drain(): 1b11. to call
     ‘protocol.connection_lost’ callback only once on Windows.

   - gh-98624(26): Add a mutex to unittest.mock.NonCallableMock to
     protect concurrent access to mock attributes.

   - gh-98658(27): The *note array.array: 4bf. class now supports
     subscripting, making it a *note generic type: 1a1.

   - gh-98284(28): Improved *note TypeError: 198. message for undefined
     abstract methods of a *note abc.ABC: 111c. instance.  The names of
     the missing methods are surrounded by single-quotes to highlight
     them.

   - gh-96151(29): Allow ‘BUILTINS’ to be a valid field name for frozen
     dataclasses.

   - gh-98086(30): Make sure ‘patch.dict()’ can be applied on async
     functions.

   - gh-72719(31): Remove modules ‘asyncore’ and ‘asynchat’, which were
     deprecated by PEP 594(32).

   - gh-96192(33): Fix handling of ‘bytes’ *note path-like objects: 5a1.
     in ‘os.ismount()’.

   - gh-94172(34): *note ftplib: 62.: Remove the ‘FTP_TLS.ssl_version’
     class attribute: use the 'context' parameter instead.  Patch by
     Victor Stinner

   - gh-94172(35): Remove the 'keyfile' and 'certfile' parameters from
     the *note ftplib: 62, *note imaplib: 78, *note poplib: b1. and
     *note smtplib: cf. modules, and the 'key_file', 'cert_file' and
     'check_hostname' parameters from the *note http.client: 73. module,
     all deprecated since Python 3.6.  Use the 'context' parameter
     ('ssl_context' in *note imaplib: 78.) instead.  Patch by Victor
     Stinner.

   - gh-83638(36): Add the *note autocommit: 6de. attribute to *note
     sqlite3.Connection: 54e. and the 'autocommit' parameter to *note
     sqlite3.connect(): 5a6. to control PEP 249(37)-compliant *note
     transaction handling: 6df.  Patch by Erlend E. Aasland.

   - gh-92452(38): Fixed a race condition that could cause *note
     sysconfig.get_config_var(): 174. to incorrectly return *note None:
     886. in multi-threaded programs.

   - gh-91803(39): Fix an error when using a method of objects mocked
     with *note unittest.mock.create_autospec(): 191c. after it was
     sealed with *note unittest.mock.seal(): d9c. function.

   - bpo-38523(40): *note shutil.copytree(): c20. now applies the
     'ignore_dangling_symlinks' argument recursively.

   - bpo-40358(41): Add walk_up argument in *note
     pathlib.PurePath.relative_to(): 2fd.

   - bpo-36267(42): Fix IndexError in *note argparse.ArgumentParser:
     1bd. when a ‘store_true’ action is given an explicit argument.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/93696

   (2) https://github.com/python/cpython/issues/99418

   (3) https://github.com/python/cpython/issues/94597

   (4) https://github.com/python/cpython/issues/99305

   (5) https://github.com/python/cpython/issues/74044

   (6) https://github.com/python/cpython/issues/99275

   (7) https://github.com/python/cpython/issues/99277

   (8) https://github.com/python/cpython/issues/99248

   (9) https://github.com/python/cpython/issues/99155

   (10) https://github.com/python/cpython/issues/93464

   (11) https://github.com/python/cpython/issues/99134

   (12) https://github.com/python/cpython/issues/92584

   (13) https://peps.python.org/pep-0632/

   (14) https://github.com/python/cpython/issues/98999

   (15) https://github.com/python/cpython/issues/83004

   (16) https://github.com/python/cpython/issues/83004

   (17) https://github.com/python/cpython/issues/83004

   (18) https://github.com/python/cpython/issues/98897

   (19) https://github.com/python/cpython/issues/98878

   (20) https://github.com/python/cpython/issues/98139

   (21) https://github.com/python/cpython/issues/90352

   (22) https://github.com/python/cpython/issues/98793

   (23) https://github.com/python/cpython/issues/98744

   (24) https://github.com/python/cpython/issues/98740

   (25) https://github.com/python/cpython/issues/98703

   (26) https://github.com/python/cpython/issues/98624

   (27) https://github.com/python/cpython/issues/98658

   (28) https://github.com/python/cpython/issues/98284

   (29) https://github.com/python/cpython/issues/96151

   (30) https://github.com/python/cpython/issues/98086

   (31) https://github.com/python/cpython/issues/72719

   (32) https://peps.python.org/pep-0594/

   (33) https://github.com/python/cpython/issues/96192

   (34) https://github.com/python/cpython/issues/94172

   (35) https://github.com/python/cpython/issues/94172

   (36) https://github.com/python/cpython/issues/83638

   (37) https://peps.python.org/pep-0249/

   (38) https://github.com/python/cpython/issues/92452

   (39) https://github.com/python/cpython/issues/91803

   (40) https://bugs.python.org/issue?@action=redirect&bpo=38523

   (41) https://bugs.python.org/issue?@action=redirect&bpo=40358

   (42) https://bugs.python.org/issue?@action=redirect&bpo=36267


File: python.info,  Node: Documentation<26>,  Next: Tests<26>,  Prev: Library<76>,  Up: Python 3 12 0 alpha 2

1.24.32.6 Documentation
.......................

   - gh-98832(1): Changes wording of docstring for *note
     pathlib.Path.iterdir(): 26e.

   - gh-97966(2): Update uname docs to clarify the special nature of the
     platform attribute and to indicate when it became late-bound.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98832

   (2) https://github.com/python/cpython/issues/97966


File: python.info,  Node: Tests<26>,  Next: Build<31>,  Prev: Documentation<26>,  Up: Python 3 12 0 alpha 2

1.24.32.7 Tests
...............

   - gh-98903(1): The Python test suite now fails with exit code 4 if no
     tests ran.  It should help detecting typos in test names and test
     methods.

   - gh-98713(2): Fix a bug in the *note typing: 10a. tests where a test
     relying on CPython-specific implementation details was not
     decorated with ‘@cpython_only’ and was not skipped on other
     implementations.

   - gh-87390(3): Add tests for star-unpacking with PEP 646, and some
     other miscellaneous PEP 646 tests.

   - gh-96853(4): Added explicit coverage of ‘Py_Initialize’ (and hence
     ‘Py_InitializeEx’) back to the embedding tests (all other embedding
     tests migrated to ‘Py_InitializeFromConfig’ in Python 3.11)

   - bpo-34272(5): Some C API tests were moved into the new
     Lib/test/test_capi/ directory.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98903

   (2) https://github.com/python/cpython/issues/98713

   (3) https://github.com/python/cpython/issues/87390

   (4) https://github.com/python/cpython/issues/96853

   (5) https://bugs.python.org/issue?@action=redirect&bpo=34272


File: python.info,  Node: Build<31>,  Next: Windows<27>,  Prev: Tests<26>,  Up: Python 3 12 0 alpha 2

1.24.32.8 Build
...............

   - gh-99086(1): Fix ‘-Wimplicit-int’ compiler warning in ‘configure’
     check for ‘PTHREAD_SCOPE_SYSTEM’.

   - gh-99016(2): Fix build with ‘PYTHON_FOR_REGEN=python3.8’.

   - gh-97731(3): Specify the full path to the source location for ‘make
     docclean’ (needed for cross-builds).

   - gh-98949(4): Drop unused build dependency on ‘readelf’.

   - gh-98989(5): Use ‘python3.11’, if available, for regeneration and
     freezing.

   - gh-98831(6): Add new tooling, in ‘Tools/cases_generator’, to
     generate the interpreter switch statement from a list of opcode
     definitions.  This only affects adding, modifying or removing
     instruction definitions.  The instruction definitions now live in
     ‘Python/bytecodes.c’, in the form of a custom DSL (under
     development)(7).  The tooling reads this file and writes
     ‘Python/generated_cases.c.h’, which is then included by
     ‘Python/ceval.c’ to provide most of the cases of the main
     interpreter switch.

   - gh-98817(8): Remove PCbuild/lib.pyproj: it’s not used for anything,
     is only a minor convenience for Visual Studio users (who probably
     mostly don’t even know about it), and it takes a lot of maintenance
     effort to keep updated.

   - gh-98776(9): Fix ‘make regen-test-levenshtein’ for out-of-tree
     builds.

   - gh-98707(10): Don’t use vendored ‘libmpdec’ headers if *note
     -with-system-libmpdec: 657. is passed to ‘configure’.  Don’t use
     vendored ‘libexpat’ headers if *note -with-system-expat: 1b15. is
     passed to ‘configure’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/99086

   (2) https://github.com/python/cpython/issues/99016

   (3) https://github.com/python/cpython/issues/97731

   (4) https://github.com/python/cpython/issues/98949

   (5) https://github.com/python/cpython/issues/98989

   (6) https://github.com/python/cpython/issues/98831

   (7) 
https://github.com/faster-cpython/ideas/blob/main/3.12/interpreter_definition.md

   (8) https://github.com/python/cpython/issues/98817

   (9) https://github.com/python/cpython/issues/98776

   (10) https://github.com/python/cpython/issues/98707


File: python.info,  Node: Windows<27>,  Next: macOS<18>,  Prev: Build<31>,  Up: Python 3 12 0 alpha 2

1.24.32.9 Windows
.................

   - gh-98689(1): Update Windows builds to zlib v1.2.13.  v1.2.12 has
     CVE 2022-37434(2), but the vulnerable ‘inflateGetHeader’ API is not
     used by Python.

   - gh-98790(3): Assumes that a missing ‘DLLs’ directory means that
     standard extension modules are in the executable’s directory.

   - gh-98745(4): Update ‘py.exe’ launcher to install 3.11 by default
     and 3.12 on request.

   - gh-98692(5): Fix the *note Python install manager: 7db. ignoring
     unrecognized shebang lines instead of treating them as local paths

   - gh-94328(6): Update Windows installer to use SQLite 3.39.4.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98689

   (2) https://www.cve.org/CVERecord?id=CVE-2022-37434

   (3) https://github.com/python/cpython/issues/98790

   (4) https://github.com/python/cpython/issues/98745

   (5) https://github.com/python/cpython/issues/98692

   (6) https://github.com/python/cpython/issues/94328


File: python.info,  Node: macOS<18>,  Next: C API<28>,  Prev: Windows<27>,  Up: Python 3 12 0 alpha 2

1.24.32.10 macOS
................

   - gh-94328(1): Update macOS installer to SQLite 3.39.4.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94328


File: python.info,  Node: C API<28>,  Prev: macOS<18>,  Up: Python 3 12 0 alpha 2

1.24.32.11 C API
................

   - gh-98724(1): The *note Py_CLEAR: 799, *note Py_SETREF: 79a. and
     *note Py_XSETREF: 79b. macros now only evaluate their argument
     once.  If the argument has side effects, these side effects are no
     longer duplicated.  Patch by Victor Stinner.

   - gh-98978(2): Fix use-after-free in ‘Py_SetPythonHome(NULL)’,
     ‘Py_SetProgramName(NULL)’ and ‘_Py_SetProgramFullPath(NULL)’
     function calls.  Issue reported by Benedikt Reinartz.  Patch by
     Victor Stinner.

   - gh-98410(3): Add ‘getbufferproc’ and ‘releasebufferproc’ to the
     stable API.

   - gh-98610(4): Some configurable capabilities of sub-interpreters
     have changed.  They always allow subprocesses (*note subprocess:
     dc.) now, whereas before subprocesses could be optionally
     disallowed for a sub-interpreter.  Instead ‘os.exec()’ can now be
     disallowed.  Disallowing daemon threads is now supported.
     Disallowing all threads is still allowed, but is never done by
     default.  Note that the optional restrictions are only available
     through ‘_Py_NewInterpreterFromConfig()’, which isn’t a public API.
     They do not affect the main interpreter, nor *note
     Py_NewInterpreter(): 1b19.

   - gh-98608(5): A ‘_PyInterpreterConfig’ has been added and
     ‘_Py_NewInterpreter()’ has been renamed to
     ‘_Py_NewInterpreterFromConfig()’.  The «isolated_subinterpreters»
     argument is now a granular config that captures the previous
     behavior.  Note that this is all «private» API.

   - gh-96853(6): ‘Py_InitializeEx’ now correctly calls ‘PyConfig_Clear’
     after initializing the interpreter (the omission didn’t cause a
     memory leak only because none of the dynamically allocated config
     fields are populated by the wrapper function)

   - gh-91248(7): Add *note PyFrame_GetVar(): 78a. and *note
     PyFrame_GetVarString(): 78b. functions to get a frame variable by
     its name.  Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98724

   (2) https://github.com/python/cpython/issues/98978

   (3) https://github.com/python/cpython/issues/98410

   (4) https://github.com/python/cpython/issues/98610

   (5) https://github.com/python/cpython/issues/98608

   (6) https://github.com/python/cpython/issues/96853

   (7) https://github.com/python/cpython/issues/91248


File: python.info,  Node: Python 3 12 0 alpha 1,  Next: Python 3 11 0 beta 1,  Prev: Python 3 12 0 alpha 2,  Up: Changelog

1.24.33 Python 3.12.0 alpha 1
-----------------------------

'Release date: 2022-10-25'

* Menu:

* Security: Security<27>.
* Core and Builtins: Core and Builtins<73>.
* Library: Library<77>.
* Core and Builtins: Core and Builtins<74>.
* Library: Library<78>.
* Core and Builtins: Core and Builtins<75>.
* Library: Library<79>.
* Core and Builtins: Core and Builtins<76>.
* Library: Library<80>.
* Core and Builtins: Core and Builtins<77>.
* Library: Library<81>.
* Core and Builtins: Core and Builtins<78>.
* Library: Library<82>.
* Core and Builtins: Core and Builtins<79>.
* Library: Library<83>.
* Core and Builtins: Core and Builtins<80>.
* Library: Library<84>.
* Core and Builtins: Core and Builtins<81>.
* Library: Library<85>.
* Core and Builtins: Core and Builtins<82>.
* Library: Library<86>.
* Documentation: Documentation<27>.
* Tests: Tests<27>.
* Build: Build<32>.
* Windows: Windows<28>.
* macOS: macOS<19>.
* IDLE: IDLE<15>.
* Tools/Demos: Tools/Demos<24>.
* C API: C API<29>.


File: python.info,  Node: Security<27>,  Next: Core and Builtins<73>,  Up: Python 3 12 0 alpha 1

1.24.33.1 Security
..................

   - gh-97616(1): Fix multiplying a list by an integer (‘list *= int’):
     detect the integer overflow when the new allocated length is close
     to the maximum size.  Issue reported by Jordan Limor.  Patch by
     Victor Stinner.

   - gh-97514(2): On Linux the *note multiprocessing: 98. module returns
     to using filesystem backed unix domain sockets for communication
     with the 'forkserver' process instead of the Linux abstract socket
     namespace.  Only code that chooses to use the *note «forkserver»
     start method: 1d5. is affected.

     Abstract sockets have no permissions and could allow any user on
     the system in the same network namespace(3) (often the whole
     system) to inject code into the multiprocessing 'forkserver'
     process.  This was a potential privilege escalation.  Filesystem
     based socket permissions restrict this to the 'forkserver' process
     user as was the default in Python 3.8 and earlier.

     This prevents Linux CVE 2022-42919(4).

   - gh-87389(5): *note http.server: 76.: Fix an open redirection
     vulnerability in the HTTP server when an URI path starts with ‘//’.
     Vulnerability discovered, and initial fix proposed, by Hamza Avvan.

   - gh-79096(6): LWPCookieJar and MozillaCookieJar create files with
     file mode 600 instead of 644 (Microsoft Windows is not affected)

   - gh-92888(7): Fix ‘memoryview’ use after free when accessing the
     backing buffer in certain cases.

   - gh-68966(8): The deprecated mailcap module now refuses to inject
     unsafe text (filenames, MIME types, parameters) into shell
     commands.  Instead of using such text, it will warn and act as if a
     match was not found (or for test commands, as if the test failed).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97616

   (2) https://github.com/python/cpython/issues/97514

   (3) https://man7.org/linux/man-pages/man7/network_namespaces.7.html

   (4) https://www.cve.org/CVERecord?id=CVE-2022-42919

   (5) https://github.com/python/cpython/issues/87389

   (6) https://github.com/python/cpython/issues/79096

   (7) https://github.com/python/cpython/issues/92888

   (8) https://github.com/python/cpython/issues/68966


File: python.info,  Node: Core and Builtins<73>,  Next: Library<77>,  Prev: Security<27>,  Up: Python 3 12 0 alpha 1

1.24.33.2 Core and Builtins
...........................

   - gh-98374(1): Suppress ImportError for invalid query for help()
     command.  Patch by Donghee Na.

   - gh-98461(2): Fix source location in bytecode for list, set and dict
     comprehensions as well as generator expressions.

   - gh-98354(3): Added unicode check for ‘name’ attribute of ‘spec’
     argument passed in ‘_imp.create_builtin()’ function.

   - gh-98398(4): Fix source location of “assert” bytecodes.

   - gh-98390(5): Fix location of sub-expressions of boolean
     expressions, by reducing their scope to that of the sub-expression.

   - gh-98254(6): Modules from the standard library are now potentially
     suggested as part of the error messages displayed by the
     interpreter when an *note NameError: 452. is raised to the top
     level.  Patch by Pablo Galindo

   - gh-97997(7): Add running column offset to the tokenizer state to
     avoid calculating AST column information with pointer arithmetic.

   - gh-97973(8): Modify the tokenizer to return all necessary
     information the parser needs to set location information in the AST
     nodes, so that the parser does not have to calculate those doing
     pointer arithmetic.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98374

   (2) https://github.com/python/cpython/issues/98461

   (3) https://github.com/python/cpython/issues/98354

   (4) https://github.com/python/cpython/issues/98398

   (5) https://github.com/python/cpython/issues/98390

   (6) https://github.com/python/cpython/issues/98254

   (7) https://github.com/python/cpython/issues/97997

   (8) https://github.com/python/cpython/issues/97973


File: python.info,  Node: Library<77>,  Next: Core and Builtins<74>,  Prev: Core and Builtins<73>,  Up: Python 3 12 0 alpha 1

1.24.33.3 Library
.................

   - gh-96078(1): *note os.sched_yield(): 1319. now release the GIL
     while calling sched_yield(2).  Patch by Donghee Na.

   - gh-97955(2): Migrate *note zoneinfo: 13a. to Argument Clinic.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/96078

   (2) https://github.com/python/cpython/issues/97955


File: python.info,  Node: Core and Builtins<74>,  Next: Library<78>,  Prev: Library<77>,  Up: Python 3 12 0 alpha 1

1.24.33.4 Core and Builtins
...........................

   - gh-97912(1): The compiler now avoids quadratic behavior when
     finding which instructions should use the *note LOAD_FAST_CHECK:
     70c. opcode.

   - gh-97002(2): Fix an issue where several frame objects could be
     backed by the same interpreter frame, possibly leading to corrupted
     memory and hard crashes of the interpreter.

   - gh-97943(3): Bugfix: *note PyFunction_GetAnnotations(): 1b1f.
     should return a borrowed reference.  It was returning a new
     reference.

   - gh-97922(4): The Garbage Collector now runs only on the eval
     breaker mechanism of the Python bytecode evaluation loop instead on
     object allocations.  The GC can also run when *note
     PyErr_CheckSignals(): 694. is called so C extensions that need to
     run for a long time without executing any Python code also have a
     chance to execute the GC periodically.

   - gh-65961(5): When ‘__package__’ is different than
     ‘__spec__.parent’, raise a ‘DeprecationWarning’ instead of
     ‘ImportWarning’.

     Also remove ‘importlib.util.set_package()’ which was scheduled for
     removal.

   - gh-97850(6): Long deprecated, ‘module_repr()’ should now be
     completely eradicated.

   - gh-86298(7): In cases where ‘warnings.warn_explicit()’ consults the
     module’s loader, an ‘DeprecationWarning’ is issued when
     ‘m.__loader__’ differs from ‘m.__spec__.loader’.

   - gh-97779(8): Ensure that all Python frame objects are backed by
     «complete» frames.

   - gh-91052(9): Add API for subscribing to modification events on
     selected dictionaries.

   - gh-97752(10): Fix possible data corruption or crashes when
     accessing the ‘f_back’ member of newly-created generator or
     coroutine frames.

   - gh-97591(11): Fixed a missing incref/decref pair in
     ‘Exception.__setstate__()’.  Patch by Ofey Chan.

   - gh-97670(12): Remove the ‘sys.getdxp()’ function and the
     ‘Tools/scripts/analyze_dxp.py’ script.  DXP stands for «dynamic
     execution pairs».  They were related to ‘DYNAMIC_EXECUTION_PROFILE’
     and ‘DXPAIRS’ macros which have been removed in Python 3.11.
     Python can now be built with *note ./configure -enable-pystats:
     1b20. to gather statistics on Python opcodes.  Patch by Victor
     Stinner.

   - gh-94526(13): Fix the Python path configuration used to initialized
     *note sys.path: 3e4. at Python startup.  Paths are no longer
     encoded to UTF-8/strict to avoid encoding errors if it contains
     surrogate characters (bytes paths are decoded with the
     surrogateescape error handler).  Patch by Victor Stinner.

   - gh-96670(14): The parser now raises *note SyntaxError: 18e. when
     parsing source code containing null bytes.  Patch by Pablo Galindo

   - gh-96975(15): Fix a crash occurring when *note PyEval_GetFrame():
     1b21. is called while the topmost Python frame is in a
     partially-initialized state.

   - gh-96848(16): Fix command line parsing: reject *note -X
     int_max_str_digits: 16f. option with no value (invalid) when the
     *note PYTHONINTMAXSTRDIGITS: 1b22. environment variable is set to a
     valid limit.  Patch by Victor Stinner.

   - gh-95921(17): Fix overly-broad source position information for
     chained comparisons used as branching conditions.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97912

   (2) https://github.com/python/cpython/issues/97002

   (3) https://github.com/python/cpython/issues/97943

   (4) https://github.com/python/cpython/issues/97922

   (5) https://github.com/python/cpython/issues/65961

   (6) https://github.com/python/cpython/issues/97850

   (7) https://github.com/python/cpython/issues/86298

   (8) https://github.com/python/cpython/issues/97779

   (9) https://github.com/python/cpython/issues/91052

   (10) https://github.com/python/cpython/issues/97752

   (11) https://github.com/python/cpython/issues/97591

   (12) https://github.com/python/cpython/issues/97670

   (13) https://github.com/python/cpython/issues/94526

   (14) https://github.com/python/cpython/issues/96670

   (15) https://github.com/python/cpython/issues/96975

   (16) https://github.com/python/cpython/issues/96848

   (17) https://github.com/python/cpython/issues/95921


File: python.info,  Node: Library<78>,  Next: Core and Builtins<75>,  Prev: Core and Builtins<74>,  Up: Python 3 12 0 alpha 1

1.24.33.5 Library
.................

   - gh-96821(1): Fix undefined behaviour in ‘audioop.c’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/96821


File: python.info,  Node: Core and Builtins<75>,  Next: Library<79>,  Prev: Library<78>,  Up: Python 3 12 0 alpha 1

1.24.33.6 Core and Builtins
...........................

   - gh-96821(1): Fix undefined behaviour in ‘_testcapimodule.c’.

   - gh-95778(2): When *note ValueError: 2ec. is raised if an integer is
     larger than the limit, mention the *note
     sys.set_int_max_str_digits(): 18d9. function in the error message.
     Patch by Victor Stinner.

   - gh-96387(3): At Python exit, sometimes a thread holding the GIL can
     wait forever for a thread (usually a daemon thread) which requested
     to drop the GIL, whereas the thread already exited.  To fix the
     race condition, the thread which requested the GIL drop now resets
     its request before exiting.  Issue discovered and analyzed by
     Mingliang ZHAO. Patch by Victor Stinner.

   - gh-96864(4): Fix a possible assertion failure, fatal error, or
     *note SystemError: 796. if a line tracing event raises an exception
     while opcode tracing is enabled.

   - gh-95778(5): The ‘PyLong_FromString’ function was refactored to
     make it more maintainable and extensible.

   - gh-96678(6): Fix undefined behaviour in C code of null pointer
     arithmetic.

   - gh-96754(7): Make sure that all frame objects created are created
     from valid interpreter frames.  Prevents the possibility of invalid
     frames in backtraces and signal handlers.

   - gh-90997(8): Improve the performance of reading and writing inline
     bytecode caches on some platforms.

   - gh-96751(9): Remove dead code from ‘CALL_FUNCTION_EX’ opcode.

   - gh-90751(10): *note memoryview: 165. now supports half-floats.
     Patch by Donghee Na and Antoine Pitrou.

   - gh-96678(11): Fix case of undefined behavior in ceval.c

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/96821

   (2) https://github.com/python/cpython/issues/95778

   (3) https://github.com/python/cpython/issues/96387

   (4) https://github.com/python/cpython/issues/96864

   (5) https://github.com/python/cpython/issues/95778

   (6) https://github.com/python/cpython/issues/96678

   (7) https://github.com/python/cpython/issues/96754

   (8) https://github.com/python/cpython/issues/90997

   (9) https://github.com/python/cpython/issues/96751

   (10) https://github.com/python/cpython/issues/90751

   (11) https://github.com/python/cpython/issues/96678


File: python.info,  Node: Library<79>,  Next: Core and Builtins<76>,  Prev: Core and Builtins<75>,  Up: Python 3 12 0 alpha 1

1.24.33.7 Library
.................

   - gh-64373(1): Convert ‘_functools’ to argument clinic.

   - gh-96641(2): Do not expose ‘KeyWrapper’ in ‘_functools’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/64373

   (2) https://github.com/python/cpython/issues/96641


File: python.info,  Node: Core and Builtins<76>,  Next: Library<80>,  Prev: Library<79>,  Up: Python 3 12 0 alpha 1

1.24.33.8 Core and Builtins
...........................

   - gh-96636(1): Ensure that tracing, ‘sys.setrace()’, is turned on
     immediately.  In pre-release versions of 3.11, some tracing events
     might have been lost when turning on tracing in a ‘__del__’ method
     or interrupt.

   - gh-96572(2): Fix use after free in trace refs build mode.  Patch by
     Kumar Aditya.

   - gh-96611(3): When loading a file with invalid UTF-8 inside a
     multi-line string, a correct SyntaxError is emitted.

   - gh-96612(4): Make sure that incomplete frames do not show up in
     tracemalloc traces.

   - gh-90230(5): Fix compiler warnings and test failures when building
     with ‘--enable-pystats’.

   - gh-96587(6): Correctly raise ‘SyntaxError’ on exception groups (
     PEP 654(7)) on python versions prior to 3.11

   - gh-96569(8): Remove two cases of undefined behavior, by adding NULL
     checks.

   - gh-96582(9): Fix possible ‘NULL’ pointer dereference in
     ‘_PyThread_CurrentFrames’.  Patch by Kumar Aditya.

   - gh-91079(10): Separate Python recursion checking from C recursion
     checking which reduces the chance of C stack overflow and allows
     the recursion limit to be increased safely.

   - gh-93911(11): Fix an issue that could prevent *note LOAD_ATTR: 705.
     from specializing properly when accessing properties.

   - gh-96348(12): Emit a DeprecationWarning when *note throw(): 71d,
     *note throw(): 71c. or *note athrow(): 71e. are called with more
     than one argument.

   - gh-95196(13): Disable incorrect pickling of the C implemented
     classmethod descriptors.

   - gh-96364(14): Fix text signatures of ‘list.__getitem__’ and
     ‘dict.__getitem__’.

   - gh-96352(15): Fix *note AttributeError: 5f0. missing ‘name’ and
     ‘obj’ attributes in *note object.__getattribute__(): dcd.  Patch by
     Philip Georgi.

   - gh-93554(16): Change the jump opcodes so that all conditional jumps
     are forward jumps.  Backward jumps are converted by the assembler
     into a conditional forward jump whose target is the fallthrough
     block (and with a reversed condition), followed by an unconditional
     backward jump.  For example:

     ‘POP_JUMP_IF_TRUE BACKWARD_TARGET’ becomes ‘POP_JUMP_IF_FALSE
     NEXT_BLOCK; JUMP BACKWARD_TARGET’.

     All the directed conditional jump opcodes were removed:
     ‘POP_JUMP_FORWARD_IF_TRUE’, ‘POP_JUMP_BACKWARD_IF_TRUE’,
     ‘POP_JUMP_FORWARD_IF_FALSE’, ‘POP_JUMP_BACKWARD_IF_FALSE’,
     ‘POP_JUMP_FORWARD_IF_NONE’, ‘POP_JUMP_BACKWARD_IF_NONE’,
     ‘POP_JUMP_FORWARD_IF_NOT_NONE’, ‘POP_JUMP_BACKWARD_IF_NOT_NONE’.

     The corresponding opcodes without direction are no longer
     pseudo-instructions, and they implement the forward conditional
     jumps.

   - gh-96268(17): Loading a file with invalid UTF-8 will now report the
     broken character at the correct location.

   - gh-96237(18): The internal field ‘_PyInterpreterFrame.f_func’ is
     renamed to ‘_PyInterpreterFrame.f_funcobj’ and may be any object.
     The ‘f_globals’ and ‘f_builtin’ fields may hold junk values.

     It is safest to treat the ‘_PyInterpreterFrame’ struct as opaque.

   - gh-96187(19): Fixed a bug that caused ‘_PyCode_GetExtra’ to return
     garbage for negative indexes.  Patch by Pablo Galindo

   - gh-96143(20): Add a new ‘-X perf’ Python command line option as
     well as *note sys.activate_stack_trampoline(): 69b. and *note
     sys.deactivate_stack_trampoline(): 69c. function in the *note sys:
     df. module that allows to set/unset the interpreter in a way that
     the Linux ‘perf’ profiler can detect Python calls.  The new *note
     sys.is_stack_trampoline_active(): 69d. function allows to query the
     state of the perf trampoline.  Design by Pablo Galindo.  Patch by
     Pablo Galindo and Christian Heimes with contributions from Gregory
     P. Smith [Google] and Mark Shannon.

   - gh-96071(21): Fix a deadlock in *note PyGILState_Ensure(): 64a.
     when allocating new thread state.  Patch by Kumar Aditya.

   - gh-96046(22): *note PyType_Ready(): 981. now initializes
     ‘ht_cached_keys’ and performs additional checks to ensure that type
     objects are properly configured.  This avoids crashes in 3rd party
     packages that don’t use regular API to create new types.

   - gh-96005(23): On WASI *note ENOTCAPABLE: 1b27. is now mapped to
     *note PermissionError: f40.  The *note errno: 5b. modules exposes
     the new error number.  ‘getpath.py’ now ignores *note
     PermissionError: f40. when it cannot open landmark files
     ‘pybuilddir.txt’ and ‘pyenv.cfg’.

   - gh-93678(24): Added test a harness for direct unit tests of the
     compiler’s optimization stage.  The
     ‘_testinternalcapi.optimize_cfg()’ function runs the optimiser on a
     sequence of instructions.  The ‘CfgOptimizationTestCase’ class in
     ‘test.support’ has utilities for invoking the optimizer and
     checking the output.

   - gh-95245(25): Reduces the size of a «simple» Python object from 8
     to 6 words by moving the weakreflist pointer into the pre-header
     directly before the object’s dict/values pointer.

   - gh-90997(26): Compile virtual *note try: 8f9./*note except: 1ab.
     blocks to handle exceptions raised during *note close(): 177b. or
     *note throw(): 71d. calls through a suspended frame.

   - gh-95977(27): Optimized calling *note __get__(): 16ef. with
     vectorcall.  Patch by Kumar Aditya.

   - gh-91210(28): Improve error message when a parameter without a
     default value follows one with a default value, and show the same
     message, even when the non-default/default sequence is preceded by
     positional-only parameters.

   - gh-95922(29): Fixed bug where the compiler’s
     ‘eliminate_empty_basic_blocks’ function ignores the last block of
     the code unit.

   - gh-95818(30): Skip over incomplete frames in *note
     PyThreadState_GetFrame(): 992.

   - gh-95876(31): Fix format string in
     ‘_PyPegen_raise_error_known_location’ that can lead to memory
     corruption on some 64bit systems.  The function was building a
     tuple with ‘i’ (int) instead of ‘n’ (Py_ssize_t) for Py_ssize_t
     arguments.

   - gh-95605(32): Fix misleading contents of error message when
     converting an all-whitespace string to *note float: 196.

   - gh-95150(33): Update code object hashing and equality to consider
     all debugging and exception handling tables.  This fixes an issue
     where certain non-identical code objects could be «deduplicated»
     during compilation.

   - gh-91146(34): Reduce allocation size of *note list: 24d. from *note
     str.split(): 10ac. and *note str.rsplit(): 145d.  Patch by Donghee
     Na and Inada Naoki.

   - gh-87092(35): Create a “jump target label” abstraction in the
     compiler so that the compiler’s codegen stage does not work
     directly with basic blocks.  This prepares the code for changes to
     the underlying CFG generation mechanism.

   - gh-95355(36): ‘_PyPegen_Parser_New’ now properly detects token
     memory allocation errors.  Patch by Honglin Zhu.

   - gh-90081(37): Run Python code in tracer/profiler function at full
     speed.  Fixes slowdown in earlier versions of 3.11.

   - gh-95324(38): Emit a warning in debug mode if an object does not
     call *note PyObject_GC_UnTrack(): 170c. before deallocation.  Patch
     by Pablo Galindo.

   - gh-95245(39): Merge managed dict and values pointer into a single
     tagged pointer to save one word in the pre-header.

   - gh-93678(40): Add cfg_builder struct and refactor the relevant code
     so that a cfg can be constructed without an instance of the
     compiler struct.

   - gh-95185(41): Prevented crashes in the AST constructor when
     compiling some absurdly long expressions like ‘"+0"*1000000’.
     *note RecursionError: f6a. is now raised instead.  Patch by Pablo
     Galindo

   - gh-93351(42): *note ast.AST: 4c4. node positions are now validated
     when provided to *note compile(): 4b2. and other related functions.
     If invalid positions are detected, a *note ValueError: 2ec. will be
     raised.

   - gh-94438(43): Fix an issue that caused extended opcode arguments
     and some conditional pops to be ignored when calculating valid jump
     targets for assignments to the ‘f_lineno’ attribute of frame
     objects.  In some cases, this could cause inconsistent internal
     state, resulting in a hard crash of the interpreter.

   - gh-95060(44): Undocumented ‘PyCode_Addr2Location’ function now
     properly returns when ‘addrq’ argument is less than zero.

   - gh-95113(45): Replace all ‘EXTENDED_ARG_QUICK’ instructions with
     basic *note EXTENDED_ARG: 1b06. instructions in unquickened code.
     Consumers of non-adaptive bytecode should be able to handle
     extended arguments the same way they were handled in CPython 3.10
     and older.

   - gh-91409(46): Fix incorrect source location info caused by certain
     optimizations in the bytecode compiler.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/96636

   (2) https://github.com/python/cpython/issues/96572

   (3) https://github.com/python/cpython/issues/96611

   (4) https://github.com/python/cpython/issues/96612

   (5) https://github.com/python/cpython/issues/90230

   (6) https://github.com/python/cpython/issues/96587

   (7) https://peps.python.org/pep-0654/

   (8) https://github.com/python/cpython/issues/96569

   (9) https://github.com/python/cpython/issues/96582

   (10) https://github.com/python/cpython/issues/91079

   (11) https://github.com/python/cpython/issues/93911

   (12) https://github.com/python/cpython/issues/96348

   (13) https://github.com/python/cpython/issues/95196

   (14) https://github.com/python/cpython/issues/96364

   (15) https://github.com/python/cpython/issues/96352

   (16) https://github.com/python/cpython/issues/93554

   (17) https://github.com/python/cpython/issues/96268

   (18) https://github.com/python/cpython/issues/96237

   (19) https://github.com/python/cpython/issues/96187

   (20) https://github.com/python/cpython/issues/96143

   (21) https://github.com/python/cpython/issues/96071

   (22) https://github.com/python/cpython/issues/96046

   (23) https://github.com/python/cpython/issues/96005

   (24) https://github.com/python/cpython/issues/93678

   (25) https://github.com/python/cpython/issues/95245

   (26) https://github.com/python/cpython/issues/90997

   (27) https://github.com/python/cpython/issues/95977

   (28) https://github.com/python/cpython/issues/91210

   (29) https://github.com/python/cpython/issues/95922

   (30) https://github.com/python/cpython/issues/95818

   (31) https://github.com/python/cpython/issues/95876

   (32) https://github.com/python/cpython/issues/95605

   (33) https://github.com/python/cpython/issues/95150

   (34) https://github.com/python/cpython/issues/91146

   (35) https://github.com/python/cpython/issues/87092

   (36) https://github.com/python/cpython/issues/95355

   (37) https://github.com/python/cpython/issues/90081

   (38) https://github.com/python/cpython/issues/95324

   (39) https://github.com/python/cpython/issues/95245

   (40) https://github.com/python/cpython/issues/93678

   (41) https://github.com/python/cpython/issues/95185

   (42) https://github.com/python/cpython/issues/93351

   (43) https://github.com/python/cpython/issues/94438

   (44) https://github.com/python/cpython/issues/95060

   (45) https://github.com/python/cpython/issues/95113

   (46) https://github.com/python/cpython/issues/91409


File: python.info,  Node: Library<80>,  Next: Core and Builtins<77>,  Prev: Core and Builtins<76>,  Up: Python 3 12 0 alpha 1

1.24.33.9 Library
.................

   - gh-95023(1): Implement *note os.setns(): 1b29. and *note
     os.unshare(): 1b2a. for Linux.  Patch by Noam Cohen.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/95023


File: python.info,  Node: Core and Builtins<77>,  Next: Library<81>,  Prev: Library<80>,  Up: Python 3 12 0 alpha 1

1.24.33.10 Core and Builtins
............................

   - gh-94036(1): Fix incorrect source location info for some multi-line
     attribute accesses and method calls.

   - gh-94938(2): Fix error detection in some builtin functions when
     keyword argument name is an instance of a str subclass with
     overloaded ‘__eq__’ and ‘__hash__’.  Previously it could cause
     SystemError or other undesired behavior.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94036

   (2) https://github.com/python/cpython/issues/94938


File: python.info,  Node: Library<81>,  Next: Core and Builtins<78>,  Prev: Core and Builtins<77>,  Up: Python 3 12 0 alpha 1

1.24.33.11 Library
..................

   - gh-94996(1): *note ast.parse(): 1c2. will no longer parse function
     definitions with positional-only params when passed
     ‘feature_version’ less than ‘(3, 8)’.  Patch by Shantanu Jain.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94996


File: python.info,  Node: Core and Builtins<78>,  Next: Library<82>,  Prev: Library<81>,  Up: Python 3 12 0 alpha 1

1.24.33.12 Core and Builtins
............................

   - gh-94739(1): Allow jumping within, out of, and across exception
     handlers in the debugger.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94739


File: python.info,  Node: Library<82>,  Next: Core and Builtins<79>,  Prev: Core and Builtins<78>,  Up: Python 3 12 0 alpha 1

1.24.33.13 Library
..................

   - gh-94949(1): *note ast.parse(): 1c2. will no longer parse
     parenthesized context managers when passed ‘feature_version’ less
     than ‘(3, 9)’.  Patch by Shantanu Jain.

   - gh-94947(2): *note ast.parse(): 1c2. will no longer parse
     assignment expressions when passed ‘feature_version’ less than ‘(3,
     8)’.  Patch by Shantanu Jain.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/94949

   (2) https://github.com/python/cpython/issues/94947


File: python.info,  Node: Core and Builtins<79>,  Next: Library<83>,  Prev: Library<82>,  Up: Python 3 12 0 alpha 1

1.24.33.14 Core and Builtins
............................

   - gh-91256(1): Ensures the program name is known for help text during
     interpreter startup.

   - gh-94869(2): Fix the column offsets for some expressions in
     multi-line f-strings *note ast: 9. nodes.  Patch by Pablo Galindo.

   - gh-94893(3): Fix an issue where frame object manipulations could
     corrupt inline bytecode caches.

   - gh-94822(4): Fix an issue where lookups of metaclass descriptors
     may be ignored when an identically-named attribute also exists on
     the class itself.

   - gh-91153(5): Fix an issue where a *note bytearray: 344. item
     assignment could crash if it’s resized by the new value’s
     ‘__index__()’ method.

   - gh-90699(6): Fix reference counting bug in ‘bool.__repr__()’.
     Patch by Kumar Aditya.

   - gh-94694(7): Fix an issue that could cause code with multi-line
     method lookups to have misleading or incorrect column offset
     information.  In some cases (when compiling a hand-built AST) this
     could have resulted in a hard crash of the interpreter.

   - gh-93252(8): Fix an issue that caused internal frames to outlive
     failed Python function calls, possibly resulting in memory leaks or
     hard interpreter crashes.

   - gh-94215(9): Fix an issue where exceptions raised by line-tracing
     events would cause frames to be left in an invalid state, possibly
     resulting in a hard crash of the interpreter.

   - gh-92228(10): Disable the compiler’s inline-small-exit-blocks
     optimization for exit blocks that are associated with source code
     lines.  This fixes a bug where the debugger cannot tell where an
     exception handler ends and the following code block begins.

   - gh-94485(11): Line number of a module’s ‘RESUME’ instruction is set
     to 0 as specified in PEP 626(12).

   - gh-94438(13): Account for instructions that can push NULL to the
     stack when setting line number in a frame.  Prevents some
     (unlikely) crashes.

   - gh-91719(14): Reload ‘opcode’ when raising ‘unknown opcode error’
     in the interpreter main loop, for C compilers to generate
     dispatching code independently.

   - gh-94329(15): Compile and run code with unpacking of extremely
     large sequences (1000s of elements).  Such code failed to compile.
     It now compiles and runs correctly.

   - gh-94360(16): Fixed a tokenizer crash when reading encoded files
     with syntax errors from ‘stdin’ with non utf-8 encoded text.  Patch
     by Pablo Galindo

   - gh-88116(17): Fix an issue when reading line numbers from code
     objects if the encoded line numbers are close to ‘INT_MIN’.  Patch
     by Pablo Galindo

   - gh-94262(18): Don’t create frame objects for incomplete frames.
     Prevents the creation of generators and closures from being
     observable to Python and C extensions, restoring the behavior of
     3.10 and earlier.

   - gh-94192(19): Fix error for dictionary literals with invalid
     expression as value.

   - gh-87995(20): *note types.MappingProxyType: 699. instances are now
     hashable if the underlying mapping is hashable.

   - gh-93883(21): Revise the display strategy of traceback enhanced
     error locations.  The indicators are only shown when the location
     doesn’t span the whole line.

   - gh-94163(22): Add *note BINARY_SLICE: 706. and *note STORE_SLICE:
     707. instructions for more efficient handling and better
     specialization of slicing operations, where the slice is explicit
     in the source code.

   - gh-94021(23): Fix unreachable code warning in
     ‘Python/specialize.c’.

   - gh-93911(24): Specialize ‘LOAD_ATTR’ for objects with custom
     ‘__getattribute__’.

   - gh-93955(25): Improve performance of attribute lookups on objects
     with custom ‘__getattribute__’ and ‘__getattr__’.  Patch by Ken
     Jin.

   - gh-93911(26): Specialize ‘LOAD_ATTR’ for ‘property()’ attributes.

   - gh-93678(27): Refactor compiler optimisation code so that it no
     longer needs the ‘struct assembler’ and ‘struct compiler’ passed
     around.  Instead, each function takes the CFG and other data that
     it actually needs.  This will make it possible to test this code
     directly.

   - gh-93841(28): When built with ‘-enable-pystats’, ‘sys._stats_on()’,
     ‘sys._stats_off()’, ‘sys._stats_clear()’ and ‘sys._stats_dump()’
     functions have been added to enable gathering stats for parts of
     programs.

   - gh-93516(29): Store offset of first traceable instruction in code
     object to avoid having to recompute it for each instruction when
     tracing.

   - gh-93516(30): Lazily create a table mapping bytecode offsets to
     line numbers to speed up calculation of line numbers when tracing.

   - gh-89828(31): *note types.GenericAlias: 9ee. no longer relays the
     ‘__class__’ attribute.  For example, ‘isinstance(list[int], type)’
     no longer returns ‘True’.

   - gh-93678(32): Refactor the compiler to reduce boilerplate and
     repetition.

   - gh-93671(33): Fix some exponential backtrace case happening with
     deeply nested sequence patterns in match statements.  Patch by
     Pablo Galindo

   - gh-93662(34): Make sure that the end column offsets are correct in
     multi-line method calls.  Previously, the end column could precede
     the column offset.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91256

   (2) https://github.com/python/cpython/issues/94869

   (3) https://github.com/python/cpython/issues/94893

   (4) https://github.com/python/cpython/issues/94822

   (5) https://github.com/python/cpython/issues/91153

   (6) https://github.com/python/cpython/issues/90699

   (7) https://github.com/python/cpython/issues/94694

   (8) https://github.com/python/cpython/issues/93252

   (9) https://github.com/python/cpython/issues/94215

   (10) https://github.com/python/cpython/issues/92228

   (11) https://github.com/python/cpython/issues/94485

   (12) https://peps.python.org/pep-0626/

   (13) https://github.com/python/cpython/issues/94438

   (14) https://github.com/python/cpython/issues/91719

   (15) https://github.com/python/cpython/issues/94329

   (16) https://github.com/python/cpython/issues/94360

   (17) https://github.com/python/cpython/issues/88116

   (18) https://github.com/python/cpython/issues/94262

   (19) https://github.com/python/cpython/issues/94192

   (20) https://github.com/python/cpython/issues/87995

   (21) https://github.com/python/cpython/issues/93883

   (22) https://github.com/python/cpython/issues/94163

   (23) https://github.com/python/cpython/issues/94021

   (24) https://github.com/python/cpython/issues/93911

   (25) https://github.com/python/cpython/issues/93955

   (26) https://github.com/python/cpython/issues/93911

   (27) https://github.com/python/cpython/issues/93678

   (28) https://github.com/python/cpython/issues/93841

   (29) https://github.com/python/cpython/issues/93516

   (30) https://github.com/python/cpython/issues/93516

   (31) https://github.com/python/cpython/issues/89828

   (32) https://github.com/python/cpython/issues/93678

   (33) https://github.com/python/cpython/issues/93671

   (34) https://github.com/python/cpython/issues/93662


File: python.info,  Node: Library<83>,  Next: Core and Builtins<80>,  Prev: Core and Builtins<79>,  Up: Python 3 12 0 alpha 1

1.24.33.15 Library
..................

   - gh-93461(1): *note importlib.invalidate_caches(): e0c. now drops
     entries from *note sys.path_importer_cache: 7fb. with a relative
     path as name.  This solves a caching issue when a process changes
     its current working directory.

     ‘FileFinder’ no longer inserts a dot in the path, e.g.
     ‘/egg/./spam’ is now ‘/egg/spam’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/93461


File: python.info,  Node: Core and Builtins<80>,  Next: Library<84>,  Prev: Library<83>,  Up: Python 3 12 0 alpha 1

1.24.33.16 Core and Builtins
............................

   - gh-93621(1): Change order of bytecode instructions emitted for
     *note with: 186. and *note async with: 185. to reduce the number of
     entries in the exception table.

   - gh-93533(2): Reduce the size of the inline cache for ‘LOAD_METHOD’
     by 2 bytes.

   - gh-93444(3): Removed redundant fields from the compiler’s
     basicblock struct: ‘b_nofallthrough’, ‘b_exit’, ‘b_return’.  They
     can be easily calculated from the opcode of the last instruction of
     the block.

   - gh-93429(4): ‘LOAD_METHOD’ instruction has been removed.  It was
     merged back into ‘LOAD_ATTR’.

   - gh-93418(5): Fixed an assert where an f-string has an equal sign
     “=” following an expression, but there’s no trailing brace.  For
     example, f»{i=».

   - gh-93382(6): Cache the result of *note PyCode_GetCode(): 97d.
     function to restore the 'O'(1) lookup of the ‘co_code’ attribute.

   - gh-93359(7): Ensure that custom *note ast: 9. nodes without
     explicit end positions can be compiled.  Patch by Pablo Galindo.

   - gh-93356(8): Code for exception handlers is emitted at the end of
     the code unit’s bytecode.  This avoids one jump when no exception
     is raised.

   - gh-93354(9): Use exponential backoff for specialization counters in
     the interpreter.  Can reduce the number of failed specializations
     significantly and avoid slowdown for those parts of a program that
     are not suitable for specialization.

   - gh-93283(10): Improve error message for invalid syntax of
     conversion character in f-string expressions.

   - gh-93345(11): Fix a crash in substitution of a ‘TypeVar’ in nested
     generic alias after ‘TypeVarTuple’.

   - gh-93223(12): When a bytecode instruction jumps to an unconditional
     jump instruction, the first instruction can often be optimized to
     target the unconditional jump’s target directly.  For tracing
     reasons, this would previously only occur if both instructions have
     the same line number.  This also now occurs if the unconditional
     jump is artificial, i.e., if it has no associated line number.

   - gh-84694(13): The ‘--experimental-isolated-subinterpreters’
     configure option and ‘EXPERIMENTAL_ISOLATED_SUBINTERPRETERS’ macro
     have been removed.

   - gh-91924(14): Fix ‘__lltrace__’ debug feature if the stdout
     encoding is not UTF-8.  Patch by Victor Stinner.

   - gh-93040(15): Wraps unused parameters in ‘Objects/obmalloc.c’ with
     ‘Py_UNUSED’.

   - gh-93143(16): Avoid ‘NULL’ checks for uninitialized local variables
     by determining at compile time which variables must be initialized.

   - gh-93061(17): Backward jumps after ‘async for’ loops are no longer
     given dubious line numbers.

   - gh-93065(18): Fix contextvars HAMT implementation to handle
     iteration over deep trees.

     The bug was discovered and fixed by Eli Libman.  See
     MagicStack/immutables#84(19) for more details.

   - gh-93012(20): Added the new function *note PyType_FromMetaclass():
     773, which generalizes the existing *note
     PyType_FromModuleAndSpec(): 774. using an additional metaclass
     argument.  This is useful for language binding tools, where it can
     be used to intercept type-related operations like subclassing or
     static attribute access by specifying a metaclass with custom
     slots.

     Importantly, *note PyType_FromMetaclass(): 773. is available in the
     Limited API, which provides a path towards migrating more binding
     tools onto the Stable ABI.

   - gh-93021(21): Fix the ‘__text_signature__’ for ‘__get__()’ methods
     implemented in C. Patch by Jelle Zijlstra.

   - gh-89914(22): The operand of the ‘YIELD_VALUE’ instruction is set
     to the stack depth.  This is done to help frame handling on ‘yield’
     and may assist debuggers.

   - gh-92955(23): Fix memory leak in code object’s lines and positions
     iterators as they were not finalized at exit.  Patch by Kumar
     Aditya.

   - gh-92930(24): Fixed a crash in ‘_pickle.c’ from mutating
     collections during ‘__reduce__’ or ‘persistent_id’.

   - gh-90690(25): The PRECALL instruction has been removed.  It offered
     only a small advantage for specialization and is not needed in the
     vast majority of cases.

   - gh-92914(26): Always round the allocated size for lists up to the
     nearest even number.

   - gh-92858(27): Improve error message for some suites with syntax
     error before “:”

   - gh-90473(28): Decrease default recursion limit on WASI to address
     limited call stack size.

   - gh-92804(29): Fix memory leak in ‘memoryview’ iterator as it was
     not finalized at exit.  Patch by Kumar Aditya.

   - gh-92777(30): Specialize ‘LOAD_METHOD’ for objects with lazy
     dictionaries.  Patch by Ken Jin.

   - gh-92658(31): Add support for connecting and binding to Hyper-V
     sockets on Windows Hyper-V hosts and guests.

   - gh-92236(32): Remove spurious «LINE» event when starting a
     generator or coroutine, visible tracing functions implemented in C.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/93621

   (2) https://github.com/python/cpython/issues/93533

   (3) https://github.com/python/cpython/issues/93444

   (4) https://github.com/python/cpython/issues/93429

   (5) https://github.com/python/cpython/issues/93418

   (6) https://github.com/python/cpython/issues/93382

   (7) https://github.com/python/cpython/issues/93359

   (8) https://github.com/python/cpython/issues/93356

   (9) https://github.com/python/cpython/issues/93354

   (10) https://github.com/python/cpython/issues/93283

   (11) https://github.com/python/cpython/issues/93345

   (12) https://github.com/python/cpython/issues/93223

   (13) https://github.com/python/cpython/issues/84694

   (14) https://github.com/python/cpython/issues/91924

   (15) https://github.com/python/cpython/issues/93040

   (16) https://github.com/python/cpython/issues/93143

   (17) https://github.com/python/cpython/issues/93061

   (18) https://github.com/python/cpython/issues/93065

   (19) https://github.com/MagicStack/immutables/issues/84

   (20) https://github.com/python/cpython/issues/93012

   (21) https://github.com/python/cpython/issues/93021

   (22) https://github.com/python/cpython/issues/89914

   (23) https://github.com/python/cpython/issues/92955

   (24) https://github.com/python/cpython/issues/92930

   (25) https://github.com/python/cpython/issues/90690

   (26) https://github.com/python/cpython/issues/92914

   (27) https://github.com/python/cpython/issues/92858

   (28) https://github.com/python/cpython/issues/90473

   (29) https://github.com/python/cpython/issues/92804

   (30) https://github.com/python/cpython/issues/92777

   (31) https://github.com/python/cpython/issues/92658

   (32) https://github.com/python/cpython/issues/92236


File: python.info,  Node: Library<84>,  Next: Core and Builtins<81>,  Prev: Core and Builtins<80>,  Up: Python 3 12 0 alpha 1

1.24.33.17 Library
..................

   - gh-91102(1): ‘_warnings.warn_explicit()’ is ported to Argument
     Clinic.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91102


File: python.info,  Node: Core and Builtins<81>,  Next: Library<85>,  Prev: Library<84>,  Up: Python 3 12 0 alpha 1

1.24.33.18 Core and Builtins
............................

   - gh-92619(1): Make the compiler duplicate an exit block only if none
     of its instructions have a lineno (previously only the first
     instruction in the block was checked, leading to unnecessarily
     duplicated blocks).

   - gh-88750(2): The deprecated debug build only ‘PYTHONTHREADDEBUG’
     environment variable no longer does anything.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/92619

   (2) https://github.com/python/cpython/issues/88750


File: python.info,  Node: Library<85>,  Next: Core and Builtins<82>,  Prev: Core and Builtins<81>,  Up: Python 3 12 0 alpha 1

1.24.33.19 Library
..................

   - gh-92261(1): Fix hang when trying to iterate over a ‘typing.Union’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/92261


File: python.info,  Node: Core and Builtins<82>,  Next: Library<86>,  Prev: Library<85>,  Up: Python 3 12 0 alpha 1

1.24.33.20 Core and Builtins
............................

   - gh-91432(1): Specialized the *note FOR_ITER: 1aaa. opcode using the
     PEP 659 machinery

   - gh-91399(2): Removed duplicate “{0, 0, 0, 0, 0, 0}” entry in
     “Objects/unicodetype_db.h”.

   - gh-91578(3): Updates the error message for abstract class.

   - bpo-47091(4): Improve performance of repetition of *note list: 24d.
     and *note tuple: 614. by using ‘memcpy’ to copy data and performing
     the reference increments in one step.

   - bpo-46142(5): Make ‘--help’ output shorter by moving some info to
     the new ‘--help-env’ and ‘--help-xoptions’ command-line options.
     Also add ‘--help-all’ option to print complete usage.

   - bpo-42316(6): Document some places where an assignment expression
     needs parentheses.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91432

   (2) https://github.com/python/cpython/issues/91399

   (3) https://github.com/python/cpython/issues/91578

   (4) https://bugs.python.org/issue?@action=redirect&bpo=47091

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46142

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42316


File: python.info,  Node: Library<86>,  Next: Documentation<27>,  Prev: Core and Builtins<82>,  Up: Python 3 12 0 alpha 1

1.24.33.21 Library
..................

   - gh-89237(1): Fix hang on Windows in ‘subprocess.wait_closed()’ in
     *note asyncio: b. with *note ProactorEventLoop: 81e.  Patch by
     Kumar Aditya.

   - gh-97928(2): ‘tkinter.Text.count()’ raises now an exception for
     options starting with «-» instead of silently ignoring them.

   - gh-98393(3): The *note os: a5. module no longer accepts bytes-like
     paths, like *note bytearray: 344. and *note memoryview: 165. types:
     only the exact *note bytes: 192. type is accepted for bytes
     strings.  Patch by Victor Stinner.

   - gh-98363(4): Added itertools.batched() to batch data into lists of
     a given length with the last list possibly being shorter than the
     others.

   - gh-98331(5): Update the bundled copies of pip and setuptools to
     versions 22.3 and 65.5.0 respectively.

   - gh-98307(6): A *note createSocket(): 86c. method was added to *note
     SysLogHandler: 86d.

   - gh-96035(7): Fix bug in *note urllib.parse.urlparse(): 362. that
     causes certain port numbers containing whitespace, underscores,
     plus and minus signs, or non-ASCII digits to be incorrectly
     accepted.

   - gh-98257(8): Make *note sys.setprofile(): 1705. and *note
     sys.settrace(): 2e1. functions reentrant.  They can no long fail
     with: ‘RuntimeError("Cannot install a trace function while another
     trace function is being installed")’.  Patch by Victor Stinner.

   - gh-98251(9): Allow *note venv: 117. to pass along ‘PYTHON*’
     variables to ‘ensurepip’ and ‘pip’ when they do not impact path
     resolution

   - gh-94597(10): Deprecated
     ‘asyncio.AbstractEventLoopPolicy.get_child_watcher()’ and
     ‘asyncio.AbstractEventLoopPolicy.set_child_watcher()’ methods to be
     removed in Python 3.14.  Patch by Kumar Aditya.

   - gh-98178(11): On macOS, fix a crash in *note syslog.syslog(): 763.
     in multi-threaded applications.  On macOS, the libc ‘syslog()’
     function is not thread-safe, so *note syslog.syslog(): 763. no
     longer releases the GIL to call it.  Patch by Victor Stinner.

   - gh-44098(12): Release the GIL when creating *note mmap.mmap: 51a.
     objects on Unix.

   - gh-87730(13): Wrap network errors consistently in urllib FTP
     support, so the test suite doesn’t fail when a network is available
     but the public internet is not reachable.

   - gh-94597(14): The child watcher classes ‘MultiLoopChildWatcher’,
     ‘FastChildWatcher’ and ‘SafeChildWatcher’ are deprecated and will
     be removed in Python 3.14.  Patch by Kumar Aditya.

   - gh-98023(15): Change default child watcher to ‘PidfdChildWatcher’
     on Linux systems which supports it.  Patch by Kumar Aditya.

   - gh-90985(16): Earlier in 3.11 we deprecated
     ‘asyncio.Task.cancel("message")’.  We realized we were too harsh,
     and have undeprecated it.

   - gh-65961(17): Do not rely solely on ‘__cached__’ on modules; code
     will also support ‘__spec__.cached’.

   - gh-97646(18): Replace deprecated ‘application/javascript’ with
     ‘text/javascript’ in *note mimetypes: 93.  See RFC 9239(19).  Patch
     by Noam Cohen.

   - gh-97930(20): Apply changes from importlib_resources 5.8 and 5.9:
     ‘Traversable.joinpath’ provides a concrete implementation.
     ‘as_file’ now supports directories of resources.

   - gh-97850(21): Remove deprecated ‘importlib.util.set_loader()’ and
     ‘importlib.util.module_for_loader()’ from *note importlib.util: 81.

   - gh-97837(22): Change deprecate warning message in *note unittest:
     10c. from

     ‘It is deprecated to return a value!=None’

     to

     ‘It is deprecated to return a value that is not None from a test
     case’

   - gh-97825(23): Fixes *note AttributeError: 5f0. when *note
     subprocess.check_output(): 11c4. is used with argument ‘input=None’
     and either of the arguments 'encoding' or 'errors' are used.

   - gh-97008(24): *note NameError: 452. and *note AttributeError: 5f0.
     spelling suggestions provided since gh-82711(25) are now also
     emitted by the pure Python *note traceback: 104. module.  Tests for
     those suggestions now exercise both implementations to ensure they
     are equivalent.  Patch by Carl Friedrich Bolz-Tereick and Łukasz
     Langa.

   - gh-97799(26): ‘dataclass’ now uses *note inspect.get_annotations():
     a16. to examine the annotations on class objects.

   - gh-97781(27): Removed deprecated interfaces in ‘importlib.metadata’
     (entry points accessed as dictionary, implicit dictionary
     construction of sequence of ‘EntryPoint’ objects, mutablility of
     ‘EntryPoints’ result, access of entry point by index).
     ‘entry_points’ now has a simpler, more straightforward API
     (returning ‘EntryPoints’).

   - gh-96827(28): Avoid spurious tracebacks from *note asyncio: b. when
     default executor cleanup is delayed until after the event loop is
     closed (e.g.  as the result of a keyboard interrupt).

   - gh-95534(29): ‘gzip.GzipFile.read()’ reads 10% faster.

   - gh-97592(30): Avoid a crash in the C version of *note
     asyncio.Future.remove_done_callback(): 18f9. when an evil argument
     is passed.

   - gh-97639(31): Remove ‘tokenize.NL’ check from *note tabnanny: e3.

   - gh-97545(32): Make Semaphore run faster.

   - gh-73588(33): Fix generation of the default name of
     ‘tkinter.Checkbutton’.  Previously, checkbuttons in different
     parent widgets could have the same short name and share the same
     state if arguments «name» and «variable» are not specified.  Now
     they are globally unique.

   - gh-96865(34): fix Flag to use boundary CONFORM

     This restores previous Flag behavior of allowing flags with
     non-sequential values to be combined; e.g.

     class Skip(Flag): TWO = 2 EIGHT = 8

     Skip.TWO | Skip.EIGHT -> <Skip.TWO|EIGHT: 10>

   - gh-97005(35): Update bundled libexpat to 2.4.9

   - gh-85760(36): Fix race condition in *note asyncio: b. where *note
     process_exited(): 1b37. called before the *note
     pipe_data_received(): 1b38. leading to inconsistent output.  Patch
     by Kumar Aditya.

   - gh-96704(37): Pass the correct ‘contextvars.Context’ when a
     ‘asyncio’ exception handler is called on behalf of a task or
     callback handle.  This adds a new ‘Task’ method, ‘get_context’, and
     also a new ‘Handle’ method with the same name.  If this method is
     not found on a task object (perhaps because it is a third-party
     library that does not yet provide this method), the context
     prevailing at the time the exception handler is called is used.

   - gh-96819(38): Fixed check in ‘multiprocessing.resource_tracker’
     that guarantees that the length of a write to a pipe is not greater
     than ‘PIPE_BUF’.

   - gh-95865(39): Reduce *note urllib.parse.quote_from_bytes(): 1b39.
     memory use on large values.

     Contributed by Dennis Sweeney.

   - gh-96741(40): Corrected type annotation for dataclass attribute
     ‘pstats.FunctionProfile.ncalls’ to be ‘str’.

   - gh-96734(41): Update *note unicodedata: 10b. database to Unicode
     15.0.0.

   - gh-96735(42): Fix undefined behaviour in *note struct.unpack():
     1842.

   - gh-46412(43): Improve performance of ‘bool(db)’ for large ndb/gdb
     databases.  Previously this would call ‘len(db)’ which would
     iterate over all keys – the answer (empty or not) is known after
     the first key.

   - gh-96652(44): Fix the faulthandler implementation of
     ‘faulthandler.register(signal, chain=True)’ if the ‘sigaction()’
     function is not available: don’t call the previous signal handler
     if it’s NULL. Patch by Victor Stinner.

   - gh-68163(45): Correct conversion of *note numbers.Rational: 14c6.’s
     to *note float: 196.

   - gh-96538(46): Speed up ‘bisect.bisect()’ functions by taking
     advantage of type-stability.

   - gh-96465(47): Fraction hashes are now cached.

   - gh-96079(48): In *note typing: 10a, fix missing field ‘name’ and
     incorrect ‘__module__’ in _AnnotatedAlias.

   - gh-96415(49): Remove ‘types._cell_factory’ from module namespace.

   - gh-95987(50): Fix ‘repr’ of ‘Any’ subclasses.

   - gh-96388(51): Work around missing socket functions in *note socket:
     fa3.’s ‘__repr__’.

   - gh-96385(52): Fix ‘TypeVarTuple.__typing_prepare_subst__’.
     ‘TypeError’ was not raised when using more than one ‘TypeVarTuple’,
     like ‘[*T, *V]’ in type alias substitutions.

   - gh-96142(53): Add ‘match_args’, ‘kw_only’, ‘slots’, and
     ‘weakref_slot’ to ‘_DataclassParams’.

   - gh-96073(54): In *note inspect: 82, fix overeager replacement of
     «‘typing.’» in formatting annotations.

   - gh-89258(55): Added a *note getChildren(): 1b3a. method to *note
     logging.Logger: d48, to get the immediate child loggers of a
     logger.

   - gh-96346(56): Use double caching for compiled RE patterns.

   - gh-96349(57): Fixed a minor performance regression in
     ‘threading.Event.__init__()’

   - gh-90467(58): Fix ‘asyncio.streams.StreamReaderProtocol’ to keep a
     strong reference to the created task, so that it’s not garbage
     collected

   - gh-96172(59): Fix a bug in ‘unicodedata’: ‘east_asian_width’ used
     to return the wrong value for unassigned characters; and for yet
     unassigned, but reserved characters.

   - gh-96159(60): Fix a performance regression in logging
     TimedRotatingFileHandler.  Only check for special files when the
     rollover time has passed.

   - gh-96175(61): Fix unused ‘localName’ parameter in the ‘Attr’ class
     in *note xml.dom.minidom: 128.

   - gh-96145(62): Add AttrDict to JSON module for use with object_hook.

   - gh-96052(63): Fix handling compiler warnings (SyntaxWarning and
     DeprecationWarning) in *note codeop.compile_command(): 1b3b. when
     checking for incomplete input.  Previously it emitted warnings and
     raised a SyntaxError.  Now it always returns ‘None’ for incomplete
     input without emitting any warnings.

   - gh-96125(64): Fix incorrect condition that causes
     ‘sys.thread_info.name’ to be wrong on pthread platforms.

   - gh-96019(65): Fix a bug in the ‘makeunicodedata.py’ script leading
     to about 13 KiB of space saving in the ‘unicodedata’ module,
     specifically the character decomposition data.

   - gh-95463(66): Remove an incompatible change from bpo-28080(67) that
     caused a regression that ignored the utf8 in ‘ZipInfo.flag_bits’.
     Patch by Pablo Galindo.

   - gh-69142(68): Add ‘%:z’ strftime format code (generates tzoffset
     with colons as separator), see *note strftime() and strptime()
     Behavior: 1b3c.

   - gh-95899(69): Fix *note asyncio.Runner: 2f5. to call *note
     asyncio.set_event_loop(): 1b3d. only once to avoid calling
     ‘attach_loop()’ multiple times on child watchers.  Patch by Kumar
     Aditya.

   - gh-95736(70): Fix *note unittest.IsolatedAsyncioTestCase: 361. to
     set event loop before calling setup functions.  Patch by Kumar
     Aditya.

   - gh-95865(71): Speed up *note urllib.parse.quote_from_bytes(): 1b39.
     by replacing a list comprehension with ‘map()’.

   - gh-95861(72): Add support for computing Spearman’s correlation
     coefficient to the existing statistics.correlation() function.

   - gh-95804(73): Fix ‘logging’ shutdown handler so it respects
     ‘MemoryHandler.flushOnClose’.

   - gh-95704(74): When a task catches *note asyncio.CancelledError:
     4d5. and raises some other error, the other error should generally
     not silently be suppressed.

   - gh-95149(75): The *note HTTPStatus: afe. enum offers a couple of
     properties to indicate the HTTP status category e.g.
     ‘HTTPStatus.OK.is_success’.

   - gh-95609(76): Update bundled pip to 22.2.2.

   - gh-95289(77): Fix *note asyncio.TaskGroup: 4d2. to propagate
     exception when *note asyncio.CancelledError: 4d5. was replaced with
     another exception by a context manager.  Patch by Kumar Aditya and
     Guido van Rossum.

   - gh-94909(78): Fix incorrect joining of relative Windows paths with
     drives in *note pathlib.PurePath: 6ce. initializer.

   - gh-95385(79): Faster ‘json.dumps()’ when sorting of keys is not
     requested (default).

   - gh-83901(80): Improve *note Signature.bind: 187a. error message for
     missing keyword-only arguments.

   - gh-95339(81): Update bundled pip to 22.2.1.

   - gh-95045(82): Fix GC crash when deallocating ‘_lsprof.Profiler’ by
     untracking it before calling any callbacks.  Patch by Kumar Aditya.

   - gh-95231(83): Fail gracefully if *note EPERM: 1b3e. or *note
     ENOSYS: 1b3f. is raised when loading ‘crypt’ methods.  This may
     happen when trying to load ‘MD5’ on a Linux kernel with FIPS
     (Federal Information Processing Standard) enabled.

   - gh-95097(84): Fix *note asyncio.run(): 2f3. for *note asyncio.Task:
     1c7. implementations without *note uncancel(): 4d7. method.  Patch
     by Kumar Aditya.

   - gh-95087(85): Fix IndexError in parsing invalid date in the *note
     email: 3f. module.

   - gh-95199(86): Upgrade bundled setuptools to 63.2.0.

   - gh-95194(87): Upgrade bundled pip to 22.2.

   - gh-93899(88): Fix check for existence of *note os.EFD_CLOEXEC:
     1b40, *note os.EFD_NONBLOCK: 1b41. and *note os.EFD_SEMAPHORE:
     1b42. flags on older kernel versions where these flags are not
     present.  Patch by Kumar Aditya.

   - gh-95166(89): Fix *note concurrent.futures.Executor.map(): 1dc. to
     cancel the currently waiting on future on an error - e.g.
     TimeoutError or KeyboardInterrupt.

   - gh-95132(90): Fix a *note sqlite3: d4. regression where ‘*args’ and
     ‘**kwds’ were incorrectly relayed from *note connect(): 5a6. to the
     *note Connection: 54e. factory.  The regression was introduced in
     3.11a1 with PR 24421 (gh-85128(91)).  Patch by Erlend E. Aasland.

   - gh-93157(92): Fix *note fileinput: 5f. module didn’t support
     ‘errors’ option when ‘inplace’ is true.

   - gh-91212(93): Fixed flickering of the turtle window when the tracer
     is turned off.  Patch by Shin-myoung-serp.

   - gh-95077(94): Add deprecation warning for enum ‘member.member’
     access (e.g.  ‘Color.RED.BLUE’).  Remove ‘EnumMeta.__getattr__’.

   - gh-95109(95): Ensure that timeouts scheduled with *note
     asyncio.Timeout: 1a28. that have already expired are delivered
     promptly.

   - gh-95105(96): ‘wsgiref.types.InputStream.__iter__()’ should return
     ‘Iterator[bytes]’, not ‘Iterable[bytes]’.  Patch by Shantanu Jain.

   - gh-95066(97): Replaced assert with exception in *note ast.parse():
     1c2, when ‘feature_version’ has an invalid major version.  Patch by
     Shantanu Jain.

   - gh-77617(98): Add *note sqlite3: d4. *note command-line interface:
     674.  Patch by Erlend Aasland.

   - gh-95005(99): Replace _PyAccu with _PyUnicodeWriter in JSON encoder
     and StringIO and remove the _PyAccu implementation.

   - gh-90085(100): Remove ‘-c/--clock’ and ‘-t/--time’ CLI options of
     *note timeit: f5.  The options had been deprecated since Python 3.3
     and the functionality was removed in Python 3.7.  Patch by Shantanu
     Jain.

   - gh-94857(101): Fix refleak in ‘_io.TextIOWrapper.reconfigure’.
     Patch by Kumar Aditya.

   - gh-94821(102): Fix binding of unix socket to empty address on Linux
     to use an available address from the abstract namespace, instead of
     «0».

   - gh-94736(103): Fix crash when deallocating an instance of a
     subclass of ‘_multiprocessing.SemLock’.  Patch by Kumar Aditya.

   - gh-81620(104): Add random.binomialvariate().

   - gh-74116(105): Allow *note asyncio.StreamWriter.drain(): 1b11. to
     be awaited concurrently by multiple tasks.  Patch by Kumar Aditya.

   - gh-87822(106): When called with ‘capture_locals=True’, the *note
     traceback: 104. module functions swallow exceptions raised from
     calls to ‘repr()’ on local variables of frames.  This is in order
     to prioritize the original exception over rendering errors.  An
     indication of the failure is printed in place of the missing value.
     (Patch by Simon-Martin Schroeder).

   - gh-88050(107): Fix *note asyncio: b. subprocess transport to kill
     process cleanly when process is blocked and avoid ‘RuntimeError’
     when loop is closed.  Patch by Kumar Aditya.

   - gh-94637(108): ‘SSLContext.set_default_verify_paths()’ now releases
     the GIL around ‘SSL_CTX_set_default_verify_paths’ call.  The
     function call performs I/O and CPU intensive work.

   - gh-94309(109): Deprecate aliases *note typing.Hashable: 718. and
     *note typing.Sized: 719.

   - gh-92546(110): An undocumented ‘python -m pprint’ benchmark is
     moved into ‘pprint’ suite of pyperformance.  Patch by Oleg Iarygin.

   - gh-94607(111): Fix subclassing complex generics with type variables
     in *note typing: 10a.  Previously an error message saying ‘Some
     type variables ... are not listed in Generic[...]’ was shown.
     *note typing: 10a. no longer populates ‘__parameters__’ with the
     ‘__parameters__’ of a Python class.

   - gh-94619(112): Remove the long-deprecated ‘module_repr()’ from
     *note importlib: 7b.

   - gh-93910(113): The ability to access the other values of an enum on
     an enum (e.g.  ‘Color.RED.BLUE’) has been restored in order to fix
     a performance regression.

   - gh-93896(114): Fix *note asyncio.run(): 2f3. and *note
     unittest.IsolatedAsyncioTestCase: 361. to always the set event loop
     as it was done in Python 3.10 and earlier.  Patch by Kumar Aditya.

   - gh-94343(115): Allow setting the attributes of ‘reprlib.Repr’
     during object initialization

   - gh-94382(116): Port static types of ‘_multiprocessing’ module to
     heap types.  Patch by Kumar Aditya.

   - gh-78724(117): Fix crash in *note struct.Struct: 175f. when it was
     not completely initialized by initializing it in *note __new__():
     7a1.  Patch by Kumar Aditya.

   - gh-94510(118): Re-entrant calls to *note sys.setprofile(): 1705.
     and *note sys.settrace(): 2e1. now raise *note RuntimeError: 244.
     Patch by Pablo Galindo.

   - gh-92336(119): Fix bug where *note linecache.getline(): 240. fails
     on bad files with *note UnicodeDecodeError: c0a. or *note
     SyntaxError: 18e.  It now returns an empty string as per the
     documentation.

   - gh-94398(120): Once a *note asyncio.TaskGroup: 4d2. has started
     shutting down (i.e., at least one task has failed and the task
     group has started cancelling the remaining tasks), it should not be
     possible to add new tasks to the task group.

   - gh-94383(121): ‘xml.etree’: Remove the ‘ElementTree.Element.copy()’
     method of the pure Python implementation, deprecated in Python
     3.10, use the *note copy.copy(): 758. function instead.  The C
     implementation of ‘xml.etree’ has no ‘copy()’ method, only a
     ‘__copy__()’ method.  Patch by Victor Stinner.

   - gh-94379(122): *note zipimport: 138.: Remove ‘find_loader()’ and
     ‘find_module()’ methods, deprecated in Python 3.10: use the
     ‘find_spec()’ method instead.  See PEP 451(123) for the rationale.
     Patch by Victor Stinner.

   - gh-94352(124): *note shlex.split(): 75f.: Passing ‘None’ for 's'
     argument now raises an exception, rather than reading *note
     sys.stdin: 760.  The feature was deprecated in Python 3.9.  Patch
     by Victor Stinner.

   - gh-94318(125): Strip trailing spaces in *note pydoc: ba. text
     output.

   - gh-89988(126): Fix memory leak in *note pickle.Pickler: c15. when
     looking up ‘dispatch_table’.  Patch by Kumar Aditya.

   - gh-90016(127): Deprecate *note sqlite3: d4. *note default adapters
     and converters: 715.  Patch by Erlend E. Aasland.

   - gh-94254(128): Fixed types of *note struct: db. module to be
     immutable.  Patch by Kumar Aditya.

   - gh-93259(129): Now raise ‘ValueError’ when ‘None’ or an empty
     string are passed to ‘Distribution.from_name’ (and other callers).

   - gh-74696(130): *note shutil.make_archive(): 6db. now passes the
     'root_dir' argument to custom archivers which support it.

   - gh-94216(131): The *note dis: 3c. module now has the opcodes for
     pseudo instructions (those which are used by the compiler during
     code generation but then removed or replaced by real opcodes before
     the final bytecode is emitted).

   - gh-93096(132): Removed undocumented ‘python -m codecs’.  Use
     ‘python -m unittest test.test_codecs.EncodedFileTest’ instead.

   - gh-94207(133): Made ‘_struct.Struct’ GC-tracked in order to fix a
     reference leak in the ‘_struct’ module.

   - gh-93096(134): Removed undocumented ‘-t’ argument of ‘python -m
     base64’.  Use ‘python -m unittest
     test.test_base64.LegacyBase64TestCase.test_encodebytes’ instead.

   - gh-94226(135): Remove the ‘locale.format()’ function, deprecated in
     Python 3.7: use *note locale.format_string(): 743. instead.  Patch
     by Victor Stinner.

   - gh-94199(136): Remove the ‘ssl.match_hostname()’ function.  The
     ‘ssl.match_hostname()’ was deprecated in Python 3.7.  OpenSSL
     performs hostname matching since Python 3.7, Python no longer uses
     the ‘ssl.match_hostname()’ function.  Patch by Victor Stinner.

   - gh-94214(137): Document the ‘context’ object used in the
     ‘venv.EnvBuilder’ class, and add the new environment’s library path
     to it.

   - gh-94199(138): Remove the ‘ssl.wrap_socket()’ function, deprecated
     in Python 3.7: instead, create a *note ssl.SSLContext: 357. object
     and call its *note ssl.SSLContext.wrap_socket: 749. method.  Any
     package that still uses ‘ssl.wrap_socket()’ is broken and insecure.
     The function neither sends a SNI TLS extension nor validates server
     hostname.  Code is subject to CWE 295(139) Improper Certificate
     Validation.  Patch by Victor Stinner.

   - gh-94199(140): Remove the ‘ssl.RAND_pseudo_bytes()’ function,
     deprecated in Python 3.6: use *note os.urandom(): 747. or *note
     ssl.RAND_bytes(): 748. instead.  Patch by Victor Stinner.

   - gh-94199(141): *note hashlib: 6c.: Remove the pure Python
     implementation of *note hashlib.pbkdf2_hmac(): 734, deprecated in
     Python 3.10.  Python 3.10 and newer requires OpenSSL 1.1.1 ( PEP
     644(142)): this OpenSSL version provides a C implementation of
     *note pbkdf2_hmac(): 734. which is faster.  Patch by Victor
     Stinner.

   - gh-94196(143): *note gzip: 6b.: Remove the ‘filename’ attribute of
     *note gzip.GzipFile: 65c, deprecated since Python 2.6, use the
     *note name: 732. attribute instead.  In write mode, the ‘filename’
     attribute added ‘'.gz'’ file extension if it was not present.
     Patch by Victor Stinner.

   - gh-94182(144): run the ‘asyncio.PidfdChildWatcher’ on the running
     loop, this allows event loops to run subprocesses when there is no
     default event loop running on the main thread

   - gh-94169(145): Remove ‘io.OpenWrapper’ and ‘_pyio.OpenWrapper’,
     deprecated in Python 3.10: just use *note open(): 316. instead.
     The *note open(): 316. (*note io.open(): 741.) function is a
     built-in function.  Since Python 3.10, ‘_pyio.open()’ is also a
     static method.  Patch by Victor Stinner.

   - gh-91742(146): Fix *note pdb: aa. crash after jump caused by a null
     pointer dereference.  Patch by Kumar Aditya.

   - gh-94101(147): Manual instantiation of *note ssl.SSLSession: edb.
     objects is no longer allowed as it lead to misconfigured instances
     that crashed the interpreter when attributes where accessed on
     them.

   - gh-84753(148): *note inspect.iscoroutinefunction(): 30d, *note
     inspect.isgeneratorfunction(): 1b43, and *note
     inspect.isasyncgenfunction(): 1b44. now properly return ‘True’ for
     duck-typed function-like objects like instances of *note
     unittest.mock.AsyncMock: c40.

     This makes *note inspect.iscoroutinefunction(): 30d. consistent
     with the behavior of ‘asyncio.iscoroutinefunction()’.  Patch by
     Mehdi ABAAKOUK.

   - gh-94028(149): Fix a regression in the *note sqlite3: d4. where
     statement objects were not properly cleared and reset after use in
     cursor iters.  The regression was introduced by PR 27884 in Python
     3.11a1.  Patch by Erlend E. Aasland.

   - gh-93973(150): Add keyword argument ‘all_errors’ to
     ‘asyncio.create_connection’ so that multiple connection errors can
     be raised as an ‘ExceptionGroup’.

   - gh-93963(151): Officially deprecate from ‘importlib.abc’ classes
     moved to ‘importlib.resources.abc’.

   - gh-93858(152): Prevent error when activating venv in nested fish
     instances.

   - gh-93820(153): Pickle *note enum.Flag: 836. by name.

   - gh-93847(154): Fix repr of enum of generic aliases.

   - gh-91404(155): Revert the *note re: be. memory leak when a match is
     terminated by a signal or memory allocation failure as the
     implemented fix caused a major performance regression.

   - gh-83499(156): Fix double closing of file description in *note
     tempfile: e6.

   - gh-93820(157): Fixed a regression when *note copy.copy(): 758.-ing
     *note enum.Flag: 836. with multiple flag members.

   - gh-79512(158): Fixed names and ‘__module__’ value of *note weakref:
     11a. classes *note ReferenceType: 1b45, *note ProxyType: 1b46,
     *note CallableProxyType: 1b47.  It makes them pickleable.

   - gh-91389(159): Fix an issue where *note dis: 3c. utilities could
     report missing or incorrect position information in the presence of
     ‘CACHE’ entries.

   - gh-93626(160): Set ‘__future__.annotations’ to have a ‘None’
     mandatoryRelease to indicate that it is currently “TBD”.

   - gh-90473(161): Emscripten and WASI have no home directory and
     cannot provide PEP 370(162) user site directory.

   - gh-90494(163): *note copy.copy(): 758. and *note copy.deepcopy():
     d67. now always raise a TypeError if ‘__reduce__()’ returns a tuple
     with length 6 instead of silently ignore the 6th item or produce
     incorrect result.

   - gh-90549(164): Fix a multiprocessing bug where a global named
     resource (such as a semaphore) could leak when a child process is
     spawned (as opposed to forked).

   - gh-93521(165): Fixed a case where dataclasses would try to add
     ‘__weakref__’ into the ‘__slots__’ for a dataclass that specified
     ‘weakref_slot=True’ when it was already defined in one of its
     bases.  This resulted in a ‘TypeError’ upon the new class being
     created.

   - gh-79579(166): *note sqlite3: d4. now correctly detects DML queries
     with leading comments.  Patch by Erlend E. Aasland.

   - gh-93421(167): Update *note sqlite3.Cursor.rowcount: 1b48. when a
     DML statement has run to completion.  This fixes the row count for
     SQL queries like ‘UPDATE ... RETURNING’.  Patch by Erlend E.
     Aasland.

   - gh-93475(168): Expose ‘FICLONE’ and ‘FICLONERANGE’ constants in
     *note fcntl: 5d.  Patch by Illia Volochii.

   - gh-93370(169): Deprecate ‘version’ and ‘version_info’.

   - gh-91810(170): Suppress writing an XML declaration in open files in
     ‘ElementTree.write()’ with ‘encoding='unicode'’ and
     ‘xml_declaration=None’.

   - gh-91162(171): Support splitting of unpacked arbitrary-length tuple
     over ‘TypeVar’ and ‘TypeVarTuple’ parameters.  For example:

        * ‘A[T, *Ts][*tuple[int, ...]]’ -> ‘A[int, *tuple[int, ...]]’

        * ‘A[*Ts, T][*tuple[int, ...]]’ -> ‘A[*tuple[int, ...], int]’

   - gh-93353(172): Fix the *note importlib.resources.as_file(): 6b6.
     context manager to remove the temporary file if destroyed late
     during Python finalization: keep a local reference to the *note
     os.remove(): 12f8. function.  Patch by Victor Stinner.

   - gh-83658(173): Make ‘multiprocessing.Pool’ raise an exception if
     ‘maxtasksperchild’ is not ‘None’ or a positive int.

   - gh-93312(174): Add *note os.PIDFD_NONBLOCK: 6c3. flag to open a
     file descriptor for a process with *note os.pidfd_open(): 6a5. in
     non-blocking mode.  Patch by Kumar Aditya.

   - gh-88123(175): Implement ‘Enum.__contains__’ that returns ‘True’ or
     ‘False’ to replace the deprecated behaviour that would sometimes
     raise a *note TypeError: 198.

   - gh-93297(176): Make asyncio task groups prevent child tasks from
     being GCed

   - gh-85308(177): Changed *note argparse.ArgumentParser: 1bd. to use
     *note filesystem encoding and error handler: 75e. instead of
     default text encoding to read arguments from file (e.g.
     ‘fromfile_prefix_chars’ option).  This change affects Windows;
     argument file should be encoded with UTF-8 instead of ANSI
     Codepage.

   - gh-93156(178): Accessing the *note pathlib.PurePath.parents: a23.
     sequence of an absolute path using negative index values produced
     incorrect results.

   - gh-93162(179): Add the ability for *note
     logging.config.dictConfig(): 13b8. to usefully configure *note
     QueueHandler: 1b49. and *note QueueListener: 242. as a pair, and
     add *note logging.getHandlerByName(): 1b4a. and *note
     logging.getHandlerNames(): 1a56. APIs to allow access to handlers
     by name.

   - gh-93243(180): The ‘smtpd’ module was removed per the schedule in
     PEP 594(181).

   - gh-92886(182): Replace ‘assert’ statements with ‘raise
     AssertionError()’ in ‘BaseHandler’ so that the tested behaviour is
     maintained running with optimizations ‘(-O)’.

   - gh-90155(183): Fix broken *note asyncio.Semaphore: c6a. when
     acquire is cancelled.

   - gh-90817(184): The ‘locale.resetlocale()’ function is deprecated
     and will be removed in Python 3.13.  Use
     ‘locale.setlocale(locale.LC_ALL, "")’ instead.  Patch by Victor
     Stinner.

   - gh-91513(185): Added ‘taskName’ attribute to *note logging: 8b.
     module for use with *note asyncio: b. tasks.

   - gh-74696(186): *note shutil.make_archive(): 6db. no longer
     temporarily changes the current working directory during creation
     of standard ‘.zip’ or tar archives.

   - gh-92728(187): The ‘re.template()’ function and the corresponding
     ‘re.TEMPLATE’ and ‘re.T’ flags are restored after they were removed
     in 3.11.0b1, but they are now deprecated, so they might be removed
     from Python 3.13.

   - gh-93033(188): Search in some strings (platform dependent i.e
     [U+0xFFFF, U+0x0100] on Windows or [U+0xFFFFFFFF, U+0x00010000] on
     Linux 64-bit) are now up to 10 times faster.

   - gh-89973(189): Fix ‘re.error’ raised in *note fnmatch: 60. if the
     pattern contains a character range with upper bound lower than
     lower bound (e.g.  ‘[c-a]’).  Now such ranges are interpreted as
     empty ranges.

   - gh-93044(190): No longer convert the database argument of *note
     sqlite3.connect(): 5a6. to bytes before passing it to the factory.

   - gh-93010(191): In a very special case, the email package tried to
     append the nonexistent ‘InvalidHeaderError’ to the defect list.  It
     should have been ‘InvalidHeaderDefect’.

   - gh-92986(192): Fix *note ast.unparse(): ae4. when
     ‘ImportFrom.level’ is ‘None’

   - gh-92932(193): Now *note dis(): 205. and *note get_instructions():
     4ed. handle operand values for instructions prefixed by
     ‘EXTENDED_ARG_QUICK’.  Patch by Sam Gross and Donghee Na.

   - gh-92675(194): Fix ‘venv.ensure_directories()’ to accept *note
     pathlib.Path: 266. arguments in addition to *note str: 169. paths.
     Patch by David Foster.

   - gh-87901(195): Removed the ‘encoding’ argument from *note
     os.popen(): 31a. that was added in 3.11b1.

   - gh-91922(196): Fix function ‘sqlite.connect()’ and the
     ‘sqlite.Connection’ constructor on non-UTF-8 locales.  Also, they
     now support bytes paths non-decodable with the current FS encoding.

   - gh-92869(197): Added *note c_time_t: 1b4b. to *note ctypes: 2e,
     which has the same size as the ‘time_t’ type in C.

   - gh-92839(198): Fixed crash resulting from calling bisect.insort()
     or bisect.insort_left() with the key argument not equal to ‘None’.

   - gh-90473(199): *note subprocess: dc. now fails early on Emscripten
     and WASI platforms to work around missing *note os.pipe(): 1b4c. on
     WASI.

   - gh-89325(200): Removed many old deprecated *note unittest: 10c.
     features: *note TestCase: 2b3. method aliases, undocumented and
     broken *note TestCase: 2b3. method ‘assertDictContainsSubset’,
     undocumented *note TestLoader.loadTestsFromModule: 594. parameter
     'use_load_tests', and an underscored alias of the *note
     TextTestResult: 755. class.

   - gh-92734(201): Allow multi-element reprs emitted by *note reprlib:
     c0. to be pretty-printed using configurable indentation.

   - gh-92671(202): Fixed *note ast.unparse(): ae4. for empty tuples in
     the assignment target context.

   - gh-91581(203): *note utcfromtimestamp(): 352. no longer attempts to
     resolve ‘fold’ in the pure Python implementation, since the fold is
     never 1 in UTC. In addition to being slightly faster in the common
     case, this also prevents some errors when the timestamp is close to
     *note datetime.min: 1b4d.  Patch by Paul Ganssle.

   - gh-86388(204): Removed randrange() functionality deprecated since
     Python 3.10.  Formerly, randrange(10.0) losslessly converted to
     randrange(10).  Now, it raises a TypeError.  Also, the exception
     raised for non-integral values such as randrange(10.5) or
     randrange(“10”) has been changed from ValueError to TypeError.

   - gh-90385(205): Add *note pathlib.Path.walk(): 6d0. as an
     alternative to *note os.walk(): 6d1.

   - gh-92550(206): Fix *note pathlib.Path.rglob(): 539. for empty
     pattern.

   - gh-92591(207): Allow *note logging: 8b. filters to return a *note
     logging.LogRecord: 11e8. instance so that filters attached to *note
     logging.Handler: 169d.s can enrich records without side effects on
     other handlers.

   - gh-92445(208): Fix a bug in *note argparse: 7. where ‘nargs="*"’
     would raise an error instead of returning an empty list when 0
     arguments were supplied if choice was also defined in
     ‘parser.add_argument’.

   - gh-92547(209): Remove undocumented *note sqlite3: d4. features
     deprecated in Python 3.10:

        * ‘sqlite3.enable_shared_cache()’

        * ‘sqlite3.OptimizedUnicode’

     Patch by Erlend E. Aasland.

   - gh-92530(210): Fix an issue that occurred after interrupting *note
     threading.Condition.notify(): 1b4e.

   - gh-92531(211): The statistics.median_grouped() function now always
     return a float.  Formerly, it did not convert the input type when
     for sequences of length one.

   - gh-84131(212): The *note pathlib.Path: 266. deprecated method
     ‘link_to’ has been removed.  Use 3.10’s *note hardlink_to(): a24.
     method instead as its semantics are consistent with that of *note
     symlink_to(): a25.

   - gh-89336(213): Removed *note configparser: 26. module APIs: the
     ‘SafeConfigParser’ class alias, the ‘ParsingError.filename’
     property and parameter, and the ‘ConfigParser.readfp’ method, all
     of which were deprecated since Python 3.2.

   - gh-92391(214): Add *note __class_getitem__(): 944. to *note
     csv.DictReader: bda. and *note csv.DictWriter: 1406, allowing them
     to be parameterized at runtime.  Patch by Marc Mueller.

   - gh-91968(215): Add ‘SO_RTABLE’ and ‘SO_USER_COOKIE’ constants to
     *note socket: d1.

   - gh-91810(216): *note ElementTree: b49. method *note write(): c8e.
     and function *note tostring(): 11f7. now use the text file’s
     encoding («UTF-8» if not available) instead of locale encoding in
     XML declaration when ‘encoding="unicode"’ is specified.

   - gh-81790(217): *note os.path.splitdrive(): df1. now understands DOS
     device paths with UNC links (beginning ‘\\?\UNC\’).  Contributed by
     Barney Gale.

   - gh-91760(218): Apply more strict rules for numerical group
     references and group names in regular expressions.  Only sequence
     of ASCII digits is now accepted as a numerical reference.  The
     group name in bytes patterns and replacement strings can now only
     contain ASCII letters and digits and underscore.

   - gh-90622(219): Worker processes for *note
     concurrent.futures.ProcessPoolExecutor: 1d6. are no longer spawned
     on demand (a feature added in 3.9) when the multiprocessing context
     start method is ‘"fork"’ as that can lead to deadlocks in the child
     processes due to a fork happening while threads are running.

   - gh-91577(220): Move imports in ‘SharedMemory’ methods to module
     level so that they can be executed late in python finalization.

   - gh-91581(221): Remove an unhandled error case in the C
     implementation of calls to *note datetime.fromtimestamp: 713. with
     no time zone (i.e.  getting a local time from an epoch timestamp).
     This should have no user-facing effect other than giving a possibly
     more accurate error message when called with timestamps that fall
     on 10000-01-01 in the local time.  Patch by Paul Ganssle.

   - gh-91539(222): Improve performance of
     ‘urllib.request.getproxies_environment’ when there are many
     environment variables

   - gh-91524(223): Speed up the regular expression substitution
     (functions *note re.sub(): 5a3. and *note re.subn(): 5a4. and
     corresponding *note re.Pattern: 1b4f. methods) for replacement
     strings containing group references by 2–3 times.

   - gh-91447(224): Fix findtext in the xml module to only give an empty
     string when the text attribute is set to ‘None’.

   - gh-91456(225): Deprecate current default auto() behavior: In 3.13
     the default will be for for auto() to always return the largest
     member value incremented by 1, and to raise if incompatible value
     types are used.

   - bpo-47231(226): Fixed an issue with inconsistent trailing slashes
     in tarfile longname directories.

   - bpo-39064(227): *note zipfile.ZipFile: 8d4. now raises *note
     zipfile.BadZipFile: 1b50. instead of ‘ValueError’ when reading a
     corrupt zip file in which the central directory offset is negative.

   - bpo-41287(228): Fix handling of the ‘doc’ argument in subclasses of
     *note property(): 4b4.

   - gh-90005(229): *note ctypes: 2e. dependency ‘libffi’ is now
     detected with ‘pkg-config’.

   - bpo-32547(230): The constructors for *note DictWriter: 1406. and
     *note DictReader: bda. now coerce the ‘fieldnames’ argument to a
     *note list: 24d. if it is an iterator.

   - bpo-35540(231): Fix *note dataclasses.asdict(): 1a7d. crash when
     *note collections.defaultdict: 13c4. is present in the attributes.

   - bpo-47063(232): Add an index_pages parameter to support using
     non-default index page names.

   - bpo-47025(233): Drop support for *note bytes: 192. on *note
     sys.path: 3e4.

   - bpo-46951(234): Order the contents of zipapp archives, to make
     builds more reproducible.

   - bpo-42777(235): Implement *note pathlib.Path.is_mount(): c0e. for
     Windows paths.

   - bpo-46755(236): In ‘QueueHandler’, clear ‘stack_info’ from
     ‘LogRecord’ to prevent stack trace from being written twice.

   - bpo-45393(237): Fix the formatting for ‘await x’ and ‘not x’ in the
     operator precedence table when using the *note help(): ad6. system.

   - bpo-46642(238): Improve error message when trying to subclass an
     instance of *note typing.TypeVar: 487, *note typing.ParamSpec: 488,
     *note typing.TypeVarTuple: 489, etc.  Based on patch by Gregory
     Beauregard.

   - bpo-46364(239): Restrict use of sockets instead of pipes for stdin
     of subprocesses created by *note asyncio: b. to AIX platform only.

   - bpo-28249(240): Set *note doctest.DocTest.lineno: 17af. to ‘None’
     when an object does not have *note __doc__: b23.

   - bpo-46197(241): Fix *note ensurepip: 59. environment isolation for
     subprocess running ‘pip’.

   - bpo-45924(242): Fix *note asyncio: b. incorrect traceback when
     future’s exception is raised multiple times.  Patch by Kumar
     Aditya.

   - bpo-45046(243): Add support of context managers in *note unittest:
     10c.: methods *note enterContext(): 8c9. and *note
     enterClassContext(): 8ca. of class *note TestCase: 2b3, method
     *note enterAsyncContext(): 8cb. of class *note
     IsolatedAsyncioTestCase: 361. and function *note
     unittest.enterModuleContext(): 8cc.

   - bpo-44173(244): Enable fast seeking of uncompressed unencrypted
     ‘zipfile.ZipExtFile’

   - bpo-42627(245): Fix incorrect parsing of Windows registry proxy
     settings

   - bpo-42047(246): Add *note threading.get_native_id(): c34. support
     for DragonFly BSD. Patch by David Carlier.

   - bpo-14243(247): The *note tempfile.NamedTemporaryFile: 6ee.
     function has a new optional parameter 'delete_on_close'

   - bpo-41246(248): Give the same callback function for when the
     overlapped operation is done to the functions ‘recv’, ‘recv_into’,
     ‘recvfrom’, ‘sendto’, ‘send’ and ‘sendfile’ inside ‘IocpProactor’.

   - bpo-39264(249): Fixed ‘collections.UserDict.get()’ to not call
     *note __missing__(): 13c5. when a value is not found.  This matches
     the behavior of *note dict: 183.  Patch by Bar Harel.

   - bpo-38693(250): *note importlib: 7b. now uses f-strings internally
     instead of ‘str.format’.

   - bpo-38267(251): Add 'timeout' parameter to *note
     asyncio.loop.shutdown_default_executor(): ae6.  The default value
     is ‘None’, which means the executor will be given an unlimited
     amount of time.  When called from *note asyncio.Runner: 2f5. or
     *note asyncio.run(): 2f3, the default timeout is 5 minutes.

   - bpo-34828(252): *note sqlite3.Connection.iterdump(): 550. now
     handles databases that use ‘AUTOINCREMENT’ in one or more tables.

   - bpo-32990(253): Support reading wave files with the
     ‘WAVE_FORMAT_EXTENSIBLE’ format in the *note wave: 119. module.

   - bpo-26253(254): Allow adjustable compression level for tarfile
     streams in *note tarfile.open(): 1079.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89237

   (2) https://github.com/python/cpython/issues/97928

   (3) https://github.com/python/cpython/issues/98393

   (4) https://github.com/python/cpython/issues/98363

   (5) https://github.com/python/cpython/issues/98331

   (6) https://github.com/python/cpython/issues/98307

   (7) https://github.com/python/cpython/issues/96035

   (8) https://github.com/python/cpython/issues/98257

   (9) https://github.com/python/cpython/issues/98251

   (10) https://github.com/python/cpython/issues/94597

   (11) https://github.com/python/cpython/issues/98178

   (12) https://github.com/python/cpython/issues/44098

   (13) https://github.com/python/cpython/issues/87730

   (14) https://github.com/python/cpython/issues/94597

   (15) https://github.com/python/cpython/issues/98023

   (16) https://github.com/python/cpython/issues/90985

   (17) https://github.com/python/cpython/issues/65961

   (18) https://github.com/python/cpython/issues/97646

   (19) https://datatracker.ietf.org/doc/html/rfc9239.html

   (20) https://github.com/python/cpython/issues/97930

   (21) https://github.com/python/cpython/issues/97850

   (22) https://github.com/python/cpython/issues/97837

   (23) https://github.com/python/cpython/issues/97825

   (24) https://github.com/python/cpython/issues/97008

   (25) https://github.com/python/cpython/issues/82711

   (26) https://github.com/python/cpython/issues/97799

   (27) https://github.com/python/cpython/issues/97781

   (28) https://github.com/python/cpython/issues/96827

   (29) https://github.com/python/cpython/issues/95534

   (30) https://github.com/python/cpython/issues/97592

   (31) https://github.com/python/cpython/issues/97639

   (32) https://github.com/python/cpython/issues/97545

   (33) https://github.com/python/cpython/issues/73588

   (34) https://github.com/python/cpython/issues/96865

   (35) https://github.com/python/cpython/issues/97005

   (36) https://github.com/python/cpython/issues/85760

   (37) https://github.com/python/cpython/issues/96704

   (38) https://github.com/python/cpython/issues/96819

   (39) https://github.com/python/cpython/issues/95865

   (40) https://github.com/python/cpython/issues/96741

   (41) https://github.com/python/cpython/issues/96734

   (42) https://github.com/python/cpython/issues/96735

   (43) https://github.com/python/cpython/issues/46412

   (44) https://github.com/python/cpython/issues/96652

   (45) https://github.com/python/cpython/issues/68163

   (46) https://github.com/python/cpython/issues/96538

   (47) https://github.com/python/cpython/issues/96465

   (48) https://github.com/python/cpython/issues/96079

   (49) https://github.com/python/cpython/issues/96415

   (50) https://github.com/python/cpython/issues/95987

   (51) https://github.com/python/cpython/issues/96388

   (52) https://github.com/python/cpython/issues/96385

   (53) https://github.com/python/cpython/issues/96142

   (54) https://github.com/python/cpython/issues/96073

   (55) https://github.com/python/cpython/issues/89258

   (56) https://github.com/python/cpython/issues/96346

   (57) https://github.com/python/cpython/issues/96349

   (58) https://github.com/python/cpython/issues/90467

   (59) https://github.com/python/cpython/issues/96172

   (60) https://github.com/python/cpython/issues/96159

   (61) https://github.com/python/cpython/issues/96175

   (62) https://github.com/python/cpython/issues/96145

   (63) https://github.com/python/cpython/issues/96052

   (64) https://github.com/python/cpython/issues/96125

   (65) https://github.com/python/cpython/issues/96019

   (66) https://github.com/python/cpython/issues/95463

   (67) https://bugs.python.org/issue?@action=redirect&bpo=28080

   (68) https://github.com/python/cpython/issues/69142

   (69) https://github.com/python/cpython/issues/95899

   (70) https://github.com/python/cpython/issues/95736

   (71) https://github.com/python/cpython/issues/95865

   (72) https://github.com/python/cpython/issues/95861

   (73) https://github.com/python/cpython/issues/95804

   (74) https://github.com/python/cpython/issues/95704

   (75) https://github.com/python/cpython/issues/95149

   (76) https://github.com/python/cpython/issues/95609

   (77) https://github.com/python/cpython/issues/95289

   (78) https://github.com/python/cpython/issues/94909

   (79) https://github.com/python/cpython/issues/95385

   (80) https://github.com/python/cpython/issues/83901

   (81) https://github.com/python/cpython/issues/95339

   (82) https://github.com/python/cpython/issues/95045

   (83) https://github.com/python/cpython/issues/95231

   (84) https://github.com/python/cpython/issues/95097

   (85) https://github.com/python/cpython/issues/95087

   (86) https://github.com/python/cpython/issues/95199

   (87) https://github.com/python/cpython/issues/95194

   (88) https://github.com/python/cpython/issues/93899

   (89) https://github.com/python/cpython/issues/95166

   (90) https://github.com/python/cpython/issues/95132

   (91) https://github.com/python/cpython/issues/85128

   (92) https://github.com/python/cpython/issues/93157

   (93) https://github.com/python/cpython/issues/91212

   (94) https://github.com/python/cpython/issues/95077

   (95) https://github.com/python/cpython/issues/95109

   (96) https://github.com/python/cpython/issues/95105

   (97) https://github.com/python/cpython/issues/95066

   (98) https://github.com/python/cpython/issues/77617

   (99) https://github.com/python/cpython/issues/95005

   (100) https://github.com/python/cpython/issues/90085

   (101) https://github.com/python/cpython/issues/94857

   (102) https://github.com/python/cpython/issues/94821

   (103) https://github.com/python/cpython/issues/94736

   (104) https://github.com/python/cpython/issues/81620

   (105) https://github.com/python/cpython/issues/74116

   (106) https://github.com/python/cpython/issues/87822

   (107) https://github.com/python/cpython/issues/88050

   (108) https://github.com/python/cpython/issues/94637

   (109) https://github.com/python/cpython/issues/94309

   (110) https://github.com/python/cpython/issues/92546

   (111) https://github.com/python/cpython/issues/94607

   (112) https://github.com/python/cpython/issues/94619

   (113) https://github.com/python/cpython/issues/93910

   (114) https://github.com/python/cpython/issues/93896

   (115) https://github.com/python/cpython/issues/94343

   (116) https://github.com/python/cpython/issues/94382

   (117) https://github.com/python/cpython/issues/78724

   (118) https://github.com/python/cpython/issues/94510

   (119) https://github.com/python/cpython/issues/92336

   (120) https://github.com/python/cpython/issues/94398

   (121) https://github.com/python/cpython/issues/94383

   (122) https://github.com/python/cpython/issues/94379

   (123) https://peps.python.org/pep-0451/

   (124) https://github.com/python/cpython/issues/94352

   (125) https://github.com/python/cpython/issues/94318

   (126) https://github.com/python/cpython/issues/89988

   (127) https://github.com/python/cpython/issues/90016

   (128) https://github.com/python/cpython/issues/94254

   (129) https://github.com/python/cpython/issues/93259

   (130) https://github.com/python/cpython/issues/74696

   (131) https://github.com/python/cpython/issues/94216

   (132) https://github.com/python/cpython/issues/93096

   (133) https://github.com/python/cpython/issues/94207

   (134) https://github.com/python/cpython/issues/93096

   (135) https://github.com/python/cpython/issues/94226

   (136) https://github.com/python/cpython/issues/94199

   (137) https://github.com/python/cpython/issues/94214

   (138) https://github.com/python/cpython/issues/94199

   (139) https://cwe.mitre.org/data/definitions/295.html

   (140) https://github.com/python/cpython/issues/94199

   (141) https://github.com/python/cpython/issues/94199

   (142) https://peps.python.org/pep-0644/

   (143) https://github.com/python/cpython/issues/94196

   (144) https://github.com/python/cpython/issues/94182

   (145) https://github.com/python/cpython/issues/94169

   (146) https://github.com/python/cpython/issues/91742

   (147) https://github.com/python/cpython/issues/94101

   (148) https://github.com/python/cpython/issues/84753

   (149) https://github.com/python/cpython/issues/94028

   (150) https://github.com/python/cpython/issues/93973

   (151) https://github.com/python/cpython/issues/93963

   (152) https://github.com/python/cpython/issues/93858

   (153) https://github.com/python/cpython/issues/93820

   (154) https://github.com/python/cpython/issues/93847

   (155) https://github.com/python/cpython/issues/91404

   (156) https://github.com/python/cpython/issues/83499

   (157) https://github.com/python/cpython/issues/93820

   (158) https://github.com/python/cpython/issues/79512

   (159) https://github.com/python/cpython/issues/91389

   (160) https://github.com/python/cpython/issues/93626

   (161) https://github.com/python/cpython/issues/90473

   (162) https://peps.python.org/pep-0370/

   (163) https://github.com/python/cpython/issues/90494

   (164) https://github.com/python/cpython/issues/90549

   (165) https://github.com/python/cpython/issues/93521

   (166) https://github.com/python/cpython/issues/79579

   (167) https://github.com/python/cpython/issues/93421

   (168) https://github.com/python/cpython/issues/93475

   (169) https://github.com/python/cpython/issues/93370

   (170) https://github.com/python/cpython/issues/91810

   (171) https://github.com/python/cpython/issues/91162

   (172) https://github.com/python/cpython/issues/93353

   (173) https://github.com/python/cpython/issues/83658

   (174) https://github.com/python/cpython/issues/93312

   (175) https://github.com/python/cpython/issues/88123

   (176) https://github.com/python/cpython/issues/93297

   (177) https://github.com/python/cpython/issues/85308

   (178) https://github.com/python/cpython/issues/93156

   (179) https://github.com/python/cpython/issues/93162

   (180) https://github.com/python/cpython/issues/93243

   (181) https://peps.python.org/pep-0594/

   (182) https://github.com/python/cpython/issues/92886

   (183) https://github.com/python/cpython/issues/90155

   (184) https://github.com/python/cpython/issues/90817

   (185) https://github.com/python/cpython/issues/91513

   (186) https://github.com/python/cpython/issues/74696

   (187) https://github.com/python/cpython/issues/92728

   (188) https://github.com/python/cpython/issues/93033

   (189) https://github.com/python/cpython/issues/89973

   (190) https://github.com/python/cpython/issues/93044

   (191) https://github.com/python/cpython/issues/93010

   (192) https://github.com/python/cpython/issues/92986

   (193) https://github.com/python/cpython/issues/92932

   (194) https://github.com/python/cpython/issues/92675

   (195) https://github.com/python/cpython/issues/87901

   (196) https://github.com/python/cpython/issues/91922

   (197) https://github.com/python/cpython/issues/92869

   (198) https://github.com/python/cpython/issues/92839

   (199) https://github.com/python/cpython/issues/90473

   (200) https://github.com/python/cpython/issues/89325

   (201) https://github.com/python/cpython/issues/92734

   (202) https://github.com/python/cpython/issues/92671

   (203) https://github.com/python/cpython/issues/91581

   (204) https://github.com/python/cpython/issues/86388

   (205) https://github.com/python/cpython/issues/90385

   (206) https://github.com/python/cpython/issues/92550

   (207) https://github.com/python/cpython/issues/92591

   (208) https://github.com/python/cpython/issues/92445

   (209) https://github.com/python/cpython/issues/92547

   (210) https://github.com/python/cpython/issues/92530

   (211) https://github.com/python/cpython/issues/92531

   (212) https://github.com/python/cpython/issues/84131

   (213) https://github.com/python/cpython/issues/89336

   (214) https://github.com/python/cpython/issues/92391

   (215) https://github.com/python/cpython/issues/91968

   (216) https://github.com/python/cpython/issues/91810

   (217) https://github.com/python/cpython/issues/81790

   (218) https://github.com/python/cpython/issues/91760

   (219) https://github.com/python/cpython/issues/90622

   (220) https://github.com/python/cpython/issues/91577

   (221) https://github.com/python/cpython/issues/91581

   (222) https://github.com/python/cpython/issues/91539

   (223) https://github.com/python/cpython/issues/91524

   (224) https://github.com/python/cpython/issues/91447

   (225) https://github.com/python/cpython/issues/91456

   (226) https://bugs.python.org/issue?@action=redirect&bpo=47231

   (227) https://bugs.python.org/issue?@action=redirect&bpo=39064

   (228) https://bugs.python.org/issue?@action=redirect&bpo=41287

   (229) https://github.com/python/cpython/issues/90005

   (230) https://bugs.python.org/issue?@action=redirect&bpo=32547

   (231) https://bugs.python.org/issue?@action=redirect&bpo=35540

   (232) https://bugs.python.org/issue?@action=redirect&bpo=47063

   (233) https://bugs.python.org/issue?@action=redirect&bpo=47025

   (234) https://bugs.python.org/issue?@action=redirect&bpo=46951

   (235) https://bugs.python.org/issue?@action=redirect&bpo=42777

   (236) https://bugs.python.org/issue?@action=redirect&bpo=46755

   (237) https://bugs.python.org/issue?@action=redirect&bpo=45393

   (238) https://bugs.python.org/issue?@action=redirect&bpo=46642

   (239) https://bugs.python.org/issue?@action=redirect&bpo=46364

   (240) https://bugs.python.org/issue?@action=redirect&bpo=28249

   (241) https://bugs.python.org/issue?@action=redirect&bpo=46197

   (242) https://bugs.python.org/issue?@action=redirect&bpo=45924

   (243) https://bugs.python.org/issue?@action=redirect&bpo=45046

   (244) https://bugs.python.org/issue?@action=redirect&bpo=44173

   (245) https://bugs.python.org/issue?@action=redirect&bpo=42627

   (246) https://bugs.python.org/issue?@action=redirect&bpo=42047

   (247) https://bugs.python.org/issue?@action=redirect&bpo=14243

   (248) https://bugs.python.org/issue?@action=redirect&bpo=41246

   (249) https://bugs.python.org/issue?@action=redirect&bpo=39264

   (250) https://bugs.python.org/issue?@action=redirect&bpo=38693

   (251) https://bugs.python.org/issue?@action=redirect&bpo=38267

   (252) https://bugs.python.org/issue?@action=redirect&bpo=34828

   (253) https://bugs.python.org/issue?@action=redirect&bpo=32990

   (254) https://bugs.python.org/issue?@action=redirect&bpo=26253


File: python.info,  Node: Documentation<27>,  Next: Tests<27>,  Prev: Library<86>,  Up: Python 3 12 0 alpha 1

1.24.33.22 Documentation
........................

   - gh-85525(1): Remove extra row

   - gh-86404(2): Deprecated tools ‘make suspicious’ and ‘rstlint.py’
     are now removed.  They have been replaced by sphinx-lint(3).

   - gh-97741(4): Fix ‘!’ in c domain ref target syntax via a ‘conf.py’
     patch, so it works as intended to disable ref target resolution.

   - gh-96432(5): Fraction literals now support whitespace around the
     forward slash, ‘Fraction('2 / 3')’.

   - gh-96098(6): Improve discoverability of the higher level
     concurrent.futures module by providing clearer links from the lower
     level threading and multiprocessing modules.

   - gh-95957(7): What’s New 3.11 now has instructions for how to
     provide compiler and linker flags for Tcl/Tk and OpenSSL on RHEL 7
     and CentOS 7.

   - gh-95588(8): Clarified the conflicting advice given in the *note
     ast: 9. documentation about *note ast.literal_eval(): e14. being
     «safe» for use on untrusted input while at the same time warning
     that it can crash the process.  The latter statement is true and is
     deemed unfixable without a large amount of work unsuitable for a
     bugfix.  So we keep the warning and no longer claim that
     ‘literal_eval’ is safe.

   - gh-91207(9): Fix stylesheet not working in Windows CHM htmlhelp
     docs and add warning that they are deprecated.  Contributed by
     C.A.M. Gerlach.

   - gh-95454(10): Replaced incorrectly written true/false values in
     documentation.  Patch by Robert O’Shea

   - gh-95451(11): Update library documentation with *note availability
     information: 1b52. on WebAssembly platforms ‘wasm32-emscripten’ and
     ‘wasm32-wasi’.

   - gh-95415(12): Use consistent syntax for platform availability.  The
     directive now supports a content body and emits a warning when it
     encounters an unknown platform.

   - gh-94321(13): Document the PEP 246(14) style protocol type *note
     sqlite3.PrepareProtocol: 1b53.

   - gh-86128(15): Document a limitation in ThreadPoolExecutor where its
     exit handler is executed before any handlers in atexit.

   - gh-61162(16): Clarify *note sqlite3: d4. behavior when *note How to
     use the connection context manager: 1b54.

   - gh-87260(17): Align *note sqlite3: d4. argument specs with the
     actual implementation.

   - gh-86986(18): The minimum Sphinx version required to build the
     documentation is now 3.2.

   - gh-88831(19): Augmented documentation of asyncio.create_task().
     Clarified the need to keep strong references to tasks and added a
     code snippet detailing how to do this.

   - gh-86438(20): Clarify that *note -W: ac7. and *note PYTHONWARNINGS:
     da5. are matched literally and case-insensitively, rather than as
     regular expressions, in *note warnings: 118.

   - gh-93031(21): Update tutorial introduction output to use 3.10+
     SyntaxError invalid range.

   - gh-92240(22): Added release dates for «What’s New in Python 3.X»
     for 3.0, 3.1, 3.2, 3.8 and 3.10

   - bpo-47161(23): Document that *note pathlib.PurePath: 6ce. does not
     collapse initial double slashes because they denote UNC paths.

   - bpo-40838(24): Document that *note inspect.getdoc(): bef, *note
     inspect.getmodule(): 1b55, and *note inspect.getsourcefile(): 1b56.
     might return ‘None’.

   - bpo-43689(25): The ‘Differ’ documentation now also mentions other
     whitespace characters, which make it harder to understand the diff
     output.

   - bpo-38056(26): Overhaul the *note Error Handlers: 1b57.
     documentation in *note codecs: 1c.

   - bpo-13553(27): Document tkinter.Tk args.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/85525

   (2) https://github.com/python/cpython/issues/86404

   (3) https://pypi.org/project/sphinx-lint/

   (4) https://github.com/python/cpython/issues/97741

   (5) https://github.com/python/cpython/issues/96432

   (6) https://github.com/python/cpython/issues/96098

   (7) https://github.com/python/cpython/issues/95957

   (8) https://github.com/python/cpython/issues/95588

   (9) https://github.com/python/cpython/issues/91207

   (10) https://github.com/python/cpython/issues/95454

   (11) https://github.com/python/cpython/issues/95451

   (12) https://github.com/python/cpython/issues/95415

   (13) https://github.com/python/cpython/issues/94321

   (14) https://peps.python.org/pep-0246/

   (15) https://github.com/python/cpython/issues/86128

   (16) https://github.com/python/cpython/issues/61162

   (17) https://github.com/python/cpython/issues/87260

   (18) https://github.com/python/cpython/issues/86986

   (19) https://github.com/python/cpython/issues/88831

   (20) https://github.com/python/cpython/issues/86438

   (21) https://github.com/python/cpython/issues/93031

   (22) https://github.com/python/cpython/issues/92240

   (23) https://bugs.python.org/issue?@action=redirect&bpo=47161

   (24) https://bugs.python.org/issue?@action=redirect&bpo=40838

   (25) https://bugs.python.org/issue?@action=redirect&bpo=43689

   (26) https://bugs.python.org/issue?@action=redirect&bpo=38056

   (27) https://bugs.python.org/issue?@action=redirect&bpo=13553


File: python.info,  Node: Tests<27>,  Next: Build<32>,  Prev: Documentation<27>,  Up: Python 3 12 0 alpha 1

1.24.33.23 Tests
................

   - gh-95027(1): On Windows, when the Python test suite is run with the
     ‘-jN’ option, the ANSI code page is now used as the encoding for
     the stdout temporary file, rather than using UTF-8 which can lead
     to decoding errors.  Patch by Victor Stinner.

   - gh-96624(2): Fixed the failure of repeated runs of
     ‘test.test_unittest’ caused by side effects in
     ‘test_dotted_but_module_not_loaded’.

   - gh-95243(3): Mitigate the inherent race condition from using
     find_unused_port() in testSockName() by trying to find an unused
     port a few times before failing.  Patch by Ross Burton.

   - gh-95573(4): Lib/test/test_asyncio/test_ssl.py(5) exposed a bug in
     the macOS kernel where intense concurrent load on non-blocking
     sockets occasionally causes *note errno.ENOBUFS: 1b59. («No buffer
     space available») to be emitted.  FB11063974 filed with Apple, in
     the mean time as a workaround buffer size used in tests on macOS is
     decreased to avoid intermittent failures.  Patch by Fantix King.

   - gh-95280(6): Fix problem with ‘test_ssl’ ‘test_get_ciphers’ on
     systems that require perfect forward secrecy (PFS) ciphers.

   - gh-95212(7): Make multiprocessing test case
     ‘test_shared_memory_recreate’ parallel-safe.

   - gh-95218(8): Move tests for importlib.resources into
     test_importlib.resources.

   - gh-93963(9): Updated tests to use preferred location for
     ‘importlib.resources’ ABCs.

   - gh-94675(10): Add a regression test for *note re: be. exponentional
     slowdown when using rjsmin.

   - gh-91330(11): Added more tests for *note dataclasses: 33. to cover
     behavior with data descriptor-based fields.

   - gh-94208(12): ‘test_ssl’ is now checking for supported TLS version
     and protocols in more tests.

   - gh-94315(13): Tests now check for DAC override capability instead
     of relying on *note os.geteuid(): 1b5a.

   - gh-54781(14): Rename test_tk to test_tkinter, and rename
     test_ttk_guionly to test_ttk.  Patch by Victor Stinner.

   - gh-93839(15): Move ‘Lib/ctypes/test/’ to ‘Lib/test/test_ctypes/’.
     Patch by Victor Stinner.

   - gh-93951(16): In test_bdb.StateTestCase.test_skip, avoid including
     auxiliary importers.

   - gh-93957(17): Provide nicer error reporting from subprocesses in
     test_venv.EnsurePipTest.test_with_pip.

   - gh-93884(18): Add test cases for *note PyNumber_ToBase(): 1b5b.
     that take a large number or a non-int object as parameter.

   - gh-93852(19): test_asyncio, test_logging, test_socket and
     test_socketserver now create AF_UNIX domains in the current
     directory to no longer fail with ‘OSError("AF_UNIX path too long")’
     if the temporary directory (the ‘TMPDIR’ environment variable) is
     too long.  Patch by Victor Stinner.

   - gh-93353(20): regrtest now checks if a test leaks temporary files
     or directories if run with -jN option.  Patch by Victor Stinner.

   - gh-84461(21): ‘run_tests.py’ now handles cross compiling env vars
     correctly and pass ‘HOSTRUNNER’ to regression tests.

   - gh-93616(22): ‘test_modulefinder’ now creates a temporary directory
     in ‘ModuleFinderTest.setUp()’ instead of module scope.

   - gh-93575(23): Fix issue with test_unicode test_raiseMemError.  The
     test case now use ‘test.support.calcobjsize’ to calculate size of
     PyUnicode structs.  *note sys.getsizeof(): 1ac3. may return
     different size when string has UTF-8 memory.

   - gh-90473(24): WASI does not have a ‘chmod(2)’ syscall.  *note
     os.chmod(): 52a. is now a dummy function on WASI. Skip all tests
     that depend on working *note os.chmod(): 52a.

   - gh-90473(25): Skip tests on WASI that require symlinks with
     absolute paths.

   - gh-57539(26): Increase calendar test coverage for
     ‘calendar.LocaleTextCalendar.formatweekday()’.

   - gh-90473(27): Skip symlink tests on WASI. wasmtime uses
     ‘openat2(2)’ with ‘RESOLVE_BENEATH’ flag, which prevents symlinks
     with absolute paths.

   - gh-89858(28): Fix ‘test_embed’ for out-of-tree builds.  Patch by
     Kumar Aditya.

   - gh-92886(29): Fixing tests that fail when running with
     optimizations (‘-O’) in ‘test_imaplib.py’.

   - gh-92886(30): Fixing tests that fail when running with
     optimizations (‘-O’) in ‘test_zipimport.py’

   - gh-92886(31): Fixing tests that fail when running with
     optimizations (‘-O’) in ‘test_py_compile.py’

   - gh-92886(32): Fixing tests that fail when running with
     optimizations (‘-O’) in ‘test_sys_settrace.py’.

   - gh-92886(33): Fixing tests that fail when running with
     optimizations (‘-O’) in ‘_test_multiprocessing.py’

   - gh-92670(34): Skip
     ‘test_shutil.TestCopy.test_copyfile_nonexistent_dir’ test on AIX as
     the test uses a trailing slash to force the OS consider the path as
     a directory, but on AIX the trailing slash has no effect and is
     considered as a file.

   - gh-92514(35): Remove unused ‘test.support.BasicTestRunner’.  Patch
     by Jelle Zijlstra.

   - bpo-47016(36): Create a GitHub Actions workflow for verifying
     bundled pip and setuptools.  Patch by Illia Volochii and Adam
     Turner.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/95027

   (2) https://github.com/python/cpython/issues/96624

   (3) https://github.com/python/cpython/issues/95243

   (4) https://github.com/python/cpython/issues/95573

   (5) 
https://github.com/python/cpython/tree/3.14/Lib/test/test_asyncio/test_ssl.py

   (6) https://github.com/python/cpython/issues/95280

   (7) https://github.com/python/cpython/issues/95212

   (8) https://github.com/python/cpython/issues/95218

   (9) https://github.com/python/cpython/issues/93963

   (10) https://github.com/python/cpython/issues/94675

   (11) https://github.com/python/cpython/issues/91330

   (12) https://github.com/python/cpython/issues/94208

   (13) https://github.com/python/cpython/issues/94315

   (14) https://github.com/python/cpython/issues/54781

   (15) https://github.com/python/cpython/issues/93839

   (16) https://github.com/python/cpython/issues/93951

   (17) https://github.com/python/cpython/issues/93957

   (18) https://github.com/python/cpython/issues/93884

   (19) https://github.com/python/cpython/issues/93852

   (20) https://github.com/python/cpython/issues/93353

   (21) https://github.com/python/cpython/issues/84461

   (22) https://github.com/python/cpython/issues/93616

   (23) https://github.com/python/cpython/issues/93575

   (24) https://github.com/python/cpython/issues/90473

   (25) https://github.com/python/cpython/issues/90473

   (26) https://github.com/python/cpython/issues/57539

   (27) https://github.com/python/cpython/issues/90473

   (28) https://github.com/python/cpython/issues/89858

   (29) https://github.com/python/cpython/issues/92886

   (30) https://github.com/python/cpython/issues/92886

   (31) https://github.com/python/cpython/issues/92886

   (32) https://github.com/python/cpython/issues/92886

   (33) https://github.com/python/cpython/issues/92886

   (34) https://github.com/python/cpython/issues/92670

   (35) https://github.com/python/cpython/issues/92514

   (36) https://bugs.python.org/issue?@action=redirect&bpo=47016


File: python.info,  Node: Build<32>,  Next: Windows<28>,  Prev: Tests<27>,  Up: Python 3 12 0 alpha 1

1.24.33.24 Build
................

   - gh-96761(1): Fix the build process of clang compiler for
     ‘_bootstrap_python’ if LTO optimization is applied.  Patch by
     Matthias Görgens and Donghee Na.

   - gh-96883(2): ‘wasm32-emscripten’ builds for browsers now include
     *note concurrent.futures: 24. for *note asyncio: b. and *note
     unittest.mock: 10d.

   - gh-85936(3): CPython now uses the ThinLTO option as the default
     policy if the Clang compiler accepts the flag.  Patch by Donghee
     Na.

   - gh-96729(4): Ensure that Windows releases built with
     ‘Tools\msi\buildrelease.bat’ are upgradable to and from official
     Python releases.

   - gh-96269(5): Shared module targets now depend on new ‘MODULE_DEPS’
     variable, which includes ‘EXPORTSYMS’.  This fixes a build order
     issue on unsupported AIX platform.

   - gh-84461(6): ‘wasm32-emscripten’ platform no longer builds *note
     resource: c1. module, *note getresuid(): 151d, *note getresgid():
     151c, and their setters.  The APIs are stubs and not functional.

   - gh-95973(7): Add a new ‘--with-dsymutil’ configure option to link
     debug information in macOS. Patch by Pablo Galindo.

   - gh-90536(8): Use the BOLT post-link optimizer to improve
     performance, particularly on medium-to-large applications.

   - gh-93744(9): Remove the ‘configure --with-cxx-main’ build option:
     it didn’t work for many years.  Remove the ‘MAINCC’ variable from
     ‘configure’ and ‘Makefile’.  Patch by Victor Stinner.

   - gh-94801(10): Fix a regression in ‘configure’ script that caused
     some header checks to ignore custom ‘CPPFLAGS’.  The regression was
     introduced in gh-94802(11).

   - gh-95145(12): wasm32-wasi builds no longer depend on WASIX’s
     pthread stubs.  Python now has its own stubbed pthread API.

   - gh-95174(13): Python now detects missing ‘dup’ function in WASI and
     works around some missing *note errno: 5b, *note select: c6, and
     *note socket: d1. constants.

   - gh-95174(14): Python now skips missing *note socket: d1. functions
     and methods on WASI. WASI can only create sockets from existing fd
     / accept and has no netdb.

   - gh-95085(15): Platforms ‘wasm32-unknown-emscripten’ and
     ‘wasm32-unknown-wasi’ have been promoted to PEP 11(16) tier 3
     platform support.

   - gh-94847(17): Fixed ‘_decimal’ module build issue on GCC when
     compiling with LTO and pydebug.  Debug builds no longer force
     inlining of functions.

   - gh-94841(18): Fix the possible performance regression of *note
     PyObject_Free(): e61. compiled with MSVC version 1932.

   - gh-94801(19): ‘configure’ now uses custom flags like ‘ZLIB_CFLAGS’
     and ‘ZLIB_LIBS’ when searching for headers and libraries.

   - gh-94773(20): ‘deepfreeze.py’ now supports code object with
     frozensets that contain incompatible, unsortable types.

   - gh-94682(21): Build and test with OpenSSL 1.1.1q

   - gh-90005(22): Dependencies of *note readline: bf. and *note curses:
     2f. module are now detected in ‘configure’ script with
     ‘pkg-config’.  Only ‘ncurses’ / ‘ncursesw’ are detected
     automatically.  The old ‘curses’ library is not configured
     automatically.  Workaround for missing ‘termcap’ or ‘tinfo’ library
     has been removed.

   - gh-90005(23): Fix building ‘_ctypes’ extension without
     ‘pkg-config’.

   - gh-90005(24): ‘_dbm’ module dependencies are now detected by
     configure.

   - gh-94404(25): ‘makesetup’ now works around an issue with sed on
     macOS and uses correct CFLAGS for object files that end up in a
     shared extension.  Module CFLAGS are used before
     PY_STDMODULE_CFLAGS to avoid clashes with system headers.

   - gh-93939(26): C extension modules are now built by ‘configure’ and
     ‘make’ instead of ‘distutils’ and ‘setup.py’.

   - gh-93939(27): The ‘2to3’, ‘idle’, and ‘pydoc’ scripts are now
     generated and installed by ‘Makefile’ instead of ‘setup.py’.

   - gh-94280(28): Updated pegen regeneration script on Windows to find
     and use Python 3.9 or higher.  Prior to this, pegen regeneration
     already required 3.9 or higher, but the script may have used lower
     versions of Python.

   - gh-93584(29): Address race condition in ‘Makefile’ when installing
     a PGO build.  All ‘test’ and ‘install’ targets now depend on ‘all’
     target.

   - gh-93491(30): ‘configure’ now detects and reports PEP 11(31)
     support tiers.

   - gh-69093(32): Fix ‘Modules/Setup.stdlib.in’ rule for ‘_sqlite3’
     extension.

   - gh-93207(33): ‘va_start()’ with two parameters, like
     ‘va_start(args, format),’ is now required to build Python.
     ‘va_start()’ is no longer called with a single parameter.  Patch by
     Kumar Aditya.

   - gh-93202(34): Python now always use the ‘%zu’ and ‘%zd’ printf
     formats to format a ‘size_t’ or ‘Py_ssize_t’ number.  Building
     Python 3.12 requires a C11 compiler, so these printf formats are
     now always supported.  Patch by Victor Stinner.

   - gh-90473(35): Disable pymalloc and increase stack size on
     ‘wasm32-wasi’.

   - bpo-34449(36): Drop invalid compiler switch ‘-fPIC’ for HP aCC on
     HP-UX. Patch by Michael Osipov.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/96761

   (2) https://github.com/python/cpython/issues/96883

   (3) https://github.com/python/cpython/issues/85936

   (4) https://github.com/python/cpython/issues/96729

   (5) https://github.com/python/cpython/issues/96269

   (6) https://github.com/python/cpython/issues/84461

   (7) https://github.com/python/cpython/issues/95973

   (8) https://github.com/python/cpython/issues/90536

   (9) https://github.com/python/cpython/issues/93744

   (10) https://github.com/python/cpython/issues/94801

   (11) https://github.com/python/cpython/issues/94802

   (12) https://github.com/python/cpython/issues/95145

   (13) https://github.com/python/cpython/issues/95174

   (14) https://github.com/python/cpython/issues/95174

   (15) https://github.com/python/cpython/issues/95085

   (16) https://peps.python.org/pep-0011/

   (17) https://github.com/python/cpython/issues/94847

   (18) https://github.com/python/cpython/issues/94841

   (19) https://github.com/python/cpython/issues/94801

   (20) https://github.com/python/cpython/issues/94773

   (21) https://github.com/python/cpython/issues/94682

   (22) https://github.com/python/cpython/issues/90005

   (23) https://github.com/python/cpython/issues/90005

   (24) https://github.com/python/cpython/issues/90005

   (25) https://github.com/python/cpython/issues/94404

   (26) https://github.com/python/cpython/issues/93939

   (27) https://github.com/python/cpython/issues/93939

   (28) https://github.com/python/cpython/issues/94280

   (29) https://github.com/python/cpython/issues/93584

   (30) https://github.com/python/cpython/issues/93491

   (31) https://peps.python.org/pep-0011/

   (32) https://github.com/python/cpython/issues/69093

   (33) https://github.com/python/cpython/issues/93207

   (34) https://github.com/python/cpython/issues/93202

   (35) https://github.com/python/cpython/issues/90473

   (36) https://bugs.python.org/issue?@action=redirect&bpo=34449


File: python.info,  Node: Windows<28>,  Next: macOS<19>,  Prev: Build<32>,  Up: Python 3 12 0 alpha 1

1.24.33.25 Windows
..................

   - gh-98360(1): Fixes *note multiprocessing: 98. spawning child
     processes on Windows from a virtual environment to ensure that
     child processes that also use *note multiprocessing: 98. to spawn
     more children will recognize that they are in a virtual
     environment.

   - gh-98414(2): Fix ‘py.exe’ launcher handling of ‘-V:<COMPANY>/’
     option when default preferences have been set in environment
     variables or configuration files.

   - gh-97728(3): Fix possible crashes caused by the use of
     uninitialized variables when pass invalid arguments in *note
     os.system(): 1664. on Windows and in Windows-specific modules (like
     ‘winreg’).

   - gh-90989(4): Made *note Python install manager: 7db. install
     per-user by default (unless an all users install already exists),
     and clarify some text in the installer.

   - gh-97649(5): The ‘Tools’ directory is no longer installed on
     Windows

   - gh-96965(6): Update libffi to 3.4.3

   - gh-96577(7): Fixes a potential buffer overrun in ‘msilib’.

   - gh-96559(8): Fixes the Windows launcher not using the compatible
     interpretation of default tags found in configuration files when no
     tag was passed to the command.

   - gh-94781(9): Fix ‘pcbuild.proj’ to clean previous instances of
     output files in ‘Python\deepfreeze’ and ‘Python\frozen_modules’
     directories on Windows.  Patch by Charlie Zhao.

   - gh-89545(10): Updates *note platform: af. code getting the Windows
     version to use native Windows Management Instrumentation (WMI)
     queries to determine OS version, type, and architecture.

   - gh-95733(11): Make certain requirements of the Windows Store
     package optional to allow installing on earlier updates of Windows.

   - gh-95656(12): Enable the *note enable_load_extension(): a41. *note
     sqlite3: d4. API.

   - gh-95587(13): Fixes some issues where the Windows installer would
     incorrectly detect certain features of an existing install when
     upgrading.

   - gh-94399(14): Restores the behaviour of *note Python install
     manager: 7db. for ‘/usr/bin/env’ shebang lines, which will now
     search ‘PATH’ for an executable matching the given command.  If
     none is found, the usual search process is used.

   - gh-95445(15): Fixes the unsuccessful removal of the HTML document
     directory when uninstalling with Windows msi.

   - gh-95359(16): Fix *note Python install manager: 7db. handling of
     ‘py.ini’ commands (it was incorrectly expecting a ‘py_’ prefix on
     keys) and crashes when reading per-user configuration file.

   - gh-95285(17): Fix *note Python install manager: 7db. handling of
     command lines where it is only passed a short executable name.

   - gh-90844(18): Allow virtual environments to correctly launch when
     they have spaces in the path.

   - gh-94772(19): Fix incorrect handling of shebang lines in py.exe
     launcher

   - gh-94018(20): *note zipfile: 137. will now remove trailing spaces
     from path components when extracting files on Windows.

   - gh-93824(21): Drag and drop of files onto Python files in Windows
     Explorer has been enabled for Windows ARM64.

   - gh-43414(22): *note os.get_terminal_size(): 130a. now attempts to
     read the size from any provided handle, rather than only supporting
     file descriptors 0, 1 and 2.

   - gh-92817(23): Ensures that ‘py.exe’ will prefer an active virtual
     environment over default tags specified with environment variables
     or through a ‘py.ini’ file.

   - gh-92984(24): Explicitly disable incremental linking for non-Debug
     builds

   - gh-92841(25): *note asyncio: b. no longer throws ‘RuntimeError:
     Event loop is closed’ on interpreter exit after asynchronous socket
     activity.  Patch by Oleg Iarygin.

   - bpo-46907(26): Update Windows installer to use SQLite 3.38.4.

   - gh-91061(27): Accept os.PathLike for the argument to
     winsound.PlaySound

   - bpo-42658(28): Support native Windows case-insensitive path
     comparisons by using ‘LCMapStringEx’ instead of *note str.lower():
     1b5e. in ‘ntpath.normcase()’.  Add ‘LCMapStringEx’ to the ‘_winapi’
     module.

   - bpo-38704(29): Prevent installation on unsupported Windows
     versions.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98360

   (2) https://github.com/python/cpython/issues/98414

   (3) https://github.com/python/cpython/issues/97728

   (4) https://github.com/python/cpython/issues/90989

   (5) https://github.com/python/cpython/issues/97649

   (6) https://github.com/python/cpython/issues/96965

   (7) https://github.com/python/cpython/issues/96577

   (8) https://github.com/python/cpython/issues/96559

   (9) https://github.com/python/cpython/issues/94781

   (10) https://github.com/python/cpython/issues/89545

   (11) https://github.com/python/cpython/issues/95733

   (12) https://github.com/python/cpython/issues/95656

   (13) https://github.com/python/cpython/issues/95587

   (14) https://github.com/python/cpython/issues/94399

   (15) https://github.com/python/cpython/issues/95445

   (16) https://github.com/python/cpython/issues/95359

   (17) https://github.com/python/cpython/issues/95285

   (18) https://github.com/python/cpython/issues/90844

   (19) https://github.com/python/cpython/issues/94772

   (20) https://github.com/python/cpython/issues/94018

   (21) https://github.com/python/cpython/issues/93824

   (22) https://github.com/python/cpython/issues/43414

   (23) https://github.com/python/cpython/issues/92817

   (24) https://github.com/python/cpython/issues/92984

   (25) https://github.com/python/cpython/issues/92841

   (26) https://bugs.python.org/issue?@action=redirect&bpo=46907

   (27) https://github.com/python/cpython/issues/91061

   (28) https://bugs.python.org/issue?@action=redirect&bpo=42658

   (29) https://bugs.python.org/issue?@action=redirect&bpo=38704


File: python.info,  Node: macOS<19>,  Next: IDLE<15>,  Prev: Windows<28>,  Up: Python 3 12 0 alpha 1

1.24.33.26 macOS
................

   - gh-97897(1): The macOS 13 SDK includes support for the ‘mkfifoat’
     and ‘mknodat’ system calls.  Using the ‘dir_fd’ option with either
     *note os.mkfifo(): f92. or *note os.mknod(): f93. could result in a
     segfault if cpython is built with the macOS 13 SDK but run on an
     earlier version of macOS. Prevent this by adding runtime support
     for detection of these system calls («weaklinking») as is done for
     other newer syscalls on macOS.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97897


File: python.info,  Node: IDLE<15>,  Next: Tools/Demos<24>,  Prev: macOS<19>,  Up: Python 3 12 0 alpha 1

1.24.33.27 IDLE
...............

   - gh-97527(1): Fix a bug in the previous bugfix that caused IDLE to
     not start when run with 3.10.8, 3.12.0a1, and at least Microsoft
     Python 3.10.2288.0 installed without the Lib/test package.  3.11.0
     was never affected.

   - gh-65802(2): Document handling of extensions in Save As dialogs.

   - gh-95191(3): Include prompts when saving Shell (interactive input
     and output).

   - gh-95511(4): Fix the Shell context menu copy-with-prompts bug of
     copying an extra line when one selects whole lines.

   - gh-95471(5): In the Edit menu, move ‘Select All’ and add a new
     separator.

   - gh-95411(6): Enable using IDLE’s module browser with .pyw files.

   - gh-89610(7): Add .pyi as a recognized extension for IDLE on macOS.
     This allows opening stub files by double clicking on them in the
     Finder.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97527

   (2) https://github.com/python/cpython/issues/65802

   (3) https://github.com/python/cpython/issues/95191

   (4) https://github.com/python/cpython/issues/95511

   (5) https://github.com/python/cpython/issues/95471

   (6) https://github.com/python/cpython/issues/95411

   (7) https://github.com/python/cpython/issues/89610


File: python.info,  Node: Tools/Demos<24>,  Next: C API<29>,  Prev: IDLE<15>,  Up: Python 3 12 0 alpha 1

1.24.33.28 Tools/Demos
......................

   - gh-68686(1): Remove ptags and eptags scripts.

   - gh-97681(2): Remove the ‘Tools/demo/’ directory which contained old
     demo scripts.  A copy can be found in the old-demos project(3).
     Patch by Victor Stinner.

   - gh-97669(4): Remove outdated example scripts of the
     ‘Tools/scripts/’ directory.  A copy can be found in the old-demos
     project(5).  Patch by Victor Stinner.

   - gh-95853(6): The ‘wasm_build.py’ script now pre-builds Emscripten
     ports, checks for broken EMSDK versions, and warns about pkg-config
     env vars.

   - gh-95853(7): The new tool ‘Tools/wasm/wasm_builder.py’ automates
     configure, compile, and test steps for building CPython on
     WebAssembly platforms.

   - gh-95731(8): Fix handling of module docstrings in
     ‘Tools/i18n/pygettext.py’.

   - gh-93939(9): Add script ‘Tools/scripts/check_modules.py’ to check
     and validate builtin and shared extension modules.  The script also
     handles ‘Modules/Setup’ and will eventually replace ‘setup.py’.

   - gh-94538(10): Fix Argument Clinic output to custom file
     destinations.  Patch by Erlend E. Aasland.

   - gh-94430(11): Allow parameters named ‘module’ and ‘self’ with
     custom C names in Argument Clinic.  Patch by Erlend E. Aasland

   - gh-86087(12): The ‘Tools/scripts/parseentities.py’ script used to
     parse HTML4 entities has been removed.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/68686

   (2) https://github.com/python/cpython/issues/97681

   (3) https://github.com/gvanrossum/old-demos

   (4) https://github.com/python/cpython/issues/97669

   (5) https://github.com/gvanrossum/old-demos

   (6) https://github.com/python/cpython/issues/95853

   (7) https://github.com/python/cpython/issues/95853

   (8) https://github.com/python/cpython/issues/95731

   (9) https://github.com/python/cpython/issues/93939

   (10) https://github.com/python/cpython/issues/94538

   (11) https://github.com/python/cpython/issues/94430

   (12) https://github.com/python/cpython/issues/86087


File: python.info,  Node: C API<29>,  Prev: Tools/Demos<24>,  Up: Python 3 12 0 alpha 1

1.24.33.29 C API
................

   - gh-98393(1): The *note PyUnicode_FSDecoder(): 798. function no
     longer accepts bytes-like paths, like *note bytearray: 344. and
     *note memoryview: 165. types: only the exact *note bytes: 192. type
     is accepted for bytes strings.  Patch by Victor Stinner.

   - gh-91051(2): Add *note PyType_Watch(): 787. and related APIs to
     allow callbacks on *note PyType_Modified(): 1b63.

   - gh-95756(3): Lazily create and cache ‘co_’ attributes for better
     performance for code getters.

   - gh-96512(4): Configuration for the *note integer string conversion
     length limitation: 80c. now lives in the PyConfig C API struct.

   - gh-95589(5): Extensions classes that set ‘tp_dictoffset’ and
     ‘tp_weaklistoffset’ lose the support for multiple inheritance, but
     are now safe.  Extension classes should use *note
     Py_TPFLAGS_MANAGED_DICT: 60f. and *note Py_TPFLAGS_MANAGED_WEAKREF:
     77d. instead.

   - gh-95781(6): An unrecognized format character in *note
     PyUnicode_FromFormat(): 62b. and *note PyUnicode_FromFormatV():
     795. now sets a *note SystemError: 796.  In previous versions it
     caused all the rest of the format string to be copied as-is to the
     result string, and any extra arguments discarded.

   - gh-92678(7): Restore the 3.10 behavior for multiple inheritance of
     C extension classes that store their dictionary at the end of the
     struct.

   - gh-92678(8): Support C extensions using managed dictionaries by
     setting the ‘Py_TPFLAGS_MANAGED_DICT’ flag.

   - gh-93274(9): API for implementing vectorcall (*note
     Py_TPFLAGS_HAVE_VECTORCALL: 777, *note PyVectorcall_NARGS(): 778.
     and *note PyVectorcall_Call(): 779.) was added to the limited API
     and stable ABI.

   - gh-95504(10): Fix sign placement when specifying width or precision
     in *note PyUnicode_FromFormat(): 62b. and *note
     PyUnicode_FromFormatV(): 795.  Patch by Philip Georgi.

   - gh-93012(11): The *note Py_TPFLAGS_HAVE_VECTORCALL: 777. flag is
     now removed from a class when the class’s *note __call__(): 77b.
     method is reassigned.  This makes vectorcall safe to use with
     mutable types (i.e.  heap types without the ‘immutable’ flag).
     Mutable types that do not override *note tp_call: 77c. now inherit
     the *note Py_TPFLAGS_HAVE_VECTORCALL: 777. flag.

   - gh-95388(12): Creating *note immutable types: 3cf. with mutable
     bases is deprecated and is planned to be disabled in Python 3.14.

   - gh-92678(13): Adds unstable C-API functions
     ‘_PyObject_VisitManagedDict’ and ‘_PyObject_ClearManagedDict’ to
     allow C extensions to allow the VM to manage their object’s
     dictionaries.

   - gh-94936(14): Added *note PyCode_GetVarnames(): 97e, *note
     PyCode_GetCellvars(): 97f. and *note PyCode_GetFreevars(): 980. for
     accessing ‘co_varnames’, ‘co_cellvars’ and ‘co_freevars’
     respectively via the C API.

   - gh-94930(15): Fix ‘SystemError’ raised when *note
     PyArg_ParseTupleAndKeywords(): 624. is used with ‘#’ in ‘(...)’ but
     without ‘PY_SSIZE_T_CLEAN’ defined.

   - gh-94731(16): Python again uses C-style casts for most casting
     operations when compiled with C++.  This may trigger compiler
     warnings, if they are enabled with e.g.  ‘-Wold-style-cast’ or
     ‘-Wzero-as-null-pointer-constant’ options for ‘g++’.

   - gh-93937(17): The following frame functions and type are now
     directly available with ‘#include <Python.h>’, it’s no longer
     needed to add ‘#include <frameobject.h>’:

        * *note PyFrame_Check(): 989.

        * *note PyFrame_GetBack(): 98a.

        * *note PyFrame_GetBuiltins(): 970.

        * *note PyFrame_GetGenerator(): 971.

        * *note PyFrame_GetGlobals(): 972.

        * *note PyFrame_GetLasti(): 973.

        * *note PyFrame_GetLocals(): 661.

        * *note PyFrame_Type: 98b.

     Patch by Victor Stinner.

   - gh-91321(18): Fix the compatibility of the Python C API with C++
     older than C++11.  Patch by Victor Stinner.

   - gh-91731(19): Avoid defining the ‘static_assert’ when compiling
     with C++ 11, where this is a keyword and redefining it can lead to
     undefined behavior.  Patch by Pablo Galindo

   - gh-89546(20): *note PyType_FromMetaclass(): 773. (and other
     ‘PyType_From*’ functions) now check that offsets and the base
     class’s *note tp_basicsize: b80. fit in the new class’s
     ‘tp_basicsize’.

   - gh-93503(21): Add two new public functions to the public C-API,
     *note PyEval_SetProfileAllThreads(): 782. and *note
     PyEval_SetTraceAllThreads(): 664, that allow to set tracing and
     profiling functions in all running threads in addition to the
     calling one.  Also, two analogous functions to the *note threading:
     f3. module (*note threading.setprofile_all_threads(): 6f1. and
     *note threading.settrace_all_threads(): 6f0.) that allow to do the
     same from Python.  Patch by Pablo Galindo

   - gh-93442(22): Add C++ overloads for _Py_CAST_impl() to handle
     0/NULL. This will allow C++ extensions that pass 0 or NULL to
     macros using _Py_CAST() to continue to compile.

   - gh-93466(23): Slot IDs in PyType_Spec may not be repeated.  The
     documentation was updated to mention this.  For some cases of
     repeated slots, PyType_FromSpec and related functions will now
     raise an exception.

   - gh-92898(24): Fix C++ compiler warnings when casting function
     arguments to ‘PyObject*’.  Patch by Serge Guelton.

   - gh-93103(25): Deprecate global configuration variables, like *note
     Py_IgnoreEnvironmentFlag: 40a, in the documentation: the *note
     Py_InitializeFromConfig(): 3f6. API should be instead.  Patch by
     Victor Stinner.

   - gh-77782(26): Deprecate global configuration variable like *note
     Py_IgnoreEnvironmentFlag: 40a.: the *note
     Py_InitializeFromConfig(): 3f6. API should be instead.  Patch by
     Victor Stinner.

   - gh-92913(27): Ensures changes to *note
     PyConfig.module_search_paths: 643. are ignored unless *note
     PyConfig.module_search_paths_set: 806. is set

   - gh-92781(28): Avoid mixing declarations and code in the C API to
     fix the compiler warning: «ISO C90 forbids mixed declarations and
     code» [-Werror=declaration-after-statement].  Patch by Victor
     Stinner.

   - gh-92651(29): Remove the ‘token.h’ header file.  There was never
     any public tokenizer C API. The ‘token.h’ header file was only
     designed to be used by Python internals.  Patch by Victor Stinner.

   - gh-92536(30): Remove legacy Unicode APIs based on ‘Py_UNICODE*’.

   - gh-85858(31): Remove the ‘PyUnicode_InternImmortal()’ function and
     the ‘SSTATE_INTERNED_IMMORTAL’ macro.  Patch by Victor Stinner.

   - gh-92193(32): Add new function *note PyFunction_SetVectorcall():
     783. to the C API which sets the vectorcall field of a given *note
     PyFunctionObject: 784.

     Warning: extensions using this API must preserve the behavior of
     the unaltered function!

   - gh-59121(33): Fixed an assert that prevented ‘PyRun_InteractiveOne’
     from providing tracebacks when parsing from the provided FD.

   - bpo-45383(34): The *note PyType_FromSpec(): 79e. API will now find
     and use a metaclass based on the provided bases.  An error will be
     raised if there is a metaclass conflict.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/98393

   (2) https://github.com/python/cpython/issues/91051

   (3) https://github.com/python/cpython/issues/95756

   (4) https://github.com/python/cpython/issues/96512

   (5) https://github.com/python/cpython/issues/95589

   (6) https://github.com/python/cpython/issues/95781

   (7) https://github.com/python/cpython/issues/92678

   (8) https://github.com/python/cpython/issues/92678

   (9) https://github.com/python/cpython/issues/93274

   (10) https://github.com/python/cpython/issues/95504

   (11) https://github.com/python/cpython/issues/93012

   (12) https://github.com/python/cpython/issues/95388

   (13) https://github.com/python/cpython/issues/92678

   (14) https://github.com/python/cpython/issues/94936

   (15) https://github.com/python/cpython/issues/94930

   (16) https://github.com/python/cpython/issues/94731

   (17) https://github.com/python/cpython/issues/93937

   (18) https://github.com/python/cpython/issues/91321

   (19) https://github.com/python/cpython/issues/91731

   (20) https://github.com/python/cpython/issues/89546

   (21) https://github.com/python/cpython/issues/93503

   (22) https://github.com/python/cpython/issues/93442

   (23) https://github.com/python/cpython/issues/93466

   (24) https://github.com/python/cpython/issues/92898

   (25) https://github.com/python/cpython/issues/93103

   (26) https://github.com/python/cpython/issues/77782

   (27) https://github.com/python/cpython/issues/92913

   (28) https://github.com/python/cpython/issues/92781

   (29) https://github.com/python/cpython/issues/92651

   (30) https://github.com/python/cpython/issues/92536

   (31) https://github.com/python/cpython/issues/85858

   (32) https://github.com/python/cpython/issues/92193

   (33) https://github.com/python/cpython/issues/59121

   (34) https://bugs.python.org/issue?@action=redirect&bpo=45383


File: python.info,  Node: Python 3 11 0 beta 1,  Next: Python 3 11 0 alpha 7,  Prev: Python 3 12 0 alpha 1,  Up: Changelog

1.24.34 Python 3.11.0 beta 1
----------------------------

'Release date: 2022-05-06'

* Menu:

* Security: Security<28>.
* Core and Builtins: Core and Builtins<83>.
* Library: Library<87>.
* Core and Builtins: Core and Builtins<84>.
* Build: Build<33>.
* Core and Builtins: Core and Builtins<85>.
* Library: Library<88>.
* Documentation: Documentation<28>.
* Tests: Tests<28>.
* Build: Build<34>.
* Windows: Windows<29>.
* macOS: macOS<20>.
* Tools/Demos: Tools/Demos<25>.
* C API: C API<30>.


File: python.info,  Node: Security<28>,  Next: Core and Builtins<83>,  Up: Python 3 11 0 beta 1

1.24.34.1 Security
..................

   - gh-57684(1): Add the *note -P: 7c2. command line option and the
     *note PYTHONSAFEPATH: 7c3. environment variable to not prepend a
     potentially unsafe path to *note sys.path: 3e4.  Patch by Victor
     Stinner.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/57684


File: python.info,  Node: Core and Builtins<83>,  Next: Library<87>,  Prev: Security<28>,  Up: Python 3 11 0 beta 1

1.24.34.2 Core and Builtins
...........................

   - gh-89519(1): Chaining classmethod descriptors (introduced in
     bpo-19072(2)) is deprecated.  It can no longer be used to wrap
     other descriptors such as property().  The core design of this
     feature was flawed, and it caused a number of downstream problems.

   - gh-92345(3): ‘pymain_run_python()’ now imports ‘readline’ and
     ‘rlcompleter’ before sys.path is extended to include the current
     working directory of an interactive interpreter.  Non-interactive
     interpreters are not affected.

   - bpo-43857(4): Improve the *note AttributeError: 5f0. message when
     deleting a missing attribute.  Patch by Géry Ogam.

   - gh-92245(5): Make sure that PEP 523 is respected in all cases.  In
     3.11a7, specialization may have prevented Python-to-Python calls
     respecting PEP 523.

   - gh-92203(6): Add a closure keyword-only parameter to *note exec():
     4a3.  It can only be specified when exec-ing a code object that
     uses free variables.  When specified, it must be a tuple, with
     exactly the number of cell variables referenced by the code object.
     closure has a default value of ‘None’, and it must be ‘None’ if the
     code object doesn’t refer to any free variables.

   - gh-91173(7): Disable frozen modules in debug builds.  Patch by
     Kumar Aditya.

   - gh-92114(8): Improve error message when subscript a type with
     ‘__class_getitem__’ set to ‘None’.

   - gh-92112(9): Fix crash triggered by an evil custom ‘mro()’ on a
     metaclass.

   - gh-92063(10): The ‘PRECALL_METHOD_DESCRIPTOR_FAST_WITH_KEYWORDS’
     instruction now ensures methods are called only on objects of the
     correct type.

   - gh-92031(11): Deoptimize statically allocated code objects during
     ‘Py_FINALIZE()’ so that future ‘_PyCode_Quicken’ calls always start
     with unquickened code.

   - gh-92036(12): Fix a crash in subinterpreters related to the garbage
     collector.  When a subinterpreter is deleted, untrack all objects
     tracked by its GC. To prevent a crash in deallocator functions
     expecting objects to be tracked by the GC, leak a strong reference
     to these objects on purpose, so they are never deleted and their
     deallocator functions are not called.  Patch by Victor Stinner.

   - gh-92032(13): The interpreter can now autocomplete soft keywords,
     as of now ‘match’, ‘case’, and ‘_’ (wildcard pattern) from PEP
     634(14).

   - gh-87999(15): The warning emitted by the Python parser for a
     numeric literal immediately followed by keyword has been changed
     from deprecation warning to syntax warning.

   - gh-91869(16): Fix an issue where specialized opcodes with extended
     arguments could produce incorrect tracing output or lead to
     assertion failures.

   - gh-91603(17): Speed up *note types.UnionType: 2a7. instantiation.
     Based on patch provided by Yurii Karabas.

   - gh-89373(18): If Python is built in debug mode, Python now ensures
     that deallocator functions leave the current exception unchanged.
     Patch by Victor Stinner.

   - gh-91632(19): Fix a minor memory leak at exit: release the memory
     of the ‘generic_alias_iterator’ type.  Patch by Donghee Na.

   - gh-81548(20): Octal escapes with value larger than ‘0o377’ now
     produce a *note DeprecationWarning: 1a3.  In a future Python
     version they will be a *note SyntaxWarning: 1ae. and eventually a
     *note SyntaxError: 18e.

   - bpo-43950(21): Use a single compact table for line starts, ends and
     column offsets.  Reduces memory consumption for location info by
     half

   - gh-91102(22): Use Argument Clinic for ‘EncodingMap’.  Patch by Oleg
     Iarygin.

   - gh-91636(23): Fixed a crash in a garbage-collection edge-case, in
     which a ‘PyFunction_Type.tp_clear’ function could leave a python
     function object in an inconsistent state.

   - gh-91603(24): Speed up *note isinstance(): 2ad. and *note
     issubclass(): 9c6. checks for *note types.UnionType: 2a7.  Patch by
     Yurii Karabas.

   - gh-91625(25): Fixed a bug in which adaptive opcodes ignored any
     preceding ‘EXTENDED_ARG’s on specialization failure.

   - gh-78607(26): The LLTRACE special build now looks for the name
     ‘__lltrace__’ defined in module globals, rather than the name
     ‘__ltrace__’, which had been introduced as a typo.

   - gh-91576(27): Speed up iteration of ascii strings by 50%.  Patch by
     Kumar Aditya.

   - gh-89279(28): Improve interpreter performance on Windows by
     inlining a few specific macros.

   - gh-91502(29): Add a new ‘_PyFrame_IsEntryFrame()’ API function, to
     check if a *note PyFrameObject: 98d. is an entry frame.  Patch by
     Pablo Galindo.

   - gh-91266(30): Refactor the ‘bytearray’ strip methods ‘strip’,
     ‘lstrip’ and ‘rstrip’ to use a common implementation.

   - gh-91479(31): Replaced the ‘__note__’ field of *note BaseException:
     7d8. (added in an earlier version of 3.11) with the final design of
     PEP 678(32).  Namely, *note BaseException: 7d8. gets an
     ‘add_note()’ method, and its ‘__notes__’ field is created when
     necessary.

   - gh-46055(33): Speed up right shift of negative integers, by
     removing unnecessary creation of temporaries.  Original patch by
     Xinhang Xu, reworked by Mark Dickinson.

   - gh-91462(34): Make the interpreter’s low-level tracing (lltrace)
     feature output more readable by displaying opcode names (rather
     than just numbers), and by displaying stack contents before each
     opcode.

   - gh-89455(35): Fixed an uninitialized bool value in the traceback
     printing code path that was introduced by the initial bpo-45292(36)
     exception groups work.

   - gh-91421(37): Fix a potential integer overflow in _Py_DecodeUTF8Ex.

   - gh-91428(38): Add ‘static const char *const _PyOpcode_OpName[256] =
     {...};’ to ‘opcode.h’ for debug builds to assist in debugging the
     Python interpreter.  It is now more convenient to make various
     forms of debugging output more human-readable by including opcode
     names rather than just the corresponding decimal digits.

   - bpo-47120(39): Make *note POP_JUMP_IF_TRUE: 1a47, *note
     POP_JUMP_IF_FALSE: 1a48, *note POP_JUMP_IF_NONE: 1b67. and *note
     POP_JUMP_IF_NOT_NONE: 1b68. virtual, mapping to new relative jump
     opcodes.

   - bpo-45317(40): Add internal documentation explaining design of new
     (for 3.11) frame stack.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89519

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19072

   (3) https://github.com/python/cpython/issues/92345

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43857

   (5) https://github.com/python/cpython/issues/92245

   (6) https://github.com/python/cpython/issues/92203

   (7) https://github.com/python/cpython/issues/91173

   (8) https://github.com/python/cpython/issues/92114

   (9) https://github.com/python/cpython/issues/92112

   (10) https://github.com/python/cpython/issues/92063

   (11) https://github.com/python/cpython/issues/92031

   (12) https://github.com/python/cpython/issues/92036

   (13) https://github.com/python/cpython/issues/92032

   (14) https://peps.python.org/pep-0634/

   (15) https://github.com/python/cpython/issues/87999

   (16) https://github.com/python/cpython/issues/91869

   (17) https://github.com/python/cpython/issues/91603

   (18) https://github.com/python/cpython/issues/89373

   (19) https://github.com/python/cpython/issues/91632

   (20) https://github.com/python/cpython/issues/81548

   (21) https://bugs.python.org/issue?@action=redirect&bpo=43950

   (22) https://github.com/python/cpython/issues/91102

   (23) https://github.com/python/cpython/issues/91636

   (24) https://github.com/python/cpython/issues/91603

   (25) https://github.com/python/cpython/issues/91625

   (26) https://github.com/python/cpython/issues/78607

   (27) https://github.com/python/cpython/issues/91576

   (28) https://github.com/python/cpython/issues/89279

   (29) https://github.com/python/cpython/issues/91502

   (30) https://github.com/python/cpython/issues/91266

   (31) https://github.com/python/cpython/issues/91479

   (32) https://peps.python.org/pep-0678/

   (33) https://github.com/python/cpython/issues/46055

   (34) https://github.com/python/cpython/issues/91462

   (35) https://github.com/python/cpython/issues/89455

   (36) https://bugs.python.org/issue?@action=redirect&bpo=45292

   (37) https://github.com/python/cpython/issues/91421

   (38) https://github.com/python/cpython/issues/91428

   (39) https://bugs.python.org/issue?@action=redirect&bpo=47120

   (40) https://bugs.python.org/issue?@action=redirect&bpo=45317


File: python.info,  Node: Library<87>,  Next: Core and Builtins<84>,  Prev: Core and Builtins<83>,  Up: Python 3 11 0 beta 1

1.24.34.3 Library
.................

   - bpo-47197(1): ctypes used to mishandle ‘void’ return types, so that
     for instance a function declared like ‘ctypes.CFUNCTYPE(None,
     ctypes.c_int)’ would be called with signature ‘int f(int)’ instead
     of ‘void f(int)’.  Wasm targets require function pointers to be
     called with the correct signatures so this led to crashes.  The
     problem is now fixed.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=47197


File: python.info,  Node: Core and Builtins<84>,  Next: Build<33>,  Prev: Library<87>,  Up: Python 3 11 0 beta 1

1.24.34.4 Core and Builtins
...........................

   - bpo-47120(1): Make opcodes ‘JUMP_IF_TRUE_OR_POP’ and
     ‘JUMP_IF_FALSE_OR_POP’ relative rather than absolute.

   - bpo-47177(2): Replace the ‘f_lasti’ member of the internal
     ‘_PyInterpreterFrame’ structure with a ‘prev_instr’ pointer, which
     reduces overhead in the main interpreter loop.  The ‘f_lasti’
     attribute of Python-layer frame objects is preserved for
     backward-compatibility.

   - bpo-46961(3): Integer mod/remainder operations, including the
     three-argument form of *note pow(): 1a4, now consistently return
     ints from the global small integer cache when applicable.

   - bpo-46962(4): Classes and functions that unconditionally declared
     their docstrings ignoring the ‘--without-doc-strings’ compilation
     flag no longer do so.

     The classes affected are ‘ctypes.UnionType’, *note
     pickle.PickleBuffer: 1762, ‘testcapi.RecursingInfinitelyError’, and
     *note types.GenericAlias: 9ee.

     The functions affected are 24 methods in *note ctypes: 2e.

     Patch by Oleg Iarygin.

   - bpo-46942(5): Use Argument Clinic for the *note types.MethodType:
     1b6b. constructor.  Patch by Oleg Iarygin.

   - bpo-46764(6): Fix wrapping bound methods with @classmethod

   - bpo-43464(7): Optimize *note set.intersection(): 1b6c. for non-set
     arguments.

   - bpo-46721(8): Optimize *note set.issuperset(): 1b6d. for non-set
     argument.

   - bpo-46509(9): Add type-specialized versions of the ‘Py_DECREF()’,
     and use them for ‘float’, ‘int’, ‘str’, ‘bool’, and ‘None’ to avoid
     pointer-chasing at runtime where types are known at C compile time.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=47120

   (2) https://bugs.python.org/issue?@action=redirect&bpo=47177

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46961

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46962

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46942

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46764

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43464

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46721

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46509


File: python.info,  Node: Build<33>,  Next: Core and Builtins<85>,  Prev: Core and Builtins<84>,  Up: Python 3 11 0 beta 1

1.24.34.5 Build
...............

   - bpo-46045(1): Do not use POSIX semaphores on NetBSD

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46045


File: python.info,  Node: Core and Builtins<85>,  Next: Library<88>,  Prev: Build<33>,  Up: Python 3 11 0 beta 1

1.24.34.6 Core and Builtins
...........................

   - bpo-36819(1): Fix crashes in built-in encoders with error handlers
     that return position less or equal than the starting position of
     non-encodable characters.

   - bpo-34093(2): ‘marshal.dumps()’ uses ‘FLAG_REF’ for all interned
     strings.  This makes output more deterministic and helps
     reproducible build.

   - bpo-26579(3): Added ‘object.__getstate__’ which provides the
     default implementation of the ‘__getstate__()’ method.

     Copying and pickling instances of subclasses of builtin types
     bytearray, set, frozenset, collections.OrderedDict,
     collections.deque, weakref.WeakSet, and datetime.tzinfo now copies
     and pickles instance attributes implemented as slots.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36819

   (2) https://bugs.python.org/issue?@action=redirect&bpo=34093

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26579


File: python.info,  Node: Library<88>,  Next: Documentation<28>,  Prev: Core and Builtins<85>,  Up: Python 3 11 0 beta 1

1.24.34.7 Library
.................

   - gh-87901(1): Add the 'encoding' parameter to *note os.popen(): 31a.

   - gh-90997(2): Fix an issue where *note dis: 3c. utilities may
     interpret populated inline cache entries as valid instructions.

   - gh-92332(3): Deprecate *note typing.Text: 360. (removal of the
     class is currently not planned).  Patch by Alex Waygood.

   - gh-78157(4): Deprecate nested classes in enum definitions becoming
     members – in 3.13 they will be normal classes; add ‘member’ and
     ‘nonmember’ functions to allow control over results now.

   - gh-92356(5): Fixed a performance regression in ctypes function
     calls.

   - gh-90997(6): Show the actual named values stored in inline caches
     when ‘show_caches=True’ is passed to *note dis: 3c. utilities.

   - gh-92301(7): Prefer ‘close_range()’ to iterating over procfs for
     file descriptor closing in *note subprocess: dc. for better
     performance.

   - gh-67248(8): Sort the miscellaneous topics in Cmd.do_help()

   - gh-92210(9): Port ‘socket.__init__’ to Argument Clinic.  Patch by
     Cinder.

   - gh-80010(10): Add support for generalized ISO 8601 parsing to *note
     datetime.datetime.fromisoformat(): 82b, *note
     datetime.date.fromisoformat(): 829. and *note
     datetime.time.fromisoformat(): 82a.  Patch by Paul Ganssle.

   - gh-92118(11): Fix a 3.11 regression in *note contextmanager():
     140a, which caused it to propagate exceptions with incorrect
     tracebacks.

   - gh-90887(12): Adding ‘COPYFILE_STAT’, ‘COPYFILE_ACL’ and
     ‘COPYFILE_XATTR’ constants for ‘os.fcopyfile()’ available in macOs.

   - gh-91215(13): For *note @~dataclasses.dataclass: 4e2, add
     'weakref_slot'.  The new parameter defaults to ‘False’.  If true,
     and if ‘slots=True’, add a slot named ‘"__weakref__"’, which will
     allow instances to be weakref’d.  Contributed by Eric V. Smith

   - gh-85984(14): New function os.login_tty() for Unix.

   - gh-92128(15): Add *note __class_getitem__(): 944. to *note
     logging.LoggerAdapter: 14fd. and *note logging.StreamHandler: 1400,
     allowing them to be parameterized at runtime.  Patch by Alex
     Waygood.

   - gh-92049(16): Forbid pickling constants ‘re._constants.SUCCESS’
     etc.  Previously, pickling did not fail, but the result could not
     be unpickled.

   - gh-92062(17): *note inspect.Parameter: 4e5. now raises *note
     ValueError: 2ec. if ‘name’ is a keyword, in addition to the
     existing check that it is an identifier.

   - gh-87390(18): Add an ‘__unpacked__’ attribute to *note
     types.GenericAlias: 9ee.  Patch by Jelle Zijlstra.

   - gh-88089(19): Add support for generic *note typing.NamedTuple: 331.

   - gh-91996(20): New http.HTTPMethod enum to represent all the
     available HTTP request methods in a convenient way

   - gh-91984(21): Modified test strings in test_argparse.py to not
     contain trailing spaces before end of line.

   - gh-91952(22): Add ‘encoding="locale"’ support to
     ‘TextIOWrapper.reconfigure()’.

   - gh-91954(23): Add 'encoding' and 'errors' arguments to *note
     subprocess.getoutput(): 11c5. and *note
     subprocess.getstatusoutput(): 11c6.

   - bpo-47029(24): Always close the read end of the pipe used by *note
     multiprocessing.Queue: 1b71. 'after' the last write of buffered
     data to the write end of the pipe to avoid *note BrokenPipeError:
     125e. at garbage collection and at *note
     multiprocessing.Queue.close(): 1b72. calls.  Patch by Géry Ogam.

   - gh-91928(25): Add ‘datetime.UTC’ alias for ‘datetime.timezone.utc’.

     Patch by Kabir Kwatra.

   - gh-68966(26): The ‘mailcap’ module is now deprecated and will be
     removed in Python 3.13.  See PEP 594(27) for the rationale and the
     *note mimetypes: 93. module for an alternative.  Patch by Victor
     Stinner.

   - gh-91401(28): Provide a way to disable *note subprocess: dc. use of
     ‘vfork()’ just in case it is ever needed and document the existing
     mechanism for ‘posix_spawn()’.

   - gh-64783(29): Fix *note signal.NSIG: 1b73. value on FreeBSD to
     accept signal numbers greater than 32, like ‘signal.SIGRTMIN’ and
     ‘signal.SIGRTMAX’.  Patch by Victor Stinner.

   - gh-91910(30): Add missing f prefix to f-strings in error messages
     from the *note multiprocessing: 98. and *note asyncio: b. modules.

   - gh-91860(31): Add *note typing.dataclass_transform(): 6fc,
     implementing PEP 681(32).  Patch by Jelle Zijlstra.

   - gh-91832(33): Add ‘required’ attribute to *note argparse.Action:
     1b74. repr output.

   - gh-91827(34): In the *note tkinter: f6. module add method
     ‘info_patchlevel()’ which returns the exact version of the Tcl
     library as a named tuple similar to *note sys.version_info: 8b0.

   - gh-84461(35): Add *note -enable-wasm-pthreads: 1b75. to enable
     pthreads support for WASM builds.  ‘Emscripten/node’ no longer has
     threading enabled by default.  Include additional file systems.

   - gh-91821(36): Fix unstable ‘test_from_tuple’ test in
     ‘test_decimal.py’.

   - gh-91217(37): Deprecate the xdrlib module.

   - gh-91217(38): Deprecate the uu module.

   - gh-91760(39): More strict rules will be applied for numerical group
     references and group names in regular expressions.  For now, a
     deprecation warning is emitted for group references and group names
     which will be errors in future Python versions.

   - gh-84461(40): Add provisional *note sys._emscripten_info: 1b76.
     named tuple with build-time and run-time information about
     Emscripten platform.

   - gh-90623(41): *note signal.raise_signal(): 1b77. and *note
     os.kill(): 156f. now check immediately for pending signals.  Patch
     by Victor Stinner.

   - gh-91734(42): Fix OSS audio support on Solaris.

   - gh-90633(43): Include the passed value in the exception thrown by
     *note typing.assert_never(): 8b7.  Patch by Jelle Zijlstra.

   - gh-91700(44): Compilation of regular expression containing a
     conditional expression ‘(?(group)...)’ now raises an appropriate
     ‘re.error’ if the group number refers to not defined group.
     Previously an internal RuntimeError was raised.

   - gh-91231(45): Add an optional keyword 'shutdown_timeout' parameter
     to the ‘multiprocessing.BaseManager’ constructor.  Kill the process
     if terminate() takes longer than the timeout.  Patch by Victor
     Stinner.

   - gh-91621(46): Fix *note typing.get_type_hints(): 8c1. for *note
     collections.abc.Callable: 9ed.  Patch by Shantanu Jain.

   - gh-90568(47): Parsing ‘\N’ escapes of Unicode Named Character
     Sequences in a *note regular expression: be. raises now ‘re.error’
     instead of ‘TypeError’.

   - gh-91670(48): Remove deprecated ‘SO’ config variable in *note
     sysconfig: e1.

   - gh-91217(49): Deprecate the telnetlib module.

   - gh-91217(50): Deprecate the sunau module.

   - gh-91217(51): Deprecate the spwd module.

   - gh-91217(52): Deprecate the sndhdr module, as well as inline needed
     functionality for ‘email.mime.MIMEAudio’.

   - gh-91616(53): *note re: be. module, fix *note fullmatch(): 1188.
     mismatch when using Atomic Grouping or Possessive Quantifiers.

   - gh-91217(54): Deprecate the “pipes” module.

   - gh-91217(55): Deprecate the ossaudiodev module.

   - bpo-47256(56): *note re: be. module, limit the maximum capturing
     group to 1,073,741,823 in 64-bit build, this increases the depth of
     backtracking.

   - gh-91217(57): Deprecate the nis module.

   - gh-91595(58): Fix the comparison of character and integer inside
     ‘Tools.gdb.libpython.write_repr()’.  Patch by Yu Liu.

   - gh-74166(59): Add option to raise all errors from *note
     create_connection(): 883. in an *note ExceptionGroup: 4d3. when it
     fails to create a connection.  The default remains to raise only
     the last error that had occurred when multiple addresses were
     tried.

   - gh-91487(60): Optimize asyncio UDP speed, over 100 times faster
     when transferring a large file.

   - gh-91575(61): Update case-insensitive matching in the *note re: be.
     module to the latest Unicode version.

   - gh-90622(62): In ‘concurrent.futures.process.ProcessPoolExecutor’
     disallow the «fork» multiprocessing start method when the new
     ‘max_tasks_per_child’ feature is used as the mix of threads+fork
     can hang the child processes.  Default to using the safe «spawn»
     start method in that circumstance if no ‘mp_context’ was supplied.

   - gh-89022(63): In *note sqlite3: d4, ‘SQLITE_MISUSE’ result codes
     are now mapped to *note InterfaceError: 88e. instead of *note
     ProgrammingError: 305.  Also, more accurate exceptions are raised
     when binding parameters fail.  Patch by Erlend E. Aasland.

   - gh-91526(64): Stop calling ‘os.device_encoding(file.fileno())’ in
     ‘TextIOWrapper’.  It was complex, never documented, and didn’t work
     for most cases.  (Patch by Inada Naoki.)

   - gh-88116(65): Change the frame-related functions in the *note
     inspect: 82. module to return a regular object (that is backwards
     compatible with the old tuple-like interface) that include the
     extended PEP 657(66) position information (end line number, column
     and end column).  The affected functions are: *note
     inspect.getframeinfo(): 860, *note inspect.getouterframes(): 861,
     *note inspect.getinnerframes(): 862, *note inspect.stack(): 863.
     and *note inspect.trace(): 864.  Patch by Pablo Galindo.

   - gh-69093(67): Add indexing and slicing support to *note
     sqlite3.Blob: 893.  Patch by Aviv Palivoda and Erlend E. Aasland.

   - gh-69093(68): Add *note context manager: 1e1. support to *note
     sqlite3.Blob: 893.  Patch by Aviv Palivoda and Erlend E. Aasland.

   - gh-91217(69): Deprecate nntplib.

   - gh-91217(70): Deprecate msilib.

   - gh-91404(71): Improve the performance of *note re: be. matching by
     using computed gotos (or «threaded code») on supported platforms
     and removing expensive pointer indirections.

   - gh-91217(72): Deprecate the imghdr module.

   - gh-91217(73): Deprecate the crypt module.

   - gh-91276(74): Make space for longer opcodes in *note dis: 3c.
     output.

   - bpo-47000(75): Make ‘TextIOWrapper’ uses locale encoding when
     ‘encoding="locale"’ is specified even in UTF-8 mode.

   - gh-91230(76): *note warnings.catch_warnings(): 179. now accepts
     arguments for *note warnings.simplefilter(): 8d1, providing a more
     concise way to locally ignore warnings or convert them to errors.

   - gh-91217(77): Deprecate the chunk module.

   - gh-91498(78): Add the ‘TCP_CONNECTION_INFO’ option (available on
     macOS) to *note socket: d1.

   - bpo-47260(79): Fix ‘os.closerange()’ potentially being a no-op in a
     Linux seccomp sandbox.

   - bpo-47087(80): Implement ‘typing.Required’ and ‘typing.NotRequired’
     ( PEP 655(81)).  Patch by David Foster and Jelle Zijlstra.

   - bpo-47061(82): Deprecate cgi and cgitb.

   - bpo-47061(83): Deprecate audioop.

   - bpo-47000(84): Add *note locale.getencoding(): 329. to get the
     current locale encoding.  It is similar to
     ‘locale.getpreferredencoding(False)’ but ignores the *note Python
     UTF-8 Mode: 867.

   - bpo-42012(85): Add *note wsgiref.types: 122, containing
     WSGI-specific types for static type checking.

   - bpo-47227(86): Suppress expression chaining for more *note re: be.
     parsing errors.

   - bpo-47211(87): Remove undocumented and never working function
     ‘re.template()’ and flag ‘re.TEMPLATE’.  This was later reverted in
     3.11.0b2 and deprecated instead.

   - bpo-47135(88): *note decimal.localcontext(): 158e. now accepts
     context attributes via keyword arguments

   - bpo-43323(89): Fix errors in the *note email: 3f. module if the
     charset itself contains undecodable/unencodable characters.

   - bpo-46841(90): Disassembly of quickened code.

   - bpo-46681(91): Forward gzip.compress() compresslevel to zlib.

   - bpo-45100(92): Add *note typing.get_overloads(): 8be. and *note
     typing.clear_overloads(): 8bf.  Patch by Jelle Zijlstra.

   - bpo-44807(93): *note typing.Protocol: 56b. no longer silently
     replaces ‘__init__()’ methods defined on subclasses.  Patch by
     Adrian Garcia Badaracco.

   - bpo-46787(94): Fix *note concurrent.futures.ProcessPoolExecutor:
     1d6. exception memory leak

   - bpo-46720(95): Add support for path-like objects to *note
     multiprocessing.set_executable(): 1b78. for Windows to be on a par
     with Unix-like systems.  Patch by Géry Ogam.

   - bpo-46696(96): Add ‘SO_INCOMING_CPU’ constant to *note socket: d1.

   - bpo-46053(97): Fix OSS audio support on NetBSD.

   - bpo-45639(98): ‘image/avif’ and ‘image/webp’ were added to *note
     mimetypes: 93.

   - bpo-46285(99): Add command-line option ‘-p’/‘--protocol’ to module
     *note http.server: 76. which specifies the HTTP version to which
     the server is conformant (HTTP/1.1 conformant servers can now be
     run from the command-line interface of module *note http.server:
     76.).  Patch by Géry Ogam.

   - bpo-44791(100): Accept ellipsis as the last argument of *note
     typing.Concatenate: 9c9.

   - bpo-46547(101): Remove variables leaking into ‘pydoc.Helper’ class
     namespace.

   - bpo-46415(102): Fix ipaddress.ip_{address,interface,network}
     raising TypeError instead of ValueError if given invalid tuple as
     address parameter.

   - bpo-46075(103): ‘CookieJar’ with ‘DefaultCookiePolicy’ now can
     process cookies from localhost with domain=localhost explicitly
     specified in Set-Cookie header.

   - bpo-45995(104): Add a «z» option to the string formatting
     specification that coerces negative zero floating-point values to
     positive zero after rounding to the format precision.  Contributed
     by John Belmonte.

   - bpo-26175(105): Fully implement the *note io.BufferedIOBase: 8a4.
     or *note io.TextIOBase: 8a5. interface for *note
     tempfile.SpooledTemporaryFile: 8a3. objects.  This lets them work
     correctly with higher-level layers (like compression modules).
     Patch by Carey Metcalfe.

   - bpo-45138(106): Fix a regression in the *note sqlite3: d4. trace
     callback where bound parameters were not expanded in the passed
     statement string.  The regression was introduced in Python 3.10 by
     bpo-40318(107).  Patch by Erlend E. Aasland.

   - bpo-44863(108): Allow *note TypedDict: 332. subclasses to also
     include *note Generic: 179e. as a base class in class based syntax.
     Thereby allowing the user to define a generic ‘TypedDict’, just
     like a user-defined generic but with ‘TypedDict’ semantics.

   - bpo-44587(109): Fix BooleanOptionalAction to not automatically add
     a default string.  If a default string is desired, use a formatter
     to add it.

   - bpo-43827(110): All positional-or-keyword parameters to
     ‘ABCMeta.__new__’ are now positional-only to avoid conflicts with
     keyword arguments to be passed to ‘__init_subclass__()’.

   - bpo-43218(111): Prevent creation of a venv whose path contains the
     PATH separator.  This could affect the usage of the activate
     script.  Patch by Dustin Rodrigues.

   - bpo-38435(112): Add a ‘process_group’ parameter to *note
     subprocess.Popen: 4b8. to help move more things off of the unsafe
     ‘preexec_fn’ parameter.

   - bpo-42066(113): Fix cookies getting sorted in
     ‘CookieJar.__iter__()’ which is an extra behavior and not mentioned
     in RFC 2965 or Netscape cookie protocol.  Now the cookies in
     ‘CookieJar’ follows the order of the ‘Set-Cookie’ header.  Patch by
     Iman Kermani.

   - bpo-40617(114): Add *note create_window_function(): 891. to *note
     sqlite3.Connection: 54e. for creating aggregate window functions.
     Patch by Erlend E. Aasland.

   - bpo-40676(115): Convert *note csv: 2d. to use Argument Clinic for
     *note csv.field_size_limit(): 1b79, *note csv.get_dialect(): 1b7a,
     *note csv.unregister_dialect(): 1b7b. and *note
     csv.list_dialects(): 1b7c.

   - bpo-39716(116): Raise an ‘ArgumentError’ when the same subparser
     name is added twice to an ‘argparse.ArgumentParser’.  This is
     consistent with the (default) behavior when the same option string
     is added twice to an ‘ArgumentParser’.

   - bpo-36073(117): Raise *note ProgrammingError: 305. instead of
     segfaulting on recursive usage of cursors in *note sqlite3: d4.
     converters.  Patch by Sergey Fedoseev.

   - bpo-34975(118): Adds a ‘start_tls()’ method to ‘StreamWriter’,
     which upgrades the connection with TLS using the given *note
     SSLContext: 357.

   - bpo-22276(119): *note Path: 266. methods *note glob(): 538. and
     *note rglob(): 539. return only directories if 'pattern' ends with
     a pathname components separator (‘/’ or *note sep: 87b.).  Patch by
     Eisuke Kawashima.

   - bpo-24905(120): Add *note blobopen(): 892. to *note
     sqlite3.Connection: 54e.  *note sqlite3.Blob: 893. allows
     incremental I/O operations on blobs.  Patch by Aviv Palivoda and
     Erlend E. Aasland.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/87901

   (2) https://github.com/python/cpython/issues/90997

   (3) https://github.com/python/cpython/issues/92332

   (4) https://github.com/python/cpython/issues/78157

   (5) https://github.com/python/cpython/issues/92356

   (6) https://github.com/python/cpython/issues/90997

   (7) https://github.com/python/cpython/issues/92301

   (8) https://github.com/python/cpython/issues/67248

   (9) https://github.com/python/cpython/issues/92210

   (10) https://github.com/python/cpython/issues/80010

   (11) https://github.com/python/cpython/issues/92118

   (12) https://github.com/python/cpython/issues/90887

   (13) https://github.com/python/cpython/issues/91215

   (14) https://github.com/python/cpython/issues/85984

   (15) https://github.com/python/cpython/issues/92128

   (16) https://github.com/python/cpython/issues/92049

   (17) https://github.com/python/cpython/issues/92062

   (18) https://github.com/python/cpython/issues/87390

   (19) https://github.com/python/cpython/issues/88089

   (20) https://github.com/python/cpython/issues/91996

   (21) https://github.com/python/cpython/issues/91984

   (22) https://github.com/python/cpython/issues/91952

   (23) https://github.com/python/cpython/issues/91954

   (24) https://bugs.python.org/issue?@action=redirect&bpo=47029

   (25) https://github.com/python/cpython/issues/91928

   (26) https://github.com/python/cpython/issues/68966

   (27) https://peps.python.org/pep-0594/

   (28) https://github.com/python/cpython/issues/91401

   (29) https://github.com/python/cpython/issues/64783

   (30) https://github.com/python/cpython/issues/91910

   (31) https://github.com/python/cpython/issues/91860

   (32) https://peps.python.org/pep-0681/

   (33) https://github.com/python/cpython/issues/91832

   (34) https://github.com/python/cpython/issues/91827

   (35) https://github.com/python/cpython/issues/84461

   (36) https://github.com/python/cpython/issues/91821

   (37) https://github.com/python/cpython/issues/91217

   (38) https://github.com/python/cpython/issues/91217

   (39) https://github.com/python/cpython/issues/91760

   (40) https://github.com/python/cpython/issues/84461

   (41) https://github.com/python/cpython/issues/90623

   (42) https://github.com/python/cpython/issues/91734

   (43) https://github.com/python/cpython/issues/90633

   (44) https://github.com/python/cpython/issues/91700

   (45) https://github.com/python/cpython/issues/91231

   (46) https://github.com/python/cpython/issues/91621

   (47) https://github.com/python/cpython/issues/90568

   (48) https://github.com/python/cpython/issues/91670

   (49) https://github.com/python/cpython/issues/91217

   (50) https://github.com/python/cpython/issues/91217

   (51) https://github.com/python/cpython/issues/91217

   (52) https://github.com/python/cpython/issues/91217

   (53) https://github.com/python/cpython/issues/91616

   (54) https://github.com/python/cpython/issues/91217

   (55) https://github.com/python/cpython/issues/91217

   (56) https://bugs.python.org/issue?@action=redirect&bpo=47256

   (57) https://github.com/python/cpython/issues/91217

   (58) https://github.com/python/cpython/issues/91595

   (59) https://github.com/python/cpython/issues/74166

   (60) https://github.com/python/cpython/issues/91487

   (61) https://github.com/python/cpython/issues/91575

   (62) https://github.com/python/cpython/issues/90622

   (63) https://github.com/python/cpython/issues/89022

   (64) https://github.com/python/cpython/issues/91526

   (65) https://github.com/python/cpython/issues/88116

   (66) https://peps.python.org/pep-0657/

   (67) https://github.com/python/cpython/issues/69093

   (68) https://github.com/python/cpython/issues/69093

   (69) https://github.com/python/cpython/issues/91217

   (70) https://github.com/python/cpython/issues/91217

   (71) https://github.com/python/cpython/issues/91404

   (72) https://github.com/python/cpython/issues/91217

   (73) https://github.com/python/cpython/issues/91217

   (74) https://github.com/python/cpython/issues/91276

   (75) https://bugs.python.org/issue?@action=redirect&bpo=47000

   (76) https://github.com/python/cpython/issues/91230

   (77) https://github.com/python/cpython/issues/91217

   (78) https://github.com/python/cpython/issues/91498

   (79) https://bugs.python.org/issue?@action=redirect&bpo=47260

   (80) https://bugs.python.org/issue?@action=redirect&bpo=47087

   (81) https://peps.python.org/pep-0655/

   (82) https://bugs.python.org/issue?@action=redirect&bpo=47061

   (83) https://bugs.python.org/issue?@action=redirect&bpo=47061

   (84) https://bugs.python.org/issue?@action=redirect&bpo=47000

   (85) https://bugs.python.org/issue?@action=redirect&bpo=42012

   (86) https://bugs.python.org/issue?@action=redirect&bpo=47227

   (87) https://bugs.python.org/issue?@action=redirect&bpo=47211

   (88) https://bugs.python.org/issue?@action=redirect&bpo=47135

   (89) https://bugs.python.org/issue?@action=redirect&bpo=43323

   (90) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (91) https://bugs.python.org/issue?@action=redirect&bpo=46681

   (92) https://bugs.python.org/issue?@action=redirect&bpo=45100

   (93) https://bugs.python.org/issue?@action=redirect&bpo=44807

   (94) https://bugs.python.org/issue?@action=redirect&bpo=46787

   (95) https://bugs.python.org/issue?@action=redirect&bpo=46720

   (96) https://bugs.python.org/issue?@action=redirect&bpo=46696

   (97) https://bugs.python.org/issue?@action=redirect&bpo=46053

   (98) https://bugs.python.org/issue?@action=redirect&bpo=45639

   (99) https://bugs.python.org/issue?@action=redirect&bpo=46285

   (100) https://bugs.python.org/issue?@action=redirect&bpo=44791

   (101) https://bugs.python.org/issue?@action=redirect&bpo=46547

   (102) https://bugs.python.org/issue?@action=redirect&bpo=46415

   (103) https://bugs.python.org/issue?@action=redirect&bpo=46075

   (104) https://bugs.python.org/issue?@action=redirect&bpo=45995

   (105) https://bugs.python.org/issue?@action=redirect&bpo=26175

   (106) https://bugs.python.org/issue?@action=redirect&bpo=45138

   (107) https://bugs.python.org/issue?@action=redirect&bpo=40318

   (108) https://bugs.python.org/issue?@action=redirect&bpo=44863

   (109) https://bugs.python.org/issue?@action=redirect&bpo=44587

   (110) https://bugs.python.org/issue?@action=redirect&bpo=43827

   (111) https://bugs.python.org/issue?@action=redirect&bpo=43218

   (112) https://bugs.python.org/issue?@action=redirect&bpo=38435

   (113) https://bugs.python.org/issue?@action=redirect&bpo=42066

   (114) https://bugs.python.org/issue?@action=redirect&bpo=40617

   (115) https://bugs.python.org/issue?@action=redirect&bpo=40676

   (116) https://bugs.python.org/issue?@action=redirect&bpo=39716

   (117) https://bugs.python.org/issue?@action=redirect&bpo=36073

   (118) https://bugs.python.org/issue?@action=redirect&bpo=34975

   (119) https://bugs.python.org/issue?@action=redirect&bpo=22276

   (120) https://bugs.python.org/issue?@action=redirect&bpo=24905


File: python.info,  Node: Documentation<28>,  Next: Tests<28>,  Prev: Library<88>,  Up: Python 3 11 0 beta 1

1.24.34.8 Documentation
.......................

   - gh-91888(1): Add a new ‘gh’ role to the documentation to link to
     GitHub issues.

   - gh-91783(2): Document security issues concerning the use of the
     function *note shutil.unpack_archive(): 697.

   - gh-91547(3): Remove «Undocumented modules» page.

   - gh-91298(4): In ‘importlib.resources.abc’, refined the
     documentation of the Traversable Protocol, applying changes from
     importlib_resources 5.7.1.

   - bpo-44347(5): Clarify the meaning of 'dirs_exist_ok', a kwarg of
     *note shutil.copytree(): c20.

   - bpo-36329(6): Remove “make -C Doc serve” in favour of “make -C Doc
     htmlview”

   - bpo-47189(7): Add a What’s New in Python 3.11 entry for the Faster
     CPython project.  Documentation by Ken Jin and Kumar Aditya.

   - bpo-38668(8): Update the introduction to documentation for *note
     os.path: a6. to remove warnings that became irrelevant after the
     implementations of PEP 383(9) and PEP 529(10).

   - bpo-47115(11): The documentation now lists which members of C
     structs are part of the *note Limited API/Stable ABI: 776.

   - bpo-46962(12): All docstrings in code snippets are now wrapped into
     *note PyDoc_STR: 1b7e. to follow the guideline of PEP 7’s
     Documentation Strings paragraph(13).  Patch by Oleg Iarygin.

   - bpo-26792(14): Improve the docstrings of *note runpy.run_module():
     1b7f. and *note runpy.run_path(): 4a5.  Original patch by Andrew
     Brezovsky.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91888

   (2) https://github.com/python/cpython/issues/91783

   (3) https://github.com/python/cpython/issues/91547

   (4) https://github.com/python/cpython/issues/91298

   (5) https://bugs.python.org/issue?@action=redirect&bpo=44347

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36329

   (7) https://bugs.python.org/issue?@action=redirect&bpo=47189

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38668

   (9) https://peps.python.org/pep-0383/

   (10) https://peps.python.org/pep-0529/

   (11) https://bugs.python.org/issue?@action=redirect&bpo=47115

   (12) https://bugs.python.org/issue?@action=redirect&bpo=46962

   (13) https://peps.python.org/pep-0007/#documentation-strings

   (14) https://bugs.python.org/issue?@action=redirect&bpo=26792


File: python.info,  Node: Tests<28>,  Next: Build<34>,  Prev: Documentation<28>,  Up: Python 3 11 0 beta 1

1.24.34.9 Tests
...............

   - gh-92169(1): Use ‘warnings_helper.import_deprecated()’ to import
     deprecated modules uniformly in tests.  Patch by Hugo van Kemenade.

   - gh-84461(2): When multiprocessing is enabled, libregrtest can now
     use a Python executable other than ‘sys.executable’ via the
     ‘--python’ flag.

   - gh-91904(3): Fix initialization of ‘PYTHONREGRTEST_UNICODE_GUARD’
     which prevented running regression tests on non-UTF-8 locale.

   - gh-91752(4): Added @requires_zlib to
     test.test_tools.test_freeze.TestFreeze.

   - gh-91607(5): Fix ‘test_concurrent_futures’ to test the correct
     multiprocessing start method context in several cases where the
     test logic mixed this up.

   - bpo-40280(6): Threading tests are now skipped on WASM targets
     without pthread support.

   - bpo-47109(7): Test for ‘ctypes.macholib.dyld’,
     ‘ctypes.macholib.dylib’, and ‘ctypes.macholib.framework’ are
     brought from manual pre-*note unittest: 10c. times to ‘ctypes.test’
     location and structure.  Patch by Oleg Iarygin.

   - bpo-29890(8): Add tests for *note ipaddress.IPv4Interface: 1b81.
     and *note ipaddress.IPv6Interface: 1b82. construction with tuple
     arguments.  Original patch and tests by louisom.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/92169

   (2) https://github.com/python/cpython/issues/84461

   (3) https://github.com/python/cpython/issues/91904

   (4) https://github.com/python/cpython/issues/91752

   (5) https://github.com/python/cpython/issues/91607

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (7) https://bugs.python.org/issue?@action=redirect&bpo=47109

   (8) https://bugs.python.org/issue?@action=redirect&bpo=29890


File: python.info,  Node: Build<34>,  Next: Windows<29>,  Prev: Tests<28>,  Up: Python 3 11 0 beta 1

1.24.34.10 Build
................

   - gh-89452(1): gdbm-compat is now preferred over ndbm if both are
     available on the system.  This allows avoiding the problematic
     ndbm.h on macOS.

   - gh-91731(2): Python is now built with ‘-std=c11’ compiler option,
     rather than ‘-std=c99’.  Patch by Victor Stinner.

   - bpo-47152(3): Add script and make target for generating
     ‘sre_constants.h’.

   - bpo-47103(4): Windows ‘PGInstrument’ builds now copy a required DLL
     into the output directory, making it easier to run the profile
     stage of a PGO build.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89452

   (2) https://github.com/python/cpython/issues/91731

   (3) https://bugs.python.org/issue?@action=redirect&bpo=47152

   (4) https://bugs.python.org/issue?@action=redirect&bpo=47103


File: python.info,  Node: Windows<29>,  Next: macOS<20>,  Prev: Build<34>,  Up: Python 3 11 0 beta 1

1.24.34.11 Windows
..................

   - bpo-46907(1): Update Windows installer to use SQLite 3.38.3.

   - bpo-47239(2): Fixed –list and –list-paths output for *note Python
     install manager: 7db. when used in an active virtual environment.

   - bpo-46907(3): Update Windows installer to use SQLite 3.38.2.

   - bpo-46785(4): Fix race condition between *note os.stat(): 26d. and
     unlinking a file on Windows, by using errors codes returned by
     ‘FindFirstFileW()’ when appropriate in ‘win32_xstat_impl’.

   - bpo-40859(5): Update Windows build to use xz-5.2.5

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46907

   (2) https://bugs.python.org/issue?@action=redirect&bpo=47239

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46907

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46785

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40859


File: python.info,  Node: macOS<20>,  Next: Tools/Demos<25>,  Prev: Windows<29>,  Up: Python 3 11 0 beta 1

1.24.34.12 macOS
................

   - bpo-46907(1): Update macOS installer to SQLite 3.38.4.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46907


File: python.info,  Node: Tools/Demos<25>,  Next: C API<30>,  Prev: macOS<20>,  Up: Python 3 11 0 beta 1

1.24.34.13 Tools/Demos
......................

   - gh-91583(1): Fix regression in the code generated by Argument
     Clinic for functions with the ‘defining_class’ parameter.

   - gh-91575(2): Add script ‘Tools/scripts/generate_re_casefix.py’ and
     the make target ‘regen-re’ for generating additional data for
     case-insensitive matching according to the current Unicode version.

   - gh-91551(3): Remove the ancient Pynche color editor.  It has moved
     to ‘https://gitlab.com/warsaw/pynche’

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91583

   (2) https://github.com/python/cpython/issues/91575

   (3) https://github.com/python/cpython/issues/91551


File: python.info,  Node: C API<30>,  Prev: Tools/Demos<25>,  Up: Python 3 11 0 beta 1

1.24.34.14 C API
................

   - gh-88279(1): Deprecate the C functions: ‘PySys_SetArgv()’,
     ‘PySys_SetArgvEx()’, ‘PySys_SetPath()’.  Patch by Victor Stinner.

   - gh-92154(2): Added the *note PyCode_GetCode(): 97d. function.  This
     function does the equivalent of the Python code
     ‘getattr(code_object, 'co_code')’.

   - gh-92173(3): Fix the ‘closure’ argument to *note
     PyEval_EvalCodeEx(): 1ac2.

   - gh-91320(4): Fix C++ compiler warnings about «old-style cast» (‘g++
     -Wold-style-cast’) in the Python C API. Use C++
     ‘reinterpret_cast<>’ and ‘static_cast<>’ casts when the Python C
     API is used in C++.  Patch by Victor Stinner.

   - gh-80527(5): Mark functions as deprecated by PEP 623(6):
     ‘PyUnicode_AS_DATA()’, ‘PyUnicode_AS_UNICODE()’,
     ‘PyUnicode_GET_DATA_SIZE()’, ‘PyUnicode_GET_SIZE()’.  Patch by
     Victor Stinner.

   - gh-91768(7): *note Py_REFCNT(): 2cf, *note Py_TYPE(): 3c9, *note
     Py_SIZE(): 986. and *note Py_IS_TYPE(): 1b88. functions argument
     type is now ‘PyObject*’, rather than ‘const PyObject*’.  Patch by
     Victor Stinner.

   - gh-91020(8): Add ‘PyBytes_Type.tp_alloc’ to initialize
     ‘PyBytesObject.ob_shash’ for bytes subclasses.

   - bpo-40421(9): Add ‘PyFrame_GetLasti’ C-API function to access frame
     object’s ‘f_lasti’ attribute safely from C code.

   - bpo-35134(10): Remove the ‘Include/code.h’ header file.  C
     extensions should only include the main ‘<Python.h>’ header file.
     Patch by Victor Stinner.

   - bpo-47169(11): *note PyOS_CheckStack(): 1b89. is now exported in
     the Stable ABI on Windows.

   - bpo-47169(12): *note PyThread_get_thread_native_id(): 1b8a. is
     excluded from the stable ABI on platforms where it doesn’t exist
     (like Solaris).

   - bpo-46343(13): Added *note PyErr_GetHandledException(): 974. and
     *note PyErr_SetHandledException(): 975. as simpler alternatives to
     *note PyErr_GetExcInfo(): 977. and *note PyErr_SetExcInfo(): 976.

     They are included in the stable ABI.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/88279

   (2) https://github.com/python/cpython/issues/92154

   (3) https://github.com/python/cpython/issues/92173

   (4) https://github.com/python/cpython/issues/91320

   (5) https://github.com/python/cpython/issues/80527

   (6) https://peps.python.org/pep-0623/

   (7) https://github.com/python/cpython/issues/91768

   (8) https://github.com/python/cpython/issues/91020

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40421

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35134

   (11) https://bugs.python.org/issue?@action=redirect&bpo=47169

   (12) https://bugs.python.org/issue?@action=redirect&bpo=47169

   (13) https://bugs.python.org/issue?@action=redirect&bpo=46343


File: python.info,  Node: Python 3 11 0 alpha 7,  Next: Python 3 11 0 alpha 6,  Prev: Python 3 11 0 beta 1,  Up: Changelog

1.24.35 Python 3.11.0 alpha 7
-----------------------------

'Release date: 2022-04-05'

* Menu:

* Core and Builtins: Core and Builtins<86>.
* Library: Library<89>.
* Core and Builtins: Core and Builtins<87>.
* Library: Library<90>.
* Core and Builtins: Core and Builtins<88>.
* Library: Library<91>.
* Documentation: Documentation<29>.
* Tests: Tests<29>.
* Build: Build<35>.
* Windows: Windows<30>.
* macOS: macOS<21>.
* Tools/Demos: Tools/Demos<26>.
* C API: C API<31>.


File: python.info,  Node: Core and Builtins<86>,  Next: Library<89>,  Up: Python 3 11 0 alpha 7

1.24.35.1 Core and Builtins
...........................

   - bpo-47212(1): Raise *note IndentationError: 9ad. instead of *note
     SyntaxError: 18e. for a bare ‘except’ with no following indent.
     Improve *note SyntaxError: 18e. locations for an un-parenthesized
     generator used as arguments.  Patch by Matthieu Dartiailh.

   - bpo-47186(2): Replace ‘JUMP_IF_NOT_EG_MATCH’ by *note
     CHECK_EG_MATCH: 912. + jump.

   - bpo-47176(3): Emscripten builds cannot handle signals in the usual
     way due to platform limitations.  Python can now handle signals.
     To use, set Module.Py_EmscriptenSignalBuffer to be a single byte
     SharedArrayBuffer and set Py_EMSCRIPTEN_SIGNAL_HANDLING to 1.
     Writing a number into the SharedArrayBuffer will cause the
     corresponding signal to be raised into the Python thread.

   - bpo-47186(4): Replace ‘JUMP_IF_NOT_EXC_MATCH’ by *note
     CHECK_EXC_MATCH: 91a. + jump.

   - bpo-47120(5): Replace the absolute jump opcode *note
     JUMP_NO_INTERRUPT: 1b8d. by the relative *note
     JUMP_BACKWARD_NO_INTERRUPT: 90f.

   - bpo-46841(6): Avoid unnecessary allocations when comparing code
     objects.

   - bpo-47182(7): Fix a crash when using a named unicode character like
     ‘"\N{digit nine}"’ after the main interpreter has been initialized
     a second time.

   - bpo-47162(8): WebAssembly cannot deal with bad function pointer
     casts (different count or types of arguments).  Python can now use
     call trampolines to mitigate the problem.  Define
     ‘PY_CALL_TRAMPOLINE’ to enable call trampolines.

   - bpo-46775(9): Some Windows system error codes(>= 10000) are now
     mapped into the correct errno and may now raise a subclass of *note
     OSError: 2c0.  Patch by Donghee Na.

   - bpo-47129(10): Improve error messages in f-string syntax errors
     concerning empty expressions.

   - bpo-47117(11): Fix a crash if we fail to decode characters in
     interactive mode if the tokenizer buffers are uninitialized.  Patch
     by Pablo Galindo.

   - bpo-47127(12): Speed up calls to c functions with keyword arguments
     by 25% with specialization.  Patch by Kumar Aditya.

   - bpo-47120(13): Replaced ‘JUMP_ABSOLUTE’ by the relative jump *note
     JUMP_BACKWARD: 91b.

   - bpo-42197(14): ‘PyFrame_FastToLocalsWithError()’ and
     ‘PyFrame_LocalsToFast()’ are no longer called during profiling nor
     tracing.  C code can access the ‘f_locals’ attribute of *note
     PyFrameObject: 98d. by calling *note PyFrame_GetLocals(): 661.

   - bpo-47070(15): Improve performance of ‘array_inplace_repeat’ by
     reducing the number of invocations of ‘memcpy’.  Refactor the
     ‘repeat’ and inplace ‘repeat’ methods of ‘array’, ‘bytes’,
     ‘bytearray’ and ‘unicodeobject’ to use the common
     ‘_PyBytes_Repeat’.

   - bpo-47053(16): Reduce de-optimization in the specialized
     ‘BINARY_OP_INPLACE_ADD_UNICODE’ opcode.

   - bpo-47045(17): Remove the ‘f_state’ field from the
     _PyInterpreterFrame struct.  Add the ‘owner’ field to the
     _PyInterpreterFrame struct to make ownership explicit to simplify
     clearing and deallocing frames and generators.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=47212

   (2) https://bugs.python.org/issue?@action=redirect&bpo=47186

   (3) https://bugs.python.org/issue?@action=redirect&bpo=47176

   (4) https://bugs.python.org/issue?@action=redirect&bpo=47186

   (5) https://bugs.python.org/issue?@action=redirect&bpo=47120

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (7) https://bugs.python.org/issue?@action=redirect&bpo=47182

   (8) https://bugs.python.org/issue?@action=redirect&bpo=47162

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46775

   (10) https://bugs.python.org/issue?@action=redirect&bpo=47129

   (11) https://bugs.python.org/issue?@action=redirect&bpo=47117

   (12) https://bugs.python.org/issue?@action=redirect&bpo=47127

   (13) https://bugs.python.org/issue?@action=redirect&bpo=47120

   (14) https://bugs.python.org/issue?@action=redirect&bpo=42197

   (15) https://bugs.python.org/issue?@action=redirect&bpo=47070

   (16) https://bugs.python.org/issue?@action=redirect&bpo=47053

   (17) https://bugs.python.org/issue?@action=redirect&bpo=47045


File: python.info,  Node: Library<89>,  Next: Core and Builtins<87>,  Prev: Core and Builtins<86>,  Up: Python 3 11 0 alpha 7

1.24.35.2 Library
.................

   - bpo-46968(1): Check for the existence of the «sys/auxv.h» header in
     *note faulthandler: 5c. to avoid compilation problems in systems
     where this header doesn’t exist.  Patch by Pablo Galindo

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46968


File: python.info,  Node: Core and Builtins<87>,  Next: Library<90>,  Prev: Library<89>,  Up: Python 3 11 0 alpha 7

1.24.35.3 Core and Builtins
...........................

   - bpo-46329(1): Use low bit of ‘LOAD_GLOBAL’ to indicate whether to
     push a ‘NULL’ before the global.  Helps streamline the call
     sequence a bit.

   - bpo-46841(2): Quicken bytecode in-place by storing it as part of
     the corresponding ‘PyCodeObject’.

   - bpo-47012(3): Speed up iteration of *note bytes: 192. and *note
     bytearray: 344. by 30%.  Patch by Kumar Aditya.

   - bpo-47009(4): Improved the performance of *note list.append(): 8dd.
     and list comprehensions by optimizing for the common case, where no
     resize is needed.  Patch by Dennis Sweeney.

   - bpo-47005(5): Improve performance of ‘bytearray_repeat’ and
     ‘bytearray_irepeat’ by reducing the number of invocations of
     ‘memcpy’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46329

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (3) https://bugs.python.org/issue?@action=redirect&bpo=47012

   (4) https://bugs.python.org/issue?@action=redirect&bpo=47009

   (5) https://bugs.python.org/issue?@action=redirect&bpo=47005


File: python.info,  Node: Library<90>,  Next: Core and Builtins<88>,  Prev: Core and Builtins<87>,  Up: Python 3 11 0 alpha 7

1.24.35.4 Library
.................

   - bpo-46829(1): Deprecate passing a message into *note
     asyncio.Future.cancel(): 1b91. and *note asyncio.Task.cancel():
     4d4.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46829


File: python.info,  Node: Core and Builtins<88>,  Next: Library<91>,  Prev: Library<90>,  Up: Python 3 11 0 alpha 7

1.24.35.5 Core and Builtins
...........................

   - bpo-46993(1): Speed up *note bytearray: 344. creation from *note
     list: 24d. and *note tuple: 614. by 40%.  Patch by Kumar Aditya.

   - bpo-39829(2): Removed the ‘__len__()’ call when initializing a list
     and moved initializing to ‘list_extend’.  Patch by Jeremiah
     Pascual.

   - bpo-46944(3): Speed up throwing exception in generator with *note
     METH_FASTCALL: 1986. calling convention.  Patch by Kumar Aditya.

   - bpo-46841(4): Modify *note STORE_SUBSCR: 1b93. to use an inline
     cache entry (rather than its oparg) as an adaptive counter.

   - bpo-46841(5): Use inline caching for ‘PRECALL’ and *note CALL: 916,
     and remove the internal machinery for managing the (now unused)
     non-inline caches.

   - bpo-46881(6): Statically allocate and initialize the latin1
     characters.

   - bpo-46838(7): Improve syntax errors for incorrect function
     definitions.  Patch by Pablo Galindo

   - bpo-43721(8): Fix docstrings of *note getter: 19c1, *note setter:
     19c2, and *note deleter: 19c3. to clarify that they create a new
     copy of the property.

   - bpo-43224(9): Make grammar changes required for PEP 646.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46993

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39829

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46944

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46881

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46838

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43721

   (9) https://bugs.python.org/issue?@action=redirect&bpo=43224


File: python.info,  Node: Library<91>,  Next: Documentation<29>,  Prev: Core and Builtins<88>,  Up: Python 3 11 0 alpha 7

1.24.35.6 Library
.................

   - bpo-47208(1): Allow vendors to override ‘CTYPES_MAX_ARGCOUNT’.

   - bpo-23689(2): *note re: be. module: fix memory leak when a match is
     terminated by a signal or memory allocation failure.  Patch by Ma
     Lin.

   - bpo-47167(3): Allow overriding a future compliance check in *note
     asyncio.Task: 1c7.

   - bpo-47151(4): When subprocess tries to use vfork, it now falls back
     to fork if vfork returns an error.  This allows use in situations
     where vfork isn’t allowed by the OS kernel.

   - bpo-47152(5): Convert the *note re: be. module into a package.
     Deprecate modules ‘sre_compile’, ‘sre_constants’ and ‘sre_parse’.

   - bpo-4833(6): Add ‘ZipFile.mkdir()’

   - bpo-27929(7): Fix *note asyncio.loop.sock_connect(): fca. to only
     resolve names for *note socket.AF_INET: 1b95. or *note
     socket.AF_INET6: 1b96. families.  Resolution may not make sense for
     other families, like *note socket.AF_BLUETOOTH: 1b97. and *note
     socket.AF_UNIX: 1b98.

   - bpo-14265(8): Adds the fully qualified test name to unittest output

   - bpo-47061(9): Deprecate the aifc module.

   - bpo-39622(10): Handle Ctrl+C in asyncio programs to interrupt the
     main task.

   - bpo-47101(11): *note hashlib.algorithms_available: 157c. now lists
     only algorithms that are provided by activated crypto providers on
     OpenSSL 3.0.  Legacy algorithms are not listed unless the legacy
     provider has been loaded into the default OSSL context.

   - bpo-47099(12): All ‘URLError’ exception messages raised in
     ‘urllib.request.URLopener’ now contain a colon between ‘ftp error’
     and the rest of the message.  Previously, ‘open_ftp()’ missed the
     colon.  Patch by Oleg Iarygin.

   - bpo-47099(13): Exception chaining is changed from
     ‘Exception.with_traceback()’/*note sys.exc_info(): 89b. to PEP
     3134(14).  Patch by Oleg Iarygin.

   - bpo-47095(15): *note hashlib: 6c.’s internal ‘_blake2’ module now
     prefers ‘libb2’ from ‘https://www.blake2.net/’ over Python’s
     vendored copy of blake2.

   - bpo-47098(16): The Keccak Code Package for *note hashlib: 6c.’s
     internal ‘_sha3’ module has been replaced with tiny_sha3.  The
     module is used as fallback when Python is built without OpenSSL.

   - bpo-47088(17): Implement *note typing.LiteralString: 7e7, part of
     PEP 675(18).  Patch by Jelle Zijlstra.

   - bpo-42885(19): Optimize *note re.search(): 1434, *note re.split():
     5a2, *note re.findall(): 122c, *note re.finditer(): 1701. and *note
     re.sub(): 5a3. for regular expressions starting with ‘\A’ or ‘^’.

   - bpo-23691(20): Protect the *note re.finditer(): 1701. iterator from
     re-entering.

   - bpo-47067(21): Optimize calling ‘GenericAlias’ objects by using PEP
     590(22) ‘vectorcall’ and by replacing ‘PyObject_SetAttrString’ with
     ‘PyObject_SetAttr’.

   - bpo-28080(23): Add the 'metadata_encoding' parameter in the *note
     zipfile.ZipFile: 8d4. constructor and the ‘--metadata-encoding’
     option in the *note zipfile: 137. CLI to allow reading zipfiles
     using non-standard codecs to encode the filenames within the
     archive.

   - bpo-47000(24): Make *note io.text_encoding(): 1a24. returns «utf-8»
     when UTF-8 mode is enabled.

   - bpo-42369(25): Fix thread safety of ‘zipfile._SharedFile.tell()’ to
     avoid a «zipfile.BadZipFile: Bad CRC-32 for file» exception when
     reading a ‘ZipFile’ from multiple threads.

   - bpo-38256(26): Fix *note binascii.crc32(): 19f9. when it is
     compiled to use zlib’c crc32 to work properly on inputs 4+GiB in
     length instead of returning the wrong result.  The workaround prior
     to this was to always feed the function data in increments smaller
     than 4GiB or to just call the zlib module function.

     We also have *note binascii.crc32(): 19f9. release the GIL when
     computing on larger inputs as *note zlib.crc32(): 19f8. and *note
     hashlib: 6c. do.

     This also boosts performance on Windows as it now uses the zlib
     crc32 implementation for *note binascii.crc32(): 19f9. for a 2-3x
     speedup.

     That the stdlib has a crc32 API in two modules is a known
     historical oddity.  This moves us closer to a single implementation
     behind them.

   - bpo-47066(27): Global inline flags (e.g.  ‘(?i)’) can now only be
     used at the start of the regular expressions.  Using them not at
     the start of expression was deprecated since Python 3.6.

   - bpo-39394(28): A warning about inline flags not at the start of the
     regular expression now contains the position of the flag.

   - bpo-433030(29): Add support of atomic grouping (‘(?>...)’) and
     possessive quantifiers (‘*+’, ‘++’, ‘?+’, ‘{m,n}+’) in *note
     regular expressions: be.

   - bpo-47062(30): Implement *note asyncio.Runner: 2f5. context
     manager.

   - bpo-46382(31): *note dataclass(): 4e2. ‘slots=True’ now correctly
     omits slots already defined in base classes.  Patch by Arie
     Bovenberg.

   - bpo-47057(32): Use FASTCALL convention for ‘FutureIter.throw()’

   - bpo-47061(33): Deprecate the various modules listed by PEP 594(34):

     aifc, asynchat, asyncore, audioop, cgi, cgitb, chunk, crypt,
     imghdr, msilib, nntplib, nis, ossaudiodev, pipes, smtpd, sndhdr,
     spwd, sunau, telnetlib, uu, xdrlib

   - bpo-34790(35): Remove passing coroutine objects to *note
     asyncio.wait(): 6a8.

   - bpo-47039(36): Normalize ‘repr()’ of asyncio future and task
     objects.

   - bpo-2604(37): Fix bug where doctests using globals would fail when
     run multiple times.

   - bpo-45150(38): Add *note hashlib.file_digest(): 855. helper for
     efficient hashing of file object.

   - bpo-34861(39): Made cumtime the default sorting key for cProfile

   - bpo-45997(40): Fix *note asyncio.Semaphore: c6a. re-aquiring FIFO
     order.

   - bpo-47022(41): The ‘asynchat’, ‘asyncore’ and ‘smtpd’ modules have
     been deprecated since at least Python 3.6.  Their documentation and
     deprecation warnings and have now been updated to note they will
     removed in Python 3.12 ( PEP 594(42)).

   - bpo-43253(43): Fix a crash when closing transports where the
     underlying socket handle is already invalid on the Proactor event
     loop.

   - bpo-40280(44): *note select.select(): fa2. now passes ‘NULL’ to
     ‘select’ for each empty fdset.

   - bpo-47004(45): Apply bugfixes from importlib_metadata 4.11.3,
     including bugfix for EntryPoint.extras, which was returning match
     objects and not the extras strings.

   - bpo-46998(46): Allow subclassing of *note typing.Any: 8bc.  Patch
     by Shantanu Jain.

   - bpo-46995(47): Deprecate missing *note asyncio.Task.set_name():
     bd2. for third-party task implementations, schedule making it
     mandatory in Python 3.13.

   - bpo-46994(48): Accept explicit contextvars.Context in *note
     asyncio.create_task(): 1c9. and *note asyncio.loop.create_task():
     1ca.

   - bpo-46981(49): ‘typing.get_args(typing.Tuple[()])’ now returns ‘()’
     instead of ‘((),)’.

   - bpo-46968(50): Add ‘os.sysconf_names['SC_MINSIGSTKSZ']’.

   - bpo-46985(51): Upgrade pip wheel bundled with ensurepip (pip
     22.0.4)

   - bpo-46968(52): *note faulthandler: 5c.: On Linux 5.14 and newer,
     dynamically determine size of signal handler stack size CPython
     allocates using ‘getauxval(AT_MINSIGSTKSZ)’.  This changes allows
     for Python extension’s request to Linux kernel to use AMX_TILE
     instruction set on Sapphire Rapids Xeon processor to succeed,
     unblocking use of the ISA in frameworks.

   - bpo-46917(53): The *note math.nan: 874. value is now always
     available.  Patch by Victor Stinner.

   - bpo-46955(54): Expose ‘asyncio.base_events.Server’ as *note
     asyncio.Server: d0a.  Patch by Stefan Zabka.

   - bpo-23325(55): The *note signal: cb. module no longer assumes that
     *note SIG_IGN: 1b99. and *note SIG_DFL: 1b9a. are small int
     singletons.

   - bpo-46932(56): Update bundled libexpat to 2.4.7

   - bpo-46933(57): The *note pwd: b7. module is now optional.  *note
     os.path.expanduser(): c0b. returns the path when the *note pwd: b7.
     module is not available.

   - bpo-40059(58): PEP 680(59), the *note tomllib: 102. module.  Adds
     support for parsing TOML.

   - bpo-464471(60): *note asyncio.timeout(): 815. and *note
     asyncio.timeout_at(): 1b9b. context managers added.  Patch by Tin
     Tvrtković and Andrew Svetlov.

   - bpo-46805(61): Added raw datagram socket functions for asyncio:
     ‘sock_sendto()’, ‘sock_recvfrom()’ and ‘sock_recvfrom_into()’.

   - bpo-46644(62): No longer require valid typeforms to be callable.
     This allows *note typing.Annotated: b39. to wrap *note
     typing.ParamSpecArgs: 9cb. and *note dataclasses.InitVar: 1b9c.
     Patch by Gregory Beauregard.

   - bpo-46581(63): Brings ‘ParamSpec’ propagation for ‘GenericAlias’ in
     line with ‘Concatenate’ (and others).

   - bpo-45413(64): Define 'posix_venv' and 'nt_venv' *note sysconfig
     installation schemes: 449. to be used for bootstrapping new virtual
     environments.  Add 'venv' sysconfig installation scheme to get the
     appropriate one of the above.  The schemes are identical to the
     pre-existing 'posix_prefix' and 'nt' install schemes.  The *note
     venv: 117. module now uses the 'venv' scheme to create new virtual
     environments instead of hardcoding the paths depending only on the
     platform.  Downstream Python distributors customizing the
     'posix_prefix' or 'nt' install scheme in a way that is not
     compatible with the install scheme used in virtual environments are
     encouraged not to customize the 'venv' schemes.  When Python itself
     runs in a virtual environment, *note
     sysconfig.get_default_scheme(): 1b9d. and *note
     sysconfig.get_preferred_scheme(): 8a0. with ‘key="prefix"’ returns
     'venv'.

   - bpo-43224(65): Implement support for PEP 646 in typing.py.

   - bpo-43224(66): Allow unpacking types.GenericAlias objects, e.g.
     ‘*tuple[int, str]’.

   - bpo-46557(67): Warnings captured by the logging module are now
     logged without a format string to prevent systems that group logs
     by the msg argument from grouping captured warnings together.

   - bpo-41370(68): *note typing.get_type_hints(): 8c1. now supports
     evaluating strings as forward references in *note PEP 585 generic
     aliases: 8c2.

   - bpo-46607(69): Add *note DeprecationWarning: 1a3. to
     ‘LegacyInterpolation’, deprecated in the docstring since Python
     3.2.  Will be removed in Python 3.13.  Use ‘BasicInterpolation’ or
     ‘ExtendedInterpolation’ instead.

   - bpo-26120(70): *note pydoc: ba. now excludes __future__ imports
     from the module’s data items.

   - bpo-46480(71): Add *note typing.assert_type(): 8bb.  Patch by Jelle
     Zijlstra.

   - bpo-46421(72): Fix a unittest issue where if the command was
     invoked as ‘python -m unittest’ and the filename(s) began with a
     dot (.), a ‘ValueError’ is returned.

   - bpo-46245(73): Add optional parameter 'dir_fd' in *note
     shutil.rmtree(): 356.

   - bpo-22859(74): ‘unittest.TestProgram.usageExit()’ is marked as
     deprecated, to be removed in Python 3.13.

   - bpo-46170(75): Improve the error message when you try to subclass
     an instance of *note typing.NewType: ef3.

   - bpo-40296(76): Fix supporting generic aliases in *note pydoc: ba.

   - bpo-20392(77): Fix inconsistency with uppercase file extensions in
     ‘MimeTypes.guess_type()’.  Patch by Kumar Aditya.

   - bpo-46030(78): Add ‘LOCAL_CREDS’, ‘LOCAL_CREDS_PERSISTENT’ and
     ‘SCM_CREDS2’ FreeBSD constants to the socket module.

   - bpo-44439(79): Fix ‘.write()’ method of a member file in ‘ZipFile’,
     when the input data is an object that supports the buffer protocol,
     the file length may be wrong.

   - bpo-45171(80): Fix handling of the ‘stacklevel’ argument to logging
     functions in the *note logging: 8b. module so that it is consistent
     across all logging functions and, as advertised, similar to the
     ‘stacklevel’ argument used in *note warn(): 1720.

   - bpo-24959(81): Fix bug where *note unittest: 10c. sometimes drops
     frames from tracebacks of exceptions raised in tests.

   - bpo-44859(82): Raise more accurate and PEP 249(83) compatible
     exceptions in *note sqlite3: d4.

        * Raise *note InterfaceError: 88e. instead of *note
          ProgrammingError: 305. for ‘SQLITE_MISUSE’ errors.

        * Don’t overwrite *note BufferError: 177f. with *note
          ValueError: 2ec. when conversion to BLOB fails.

        * Raise *note ProgrammingError: 305. instead of *note Warning:
          1b9e. if user tries to *note execute(): 5b0. more than one SQL
          statement.

        * Raise *note ProgrammingError: 305. instead of *note
          ValueError: 2ec. if an SQL query contains null characters.

   - bpo-44493(84): Add missing terminated NUL in sockaddr_un’s length

     This was potentially observable when using non-abstract AF_UNIX
     datagram sockets to processes written in another programming
     language.

   - bpo-41930(85): Add *note serialize(): 88f. and *note deserialize():
     890. support to *note sqlite3: d4.  Patch by Erlend E. Aasland.

   - bpo-33178(86): Added *note ctypes.BigEndianUnion: 1b9f. and *note
     ctypes.LittleEndianUnion: 1ba0. classes, as originally documented
     in the library docs but not yet implemented.

   - bpo-43352(87): Add an Barrier object in synchronization primitives
     of 'asyncio' Lib in order to be consistent with Barrier from
     'threading' and 'multiprocessing' libs*

   - bpo-35859(88): *note re: be. module, fix a few bugs about capturing
     group.  In rare cases, capturing group gets an incorrect string.
     Patch by Ma Lin.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=47208

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23689

   (3) https://bugs.python.org/issue?@action=redirect&bpo=47167

   (4) https://bugs.python.org/issue?@action=redirect&bpo=47151

   (5) https://bugs.python.org/issue?@action=redirect&bpo=47152

   (6) https://bugs.python.org/issue?@action=redirect&bpo=4833

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27929

   (8) https://bugs.python.org/issue?@action=redirect&bpo=14265

   (9) https://bugs.python.org/issue?@action=redirect&bpo=47061

   (10) https://bugs.python.org/issue?@action=redirect&bpo=39622

   (11) https://bugs.python.org/issue?@action=redirect&bpo=47101

   (12) https://bugs.python.org/issue?@action=redirect&bpo=47099

   (13) https://bugs.python.org/issue?@action=redirect&bpo=47099

   (14) https://peps.python.org/pep-3134/

   (15) https://bugs.python.org/issue?@action=redirect&bpo=47095

   (16) https://bugs.python.org/issue?@action=redirect&bpo=47098

   (17) https://bugs.python.org/issue?@action=redirect&bpo=47088

   (18) https://peps.python.org/pep-0675/

   (19) https://bugs.python.org/issue?@action=redirect&bpo=42885

   (20) https://bugs.python.org/issue?@action=redirect&bpo=23691

   (21) https://bugs.python.org/issue?@action=redirect&bpo=47067

   (22) https://peps.python.org/pep-0590/

   (23) https://bugs.python.org/issue?@action=redirect&bpo=28080

   (24) https://bugs.python.org/issue?@action=redirect&bpo=47000

   (25) https://bugs.python.org/issue?@action=redirect&bpo=42369

   (26) https://bugs.python.org/issue?@action=redirect&bpo=38256

   (27) https://bugs.python.org/issue?@action=redirect&bpo=47066

   (28) https://bugs.python.org/issue?@action=redirect&bpo=39394

   (29) https://bugs.python.org/issue?@action=redirect&bpo=433030

   (30) https://bugs.python.org/issue?@action=redirect&bpo=47062

   (31) https://bugs.python.org/issue?@action=redirect&bpo=46382

   (32) https://bugs.python.org/issue?@action=redirect&bpo=47057

   (33) https://bugs.python.org/issue?@action=redirect&bpo=47061

   (34) https://peps.python.org/pep-0594/

   (35) https://bugs.python.org/issue?@action=redirect&bpo=34790

   (36) https://bugs.python.org/issue?@action=redirect&bpo=47039

   (37) https://bugs.python.org/issue?@action=redirect&bpo=2604

   (38) https://bugs.python.org/issue?@action=redirect&bpo=45150

   (39) https://bugs.python.org/issue?@action=redirect&bpo=34861

   (40) https://bugs.python.org/issue?@action=redirect&bpo=45997

   (41) https://bugs.python.org/issue?@action=redirect&bpo=47022

   (42) https://peps.python.org/pep-0594/

   (43) https://bugs.python.org/issue?@action=redirect&bpo=43253

   (44) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (45) https://bugs.python.org/issue?@action=redirect&bpo=47004

   (46) https://bugs.python.org/issue?@action=redirect&bpo=46998

   (47) https://bugs.python.org/issue?@action=redirect&bpo=46995

   (48) https://bugs.python.org/issue?@action=redirect&bpo=46994

   (49) https://bugs.python.org/issue?@action=redirect&bpo=46981

   (50) https://bugs.python.org/issue?@action=redirect&bpo=46968

   (51) https://bugs.python.org/issue?@action=redirect&bpo=46985

   (52) https://bugs.python.org/issue?@action=redirect&bpo=46968

   (53) https://bugs.python.org/issue?@action=redirect&bpo=46917

   (54) https://bugs.python.org/issue?@action=redirect&bpo=46955

   (55) https://bugs.python.org/issue?@action=redirect&bpo=23325

   (56) https://bugs.python.org/issue?@action=redirect&bpo=46932

   (57) https://bugs.python.org/issue?@action=redirect&bpo=46933

   (58) https://bugs.python.org/issue?@action=redirect&bpo=40059

   (59) https://peps.python.org/pep-0680/

   (60) https://bugs.python.org/issue?@action=redirect&bpo=464471

   (61) https://bugs.python.org/issue?@action=redirect&bpo=46805

   (62) https://bugs.python.org/issue?@action=redirect&bpo=46644

   (63) https://bugs.python.org/issue?@action=redirect&bpo=46581

   (64) https://bugs.python.org/issue?@action=redirect&bpo=45413

   (65) https://bugs.python.org/issue?@action=redirect&bpo=43224

   (66) https://bugs.python.org/issue?@action=redirect&bpo=43224

   (67) https://bugs.python.org/issue?@action=redirect&bpo=46557

   (68) https://bugs.python.org/issue?@action=redirect&bpo=41370

   (69) https://bugs.python.org/issue?@action=redirect&bpo=46607

   (70) https://bugs.python.org/issue?@action=redirect&bpo=26120

   (71) https://bugs.python.org/issue?@action=redirect&bpo=46480

   (72) https://bugs.python.org/issue?@action=redirect&bpo=46421

   (73) https://bugs.python.org/issue?@action=redirect&bpo=46245

   (74) https://bugs.python.org/issue?@action=redirect&bpo=22859

   (75) https://bugs.python.org/issue?@action=redirect&bpo=46170

   (76) https://bugs.python.org/issue?@action=redirect&bpo=40296

   (77) https://bugs.python.org/issue?@action=redirect&bpo=20392

   (78) https://bugs.python.org/issue?@action=redirect&bpo=46030

   (79) https://bugs.python.org/issue?@action=redirect&bpo=44439

   (80) https://bugs.python.org/issue?@action=redirect&bpo=45171

   (81) https://bugs.python.org/issue?@action=redirect&bpo=24959

   (82) https://bugs.python.org/issue?@action=redirect&bpo=44859

   (83) https://peps.python.org/pep-0249/

   (84) https://bugs.python.org/issue?@action=redirect&bpo=44493

   (85) https://bugs.python.org/issue?@action=redirect&bpo=41930

   (86) https://bugs.python.org/issue?@action=redirect&bpo=33178

   (87) https://bugs.python.org/issue?@action=redirect&bpo=43352

   (88) https://bugs.python.org/issue?@action=redirect&bpo=35859


File: python.info,  Node: Documentation<29>,  Next: Tests<29>,  Prev: Library<91>,  Up: Python 3 11 0 alpha 7

1.24.35.7 Documentation
.......................

   - bpo-45099(1): Document internal *note asyncio: b. API.

   - bpo-47126(2): Update PEP URLs to PEP 676(3)’s new canonical form.

   - bpo-47040(4): Clarified the old Python versions compatibility note
     of *note binascii.crc32(): 19f9. / *note zlib.adler32(): 1ba2. /
     *note zlib.crc32(): 19f8. functions.

   - bpo-46033(5): Clarify ‘for’ statement execution in its doc.

   - bpo-45790(6): Adjust inaccurate phrasing in *note Defining
     Extension Types; Tutorial: 1ba3. about the ‘ob_base’ field and the
     macros used to access its contents.

   - bpo-42340(7): Document that in some circumstances *note
     KeyboardInterrupt: bc7. may cause the code to enter an inconsistent
     state.  Provided a sample workaround to avoid it if needed.

   - bpo-41233(8): Link the errnos referenced in
     ‘Doc/library/exceptions.rst’ to their respective section in
     ‘Doc/library/errno.rst’, and vice versa.  Previously this was only
     done for EINTR and InterruptedError.  Patch by Yan «yyyyyyyan»
     Orestes.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45099

   (2) https://bugs.python.org/issue?@action=redirect&bpo=47126

   (3) https://peps.python.org/pep-0676/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=47040

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46033

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45790

   (7) https://bugs.python.org/issue?@action=redirect&bpo=42340

   (8) https://bugs.python.org/issue?@action=redirect&bpo=41233


File: python.info,  Node: Tests<29>,  Next: Build<35>,  Prev: Documentation<29>,  Up: Python 3 11 0 alpha 7

1.24.35.8 Tests
...............

   - bpo-47205(1): Skip test for *note sched_getaffinity(): 1312. and
     *note sched_setaffinity(): 1316. error case on FreeBSD.

   - bpo-46126(2): Restore “descriptions” when running tests internally.

   - bpo-47104(3): Rewrite *note asyncio.to_thread(): ae7. tests to use
     *note unittest.IsolatedAsyncioTestCase: 361.

   - bpo-40280(4): The test suite is now passing on the Emscripten
     platform.  All fork, socket, and subprocess-based tests are
     skipped.

   - bpo-47037(5): Skip ‘strftime("%4Y")’ feature test on Windows.  It
     can cause an assertion error in debug builds.

   - bpo-46587(6): Skip tests if platform’s ‘strftime’ does not support
     non-portable glibc extensions.

   - bpo-47015(7): A test case for *note os.sendfile(): d07. is
     converted from deprecated ‘asyncore’ (see PEP 594(8)) to *note
     asyncio: b.  Patch by Oleg Iarygin.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=47205

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46126

   (3) https://bugs.python.org/issue?@action=redirect&bpo=47104

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (5) https://bugs.python.org/issue?@action=redirect&bpo=47037

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46587

   (7) https://bugs.python.org/issue?@action=redirect&bpo=47015

   (8) https://peps.python.org/pep-0594/


File: python.info,  Node: Build<35>,  Next: Windows<30>,  Prev: Tests<29>,  Up: Python 3 11 0 alpha 7

1.24.35.9 Build
...............

   - bpo-40280(1): Add configure option *note
     -enable-wasm-dynamic-linking: 1ba6. to enable ‘dlopen’ and
     MAIN_MODULE / SIDE_MODULE on ‘wasm32-emscripten’.

   - bpo-46023(2): ‘makesetup’ now detects and skips all duplicated
     module definitions.  The first entry wins.

   - bpo-40280(3): Add SOABI ‘wasm32-emscripten’ for Emscripten and
     ‘wasm32-wasi’ for WASI on 32bit WASM as well as ‘wasm64’ counter
     parts.

   - bpo-47032(4): Ensure Windows install builds fail correctly with a
     non-zero exit code when part of the build fails.

   - bpo-47024(5): Update OpenSSL to 1.1.1n for macOS installers and all
     Windows builds.

   - bpo-46996(6): The *note tkinter: f6. package now requires Tcl/Tk
     version 8.5.12 or newer.

   - bpo-46973(7): Add ‘regen-configure’ make target to regenerate
     configure script with Christian’s container image
     ‘quay.io/tiran/cpython_autoconf:269’.

   - bpo-46917(8): Building Python now requires support of IEEE 754
     floating-point numbers.  Patch by Victor Stinner.

   - bpo-45774(9): ‘configure’ now verifies that all SQLite C APIs
     needed for the *note sqlite3: d4. extension module are found.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46023

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (4) https://bugs.python.org/issue?@action=redirect&bpo=47032

   (5) https://bugs.python.org/issue?@action=redirect&bpo=47024

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46996

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46973

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46917

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45774


File: python.info,  Node: Windows<30>,  Next: macOS<21>,  Prev: Build<35>,  Up: Python 3 11 0 alpha 7

1.24.35.10 Windows
..................

   - bpo-47194(1): Update ‘zlib’ to v1.2.12 to resolve CVE
     2018-25032(2).

   - bpo-47171(3): Enables installing the ‘py.exe’ launcher on Windows
     ARM64.

   - bpo-46566(4): Upgraded *note Python install manager: 7db. to
     support a new ‘-V:company/tag’ argument for full PEP 514(5) support
     and to detect ARM64 installs.  The ‘-64’ suffix on arguments is
     deprecated, but still selects any non-32-bit install.  Setting
     ‘PYLAUNCHER_ALLOW_INSTALL’ and specifying a version that is not
     installed will attempt to install the requested version from the
     Microsoft Store.

   - bpo-47086(6): The installer for Windows now includes documentation
     as loose HTML files rather than a single compiled ‘.chm’ file.

   - bpo-46907(7): Update Windows installer to use SQLite 3.38.1.

   - bpo-44549(8): Update bzip2 to 1.0.8 in Windows builds to mitigate
     CVE 2016-3189(9) and CVE 2019-12900(10).

   - bpo-46948(11): Prevent CVE 2022-26488(12) by ensuring the Add to
     PATH option in the Windows installer uses the correct path when
     being repaired.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=47194

   (2) https://www.cve.org/CVERecord?id=CVE-2018-25032

   (3) https://bugs.python.org/issue?@action=redirect&bpo=47171

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46566

   (5) https://peps.python.org/pep-0514/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=47086

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46907

   (8) https://bugs.python.org/issue?@action=redirect&bpo=44549

   (9) https://www.cve.org/CVERecord?id=CVE-2016-3189

   (10) https://www.cve.org/CVERecord?id=CVE-2019-12900

   (11) https://bugs.python.org/issue?@action=redirect&bpo=46948

   (12) https://www.cve.org/CVERecord?id=CVE-2022-26488


File: python.info,  Node: macOS<21>,  Next: Tools/Demos<26>,  Prev: Windows<30>,  Up: Python 3 11 0 alpha 7

1.24.35.11 macOS
................

   - bpo-46890(1): Fix a regression in the setting of
     ‘sys._base_executable’ in framework builds, and thereby fix a
     regression in *note venv: 117. virtual environments with such
     builds.

   - bpo-46907(2): Update macOS installer to SQLite 3.38.1.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46890

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46907


File: python.info,  Node: Tools/Demos<26>,  Next: C API<31>,  Prev: macOS<21>,  Up: Python 3 11 0 alpha 7

1.24.35.12 Tools/Demos
......................

   - bpo-40280(1): Replace Emscripten’s limited shell with Katie Bell’s
     browser-ui REPL from python-wasm project.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40280


File: python.info,  Node: C API<31>,  Prev: Tools/Demos<26>,  Up: Python 3 11 0 alpha 7

1.24.35.13 C API
................

   - bpo-40421(1): Add ‘PyFrame_GetBuiltins’, ‘PyFrame_GetGenerator’ and
     ‘PyFrame_GetGlobals’ C-API functions to access frame object
     attributes safely from C code.

   - bpo-46850(2): Move the private ‘_PyFrameEvalFunction’ type, and
     private ‘_PyInterpreterState_GetEvalFrameFunc()’ and
     ‘_PyInterpreterState_SetEvalFrameFunc()’ functions to the internal
     C API. The ‘_PyFrameEvalFunction’ callback function type now uses
     the ‘_PyInterpreterFrame’ type which is part of the internal C API.
     Patch by Victor Stinner.

   - bpo-46850(3): Move the private undocumented
     ‘_PyEval_EvalFrameDefault()’ function to the internal C API. The
     function now uses the ‘_PyInterpreterFrame’ type which is part of
     the internal C API. Patch by Victor Stinner.

   - bpo-46850(4): Remove the private undocumented function
     ‘_PyEval_CallTracing()’ from the C API. Call the public *note
     sys.call_tracing(): 1bab. function instead.  Patch by Victor
     Stinner.

   - bpo-46850(5): Remove the private undocumented function
     ‘_PyEval_GetCoroutineOriginTrackingDepth()’ from the C API. Call
     the public *note sys.get_coroutine_origin_tracking_depth(): d86.
     function instead.  Patch by Victor Stinner.

   - bpo-46850(6): Remove the following private undocumented functions
     from the C API:

        * ‘_PyEval_GetAsyncGenFirstiter()’

        * ‘_PyEval_GetAsyncGenFinalizer()’

        * ‘_PyEval_SetAsyncGenFirstiter()’

        * ‘_PyEval_SetAsyncGenFinalizer()’

     Call the public *note sys.get_asyncgen_hooks(): 1bac. and *note
     sys.set_asyncgen_hooks(): 1985. functions instead.  Patch by Victor
     Stinner.

   - bpo-46987(7): Remove private functions ‘_PySys_GetObjectId()’ and
     ‘_PySys_SetObjectId()’.  Patch by Donghee Na.

   - bpo-46906(8): Add new functions to pack and unpack C double
     (serialize and deserialize): *note PyFloat_Pack2(): 96a, *note
     PyFloat_Pack4(): 96b, *note PyFloat_Pack8(): 96c, *note
     PyFloat_Unpack2(): 96d, *note PyFloat_Unpack4(): 96e. and *note
     PyFloat_Unpack8(): 96f.  Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40421

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46850

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46850

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46850

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46850

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46850

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46987

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46906


File: python.info,  Node: Python 3 11 0 alpha 6,  Next: Python 3 11 0 alpha 5,  Prev: Python 3 11 0 alpha 7,  Up: Changelog

1.24.36 Python 3.11.0 alpha 6
-----------------------------

'Release date: 2022-03-07'

* Menu:

* Core and Builtins: Core and Builtins<89>.
* Library: Library<92>.
* Core and Builtins: Core and Builtins<90>.
* Library: Library<93>.
* Core and Builtins: Core and Builtins<91>.
* Library: Library<94>.
* Core and Builtins: Core and Builtins<92>.
* Library: Library<95>.
* Documentation: Documentation<30>.
* Tests: Tests<30>.
* Build: Build<36>.
* Windows: Windows<31>.
* IDLE: IDLE<16>.
* C API: C API<32>.


File: python.info,  Node: Core and Builtins<89>,  Next: Library<92>,  Up: Python 3 11 0 alpha 6

1.24.36.1 Core and Builtins
...........................

   - bpo-46940(1): Avoid overriding *note AttributeError: 5f0. metadata
     information for nested attribute access calls.  Patch by Pablo
     Galindo.

   - bpo-46927(2): Include the type’s name in the error message for
     subscripting non-generic types.

   - bpo-46921(3): Support vectorcall for ‘super()’.  Patch by Ken Jin.

   - bpo-46841(4): Fix incorrect handling of inline cache entries when
     specializing *note BINARY_OP: 366.

   - bpo-46841(5): Use an oparg to simplify the construction of helpful
     error messages in *note GET_AWAITABLE: 1baf.

   - bpo-46903(6): Make sure that str subclasses can be used as
     attribute names for instances with virtual dictionaries.  Fixes
     regression in 3.11alpha

   - bpo-46841(7): Add more detailed specialization failure stats for
     *note COMPARE_OP: b63. followed by *note EXTENDED_ARG: 1b06.

   - bpo-46891(8): Fix bug introduced during 3.11alpha where subclasses
     of ‘types.ModuleType’ with ‘__slots__’ were not initialized
     correctly, resulting in an interpreter crash.

   - bpo-46841(9): Use inline caching for *note LOAD_ATTR: 705,
     ‘LOAD_METHOD’, and *note STORE_ATTR: 1bb0.

   - bpo-46841(10): Use inline cache for ‘BINARY_SUBSCR’.

   - bpo-46841(11): Use inline caching for *note COMPARE_OP: b63.

   - bpo-46864(12): Deprecate ‘PyBytesObject.ob_shash’.  It will be
     removed in Python 3.13.

   - bpo-46841(13): Use inline caching for *note UNPACK_SEQUENCE: 1bb1.

   - bpo-46845(14): Reduces dict size by removing hash value from hash
     table when all inserted keys are Unicode.  For example,
     ‘sys.getsizeof(dict.fromkeys("abcdefg"))’ becomes 272 bytes from
     352 bytes on 64bit platform.

   - bpo-46841(15): Use inline cache for *note LOAD_GLOBAL: 1a42.

   - bpo-46852(16): Rename the private undocumented
     ‘float.__set_format__()’ method to ‘float.__setformat__()’ to fix a
     typo introduced in Python 3.7.  The method is only used by
     test_float.  Patch by Victor Stinner.

   - bpo-46852(17): Remove the undocumented private
     ‘float.__set_format__()’ method, previously known as
     ‘float.__setformat__()’ in Python 3.7.  Its docstring said: «You
     probably don’t want to use this function.  It exists mainly to be
     used in Python’s test suite.» Patch by Victor Stinner.

   - bpo-40116(18): Fix regression that dict.update(other) may don’t
     respect iterate order of other when other is key sharing dict.

   - bpo-46712(19): Share global string identifiers in deep-frozen
     modules.

   - bpo-46430(20): Fix memory leak in interned strings of deep-frozen
     modules.

   - bpo-46841(21): Store *note BINARY_OP: 366. caches inline using a
     new *note CACHE: 909. instruction.

   - bpo-45107(22): Specialize ‘LOAD_METHOD’ for instances with a dict.

   - bpo-44337(23): Reduce the memory usage of specialized *note
     LOAD_ATTR: 705. and *note STORE_ATTR: 1bb0. instructions.

   - bpo-46729(24): Add number of sub-exceptions to
     ‘BaseException.__str__()’.

   - bpo-45885(25): Don’t un-adapt *note COMPARE_OP: b63. when
     collecting specialization stats.

   - bpo-46329(26): Fix specialization stats gathering for ‘PRECALL’
     instructions.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46940

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46927

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46921

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46903

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46891

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (10) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (11) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (12) https://bugs.python.org/issue?@action=redirect&bpo=46864

   (13) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (14) https://bugs.python.org/issue?@action=redirect&bpo=46845

   (15) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (16) https://bugs.python.org/issue?@action=redirect&bpo=46852

   (17) https://bugs.python.org/issue?@action=redirect&bpo=46852

   (18) https://bugs.python.org/issue?@action=redirect&bpo=40116

   (19) https://bugs.python.org/issue?@action=redirect&bpo=46712

   (20) https://bugs.python.org/issue?@action=redirect&bpo=46430

   (21) https://bugs.python.org/issue?@action=redirect&bpo=46841

   (22) https://bugs.python.org/issue?@action=redirect&bpo=45107

   (23) https://bugs.python.org/issue?@action=redirect&bpo=44337

   (24) https://bugs.python.org/issue?@action=redirect&bpo=46729

   (25) https://bugs.python.org/issue?@action=redirect&bpo=45885

   (26) https://bugs.python.org/issue?@action=redirect&bpo=46329


File: python.info,  Node: Library<92>,  Next: Core and Builtins<90>,  Prev: Core and Builtins<89>,  Up: Python 3 11 0 alpha 6

1.24.36.2 Library
.................

   - bpo-46794(1): Bump up the libexpat version into 2.4.6

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46794


File: python.info,  Node: Core and Builtins<90>,  Next: Library<93>,  Prev: Library<92>,  Up: Python 3 11 0 alpha 6

1.24.36.3 Core and Builtins
...........................

   - bpo-46823(1): Implement a specialized combined opcode
     ‘LOAD_FAST__LOAD_ATTR_INSTANCE_VALUE’.  Patch by Dennis Sweeney.

   - bpo-46820(2): Fix parsing a numeric literal immediately (without
     spaces) followed by «not in» keywords, like in ‘1not in x’.  Now
     the parser only emits a warning, not a syntax error.

   - bpo-46329(3): Move ‘KW_NAMES’ before ‘PRECALL’ instruction in call
     sequence.  Change ‘operand’ of ‘CALL’ to match ‘PRECALL’ for easier
     specialization.

   - bpo-46808(4): Remove the ‘NEXT_BLOCK’ macro from compile.c, and
     make the compiler automatically generate implicit blocks when they
     are needed.

   - bpo-46329(5): Add ‘PUSH_NULL’ instruction.  This is used as a
     prefix when evaluating a callable, so that the stack has the same
     shape for methods and other calls.  ‘PRECALL_FUNCTION’ and
     ‘PRECALL_METHOD’ are merged into a single ‘PRECALL’ instruction.

     There is no change in semantics.

   - bpo-46762(6): Fix an assert failure in debug builds when a “<”,
     “>”, or “=” is the last character in an f-string that’s missing a
     closing right brace.

   - bpo-46730(7): Message of AttributeError caused by getting, setting
     or deleting a property without the corresponding function now
     mentions that the attribute is in fact a property and also
     specifies type of the class that it belongs to.

   - bpo-46724(8): Make sure that all backwards jumps use the
     ‘JUMP_ABSOLUTE’ instruction, rather than ‘JUMP_FORWARD’ with an
     argument of ‘(2**32)+offset’.

   - bpo-46732(9): Correct the docstring for the *note __bool__(): 14dd.
     method.  Patch by Jelle Zijlstra.

   - bpo-46072(10): Add more detailed specialization failure statistics
     for *note BINARY_OP: 366.

   - bpo-46707(11): Avoid potential exponential backtracking when
     producing some syntax errors involving lots of brackets.  Patch by
     Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46823

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46820

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46329

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46808

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46329

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46762

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46730

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46724

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46732

   (10) https://bugs.python.org/issue?@action=redirect&bpo=46072

   (11) https://bugs.python.org/issue?@action=redirect&bpo=46707


File: python.info,  Node: Library<93>,  Next: Core and Builtins<91>,  Prev: Core and Builtins<90>,  Up: Python 3 11 0 alpha 6

1.24.36.4 Library
.................

   - bpo-46323(1): *note ctypes: 2e. now allocates memory on the stack
     instead of on the heap to pass arguments while calling a Python
     callback function.  Patch by Donghee Na.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46323


File: python.info,  Node: Core and Builtins<91>,  Next: Library<94>,  Prev: Library<93>,  Up: Python 3 11 0 alpha 6

1.24.36.5 Core and Builtins
...........................

   - bpo-45923(1): Add a quickened form of *note RESUME: 5bb. that skips
     quickening checks.

   - bpo-46702(2): Specialize *note UNPACK_SEQUENCE: 1bb1. for *note
     tuple: 614. and *note list: 24d. unpackings.

   - bpo-46072(3): Opcode pair stats are now gathered with
     ‘--enable-pystats’.  Defining ‘DYNAMIC_EXECUTION_PROFILE’ or
     ‘DXPAIRS’ no longer has any effect.

   - bpo-46675(4): Allow more than 16 items in a split dict before it is
     combined.  The limit is now 254.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45923

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46702

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46072

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46675


File: python.info,  Node: Library<94>,  Next: Core and Builtins<92>,  Prev: Core and Builtins<91>,  Up: Python 3 11 0 alpha 6

1.24.36.6 Library
.................

   - bpo-40479(1): Add a missing call to ‘va_end()’ in
     ‘Modules/_hashopenssl.c’.

   - bpo-46323(2): Use *note PyObject_Vectorcall(): 77f. while calling
     ctypes callback function.  Patch by Donghee Na.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40479

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46323


File: python.info,  Node: Core and Builtins<92>,  Next: Library<95>,  Prev: Library<94>,  Up: Python 3 11 0 alpha 6

1.24.36.7 Core and Builtins
...........................

   - bpo-46615(1): When iterating over sets internally in ‘setobject.c’,
     acquire strong references to the resulting items from the set.
     This prevents crashes in corner-cases of various set operations
     where the set gets mutated.

   - bpo-45828(2): The bytecode compiler now attempts to apply runtime
     stack manipulations at compile-time (whenever it is feasible to do
     so).

   - bpo-30496(3): Fixed a minor portability issue in the implementation
     of *note PyLong_FromLong(): 1bb8, and added a fast path for
     single-digit integers to *note PyLong_FromLongLong(): 1bb9.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46615

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45828

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30496


File: python.info,  Node: Library<95>,  Next: Documentation<30>,  Prev: Core and Builtins<92>,  Up: Python 3 11 0 alpha 6

1.24.36.8 Library
.................

   - bpo-25707(1): Fixed a file leak in *note
     xml.etree.ElementTree.iterparse(): 57a. when the iterator is not
     exhausted.  Patch by Jacob Walls.

   - bpo-46877(2): Export *note unittest.doModuleCleanups(): 1bbb. in
     *note unittest: 10c.  Patch by Kumar Aditya.

   - bpo-46848(3): For performance, use the optimized string-searching
     implementations from *note find(): 1bbc. and *note rfind(): 1bbd.
     for ‘find()’ and ‘rfind()’.

   - bpo-46736(4): *note SimpleHTTPRequestHandler: d3a. now uses HTML5
     grammar.  Patch by Donghee Na.

   - bpo-44886(5): Inherit asyncio proactor datagram transport from
     *note asyncio.DatagramTransport: 1b0f.

   - bpo-46827(6): Support UDP sockets in *note
     asyncio.loop.sock_connect(): fca. for selector-based event loops.
     Patch by Thomas Grainger.

   - bpo-46811(7): Make test suite support Expat >=2.4.5

   - bpo-46252(8): Raise *note TypeError: 198. if *note ssl.SSLSocket:
     ae9. is passed to transport-based APIs.

   - bpo-46784(9): Fix libexpat symbols collisions with user dynamically
     loaded or statically linked libexpat in embedded Python.

   - bpo-46786(10): The HTML serialisation in xml.etree.ElementTree now
     writes ‘embed’, ‘source’, ‘track’ and ‘wbr’ as empty tags, as
     defined in HTML 5.

   - bpo-39327(11): *note shutil.rmtree(): 356. can now work with
     VirtualBox shared folders when running from the guest
     operating-system.

   - bpo-45390(12): Propagate *note asyncio.CancelledError: 4d5. message
     from inner task to outer awaiter.

   - bpo-46756(13): Fix a bug in *note
     urllib.request.HTTPPasswordMgr.find_user_password(): 1bbe. and
     *note
     urllib.request.HTTPPasswordMgrWithPriorAuth.is_authenticated():
     1bbf. which allowed to bypass authorization.  For example, access
     to URI ‘example.org/foobar’ was allowed if the user was authorized
     for URI ‘example.org/foo’.

   - bpo-46737(14): *note random.gauss(): 1bc0. and *note
     random.normalvariate(): 1bc1. now have default arguments.

   - bpo-46752(15): Add task groups to asyncio (structured concurrency,
     inspired by Trio’s nurseries).  This also introduces a change to
     task cancellation, where a cancelled task can’t be cancelled again
     until it calls .uncancel().

   - bpo-46724(16): Fix *note dis: 3c. behavior on negative jump
     offsets.

   - bpo-46333(17): The ‘__repr__()’ method of *note typing.ForwardRef:
     1bc2. now includes the ‘module’ parameter of *note
     typing.ForwardRef: 1bc2. when it is set.

   - bpo-46643(18): In *note typing.get_type_hints(): 8c1, support
     evaluating stringified ‘ParamSpecArgs’ and ‘ParamSpecKwargs’
     annotations.  Patch by Gregory Beauregard.

   - bpo-45863(19): When the *note tarfile: e4. module creates a pax
     format archive, it will put an integer representation of timestamps
     in the ustar header (if possible) for the benefit of older
     unarchivers, in addition to the existing full-precision timestamps
     in the pax extended header.

   - bpo-46066(20): Deprecate kwargs-based syntax for *note
     typing.TypedDict: 332. definitions.  It had confusing semantics
     when specifying totality, and was largely unused.  Patch by
     Jingchen Ye.

   - bpo-46676(21): Make *note typing.ParamSpec: 488. args and kwargs
     equal to themselves.  Patch by Gregory Beauregard.

   - bpo-46323(22): ‘ctypes.CFUNCTYPE()’ and ‘ctypes.WINFUNCTYPE()’ now
     fail to create the type if its ‘_argtypes_’ member contains too
     many arguments.  Previously, the error was only raised when calling
     a function.  Patch by Victor Stinner.

   - bpo-46672(23): Fix ‘NameError’ in *note asyncio.gather(): 814. when
     initial type check fails.

   - bpo-46659(24): The *note calendar.LocaleTextCalendar: 94c. and
     *note calendar.LocaleHTMLCalendar: 94d. classes now use *note
     locale.getlocale(): 327, instead of using *note
     locale.getdefaultlocale(): 326, if no locale is specified.  Patch
     by Victor Stinner.

   - bpo-46659(25): The *note locale.getdefaultlocale(): 326. function
     is deprecated and will be removed in Python 3.13.  Use *note
     locale.setlocale(): 328, *note locale.getpreferredencoding(False):
     75d. and *note locale.getlocale(): 327. functions instead.  Patch
     by Victor Stinner.

   - bpo-46655(26): In *note typing.get_type_hints(): 8c1, support
     evaluating bare stringified ‘TypeAlias’ annotations.  Patch by
     Gregory Beauregard.

   - bpo-45948(27): Fixed a discrepancy in the C implementation of the
     *note xml.etree.ElementTree: 12b. module.  Now, instantiating an
     *note xml.etree.ElementTree.XMLParser: c4b. with a ‘target=None’
     keyword provides a default *note xml.etree.ElementTree.TreeBuilder:
     c4c. target as the Python implementation does.

   - bpo-46626(28): Expose Linux’s ‘IP_BIND_ADDRESS_NO_PORT’ option in
     *note socket: d1.

   - bpo-46521(29): Fix a bug in the *note codeop: 1d. module that was
     incorrectly identifying invalid code involving string quotes as
     valid code.

   - bpo-46571(30): Improve *note typing.no_type_check(): 8c4.

     Now it does not modify external classes and functions.  We also now
     correctly mark classmethods as not to be type checked.

   - bpo-46400(31): expat: Update libexpat from 2.4.1 to 2.4.4

   - bpo-46556(32): Deprecate undocumented support for using a *note
     pathlib.Path: 266. object as a context manager.

   - bpo-46534(33): Implement PEP 673(34) *note typing.Self: 7e4.  Patch
     by James Hilton-Balfe.

   - bpo-46522(35): Make various module ‘__getattr__’ AttributeErrors
     more closely match a typical AttributeError

   - bpo-46475(36): Add *note typing.Never: 8b8. and *note
     typing.assert_never(): 8b7.  Patch by Jelle Zijlstra.

   - bpo-46333(37): The ‘__eq__()’ and ‘__hash__()’ methods of *note
     typing.ForwardRef: 1bc2. now honor the ‘module’ parameter of *note
     typing.ForwardRef: 1bc2.  Forward references from different modules
     are now differentiated.

   - bpo-46246(38): Add missing ‘__slots__’ to
     ‘importlib.metadata.DeprecatedList’.  Patch by Arie Bovenberg.

   - bpo-46232(39): The *note ssl: d5. module now handles certificates
     with bit strings in DN correctly.

   - bpo-46195(40): *note typing.get_type_hints(): 8c1. no longer adds
     ‘Optional’ to parameters with ‘None’ as a default.  This aligns to
     changes to PEP 484 in ‘https://github.com/python/peps/pull/689’

   - bpo-31369(41): Add *note RegexFlag: 840. to ‘re.__all__’ and
     documented it.  Add ‘NOFLAG’ to indicate no flags being set.

   - bpo-45898(42): *note ctypes: 2e. no longer defines ‘ffi_type_*’
     symbols in ‘cfield.c’.  The symbols have been provided by libffi
     for over a decade.

   - bpo-44953(43): Calling ‘operator.itemgetter’ objects and
     ‘operator.attrgetter’ objects is now faster due to use of the
     vectorcall calling convention.

   - bpo-44289(44): Fix an issue with *note is_tarfile(): 1bc3. method
     when using 'fileobj' argument: position in the 'fileobj' was
     advanced forward which made it unreadable with *note
     tarfile.TarFile.open(): 1bc4.

   - bpo-44011(45): Reimplement SSL/TLS support in asyncio, borrow the
     implementation from uvloop library.

   - bpo-41086(46): Make the *note configparser.ConfigParser: 4df.
     constructor raise *note TypeError: 198. if the ‘interpolation’
     parameter is not of type ‘configparser.Interpolation’

   - bpo-29418(47): Implement *note inspect.ismethodwrapper(): 85b. and
     fix *note inspect.isroutine(): 1bc5. for cases where methodwrapper
     is given.  Patch by Hakan Çelik.

   - bpo-14156(48): argparse.FileType now supports an argument of “-” in
     binary mode, returning the .buffer attribute of
     sys.stdin/sys.stdout as appropriate.  Modes including “x” and “a”
     are treated equivalently to “w” when argument is “-”.  Patch
     contributed by Josh Rosenberg

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25707

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46877

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46848

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46736

   (5) https://bugs.python.org/issue?@action=redirect&bpo=44886

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46827

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46811

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46252

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46784

   (10) https://bugs.python.org/issue?@action=redirect&bpo=46786

   (11) https://bugs.python.org/issue?@action=redirect&bpo=39327

   (12) https://bugs.python.org/issue?@action=redirect&bpo=45390

   (13) https://bugs.python.org/issue?@action=redirect&bpo=46756

   (14) https://bugs.python.org/issue?@action=redirect&bpo=46737

   (15) https://bugs.python.org/issue?@action=redirect&bpo=46752

   (16) https://bugs.python.org/issue?@action=redirect&bpo=46724

   (17) https://bugs.python.org/issue?@action=redirect&bpo=46333

   (18) https://bugs.python.org/issue?@action=redirect&bpo=46643

   (19) https://bugs.python.org/issue?@action=redirect&bpo=45863

   (20) https://bugs.python.org/issue?@action=redirect&bpo=46066

   (21) https://bugs.python.org/issue?@action=redirect&bpo=46676

   (22) https://bugs.python.org/issue?@action=redirect&bpo=46323

   (23) https://bugs.python.org/issue?@action=redirect&bpo=46672

   (24) https://bugs.python.org/issue?@action=redirect&bpo=46659

   (25) https://bugs.python.org/issue?@action=redirect&bpo=46659

   (26) https://bugs.python.org/issue?@action=redirect&bpo=46655

   (27) https://bugs.python.org/issue?@action=redirect&bpo=45948

   (28) https://bugs.python.org/issue?@action=redirect&bpo=46626

   (29) https://bugs.python.org/issue?@action=redirect&bpo=46521

   (30) https://bugs.python.org/issue?@action=redirect&bpo=46571

   (31) https://bugs.python.org/issue?@action=redirect&bpo=46400

   (32) https://bugs.python.org/issue?@action=redirect&bpo=46556

   (33) https://bugs.python.org/issue?@action=redirect&bpo=46534

   (34) https://peps.python.org/pep-0673/

   (35) https://bugs.python.org/issue?@action=redirect&bpo=46522

   (36) https://bugs.python.org/issue?@action=redirect&bpo=46475

   (37) https://bugs.python.org/issue?@action=redirect&bpo=46333

   (38) https://bugs.python.org/issue?@action=redirect&bpo=46246

   (39) https://bugs.python.org/issue?@action=redirect&bpo=46232

   (40) https://bugs.python.org/issue?@action=redirect&bpo=46195

   (41) https://bugs.python.org/issue?@action=redirect&bpo=31369

   (42) https://bugs.python.org/issue?@action=redirect&bpo=45898

   (43) https://bugs.python.org/issue?@action=redirect&bpo=44953

   (44) https://bugs.python.org/issue?@action=redirect&bpo=44289

   (45) https://bugs.python.org/issue?@action=redirect&bpo=44011

   (46) https://bugs.python.org/issue?@action=redirect&bpo=41086

   (47) https://bugs.python.org/issue?@action=redirect&bpo=29418

   (48) https://bugs.python.org/issue?@action=redirect&bpo=14156


File: python.info,  Node: Documentation<30>,  Next: Tests<30>,  Prev: Library<95>,  Up: Python 3 11 0 alpha 6

1.24.36.9 Documentation
.......................

   - bpo-42238(1): ‘Doc/tools/rstlint.py’ has moved to its own
     repository and is now packaged on PyPI as ‘sphinx-lint’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42238


File: python.info,  Node: Tests<30>,  Next: Build<36>,  Prev: Documentation<30>,  Up: Python 3 11 0 alpha 6

1.24.36.10 Tests
................

   - bpo-46913(1): Fix test_faulthandler.test_sigfpe() if Python is
     built with undefined behavior sanitizer (UBSAN): disable UBSAN on
     the faulthandler_sigfpe() function.  Patch by Victor Stinner.

   - bpo-46760(2): Remove bytecode offsets from expected values in
     test.test_dis module.  Reduces the obstacles to modifying the VM or
     compiler.

   - bpo-46708(3): Prevent default asyncio event loop policy
     modification warning after ‘test_asyncio’ execution.

   - bpo-46678(4): The function ‘make_legacy_pyc’ in
     ‘Lib/test/support/import_helper.py’ no longer fails when
     ‘PYTHONPYCACHEPREFIX’ is set to a directory on a different device
     from where tempfiles are stored.

   - bpo-46623(5): Skip test_pair() and test_speech128() of test_zlib on
     s390x since they fail if zlib uses the s390x hardware accelerator.
     Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46913

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46760

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46708

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46678

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46623


File: python.info,  Node: Build<36>,  Next: Windows<31>,  Prev: Tests<30>,  Up: Python 3 11 0 alpha 6

1.24.36.11 Build
................

   - bpo-46860(1): Respect ‘--with-suffix’ when building on
     case-insensitive file systems.

   - bpo-46656(2): Building Python now requires a C11 compiler.
     Optional C11 features are not required.  Patch by Victor Stinner.

   - bpo-46656(3): Building Python now requires support for
     floating-point Not-a-Number (NaN): remove the ‘Py_NO_NAN’ macro.
     Patch by Victor Stinner.

   - bpo-46640(4): Building Python now requires a C99 ‘<math.h>’ header
     file providing a ‘NAN’ constant, or the ‘__builtin_nan()’ built-in
     function.  Patch by Victor Stinner.

   - bpo-46608(5): Exclude marshalled-frozen data if deep-freezing to
     save 300 KB disk space.  This includes adding a new ‘is_package’
     field to *note _frozen: 97a.  Patch by Kumar Aditya.

   - bpo-40280(6): Fix wasm32-emscripten test failures and platform
     issues.  - Disable syscalls that are not supported or don’t work,
     e.g.  wait, getrusage, prlimit, mkfifo, mknod, setres[gu]id,
     setgroups.  - Use fd_count to count open fds.  - Add more checks
     for subprocess and fork.  - Add workarounds for missing
     _multiprocessing and failing socket.accept().  - Enable bzip2.  -
     Disable large file support.  - Disable signal.alarm.

   - bpo-46430(7): Intern strings in deep-frozen modules.  Patch by
     Kumar Aditya.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46860

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46656

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46656

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46640

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46608

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46430


File: python.info,  Node: Windows<31>,  Next: IDLE<16>,  Prev: Build<36>,  Up: Python 3 11 0 alpha 6

1.24.36.12 Windows
..................

   - bpo-46744(1): The default all users install directory for ARM64 is
     now under the native ‘Program Files’ folder, rather than ‘Program
     Files (Arm)’ which is intended for ARM (32-bit) files.

   - bpo-46567(2): Adds Tcl and Tk support for Windows ARM64.  This also
     adds IDLE to the installation.

   - bpo-46638(3): Ensures registry virtualization is consistently
     disabled.  For 3.10 and earlier, it remains enabled (some registry
     writes are protected), while for 3.11 and later it is disabled
     (registry modifications affect all applications).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46744

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46567

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46638


File: python.info,  Node: IDLE<16>,  Next: C API<32>,  Prev: Windows<31>,  Up: Python 3 11 0 alpha 6

1.24.36.13 IDLE
...............

   - bpo-46630(1): Make query dialogs on Windows start with a cursor in
     the entry box.

   - bpo-45447(2): Apply IDLE syntax highlighting to ‘.pyi’ files.
     Patch by Alex Waygood and Terry Jan Reedy.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46630

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45447


File: python.info,  Node: C API<32>,  Prev: IDLE<16>,  Up: Python 3 11 0 alpha 6

1.24.36.14 C API
................

   - bpo-46748(1): Python’s public headers no longer import
     ‘<stdbool.h>’, leaving code that embeds/extends Python free to
     define ‘bool’, ‘true’ and ‘false’.

   - bpo-46836(2): Move the *note PyFrameObject: 98d. type definition
     (‘struct _frame’) to the internal C API ‘pycore_frame.h’ header
     file.  Patch by Victor Stinner.

   - bpo-45459(3): Rename ‘Include/buffer.h’ header file to
     ‘Include/pybuffer.h’ to avoid conflicts with projects having an
     existing ‘buffer.h’ header file.  Patch by Victor Stinner.

   - bpo-45412(4): Remove the ‘HAVE_PY_SET_53BIT_PRECISION’ macro (moved
     to the internal C API). Patch by Victor Stinner.

   - bpo-46613(5): Added function *note PyType_GetModuleByDef(): 635,
     which allows access to module state when a method’s defining class
     is not available.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46748

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46836

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45459

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45412

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46613


File: python.info,  Node: Python 3 11 0 alpha 5,  Next: Python 3 11 0 alpha 4,  Prev: Python 3 11 0 alpha 6,  Up: Changelog

1.24.37 Python 3.11.0 alpha 5
-----------------------------

'Release date: 2022-02-03'

* Menu:

* Core and Builtins: Core and Builtins<93>.
* Library: Library<96>.
* Core and Builtins: Core and Builtins<94>.
* Library: Library<97>.
* Build: Build<37>.
* Core and Builtins: Core and Builtins<95>.
* Library: Library<98>.
* Documentation: Documentation<31>.
* Tests: Tests<31>.
* Build: Build<38>.
* Windows: Windows<32>.
* macOS: macOS<22>.
* IDLE: IDLE<17>.
* C API: C API<33>.


File: python.info,  Node: Core and Builtins<93>,  Next: Library<96>,  Up: Python 3 11 0 alpha 5

1.24.37.1 Core and Builtins
...........................

   - bpo-45773(1): Remove two invalid «peephole» optimizations from the
     bytecode compiler.

   - bpo-46564(2): Do not create frame objects when creating *note
     super: 1a6. object.  Patch by Kumar Aditya.

   - bpo-45885(3): Added more fined-grained specialization failure stats
     regarding the ‘COMPARE_OP’ bytecode.

   - bpo-44977(4): The delegation of *note int(): 19b. to ‘__trunc__()’
     is now deprecated.  Calling ‘int(a)’ when ‘type(a)’ implements
     ‘__trunc__()’ but not ‘__int__()’ or ‘__index__()’ now raises a
     *note DeprecationWarning: 1a3.

   - bpo-46458(5): Reorder code emitted by the compiler for a *note try:
     8f9.-*note except: 1ab. block so that the *note else: 17c. block’s
     code immediately follows the *note try: 8f9. body (without a jump).
     This is more optimal for the happy path.

   - bpo-46527(6): Allow passing ‘iterable’ as a keyword argument to
     *note enumerate(): 1688. again.  Patch by Jelle Zijlstra.

   - bpo-46528(7): Replace several stack manipulation instructions
     (‘DUP_TOP’, ‘DUP_TOP_TWO’, ‘ROT_TWO’, ‘ROT_THREE’, ‘ROT_FOUR’, and
     ‘ROT_N’) with new *note COPY: 918. and *note SWAP: 919.
     instructions.

   - bpo-46329(8): Use two or three bytecodes to implement most calls.

     Calls without named arguments are implemented as a sequence of two
     instructions: ‘PRECALL; CALL’.  Calls with named arguments are
     implemented as a sequence of three instructions: ‘PRECALL;
     KW_NAMES; CALL’.  There are two different ‘PRECALL’ instructions:
     ‘PRECALL_FUNTION’ and ‘PRECALL_METHOD’.  The latter pairs with
     ‘LOAD_METHOD’.

     This partition into pre-call and call allows better specialization,
     and thus better performance ultimately.

     There is no change in semantics.

   - bpo-46503(9): Fix an assert when parsing some invalid N escape
     sequences in f-strings.

   - bpo-46431(10): Improve error message on invalid calls to
     ‘BaseExceptionGroup.__new__()’.

   - bpo-46476(11): Fix memory leak in code objects generated by
     deepfreeze.  Patch by Kumar Aditya.

   - bpo-46481(12): Speed up calls to ‘weakref.ref.__call__()’ by using
     the PEP 590(13) ‘vectorcall’ calling convention.  Patch by Donghee
     Na.

   - bpo-46417(14): Fix a race condition on setting a type ‘__bases__’
     attribute: the internal function ‘add_subclass()’ now gets the
     ‘PyTypeObject.tp_subclasses’ member after calling *note
     PyWeakref_NewRef(): 1bce. which can trigger a garbage collection
     which can indirectly modify ‘PyTypeObject.tp_subclasses’.  Patch by
     Victor Stinner.

   - bpo-46417(15): ‘python -X showrefcount’ now shows the total
     reference count after clearing and destroyed the main Python
     interpreter.  Previously, it was shown before.  Patch by Victor
     Stinner.

   - bpo-43683(16): Add ASYNC_GEN_WRAP opcode to wrap the value to be
     yielded in async generators.  Removes the need to special case
     async generators in the ‘YIELD_VALUE’ instruction.

   - bpo-46407(17): Optimize some modulo operations in
     ‘Objects/longobject.c’.  Patch by Jeremiah Vivian.

   - bpo-46409(18): Add new ‘RETURN_GENERATOR’ bytecode to make
     generators.  Simplifies calling Python functions in the VM, as they
     no longer any need to special case generator functions.

     Also add ‘JUMP_NO_INTERRUPT’ bytecode that acts like
     ‘JUMP_ABSOLUTE’, but does not check for interrupts.

   - bpo-46406(19): The integer division ‘//’ implementation has been
     optimized to better let the compiler understand its constraints.
     It can be 20% faster on the amd64 platform when dividing an int by
     a value smaller than ‘2**30’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45773

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46564

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45885

   (4) https://bugs.python.org/issue?@action=redirect&bpo=44977

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46458

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46527

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46528

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46329

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46503

   (10) https://bugs.python.org/issue?@action=redirect&bpo=46431

   (11) https://bugs.python.org/issue?@action=redirect&bpo=46476

   (12) https://bugs.python.org/issue?@action=redirect&bpo=46481

   (13) https://peps.python.org/pep-0590/

   (14) https://bugs.python.org/issue?@action=redirect&bpo=46417

   (15) https://bugs.python.org/issue?@action=redirect&bpo=46417

   (16) https://bugs.python.org/issue?@action=redirect&bpo=43683

   (17) https://bugs.python.org/issue?@action=redirect&bpo=46407

   (18) https://bugs.python.org/issue?@action=redirect&bpo=46409

   (19) https://bugs.python.org/issue?@action=redirect&bpo=46406


File: python.info,  Node: Library<96>,  Next: Core and Builtins<94>,  Prev: Core and Builtins<93>,  Up: Python 3 11 0 alpha 5

1.24.37.2 Library
.................

   - bpo-46383(1): Fix invalid signature of ‘_zoneinfo’’s ‘module_free’
     function to resolve a crash on wasm32-emscripten platform.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46383


File: python.info,  Node: Core and Builtins<94>,  Next: Library<97>,  Prev: Library<96>,  Up: Python 3 11 0 alpha 5

1.24.37.3 Core and Builtins
...........................

   - bpo-46361(1): Ensure that «small» integers created by *note
     int.from_bytes(): 1bd1. and *note decimal.Decimal: 1fe. are
     properly cached.

   - bpo-46161(2): Fix the class building error when the arguments are
     constants and CALL_FUNCTION_EX is used.

   - bpo-46028(3): Fixes calculation of ‘sys._base_executable’ when
     inside a virtual environment that uses symlinks with different
     binary names than the base environment provides.

   - bpo-46091(4): Correctly calculate indentation levels for lines with
     whitespace character that are ended by line continuation
     characters.  Patch by Pablo Galindo

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46361

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46161

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46028

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46091


File: python.info,  Node: Library<97>,  Next: Build<37>,  Prev: Core and Builtins<94>,  Up: Python 3 11 0 alpha 5

1.24.37.4 Library
.................

   - bpo-30512(1): Add CAN Socket support for NetBSD.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30512


File: python.info,  Node: Build<37>,  Next: Core and Builtins<95>,  Prev: Library<97>,  Up: Python 3 11 0 alpha 5

1.24.37.5 Build
...............

   - bpo-46045(1): Do not use POSIX semaphores on NetBSD

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46045


File: python.info,  Node: Core and Builtins<95>,  Next: Library<98>,  Prev: Build<37>,  Up: Python 3 11 0 alpha 5

1.24.37.6 Core and Builtins
...........................

   - bpo-44024(1): Improve the *note TypeError: 198. message for
     non-string second arguments passed to the built-in functions *note
     getattr(): dcc. and *note hasattr(): 6fa.  Patch by Géry Ogam.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44024


File: python.info,  Node: Library<98>,  Next: Documentation<31>,  Prev: Core and Builtins<95>,  Up: Python 3 11 0 alpha 5

1.24.37.7 Library
.................

   - bpo-46624(1): Restore support for non-integer arguments of *note
     random.randrange(): a6d. and *note random.randint(): 1437.

   - bpo-46591(2): Make the IDLE doc URL on the About IDLE dialog
     clickable.

   - bpo-46565(3): Remove loop variables that are leaking into modules”
     namespaces.

   - bpo-46553(4): In *note typing.get_type_hints(): 8c1, support
     evaluating bare stringified ‘ClassVar’ annotations.  Patch by
     Gregory Beauregard.

   - bpo-46544(5): Don’t leak ‘x’ & ‘uspace’ intermediate vars in *note
     textwrap.TextWrapper: 11cf.

   - bpo-46487(6): Add the ‘get_write_buffer_limits’ method to
     ‘asyncio.transports.WriteTransport’ and to the SSL transport.

   - bpo-45173(7): Note the configparser deprecations will be removed in
     Python 3.12.

   - bpo-45162(8): The deprecated *note unittest: 10c. APIs removed in
     3.11a1 have been temporarily restored to be removed in 3.12 while
     cleanups in external projects go in.

   - bpo-46539(9): In *note typing.get_type_hints(): 8c1, support
     evaluating stringified ‘ClassVar’ and ‘Final’ annotations inside
     ‘Annotated’.  Patch by Gregory Beauregard.

   - bpo-46510(10): Add missing test for *note types.TracebackType: cec.
     and *note types.FrameType: 1bd6.  Calculate them directly from the
     caught exception without calling *note sys.exc_info(): 89b.

   - bpo-46491(11): Allow *note typing.Annotated: b39. to wrap *note
     typing.Final: 56e. and *note typing.ClassVar: 56d.  Patch by
     Gregory Beauregard.

   - bpo-46483(12): Remove *note __class_getitem__(): 944. from *note
     pathlib.PurePath: 6ce. as this class was not supposed to be
     generic.

   - bpo-46436(13): Fix command-line option ‘-d’/‘--directory’ in module
     *note http.server: 76. which is ignored when combined with
     command-line option ‘--cgi’.  Patch by Géry Ogam.

   - bpo-41403(14): Make ‘mock.patch()’ raise a *note TypeError: 198.
     with a relevant error message on invalid arg.  Previously it
     allowed a cryptic *note AttributeError: 5f0. to escape.

   - bpo-46474(15): In ‘importlib.metadata.EntryPoint.pattern’, avoid
     potential REDoS by limiting ambiguity in consecutive whitespace.

   - bpo-46474(16): Removed private method from
     ‘importlib.metadata.Path’.  Sync with importlib_metadata 4.10.0.

   - bpo-46470(17): Remove unused branch from
     ‘typing._remove_dups_flatten’

   - bpo-46469(18): *note asyncio: b. generic classes now return *note
     types.GenericAlias: 9ee. in ‘__class_getitem__’ instead of the same
     class.

   - bpo-41906(19): Support passing filter instances in the ‘filters’
     values of ‘handlers’ and ‘loggers’ in the dictionary passed to
     *note logging.config.dictConfig(): 13b8.

   - bpo-46422(20): Use ‘dis.Positions’ in ‘dis.Instruction’ instead of
     a regular ‘tuple’.

   - bpo-46434(21): *note pdb: aa. now gracefully handles ‘help’ when
     *note __doc__: 1bd7. is missing, for example when run with
     pregenerated optimized ‘.pyc’ files.

   - bpo-43869(22): Python uses the same time Epoch on all platforms.
     Add an explicit unit test to ensure that it’s the case.  Patch by
     Victor Stinner.

   - bpo-46414(23): Add *note typing.reveal_type(): 8ba.  Patch by Jelle
     Zijlstra.

   - bpo-40280(24): *note subprocess: dc. now imports Windows-specific
     imports when ‘msvcrt’ module is available, and POSIX-specific
     imports on all other platforms.  This gives a clean exception when
     ‘_posixsubprocess’ is not available (e.g.  Emscripten browser
     target).

   - bpo-40066(25): ‘IntEnum’, ‘IntFlag’, and ‘StrEnum’ use the mixed-in
     type for their ‘str()’ and ‘format()’ output.

   - bpo-46316(26): Optimize *note pathlib.Path.iterdir(): 26e. by
     removing an unnecessary check for special entries.

   - bpo-29688(27): Document *note pathlib.Path.absolute(): 1a0e. (which
     has always existed).

   - bpo-43012(28): The pathlib module’s obsolete and internal
     ‘_Accessor’ class has been removed to prepare the terrain for
     upcoming enhancements to the module.

   - bpo-46258(29): Speed up *note math.isqrt(): bfa. for small positive
     integers by replacing two division steps with a lookup table.

   - bpo-46242(30): Improve error message when creating a new *note
     enum.Enum: 843. type subclassing an existing ‘Enum’ with
     ‘_member_names_’ using ‘enum.Enum.__call__()’.

   - bpo-43118(31): Fix a bug in *note inspect.signature(): 22f. that
     was causing it to fail on some subclasses of classes with a
     ‘__text_signature__’ referencing module globals.  Patch by Weipeng
     Hong.

   - bpo-26552(32): Fixed case where failing *note
     asyncio.ensure_future(): e73. did not close the coroutine.  Patch
     by Kumar Aditya.

   - bpo-21987(33): Fix an issue with *note tarfile.TarFile.getmember():
     1bd8. getting a directory name with a trailing slash.

   - bpo-46124(34): Update *note zoneinfo: 13a. to rely on
     importlib.resources traversable API.

   - bpo-46103(35): Now *note inspect.getmembers(): 1bd9. only gets
     ‘__bases__’ attribute from class type.  Patch by Weipeng Hong.

   - bpo-46080(36): Fix exception in argparse help text generation if a
     *note argparse.BooleanOptionalAction: 1bda. argument’s default is
     ‘argparse.SUPPRESS’ and it has ‘help’ specified.  Patch by Felix
     Fontein.

   - bpo-44791(37): Fix substitution of *note ParamSpec: 488. in *note
     Concatenate: 9c9. with different parameter expressions.
     Substitution with a list of types returns now a tuple of types.
     Substitution with ‘Concatenate’ returns now a ‘Concatenate’ with
     concatenated lists of arguments.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46624

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46591

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46565

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46553

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46544

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46487

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45173

   (8) https://bugs.python.org/issue?@action=redirect&bpo=45162

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46539

   (10) https://bugs.python.org/issue?@action=redirect&bpo=46510

   (11) https://bugs.python.org/issue?@action=redirect&bpo=46491

   (12) https://bugs.python.org/issue?@action=redirect&bpo=46483

   (13) https://bugs.python.org/issue?@action=redirect&bpo=46436

   (14) https://bugs.python.org/issue?@action=redirect&bpo=41403

   (15) https://bugs.python.org/issue?@action=redirect&bpo=46474

   (16) https://bugs.python.org/issue?@action=redirect&bpo=46474

   (17) https://bugs.python.org/issue?@action=redirect&bpo=46470

   (18) https://bugs.python.org/issue?@action=redirect&bpo=46469

   (19) https://bugs.python.org/issue?@action=redirect&bpo=41906

   (20) https://bugs.python.org/issue?@action=redirect&bpo=46422

   (21) https://bugs.python.org/issue?@action=redirect&bpo=46434

   (22) https://bugs.python.org/issue?@action=redirect&bpo=43869

   (23) https://bugs.python.org/issue?@action=redirect&bpo=46414

   (24) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (25) https://bugs.python.org/issue?@action=redirect&bpo=40066

   (26) https://bugs.python.org/issue?@action=redirect&bpo=46316

   (27) https://bugs.python.org/issue?@action=redirect&bpo=29688

   (28) https://bugs.python.org/issue?@action=redirect&bpo=43012

   (29) https://bugs.python.org/issue?@action=redirect&bpo=46258

   (30) https://bugs.python.org/issue?@action=redirect&bpo=46242

   (31) https://bugs.python.org/issue?@action=redirect&bpo=43118

   (32) https://bugs.python.org/issue?@action=redirect&bpo=26552

   (33) https://bugs.python.org/issue?@action=redirect&bpo=21987

   (34) https://bugs.python.org/issue?@action=redirect&bpo=46124

   (35) https://bugs.python.org/issue?@action=redirect&bpo=46103

   (36) https://bugs.python.org/issue?@action=redirect&bpo=46080

   (37) https://bugs.python.org/issue?@action=redirect&bpo=44791


File: python.info,  Node: Documentation<31>,  Next: Tests<31>,  Prev: Library<98>,  Up: Python 3 11 0 alpha 5

1.24.37.8 Documentation
.......................

   - bpo-46463(1): Fixes ‘escape4chm.py’ script used when building the
     CHM documentation file

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46463


File: python.info,  Node: Tests<31>,  Next: Build<38>,  Prev: Documentation<31>,  Up: Python 3 11 0 alpha 5

1.24.37.9 Tests
...............

   - bpo-43478(1): Mocks can no longer be provided as the specs for
     other Mocks.  As a result, an already-mocked object cannot be
     passed to ‘mock.Mock()’.  This can uncover bugs in tests since
     these Mock-derived Mocks will always pass certain tests (e.g.
     isinstance) and builtin assert functions (e.g.
     assert_called_once_with) will unconditionally pass.

   - bpo-46616(2): Ensures ‘test_importlib.test_windows’ cleans up
     registry keys after completion.

   - bpo-44359(3): test_ftplib now silently ignores socket errors to
     prevent logging unhandled threading exceptions.  Patch by Victor
     Stinner.

   - bpo-46600(4): Fix test_gdb.test_pycfunction() for Python built with
     ‘clang -Og’.  Tolerate inlined functions in the gdb traceback.
     Patch by Victor Stinner.

   - bpo-46542(5): Fix a Python crash in test_lib2to3 when using Python
     built in debug mode: limit the recursion limit.  Patch by Victor
     Stinner.

   - bpo-46576(6): test_peg_generator now disables compiler optimization
     when testing compilation of its own C extensions to significantly
     speed up the testing on non-debug builds of CPython.

   - bpo-46542(7): Fix ‘test_json’ tests checking for *note
     RecursionError: f6a.: modify these tests to use
     ‘support.infinite_recursion()’.  Patch by Victor Stinner.

   - bpo-13886(8): Skip test_builtin PTY tests on non-ASCII characters
     if the readline module is loaded.  The readline module changes
     input() behavior, but test_builtin is not intended to test the
     readline module.  Patch by Victor Stinner.

   - bpo-40280(9): Add ‘test.support.requires_fork()’ decorators to mark
     tests that require a working *note os.fork(): 4b6.

   - bpo-40280(10): Add ‘test.support.requires_subprocess()’ decorator
     to mark tests which require working *note subprocess: dc. module or
     ‘os.spawn*’.  The wasm32-emscripten platform has no support for
     processes.

   - bpo-46126(11): Disable “descriptions” when running tests
     internally.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43478

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46616

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44359

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46600

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46542

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46576

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46542

   (8) https://bugs.python.org/issue?@action=redirect&bpo=13886

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (10) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (11) https://bugs.python.org/issue?@action=redirect&bpo=46126


File: python.info,  Node: Build<38>,  Next: Windows<32>,  Prev: Tests<31>,  Up: Python 3 11 0 alpha 5

1.24.37.10 Build
................

   - bpo-46602(1): Tidied up configure.ac so that conftest.c is
     truncated rather than appended.  This assists in the case where the
     “rm” of conftest.c fails to happen between tests.  Downstream
     issues such as a clobbered SOABI can result.

   - bpo-46600(2): Fix the test checking if the C compiler supports
     ‘-Og’ option in the ‘./configure’ script to also use ‘-Og’ on clang
     which supports it.  Patch by Victor Stinner.

   - bpo-38472(3): Fix GCC detection in setup.py when cross-compiling.
     The C compiler is now run with LC_ALL=C. Previously, the detection
     failed with a German locale.

   - bpo-46513(4): ‘configure’ no longer uses ‘AC_C_CHAR_UNSIGNED’ macro
     and ‘pyconfig.h’ no longer defines reserved symbol
     ‘__CHAR_UNSIGNED__’.

   - bpo-46471(5): Use global singletons for single byte bytes objects
     in deepfreeze.

   - bpo-46443(6): Deepfreeze now uses cached small integers as it saves
     some space for common small integers.

   - bpo-46429(7): Merge all deep-frozen files into one for space
     savings.  Patch by Kumar Aditya.

   - bpo-45569(8): The build now defaults to using 30-bit digits for
     Python integers.  Previously either 15-bit or 30-bit digits would
     be selected, depending on the platform.  15-bit digits may still be
     selected using the ‘--enable-big-digits=15’ option to the
     ‘configure’ script, or by defining ‘PYLONG_BITS_IN_DIGIT’ in
     ‘pyconfig.h’.

   - bpo-45925(9): Update Windows installer to use SQLite 3.37.2.

   - bpo-43112(10): Detect musl libc as a separate SOABI (tagged as
     ‘linux-musl’).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46602

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46600

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38472

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46513

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46471

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46443

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46429

   (8) https://bugs.python.org/issue?@action=redirect&bpo=45569

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45925

   (10) https://bugs.python.org/issue?@action=redirect&bpo=43112


File: python.info,  Node: Windows<32>,  Next: macOS<22>,  Prev: Build<38>,  Up: Python 3 11 0 alpha 5

1.24.37.11 Windows
..................

   - bpo-33125(1): The traditional EXE/MSI based installer for Windows
     is now available for ARM64

   - bpo-46362(2): os.path.abspath(«C:CON») is now fixed to return
     «\.CON», not the same path.  The regression was true of all legacy
     DOS devices such as COM1, LPT1, or NUL.

   - bpo-44934(3): The installer now offers a command-line only option
     to add the installation directory to the end of ‘PATH’ instead of
     at the start.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33125

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46362

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44934


File: python.info,  Node: macOS<22>,  Next: IDLE<17>,  Prev: Windows<32>,  Up: Python 3 11 0 alpha 5

1.24.37.12 macOS
................

   - bpo-45925(1): Update macOS installer to SQLite 3.37.2.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45925


File: python.info,  Node: IDLE<17>,  Next: C API<33>,  Prev: macOS<22>,  Up: Python 3 11 0 alpha 5

1.24.37.13 IDLE
...............

   - bpo-45296(1): Clarify close, quit, and exit in IDLE. In the File
     menu, “Close” and “Exit” are now “Close Window” (the current one)
     and “Exit” is now “Exit IDLE” (by closing all windows).  In Shell,
     “quit()” and “exit()” mean “close Shell”.  If there are no other
     windows, this also exits IDLE.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45296


File: python.info,  Node: C API<33>,  Prev: IDLE<17>,  Up: Python 3 11 0 alpha 5

1.24.37.14 C API
................

   - bpo-40170(1): Remove the ‘PyHeapType_GET_MEMBERS()’ macro.  It was
     exposed in the public C API by mistake, it must only be used by
     Python internally.  Use the ‘PyTypeObject.tp_members’ member
     instead.  Patch by Victor Stinner.

   - bpo-40170(2): Move _Py_GetAllocatedBlocks() and
     _PyObject_DebugMallocStats() private functions to the internal C
     API. Patch by Victor Stinner.

   - bpo-46433(3): The internal function _PyType_GetModuleByDef now
     correctly handles inheritance patterns involving static types.

   - bpo-45459(4): *note Py_buffer: 95d. and various ‘Py_buffer’ related
     functions are now part of the limited API and stable ABI.

   - bpo-14916(5): Fixed bug in the tokenizer that prevented
     ‘PyRun_InteractiveOne’ from parsing from the provided FD.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46433

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45459

   (5) https://bugs.python.org/issue?@action=redirect&bpo=14916


File: python.info,  Node: Python 3 11 0 alpha 4,  Next: Python 3 11 0 alpha 3,  Prev: Python 3 11 0 alpha 5,  Up: Changelog

1.24.38 Python 3.11.0 alpha 4
-----------------------------

'Release date: 2022-01-13'

* Menu:

* Core and Builtins: Core and Builtins<96>.
* Library: Library<99>.
* Core and Builtins: Core and Builtins<97>.
* Library: Library<100>.
* Core and Builtins: Core and Builtins<98>.
* Library: Library<101>.
* Core and Builtins: Core and Builtins<99>.
* Library: Library<102>.
* Documentation: Documentation<32>.
* Tests: Tests<32>.
* Build: Build<39>.
* Windows: Windows<33>.
* macOS: macOS<23>.
* C API: C API<34>.


File: python.info,  Node: Core and Builtins<96>,  Next: Library<99>,  Up: Python 3 11 0 alpha 4

1.24.38.1 Core and Builtins
...........................

   - bpo-46070(1): *note Py_EndInterpreter(): 182d. now explicitly
     untracks all objects currently tracked by the GC. Previously, if an
     object was used later by another interpreter, calling *note
     PyObject_GC_UnTrack(): 170c. on the object crashed if the previous
     or the next object of the ‘PyGC_Head’ structure became a dangling
     pointer.  Patch by Victor Stinner.

   - bpo-46347(2): Fix memory leak in PyEval_EvalCodeEx.

   - bpo-46339(3): Fix a crash in the parser when retrieving the error
     text for multi-line f-strings expressions that do not start in the
     first line of the string.  Patch by Pablo Galindo

   - bpo-46331(4): Do not set line number of instruction storing
     doc-string.  Fixes regression introduced in 3.11 alpha.

   - bpo-46314(5): Remove spurious «call» event when creating a lambda
     function that was accidentally introduced in 3.11a4.

   - bpo-46289(6): ASDL declaration of ‘FormattedValue’ has changed to
     reflect ‘conversion’ field is not optional.

   - bpo-46297(7): Fixed an interpreter crash on bootup with multiple
     PythonPaths set in the Windows registry.  Patch by Derzsi Dániel.

   - bpo-46237(8): Fix the line number of tokenizer errors inside
     f-strings.  Patch by Pablo Galindo.

   - bpo-46263(9): We always expect the «use_frozen_modules» config to
     be set, now that getpath.c was rewritten in pure Python and the
     logic improved.

   - bpo-46006(10): Fix a regression when a type method like
     ‘__init__()’ is modified in a subinterpreter.  Fix a regression in
     ‘_PyUnicode_EqualToASCIIId()’ and type ‘update_slot()’.  Revert the
     change which made the Unicode dictionary of interned strings
     compatible with subinterpreters: the internal interned dictionary
     is shared again by all interpreters.  Patch by Victor Stinner.

   - bpo-45923(11): Add RESUME opcode.  This is a logical no-op.  It is
     emitted by the compiler anywhere a Python function can be entered.
     It is used by the interpreter to perform tracing and optimizer
     checks.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46070

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46347

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46339

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46331

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46314

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46289

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46297

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46237

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46263

   (10) https://bugs.python.org/issue?@action=redirect&bpo=46006

   (11) https://bugs.python.org/issue?@action=redirect&bpo=45923


File: python.info,  Node: Library<99>,  Next: Core and Builtins<97>,  Prev: Core and Builtins<96>,  Up: Python 3 11 0 alpha 4

1.24.38.2 Library
.................

   - bpo-46208(1): Fix the regression of os.path.normpath(«A/../../B»)
     not returning expected «../B» but «B».

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46208


File: python.info,  Node: Core and Builtins<97>,  Next: Library<100>,  Prev: Library<99>,  Up: Python 3 11 0 alpha 4

1.24.38.3 Core and Builtins
...........................

   - bpo-46240(1): Correct the error message for unclosed parentheses
     when the tokenizer doesn’t reach the end of the source when the
     error is reported.  Patch by Pablo Galindo

   - bpo-46009(2): Remove the ‘GEN_START’ opcode.

   - bpo-46235(3): Certain sequence multiplication operations like ‘[0]
     * 1_000’ are now faster due to reference-counting optimizations.
     Patch by Dennis Sweeney.

   - bpo-46221(4): ‘PREP_RERAISE_STAR’ no longer pushes ‘lasti’ to the
     stack.

   - bpo-46202(5): Remove ‘POP_EXCEPT_AND_RERAISE’ and replace it by an
     equivalent sequence of other opcodes.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46240

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46009

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46235

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46221

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46202


File: python.info,  Node: Library<100>,  Next: Core and Builtins<98>,  Prev: Core and Builtins<97>,  Up: Python 3 11 0 alpha 4

1.24.38.4 Library
.................

   - bpo-46085(1): Fix iterator cache mechanism of ‘OrderedDict’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46085


File: python.info,  Node: Core and Builtins<98>,  Next: Library<101>,  Prev: Library<100>,  Up: Python 3 11 0 alpha 4

1.24.38.5 Core and Builtins
...........................

   - bpo-46055(1): Speed up shifting operation involving integers less
     than *note PyLong_BASE: 1be8.  Patch by Xinhang Xu.

   - bpo-46110(2): Add a maximum recursion check to the PEG parser to
     avoid stack overflow.  Patch by Pablo Galindo

   - bpo-46107(3): Fix bug where ‘ExceptionGroup.split()’ and
     ‘ExceptionGroup.subgroup()’ did not copy the exception group’s
     ‘__note__’ field to the parts.

   - bpo-45711(4): The interpreter state’s representation of handled
     exceptions (a.k.a exc_info, or _PyErr_StackItem) now has only the
     ‘exc_value’ field, ‘exc_type’ and ‘exc_traceback’ have been removed
     as their values can be derived from ‘exc_value’.

   - bpo-44525(5): Replace the four call bytecode instructions which one
     pre-call instruction and two call instructions.

     Removes ‘CALL_FUNCTION’, ‘CALL_FUNCTION_KW’, ‘CALL_METHOD’ and
     ‘CALL_METHOD_KW’.

     Adds ‘CALL_NO_KW’ and ‘CALL_KW’ call instructions, and
     ‘PRECALL_METHOD’ prefix for pairing with ‘LOAD_METHOD’.

   - bpo-46039(6): Remove the ‘YIELD_FROM’ instruction and replace it
     with the ‘SEND’ instruction which performs the same operation, but
     without the loop.

   - bpo-45635(7): The code called from ‘_PyErr_Display()’ was
     refactored to improve error handling.  It now exits immediately
     upon an unrecoverable error.

   - bpo-46054(8): Fix parser error when parsing non-utf8 characters in
     source files.  Patch by Pablo Galindo.

   - bpo-46042(9): Improve the location of the caret in *note
     SyntaxError: 18e. exceptions emitted by the symbol table.  Patch by
     Pablo Galindo.

   - bpo-46049(10): Ensure ‘._pth’ files work as intended on platforms
     other than Windows.

   - bpo-46048(11): Fixes parsing of ‘._pth’ files on startup so that
     single-character paths are correctly read.

   - bpo-37971(12): Fix a bug where the line numbers given in a
     traceback when a decorator application raised an exception were
     wrong.

   - bpo-46031(13): Add *note POP_JUMP_IF_NOT_NONE: 1b68. and *note
     POP_JUMP_IF_NONE: 1b67. opcodes to speed up conditional jumps.

   - bpo-45654(14): Deepfreeze *note runpy: c3, patch by Kumar Aditya.

   - bpo-46025(15): Fix a crash in the *note atexit: d. module involving
     functions that unregister themselves before raising exceptions.
     Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46055

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46110

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46107

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45711

   (5) https://bugs.python.org/issue?@action=redirect&bpo=44525

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46039

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45635

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46054

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46042

   (10) https://bugs.python.org/issue?@action=redirect&bpo=46049

   (11) https://bugs.python.org/issue?@action=redirect&bpo=46048

   (12) https://bugs.python.org/issue?@action=redirect&bpo=37971

   (13) https://bugs.python.org/issue?@action=redirect&bpo=46031

   (14) https://bugs.python.org/issue?@action=redirect&bpo=45654

   (15) https://bugs.python.org/issue?@action=redirect&bpo=46025


File: python.info,  Node: Library<101>,  Next: Core and Builtins<99>,  Prev: Core and Builtins<98>,  Up: Python 3 11 0 alpha 4

1.24.38.6 Library
.................

   - bpo-46000(1): Improve compatibility of the *note curses: 2f. module
     with NetBSD curses.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46000


File: python.info,  Node: Core and Builtins<99>,  Next: Library<102>,  Prev: Library<101>,  Up: Python 3 11 0 alpha 4

1.24.38.7 Core and Builtins
...........................

   - bpo-44525(1): Specialize the CALL_FUNCTION instruction for calls to
     builtin types with a single argument.  Speeds up ‘range(x)’,
     ‘list(x)’, and specifically ‘type(obj)’.

   - bpo-42918(2): Fix bug where the built-in *note compile(): 4b2.
     function did not always raise a *note SyntaxError: 18e. when passed
     multiple statements in “single” mode.  Patch by Weipeng Hong.

   - bpo-45953(3): The main interpreter in _PyRuntimeState.interpreters
     is now statically allocated (as part of _PyRuntime).  Likewise for
     the initial thread state of each interpreter.  This means less
     allocation during runtime init, as well as better memory locality
     for these key state objects.

   - bpo-45292(4): Complete the PEP 654(5) implementation: add
     ‘except*’.

   - bpo-43413(6): Revert changes in ‘set.__init__’.  Subclass of *note
     set: 184. needs to define a ‘__init__()’ method if it defines a
     ‘__new__()’ method with additional keyword parameters.

   - bpo-43931(7): Added the *note Py_Version: 381. constant which bears
     the same value as *note PY_VERSION_HEX: 382.  Patch by Gabriele N.
     Tornetta.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44525

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42918

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45953

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45292

   (5) https://peps.python.org/pep-0654/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43413

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43931


File: python.info,  Node: Library<102>,  Next: Documentation<32>,  Prev: Core and Builtins<99>,  Up: Python 3 11 0 alpha 4

1.24.38.8 Library
.................

   - bpo-46342(1): The ‘@typing.final’ decorator now sets the
     ‘__final__’ attribute on the decorated object to allow runtime
     introspection.  Patch by Jelle Zijlstra.

   - bpo-46328(2): Added the *note sys.exception(): 89c. method which
     returns the active exception instance.

   - bpo-46307(3): Add *note string.Template.is_valid(): 897. and *note
     string.Template.get_identifiers(): 896. methods.

   - bpo-46306(4): Assume that *note types.CodeType: 32f. always has
     ‘types.CodeType.co_firstlineno’ in *note doctest: 3e.

   - bpo-40479(5): Fix *note hashlib: 6c. 'usedforsecurity' option to
     work correctly with OpenSSL 3.0.0 in FIPS mode.

   - bpo-46070(6): Fix possible segfault when importing the *note
     asyncio: b. module from different sub-interpreters in parallel.
     Patch by Erlend E. Aasland.

   - bpo-46244(7): Removed ‘__slots__’ from *note typing.ParamSpec: 488.
     and *note typing.TypeVar: 487.  They served no purpose.  Patch by
     Arie Bovenberg.

   - bpo-46278(8): Reflect ‘context’ argument in
     ‘AbstractEventLoop.call_*()’ methods.  Loop implementations already
     support it.

   - bpo-46269(9): Remove special-casing of ‘__new__’ in *note
     enum.Enum.__dir__(): 1bec.

   - bpo-46266(10): Improve day constants in *note calendar: 15.

     Now all constants (‘MONDAY’ … ‘SUNDAY’) are documented, tested, and
     added to ‘__all__’.

   - bpo-46257(11): Optimized the mean, variance, and stdev functions in
     the statistics module.  If the input is an iterator, it is consumed
     in a single pass rather than eating memory by conversion to a list.
     The single pass algorithm is about twice as fast as the previous
     two pass code.

   - bpo-41011(12): Added two new variables to 'pyvenv.cfg' which is
     generated by *note venv: 117. module: 'executable' for the
     executable and 'command' for the command line used to create the
     environment.

   - bpo-46239(13): Improve error message when importing
     ‘asyncio.windows_events’ on non-Windows.

   - bpo-46238(14): Reuse ‘_winapi’ constants in
     ‘asyncio.windows_events’.

   - bpo-46222(15): Adding ‘SF_NOCACHE’ sendfile constant for FreeBSD
     for the posixmodule.

   - bpo-37295(16): Add fast path for ‘0 <= k <= n <= 67’ for *note
     math.comb(): 8e0.

   - bpo-46176(17): Adding the ‘MAP_STACK’ constant for the mmap module.

   - bpo-43424(18): Deprecate ‘webbrowser.MacOSXOSAScript._name’ and use
     ‘name’ instead.

   - bpo-45321(19): Added missing error codes to module
     ‘xml.parsers.expat.errors’.

   - bpo-46125(20): Refactor tests to test traversable API directly.
     Includes changes from importlib 5.4.0.

   - bpo-46118(21): Moved importlib.resources and its related
     functionality to a package.

   - bpo-37578(22): Add 'include_hidden' parameter to *note glob(): 5a0.
     and *note iglob(): a0a. to match hidden files and directories when
     using special characters like ‘*’, ‘**’, ‘?’ and ‘[]’.

   - bpo-20369(23): *note concurrent.futures.wait(): 1bed. no longer
     blocks forever when given duplicate Futures.  Patch by Kumar
     Aditya.

   - bpo-46105(24): Honor spec when generating requirement specs with
     urls and extras (importlib_metadata 4.8.3).

   - bpo-44893(25): EntryPoint objects are no longer tuples.
     Recommended means to access is by attribute (“.name”, “.group”) or
     accessor (“.load()”).  Access by index is deprecated and will raise
     deprecation warning.

   - bpo-22815(26): Print unexpected successes together with failures
     and errors in summary in *note unittest.TextTestResult: 755.

   - bpo-22047(27): Calling ‘add_argument_group()’ on an argument group
     is deprecated.  Calling ‘add_argument_group()’ or
     ‘add_mutually_exclusive_group()’ on a mutually exclusive group is
     deprecated.

     These features were never supported and do not always work
     correctly.  The functions exist on the API by accident through
     inheritance and will be removed in the future.

   - bpo-26952(28): *note argparse: 7. raises *note ValueError: 2ec.
     with clear message when trying to render usage for an empty
     mutually exclusive group.  Previously it raised a cryptic *note
     IndexError: 173c.

   - bpo-45615(29): Functions in the *note traceback: 104. module raise
     *note TypeError: 198. rather than *note AttributeError: 5f0. when
     an exception argument is not of type *note BaseException: 7d8.

   - bpo-16594(30): Add allow allow_reuse_port flag in socketserver.

   - bpo-27718(31): Fix help for the *note signal: cb. module.  Some
     functions (e.g.  ‘signal()’ and ‘getsignal()’) were omitted.

   - bpo-46032(32): The ‘registry()’ method of *note
     functools.singledispatch(): 84c. functions checks now the first
     argument or the first parameter annotation and raises a TypeError
     if it is not supported.  Previously unsupported «types» were
     ignored (e.g.  ‘typing.List[int]’) or caused an error at calling
     time (e.g.  ‘list[int]’).

   - bpo-46014(33): Add ability to use ‘typing.Union’ and
     ‘types.UnionType’ as dispatch argument to
     ‘functools.singledispatch’.  Patch provided by Yurii Karabas.

   - bpo-27062(34): Add ‘__all__’ to *note inspect: 82, patch by Kumar
     Aditya.

   - bpo-46018(35): Ensure that *note math.expm1(): 13f4. does not raise
     on underflow.

   - bpo-46016(36): Adding ‘F_DUP2FD’ and ‘F_DUP2FD_CLOEXEC’ constants
     from FreeBSD into the *note fcntl: 5d. module.

   - bpo-45755(37): *note typing: 10a. generic aliases now reveal the
     class attributes of the original generic class when passed to
     ‘dir()’.  This was the behavior up to Python 3.6, but was changed
     in 3.7-3.9.

   - bpo-45874(38): The empty query string, consisting of no query
     arguments, is now handled correctly in ‘urllib.parse.parse_qsl’.
     This caused problems before when strict parsing was enabled.

   - bpo-44674(39): Change how dataclasses disallows mutable default
     values.  It used to use a list of known types (list, dict, set).
     Now it disallows unhashable objects to be defaults.  It’s using
     unhashability as a proxy for mutability.  Patch by Eric V. Smith,
     idea by Raymond Hettinger.

   - bpo-23882(40): Remove namespace package (PEP 420) support from
     unittest discovery.  It was introduced in Python 3.4 but has been
     broken since Python 3.7.

   - bpo-25066(41): Added a ‘__repr__()’ method to *note
     multiprocessing.Event: 1bee. objects, patch by Kumar Aditya.

   - bpo-45643(42): Added *note signal.SIGSTKFLT: 1bef. on platforms
     where this signal is defined.

   - bpo-44092(43): Fetch across rollback no longer raises *note
     InterfaceError: 88e.  Instead we leave it to the SQLite library to
     handle these cases.  Patch by Erlend E. Aasland.

   - bpo-42413(44): Replace ‘concurrent.futures.TimeoutError’ and
     ‘asyncio.TimeoutError’ with builtin *note TimeoutError: a38, keep
     these names as deprecated aliases.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46342

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46328

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46307

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46306

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40479

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46070

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46244

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46278

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46269

   (10) https://bugs.python.org/issue?@action=redirect&bpo=46266

   (11) https://bugs.python.org/issue?@action=redirect&bpo=46257

   (12) https://bugs.python.org/issue?@action=redirect&bpo=41011

   (13) https://bugs.python.org/issue?@action=redirect&bpo=46239

   (14) https://bugs.python.org/issue?@action=redirect&bpo=46238

   (15) https://bugs.python.org/issue?@action=redirect&bpo=46222

   (16) https://bugs.python.org/issue?@action=redirect&bpo=37295

   (17) https://bugs.python.org/issue?@action=redirect&bpo=46176

   (18) https://bugs.python.org/issue?@action=redirect&bpo=43424

   (19) https://bugs.python.org/issue?@action=redirect&bpo=45321

   (20) https://bugs.python.org/issue?@action=redirect&bpo=46125

   (21) https://bugs.python.org/issue?@action=redirect&bpo=46118

   (22) https://bugs.python.org/issue?@action=redirect&bpo=37578

   (23) https://bugs.python.org/issue?@action=redirect&bpo=20369

   (24) https://bugs.python.org/issue?@action=redirect&bpo=46105

   (25) https://bugs.python.org/issue?@action=redirect&bpo=44893

   (26) https://bugs.python.org/issue?@action=redirect&bpo=22815

   (27) https://bugs.python.org/issue?@action=redirect&bpo=22047

   (28) https://bugs.python.org/issue?@action=redirect&bpo=26952

   (29) https://bugs.python.org/issue?@action=redirect&bpo=45615

   (30) https://bugs.python.org/issue?@action=redirect&bpo=16594

   (31) https://bugs.python.org/issue?@action=redirect&bpo=27718

   (32) https://bugs.python.org/issue?@action=redirect&bpo=46032

   (33) https://bugs.python.org/issue?@action=redirect&bpo=46014

   (34) https://bugs.python.org/issue?@action=redirect&bpo=27062

   (35) https://bugs.python.org/issue?@action=redirect&bpo=46018

   (36) https://bugs.python.org/issue?@action=redirect&bpo=46016

   (37) https://bugs.python.org/issue?@action=redirect&bpo=45755

   (38) https://bugs.python.org/issue?@action=redirect&bpo=45874

   (39) https://bugs.python.org/issue?@action=redirect&bpo=44674

   (40) https://bugs.python.org/issue?@action=redirect&bpo=23882

   (41) https://bugs.python.org/issue?@action=redirect&bpo=25066

   (42) https://bugs.python.org/issue?@action=redirect&bpo=45643

   (43) https://bugs.python.org/issue?@action=redirect&bpo=44092

   (44) https://bugs.python.org/issue?@action=redirect&bpo=42413


File: python.info,  Node: Documentation<32>,  Next: Tests<32>,  Prev: Library<102>,  Up: Python 3 11 0 alpha 4

1.24.38.9 Documentation
.......................

   - bpo-46196(1): Document method *note cmd.Cmd.columnize(): 1bf1.

   - bpo-46120(2): State that ‘|’ is preferred for readability over
     ‘Union’ in the *note typing: 10a. docs.

   - bpo-46109(3): Extracted ‘importlib.resources’ and
     ‘importlib.resources.abc’ documentation into separate files.

   - bpo-19737(4): Update the documentation for the *note globals():
     1bf2. function.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46196

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46120

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46109

   (4) https://bugs.python.org/issue?@action=redirect&bpo=19737


File: python.info,  Node: Tests<32>,  Next: Build<39>,  Prev: Documentation<32>,  Up: Python 3 11 0 alpha 4

1.24.38.10 Tests
................

   - bpo-46296(1): Add a test case for *note enum: 5a. with ‘_use_args_
     == True’ and ‘_member_type_ == object’.

   - bpo-46205(2): Fix hang in runtest_mp due to race condition

   - bpo-46263(3): Fix test_capi on FreeBSD 14-dev: instruct jemalloc to
     not fill freed memory with junk byte.

   - bpo-46262(4): Cover ‘ValueError’ path in tests for
     ‘enum.Flag._missing_()’.

   - bpo-46150(5): Now ‘fakename’ in
     ‘test_pathlib.PosixPathTest.test_expanduser’ is checked to be
     non-existent.

   - bpo-46129(6): Rewrite ‘asyncio.locks’ tests with *note
     unittest.IsolatedAsyncioTestCase: 361. usage.

   - bpo-23819(7): Fixed *note asyncio: b. tests in python optimized
     mode.  Patch by Kumar Aditya.

   - bpo-46114(8): Fix test case for OpenSSL 3.0.1 version.  OpenSSL 3.0
     uses ‘0xMNN00PP0L’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46296

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46205

   (3) https://bugs.python.org/issue?@action=redirect&bpo=46263

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46262

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46150

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46129

   (7) https://bugs.python.org/issue?@action=redirect&bpo=23819

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46114


File: python.info,  Node: Build<39>,  Next: Windows<33>,  Prev: Tests<32>,  Up: Python 3 11 0 alpha 4

1.24.38.11 Build
................

   - bpo-44133(1): When Python is configured with *note
     -without-static-libpython: a90, the Python static library
     (libpython.a) is no longer built.  Patch by Victor Stinner.

   - bpo-44133(2): When Python is built without *note -enable-shared:
     a65, the ‘python’ program is now linked to object files, rather
     than being linked to the Python static library (libpython.a), to
     make sure that all symbols are exported.  Previously, the linker
     omitted some symbols like the ‘Py_FrozenMain()’ function.  Patch by
     Victor Stinner.

   - bpo-40280(3): The ‘configure’ script has a new option
     ‘--with-emscripten-target’ to select browser or node as Emscripten
     build target.

   - bpo-46315(4): Added and fixed ‘#ifdef HAVE_FEATURE’ checks for
     functionality that is not available on WASI platform.

   - bpo-45723(5): Fixed a regression in ‘configure’ check for *note
     select.epoll(): 1196.

   - bpo-46263(6): ‘configure’ no longer sets ‘MULTIARCH’ on FreeBSD
     platforms.

   - bpo-46106(7): Updated OpenSSL to 1.1.1m in Windows builds, macOS
     installer builds, and CI. Patch by Kumar Aditya.

   - bpo-46088(8): Automatically detect or install bootstrap Python
     runtime when building from Visual Studio.

   - bpo-46072(9): Add a –with-pystats configure option to turn on
     internal statistics gathering.

   - bpo-40280(10): A new directory ‘Tools/wasm’ contains
     WebAssembly-related helpers like ‘config.site’ override for
     wasm32-emscripten, wasm assets generator to bundle the stdlib, and
     a README.

   - bpo-46023(11): ‘makesetup’ no longer builds extensions that have
     been marked as 'disabled'.  This allows users to disable modules in
     ‘Modules/Setup.local’.

   - bpo-45949(12): Use pure Python ‘freeze_module’ for all but
     importlib bootstrap files.  ‘--with-freeze-module’ ‘configure’
     option is no longer needed for cross builds.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44133

   (2) https://bugs.python.org/issue?@action=redirect&bpo=44133

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (4) https://bugs.python.org/issue?@action=redirect&bpo=46315

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45723

   (6) https://bugs.python.org/issue?@action=redirect&bpo=46263

   (7) https://bugs.python.org/issue?@action=redirect&bpo=46106

   (8) https://bugs.python.org/issue?@action=redirect&bpo=46088

   (9) https://bugs.python.org/issue?@action=redirect&bpo=46072

   (10) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (11) https://bugs.python.org/issue?@action=redirect&bpo=46023

   (12) https://bugs.python.org/issue?@action=redirect&bpo=45949


File: python.info,  Node: Windows<33>,  Next: macOS<23>,  Prev: Build<39>,  Up: Python 3 11 0 alpha 4

1.24.38.12 Windows
..................

   - bpo-46217(1): Removed parameter that is unsupported on Windows 8.1
     and early Windows 10 and may have caused build or runtime failures.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46217


File: python.info,  Node: macOS<23>,  Next: C API<34>,  Prev: Windows<33>,  Up: Python 3 11 0 alpha 4

1.24.38.13 macOS
................

   - bpo-40477(1): The Python Launcher app for macOS now properly
     launches scripts and, if necessary, the Terminal app when running
     on recent macOS releases.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40477


File: python.info,  Node: C API<34>,  Prev: macOS<23>,  Up: Python 3 11 0 alpha 4

1.24.38.14 C API
................

   - bpo-46236(1): Fix a bug in *note PyFunction_GetAnnotations(): 1b1f.
     that caused it to return a ‘tuple’ instead of a ‘dict’.

   - bpo-46140(2): *note PyBuffer_GetPointer(): 95e, *note
     PyBuffer_FromContiguous(): 961, *note PyBuffer_ToContiguous(): 960.
     and *note PyMemoryView_FromBuffer(): 966. now take buffer info by
     ‘const Py_buffer *’ instead of ‘Py_buffer *’, as they do not need
     mutability.  *note PyBuffer_FromContiguous(): 961. also now takes
     the source buffer as ‘const void *’, and similarly *note
     PyBuffer_GetPointer(): 95e. takes the strides as ‘const Py_ssize_t
     *’.

   - bpo-45855(3): Document that the 'no_block' argument to *note
     PyCapsule_Import(): 1bf8. is a no-op now.

   - bpo-45855(4): Replaced deprecated usage of *note
     PyImport_ImportModuleNoBlock(): 3db. with *note
     PyImport_ImportModule(): 3dc. in stdlib modules.  Patch by Kumar
     Aditya.

   - bpo-46007(5): The ‘PyUnicode_CHECK_INTERNED()’ macro has been
     excluded from the limited C API. It was never usable there, because
     it used internal structures which are not available in the limited
     C API. Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46236

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46140

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45855

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45855

   (5) https://bugs.python.org/issue?@action=redirect&bpo=46007


File: python.info,  Node: Python 3 11 0 alpha 3,  Next: Python 3 11 0 alpha 2,  Prev: Python 3 11 0 alpha 4,  Up: Changelog

1.24.39 Python 3.11.0 alpha 3
-----------------------------

'Release date: 2021-12-08'

* Menu:

* Core and Builtins: Core and Builtins<100>.
* Library: Library<103>.
* Core and Builtins: Core and Builtins<101>.
* Library: Library<104>.
* Documentation: Documentation<33>.
* Tests: Tests<33>.
* Build: Build<40>.
* Windows: Windows<34>.
* macOS: macOS<24>.
* C API: C API<35>.


File: python.info,  Node: Core and Builtins<100>,  Next: Library<103>,  Up: Python 3 11 0 alpha 3

1.24.39.1 Core and Builtins
...........................

   - bpo-46009(1): Restore behavior from 3.9 and earlier when sending
     non-None to newly started generator.  In 3.9 this did not affect
     the state of the generator.  In 3.10.0 and 3.10.1
     ‘gen_func().send(0)’ is equivalent to
     ‘gen_func().throw(TypeError(...)’ which exhausts the generator.  In
     3.10.2 onward, the behavior has been reverted to that of 3.9.

   - bpo-46004(2): Fix the *note SyntaxError: 18e. location for errors
     involving for loops with invalid targets.  Patch by Pablo Galindo

   - bpo-45711(3): ‘_PyErr_ChainStackItem()’ no longer normalizes
     ‘exc_info’ (including setting the traceback on the exception
     instance) because ‘exc_info’ is always normalized.

   - bpo-45607(4): The ‘__note__’ field was added to *note
     BaseException: 7d8.  It is ‘None’ by default but can be set to a
     string which is added to the exception’s traceback.

   - bpo-45947(5): Place pointers to dict and values immediately before
     GC header.  This reduces number of dependent memory loads to access
     either dict or values from 3 to 1.

   - bpo-45915(6): ‘is_valid_fd’ now uses faster ‘fcntl(fd, F_GETFD)’ on
     Linux, macOS, and Windows.

   - bpo-44530(7): Reverts a change to the ‘code.__new__’ *note audit
     event: 1bfb. from an earlier prerelease.

   - bpo-42268(8): Fail the configure step if the selected compiler
     doesn’t support memory sanitizer.  Patch by Pablo Galindo

   - bpo-45711(9): The three values of ‘exc_info’ are now always
     consistent with each other.  In particular, the ‘type’ and
     ‘traceback’ fields are now derived from the exception instance.
     This impacts the return values of *note sys.exc_info(): 89b. and
     *note PyErr_GetExcInfo(): 977. if the exception instance is
     modified while the exception is handled, as well as *note
     PyErr_SetExcInfo(): 976, which now ignores the ‘type’ and
     ‘traceback’ arguments provided to it.

   - bpo-45727(10): Refine the custom syntax error that suggests that a
     comma may be missing to trigger only when the expressions are
     detected between parentheses or brackets.  Patch by Pablo Galindo

   - bpo-45885(11): Specialized the ‘COMPARE_OP’ opcode using the PEP
     659 machinery.

   - bpo-45786(12): Allocate space for the interpreter frame in the
     frame object, to avoid an additional allocation when the frame
     object outlives the frame activation.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46009

   (2) https://bugs.python.org/issue?@action=redirect&bpo=46004

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45711

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45607

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45947

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45915

   (7) https://bugs.python.org/issue?@action=redirect&bpo=44530

   (8) https://bugs.python.org/issue?@action=redirect&bpo=42268

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45711

   (10) https://bugs.python.org/issue?@action=redirect&bpo=45727

   (11) https://bugs.python.org/issue?@action=redirect&bpo=45885

   (12) https://bugs.python.org/issue?@action=redirect&bpo=45786


File: python.info,  Node: Library<103>,  Next: Core and Builtins<101>,  Prev: Core and Builtins<100>,  Up: Python 3 11 0 alpha 3

1.24.39.2 Library
.................

   - bpo-45614(1): Fix *note traceback: 104. display for exceptions with
     invalid module name.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45614


File: python.info,  Node: Core and Builtins<101>,  Next: Library<104>,  Prev: Library<103>,  Up: Python 3 11 0 alpha 3

1.24.39.3 Core and Builtins
...........................

   - bpo-45813(1): Fix crash when calling coro.cr_frame.clear() after
     coroutine has been freed.

   - bpo-45811(2): Improve the tokenizer errors when encountering
     invisible control characters in the parser.  Patch by Pablo Galindo

   - bpo-45848(3): Allow the parser to obtain error lines directly from
     encoded files.  Patch by Pablo Galindo

   - bpo-45709(4): Restore behavior from 3.10 when tracing an exception
     raised within a with statement.

   - bpo-44525(5): Adds new *note COPY_FREE_VARS: 90e. opcode, to make
     copying of free variables from function to frame explicit.  Helps
     optimization of calls to Python function.

   - bpo-45829(6): Specialize ‘BINARY_SUBSCR’ for classes with a
     ‘__getitem__’ method implemented in Python

   - bpo-45826(7): Fixed a crash when calling ‘.with_traceback(None)’ on
     ‘NameError’.  This occurs internally in
     ‘unittest.TestCase.assertRaises()’.

   - bpo-45822(8): Fixed a bug in the parser that was causing it to not
     respect PEP 263(9) coding cookies when no flags are provided.
     Patch by Pablo Galindo

   - bpo-45820(10): Fix a segfault when the parser fails without reading
     any input.  Patch by Pablo Galindo

   - bpo-45636(11): Simplify the implementation of *note BINARY_OP: 366.
     by indexing into an array of function pointers (rather than
     switching on the oparg).

   - bpo-42540(12): Fix crash when *note os.fork(): 4b6. is called with
     an active non-default memory allocator.

   - bpo-45738(13): Fix computation of error location for invalid
     continuation characters in the parser.  Patch by Pablo Galindo.

   - bpo-45636(14): Remove an existing «fast path» for old-style string
     formatting, since it no longer appears to have any measurable
     impact.

   - bpo-45753(15): Make recursion checks a bit more efficient by
     tracking amount of calls left before overflow.

   - bpo-45773(16): Fix a compiler hang when attempting to optimize
     certain jump patterns.

   - bpo-45764(17): The parser now gives a better error message when
     leaving out the opening parenthesis ‘(’ after a ‘def’-statement:

          >>> def f:
            File "<stdin>", line 1
              def f:
                   ^
          SyntaxError: expected '('

   - bpo-45609(18): Specialized the ‘STORE_SUBSCR’ opcode using the PEP
     659 machinery.

   - bpo-45636(19): Replace all numeric ‘BINARY_*’ and ‘INPLACE_*’
     instructions with a single *note BINARY_OP: 366. implementation.

   - bpo-45582(20): Path calculation (known as ‘getpath’) has been
     reimplemented as a frozen Python module.  This should have no
     visible impact, but may affect calculation of all paths referenced
     in *note sys: df. and *note sysconfig: e1.

   - bpo-45450(21): Improve the syntax error message for parenthesized
     arguments.  Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45813

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45811

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45848

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45709

   (5) https://bugs.python.org/issue?@action=redirect&bpo=44525

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45829

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45826

   (8) https://bugs.python.org/issue?@action=redirect&bpo=45822

   (9) https://peps.python.org/pep-0263/

   (10) https://bugs.python.org/issue?@action=redirect&bpo=45820

   (11) https://bugs.python.org/issue?@action=redirect&bpo=45636

   (12) https://bugs.python.org/issue?@action=redirect&bpo=42540

   (13) https://bugs.python.org/issue?@action=redirect&bpo=45738

   (14) https://bugs.python.org/issue?@action=redirect&bpo=45636

   (15) https://bugs.python.org/issue?@action=redirect&bpo=45753

   (16) https://bugs.python.org/issue?@action=redirect&bpo=45773

   (17) https://bugs.python.org/issue?@action=redirect&bpo=45764

   (18) https://bugs.python.org/issue?@action=redirect&bpo=45609

   (19) https://bugs.python.org/issue?@action=redirect&bpo=45636

   (20) https://bugs.python.org/issue?@action=redirect&bpo=45582

   (21) https://bugs.python.org/issue?@action=redirect&bpo=45450


File: python.info,  Node: Library<104>,  Next: Documentation<33>,  Prev: Core and Builtins<101>,  Up: Python 3 11 0 alpha 3

1.24.39.4 Library
.................

   - bpo-27946(1): Fix possible crash when getting an attribute of *note
     xml.etree.ElementTree.Element: 363. simultaneously with replacing
     the ‘attrib’ dict.

   - bpo-45711(2): Make *note asyncio: b. normalize exceptions as soon
     as they are captured with *note PyErr_Fetch(): 428, and before they
     are stored as an exc_info triplet.  This brings *note asyncio: b.
     in line with the rest of the codebase, where an exc_info triplet is
     always normalized.

   - bpo-23819(3): Replaced asserts with exceptions in asyncio, patch by
     Kumar Aditya.

   - bpo-13236(4): *note unittest.TextTestResult: 755. and *note
     unittest.TextTestRunner: 1a9e. flush now the output stream more
     often.

   - bpo-45917(5): Added *note math.exp2(): 871.:, which returns 2
     raised to the power of x.

   - bpo-37658(6): Fix issue when on certain conditions
     ‘asyncio.wait_for()’ may allow a coroutine to complete
     successfully, but fail to return the result, potentially causing
     memory leaks or other issues.

   - bpo-45876(7): Improve the accuracy of stdev() and pstdev() in the
     statistics module.  When the inputs are floats or fractions, the
     output is a correctly rounded float

   - bpo-44649(8): Handle dataclass(slots=True) with a field that has
     default a default value, but for which init=False.

   - bpo-45803(9): Added missing kw_only parameter to
     dataclasses.make_dataclass().

   - bpo-45837(10): The ‘turtle.RawTurtle.settiltangle()’ is deprecated
     since Python 3.1, it now emits a deprecation warning and will be
     removed in Python 3.13.

     Use ‘turtle.RawTurtle.tiltangle()’ instead.

     ‘turtle.RawTurtle.tiltangle()’ was earlier incorrectly marked as
     deprecated, its docstring has been corrected.

     Patch by Hugo van Kemenade.

   - bpo-45831(11): *note faulthandler: 5c. can now write ASCII-only
     strings (like filenames and function names) with a single write()
     syscall when dumping a traceback.  It reduces the risk of getting
     an unreadable dump when two threads or two processes dump a
     traceback to the same file (like stderr) at the same time.  Patch
     by Victor Stinner.

   - bpo-45828(12): ‘sqlite’ C callbacks now use unraisable exceptions
     if callback tracebacks are enabled.  Patch by Erlend E. Aasland.

   - bpo-41735(13): Fix thread lock in ‘zlib.Decompress.flush()’ method
     before ‘PyObject_GetBuffer’.

   - bpo-45235(14): Reverted an argparse bugfix that caused regression
     in the handling of default arguments for subparsers.  This
     prevented leaf level arguments from taking precedence over root
     level arguments.

   - bpo-45754(15): Fix a regression in Python 3.11a1 and 3.11a2 where
     *note sqlite3: d4. incorrectly would use ‘SQLITE_LIMIT_LENGTH’ when
     checking SQL statement lengths.  Now, ‘SQLITE_LIMIT_SQL_LENGTH’ is
     used.  Patch by Erlend E. Aasland.

   - bpo-45766(16): Added 'proportional' option to *note
     statistics.linear_regression(): a34.

   - bpo-45765(17): In importlib.metadata, fix distribution discovery
     for an empty path.

   - bpo-45757(18): Fix bug where *note dis: 3c. produced an incorrect
     oparg when *note EXTENDED_ARG: 1b06. is followed by an opcode that
     does not use its argument.

   - bpo-45644(19): In-place JSON file formatting using ‘python3 -m
     json.tool infile infile’ now works correctly, previously it left
     the file empty.  Patch by Chris Wesseling.

   - bpo-45703(20): When a namespace package is imported before another
     module from the same namespace is created/installed in a different
     *note sys.path: 3e4. location while the program is running, calling
     the *note importlib.invalidate_caches(): e0c. function will now
     also guarantee the new module is noticed.

   - bpo-45535(21): Improve output of ‘dir()’ with Enums.

   - bpo-45664(22): Fix *note types.resolve_bases(): d97. and *note
     types.new_class(): 1369. for *note types.GenericAlias: 9ee.
     instance as a base.

   - bpo-45663(23): Fix *note dataclasses.is_dataclass(): 1bff. for
     dataclasses which are subclasses of *note types.GenericAlias: 9ee.

   - bpo-45662(24): Fix the repr of *note dataclasses.InitVar: 1b9c.
     with a type alias to the built-in class, e.g.
     ‘InitVar[list[int]]’.

   - bpo-43137(25): Launch GNOME web browsers via gio tool instead of
     obsolete gvfs-open

   - bpo-45429(26): On Windows, *note time.sleep(): 8ad. now uses a
     waitable timer which supports high-resolution timers.  Patch by
     Donghee Na and Eryk Sun.

   - bpo-37295(27): Optimize *note math.comb(): 8e0. and *note
     math.perm(): 8e1.

   - bpo-45514(28): Deprecated legacy functions in *note
     importlib.resources: 7f.

   - bpo-45507(29): Add tests for truncated/missing trailers in
     gzip.decompress implementation.

   - bpo-45359(30): Implement PEP 585(31) for *note
     graphlib.TopologicalSorter: ae0.

   - bpo-44733(32): Add ‘max_tasks_per_child’ to *note
     concurrent.futures.ProcessPoolExecutor: 1d6.  This allows users to
     specify the maximum number of tasks a single process should execute
     before the process needs to be restarted.

   - bpo-28806(33): Improve netrc library.  netrc file no longer needs
     to contain all tokens.  And if the login name is anonymous,
     security check is no longer need.

   - bpo-43498(34): Avoid a possible '«RuntimeError: dictionary changed
     size during iteration»' when adjusting the process count of
     ‘ProcessPoolExecutor’.

   - bpo-42158(35): Add MIME types for N-quads, N-triples, Notation3 and
     TriG to ‘mimetypes’.

   - bpo-30533(36): Add *note inspect.getmembers_static(): 85a. , it
     return all members without triggering dynamic lookup via the
     descriptor protocol.  Patch by Weipeng Hong.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27946

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45711

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23819

   (4) https://bugs.python.org/issue?@action=redirect&bpo=13236

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45917

   (6) https://bugs.python.org/issue?@action=redirect&bpo=37658

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45876

   (8) https://bugs.python.org/issue?@action=redirect&bpo=44649

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45803

   (10) https://bugs.python.org/issue?@action=redirect&bpo=45837

   (11) https://bugs.python.org/issue?@action=redirect&bpo=45831

   (12) https://bugs.python.org/issue?@action=redirect&bpo=45828

   (13) https://bugs.python.org/issue?@action=redirect&bpo=41735

   (14) https://bugs.python.org/issue?@action=redirect&bpo=45235

   (15) https://bugs.python.org/issue?@action=redirect&bpo=45754

   (16) https://bugs.python.org/issue?@action=redirect&bpo=45766

   (17) https://bugs.python.org/issue?@action=redirect&bpo=45765

   (18) https://bugs.python.org/issue?@action=redirect&bpo=45757

   (19) https://bugs.python.org/issue?@action=redirect&bpo=45644

   (20) https://bugs.python.org/issue?@action=redirect&bpo=45703

   (21) https://bugs.python.org/issue?@action=redirect&bpo=45535

   (22) https://bugs.python.org/issue?@action=redirect&bpo=45664

   (23) https://bugs.python.org/issue?@action=redirect&bpo=45663

   (24) https://bugs.python.org/issue?@action=redirect&bpo=45662

   (25) https://bugs.python.org/issue?@action=redirect&bpo=43137

   (26) https://bugs.python.org/issue?@action=redirect&bpo=45429

   (27) https://bugs.python.org/issue?@action=redirect&bpo=37295

   (28) https://bugs.python.org/issue?@action=redirect&bpo=45514

   (29) https://bugs.python.org/issue?@action=redirect&bpo=45507

   (30) https://bugs.python.org/issue?@action=redirect&bpo=45359

   (31) https://peps.python.org/pep-0585/

   (32) https://bugs.python.org/issue?@action=redirect&bpo=44733

   (33) https://bugs.python.org/issue?@action=redirect&bpo=28806

   (34) https://bugs.python.org/issue?@action=redirect&bpo=43498

   (35) https://bugs.python.org/issue?@action=redirect&bpo=42158

   (36) https://bugs.python.org/issue?@action=redirect&bpo=30533


File: python.info,  Node: Documentation<33>,  Next: Tests<33>,  Prev: Library<104>,  Up: Python 3 11 0 alpha 3

1.24.39.5 Documentation
.......................

   - bpo-42238(1): ‘make -C Doc suspicious’ will be removed soon in
     favor of ‘make -C Doc check’, mark it as deprecated.

   - bpo-45840(2): Improve cross-references in the documentation for the
     data model.

   - bpo-45640(3): Properly marked-up grammar tokens in the
     documentation are now clickable and take you to the definition of a
     given piece of grammar.  Patch by Arthur Milchior.

   - bpo-45788(4): Link doc for sys.prefix to sysconfig doc on
     installation paths.

   - bpo-45772(5): ‘socket.socket’ documentation is corrected to a class
     from a function.

   - bpo-45392(6): Update the docstring of the *note type: f46. built-in
     to remove a redundant line and to mention keyword arguments for the
     constructor.

   - bpo-45250(7): Update the documentation to note that CPython does
     not consistently require iterators to define ‘__iter__’.

   - bpo-25381(8): In the extending chapter of the extending doc, update
     a paragraph about the global variables containing exception
     information.

   - bpo-43905(9): Expanded *note astuple(): 1a86. and *note asdict():
     1a7d. docs, warning about deepcopy being applied and providing a
     workaround.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42238

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45840

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45640

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45788

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45772

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45392

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45250

   (8) https://bugs.python.org/issue?@action=redirect&bpo=25381

   (9) https://bugs.python.org/issue?@action=redirect&bpo=43905


File: python.info,  Node: Tests<33>,  Next: Build<40>,  Prev: Documentation<33>,  Up: Python 3 11 0 alpha 3

1.24.39.6 Tests
...............

   - bpo-45695(1): Out-of-tree builds with a read-only source directory
     are now tested by CI.

   - bpo-19460(2): Add new Test for
     ‘Lib/email/mime/nonmultipart.py::MIMENonMultipart’.

   - bpo-45835(3): Fix race condition in test_queue tests with multiple
     «feeder» threads.

   - bpo-45783(4): The test for the freeze tool now handles file moves
     and deletions.

   - bpo-45745(5): Remove the ‘--findleaks’ command line option of
     regrtest: use the ‘--fail-env-changed’ option instead.  Since
     Python 3.7, it was a deprecated alias to the ‘--fail-env-changed’
     option.

   - bpo-45701(6): Add tests with ‘tuple’ type with *note
     functools.lru_cache(): be4. to ‘test_functools’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45695

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19460

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45835

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45783

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45745

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45701


File: python.info,  Node: Build<40>,  Next: Windows<34>,  Prev: Tests<33>,  Up: Python 3 11 0 alpha 3

1.24.39.7 Build
...............

   - bpo-44035(1): CI now verifies that autoconf files have been
     regenerated with a current and unpatched autoconf package.

   - bpo-45950(2): The build system now uses a ‘_bootstrap_python’
     interpreter for freezing and deepfreezing again.  To speed up build
     process the build tools ‘_bootstrap_python’ and ‘_freeze_module’
     are no longer build with LTO.

   - bpo-45881(3): The ‘configure’ script now accepts
     ‘--with-build-python’ and ‘--with-freeze-module’ options to make
     cross compiling easier.

   - bpo-40280(4): Emscripten platform now uses ‘.wasm’ suffix by
     default.

   - bpo-40280(5): Disable unusable core extension modules on
     WASM/Emscripten targets.

   - bpo-40280(6): ‘configure’ now checks for socket ‘shutdown’
     function.  The check makes it possible to disable ‘SYS_shutdown’
     with ‘ac_cv_func_shutdown=no’ in CONFIG_SITE.

   - bpo-40280(7): ‘configure’ now checks for functions ‘fork1, getegid,
     geteuid, getgid, getppid, getuid, opendir, pipe, system, wait,
     ttyname’.

   - bpo-33393(8): Update ‘config.guess’ to 2021-06-03 and ‘config.sub’
     to 2021-08-14.  ‘Makefile’ now has an ‘update-config’ target to
     make updating more convenient.

   - bpo-45866(9): ‘make regen-all’ now produces the same output when
     run from a directory other than the source tree: when building
     Python out of the source tree.  pegen now strips directory of the
     «generated by pygen from <FILENAME>» header Patch by Victor
     Stinner.

   - bpo-40280(10): ‘configure’ now accepts machine ‘wasm32’ or ‘wasm64’
     and OS ‘wasi’ or ‘emscripten’ for cross building, e.g.
     ‘wasm32-unknown-emscripten’, ‘wasm32-wasi’, or
     ‘wasm32-unknown-wasi’.

   - bpo-41498(11): Python now compiles on platforms without ‘sigset_t’.
     Several functions in *note signal: cb. are not available when
     ‘sigset_t’ is missing.

     Based on patch by Roman Yurchak for pyodide.

   - bpo-45881(12): ‘setup.py’ now uses ‘CC’ from environment first to
     discover multiarch and cross compile paths.

   - bpo-45886(13): The ‘_freeze_module’ program path can now be
     overridden on the command line, e.g.  ‘make
     FREEZE_MODULE=../x86_64/Program/_freeze_module’.

   - bpo-45873(14): Get rid of the ‘_bootstrap_python’ build step.  The
     deepfreeze.py script is now run using ‘$(PYTHON_FOR_REGEN)’ which
     can be Python 3.7 or newer (on Windows, 3.8 or newer).

   - bpo-45847(15): Port builtin hashlib extensions to ‘PY_STDLIB_MOD’
     macro and ‘addext()’.

   - bpo-45723(16): Add ‘autoconf’ helpers for saving and restoring
     environment variables:

        * ‘SAVE_ENV’: Save ‘$CFLAGS’, ‘$LDFLAGS’, ‘$LIBS’, and
          ‘$CPPFLAGS’.

        * ‘RESTORE_ENV’: Restore ‘$CFLAGS’, ‘$LDFLAGS’, ‘$LIBS’, and
          ‘$CPPFLAGS’.

        * ‘WITH_SAVE_ENV([SCRIPT])’: Run ‘SCRIPT’ wrapped with
          ‘SAVE_ENV’ and ‘RESTORE_ENV’.

     Patch by Erlend E. Aasland.

   - bpo-45573(17): Mandatory core modules, that are required to
     bootstrap Python, are now in ‘Modules/Setup.bootstrap’.

   - bpo-45573(18): ‘configure’ now creates ‘Modules/Setup.stdlib’ with
     conditionally enabled/disabled extension module lines.  The file is
     not used, yet.

   - bpo-45573(19): ‘configure’ now uses a unified format to set state,
     compiler flags, and linker flags in Makefile.  The new macro
     ‘PY_STDLIB_MOD’ sets three variables that are consumed by
     ‘Modules/Setup’ and ‘setup.py’.

   - bpo-45816(20): Python now supports building with Visual Studio 2022
     (MSVC v143, VS Version 17.0).  Patch by Jeremiah Vivian.

   - bpo-45800(21): Settings for ‘pyexpat’ C extension are now detected
     by ‘configure’.  The bundled ‘expat’ library is built in
     ‘Makefile’.

   - bpo-45798(22): Settings for *note decimal: 3a. internal C extension
     are now detected by ‘configure’.  The bundled ‘libmpdec’ library is
     built in ‘Makefile’.

   - bpo-45723(23): ‘configure’ has a new option ‘--with-pkg-config’ to
     disable or require pkg-config.

   - bpo-45774(24): The build dependencies for *note sqlite3: d4. are
     now detected by ‘configure’ and ‘pkg-config’.  Patch by Erlend E.
     Aasland.

   - bpo-45763(25): The build dependencies for *note zlib: 139, *note
     bz2: 14, and *note lzma: 8e. are now detected by ‘configure’.

   - bpo-45747(26): gdbm and dbm build dependencies are now detected by
     ‘configure’.

   - bpo-45743(27): On macOS, the build system no longer passes
     ‘search_paths_first’ to the linker.  The flag has been the default
     since Xcode 4 / macOS 10.6.

   - bpo-45723(28): ‘configure.ac’ is now compatible with autoconf 2.71.
     Deprecated checks ‘STDC_HEADERS’ and ‘AC_HEADER_TIME’ have been
     removed.

   - bpo-45723(29): ‘configure’ now prints a warning when pkg-config is
     missing.

   - bpo-45731(30): ‘configure --enable-loadable-sqlite-extensions’ is
     now handled by new ‘PY_SQLITE_ENABLE_LOAD_EXTENSION’ macro instead
     of logic in setup.py.

   - bpo-45723(31): configure.ac now uses custom helper macros and
     ‘AC_CACHE_CHECK’ to simplify and speed up configure runs.

   - bpo-45696(32): Skip the marshal step for frozen modules by
     generating C code that produces a set of ready-to-use code objects.
     This speeds up startup time by another 10% or more.

   - bpo-45561(33): Run smelly.py tool from $(srcdir).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44035

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45950

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45881

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (8) https://bugs.python.org/issue?@action=redirect&bpo=33393

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45866

   (10) https://bugs.python.org/issue?@action=redirect&bpo=40280

   (11) https://bugs.python.org/issue?@action=redirect&bpo=41498

   (12) https://bugs.python.org/issue?@action=redirect&bpo=45881

   (13) https://bugs.python.org/issue?@action=redirect&bpo=45886

   (14) https://bugs.python.org/issue?@action=redirect&bpo=45873

   (15) https://bugs.python.org/issue?@action=redirect&bpo=45847

   (16) https://bugs.python.org/issue?@action=redirect&bpo=45723

   (17) https://bugs.python.org/issue?@action=redirect&bpo=45573

   (18) https://bugs.python.org/issue?@action=redirect&bpo=45573

   (19) https://bugs.python.org/issue?@action=redirect&bpo=45573

   (20) https://bugs.python.org/issue?@action=redirect&bpo=45816

   (21) https://bugs.python.org/issue?@action=redirect&bpo=45800

   (22) https://bugs.python.org/issue?@action=redirect&bpo=45798

   (23) https://bugs.python.org/issue?@action=redirect&bpo=45723

   (24) https://bugs.python.org/issue?@action=redirect&bpo=45774

   (25) https://bugs.python.org/issue?@action=redirect&bpo=45763

   (26) https://bugs.python.org/issue?@action=redirect&bpo=45747

   (27) https://bugs.python.org/issue?@action=redirect&bpo=45743

   (28) https://bugs.python.org/issue?@action=redirect&bpo=45723

   (29) https://bugs.python.org/issue?@action=redirect&bpo=45723

   (30) https://bugs.python.org/issue?@action=redirect&bpo=45731

   (31) https://bugs.python.org/issue?@action=redirect&bpo=45723

   (32) https://bugs.python.org/issue?@action=redirect&bpo=45696

   (33) https://bugs.python.org/issue?@action=redirect&bpo=45561


File: python.info,  Node: Windows<34>,  Next: macOS<24>,  Prev: Build<40>,  Up: Python 3 11 0 alpha 3

1.24.39.8 Windows
.................

   - bpo-46105(1): Fixed calculation of *note sys.path: 3e4. in a venv
     on Windows.

   - bpo-45901(2): When installed through the Microsoft Store and set as
     the default app for ‘*.py’ files, command line arguments will now
     be passed to Python when invoking a script without explicitly
     launching Python (that is, ‘script.py args’ rather than ‘python
     script.py args’).

   - bpo-45616(3): Fix Python Launcher’s ability to distinguish between
     versions 3.1 and 3.10 when either one is explicitly requested.
     Previously, 3.1 would be used if 3.10 was requested but not
     installed, and 3.10 would be used if 3.1 was requested but 3.10 was
     installed.

   - bpo-45850(4): Implement changes to build with deep-frozen modules
     on Windows.  Note that we now require Python 3.10 as the
     «bootstrap» or «host» Python.

   - bpo-45732(5): Updates bundled Tcl/Tk to 8.6.12.

   - bpo-45720(6): Internal reference to ‘shlwapi.dll’ was dropped to
     help improve startup time.  This DLL will no longer be loaded at
     the start of every Python process.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=46105

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45901

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45616

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45850

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45732

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45720


File: python.info,  Node: macOS<24>,  Next: C API<35>,  Prev: Windows<34>,  Up: Python 3 11 0 alpha 3

1.24.39.9 macOS
...............

   - bpo-45732(1): Update python.org macOS installer to use Tcl/Tk
     8.6.12.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45732


File: python.info,  Node: C API<35>,  Prev: macOS<24>,  Up: Python 3 11 0 alpha 3

1.24.39.10 C API
................

   - bpo-39026(1): Fix Python.h to build C extensions with Xcode: remove
     a relative include from ‘Include/cpython/pystate.h’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39026


File: python.info,  Node: Python 3 11 0 alpha 2,  Next: Python 3 11 0 alpha 1,  Prev: Python 3 11 0 alpha 3,  Up: Changelog

1.24.40 Python 3.11.0 alpha 2
-----------------------------

'Release date: 2021-11-05'

* Menu:

* Core and Builtins: Core and Builtins<102>.
* Library: Library<105>.
* Documentation: Documentation<34>.
* Tests: Tests<34>.
* Build: Build<41>.
* Windows: Windows<35>.
* macOS: macOS<25>.
* IDLE: IDLE<18>.
* C API: C API<36>.


File: python.info,  Node: Core and Builtins<102>,  Next: Library<105>,  Up: Python 3 11 0 alpha 2

1.24.40.1 Core and Builtins
...........................

   - bpo-45716(1): Improve the *note SyntaxError: 18e. message when
     using ‘True’, ‘None’ or ‘False’ as keywords in a function call.
     Patch by Pablo Galindo.

   - bpo-45688(2): *note sys.stdlib_module_names: a44. now contains the
     macOS-specific module ‘_scproxy’.

   - bpo-45379(3): Clarify *note ImportError: 65b. message when we try
     to explicitly import a frozen module but frozen modules are
     disabled.

   - bpo-44525(4): Specialize simple calls to Python functions (no
     starargs, keyword dict, or closure)

   - bpo-45530(5): Cases of sorting using tuples as keys may now be
     significantly faster in some cases.  Patch by Tim Peters.

     The order of the result may differ from earlier releases if the
     tuple elements don’t define a total ordering (see *note Value
     comparisons: 1c08. for information on total ordering).  It’s
     generally true that the result of sorting simply isn’t well-defined
     in the absence of a total ordering on list elements.

   - bpo-45526(6): In obmalloc, set ADDRESS_BITS to not ignore any bits
     (ignored 16 before).  That is safer in the case that the kernel
     gives user-space virtual addresses that span a range greater than
     48 bits.

   - bpo-30570(7): Fixed a crash in ‘issubclass()’ from infinite
     recursion when searching pathological ‘__bases__’ tuples.

   - bpo-45521(8): Fix a bug in the obmalloc radix tree code.  On 64-bit
     machines, the bug causes the tree to hold 46-bits of virtual
     addresses, rather than the intended 48-bits.

   - bpo-45494(9): Fix parser crash when reporting errors involving
     invalid continuation characters.  Patch by Pablo Galindo.

   - bpo-45445(10): Python now fails to initialize if it finds an
     invalid *note -X: 16f. option in the command line.  Patch by Pablo
     Galindo.

   - bpo-45340(11): Object attributes are held in an array instead of a
     dictionary.  An object’s dictionary are created lazily, only when
     needed.  Reduces the memory consumption of a typical Python object
     by about 30%.  Patch by Mark Shannon.

   - bpo-45408(12): Fix a crash in the parser when reporting tokenizer
     errors that occur at the same time unclosed parentheses are
     detected.  Patch by Pablo Galindo.

   - bpo-29410(13): Add SipHash13 for string hash algorithm and use it
     by default.

   - bpo-45385(14): Fix reference leak from descr_check.  Patch by
     Donghee Na.

   - bpo-45367(15): Specialized the ‘BINARY_MULTIPLY’ opcode to
     ‘BINARY_MULTIPLY_INT’ and ‘BINARY_MULTIPLY_FLOAT’ using the PEP 659
     machinery.

   - bpo-21736(16): Frozen stdlib modules now have ‘__file__’ to the .py
     file they would otherwise be loaded from, if possible.  For
     packages, ‘__path__’ now has the correct entry instead of being an
     empty list, which allows unfrozen submodules to be imported.  These
     are set only if the stdlib directory is known when the runtime is
     initialized.  Note that the file at ‘__file__’ is not guaranteed to
     exist.  None of this affects non-stdlib frozen modules nor, for
     now, frozen modules imported using ‘PyImport_ImportFrozenModule()’.
     Also, at the moment ‘co_filename’ is not updated for the module.

   - bpo-45020(17): For frozen stdlib modules, record the original
     module name as ‘module.__spec__.loader_state.origname’.  If the
     value is different than ‘module.__spec__.name’ then the module was
     defined as an alias in Tools/scripts/freeze_modules.py.  If it is
     ‘None’ then the module comes from a source file outside the stdlib.

   - bpo-45324(18): In FrozenImporter.find_spec(), we now preserve the
     information needed in exec_module() to load the module.  This
     change mostly impacts internal details, rather than changing the
     importer’s behavior.

   - bpo-45292(19): Implement PEP 654(20).  Add *note ExceptionGroup:
     4d3. and *note BaseExceptionGroup: 566.  Update traceback display
     code.

   - bpo-40116(21): Change to the implementation of split dictionaries.
     Classes where the instances differ either in the exact set of
     attributes, or in the order in which those attributes are set, can
     still share keys.  This should have no observable effect on users
     of Python or the C-API. Patch by Mark Shannon.

   - bpo-44050(22): Extensions that indicate they use global state (by
     setting ‘m_size’ to -1) can again be used in multiple interpreters.
     This reverts to behavior of Python 3.8.

   - bpo-44525(23): Setup initial specialization infrastructure for the
     ‘CALL_FUNCTION’ opcode.  Implemented initial specializations for C
     function calls:

        * ‘CALL_FUNCTION_BUILTIN_O’ for ‘METH_O’ flag.

        * ‘CALL_FUNCTION_BUILTIN_FAST’ for ‘METH_FASTCALL’ flag without
          keywords.

        * ‘CALL_FUNCTION_LEN’ for ‘len(o)’.

        * ‘CALL_FUNCTION_ISINSTANCE’ for ‘isinstance(o, t)’.

   - bpo-44511(24): Improve the generated bytecode for class and mapping
     patterns.

   - bpo-43706(25): Speed up calls to ‘enumerate()’ by using the PEP
     590(26) ‘vectorcall’ calling convention.  Patch by Donghee Na.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45716

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45688

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45379

   (4) https://bugs.python.org/issue?@action=redirect&bpo=44525

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45530

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45526

   (7) https://bugs.python.org/issue?@action=redirect&bpo=30570

   (8) https://bugs.python.org/issue?@action=redirect&bpo=45521

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45494

   (10) https://bugs.python.org/issue?@action=redirect&bpo=45445

   (11) https://bugs.python.org/issue?@action=redirect&bpo=45340

   (12) https://bugs.python.org/issue?@action=redirect&bpo=45408

   (13) https://bugs.python.org/issue?@action=redirect&bpo=29410

   (14) https://bugs.python.org/issue?@action=redirect&bpo=45385

   (15) https://bugs.python.org/issue?@action=redirect&bpo=45367

   (16) https://bugs.python.org/issue?@action=redirect&bpo=21736

   (17) https://bugs.python.org/issue?@action=redirect&bpo=45020

   (18) https://bugs.python.org/issue?@action=redirect&bpo=45324

   (19) https://bugs.python.org/issue?@action=redirect&bpo=45292

   (20) https://peps.python.org/pep-0654/

   (21) https://bugs.python.org/issue?@action=redirect&bpo=40116

   (22) https://bugs.python.org/issue?@action=redirect&bpo=44050

   (23) https://bugs.python.org/issue?@action=redirect&bpo=44525

   (24) https://bugs.python.org/issue?@action=redirect&bpo=44511

   (25) https://bugs.python.org/issue?@action=redirect&bpo=43706

   (26) https://peps.python.org/pep-0590/


File: python.info,  Node: Library<105>,  Next: Documentation<34>,  Prev: Core and Builtins<102>,  Up: Python 3 11 0 alpha 2

1.24.40.2 Library
.................

   - bpo-45679(1): Fix caching of multi-value *note typing.Literal: a57.
     ‘Literal[True, 2]’ is no longer equal to ‘Literal[1, 2]’.

   - bpo-42064(2): Convert *note sqlite3: d4. to multi-phase
     initialisation (PEP 489).  Patches by Erlend E. Aasland.

   - bpo-45438(3): Fix typing.Signature string representation for
     generic builtin types.

   - bpo-45613(4): *note sqlite3: d4. now sets *note
     sqlite3.threadsafety: 88d. based on the default threading mode the
     underlying SQLite library has been compiled with.  Patch by Erlend
     E. Aasland.

   - bpo-45574(5): Fix warning about ‘print_escape’ being unused.

   - bpo-45581(6): *note sqlite3.connect(): 5a6. now correctly raises
     *note MemoryError: 1786. if the underlying SQLite API signals
     memory error.  Patch by Erlend E. Aasland.

   - bpo-45557(7): *note pprint.pprint(): a2b. now handles
     'underscore_numbers' correctly.  Previously it was always setting
     it to ‘False’.

   - bpo-44019(8): Add *note operator.call(): 1c0a. to
     ‘operator.__all__’.  Patch by Kreusada.

   - bpo-42174(9): *note shutil.get_terminal_size(): 130b. now falls
     back to sane values if the column or line count are 0.

   - bpo-35673(10): Improve the introspectability of the ‘__loader__’
     attribute for namespace packages.  *note
     importlib.machinery.NamespaceLoader: 1158. is now public, and
     implements the *note importlib.abc.InspectLoader: 1156. interface.
     ‘_NamespaceLoader’ is kept for backward compatibility.

   - bpo-45515(11): Add references to *note zoneinfo: 13a. in the *note
     datetime: 34. documentation, mostly replacing outdated references
     to ‘dateutil.tz’.  Change by Paul Ganssle.

   - bpo-45475(12): Reverted optimization of iterating *note
     gzip.GzipFile: 65c, *note bz2.BZ2File: a68, and *note
     lzma.LZMAFile: 120e. (see bpo-43787(13)) because it caused
     regression when user iterate them without having reference of them.
     Patch by Inada Naoki.

   - bpo-45489(14): Update *note ForwardRef: 1bc2. to support ‘|’
     operator.  Patch by Donghee Na.

   - bpo-42222(15): Removed deprecated support for float arguments in
     'randrange()'.

   - bpo-45428(16): Fix a regression in py_compile when reading
     filenames from standard input.

   - bpo-45467(17): Fix incremental decoder and stream reader in the
     «raw-unicode-escape» codec.  Previously they failed if the escape
     sequence was split.

   - bpo-45461(18): Fix incremental decoder and stream reader in the
     «unicode-escape» codec.  Previously they failed if the escape
     sequence was split.

   - bpo-45239(19): Fixed *note email.utils.parsedate_tz(): 1c0b.
     crashing with *note UnboundLocalError: 173d. on certain invalid
     input instead of returning ‘None’.  Patch by Ben Hoyt.

   - bpo-45417(20): Fix quadratic behaviour in the enum module: Creation
     of enum classes with a lot of entries was quadratic.

   - bpo-45249(21): Fix the behaviour of *note traceback.print_exc():
     1c0c. when displaying the caret when the ‘end_offset’ in the
     exception is set to 0.  Patch by Pablo Galindo

   - bpo-45416(22): Fix use of *note asyncio.Condition: c69. with
     explicit *note asyncio.Lock: c68. objects, which was a regression
     due to removal of explicit loop arguments.  Patch by Joongi Kim.

   - bpo-20028(23): Empty escapechar/quotechar is not allowed when
     initializing *note csv.Dialect: 180f.  Patch by Vajrasky Kok and
     Donghee Na.

   - bpo-44904(24): Fix bug in the *note doctest: 3e. module that caused
     it to fail if a docstring included an example with a ‘classmethod’
     ‘property’.  Patch by Alex Waygood.

   - bpo-45406(25): Make *note inspect.getmodule(): 1b55. catch
     ‘FileNotFoundError’ raised by ‘inspect.getabsfile()’, and return
     ‘None’ to indicate that the module could not be determined.

   - bpo-45411(26): Add extensions for files containing subtitles - .srt
     & .vtt - to the mimetypes.py module.

   - bpo-10716(27): Migrated pydoc to HTML5 (without changing the look
     of it).  Side effect is to update xmlrpc’s ‘ServerHTMLDoc’ which
     now uses the CSS too.  cgitb now relies less on pydoc (as it can’t
     use the CSS file).

   - bpo-27580(28): Add support of null characters in *note csv: 2d.

   - bpo-45262(29): Prevent use-after-free in asyncio.  Make sure the
     cached running loop holder gets cleared on dealloc to prevent
     use-after-free in get_running_loop

   - bpo-45386(30): Make *note xmlrpc.client: 134. more robust to C
     runtimes where the underlying C ‘strftime’ function results in a
     ‘ValueError’ when testing for year formatting options.

   - bpo-20028(31): Improve error message of *note csv.Dialect: 180f.
     when initializing.  Patch by Vajrasky Kok and Donghee Na.

   - bpo-45343(32): Update bundled pip to 21.2.4 and setuptools to
     58.1.0

   - bpo-45328(33): Fixed *note http.client.HTTPConnection: d37. to work
     properly in OSs that don’t support the ‘TCP_NODELAY’ socket option.

   - bpo-45243(34): Add *note setlimit(): 88b. and *note getlimit():
     88c. to *note sqlite3.Connection: 54e. for setting and getting
     SQLite limits by connection basis.  Patch by Erlend E. Aasland.

   - bpo-45320(35): Removed from the *note inspect: 82. module:

        * 
          the ‘getargspec’ function, deprecated since Python 3.0;

               use *note inspect.signature(): 22f. or *note
               inspect.getfullargspec(): 942. instead.

        * the ‘formatargspec’ function, deprecated since Python 3.5; use
          the *note inspect.signature(): 22f. function and ‘Signature’
          object directly.

        * the undocumented ‘Signature.from_builtin’ and
          ‘Signature.from_function’ functions, deprecated since Python
          3.5; use the *note Signature.from_callable(): 943. method
          instead.

     Patch by Hugo van Kemenade.

   - bpo-45192(36): Fix the ‘tempfile._infer_return_type’ function so
     that the ‘dir’ argument of the *note tempfile: e6. functions
     accepts an object implementing the ‘os.PathLike’ protocol.

     Patch by Kyungmin Lee.

   - bpo-45160(37): When tracing a tkinter variable used by a ttk
     OptionMenu, callbacks are no longer made twice.

   - bpo-25625(38): Added non parallel-safe *note chdir(): 821. context
     manager to change the current working directory and then restore it
     on exit.  Simple wrapper around *note chdir(): 822.

   - bpo-24139(39): Add support for SQLite extended result codes in
     *note sqlite3.Error: 1c0d.  Patch by Erlend E. Aasland.

   - bpo-24444(40): Fixed an error raised in *note argparse: 7. help
     display when help for an option is set to 1+ blank spaces or when
     'choices' arg is an empty container.

   - bpo-44547(41): Implement ‘Fraction.__int__’, so that a *note
     fractions.Fraction: 213. instance ‘f’ passes an ‘isinstance(f,
     typing.SupportsInt)’ check.

   - bpo-40321(42): Adds support for HTTP 308 redirects to *note urllib:
     10e.  See RFC 7538(43) for details.  Patch by Jochem
     Schulenklopper.

   - bpo-41374(44): Ensure that ‘socket.TCP_*’ constants are exposed on
     Cygwin 3.1.6 and greater.

   - bpo-35970(45): Add help flag to the base64 module’s command line
     interface.  Patch contributed by Robert Kuska.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45679

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42064

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45438

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45613

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45574

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45581

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45557

   (8) https://bugs.python.org/issue?@action=redirect&bpo=44019

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42174

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35673

   (11) https://bugs.python.org/issue?@action=redirect&bpo=45515

   (12) https://bugs.python.org/issue?@action=redirect&bpo=45475

   (13) https://bugs.python.org/issue?@action=redirect&bpo=43787

   (14) https://bugs.python.org/issue?@action=redirect&bpo=45489

   (15) https://bugs.python.org/issue?@action=redirect&bpo=42222

   (16) https://bugs.python.org/issue?@action=redirect&bpo=45428

   (17) https://bugs.python.org/issue?@action=redirect&bpo=45467

   (18) https://bugs.python.org/issue?@action=redirect&bpo=45461

   (19) https://bugs.python.org/issue?@action=redirect&bpo=45239

   (20) https://bugs.python.org/issue?@action=redirect&bpo=45417

   (21) https://bugs.python.org/issue?@action=redirect&bpo=45249

   (22) https://bugs.python.org/issue?@action=redirect&bpo=45416

   (23) https://bugs.python.org/issue?@action=redirect&bpo=20028

   (24) https://bugs.python.org/issue?@action=redirect&bpo=44904

   (25) https://bugs.python.org/issue?@action=redirect&bpo=45406

   (26) https://bugs.python.org/issue?@action=redirect&bpo=45411

   (27) https://bugs.python.org/issue?@action=redirect&bpo=10716

   (28) https://bugs.python.org/issue?@action=redirect&bpo=27580

   (29) https://bugs.python.org/issue?@action=redirect&bpo=45262

   (30) https://bugs.python.org/issue?@action=redirect&bpo=45386

   (31) https://bugs.python.org/issue?@action=redirect&bpo=20028

   (32) https://bugs.python.org/issue?@action=redirect&bpo=45343

   (33) https://bugs.python.org/issue?@action=redirect&bpo=45328

   (34) https://bugs.python.org/issue?@action=redirect&bpo=45243

   (35) https://bugs.python.org/issue?@action=redirect&bpo=45320

   (36) https://bugs.python.org/issue?@action=redirect&bpo=45192

   (37) https://bugs.python.org/issue?@action=redirect&bpo=45160

   (38) https://bugs.python.org/issue?@action=redirect&bpo=25625

   (39) https://bugs.python.org/issue?@action=redirect&bpo=24139

   (40) https://bugs.python.org/issue?@action=redirect&bpo=24444

   (41) https://bugs.python.org/issue?@action=redirect&bpo=44547

   (42) https://bugs.python.org/issue?@action=redirect&bpo=40321

   (43) https://datatracker.ietf.org/doc/html/rfc7538.html

   (44) https://bugs.python.org/issue?@action=redirect&bpo=41374

   (45) https://bugs.python.org/issue?@action=redirect&bpo=35970


File: python.info,  Node: Documentation<34>,  Next: Tests<34>,  Prev: Library<105>,  Up: Python 3 11 0 alpha 2

1.24.40.3 Documentation
.......................

   - bpo-45726(1): Improve documentation for *note
     functools.singledispatch(): 84c. and *note
     functools.singledispatchmethod: be5.

   - bpo-45680(2): Amend the docs on ‘GenericAlias’ objects to clarify
     that non-container classes can also implement ‘__class_getitem__’.
     Patch contributed by Alex Waygood.

   - bpo-45618(3): Update Sphinx version used to build the documentation
     to 4.2.0.  Patch by Maciej Olko.

   - bpo-45655(4): Add a new «relevant PEPs» section to the top of the
     documentation for the ‘typing’ module.  Patch by Alex Waygood.

   - bpo-45604(5): Add ‘level’ argument to
     ‘multiprocessing.log_to_stderr’ function docs.

   - bpo-45516(6): Add protocol description to the
     ‘importlib.abc.TraversableResources’ documentation.

   - bpo-45464(7): Mention in the documentation of *note Built-in
     Exceptions: 1c0f. that inheriting from multiple exception types in
     a single subclass is not recommended due to possible memory layout
     incompatibility.

   - bpo-45449(8): Add note about PEP 585(9) in *note collections.abc:
     1f.

   - bpo-45516(10): Add protocol description to the
     ‘importlib.abc.Traversable’ documentation.

   - bpo-20692(11): Add Programming FAQ entry explaining that int
     literal attribute access requires either a space after or
     parentheses around the literal.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45726

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45680

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45618

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45655

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45604

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45516

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45464

   (8) https://bugs.python.org/issue?@action=redirect&bpo=45449

   (9) https://peps.python.org/pep-0585/

   (10) https://bugs.python.org/issue?@action=redirect&bpo=45516

   (11) https://bugs.python.org/issue?@action=redirect&bpo=20692


File: python.info,  Node: Tests<34>,  Next: Build<41>,  Prev: Documentation<34>,  Up: Python 3 11 0 alpha 2

1.24.40.4 Tests
...............

   - bpo-45678(1): Add tests for scenarios in which *note
     functools.singledispatchmethod: be5. is stacked on top of a method
     that has already been wrapped by two other decorators.  Patch by
     Alex Waygood.

   - bpo-45578(2): Add tests for *note dis.distb(): 206.

   - bpo-45678(3): Add tests to ensure that
     ‘functools.singledispatchmethod’ correctly wraps the attributes of
     the target function.

   - bpo-45668(4): PGO tests now pass when Python is built without test
     extension modules.

   - bpo-45577(5): Add subtests for all ‘pickle’ protocols in
     ‘test_zoneinfo’.

   - bpo-45566(6): Fix ‘test_frozen_pickle’ in ‘test_dataclasses’ to
     check all ‘pickle’ versions.

   - bpo-43592(7): ‘test.libregrtest’ now raises the soft resource limit
     for the maximum number of file descriptors when the default is too
     low for our test suite as was often the case on macOS.

   - bpo-39679(8): Add more test cases for
     ‘@functools.singledispatchmethod’ when combined with ‘@classmethod’
     or ‘@staticmethod’.

   - bpo-45410(9): When libregrtest spawns a worker process, stderr is
     now written into stdout to keep messages order.  Use a single pipe
     for stdout and stderr, rather than two pipes.  Previously, messages
     were out of order which made analysis of buildbot logs harder Patch
     by Victor Stinner.

   - bpo-45402(10): Fix test_tools.test_sundry() when Python is built
     out of tree: fix how the freeze_modules.py tool locates the
     _freeze_module program.  Patch by Victor Stinner.

   - bpo-45403(11): Fix test_sys.test_stdlib_dir() when Python is built
     outside the source tree: compare normalized paths.  Patch by Victor
     Stinner.

   - bpo-45400(12): Fix
     test_name_error_suggestions_do_not_trigger_for_too_many_locals() of
     test_exceptions if a directory name contains «a1» (like
     «Python-3.11.0a1»): use a stricter regular expression.  Patch by
     Victor Stinner.

   - bpo-10572(13): Rename *note sqlite3: d4. tests from ‘test_sqlite’
     to ‘test_sqlite3’, and relocate them to ‘Lib/test/test_sqlite3’.
     Patch by Erlend E. Aasland.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45678

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45578

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45678

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45668

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45577

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45566

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43592

   (8) https://bugs.python.org/issue?@action=redirect&bpo=39679

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45410

   (10) https://bugs.python.org/issue?@action=redirect&bpo=45402

   (11) https://bugs.python.org/issue?@action=redirect&bpo=45403

   (12) https://bugs.python.org/issue?@action=redirect&bpo=45400

   (13) https://bugs.python.org/issue?@action=redirect&bpo=10572


File: python.info,  Node: Build<41>,  Next: Windows<35>,  Prev: Tests<34>,  Up: Python 3 11 0 alpha 2

1.24.40.5 Build
...............

   - bpo-43158(1): ‘setup.py’ now uses values from configure script to
     build the ‘_uuid’ extension module.  Configure now detects
     util-linux’s ‘libuuid’, too.

   - bpo-45666(2): Fix warning of ‘swprintf’ and ‘%s’ usage in
     ‘_testembed.c’

   - bpo-45548(3): ‘Modules/Setup’ and ‘Modules/makesetup’ have been
     improved.  The ‘Setup’ file now contains working rules for all
     extensions.  Outdated comments have been removed.  Rules defined by
     ‘makesetup’ track dependencies correctly.

   - bpo-45548(4): The *note math: 92. and *note cmath: 19.
     implementation now require a C99 compatible ‘libm’ and no longer
     ship with workarounds for missing acosh, asinh, atanh, expm1, and
     log1p functions.

   - bpo-45595(5): ‘setup.py’ and ‘makesetup’ now track build
     dependencies on all Python header files and module specific header
     files.

   - bpo-45571(6): ‘Modules/Setup’ now use ‘PY_CFLAGS_NODIST’ instead of
     ‘PY_CFLAGS’ to compile shared modules.

   - bpo-45570(7): ‘pyexpat’ and ‘_elementtree’ no longer define
     obsolete macros ‘HAVE_EXPAT_CONFIG_H’ and ‘USE_PYEXPAT_CAPI’.
     ‘XML_POOR_ENTROPY’ is now defined in ‘expat_config.h’.

   - bpo-43974(8): ‘setup.py’ no longer defines ‘Py_BUILD_CORE_MODULE’.
     Instead every module, that uses the internal API, defines the
     macro.

   - bpo-45548(9): Fill in missing entries in Modules/Setup.

   - bpo-45532(10): Update *note sys.version: 49d. to use ‘main’ as
     fallback information.  Patch by Jeong YunWon.

   - bpo-45536(11): The ‘configure’ script now checks whether OpenSSL
     headers and libraries provide required APIs.  Most common APIs are
     verified.  The check detects outdated or missing OpenSSL. Failures
     do not stop configure.

   - bpo-45221(12): Fixed regression in handling of ‘LDFLAGS’ and
     ‘CPPFLAGS’ options where ‘argparse.parse_known_args()’ could
     interpret an option as one of the built-in command line argument,
     for example ‘-h’ for help.

   - bpo-45440(13): Building Python now requires a C99 ‘<math.h>’ header
     file providing the following functions: ‘copysign()’, ‘hypot()’,
     ‘isfinite()’, ‘isinf()’, ‘isnan()’, ‘round()’.  Patch by Victor
     Stinner.

   - bpo-45405(14): Prevent ‘internal configure error’ when running
     ‘configure’ with recent versions of non-Apple clang.  Patch by
     David Bohman.

   - bpo-45433(15): Avoid linking libpython with libcrypt.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43158

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45666

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45548

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45548

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45595

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45571

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45570

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43974

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45548

   (10) https://bugs.python.org/issue?@action=redirect&bpo=45532

   (11) https://bugs.python.org/issue?@action=redirect&bpo=45536

   (12) https://bugs.python.org/issue?@action=redirect&bpo=45221

   (13) https://bugs.python.org/issue?@action=redirect&bpo=45440

   (14) https://bugs.python.org/issue?@action=redirect&bpo=45405

   (15) https://bugs.python.org/issue?@action=redirect&bpo=45433


File: python.info,  Node: Windows<35>,  Next: macOS<25>,  Prev: Build<41>,  Up: Python 3 11 0 alpha 2

1.24.40.6 Windows
.................

   - bpo-43652(1): Update Tcl/Tk to 8.6.11, actually this time.  The
     previous update incorrectly included 8.6.10.

   - bpo-45337(2): venv now warns when the created environment may need
     to be accessed at a different path, due to redirections, links or
     junctions.  It also now correctly installs or upgrades components
     when the alternate path is required.

   - bpo-43851(3): Build SQLite ‘SQLITE_OMIT_AUTOINIT’ on Windows.
     Patch by Erlend E. Aasland.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43652

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45337

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43851


File: python.info,  Node: macOS<25>,  Next: IDLE<18>,  Prev: Windows<35>,  Up: Python 3 11 0 alpha 2

1.24.40.7 macOS
...............

   - bpo-44828(1): Avoid tkinter file dialog failure on macOS 12
     Monterey when using the Tk 8.6.11 provided by python.org macOS
     installers.  Patch by Marc Culler of the Tk project.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44828


File: python.info,  Node: IDLE<18>,  Next: C API<36>,  Prev: macOS<25>,  Up: Python 3 11 0 alpha 2

1.24.40.8 IDLE
..............

   - bpo-45495(1): Add context keywords “case” and “match” to
     completions list.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45495


File: python.info,  Node: C API<36>,  Prev: IDLE<18>,  Up: Python 3 11 0 alpha 2

1.24.40.9 C API
...............

   - bpo-29103(1): *note PyType_FromSpec*: 774. now copies the class
     name from the spec to a buffer owned by the class, so the original
     can be safely deallocated.  Patch by Petr Viktorin.

   - bpo-45522(2): The internal freelists for frame, float, list, dict,
     async generators, and context objects can now be disabled.

   - bpo-35134(3): Exclude *note PyWeakref_GET_OBJECT(): 3de. from the
     limited C API. It never worked since the ‘PyWeakReference’
     structure is opaque in the limited C API.

   - bpo-35081(4): Move the ‘interpreteridobject.h’ header file from
     ‘Include/’ to ‘Include/internal/’.  It only provides private
     functions.  Patch by Victor Stinner.

   - bpo-35134(5): The non-limited API files ‘cellobject.h’,
     ‘classobject.h’, ‘context.h’, ‘funcobject.h’, ‘genobject.h’ and
     ‘longintrepr.h’ have been moved to the ‘Include/cpython’ directory.
     Moreover, the ‘eval.h’ header file was removed.  These files must
     not be included directly, as they are already included in
     ‘Python.h’: *note Include Files: 988.  If they have been included
     directly, consider including ‘Python.h’ instead.  Patch by Victor
     Stinner.

   - bpo-45474(6): The following items are no longer available when
     ‘Py_LIMITED_API’ is defined:

        * *note PyMarshal_WriteLongToFile(): 99a.

        * *note PyMarshal_WriteObjectToFile(): 99b.

        * *note PyMarshal_ReadObjectFromString(): 99c.

        * *note PyMarshal_WriteObjectToString(): 99d.

        * the ‘Py_MARSHAL_VERSION’ macro

     These are not part of the *note limited API: 99e.

     Patch by Victor Stinner.

   - bpo-45434(7): Remove the ‘pystrhex.h’ header file.  It only
     contains private functions.  C extensions should only include the
     main ‘<Python.h>’ header file.  Patch by Victor Stinner.

   - bpo-45440(8): Remove the ‘Py_FORCE_DOUBLE()’ macro.  It was used by
     the ‘Py_IS_INFINITY()’ macro.  Patch by Victor Stinner.

   - bpo-45434(9): ‘<Python.h>’ no longer includes the header files
     ‘<stdlib.h>’, ‘<stdio.h>’, ‘<errno.h>’ and ‘<string.h>’ when the
     ‘Py_LIMITED_API’ macro is set to ‘0x030b0000’ (Python 3.11) or
     higher.  C extensions should explicitly include the header files
     after ‘#include <Python.h>’.  Patch by Victor Stinner.

   - bpo-41123(10): Remove ‘Py_UNICODE_COPY()’ and ‘Py_UNICODE_FILL()’
     macros, deprecated since Python 3.3.  Use
     ‘PyUnicode_CopyCharacters()’ or ‘memcpy()’ (‘wchar_t*’ string), and
     ‘PyUnicode_Fill()’ functions instead.  Patch by Victor Stinner.

   - bpo-45412(11): Remove the following math macros using the ‘errno’
     variable:

        * ‘Py_ADJUST_ERANGE1()’

        * ‘Py_ADJUST_ERANGE2()’

        * ‘Py_OVERFLOWED()’

        * ‘Py_SET_ERANGE_IF_OVERFLOW()’

        * ‘Py_SET_ERRNO_ON_MATH_ERROR()’

     Patch by Victor Stinner.

   - bpo-45395(12): Custom frozen modules (the array set to
     ‘PyImport_FrozenModules’) are now treated as additions, rather than
     replacing all the default frozen modules.  Frozen stdlib modules
     can still be disabled by setting the «code» field of the custom
     array entry to NULL.

   - bpo-43760(13): Add new *note PyThreadState_EnterTracing(): 95b, and
     *note PyThreadState_LeaveTracing(): 95c. functions to the limited C
     API to suspend and resume tracing and profiling.  Patch by Victor
     Stinner.

   - bpo-44220(14): *note PyStructSequence_UnnamedField: b7b. is added
     to the Stable ABI.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29103

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45522

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35134

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35081

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35134

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45474

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45434

   (8) https://bugs.python.org/issue?@action=redirect&bpo=45440

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45434

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41123

   (11) https://bugs.python.org/issue?@action=redirect&bpo=45412

   (12) https://bugs.python.org/issue?@action=redirect&bpo=45395

   (13) https://bugs.python.org/issue?@action=redirect&bpo=43760

   (14) https://bugs.python.org/issue?@action=redirect&bpo=44220


File: python.info,  Node: Python 3 11 0 alpha 1,  Next: Python 3 10 0 beta 1,  Prev: Python 3 11 0 alpha 2,  Up: Changelog

1.24.41 Python 3.11.0 alpha 1
-----------------------------

'Release date: 2021-10-05'

* Menu:

* Security: Security<29>.
* Core and Builtins: Core and Builtins<103>.
* Library: Library<106>.
* Core and Builtins: Core and Builtins<104>.
* Library: Library<107>.
* Core and Builtins: Core and Builtins<105>.
* Library: Library<108>.
* Core and Builtins: Core and Builtins<106>.
* Library: Library<109>.
* Core and Builtins: Core and Builtins<107>.
* Library: Library<110>.
* Core and Builtins: Core and Builtins<108>.
* Library: Library<111>.
* Core and Builtins: Core and Builtins<109>.
* Library: Library<112>.
* Core and Builtins: Core and Builtins<110>.
* Library: Library<113>.
* Core and Builtins: Core and Builtins<111>.
* Library: Library<114>.
* Core and Builtins: Core and Builtins<112>.
* Library: Library<115>.
* Documentation: Documentation<35>.
* Tests: Tests<35>.
* Build: Build<42>.
* Windows: Windows<36>.
* macOS: macOS<26>.
* IDLE: IDLE<19>.
* Tools/Demos: Tools/Demos<27>.
* C API: C API<37>.


File: python.info,  Node: Security<29>,  Next: Core and Builtins<103>,  Up: Python 3 11 0 alpha 1

1.24.41.1 Security
..................

   - bpo-42278(1): Replaced usage of *note tempfile.mktemp(): 1c18. with
     *note TemporaryDirectory: 143c. to avoid a potential race
     condition.

   - bpo-44600(2): Fix incorrect line numbers while tracing some failed
     patterns in *note match: a10. statements.  Patch by Charles
     Burkland.

   - bpo-41180(3): Add auditing events to the *note marshal: 91. module,
     and stop raising ‘code.__init__’ events for every unmarshalled code
     object.  Directly instantiated code objects will continue to raise
     an event, and audit event handlers should inspect or collect the
     raw marshal data.  This reduces a significant performance overhead
     when loading from ‘.pyc’ files.

   - bpo-44394(4): Update the vendored copy of libexpat to 2.4.1 (from
     2.2.8) to get the fix for the CVE 2013-0340(5) «Billion Laughs»
     vulnerability.  This copy is most used on Windows and macOS.

   - bpo-43124(6): Made the internal ‘putcmd’ function in *note smtplib:
     cf. sanitize input for presence of ‘\r’ and ‘\n’ characters to
     avoid (unlikely) command injection.

   - bpo-44022(7): *note http.client: 73. now avoids infinitely reading
     potential HTTP headers after a ‘100 Continue’ status response from
     the server.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42278

   (2) https://bugs.python.org/issue?@action=redirect&bpo=44600

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41180

   (4) https://bugs.python.org/issue?@action=redirect&bpo=44394

   (5) https://www.cve.org/CVERecord?id=CVE-2013-0340

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43124

   (7) https://bugs.python.org/issue?@action=redirect&bpo=44022


File: python.info,  Node: Core and Builtins<103>,  Next: Library<106>,  Prev: Security<29>,  Up: Python 3 11 0 alpha 1

1.24.41.2 Core and Builtins
...........................

   - bpo-43760(1): The number of hardware branches per instruction
     dispatch is reduced from two to one by adding a special instruction
     for tracing.  Patch by Mark Shannon.

   - bpo-45061(2): Add a deallocator to the bool type to detect refcount
     bugs in C extensions which call Py_DECREF(Py_True) or
     Py_DECREF(Py_False) by mistake.  Detect also refcount bugs when the
     empty tuple singleton or the Unicode empty string singleton is
     destroyed by mistake.  Patch by Victor Stinner.

   - bpo-24076(3): sum() was further optimised for summing up single
     digit integers.

   - bpo-45190(4): Update Unicode databases to Unicode 14.0.0.

   - bpo-45167(5): Fix deepcopying of *note types.GenericAlias: 9ee.
     objects.

   - bpo-45155(6): *note int.to_bytes(): 1c1a. and *note
     int.from_bytes(): 1bd1. now take a default value of ‘"big"’ for the
     ‘byteorder’ argument.  *note int.to_bytes(): 1c1a. also takes a
     default value of ‘1’ for the ‘length’ argument.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43760

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45061

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24076

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45190

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45167

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45155


File: python.info,  Node: Library<106>,  Next: Core and Builtins<104>,  Prev: Core and Builtins<103>,  Up: Python 3 11 0 alpha 1

1.24.41.3 Library
.................

   - bpo-44219(1): Release the GIL while performing ‘isatty’ system
     calls on arbitrary file descriptors.  In particular, this affects
     *note os.isatty(): 1c1c, *note os.device_encoding(): 1c1d. and
     *note io.TextIOWrapper: 9c0.  By extension, *note io.open(): 741.
     in text mode is also affected.  This change solves a deadlock in
     *note os.isatty(): 1c1c.  Patch by Vincent Michel in bpo-44219(2).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44219

   (2) https://bugs.python.org/issue?@action=redirect&bpo=44219


File: python.info,  Node: Core and Builtins<104>,  Next: Library<107>,  Prev: Library<106>,  Up: Python 3 11 0 alpha 1

1.24.41.4 Core and Builtins
...........................

   - bpo-44959(1): Added fallback to extension modules with “.sl” suffix
     on HP-UX

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44959


File: python.info,  Node: Library<107>,  Next: Core and Builtins<105>,  Prev: Core and Builtins<104>,  Up: Python 3 11 0 alpha 1

1.24.41.5 Library
.................

   - bpo-45121(1): Fix issue where ‘Protocol.__init__’ raises
     ‘RecursionError’ when it’s called directly or via ‘super()’.  Patch
     provided by Yurii Karabas.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45121


File: python.info,  Node: Core and Builtins<105>,  Next: Library<108>,  Prev: Library<107>,  Up: Python 3 11 0 alpha 1

1.24.41.6 Core and Builtins
...........................

   - bpo-44348(1): The deallocator function of the *note BaseException:
     7d8. type now uses the trashcan mechanism to prevent stack
     overflow.  For example, when a *note RecursionError: f6a. instance
     is raised, it can be linked to another RecursionError through the
     ‘__context__’ attribute or the ‘__traceback__’ attribute, and then
     a chain of exceptions is created.  When the chain is destroyed,
     nested deallocator function calls can crash with a stack overflow
     if the chain is too long compared to the available stack memory.
     Patch by Victor Stinner.

   - bpo-45123(2): Fix PyAiter_Check to only check for the __anext__
     presence (not for __aiter__).  Rename PyAiter_Check to
     PyAIter_Check, PyObject_GetAiter -> PyObject_GetAIter.

   - bpo-1514420(3): Interpreter no longer attempts to open files with
     names in angle brackets (like «<string>» or «<stdin>») when
     formatting an exception.

   - bpo-41031(4): Match C and Python code formatting of unprintable
     exceptions and exceptions in the *note __main__: 1. module.

   - bpo-37330(5): *note open(): 316, *note io.open(): 741, *note
     codecs.open(): 315. and *note fileinput.FileInput: 941. no longer
     accept ‘'U'’ («universal newline») in the file mode.  This flag was
     deprecated since Python 3.3.  Patch by Victor Stinner.

   - bpo-45083(6): When the interpreter renders an exception, its name
     now has a complete qualname.  Previously only the class name was
     concatenated to the module name, which sometimes resulted in an
     incorrect full name being displayed.

     (This issue impacted only the C code exception rendering, the *note
     traceback: 104. module was using qualname already).

   - bpo-34561(7): List sorting now uses the merge-ordering strategy
     from Munro and Wild’s ‘powersort()’.  Unlike the former strategy,
     this is provably near-optimal in the entropy of the distribution of
     run lengths.  Most uses of ‘list.sort()’ probably won’t see a
     significant time difference, but may see significant improvements
     in cases where the former strategy was exceptionally poor.
     However, as these are all fast linear-time approximations to a
     problem that’s inherently at best quadratic-time to solve truly
     optimally, it’s also possible to contrive cases where the former
     strategy did better.

   - bpo-45056(8): Compiler now removes trailing unused constants from
     co_consts.

   - bpo-45020(9): Add a new command line option, «-X
     frozen_modules=[on|off]» to opt out of (or into) using optional
     frozen modules.  This defaults to «on» (or «off» if it’s running
     out of the source tree).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44348

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45123

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1514420

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41031

   (5) https://bugs.python.org/issue?@action=redirect&bpo=37330

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45083

   (7) https://bugs.python.org/issue?@action=redirect&bpo=34561

   (8) https://bugs.python.org/issue?@action=redirect&bpo=45056

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45020


File: python.info,  Node: Library<108>,  Next: Core and Builtins<106>,  Prev: Core and Builtins<105>,  Up: Python 3 11 0 alpha 1

1.24.41.7 Library
.................

   - bpo-45012(1): In *note posix: b2, release GIL during ‘stat()’,
     ‘lstat()’, and ‘fstatat()’ syscalls made by *note
     os.DirEntry.stat(): 1a53.  Patch by Stanisław Skonieczny.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45012


File: python.info,  Node: Core and Builtins<106>,  Next: Library<109>,  Prev: Library<108>,  Up: Python 3 11 0 alpha 1

1.24.41.8 Core and Builtins
...........................

   - bpo-45018(1): Fixed pickling of range iterators that iterated for
     over ‘2**32’ times.

   - bpo-45000(2): A *note SyntaxError: 18e. is now raised when trying
     to delete *note __debug__: 9dc.  Patch by Donghee Na.

   - bpo-44963(3): Implement ‘send()’ and ‘throw()’ methods for
     ‘anext_awaitable’ objects.  Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45018

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45000

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44963


File: python.info,  Node: Library<109>,  Next: Core and Builtins<107>,  Prev: Core and Builtins<106>,  Up: Python 3 11 0 alpha 1

1.24.41.9 Library
.................

   - bpo-44962(1): Fix a race in WeakKeyDictionary, WeakValueDictionary
     and WeakSet when two threads attempt to commit the last pending
     removal.  This fixes asyncio.create_task and fixes a data loss in
     asyncio.run where shutdown_asyncgens is not run

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44962


File: python.info,  Node: Core and Builtins<107>,  Next: Library<110>,  Prev: Library<109>,  Up: Python 3 11 0 alpha 1

1.24.41.10 Core and Builtins
............................

   - bpo-24234(1): Implement the ‘__bytes__()’ special method on the
     *note bytes: 192. type, so a bytes object ‘b’ passes an
     ‘isinstance(b, typing.SupportsBytes)’ check.

   - bpo-24234(2): Implement the ‘__complex__()’ special method on the
     *note complex: 197. type, so a complex number ‘z’ passes an
     ‘isinstance(z, typing.SupportsComplex)’ check.

   - bpo-44954(3): Fixed a corner case bug where the result of
     ‘float.fromhex('0x.8p-1074')’ was rounded the wrong way.

   - bpo-44947(4): Refine the syntax error for trailing commas in import
     statements.  Patch by Pablo Galindo.

   - bpo-44945(5): Specialize the BINARY_ADD instruction using the PEP
     659 machinery.  Adds five new instructions:

        * BINARY_ADD_ADAPTIVE

        * BINARY_ADD_FLOAT

        * BINARY_ADD_INT

        * BINARY_ADD_UNICODE

        * BINARY_ADD_UNICODE_INPLACE_FAST

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24234

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24234

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44954

   (4) https://bugs.python.org/issue?@action=redirect&bpo=44947

   (5) https://bugs.python.org/issue?@action=redirect&bpo=44945


File: python.info,  Node: Library<110>,  Next: Core and Builtins<108>,  Prev: Core and Builtins<107>,  Up: Python 3 11 0 alpha 1

1.24.41.11 Library
..................

   - bpo-44929(1): Fix some edge cases of ‘enum.Flag’ string
     representation in the REPL. Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44929


File: python.info,  Node: Core and Builtins<108>,  Next: Library<111>,  Prev: Library<110>,  Up: Python 3 11 0 alpha 1

1.24.41.12 Core and Builtins
............................

   - bpo-44914(1): Class version tags are no longer recycled.

     This means that a version tag serves as a unique identifier for the
     state of a class.  We rely on this for effective specialization of
     the LOAD_ATTR and other instructions.

   - bpo-44698(2): Restore behaviour of complex exponentiation with
     integer-valued exponent of type *note float: 196. or *note complex:
     197.

   - bpo-44895(3): A debug variable *note PYTHONDUMPREFSFILE: 1c27. is
     added for creating a dump file which is generated by *note
     -with-trace-refs: 636.  Patch by Donghee Na.

   - bpo-44900(4): Add five superinstructions for PEP 659 quickening:

        * LOAD_FAST LOAD_FAST

        * STORE_FAST LOAD_FAST

        * LOAD_FAST LOAD_CONST

        * LOAD_CONST LOAD_FAST

        * STORE_FAST STORE_FAST

   - bpo-44889(5): Initial implementation of adaptive specialization of
     ‘LOAD_METHOD’.  The following specialized forms were added:

        * ‘LOAD_METHOD_CACHED’

        * ‘LOAD_METHOD_MODULE’

        * ‘LOAD_METHOD_CLASS’

   - bpo-44890(6): Specialization stats are always collected in debug
     builds.

   - bpo-44885(7): Correct the ast locations of f-strings with format
     specs and repeated expressions.  Patch by Pablo Galindo

   - bpo-44878(8): Remove the loop from the bytecode interpreter.  All
     instructions end with a DISPATCH macro, so the loop is now
     redundant.

   - bpo-44878(9): Remove switch statement for interpreter loop when
     using computed gotos.  This makes sure that we only have one
     dispatch table in the interpreter.

   - bpo-44874(10): Deprecate the old trashcan macros
     (‘Py_TRASHCAN_SAFE_BEGIN’/‘Py_TRASHCAN_SAFE_END’).  They should be
     replaced by the new macros ‘Py_TRASHCAN_BEGIN’ and
     ‘Py_TRASHCAN_END’.

   - bpo-44872(11): Use new trashcan macros (Py_TRASHCAN_BEGIN/END) in
     frameobject.c instead of the old ones (Py_TRASHCAN_SAFE_BEGIN/END).

   - bpo-33930(12): Fix segmentation fault with deep recursion when
     cleaning method objects.  Patch by Augusto Goulart and Pablo
     Galindo.

   - bpo-25782(13): Fix bug where ‘PyErr_SetObject’ hangs when the
     current exception has a cycle in its context chain.

   - bpo-44856(14): Fix reference leaks in the error paths of
     ‘update_bases()’ and ‘__build_class__’.  Patch by Pablo Galindo.

   - bpo-44826(15): Initial implementation of adaptive specialization of
     STORE_ATTR

     Three specialized forms of STORE_ATTR are added:

        * STORE_ATTR_SLOT

        * STORE_ATTR_SPLIT_KEYS

        * STORE_ATTR_WITH_HINT

   - bpo-44838(16): Fixed a bug that was causing the parser to raise an
     incorrect custom *note SyntaxError: 18e. for invalid “if”
     expressions.  Patch by Pablo Galindo.

   - bpo-44821(17): Create instance dictionaries (__dict__) eagerly, to
     improve regularity of object layout and assist specialization.

   - bpo-44792(18): Improve syntax errors for if expressions.  Patch by
     Miguel Brito

   - bpo-34013(19): Generalize the invalid legacy statement custom error
     message (like the one generated when «print» is called without
     parentheses) to include more generic expressions.  Patch by Pablo
     Galindo

   - bpo-44732(20): Rename ‘types.Union’ to ‘types.UnionType’.

   - bpo-44725(21): Expose specialization stats in python via
     ‘_opcode.get_specialization_stats()’.

   - bpo-44717(22): Improve AttributeError on circular imports of
     submodules.

   - bpo-44698(23): Fix undefined behaviour in complex object
     exponentiation.

   - bpo-44653(24): Support *note typing: 10a. types in parameter
     substitution in the union type.

   - bpo-44676(25): Add ability to serialise ‘types.Union’ objects.
     Patch provided by Yurii Karabas.

   - bpo-44633(26): Parameter substitution of the union type with wrong
     types now raises ‘TypeError’ instead of returning *note
     NotImplemented: 1a2.

   - bpo-44661(27): Update ‘property_descr_set’ to use vectorcall if
     possible.  Patch by Donghee Na.

   - bpo-44662(28): Add ‘__module__’ to ‘types.Union’.  This also fixes
     ‘types.Union’ issues with ‘typing.Annotated’.  Patch provided by
     Yurii Karabas.

   - bpo-44655(29): Include the name of the type in unset __slots__
     attribute errors.  Patch by Pablo Galindo

   - bpo-44655(30): Don’t include a missing attribute with the same name
     as the failing one when offering suggestions for missing
     attributes.  Patch by Pablo Galindo

   - bpo-44646(31): Fix the hash of the union type: it no longer depends
     on the order of arguments.

   - bpo-44636(32): Collapse union of equal types.  E.g.  the result of
     ‘int | int’ is now ‘int’.  Fix comparison of the union type with
     non-hashable objects.  E.g.  ‘int | str == {}’ no longer raises a
     TypeError.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44914

   (2) https://bugs.python.org/issue?@action=redirect&bpo=44698

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44895

   (4) https://bugs.python.org/issue?@action=redirect&bpo=44900

   (5) https://bugs.python.org/issue?@action=redirect&bpo=44889

   (6) https://bugs.python.org/issue?@action=redirect&bpo=44890

   (7) https://bugs.python.org/issue?@action=redirect&bpo=44885

   (8) https://bugs.python.org/issue?@action=redirect&bpo=44878

   (9) https://bugs.python.org/issue?@action=redirect&bpo=44878

   (10) https://bugs.python.org/issue?@action=redirect&bpo=44874

   (11) https://bugs.python.org/issue?@action=redirect&bpo=44872

   (12) https://bugs.python.org/issue?@action=redirect&bpo=33930

   (13) https://bugs.python.org/issue?@action=redirect&bpo=25782

   (14) https://bugs.python.org/issue?@action=redirect&bpo=44856

   (15) https://bugs.python.org/issue?@action=redirect&bpo=44826

   (16) https://bugs.python.org/issue?@action=redirect&bpo=44838

   (17) https://bugs.python.org/issue?@action=redirect&bpo=44821

   (18) https://bugs.python.org/issue?@action=redirect&bpo=44792

   (19) https://bugs.python.org/issue?@action=redirect&bpo=34013

   (20) https://bugs.python.org/issue?@action=redirect&bpo=44732

   (21) https://bugs.python.org/issue?@action=redirect&bpo=44725

   (22) https://bugs.python.org/issue?@action=redirect&bpo=44717

   (23) https://bugs.python.org/issue?@action=redirect&bpo=44698

   (24) https://bugs.python.org/issue?@action=redirect&bpo=44653

   (25) https://bugs.python.org/issue?@action=redirect&bpo=44676

   (26) https://bugs.python.org/issue?@action=redirect&bpo=44633

   (27) https://bugs.python.org/issue?@action=redirect&bpo=44661

   (28) https://bugs.python.org/issue?@action=redirect&bpo=44662

   (29) https://bugs.python.org/issue?@action=redirect&bpo=44655

   (30) https://bugs.python.org/issue?@action=redirect&bpo=44655

   (31) https://bugs.python.org/issue?@action=redirect&bpo=44646

   (32) https://bugs.python.org/issue?@action=redirect&bpo=44636


File: python.info,  Node: Library<111>,  Next: Core and Builtins<109>,  Prev: Core and Builtins<108>,  Up: Python 3 11 0 alpha 1

1.24.41.13 Library
..................

   - bpo-44611(1): On Windows, *note os.urandom(): 747.: uses
     BCryptGenRandom API instead of CryptGenRandom API which is
     deprecated from Microsoft Windows API. Patch by Donghee Na.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44611


File: python.info,  Node: Core and Builtins<109>,  Next: Library<112>,  Prev: Library<111>,  Up: Python 3 11 0 alpha 1

1.24.41.14 Core and Builtins
............................

   - bpo-44635(1): Convert ‘None’ to ‘type(None)’ in the union type
     constructor.

   - bpo-26280(2): Implement adaptive specialization for BINARY_SUBSCR

     Three specialized forms of BINARY_SUBSCR are added:

        * BINARY_SUBSCR_LIST_INT

        * BINARY_SUBSCR_TUPLE_INT

        * BINARY_SUBSCR_DICT

   - bpo-44589(3): Mapping patterns in ‘match’ statements with two or
     more equal literal keys will now raise a *note SyntaxError: 18e. at
     compile-time.

   - bpo-44606(4): Fix ‘__instancecheck__’ and ‘__subclasscheck__’ for
     the union type.

   - bpo-42073(5): The ‘@classmethod’ decorator can now wrap other
     classmethod-like descriptors.

   - bpo-41972(6): Tuned the string-searching algorithm of fastsearch.h
     to have a shorter inner loop for most cases.

   - bpo-44590(7): All necessary data for executing a Python function
     (local variables, stack, etc) is now kept in a per-thread stack.
     Frame objects are lazily allocated on demand.  This increases
     performance by about 7% on the standard benchmark suite.
     Introspection and debugging are unaffected as frame objects are
     always available when needed.  Patch by Mark Shannon.

   - bpo-44584(8): The threading debug (‘PYTHONTHREADDEBUG’ environment
     variable) is deprecated in Python 3.10 and will be removed in
     Python 3.12.  This feature requires a debug build of Python.  Patch
     by Victor Stinner.

   - bpo-43895(9): An obsolete internal cache of shared object file
     handles added in 1995 that attempted, but did not guarantee, that a
     .so would not be dlopen’ed twice to work around flaws in mid-1990s
     posix-ish operating systems has been removed from dynload_shlib.c.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44635

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26280

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44589

   (4) https://bugs.python.org/issue?@action=redirect&bpo=44606

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42073

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41972

   (7) https://bugs.python.org/issue?@action=redirect&bpo=44590

   (8) https://bugs.python.org/issue?@action=redirect&bpo=44584

   (9) https://bugs.python.org/issue?@action=redirect&bpo=43895


File: python.info,  Node: Library<112>,  Next: Core and Builtins<110>,  Prev: Core and Builtins<109>,  Up: Python 3 11 0 alpha 1

1.24.41.15 Library
..................

   - bpo-44490(1): *note typing: 10a. now searches for type parameters
     in ‘types.Union’ objects.  ‘get_type_hints’ will also properly
     resolve annotations with nested ‘types.Union’ objects.  Patch
     provided by Yurii Karabas.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44490


File: python.info,  Node: Core and Builtins<110>,  Next: Library<113>,  Prev: Library<112>,  Up: Python 3 11 0 alpha 1

1.24.41.16 Core and Builtins
............................

   - bpo-43950(1): Code objects can now provide the column information
     for instructions when available.  This is levaraged during
     traceback printing to show the expressions responsible for errors.

     Contributed by Pablo Galindo, Batuhan Taskaya and Ammar Askar as
     part of PEP 657(2).

   - bpo-44562(3): Remove uses of *note PyObject_GC_Del(): 170a. in
     error path when initializing *note types.GenericAlias: 9ee.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43950

   (2) https://peps.python.org/pep-0657/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44562


File: python.info,  Node: Library<113>,  Next: Core and Builtins<111>,  Prev: Core and Builtins<110>,  Up: Python 3 11 0 alpha 1

1.24.41.17 Library
..................

   - bpo-41486(1): Fix a memory consumption and copying performance
     regression in earlier 3.10 beta releases if someone used an output
     buffer larger than 4GiB with zlib.decompress on input data that
     expands that large.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41486


File: python.info,  Node: Core and Builtins<111>,  Next: Library<114>,  Prev: Library<113>,  Up: Python 3 11 0 alpha 1

1.24.41.18 Core and Builtins
............................

   - bpo-43908(1): Heap types with the *note Py_TPFLAGS_IMMUTABLETYPE:
     3cf. flag can now inherit the PEP 590(2) vectorcall protocol.
     Previously, this was only possible for *note static types: 984.
     Patch by Erlend E. Aasland.

   - bpo-44553(3): Implement GC methods for ‘types.Union’ to break
     reference cycles and prevent memory leaks.

   - bpo-44490(4): Add ‘__parameters__’ attribute and ‘__getitem__’
     operator to ‘types.Union’.  Patch provided by Yurii Karabas.

   - bpo-44523(5): Remove the pass-through for *note hash(): 802. of
     *note weakref.proxy: c48. objects to prevent unintended
     consequences when the original referred object dies while the proxy
     is part of a hashable object.  Patch by Pablo Galindo.

   - bpo-44483(6): Fix a crash in ‘types.Union’ objects when creating a
     union of an object with bad ‘__module__’ field.

   - bpo-44486(7): Modules will always have a dictionary, even when
     created by ‘types.ModuleType.__new__()’

   - bpo-44472(8): Fix ltrace functionality when exceptions are raised.
     Patch by Pablo Galindo

   - bpo-12022(9): A *note TypeError: 198. is now raised instead of an
     *note AttributeError: 5f0. in *note with: 186. and *note async
     with: 185. statements for objects which do not support the *note
     context manager: 1e1. or *note asynchronous context manager: 7f1.
     protocols correspondingly.

   - bpo-44297(10): Make sure that the line number is set when entering
     a comprehension scope.  This ensures that backtraces including
     generator expressions show the correct line number.

   - bpo-44456(11): Improve the syntax error when mixing positional and
     keyword patterns.  Patch by Pablo Galindo.

   - bpo-44409(12): Fix error location information for tokenizer errors
     raised on initialization of the tokenizer.  Patch by Pablo Galindo.

   - bpo-44396(13): Fix a possible crash in the tokenizer when raising
     syntax errors for unclosed strings.  Patch by Pablo Galindo.

   - bpo-44376(14): Exact integer exponentiation (like ‘i**2’ or ‘pow(i,
     2)’) with a small exponent is much faster, due to reducing overhead
     in such cases.

   - bpo-44313(15): Directly imported objects and modules (through
     import and from import statements) don’t generate
     ‘LOAD_METHOD’/‘CALL_METHOD’ for directly accessed objects on their
     namespace.  They now use the regular ‘LOAD_ATTR’/‘CALL_FUNCTION’.

   - bpo-44338(16): Implement adaptive specialization for LOAD_GLOBAL

     Two specialized forms of LOAD_GLOBAL are added:

        * LOAD_GLOBAL_MODULE

        * LOAD_GLOBAL_BUILTIN

   - bpo-44368(17): Improve syntax errors for invalid «as» targets.
     Patch by Pablo Galindo

   - bpo-44349(18): Fix an edge case when displaying text from files
     with encoding in syntax errors.  Patch by Pablo Galindo.

   - bpo-44337(19): Initial implementation of adaptive specialization of
     LOAD_ATTR

     Four specialized forms of LOAD_ATTR are added:

        * LOAD_ATTR_SLOT

        * LOAD_ATTR_SPLIT_KEYS

        * LOAD_ATTR_WITH_HINT

        * LOAD_ATTR_MODULE

   - bpo-44335(20): Fix a regression when identifying incorrect
     characters in syntax errors.  Patch by Pablo Galindo

   - bpo-43693(21): Computation of the offsets of cell variables is done
     in the compiler instead of at runtime.  This reduces the overhead
     of handling cell and free variables, especially in the case where a
     variable is both an argument and cell variable.

   - bpo-44317(22): Improve tokenizer error with improved locations.
     Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43908

   (2) https://peps.python.org/pep-0590/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44553

   (4) https://bugs.python.org/issue?@action=redirect&bpo=44490

   (5) https://bugs.python.org/issue?@action=redirect&bpo=44523

   (6) https://bugs.python.org/issue?@action=redirect&bpo=44483

   (7) https://bugs.python.org/issue?@action=redirect&bpo=44486

   (8) https://bugs.python.org/issue?@action=redirect&bpo=44472

   (9) https://bugs.python.org/issue?@action=redirect&bpo=12022

   (10) https://bugs.python.org/issue?@action=redirect&bpo=44297

   (11) https://bugs.python.org/issue?@action=redirect&bpo=44456

   (12) https://bugs.python.org/issue?@action=redirect&bpo=44409

   (13) https://bugs.python.org/issue?@action=redirect&bpo=44396

   (14) https://bugs.python.org/issue?@action=redirect&bpo=44376

   (15) https://bugs.python.org/issue?@action=redirect&bpo=44313

   (16) https://bugs.python.org/issue?@action=redirect&bpo=44338

   (17) https://bugs.python.org/issue?@action=redirect&bpo=44368

   (18) https://bugs.python.org/issue?@action=redirect&bpo=44349

   (19) https://bugs.python.org/issue?@action=redirect&bpo=44337

   (20) https://bugs.python.org/issue?@action=redirect&bpo=44335

   (21) https://bugs.python.org/issue?@action=redirect&bpo=43693

   (22) https://bugs.python.org/issue?@action=redirect&bpo=44317


File: python.info,  Node: Library<114>,  Next: Core and Builtins<112>,  Prev: Core and Builtins<111>,  Up: Python 3 11 0 alpha 1

1.24.41.19 Library
..................

   - bpo-44304(1): Fix a crash in the *note sqlite3: d4. module that
     happened when the garbage collector clears ‘sqlite.Statement’
     objects.  Patch by Pablo Galindo

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44304


File: python.info,  Node: Core and Builtins<112>,  Next: Library<115>,  Prev: Library<114>,  Up: Python 3 11 0 alpha 1

1.24.41.20 Core and Builtins
............................

   - bpo-44305(1): Improve error message for ‘try’ blocks without
     ‘except’ or ‘finally’ blocks.  Patch by Pablo Galindo.

   - bpo-43413(2): Constructors of subclasses of some builtin classes
     (e.g.  *note tuple: 614, *note list: 24d, *note frozenset: 7f3.) no
     longer accept arbitrary keyword arguments.  [reverted in 3.11a4]
     Subclass of *note set: 184. can now define a ‘__new__()’ method
     with additional keyword parameters without overriding also
     ‘__init__()’.

   - bpo-43667(3): Improve Unicode support in non-UTF locales on Oracle
     Solaris.  This issue does not affect other Solaris systems.

   - bpo-43693(4): A new opcode MAKE_CELL has been added that
     effectively moves some of the work done on function entry into the
     compiler and into the eval loop.  In addition to creating the
     required cell objects, the new opcode converts relevant arguments
     (and other locals) to cell variables on function entry.

   - bpo-44232(5): Fix a regression in *note type(): f46. when a
     metaclass raises an exception.  The C function ‘type_new()’ must
     properly report the exception when a metaclass constructor raises
     an exception and the winner class is not the metaclass.  Patch by
     Victor Stinner.

   - bpo-44201(6): Avoid side effects of checking for specialized syntax
     errors in the REPL that was causing it to ask for extra tokens
     after a syntax error had been detected.  Patch by Pablo Galindo

   - bpo-43693(7): ‘PyCodeObject’ gained ‘co_fastlocalnames’ and
     ‘co_fastlocalkinds’ as the authoritative source of fast locals
     info.  Marshaled code objects have changed accordingly.

   - bpo-44184(8): Fix a crash at Python exit when a deallocator
     function removes the last strong reference to a heap type.  Patch
     by Victor Stinner.

   - bpo-44187(9): Implement quickening in the interpreter.  This offers
     no advantages as yet, but is an enabler of future optimizations.
     See PEP 659 for full explanation.

   - bpo-44180(10): The parser doesn’t report generic syntax errors that
     happen in a position further away that the one it reached in the
     first pass.  Patch by Pablo Galindo

   - bpo-44168(11): Fix error message in the parser involving keyword
     arguments with invalid expressions.  Patch by Pablo Galindo

   - bpo-44156(12): String caches in ‘compile.c’ are now subinterpreter
     compatible.

   - bpo-44143(13): Fixed a crash in the parser that manifest when
     raising tokenizer errors when an existing exception was present.
     Patch by Pablo Galindo.

   - bpo-44032(14): Move “fast” locals and other variables from the
     frame object to a per-thread datastack.

   - bpo-44114(15): Fix incorrect dictkeys_reversed and
     dictitems_reversed function signatures in C code, which broke
     webassembly builds.

   - bpo-44110(16): Improve ‘str.__getitem__()’ error message

   - bpo-26110(17): Add ‘CALL_METHOD_KW’ opcode to speed up method calls
     with keyword arguments.  Idea originated from PyPy.  A side effect
     is executing ‘CALL_METHOD’ is now branchless in the evaluation
     loop.

   - bpo-28307(18): Compiler now optimizes simple C-style formatting
     with literal format containing only format codes %s, %r and %a by
     converting them to f-string expressions.

   - bpo-43149(19): Correct the syntax error message regarding multiple
     exception types to not refer to «exception groups».  Patch by Pablo
     Galindo

   - bpo-43822(20): The parser will prioritize tokenizer errors over
     custom syntax errors when raising exceptions.  Patch by Pablo
     Galindo.

   - bpo-40222(21): «Zero cost» exception handling.

        * Uses a lookup table to determine how to handle exceptions.

        * Removes SETUP_FINALLY and POP_TOP block instructions,
          eliminating the runtime overhead of try statements.

        * Reduces the size of the frame object by about 60%.

     Patch by Mark Shannon

   - bpo-43918(22): Document the signature and ‘default’ argument in the
     docstring of the new ‘anext’ builtin.

   - bpo-43833(23): Emit a deprecation warning if the numeric literal is
     immediately followed by one of keywords: and, else, for, if, in,
     is, or.  Raise a syntax error with more informative message if it
     is immediately followed by other keyword or identifier.

   - bpo-43879(24): Add native_thread_id to PyThreadState.  Patch by
     Gabriele N. Tornetta.

   - bpo-43693(25): Compute cell offsets relative to locals in compiler.
     Allows the interpreter to treats locals and cells a single array,
     which is slightly more efficient.  Also make the LOAD_CLOSURE
     opcode an alias for LOAD_FAST. Preserving LOAD_CLOSURE helps keep
     bytecode a bit more readable.

   - bpo-17792(26): More accurate error messages for access of unbound
     locals or free vars.

   - bpo-28146(27): Fix a confusing error message in *note str.format():
     834.

   - bpo-11105(28): When compiling *note ast.AST: 4c4. objects with
     recursive references through *note compile(): 4b2, the interpreter
     doesn’t crash anymore instead it raises a *note RecursionError:
     f6a.

   - bpo-39091(29): Fix crash when using passing a non-exception to a
     generator’s ‘throw()’ method.  Patch by Noah Oxer

   - bpo-33346(30): Asynchronous comprehensions are now allowed inside
     comprehensions in asynchronous functions.  Outer comprehensions
     implicitly become asynchronous.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44305

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43413

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43667

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43693

   (5) https://bugs.python.org/issue?@action=redirect&bpo=44232

   (6) https://bugs.python.org/issue?@action=redirect&bpo=44201

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43693

   (8) https://bugs.python.org/issue?@action=redirect&bpo=44184

   (9) https://bugs.python.org/issue?@action=redirect&bpo=44187

   (10) https://bugs.python.org/issue?@action=redirect&bpo=44180

   (11) https://bugs.python.org/issue?@action=redirect&bpo=44168

   (12) https://bugs.python.org/issue?@action=redirect&bpo=44156

   (13) https://bugs.python.org/issue?@action=redirect&bpo=44143

   (14) https://bugs.python.org/issue?@action=redirect&bpo=44032

   (15) https://bugs.python.org/issue?@action=redirect&bpo=44114

   (16) https://bugs.python.org/issue?@action=redirect&bpo=44110

   (17) https://bugs.python.org/issue?@action=redirect&bpo=26110

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28307

   (19) https://bugs.python.org/issue?@action=redirect&bpo=43149

   (20) https://bugs.python.org/issue?@action=redirect&bpo=43822

   (21) https://bugs.python.org/issue?@action=redirect&bpo=40222

   (22) https://bugs.python.org/issue?@action=redirect&bpo=43918

   (23) https://bugs.python.org/issue?@action=redirect&bpo=43833

   (24) https://bugs.python.org/issue?@action=redirect&bpo=43879

   (25) https://bugs.python.org/issue?@action=redirect&bpo=43693

   (26) https://bugs.python.org/issue?@action=redirect&bpo=17792

   (27) https://bugs.python.org/issue?@action=redirect&bpo=28146

   (28) https://bugs.python.org/issue?@action=redirect&bpo=11105

   (29) https://bugs.python.org/issue?@action=redirect&bpo=39091

   (30) https://bugs.python.org/issue?@action=redirect&bpo=33346


File: python.info,  Node: Library<115>,  Next: Documentation<35>,  Prev: Core and Builtins<112>,  Up: Python 3 11 0 alpha 1

1.24.41.21 Library
..................

   - bpo-45371(1): Fix clang rpath issue in ‘distutils’.  The
     UnixCCompiler now uses correct clang option to add a runtime
     library directory (rpath) to a shared library.

   - bpo-45329(2): Fix freed memory access in ‘pyexpat.xmlparser’ when
     building it with an installed expat library <= 2.2.0.

   - bpo-41710(3): On Unix, if the ‘sem_clockwait()’ function is
     available in the C library (glibc 2.30 and newer), the *note
     threading.Lock.acquire(): 8a8. method now uses the monotonic clock
     (*note time.CLOCK_MONOTONIC: 8a9.) for the timeout, rather than
     using the system clock (*note time.CLOCK_REALTIME: 8aa.), to not be
     affected by system clock changes.  Patch by Victor Stinner.

   - bpo-1596321(4): Fix the ‘threading._shutdown()’ function when the
     *note threading: f3. module was imported first from a thread
     different than the main thread: no longer log an error at Python
     exit.

   - bpo-45274(5): Fix a race condition in the *note Thread.join():
     13ec. method of the *note threading: f3. module.  If the function
     is interrupted by a signal and the signal handler raises an
     exception, make sure that the thread remains in a consistent state
     to prevent a deadlock.  Patch by Victor Stinner.

   - bpo-21302(6): In Unix operating systems, *note time.sleep(): 8ad.
     now uses the ‘nanosleep()’ function, if ‘clock_nanosleep()’ is not
     available but ‘nanosleep()’ is available.  ‘nanosleep()’ allows to
     sleep with nanosecond precision.

   - bpo-21302(7): On Windows, *note time.sleep(): 8ad. now uses a
     waitable timer which has a resolution of 100 nanoseconds (10^-7
     seconds).  Previously, it had a resolution of 1 millisecond (10^-3
     seconds).  Patch by Benjamin Szőke and Victor Stinner.

   - bpo-45238(8): Fix ‘unittest.IsolatedAsyncioTestCase.debug()’: it
     runs now asynchronous methods and callbacks.

   - bpo-36674(9): *note unittest.TestCase.debug(): 1c31. raises now a
     *note unittest.SkipTest: 11e6. if the class or the test method are
     decorated with the skipping decorator.

   - bpo-45235(10): Fix an issue where argparse would not preserve
     values in a provided namespace when using a subparser with
     defaults.

   - bpo-45183(11): Have zipimport.zipimporter.find_spec() not raise an
     exception when the underlying zip file has been deleted and the
     internal cache has been reset via invalidate_cache().

   - bpo-45234(12): Fixed a regression in *note copyfile(): c50, *note
     copy(): c51, *note copy2(): c52. raising *note FileNotFoundError:
     264. when source is a directory, which should raise *note
     IsADirectoryError: 125b.

   - bpo-45228(13): Fix stack buffer overflow in parsing J1939 network
     address.

   - bpo-45225(14): use map function instead of genexpr in capwords.

   - bpo-42135(15): Fix typo: ‘importlib.find_loader’ is really slated
     for removal in Python 3.12 not 3.10, like the others in PR 25169.

     Patch by Hugo van Kemenade.

   - bpo-20524(16): Improves error messages on ‘.format()’ operation for
     ‘str’, ‘float’, ‘int’, and ‘complex’.  New format now shows the
     problematic pattern and the object type.

   - bpo-45168(17): Change *note dis.dis(): 205. output to omit op arg
     values that cannot be resolved due to ‘co_consts’, ‘co_names’ etc
     not being provided.  Previously the oparg itself was repeated in
     the value field, which is not useful and can be confusing.

   - bpo-21302(18): In Unix operating systems, *note time.sleep(): 8ad.
     now uses the ‘clock_nanosleep()’ function, if available, which
     allows to sleep for an interval specified with nanosecond
     precision.

   - bpo-45173(19): Remove from the *note configparser: 26. module: the
     ‘SafeConfigParser’ class, the ‘filename’ property of the *note
     ParsingError: 72a. class, the ‘readfp()’ method of the *note
     ConfigParser: 4df. class, deprecated since Python 3.2.

     Patch by Hugo van Kemenade.

   - bpo-44987(20): Pure ASCII strings are now normalized in constant
     time by *note unicodedata.normalize(): 8e5.  Patch by Donghee Na.

   - bpo-35474(21): Calling *note mimetypes.guess_all_extensions():
     1c32. with ‘strict=False’ no longer affects the result of the
     following call with ‘strict=True’.  Also, mutating the returned
     list no longer affects the global state.

   - bpo-45166(22): *note typing.get_type_hints(): 8c1. now works with
     *note Final: 56e. wrapped in *note ForwardRef: 1bc2.

   - bpo-45162(23): Remove many old deprecated *note unittest: 10c.
     features:

        * «‘fail*’» and «‘assert*’» aliases of *note TestCase: 2b3.
          methods.

        * Broken from start *note TestCase: 2b3. method
          ‘assertDictContainsSubset()’.

        * Ignored ‘<unittest.TestLoader.loadTestsFromModule>
          TestLoader.loadTestsFromModule()’ parameter 'use_load_tests'.

        * Old alias ‘_TextTestResult’ of *note TextTestResult: 755.

   - bpo-38371(24): Remove the deprecated ‘split()’ method of
     ‘_tkinter.TkappType’.  Patch by Erlend E. Aasland.

   - bpo-20499(25): Improve the speed and accuracy of
     statistics.pvariance().

   - bpo-45132(26): Remove *note __getitem__(): 588. methods of *note
     xml.dom.pulldom.DOMEventStream: 93f, *note
     wsgiref.util.FileWrapper: 940. and *note fileinput.FileInput: 941,
     deprecated since Python 3.9.

     Patch by Hugo van Kemenade.

   - bpo-45129(27): Due to significant security concerns, the
     'reuse_address' parameter of *note
     asyncio.loop.create_datagram_endpoint(): 93d, disabled in Python
     3.9, is now entirely removed.  This is because of the behavior of
     the socket option ‘SO_REUSEADDR’ in UDP.

     Patch by Hugo van Kemenade.

   - bpo-45124(28): The ‘bdist_msi’ command, deprecated in Python 3.9,
     is now removed.

     Use ‘bdist_wheel’ (wheel packages) instead.

     Patch by Hugo van Kemenade.

   - bpo-30856(29): *note unittest.TestResult: 136f. methods *note
     addFailure(): 1c33, *note addError(): 1c34, *note addSkip(): 1c35.
     and *note addSubTest(): 1c36. are now called immediately after
     raising an exception in test or finishing a subtest.  Previously
     they were called only after finishing the test clean up.

   - bpo-45034(30): Changes how error is formatted for ‘struct.pack’
     with ‘'H'’ and ‘'h'’ modes and too large / small numbers.  Now it
     shows the actual numeric limits, while previously it was showing
     arithmetic expressions.

   - bpo-25894(31): *note unittest: 10c. now always reports skipped and
     failed subtests separately: separate characters in default mode and
     separate lines in verbose mode.  Also the test description is now
     output for errors in test method, class and module cleanups.

   - bpo-45081(32): Fix issue when dataclasses that inherit from
     ‘typing.Protocol’ subclasses have wrong ‘__init__’.  Patch provided
     by Yurii Karabas.

   - bpo-45085(33): The ‘binhex’ module, deprecated in Python 3.9, is
     now removed.  The following *note binascii: 11. functions,
     deprecated in Python 3.9, are now also removed:

        * ‘a2b_hqx()’, ‘b2a_hqx()’;

        * ‘rlecode_hqx()’, ‘rledecode_hqx()’.

     The *note binascii.crc_hqx(): 93e. function remains available.

     Patch by Victor Stinner.

   - bpo-40360(34): The ‘lib2to3’ package is now deprecated and may not
     be able to parse Python 3.10 or newer.  See the PEP 617(35) (New
     PEG parser for CPython).  Patch by Victor Stinner.

   - bpo-45075(36): Rename ‘traceback.StackSummary.format_frame()’ to
     *note traceback.StackSummary.format_frame_summary(): 8b3.  This
     method was added for 3.11 so it was not released yet.

     Updated code and docs to better distinguish frame and FrameSummary.

   - bpo-31299(37): Add option to completely drop frames from a
     traceback by returning ‘None’ from a ‘format_frame()’ override.

   - bpo-41620(38): *note run(): 136e. now always return a *note
     TestResult: 136f. instance.  Previously it returned ‘None’ if the
     test class or method was decorated with a skipping decorator.

   - bpo-45021(39): Fix a potential deadlock at shutdown of forked
     children when using *note concurrent.futures: 24. module

   - bpo-43913(40): Fix bugs in cleaning up classes and modules in *note
     unittest: 10c.:

        * Functions registered with *note addModuleCleanup(): c42. were
          not called unless the user defines ‘tearDownModule()’ in their
          test module.

        * Functions registered with *note addClassCleanup(): c43. were
          not called if ‘tearDownClass’ is set to ‘None’.

        * Buffering in *note TestResult: 136f. did not work with
          functions registered with ‘addClassCleanup()’ and
          ‘addModuleCleanup()’.

        * Errors in functions registered with ‘addClassCleanup()’ and
          ‘addModuleCleanup()’ were not handled correctly in buffered
          and debug modes.

        * Errors in ‘setUpModule()’ and functions registered with
          ‘addModuleCleanup()’ were reported in wrong order.

        * And several lesser bugs.

   - bpo-45030(41): Fix integer overflow in pickling and copying the
     range iterator.

   - bpo-45001(42): Made email date parsing more robust against
     malformed input, namely a whitespace-only ‘Date:’ header.  Patch by
     Wouter Bolsterlee.

   - bpo-45010(43): Remove support of special method ‘__div__’ in *note
     unittest.mock: 10d.  It is not used in Python 3.

   - bpo-39218(44): Improve accuracy of variance calculations by using
     ‘x*x’ instead of ‘x**2’.

   - bpo-43613(45): Improve the speed of *note gzip.compress(): 84f. and
     *note gzip.decompress(): 1415. by compressing and decompressing at
     once in memory instead of in a streamed fashion.

   - bpo-37596(46): Ensure that *note set: 184. and *note frozenset:
     7f3. objects are always *note marshalled: 91. reproducibly.

   - bpo-44019(47): A new function ‘operator.call’ has been added, such
     that ‘operator.call(obj, *args, **kwargs) == obj(*args, **kwargs)’.

   - bpo-42255(48): ‘webbrowser.MacOSX’ is deprecated and will be
     removed in Python 3.13.  It is untested and undocumented and also
     not used by *note webbrowser: 11b. itself.  Patch by Donghee Na.

   - bpo-44955(49): Method *note stopTestRun(): 1552. is now always
     called in pair with method *note startTestRun(): 1551. for *note
     TestResult: 136f. objects implicitly created in *note run(): 136e.
     Previously it was not called for test methods and classes decorated
     with a skipping decorator.

   - bpo-39039(50): tarfile.open raises *note ReadError: 1c37. when a
     zlib error occurs during file extraction.

   - bpo-44935(51): *note subprocess: dc. on Solaris now also uses *note
     os.posix_spawn(): 52f. for better performance.

   - bpo-44911(52): *note IsolatedAsyncioTestCase: 361. will no longer
     throw an exception while cancelling leaked tasks.  Patch by Bar
     Harel.

   - bpo-41322(53): Added ‘DeprecationWarning’ for tests and async tests
     that return a value!=None (as this may indicate an improperly
     written test, for example a test written as a generator function).

   - bpo-44524(54): Make exception message more useful when subclass
     from typing special form alias.  Patch provided by Yurii Karabas.

   - bpo-38956(55): *note argparse.BooleanOptionalAction: 1bda.’s
     default value is no longer printed twice when used with *note
     argparse.ArgumentDefaultsHelpFormatter: 1c38.

   - bpo-44860(56): Fix the ‘posix_user’ scheme in *note sysconfig: e1.
     to not depend on *note sys.platlibdir: b34.

   - bpo-44859(57): Improve error handling in *note sqlite3: d4. and
     raise more accurate exceptions.

        * *note MemoryError: 1786. is now raised instead of *note
          sqlite3.Warning: 1b9e. when memory is not enough for encoding
          a statement to UTF-8 in ‘Connection.__call__()’ and
          ‘Cursor.execute()’.

        * ‘UnicodEncodeError’ is now raised instead of *note
          sqlite3.Warning: 1b9e. when the statement contains surrogate
          characters in ‘Connection.__call__()’ and ‘Cursor.execute()’.

        * *note TypeError: 198. is now raised instead of *note
          ValueError: 2ec. for non-string script argument in
          ‘Cursor.executescript()’.

        * *note ValueError: 2ec. is now raised for script containing the
          null character instead of truncating it in
          ‘Cursor.executescript()’.

        * Correctly handle exceptions raised when getting boolean value
          of the result of the progress handler.

        * Add many tests covering different corner cases.

   - bpo-44581(58): Upgrade bundled pip to 21.2.3 and setuptools to
     57.4.0

   - bpo-44849(59): Fix the *note os.set_inheritable(): 1100. function
     on FreeBSD 14 for file descriptor opened with the *note O_PATH:
     1174. flag: ignore the *note EBADF: b56. error on ‘ioctl()’,
     fallback on the ‘fcntl()’ implementation.  Patch by Victor Stinner.

   - bpo-44605(60): The @functools.total_ordering() decorator now works
     with metaclasses.

   - bpo-44524(61): Fixed an issue wherein the ‘__name__’ and
     ‘__qualname__’ attributes of subscribed specialforms could be
     ‘None’.

   - bpo-44839(62): *note MemoryError: 1786. raised in user-defined
     functions will now produce a ‘MemoryError’ in *note sqlite3: d4.
     *note OverflowError: a83. will now be converted to *note DataError:
     1c39.  Previously *note OperationalError: 1c3a. was produced in
     these cases.

   - bpo-44822(63): *note sqlite3: d4. user-defined functions and
     aggregators returning *note strings: 169. with embedded NUL
     characters are no longer truncated.  Patch by Erlend E. Aasland.

   - bpo-44801(64): Ensure that the *note ParamSpec: 488. variable in
     Callable can only be substituted with a parameters expression (a
     list of types, an ellipsis, ParamSpec or Concatenate).

   - bpo-44806(65): Non-protocol subclasses of *note typing.Protocol:
     56b. ignore now the ‘__init__’ method inherited from protocol base
     classes.

   - bpo-27275(66): *note collections.OrderedDict.popitem(): 14f5. and
     ‘collections.OrderedDict.pop()’ no longer call ‘__getitem__’ and
     ‘__delitem__’ methods of the OrderedDict subclasses.

   - bpo-44793(67): Fix checking the number of arguments when subscribe
     a generic type with ‘ParamSpec’ parameter.

   - bpo-44784(68): In importlib.metadata tests, override warnings
     behavior under expected DeprecationWarnings (importlib_metadata
     4.6.3).

   - bpo-44667(69): The *note tokenize.tokenize(): 701. doesn’t
     incorrectly generate a ‘NEWLINE’ token if the source doesn’t end
     with a new line character but the last line is a comment, as the
     function is already generating a ‘NL’ token.  Patch by Pablo
     Galindo

   - bpo-44771(70): Added ‘importlib.simple’ module implementing
     adapters from a low-level resources reader interface to a
     ‘TraversableResources’ interface.  Legacy API (‘path’, ‘contents’,
     …) is now supported entirely by the ‘.files()’ API with a
     compatibility shim supplied for resource loaders without that
     functionality.  Feature parity with ‘importlib_resources’ 5.2.

   - bpo-44752(71): ‘rcompleter’ does not call *note getattr(): dcc. on
     *note property: 4b4. objects to avoid the side-effect of evaluating
     the corresponding method.

   - bpo-44747(72): Refactor usage of ‘sys._getframe’ in ‘typing’
     module.  Patch provided by Yurii Karabas.

   - bpo-42378(73): Fixes the issue with log file being overwritten when
     *note logging.FileHandler: 1c3b. is used in *note atexit: d. with
     'filemode' set to ‘'w'’.  Note this will cause the message in
     'atexit' not being logged if the log stream is already closed due
     to shutdown of logging.

   - bpo-44720(74): ‘weakref.proxy’ objects referencing non-iterators
     now raise ‘TypeError’ rather than dereferencing the null
     ‘tp_iternext’ slot and crashing.

   - bpo-44704(75): The implementation of ‘collections.abc.Set._hash()’
     now matches that of ‘frozenset.__hash__()’.

   - bpo-44666(76): Fixed issue in *note compileall.compile_file(): fe3.
     when ‘sys.stdout’ is redirected.  Patch by Stefan Hölzl.

   - bpo-44688(77): *note sqlite3.Connection.create_collation(): 887.
     now accepts non-ASCII collation names.  Patch by Erlend E. Aasland.

   - bpo-44690(78): Adopt 'binacii.a2b_base64'’s strict mode in
     'base64.b64decode'.

   - bpo-42854(79): Fixed a bug in the ‘_ssl’ module that was throwing
     *note OverflowError: a83. when using ‘_ssl._SSLSocket.write()’ and
     ‘_ssl._SSLSocket.read()’ for a big value of the ‘len’ parameter.
     Patch by Pablo Galindo.

   - bpo-44686(80): Replace ‘unittest.mock._importer’ with
     ‘pkgutil.resolve_name’.

   - bpo-44353(81): Make ‘NewType.__call__’ faster by implementing it in
     C. Patch provided by Yurii Karabas.

   - bpo-44682(82): Change the *note pdb: aa. 'commands' directive to
     disallow setting commands for an invalid breakpoint and to display
     an appropriate error.

   - bpo-44353(83): Refactor ‘typing.NewType’ from function into
     callable class.  Patch provided by Yurii Karabas.

   - bpo-44678(84): Added a separate error message for discontinuous
     padding in 'binascii.a2b_base64' strict mode.

   - bpo-44524(85): Add missing ‘__name__’ and ‘__qualname__’ attributes
     to ‘typing’ module classes.  Patch provided by Yurii Karabas.

   - bpo-40897(86): Give priority to using the current class constructor
     in *note inspect.signature(): 22f.  Patch by Weipeng Hong.

   - bpo-44638(87): Add a reference to the zipp project and hint as to
     how to use it.

   - bpo-44648(88): Fixed wrong error being thrown by *note
     inspect.getsource(): 17ab. when examining a class in the
     interactive session.  Instead of *note TypeError: 198, it should be
     *note OSError: 2c0. with appropriate error message.

   - bpo-44608(89): Fix memory leak in ‘_tkinter._flatten()’ if it is
     called with a sequence or set, but not list or tuple.

   - bpo-44594(90): Fix an edge case of ‘ExitStack’ and ‘AsyncExitStack’
     exception chaining.  They will now match ‘with’ block behavior when
     ‘__context__’ is explicitly set to ‘None’ when the exception is in
     flight.

   - bpo-42799(91): In *note fnmatch: 60, the cache size for compiled
     regex patterns (*note functools.lru_cache(): be4.) was bumped up
     from 256 to 32768, affecting functions: *note fnmatch.fnmatch():
     1c3c, *note fnmatch.fnmatchcase(): 1c3d, *note fnmatch.filter():
     1c3e.

   - bpo-41928(92): Update *note shutil.copyfile(): c50. to raise *note
     FileNotFoundError: 264. instead of confusing *note
     IsADirectoryError: 125b. when a path ending with a ‘os.path.sep’
     does not exist; *note shutil.copy(): c51. and *note shutil.copy2():
     c52. are also affected.

   - bpo-44569(93): Added the ‘StackSummary.format_frame()’ function in
     *note traceback: 104.  This allows users to customize the way
     individual lines are formatted in tracebacks without
     re-implementing logic to handle recursive tracebacks.

   - bpo-44566(94): handle StopIteration subclass raised from
     @contextlib.contextmanager generator

   - bpo-44558(95): Make the implementation consistency of *note
     indexOf(): ada. between C and Python versions.  Patch by Donghee
     Na.

   - bpo-41249(96): Fixes ‘TypedDict’ to work with
     ‘typing.get_type_hints()’ and postponed evaluation of annotations
     across modules.

   - bpo-44554(97): Refactor argument processing in ‘pdb.main()’ to
     simplify detection of errors in input loading and clarify behavior
     around module or script invocation.

   - bpo-34798(98): Break up paragraph about *note pprint.PrettyPrinter:
     1181. construction parameters to make it easier to read.

   - bpo-44539(99): Added support for recognizing JPEG files without
     JFIF or Exif markers.

   - bpo-44461(100): Fix bug with *note pdb: aa.’s handling of import
     error due to a package which does not have a ‘__main__’ module

   - bpo-43625(101): Fix a bug in the detection of CSV file headers by
     *note csv.Sniffer.has_header(): 1c3f. and improve documentation of
     same.

   - bpo-44516(102): Update vendored pip to 21.1.3

   - bpo-42892(103): Fixed an exception thrown while parsing a malformed
     multipart email by *note email.message.EmailMessage: 580.

   - bpo-44468(104): *note typing.get_type_hints(): 8c1. now finds
     annotations in classes and base classes with unexpected
     ‘__module__’.  Previously, it skipped those MRO elements.

   - bpo-44491(105): Allow clearing the *note sqlite3: d4. authorizer
     callback by passing *note None: 886. to *note set_authorizer():
     5a9.  Patch by Erlend E. Aasland.

   - bpo-43977(106): Set the proper *note Py_TPFLAGS_MAPPING: 1c40. and
     *note Py_TPFLAGS_SEQUENCE: 1c41. flags for subclasses created
     before a parent has been registered as a *note
     collections.abc.Mapping: ac9. or *note collections.abc.Sequence:
     13cc.

   - bpo-44482(107): Fix very unlikely resource leak in *note glob: 68.
     in alternate Python implementations.

   - bpo-44466(108): The *note faulthandler: 5c. module now detects if a
     fatal error occurs during a garbage collector collection.  Patch by
     Victor Stinner.

   - bpo-44471(109): A *note TypeError: 198. is now raised instead of an
     *note AttributeError: 5f0. in *note
     contextlib.ExitStack.enter_context(): 7ef. and *note
     contextlib.AsyncExitStack.enter_async_context(): 7f0. for objects
     which do not support the *note context manager: 1e1. or *note
     asynchronous context manager: 7f1. protocols correspondingly.

   - bpo-44404(110): *note tkinter: f6.’s ‘after()’ method now supports
     callables without the ‘__name__’ attribute.

   - bpo-41546(111): Make *note pprint: b3. (like the builtin ‘print’)
     not attempt to write to ‘stdout’ when it is ‘None’.

   - bpo-44458(112): ‘BUFFER_BLOCK_SIZE’ is now declared static, to
     avoid linking collisions when bz2, lmza or zlib are statically
     linked.

   - bpo-44464(113): Remove exception for flake8 in deprecated
     importlib.metadata interfaces.  Sync with importlib_metadata 4.6.

   - bpo-44446(114): Take into account that ‘lineno’ might be ‘None’ in
     *note traceback.FrameSummary: 1086.

   - bpo-44439(115): Fix in ‘bz2.BZ2File.write()’ /
     ‘lzma.LZMAFile.write()’ methods, when the input data is an object
     that supports the buffer protocol, the file length may be wrong.

   - bpo-44434(116): _thread.start_new_thread() no longer calls
     PyThread_exit_thread() explicitly at the thread exit, the call was
     redundant.  On Linux with the glibc, pthread_exit() aborts the
     whole process if dlopen() fails to open libgcc_s.so file (ex:
     EMFILE error).  Patch by Victor Stinner.

   - bpo-42972(117): The _thread.RLock type now fully implement the GC
     protocol: add a traverse function and the *note Py_TPFLAGS_HAVE_GC:
     982. flag.  Patch by Victor Stinner.

   - bpo-44422(118): The *note threading.enumerate(): 1c42. function now
     uses a reentrant lock to prevent a hang on reentrant call.  Patch
     by Victor Stinner.

   - bpo-38291(119): Importing typing.io or typing.re now prints a
     ‘DeprecationWarning’.

   - bpo-37880(120): argparse actions store_const and append_const each
     receive a default value of ‘None’ when the ‘const’ kwarg is not
     provided.  Previously, this raised a *note TypeError: 198.

   - bpo-44389(121): Fix deprecation of *note ssl.OP_NO_TLSv1_3: 1c43.

   - bpo-27827(122): ‘pathlib.PureWindowsPath.is_reserved()’ now
     identifies a greater range of reserved filenames, including those
     with trailing spaces or colons.

   - bpo-44395(123): Fix ‘as_string()’ to pass unixfrom properly.  Patch
     by Donghee Na.

   - bpo-34266(124): Handle exceptions from parsing the arg of *note
     pdb: aa.’s run/restart command.

   - bpo-44362(125): Improve *note ssl: d5. module’s deprecation
     messages, error reporting, and documentation for deprecations.

   - bpo-44342(126): [Enum] Change pickling from by-value to by-name.

   - bpo-44356(127): [Enum] Allow multiple data-type mixins if they are
     all the same.

   - bpo-44351(128): Restore back ‘parse_makefile()’ in
     ‘distutils.sysconfig’ because it behaves differently than the
     similar implementation in *note sysconfig: e1.

   - bpo-35800(129): ‘smtpd.MailmanProxy’ is now removed as it is
     unusable without an external module, ‘mailman’.  Patch by Donghee
     Na.

   - bpo-44357(130): Added a function that returns cube root of the
     given number *note math.cbrt(): 872.

   - bpo-44339(131): Change ‘math.pow(±0.0, -math.inf)’ to return ‘inf’
     instead of raising ‘ValueError’.  This brings the special-case
     handling of ‘math.pow’ into compliance with the IEEE 754 standard.

   - bpo-44242(132): Remove missing flag check from Enum creation and
     move into a ‘verify’ decorator.

   - bpo-44246(133): In ‘importlib.metadata’, restore compatibility in
     the result from ‘Distribution.entry_points’ (‘EntryPoints’) to
     honor expectations in older implementations and issuing deprecation
     warnings for these cases: A. ‘EntryPoints’ objects are once again
     mutable, allowing for ‘sort()’ and other list-based mutation
     operations.  Avoid deprecation warnings by casting to a mutable
     sequence (e.g.  ‘list(dist.entry_points).sort()’).  B.
     ‘EntryPoints’ results once again allow for access by index.  To
     avoid deprecation warnings, cast the result to a Sequence first
     (e.g.  ‘tuple(dist.entry_points)[0]’).

   - bpo-44246(134): In importlib.metadata.entry_points, de-duplication
     of distributions no longer requires loading the full metadata for
     PathDistribution objects, improving entry point loading performance
     by ~10x.

   - bpo-43858(135): Added a function that returns a copy of a dict of
     logging levels: *note logging.getLevelNamesMapping(): 86a.

   - bpo-44260(136): The *note random.Random: 1c44. constructor no
     longer reads system entropy without need.

   - bpo-44254(137): On Mac, give turtledemo button text a color that
     works on both light or dark background.  Programmers cannot control
     the latter.

   - bpo-44258(138): Support PEP 515 for Fraction’s initialization from
     string.

   - bpo-44235(139): Remove deprecated functions in the *note gettext:
     67.  Patch by Donghee Na.

   - bpo-38693(140): Prefer f-strings to ‘.format’ in
     importlib.resources.

   - bpo-33693(141): Importlib.metadata now prefers f-strings to
     .format.

   - bpo-44241(142): Incorporate minor tweaks from importlib_metadata
     4.1: SimplePath protocol, support for Metadata 2.2.

   - bpo-43216(143): Remove the ‘@asyncio.coroutine’ *note decorator:
     93b. enabling legacy generator-based coroutines to be compatible
     with async/await code; remove ‘asyncio.coroutines.CoroWrapper’ used
     for wrapping legacy coroutine objects in the debug mode.  The
     decorator has been deprecated since Python 3.8 and the removal was
     initially scheduled for Python 3.10.  Patch by Illia Volochii.

   - bpo-44210(144): Make importlib.metadata._meta.PackageMetadata
     public.

   - bpo-43643(145): Declare readers.MultiplexedPath.name as a property
     per the spec.

   - bpo-27334(146): The *note sqlite3: d4. context manager now performs
     a rollback (thus releasing the database lock) if commit failed.
     Patch by Luca Citi and Erlend E. Aasland.

   - bpo-4928(147): Documented existing behavior on POSIX:
     NamedTemporaryFiles are not deleted when creating process is killed
     with SIGKILL

   - bpo-44154(148): Optimize *note fractions.Fraction: 213. pickling
     for large components.

   - bpo-33433(149): For IPv4 mapped IPv6 addresses ( RFC 4291(150)
     Section 2.5.5.2), the *note ipaddress.IPv6Address.is_private: 19ac.
     check is deferred to the mapped IPv4 address.  This solves a bug
     where public mapped IPv4 addresses were considered private by the
     IPv6 check.

   - bpo-44150(151): Add optional 'weights' argument to
     statistics.fmean().

   - bpo-44142(152): *note ast.unparse(): ae4. will now drop the
     redundant parentheses when tuples used as assignment targets (e.g
     in for loops).

   - bpo-44145(153): *note hmac: 6e. computations were not releasing the
     GIL while calling the OpenSSL ‘HMAC_Update’ C API (a new feature in
     3.9).  This unintentionally prevented parallel computation as other
     *note hashlib: 6c. algorithms support.

   - bpo-44095(154): *note zipfile.Path: 8d9. now supports *note
     zipfile.Path.stem: 8d6, *note zipfile.Path.suffixes: 8d8, and *note
     zipfile.Path.suffix: 8d7. attributes.

   - bpo-44077(155): It’s now possible to receive the type of service
     (ToS), a.k.a.  differentiated services (DS), a.k.a.  differentiated
     services code point (DSCP) and explicit congestion notification
     (ECN) IP header fields with ‘socket.IP_RECVTOS’.

   - bpo-37788(156): Fix a reference leak when a Thread object is never
     joined.

   - bpo-38908(157): Subclasses of ‘typing.Protocol’ which only have
     data variables declared will now raise a ‘TypeError’ when checked
     with ‘isinstance’ unless they are decorated with
     ‘runtime_checkable()’.  Previously, these checks passed silently.
     Patch provided by Yurii Karabas.

   - bpo-44098(158): ‘typing.ParamSpec’ will no longer be found in the
     ‘__parameters__’ of most *note typing: 10a. generics except in
     valid use locations specified by PEP 612(159).  This prevents
     incorrect usage like ‘typing.List[P][int]’.  This change means
     incorrect usage which may have passed silently in 3.10 beta 1 and
     earlier will now error.

   - bpo-44089(160): Allow subclassing ‘csv.Error’ in 3.10 (it was
     allowed in 3.9 and earlier but was disallowed in early versions of
     3.10).

   - bpo-44081(161): *note ast.unparse(): ae4. now doesn’t use redundant
     spaces to separate ‘lambda’ and the ‘:’ if there are no parameters.

   - bpo-44061(162): Fix regression in previous release when calling
     *note pkgutil.iter_modules(): f49. with a list of *note
     pathlib.Path: 266. objects

   - bpo-44059(163): Register the SerenityOS Browser in the *note
     webbrowser: 11b. module.

   - bpo-36515(164): The *note hashlib: 6c. module no longer does
     unaligned memory accesses when compiled for ARM platforms.

   - bpo-40465(165): Remove random module features deprecated in Python
     3.9.

   - bpo-44018(166): random.seed() no longer mutates bytearray inputs.

   - bpo-38352(167): Add ‘IO’, ‘BinaryIO’, ‘TextIO’, ‘Match’, and
     ‘Pattern’ to ‘typing.__all__’.  Patch by Jelle Zijlstra.

   - bpo-44002(168): *note urllib.parse: 110. now uses
     ‘functool.lru_cache()’ for its internal URL splitting and quoting
     caches instead of rolling its own like its the “90s.

     The undocumented internal *note urllib.parse: 110. ‘Quoted’ class
     API is now deprecated, for removal in 3.14.

   - bpo-43972(169): When *note http.server.SimpleHTTPRequestHandler:
     d3a. sends a ‘301 (Moved Permanently)’ for a directory path not
     ending with ‘/’, add a ‘Content-Length: 0’ header.  This improves
     the behavior for certain clients.

   - bpo-28528(170): Fix a bug in *note pdb: aa. where ‘checkline()’
     raises *note AttributeError: 5f0. if it is called after ‘reset()’.

   - bpo-43853(171): Improved string handling for *note sqlite3: d4.
     user-defined functions and aggregates:

        * It is now possible to pass strings with embedded null
          characters to UDFs

        * Conversion failures now correctly raise *note MemoryError:
          1786.

     Patch by Erlend E. Aasland.

   - bpo-43666(172): AIX: ‘Lib/_aix_support.get_platform()’ may fail in
     an AIX WPAR. The fileset bos.rte appears to have a builddate in
     both LPAR and WPAR so this fileset is queried rather than bos.mp64.
     To prevent a similar situation (no builddate in ODM) a value (9988)
     sufficient for completing a build is provided.  Patch by M Felt.

   - bpo-43650(173): Fix *note MemoryError: 1786. in *note
     shutil.unpack_archive(): 697. which fails inside
     ‘shutil._unpack_zipfile()’ on large files.  Patch by Igor
     Bolshakov.

   - bpo-43612(174): *note zlib.compress(): 850. now accepts a wbits
     parameter which allows users to compress data as a raw deflate
     block without zlib headers and trailers in one go.  Previously this
     required instantiating a ‘zlib.compressobj’.  It also provides a
     faster alternative to ‘gzip.compress’ when wbits=31 is used.

   - bpo-43392(175): ‘importlib._bootstrap._find_and_load()’ now
     implements a two-step check to avoid locking when modules have been
     already imported and are ready.  This improves performance of
     repeated calls to *note importlib.import_module(): 73d. and *note
     importlib.__import__(): 126f.

   - bpo-43318(176): Fix a bug where *note pdb: aa. does not always echo
     cleared breakpoints.

   - bpo-43234(177): Prohibit passing non-*note
     concurrent.futures.ThreadPoolExecutor: 94a. executors to
     ‘loop.set_default_executor()’ following a deprecation in Python
     3.8.  Patch by Illia Volochii.

   - bpo-43232(178): Prohibit previously deprecated potentially
     disruptive operations on ‘asyncio.trsock.TransportSocket’.  Patch
     by Illia Volochii.

   - bpo-30077(179): Added support for Apple’s aifc/sowt
     pseudo-compression

   - bpo-42971(180): Add definition of ‘errno.EQFULL’ for platforms that
     define this constant (such as macOS).

   - bpo-43086(181): Added a new optional ‘strict_mode’ parameter to
     'binascii.a2b_base64'.  When ‘scrict_mode’ is set to ‘True’, the
     'a2b_base64' function will accept only valid base64 content.  More
     details about what «valid base64 content» is, can be found in the
     function’s documentation.

   - bpo-43024(182): Improve the help signature of *note
     traceback.print_exception(): a51, *note
     traceback.format_exception(): a4f. and *note
     traceback.format_exception_only(): a50.

   - bpo-33809(183): Add the *note traceback.TracebackException.print():
     8b4. method which prints the formatted exception information.

   - bpo-42862(184): *note sqlite3: d4. now utilizes *note
     functools.lru_cache(): be4. to implement the connection statement
     cache.  As a small optimisation, the default statement cache size
     has been increased from 100 to 128.  Patch by Erlend E. Aasland.

   - bpo-41818(185): Soumendra Ganguly: add termios.tcgetwinsize(),
     termios.tcsetwinsize().

   - bpo-40497(186): *note subprocess.check_output(): 11c4. now raises
     *note ValueError: 2ec. when the invalid keyword argument 'check' is
     passed by user code.  Previously such use would fail later with a
     *note TypeError: 198.  Patch by Rémi Lapeyre.

   - bpo-37449(187): ‘ensurepip’ now uses ‘importlib.resources.files()’
     traversable APIs

   - bpo-40956(188): Use Argument Clinic in *note sqlite3: d4.  Patches
     by Erlend E. Aasland.

   - bpo-41730(189): ‘DeprecationWarning’ is now raised when importing
     ‘tkinter.tix’, which has been deprecated in documentation since
     Python 3.6.

   - bpo-20684(190): Remove unused ‘_signature_get_bound_param’ function
     from *note inspect: 82. - by Anthony Sottile.

   - bpo-41402(191): Fix *note email.message.EmailMessage.set_content():
     1c45. when called with binary data and ‘7bit’ content transfer
     encoding.

   - bpo-32695(192): The 'compresslevel' and 'preset' keyword arguments
     of *note tarfile.open(): 1079. are now both documented and tested.

   - bpo-41137(193): Use utf-8 encoding while reading .pdbrc files.
     Patch by Srinivas Reddy Thatiparthy

   - bpo-24391(194): Improved reprs of *note threading: f3.
     synchronization objects: *note Semaphore: 135e, *note
     BoundedSemaphore: 135f, *note Event: 1360. and *note Barrier: 13eb.

   - bpo-5846(195): Deprecated the following *note unittest: 10c.
     functions, scheduled for removal in Python 3.13:

        * ‘findTestCases()’

        * ‘makeSuite()’

        * ‘getTestCaseNames()’

     Use *note TestLoader: 593. methods instead:

        * *note unittest.TestLoader.loadTestsFromModule(): 594.

        * *note unittest.TestLoader.loadTestsFromTestCase(): 595.

        * *note unittest.TestLoader.getTestCaseNames(): 596.

     Patch by Erlend E. Aasland.

   - bpo-40563(196): Support pathlike objects on dbm/shelve.  Patch by
     Hakan Çelik and Henry-Joseph Audéoud.

   - bpo-34990(197): Fixed a Y2k38 bug in the compileall module where it
     would fail to compile files with a modification time after the year
     2038.

   - bpo-39549(198): Whereas the code for reprlib.Repr had previously
     used a hardcoded string value of “…”, this PR updates it to use of
     a “fillvalue” attribute, whose value defaults to “…” and can be
     reset in either individual reprlib.Repr instances or in subclasses
     thereof.

   - bpo-37022(199): *note pdb: aa. now displays exceptions from
     ‘repr()’ with its ‘p’ and ‘pp’ commands.

   - bpo-38840(200): Fix ‘test___all__’ on platforms lacking a shared
     memory implementation.

   - bpo-39359(201): Add one missing check that the password is a bytes
     object for an encrypted zipfile.

   - bpo-38741(202): *note configparser: 26.: using “]” inside a section
     header will no longer cut the section name short at the “]”

   - bpo-38415(203): Added missing behavior to *note
     contextlib.asynccontextmanager(): d21. to match *note
     contextlib.contextmanager(): 140a. so decorated functions can
     themselves be decorators.

   - bpo-30256(204): Pass multiprocessing BaseProxy argument
     ‘manager_owned’ through AutoProxy.

   - bpo-27513(205): *note email.utils.getaddresses(): 4f4. now accepts
     *note email.header.Header: 1c46. objects along with string values.
     Patch by Zackery Spytz.

   - bpo-16379(206): Add SQLite error code and name to *note sqlite3:
     d4. exceptions.  Patch by Aviv Palivoda, Daniel Shahaf, and Erlend
     E. Aasland.

   - bpo-26228(207): pty.spawn no longer hangs on FreeBSD, macOS, and
     Solaris.

   - bpo-33349(208): lib2to3 now recognizes async generators everywhere.

   - bpo-29298(209): Fix ‘TypeError’ when required subparsers without
     ‘dest’ do not receive arguments.  Patch by Anthony Sottile.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45371

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45329

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41710

   (4) https://bugs.python.org/issue?@action=redirect&bpo=1596321

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45274

   (6) https://bugs.python.org/issue?@action=redirect&bpo=21302

   (7) https://bugs.python.org/issue?@action=redirect&bpo=21302

   (8) https://bugs.python.org/issue?@action=redirect&bpo=45238

   (9) https://bugs.python.org/issue?@action=redirect&bpo=36674

   (10) https://bugs.python.org/issue?@action=redirect&bpo=45235

   (11) https://bugs.python.org/issue?@action=redirect&bpo=45183

   (12) https://bugs.python.org/issue?@action=redirect&bpo=45234

   (13) https://bugs.python.org/issue?@action=redirect&bpo=45228

   (14) https://bugs.python.org/issue?@action=redirect&bpo=45225

   (15) https://bugs.python.org/issue?@action=redirect&bpo=42135

   (16) https://bugs.python.org/issue?@action=redirect&bpo=20524

   (17) https://bugs.python.org/issue?@action=redirect&bpo=45168

   (18) https://bugs.python.org/issue?@action=redirect&bpo=21302

   (19) https://bugs.python.org/issue?@action=redirect&bpo=45173

   (20) https://bugs.python.org/issue?@action=redirect&bpo=44987

   (21) https://bugs.python.org/issue?@action=redirect&bpo=35474

   (22) https://bugs.python.org/issue?@action=redirect&bpo=45166

   (23) https://bugs.python.org/issue?@action=redirect&bpo=45162

   (24) https://bugs.python.org/issue?@action=redirect&bpo=38371

   (25) https://bugs.python.org/issue?@action=redirect&bpo=20499

   (26) https://bugs.python.org/issue?@action=redirect&bpo=45132

   (27) https://bugs.python.org/issue?@action=redirect&bpo=45129

   (28) https://bugs.python.org/issue?@action=redirect&bpo=45124

   (29) https://bugs.python.org/issue?@action=redirect&bpo=30856

   (30) https://bugs.python.org/issue?@action=redirect&bpo=45034

   (31) https://bugs.python.org/issue?@action=redirect&bpo=25894

   (32) https://bugs.python.org/issue?@action=redirect&bpo=45081

   (33) https://bugs.python.org/issue?@action=redirect&bpo=45085

   (34) https://bugs.python.org/issue?@action=redirect&bpo=40360

   (35) https://peps.python.org/pep-0617/

   (36) https://bugs.python.org/issue?@action=redirect&bpo=45075

   (37) https://bugs.python.org/issue?@action=redirect&bpo=31299

   (38) https://bugs.python.org/issue?@action=redirect&bpo=41620

   (39) https://bugs.python.org/issue?@action=redirect&bpo=45021

   (40) https://bugs.python.org/issue?@action=redirect&bpo=43913

   (41) https://bugs.python.org/issue?@action=redirect&bpo=45030

   (42) https://bugs.python.org/issue?@action=redirect&bpo=45001

   (43) https://bugs.python.org/issue?@action=redirect&bpo=45010

   (44) https://bugs.python.org/issue?@action=redirect&bpo=39218

   (45) https://bugs.python.org/issue?@action=redirect&bpo=43613

   (46) https://bugs.python.org/issue?@action=redirect&bpo=37596

   (47) https://bugs.python.org/issue?@action=redirect&bpo=44019

   (48) https://bugs.python.org/issue?@action=redirect&bpo=42255

   (49) https://bugs.python.org/issue?@action=redirect&bpo=44955

   (50) https://bugs.python.org/issue?@action=redirect&bpo=39039

   (51) https://bugs.python.org/issue?@action=redirect&bpo=44935

   (52) https://bugs.python.org/issue?@action=redirect&bpo=44911

   (53) https://bugs.python.org/issue?@action=redirect&bpo=41322

   (54) https://bugs.python.org/issue?@action=redirect&bpo=44524

   (55) https://bugs.python.org/issue?@action=redirect&bpo=38956

   (56) https://bugs.python.org/issue?@action=redirect&bpo=44860

   (57) https://bugs.python.org/issue?@action=redirect&bpo=44859

   (58) https://bugs.python.org/issue?@action=redirect&bpo=44581

   (59) https://bugs.python.org/issue?@action=redirect&bpo=44849

   (60) https://bugs.python.org/issue?@action=redirect&bpo=44605

   (61) https://bugs.python.org/issue?@action=redirect&bpo=44524

   (62) https://bugs.python.org/issue?@action=redirect&bpo=44839

   (63) https://bugs.python.org/issue?@action=redirect&bpo=44822

   (64) https://bugs.python.org/issue?@action=redirect&bpo=44801

   (65) https://bugs.python.org/issue?@action=redirect&bpo=44806

   (66) https://bugs.python.org/issue?@action=redirect&bpo=27275

   (67) https://bugs.python.org/issue?@action=redirect&bpo=44793

   (68) https://bugs.python.org/issue?@action=redirect&bpo=44784

   (69) https://bugs.python.org/issue?@action=redirect&bpo=44667

   (70) https://bugs.python.org/issue?@action=redirect&bpo=44771

   (71) https://bugs.python.org/issue?@action=redirect&bpo=44752

   (72) https://bugs.python.org/issue?@action=redirect&bpo=44747

   (73) https://bugs.python.org/issue?@action=redirect&bpo=42378

   (74) https://bugs.python.org/issue?@action=redirect&bpo=44720

   (75) https://bugs.python.org/issue?@action=redirect&bpo=44704

   (76) https://bugs.python.org/issue?@action=redirect&bpo=44666

   (77) https://bugs.python.org/issue?@action=redirect&bpo=44688

   (78) https://bugs.python.org/issue?@action=redirect&bpo=44690

   (79) https://bugs.python.org/issue?@action=redirect&bpo=42854

   (80) https://bugs.python.org/issue?@action=redirect&bpo=44686

   (81) https://bugs.python.org/issue?@action=redirect&bpo=44353

   (82) https://bugs.python.org/issue?@action=redirect&bpo=44682

   (83) https://bugs.python.org/issue?@action=redirect&bpo=44353

   (84) https://bugs.python.org/issue?@action=redirect&bpo=44678

   (85) https://bugs.python.org/issue?@action=redirect&bpo=44524

   (86) https://bugs.python.org/issue?@action=redirect&bpo=40897

   (87) https://bugs.python.org/issue?@action=redirect&bpo=44638

   (88) https://bugs.python.org/issue?@action=redirect&bpo=44648

   (89) https://bugs.python.org/issue?@action=redirect&bpo=44608

   (90) https://bugs.python.org/issue?@action=redirect&bpo=44594

   (91) https://bugs.python.org/issue?@action=redirect&bpo=42799

   (92) https://bugs.python.org/issue?@action=redirect&bpo=41928

   (93) https://bugs.python.org/issue?@action=redirect&bpo=44569

   (94) https://bugs.python.org/issue?@action=redirect&bpo=44566

   (95) https://bugs.python.org/issue?@action=redirect&bpo=44558

   (96) https://bugs.python.org/issue?@action=redirect&bpo=41249

   (97) https://bugs.python.org/issue?@action=redirect&bpo=44554

   (98) https://bugs.python.org/issue?@action=redirect&bpo=34798

   (99) https://bugs.python.org/issue?@action=redirect&bpo=44539

   (100) https://bugs.python.org/issue?@action=redirect&bpo=44461

   (101) https://bugs.python.org/issue?@action=redirect&bpo=43625

   (102) https://bugs.python.org/issue?@action=redirect&bpo=44516

   (103) https://bugs.python.org/issue?@action=redirect&bpo=42892

   (104) https://bugs.python.org/issue?@action=redirect&bpo=44468

   (105) https://bugs.python.org/issue?@action=redirect&bpo=44491

   (106) https://bugs.python.org/issue?@action=redirect&bpo=43977

   (107) https://bugs.python.org/issue?@action=redirect&bpo=44482

   (108) https://bugs.python.org/issue?@action=redirect&bpo=44466

   (109) https://bugs.python.org/issue?@action=redirect&bpo=44471

   (110) https://bugs.python.org/issue?@action=redirect&bpo=44404

   (111) https://bugs.python.org/issue?@action=redirect&bpo=41546

   (112) https://bugs.python.org/issue?@action=redirect&bpo=44458

   (113) https://bugs.python.org/issue?@action=redirect&bpo=44464

   (114) https://bugs.python.org/issue?@action=redirect&bpo=44446

   (115) https://bugs.python.org/issue?@action=redirect&bpo=44439

   (116) https://bugs.python.org/issue?@action=redirect&bpo=44434

   (117) https://bugs.python.org/issue?@action=redirect&bpo=42972

   (118) https://bugs.python.org/issue?@action=redirect&bpo=44422

   (119) https://bugs.python.org/issue?@action=redirect&bpo=38291

   (120) https://bugs.python.org/issue?@action=redirect&bpo=37880

   (121) https://bugs.python.org/issue?@action=redirect&bpo=44389

   (122) https://bugs.python.org/issue?@action=redirect&bpo=27827

   (123) https://bugs.python.org/issue?@action=redirect&bpo=44395

   (124) https://bugs.python.org/issue?@action=redirect&bpo=34266

   (125) https://bugs.python.org/issue?@action=redirect&bpo=44362

   (126) https://bugs.python.org/issue?@action=redirect&bpo=44342

   (127) https://bugs.python.org/issue?@action=redirect&bpo=44356

   (128) https://bugs.python.org/issue?@action=redirect&bpo=44351

   (129) https://bugs.python.org/issue?@action=redirect&bpo=35800

   (130) https://bugs.python.org/issue?@action=redirect&bpo=44357

   (131) https://bugs.python.org/issue?@action=redirect&bpo=44339

   (132) https://bugs.python.org/issue?@action=redirect&bpo=44242

   (133) https://bugs.python.org/issue?@action=redirect&bpo=44246

   (134) https://bugs.python.org/issue?@action=redirect&bpo=44246

   (135) https://bugs.python.org/issue?@action=redirect&bpo=43858

   (136) https://bugs.python.org/issue?@action=redirect&bpo=44260

   (137) https://bugs.python.org/issue?@action=redirect&bpo=44254

   (138) https://bugs.python.org/issue?@action=redirect&bpo=44258

   (139) https://bugs.python.org/issue?@action=redirect&bpo=44235

   (140) https://bugs.python.org/issue?@action=redirect&bpo=38693

   (141) https://bugs.python.org/issue?@action=redirect&bpo=33693

   (142) https://bugs.python.org/issue?@action=redirect&bpo=44241

   (143) https://bugs.python.org/issue?@action=redirect&bpo=43216

   (144) https://bugs.python.org/issue?@action=redirect&bpo=44210

   (145) https://bugs.python.org/issue?@action=redirect&bpo=43643

   (146) https://bugs.python.org/issue?@action=redirect&bpo=27334

   (147) https://bugs.python.org/issue?@action=redirect&bpo=4928

   (148) https://bugs.python.org/issue?@action=redirect&bpo=44154

   (149) https://bugs.python.org/issue?@action=redirect&bpo=33433

   (150) https://datatracker.ietf.org/doc/html/rfc4291.html

   (151) https://bugs.python.org/issue?@action=redirect&bpo=44150

   (152) https://bugs.python.org/issue?@action=redirect&bpo=44142

   (153) https://bugs.python.org/issue?@action=redirect&bpo=44145

   (154) https://bugs.python.org/issue?@action=redirect&bpo=44095

   (155) https://bugs.python.org/issue?@action=redirect&bpo=44077

   (156) https://bugs.python.org/issue?@action=redirect&bpo=37788

   (157) https://bugs.python.org/issue?@action=redirect&bpo=38908

   (158) https://bugs.python.org/issue?@action=redirect&bpo=44098

   (159) https://peps.python.org/pep-0612/

   (160) https://bugs.python.org/issue?@action=redirect&bpo=44089

   (161) https://bugs.python.org/issue?@action=redirect&bpo=44081

   (162) https://bugs.python.org/issue?@action=redirect&bpo=44061

   (163) https://bugs.python.org/issue?@action=redirect&bpo=44059

   (164) https://bugs.python.org/issue?@action=redirect&bpo=36515

   (165) https://bugs.python.org/issue?@action=redirect&bpo=40465

   (166) https://bugs.python.org/issue?@action=redirect&bpo=44018

   (167) https://bugs.python.org/issue?@action=redirect&bpo=38352

   (168) https://bugs.python.org/issue?@action=redirect&bpo=44002

   (169) https://bugs.python.org/issue?@action=redirect&bpo=43972

   (170) https://bugs.python.org/issue?@action=redirect&bpo=28528

   (171) https://bugs.python.org/issue?@action=redirect&bpo=43853

   (172) https://bugs.python.org/issue?@action=redirect&bpo=43666

   (173) https://bugs.python.org/issue?@action=redirect&bpo=43650

   (174) https://bugs.python.org/issue?@action=redirect&bpo=43612

   (175) https://bugs.python.org/issue?@action=redirect&bpo=43392

   (176) https://bugs.python.org/issue?@action=redirect&bpo=43318

   (177) https://bugs.python.org/issue?@action=redirect&bpo=43234

   (178) https://bugs.python.org/issue?@action=redirect&bpo=43232

   (179) https://bugs.python.org/issue?@action=redirect&bpo=30077

   (180) https://bugs.python.org/issue?@action=redirect&bpo=42971

   (181) https://bugs.python.org/issue?@action=redirect&bpo=43086

   (182) https://bugs.python.org/issue?@action=redirect&bpo=43024

   (183) https://bugs.python.org/issue?@action=redirect&bpo=33809

   (184) https://bugs.python.org/issue?@action=redirect&bpo=42862

   (185) https://bugs.python.org/issue?@action=redirect&bpo=41818

   (186) https://bugs.python.org/issue?@action=redirect&bpo=40497

   (187) https://bugs.python.org/issue?@action=redirect&bpo=37449

   (188) https://bugs.python.org/issue?@action=redirect&bpo=40956

   (189) https://bugs.python.org/issue?@action=redirect&bpo=41730

   (190) https://bugs.python.org/issue?@action=redirect&bpo=20684

   (191) https://bugs.python.org/issue?@action=redirect&bpo=41402

   (192) https://bugs.python.org/issue?@action=redirect&bpo=32695

   (193) https://bugs.python.org/issue?@action=redirect&bpo=41137

   (194) https://bugs.python.org/issue?@action=redirect&bpo=24391

   (195) https://bugs.python.org/issue?@action=redirect&bpo=5846

   (196) https://bugs.python.org/issue?@action=redirect&bpo=40563

   (197) https://bugs.python.org/issue?@action=redirect&bpo=34990

   (198) https://bugs.python.org/issue?@action=redirect&bpo=39549

   (199) https://bugs.python.org/issue?@action=redirect&bpo=37022

   (200) https://bugs.python.org/issue?@action=redirect&bpo=38840

   (201) https://bugs.python.org/issue?@action=redirect&bpo=39359

   (202) https://bugs.python.org/issue?@action=redirect&bpo=38741

   (203) https://bugs.python.org/issue?@action=redirect&bpo=38415

   (204) https://bugs.python.org/issue?@action=redirect&bpo=30256

   (205) https://bugs.python.org/issue?@action=redirect&bpo=27513

   (206) https://bugs.python.org/issue?@action=redirect&bpo=16379

   (207) https://bugs.python.org/issue?@action=redirect&bpo=26228

   (208) https://bugs.python.org/issue?@action=redirect&bpo=33349

   (209) https://bugs.python.org/issue?@action=redirect&bpo=29298


File: python.info,  Node: Documentation<35>,  Next: Tests<35>,  Prev: Library<115>,  Up: Python 3 11 0 alpha 1

1.24.41.22 Documentation
........................

   - bpo-45216(1): Remove extra documentation listing methods in
     ‘difflib’.  It was rendering twice in pydoc and was outdated in
     some places.

   - bpo-45024(2): *note collections.abc: 1f. documentation has been
     expanded to explicitly cover how instance and subclass checks work,
     with additional doctest examples and an exhaustive list of ABCs
     which test membership purely by presence of the right *note special
     method: 1c48.s.  Patch by Raymond Hettinger.

   - bpo-44957(3): Promote PEP 604 union syntax by using it where
     possible.  Also, mention ‘X | Y’ more prominently in section about
     ‘Union’ and mention ‘X | None’ at all in section about ‘Optional’.

   - bpo-16580(4): Added code equivalents for the *note int.to_bytes():
     1c1a. and *note int.from_bytes(): 1bd1. methods, as well as tests
     ensuring that these code equivalents are valid.

   - bpo-44903(5): Removed the ‘othergui.rst’ file, any references to
     it, and the list of GUI frameworks in the FAQ. In their place I’ve
     added links to the Python Wiki page on GUI frameworks(6).

   - bpo-33479(7): Tkinter documentation has been greatly expanded with
     new «Architecture» and «Threading model» sections.

   - bpo-36700(8): *note base64: f. RFC references were updated to point
     to RFC 4648(9); a section was added to point users to the new
     «security considerations» section of the RFC.

   - bpo-44740(10): Replaced occurrences of uppercase «Web» and
     «Internet» with lowercase versions per the 2016 revised Associated
     Press Style Book.

   - bpo-44693(11): Update the definition of __future__ in the glossary
     by replacing the confusing word «pseudo-module» with a more
     accurate description.

   - bpo-35183(12): Add typical examples to os.path.splitext docs

   - bpo-30511(13): Clarify that *note shutil.make_archive(): 6db. is
     not thread-safe due to reliance on changing the current working
     directory.

   - bpo-44561(14): Update of three expired hyperlinks in
     Doc/distributing/index.rst: «Project structure», «Building and
     packaging the project», and «Uploading the project to the Python
     Packaging Index».

   - bpo-44651(15): Delete entry «coercion» in Doc/glossary.rst for its
     outdated definition.

   - bpo-42958(16): Updated the docstring and docs of *note
     filecmp.cmp(): 19c5. to be more accurate and less confusing
     especially in respect to 'shallow' arg.

   - bpo-44631(17): Refactored the ‘repr()’ code of the ‘_Environ’ (os
     module).

   - bpo-44613(18): importlib.metadata is no longer provisional.

   - bpo-44558(19): Match the docstring and python implementation of
     *note countOf(): adb. to the behavior of its c implementation.

   - bpo-44544(20): List all kwargs for *note textwrap.wrap(): 16ce,
     *note textwrap.fill(): 16cd, and *note textwrap.shorten(): 11d2.
     Now, there are nav links to attributes of ‘TextWrap’, which makes
     navigation much easier while minimizing duplication in the
     documentation.

   - bpo-38062(21): Clarify that atexit uses equality comparisons
     internally.

   - bpo-40620(22): Convert examples in tutorial controlflow.rst section
     4.3 to be interpreter-demo style.

   - bpo-43066(23): Added a warning to *note zipfile: 137. docs:
     filename arg with a leading slash may cause archive to be
     un-openable on Windows systems.

   - bpo-39452(24): Rewrote ‘Doc/library/__main__.rst’.  Broadened scope
     of the document to explicitly discuss and differentiate between
     ‘__main__.py’ in packages versus the ‘__name__ == '__main__'’
     expression (and the idioms that surround it).

   - bpo-13814(25): In the Design FAQ, answer «Why don’t generators
     support the with statement?»

   - bpo-27752(26): Documentation of csv.Dialect is more descriptive.

   - bpo-44453(27): Fix documentation for the return type of *note
     sysconfig.get_path(): 1535.

   - bpo-44392(28): Added a new section in the C API documentation for
     types used in type hinting.  Documented ‘Py_GenericAlias’ and
     ‘Py_GenericAliasType’.

   - bpo-38291(29): Mark ‘typing.io’ and ‘typing.re’ as deprecated since
     Python 3.8 in the documentation.  They were never properly
     supported by type checkers.

   - bpo-44322(30): Document that SyntaxError args have a details tuple
     and that details are adjusted for errors in f-string field
     replacement expressions.

   - bpo-42392(31): Document the deprecation and removal of the ‘loop’
     parameter for many functions and classes in *note asyncio: b.

   - bpo-44195(32): Corrected references to ‘TraversableResources’ in
     docs.  There is no ‘TraversableReader’.

   - bpo-41963(33): Document that ‘ConfigParser’ strips off comments
     when reading configuration files.

   - bpo-44072(34): Correct where in the numeric ABC hierarchy ‘**’
     support is added, i.e., in numbers.Complex, not numbers.Integral.

   - bpo-43558(35): Add the remark to *note dataclasses: 33.
     documentation that the ‘__init__()’ of any base class has to be
     called in ‘__post_init__()’, along with a code example.

   - bpo-44025(36): Clarify when “_” in match statements is a keyword,
     and when not.

   - bpo-41706(37): Fix docs about how methods like ‘__add__’ are
     invoked when evaluating operator expressions.

   - bpo-41621(38): Document that *note collections.defaultdict: 13c4.
     parameter ‘default_factory’ defaults to ‘None’ and is
     positional-only.

   - bpo-41576(39): document BaseException in favor of bare except

   - bpo-21760(40): The description for __file__ fixed.  Patch by Furkan
     Onder

   - bpo-39498(41): Add a «Security Considerations» index which links to
     standard library modules that have explicitly documented security
     considerations.

   - bpo-33479(42): Remove the unqualified claim that tkinter is
     threadsafe.  It has not been true for several years and likely
     never was.  An explanation of what is true may be added later,
     after more discussion, and possibly after patching _tkinter.c,

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45216

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45024

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44957

   (4) https://bugs.python.org/issue?@action=redirect&bpo=16580

   (5) https://bugs.python.org/issue?@action=redirect&bpo=44903

   (6) https://wiki.python.org/moin/GuiProgramming

   (7) https://bugs.python.org/issue?@action=redirect&bpo=33479

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36700

   (9) https://datatracker.ietf.org/doc/html/rfc4648.html

   (10) https://bugs.python.org/issue?@action=redirect&bpo=44740

   (11) https://bugs.python.org/issue?@action=redirect&bpo=44693

   (12) https://bugs.python.org/issue?@action=redirect&bpo=35183

   (13) https://bugs.python.org/issue?@action=redirect&bpo=30511

   (14) https://bugs.python.org/issue?@action=redirect&bpo=44561

   (15) https://bugs.python.org/issue?@action=redirect&bpo=44651

   (16) https://bugs.python.org/issue?@action=redirect&bpo=42958

   (17) https://bugs.python.org/issue?@action=redirect&bpo=44631

   (18) https://bugs.python.org/issue?@action=redirect&bpo=44613

   (19) https://bugs.python.org/issue?@action=redirect&bpo=44558

   (20) https://bugs.python.org/issue?@action=redirect&bpo=44544

   (21) https://bugs.python.org/issue?@action=redirect&bpo=38062

   (22) https://bugs.python.org/issue?@action=redirect&bpo=40620

   (23) https://bugs.python.org/issue?@action=redirect&bpo=43066

   (24) https://bugs.python.org/issue?@action=redirect&bpo=39452

   (25) https://bugs.python.org/issue?@action=redirect&bpo=13814

   (26) https://bugs.python.org/issue?@action=redirect&bpo=27752

   (27) https://bugs.python.org/issue?@action=redirect&bpo=44453

   (28) https://bugs.python.org/issue?@action=redirect&bpo=44392

   (29) https://bugs.python.org/issue?@action=redirect&bpo=38291

   (30) https://bugs.python.org/issue?@action=redirect&bpo=44322

   (31) https://bugs.python.org/issue?@action=redirect&bpo=42392

   (32) https://bugs.python.org/issue?@action=redirect&bpo=44195

   (33) https://bugs.python.org/issue?@action=redirect&bpo=41963

   (34) https://bugs.python.org/issue?@action=redirect&bpo=44072

   (35) https://bugs.python.org/issue?@action=redirect&bpo=43558

   (36) https://bugs.python.org/issue?@action=redirect&bpo=44025

   (37) https://bugs.python.org/issue?@action=redirect&bpo=41706

   (38) https://bugs.python.org/issue?@action=redirect&bpo=41621

   (39) https://bugs.python.org/issue?@action=redirect&bpo=41576

   (40) https://bugs.python.org/issue?@action=redirect&bpo=21760

   (41) https://bugs.python.org/issue?@action=redirect&bpo=39498

   (42) https://bugs.python.org/issue?@action=redirect&bpo=33479


File: python.info,  Node: Tests<35>,  Next: Build<42>,  Prev: Documentation<35>,  Up: Python 3 11 0 alpha 1

1.24.41.23 Tests
................

   - bpo-40173(1): Fix *note
     test.support.import_helper.import_fresh_module(): 1c4a.

   - bpo-45280(2): Add a test case for empty *note typing.NamedTuple:
     331.

   - bpo-45269(3): Cover case when invalid ‘markers’ type is supplied to
     ‘c_make_encoder’.

   - bpo-45128(4): Fix ‘test_multiprocessing_fork’ failure due to
     ‘test_logging’ and ‘sys.modules’ manipulation.

   - bpo-45209(5): Fix ‘UserWarning: resource_tracker’ warning in
     ‘_test_multiprocessing._TestSharedMemory.test_shared_memory_cleaned_after_process_termination’

   - bpo-45185(6): Enables ‘TestEnumerations’ test cases in ‘test_ssl’
     suite.

   - bpo-45195(7): Fix test_readline.test_nonascii(): sometimes, the
     newline character is not written at the end, so don’t expect it in
     the output.  Patch by Victor Stinner.

   - bpo-45156(8): Fixes infinite loop on *note unittest.mock.seal():
     d9c. of mocks created by ‘create_autospec()’.

   - bpo-45125(9): Improves pickling tests and docs of ‘SharedMemory’
     and ‘SharableList’ objects.

   - bpo-44860(10): Update ‘test_sysconfig.test_user_similar()’ for the
     posix_user scheme: ‘platlib’ doesn’t use *note sys.platlibdir: b34.
     Patch by Victor Stinner.

   - bpo-45052(11):
     ‘WithProcessesTestSharedMemory.test_shared_memory_basics’ test was
     ignored, because ‘self.assertEqual(sms.size, sms2.size)’ line was
     failing.  It is now removed and test is unskipped.

     The main motivation for this line to be removed from the test is
     that the ‘size’ of ‘SharedMemory’ is not ever guaranteed to be the
     same.  It is decided by the platform.

   - bpo-44895(12): libregrtest now clears the type cache later to
     reduce the risk of false alarm when checking for reference leaks.
     Previously, the type cache was cleared too early and libregrtest
     raised a false alarm about reference leaks under very specific
     conditions.  Patch by Irit Katriel and Victor Stinner.

   - bpo-45042(13): Fixes that test classes decorated with
     ‘@hashlib_helper.requires_hashdigest’ were skipped all the time.

   - bpo-25130(14): Add calls of *note gc.collect(): 1b3. in tests to
     support PyPy.

   - bpo-45011(15): Made tests relying on the ‘_asyncio’ C extension
     module optional to allow running on alternative Python
     implementations.  Patch by Serhiy Storchaka.

   - bpo-44949(16): Fix auto history tests of test_readline: sometimes,
     the newline character is not written at the end, so don’t expect it
     in the output.

   - bpo-44891(17): Tests were added to clarify *note id(): 162a. is
     preserved when ‘obj * 1’ is used on *note str: 169. and *note
     bytes: 192. objects.  Patch by Nikita Sobolev.

   - bpo-44852(18): Add ability to wholesale silence DeprecationWarnings
     while running the regression test suite.

   - bpo-40928(19): Notify users running test_decimal regression tests
     on macOS of potential harmless «malloc can’t allocate region»
     messages spewed by test_decimal.

   - bpo-44734(20): Fixed floating-point precision issue in turtle
     tests.

   - bpo-44708(21): Regression tests, when run with -w, are now
     re-running only the affected test methods instead of re-running the
     entire test file.

   - bpo-42095(22): Added interop tests for Apple plists: generate plist
     files with Python plistlib and parse with Apple plutil; and the
     other way round.

   - bpo-44647(23): Added a permanent Unicode-valued environment
     variable to regression tests to ensure they handle this use case in
     the future.  If your test environment breaks because of that,
     report a bug to us, and temporarily set
     PYTHONREGRTEST_UNICODE_GUARD=0 in your test environment.

   - bpo-44515(24): Adjust recently added contextlib tests to avoid
     assuming the use of a refcounted GC

   - bpo-44287(25): Fix asyncio test_popen() of test_windows_utils by
     using a longer timeout.  Use military grade battle-tested *note
     test.support.SHORT_TIMEOUT: 1c4b. timeout rather than a hardcoded
     timeout of 10 seconds: it’s 30 seconds by default, but it is made
     longer on slow buildbots.  Patch by Victor Stinner.

   - bpo-44451(26): Reset ‘DeprecationWarning’ filters in
     ‘test.test_importlib.test_metadata_api.APITests.test_entry_points_by_index’
     to avoid ‘StopIteration’ error if ‘DeprecationWarnings’ are
     ignored.

   - bpo-44363(27): Account for address sanitizer in test_capi.
     test_capi now passes when run GCC address sanitizer.

   - bpo-44364(28): Add non integral tests for *note math.sqrt(): bfb.
     function.

   - bpo-43921(29): Fix test_ssl.test_wrong_cert_tls13(): use
     ‘suppress_ragged_eofs=False’, since ‘read()’ can raise *note
     ssl.SSLEOFError: 1aa0. on Windows.  Patch by Victor Stinner.

   - bpo-43921(30): Fix test_pha_required_nocert() of test_ssl: catch
     two more EOF cases (when the ‘recv()’ method returns an empty
     string).  Patch by Victor Stinner.

   - bpo-44131(31): Add test_frozenmain to test_embed to test the
     ‘Py_FrozenMain()’ C function.  Patch by Victor Stinner.

   - bpo-31904(32): Ignore error string case in test_file_not_exists().

   - bpo-42083(33): Add test to check that ‘PyStructSequence_NewType’
     accepts a ‘PyStructSequence_Desc’ with ‘doc’ field set to ‘NULL’.

   - bpo-35753(34): Fix crash in doctest when doctest parses modules
     that include unwrappable functions by skipping those functions.

   - bpo-30256(35): Add test for nested queues when using
     ‘multiprocessing’ shared objects ‘AutoProxy[Queue]’ inside
     ‘ListProxy’ and ‘DictProxy’

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40173

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45280

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45269

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45128

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45209

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45185

   (7) https://bugs.python.org/issue?@action=redirect&bpo=45195

   (8) https://bugs.python.org/issue?@action=redirect&bpo=45156

   (9) https://bugs.python.org/issue?@action=redirect&bpo=45125

   (10) https://bugs.python.org/issue?@action=redirect&bpo=44860

   (11) https://bugs.python.org/issue?@action=redirect&bpo=45052

   (12) https://bugs.python.org/issue?@action=redirect&bpo=44895

   (13) https://bugs.python.org/issue?@action=redirect&bpo=45042

   (14) https://bugs.python.org/issue?@action=redirect&bpo=25130

   (15) https://bugs.python.org/issue?@action=redirect&bpo=45011

   (16) https://bugs.python.org/issue?@action=redirect&bpo=44949

   (17) https://bugs.python.org/issue?@action=redirect&bpo=44891

   (18) https://bugs.python.org/issue?@action=redirect&bpo=44852

   (19) https://bugs.python.org/issue?@action=redirect&bpo=40928

   (20) https://bugs.python.org/issue?@action=redirect&bpo=44734

   (21) https://bugs.python.org/issue?@action=redirect&bpo=44708

   (22) https://bugs.python.org/issue?@action=redirect&bpo=42095

   (23) https://bugs.python.org/issue?@action=redirect&bpo=44647

   (24) https://bugs.python.org/issue?@action=redirect&bpo=44515

   (25) https://bugs.python.org/issue?@action=redirect&bpo=44287

   (26) https://bugs.python.org/issue?@action=redirect&bpo=44451

   (27) https://bugs.python.org/issue?@action=redirect&bpo=44363

   (28) https://bugs.python.org/issue?@action=redirect&bpo=44364

   (29) https://bugs.python.org/issue?@action=redirect&bpo=43921

   (30) https://bugs.python.org/issue?@action=redirect&bpo=43921

   (31) https://bugs.python.org/issue?@action=redirect&bpo=44131

   (32) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (33) https://bugs.python.org/issue?@action=redirect&bpo=42083

   (34) https://bugs.python.org/issue?@action=redirect&bpo=35753

   (35) https://bugs.python.org/issue?@action=redirect&bpo=30256


File: python.info,  Node: Build<42>,  Next: Windows<36>,  Prev: Tests<35>,  Up: Python 3 11 0 alpha 1

1.24.41.24 Build
................

   - bpo-45220(1): Avoid building with the Windows 11 SDK previews
     automatically.  This may be overridden by setting the
     ‘DefaultWindowsSDKVersion’ environment variable before building.

   - bpo-45020(2): Freeze stdlib modules that are imported during
     startup.  This provides significant performance improvements to
     startup.  If necessary, use the previously added «-X
     frozen_modules=off» commandline option to force importing the
     source modules.

   - bpo-45188(3): Windows builds now regenerate frozen modules as the
     first part of the build.  Previously the regeneration was later in
     the build, which would require it to be restarted if any modules
     had changed.

   - bpo-45163(4): Fixes Haiku platform build.

   - bpo-45067(5): The ncurses function extended_color_content was
     introduced in 2017

     (‘https://invisible-island.net/ncurses/NEWS.html#index-t20170401’).
     The

     ncurses-devel package in CentOS 7 had a older version ncurses
     resulted in compilation error.  For compiling ncurses with extended
     color support, we verify the version of the ncurses library >=
     20170401.

   - bpo-45019(6): Generate lines in relevant files for frozen modules.
     Up until now each of the files had to be edited manually.  This
     change makes it easier to add to and modify the frozen modules.

   - bpo-44340(7): Add support for building with clang thin lto via
     –with-lto=thin/full.  Patch by Donghee Na and Brett Holman.

   - bpo-44535(8): Enable building using a Visual Studio 2022 install on
     Windows.

   - bpo-43298(9): Improved error message when building without a
     Windows SDK installed.

   - bpo-44381(10): The Windows build now accepts
     ‘EnableControlFlowGuard’ set to ‘guard’ to enable CFG.

   - bpo-41282(11): Fix broken ‘make install’ that caused standard
     library extension modules to be unnecessarily and incorrectly
     rebuilt during the install phase of cpython.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45220

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45020

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45188

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45163

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45067

   (6) https://bugs.python.org/issue?@action=redirect&bpo=45019

   (7) https://bugs.python.org/issue?@action=redirect&bpo=44340

   (8) https://bugs.python.org/issue?@action=redirect&bpo=44535

   (9) https://bugs.python.org/issue?@action=redirect&bpo=43298

   (10) https://bugs.python.org/issue?@action=redirect&bpo=44381

   (11) https://bugs.python.org/issue?@action=redirect&bpo=41282


File: python.info,  Node: Windows<36>,  Next: macOS<26>,  Prev: Build<42>,  Up: Python 3 11 0 alpha 1

1.24.41.25 Windows
..................

   - bpo-45375(1): Fixes an assertion failure due to searching for the
     standard library in unnormalised paths.

   - bpo-45022(2): Update Windows release to include libffi 3.4.2

   - bpo-45007(3): Update to OpenSSL 1.1.1l in Windows build

   - bpo-44848(4): Upgrade Windows installer to use SQLite 3.36.0.

   - bpo-44572(5): Avoid consuming standard input in the *note platform:
     af. module

   - bpo-44582(6): Accelerate speed of *note mimetypes: 93.
     initialization using a native implementation of the registry scan.

   - bpo-41299(7): Fix 16 milliseconds jitter when using timeouts in
     *note threading: f3, such as with *note threading.Lock.acquire():
     8a8. or *note threading.Condition.wait(): 1c4e.

   - bpo-42686(8): Build *note sqlite3: d4. with math functions enabled.
     Patch by Erlend E. Aasland.

   - bpo-40263(9): This is a follow-on bug from
     ‘https://bugs.python.org/issue26903’.  Once that is applied we run
     into an off-by-one assertion problem.  The assert was not correct.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45375

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45022

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45007

   (4) https://bugs.python.org/issue?@action=redirect&bpo=44848

   (5) https://bugs.python.org/issue?@action=redirect&bpo=44572

   (6) https://bugs.python.org/issue?@action=redirect&bpo=44582

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41299

   (8) https://bugs.python.org/issue?@action=redirect&bpo=42686

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40263


File: python.info,  Node: macOS<26>,  Next: IDLE<19>,  Prev: Windows<36>,  Up: Python 3 11 0 alpha 1

1.24.41.26 macOS
................

   - bpo-45007(1): Update macOS installer builds to use OpenSSL 1.1.1l.

   - bpo-34602(2): When building CPython on macOS with ‘./configure
     --with-undefined-behavior-sanitizer --with-pydebug’, the stack size
     is now quadrupled to allow for the entire test suite to pass.

   - bpo-44848(3): Update macOS installer to use SQLite 3.36.0.

   - bpo-44689(4): *note ctypes.util.find_library(): f47. now works
     correctly on macOS 11 Big Sur even if Python is built on an older
     version of macOS. Previously, when built on older macOS systems,
     ‘find_library’ was not able to find macOS system libraries when
     running on Big Sur due to changes in how system libraries are
     stored.

   - bpo-41972(5): The framework build’s user header path in sysconfig
     is changed to add a “pythonX.Y” component to match distutils’s
     behavior.

   - bpo-43109(6): Allow –with-lto configure option to work with
     Apple-supplied Xcode or Command Line Tools.

   - bpo-34932(7): Add socket.TCP_KEEPALIVE support for macOS. Patch by
     Shane Harvey.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45007

   (2) https://bugs.python.org/issue?@action=redirect&bpo=34602

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44848

   (4) https://bugs.python.org/issue?@action=redirect&bpo=44689

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41972

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43109

   (7) https://bugs.python.org/issue?@action=redirect&bpo=34932


File: python.info,  Node: IDLE<19>,  Next: Tools/Demos<27>,  Prev: macOS<26>,  Up: Python 3 11 0 alpha 1

1.24.41.27 IDLE
...............

   - bpo-45296(1): On Windows, change exit/quit message to suggest
     Ctrl-D, which works, instead of <Ctrl-Z Return>, which does not
     work in IDLE.

   - bpo-45193(2): Make completion boxes appear on Ubuntu again.

   - bpo-40128(3): Mostly fix completions on macOS when not using tcl/tk
     8.6.11 (as with 3.9).  The added update_idletask call should be
     harmless and possibly helpful otherwise.

   - bpo-33962(4): Move the indent space setting from the Font tab to
     the new Windows tab.  Patch by Mark Roseman and Terry Jan Reedy.

   - bpo-40468(5): Split the settings dialog General tab into Windows
     and Shell/ED tabs.  Move help sources, which extend the Help menu,
     to the Extensions tab.  Make space for new options and shorten the
     dialog.  The latter makes the dialog better fit small screens.

   - bpo-41611(6): Avoid uncaught exceptions in
     ‘AutoCompleteWindow.winconfig_event()’.

   - bpo-41611(7): Fix IDLE sometimes freezing upon tab-completion on
     macOS.

   - bpo-44010(8): Highlight the new *note match: a10. statement’s *note
     soft keywords: a0f.: *note match: a10, *note case: a10, and *note
     _: a11.  However, this highlighting is not perfect and will be
     incorrect in some rare cases, including some ‘_’-s in ‘case’
     patterns.

   - bpo-44026(9): Include interpreter’s typo fix suggestions in message
     line for NameErrors and AttributeErrors.  Patch by E. Paine.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=45296

   (2) https://bugs.python.org/issue?@action=redirect&bpo=45193

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40128

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33962

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40468

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41611

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41611

   (8) https://bugs.python.org/issue?@action=redirect&bpo=44010

   (9) https://bugs.python.org/issue?@action=redirect&bpo=44026


File: python.info,  Node: Tools/Demos<27>,  Next: C API<37>,  Prev: IDLE<19>,  Up: Python 3 11 0 alpha 1

1.24.41.28 Tools/Demos
......................

   - bpo-44786(1): Fix a warning in regular expression in the c-analyzer
     script.

   - bpo-44967(2): pydoc now returns a non-zero status code when a
     module cannot be found.

   - bpo-44978(3): Allow the Argument Clinic tool to handle
     ‘__complex__’ special methods.

   - bpo-43425(4): Removed the “test2to3” demo project that demonstrated
     using lib2to3 to support Python 2.x and Python 3.x from a single
     source in a distutils package.  Patch by Donghee Na

   - bpo-44074(5): Make patchcheck automatically detect the correct base
     branch name (previously it was hardcoded to “master”)

   - bpo-20291(6): Added support for variadic positional parameters in
     Argument Clinic.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44786

   (2) https://bugs.python.org/issue?@action=redirect&bpo=44967

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44978

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43425

   (5) https://bugs.python.org/issue?@action=redirect&bpo=44074

   (6) https://bugs.python.org/issue?@action=redirect&bpo=20291


File: python.info,  Node: C API<37>,  Prev: Tools/Demos<27>,  Up: Python 3 11 0 alpha 1

1.24.41.29 C API
................

   - bpo-41710(1): The PyThread_acquire_lock_timed() function now clamps
     the timeout if it is too large, rather than aborting the process.
     Patch by Victor Stinner.

   - bpo-44687(2): ‘BufferedReader.peek()’ no longer raises *note
     ValueError: 2ec. when the entire file has already been buffered.

   - bpo-45116(3): Add the *note Py_ALWAYS_INLINE: 1c53. macro to ask
     the compiler to always inline a static inline function.  The
     compiler can ignore it and decides to not inline the function.
     Patch by Victor Stinner.

   - bpo-45094(4): Add the *note Py_NO_INLINE: 17ea. macro to disable
     inlining on a function.  Patch by Victor Stinner.

   - bpo-45061(5): Add a deallocator to the *note bool: 3c3. type to
     detect refcount bugs in C extensions which call
     ‘Py_DECREF(Py_True);’ or ‘Py_DECREF(Py_False);’ by mistake.  Patch
     by Victor Stinner.

   - bpo-42035(6): Add a new *note PyType_GetQualName(): 95a. function
     to get type’s qualified name.

   - bpo-41103(7): Reverts removal of the old buffer protocol because
     they are part of stable ABI.

   - bpo-44751(8): Remove ‘crypt.h’ include from the public ‘Python.h’
     header.

   - bpo-42747(9): The ‘Py_TPFLAGS_HAVE_VERSION_TAG’ type flag now does
     nothing.  The ‘Py_TPFLAGS_HAVE_AM_SEND’ flag (which was added in
     3.10) is removed.  Both were unnecessary because it is not possible
     to have type objects with the relevant fields missing.

   - bpo-44530(10): Added the ‘co_qualname’ to the ‘PyCodeObject’
     structure to propagate the qualified name from the compiler to code
     objects.

     Patch by Gabriele N. Tornetta

   - bpo-44441(11): *note Py_RunMain(): bbe. now resets *note
     PyImport_Inittab: 1b03. to its initial value at exit.  It must be
     possible to call *note PyImport_AppendInittab(): 1b04. or *note
     PyImport_ExtendInittab(): 1b05. at each Python initialization.
     Patch by Victor Stinner.

   - bpo-39947(12): Remove 4 private trashcan C API functions which were
     only kept for the backward compatibility of the stable ABI with
     Python 3.8 and older, since the trashcan API was not usable with
     the limited C API on Python 3.8 and older.  The trashcan API was
     excluded from the limited C API in Python 3.9.

     Removed functions:

        * _PyTrash_deposit_object()

        * _PyTrash_destroy_chain()

        * _PyTrash_thread_deposit_object()

        * _PyTrash_thread_destroy_chain()

     The trashcan C API was never usable with the limited C API, since
     old trashcan macros accessed directly *note PyThreadState: 991.
     members like ‘_tstate->trash_delete_nesting’, whereas the *note
     PyThreadState: 991. structure is opaque in the limited C API.

     Exclude also the ‘PyTrash_UNWIND_LEVEL’ constant from the C API.

     Patch by Victor Stinner.

   - bpo-40939(13): Removed documentation for the removed ‘PyParser_*’ C
     API.

   - bpo-43795(14): The list in *note Contents of Limited API: 99e. now
     shows the public name *note PyFrameObject: 98d. rather than
     ‘_frame’.  The non-existing entry ‘_node’ no longer appears in the
     list.

   - bpo-44378(15): *note Py_IS_TYPE(): 1b88. no longer uses *note
     Py_TYPE(): 3c9. to avoid a compiler warning: no longer cast ‘const
     PyObject*’ to ‘PyObject*’.  Patch by Victor Stinner.

   - bpo-39573(16): Convert the *note Py_TYPE(): 3c9. and *note
     Py_SIZE(): 986. macros to static inline functions.  The *note
     Py_SET_TYPE(): 985. and *note Py_SET_SIZE(): 987. functions must
     now be used to set an object type and size.  Patch by Victor
     Stinner.

   - bpo-44263(17): The *note PyType_Ready(): 981. function now raises
     an error if a type is defined with the *note Py_TPFLAGS_HAVE_GC:
     982. flag set but has no traverse function (*note
     PyTypeObject.tp_traverse: 983.).  Patch by Victor Stinner.

   - bpo-43795(18): The undocumented function ‘Py_FrozenMain()’ is
     removed from the Limited API.

   - bpo-44113(19): Deprecate the following functions to configure the
     Python initialization:

        * ‘PySys_AddWarnOptionUnicode()’

        * ‘PySys_AddWarnOption()’

        * ‘PySys_AddXOption()’

        * ‘PySys_HasWarnOptions()’

        * ‘Py_SetPath()’

        * ‘Py_SetProgramName()’

        * ‘Py_SetPythonHome()’

        * ‘Py_SetStandardStreamEncoding()’

        * ‘_Py_SetProgramFullPath()’

     Use the new *note PyConfig: 3f7. API of the *note Python
     Initialization Configuration: 646. instead ( PEP 587(20)).

   - bpo-44094(21): Remove ‘PyErr_SetFromErrnoWithUnicodeFilename()’,
     ‘PyErr_SetFromWindowsErrWithUnicodeFilename()’, and
     ‘PyErr_SetExcFromWindowsErrWithUnicodeFilename()’.  They are not
     documented and have been deprecated since Python 3.3.

   - bpo-43795(22): *note PyCodec_Unregister(): a99. is now properly
     exported as a function in the Windows Stable ABI DLL.

   - bpo-44029(23): Remove deprecated ‘Py_UNICODE’ APIs:
     ‘PyUnicode_Encode’, ‘PyUnicode_EncodeUTF7’, ‘PyUnicode_EncodeUTF8’,
     ‘PyUnicode_EncodeUTF16’, ‘PyUnicode_EncodeUTF32’,
     ‘PyUnicode_EncodeLatin1’, ‘PyUnicode_EncodeMBCS’,
     ‘PyUnicode_EncodeDecimal’, ‘PyUnicode_EncodeRawUnicodeEscape’,
     ‘PyUnicode_EncodeCharmap’, ‘PyUnicode_EncodeUnicodeEscape’,
     ‘PyUnicode_TransformDecimalToASCII’, ‘PyUnicode_TranslateCharmap’,
     ‘PyUnicodeEncodeError_Create’, ‘PyUnicodeTranslateError_Create’.
     See PEP 393(24) and PEP 624(25) for reference.

   - bpo-42035(26): Add a new *note PyType_GetName(): 959. function to
     get type’s short name.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41710

   (2) https://bugs.python.org/issue?@action=redirect&bpo=44687

   (3) https://bugs.python.org/issue?@action=redirect&bpo=45116

   (4) https://bugs.python.org/issue?@action=redirect&bpo=45094

   (5) https://bugs.python.org/issue?@action=redirect&bpo=45061

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42035

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41103

   (8) https://bugs.python.org/issue?@action=redirect&bpo=44751

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42747

   (10) https://bugs.python.org/issue?@action=redirect&bpo=44530

   (11) https://bugs.python.org/issue?@action=redirect&bpo=44441

   (12) https://bugs.python.org/issue?@action=redirect&bpo=39947

   (13) https://bugs.python.org/issue?@action=redirect&bpo=40939

   (14) https://bugs.python.org/issue?@action=redirect&bpo=43795

   (15) https://bugs.python.org/issue?@action=redirect&bpo=44378

   (16) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (17) https://bugs.python.org/issue?@action=redirect&bpo=44263

   (18) https://bugs.python.org/issue?@action=redirect&bpo=43795

   (19) https://bugs.python.org/issue?@action=redirect&bpo=44113

   (20) https://peps.python.org/pep-0587/

   (21) https://bugs.python.org/issue?@action=redirect&bpo=44094

   (22) https://bugs.python.org/issue?@action=redirect&bpo=43795

   (23) https://bugs.python.org/issue?@action=redirect&bpo=44029

   (24) https://peps.python.org/pep-0393/

   (25) https://peps.python.org/pep-0624/

   (26) https://bugs.python.org/issue?@action=redirect&bpo=42035


File: python.info,  Node: Python 3 10 0 beta 1,  Next: Python 3 10 0 alpha 7,  Prev: Python 3 11 0 alpha 1,  Up: Changelog

1.24.42 Python 3.10.0 beta 1
----------------------------

'Release date: 2021-05-03'

* Menu:

* Security: Security<30>.
* Core and Builtins: Core and Builtins<113>.
* Library: Library<116>.
* Core and Builtins: Core and Builtins<114>.
* Library: Library<117>.
* Core and Builtins: Core and Builtins<115>.
* Library: Library<118>.
* Documentation: Documentation<36>.
* Tests: Tests<36>.
* Build: Build<43>.
* Windows: Windows<37>.
* macOS: macOS<27>.
* IDLE: IDLE<20>.
* C API: C API<38>.


File: python.info,  Node: Security<30>,  Next: Core and Builtins<113>,  Up: Python 3 10 0 beta 1

1.24.42.1 Security
..................

   - bpo-43434(1): Creating *note sqlite3.Connection: 54e. objects now
     also produces ‘sqlite3.connect’ and ‘sqlite3.connect/handle’ *note
     auditing events: 1c56.  Previously these events were only produced
     by *note sqlite3.connect(): 5a6. calls.  Patch by Erlend E.
     Aasland.

   - bpo-43998(2): The *note ssl: d5. module sets more secure cipher
     suites defaults.  Ciphers without forward secrecy and with SHA-1
     MAC are disabled by default.  Security level 2 prohibits weak RSA,
     DH, and ECC keys with less than 112 bits of security.  *note
     SSLContext: 357. defaults to minimum protocol version TLS 1.2.
     Settings are based on Hynek Schlawack’s research.

   - bpo-43882(3): The presence of newline or tab characters in parts of
     a URL could allow some forms of attacks.

     Following the controlling specification for URLs defined by WHATWG
     *note urllib.parse(): 110. now removes ASCII newlines and tabs from
     URLs, preventing such attacks.

   - bpo-43472(4): Ensures interpreter-level audit hooks receive the
     ‘cpython.PyInterpreterState_New’ event when called through the
     ‘_xxsubinterpreters’ module.

   - bpo-43362(5): Fix invalid free in _sha3 module.  The issue was
     introduced in 3.10.0a1.  Python 3.9 and earlier are not affected.

   - bpo-43762(6): Add audit events for ‘sqlite3.connect/handle()’,
     *note sqlite3.Connection.enable_load_extension(): a41, and *note
     sqlite3.Connection.load_extension(): 6e0.  Patch by Erlend E.
     Aasland.

   - bpo-43756(7): Add new audit event ‘glob.glob/2’ to incorporate the
     new 'root_dir' and 'dir_fd' arguments added to *note glob.glob():
     5a0. and *note glob.iglob(): a0a.

   - bpo-36384(8): *note ipaddress: 84. module no longer accepts any
     leading zeros in IPv4 address strings.  Leading zeros are ambiguous
     and interpreted as octal notation by some libraries.  For example
     the legacy function *note socket.inet_aton(): b5c. treats leading
     zeros as octal notation.  glibc implementation of modern *note
     inet_pton(): b5d. does not accept any leading zeros.  For a while
     the *note ipaddress: 84. module used to accept ambiguous leading
     zeros.

   - bpo-43075(9): Fix Regular Expression Denial of Service (ReDoS)
     vulnerability in *note urllib.request.AbstractBasicAuthHandler:
     1c57.  The ReDoS-vulnerable regex has quadratic worst-case
     complexity and it allows cause a denial of service when identifying
     crafted invalid RFCs.  This ReDoS issue is on the client side and
     needs remote attackers to control the HTTP server.

   - bpo-42800(10): Audit hooks are now fired for frame.f_code,
     traceback.tb_frame, and generator code/frame attribute access.

   - bpo-37363(11): Add audit events to the *note http.client: 73.
     module.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43434

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43998

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43882

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43472

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43362

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43762

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43756

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36384

   (9) https://bugs.python.org/issue?@action=redirect&bpo=43075

   (10) https://bugs.python.org/issue?@action=redirect&bpo=42800

   (11) https://bugs.python.org/issue?@action=redirect&bpo=37363


File: python.info,  Node: Core and Builtins<113>,  Next: Library<116>,  Prev: Security<30>,  Up: Python 3 10 0 beta 1

1.24.42.2 Core and Builtins
...........................

   - bpo-43977(1): Prevent classes being both a sequence and a mapping
     when pattern matching.

   - bpo-43977(2): Use *note tp_flags: 1c59. on the class object to
     determine if the subject is a sequence or mapping when pattern
     matching.  Avoids the need to import *note collections.abc: 1f.
     when pattern matching.

   - bpo-43892(3): Restore proper validation of complex literal value
     patterns when parsing ‘match’ blocks.

   - bpo-43933(4): Set frame.f_lineno to the line number of the “with”
     kweyword when executing the call to ‘__exit__’.

   - bpo-43933(5): If the current position in a frame has no line number
     then set the f_lineno attribute to None, instead of -1, to conform
     to PEP 626.  This should not normally be possible, but might occur
     in some unusual circumstances.

   - bpo-43963(6): Importing the ‘_signal’ module in a subinterpreter
     has no longer side effects.

   - bpo-42739(7): The internal representation of line number tables is
     changed to not use sentinels, and an explicit length parameter is
     added to the out of process API function
     ‘PyLineTable_InitAddressRange’.  This makes the handling of line
     number tables more robust in some circumstances.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43977

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43977

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43892

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43933

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43933

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43963

   (7) https://bugs.python.org/issue?@action=redirect&bpo=42739


File: python.info,  Node: Library<116>,  Next: Core and Builtins<114>,  Prev: Core and Builtins<113>,  Up: Python 3 10 0 beta 1

1.24.42.3 Library
.................

   - bpo-43908(1): Make *note re: be. types immutable.  Patch by Erlend
     E. Aasland.

   - bpo-43908(2): Make the *note array.array: 4bf. type immutable.
     Patch by Erlend E. Aasland.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43908

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43908


File: python.info,  Node: Core and Builtins<114>,  Next: Library<117>,  Prev: Library<116>,  Up: Python 3 10 0 beta 1

1.24.42.4 Core and Builtins
...........................

   - bpo-43901(1): Change class and module objects to lazy-create empty
     annotations dicts on demand.  The annotations dicts are stored in
     the object’s __dict__ for backwards compatibility.

   - bpo-43892(2): Match patterns now use new dedicated AST nodes
     (‘MatchValue’, ‘MatchSingleton’, ‘MatchSequence’, ‘MatchStar’,
     ‘MatchMapping’, ‘MatchClass’) rather than reusing expression AST
     nodes.  ‘MatchAs’ and ‘MatchOr’ are now defined as pattern nodes
     rather than as expression nodes.  Patch by Nick Coghlan.

   - bpo-42725(3): Usage of ‘await’/‘yield’/‘yield from’ and named
     expressions within an annotation is now forbidden when PEP 563 is
     activated.

   - bpo-43754(4): When performing structural pattern matching ( PEP
     634(5)), captured names are now left unbound until the 'entire'
     pattern has matched successfully.

   - bpo-42737(6): Annotations for complex targets (everything beside
     simple names) no longer cause any runtime effects with ‘from
     __future__ import annotations’.

   - bpo-43914(7): *note SyntaxError: 18e. exceptions raised by the
     interpreter will highlight the full error range of the expression
     that constitutes the syntax error itself, instead of just where the
     problem is detected.  Patch by Pablo Galindo.

   - bpo-38605(8): Revert making ‘from __future__ import annotations’
     the default.  This follows the Steering Council decision to
     postpone PEP 563 changes to at least Python 3.11.  See the original
     email for more information regarding the decision:
     ‘https://mail.python.org/archives/list/python-dev@python.org/thread/CLVXXPQ2T2LQ5MP2Y53VVQFCXYWQJHKZ/’.
     Patch by Pablo Galindo.

   - bpo-43475(9): Hashes of NaN values now depend on object identity.
     Formerly, they always hashed to 0 even though NaN values are not
     equal to one another.  Having the same hash for unequal values
     caused pile-ups in hash tables.

   - bpo-43859(10): Improve the error message for *note
     IndentationError: 9ad. exceptions.  Patch by Pablo Galindo

   - bpo-41323(11): Constant tuple folding in bytecode optimizer now
     reuses tuple in constant table.

   - bpo-43846(12): Data stack usage is much reduced for large literal
     and call expressions.

   - bpo-38530(13): When printing *note NameError: 452. raised by the
     interpreter, ‘PyErr_Display()’ will offer suggestions of similar
     variable names in the function that the exception was raised from.
     Patch by Pablo Galindo

   - bpo-43823(14): Improve syntax errors for invalid dictionary
     literals.  Patch by Pablo Galindo.

   - bpo-43822(15): Improve syntax errors in the parser for missing
     commas between expressions.  Patch by Pablo Galindo.

   - bpo-43798(16): *note ast.alias: 1c5c. nodes now include source
     location metadata attributes e.g.  lineno, col_offset.

   - bpo-43797(17): Improve ‘SyntaxError’ error messages for invalid
     comparisons.  Patch by Pablo Galindo.

   - bpo-43760(18): Move the flag for checking whether tracing is
     enabled to the C stack, from the heap.  Should speed up dispatch in
     the interpreter.

   - bpo-43682(19): Static methods (*note @staticmethod: 453.) and class
     methods (*note @classmethod: 48f.) now inherit the method
     attributes (‘__module__’, ‘__name__’, ‘__qualname__’, ‘__doc__’,
     ‘__annotations__’) and have a new ‘__wrapped__’ attribute.  Patch
     by Victor Stinner.

   - bpo-43751(20): Fixed a bug where ‘anext(ait, default)’ would
     erroneously return None.

   - bpo-42128(21): *note __match_args__: 1c5d. is no longer allowed to
     be a list.

   - bpo-43683(22): Add GEN_START opcode.  Marks start of generator,
     including async, or coroutine and handles sending values to a newly
     created generator or coroutine.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43901

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43892

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42725

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43754

   (5) https://peps.python.org/pep-0634/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42737

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43914

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38605

   (9) https://bugs.python.org/issue?@action=redirect&bpo=43475

   (10) https://bugs.python.org/issue?@action=redirect&bpo=43859

   (11) https://bugs.python.org/issue?@action=redirect&bpo=41323

   (12) https://bugs.python.org/issue?@action=redirect&bpo=43846

   (13) https://bugs.python.org/issue?@action=redirect&bpo=38530

   (14) https://bugs.python.org/issue?@action=redirect&bpo=43823

   (15) https://bugs.python.org/issue?@action=redirect&bpo=43822

   (16) https://bugs.python.org/issue?@action=redirect&bpo=43798

   (17) https://bugs.python.org/issue?@action=redirect&bpo=43797

   (18) https://bugs.python.org/issue?@action=redirect&bpo=43760

   (19) https://bugs.python.org/issue?@action=redirect&bpo=43682

   (20) https://bugs.python.org/issue?@action=redirect&bpo=43751

   (21) https://bugs.python.org/issue?@action=redirect&bpo=42128

   (22) https://bugs.python.org/issue?@action=redirect&bpo=43683


File: python.info,  Node: Library<117>,  Next: Core and Builtins<115>,  Prev: Core and Builtins<114>,  Up: Python 3 10 0 beta 1

1.24.42.5 Library
.................

   - bpo-43105(1): Importlib now resolves relative paths when creating
     module spec objects from file locations.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43105


File: python.info,  Node: Core and Builtins<115>,  Next: Library<118>,  Prev: Library<117>,  Up: Python 3 10 0 beta 1

1.24.42.6 Core and Builtins
...........................

   - bpo-43682(1): Static methods (*note @staticmethod: 453.) are now
     callable as regular functions.  Patch by Victor Stinner.

   - bpo-42609(2): Prevented crashes in the AST validator and optimizer
     when compiling some absurdly long expressions like ‘"+0"*1000000’.
     *note RecursionError: f6a. is now raised instead.

   - bpo-38530(3): When printing *note AttributeError: 5f0,
     ‘PyErr_Display()’ will offer suggestions of similar attribute names
     in the object that the exception was raised from.  Patch by Pablo
     Galindo

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43682

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42609

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38530


File: python.info,  Node: Library<118>,  Next: Documentation<36>,  Prev: Core and Builtins<115>,  Up: Python 3 10 0 beta 1

1.24.42.7 Library
.................

   - bpo-44015(1): In @dataclass(), raise a TypeError if KW_ONLY is
     specified more than once.

   - bpo-25478(2): Added a 'total()' method to collections.Counter() to
     compute the sum of the counts.

   - bpo-43733(3): Change *note netrc.netrc: 1c61. to use UTF-8 encoding
     before using locale encoding.

   - bpo-43979(4): Removed an unnecessary list comprehension before
     looping from *note urllib.parse.parse_qsl(): 31e.  Patch by
     Christoph Zwerschke and Donghee Na.

   - bpo-43993(5): Update bundled pip to 21.1.1.

   - bpo-43957(6): [Enum] Deprecate ‘TypeError’ when non-member is used
     in a containment check; In 3.12 ‘True’ or ‘False’ will be returned
     instead, and containment will return ‘True’ if the value is either
     a member of that enum or one of its members” value.

   - bpo-42904(7): For backwards compatibility with previous minor
     versions of Python, if *note typing.get_type_hints(): 8c1. receives
     no namespace dictionary arguments, *note typing.get_type_hints():
     8c1. will search through the global then local namespaces during
     evaluation of stringized type annotations (string forward
     references) inside a class.

   - bpo-43945(8): [Enum] Deprecate non-standard mixin format()
     behavior: in 3.12 the enum member, not the member’s value, will be
     used for format() calls.

   - bpo-41139(9): Deprecate undocumented ‘cgi.log()’ API.

   - bpo-43937(10): Fixed the *note turtle: 107. module working with
     non-default root window.

   - bpo-43930(11): Update bundled pip to 21.1 and setuptools to 56.0.0

   - bpo-43907(12): Fix a bug in the pure-Python pickle implementation
     when using protocol 5, where bytearray instances that occur several
     time in the pickled object graph would incorrectly unpickle into
     repeated copies of the bytearray object.

   - bpo-43926(13): In ‘importlib.metadata’, provide a uniform interface
     to ‘Description’, allow for any field to be encoded with multiline
     values, remove continuation lines from multiline values, and add a
     ‘.json’ property for easy access to the PEP 566 JSON-compatible
     form.  Sync with ‘importlib_metadata 4.0’.

   - bpo-43920(14): OpenSSL 3.0.0: *note load_verify_locations(): 10f0.
     now returns a consistent error message when cadata contains no
     valid certificate.

   - bpo-43607(15): *note urllib: 10e. can now convert Windows paths
     with ‘\\?\’ prefixes into URL paths.

   - bpo-43817(16): Add *note inspect.get_annotations(): a16, which
     safely computes the annotations defined on an object.  It works
     around the quirks of accessing the annotations from various types
     of objects, and makes very few assumptions about the object passed
     in.  *note inspect.get_annotations(): a16. can also correctly
     un-stringize stringized annotations.

     *note inspect.signature(): 22f, ‘inspect.from_callable()’, and
     ‘inspect.from_function()’ now call *note inspect.get_annotations():
     a16. to retrieve annotations.  This means *note
     inspect.signature(): 22f. and ‘inspect.from_callable()’ can now
     un-stringize stringized annotations, too.

   - bpo-43284(17): platform.win32_ver derives the windows version from
     sys.getwindowsversion().platform_version which in turn derives the
     version from kernel32.dll (which can be of a different version than
     Windows itself).  Therefore change the platform.win32_ver to
     determine the version using the platform module’s _syscmd_ver
     private function to return an accurate version.

   - bpo-42854(18): The *note ssl: d5. module now uses ‘SSL_read_ex’ and
     ‘SSL_write_ex’ internally.  The functions support reading and
     writing of data larger than 2 GB. Writing zero-length data no
     longer fails with a protocol violation error.

   - bpo-42333(19): Port ‘_ssl’ extension module to multiphase
     initialization.

   - bpo-43880(20): *note ssl: d5. now raises DeprecationWarning for
     OP_NO_SSL/TLS* options, old TLS versions, old protocols, and other
     features that have been deprecated since Python 3.6, 3.7, or
     OpenSSL 1.1.0.

   - bpo-41559(21): PEP 612(22) is now implemented purely in Python;
     builtin ‘types.GenericAlias’ objects no longer include
     ‘typing.ParamSpec’ in ‘__parameters__’ (with the exception of
     ‘collections.abc.Callable’“s ‘GenericAlias’).  This means
     previously invalid uses of ‘ParamSpec’ (such as ‘list[P]’) which
     worked in earlier versions of Python 3.10 alpha, will now raise
     ‘TypeError’ during substitution.

   - bpo-43867(23): The *note multiprocessing: 98. ‘Server’ class now
     explicitly catches *note SystemExit: f3e. and closes the client
     connection in this case.  It happens when the
     ‘Server.serve_client()’ method reaches the end of file (EOF).

   - bpo-40443(24): Remove unused imports: pyclbr no longer uses copy,
     and typing no longer uses ast.  Patch by Victor Stinner.

   - bpo-43820(25): Remove an unneeded copy of the namespace passed to
     dataclasses.make_dataclass().

   - bpo-43787(26): Add ‘__iter__()’ method to *note bz2.BZ2File: a68,
     *note gzip.GzipFile: 65c, and *note lzma.LZMAFile: 120e.  It makes
     iterating them about 2x faster.  Patch by Inada Naoki.

   - bpo-43680(27): Deprecate io.OpenWrapper and _pyio.OpenWrapper: use
     io.open and _pyio.open instead.  Until Python 3.9, _pyio.open was
     not a static method and builtins.open was set to OpenWrapper to not
     become a bound method when set to a class variable.  _io.open is a
     built-in function whereas _pyio.open is a Python function.  In
     Python 3.10, _pyio.open() is now a static method, and
     builtins.open() is now io.open().

   - bpo-43680(28): The Python ‘_pyio.open()’ function becomes a static
     method to behave as *note io.open(): 741. built-in function: don’t
     become a bound method when stored as a class variable.  It becomes
     possible since static methods are now callable in Python 3.10.
     Moreover, ‘_pyio.OpenWrapper()’ becomes a simple alias to
     ‘_pyio.open()’.  Patch by Victor Stinner.

   - bpo-41515(29): Fix *note KeyError: 5e7. raised in *note
     typing.get_type_hints(): 8c1. due to synthetic modules that don’t
     appear in ‘sys.modules’.

   - bpo-43776(30): When *note subprocess.Popen: 4b8. args are provided
     as a string or as *note pathlib.Path: 266, the Popen instance repr
     now shows the right thing.

   - bpo-42248(31): [Enum] ensure exceptions raised in ‘_missing__’ are
     released

   - bpo-43744(32): fix issue with enum member name matching the start
     of a private variable name

   - bpo-43772(33): Fixed the return value of ‘TypeVar.__ror__’.  Patch
     by Jelle Zijlstra.

   - bpo-43764(34): Add match_args parameter to @dataclass decorator to
     allow suppression of __match_args__ generation.

   - bpo-43799(35): OpenSSL 3.0.0: define ‘OPENSSL_API_COMPAT’ 1.1.1 to
     suppress deprecation warnings.  Python requires OpenSSL 1.1.1 APIs.

   - bpo-43478(36): Mocks can no longer be used as the specs for other
     Mocks.  As a result, an already-mocked object cannot have an
     attribute mocked using ‘autospec=True’ or be the subject of a
     ‘create_autospec(...)’ call.  This can uncover bugs in tests since
     these Mock-derived Mocks will always pass certain tests (e.g.
     *note isinstance(): 2ad.) and builtin assert functions (e.g.
     assert_called_once_with) will unconditionally pass.

   - bpo-43794(37): Add *note ssl.OP_IGNORE_UNEXPECTED_EOF: a3a.
     constants (OpenSSL 3.0.0)

   - bpo-43785(38): Improve ‘bz2.BZ2File’ performance by removing the
     RLock from BZ2File.  This makes BZ2File thread unsafe in the face
     of multiple simultaneous readers or writers, just like its
     equivalent classes in *note gzip: 6b. and *note lzma: 8e. have
     always been.  Patch by Inada Naoki.

   - bpo-43789(39): OpenSSL 3.0.0: Don’t call the password callback
     function a second time when first call has signaled an error
     condition.

   - bpo-43788(40): The header files for *note ssl: d5. error codes are
     now OpenSSL version-specific.  Exceptions will now show correct
     reason and library codes.  The ‘make_ssl_data.py’ script has been
     rewritten to use OpenSSL’s text file with error codes.

   - bpo-43766(41): Implement PEP 647(42) in the *note typing: 10a.
     module by adding ‘TypeGuard’.

   - bpo-25264(43): *note os.path.realpath(): 262. now accepts a
     'strict' keyword-only argument.  When set to ‘True’, *note OSError:
     2c0. is raised if a path doesn’t exist or a symlink loop is
     encountered.

   - bpo-43780(44): In ‘importlib.metadata’, incorporate changes from
     importlib_metadata 3.10: Add mtime-based caching during
     distribution discovery.  Flagged use of dict result from
     ‘entry_points()’ as deprecated.

   - gh-47383(45): The ‘P.args’ and ‘P.kwargs’ attributes of *note
     typing.ParamSpec: 488. are now instances of the new classes *note
     typing.ParamSpecArgs: 9cb. and *note typing.ParamSpecKwargs: 9cc,
     which enables a more useful ‘repr()’.  Patch by Jelle Zijlstra.

   - bpo-43731(46): Add an ‘encoding’ parameter ‘logging.fileConfig()’.

   - bpo-43712(47): Add ‘encoding’ and ‘errors’ parameters to *note
     fileinput.input(): a02. and *note fileinput.FileInput: 941.

   - bpo-38659(48): A ‘simple_enum’ decorator is added to the ‘enum’
     module to convert a normal class into an Enum.  ‘test_simple_enum’
     added to test simple enums against a corresponding normal Enum.
     Standard library modules updated to use ‘simple_enum’.

   - bpo-43764(49): Fix an issue where *note __match_args__: 1c5d.
     generation could fail for some *note dataclasses: 33.

   - bpo-43752(50): Fix *note sqlite3: d4. regression for zero-sized
     blobs with converters, where ‘b""’ was returned instead of ‘None’.
     The regression was introduced by PR 24723.  Patch by Erlend E.
     Aasland.

   - bpo-43655(51): *note tkinter: f6. dialog windows are now recognized
     as dialogs by window managers on macOS and X Window.

   - bpo-43723(52): The following ‘threading’ methods are now deprecated
     and should be replaced:

        - ‘currentThread’ => *note threading.current_thread(): 35e.

        - ‘activeCount’ => *note threading.active_count(): 35f.

        - ‘Condition.notifyAll’ => *note
          threading.Condition.notify_all(): 359.

        - ‘Event.isSet’ => *note threading.Event.is_set(): 35a.

        - ‘Thread.setName’ => *note threading.Thread.name: 2a0.

        - ‘thread.getName’ => *note threading.Thread.name: 2a0.

        - ‘Thread.isDaemon’ => *note threading.Thread.daemon: 35c.

        - ‘Thread.setDaemon’ => *note threading.Thread.daemon: 35c.

     Patch by Jelle Zijlstra.

   - bpo-2135(53): Deprecate find_module() and find_loader()
     implementations in importlib and zipimport.

   - bpo-43534(54): *note turtle.textinput(): 1c62. and *note
     turtle.numinput(): 1c63. create now a transient window working on
     behalf of the canvas window.

   - bpo-43532(55): Add the ability to specify keyword-only fields to
     dataclasses.  These fields will become keyword-only arguments to
     the generated __init__.

   - bpo-43522(56): Fix problem with *note hostname_checks_common_name:
     d78.  OpenSSL does not copy hostflags from 'struct SSL_CTX' to
     'struct SSL'.

   - bpo-8978(57): Improve error message for *note tarfile.open(): 1079.
     when *note lzma: 8e. / *note bz2: 14. are unavailable.  Patch by
     Anthony Sottile.

   - bpo-42967(58): Allow *note bytes: 192. ‘separator’ argument in
     ‘urllib.parse.parse_qs’ and ‘urllib.parse.parse_qsl’ when parsing
     *note str: 169. query strings.  Previously, this raised a
     ‘TypeError’.

   - bpo-43296(59): Improve *note sqlite3: d4. error handling:
     ‘sqlite3_value_blob()’ errors that set ‘SQLITE_NOMEM’ now raise
     *note MemoryError: 1786.  Patch by Erlend E. Aasland.

   - bpo-43312(60): New functions *note
     sysconfig.get_preferred_scheme(): 8a0. and *note
     sysconfig.get_default_scheme(): 1b9d. are added to query a platform
     for its preferred «user», «home», and «prefix» (default) scheme
     names.

   - bpo-43265(61): Improve *note sqlite3.Connection.backup(): d75.
     error handling.  The error message for non-existent target database
     names is now ‘unknown database <database name>’ instead of ‘SQL
     logic error’.  Patch by Erlend E. Aasland.

   - bpo-41282(62): Install schemes in ‘distutils.command.install’ are
     now loaded from *note sysconfig: e1.

   - bpo-41282(63): ‘distutils.sysconfig’ has been merged to *note
     sysconfig: e1.

   - bpo-43176(64): Fixed processing of a dataclass that inherits from a
     frozen dataclass with no fields.  It is now correctly detected as
     an error.

   - bpo-43080(65): *note pprint: b3. now has support for *note
     dataclasses.dataclass: 4e2.  Patch by Lewis Gaul.

   - bpo-39950(66): Add ‘pathlib.Path.hardlink_to()’ method that
     supersedes ‘link_to()’.  The new method has the same argument order
     as ‘symlink_to()’.

   - bpo-42904(67): *note typing.get_type_hints(): 8c1. now checks the
     local namespace of a class when evaluating PEP 563(68) annotations
     inside said class.

   - bpo-42269(69): Add ‘slots’ parameter to ‘dataclasses.dataclass’
     decorator to automatically generate ‘__slots__’ for class.  Patch
     provided by Yurii Karabas.

   - bpo-39529(70): Deprecated use of *note asyncio.get_event_loop():
     2f2. without running event loop.  Emit deprecation warning for
     *note asyncio: b. functions which implicitly create a *note Future:
     dc8. or *note Task: 1c7. objects if there is no running event loop
     and no explicit 'loop' argument is passed: *note ensure_future():
     e73, *note wrap_future(): 1c64, *note gather(): 814, *note
     shield(): c67, *note as_completed(): 4c7. and constructors of *note
     Future: dc8, *note Task: 1c7, *note StreamReader: 1c65,
     ‘StreamReaderProtocol’.

   - bpo-18369(71): Certificate and PrivateKey classes were added to the
     ssl module.  Certificates and keys can now be loaded from memory
     buffer, too.

   - bpo-41486(72): Use a new output buffer management code for *note
     bz2: 14. / *note lzma: 8e. / *note zlib: 139. modules, and add
     ‘.readall()’ function to ‘_compression.DecompressReader’ class.
     These bring some performance improvements.  Patch by Ma Lin.

   - bpo-31870(73): The *note ssl.get_server_certificate(): a3f.
     function now has a 'timeout' parameter.

   - bpo-41735(74): Fix thread locks in zlib module may go wrong in rare
     case.  Patch by Ma Lin.

   - bpo-36470(75): Fix dataclasses with ‘InitVar’s and *note replace():
     1a52.  Patch by Claudiu Popa.

   - bpo-40849(76): Expose X509_V_FLAG_PARTIAL_CHAIN ssl flag

   - bpo-35114(77): *note ssl.RAND_status(): 1c66. now returns a boolean
     value (as documented) instead of ‘1’ or ‘0’.

   - bpo-39906(78): *note pathlib.Path.stat(): a26. and *note chmod():
     a27. now accept a 'follow_symlinks' keyword-only argument for
     consistency with corresponding functions in the *note os: a5.
     module.

   - bpo-39899(79): *note os.path.expanduser(): c0b. now refuses to
     guess Windows home directories if the basename of current user’s
     home directory does not match their username.

     *note pathlib.Path.expanduser(): 1044. and *note home(): 1045. now
     consistently raise *note RuntimeError: 244. exception when a home
     directory cannot be resolved.  Previously a *note KeyError: 5e7.
     exception could be raised on Windows when the ‘"USERNAME"’
     environment variable was unset.

   - bpo-36076(80): Added SNI support to *note
     ssl.get_server_certificate(): a3f.

   - bpo-38490(81): Covariance, Pearson’s correlation, and simple linear
     regression functionality was added to statistics module.  Patch by
     Tymoteusz Wołodźko.

   - bpo-33731(82): Provide a locale.localize() function, which converts
     a normalized number string into a locale format.

   - bpo-32745(83): Fix a regression in the handling of ctypes” *note
     ctypes.c_wchar_p: 1a40. type: embedded null characters would cause
     a *note ValueError: 2ec. to be raised.  Patch by Zackery Spytz.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=44015

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25478

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43733

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43979

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43993

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43957

   (7) https://bugs.python.org/issue?@action=redirect&bpo=42904

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43945

   (9) https://bugs.python.org/issue?@action=redirect&bpo=41139

   (10) https://bugs.python.org/issue?@action=redirect&bpo=43937

   (11) https://bugs.python.org/issue?@action=redirect&bpo=43930

   (12) https://bugs.python.org/issue?@action=redirect&bpo=43907

   (13) https://bugs.python.org/issue?@action=redirect&bpo=43926

   (14) https://bugs.python.org/issue?@action=redirect&bpo=43920

   (15) https://bugs.python.org/issue?@action=redirect&bpo=43607

   (16) https://bugs.python.org/issue?@action=redirect&bpo=43817

   (17) https://bugs.python.org/issue?@action=redirect&bpo=43284

   (18) https://bugs.python.org/issue?@action=redirect&bpo=42854

   (19) https://bugs.python.org/issue?@action=redirect&bpo=42333

   (20) https://bugs.python.org/issue?@action=redirect&bpo=43880

   (21) https://bugs.python.org/issue?@action=redirect&bpo=41559

   (22) https://peps.python.org/pep-0612/

   (23) https://bugs.python.org/issue?@action=redirect&bpo=43867

   (24) https://bugs.python.org/issue?@action=redirect&bpo=40443

   (25) https://bugs.python.org/issue?@action=redirect&bpo=43820

   (26) https://bugs.python.org/issue?@action=redirect&bpo=43787

   (27) https://bugs.python.org/issue?@action=redirect&bpo=43680

   (28) https://bugs.python.org/issue?@action=redirect&bpo=43680

   (29) https://bugs.python.org/issue?@action=redirect&bpo=41515

   (30) https://bugs.python.org/issue?@action=redirect&bpo=43776

   (31) https://bugs.python.org/issue?@action=redirect&bpo=42248

   (32) https://bugs.python.org/issue?@action=redirect&bpo=43744

   (33) https://bugs.python.org/issue?@action=redirect&bpo=43772

   (34) https://bugs.python.org/issue?@action=redirect&bpo=43764

   (35) https://bugs.python.org/issue?@action=redirect&bpo=43799

   (36) https://bugs.python.org/issue?@action=redirect&bpo=43478

   (37) https://bugs.python.org/issue?@action=redirect&bpo=43794

   (38) https://bugs.python.org/issue?@action=redirect&bpo=43785

   (39) https://bugs.python.org/issue?@action=redirect&bpo=43789

   (40) https://bugs.python.org/issue?@action=redirect&bpo=43788

   (41) https://bugs.python.org/issue?@action=redirect&bpo=43766

   (42) https://peps.python.org/pep-0647/

   (43) https://bugs.python.org/issue?@action=redirect&bpo=25264

   (44) https://bugs.python.org/issue?@action=redirect&bpo=43780

   (45) https://github.com/python/cpython/issues/47383

   (46) https://bugs.python.org/issue?@action=redirect&bpo=43731

   (47) https://bugs.python.org/issue?@action=redirect&bpo=43712

   (48) https://bugs.python.org/issue?@action=redirect&bpo=38659

   (49) https://bugs.python.org/issue?@action=redirect&bpo=43764

   (50) https://bugs.python.org/issue?@action=redirect&bpo=43752

   (51) https://bugs.python.org/issue?@action=redirect&bpo=43655

   (52) https://bugs.python.org/issue?@action=redirect&bpo=43723

   (53) https://bugs.python.org/issue?@action=redirect&bpo=2135

   (54) https://bugs.python.org/issue?@action=redirect&bpo=43534

   (55) https://bugs.python.org/issue?@action=redirect&bpo=43532

   (56) https://bugs.python.org/issue?@action=redirect&bpo=43522

   (57) https://bugs.python.org/issue?@action=redirect&bpo=8978

   (58) https://bugs.python.org/issue?@action=redirect&bpo=42967

   (59) https://bugs.python.org/issue?@action=redirect&bpo=43296

   (60) https://bugs.python.org/issue?@action=redirect&bpo=43312

   (61) https://bugs.python.org/issue?@action=redirect&bpo=43265

   (62) https://bugs.python.org/issue?@action=redirect&bpo=41282

   (63) https://bugs.python.org/issue?@action=redirect&bpo=41282

   (64) https://bugs.python.org/issue?@action=redirect&bpo=43176

   (65) https://bugs.python.org/issue?@action=redirect&bpo=43080

   (66) https://bugs.python.org/issue?@action=redirect&bpo=39950

   (67) https://bugs.python.org/issue?@action=redirect&bpo=42904

   (68) https://peps.python.org/pep-0563/

   (69) https://bugs.python.org/issue?@action=redirect&bpo=42269

   (70) https://bugs.python.org/issue?@action=redirect&bpo=39529

   (71) https://bugs.python.org/issue?@action=redirect&bpo=18369

   (72) https://bugs.python.org/issue?@action=redirect&bpo=41486

   (73) https://bugs.python.org/issue?@action=redirect&bpo=31870

   (74) https://bugs.python.org/issue?@action=redirect&bpo=41735

   (75) https://bugs.python.org/issue?@action=redirect&bpo=36470

   (76) https://bugs.python.org/issue?@action=redirect&bpo=40849

   (77) https://bugs.python.org/issue?@action=redirect&bpo=35114

   (78) https://bugs.python.org/issue?@action=redirect&bpo=39906

   (79) https://bugs.python.org/issue?@action=redirect&bpo=39899

   (80) https://bugs.python.org/issue?@action=redirect&bpo=36076

   (81) https://bugs.python.org/issue?@action=redirect&bpo=38490

   (82) https://bugs.python.org/issue?@action=redirect&bpo=33731

   (83) https://bugs.python.org/issue?@action=redirect&bpo=32745


File: python.info,  Node: Documentation<36>,  Next: Tests<36>,  Prev: Library<118>,  Up: Python 3 10 0 beta 1

1.24.42.8 Documentation
.......................

   - bpo-43987(1): Add «Annotations Best Practices» document as a new
     HOWTO.

   - bpo-43977(2): Document the new *note Py_TPFLAGS_MAPPING: 1c40. and
     *note Py_TPFLAGS_SEQUENCE: 1c41. type flags.

   - bpo-43959(3): The documentation on the PyContextVar C-API was
     clarified.

   - bpo-43938(4): Update dataclasses documentation to express that
     FrozenInstanceError is derived from AttributeError.

   - bpo-43778(5): Fix the Sphinx glossary_search extension: create the
     _static/ sub-directory if it doesn’t exist.

   - bpo-43755(6): Update documentation to reflect that unparenthesized
     lambda expressions can no longer be the expression part in an ‘if’
     clause in comprehensions and generator expressions since Python
     3.9.

   - bpo-43739(7): Fixing the example code in
     Doc/extending/extending.rst to declare and initialize the pmodule
     variable to be of the right type.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43987

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43977

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43959

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43938

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43778

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43755

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43739


File: python.info,  Node: Tests<36>,  Next: Build<43>,  Prev: Documentation<36>,  Up: Python 3 10 0 beta 1

1.24.42.9 Tests
...............

   - bpo-43961(1): Fix test_logging.test_namer_rotator_inheritance() on
     Windows: use *note os.replace(): 12fa. rather than *note
     os.rename(): 12f9.  Patch by Victor Stinner.

   - bpo-43842(2): Fix a race condition in the SMTP test of
     test_logging.  Don’t close a file descriptor (socket) from a
     different thread while asyncore.loop() is polling the file
     descriptor.  Patch by Victor Stinner.

   - bpo-43843(3): ‘test.libregrtest’ now marks a test as ENV_CHANGED
     (altered the execution environment) if a thread raises an exception
     but does not catch it.  It sets a hook on *note
     threading.excepthook(): a4d.  Use ‘--fail-env-changed’ option to
     mark the test as failed.  Patch by Victor Stinner.

   - bpo-43811(4): Tests multiple OpenSSL versions on GitHub Actions.
     Use ccache to speed up testing.

   - bpo-43791(5): OpenSSL 3.0.0: Disable testing of legacy protocols
     TLS 1.0 and 1.1.  Tests are failing with
     TLSV1_ALERT_INTERNAL_ERROR.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43961

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43842

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43843

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43811

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43791


File: python.info,  Node: Build<43>,  Next: Windows<37>,  Prev: Tests<36>,  Up: Python 3 10 0 beta 1

1.24.42.10 Build
................

   - bpo-43567(1): Improved generated code refresh
     (AST/tokens/opcodes/keywords) on Windows.

   - bpo-43669(2): Implement PEP 644(3).  Python now requires OpenSSL
     1.1.1 or newer.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43567

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43669

   (3) https://peps.python.org/pep-0644/


File: python.info,  Node: Windows<37>,  Next: macOS<27>,  Prev: Build<43>,  Up: Python 3 10 0 beta 1

1.24.42.11 Windows
..................

   - bpo-35306(1): Adds additional arguments to *note os.startfile():
     1c6b. function.

   - bpo-43538(2): Avoid raising errors from *note
     pathlib.Path.exists(): c0d. when passed an invalid filename.

   - bpo-38822(3): Fixed *note os.stat(): 26d. failing on inaccessible
     directories with a trailing slash, rather than falling back to the
     parent directory’s metadata.  This implicitly affected *note
     os.path.exists(): c05. and *note os.path.isdir(): c07.

   - bpo-26227(4): Fixed decoding of host names in *note
     socket.gethostbyaddr(): 1c6c. and *note socket.gethostbyname_ex():
     1c6d.

   - bpo-40432(5): Updated pegen regeneration script on Windows to find
     and use Python 3.8 or higher.  Prior to this, pegen regeneration
     already required 3.8 or higher, but the script may have used lower
     versions of Python.

   - bpo-43745(6): Actually updates Windows release to OpenSSL 1.1.1k.
     Earlier releases were mislabelled and actually included 1.1.1i
     again.

   - bpo-43652(7): Update Tcl and Tk to 8.6.11 in Windows installer.

   - bpo-43492(8): Upgrade Windows installer to use SQLite 3.35.5.

   - bpo-30555(9): Fix ‘WindowsConsoleIO’ errors in the presence of fd
     redirection.  Patch by Segev Finer.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35306

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43538

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38822

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26227

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40432

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43745

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43652

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43492

   (9) https://bugs.python.org/issue?@action=redirect&bpo=30555


File: python.info,  Node: macOS<27>,  Next: IDLE<20>,  Prev: Windows<37>,  Up: Python 3 10 0 beta 1

1.24.42.12 macOS
................

   - bpo-42119(1): Fix check for macOS SDK paths when building Python.
     Narrow search to match contents of SDKs, namely only files in
     ‘/System/Library’, ‘/System/IOSSupport’, and ‘/usr’ other than
     ‘/usr/local’.  Previously, anything under ‘/System’ was assumed to
     be in an SDK which causes problems with the new file system layout
     in 10.15+ where user file systems may appear to be mounted under
     ‘/System’.  Paths in ‘/Library’ were also incorrectly treated as
     SDK locations.

   - bpo-43568(2): Drop support for MACOSX_DEPLOYMENT_TARGET < 10.3

   - bpo-44009(3): Provide «python3.x-intel64» executable to allow
     reliably forcing macOS universal2 framework builds to run under
     Rosetta 2 Intel-64 emulation on Apple Silicon Macs.  This can be
     useful for testing or when universal2 wheels are not yet available.

   - bpo-43851(4): Build SQLite with ‘SQLITE_OMIT_AUTOINIT’ on macOS.
     Patch by Erlend E. Aasland.

   - bpo-43492(5): Update macOS installer to use SQLite 3.35.4.

   - bpo-42235(6): ‘Mac/BuildScript/build-installer.py’ will now use
     «–enable-optimizations» and ‘--with-lto’ when building on macOS
     10.15 or later.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42119

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43568

   (3) https://bugs.python.org/issue?@action=redirect&bpo=44009

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43851

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43492

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42235


File: python.info,  Node: IDLE<20>,  Next: C API<38>,  Prev: macOS<27>,  Up: Python 3 10 0 beta 1

1.24.42.13 IDLE
...............

   - bpo-37903(1): Add mouse actions to the shell sidebar.  Left click
     and optional drag selects one or more lines, as with the editor
     line number sidebar.  Right click after selecting raises a context
     menu with “copy with prompts”.  This zips together prompts from the
     sidebar with lines from the selected text.

   - bpo-43981(2): Fix reference leak in test_sidebar and test_squeezer.
     Patches by Terry Jan Reedy and Pablo Galindo

   - bpo-37892(3): Indent IDLE Shell input with spaces instead of tabs

   - bpo-43655(4): IDLE dialog windows are now recognized as dialogs by
     window managers on macOS and X Window.

   - bpo-37903(5): IDLE’s shell now shows prompts in a separate
     side-bar.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37903

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43981

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37892

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43655

   (5) https://bugs.python.org/issue?@action=redirect&bpo=37903


File: python.info,  Node: C API<38>,  Prev: IDLE<20>,  Up: Python 3 10 0 beta 1

1.24.42.14 C API
................

   - bpo-43916(1): Add a new *note Py_TPFLAGS_DISALLOW_INSTANTIATION:
     7a3. type flag to disallow creating type instances.  Patch by
     Victor Stinner.

   - bpo-43774(2): Remove the now unused ‘PYMALLOC_DEBUG’ macro.  Debug
     hooks on memory allocators are now installed by default if Python
     is built in debug mode (if ‘Py_DEBUG’ macro is defined).  Moreover,
     they can now be used on Python build in release mode (ex: using
     ‘PYTHONMALLOC=debug’ environment variable).

   - bpo-43962(3): _PyInterpreterState_IDIncref() now calls
     _PyInterpreterState_IDInitref() and always increments id_refcount.
     Previously, calling _xxsubinterpreters.get_current() could create
     an id_refcount inconsistency when a
     _xxsubinterpreters.InterpreterID object was deallocated.  Patch by
     Victor Stinner.

   - bpo-28254(4): Add new C-API functions to control the state of the
     garbage collector: *note PyGC_Enable(): aa6, *note PyGC_Disable():
     aa7, *note PyGC_IsEnabled(): aa8, corresponding to the functions in
     the *note gc: 64. module.

   - bpo-43908(5): Introduce *note Py_TPFLAGS_IMMUTABLETYPE: 3cf. flag
     for immutable type objects, and modify *note PyType_Ready(): 981.
     to set it for static types.  Patch by Erlend E. Aasland.

   - bpo-43795(6): *note PyMem_Calloc(): 10af. is now available in the
     limited C API (‘Py_LIMITED_API’).

   - bpo-43868(7): *note PyOS_ReadlineFunctionPointer(): 7a6. is no
     longer exported by limited C API headers and by ‘python3.dll’ on
     Windows.  Like any function that takes ‘FILE*’, it is not part of
     the stable ABI.

   - bpo-43795(8): Stable ABI and limited API definitions are generated
     from a central manifest ( PEP 652(9)).

   - bpo-43753(10): Add the *note Py_Is(x, y): aa2. function to test if
     the 'x' object is the 'y' object, the same as ‘x is y’ in Python.
     Add also the *note Py_IsNone(): aa3, *note Py_IsTrue(): aa4, *note
     Py_IsFalse(): aa5. functions to test if an object is, respectively,
     the ‘None’ singleton, the ‘True’ singleton or the ‘False’
     singleton.  Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43916

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43774

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43962

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28254

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43908

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43795

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43868

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43795

   (9) https://peps.python.org/pep-0652/

   (10) https://bugs.python.org/issue?@action=redirect&bpo=43753


File: python.info,  Node: Python 3 10 0 alpha 7,  Next: Python 3 10 0 alpha 6,  Prev: Python 3 10 0 beta 1,  Up: Changelog

1.24.43 Python 3.10.0 alpha 7
-----------------------------

'Release date: 2021-04-05'

* Menu:

* Security: Security<31>.
* Core and Builtins: Core and Builtins<116>.
* Library: Library<119>.
* Core and Builtins: Core and Builtins<117>.
* Library: Library<120>.
* Documentation: Documentation<37>.
* Tests: Tests<37>.
* Build: Build<44>.
* Windows: Windows<38>.
* IDLE: IDLE<21>.
* C API: C API<39>.


File: python.info,  Node: Security<31>,  Next: Core and Builtins<116>,  Up: Python 3 10 0 alpha 7

1.24.43.1 Security
..................

   - bpo-42988(1): CVE 2021-3426(2): Remove the ‘getfile’ feature of the
     *note pydoc: ba. module which could be abused to read arbitrary
     files on the disk (directory traversal vulnerability).  Moreover,
     even source code of Python modules can contain sensitive data like
     passwords.  Vulnerability reported by David Schwörer.

   - bpo-43285(3): *note ftplib: 62. no longer trusts the IP address
     value returned from the server in response to the PASV command by
     default.  This prevents a malicious FTP server from using the
     response to probe IPv4 address and port combinations on the client
     network.

     Code that requires the former vulnerable behavior may set a
     ‘trust_server_pasv_ipv4_address’ attribute on their *note
     ftplib.FTP: af8. instances to ‘True’ to re-enable it.

   - bpo-43439(4): Add audit hooks for *note gc.get_objects(): a06,
     *note gc.get_referrers(): a07. and *note gc.get_referents(): a08.
     Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42988

   (2) https://www.cve.org/CVERecord?id=CVE-2021-3426

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43285

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43439


File: python.info,  Node: Core and Builtins<116>,  Next: Library<119>,  Prev: Security<31>,  Up: Python 3 10 0 alpha 7

1.24.43.2 Core and Builtins
...........................

   - bpo-27129(1): Update CPython bytecode magic number.

   - bpo-43672(2): Raise ImportWarning when calling find_loader().

   - bpo-43660(3): Fix crash that happens when replacing ‘sys.stderr’
     with a callable that can remove the object while an exception is
     being printed.  Patch by Pablo Galindo.

   - bpo-27129(4): The bytecode interpreter uses instruction, rather
     byte, offsets internally.  This reduces the number of EXTENDED_ARG
     instructions needed and streamlines instruction dispatch a bit.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27129

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43672

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43660

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27129


File: python.info,  Node: Library<119>,  Next: Core and Builtins<117>,  Prev: Core and Builtins<116>,  Up: Python 3 10 0 alpha 7

1.24.43.3 Library
.................

   - bpo-40645(1): Fix reference leak in the ‘_hashopenssl’ extension.
     Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40645


File: python.info,  Node: Core and Builtins<117>,  Next: Library<120>,  Prev: Library<119>,  Up: Python 3 10 0 alpha 7

1.24.43.4 Core and Builtins
...........................

   - bpo-42134(1): Calls to find_module() by the import system now raise
     ImportWarning.

   - bpo-41064(2): Improve the syntax error for invalid usage of double
     starred elements (“**”) in f-strings.  Patch by Pablo Galindo.

   - bpo-43575(3): Speed up calls to ‘map()’ by using the PEP 590(4)
     ‘vectorcall’ calling convention.  Patch by Donghee Na.

   - bpo-42137(5): The import system now prefers using ‘__spec__’ for
     ‘ModuleType.__repr__’ over ‘module_repr()’.

   - bpo-43452(6): Added micro-optimizations to ‘_PyType_Lookup()’ to
     improve cache lookup performance in the common case of cache hits.

   - bpo-43555(7): Report the column offset for *note SyntaxError: 18e.
     for invalid line continuation characters.  Patch by Pablo Galindo.

   - bpo-43517(8): Fix misdetection of circular imports when using ‘from
     pkg.mod import attr’, which caused false positives in non-trivial
     multi-threaded code.

   - bpo-43497(9): Emit SyntaxWarnings for assertions with tuple
     constants, this is a regression introduced in python3.7

   - bpo-39316(10): Tracing now has correct line numbers for attribute
     accesses when the attribute is on a different line from the object.
     Improves debugging and profiling for multi-line method chains.

   - bpo-35883(11): Python no longer fails at startup with a fatal error
     if a command line argument contains an invalid Unicode character.
     The *note Py_DecodeLocale(): dc2. function now escapes byte
     sequences which would be decoded as Unicode characters outside the
     [U+0000; U+10ffff] range.

   - bpo-43410(12): Fix a bug that was causing the parser to crash when
     emitting syntax errors when reading input from stdin.  Patch by
     Pablo Galindo

   - bpo-43406(13): Fix a possible race condition where
     ‘PyErr_CheckSignals’ tries to execute a non-Python signal handler.

   - bpo-42128(14): Add ‘__match_args__’ to *note struct sequence
     objects: 13c7.  Patch by Pablo Galindo.

   - bpo-43390(15): CPython now sets the ‘SA_ONSTACK’ flag in
     ‘PyOS_setsig’ for the VM’s default signal handlers.  This is
     friendlier to other in-process code that an extension module or
     embedding use could pull in (such as Golang’s cgo) where tiny
     thread stacks are the norm and ‘sigaltstack()’ has been used to
     provide for signal handlers.  This is a no-op change for the vast
     majority of processes that don’t use sigaltstack.

   - bpo-43287(16): Speed up calls to ‘filter()’ by using the PEP
     590(17) ‘vectorcall’ calling convention.  Patch by Donghee Na.

   - bpo-37448(18): Add a radix tree based memory map to track in-use
     obmalloc arenas.  Use to replace the old implementation of
     address_in_range().  The radix tree approach makes it easy to
     increase pool sizes beyond the OS page size.  Boosting the pool and
     arena size allows obmalloc to handle a significantly higher
     percentage of requests from its ultra-fast paths.

     It also has the advantage of eliminating the memory unsanitary
     behavior of the previous address_in_range().  The old
     address_in_range() was marked with the annotations
     _Py_NO_SANITIZE_ADDRESS, _Py_NO_SANITIZE_THREAD, and
     _Py_NO_SANITIZE_MEMORY. Those annotations are no longer needed.

     To disable the radix tree map, set a preprocessor flag as follows:
     ‘-DWITH_PYMALLOC_RADIX_TREE=0’.

     Co-authored-by: Tim Peters <<tim.peters@gmail.com>>

   - bpo-29988(19): Only handle asynchronous exceptions and requests to
     drop the GIL when returning from a call or on the back edges of
     loops.  Makes sure that *note __exit__(): 1508. is always called in
     with statements, even for interrupts.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42134

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41064

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43575

   (4) https://peps.python.org/pep-0590/

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42137

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43452

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43555

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43517

   (9) https://bugs.python.org/issue?@action=redirect&bpo=43497

   (10) https://bugs.python.org/issue?@action=redirect&bpo=39316

   (11) https://bugs.python.org/issue?@action=redirect&bpo=35883

   (12) https://bugs.python.org/issue?@action=redirect&bpo=43410

   (13) https://bugs.python.org/issue?@action=redirect&bpo=43406

   (14) https://bugs.python.org/issue?@action=redirect&bpo=42128

   (15) https://bugs.python.org/issue?@action=redirect&bpo=43390

   (16) https://bugs.python.org/issue?@action=redirect&bpo=43287

   (17) https://peps.python.org/pep-0590/

   (18) https://bugs.python.org/issue?@action=redirect&bpo=37448

   (19) https://bugs.python.org/issue?@action=redirect&bpo=29988


File: python.info,  Node: Library<120>,  Next: Documentation<37>,  Prev: Core and Builtins<117>,  Up: Python 3 10 0 alpha 7

1.24.43.5 Library
.................

   - bpo-43720(1): Document various stdlib deprecations in imp, pkgutil,
     and importlib.util for removal in Python 3.12.

   - bpo-43433(2): *note xmlrpc.client.ServerProxy: c4e. no longer
     ignores query and fragment in the URL of the server.

   - bpo-31956(3): The *note index(): 9e3. method of *note array.array:
     4bf. now has optional 'start' and 'stop' parameters.

   - bpo-40066(4): Enum: adjust ‘repr()’ to show only enum and member
     name (not value, nor angle brackets) and ‘str()’ to show only
     member name.  Update and improve documentation to match.

   - bpo-42136(5): Deprecate all module_repr() methods found in
     importlib as their use is being phased out by Python 3.12.

   - bpo-35930(6): Raising an exception raised in a «future» instance
     will create reference cycles.

   - bpo-41369(7): Finish updating the vendored libmpdec to version
     2.5.1.  Patch by Stefan Krah.

   - bpo-43422(8): Revert the _decimal C API which was added in
     bpo-41324(9).

   - bpo-43577(10): Fix deadlock when using *note ssl.SSLContext: 357.
     debug callback with *note ssl.SSLContext.sni_callback(): 1c77.

   - bpo-43571(11): It’s now possible to create MPTCP sockets with
     IPPROTO_MPTCP

   - bpo-43542(12): ‘image/heic’ and ‘image/heif’ were added to *note
     mimetypes: 93.

   - bpo-40645(13): The *note hmac: 6e. module now uses OpenSSL’s HMAC
     implementation when digestmod argument is a hash name or builtin
     hash function.

   - bpo-43510(14): Implement PEP 597(15): Add ‘EncodingWarning’
     warning, ‘-X warn_default_encoding’ option, *note
     PYTHONWARNDEFAULTENCODING: 9c1. environment variable and
     ‘encoding="locale"’ argument value.

   - bpo-43521(16): ‘ast.unparse’ can now render NaNs and empty sets.

   - bpo-42914(17): *note pprint.pprint(): a2b. gains a new boolean
     ‘underscore_numbers’ optional argument to emit integers with
     thousands separated by an underscore character for improved
     readability (for example ‘1_000_000’ instead of ‘1000000’).

   - bpo-41361(18): *note rotate(): 1c78. calls are now slightly faster
     due to faster argument parsing.

   - bpo-43423(19): ‘subprocess.communicate()’ no longer raises an
     IndexError when there is an empty stdout or stderr IO buffer during
     a timeout on Windows.

   - bpo-27820(20): Fixed long-standing bug of smtplib.SMTP where doing
     AUTH LOGIN with initial_response_ok=False will fail.

     The cause is that SMTP.auth_login _always_ returns a password if
     provided with a challenge string, thus non-compliant with the
     standard for AUTH LOGIN.

     Also fixes bug with the test for smtpd.

   - bpo-43445(21): Add frozen modules to *note sys.stdlib_module_names:
     a44.  For example, add ‘"_frozen_importlib"’ and
     ‘"_frozen_importlib_external"’ names.

   - bpo-43245(22): Add keyword arguments support to
     ‘ChainMap.new_child()’.

   - bpo-29982(23): Add optional parameter 'ignore_cleanup_errors' to
     *note tempfile.TemporaryDirectory(): 143c. and allow multiple
     ‘cleanup()’ attempts.  Contributed by C.A.M. Gerlach.

   - bpo-43428(24): Include changes from importlib_metadata 3.7(25):

     Performance enhancements to distribution discovery.

     ‘entry_points’ only returns unique distributions.

     Introduces new ‘EntryPoints’ object for containing a set of entry
     points with convenience methods for selecting entry points by group
     or name.  ‘entry_points’ now returns this object if selection
     parameters are supplied but continues to return a dict object for
     compatibility.  Users are encouraged to rely on the selection
     interface.  The dict object result is likely to be deprecated in
     the future.

     Added packages_distributions function to return a mapping of
     packages to the distributions that provide them.

   - bpo-43332(26): Improves the networking efficiency of *note
     http.client: 73. when using a proxy via ‘set_tunnel()’.  Fewer
     small send calls are made during connection setup.

   - bpo-43420(27): Improve performance of *note fractions.Fraction:
     213. arithmetics for large components.  Contributed by Sergey B.
     Kirpichev.

   - bpo-43356(28): Allow passing a signal number to
     ‘_thread.interrupt_main()’.

   - bpo-43399(29): Fix ‘ElementTree.extend’ not working on iterators
     when using the Python implementation

   - bpo-43369(30): Improve *note sqlite3: d4. error handling: If
     ‘sqlite3_column_text()’ and ‘sqlite3_column_blob()’ set
     ‘SQLITE_NOMEM’, *note MemoryError: 1786. is now raised.  Patch by
     Erlend E. Aasland.

   - bpo-43368(31): Fix a regression introduced in PR 24562, where an
     empty bytestring was fetched as ‘None’ instead of ‘b''’ in *note
     sqlite3: d4.  Patch by Mariusz Felisiak.

   - bpo-41282(32): Fixed stacklevel of ‘DeprecationWarning’ emitted
     from ‘import distutils’.

   - bpo-42129(33): ‘importlib.resources’ now honors namespace packages,
     merging resources from each location in the namespace as introduced
     in ‘importlib_resources’ 3.2 and including incidental changes
     through 5.0.3.

   - bpo-43295(34): *note datetime.datetime.strptime(): 1938. now raises
     ‘ValueError’ instead of ‘IndexError’ when matching ‘'z'’ with the
     ‘%z’ format specifier.

   - bpo-43125(35): Return empty string if base64mime.body_encode
     receive empty bytes

   - bpo-43084(36): *note curses.window.enclose(): 1c79. returns now
     ‘True’ or ‘False’ (as was documented) instead of ‘1’ or ‘0’.

   - bpo-42994(37): Add MIME types for opus, AAC, 3gpp and 3gpp2

   - bpo-14678(38): Add an invalidate_caches() method to the
     zipimport.zipimporter class to support
     importlib.invalidate_caches().  Patch by Desmond Cheong.

   - bpo-42782(39): Fail fast in *note shutil.move(): c53. to avoid
     creating destination directories on failure.

   - bpo-40066(40): Enum’s ‘repr()’ and ‘str()’ have changed: ‘repr()’
     is now 'EnumClass.MemberName' and ‘str()’ is 'MemberName'.
     Additionally, stdlib Enum’s whose contents are available as module
     attributes, such as ‘RegexFlag.IGNORECASE’, have their ‘repr()’ as
     'module.name', e.g.  ‘re.IGNORECASE’.

   - bpo-26053(41): Fixed bug where the *note pdb: aa. interactive run
     command echoed the args from the shell command line, even if those
     have been overridden at the pdb prompt.

   - bpo-24160(42): Fixed bug where breakpoints did not persist across
     multiple debugger sessions in *note pdb: aa.’s interactive mode.

   - bpo-40701(43): When the *note tempfile.tempdir: 1c7a. global
     variable is set to a value of type bytes, it is now handled
     consistently.  Previously exceptions could be raised from some
     tempfile APIs when the directory did not already exist in this
     situation.  Also ensures that the *note tempfile.gettempdir():
     1c7b. and *note tempfile.gettempdirb(): 1c7c. functions 'always'
     return ‘str’ and ‘bytes’ respectively.

   - bpo-39342(44): Expose ‘X509_V_FLAG_ALLOW_PROXY_CERTS’ as *note
     VERIFY_ALLOW_PROXY_CERTS: 1c7d. to allow proxy certificate
     validation as explained in
     ‘https://docs.openssl.org/1.1.1/man7/proxy-certificates/’.

   - bpo-31861(45): Add builtins.aiter and builtins.anext.  Patch by
     Joshua Bronson (@jab), Daniel Pope (@lordmauve), and Justin Wang
     (@justin39).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43720

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43433

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31956

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40066

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42136

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35930

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41369

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43422

   (9) https://bugs.python.org/issue?@action=redirect&bpo=41324

   (10) https://bugs.python.org/issue?@action=redirect&bpo=43577

   (11) https://bugs.python.org/issue?@action=redirect&bpo=43571

   (12) https://bugs.python.org/issue?@action=redirect&bpo=43542

   (13) https://bugs.python.org/issue?@action=redirect&bpo=40645

   (14) https://bugs.python.org/issue?@action=redirect&bpo=43510

   (15) https://peps.python.org/pep-0597/

   (16) https://bugs.python.org/issue?@action=redirect&bpo=43521

   (17) https://bugs.python.org/issue?@action=redirect&bpo=42914

   (18) https://bugs.python.org/issue?@action=redirect&bpo=41361

   (19) https://bugs.python.org/issue?@action=redirect&bpo=43423

   (20) https://bugs.python.org/issue?@action=redirect&bpo=27820

   (21) https://bugs.python.org/issue?@action=redirect&bpo=43445

   (22) https://bugs.python.org/issue?@action=redirect&bpo=43245

   (23) https://bugs.python.org/issue?@action=redirect&bpo=29982

   (24) https://bugs.python.org/issue?@action=redirect&bpo=43428

   (25) 
https://importlib-metadata.readthedocs.io/en/latest/history.html#v3-7-0

   (26) https://bugs.python.org/issue?@action=redirect&bpo=43332

   (27) https://bugs.python.org/issue?@action=redirect&bpo=43420

   (28) https://bugs.python.org/issue?@action=redirect&bpo=43356

   (29) https://bugs.python.org/issue?@action=redirect&bpo=43399

   (30) https://bugs.python.org/issue?@action=redirect&bpo=43369

   (31) https://bugs.python.org/issue?@action=redirect&bpo=43368

   (32) https://bugs.python.org/issue?@action=redirect&bpo=41282

   (33) https://bugs.python.org/issue?@action=redirect&bpo=42129

   (34) https://bugs.python.org/issue?@action=redirect&bpo=43295

   (35) https://bugs.python.org/issue?@action=redirect&bpo=43125

   (36) https://bugs.python.org/issue?@action=redirect&bpo=43084

   (37) https://bugs.python.org/issue?@action=redirect&bpo=42994

   (38) https://bugs.python.org/issue?@action=redirect&bpo=14678

   (39) https://bugs.python.org/issue?@action=redirect&bpo=42782

   (40) https://bugs.python.org/issue?@action=redirect&bpo=40066

   (41) https://bugs.python.org/issue?@action=redirect&bpo=26053

   (42) https://bugs.python.org/issue?@action=redirect&bpo=24160

   (43) https://bugs.python.org/issue?@action=redirect&bpo=40701

   (44) https://bugs.python.org/issue?@action=redirect&bpo=39342

   (45) https://bugs.python.org/issue?@action=redirect&bpo=31861


File: python.info,  Node: Documentation<37>,  Next: Tests<37>,  Prev: Library<120>,  Up: Python 3 10 0 alpha 7

1.24.43.6 Documentation
.......................

   - bpo-43199(1): Answer «Why is there no goto?» in the Design and
     History FAQ.

   - bpo-43407(2): Clarified that a result from *note time.monotonic():
     55c, *note time.perf_counter(): c7c, *note time.process_time():
     c7d, or *note time.thread_time(): b32. can be compared with the
     result from any following call to the same function - not just the
     next immediate call.

   - bpo-43354(3): Fix type documentation for ‘Fault.faultCode’; the
     type has to be ‘int’ instead of ‘str’.

   - bpo-41933(4): Clarified wording of s * n in the Common Sequence
     Operations

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43199

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43407

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43354

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41933


File: python.info,  Node: Tests<37>,  Next: Build<44>,  Prev: Documentation<37>,  Up: Python 3 10 0 alpha 7

1.24.43.7 Tests
...............

   - bpo-37945(1): Fix test_getsetlocale_issue1813() of test_locale:
     skip the test if ‘setlocale()’ fails.  Patch by Victor Stinner.

   - bpo-41561(2): Add workaround for Ubuntu’s custom OpenSSL security
     level policy.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37945

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41561


File: python.info,  Node: Build<44>,  Next: Windows<38>,  Prev: Tests<37>,  Up: Python 3 10 0 alpha 7

1.24.43.8 Build
...............

   - bpo-43179(1): Introduce and correctly use ALIGNOF_X in place of
     SIZEOF_X for alignment-related code in optimized string routines.
     Patch by Jessica Clarke.

   - bpo-43631(2): Update macOS, Windows, and CI to OpenSSL 1.1.1k.

   - bpo-43617(3): Improve configure.ac: Check for presence of
     autoconf-archive package and remove our copies of M4 macros.

   - bpo-43466(4): The ‘configure’ script now supports
     ‘--with-openssl-rpath’ option.

   - bpo-43372(5): Use ‘_freeze_importlib’ to generate code for the
     ‘__hello__’ module.  This approach ensures the code matches the
     interpreter version.  Previously, PYTHON_FOR_REGEN was used to
     generate the code, which might be wrong.  The marshal format for
     code objects has changed with bpo-42246(6), commit 877df851.
     Update the code and the expected code sizes in ctypes
     test_frozentable.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43179

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43631

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43617

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43466

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43372

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42246


File: python.info,  Node: Windows<38>,  Next: IDLE<21>,  Prev: Build<44>,  Up: Python 3 10 0 alpha 7

1.24.43.9 Windows
.................

   - bpo-43440(1): Build *note sqlite3: d4. with the ‘R*Tree’ module
     enabled.  Patch by Erlend E. Aasland.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43440


File: python.info,  Node: IDLE<21>,  Next: C API<39>,  Prev: Windows<38>,  Up: Python 3 10 0 alpha 7

1.24.43.10 IDLE
...............

   - bpo-42225(1): Document that IDLE can fail on Unix either from
     misconfigured IP masquerade rules or failure displaying complex
     colored (non-ascii) characters.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42225


File: python.info,  Node: C API<39>,  Prev: IDLE<21>,  Up: Python 3 10 0 alpha 7

1.24.43.11 C API
................

   - bpo-43688(1): The limited C API is now supported if Python is built
     in debug mode (if the ‘Py_DEBUG’ macro is defined).  In the limited
     C API, the *note Py_INCREF(): 790. and *note Py_DECREF(): 791.
     functions are now implemented as opaque function calls, rather than
     accessing directly the *note PyObject.ob_refcnt: aa1. member, if
     Python is built in debug mode and the ‘Py_LIMITED_API’ macro
     targets Python 3.10 or newer.  It became possible to support the
     limited C API in debug mode because the *note PyObject: 5df.
     structure is the same in release and debug mode since Python 3.8
     (see bpo-36465(2)).

     The limited C API is still not supported in the ‘--with-trace-refs’
     special build (‘Py_TRACE_REFS’ macro).

     Patch by Victor Stinner.

   - bpo-43244(3): Remove the ‘pyarena.h’ header file with functions:

        * ‘PyArena_New()’

        * ‘PyArena_Free()’

        * ‘PyArena_Malloc()’

        * ‘PyArena_AddPyObject()’

     These functions were undocumented, excluded from the limited C API,
     and were only used internally by the compiler.  Patch by Victor
     Stinner.

   - bpo-43244(4): Remove the compiler and parser functions using
     ‘struct _mod’ type, because the public AST C API was removed:

        * ‘PyAST_Compile()’

        * ‘PyAST_CompileEx()’

        * ‘PyAST_CompileObject()’

        * ‘PyFuture_FromAST()’

        * ‘PyFuture_FromASTObject()’

        * ‘PyParser_ASTFromFile()’

        * ‘PyParser_ASTFromFileObject()’

        * ‘PyParser_ASTFromFilename()’

        * ‘PyParser_ASTFromString()’

        * ‘PyParser_ASTFromStringObject()’

     These functions were undocumented and excluded from the limited C
     API. Patch by Victor Stinner.

   - bpo-43244(5): Remove ‘ast.h’, ‘asdl.h’, and ‘Python-ast.h’ header
     files.  These functions were undocumented and excluded from the
     limited C API. Most names defined by these header files were not
     prefixed by ‘Py’ and so could create names conflicts.  For example,
     ‘Python-ast.h’ defined a ‘Yield’ macro which was conflict with the
     ‘Yield’ name used by the Windows ‘<winbase.h>’ header.  Use the
     Python *note ast: 9. module instead.  Patch by Victor Stinner.

   - bpo-43541(6): Fix a ‘PyEval_EvalCodeEx()’ regression: fix reference
     counting on builtins.  Patch by Victor Stinner.

   - bpo-43244(7): Remove the ‘symtable.h’ header file and the
     undocumented functions:

        * ‘PyST_GetScope()’

        * ‘PySymtable_Build()’

        * ‘PySymtable_BuildObject()’

        * ‘PySymtable_Free()’

        * ‘Py_SymtableString()’

        * ‘Py_SymtableStringObject()’

     The ‘Py_SymtableString()’ function was part the stable ABI by
     mistake but it could not be used, because the ‘symtable.h’ header
     file was excluded from the limited C API.

     The Python *note symtable: de. module remains available and is
     unchanged.

     Patch by Victor Stinner.

   - bpo-43244(8): Remove the ‘PyAST_Validate()’ function.  It is no
     longer possible to build a AST object (‘mod_ty’ type) with the
     public C API. The function was already excluded from the limited C
     API ( PEP 384(9)).  Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43688

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36465

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43244

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43244

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43244

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43541

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43244

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43244

   (9) https://peps.python.org/pep-0384/


File: python.info,  Node: Python 3 10 0 alpha 6,  Next: Python 3 10 0 alpha 5,  Prev: Python 3 10 0 alpha 7,  Up: Changelog

1.24.44 Python 3.10.0 alpha 6
-----------------------------

'Release date: 2021-03-01'

* Menu:

* Security: Security<32>.
* Core and Builtins: Core and Builtins<118>.
* Library: Library<121>.
* Core and Builtins: Core and Builtins<119>.
* Library: Library<122>.
* Core and Builtins: Core and Builtins<120>.
* Library: Library<123>.
* Documentation: Documentation<38>.
* Tests: Tests<38>.
* Build: Build<45>.
* Windows: Windows<39>.
* macOS: macOS<28>.
* IDLE: IDLE<22>.
* C API: C API<40>.


File: python.info,  Node: Security<32>,  Next: Core and Builtins<118>,  Up: Python 3 10 0 alpha 6

1.24.44.1 Security
..................

   - bpo-42967(1): Fix web cache poisoning vulnerability by defaulting
     the query args separator to ‘&’, and allowing the user to choose a
     custom separator.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42967


File: python.info,  Node: Core and Builtins<118>,  Next: Library<121>,  Prev: Security<32>,  Up: Python 3 10 0 alpha 6

1.24.44.2 Core and Builtins
...........................

   - bpo-43321(1): Fix ‘SystemError’ raised when ‘PyArg_Parse*()’ is
     used with ‘#’ but without ‘PY_SSIZE_T_CLEAN’ defined.

   - bpo-36346(2): ‘PyArg_Parse*()’ functions now emits
     ‘DeprecationWarning’ when ‘u’ or ‘Z’ format is used.  See PEP
     623(3) for detail.

   - bpo-43277(4): Add a new *note PySet_CheckExact(): a9f. function to
     the C-API to check if an object is an instance of *note set: 184.
     but not an instance of a subtype.  Patch by Pablo Galindo.

   - bpo-42990(5): The *note types.FunctionType: a85. constructor now
     inherits the current builtins if the 'globals' dictionary has no
     ‘"__builtins__"’ key, rather than using ‘{"None": None}’ as
     builtins: same behavior as *note eval(): 4a4. and *note exec():
     4a3. functions.  Defining a function with ‘def function(...): ...’
     in Python is not affected, globals cannot be overridden with this
     syntax: it also inherits the current builtins.  Patch by Victor
     Stinner.

   - bpo-42990(6): Functions have a new ‘__builtins__’ attribute which
     is used to look for builtin symbols when a function is executed,
     instead of looking into ‘__globals__['__builtins__']’.  Patch by
     Mark Shannon and Victor Stinner.

   - bpo-43149(7): Improve the error message in the parser for exception
     groups without parentheses.  Patch by Pablo Galindo.

   - bpo-43121(8): Fixed an incorrect *note SyntaxError: 18e. message
     for missing comma in literals.  Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43321

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36346

   (3) https://peps.python.org/pep-0623/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43277

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42990

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42990

   (7) https://bugs.python.org/issue?@action=redirect&bpo=43149

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43121


File: python.info,  Node: Library<121>,  Next: Core and Builtins<119>,  Prev: Core and Builtins<118>,  Up: Python 3 10 0 alpha 6

1.24.44.3 Library
.................

   - bpo-42819(1): *note readline: bf.: Explicitly disable bracketed
     paste in the interactive interpreter, even if it’s set in the
     inputrc, is enabled by default (eg GNU Readline 8.1), or a user
     calls ‘readline.read_init_file()’.  The Python REPL has not
     implemented bracketed paste support.  Also, bracketed mode writes
     the ‘"\x1b[?2004h"’ escape sequence into stdout which causes test
     failures in applications that don’t support it.  It can still be
     explicitly enabled by calling ‘readline.parse_and_bind("set
     enable-bracketed-paste on")’.  Patch by Dustin Rodrigues.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42819


File: python.info,  Node: Core and Builtins<119>,  Next: Library<122>,  Prev: Library<121>,  Up: Python 3 10 0 alpha 6

1.24.44.4 Core and Builtins
...........................

   - bpo-42808(1): Simple calls to ‘type(object)’ are now faster due to
     the ‘vectorcall’ calling convention.  Patch by Dennis Sweeney.

   - bpo-42217(2): Make the compiler merges same co_code and
     co_linetable objects in a module like already did for co_consts.

   - bpo-41972(3): Substring search functions such as ‘str1 in str2’ and
     ‘str2.find(str1)’ now sometimes use the «Two-Way» string comparison
     algorithm to avoid quadratic behavior on long strings.

   - bpo-42128(4): Implement PEP 634(5) (structural pattern matching).
     Patch by Brandt Bucher.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42808

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42217

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41972

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42128

   (5) https://peps.python.org/pep-0634/


File: python.info,  Node: Library<122>,  Next: Core and Builtins<120>,  Prev: Core and Builtins<119>,  Up: Python 3 10 0 alpha 6

1.24.44.5 Library
.................

   - bpo-40692(1): In the *note concurrent.futures.ProcessPoolExecutor:
     1d6, validate that ‘multiprocess.synchronize()’ is available on a
     given platform and rely on that check in the *note
     concurrent.futures: 24. test suite so we can run tests that are
     unrelated to ‘ProcessPoolExecutor’ on those platforms.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40692


File: python.info,  Node: Core and Builtins<120>,  Next: Library<123>,  Prev: Library<122>,  Up: Python 3 10 0 alpha 6

1.24.44.6 Core and Builtins
...........................

   - bpo-38302(1): If *note object.__ipow__(): 9d5. returns *note
     NotImplemented: 1a2, the operator will correctly fall back to *note
     object.__pow__(): 9d6. and *note object.__rpow__(): 1a5. as
     expected.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38302


File: python.info,  Node: Library<123>,  Next: Documentation<38>,  Prev: Core and Builtins<120>,  Up: Python 3 10 0 alpha 6

1.24.44.7 Library
.................

   - bpo-43316(1): The ‘python -m gzip’ command line application now
     properly fails when detecting an unsupported extension.  It exits
     with a non-zero exit code and prints an error message to stderr.

   - bpo-43317(2): Set the chunk size for the ‘gzip’ module main
     function to io.DEFAULT_BUFFER_SIZE. This is slightly faster than
     the 1024 bytes constant that was used previously.

   - bpo-43146(3): Handle None in single-arg versions of *note
     print_exception(): a51. and *note format_exception(): a4f.

   - bpo-43260(4): Fix TextIOWrapper can not flush internal buffer
     forever after very large text is written.

   - bpo-43258(5): Prevent needless allocation of *note sqlite3: d4.
     aggregate function context when no rows match an aggregate query.
     Patch by Erlend E. Aasland.

   - bpo-43251(6): Improve *note sqlite3: d4. error handling:
     ‘sqlite3_column_name()’ failures now result in *note MemoryError:
     1786.  Patch by Erlend E. Aasland.

   - bpo-40956(7): Fix segfault in *note sqlite3.Connection.backup():
     d75. if no argument was provided.  The regression was introduced by
     PR 23838.  Patch by Erlend E. Aasland.

   - bpo-43172(8): The readline module now passes its tests when built
     directly against libedit.  Existing irreconcilable API differences
     remain in *note readline.get_begidx(): 1c8c. and *note
     readline.get_endidx(): 1c8d. behavior based on libreadline vs
     libedit use.

   - bpo-43163(9): Fix a bug in *note codeop: 1d. that was causing it to
     not ask for more input when multi-line snippets have unclosed
     parentheses.  Patch by Pablo Galindo

   - bpo-43162(10): deprecate unsupported ability to access enum members
     as attributes of other enum members

   - bpo-43146(11): Fix recent regression in None argument handling in
     *note traceback: 104. module functions.

   - bpo-43102(12): The namedtuple __new__ method had its __builtins__
     set to None instead of an actual dictionary.  This created problems
     for introspection tools.

   - bpo-43106(13): Added *note O_EVTONLY: a1d, *note O_FSYNC: a1e,
     *note O_SYMLINK: a1f. and *note O_NOFOLLOW_ANY: a20. for macOS.
     Patch by Donghee Na.

   - bpo-42960(14): Adds *note resource.RLIMIT_KQUEUES: 1c8e. constant
     from FreeBSD to the *note resource: c1. module.

   - bpo-42151(15): Make the pure Python implementation of *note
     xml.etree.ElementTree: 12b. behave the same as the C implementation
     (‘_elementree’) regarding default attribute values (by not setting
     ‘specified_attributes=1’).

   - bpo-29753(16): In ctypes, now packed bitfields are calculated
     properly and the first item of packed bitfields is now shrank
     correctly.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43316

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43317

   (3) https://bugs.python.org/issue?@action=redirect&bpo=43146

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43260

   (5) https://bugs.python.org/issue?@action=redirect&bpo=43258

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43251

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40956

   (8) https://bugs.python.org/issue?@action=redirect&bpo=43172

   (9) https://bugs.python.org/issue?@action=redirect&bpo=43163

   (10) https://bugs.python.org/issue?@action=redirect&bpo=43162

   (11) https://bugs.python.org/issue?@action=redirect&bpo=43146

   (12) https://bugs.python.org/issue?@action=redirect&bpo=43102

   (13) https://bugs.python.org/issue?@action=redirect&bpo=43106

   (14) https://bugs.python.org/issue?@action=redirect&bpo=42960

   (15) https://bugs.python.org/issue?@action=redirect&bpo=42151

   (16) https://bugs.python.org/issue?@action=redirect&bpo=29753


File: python.info,  Node: Documentation<38>,  Next: Tests<38>,  Prev: Library<123>,  Up: Python 3 10 0 alpha 6

1.24.44.8 Documentation
.......................

   - bpo-27646(1): Clarify that “yield from <expr>” works with any
     iterable, not just iterators.

   - bpo-36346(2): Update some deprecated unicode APIs which are
     documented as «will be removed in 4.0» to «3.12».  See PEP 623(3)
     for detail.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27646

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36346

   (3) https://peps.python.org/pep-0623/


File: python.info,  Node: Tests<38>,  Next: Build<45>,  Prev: Documentation<38>,  Up: Python 3 10 0 alpha 6

1.24.44.9 Tests
...............

   - bpo-43288(1): Fix test_importlib to correctly skip Unicode file
     tests if the filesystem does not support them.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43288


File: python.info,  Node: Build<45>,  Next: Windows<39>,  Prev: Tests<38>,  Up: Python 3 10 0 alpha 6

1.24.44.10 Build
................

   - bpo-43174(1): Windows build now uses ‘/utf-8’ compiler option.

   - bpo-43103(2): Add a new configure ‘--without-static-libpython’
     option to not build the ‘libpythonMAJOR.MINOR.a’ static library and
     not install the ‘python.o’ object file.

   - bpo-13501(3): The configure script can now use 'libedit' instead of
     'readline' with the command line option ‘--with-readline=editline’.

   - bpo-42603(4): Make configure script use pkg-config to detect the
     location of Tcl/Tk headers and libraries, used to build tkinter.

     On macOS, a Tcl/Tk configuration provided by pkg-config will be
     preferred over Tcl/Tk frameworks installed in
     ‘/{System/,}Library/Frameworks’.  If both exist and the latter is
     preferred, the appropriate ‘--with-tcltk-*’ configuration options
     need to be explicitly set.

   - bpo-39448(5): Add the «regen-frozen» makefile target that
     regenerates the code for the frozen ‘__hello__’ module.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43174

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43103

   (3) https://bugs.python.org/issue?@action=redirect&bpo=13501

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42603

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39448


File: python.info,  Node: Windows<39>,  Next: macOS<28>,  Prev: Build<45>,  Up: Python 3 10 0 alpha 6

1.24.44.11 Windows
..................

   - bpo-43155(1): *note PyCMethod_New(): 1c93. is now present in
     ‘python3.lib’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43155


File: python.info,  Node: macOS<28>,  Next: IDLE<22>,  Prev: Windows<39>,  Up: Python 3 10 0 alpha 6

1.24.44.12 macOS
................

   - bpo-41837(1): Update macOS installer build to use OpenSSL 1.1.1j.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41837


File: python.info,  Node: IDLE<22>,  Next: C API<40>,  Prev: macOS<28>,  Up: Python 3 10 0 alpha 6

1.24.44.13 IDLE
...............

   - bpo-43283(1): Document why printing to IDLE’s Shell is often slower
     than printing to a system terminal and that it can be made faster
     by pre-formatting a single string before printing.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43283


File: python.info,  Node: C API<40>,  Prev: IDLE<22>,  Up: Python 3 10 0 alpha 6

1.24.44.14 C API
................

   - bpo-43278(1): Always put compiler and system information on the
     first line of the REPL welcome message.

   - bpo-43270(2): Remove the private ‘_PyErr_OCCURRED()’ macro: use the
     public *note PyErr_Occurred(): 1c97. function instead.

   - bpo-35134(3): Move odictobject.h, parser_interface.h,
     picklebufobject.h, pydebug.h, and pyfpe.h into the cpython/
     directory.  They must not be included directly, as they are already
     included by Python.h: *note Include Files: 988.

   - bpo-35134(4): Move pyarena.h, pyctype.h, and pytime.h into the
     cpython/ directory.  They must not be included directly, as they
     are already included by Python.h: *note Include Files: 988.

   - bpo-40170(5): *note PyExceptionClass_Name(): c5d. is now always
     declared as a function, in order to hide implementation details.
     The macro accessed *note PyTypeObject.tp_name: 1c98. directly.
     Patch by Erlend E. Aasland.

   - bpo-43239(6): The *note PyCFunction_New(): 1c99. function is now
     exported in the ABI when compiled with ‘-fvisibility=hidden’.

   - bpo-40170(7): *note PyIter_Check(): 1c9a. is now always declared as
     a function, in order to hide implementation details.  The macro
     accessed *note PyTypeObject.tp_iternext: 16f7. directly.  Patch by
     Erlend E. Aasland.

   - bpo-40170(8): Convert *note PyDescr_IsData(): 1c9b. macro to a
     function to hide implementation details: The macro accessed *note
     PyTypeObject.tp_descr_set: 1c9c. directly.  Patch by Erlend E.
     Aasland.

   - bpo-43181(9): Convert *note PyObject_TypeCheck(): 1c9d. macro to a
     static inline function.  Patch by Erlend E. Aasland.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43278

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43270

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35134

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35134

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (6) https://bugs.python.org/issue?@action=redirect&bpo=43239

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (8) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (9) https://bugs.python.org/issue?@action=redirect&bpo=43181


File: python.info,  Node: Python 3 10 0 alpha 5,  Next: Python 3 10 0 alpha 4,  Prev: Python 3 10 0 alpha 6,  Up: Changelog

1.24.45 Python 3.10.0 alpha 5
-----------------------------

'Release date: 2021-02-02'

* Menu:

* Security: Security<33>.
* Core and Builtins: Core and Builtins<121>.
* Library: Library<124>.
* Core and Builtins: Core and Builtins<122>.
* Library: Library<125>.
* Documentation: Documentation<39>.
* Tests: Tests<39>.
* Build: Build<46>.
* Windows: Windows<40>.
* macOS: macOS<29>.
* IDLE: IDLE<23>.
* C API: C API<41>.


File: python.info,  Node: Security<33>,  Next: Core and Builtins<121>,  Up: Python 3 10 0 alpha 5

1.24.45.1 Security
..................

   - bpo-42938(1): Avoid static buffers when computing the repr of *note
     ctypes.c_double: 1ca0. and *note ctypes.c_longdouble: 1ca1. values.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42938


File: python.info,  Node: Core and Builtins<121>,  Next: Library<124>,  Prev: Security<33>,  Up: Python 3 10 0 alpha 5

1.24.45.2 Core and Builtins
...........................

   - bpo-42990(1): Refactor the ‘PyEval_’ family of functions.

        * An new function ‘_PyEval_Vector’ is added to simplify calls to
          Python from C.

        * ‘_PyEval_EvalCodeWithName’ is removed

        * ‘PyEval_EvalCodeEx’ is retained as part of the API, but is not
          used internally

   - bpo-38631(2): Replace *note Py_FatalError(): b7c. calls in the
     compiler with regular *note SystemError: 796. exceptions.  Patch by
     Victor Stinner.

   - bpo-42997(3): Improve error message for missing «:» before blocks.
     Patch by Pablo Galindo.

   - bpo-43017(4): Improve error message in the parser when using
     un-parenthesised tuples in comprehensions.  Patch by Pablo Galindo.

   - bpo-42986(5): Fix parser crash when reporting syntax errors in
     f-string with newlines.  Patch by Pablo Galindo.

   - bpo-40176(6): Syntax errors for unterminated string literals now
     point to the start of the string instead of reporting EOF/EOL.

   - bpo-42927(7): The inline cache for ‘LOAD_ATTR’ now also optimizes
     access to attributes defined by ‘__slots__’.  This makes reading
     such attribute up to 30% faster.

   - bpo-42864(8): Improve error messages in the parser when parentheses
     are not closed.  Patch by Pablo Galindo.

   - bpo-42924(9): Fix ‘bytearray’ repetition incorrectly copying data
     from the start of the buffer, even if the data is offset within the
     buffer (e.g.  after reassigning a slice at the start of the
     ‘bytearray’ to a shorter byte string).

   - bpo-42882(10): Fix the ‘_PyUnicode_FromId()’ function
     (_Py_IDENTIFIER(var) API) when *note Py_Initialize(): 460. / *note
     Py_Finalize(): 45f. is called multiple times: preserve
     ‘_PyRuntime.unicode_ids.next_index’ value.

   - bpo-42827(11): Fix a crash when working out the error line of a
     *note SyntaxError: 18e. in some multi-line expressions.

   - bpo-42823(12): frame.f_lineno is correct even if frame.f_trace is
     set to True

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42990

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38631

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42997

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43017

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42986

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40176

   (7) https://bugs.python.org/issue?@action=redirect&bpo=42927

   (8) https://bugs.python.org/issue?@action=redirect&bpo=42864

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42924

   (10) https://bugs.python.org/issue?@action=redirect&bpo=42882

   (11) https://bugs.python.org/issue?@action=redirect&bpo=42827

   (12) https://bugs.python.org/issue?@action=redirect&bpo=42823


File: python.info,  Node: Library<124>,  Next: Core and Builtins<122>,  Prev: Core and Builtins<121>,  Up: Python 3 10 0 alpha 5

1.24.45.3 Library
.................

   - bpo-37324(1): Remove deprecated aliases to *note Collections
     Abstract Base Classes: a7a. from the *note collections: 1e. module.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37324


File: python.info,  Node: Core and Builtins<122>,  Next: Library<125>,  Prev: Library<124>,  Up: Python 3 10 0 alpha 5

1.24.45.4 Core and Builtins
...........................

   - bpo-41994(1): Fixed possible leak in ‘import’ when ‘sys.modules’ is
     not a ‘dict’.

   - bpo-27772(2): In string formatting, preceding the 'width' field by
     ‘'0'’ no longer affects the default alignment for strings.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41994

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27772


File: python.info,  Node: Library<125>,  Next: Documentation<39>,  Prev: Core and Builtins<122>,  Up: Python 3 10 0 alpha 5

1.24.45.5 Library
.................

   - bpo-43108(1): Fixed a reference leak in the *note curses: 2f.
     module.  Patch by Pablo Galindo

   - bpo-43077(2): Update the bundled pip to 21.0.1 and setuptools to
     52.0.0.

   - bpo-41282(3): Deprecate ‘distutils’ in documentation and add
     warning on import.

   - bpo-43014(4): Improve performance of *note tokenize: 101. by
     20-30%.  Patch by Anthony Sottile.

   - bpo-42323(5): Fix *note math.nextafter(): 6c1. for NaN on AIX.

   - bpo-42955(6): Add *note sys.stdlib_module_names: a44, containing
     the list of the standard library module names.  Patch by Victor
     Stinner.

   - bpo-42944(7): Fix ‘random.Random.sample’ when ‘counts’ argument is
     not ‘None’.

   - bpo-42934(8): Use *note TracebackException: 563.’s new ‘compact’
     param in *note TestResult: 136f. to reduce time and memory consumed
     by traceback formatting.

   - bpo-42931(9): Add ‘randbytes()’ to ‘random.__all__’.

   - bpo-38250(10): [Enum] Flags consisting of a single bit are now
     considered canonical, and will be the only flags returned from
     listing and iterating over a Flag class or a Flag member.
     Multi-bit flags are considered aliases; they will be returned from
     lookups and operations that result in their value.  Iteration for
     both Flag and Flag members is in definition order.

   - bpo-42877(11): Added the ‘compact’ parameter to the constructor of
     *note traceback.TracebackException: 563. to reduce time and memory
     for use cases that only need to call ‘TracebackException.format()’
     and ‘TracebackException.format_exception_only()’.

   - bpo-42923(12): The *note Py_FatalError(): b7c. function and the
     *note faulthandler: 5c. module now dump the list of extension
     modules on a fatal error.

   - bpo-42848(13): Removed recursion from *note TracebackException:
     563. to allow it to handle long exception chains.

   - bpo-42901(14): [Enum] move member creation from ‘EnumMeta.__new__’
     to ‘_proto_member.__set_name__’, allowing members to be created and
     visible in ‘__init_subclass__’.

   - bpo-42780(15): Fix os.set_inheritable() for O_PATH file descriptors
     on Linux.

   - bpo-42866(16): Fix a reference leak in the ‘getcodec()’ function of
     CJK codecs.  Patch by Victor Stinner.

   - bpo-42846(17): Convert the 6 CJK codec extension modules
     (_codecs_cn, _codecs_hk, _codecs_iso2022, _codecs_jp, _codecs_kr
     and _codecs_tw) to the multiphase initialization API ( PEP
     489(18)).  Patch by Victor Stinner.

   - bpo-42851(19): remove __init_subclass__ support for Enum members

   - bpo-42834(20): Make internal caches of the ‘_json’ module
     compatible with subinterpreters.

   - bpo-41748(21): Fix HTMLParser parsing rules for element attributes
     containing commas with spaces.  Patch by Karl Dubost.

   - bpo-40810(22): Require SQLite 3.7.15 or newer.  Patch by Erlend E.
     Aasland.

   - bpo-1635741(23): Convert the _multibytecodec extension module (CJK
     codecs) to multi-phase initialization ( PEP 489(24)).  Patch by
     Erlend E. Aasland.

   - bpo-42802(25): The distutils ‘bdist_wininst’ command deprecated in
     Python 3.8 has been removed.  The distutils ‘bdist_wheel’ command
     is now recommended to distribute binary packages on Windows.

   - bpo-24464(26): The undocumented built-in function
     ‘sqlite3.enable_shared_cache’ is now deprecated, scheduled for
     removal in Python 3.12.  Its use is strongly discouraged by the
     SQLite3 documentation.  Patch by Erlend E. Aasland.

   - bpo-42384(27): Make pdb populate sys.path[0] exactly the same as
     regular python execution.

   - bpo-42383(28): Fix pdb: previously pdb would fail to restart the
     debugging target if it was specified using a relative path and the
     current directory changed.

   - bpo-42005(29): Fix CLI of *note cProfile: 2b. and *note profile:
     b4. to catch *note BrokenPipeError: 125e.

   - bpo-41604(30): Don’t decrement the reference count of the previous
     user_ptr when set_panel_userptr fails.

   - bpo-41149(31): Allow executing callables that have a boolean value
     of ‘False’ when passed to ‘Threading.thread’ as the target.  Patch
     contributed by Barney Stratford.

   - bpo-38307(32): Add an “end_lineno” attribute to the Class and
     Function objects that appear in the tree returned by pyclbr
     functions.  This and the existing “lineno” attribute define the
     extent of class and def statements.  Patch by Aviral Srivastava.

   - bpo-39273(33): The ‘BUTTON5_*’ constants are now exposed in the
     *note curses: 2f. module if available.

   - bpo-33289(34): Correct call to *note tkinter.colorchooser: f7. to
     return RGB triplet of ints instead of floats.  Patch by Cheryl
     Sabella.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43108

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43077

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41282

   (4) https://bugs.python.org/issue?@action=redirect&bpo=43014

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42323

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42955

   (7) https://bugs.python.org/issue?@action=redirect&bpo=42944

   (8) https://bugs.python.org/issue?@action=redirect&bpo=42934

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42931

   (10) https://bugs.python.org/issue?@action=redirect&bpo=38250

   (11) https://bugs.python.org/issue?@action=redirect&bpo=42877

   (12) https://bugs.python.org/issue?@action=redirect&bpo=42923

   (13) https://bugs.python.org/issue?@action=redirect&bpo=42848

   (14) https://bugs.python.org/issue?@action=redirect&bpo=42901

   (15) https://bugs.python.org/issue?@action=redirect&bpo=42780

   (16) https://bugs.python.org/issue?@action=redirect&bpo=42866

   (17) https://bugs.python.org/issue?@action=redirect&bpo=42846

   (18) https://peps.python.org/pep-0489/

   (19) https://bugs.python.org/issue?@action=redirect&bpo=42851

   (20) https://bugs.python.org/issue?@action=redirect&bpo=42834

   (21) https://bugs.python.org/issue?@action=redirect&bpo=41748

   (22) https://bugs.python.org/issue?@action=redirect&bpo=40810

   (23) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (24) https://peps.python.org/pep-0489/

   (25) https://bugs.python.org/issue?@action=redirect&bpo=42802

   (26) https://bugs.python.org/issue?@action=redirect&bpo=24464

   (27) https://bugs.python.org/issue?@action=redirect&bpo=42384

   (28) https://bugs.python.org/issue?@action=redirect&bpo=42383

   (29) https://bugs.python.org/issue?@action=redirect&bpo=42005

   (30) https://bugs.python.org/issue?@action=redirect&bpo=41604

   (31) https://bugs.python.org/issue?@action=redirect&bpo=41149

   (32) https://bugs.python.org/issue?@action=redirect&bpo=38307

   (33) https://bugs.python.org/issue?@action=redirect&bpo=39273

   (34) https://bugs.python.org/issue?@action=redirect&bpo=33289


File: python.info,  Node: Documentation<39>,  Next: Tests<39>,  Prev: Library<125>,  Up: Python 3 10 0 alpha 5

1.24.45.6 Documentation
.......................

   - bpo-40304(1): Fix doc for type(name, bases, dict).  Patch by Boris
     Verkhovskiy and Éric Araujo.

   - bpo-42811(2): Updated importlib.util.resolve_name() doc to use
     __spec__.parent instead of __package__.  (Thanks Yair Frid.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40304

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42811


File: python.info,  Node: Tests<39>,  Next: Build<46>,  Prev: Documentation<39>,  Up: Python 3 10 0 alpha 5

1.24.45.7 Tests
...............

   - bpo-40823(1): Use ‘unittest.TestLoader().loadTestsFromTestCase()’
     instead of ‘unittest.makeSuite()’ in *note sqlite3: d4. tests.
     Patch by Erlend E. Aasland.

   - bpo-40810(2): In *note sqlite3: d4, fix ‘CheckTraceCallbackContent’
     for SQLite pre 3.7.15.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40823

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40810


File: python.info,  Node: Build<46>,  Next: Windows<40>,  Prev: Tests<39>,  Up: Python 3 10 0 alpha 5

1.24.45.8 Build
...............

   - bpo-43031(1): Pass ‘--timeout=$(TESTTIMEOUT)’ option to the default
     profile task ‘./python -m test --pgo’ command.

   - bpo-36143(2): ‘make regen-all’ now also runs ‘regen-keyword’.
     Patch by Victor Stinner.

   - bpo-42874(3): Removed the grep -q and -E flags in the tzpath
     validation section of the configure script to better accommodate
     users of some platforms (specifically Solaris 10).

   - bpo-31904(4): Add library search path by wr-cc in
     add_cross_compiling_paths() for VxWorks.

   - bpo-42856(5): Add ‘--with-wheel-pkg-dir=PATH’ option to the
     ‘./configure’ script.  If specified, the *note ensurepip: 59.
     module looks for ‘setuptools’ and ‘pip’ wheel packages in this
     directory: if both are present, these wheel packages are used
     instead of ensurepip bundled wheel packages.

     Some Linux distribution packaging policies recommend against
     bundling dependencies.  For example, Fedora installs wheel packages
     in the ‘/usr/share/python-wheels/’ directory and don’t install the
     ‘ensurepip._bundled’ package.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43031

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36143

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42874

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42856


File: python.info,  Node: Windows<40>,  Next: macOS<29>,  Prev: Build<46>,  Up: Python 3 10 0 alpha 5

1.24.45.9 Windows
.................

   - bpo-41837(1): Updated Windows installer to include OpenSSL 1.1.1i

   - bpo-42584(2): Upgrade Windows installer to use SQLite 3.34.0.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41837

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42584


File: python.info,  Node: macOS<29>,  Next: IDLE<23>,  Prev: Windows<40>,  Up: Python 3 10 0 alpha 5

1.24.45.10 macOS
................

   - bpo-42504(1): Ensure that the value of
     sysconfig.get_config_var(“MACOSX_DEPLOYMENT_TARGET”) is always a
     string, even in when the value is parsable as an integer.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42504


File: python.info,  Node: IDLE<23>,  Next: C API<41>,  Prev: macOS<29>,  Up: Python 3 10 0 alpha 5

1.24.45.11 IDLE
...............

   - bpo-43008(1): Make IDLE invoke *note sys.excepthook(): a0e. in
     normal, 2-process mode.  Patch by Ken Hilton.

   - bpo-33065(2): Fix problem debugging user classes with __repr__
     method.

   - bpo-23544(3): Disable Debug=>Stack Viewer when user code is running
     or Debugger is active, to prevent hang or crash.  Patch by Zackery
     Spytz.

   - bpo-32631(4): Finish zzdummy example extension module: make menu
     entries work; add docstrings and tests with 100% coverage.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=43008

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33065

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23544

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32631


File: python.info,  Node: C API<41>,  Prev: IDLE<23>,  Up: Python 3 10 0 alpha 5

1.24.45.12 C API
................

   - bpo-42979(1): When Python is built in debug mode (with C
     assertions), calling a type slot like ‘sq_length’ (‘__len__()’ in
     Python) now fails with a fatal error if the slot succeeded with an
     exception set, or failed with no exception set.  The error message
     contains the slot, the type name, and the current exception (if an
     exception is set).  Patch by Victor Stinner.

   - bpo-43030(2): Fixed a compiler warning in *note
     Py_UNICODE_ISSPACE(): 1cad. on platforms with signed ‘wchar_t’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42979

   (2) https://bugs.python.org/issue?@action=redirect&bpo=43030


File: python.info,  Node: Python 3 10 0 alpha 4,  Next: Python 3 10 0 alpha 3,  Prev: Python 3 10 0 alpha 5,  Up: Changelog

1.24.46 Python 3.10.0 alpha 4
-----------------------------

'Release date: 2021-01-04'

* Menu:

* Core and Builtins: Core and Builtins<123>.
* Library: Library<126>.
* Core and Builtins: Core and Builtins<124>.
* Library: Library<127>.
* Core and Builtins: Core and Builtins<125>.
* Library: Library<128>.
* Documentation: Documentation<40>.
* Tests: Tests<40>.
* Build: Build<47>.
* macOS: macOS<30>.
* Tools/Demos: Tools/Demos<28>.
* C API: C API<42>.


File: python.info,  Node: Core and Builtins<123>,  Next: Library<126>,  Up: Python 3 10 0 alpha 4

1.24.46.1 Core and Builtins
...........................

   - bpo-42814(1): Fix undefined behavior in
     ‘Objects/genericaliasobject.c’.

   - bpo-42806(2): Fix the column offsets for f-strings *note ast: 9.
     nodes surrounded by parentheses and for nodes that spawn multiple
     lines.  Patch by Pablo Galindo.

   - bpo-40631(3): Fix regression where a single parenthesized starred
     expression was a valid assignment target.

   - bpo-27794(4): Improve the error message for failed writes/deletes
     to property objects.  When possible, the attribute name is now
     shown.  Patch provided by Yurii Karabas.

   - bpo-42745(5): Make the type attribute lookup cache per-interpreter.
     Patch by Victor Stinner.

   - bpo-42246(6): Jumps to jumps are not eliminated when it would break
     PEP 626.

   - bpo-42246(7): Make sure that the ‘f_lasti’ and ‘f_lineno’
     attributes of a frame are set correctly when an exception is raised
     or re-raised.  Required for PEP 626.

   - bpo-32381(8): The coding cookie (ex: ‘# coding: latin1’) is now
     ignored in the command passed to the *note -c: 1a8. command line
     option.  Patch by Victor Stinner.

   - bpo-30858(9): Improve error location in expressions that contain
     assignments.  Patch by Pablo Galindo and Lysandros Nikolaou.

   - bpo-42615(10): Remove jump commands made redundant by the deletion
     of unreachable bytecode blocks

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42814

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42806

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40631

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27794

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42745

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42246

   (7) https://bugs.python.org/issue?@action=redirect&bpo=42246

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32381

   (9) https://bugs.python.org/issue?@action=redirect&bpo=30858

   (10) https://bugs.python.org/issue?@action=redirect&bpo=42615


File: python.info,  Node: Library<126>,  Next: Core and Builtins<124>,  Prev: Core and Builtins<123>,  Up: Python 3 10 0 alpha 4

1.24.46.2 Library
.................

   - bpo-42639(1): Make the *note atexit: d. module state
     per-interpreter.  It is now safe have more than one *note atexit:
     d. module instance.  Patch by Donghee Na and Victor Stinner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42639


File: python.info,  Node: Core and Builtins<124>,  Next: Library<127>,  Prev: Library<126>,  Up: Python 3 10 0 alpha 4

1.24.46.3 Core and Builtins
...........................

   - bpo-32381(1): Fix encoding name when running a ‘.pyc’ file on
     Windows: *note PyRun_SimpleFileExFlags(): 1cb2. now uses the
     correct encoding to decode the filename.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32381


File: python.info,  Node: Library<127>,  Next: Core and Builtins<125>,  Prev: Core and Builtins<124>,  Up: Python 3 10 0 alpha 4

1.24.46.4 Library
.................

   - bpo-42195(1): The ‘__args__’ of the parameterized generics for
     *note typing.Callable: 9ca. and *note collections.abc.Callable:
     9ed. are now consistent.  The ‘__args__’ for *note
     collections.abc.Callable: 9ed. are now flattened while *note
     typing.Callable: 9ca.’s have not changed.  To allow this change,
     *note types.GenericAlias: 9ee. can now be subclassed and
     ‘collections.abc.Callable’’s ‘__class_getitem__’ will now return a
     subclass of ‘types.GenericAlias’.  Tests for typing were also
     updated to not subclass things like ‘Callable[..., T]’ as that is
     not a valid base class.  Finally, both ‘Callable’s no longer
     validate their ‘argtypes’, in ‘Callable[[argtypes], resulttype]’ to
     prepare for PEP 612(2).  Patch by Ken Jin.

   - bpo-40137(3): Convert functools module to use *note
     PyType_FromModuleAndSpec(): 774.

   - bpo-40077(4): Convert *note array: 8. to use heap types, and
     establish module state for these.

   - bpo-42008(5): Fix _random.Random() seeding.

   - bpo-1635741(6): Port the ‘pyexpat’ extension module to multi-phase
     initialization ( PEP 489(7)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42195

   (2) https://peps.python.org/pep-0612/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40137

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40077

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42008

   (6) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (7) https://peps.python.org/pep-0489/


File: python.info,  Node: Core and Builtins<125>,  Next: Library<128>,  Prev: Library<127>,  Up: Python 3 10 0 alpha 4

1.24.46.5 Core and Builtins
...........................

   - bpo-40521(1): Make the Unicode dictionary of interned strings
     compatible with subinterpreters.  Patch by Victor Stinner.

   - bpo-39465(2): Make ‘_PyUnicode_FromId()’ function compatible with
     subinterpreters.  Each interpreter now has an array of identifier
     objects (interned strings decoded from UTF-8).  Patch by Victor
     Stinner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40521

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39465


File: python.info,  Node: Library<128>,  Next: Documentation<40>,  Prev: Core and Builtins<125>,  Up: Python 3 10 0 alpha 4

1.24.46.6 Library
.................

   - bpo-42257(1): Handle empty string in variable executable in
     platform.libc_ver()

   - bpo-42772(2): randrange() now raises a TypeError when step is
     specified without a stop argument.  Formerly, it silently ignored
     the step argument.

   - bpo-42759(3): Fixed equality comparison of ‘tkinter.Variable’ and
     *note tkinter.font.Font: 1cb6.  Objects which belong to different
     Tcl interpreters are now always different, even if they have the
     same name.

   - bpo-42756(4): Configure LMTP Unix-domain socket to use socket
     global default timeout when a timeout is not explicitly provided.

   - bpo-23328(5): Allow / character in username, password fields on
     _PROXY envars.

   - bpo-42740(6): *note typing.get_args(): 2ac. and *note
     typing.get_origin(): 2ab. now support PEP 604(7) union types and
     PEP 612(8) additions to ‘Callable’.

   - bpo-42655(9): *note subprocess: dc. 'extra_groups' is now correctly
     passed into setgroups() system call.

   - bpo-42727(10): ‘EnumMeta.__prepare__’ now accepts ‘**kwds’ to
     properly support ‘__init_subclass__’

   - bpo-38308(11): Add optional 'weights' to
     'statistics.harmonic_mean()'.

   - bpo-42721(12): When simple query dialogs (*note
     tkinter.simpledialog: fe.), message boxes (*note
     tkinter.messagebox: fc.) or color choose dialog (*note
     tkinter.colorchooser: f7.) are created without arguments 'master'
     and 'parent', and the default root window is not yet created, and
     ‘NoDefaultRoot()’ was not called, a new temporal hidden root window
     will be created automatically.  It will not be set as the default
     root window and will be destroyed right after closing the dialog
     window.  It will help to use these simple dialog windows in
     programs which do not need other GUI.

   - bpo-25246(13): Optimized *note collections.deque.remove(): 1cb7.

   - bpo-35728(14): Added a root parameter to *note
     tkinter.font.nametofont(): 1cb8.

   - bpo-15303(15): *note tkinter: f6. supports now widgets with boolean
     value False.

   - bpo-42681(16): Fixed range checks for color and pair numbers in
     *note curses: 2f.

   - bpo-42685(17): Improved placing of simple query windows in Tkinter
     (such as *note tkinter.simpledialog.askinteger(): 1cb9.).  They are
     now centered at the center of the parent window if it is specified
     and shown, otherwise at the center of the screen.

   - bpo-9694(18): Argparse help no longer uses the confusing phrase,
     «optional arguments».  It uses «options» instead.

   - bpo-1635741(19): Port the ‘_thread’ extension module to the
     multiphase initialization API ( PEP 489(20)) and convert its static
     types to heap types.

   - bpo-37961(21): Fix crash in ‘tracemalloc.Traceback.__repr__()’
     (regressed in Python 3.9).

   - bpo-42630(22): *note tkinter: f6. functions and constructors which
     need a default root window raise now *note RuntimeError: 244. with
     descriptive message instead of obscure *note AttributeError: 5f0.
     or *note NameError: 452. if it is not created yet or cannot be
     created automatically.

   - bpo-42639(23): ‘atexit._run_exitfuncs()’ now logs callback
     exceptions using *note sys.unraisablehook: 508, rather than logging
     them directly into *note sys.stderr: b35. and raise the last
     exception.

   - bpo-42644(24): ‘logging.disable’ will now validate the types and
     value of its parameter.  It also now accepts strings representing
     the levels (as does ‘logging.setLevel’) instead of only the
     numerical values.

   - bpo-42639(25): At Python exit, if a callback registered with *note
     atexit.register(): a80. fails, its exception is now logged.
     Previously, only some exceptions were logged, and the last
     exception was always silently ignored.

   - bpo-36541(26): Fixed lib2to3.pgen2 to be able to parse PEP-570
     positional only argument syntax.

   - bpo-42382(27): In ‘importlib.metadata’: - ‘EntryPoint’ objects now
     expose a ‘.dist’ object referencing the ‘Distribution’ when
     constructed from a ‘Distribution’.  - Add support for package
     discovery under package normalization rules.  - The object returned
     by ‘metadata()’ now has a formally defined protocol called
     ‘PackageMetadata’ with declared support for the ‘.get_all()’
     method.  - Synced with importlib_metadata 3.3.

   - bpo-41877(28): A check is added against misspellings of autospect,
     auto_spec and set_spec being passed as arguments to patch,
     patch.object and create_autospec.

   - bpo-39717(29): [tarfile] update nested exception raising to use
     ‘from None’ or ‘from e’

   - bpo-41877(30): AttributeError for suspected misspellings of
     assertions on mocks are now pointing out that the cause are
     misspelled assertions and also what to do if the misspelling is
     actually an intended attribute name.  The unittest.mock document is
     also updated to reflect the current set of recognised misspellings.

   - bpo-41559(31): Implemented PEP 612(32): added ‘ParamSpec’ and
     ‘Concatenate’ to *note typing: 10a.  Patch by Ken Jin.

   - bpo-42385(33): StrEnum: fix _generate_next_value_ to return a str

   - bpo-31904(34): Define THREAD_STACK_SIZE for VxWorks.

   - bpo-34750(35): [Enum] ‘_EnumDict.update()’ is now supported.

   - bpo-42517(36): Enum: private names do not become members / do not
     generate errors – they remain normal attributes

   - bpo-42678(37): ‘Enum’: call ‘__init_subclass__’ after members have
     been added

   - bpo-28964(38): *note ast.literal_eval(): e14. adds line number
     information (if available) in error message for malformed nodes.

   - bpo-42470(39): *note random.sample(): 94e. no longer warns on a
     sequence which is also a set.

   - bpo-31904(40): ‘posixpath.expanduser()’ returns the input 'path'
     unchanged if user home directory is None on VxWorks.

   - bpo-42388(41): Fix subprocess.check_output(…, input=None) behavior
     when text=True to be consistent with that of the documentation and
     universal_newlines=True.

   - bpo-34463(42): Fixed discrepancy between *note traceback: 104. and
     the interpreter in formatting of SyntaxError with lineno not set
     (*note traceback: 104. was changed to match interpreter).

   - bpo-42393(43): Raise *note OverflowError: a83. instead of silent
     truncation in *note socket.ntohs(): a82. and *note socket.htons():
     a81.  Silent truncation was deprecated in Python 3.7.  Patch by
     Erlend E. Aasland

   - bpo-42222(44): Harmonized *note random.randrange(): a6d. argument
     handling to match *note range(): b3f.

        * The integer test and conversion in ‘randrange()’ now uses
          *note operator.index(): 1cba.

        * Non-integer arguments to ‘randrange()’ are deprecated.

        * The ‘ValueError’ is deprecated in favor of a ‘TypeError’.

        * It now runs a little faster than before.

     (Contributed by Raymond Hettinger and Serhiy Storchaka.)

   - bpo-42163(45): Restore compatibility for ‘uname_result’ around
     deepcopy and _replace.

   - bpo-42090(46): ‘zipfile.Path.joinpath’ now accepts arbitrary
     arguments, same as ‘pathlib.Path.joinpath’.

   - bpo-1635741(47): Port the _csv module to the multi-phase
     initialization API ( PEP 489(48)).

   - bpo-42059(49): *note typing.TypedDict: 332. types created using the
     alternative call-style syntax now correctly respect the ‘total’
     keyword argument when setting their ‘__required_keys__’ and
     ‘__optional_keys__’ class attributes.

   - bpo-41960(50): Add ‘globalns’ and ‘localns’ parameters to the *note
     inspect.signature(): 22f. and *note
     inspect.Signature.from_callable(): 943.

   - bpo-41907(51): fix ‘format()’ behavior for ‘IntFlag’

   - bpo-41891(52): Ensure asyncio.wait_for waits for task completion

   - bpo-24792(53): Fixed bug where ‘zipimporter’ sometimes reports an
     incorrect cause of import errors.

   - bpo-31904(54): Fix site and sysconfig modules for VxWorks RTOS
     which has no home directories.

   - bpo-41462(55): Add *note os.set_blocking(): 103c. support for
     VxWorks RTOS.

   - bpo-40219(56): Lowered ‘tkinter.ttk.LabeledScale’ dummy widget to
     prevent hiding part of the content label.

   - bpo-37193(57): Fixed memory leak in ‘socketserver.ThreadingMixIn’
     introduced in Python 3.7.

   - bpo-39068(58): Fix initialization race condition in ‘a85encode()’
     and ‘b85encode()’ in *note base64: f.  Patch by Brandon Stansbury.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42257

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42772

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42759

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42756

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23328

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42740

   (7) https://peps.python.org/pep-0604/

   (8) https://peps.python.org/pep-0612/

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42655

   (10) https://bugs.python.org/issue?@action=redirect&bpo=42727

   (11) https://bugs.python.org/issue?@action=redirect&bpo=38308

   (12) https://bugs.python.org/issue?@action=redirect&bpo=42721

   (13) https://bugs.python.org/issue?@action=redirect&bpo=25246

   (14) https://bugs.python.org/issue?@action=redirect&bpo=35728

   (15) https://bugs.python.org/issue?@action=redirect&bpo=15303

   (16) https://bugs.python.org/issue?@action=redirect&bpo=42681

   (17) https://bugs.python.org/issue?@action=redirect&bpo=42685

   (18) https://bugs.python.org/issue?@action=redirect&bpo=9694

   (19) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (20) https://peps.python.org/pep-0489/

   (21) https://bugs.python.org/issue?@action=redirect&bpo=37961

   (22) https://bugs.python.org/issue?@action=redirect&bpo=42630

   (23) https://bugs.python.org/issue?@action=redirect&bpo=42639

   (24) https://bugs.python.org/issue?@action=redirect&bpo=42644

   (25) https://bugs.python.org/issue?@action=redirect&bpo=42639

   (26) https://bugs.python.org/issue?@action=redirect&bpo=36541

   (27) https://bugs.python.org/issue?@action=redirect&bpo=42382

   (28) https://bugs.python.org/issue?@action=redirect&bpo=41877

   (29) https://bugs.python.org/issue?@action=redirect&bpo=39717

   (30) https://bugs.python.org/issue?@action=redirect&bpo=41877

   (31) https://bugs.python.org/issue?@action=redirect&bpo=41559

   (32) https://peps.python.org/pep-0612/

   (33) https://bugs.python.org/issue?@action=redirect&bpo=42385

   (34) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (35) https://bugs.python.org/issue?@action=redirect&bpo=34750

   (36) https://bugs.python.org/issue?@action=redirect&bpo=42517

   (37) https://bugs.python.org/issue?@action=redirect&bpo=42678

   (38) https://bugs.python.org/issue?@action=redirect&bpo=28964

   (39) https://bugs.python.org/issue?@action=redirect&bpo=42470

   (40) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (41) https://bugs.python.org/issue?@action=redirect&bpo=42388

   (42) https://bugs.python.org/issue?@action=redirect&bpo=34463

   (43) https://bugs.python.org/issue?@action=redirect&bpo=42393

   (44) https://bugs.python.org/issue?@action=redirect&bpo=42222

   (45) https://bugs.python.org/issue?@action=redirect&bpo=42163

   (46) https://bugs.python.org/issue?@action=redirect&bpo=42090

   (47) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (48) https://peps.python.org/pep-0489/

   (49) https://bugs.python.org/issue?@action=redirect&bpo=42059

   (50) https://bugs.python.org/issue?@action=redirect&bpo=41960

   (51) https://bugs.python.org/issue?@action=redirect&bpo=41907

   (52) https://bugs.python.org/issue?@action=redirect&bpo=41891

   (53) https://bugs.python.org/issue?@action=redirect&bpo=24792

   (54) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (55) https://bugs.python.org/issue?@action=redirect&bpo=41462

   (56) https://bugs.python.org/issue?@action=redirect&bpo=40219

   (57) https://bugs.python.org/issue?@action=redirect&bpo=37193

   (58) https://bugs.python.org/issue?@action=redirect&bpo=39068


File: python.info,  Node: Documentation<40>,  Next: Tests<40>,  Prev: Library<128>,  Up: Python 3 10 0 alpha 4

1.24.46.7 Documentation
.......................

   - bpo-17140(1): Add documentation for the *note
     multiprocessing.pool.ThreadPool: 1cbc. class.

   - bpo-34398(2): Prominently feature listings from the glossary in
     documentation search results.  Patch by Ammar Askar.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17140

   (2) https://bugs.python.org/issue?@action=redirect&bpo=34398


File: python.info,  Node: Tests<40>,  Next: Build<47>,  Prev: Documentation<40>,  Up: Python 3 10 0 alpha 4

1.24.46.8 Tests
...............

   - bpo-42794(1): Update test_nntplib to use official group name of
     news.aioe.org for testing.  Patch by Donghee Na.

   - bpo-31904(2): Skip some asyncio tests on VxWorks.

   - bpo-42641(3): Enhance ‘test_select.test_select()’: it now takes 500
     milliseconds rather than 10 seconds.  Use Python rather than a
     shell to make the test more portable.

   - bpo-31904(4): Skip some tests in _test_all_chown_common() on
     VxWorks.

   - bpo-42199(5): Fix bytecode helper assertNotInBytecode.

   - bpo-41443(6): Add more attribute checking in test_posix.py

   - bpo-31904(7): Disable os.popen and impacted tests on VxWorks

   - bpo-41439(8): Port test_ssl and test_uuid to VxWorks RTOS.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42794

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42641

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42199

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41443

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (8) https://bugs.python.org/issue?@action=redirect&bpo=41439


File: python.info,  Node: Build<47>,  Next: macOS<30>,  Prev: Tests<40>,  Up: Python 3 10 0 alpha 4

1.24.46.9 Build
...............

   - bpo-42692(1): Fix __builtin_available check on older compilers.
     Patch by Joshua Root.

   - bpo-27640(2): Added ‘--disable-test-modules’ option to the
     ‘configure’ script: don’t build nor install test modules.  Patch by
     Xavier de Gaye, Thomas Petazzoni and Peixing Xin.

   - bpo-42604(3): Now all platforms use a value for the «EXT_SUFFIX»
     build variable derived from SOABI (for instance in freeBSD,
     «EXT_SUFFIX» is now «.cpython-310d.so» instead of «.so»).
     Previously only Linux, Mac and VxWorks were using a value for
     «EXT_SUFFIX» that included «SOABI».

   - bpo-42598(4): Fix implicit function declarations in configure which
     could have resulted in incorrect configuration checks.  Patch
     contributed by Joshua Root.

   - bpo-31904(5): Enable libpython3.so for VxWorks.

   - bpo-29076(6): Add fish shell support to macOS installer.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42692

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27640

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42604

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42598

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (6) https://bugs.python.org/issue?@action=redirect&bpo=29076


File: python.info,  Node: macOS<30>,  Next: Tools/Demos<28>,  Prev: Build<47>,  Up: Python 3 10 0 alpha 4

1.24.46.10 macOS
................

   - bpo-42361(1): Update macOS installer build to use Tcl/Tk 8.6.11
     (rc2, expected to be final release).

   - bpo-41837(2): Update macOS installer build to use OpenSSL 1.1.1i.

   - bpo-42584(3): Update macOS installer to use SQLite 3.34.0.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42361

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41837

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42584


File: python.info,  Node: Tools/Demos<28>,  Next: C API<42>,  Prev: macOS<30>,  Up: Python 3 10 0 alpha 4

1.24.46.11 Tools/Demos
......................

   - bpo-42726(1): Fixed Python 3 compatibility issue with
     gdb/libpython.py handling of attribute dictionaries.

   - bpo-42613(2): Fix ‘freeze.py’ tool to use the prope config and
     library directories.  Patch by Victor Stinner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42726

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42613


File: python.info,  Node: C API<42>,  Prev: Tools/Demos<28>,  Up: Python 3 10 0 alpha 4

1.24.46.12 C API
................

   - bpo-42591(1): Export the ‘Py_FrozenMain()’ function: fix a Python
     3.9.0 regression.  Python 3.9 uses ‘-fvisibility=hidden’ and the
     function was not exported explicitly and so not exported.

   - bpo-32381(2): Remove the private ‘_Py_fopen()’ function which is no
     longer needed.  Use ‘_Py_wfopen()’ or ‘_Py_fopen_obj()’ instead.
     Patch by Victor Stinner.

   - bpo-1635741(3): Port *note resource: c1. extension module to module
     state

   - bpo-42111(4): Update the ‘xxlimited’ module to be a better example
     of how to use the limited C API.

   - bpo-40052(5): Fix an alignment build warning/error in function
     ‘PyVectorcall_Function()’.  Patch by Andreas Schneider, Antoine
     Pitrou and Petr Viktorin.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42591

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32381

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42111

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40052


File: python.info,  Node: Python 3 10 0 alpha 3,  Next: Python 3 10 0 alpha 2,  Prev: Python 3 10 0 alpha 4,  Up: Changelog

1.24.47 Python 3.10.0 alpha 3
-----------------------------

'Release date: 2020-12-07'

* Menu:

* Security: Security<34>.
* Core and Builtins: Core and Builtins<126>.
* Library: Library<129>.
* Core and Builtins: Core and Builtins<127>.
* Library: Library<130>.
* Core and Builtins: Core and Builtins<128>.
* Library: Library<131>.
* Core and Builtins: Core and Builtins<129>.
* Library: Library<132>.
* Documentation: Documentation<41>.
* Tests: Tests<41>.
* Build: Build<48>.
* Windows: Windows<41>.
* macOS: macOS<31>.
* IDLE: IDLE<24>.
* Tools/Demos: Tools/Demos<29>.
* C API: C API<43>.


File: python.info,  Node: Security<34>,  Next: Core and Builtins<126>,  Up: Python 3 10 0 alpha 3

1.24.47.1 Security
..................

   - bpo-40791(1): Add ‘volatile’ to the accumulator variable in
     ‘hmac.compare_digest’, making constant-time-defeating optimizations
     less likely.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40791


File: python.info,  Node: Core and Builtins<126>,  Next: Library<129>,  Prev: Security<34>,  Up: Python 3 10 0 alpha 3

1.24.47.2 Core and Builtins
...........................

   - bpo-42576(1): ‘types.GenericAlias’ will now raise a ‘TypeError’
     when attempting to initialize with a keyword argument.  Previously,
     this would cause the interpreter to crash if the interpreter was
     compiled with debug symbols.  This does not affect interpreters
     compiled for release.  Patch by Ken Jin.

   - bpo-42536(2): Several built-in and standard library types now
     ensure that their internal result tuples are always tracked by the
     *note garbage collector: 17c0.:

        - *note collections.OrderedDict.items(): 7f4.

        - *note dict.items(): 9d4.

        - *note enumerate(): 1688.

        - *note functools.reduce(): 21a.

        - *note itertools.combinations(): 1519.

        - *note itertools.combinations_with_replacement(): 1489.

        - *note itertools.permutations(): 1cc5.

        - *note itertools.product(): 151a.

        - *note itertools.zip_longest(): 14a6.

        - *note zip(): 1a0.

     Previously, they could have become untracked by a prior garbage
     collection.  Patch by Brandt Bucher.

   - bpo-42500(3): Improve handling of exceptions near recursion limit.
     Converts a number of Fatal Errors in RecursionErrors.

   - bpo-42246(4): PEP 626: After a return, the f_lineno attribute of a
     frame is always the last line executed.

   - bpo-42435(5): Speed up comparison of bytes objects with non-bytes
     objects when option *note -b: 7fa. is specified.  Speed up
     comparison of bytarray objects with non-buffer object.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42576

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42536

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42500

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42246

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42435


File: python.info,  Node: Library<129>,  Next: Core and Builtins<127>,  Prev: Core and Builtins<126>,  Up: Python 3 10 0 alpha 3

1.24.47.3 Library
.................

   - bpo-1635741(1): Port the ‘_warnings’ extension module to the
     multi-phase initialization API ( PEP 489(2)).  Patch by Victor
     Stinner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (2) https://peps.python.org/pep-0489/


File: python.info,  Node: Core and Builtins<127>,  Next: Library<130>,  Prev: Library<129>,  Up: Python 3 10 0 alpha 3

1.24.47.4 Core and Builtins
...........................

   - bpo-41686(1): On Windows, the ‘SIGINT’ event,
     ‘_PyOS_SigintEvent()’, is now created even if Python is configured
     to not install signal handlers (if *note
     PyConfig.install_signal_handlers: abd. equals to 0, or
     ‘Py_InitializeEx(0)’).

   - bpo-42381(2): Allow assignment expressions in set literals and set
     comprehensions as per PEP 572.  Patch by Pablo Galindo.

   - bpo-42202(3): Change function parameters annotations internal
     representation to tuple of strings.  Patch provided by Yurii
     Karabas.

   - bpo-42374(4): Fix a regression introduced by the new parser, where
     an unparenthesized walrus operator was not allowed within generator
     expressions.

   - bpo-42316(5): Allow an unparenthesized walrus in subscript indexes.

   - bpo-42349(6): Make sure that the compiler front-end produces a
     well-formed control flow graph.  Be more aggressive in the compiler
     back-end, as it is now safe to do so.

   - bpo-42296(7): On Windows, fix a regression in signal handling which
     prevented to interrupt a program using CTRL+C. The signal handler
     can be run in a thread different than the Python thread, in which
     case the test deciding if the thread can handle signals is wrong.

   - bpo-42332(8): *note types.GenericAlias: 9ee. objects can now be the
     targets of weakrefs.

   - bpo-42282(9): Optimise constant subexpressions that appear as part
     of named expressions (previously the AST optimiser did not descend
     into named expressions).  Patch by Nick Coghlan.

   - bpo-42266(10): Fixed a bug with the LOAD_ATTR opcode cache that was
     not respecting monkey-patching a class-level attribute to make it a
     descriptor.  Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41686

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42381

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42202

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42374

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42316

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42349

   (7) https://bugs.python.org/issue?@action=redirect&bpo=42296

   (8) https://bugs.python.org/issue?@action=redirect&bpo=42332

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42282

   (10) https://bugs.python.org/issue?@action=redirect&bpo=42266


File: python.info,  Node: Library<130>,  Next: Core and Builtins<128>,  Prev: Core and Builtins<127>,  Up: Python 3 10 0 alpha 3

1.24.47.5 Library
.................

   - bpo-40077(1): Convert *note queue: bb. to use heap types.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40077


File: python.info,  Node: Core and Builtins<128>,  Next: Library<131>,  Prev: Library<130>,  Up: Python 3 10 0 alpha 3

1.24.47.6 Core and Builtins
...........................

   - bpo-42246(1): Improved accuracy of line tracing events and f_lineno
     attribute of Frame objects.  See PEP 626 for details.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42246


File: python.info,  Node: Library<131>,  Next: Core and Builtins<129>,  Prev: Core and Builtins<128>,  Up: Python 3 10 0 alpha 3

1.24.47.7 Library
.................

   - bpo-40077(1): Convert *note mmap: 94. to use heap types.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40077


File: python.info,  Node: Core and Builtins<129>,  Next: Library<132>,  Prev: Library<131>,  Up: Python 3 10 0 alpha 3

1.24.47.8 Core and Builtins
...........................

   - bpo-42233(1): Allow ‘GenericAlias’ objects to use *note union type
     expressions: 9c7.  This allows expressions like ‘list[int] |
     dict[float, str]’ where previously a ‘TypeError’ would have been
     thrown.  This also fixes union type expressions not de-duplicating
     ‘GenericAlias’ objects.  (Contributed by Ken Jin in bpo-42233(2).)

   - bpo-26131(3): The import system triggers a ‘ImportWarning’ when it
     falls back to using ‘load_module()’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42233

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42233

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26131


File: python.info,  Node: Library<132>,  Next: Documentation<41>,  Prev: Core and Builtins<129>,  Up: Python 3 10 0 alpha 3

1.24.47.9 Library
.................

   - bpo-5054(1): CGIHTTPRequestHandler.run_cgi() HTTP_ACCEPT improperly
     parsed.  Replace the special purpose getallmatchingheaders with
     generic get_all method and add relevant tests.

     Original Patch by Martin Panter.  Modified by Senthil Kumaran.

   - bpo-42562(2): Fix issue when dis failed to parse function that has
     no line numbers.  Patch provided by Yurii Karabas.

   - bpo-17735(3): ‘inspect.findsource()’ now raises *note OSError: 2c0.
     instead of *note IndexError: 173c. when ‘co_lineno’ of a code
     object is greater than the file length.  This can happen, for
     example, when a file is edited after it was imported.  PR by Irit
     Katriel.

   - bpo-42116(4): Fix handling of trailing comments by *note
     inspect.getsource(): 17ab.

   - bpo-42532(5): Remove unexpected call of ‘__bool__’ when passing a
     ‘spec_arg’ argument to a Mock.

   - bpo-38200(6): Added itertools.pairwise()

   - bpo-41818(7): Fix test_master_read() so that it succeeds on all
     platforms that either raise OSError or return b»» upon reading from
     master.

   - bpo-42487(8): ChainMap.__iter__ no longer calls __getitem__ on
     underlying maps

   - bpo-42482(9): *note TracebackException: 563. no longer holds a
     reference to the exception’s traceback object.  Consequently,
     instances of TracebackException for equivalent but non-equal
     exceptions now compare as equal.

   - bpo-41818(10): Make test_openpty() avoid unexpected success due to
     number of rows and/or number of columns being == 0.

   - bpo-42392(11): Remove loop parameter from ‘asyncio.subprocess’ and
     ‘asyncio.tasks’ functions.  Patch provided by Yurii Karabas.

   - bpo-42392(12): Remove loop parameter from ‘asyncio.open_connection’
     and ‘asyncio.start_server’ functions.  Patch provided by Yurii
     Karabas.

   - bpo-28468(13): Add *note platform.freedesktop_os_release(): a29.
     function to parse freedesktop.org ‘os-release’ files.

   - bpo-42299(14): Removed the ‘formatter’ module, which was deprecated
     in Python 3.4.  It is somewhat obsolete, little used, and not
     tested.  It was originally scheduled to be removed in Python 3.6,
     but such removals were delayed until after Python 2.7 EOL. Existing
     users should copy whatever classes they use into their code.  Patch
     by Donghee Na and and Terry J. Reedy.

   - bpo-26131(15): Deprecate zipimport.zipimporter.load_module() in
     favour of exec_module().

   - bpo-41818(16): Updated tests for the pty library.  test_basic() has
     been changed to test_openpty(); this additionally checks if slave
     termios and slave winsize are being set properly by pty.openpty().
     In order to add support for FreeBSD, NetBSD, OpenBSD, and Darwin,
     this also adds test_master_read(), which demonstrates that
     pty.spawn() should not depend on an OSError to exit from its copy
     loop.

   - bpo-42392(17): Remove loop parameter from ‘__init__’ in all
     ‘asyncio.locks’ and ‘asyncio.Queue’ classes.  Patch provided by
     Yurii Karabas.

   - bpo-15450(18): Make *note filecmp.dircmp: 1142. respect
     subclassing.  Now the *note filecmp.dircmp.subdirs: 1ccd. behaves
     as expected when subclassing dircmp.

   - bpo-42413(19): The exception *note socket.timeout: a37. is now an
     alias of *note TimeoutError: a38.

   - bpo-31904(20): Support signal module on VxWorks.

   - bpo-42406(21): We fixed an issue in ‘pickle.whichmodule’ in which
     importing ‘multiprocessing’ could change the how pickle identifies
     which module an object belongs to, potentially breaking the
     unpickling of those objects.

   - bpo-42403(22): Simplify the *note importlib: 7b. external bootstrap
     code: ‘importlib._bootstrap_external’ now uses regular imports to
     import builtin modules.  When it is imported, the builtin *note
     __import__(): ad3. function is already fully working and so can be
     used to import builtin modules like *note sys: df.  Patch by Victor
     Stinner.

   - bpo-1635741(23): Convert _sre module types to heap types (PEP 384).
     Patch by Erlend E. Aasland.

   - bpo-42375(24): subprocess module update for DragonFlyBSD support.

   - bpo-41713(25): Port the ‘_signal’ extension module to the
     multi-phase initialization API ( PEP 489(26)).  Patch by Victor
     Stinner and Mohamed Koubaa.

   - bpo-37205(27): *note time.time(): 55d, *note time.perf_counter():
     c7c. and *note time.monotonic(): 55c. functions can no longer fail
     with a Python fatal error, instead raise a regular Python exception
     on failure.

   - bpo-42328(28): Fixed *note tkinter.ttk.Style.map(): 1cce.  The
     function accepts now the representation of the default state as
     empty sequence (as returned by ‘Style.map()’).  The structure of
     the result is now the same on all platform and does not depend on
     the value of ‘wantobjects’.

   - bpo-42345(29): Fix various issues with ‘typing.Literal’ parameter
     handling (flatten, deduplicate, use type to cache key).  Patch
     provided by Yurii Karabas.

   - bpo-37205(30): *note time.perf_counter(): c7c. on Windows and *note
     time.monotonic(): 55c. on macOS are now system-wide.  Previously,
     they used an offset computed at startup to reduce the precision
     loss caused by the float type.  Use *note time.perf_counter_ns():
     ce0. and *note time.monotonic_ns(): cdf. added in Python 3.7 to
     avoid this precision loss.

   - bpo-42318(31): Fixed support of non-BMP characters in *note
     tkinter: f6. on macOS.

   - bpo-42350(32): Fix the *note threading.Thread: 176. class at fork:
     do nothing if the thread is already stopped (ex: fork called at
     Python exit).  Previously, an error was logged in the child
     process.

   - bpo-42333(33): Port _ssl extension module to heap types.

   - bpo-42014(34): The ‘onerror’ callback from ‘shutil.rmtree’ now
     receives correct function when ‘os.open’ fails.

   - bpo-42237(35): Fix ‘os.sendfile()’ on illumos.

   - bpo-42308(36): Add *note threading.__excepthook__: a4c. to allow
     retrieving the original value of *note threading.excepthook(): a4d.
     in case it is set to a broken or a different value.  Patch by Mario
     Corchero.

   - bpo-42131(37): Implement PEP 451/spec methods on
     zipimport.zipimporter: find_spec(), create_module(), and
     exec_module().

     This also allows for the documented deprecation of find_loader(),
     find_module(), and load_module().

   - bpo-41877(38): Mock objects which are not unsafe will now raise an
     AttributeError if an attribute with the prefix asert, aseert, or
     assrt is accessed, in addition to this already happening for the
     prefixes assert or assret.

   - bpo-42264(39): ‘sqlite3.OptimizedUnicode’ has been undocumented and
     obsolete since Python 3.3, when it was made an alias to *note str:
     169.  It is now deprecated, scheduled for removal in Python 3.12.

   - bpo-42251(40): Added *note threading.gettrace(): a48. and *note
     threading.getprofile(): a49. to retrieve the functions set by *note
     threading.settrace(): a4a. and *note threading.setprofile(): a4b.
     respectively.  Patch by Mario Corchero.

   - bpo-42249(41): Fixed writing binary Plist files larger than 4 GiB.

   - bpo-42236(42): On Unix, the *note os.device_encoding(): 1c1d.
     function now returns ‘'UTF-8'’ rather than the device encoding if
     the *note Python UTF-8 Mode: 867. is enabled.

   - bpo-41754(43): webbrowser: Ignore 'NotADirectoryError' when calling
     ‘xdg-settings’.

   - bpo-42183(44): Fix a stack overflow error for asyncio Task or
     Future repr().

     The overflow occurs under some circumstances when a Task or Future
     recursively returns itself.

   - bpo-42140(45): Improve asyncio.wait function to create the futures
     set just one time.

   - bpo-42133(46): Update various modules in the stdlib to fall back on
     ‘__spec__.loader’ when ‘__loader__’ isn’t defined on a module.

   - bpo-26131(47): The ‘load_module()’ methods found in ‘importlib’ now
     trigger a ‘DeprecationWarning’.

   - bpo-39825(48): Windows: Change
     ‘sysconfig.get_config_var('EXT_SUFFIX')’ to the expected full
     ‘platform_tag.extension’ format.  Previously it was hard-coded to
     ‘.pyd’, now it is compatible with ‘distutils.sysconfig’ and will
     result in something like ‘.cp38-win_amd64.pyd’.  This brings
     windows into conformance with the other platforms.

   - bpo-26389(49): The *note traceback.format_exception(): a4f, *note
     traceback.format_exception_only(): a50, and *note
     traceback.print_exception(): a51. functions can now take an
     exception object as a positional-only argument.

   - bpo-41889(50): Enum: fix regression involving inheriting a multiply
     inherited enum

   - bpo-41861(51): Convert *note sqlite3: d4. to use heap types (PEP
     384).  Patch by Erlend E. Aasland.

   - bpo-40624(52): Added support for the XPath ‘!=’ operator in
     xml.etree

   - bpo-28850(53): Fix *note pprint.PrettyPrinter.format(): 1ccf.
     overrides being ignored for contents of small containers.  The
     ‘pprint._safe_repr()’ function was removed.

   - bpo-41625(54): Expose the ‘splice()’ as *note os.splice(): a1c. in
     the *note os: a5. module.  Patch by Pablo Galindo

   - bpo-34215(55): Clarify the error message for *note
     asyncio.IncompleteReadError: 1cd0. when ‘expected’ is ‘None’.

   - bpo-41543(56): Add async context manager support for
     contextlib.nullcontext.

   - bpo-21041(57): *note pathlib.PurePath.parents: a23. now supports
     negative indexing.  Patch contributed by Yaroslav Pankovych.

   - bpo-41332(58): Added missing connect_accepted_socket() method to
     ‘asyncio.AbstractEventLoop’.

   - bpo-12800(59): Extracting a symlink from a tarball should succeed
     and overwrite the symlink if it already exists.  The fix is to
     remove the existing file or symlink before extraction.  Based on
     patch by Chris AtLee, Jeffrey Kintscher, and Senthil Kumaran.

   - bpo-40968(60): *note urllib.request: 111. and *note http.client:
     73. now send ‘http/1.1’ ALPN extension during TLS handshake when no
     custom context is supplied.

   - bpo-41001(61): Add *note os.eventfd(): a1b. to provide a low level
     interface for Linux’s event notification file descriptor.

   - bpo-40816(62): Add AsyncContextDecorator to contextlib to support
     async context manager as a decorator.

   - bpo-40550(63): Fix time-of-check/time-of-action issue in
     subprocess.Popen.send_signal.

   - bpo-39411(64): Add an ‘is_async’ identifier to *note pyclbr: b9.’s
     ‘Function’ objects.  Patch by Batuhan Taskaya

   - bpo-35498(65): Add slice support to *note pathlib.PurePath.parents:
     a23.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5054

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42562

   (3) https://bugs.python.org/issue?@action=redirect&bpo=17735

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42116

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42532

   (6) https://bugs.python.org/issue?@action=redirect&bpo=38200

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41818

   (8) https://bugs.python.org/issue?@action=redirect&bpo=42487

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42482

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41818

   (11) https://bugs.python.org/issue?@action=redirect&bpo=42392

   (12) https://bugs.python.org/issue?@action=redirect&bpo=42392

   (13) https://bugs.python.org/issue?@action=redirect&bpo=28468

   (14) https://bugs.python.org/issue?@action=redirect&bpo=42299

   (15) https://bugs.python.org/issue?@action=redirect&bpo=26131

   (16) https://bugs.python.org/issue?@action=redirect&bpo=41818

   (17) https://bugs.python.org/issue?@action=redirect&bpo=42392

   (18) https://bugs.python.org/issue?@action=redirect&bpo=15450

   (19) https://bugs.python.org/issue?@action=redirect&bpo=42413

   (20) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (21) https://bugs.python.org/issue?@action=redirect&bpo=42406

   (22) https://bugs.python.org/issue?@action=redirect&bpo=42403

   (23) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (24) https://bugs.python.org/issue?@action=redirect&bpo=42375

   (25) https://bugs.python.org/issue?@action=redirect&bpo=41713

   (26) https://peps.python.org/pep-0489/

   (27) https://bugs.python.org/issue?@action=redirect&bpo=37205

   (28) https://bugs.python.org/issue?@action=redirect&bpo=42328

   (29) https://bugs.python.org/issue?@action=redirect&bpo=42345

   (30) https://bugs.python.org/issue?@action=redirect&bpo=37205

   (31) https://bugs.python.org/issue?@action=redirect&bpo=42318

   (32) https://bugs.python.org/issue?@action=redirect&bpo=42350

   (33) https://bugs.python.org/issue?@action=redirect&bpo=42333

   (34) https://bugs.python.org/issue?@action=redirect&bpo=42014

   (35) https://bugs.python.org/issue?@action=redirect&bpo=42237

   (36) https://bugs.python.org/issue?@action=redirect&bpo=42308

   (37) https://bugs.python.org/issue?@action=redirect&bpo=42131

   (38) https://bugs.python.org/issue?@action=redirect&bpo=41877

   (39) https://bugs.python.org/issue?@action=redirect&bpo=42264

   (40) https://bugs.python.org/issue?@action=redirect&bpo=42251

   (41) https://bugs.python.org/issue?@action=redirect&bpo=42249

   (42) https://bugs.python.org/issue?@action=redirect&bpo=42236

   (43) https://bugs.python.org/issue?@action=redirect&bpo=41754

   (44) https://bugs.python.org/issue?@action=redirect&bpo=42183

   (45) https://bugs.python.org/issue?@action=redirect&bpo=42140

   (46) https://bugs.python.org/issue?@action=redirect&bpo=42133

   (47) https://bugs.python.org/issue?@action=redirect&bpo=26131

   (48) https://bugs.python.org/issue?@action=redirect&bpo=39825

   (49) https://bugs.python.org/issue?@action=redirect&bpo=26389

   (50) https://bugs.python.org/issue?@action=redirect&bpo=41889

   (51) https://bugs.python.org/issue?@action=redirect&bpo=41861

   (52) https://bugs.python.org/issue?@action=redirect&bpo=40624

   (53) https://bugs.python.org/issue?@action=redirect&bpo=28850

   (54) https://bugs.python.org/issue?@action=redirect&bpo=41625

   (55) https://bugs.python.org/issue?@action=redirect&bpo=34215

   (56) https://bugs.python.org/issue?@action=redirect&bpo=41543

   (57) https://bugs.python.org/issue?@action=redirect&bpo=21041

   (58) https://bugs.python.org/issue?@action=redirect&bpo=41332

   (59) https://bugs.python.org/issue?@action=redirect&bpo=12800

   (60) https://bugs.python.org/issue?@action=redirect&bpo=40968

   (61) https://bugs.python.org/issue?@action=redirect&bpo=41001

   (62) https://bugs.python.org/issue?@action=redirect&bpo=40816

   (63) https://bugs.python.org/issue?@action=redirect&bpo=40550

   (64) https://bugs.python.org/issue?@action=redirect&bpo=39411

   (65) https://bugs.python.org/issue?@action=redirect&bpo=35498


File: python.info,  Node: Documentation<41>,  Next: Tests<41>,  Prev: Library<132>,  Up: Python 3 10 0 alpha 3

1.24.47.10 Documentation
........................

   - bpo-42238(1): Tentative to deprecate ‘make suspicious’ by first
     removing it from the CI and documentation builds, but keeping it
     around for manual uses.

   - bpo-42153(2): Fix the URL for the IMAP protocol documents.

   - bpo-41028(3): Language and version switchers, previously maintained
     in every cpython branches, are now handled by docsbuild-script.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42238

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42153

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41028


File: python.info,  Node: Tests<41>,  Next: Build<48>,  Prev: Documentation<41>,  Up: Python 3 10 0 alpha 3

1.24.47.11 Tests
................

   - bpo-41473(1): Re-enable test_gdb on gdb 9.2 and newer:
     ‘https://bugzilla.redhat.com/show_bug.cgi?id=1866884’ bug is fixed
     in gdb 10.1.

   - bpo-42553(2): Fix ‘test_asyncio.test_call_later()’ race condition:
     don’t measure asyncio performance in the ‘call_later()’ unit test.
     The test failed randomly on the CI.

   - bpo-31904(3): Fix test_netrc on VxWorks: create temporary
     directories using temp_cwd().

   - bpo-31904(4): skip test_getaddrinfo_ipv6_scopeid_symbolic and
     test_getnameinfo_ipv6_scopeid_symbolic on VxWorks

   - bpo-31904(5): skip test_test of test_mailcap on VxWorks

   - bpo-31904(6): add shell requirement for test_pipes

   - bpo-31904(7): skip some tests related to fifo on VxWorks

   - bpo-31904(8): Fix test_doctest.py failures for VxWorks.

   - bpo-40754(9): Include ‘_testinternalcapi’ module in Windows
     installer for test suite

   - bpo-41561(10): test_ssl: skip test_min_max_version_mismatch when
     TLS 1.0 is not available

   - bpo-31904(11): Fix os module failures for VxWorks RTOS.

   - bpo-31904(12): Fix fifo test cases for VxWorks RTOS.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41473

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42553

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (8) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40754

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41561

   (11) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31904


File: python.info,  Node: Build<48>,  Next: Windows<41>,  Prev: Tests<41>,  Up: Python 3 10 0 alpha 3

1.24.47.12 Build
................

   - bpo-31904(1): remove libnet dependency from detect_socket() for
     VxWorks

   - bpo-42398(2): Fix a race condition in «make regen-all» when make
     -jN option is used to run jobs in parallel.  The clinic.py script
     now only use atomic write to write files.  Moveover, generated
     files are now left unchanged if the content does not change, to not
     change the file modification time.

   - bpo-41617(3): Fix building ‘pycore_bitutils.h’ internal header on
     old clang version without ‘__builtin_bswap16()’ (ex: Xcode 4.6.3 on
     Mac OS X 10.7).  Patch by Joshua Root and Victor Stinner.

   - bpo-38823(4): It is no longer possible to build the ‘_ctypes’
     extension module without ‘wchar_t’ type: remove ‘CTYPES_UNICODE’
     macro.  Anyway, the ‘wchar_t’ type is required to build Python.
     Patch by Victor Stinner.

   - bpo-42087(5): Support was removed for AIX 5.3 and below.  See
     bpo-40680(6).

   - bpo-40998(7): Addressed three compiler warnings found by undefined
     behavior sanitizer (ubsan).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42398

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41617

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38823

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42087

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40680

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40998


File: python.info,  Node: Windows<41>,  Next: macOS<31>,  Prev: Build<48>,  Up: Python 3 10 0 alpha 3

1.24.47.13 Windows
..................

   - bpo-42120(1): Remove macro definition of ‘copysign’ (to
     ‘_copysign’) in headers.

   - bpo-38506(2): The Windows launcher now properly handles Python 3.10
     when listing installed Python versions.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42120

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38506


File: python.info,  Node: macOS<31>,  Next: IDLE<24>,  Prev: Windows<41>,  Up: Python 3 10 0 alpha 3

1.24.47.14 macOS
................

   - bpo-42504(1): Fix build on macOS Big Sur when
     MACOSX_DEPLOYMENT_TARGET=11

   - bpo-41116(2): Ensure distutils.unixxcompiler.find_library_file can
     find system provided libraries on macOS 11.

   - bpo-41100(3): Add support for macOS 11 and Apple Silicon systems.

     It is now possible to build «Universal 2» binaries using
     «–enable-universalsdk –with-universal-archs=universal2».

     Binaries build on later macOS versions can be deployed back to
     older versions (tested up to macOS 10.9), when using the correct
     deployment target.  This is tested using Xcode 11 and later.

   - bpo-42232(4): Added Darwin specific madvise options to mmap module.

   - bpo-38443(5): The ‘--enable-universalsdk’ and
     ‘--with-universal-archs’ options for the configure script now check
     that the specified architectures can be used.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42504

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41116

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41100

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42232

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38443


File: python.info,  Node: IDLE<24>,  Next: Tools/Demos<29>,  Prev: macOS<31>,  Up: Python 3 10 0 alpha 3

1.24.47.15 IDLE
...............

   - bpo-42508(1): Keep IDLE running on macOS. Remove obsolete
     workaround that prevented running files with shortcuts when using
     new universal2 installers built on macOS 11.

   - bpo-42426(2): Fix reporting offset of the RE error in searchengine.

   - bpo-42415(3): Get docstrings for IDLE calltips more often by using
     inspect.getdoc.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42508

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42426

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42415


File: python.info,  Node: Tools/Demos<29>,  Next: C API<43>,  Prev: IDLE<24>,  Up: Python 3 10 0 alpha 3

1.24.47.16 Tools/Demos
......................

   - bpo-42212(1): The smelly.py script now also checks the Python
     dynamic library and extension modules, not only the Python static
     library.  Make also the script more verbose: explain what it does.

   - bpo-36310(2): Allow ‘Tools/i18n/pygettext.py’ to detect calls to
     ‘gettext’ in f-strings.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42212

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36310


File: python.info,  Node: C API<43>,  Prev: Tools/Demos<29>,  Up: Python 3 10 0 alpha 3

1.24.47.17 C API
................

   - bpo-42423(1): The *note PyType_FromSpecWithBases(): 79f. and *note
     PyType_FromModuleAndSpec(): 774. functions now accept a single
     class as the 'bases' argument.

   - bpo-1635741(2): Port *note select: c6. extension module to
     multiphase initialization ( PEP 489(3)).

   - bpo-1635741(4): Port _posixsubprocess extension module to
     multiphase initialization ( PEP 489(5)).

   - bpo-1635741(6): Port _posixshmem extension module to multiphase
     initialization ( PEP 489(7))

   - bpo-1635741(8): Port _struct extension module to multiphase
     initialization ( PEP 489(9))

   - bpo-1635741(10): Port ‘spwd’ extension module to multiphase
     initialization ( PEP 489(11))

   - bpo-1635741(12): Port *note gc: 64. extension module to multiphase
     initialization ( PEP 489(13))

   - bpo-1635741(14): Port _queue extension module to multiphase
     initialization ( PEP 489(15))

   - bpo-39573(16): Convert *note Py_TYPE(): 3c9. and *note Py_SIZE():
     986. back to macros to allow using them as an l-value.  Many third
     party C extension modules rely on the ability of using Py_TYPE()
     and Py_SIZE() to set an object type and size: ‘Py_TYPE(obj) =
     type;’ and ‘Py_SIZE(obj) = size;’.

   - bpo-1635741(17): Port *note symtable: de. extension module to
     multiphase initialization ( PEP 489(18))

   - bpo-1635741(19): Port *note grp: 6a. and *note pwd: b7. extension
     modules to multiphase initialization ( PEP 489(20))

   - bpo-1635741(21): Port _random extension module to multiphase
     initialization ( PEP 489(22))

   - bpo-1635741(23): Port _hashlib extension module to multiphase
     initialization ( PEP 489(24))

   - bpo-41713(25): Removed the undocumented ‘PyOS_InitInterrupts()’
     function.  Initializing Python already implicitly installs signal
     handlers: see *note PyConfig.install_signal_handlers: abd.  Patch
     by Victor Stinner.

   - bpo-40170(26): The ‘Py_TRASHCAN_BEGIN’ macro no longer accesses
     PyTypeObject attributes, but now can get the condition by calling
     the new private ‘_PyTrash_cond()’ function which hides
     implementation details.

   - bpo-42260(27): *note Py_GetPath(): 3e3, *note Py_GetPrefix(): 3e5,
     *note Py_GetExecPrefix(): 3e9, *note Py_GetProgramFullPath(): 3ec,
     *note Py_GetPythonHome(): 3ef. and *note Py_GetProgramName(): 3ee.
     functions now return ‘NULL’ if called before *note Py_Initialize():
     460. (before Python is initialized).  Use the new *note Python
     Initialization Configuration API: 646. to get the *note Python Path
     Configuration.: aac.  Patch by Victor Stinner.

   - bpo-42260(28): The *note PyConfig_Read(): 994. function now only
     parses *note PyConfig.argv: 3f1. arguments once: *note
     PyConfig.parse_argv: 1cd9. is set to ‘2’ after arguments are
     parsed.  Since Python arguments are strippped from *note
     PyConfig.argv: 3f1, parsing arguments twice would parse the
     application options as Python options.

   - bpo-42262(29): Added *note Py_NewRef(): a9c. and *note
     Py_XNewRef(): a9d. functions to increment the reference count of an
     object and return the object.  Patch by Victor Stinner.

   - bpo-42260(30): When *note Py_Initialize(): 460. is called twice,
     the second call now updates more *note sys: df. attributes for the
     configuration, rather than only *note sys.argv: 146c.  Patch by
     Victor Stinner.

   - bpo-41832(31): The *note PyType_FromModuleAndSpec(): 774. function
     now accepts NULL ‘tp_doc’ slot.

   - bpo-1635741(32): Added *note PyModule_AddObjectRef(): 60a.
     function: similar to *note PyModule_AddObject(): 60b. but don’t
     steal a reference to the value on success.  Patch by Victor
     Stinner.

   - bpo-42171(33): The *note METH_FASTCALL: 1986. calling convention is
     added to the limited API. The functions *note PyModule_AddType():
     b6e, *note PyType_FromModuleAndSpec(): 774, *note
     PyType_GetModule(): b68. and *note PyType_GetModuleState(): b69.
     are added to the limited API on Windows.

   - bpo-42085(34): Add dedicated entry to PyAsyncMethods for sending
     values

   - bpo-41073(35): *note PyType_GetSlot(): a9e. can now accept static
     types.

   - bpo-30459(36): *note PyList_SET_ITEM(): 62f, *note
     PyTuple_SET_ITEM(): 62e. and *note PyCell_SET(): aad. macros can no
     longer be used as l-value or r-value.  For example, ‘x =
     PyList_SET_ITEM(a, b, c)’ and ‘PyList_SET_ITEM(a, b, c) = x’ now
     fail with a compiler error.  It prevents bugs like ‘if
     (PyList_SET_ITEM (a, b, c) < 0) ...’ test.  Patch by Zackery Spytz
     and Victor Stinner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42423

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (3) https://peps.python.org/pep-0489/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (5) https://peps.python.org/pep-0489/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (7) https://peps.python.org/pep-0489/

   (8) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (9) https://peps.python.org/pep-0489/

   (10) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (11) https://peps.python.org/pep-0489/

   (12) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (13) https://peps.python.org/pep-0489/

   (14) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (15) https://peps.python.org/pep-0489/

   (16) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (17) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (18) https://peps.python.org/pep-0489/

   (19) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (20) https://peps.python.org/pep-0489/

   (21) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (22) https://peps.python.org/pep-0489/

   (23) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (24) https://peps.python.org/pep-0489/

   (25) https://bugs.python.org/issue?@action=redirect&bpo=41713

   (26) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (27) https://bugs.python.org/issue?@action=redirect&bpo=42260

   (28) https://bugs.python.org/issue?@action=redirect&bpo=42260

   (29) https://bugs.python.org/issue?@action=redirect&bpo=42262

   (30) https://bugs.python.org/issue?@action=redirect&bpo=42260

   (31) https://bugs.python.org/issue?@action=redirect&bpo=41832

   (32) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (33) https://bugs.python.org/issue?@action=redirect&bpo=42171

   (34) https://bugs.python.org/issue?@action=redirect&bpo=42085

   (35) https://bugs.python.org/issue?@action=redirect&bpo=41073

   (36) https://bugs.python.org/issue?@action=redirect&bpo=30459


File: python.info,  Node: Python 3 10 0 alpha 2,  Next: Python 3 10 0 alpha 1,  Prev: Python 3 10 0 alpha 3,  Up: Changelog

1.24.48 Python 3.10.0 alpha 2
-----------------------------

'Release date: 2020-11-03'

* Menu:

* Security: Security<35>.
* Core and Builtins: Core and Builtins<130>.
* Library: Library<133>.
* Core and Builtins: Core and Builtins<131>.
* Library: Library<134>.
* Documentation: Documentation<42>.
* Tests: Tests<42>.
* Build: Build<49>.
* Windows: Windows<42>.
* macOS: macOS<32>.
* IDLE: IDLE<25>.
* C API: C API<44>.


File: python.info,  Node: Security<35>,  Next: Core and Builtins<130>,  Up: Python 3 10 0 alpha 2

1.24.48.1 Security
..................

   - bpo-42103(1): Prevented potential DoS attack via CPU and RAM
     exhaustion when processing malformed Apple Property List files in
     binary format.

   - bpo-42051(2): The *note plistlib: b0. module no longer accepts
     entity declarations in XML plist files to avoid XML
     vulnerabilities.  This should not affect users as entity
     declarations are not used in regular plist files.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42103

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42051


File: python.info,  Node: Core and Builtins<130>,  Next: Library<133>,  Prev: Security<35>,  Up: Python 3 10 0 alpha 2

1.24.48.2 Core and Builtins
...........................

   - bpo-42236(1): If the ‘nl_langinfo(CODESET)’ function returns an
     empty string, Python now uses UTF-8 as the filesystem encoding.
     Patch by Victor Stinner.

   - bpo-42218(2): Fixed a bug in the PEG parser that was causing
     crashes in debug mode.  Now errors are checked in left-recursive
     rules to avoid cases where such errors do not get handled in time
     and appear as long-distance crashes in other places.

   - bpo-42214(3): Fixed a possible crash in the PEG parser when
     checking for the “!=” token in the ‘barry_as_flufl’ rule.  Patch by
     Pablo Galindo.

   - bpo-42206(4): Propagate and raise the errors caused by
     ‘PyAST_Validate()’ in the parser.

   - bpo-41796(5): The *note ast: 9. module internal state is now per
     interpreter.  Patch by Victor Stinner.

   - bpo-42143(6): Fix handling of errors during creation of
     ‘PyFunctionObject’, which resulted in operations on uninitialized
     memory.  Patch by Yonatan Goldschmidt.

   - bpo-41659(7): Fix a bug in the parser, where a curly brace
     following a ‘primary’ didn’t fail immediately.  This led to invalid
     expressions like ‘a {b}’ to throw a *note SyntaxError: 18e. with a
     wrong offset, or invalid expressions ending with a curly brace like
     ‘a {’ to not fail immediately in the REPL.

   - bpo-42150(8): Fix possible buffer overflow in the new parser when
     checking for continuation lines.  Patch by Pablo Galindo.

   - bpo-42123(9): Run the parser two times.  On the first run, disable
     all the rules that only generate better error messages to gain
     performance.  If there’s a parse failure, run the parser a second
     time with those enabled.

   - bpo-42093(10): The ‘LOAD_ATTR’ instruction now uses new «per opcode
     cache» mechanism and it is about 36% faster now.  Patch by Pablo
     Galindo and Yury Selivanov.

   - bpo-42030(11): Support for the legacy AIX-specific shared library
     loading support has been removed.  All versions of AIX since 4.3
     have supported and defaulted to using the common Unix mechanism
     instead.

   - bpo-41984(12): The garbage collector now tracks all user-defined
     classes.  Patch by Brandt Bucher.

   - bpo-41993(13): Fixed potential issues with removing not completely
     initialized module from ‘sys.modules’ when import fails.

   - bpo-41979(14): Star-unpacking is now allowed for with item’s
     targets in the PEG parser.

   - bpo-41974(15): Removed special methods ‘__int__’, ‘__float__’,
     ‘__floordiv__’, ‘__mod__’, ‘__divmod__’, ‘__rfloordiv__’,
     ‘__rmod__’ and ‘__rdivmod__’ of the *note complex: 197. class.
     They always raised a *note TypeError: 198.

   - bpo-41902(16): Micro optimization when compute *note sq_item: 1cdd.
     and *note mp_subscript: 1cde. of *note range: b3f.  Patch by
     Donghee Na.

   - bpo-41894(17): When loading a native module and a load failure
     occurs, prevent a possible UnicodeDecodeError when not running in a
     UTF-8 locale by decoding the load error message using the current
     locale’s encoding.

   - bpo-41902(18): Micro optimization for range.index if step is 1.
     Patch by Donghee Na.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42236

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42218

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42214

   (4) https://bugs.python.org/issue?@action=redirect&bpo=42206

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41796

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42143

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41659

   (8) https://bugs.python.org/issue?@action=redirect&bpo=42150

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42123

   (10) https://bugs.python.org/issue?@action=redirect&bpo=42093

   (11) https://bugs.python.org/issue?@action=redirect&bpo=42030

   (12) https://bugs.python.org/issue?@action=redirect&bpo=41984

   (13) https://bugs.python.org/issue?@action=redirect&bpo=41993

   (14) https://bugs.python.org/issue?@action=redirect&bpo=41979

   (15) https://bugs.python.org/issue?@action=redirect&bpo=41974

   (16) https://bugs.python.org/issue?@action=redirect&bpo=41902

   (17) https://bugs.python.org/issue?@action=redirect&bpo=41894

   (18) https://bugs.python.org/issue?@action=redirect&bpo=41902


File: python.info,  Node: Library<133>,  Next: Core and Builtins<131>,  Prev: Core and Builtins<130>,  Up: Python 3 10 0 alpha 2

1.24.48.3 Library
.................

   - bpo-41435(1): Add ‘sys._current_exceptions()’ function to retrieve
     a dictionary mapping each thread’s identifier to the topmost
     exception currently active in that thread at the time the function
     is called.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41435


File: python.info,  Node: Core and Builtins<131>,  Next: Library<134>,  Prev: Library<133>,  Up: Python 3 10 0 alpha 2

1.24.48.4 Core and Builtins
...........................

   - bpo-38605(1): Enable ‘from __future__ import annotations’ ( PEP
     563(2)) by default.  The values found in *note __annotations__:
     458. dicts are now strings, for example ‘{"x": "int"}’ instead of
     ‘{"x": int}’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38605

   (2) https://peps.python.org/pep-0563/


File: python.info,  Node: Library<134>,  Next: Documentation<42>,  Prev: Core and Builtins<131>,  Up: Python 3 10 0 alpha 2

1.24.48.5 Library
.................

   - bpo-35455(1): On Solaris, *note thread_time(): b32. is now
     implemented with ‘gethrvtime()’ because
     ‘clock_gettime(CLOCK_THREAD_CPUTIME_ID)’ is not always available.
     Patch by Jakub Kulik.

   - bpo-42233(2): The *note repr(): 1c1. of *note typing: 10a. types
     containing *note Generic Alias Types: 8c2. previously did not show
     the parameterized types in the ‘GenericAlias’.  They have now been
     changed to do so.

   - bpo-29566(3): ‘binhex.binhex()’ consistently writes macOS 9 line
     endings.

   - bpo-26789(4): The *note logging.FileHandler: 1c3b. class now keeps
     a reference to the builtin *note open(): 316. function to be able
     to open or reopen the file during Python finalization.  Fix errors
     like: ‘NameError: name 'open' is not defined’.  Patch by Victor
     Stinner.

   - bpo-42157(5): Removed the ‘unicodedata.ucnhash_CAPI’ attribute
     which was an internal PyCapsule object.  The related private
     ‘_PyUnicode_Name_CAPI’ structure was moved to the internal C API.
     Patch by Victor Stinner.

   - bpo-42157(6): Convert the *note unicodedata: 10b. extension module
     to the multiphase initialization API ( PEP 489(7)) and convert the
     ‘unicodedata.UCD’ static type to a heap type.  Patch by Mohamed
     Koubaa and Victor Stinner.

   - bpo-42146(8): Fix memory leak in *note subprocess.Popen(): 4b8. in
     case an uid (gid) specified in ‘user’ (‘group’, ‘extra_groups’)
     overflows ‘uid_t’ (‘gid_t’).

   - bpo-42103(9): *note InvalidFileException: 1ce2. and *note
     RecursionError: f6a. are now the only errors caused by loading
     malformed binary Plist file (previously ValueError and TypeError
     could be raised in some specific cases).

   - bpo-41490(10): In ‘importlib.resources’, ‘.path’ method is more
     aggressive about releasing handles to zipfile objects early,
     enabling use-cases like certifi to leave the context open but
     delete the underlying zip file.

   - bpo-41052(11): Pickling heap types implemented in C with protocols
     0 and 1 raises now an error instead of producing incorrect data.

   - bpo-42089(12): In ‘importlib.metadata.PackageNotFoundError’, make
     reference to the package metadata being missing to improve the user
     experience.

   - bpo-41491(13): plistlib: fix parsing XML plists with hexadecimal
     integer values

   - bpo-42065(14): Fix an incorrectly formatted error from
     ‘_codecs.charmap_decode()’ when called with a mapped value outside
     the range of valid Unicode code points.  PR by Max Bernstein.

   - bpo-41966(15): Fix pickling pure Python *note datetime.time: 1fb.
     subclasses.  Patch by Dean Inwood.

   - bpo-19270(16): *note sched.scheduler.cancel(): 1ce3. will now
     cancel the correct event, if two events with same priority are
     scheduled for the same time.  Patch by Bar Harel.

   - bpo-28660(17): *note textwrap.wrap(): 16ce. now attempts to break
     long words after hyphens when ‘break_long_words=True’ and
     ‘break_on_hyphens=True’.

   - bpo-35823(18): Use ‘vfork()’ instead of ‘fork()’ for *note
     subprocess.Popen(): 4b8. on Linux to improve performance in cases
     where it is deemed safe.

   - bpo-42043(19): Add support for ‘zipfile.Path’ inheritance.
     ‘zipfile.Path.is_file()’ now returns False for non-existent names.
     ‘zipfile.Path’ objects now expose a ‘.filename’ attribute and rely
     on that to resolve ‘.name’ and ‘.parent’ when the ‘Path’ object is
     at the root of the zipfile.

   - bpo-42021(20): Fix possible ref leaks in *note sqlite3: d4. module
     init.

   - bpo-39101(21): Fixed tests using IsolatedAsyncioTestCase from
     hanging on BaseExceptions.

   - bpo-41976(22): Fixed a bug that was causing *note
     ctypes.util.find_library(): f47. to return ‘None’ when triying to
     locate a library in an environment when gcc>=9 is available and
     ‘ldconfig’ is not.  Patch by Pablo Galindo

   - bpo-41943(23): Fix bug where TestCase.assertLogs doesn’t correctly
     filter messages by level.

   - bpo-41923(24): Implement PEP 613(25), introducing *note
     typing.TypeAlias: 9ce. annotation.

   - bpo-41905(26): A new function in abc: 'update_abstractmethods' to
     re-calculate an abstract class’s abstract status.  In addition,
     'dataclass' has been changed to call this function.

   - bpo-23706(27): Added 'newline' parameter to
     ‘pathlib.Path.write_text()’.

   - bpo-41876(28): Tkinter font class repr uses font name

   - bpo-41831(29): ‘str()’ for the ‘type’ attribute of the
     ‘tkinter.Event’ object always returns now the numeric code returned
     by Tk instead of the name of the event type.

   - bpo-39337(30): *note encodings.normalize_encoding(): 9ff. now
     ignores non-ASCII characters.

   - bpo-41747(31): Ensure all methods that generated from *note
     dataclasses.dataclass(): 4e2. objects now have the proper
     ‘__qualname__’ attribute referring to the class they belong to.
     Patch by Batuhan Taskaya.

   - bpo-30681(32): Handle exceptions caused by unparsable date headers
     when using email «default» policy.  Patch by Tim Bell, Georges Toth

   - bpo-41586(33): Add F_SETPIPE_SZ and F_GETPIPE_SZ to fcntl module.
     Allow setting pipesize on subprocess.Popen.

   - bpo-41229(34): Add ‘contextlib.aclosing’ for deterministic cleanup
     of async generators which is analogous to ‘contextlib.closing’ for
     non-async generators.  Patch by Joongi Kim and John Belmonte.

   - bpo-16396(35): Allow ‘ctypes.wintypes’ to be imported on
     non-Windows systems.

   - bpo-4356(36): Add a key function to the bisect module.

   - bpo-40592(37): *note shutil.which(): 6dc. now ignores empty entries
     in ‘PATHEXT’ instead of treating them as a match.

   - bpo-40492(38): Fix ‘--outfile’ for *note cProfile: 2b. / *note
     profile: b4. not writing the output file in the original directory
     when the program being profiled changes the working directory.  PR
     by Anthony Sottile.

   - bpo-34204(39): The *note shelve: c8. module now uses *note
     pickle.DEFAULT_PROTOCOL: a31. by default instead of *note pickle:
     ab. protocol ‘3’.

   - bpo-27321(40): Fixed KeyError exception when flattening an email to
     a string attempts to replace a non-existent
     Content-Transfer-Encoding header.

   - bpo-38976(41): The *note http.cookiejar: 74. module now supports
     the parsing of cookies in CURL-style cookiejar files through
     MozillaCookieJar on all platforms.  Previously, such cookie entries
     would be silently ignored when loading a cookiejar with such
     entries.

     Additionally, the HTTP Only attribute is persisted in the object,
     and will be correctly written to file if the MozillaCookieJar
     object is subsequently dumped.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35455

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42233

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29566

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26789

   (5) https://bugs.python.org/issue?@action=redirect&bpo=42157

   (6) https://bugs.python.org/issue?@action=redirect&bpo=42157

   (7) https://peps.python.org/pep-0489/

   (8) https://bugs.python.org/issue?@action=redirect&bpo=42146

   (9) https://bugs.python.org/issue?@action=redirect&bpo=42103

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41490

   (11) https://bugs.python.org/issue?@action=redirect&bpo=41052

   (12) https://bugs.python.org/issue?@action=redirect&bpo=42089

   (13) https://bugs.python.org/issue?@action=redirect&bpo=41491

   (14) https://bugs.python.org/issue?@action=redirect&bpo=42065

   (15) https://bugs.python.org/issue?@action=redirect&bpo=41966

   (16) https://bugs.python.org/issue?@action=redirect&bpo=19270

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28660

   (18) https://bugs.python.org/issue?@action=redirect&bpo=35823

   (19) https://bugs.python.org/issue?@action=redirect&bpo=42043

   (20) https://bugs.python.org/issue?@action=redirect&bpo=42021

   (21) https://bugs.python.org/issue?@action=redirect&bpo=39101

   (22) https://bugs.python.org/issue?@action=redirect&bpo=41976

   (23) https://bugs.python.org/issue?@action=redirect&bpo=41943

   (24) https://bugs.python.org/issue?@action=redirect&bpo=41923

   (25) https://peps.python.org/pep-0613/

   (26) https://bugs.python.org/issue?@action=redirect&bpo=41905

   (27) https://bugs.python.org/issue?@action=redirect&bpo=23706

   (28) https://bugs.python.org/issue?@action=redirect&bpo=41876

   (29) https://bugs.python.org/issue?@action=redirect&bpo=41831

   (30) https://bugs.python.org/issue?@action=redirect&bpo=39337

   (31) https://bugs.python.org/issue?@action=redirect&bpo=41747

   (32) https://bugs.python.org/issue?@action=redirect&bpo=30681

   (33) https://bugs.python.org/issue?@action=redirect&bpo=41586

   (34) https://bugs.python.org/issue?@action=redirect&bpo=41229

   (35) https://bugs.python.org/issue?@action=redirect&bpo=16396

   (36) https://bugs.python.org/issue?@action=redirect&bpo=4356

   (37) https://bugs.python.org/issue?@action=redirect&bpo=40592

   (38) https://bugs.python.org/issue?@action=redirect&bpo=40492

   (39) https://bugs.python.org/issue?@action=redirect&bpo=34204

   (40) https://bugs.python.org/issue?@action=redirect&bpo=27321

   (41) https://bugs.python.org/issue?@action=redirect&bpo=38976


File: python.info,  Node: Documentation<42>,  Next: Tests<42>,  Prev: Library<134>,  Up: Python 3 10 0 alpha 2

1.24.48.6 Documentation
.......................

   - bpo-42061(1): Document __format__ functionality for IP addresses.

   - bpo-41910(2): Document the default implementation of
     ‘object.__eq__’.

   - bpo-42010(3): Clarify that subscription expressions are also valid
     for certain *note classes: 1ce5. and *note types: 1ce6. in the
     standard library, and for user-defined classes and types if the
     classmethod ‘__class_getitem__()’ is provided.

   - bpo-41805(4): Documented *note generic alias type: 8c2. and *note
     types.GenericAlias: 9ee.  Also added an entry in glossary for *note
     generic types: 1a1.

   - bpo-39693(5): Fix tarfile’s extractfile documentation

   - bpo-39416(6): Document some restrictions on the default string
     representations of numeric classes.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42061

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41910

   (3) https://bugs.python.org/issue?@action=redirect&bpo=42010

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41805

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39693

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39416


File: python.info,  Node: Tests<42>,  Next: Build<49>,  Prev: Documentation<42>,  Up: Python 3 10 0 alpha 2

1.24.48.7 Tests
...............

   - bpo-41739(1): Fix
     test_logging.test_race_between_set_target_and_flush(): the test now
     waits until all threads complete to avoid leaking running threads.

   - bpo-41970(2): Avoid a test failure in ‘test_lib2to3’ if the module
     has already imported at the time the test executes.  Patch by Pablo
     Galindo.

   - bpo-41944(3): Tests for CJK codecs no longer call ‘eval()’ on
     content received via HTTP.

   - bpo-41306(4): Fixed a failure in ‘test_tk.test_widgets.ScaleTest’
     happening when executing the test with Tk 8.6.10.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41739

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41970

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41944

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41306


File: python.info,  Node: Build<49>,  Next: Windows<42>,  Prev: Tests<42>,  Up: Python 3 10 0 alpha 2

1.24.48.8 Build
...............

   - bpo-38980(1): Add ‘-fno-semantic-interposition’ to both the compile
     and link line when building with ‘--enable-optimizations’.  Patch
     by Victor Stinner and Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38980


File: python.info,  Node: Windows<42>,  Next: macOS<32>,  Prev: Build<49>,  Up: Python 3 10 0 alpha 2

1.24.48.9 Windows
.................

   - bpo-38439(1): Updates the icons for IDLE in the Windows Store
     package.

   - bpo-38252(2): Use 8-byte step to detect ASCII sequence in 64-bit
     Windows build.

   - bpo-39107(3): Update Tcl and Tk to 8.6.10 in Windows installer.

   - bpo-41557(4): Update Windows installer to use SQLite 3.33.0.

   - bpo-38324(5): Avoid Unicode errors when accessing certain locale
     data on Windows.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38439

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38252

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39107

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41557

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38324


File: python.info,  Node: macOS<32>,  Next: IDLE<25>,  Prev: Windows<42>,  Up: Python 3 10 0 alpha 2

1.24.48.10 macOS
................

   - bpo-41471(1): Ignore invalid prefix lengths in system proxy
     excludes.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41471


File: python.info,  Node: IDLE<25>,  Next: C API<44>,  Prev: macOS<32>,  Up: Python 3 10 0 alpha 2

1.24.48.11 IDLE
...............

   - bpo-33987(1): Mostly finish using ttk widgets, mainly for editor,
     settings, and searches.  Some patches by Mark Roseman.

   - bpo-40511(2): Typing opening and closing parentheses inside the
     parentheses of a function call will no longer cause unnecessary
     «flashing» off and on of an existing open call-tip, e.g.  when
     typed in a string literal.

   - bpo-38439(3): Add a 256×256 pixel IDLE icon to the Windows .ico
     file.  Created by Andrew Clover.  Remove the low-color gif
     variations from the .ico file.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33987

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40511

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38439


File: python.info,  Node: C API<44>,  Prev: IDLE<25>,  Up: Python 3 10 0 alpha 2

1.24.48.12 C API
................

   - bpo-42157(1): The private ‘_PyUnicode_Name_CAPI’ structure of the
     PyCapsule API ‘unicodedata.ucnhash_CAPI’ has been moved to the
     internal C API. Patch by Victor Stinner.

   - bpo-42015(2): Fix potential crash in deallocating method objects
     when dynamically allocated *note PyMethodDef: 16de.’s lifetime is
     managed through the ‘self’ argument of a *note PyCFunction: 167f.

   - bpo-40423(3): The *note subprocess: dc. module and ‘os.closerange’
     will now use the ‘close_range(low, high, flags)’ syscall when it is
     available for more efficient closing of ranges of descriptors.

   - bpo-41845(4): *note PyObject_GenericGetDict(): 1ced. is available
     again in the limited API when targeting 3.10 or later.

   - bpo-40422(5): Add ‘_Py_closerange’ function to provide performant
     closing of a range of file descriptors.

   - bpo-41986(6): ‘Py_FileSystemDefaultEncodeErrors’ and ‘Py_UTF8Mode’
     are available again in limited API.

   - bpo-41756(7): Add ‘PyIter_Send’ function to allow sending value
     into generator/coroutine/iterator without raising StopIteration
     exception to signal return.

   - bpo-41784(8): Added ‘PyUnicode_AsUTF8AndSize’ to the limited C API.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42157

   (2) https://bugs.python.org/issue?@action=redirect&bpo=42015

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40423

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41845

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40422

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41986

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41756

   (8) https://bugs.python.org/issue?@action=redirect&bpo=41784


File: python.info,  Node: Python 3 10 0 alpha 1,  Next: Python 3 9 0 beta 1,  Prev: Python 3 10 0 alpha 2,  Up: Changelog

1.24.49 Python 3.10.0 alpha 1
-----------------------------

'Release date: 2020-10-05'

* Menu:

* Security: Security<36>.
* Core and Builtins: Core and Builtins<132>.
* Library: Library<135>.
* Core and Builtins: Core and Builtins<133>.
* Library: Library<136>.
* Core and Builtins: Core and Builtins<134>.
* Library: Library<137>.
* Core and Builtins: Core and Builtins<135>.
* Library: Library<138>.
* Core and Builtins: Core and Builtins<136>.
* Library: Library<139>.
* Core and Builtins: Core and Builtins<137>.
* Library: Library<140>.
* Core and Builtins: Core and Builtins<138>.
* Library: Library<141>.
* Core and Builtins: Core and Builtins<139>.
* Library: Library<142>.
* Core and Builtins: Core and Builtins<140>.
* Library: Library<143>.
* Core and Builtins: Core and Builtins<141>.
* Library: Library<144>.
* Core and Builtins: Core and Builtins<142>.
* Library: Library<145>.
* Core and Builtins: Core and Builtins<143>.
* Library: Library<146>.
* Core and Builtins: Core and Builtins<144>.
* Library: Library<147>.
* Core and Builtins: Core and Builtins<145>.
* Library: Library<148>.
* Core and Builtins: Core and Builtins<146>.
* Library: Library<149>.
* Documentation: Documentation<43>.
* Tests: Tests<43>.
* Build: Build<50>.
* Windows: Windows<43>.
* macOS: macOS<33>.
* IDLE: IDLE<26>.
* C API: C API<45>.


File: python.info,  Node: Security<36>,  Next: Core and Builtins<132>,  Up: Python 3 10 0 alpha 1

1.24.49.1 Security
..................

   - bpo-41304(1): Fixes ‘python3x._pth’ being ignored on Windows,
     caused by the fix for bpo-29778(2) ( CVE 2020-15801(3)).

   - bpo-41162(4): Audit hooks are now cleared later during finalization
     to avoid missing events.

   - bpo-29778(5): Ensure ‘python3.dll’ is loaded from correct locations
     when Python is embedded ( CVE 2020-15523(6)).

   - bpo-41004(7): The __hash__() methods of ipaddress.IPv4Interface and
     ipaddress.IPv6Interface incorrectly generated constant hash values
     of 32 and 128 respectively.  This resulted in always causing hash
     collisions.  The fix uses hash() to generate hash values for the
     tuple of (address, mask length, network address).

   - bpo-39603(8): Prevent http header injection by rejecting control
     characters in http.client.putrequest(…).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41304

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29778

   (3) https://www.cve.org/CVERecord?id=CVE-2020-15801

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41162

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29778

   (6) https://www.cve.org/CVERecord?id=CVE-2020-15523

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41004

   (8) https://bugs.python.org/issue?@action=redirect&bpo=39603


File: python.info,  Node: Core and Builtins<132>,  Next: Library<135>,  Prev: Security<36>,  Up: Python 3 10 0 alpha 1

1.24.49.2 Core and Builtins
...........................

   - bpo-41909(1): Fixed stack overflow in *note issubclass(): 9c6. and
     *note isinstance(): 2ad. when getting the ‘__bases__’ attribute
     leads to infinite recursion.

   - bpo-41922(2): Speed up calls to ‘reversed()’ by using the PEP
     590(3) ‘vectorcall’ calling convention.  Patch by Donghee Na.

   - bpo-41873(4): Calls to ‘float()’ are now faster due to the
     ‘vectorcall’ calling convention.  Patch by Dennis Sweeney.

   - bpo-41870(5): Speed up calls to ‘bool()’ by using the PEP 590(6)
     ‘vectorcall’ calling convention.  Patch by Donghee Na.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41909

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41922

   (3) https://peps.python.org/pep-0590/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41873

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41870

   (6) https://peps.python.org/pep-0590/


File: python.info,  Node: Library<135>,  Next: Core and Builtins<133>,  Prev: Core and Builtins<132>,  Up: Python 3 10 0 alpha 1

1.24.49.3 Library
.................

   - bpo-1635741(1): Port the ‘_bisect’ module to the multi-phase
     initialization API ( PEP 489(2)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (2) https://peps.python.org/pep-0489/


File: python.info,  Node: Core and Builtins<133>,  Next: Library<136>,  Prev: Library<135>,  Up: Python 3 10 0 alpha 1

1.24.49.4 Core and Builtins
...........................

   - bpo-39934(1): Correctly count control blocks in “except” in
     compiler.  Ensures that a syntax error, rather a fatal error,
     occurs for deeply nested, named exception handlers.

   - bpo-41780(2): Fix ‘__dir__()’ of *note types.GenericAlias: 9ee.
     Patch by Batuhan Taskaya.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39934

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41780


File: python.info,  Node: Library<136>,  Next: Core and Builtins<134>,  Prev: Core and Builtins<133>,  Up: Python 3 10 0 alpha 1

1.24.49.5 Library
.................

   - bpo-1635741(1): Port the ‘_lsprof’ extension module to multi-phase
     initialization ( PEP 489(2)).

   - bpo-1635741(3): Port the *note cmath: 19. extension module to
     multi-phase initialization ( PEP 489(4)).

   - bpo-1635741(5): Port the ‘_scproxy’ extension module to multi-phase
     initialization ( PEP 489(6)).

   - bpo-1635741(7): Port the *note termios: e7. extension module to
     multi-phase initialization ( PEP 489(8)).

   - bpo-1635741(9): Convert the ‘_sha256’ extension module types to
     heap types.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (2) https://peps.python.org/pep-0489/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (4) https://peps.python.org/pep-0489/

   (5) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (6) https://peps.python.org/pep-0489/

   (7) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (8) https://peps.python.org/pep-0489/

   (9) https://bugs.python.org/issue?@action=redirect&bpo=1635741


File: python.info,  Node: Core and Builtins<134>,  Next: Library<137>,  Prev: Library<136>,  Up: Python 3 10 0 alpha 1

1.24.49.6 Core and Builtins
...........................

   - bpo-41690(1): Fix a possible stack overflow in the parser when
     parsing functions and classes with a huge amount of arguments.
     Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41690


File: python.info,  Node: Library<137>,  Next: Core and Builtins<135>,  Prev: Core and Builtins<134>,  Up: Python 3 10 0 alpha 1

1.24.49.7 Library
.................

   - bpo-1635741(1): Port the ‘_overlapped’ extension module to
     multi-phase initialization ( PEP 489(2)).

   - bpo-1635741(3): Port the ‘_curses_panel’ extension module to
     multi-phase initialization ( PEP 489(4)).

   - bpo-1635741(5): Port the ‘_opcode’ extension module to multi-phase
     initialization ( PEP 489(6)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (2) https://peps.python.org/pep-0489/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (4) https://peps.python.org/pep-0489/

   (5) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (6) https://peps.python.org/pep-0489/


File: python.info,  Node: Core and Builtins<135>,  Next: Library<138>,  Prev: Library<137>,  Up: Python 3 10 0 alpha 1

1.24.49.8 Core and Builtins
...........................

   - bpo-41681(1): Fixes the wrong error description in the error raised
     by using 2 ‘,’ in format string in f-string and *note str.format():
     834.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41681


File: python.info,  Node: Library<138>,  Next: Core and Builtins<136>,  Prev: Core and Builtins<135>,  Up: Python 3 10 0 alpha 1

1.24.49.9 Library
.................

   - bpo-41675(1): The implementation of *note signal.siginterrupt():
     133d. now uses ‘sigaction()’ (if it is available in the system)
     instead of the deprecated ‘siginterrupt()’.  Patch by Pablo
     Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41675


File: python.info,  Node: Core and Builtins<136>,  Next: Library<139>,  Prev: Library<138>,  Up: Python 3 10 0 alpha 1

1.24.49.10 Core and Builtins
............................

   - bpo-41670(1): Prevent line trace being skipped on platforms not
     compiled with ‘USE_COMPUTED_GOTOS’.  Fixes issue where some lines
     nested within a try-except block were not being traced on Windows.

   - bpo-41654(2): Fix a crash that occurred when destroying subclasses
     of *note MemoryError: 1786.  Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41670

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41654


File: python.info,  Node: Library<139>,  Next: Core and Builtins<137>,  Prev: Core and Builtins<136>,  Up: Python 3 10 0 alpha 1

1.24.49.11 Library
..................

   - bpo-1635741(1): Port the *note zlib: 139. extension module to
     multi-phase initialization ( PEP 489(2)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (2) https://peps.python.org/pep-0489/


File: python.info,  Node: Core and Builtins<137>,  Next: Library<140>,  Prev: Library<139>,  Up: Python 3 10 0 alpha 1

1.24.49.12 Core and Builtins
............................

   - bpo-41631(1): The ‘_ast’ module uses again a global state.  Using a
     module state per module instance is causing subtle practical
     problems.  For example, the Mercurial project replaces the
     ‘__import__()’ function to implement lazy import, whereas Python
     expected that ‘import _ast’ always return a fully initialized
     ‘_ast’ module.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41631


File: python.info,  Node: Library<140>,  Next: Core and Builtins<138>,  Prev: Core and Builtins<137>,  Up: Python 3 10 0 alpha 1

1.24.49.13 Library
..................

   - bpo-40077(1): Convert ‘_operator’ to use *note PyType_FromSpec():
     79e.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40077


File: python.info,  Node: Core and Builtins<138>,  Next: Library<141>,  Prev: Library<140>,  Up: Python 3 10 0 alpha 1

1.24.49.14 Core and Builtins
............................

   - bpo-1653741(1): Port ‘_sha3’ to multi-phase init.  Convert static
     types to heap types.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1653741


File: python.info,  Node: Library<141>,  Next: Core and Builtins<139>,  Prev: Core and Builtins<138>,  Up: Python 3 10 0 alpha 1

1.24.49.15 Library
..................

   - bpo-1635741(1): Port the ‘_blake2’ extension module to the
     multi-phase initialization API ( PEP 489(2)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (2) https://peps.python.org/pep-0489/


File: python.info,  Node: Core and Builtins<139>,  Next: Library<142>,  Prev: Library<141>,  Up: Python 3 10 0 alpha 1

1.24.49.16 Core and Builtins
............................

   - bpo-41533(1): Free the stack allocated in ‘va_build_stack’ if
     ‘do_mkstack’ fails and the stack is not a ‘small_stack’.

   - bpo-41531(2): Fix a bug that was dropping keys when compiling dict
     literals with more than 0xFFFF elements.  Patch by Pablo Galindo.

   - bpo-41525(3): The output of ‘python --help’ contains now only ASCII
     characters.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41533

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41531

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41525


File: python.info,  Node: Library<142>,  Next: Core and Builtins<140>,  Prev: Core and Builtins<139>,  Up: Python 3 10 0 alpha 1

1.24.49.17 Library
..................

   - bpo-1635741(1): Port the ‘_sha1’, ‘_sha512’, and ‘_md5’ extension
     modules to multi-phase initialization API ( PEP 489(2)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (2) https://peps.python.org/pep-0489/


File: python.info,  Node: Core and Builtins<140>,  Next: Library<143>,  Prev: Library<142>,  Up: Python 3 10 0 alpha 1

1.24.49.18 Core and Builtins
............................

   - bpo-41431(1): Optimize ‘dict_merge()’ for copying dict (e.g.
     ‘dict(d)’ and ‘{}.update(d)’).

   - bpo-41428(2): Implement PEP 604.  This supports (int | str) etc.
     in place of Union[str, int].

   - bpo-41340(3): Removed fallback implementation for ‘strdup’.

   - bpo-38156(4): Handle interrupts that come after EOF correctly in
     ‘PyOS_StdioReadline’.

   - bpo-41342(5): *note round(): 14e2. with integer argument is now
     faster (9–60%).

   - bpo-41334(6): Constructors *note str(): 169, *note bytes(): 192.
     and *note bytearray(): 344. are now faster (around 30–40% for small
     objects).

   - bpo-41295(7): Resolve a regression in CPython 3.8.4 where defining
     «__setattr__» in a multi-inheritance setup and calling up the
     hierarchy chain could fail if builtins/extension types were
     involved in the base types.

   - bpo-41323(8): Bytecode optimizations are performed directly on the
     control flow graph.  This will result in slightly more compact code
     objects in some circumstances.

   - bpo-41247(9): Always cache the running loop holder when running
     ‘asyncio.set_running_loop’.

   - bpo-41252(10): Fix incorrect refcounting in _ssl.c’s
     ‘_servername_callback()’.

   - bpo-1635741(11): Port *note multiprocessing: 98. to multi-phase
     initialization

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41431

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41428

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41340

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38156

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41342

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41334

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41295

   (8) https://bugs.python.org/issue?@action=redirect&bpo=41323

   (9) https://bugs.python.org/issue?@action=redirect&bpo=41247

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41252

   (11) https://bugs.python.org/issue?@action=redirect&bpo=1635741


File: python.info,  Node: Library<143>,  Next: Core and Builtins<141>,  Prev: Core and Builtins<140>,  Up: Python 3 10 0 alpha 1

1.24.49.19 Library
..................

   - bpo-1635741(1): Port ‘winapi’ to multiphase initialization

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1635741


File: python.info,  Node: Core and Builtins<141>,  Next: Library<144>,  Prev: Library<143>,  Up: Python 3 10 0 alpha 1

1.24.49.20 Core and Builtins
............................

   - bpo-41215(1): Use non-NULL default values in the PEG parser keyword
     list to overcome a bug that was preventing Python from being
     properly compiled when using the XLC compiler.  Patch by Pablo
     Galindo.

   - bpo-41218(2): Python 3.8.3 had a regression where compiling with
     ast.PyCF_ALLOW_TOP_LEVEL_AWAIT would aggressively mark list
     comprehension with CO_COROUTINE. Now only list comprehension making
     use of async/await will tagged as so.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41215

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41218


File: python.info,  Node: Library<144>,  Next: Core and Builtins<142>,  Prev: Core and Builtins<141>,  Up: Python 3 10 0 alpha 1

1.24.49.21 Library
..................

   - bpo-1635741(1): Port *note faulthandler: 5c. to multiphase
     initialization.

   - bpo-1635741(2): Port ‘sha256’ to multiphase initialization

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1635741


File: python.info,  Node: Core and Builtins<142>,  Next: Library<145>,  Prev: Library<144>,  Up: Python 3 10 0 alpha 1

1.24.49.22 Core and Builtins
............................

   - bpo-41175(1): Guard against a NULL pointer dereference within
     bytearrayobject triggered by the ‘bytearray() + bytearray()’
     operation.

   - bpo-41100(2): add arm64 to the allowable Mac OS arches in
     mpdecimal.h

   - bpo-41094(3): Fix decoding errors with audit when open files with
     non-ASCII names on non-UTF-8 locale.

   - bpo-39960(4): The «hackcheck» that prevents sneaking around a
     type’s __setattr__() by calling the superclass method was rewritten
     to allow C implemented heap types.

   - bpo-41084(5): Prefix the error message with “f-string: “, when
     parsing an f-string expression which throws a *note SyntaxError:
     18e.

   - bpo-40521(6): Empty frozensets are no longer singletons.

   - bpo-41076(7): Pre-feed the parser with the location of the f-string
     expression, not the f-string itself, which allows us to skip the
     shifting of the AST node locations after the parsing is completed.

   - bpo-41056(8): Fixes a reference to deallocated stack space during
     startup when constructing sys.path involving a relative symlink
     when code was supplied via -c.  (discovered via Coverity)

   - bpo-41061(9): Fix incorrect expressions and asserts in hashtable
     code and tests.

   - bpo-41052(10): Opt out serialization/deserialization for
     _random.Random

   - bpo-40939(11): Rename ‘PyPegen*’ functions to ‘PyParser*’, so that
     we can remove the old set of ‘PyParser*’ functions that were using
     the old parser, but keep everything backwards-compatible.

   - bpo-35975(12): Stefan Behnel reported that cf_feature_version is
     used even when PyCF_ONLY_AST is not set.  This is against the
     intention and against the documented behavior, so it’s been fixed.

   - bpo-40939(13): Remove the remaining files from the old parser and
     the ‘symbol’ module.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41175

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41100

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41094

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39960

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41084

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40521

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41076

   (8) https://bugs.python.org/issue?@action=redirect&bpo=41056

   (9) https://bugs.python.org/issue?@action=redirect&bpo=41061

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41052

   (11) https://bugs.python.org/issue?@action=redirect&bpo=40939

   (12) https://bugs.python.org/issue?@action=redirect&bpo=35975

   (13) https://bugs.python.org/issue?@action=redirect&bpo=40939


File: python.info,  Node: Library<145>,  Next: Core and Builtins<143>,  Prev: Core and Builtins<142>,  Up: Python 3 10 0 alpha 1

1.24.49.23 Library
..................

   - bpo-40077(1): Convert ‘_bz2’ to use *note PyType_FromSpec(): 79e.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40077


File: python.info,  Node: Core and Builtins<143>,  Next: Library<146>,  Prev: Library<145>,  Up: Python 3 10 0 alpha 1

1.24.49.24 Core and Builtins
............................

   - bpo-41006(1): The ‘encodings.latin_1’ module is no longer imported
     at startup.  Now it is only imported when it is the filesystem
     encoding or the stdio encoding.

   - bpo-40636(2): *note zip(): 1a0. now supports PEP 618(3)’s ‘strict’
     parameter, which raises a *note ValueError: 2ec. if the arguments
     are exhausted at different lengths.  Patch by Brandt Bucher.

   - bpo-1635741(4): Port ‘_gdbm’ to multiphase initialization.

   - bpo-40985(5): Fix a bug that caused the *note SyntaxError: 18e.
     text to be empty when a file ends with a line ending in a line
     continuation character (i.e.  backslash).  The error text should
     contain the text of the last line.

   - bpo-40958(6): Fix a possible buffer overflow in the PEG parser when
     gathering information for emitting syntax errors.  Patch by Pablo
     Galindo.

   - bpo-1635741(7): Port ‘_dbm’ to multiphase initialization.

   - bpo-40957(8): Fix refleak in _Py_fopen_obj() when PySys_Audit()
     fails

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41006

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40636

   (3) https://peps.python.org/pep-0618/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40985

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40958

   (7) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (8) https://bugs.python.org/issue?@action=redirect&bpo=40957


File: python.info,  Node: Library<146>,  Next: Core and Builtins<144>,  Prev: Core and Builtins<143>,  Up: Python 3 10 0 alpha 1

1.24.49.25 Library
..................

   - bpo-40950(1): Add a state to the ‘nis’ module ( PEP 3121(2)) and
     apply the multiphase initialization.  Patch by Donghee Na.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40950

   (2) https://peps.python.org/pep-3121/


File: python.info,  Node: Core and Builtins<144>,  Next: Library<147>,  Prev: Library<146>,  Up: Python 3 10 0 alpha 1

1.24.49.26 Core and Builtins
............................

   - bpo-40947(1): The Python *note Path Configuration: aac. now takes
     *note PyConfig.platlibdir: 1d09. in account.

   - bpo-40939(2): Remove the old parser, the ‘parser’ module and all
     associated support code, command-line options and environment
     variables.  Patch by Pablo Galindo.

   - bpo-40847(3): Fix a bug where a line with only a line continuation
     character is not considered a blank line at tokenizer level.  In
     such cases, more than a single ‘NEWLINE’ token was emitted.  The
     old parser was working around the issue, but the new parser threw a
     *note SyntaxError: 18e. for valid input due to this.  For example,
     an empty line following a line continuation character was
     interpreted as a *note SyntaxError: 18e.

   - bpo-40890(4): Each dictionary view now has a ‘mapping’ attribute
     that provides a *note types.MappingProxyType: 699. wrapping the
     original dictionary.  Patch contributed by Dennis Sweeney.

   - bpo-40889(5): Improved the performance of symmetric difference
     operations on dictionary item views.  Patch by Dennis Sweeney.

   - bpo-40904(6): Fix possible segfault in the new PEG parser when
     parsing f-string containing yield statements with no value
     (‘f"{yield}"’).  Patch by Pablo Galindo

   - bpo-40903(7): Fixed a possible segfault in the new PEG parser when
     producing error messages for invalid assignments of the form
     ‘p=p=’.  Patch by Pablo Galindo

   - bpo-40880(8): Fix invalid memory read in the new parser when
     checking newlines in string literals.  Patch by Pablo Galindo.

   - bpo-40883(9): Fix memory leak in when parsing f-strings in the new
     parser.  Patch by Pablo Galindo

   - bpo-40870(10): Raise *note ValueError: 2ec. when validating custom
     AST’s where the constants ‘True’, ‘False’ and ‘None’ are used
     within a *note ast.Name: 1d0a. node.

   - bpo-40854(11): Allow overriding *note sys.platlibdir: b34. via a
     new *note PYTHONPLATLIBDIR: 1d0b. environment variable.

   - bpo-40826(12): Fix GIL usage in ‘PyOS_Readline()’: lock the GIL to
     set an exception and pass the Python thread state when checking if
     there is a pending signal.

   - bpo-1635741(13): Port *note fcntl: 5d. to multiphase
     initialization.

   - bpo-19468(14): Delete unnecessary instance check in
     importlib.reload().  Patch by Furkan Önder.

   - bpo-40824(15): Unexpected errors in calling the ‘__iter__’ method
     are no longer masked by ‘TypeError’ in the *note in: 34b. operator
     and functions *note contains(): ad9, *note indexOf(): ada. and
     *note countOf(): adb. of the *note operator: a3. module.

   - bpo-40792(16): Attributes ‘start’, ‘stop’ and ‘step’ of the *note
     range: b3f. object now always has exact type *note int: 19b.
     Previously, they could have been an instance of a subclass of
     ‘int’.

   - bpo-40780(17): Fix a corner case where g-style string formatting of
     a float failed to remove trailing zeros.

   - bpo-38964(18): When there’s a *note SyntaxError: 18e. in the
     expression part of an fstring, the filename attribute of the *note
     SyntaxError: 18e. gets correctly set to the name of the file the
     fstring resides in.

   - bpo-40750(19): Support the «-d» debug flag in the new PEG parser.
     Patch by Pablo Galindo

   - bpo-40217(20): Instances of types created with *note
     PyType_FromSpecWithBases(): 79f. will no longer automatically visit
     their class object when traversing references in the garbage
     collector.  The user is expected to manually visit the object’s
     class.  Patch by Pablo Galindo.

   - bpo-39573(21): *note Py_TYPE(): 3c9. is changed to the inline
     static function.  Patch by Donghee Na.

   - bpo-40696(22): Fix a hang that can arise after *note
     generator.throw(): 71d. due to a cycle in the exception context
     chain.

   - bpo-40521(23): Each interpreter now its has own free lists,
     singletons and caches:

        * Free lists: float, tuple, list, dict, frame, context,
          asynchronous generator, MemoryError.

        * Singletons: empty tuple, empty bytes string, empty Unicode
          string, single byte character, single Unicode (latin1)
          character.

        * Slice cache.

     They are no longer shared by all interpreters.

   - bpo-40679(24): Certain *note TypeError: 198. messages about missing
     or extra arguments now include the function’s *note qualified name:
     1d0c.  Patch by Dennis Sweeney.

   - bpo-29590(25): Make the stack trace correct after calling *note
     generator.throw(): 71d. on a generator that has yielded from a
     ‘yield from’.

   - bpo-4022(26): Improve performance of generators by not raising
     internal StopIteration.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40947

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40939

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40847

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40890

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40889

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40904

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40903

   (8) https://bugs.python.org/issue?@action=redirect&bpo=40880

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40883

   (10) https://bugs.python.org/issue?@action=redirect&bpo=40870

   (11) https://bugs.python.org/issue?@action=redirect&bpo=40854

   (12) https://bugs.python.org/issue?@action=redirect&bpo=40826

   (13) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (14) https://bugs.python.org/issue?@action=redirect&bpo=19468

   (15) https://bugs.python.org/issue?@action=redirect&bpo=40824

   (16) https://bugs.python.org/issue?@action=redirect&bpo=40792

   (17) https://bugs.python.org/issue?@action=redirect&bpo=40780

   (18) https://bugs.python.org/issue?@action=redirect&bpo=38964

   (19) https://bugs.python.org/issue?@action=redirect&bpo=40750

   (20) https://bugs.python.org/issue?@action=redirect&bpo=40217

   (21) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (22) https://bugs.python.org/issue?@action=redirect&bpo=40696

   (23) https://bugs.python.org/issue?@action=redirect&bpo=40521

   (24) https://bugs.python.org/issue?@action=redirect&bpo=40679

   (25) https://bugs.python.org/issue?@action=redirect&bpo=29590

   (26) https://bugs.python.org/issue?@action=redirect&bpo=4022


File: python.info,  Node: Library<147>,  Next: Core and Builtins<145>,  Prev: Core and Builtins<144>,  Up: Python 3 10 0 alpha 1

1.24.49.27 Library
..................

   - bpo-1635741(1): Port *note mmap: 94. to multiphase initialization.

   - bpo-1635741(2): Port ‘_lzma’ to multiphase initialization.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1635741


File: python.info,  Node: Core and Builtins<145>,  Next: Library<148>,  Prev: Library<147>,  Up: Python 3 10 0 alpha 1

1.24.49.28 Core and Builtins
............................

   - bpo-37999(1): Builtin and extension functions that take integer
     arguments no longer accept *note Decimal: 1fe.s, *note Fraction:
     213.s and other objects that can be converted to integers only with
     a loss (e.g.  that have the *note __int__(): 19d. method but do not
     have the *note __index__(): 19e. method).

   - bpo-29882(2): Add *note int.bit_count(): 9d1, counting the number
     of ones in the binary representation of an integer.  Patch by
     Niklas Fiekas.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37999

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29882


File: python.info,  Node: Library<148>,  Next: Core and Builtins<146>,  Prev: Core and Builtins<145>,  Up: Python 3 10 0 alpha 1

1.24.49.29 Library
..................

   - bpo-36982(1): Use ncurses extended color functions when available
     to support terminals with 256 colors, and add the new function
     *note curses.has_extended_color_support(): 9f8. to indicate whether
     extended color support is provided by the underlying ncurses
     library.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36982


File: python.info,  Node: Core and Builtins<146>,  Next: Library<149>,  Prev: Library<148>,  Up: Python 3 10 0 alpha 1

1.24.49.30 Core and Builtins
............................

   - bpo-19569(1): Add the private macros ‘_Py_COMP_DIAG_PUSH’,
     ‘_Py_COMP_DIAG_IGNORE_DEPR_DECLS’, and ‘_Py_COMP_DIAG_POP’.

   - bpo-26680(2): The int type now supports the x.is_integer() method
     for compatibility with float.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19569

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26680


File: python.info,  Node: Library<149>,  Next: Documentation<43>,  Prev: Core and Builtins<146>,  Up: Python 3 10 0 alpha 1

1.24.49.31 Library
..................

   - bpo-41900(1): C14N 2.0 serialisation in xml.etree.ElementTree
     failed for unprefixed attributes when a default namespace was
     defined.

   - bpo-41887(2): Strip leading spaces and tabs on *note
     ast.literal_eval(): e14.  Also document stripping of spaces and
     tabs for *note eval(): 4a4.

   - bpo-41773(3): Note in documentation that *note random.choices():
     ec3. doesn’t support non-finite weights, raise *note ValueError:
     2ec. when given non-finite weights.

   - bpo-41840(4): Fix a bug in the *note symtable: de. module that was
     causing module-scope global variables to not be reported as both
     local and global.  Patch by Pablo Galindo.

   - bpo-41842(5): Add *note codecs.unregister(): 9eb. function to
     unregister a codec search function.

   - bpo-40564(6): In ‘zipfile.Path’, mutate the passed ZipFile object
     type instead of making a copy.  Prevents issues when both the local
     copy and the caller’s copy attempt to close the same file handle.

   - bpo-40670(7): More reliable validation of statements in *note
     timeit.Timer: 16cf.  It now accepts «empty» statements (only
     whitespaces and comments) and rejects misindentent statements.

   - bpo-41833(8): The *note threading.Thread: 176. constructor now uses
     the target name if the 'target' argument is specified but the
     'name' argument is omitted.

   - bpo-41817(9): fix ‘tkinter.EventType’ Enum so all members are
     strings, and none are tuples

   - bpo-41810(10): *note types.EllipsisType: a53, *note
     types.NotImplementedType: a55. and *note types.NoneType: a54. have
     been reintroduced, providing a new set of types readily
     interpretable by static type checkers.

   - bpo-41815(11): Fix SQLite3 segfault when backing up closed
     database.  Patch contributed by Peter David McCormick.

   - bpo-41816(12): StrEnum added: it ensures that all members are
     already strings or string candidates

   - bpo-41517(13): fix bug allowing Enums to be extended via multiple
     inheritance

   - bpo-39587(14): use the correct mix-in data type when constructing
     Enums

   - bpo-41792(15): Add is_typeddict function to typing.py to check if a
     type is a TypedDict class

     Previously there was no way to check that without using private
     API.  See the relevant issue in python/typing(16).

   - bpo-41789(17): Honor ‘object’ overrides in ‘Enum’ class creation
     (specifically, ‘__str__’, ‘__repr__’, ‘__format__’, and
     ‘__reduce_ex__’).

   - bpo-32218(18): ‘enum.Flag’ and ‘enum.IntFlag’ members are now
     iterable.

   - bpo-39651(19): Fix a race condition in the ‘call_soon_threadsafe()’
     method of ‘asyncio.ProactorEventLoop’: do nothing if the self-pipe
     socket has been closed.

   - bpo-1635741(20): Port the ‘mashal’ extension module to the
     multi-phase initialization API ( PEP 489(21)).

   - bpo-1635741(22): Port the ‘_string’ extension module to the
     multi-phase initialization API ( PEP 489(23)).

   - bpo-41732(24): Added an *note iterator: 4c9. to *note memoryview:
     165.

   - bpo-41720(25): Fixed ‘turtle.Vec2D.__rmul__()’ for arguments which
     are not int or float.

   - bpo-41696(26): Fix handling of debug mode in *note asyncio.run():
     2f3.  This allows setting ‘PYTHONASYNCIODEBUG’ or ‘-X dev’ to
     enable asyncio debug mode when using *note asyncio.run(): 2f3.

   - bpo-41687(27): Fix implementation of sendfile to be compatible with
     Solaris.

   - bpo-41662(28): No longer override exceptions raised in ‘__len__()’
     of a sequence of parameters in *note sqlite3: d4. with *note
     ProgrammingError: 305.

   - bpo-39010(29): Restarting a ‘ProactorEventLoop’ on Windows no
     longer logs spurious ‘ConnectionResetErrors’.

   - bpo-41638(30): *note ProgrammingError: 305. message for absent
     parameter in *note sqlite3: d4. contains now the name of the
     parameter instead of its index when parameters are supplied as a
     dict.

   - bpo-41662(31): Fixed crash when mutate list of parameters during
     iteration in *note sqlite3: d4.

   - bpo-41513(32): Improved the accuracy of math.hypot().  Internally,
     each step is computed with extra precision so that the result is
     now almost always correctly rounded.

   - bpo-41609(33): The pdb whatis command correctly reports instance
     methods as “Method” rather than “Function”.

   - bpo-39994(34): Fixed pprint’s handling of dict subclasses that
     override __repr__.

   - bpo-32751(35): When cancelling the task due to a timeout, *note
     asyncio.wait_for(): 816. will now wait until the cancellation is
     complete also in the case when 'timeout' is <= 0, like it does with
     positive timeouts.

   - bpo-37658(36): *note asyncio.wait_for(): 816. now properly handles
     races between cancellation of itself and the completion of the
     wrapped awaitable.

   - bpo-40782(37): Change the method
     asyncio.AbstractEventLoop.run_in_executor to not be a coroutine.

   - bpo-41520(38): Fix *note codeop: 1d. regression that prevented
     turning compile warnings into errors.

   - bpo-41528(39): turtle uses math module functions to convert degrees
     to radians and vice versa and to calculate vector norm

   - bpo-41513(40): Minor algorithmic improvement to math.hypot() and
     math.dist() giving small gains in speed and accuracy.

   - bpo-41503(41): Fixed a race between setTarget and flush in
     logging.handlers.MemoryHandler.

   - bpo-41497(42): Fix potential UnicodeDecodeError in dis module.

   - bpo-41467(43): On Windows, fix asyncio ‘recv_into()’ return value
     when the socket/pipe is closed (*note BrokenPipeError: 125e.):
     return ‘0’ rather than an empty byte string (‘b''’).

   - bpo-41425(44): Make tkinter doc example runnable.

   - bpo-41421(45): Make an algebraic simplification to
     random.paretovariate().  It now is slightly less subject to
     round-off error and is slightly faster.  Inputs that used to cause
     ZeroDivisionError now cause an OverflowError instead.

   - bpo-41440(46): Add *note os.cpu_count(): 4dc. support for VxWorks
     RTOS.

   - bpo-41316(47): Fix the *note tarfile: e4. module to write only
     basename of TAR file to GZIP compression header.

   - bpo-41384(48): Raise TclError instead of TypeError when an unknown
     option is passed to tkinter.OptionMenu.

   - bpo-41317(49): Use add_done_callback() in
     asyncio.loop.sock_accept() to unsubscribe reader early on
     cancellation.

   - bpo-41364(50): Reduce import overhead of *note uuid: 116.

   - bpo-35328(51): Set the environment variable ‘VIRTUAL_ENV_PROMPT’ at
     *note venv: 117. activation.

   - bpo-41341(52): Recursive evaluation of ‘typing.ForwardRef’ in
     ‘get_type_hints’.

   - bpo-41344(53): Prevent creating ‘shared_memory.SharedMemory’
     objects with ‘size=0’.

   - bpo-41333(54): ‘collections.OrderedDict.pop()’ is now 2 times
     faster.

   - bpo-41288(55): Unpickling invalid NEWOBJ_EX opcode with the C
     implementation raises now UnpicklingError instead of crashing.

   - bpo-39017(56): Avoid infinite loop when reading specially crafted
     TAR files using the tarfile module ( CVE 2019-20907(57)).

   - bpo-41273(58): Speed up any transport using
     ‘_ProactorReadPipeTransport’ by calling ‘recv_into’ instead of
     ‘recv’, thus not creating a new buffer for each ‘recv’ call in the
     transport’s read loop.

   - bpo-41235(59): Fix the error handling in *note
     ssl.SSLContext.load_dh_params(): 134a.

   - bpo-41207(60): In distutils.spawn, restore expectation that
     DistutilsExecError is raised when the command is not found.

   - bpo-29727(61): Register *note array.array: 4bf. as a *note
     MutableSequence: 4c0.  Patch by Pablo Galindo.

   - bpo-39168(62): Remove the ‘__new__’ method of *note typing.Generic:
     179e.

   - bpo-41194(63): Fix a crash in the ‘_ast’ module: it can no longer
     be loaded more than once.  It now uses a global state rather than a
     module state.

   - bpo-41195(64): Add read-only ssl.SSLContext.security_level
     attribute to retrieve the context’s security level.

   - bpo-41193(65): The ‘write_history()’ atexit function of the
     readline completer now ignores any *note OSError: 2c0. to ignore
     error if the filesystem is read-only, instead of only ignoring
     *note FileNotFoundError: 264. and *note PermissionError: f40.

   - bpo-41182(66): selector: use DefaultSelector based upon
     implementation

   - bpo-41161(67): The decimal module now requires libmpdec-2.5.0.
     Users of –with-system-libmpdec should update their system library.

   - bpo-40874(68): The decimal module now requires libmpdec-2.5.0.

   - bpo-41138(69): Fixed the *note trace: 103. module CLI for Python
     source files with non-UTF-8 encoding.

   - bpo-31082(70): Use the term «iterable» in the docstring for *note
     functools.reduce(): 21a.

   - bpo-40521(71): Remove freelist from collections.deque().

   - bpo-31938(72): Fix default-value signatures of several functions in
     the *note select: c6. module - by Anthony Sottile.

   - bpo-41068(73): Fixed reading files with non-ASCII names from ZIP
     archive directly after writing them.

   - bpo-41058(74): ‘pdb.find_function()’ now correctly determines the
     source file encoding.

   - bpo-41056(75): Invalid file descriptor values are now prevented
     from being passed to os.fpathconf.  (discovered by Coverity)

   - bpo-41056(76): Fix a NULL pointer dereference within the ssl module
     during a MemoryError in the keylog callback.  (discovered by
     Coverity)

   - bpo-41056(77): Fixed an instance where a MemoryError within the
     zoneinfo module might not be reported or not reported at its
     source.  (found by Coverity)

   - bpo-41048(78): *note mimetypes.read_mime_types(): 1d12. function
     reads the rule file using UTF-8 encoding, not the locale encoding.
     Patch by Srinivas Reddy Thatiparthy.

   - bpo-41043(79): Fixed the use of *note glob(): 5a0. in the stdlib:
     literal part of the path is now always correctly escaped.

   - bpo-41025(80): Fixed an issue preventing the C implementation of
     *note zoneinfo.ZoneInfo: ade. from being subclassed.

   - bpo-35018(81): Add the *note xml.sax.handler.LexicalHandler: a5e.
     class that is present in other SAX XML implementations.

   - bpo-41002(82): Improve performance of HTTPResponse.read with a
     given amount.  Patch by Bruce Merry.

   - bpo-40448(83): *note ensurepip: 59. now disables the use of ‘pip’
     cache when installing the bundled versions of ‘pip’ and
     ‘setuptools’.  Patch by Krzysztof Konopko.

   - bpo-40967(84): Removed ‘asyncio.Task.current_task()’ and
     ‘asyncio.Task.all_tasks()’.  Patch contributed by Rémi Lapeyre.

   - bpo-40924(85): Ensure ‘importlib.resources.path’ returns an extant
     path for the SourceFileLoader’s resource reader.  Avoids the
     regression identified in master while a long-term solution is
     devised.

   - bpo-40955(86): Fix a minor memory leak in *note subprocess: dc.
     module when extra_groups was specified.

   - bpo-40855(87): The standard deviation and variance functions in the
     statistics module were ignoring their mu and xbar arguments.

   - bpo-40939(88): Use the new PEG parser when generating the stdlib
     *note keyword: 88. module.

   - bpo-23427(89): Add *note sys.orig_argv: a43. attribute: the list of
     the original command line arguments passed to the Python
     executable.

   - bpo-33689(90): Ignore empty or whitespace-only lines in .pth files.
     This matches the documentated behavior.  Before, empty lines caused
     the site-packages dir to appear multiple times in sys.path.  By Ido
     Michael, contributors Malcolm Smith and Tal Einat.

   - bpo-40884(91): Added a ‘defaults’ parameter to *note
     logging.Formatter: 169e, to allow specifying default values for
     custom fields.  Patch by Asaf Alon and Bar Harel.

   - bpo-40876(92): Clarify error message in the *note csv: 2d. module.

   - bpo-39791(93): Refresh importlib.metadata from importlib_metadata
     1.6.1.

   - bpo-40807(94): Stop codeop._maybe_compile, used by
     code.InteractiveInterpreter (and IDLE). from emitting each warning
     three times.

   - bpo-32604(95): Fix reference leak in the *note select: c6. module
     when the module is imported in a subinterpreter.

   - bpo-39791(96): Built-in loaders (SourceFileLoader and ZipImporter)
     now supply ‘TraversableResources’ implementations for
     ‘ResourceReader’, and the fallback function has been removed.

   - bpo-39314(97): *note rlcompleter.Completer: 1d13. and the standard
     Python shell now close the parenthesis for functions that take no
     arguments.  Patch contributed by Rémi Lapeyre.

   - bpo-17005(98): The topological sort functionality that was
     introduced initially in the *note functools: 63. module has been
     moved to a new *note graphlib: 69. module to better accommodate the
     new tools and keep the original scope of the *note functools: 63.
     module.  Patch by Pablo Galindo

   - bpo-40834(99): Fix truncate when sending str object
     with_xxsubinterpreters.channel_send.

   - bpo-40755(100): Add rich comparisons to collections.Counter().

   - bpo-26407(101): Unexpected errors in calling the ‘__iter__’ method
     are no longer masked by ‘TypeError’ in *note csv.reader(): 6af,
     ‘csv.writer.writerow()’ and ‘csv.writer.writerows()’.

   - bpo-39384(102): Fixed email.contentmanager to allow set_content()
     to set a null string.

   - bpo-40744(103): The *note sqlite3: d4. module uses SQLite API
     functions that require SQLite v3.7.3 or higher.  This patch removes
     support for older SQLite versions, and explicitly requires SQLite
     3.7.3 both at build, compile and runtime.  Patch by Sergey Fedoseev
     and Erlend E. Aasland.

   - bpo-40777(104): Initialize PyDateTime_IsoCalendarDateType.tp_base
     at run-time to avoid errors on some compilers.

   - bpo-38488(105): Update ensurepip to install pip 20.1.1 and
     setuptools 47.1.0.

   - bpo-40792(106): The result of *note operator.index(): 1cba. now
     always has exact type *note int: 19b.  Previously, the result could
     have been an instance of a subclass of ‘int’.

   - bpo-40767(107): *note webbrowser: 11b. now properly finds the
     default browser in pure Wayland systems by checking the
     WAYLAND_DISPLAY environment variable.  Patch contributed by Jérémy
     Attali.

   - bpo-40791(108): ‘hashlib.compare_digest()’ uses OpenSSL’s
     ‘CRYPTO_memcmp()’ function when OpenSSL is available.

   - bpo-40795(109): *note ctypes: 2e. module: If ctypes fails to
     convert the result of a callback or if a ctypes callback function
     raises an exception, sys.unraisablehook is now called with an
     exception set.  Previously, the error was logged into stderr by
     *note PyErr_Print(): 1d14.

   - bpo-16995(110): Add *note base64.b32hexencode(): 9e6. and *note
     base64.b32hexdecode(): 9e7. to support the Base32 Encoding with
     Extended Hex Alphabet.

   - bpo-30008(111): Fix *note ssl: d5. code to be compatible with
     OpenSSL 1.1.x builds that use ‘no-deprecated’ and ‘--api=1.1.0’.

   - bpo-30064(112): Fix asyncio ‘loop.sock_*’ race condition issue

   - bpo-40759(113): Deprecate the ‘symbol’ module.

   - bpo-40756(114): The second argument (extra) of
     ‘LoggerAdapter.__init__’ now defaults to None.

   - bpo-37129(115): Add a new *note os.RWF_APPEND: 1d15. flag for *note
     os.pwritev(): d59.

   - bpo-40737(116): Fix possible reference leak for *note sqlite3: d4.
     initialization.

   - bpo-40726(117): Handle cases where the ‘end_lineno’ is ‘None’ on
     *note ast.increment_lineno(): 1af5.

   - bpo-40698(118): ‘distutils’ upload creates SHA2-256 and Blake2b-256
     digests.  MD5 digests is skipped if platform blocks MD5.

   - bpo-40695(119): *note hashlib: 6c. no longer falls back to builtin
     hash implementations when OpenSSL provides a hash digest and the
     algorithm is blocked by security policy.

   - bpo-9216(120): *note hashlib.new(): 1d16. passed ‘usedforsecurity’
     to OpenSSL EVP constructor ‘_hashlib.new()’.  test_hashlib and
     test_smtplib handle strict security policy better.

   - bpo-40614(121): *note ast.parse(): 1c2. will not parse self
     documenting expressions in f-strings when passed ‘feature_version’
     is less than ‘(3, 8)’.

   - bpo-40626(122): Add h5 file extension as MIME Type
     application/x-hdf5, as per HDF Group recommendation for HDF5
     formatted data files.  Patch contributed by Mark Schwab.

   - bpo-25920(123): On macOS, when building Python for macOS 10.4 and
     older, which wasn’t the case for python.org macOS installer, *note
     socket.getaddrinfo(): 1aab. no longer uses an internal lock to
     prevent race conditions when calling ‘getaddrinfo()’ which is
     thread-safe since macOS 10.5.  Python 3.9 requires macOS 10.6 or
     newer.  The internal lock caused random hang on fork when another
     thread was calling *note socket.getaddrinfo(): 1aab.  The lock was
     also used on FreeBSD older than 5.3, OpenBSD older than 201311 and
     NetBSD older than 4.

   - bpo-40671(124): Prepare ‘_hashlib’ for PEP 489(125) and use *note
     PyModule_AddType(): b6e.

   - bpo-32309(126): Added a new *note coroutine: 6ba. *note
     asyncio.to_thread(): ae7.  It is mainly used for running IO-bound
     functions in a separate thread to avoid blocking the event loop,
     and essentially works as a high-level version of *note
     run_in_executor(): ae8. that can directly take keyword arguments.

   - bpo-36543(127): Restored the deprecated ‘xml.etree.cElementTree’
     module.

   - bpo-40611(128): *note MAP_POPULATE: 1d17. constant has now been
     added to the list of exported *note mmap: 94. module flags.

   - bpo-39881(129): PEP 554 for use in the test suite.  (Patch By
     Joannah Nanjekye)

   - bpo-13097(130): ‘ctypes’ now raises an ‘ArgumentError’ when a
     callback is invoked with more than 1024 arguments.

   - bpo-39385(131): A new test assertion context-manager,
     ‘unittest.assertNoLogs()’ will ensure a given block of code emits
     no log messages using the logging module.  Contributed by Kit Yan
     Choi.

   - bpo-23082(132): Updated the error message and docs of
     PurePath.relative_to() to better reflect the function behaviour.

   - bpo-40318(133): Use SQLite3 trace v2 API, if it is available.

   - bpo-40105(134): ZipFile truncates files to avoid corruption when a
     shorter comment is provided in append («a») mode.  Patch by Jan
     Mazur.

   - bpo-40084(135): Fix ‘Enum.__dir__’: dir(Enum.member) now includes
     attributes as well as methods.

   - bpo-31122(136): ssl.wrap_socket() now raises ssl.SSLEOFError rather
     than OSError when peer closes connection during TLS negotiation

   - bpo-39728(137): fix default ‘_missing_’ so a duplicate ‘ValueError’
     is not set as the ‘__context__’ of the original ‘ValueError’.

   - bpo-39244(138): Fixed
     ‘multiprocessing.context.get_all_start_methods’ to properly return
     the default method first on macOS.

   - bpo-39040(139): Fix parsing of invalid mime headers parameters by
     collapsing whitespace between encoded words in a bare-quote-string.

   - bpo-38731(140): Add ‘--quiet’ option to command-line interface of
     *note py_compile: b8.  Patch by Gregory Schevchenko.

   - bpo-35714(141): *note struct.error: 152b. is now raised if there is
     a null character in a *note struct: db. format string.

   - bpo-38144(142): Added the 'root_dir' and 'dir_fd' parameters in
     *note glob.glob(): 5a0.

   - bpo-26543(143): Fix ‘IMAP4.noop()’ when debug mode is enabled (ex:
     ‘imaplib.Debug = 3’).

   - bpo-12178(144): *note csv.writer(): 6b0. now correctly escapes
     'escapechar' when input contains 'escapechar'.  Patch by Catalin
     Iacob, Berker Peksag, and Itay Elbirt.

   - bpo-36290(145): AST nodes are now raising *note TypeError: 198. on
     conflicting keyword arguments.  Patch contributed by Rémi Lapeyre.

   - bpo-33944(146): Added site.py site-packages tracing in verbose
     mode.

   - bpo-35078(147): Refactor formatweekday, formatmonthname methods in
     LocaleHTMLCalendar and LocaleTextCalendar classes in calendar
     module to call the base class methods.This enables customizable CSS
     classes for LocaleHTMLCalendar.  Patch by Srinivas Reddy
     Thatiparthy

   - bpo-29620(148): *note assertWarns(): 136c. no longer raises a
     ‘RuntimeException’ when accessing a module’s ‘__warningregistry__’
     causes importation of a new module, or when a new module is
     imported in another thread.  Patch by Kernc.

   - bpo-31844(149): Remove ‘ParserBase.error()’ method from the private
     and undocumented ‘_markupbase’ module.  *note
     html.parser.HTMLParser: a79. is the only subclass of ‘ParserBase’
     and its ‘error()’ implementation was deprecated in Python 3.4 and
     removed in Python 3.5.

   - bpo-34226(150): Fix ‘cgi.parse_multipart’ without content_length.
     Patch by Roger Duran

   - bpo-33660(151): Fix pathlib.PosixPath to resolve a relative path
     located on the root directory properly.

   - bpo-28557(152): Improve the error message for a misbehaving
     ‘rawio.readinto’

   - bpo-26680(153): The d.is_integer() method is added to the Decimal
     type, for compatibility with other number types.

   - bpo-26680(154): The x.is_integer() method is incorporated into the
     abstract types of the numeric tower, Real, Rational and Integral,
     with appropriate default implementations.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41900

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41887

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41773

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41840

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41842

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40564

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40670

   (8) https://bugs.python.org/issue?@action=redirect&bpo=41833

   (9) https://bugs.python.org/issue?@action=redirect&bpo=41817

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41810

   (11) https://bugs.python.org/issue?@action=redirect&bpo=41815

   (12) https://bugs.python.org/issue?@action=redirect&bpo=41816

   (13) https://bugs.python.org/issue?@action=redirect&bpo=41517

   (14) https://bugs.python.org/issue?@action=redirect&bpo=39587

   (15) https://bugs.python.org/issue?@action=redirect&bpo=41792

   (16) https://github.com/python/typing/issues/751

   (17) https://bugs.python.org/issue?@action=redirect&bpo=41789

   (18) https://bugs.python.org/issue?@action=redirect&bpo=32218

   (19) https://bugs.python.org/issue?@action=redirect&bpo=39651

   (20) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (21) https://peps.python.org/pep-0489/

   (22) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (23) https://peps.python.org/pep-0489/

   (24) https://bugs.python.org/issue?@action=redirect&bpo=41732

   (25) https://bugs.python.org/issue?@action=redirect&bpo=41720

   (26) https://bugs.python.org/issue?@action=redirect&bpo=41696

   (27) https://bugs.python.org/issue?@action=redirect&bpo=41687

   (28) https://bugs.python.org/issue?@action=redirect&bpo=41662

   (29) https://bugs.python.org/issue?@action=redirect&bpo=39010

   (30) https://bugs.python.org/issue?@action=redirect&bpo=41638

   (31) https://bugs.python.org/issue?@action=redirect&bpo=41662

   (32) https://bugs.python.org/issue?@action=redirect&bpo=41513

   (33) https://bugs.python.org/issue?@action=redirect&bpo=41609

   (34) https://bugs.python.org/issue?@action=redirect&bpo=39994

   (35) https://bugs.python.org/issue?@action=redirect&bpo=32751

   (36) https://bugs.python.org/issue?@action=redirect&bpo=37658

   (37) https://bugs.python.org/issue?@action=redirect&bpo=40782

   (38) https://bugs.python.org/issue?@action=redirect&bpo=41520

   (39) https://bugs.python.org/issue?@action=redirect&bpo=41528

   (40) https://bugs.python.org/issue?@action=redirect&bpo=41513

   (41) https://bugs.python.org/issue?@action=redirect&bpo=41503

   (42) https://bugs.python.org/issue?@action=redirect&bpo=41497

   (43) https://bugs.python.org/issue?@action=redirect&bpo=41467

   (44) https://bugs.python.org/issue?@action=redirect&bpo=41425

   (45) https://bugs.python.org/issue?@action=redirect&bpo=41421

   (46) https://bugs.python.org/issue?@action=redirect&bpo=41440

   (47) https://bugs.python.org/issue?@action=redirect&bpo=41316

   (48) https://bugs.python.org/issue?@action=redirect&bpo=41384

   (49) https://bugs.python.org/issue?@action=redirect&bpo=41317

   (50) https://bugs.python.org/issue?@action=redirect&bpo=41364

   (51) https://bugs.python.org/issue?@action=redirect&bpo=35328

   (52) https://bugs.python.org/issue?@action=redirect&bpo=41341

   (53) https://bugs.python.org/issue?@action=redirect&bpo=41344

   (54) https://bugs.python.org/issue?@action=redirect&bpo=41333

   (55) https://bugs.python.org/issue?@action=redirect&bpo=41288

   (56) https://bugs.python.org/issue?@action=redirect&bpo=39017

   (57) https://www.cve.org/CVERecord?id=CVE-2019-20907

   (58) https://bugs.python.org/issue?@action=redirect&bpo=41273

   (59) https://bugs.python.org/issue?@action=redirect&bpo=41235

   (60) https://bugs.python.org/issue?@action=redirect&bpo=41207

   (61) https://bugs.python.org/issue?@action=redirect&bpo=29727

   (62) https://bugs.python.org/issue?@action=redirect&bpo=39168

   (63) https://bugs.python.org/issue?@action=redirect&bpo=41194

   (64) https://bugs.python.org/issue?@action=redirect&bpo=41195

   (65) https://bugs.python.org/issue?@action=redirect&bpo=41193

   (66) https://bugs.python.org/issue?@action=redirect&bpo=41182

   (67) https://bugs.python.org/issue?@action=redirect&bpo=41161

   (68) https://bugs.python.org/issue?@action=redirect&bpo=40874

   (69) https://bugs.python.org/issue?@action=redirect&bpo=41138

   (70) https://bugs.python.org/issue?@action=redirect&bpo=31082

   (71) https://bugs.python.org/issue?@action=redirect&bpo=40521

   (72) https://bugs.python.org/issue?@action=redirect&bpo=31938

   (73) https://bugs.python.org/issue?@action=redirect&bpo=41068

   (74) https://bugs.python.org/issue?@action=redirect&bpo=41058

   (75) https://bugs.python.org/issue?@action=redirect&bpo=41056

   (76) https://bugs.python.org/issue?@action=redirect&bpo=41056

   (77) https://bugs.python.org/issue?@action=redirect&bpo=41056

   (78) https://bugs.python.org/issue?@action=redirect&bpo=41048

   (79) https://bugs.python.org/issue?@action=redirect&bpo=41043

   (80) https://bugs.python.org/issue?@action=redirect&bpo=41025

   (81) https://bugs.python.org/issue?@action=redirect&bpo=35018

   (82) https://bugs.python.org/issue?@action=redirect&bpo=41002

   (83) https://bugs.python.org/issue?@action=redirect&bpo=40448

   (84) https://bugs.python.org/issue?@action=redirect&bpo=40967

   (85) https://bugs.python.org/issue?@action=redirect&bpo=40924

   (86) https://bugs.python.org/issue?@action=redirect&bpo=40955

   (87) https://bugs.python.org/issue?@action=redirect&bpo=40855

   (88) https://bugs.python.org/issue?@action=redirect&bpo=40939

   (89) https://bugs.python.org/issue?@action=redirect&bpo=23427

   (90) https://bugs.python.org/issue?@action=redirect&bpo=33689

   (91) https://bugs.python.org/issue?@action=redirect&bpo=40884

   (92) https://bugs.python.org/issue?@action=redirect&bpo=40876

   (93) https://bugs.python.org/issue?@action=redirect&bpo=39791

   (94) https://bugs.python.org/issue?@action=redirect&bpo=40807

   (95) https://bugs.python.org/issue?@action=redirect&bpo=32604

   (96) https://bugs.python.org/issue?@action=redirect&bpo=39791

   (97) https://bugs.python.org/issue?@action=redirect&bpo=39314

   (98) https://bugs.python.org/issue?@action=redirect&bpo=17005

   (99) https://bugs.python.org/issue?@action=redirect&bpo=40834

   (100) https://bugs.python.org/issue?@action=redirect&bpo=40755

   (101) https://bugs.python.org/issue?@action=redirect&bpo=26407

   (102) https://bugs.python.org/issue?@action=redirect&bpo=39384

   (103) https://bugs.python.org/issue?@action=redirect&bpo=40744

   (104) https://bugs.python.org/issue?@action=redirect&bpo=40777

   (105) https://bugs.python.org/issue?@action=redirect&bpo=38488

   (106) https://bugs.python.org/issue?@action=redirect&bpo=40792

   (107) https://bugs.python.org/issue?@action=redirect&bpo=40767

   (108) https://bugs.python.org/issue?@action=redirect&bpo=40791

   (109) https://bugs.python.org/issue?@action=redirect&bpo=40795

   (110) https://bugs.python.org/issue?@action=redirect&bpo=16995

   (111) https://bugs.python.org/issue?@action=redirect&bpo=30008

   (112) https://bugs.python.org/issue?@action=redirect&bpo=30064

   (113) https://bugs.python.org/issue?@action=redirect&bpo=40759

   (114) https://bugs.python.org/issue?@action=redirect&bpo=40756

   (115) https://bugs.python.org/issue?@action=redirect&bpo=37129

   (116) https://bugs.python.org/issue?@action=redirect&bpo=40737

   (117) https://bugs.python.org/issue?@action=redirect&bpo=40726

   (118) https://bugs.python.org/issue?@action=redirect&bpo=40698

   (119) https://bugs.python.org/issue?@action=redirect&bpo=40695

   (120) https://bugs.python.org/issue?@action=redirect&bpo=9216

   (121) https://bugs.python.org/issue?@action=redirect&bpo=40614

   (122) https://bugs.python.org/issue?@action=redirect&bpo=40626

   (123) https://bugs.python.org/issue?@action=redirect&bpo=25920

   (124) https://bugs.python.org/issue?@action=redirect&bpo=40671

   (125) https://peps.python.org/pep-0489/

   (126) https://bugs.python.org/issue?@action=redirect&bpo=32309

   (127) https://bugs.python.org/issue?@action=redirect&bpo=36543

   (128) https://bugs.python.org/issue?@action=redirect&bpo=40611

   (129) https://bugs.python.org/issue?@action=redirect&bpo=39881

   (130) https://bugs.python.org/issue?@action=redirect&bpo=13097

   (131) https://bugs.python.org/issue?@action=redirect&bpo=39385

   (132) https://bugs.python.org/issue?@action=redirect&bpo=23082

   (133) https://bugs.python.org/issue?@action=redirect&bpo=40318

   (134) https://bugs.python.org/issue?@action=redirect&bpo=40105

   (135) https://bugs.python.org/issue?@action=redirect&bpo=40084

   (136) https://bugs.python.org/issue?@action=redirect&bpo=31122

   (137) https://bugs.python.org/issue?@action=redirect&bpo=39728

   (138) https://bugs.python.org/issue?@action=redirect&bpo=39244

   (139) https://bugs.python.org/issue?@action=redirect&bpo=39040

   (140) https://bugs.python.org/issue?@action=redirect&bpo=38731

   (141) https://bugs.python.org/issue?@action=redirect&bpo=35714

   (142) https://bugs.python.org/issue?@action=redirect&bpo=38144

   (143) https://bugs.python.org/issue?@action=redirect&bpo=26543

   (144) https://bugs.python.org/issue?@action=redirect&bpo=12178

   (145) https://bugs.python.org/issue?@action=redirect&bpo=36290

   (146) https://bugs.python.org/issue?@action=redirect&bpo=33944

   (147) https://bugs.python.org/issue?@action=redirect&bpo=35078

   (148) https://bugs.python.org/issue?@action=redirect&bpo=29620

   (149) https://bugs.python.org/issue?@action=redirect&bpo=31844

   (150) https://bugs.python.org/issue?@action=redirect&bpo=34226

   (151) https://bugs.python.org/issue?@action=redirect&bpo=33660

   (152) https://bugs.python.org/issue?@action=redirect&bpo=28557

   (153) https://bugs.python.org/issue?@action=redirect&bpo=26680

   (154) https://bugs.python.org/issue?@action=redirect&bpo=26680


File: python.info,  Node: Documentation<43>,  Next: Tests<43>,  Prev: Library<149>,  Up: Python 3 10 0 alpha 1

1.24.49.32 Documentation
........................

   - bpo-41428(1): Add documentation for PEP 604(2) (Allow writing union
     types as ‘X | Y’).

   - bpo-41774(3): In Programming FAQ «Sequences (Tuples/Lists)»
     section, add «How do you remove multiple items from a list».

   - bpo-35293(4): Fix RemovedInSphinx40Warning when building the
     documentation.  Patch by Donghee Na.

   - bpo-37149(5): Change Shipman tkinter doc link from archive.org to
     TkDocs.  (The doc has been removed from the NMT server.)  The new
     link responds much faster and includes a short explanatory note.

   - bpo-41726(6): Update the refcounts info of
     ‘PyType_FromModuleAndSpec’.

   - bpo-41624(7): Fix the signature of *note typing.Coroutine: 1d19.

   - bpo-40204(8): Enable Sphinx 3.2 ‘c_allow_pre_v3’ option and disable
     ‘c_warn_on_allowed_pre_v3’ option to make the documentation
     compatible with Sphinx 2 and Sphinx 3.

   - bpo-41045(9): Add documentation for debug feature of f-strings.

   - bpo-41314(10): Changed the release when ‘from __future__ import
     annotations’ becomes the default from ‘4.0’ to ‘3.10’ (following a
     change in PEP 563).

   - bpo-40979(11): Refactored typing.rst, arranging more than 70
     classes, functions, and decorators into new sub-sections.

   - bpo-40552(12): Fix in tutorial section 4.2.  Code snippet is now
     correct.

   - bpo-39883(13): Make code, examples, and recipes in the Python
     documentation be licensed under the more permissive BSD0 license in
     addition to the existing Python 2.0 license.

   - bpo-37703(14): Updated Documentation to comprehensively elaborate
     on the behaviour of gather.cancel()

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41428

   (2) https://peps.python.org/pep-0604/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41774

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35293

   (5) https://bugs.python.org/issue?@action=redirect&bpo=37149

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41726

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41624

   (8) https://bugs.python.org/issue?@action=redirect&bpo=40204

   (9) https://bugs.python.org/issue?@action=redirect&bpo=41045

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41314

   (11) https://bugs.python.org/issue?@action=redirect&bpo=40979

   (12) https://bugs.python.org/issue?@action=redirect&bpo=40552

   (13) https://bugs.python.org/issue?@action=redirect&bpo=39883

   (14) https://bugs.python.org/issue?@action=redirect&bpo=37703


File: python.info,  Node: Tests<43>,  Next: Build<50>,  Prev: Documentation<43>,  Up: Python 3 10 0 alpha 1

1.24.49.33 Tests
................

   - bpo-41939(1): Fix test_site.test_license_exists_at_url(): call
     ‘urllib.request.urlcleanup()’ to reset the global
     ‘urllib.request._opener’.  Patch by Victor Stinner.

   - bpo-41731(2): Make test_cmd_line_script pass with option “-vv”.

   - bpo-41602(3): Add tests for SIGINT handling in the runpy module.

   - bpo-41521(4): *note test.support: ea.: Rename ‘blacklist’ parameter
     of *note check__all__(): 1d1b. to ‘not_exported’.

   - bpo-41477(5): Make ctypes optional in test_genericalias.

   - bpo-41085(6): Fix integer overflow in the *note
     array.array.index(): 9e3. method on 64-bit Windows for index larger
     than ‘2**31’.

   - bpo-41069(7): ‘test.support.TESTFN’ and the current directory for
     tests when run via ‘test.regrtest’ contain now non-ascii characters
     if possible.

   - bpo-38377(8): On Linux, skip tests using multiprocessing if the
     current user cannot create a file in ‘/dev/shm/’ directory.  Add
     the *note skip_if_broken_multiprocessing_synchronize(): 1d1c.
     function to the *note test.support: ea. module.

   - bpo-41009(9): Fix use of
     ‘support.require_{linux|mac|freebsd}_version()’ decorators as class
     decorator.

   - bpo-41003(10): Fix ‘test_copyreg’ when ‘numpy’ is installed:
     ‘test.pickletester’ now saves/restores warnings filters when
     importing ‘numpy’, to ignore filters installed by ‘numpy’.

   - bpo-40964(11): Disable remote *note imaplib: 78. tests, host
     cyrus.andrew.cmu.edu is blocking incoming connections.

   - bpo-40927(12): Fix test_binhex when run twice: it now uses
     import_fresh_module() to ensure that it raises DeprecationWarning
     each time.

   - bpo-17258(13): Skip some *note multiprocessing: 98. tests when MD5
     hash digest is blocked.

   - bpo-31904(14): Increase LOOPBACK_TIMEOUT to 10 for VxWorks RTOS.

   - bpo-38169(15): Increase code coverage for SharedMemory and
     ShareableList

   - bpo-34401(16): Make test_gdb properly run on HP-UX. Patch by
     Michael Osipov.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41939

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41731

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41602

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41521

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41477

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41085

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41069

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38377

   (9) https://bugs.python.org/issue?@action=redirect&bpo=41009

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41003

   (11) https://bugs.python.org/issue?@action=redirect&bpo=40964

   (12) https://bugs.python.org/issue?@action=redirect&bpo=40927

   (13) https://bugs.python.org/issue?@action=redirect&bpo=17258

   (14) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (15) https://bugs.python.org/issue?@action=redirect&bpo=38169

   (16) https://bugs.python.org/issue?@action=redirect&bpo=34401


File: python.info,  Node: Build<50>,  Next: Windows<43>,  Prev: Tests<43>,  Up: Python 3 10 0 alpha 1

1.24.49.34 Build
................

   - bpo-38249(1): Update *note Py_UNREACHABLE: db0. to use
     __builtin_unreachable() if only the compiler is able to use it.
     Patch by Donghee Na.

   - bpo-41617(2): Fix ‘pycore_bitutils.h’ header file to support old
     clang versions: ‘__builtin_bswap16()’ is not available in LLVM
     clang 3.0.

   - bpo-40204(3): Pin Sphinx version to 2.3.1 in ‘Doc/Makefile’.

   - bpo-36020(4): The C99 functions ‘snprintf()’ and ‘vsnprintf()’ are
     now required to build Python.

   - bpo-40684(5): ‘make install’ now uses the ‘PLATLIBDIR’ variable for
     the destination ‘lib-dynload/’ directory when ‘./configure
     --with-platlibdir’ is used.

   - bpo-40683(6): Fixed an issue where the *note zoneinfo: 13a. module
     and its tests were not included when Python is installed with
     ‘make’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38249

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41617

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40204

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36020

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40684

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40683


File: python.info,  Node: Windows<43>,  Next: macOS<33>,  Prev: Build<50>,  Up: Python 3 10 0 alpha 1

1.24.49.35 Windows
..................

   - bpo-41744(1): Fixes automatic import of props file when using the
     Nuget package.

   - bpo-41627(2): The user site directory for 32-bit now includes a
     ‘-32’ suffix to distinguish it from the 64-bit interpreter’s
     directory.

   - bpo-41526(3): Fixed layout of final page of the installer by
     removing the special thanks to Mark Hammond (with his permission).

   - bpo-41492(4): Fixes the description that appears in UAC prompts.

   - bpo-40948(5): Improve post-install message to direct people to the
     «py» command.

   - bpo-41412(6): The installer will now fail to install on Windows 7
     and Windows 8.  Further, the UCRT dependency is now always
     downloaded on demand.

   - bpo-40741(7): Update Windows release to include SQLite 3.32.3.

   - bpo-41142(8): ‘msilib’ now supports creating CAB files with
     non-ASCII file path and adding files with non-ASCII file path to
     them.

   - bpo-41074(9): Fixed support of non-ASCII names in functions
     ‘msilib.OpenDatabase()’ and ‘msilib.init_database()’ and non-ASCII
     SQL in method ‘msilib.Database.OpenView()’.

   - bpo-41039(10): Stable ABI redirection DLL (python3.dll) now uses
     ‘#pragma comment(linker)’ for re-exporting.

   - bpo-40164(11): Updates Windows OpenSSL to 1.1.1g

   - bpo-39631(12): Changes the registered MIME type for ‘.py’ files on
     Windows to ‘text/x-python’ instead of ‘text/plain’.

   - bpo-40677(13): Manually define IO_REPARSE_TAG_APPEXECLINK in case
     some old Windows SDK doesn’t have it.

   - bpo-37556(14): Extend py.exe help to mention overrides via venv,
     shebang, environmental variables & ini files.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41744

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41627

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41526

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41492

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40948

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41412

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40741

   (8) https://bugs.python.org/issue?@action=redirect&bpo=41142

   (9) https://bugs.python.org/issue?@action=redirect&bpo=41074

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41039

   (11) https://bugs.python.org/issue?@action=redirect&bpo=40164

   (12) https://bugs.python.org/issue?@action=redirect&bpo=39631

   (13) https://bugs.python.org/issue?@action=redirect&bpo=40677

   (14) https://bugs.python.org/issue?@action=redirect&bpo=37556


File: python.info,  Node: macOS<33>,  Next: IDLE<26>,  Prev: Windows<43>,  Up: Python 3 10 0 alpha 1

1.24.49.36 macOS
................

   - bpo-41557(1): Update macOS installer to use SQLite 3.33.0.

   - bpo-39580(2): Avoid opening Finder window if running installer from
     the command line.  Patch contributed by Rick Heil.

   - bpo-41100(3): Fix configure error when building on macOS 11.  Note
     that the current Python release was released shortly after the
     first developer preview of macOS 11 (Big Sur); there are other
     known issues with building and running on the developer preview.
     Big Sur is expected to be fully supported in a future bugfix
     release of Python 3.8.x and with 3.9.0.

   - bpo-40741(4): Update macOS installer to use SQLite 3.32.3.

   - bpo-41005(5): fixed an XDG settings issue not allowing macos to
     open browser in webbrowser.py

   - bpo-40741(6): Update macOS installer to use SQLite 3.32.2.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41557

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39580

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41100

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40741

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41005

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40741


File: python.info,  Node: IDLE<26>,  Next: C API<45>,  Prev: macOS<33>,  Up: Python 3 10 0 alpha 1

1.24.49.37 IDLE
...............

   - bpo-41775(1): Use “IDLE Shell” as shell title

   - bpo-35764(2): Rewrite the Calltips doc section.

   - bpo-40181(3): In calltips, stop reminding that “/” marks the end of
     positional-only arguments.

   - bpo-41468(4): Improve IDLE run crash error message (which users
     should never see).

   - bpo-41373(5): Save files loaded with no line ending, as when blank,
     or different line endings, by setting its line ending to the system
     default.  Fix regression in 3.8.4 and 3.9.0b4.

   - bpo-41300(6): Save files with non-ascii chars.  Fix regression
     released in 3.9.0b4 and 3.8.4.

   - bpo-37765(7): Add keywords to module name completion list.  Rewrite
     Completions section of IDLE doc.

   - bpo-41152(8): The encoding of ‘stdin’, ‘stdout’ and ‘stderr’ in
     IDLE is now always UTF-8.

   - bpo-41144(9): Make Open Module open a special module such as
     os.path.

   - bpo-39885(10): Make context menu Cut and Copy work again when
     right-clicking within a selection.

   - bpo-40723(11): Make test_idle pass when run after import.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41775

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35764

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40181

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41468

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41373

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41300

   (7) https://bugs.python.org/issue?@action=redirect&bpo=37765

   (8) https://bugs.python.org/issue?@action=redirect&bpo=41152

   (9) https://bugs.python.org/issue?@action=redirect&bpo=41144

   (10) https://bugs.python.org/issue?@action=redirect&bpo=39885

   (11) https://bugs.python.org/issue?@action=redirect&bpo=40723


File: python.info,  Node: C API<45>,  Prev: IDLE<26>,  Up: Python 3 10 0 alpha 1

1.24.49.38 C API
................

   - bpo-41936(1): Removed undocumented macros ‘Py_ALLOW_RECURSION’ and
     ‘Py_END_ALLOW_RECURSION’ and the ‘recursion_critical’ field of the
     *note PyInterpreterState: abc. structure.

   - bpo-41692(2): The ‘PyUnicode_InternImmortal()’ function is now
     deprecated and will be removed in Python 3.12: use *note
     PyUnicode_InternInPlace(): ab0. instead.  Patch by Victor Stinner.

   - bpo-41842(3): Add *note PyCodec_Unregister(): a99. function to
     unregister a codec search function.

   - bpo-41834(4): Remove the ‘_Py_CheckRecursionLimit’ variable: it has
     been replaced by ‘ceval.recursion_limit’ of the *note
     PyInterpreterState: abc. structure.  Patch by Victor Stinner.

   - bpo-41689(5): Types created with *note PyType_FromSpec(): 79e. now
     make any signature in their ‘tp_doc’ slot accessible from
     ‘__text_signature__’.

   - bpo-41524(6): Fix bug in *note PyOS_mystrnicmp(): 1d22. and *note
     PyOS_mystricmp(): 1d23. that incremented pointers beyond the end of
     a string.

   - bpo-41324(7): Add a minimal decimal capsule API. The API supports
     fast conversions between Decimals up to 38 digits and their triple
     representation as a C struct.

   - bpo-30155(8): Add *note PyDateTime_DATE_GET_TZINFO(): a97. and
     *note PyDateTime_TIME_GET_TZINFO(): a98. macros for accessing the
     ‘tzinfo’ attributes of *note datetime.datetime: 4e3. and *note
     datetime.time: 1fb. objects.

   - bpo-40170(9): Revert *note PyType_HasFeature(): 1d24. change: it
     reads again directly the *note PyTypeObject.tp_flags: 1c59. member
     when the limited C API is not used, rather than always calling
     *note PyType_GetFlags(): 1d25. which hides implementation details.

   - bpo-41123(10): Remove ‘PyUnicode_AsUnicodeCopy’.

   - bpo-41123(11): Removed ‘PyLong_FromUnicode()’.

   - bpo-41123(12): Removed ‘PyUnicode_GetMax()’.

   - bpo-41123(13): Removed ‘Py_UNICODE_str*’ functions manipulating
     ‘Py_UNICODE*’ strings.

   - bpo-41103(14): ‘PyObject_AsCharBuffer()’,
     ‘PyObject_AsReadBuffer()’, ‘PyObject_CheckReadBuffer()’, and
     ‘PyObject_AsWriteBuffer()’ are removed.  Please migrate to new
     buffer protocol; *note PyObject_GetBuffer(): 63a. and *note
     PyBuffer_Release(): 63b.

   - bpo-36346(15): Raises DeprecationWarning for
     ‘PyUnicode_FromUnicode(NULL, size)’ and
     ‘PyUnicode_FromStringAndSize(NULL, size)’ with ‘size > 0’.

   - bpo-36346(16): Mark ‘Py_UNICODE_COPY’, ‘Py_UNICODE_FILL’,
     ‘PyUnicode_WSTR_LENGTH’, ‘PyUnicode_FromUnicode’,
     ‘PyUnicode_AsUnicode’, and ‘PyUnicode_AsUnicodeAndSize’ as
     deprecated in C. Remove ‘Py_UNICODE_MATCH’ which was deprecated and
     broken since Python 3.3.

   - bpo-40989(17): The *note PyObject_INIT(): 1d26. and *note
     PyObject_INIT_VAR(): 1d27. macros become aliases to, respectively,
     *note PyObject_Init(): c62. and *note PyObject_InitVar(): 1d28.
     functions.

   - bpo-36020(18): On Windows, ‘#include "pyerrors.h"’ no longer
     defines ‘snprintf’ and ‘vsnprintf’ macros.

   - bpo-40943(19): The ‘PY_SSIZE_T_CLEAN’ macro must now be defined to
     use *note PyArg_ParseTuple(): 3c1. and *note Py_BuildValue(): 3c2.
     formats which use ‘#’: ‘es#’, ‘et#’, ‘s#’, ‘u#’, ‘y#’, ‘z#’, ‘U#’
     and ‘Z#’.  See *note Parsing arguments and building values: 3d5.
     and the PEP 353(20).

   - bpo-40910(21): Export explicitly the *note Py_GetArgcArgv(): 1d29.
     function to the C API and document the function.  Previously, it
     was exported implicitly which no longer works since Python is built
     with ‘-fvisibility=hidden’.

   - bpo-40724(22): Allow defining buffer slots in type specs.

   - bpo-40679(23): Fix a ‘_PyEval_EvalCode()’ crash if 'qualname'
     argument is NULL.

   - bpo-40839(24): Calling *note PyDict_GetItem(): 628. without *note
     GIL: 164. held had been allowed for historical reason.  It is no
     longer allowed.

   - bpo-40826(25): *note PyOS_InterruptOccurred(): 1d2a. now fails with
     a fatal error if it is called with the GIL released.

   - bpo-40792(26): The result of *note PyNumber_Index(): a95. now
     always has exact type *note int: 19b.  Previously, the result could
     have been an instance of a subclass of ‘int’.

   - bpo-39573(27): Convert *note Py_REFCNT(): 2cf. and *note Py_SIZE():
     986. macros to static inline functions.  They cannot be used as
     l-value anymore: use *note Py_SET_REFCNT(): aaa. and *note
     Py_SET_SIZE(): 987. to set an object reference count and size.
     This change is backward incompatible on purpose, to prepare the C
     API for an opaque *note PyObject: 5df. structure.

   - bpo-40703(28): The PyType_FromSpec*() functions no longer overwrite
     the type’s «__module__» attribute if it is set via «Py_tp_members»
     or «Py_tp_getset».

   - bpo-39583(29): Remove superfluous «extern C» declarations from
     ‘Include/cpython/*.h’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=41936

   (2) https://bugs.python.org/issue?@action=redirect&bpo=41692

   (3) https://bugs.python.org/issue?@action=redirect&bpo=41842

   (4) https://bugs.python.org/issue?@action=redirect&bpo=41834

   (5) https://bugs.python.org/issue?@action=redirect&bpo=41689

   (6) https://bugs.python.org/issue?@action=redirect&bpo=41524

   (7) https://bugs.python.org/issue?@action=redirect&bpo=41324

   (8) https://bugs.python.org/issue?@action=redirect&bpo=30155

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (10) https://bugs.python.org/issue?@action=redirect&bpo=41123

   (11) https://bugs.python.org/issue?@action=redirect&bpo=41123

   (12) https://bugs.python.org/issue?@action=redirect&bpo=41123

   (13) https://bugs.python.org/issue?@action=redirect&bpo=41123

   (14) https://bugs.python.org/issue?@action=redirect&bpo=41103

   (15) https://bugs.python.org/issue?@action=redirect&bpo=36346

   (16) https://bugs.python.org/issue?@action=redirect&bpo=36346

   (17) https://bugs.python.org/issue?@action=redirect&bpo=40989

   (18) https://bugs.python.org/issue?@action=redirect&bpo=36020

   (19) https://bugs.python.org/issue?@action=redirect&bpo=40943

   (20) https://peps.python.org/pep-0353/

   (21) https://bugs.python.org/issue?@action=redirect&bpo=40910

   (22) https://bugs.python.org/issue?@action=redirect&bpo=40724

   (23) https://bugs.python.org/issue?@action=redirect&bpo=40679

   (24) https://bugs.python.org/issue?@action=redirect&bpo=40839

   (25) https://bugs.python.org/issue?@action=redirect&bpo=40826

   (26) https://bugs.python.org/issue?@action=redirect&bpo=40792

   (27) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (28) https://bugs.python.org/issue?@action=redirect&bpo=40703

   (29) https://bugs.python.org/issue?@action=redirect&bpo=39583


File: python.info,  Node: Python 3 9 0 beta 1,  Next: Python 3 9 0 alpha 6,  Prev: Python 3 10 0 alpha 1,  Up: Changelog

1.24.50 Python 3.9.0 beta 1
---------------------------

'Release date: 2020-05-19'

* Menu:

* Security: Security<37>.
* Core and Builtins: Core and Builtins<147>.
* Library: Library<150>.
* Documentation: Documentation<44>.
* Tests: Tests<44>.
* Build: Build<51>.
* Windows: Windows<44>.
* macOS: macOS<34>.
* Tools/Demos: Tools/Demos<30>.
* C API: C API<46>.


File: python.info,  Node: Security<37>,  Next: Core and Builtins<147>,  Up: Python 3 9 0 beta 1

1.24.50.1 Security
..................

   - bpo-40501(1): *note uuid: 116. no longer uses *note ctypes: 2e. to
     load ‘libuuid’ or ‘rpcrt4.dll’ at runtime.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40501


File: python.info,  Node: Core and Builtins<147>,  Next: Library<150>,  Prev: Security<37>,  Up: Python 3 9 0 beta 1

1.24.50.2 Core and Builtins
...........................

   - bpo-40663(1): Correctly generate annotations where parentheses are
     omitted but required (e.g: ‘Type[(str, int, *other))]’.

   - bpo-40596(2): Fixed *note str.isidentifier(): 1d2e. for
     non-canonicalized strings containing non-BMP characters on Windows.

   - bpo-40593(3): Improved syntax errors for invalid characters in
     source code.

   - bpo-40585(4): Fixed a bug when using *note
     codeop.compile_command(): 1b3b. that was causing exceptions to be
     swallowed with the new parser.  Patch by Pablo Galindo

   - bpo-40566(5): Apply PEP 573(6) to *note abc: 4.

   - bpo-40502(7): Initialize ‘n->n_col_offset’.  (Patch by Joannah
     Nanjekye)

   - bpo-40527(8): Fix command line argument parsing: no longer write
     errors multiple times into stderr.

   - bpo-1635741(9): Port *note errno: 5b. to multiphase initialization
     ( PEP 489(10)).

   - bpo-40523(11): Add pass-throughs for *note hash(): 802. and *note
     reversed(): a67. to *note weakref.proxy: c48. objects.  Patch by
     Pablo Galindo.

   - bpo-1635741(12): Port *note syslog: e2. to multiphase
     initialization ( PEP 489(13)).

   - bpo-40246(14): Reporting a specialised error message for invalid
     string prefixes, which was introduced in bpo-40246(15), is being
     reverted due to backwards compatibility concerns for strings that
     immediately follow a reserved keyword without whitespace between
     them.  Constructs like ‘bg="#d00" if clear else"#fca"’ were failing
     to parse, which is not an acceptable breakage on such short notice.

   - bpo-40417(16): Fix imp module deprecation warning when
     PyImport_ReloadModule is called.  Patch by Robert Rouhani.

   - bpo-40408(17): Fixed support of nested type variables in
     GenericAlias (e.g.  ‘list[list[T]]’).

   - bpo-1635741(18): Port _stat module to multiphase initialization (
     PEP 489(19)).

   - bpo-29587(20): Enable implicit exception chaining when calling
     *note generator.throw(): 71d.

   - bpo-40328(21): Add tools for generating mappings headers for
     CJKCodecs.

   - bpo-40228(22): Setting frame.f_lineno is now robust w.r.t.  changes
     in the source-to-bytecode compiler

   - bpo-38880(23): Added the ability to list interpreters associated
     with channel ends in the internal subinterpreters module.

   - bpo-37986(24): Improve performance of *note PyLong_FromDouble():
     b3e. for values that fit into long.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40663

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40596

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40593

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40585

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40566

   (6) https://peps.python.org/pep-0573/

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40502

   (8) https://bugs.python.org/issue?@action=redirect&bpo=40527

   (9) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (10) https://peps.python.org/pep-0489/

   (11) https://bugs.python.org/issue?@action=redirect&bpo=40523

   (12) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (13) https://peps.python.org/pep-0489/

   (14) https://bugs.python.org/issue?@action=redirect&bpo=40246

   (15) https://bugs.python.org/issue?@action=redirect&bpo=40246

   (16) https://bugs.python.org/issue?@action=redirect&bpo=40417

   (17) https://bugs.python.org/issue?@action=redirect&bpo=40408

   (18) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (19) https://peps.python.org/pep-0489/

   (20) https://bugs.python.org/issue?@action=redirect&bpo=29587

   (21) https://bugs.python.org/issue?@action=redirect&bpo=40328

   (22) https://bugs.python.org/issue?@action=redirect&bpo=40228

   (23) https://bugs.python.org/issue?@action=redirect&bpo=38880

   (24) https://bugs.python.org/issue?@action=redirect&bpo=37986


File: python.info,  Node: Library<150>,  Next: Documentation<44>,  Prev: Core and Builtins<147>,  Up: Python 3 9 0 beta 1

1.24.50.3 Library
.................

   - bpo-40662(1): Fixed *note ast.get_source_segment(): bcd. for ast
     nodes that have incomplete location information.  Patch by Irit
     Katriel.

   - bpo-40665(2): Convert *note bisect: 12. to use Argument Clinic.

   - bpo-40536(3): Added the *note available_timezones(): 1d30. function
     to the *note zoneinfo: 13a. module.  Patch by Paul Ganssle.

   - bpo-40645(4): The *note hmac.HMAC: d35. exposes internal
     implementation details.  The attributes ‘digest_cons’, ‘inner’, and
     ‘outer’ are deprecated and will be removed in the future.

   - bpo-40645(5): The internal module ‘_hashlib’ wraps and exposes
     OpenSSL’s HMAC API. The new code will be used in Python 3.10 after
     the internal implementation details of the pure Python HMAC module
     are no longer part of the public API.

   - bpo-40637(6): Builtin hash modules can now be disabled or
     selectively enabled with ‘configure
     --with-builtin-hashlib-hashes=sha3,blake1’ or
     ‘--without-builtin-hashlib-hashes’.

   - bpo-37630(7): The *note hashlib: 6c. module can now use SHA3 hashes
     and SHAKE XOF from OpenSSL when available.

   - bpo-40479(8): The *note hashlib: 6c. now compiles with OpenSSL
     3.0.0-alpha2.

   - bpo-40257(9): Revert changes to *note inspect.getdoc(): bef.

   - bpo-40607(10): When cancelling a task due to timeout, *note
     asyncio.wait_for(): 816. will now propagate the exception if an
     error happens during cancellation.  Patch by Roman Skurikhin.

   - bpo-40612(11): Fix edge cases in SyntaxError formatting.  If the
     offset is <= 0, no caret is printed.  If the offset is > line
     length, the caret is printed pointing just after the last
     character.

   - bpo-40597(12): If text content lines are longer than
     policy.max_line_length, always use a content-encoding to make sure
     they are wrapped.

   - bpo-40571(13): Added functools.cache() as a simpler, more
     discoverable way to access the unbounded cache variant of
     lru_cache(maxsize=None).

   - bpo-40503(14): PEP 615(15), the *note zoneinfo: 13a. module.  Adds
     support for the IANA time zone database.

   - bpo-40397(16): Removed attributes ‘__args__’ and ‘__parameters__’
     from special generic aliases like ‘typing.List’ (not subscripted).

   - bpo-40549(17): Convert posixmodule.c («posix» or «nt» module) to
     the multiphase initialization (PEP 489).

   - bpo-31033(18): Add a ‘msg’ argument to ‘Future.cancel()’ and
     ‘Task.cancel()’.

   - bpo-40541(19): Added an optional 'counts' parameter to
     random.sample().

   - bpo-40515(20): The *note ssl: d5. and *note hashlib: 6c. modules
     now actively check that OpenSSL is build with thread support.
     Python 3.7.0 made thread support mandatory and no longer works
     safely with a no-thread builds.

   - bpo-31033(21): When a *note asyncio.Task: 1c7. is cancelled, the
     exception traceback now chains all the way back to where the task
     was first interrupted.

   - bpo-40504(22): *note functools.lru_cache(): be4. objects can now be
     the targets of weakrefs.

   - bpo-40559(23): Fix possible memory leak in the C implementation of
     *note asyncio.Task: 1c7.

   - bpo-40480(24): ‘fnmatch.fnmatch()’ could take exponential time in
     the presence of multiple ‘*’ pattern characters.  This was repaired
     by generating more elaborate regular expressions to avoid futile
     backtracking.

   - bpo-40495(25): *note compileall: 21. is now able to use hardlinks
     to prevent duplicates in a case when ‘.pyc’ files for different
     optimization levels have the same content.

   - bpo-40457(26): The ssl module now support OpenSSL builds without
     TLS 1.0 and 1.1 methods.

   - bpo-40355(27): Improve error reporting in *note ast.literal_eval():
     e14. in the presence of malformed *note ast.Dict: 1d31. nodes
     instead of silently ignoring any non-conforming elements.  Patch by
     Curtis Bucher.

   - bpo-40465(28): Deprecated the optional 'random' argument to
     'random.shuffle()'.

   - bpo-40459(29): *note platform.win32_ver(): 1d32. now produces
     correct 'ptype' strings instead of empty strings.

   - bpo-39435(30): The first argument of *note pickle.loads(): f0f. is
     now positional-only.

   - bpo-39305(31): Update ‘nntplib’ to merge ‘nntplib.NNTP’ and
     ‘nntplib._NNTPBase’.  Patch by Donghee Na.

   - bpo-32494(32): Update *note dbm.gnu: 37. to use gdbm_count if
     possible when calling *note len(): 841.  Patch by Donghee Na.

   - bpo-40453(33): Add ‘isolated=True’ keyword-only parameter to
     ‘_xxsubinterpreters.create()’.  An isolated subinterpreter cannot
     spawn threads, spawn a child process or call ‘os.fork()’.

   - bpo-40286(34): Remove ‘_random.Random.randbytes()’: the C
     implementation of ‘randbytes()’.  Implement the method in Python to
     ease subclassing: ‘randbytes()’ now directly reuses
     ‘getrandbits()’.

   - bpo-40394(35): Added default arguments to *note
     difflib.SequenceMatcher.find_longest_match(): 1d33.

   - bpo-39995(36): Fix a race condition in
     concurrent.futures._ThreadWakeup: access to _ThreadWakeup is now
     protected with the shutdown lock.

   - bpo-30966(37): ‘Process.shutdown(wait=True)’ of *note
     concurrent.futures: 24. now closes explicitly the result queue.

   - bpo-30966(38): Add a new *note close(): b13. method to the *note
     SimpleQueue: b12. class to explicitly close the queue.

   - bpo-39966(39): Revert bpo-25597(40).  *note
     unittest.mock.MagicMock: 1091. with wraps” set uses default return
     values for magic methods.

   - bpo-39791(41): Added ‘files()’ function to importlib.resources with
     support for subdirectories in package data, matching backport in
     importlib_resources 1.5.

   - bpo-40375(42): *note imaplib.IMAP4.unselect(): b05. is added.
     Patch by Donghee Na.

   - bpo-40389(43): ‘repr()’ now returns ‘typing.Optional[T]’ when
     called for ‘typing.Union’ of two types, one of which is ‘NoneType’.

   - bpo-40291(44): Add support for CAN_J1939 sockets (available on
     Linux 5.4+)

   - bpo-40273(45): *note types.MappingProxyType: 699. is now
     reversible.

   - bpo-39075(46): The repr for *note types.SimpleNamespace: 4e6. is
     now insertion ordered rather than alphabetical.

   - bpo-40192(47): On AIX, *note thread_time(): b32. is now implemented
     with ‘thread_cputime()’ which has nanosecond resolution, rather
     than ‘clock_gettime(CLOCK_THREAD_CPUTIME_ID)’ which has a
     resolution of 10 milliseconds.  Patch by Batuhan Taskaya.

   - bpo-40025(48): Raise TypeError when _generate_next_value_ is
     defined after members.  Patch by Ethan Onstott.

   - bpo-39058(49): In the argparse module, the repr for Namespace() and
     other argument holders now displayed in the order attributes were
     added.  Formerly, it displayed in alphabetical order even though
     argument order is preserved the user visible parts of the module.

   - bpo-24416(50): The ‘isocalendar()’ methods of *note datetime.date:
     1fa. and *note datetime.datetime: 4e3. now return a *note named
     tuple: 85f. instead of a *note tuple: 614.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40662

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40665

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40536

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40645

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40645

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40637

   (7) https://bugs.python.org/issue?@action=redirect&bpo=37630

   (8) https://bugs.python.org/issue?@action=redirect&bpo=40479

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40257

   (10) https://bugs.python.org/issue?@action=redirect&bpo=40607

   (11) https://bugs.python.org/issue?@action=redirect&bpo=40612

   (12) https://bugs.python.org/issue?@action=redirect&bpo=40597

   (13) https://bugs.python.org/issue?@action=redirect&bpo=40571

   (14) https://bugs.python.org/issue?@action=redirect&bpo=40503

   (15) https://peps.python.org/pep-0615/

   (16) https://bugs.python.org/issue?@action=redirect&bpo=40397

   (17) https://bugs.python.org/issue?@action=redirect&bpo=40549

   (18) https://bugs.python.org/issue?@action=redirect&bpo=31033

   (19) https://bugs.python.org/issue?@action=redirect&bpo=40541

   (20) https://bugs.python.org/issue?@action=redirect&bpo=40515

   (21) https://bugs.python.org/issue?@action=redirect&bpo=31033

   (22) https://bugs.python.org/issue?@action=redirect&bpo=40504

   (23) https://bugs.python.org/issue?@action=redirect&bpo=40559

   (24) https://bugs.python.org/issue?@action=redirect&bpo=40480

   (25) https://bugs.python.org/issue?@action=redirect&bpo=40495

   (26) https://bugs.python.org/issue?@action=redirect&bpo=40457

   (27) https://bugs.python.org/issue?@action=redirect&bpo=40355

   (28) https://bugs.python.org/issue?@action=redirect&bpo=40465

   (29) https://bugs.python.org/issue?@action=redirect&bpo=40459

   (30) https://bugs.python.org/issue?@action=redirect&bpo=39435

   (31) https://bugs.python.org/issue?@action=redirect&bpo=39305

   (32) https://bugs.python.org/issue?@action=redirect&bpo=32494

   (33) https://bugs.python.org/issue?@action=redirect&bpo=40453

   (34) https://bugs.python.org/issue?@action=redirect&bpo=40286

   (35) https://bugs.python.org/issue?@action=redirect&bpo=40394

   (36) https://bugs.python.org/issue?@action=redirect&bpo=39995

   (37) https://bugs.python.org/issue?@action=redirect&bpo=30966

   (38) https://bugs.python.org/issue?@action=redirect&bpo=30966

   (39) https://bugs.python.org/issue?@action=redirect&bpo=39966

   (40) https://bugs.python.org/issue?@action=redirect&bpo=25597

   (41) https://bugs.python.org/issue?@action=redirect&bpo=39791

   (42) https://bugs.python.org/issue?@action=redirect&bpo=40375

   (43) https://bugs.python.org/issue?@action=redirect&bpo=40389

   (44) https://bugs.python.org/issue?@action=redirect&bpo=40291

   (45) https://bugs.python.org/issue?@action=redirect&bpo=40273

   (46) https://bugs.python.org/issue?@action=redirect&bpo=39075

   (47) https://bugs.python.org/issue?@action=redirect&bpo=40192

   (48) https://bugs.python.org/issue?@action=redirect&bpo=40025

   (49) https://bugs.python.org/issue?@action=redirect&bpo=39058

   (50) https://bugs.python.org/issue?@action=redirect&bpo=24416


File: python.info,  Node: Documentation<44>,  Next: Tests<44>,  Prev: Library<150>,  Up: Python 3 9 0 beta 1

1.24.50.4 Documentation
.......................

   - bpo-34790(1): Add version of removal for explicit passing of coros
     to ‘asyncio.wait()’”s documentation

   - bpo-40561(2): Provide docstrings for webbrowser open functions.

   - bpo-40499(3): Mention that *note asyncio.wait(): 6a8. requires a
     non-empty set of awaitables.

   - bpo-39705(4): Tutorial example for sorted() in the Loop Techniques
     section is given a better explanation.  Also a new example is
     included to explain sorted()”s basic behavior.

   - bpo-39435(5): Fix an incorrect signature for *note pickle.loads():
     f0f. in the docs

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34790

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40561

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40499

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39705

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39435


File: python.info,  Node: Tests<44>,  Next: Build<51>,  Prev: Documentation<44>,  Up: Python 3 9 0 beta 1

1.24.50.5 Tests
...............

   - bpo-40055(1): distutils.tests now saves/restores warnings filters
     to leave them unchanged.  Importing tests imports docutils which
     imports pkg_resources which adds a warnings filter.

   - bpo-40436(2): test_gdb and test.pythoninfo now check gdb command
     exit code.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40055

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40436


File: python.info,  Node: Build<51>,  Next: Windows<44>,  Prev: Tests<44>,  Up: Python 3 9 0 beta 1

1.24.50.6 Build
...............

   - bpo-40653(1): Move _dirnameW out of HAVE_SYMLINK to fix a potential
     compiling issue.

   - bpo-40514(2): Add ‘--with-experimental-isolated-subinterpreters’
     build option to ‘configure’: better isolate subinterpreters,
     experimental build mode.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40653

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40514


File: python.info,  Node: Windows<44>,  Next: macOS<34>,  Prev: Build<51>,  Up: Python 3 9 0 beta 1

1.24.50.7 Windows
.................

   - bpo-40650(1): Include winsock2.h in pytime.c for timeval.

   - bpo-40458(2): Increase reserved stack space to prevent overflow
     crash on Windows.

   - bpo-39148(3): Add IPv6 support to *note asyncio: b. datagram
     endpoints in ProactorEventLoop.  Change the raised exception for
     unknown address families to ValueError as it’s not coming from
     Windows API.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40650

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40458

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39148


File: python.info,  Node: macOS<34>,  Next: Tools/Demos<30>,  Prev: Windows<44>,  Up: Python 3 9 0 beta 1

1.24.50.8 macOS
...............

   - bpo-34956(1): When building Python on macOS from source, ‘_tkinter’
     now links with non-system Tcl and Tk frameworks if they are
     installed in ‘/Library/Frameworks’, as had been the case on older
     releases of macOS. If a macOS SDK is explicitly configured, by
     using ‘--enable-universalsdk=’ or ‘-isysroot’, only the SDK itself
     is searched.  The default behavior can still be overridden with
     ‘--with-tcltk-includes’ and ‘--with-tcltk-libs’.

   - bpo-35569(2): Expose RFC 3542 IPv6 socket options.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34956

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35569


File: python.info,  Node: Tools/Demos<30>,  Next: C API<46>,  Prev: macOS<34>,  Up: Python 3 9 0 beta 1

1.24.50.9 Tools/Demos
.....................

   - bpo-40479(1): Update multissltest helper to test with latest
     OpenSSL 1.0.2, 1.1.0, 1.1.1, and 3.0.0-alpha.

   - bpo-40431(2): Fix a syntax typo in ‘turtledemo’ that now raises a
     ‘SyntaxError’.

   - bpo-40163(3): Fix multissltest tool.  OpenSSL has changed download
     URL for old releases.  The multissltest tool now tries to download
     from current and old download URLs.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40479

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40431

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40163


File: python.info,  Node: C API<46>,  Prev: Tools/Demos<30>,  Up: Python 3 9 0 beta 1

1.24.50.10 C API
................

   - bpo-39465(1): Remove the ‘_PyUnicode_ClearStaticStrings()’ function
     from the C API.

   - bpo-38787(2): Add PyCFunction_CheckExact() macro for exact type
     checks now that we allow subtypes of PyCFunction, as well as
     PyCMethod_CheckExact() and PyCMethod_Check() for the new PyCMethod
     subtype.

   - bpo-40545(3): Declare ‘_PyErr_GetTopmostException()’ with
     ‘PyAPI_FUNC()’ to properly export the function in the C API. The
     function remains private (‘_Py’) prefix.

   - bpo-40412(4): Nullify inittab_copy during finalization, preventing
     future interpreter initializations in an embedded situation from
     crashing.  Patch by Gregory Szorc.

   - bpo-40429(5): The *note PyThreadState_GetFrame(): 992. function now
     returns a strong reference to the frame.

   - bpo-40428(6): Remove the following functions from the C API. Call
     *note PyGC_Collect(): b87. explicitly to free all free lists.

        * ‘PyAsyncGen_ClearFreeLists()’

        * ‘PyContext_ClearFreeList()’

        * ‘PyDict_ClearFreeList()’

        * ‘PyFloat_ClearFreeList()’

        * ‘PyFrame_ClearFreeList()’

        * ‘PyList_ClearFreeList()’

        * ‘PySet_ClearFreeList()’

        * ‘PyTuple_ClearFreeList()’

   - bpo-40421(7): New *note PyFrame_GetBack(): 98a. function: get the
     frame next outer frame.

   - bpo-40421(8): New *note PyFrame_GetCode(): 98e. function: return a
     borrowed reference to the frame code.

   - bpo-40217(9): Ensure that instances of types created with *note
     PyType_FromSpecWithBases(): 79f. will visit its class object when
     traversing references in the garbage collector (implemented as an
     extension of the provided *note tp_traverse: 983.).  Patch by Pablo
     Galindo.

   - bpo-38787(10): Module C state is now accessible from C-defined heap
     type methods ( PEP 573(11)).  Patch by Marcel Plch and Petr
     Viktorin.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39465

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38787

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40545

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40412

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40429

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40428

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40421

   (8) https://bugs.python.org/issue?@action=redirect&bpo=40421

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40217

   (10) https://bugs.python.org/issue?@action=redirect&bpo=38787

   (11) https://peps.python.org/pep-0573/


File: python.info,  Node: Python 3 9 0 alpha 6,  Next: Python 3 9 0 alpha 5,  Prev: Python 3 9 0 beta 1,  Up: Changelog

1.24.51 Python 3.9.0 alpha 6
----------------------------

'Release date: 2020-04-27'

* Menu:

* Security: Security<38>.
* Core and Builtins: Core and Builtins<148>.
* Library: Library<151>.
* Documentation: Documentation<45>.
* Tests: Tests<45>.
* Build: Build<52>.
* Windows: Windows<45>.
* macOS: macOS<35>.
* IDLE: IDLE<27>.
* Tools/Demos: Tools/Demos<31>.
* C API: C API<47>.


File: python.info,  Node: Security<38>,  Next: Core and Builtins<148>,  Up: Python 3 9 0 alpha 6

1.24.51.1 Security
..................

   - bpo-40121(1): Fixes audit events raised on creating a new socket.

   - bpo-39073(2): Disallow CR or LF in email.headerregistry.Address
     arguments to guard against header injection attacks.

   - bpo-39503(3): CVE 2020-8492(4): The *note AbstractBasicAuthHandler:
     1c57. class of the *note urllib.request: 111. module uses an
     inefficient regular expression which can be exploited by an
     attacker to cause a denial of service.  Fix the regex to prevent
     the catastrophic backtracking.  Vulnerability reported by Ben
     Caller and Matt Schwager.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40121

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39073

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39503

   (4) https://www.cve.org/CVERecord?id=CVE-2020-8492


File: python.info,  Node: Core and Builtins<148>,  Next: Library<151>,  Prev: Security<38>,  Up: Python 3 9 0 alpha 6

1.24.51.2 Core and Builtins
...........................

   - bpo-40313(1): Improve the performance of bytes.hex().

   - bpo-40334(2): Switch to a new parser, based on PEG. For more
     details see PEP 617.  To temporarily switch back to the old parser,
     use ‘-X oldparser’ or ‘PYTHONOLDPARSER=1’.  In Python 3.10 we will
     remove the old parser completely, including the ‘parser’ module
     (already deprecated) and anything that depends on it.

   - bpo-40267(3): Fix the tokenizer to display the correct error
     message, when there is a ‘SyntaxError’ on the last input character
     and no newline follows.  It used to be ‘unexpected EOF while
     parsing’, while it should be ‘invalid syntax’.

   - bpo-39522(4): Correctly unparse explicit ‘u’ prefix for strings
     when postponed evaluation for annotations activated.  Patch by
     Batuhan Taskaya.

   - bpo-40246(5): Report a specialized error message, ‘invalid string
     prefix’, when the tokenizer encounters a string with an invalid
     prefix.

   - bpo-40082(6): Fix the signal handler: it now always uses the main
     interpreter, rather than trying to get the current Python thread
     state.

   - bpo-37388(7): str.encode() and str.decode() no longer check the
     encoding and errors in development mode or in debug mode during
     Python finalization.  The codecs machinery can no longer work on
     very late calls to str.encode() and str.decode().

   - bpo-40077(8): Fix possible refleaks in ‘_json’, memo of
     PyScannerObject should be traversed.

   - bpo-37207(9): Speed up calls to ‘dict()’ by using the PEP 590(10)
     ‘vectorcall’ calling convention.

   - bpo-40141(11): Add column and line information to ‘ast.keyword’
     nodes.  Patch by Pablo Galindo.

   - bpo-1635741(12): Port *note resource: c1. to multiphase
     initialization ( PEP 489(13)).

   - bpo-1635741(14): Port *note math: 92. to multiphase initialization
     ( PEP 489(15)).

   - bpo-1635741(16): Port _uuid module to multiphase initialization (
     PEP 489(17)).

   - bpo-40077(18): Convert json module to use *note PyType_FromSpec():
     79e.

   - bpo-40067(19): Improve the error message for multiple star
     expressions in an assignment.  Patch by Furkan Onder

   - bpo-1635741(20): Port _functools module to multiphase
     initialization (PEP 489).  Patch by Paulo Henrique Silva.

   - bpo-1635741(21): Port operator module to multiphase initialization
     (PEP 489).  Patch by Paulo Henrique Silva.

   - bpo-20526(22): Fix *note PyThreadState_Clear(): 1979.
     ‘PyThreadState.frame’ is a borrowed reference, not a strong
     reference: ‘PyThreadState_Clear()’ must not call
     ‘Py_CLEAR(tstate->frame)’.

   - bpo-1635741(23): Port time module to multiphase initialization (
     PEP 489(24)).  Patch by Paulo Henrique Silva.

   - bpo-1635741(25): Port _weakref extension module to multiphase
     initialization ( PEP 489(26)).

   - bpo-40020(27): Fix a leak and subsequent crash in parsetok.c caused
     by realloc misuse on a rare codepath.

   - bpo-39939(28): Added str.removeprefix and str.removesuffix methods
     and corresponding bytes, bytearray, and collections.UserString
     methods to remove affixes from a string if present.  See PEP
     616(29) for a full description.  Patch by Dennis Sweeney.

   - bpo-39481(30): Implement PEP 585.  This supports list[int],
     tuple[str, …] etc.

   - bpo-32894(31): Support unparsing of infinity numbers in postponed
     annotations.  Patch by Batuhan Taşkaya.

   - bpo-37207(32): Speed up calls to ‘list()’ by using the PEP 590(33)
     ‘vectorcall’ calling convention.  Patch by Mark Shannon.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40313

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40334

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40267

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39522

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40246

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40082

   (7) https://bugs.python.org/issue?@action=redirect&bpo=37388

   (8) https://bugs.python.org/issue?@action=redirect&bpo=40077

   (9) https://bugs.python.org/issue?@action=redirect&bpo=37207

   (10) https://peps.python.org/pep-0590/

   (11) https://bugs.python.org/issue?@action=redirect&bpo=40141

   (12) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (13) https://peps.python.org/pep-0489/

   (14) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (15) https://peps.python.org/pep-0489/

   (16) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (17) https://peps.python.org/pep-0489/

   (18) https://bugs.python.org/issue?@action=redirect&bpo=40077

   (19) https://bugs.python.org/issue?@action=redirect&bpo=40067

   (20) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (21) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (22) https://bugs.python.org/issue?@action=redirect&bpo=20526

   (23) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (24) https://peps.python.org/pep-0489/

   (25) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (26) https://peps.python.org/pep-0489/

   (27) https://bugs.python.org/issue?@action=redirect&bpo=40020

   (28) https://bugs.python.org/issue?@action=redirect&bpo=39939

   (29) https://peps.python.org/pep-0616/

   (30) https://bugs.python.org/issue?@action=redirect&bpo=39481

   (31) https://bugs.python.org/issue?@action=redirect&bpo=32894

   (32) https://bugs.python.org/issue?@action=redirect&bpo=37207

   (33) https://peps.python.org/pep-0590/


File: python.info,  Node: Library<151>,  Next: Documentation<45>,  Prev: Core and Builtins<148>,  Up: Python 3 9 0 alpha 6

1.24.51.3 Library
.................

   - bpo-40398(1): *note typing.get_args(): 2ac. now always returns an
     empty tuple for special generic aliases.

   - bpo-40396(2): Functions *note typing.get_origin(): 2ab, *note
     typing.get_args(): 2ac. and *note typing.get_type_hints(): 8c1.
     support now generic aliases like ‘list[int]’.

   - bpo-38061(3): Optimize the *note subprocess: dc. module on FreeBSD
     using ‘closefrom()’.  A single ‘close(fd)’ syscall is cheap, but
     when ‘sysconf(_SC_OPEN_MAX)’ is high, the loop calling ‘close(fd)’
     on each file descriptor can take several milliseconds.

     The workaround on FreeBSD to improve performance was to load and
     mount the fdescfs kernel module, but this is not enabled by
     default.

     Initial patch by Ed Maste (emaste), Conrad Meyer (cem), Kyle Evans
     (kevans) and Kubilay Kocak (koobs):
     ‘https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=242274’

   - bpo-38061(4): On FreeBSD, ‘os.closerange(fd_low, fd_high)’ now
     calls ‘closefrom(fd_low)’ if 'fd_high' is greater than or equal to
     ‘sysconf(_SC_OPEN_MAX)’.

     Initial patch by Ed Maste (emaste), Conrad Meyer (cem), Kyle Evans
     (kevans) and Kubilay Kocak (koobs):
     ‘https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=242274’

   - bpo-40360(5): The ‘lib2to3’ module is pending deprecation due to
     PEP 617(6).

   - bpo-40138(7): Fix the Windows implementation of *note os.waitpid():
     f9c. for exit code larger than ‘INT_MAX >> 8’.  The exit status is
     now interpreted as an unsigned number.

   - bpo-39942(8): Set «__main__» as the default module name when
     «__name__» is missing in *note typing.TypeVar: 487.  Patch by
     Weipeng Hong.

   - bpo-40275(9): The *note logging: 8b. package is now imported lazily
     in *note unittest: 10c. only when the *note assertLogs(): a5b.
     assertion is used.

   - bpo-40275(10): The *note asyncio: b. package is now imported lazily
     in *note unittest: 10c. only when the *note
     IsolatedAsyncioTestCase: 361. class is used.

   - bpo-40330(11): In ‘ShareableList.__setitem__()’, check the size of
     a new string item after encoding it to utf-8, not before.

   - bpo-40148(12): Added ‘pathlib.Path.with_stem()’ to create a new
     Path with the stem replaced.

   - bpo-40325(13): Deprecated support for set objects in
     random.sample().

   - bpo-40257(14): Improved help for the *note typing: 10a. module.
     Docstrings are now shown for all special forms and special generic
     aliases (like ‘Union’ and ‘List’).  Using ‘help()’ with generic
     alias like ‘List[int]’ will show the help for the correspondent
     concrete type (‘list’ in this case).

   - bpo-40257(15): *note inspect.getdoc(): bef. no longer returns
     docstring inherited from the type of the object or from parent
     class if it is a class if it is not defined in the object itself.
     In *note pydoc: ba. the documentation string is now shown not only
     for class, function, method etc, but for any object that has its
     own ‘__doc__’ attribute.

   - bpo-40287(16): Fixed ‘SpooledTemporaryFile.seek()’ to return the
     position.

   - bpo-40290(17): Added zscore() to statistics.NormalDist().

   - bpo-40282(18): Allow ‘random.getrandbits(0)’ to succeed and to
     return 0.

   - bpo-40286(19): Add *note random.randbytes(): 180e. function and
     *note random.Random.randbytes(): b25. method to generate random
     bytes.

   - bpo-40277(20): *note collections.namedtuple(): 4e1. now provides a
     human-readable repr for its field accessors.

   - bpo-40270(21): The included copy of sqlite3 on Windows is now
     compiled with the json extension.  This allows the use of functions
     such as ‘json_object’.

   - bpo-29255(22): Wait in ‘KqueueSelector.select’ when no fds are
     registered

   - bpo-40260(23): Ensure *note modulefinder: 95. uses *note
     io.open_code(): 1a80. and respects coding comments.

   - bpo-40234(24): Allow again to spawn daemon threads in
     subinterpreters (revert change which denied them).

   - bpo-39207(25): Workers in *note ProcessPoolExecutor: 1d6. are now
     spawned on demand, only when there are no available idle workers to
     reuse.  This optimizes startup overhead and reduces the amount of
     lost CPU time to idle workers.  Patch by Kyle Stanley.

   - bpo-40091(26): Fix a hang at fork in the logging module: the new
     private _at_fork_reinit() method is now used to reinitialize locks
     at fork in the child process.

   - bpo-40149(27): Implement traverse and clear slots in _abc._abc_data
     type.

   - bpo-40208(28): Remove deprecated ‘symtable.SymbolTable.has_exec()’.

   - bpo-40196(29): Fix a bug in the *note symtable: de. module that was
     causing incorrectly report global variables as local.  Patch by
     Pablo Galindo.

   - bpo-40190(30): Add support for ‘_SC_AIX_REALMEM’ to
     ‘posix.sysconf()’.

   - bpo-40182(31): Removed the ‘_field_types’ attribute of the *note
     typing.NamedTuple: 331. class.

   - bpo-36517(32): Multiple inheritance with *note typing.NamedTuple:
     331. now raises an error instead of silently ignoring other types.

   - bpo-40126(33): Fixed reverting multiple patches in unittest.mock.
     Patcher’s ‘__exit__()’ is now never called if its ‘__enter__()’ is
     failed.  Returning true from ‘__exit__()’ silences now the
     exception.

   - bpo-40094(34): CGIHTTPRequestHandler of http.server now logs the
     CGI script exit code, rather than the CGI script exit status of
     os.waitpid().  For example, if the script is killed by signal 11,
     it now logs: «CGI script exit code -11.»

   - bpo-40108(35): Improve the error message when triying to import a
     module using *note runpy: c3. and incorrectly using the «.py»
     extension at the end of the module name.  Patch by Pablo Galindo.

   - bpo-40094(36): Add *note os.waitstatus_to_exitcode(): b19.
     function: convert a wait status to an exit code.

   - bpo-40089(37): Fix threading._after_fork(): if fork was not called
     by a thread spawned by threading.Thread, threading._after_fork()
     now creates a _MainThread instance for _main_thread, instead of a
     _DummyThread instance.

   - bpo-40089(38): Add a private ‘_at_fork_reinit()’ method to
     ‘_thread.Lock’, ‘_thread.RLock’, *note threading.RLock: 32e. and
     *note threading.Condition: 135d. classes: reinitialize the lock at
     fork in the child process, reset the lock to the unlocked state.
     Rename also the private ‘_reset_internal_locks()’ method of *note
     threading.Event: 1360. to ‘_at_fork_reinit()’.

   - bpo-25780(39): Expose *note CAN_RAW_JOIN_FILTERS: b2d. in the *note
     socket: d1. module.

   - bpo-39503(40): *note AbstractBasicAuthHandler: 1c57. of *note
     urllib.request: 111. now parses all WWW-Authenticate HTTP headers
     and accepts multiple challenges per header: use the realm of the
     first Basic challenge.

   - bpo-39812(41): Removed daemon threads from *note
     concurrent.futures: 24. by adding an internal
     ‘threading._register_atexit()’, which calls registered functions
     prior to joining all non-daemon threads.  This allows for
     compatibility with subinterpreters, which don’t support daemon
     threads.

   - bpo-40050(42): Fix ‘importlib._bootstrap_external’: avoid creating
     a new ‘winreg’ builtin module if it’s already available in *note
     sys.modules: 17ce, and remove redundant imports.

   - bpo-40014(43): Fix ‘os.getgrouplist()’: if ‘getgrouplist()’
     function fails because the group list is too small, retry with a
     larger group list.  On failure, the glibc implementation of
     ‘getgrouplist()’ sets ‘ngroups’ to the total number of groups.  For
     other implementations, double the group list size.

   - bpo-40017(44): Add *note time.CLOCK_TAI: 1d3f. constant if the
     operating system support it.

   - bpo-40016(45): In re docstring, clarify the relationship between
     inline and argument compile flags.

   - bpo-39953(46): Update internal table of OpenSSL error codes in the
     ‘ssl’ module.

   - bpo-36144(47): Added PEP 584(48) operators to *note
     weakref.WeakValueDictionary: 1912.

   - bpo-36144(49): Added PEP 584(50) operators to *note
     weakref.WeakKeyDictionary: 1911.

   - bpo-38891(51): Fix linear runtime behaviour of the ‘__getitem__’
     and ‘__setitem__’ methods in *note
     multiprocessing.shared_memory.ShareableList: 1d40.  This avoids
     quadratic performance when iterating a ‘ShareableList’.  Patch by
     Thomas Krennwallner.

   - bpo-39682(52): Remove undocumented support for 'closing' a
     ‘pathlib.Path’ object via its context manager.  The context manager
     magic methods remain, but they are now a no-op, making ‘Path’
     objects immutable.

   - bpo-36144(53): Added PEP 584(54) operators (‘|’ and ‘|=’) to *note
     collections.ChainMap: e18.

   - bpo-39011(55): Normalization of line endings in ElementTree
     attributes was removed, as line endings which were replaced by
     entity numbers should be preserved in original form.

   - bpo-38410(56): Properly handle *note sys.audit(): 1903. failures in
     *note sys.set_asyncgen_hooks(): 1985.

   - bpo-36541(57): lib2to3 now recognizes named assignment expressions
     (the walrus operator, ‘:=’)

   - bpo-35967(58): In platform, delay the invocation of “uname -p”
     until the processor attribute is requested.

   - bpo-35113(59): *note inspect.getsource(): 17ab. now returns correct
     source code for inner class with same name as module level class.
     Decorators are also returned as part of source of the class.  Patch
     by Karthikeyan Singaravelan.

   - bpo-33262(60): Deprecate passing None as an argument for *note
     shlex.split(): 75f.”s ‘s’ parameter.  Patch by Zackery Spytz.

   - bpo-31758(61): Prevent crashes when using an uninitialized
     ‘_elementtree.XMLParser’ object.  Patch by Oren Milman.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40398

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40396

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38061

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38061

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40360

   (6) https://peps.python.org/pep-0617/

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40138

   (8) https://bugs.python.org/issue?@action=redirect&bpo=39942

   (9) https://bugs.python.org/issue?@action=redirect&bpo=40275

   (10) https://bugs.python.org/issue?@action=redirect&bpo=40275

   (11) https://bugs.python.org/issue?@action=redirect&bpo=40330

   (12) https://bugs.python.org/issue?@action=redirect&bpo=40148

   (13) https://bugs.python.org/issue?@action=redirect&bpo=40325

   (14) https://bugs.python.org/issue?@action=redirect&bpo=40257

   (15) https://bugs.python.org/issue?@action=redirect&bpo=40257

   (16) https://bugs.python.org/issue?@action=redirect&bpo=40287

   (17) https://bugs.python.org/issue?@action=redirect&bpo=40290

   (18) https://bugs.python.org/issue?@action=redirect&bpo=40282

   (19) https://bugs.python.org/issue?@action=redirect&bpo=40286

   (20) https://bugs.python.org/issue?@action=redirect&bpo=40277

   (21) https://bugs.python.org/issue?@action=redirect&bpo=40270

   (22) https://bugs.python.org/issue?@action=redirect&bpo=29255

   (23) https://bugs.python.org/issue?@action=redirect&bpo=40260

   (24) https://bugs.python.org/issue?@action=redirect&bpo=40234

   (25) https://bugs.python.org/issue?@action=redirect&bpo=39207

   (26) https://bugs.python.org/issue?@action=redirect&bpo=40091

   (27) https://bugs.python.org/issue?@action=redirect&bpo=40149

   (28) https://bugs.python.org/issue?@action=redirect&bpo=40208

   (29) https://bugs.python.org/issue?@action=redirect&bpo=40196

   (30) https://bugs.python.org/issue?@action=redirect&bpo=40190

   (31) https://bugs.python.org/issue?@action=redirect&bpo=40182

   (32) https://bugs.python.org/issue?@action=redirect&bpo=36517

   (33) https://bugs.python.org/issue?@action=redirect&bpo=40126

   (34) https://bugs.python.org/issue?@action=redirect&bpo=40094

   (35) https://bugs.python.org/issue?@action=redirect&bpo=40108

   (36) https://bugs.python.org/issue?@action=redirect&bpo=40094

   (37) https://bugs.python.org/issue?@action=redirect&bpo=40089

   (38) https://bugs.python.org/issue?@action=redirect&bpo=40089

   (39) https://bugs.python.org/issue?@action=redirect&bpo=25780

   (40) https://bugs.python.org/issue?@action=redirect&bpo=39503

   (41) https://bugs.python.org/issue?@action=redirect&bpo=39812

   (42) https://bugs.python.org/issue?@action=redirect&bpo=40050

   (43) https://bugs.python.org/issue?@action=redirect&bpo=40014

   (44) https://bugs.python.org/issue?@action=redirect&bpo=40017

   (45) https://bugs.python.org/issue?@action=redirect&bpo=40016

   (46) https://bugs.python.org/issue?@action=redirect&bpo=39953

   (47) https://bugs.python.org/issue?@action=redirect&bpo=36144

   (48) https://peps.python.org/pep-0584/

   (49) https://bugs.python.org/issue?@action=redirect&bpo=36144

   (50) https://peps.python.org/pep-0584/

   (51) https://bugs.python.org/issue?@action=redirect&bpo=38891

   (52) https://bugs.python.org/issue?@action=redirect&bpo=39682

   (53) https://bugs.python.org/issue?@action=redirect&bpo=36144

   (54) https://peps.python.org/pep-0584/

   (55) https://bugs.python.org/issue?@action=redirect&bpo=39011

   (56) https://bugs.python.org/issue?@action=redirect&bpo=38410

   (57) https://bugs.python.org/issue?@action=redirect&bpo=36541

   (58) https://bugs.python.org/issue?@action=redirect&bpo=35967

   (59) https://bugs.python.org/issue?@action=redirect&bpo=35113

   (60) https://bugs.python.org/issue?@action=redirect&bpo=33262

   (61) https://bugs.python.org/issue?@action=redirect&bpo=31758


File: python.info,  Node: Documentation<45>,  Next: Tests<45>,  Prev: Library<151>,  Up: Python 3 9 0 alpha 6

1.24.51.4 Documentation
.......................

   - bpo-27635(1): The pickle documentation incorrectly claimed that
     ‘__new__’ isn’t called by default when unpickling.

   - bpo-39879(2): Updated *note Data model: 1d42. docs to include *note
     dict(): 183. insertion order preservation.  Patch by Furkan Onder
     and Samy Lahfa.

   - bpo-38387(3): Document *note PyDoc_STRVAR: 1d43. macro in the C-API
     reference.

   - bpo-13743(4): Some methods within xml.dom.minidom.Element class are
     now better documented.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27635

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39879

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38387

   (4) https://bugs.python.org/issue?@action=redirect&bpo=13743


File: python.info,  Node: Tests<45>,  Next: Build<52>,  Prev: Documentation<45>,  Up: Python 3 9 0 alpha 6

1.24.51.5 Tests
...............

   - bpo-31904(1): Set expected default encoding in
     test_c_locale_coercion.py for VxWorks RTOS.

   - bpo-40162(2): Update Travis CI configuration to OpenSSL 1.1.1f.

   - bpo-40146(3): Update OpenSSL to 1.1.1f in Azure Pipelines.

   - bpo-40094(4): Add *note test.support.wait_process(): 1d45.
     function.

   - bpo-40003(5): ‘test.bisect_cmd’ now copies Python command line
     options like ‘-O’ or ‘-W’.  Moreover, emit a warning if
     ‘test.bisect_cmd’ is used with ‘-w’/‘--verbose2’ option.

   - bpo-39380(6): Add the encoding in *note ftplib.FTP: af8. and *note
     ftplib.FTP_TLS: af9. to the constructor as keyword-only and change
     the default from ‘latin-1’ to ‘utf-8’ to follow RFC 2640(7).

   - bpo-39793(8): Use the same domain when testing ‘make_msgid’.  Patch
     by Batuhan Taskaya.

   - bpo-1812(9): Fix newline handling in doctest.testfile when loading
     from a package whose loader has a get_data method.  Patch by Peter
     Donis.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40162

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40146

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40094

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40003

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39380

   (7) https://datatracker.ietf.org/doc/html/rfc2640.html

   (8) https://bugs.python.org/issue?@action=redirect&bpo=39793

   (9) https://bugs.python.org/issue?@action=redirect&bpo=1812


File: python.info,  Node: Build<52>,  Next: Windows<45>,  Prev: Tests<45>,  Up: Python 3 9 0 alpha 6

1.24.51.6 Build
...............

   - bpo-38360(1): Support single-argument form of macOS -isysroot flag.

   - bpo-40158(2): Fix CPython MSBuild Properties in NuGet Package
     (build/native/python.props)

   - bpo-38527(3): Fix configure check on Solaris for «float word
     ordering»: sometimes, the correct «grep» command was not being
     used.  Patch by Arnon Yaari.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38360

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40158

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38527


File: python.info,  Node: Windows<45>,  Next: macOS<35>,  Prev: Build<52>,  Up: Python 3 9 0 alpha 6

1.24.51.7 Windows
.................

   - bpo-40164(1): Updates Windows to OpenSSL 1.1.1f

   - bpo-8901(2): Ignore the Windows registry when the ‘-E’ option is
     used.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40164

   (2) https://bugs.python.org/issue?@action=redirect&bpo=8901


File: python.info,  Node: macOS<35>,  Next: IDLE<27>,  Prev: Windows<45>,  Up: Python 3 9 0 alpha 6

1.24.51.8 macOS
...............

   - bpo-38329(1): python.org macOS installers now update the Current
     version symlink of /Library/Frameworks/Python.framework/Versions
     for 3.9 installs.  Previously, Current was only updated for Python
     2.x installs.  This should make it easier to embed Python 3 into
     other macOS applications.

   - bpo-40164(2): Update macOS installer builds to use OpenSSL 1.1.1g.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38329

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40164


File: python.info,  Node: IDLE<27>,  Next: Tools/Demos<31>,  Prev: macOS<35>,  Up: Python 3 9 0 alpha 6

1.24.51.9 IDLE
..............

   - bpo-38439(1): Add a 256×256 pixel IDLE icon to support more modern
     environments.  Created by Andrew Clover.  Delete the unused macOS
     idle.icns icon file.

   - bpo-38689(2): IDLE will no longer freeze when inspect.signature
     fails when fetching a calltip.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38439

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38689


File: python.info,  Node: Tools/Demos<31>,  Next: C API<47>,  Prev: IDLE<27>,  Up: Python 3 9 0 alpha 6

1.24.51.10 Tools/Demos
......................

   - bpo-40385(1): Removed the checkpyc.py tool.  Please see compileall
     without force mode as a potential alternative.

   - bpo-40179(2): Fixed translation of ‘#elif’ in Argument Clinic.

   - bpo-40094(3): Fix ‘which.py’ script exit code: it now uses *note
     os.waitstatus_to_exitcode(): b19. to convert *note os.system():
     1664. exit status into an exit code.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40385

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40179

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40094


File: python.info,  Node: C API<47>,  Prev: Tools/Demos<31>,  Up: Python 3 9 0 alpha 6

1.24.51.11 C API
................

   - bpo-40241(1): Move the ‘PyGC_Head’ structure to the internal C API.

   - bpo-40170(2): Convert *note PyObject_IS_GC(): b7d. macro to a
     function to hide implementation details.

   - bpo-40241(3): Add the functions *note PyObject_GC_IsTracked(): b6f.
     and *note PyObject_GC_IsFinalized(): b70. to the public API to
     allow to query if Python objects are being currently tracked or
     have been already finalized by the garbage collector respectively.
     Patch by Pablo Galindo.

   - bpo-40170(4): The ‘PyObject_NEW()’ macro becomes an alias to the
     *note PyObject_New(): b7e. macro, and the ‘PyObject_NEW_VAR()’
     macro becomes an alias to the *note PyObject_NewVar(): b7f. macro,
     to hide implementation details.  They no longer access directly the
     *note PyTypeObject.tp_basicsize: b80. member.

   - bpo-40170(5): *note PyType_HasFeature(): 1d24. now always calls
     *note PyType_GetFlags(): 1d25. to hide implementation details.
     Previously, it accessed directly the *note PyTypeObject.tp_flags:
     1c59. member when the limited C API was not used.

   - bpo-40170(6): Convert the ‘PyObject_GET_WEAKREFS_LISTPTR()’ macro
     to a function to hide implementation details: the macro accessed
     directly to the *note PyTypeObject.tp_weaklistoffset: b81. member.

   - bpo-40170(7): Convert *note PyObject_CheckBuffer(): 639. macro to a
     function to hide implementation details: the macro accessed
     directly the *note PyTypeObject.tp_as_buffer: b82. member.

   - bpo-40170(8): Always declare *note PyIndex_Check(): b83. as an
     opaque function to hide implementation details: remove
     ‘PyIndex_Check()’ macro.  The macro accessed directly the *note
     PyTypeObject.tp_as_number: b84. member.

   - bpo-39947(9): Add *note PyThreadState_GetID(): b6c. function: get
     the unique identifier of a Python thread state.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40241

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (3) https://bugs.python.org/issue?@action=redirect&bpo=40241

   (4) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (5) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (7) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (8) https://bugs.python.org/issue?@action=redirect&bpo=40170

   (9) https://bugs.python.org/issue?@action=redirect&bpo=39947


File: python.info,  Node: Python 3 9 0 alpha 5,  Next: Python 3 9 0 alpha 4,  Prev: Python 3 9 0 alpha 6,  Up: Changelog

1.24.52 Python 3.9.0 alpha 5
----------------------------

'Release date: 2020-03-23'

* Menu:

* Security: Security<39>.
* Core and Builtins: Core and Builtins<149>.
* Library: Library<152>.
* Documentation: Documentation<46>.
* Tests: Tests<46>.
* Build: Build<53>.
* Windows: Windows<46>.
* macOS: macOS<36>.
* IDLE: IDLE<28>.
* Tools/Demos: Tools/Demos<32>.
* C API: C API<48>.


File: python.info,  Node: Security<39>,  Next: Core and Builtins<149>,  Up: Python 3 9 0 alpha 5

1.24.52.1 Security
..................

   - bpo-38576(1): Disallow control characters in hostnames in
     http.client, addressing CVE 2019-18348(2).  Such potentially
     malicious header injection URLs now cause a InvalidURL to be
     raised.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38576

   (2) https://www.cve.org/CVERecord?id=CVE-2019-18348


File: python.info,  Node: Core and Builtins<149>,  Next: Library<152>,  Prev: Security<39>,  Up: Python 3 9 0 alpha 5

1.24.52.2 Core and Builtins
...........................

   - bpo-40010(1): Optimize pending calls in multithreaded applications.
     If a thread different than the main thread schedules a pending call
     (*note Py_AddPendingCall(): b7a.), the bytecode evaluation loop is
     no longer interrupted at each bytecode instruction to check for
     pending calls which cannot be executed.  Only the main thread can
     execute pending calls.

     Previously, the bytecode evaluation loop was interrupted at each
     instruction until the main thread executes pending calls.

   - bpo-1635741(2): Port _weakref extension module to multiphase
     initialization ( PEP 489(3)).

   - bpo-1635741(4): Port _collections module to multiphase
     initialization ( PEP 489(5)).

   - bpo-40010(6): Optimize signal handling in multithreaded
     applications.  If a thread different than the main thread gets a
     signal, the bytecode evaluation loop is no longer interrupted at
     each bytecode instruction to check for pending signals which cannot
     be handled.  Only the main thread of the main interpreter can
     handle signals.

     Previously, the bytecode evaluation loop was interrupted at each
     instruction until the main thread handles signals.

   - bpo-39984(7): If *note Py_AddPendingCall(): b7a. is called in a
     subinterpreter, the function is now scheduled to be called from the
     subinterpreter, rather than being called from the main interpreter.
     Each subinterpreter now has its own list of scheduled calls.

   - bpo-1635741(8): Port _heapq module to multiphase initialization.

   - bpo-1635741(9): Port itertools module to multiphase initialization
     ( PEP 489(10)).

   - bpo-37207(11): Speed up calls to ‘frozenset()’ by using the PEP
     590(12) ‘vectorcall’ calling convention.  Patch by Donghee Na.

   - bpo-39984(13): subinterpreters: Move
     ‘_PyRuntimeState.ceval.tracing_possible’ to
     ‘PyInterpreterState.ceval.tracing_possible’: each interpreter now
     has its own variable.

   - bpo-37207(14): Speed up calls to ‘set()’ by using the PEP 590(15)
     ‘vectorcall’ calling convention.  Patch by Donghee Na.

   - bpo-1635741(16): Port _statistics module to multiphase
     initialization ( PEP 489(17)).

   - bpo-39968(18): Use inline function to replace extension modules”
     get_module_state macros.

   - bpo-39965(19): Correctly raise ‘SyntaxError’ if 'await' is used
     inside non-async functions and ‘PyCF_ALLOW_TOP_LEVEL_AWAIT’ is set
     (like in the asyncio REPL). Patch by Pablo Galindo.

   - bpo-39562(20): Allow executing asynchronous comprehensions on the
     top level when the ‘PyCF_ALLOW_TOP_LEVEL_AWAIT’ flag is given.
     Patch by Batuhan Taskaya.

   - bpo-37207(21): Speed up calls to ‘tuple()’ by using the PEP 590(22)
     ‘vectorcall’ calling convention.  Patch by Donghee Na.

   - bpo-38373(23): Changed list overallocation strategy.  It no longer
     overallocates if the new size is closer to overallocated size than
     to the old size and adds padding.

   - bpo-39926(24): Update Unicode database to Unicode version 13.0.0.

   - bpo-19466(25): Clear the frames of daemon threads earlier during
     the Python shutdown to call objects destructors.  So «unclosed
     file» resource warnings are now emitted for daemon threads in a
     more reliable way.

   - bpo-38894(26): Fix a bug that was causing incomplete results when
     calling ‘pathlib.Path.glob’ in the presence of symlinks that point
     to files where the user does not have read access.  Patch by Pablo
     Galindo and Matt Wozniski.

   - bpo-39877(27): Fix *note PyEval_RestoreThread(): 648. random crash
     at exit with daemon threads.  It now accesses the ‘_PyRuntime’
     variable directly instead of using ‘tstate->interp->runtime’, since
     ‘tstate’ can be a dangling pointer after *note Py_Finalize(): 45f.
     has been called.  Moreover, the daemon thread now exits before
     trying to take the GIL.

   - bpo-39871(28): Fix a possible *note SystemError: 796. in
     ‘math.{atan2,copysign,remainder}()’ when the first argument cannot
     be converted to a *note float: 196.  Patch by Zackery Spytz.

   - bpo-39776(29): Fix race condition where threads created by
     PyGILState_Ensure() could get a duplicate id.

     This affects consumers of tstate->id like the contextvar caching
     machinery, which could return invalid cached objects under heavy
     thread load (observed in embedded scenarios).

   - bpo-39778(30): Fixed a crash due to incorrect handling of weak
     references in ‘collections.OrderedDict’ classes.  Patch by Pablo
     Galindo.

   - bpo-1635741(31): Port audioop extension module to multiphase
     initialization ( PEP 489(32)).

   - bpo-39702(33): Relax *note decorator: 93b. grammar restrictions to
     allow any valid expression ( PEP 614(34)).

   - bpo-38091(35): Tweak import deadlock detection code to not deadlock
     itself.

   - bpo-1635741(36): Port _locale extension module to multiphase
     initialization ( PEP 489(37)).

   - bpo-39087(38): Optimize *note PyUnicode_AsUTF8(): 424. and *note
     PyUnicode_AsUTF8AndSize(): a9b. slightly when they need to create
     internal UTF-8 cache.

   - bpo-39520(39): Fix unparsing of ext slices with no items
     (‘foo[:,]’).  Patch by Batuhan Taskaya.

   - bpo-39220(40): Do not optimize annotations if “from __future__
     import annotations” is used.  Patch by Pablo Galindo.

   - bpo-35712(41): Using *note NotImplemented: 1a2. in a boolean
     context has been deprecated.  Patch contributed by Josh Rosenberg.

   - bpo-22490(42): Don’t leak environment variable
     ‘__PYVENV_LAUNCHER__’ into the interpreter session on macOS.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40010

   (2) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (3) https://peps.python.org/pep-0489/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (5) https://peps.python.org/pep-0489/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=40010

   (7) https://bugs.python.org/issue?@action=redirect&bpo=39984

   (8) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (9) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (10) https://peps.python.org/pep-0489/

   (11) https://bugs.python.org/issue?@action=redirect&bpo=37207

   (12) https://peps.python.org/pep-0590/

   (13) https://bugs.python.org/issue?@action=redirect&bpo=39984

   (14) https://bugs.python.org/issue?@action=redirect&bpo=37207

   (15) https://peps.python.org/pep-0590/

   (16) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (17) https://peps.python.org/pep-0489/

   (18) https://bugs.python.org/issue?@action=redirect&bpo=39968

   (19) https://bugs.python.org/issue?@action=redirect&bpo=39965

   (20) https://bugs.python.org/issue?@action=redirect&bpo=39562

   (21) https://bugs.python.org/issue?@action=redirect&bpo=37207

   (22) https://peps.python.org/pep-0590/

   (23) https://bugs.python.org/issue?@action=redirect&bpo=38373

   (24) https://bugs.python.org/issue?@action=redirect&bpo=39926

   (25) https://bugs.python.org/issue?@action=redirect&bpo=19466

   (26) https://bugs.python.org/issue?@action=redirect&bpo=38894

   (27) https://bugs.python.org/issue?@action=redirect&bpo=39877

   (28) https://bugs.python.org/issue?@action=redirect&bpo=39871

   (29) https://bugs.python.org/issue?@action=redirect&bpo=39776

   (30) https://bugs.python.org/issue?@action=redirect&bpo=39778

   (31) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (32) https://peps.python.org/pep-0489/

   (33) https://bugs.python.org/issue?@action=redirect&bpo=39702

   (34) https://peps.python.org/pep-0614/

   (35) https://bugs.python.org/issue?@action=redirect&bpo=38091

   (36) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (37) https://peps.python.org/pep-0489/

   (38) https://bugs.python.org/issue?@action=redirect&bpo=39087

   (39) https://bugs.python.org/issue?@action=redirect&bpo=39520

   (40) https://bugs.python.org/issue?@action=redirect&bpo=39220

   (41) https://bugs.python.org/issue?@action=redirect&bpo=35712

   (42) https://bugs.python.org/issue?@action=redirect&bpo=22490


File: python.info,  Node: Library<152>,  Next: Documentation<46>,  Prev: Core and Builtins<149>,  Up: Python 3 9 0 alpha 5

1.24.52.3 Library
.................

   - bpo-39830(1): Add *note zipfile.Path: 8d9. to ‘__all__’ in the
     *note zipfile: 137. module.

   - bpo-40000(2): Improved error messages for validation of
     ‘ast.Constant’ nodes.  Patch by Batuhan Taskaya.

   - bpo-39999(3): ‘__module__’ of the AST node classes is now set to
     «ast» instead of «_ast».  Added docstrings for dummy AST node
     classes and deprecated attributes.

   - bpo-39991(4): *note uuid.getnode(): da2. now skips IPv6 addresses
     with the same string length than a MAC address (17 characters):
     only use MAC addresses.

   - bpo-39988(5): Deprecated ‘ast.AugLoad’ and ‘ast.AugStore’ node
     classes because they are no longer used.

   - bpo-39656(6): Ensure ‘bin/python3.#’ is always present in virtual
     environments on POSIX platforms - by Anthony Sottile.

   - bpo-39969(7): Deprecated ‘ast.Param’ node class because it’s no
     longer used.  Patch by Batuhan Taskaya.

   - bpo-39360(8): Ensure all workers exit when finalizing a
     ‘multiprocessing.Pool’ implicitly via the module finalization
     handlers of multiprocessing.  This fixes a deadlock situation that
     can be experienced when the Pool is not properly finalized via the
     context manager or a call to ‘multiprocessing.Pool.terminate’.
     Patch by Batuhan Taskaya and Pablo Galindo.

   - bpo-35370(9): sys.settrace(), sys.setprofile() and
     _lsprof.Profiler.enable() now properly report *note PySys_Audit():
     613. error if «sys.setprofile» or «sys.settrace» audit event is
     denied.

   - bpo-39936(10): AIX: Fix _aix_support module when the subprocess is
     not available, when building Python from scratch.  It now uses new
     private _bootsubprocess module, rather than having two
     implementations depending if subprocess is available or not.  So
     _aix_support.aix_platform() result is now the same if subprocess is
     available or not.

   - bpo-36144(11): *note collections.OrderedDict: 7f4. now implements
     ‘|’ and ‘|=’ ( PEP 584(12)).

   - bpo-39652(13): The column name found in
     ‘sqlite3.Cursor.description’ is now truncated on the first “[” only
     if the PARSE_COLNAMES option is set.

   - bpo-39915(14): Ensure *note
     unittest.mock.AsyncMock.await_args_list: 1d50. has call objects in
     the order of awaited arguments instead of using *note
     unittest.mock.Mock.call_args: 1d51. which has the last value of the
     call.  Patch by Karthikeyan Singaravelan.

   - bpo-36144(15): Updated *note os.environ: 259. and *note
     os.environb: 25a. to support PEP 584(16)’s merge (‘|’) and update
     (‘|=’) operators.

   - bpo-38662(17): The ‘ensurepip’ module now invokes ‘pip’ via the
     ‘runpy’ module.  Hence it is no longer tightly coupled with the
     internal API of the bundled ‘pip’ version, allowing easier updates
     to a newer ‘pip’ version both internally and for distributors.

   - bpo-38075(18): Fix the *note random.Random.seed(): 1d52. method
     when a *note bool: 3c3. is passed as the seed.

   - bpo-39916(19): More reliable use of ‘os.scandir()’ in
     ‘Path.glob()’.  It no longer emits a ResourceWarning when
     interrupted.

   - bpo-39850(20): *note multiprocessing: 98. now supports abstract
     socket addresses (if abstract sockets are supported in the running
     platform).  When creating arbitrary addresses (like when
     default-constructing *note multiprocessing.connection.Listener:
     1a0b. objects) abstract sockets are preferred to avoid the case
     when the temporary-file-generated address is too large for an
     AF_UNIX socket address.  Patch by Pablo Galindo.

   - bpo-36287(21): *note ast.dump(): ae3. no longer outputs optional
     fields and attributes with default values.  The default values for
     optional fields and attributes of AST nodes are now set as class
     attributes (e.g.  ‘Constant.kind’ is set to ‘None’).

   - bpo-39889(22): Fixed *note ast.unparse(): ae4. for extended slices
     containing a single element (e.g.  ‘a[i:j,]’).  Remove redundant
     tuples when index with a tuple (e.g.  ‘a[i, j]’).

   - bpo-39828(23): Fix *note json.tool: 87. to catch *note
     BrokenPipeError: 125e.  Patch by Donghee Na.

   - bpo-13487(24): Avoid a possible '«RuntimeError: dictionary changed
     size during iteration»' from *note inspect.getmodule(): 1b55. when
     it tried to loop through *note sys.modules: 17ce.

   - bpo-39674(25): Revert «bpo-37330(26): open() no longer accept “U”
     in file mode».  The «U» mode of open() is kept in Python 3.9 to
     ease transition from Python 2.7, but will be removed in Python
     3.10.

   - bpo-28577(27): The hosts method on 32-bit prefix length
     IPv4Networks and 128-bit prefix IPv6Networks now returns a list
     containing the single Address instead of an empty list.

   - bpo-39826(28): Add getConnection method to logging HTTPHandler to
     enable custom connections.

   - bpo-39763(29): Reimplement ‘distutils.spawn.spawn’ function with
     the *note subprocess: dc. module.

   - bpo-39794(30): Add –without-decimal-contextvar build option.  This
     enables a thread-local rather than a coroutine local context.

   - bpo-36144(31): *note collections.defaultdict: 13c4. now implements
     ‘|’ ( PEP 584(32)).

   - bpo-39517(33): Fix runpy.run_path() when using pathlike objects

   - bpo-39775(34): Change ‘inspect.Signature.parameters’ back to
     ‘collections.OrderedDict’.  This was changed to ‘dict’ in Python
     3.9.0a4.

   - bpo-39678(35): Refactor queue_manager in *note
     concurrent.futures.ProcessPoolExecutor: 1d6. to make it easier to
     maintain.

   - bpo-39764(36): Fix AttributeError when calling get_stack on a
     PyAsyncGenObject Task

   - bpo-39769(37): The *note compileall.compile_dir(): d1d. function’s
     'ddir' parameter and the compileall command line flag ‘-d’ no
     longer write the wrong pathname to the generated pyc file for
     submodules beneath the root of the directory tree being compiled.
     This fixes a regression introduced with Python 3.5.

   - bpo-36144(38): *note types.MappingProxyType: 699. objects now
     support the merge (‘|’) operator from PEP 584(39).

   - bpo-38691(40): The *note importlib: 7b. module now ignores the
     *note PYTHONCASEOK: b57. environment variable when the *note -E:
     b58. or *note -I: b59. command line options are being used.

   - bpo-39719(41): Remove ‘tempfile.SpooledTemporaryFile.softspace()’
     as files no longer have the ‘softspace’ attribute in Python 3.
     Patch by Shantanu.

   - bpo-39667(42): Improve pathlib.Path compatibility on zipfile.Path
     and correct performance degradation as found in zipp 3.0.

   - bpo-39638(43): Keep ASDL signatures in the docstrings for ‘AST’
     nodes.  Patch by Batuhan Taskaya

   - bpo-39639(44): Deprecated ‘ast.Suite’ node class because it’s no
     longer used.  Patch by Batuhan Taskaya.

   - bpo-39609(45): Add thread_name_prefix to default asyncio executor

   - bpo-39548(46): Fix handling of header in *note
     urllib.request.AbstractDigestAuthHandler: 1d53. when the optional
     ‘qop’ parameter is not present.

   - bpo-39509(47): HTTP status codes ‘103 EARLY_HINTS’ and ‘425
     TOO_EARLY’ are added to *note http.HTTPStatus: afe.  Patch by
     Donghee Na.

   - bpo-39507(48): Adding HTTP status 418 «I’m a Teapot» to HTTPStatus
     in http library.  Patch by Ross Rhodes.

   - bpo-39495(49): Remove default value from 'attrs' parameter of *note
     xml.etree.ElementTree.TreeBuilder.start(): 1d54. for consistency
     between Python and C implementations.

   - bpo-38971(50): Open issue in the BPO indicated a desire to make the
     implementation of codecs.open() at parity with io.open(), which
     implements a try/except to assure file stream gets closed before an
     exception is raised.

   - bpo-38641(51): Added starred expressions support to ‘return’ and
     ‘yield’ statements for ‘lib2to3’.  Patch by Vlad Emelianov.

   - bpo-37534(52): When using minidom module to generate XML documents
     the ability to add Standalone Document Declaration is added.  All
     the changes are made to generate a document in compliance with
     Extensible Markup Language (XML) 1.0 (Fifth Edition) W3C
     Recommendation (available here:
     ‘https://www.w3.org/TR/xml/#sec-prolog-dtd’).

   - bpo-34788(53): Add support for scoped IPv6 addresses to *note
     ipaddress: 84.  Patch by Oleksandr Pavliuk.

   - bpo-34822(54): Simplified AST for subscription.  Simple indices are
     now represented by their value, extended slices are represented as
     tuples.  *note ast: 9. classes ‘Index’ and ‘ExtSlice’ are
     considered deprecated and will be removed in future Python
     versions.  In the meantime, ‘Index(value)’ now returns a ‘value’
     itself, ‘ExtSlice(slices)’ returns ‘Tuple(slices, Load())’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39830

   (2) https://bugs.python.org/issue?@action=redirect&bpo=40000

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39999

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39991

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39988

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39656

   (7) https://bugs.python.org/issue?@action=redirect&bpo=39969

   (8) https://bugs.python.org/issue?@action=redirect&bpo=39360

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35370

   (10) https://bugs.python.org/issue?@action=redirect&bpo=39936

   (11) https://bugs.python.org/issue?@action=redirect&bpo=36144

   (12) https://peps.python.org/pep-0584/

   (13) https://bugs.python.org/issue?@action=redirect&bpo=39652

   (14) https://bugs.python.org/issue?@action=redirect&bpo=39915

   (15) https://bugs.python.org/issue?@action=redirect&bpo=36144

   (16) https://peps.python.org/pep-0584/

   (17) https://bugs.python.org/issue?@action=redirect&bpo=38662

   (18) https://bugs.python.org/issue?@action=redirect&bpo=38075

   (19) https://bugs.python.org/issue?@action=redirect&bpo=39916

   (20) https://bugs.python.org/issue?@action=redirect&bpo=39850

   (21) https://bugs.python.org/issue?@action=redirect&bpo=36287

   (22) https://bugs.python.org/issue?@action=redirect&bpo=39889

   (23) https://bugs.python.org/issue?@action=redirect&bpo=39828

   (24) https://bugs.python.org/issue?@action=redirect&bpo=13487

   (25) https://bugs.python.org/issue?@action=redirect&bpo=39674

   (26) https://bugs.python.org/issue?@action=redirect&bpo=37330

   (27) https://bugs.python.org/issue?@action=redirect&bpo=28577

   (28) https://bugs.python.org/issue?@action=redirect&bpo=39826

   (29) https://bugs.python.org/issue?@action=redirect&bpo=39763

   (30) https://bugs.python.org/issue?@action=redirect&bpo=39794

   (31) https://bugs.python.org/issue?@action=redirect&bpo=36144

   (32) https://peps.python.org/pep-0584/

   (33) https://bugs.python.org/issue?@action=redirect&bpo=39517

   (34) https://bugs.python.org/issue?@action=redirect&bpo=39775

   (35) https://bugs.python.org/issue?@action=redirect&bpo=39678

   (36) https://bugs.python.org/issue?@action=redirect&bpo=39764

   (37) https://bugs.python.org/issue?@action=redirect&bpo=39769

   (38) https://bugs.python.org/issue?@action=redirect&bpo=36144

   (39) https://peps.python.org/pep-0584/

   (40) https://bugs.python.org/issue?@action=redirect&bpo=38691

   (41) https://bugs.python.org/issue?@action=redirect&bpo=39719

   (42) https://bugs.python.org/issue?@action=redirect&bpo=39667

   (43) https://bugs.python.org/issue?@action=redirect&bpo=39638

   (44) https://bugs.python.org/issue?@action=redirect&bpo=39639

   (45) https://bugs.python.org/issue?@action=redirect&bpo=39609

   (46) https://bugs.python.org/issue?@action=redirect&bpo=39548

   (47) https://bugs.python.org/issue?@action=redirect&bpo=39509

   (48) https://bugs.python.org/issue?@action=redirect&bpo=39507

   (49) https://bugs.python.org/issue?@action=redirect&bpo=39495

   (50) https://bugs.python.org/issue?@action=redirect&bpo=38971

   (51) https://bugs.python.org/issue?@action=redirect&bpo=38641

   (52) https://bugs.python.org/issue?@action=redirect&bpo=37534

   (53) https://bugs.python.org/issue?@action=redirect&bpo=34788

   (54) https://bugs.python.org/issue?@action=redirect&bpo=34822


File: python.info,  Node: Documentation<46>,  Next: Tests<46>,  Prev: Library<152>,  Up: Python 3 9 0 alpha 5

1.24.52.4 Documentation
.......................

   - bpo-39868(1): Updated the Language Reference for PEP 572(2).

   - bpo-13790(3): Change “string” to “specification” in format doc.

   - bpo-17422(4): The language reference no longer restricts default
     class namespaces to dicts only.

   - bpo-39530(5): Fix misleading documentation about mixed-type numeric
     comparisons.

   - bpo-39718(6): Update *note token: 100. documentation to reflect
     additions in Python 3.8

   - bpo-39677(7): Changed operand name of 'MAKE_FUNCTION' from 'argc'
     to 'flags' for module *note dis: 3c.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39868

   (2) https://peps.python.org/pep-0572/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=13790

   (4) https://bugs.python.org/issue?@action=redirect&bpo=17422

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39530

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39718

   (7) https://bugs.python.org/issue?@action=redirect&bpo=39677


File: python.info,  Node: Tests<46>,  Next: Build<53>,  Prev: Documentation<46>,  Up: Python 3 9 0 alpha 5

1.24.52.5 Tests
...............

   - bpo-40019(1): test_gdb now skips tests if it detects that gdb
     failed to read debug information because the Python binary is
     optimized.

   - bpo-27807(2): ‘test_site.test_startup_imports()’ is now skipped if
     a path of *note sys.path: 3e4. contains a ‘.pth’ file.

   - bpo-26067(3): Do not fail test_shutil test_chown test when uid or
     gid of user cannot be resolved to a name.

   - bpo-39855(4): test_subprocess.test_user() now skips the test on an
     user name if the user name doesn’t exist.  For example, skip the
     test if the user «nobody» doesn’t exist on Linux.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40019

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27807

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26067

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39855


File: python.info,  Node: Build<53>,  Next: Windows<46>,  Prev: Tests<46>,  Up: Python 3 9 0 alpha 5

1.24.52.6 Build
...............

   - bpo-39761(1): Fix build with DTrace but without additional DFLAGS.

   - bpo-39763(2): setup.py now uses a basic implementation of the *note
     subprocess: dc. module if the *note subprocess: dc. module is not
     available: before required C extension modules are built.

   - bpo-1294959(3): Add ‘--with-platlibdir’ option to the configure
     script: name of the platform-specific library directory, stored in
     the new *note sys.platlibdir: b34. attribute.  It is used to build
     the path of platform-specific extension modules and the path of the
     standard library.  It is equal to ‘"lib"’ on most platforms.  On
     Fedora and SuSE, it is equal to ‘"lib64"’ on 64-bit platforms.
     Patch by Jan Matějek, Matěj Cepl, Charalampos Stratakis and Victor
     Stinner.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39761

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39763

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1294959


File: python.info,  Node: Windows<46>,  Next: macOS<36>,  Prev: Build<53>,  Up: Python 3 9 0 alpha 5

1.24.52.7 Windows
.................

   - bpo-39930(1): Ensures the required ‘vcruntime140.dll’ is included
     in install packages.

   - bpo-39847(2): Avoid hang when computer is hibernated whilst waiting
     for a mutex (for lock-related objects from *note threading: f3.)
     around 49-day uptime.

   - bpo-38597(3): ‘distutils’ will no longer statically link
     ‘vcruntime140.dll’ when a redistributable version is unavailable.
     All future releases of CPython will include a copy of this DLL to
     ensure distributed extensions can continue to load.

   - bpo-38380(4): Update Windows builds to use SQLite 3.31.1

   - bpo-39789(5): Update Windows release build machines to Visual
     Studio 2019 (MSVC 14.2).

   - bpo-34803(6): Package for nuget.org now includes repository
     reference and bundled icon image.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39930

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39847

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38597

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38380

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39789

   (6) https://bugs.python.org/issue?@action=redirect&bpo=34803


File: python.info,  Node: macOS<36>,  Next: IDLE<28>,  Prev: Windows<46>,  Up: Python 3 9 0 alpha 5

1.24.52.8 macOS
...............

   - bpo-38380(1): Update macOS builds to use SQLite 3.31.1

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38380


File: python.info,  Node: IDLE<28>,  Next: Tools/Demos<32>,  Prev: macOS<36>,  Up: Python 3 9 0 alpha 5

1.24.52.9 IDLE
..............

   - bpo-27115(1): For “Go to Line”, use a Query box subclass with IDLE
     standard behavior and improved error checking.

   - bpo-39885(2): Since clicking to get an IDLE context menu moves the
     cursor, any text selection should be and now is cleared.

   - bpo-39852(3): Edit «Go to line» now clears any selection,
     preventing accidental deletion.  It also updates Ln and Col on the
     status bar.

   - bpo-39781(4): Selecting code context lines no longer causes a jump.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27115

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39885

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39852

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39781


File: python.info,  Node: Tools/Demos<32>,  Next: C API<48>,  Prev: IDLE<28>,  Up: Python 3 9 0 alpha 5

1.24.52.10 Tools/Demos
......................

   - bpo-36184(1): Port python-gdb.py to FreeBSD. python-gdb.py now
     checks for «take_gil» function name to check if a frame tries to
     acquire the GIL, instead of checking for «pthread_cond_timedwait»
     which is specific to Linux and can be a different condition than
     the GIL.

   - bpo-38080(2): Added support to fix ‘getproxies’ in the
     ‘lib2to3.fixes.fix_urllib’ module.  Patch by José Roberto Meza
     Cabrera.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36184

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38080


File: python.info,  Node: C API<48>,  Prev: Tools/Demos<32>,  Up: Python 3 9 0 alpha 5

1.24.52.11 C API
................

   - bpo-40024(1): Add *note PyModule_AddType(): b6e. helper function:
     add a type to a module.  Patch by Donghee Na.

   - bpo-39946(2): Remove ‘_PyRuntime.getframe’ hook and remove
     ‘_PyThreadState_GetFrame’ macro which was an alias to
     ‘_PyRuntime.getframe’.  They were only exposed by the internal C
     API. Remove also ‘PyThreadFrameGetter’ type.

   - bpo-39947(3): Add *note PyThreadState_GetFrame(): 992. function:
     get the current frame of a Python thread state.

   - bpo-37207(4): Add _PyArg_NoKwnames helper function.  Patch by
     Donghee Na.

   - bpo-39947(5): Add *note PyThreadState_GetInterpreter(): b6b.: get
     the interpreter of a Python thread state.

   - bpo-39947(6): Add *note PyInterpreterState_Get(): 64c. function to
     the limited C API.

   - bpo-35370(7): If *note PySys_Audit(): 613. fails in *note
     PyEval_SetProfile(): 1704. or *note PyEval_SetTrace(): 663, log the
     error as an unraisable exception.

   - bpo-39947(8): Move the static inline function flavor of
     Py_EnterRecursiveCall() and Py_LeaveRecursiveCall() to the internal
     C API: they access PyThreadState attributes.  The limited C API
     provides regular functions which hide implementation details.

   - bpo-39947(9): Py_TRASHCAN_BEGIN_CONDITION and Py_TRASHCAN_END macro
     no longer access PyThreadState attributes, but call new private
     _PyTrash_begin() and _PyTrash_end() functions which hide
     implementation details.

   - bpo-39884(10): *note PyDescr_NewMethod(): 1d5d. and *note
     PyCFunction_NewEx(): 1d5e. now include the method name in the
     SystemError «bad call flags» error message to ease debug.

   - bpo-39877(11): Deprecated ‘PyEval_InitThreads()’ and
     ‘PyEval_ThreadsInitialized()’.  Calling ‘PyEval_InitThreads()’ now
     does nothing.

   - bpo-38249(12): *note Py_UNREACHABLE: db0. is now implemented with
     ‘__builtin_unreachable()’ and analogs in release mode.

   - bpo-38643(13): *note PyNumber_ToBase(): 1b5b. now raises a *note
     SystemError: 796. instead of crashing when called with invalid
     base.

   - bpo-39882(14): The *note Py_FatalError(): b7c. function is replaced
     with a macro which logs automatically the name of the current
     function, unless the ‘Py_LIMITED_API’ macro is defined.

   - bpo-39824(15): Extension modules: *note m_traverse: b73, *note
     m_clear: b74. and *note m_free: b75. functions of *note
     PyModuleDef: b76. are no longer called if the module state was
     requested but is not allocated yet.  This is the case immediately
     after the module is created and before the module is executed
     (*note Py_mod_exec: b77. function).  More precisely, these
     functions are not called if *note m_size: b78. is greater than 0
     and the module state (as returned by *note PyModule_GetState():
     b79.) is ‘NULL’.

     Extension modules without module state (‘m_size <= 0’) are not
     affected.

   - bpo-38913(16): Fixed segfault in ‘Py_BuildValue()’ called with a
     format containing «#» and undefined PY_SSIZE_T_CLEAN whwn an
     exception is set.

   - bpo-38500(17): Add a private API to get and set the frame
     evaluation function: add *note
     _PyInterpreterState_GetEvalFrameFunc(): 1d5f. and *note
     _PyInterpreterState_SetEvalFrameFunc(): 1d60. C functions.  The
     *note _PyFrameEvalFunction: 97b. function type now takes a 'tstate'
     parameter.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=40024

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39946

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39947

   (4) https://bugs.python.org/issue?@action=redirect&bpo=37207

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39947

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39947

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35370

   (8) https://bugs.python.org/issue?@action=redirect&bpo=39947

   (9) https://bugs.python.org/issue?@action=redirect&bpo=39947

   (10) https://bugs.python.org/issue?@action=redirect&bpo=39884

   (11) https://bugs.python.org/issue?@action=redirect&bpo=39877

   (12) https://bugs.python.org/issue?@action=redirect&bpo=38249

   (13) https://bugs.python.org/issue?@action=redirect&bpo=38643

   (14) https://bugs.python.org/issue?@action=redirect&bpo=39882

   (15) https://bugs.python.org/issue?@action=redirect&bpo=39824

   (16) https://bugs.python.org/issue?@action=redirect&bpo=38913

   (17) https://bugs.python.org/issue?@action=redirect&bpo=38500


File: python.info,  Node: Python 3 9 0 alpha 4,  Next: Python 3 9 0 alpha 3,  Prev: Python 3 9 0 alpha 5,  Up: Changelog

1.24.53 Python 3.9.0 alpha 4
----------------------------

'Release date: 2020-02-25'

* Menu:

* Security: Security<40>.
* Core and Builtins: Core and Builtins<150>.
* Library: Library<153>.
* Documentation: Documentation<47>.
* Tests: Tests<47>.
* Build: Build<54>.
* Windows: Windows<47>.
* IDLE: IDLE<29>.
* C API: C API<49>.


File: python.info,  Node: Security<40>,  Next: Core and Builtins<150>,  Up: Python 3 9 0 alpha 4

1.24.53.1 Security
..................

   - bpo-39184(1): Add audit events to functions in ‘fcntl’, ‘msvcrt’,
     ‘os’, ‘resource’, ‘shutil’, ‘signal’ and ‘syslog’.

   - bpo-39401(2): Avoid unsafe DLL load at startup on Windows 7 and
     earlier.

   - bpo-39184(3): Add audit events to command execution functions in os
     and pty modules.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39184

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39401

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39184


File: python.info,  Node: Core and Builtins<150>,  Next: Library<153>,  Prev: Security<40>,  Up: Python 3 9 0 alpha 4

1.24.53.2 Core and Builtins
...........................

   - bpo-39382(1): Fix a use-after-free in the single inheritance path
     of ‘issubclass()’, when the ‘__bases__’ of an object has a single
     reference, and so does its first item.  Patch by Yonatan
     Goldschmidt.

   - bpo-39573(2): Update clinic tool to use *note Py_IS_TYPE(): 1b88.
     Patch by Donghee Na.

   - bpo-39619(3): Enable use of *note os.chroot(): 1d64. on HP-UX
     systems.

   - bpo-39573(4): Add *note Py_IS_TYPE(): 1b88. static inline function
     to check whether the object 'o' type is 'type'.

   - bpo-39606(5): Fix regression caused by fix for bpo-39386(6), that
     prevented calling ‘aclose’ on an async generator that had already
     been closed or exhausted.

   - bpo-39579(7): Change the ending column offset of ‘Attribute’ nodes
     constructed in ‘ast_for_dotted_name’ to point at the end of the
     current node and not at the end of the last ‘NAME’ node.

   - bpo-1635741(8): Port _crypt extension module to multiphase
     initialization ( PEP 489(9)).

   - bpo-1635741(10): Port _contextvars extension module to multiphase
     initialization ( PEP 489(11)).

   - bpo-39510(12): Fix segfault in ‘readinto()’ method on closed
     BufferedReader.

   - bpo-39502(13): Fix *note time.localtime(): 1700. on 64-bit AIX to
     support years before 1902 and after 2038.  Patch by M Felt.

   - bpo-39492(14): Fix a reference cycle in the C Pickler that was
     preventing the garbage collection of deleted, pickled objects.

   - bpo-39453(15): Fixed a possible crash in ‘list.__contains__()’ when
     a list is changed during comparing items.  Patch by Donghee Na.

   - bpo-39434(16): *note floor division: b40. of float operation now
     has a better performance.  Also the message of *note
     ZeroDivisionError: b41. for this operation is updated.  Patch by
     Donghee Na.

   - bpo-1635741(17): Port _codecs extension module to multiphase
     initialization ( PEP 489(18)).

   - bpo-1635741(19): Port _bz2 extension module to multiphase
     initialization ( PEP 489(20)).

   - bpo-1635741(21): Port _abc extension module to multiphase
     initialization ( PEP 489(22)).

   - bpo-39320(23): Replace two complex bytecodes for building dicts
     with two simpler ones.  The new bytecodes ‘DICT_MERGE’ and
     ‘DICT_UPDATE’ have been added The old bytecodes ‘BUILD_MAP_UNPACK’
     and ‘BUILD_MAP_UNPACK_WITH_CALL’ have been removed.

   - bpo-39219(24): Syntax errors raised in the tokenizer now always set
     correct «text» and «offset» attributes.

   - bpo-36051(25): Drop the GIL during large ‘bytes.join’ operations.
     Patch by Bruce Merry.

   - bpo-38960(26): Fix DTrace build issues on FreeBSD. Patch by David
     Carlier.

   - bpo-37207(27): Speed up calls to ‘range()’ by about 30%, by using
     the PEP 590 ‘vectorcall’ calling convention.  Patch by Mark
     Shannon.

   - bpo-36144(28): *note dict: 183. (and *note collections.UserDict:
     1d65.) objects now support PEP 584’s merge (‘|’) and update (‘|=’)
     operators.  Patch by Brandt Bucher.

   - bpo-32856(29): Optimized the idiom for assignment a temporary
     variable in comprehensions.  Now ‘for y in [expr]’ in
     comprehensions is as fast as a simple assignment ‘y = expr’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39382

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39619

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39606

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39386

   (7) https://bugs.python.org/issue?@action=redirect&bpo=39579

   (8) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (9) https://peps.python.org/pep-0489/

   (10) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (11) https://peps.python.org/pep-0489/

   (12) https://bugs.python.org/issue?@action=redirect&bpo=39510

   (13) https://bugs.python.org/issue?@action=redirect&bpo=39502

   (14) https://bugs.python.org/issue?@action=redirect&bpo=39492

   (15) https://bugs.python.org/issue?@action=redirect&bpo=39453

   (16) https://bugs.python.org/issue?@action=redirect&bpo=39434

   (17) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (18) https://peps.python.org/pep-0489/

   (19) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (20) https://peps.python.org/pep-0489/

   (21) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (22) https://peps.python.org/pep-0489/

   (23) https://bugs.python.org/issue?@action=redirect&bpo=39320

   (24) https://bugs.python.org/issue?@action=redirect&bpo=39219

   (25) https://bugs.python.org/issue?@action=redirect&bpo=36051

   (26) https://bugs.python.org/issue?@action=redirect&bpo=38960

   (27) https://bugs.python.org/issue?@action=redirect&bpo=37207

   (28) https://bugs.python.org/issue?@action=redirect&bpo=36144

   (29) https://bugs.python.org/issue?@action=redirect&bpo=32856


File: python.info,  Node: Library<153>,  Next: Documentation<47>,  Prev: Core and Builtins<150>,  Up: Python 3 9 0 alpha 4

1.24.53.3 Library
.................

   - bpo-30566(1): Fix *note IndexError: 173c. when trying to decode an
     invalid string with punycode codec.

   - bpo-39649(2): Remove obsolete check for ‘__args__’ in
     ‘bdb.Bdb.format_stack_entry’.

   - bpo-39648(3): Expanded *note math.gcd(): b0e. and *note math.lcm():
     b0f. to handle multiple arguments.

   - bpo-39681(4): Fix a regression where the C pickle module wouldn’t
     allow unpickling from a file-like object that doesn’t expose a
     readinto() method.

   - bpo-35950(5): Raise *note io.UnsupportedOperation: 1d67. in
     ‘io.BufferedReader.truncate()’ when it is called on a read-only
     *note io.BufferedReader: 1416. instance.

   - bpo-39479(6): Add *note math.lcm(): b0f. function: least common
     multiple.

   - bpo-39674(7): Revert «Do not expose abstract collection classes in
     the collections module» change (bpo-25988(8)).  Aliases to ABC like
     collections.Mapping are kept in Python 3.9 to ease transition from
     Python 2.7, but will be removed in Python 3.10.

   - bpo-39104(9): Fix hanging ProcessPoolExcutor on
     ‘shutdown(wait=False)’ when a task has failed pickling.

   - bpo-39627(10): Fixed TypedDict totality check for inherited keys.

   - bpo-39474(11): Fixed starting position of AST for expressions like
     ‘(a)(b)’, ‘(a)[b]’ and ‘(a).b’.

   - bpo-21016(12): The *note pydoc: ba. and *note trace: 103. modules
     now use the *note sysconfig: e1. module to get the path to the
     Python standard library, to support uncommon installation path like
     ‘/usr/lib64/python3.9/’ on Fedora.  Patch by Jan Matějek.

   - bpo-39590(13): Collections.deque now holds strong references during
     deque.__contains__ and deque.count, fixing crashes.

   - bpo-39586(14): The distutils ‘bdist_msi’ command is deprecated in
     Python 3.9, use ‘bdist_wheel’ (wheel packages) instead.

   - bpo-39595(15): Improved performance of zipfile.Path for files with
     a large number of entries.  Also improved performance and fixed
     minor issue as published with importlib_metadata 1.5(16).

   - bpo-39350(17): Fix regression in *note fractions.Fraction: 213. if
     the numerator and/or the denominator is an *note int: 19b.
     subclass.  The *note math.gcd(): b0e. function is now used to
     normalize the 'numerator' and 'denominator'.  *note math.gcd():
     b0e. always return a *note int: 19b. type.  Previously, the GCD
     type depended on 'numerator' and 'denominator'.

   - bpo-39567(18): Added audit for *note os.walk(): 6d1, *note
     os.fwalk(): d54, *note pathlib.Path.glob(): 538. and *note
     pathlib.Path.rglob(): 539.

   - bpo-39559(19): Remove unused, undocumented argument ‘getters’ from
     *note uuid.getnode(): da2.

   - bpo-38149(20): *note sys.audit(): 1903. is now called only once per
     call of *note glob.glob(): 5a0. and *note glob.iglob(): a0a.

   - bpo-39546(21): Fix a regression in *note ArgumentParser: 1bd. where
     ‘allow_abbrev=False’ was ignored for long options that used a
     prefix character other than «-«.

   - bpo-39450(22): Striped whitespace from docstring before returning
     it from ‘unittest.case.shortDescription()’.

   - bpo-12915(23): A new function ‘resolve_name’ has been added to the
     ‘pkgutil’ module.  This resolves a string of the form ‘'a.b.c.d'’
     or ‘'a.b:c.d'’ to an object.  In the example, ‘a.b’ is a
     package/module and ‘c.d’ is an object within that package/module
     reached via recursive attribute access.

   - bpo-39353(24): The *note binascii.crc_hqx(): 93e. function is no
     longer deprecated.

   - bpo-39493(25): Mark ‘typing.IO.closed’ as a property

   - bpo-39491(26): Add *note typing.Annotated: b39. and
     ‘include_extras’ parameter to *note typing.get_type_hints(): 8c1.
     as part of PEP 593(27).  Patch by Till Varoquaux, documentation by
     Till Varoquaux and Konstantin Kashin.

   - bpo-39485(28): Fix a bug in *note unittest.mock.create_autospec():
     191c. that would complain about the wrong number of arguments for
     custom descriptors defined in an extension module returning
     functions.

   - bpo-38932(29): Mock fully resets child objects on reset_mock().
     Patch by Vegard Stikbakke

   - bpo-39082(30): Allow AsyncMock to correctly patch static/class
     methods

   - bpo-39432(31): Implement PEP-489 algorithm for non-ascii «PyInit_…»
     symbol names in distutils to make it export the correct init symbol
     also on Windows.

   - bpo-18819(32): Omit ‘devmajor’ and ‘devminor’ fields for non-device
     files in *note tarfile: e4. archives, enabling bit-for-bit
     compatibility with GNU ‘tar(1)’.

   - bpo-39349(33): Added a new 'cancel_futures' parameter to *note
     concurrent.futures.Executor.shutdown(): aec. that cancels all
     pending futures which have not started running, instead of waiting
     for them to complete before shutting down the executor.

   - bpo-39274(34): ‘bool(fraction.Fraction)’ now returns a boolean even
     if (numerator != 0) does not return a boolean (ex: numpy number).

   - bpo-34793(35): Remove support for ‘with (await asyncio.lock):’ and
     ‘with (yield from asyncio.lock):’.  The same is correct for
     ‘asyncio.Condition’ and ‘asyncio.Semaphore’.

   - bpo-25597(36): Ensure, if ‘wraps’ is supplied to *note
     unittest.mock.MagicMock: 1091, it is used to calculate return
     values for the magic methods instead of using the default return
     values.  Patch by Karthikeyan Singaravelan.

   - bpo-36350(37): ‘inspect.Signature.parameters’ and
     ‘inspect.BoundArguments.arguments’ are now dicts instead of
     OrderedDicts.  Patch contributed by Rémi Lapeyre.

   - bpo-35727(38): Fix sys.exit() and sys.exit(None) exit code
     propagation when used in multiprocessing.Process.

   - bpo-32173(39): * Add ‘lazycache’ function to ‘__all__’.  * Use
     ‘dict.clear’ to clear the cache.  * Refactoring ‘getline’ function
     and ‘checkcache’ function.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30566

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39649

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39648

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39681

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35950

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39479

   (7) https://bugs.python.org/issue?@action=redirect&bpo=39674

   (8) https://bugs.python.org/issue?@action=redirect&bpo=25988

   (9) https://bugs.python.org/issue?@action=redirect&bpo=39104

   (10) https://bugs.python.org/issue?@action=redirect&bpo=39627

   (11) https://bugs.python.org/issue?@action=redirect&bpo=39474

   (12) https://bugs.python.org/issue?@action=redirect&bpo=21016

   (13) https://bugs.python.org/issue?@action=redirect&bpo=39590

   (14) https://bugs.python.org/issue?@action=redirect&bpo=39586

   (15) https://bugs.python.org/issue?@action=redirect&bpo=39595

   (16) 
https://importlib-metadata.readthedocs.io/en/latest/history.html#v1-5-0

   (17) https://bugs.python.org/issue?@action=redirect&bpo=39350

   (18) https://bugs.python.org/issue?@action=redirect&bpo=39567

   (19) https://bugs.python.org/issue?@action=redirect&bpo=39559

   (20) https://bugs.python.org/issue?@action=redirect&bpo=38149

   (21) https://bugs.python.org/issue?@action=redirect&bpo=39546

   (22) https://bugs.python.org/issue?@action=redirect&bpo=39450

   (23) https://bugs.python.org/issue?@action=redirect&bpo=12915

   (24) https://bugs.python.org/issue?@action=redirect&bpo=39353

   (25) https://bugs.python.org/issue?@action=redirect&bpo=39493

   (26) https://bugs.python.org/issue?@action=redirect&bpo=39491

   (27) https://peps.python.org/pep-0593/

   (28) https://bugs.python.org/issue?@action=redirect&bpo=39485

   (29) https://bugs.python.org/issue?@action=redirect&bpo=38932

   (30) https://bugs.python.org/issue?@action=redirect&bpo=39082

   (31) https://bugs.python.org/issue?@action=redirect&bpo=39432

   (32) https://bugs.python.org/issue?@action=redirect&bpo=18819

   (33) https://bugs.python.org/issue?@action=redirect&bpo=39349

   (34) https://bugs.python.org/issue?@action=redirect&bpo=39274

   (35) https://bugs.python.org/issue?@action=redirect&bpo=34793

   (36) https://bugs.python.org/issue?@action=redirect&bpo=25597

   (37) https://bugs.python.org/issue?@action=redirect&bpo=36350

   (38) https://bugs.python.org/issue?@action=redirect&bpo=35727

   (39) https://bugs.python.org/issue?@action=redirect&bpo=32173


File: python.info,  Node: Documentation<47>,  Next: Tests<47>,  Prev: Library<153>,  Up: Python 3 9 0 alpha 4

1.24.53.4 Documentation
.......................

   - bpo-17422(1): The language reference now specifies restrictions on
     class namespaces.  Adapted from a patch by Ethan Furman.

   - bpo-39572(2): Updated documentation of ‘total’ flag of ‘TypedDict’.

   - bpo-39654(3): In pyclbr doc, update “class” to “module” where
     appropriate and add readmodule comment.  Patch by Hakan Çelik.

   - bpo-39153(4): Clarify refcounting semantics for the following
     functions: - PyObject_SetItem - PyMapping_SetItemString -
     PyDict_SetItem - PyDict_SetItemString

   - bpo-39392(5): Explain that when filling with turtle, overlap
     regions may be left unfilled.

   - bpo-39369(6): Update mmap readline method description.  The fact
     that the readline method does update the file position should not
     be ignored since this might give the impression for the programmer
     that it doesn’t update it.

   - bpo-9056(7): Include subsection in TOC for PDF version of docs.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17422

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39572

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39654

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39153

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39392

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39369

   (7) https://bugs.python.org/issue?@action=redirect&bpo=9056


File: python.info,  Node: Tests<47>,  Next: Build<54>,  Prev: Documentation<47>,  Up: Python 3 9 0 alpha 4

1.24.53.5 Tests
...............

   - bpo-38325(1): Skip tests on non-BMP characters of
     test_winconsoleio.

   - bpo-39502(2): Skip test_zipfile.test_add_file_after_2107() if *note
     time.localtime(): 1700. fails with *note OverflowError: a83.  It is
     the case on AIX 6.1 for example.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38325

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39502


File: python.info,  Node: Build<54>,  Next: Windows<47>,  Prev: Tests<47>,  Up: Python 3 9 0 alpha 4

1.24.53.6 Build
...............

   - bpo-39489(1): Remove ‘COUNT_ALLOCS’ special build.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39489


File: python.info,  Node: Windows<47>,  Next: IDLE<29>,  Prev: Build<54>,  Up: Python 3 9 0 alpha 4

1.24.53.7 Windows
.................

   - bpo-39553(1): Delete unused code related to SxS manifests.

   - bpo-39439(2): Honor the Python path when a virtualenv is active on
     Windows.

   - bpo-39393(3): Improve the error message when attempting to load a
     DLL with unresolved dependencies.

   - bpo-38883(4): *note home(): 1045. and *note expanduser(): 1044. on
     Windows now prefer ‘USERPROFILE’ and no longer use ‘HOME’, which is
     not normally set for regular user accounts.  This makes them again
     behave like *note os.path.expanduser(): c0b, which was changed to
     ignore ‘HOME’ in 3.8, see bpo-36264(5).

   - bpo-39185(6): The build.bat script has additional options for
     very-quiet output (-q) and very-verbose output (-vv)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39553

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39439

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39393

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38883

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36264

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39185


File: python.info,  Node: IDLE<29>,  Next: C API<49>,  Prev: Windows<47>,  Up: Python 3 9 0 alpha 4

1.24.53.8 IDLE
..............

   - bpo-39663(1): Add tests for pyparse find_good_parse_start().

   - bpo-39600(2): In the font configuration window, remove duplicated
     font names.

   - bpo-30780(3): Add remaining configdialog tests for buttons and
     highlights and keys tabs.

   - bpo-39388(4): IDLE Settings Cancel button now cancels pending
     changes

   - bpo-38792(5): Close an IDLE shell calltip if a *note
     KeyboardInterrupt: bc7. or shell restart occurs.  Patch by Zackery
     Spytz.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39663

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39600

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30780

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39388

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38792


File: python.info,  Node: C API<49>,  Prev: IDLE<29>,  Up: Python 3 9 0 alpha 4

1.24.53.9 C API
...............

   - bpo-35081(1): Move the ‘bytes_methods.h’ header file to the
     internal C API as ‘pycore_bytes_methods.h’: it only contains
     private symbols (prefixed by ‘_Py’), except of the
     ‘PyDoc_STRVAR_shared()’ macro.

   - bpo-35081(2): Move the ‘dtoa.h’ header file to the internal C API
     as ‘pycore_dtoa.h’: it only contains private functions (prefixed by
     ‘_Py’).  The *note math: 92. and *note cmath: 19. modules must now
     be compiled with the ‘Py_BUILD_CORE’ macro defined.

   - bpo-39573(3): Add *note Py_SET_SIZE(): 987. function to set the
     size of an object.

   - bpo-39500(4): *note PyUnicode_IsIdentifier(): 1d6e. does not call
     *note Py_FatalError(): b7c. anymore if the string is not ready.

   - bpo-39573(5): Add *note Py_SET_TYPE(): 985. function to set the
     type of an object.

   - bpo-39573(6): Add a *note Py_SET_REFCNT(): aaa. function to set the
     reference counter of an object.

   - bpo-39542(7): Convert *note PyType_HasFeature(): 1d24, *note
     PyType_Check(): 1d6f. and *note PyType_CheckExact(): 1d70. macros
     to static inline functions.

   - bpo-39542(8): In the limited C API, ‘PyObject_INIT()’ and
     ‘PyObject_INIT_VAR()’ are now defined as aliases to *note
     PyObject_Init(): c62. and *note PyObject_InitVar(): 1d28. to make
     their implementation opaque.  It avoids to leak implementation
     details in the limited C API. Exclude the following functions from
     the limited C API: ‘_Py_NewReference()’, ‘_Py_ForgetReference()’,
     ‘_PyTraceMalloc_NewReference()’ and ‘_Py_GetRefTotal()’.

   - bpo-39542(9): Exclude trashcan mechanism from the limited C API: it
     requires access to PyTypeObject and PyThreadState structure fields,
     whereas these structures are opaque in the limited C API.

   - bpo-39511(10): The *note PyThreadState_Clear(): 1979. function now
     calls the ‘PyThreadState.on_delete’ callback.  Previously, that
     happened in *note PyThreadState_Delete(): 1d71.

   - bpo-38076(11): Fix to clear the interpreter state only after
     clearing module globals to guarantee module state access from C
     Extensions during runtime destruction

   - bpo-39245(12): The Vectorcall API (PEP 590) was made public, adding
     the functions ‘PyObject_Vectorcall’, ‘PyObject_VectorcallMethod’,
     ‘PyVectorcall_Function’, ‘PyObject_CallOneArg’,
     ‘PyObject_CallMethodNoArgs’, ‘PyObject_CallMethodOneArg’,
     ‘PyObject_FastCallDict’, and the flag ‘Py_TPFLAGS_HAVE_VECTORCALL’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35081

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35081

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39500

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39573

   (7) https://bugs.python.org/issue?@action=redirect&bpo=39542

   (8) https://bugs.python.org/issue?@action=redirect&bpo=39542

   (9) https://bugs.python.org/issue?@action=redirect&bpo=39542

   (10) https://bugs.python.org/issue?@action=redirect&bpo=39511

   (11) https://bugs.python.org/issue?@action=redirect&bpo=38076

   (12) https://bugs.python.org/issue?@action=redirect&bpo=39245


File: python.info,  Node: Python 3 9 0 alpha 3,  Next: Python 3 9 0 alpha 2,  Prev: Python 3 9 0 alpha 4,  Up: Changelog

1.24.54 Python 3.9.0 alpha 3
----------------------------

'Release date: 2020-01-24'

* Menu:

* Core and Builtins: Core and Builtins<151>.
* Library: Library<154>.
* Documentation: Documentation<48>.
* Build: Build<55>.
* IDLE: IDLE<30>.
* C API: C API<50>.


File: python.info,  Node: Core and Builtins<151>,  Next: Library<154>,  Up: Python 3 9 0 alpha 3

1.24.54.1 Core and Builtins
...........................

   - bpo-39427(1): Document all possibilities for the ‘-X’ options in
     the command line help section.  Patch by Pablo Galindo.

   - bpo-39421(2): Fix possible crashes when operating with the
     functions in the *note heapq: 6d. module and custom comparison
     operators.

   - bpo-39386(3): Prevent double awaiting of async iterator.

   - bpo-17005(4): Add ‘functools.TopologicalSorter’ to the *note
     functools: 63. module to offers functionality to perform
     topological sorting of graphs.  Patch by Pablo Galindo, Tim Peters
     and Larry Hastings.

   - bpo-39320(5): Replace four complex bytecodes for building sequences
     with three simpler ones.

     The following four bytecodes have been removed:

        * BUILD_LIST_UNPACK

        * BUILD_TUPLE_UNPACK

        * BUILD_SET_UNPACK

        * BUILD_TUPLE_UNPACK_WITH_CALL

     The following three bytecodes have been added:

        * LIST_TO_TUPLE

        * LIST_EXTEND

        * SET_UPDATE

   - bpo-39336(6): Import loaders which publish immutable module objects
     can now publish immutable packages in addition to individual
     modules.

   - bpo-39322(7): Added a new function *note gc.is_finalized(): afb. to
     check if an object has been finalized by the garbage collector.
     Patch by Pablo Galindo.

   - bpo-39048(8): Improve the displayed error message when incorrect
     types are passed to ‘async with’ statements by looking up the
     ‘__aenter__()’ special method before the ‘__aexit__()’ special
     method when entering an asynchronous context manager.  Patch by
     Géry Ogam.

   - bpo-39235(9): Fix AST end location for lone generator expression in
     function call, e.g.  f(i for i in a).

   - bpo-39209(10): Correctly handle multi-line tokens in interactive
     mode.  Patch by Pablo Galindo.

   - bpo-1635741(11): Port _json extension module to multiphase
     initialization ( PEP 489(12)).

   - bpo-39216(13): Fix constant folding optimization for positional
     only arguments - by Anthony Sottile.

   - bpo-39215(14): Fix ‘SystemError’ when nested function has
     annotation on positional-only argument - by Anthony Sottile.

   - bpo-39200(15): Correct the error message when calling the *note
     min(): 110d. or *note max(): 110e. with no arguments.  Patch by
     Donghee Na.

   - bpo-39200(16): Correct the error message when trying to construct
     *note range: b3f. objects with no arguments.  Patch by Pablo
     Galindo.

   - bpo-39166(17): Fix incorrect line execution reporting in trace
     functions when tracing the last iteration of asynchronous for
     loops.  Patch by Pablo Galindo.

   - bpo-39114(18): Fix incorrect line execution reporting in trace
     functions when tracing exception handlers with name binding.  Patch
     by Pablo Galindo.

   - bpo-39156(19): Split the COMPARE_OP bytecode instruction into four
     distinct instructions.

        * COMPARE_OP for rich comparisons

        * IS_OP for “is” and “is not” tests

        * CONTAINS_OP for “in” and “is not” tests

        * JUMP_IF_NOT_EXC_MATCH for checking exceptions in “try-except”
          statements.

     This improves the clarity of the interpreter and should provide a
     modest speedup.

   - bpo-38588(20): Fix possible crashes in dict and list when calling
     *note PyObject_RichCompareBool(): 1d74.

   - bpo-13601(21): By default, ‘sys.stderr’ is line-buffered now, even
     if ‘stderr’ is redirected to a file.  You can still make
     ‘sys.stderr’ unbuffered by passing the *note -u: 1d75. command-line
     option or setting the *note PYTHONUNBUFFERED: 1d76. environment
     variable.

     (Contributed by Jendrik Seipp in bpo-13601(22).)

   - bpo-38610(23): Fix possible crashes in several list methods by
     holding strong references to list elements when calling *note
     PyObject_RichCompareBool(): 1d74.

   - bpo-32021(24): Include brotli .br encoding in mimetypes
     encodings_map

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39427

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39421

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39386

   (4) https://bugs.python.org/issue?@action=redirect&bpo=17005

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39320

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39336

   (7) https://bugs.python.org/issue?@action=redirect&bpo=39322

   (8) https://bugs.python.org/issue?@action=redirect&bpo=39048

   (9) https://bugs.python.org/issue?@action=redirect&bpo=39235

   (10) https://bugs.python.org/issue?@action=redirect&bpo=39209

   (11) https://bugs.python.org/issue?@action=redirect&bpo=1635741

   (12) https://peps.python.org/pep-0489/

   (13) https://bugs.python.org/issue?@action=redirect&bpo=39216

   (14) https://bugs.python.org/issue?@action=redirect&bpo=39215

   (15) https://bugs.python.org/issue?@action=redirect&bpo=39200

   (16) https://bugs.python.org/issue?@action=redirect&bpo=39200

   (17) https://bugs.python.org/issue?@action=redirect&bpo=39166

   (18) https://bugs.python.org/issue?@action=redirect&bpo=39114

   (19) https://bugs.python.org/issue?@action=redirect&bpo=39156

   (20) https://bugs.python.org/issue?@action=redirect&bpo=38588

   (21) https://bugs.python.org/issue?@action=redirect&bpo=13601

   (22) https://bugs.python.org/issue?@action=redirect&bpo=13601

   (23) https://bugs.python.org/issue?@action=redirect&bpo=38610

   (24) https://bugs.python.org/issue?@action=redirect&bpo=32021


File: python.info,  Node: Library<154>,  Next: Documentation<48>,  Prev: Core and Builtins<151>,  Up: Python 3 9 0 alpha 3

1.24.54.2 Library
.................

   - bpo-39430(1): Fixed race condition in lazy imports in *note
     tarfile: e4.

   - bpo-39413(2): The *note os.unsetenv(): 25c. function is now also
     available on Windows.

   - bpo-39390(3): Fixed a regression with the ‘ignore’ callback of
     *note shutil.copytree(): c20.  The argument types are now ‘str’ and
     ‘List[str]’ again.

   - bpo-39395(4): The *note os.putenv(): 25b. and *note os.unsetenv():
     25c. functions are now always available.

   - bpo-39406(5): If ‘setenv()’ C function is available, *note
     os.putenv(): 25b. is now implemented with ‘setenv()’ instead of
     ‘putenv()’, so Python doesn’t have to handle the environment
     variable memory.

   - bpo-39396(6): Fix ‘math.nextafter(-0.0, +0.0)’ on AIX 7.1.

   - bpo-29435(7): Allow *note tarfile.is_tarfile(): 1bc3. to be used
     with file and file-like objects, like *note zipfile.is_zipfile():
     1532.  Patch by William Woodruff.

   - bpo-39377(8): Removed ‘encoding’ option from *note json.loads():
     b50.  It has been deprecated since Python 3.1.

   - bpo-39389(9): Write accurate compression level metadata in *note
     gzip: 6b. archives, rather than always signaling maximum
     compression.

   - bpo-39366(10): The previously deprecated ‘xpath()’ and ‘xgtitle()’
     methods of ‘nntplib.NNTP’ have been removed.

   - bpo-39357(11): Remove the 'buffering' parameter of *note
     bz2.BZ2File: a68.  Since Python 3.0, it was ignored and using it
     was emitting *note DeprecationWarning: 1a3.  Pass an open file
     object, to control how the file is opened.  The 'compresslevel'
     parameter becomes keyword-only.

   - bpo-39353(12): Deprecate binhex4 and hexbin4 standards.  Deprecate
     the ‘binhex’ module and the following *note binascii: 11.
     functions: ‘b2a_hqx()’, ‘a2b_hqx()’, ‘rlecode_hqx()’,
     ‘rledecode_hqx()’, *note crc_hqx(): 93e.

   - bpo-39351(13): Remove ‘base64.encodestring()’ and
     ‘base64.decodestring()’, aliases deprecated since Python 3.1: use
     *note base64.encodebytes(): b4e. and *note base64.decodebytes():
     b4f. instead.

   - bpo-39350(14): Remove ‘fractions.gcd()’ function, deprecated since
     Python 3.5 (bpo-22486(15)): use *note math.gcd(): b0e. instead.

   - bpo-39329(16): *note LMTP: b2b. constructor now has an optional
     'timeout' parameter.  Patch by Donghee Na.

   - bpo-39313(17): Add a new ‘exec_function’ option ('–exec-function'
     in the CLI) to ‘RefactoringTool’ for making ‘exec’ a function.
     Patch by Batuhan Taskaya.

   - bpo-39259(18): *note FTP_TLS: af9. and *note FTP_TLS: af9. now
     raise a *note ValueError: 2ec. if the given timeout for their
     constructor is zero to prevent the creation of a non-blocking
     socket.  Patch by Donghee Na.

   - bpo-39259(19): *note SMTP: b29. and *note SMTP_SSL: b2a. now raise
     a *note ValueError: 2ec. if the given timeout for their constructor
     is zero to prevent the creation of a non-blocking socket.  Patch by
     Donghee Na.

   - bpo-39310(20): Add *note math.ulp(): b10.: return the value of the
     least significant bit of a float.

   - bpo-39297(21): Improved performance of importlib.metadata
     distribution discovery and resilients to inaccessible sys.path
     entries (importlib_metadata v1.4.0).

   - bpo-39259(22): ‘NNTP’ and ‘NNTP_SSL’ now raise a *note ValueError:
     2ec. if the given timeout for their constructor is zero to prevent
     the creation of a non-blocking socket.  Patch by Donghee Na.

   - bpo-38901(23): When you specify prompt=”.” or equivalently python
     -m venv –prompt .  … the basename of the current directory is used
     to set the created venv’s prompt when it’s activated.

   - bpo-39288(24): Add *note math.nextafter(): 6c1.: return the next
     floating-point value after 'x' towards 'y'.

   - bpo-39259(25): *note POP3: b1f. and *note POP3_SSL: b20. now raise
     a *note ValueError: 2ec. if the given timeout for their constructor
     is zero to prevent the creation of a non-blocking socket.  Patch by
     Donghee Na.

   - bpo-39242(26): Updated the Gmane domain from news.gmane.org to
     news.gmane.io which is used for examples of ‘NNTP’ news reader
     server and nntplib tests.

   - bpo-35292(27): Proxy the ‘SimpleHTTPRequestHandler.guess_type’ to
     ‘mimetypes.guess_type’ so the ‘mimetypes.init’ is called lazily to
     avoid unnecessary costs when *note http.server: 76. module is
     imported.

   - bpo-39239(28): The *note select.epoll.unregister(): b55. method no
     longer ignores the *note EBADF: b56. error.

   - bpo-38907(29): In http.server script, restore binding to IPv4 on
     Windows.

   - bpo-39152(30): Fix ttk.Scale.configure([name]) to return
     configuration tuple for name or all options.  Giovanni Lombardo
     contributed part of the patch.

   - bpo-39198(31): If an exception were to be thrown in
     ‘Logger.isEnabledFor’ (say, by asyncio timeouts or stopit) , the
     ‘logging’ global lock may not be released appropriately, resulting
     in deadlock.  This change wraps that block of code with
     ‘try...finally’ to ensure the lock is released.

   - bpo-39191(32): Perform a check for running loop before starting a
     new task in ‘loop.run_until_complete()’ to fail fast; it prevents
     the side effect of new task spawning before exception raising.

   - bpo-38871(33): Correctly parenthesize filter-based statements that
     contain lambda expressions in ‘lib2to3’.  Patch by Donghee Na.

   - bpo-39142(34): A change was made to logging.config.dictConfig to
     avoid converting instances of named tuples to ConvertingTuple.
     It’s assumed that named tuples are too specialised to be treated
     like ordinary tuples; if a user of named tuples requires
     ConvertingTuple functionality, they will have to implement that
     themselves in their named tuple class.

   - bpo-39158(35): ast.literal_eval() now supports empty sets.

   - bpo-39129(36): Fix import path for ‘asyncio.TimeoutError’

   - bpo-39057(37): ‘urllib.request.proxy_bypass_environment()’ now
     ignores leading dots and no longer ignores a trailing newline.

   - bpo-39056(38): Fixed handling invalid warning category in the -W
     option.  No longer import the re module if it is not needed.

   - bpo-39055(39): *note base64.b64decode(): 1d78. with ‘validate=True’
     raises now a binascii.Error if the input ends with a single ‘\n’.

   - bpo-21600(40): Fix ‘mock.patch.stopall()’ to stop active patches
     that were created with ‘mock.patch.dict()’.

   - bpo-39019(41): Implement dummy ‘__class_getitem__’ for *note
     tempfile.SpooledTemporaryFile: 8a3.

   - bpo-39019(42): Implement dummy ‘__class_getitem__’ for
     ‘subprocess.Popen’, ‘subprocess.CompletedProcess’

   - bpo-38914(43): Adjusted the wording of the warning issued by
     distutils” ‘check’ command when the ‘author’ and ‘maintainer’
     fields are supplied but no corresponding e-mail field
     (‘author_email’ or ‘maintainer_email’) is found.  The wording now
     reflects the fact that these fields are suggested, but not
     required.  Patch by Juergen Gmach.

   - bpo-38878(44): Fixed __subclasshook__ of *note os.PathLike: e4d. to
     return a correct result upon inheritance.  Patch by Bar Harel.

   - bpo-38615(45): *note IMAP4: b01. and *note IMAP4_SSL: b02. now have
     an optional 'timeout' parameter for their constructors.  Also, the
     *note open(): b03. method now has an optional 'timeout' parameter
     with this change.  The overridden methods of *note IMAP4_SSL: b02.
     and *note IMAP4_stream: b04. were applied to this change.  Patch by
     Donghee Na.

   - bpo-35182(46): Fixed ‘Popen.communicate()’ subsequent call crash
     when the child process has already closed any piped standard
     stream, but still continues to be running.  Patch by Andriy
     Maletsky.

   - bpo-38630(47): On Unix, *note subprocess.Popen.send_signal(): 15e5.
     now polls the process status.  Polling reduces the risk of sending
     a signal to the wrong process if the process completed, the *note
     subprocess.Popen.returncode: c85. attribute is still ‘None’, and
     the pid has been reassigned (recycled) to a new different process.

   - bpo-38536(48): Removes trailing space in formatted currency with
     ‘international=True’ and a locale with symbol following value.
     E.g.  ‘locale.currency(12.34, international=True)’ returned ‘'12,34
     EUR '’ instead of ‘'12,34 EUR'’.

   - bpo-38473(49): Use signature from inner mock for autospecced
     methods attached with ‘unittest.mock.attach_mock()’.  Patch by
     Karthikeyan Singaravelan.

   - bpo-38361(50): Fixed an issue where ‘ident’ could include a leading
     path separator when *note syslog.openlog(): 761. was called without
     arguments.

   - bpo-38293(51): Add *note copy.copy(): 758. and *note
     copy.deepcopy(): d67. support to *note property(): 4b4. objects.

   - bpo-37958(52): Added the pstats.Stats.get_profile_dict() method to
     return the profile data as a StatsProfile instance.

   - bpo-28367(53): Termios magic constants for the following baud
     rates: - B500000 - B576000 - B921600 - B1000000 - B1152000 -
     B1500000 - B2000000 - B2500000 - B3000000 - B3500000 - B4000000
     Patch by Andrey Smirnov

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39430

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39413

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39390

   (4) https://bugs.python.org/issue?@action=redirect&bpo=39395

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39406

   (6) https://bugs.python.org/issue?@action=redirect&bpo=39396

   (7) https://bugs.python.org/issue?@action=redirect&bpo=29435

   (8) https://bugs.python.org/issue?@action=redirect&bpo=39377

   (9) https://bugs.python.org/issue?@action=redirect&bpo=39389

   (10) https://bugs.python.org/issue?@action=redirect&bpo=39366

   (11) https://bugs.python.org/issue?@action=redirect&bpo=39357

   (12) https://bugs.python.org/issue?@action=redirect&bpo=39353

   (13) https://bugs.python.org/issue?@action=redirect&bpo=39351

   (14) https://bugs.python.org/issue?@action=redirect&bpo=39350

   (15) https://bugs.python.org/issue?@action=redirect&bpo=22486

   (16) https://bugs.python.org/issue?@action=redirect&bpo=39329

   (17) https://bugs.python.org/issue?@action=redirect&bpo=39313

   (18) https://bugs.python.org/issue?@action=redirect&bpo=39259

   (19) https://bugs.python.org/issue?@action=redirect&bpo=39259

   (20) https://bugs.python.org/issue?@action=redirect&bpo=39310

   (21) https://bugs.python.org/issue?@action=redirect&bpo=39297

   (22) https://bugs.python.org/issue?@action=redirect&bpo=39259

   (23) https://bugs.python.org/issue?@action=redirect&bpo=38901

   (24) https://bugs.python.org/issue?@action=redirect&bpo=39288

   (25) https://bugs.python.org/issue?@action=redirect&bpo=39259

   (26) https://bugs.python.org/issue?@action=redirect&bpo=39242

   (27) https://bugs.python.org/issue?@action=redirect&bpo=35292

   (28) https://bugs.python.org/issue?@action=redirect&bpo=39239

   (29) https://bugs.python.org/issue?@action=redirect&bpo=38907

   (30) https://bugs.python.org/issue?@action=redirect&bpo=39152

   (31) https://bugs.python.org/issue?@action=redirect&bpo=39198

   (32) https://bugs.python.org/issue?@action=redirect&bpo=39191

   (33) https://bugs.python.org/issue?@action=redirect&bpo=38871

   (34) https://bugs.python.org/issue?@action=redirect&bpo=39142

   (35) https://bugs.python.org/issue?@action=redirect&bpo=39158

   (36) https://bugs.python.org/issue?@action=redirect&bpo=39129

   (37) https://bugs.python.org/issue?@action=redirect&bpo=39057

   (38) https://bugs.python.org/issue?@action=redirect&bpo=39056

   (39) https://bugs.python.org/issue?@action=redirect&bpo=39055

   (40) https://bugs.python.org/issue?@action=redirect&bpo=21600

   (41) https://bugs.python.org/issue?@action=redirect&bpo=39019

   (42) https://bugs.python.org/issue?@action=redirect&bpo=39019

   (43) https://bugs.python.org/issue?@action=redirect&bpo=38914

   (44) https://bugs.python.org/issue?@action=redirect&bpo=38878

   (45) https://bugs.python.org/issue?@action=redirect&bpo=38615

   (46) https://bugs.python.org/issue?@action=redirect&bpo=35182

   (47) https://bugs.python.org/issue?@action=redirect&bpo=38630

   (48) https://bugs.python.org/issue?@action=redirect&bpo=38536

   (49) https://bugs.python.org/issue?@action=redirect&bpo=38473

   (50) https://bugs.python.org/issue?@action=redirect&bpo=38361

   (51) https://bugs.python.org/issue?@action=redirect&bpo=38293

   (52) https://bugs.python.org/issue?@action=redirect&bpo=37958

   (53) https://bugs.python.org/issue?@action=redirect&bpo=28367


File: python.info,  Node: Documentation<48>,  Next: Build<55>,  Prev: Library<154>,  Up: Python 3 9 0 alpha 3

1.24.54.3 Documentation
.......................

   - bpo-39381(1): Mention in docs that *note asyncio.get_event_loop():
     2f2. implicitly creates new event loop only if called from the main
     thread.

   - bpo-38918(2): Add an entry for ‘__module__’ in the «function» &
     «method» sections of the *note inspect: 82. docs” *note Types and
     members: 1d7a. table.

   - bpo-3530(3): In the *note ast: 9. module documentation, fix a
     misleading ‘NodeTransformer’ example and add advice on when to use
     the ‘fix_missing_locations’ function.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39381

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38918

   (3) https://bugs.python.org/issue?@action=redirect&bpo=3530


File: python.info,  Node: Build<55>,  Next: IDLE<30>,  Prev: Documentation<48>,  Up: Python 3 9 0 alpha 3

1.24.54.4 Build
...............

   - bpo-39395(1): On non-Windows platforms, the ‘setenv()’ and
     ‘unsetenv()’ functions are now required to build Python.

   - bpo-39160(2): Updated the documentation in ‘./configure --help’ to
     show default values, reference documentation where required and add
     additional explanation where needed.

   - bpo-39144(3): The ctags and etags build targets both include
     Modules/_ctypes and Python standard library source files.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39395

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39160

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39144


File: python.info,  Node: IDLE<30>,  Next: C API<50>,  Prev: Build<55>,  Up: Python 3 9 0 alpha 3

1.24.54.5 IDLE
..............

   - bpo-39050(1): Make IDLE Settings dialog Help button work again.

   - bpo-34118(2): Tag memoryview, range, and tuple as classes, the same
     as list, etcetera, in the library manual built-in functions list.

   - bpo-32989(3): Add tests for editor newline_and_indent_event method.
     Remove dead code from pyparse find_good_parse_start method.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39050

   (2) https://bugs.python.org/issue?@action=redirect&bpo=34118

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32989


File: python.info,  Node: C API<50>,  Prev: IDLE<30>,  Up: Python 3 9 0 alpha 3

1.24.54.6 C API
...............

   - bpo-39372(1): Clean header files of interfaces defined but with no
     implementation.  The public API symbols being removed are:
     ‘_PyBytes_InsertThousandsGroupingLocale’,
     ‘_PyBytes_InsertThousandsGrouping’, ‘_Py_InitializeFromArgs’,
     ‘_Py_InitializeFromWideArgs’, ‘_PyFloat_Repr’, ‘_PyFloat_Digits’,
     ‘_PyFloat_DigitsInit’, ‘PyFrame_ExtendStack’,
     ‘_PyAIterWrapper_Type’, ‘PyNullImporter_Type’, ‘PyCmpWrapper_Type’,
     ‘PySortWrapper_Type’, ‘PyNoArgsFunction’.

   - bpo-39164(2): Add a private ‘_PyErr_GetExcInfo()’ function to
     retrieve exception information of the specified Python thread
     state.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39372

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39164


File: python.info,  Node: Python 3 9 0 alpha 2,  Next: Python 3 9 0 alpha 1,  Prev: Python 3 9 0 alpha 3,  Up: Changelog

1.24.55 Python 3.9.0 alpha 2
----------------------------

'Release date: 2019-12-18'

* Menu:

* Security: Security<41>.
* Core and Builtins: Core and Builtins<152>.
* Library: Library<155>.
* Documentation: Documentation<49>.
* Tests: Tests<48>.
* Build: Build<56>.
* Windows: Windows<48>.
* macOS: macOS<37>.
* IDLE: IDLE<31>.
* C API: C API<51>.


File: python.info,  Node: Security<41>,  Next: Core and Builtins<152>,  Up: Python 3 9 0 alpha 2

1.24.55.1 Security
..................

   - bpo-38945(1): Newline characters have been escaped when performing
     uu encoding to prevent them from overflowing into to content
     section of the encoded file.  This prevents malicious or accidental
     modification of data during the decoding process.

   - bpo-37228(2): Due to significant security concerns, the
     'reuse_address' parameter of *note
     asyncio.loop.create_datagram_endpoint(): 93d. is no longer
     supported.  This is because of the behavior of ‘SO_REUSEADDR’ in
     UDP. For more details, see the documentation for
     ‘loop.create_datagram_endpoint()’.  (Contributed by Kyle Stanley,
     Antoine Pitrou, and Yury Selivanov in bpo-37228(3).)

   - bpo-38804(4): Fixes a ReDoS vulnerability in *note http.cookiejar:
     74.  Patch by Ben Caller.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38945

   (2) https://bugs.python.org/issue?@action=redirect&bpo=37228

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37228

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38804


File: python.info,  Node: Core and Builtins<152>,  Next: Library<155>,  Prev: Security<41>,  Up: Python 3 9 0 alpha 2

1.24.55.2 Core and Builtins
...........................

   - bpo-39028(1): Slightly improve the speed of keyword argument
     parsing with many kwargs by strengthening the assumption that
     kwargs are interned strings.

   - bpo-39080(2): Fix the value of 'end_col_offset' for Starred
     Expression AST nodes when they are among the elements in the 'args'
     attribute of Call AST nodes.

   - bpo-39031(3): When parsing an «elif» node, lineno and col_offset of
     the node now point to the «elif» keyword and not to its condition,
     making it consistent with the «if» node.  Patch by Lysandros
     Nikolaou.

   - bpo-20443(4): In Python 3.9.0a1, sys.argv[0] was made an absolute
     path if a filename was specified on the command line.  Revert this
     change, since most users expect sys.argv to be unmodified.

   - bpo-39008(5): *note PySys_Audit(): 613. now requires ‘Py_ssize_t’
     to be used for size arguments in the format string, regardless of
     whether ‘PY_SSIZE_T_CLEAN’ was defined at include time.

   - bpo-38673(6): In REPL mode, don’t switch to PS2 if the line starts
     with comment or whitespace.  Based on work by Batuhan Taşkaya.

   - bpo-38922(7): Calling ‘replace’ on a code object now raises the
     ‘code.__new__’ audit event.

   - bpo-38920(8): Add audit hooks for when *note sys.excepthook(): a0e.
     and *note sys.unraisablehook(): 508. are invoked.

   - bpo-38892(9): Improve documentation for audit events table and
     functions.

   - bpo-38852(10): Set the thread stack size to 8 Mb for debug builds
     on android platforms.

   - bpo-38858(11): Each Python subinterpreter now has its own «small
     integer singletons»: numbers in [-5; 257] range.  It is no longer
     possible to change the number of small integers at build time by
     overriding ‘NSMALLNEGINTS’ and ‘NSMALLPOSINTS’ macros: macros
     should now be modified manually in ‘pycore_pystate.h’ header file.

   - bpo-36854(12): The garbage collector state becomes per interpreter
     (‘PyInterpreterState.gc’), rather than being global
     (‘_PyRuntimeState.gc’).

   - bpo-38835(13): The ‘PyFPE_START_PROTECT()’ and
     ‘PyFPE_END_PROTECT()’ macros are empty: they have been doing
     nothing for the last year, so stop using them.

   - bpo-38328(14): Sped up the creation time of constant *note list:
     24d. and *note set: 184. displays.  Patch by Brandt Bucher.

   - bpo-38707(15): ‘MainThread.native_id’ is now correctly reset in
     child processes spawned using *note multiprocessing.Process: 252,
     instead of retaining the parent’s value.

   - bpo-38629(16): Added ‘__floor__’ and ‘__ceil__’ methods to float
     object.  Patch by Batuhan Taşkaya.

   - bpo-27145(17): int + int and int - int operators can now return
     small integer singletons.  Patch by hongweipeng.

   - bpo-38021(18): Provide a platform tag for AIX that is sufficient
     for PEP425 binary distribution identification.  Patch by Michael
     Felt.

   - bpo-35409(19): Ignore GeneratorExit exceptions when throwing an
     exception into the aclose coroutine of an asynchronous generator.

   - bpo-33387(20): Removed WITH_CLEANUP_START, WITH_CLEANUP_FINISH,
     BEGIN_FINALLY, END_FINALLY, CALL_FINALLY and POP_FINALLY bytecodes.
     Replaced with RERAISE and WITH_EXCEPT_START bytecodes.  The
     compiler now generates different code for exceptional and
     non-exceptional branches for “with” and “try-except” statements.
     For “try-finally” statements the “finally” block is replicated for
     each exit from the “try” body.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39028

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39080

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39031

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20443

   (5) https://bugs.python.org/issue?@action=redirect&bpo=39008

   (6) https://bugs.python.org/issue?@action=redirect&bpo=38673

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38922

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38920

   (9) https://bugs.python.org/issue?@action=redirect&bpo=38892

   (10) https://bugs.python.org/issue?@action=redirect&bpo=38852

   (11) https://bugs.python.org/issue?@action=redirect&bpo=38858

   (12) https://bugs.python.org/issue?@action=redirect&bpo=36854

   (13) https://bugs.python.org/issue?@action=redirect&bpo=38835

   (14) https://bugs.python.org/issue?@action=redirect&bpo=38328

   (15) https://bugs.python.org/issue?@action=redirect&bpo=38707

   (16) https://bugs.python.org/issue?@action=redirect&bpo=38629

   (17) https://bugs.python.org/issue?@action=redirect&bpo=27145

   (18) https://bugs.python.org/issue?@action=redirect&bpo=38021

   (19) https://bugs.python.org/issue?@action=redirect&bpo=35409

   (20) https://bugs.python.org/issue?@action=redirect&bpo=33387


File: python.info,  Node: Library<155>,  Next: Documentation<49>,  Prev: Core and Builtins<152>,  Up: Python 3 9 0 alpha 2

1.24.55.3 Library
.................

   - bpo-39033(1): Fix *note NameError: 452. in *note zipimport: 138.
     Patch by Karthikeyan Singaravelan.

   - bpo-39022(2): Update importlib.metadata to include improvements
     from importlib_metadata 1.3 including better serialization of
     EntryPoints and improved documentation for custom finders.

   - bpo-39006(3): Fix asyncio when the ssl module is missing: only
     check for ssl.SSLSocket instance if the ssl module is available.

   - bpo-38708(4): Fix a potential IndexError in email parser when
     parsing an empty msg-id.

   - bpo-38698(5): Add a new ‘InvalidMessageID’ token to email parser to
     represent invalid Message-ID headers.  Also, add defects when there
     is remaining value after parsing the header.

   - bpo-38994(6): Implement ‘__class_getitem__’ for ‘os.PathLike’,
     ‘pathlib.Path’.

   - bpo-38979(7): Return class from ‘ContextVar.__class_getitem__’ to
     simplify subclassing.

   - bpo-38978(8): Implement ‘__class_getitem__’ on asyncio objects
     (Future, Task, Queue).  Patch by Batuhan Taskaya.

   - bpo-38916(9): *note array.array: 4bf.: Remove ‘tostring()’ and
     ‘fromstring()’ methods.  They were aliases to ‘tobytes()’ and
     ‘frombytes()’, deprecated since Python 3.2.

   - bpo-38986(10): Make repr of C accelerated TaskWakeupMethWrapper the
     same as of pure Python version.

   - bpo-38982(11): Fix asyncio ‘PidfdChildWatcher’: handle ‘waitpid()’
     error.  If ‘waitpid()’ is called elsewhere, ‘waitpid()’ call fails
     with *note ChildProcessError: 125a.: use return code 255 in this
     case, and log a warning.  It ensures that the pidfd file descriptor
     is closed if this error occurs.

   - bpo-38529(12): Drop too noisy asyncio warning about deletion of a
     stream without explicit ‘.close()’ call.

   - bpo-27413(13): Added ability to pass through ‘ensure_ascii’ options
     to json.dumps in the ‘json.tool’ command-line interface.

   - bpo-38634(14): The *note readline: bf. module now detects if Python
     is linked to libedit at runtime on all platforms.  Previously, the
     check was only done on macOS.

   - bpo-33684(15): Fix ‘json.tool’ failed to read a JSON file with
     non-ASCII characters when locale encoding is not UTF-8.

   - bpo-38698(16): Prevent UnboundLocalError to pop up in
     parse_message_id.

     parse_message_id() was improperly using a token defined inside an
     exception handler, which was raising ‘UnboundLocalError’ on parsing
     an invalid value.  Patch by Claudiu Popa.

   - bpo-38927(17): Use ‘python -m pip’ instead of ‘pip’ to upgrade
     dependencies in venv.

   - bpo-26730(18): Fix ‘SpooledTemporaryFile.rollover()’ might corrupt
     the file when it is in text mode.  Patch by Serhiy Storchaka.

   - bpo-38881(19): random.choices() now raises a ValueError when all
     the weights are zero.

   - bpo-38876(20): Raise pickle.UnpicklingError when loading an item
     from memo for invalid input.

     The previous code was raising a ‘KeyError’ for both the Python and
     C implementation.  This was caused by the specified index of an
     invalid input which did not exist in the memo structure, where the
     pickle stores what objects it has seen.  The malformed input would
     have caused either a ‘BINGET’ or ‘LONG_BINGET’ load from the memo,
     leading to a ‘KeyError’ as the determined index was bogus.  Patch
     by Claudiu Popa.

   - bpo-38688(21): Calling func:‘shutil.copytree’ to copy a directory
     tree from one directory to another subdirectory resulted in an
     endless loop and a RecursionError.  A fix was added to consume an
     iterator and create the list of the entries to be copied, avoiding
     the recursion for newly created directories.  Patch by Bruno P.
     Kinoshita.

   - bpo-38863(22): Improve ‘is_cgi()’ function in *note http.server:
     76, which enables processing the case that cgi directory is a child
     of another directory other than root.

   - bpo-37838(23): *note typing.get_type_hints(): 8c1. properly handles
     functions decorated with *note functools.wraps(): 115f.

   - bpo-38870(24): Expose *note ast.unparse(): ae4. as a function of
     the *note ast: 9. module that can be used to unparse an *note
     ast.AST: 4c4. object and produce a string with code that would
     produce an equivalent *note ast.AST: 4c4. object when parsed.
     Patch by Pablo Galindo and Batuhan Taskaya.

   - bpo-38859(25): AsyncMock now returns StopAsyncIteration on the
     exhaustion of a side_effects iterable.  Since PEP-479 its
     Impossible to raise a StopIteration exception from a coroutine.

   - bpo-38857(26): AsyncMock fix for return values that are awaitable
     types.  This also covers side_effect iterable values that happened
     to be awaitable, and wraps callables that return an awaitable type.
     Before these awaitables were being awaited instead of being
     returned as is.

   - bpo-38834(27): *note typing.TypedDict: 332. subclasses now track
     which keys are optional using the ‘__required_keys__’ and
     ‘__optional_keys__’ attributes, to enable runtime validation by
     downstream projects.  Patch by Zac Hatfield-Dodds.

   - bpo-38821(28): Fix unhandled exceptions in *note argparse: 7. when
     internationalizing error messages for arguments with ‘nargs’ set to
     special (non-integer) values.  Patch by Federico Bond.

   - bpo-38820(29): Make Python compatible with OpenSSL 3.0.0.  *note
     ssl.SSLSocket.getpeercert(): 11ba. no longer returns IPv6 addresses
     with a trailing new line.

   - bpo-38811(30): Fix an unhandled exception in *note pathlib: a8.
     when *note os.link(): 12f7. is missing.  Patch by Toke
     Høiland-Jørgensen.

   - bpo-38686(31): Added support for multiple ‘qop’ values in *note
     urllib.request.AbstractDigestAuthHandler: 1d53.

   - bpo-38712(32): Add the Linux-specific *note
     signal.pidfd_send_signal(): b27. function, which allows sending a
     signal to a process identified by a file descriptor rather than a
     pid.

   - bpo-38348(33): Add ‘-i’ and ‘--indent’ (indentation level), and
     ‘--no-type-comments’ (type comments) command line options to ast
     parsing tool.

   - bpo-37523(34): Change ‘zipfile.ZipExtFile’ to raise ‘ValueError’
     when trying to access the underlying file object after it has been
     closed.  This new behavior is consistent with how accessing closed
     files is handled in other parts of Python.

   - bpo-38045(35): Improve the performance of ‘enum._decompose()’ in
     *note enum: 5a.  Patch by hongweipeng.

   - bpo-36820(36): Break cycle generated when saving an exception in
     socket.py, codeop.py and dyld.py as they keep alive not only the
     exception but user objects through the ‘__traceback__’ attribute.
     Patch by Mario Corchero.

   - bpo-36406(37): Handle namespace packages in *note doctest: 3e.
     Patch by Karthikeyan Singaravelan.

   - bpo-34776(38): Fix dataclasses to support forward references in
     type annotations

   - bpo-20928(39): ElementTree supports recursive XInclude processing.
     Patch by Stefan Behnel.

   - bpo-29636(40): Add whitespace options for formatting JSON with the
     ‘json.tool’ CLI. The following mutually exclusive options are now
     supported: ‘--indent’ for setting the indent level in spaces;
     ‘--tab’ for indenting with tabs; ‘--no-indent’ for suppressing
     newlines; and ‘--compact’ for suppressing all whitespace.  The
     default behavior remains the same as ‘--indent=4’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39033

   (2) https://bugs.python.org/issue?@action=redirect&bpo=39022

   (3) https://bugs.python.org/issue?@action=redirect&bpo=39006

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38708

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38698

   (6) https://bugs.python.org/issue?@action=redirect&bpo=38994

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38979

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38978

   (9) https://bugs.python.org/issue?@action=redirect&bpo=38916

   (10) https://bugs.python.org/issue?@action=redirect&bpo=38986

   (11) https://bugs.python.org/issue?@action=redirect&bpo=38982

   (12) https://bugs.python.org/issue?@action=redirect&bpo=38529

   (13) https://bugs.python.org/issue?@action=redirect&bpo=27413

   (14) https://bugs.python.org/issue?@action=redirect&bpo=38634

   (15) https://bugs.python.org/issue?@action=redirect&bpo=33684

   (16) https://bugs.python.org/issue?@action=redirect&bpo=38698

   (17) https://bugs.python.org/issue?@action=redirect&bpo=38927

   (18) https://bugs.python.org/issue?@action=redirect&bpo=26730

   (19) https://bugs.python.org/issue?@action=redirect&bpo=38881

   (20) https://bugs.python.org/issue?@action=redirect&bpo=38876

   (21) https://bugs.python.org/issue?@action=redirect&bpo=38688

   (22) https://bugs.python.org/issue?@action=redirect&bpo=38863

   (23) https://bugs.python.org/issue?@action=redirect&bpo=37838

   (24) https://bugs.python.org/issue?@action=redirect&bpo=38870

   (25) https://bugs.python.org/issue?@action=redirect&bpo=38859

   (26) https://bugs.python.org/issue?@action=redirect&bpo=38857

   (27) https://bugs.python.org/issue?@action=redirect&bpo=38834

   (28) https://bugs.python.org/issue?@action=redirect&bpo=38821

   (29) https://bugs.python.org/issue?@action=redirect&bpo=38820

   (30) https://bugs.python.org/issue?@action=redirect&bpo=38811

   (31) https://bugs.python.org/issue?@action=redirect&bpo=38686

   (32) https://bugs.python.org/issue?@action=redirect&bpo=38712

   (33) https://bugs.python.org/issue?@action=redirect&bpo=38348

   (34) https://bugs.python.org/issue?@action=redirect&bpo=37523

   (35) https://bugs.python.org/issue?@action=redirect&bpo=38045

   (36) https://bugs.python.org/issue?@action=redirect&bpo=36820

   (37) https://bugs.python.org/issue?@action=redirect&bpo=36406

   (38) https://bugs.python.org/issue?@action=redirect&bpo=34776

   (39) https://bugs.python.org/issue?@action=redirect&bpo=20928

   (40) https://bugs.python.org/issue?@action=redirect&bpo=29636


File: python.info,  Node: Documentation<49>,  Next: Tests<48>,  Prev: Library<155>,  Up: Python 3 9 0 alpha 2

1.24.55.4 Documentation
.......................

   - bpo-38928(1): Correct when venv’s ‘upgrade_dependencies()’ and
     ‘--upgrade-deps’ are added.

   - bpo-38899(2): Update documentation to state that to activate
     virtual environments under fish one should use ‘source’, not ‘.’ as
     documented at
     ‘https://fishshell.com/docs/current/cmds/source.html’.

   - bpo-22377(3): Improves documentation of the values that *note
     datetime.datetime.strptime(): 1938. accepts for ‘%Z’.  Patch by
     Karl Dubost.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38928

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38899

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22377


File: python.info,  Node: Tests<48>,  Next: Build<56>,  Prev: Documentation<49>,  Up: Python 3 9 0 alpha 2

1.24.55.5 Tests
...............

   - bpo-38546(1): Fix test_ressources_gced_in_workers() of
     test_concurrent_futures: explicitly stop the manager to prevent
     leaking a child process running in the background after the test
     completes.

   - bpo-38546(2): Multiprocessing and concurrent.futures tests now stop
     the resource tracker process when tests complete.

   - bpo-38614(3): Replace hardcoded timeout constants in tests with new
     *note test.support: ea. constants: *note LOOPBACK_TIMEOUT: 1d84,
     *note INTERNET_TIMEOUT: 1d85, *note SHORT_TIMEOUT: 1c4b. and *note
     LONG_TIMEOUT: 1d86.  It becomes easier to adjust these four timeout
     constants for all tests at once, rather than having to adjust every
     single test file.

   - bpo-38547(4): Fix test_pty: if the process is the session leader,
     closing the master file descriptor raises a SIGHUP signal: simply
     ignore SIGHUP when running the tests.

   - bpo-38992(5): Fix a test for *note math.fsum(): 15db. that was
     failing due to constant folding.

   - bpo-38991(6): *note test.support: ea.: ‘run_python_until_end()’,
     ‘assert_python_ok()’ and ‘assert_python_failure()’ functions no
     longer strip whitespaces from stderr.  Remove
     ‘test.support.strip_python_stderr()’ function.

   - bpo-38965(7): Fix test_faulthandler on GCC 10.  Use the «volatile»
     keyword in ‘faulthandler._stack_overflow()’ to prevent tail call
     optimization on any compiler, rather than relying on compiler
     specific pragma.

   - bpo-38875(8): test_capi: trashcan tests now require the test «cpu»
     resource.

   - bpo-38841(9): Skip asyncio
     test_create_datagram_endpoint_existing_sock_unix on platforms
     lacking a functional bind() for named unix domain sockets.

   - bpo-38692(10): Skip the test_posix.test_pidfd_open() test if
     ‘os.pidfd_open()’ fails with a *note PermissionError: f40.  This
     situation can happen in a Linux sandbox using a syscall whitelist
     which doesn’t allow the ‘pidfd_open()’ syscall yet.

   - bpo-38839(11): Fix some unused functions in tests.  Patch by Adam
     Johnson.

   - bpo-38669(12): Raise *note TypeError: 198. when passing target as a
     string with *note unittest.mock.patch.object(): 18ee.

   - bpo-37957(13): test.regrtest now can receive a list of test
     patterns to ignore (using the -i/–ignore argument) or a file with a
     list of patterns to ignore (using the –ignore-file argument).
     Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38546

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38546

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38614

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38547

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38992

   (6) https://bugs.python.org/issue?@action=redirect&bpo=38991

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38965

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38875

   (9) https://bugs.python.org/issue?@action=redirect&bpo=38841

   (10) https://bugs.python.org/issue?@action=redirect&bpo=38692

   (11) https://bugs.python.org/issue?@action=redirect&bpo=38839

   (12) https://bugs.python.org/issue?@action=redirect&bpo=38669

   (13) https://bugs.python.org/issue?@action=redirect&bpo=37957


File: python.info,  Node: Build<56>,  Next: Windows<48>,  Prev: Tests<48>,  Up: Python 3 9 0 alpha 2

1.24.55.6 Build
...............

   - bpo-37404(1): *note asyncio: b. now raises *note TypeError: 198.
     when calling incompatible methods with an *note ssl.SSLSocket: ae9.
     socket.  Patch by Ido Michael.

   - bpo-36500(2): Added an optional «regen» project to the Visual
     Studio solution that will regenerate all grammar, tokens, and
     opcodes.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37404

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36500


File: python.info,  Node: Windows<48>,  Next: macOS<37>,  Prev: Build<56>,  Up: Python 3 9 0 alpha 2

1.24.55.7 Windows
.................

   - bpo-39007(1): Add auditing events to functions in *note winreg:
     11c.

   - bpo-33125(2): Add support for building and releasing Windows ARM64
     packages.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=39007

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33125


File: python.info,  Node: macOS<37>,  Next: IDLE<31>,  Prev: Windows<48>,  Up: Python 3 9 0 alpha 2

1.24.55.8 macOS
...............

   - bpo-37931(1): Fixed a crash on OSX dynamic builds that occurred
     when re-initializing the posix module after a Py_Finalize if the
     environment had changed since the previous ‘import posix’.  Patch
     by Benoît Hudson.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37931


File: python.info,  Node: IDLE<31>,  Next: C API<51>,  Prev: macOS<37>,  Up: Python 3 9 0 alpha 2

1.24.55.9 IDLE
..............

   - bpo-38944(1): Escape key now closes IDLE completion windows.  Patch
     by Johnny Najera.

   - bpo-38943(2): Fix IDLE autocomplete windows not always appearing on
     some systems.  Patch by Johnny Najera.

   - bpo-38862(3): “Strip Trailing Whitespace” on the Format menu
     removes extra newlines at the end of non-shell files.

   - bpo-38636(4): Fix IDLE Format menu tab toggle and file indent
     width.  These functions (default shortcuts Alt-T and Alt-U) were
     mistakenly disabled in 3.7.5 and 3.8.0.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38944

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38943

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38862

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38636


File: python.info,  Node: C API<51>,  Prev: IDLE<31>,  Up: Python 3 9 0 alpha 2

1.24.55.10 C API
................

   - bpo-38896(1): Remove ‘PyUnicode_ClearFreeList()’ function: the
     Unicode free list has been removed in Python 3.3.

   - bpo-37340(2): Remove ‘PyMethod_ClearFreeList()’ and
     ‘PyCFunction_ClearFreeList()’ functions: the free lists of bound
     method objects have been removed.

   - bpo-38835(3): Exclude ‘PyFPE_START_PROTECT()’ and
     ‘PyFPE_END_PROTECT()’ macros of ‘pyfpe.h’ from ‘Py_LIMITED_API’
     (stable API).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38896

   (2) https://bugs.python.org/issue?@action=redirect&bpo=37340

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38835


File: python.info,  Node: Python 3 9 0 alpha 1,  Next: Python 3 8 0 beta 1,  Prev: Python 3 9 0 alpha 2,  Up: Changelog

1.24.56 Python 3.9.0 alpha 1
----------------------------

'Release date: 2019-11-19'

* Menu:

* Security: Security<42>.
* Core and Builtins: Core and Builtins<153>.
* Library: Library<156>.
* Documentation: Documentation<50>.
* Tests: Tests<49>.
* Build: Build<57>.
* Windows: Windows<49>.
* macOS: macOS<38>.
* IDLE: IDLE<32>.
* Tools/Demos: Tools/Demos<33>.
* C API: C API<52>.


File: python.info,  Node: Security<42>,  Next: Core and Builtins<153>,  Up: Python 3 9 0 alpha 1

1.24.56.1 Security
..................

   - bpo-38722(1): *note runpy: c3. now uses *note io.open_code(): 1a80.
     to open code files.  Patch by Jason Killen.

   - bpo-38622(2): Add additional audit events for the *note ctypes: 2e.
     module.

   - bpo-38418(3): Fixes audit event for *note os.system(): 1664. to be
     named ‘os.system’.

   - bpo-38243(4): Escape the server title of *note
     xmlrpc.server.DocXMLRPCServer: 1d8e. when rendering the document
     page as HTML. (Contributed by Donghee Na in bpo-38243(5).)

   - bpo-38174(6): Update vendorized expat library version to 2.2.8,
     which resolves CVE 2019-15903(7).

   - bpo-37764(8): Fixes email._header_value_parser.get_unstructured
     going into an infinite loop for a specific case in which the email
     header does not have trailing whitespace, and the case in which it
     contains an invalid encoded word.  Patch by Ashwin Ramaswami.

   - bpo-37461(9): Fix an infinite loop when parsing specially crafted
     email headers.  Patch by Abhilash Raj.

   - bpo-37363(10): Adds audit events for the range of supported run
     commands (see *note Command line and environment: 1d8f.).

   - bpo-37463(11): ssl.match_hostname() no longer accepts IPv4
     addresses with additional text after the address and only
     quad-dotted notation without trailing whitespaces.  Some
     inet_aton() implementations ignore whitespace and all data after
     whitespace, e.g.  “127.0.0.1 whatever”.

   - bpo-37363(12): Adds audit events for *note ensurepip: 59, *note
     ftplib: 62, *note glob: 68, *note imaplib: 78, ‘nntplib’, *note
     pdb: aa, *note poplib: b1, *note shutil: ca, *note smtplib: cf,
     *note sqlite3: d4, *note subprocess: dc, ‘telnetlib’, *note
     tempfile: e6. and *note webbrowser: 11b, as well as *note
     os.listdir(): 1302, *note os.scandir(): c56. and *note
     breakpoint(): 271.

   - bpo-37364(13): *note io.open_code(): 1a80. is now used when reading
     ‘.pth’ files.

   - bpo-34631(14): Updated OpenSSL to 1.1.1c in Windows installer

   - bpo-34155(15): Fix parsing of invalid email addresses with more
     than one ‘@’ (e.g.  a@b@c.com.)  to not return the part before 2nd
     ‘@’ as valid email address.  Patch by maxking & jpic.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38722

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38622

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38418

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38243

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38243

   (6) https://bugs.python.org/issue?@action=redirect&bpo=38174

   (7) https://www.cve.org/CVERecord?id=CVE-2019-15903

   (8) https://bugs.python.org/issue?@action=redirect&bpo=37764

   (9) https://bugs.python.org/issue?@action=redirect&bpo=37461

   (10) https://bugs.python.org/issue?@action=redirect&bpo=37363

   (11) https://bugs.python.org/issue?@action=redirect&bpo=37463

   (12) https://bugs.python.org/issue?@action=redirect&bpo=37363

   (13) https://bugs.python.org/issue?@action=redirect&bpo=37364

   (14) https://bugs.python.org/issue?@action=redirect&bpo=34631

   (15) https://bugs.python.org/issue?@action=redirect&bpo=34155


File: python.info,  Node: Core and Builtins<153>,  Next: Library<156>,  Prev: Security<42>,  Up: Python 3 9 0 alpha 1

1.24.56.2 Core and Builtins
...........................

   - bpo-38631(1): Replace ‘Py_FatalError()’ call with a regular *note
     RuntimeError: 244. exception in ‘float.__getformat__()’.

   - bpo-38639(2): Optimized *note math.floor(): 15c5, *note
     math.ceil(): 15c6. and *note math.trunc(): 15c7. for floats.

   - bpo-38640(3): Fixed a bug in the compiler that was causing to raise
     in the presence of break statements and continue statements inside
     always false while loops.  Patch by Pablo Galindo.

   - bpo-38613(4): Optimized some set operations (e.g.  ‘|’, ‘^’, and
     ‘-’) of ‘dict_keys’.  ‘d.keys() | other’ was slower than ‘set(d) |
     other’ but they are almost same performance for now.

   - bpo-28029(5): ‘"".replace("", s, n)’ now returns ‘s’ instead of an
     empty string for all non-zero ‘n’.  There are similar changes for
     *note bytes: 192. and *note bytearray: 344. objects.

   - bpo-38535(6): Fixed line numbers and column offsets for AST nodes
     for calls without arguments in decorators.

   - bpo-38525(7): Fix a segmentation fault when using reverse iterators
     of empty ‘dict’ objects.  Patch by Donghee Na and Inada Naoki.

   - bpo-38465(8): *note bytearray: 344, *note array: 4bf. and *note
     mmap: 51a. objects allow now to export more than ‘2**31’ buffers at
     a time.

   - bpo-38469(9): Fixed a bug where the scope of named expressions was
     not being resolved correctly in the presence of the 'global'
     keyword.  Patch by Pablo Galindo.

   - bpo-38437(10): Activate the ‘GC_DEBUG’ macro for debug builds of
     the interpreter (when ‘Py_DEBUG’ is set).  Patch by Pablo Galindo.

   - bpo-38379(11): When the garbage collector makes a collection in
     which some objects resurrect (they are reachable from outside the
     isolated cycles after the finalizers have been executed), do not
     block the collection of all objects that are still unreachable.
     Patch by Pablo Galindo and Tim Peters.

   - bpo-38379(12): When cyclic garbage collection (gc) runs finalizers
     that resurrect unreachable objects, the current gc run ends,
     without collecting any cyclic trash.  However, the statistics
     reported by ‘collect()’ and ‘get_stats()’ claimed that all cyclic
     trash found was collected, and that the resurrected objects were
     collected.  Changed the stats to report that none were collected.

   - bpo-38392(13): In debug mode, *note PyObject_GC_Track(): 170b. now
     calls ‘tp_traverse()’ of the object type to ensure that the object
     is valid: test that objects visited by ‘tp_traverse()’ are valid.

   - bpo-38210(14): Remove unnecessary intersection and update set
     operation in dictview with empty set.  (Contributed by Donghee Na
     in bpo-38210(15).)

   - bpo-38402(16): Check the error from the system’s underlying ‘crypt’
     or ‘crypt_r’.

   - bpo-37474(17): On FreeBSD, Python no longer calls
     ‘fedisableexcept()’ at startup to control the floating-point
     control mode.  The call became useless since FreeBSD 6: it became
     the default mode.

   - bpo-38006(18): Fix a bug due to the interaction of weakrefs and the
     cyclic garbage collector.  We must clear any weakrefs in garbage in
     order to prevent their callbacks from executing and causing a
     crash.

   - bpo-38317(19): Fix warnings options priority:
     ‘PyConfig.warnoptions’ has the highest priority, as stated in the
     PEP 587(20).

   - bpo-38310(21): Predict ‘BUILD_MAP_UNPACK_WITH_CALL’ ->
     ‘CALL_FUNCTION_EX’ opcode pairs in the main interpreter loop.
     Patch by Brandt Bucher.

   - bpo-36871(22): Improve error handling for the assert_has_calls and
     assert_has_awaits methods of mocks.  Fixed a bug where any errors
     encountered while binding the expected calls to the mock’s spec
     were silently swallowed, leading to misleading error output.

   - bpo-11410(23): Better control over symbol visibility is provided
     through use of the visibility attributes available in gcc >= 4.0,
     provided in a uniform way across POSIX and Windows.  The POSIX
     build files have been updated to compile with -fvisibility=hidden,
     minimising exported symbols.

   - bpo-38219(24): Optimized the *note dict: 183. constructor and the
     *note update(): 166c. method for the case when the argument is a
     dict.

   - bpo-38236(25): Python now dumps path configuration if it fails to
     import the Python codecs of the filesystem and stdio encodings.

   - bpo-38013(26): Allow to call ‘async_generator_athrow().throw(...)’
     even for non-started async generator helper.  It fixes annoying
     warning at the end of *note asyncio.run(): 2f3. call.

   - bpo-38124(27): Fix an off-by-one error in PyState_AddModule that
     could cause out-of-bounds memory access.

   - bpo-38116(28): The select module is now PEP-384 compliant and no
     longer has static state

   - bpo-38113(29): ast module updated to PEP-384 and all statics
     removed

   - bpo-38076(30): The struct module is now PEP-384 compatible

   - bpo-38075(31): The random module is now PEP-384 compatible

   - bpo-38074(32): zlib module made PEP-384 compatible

   - bpo-38073(33): Make pwd extension module PEP-384 compatible

   - bpo-38072(34): grp module made PEP-384 compatible

   - bpo-38069(35): Make _posixsubprocess PEP-384 compatible

   - bpo-38071(36): Make termios extension module PEP-384 compatible

   - bpo-38005(37): Fixed comparing and creating of InterpreterID and
     ChannelID.

   - bpo-36946(38): Fix possible signed integer overflow when handling
     slices.  Patch by hongweipeng.

   - bpo-37994(39): Fixed silencing arbitrary errors if an attribute
     lookup fails in several sites.  Only AttributeError should be
     silenced.

   - bpo-8425(40): Optimize set difference_update for the case when the
     other set is much larger than the base set.  (Suggested by Evgeny
     Kapun with code contributed by Michele Orrù).

   - bpo-37966(41): The implementation of *note is_normalized(): c3e.
     has been greatly sped up on strings that aren’t normalized, by
     implementing the full normalization-quick-check algorithm from the
     Unicode standard.

   - bpo-37947(42): Adjust correctly the recursion level in the symtable
     generation for named expressions.  Patch by Pablo Galindo.

   - bpo-37812(43): The ‘CHECK_SMALL_INT’ macro used inside
     ‘Object/longobject.c’ has been replaced with an explicit ‘return’
     at each call site.

   - bpo-37751(44): Fix *note codecs.lookup(): b5e. to normalize the
     encoding name the same way than *note
     encodings.normalize_encoding(): 9ff, except that *note
     codecs.lookup(): b5e. also converts the name to lower case.

   - bpo-37830(45): Fixed compilation of *note break: 17f. and *note
     continue: 180. in the *note finally: 1b0. block when the
     corresponding *note try: 8f9. block contains *note return: 1af.
     with a non-constant value.

   - bpo-20490(46): Improve import error message for partially
     initialized module on circular ‘from’ imports - by Anthony Sottile.

   - bpo-37840(47): Fix handling of negative indices in *note sq_item:
     1cdd. of *note bytearray: 344.  Patch by Sergey Fedoseev.

   - bpo-37802(48): Slightly improve performance of *note
     PyLong_FromUnsignedLong(): 18a5, *note
     PyLong_FromUnsignedLongLong(): 18a6. and *note PyLong_FromSize_t():
     18a7.  Patch by Sergey Fedoseev.

   - bpo-37409(49): Ensure explicit relative imports from interactive
     sessions and scripts (having no parent package) always raise
     ImportError, rather than treating the current module as the
     package.  Patch by Ben Lewis.

   - bpo-32912(50): Reverted bpo-32912(51): emitting *note
     SyntaxWarning: 1ae. instead of *note DeprecationWarning: 1a3. for
     invalid escape sequences in string and bytes literals.

   - bpo-37757(52): PEP 572(53): As described in the PEP, assignment
     expressions now raise *note SyntaxError: 18e. when their
     interaction with comprehension scoping results in an ambiguous
     target scope.

     The ‘TargetScopeError’ subclass originally proposed by the PEP has
     been removed in favour of just raising regular syntax errors for
     the disallowed cases.

   - bpo-36279(54): Fix potential use of uninitialized memory in *note
     os.wait3(): f98.

   - bpo-36311(55): Decoding bytes objects larger than 2GiB is faster
     and no longer fails when a multibyte characters spans a chunk
     boundary.

   - bpo-34880(56): The *note assert: b62. statement now works properly
     if the *note AssertionError: 8b9. exception is being shadowed.
     Patch by Zackery Spytz.

   - bpo-37340(57): Removed object cache (‘free_list’) for bound method
     objects.  Temporary bound method objects are less used than before
     thanks to the ‘LOAD_METHOD’ opcode and the
     ‘_PyObject_VectorcallMethod’ C API.

   - bpo-37648(58): Fixed minor inconsistency in ‘list.__contains__()’,
     ‘tuple.__contains__()’ and a few other places.  The collection’s
     item is now always at the left and the needle is on the right of
     ‘==’.

   - bpo-37444(59): Update differing exception between
     ‘builtins.__import__()’ and *note importlib.__import__(): 126f.

   - bpo-37619(60): When adding a wrapper descriptor from one class to a
     different class (for example, setting ‘__add__ = str.__add__’ on an
     ‘int’ subclass), an exception is correctly raised when the operator
     is called.

   - bpo-37593(61): Swap the positions of the 'posonlyargs' and 'args'
     parameters in the constructor of ‘ast.parameters’ nodes.

   - bpo-37543(62): Optimized pymalloc for non PGO build.

   - bpo-37537(63): Compute allocated pymalloc blocks inside
     _Py_GetAllocatedBlocks().  This slows down _Py_GetAllocatedBlocks()
     but gives a small speedup to _PyObject_Malloc() and
     _PyObject_Free().

   - bpo-37467(64): Fix *note sys.excepthook(): a0e. and
     ‘PyErr_Display()’ if a filename is a bytes string.  For example,
     for a SyntaxError exception where the filename attribute is a bytes
     string.

   - bpo-37433(65): Fix ‘SyntaxError’ indicator printing too many spaces
     for multi-line strings - by Anthony Sottile.

   - bpo-37417(66): *note bytearray.extend(): 1779. now correctly
     handles errors that arise during iteration.  Patch by Brandt
     Bucher.

   - bpo-37414(67): The undocumented ‘sys.callstats()’ function has been
     removed.  Since Python 3.7, it was deprecated and always returned
     ‘None’.  It required a special build option ‘CALL_PROFILE’ which
     was already removed in Python 3.7.

   - bpo-37392(68): Remove ‘sys.getcheckinterval()’ and
     ‘sys.setcheckinterval()’ functions.  They were deprecated since
     Python 3.2.  Use *note sys.getswitchinterval(): b45. and *note
     sys.setswitchinterval(): b46. instead.  Remove also
     ‘check_interval’ field of the ‘PyInterpreterState’ structure.

   - bpo-37388(69): In development mode and in debug build, 'encoding'
     and 'errors' arguments are now checked on string encoding and
     decoding operations.  Examples: *note open(): 316, *note
     str.encode(): ad4. and *note bytes.decode(): ad5.

     By default, for best performances, the 'errors' argument is only
     checked at the first encoding/decoding error, and the 'encoding'
     argument is sometimes ignored for empty strings.

   - bpo-37348(70): Optimized decoding short ASCII string with UTF-8 and
     ascii codecs.  ‘b"foo".decode()’ is about 15% faster.  Patch by
     Inada Naoki.

   - bpo-24214(71): Improved support of the surrogatepass error handler
     in the UTF-8 and UTF-16 incremental decoders.

   - bpo-37330(72): *note open(): 316, *note io.open(): 741, *note
     codecs.open(): 315. and *note fileinput.FileInput: 941. no longer
     accept ‘'U'’ («universal newline») in the file mode.  This flag was
     deprecated since Python 3.3.

   - bpo-35224(73): Reverse evaluation order of key: value in dict
     comprehensions as proposed in PEP 572.  I.e.  in ‘{k: v for ...}’,
     ‘k’ will be evaluated before ‘v’.

   - bpo-37316(74): Fix the *note PySys_Audit(): 613. call in *note
     mmap.mmap: 51a.

   - bpo-37300(75): Remove an unnecessary Py_XINCREF in classobject.c.

   - bpo-37269(76): Fix a bug in the peephole optimizer that was not
     treating correctly constant conditions with binary operators.
     Patch by Pablo Galindo.

   - bpo-20443(77): Python now gets the absolute path of the script
     filename specified on the command line (ex: «python3 script.py»):
     the __file__ attribute of the __main__ module and sys.path[0]
     become an absolute path, rather than a relative path.

   - bpo-37257(78): Python’s small object allocator (‘obmalloc.c’) now
     allows (no more than) one empty arena to remain available for
     immediate reuse, without returning it to the OS. This prevents
     thrashing in simple loops where an arena could be created and
     destroyed anew on each iteration.

   - bpo-37231(79): The dispatching of type slots to special methods
     (for example calling ‘__mul__’ when doing ‘x * y’) has been made
     faster.

   - bpo-36974(80): Implemented separate vectorcall functions for every
     calling convention of builtin functions and methods.  This improves
     performance for calls.

   - bpo-37213(81): Handle correctly negative line offsets in the
     peephole optimizer.  Patch by Pablo Galindo.

   - bpo-37219(82): Remove erroneous optimization for empty set
     differences.

   - bpo-15913(83): Implement *note PyBuffer_SizeFromFormat(): 95f.
     function (previously documented but not implemented): call *note
     struct.calcsize(): 1d91.  Patch by Joannah Nanjekye.

   - bpo-36922(84): Slot functions optimize any callable with
     ‘Py_TPFLAGS_METHOD_DESCRIPTOR’ instead of only instances of
     ‘function’.

   - bpo-36974(85): The slot ‘tp_vectorcall_offset’ is inherited
     unconditionally to support ‘super().__call__()’ when the base class
     uses vectorcall.

   - bpo-37160(86): *note threading.get_native_id(): c34. now also
     supports NetBSD.

   - bpo-37077(87): Add *note threading.get_native_id(): c34. support
     for AIX. Patch by M. Felt

   - bpo-36781(88): *note sum(): 696. has been optimized for boolean
     values.

   - bpo-34556(89): Add ‘--upgrade-deps’ to venv module.  Patch by
     Cooper Ry Lees

   - bpo-20523(90): ‘pdb.Pdb’ supports ~/.pdbrc in Windows 7.  Patch by
     Tim Hopper and Dan Lidral-Porter.

   - bpo-35551(91): Updated encodings: - Removed the «tis260» encoding,
     which was an alias for the nonexistent «tactis» codec.  - Added
     «mac_centeuro» as an alias for the mac_latin2 encoding.

   - bpo-19072(92): The *note classmethod: 48f. decorator can now wrap
     other descriptors such as property objects.  Adapted from a patch
     written by Graham Dumpleton.

   - bpo-27575(93): Improve speed of dictview intersection by directly
     using set intersection logic.  Patch by David Su.

   - bpo-30773(94): Prohibit parallel running of aclose() / asend() /
     athrow().  Fix ag_running to reflect the actual running status of
     the AG.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38631

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38639

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38640

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38613

   (5) https://bugs.python.org/issue?@action=redirect&bpo=28029

   (6) https://bugs.python.org/issue?@action=redirect&bpo=38535

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38525

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38465

   (9) https://bugs.python.org/issue?@action=redirect&bpo=38469

   (10) https://bugs.python.org/issue?@action=redirect&bpo=38437

   (11) https://bugs.python.org/issue?@action=redirect&bpo=38379

   (12) https://bugs.python.org/issue?@action=redirect&bpo=38379

   (13) https://bugs.python.org/issue?@action=redirect&bpo=38392

   (14) https://bugs.python.org/issue?@action=redirect&bpo=38210

   (15) https://bugs.python.org/issue?@action=redirect&bpo=38210

   (16) https://bugs.python.org/issue?@action=redirect&bpo=38402

   (17) https://bugs.python.org/issue?@action=redirect&bpo=37474

   (18) https://bugs.python.org/issue?@action=redirect&bpo=38006

   (19) https://bugs.python.org/issue?@action=redirect&bpo=38317

   (20) https://peps.python.org/pep-0587/

   (21) https://bugs.python.org/issue?@action=redirect&bpo=38310

   (22) https://bugs.python.org/issue?@action=redirect&bpo=36871

   (23) https://bugs.python.org/issue?@action=redirect&bpo=11410

   (24) https://bugs.python.org/issue?@action=redirect&bpo=38219

   (25) https://bugs.python.org/issue?@action=redirect&bpo=38236

   (26) https://bugs.python.org/issue?@action=redirect&bpo=38013

   (27) https://bugs.python.org/issue?@action=redirect&bpo=38124

   (28) https://bugs.python.org/issue?@action=redirect&bpo=38116

   (29) https://bugs.python.org/issue?@action=redirect&bpo=38113

   (30) https://bugs.python.org/issue?@action=redirect&bpo=38076

   (31) https://bugs.python.org/issue?@action=redirect&bpo=38075

   (32) https://bugs.python.org/issue?@action=redirect&bpo=38074

   (33) https://bugs.python.org/issue?@action=redirect&bpo=38073

   (34) https://bugs.python.org/issue?@action=redirect&bpo=38072

   (35) https://bugs.python.org/issue?@action=redirect&bpo=38069

   (36) https://bugs.python.org/issue?@action=redirect&bpo=38071

   (37) https://bugs.python.org/issue?@action=redirect&bpo=38005

   (38) https://bugs.python.org/issue?@action=redirect&bpo=36946

   (39) https://bugs.python.org/issue?@action=redirect&bpo=37994

   (40) https://bugs.python.org/issue?@action=redirect&bpo=8425

   (41) https://bugs.python.org/issue?@action=redirect&bpo=37966

   (42) https://bugs.python.org/issue?@action=redirect&bpo=37947

   (43) https://bugs.python.org/issue?@action=redirect&bpo=37812

   (44) https://bugs.python.org/issue?@action=redirect&bpo=37751

   (45) https://bugs.python.org/issue?@action=redirect&bpo=37830

   (46) https://bugs.python.org/issue?@action=redirect&bpo=20490

   (47) https://bugs.python.org/issue?@action=redirect&bpo=37840

   (48) https://bugs.python.org/issue?@action=redirect&bpo=37802

   (49) https://bugs.python.org/issue?@action=redirect&bpo=37409

   (50) https://bugs.python.org/issue?@action=redirect&bpo=32912

   (51) https://bugs.python.org/issue?@action=redirect&bpo=32912

   (52) https://bugs.python.org/issue?@action=redirect&bpo=37757

   (53) https://peps.python.org/pep-0572/

   (54) https://bugs.python.org/issue?@action=redirect&bpo=36279

   (55) https://bugs.python.org/issue?@action=redirect&bpo=36311

   (56) https://bugs.python.org/issue?@action=redirect&bpo=34880

   (57) https://bugs.python.org/issue?@action=redirect&bpo=37340

   (58) https://bugs.python.org/issue?@action=redirect&bpo=37648

   (59) https://bugs.python.org/issue?@action=redirect&bpo=37444

   (60) https://bugs.python.org/issue?@action=redirect&bpo=37619

   (61) https://bugs.python.org/issue?@action=redirect&bpo=37593

   (62) https://bugs.python.org/issue?@action=redirect&bpo=37543

   (63) https://bugs.python.org/issue?@action=redirect&bpo=37537

   (64) https://bugs.python.org/issue?@action=redirect&bpo=37467

   (65) https://bugs.python.org/issue?@action=redirect&bpo=37433

   (66) https://bugs.python.org/issue?@action=redirect&bpo=37417

   (67) https://bugs.python.org/issue?@action=redirect&bpo=37414

   (68) https://bugs.python.org/issue?@action=redirect&bpo=37392

   (69) https://bugs.python.org/issue?@action=redirect&bpo=37388

   (70) https://bugs.python.org/issue?@action=redirect&bpo=37348

   (71) https://bugs.python.org/issue?@action=redirect&bpo=24214

   (72) https://bugs.python.org/issue?@action=redirect&bpo=37330

   (73) https://bugs.python.org/issue?@action=redirect&bpo=35224

   (74) https://bugs.python.org/issue?@action=redirect&bpo=37316

   (75) https://bugs.python.org/issue?@action=redirect&bpo=37300

   (76) https://bugs.python.org/issue?@action=redirect&bpo=37269

   (77) https://bugs.python.org/issue?@action=redirect&bpo=20443

   (78) https://bugs.python.org/issue?@action=redirect&bpo=37257

   (79) https://bugs.python.org/issue?@action=redirect&bpo=37231

   (80) https://bugs.python.org/issue?@action=redirect&bpo=36974

   (81) https://bugs.python.org/issue?@action=redirect&bpo=37213

   (82) https://bugs.python.org/issue?@action=redirect&bpo=37219

   (83) https://bugs.python.org/issue?@action=redirect&bpo=15913

   (84) https://bugs.python.org/issue?@action=redirect&bpo=36922

   (85) https://bugs.python.org/issue?@action=redirect&bpo=36974

   (86) https://bugs.python.org/issue?@action=redirect&bpo=37160

   (87) https://bugs.python.org/issue?@action=redirect&bpo=37077

   (88) https://bugs.python.org/issue?@action=redirect&bpo=36781

   (89) https://bugs.python.org/issue?@action=redirect&bpo=34556

   (90) https://bugs.python.org/issue?@action=redirect&bpo=20523

   (91) https://bugs.python.org/issue?@action=redirect&bpo=35551

   (92) https://bugs.python.org/issue?@action=redirect&bpo=19072

   (93) https://bugs.python.org/issue?@action=redirect&bpo=27575

   (94) https://bugs.python.org/issue?@action=redirect&bpo=30773


File: python.info,  Node: Library<156>,  Next: Documentation<50>,  Prev: Core and Builtins<153>,  Up: Python 3 9 0 alpha 1

1.24.56.3 Library
.................

   - bpo-36589(1): The *note curses.update_lines_cols(): fed. function
     now returns ‘None’ instead of ‘1’ on success.

   - bpo-38807(2): Update *note TypeError: 198. messages for *note
     os.path.join(): 1991. to include *note os.PathLike: e4d. objects as
     acceptable input types.

   - bpo-38724(3): Add a repr for ‘subprocess.Popen’ objects.  Patch by
     Andrey Doroschenko.

   - bpo-38786(4): pydoc now recognizes and parses HTTPS URLs.  Patch by
     python273.

   - bpo-38785(5): Prevent asyncio from crashing if parent ‘__init__’ is
     not called from a constructor of object derived from
     ‘asyncio.Future’.

   - bpo-38723(6): *note pdb: aa. now uses *note io.open_code(): 1a80.
     to trigger auditing events.

   - bpo-27805(7): Allow opening pipes and other non-seekable files in
     append mode with *note open(): 316.

   - bpo-38438(8): Simplify the *note argparse: 7. usage message for
     ‘nargs="*"’.

   - bpo-38761(9): WeakSet is now registered as a
     collections.abc.MutableSet.

   - bpo-38716(10): logging: change RotatingHandler namer and rotator to
     class-level attributes.  This stops __init__ from setting them to
     None in the case where a subclass defines them with eponymous
     methods.

   - bpo-38713(11): Add *note os.P_PIDFD: b18. constant, which may be
     passed to *note os.waitid(): f9b. to wait on a Linux process file
     descriptor.

   - bpo-38692(12): Add ‘asyncio.PidfdChildWatcher’, a Linux-specific
     child watcher implementation that polls process file descriptors.

   - bpo-38692(13): Expose the Linux ‘pidfd_open’ syscall as *note
     os.pidfd_open(): 6a5.

   - bpo-38602(14): Added constants ‘F_OFD_GETLK’, ‘F_OFD_SETLK’ and
     ‘F_OFD_SETLKW’ to the *note fcntl: 5d. module.  Patch by Donghee
     Na.

   - bpo-38334(15): Fixed seeking backward on an encrypted
     ‘zipfile.ZipExtFile’.

   - bpo-38312(16): Add *note curses.get_escdelay(): aee, *note
     curses.set_escdelay(): aef, *note curses.get_tabsize(): af0, and
     *note curses.set_tabsize(): af1. functions - by Anthony Sottile.

   - bpo-38586(17): Now *note fileConfig(): d4a. correctly sets the
     .name of handlers loaded.

   - bpo-38565(18): Add new cache_parameters() method for
     functools.lru_cache() to better support pickling.

   - bpo-34679(19): asynci.ProactorEventLoop.close() now only calls
     signal.set_wakeup_fd() in the main thread.

   - bpo-31202(20): The case the result of ‘pathlib.WindowsPath.glob()’
     matches now the case of the pattern for literal parts.

   - bpo-36321(21): Remove misspelled attribute.  The 3.8 changelog
     noted that this would be removed in 3.9.

   - bpo-38521(22): Fixed erroneous equality comparison in
     statistics.NormalDist().

   - bpo-38493(23): Added *note CLD_KILLED: b16. and *note CLD_STOPPED:
     b17. for ‘si_code’.  Patch by Donghee Na.

   - bpo-38478(24): Fixed a bug in ‘inspect.signature.bind()’ that was
     causing it to fail when handling a keyword argument with same name
     as positional-only parameter.  Patch by Pablo Galindo.

   - bpo-33604(25): Fixed ‘hmac.new’ and ‘hmac.HMAC’ to raise TypeError
     instead of ValueError when the digestmod parameter, now required in
     3.8, is omitted.  Also clarified the hmac module documentation and
     docstrings.

   - bpo-38378(26): Parameters 'out' and 'in' of *note os.sendfile():
     d07. was renamed to 'out_fd' and 'in_fd'.

   - bpo-38417(27): Added support for setting the umask in the child
     process to the subprocess module on POSIX systems.

   - bpo-38449(28): Revert PR 15522, which introduces a regression in
     *note mimetypes.guess_type(): 518. due to improper handling of
     filenames as urls.

   - bpo-38431(29): Fix ‘__repr__’ method for *note dataclasses.InitVar:
     1b9c. to support typing objects, patch by Samuel Colvin.

   - bpo-38109(30): Add missing *note stat.S_IFDOOR: 11bd, *note
     stat.S_IFPORT: 11be, *note stat.S_IFWHT: 11bf, *note
     stat.S_ISDOOR(): 1d93, *note stat.S_ISPORT(): 1d94, and *note
     stat.S_ISWHT(): 1d95. values to the Python implementation of *note
     stat: d6.

   - bpo-38422(31): Clarify docstrings of pathlib suffix(es)

   - bpo-38405(32): Nested subclasses of *note typing.NamedTuple: 331.
     are now pickleable.

   - bpo-38332(33): Prevent *note KeyError: 5e7. thrown by
     ‘_encoded_words.decode()’ when given an encoded-word with invalid
     content-type encoding from propagating all the way to
     ‘email.message.get()’.

   - bpo-38371(34): Deprecated the ‘split()’ method in
     ‘_tkinter.TkappType’ in favour of the ‘splitlist()’ method which
     has more consistent and predictable behavior.

   - bpo-38341(35): Add *note smtplib.SMTPNotSupportedError: 1d96. to
     the *note smtplib: cf. exported names.

   - bpo-38319(36): sendfile() used in socket and shutil modules was
     raising OverflowError for files >= 2GiB on 32-bit architectures.
     (patch by Giampaolo Rodola)

   - bpo-38242(37): Revert the new asyncio Streams API

   - bpo-13153(38): OS native encoding is now used for converting
     between Python strings and Tcl objects.  This allows to display,
     copy and paste to clipboard emoji and other non-BMP characters.
     Converting strings from Tcl to Python and back now never fails
     (except MemoryError).

   - bpo-38019(39): Correctly handle pause/resume reading of closed
     asyncio unix pipe.

   - bpo-38163(40): Child mocks will now detect their type as either
     synchronous or asynchronous, asynchronous child mocks will be
     AsyncMocks and synchronous child mocks will be either MagicMock or
     Mock (depending on their parent type).

   - bpo-38161(41): Removes _AwaitEvent from AsyncMock.

   - bpo-38216(42): Allow the rare code that wants to send invalid http
     requests from the ‘http.client’ library a way to do so.  The fixes
     for bpo-30458(43) led to breakage for some projects that were
     relying on this ability to test their own behavior in the face of
     bad requests.

   - bpo-28286(44): Deprecate opening *note GzipFile: 65c. for writing
     implicitly.  Always specify the 'mode' argument for writing.

   - bpo-38108(45): Any synchronous magic methods on an AsyncMock now
     return a MagicMock.  Any asynchronous magic methods on a MagicMock
     now return an AsyncMock.

   - bpo-38265(46): Update the 'length' parameter of *note os.pread():
     d58. to accept *note Py_ssize_t: c57. instead of int.

   - bpo-38112(47): *note compileall: 21. has a higher default recursion
     limit and new command-line arguments for path manipulation,
     symlinks handling, and multiple optimization levels.

   - bpo-38248(48): asyncio: Fix inconsistent immediate Task
     cancellation

   - bpo-38237(49): The arguments for the builtin pow function are more
     descriptive.  They can now also be passed in as keywords.

   - bpo-34002(50): Improve efficiency in parts of email package by
     changing while-pop to a for loop, using isdisjoint instead of set
     intersections.

   - bpo-38191(51): Constructors of *note NamedTuple: 331. and *note
     TypedDict: 332. types now accept arbitrary keyword argument names,
     including «cls», «self», «typename», «_typename», «fields» and
     «_fields».

   - bpo-38155(52): Add ‘__all__’ to *note datetime: 34.  Patch by Tahia
     Khan.

   - bpo-38185(53): Fixed case-insensitive string comparison in *note
     sqlite3.Row: 1073. indexing.

   - bpo-38136(54): Changes AsyncMock call count and await count to be
     two different counters.  Now await count only counts when a
     coroutine has been awaited, not when it has been called, and
     vice-versa.  Update the documentation around this.

   - bpo-37828(55): Fix default mock name in *note
     unittest.mock.Mock.assert_called(): ef6. exceptions.  Patch by
     Abraham Toriz Cruz.

   - bpo-38175(56): Fix a memory leak in comparison of *note
     sqlite3.Row: 1073. objects.

   - bpo-33936(57): _hashlib no longer calls obsolete OpenSSL
     initialization function with OpenSSL 1.1.0+.

   - bpo-34706(58): Preserve subclassing in
     inspect.Signature.from_callable.

   - bpo-38153(59): Names of hashing algorithms from OpenSSL are now
     normalized to follow Python’s naming conventions.  For example
     OpenSSL uses sha3-512 instead of sha3_512 or blake2b512 instead of
     blake2b.

   - bpo-38115(60): Fix a bug in dis.findlinestarts() where it would
     return invalid bytecode offsets.  Document that a code object’s
     co_lnotab can contain invalid bytecode offsets.

   - bpo-38148(61): Add slots to *note asyncio: b. transport classes,
     which can reduce memory usage.

   - bpo-38142(62): The _hashlib OpenSSL wrapper extension module is now
     PEP-384 compliant.

   - bpo-9216(63): hashlib constructors now support usedforsecurity flag
     to signal that a hashing algorithm is not used in a security
     context.

   - bpo-36991(64): Fixes a potential incorrect AttributeError exception
     escaping ZipFile.extract() in some unsupported input error
     situations.

   - bpo-38134(65): Remove obsolete copy of PBKDF2_HMAC_fast.  All
     supported OpenSSL versions contain a fast implementation.

   - bpo-38132(66): The OpenSSL hashlib wrapper uses a simpler
     implementation.  Several Macros and pointless caches are gone.  The
     hash name now comes from OpenSSL’s EVP. The algorithm name stays
     the same, except it is now always lower case.

   - bpo-38008(67): Fix parent class check in protocols to correctly
     identify the module that provides a builtin protocol, instead of
     assuming they all come from the *note collections.abc: 1f. module

   - bpo-34037(68): For *note asyncio: b, add a new coroutine
     ‘loop.shutdown_default_executor()’.  The new coroutine provides an
     API to schedule an executor shutdown that waits on the threadpool
     to finish closing.  Also, *note asyncio.run(): 2f3. has been
     updated to utilize the new coroutine.  Patch by Kyle Stanley.

   - bpo-37405(69): Fixed regression bug for socket.getsockname() for
     non-CAN_ISOTP AF_CAN address family sockets by returning a 1-tuple
     instead of string.

   - bpo-38121(70): Update parameter names on functions in
     importlib.metadata matching the changes in the 0.22 release of
     importlib_metadata.

   - bpo-38110(71): The os.closewalk() implementation now uses the libc
     fdwalk() API on platforms where it is available.

   - bpo-38093(72): Fixes AsyncMock so it doesn’t crash when used with
     AsyncContextManagers or AsyncIterators.

   - bpo-37488(73): Add warning to ‘datetime.utctimetuple()’,
     ‘datetime.utcnow()’ and ‘datetime.utcfromtimestamp()’ .

   - bpo-35640(74): Allow passing a *note path-like object: 5a1. as
     ‘directory’ argument to the *note
     http.server.SimpleHTTPRequestHandler: d3a. class.  Patch by Géry
     Ogam.

   - bpo-38086(75): Update importlib.metadata with changes from
     importlib_metadata 0.21(76).

   - bpo-37251(77): Remove ‘__code__’ check in AsyncMock that
     incorrectly evaluated function specs as async objects but failed to
     evaluate classes with ‘__await__’ but no ‘__code__’ attribute
     defined as async objects.

   - bpo-38037(78): Fix reference counters in the *note signal: cb.
     module.

   - bpo-38066(79): Hide internal asyncio.Stream methods: feed_eof(),
     feed_data(), set_exception() and set_transport().

   - bpo-38059(80): inspect.py now uses sys.exit() instead of exit()

   - bpo-38049(81): Added command-line interface for the *note ast: 9.
     module.

   - bpo-37953(82): In *note typing: 10a, improved the ‘__hash__’ and
     ‘__eq__’ methods for ‘ForwardReferences’.

   - bpo-38026(83): Fixed *note inspect.getattr_static(): 6bd. used
     ‘isinstance’ while it should avoid dynamic lookup.

   - bpo-35923(84): Update *note importlib.machinery.BuiltinImporter:
     eaf. to use ‘loader._ORIGIN’ instead of a hardcoded value.  Patch
     by Donghee Na.

   - bpo-38010(85): In ‘importlib.metadata’ sync with
     ‘importlib_metadata’ 0.20, clarifying behavior of ‘files()’ and
     fixing issue where only one requirement was returned for
     ‘requires()’ on ‘dist-info’ packages.

   - bpo-38006(86): weakref.WeakValueDictionary defines a local remove()
     function used as callback for weak references.  This function was
     created with a closure.  Modify the implementation to avoid the
     closure.

   - bpo-37995(87): Added the 'indent' option to *note ast.dump(): ae3.
     which allows it to produce a multiline indented output.

   - bpo-34410(88): Fixed a crash in the ‘tee()’ iterator when re-enter
     it.  RuntimeError is now raised in this case.

   - bpo-37140(89): Fix a ctypes regression of Python 3.8.  When a
     ctypes.Structure is passed by copy to a function, ctypes internals
     created a temporary object which had the side effect of calling the
     structure finalizer (__del__) twice.  The Python semantics requires
     a finalizer to be called exactly once.  Fix ctypes internals to no
     longer call the finalizer twice.

   - bpo-37587(90): ‘_json.scanstring’ is now up to 3x faster when there
     are many backslash escaped characters in the JSON string.

   - bpo-37834(91): Prevent shutil.rmtree exception when built on
     non-Windows system without fd system call support, like older
     versions of macOS.

   - bpo-10978(92): Semaphores and BoundedSemaphores can now release
     more than one waiting thread at a time.

   - bpo-37972(93): Subscripts to the ‘unittest.mock.call’ objects now
     receive the same chaining mechanism as any other custom attributes,
     so that the following usage no longer raises a ‘TypeError’:

     ‘call().foo().__getitem__('bar')’

     Patch by blhsing

   - bpo-37965(94): Fix C compiler warning caused by
     distutils.ccompiler.CCompiler.has_function.

   - bpo-37964(95): Add ‘F_GETPATH’ command to *note fcntl: 5d.

   - bpo-37960(96): ‘repr()’ of buffered and text streams now silences
     only expected exceptions when get the value of «name» and «mode»
     attributes.

   - bpo-37961(97): Add a ‘total_nframe’ field to the traces collected
     by the tracemalloc module.  This field indicates the original
     number of frames before it was truncated.

   - bpo-37951(98): Most features of the subprocess module now work
     again in subinterpreters.  Only 'preexec_fn' is restricted in
     subinterpreters.

   - bpo-36205(99): Fix the rusage implementation of time.process_time()
     to correctly report the sum of the system and user CPU time.

   - bpo-37950(100): Fix *note ast.dump(): ae3. when call with
     incompletely initialized node.

   - bpo-34679(101): Restores instantiation of Windows IOCP event loops
     from the non-main thread.

   - bpo-36917(102): Add default implementation of the *note
     ast.NodeVisitor.visit_Constant(): c65. method which emits a
     deprecation warning and calls corresponding methods ‘visit_Num()’,
     ‘visit_Str()’, etc.

   - bpo-37798(103): Update test_statistics.py to verify that the
     statistics module works well for both C and Python implementations.
     Patch by Donghee Na

   - bpo-26589(104): Added a new status code to the http module: 451
     UNAVAILABLE_FOR_LEGAL_REASONS

   - bpo-37915(105): Fix a segmentation fault that appeared when
     comparing instances of ‘datetime.timezone’ and ‘datetime.tzinfo’
     objects.  Patch by Pablo Galindo.

   - bpo-32554(106): Deprecate having random.seed() call hash on
     arbitrary types.

   - bpo-9938(107): Add optional keyword argument ‘exit_on_error’ for
     ‘ArgumentParser’.

   - bpo-37851(108): The *note faulthandler: 5c. module no longer
     allocates its alternative stack at Python startup.  Now the stack
     is only allocated at the first faulthandler usage.

   - bpo-32793(109): Fix a duplicated debug message when *note
     smtplib.SMTP.connect(): 1d97. is called.

   - bpo-37885(110): venv: Don’t generate unset variable warning on
     deactivate.

   - bpo-37868(111): Fix dataclasses.is_dataclass when given an instance
     that never raises AttributeError in __getattr__.  That is, an
     object that returns something for __dataclass_fields__ even if it’s
     not a dataclass.

   - bpo-37811(112): Fix ‘socket’ module’s ‘socket.connect(address)’
     function being unable to establish connection in case of
     interrupted system call.  The problem was observed on all OSes
     which ‘poll(2)’ system call can take only non-negative integers and
     -1 as a timeout value.

   - bpo-37863(113): Optimizations for Fraction.__hash__ suggested by
     Tim Peters.

   - bpo-21131(114): Fix ‘faulthandler.register(chain=True)’ stack.
     faulthandler now allocates a dedicated stack of ‘SIGSTKSZ*2’ bytes,
     instead of just ‘SIGSTKSZ’ bytes.  Calling the previous signal
     handler in faulthandler signal handler uses more than ‘SIGSTKSZ’
     bytes of stack memory on some platforms.

   - bpo-37798(115): Add C fastpath for statistics.NormalDist.inv_cdf()
     Patch by Donghee Na

   - bpo-37804(116): Remove the deprecated method
     ‘threading.Thread.isAlive()’.  Patch by Donghee Na.

   - bpo-37819(117): Add Fraction.as_integer_ratio() to match the
     corresponding methods in bool, int, float, and decimal.

   - bpo-14465(118): Add an xml.etree.ElementTree.indent() function for
     pretty-printing XML trees.  Contributed by Stefan Behnel.

   - bpo-37810(119): Fix *note difflib: 3b. ‘?’ hint in diff output when
     dealing with tabs.  Patch by Anthony Sottile.

   - bpo-37772(120): In ‘zipfile.Path’, when adding implicit dirs,
     ensure that ancestral directories are added and that duplicates are
     excluded.

   - bpo-18578(121): Renamed and documented ‘test.bytecode_helper’ as
     ‘test.support.bytecode_helper’.  Patch by Joannah Nanjekye.

   - bpo-37785(122): Fix xgettext warnings in *note argparse: 7.

   - bpo-34488(123): ‘writelines()’ method of *note io.BytesIO: 10a6. is
     now slightly faster when many small lines are passed.  Patch by
     Sergey Fedoseev.

   - bpo-37449(124): ‘ensurepip’ now uses
     ‘importlib.resources.read_binary()’ to read data instead of
     ‘pkgutil.get_data()’.  Patch by Joannah Nanjekye.

   - bpo-28292(125): Mark calendar.py helper functions as being private.
     The follows PEP 8 guidance to maintain the style conventions in the
     module and it addresses a known case of user confusion.

   - bpo-18049(126): Add definition of THREAD_STACK_SIZE for AIX in
     Python/thread_pthread.h The default thread stacksize caused crashes
     with the default recursion limit Patch by M Felt

   - bpo-37742(127): The logging.getLogger() API now returns the root
     logger when passed the name “root”, whereas previously it returned
     a non-root logger named “root”.  This could affect cases where user
     code explicitly wants a non-root logger named “root”, or
     instantiates a logger using logging.getLogger(__name__) in some
     top-level module called “root.py”.

   - bpo-37738(128): Fix the implementation of curses ‘addch(str,
     color_pair)’: pass the color pair to ‘setcchar()’, instead of
     always passing 0 as the color pair.

   - bpo-37723(129): Fix performance regression on regular expression
     parsing with huge character sets.  Patch by Yann Vaginay.

   - bpo-35943(130): The function *note PyImport_GetModule(): dae. now
     ensures any module it returns is fully initialized.  Patch by
     Joannah Nanjekye.

   - bpo-32178(131): Fix IndexError in *note email: 3f. package when
     trying to parse invalid address fields starting with ‘:’.

   - bpo-37268(132): The ‘parser’ module is deprecated and will be
     removed in future versions of Python.

   - bpo-11953(133): Completing WSA* error codes in *note socket: d1.

   - bpo-37685(134): Fixed comparisons of *note datetime.timedelta: bc5.
     and *note datetime.timezone: 12c7.

   - bpo-37697(135): Synchronize ‘importlib.metadata’ with
     importlib_metadata 0.19(136), improving handling of EGG-INFO files
     and fixing a crash when entry point names contained colons.

   - bpo-37695(137): Correct *note curses.unget_wch(): 12a0. error
     message.  Patch by Anthony Sottile.

   - bpo-37689(138): Add ‘is_relative_to()’ in ‘PurePath’ to determine
     whether or not one path is relative to another.

   - bpo-29553(139): Fixed *note argparse.ArgumentParser.format_usage():
     1d98. for mutually exclusive groups.  Patch by Andrew Nester.

   - bpo-37691(140): Let math.dist() accept coordinates as sequences (or
     iterables) rather than just tuples.

   - bpo-37685(141): Fixed ‘__eq__’, ‘__lt__’ etc implementations in
     some classes.  They now return *note NotImplemented: 1a2. for
     unsupported type of the other operand.  This allows the other
     operand to play role (for example the equality comparison with
     *note ANY: 1d99. will return ‘True’).

   - bpo-37354(142): Make Activate.ps1 Powershell script static to allow
     for signing it.

   - bpo-37664(143): Update wheels bundled with ensurepip (pip 19.2.3
     and setuptools 41.2.0)

   - bpo-37663(144): Bring consistency to venv shell activation scripts
     by always using __VENV_PROMPT__.

   - bpo-37642(145): Allowed the pure Python implementation of *note
     datetime.timezone: 12c7. to represent sub-minute offsets close to
     minimum and maximum boundaries, specifically in the ranges (23:59,
     24:00) and (-23:59, 24:00).  Patch by Ngalim Siregar

   - bpo-36161(146): In *note posix: b2, use ‘ttyname_r’ instead of
     ‘ttyname’ for thread safety.

   - bpo-36324(147): Make internal attributes for
     statistics.NormalDist() private.

   - bpo-37555(148): Fix ‘NonCallableMock._call_matcher’ returning tuple
     instead of ‘_Call’ object when ‘self._spec_signature’ exists.
     Patch by Elizabeth Uselton

   - bpo-29446(149): Make ‘from tkinter import *’ import only the
     expected objects.

   - bpo-16970(150): Adding a value error when an invalid value in
     passed to nargs Patch by Robert Leenders

   - bpo-34443(151): Exceptions from *note enum: 5a. now use the
     ‘__qualname’ of the enum class in the exception message instead of
     the ‘__name__’.

   - bpo-37491(152): Fix ‘IndexError’ when parsing email headers with
     unexpectedly ending bare-quoted string value.  Patch by Abhilash
     Raj.

   - bpo-37587(153): Make json.loads faster for long strings.  (Patch by
     Marco Paolini)

   - bpo-18378(154): Recognize «UTF-8» as a valid value for LC_CTYPE in
     locale._parse_localename.

   - bpo-37579(155): Return *note NotImplemented: 1a2. in Python
     implementation of ‘__eq__’ for *note timedelta: bc5. and *note
     time: 1fb. when the other object being compared is not of the same
     type to match C implementation.  Patch by Karthikeyan Singaravelan.

   - bpo-21478(156): Record calls to parent when autospecced object is
     attached to a mock using ‘unittest.mock.attach_mock()’.  Patch by
     Karthikeyan Singaravelan.

   - bpo-37531(157): «python3 -m test -jN –timeout=TIMEOUT» now kills a
     worker process if it runs longer than 'TIMEOUT' seconds.

   - bpo-37482(158): Fix serialization of display name in originator or
     destination address fields with both encoded words and special
     chars.

   - bpo-36993(159): Improve error reporting for corrupt zip files with
     bad zip64 extra data.  Patch by Daniel Hillier.

   - bpo-37502(160): pickle.loads() no longer raises TypeError when the
     buffers argument is set to None

   - bpo-37520(161): Correct behavior for zipfile.Path.parent when the
     path object identifies a subdirectory.

   - bpo-18374(162): Fix the ‘.col_offset’ attribute of nested *note
     ast.BinOp: 1d9a. instances which had a too large value in some
     situations.

   - bpo-37424(163): Fixes a possible hang when using a timeout on
     ‘subprocess.run()’ while capturing output.  If the child process
     spawned its own children or otherwise connected its stdout or
     stderr handles with another process, we could hang after the
     timeout was reached and our child was killed when attempting to
     read final output from the pipes.

   - bpo-37421(164): Fix ‘multiprocessing.util.get_temp_dir()’
     finalizer: clear also the “tempdir” configuration of the current
     process, so next call to ‘get_temp_dir()’ will create a new
     temporary directory, rather than reusing the removed temporary
     directory.

   - bpo-37481(165): The distutils ‘bdist_wininst’ command is deprecated
     in Python 3.8, use ‘bdist_wheel’ (wheel packages) instead.

   - bpo-37479(166): When ‘Enum.__str__’ is overridden in a derived
     class, the override will be used by ‘Enum.__format__’ regardless of
     whether mixin classes are present.

   - bpo-37440(167): http.client now enables TLS 1.3 post-handshake
     authentication for default context or if a cert_file is passed to
     HTTPSConnection.

   - bpo-37437(168): Update vendorized expat version to 2.2.7.

   - bpo-37428(169): SSLContext.post_handshake_auth = True no longer
     sets SSL_VERIFY_POST_HANDSHAKE verify flag for client connections.
     Although the option is documented as ignored for clients, OpenSSL
     implicitly enables cert chain validation when the flag is set.

   - bpo-37420(170): *note os.sched_setaffinity(): 1316. now correctly
     handles errors that arise during iteration over its ‘mask’
     argument.  Patch by Brandt Bucher.

   - bpo-37412(171): The *note os.getcwdb(): c84. function now uses the
     UTF-8 encoding on Windows, rather than the ANSI code page: see PEP
     529(172) for the rationale.  The function is no longer deprecated
     on Windows.

   - bpo-37406(173): The sqlite3 module now raises TypeError, rather
     than ValueError, if operation argument type is not str: execute(),
     executemany() and calling a connection.

   - bpo-29412(174): Fix IndexError in parsing a header value ending
     unexpectedly.  Patch by Abhilash Raj.

   - bpo-36546(175): The 'dist' argument for statistics.quantiles() is
     now positional only.  The current name doesn’t reflect that the
     argument can be either a dataset or a distribution.  Marking the
     parameter as positional avoids confusion and makes it possible to
     change the name later.

   - bpo-37394(176): Fix a bug that was causing the *note queue: bb.
     module to fail if the accelerator module was not available.  Patch
     by Pablo Galindo.

   - bpo-37376(177): *note pprint: b3. now has support for *note
     types.SimpleNamespace: 4e6.  Patch by Carl Bordum Hansen.

   - bpo-26967(178): An *note ArgumentParser: 1bd. with
     ‘allow_abbrev=False’ no longer disables grouping of short flags,
     such as ‘-vv’, but only disables abbreviation of long flags as
     documented.  Patch by Zac Hatfield-Dodds.

   - bpo-37212(179): *note unittest.mock.call(): 1d9b. now preserves the
     order of keyword arguments in repr output.  Patch by Karthikeyan
     Singaravelan.

   - bpo-37372(180): Fix error unpickling datetime.time objects from
     Python 2 with seconds>=24.  Patch by Justin Blanchard.

   - bpo-37345(181): Add formal support for UDPLITE sockets.  Support
     was present before, but it is now easier to detect support with
     ‘hasattr(socket, 'IPPROTO_UDPLITE')’ and there are constants
     defined for each of the values needed: ‘socket.IPPROTO_UDPLITE’,
     ‘UDPLITE_SEND_CSCOV’, and ‘UDPLITE_RECV_CSCOV’.  Patch by Gabe
     Appleton.

   - bpo-37358(182): Optimized ‘functools.partial’ by using vectorcall.

   - bpo-37347(183): *note sqlite3.Connection.create_aggregate(): 5a8,
     *note sqlite3.Connection.create_function(): 5a7, *note
     sqlite3.Connection.set_authorizer(): 5a9, *note
     sqlite3.Connection.set_progress_handler(): 5aa. *note
     sqlite3.Connection.set_trace_callback(): 5ab. methods lead to
     segfaults if some of these methods are called twice with an equal
     object but not the same.  Now callbacks are stored more carefully.
     Patch by Aleksandr Balezin.

   - bpo-37163(184): The 'obj' argument of *note dataclasses.replace():
     1a52. is positional-only now.

   - bpo-37085(185): Add the optional Linux SocketCAN Broadcast Manager
     constants, used as flags to configure the BCM behaviour, in the
     socket module.  Patch by Karl Ding.

   - bpo-37328(186): ‘HTMLParser.unescape’ is removed.  It was
     undocumented and deprecated since Python 3.4.

   - bpo-37305(187): Add .webmanifest -> application/manifest+json to
     list of recognized file types and content type headers

   - bpo-37320(188): ‘aifc.openfp()’ alias to ‘aifc.open()’,
     ‘sunau.openfp()’ alias to ‘sunau.open()’, and ‘wave.openfp()’ alias
     to ‘wave.open()’ have been removed.  They were deprecated since
     Python 3.7.

   - bpo-37315(189): Deprecated accepting floats with integral value
     (like ‘5.0’) in *note math.factorial(): b43.

   - bpo-37312(190): ‘_dummy_thread’ and ‘dummy_threading’ modules have
     been removed.  These modules were deprecated since Python 3.7 which
     requires threading support.

   - bpo-33972(191): Email with single part but content-type set to
     ‘multipart/*’ doesn’t raise AttributeError anymore.

   - bpo-37280(192): Use threadpool for reading from file for sendfile
     fallback mode.

   - bpo-37279(193): Fix asyncio sendfile support when sendfile sends
     extra data in fallback mode.

   - bpo-19865(194): *note ctypes.create_unicode_buffer(): 1d9c. now
     also supports non-BMP characters on platforms with 16-bit ‘wchar_t’
     (for example, Windows and AIX).

   - bpo-37266(195): In a subinterpreter, spawning a daemon thread now
     raises an exception.  Daemon threads were never supported in
     subinterpreters.  Previously, the subinterpreter finalization
     crashed with a Python fatal error if a daemon thread was still
     running.

   - bpo-37210(196): Allow pure Python implementation of *note pickle:
     ab. to work even when the C ‘_pickle’ module is unavailable.

   - bpo-21872(197): Fix *note lzma: 8e.: module decompresses data
     incompletely.  When decompressing a FORMAT_ALONE format file, and
     it doesn’t have the end marker, sometimes the last one to dozens
     bytes can’t be output.  Patch by Ma Lin.

   - bpo-35922(198): Fix ‘RobotFileParser.crawl_delay()’ and
     ‘RobotFileParser.request_rate()’ to return ‘None’ rather than raise
     *note AttributeError: 5f0. when no relevant rule is defined in the
     robots.txt file.  Patch by Rémi Lapeyre.

   - bpo-35766(199): Change the format of feature_version to be a
     (major, minor) tuple.

   - bpo-36607(200): Eliminate *note RuntimeError: 244. raised by *note
     asyncio.all_tasks(): b51. if internal tasks weak set is changed by
     another thread during iteration.

   - bpo-18748(201): ‘_pyio.IOBase’ destructor now does nothing if
     getting the ‘closed’ attribute fails to better mimic ‘_io.IOBase’
     finalizer.

   - bpo-36402(202): Fix a race condition at Python shutdown when
     waiting for threads.  Wait until the Python thread state of all
     non-daemon threads get deleted (join all non-daemon threads),
     rather than just wait until non-daemon Python threads complete.

   - bpo-37206(203): Default values which cannot be represented as
     Python objects no longer improperly represented as ‘None’ in
     function signatures.

   - bpo-37111(204): Added ‘encoding’ and ‘errors’ keyword parameters to
     ‘logging.basicConfig’.

   - bpo-12144(205): Ensure cookies with ‘expires’ attribute are handled
     in ‘CookieJar.make_cookies()’.

   - bpo-34886(206): Fix an unintended ValueError from *note
     subprocess.run(): d81. when checking for conflicting 'input' and
     'stdin' or 'capture_output' and 'stdout' or 'stderr' args when they
     were explicitly provided but with ‘None’ values within a passed in
     ‘**kwargs’ dict rather than as passed directly by name.  Patch
     contributed by Rémi Lapeyre.

   - bpo-37173(207): The exception message for ‘inspect.getfile()’ now
     correctly reports the passed class rather than the builtins module.

   - bpo-37178(208): Give math.perm() a one argument form that means the
     same as math.factorial().

   - bpo-37178(209): For math.perm(n, k), let k default to n, giving the
     same result as factorial.

   - bpo-37165(210): Converted _collections._count_elements to use the
     Argument Clinic.

   - bpo-34767(211): Do not always create a *note collections.deque:
     7f5. in *note asyncio.Lock: c68.

   - bpo-37158(212): Speed-up statistics.fmean() by switching from a
     function to a generator.

   - bpo-34282(213): Remove ‘Enum._convert’ method, deprecated in 3.8.

   - bpo-37150(214): ‘argparse._ActionsContainer.add_argument’ now
     throws error, if someone accidentally pass FileType class object
     instead of instance of FileType as ‘type’ argument.

   - bpo-28724(215): The socket module now has the *note
     socket.send_fds(): b2f. and ‘socket.recv.fds()’ methods.
     Contributed by Joannah Nanjekye, Shinya Okano and Victor Stinner.

   - bpo-35621(216): Support running asyncio subprocesses when execution
     event loop in a thread on UNIX.

   - bpo-36520(217): Lengthy email headers with UTF-8 characters are now
     properly encoded when they are folded.  Patch by Jeffrey Kintscher.

   - bpo-30835(218): Fixed a bug in email parsing where a message with
     invalid bytes in content-transfer-encoding of a multipart message
     can cause an AttributeError.  Patch by Andrew Donnellan.

   - bpo-31163(219): pathlib.Path instance’s rename and replace methods
     now return the new Path instance.

   - bpo-25068(220): *note urllib.request.ProxyHandler: 1d9d. now
     lowercases the keys of the passed dictionary.

   - bpo-26185(221): Fix *note repr(): 1c1. on empty ‘ZipInfo’ object.
     Patch by Mickaël Schoentgen.

   - bpo-21315(222): Email headers containing RFC2047 encoded words are
     parsed despite the missing whitespace, and a defect registered.
     Also missing trailing whitespace after encoded words is now
     registered as a defect.

   - bpo-31904(223): Port test_datetime to VxWorks: skip zoneinfo tests
     on VxWorks

   - bpo-35805(224): Add parser for Message-ID header and add it to
     default HeaderRegistry.  This should prevent folding of Message-ID
     using RFC 2048 encoded words.

   - bpo-36871(225): Ensure method signature is used instead of
     constructor signature of a class while asserting mock object
     against method calls.  Patch by Karthikeyan Singaravelan.

   - bpo-35070(226): posix.getgrouplist() now works correctly when the
     user belongs to NGROUPS_MAX supplemental groups.  Patch by Jeffrey
     Kintscher.

   - bpo-31783(227): Fix race condition in ThreadPoolExecutor when
     worker threads are created during interpreter shutdown.

   - bpo-36582(228): Fix ‘UserString.encode()’ to correctly return
     ‘bytes’ rather than a ‘UserString’ instance.

   - bpo-32424(229): Deprecate xml.etree.ElementTree.Element.copy() in
     favor of copy.copy().

     Patch by Gordon P. Hemsley

   - bpo-36564(230): Fix infinite loop in email header folding logic
     that would be triggered when an email policy’s max_line_length is
     not long enough to include the required markup and any values in
     the message.  Patch by Paul Ganssle

   - bpo-36543(231): Removed methods Element.getchildren(),
     Element.getiterator() and ElementTree.getiterator() and the
     xml.etree.cElementTree module.

   - bpo-36409(232): Remove the old plistlib API deprecated in Python
     3.4

   - bpo-36302(233): distutils sorts source file lists so that Extension
     .so files build more reproducibly by default

   - bpo-36250(234): Ignore ‘ValueError’ from ‘signal’ with
     ‘interaction’ in non-main thread.

   - bpo-36046(235): Added ‘user’, ‘group’ and ‘extra_groups’ parameters
     to the subprocess.Popen constructor.  Patch by Patrick McLean.

   - bpo-32627(236): Fix compile error when ‘_uuid’ headers conflicting
     included.

   - bpo-35800(237): Deprecate ‘smtpd.MailmanProxy’ ready for future
     removal.

   - bpo-35168(238): *note shlex.shlex.punctuation_chars: 1d9e. is now a
     read-only property.

   - bpo-8538(239): Add support for boolean actions like ‘--foo’ and
     ‘--no-foo’ to argparse.  Patch contributed by Rémi Lapeyre.

   - bpo-20504(240): Fixes a bug in ‘cgi’ module when a
     multipart/form-data request has no ‘Content-Length’ header.

   - bpo-25988(241): The abstract base classes in *note collections.abc:
     1f. no longer are exposed in the regular *note collections: 1e.
     module.

   - bpo-11122(242): Distutils won’t check for rpmbuild in specified
     paths only.

   - bpo-34775(243): Division handling of PurePath now returns
     NotImplemented instead of raising a TypeError when passed something
     other than an instance of str or PurePath.  Patch by Roger Aiudi.

   - bpo-34749(244): *note binascii.a2b_base64(): 198c. is now up to 2
     times faster.  Patch by Sergey Fedoseev.

   - bpo-34519(245): Add additional aliases for HP Roman 8.  Patch by
     Michael Osipov.

   - bpo-28009(246): Fix uuid.getnode() on platforms with “.” as MAC
     Addr delimiter as well fix for MAC Addr format that omits a leading
     0 in MAC Addr values.  Currently, AIX is the only know platform
     with these settings.  Patch by Michael Felt.

   - bpo-30618(247): Add *note readlink(): b1b.  Patch by Girts
     Folkmanis.

   - bpo-32498(248): Made *note urllib.parse.unquote(): 1ae3. accept
     bytes in addition to strings.  Patch by Stein Karlsen.

   - bpo-33348(249): lib2to3 now recognizes expressions after ‘*’ and
     ‘**’ like in ‘f(*[] or [])’.

   - bpo-32689(250): Update *note shutil.move(): c53. function to allow
     for Path objects to be used as source argument.  Patch by Emily
     Morehouse and Maxwell «5.13b» McKinnon.

   - bpo-32820(251): Added ‘__format__’ to IPv4 and IPv6 classes.
     Always outputs a fully zero-padded string.  Supports b/x/n
     modifiers (bin/hex/native format).  Native format for IPv4 is bin,
     native format for IPv6 is hex.  Also supports “#” and “_”
     modifiers.

   - bpo-27657(252): Fix urllib.parse.urlparse() with numeric paths.  A
     string like «path:80» is no longer parsed as a path but as a scheme
     («path») and a path («80»).

   - bpo-4963(253): Fixed non-deterministic behavior related to
     mimetypes extension mapping and module reinitialization.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36589

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38807

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38724

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38786

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38785

   (6) https://bugs.python.org/issue?@action=redirect&bpo=38723

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27805

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38438

   (9) https://bugs.python.org/issue?@action=redirect&bpo=38761

   (10) https://bugs.python.org/issue?@action=redirect&bpo=38716

   (11) https://bugs.python.org/issue?@action=redirect&bpo=38713

   (12) https://bugs.python.org/issue?@action=redirect&bpo=38692

   (13) https://bugs.python.org/issue?@action=redirect&bpo=38692

   (14) https://bugs.python.org/issue?@action=redirect&bpo=38602

   (15) https://bugs.python.org/issue?@action=redirect&bpo=38334

   (16) https://bugs.python.org/issue?@action=redirect&bpo=38312

   (17) https://bugs.python.org/issue?@action=redirect&bpo=38586

   (18) https://bugs.python.org/issue?@action=redirect&bpo=38565

   (19) https://bugs.python.org/issue?@action=redirect&bpo=34679

   (20) https://bugs.python.org/issue?@action=redirect&bpo=31202

   (21) https://bugs.python.org/issue?@action=redirect&bpo=36321

   (22) https://bugs.python.org/issue?@action=redirect&bpo=38521

   (23) https://bugs.python.org/issue?@action=redirect&bpo=38493

   (24) https://bugs.python.org/issue?@action=redirect&bpo=38478

   (25) https://bugs.python.org/issue?@action=redirect&bpo=33604

   (26) https://bugs.python.org/issue?@action=redirect&bpo=38378

   (27) https://bugs.python.org/issue?@action=redirect&bpo=38417

   (28) https://bugs.python.org/issue?@action=redirect&bpo=38449

   (29) https://bugs.python.org/issue?@action=redirect&bpo=38431

   (30) https://bugs.python.org/issue?@action=redirect&bpo=38109

   (31) https://bugs.python.org/issue?@action=redirect&bpo=38422

   (32) https://bugs.python.org/issue?@action=redirect&bpo=38405

   (33) https://bugs.python.org/issue?@action=redirect&bpo=38332

   (34) https://bugs.python.org/issue?@action=redirect&bpo=38371

   (35) https://bugs.python.org/issue?@action=redirect&bpo=38341

   (36) https://bugs.python.org/issue?@action=redirect&bpo=38319

   (37) https://bugs.python.org/issue?@action=redirect&bpo=38242

   (38) https://bugs.python.org/issue?@action=redirect&bpo=13153

   (39) https://bugs.python.org/issue?@action=redirect&bpo=38019

   (40) https://bugs.python.org/issue?@action=redirect&bpo=38163

   (41) https://bugs.python.org/issue?@action=redirect&bpo=38161

   (42) https://bugs.python.org/issue?@action=redirect&bpo=38216

   (43) https://bugs.python.org/issue?@action=redirect&bpo=30458

   (44) https://bugs.python.org/issue?@action=redirect&bpo=28286

   (45) https://bugs.python.org/issue?@action=redirect&bpo=38108

   (46) https://bugs.python.org/issue?@action=redirect&bpo=38265

   (47) https://bugs.python.org/issue?@action=redirect&bpo=38112

   (48) https://bugs.python.org/issue?@action=redirect&bpo=38248

   (49) https://bugs.python.org/issue?@action=redirect&bpo=38237

   (50) https://bugs.python.org/issue?@action=redirect&bpo=34002

   (51) https://bugs.python.org/issue?@action=redirect&bpo=38191

   (52) https://bugs.python.org/issue?@action=redirect&bpo=38155

   (53) https://bugs.python.org/issue?@action=redirect&bpo=38185

   (54) https://bugs.python.org/issue?@action=redirect&bpo=38136

   (55) https://bugs.python.org/issue?@action=redirect&bpo=37828

   (56) https://bugs.python.org/issue?@action=redirect&bpo=38175

   (57) https://bugs.python.org/issue?@action=redirect&bpo=33936

   (58) https://bugs.python.org/issue?@action=redirect&bpo=34706

   (59) https://bugs.python.org/issue?@action=redirect&bpo=38153

   (60) https://bugs.python.org/issue?@action=redirect&bpo=38115

   (61) https://bugs.python.org/issue?@action=redirect&bpo=38148

   (62) https://bugs.python.org/issue?@action=redirect&bpo=38142

   (63) https://bugs.python.org/issue?@action=redirect&bpo=9216

   (64) https://bugs.python.org/issue?@action=redirect&bpo=36991

   (65) https://bugs.python.org/issue?@action=redirect&bpo=38134

   (66) https://bugs.python.org/issue?@action=redirect&bpo=38132

   (67) https://bugs.python.org/issue?@action=redirect&bpo=38008

   (68) https://bugs.python.org/issue?@action=redirect&bpo=34037

   (69) https://bugs.python.org/issue?@action=redirect&bpo=37405

   (70) https://bugs.python.org/issue?@action=redirect&bpo=38121

   (71) https://bugs.python.org/issue?@action=redirect&bpo=38110

   (72) https://bugs.python.org/issue?@action=redirect&bpo=38093

   (73) https://bugs.python.org/issue?@action=redirect&bpo=37488

   (74) https://bugs.python.org/issue?@action=redirect&bpo=35640

   (75) https://bugs.python.org/issue?@action=redirect&bpo=38086

   (76) 
https://gitlab.com/python-devs/importlib_metadata/blob/0.21/importlib_metadata/docs/changelog.rst

   (77) https://bugs.python.org/issue?@action=redirect&bpo=37251

   (78) https://bugs.python.org/issue?@action=redirect&bpo=38037

   (79) https://bugs.python.org/issue?@action=redirect&bpo=38066

   (80) https://bugs.python.org/issue?@action=redirect&bpo=38059

   (81) https://bugs.python.org/issue?@action=redirect&bpo=38049

   (82) https://bugs.python.org/issue?@action=redirect&bpo=37953

   (83) https://bugs.python.org/issue?@action=redirect&bpo=38026

   (84) https://bugs.python.org/issue?@action=redirect&bpo=35923

   (85) https://bugs.python.org/issue?@action=redirect&bpo=38010

   (86) https://bugs.python.org/issue?@action=redirect&bpo=38006

   (87) https://bugs.python.org/issue?@action=redirect&bpo=37995

   (88) https://bugs.python.org/issue?@action=redirect&bpo=34410

   (89) https://bugs.python.org/issue?@action=redirect&bpo=37140

   (90) https://bugs.python.org/issue?@action=redirect&bpo=37587

   (91) https://bugs.python.org/issue?@action=redirect&bpo=37834

   (92) https://bugs.python.org/issue?@action=redirect&bpo=10978

   (93) https://bugs.python.org/issue?@action=redirect&bpo=37972

   (94) https://bugs.python.org/issue?@action=redirect&bpo=37965

   (95) https://bugs.python.org/issue?@action=redirect&bpo=37964

   (96) https://bugs.python.org/issue?@action=redirect&bpo=37960

   (97) https://bugs.python.org/issue?@action=redirect&bpo=37961

   (98) https://bugs.python.org/issue?@action=redirect&bpo=37951

   (99) https://bugs.python.org/issue?@action=redirect&bpo=36205

   (100) https://bugs.python.org/issue?@action=redirect&bpo=37950

   (101) https://bugs.python.org/issue?@action=redirect&bpo=34679

   (102) https://bugs.python.org/issue?@action=redirect&bpo=36917

   (103) https://bugs.python.org/issue?@action=redirect&bpo=37798

   (104) https://bugs.python.org/issue?@action=redirect&bpo=26589

   (105) https://bugs.python.org/issue?@action=redirect&bpo=37915

   (106) https://bugs.python.org/issue?@action=redirect&bpo=32554

   (107) https://bugs.python.org/issue?@action=redirect&bpo=9938

   (108) https://bugs.python.org/issue?@action=redirect&bpo=37851

   (109) https://bugs.python.org/issue?@action=redirect&bpo=32793

   (110) https://bugs.python.org/issue?@action=redirect&bpo=37885

   (111) https://bugs.python.org/issue?@action=redirect&bpo=37868

   (112) https://bugs.python.org/issue?@action=redirect&bpo=37811

   (113) https://bugs.python.org/issue?@action=redirect&bpo=37863

   (114) https://bugs.python.org/issue?@action=redirect&bpo=21131

   (115) https://bugs.python.org/issue?@action=redirect&bpo=37798

   (116) https://bugs.python.org/issue?@action=redirect&bpo=37804

   (117) https://bugs.python.org/issue?@action=redirect&bpo=37819

   (118) https://bugs.python.org/issue?@action=redirect&bpo=14465

   (119) https://bugs.python.org/issue?@action=redirect&bpo=37810

   (120) https://bugs.python.org/issue?@action=redirect&bpo=37772

   (121) https://bugs.python.org/issue?@action=redirect&bpo=18578

   (122) https://bugs.python.org/issue?@action=redirect&bpo=37785

   (123) https://bugs.python.org/issue?@action=redirect&bpo=34488

   (124) https://bugs.python.org/issue?@action=redirect&bpo=37449

   (125) https://bugs.python.org/issue?@action=redirect&bpo=28292

   (126) https://bugs.python.org/issue?@action=redirect&bpo=18049

   (127) https://bugs.python.org/issue?@action=redirect&bpo=37742

   (128) https://bugs.python.org/issue?@action=redirect&bpo=37738

   (129) https://bugs.python.org/issue?@action=redirect&bpo=37723

   (130) https://bugs.python.org/issue?@action=redirect&bpo=35943

   (131) https://bugs.python.org/issue?@action=redirect&bpo=32178

   (132) https://bugs.python.org/issue?@action=redirect&bpo=37268

   (133) https://bugs.python.org/issue?@action=redirect&bpo=11953

   (134) https://bugs.python.org/issue?@action=redirect&bpo=37685

   (135) https://bugs.python.org/issue?@action=redirect&bpo=37697

   (136) 
https://gitlab.com/python-devs/importlib_metadata/-/milestones/20

   (137) https://bugs.python.org/issue?@action=redirect&bpo=37695

   (138) https://bugs.python.org/issue?@action=redirect&bpo=37689

   (139) https://bugs.python.org/issue?@action=redirect&bpo=29553

   (140) https://bugs.python.org/issue?@action=redirect&bpo=37691

   (141) https://bugs.python.org/issue?@action=redirect&bpo=37685

   (142) https://bugs.python.org/issue?@action=redirect&bpo=37354

   (143) https://bugs.python.org/issue?@action=redirect&bpo=37664

   (144) https://bugs.python.org/issue?@action=redirect&bpo=37663

   (145) https://bugs.python.org/issue?@action=redirect&bpo=37642

   (146) https://bugs.python.org/issue?@action=redirect&bpo=36161

   (147) https://bugs.python.org/issue?@action=redirect&bpo=36324

   (148) https://bugs.python.org/issue?@action=redirect&bpo=37555

   (149) https://bugs.python.org/issue?@action=redirect&bpo=29446

   (150) https://bugs.python.org/issue?@action=redirect&bpo=16970

   (151) https://bugs.python.org/issue?@action=redirect&bpo=34443

   (152) https://bugs.python.org/issue?@action=redirect&bpo=37491

   (153) https://bugs.python.org/issue?@action=redirect&bpo=37587

   (154) https://bugs.python.org/issue?@action=redirect&bpo=18378

   (155) https://bugs.python.org/issue?@action=redirect&bpo=37579

   (156) https://bugs.python.org/issue?@action=redirect&bpo=21478

   (157) https://bugs.python.org/issue?@action=redirect&bpo=37531

   (158) https://bugs.python.org/issue?@action=redirect&bpo=37482

   (159) https://bugs.python.org/issue?@action=redirect&bpo=36993

   (160) https://bugs.python.org/issue?@action=redirect&bpo=37502

   (161) https://bugs.python.org/issue?@action=redirect&bpo=37520

   (162) https://bugs.python.org/issue?@action=redirect&bpo=18374

   (163) https://bugs.python.org/issue?@action=redirect&bpo=37424

   (164) https://bugs.python.org/issue?@action=redirect&bpo=37421

   (165) https://bugs.python.org/issue?@action=redirect&bpo=37481

   (166) https://bugs.python.org/issue?@action=redirect&bpo=37479

   (167) https://bugs.python.org/issue?@action=redirect&bpo=37440

   (168) https://bugs.python.org/issue?@action=redirect&bpo=37437

   (169) https://bugs.python.org/issue?@action=redirect&bpo=37428

   (170) https://bugs.python.org/issue?@action=redirect&bpo=37420

   (171) https://bugs.python.org/issue?@action=redirect&bpo=37412

   (172) https://peps.python.org/pep-0529/

   (173) https://bugs.python.org/issue?@action=redirect&bpo=37406

   (174) https://bugs.python.org/issue?@action=redirect&bpo=29412

   (175) https://bugs.python.org/issue?@action=redirect&bpo=36546

   (176) https://bugs.python.org/issue?@action=redirect&bpo=37394

   (177) https://bugs.python.org/issue?@action=redirect&bpo=37376

   (178) https://bugs.python.org/issue?@action=redirect&bpo=26967

   (179) https://bugs.python.org/issue?@action=redirect&bpo=37212

   (180) https://bugs.python.org/issue?@action=redirect&bpo=37372

   (181) https://bugs.python.org/issue?@action=redirect&bpo=37345

   (182) https://bugs.python.org/issue?@action=redirect&bpo=37358

   (183) https://bugs.python.org/issue?@action=redirect&bpo=37347

   (184) https://bugs.python.org/issue?@action=redirect&bpo=37163

   (185) https://bugs.python.org/issue?@action=redirect&bpo=37085

   (186) https://bugs.python.org/issue?@action=redirect&bpo=37328

   (187) https://bugs.python.org/issue?@action=redirect&bpo=37305

   (188) https://bugs.python.org/issue?@action=redirect&bpo=37320

   (189) https://bugs.python.org/issue?@action=redirect&bpo=37315

   (190) https://bugs.python.org/issue?@action=redirect&bpo=37312

   (191) https://bugs.python.org/issue?@action=redirect&bpo=33972

   (192) https://bugs.python.org/issue?@action=redirect&bpo=37280

   (193) https://bugs.python.org/issue?@action=redirect&bpo=37279

   (194) https://bugs.python.org/issue?@action=redirect&bpo=19865

   (195) https://bugs.python.org/issue?@action=redirect&bpo=37266

   (196) https://bugs.python.org/issue?@action=redirect&bpo=37210

   (197) https://bugs.python.org/issue?@action=redirect&bpo=21872

   (198) https://bugs.python.org/issue?@action=redirect&bpo=35922

   (199) https://bugs.python.org/issue?@action=redirect&bpo=35766

   (200) https://bugs.python.org/issue?@action=redirect&bpo=36607

   (201) https://bugs.python.org/issue?@action=redirect&bpo=18748

   (202) https://bugs.python.org/issue?@action=redirect&bpo=36402

   (203) https://bugs.python.org/issue?@action=redirect&bpo=37206

   (204) https://bugs.python.org/issue?@action=redirect&bpo=37111

   (205) https://bugs.python.org/issue?@action=redirect&bpo=12144

   (206) https://bugs.python.org/issue?@action=redirect&bpo=34886

   (207) https://bugs.python.org/issue?@action=redirect&bpo=37173

   (208) https://bugs.python.org/issue?@action=redirect&bpo=37178

   (209) https://bugs.python.org/issue?@action=redirect&bpo=37178

   (210) https://bugs.python.org/issue?@action=redirect&bpo=37165

   (211) https://bugs.python.org/issue?@action=redirect&bpo=34767

   (212) https://bugs.python.org/issue?@action=redirect&bpo=37158

   (213) https://bugs.python.org/issue?@action=redirect&bpo=34282

   (214) https://bugs.python.org/issue?@action=redirect&bpo=37150

   (215) https://bugs.python.org/issue?@action=redirect&bpo=28724

   (216) https://bugs.python.org/issue?@action=redirect&bpo=35621

   (217) https://bugs.python.org/issue?@action=redirect&bpo=36520

   (218) https://bugs.python.org/issue?@action=redirect&bpo=30835

   (219) https://bugs.python.org/issue?@action=redirect&bpo=31163

   (220) https://bugs.python.org/issue?@action=redirect&bpo=25068

   (221) https://bugs.python.org/issue?@action=redirect&bpo=26185

   (222) https://bugs.python.org/issue?@action=redirect&bpo=21315

   (223) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (224) https://bugs.python.org/issue?@action=redirect&bpo=35805

   (225) https://bugs.python.org/issue?@action=redirect&bpo=36871

   (226) https://bugs.python.org/issue?@action=redirect&bpo=35070

   (227) https://bugs.python.org/issue?@action=redirect&bpo=31783

   (228) https://bugs.python.org/issue?@action=redirect&bpo=36582

   (229) https://bugs.python.org/issue?@action=redirect&bpo=32424

   (230) https://bugs.python.org/issue?@action=redirect&bpo=36564

   (231) https://bugs.python.org/issue?@action=redirect&bpo=36543

   (232) https://bugs.python.org/issue?@action=redirect&bpo=36409

   (233) https://bugs.python.org/issue?@action=redirect&bpo=36302

   (234) https://bugs.python.org/issue?@action=redirect&bpo=36250

   (235) https://bugs.python.org/issue?@action=redirect&bpo=36046

   (236) https://bugs.python.org/issue?@action=redirect&bpo=32627

   (237) https://bugs.python.org/issue?@action=redirect&bpo=35800

   (238) https://bugs.python.org/issue?@action=redirect&bpo=35168

   (239) https://bugs.python.org/issue?@action=redirect&bpo=8538

   (240) https://bugs.python.org/issue?@action=redirect&bpo=20504

   (241) https://bugs.python.org/issue?@action=redirect&bpo=25988

   (242) https://bugs.python.org/issue?@action=redirect&bpo=11122

   (243) https://bugs.python.org/issue?@action=redirect&bpo=34775

   (244) https://bugs.python.org/issue?@action=redirect&bpo=34749

   (245) https://bugs.python.org/issue?@action=redirect&bpo=34519

   (246) https://bugs.python.org/issue?@action=redirect&bpo=28009

   (247) https://bugs.python.org/issue?@action=redirect&bpo=30618

   (248) https://bugs.python.org/issue?@action=redirect&bpo=32498

   (249) https://bugs.python.org/issue?@action=redirect&bpo=33348

   (250) https://bugs.python.org/issue?@action=redirect&bpo=32689

   (251) https://bugs.python.org/issue?@action=redirect&bpo=32820

   (252) https://bugs.python.org/issue?@action=redirect&bpo=27657

   (253) https://bugs.python.org/issue?@action=redirect&bpo=4963


File: python.info,  Node: Documentation<50>,  Next: Tests<49>,  Prev: Library<156>,  Up: Python 3 9 0 alpha 1

1.24.56.4 Documentation
.......................

   - bpo-21767(1): Explicitly mention abc support in
     functools.singledispatch

   - bpo-38816(2): Provides more details about the interaction between
     ‘fork()’ and CPython’s runtime, focusing just on the C-API. This
     includes cautions about where ‘fork()’ should and shouldn’t be
     called.

   - bpo-38351(3): Modernize *note email: 3f. examples from %-formatting
     to f-strings.

   - bpo-38778(4): Document the fact that *note RuntimeError: 244. is
     raised if *note os.fork(): 4b6. is called in a subinterpreter.

   - bpo-38592(5): Add Brazilian Portuguese to the language switcher at
     Python Documentation website.

   - bpo-38294(6): Add list of no-longer-escaped chars to re.escape
     documentation

   - bpo-38053(7): Modernized the plistlib documentation

   - bpo-26868(8): Fix example usage of *note PyModule_AddObject(): 60b.
     to properly handle errors.

   - bpo-36797(9): Fix a dead link in the distutils API Reference.

   - bpo-37977(10): Warn more strongly and clearly about pickle
     insecurity

   - bpo-37979(11): Added a link to dateutil.parser.isoparse in the
     datetime.fromisoformat documentation.  Patch by Paul Ganssle

   - bpo-12707(12): Deprecate info(), geturl(), getcode() methods in
     favor of the headers, url, and status properties, respectively, for
     HTTPResponse and addinfourl.  Also deprecate the code attribute of
     addinfourl in favor of the status attribute.  Patch by Ashwin
     Ramaswami

   - bpo-37937(13): Mention ‘frame.f_trace’ in *note sys.settrace():
     2e1. docs.

   - bpo-37878(14): Make *note PyThreadState_DeleteCurrent(): 1da0.
     Internal.

   - bpo-37759(15): Beginning edits to Whatsnew 3.8

   - bpo-37726(16): Stop recommending getopt in the tutorial for command
     line argument parsing and promote argparse.

   - bpo-32910(17): Remove implementation-specific behaviour of how
     venv’s Deactivate works.

   - bpo-37256(18): Fix wording of arguments for ‘Request’ in *note
     urllib.request: 111.

   - bpo-37284(19): Add a brief note to indicate that any new
     ‘sys.implementation’ required attributes must go through the PEP
     process.

   - bpo-30088(20): Documented that *note mailbox.Maildir: 65e.
     constructor doesn’t attempt to verify the maildir folder layout
     correctness.  Patch by Sviatoslav Sydorenko.

   - bpo-37521(21): Fix ‘importlib’ examples to insert any newly created
     modules via importlib.util.module_from_spec() immediately into
     sys.modules instead of after calling loader.exec_module().

     Thanks to Benjamin Mintz for finding the bug.

   - bpo-37456(22): Slash (“/”) is now part of syntax.

   - bpo-37487(23): Fix PyList_GetItem index description to include 0.

   - bpo-37149(24): Replace the dead link to the Tkinter 8.5 reference
     by John Shipman, New Mexico Tech, with a link to the archive.org
     copy.

   - bpo-37478(25): Added possible exceptions to the description of
     os.chdir().

   - bpo-34903(26): Documented that in *note
     datetime.datetime.strptime(): 1938, the leading zero in some
     two-digit formats is optional.  Patch by Mike Gleen.

   - bpo-36260(27): Add decompression pitfalls to zipfile module
     documentation.

   - bpo-37004(28): In the documentation for difflib, a note was added
     explicitly warning that the results of SequenceMatcher’s ratio
     method may depend on the order of the input strings.

   - bpo-36960(29): Restructured the *note datetime: 34. docs in the
     interest of making them more user-friendly and improving
     readability.  Patch by Brad Solomon.

   - bpo-36487(30): Make C-API docs clear about what the «main»
     interpreter is.

   - bpo-23460(31): The documentation for decimal string formatting
     using the ‘:g’ specifier has been updated to reflect the correct
     exponential notation cutoff point.  Original patch contributed by
     Tuomas Suutari.

   - bpo-35803(32): Document and test that ‘tempfile’ functions may
     accept a *note path-like object: 5a1. for the ‘dir’ argument.
     Patch by Anthony Sottile.

   - bpo-33944(33): Added a note about the intended use of code in .pth
     files.

   - bpo-34293(34): Fix the Doc/Makefile regarding PAPER environment
     variable and PDF builds

   - bpo-25237(35): Add documentation for tkinter modules

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21767

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38816

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38351

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38778

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38592

   (6) https://bugs.python.org/issue?@action=redirect&bpo=38294

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38053

   (8) https://bugs.python.org/issue?@action=redirect&bpo=26868

   (9) https://bugs.python.org/issue?@action=redirect&bpo=36797

   (10) https://bugs.python.org/issue?@action=redirect&bpo=37977

   (11) https://bugs.python.org/issue?@action=redirect&bpo=37979

   (12) https://bugs.python.org/issue?@action=redirect&bpo=12707

   (13) https://bugs.python.org/issue?@action=redirect&bpo=37937

   (14) https://bugs.python.org/issue?@action=redirect&bpo=37878

   (15) https://bugs.python.org/issue?@action=redirect&bpo=37759

   (16) https://bugs.python.org/issue?@action=redirect&bpo=37726

   (17) https://bugs.python.org/issue?@action=redirect&bpo=32910

   (18) https://bugs.python.org/issue?@action=redirect&bpo=37256

   (19) https://bugs.python.org/issue?@action=redirect&bpo=37284

   (20) https://bugs.python.org/issue?@action=redirect&bpo=30088

   (21) https://bugs.python.org/issue?@action=redirect&bpo=37521

   (22) https://bugs.python.org/issue?@action=redirect&bpo=37456

   (23) https://bugs.python.org/issue?@action=redirect&bpo=37487

   (24) https://bugs.python.org/issue?@action=redirect&bpo=37149

   (25) https://bugs.python.org/issue?@action=redirect&bpo=37478

   (26) https://bugs.python.org/issue?@action=redirect&bpo=34903

   (27) https://bugs.python.org/issue?@action=redirect&bpo=36260

   (28) https://bugs.python.org/issue?@action=redirect&bpo=37004

   (29) https://bugs.python.org/issue?@action=redirect&bpo=36960

   (30) https://bugs.python.org/issue?@action=redirect&bpo=36487

   (31) https://bugs.python.org/issue?@action=redirect&bpo=23460

   (32) https://bugs.python.org/issue?@action=redirect&bpo=35803

   (33) https://bugs.python.org/issue?@action=redirect&bpo=33944

   (34) https://bugs.python.org/issue?@action=redirect&bpo=34293

   (35) https://bugs.python.org/issue?@action=redirect&bpo=25237


File: python.info,  Node: Tests<49>,  Next: Build<57>,  Prev: Documentation<50>,  Up: Python 3 9 0 alpha 1

1.24.56.5 Tests
...............

   - bpo-38614(1): Fix test_communicate() of
     test_asyncio.test_subprocess: use ‘support.LONG_TIMEOUT’ (5
     minutes), instead of just 1 minute.

   - bpo-38614(2): Add timeout constants to *note test.support: ea.:
     *note LOOPBACK_TIMEOUT: 1d84, *note INTERNET_TIMEOUT: 1d85, *note
     SHORT_TIMEOUT: 1c4b. and *note LONG_TIMEOUT: 1d86.

   - bpo-38502(3): test.regrtest now uses process groups in the
     multiprocessing mode (-jN command line option) if process groups
     are available: if *note os.setsid(): 1da2. and *note os.killpg():
     1da3. functions are available.

   - bpo-35998(4): Fix a race condition in
     test_asyncio.test_start_tls_server_1().  Previously, there was a
     race condition between the test main() function which replaces the
     protocol and the test ServerProto protocol which sends ANSWER once
     it gets HELLO. Now, only the test main() function is responsible to
     send data, ServerProto no longer sends data.

   - bpo-38470(5): Fix ‘test_compileall.test_compile_dir_maxlevels()’ on
     Windows without long path support: only create 3 subdirectories
     instead of between 20 and 100 subdirectories.

   - bpo-37531(6): On timeout, regrtest no longer attempts to call
     ‘popen.communicate()’ again: it can hang until all child processes
     using stdout and stderr pipes completes.  Kill the worker process
     and ignores its output.  Change also the faulthandler timeout of
     the main process from 1 minute to 5 minutes, for Python slowest
     buildbots.

   - bpo-38239(7): Fix test_gdb for Link Time Optimization (LTO) builds.

   - bpo-38275(8): test_ssl now handles disabled TLS/SSL versions
     better.  OpenSSL’s crypto policy and run-time settings are
     recognized and tests for disabled versions are skipped.  Tests also
     accept more TLS minimum_versions for platforms that override
     OpenSSL’s default with strict settings.

   - bpo-38271(9): The private keys for test_ssl were encrypted with
     3DES in traditional PKCS#5 format.  3DES and the digest algorithm
     of PKCS#5 are blocked by some strict crypto policies.  Use PKCS#8
     format with AES256 encryption instead.

   - bpo-38270(10): test.support now has a helper function to check for
     availability of a hash digest function.  Several tests are
     refactored avoid MD5 and use SHA256 instead.  Other tests are
     marked to use MD5 and skipped when MD5 is disabled.

   - bpo-37123(11): Multiprocessing test test_mymanager() now also
     expects -SIGTERM, not only exitcode 0.
     BaseManager._finalize_manager() sends SIGTERM to the manager
     process if it takes longer than 1 second to stop, which happens on
     slow buildbots.

   - bpo-38212(12): Multiprocessing tests: increase
     test_queue_feeder_donot_stop_onexc() timeout from 1 to 60 seconds.

   - bpo-38117(13): Test with OpenSSL 1.1.1d

   - bpo-38018(14): Increase code coverage for
     multiprocessing.shared_memory.

   - bpo-37805(15): Add tests for json.dump(…, skipkeys=True).  Patch by
     Donghee Na.

   - bpo-37531(16): Enhance regrtest multiprocess timeout: write a
     message when killing a worker process, catch popen.kill() and
     popen.wait() exceptions, put a timeout on the second call to
     popen.communicate().

   - bpo-37876(17): Add tests for ROT-13 codec.

   - bpo-36833(18): Added tests for ‘PyDateTime_XXX_GET_XXX()’ macros of
     the C API of the *note datetime: 34. module.  Patch by Joannah
     Nanjekye.

   - bpo-37558(19): Fix
     test_shared_memory_cleaned_after_process_termination name handling

   - bpo-37526(20): Add ‘test.support.catch_threading_exception()’:
     context manager catching *note threading.Thread: 176. exception
     using *note threading.excepthook(): a4d.

   - bpo-37421(21): test_concurrent_futures now explicitly stops the
     ForkServer instance if it’s running.

   - bpo-37421(22): multiprocessing tests now stop the ForkServer
     instance if it’s running: close the «alive» file descriptor to ask
     the server to stop and then remove its UNIX address.

   - bpo-37421(23): test_distutils.test_build_ext() is now able to
     remove the temporary directory on Windows: don’t import the newly
     built C extension («xx») in the current process, but test it in a
     separated process.

   - bpo-37421(24): test_concurrent_futures now cleans up
     multiprocessing to remove immediately temporary directories created
     by multiprocessing.util.get_temp_dir().

   - bpo-37421(25): test_winconsoleio doesn’t leak a temporary file
     anymore: use tempfile.TemporaryFile() to remove it when the test
     completes.

   - bpo-37421(26): multiprocessing tests now explicitly call
     ‘_run_finalizers()’ to immediately remove temporary directories
     created by tests.

   - bpo-37421(27): urllib.request tests now call *note urlcleanup():
     1da4. to remove temporary files created by ‘urlretrieve()’ tests
     and to clear the ‘_opener’ global variable set by ‘urlopen()’ and
     functions calling indirectly ‘urlopen()’.

   - bpo-37472(28): Remove ‘Lib/test/outstanding_bugs.py’.

   - bpo-37199(29): Fix test failures when IPv6 is unavailable or
     disabled.

   - bpo-19696(30): Replace deprecated method «random.choose» with
     «random.choice» in «test_pkg_import.py».

   - bpo-37335(31): Remove no longer necessary code from c locale
     coercion tests

   - bpo-37421(32): Fix test_shutil to no longer leak temporary files.

   - bpo-37411(33): Fix test_wsgiref.testEnviron() to no longer depend
     on the environment variables (don’t fail if «X» variable is set).

   - bpo-37400(34): Fix test_os.test_chown(): use os.getgroups() rather
     than grp.getgrall() to get groups.  Rename also the test to
     test_chown_gid().

   - bpo-37359(35): Add –cleanup option to python3 -m test to remove
     ‘test_python_*’ directories of previous failed jobs.  Add «make
     cleantest» to run ‘python3 -m test --cleanup’.

   - bpo-37362(36): test_gdb no longer fails if it gets an «unexpected»
     message on stderr: it now ignores stderr.  The purpose of test_gdb
     is to test that python-gdb.py commands work as expected, not to
     test gdb.

   - bpo-35998(37): Avoid TimeoutError in test_asyncio:
     test_start_tls_server_1()

   - bpo-37278(38): Fix test_asyncio ProactorLoopCtrlC: join the thread
     to prevent leaking a running thread and leaking a reference.

   - bpo-37261(39): Fix *note test.support.catch_unraisable_exception():
     1da5.: its __exit__() method now ignores unraisable exception
     raised when clearing its ‘unraisable’ attribute.

   - bpo-37069(40): regrtest now uses *note sys.unraisablehook(): 508.
     to mark a test as «environment altered» (ENV_CHANGED) if it emits
     an «unraisable exception».  Moreover, regrtest logs a warning in
     this case.

     Use ‘python3 -m test --fail-env-changed’ to catch unraisable
     exceptions in tests.

   - bpo-37252(41): Fix assertions in ‘test_close’ and
     ‘test_events_mask_overflow’ devpoll tests.

   - bpo-37169(42): Rewrite ‘_PyObject_IsFreed()’ unit tests.

   - bpo-37153(43): ‘test_venv.test_multiprocessing()’ now explicitly
     calls ‘pool.terminate()’ to wait until the pool completes.

   - bpo-34001(44): Make test_ssl pass with LibreSSL. LibreSSL handles
     minimum and maximum TLS version differently than OpenSSL.

   - bpo-36919(45): Make ‘test_source_encoding.test_issue2301’
     implementation independent.  The test will work now for both
     CPython and IronPython.

   - bpo-30202(46): Update ‘test.test_importlib.test_abc’ to test
     ‘find_spec()’.

   - bpo-28009(47): Modify the test_uuid logic to test when a program is
     available AND can be used to obtain a MACADDR as basis for an UUID.
     Patch by M. Felt

   - bpo-34596(48): Fallback to a default reason when *note
     unittest.skip(): 1da6. is uncalled.  Patch by Naitree Zhu.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38614

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38614

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38502

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35998

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38470

   (6) https://bugs.python.org/issue?@action=redirect&bpo=37531

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38239

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38275

   (9) https://bugs.python.org/issue?@action=redirect&bpo=38271

   (10) https://bugs.python.org/issue?@action=redirect&bpo=38270

   (11) https://bugs.python.org/issue?@action=redirect&bpo=37123

   (12) https://bugs.python.org/issue?@action=redirect&bpo=38212

   (13) https://bugs.python.org/issue?@action=redirect&bpo=38117

   (14) https://bugs.python.org/issue?@action=redirect&bpo=38018

   (15) https://bugs.python.org/issue?@action=redirect&bpo=37805

   (16) https://bugs.python.org/issue?@action=redirect&bpo=37531

   (17) https://bugs.python.org/issue?@action=redirect&bpo=37876

   (18) https://bugs.python.org/issue?@action=redirect&bpo=36833

   (19) https://bugs.python.org/issue?@action=redirect&bpo=37558

   (20) https://bugs.python.org/issue?@action=redirect&bpo=37526

   (21) https://bugs.python.org/issue?@action=redirect&bpo=37421

   (22) https://bugs.python.org/issue?@action=redirect&bpo=37421

   (23) https://bugs.python.org/issue?@action=redirect&bpo=37421

   (24) https://bugs.python.org/issue?@action=redirect&bpo=37421

   (25) https://bugs.python.org/issue?@action=redirect&bpo=37421

   (26) https://bugs.python.org/issue?@action=redirect&bpo=37421

   (27) https://bugs.python.org/issue?@action=redirect&bpo=37421

   (28) https://bugs.python.org/issue?@action=redirect&bpo=37472

   (29) https://bugs.python.org/issue?@action=redirect&bpo=37199

   (30) https://bugs.python.org/issue?@action=redirect&bpo=19696

   (31) https://bugs.python.org/issue?@action=redirect&bpo=37335

   (32) https://bugs.python.org/issue?@action=redirect&bpo=37421

   (33) https://bugs.python.org/issue?@action=redirect&bpo=37411

   (34) https://bugs.python.org/issue?@action=redirect&bpo=37400

   (35) https://bugs.python.org/issue?@action=redirect&bpo=37359

   (36) https://bugs.python.org/issue?@action=redirect&bpo=37362

   (37) https://bugs.python.org/issue?@action=redirect&bpo=35998

   (38) https://bugs.python.org/issue?@action=redirect&bpo=37278

   (39) https://bugs.python.org/issue?@action=redirect&bpo=37261

   (40) https://bugs.python.org/issue?@action=redirect&bpo=37069

   (41) https://bugs.python.org/issue?@action=redirect&bpo=37252

   (42) https://bugs.python.org/issue?@action=redirect&bpo=37169

   (43) https://bugs.python.org/issue?@action=redirect&bpo=37153

   (44) https://bugs.python.org/issue?@action=redirect&bpo=34001

   (45) https://bugs.python.org/issue?@action=redirect&bpo=36919

   (46) https://bugs.python.org/issue?@action=redirect&bpo=30202

   (47) https://bugs.python.org/issue?@action=redirect&bpo=28009

   (48) https://bugs.python.org/issue?@action=redirect&bpo=34596


File: python.info,  Node: Build<57>,  Next: Windows<49>,  Prev: Tests<49>,  Up: Python 3 9 0 alpha 1

1.24.56.6 Build
...............

   - bpo-38809(1): On Windows, build scripts will now recognize and use
     python.exe from an active virtual env.

   - bpo-38684(2): Fix _hashlib build when Blake2 is disabled, but
     OpenSSL supports it.

   - bpo-38468(3): Misc/python-config.in now uses ‘getvar()’ for all
     still existing ‘sysconfig.get_config_var()’ calls.  Patch by
     Joannah Nanjekye.

   - bpo-37415(4): Fix stdatomic.h header check for ICC compiler: the
     ICC implementation lacks atomic_uintptr_t type which is needed by
     Python.

   - bpo-38301(5): In Solaris family, we must be sure to use
     ‘-D_REENTRANT’.  Patch by Jesús Cea Avión.

   - bpo-36002(6): Locate ‘llvm-profdata’ and ‘llvm-ar’ binaries using
     ‘AC_PATH_TOOL’ rather than ‘AC_PATH_TARGET_TOOL’.

   - bpo-37936(7): The ‘.gitignore’ file systematically keeps «rooted»,
     with a non-trailing slash, all the rules that are meant to apply to
     files in a specific place in the repo.  Previously, when the
     intended file to ignore happened to be at the root of the repo,
     we’d most often accidentally also ignore files and directories with
     the same name anywhere in the tree.

   - bpo-37760(8): The ‘Tools/unicode/makeunicodedata.py’ script, which
     is used for converting information from the Unicode Character
     Database into generated code and data used by the methods of *note
     str: 169. and by the *note unicodedata: 10b. module, now handles
     each character’s data as a ‘dataclass’ with named attributes,
     rather than a length-18 list of different fields.

   - bpo-37936(9): The ‘.gitignore’ file no longer applies to any files
     that are in fact tracked in the Git repository.  Patch by Greg
     Price.

   - bpo-37725(10): Change «clean» makefile target to also clean the
     program guided optimization (PGO) data.  Previously you would have
     to use «make clean» and «make profile-removal», or «make clobber».

   - bpo-37707(11): Mark some individual tests to skip when –pgo is
     used.  The tests marked increase the PGO task time significantly
     and likely don’t help improve optimization of the final executable.

   - bpo-36044(12): Reduce the number of unit tests run for the PGO
     generation task.  This speeds up the task by a factor of about 15x.
     Running the full unit test suite is slow.  This change may result
     in a slightly less optimized build since not as many code branches
     will be executed.  If you are willing to wait for the much slower
     build, the old behavior can be restored using “./configure [..]
     PROFILE_TASK=»-m test –pgo-extended»”.  We make no guarantees as to
     which PGO task set produces a faster build.  Users who care should
     run their own relevant benchmarks as results can depend on the
     environment, workload, and compiler tool chain.

   - bpo-37468(13): ‘make install’ no longer installs ‘wininst-*.exe’
     files used by distutils bdist_wininst: bdist_wininst only works on
     Windows.

   - bpo-37189(14): Many ‘PyRun_XXX()’ functions like *note
     PyRun_String(): 1da8. were no longer exported in ‘libpython38.dll’
     by mistake.  Export them again to fix the ABI compatibility.

   - bpo-25361(15): Enables use of SSE2 instructions in Windows 32-bit
     build.

   - bpo-36210(16): Update optional extension module detection for AIX.
     ossaudiodev and spwd are not applicable for AIX, and are no longer
     reported as missing.  3rd-party packaging of ncurses (with ASIS
     support) conflicts with officially supported AIX curses library, so
     configure AIX to use libcurses.a.  However, skip trying to build
     _curses_panel.

     patch by M Felt

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38809

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38684

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38468

   (4) https://bugs.python.org/issue?@action=redirect&bpo=37415

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38301

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36002

   (7) https://bugs.python.org/issue?@action=redirect&bpo=37936

   (8) https://bugs.python.org/issue?@action=redirect&bpo=37760

   (9) https://bugs.python.org/issue?@action=redirect&bpo=37936

   (10) https://bugs.python.org/issue?@action=redirect&bpo=37725

   (11) https://bugs.python.org/issue?@action=redirect&bpo=37707

   (12) https://bugs.python.org/issue?@action=redirect&bpo=36044

   (13) https://bugs.python.org/issue?@action=redirect&bpo=37468

   (14) https://bugs.python.org/issue?@action=redirect&bpo=37189

   (15) https://bugs.python.org/issue?@action=redirect&bpo=25361

   (16) https://bugs.python.org/issue?@action=redirect&bpo=36210


File: python.info,  Node: Windows<49>,  Next: macOS<38>,  Prev: Build<57>,  Up: Python 3 9 0 alpha 1

1.24.56.7 Windows
.................

   - bpo-38589(1): Fixes HTML Help shortcut when Windows is not
     installed to C drive

   - bpo-38453(2): Ensure ntpath.realpath() correctly resolves relative
     paths.

   - bpo-38519(3): Restores the internal C headers that were missing
     from the nuget.org and Microsoft Store packages.

   - bpo-38492(4): Remove ‘pythonw.exe’ dependency on the Microsoft C++
     runtime.

   - bpo-38344(5): Fix error message in activate.bat

   - bpo-38359(6): Ensures ‘pyw.exe’ launcher reads correct registry
     key.

   - bpo-38355(7): Fixes ‘ntpath.realpath’ failing on ‘sys.executable’.

   - bpo-38117(8): Update bundled OpenSSL to 1.1.1d

   - bpo-38092(9): Reduce overhead when using multiprocessing in a
     Windows virtual environment.

   - bpo-38133(10): Allow py.exe launcher to locate installations from
     the Microsoft Store and improve display of active virtual
     environments.

   - bpo-38114(11): The ‘pip.ini’ is no longer included in the Nuget
     package.

   - bpo-32592(12): Set Windows 8 as the minimum required version for
     API support

   - bpo-36634(13): *note os.cpu_count(): 4dc. now returns active
     processors rather than maximum processors.

   - bpo-36634(14): venv activate.bat now works when the existing
     variables contain double quote characters.

   - bpo-38081(15): Prevent error calling *note os.path.realpath(): 262.
     on ‘'NUL'’.

   - bpo-38087(16): Fix case sensitivity in test_pathlib and
     test_ntpath.

   - bpo-38088(17): Fixes distutils not finding vcruntime140.dll with
     only the v142 toolset installed.

   - bpo-37283(18): Ensure command-line and unattend.xml setting
     override previously detected states in Windows installer.

   - bpo-38030(19): Fixes *note os.stat(): 26d. failing for block
     devices on Windows

   - bpo-38020(20): Fixes potential crash when calling *note
     os.readlink(): b1c. (or indirectly through *note realpath(): 262.)
     on a file that is not a supported link.

   - bpo-37705(21): Improve the implementation of ‘winerror_to_errno()’.

   - bpo-37549(22): *note os.dup(): 1daa. no longer fails for standard
     streams on Windows 7.

   - bpo-1311(23): The ‘nul’ file on Windows now returns True from *note
     exists(): c05. and a valid result from *note os.stat(): 26d. with
     ‘S_IFCHR’ set.

   - bpo-9949(24): Enable support for following symlinks in
     ‘os.realpath()’.

   - bpo-37834(25): Treat all name surrogate reparse points on Windows
     in *note os.lstat(): 6c9. and other reparse points as regular files
     in *note os.stat(): 26d.

   - bpo-36266(26): Add the module name in the formatted error message
     when DLL load fail happens during module import in
     ‘_PyImport_FindSharedFuncptrWindows()’.  Patch by Srinivas
     Nyayapati.

   - bpo-25172(27): Trying to import the ‘crypt’ module on Windows will
     result in an *note ImportError: 65b. with a message explaining that
     the module isn’t supported on Windows.  On other platforms, if the
     underlying ‘_crypt’ module is not available, the ImportError will
     include a message explaining the problem.

   - bpo-37778(28): Fixes the icons used for file associations to the
     Microsoft Store package.

   - bpo-37734(29): Fix use of registry values to launch Python from
     Microsoft Store app.

   - bpo-37702(30): Fix memory leak on Windows in creating an SSLContext
     object or running ‘urllib.request.urlopen('https://...')’.

   - bpo-37672(31): Switch Windows Store package’s pip to use bundled
     ‘pip.ini’ instead of ‘PIP_USER’ variable.

   - bpo-10945(32): Officially drop support for creating bdist_wininst
     installers on non-Windows systems.

   - bpo-37445(33): Include the ‘FORMAT_MESSAGE_IGNORE_INSERTS’ flag in
     ‘FormatMessageW()’ calls.

   - bpo-37369(34): Fixes path for *note sys.executable: 3ed. when
     running from the Microsoft Store.

   - bpo-37380(35): Don’t collect unfinished processes with
     ‘subprocess._active’ on Windows to cleanup later.  Patch by Ruslan
     Kuprieiev.

   - bpo-37351(36): Removes libpython38.a from standard Windows
     distribution.

   - bpo-35360(37): Update Windows builds to use SQLite 3.28.0.

   - bpo-37267(38): On Windows, *note os.dup(): 1daa. no longer creates
     an inheritable fd when handling a character file.

   - bpo-36779(39): Ensure ‘time.tzname’ is correct on Windows when the
     active code page is set to CP_UTF7 or CP_UTF8.

   - bpo-32587(40): Make *note winreg.REG_MULTI_SZ: 1dab. support
     zero-length strings.

   - bpo-28269(41): Replace use of ‘strcasecmp()’ for the system
     function ‘_stricmp()’.  Patch by Minmin Gong.

   - bpo-36590(42): Add native Bluetooth RFCOMM support to socket
     module.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38589

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38453

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38519

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38492

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38344

   (6) https://bugs.python.org/issue?@action=redirect&bpo=38359

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38355

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38117

   (9) https://bugs.python.org/issue?@action=redirect&bpo=38092

   (10) https://bugs.python.org/issue?@action=redirect&bpo=38133

   (11) https://bugs.python.org/issue?@action=redirect&bpo=38114

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32592

   (13) https://bugs.python.org/issue?@action=redirect&bpo=36634

   (14) https://bugs.python.org/issue?@action=redirect&bpo=36634

   (15) https://bugs.python.org/issue?@action=redirect&bpo=38081

   (16) https://bugs.python.org/issue?@action=redirect&bpo=38087

   (17) https://bugs.python.org/issue?@action=redirect&bpo=38088

   (18) https://bugs.python.org/issue?@action=redirect&bpo=37283

   (19) https://bugs.python.org/issue?@action=redirect&bpo=38030

   (20) https://bugs.python.org/issue?@action=redirect&bpo=38020

   (21) https://bugs.python.org/issue?@action=redirect&bpo=37705

   (22) https://bugs.python.org/issue?@action=redirect&bpo=37549

   (23) https://bugs.python.org/issue?@action=redirect&bpo=1311

   (24) https://bugs.python.org/issue?@action=redirect&bpo=9949

   (25) https://bugs.python.org/issue?@action=redirect&bpo=37834

   (26) https://bugs.python.org/issue?@action=redirect&bpo=36266

   (27) https://bugs.python.org/issue?@action=redirect&bpo=25172

   (28) https://bugs.python.org/issue?@action=redirect&bpo=37778

   (29) https://bugs.python.org/issue?@action=redirect&bpo=37734

   (30) https://bugs.python.org/issue?@action=redirect&bpo=37702

   (31) https://bugs.python.org/issue?@action=redirect&bpo=37672

   (32) https://bugs.python.org/issue?@action=redirect&bpo=10945

   (33) https://bugs.python.org/issue?@action=redirect&bpo=37445

   (34) https://bugs.python.org/issue?@action=redirect&bpo=37369

   (35) https://bugs.python.org/issue?@action=redirect&bpo=37380

   (36) https://bugs.python.org/issue?@action=redirect&bpo=37351

   (37) https://bugs.python.org/issue?@action=redirect&bpo=35360

   (38) https://bugs.python.org/issue?@action=redirect&bpo=37267

   (39) https://bugs.python.org/issue?@action=redirect&bpo=36779

   (40) https://bugs.python.org/issue?@action=redirect&bpo=32587

   (41) https://bugs.python.org/issue?@action=redirect&bpo=28269

   (42) https://bugs.python.org/issue?@action=redirect&bpo=36590


File: python.info,  Node: macOS<38>,  Next: IDLE<32>,  Prev: Windows<49>,  Up: Python 3 9 0 alpha 1

1.24.56.8 macOS
...............

   - bpo-38117(1): Updated OpenSSL to 1.1.1d in macOS installer.

   - bpo-38089(2): Move Azure Pipelines to latest VM versions and make
     macOS tests optional

   - bpo-18049(3): Increase the default stack size of threads from 5MB
     to 16MB on macOS, to match the stack size of the main thread.  This
     avoids crashes on deep recursion in threads.

   - bpo-34602(4): Avoid test suite failures on macOS by no longer
     calling resource.setrlimit to increase the process stack size limit
     at runtime.  The runtime change is no longer needed since the
     interpreter is being built with a larger default stack size.

   - bpo-35360(5): Update macOS installer to use SQLite 3.28.0.

   - bpo-34631(6): Updated OpenSSL to 1.1.1c in macOS installer.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38117

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38089

   (3) https://bugs.python.org/issue?@action=redirect&bpo=18049

   (4) https://bugs.python.org/issue?@action=redirect&bpo=34602

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35360

   (6) https://bugs.python.org/issue?@action=redirect&bpo=34631


File: python.info,  Node: IDLE<32>,  Next: Tools/Demos<33>,  Prev: macOS<38>,  Up: Python 3 9 0 alpha 1

1.24.56.9 IDLE
..............

   - bpo-26353(1): Stop adding newline when saving an IDLE shell window.

   - bpo-4630(2): Add an option to toggle IDLE’s cursor blink for shell,
     editor, and output windows.  See Settings, General, Window
     Preferences, Cursor Blink.  Patch by Zackery Spytz.

   - bpo-38598(3): Do not try to compile IDLE shell or output windows

   - bpo-36698(4): IDLE no longer fails when write non-encodable
     characters to stderr.  It now escapes them with a backslash, as the
     regular Python interpreter.  Added the ‘errors’ field to the
     standard streams.

   - bpo-35379(5): When exiting IDLE, catch any AttributeError.  One
     happens when EditorWindow.close is called twice.  Printing a
     traceback, when IDLE is run from a terminal, is useless and
     annoying.

   - bpo-38183(6): To avoid problems, test_idle ignores the user config
     directory.  It no longer tries to create or access .idlerc or any
     files within.  Users must run IDLE to discover problems with saving
     settings.

   - bpo-38077(7): IDLE no longer adds “argv” to the user namespace when
     initializing it.  This bug only affected 3.7.4 and 3.8.0b2 to
     3.8.0b4.

   - bpo-38041(8): Shell restart lines now fill the window width, always
     start with “=”, and avoid wrapping unnecessarily.  The line will
     still wrap if the included file name is long relative to the width.

   - bpo-35771(9): To avoid occasional spurious test_idle failures on
     slower machines, increase the ‘hover_delay’ in test_tooltip.

   - bpo-37824(10): Properly handle user input warnings in IDLE shell.
     Cease turning SyntaxWarnings into SyntaxErrors.

   - bpo-37929(11): IDLE Settings dialog now closes properly when there
     is no shell window.

   - bpo-37902(12): Add mousewheel scrolling for IDLE module, path, and
     stack browsers.  Patch by George Zhang.

   - bpo-37849(13): Fixed completions list appearing too high or low
     when shown above the current line.

   - bpo-36419(14): Refactor IDLE autocomplete and improve testing.

   - bpo-37748(15): Reorder the Run menu.  Put the most common choice,
     Run Module, at the top.

   - bpo-37692(16): Improve highlight config sample with example shell
     interaction and better labels for shell elements.

   - bpo-37628(17): Settings dialog no longer expands with font size.

   - bpo-37627(18): Initialize the Customize Run dialog with the command
     line arguments most recently entered before.  The user can
     optionally edit before submitting them.

   - bpo-33610(19): Fix code context not showing the correct context
     when first toggled on.

   - bpo-37530(20): Optimize code context to reduce unneeded background
     activity.  Font and highlight changes now occur along with text
     changes instead of after a random delay.

   - bpo-27452(21): Cleanup ‘config.py’ by inlining ‘RemoveFile’ and
     simplifying the handling of ‘file’ in ‘CreateConfigHandlers’.

   - bpo-37325(22): Fix tab focus traversal order for help source and
     custom run dialogs.

   - bpo-37321(23): Both subprocess connection error messages now refer
     to the “Startup failure” section of the IDLE doc.

   - bpo-17535(24): Add optional line numbers for IDLE editor windows.
     Windows open without line numbers unless set otherwise in the
     General tab of the configuration dialog.

   - bpo-26806(25): To compensate for stack frames added by IDLE and
     avoid possible problems with low recursion limits, add 30 to limits
     in the user code execution process.  Subtract 30 when reporting
     recursion limits to make this addition mostly transparent.

   - bpo-37177(26): Properly “attach” search dialogs to their main
     window so that they behave like other dialogs and do not get hidden
     behind their main window.

   - bpo-37039(27): Adjust «Zoom Height» to individual screens by
     momentarily maximizing the window on first use with a particular
     screen.  Changing screen settings may invalidate the saved height.
     While a window is maximized, «Zoom Height» has no effect.

   - bpo-35763(28): Make calltip reminder about “/” meaning
     positional-only less obtrusive by only adding it when there is room
     on the first line.

   - bpo-5680(29): Add “Run… Customized” to the Run menu to run a module
     with customized settings.  Any “command line arguments” entered are
     added to sys.argv.  One can suppress the normal Shell main module
     restart.

   - bpo-36390(30): Gather Format menu functions into format.py.
     Combine paragraph.py, rstrip.py, and format methods from editor.py.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26353

   (2) https://bugs.python.org/issue?@action=redirect&bpo=4630

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38598

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36698

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35379

   (6) https://bugs.python.org/issue?@action=redirect&bpo=38183

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38077

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38041

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35771

   (10) https://bugs.python.org/issue?@action=redirect&bpo=37824

   (11) https://bugs.python.org/issue?@action=redirect&bpo=37929

   (12) https://bugs.python.org/issue?@action=redirect&bpo=37902

   (13) https://bugs.python.org/issue?@action=redirect&bpo=37849

   (14) https://bugs.python.org/issue?@action=redirect&bpo=36419

   (15) https://bugs.python.org/issue?@action=redirect&bpo=37748

   (16) https://bugs.python.org/issue?@action=redirect&bpo=37692

   (17) https://bugs.python.org/issue?@action=redirect&bpo=37628

   (18) https://bugs.python.org/issue?@action=redirect&bpo=37627

   (19) https://bugs.python.org/issue?@action=redirect&bpo=33610

   (20) https://bugs.python.org/issue?@action=redirect&bpo=37530

   (21) https://bugs.python.org/issue?@action=redirect&bpo=27452

   (22) https://bugs.python.org/issue?@action=redirect&bpo=37325

   (23) https://bugs.python.org/issue?@action=redirect&bpo=37321

   (24) https://bugs.python.org/issue?@action=redirect&bpo=17535

   (25) https://bugs.python.org/issue?@action=redirect&bpo=26806

   (26) https://bugs.python.org/issue?@action=redirect&bpo=37177

   (27) https://bugs.python.org/issue?@action=redirect&bpo=37039

   (28) https://bugs.python.org/issue?@action=redirect&bpo=35763

   (29) https://bugs.python.org/issue?@action=redirect&bpo=5680

   (30) https://bugs.python.org/issue?@action=redirect&bpo=36390


File: python.info,  Node: Tools/Demos<33>,  Next: C API<52>,  Prev: IDLE<32>,  Up: Python 3 9 0 alpha 1

1.24.56.10 Tools/Demos
......................

   - bpo-38118(1): Update Valgrind suppression file to ignore a false
     alarm in *note PyUnicode_Decode(): 1daf. when using GCC builtin
     strcmp().

   - bpo-38347(2): pathfix.py: Assume all files that end on “.py” are
     Python scripts when working recursively.

   - bpo-37803(3): pdb’s ‘--help’ and ‘--version’ long options now work.

   - bpo-37942(4): Improve ArgumentClinic converter for floats.

   - bpo-37704(5): Remove ‘Tools/scripts/h2py.py’: use cffi to access a
     C API in Python.

   - bpo-37675(6): 2to3 now works when run from a zipped standard
     library.

   - bpo-37034(7): Argument Clinic now uses the argument name on errors
     with keyword-only argument instead of their position.  Patch
     contributed by Rémi Lapeyre.

   - bpo-37064(8): Add option -k to pathscript.py script: preserve
     shebang flags.  Add option -a to pathscript.py script: add flags.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=38118

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38347

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37803

   (4) https://bugs.python.org/issue?@action=redirect&bpo=37942

   (5) https://bugs.python.org/issue?@action=redirect&bpo=37704

   (6) https://bugs.python.org/issue?@action=redirect&bpo=37675

   (7) https://bugs.python.org/issue?@action=redirect&bpo=37034

   (8) https://bugs.python.org/issue?@action=redirect&bpo=37064


File: python.info,  Node: C API<52>,  Prev: Tools/Demos<33>,  Up: Python 3 9 0 alpha 1

1.24.56.11 C API
................

   - bpo-37633(1): Re-export some function compatibility wrappers for
     macros in ‘pythonrun.h’.

   - bpo-38644(2): Provide *note Py_EnterRecursiveCall(): 3d2. and *note
     Py_LeaveRecursiveCall(): b6d. as regular functions for the limited
     API. Previously, there were defined as macros, but these macros
     didn’t work with the limited API which cannot access
     ‘PyThreadState.recursion_depth’ field.  Remove
     ‘_Py_CheckRecursionLimit’ from the stable ABI.

   - bpo-38650(3): The global variable *note
     PyStructSequence_UnnamedField: b7b. is now a constant and refers to
     a constant string.

   - bpo-38540(4): Fixed possible leak in *note PyArg_Parse(): 17f6. and
     similar functions for format units ‘"es#"’ and ‘"et#"’ when the
     macro ‘PY_SSIZE_T_CLEAN’ is not defined.

   - bpo-38395(5): Fix a crash in *note weakref.proxy: c48. objects due
     to incorrect lifetime management when calling some associated
     methods that may delete the last reference to object being
     referenced by the proxy.  Patch by Pablo Galindo.

   - bpo-36389(6): The ‘_PyObject_CheckConsistency()’ function is now
     also available in release mode.  For example, it can be used to
     debug a crash in the ‘visit_decref()’ function of the GC.

   - bpo-38266(7): Revert the removal of PyThreadState_DeleteCurrent()
     with documentation.

   - bpo-38303(8): Update audioop extension module to use the stable ABI
     (PEP-384).  Patch by Tyler Kieft.

   - bpo-38234(9): ‘Py_SetPath()’ now sets *note sys.executable: 3ed. to
     the program full path (*note Py_GetProgramFullPath(): 3ec.) rather
     than to the program name (*note Py_GetProgramName(): 3ee.).

   - bpo-38234(10): Python ignored arguments passed to ‘Py_SetPath()’,
     ‘Py_SetPythonHome()’ and ‘Py_SetProgramName()’: fix Python
     initialization to use specified arguments.

   - bpo-38205(11): The *note Py_UNREACHABLE(): db0. macro now calls
     *note Py_FatalError(): b7c.

   - bpo-38140(12): Make dict and weakref offsets opaque for C heap
     types by passing the offsets through PyMemberDef

   - bpo-15088(13): The C function ‘PyGen_NeedsFinalizing’ has been
     removed.  It was not documented, tested or used anywhere within
     CPython after the implementation of PEP 442(14).  Patch by Joannah
     Nanjekye.  (Patch by Joannah Nanjekye)

   - bpo-36763(15): Options added by ‘PySys_AddXOption()’ are now
     handled the same way than ‘PyConfig.xoptions’ and command line ‘-X’
     options.

   - bpo-37926(16): Fix a crash in ‘PySys_SetArgvEx(0, NULL, 0)’.

   - bpo-37879(17): Fix subtype_dealloc to suppress the type decref when
     the base type is a C heap type

   - bpo-37645(18): Add ‘_PyObject_FunctionStr()’ to get a user-friendly
     string representation of a function-like object.  Patch by Jeroen
     Demeyer.

   - bpo-29548(19): The functions ‘PyEval_CallObject’,
     ‘PyEval_CallFunction’, ‘PyEval_CallMethod’ and
     ‘PyEval_CallObjectWithKeywords’ are deprecated.  Use *note
     PyObject_Call(): 63d. and its variants instead.

   - bpo-37151(20): ‘PyCFunction_Call’ is now a deprecated alias of
     *note PyObject_Call(): 63d.

   - bpo-37540(21): The vectorcall protocol now requires that the caller
     passes only strings as keyword names.

   - bpo-37207(22): The vectorcall protocol is now enabled for ‘type’
     objects: set ‘tp_vectorcall’ to a vectorcall function to be used
     instead of ‘tp_new’ and ‘tp_init’ when calling the class itself.

   - bpo-21120(23): Exclude Python-ast.h, ast.h and asdl.h from the
     limited API.

   - bpo-37483(24): Add new function ‘_PyObject_CallOneArg’ for calling
     an object with one positional argument.

   - bpo-36763(25): Add *note PyConfig_SetWideStringList(): 1db1.
     function.

   - bpo-37337(26): Add fast functions for calling methods:
     ‘_PyObject_VectorcallMethod()’, ‘_PyObject_CallMethodNoArgs()’ and
     ‘_PyObject_CallMethodOneArg()’.

   - bpo-28805(27): The *note METH_FASTCALL: 1986. calling convention
     has been documented.

   - bpo-37221(28): The new function ‘PyCode_NewWithPosOnlyArgs()’
     allows to create code objects like ‘PyCode_New()’, but with an
     extra 'posonlyargcount' parameter for indicating the number of
     positonal-only arguments.

   - bpo-37215(29): Fix dtrace issue introduce by bpo-36842(30)

   - bpo-37194(31): Add a new public *note PyObject_CallNoArgs(): 63c.
     function to the C API: call a callable Python object without any
     arguments.  It is the most efficient way to call a callback without
     any argument.  On x86-64, for example,
     ‘PyObject_CallFunctionObjArgs(func, NULL)’ allocates 960 bytes on
     the stack per call, whereas ‘PyObject_CallNoArgs(func)’ only
     allocates 624 bytes per call.

   - bpo-37170(32): Fix the cast on error in *note
     PyLong_AsUnsignedLongLongMask(): 1db2.

   - bpo-35381(33): Convert posixmodule.c statically allocated types
     ‘DirEntryType’ and ‘ScandirIteratorType’ to heap-allocated types.

   - bpo-34331(34): Use singular/plural noun in error message when
     instantiating an abstract class with non-overridden abstract
     method(s).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37633

   (2) https://bugs.python.org/issue?@action=redirect&bpo=38644

   (3) https://bugs.python.org/issue?@action=redirect&bpo=38650

   (4) https://bugs.python.org/issue?@action=redirect&bpo=38540

   (5) https://bugs.python.org/issue?@action=redirect&bpo=38395

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36389

   (7) https://bugs.python.org/issue?@action=redirect&bpo=38266

   (8) https://bugs.python.org/issue?@action=redirect&bpo=38303

   (9) https://bugs.python.org/issue?@action=redirect&bpo=38234

   (10) https://bugs.python.org/issue?@action=redirect&bpo=38234

   (11) https://bugs.python.org/issue?@action=redirect&bpo=38205

   (12) https://bugs.python.org/issue?@action=redirect&bpo=38140

   (13) https://bugs.python.org/issue?@action=redirect&bpo=15088

   (14) https://peps.python.org/pep-0442/

   (15) https://bugs.python.org/issue?@action=redirect&bpo=36763

   (16) https://bugs.python.org/issue?@action=redirect&bpo=37926

   (17) https://bugs.python.org/issue?@action=redirect&bpo=37879

   (18) https://bugs.python.org/issue?@action=redirect&bpo=37645

   (19) https://bugs.python.org/issue?@action=redirect&bpo=29548

   (20) https://bugs.python.org/issue?@action=redirect&bpo=37151

   (21) https://bugs.python.org/issue?@action=redirect&bpo=37540

   (22) https://bugs.python.org/issue?@action=redirect&bpo=37207

   (23) https://bugs.python.org/issue?@action=redirect&bpo=21120

   (24) https://bugs.python.org/issue?@action=redirect&bpo=37483

   (25) https://bugs.python.org/issue?@action=redirect&bpo=36763

   (26) https://bugs.python.org/issue?@action=redirect&bpo=37337

   (27) https://bugs.python.org/issue?@action=redirect&bpo=28805

   (28) https://bugs.python.org/issue?@action=redirect&bpo=37221

   (29) https://bugs.python.org/issue?@action=redirect&bpo=37215

   (30) https://bugs.python.org/issue?@action=redirect&bpo=36842

   (31) https://bugs.python.org/issue?@action=redirect&bpo=37194

   (32) https://bugs.python.org/issue?@action=redirect&bpo=37170

   (33) https://bugs.python.org/issue?@action=redirect&bpo=35381

   (34) https://bugs.python.org/issue?@action=redirect&bpo=34331


File: python.info,  Node: Python 3 8 0 beta 1,  Next: Python 3 8 0 alpha 4,  Prev: Python 3 9 0 alpha 1,  Up: Changelog

1.24.57 Python 3.8.0 beta 1
---------------------------

'Release date: 2019-06-04'

* Menu:

* Security: Security<43>.
* Core and Builtins: Core and Builtins<154>.
* Library: Library<157>.
* Documentation: Documentation<51>.
* Tests: Tests<50>.
* Build: Build<58>.
* Windows: Windows<50>.
* macOS: macOS<39>.
* IDLE: IDLE<33>.
* Tools/Demos: Tools/Demos<34>.
* C API: C API<53>.


File: python.info,  Node: Security<43>,  Next: Core and Builtins<154>,  Up: Python 3 8 0 beta 1

1.24.57.1 Security
..................

   - bpo-35907(1): CVE 2019-9948(2): Avoid file reading by disallowing
     ‘local-file://’ and ‘local_file://’ URL schemes in
     ‘URLopener().open()’ and ‘URLopener().retrieve()’ of *note
     urllib.request: 111.

   - bpo-33529(3): Prevent fold function used in email header encoding
     from entering infinite loop when there are too many non-ASCII
     characters in a header.

   - bpo-33164(4): Updated blake2 implementation which uses secure
     memset implementation provided by platform.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35907

   (2) https://www.cve.org/CVERecord?id=CVE-2019-9948

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33529

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33164


File: python.info,  Node: Core and Builtins<154>,  Next: Library<157>,  Prev: Security<43>,  Up: Python 3 8 0 beta 1

1.24.57.2 Core and Builtins
...........................

   - bpo-35814(1): Allow unpacking in the right hand side of annotated
     assignments.  In particular, ‘t: Tuple[int, ...] = x, y, *z’ is now
     allowed.

   - bpo-37126(2): All structseq objects are now tracked by the garbage
     collector.  Patch by Pablo Galindo.

   - bpo-37122(3): Make the 'co_argcount' attribute of code objects
     represent the total number of positional arguments (including
     positional-only arguments).  The value of 'co_posonlyargcount' can
     be used to distinguish which arguments are positional only, and the
     difference ('co_argcount' - 'co_posonlyargcount') is the number of
     positional-or-keyword arguments.  Patch by Pablo Galindo.

   - bpo-20092(4): Constructors of *note int: 19b, *note float: 196. and
     *note complex: 197. will now use the *note __index__(): 19e.
     special method, if available and the corresponding method *note
     __int__(): 19d, *note __float__(): bc3. or *note __complex__():
     7fe. is not available.

   - bpo-37087(5): Add native thread ID (TID) support to OpenBSD.

   - bpo-26219(6): Implemented per opcode cache mechanism and
     ‘LOAD_GLOBAL’ instruction use it.  ‘LOAD_GLOBAL’ is now about 40%
     faster.  Contributed by Yury Selivanov, and Inada Naoki.

   - bpo-37072(7): Fix crash in PyAST_FromNodeObject() when flags is
     NULL.

   - bpo-37029(8): Freeing a great many small objects could take time
     quadratic in the number of arenas, due to using linear search to
     keep ‘obmalloc.c’’s list of usable arenas sorted by order of number
     of free memory pools.  This is accomplished without search now,
     leaving the worst-case time linear in the number of arenas.  For
     programs where this quite visibly matters (typically with more than
     100 thousand small objects alive simultaneously), this can greatly
     reduce the time needed to release their memory.

   - bpo-26423(9): Fix possible overflow in ‘wrap_lenfunc()’ when
     ‘sizeof(long) < sizeof(Py_ssize_t)’ (e.g., 64-bit Windows).

   - bpo-37050(10): Improve the AST for «debug» f-strings, which use “=”
     to print out the source of the expression being evaluated.  Delete
     expr_text from the FormattedValue node, and instead use a Constant
     string node (possibly merged with adjacent constant expressions
     inside the f-string).

   - bpo-22385(11): The ‘bytes.hex’, ‘bytearray.hex’, and
     ‘memoryview.hex’ methods as well as the ‘binascii.hexlify’ and
     ‘b2a_hex’ functions now have the ability to include an optional
     separator between hex bytes.  This functionality was inspired by
     MicroPython’s hexlify implementation.

   - bpo-26836(12): Add *note os.memfd_create(): c00.

   - bpo-37032(13): Added new ‘replace()’ method to the code type (*note
     types.CodeType: 32f.).

   - bpo-37007(14): Implement *note socket.if_nameindex(): c24, *note
     socket.if_nametoindex(): c25, and *note socket.if_indextoname():
     c26. on Windows.

   - bpo-36829(15): *note PyErr_WriteUnraisable(): 5f2. now creates a
     traceback object if there is no current traceback.  Moreover, call
     *note PyErr_NormalizeException(): 42a. and *note
     PyException_SetTraceback(): 1db6. to normalize the exception value.
     Ignore any error.

   - bpo-36878(16): Only accept text after ‘# type: ignore’ if the first
     character is ASCII. This is to disallow things like ‘# type:
     ignoreé’.

   - bpo-36878(17): Store text appearing after a ‘# type: ignore’
     comment in the AST. For example a type ignore like ‘# type:
     ignore[E1000]’ will have the string ‘"[E1000]"’ stored in its AST
     node.

   - bpo-2180(18): Treat line continuation at EOF as a ‘SyntaxError’ by
     Anthony Sottile.

   - bpo-36907(19): Fix a crash when calling a C function with a keyword
     dict (‘f(**kwargs)’) and changing the dict ‘kwargs’ while that
     function is running.

   - bpo-36946(20): Fix possible signed integer overflow when handling
     slices.

   - bpo-36826(21): Add NamedExpression kind support to ast_unparse.c

   - bpo-1875(22): A *note SyntaxError: 18e. is now raised if a code
     blocks that will be optimized away (e.g.  if conditions that are
     always false) contains syntax errors.  Patch by Pablo Galindo.

   - bpo-36027(23): Allow computation of modular inverses via
     three-argument ‘pow’: the second argument is now permitted to be
     negative in the case where the first and third arguments are
     relatively prime.

   - bpo-36861(24): Update the Unicode database to version 12.1.0.

   - bpo-28866(25): Avoid caching attributes of classes which type
     defines mro() to avoid a hard cache invalidation problem.

   - bpo-36851(26): The ‘FrameType’ stack is now correctly cleaned up if
     the execution ends with a return and the stack is not empty.

   - bpo-34616(27): The ‘compile()’ builtin functions now support the
     ‘ast.PyCF_ALLOW_TOP_LEVEL_AWAIT’ flag, which allow to compile
     sources that contains top-level ‘await’, ‘async with’ or ‘async
     for’.  This is useful to evaluate async-code from with an already
     async functions; for example in a custom REPL.

   - bpo-36842(28): Implement PEP 578, adding sys.audit, io.open_code
     and related APIs.

   - bpo-27639(29): Correct return type for UserList slicing operations.
     Patch by Michael Blahay, Erick Cervantes, and vaultah

   - bpo-36737(30): Move PyRuntimeState.warnings into per-interpreter
     state (via «module state»).

   - bpo-36793(31): Removed ‘__str__’ implementations from builtin types
     *note bool: 3c3, *note int: 19b, *note float: 196, *note complex:
     197. and few classes from the standard library.  They now inherit
     ‘__str__()’ from *note object: c80.

   - bpo-36817(32): Add a ‘=’ feature f-strings for debugging.  This can
     precede ‘!s’, ‘!r’, or ‘!a’.  It produces the text of the
     expression, followed by an equal sign, followed by the repr of the
     value of the expression.  So ‘f'{3*9+15=}'’ would be equal to the
     string ‘'3*9+15=42'’.  If ‘=’ is specified, the default conversion
     is set to ‘!r’, unless a format spec is given, in which case the
     formatting behavior is unchanged, and __format__ will be used.

   - bpo-24048(33): Save the live exception during import.c’s
     ‘remove_module()’.

   - bpo-27987(34): pymalloc returns memory blocks aligned by 16 bytes,
     instead of 8 bytes, on 64-bit platforms to conform x86-64 ABI.
     Recent compilers assume this alignment more often.  Patch by Inada
     Naoki.

   - bpo-36601(35): A long-since-meaningless check for ‘getpid() ==
     main_pid’ was removed from Python’s internal C signal handler.

   - bpo-36594(36): Fix incorrect use of ‘%p’ in format strings.  Patch
     by Zackery Spytz.

   - bpo-36045(37): ‘builtins.help()’ now prefixes ‘async’ for async
     functions.

   - bpo-36084(38): Add native thread ID (TID) to threading.Thread
     objects (supported platforms: Windows, FreeBSD, Linux, macOS)

   - bpo-36035(39): Added fix for broken symlinks in combination with
     pathlib

   - bpo-35983(40): Added new trashcan macros to deal with a double
     deallocation that could occur when the ‘tp_dealloc’ of a subclass
     calls the ‘tp_dealloc’ of a base class and that base class uses the
     trashcan mechanism.  Patch by Jeroen Demeyer.

   - bpo-20602(41): Do not clear *note sys.flags: 89d. and *note
     sys.float_info: 1db7. during shutdown.  Patch by Zackery Spytz.

   - bpo-26826(42): Expose ‘copy_file_range()’ as a low level API in the
     *note os: a5. module.

   - bpo-32388(43): Remove cross-version binary compatibility
     requirement in tp_flags.

   - bpo-31862(44): Port binascii to PEP 489 multiphase initialization.
     Patch by Marcel Plch.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35814

   (2) https://bugs.python.org/issue?@action=redirect&bpo=37126

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37122

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20092

   (5) https://bugs.python.org/issue?@action=redirect&bpo=37087

   (6) https://bugs.python.org/issue?@action=redirect&bpo=26219

   (7) https://bugs.python.org/issue?@action=redirect&bpo=37072

   (8) https://bugs.python.org/issue?@action=redirect&bpo=37029

   (9) https://bugs.python.org/issue?@action=redirect&bpo=26423

   (10) https://bugs.python.org/issue?@action=redirect&bpo=37050

   (11) https://bugs.python.org/issue?@action=redirect&bpo=22385

   (12) https://bugs.python.org/issue?@action=redirect&bpo=26836

   (13) https://bugs.python.org/issue?@action=redirect&bpo=37032

   (14) https://bugs.python.org/issue?@action=redirect&bpo=37007

   (15) https://bugs.python.org/issue?@action=redirect&bpo=36829

   (16) https://bugs.python.org/issue?@action=redirect&bpo=36878

   (17) https://bugs.python.org/issue?@action=redirect&bpo=36878

   (18) https://bugs.python.org/issue?@action=redirect&bpo=2180

   (19) https://bugs.python.org/issue?@action=redirect&bpo=36907

   (20) https://bugs.python.org/issue?@action=redirect&bpo=36946

   (21) https://bugs.python.org/issue?@action=redirect&bpo=36826

   (22) https://bugs.python.org/issue?@action=redirect&bpo=1875

   (23) https://bugs.python.org/issue?@action=redirect&bpo=36027

   (24) https://bugs.python.org/issue?@action=redirect&bpo=36861

   (25) https://bugs.python.org/issue?@action=redirect&bpo=28866

   (26) https://bugs.python.org/issue?@action=redirect&bpo=36851

   (27) https://bugs.python.org/issue?@action=redirect&bpo=34616

   (28) https://bugs.python.org/issue?@action=redirect&bpo=36842

   (29) https://bugs.python.org/issue?@action=redirect&bpo=27639

   (30) https://bugs.python.org/issue?@action=redirect&bpo=36737

   (31) https://bugs.python.org/issue?@action=redirect&bpo=36793

   (32) https://bugs.python.org/issue?@action=redirect&bpo=36817

   (33) https://bugs.python.org/issue?@action=redirect&bpo=24048

   (34) https://bugs.python.org/issue?@action=redirect&bpo=27987

   (35) https://bugs.python.org/issue?@action=redirect&bpo=36601

   (36) https://bugs.python.org/issue?@action=redirect&bpo=36594

   (37) https://bugs.python.org/issue?@action=redirect&bpo=36045

   (38) https://bugs.python.org/issue?@action=redirect&bpo=36084

   (39) https://bugs.python.org/issue?@action=redirect&bpo=36035

   (40) https://bugs.python.org/issue?@action=redirect&bpo=35983

   (41) https://bugs.python.org/issue?@action=redirect&bpo=20602

   (42) https://bugs.python.org/issue?@action=redirect&bpo=26826

   (43) https://bugs.python.org/issue?@action=redirect&bpo=32388

   (44) https://bugs.python.org/issue?@action=redirect&bpo=31862


File: python.info,  Node: Library<157>,  Next: Documentation<51>,  Prev: Core and Builtins<154>,  Up: Python 3 8 0 beta 1

1.24.57.3 Library
.................

   - bpo-37128(1): Added *note math.perm(): 8e1.

   - bpo-37120(2): Add SSLContext.num_tickets to control the number of
     TLSv1.3 session tickets.

   - bpo-12202(3): Fix the error handling in
     ‘msilib.SummaryInformation.GetProperty()’.  Patch by Zackery Spytz.

   - bpo-26835(4): The fcntl module now contains file sealing constants
     for sealing of memfds.

   - bpo-29262(5): Add ‘get_origin()’ and ‘get_args()’ introspection
     helpers to ‘typing’ module.

   - bpo-12639(6): ‘msilib.Directory.start_component()’ no longer fails
     if 'keyfile' is not ‘None’.

   - bpo-36999(7): Add the ‘asyncio.Task.get_coro()’ method to publicly
     expose the tasks’s coroutine object.

   - bpo-35246(8): Make *note asyncio.create_subprocess_exec(): c6d.
     accept path-like arguments.

   - bpo-35279(9): Change default 'max_workers' of ‘ThreadPoolExecutor’
     from ‘cpu_count() * 5’ to ‘min(32, cpu_count() + 4)’.  Previous
     value was unreasonably large on many cores machines.

   - bpo-37076(10): *note _thread.start_new_thread(): 4b5. now logs
     uncaught exception raised by the function using *note
     sys.unraisablehook(): 508, rather than *note sys.excepthook(): a0e,
     so the hook gets access to the function which raised the exception.

   - bpo-33725(11): On macOS, the *note multiprocessing: 98. module now
     uses 'spawn' start method by default.

   - bpo-37054(12): Fix destructor ‘_pyio.BytesIO’ and
     ‘_pyio.TextIOWrapper’: initialize their ‘_buffer’ attribute as soon
     as possible (in the class body), because it’s used by ‘__del__()’
     which calls ‘close()’.

   - bpo-37058(13): PEP 544: Add ‘Protocol’ and ‘@runtime_checkable’ to
     the ‘typing’ module.

   - bpo-36933(14): The functions ‘sys.set_coroutine_wrapper’ and
     ‘sys.get_coroutine_wrapper’ that were deprecated and marked for
     removal in 3.8 have been removed.

   - bpo-37047(15): Handle late binding and attribute access in *note
     unittest.mock.AsyncMock: c40. setup for autospeccing.  Document
     newly implemented async methods in *note unittest.mock.MagicMock:
     1091.

   - bpo-37049(16): PEP 589: Add ‘TypedDict’ to the ‘typing’ module.

   - bpo-37046(17): PEP 586: Add ‘Literal’ to the ‘typing’ module.

   - bpo-37045(18): PEP 591: Add ‘Final’ qualifier and ‘@final’
     decorator to the ‘typing’ module.

   - bpo-37035(19): Don’t log OSError based exceptions if a fatal error
     has occurred in asyncio transport.  Peer can generate almost any
     OSError, user cannot avoid these exceptions by fixing own code.
     Errors are still propagated to user code, it’s just logging them is
     pointless and pollute asyncio logs.

   - bpo-37001(20): *note symtable.symtable(): 1db9. now accepts the
     same input types for source code as the built-in *note compile():
     4b2. function.  Patch by Dino Viehland.

   - bpo-37028(21): Implement asyncio REPL

   - bpo-37027(22): Return safe to use proxy socket object from
     transport.get_extra_info(“socket”)

   - bpo-32528(23): Make asyncio.CancelledError a BaseException.

     This will address the common mistake many asyncio users make: an
     «except Exception» clause breaking Tasks cancellation.

     In addition to this change, we stop inheriting asyncio.TimeoutError
     and asyncio.InvalidStateError from their concurrent.futures.*
     counterparts.  There’s no point for these exceptions to share the
     inheritance chain.

   - bpo-1230540(24): Add a new *note threading.excepthook(): a4d.
     function which handles uncaught *note threading.Thread.run(): c33.
     exception.  It can be overridden to control how uncaught *note
     threading.Thread.run(): c33. exceptions are handled.

   - bpo-36996(25): Handle *note unittest.mock.patch(): 1094. used as a
     decorator on async functions.

   - bpo-37008(26): Add support for calling *note next(): 9da. with the
     mock resulting from *note unittest.mock.mock_open(): 11e9.

   - bpo-27737(27): Allow whitespace only header encoding in
     ‘email.header’ - by Batuhan Taskaya

   - bpo-36969(28): PDB command ‘args’ now display positional only
     arguments.  Patch contributed by Rémi Lapeyre.

   - bpo-36969(29): PDB command ‘args’ now display keyword only
     arguments.  Patch contributed by Rémi Lapeyre.

   - bpo-36983(30): Add missing names to ‘typing.__all__’: ‘ChainMap’,
     ‘ForwardRef’, ‘OrderedDict’ - by Anthony Sottile.

   - bpo-36972(31): Add SupportsIndex protocol to the typing module to
     allow type checking to detect classes that can be passed to
     ‘hex()’, ‘oct()’ and ‘bin()’.

   - bpo-32972(32): Implement ‘unittest.IsolatedAsyncioTestCase’ to help
     testing asyncio-based code.

   - bpo-36952(33): *note fileinput.input(): a02. and *note
     fileinput.FileInput: 941. 'bufsize' argument has been removed (was
     deprecated and ignored since Python 3.6), and as a result the
     'mode' and 'openhook' arguments have been made keyword-only.

   - bpo-36952(34): Starting with Python 3.3, importing ABCs from *note
     collections: 1e. is deprecated, and import should be done from
     *note collections.abc: 1f.  Still being able to import from *note
     collections: 1e. was marked for removal in 3.8, but has been
     delayed to 3.9; documentation and ‘DeprecationWarning’ clarified.

   - bpo-36949(35): Implement __repr__ for WeakSet objects.

   - bpo-36948(36): Fix *note NameError: 452. in
     ‘urllib.request.URLopener.retrieve()’.  Patch by Karthikeyan
     Singaravelan.

   - bpo-33524(37): Fix the folding of email header when the
     max_line_length is 0 or None and the header contains non-ascii
     characters.  Contributed by Licht Takeuchi (@Licht-T).

   - bpo-24564(38): *note shutil.copystat(): 1336. now ignores *note
     errno.EINVAL: 1dba. on *note os.setxattr(): 130f. which may occur
     when copying files on filesystems without extended attributes
     support.

     Original patch by Giampaolo Rodola, updated by Ying Wang.

   - bpo-36888(39): Python child processes can now access the status of
     their parent process using multiprocessing.process.parent_process

   - bpo-36921(40): Deprecate ‘@coroutine’ for sake of ‘async def’.

   - bpo-25652(41): Fix bug in ‘__rmod__’ of ‘UserString’ - by Batuhan
     Taskaya.

   - bpo-36916(42): Remove a message about an unhandled exception in a
     task when writer.write() is used without await and writer.drain()
     fails with an exception.

   - bpo-36889(43): Introduce ‘asyncio.Stream’ class that merges *note
     asyncio.StreamReader: 1c65. and *note asyncio.StreamWriter: 1a58.
     functionality.  ‘asyncio.Stream’ can work in readonly, writeonly
     and readwrite modes.  Provide ‘asyncio.connect()’,
     ‘asyncio.connect_unix()’, ‘asyncio.connect_read_pipe()’ and
     ‘asyncio.connect_write_pipe()’ factories to open ‘asyncio.Stream’
     connections.  Provide ‘asyncio.StreamServer’ and ‘UnixStreamServer’
     to serve servers with asyncio.Stream API. Modify *note
     asyncio.create_subprocess_shell(): c6e. and *note
     asyncio.create_subprocess_exec(): c6d. to use ‘asyncio.Stream’
     instead of deprecated ‘StreamReader’ and ‘StreamWriter’.  Deprecate
     *note asyncio.StreamReader: 1c65. and *note asyncio.StreamWriter:
     1a58.  Deprecate usage of private classes, e.g.
     ‘asyncio.FlowControlMixing’ and ‘asyncio.StreamReaderProtocol’
     outside of asyncio package.

   - bpo-36845(44): Added validation of integer prefixes to the
     construction of IP networks and interfaces in the ipaddress module.

   - bpo-23378(45): Add an extend action to argparser.

   - bpo-36867(46): Fix a bug making a SharedMemoryManager instance and
     its parent process use two separate resource_tracker processes.

   - bpo-23896(47): Adds a grammar to lib2to3.pygram that contains exec
     as a function not as statement.

   - bpo-36895(48): The function ‘time.clock()’ was deprecated in 3.3 in
     favor of ‘time.perf_counter()’ and marked for removal in 3.8, it
     has removed.

   - bpo-35545(49): Fix asyncio discarding IPv6 scopes when ensuring
     hostname resolutions internally

   - bpo-36887(50): Add new function *note math.isqrt(): bfa. to compute
     integer square roots.

   - bpo-34632(51): Introduce the ‘importlib.metadata’ module with
     (provisional) support for reading metadata from third-party
     packages.

   - bpo-36878(52): When using ‘type_comments=True’ in ‘ast.parse’,
     treat ‘# type: ignore’ followed by a non-alphanumeric character and
     then arbitrary text as a type ignore, instead of requiring nothing
     but whitespace or another comment.  This is to permit formations
     such as ‘# type: ignore[E1000]’.

   - bpo-36778(53): ‘cp65001’ encoding (Windows code page 65001) becomes
     an alias to ‘utf_8’ encoding.

   - bpo-36867(54): The multiprocessing.resource_tracker replaces the
     multiprocessing.semaphore_tracker module.  Other than semaphores,
     resource_tracker also tracks shared_memory segments.

   - bpo-30262(55): The ‘Cache’ and ‘Statement’ objects of the *note
     sqlite3: d4. module are not exposed to the user.  Patch by Aviv
     Palivoda.

   - bpo-24538(56): In ‘shutil.copystat()’, first copy extended file
     attributes and then file permissions, since extended attributes can
     only be set on the destination while it is still writeable.

   - bpo-36829(57): Add new *note sys.unraisablehook(): 508. function
     which can be overridden to control how «unraisable exceptions» are
     handled.  It is called when an exception has occurred but there is
     no way for Python to handle it.  For example, when a destructor
     raises an exception or during garbage collection (*note
     gc.collect(): 1b3.).

   - bpo-36832(58): Introducing ‘zipfile.Path’, a pathlib-compatible
     wrapper for traversing zip files.

   - bpo-36814(59): Fix an issue where os.posix_spawnp() would
     incorrectly raise a TypeError when file_actions is None.

   - bpo-33110(60): Handle exceptions raised by functions added by
     concurrent.futures add_done_callback correctly when the Future has
     already completed.

   - bpo-26903(61): Limit ‘max_workers’ in ‘ProcessPoolExecutor’ to 61
     to work around a WaitForMultipleObjects limitation.

   - bpo-36813(62): Fix *note QueueListener: 242. to call
     ‘queue.task_done()’ upon stopping.  Patch by Bar Harel.

   - bpo-36806(63): Forbid creation of asyncio stream objects like
     StreamReader, StreamWriter, Process, and their protocols outside of
     asyncio package.

   - bpo-36802(64): Provide both sync and async calls for
     StreamWriter.write() and StreamWriter.close()

   - bpo-36801(65): Properly handle SSL connection closing in asyncio
     StreamWriter.drain() call.

   - bpo-36785(66): Implement PEP 574 (pickle protocol 5 with
     out-of-band buffers).

   - bpo-36772(67): functools.lru_cache() can now be used as a straight
     decorator in addition to its existing usage as a function that
     returns a decorator.

   - bpo-6584(68): Add a *note BadGzipFile: bec. exception to the *note
     gzip: 6b. module.

   - bpo-36748(69): Optimized write buffering in C implementation of
     ‘TextIOWrapper’.  Writing ASCII string to ‘TextIOWrapper’ with
     ascii, latin1, or utf-8 encoding is about 20% faster.  Patch by
     Inada Naoki.

   - bpo-8138(70): Don’t mark ‘wsgiref.simple_server.SimpleServer’ as
     multi-threaded since ‘wsgiref.simple_server.WSGIServer’ is
     single-threaded.

   - bpo-22640(71): *note py_compile.compile(): c1c. now supports silent
     mode.  Patch by Joannah Nanjekye

   - bpo-29183(72): Fix double exceptions in *note
     wsgiref.handlers.BaseHandler: 1dbb. by calling its ‘close()’ method
     only when no exception is raised.

   - bpo-36548(73): Improved the repr of regular expression flags.

   - bpo-36542(74): The signature of Python functions can now be
     overridden by specifying the ‘__text_signature__’ attribute.

   - bpo-36533(75): Reinitialize logging.Handler locks in forked child
     processes instead of attempting to acquire them all in the parent
     before forking only to be released in the child process.  The
     acquire/release pattern was leading to deadlocks in code that has
     implemented any form of chained logging handlers that depend upon
     one another as the lock acquisition order cannot be guaranteed.

   - bpo-35252(76): Throw a TypeError instead of an AssertionError when
     using an invalid type annotation with singledispatch.

   - bpo-35900(77): Allow reduction methods to return a 6-item tuple
     where the 6th item specifies a custom state-setting method that’s
     called instead of the regular ‘__setstate__’ method.

   - bpo-35900(78): enable custom reduction callback registration for
     functions and classes in _pickle.c, using the new Pickler’s
     attribute ‘reducer_override’

   - bpo-36368(79): Fix a bug crashing SharedMemoryManager instances in
     interactive sessions after a ctrl-c (KeyboardInterrupt) was sent

   - bpo-31904(80): Fix mmap fail for VxWorks

   - bpo-27497(81): *note csv.DictWriter.writeheader(): 1407. now
     returns the return value of the underlying ‘csv.Writer.writerow()’
     method.  Patch contributed by Ashish Nitin Patil.

   - bpo-36239(82): Parsing .mo files now ignores comments starting and
     ending with #-#-#-#-#.

   - bpo-26707(83): Enable plistlib to read and write binary plist files
     that were created as a KeyedArchive file.  Specifically, this
     allows the plistlib to process 0x80 tokens as UID objects.

   - bpo-31904(84): Add posix module support for VxWorks.

   - bpo-35125(85): Asyncio: Remove inner callback on outer cancellation
     in shield

   - bpo-35721(86): Fix ‘asyncio.SelectorEventLoop.subprocess_exec()’
     leaks file descriptors if ‘Popen’ fails and called with
     ‘stdin=subprocess.PIPE’.  Patch by Niklas Fiekas.

   - bpo-31855(87): *note unittest.mock.mock_open(): 11e9. results now
     respects the argument of read([size]).  Patch contributed by Rémi
     Lapeyre.

   - bpo-35431(88): Implement *note math.comb(): 8e0. that returns
     binomial coefficient, that computes the number of ways to choose k
     items from n items without repetition and without order.  Patch by
     Yash Aggarwal and Keller Fuchs.

   - bpo-26660(89): Fixed permission errors in *note TemporaryDirectory:
     143c. clean up.  Previously ‘TemporaryDirectory.cleanup()’ failed
     when non-writeable or non-searchable files or directories were
     created inside a temporary directory.

   - bpo-34271(90): Add debugging helpers to ssl module.  It’s now
     possible to dump key material and to trace TLS protocol.  The
     default and stdlib contexts also support SSLKEYLOGFILE env var.

   - bpo-26467(91): Added AsyncMock to support using unittest to mock
     asyncio coroutines.  Patch by Lisa Roach.

   - bpo-33569(92): dataclasses.InitVar: Exposes the type used to create
     the init var.

   - bpo-34424(93): Fix serialization of messages containing encoded
     strings when the policy.linesep is set to a multi-character string.
     Patch by Jens Troeger.

   - bpo-34303(94): Performance of *note functools.reduce(): 21a. is
     slightly improved.  Patch by Sergey Fedoseev.

   - bpo-33361(95): Fix a bug in *note codecs.StreamRecoder: 1dbc. where
     seeking might leave old data in a buffer and break subsequent read
     calls.  Patch by Ammar Askar.

   - bpo-22454(96): The *note shlex: c9. module now exposes *note
     shlex.join(): c1e, the inverse of *note shlex.split(): 75f.  Patch
     by Bo Bayles.

   - bpo-31922(97):
     ‘asyncio.AbstractEventLoop.create_datagram_endpoint()’: Do not
     connect UDP socket when broadcast is allowed.  This allows to
     receive replies after a UDP broadcast.

   - bpo-24882(98): Change ThreadPoolExecutor to use existing idle
     threads before spinning up new ones.

   - bpo-31961(99): Added support for bytes and path-like objects in
     *note subprocess.Popen(): 4b8. on Windows.  The 'args' parameter
     now accepts a *note path-like object: 5a1. if 'shell' is ‘False’
     and a sequence containing bytes and path-like objects.  The
     'executable' parameter now accepts a bytes and *note path-like
     object: 5a1.  The 'cwd' parameter now accepts a bytes object.
     Based on patch by Anders Lorentsen.

   - bpo-33123(100): *note pathlib.Path.unlink: 1dbd. now accepts a
     'missing_ok' parameter to avoid a *note FileNotFoundError: 264.
     from being raised.  Patch by Robert Buchholz.

   - bpo-32941(101): Allow *note mmap.mmap: 51a. objects to access the
     madvise() system call (through *note mmap.mmap.madvise(): bfd.).

   - bpo-22102(102): Added support for ZIP files with disks set to 0.
     Such files are commonly created by builtin tools on Windows when
     use ZIP64 extension.  Patch by Francisco Facioni.

   - bpo-32515(103): trace.py can now run modules via python3 -m trace
     -t –module module_name

   - bpo-32299(104): Changed *note unittest.mock.patch.dict(): 194f. to
     return the patched dictionary when used as context manager.  Patch
     by Vadim Tsander.

   - bpo-27141(105): Added a ‘__copy__()’ to ‘collections.UserList’ and
     ‘collections.UserDict’ in order to correctly implement shallow
     copying of the objects.  Patch by Bar Harel.

   - bpo-31829(106): ‘\r’, ‘\0’ and ‘\x1a’ (end-of-file on Windows) are
     now escaped in protocol 0 pickles of Unicode strings.  This allows
     to load them without loss from files open in text mode in Python 2.

   - bpo-23395(107): ‘_thread.interrupt_main()’ now avoids setting the
     Python error status if the ‘SIGINT’ signal is ignored or not
     handled by Python.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37128

   (2) https://bugs.python.org/issue?@action=redirect&bpo=37120

   (3) https://bugs.python.org/issue?@action=redirect&bpo=12202

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26835

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29262

   (6) https://bugs.python.org/issue?@action=redirect&bpo=12639

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36999

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35246

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35279

   (10) https://bugs.python.org/issue?@action=redirect&bpo=37076

   (11) https://bugs.python.org/issue?@action=redirect&bpo=33725

   (12) https://bugs.python.org/issue?@action=redirect&bpo=37054

   (13) https://bugs.python.org/issue?@action=redirect&bpo=37058

   (14) https://bugs.python.org/issue?@action=redirect&bpo=36933

   (15) https://bugs.python.org/issue?@action=redirect&bpo=37047

   (16) https://bugs.python.org/issue?@action=redirect&bpo=37049

   (17) https://bugs.python.org/issue?@action=redirect&bpo=37046

   (18) https://bugs.python.org/issue?@action=redirect&bpo=37045

   (19) https://bugs.python.org/issue?@action=redirect&bpo=37035

   (20) https://bugs.python.org/issue?@action=redirect&bpo=37001

   (21) https://bugs.python.org/issue?@action=redirect&bpo=37028

   (22) https://bugs.python.org/issue?@action=redirect&bpo=37027

   (23) https://bugs.python.org/issue?@action=redirect&bpo=32528

   (24) https://bugs.python.org/issue?@action=redirect&bpo=1230540

   (25) https://bugs.python.org/issue?@action=redirect&bpo=36996

   (26) https://bugs.python.org/issue?@action=redirect&bpo=37008

   (27) https://bugs.python.org/issue?@action=redirect&bpo=27737

   (28) https://bugs.python.org/issue?@action=redirect&bpo=36969

   (29) https://bugs.python.org/issue?@action=redirect&bpo=36969

   (30) https://bugs.python.org/issue?@action=redirect&bpo=36983

   (31) https://bugs.python.org/issue?@action=redirect&bpo=36972

   (32) https://bugs.python.org/issue?@action=redirect&bpo=32972

   (33) https://bugs.python.org/issue?@action=redirect&bpo=36952

   (34) https://bugs.python.org/issue?@action=redirect&bpo=36952

   (35) https://bugs.python.org/issue?@action=redirect&bpo=36949

   (36) https://bugs.python.org/issue?@action=redirect&bpo=36948

   (37) https://bugs.python.org/issue?@action=redirect&bpo=33524

   (38) https://bugs.python.org/issue?@action=redirect&bpo=24564

   (39) https://bugs.python.org/issue?@action=redirect&bpo=36888

   (40) https://bugs.python.org/issue?@action=redirect&bpo=36921

   (41) https://bugs.python.org/issue?@action=redirect&bpo=25652

   (42) https://bugs.python.org/issue?@action=redirect&bpo=36916

   (43) https://bugs.python.org/issue?@action=redirect&bpo=36889

   (44) https://bugs.python.org/issue?@action=redirect&bpo=36845

   (45) https://bugs.python.org/issue?@action=redirect&bpo=23378

   (46) https://bugs.python.org/issue?@action=redirect&bpo=36867

   (47) https://bugs.python.org/issue?@action=redirect&bpo=23896

   (48) https://bugs.python.org/issue?@action=redirect&bpo=36895

   (49) https://bugs.python.org/issue?@action=redirect&bpo=35545

   (50) https://bugs.python.org/issue?@action=redirect&bpo=36887

   (51) https://bugs.python.org/issue?@action=redirect&bpo=34632

   (52) https://bugs.python.org/issue?@action=redirect&bpo=36878

   (53) https://bugs.python.org/issue?@action=redirect&bpo=36778

   (54) https://bugs.python.org/issue?@action=redirect&bpo=36867

   (55) https://bugs.python.org/issue?@action=redirect&bpo=30262

   (56) https://bugs.python.org/issue?@action=redirect&bpo=24538

   (57) https://bugs.python.org/issue?@action=redirect&bpo=36829

   (58) https://bugs.python.org/issue?@action=redirect&bpo=36832

   (59) https://bugs.python.org/issue?@action=redirect&bpo=36814

   (60) https://bugs.python.org/issue?@action=redirect&bpo=33110

   (61) https://bugs.python.org/issue?@action=redirect&bpo=26903

   (62) https://bugs.python.org/issue?@action=redirect&bpo=36813

   (63) https://bugs.python.org/issue?@action=redirect&bpo=36806

   (64) https://bugs.python.org/issue?@action=redirect&bpo=36802

   (65) https://bugs.python.org/issue?@action=redirect&bpo=36801

   (66) https://bugs.python.org/issue?@action=redirect&bpo=36785

   (67) https://bugs.python.org/issue?@action=redirect&bpo=36772

   (68) https://bugs.python.org/issue?@action=redirect&bpo=6584

   (69) https://bugs.python.org/issue?@action=redirect&bpo=36748

   (70) https://bugs.python.org/issue?@action=redirect&bpo=8138

   (71) https://bugs.python.org/issue?@action=redirect&bpo=22640

   (72) https://bugs.python.org/issue?@action=redirect&bpo=29183

   (73) https://bugs.python.org/issue?@action=redirect&bpo=36548

   (74) https://bugs.python.org/issue?@action=redirect&bpo=36542

   (75) https://bugs.python.org/issue?@action=redirect&bpo=36533

   (76) https://bugs.python.org/issue?@action=redirect&bpo=35252

   (77) https://bugs.python.org/issue?@action=redirect&bpo=35900

   (78) https://bugs.python.org/issue?@action=redirect&bpo=35900

   (79) https://bugs.python.org/issue?@action=redirect&bpo=36368

   (80) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (81) https://bugs.python.org/issue?@action=redirect&bpo=27497

   (82) https://bugs.python.org/issue?@action=redirect&bpo=36239

   (83) https://bugs.python.org/issue?@action=redirect&bpo=26707

   (84) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (85) https://bugs.python.org/issue?@action=redirect&bpo=35125

   (86) https://bugs.python.org/issue?@action=redirect&bpo=35721

   (87) https://bugs.python.org/issue?@action=redirect&bpo=31855

   (88) https://bugs.python.org/issue?@action=redirect&bpo=35431

   (89) https://bugs.python.org/issue?@action=redirect&bpo=26660

   (90) https://bugs.python.org/issue?@action=redirect&bpo=34271

   (91) https://bugs.python.org/issue?@action=redirect&bpo=26467

   (92) https://bugs.python.org/issue?@action=redirect&bpo=33569

   (93) https://bugs.python.org/issue?@action=redirect&bpo=34424

   (94) https://bugs.python.org/issue?@action=redirect&bpo=34303

   (95) https://bugs.python.org/issue?@action=redirect&bpo=33361

   (96) https://bugs.python.org/issue?@action=redirect&bpo=22454

   (97) https://bugs.python.org/issue?@action=redirect&bpo=31922

   (98) https://bugs.python.org/issue?@action=redirect&bpo=24882

   (99) https://bugs.python.org/issue?@action=redirect&bpo=31961

   (100) https://bugs.python.org/issue?@action=redirect&bpo=33123

   (101) https://bugs.python.org/issue?@action=redirect&bpo=32941

   (102) https://bugs.python.org/issue?@action=redirect&bpo=22102

   (103) https://bugs.python.org/issue?@action=redirect&bpo=32515

   (104) https://bugs.python.org/issue?@action=redirect&bpo=32299

   (105) https://bugs.python.org/issue?@action=redirect&bpo=27141

   (106) https://bugs.python.org/issue?@action=redirect&bpo=31829

   (107) https://bugs.python.org/issue?@action=redirect&bpo=23395


File: python.info,  Node: Documentation<51>,  Next: Tests<50>,  Prev: Library<157>,  Up: Python 3 8 0 beta 1

1.24.57.4 Documentation
.......................

   - bpo-36896(1): Clarify that some types have unstable constructor
     signature between Python versions.

   - bpo-36686(2): Improve documentation of the stdin, stdout, and
     stderr arguments of the ‘asyncio.subprocess_exec’ function to
     specify which values are supported.  Also mention that decoding as
     text is not supported.

     Add a few tests to verify that the various values passed to the
     std* arguments actually work.

   - bpo-36984(3): Improve version added references in ‘typing’ module -
     by Anthony Sottile.

   - bpo-36868(4): What’s new now mentions
     SSLContext.hostname_checks_common_name instead of
     SSLContext.host_flags.

   - bpo-35924(5): Add a note to the ‘curses.addstr()’ documentation to
     warn that multiline strings can cause segfaults because of an
     ncurses bug.

   - bpo-36783(6): Added C API Documentation for Time_FromTimeAndFold
     and PyDateTime_FromDateAndTimeAndFold as per PEP 495.  Patch by
     Edison Abahurire.

   - bpo-36797(7): More of the legacy distutils documentation has been
     either pruned, or else more clearly marked as being retained solely
     until the setuptools documentation covers it independently.

   - bpo-22865(8): Add detail to the documentation on the ‘pty.spawn’
     function.

   - bpo-35397(9): Remove deprecation and document
     urllib.parse.unwrap().  Patch contributed by Rémi Lapeyre.

   - bpo-32995(10): Added the context variable in glossary.

   - bpo-33519(11): Clarify that ‘copy()’ is not part of the
     ‘MutableSequence’ ABC.

   - bpo-33482(12): Make ‘codecs.StreamRecoder.writelines’ take a list
     of bytes.

   - bpo-25735(13): Added documentation for func factorial to indicate
     that returns integer values

   - bpo-20285(14): Expand object.__doc__ (docstring) to make it
     clearer.  Modify pydoc.py so that help(object) lists object methods
     (for other classes, help omits methods of the object base class.)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36896

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36686

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36984

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36868

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35924

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36783

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36797

   (8) https://bugs.python.org/issue?@action=redirect&bpo=22865

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35397

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32995

   (11) https://bugs.python.org/issue?@action=redirect&bpo=33519

   (12) https://bugs.python.org/issue?@action=redirect&bpo=33482

   (13) https://bugs.python.org/issue?@action=redirect&bpo=25735

   (14) https://bugs.python.org/issue?@action=redirect&bpo=20285


File: python.info,  Node: Tests<50>,  Next: Build<58>,  Prev: Documentation<51>,  Up: Python 3 8 0 beta 1

1.24.57.5 Tests
...............

   - bpo-37069(1): Modify test_coroutines, test_cprofile,
     test_generators, test_raise, test_ssl and test_yield_from to use
     *note test.support.catch_unraisable_exception(): 1da5. rather than
     *note test.support.captured_stderr(): 1dc0.

   - bpo-37098(2): Fix test_memfd_create on older Linux Kernels.

   - bpo-37081(3): Test with OpenSSL 1.1.1c

   - bpo-36829(4): Add *note test.support.catch_unraisable_exception():
     1da5.: context manager catching unraisable exception using *note
     sys.unraisablehook(): 508.

   - bpo-36915(5): The main regrtest process now always removes all
     temporary directories of worker processes even if they crash or if
     they are killed on KeyboardInterrupt (CTRL+c).

   - bpo-36719(6): «python3 -m test -jN …» now continues the execution
     of next tests when a worker process crash (CHILD_ERROR state).
     Previously, the test suite stopped immediately.  Use –failfast to
     stop at the first error.

   - bpo-36816(7): Update Lib/test/selfsigned_pythontestdotnet.pem to
     match self-signed.pythontest.net’s new TLS certificate.

   - bpo-35925(8): Skip httplib and nntplib networking tests when they
     would otherwise fail due to a modern OS or distro with a default
     OpenSSL policy of rejecting connections to servers with weak
     certificates.

   - bpo-36782(9): Add tests for several C API functions in the *note
     datetime: 34. module.  Patch by Edison Abahurire.

   - bpo-36342(10): Fix test_multiprocessing in test_venv if platform
     lacks functioning sem_open.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37069

   (2) https://bugs.python.org/issue?@action=redirect&bpo=37098

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37081

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36829

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36915

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36719

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36816

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35925

   (9) https://bugs.python.org/issue?@action=redirect&bpo=36782

   (10) https://bugs.python.org/issue?@action=redirect&bpo=36342


File: python.info,  Node: Build<58>,  Next: Windows<50>,  Prev: Tests<50>,  Up: Python 3 8 0 beta 1

1.24.57.6 Build
...............

   - bpo-36721(1): To embed Python into an application, a new ‘--embed’
     option must be passed to ‘python3-config --libs --embed’ to get
     ‘-lpython3.8’ (link the application to libpython).  To support both
     3.8 and older, try ‘python3-config --libs --embed’ first and
     fallback to ‘python3-config --libs’ (without ‘--embed’) if the
     previous command fails.

     Add a pkg-config ‘python-3.8-embed’ module to embed Python into an
     application: ‘pkg-config python-3.8-embed --libs’ includes
     ‘-lpython3.8’.  To support both 3.8 and older, try ‘pkg-config
     python-X.Y-embed --libs’ first and fallback to ‘pkg-config
     python-X.Y --libs’ (without ‘--embed’) if the previous command
     fails (replace ‘X.Y’ with the Python version).

     On the other hand, ‘pkg-config python3.8 --libs’ no longer contains
     ‘-lpython3.8’.  C extensions must not be linked to libpython
     (except on Android, case handled by the script); this change is
     backward incompatible on purpose.

   - bpo-36786(2): «make install» now runs compileall in parallel.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36721

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36786


File: python.info,  Node: Windows<50>,  Next: macOS<39>,  Prev: Build<58>,  Up: Python 3 8 0 beta 1

1.24.57.7 Windows
.................

   - bpo-36965(1): include of STATUS_CONTROL_C_EXIT without depending on
     MSC compiler

   - bpo-35926(2): Update to OpenSSL 1.1.1b for Windows.

   - bpo-29883(3): Add Windows support for UDP transports for the
     Proactor Event Loop.  Patch by Adam Meily.

   - bpo-33407(4): The *note Py_DEPRECATED(): c9d. macro has been
     implemented for MSVC.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36965

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35926

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29883

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33407


File: python.info,  Node: macOS<39>,  Next: IDLE<33>,  Prev: Windows<50>,  Up: Python 3 8 0 beta 1

1.24.57.8 macOS
...............

   - bpo-36231(1): Support building Python on macOS without /usr/include
     installed.  As of macOS 10.14, system header files are only
     available within an SDK provided by either the Command Line Tools
     or the Xcode app.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36231


File: python.info,  Node: IDLE<33>,  Next: Tools/Demos<34>,  Prev: macOS<39>,  Up: Python 3 8 0 beta 1

1.24.57.9 IDLE
..............

   - bpo-35610(1): Replace now redundant .context_use_ps1 with
     .prompt_last_line.  This finishes change started in bpo-31858(2).

   - bpo-37038(3): Make idlelib.run runnable; add test clause.

   - bpo-36958(4): Print any argument other than None or int passed to
     SystemExit or sys.exit().

   - bpo-36807(5): When saving a file, call os.fsync() so bits are
     flushed to e.g.  USB drive.

   - bpo-32411(6): In browser.py, remove extraneous sorting by line
     number since dictionary was created in line number order.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35610

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31858

   (3) https://bugs.python.org/issue?@action=redirect&bpo=37038

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36958

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36807

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32411


File: python.info,  Node: Tools/Demos<34>,  Next: C API<53>,  Prev: IDLE<33>,  Up: Python 3 8 0 beta 1

1.24.57.10 Tools/Demos
......................

   - bpo-37053(1): Handle strings like u»bar» correctly in
     Tools/parser/unparse.py.  Patch by Chih-Hsuan Yen.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=37053


File: python.info,  Node: C API<53>,  Prev: Tools/Demos<34>,  Up: Python 3 8 0 beta 1

1.24.57.11 C API
................

   - bpo-36763(1): Implement the PEP 587(2) «Python Initialization
     Configuration».

   - bpo-36379(3): Fix crashes when attempting to use the 'modulo'
     parameter when ‘__ipow__’ is implemented in C.

   - bpo-37107(4): Update *note PyObject_CallMethodObjArgs(): 1dc7. and
     ‘_PyObject_CallMethodIdObjArgs’ to use ‘_PyObject_GetMethod’ to
     avoid creating a bound method object in many cases.  Patch by
     Michael J. Sullivan.

   - bpo-36974(5): Implement PEP 590(6): Vectorcall: a fast calling
     protocol for CPython.  This is a new protocol to optimize calls of
     custom callable objects.

   - bpo-36763(7): ‘Py_Main()’ now returns the exitcode rather than
     calling ‘Py_Exit(exitcode)’ when calling ‘PyErr_Print()’ if the
     current exception type is ‘SystemExit’.

   - bpo-36922(8): Add new type flag ‘Py_TPFLAGS_METHOD_DESCRIPTOR’ for
     objects behaving like unbound methods.  These are objects
     supporting the optimization given by the
     ‘LOAD_METHOD’/‘CALL_METHOD’ opcodes.  See PEP 590.

   - bpo-36728(9): The ‘PyEval_ReInitThreads()’ function has been
     removed from the C API. It should not be called explicitly: use
     *note PyOS_AfterFork_Child(): 430. instead.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36763

   (2) https://peps.python.org/pep-0587/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36379

   (4) https://bugs.python.org/issue?@action=redirect&bpo=37107

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36974

   (6) https://peps.python.org/pep-0590/

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36763

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36922

   (9) https://bugs.python.org/issue?@action=redirect&bpo=36728


File: python.info,  Node: Python 3 8 0 alpha 4,  Next: Python 3 8 0 alpha 3,  Prev: Python 3 8 0 beta 1,  Up: Changelog

1.24.58 Python 3.8.0 alpha 4
----------------------------

'Release date: 2019-05-06'

* Menu:

* Security: Security<44>.
* Core and Builtins: Core and Builtins<155>.
* Library: Library<158>.
* Documentation: Documentation<52>.
* Tests: Tests<51>.
* Build: Build<59>.
* Windows: Windows<51>.
* macOS: macOS<40>.
* IDLE: IDLE<34>.
* Tools/Demos: Tools/Demos<35>.
* C API: C API<54>.


File: python.info,  Node: Security<44>,  Next: Core and Builtins<155>,  Up: Python 3 8 0 alpha 4

1.24.58.1 Security
..................

   - bpo-36742(1): Fixes mishandling of pre-normalization characters in
     urlsplit().

   - bpo-30458(2): Address CVE 2019-9740(3) by disallowing URL paths
     with embedded whitespace or control characters through into the
     underlying http client request.  Such potentially malicious header
     injection URLs now cause an http.client.InvalidURL exception to be
     raised.

   - bpo-35755(4): *note shutil.which(): 6dc. now uses
     ‘os.confstr("CS_PATH")’ if available and if the ‘PATH’ environment
     variable is not set.  Remove also the current directory from
     ‘posixpath.defpath’.  On Unix, *note shutil.which(): 6dc. and the
     *note subprocess: dc. module no longer search the executable in the
     current directory if the ‘PATH’ environment variable is not set.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36742

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30458

   (3) https://www.cve.org/CVERecord?id=CVE-2019-9740

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35755


File: python.info,  Node: Core and Builtins<155>,  Next: Library<158>,  Prev: Security<44>,  Up: Python 3 8 0 alpha 4

1.24.58.2 Core and Builtins
...........................

   - bpo-36722(1): In debug build, import now also looks for C
     extensions compiled in release mode and for C extensions compiled
     in the stable ABI.

   - bpo-32849(2): Fix Python Initialization code on FreeBSD to detect
     properly when stdin file descriptor (fd 0) is invalid.

   - bpo-36623(3): Remove parser headers and related function
     declarations that lack implementations after the removal of pgen.

   - bpo-20180(4): ‘dict.pop()’ is now up to 33% faster thanks to
     Argument Clinic.  Patch by Inada Naoki.

   - bpo-36611(5): Debug memory allocators: disable serialno field by
     default from debug hooks on Python memory allocators to reduce the
     memory footprint by 5%.  Enable *note tracemalloc: 105. to get the
     traceback where a memory block has been allocated when a fatal
     memory error is logged to decide where to put a breakpoint.
     Compile Python with ‘PYMEM_DEBUG_SERIALNO’ defined to get back the
     field.

   - bpo-36588(6): On AIX, *note sys.platform: 291. doesn’t contain the
     major version anymore.  Always return ‘'aix'’, instead of ‘'aix3'’
     ..  ‘'aix7'’.  Since older Python versions include the version
     number, it is recommended to always use
     ‘sys.platform.startswith('aix')’.  Contributed by M. Felt.

   - bpo-36549(7): Change str.capitalize to use titlecase for the first
     character instead of uppercase.

   - bpo-36540(8): Implement PEP 570(9) (Python positional-only
     parameters).  Patch by Pablo Galindo.

   - bpo-36475(10): ‘PyEval_AcquireLock()’ and ‘PyEval_AcquireThread()’
     now terminate the current thread if called while the interpreter is
     finalizing, making them consistent with *note
     PyEval_RestoreThread(): 648, *note Py_END_ALLOW_THREADS(): c81, and
     *note PyGILState_Ensure(): 64a.

   - bpo-36504(11): Fix signed integer overflow in _ctypes.c’s
     ‘PyCArrayType_new()’.

   - bpo-20844(12): Fix running script with encoding cookie and LF line
     ending may fail on Windows.

   - bpo-24214(13): Fixed support of the surrogatepass error handler in
     the UTF-8 incremental decoder.

   - bpo-36452(14): Changing ‘dict’ keys during iteration of the dict
     itself, ‘keys()’, ‘values()’, or ‘items()’ will now be detected in
     certain corner cases where keys are deleted/added so that the
     number of keys isn’t changed.  A ‘RuntimeError’ will be raised
     after ‘len(dict)’ iterations.  Contributed by Thomas Perl.

   - bpo-36459(15): Fix a possible double ‘PyMem_FREE()’ due to
     tokenizer.c’s ‘tok_nextc()’.

   - bpo-36433(16): Fixed TypeError message in classmethoddescr_call.

   - bpo-36430(17): Fix a possible reference leak in *note
     itertools.count(): 148b.

   - bpo-36440(18): Include node names in ‘ParserError’ messages,
     instead of numeric IDs.  Patch by A. Skrobov.

   - bpo-36143(19): Regenerate *note keyword: 88. from the Grammar and
     Tokens file using pgen.  Patch by Pablo Galindo.

   - bpo-18372(20): Add missing *note PyObject_GC_Track(): 170b. calls
     in the *note pickle: ab. module.  Patch by Zackery Spytz.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36722

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32849

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36623

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20180

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36611

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36588

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36549

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36540

   (9) https://peps.python.org/pep-0570/

   (10) https://bugs.python.org/issue?@action=redirect&bpo=36475

   (11) https://bugs.python.org/issue?@action=redirect&bpo=36504

   (12) https://bugs.python.org/issue?@action=redirect&bpo=20844

   (13) https://bugs.python.org/issue?@action=redirect&bpo=24214

   (14) https://bugs.python.org/issue?@action=redirect&bpo=36452

   (15) https://bugs.python.org/issue?@action=redirect&bpo=36459

   (16) https://bugs.python.org/issue?@action=redirect&bpo=36433

   (17) https://bugs.python.org/issue?@action=redirect&bpo=36430

   (18) https://bugs.python.org/issue?@action=redirect&bpo=36440

   (19) https://bugs.python.org/issue?@action=redirect&bpo=36143

   (20) https://bugs.python.org/issue?@action=redirect&bpo=18372


File: python.info,  Node: Library<158>,  Next: Documentation<52>,  Prev: Core and Builtins<155>,  Up: Python 3 8 0 alpha 4

1.24.58.3 Library
.................

   - bpo-35952(1): Fix pythoninfo when the compiler is missing.

   - bpo-28238(2): The ‘.find*()’ methods of xml.etree.ElementTree can
     now search for wildcards like ‘{*}tag’ and ‘{ns}*’ that match a tag
     in any namespace or all tags in a namespace.  Patch by Stefan
     Behnel.

   - bpo-26978(3): ‘pathlib.path.link_to()’ is now implemented.  It
     creates a hard link pointing to a path.

   - bpo-1613500(4): *note fileinput.FileInput: 941. now uses the input
     file mode to correctly set the output file mode (previously it was
     hardcoded to ‘'w'’) when ‘inplace=True’ is passed to its
     constructor.

   - bpo-36734(5): Fix compilation of ‘faulthandler.c’ on HP-UX.
     Initialize ‘stack_t current_stack’ to zero using ‘memset()’.

   - bpo-13611(6): The xml.etree.ElementTree packages gained support for
     C14N 2.0 serialisation.  Patch by Stefan Behnel.

   - bpo-36669(7): Add missing matrix multiplication operator support to
     weakref.proxy.

   - bpo-36676(8): The XMLParser() in xml.etree.ElementTree provides
     namespace prefix context to the parser target if it defines the
     callback methods «start_ns()» and/or «end_ns()».  Patch by Stefan
     Behnel.

   - bpo-36673(9): The TreeBuilder and XMLPullParser in
     xml.etree.ElementTree gained support for parsing comments and
     processing instructions.  Patch by Stefan Behnel.

   - bpo-36650(10): The C version of functools.lru_cache() was treating
     calls with an empty ‘**kwargs’ dictionary as being distinct from
     calls with no keywords at all.  This did not result in an incorrect
     answer, but it did trigger an unexpected cache miss.

   - bpo-28552(11): Fix ‘distutils.sysconfig’ if *note sys.executable:
     3ed. is ‘None’ or an empty string: use *note os.getcwd(): 18f1. to
     initialize ‘project_base’.  Fix also the distutils build command:
     don’t use *note sys.executable: 3ed. if it is ‘None’ or an empty
     string.

   - bpo-35755(12): *note shutil.which(): 6dc. and
     ‘distutils.spawn.find_executable’ now use ‘os.confstr("CS_PATH")’
     if available instead of *note os.defpath: 1dcc, if the ‘PATH’
     environment variable is not set.  Moreover, don’t use
     ‘os.confstr("CS_PATH")’ nor *note os.defpath: 1dcc. if the ‘PATH’
     environment variable is set to an empty string.

   - bpo-25430(13): improve performance of ‘IPNetwork.__contains__()’

   - bpo-30485(14): Path expressions in xml.etree.ElementTree can now
     avoid explicit namespace prefixes for tags (or the «{namespace}tag»
     notation) by passing a default namespace with an empty string
     prefix.

   - bpo-36613(15): Fix *note asyncio: b. wait() not removing callback
     if exception

   - bpo-36598(16): Fix ‘isinstance’ check for Mock objects with spec
     when the code is executed under tracing.  Patch by Karthikeyan
     Singaravelan.

   - bpo-18748(17): In development mode (*note -X: 16f. ‘dev’) and in
     debug build, the *note io.IOBase: 506. destructor now logs
     ‘close()’ exceptions.  These exceptions are silent by default in
     release mode.

   - bpo-36575(18): The ‘_lsprof’ module now uses internal timer same to
     ‘time.perf_counter()’ by default.  ‘gettimeofday(2)’ was used on
     Unix.  New timer has better resolution on most Unix platforms and
     timings are no longer impacted by system clock updates since
     ‘perf_counter()’ is monotonic.  Patch by Inada Naoki.

   - bpo-33461(19): ‘json.loads’ now emits ‘DeprecationWarning’ when
     ‘encoding’ option is specified.  Patch by Matthias Bussonnier.

   - bpo-36559(20): The random module now prefers the lean internal
     _sha512 module over hashlib for seed(version=2) to optimize import
     time.

   - bpo-17561(21): Set backlog=None as the default for
     socket.create_server.

   - bpo-34373(22): Fix *note time.mktime(): 13f0. error handling on AIX
     for year before 1970.

   - bpo-36232(23): Improve error message when trying to open existing
     DBM database that actually doesn’t exist.  Patch by Marco Rougeth.

   - bpo-36546(24): Add statistics.quantiles()

   - bpo-36050(25): Optimized ‘http.client.HTTPResponse.read()’ for
     large response.  Patch by Inada Naoki.

   - bpo-36522(26): If 'debuglevel' is set to >0 in *note http.client:
     73, print all values for headers with multiple values for the same
     header name.  Patch by Matt Houglum.

   - bpo-36492(27): Deprecated passing required arguments like 'func' as
     keyword arguments in functions which should accept arbitrary
     keyword arguments and pass them to other function.  Arbitrary
     keyword arguments (even with names «self» and «func») can now be
     passed to these functions if the required arguments are passed as
     positional arguments.

   - bpo-27181(28): Add statistics.geometric_mean().

   - bpo-30427(29): ‘os.path.normcase()’ relies on ‘os.fspath()’ to
     check the type of its argument.  Redundant checks have been removed
     from its ‘posixpath.normcase()’ and ‘ntpath.normcase()’
     implementations.  Patch by Wolfgang Maier.

   - bpo-36385(30): Stop rejecting IPv4 octets for being ambiguously
     octal.  Leading zeros are ignored, and no longer are assumed to
     specify octal octets.  Octets are always decimal numbers.  Octets
     must still be no more than three digits, including leading zeroes.

   - bpo-36434(31): Errors during writing to a ZIP file no longer
     prevent to properly close it.

   - bpo-36407(32): Fixed wrong indentation writing for CDATA section in
     xml.dom.minidom.  Patch by Vladimir Surjaninov.

   - bpo-36326(33): inspect.getdoc() can now find docstrings for member
     objects when __slots__ is a dictionary.

   - bpo-36366(34): Calling ‘stop()’ on an unstarted or stopped *note
     unittest.mock.patch(): 1094. object will now return ‘None’ instead
     of raising *note RuntimeError: 244, making the method idempotent.
     Patch by Karthikeyan Singaravelan.

   - bpo-36348(35): The ‘imap.IMAP4.logout()’ method no longer ignores
     silently arbitrary exceptions.

   - bpo-31904(36): Add time module support and fix test_time failures
     for VxWorks.

   - bpo-36227(37): Added support for keyword arguments
     ‘default_namespace’ and ‘xml_declaration’ in functions
     ‘ElementTree.tostring()’ and ‘ElementTree.tostringlist()’.

   - bpo-36004(38): Added new alternate constructors *note
     datetime.date.fromisocalendar(): be1. and *note
     datetime.datetime.fromisocalendar(): be2, which construct date
     objects from ISO year, week number and weekday; these are the
     inverse of each class’s ‘isocalendar’ method.  Patch by Paul
     Ganssle.

   - bpo-35936(39): *note modulefinder: 95. no longer depends on the
     deprecated *note imp: 7a. module, and the initializer for *note
     modulefinder.ModuleFinder: 1dcd. now has immutable default
     arguments.  Patch by Brandt Bucher.

   - bpo-35376(40): *note modulefinder: 95. correctly handles modules
     that have the same name as a bad package.  Patch by Brandt Bucher.

   - bpo-17396(41): *note modulefinder: 95. no longer crashes when
     encountering syntax errors in followed imports.  Patch by Brandt
     Bucher.

   - bpo-35934(42): Added *note create_server(): c22. and *note
     has_dualstack_ipv6(): c23. convenience functions to automate the
     necessary tasks usually involved when creating a server socket,
     including accepting both IPv4 and IPv6 connections on the same
     socket.  (Contributed by Giampaolo Rodola in bpo-17561(43).)

   - bpo-23078(44): Add support for *note classmethod(): 48f. and *note
     staticmethod(): 453. to *note unittest.mock.create_autospec():
     191c.  Initial patch by Felipe Ochoa.

   - bpo-35416(45): Fix potential resource warnings in distutils.  Patch
     by Mickaël Schoentgen.

   - bpo-25451(46): Add transparency methods to ‘tkinter.PhotoImage’.
     Patch by Zackery Spytz.

   - bpo-35082(47): Don’t return deleted attributes when calling dir on
     a *note unittest.mock.Mock: c41.

   - bpo-34547(48): *note wsgiref.handlers.BaseHandler: 1dbb. now
     handles abrupt client connection terminations gracefully.  Patch by
     Petter Strandmark.

   - bpo-31658(49): *note xml.sax.parse(): 1dce. now supports *note
     path-like: 5a1.  Patch by Mickaël Schoentgen.

   - bpo-34139(50): Remove stale unix datagram socket before binding

   - bpo-33530(51): Implemented Happy Eyeballs in
     ‘asyncio.create_connection()’.  Added two new arguments,
     'happy_eyeballs_delay' and 'interleave', to specify Happy Eyeballs
     behavior.

   - bpo-33291(52): Do not raise AttributeError when calling the inspect
     functions isgeneratorfunction, iscoroutinefunction,
     isasyncgenfunction on a method created from an arbitrary callable.
     Instead, return False.

   - bpo-31310(53): Fix the multiprocessing.semaphore_tracker so it is
     reused by child processes

   - bpo-31292(54): Fix ‘setup.py check --restructuredtext’ for files
     containing ‘include’ directives.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35952

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28238

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26978

   (4) https://bugs.python.org/issue?@action=redirect&bpo=1613500

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36734

   (6) https://bugs.python.org/issue?@action=redirect&bpo=13611

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36669

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36676

   (9) https://bugs.python.org/issue?@action=redirect&bpo=36673

   (10) https://bugs.python.org/issue?@action=redirect&bpo=36650

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28552

   (12) https://bugs.python.org/issue?@action=redirect&bpo=35755

   (13) https://bugs.python.org/issue?@action=redirect&bpo=25430

   (14) https://bugs.python.org/issue?@action=redirect&bpo=30485

   (15) https://bugs.python.org/issue?@action=redirect&bpo=36613

   (16) https://bugs.python.org/issue?@action=redirect&bpo=36598

   (17) https://bugs.python.org/issue?@action=redirect&bpo=18748

   (18) https://bugs.python.org/issue?@action=redirect&bpo=36575

   (19) https://bugs.python.org/issue?@action=redirect&bpo=33461

   (20) https://bugs.python.org/issue?@action=redirect&bpo=36559

   (21) https://bugs.python.org/issue?@action=redirect&bpo=17561

   (22) https://bugs.python.org/issue?@action=redirect&bpo=34373

   (23) https://bugs.python.org/issue?@action=redirect&bpo=36232

   (24) https://bugs.python.org/issue?@action=redirect&bpo=36546

   (25) https://bugs.python.org/issue?@action=redirect&bpo=36050

   (26) https://bugs.python.org/issue?@action=redirect&bpo=36522

   (27) https://bugs.python.org/issue?@action=redirect&bpo=36492

   (28) https://bugs.python.org/issue?@action=redirect&bpo=27181

   (29) https://bugs.python.org/issue?@action=redirect&bpo=30427

   (30) https://bugs.python.org/issue?@action=redirect&bpo=36385

   (31) https://bugs.python.org/issue?@action=redirect&bpo=36434

   (32) https://bugs.python.org/issue?@action=redirect&bpo=36407

   (33) https://bugs.python.org/issue?@action=redirect&bpo=36326

   (34) https://bugs.python.org/issue?@action=redirect&bpo=36366

   (35) https://bugs.python.org/issue?@action=redirect&bpo=36348

   (36) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (37) https://bugs.python.org/issue?@action=redirect&bpo=36227

   (38) https://bugs.python.org/issue?@action=redirect&bpo=36004

   (39) https://bugs.python.org/issue?@action=redirect&bpo=35936

   (40) https://bugs.python.org/issue?@action=redirect&bpo=35376

   (41) https://bugs.python.org/issue?@action=redirect&bpo=17396

   (42) https://bugs.python.org/issue?@action=redirect&bpo=35934

   (43) https://bugs.python.org/issue?@action=redirect&bpo=17561

   (44) https://bugs.python.org/issue?@action=redirect&bpo=23078

   (45) https://bugs.python.org/issue?@action=redirect&bpo=35416

   (46) https://bugs.python.org/issue?@action=redirect&bpo=25451

   (47) https://bugs.python.org/issue?@action=redirect&bpo=35082

   (48) https://bugs.python.org/issue?@action=redirect&bpo=34547

   (49) https://bugs.python.org/issue?@action=redirect&bpo=31658

   (50) https://bugs.python.org/issue?@action=redirect&bpo=34139

   (51) https://bugs.python.org/issue?@action=redirect&bpo=33530

   (52) https://bugs.python.org/issue?@action=redirect&bpo=33291

   (53) https://bugs.python.org/issue?@action=redirect&bpo=31310

   (54) https://bugs.python.org/issue?@action=redirect&bpo=31292


File: python.info,  Node: Documentation<52>,  Next: Tests<51>,  Prev: Library<158>,  Up: Python 3 8 0 alpha 4

1.24.58.4 Documentation
.......................

   - bpo-36625(1): Remove obsolete comments from docstrings in
     fractions.Fraction

   - bpo-30840(2): Document relative imports

   - bpo-36523(3): Add docstring for io.IOBase.writelines().

   - bpo-36425(4): New documentation translation: Simplified Chinese(5).

   - bpo-36345(6): Avoid the duplication of code from
     ‘Tools/scripts/serve.py’ in using the ‘literalinclude’ directive
     for the basic wsgiref-based web server in the documentation of
     *note wsgiref: 11e.  Contributed by Stéphane Wirtel.

   - bpo-36345(7): Using the code of the ‘Tools/scripts/serve.py’ script
     as an example in the *note wsgiref: 11e. documentation.
     Contributed by Stéphane Wirtel.

   - bpo-36157(8): Added documentation for PyInterpreterState_Main().

   - bpo-33043(9): Updates the docs.python.org page with the addition of
     a “Contributing to Docs” link at the end of the page (between
     “Reporting Bugs” and “About Documentation”).  Updates the “Found a
     Bug” page with additional links and information in the
     Documentation Bugs section.

   - bpo-35581(10): @typing.type_check_only now allows type stubs to
     mark functions and classes not available during runtime.

   - bpo-33832(11): Add glossary entry for “magic method”.

   - bpo-32913(12): Added re.Match.groupdict example to regex HOWTO.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36625

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30840

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36523

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36425

   (5) https://docs.python.org/zh-cn/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36345

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36345

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36157

   (9) https://bugs.python.org/issue?@action=redirect&bpo=33043

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35581

   (11) https://bugs.python.org/issue?@action=redirect&bpo=33832

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32913


File: python.info,  Node: Tests<51>,  Next: Build<59>,  Prev: Documentation<52>,  Up: Python 3 8 0 alpha 4

1.24.58.5 Tests
...............

   - bpo-36719(1): regrtest now always detects uncollectable objects.
     Previously, the check was only enabled by ‘--findleaks’.  The check
     now also works with ‘-jN/--multiprocess N’.  ‘--findleaks’ becomes
     a deprecated alias to ‘--fail-env-changed’.

   - bpo-36725(2): When using multiprocessing mode (-jN), regrtest now
     better reports errors if a worker process fails, and it exits
     immediately on a worker thread failure or when interrupted.

   - bpo-36454(3): Change test_time.test_monotonic() to test only the
     lower bound of elapsed time after a sleep command rather than the
     upper bound.  This prevents unnecessary test failures on slow
     buildbots.  Patch by Victor Stinner.

   - bpo-32424(4): Improve test coverage for xml.etree.ElementTree.
     Patch by Gordon P. Hemsley.

   - bpo-32424(5): Fix typo in test_cyclic_gc() test for
     xml.etree.ElementTree.  Patch by Gordon P. Hemsley.

   - bpo-36635(6): Add a new ‘_testinternalcapi’ module to test the
     internal C API.

   - bpo-36629(7): Fix ‘test_imap4_host_default_value()’ of
     ‘test_imaplib’: catch also *note errno.ENETUNREACH: 1dd1. error.

   - bpo-36611(8): Fix ‘test_sys.test_getallocatedblocks()’ when *note
     tracemalloc: 105. is enabled.

   - bpo-36560(9): Fix reference leak hunting in regrtest: compute also
     deltas (of reference count, allocated memory blocks, file
     descriptor count) during warmup, to ensure that everything is
     initialized before starting to hunt reference leaks.

   - bpo-36565(10): Fix reference hunting (‘python3 -m test -R 3:3’)
     when Python has no built-in abc module.

   - bpo-31904(11): Port test_resource to VxWorks: skip tests cases
     setting RLIMIT_FSIZE and RLIMIT_CPU.

   - bpo-31904(12): Fix test_tabnanny on VxWorks: adjust ENOENT error
     message.

   - bpo-36436(13): Fix ‘_testcapi.pymem_buffer_overflow()’: handle
     memory allocation failure.

   - bpo-31904(14): Fix test_utf8_mode on VxWorks: Python always use
     UTF-8 on VxWorks.

   - bpo-36341(15): Fix tests that may fail with PermissionError upon
     calling bind() on AF_UNIX sockets.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36719

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36725

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36454

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32424

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32424

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36635

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36629

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36611

   (9) https://bugs.python.org/issue?@action=redirect&bpo=36560

   (10) https://bugs.python.org/issue?@action=redirect&bpo=36565

   (11) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (13) https://bugs.python.org/issue?@action=redirect&bpo=36436

   (14) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (15) https://bugs.python.org/issue?@action=redirect&bpo=36341


File: python.info,  Node: Build<59>,  Next: Windows<51>,  Prev: Tests<51>,  Up: Python 3 8 0 alpha 4

1.24.58.6 Build
...............

   - bpo-36747(1): Remove the stale scriptsinstall Makefile target.

   - bpo-21536(2): On Unix, C extensions are no longer linked to
     libpython except on Android and Cygwin.

     It is now possible for a statically linked Python to load a C
     extension built using a shared library Python.

     When Python is embedded, ‘libpython’ must not be loaded with
     ‘RTLD_LOCAL’, but ‘RTLD_GLOBAL’ instead.  Previously, using
     ‘RTLD_LOCAL’, it was already not possible to load C extensions
     which were not linked to ‘libpython’, such as C extensions of the
     standard library built by the ‘*shared*’ section of
     ‘Modules/Setup’.

     distutils, python-config and python-config.py have been modified.

   - bpo-36707(3): ‘./configure --with-pymalloc’ no longer adds the ‘m’
     flag to SOABI (sys.implementation.cache_tag).  Enabling or
     disabling pymalloc has no impact on the ABI.

   - bpo-36635(4): Change ‘PyAPI_FUNC(type)’, ‘PyAPI_DATA(type)’ and
     ‘PyMODINIT_FUNC’ macros of ‘pyport.h’ when ‘Py_BUILD_CORE_MODULE’
     is defined.  The ‘Py_BUILD_CORE_MODULE’ define must be now be used
     to build a C extension as a dynamic library accessing Python
     internals: export the ‘PyInit_XXX()’ function in DLL exports on
     Windows.

   - bpo-31904(5): Don’t build the ‘_crypt’ extension on VxWorks.

   - bpo-36618(6): Add ‘-fmax-type-align=8’ to CFLAGS when clang
     compiler is detected.  The pymalloc memory allocator aligns memory
     on 8 bytes.  On x86-64, clang expects alignment on 16 bytes by
     default and so uses MOVAPS instruction which can lead to
     segmentation fault.  Instruct clang that Python is limited to
     alignment on 8 bytes to use MOVUPS instruction instead: slower but
     don’t trigger a SIGSEGV if the memory is not aligned on 16 bytes.
     Sadly, the flag must be added to ‘CFLAGS’ and not just
     ‘CFLAGS_NODIST’, since third party C extensions can have the same
     issue.

   - bpo-36605(7): ‘make tags’ and ‘make TAGS’ now also parse
     ‘Modules/_io/*.c’ and ‘Modules/_io/*.h’.

   - bpo-36465(8): Release builds and debug builds are now ABI
     compatible: defining the ‘Py_DEBUG’ macro no longer implies the
     ‘Py_TRACE_REFS’ macro, which introduces the only ABI
     incompatibility.  The ‘Py_TRACE_REFS’ macro, which adds the *note
     sys.getobjects(): 28e. function and the *note PYTHONDUMPREFS: ba0.
     environment variable, can be set using the new ‘./configure
     --with-trace-refs’ build option.

   - bpo-36577(9): setup.py now correctly reports missing OpenSSL
     headers and libraries again.

   - bpo-36544(10): Fix regression introduced in bpo-36146(11)
     refactoring setup.py

   - bpo-36508(12): ‘python-config --ldflags’ no longer includes flags
     of the ‘LINKFORSHARED’ variable.  The ‘LINKFORSHARED’ variable must
     only be used to build executables.

   - bpo-36503(13): Remove references to «aix3» and «aix4».  Patch by M.
     Felt.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36747

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21536

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36707

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36635

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36618

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36605

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36465

   (9) https://bugs.python.org/issue?@action=redirect&bpo=36577

   (10) https://bugs.python.org/issue?@action=redirect&bpo=36544

   (11) https://bugs.python.org/issue?@action=redirect&bpo=36146

   (12) https://bugs.python.org/issue?@action=redirect&bpo=36508

   (13) https://bugs.python.org/issue?@action=redirect&bpo=36503


File: python.info,  Node: Windows<51>,  Next: macOS<40>,  Prev: Build<59>,  Up: Python 3 8 0 alpha 4

1.24.58.7 Windows
.................

   - bpo-35920(1): Added platform.win32_edition() and
     platform.win32_is_iot().  Added support for cross-compiling
     packages for Windows ARM32.  Skip tests that are not expected to
     work on Windows IoT Core ARM32.

   - bpo-36649(2): Remove trailing spaces for registry keys when
     installed via the Store.

   - bpo-34144(3): Fixed activate.bat to correctly update codepage when
     chcp.com returns dots in output.  Patch by Lorenz Mende.

   - bpo-36509(4): Added preset-iot layout for Windows IoT ARM
     containers.  This layout doesn’t contain UI components like tkinter
     or IDLE. It also doesn’t contain files to support on-target builds
     since Windows ARM32 builds must be cross-compiled when using MSVC.

   - bpo-35941(5): enum_certificates function of the ssl module now
     returns certificates from all available certificate stores inside
     windows in a query instead of returning only certificates from the
     system wide certificate store.  This includes certificates from
     these certificate stores: local machine, local machine enterprise,
     local machine group policy, current user, current user group
     policy, services, users.  ssl.enum_crls() function is changed in
     the same way to return all certificate revocation lists inside the
     windows certificate revocation list stores.

   - bpo-36441(6): Fixes creating a venv when debug binaries are
     installed.

   - bpo-36085(7): Enable better DLL resolution on Windows by using safe
     DLL search paths and adding *note os.add_dll_directory(): bdf.

   - bpo-36010(8): Add the venv standard library module to the nuget
     distribution for Windows.

   - bpo-29515(9): Add the following socket module constants on Windows:
     IPPROTO_AH IPPROTO_CBT IPPROTO_DSTOPTS IPPROTO_EGP IPPROTO_ESP
     IPPROTO_FRAGMENT IPPROTO_GGP IPPROTO_HOPOPTS IPPROTO_ICLFXBM
     IPPROTO_ICMPV6 IPPROTO_IDP IPPROTO_IGMP IPPROTO_IGP IPPROTO_IPV4
     IPPROTO_IPV6 IPPROTO_L2TP IPPROTO_MAX IPPROTO_ND IPPROTO_NONE
     IPPROTO_PGM IPPROTO_PIM IPPROTO_PUP IPPROTO_RDP IPPROTO_ROUTING
     IPPROTO_SCTP IPPROTO_ST

   - bpo-35947(10): Added current version of libffi to
     cpython-source-deps.  Change _ctypes to use current version of
     libffi on Windows.

   - bpo-34060(11): Report system load when running test suite on
     Windows.  Patch by Ammar Askar.  Based on prior work by Jeremy
     Kloth.

   - bpo-31512(12): With the Windows 10 Creators Update, non-elevated
     users can now create symlinks as long as the computer has Developer
     Mode enabled.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35920

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36649

   (3) https://bugs.python.org/issue?@action=redirect&bpo=34144

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36509

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35941

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36441

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36085

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36010

   (9) https://bugs.python.org/issue?@action=redirect&bpo=29515

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35947

   (11) https://bugs.python.org/issue?@action=redirect&bpo=34060

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31512


File: python.info,  Node: macOS<40>,  Next: IDLE<34>,  Prev: Windows<51>,  Up: Python 3 8 0 alpha 4

1.24.58.8 macOS
...............

   - bpo-34602(1): Avoid failures setting macOS stack resource limit
     with resource.setrlimit.  This reverts an earlier fix for
     bpo-18075(2) which forced a non-default stack size when building
     the interpreter executable on macOS.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34602

   (2) https://bugs.python.org/issue?@action=redirect&bpo=18075


File: python.info,  Node: IDLE<34>,  Next: Tools/Demos<35>,  Prev: macOS<40>,  Up: Python 3 8 0 alpha 4

1.24.58.9 IDLE
..............

   - bpo-36429(1): Fix starting IDLE with pyshell.  Add idlelib.pyshell
     alias at top; remove pyshell alias at bottom.  Remove obsolete
     __name__==”__main__” command.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36429


File: python.info,  Node: Tools/Demos<35>,  Next: C API<54>,  Prev: IDLE<34>,  Up: Python 3 8 0 alpha 4

1.24.58.10 Tools/Demos
......................

   - bpo-14546(1): Fix the argument handling in Tools/scripts/lll.py.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14546


File: python.info,  Node: C API<54>,  Prev: Tools/Demos<35>,  Up: Python 3 8 0 alpha 4

1.24.58.11 C API
................

   - bpo-36763(1): Fix memory leak in ‘Py_SetStandardStreamEncoding()’:
     release memory if the function is called twice.

   - bpo-36641(2): *note PyDoc_VAR: 1dd8.(name) and *note PyDoc_STRVAR:
     1d43.(name, str) now create ‘static const char name[]’ instead of
     ‘static char name[]’.  Patch by Inada Naoki.

   - bpo-36389(3): Change the value of ‘CLEANBYTE’, ‘DEADDYTE’ and
     ‘FORBIDDENBYTE’ internal constants used by debug hooks on Python
     memory allocators (*note PyMem_SetupDebugHooks(): e66. function).
     Byte patterns ‘0xCB’, ‘0xDB’ and ‘0xFB’ have been replaced with
     ‘0xCD’, ‘0xDD’ and ‘0xFD’ to use the same values than Windows CRT
     debug ‘malloc()’ and ‘free()’.

   - bpo-36443(4): Since Python 3.7.0, calling *note Py_DecodeLocale():
     dc2. before *note Py_Initialize(): 460. produces mojibake if the
     ‘LC_CTYPE’ locale is coerced and/or if the UTF-8 Mode is enabled by
     the user configuration.  The LC_CTYPE coercion and UTF-8 Mode are
     now disabled by default to fix the mojibake issue.  They must now
     be enabled explicitly (opt-in) using the new ‘_Py_PreInitialize()’
     API with ‘_PyPreConfig’.

   - bpo-36025(5): Fixed an accidental change to the datetime C API
     where the arguments to the *note PyDate_FromTimestamp(): 1dd9.
     function were incorrectly interpreted as a single timestamp rather
     than an arguments tuple, which causes existing code to start
     raising *note TypeError: 198.  The backwards-incompatible change
     was only present in alpha releases of Python 3.8.  Patch by Paul
     Ganssle.

   - bpo-35810(6): Modify ‘PyObject_Init’ to correctly increase the
     refcount of heap-allocated Type objects.  Also fix the refcounts of
     the heap-allocated types that were either doing this manually or
     not decreasing the type’s refcount in tp_dealloc

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36763

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36641

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36389

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36443

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36025

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35810


File: python.info,  Node: Python 3 8 0 alpha 3,  Next: Python 3 8 0 alpha 2,  Prev: Python 3 8 0 alpha 4,  Up: Changelog

1.24.59 Python 3.8.0 alpha 3
----------------------------

'Release date: 2019-03-25'

* Menu:

* Security: Security<45>.
* Core and Builtins: Core and Builtins<156>.
* Library: Library<159>.
* Documentation: Documentation<53>.
* Tests: Tests<52>.
* Build: Build<60>.
* Windows: Windows<52>.
* IDLE: IDLE<35>.
* Tools/Demos: Tools/Demos<36>.
* C API: C API<55>.


File: python.info,  Node: Security<45>,  Next: Core and Builtins<156>,  Up: Python 3 8 0 alpha 3

1.24.59.1 Security
..................

   - bpo-36216(1): Changes urlsplit() to raise ValueError when the URL
     contains characters that decompose under IDNA encoding
     (NFKC-normalization) into characters that affect how the URL is
     parsed.

   - bpo-35121(2): Don’t send cookies of domain A without Domain
     attribute to domain B when domain A is a suffix match of domain B
     while using a cookiejar with *note
     http.cookiejar.DefaultCookiePolicy: 1ddc. policy.  Patch by
     Karthikeyan Singaravelan.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36216

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35121


File: python.info,  Node: Core and Builtins<156>,  Next: Library<159>,  Prev: Security<45>,  Up: Python 3 8 0 alpha 3

1.24.59.2 Core and Builtins
...........................

   - bpo-36421(1): Fix a possible double decref in _ctypes.c’s
     ‘PyCArrayType_new()’.

   - bpo-36412(2): Fix a possible crash when creating a new dictionary.

   - bpo-36398(3): Fix a possible crash in ‘structseq_repr()’.

   - bpo-36256(4): Fix bug in parsermodule when parsing a state in a DFA
     that has two or more arcs with labels of the same type.  Patch by
     Pablo Galindo.

   - bpo-36365(5): repr(structseq) is no longer limited to 512 bytes.

   - bpo-36374(6): Fix a possible null pointer dereference in
     ‘merge_consts_recursive()’.  Patch by Zackery Spytz.

   - bpo-36236(7): At Python initialization, the current directory is no
     longer prepended to *note sys.path: 3e4. if it has been removed.

   - bpo-36352(8): Python initialization now fails with an error, rather
     than silently truncating paths, if a path is too long.

   - bpo-36301(9): Python initialization now fails if decoding
     ‘pybuilddir.txt’ configuration file fails at startup.

   - bpo-36333(10): Fix leak in _PyRuntimeState_Fini.  Contributed by
     Stéphane Wirtel.

   - bpo-36332(11): The builtin *note compile(): 4b2. can now handle AST
     objects that contain assignment expressions.  Patch by Pablo
     Galindo.

   - bpo-36282(12): Improved error message for too much positional
     arguments in some builtin functions.

   - bpo-30040(13): New empty dict uses fewer memory for now.  It used
     more memory than empty dict created by ‘dict.clear()’.  And empty
     dict creation and deletion is about 2x faster.  Patch by Inada
     Naoki.

   - bpo-36262(14): Fix an unlikely memory leak on conversion from
     string to float in the function ‘_Py_dg_strtod()’ used by
     ‘float(str)’, ‘complex(str)’, *note pickle.load(): f0e, *note
     marshal.load(): 1dde, etc.

   - bpo-36252(15): Update Unicode databases to version 12.0.0.

   - bpo-36218(16): Fix a segfault occurring when sorting a list of
     heterogeneous values.  Patch contributed by Rémi Lapeyre and Elliot
     Gorokhovsky.

   - bpo-36188(17): Cleaned up left-over vestiges of Python 2 unbound
     method handling in method objects and documentation.  Patch by
     Martijn Pieters

   - bpo-36124(18): Add a new interpreter-specific dict and expose it in
     the C-API via PyInterpreterState_GetDict().  This parallels
     PyThreadState_GetDict().  However, extension modules should
     continue using PyModule_GetState() for their own internal
     per-interpreter state.

   - bpo-35975(19): Add a ‘feature_version’ flag to ‘ast.parse()’
     (documented) and ‘compile()’ (hidden) that allows tweaking the
     parser to support older versions of the grammar.  In particular, if
     ‘feature_version’ is 5 or 6, the hacks for the ‘async’ and ‘await’
     keyword from PEP 492 are reinstated.  (For 7 or higher, these are
     unconditionally treated as keywords, but they are still special
     tokens rather than ‘NAME’ tokens that the parser driver
     recognizes.)

   - bpo-31904(20): Use UTF-8 as the system encoding on VxWorks.

   - bpo-36048(21): The *note __index__(): 19e. special method will be
     used instead of *note __int__(): 19d. for implicit conversion of
     Python numbers to C integers.  Using the ‘__int__()’ method in
     implicit conversions has been deprecated.

   - bpo-35808(22): Retire pgen and use a modified version of pgen2 to
     generate the parser.  Patch by Pablo Galindo.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36421

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36412

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36398

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36256

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36365

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36374

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36236

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36352

   (9) https://bugs.python.org/issue?@action=redirect&bpo=36301

   (10) https://bugs.python.org/issue?@action=redirect&bpo=36333

   (11) https://bugs.python.org/issue?@action=redirect&bpo=36332

   (12) https://bugs.python.org/issue?@action=redirect&bpo=36282

   (13) https://bugs.python.org/issue?@action=redirect&bpo=30040

   (14) https://bugs.python.org/issue?@action=redirect&bpo=36262

   (15) https://bugs.python.org/issue?@action=redirect&bpo=36252

   (16) https://bugs.python.org/issue?@action=redirect&bpo=36218

   (17) https://bugs.python.org/issue?@action=redirect&bpo=36188

   (18) https://bugs.python.org/issue?@action=redirect&bpo=36124

   (19) https://bugs.python.org/issue?@action=redirect&bpo=35975

   (20) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (21) https://bugs.python.org/issue?@action=redirect&bpo=36048

   (22) https://bugs.python.org/issue?@action=redirect&bpo=35808


File: python.info,  Node: Library<159>,  Next: Documentation<53>,  Prev: Core and Builtins<156>,  Up: Python 3 8 0 alpha 3

1.24.59.3 Library
.................

   - bpo-36401(1): The class documentation created by pydoc now has a
     separate section for readonly properties.

   - bpo-36320(2): The typing.NamedTuple() class has deprecated the
     _field_types attribute in favor of the __annotations__ attribute
     which carried the same information.  Also, both attributes were
     converted from OrderedDict to a regular dict.

   - bpo-34745(3): Fix *note asyncio: b. ssl memory issues caused by
     circular references

   - bpo-36324(4): Add method to statistics.NormalDist for computing the
     inverse cumulative normal distribution.

   - bpo-36321(5): collections.namedtuple() misspelled the name of an
     attribute.  To be consistent with typing.NamedTuple, the attribute
     name should have been «_field_defaults» instead of
     «_fields_defaults».  For backwards compatibility, both spellings
     are now created.  The misspelled version may be removed in the
     future.

   - bpo-36297(6): «unicode_internal» codec is removed.  It was
     deprecated since Python 3.3.  Patch by Inada Naoki.

   - bpo-36298(7): Raise ModuleNotFoundError in pyclbr when a module
     can’t be found.  Thanks to “mental” for the bug report.

   - bpo-36268(8): Switch the default format used for writing tars with
     *note tarfile: e4. to the modern POSIX.1-2001 pax standard, from
     the vendor-specific GNU. Contributed by C.A.M. Gerlach.

   - bpo-36285(9): Fix integer overflows in the array module.  Patch by
     Stephan Hohe.

   - bpo-31904(10): Add _signal module support for VxWorks.

   - bpo-36272(11): *note logging: 8b. does not silently ignore
     RecursionError anymore.  Patch contributed by Rémi Lapeyre.

   - bpo-36280(12): Add a kind field to ast.Constant.  It is “u” if the
     literal has a “u” prefix (i.e.  a Python 2 style unicode literal),
     else None.

   - bpo-35931(13): The *note pdb: aa. ‘debug’ command now gracefully
     handles all exceptions.

   - bpo-36251(14): Fix format strings used for stderrprinter and
     re.Match reprs.  Patch by Stephan Hohe.

   - bpo-36235(15): Fix ‘CFLAGS’ in ‘customize_compiler()’ of
     ‘distutils.sysconfig’: when the ‘CFLAGS’ environment variable is
     defined, don’t override ‘CFLAGS’ variable with the ‘OPT’ variable
     anymore.  Initial patch written by David Malcolm.

   - bpo-35807(16): Update ensurepip to install pip 19.0.3 and
     setuptools 40.8.0.

   - bpo-36139(17): Release GIL when closing *note mmap: 51a. objects.

   - bpo-36179(18): Fix two unlikely reference leaks in _hashopenssl.
     The leaks only occur in out-of-memory cases.

   - bpo-36169(19): Add overlap() method to statistics.NormalDist.
     Computes the overlapping coefficient for two normal distributions.

   - bpo-36103(20): Default buffer size used by ‘shutil.copyfileobj()’
     is changed from 16 KiB to 64 KiB on non-Windows platform to reduce
     system call overhead.  Contributed by Inada Naoki.

   - bpo-36130(21): Fix ‘pdb’ with ‘skip=...’ when stepping into a frame
     without a ‘__name__’ global.  Patch by Anthony Sottile.

   - bpo-35652(22): shutil.copytree(copy_function=…) erroneously pass
     DirEntry instead of a path string.

   - bpo-35178(23): Ensure custom *note warnings.formatwarning(): 1de0.
     function can receive ‘line’ as positional argument.  Based on patch
     by Tashrif Billah.

   - bpo-36106(24): Resolve potential name clash with libm’s sinpi().
     Patch by Dmitrii Pasechnik.

   - bpo-36091(25): Clean up reference to async generator in Lib/types.
     Patch by Henry Chen.

   - bpo-36043(26): ‘FileCookieJar’ supports *note path-like object:
     5a1.  Contributed by Stéphane Wirtel

   - bpo-35899(27): Enum has been fixed to correctly handle empty
     strings and strings with non-Latin characters (ie.  “α”, “א”)
     without crashing.  Original patch contributed by Maxwell.  Assisted
     by Stéphane Wirtel.

   - bpo-21269(28): Add ‘args’ and ‘kwargs’ properties to mock call
     objects.  Contributed by Kumar Akshay.

   - bpo-30670(29): ‘pprint.pp’ has been added to pretty-print objects
     with dictionary keys being sorted with their insertion order by
     default.  Parameter 'sort_dicts' has been added to ‘pprint.pprint’,
     ‘pprint.pformat’ and ‘pprint.PrettyPrinter’.  Contributed by Rémi
     Lapeyre.

   - bpo-35843(30): Implement ‘__getitem__’ for ‘_NamespacePath’.  Patch
     by Anthony Sottile.

   - bpo-35802(31): Clean up code which checked presence of ‘os.stat’ /
     ‘os.lstat’ / ‘os.chmod’ which are always present.  Patch by Anthony
     Sottile.

   - bpo-35715(32): Librates the return value of a ProcessPoolExecutor
     _process_worker after it’s no longer needed to free memory

   - bpo-35493(33): Use *note multiprocessing.connection.wait(): 12e7.
     instead of polling each 0.2 seconds for worker updates in
     ‘multiprocessing.Pool’.  Patch by Pablo Galindo.

   - bpo-35661(34): Store the venv prompt in pyvenv.cfg.

   - bpo-35121(35): Don’t set cookie for a request when the request path
     is a prefix match of the cookie’s path attribute but doesn’t end
     with «/».  Patch by Karthikeyan Singaravelan.

   - bpo-21478(36): Calls to a child function created with *note
     unittest.mock.create_autospec(): 191c. should propagate to the
     parent.  Patch by Karthikeyan Singaravelan.

   - bpo-35198(37): Fix C++ extension compilation on AIX

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36401

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36320

   (3) https://bugs.python.org/issue?@action=redirect&bpo=34745

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36324

   (5) https://bugs.python.org/issue?@action=redirect&bpo=36321

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36297

   (7) https://bugs.python.org/issue?@action=redirect&bpo=36298

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36268

   (9) https://bugs.python.org/issue?@action=redirect&bpo=36285

   (10) https://bugs.python.org/issue?@action=redirect&bpo=31904

   (11) https://bugs.python.org/issue?@action=redirect&bpo=36272

   (12) https://bugs.python.org/issue?@action=redirect&bpo=36280

   (13) https://bugs.python.org/issue?@action=redirect&bpo=35931

   (14) https://bugs.python.org/issue?@action=redirect&bpo=36251

   (15) https://bugs.python.org/issue?@action=redirect&bpo=36235

   (16) https://bugs.python.org/issue?@action=redirect&bpo=35807

   (17) https://bugs.python.org/issue?@action=redirect&bpo=36139

   (18) https://bugs.python.org/issue?@action=redirect&bpo=36179

   (19) https://bugs.python.org/issue?@action=redirect&bpo=36169

   (20) https://bugs.python.org/issue?@action=redirect&bpo=36103

   (21) https://bugs.python.org/issue?@action=redirect&bpo=36130

   (22) https://bugs.python.org/issue?@action=redirect&bpo=35652

   (23) https://bugs.python.org/issue?@action=redirect&bpo=35178

   (24) https://bugs.python.org/issue?@action=redirect&bpo=36106

   (25) https://bugs.python.org/issue?@action=redirect&bpo=36091

   (26) https://bugs.python.org/issue?@action=redirect&bpo=36043

   (27) https://bugs.python.org/issue?@action=redirect&bpo=35899

   (28) https://bugs.python.org/issue?@action=redirect&bpo=21269

   (29) https://bugs.python.org/issue?@action=redirect&bpo=30670

   (30) https://bugs.python.org/issue?@action=redirect&bpo=35843

   (31) https://bugs.python.org/issue?@action=redirect&bpo=35802

   (32) https://bugs.python.org/issue?@action=redirect&bpo=35715

   (33) https://bugs.python.org/issue?@action=redirect&bpo=35493

   (34) https://bugs.python.org/issue?@action=redirect&bpo=35661

   (35) https://bugs.python.org/issue?@action=redirect&bpo=35121

   (36) https://bugs.python.org/issue?@action=redirect&bpo=21478

   (37) https://bugs.python.org/issue?@action=redirect&bpo=35198


File: python.info,  Node: Documentation<53>,  Next: Tests<52>,  Prev: Library<159>,  Up: Python 3 8 0 alpha 3

1.24.59.4 Documentation
.......................

   - bpo-36329(1): Declare the path of the Python binary for the usage
     of ‘Tools/scripts/serve.py’ when executing ‘make -C Doc/ serve’.
     Contributed by Stéphane Wirtel

   - bpo-36138(2): Improve documentation about converting
     datetime.timedelta to scalars.

   - bpo-21314(3): A new entry was added to the Core Language Section of
     the Programming FAQ, which explaines the usage of slash(/) in the
     signature of a function.  Patch by Lysandros Nikolaou

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36329

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36138

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21314


File: python.info,  Node: Tests<52>,  Next: Build<60>,  Prev: Documentation<53>,  Up: Python 3 8 0 alpha 3

1.24.59.5 Tests
...............

   - bpo-36234(1): test_posix.PosixUidGidTests: add tests for invalid
     uid/gid type (str).  Initial patch written by David Malcolm.

   - bpo-29571(2): Fix ‘test_re.test_locale_flag()’: use
     ‘locale.getpreferredencoding()’ rather than ‘locale.getlocale()’ to
     get the locale encoding.  With some locales, ‘locale.getlocale()’
     returns the wrong encoding.

   - bpo-36123(3): Fix race condition in test_socket.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36234

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29571

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36123


File: python.info,  Node: Build<60>,  Next: Windows<52>,  Prev: Tests<52>,  Up: Python 3 8 0 alpha 3

1.24.59.6 Build
...............

   - bpo-36356(1): Fix leaks that led to build failure when configured
     with address sanitizer.

   - bpo-36146(2): Add ‘TEST_EXTENSIONS’ constant to ‘setup.py’ to allow
     to not build test extensions like ‘_testcapi’.

   - bpo-36146(3): Fix setup.py on macOS: only add ‘/usr/include/ffi’ to
     include directories of _ctypes, not for all extensions.

   - bpo-31904(4): Enable build system to cross-build for VxWorks RTOS.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36356

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36146

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36146

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31904


File: python.info,  Node: Windows<52>,  Next: IDLE<35>,  Prev: Build<60>,  Up: Python 3 8 0 alpha 3

1.24.59.7 Windows
.................

   - bpo-36312(1): Fixed decoders for the following code pages: 50220,
     50221, 50222, 50225, 50227, 50229, 57002 through 57011, 65000 and
     42.

   - bpo-36264(2): Don’t honor POSIX ‘HOME’ in ‘os.path.expanduser’ on
     windows.  Patch by Anthony Sottile.

   - bpo-24643(3): Fix name collisions due to ‘#define timezone
     _timezone’ in PC/pyconfig.h.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36312

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36264

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24643


File: python.info,  Node: IDLE<35>,  Next: Tools/Demos<36>,  Prev: Windows<52>,  Up: Python 3 8 0 alpha 3

1.24.59.8 IDLE
..............

   - bpo-36405(1): Use dict unpacking in idlelib.

   - bpo-36396(2): Remove fgBg param of idlelib.config.GetHighlight().
     This param was only used twice and changed the return type.

   - bpo-36176(3): Fix IDLE autocomplete & calltip popup colors.
     Prevent conflicts with Linux dark themes (and slightly darken
     calltip background).

   - bpo-23205(4): For the grep module, add tests for findfiles,
     refactor findfiles to be a module-level function, and refactor
     findfiles to use os.walk.

   - bpo-23216(5): Add docstrings to IDLE search modules.

   - bpo-36152(6): Remove colorizer.ColorDelegator.close_when_done and
     the corresponding argument of .close().  In IDLE, both have always
     been None or False since 2007.

   - bpo-32129(7): Avoid blurry IDLE application icon on macOS with Tk
     8.6.  Patch by Kevin Walzer.

   - bpo-36096(8): Refactor class variables to instance variables in
     colorizer.

   - bpo-30348(9): Increase test coverage of idlelib.autocomplete by
     30%.  Patch by Louie Lu

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36405

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36396

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36176

   (4) https://bugs.python.org/issue?@action=redirect&bpo=23205

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23216

   (6) https://bugs.python.org/issue?@action=redirect&bpo=36152

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32129

   (8) https://bugs.python.org/issue?@action=redirect&bpo=36096

   (9) https://bugs.python.org/issue?@action=redirect&bpo=30348


File: python.info,  Node: Tools/Demos<36>,  Next: C API<55>,  Prev: IDLE<35>,  Up: Python 3 8 0 alpha 3

1.24.59.9 Tools/Demos
.....................

   - bpo-35132(1): Fix py-list and py-bt commands of python-gdb.py on
     gdb7.

   - bpo-32217(2): Fix freeze script on Windows.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35132

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32217


File: python.info,  Node: C API<55>,  Prev: Tools/Demos<36>,  Up: Python 3 8 0 alpha 3

1.24.59.10 C API
................

   - bpo-36381(1): Raise ‘DeprecationWarning’ when “#” formats are used
     for building or parsing values without ‘PY_SSIZE_T_CLEAN’.

   - bpo-36142(2): The whole coreconfig.h header is now excluded from
     Py_LIMITED_API. Move functions definitions into a new internal
     pycore_coreconfig.h header.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36381

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36142


File: python.info,  Node: Python 3 8 0 alpha 2,  Next: Python 3 8 0 alpha 1,  Prev: Python 3 8 0 alpha 3,  Up: Changelog

1.24.60 Python 3.8.0 alpha 2
----------------------------

'Release date: 2019-02-25'

* Menu:

* Core and Builtins: Core and Builtins<157>.
* Library: Library<160>.
* Documentation: Documentation<54>.
* Tests: Tests<53>.
* Windows: Windows<53>.
* IDLE: IDLE<36>.


File: python.info,  Node: Core and Builtins<157>,  Next: Library<160>,  Up: Python 3 8 0 alpha 2

1.24.60.1 Core and Builtins
...........................

   - bpo-36052(1): Raise a *note SyntaxError: 18e. when assigning a
     value to ‘__debug__’ with the Assignment Operator.  Contributed by
     Stéphane Wirtel and Pablo Galindo.

   - bpo-36012(2): Doubled the speed of class variable writes.  When a
     non-dunder attribute was updated, there was an unnecessary call to
     update slots.

   - bpo-35942(3): The error message emitted when returning invalid
     types from ‘__fspath__’ in interfaces that allow passing *note
     PathLike: e4d. objects has been improved and now it does explain
     the origin of the error.

   - bpo-36016(4): ‘gc.get_objects’ can now receive an optional
     parameter indicating a generation to get objects from.  Patch by
     Pablo Galindo.

   - bpo-1054041(5): When the main interpreter exits due to an uncaught
     KeyboardInterrupt, the process now exits in the appropriate manner
     for its parent process to detect that a SIGINT or ^C terminated the
     process.  This allows shells and batch scripts to understand that
     the user has asked them to stop.

   - bpo-35992(6): Fix ‘__class_getitem__()’ not being called on a class
     with a custom non-subscriptable metaclass.

   - bpo-35993(7): Fix a crash on fork when using subinterpreters.
     Contributed by Stéphane Wirtel

   - bpo-35991(8): Fix a potential double free in
     Modules/_randommodule.c.

   - bpo-35961(9): Fix a crash in slice_richcompare(): use strong
     references rather than stolen references for the two temporary
     internal tuples.

   - bpo-35911(10): Enable the creation of cell objects by adding a
     ‘cell.__new__’ method, and expose the type ‘cell’ in ‘Lib/types.py’
     under the name CellType.  Patch by Pierre Glaser.

   - bpo-12822(11): Use monotonic clock for ‘pthread_cond_timedwait’
     when ‘pthread_condattr_setclock’ and ‘CLOCK_MONOTONIC’ are
     available.

   - bpo-15248(12): The compiler emits now syntax warnings in the case
     when a comma is likely missed before tuple or list.

   - bpo-35886(13): The implementation of PyInterpreterState has been
     moved into the internal header files (guarded by Py_BUILD_CORE).

   - bpo-31506(14): Clarify the errors reported when ‘object.__new__’
     and ‘object.__init__’ receive more than one argument.  Contributed
     by Sanyam Khurana.

   - bpo-35724(15): Signal-handling is now guaranteed to happen relative
     to the main interpreter.

   - bpo-33608(16): We added a new internal _Py_AddPendingCall() that
     operates relative to the provided interpreter.  This allows us to
     use the existing implementation to ask another interpreter to do
     work that cannot be done in the current interpreter, like decref an
     object the other interpreter owns.  The existing
     Py_AddPendingCall() only operates relative to the main interpreter.

   - bpo-33989(17): Fix a possible crash in *note list.sort(): dca. when
     sorting objects with ‘ob_type->tp_richcompare == NULL’.  Patch by
     Zackery Spytz.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36052

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36012

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35942

   (4) https://bugs.python.org/issue?@action=redirect&bpo=36016

   (5) https://bugs.python.org/issue?@action=redirect&bpo=1054041

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35992

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35993

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35991

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35961

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35911

   (11) https://bugs.python.org/issue?@action=redirect&bpo=12822

   (12) https://bugs.python.org/issue?@action=redirect&bpo=15248

   (13) https://bugs.python.org/issue?@action=redirect&bpo=35886

   (14) https://bugs.python.org/issue?@action=redirect&bpo=31506

   (15) https://bugs.python.org/issue?@action=redirect&bpo=35724

   (16) https://bugs.python.org/issue?@action=redirect&bpo=33608

   (17) https://bugs.python.org/issue?@action=redirect&bpo=33989


File: python.info,  Node: Library<160>,  Next: Documentation<54>,  Prev: Core and Builtins<157>,  Up: Python 3 8 0 alpha 2

1.24.60.2 Library
.................

   - bpo-35512(1): *note unittest.mock.patch.dict(): 194f. used as a
     decorator with string target resolves the target during function
     call instead of during decorator construction.  Patch by
     Karthikeyan Singaravelan.

   - bpo-36018(2): Add statistics.NormalDist, a tool for creating and
     manipulating normal distributions of random variable.  Features a
     composite class that treats the mean and standard deviation of
     measurement data as single entity.

   - bpo-35904(3): Added statistics.fmean() as a faster, floating-point
     variant of the existing mean() function.

   - bpo-35918(4): Removed broken ‘has_key’ method from
     multiprocessing.managers.SyncManager.dict.  Contributed by Rémi
     Lapeyre.

   - bpo-18283(5): Add support for bytes to *note shutil.which(): 6dc.

   - bpo-35960(6): Fix *note dataclasses.field(): 1942. throwing away
     empty mapping objects passed as metadata.

   - bpo-35500(7): Write expected and actual call parameters on separate
     lines in *note unittest.mock.Mock.assert_called_with(): 1deb.
     assertion errors.  Contributed by Susan Su.

   - bpo-35931(8): The *note pdb: aa. ‘debug’ command now gracefully
     handles syntax errors.

   - bpo-24209(9): In http.server script, rely on getaddrinfo to bind to
     preferred address based on the bind parameter.  Now default bind or
     binding to a name may bind to IPv6 or dual-stack, depending on the
     environment.

   - bpo-35321(10): Set ‘__spec__.origin’ of ‘_frozen_importlib’ to
     frozen so that it matches the behavior of
     ‘_frozen_importlib_external’.  Patch by Nina Zakharenko.

   - bpo-35378(11): Fix a reference issue inside ‘multiprocessing.Pool’
     that caused the pool to remain alive if it was deleted without
     being closed or terminated explicitly.  A new strong reference is
     added to the pool iterators to link the lifetime of the pool to the
     lifetime of its iterators so the pool does not get destroyed if a
     pool iterator is still alive.

   - bpo-34294(12): re module, fix wrong capturing groups in rare cases.
     *note re.search(): 1434, *note re.findall(): 122c, *note re.sub():
     5a3. and other functions that scan through string looking for a
     match, should reset capturing groups between two match attempts.
     Patch by Ma Lin.

   - bpo-35615(13): *note weakref: 11a.: Fix a RuntimeError when copying
     a WeakKeyDictionary or a WeakValueDictionary, due to some keys or
     values disappearing while iterating.

   - bpo-35606(14): Implement *note math.prod(): bf9. as analogous
     function to *note sum(): 696. that returns the product of a “start”
     value (default: 1) times an iterable of numbers.  Patch by Pablo
     Galindo.

   - bpo-32417(15): Performing arithmetic between *note
     datetime.datetime: 4e3. subclasses and *note datetime.timedelta:
     bc5. now returns an object of the same type as the *note
     datetime.datetime: 4e3. subclass.  As a result, *note
     datetime.datetime.astimezone(): bc6. and alternate constructors
     like *note datetime.datetime.now(): 712. and
     ‘datetime.fromtimestamp()’ called with a ‘tz’ argument now 'also'
     retain their subclass.

   - bpo-35153(16): Add 'headers' optional keyword-only parameter to
     *note xmlrpc.client.ServerProxy: c4e, ‘xmlrpc.client.Transport’ and
     ‘xmlrpc.client.SafeTransport’.  Patch by Cédric Krier.

   - bpo-34572(17): Fix C implementation of pickle.loads to use
     importlib’s locking mechanisms, and thereby avoid using partially
     loaded modules.  Patch by Tim Burgess.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35512

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36018

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35904

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35918

   (5) https://bugs.python.org/issue?@action=redirect&bpo=18283

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35960

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35500

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35931

   (9) https://bugs.python.org/issue?@action=redirect&bpo=24209

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35321

   (11) https://bugs.python.org/issue?@action=redirect&bpo=35378

   (12) https://bugs.python.org/issue?@action=redirect&bpo=34294

   (13) https://bugs.python.org/issue?@action=redirect&bpo=35615

   (14) https://bugs.python.org/issue?@action=redirect&bpo=35606

   (15) https://bugs.python.org/issue?@action=redirect&bpo=32417

   (16) https://bugs.python.org/issue?@action=redirect&bpo=35153

   (17) https://bugs.python.org/issue?@action=redirect&bpo=34572


File: python.info,  Node: Documentation<54>,  Next: Tests<53>,  Prev: Library<160>,  Up: Python 3 8 0 alpha 2

1.24.60.3 Documentation
.......................

   - bpo-36083(1): Fix formatting of –check-hash-based-pycs options in
     the manpage Synopsis.

   - bpo-36007(2): Bump minimum sphinx version to 1.8.  Patch by Anthony
     Sottile.

   - bpo-22062(3): Update documentation and docstrings for pathlib.
     Original patch by Mike Short.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=36083

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36007

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22062


File: python.info,  Node: Tests<53>,  Next: Windows<53>,  Prev: Documentation<54>,  Up: Python 3 8 0 alpha 2

1.24.60.4 Tests
...............

   - bpo-27313(1): Avoid test_ttk_guionly ComboboxTest failure with
     macOS Cocoa Tk.

   - bpo-36019(2): Add test.support.TEST_HTTP_URL and replace references
     of ‘http://www.example.com’ by this new constant.  Contributed by
     Stéphane Wirtel.

   - bpo-36037(3): Fix test_ssl for strict OpenSSL configuration like
     RHEL8 strict crypto policy.  Use older TLS version for minimum TLS
     version of the server SSL context if needed, to test TLS version
     older than default minimum TLS version.

   - bpo-35798(4): Added ‘test.support.check_syntax_warning()’.

   - bpo-35505(5): Make test_imap4_host_default_value independent on
     whether the local IMAP server is running.

   - bpo-35917(6): multiprocessing: provide unit tests for SyncManager
     and SharedMemoryManager classes + all the shareable types which are
     supposed to be supported by them.  (patch by Giampaolo Rodola)

   - bpo-35704(7): Skip ‘test_shutil.test_unpack_archive_xztar’ to
     prevent a MemoryError on 32-bit AIX when MAXDATA setting is less
     than 0x20000000.

     Patch by Michael Felt (aixtools)

   - bpo-34720(8): Assert m_state != NULL to mimic GC traversal
     functions that do not correctly handle module creation when the
     module state has not been created.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27313

   (2) https://bugs.python.org/issue?@action=redirect&bpo=36019

   (3) https://bugs.python.org/issue?@action=redirect&bpo=36037

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35798

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35505

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35917

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35704

   (8) https://bugs.python.org/issue?@action=redirect&bpo=34720


File: python.info,  Node: Windows<53>,  Next: IDLE<36>,  Prev: Tests<53>,  Up: Python 3 8 0 alpha 2

1.24.60.5 Windows
.................

   - bpo-35976(1): Added ARM build support to Windows build files in
     PCBuild.

   - bpo-35692(2): ‘pathlib’ no longer raises when checking file and
     directory existence on drives that are not ready

   - bpo-35872(3): Uses the base Python executable when invoking venv in
     a virtual environment

   - bpo-35873(4): Prevents venv paths being inherited by child
     processes

   - bpo-35299(5): Fix sysconfig detection of the source directory and
     distutils handling of pyconfig.h during PGO profiling

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35976

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35692

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35872

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35873

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35299


File: python.info,  Node: IDLE<36>,  Prev: Windows<53>,  Up: Python 3 8 0 alpha 2

1.24.60.6 IDLE
..............

   - bpo-24310(1): IDLE – Document settings dialog font tab sample.

   - bpo-35833(2): Revise IDLE doc for control codes sent to Shell.  Add
     a code example block.

   - bpo-35689(3): Add docstrings and unittests for colorizer.py.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24310

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35833

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35689


File: python.info,  Node: Python 3 8 0 alpha 1,  Next: Python 3 7 0 final,  Prev: Python 3 8 0 alpha 2,  Up: Changelog

1.24.61 Python 3.8.0 alpha 1
----------------------------

'Release date: 2019-02-03'

* Menu:

* Security: Security<46>.
* Core and Builtins: Core and Builtins<158>.
* Library: Library<161>.
* Documentation: Documentation<55>.
* Tests: Tests<54>.
* Build: Build<61>.
* Windows: Windows<54>.
* macOS: macOS<41>.
* IDLE: IDLE<37>.
* Tools/Demos: Tools/Demos<37>.
* C API: C API<56>.


File: python.info,  Node: Security<46>,  Next: Core and Builtins<158>,  Up: Python 3 8 0 alpha 1

1.24.61.1 Security
..................

   - bpo-35746(1): CVE 2019-5010(2): Fix a NULL pointer deref in ssl
     module.  The cert parser did not handle CRL distribution points
     with empty DP or URI correctly.  A malicious or buggy certificate
     can result into segfault.  Vulnerability (TALOS-2018-0758) reported
     by Colin Read and Nicolas Edet of Cisco.

   - bpo-34812(3): The *note -I: b59. command line option (run Python in
     isolated mode) is now also copied by the *note multiprocessing: 98.
     and ‘distutils’ modules when spawning child processes.  Previously,
     only *note -E: b58. and *note -s: 1596. options (enabled by *note
     -I: b59.) were copied.

   - bpo-34791(4): The xml.sax and xml.dom.domreg no longer use
     environment variables to override parser implementations when
     sys.flags.ignore_environment is set by -E or -I arguments.

   - bpo-17239(5): The xml.sax and xml.dom.minidom parsers no longer
     processes external entities by default.  External DTD and ENTITY
     declarations no longer load files or create network connections.

   - bpo-34623(6): CVE 2018-14647(7): The C accelerated _elementtree
     module now initializes hash randomization salt from _Py_HashSecret
     instead of libexpat’s default CSPRNG.

   - bpo-34405(8): Updated to OpenSSL 1.1.0i for Windows builds.

   - bpo-33871(9): Fixed sending the part of the file in *note
     os.sendfile(): d07. on macOS. Using the 'trailers' argument could
     cause sending more bytes from the input file than was specified.

   - bpo-32533(10): Fixed thread-safety of error handling in _ssl.

   - bpo-33136(11): Harden ssl module against LibreSSL CVE
     2018-8970(12).  X509_VERIFY_PARAM_set1_host() is called with an
     explicit namelen.  A new test ensures that NULL bytes are not
     allowed.

   - bpo-33001(13): Minimal fix to prevent buffer overrun in os.symlink
     on Windows

   - bpo-32981(14): Regexes in difflib and poplib were vulnerable to
     catastrophic backtracking.  These regexes formed potential DOS
     vectors (REDOS). They have been refactored.  This resolves CVE
     2018-1060(15) and CVE 2018-1061(16).  Patch by Jamie Davis.

   - bpo-28414(17): The ssl module now allows users to perform their own
     IDN en/decoding when using SNI.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35746

   (2) https://www.cve.org/CVERecord?id=CVE-2019-5010

   (3) https://bugs.python.org/issue?@action=redirect&bpo=34812

   (4) https://bugs.python.org/issue?@action=redirect&bpo=34791

   (5) https://bugs.python.org/issue?@action=redirect&bpo=17239

   (6) https://bugs.python.org/issue?@action=redirect&bpo=34623

   (7) https://www.cve.org/CVERecord?id=CVE-2018-14647

   (8) https://bugs.python.org/issue?@action=redirect&bpo=34405

   (9) https://bugs.python.org/issue?@action=redirect&bpo=33871

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32533

   (11) https://bugs.python.org/issue?@action=redirect&bpo=33136

   (12) https://www.cve.org/CVERecord?id=CVE-2018-8970

   (13) https://bugs.python.org/issue?@action=redirect&bpo=33001

   (14) https://bugs.python.org/issue?@action=redirect&bpo=32981

   (15) https://www.cve.org/CVERecord?id=CVE-2018-1060

   (16) https://www.cve.org/CVERecord?id=CVE-2018-1061

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28414


File: python.info,  Node: Core and Builtins<158>,  Next: Library<161>,  Prev: Security<46>,  Up: Python 3 8 0 alpha 1

1.24.61.2 Core and Builtins
...........................

   - bpo-35877(1): Make parenthesis optional for named expressions in
     while statement.  Patch by Karthikeyan Singaravelan.

   - bpo-35814(2): Allow same right hand side expressions in annotated
     assignments as in normal ones.  In particular, ‘x: Tuple[int, int]
     = 1, 2’ (without parentheses on the right) is now allowed.

   - bpo-35766(3): Add the option to parse PEP 484 type comments in the
     ast module.  (Off by default.)  This is merging the key
     functionality of the third party fork thereof,
     [typed_ast](‘https://github.com/python/typed_ast’).

   - bpo-35713(4): Reorganize Python initialization to get working
     exceptions and sys.stderr earlier.

   - bpo-33416(5): Add end line and end column position information to
     the Python AST nodes.  This is a C-level backwards incompatible
     change.

   - bpo-35720(6): Fixed a minor memory leak in
     pymain_parse_cmdline_impl function in Modules/main.c

   - bpo-35634(7): ‘func(**kwargs)’ will now raise an error when
     ‘kwargs’ is a mapping containing multiple entries with the same
     key.  An error was already raised when other keyword arguments are
     passed before ‘**kwargs’ since Python 3.6.

   - bpo-35623(8): Fix a crash when sorting very long lists.  Patch by
     Stephan Hohe.

   - bpo-35214(9): clang Memory Sanitizer build instrumentation was
     added to work around false positives from posix, socket, time,
     test_io, and test_faulthandler.

   - bpo-35560(10): Fix an assertion error in *note format(): 199. in
     debug build for floating-point formatting with «n» format, zero
     padding and small width.  Release build is not impacted.  Patch by
     Karthikeyan Singaravelan.

   - bpo-35552(11): Format characters ‘%s’ and ‘%V’ in *note
     PyUnicode_FromFormat(): 62b. and ‘%s’ in *note
     PyBytes_FromFormat(): 1df3. no longer read memory past the limit if
     'precision' is specified.

   - bpo-35504(12): Fix segfaults and *note SystemError: 796.s when
     deleting certain attributes.  Patch by Zackery Spytz.

   - bpo-35504(13): Fixed a SystemError when delete the
     characters_written attribute of an OSError.

   - bpo-35494(14): Improved syntax error messages for unbalanced
     parentheses in f-string.

   - bpo-35444(15): Fixed error handling in pickling methods when fail
     to look up builtin «getattr».  Sped up pickling iterators.

   - bpo-35436(16): Fix various issues with memory allocation error
     handling.  Patch by Zackery Spytz.

   - bpo-35423(17): Separate the signal handling trigger in the eval
     loop from the «pending calls» machinery.  There is no semantic
     change and the difference in performance is insignificant.

   - bpo-35357(18): Internal attributes” names of unittest.mock._Call
     and unittest.mock.MagicProxy (name, parent & from_kall) are now
     prefixed with _mock_ in order to prevent clashes with widely used
     object attributes.  Fixed minor typo in test function name.

   - bpo-35372(19): Fixed the code page decoder for input longer than 2
     GiB containing undecodable bytes.

   - bpo-35336(20): Fix PYTHONCOERCECLOCALE=1 environment variable: only
     coerce the C locale if the LC_CTYPE locale is «C».

   - bpo-31241(21): The 'lineno' and 'col_offset' attributes of AST
     nodes for list comprehensions, generator expressions and tuples are
     now point to the opening parenthesis or square brace.  For tuples
     without parenthesis they point to the position of the first item.

   - bpo-33954(22): For *note str.format(): 834, ‘float.__format__()’
     and ‘complex.__format__()’ methods for non-ASCII decimal point when
     using the «n» formatter.

   - bpo-35269(23): Fix a possible segfault involving a newly created
     coroutine.  Patch by Zackery Spytz.

   - bpo-35224(24): Implement PEP 572(25) (assignment expressions).
     Patch by Emily Morehouse.

   - bpo-32492(26): Speed up ‘namedtuple()’ attribute access by 1.6x
     using a C fast-path for the name descriptors.  Patch by Pablo
     Galindo.

   - bpo-35214(27): Fixed an out of bounds memory access when parsing a
     truncated unicode escape sequence at the end of a string such as
     ‘'\N'’.  It would read one byte beyond the end of the memory
     allocation.

   - bpo-35214(28): The interpreter and extension modules have had
     annotations added so that they work properly under clang’s Memory
     Sanitizer.  A new configure flag –with-memory-sanitizer has been
     added to make test builds of this nature easier to perform.

   - bpo-35193(29): Fix an off by one error in the bytecode peephole
     optimizer where it could read bytes beyond the end of bounds of an
     array when removing unreachable code.  This bug was present in
     every release of Python 3.6 and 3.7 until now.

   - bpo-35169(30): Improved error messages for forbidden assignments.

   - bpo-34022(31): Fix handling of hash-based bytecode files in *note
     zipimport: 138.  Patch by Elvis Pranskevichus.

   - bpo-28401(32): Debug builds will no longer to attempt to import
     extension modules built for the ABI as they were never compatible
     to begin with.  Patch by Stefano Rivera.

   - bpo-29341(33): Clarify in the docstrings of *note os: a5. methods
     that path-like objects are also accepted as input parameters.

   - bpo-35050(34): *note socket: d1.: Fix off-by-one bug in length
     check for ‘AF_ALG’ name and type.

   - bpo-29743(35): Raise *note ValueError: 2ec. instead of *note
     OverflowError: a83. in case of a negative ‘_length_’ in a *note
     ctypes.Array: 1df4. subclass.  Also raise *note TypeError: 198.
     instead of *note AttributeError: 5f0. for non-integer ‘_length_’.
     Original patch by Oren Milman.

   - bpo-16806(36): Fix ‘lineno’ and ‘col_offset’ for multi-line string
     tokens.

   - bpo-35029(37): *note SyntaxWarning: 1ae. raised as an exception at
     code generation time will be now replaced with a *note SyntaxError:
     18e. for better error reporting.

   - bpo-34983(38): Expose *note symtable.Symbol.is_nonlocal(): 1df5. in
     the symtable module.  Patch by Pablo Galindo.

   - bpo-34974(39): *note bytes: 192. and *note bytearray: 344.
     constructors no longer convert unexpected exceptions (e.g.  *note
     MemoryError: 1786. and *note KeyboardInterrupt: bc7.) to *note
     TypeError: 198.

   - bpo-34939(40): Allow annotated names in module namespace that are
     declared global before the annotation happens.  Patch by Pablo
     Galindo.

   - bpo-34973(41): Fixed crash in *note bytes(): 192. when the *note
     list: 24d. argument is mutated while it is iterated.

   - bpo-34876(42): The 'lineno' and 'col_offset' attributes of the AST
     for decorated function and class refer now to the position of the
     corresponding ‘def’, ‘async def’ and ‘class’ instead of the
     position of the first decorator.  This leads to more correct line
     reporting in tracing.  This is the only case when the position of
     child AST nodes can precede the position of the parent AST node.

   - bpo-34879(43): Fix a possible null pointer dereference in
     bytesobject.c.  Patch by Zackery Spytz.

   - bpo-34784(44): Fix the implementation of PyStructSequence_NewType
     in order to create heap allocated StructSequences.

   - bpo-32912(45): A *note SyntaxWarning: 1ae. is now emitted instead
     of a *note DeprecationWarning: 1a3. for invalid escape sequences in
     string and bytes literals.

   - bpo-34854(46): Fixed a crash in compiling string annotations
     containing a lambda with a keyword-only argument that doesn’t have
     a default value.

   - bpo-34850(47): The compiler now produces a *note SyntaxWarning:
     1ae. when identity checks (‘is’ and ‘is not’) are used with certain
     types of literals (e.g.  strings, ints).  These can often work by
     accident in CPython, but are not guaranteed by the language spec.
     The warning advises users to use equality tests (‘==’ and ‘!=’)
     instead.

   - bpo-34824(48): Fix a possible null pointer dereference in
     Modules/_ssl.c.  Patch by Zackery Spytz.

   - bpo-30156(49): The C function ‘property_descr_get()’ uses a
     «cached» tuple to optimize function calls.  But this tuple can be
     discovered in debug mode with *note sys.getobjects(): 28e.  Remove
     the optimization, it’s not really worth it and it causes 3
     different crashes last years.

   - bpo-34762(50): Fix contextvars C API to use PyObject* pointer
     types.

   - bpo-34751(51): The hash function for tuples is now based on xxHash
     which gives better collision results on (formerly) pathological
     cases.  Additionally, on 64-bit systems it improves tuple hashes in
     general.  Patch by Jeroen Demeyer with substantial contributions by
     Tim Peters.

   - bpo-34735(52): Fix a memory leak in Modules/timemodule.c.  Patch by
     Zackery Spytz.

   - bpo-34683(53): Fixed a bug where some SyntaxError error pointed to
     locations that were off-by-one.

   - bpo-34651(54): Only allow the main interpreter to fork.  The avoids
     the possibility of affecting the main interpreter, which is
     critical to operation of the runtime.

   - bpo-34653(55): Remove unused function
     PyParser_SimpleParseStringFilename.

   - bpo-32236(56): Warn that line buffering is not supported if *note
     open(): 316. is called with binary mode and ‘buffering=1’.

   - bpo-34641(57): Further restrict the syntax of the left-hand side of
     keyword arguments in function calls.  In particular,
     ‘f((keyword)=arg)’ is now disallowed.

   - bpo-34637(58): Make the 'start' argument to 'sum()' visible as a
     keyword argument.

   - bpo-1621(59): Do not assume signed integer overflow behavior (C
     undefined behavior) when performing set hash table resizing.

   - bpo-34588(60): Fix an off-by-one in the recursive call pruning
     feature of traceback formatting.

   - bpo-34485(61): On Windows, the LC_CTYPE is now set to the user
     preferred locale at startup.  Previously, the LC_CTYPE locale was
     «C» at startup, but changed when calling setlocale(LC_CTYPE, «») or
     setlocale(LC_ALL, «»).

   - bpo-34485(62): Standard streams like sys.stdout now use the
     «surrogateescape» error handler, instead of «strict», on the POSIX
     locale (when the C locale is not coerced and the UTF-8 Mode is
     disabled).

   - bpo-34485(63): Fix the error handler of standard streams like
     sys.stdout: PYTHONIOENCODING=»:» is now ignored instead of setting
     the error handler to «strict».

   - bpo-34485(64): Python now gets the locale encoding with C code to
     initialize the encoding of standard streams like sys.stdout.
     Moreover, the encoding is now initialized to the Python codec name
     to get a normalized encoding name and to ensure that the codec is
     loaded.  The change avoids importing _bootlocale and _locale
     modules at startup by default.

   - bpo-34527(65): On FreeBSD, Py_DecodeLocale() and Py_EncodeLocale()
     now also forces the ASCII encoding if the LC_CTYPE locale is
     «POSIX», not only if the LC_CTYPE locale is «C».

   - bpo-34527(66): The UTF-8 Mode is now also enabled by the «POSIX»
     locale, not only by the «C» locale.

   - bpo-34403(67): On HP-UX with C or POSIX locale,
     sys.getfilesystemencoding() now returns «ascii» instead of «roman8»
     (when the UTF-8 Mode is disabled and the C locale is not coerced).

   - bpo-34523(68): The Python filesystem encoding is now read earlier
     during the Python initialization.

   - bpo-12458(69): Tracebacks show now correct line number for
     subexpressions in multiline expressions.  Tracebacks show now the
     line number of the first line for multiline expressions instead of
     the line number of the last subexpression.

   - bpo-34408(70): Prevent a null pointer dereference and resource
     leakage in ‘PyInterpreterState_New()’.

   - bpo-34400(71): Fix undefined behavior in parsetok.c.  Patch by
     Zackery Spytz.

   - bpo-33073(72): Added as_integer_ratio to ints to make them more
     interoperable with floats.

   - bpo-34377(73): Update valgrind suppression list to use
     ‘_PyObject_Free’/‘_PyObject_Realloc’ instead of
     ‘PyObject_Free’/‘PyObject_Realloc’.

   - bpo-34353(74): Added the «socket» option in the ‘stat.filemode()’
     Python implementation to match the C implementation.

   - bpo-34320(75): Fix ‘dict(od)’ didn’t copy iteration order of
     OrderedDict.

   - bpo-34113(76): Fixed crash on debug builds when opcode stack was
     adjusted with negative numbers.  Patch by Constantin Petrisor.

   - bpo-34100(77): Compiler now merges constants in tuples and
     frozensets recursively.  Code attributes like ‘co_names’ are merged
     too.

   - bpo-34151(78): Performance of list concatenation, repetition and
     slicing operations is slightly improved.  Patch by Sergey Fedoseev.

   - bpo-34170(79): -X dev: it is now possible to override the memory
     allocator using PYTHONMALLOC even if the developer mode is enabled.

   - bpo-33237(80): Improved *note AttributeError: 5f0. message for
     partially initialized module.

   - bpo-34149(81): Fix min and max functions to get default behavior
     when key is None.

   - bpo-34125(82): Profiling of unbound built-in methods now works when
     ‘**kwargs’ is given.

   - bpo-34141(83): Optimized pickling atomic types (None, bool, int,
     float, bytes, str).

   - bpo-34126(84): Fix crashes when profiling certain invalid calls of
     unbound methods.  Patch by Jeroen Demeyer.

   - bpo-24618(85): Fixed reading invalid memory when create the code
     object with too small varnames tuple or too large argument counts.

   - bpo-34068(86): In *note io.IOBase.close(): 507, ensure that the
     *note closed: 1df6. attribute is not set with a live exception.
     Patch by Zackery Spytz and Serhiy Storchaka.

   - bpo-34087(87): Fix buffer overflow while converting unicode to
     numeric values.

   - bpo-34080(88): Fixed a memory leak in the compiler when it raised
     some uncommon errors during tokenizing.

   - bpo-34066(89): Disabled interruption by Ctrl-C between calling
     ‘open()’ and entering a 'with' block in ‘with open()’.

   - bpo-34042(90): Fix dict.copy() to maintain correct total refcount
     (as reported by sys.gettotalrefcount()).

   - bpo-33418(91): Fix potential memory leak in function object when it
     creates reference cycle.

   - bpo-33985(92): Implement contextvars.ContextVar.name attribute.

   - bpo-33956(93): Update vendored Expat library copy to version 2.2.5.

   - bpo-24596(94): Decref the module object in *note
     PyRun_SimpleFileExFlags(): 1cb2. before calling *note
     PyErr_Print(): 1d14.  Patch by Zackery Spytz.

   - bpo-33451(95): Close directly executed pyc files before calling
     ‘PyEval_EvalCode()’.

   - bpo-1617161(96): The hash of ‘BuiltinMethodType’ instances (methods
     of built-in classes) now depends on the hash of the identity of
     '__self__' instead of its value.  The hash and equality of
     ‘ModuleType’ and ‘MethodWrapperType’ instances (methods of
     user-defined classes and some methods of built-in classes like
     ‘str.__add__’) now depend on the hash and equality of the identity
     of '__self__' instead of its value.  ‘MethodWrapperType’ instances
     no longer support ordering.

   - bpo-33824(97): Fix «LC_ALL=C python3.7 -V»: reset properly the
     command line parser when the encoding changes after reading the
     Python configuration.

   - bpo-33803(98): Fix a crash in hamt.c caused by enabling GC tracking
     for an object that hadn’t all of its fields set to NULL.

   - bpo-33738(99): Seven macro incompatibilities with the Limited API
     were fixed, and the macros *note PyIter_Check(): 1c9a, *note
     PyIndex_Check(): b83. and *note PyExceptionClass_Name(): c5d. were
     added as functions.  A script for automatic macro checks was added.

   - bpo-33786(100): Fix asynchronous generators to handle GeneratorExit
     in athrow() correctly

   - bpo-30167(101): ‘PyRun_SimpleFileExFlags’ removes ‘__cached__’ from
     module in addition to ‘__file__’.

   - bpo-33706(102): Fix a crash in Python initialization when parsing
     the command line options.  Thanks Christoph Gohlke for the bug
     report and the fix!

   - bpo-33597(103): Reduce ‘PyGC_Head’ size from 3 words to 2 words.

   - bpo-30654(104): Fixed reset of the SIGINT handler to SIG_DFL on
     interpreter shutdown even when there was a custom handler set
     previously.  Patch by Philipp Kerling.

   - bpo-33622(105): Fixed a leak when the garbage collector fails to
     add an object with the ‘__del__’ method or referenced by it into
     the *note gc.garbage: 13c9. list.  *note PyGC_Collect(): b87. can
     now be called when an exception is set and preserves it.

   - bpo-33462(106): Make dict and dict views reversible.  Patch by Rémi
     Lapeyre.

   - bpo-23722(107): A *note RuntimeError: 244. is now raised when the
     custom metaclass doesn’t provide the ‘__classcell__’ entry in the
     namespace passed to ‘type.__new__’.  A *note DeprecationWarning:
     1a3. was emitted in Python 3.6–3.7.

   - bpo-33499(108): Add *note PYTHONPYCACHEPREFIX: b9d. environment
     variable and *note -X: 16f. ‘pycache_prefix’ command-line option to
     set an alternate root directory for writing module bytecode cache
     files.

   - bpo-25711(109): The *note zipimport: 138. module has been rewritten
     in pure Python.

   - bpo-33509(110): Fix module_globals parameter of
     warnings.warn_explicit(): don’t crash if module_globals is not a
     dict.

   - bpo-31849(111): Fix signed/unsigned comparison warning in pyhash.c.

   - bpo-33475(112): Fixed miscellaneous bugs in converting annotations
     to strings and optimized parentheses in the string representation.

   - bpo-20104(113): Added support for the ‘setpgroup’, ‘resetids’,
     ‘setsigmask’, ‘setsigdef’ and ‘scheduler’ parameters of
     ‘posix_spawn’.  Patch by Pablo Galindo.

   - bpo-33391(114): Fix a leak in set_symmetric_difference().

   - bpo-33363(115): Raise a SyntaxError for ‘async with’ and ‘async
     for’ statements outside of async functions.

   - bpo-28055(116): Fix unaligned accesses in siphash24().  Patch by
     Rolf Eike Beer.

   - bpo-33128(117): Fix a bug that causes PathFinder to appear twice on
     sys.meta_path.  Patch by Pablo Galindo Salgado.

   - bpo-33331(118): Modules imported last are now cleared first at
     interpreter shutdown.

   - bpo-33312(119): Fixed clang ubsan (undefined behavior sanitizer)
     warnings in dictobject.c by adjusting how the internal struct
     _dictkeysobject shared keys structure is declared.

   - bpo-33305(120): Improved syntax error messages for invalid
     numerical literals.

   - bpo-33306(121): Improved syntax error messages for unbalanced
     parentheses.

   - bpo-33234(122): The list constructor will pre-size and not
     over-allocate when the input length is known.

   - bpo-33270(123): Intern the names for all anonymous code objects.
     Patch by Zackery Spytz.

   - bpo-30455(124): The C and Python code and the documentation related
     to tokens are now generated from a single source file
     ‘Grammar/Tokens’.

   - bpo-33176(125): Add a ‘toreadonly()’ method to memoryviews.

   - bpo-33231(126): Fix potential memory leak in ‘normalizestring()’.

   - bpo-33205(127): Change dict growth function from
     ‘round_up_to_power_2(used*2+hashtable_size/2)’ to
     ‘round_up_to_power_2(used*3)’.  Previously, dict is shrunk only
     when ‘used == 0’.  Now dict has more chance to be shrunk.

   - bpo-29922(128): Improved error messages in “async with” when
     ‘__aenter__()’ or ‘__aexit__()’ return non-awaitable object.

   - bpo-33199(129): Fix ‘ma_version_tag’ in dict implementation is
     uninitialized when copying from key-sharing dict.

   - bpo-33053(130): When using the -m switch, sys.path[0] is now
     explicitly expanded as the 'starting' working directory, rather
     than being left as the empty path (which allows imports from the
     current working directory at the time of the import)

   - bpo-33138(131): Changed standard error message for non-pickleable
     and non-copyable types.  It now says «cannot pickle» instead of
     «can’t pickle» or «cannot serialize».

   - bpo-33018(132): Improve consistency of errors raised by
     ‘issubclass()’ when called with a non-class and an abstract base
     class as the first and second arguments, respectively.  Patch by
     Josh Bronson.

   - bpo-33083(133): ‘math.factorial’ no longer accepts arguments that
     are not int-like.  Patch by Pablo Galindo.

   - bpo-33041(134): Added new opcode *note END_ASYNC_FOR: ca2. and
     fixes the following issues:

        * Setting global *note StopAsyncIteration: 1df7. no longer
          breaks ‘async for’ loops.

        * Jumping into an ‘async for’ loop is now disabled.

        * Jumping out of an ‘async for’ loop no longer corrupts the
          stack.

   - bpo-25750(135): Fix rare Python crash due to bad refcounting in
     ‘type_getattro()’ if a descriptor deletes itself from the class.
     Patch by Jeroen Demeyer.

   - bpo-33041(136): Fixed bytecode generation for «async for» with a
     complex target.  A StopAsyncIteration raised on assigning or
     unpacking will be now propagated instead of stopping the iteration.

   - bpo-33026(137): Fixed jumping out of «with» block by setting
     f_lineno.

   - bpo-33005(138): Fix a crash on fork when using a custom memory
     allocator (ex: using PYTHONMALLOC env var).  _PyGILState_Reinit()
     and _PyInterpreterState_Enable() now use the default RAW memory
     allocator to allocate a new interpreters mutex on fork.

   - bpo-32911(139): Due to unexpected compatibility issues discovered
     during downstream beta testing, reverted bpo-29463(140).
     ‘docstring’ field is removed from Module, ClassDef, FunctionDef,
     and AsyncFunctionDef ast nodes which was added in 3.7a1.  Docstring
     expression is restored as a first statement in their body.  Based
     on patch by Inada Naoki.

   - bpo-17288(141): Prevent jumps from “return” and “exception” trace
     events.

   - bpo-32946(142): Importing names from already imported module with
     «from … import …» is now 30% faster if the module is not a package.

   - bpo-32932(143): Make error message more revealing when there are
     non-str objects in ‘__all__’.

   - bpo-32925(144): Optimized iterating and containing test for literal
     lists consisting of non-constants: ‘x in [a, b]’ and ‘for x in [a,
     b]’.  The case of all constant elements already was optimized.

   - bpo-32889(145): Update Valgrind suppression list to account for the
     rename of ‘Py_ADDRESS_IN_RANG’ to ‘address_in_range’.

   - bpo-32836(146): Don’t use temporary variables in cases of
     list/dict/set comprehensions

   - bpo-31356(147): Remove the new API added in bpo-31356(148)
     (gc.ensure_disabled() context manager).

   - bpo-32305(149): For namespace packages, ensure that both ‘__file__’
     and ‘__spec__.origin’ are set to None.

   - bpo-32303(150): Make sure ‘__spec__.loader’ matches ‘__loader__’
     for namespace packages.

   - bpo-32711(151): Fix the warning messages for Python/ast_unparse.c.
     Patch by Stéphane Wirtel

   - bpo-32583(152): Fix possible crashing in builtin Unicode decoders
     caused by write out-of-bound errors when using customized decode
     error handlers.

   - bpo-32489(153): A *note continue: 180. statement is now allowed in
     the *note finally: 1b0. clause.

   - bpo-17611(154): Simplified the interpreter loop by moving the logic
     of unrolling the stack of blocks into the compiler.  The compiler
     emits now explicit instructions for adjusting the stack of values
     and calling the cleaning up code for *note break: 17f, *note
     continue: 180. and *note return: 1af.

     Removed opcodes ‘BREAK_LOOP’, ‘CONTINUE_LOOP’, ‘SETUP_LOOP’ and
     ‘SETUP_EXCEPT’.  Added new opcodes ‘ROT_FOUR’, ‘BEGIN_FINALLY’ and
     ‘CALL_FINALLY’ and ‘POP_FINALLY’.  Changed the behavior of
     ‘END_FINALLY’ and ‘WITH_CLEANUP_START’.

   - bpo-32285(155): New function unicodedata.is_normalized, which can
     check whether a string is in a specific normal form.

   - bpo-10544(156): Yield expressions are now disallowed in
     comprehensions and generator expressions except the expression for
     the outermost iterable.

   - bpo-32117(157): Iterable unpacking is now allowed without
     parentheses in yield and return statements, e.g.  ‘yield 1, 2, 3,
     *rest’.  Thanks to David Cuthbert for the change and Jordan Chapman
     for added tests.

   - bpo-31902(158): Fix the ‘col_offset’ attribute for ast nodes
     ‘ast.AsyncFor’, ‘ast.AsyncFunctionDef’, and ‘ast.AsyncWith’.
     Previously, ‘col_offset’ pointed to the keyword after ‘async’.

   - bpo-25862(159): Fix assertion failures in the ‘tell()’ method of
     ‘io.TextIOWrapper’.  Patch by Zackery Spytz.

   - bpo-21983(160): Fix a crash in ‘ctypes.cast()’ in case the type
     argument is a ctypes structured data type.  Patch by Eryk Sun and
     Oren Milman.

   - bpo-31577(161): Fix a crash in ‘os.utime()’ in case of a bad ns
     argument.  Patch by Oren Milman.

   - bpo-29832(162): Remove references to “getsockaddrarg” from various
     socket error messages.  Patch by Oren Milman.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35877

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35814

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35766

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35713

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33416

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35720

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35634

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35623

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35214

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35560

   (11) https://bugs.python.org/issue?@action=redirect&bpo=35552

   (12) https://bugs.python.org/issue?@action=redirect&bpo=35504

   (13) https://bugs.python.org/issue?@action=redirect&bpo=35504

   (14) https://bugs.python.org/issue?@action=redirect&bpo=35494

   (15) https://bugs.python.org/issue?@action=redirect&bpo=35444

   (16) https://bugs.python.org/issue?@action=redirect&bpo=35436

   (17) https://bugs.python.org/issue?@action=redirect&bpo=35423

   (18) https://bugs.python.org/issue?@action=redirect&bpo=35357

   (19) https://bugs.python.org/issue?@action=redirect&bpo=35372

   (20) https://bugs.python.org/issue?@action=redirect&bpo=35336

   (21) https://bugs.python.org/issue?@action=redirect&bpo=31241

   (22) https://bugs.python.org/issue?@action=redirect&bpo=33954

   (23) https://bugs.python.org/issue?@action=redirect&bpo=35269

   (24) https://bugs.python.org/issue?@action=redirect&bpo=35224

   (25) https://peps.python.org/pep-0572/

   (26) https://bugs.python.org/issue?@action=redirect&bpo=32492

   (27) https://bugs.python.org/issue?@action=redirect&bpo=35214

   (28) https://bugs.python.org/issue?@action=redirect&bpo=35214

   (29) https://bugs.python.org/issue?@action=redirect&bpo=35193

   (30) https://bugs.python.org/issue?@action=redirect&bpo=35169

   (31) https://bugs.python.org/issue?@action=redirect&bpo=34022

   (32) https://bugs.python.org/issue?@action=redirect&bpo=28401

   (33) https://bugs.python.org/issue?@action=redirect&bpo=29341

   (34) https://bugs.python.org/issue?@action=redirect&bpo=35050

   (35) https://bugs.python.org/issue?@action=redirect&bpo=29743

   (36) https://bugs.python.org/issue?@action=redirect&bpo=16806

   (37) https://bugs.python.org/issue?@action=redirect&bpo=35029

   (38) https://bugs.python.org/issue?@action=redirect&bpo=34983

   (39) https://bugs.python.org/issue?@action=redirect&bpo=34974

   (40) https://bugs.python.org/issue?@action=redirect&bpo=34939

   (41) https://bugs.python.org/issue?@action=redirect&bpo=34973

   (42) https://bugs.python.org/issue?@action=redirect&bpo=34876

   (43) https://bugs.python.org/issue?@action=redirect&bpo=34879

   (44) https://bugs.python.org/issue?@action=redirect&bpo=34784

   (45) https://bugs.python.org/issue?@action=redirect&bpo=32912

   (46) https://bugs.python.org/issue?@action=redirect&bpo=34854

   (47) https://bugs.python.org/issue?@action=redirect&bpo=34850

   (48) https://bugs.python.org/issue?@action=redirect&bpo=34824

   (49) https://bugs.python.org/issue?@action=redirect&bpo=30156

   (50) https://bugs.python.org/issue?@action=redirect&bpo=34762

   (51) https://bugs.python.org/issue?@action=redirect&bpo=34751

   (52) https://bugs.python.org/issue?@action=redirect&bpo=34735

   (53) https://bugs.python.org/issue?@action=redirect&bpo=34683

   (54) https://bugs.python.org/issue?@action=redirect&bpo=34651

   (55) https://bugs.python.org/issue?@action=redirect&bpo=34653

   (56) https://bugs.python.org/issue?@action=redirect&bpo=32236

   (57) https://bugs.python.org/issue?@action=redirect&bpo=34641

   (58) https://bugs.python.org/issue?@action=redirect&bpo=34637

   (59) https://bugs.python.org/issue?@action=redirect&bpo=1621

   (60) https://bugs.python.org/issue?@action=redirect&bpo=34588

   (61) https://bugs.python.org/issue?@action=redirect&bpo=34485

   (62) https://bugs.python.org/issue?@action=redirect&bpo=34485

   (63) https://bugs.python.org/issue?@action=redirect&bpo=34485

   (64) https://bugs.python.org/issue?@action=redirect&bpo=34485

   (65) https://bugs.python.org/issue?@action=redirect&bpo=34527

   (66) https://bugs.python.org/issue?@action=redirect&bpo=34527

   (67) https://bugs.python.org/issue?@action=redirect&bpo=34403

   (68) https://bugs.python.org/issue?@action=redirect&bpo=34523

   (69) https://bugs.python.org/issue?@action=redirect&bpo=12458

   (70) https://bugs.python.org/issue?@action=redirect&bpo=34408

   (71) https://bugs.python.org/issue?@action=redirect&bpo=34400

   (72) https://bugs.python.org/issue?@action=redirect&bpo=33073

   (73) https://bugs.python.org/issue?@action=redirect&bpo=34377

   (74) https://bugs.python.org/issue?@action=redirect&bpo=34353

   (75) https://bugs.python.org/issue?@action=redirect&bpo=34320

   (76) https://bugs.python.org/issue?@action=redirect&bpo=34113

   (77) https://bugs.python.org/issue?@action=redirect&bpo=34100

   (78) https://bugs.python.org/issue?@action=redirect&bpo=34151

   (79) https://bugs.python.org/issue?@action=redirect&bpo=34170

   (80) https://bugs.python.org/issue?@action=redirect&bpo=33237

   (81) https://bugs.python.org/issue?@action=redirect&bpo=34149

   (82) https://bugs.python.org/issue?@action=redirect&bpo=34125

   (83) https://bugs.python.org/issue?@action=redirect&bpo=34141

   (84) https://bugs.python.org/issue?@action=redirect&bpo=34126

   (85) https://bugs.python.org/issue?@action=redirect&bpo=24618

   (86) https://bugs.python.org/issue?@action=redirect&bpo=34068

   (87) https://bugs.python.org/issue?@action=redirect&bpo=34087

   (88) https://bugs.python.org/issue?@action=redirect&bpo=34080

   (89) https://bugs.python.org/issue?@action=redirect&bpo=34066

   (90) https://bugs.python.org/issue?@action=redirect&bpo=34042

   (91) https://bugs.python.org/issue?@action=redirect&bpo=33418

   (92) https://bugs.python.org/issue?@action=redirect&bpo=33985

   (93) https://bugs.python.org/issue?@action=redirect&bpo=33956

   (94) https://bugs.python.org/issue?@action=redirect&bpo=24596

   (95) https://bugs.python.org/issue?@action=redirect&bpo=33451

   (96) https://bugs.python.org/issue?@action=redirect&bpo=1617161

   (97) https://bugs.python.org/issue?@action=redirect&bpo=33824

   (98) https://bugs.python.org/issue?@action=redirect&bpo=33803

   (99) https://bugs.python.org/issue?@action=redirect&bpo=33738

   (100) https://bugs.python.org/issue?@action=redirect&bpo=33786

   (101) https://bugs.python.org/issue?@action=redirect&bpo=30167

   (102) https://bugs.python.org/issue?@action=redirect&bpo=33706

   (103) https://bugs.python.org/issue?@action=redirect&bpo=33597

   (104) https://bugs.python.org/issue?@action=redirect&bpo=30654

   (105) https://bugs.python.org/issue?@action=redirect&bpo=33622

   (106) https://bugs.python.org/issue?@action=redirect&bpo=33462

   (107) https://bugs.python.org/issue?@action=redirect&bpo=23722

   (108) https://bugs.python.org/issue?@action=redirect&bpo=33499

   (109) https://bugs.python.org/issue?@action=redirect&bpo=25711

   (110) https://bugs.python.org/issue?@action=redirect&bpo=33509

   (111) https://bugs.python.org/issue?@action=redirect&bpo=31849

   (112) https://bugs.python.org/issue?@action=redirect&bpo=33475

   (113) https://bugs.python.org/issue?@action=redirect&bpo=20104

   (114) https://bugs.python.org/issue?@action=redirect&bpo=33391

   (115) https://bugs.python.org/issue?@action=redirect&bpo=33363

   (116) https://bugs.python.org/issue?@action=redirect&bpo=28055

   (117) https://bugs.python.org/issue?@action=redirect&bpo=33128

   (118) https://bugs.python.org/issue?@action=redirect&bpo=33331

   (119) https://bugs.python.org/issue?@action=redirect&bpo=33312

   (120) https://bugs.python.org/issue?@action=redirect&bpo=33305

   (121) https://bugs.python.org/issue?@action=redirect&bpo=33306

   (122) https://bugs.python.org/issue?@action=redirect&bpo=33234

   (123) https://bugs.python.org/issue?@action=redirect&bpo=33270

   (124) https://bugs.python.org/issue?@action=redirect&bpo=30455

   (125) https://bugs.python.org/issue?@action=redirect&bpo=33176

   (126) https://bugs.python.org/issue?@action=redirect&bpo=33231

   (127) https://bugs.python.org/issue?@action=redirect&bpo=33205

   (128) https://bugs.python.org/issue?@action=redirect&bpo=29922

   (129) https://bugs.python.org/issue?@action=redirect&bpo=33199

   (130) https://bugs.python.org/issue?@action=redirect&bpo=33053

   (131) https://bugs.python.org/issue?@action=redirect&bpo=33138

   (132) https://bugs.python.org/issue?@action=redirect&bpo=33018

   (133) https://bugs.python.org/issue?@action=redirect&bpo=33083

   (134) https://bugs.python.org/issue?@action=redirect&bpo=33041

   (135) https://bugs.python.org/issue?@action=redirect&bpo=25750

   (136) https://bugs.python.org/issue?@action=redirect&bpo=33041

   (137) https://bugs.python.org/issue?@action=redirect&bpo=33026

   (138) https://bugs.python.org/issue?@action=redirect&bpo=33005

   (139) https://bugs.python.org/issue?@action=redirect&bpo=32911

   (140) https://bugs.python.org/issue?@action=redirect&bpo=29463

   (141) https://bugs.python.org/issue?@action=redirect&bpo=17288

   (142) https://bugs.python.org/issue?@action=redirect&bpo=32946

   (143) https://bugs.python.org/issue?@action=redirect&bpo=32932

   (144) https://bugs.python.org/issue?@action=redirect&bpo=32925

   (145) https://bugs.python.org/issue?@action=redirect&bpo=32889

   (146) https://bugs.python.org/issue?@action=redirect&bpo=32836

   (147) https://bugs.python.org/issue?@action=redirect&bpo=31356

   (148) https://bugs.python.org/issue?@action=redirect&bpo=31356

   (149) https://bugs.python.org/issue?@action=redirect&bpo=32305

   (150) https://bugs.python.org/issue?@action=redirect&bpo=32303

   (151) https://bugs.python.org/issue?@action=redirect&bpo=32711

   (152) https://bugs.python.org/issue?@action=redirect&bpo=32583

   (153) https://bugs.python.org/issue?@action=redirect&bpo=32489

   (154) https://bugs.python.org/issue?@action=redirect&bpo=17611

   (155) https://bugs.python.org/issue?@action=redirect&bpo=32285

   (156) https://bugs.python.org/issue?@action=redirect&bpo=10544

   (157) https://bugs.python.org/issue?@action=redirect&bpo=32117

   (158) https://bugs.python.org/issue?@action=redirect&bpo=31902

   (159) https://bugs.python.org/issue?@action=redirect&bpo=25862

   (160) https://bugs.python.org/issue?@action=redirect&bpo=21983

   (161) https://bugs.python.org/issue?@action=redirect&bpo=31577

   (162) https://bugs.python.org/issue?@action=redirect&bpo=29832


File: python.info,  Node: Library<161>,  Next: Documentation<55>,  Prev: Core and Builtins<158>,  Up: Python 3 8 0 alpha 1

1.24.61.3 Library
.................

   - bpo-35845(1): Add “order” parameter to memoryview.tobytes().

   - bpo-35864(2): The _asdict() method for collections.namedtuple now
     returns a regular dict instead of an OrderedDict.

   - bpo-35537(3): An ExitStack is now used internally within
     subprocess.Popen to clean up pipe file handles.  No behavior change
     in normal operation.  But if closing one handle were ever to cause
     an exception, the others will now be closed instead of leaked.
     (patch by Giampaolo Rodola)

   - bpo-35847(4): RISC-V needed the CTYPES_PASS_BY_REF_HACK. Fixes
     ctypes Structure test_pass_by_value.

   - bpo-35813(5): Shared memory submodule added to multiprocessing to
     avoid need for serialization between processes

   - bpo-35780(6): Fix lru_cache() errors arising in recursive,
     reentrant, or multi-threaded code.  These errors could result in
     orphan links and in the cache being trapped in a state with fewer
     than the specified maximum number of links.  Fix handling of
     negative maxsize which should have been treated as zero.  Fix
     errors in toggling the «full» status flag.  Fix misordering of
     links when errors are encountered.  Sync-up the C code and pure
     Python code for the space saving path in functions with a single
     positional argument.  In this common case, the space overhead of an
     lru cache entry is reduced by almost half.  Fix counting of cache
     misses.  In error cases, the miss count was out of sync with the
     actual number of times the underlying user function was called.

   - bpo-35537(7): *note os.posix_spawn(): 52f. and *note
     os.posix_spawnp(): 1df9. now have a 'setsid' parameter.

   - bpo-23846(8): *note asyncio.ProactorEventLoop: 81e. now catches and
     logs send errors when the self-pipe is full.

   - bpo-34323(9): *note asyncio: b.: Enhance ‘IocpProactor.close()’
     log: wait 1 second before the first log, then log every second.
     Log also the number of seconds since ‘close()’ was called.

   - bpo-35674(10): Add a new *note os.posix_spawnp(): 1df9. function.
     Patch by Joannah Nanjekye.

   - bpo-35733(11): ‘ast.Constant(boolean)’ no longer an instance of
     ‘ast.Num’.  Patch by Anthony Sottile.

   - bpo-35726(12): QueueHandler.prepare() now makes a copy of the
     record before modifying and enqueueing it, to avoid affecting other
     handlers in the chain.

   - bpo-35719(13): Sped up multi-argument *note math: 92. functions
     atan2(), copysign(), remainder() and hypot() by 1.3–2.5 times.

   - bpo-35717(14): Fix KeyError exception raised when using enums and
     compile.  Patch contributed by Rémi Lapeyre.

   - bpo-35699(15): Fixed detection of Visual Studio Build Tools 2017 in
     distutils

   - bpo-32710(16): Fix memory leaks in asyncio ProactorEventLoop on
     overlapped operation failure.

   - bpo-35702(17): The *note time.CLOCK_UPTIME_RAW: c39. constant is
     now available for macOS 10.12.

   - bpo-32710(18): Fix a memory leak in asyncio in the
     ProactorEventLoop when ‘ReadFile()’ or ‘WSASend()’ overlapped
     operation fail immediately: release the internal buffer.

   - bpo-35682(19): Fix ‘asyncio.ProactorEventLoop.sendfile()’: don’t
     attempt to set the result of an internal future if it’s already
     done.

   - bpo-35283(20): Add a deprecated warning for the
     ‘threading.Thread.isAlive()’ method.  Patch by Donghee Na.

   - bpo-35664(21): Improve operator.itemgetter() performance by 33%
     with optimized argument handling and with adding a fast path for
     the common case of a single non-negative integer index into a tuple
     (which is the typical use case in the standard library).

   - bpo-35643(22): Fixed a SyntaxWarning: invalid escape sequence in
     Modules/_sha3/cleanup.py.  Patch by Mickaël Schoentgen.

   - bpo-35619(23): Improved support of custom data descriptors in *note
     help(): ad6. and *note pydoc: ba.

   - bpo-28503(24): The ‘crypt’ module now internally uses the
     ‘crypt_r()’ library function instead of ‘crypt()’ when available.

   - bpo-35614(25): Fixed help() on metaclasses.  Patch by Sanyam
     Khurana.

   - bpo-35568(26): Expose ‘raise(signum)’ as ‘raise_signal’

   - bpo-35588(27): The floor division and modulo operations and the
     *note divmod(): b9b. function on *note fractions.Fraction: 213.
     types are 2–4x faster.  Patch by Stefan Behnel.

   - bpo-35585(28): Speed-up building enums by value, e.g.
     http.HTTPStatus(200).

   - bpo-30561(29): random.gammavariate(1.0, beta) now computes the same
     result as random.expovariate(1.0 / beta).  This synchronizes the
     two algorithms and eliminates some idiosyncrasies in the old
     implementation.  It does however produce a difference stream of
     random variables than it used to.

   - bpo-35537(30): The *note subprocess: dc. module can now use the
     *note os.posix_spawn(): 52f. function in some cases for better
     performance.

   - bpo-35526(31): Delaying the “joke” of barry_as_FLUFL.mandatory to
     Python version 4.0

   - bpo-35523(32): Remove *note ctypes: 2e. callback workaround: no
     longer create a callback at startup.  Avoid SELinux alert on
     ‘import ctypes’ and ‘import uuid’.

   - bpo-31784(33): *note uuid.uuid1(): da3. now calls *note
     time.time_ns(): ce2. rather than ‘int(time.time() * 1e9)’.

   - bpo-35513(34): ‘TextTestRunner’ of ‘unittest.runner’ now uses *note
     time.perf_counter(): c7c. rather than *note time.time(): 55d. to
     measure the execution time of a test: *note time.time(): 55d. can
     go backwards, whereas *note time.perf_counter(): c7c. is monotonic.

   - bpo-35502(35): Fixed reference leaks in *note
     xml.etree.ElementTree.TreeBuilder: c4c. in case of unfinished
     building of the tree (in particular when an error was raised during
     parsing XML).

   - bpo-35348(36): Make *note platform.architecture(): 19ee. parsing of
     ‘file’ command output more reliable: add the ‘-b’ option to the
     ‘file’ command to omit the filename, force the usage of the C
     locale, and search also the «shared object» pattern.

   - bpo-35491(37): *note multiprocessing: 98.: Add ‘Pool.__repr__()’
     and enhance ‘BaseProcess.__repr__()’ (add pid and parent pid) to
     ease debugging.  Pool state constant values are now strings instead
     of integers, for example ‘RUN’ value becomes ‘'RUN'’ instead of
     ‘0’.

   - bpo-35477(38): ‘multiprocessing.Pool.__enter__()’ now fails if the
     pool is not running: ‘with pool:’ fails if used more than once.

   - bpo-31446(39): Copy command line that was passed to CreateProcessW
     since this function can change the content of the input buffer.

   - bpo-35471(40): Python 2.4 dropped MacOS 9 support.  The macpath
     module was deprecated in Python 3.7.  The module is now removed.

   - bpo-23057(41): Unblock Proactor event loop when keyboard interrupt
     is received on Windows

   - bpo-35052(42): Fix xml.dom.minidom cloneNode() on a document with
     an entity: pass the correct arguments to the user data handler of
     an entity.

   - bpo-20239(43): Allow repeated assignment deletion of *note
     unittest.mock.Mock: c41. attributes.  Patch by Pablo Galindo.

   - bpo-17185(44): Set ‘__signature__’ on mock for *note inspect: 82.
     to get signature.  Patch by Karthikeyan Singaravelan.

   - bpo-35445(45): Memory errors during creating posix.environ no
     longer ignored.

   - bpo-35415(46): Validate fileno= argument to socket.socket().

   - bpo-35424(47): ‘multiprocessing.Pool’ destructor now emits *note
     ResourceWarning: 54d. if the pool is still running.

   - bpo-35330(48): When a ‘Mock’ instance was used to wrap an object,
     if ‘side_effect’ is used in one of the mocks of it methods, don’t
     call the original implementation and return the result of using the
     side effect the same way that it is done with return_value.

   - bpo-35346(49): Drop Mac OS 9 and Rhapsody support from the *note
     platform: af. module.  Rhapsody last release was in 2000.  Mac OS 9
     last release was in 2001.

   - bpo-10496(50): ‘check_environ()’ of ‘distutils.utils’ now catches
     *note KeyError: 5e7. on calling *note pwd.getpwuid(): 1dfa.: don’t
     create the ‘HOME’ environment variable in this case.

   - bpo-10496(51): ‘posixpath.expanduser()’ now returns the input
     'path' unchanged if the ‘HOME’ environment variable is not set and
     the current user has no home directory (if the current user
     identifier doesn’t exist in the password database).  This change
     fix the *note site: cc. module if the current user doesn’t exist in
     the password database (if the user has no home directory).

   - bpo-35389(52): *note platform.libc_ver(): 17dd. now uses
     ‘os.confstr('CS_GNU_LIBC_VERSION')’ if available and the
     'executable' parameter is not set.

   - bpo-35394(53): Add empty slots to asyncio abstract protocols.

   - bpo-35310(54): Fix a bug in *note select.select(): fa2. where, in
     some cases, the file descriptor sequences were returned unmodified
     after a signal interruption, even though the file descriptors might
     not be ready yet.  *note select.select(): fa2. will now always
     return empty lists if a timeout has occurred.  Patch by Oran
     Avraham.

   - bpo-35380(55): Enable TCP_NODELAY on Windows for proactor asyncio
     event loop.

   - bpo-35341(56): Add generic version of ‘collections.OrderedDict’ to
     the ‘typing’ module.  Patch by Ismo Toijala.

   - bpo-35371(57): Fixed possible crash in ‘os.utime()’ on Windows when
     pass incorrect arguments.

   - bpo-35346(58): *note platform.uname(): 1dfb. now redirects ‘stderr’
     to *note os.devnull: 1dfc. when running external programs like ‘cmd
     /c ver’.

   - bpo-35066(59): Previously, calling the strftime() method on a
     datetime object with a trailing “%” in the format string would
     result in an exception.  However, this only occurred when the
     datetime C module was being used; the python implementation did not
     match this behavior.  Datetime is now PEP-399 compliant, and will
     not throw an exception on a trailing “%”.

   - bpo-35345(60): The function ‘platform.popen’ has been removed, it
     was deprecated since Python 3.3: use *note os.popen(): 31a.
     instead.

   - bpo-35344(61): On macOS, *note platform.platform(): 1aae. now uses
     *note platform.mac_ver(): 1dfd, if it returns a non-empty release
     string, to get the macOS version rather than the darwin version.

   - bpo-35312(62): Make ‘lib2to3.pgen2.parse.ParseError’ round-trip
     pickle-able.  Patch by Anthony Sottile.

   - bpo-35308(63): Fix regression in ‘webbrowser’ where default
     browsers may be preferred over browsers in the ‘BROWSER’
     environment variable.

   - bpo-24746(64): Avoid stripping trailing whitespace in doctest fancy
     diff.  Original patch by R. David Murray & Jairo Trad.  Enhanced by
     Sanyam Khurana.

   - bpo-28604(65): *note locale.localeconv(): dfa. now sets temporarily
     the ‘LC_CTYPE’ locale to the ‘LC_MONETARY’ locale if the two
     locales are different and monetary strings are non-ASCII. This
     temporary change affects other threads.

   - bpo-35277(66): Update ensurepip to install pip 18.1 and setuptools
     40.6.2.

   - bpo-24209(67): Adds IPv6 support when invoking http.server
     directly.

   - bpo-35226(68): Recursively check arguments when testing for
     equality of *note unittest.mock.call: 1d9b. objects and add note
     that tracking of parameters used to create ancestors of mocks in
     ‘mock_calls’ is not possible.

   - bpo-29564(69): The warnings module now suggests to enable
     tracemalloc if the source is specified, the tracemalloc module is
     available, but tracemalloc is not tracing memory allocations.

   - bpo-35189(70): Modify the following fnctl function to retry if
     interrupted by a signal (EINTR): flock, lockf, fnctl

   - bpo-30064(71): Use add_done_callback() in sock_* asyncio API to
     unsubscribe reader/writer early on calcellation.

   - bpo-35186(72): Removed the «built with» comment added when
     ‘setup.py upload’ is used with either ‘bdist_rpm’ or ‘bdist_dumb’.

   - bpo-35152(73): Allow sending more than 2 GB at once on a
     multiprocessing connection on non-Windows systems.

   - bpo-35062(74): Fix incorrect parsing of *note
     io.IncrementalNewlineDecoder: 1a26.’s 'translate' argument.

   - bpo-35065(75): Remove ‘StreamReaderProtocol._untrack_reader’.  The
     call to ‘_untrack_reader’ is currently performed too soon, causing
     the protocol to forget about the reader before ‘connection_lost’
     can run and feed the EOF to the reader.

   - bpo-34160(76): ElementTree and minidom now preserve the attribute
     order specified by the user.

   - bpo-35079(77): Improve difflib.SequenceManager.get_matching_blocks
     doc by adding “non-overlapping” and changing “!=” to “<”.

   - bpo-33710(78): Deprecated ‘l*gettext()’ functions and methods in
     the *note gettext: 67. module.  They return encoded bytes instead
     of Unicode strings and are artifacts from Python 2 times.  Also
     deprecated functions and methods related to setting the charset for
     ‘l*gettext()’ functions and methods.

   - bpo-35017(79): *note socketserver.BaseServer.serve_forever(): 1347.
     now exits immediately if it’s *note shutdown(): 1dfe. method is
     called while it is polling for new events.

   - bpo-35024(80): ‘importlib’ no longer logs ‘wrote <bytecode path>’
     redundantly after ‘(created|could not create) <bytecode path>’ is
     already logged.  Patch by Quentin Agren.

   - bpo-35047(81): ‘unittest.mock’ now includes mock calls in exception
     messages if ‘assert_not_called’, ‘assert_called_once’, or
     ‘assert_called_once_with’ fails.  Patch by Petter Strandmark.

   - bpo-31047(82): Fix ‘ntpath.abspath’ regression where it didn’t
     remove a trailing separator on Windows.  Patch by Tim Graham.

   - bpo-35053(83): tracemalloc now tries to update the traceback when
     an object is reused from a «free list» (optimization for faster
     object creation, used by the builtin list type for example).

   - bpo-31553(84): Add the –json-lines option to json.tool.  Patch by
     hongweipeng.

   - bpo-34794(85): Fixed a leak in Tkinter when pass the Python wrapper
     around Tcl_Obj back to Tcl/Tk.

   - bpo-34909(86): Enum: fix grandchildren subclassing when parent
     mixed with concrete data types.

   - bpo-35022(87): *note unittest.mock.MagicMock: 1091. now supports
     the ‘__fspath__’ method (from *note os.PathLike: e4d.).

   - bpo-35008(88): Fixed references leaks when call the
     ‘__setstate__()’ method of *note xml.etree.ElementTree.Element:
     363. in the C implementation for already initialized element.

   - bpo-23420(89): Verify the value for the parameter “-s” of the
     cProfile CLI. Patch by Robert Kuska

   - bpo-33947(90): dataclasses now handle recursive reprs without
     raising RecursionError.

   - bpo-34890(91): Make *note inspect.iscoroutinefunction(): 30d, *note
     inspect.isgeneratorfunction(): 1b43. and *note
     inspect.isasyncgenfunction(): 1b44. work with *note
     functools.partial(): 217.  Patch by Pablo Galindo.

   - bpo-34521(92): Use *note socket.CMSG_SPACE(): 1dff. to calculate
     ancillary data size instead of *note socket.CMSG_LEN(): 1e00. in
     ‘multiprocessing.reduction.recvfds()’ as RFC 3542(93) requires the
     use of the former for portable applications.

   - bpo-31522(94): The ‘mailbox.mbox.get_string’ function 'from_'
     parameter can now successfully be set to a non-default value.

   - bpo-34970(95): Protect tasks weak set manipulation in
     ‘asyncio.all_tasks()’

   - bpo-34969(96): gzip: Add –fast, –best on the gzip CLI, these
     parameters will be used for the fast compression method (quick) or
     the best method compress (slower, but smaller file).  Also, change
     the default compression level to 6 (tradeoff).

   - bpo-16965(97): The 2to3 ‘execfile’ fixer now opens the file with
     mode ‘'rb'’.  Patch by Zackery Spytz.

   - bpo-34966(98): *note pydoc: ba. now supports aliases not only to
     methods defined in the end class, but also to inherited methods.
     The docstring is not duplicated for aliases.

   - bpo-34926(99): *note mimetypes.MimeTypes.guess_type(): 1e01. now
     accepts *note path-like object: 5a1. in addition to url strings.
     Patch by Mayank Asthana.

   - bpo-23831(100): Add ‘moveto()’ method to the ‘tkinter.Canvas’
     widget.  Patch by Juliette Monsel.

   - bpo-34941(101): Methods ‘find()’, ‘findtext()’ and ‘findall()’ of
     the ‘Element’ class in the *note xml.etree.ElementTree: 12b. module
     are now able to find children which are instances of ‘Element’
     subclasses.

   - bpo-32680(102): *note smtplib.SMTP: b29. objects now always have a
     ‘sock’ attribute present

   - bpo-34769(103): Fix for async generators not finalizing when event
     loop is in debug mode and garbage collector runs in another thread.

   - bpo-34936(104): Fix ‘TclError’ in
     ‘tkinter.Spinbox.selection_element()’.  Patch by Juliette Monsel.

   - bpo-34829(105): Add methods ‘selection_from’, ‘selection_range’,
     ‘selection_present’ and ‘selection_to’ to the ‘tkinter.Spinbox’ for
     consistency with the ‘tkinter.Entry’ widget.  Patch by Juliette
     Monsel.

   - bpo-34911(106): Added 'secure_protocols' argument to
     'http.cookiejar.DefaultCookiePolicy' to allow for tweaking of
     protocols and also to add support by default for 'wss', the secure
     websocket protocol.

   - bpo-34922(107): Fixed integer overflow in the *note digest(): 1e02.
     and *note hexdigest(): 1e03. methods for the SHAKE algorithm in the
     *note hashlib: 6c. module.

   - bpo-34925(108): 25% speedup in argument parsing for the functions
     in the bisect module.

   - bpo-34900(109): Fixed *note unittest.TestCase.debug(): 1c31. when
     used to call test methods with subtests.  Patch by Bruno Oliveira.

   - bpo-34844(110): logging.Formatter enhancement - Ensure styles and
     fmt matches in logging.Formatter - Added validate method in each
     format style class: StrFormatStyle, PercentStyle,
     StringTemplateStyle.  - This method is called in the constructor of
     logging.Formatter class - Also re-raise the KeyError in the format
     method of each style class, so it would a bit clear that it’s an
     error with the invalid format fields.

   - bpo-34897(111): Adjust test.support.missing_compiler_executable
     check so that a nominal command name of «» is ignored.  Patch by
     Michael Felt.

   - bpo-34871(112): Fix inspect module polluted ‘sys.modules’ when
     parsing ‘__text_signature__’ of callable.

   - bpo-34898(113): Add ‘mtime’ argument to ‘gzip.compress’ for
     reproducible output.  Patch by Guo Ci Teo.

   - bpo-28441(114): On Cygwin and MinGW, ensure that ‘sys.executable’
     always includes the full filename in the path, including the ‘.exe’
     suffix (unless it is a symbolic link).

   - bpo-34866(115): Adding ‘max_num_fields’ to ‘cgi.FieldStorage’ to
     make DOS attacks harder by limiting the number of
     ‘MiniFieldStorage’ objects created by ‘FieldStorage’.

   - bpo-34711(116): http.server ensures it reports HTTPStatus.NOT_FOUND
     when the local path ends with «/» and is not a directory, even if
     the underlying OS (e.g.  AIX) accepts such paths as a valid file
     reference.  Patch by Michael Felt.

   - bpo-34872(117): Fix self-cancellation in C implementation of
     asyncio.Task

   - bpo-34849(118): Don’t log waiting for ‘selector.select’ in asyncio
     loop iteration.  The waiting is pretty normal for any asyncio
     program, logging its time just adds a noise to logs without any
     useful information provided.

   - bpo-34022(119): The ‘SOURCE_DATE_EPOCH’ environment variable no
     longer overrides the value of the 'invalidation_mode' argument to
     *note py_compile.compile(): c1c, and determines its default value
     instead.

   - bpo-34819(120): Use a monotonic clock to compute timeouts in
     ‘Executor.map()’ and ‘as_completed()’, in order to prevent timeouts
     from deviating when the system clock is adjusted.

   - bpo-34758(121): Add .wasm -> application/wasm to list of recognized
     file types and content type headers

   - bpo-34789(122): *note xml.sax.make_parser(): 1e04. now accepts any
     iterable as its 'parser_list' argument.  Patch by Andrés Delfino.

   - bpo-34334(123): In ‘QueueHandler’, clear ‘exc_text’ from
     ‘LogRecord’ to prevent traceback from being written twice.

   - bpo-34687(124): On Windows, asyncio now uses ProactorEventLoop,
     instead of SelectorEventLoop, by default.

   - bpo-5950(125): Support reading zip files with archive comments in
     *note zipimport: 138.

   - bpo-32892(126): The parser now represents all constants as *note
     ast.Constant: 2ef. instead of using specific constant AST types
     (‘Num’, ‘Str’, ‘Bytes’, ‘NameConstant’ and ‘Ellipsis’).  These
     classes are considered deprecated and will be removed in future
     Python versions.

   - bpo-34728(127): Add deprecation warning when ‘loop’ is used in
     methods: ‘asyncio.sleep’, ‘asyncio.wait’ and ‘asyncio.wait_for’.

   - bpo-34738(128): ZIP files created by ‘distutils’ will now include
     entries for directories.

   - bpo-34659(129): Add an optional 'initial' argument to
     itertools.accumulate().

   - bpo-29577(130): Support multiple mixin classes when creating Enums.

   - bpo-34670(131): Add SSLContext.post_handshake_auth and
     SSLSocket.verify_client_post_handshake for TLS 1.3’s post handshake
     authentication feature.

   - bpo-32718(132): The Activate.ps1 script from venv works with
     PowerShell Core 6.1 and is now available under all operating
     systems.

   - bpo-31177(133): Fix bug that prevented using *note reset_mock: ef8.
     on mock instances with deleted attributes

   - bpo-34672(134): Add a workaround, so the ‘'Z'’ *note
     time.strftime(): 13f1. specifier on the musl C library can work in
     some cases.

   - bpo-34666(135): Implement ‘asyncio.StreamWriter.awrite’ and
     ‘asyncio.StreamWriter.aclose()’ coroutines.  Methods are needed for
     providing a consistent stream API with control flow switched on by
     default.

   - bpo-6721(136): Acquire the logging module’s commonly used internal
     locks while fork()ing to avoid deadlocks in the child process.

   - bpo-34658(137): Fix a rare interpreter unhandled exception state
     SystemError only seen when using subprocess with a preexec_fn while
     an after_parent handler has been registered with
     os.register_at_fork and the fork system call fails.

   - bpo-34652(138): Ensure *note os.lchmod(): 529. is never defined on
     Linux.

   - bpo-34638(139): Store a weak reference to stream reader to break
     strong references loop between reader and protocol.  It allows to
     detect and close the socket if the stream is deleted (garbage
     collected) without ‘close()’ call.

   - bpo-34536(140): ‘Enum._missing_’: raise ‘ValueError’ if None
     returned and ‘TypeError’ if non-member is returned.

   - bpo-34636(141): Speed up re scanning of many non-matching
     characters for s w and d within bytes objects.  (microoptimization)

   - bpo-24412(142): Add *note addModuleCleanup(): c42. and *note
     addClassCleanup(): c43. to unittest to support cleanups for *note
     setUpModule(): c44. and *note setUpClass(): c45.  Patch by Lisa
     Roach.

   - bpo-34630(143): Don’t log SSL certificate errors in asyncio code
     (connection error logging is skipped already).

   - bpo-32490(144): Prevent filename duplication in *note subprocess:
     dc. exception messages.  Patch by Zackery Spytz.

   - bpo-34363(145): dataclasses.asdict() and .astuple() now handle
     namedtuples correctly.

   - bpo-34625(146): Update vendorized expat library version to 2.2.6.

   - bpo-32270(147): The subprocess module no longer mistakenly closes
     redirected fds even when they were in pass_fds when outside of the
     default {0, 1, 2} set.

   - bpo-34622(148): Create a dedicated ‘asyncio.CancelledError’,
     ‘asyncio.InvalidStateError’ and ‘asyncio.TimeoutError’ exception
     classes.  Inherit them from corresponding exceptions from
     ‘concurrent.futures’ package.  Extract ‘asyncio’ exceptions into a
     separate file.

   - bpo-34610(149): Fixed iterator of
     ‘multiprocessing.managers.DictProxy’.

   - bpo-34421(150): Fix distutils logging for non-ASCII strings.  This
     caused installation issues on Windows.

   - bpo-34604(151): Fix possible mojibake in the error message of
     ‘pwd.getpwnam’ and ‘grp.getgrnam’ using string representation
     because of invisible characters or trailing whitespaces.  Patch by
     William Grzybowski.

   - bpo-30977(152): Make uuid.UUID use ‘__slots__’ to reduce its memory
     footprint.  Based on original patch by Wouter Bolsterlee.

   - bpo-34574(153): OrderedDict iterators are not exhausted during
     pickling anymore.  Patch by Sergey Fedoseev.

   - bpo-8110(154): Refactored *note subprocess: dc. to check for
     Windows-specific modules rather than ‘sys.platform == 'win32'’.

   - bpo-34530(155): ‘distutils.spawn.find_executable()’ now falls back
     on *note os.defpath: 1dcc. if the ‘PATH’ environment variable is
     not set.

   - bpo-34563(156): On Windows, fix multiprocessing.Connection for very
     large read: fix _winapi.PeekNamedPipe() and _winapi.ReadFile() for
     read larger than INT_MAX (usually ‘2**31-1’).

   - bpo-34558(157): Correct typo in Lib/ctypes/_aix.py

   - bpo-34282(158): Move ‘Enum._convert’ to ‘EnumMeta._convert_’ and
     fix enum members getting shadowed by parent attributes.

   - bpo-22872(159): When the queue is closed, *note ValueError: 2ec. is
     now raised by *note multiprocessing.Queue.put(): 1e05. and *note
     multiprocessing.Queue.get(): 1e06. instead of *note AssertionError:
     8b9. and *note OSError: 2c0, respectively.  Patch by Zackery Spytz.

   - bpo-34515(160): Fix parsing non-ASCII identifiers in
     ‘lib2to3.pgen2.tokenize’ ( PEP 3131(161)).

   - bpo-13312(162): Avoids a possible integer underflow (undefined
     behavior) in the time module’s year handling code when passed a
     very low negative year value.

   - bpo-34472(163): Improved compatibility for streamed files in *note
     zipfile: 137.  Previously an optional signature was not being
     written and certain ZIP applications were not supported.  Patch by
     Silas Sewell.

   - bpo-34454(164): Fix the .fromisoformat() methods of datetime types
     crashing when given unicode with non-UTF-8-encodable code points.
     Specifically, datetime.fromisoformat() now accepts surrogate
     unicode code points used as the separator.  Report and tests by
     Alexey Izbyshev, patch by Paul Ganssle.

   - bpo-6700(165): Fix inspect.getsourcelines for module level
     frames/tracebacks.  Patch by Vladimir Matveev.

   - bpo-34171(166): Running the *note trace: 103. module no longer
     creates the ‘trace.cover’ file.

   - bpo-34441(167): Fix crash when an ‘ABC’-derived class with invalid
     ‘__subclasses__’ is passed as the second argument to *note
     issubclass(): 9c6.  Patch by Alexey Izbyshev.

   - bpo-34427(168): Fix infinite loop in ‘a.extend(a)’ for
     ‘MutableSequence’ subclasses.

   - bpo-34412(169): Make *note signal.strsignal(): 1e07. work on HP-UX.
     Patch by Michael Osipov.

   - bpo-20849(170): shutil.copytree now accepts a new ‘dirs_exist_ok’
     keyword argument.  Patch by Josh Bronson.

   - bpo-31715(171): Associate ‘.mjs’ file extension with
     ‘application/javascript’ MIME Type.

   - bpo-34384(172): *note os.readlink(): b1c. now accepts *note
     path-like: 5a1. and *note bytes: 192. objects on Windows.

   - bpo-22602(173): The UTF-7 decoder now raises *note
     UnicodeDecodeError: c0a. for ill-formed sequences starting with «+»
     (as specified in RFC 2152).  Patch by Zackery Spytz.

   - bpo-2122(174): The *note mmap.flush(): c91. method now returns
     ‘None’ on success, raises an exception on error under all
     platforms.

   - bpo-34341(175): Appending to the ZIP archive with the ZIP64
     extension no longer grows the size of extra fields of existing
     entries.

   - bpo-34333(176): Fix %-formatting in *note
     pathlib.PurePath.with_suffix(): 193e. when formatting an error
     message.

   - bpo-18540(177): The *note imaplib.IMAP4: b01. and *note
     imaplib.IMAP4_SSL: b02. classes now resolve to the local host IP
     correctly when the default value of 'host' parameter (‘''’) is
     used.

   - bpo-26502(178): Implement ‘traceback.FrameSummary.__len__()’ method
     to preserve compatibility with the old tuple API.

   - bpo-34318(179): *note assertRaises(): 751, *note
     assertRaisesRegex(): 753, *note assertWarns(): 136c. and *note
     assertWarnsRegex(): 136d. no longer success if the passed callable
     is None.  They no longer ignore unknown keyword arguments in the
     context manager mode.  A DeprecationWarning was raised in these
     cases since Python 3.5.

   - bpo-9372(180): Deprecate *note __getitem__(): 588. methods of *note
     xml.dom.pulldom.DOMEventStream: 93f, *note
     wsgiref.util.FileWrapper: 940. and *note fileinput.FileInput: 941.

   - bpo-33613(181): Fix a race condition in
     ‘multiprocessing.semaphore_tracker’ when the tracker receives
     SIGINT before it can register signal handlers for ignoring it.

   - bpo-34248(182): Report filename in the exception raised when the
     database file cannot be opened by *note dbm.gnu.open(): 1e08. and
     *note dbm.ndbm.open(): 1e09. due to OS-related error.  Patch by
     Zsolt Cserna.

   - bpo-33089(183): Add math.dist() to compute the Euclidean distance
     between two points.

   - bpo-34246(184): *note smtplib.SMTP.send_message(): 105c. no longer
     modifies the content of the 'mail_options' argument.  Patch by
     Pablo S. Blum de Aguiar.

   - bpo-31047(185): Fix ‘ntpath.abspath’ for invalid paths on windows.
     Patch by Franz Woellert.

   - bpo-32321(186): Add pure Python fallback for functools.reduce.
     Patch by Robert Wright.

   - bpo-34270(187): The default asyncio task class now always has a
     name which can be get or set using two new methods (*note
     get_name(): bd3. and *note set_name(): bd2.) and is visible in the
     *note repr(): 1c1. output.  An initial name can also be set using
     the new ‘name’ keyword argument to *note asyncio.create_task():
     1c9. or the ‘create_task()’ method of the event loop.  If no
     initial name is set, the default Task implementation generates a
     name like ‘Task-1’ using a monotonic counter.

   - bpo-34263(188): asyncio’s event loop will not pass timeouts longer
     than one day to epoll/select etc.

   - bpo-34035(189): Fix several AttributeError in zipfile seek()
     methods.  Patch by Mickaël Schoentgen.

   - bpo-32215(190): Fix performance regression in *note sqlite3: d4.
     when a DML statement appeared in a different line than the rest of
     the SQL query.

   - bpo-34075(191): Deprecate passing non-ThreadPoolExecutor instances
     to ‘AbstractEventLoop.set_default_executor()’.

   - bpo-34251(192): Restore ‘msilib.Win64’ to preserve backwards
     compatibility since it’s already used by ‘distutils’” ‘bdist_msi’
     command.

   - bpo-19891(193): Ignore errors caused by missing / non-writable
     homedir while writing history during exit of an interactive
     session.  Patch by Anthony Sottile.

   - bpo-33089(194): Enhanced math.hypot() to support more than two
     dimensions.

   - bpo-34228(195): tracemalloc: PYTHONTRACEMALLOC=0 environment
     variable and -X tracemalloc=0 command line option are now allowed
     to disable explicitly tracemalloc at startup.

   - bpo-13041(196): Use *note shutil.get_terminal_size(): 130b. to
     calculate the terminal width correctly in the
     ‘argparse.HelpFormatter’ class.  Initial patch by Zbyszek
     Jędrzejewski-Szmek.

   - bpo-34213(197): Allow frozen dataclasses to have a field named
     «object».  Previously this conflicted with an internal use of
     «object».

   - bpo-34052(198): *note sqlite3.Connection.create_aggregate(): 5a8,
     *note sqlite3.Connection.create_function(): 5a7, *note
     sqlite3.Connection.set_authorizer(): 5a9, *note
     sqlite3.Connection.set_progress_handler(): 5aa. methods raises
     TypeError when unhashable objects are passed as callable.  These
     methods now don’t pass such objects to SQLite API. Previous
     behavior could lead to segfaults.  Patch by Sergey Fedoseev.

   - bpo-34197(199): Attributes 'skipinitialspace', 'doublequote' and
     'strict' of the 'dialect' attribute of the *note csv: 2d. reader
     are now *note bool: 3c3. instances instead of integers 0 or 1.

   - bpo-32788(200): Errors other than *note TypeError: 198. raised in
     methods ‘__adapt__()’ and ‘__conform__()’ in the *note sqlite3: d4.
     module are now propagated to the user.

   - bpo-21446(201): The ‘reload’ fixer now uses *note
     importlib.reload(): 73e. instead of deprecated ‘imp.reload()’.

   - bpo-940286(202): pydoc’s ‘Helper.showtopic()’ method now prints the
     cross references of a topic correctly.

   - bpo-34164(203): *note base64.b32decode(): 1227. could raise
     UnboundLocalError or OverflowError for incorrect padding.  Now it
     always raises ‘base64.Error’ in these cases.

   - bpo-33729(204): Fixed issues with arguments parsing in *note
     hashlib: 6c.

   - bpo-34097(205): ZipFile can zip files older than 1980-01-01 and
     newer than 2107-12-31 using a new ‘strict_timestamps’ parameter at
     the cost of setting the timestamp to the limit.

   - bpo-34108(206): Remove extraneous CR in 2to3 refactor.

   - bpo-34070(207): Make sure to only check if the handle is a tty,
     when opening a file with ‘buffering=-1’.

   - bpo-27494(208): Reverted bpo-27494(209).  2to3 rejects now a
     trailing comma in generator expressions.

   - bpo-33967(210): functools.singledispatch now raises TypeError
     instead of IndexError when no positional arguments are passed.

   - bpo-34041(211): Add the parameter 'deterministic' to the *note
     sqlite3.Connection.create_function(): 5a7. method.  Patch by Sergey
     Fedoseev.

   - bpo-34056(212): Ensure the loader shim created by ‘imp.load_module’
     always returns bytes from its ‘get_data()’ function.  This fixes
     using ‘imp.load_module’ with PEP 552(213) hash-based pycs.

   - bpo-34054(214): The multiprocessing module now uses the monotonic
     clock *note time.monotonic(): 55c. instead of the system clock
     *note time.time(): 55d. to implement timeout.

   - bpo-34043(215): Optimize tarfile uncompress performance about 15%
     when gzip is used.

   - bpo-34044(216): ‘subprocess.Popen’ now copies the 'startupinfo'
     argument to leave it unchanged: it will modify the copy, so that
     the same ‘STARTUPINFO’ object can be used multiple times.

   - bpo-34010(217): Fixed a performance regression for reading streams
     with tarfile.  The buffered read should use a list, instead of
     appending to a bytes object.

   - bpo-34019(218): webbrowser: Correct the arguments passed to Opera
     Browser when opening a new URL using the ‘webbrowser’ module.
     Patch by Bumsik Kim.

   - bpo-34003(219): csv.DictReader now creates dicts instead of
     OrderedDicts.  Patch by Michael Selik.

   - bpo-33978(220): Closed existing logging handlers before
     reconfiguration via fileConfig and dictConfig.  Patch by
     Karthikeyan Singaravelan.

   - bpo-14117(221): Make minor tweaks to turtledemo.  The “wikipedia”
     example is now “rosette”, describing what it draws.  The “penrose”
     print output is reduced.  The’1024” output of “tree” is eliminated.

   - bpo-33974(222): Fixed passing lists and tuples of strings
     containing special characters ‘"’, ‘\’, ‘{’, ‘}’ and ‘\n’ as
     options to *note ttk: ff. widgets.

   - bpo-27500(223): Fix getaddrinfo to resolve IPv6 addresses
     correctly.

   - bpo-24567(224): Improve random.choices() to handle subnormal input
     weights that could occasionally trigger an IndexError.

   - bpo-33871(225): Fixed integer overflow in *note os.readv(): d57,
     *note os.writev(): d5a, *note os.preadv(): d56. and *note
     os.pwritev(): d59. and in *note os.sendfile(): d07. with 'headers'
     or 'trailers' arguments (on BSD-based OSes and macOS).

   - bpo-25007(226): Add *note copy.copy(): 758. and *note
     copy.deepcopy(): d67. support to zlib compressors and
     decompressors.  Patch by Zackery Spytz.

   - bpo-33929(227): multiprocessing: Fix a race condition in Popen of
     multiprocessing.popen_spawn_win32.  The child process now
     duplicates the read end of pipe instead of «stealing» it.
     Previously, the read end of pipe was «stolen» by the child process,
     but it leaked a handle if the child process had been terminated
     before it could steal the handle from the parent process.

   - bpo-33899(228): Tokenize module now implicitly emits a NEWLINE when
     provided with input that does not have a trailing new line.  This
     behavior now matches what the C tokenizer does internally.
     Contributed by Ammar Askar.

   - bpo-33897(229): Added a “force” keyword argument to
     logging.basicConfig().

   - bpo-33695(230): *note shutil.copytree(): c20. uses *note
     os.scandir(): c56. function and all copy functions depending from
     it use cached *note os.stat(): 26d. values.  The speedup for
     copying a directory with 8000 files is around +9% on Linux, +20% on
     Windows and + 30% on a Windows SMB share.  Also the number of *note
     os.stat(): 26d. syscalls is reduced by 38% making *note
     shutil.copytree(): c20. especially faster on network filesystems.
     (Contributed by Giampaolo Rodola” in bpo-33695(231).)

   - bpo-33916(232): bz2 and lzma: When Decompressor.__init__() is
     called twice, free the old lock to not leak memory.

   - bpo-32568(233): Make select.epoll() and its documentation
     consistent regarding 'sizehint' and 'flags'.

   - bpo-33833(234): Fixed bug in asyncio where ProactorSocketTransport
     logs AssertionError if force closed during write.

   - bpo-33663(235): Convert content length to string before putting to
     header.

   - bpo-33721(236): *note os.path: a6. functions that return a boolean
     result like *note exists(): c05, *note lexists(): c06, *note
     isdir(): c07, *note isfile(): c08, *note islink(): c03, and *note
     ismount(): c09, and *note pathlib.Path: 266. methods that return a
     boolean result like *note exists(): c0d, *note is_dir(): 53b, *note
     is_file(): 53a, *note is_mount(): c0e, *note is_symlink(): c0f,
     *note is_block_device(): c10, *note is_char_device(): c11, *note
     is_fifo(): c12, *note is_socket(): c13. now return ‘False’ instead
     of raising *note ValueError: 2ec. or its subclasses *note
     UnicodeEncodeError: 888. and *note UnicodeDecodeError: c0a. for
     paths that contain characters or bytes unrepresentable at the OS
     level.

   - bpo-26544(237): Fixed implementation of *note platform.libc_ver():
     17dd.  It almost always returned version “2.9” for glibc.

   - bpo-33843(238): Remove deprecated ‘cgi.escape’, ‘cgi.parse_qs’ and
     ‘cgi.parse_qsl’.

   - bpo-33842(239): Remove ‘tarfile.filemode’ which is deprecated since
     Python 3.3.

   - bpo-30167(240): Prevent site.main() exception if PYTHONSTARTUP is
     set.  Patch by Steve Weber.

   - bpo-33805(241): Improve error message of dataclasses.replace() when
     an InitVar is not specified

   - bpo-33687(242): Fix the call to ‘os.chmod()’ for ‘uu.decode()’ if a
     mode is given or decoded.  Patch by Timo Furrer.

   - bpo-33812(243): Datetime instance d with non-None tzinfo, but with
     d.tzinfo.utcoffset(d) returning None is now treated as naive by the
     astimezone() method.

   - bpo-32108(244): In configparser, don’t clear section when it is
     assigned to itself.

   - bpo-27397(245): Make email module properly handle invalid-length
     base64 strings.

   - bpo-33578(246): Implement multibyte encoder/decoder state methods

   - bpo-30805(247): Avoid race condition with debug logging

   - bpo-33476(248): Fix _header_value_parser.py when address group is
     missing final “;”.  Contributed by Enrique Perez-Terron

   - bpo-33694(249): asyncio: Fix a race condition causing data loss on
     pause_reading()/resume_reading() when using the ProactorEventLoop.

   - bpo-32493(250): Correct test for ‘uuid_enc_be’ availability in
     ‘configure.ac’.  Patch by Michael Felt.

   - bpo-33792(251): Add asyncio.WindowsSelectorEventLoopPolicy and
     asyncio.WindowsProactorEventLoopPolicy.

   - bpo-33274(252): W3C DOM Level 1 specifies return value of
     Element.removeAttributeNode() as «The Attr node that was removed.»
     xml.dom.minidom now complies with this requirement.

   - bpo-33778(253): Update ‘unicodedata’’s database to Unicode version
     11.0.0.

   - bpo-33165(254): Added a stacklevel parameter to logging calls to
     allow use of wrapper/helper functions for logging APIs.

   - bpo-33770(255): improve base64 exception message for encoded inputs
     of invalid length

   - bpo-33769(256): asyncio/start_tls: Fix error message; cancel
     callbacks in case of an unhandled error; mark SSLTransport as
     closed if it is aborted.

   - bpo-33767(257): The concatenation (‘+’) and repetition (‘*’)
     sequence operations now raise *note TypeError: 198. instead of
     *note SystemError: 796. when performed on *note mmap.mmap: 51a.
     objects.  Patch by Zackery Spytz.

   - bpo-33734(258): asyncio/ssl: Fix AttributeError, increase default
     handshake timeout

   - bpo-31014(259): Fixed creating a controller for *note webbrowser:
     11b. when a user specifies a path to an entry in the BROWSER
     environment variable.  Based on patch by John Still.

   - bpo-2504(260): Add gettext.pgettext() and variants.

   - bpo-33197(261): Add description property for _ParameterKind

   - bpo-32751(262): When cancelling the task due to a timeout, *note
     asyncio.wait_for(): 816. will now wait until the cancellation is
     complete.

   - bpo-32684(263): Fix gather to propagate cancellation of itself even
     with return_exceptions.

   - bpo-33654(264): Support protocol type switching in
     SSLTransport.set_protocol().

   - bpo-33674(265): Pause the transport as early as possible to further
     reduce the risk of data_received() being called before
     connection_made().

   - bpo-33671(266): *note shutil.copyfile(): c50, *note shutil.copy():
     c51, *note shutil.copy2(): c52, *note shutil.copytree(): c20. and
     *note shutil.move(): c53. use platform-specific fast-copy syscalls
     on Linux and macOS in order to copy the file more efficiently.  On
     Windows *note shutil.copyfile(): c50. uses a bigger default buffer
     size (1 MiB instead of 16 KiB) and a *note memoryview(): 165.-based
     variant of *note shutil.copyfileobj(): c54. is used.  The speedup
     for copying a 512MiB file is about +26% on Linux, +50% on macOS and
     +40% on Windows.  Also, much less CPU cycles are consumed.
     (Contributed by Giampaolo Rodola” in bpo-25427(267).)

   - bpo-33674(268): Fix a race condition in
     SSLProtocol.connection_made() of asyncio.sslproto: start
     immediately the handshake instead of using call_soon().
     Previously, data_received() could be called before the handshake
     started, causing the handshake to hang or fail.

   - bpo-31647(269): Fixed bug where calling write_eof() on a
     _SelectorSocketTransport after it’s already closed raises
     AttributeError.

   - bpo-32610(270): Make asyncio.all_tasks() return only pending tasks.

   - bpo-32410(271): Avoid blocking on file IO in sendfile fallback code

   - bpo-33469(272): Fix RuntimeError after closing loop that used
     run_in_executor

   - bpo-33672(273): Fix Task.__repr__ crash with Cython’s bogus
     coroutines

   - bpo-33654(274): Fix transport.set_protocol() to support switching
     between asyncio.Protocol and asyncio.BufferedProtocol.  Fix
     loop.start_tls() to work with asyncio.BufferedProtocols.

   - bpo-33652(275): Pickles of type variables and subscripted generics
     are now future-proof and compatible with older Python versions.

   - bpo-32493(276): Fixed *note uuid.uuid1(): da3. on FreeBSD.

   - bpo-33238(277): Add ‘InvalidStateError’ to *note
     concurrent.futures: 24.  ‘Future.set_result’ and
     ‘Future.set_exception’ now raise ‘InvalidStateError’ if the futures
     are not pending or running.  Patch by Jason Haydaman.

   - bpo-33618(278): Finalize and document preliminary and experimental
     TLS 1.3 support with OpenSSL 1.1.1

   - bpo-33625(279): Release GIL on ‘grp.getgrnam’, ‘grp.getgrgid’,
     ‘pwd.getpwnam’ and ‘pwd.getpwuid’ if reentrant variants of these
     functions are available.  Patch by William Grzybowski.

   - bpo-33623(280): Fix possible SIGSGV when asyncio.Future is created
     in __del__

   - bpo-11874(281): Use a better regex when breaking usage into
     wrappable parts.  Avoids bogus assertion errors from custom metavar
     strings.

   - bpo-30877(282): Fixed a bug in the Python implementation of the
     JSON decoder that prevented the cache of parsed strings from
     clearing after finishing the decoding.  Based on patch by c-fos.

   - bpo-33604(283): Remove HMAC default to md5 marked for removal in
     3.8 (removal originally planned in 3.6, bump to 3.8 in PR 7062).

   - bpo-33582(284): Emit a deprecation warning for
     inspect.formatargspec

   - bpo-21145(285): Add ‘functools.cached_property’ decorator, for
     computed properties cached for the life of the instance.

   - bpo-33570(286): Change TLS 1.3 cipher suite settings for
     compatibility with OpenSSL 1.1.1-pre6 and newer.  OpenSSL 1.1.1
     will have TLS 1.3 ciphers enabled by default.

   - bpo-28556(287): Do not simplify arguments to ‘typing.Union’.  Now
     ‘Union[Manager, Employee]’ is not simplified to ‘Employee’ at
     runtime.  Such simplification previously caused several bugs and
     limited possibilities for introspection.

   - bpo-12486(288): *note tokenize.generate_tokens(): 702. is now
     documented as a public API to tokenize unicode strings.  It was
     previously present but undocumented.

   - bpo-33540(289): Add a new ‘block_on_close’ class attribute to
     ‘ForkingMixIn’ and ‘ThreadingMixIn’ classes of *note socketserver:
     d2.

   - bpo-33548(290): tempfile._candidate_tempdir_list should consider
     common TEMP locations

   - bpo-33109(291): argparse subparsers are once again not required by
     default, reverting the change in behavior introduced by
     bpo-26510(292) in 3.7.0a2.

   - bpo-33541(293): Remove unused private method
     ‘_strptime.LocaleTime.__pad’ (a.k.a.  ‘_LocaleTime__pad’).

   - bpo-33536(294): dataclasses.make_dataclass now checks for invalid
     field names and duplicate fields.  Also, added a check for invalid
     field specifications.

   - bpo-33542(295): Prevent ‘uuid.get_node’ from using a DUID instead
     of a MAC on Windows.  Patch by Zvi Effron

   - bpo-26819(296): Fix race condition with
     ‘ReadTransport.resume_reading’ in Windows proactor event loop.

   - Fix failure in ‘typing.get_type_hints()’ when ClassVar was provided
     as a string forward reference.

   - bpo-33516(297): *note unittest.mock.MagicMock: 1091. now supports
     the ‘__round__’ magic method.

   - bpo-28612(298): Added support for Site Maps to urllib’s
     ‘RobotFileParser’ as *note RobotFileParser.site_maps(): 1e0a.
     Patch by Lady Red, based on patch by Peter Wirtz.

   - bpo-28167(299): Remove platform.linux_distribution, which was
     deprecated since 3.5.

   - bpo-33504(300): Switch the default dictionary implementation for
     *note configparser: 26. from *note collections.OrderedDict: 7f4. to
     the standard *note dict: 183. type.

   - bpo-33505(301): Optimize asyncio.ensure_future() by reordering if
     checks: 1.17x faster.

   - bpo-33497(302): Add errors param to cgi.parse_multipart and make an
     encoding in FieldStorage use the given errors (needed for Twisted).
     Patch by Amber Brown.

   - bpo-29235(303): The ‘cProfile.Profile’ class can now be used as a
     context manager.  Patch by Scott Sanderson.

   - bpo-33495(304): Change dataclasses.Fields repr to use the repr of
     each of its members, instead of str.  This makes it more clear what
     each field actually represents.  This is especially true for the
     “type” member.

   - bpo-26103(305): Correct ‘inspect.isdatadescriptor’ to look for
     ‘__set__’ or ‘__delete__’.  Patch by Aaron Hall.

   - bpo-29209(306): Removed the ‘doctype()’ method and the 'html'
     parameter of the constructor of *note XMLParser: c4b.  The
     ‘doctype()’ method defined in a subclass will no longer be called.
     Deprecated methods ‘getchildren()’ and ‘getiterator()’ in the *note
     ElementTree: 12b. module emit now a *note DeprecationWarning: 1a3.
     instead of *note PendingDeprecationWarning: ac8.

   - bpo-33453(307): Fix dataclasses to work if using literal string
     type annotations or if using PEP 563 «Postponed Evaluation of
     Annotations».  Only specific string prefixes are detected for both
     ClassVar («ClassVar» and «typing.ClassVar») and InitVar («InitVar»
     and «dataclasses.InitVar»).

   - bpo-28556(308): Minor fixes in typing module: add annotations to
     ‘NamedTuple.__new__’, pass ‘*args’ and ‘**kwds’ in
     ‘Generic.__new__’.  Original PRs by Paulius Šarka and Chad
     Dombrova.

   - bpo-33365(309): Print the header values besides the header keys
     instead just the header keys if 'debuglevel' is set to >0 in *note
     http.client: 73.  Patch by Marco Strigl.

   - bpo-20087(310): Updated alias mapping with glibc 2.27 supported
     locales.

   - bpo-33422(311): Fix trailing quotation marks getting deleted when
     looking up byte/string literals on pydoc.  Patch by Andrés Delfino.

   - bpo-28167(312): The function ‘platform.linux_distribution’ and
     ‘platform.dist’ now trigger a ‘DeprecationWarning’ and have been
     marked for removal in Python 3.8

   - bpo-33281(313): Fix ctypes.util.find_library regression on macOS.

   - bpo-33311(314): Text and html output generated by cgitb does not
     display parentheses if the current call is done directly in the
     module.  Patch by Stéphane Blondon.

   - bpo-27300(315): The file classes in 'tempfile' now accept an
     'errors' parameter that complements the already existing
     'encoding'.  Patch by Stephan Hohe.

   - bpo-32933(316): *note unittest.mock.mock_open(): 11e9. now supports
     iteration over the file contents.  Patch by Tony Flury.

   - bpo-33217(317): Raise *note TypeError: 198. when looking up
     non-Enum objects in Enum classes and Enum members.

   - bpo-33197(318): Update error message when constructing invalid
     inspect.Parameters Patch by Donghee Na.

   - bpo-33383(319): Fixed crash in the get() method of the *note
     dbm.ndbm: 38. database object when it is called with a single
     argument.

   - bpo-33375(320): The warnings module now finds the Python file
     associated with a warning from the code object, rather than the
     frame’s global namespace.  This is consistent with how tracebacks
     and pdb find filenames, and should work better for dynamically
     executed code.

   - bpo-33336(321): ‘imaplib’ now allows ‘MOVE’ command in
     ‘IMAP4.uid()’ (RFC 6851: IMAP MOVE Extension) and potentially as a
     name of supported method of ‘IMAP4’ object.

   - bpo-32455(322): Added 'jump' parameter to *note dis.stack_effect():
     1133.

   - bpo-27485(323): Rename and deprecate undocumented functions in
     *note urllib.parse(): 110.

   - bpo-33332(324): Add ‘signal.valid_signals()’ to expose the POSIX
     sigfillset() functionality.

   - bpo-33251(325): ‘ConfigParser.items()’ was fixed so that key-value
     pairs passed in via *note vars(): 1e0b. are not included in the
     resulting output.

   - bpo-33329(326): Fix multiprocessing regression on newer glibcs

   - bpo-33334(327): *note dis.stack_effect(): 1133. now supports all
     defined opcodes including NOP and EXTENDED_ARG.

   - bpo-991266(328): Fix quoting of the ‘Comment’ attribute of *note
     http.cookies.SimpleCookie: 1e0c.

   - bpo-33131(329): Upgrade bundled version of pip to 10.0.1.

   - bpo-33308(330): Fixed a crash in the ‘parser’ module when
     converting an ST object to a tree of tuples or lists with
     ‘line_info=False’ and ‘col_info=True’.

   - bpo-23403(331): lib2to3 now uses pickle protocol 4 for pre-computed
     grammars.

   - bpo-33266(332): lib2to3 now recognizes ‘rf'...'’ strings.

   - bpo-11594(333): Ensure line-endings are respected when using
     lib2to3.

   - bpo-33254(334): Have *note importlib.resources.contents(): 504. and
     ‘importlib.abc.ResourceReader.contents()’ return an *note iterable:
     142f. instead of an *note iterator: 4c9.

   - bpo-33265(335): ‘contextlib.ExitStack’ and
     ‘contextlib.AsyncExitStack’ now use a method instead of a wrapper
     function for exit callbacks.

   - bpo-33263(336): Fix FD leak in ‘_SelectorSocketTransport’ Patch by
     Vlad Starostin.

   - bpo-33256(337): Fix display of ‘<module>’ call in the html produced
     by ‘cgitb.html()’.  Patch by Stéphane Blondon.

   - bpo-33144(338): ‘random.Random()’ and its subclassing mechanism got
     optimized to check only once at class/subclass instantiation time
     whether its ‘getrandbits()’ method can be relied on by other
     methods, including ‘randrange()’, for the generation of arbitrarily
     large random integers.  Patch by Wolfgang Maier.

   - bpo-33185(339): Fixed regression when running pydoc with the *note
     -m: 23c. switch.  (The regression was introduced in 3.7.0b3 by the
     resolution of bpo-33053(340))

     This fix also changed pydoc to add ‘os.getcwd()’ to *note sys.path:
     3e4. when necessary, rather than adding ‘"."’.

   - bpo-29613(341): Added support for the ‘SameSite’ cookie flag to the
     ‘http.cookies’ module.

   - bpo-33169(342): Delete entries of ‘None’ in *note
     sys.path_importer_cache: 7fb. when
     ‘importlib.machinery.invalidate_caches()’ is called.

   - bpo-33203(343): ‘random.Random.choice()’ now raises ‘IndexError’
     for empty sequences consistently even when called from subclasses
     without a ‘getrandbits()’ implementation.

   - bpo-33224(344): Update difflib.mdiff() for PEP 479(345).  Convert
     an uncaught StopIteration in a generator into a return-statement.

   - bpo-33209(346): End framing at the end of C implementation of *note
     pickle.Pickler.dump(): 1e0d.

   - bpo-32861(347): The urllib.robotparser’s ‘__str__’ representation
     now includes wildcard entries and the «Crawl-delay» and
     «Request-rate» fields.  Also removes extra newlines that were being
     appended to the end of the string.  Patch by Michael Lazar.

   - bpo-23403(348): ‘DEFAULT_PROTOCOL’ in *note pickle: ab. was bumped
     to 4.  Protocol 4 is described in PEP 3154(349) and available since
     Python 3.4.  It offers better performance and smaller size compared
     to protocol 3 introduced in Python 3.0.

   - bpo-20104(350): Improved error handling and fixed a reference leak
     in *note os.posix_spawn(): 52f.

   - bpo-33106(351): Deleting a key from a read-only dbm database raises
     module specific error instead of KeyError.

   - bpo-33175(352): In dataclasses, Field.__set_name__ now looks up the
     __set_name__ special method on the class, not the instance, of the
     default value.

   - bpo-32380(353): Create functools.singledispatchmethod to support
     generic single dispatch on descriptors and methods.

   - bpo-33141(354): Have Field objects pass through __set_name__ to
     their default values, if they have their own __set_name__.

   - bpo-33096(355): Allow ttk.Treeview.insert to insert iid that has a
     false boolean value.  Note iid=0 and iid=False would be same.
     Patch by Garvit Khatri.

   - bpo-32873(356): Treat type variables and special typing forms as
     immutable by copy and pickle.  This fixes several minor issues and
     inconsistencies, and improves backwards compatibility with Python
     3.6.

   - bpo-33134(357): When computing dataclass’s __hash__, use the lookup
     table to contain the function which returns the __hash__ value.
     This is an improvement over looking up a string, and then testing
     that string to see what to do.

   - bpo-33127(358): The ssl module now compiles with LibreSSL 2.7.1.

   - bpo-32505(359): Raise TypeError if a member variable of a dataclass
     is of type Field, but doesn’t have a type annotation.

   - bpo-33078(360): Fix the failure on OSX caused by the tests relying
     on sem_getvalue

   - bpo-33116(361): Add “Field” to dataclasses.__all__.

   - bpo-32896(362): Fix an error where subclassing a dataclass with a
     field that uses a default_factory would generate an incorrect
     class.

   - bpo-33100(363): Dataclasses: If a field has a default value that’s
     a MemberDescriptorType, then it’s from that field being in
     __slots__, not an actual default value.

   - bpo-32953(364): If a non-dataclass inherits from a frozen
     dataclass, allow attributes to be added to the derived class.  Only
     attributes from the frozen dataclass cannot be assigned to.
     Require all dataclasses in a hierarchy to be either all frozen or
     all non-frozen.

   - bpo-33097(365): Raise RuntimeError when ‘executor.submit’ is called
     during interpreter shutdown.

   - bpo-32968(366): Modulo and floor division involving Fraction and
     float should return float.

   - bpo-33061(367): Add missing ‘NoReturn’ to ‘__all__’ in typing.py

   - bpo-33078(368): Fix the size handling in multiprocessing.Queue when
     a pickling error occurs.

   - bpo-33064(369): lib2to3 now properly supports trailing commas after
     ‘*args’ and ‘**kwargs’ in function signatures.

   - bpo-33056(370): FIX properly close leaking fds in
     concurrent.futures.ProcessPoolExecutor.

   - bpo-33021(371): Release the GIL during fstat() calls, avoiding hang
     of all threads when calling mmap.mmap(), os.urandom(), and
     random.seed().  Patch by Nir Soffer.

   - bpo-31804(372): Avoid failing in multiprocessing.Process if the
     standard streams are closed or None at exit.

   - bpo-33034(373): Providing an explicit error message when casting
     the port property to anything that is not an integer value using
     ‘urlparse()’ and ‘urlsplit()’.  Patch by Matt Eaton.

   - bpo-30249(374): Improve struct.unpack_from() exception messages for
     problems with the buffer size and offset.

   - bpo-33037(375): Skip sending/receiving data after SSL transport
     closing.

   - bpo-27683(376): Fix a regression in *note ipaddress: 84. that
     result of ‘hosts()’ is empty when the network is constructed by a
     tuple containing an integer mask and only 1 bit left for addresses.

   - bpo-22674(377): Add the strsignal() function in the signal module
     that returns the system description of the given signal, as
     returned by strsignal(3).

   - bpo-32999(378): Fix C implementation of ‘ABC.__subclasscheck__(cls,
     subclass)’ crashed when ‘subclass’ is not a type object.

   - bpo-33009(379): Fix inspect.signature() for single-parameter
     partialmethods.

   - bpo-32969(380): Expose several missing constants in zlib and fix
     corresponding documentation.

   - bpo-32056(381): Improved exceptions raised for invalid number of
     channels and sample width when read an audio file in modules
     ‘aifc’, *note wave: 119. and ‘sunau’.

   - bpo-32970(382): Improved disassembly of the MAKE_FUNCTION
     instruction.

   - bpo-32844(383): Fix wrong redirection of a low descriptor (0 or 1)
     to stderr in subprocess if another low descriptor is closed.

   - bpo-32960(384): For dataclasses, disallow inheriting frozen from
     non-frozen classes, and also disallow inheriting non-frozen from
     frozen classes.  This restriction will be relaxed at a future date.

   - bpo-32713(385): Fixed tarfile.itn handling of out-of-bounds float
     values.  Patch by Joffrey Fuhrer.

   - bpo-32257(386): The ssl module now contains OP_NO_RENEGOTIATION
     constant, available with OpenSSL 1.1.0h or 1.1.1.

   - bpo-32951(387): Direct instantiation of SSLSocket and SSLObject
     objects is now prohibited.  The constructors were never documented,
     tested, or designed as public constructors.  Users were suppose to
     use ssl.wrap_socket() or SSLContext.

   - bpo-32929(388): Remove the tri-state parameter «hash», and add the
     boolean «unsafe_hash».  If unsafe_hash is True, add a __hash__
     function, but if a __hash__ exists, raise TypeError.  If
     unsafe_hash is False, add a __hash__ based on the values of eq= and
     frozen=.  The unsafe_hash=False behavior is the same as the old
     hash=None behavior.  unsafe_hash=False is the default, just as
     hash=None used to be.

   - bpo-32947(389): Add OP_ENABLE_MIDDLEBOX_COMPAT and test workaround
     for TLSv1.3 for future compatibility with OpenSSL 1.1.1.

   - bpo-32146(390): Document the interaction between frozen executables
     and the spawn and forkserver start methods in multiprocessing.

   - bpo-30622(391): The ssl module now detects missing NPN support in
     LibreSSL.

   - bpo-32922(392): dbm.open() now encodes filename with the filesystem
     encoding rather than default encoding.

   - bpo-32759(393): Free unused arenas in multiprocessing.heap.

   - bpo-32859(394): In ‘os.dup2’, don’t check every call whether the
     ‘dup3’ syscall exists or not.

   - bpo-32556(395): nt._getfinalpathname, nt._getvolumepathname and
     nt._getdiskusage now correctly convert from bytes.

   - bpo-21060(396): Rewrite confusing message from setup.py upload from
     «No dist file created in earlier command» to the more helpful «Must
     create and upload files in one command».

   - bpo-32857(397): In *note tkinter: f6, ‘after_cancel(None)’ now
     raises a *note ValueError: 2ec. instead of canceling the first
     scheduled function.  Patch by Cheryl Sabella.

   - bpo-32852(398): Make sure sys.argv remains as a list when running
     trace.

   - bpo-31333(399): ‘_abc’ module is added.  It is a speedup module
     with C implementations for various functions and methods in ‘abc’.
     Creating an ABC subclass and calling ‘isinstance’ or ‘issubclass’
     with an ABC subclass are up to 1.5x faster.  In addition, this
     makes Python start-up up to 10% faster.

     Note that the new implementation hides internal registry and
     caches, previously accessible via private attributes
     ‘_abc_registry’, ‘_abc_cache’, and ‘_abc_negative_cache’.  There
     are three debugging helper methods that can be used instead
     ‘_dump_registry’, ‘_abc_registry_clear’, and ‘_abc_caches_clear’.

   - bpo-32841(400): Fixed ‘asyncio.Condition’ issue which silently
     ignored cancellation after notifying and cancelling a conditional
     lock.  Patch by Bar Harel.

   - bpo-32819(401): ssl.match_hostname() has been simplified and no
     longer depends on re and ipaddress module for wildcard and IP
     addresses.  Error reporting for invalid wildcards has been
     improved.

   - bpo-19675(402): ‘multiprocessing.Pool’ no longer leaks processes if
     its initialization fails.

   - bpo-32394(403): socket: Remove
     TCP_FASTOPEN,TCP_KEEPCNT,TCP_KEEPIDLE,TCP_KEEPINTVL flags on older
     version Windows during run-time.

   - bpo-31787(404): Fixed refleaks of ‘__init__()’ methods in various
     modules.  (Contributed by Oren Milman)

   - bpo-30157(405): Fixed guessing quote and delimiter in
     csv.Sniffer.sniff() when only the last field is quoted.  Patch by
     Jake Davis.

   - bpo-30688(406): Added support of ‘\N{name}’ escapes in regular
     expressions.  Based on patch by Jonathan Eunice.

   - bpo-32792(407): collections.ChainMap() preserves the order of the
     underlying mappings.

   - bpo-32775(408): *note fnmatch.translate(): 1837. no longer produces
     patterns which contain set operations.  Sets starting with “[” or
     containing “–”, “&&”, “~~” or “||” will be interpreted differently
     in regular expressions in future versions.  Currently they emit
     warnings.  fnmatch.translate() now avoids producing patterns
     containing such sets by accident.

   - bpo-32622(409): Implement native fast sendfile for Windows proactor
     event loop.

   - bpo-32777(410): Fix a rare but potential pre-exec child process
     deadlock in subprocess on POSIX systems when marking file
     descriptors inheritable on exec in the child process.  This bug
     appears to have been introduced in 3.4.

   - bpo-32647(411): The ctypes module used to depend on indirect
     linking for dlopen.  The shared extension is now explicitly linked
     against libdl on platforms with dl.

   - bpo-32749(412): A *note dbm.dumb: 36. database opened with flags
     “r” is now read-only.  *note dbm.dumb.open(): c8f. with flags “r”
     and “w” no longer creates a database if it does not exist.

   - bpo-32741(413): Implement ‘asyncio.TimerHandle.when()’ method.

   - bpo-32691(414): Use mod_spec.parent when running modules with pdb

   - bpo-32734(415): Fixed ‘asyncio.Lock()’ safety issue which allowed
     acquiring and locking the same lock multiple times, without it
     being free.  Patch by Bar Harel.

   - bpo-32727(416): Do not include name field in SMTP envelope from
     address.  Patch by Stéphane Wirtel

   - bpo-31453(417): Add TLSVersion constants and
     SSLContext.maximum_version / minimum_version attributes.  The new
     API wraps OpenSSL 1.1
     ‘https://web.archive.org/web/20180309043602/https://www.openssl.org/docs/man1.1.0/ssl/SSL_CTX_set_min_proto_version.html’
     feature.

   - bpo-24334(418): Internal implementation details of ssl module were
     cleaned up.  The SSLSocket has one less layer of indirection.
     Owner and session information are now handled by the SSLSocket and
     SSLObject constructor.  Channel binding implementation has been
     simplified.

   - bpo-31848(419): Fix the error handling in Aifc_read.initfp() when
     the SSND chunk is not found.  Patch by Zackery Spytz.

   - bpo-32585(420): Add Ttk spinbox widget to *note tkinter.ttk: ff.
     Patch by Alan D Moore.

   - bpo-32512(421): *note profile: b4. CLI accepts ‘-m module_name’ as
     an alternative to script path.

   - bpo-8525(422): help() on a type now displays builtin subclasses.
     This is intended primarily to help with notification of more
     specific exception subclasses.

     Patch by Sanyam Khurana.

   - bpo-31639(423): http.server now exposes a ThreadingHTTPServer class
     and uses it when the module is run with ‘-m’ to cope with web
     browsers pre-opening sockets.

   - bpo-29877(424): compileall: import ProcessPoolExecutor only when
     needed, preventing hangs on low resource platforms

   - bpo-32221(425): Various functions returning tuple containing IPv6
     addresses now omit ‘%scope’ part since the same information is
     already encoded in 'scopeid' tuple item.  Especially this speeds up
     ‘socket.recvfrom()’ when it receives multicast packet since useless
     resolving of network interface name is omitted.

   - bpo-32147(426): *note binascii.unhexlify(): 1e0e. is now up to 2
     times faster.  Patch by Sergey Fedoseev.

   - bpo-30693(427): The TarFile class now recurses directories in a
     reproducible way.

   - bpo-30693(428): The ZipFile class now recurses directories in a
     reproducible way.

   - bpo-31680(429): Added *note curses.ncurses_version: bdc.

   - bpo-31908(430): Fix output of cover files for ‘trace’ module
     command-line tool.  Previously emitted cover files only when
     ‘--missing’ option was used.  Patch by Michael Selik.

   - bpo-31608(431): Raise a ‘TypeError’ instead of crashing if a
     ‘collections.deque’ subclass returns a non-deque from ‘__new__’.
     Patch by Oren Milman.

   - bpo-31425(432): Add support for sockets of the AF_QIPCRTR address
     family, supported by the Linux kernel.  This is used to communicate
     with services, such as GPS or radio, running on Qualcomm devices.
     Patch by Bjorn Andersson.

   - bpo-22005(433): Implemented unpickling instances of *note datetime:
     4e3, *note date: 1fa. and *note time: 1fb. pickled by Python 2.
     ‘encoding='latin1'’ should be used for successful decoding.

   - bpo-27645(434): *note sqlite3.Connection: 54e. now exposes a *note
     backup: d75. method, if the underlying SQLite library is at version
     3.6.11 or higher.  Patch by Lele Gaifax.

   - bpo-16865(435): Support arrays >=2GiB in *note ctypes: 2e.  Patch
     by Segev Finer.

   - bpo-31508(436): Removed support of arguments in
     ‘tkinter.ttk.Treeview.selection’.  It was deprecated in 3.6.  Use
     specialized methods like ‘selection_set’ for changing the
     selection.

   - bpo-29456(437): Fix bugs in hangul normalization: u1176, u11a7 and
     u11c3

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35845

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35864

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35537

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35847

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35813

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35780

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35537

   (8) https://bugs.python.org/issue?@action=redirect&bpo=23846

   (9) https://bugs.python.org/issue?@action=redirect&bpo=34323

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35674

   (11) https://bugs.python.org/issue?@action=redirect&bpo=35733

   (12) https://bugs.python.org/issue?@action=redirect&bpo=35726

   (13) https://bugs.python.org/issue?@action=redirect&bpo=35719

   (14) https://bugs.python.org/issue?@action=redirect&bpo=35717

   (15) https://bugs.python.org/issue?@action=redirect&bpo=35699

   (16) https://bugs.python.org/issue?@action=redirect&bpo=32710

   (17) https://bugs.python.org/issue?@action=redirect&bpo=35702

   (18) https://bugs.python.org/issue?@action=redirect&bpo=32710

   (19) https://bugs.python.org/issue?@action=redirect&bpo=35682

   (20) https://bugs.python.org/issue?@action=redirect&bpo=35283

   (21) https://bugs.python.org/issue?@action=redirect&bpo=35664

   (22) https://bugs.python.org/issue?@action=redirect&bpo=35643

   (23) https://bugs.python.org/issue?@action=redirect&bpo=35619

   (24) https://bugs.python.org/issue?@action=redirect&bpo=28503

   (25) https://bugs.python.org/issue?@action=redirect&bpo=35614

   (26) https://bugs.python.org/issue?@action=redirect&bpo=35568

   (27) https://bugs.python.org/issue?@action=redirect&bpo=35588

   (28) https://bugs.python.org/issue?@action=redirect&bpo=35585

   (29) https://bugs.python.org/issue?@action=redirect&bpo=30561

   (30) https://bugs.python.org/issue?@action=redirect&bpo=35537

   (31) https://bugs.python.org/issue?@action=redirect&bpo=35526

   (32) https://bugs.python.org/issue?@action=redirect&bpo=35523

   (33) https://bugs.python.org/issue?@action=redirect&bpo=31784

   (34) https://bugs.python.org/issue?@action=redirect&bpo=35513

   (35) https://bugs.python.org/issue?@action=redirect&bpo=35502

   (36) https://bugs.python.org/issue?@action=redirect&bpo=35348

   (37) https://bugs.python.org/issue?@action=redirect&bpo=35491

   (38) https://bugs.python.org/issue?@action=redirect&bpo=35477

   (39) https://bugs.python.org/issue?@action=redirect&bpo=31446

   (40) https://bugs.python.org/issue?@action=redirect&bpo=35471

   (41) https://bugs.python.org/issue?@action=redirect&bpo=23057

   (42) https://bugs.python.org/issue?@action=redirect&bpo=35052

   (43) https://bugs.python.org/issue?@action=redirect&bpo=20239

   (44) https://bugs.python.org/issue?@action=redirect&bpo=17185

   (45) https://bugs.python.org/issue?@action=redirect&bpo=35445

   (46) https://bugs.python.org/issue?@action=redirect&bpo=35415

   (47) https://bugs.python.org/issue?@action=redirect&bpo=35424

   (48) https://bugs.python.org/issue?@action=redirect&bpo=35330

   (49) https://bugs.python.org/issue?@action=redirect&bpo=35346

   (50) https://bugs.python.org/issue?@action=redirect&bpo=10496

   (51) https://bugs.python.org/issue?@action=redirect&bpo=10496

   (52) https://bugs.python.org/issue?@action=redirect&bpo=35389

   (53) https://bugs.python.org/issue?@action=redirect&bpo=35394

   (54) https://bugs.python.org/issue?@action=redirect&bpo=35310

   (55) https://bugs.python.org/issue?@action=redirect&bpo=35380

   (56) https://bugs.python.org/issue?@action=redirect&bpo=35341

   (57) https://bugs.python.org/issue?@action=redirect&bpo=35371

   (58) https://bugs.python.org/issue?@action=redirect&bpo=35346

   (59) https://bugs.python.org/issue?@action=redirect&bpo=35066

   (60) https://bugs.python.org/issue?@action=redirect&bpo=35345

   (61) https://bugs.python.org/issue?@action=redirect&bpo=35344

   (62) https://bugs.python.org/issue?@action=redirect&bpo=35312

   (63) https://bugs.python.org/issue?@action=redirect&bpo=35308

   (64) https://bugs.python.org/issue?@action=redirect&bpo=24746

   (65) https://bugs.python.org/issue?@action=redirect&bpo=28604

   (66) https://bugs.python.org/issue?@action=redirect&bpo=35277

   (67) https://bugs.python.org/issue?@action=redirect&bpo=24209

   (68) https://bugs.python.org/issue?@action=redirect&bpo=35226

   (69) https://bugs.python.org/issue?@action=redirect&bpo=29564

   (70) https://bugs.python.org/issue?@action=redirect&bpo=35189

   (71) https://bugs.python.org/issue?@action=redirect&bpo=30064

   (72) https://bugs.python.org/issue?@action=redirect&bpo=35186

   (73) https://bugs.python.org/issue?@action=redirect&bpo=35152

   (74) https://bugs.python.org/issue?@action=redirect&bpo=35062

   (75) https://bugs.python.org/issue?@action=redirect&bpo=35065

   (76) https://bugs.python.org/issue?@action=redirect&bpo=34160

   (77) https://bugs.python.org/issue?@action=redirect&bpo=35079

   (78) https://bugs.python.org/issue?@action=redirect&bpo=33710

   (79) https://bugs.python.org/issue?@action=redirect&bpo=35017

   (80) https://bugs.python.org/issue?@action=redirect&bpo=35024

   (81) https://bugs.python.org/issue?@action=redirect&bpo=35047

   (82) https://bugs.python.org/issue?@action=redirect&bpo=31047

   (83) https://bugs.python.org/issue?@action=redirect&bpo=35053

   (84) https://bugs.python.org/issue?@action=redirect&bpo=31553

   (85) https://bugs.python.org/issue?@action=redirect&bpo=34794

   (86) https://bugs.python.org/issue?@action=redirect&bpo=34909

   (87) https://bugs.python.org/issue?@action=redirect&bpo=35022

   (88) https://bugs.python.org/issue?@action=redirect&bpo=35008

   (89) https://bugs.python.org/issue?@action=redirect&bpo=23420

   (90) https://bugs.python.org/issue?@action=redirect&bpo=33947

   (91) https://bugs.python.org/issue?@action=redirect&bpo=34890

   (92) https://bugs.python.org/issue?@action=redirect&bpo=34521

   (93) https://datatracker.ietf.org/doc/html/rfc3542.html

   (94) https://bugs.python.org/issue?@action=redirect&bpo=31522

   (95) https://bugs.python.org/issue?@action=redirect&bpo=34970

   (96) https://bugs.python.org/issue?@action=redirect&bpo=34969

   (97) https://bugs.python.org/issue?@action=redirect&bpo=16965

   (98) https://bugs.python.org/issue?@action=redirect&bpo=34966

   (99) https://bugs.python.org/issue?@action=redirect&bpo=34926

   (100) https://bugs.python.org/issue?@action=redirect&bpo=23831

   (101) https://bugs.python.org/issue?@action=redirect&bpo=34941

   (102) https://bugs.python.org/issue?@action=redirect&bpo=32680

   (103) https://bugs.python.org/issue?@action=redirect&bpo=34769

   (104) https://bugs.python.org/issue?@action=redirect&bpo=34936

   (105) https://bugs.python.org/issue?@action=redirect&bpo=34829

   (106) https://bugs.python.org/issue?@action=redirect&bpo=34911

   (107) https://bugs.python.org/issue?@action=redirect&bpo=34922

   (108) https://bugs.python.org/issue?@action=redirect&bpo=34925

   (109) https://bugs.python.org/issue?@action=redirect&bpo=34900

   (110) https://bugs.python.org/issue?@action=redirect&bpo=34844

   (111) https://bugs.python.org/issue?@action=redirect&bpo=34897

   (112) https://bugs.python.org/issue?@action=redirect&bpo=34871

   (113) https://bugs.python.org/issue?@action=redirect&bpo=34898

   (114) https://bugs.python.org/issue?@action=redirect&bpo=28441

   (115) https://bugs.python.org/issue?@action=redirect&bpo=34866

   (116) https://bugs.python.org/issue?@action=redirect&bpo=34711

   (117) https://bugs.python.org/issue?@action=redirect&bpo=34872

   (118) https://bugs.python.org/issue?@action=redirect&bpo=34849

   (119) https://bugs.python.org/issue?@action=redirect&bpo=34022

   (120) https://bugs.python.org/issue?@action=redirect&bpo=34819

   (121) https://bugs.python.org/issue?@action=redirect&bpo=34758

   (122) https://bugs.python.org/issue?@action=redirect&bpo=34789

   (123) https://bugs.python.org/issue?@action=redirect&bpo=34334

   (124) https://bugs.python.org/issue?@action=redirect&bpo=34687

   (125) https://bugs.python.org/issue?@action=redirect&bpo=5950

   (126) https://bugs.python.org/issue?@action=redirect&bpo=32892

   (127) https://bugs.python.org/issue?@action=redirect&bpo=34728

   (128) https://bugs.python.org/issue?@action=redirect&bpo=34738

   (129) https://bugs.python.org/issue?@action=redirect&bpo=34659

   (130) https://bugs.python.org/issue?@action=redirect&bpo=29577

   (131) https://bugs.python.org/issue?@action=redirect&bpo=34670

   (132) https://bugs.python.org/issue?@action=redirect&bpo=32718

   (133) https://bugs.python.org/issue?@action=redirect&bpo=31177

   (134) https://bugs.python.org/issue?@action=redirect&bpo=34672

   (135) https://bugs.python.org/issue?@action=redirect&bpo=34666

   (136) https://bugs.python.org/issue?@action=redirect&bpo=6721

   (137) https://bugs.python.org/issue?@action=redirect&bpo=34658

   (138) https://bugs.python.org/issue?@action=redirect&bpo=34652

   (139) https://bugs.python.org/issue?@action=redirect&bpo=34638

   (140) https://bugs.python.org/issue?@action=redirect&bpo=34536

   (141) https://bugs.python.org/issue?@action=redirect&bpo=34636

   (142) https://bugs.python.org/issue?@action=redirect&bpo=24412

   (143) https://bugs.python.org/issue?@action=redirect&bpo=34630

   (144) https://bugs.python.org/issue?@action=redirect&bpo=32490

   (145) https://bugs.python.org/issue?@action=redirect&bpo=34363

   (146) https://bugs.python.org/issue?@action=redirect&bpo=34625

   (147) https://bugs.python.org/issue?@action=redirect&bpo=32270

   (148) https://bugs.python.org/issue?@action=redirect&bpo=34622

   (149) https://bugs.python.org/issue?@action=redirect&bpo=34610

   (150) https://bugs.python.org/issue?@action=redirect&bpo=34421

   (151) https://bugs.python.org/issue?@action=redirect&bpo=34604

   (152) https://bugs.python.org/issue?@action=redirect&bpo=30977

   (153) https://bugs.python.org/issue?@action=redirect&bpo=34574

   (154) https://bugs.python.org/issue?@action=redirect&bpo=8110

   (155) https://bugs.python.org/issue?@action=redirect&bpo=34530

   (156) https://bugs.python.org/issue?@action=redirect&bpo=34563

   (157) https://bugs.python.org/issue?@action=redirect&bpo=34558

   (158) https://bugs.python.org/issue?@action=redirect&bpo=34282

   (159) https://bugs.python.org/issue?@action=redirect&bpo=22872

   (160) https://bugs.python.org/issue?@action=redirect&bpo=34515

   (161) https://peps.python.org/pep-3131/

   (162) https://bugs.python.org/issue?@action=redirect&bpo=13312

   (163) https://bugs.python.org/issue?@action=redirect&bpo=34472

   (164) https://bugs.python.org/issue?@action=redirect&bpo=34454

   (165) https://bugs.python.org/issue?@action=redirect&bpo=6700

   (166) https://bugs.python.org/issue?@action=redirect&bpo=34171

   (167) https://bugs.python.org/issue?@action=redirect&bpo=34441

   (168) https://bugs.python.org/issue?@action=redirect&bpo=34427

   (169) https://bugs.python.org/issue?@action=redirect&bpo=34412

   (170) https://bugs.python.org/issue?@action=redirect&bpo=20849

   (171) https://bugs.python.org/issue?@action=redirect&bpo=31715

   (172) https://bugs.python.org/issue?@action=redirect&bpo=34384

   (173) https://bugs.python.org/issue?@action=redirect&bpo=22602

   (174) https://bugs.python.org/issue?@action=redirect&bpo=2122

   (175) https://bugs.python.org/issue?@action=redirect&bpo=34341

   (176) https://bugs.python.org/issue?@action=redirect&bpo=34333

   (177) https://bugs.python.org/issue?@action=redirect&bpo=18540

   (178) https://bugs.python.org/issue?@action=redirect&bpo=26502

   (179) https://bugs.python.org/issue?@action=redirect&bpo=34318

   (180) https://bugs.python.org/issue?@action=redirect&bpo=9372

   (181) https://bugs.python.org/issue?@action=redirect&bpo=33613

   (182) https://bugs.python.org/issue?@action=redirect&bpo=34248

   (183) https://bugs.python.org/issue?@action=redirect&bpo=33089

   (184) https://bugs.python.org/issue?@action=redirect&bpo=34246

   (185) https://bugs.python.org/issue?@action=redirect&bpo=31047

   (186) https://bugs.python.org/issue?@action=redirect&bpo=32321

   (187) https://bugs.python.org/issue?@action=redirect&bpo=34270

   (188) https://bugs.python.org/issue?@action=redirect&bpo=34263

   (189) https://bugs.python.org/issue?@action=redirect&bpo=34035

   (190) https://bugs.python.org/issue?@action=redirect&bpo=32215

   (191) https://bugs.python.org/issue?@action=redirect&bpo=34075

   (192) https://bugs.python.org/issue?@action=redirect&bpo=34251

   (193) https://bugs.python.org/issue?@action=redirect&bpo=19891

   (194) https://bugs.python.org/issue?@action=redirect&bpo=33089

   (195) https://bugs.python.org/issue?@action=redirect&bpo=34228

   (196) https://bugs.python.org/issue?@action=redirect&bpo=13041

   (197) https://bugs.python.org/issue?@action=redirect&bpo=34213

   (198) https://bugs.python.org/issue?@action=redirect&bpo=34052

   (199) https://bugs.python.org/issue?@action=redirect&bpo=34197

   (200) https://bugs.python.org/issue?@action=redirect&bpo=32788

   (201) https://bugs.python.org/issue?@action=redirect&bpo=21446

   (202) https://bugs.python.org/issue?@action=redirect&bpo=940286

   (203) https://bugs.python.org/issue?@action=redirect&bpo=34164

   (204) https://bugs.python.org/issue?@action=redirect&bpo=33729

   (205) https://bugs.python.org/issue?@action=redirect&bpo=34097

   (206) https://bugs.python.org/issue?@action=redirect&bpo=34108

   (207) https://bugs.python.org/issue?@action=redirect&bpo=34070

   (208) https://bugs.python.org/issue?@action=redirect&bpo=27494

   (209) https://bugs.python.org/issue?@action=redirect&bpo=27494

   (210) https://bugs.python.org/issue?@action=redirect&bpo=33967

   (211) https://bugs.python.org/issue?@action=redirect&bpo=34041

   (212) https://bugs.python.org/issue?@action=redirect&bpo=34056

   (213) https://peps.python.org/pep-0552/

   (214) https://bugs.python.org/issue?@action=redirect&bpo=34054

   (215) https://bugs.python.org/issue?@action=redirect&bpo=34043

   (216) https://bugs.python.org/issue?@action=redirect&bpo=34044

   (217) https://bugs.python.org/issue?@action=redirect&bpo=34010

   (218) https://bugs.python.org/issue?@action=redirect&bpo=34019

   (219) https://bugs.python.org/issue?@action=redirect&bpo=34003

   (220) https://bugs.python.org/issue?@action=redirect&bpo=33978

   (221) https://bugs.python.org/issue?@action=redirect&bpo=14117

   (222) https://bugs.python.org/issue?@action=redirect&bpo=33974

   (223) https://bugs.python.org/issue?@action=redirect&bpo=27500

   (224) https://bugs.python.org/issue?@action=redirect&bpo=24567

   (225) https://bugs.python.org/issue?@action=redirect&bpo=33871

   (226) https://bugs.python.org/issue?@action=redirect&bpo=25007

   (227) https://bugs.python.org/issue?@action=redirect&bpo=33929

   (228) https://bugs.python.org/issue?@action=redirect&bpo=33899

   (229) https://bugs.python.org/issue?@action=redirect&bpo=33897

   (230) https://bugs.python.org/issue?@action=redirect&bpo=33695

   (231) https://bugs.python.org/issue?@action=redirect&bpo=33695

   (232) https://bugs.python.org/issue?@action=redirect&bpo=33916

   (233) https://bugs.python.org/issue?@action=redirect&bpo=32568

   (234) https://bugs.python.org/issue?@action=redirect&bpo=33833

   (235) https://bugs.python.org/issue?@action=redirect&bpo=33663

   (236) https://bugs.python.org/issue?@action=redirect&bpo=33721

   (237) https://bugs.python.org/issue?@action=redirect&bpo=26544

   (238) https://bugs.python.org/issue?@action=redirect&bpo=33843

   (239) https://bugs.python.org/issue?@action=redirect&bpo=33842

   (240) https://bugs.python.org/issue?@action=redirect&bpo=30167

   (241) https://bugs.python.org/issue?@action=redirect&bpo=33805

   (242) https://bugs.python.org/issue?@action=redirect&bpo=33687

   (243) https://bugs.python.org/issue?@action=redirect&bpo=33812

   (244) https://bugs.python.org/issue?@action=redirect&bpo=32108

   (245) https://bugs.python.org/issue?@action=redirect&bpo=27397

   (246) https://bugs.python.org/issue?@action=redirect&bpo=33578

   (247) https://bugs.python.org/issue?@action=redirect&bpo=30805

   (248) https://bugs.python.org/issue?@action=redirect&bpo=33476

   (249) https://bugs.python.org/issue?@action=redirect&bpo=33694

   (250) https://bugs.python.org/issue?@action=redirect&bpo=32493

   (251) https://bugs.python.org/issue?@action=redirect&bpo=33792

   (252) https://bugs.python.org/issue?@action=redirect&bpo=33274

   (253) https://bugs.python.org/issue?@action=redirect&bpo=33778

   (254) https://bugs.python.org/issue?@action=redirect&bpo=33165

   (255) https://bugs.python.org/issue?@action=redirect&bpo=33770

   (256) https://bugs.python.org/issue?@action=redirect&bpo=33769

   (257) https://bugs.python.org/issue?@action=redirect&bpo=33767

   (258) https://bugs.python.org/issue?@action=redirect&bpo=33734

   (259) https://bugs.python.org/issue?@action=redirect&bpo=31014

   (260) https://bugs.python.org/issue?@action=redirect&bpo=2504

   (261) https://bugs.python.org/issue?@action=redirect&bpo=33197

   (262) https://bugs.python.org/issue?@action=redirect&bpo=32751

   (263) https://bugs.python.org/issue?@action=redirect&bpo=32684

   (264) https://bugs.python.org/issue?@action=redirect&bpo=33654

   (265) https://bugs.python.org/issue?@action=redirect&bpo=33674

   (266) https://bugs.python.org/issue?@action=redirect&bpo=33671

   (267) https://bugs.python.org/issue?@action=redirect&bpo=25427

   (268) https://bugs.python.org/issue?@action=redirect&bpo=33674

   (269) https://bugs.python.org/issue?@action=redirect&bpo=31647

   (270) https://bugs.python.org/issue?@action=redirect&bpo=32610

   (271) https://bugs.python.org/issue?@action=redirect&bpo=32410

   (272) https://bugs.python.org/issue?@action=redirect&bpo=33469

   (273) https://bugs.python.org/issue?@action=redirect&bpo=33672

   (274) https://bugs.python.org/issue?@action=redirect&bpo=33654

   (275) https://bugs.python.org/issue?@action=redirect&bpo=33652

   (276) https://bugs.python.org/issue?@action=redirect&bpo=32493

   (277) https://bugs.python.org/issue?@action=redirect&bpo=33238

   (278) https://bugs.python.org/issue?@action=redirect&bpo=33618

   (279) https://bugs.python.org/issue?@action=redirect&bpo=33625

   (280) https://bugs.python.org/issue?@action=redirect&bpo=33623

   (281) https://bugs.python.org/issue?@action=redirect&bpo=11874

   (282) https://bugs.python.org/issue?@action=redirect&bpo=30877

   (283) https://bugs.python.org/issue?@action=redirect&bpo=33604

   (284) https://bugs.python.org/issue?@action=redirect&bpo=33582

   (285) https://bugs.python.org/issue?@action=redirect&bpo=21145

   (286) https://bugs.python.org/issue?@action=redirect&bpo=33570

   (287) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (288) https://bugs.python.org/issue?@action=redirect&bpo=12486

   (289) https://bugs.python.org/issue?@action=redirect&bpo=33540

   (290) https://bugs.python.org/issue?@action=redirect&bpo=33548

   (291) https://bugs.python.org/issue?@action=redirect&bpo=33109

   (292) https://bugs.python.org/issue?@action=redirect&bpo=26510

   (293) https://bugs.python.org/issue?@action=redirect&bpo=33541

   (294) https://bugs.python.org/issue?@action=redirect&bpo=33536

   (295) https://bugs.python.org/issue?@action=redirect&bpo=33542

   (296) https://bugs.python.org/issue?@action=redirect&bpo=26819

   (297) https://bugs.python.org/issue?@action=redirect&bpo=33516

   (298) https://bugs.python.org/issue?@action=redirect&bpo=28612

   (299) https://bugs.python.org/issue?@action=redirect&bpo=28167

   (300) https://bugs.python.org/issue?@action=redirect&bpo=33504

   (301) https://bugs.python.org/issue?@action=redirect&bpo=33505

   (302) https://bugs.python.org/issue?@action=redirect&bpo=33497

   (303) https://bugs.python.org/issue?@action=redirect&bpo=29235

   (304) https://bugs.python.org/issue?@action=redirect&bpo=33495

   (305) https://bugs.python.org/issue?@action=redirect&bpo=26103

   (306) https://bugs.python.org/issue?@action=redirect&bpo=29209

   (307) https://bugs.python.org/issue?@action=redirect&bpo=33453

   (308) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (309) https://bugs.python.org/issue?@action=redirect&bpo=33365

   (310) https://bugs.python.org/issue?@action=redirect&bpo=20087

   (311) https://bugs.python.org/issue?@action=redirect&bpo=33422

   (312) https://bugs.python.org/issue?@action=redirect&bpo=28167

   (313) https://bugs.python.org/issue?@action=redirect&bpo=33281

   (314) https://bugs.python.org/issue?@action=redirect&bpo=33311

   (315) https://bugs.python.org/issue?@action=redirect&bpo=27300

   (316) https://bugs.python.org/issue?@action=redirect&bpo=32933

   (317) https://bugs.python.org/issue?@action=redirect&bpo=33217

   (318) https://bugs.python.org/issue?@action=redirect&bpo=33197

   (319) https://bugs.python.org/issue?@action=redirect&bpo=33383

   (320) https://bugs.python.org/issue?@action=redirect&bpo=33375

   (321) https://bugs.python.org/issue?@action=redirect&bpo=33336

   (322) https://bugs.python.org/issue?@action=redirect&bpo=32455

   (323) https://bugs.python.org/issue?@action=redirect&bpo=27485

   (324) https://bugs.python.org/issue?@action=redirect&bpo=33332

   (325) https://bugs.python.org/issue?@action=redirect&bpo=33251

   (326) https://bugs.python.org/issue?@action=redirect&bpo=33329

   (327) https://bugs.python.org/issue?@action=redirect&bpo=33334

   (328) https://bugs.python.org/issue?@action=redirect&bpo=991266

   (329) https://bugs.python.org/issue?@action=redirect&bpo=33131

   (330) https://bugs.python.org/issue?@action=redirect&bpo=33308

   (331) https://bugs.python.org/issue?@action=redirect&bpo=23403

   (332) https://bugs.python.org/issue?@action=redirect&bpo=33266

   (333) https://bugs.python.org/issue?@action=redirect&bpo=11594

   (334) https://bugs.python.org/issue?@action=redirect&bpo=33254

   (335) https://bugs.python.org/issue?@action=redirect&bpo=33265

   (336) https://bugs.python.org/issue?@action=redirect&bpo=33263

   (337) https://bugs.python.org/issue?@action=redirect&bpo=33256

   (338) https://bugs.python.org/issue?@action=redirect&bpo=33144

   (339) https://bugs.python.org/issue?@action=redirect&bpo=33185

   (340) https://bugs.python.org/issue?@action=redirect&bpo=33053

   (341) https://bugs.python.org/issue?@action=redirect&bpo=29613

   (342) https://bugs.python.org/issue?@action=redirect&bpo=33169

   (343) https://bugs.python.org/issue?@action=redirect&bpo=33203

   (344) https://bugs.python.org/issue?@action=redirect&bpo=33224

   (345) https://peps.python.org/pep-0479/

   (346) https://bugs.python.org/issue?@action=redirect&bpo=33209

   (347) https://bugs.python.org/issue?@action=redirect&bpo=32861

   (348) https://bugs.python.org/issue?@action=redirect&bpo=23403

   (349) https://peps.python.org/pep-3154/

   (350) https://bugs.python.org/issue?@action=redirect&bpo=20104

   (351) https://bugs.python.org/issue?@action=redirect&bpo=33106

   (352) https://bugs.python.org/issue?@action=redirect&bpo=33175

   (353) https://bugs.python.org/issue?@action=redirect&bpo=32380

   (354) https://bugs.python.org/issue?@action=redirect&bpo=33141

   (355) https://bugs.python.org/issue?@action=redirect&bpo=33096

   (356) https://bugs.python.org/issue?@action=redirect&bpo=32873

   (357) https://bugs.python.org/issue?@action=redirect&bpo=33134

   (358) https://bugs.python.org/issue?@action=redirect&bpo=33127

   (359) https://bugs.python.org/issue?@action=redirect&bpo=32505

   (360) https://bugs.python.org/issue?@action=redirect&bpo=33078

   (361) https://bugs.python.org/issue?@action=redirect&bpo=33116

   (362) https://bugs.python.org/issue?@action=redirect&bpo=32896

   (363) https://bugs.python.org/issue?@action=redirect&bpo=33100

   (364) https://bugs.python.org/issue?@action=redirect&bpo=32953

   (365) https://bugs.python.org/issue?@action=redirect&bpo=33097

   (366) https://bugs.python.org/issue?@action=redirect&bpo=32968

   (367) https://bugs.python.org/issue?@action=redirect&bpo=33061

   (368) https://bugs.python.org/issue?@action=redirect&bpo=33078

   (369) https://bugs.python.org/issue?@action=redirect&bpo=33064

   (370) https://bugs.python.org/issue?@action=redirect&bpo=33056

   (371) https://bugs.python.org/issue?@action=redirect&bpo=33021

   (372) https://bugs.python.org/issue?@action=redirect&bpo=31804

   (373) https://bugs.python.org/issue?@action=redirect&bpo=33034

   (374) https://bugs.python.org/issue?@action=redirect&bpo=30249

   (375) https://bugs.python.org/issue?@action=redirect&bpo=33037

   (376) https://bugs.python.org/issue?@action=redirect&bpo=27683

   (377) https://bugs.python.org/issue?@action=redirect&bpo=22674

   (378) https://bugs.python.org/issue?@action=redirect&bpo=32999

   (379) https://bugs.python.org/issue?@action=redirect&bpo=33009

   (380) https://bugs.python.org/issue?@action=redirect&bpo=32969

   (381) https://bugs.python.org/issue?@action=redirect&bpo=32056

   (382) https://bugs.python.org/issue?@action=redirect&bpo=32970

   (383) https://bugs.python.org/issue?@action=redirect&bpo=32844

   (384) https://bugs.python.org/issue?@action=redirect&bpo=32960

   (385) https://bugs.python.org/issue?@action=redirect&bpo=32713

   (386) https://bugs.python.org/issue?@action=redirect&bpo=32257

   (387) https://bugs.python.org/issue?@action=redirect&bpo=32951

   (388) https://bugs.python.org/issue?@action=redirect&bpo=32929

   (389) https://bugs.python.org/issue?@action=redirect&bpo=32947

   (390) https://bugs.python.org/issue?@action=redirect&bpo=32146

   (391) https://bugs.python.org/issue?@action=redirect&bpo=30622

   (392) https://bugs.python.org/issue?@action=redirect&bpo=32922

   (393) https://bugs.python.org/issue?@action=redirect&bpo=32759

   (394) https://bugs.python.org/issue?@action=redirect&bpo=32859

   (395) https://bugs.python.org/issue?@action=redirect&bpo=32556

   (396) https://bugs.python.org/issue?@action=redirect&bpo=21060

   (397) https://bugs.python.org/issue?@action=redirect&bpo=32857

   (398) https://bugs.python.org/issue?@action=redirect&bpo=32852

   (399) https://bugs.python.org/issue?@action=redirect&bpo=31333

   (400) https://bugs.python.org/issue?@action=redirect&bpo=32841

   (401) https://bugs.python.org/issue?@action=redirect&bpo=32819

   (402) https://bugs.python.org/issue?@action=redirect&bpo=19675

   (403) https://bugs.python.org/issue?@action=redirect&bpo=32394

   (404) https://bugs.python.org/issue?@action=redirect&bpo=31787

   (405) https://bugs.python.org/issue?@action=redirect&bpo=30157

   (406) https://bugs.python.org/issue?@action=redirect&bpo=30688

   (407) https://bugs.python.org/issue?@action=redirect&bpo=32792

   (408) https://bugs.python.org/issue?@action=redirect&bpo=32775

   (409) https://bugs.python.org/issue?@action=redirect&bpo=32622

   (410) https://bugs.python.org/issue?@action=redirect&bpo=32777

   (411) https://bugs.python.org/issue?@action=redirect&bpo=32647

   (412) https://bugs.python.org/issue?@action=redirect&bpo=32749

   (413) https://bugs.python.org/issue?@action=redirect&bpo=32741

   (414) https://bugs.python.org/issue?@action=redirect&bpo=32691

   (415) https://bugs.python.org/issue?@action=redirect&bpo=32734

   (416) https://bugs.python.org/issue?@action=redirect&bpo=32727

   (417) https://bugs.python.org/issue?@action=redirect&bpo=31453

   (418) https://bugs.python.org/issue?@action=redirect&bpo=24334

   (419) https://bugs.python.org/issue?@action=redirect&bpo=31848

   (420) https://bugs.python.org/issue?@action=redirect&bpo=32585

   (421) https://bugs.python.org/issue?@action=redirect&bpo=32512

   (422) https://bugs.python.org/issue?@action=redirect&bpo=8525

   (423) https://bugs.python.org/issue?@action=redirect&bpo=31639

   (424) https://bugs.python.org/issue?@action=redirect&bpo=29877

   (425) https://bugs.python.org/issue?@action=redirect&bpo=32221

   (426) https://bugs.python.org/issue?@action=redirect&bpo=32147

   (427) https://bugs.python.org/issue?@action=redirect&bpo=30693

   (428) https://bugs.python.org/issue?@action=redirect&bpo=30693

   (429) https://bugs.python.org/issue?@action=redirect&bpo=31680

   (430) https://bugs.python.org/issue?@action=redirect&bpo=31908

   (431) https://bugs.python.org/issue?@action=redirect&bpo=31608

   (432) https://bugs.python.org/issue?@action=redirect&bpo=31425

   (433) https://bugs.python.org/issue?@action=redirect&bpo=22005

   (434) https://bugs.python.org/issue?@action=redirect&bpo=27645

   (435) https://bugs.python.org/issue?@action=redirect&bpo=16865

   (436) https://bugs.python.org/issue?@action=redirect&bpo=31508

   (437) https://bugs.python.org/issue?@action=redirect&bpo=29456


File: python.info,  Node: Documentation<55>,  Next: Tests<54>,  Prev: Library<161>,  Up: Python 3 8 0 alpha 1

1.24.61.4 Documentation
.......................

   - bpo-21257(1): Document *note http.client.parse_headers(): 1e10.

   - bpo-34764(2): Improve example of iter() with 2nd sentinel argument.

   - bpo-35564(3): Explicitly set master_doc variable in conf.py for
     compliance with Sphinx 2.0

   - bpo-35511(4): Specified that profile.Profile class doesn’t not
     support enable or disable methods.  Also, elaborated that Profile
     object as a context manager is only supported in cProfile module.

   - bpo-10536(5): Enhance the gettext docs.  Patch by Éric Araujo

   - bpo-35089(6): Remove mention of ‘typing.io’ and ‘typing.re’.  Their
     types should be imported from ‘typing’ directly.

   - bpo-35038(7): Fix the documentation about an unexisting
     ‘f_restricted’ attribute in the frame object.  Patch by Stéphane
     Wirtel

   - bpo-35042(8): Replace PEP XYZ by the pep role and allow to use the
     direct links to the PEPs.

   - bpo-35044(9): Fix the documentation with the role ‘exc’ for the
     appropriated exception.  Patch by Stéphane Wirtel

   - bpo-35035(10): Rename documentation for *note email.utils: 54. to
     ‘email.utils.rst’.

   - bpo-34967(11): Use app.add_object_type() instead of the deprecated
     Sphinx function app.description_unit()

   - bpo-34913(12): Add documentation about the new command line
     interface of the gzip module.

   - bpo-32174(13): chm document displays non-ASCII characters properly
     on some MBCS Windows systems.

   - bpo-11233(14): Create availability directive for documentation.
     Original patch by Georg Brandl.

   - bpo-34790(15): Document how passing coroutines to asyncio.wait()
     can be confusing.

   - bpo-34552(16): Make clear that ‘==’ operator sometimes is
     equivalent to ‘is’.  The ‘<’, ‘<=’, ‘>’ and ‘>=’ operators are only
     defined where they make sense.

   - bpo-28617(17): Fixed info in the stdtypes docs concerning the types
     that support membership tests.

   - bpo-20177(18): Migrate datetime.date.fromtimestamp to Argument
     Clinic.  Patch by Tim Hoffmann.

   - bpo-34065(19): Fix wrongly written basicConfig documentation markup
     syntax

   - bpo-33460(20): replaced ellipsis with correct error codes in
     tutorial chapter 3.

   - bpo-33847(21): Add “@” operator entry to index.

   - bpo-33409(22): Clarified the relationship between PEP 538(23)’s
     PYTHONCOERCECLOCALE and PEP 540’s PYTHONUTF8 mode.

   - bpo-33197(24): Add versionadded tag to the documentation of
     ParameterKind.description

   - bpo-17045(25): Improve the C-API doc for PyTypeObject.  This
     includes adding several quick-reference tables and a lot of missing
     slot/typedef entries.  The existing entries were also cleaned up
     with a slightly more consistent format.

   - bpo-33736(26): Improve the documentation of *note
     asyncio.open_connection(): d10, *note asyncio.start_server(): d11.
     and their UNIX socket counterparts.

   - bpo-23859(27): Document that ‘asyncio.wait()’ does not cancel its
     futures on timeout.

   - bpo-32436(28): Document PEP 567(29) changes to asyncio.

   - bpo-33604(30): Update HMAC md5 default to a DeprecationWarning,
     bump removal to 3.8.

   - bpo-33594(31): Document ‘getargspec’, ‘from_function’ and
     ‘from_builtin’ as deprecated in their respective docstring, and
     include version since deprecation in DeprecationWarning message.

   - bpo-33503(32): Fix broken pypi link

   - bpo-33421(33): Add missing documentation for
     ‘typing.AsyncContextManager’.

   - bpo-33487(34): BZ2file now emit a DeprecationWarning when
     buffering=None is passed, the deprecation message and documentation
     also now explicitly state it is deprecated since 3.0.

   - bpo-33378(35): Add Korean language switcher for
     ‘https://docs.python.org/3/’

   - bpo-33276(36): Clarify that the ‘__path__’ attribute on modules
     cannot be just any value.

   - bpo-33201(37): Modernize documentation for writing C extension
     types.

   - bpo-33195(38): Deprecate ‘Py_UNICODE’ usage in ‘c-api/arg’
     document.  ‘Py_UNICODE’ related APIs are deprecated since Python
     3.3, but it is missed in the document.

   - bpo-33126(39): Document PyBuffer_ToContiguous().

   - bpo-27212(40): Modify documentation for the ‘islice()’ recipe to
     consume initial values up to the start index.

   - bpo-28247(41): Update *note zipapp: 136. documentation to describe
     how to make standalone applications.

   - bpo-18802(42): Documentation changes for ipaddress.  Patch by Jon
     Foster and Berker Peksag.

   - bpo-27428(43): Update documentation to clarify that
     ‘WindowsRegistryFinder’ implements ‘MetaPathFinder’.  (Patch by
     Himanshu Lakhara)

   - bpo-28124(44): The ssl module function ssl.wrap_socket() has been
     de-emphasized and deprecated in favor of the more secure and
     efficient SSLContext.wrap_socket() method.

   - bpo-17232(45): Clarify docs for -O and -OO. Patch by Terry Reedy.

   - bpo-32436(46): Add documentation for the contextvars module (PEP
     567).

   - bpo-32800(47): Update link to w3c doc for xml default namespaces.

   - bpo-11015(48): Update *note test.support: ea. documentation.

   - bpo-32613(49): Update the faq/windows.html to use the py command
     from PEP 397 instead of python.

   - bpo-8722(50): Document ‘__getattr__()’ behavior when property
     ‘get()’ method raises *note AttributeError: 5f0.

   - bpo-32614(51): Modify RE examples in documentation to use raw
     strings to prevent *note DeprecationWarning: 1a3. and add text to
     REGEX HOWTO to highlight the deprecation.

   - bpo-20709(52): Remove the paragraph where we explain that
     os.utime() does not support a directory as path under Windows.
     Patch by Jan-Philip Gehrcke

   - bpo-32722(53): Remove the bad example in the tutorial of the
     Generator Expression.  Patch by Stéphane Wirtel

   - bpo-31972(54): Improve docstrings for ‘pathlib.PurePath’
     subclasses.

   - bpo-30607(55): Use the externalized ‘python-docs-theme’ package
     when building the documentation.

   - bpo-8243(56): Add a note about curses.addch and curses.addstr
     exception behavior when writing outside a window, or pad.

   - bpo-32337(57): Update documentation related with ‘dict’ order.

   - bpo-25041(58): Document ‘AF_PACKET’ in the *note socket: d1.
     module.

   - bpo-31432(59): Clarify meaning of CERT_NONE, CERT_OPTIONAL, and
     CERT_REQUIRED flags for ssl.SSLContext.verify_mode.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21257

   (2) https://bugs.python.org/issue?@action=redirect&bpo=34764

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35564

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35511

   (5) https://bugs.python.org/issue?@action=redirect&bpo=10536

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35089

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35038

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35042

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35044

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35035

   (11) https://bugs.python.org/issue?@action=redirect&bpo=34967

   (12) https://bugs.python.org/issue?@action=redirect&bpo=34913

   (13) https://bugs.python.org/issue?@action=redirect&bpo=32174

   (14) https://bugs.python.org/issue?@action=redirect&bpo=11233

   (15) https://bugs.python.org/issue?@action=redirect&bpo=34790

   (16) https://bugs.python.org/issue?@action=redirect&bpo=34552

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28617

   (18) https://bugs.python.org/issue?@action=redirect&bpo=20177

   (19) https://bugs.python.org/issue?@action=redirect&bpo=34065

   (20) https://bugs.python.org/issue?@action=redirect&bpo=33460

   (21) https://bugs.python.org/issue?@action=redirect&bpo=33847

   (22) https://bugs.python.org/issue?@action=redirect&bpo=33409

   (23) https://peps.python.org/pep-0538/

   (24) https://bugs.python.org/issue?@action=redirect&bpo=33197

   (25) https://bugs.python.org/issue?@action=redirect&bpo=17045

   (26) https://bugs.python.org/issue?@action=redirect&bpo=33736

   (27) https://bugs.python.org/issue?@action=redirect&bpo=23859

   (28) https://bugs.python.org/issue?@action=redirect&bpo=32436

   (29) https://peps.python.org/pep-0567/

   (30) https://bugs.python.org/issue?@action=redirect&bpo=33604

   (31) https://bugs.python.org/issue?@action=redirect&bpo=33594

   (32) https://bugs.python.org/issue?@action=redirect&bpo=33503

   (33) https://bugs.python.org/issue?@action=redirect&bpo=33421

   (34) https://bugs.python.org/issue?@action=redirect&bpo=33487

   (35) https://bugs.python.org/issue?@action=redirect&bpo=33378

   (36) https://bugs.python.org/issue?@action=redirect&bpo=33276

   (37) https://bugs.python.org/issue?@action=redirect&bpo=33201

   (38) https://bugs.python.org/issue?@action=redirect&bpo=33195

   (39) https://bugs.python.org/issue?@action=redirect&bpo=33126

   (40) https://bugs.python.org/issue?@action=redirect&bpo=27212

   (41) https://bugs.python.org/issue?@action=redirect&bpo=28247

   (42) https://bugs.python.org/issue?@action=redirect&bpo=18802

   (43) https://bugs.python.org/issue?@action=redirect&bpo=27428

   (44) https://bugs.python.org/issue?@action=redirect&bpo=28124

   (45) https://bugs.python.org/issue?@action=redirect&bpo=17232

   (46) https://bugs.python.org/issue?@action=redirect&bpo=32436

   (47) https://bugs.python.org/issue?@action=redirect&bpo=32800

   (48) https://bugs.python.org/issue?@action=redirect&bpo=11015

   (49) https://bugs.python.org/issue?@action=redirect&bpo=32613

   (50) https://bugs.python.org/issue?@action=redirect&bpo=8722

   (51) https://bugs.python.org/issue?@action=redirect&bpo=32614

   (52) https://bugs.python.org/issue?@action=redirect&bpo=20709

   (53) https://bugs.python.org/issue?@action=redirect&bpo=32722

   (54) https://bugs.python.org/issue?@action=redirect&bpo=31972

   (55) https://bugs.python.org/issue?@action=redirect&bpo=30607

   (56) https://bugs.python.org/issue?@action=redirect&bpo=8243

   (57) https://bugs.python.org/issue?@action=redirect&bpo=32337

   (58) https://bugs.python.org/issue?@action=redirect&bpo=25041

   (59) https://bugs.python.org/issue?@action=redirect&bpo=31432


File: python.info,  Node: Tests<54>,  Next: Build<61>,  Prev: Documentation<55>,  Up: Python 3 8 0 alpha 1

1.24.61.5 Tests
...............

   - bpo-35772(1): Fix sparse file tests of test_tarfile on ppc64 with
     the tmpfs filesystem.  Fix the function testing if the filesystem
     supports sparse files: create a file which contains data and
     «holes», instead of creating a file which contains no data.  tmpfs
     effective block size is a page size (tmpfs lives in the page
     cache).  RHEL uses 64 KiB pages on aarch64, ppc64, ppc64le, only
     s390x and x86_64 use 4 KiB pages, whereas the test punch holes of 4
     KiB.

   - bpo-35045(2): Make ssl tests less strict and also accept TLSv1 as
     system default.  The changes unbreaks test_min_max_version on
     Fedora 29.

   - bpo-32710(3): ‘test_asyncio/test_sendfile.py’ now resets the event
     loop policy using ‘tearDownModule()’ as done in other tests, to
     prevent a warning when running tests on Windows.

   - bpo-33717(4): test.pythoninfo now logs information of all clocks,
     not only time.time() and time.perf_counter().

   - bpo-35488(5): Add a test to pathlib’s Path.match() to verify it
     does not support glob-style ** recursive pattern matching.

   - bpo-31731(6): Fix a race condition in ‘check_interrupted_write()’
     of test_io: create directly the thread with SIGALRM signal blocked,
     rather than blocking the signal later from the thread.  Previously,
     it was possible that the thread gets the signal before the signal
     is blocked.

   - bpo-35424(7): Fix test_multiprocessing_main_handling: use
     ‘multiprocessing.Pool’ with a context manager and then explicitly
     join the pool.

   - bpo-35519(8): Rename ‘test.bisect’ module to ‘test.bisect_cmd’ to
     avoid conflict with *note bisect: 12. module when running directly
     a test like ‘./python Lib/test/test_xmlrpc.py’.

   - bpo-35513(9): Replace *note time.time(): 55d. with *note
     time.monotonic(): 55c. in tests to measure time delta.

   - bpo-34279(10): ‘test.support.run_unittest()’ no longer raise
     ‘TestDidNotRun’ if the test result contains skipped tests.  The
     exception is now only raised if no test have been run and no test
     have been skipped.

   - bpo-35412(11): Add testcase to ‘test_future4’: check unicode
     literal.

   - bpo-26704(12): Added test demonstrating double-patching of an
     instance method.  Patch by Anthony Sottile.

   - bpo-33725(13): test_multiprocessing_fork may crash on recent
     versions of macOS. Until the issue is resolved, skip the test on
     macOS.

   - bpo-35352(14): Modify test_asyncio to use the certificate set from
     the test directory.

   - bpo-35317(15): Fix ‘mktime()’ overflow error in ‘test_email’: run
     ‘test_localtime_daylight_true_dst_true()’ and
     ‘test_localtime_daylight_false_dst_true()’ with a specific
     timezone.

   - bpo-21263(16): After several reports that test_gdb does not work
     properly on macOS and since gdb is not shipped by default anymore,
     test_gdb is now skipped on macOS when LLVM Clang has been used to
     compile Python.  Patch by Lysandros Nikolaou

   - bpo-34279(17): regrtest issue a warning when no tests have been
     executed in a particular test file.  Also, a new final result state
     is issued if no test have been executed across all test files.
     Patch by Pablo Galindo.

   - bpo-34962(18): make docstest in Doc now passes., and is enforced in
     CI

   - bpo-23596(19): Use argparse for the command line of the gzip
     module.  Patch by Antony Lee

   - bpo-34537(20): Fix ‘test_gdb.test_strings()’ when ‘LC_ALL=C’ and
     GDB was compiled with Python 3.6 or earlier.

   - bpo-34587(21): test_socket: Remove RDSTest.testCongestion().  The
     test tries to fill the receiver’s socket buffer and expects an
     error.  But the RDS protocol doesn’t require that.  Moreover, the
     Linux implementation of RDS expects that the producer of the
     messages reduces its rate, it’s not the role of the receiver to
     trigger an error.  The test fails on Fedora 28 by design, so just
     remove it.

   - bpo-34661(22): Fix test_shutil if unzip doesn’t support -t.

   - bpo-34200(23): Fixed non-deterministic flakiness of test_pkg by not
     using the scary test.support.module_cleanup() logic to save and
     restore sys.modules contents between test cases.

   - bpo-34569(24): The experimental PEP 554 data channels now correctly
     pass negative PyLong objects between subinterpreters on 32-bit
     systems.  Patch by Michael Felt.

   - bpo-34594(25): Fix usage of hardcoded ‘errno’ values in the tests.

   - bpo-34579(26): Fix test_embed for AIX Patch by Michael Felt

   - bpo-34542(27): Use 3072 RSA keys and SHA-256 signature for test
     certs and keys.

   - bpo-11193(28): Remove special condition for AIX in
     ‘test_subprocess.test_undecodable_env’

   - bpo-34347(29): Fix ‘test_utf8_mode.test_cmd_line’ for AIX

   - bpo-34490(30): On AIX with AF_UNIX family sockets getsockname()
     does not provide “sockname”, so skip calls to
     transport.get_extra_info(“sockname”)

   - bpo-34391(31): Fix ftplib test for TLS 1.3 by reading from data
     socket.

   - bpo-11192(32): Fix ‘test_socket’ on AIX 6.1 and later IPv6 zone id
     supports only supported by ‘inet_pton6_zone()’.  Switch to
     runtime-based ‘platform.system()’ to establish current platform
     rather than build-time based ‘sys.platform()’

   - bpo-34399(33): Update all RSA keys and DH params to use at least
     2048 bits.

   - bpo-34373(34): Fix ‘test_mktime’ and ‘test_pthread_getcpuclickid’
     tests for AIX Add range checking for ‘_PyTime_localtime’ for AIX
     Patch by Michael Felt

   - bpo-11191(35): Skip the distutils test “test_search_cpp” when using
     XLC as compiler patch by aixtools (Michael Felt)

   - Improved an error message when mock assert_has_calls fails.

   - bpo-33746(36): Fix test_unittest when run in verbose mode.

   - bpo-33901(37): Fix test_dbm_gnu on macOS with gdbm 1.15: add a
     larger value to make sure that the file size changes.

   - bpo-33873(38): Fix a bug in ‘regrtest’ that caused an extra test to
     run if –huntrleaks/-R was used.  Exit with error in case that
     invalid parameters are specified to –huntrleaks/-R (at least one
     warmup run and one repetition must be used).

   - bpo-33562(39): Check that a global asyncio event loop policy is not
     left behind by any tests.

   - bpo-33655(40): Ignore test_posix_fallocate failures on BSD
     platforms that might be due to running on ZFS.

   - bpo-32962(41): Fixed test_gdb when Python is compiled with flags
     -mcet -fcf-protection -O0.

   - bpo-33358(42): Fix
     ‘test_embed.test_pre_initialization_sys_options()’ when the
     interpreter is built with ‘--enable-shared’.

   - bpo-32872(43): Avoid regrtest compatibility issue with namespace
     packages.

   - bpo-32517(44): Fix failing ‘test_asyncio’ on macOS 10.12.2+ due to
     transport of ‘KqueueSelector’ loop was not being closed.

   - bpo-32663(45): Making sure the ‘SMTPUTF8SimTests’ class of tests
     gets run in ‘test_smtplib.py’.

   - bpo-27643(46): Test_C test case needs «signed short» bitfields, but
     the IBM XLC compiler (on AIX) does not support this Skip the code
     and test when AIX and XLC are used

     Applicable to Python2-2.7 and later

   - bpo-19417(47): Add test_bdb.py.

   - bpo-31809(48): Add tests to verify connection with secp ECDH
     curves.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35772

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35045

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32710

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33717

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35488

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31731

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35424

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35519

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35513

   (10) https://bugs.python.org/issue?@action=redirect&bpo=34279

   (11) https://bugs.python.org/issue?@action=redirect&bpo=35412

   (12) https://bugs.python.org/issue?@action=redirect&bpo=26704

   (13) https://bugs.python.org/issue?@action=redirect&bpo=33725

   (14) https://bugs.python.org/issue?@action=redirect&bpo=35352

   (15) https://bugs.python.org/issue?@action=redirect&bpo=35317

   (16) https://bugs.python.org/issue?@action=redirect&bpo=21263

   (17) https://bugs.python.org/issue?@action=redirect&bpo=34279

   (18) https://bugs.python.org/issue?@action=redirect&bpo=34962

   (19) https://bugs.python.org/issue?@action=redirect&bpo=23596

   (20) https://bugs.python.org/issue?@action=redirect&bpo=34537

   (21) https://bugs.python.org/issue?@action=redirect&bpo=34587

   (22) https://bugs.python.org/issue?@action=redirect&bpo=34661

   (23) https://bugs.python.org/issue?@action=redirect&bpo=34200

   (24) https://bugs.python.org/issue?@action=redirect&bpo=34569

   (25) https://bugs.python.org/issue?@action=redirect&bpo=34594

   (26) https://bugs.python.org/issue?@action=redirect&bpo=34579

   (27) https://bugs.python.org/issue?@action=redirect&bpo=34542

   (28) https://bugs.python.org/issue?@action=redirect&bpo=11193

   (29) https://bugs.python.org/issue?@action=redirect&bpo=34347

   (30) https://bugs.python.org/issue?@action=redirect&bpo=34490

   (31) https://bugs.python.org/issue?@action=redirect&bpo=34391

   (32) https://bugs.python.org/issue?@action=redirect&bpo=11192

   (33) https://bugs.python.org/issue?@action=redirect&bpo=34399

   (34) https://bugs.python.org/issue?@action=redirect&bpo=34373

   (35) https://bugs.python.org/issue?@action=redirect&bpo=11191

   (36) https://bugs.python.org/issue?@action=redirect&bpo=33746

   (37) https://bugs.python.org/issue?@action=redirect&bpo=33901

   (38) https://bugs.python.org/issue?@action=redirect&bpo=33873

   (39) https://bugs.python.org/issue?@action=redirect&bpo=33562

   (40) https://bugs.python.org/issue?@action=redirect&bpo=33655

   (41) https://bugs.python.org/issue?@action=redirect&bpo=32962

   (42) https://bugs.python.org/issue?@action=redirect&bpo=33358

   (43) https://bugs.python.org/issue?@action=redirect&bpo=32872

   (44) https://bugs.python.org/issue?@action=redirect&bpo=32517

   (45) https://bugs.python.org/issue?@action=redirect&bpo=32663

   (46) https://bugs.python.org/issue?@action=redirect&bpo=27643

   (47) https://bugs.python.org/issue?@action=redirect&bpo=19417

   (48) https://bugs.python.org/issue?@action=redirect&bpo=31809


File: python.info,  Node: Build<61>,  Next: Windows<54>,  Prev: Tests<54>,  Up: Python 3 8 0 alpha 1

1.24.61.6 Build
...............

   - bpo-34691(1): The _contextvars module is now built into the core
     Python library on Windows.

   - bpo-35683(2): Improved Azure Pipelines build steps and now
     verifying layouts correctly

   - bpo-35642(3): Remove asynciomodule.c from pythoncore.vcxproj

   - bpo-35550(4): Fix incorrect Solaris #ifdef checks to look for __sun
     && __SVR4 instead of sun when compiling.

   - bpo-35499(5): ‘make profile-opt’ no longer replaces ‘CFLAGS_NODIST’
     with ‘CFLAGS’.  It now adds profile-guided optimization (PGO) flags
     to ‘CFLAGS_NODIST’: existing ‘CFLAGS_NODIST’ flags are kept.

   - bpo-35257(6): Avoid leaking the linker flags from Link Time
     Optimizations (LTO) into distutils when compiling C extensions.

   - bpo-35351(7): When building Python with clang and LTO, LTO flags
     are no longer passed into CFLAGS to build third-party C extensions
     through distutils.

   - bpo-35139(8): Fix a compiler error when statically linking
     ‘pyexpat’ in ‘Modules/Setup’.

   - bpo-35059(9): PCbuild: Set InlineFunctionExpansion to
     OnlyExplicitInline («/Ob1» option) in pyproject.props in Debug mode
     to expand functions marked as inline.  This change should make
     Python compiled in Debug mode a little bit faster on Windows.

   - bpo-35011(10): Restores the use of pyexpatns.h to isolate our
     embedded copy of the expat C library so that its symbols do not
     conflict at link or dynamic loading time with an embedding
     application or other extension modules with their own version of
     libexpat.

   - bpo-28015(11): Have –with-lto works correctly with clang.

   - bpo-34765(12): Update the outdated install-sh file to the latest
     revision from automake v1.16.1

   - bpo-34585(13): Check for floating-point byte order in configure.ac
     using compilation tests instead of executing code, so that these
     checks work in cross-compiled builds.

   - bpo-34710(14): Fixed SSL module build with OpenSSL & pedantic
     CFLAGS.

   - bpo-34582(15): Add JUnit XML output for regression tests and update
     Azure DevOps builds.

   - bpo-34081(16): Make Sphinx warnings as errors in the Docs Makefile.

   - bpo-34555(17): Fix for case where it was not possible to have both
     ‘HAVE_LINUX_VM_SOCKETS_H’ and ‘HAVE_SOCKADDR_ALG’ be undefined.

   - bpo-33015(18): Fix an undefined behaviour in the pthread
     implementation of *note PyThread_start_new_thread(): 1e13.: add a
     function wrapper to always return ‘NULL’.

   - bpo-34245(19): The Python shared library is now installed with
     write permission (mode 0755), which is the standard way of
     installing such libraries.

   - bpo-34121(20): Fix detection of C11 atomic support on clang.

   - bpo-32430(21): Rename Modules/Setup.dist to Modules/Setup, and
     remove the necessity to copy the former manually to the latter when
     updating the local source tree.

   - bpo-30345(22): Add -g to LDFLAGS when compiling with LTO to get
     debug symbols.

   - bpo-5755(23): Move ‘-Wstrict-prototypes’ option to ‘CFLAGS_NODIST’
     from ‘OPT’.  This option emitted annoying warnings when building
     extension modules written in C++.

   - bpo-33614(24): Ensures module definition files for the stable ABI
     on Windows are correctly regenerated.

   - bpo-33648(25): The –with-c-locale-warning configuration flag has
     been removed.  It has had no effect for about a year.

   - bpo-33522(26): Enable CI builds on Visual Studio Team Services at
     ‘https://python.visualstudio.com/cpython’

   - bpo-33512(27): configure’s check for «long double» has been
     simplified

   - bpo-33483(28): C compiler is now correctly detected from the
     standard environment variables.  –without-gcc and –with-icc options
     have been removed.

   - bpo-33394(29): Enable the verbose build for extension modules, when
     GNU make is passed macros on the command line.

   - bpo-33393(30): Update config.guess and config.sub files.

   - bpo-33377(31): Add new triplets for mips r6 and riscv variants
     (used in extension suffixes).

   - bpo-32232(32): By default, modules configured in ‘Modules/Setup’
     are no longer built with ‘-DPy_BUILD_CORE’.  Instead, modules that
     specifically need that preprocessor definition include it in their
     individual entries.

   - bpo-33182(33): The embedding tests can once again be built with
     clang 6.0

   - bpo-33163(34): Upgrade pip to 9.0.3 and setuptools to v39.0.1.

   - bpo-33012(35): gcc 8 has added a new warning heuristic to detect
     invalid function casts and a stock python build seems to hit that
     warning quite often.  The most common is the cast of a METH_NOARGS
     function (that uses just one argument) to a PyCFunction.  Fix this
     by adding a dummy argument to all functions that implement
     METH_NOARGS.

   - bpo-32898(36): Fix the python debug build when using COUNT_ALLOCS.

   - bpo-29442(37): Replace optparse with argparse in setup.py

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34691

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35683

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35642

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35550

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35499

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35257

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35351

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35139

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35059

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35011

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28015

   (12) https://bugs.python.org/issue?@action=redirect&bpo=34765

   (13) https://bugs.python.org/issue?@action=redirect&bpo=34585

   (14) https://bugs.python.org/issue?@action=redirect&bpo=34710

   (15) https://bugs.python.org/issue?@action=redirect&bpo=34582

   (16) https://bugs.python.org/issue?@action=redirect&bpo=34081

   (17) https://bugs.python.org/issue?@action=redirect&bpo=34555

   (18) https://bugs.python.org/issue?@action=redirect&bpo=33015

   (19) https://bugs.python.org/issue?@action=redirect&bpo=34245

   (20) https://bugs.python.org/issue?@action=redirect&bpo=34121

   (21) https://bugs.python.org/issue?@action=redirect&bpo=32430

   (22) https://bugs.python.org/issue?@action=redirect&bpo=30345

   (23) https://bugs.python.org/issue?@action=redirect&bpo=5755

   (24) https://bugs.python.org/issue?@action=redirect&bpo=33614

   (25) https://bugs.python.org/issue?@action=redirect&bpo=33648

   (26) https://bugs.python.org/issue?@action=redirect&bpo=33522

   (27) https://bugs.python.org/issue?@action=redirect&bpo=33512

   (28) https://bugs.python.org/issue?@action=redirect&bpo=33483

   (29) https://bugs.python.org/issue?@action=redirect&bpo=33394

   (30) https://bugs.python.org/issue?@action=redirect&bpo=33393

   (31) https://bugs.python.org/issue?@action=redirect&bpo=33377

   (32) https://bugs.python.org/issue?@action=redirect&bpo=32232

   (33) https://bugs.python.org/issue?@action=redirect&bpo=33182

   (34) https://bugs.python.org/issue?@action=redirect&bpo=33163

   (35) https://bugs.python.org/issue?@action=redirect&bpo=33012

   (36) https://bugs.python.org/issue?@action=redirect&bpo=32898

   (37) https://bugs.python.org/issue?@action=redirect&bpo=29442


File: python.info,  Node: Windows<54>,  Next: macOS<41>,  Prev: Build<61>,  Up: Python 3 8 0 alpha 1

1.24.61.7 Windows
.................

   - bpo-35890(1): Fix API calling consistency of GetVersionEx and
     wcstok.

   - bpo-32560(2): The ‘py’ launcher now forwards its ‘STARTUPINFO’
     structure to child processes.

   - bpo-35854(3): Fix EnvBuilder and –symlinks in venv on Windows

   - bpo-35811(4): Avoid propagating venv settings when launching via
     py.exe

   - bpo-35797(5): Fix default executable used by the multiprocessing
     module

   - bpo-35758(6): Allow building on ARM with MSVC.

   - bpo-29734(7): Fix handle leaks in os.stat on Windows.

   - bpo-35596(8): Use unchecked PYCs for the embeddable distro to avoid
     zipimport restrictions.

   - bpo-35596(9): Fix vcruntime140.dll being added to embeddable distro
     multiple times.

   - bpo-35402(10): Update Windows build to use Tcl and Tk 8.6.9

   - bpo-35401(11): Updates Windows build to OpenSSL 1.1.0j

   - bpo-34977(12): venv on Windows will now use a python.exe redirector
     rather than copying the actual binaries from the base environment.

   - bpo-34977(13): Adds support for building a Windows App Store
     package

   - bpo-35067(14): Remove _distutils_findvs module and use vswhere.exe
     instead.

   - bpo-32557(15): Allow shutil.disk_usage to take a file path on
     Windows

   - bpo-34770(16): Fix a possible null pointer dereference in
     pyshellext.cpp.

   - bpo-34603(17): Fix returning structs from functions produced by
     MSVC

   - bpo-34581(18): Guard MSVC-specific code in socketmodule.c with
     ‘#ifdef _MSC_VER’.

   - bpo-34532(19): Fixes exit code of list version arguments for
     py.exe.

   - bpo-34062(20): Fixed the “–list” and “–list-paths” arguments for
     the py.exe launcher

   - bpo-34225(21): Ensure INCLUDE and LIB directories do not end with a
     backslash.

   - bpo-34011(22): A suite of code has been changed which copied across
     DLLs and init.tcl from the running Python location into a venv
     being created.  These copies are needed only when running from a
     Python source build, and the copying code is now only run when that
     is the case, rather than whenever a venv is created.

   - bpo-34006(23): Revert line length limit for Windows help docs.  The
     line-length limit is not needed because the pages appear in a
     separate app rather than on a browser tab.  It can also interact
     badly with the DPI setting.

   - bpo-31546(24): Restore running PyOS_InputHook while waiting for
     user input at the prompt.  The restores integration of interactive
     GUI windows (such as Matplotlib figures) with the prompt on
     Windows.

   - bpo-30237(25): Output error when ReadConsole is canceled by
     CancelSynchronousIo instead of crashing.

   - bpo-33895(26): GIL is released while calling functions that acquire
     Windows loader lock.

   - bpo-33720(27): Reduces maximum marshal recursion depth on release
     builds.

   - bpo-29097(28): Fix bug where ‘datetime.fromtimestamp()’ erroneously
     throws an *note OSError: 2c0. on Windows for values between 0 and
     86400.  Patch by Ammar Askar.

   - bpo-33316(29): PyThread_release_lock always fails

   - bpo-33184(30): Update Windows installer to use OpenSSL 1.1.0h.

   - bpo-32890(31): Fix usage of GetLastError() instead of errno in
     os.execve() and os.truncate().

   - bpo-33016(32): Fix potential use of uninitialized memory in
     nt._getfinalpathname

   - bpo-32903(33): Fix a memory leak in os.chdir() on Windows if the
     current directory is set to a UNC path.

   - bpo-32901(34): Update Tcl and Tk versions to 8.6.8

   - bpo-31966(35): Fixed WindowsConsoleIO.write() for writing empty
     data.

   - bpo-32409(36): Ensures activate.bat can handle Unicode contents.

   - bpo-32457(37): Improves handling of denormalized executable path
     when launching Python.

   - bpo-32370(38): Use the correct encoding for ipconfig output in the
     uuid module.  Patch by Segev Finer.

   - bpo-29248(39): Fix *note os.readlink(): b1c. on Windows, which was
     mistakenly treating the ‘PrintNameOffset’ field of the reparse data
     buffer as a number of characters instead of bytes.  Patch by Craig
     Holmquist and SSE4.

   - bpo-1104(40): Correctly handle string length in
     ‘msilib.SummaryInfo.GetProperty()’ to prevent it from truncating
     the last character.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35890

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32560

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35854

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35811

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35797

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35758

   (7) https://bugs.python.org/issue?@action=redirect&bpo=29734

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35596

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35596

   (10) https://bugs.python.org/issue?@action=redirect&bpo=35402

   (11) https://bugs.python.org/issue?@action=redirect&bpo=35401

   (12) https://bugs.python.org/issue?@action=redirect&bpo=34977

   (13) https://bugs.python.org/issue?@action=redirect&bpo=34977

   (14) https://bugs.python.org/issue?@action=redirect&bpo=35067

   (15) https://bugs.python.org/issue?@action=redirect&bpo=32557

   (16) https://bugs.python.org/issue?@action=redirect&bpo=34770

   (17) https://bugs.python.org/issue?@action=redirect&bpo=34603

   (18) https://bugs.python.org/issue?@action=redirect&bpo=34581

   (19) https://bugs.python.org/issue?@action=redirect&bpo=34532

   (20) https://bugs.python.org/issue?@action=redirect&bpo=34062

   (21) https://bugs.python.org/issue?@action=redirect&bpo=34225

   (22) https://bugs.python.org/issue?@action=redirect&bpo=34011

   (23) https://bugs.python.org/issue?@action=redirect&bpo=34006

   (24) https://bugs.python.org/issue?@action=redirect&bpo=31546

   (25) https://bugs.python.org/issue?@action=redirect&bpo=30237

   (26) https://bugs.python.org/issue?@action=redirect&bpo=33895

   (27) https://bugs.python.org/issue?@action=redirect&bpo=33720

   (28) https://bugs.python.org/issue?@action=redirect&bpo=29097

   (29) https://bugs.python.org/issue?@action=redirect&bpo=33316

   (30) https://bugs.python.org/issue?@action=redirect&bpo=33184

   (31) https://bugs.python.org/issue?@action=redirect&bpo=32890

   (32) https://bugs.python.org/issue?@action=redirect&bpo=33016

   (33) https://bugs.python.org/issue?@action=redirect&bpo=32903

   (34) https://bugs.python.org/issue?@action=redirect&bpo=32901

   (35) https://bugs.python.org/issue?@action=redirect&bpo=31966

   (36) https://bugs.python.org/issue?@action=redirect&bpo=32409

   (37) https://bugs.python.org/issue?@action=redirect&bpo=32457

   (38) https://bugs.python.org/issue?@action=redirect&bpo=32370

   (39) https://bugs.python.org/issue?@action=redirect&bpo=29248

   (40) https://bugs.python.org/issue?@action=redirect&bpo=1104


File: python.info,  Node: macOS<41>,  Next: IDLE<37>,  Prev: Windows<54>,  Up: Python 3 8 0 alpha 1

1.24.61.8 macOS
...............

   - bpo-35401(1): Update macOS installer to use OpenSSL 1.1.0j.

   - bpo-35025(2): Properly guard the use of the ‘CLOCK_GETTIME’ et al.
     macros in ‘timemodule’ on macOS.

   - bpo-24658(3): On macOS, fix reading from and writing into a file
     with a size larger than 2 GiB.

   - bpo-34405(4): Update to OpenSSL 1.1.0i for macOS installer builds.

   - bpo-33635(5): In macOS stat on some file descriptors (/dev/fd/3
     f.e) will result in bad file descriptor OSError.  Guard against
     this exception was added in is_dir, is_file and similar methods.
     DirEntry.is_dir can also throw this exception so
     _RecursiveWildcardSelector._iterate_directories was also extended
     with the same error ignoring pattern.

   - bpo-13631(6): The .editrc file in user’s home directory is now
     processed correctly during the readline initialization through
     editline emulation on macOS.

   - bpo-33184(7): Update macOS installer build to use OpenSSL 1.1.0h.

   - bpo-32726(8): Build and link with private copy of Tcl/Tk 8.6 for
     the macOS 10.6+ installer.  The 10.9+ installer variant already
     does this.  This means that the Python 3.7 provided by the
     python.org macOS installers no longer need or use any external
     versions of Tcl/Tk, either system-provided or user-installed, such
     as ActiveTcl.

   - bpo-32901(9): Update macOS 10.9+ installer to Tcl/Tk 8.6.8.

   - bpo-31903(10): In ‘_scproxy’, drop the GIL when calling into
     ‘SystemConfiguration’ to avoid deadlocks.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35401

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35025

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24658

   (4) https://bugs.python.org/issue?@action=redirect&bpo=34405

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33635

   (6) https://bugs.python.org/issue?@action=redirect&bpo=13631

   (7) https://bugs.python.org/issue?@action=redirect&bpo=33184

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32726

   (9) https://bugs.python.org/issue?@action=redirect&bpo=32901

   (10) https://bugs.python.org/issue?@action=redirect&bpo=31903


File: python.info,  Node: IDLE<37>,  Next: Tools/Demos<37>,  Prev: macOS<41>,  Up: Python 3 8 0 alpha 1

1.24.61.9 IDLE
..............

   - bpo-35770(1): IDLE macosx deletes Options => Configure IDLE. It
     previously deleted Window => Zoom Height by mistake.  (Zoom Height
     is now on the Options menu).  On Mac, the settings dialog is
     accessed via Preferences on the IDLE menu.

   - bpo-35769(2): Change IDLE’s new file name from “Untitled” to
     “untitled”

   - bpo-35660(3): Fix imports in idlelib.window.

   - bpo-35641(4): Proper format ‘calltip’ when the function has no
     docstring.

   - bpo-33987(5): Use ttk Frame for ttk widgets.

   - bpo-34055(6): Fix erroneous “smart” indents and newlines in IDLE
     Shell.

   - bpo-35591(7): Find Selection now works when selection not found.

   - bpo-35196(8): Speed up squeezer line counting.

   - bpo-35598(9): Update config_key: use PEP 8 names and ttk widgets,
     make some objects global, and add tests.

   - bpo-28097(10): Add Previous/Next History entries to Shell menu.

   - bpo-35208(11): Squeezer now properly counts wrapped lines before
     newlines.

   - bpo-35555(12): Gray out Code Context menu entry when it’s not
     applicable.

   - bpo-35521(13): Document the IDLE editor code context feature.  Add
     some internal references within the IDLE doc.

   - bpo-22703(14): The Code Context menu label now toggles between
     Show/Hide Code Context.  The Zoom Height menu now toggles between
     Zoom/Restore Height.  Zoom Height has moved from the Window menu to
     the Options menu.

   - bpo-35213(15): Where appropriate, use “macOS” in idlelib.

   - bpo-34864(16): On macOS, warn if the system preference «Prefer tabs
     when opening documents» is set to «Always».

   - bpo-34864(17): Document two IDLE on MacOS issues.  The System
     Preferences Dock «prefer tabs always» setting disables some IDLE
     features.  Menus are a bit different than as described for Windows
     and Linux.

   - bpo-35202(18): Remove unused imports from lib/idlelib

   - bpo-33000(19): Document that IDLE’s shell has no line limit.  A
     program that runs indefinitely can overfill memory.

   - bpo-23220(20): Explain how IDLE’s Shell displays output.

   - bpo-35099(21): Improve the doc about IDLE running user code.  The
     section is renamed from «IDLE – console differences» is renamed
     «Running user code».  It mostly covers the implications of using
     custom ‘sys.stdXXX’ objects.

   - bpo-35097(22): Add IDLE doc subsection explaining editor windows.
     Topics include opening, title and status bar, .py* extension, and
     running.

   - bpo-35093(23): Document the IDLE document viewer in the IDLE doc.
     Add a paragraph in «Help and preferences», «Help sources»
     subsection.

   - bpo-35088(24): Update idlelib.help.copy_string docstring.  We now
     use git and backporting instead of hg and forward merging.

   - bpo-35087(25): Update idlelib help files for the current doc build.
     The main change is the elimination of chapter-section numbers.

   - bpo-34548(26): Use configured color theme for read-only text views.

   - bpo-1529353(27): Enable «squeezing» of long outputs in the shell,
     to avoid performance degradation and to clean up the history
     without losing it.  Squeezed outputs may be copied, viewed in a
     separate window, and «unsqueezed».

   - bpo-34047(28): Fixed mousewheel scrolling direction on macOS.

   - bpo-34275(29): Make IDLE calltips always visible on Mac.  Some
     MacOS-tk combinations need .update_idletasks().  Patch by Kevin
     Walzer.

   - bpo-34120(30): Fix unresponsiveness after closing certain windows
     and dialogs.

   - bpo-33975(31): Avoid small type when running htests.  Since part of
     the purpose of human-viewed tests is to determine that widgets look
     right, it is important that they look the same for testing as when
     running IDLE.

   - bpo-33905(32): Add test for idlelib.stackview.StackBrowser.

   - bpo-33924(33): Change mainmenu.menudefs key “windows” to “window”.
     Every other menudef key is lowercase version of main menu entry.

   - bpo-33906(34): Rename idlelib.windows as window Match Window on the
     main menu and remove last plural module name.

   - bpo-33917(35): Fix and document idlelib/idle_test/template.py.  The
     revised file compiles, runs, and tests OK. idle_test/README.txt
     explains how to use it to create new IDLE test files.

   - bpo-33904(36): IDLE: In rstrip, rename class RstripExtension as
     Rstrip

   - bpo-33907(37): For consistency and clarity, rename an IDLE module
     and classes.  Module calltips and its class CallTips are now
     calltip and Calltip.  In module calltip_w, class CallTip is now
     CalltipWindow.

   - bpo-33856(38): Add «help» in the welcome message of IDLE

   - bpo-33839(39): IDLE: refactor ToolTip and CallTip and add
     documentation and tests

   - bpo-33855(40): Minimally test all IDLE modules.  Add missing files,
     import module, instantiate classes, and check coverage.  Check
     existing files.

   - bpo-33656(41): On Windows, add API call saying that tk scales for
     DPI. On Windows 8.1+ or 10, with DPI compatibility properties of
     the Python binary unchanged, and a monitor resolution greater than
     96 DPI, this should make text and lines sharper.  It should
     otherwise have no effect.

   - bpo-33768(42): Clicking on a context line moves that line to the
     top of the editor window.

   - bpo-33763(43): IDLE: Use read-only text widget for code context
     instead of label widget.

   - bpo-33664(44): Scroll IDLE editor text by lines.  Previously, the
     mouse wheel and scrollbar slider moved text by a fixed number of
     pixels, resulting in partial lines at the top of the editor box.
     The change also applies to the shell and grep output windows, but
     not to read-only text views.

   - bpo-33679(45): Enable theme-specific color configuration for Code
     Context.  Use the Highlights tab to see the setting for built-in
     themes or add settings to custom themes.

   - bpo-33642(46): Display up to maxlines non-blank lines for Code
     Context.  If there is no current context, show a single blank line.

   - bpo-33628(47): IDLE: Cleanup codecontext.py and its test.

   - bpo-33564(48): IDLE’s code context now recognizes async as a block
     opener.

   - bpo-21474(49): Update word/identifier definition from ascii to
     unicode.  In text and entry boxes, this affects selection by
     double-click, movement left/right by control-left/right, and
     deletion left/right by control-BACKSPACE/DEL.

   - bpo-33204(50): IDLE: consistently color invalid string prefixes.  A
     “u” string prefix cannot be paired with either “r” or “f”.
     Consistently color as much of the prefix, starting at the right, as
     is valid.  Revise and extend colorizer test.

   - bpo-32984(51): Set ‘__file__’ while running a startup file.  Like
     Python, IDLE optionally runs one startup file in the Shell window
     before presenting the first interactive input prompt.  For IDLE,
     ‘-s’ runs a file named in environmental variable ‘IDLESTARTUP’ or
     *note PYTHONSTARTUP: 1b8.; ‘-r file’ runs ‘file’.  Python sets
     ‘__file__’ to the startup file name before running the file and
     unsets it before the first prompt.  IDLE now does the same when run
     normally, without the ‘-n’ option.

   - bpo-32940(52): Simplify and rename StringTranslatePseudoMapping in
     pyparse.

   - bpo-32916(53): Change ‘str’ to ‘code’ in pyparse.

   - bpo-32905(54): Remove unused code in pyparse module.

   - bpo-32874(55): Add tests for pyparse.

   - bpo-32837(56): Using the system and place-dependent default
     encoding for open() is a bad idea for IDLE’s system and
     location-independent files.

   - bpo-32826(57): Add «encoding=utf-8» to open() in IDLE’s
     test_help_about.  GUI test test_file_buttons() only looks at
     initial ascii-only lines, but failed on systems where open()
     defaults to “ascii” because readline() internally reads and decodes
     far enough ahead to encounter a non-ascii character in CREDITS.txt.

   - bpo-32831(58): Add docstrings and tests for codecontext.

   - bpo-32765(59): Update configdialog General tab docstring to add new
     widgets to the widget list.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35770

   (2) https://bugs.python.org/issue?@action=redirect&bpo=35769

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35660

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35641

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33987

   (6) https://bugs.python.org/issue?@action=redirect&bpo=34055

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35591

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35196

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35598

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28097

   (11) https://bugs.python.org/issue?@action=redirect&bpo=35208

   (12) https://bugs.python.org/issue?@action=redirect&bpo=35555

   (13) https://bugs.python.org/issue?@action=redirect&bpo=35521

   (14) https://bugs.python.org/issue?@action=redirect&bpo=22703

   (15) https://bugs.python.org/issue?@action=redirect&bpo=35213

   (16) https://bugs.python.org/issue?@action=redirect&bpo=34864

   (17) https://bugs.python.org/issue?@action=redirect&bpo=34864

   (18) https://bugs.python.org/issue?@action=redirect&bpo=35202

   (19) https://bugs.python.org/issue?@action=redirect&bpo=33000

   (20) https://bugs.python.org/issue?@action=redirect&bpo=23220

   (21) https://bugs.python.org/issue?@action=redirect&bpo=35099

   (22) https://bugs.python.org/issue?@action=redirect&bpo=35097

   (23) https://bugs.python.org/issue?@action=redirect&bpo=35093

   (24) https://bugs.python.org/issue?@action=redirect&bpo=35088

   (25) https://bugs.python.org/issue?@action=redirect&bpo=35087

   (26) https://bugs.python.org/issue?@action=redirect&bpo=34548

   (27) https://bugs.python.org/issue?@action=redirect&bpo=1529353

   (28) https://bugs.python.org/issue?@action=redirect&bpo=34047

   (29) https://bugs.python.org/issue?@action=redirect&bpo=34275

   (30) https://bugs.python.org/issue?@action=redirect&bpo=34120

   (31) https://bugs.python.org/issue?@action=redirect&bpo=33975

   (32) https://bugs.python.org/issue?@action=redirect&bpo=33905

   (33) https://bugs.python.org/issue?@action=redirect&bpo=33924

   (34) https://bugs.python.org/issue?@action=redirect&bpo=33906

   (35) https://bugs.python.org/issue?@action=redirect&bpo=33917

   (36) https://bugs.python.org/issue?@action=redirect&bpo=33904

   (37) https://bugs.python.org/issue?@action=redirect&bpo=33907

   (38) https://bugs.python.org/issue?@action=redirect&bpo=33856

   (39) https://bugs.python.org/issue?@action=redirect&bpo=33839

   (40) https://bugs.python.org/issue?@action=redirect&bpo=33855

   (41) https://bugs.python.org/issue?@action=redirect&bpo=33656

   (42) https://bugs.python.org/issue?@action=redirect&bpo=33768

   (43) https://bugs.python.org/issue?@action=redirect&bpo=33763

   (44) https://bugs.python.org/issue?@action=redirect&bpo=33664

   (45) https://bugs.python.org/issue?@action=redirect&bpo=33679

   (46) https://bugs.python.org/issue?@action=redirect&bpo=33642

   (47) https://bugs.python.org/issue?@action=redirect&bpo=33628

   (48) https://bugs.python.org/issue?@action=redirect&bpo=33564

   (49) https://bugs.python.org/issue?@action=redirect&bpo=21474

   (50) https://bugs.python.org/issue?@action=redirect&bpo=33204

   (51) https://bugs.python.org/issue?@action=redirect&bpo=32984

   (52) https://bugs.python.org/issue?@action=redirect&bpo=32940

   (53) https://bugs.python.org/issue?@action=redirect&bpo=32916

   (54) https://bugs.python.org/issue?@action=redirect&bpo=32905

   (55) https://bugs.python.org/issue?@action=redirect&bpo=32874

   (56) https://bugs.python.org/issue?@action=redirect&bpo=32837

   (57) https://bugs.python.org/issue?@action=redirect&bpo=32826

   (58) https://bugs.python.org/issue?@action=redirect&bpo=32831

   (59) https://bugs.python.org/issue?@action=redirect&bpo=32765


File: python.info,  Node: Tools/Demos<37>,  Next: C API<56>,  Prev: IDLE<37>,  Up: Python 3 8 0 alpha 1

1.24.61.10 Tools/Demos
......................

   - bpo-35884(1): Add a benchmark script for timing various ways to
     access variables: ‘Tools/scripts/var_access_benchmark.py’.

   - bpo-34989(2): python-gdb.py now handles errors on computing the
     line number of a Python frame.

   - bpo-20260(3): Argument Clinic now has non-bitwise unsigned int
     converters.

   - bpo-32962(4): python-gdb now catches ‘UnicodeDecodeError’
     exceptions when calling ‘string()’.

   - bpo-32962(5): python-gdb now catches ValueError on read_var(): when
     Python has no debug symbols for example.

   - bpo-33189(6): ‘pygettext.py’ now recognizes only literal strings as
     docstrings and translatable strings, and rejects bytes literals and
     f-string expressions.

   - bpo-31920(7): Fixed handling directories as arguments in the
     ‘pygettext’ script.  Based on patch by Oleg Krasnikov.

   - bpo-29673(8): Fix pystackv and pystack gdbinit macros.

   - bpo-25427(9): Remove the pyvenv script in favor of ‘python3 -m
     venv’ in order to lower confusion as to what Python interpreter a
     virtual environment will be created for.

   - bpo-32885(10): Add an ‘-n’ flag for ‘Tools/scripts/pathfix.py’ to
     disable automatic backup creation (files with ‘~’ suffix).

   - bpo-32222(11): Fix pygettext not extracting docstrings for
     functions with type annotated arguments.  Patch by Toby Harradine.

   - bpo-31583(12): Fix 2to3 for using with –add-suffix option but
     without –output-dir option for relative path to files in current
     directory.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35884

   (2) https://bugs.python.org/issue?@action=redirect&bpo=34989

   (3) https://bugs.python.org/issue?@action=redirect&bpo=20260

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32962

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32962

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33189

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31920

   (8) https://bugs.python.org/issue?@action=redirect&bpo=29673

   (9) https://bugs.python.org/issue?@action=redirect&bpo=25427

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32885

   (11) https://bugs.python.org/issue?@action=redirect&bpo=32222

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31583


File: python.info,  Node: C API<56>,  Prev: Tools/Demos<37>,  Up: Python 3 8 0 alpha 1

1.24.61.11 C API
................

   - bpo-35713(1): The ‘PyByteArray_Init()’ and ‘PyByteArray_Fini()’
     functions have been removed.  They did nothing since Python 2.7.4
     and Python 3.2.0, were excluded from the limited API (stable ABI),
     and were not documented.

   - bpo-33817(2): Fixed *note _PyBytes_Resize(): 19b6. for empty bytes
     objects.

   - bpo-35322(3): Fix memory leak in *note PyUnicode_EncodeLocale():
     dc5. and *note PyUnicode_EncodeFSDefault(): 1e19. on error
     handling.

   - bpo-35059(4): The following C macros have been converted to static
     inline functions: *note Py_INCREF(): 790, *note Py_DECREF(): 791,
     *note Py_XINCREF(): c5c, *note Py_XDECREF(): 993, *note
     PyObject_INIT(): 1d26, *note PyObject_INIT_VAR(): 1d27.

   - bpo-35296(5): ‘make install’ now also installs the internal API:
     ‘Include/internal/*.h’ header files.

   - bpo-35081(6): Internal APIs surrounded by ‘#ifdef Py_BUILD_CORE’
     have been moved from ‘Include/*.h’ headers to new header files
     ‘Include/internal/pycore_*.h’.

   - bpo-35259(7): Conditionally declare *note Py_FinalizeEx(): f13.
     (new in 3.6) based on Py_LIMITED_API. Patch by Arthur Neufeld.

   - bpo-35081(8): The ‘_PyObject_GC_TRACK()’ and
     ‘_PyObject_GC_UNTRACK()’ macros have been removed from the public C
     API.

   - bpo-35134(9): Creation of a new ‘Include/cpython/’ subdirectory.

   - bpo-34725(10): Adds _Py_SetProgramFullPath so embedders may
     override sys.executable

   - bpo-34910(11): Ensure that *note PyObject_Print(): 1973. always
     returns ‘-1’ on error.  Patch by Zackery Spytz.

   - bpo-34523(12): Py_DecodeLocale() and Py_EncodeLocale() now use the
     UTF-8 encoding on Windows if Py_LegacyWindowsFSEncodingFlag is
     zero.

   - bpo-34193(13): Fix pluralization in TypeError messages in getargs.c
     and typeobject.c: “1 argument” instead of “1 arguments” and “1
     element” instead of “1 elements”.

   - bpo-34127(14): Return grammatically correct error message based on
     argument count.  Patch by Karthikeyan Singaravelan.

   - bpo-23927(15): Fixed *note SystemError: 796. in *note
     PyArg_ParseTupleAndKeywords(): 624. when the ‘w*’ format unit is
     used for optional parameter.

   - bpo-32455(16): Added *note PyCompile_OpcodeStackEffectWithJump():
     1e1a.

   - bpo-34008(17): Py_Main() can again be called after Py_Initialize(),
     as in Python 3.6.

   - bpo-32500(18): Fixed error messages for *note PySequence_Size():
     1e1b, *note PySequence_GetItem(): 1e1c, *note PySequence_SetItem():
     1e1d. and *note PySequence_DelItem(): 1e1e. called with a mapping
     and *note PyMapping_Size(): 1e1f. called with a sequence.

   - bpo-33818(19): *note PyExceptionClass_Name(): c5d. will now return
     ‘const char *’ instead of ‘char *’.

   - bpo-33042(20): Embedding applications may once again call
     PySys_ResetWarnOptions, PySys_AddWarnOption, and PySys_AddXOption
     prior to calling Py_Initialize.

   - bpo-32374(21): Document that m_traverse for multi-phase initialized
     modules can be called with m_state=NULL, and add a sanity check

   - bpo-30863(22): *note PyUnicode_AsWideChar(): 1e20. and *note
     PyUnicode_AsWideCharString(): abb. no longer cache the ‘wchar_t*’
     representation of string objects.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=35713

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33817

   (3) https://bugs.python.org/issue?@action=redirect&bpo=35322

   (4) https://bugs.python.org/issue?@action=redirect&bpo=35059

   (5) https://bugs.python.org/issue?@action=redirect&bpo=35296

   (6) https://bugs.python.org/issue?@action=redirect&bpo=35081

   (7) https://bugs.python.org/issue?@action=redirect&bpo=35259

   (8) https://bugs.python.org/issue?@action=redirect&bpo=35081

   (9) https://bugs.python.org/issue?@action=redirect&bpo=35134

   (10) https://bugs.python.org/issue?@action=redirect&bpo=34725

   (11) https://bugs.python.org/issue?@action=redirect&bpo=34910

   (12) https://bugs.python.org/issue?@action=redirect&bpo=34523

   (13) https://bugs.python.org/issue?@action=redirect&bpo=34193

   (14) https://bugs.python.org/issue?@action=redirect&bpo=34127

   (15) https://bugs.python.org/issue?@action=redirect&bpo=23927

   (16) https://bugs.python.org/issue?@action=redirect&bpo=32455

   (17) https://bugs.python.org/issue?@action=redirect&bpo=34008

   (18) https://bugs.python.org/issue?@action=redirect&bpo=32500

   (19) https://bugs.python.org/issue?@action=redirect&bpo=33818

   (20) https://bugs.python.org/issue?@action=redirect&bpo=33042

   (21) https://bugs.python.org/issue?@action=redirect&bpo=32374

   (22) https://bugs.python.org/issue?@action=redirect&bpo=30863


File: python.info,  Node: Python 3 7 0 final,  Next: Python 3 7 0 release candidate 1,  Prev: Python 3 8 0 alpha 1,  Up: Changelog

1.24.62 Python 3.7.0 final
--------------------------

'Release date: 2018-06-27'

* Menu:

* Library: Library<162>.
* C API: C API<57>.


File: python.info,  Node: Library<162>,  Next: C API<57>,  Up: Python 3 7 0 final

1.24.62.1 Library
.................

   - bpo-33851(1): Fix *note ast.get_docstring(): 1e23. for a node that
     lacks a docstring.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33851


File: python.info,  Node: C API<57>,  Prev: Library<162>,  Up: Python 3 7 0 final

1.24.62.2 C API
...............

   - bpo-33932(1): Calling Py_Initialize() twice does nothing, instead
     of failing with a fatal error: restore the Python 3.6 behaviour.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33932


File: python.info,  Node: Python 3 7 0 release candidate 1,  Next: Python 3 7 0 beta 5,  Prev: Python 3 7 0 final,  Up: Changelog

1.24.63 Python 3.7.0 release candidate 1
----------------------------------------

'Release date: 2018-06-12'

* Menu:

* Core and Builtins: Core and Builtins<159>.
* Library: Library<163>.
* Documentation: Documentation<56>.
* Build: Build<62>.
* Windows: Windows<55>.
* IDLE: IDLE<38>.


File: python.info,  Node: Core and Builtins<159>,  Next: Library<163>,  Up: Python 3 7 0 release candidate 1

1.24.63.1 Core and Builtins
...........................

   - bpo-33803(1): Fix a crash in hamt.c caused by enabling GC tracking
     for an object that hadn’t all of its fields set to NULL.

   - bpo-33706(2): Fix a crash in Python initialization when parsing the
     command line options.  Thanks Christoph Gohlke for the bug report
     and the fix!

   - bpo-30654(3): Fixed reset of the SIGINT handler to SIG_DFL on
     interpreter shutdown even when there was a custom handler set
     previously.  Patch by Philipp Kerling.

   - bpo-31849(4): Fix signed/unsigned comparison warning in pyhash.c.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33803

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33706

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30654

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31849


File: python.info,  Node: Library<163>,  Next: Documentation<56>,  Prev: Core and Builtins<159>,  Up: Python 3 7 0 release candidate 1

1.24.63.2 Library
.................

   - bpo-30167(1): Prevent site.main() exception if PYTHONSTARTUP is
     set.  Patch by Steve Weber.

   - bpo-33812(2): Datetime instance d with non-None tzinfo, but with
     d.tzinfo.utcoffset(d) returning None is now treated as naive by the
     astimezone() method.

   - bpo-30805(3): Avoid race condition with debug logging

   - bpo-33694(4): asyncio: Fix a race condition causing data loss on
     pause_reading()/resume_reading() when using the ProactorEventLoop.

   - bpo-32493(5): Correct test for ‘uuid_enc_be’ availability in
     ‘configure.ac’.  Patch by Michael Felt.

   - bpo-33792(6): Add asyncio.WindowsSelectorEventLoopPolicy and
     asyncio.WindowsProactorEventLoopPolicy.

   - bpo-33778(7): Update ‘unicodedata’’s database to Unicode version
     11.0.0.

   - bpo-33770(8): improve base64 exception message for encoded inputs
     of invalid length

   - bpo-33769(9): asyncio/start_tls: Fix error message; cancel
     callbacks in case of an unhandled error; mark SSLTransport as
     closed if it is aborted.

   - bpo-33767(10): The concatenation (‘+’) and repetition (‘*’)
     sequence operations now raise *note TypeError: 198. instead of
     *note SystemError: 796. when performed on *note mmap.mmap: 51a.
     objects.  Patch by Zackery Spytz.

   - bpo-33734(11): asyncio/ssl: Fix AttributeError, increase default
     handshake timeout

   - bpo-11874(12): Use a better regex when breaking usage into
     wrappable parts.  Avoids bogus assertion errors from custom metavar
     strings.

   - bpo-33582(13): Emit a deprecation warning for inspect.formatargspec

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30167

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33812

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30805

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33694

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32493

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33792

   (7) https://bugs.python.org/issue?@action=redirect&bpo=33778

   (8) https://bugs.python.org/issue?@action=redirect&bpo=33770

   (9) https://bugs.python.org/issue?@action=redirect&bpo=33769

   (10) https://bugs.python.org/issue?@action=redirect&bpo=33767

   (11) https://bugs.python.org/issue?@action=redirect&bpo=33734

   (12) https://bugs.python.org/issue?@action=redirect&bpo=11874

   (13) https://bugs.python.org/issue?@action=redirect&bpo=33582


File: python.info,  Node: Documentation<56>,  Next: Build<62>,  Prev: Library<163>,  Up: Python 3 7 0 release candidate 1

1.24.63.3 Documentation
.......................

   - bpo-33409(1): Clarified the relationship between PEP 538(2)’s
     PYTHONCOERCECLOCALE and PEP 540’s PYTHONUTF8 mode.

   - bpo-33736(3): Improve the documentation of *note
     asyncio.open_connection(): d10, *note asyncio.start_server(): d11.
     and their UNIX socket counterparts.

   - bpo-31432(4): Clarify meaning of CERT_NONE, CERT_OPTIONAL, and
     CERT_REQUIRED flags for ssl.SSLContext.verify_mode.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33409

   (2) https://peps.python.org/pep-0538/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33736

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31432


File: python.info,  Node: Build<62>,  Next: Windows<55>,  Prev: Documentation<56>,  Up: Python 3 7 0 release candidate 1

1.24.63.4 Build
...............

   - bpo-5755(1): Move ‘-Wstrict-prototypes’ option to ‘CFLAGS_NODIST’
     from ‘OPT’.  This option emitted annoying warnings when building
     extension modules written in C++.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5755


File: python.info,  Node: Windows<55>,  Next: IDLE<38>,  Prev: Build<62>,  Up: Python 3 7 0 release candidate 1

1.24.63.5 Windows
.................

   - bpo-33720(1): Reduces maximum marshal recursion depth on release
     builds.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33720


File: python.info,  Node: IDLE<38>,  Prev: Windows<55>,  Up: Python 3 7 0 release candidate 1

1.24.63.6 IDLE
..............

   - bpo-33656(1): On Windows, add API call saying that tk scales for
     DPI. On Windows 8.1+ or 10, with DPI compatibility properties of
     the Python binary unchanged, and a monitor resolution greater than
     96 DPI, this should make text and lines sharper.  It should
     otherwise have no effect.

   - bpo-33768(2): Clicking on a context line moves that line to the top
     of the editor window.

   - bpo-33763(3): IDLE: Use read-only text widget for code context
     instead of label widget.

   - bpo-33664(4): Scroll IDLE editor text by lines.  Previously, the
     mouse wheel and scrollbar slider moved text by a fixed number of
     pixels, resulting in partial lines at the top of the editor box.
     The change also applies to the shell and grep output windows, but
     not to read-only text views.

   - bpo-33679(5): Enable theme-specific color configuration for Code
     Context.  Use the Highlights tab to see the setting for built-in
     themes or add settings to custom themes.

   - bpo-33642(6): Display up to maxlines non-blank lines for Code
     Context.  If there is no current context, show a single blank line.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33656

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33768

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33763

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33664

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33679

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33642


File: python.info,  Node: Python 3 7 0 beta 5,  Next: Python 3 7 0 beta 4,  Prev: Python 3 7 0 release candidate 1,  Up: Changelog

1.24.64 Python 3.7.0 beta 5
---------------------------

'Release date: 2018-05-30'

* Menu:

* Core and Builtins: Core and Builtins<160>.
* Library: Library<164>.
* Documentation: Documentation<57>.
* Tests: Tests<55>.
* Build: Build<63>.
* macOS: macOS<42>.
* IDLE: IDLE<39>.


File: python.info,  Node: Core and Builtins<160>,  Next: Library<164>,  Up: Python 3 7 0 beta 5

1.24.64.1 Core and Builtins
...........................

   - bpo-33622(1): Fixed a leak when the garbage collector fails to add
     an object with the ‘__del__’ method or referenced by it into the
     *note gc.garbage: 13c9. list.  *note PyGC_Collect(): b87. can now
     be called when an exception is set and preserves it.

   - bpo-33509(2): Fix module_globals parameter of
     warnings.warn_explicit(): don’t crash if module_globals is not a
     dict.

   - bpo-20104(3): The new ‘os.posix_spawn’ added in 3.7.0b1 was removed
     as we are still working on what the API should look like.  Expect
     this in 3.8 instead.

   - bpo-33475(4): Fixed miscellaneous bugs in converting annotations to
     strings and optimized parentheses in the string representation.

   - bpo-33391(5): Fix a leak in set_symmetric_difference().

   - bpo-28055(6): Fix unaligned accesses in siphash24().  Patch by Rolf
     Eike Beer.

   - bpo-32911(7): Due to unexpected compatibility issues discovered
     during downstream beta testing, reverted bpo-29463(8).  ‘docstring’
     field is removed from Module, ClassDef, FunctionDef, and
     AsyncFunctionDef ast nodes which was added in 3.7a1.  Docstring
     expression is restored as a first statement in their body.  Based
     on patch by Inada Naoki.

   - bpo-21983(9): Fix a crash in ‘ctypes.cast()’ in case the type
     argument is a ctypes structured data type.  Patch by Eryk Sun and
     Oren Milman.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33622

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33509

   (3) https://bugs.python.org/issue?@action=redirect&bpo=20104

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33475

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33391

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28055

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32911

   (8) https://bugs.python.org/issue?@action=redirect&bpo=29463

   (9) https://bugs.python.org/issue?@action=redirect&bpo=21983


File: python.info,  Node: Library<164>,  Next: Documentation<57>,  Prev: Core and Builtins<160>,  Up: Python 3 7 0 beta 5

1.24.64.2 Library
.................

   - bpo-32751(1): When cancelling the task due to a timeout, *note
     asyncio.wait_for(): 816. will now wait until the cancellation is
     complete.

   - bpo-32684(2): Fix gather to propagate cancellation of itself even
     with return_exceptions.

   - bpo-33654(3): Support protocol type switching in
     SSLTransport.set_protocol().

   - bpo-33674(4): Pause the transport as early as possible to further
     reduce the risk of data_received() being called before
     connection_made().

   - bpo-33674(5): Fix a race condition in SSLProtocol.connection_made()
     of asyncio.sslproto: start immediately the handshake instead of
     using call_soon().  Previously, data_received() could be called
     before the handshake started, causing the handshake to hang or
     fail.

   - bpo-31647(6): Fixed bug where calling write_eof() on a
     _SelectorSocketTransport after it’s already closed raises
     AttributeError.

   - bpo-32610(7): Make asyncio.all_tasks() return only pending tasks.

   - bpo-32410(8): Avoid blocking on file IO in sendfile fallback code

   - bpo-33469(9): Fix RuntimeError after closing loop that used
     run_in_executor

   - bpo-33672(10): Fix Task.__repr__ crash with Cython’s bogus
     coroutines

   - bpo-33654(11): Fix transport.set_protocol() to support switching
     between asyncio.Protocol and asyncio.BufferedProtocol.  Fix
     loop.start_tls() to work with asyncio.BufferedProtocols.

   - bpo-33652(12): Pickles of type variables and subscripted generics
     are now future-proof and compatible with older Python versions.

   - bpo-32493(13): Fixed *note uuid.uuid1(): da3. on FreeBSD.

   - bpo-33618(14): Finalize and document preliminary and experimental
     TLS 1.3 support with OpenSSL 1.1.1

   - bpo-33623(15): Fix possible SIGSGV when asyncio.Future is created
     in __del__

   - bpo-30877(16): Fixed a bug in the Python implementation of the JSON
     decoder that prevented the cache of parsed strings from clearing
     after finishing the decoding.  Based on patch by c-fos.

   - bpo-33570(17): Change TLS 1.3 cipher suite settings for
     compatibility with OpenSSL 1.1.1-pre6 and newer.  OpenSSL 1.1.1
     will have TLS 1.3 ciphers enabled by default.

   - bpo-28556(18): Do not simplify arguments to ‘typing.Union’.  Now
     ‘Union[Manager, Employee]’ is not simplified to ‘Employee’ at
     runtime.  Such simplification previously caused several bugs and
     limited possibilities for introspection.

   - bpo-33540(19): Add a new ‘block_on_close’ class attribute to
     ‘ForkingMixIn’ and ‘ThreadingMixIn’ classes of *note socketserver:
     d2.

   - bpo-33548(20): tempfile._candidate_tempdir_list should consider
     common TEMP locations

   - bpo-33109(21): argparse subparsers are once again not required by
     default, reverting the change in behavior introduced by
     bpo-26510(22) in 3.7.0a2.

   - bpo-33536(23): dataclasses.make_dataclass now checks for invalid
     field names and duplicate fields.  Also, added a check for invalid
     field specifications.

   - bpo-33542(24): Prevent ‘uuid.get_node’ from using a DUID instead of
     a MAC on Windows.  Patch by Zvi Effron

   - bpo-26819(25): Fix race condition with
     ‘ReadTransport.resume_reading’ in Windows proactor event loop.

   - Fix failure in ‘typing.get_type_hints()’ when ClassVar was provided
     as a string forward reference.

   - bpo-33505(26): Optimize asyncio.ensure_future() by reordering if
     checks: 1.17x faster.

   - bpo-33497(27): Add errors param to cgi.parse_multipart and make an
     encoding in FieldStorage use the given errors (needed for Twisted).
     Patch by Amber Brown.

   - bpo-33495(28): Change dataclasses.Fields repr to use the repr of
     each of its members, instead of str.  This makes it more clear what
     each field actually represents.  This is especially true for the
     “type” member.

   - bpo-33453(29): Fix dataclasses to work if using literal string type
     annotations or if using PEP 563 «Postponed Evaluation of
     Annotations».  Only specific string prefixes are detected for both
     ClassVar («ClassVar» and «typing.ClassVar») and InitVar («InitVar»
     and «dataclasses.InitVar»).

   - bpo-28556(30): Minor fixes in typing module: add annotations to
     ‘NamedTuple.__new__’, pass ‘*args’ and ‘**kwds’ in
     ‘Generic.__new__’.  Original PRs by Paulius Šarka and Chad
     Dombrova.

   - bpo-20087(31): Updated alias mapping with glibc 2.27 supported
     locales.

   - bpo-33422(32): Fix trailing quotation marks getting deleted when
     looking up byte/string literals on pydoc.  Patch by Andrés Delfino.

   - bpo-28167(33): The function ‘platform.linux_distribution’ and
     ‘platform.dist’ now trigger a ‘DeprecationWarning’ and have been
     marked for removal in Python 3.8

   - bpo-33197(34): Update error message when constructing invalid
     inspect.Parameters Patch by Donghee Na.

   - bpo-33263(35): Fix FD leak in ‘_SelectorSocketTransport’ Patch by
     Vlad Starostin.

   - bpo-32861(36): The urllib.robotparser’s ‘__str__’ representation
     now includes wildcard entries and the «Crawl-delay» and
     «Request-rate» fields.  Patch by Michael Lazar.

   - bpo-32257(37): The ssl module now contains OP_NO_RENEGOTIATION
     constant, available with OpenSSL 1.1.0h or 1.1.1.

   - bpo-16865(38): Support arrays >=2GiB in *note ctypes: 2e.  Patch by
     Segev Finer.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32751

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32684

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33654

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33674

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33674

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31647

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32610

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32410

   (9) https://bugs.python.org/issue?@action=redirect&bpo=33469

   (10) https://bugs.python.org/issue?@action=redirect&bpo=33672

   (11) https://bugs.python.org/issue?@action=redirect&bpo=33654

   (12) https://bugs.python.org/issue?@action=redirect&bpo=33652

   (13) https://bugs.python.org/issue?@action=redirect&bpo=32493

   (14) https://bugs.python.org/issue?@action=redirect&bpo=33618

   (15) https://bugs.python.org/issue?@action=redirect&bpo=33623

   (16) https://bugs.python.org/issue?@action=redirect&bpo=30877

   (17) https://bugs.python.org/issue?@action=redirect&bpo=33570

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (19) https://bugs.python.org/issue?@action=redirect&bpo=33540

   (20) https://bugs.python.org/issue?@action=redirect&bpo=33548

   (21) https://bugs.python.org/issue?@action=redirect&bpo=33109

   (22) https://bugs.python.org/issue?@action=redirect&bpo=26510

   (23) https://bugs.python.org/issue?@action=redirect&bpo=33536

   (24) https://bugs.python.org/issue?@action=redirect&bpo=33542

   (25) https://bugs.python.org/issue?@action=redirect&bpo=26819

   (26) https://bugs.python.org/issue?@action=redirect&bpo=33505

   (27) https://bugs.python.org/issue?@action=redirect&bpo=33497

   (28) https://bugs.python.org/issue?@action=redirect&bpo=33495

   (29) https://bugs.python.org/issue?@action=redirect&bpo=33453

   (30) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (31) https://bugs.python.org/issue?@action=redirect&bpo=20087

   (32) https://bugs.python.org/issue?@action=redirect&bpo=33422

   (33) https://bugs.python.org/issue?@action=redirect&bpo=28167

   (34) https://bugs.python.org/issue?@action=redirect&bpo=33197

   (35) https://bugs.python.org/issue?@action=redirect&bpo=33263

   (36) https://bugs.python.org/issue?@action=redirect&bpo=32861

   (37) https://bugs.python.org/issue?@action=redirect&bpo=32257

   (38) https://bugs.python.org/issue?@action=redirect&bpo=16865


File: python.info,  Node: Documentation<57>,  Next: Tests<55>,  Prev: Library<164>,  Up: Python 3 7 0 beta 5

1.24.64.3 Documentation
.......................

   - bpo-23859(1): Document that ‘asyncio.wait()’ does not cancel its
     futures on timeout.

   - bpo-32436(2): Document PEP 567(3) changes to asyncio.

   - bpo-33604(4): Update HMAC md5 default to a DeprecationWarning, bump
     removal to 3.8.

   - bpo-33503(5): Fix broken pypi link

   - bpo-33421(6): Add missing documentation for
     ‘typing.AsyncContextManager’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23859

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32436

   (3) https://peps.python.org/pep-0567/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33604

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33503

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33421


File: python.info,  Node: Tests<55>,  Next: Build<63>,  Prev: Documentation<57>,  Up: Python 3 7 0 beta 5

1.24.64.4 Tests
...............

   - bpo-33655(1): Ignore test_posix_fallocate failures on BSD platforms
     that might be due to running on ZFS.

   - bpo-32604(2): Remove the _xxsubinterpreters module (meant for
     testing) and associated helpers.  This module was originally added
     recently in 3.7b1.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33655

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32604


File: python.info,  Node: Build<63>,  Next: macOS<42>,  Prev: Tests<55>,  Up: Python 3 7 0 beta 5

1.24.64.5 Build
...............

   - bpo-33614(1): Ensures module definition files for the stable ABI on
     Windows are correctly regenerated.

   - bpo-33522(2): Enable CI builds on Visual Studio Team Services at
     ‘https://python.visualstudio.com/cpython’

   - bpo-33012(3): Add ‘-Wno-cast-function-type’ for gcc 8 for silencing
     warnings about function casts like casting to PyCFunction in method
     definition lists.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33614

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33522

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33012


File: python.info,  Node: macOS<42>,  Next: IDLE<39>,  Prev: Build<63>,  Up: Python 3 7 0 beta 5

1.24.64.6 macOS
...............

   - bpo-13631(1): The .editrc file in user’s home directory is now
     processed correctly during the readline initialization through
     editline emulation on macOS.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13631


File: python.info,  Node: IDLE<39>,  Prev: macOS<42>,  Up: Python 3 7 0 beta 5

1.24.64.7 IDLE
..............

   - bpo-33628(1): IDLE: Cleanup codecontext.py and its test.

   - bpo-33564(2): IDLE’s code context now recognizes async as a block
     opener.

   - bpo-32831(3): Add docstrings and tests for codecontext.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33628

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33564

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32831


File: python.info,  Node: Python 3 7 0 beta 4,  Next: Python 3 7 0 beta 3,  Prev: Python 3 7 0 beta 5,  Up: Changelog

1.24.65 Python 3.7.0 beta 4
---------------------------

'Release date: 2018-05-02'

* Menu:

* Core and Builtins: Core and Builtins<161>.
* Library: Library<165>.
* Documentation: Documentation<58>.
* Tests: Tests<56>.
* Build: Build<64>.
* Windows: Windows<56>.
* macOS: macOS<43>.
* IDLE: IDLE<40>.
* Tools/Demos: Tools/Demos<38>.


File: python.info,  Node: Core and Builtins<161>,  Next: Library<165>,  Up: Python 3 7 0 beta 4

1.24.65.1 Core and Builtins
...........................

   - bpo-33363(1): Raise a SyntaxError for ‘async with’ and ‘async for’
     statements outside of async functions.

   - bpo-33128(2): Fix a bug that causes PathFinder to appear twice on
     sys.meta_path.  Patch by Pablo Galindo Salgado.

   - bpo-33312(3): Fixed clang ubsan (undefined behavior sanitizer)
     warnings in dictobject.c by adjusting how the internal struct
     _dictkeysobject shared keys structure is declared.

   - bpo-33231(4): Fix potential memory leak in ‘normalizestring()’.

   - bpo-33205(5): Change dict growth function from
     ‘round_up_to_power_2(used*2+hashtable_size/2)’ to
     ‘round_up_to_power_2(used*3)’.  Previously, dict is shrunk only
     when ‘used == 0’.  Now dict has more chance to be shrunk.

   - bpo-29922(6): Improved error messages in “async with” when
     ‘__aenter__()’ or ‘__aexit__()’ return non-awaitable object.

   - bpo-33199(7): Fix ‘ma_version_tag’ in dict implementation is
     uninitialized when copying from key-sharing dict.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33363

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33128

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33312

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33231

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33205

   (6) https://bugs.python.org/issue?@action=redirect&bpo=29922

   (7) https://bugs.python.org/issue?@action=redirect&bpo=33199


File: python.info,  Node: Library<165>,  Next: Documentation<58>,  Prev: Core and Builtins<161>,  Up: Python 3 7 0 beta 4

1.24.65.2 Library
.................

   - bpo-33281(1): Fix ctypes.util.find_library regression on macOS.

   - bpo-33383(2): Fixed crash in the get() method of the *note
     dbm.ndbm: 38. database object when it is called with a single
     argument.

   - bpo-33329(3): Fix multiprocessing regression on newer glibcs

   - bpo-991266(4): Fix quoting of the ‘Comment’ attribute of *note
     http.cookies.SimpleCookie: 1e0c.

   - bpo-33131(5): Upgrade bundled version of pip to 10.0.1.

   - bpo-33308(6): Fixed a crash in the ‘parser’ module when converting
     an ST object to a tree of tuples or lists with ‘line_info=False’
     and ‘col_info=True’.

   - bpo-33266(7): lib2to3 now recognizes ‘rf'...'’ strings.

   - bpo-11594(8): Ensure line-endings are respected when using lib2to3.

   - bpo-33254(9): Have *note importlib.resources.contents(): 504. and
     ‘importlib.abc.ResourceReader.contents()’ return an *note iterable:
     142f. instead of an *note iterator: 4c9.

   - bpo-33256(10): Fix display of ‘<module>’ call in the html produced
     by ‘cgitb.html()’.  Patch by Stéphane Blondon.

   - bpo-33185(11): Fixed regression when running pydoc with the *note
     -m: 23c. switch.  (The regression was introduced in 3.7.0b3 by the
     resolution of bpo-33053(12)) This fix also changed pydoc to add
     ‘os.getcwd()’ to *note sys.path: 3e4. when necessary, rather than
     adding ‘"."’.

   - bpo-33169(13): Delete entries of ‘None’ in *note
     sys.path_importer_cache: 7fb. when
     ‘importlib.machinery.invalidate_caches()’ is called.

   - bpo-33217(14): Deprecate looking up non-Enum objects in Enum
     classes and Enum members (will raise *note TypeError: 198. in
     3.8+).

   - bpo-33203(15): ‘random.Random.choice()’ now raises ‘IndexError’ for
     empty sequences consistently even when called from subclasses
     without a ‘getrandbits()’ implementation.

   - bpo-33224(16): Update difflib.mdiff() for PEP 479(17).  Convert an
     uncaught StopIteration in a generator into a return-statement.

   - bpo-33209(18): End framing at the end of C implementation of *note
     pickle.Pickler.dump(): 1e0d.

   - bpo-20104(19): Improved error handling and fixed a reference leak
     in *note os.posix_spawn(): 52f.

   - bpo-33175(20): In dataclasses, Field.__set_name__ now looks up the
     __set_name__ special method on the class, not the instance, of the
     default value.

   - bpo-33097(21): Raise RuntimeError when ‘executor.submit’ is called
     during interpreter shutdown.

   - bpo-31908(22): Fix output of cover files for ‘trace’ module
     command-line tool.  Previously emitted cover files only when
     ‘--missing’ option was used.  Patch by Michael Selik.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33281

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33383

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33329

   (4) https://bugs.python.org/issue?@action=redirect&bpo=991266

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33131

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33308

   (7) https://bugs.python.org/issue?@action=redirect&bpo=33266

   (8) https://bugs.python.org/issue?@action=redirect&bpo=11594

   (9) https://bugs.python.org/issue?@action=redirect&bpo=33254

   (10) https://bugs.python.org/issue?@action=redirect&bpo=33256

   (11) https://bugs.python.org/issue?@action=redirect&bpo=33185

   (12) https://bugs.python.org/issue?@action=redirect&bpo=33053

   (13) https://bugs.python.org/issue?@action=redirect&bpo=33169

   (14) https://bugs.python.org/issue?@action=redirect&bpo=33217

   (15) https://bugs.python.org/issue?@action=redirect&bpo=33203

   (16) https://bugs.python.org/issue?@action=redirect&bpo=33224

   (17) https://peps.python.org/pep-0479/

   (18) https://bugs.python.org/issue?@action=redirect&bpo=33209

   (19) https://bugs.python.org/issue?@action=redirect&bpo=20104

   (20) https://bugs.python.org/issue?@action=redirect&bpo=33175

   (21) https://bugs.python.org/issue?@action=redirect&bpo=33097

   (22) https://bugs.python.org/issue?@action=redirect&bpo=31908


File: python.info,  Node: Documentation<58>,  Next: Tests<56>,  Prev: Library<165>,  Up: Python 3 7 0 beta 4

1.24.65.3 Documentation
.......................

   - bpo-33378(1): Add Korean language switcher for
     ‘https://docs.python.org/3/’

   - bpo-33276(2): Clarify that the ‘__path__’ attribute on modules
     cannot be just any value.

   - bpo-33201(3): Modernize documentation for writing C extension
     types.

   - bpo-33195(4): Deprecate ‘Py_UNICODE’ usage in ‘c-api/arg’ document.
     ‘Py_UNICODE’ related APIs are deprecated since Python 3.3, but it
     is missed in the document.

   - bpo-8243(5): Add a note about curses.addch and curses.addstr
     exception behavior when writing outside a window, or pad.

   - bpo-32337(6): Update documentation related with ‘dict’ order.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33378

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33276

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33201

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33195

   (5) https://bugs.python.org/issue?@action=redirect&bpo=8243

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32337


File: python.info,  Node: Tests<56>,  Next: Build<64>,  Prev: Documentation<58>,  Up: Python 3 7 0 beta 4

1.24.65.4 Tests
...............

   - bpo-33358(1): Fix
     ‘test_embed.test_pre_initialization_sys_options()’ when the
     interpreter is built with ‘--enable-shared’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33358


File: python.info,  Node: Build<64>,  Next: Windows<56>,  Prev: Tests<56>,  Up: Python 3 7 0 beta 4

1.24.65.5 Build
...............

   - bpo-33394(1): Enable the verbose build for extension modules, when
     GNU make is passed macros on the command line.

   - bpo-33393(2): Update config.guess and config.sub files.

   - bpo-33377(3): Add new triplets for mips r6 and riscv variants (used
     in extension suffixes).

   - bpo-32232(4): By default, modules configured in ‘Modules/Setup’ are
     no longer built with ‘-DPy_BUILD_CORE’.  Instead, modules that
     specifically need that preprocessor definition include it in their
     individual entries.

   - bpo-33182(5): The embedding tests can once again be built with
     clang 6.0

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33394

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33393

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33377

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32232

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33182


File: python.info,  Node: Windows<56>,  Next: macOS<43>,  Prev: Build<64>,  Up: Python 3 7 0 beta 4

1.24.65.6 Windows
.................

   - bpo-33184(1): Update Windows installer to use OpenSSL 1.1.0h.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33184


File: python.info,  Node: macOS<43>,  Next: IDLE<40>,  Prev: Windows<56>,  Up: Python 3 7 0 beta 4

1.24.65.7 macOS
...............

   - bpo-33184(1): Update macOS installer build to use OpenSSL 1.1.0h.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33184


File: python.info,  Node: IDLE<40>,  Next: Tools/Demos<38>,  Prev: macOS<43>,  Up: Python 3 7 0 beta 4

1.24.65.8 IDLE
..............

   - bpo-21474(1): Update word/identifier definition from ascii to
     unicode.  In text and entry boxes, this affects selection by
     double-click, movement left/right by control-left/right, and
     deletion left/right by control-BACKSPACE/DEL.

   - bpo-33204(2): IDLE: consistently color invalid string prefixes.  A
     “u” string prefix cannot be paired with either “r” or “f”.
     Consistently color as much of the prefix, starting at the right, as
     is valid.  Revise and extend colorizer test.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21474

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33204


File: python.info,  Node: Tools/Demos<38>,  Prev: IDLE<40>,  Up: Python 3 7 0 beta 4

1.24.65.9 Tools/Demos
.....................

   - bpo-33189(1): ‘pygettext.py’ now recognizes only literal strings as
     docstrings and translatable strings, and rejects bytes literals and
     f-string expressions.

   - bpo-31920(2): Fixed handling directories as arguments in the
     ‘pygettext’ script.  Based on patch by Oleg Krasnikov.

   - bpo-29673(3): Fix pystackv and pystack gdbinit macros.

   - bpo-31583(4): Fix 2to3 for using with –add-suffix option but
     without –output-dir option for relative path to files in current
     directory.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33189

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31920

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29673

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31583


File: python.info,  Node: Python 3 7 0 beta 3,  Next: Python 3 7 0 beta 2,  Prev: Python 3 7 0 beta 4,  Up: Changelog

1.24.66 Python 3.7.0 beta 3
---------------------------

'Release date: 2018-03-29'

* Menu:

* Security: Security<47>.
* Core and Builtins: Core and Builtins<162>.
* Library: Library<166>.
* Documentation: Documentation<59>.
* Tests: Tests<57>.
* Build: Build<65>.
* Windows: Windows<57>.
* macOS: macOS<44>.
* IDLE: IDLE<41>.
* Tools/Demos: Tools/Demos<39>.
* C API: C API<58>.


File: python.info,  Node: Security<47>,  Next: Core and Builtins<162>,  Up: Python 3 7 0 beta 3

1.24.66.1 Security
..................

   - bpo-33136(1): Harden ssl module against LibreSSL CVE 2018-8970(2).
     X509_VERIFY_PARAM_set1_host() is called with an explicit namelen.
     A new test ensures that NULL bytes are not allowed.

   - bpo-33001(3): Minimal fix to prevent buffer overrun in os.symlink
     on Windows

   - bpo-32981(4): Regexes in difflib and poplib were vulnerable to
     catastrophic backtracking.  These regexes formed potential DOS
     vectors (REDOS). They have been refactored.  This resolves CVE
     2018-1060(5) and CVE 2018-1061(6).  Patch by Jamie Davis.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33136

   (2) https://www.cve.org/CVERecord?id=CVE-2018-8970

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33001

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32981

   (5) https://www.cve.org/CVERecord?id=CVE-2018-1060

   (6) https://www.cve.org/CVERecord?id=CVE-2018-1061


File: python.info,  Node: Core and Builtins<162>,  Next: Library<166>,  Prev: Security<47>,  Up: Python 3 7 0 beta 3

1.24.66.2 Core and Builtins
...........................

   - bpo-33053(1): When using the -m switch, sys.path[0] is now
     explicitly expanded as the 'starting' working directory, rather
     than being left as the empty path (which allows imports from the
     current working directory at the time of the import)

   - bpo-33018(2): Improve consistency of errors raised by
     ‘issubclass()’ when called with a non-class and an abstract base
     class as the first and second arguments, respectively.  Patch by
     Josh Bronson.

   - bpo-33041(3): Fixed jumping when the function contains an ‘async
     for’ loop.

   - bpo-33026(4): Fixed jumping out of «with» block by setting
     f_lineno.

   - bpo-33005(5): Fix a crash on fork when using a custom memory
     allocator (ex: using PYTHONMALLOC env var).  _PyGILState_Reinit()
     and _PyInterpreterState_Enable() now use the default RAW memory
     allocator to allocate a new interpreters mutex on fork.

   - bpo-17288(6): Prevent jumps from “return” and “exception” trace
     events.

   - bpo-32836(7): Don’t use temporary variables in cases of
     list/dict/set comprehensions

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33053

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33018

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33041

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33026

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33005

   (6) https://bugs.python.org/issue?@action=redirect&bpo=17288

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32836


File: python.info,  Node: Library<166>,  Next: Documentation<59>,  Prev: Core and Builtins<162>,  Up: Python 3 7 0 beta 3

1.24.66.3 Library
.................

   - bpo-33141(1): Have Field objects pass through __set_name__ to their
     default values, if they have their own __set_name__.

   - bpo-33096(2): Allow ttk.Treeview.insert to insert iid that has a
     false boolean value.  Note iid=0 and iid=False would be same.
     Patch by Garvit Khatri.

   - bpo-32873(3): Treat type variables and special typing forms as
     immutable by copy and pickle.  This fixes several minor issues and
     inconsistencies, and improves backwards compatibility with Python
     3.6.

   - bpo-33134(4): When computing dataclass’s __hash__, use the lookup
     table to contain the function which returns the __hash__ value.
     This is an improvement over looking up a string, and then testing
     that string to see what to do.

   - bpo-33127(5): The ssl module now compiles with LibreSSL 2.7.1.

   - bpo-32505(6): Raise TypeError if a member variable of a dataclass
     is of type Field, but doesn’t have a type annotation.

   - bpo-33078(7): Fix the failure on OSX caused by the tests relying on
     sem_getvalue

   - bpo-33116(8): Add “Field” to dataclasses.__all__.

   - bpo-32896(9): Fix an error where subclassing a dataclass with a
     field that uses a default_factory would generate an incorrect
     class.

   - bpo-33100(10): Dataclasses: If a field has a default value that’s a
     MemberDescriptorType, then it’s from that field being in __slots__,
     not an actual default value.

   - bpo-32953(11): If a non-dataclass inherits from a frozen dataclass,
     allow attributes to be added to the derived class.  Only attributes
     from the frozen dataclass cannot be assigned to.  Require all
     dataclasses in a hierarchy to be either all frozen or all
     non-frozen.

   - bpo-33061(12): Add missing ‘NoReturn’ to ‘__all__’ in typing.py

   - bpo-33078(13): Fix the size handling in multiprocessing.Queue when
     a pickling error occurs.

   - bpo-33064(14): lib2to3 now properly supports trailing commas after
     ‘*args’ and ‘**kwargs’ in function signatures.

   - bpo-33056(15): FIX properly close leaking fds in
     concurrent.futures.ProcessPoolExecutor.

   - bpo-33021(16): Release the GIL during fstat() calls, avoiding hang
     of all threads when calling mmap.mmap(), os.urandom(), and
     random.seed().  Patch by Nir Soffer.

   - bpo-31804(17): Avoid failing in multiprocessing.Process if the
     standard streams are closed or None at exit.

   - bpo-33037(18): Skip sending/receiving data after SSL transport
     closing.

   - bpo-27683(19): Fix a regression in *note ipaddress: 84. that result
     of ‘hosts()’ is empty when the network is constructed by a tuple
     containing an integer mask and only 1 bit left for addresses.

   - bpo-32999(20): Fix C implementation of ‘ABC.__subclasscheck__(cls,
     subclass)’ crashed when ‘subclass’ is not a type object.

   - bpo-33009(21): Fix inspect.signature() for single-parameter
     partialmethods.

   - bpo-32969(22): Expose several missing constants in zlib and fix
     corresponding documentation.

   - bpo-32056(23): Improved exceptions raised for invalid number of
     channels and sample width when read an audio file in modules
     ‘aifc’, *note wave: 119. and ‘sunau’.

   - bpo-32844(24): Fix wrong redirection of a low descriptor (0 or 1)
     to stderr in subprocess if another low descriptor is closed.

   - bpo-32857(25): In *note tkinter: f6, ‘after_cancel(None)’ now
     raises a *note ValueError: 2ec. instead of canceling the first
     scheduled function.  Patch by Cheryl Sabella.

   - bpo-31639(26): http.server now exposes a ThreadedHTTPServer class
     and uses it when the module is run with ‘-m’ to cope with web
     browsers pre-opening sockets.

   - bpo-27645(27): *note sqlite3.Connection: 54e. now exposes a *note
     backup: d75. method, if the underlying SQLite library is at version
     3.6.11 or higher.  Patch by Lele Gaifax.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33141

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33096

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32873

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33134

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33127

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32505

   (7) https://bugs.python.org/issue?@action=redirect&bpo=33078

   (8) https://bugs.python.org/issue?@action=redirect&bpo=33116

   (9) https://bugs.python.org/issue?@action=redirect&bpo=32896

   (10) https://bugs.python.org/issue?@action=redirect&bpo=33100

   (11) https://bugs.python.org/issue?@action=redirect&bpo=32953

   (12) https://bugs.python.org/issue?@action=redirect&bpo=33061

   (13) https://bugs.python.org/issue?@action=redirect&bpo=33078

   (14) https://bugs.python.org/issue?@action=redirect&bpo=33064

   (15) https://bugs.python.org/issue?@action=redirect&bpo=33056

   (16) https://bugs.python.org/issue?@action=redirect&bpo=33021

   (17) https://bugs.python.org/issue?@action=redirect&bpo=31804

   (18) https://bugs.python.org/issue?@action=redirect&bpo=33037

   (19) https://bugs.python.org/issue?@action=redirect&bpo=27683

   (20) https://bugs.python.org/issue?@action=redirect&bpo=32999

   (21) https://bugs.python.org/issue?@action=redirect&bpo=33009

   (22) https://bugs.python.org/issue?@action=redirect&bpo=32969

   (23) https://bugs.python.org/issue?@action=redirect&bpo=32056

   (24) https://bugs.python.org/issue?@action=redirect&bpo=32844

   (25) https://bugs.python.org/issue?@action=redirect&bpo=32857

   (26) https://bugs.python.org/issue?@action=redirect&bpo=31639

   (27) https://bugs.python.org/issue?@action=redirect&bpo=27645


File: python.info,  Node: Documentation<59>,  Next: Tests<57>,  Prev: Library<166>,  Up: Python 3 7 0 beta 3

1.24.66.4 Documentation
.......................

   - bpo-33126(1): Document PyBuffer_ToContiguous().

   - bpo-27212(2): Modify documentation for the ‘islice()’ recipe to
     consume initial values up to the start index.

   - bpo-28247(3): Update *note zipapp: 136. documentation to describe
     how to make standalone applications.

   - bpo-18802(4): Documentation changes for ipaddress.  Patch by Jon
     Foster and Berker Peksag.

   - bpo-27428(5): Update documentation to clarify that
     ‘WindowsRegistryFinder’ implements ‘MetaPathFinder’.  (Patch by
     Himanshu Lakhara)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33126

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27212

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28247

   (4) https://bugs.python.org/issue?@action=redirect&bpo=18802

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27428


File: python.info,  Node: Tests<57>,  Next: Build<65>,  Prev: Documentation<59>,  Up: Python 3 7 0 beta 3

1.24.66.5 Tests
...............

   - bpo-32872(1): Avoid regrtest compatibility issue with namespace
     packages.

   - bpo-32517(2): Fix failing ‘test_asyncio’ on macOS 10.12.2+ due to
     transport of ‘KqueueSelector’ loop was not being closed.

   - bpo-19417(3): Add test_bdb.py.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32872

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32517

   (3) https://bugs.python.org/issue?@action=redirect&bpo=19417


File: python.info,  Node: Build<65>,  Next: Windows<57>,  Prev: Tests<57>,  Up: Python 3 7 0 beta 3

1.24.66.6 Build
...............

   - bpo-33163(1): Upgrade pip to 9.0.3 and setuptools to v39.0.1.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33163


File: python.info,  Node: Windows<57>,  Next: macOS<44>,  Prev: Build<65>,  Up: Python 3 7 0 beta 3

1.24.66.7 Windows
.................

   - bpo-33016(1): Fix potential use of uninitialized memory in
     nt._getfinalpathname

   - bpo-32903(2): Fix a memory leak in os.chdir() on Windows if the
     current directory is set to a UNC path.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33016

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32903


File: python.info,  Node: macOS<44>,  Next: IDLE<41>,  Prev: Windows<57>,  Up: Python 3 7 0 beta 3

1.24.66.8 macOS
...............

   - bpo-32726(1): Build and link with private copy of Tcl/Tk 8.6 for
     the macOS 10.6+ installer.  The 10.9+ installer variant already
     does this.  This means that the Python 3.7 provided by the
     python.org macOS installers no longer need or use any external
     versions of Tcl/Tk, either system-provided or user-installed, such
     as ActiveTcl.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32726


File: python.info,  Node: IDLE<41>,  Next: Tools/Demos<39>,  Prev: macOS<44>,  Up: Python 3 7 0 beta 3

1.24.66.9 IDLE
..............

   - bpo-32984(1): Set ‘__file__’ while running a startup file.  Like
     Python, IDLE optionally runs one startup file in the Shell window
     before presenting the first interactive input prompt.  For IDLE,
     ‘-s’ runs a file named in environmental variable ‘IDLESTARTUP’ or
     *note PYTHONSTARTUP: 1b8.; ‘-r file’ runs ‘file’.  Python sets
     ‘__file__’ to the startup file name before running the file and
     unsets it before the first prompt.  IDLE now does the same when run
     normally, without the ‘-n’ option.

   - bpo-32940(2): Simplify and rename StringTranslatePseudoMapping in
     pyparse.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32984

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32940


File: python.info,  Node: Tools/Demos<39>,  Next: C API<58>,  Prev: IDLE<41>,  Up: Python 3 7 0 beta 3

1.24.66.10 Tools/Demos
......................

   - bpo-32885(1): Add an ‘-n’ flag for ‘Tools/scripts/pathfix.py’ to
     disable automatic backup creation (files with ‘~’ suffix).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32885


File: python.info,  Node: C API<58>,  Prev: Tools/Demos<39>,  Up: Python 3 7 0 beta 3

1.24.66.11 C API
................

   - bpo-33042(1): Embedding applications may once again call
     PySys_ResetWarnOptions, PySys_AddWarnOption, and PySys_AddXOption
     prior to calling Py_Initialize.

   - bpo-32374(2): Document that m_traverse for multi-phase initialized
     modules can be called with m_state=NULL, and add a sanity check

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33042

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32374


File: python.info,  Node: Python 3 7 0 beta 2,  Next: Python 3 7 0 beta 1,  Prev: Python 3 7 0 beta 3,  Up: Changelog

1.24.67 Python 3.7.0 beta 2
---------------------------

'Release date: 2018-02-27'

* Menu:

* Security: Security<48>.
* Core and Builtins: Core and Builtins<163>.
* Library: Library<167>.
* Documentation: Documentation<60>.
* Tests: Tests<58>.
* Build: Build<66>.
* Windows: Windows<58>.
* macOS: macOS<45>.
* IDLE: IDLE<42>.
* Tools/Demos: Tools/Demos<40>.


File: python.info,  Node: Security<48>,  Next: Core and Builtins<163>,  Up: Python 3 7 0 beta 2

1.24.67.1 Security
..................

   - bpo-28414(1): The ssl module now allows users to perform their own
     IDN en/decoding when using SNI.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28414


File: python.info,  Node: Core and Builtins<163>,  Next: Library<167>,  Prev: Security<48>,  Up: Python 3 7 0 beta 2

1.24.67.2 Core and Builtins
...........................

   - bpo-32889(1): Update Valgrind suppression list to account for the
     rename of ‘Py_ADDRESS_IN_RANG’ to ‘address_in_range’.

   - bpo-31356(2): Remove the new API added in bpo-31356(3)
     (gc.ensure_disabled() context manager).

   - bpo-32305(4): For namespace packages, ensure that both ‘__file__’
     and ‘__spec__.origin’ are set to None.

   - bpo-32303(5): Make sure ‘__spec__.loader’ matches ‘__loader__’ for
     namespace packages.

   - bpo-32711(6): Fix the warning messages for Python/ast_unparse.c.
     Patch by Stéphane Wirtel

   - bpo-32583(7): Fix possible crashing in builtin Unicode decoders
     caused by write out-of-bound errors when using customized decode
     error handlers.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32889

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31356

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31356

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32305

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32303

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32711

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32583


File: python.info,  Node: Library<167>,  Next: Documentation<60>,  Prev: Core and Builtins<163>,  Up: Python 3 7 0 beta 2

1.24.67.3 Library
.................

   - bpo-32960(1): For dataclasses, disallow inheriting frozen from
     non-frozen classes, and also disallow inheriting non-frozen from
     frozen classes.  This restriction will be relaxed at a future date.

   - bpo-32713(2): Fixed tarfile.itn handling of out-of-bounds float
     values.  Patch by Joffrey Fuhrer.

   - bpo-32951(3): Direct instantiation of SSLSocket and SSLObject
     objects is now prohibited.  The constructors were never documented,
     tested, or designed as public constructors.  Users were suppose to
     use ssl.wrap_socket() or SSLContext.

   - bpo-32929(4): Remove the tri-state parameter «hash», and add the
     boolean «unsafe_hash».  If unsafe_hash is True, add a __hash__
     function, but if a __hash__ exists, raise TypeError.  If
     unsafe_hash is False, add a __hash__ based on the values of eq= and
     frozen=.  The unsafe_hash=False behavior is the same as the old
     hash=None behavior.  unsafe_hash=False is the default, just as
     hash=None used to be.

   - bpo-32947(5): Add OP_ENABLE_MIDDLEBOX_COMPAT and test workaround
     for TLSv1.3 for future compatibility with OpenSSL 1.1.1.

   - bpo-30622(6): The ssl module now detects missing NPN support in
     LibreSSL.

   - bpo-32922(7): dbm.open() now encodes filename with the filesystem
     encoding rather than default encoding.

   - bpo-32859(8): In ‘os.dup2’, don’t check every call whether the
     ‘dup3’ syscall exists or not.

   - bpo-32556(9): nt._getfinalpathname, nt._getvolumepathname and
     nt._getdiskusage now correctly convert from bytes.

   - bpo-25988(10): Emit a *note DeprecationWarning: 1a3. when using or
     importing an ABC directly from *note collections: 1e. rather than
     from *note collections.abc: 1f.

   - bpo-21060(11): Rewrite confusing message from setup.py upload from
     «No dist file created in earlier command» to the more helpful «Must
     create and upload files in one command».

   - bpo-32852(12): Make sure sys.argv remains as a list when running
     trace.

   - bpo-31333(13): ‘_abc’ module is added.  It is a speedup module with
     C implementations for various functions and methods in ‘abc’.
     Creating an ABC subclass and calling ‘isinstance’ or ‘issubclass’
     with an ABC subclass are up to 1.5x faster.  In addition, this
     makes Python start-up up to 10% faster.  Note that the new
     implementation hides internal registry and caches, previously
     accessible via private attributes ‘_abc_registry’, ‘_abc_cache’,
     and ‘_abc_negative_cache’.  There are three debugging helper
     methods that can be used instead ‘_dump_registry’,
     ‘_abc_registry_clear’, and ‘_abc_caches_clear’.

   - bpo-32841(14): Fixed ‘asyncio.Condition’ issue which silently
     ignored cancellation after notifying and cancelling a conditional
     lock.  Patch by Bar Harel.

   - bpo-32819(15): ssl.match_hostname() has been simplified and no
     longer depends on re and ipaddress module for wildcard and IP
     addresses.  Error reporting for invalid wildcards has been
     improved.

   - bpo-32394(16): socket: Remove
     TCP_FASTOPEN,TCP_KEEPCNT,TCP_KEEPIDLE,TCP_KEEPINTVL flags on older
     version Windows during run-time.

   - bpo-31787(17): Fixed refleaks of ‘__init__()’ methods in various
     modules.  (Contributed by Oren Milman)

   - bpo-30157(18): Fixed guessing quote and delimiter in
     csv.Sniffer.sniff() when only the last field is quoted.  Patch by
     Jake Davis.

   - bpo-32792(19): collections.ChainMap() preserves the order of the
     underlying mappings.

   - bpo-32775(20): *note fnmatch.translate(): 1837. no longer produces
     patterns which contain set operations.  Sets starting with “[” or
     containing “–”, “&&”, “~~” or “||” will be interpreted differently
     in regular expressions in future versions.  Currently they emit
     warnings.  fnmatch.translate() now avoids producing patterns
     containing such sets by accident.

   - bpo-32622(21): Implement native fast sendfile for Windows proactor
     event loop.

   - bpo-32777(22): Fix a rare but potential pre-exec child process
     deadlock in subprocess on POSIX systems when marking file
     descriptors inheritable on exec in the child process.  This bug
     appears to have been introduced in 3.4.

   - bpo-32647(23): The ctypes module used to depend on indirect linking
     for dlopen.  The shared extension is now explicitly linked against
     libdl on platforms with dl.

   - bpo-32741(24): Implement ‘asyncio.TimerHandle.when()’ method.

   - bpo-32691(25): Use mod_spec.parent when running modules with pdb

   - bpo-32734(26): Fixed ‘asyncio.Lock()’ safety issue which allowed
     acquiring and locking the same lock multiple times, without it
     being free.  Patch by Bar Harel.

   - bpo-32727(27): Do not include name field in SMTP envelope from
     address.  Patch by Stéphane Wirtel

   - bpo-31453(28): Add TLSVersion constants and
     SSLContext.maximum_version / minimum_version attributes.  The new
     API wraps OpenSSL 1.1
     ‘https://web.archive.org/web/20180309043602/https://www.openssl.org/docs/man1.1.0/ssl/SSL_CTX_set_min_proto_version.html’
     feature.

   - bpo-24334(29): Internal implementation details of ssl module were
     cleaned up.  The SSLSocket has one less layer of indirection.
     Owner and session information are now handled by the SSLSocket and
     SSLObject constructor.  Channel binding implementation has been
     simplified.

   - bpo-31848(30): Fix the error handling in Aifc_read.initfp() when
     the SSND chunk is not found.  Patch by Zackery Spytz.

   - bpo-32585(31): Add Ttk spinbox widget to *note tkinter.ttk: ff.
     Patch by Alan D Moore.

   - bpo-32221(32): Various functions returning tuple containing IPv6
     addresses now omit ‘%scope’ part since the same information is
     already encoded in 'scopeid' tuple item.  Especially this speeds up
     ‘socket.recvfrom()’ when it receives multicast packet since useless
     resolving of network interface name is omitted.

   - bpo-30693(33): The TarFile class now recurses directories in a
     reproducible way.

   - bpo-30693(34): The ZipFile class now recurses directories in a
     reproducible way.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32960

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32713

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32951

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32929

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32947

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30622

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32922

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32859

   (9) https://bugs.python.org/issue?@action=redirect&bpo=32556

   (10) https://bugs.python.org/issue?@action=redirect&bpo=25988

   (11) https://bugs.python.org/issue?@action=redirect&bpo=21060

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32852

   (13) https://bugs.python.org/issue?@action=redirect&bpo=31333

   (14) https://bugs.python.org/issue?@action=redirect&bpo=32841

   (15) https://bugs.python.org/issue?@action=redirect&bpo=32819

   (16) https://bugs.python.org/issue?@action=redirect&bpo=32394

   (17) https://bugs.python.org/issue?@action=redirect&bpo=31787

   (18) https://bugs.python.org/issue?@action=redirect&bpo=30157

   (19) https://bugs.python.org/issue?@action=redirect&bpo=32792

   (20) https://bugs.python.org/issue?@action=redirect&bpo=32775

   (21) https://bugs.python.org/issue?@action=redirect&bpo=32622

   (22) https://bugs.python.org/issue?@action=redirect&bpo=32777

   (23) https://bugs.python.org/issue?@action=redirect&bpo=32647

   (24) https://bugs.python.org/issue?@action=redirect&bpo=32741

   (25) https://bugs.python.org/issue?@action=redirect&bpo=32691

   (26) https://bugs.python.org/issue?@action=redirect&bpo=32734

   (27) https://bugs.python.org/issue?@action=redirect&bpo=32727

   (28) https://bugs.python.org/issue?@action=redirect&bpo=31453

   (29) https://bugs.python.org/issue?@action=redirect&bpo=24334

   (30) https://bugs.python.org/issue?@action=redirect&bpo=31848

   (31) https://bugs.python.org/issue?@action=redirect&bpo=32585

   (32) https://bugs.python.org/issue?@action=redirect&bpo=32221

   (33) https://bugs.python.org/issue?@action=redirect&bpo=30693

   (34) https://bugs.python.org/issue?@action=redirect&bpo=30693


File: python.info,  Node: Documentation<60>,  Next: Tests<58>,  Prev: Library<167>,  Up: Python 3 7 0 beta 2

1.24.67.4 Documentation
.......................

   - bpo-28124(1): The ssl module function ssl.wrap_socket() has been
     de-emphasized and deprecated in favor of the more secure and
     efficient SSLContext.wrap_socket() method.

   - bpo-17232(2): Clarify docs for -O and -OO. Patch by Terry Reedy.

   - bpo-32436(3): Add documentation for the contextvars module (PEP
     567).

   - bpo-32800(4): Update link to w3c doc for xml default namespaces.

   - bpo-11015(5): Update *note test.support: ea. documentation.

   - bpo-8722(6): Document ‘__getattr__()’ behavior when property
     ‘get()’ method raises *note AttributeError: 5f0.

   - bpo-32614(7): Modify RE examples in documentation to use raw
     strings to prevent *note DeprecationWarning: 1a3. and add text to
     REGEX HOWTO to highlight the deprecation.

   - bpo-31972(8): Improve docstrings for ‘pathlib.PurePath’ subclasses.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28124

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17232

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32436

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32800

   (5) https://bugs.python.org/issue?@action=redirect&bpo=11015

   (6) https://bugs.python.org/issue?@action=redirect&bpo=8722

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32614

   (8) https://bugs.python.org/issue?@action=redirect&bpo=31972


File: python.info,  Node: Tests<58>,  Next: Build<66>,  Prev: Documentation<60>,  Up: Python 3 7 0 beta 2

1.24.67.5 Tests
...............

   - bpo-31809(1): Add tests to verify connection with secp ECDH curves.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31809


File: python.info,  Node: Build<66>,  Next: Windows<58>,  Prev: Tests<58>,  Up: Python 3 7 0 beta 2

1.24.67.6 Build
...............

   - bpo-32898(1): Fix the python debug build when using COUNT_ALLOCS.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32898


File: python.info,  Node: Windows<58>,  Next: macOS<45>,  Prev: Build<66>,  Up: Python 3 7 0 beta 2

1.24.67.7 Windows
.................

   - bpo-32901(1): Update Tcl and Tk versions to 8.6.8

   - bpo-31966(2): Fixed WindowsConsoleIO.write() for writing empty
     data.

   - bpo-32409(3): Ensures activate.bat can handle Unicode contents.

   - bpo-32457(4): Improves handling of denormalized executable path
     when launching Python.

   - bpo-32370(5): Use the correct encoding for ipconfig output in the
     uuid module.  Patch by Segev Finer.

   - bpo-29248(6): Fix *note os.readlink(): b1c. on Windows, which was
     mistakenly treating the ‘PrintNameOffset’ field of the reparse data
     buffer as a number of characters instead of bytes.  Patch by Craig
     Holmquist and SSE4.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32901

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31966

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32409

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32457

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32370

   (6) https://bugs.python.org/issue?@action=redirect&bpo=29248


File: python.info,  Node: macOS<45>,  Next: IDLE<42>,  Prev: Windows<58>,  Up: Python 3 7 0 beta 2

1.24.67.8 macOS
...............

   - bpo-32901(1): Update macOS 10.9+ installer to Tcl/Tk 8.6.8.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32901


File: python.info,  Node: IDLE<42>,  Next: Tools/Demos<40>,  Prev: macOS<45>,  Up: Python 3 7 0 beta 2

1.24.67.9 IDLE
..............

   - bpo-32916(1): Change ‘str’ to ‘code’ in pyparse.

   - bpo-32905(2): Remove unused code in pyparse module.

   - bpo-32874(3): Add tests for pyparse.

   - bpo-32837(4): Using the system and place-dependent default encoding
     for open() is a bad idea for IDLE’s system and location-independent
     files.

   - bpo-32826(5): Add «encoding=utf-8» to open() in IDLE’s
     test_help_about.  GUI test test_file_buttons() only looks at
     initial ascii-only lines, but failed on systems where open()
     defaults to “ascii” because readline() internally reads and decodes
     far enough ahead to encounter a non-ascii character in CREDITS.txt.

   - bpo-32765(6): Update configdialog General tab docstring to add new
     widgets to the widget list.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32916

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32905

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32874

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32837

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32826

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32765


File: python.info,  Node: Tools/Demos<40>,  Prev: IDLE<42>,  Up: Python 3 7 0 beta 2

1.24.67.10 Tools/Demos
......................

   - bpo-32222(1): Fix pygettext not extracting docstrings for functions
     with type annotated arguments.  Patch by Toby Harradine.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32222


File: python.info,  Node: Python 3 7 0 beta 1,  Next: Python 3 7 0 alpha 4,  Prev: Python 3 7 0 beta 2,  Up: Changelog

1.24.68 Python 3.7.0 beta 1
---------------------------

'Release date: 2018-01-30'

* Menu:

* Core and Builtins: Core and Builtins<164>.
* Library: Library<168>.
* Documentation: Documentation<61>.
* Tests: Tests<59>.
* Build: Build<67>.
* Windows: Windows<59>.
* macOS: macOS<46>.
* C API: C API<59>.


File: python.info,  Node: Core and Builtins<164>,  Next: Library<168>,  Up: Python 3 7 0 beta 1

1.24.68.1 Core and Builtins
...........................

   - bpo-32703(1): Fix coroutine’s ResourceWarning when there’s an
     active error set when it’s being finalized.

   - bpo-32650(2): Pdb and other debuggers dependent on bdb.py will
     correctly step over (next command) native coroutines.  Patch by
     Pablo Galindo.

   - bpo-28685(3): Optimize list.sort() and sorted() by using type
     specialized comparisons when possible.

   - bpo-32685(4): Improve suggestion when the Python 2 form of print
     statement is either present on the same line as the header of a
     compound statement or else terminated by a semi-colon instead of a
     newline.  Patch by Nitish Chandra.

   - bpo-32697(5): Python now explicitly preserves the definition order
     of keyword-only parameters.  It’s always preserved their order, but
     this behavior was never guaranteed before; this behavior is now
     guaranteed and tested.

   - bpo-32690(6): The locals() dictionary now displays in the lexical
     order that variables were defined.  Previously, the order was
     reversed.

   - bpo-32677(7): Add ‘.isascii()’ method to ‘str’, ‘bytes’ and
     ‘bytearray’.  It can be used to test that string contains only
     ASCII characters.

   - bpo-32670(8): Enforce PEP 479(9) for all code.  This means that
     manually raising a StopIteration exception from a generator is
     prohibited for all code, regardless of whether “from __future__
     import generator_stop” was used or not.

   - bpo-32591(10): Added built-in support for tracking the origin of
     coroutine objects; see sys.set_coroutine_origin_tracking_depth and
     CoroutineType.cr_origin.  This replaces the asyncio debug mode’s
     use of coroutine wrapping for native coroutine objects.

   - bpo-31368(11): Expose preadv and pwritev system calls in the os
     module.  Patch by Pablo Galindo

   - bpo-32544(12): ‘hasattr(obj, name)’ and ‘getattr(obj, name,
     default)’ are about 4 times faster than before when ‘name’ is not
     found and ‘obj’ doesn’t override ‘__getattr__’ or
     ‘__getattribute__’.

   - bpo-26163(13): Improved frozenset() hash to create more distinct
     hash values when faced with datasets containing many similar
     values.

   - bpo-32550(14): Remove the STORE_ANNOTATION bytecode.

   - bpo-20104(15): Expose posix_spawn as a low level API in the os
     module.  (removed before 3.7.0rc1)

   - bpo-24340(16): Fixed estimation of the code stack size.

   - bpo-32436(17): Implement PEP 567(18) Context Variables.

   - bpo-18533(19): ‘repr()’ on a dict containing its own ‘values()’ or
     ‘items()’ no longer raises ‘RecursionError’; OrderedDict similarly.
     Instead, use ‘...’, as for other recursive structures.  Patch by
     Ben North.

   - bpo-20891(20): Py_Initialize() now creates the GIL. The GIL is no
     longer created «on demand» to fix a race condition when
     PyGILState_Ensure() is called in a non-Python thread.

   - bpo-32028(21): Leading whitespace is now correctly ignored when
     generating suggestions for converting Py2 print statements to Py3
     builtin print function calls.  Patch by Sanyam Khurana.

   - bpo-31179(22): Make dict.copy() up to 5.5 times faster.

   - bpo-31113(23): Get rid of recursion in the compiler for normal
     control flow.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32703

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32650

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28685

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32685

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32697

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32690

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32677

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32670

   (9) https://peps.python.org/pep-0479/

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32591

   (11) https://bugs.python.org/issue?@action=redirect&bpo=31368

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32544

   (13) https://bugs.python.org/issue?@action=redirect&bpo=26163

   (14) https://bugs.python.org/issue?@action=redirect&bpo=32550

   (15) https://bugs.python.org/issue?@action=redirect&bpo=20104

   (16) https://bugs.python.org/issue?@action=redirect&bpo=24340

   (17) https://bugs.python.org/issue?@action=redirect&bpo=32436

   (18) https://peps.python.org/pep-0567/

   (19) https://bugs.python.org/issue?@action=redirect&bpo=18533

   (20) https://bugs.python.org/issue?@action=redirect&bpo=20891

   (21) https://bugs.python.org/issue?@action=redirect&bpo=32028

   (22) https://bugs.python.org/issue?@action=redirect&bpo=31179

   (23) https://bugs.python.org/issue?@action=redirect&bpo=31113


File: python.info,  Node: Library<168>,  Next: Documentation<61>,  Prev: Core and Builtins<164>,  Up: Python 3 7 0 beta 1

1.24.68.2 Library
.................

   - bpo-25988(1): Deprecate exposing the contents of collections.abc in
     the regular collections module.

   - bpo-31429(2): The default cipher suite selection of the ssl module
     now uses a blacklist approach rather than a hard-coded whitelist.
     Python no longer re-enables ciphers that have been blocked by
     OpenSSL security update.  Default cipher suite selection can be
     configured on compile time.

   - bpo-30306(3): contextlib.contextmanager now releases the arguments
     passed to the underlying generator as soon as the context manager
     is entered.  Previously it would keep them alive for as long as the
     context manager was alive, even when not being used as a function
     decorator.  Patch by Martin Teichmann.

   - bpo-21417(4): Added support for setting the compression level for
     zipfile.ZipFile.

   - bpo-32251(5): Implement asyncio.BufferedProtocol (provisional API).

   - bpo-32513(6): In dataclasses, allow easier overriding of dunder
     methods without specifying decorator parameters.

   - bpo-32660(7): *note termios: e7. makes available ‘FIONREAD’,
     ‘FIONCLEX’, ‘FIOCLEX’, ‘FIOASYNC’ and ‘FIONBIO’ also under
     Solaris/derivatives.

   - bpo-27931(8): Fix email address header parsing error when the
     username is an empty quoted string.  Patch by Xiang Zhang.

   - bpo-32659(9): Under Solaris and derivatives, *note os.stat_result:
     16c8. provides a st_fstype attribute.

   - bpo-32662(10): Implement Server.start_serving(),
     Server.serve_forever(), and Server.is_serving() methods.  Add
     “start_serving” keyword parameter to loop.create_server() and
     loop.create_unix_server().

   - bpo-32391(11): Implement *note asyncio.StreamWriter.wait_closed():
     d04. and *note asyncio.StreamWriter.is_closing(): d05. methods

   - bpo-32643(12): Make Task._step, Task._wakeup and
     Future._schedule_callbacks methods private.

   - bpo-32630(13): Refactor decimal module to use contextvars to store
     decimal context.

   - bpo-32622(14): Add ‘asyncio.AbstractEventLoop.sendfile()’ method.

   - bpo-32304(15): distutils” upload command no longer corrupts tar
     files ending with a CR byte, and no longer tries to convert CR to
     CRLF in any of the upload text fields.

   - bpo-32502(16): uuid.uuid1 no longer raises an exception if a 64-bit
     hardware address is encountered.

   - bpo-32596(17): ‘concurrent.futures’ imports ‘ThreadPoolExecutor’
     and ‘ProcessPoolExecutor’ lazily (using PEP 562(18)).  It makes
     ‘import asyncio’ about 15% faster because asyncio uses only
     ‘ThreadPoolExecutor’ by default.

   - bpo-31801(19): Add ‘_ignore_’ to ‘Enum’ so temporary variables can
     be used during class construction without being turned into
     members.

   - bpo-32576(20): Use queue.SimpleQueue() in places where it can be
     invoked from a weakref callback.

   - bpo-32574(21): Fix memory leak in asyncio.Queue, when the queue has
     limited size and it is full, the cancellation of queue.put() can
     cause a memory leak.  Patch by: José Melero.

   - bpo-32521(22): The nis module is now compatible with new libnsl and
     headers location.

   - bpo-32467(23): collections.abc.ValuesView now inherits from
     collections.abc.Collection.

   - bpo-32473(24): Improve ABCMeta._dump_registry() output readability

   - bpo-32102(25): New argument ‘capture_output’ for subprocess.run

   - bpo-32521(26): glibc has removed Sun RPC. Use replacement libtirpc
     headers and library in nis module.

   - bpo-32493(27): UUID module fixes build for FreeBSD/OpenBSD

   - bpo-32503(28): Pickling with protocol 4 no longer creates too small
     frames.

   - bpo-29237(29): Create enum for pstats sorting options

   - bpo-32454(30): Add close(fd) function to the socket module.

   - bpo-25942(31): The subprocess module is now more graceful when
     handling a Ctrl-C KeyboardInterrupt during subprocess.call,
     subprocess.run, or a Popen context manager.  It now waits a short
     amount of time for the child (presumed to have also gotten the
     SIGINT) to exit, before continuing the KeyboardInterrupt exception
     handling.  This still includes a SIGKILL in the call() and run()
     APIs, but at least the child had a chance first.

   - bpo-32433(32): The hmac module now has hmac.digest(), which
     provides an optimized HMAC digest.

   - bpo-28134(33): Sockets now auto-detect family, type and protocol
     from file descriptor by default.

   - bpo-32404(34): Fix bug where *note
     datetime.datetime.fromtimestamp(): 713. did not call __new__ in
     *note datetime.datetime: 4e3. subclasses.

   - bpo-32403(35): Improved speed of *note datetime.date: 1fa. and
     *note datetime.datetime: 4e3. alternate constructors.

   - bpo-32228(36): Ensure that ‘truncate()’ preserves the file position
     (as reported by ‘tell()’) after writes longer than the buffer size.

   - bpo-32410(37): Implement ‘loop.sock_sendfile’ for asyncio event
     loop.

   - bpo-22908(38): Added seek and tell to the ZipExtFile class.  This
     only works if the file object used to open the zipfile is seekable.

   - bpo-32373(39): Add socket.getblocking() method.

   - bpo-32248(40): Add *note importlib.resources: 7f. and
     ‘importlib.abc.ResourceReader’ as the unified API for reading
     resources contained within packages.  Loaders wishing to support
     resource reading must implement the ‘get_resource_reader()’ method.
     File-based and zipimport-based loaders both implement these APIs.
     *note importlib.abc.ResourceLoader: de4. is deprecated in favor of
     these new APIs.

   - bpo-32320(41): collections.namedtuple() now supports default
     values.

   - bpo-29302(42): Add contextlib.AsyncExitStack.  Patch by Alexander
     Mohr and Ilya Kulakov.

   - bpo-31961(43): 'Removed in Python 3.7.0b2.'  The 'args' argument of
     subprocess.Popen can now be a *note path-like object: 5a1.  If
     'args' is given as a sequence, it’s first element can now be a
     *note path-like object: 5a1. as well.

   - bpo-31900(44): The *note locale.localeconv(): dfa. function now
     sets temporarily the ‘LC_CTYPE’ locale to the ‘LC_NUMERIC’ locale
     to decode ‘decimal_point’ and ‘thousands_sep’ byte strings if they
     are non-ASCII or longer than 1 byte, and the ‘LC_NUMERIC’ locale is
     different than the ‘LC_CTYPE’ locale.  This temporary change
     affects other threads.  Same change for the *note str.format():
     834. method when formatting a number (*note int: 19b, *note float:
     196, *note float: 196. and subclasses) with the ‘n’ type (ex:
     ‘'{:n}'.format(1234)’).

   - bpo-31853(45): Use super().method instead of socket.method in
     SSLSocket.  They were there most likely for legacy reasons.

   - bpo-31399(46): The ssl module now uses OpenSSL’s
     X509_VERIFY_PARAM_set1_host() and X509_VERIFY_PARAM_set1_ip() API
     to verify hostname and IP addresses.  Subject common name fallback
     can be disabled with SSLContext.hostname_checks_common_name.

   - bpo-14976(47): Add a queue.SimpleQueue class, an unbounded FIFO
     queue with a reentrant C implementation of put().

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25988

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31429

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30306

   (4) https://bugs.python.org/issue?@action=redirect&bpo=21417

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32251

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32513

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32660

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27931

   (9) https://bugs.python.org/issue?@action=redirect&bpo=32659

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32662

   (11) https://bugs.python.org/issue?@action=redirect&bpo=32391

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32643

   (13) https://bugs.python.org/issue?@action=redirect&bpo=32630

   (14) https://bugs.python.org/issue?@action=redirect&bpo=32622

   (15) https://bugs.python.org/issue?@action=redirect&bpo=32304

   (16) https://bugs.python.org/issue?@action=redirect&bpo=32502

   (17) https://bugs.python.org/issue?@action=redirect&bpo=32596

   (18) https://peps.python.org/pep-0562/

   (19) https://bugs.python.org/issue?@action=redirect&bpo=31801

   (20) https://bugs.python.org/issue?@action=redirect&bpo=32576

   (21) https://bugs.python.org/issue?@action=redirect&bpo=32574

   (22) https://bugs.python.org/issue?@action=redirect&bpo=32521

   (23) https://bugs.python.org/issue?@action=redirect&bpo=32467

   (24) https://bugs.python.org/issue?@action=redirect&bpo=32473

   (25) https://bugs.python.org/issue?@action=redirect&bpo=32102

   (26) https://bugs.python.org/issue?@action=redirect&bpo=32521

   (27) https://bugs.python.org/issue?@action=redirect&bpo=32493

   (28) https://bugs.python.org/issue?@action=redirect&bpo=32503

   (29) https://bugs.python.org/issue?@action=redirect&bpo=29237

   (30) https://bugs.python.org/issue?@action=redirect&bpo=32454

   (31) https://bugs.python.org/issue?@action=redirect&bpo=25942

   (32) https://bugs.python.org/issue?@action=redirect&bpo=32433

   (33) https://bugs.python.org/issue?@action=redirect&bpo=28134

   (34) https://bugs.python.org/issue?@action=redirect&bpo=32404

   (35) https://bugs.python.org/issue?@action=redirect&bpo=32403

   (36) https://bugs.python.org/issue?@action=redirect&bpo=32228

   (37) https://bugs.python.org/issue?@action=redirect&bpo=32410

   (38) https://bugs.python.org/issue?@action=redirect&bpo=22908

   (39) https://bugs.python.org/issue?@action=redirect&bpo=32373

   (40) https://bugs.python.org/issue?@action=redirect&bpo=32248

   (41) https://bugs.python.org/issue?@action=redirect&bpo=32320

   (42) https://bugs.python.org/issue?@action=redirect&bpo=29302

   (43) https://bugs.python.org/issue?@action=redirect&bpo=31961

   (44) https://bugs.python.org/issue?@action=redirect&bpo=31900

   (45) https://bugs.python.org/issue?@action=redirect&bpo=31853

   (46) https://bugs.python.org/issue?@action=redirect&bpo=31399

   (47) https://bugs.python.org/issue?@action=redirect&bpo=14976


File: python.info,  Node: Documentation<61>,  Next: Tests<59>,  Prev: Library<168>,  Up: Python 3 7 0 beta 1

1.24.68.3 Documentation
.......................

   - bpo-32724(1): Add references to some commands in the documentation
     of Pdb.  Patch by Stéphane Wirtel

   - bpo-32649(2): Complete the C API documentation, profiling and
     tracing part with the newly added per-opcode events.

   - bpo-17799(3): Explain real behaviour of sys.settrace and
     sys.setprofile and their C-API counterparts regarding which type of
     events are received in each function.  Patch by Pablo Galindo
     Salgado.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32724

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32649

   (3) https://bugs.python.org/issue?@action=redirect&bpo=17799


File: python.info,  Node: Tests<59>,  Next: Build<67>,  Prev: Documentation<61>,  Up: Python 3 7 0 beta 1

1.24.68.4 Tests
...............

   - bpo-32721(1): Fix test_hashlib to not fail if the _md5 module is
     not built.

   - bpo-28414(2): Add test cases for IDNA 2003 and 2008 host names.
     IDNA 2003 internationalized host names are working since
     bpo-31399(3) has landed.  IDNA 2008 are still broken.

   - bpo-32604(4): Add a new «_xxsubinterpreters» extension module that
     exposes the existing subinterpreter C-API and a new
     cross-interpreter data sharing mechanism.  The module is primarily
     intended for more thorough testing of the existing subinterpreter
     support.  Note that the _xxsubinterpreters module has been removed
     in 3.7.0rc1.

   - bpo-32602(5): Add test certs and test for ECDSA cert and EC/RSA
     dual mode.

   - bpo-32549(6): On Travis CI, Python now Compiles and uses a local
     copy of OpenSSL 1.1.0g for testing.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32721

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28414

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31399

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32604

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32602

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32549


File: python.info,  Node: Build<67>,  Next: Windows<59>,  Prev: Tests<59>,  Up: Python 3 7 0 beta 1

1.24.68.5 Build
...............

   - bpo-32635(1): Fix segfault of the crypt module when libxcrypt is
     provided instead of libcrypt at the system.

   - bpo-32598(2): Use autoconf to detect OpenSSL libs, headers and
     supported features.  The ax_check_openssl M4 macro uses pkg-config
     to locate OpenSSL and falls back to manual search.

   - bpo-32593(3): Drop support of FreeBSD 9 and older.

   - bpo-29708(4): If the ‘SOURCE_DATE_EPOCH’ environment variable is
     set, *note py_compile: b8. will always create hash-based ‘.pyc’
     files.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32635

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32598

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32593

   (4) https://bugs.python.org/issue?@action=redirect&bpo=29708


File: python.info,  Node: Windows<59>,  Next: macOS<46>,  Prev: Build<67>,  Up: Python 3 7 0 beta 1

1.24.68.6 Windows
.................

   - bpo-32588(1): Create standalone _distutils_findvs module and add
     missing _queue module to installer.

   - bpo-29911(2): Ensure separate Modify and Uninstall buttons are
     displayed.

   - bpo-32507(3): Use app-local UCRT install rather than the proper
     update for old versions of Windows.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32588

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29911

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32507


File: python.info,  Node: macOS<46>,  Next: C API<59>,  Prev: Windows<59>,  Up: Python 3 7 0 beta 1

1.24.68.7 macOS
...............

   - bpo-32726(1): Provide an additional, more modern macOS installer
     variant that supports macOS 10.9+ systems in 64-bit mode only.
     Upgrade the supplied third-party libraries to OpenSSL 1.1.0g and to
     SQLite 3.22.0.  The 10.9+ installer now links with and supplies its
     own copy of Tcl/Tk 8.6.

   - bpo-28440(2): No longer add /Library/Python/3.x/site-packages to
     sys.path for macOS framework builds to avoid future conflicts.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32726

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28440


File: python.info,  Node: C API<59>,  Prev: macOS<46>,  Up: Python 3 7 0 beta 1

1.24.68.8 C API
...............

   - bpo-32681(1): Fix uninitialized variable “res” in the C
     implementation of os.dup2.  Patch by Stéphane Wirtel

   - bpo-10381(2): Add C API access to the ‘datetime.timezone’
     constructor and ‘datetime.timezone.UTC’ singleton.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32681

   (2) https://bugs.python.org/issue?@action=redirect&bpo=10381


File: python.info,  Node: Python 3 7 0 alpha 4,  Next: Python 3 7 0 alpha 3,  Prev: Python 3 7 0 beta 1,  Up: Changelog

1.24.69 Python 3.7.0 alpha 4
----------------------------

'Release date: 2018-01-08'

* Menu:

* Core and Builtins: Core and Builtins<165>.
* Library: Library<169>.
* Documentation: Documentation<62>.
* Tests: Tests<60>.
* Windows: Windows<60>.
* Tools/Demos: Tools/Demos<41>.
* C API: C API<60>.


File: python.info,  Node: Core and Builtins<165>,  Next: Library<169>,  Up: Python 3 7 0 alpha 4

1.24.69.1 Core and Builtins
...........................

   - bpo-31975(1): The default warning filter list now starts with a
     «default::DeprecationWarning:__main__» entry, so deprecation
     warnings are once again shown by default in single-file scripts and
     at the interactive prompt.

   - bpo-32226(2): ‘__class_getitem__’ is now an automatic class method.

   - bpo-32399(3): Add AIX uuid library support for RFC4122 using
     uuid_create() in libc.a

   - bpo-32390(4): Fix the compilation failure on AIX after the f_fsid
     field has been added to the object returned by os.statvfs()
     (bpo-32143(5)).  Original patch by Michael Felt.

   - bpo-32379(6): Make MRO computation faster when a class inherits
     from a single base.

   - bpo-32259(7): The error message of a TypeError raised when unpack
     non-iterable is now more specific.

   - bpo-27169(8): The ‘__debug__’ constant is now optimized out at
     compile time.  This fixes also bpo-22091(9).

   - bpo-32329(10): The *note -R: 1e60. option now turns on hash
     randomization when the *note PYTHONHASHSEED: 127f. environment
     variable is set to ‘0’.  Previously, the option was ignored.
     Moreover, ‘sys.flags.hash_randomization’ is now properly set to 0
     when hash randomization is turned off by ‘PYTHONHASHSEED=0’.

   - bpo-30416(11): The optimizer is now protected from spending much
     time doing complex calculations and consuming much memory for
     creating large constants in constant folding.  Increased limits for
     constants that can be produced in constant folding.

   - bpo-32282(12): Fix an unnecessary ifdef in the include of
     VersionHelpers.h in socketmodule on Windows.

   - bpo-30579(13): Implement TracebackType.__new__ to allow
     Python-level creation of traceback objects, and make
     TracebackType.tb_next mutable.

   - bpo-32260(14): Don’t byte swap the input keys to the SipHash
     algorithm on big-endian platforms.  This should ensure siphash
     gives consistent results across platforms.

   - bpo-31506(15): Improve the error message logic for object.__new__
     and object.__init__.  Patch by Sanyam Khurana.

   - bpo-20361(16): ‘-b’ and ‘-bb’ now inject ‘'default::BytesWarning'’
     and ‘error::BytesWarning’ entries into ‘sys.warnoptions’, ensuring
     that they take precedence over any other warning filters configured
     via the ‘-W’ option or the ‘PYTHONWARNINGS’ environment variable.

   - bpo-32230(17): ‘-X dev’ now injects a ‘'default'’ entry into
     sys.warnoptions, ensuring that it behaves identically to actually
     passing ‘-Wdefault’ at the command line.

   - bpo-29240(18): Add a new UTF-8 mode: implementation of the PEP
     540(19).

   - bpo-32226(20): PEP 560(21): Add support for ‘__mro_entries__’ and
     ‘__class_getitem__’.  Implemented by Ivan Levkivskyi.

   - bpo-32225(22): PEP 562(23): Add support for module ‘__getattr__’
     and ‘__dir__’.  Implemented by Ivan Levkivskyi.

   - bpo-31901(24): The ‘atexit’ module now has its callback stored per
     interpreter.

   - bpo-31650(25): Implement PEP 552(26) (Deterministic pycs).  Python
     now supports invalidating bytecode cache files bashed on a source
     content hash rather than source last-modified time.

   - bpo-29469(27): Move constant folding from bytecode layer to AST
     layer.  Original patch by Eugene Toder.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31975

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32226

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32399

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32390

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32143

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32379

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32259

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27169

   (9) https://bugs.python.org/issue?@action=redirect&bpo=22091

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32329

   (11) https://bugs.python.org/issue?@action=redirect&bpo=30416

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32282

   (13) https://bugs.python.org/issue?@action=redirect&bpo=30579

   (14) https://bugs.python.org/issue?@action=redirect&bpo=32260

   (15) https://bugs.python.org/issue?@action=redirect&bpo=31506

   (16) https://bugs.python.org/issue?@action=redirect&bpo=20361

   (17) https://bugs.python.org/issue?@action=redirect&bpo=32230

   (18) https://bugs.python.org/issue?@action=redirect&bpo=29240

   (19) https://peps.python.org/pep-0540/

   (20) https://bugs.python.org/issue?@action=redirect&bpo=32226

   (21) https://peps.python.org/pep-0560/

   (22) https://bugs.python.org/issue?@action=redirect&bpo=32225

   (23) https://peps.python.org/pep-0562/

   (24) https://bugs.python.org/issue?@action=redirect&bpo=31901

   (25) https://bugs.python.org/issue?@action=redirect&bpo=31650

   (26) https://peps.python.org/pep-0552/

   (27) https://bugs.python.org/issue?@action=redirect&bpo=29469


File: python.info,  Node: Library<169>,  Next: Documentation<62>,  Prev: Core and Builtins<165>,  Up: Python 3 7 0 alpha 4

1.24.69.2 Library
.................

   - bpo-32506(1): Now that dict is defined as keeping insertion order,
     drop OrderedDict and just use plain dict.

   - bpo-32279(2): Add params to dataclasses.make_dataclasses(): init,
     repr, eq, order, hash, and frozen.  Pass them through to
     dataclass().

   - bpo-32278(3): Make type information optional on
     dataclasses.make_dataclass().  If omitted, the string “typing.Any”
     is used.

   - bpo-32499(4): Add dataclasses.is_dataclass(obj), which returns True
     if obj is a dataclass or an instance of one.

   - bpo-32468(5): Improve frame repr() to mention filename, code name
     and current line number.

   - bpo-23749(6): asyncio: Implement loop.start_tls()

   - bpo-32441(7): Return the new file descriptor (i.e., the second
     argument) from ‘os.dup2’.  Previously, ‘None’ was always returned.

   - bpo-32422(8): ‘functools.lru_cache’ uses less memory (3 words for
     each cached key) and takes about 1/3 time for cyclic GC.

   - bpo-31721(9): Prevent Python crash from happening when
     Future._log_traceback is set to True manually.  Now it can only be
     set to False, or a ValueError is raised.

   - bpo-32415(10): asyncio: Add Task.get_loop() and Future.get_loop()

   - bpo-26133(11): Don’t unsubscribe signals in asyncio UNIX event loop
     on interpreter shutdown.

   - bpo-32363(12): Make asyncio.Task.set_exception() and set_result()
     raise NotImplementedError.  Task._step() and Future.__await__()
     raise proper exceptions when they are in an invalid state, instead
     of raising an AssertionError.

   - bpo-32357(13): Optimize asyncio.iscoroutine() and
     loop.create_task() for non-native coroutines (e.g.  async/await
     compiled with Cython).  “loop.create_task(python_coroutine)” used
     to be 20% faster than “loop.create_task(cython_coroutine)”.  Now,
     the latter is as fast.

   - bpo-32356(14): asyncio.transport.resume_reading() and
     pause_reading() are now idempotent.  New transport.is_reading()
     method is added.

   - bpo-32355(15): Optimize asyncio.gather(); now up to 15% faster.

   - bpo-32351(16): Use fastpath in asyncio.sleep if delay<0 (2x boost)

   - bpo-32348(17): Optimize asyncio.Future schedule/add/remove
     callback.  The optimization shows 3-6% performance improvements of
     async/await code.

   - bpo-32331(18): Fix socket.settimeout() and socket.setblocking() to
     keep socket.type as is.  Fix socket.socket() constructor to reset
     any bit flags applied to socket’s type.  This change only affects
     OSes that have SOCK_NONBLOCK and/or SOCK_CLOEXEC.

   - bpo-32248(19): Add ‘importlib.abc.ResourceReader’ as an ABC for
     loaders to provide a unified API for reading resources contained
     within packages.  Also add *note importlib.resources: 7f. as the
     port of ‘importlib_resources’.

   - bpo-32311(20): Implement asyncio.create_task(coro) shortcut

   - bpo-32327(21): Convert asyncio functions that were documented as
     coroutines to coroutines.  Affected functions: loop.sock_sendall,
     loop.sock_recv, loop.sock_accept, loop.getaddrinfo,
     loop.getnameinfo.

   - bpo-32323(22): *note urllib.parse.urlsplit(): f3c. does not convert
     zone-id (scope) to lower case for scoped IPv6 addresses in
     hostnames now.

   - bpo-32302(23): Fix bdist_wininst of distutils for CRT v142: it
     binary compatible with CRT v140.

   - bpo-29711(24): Fix ‘stop_serving’ in asyncio proactor loop kill all
     listening servers

   - bpo-32308(25): *note re.sub(): 5a3. now replaces empty matches
     adjacent to a previous non-empty match.

   - bpo-29970(26): Abort asyncio SSLProtocol connection if handshake
     not complete within 10 seconds.

   - bpo-32314(27): Implement asyncio.run().

   - bpo-17852(28): Revert incorrect fix based on misunderstanding of
     _Py_PyAtExit() semantics.

   - bpo-32296(29): Implement asyncio._get_running_loop() and
     get_event_loop() in C. This makes them 4x faster.

   - bpo-32250(30): Implement ‘asyncio.current_task()’ and
     ‘asyncio.all_tasks()’.  Add helpers intended to be used by
     alternative task implementations: ‘asyncio._register_task’,
     ‘asyncio._enter_task’, ‘asyncio._leave_task’ and
     ‘asyncio._unregister_task’.  Deprecate
     ‘asyncio.Task.current_task()’ and ‘asyncio.Task.all_tasks()’.

   - bpo-32255(31): A single empty field is now always quoted when
     written into a CSV file.  This allows to distinguish an empty row
     from a row consisting of a single empty field.  Patch by Licht
     Takeuchi.

   - bpo-32277(32): Raise ‘NotImplementedError’ instead of ‘SystemError’
     on platforms where ‘chmod(..., follow_symlinks=False)’ is not
     supported.  Patch by Anthony Sottile.

   - bpo-30050(33): New argument warn_on_full_buffer to
     signal.set_wakeup_fd lets you control whether Python prints a
     warning on stderr when the wakeup fd buffer overflows.

   - bpo-29137(34): The ‘fpectl’ library has been removed.  It was never
     enabled by default, never worked correctly on x86-64, and it
     changed the Python ABI in ways that caused unexpected breakage of C
     extensions.

   - bpo-32273(35): Move asyncio.test_utils to test.test_asyncio.

   - bpo-32272(36): Remove asyncio.async() function.

   - bpo-32269(37): Add asyncio.get_running_loop() function.

   - bpo-32265(38): All class and static methods of builtin types now
     are correctly classified by inspect.classify_class_attrs() and
     grouped in pydoc output.  Added types.ClassMethodDescriptorType for
     unbound class methods of builtin types.

   - bpo-32253(39): Deprecate ‘yield from lock’, ‘await lock’, ‘with
     (yield from lock)’ and ‘with await lock’ for asyncio
     synchronization primitives.

   - bpo-22589(40): Changed MIME type of .bmp from “image/x-ms-bmp” to
     “image/bmp”

   - bpo-32193(41): Convert asyncio to use 'async/await' syntax.  Old
     styled ‘yield from’ is still supported too.

   - bpo-32206(42): Add support to run modules with pdb

   - bpo-32227(43): ‘functools.singledispatch’ now supports registering
     implementations using type annotations.

   - bpo-15873(44): Added new alternate constructors *note
     datetime.datetime.fromisoformat(): 82b, *note
     datetime.time.fromisoformat(): 82a. and *note
     datetime.date.fromisoformat(): 829. as the inverse operation of
     each classes’s respective ‘isoformat’ methods.

   - bpo-32199(45): The getnode() ip getter now uses “ip link” instead
     of “ip link list”.

   - bpo-32143(46): os.statvfs() includes the f_fsid field from
     statvfs(2)

   - bpo-26439(47): Fix ctypes.util.find_library() for AIX by
     implementing ctypes._aix.find_library() Patch by: Michael Felt

   - bpo-31993(48): The pickler now uses less memory when serializing
     large bytes and str objects into a file.  Pickles created with
     protocol 4 will require less memory for unpickling large bytes and
     str objects.

   - bpo-27456(49): Ensure TCP_NODELAY is set on Linux.  Tests by Victor
     Stinner.

   - bpo-31778(50): ast.literal_eval() is now more strict.  Addition and
     subtraction of arbitrary numbers no longer allowed.

   - bpo-31802(51): Importing native path module (‘posixpath’, ‘ntpath’)
     now works even if the ‘os’ module still is not imported.

   - bpo-30241(52): Add contextlib.AbstractAsyncContextManager.  Patch
     by Jelle Zijlstra.

   - bpo-31699(53): Fix deadlocks in *note
     concurrent.futures.ProcessPoolExecutor: 1d6. when task arguments or
     results cause pickling or unpickling errors.  This should make sure
     that calls to the ‘ProcessPoolExecutor’ API always eventually
     return.

   - bpo-15216(54): ‘TextIOWrapper.reconfigure()’ supports changing
     'encoding', 'errors', and 'newline'.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32506

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32279

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32278

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32499

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32468

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23749

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32441

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32422

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31721

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32415

   (11) https://bugs.python.org/issue?@action=redirect&bpo=26133

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32363

   (13) https://bugs.python.org/issue?@action=redirect&bpo=32357

   (14) https://bugs.python.org/issue?@action=redirect&bpo=32356

   (15) https://bugs.python.org/issue?@action=redirect&bpo=32355

   (16) https://bugs.python.org/issue?@action=redirect&bpo=32351

   (17) https://bugs.python.org/issue?@action=redirect&bpo=32348

   (18) https://bugs.python.org/issue?@action=redirect&bpo=32331

   (19) https://bugs.python.org/issue?@action=redirect&bpo=32248

   (20) https://bugs.python.org/issue?@action=redirect&bpo=32311

   (21) https://bugs.python.org/issue?@action=redirect&bpo=32327

   (22) https://bugs.python.org/issue?@action=redirect&bpo=32323

   (23) https://bugs.python.org/issue?@action=redirect&bpo=32302

   (24) https://bugs.python.org/issue?@action=redirect&bpo=29711

   (25) https://bugs.python.org/issue?@action=redirect&bpo=32308

   (26) https://bugs.python.org/issue?@action=redirect&bpo=29970

   (27) https://bugs.python.org/issue?@action=redirect&bpo=32314

   (28) https://bugs.python.org/issue?@action=redirect&bpo=17852

   (29) https://bugs.python.org/issue?@action=redirect&bpo=32296

   (30) https://bugs.python.org/issue?@action=redirect&bpo=32250

   (31) https://bugs.python.org/issue?@action=redirect&bpo=32255

   (32) https://bugs.python.org/issue?@action=redirect&bpo=32277

   (33) https://bugs.python.org/issue?@action=redirect&bpo=30050

   (34) https://bugs.python.org/issue?@action=redirect&bpo=29137

   (35) https://bugs.python.org/issue?@action=redirect&bpo=32273

   (36) https://bugs.python.org/issue?@action=redirect&bpo=32272

   (37) https://bugs.python.org/issue?@action=redirect&bpo=32269

   (38) https://bugs.python.org/issue?@action=redirect&bpo=32265

   (39) https://bugs.python.org/issue?@action=redirect&bpo=32253

   (40) https://bugs.python.org/issue?@action=redirect&bpo=22589

   (41) https://bugs.python.org/issue?@action=redirect&bpo=32193

   (42) https://bugs.python.org/issue?@action=redirect&bpo=32206

   (43) https://bugs.python.org/issue?@action=redirect&bpo=32227

   (44) https://bugs.python.org/issue?@action=redirect&bpo=15873

   (45) https://bugs.python.org/issue?@action=redirect&bpo=32199

   (46) https://bugs.python.org/issue?@action=redirect&bpo=32143

   (47) https://bugs.python.org/issue?@action=redirect&bpo=26439

   (48) https://bugs.python.org/issue?@action=redirect&bpo=31993

   (49) https://bugs.python.org/issue?@action=redirect&bpo=27456

   (50) https://bugs.python.org/issue?@action=redirect&bpo=31778

   (51) https://bugs.python.org/issue?@action=redirect&bpo=31802

   (52) https://bugs.python.org/issue?@action=redirect&bpo=30241

   (53) https://bugs.python.org/issue?@action=redirect&bpo=31699

   (54) https://bugs.python.org/issue?@action=redirect&bpo=15216


File: python.info,  Node: Documentation<62>,  Next: Tests<60>,  Prev: Library<169>,  Up: Python 3 7 0 alpha 4

1.24.69.3 Documentation
.......................

   - bpo-32418(1): Add get_loop() method to Server and AbstractServer
     classes.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32418


File: python.info,  Node: Tests<60>,  Next: Windows<60>,  Prev: Documentation<62>,  Up: Python 3 7 0 alpha 4

1.24.69.4 Tests
...............

   - bpo-32252(1): Fix faulthandler_suppress_crash_report() used to
     prevent core dump files when testing crashes.  getrlimit() returns
     zero on success.

   - bpo-32002(2): Adjust C locale coercion testing for the empty locale
     and POSIX locale cases to more readily adjust to platform dependent
     behaviour.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32252

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32002


File: python.info,  Node: Windows<60>,  Next: Tools/Demos<41>,  Prev: Tests<60>,  Up: Python 3 7 0 alpha 4

1.24.69.5 Windows
.................

   - bpo-19764(1): Implement support for
     ‘subprocess.Popen(close_fds=True)’ on Windows.  Patch by Segev
     Finer.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19764


File: python.info,  Node: Tools/Demos<41>,  Next: C API<60>,  Prev: Windows<60>,  Up: Python 3 7 0 alpha 4

1.24.69.6 Tools/Demos
.....................

   - bpo-24960(1): 2to3 and lib2to3 can now read pickled grammar files
     using pkgutil.get_data() rather than probing the filesystem.  This
     lets 2to3 and lib2to3 work when run from a zipfile.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24960


File: python.info,  Node: C API<60>,  Prev: Tools/Demos<41>,  Up: Python 3 7 0 alpha 4

1.24.69.7 C API
...............

   - bpo-32030(1): Py_Initialize() doesn’t reset the memory allocators
     to default if the ‘PYTHONMALLOC’ environment variable is not set.

   - bpo-29084(2): Undocumented C API for OrderedDict has been excluded
     from the limited C API. It was added by mistake and actually never
     worked in the limited C API.

   - bpo-32264(3): Moved the pygetopt.h header into internal/, since it
     has no public APIs.

   - bpo-32241(4): ‘Py_SetProgramName()’ and ‘Py_SetPythonHome()’ now
     take the ‘const wchar *’ arguments instead of ‘wchar *’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32030

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29084

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32264

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32241


File: python.info,  Node: Python 3 7 0 alpha 3,  Next: Python 3 7 0 alpha 2,  Prev: Python 3 7 0 alpha 4,  Up: Changelog

1.24.70 Python 3.7.0 alpha 3
----------------------------

'Release date: 2017-12-05'

* Menu:

* Core and Builtins: Core and Builtins<166>.
* Library: Library<170>.
* Documentation: Documentation<63>.
* Tests: Tests<61>.
* Build: Build<68>.
* Windows: Windows<61>.
* macOS: macOS<47>.
* IDLE: IDLE<43>.
* Tools/Demos: Tools/Demos<42>.
* C API: C API<61>.


File: python.info,  Node: Core and Builtins<166>,  Next: Library<170>,  Up: Python 3 7 0 alpha 3

1.24.70.1 Core and Builtins
...........................

   - bpo-32176(1): co_flags.CO_NOFREE is now always set correctly by the
     code object constructor based on freevars and cellvars, rather than
     needing to be set correctly by the caller.  This ensures it will be
     cleared automatically when additional cell references are injected
     into a modified code object and function.

   - bpo-10544(2): Yield expressions are now deprecated in
     comprehensions and generator expressions.  They are still permitted
     in the definition of the outermost iterable, as that is evaluated
     directly in the enclosing scope.

   - bpo-32137(3): The repr of deeply nested dict now raises a
     RecursionError instead of crashing due to a stack overflow.

   - bpo-32096(4): Revert memory allocator changes in the C API: move
     structures back from _PyRuntime to Objects/obmalloc.c.  The memory
     allocators are once again initialized statically, and so
     PyMem_RawMalloc() and Py_DecodeLocale() can be called before
     _PyRuntime_Initialize().

   - bpo-32043(5): Add a new «developer mode»: new «-X dev» command line
     option to enable debug checks at runtime.

   - bpo-32023(6): SyntaxError is now correctly raised when a generator
     expression without parenthesis is used instead of an inheritance
     list in a class definition.  The duplication of the parentheses can
     be omitted only on calls.

   - bpo-32012(7): SyntaxError is now correctly raised when a generator
     expression without parenthesis is passed as an argument, but
     followed by a trailing comma.  A generator expression always needs
     to be directly inside a set of parentheses and cannot have a comma
     on either side.

   - bpo-28180(8): A new internal ‘_Py_SetLocaleFromEnv(category)’
     helper function has been added in order to improve the consistency
     of behaviour across different ‘libc’ implementations (e.g.  Android
     doesn’t support setting the locale from the environment by
     default).

   - bpo-31949(9): Fixed several issues in printing tracebacks
     (PyTraceBack_Print()).  Setting sys.tracebacklimit to 0 or less now
     suppresses printing tracebacks.  Setting sys.tracebacklimit to None
     now causes using the default limit.  Setting sys.tracebacklimit to
     an integer larger than LONG_MAX now means using the limit LONG_MAX
     rather than the default limit.  Fixed integer overflows in the case
     of more than ‘2**31’ traceback items on Windows.  Fixed output
     errors handling.

   - bpo-30696(10): Fix the interactive interpreter looping endlessly
     when no memory.

   - bpo-20047(11): Bytearray methods partition() and rpartition() now
     accept only bytes-like objects as separator, as documented.  In
     particular they now raise TypeError rather of returning a bogus
     result when an integer is passed as a separator.

   - bpo-21720(12): BytesWarning no longer emitted when the 'fromlist'
     argument of ‘__import__()’ or the ‘__all__’ attribute of the module
     contain bytes instances.

   - bpo-31845(13): Environment variables are once more read correctly
     at interpreter startup.

   - bpo-28936(14): Ensure that lexically first syntax error involving a
     parameter and ‘global’ or ‘nonlocal’ is detected first at a given
     scope.  Patch by Ivan Levkivskyi.

   - bpo-31825(15): Fixed OverflowError in the “unicode-escape” codec
     and in codecs.escape_decode() when decode an escaped non-ascii
     byte.

   - bpo-31618(16): The per-frame tracing logic added in 3.7a1 has been
     altered so that ‘frame->f_lineno’ is updated before either ‘"line"’
     or ‘"opcode"’ events are emitted.  Previously, opcode events were
     emitted first, and therefore would occasionally see stale line
     numbers on the frame.  The behavior of this feature has changed
     slightly as a result: when both ‘f_trace_lines’ and
     ‘f_trace_opcodes’ are enabled, line events now occur first.

   - bpo-28603(17): Print the full context/cause chain of exceptions on
     interpreter exit, even if an exception in the chain is unhashable
     or compares equal to later ones.  Patch by Zane Bitter.

   - bpo-31786(18): Fix timeout rounding in the select module to round
     correctly negative timeouts between -1.0 and 0.0.  The functions
     now block waiting for events as expected.  Previously, the call was
     incorrectly non-blocking.  Patch by Pablo Galindo.

   - bpo-31781(19): Prevent crashes when calling methods of an
     uninitialized ‘zipimport.zipimporter’ object.  Patch by Oren
     Milman.

   - bpo-30399(20): Standard repr() of BaseException with a single
     argument no longer contains redundant trailing comma.

   - bpo-31626(21): Fixed a bug in debug memory allocator.  There was a
     write to freed memory after shrinking a memory block.

   - bpo-30817(22): ‘PyErr_PrintEx()’ clears now the ignored exception
     that may be raised by ‘_PySys_SetObjectId()’, for example when no
     memory.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32176

   (2) https://bugs.python.org/issue?@action=redirect&bpo=10544

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32137

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32096

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32043

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32023

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32012

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28180

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31949

   (10) https://bugs.python.org/issue?@action=redirect&bpo=30696

   (11) https://bugs.python.org/issue?@action=redirect&bpo=20047

   (12) https://bugs.python.org/issue?@action=redirect&bpo=21720

   (13) https://bugs.python.org/issue?@action=redirect&bpo=31845

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28936

   (15) https://bugs.python.org/issue?@action=redirect&bpo=31825

   (16) https://bugs.python.org/issue?@action=redirect&bpo=31618

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28603

   (18) https://bugs.python.org/issue?@action=redirect&bpo=31786

   (19) https://bugs.python.org/issue?@action=redirect&bpo=31781

   (20) https://bugs.python.org/issue?@action=redirect&bpo=30399

   (21) https://bugs.python.org/issue?@action=redirect&bpo=31626

   (22) https://bugs.python.org/issue?@action=redirect&bpo=30817


File: python.info,  Node: Library<170>,  Next: Documentation<63>,  Prev: Core and Builtins<166>,  Up: Python 3 7 0 alpha 3

1.24.70.2 Library
.................

   - bpo-28556(1): Two minor fixes for ‘typing’ module: allow shallow
     copying instances of generic classes, improve interaction of
     ‘__init_subclass__’ with generics.  Original PRs by Ivan
     Levkivskyi.

   - bpo-32214(2): PEP 557, Data Classes.  Provides a decorator which
     adds boilerplate methods to classes which use type annotations so
     specify fields.

   - bpo-27240(3): The header folding algorithm for the new email
     policies has been rewritten, which also fixes bpo-30788(4),
     bpo-31831(5), and bpo-32182(6).  In particular, RFC2231 folding is
     now done correctly.

   - bpo-32186(7): io.FileIO.readall() and io.FileIO.read() now release
     the GIL when getting the file size.  Fixed hang of all threads with
     inaccessible NFS server.  Patch by Nir Soffer.

   - bpo-32101(8): Add *note sys.flags.dev_mode: 1e6a. flag

   - bpo-32154(9): The ‘asyncio.windows_utils.socketpair()’ function has
     been removed: use directly *note socket.socketpair(): df2. which is
     available on all platforms since Python 3.5 (before, it wasn’t
     available on Windows).  ‘asyncio.windows_utils.socketpair()’ was
     just an alias to ‘socket.socketpair’ on Python 3.5 and newer.

   - bpo-32089(10): warnings: In development (-X dev) and debug mode
     (pydebug build), use the «default» action for ResourceWarning,
     rather than the «always» action, in the default warnings filters.

   - bpo-32107(11): ‘uuid.getnode()’ now preferentially returns
     universally administered MAC addresses if available, over locally
     administered MAC addresses.  This makes a better guarantee for
     global uniqueness of UUIDs returned from ‘uuid.uuid1()’.  If only
     locally administered MAC addresses are available, the first such
     one found is returned.

   - bpo-23033(12): Wildcard is now supported in hostname when it is one
     and only character in the left most segment of hostname in second
     argument of ‘ssl.match_hostname()’.  Patch by Mandeep Singh.

   - bpo-12239(13): Make ‘msilib.SummaryInformation.GetProperty()’
     return ‘None’ when the value of property is ‘VT_EMPTY’.  Initial
     patch by Mark Mc Mahon.

   - bpo-28334(14): Use *note os.path.expanduser(): c0b. to find the
     ‘~/.netrc’ file in *note netrc.netrc: 1c61.  If it does not exist,
     *note FileNotFoundError: 264. is raised.  Patch by Dimitri
     Merejkowsky.

   - bpo-32121(15): Made ‘tracemalloc.Traceback’ behave more like the
     traceback module, sorting the frames from oldest to most recent.
     ‘Traceback.format()’ now accepts negative 'limit', truncating the
     result to the ‘abs(limit)’ oldest frames.  To get the old
     behaviour, one can use the new 'most_recent_first' argument to
     ‘Traceback.format()’.  (Patch by Jesse Bakker.)

   - bpo-31325(16): Fix wrong usage of *note collections.namedtuple():
     4e1. in the *note RobotFileParser.parse(): 1e6b. method.  Initial
     patch by Robin Wellner.

   - bpo-12382(17): ‘msilib.OpenDatabase()’ now raises a better
     exception message when it couldn’t open or create an MSI file.
     Initial patch by William Tisäter.

   - bpo-19610(18): ‘setup()’ now warns about invalid types for some
     fields.  The ‘distutils.dist.Distribution’ class now warns when
     ‘classifiers’, ‘keywords’ and ‘platforms’ fields are not specified
     as a list or a string.

   - bpo-32071(19): Added the ‘-k’ command-line option to ‘python -m
     unittest’ to run only tests that match the given pattern(s).

   - bpo-10049(20): Added 'nullcontext' no-op context manager to
     contextlib.  This provides a simpler and faster alternative to
     ExitStack() when handling optional context managers.

   - bpo-28684(21): The new test.support.skip_unless_bind_unix_socket()
     decorator is used here to skip asyncio tests that fail because the
     platform lacks a functional bind() function for unix domain sockets
     (as it is the case for non root users on the recent Android
     versions that run now SELinux in enforcing mode).

   - bpo-32110(22): ‘codecs.StreamReader.read(n)’ now returns not more
     than 'n' characters/bytes for non-negative 'n'.  This makes it
     compatible with ‘read()’ methods of other file-like objects.

   - bpo-27535(23): The warnings module doesn’t leak memory anymore in
     the hidden warnings registry for the «ignore» action of warnings
     filters.  warn_explicit() function doesn’t add the warning key to
     the registry anymore for the «ignore» action.

   - bpo-32088(24): warnings: When Python is build is debug mode
     (‘Py_DEBUG’), *note DeprecationWarning: 1a3, *note
     PendingDeprecationWarning: ac8. and *note ImportWarning: 71f.
     warnings are now displayed by default.

   - bpo-1647489(25): Fixed searching regular expression patterns that
     could match an empty string.  Non-empty string can now be correctly
     found after matching an empty string.

   - bpo-25054(26): Added support of splitting on a pattern that could
     match an empty string.

   - bpo-32072(27): Fixed issues with binary plists: Fixed saving
     bytearrays.  Identical objects will be saved only once.  Equal
     references will be load as identical objects.  Added support for
     saving and loading recursive data structures.

   - bpo-32069(28): Drop legacy SSL transport from asyncio,
     ssl.MemoryBIO is always used anyway.

   - bpo-32066(29): asyncio: Support pathlib.Path in
     create_unix_connection; sock arg should be optional

   - bpo-32046(30): Updates 2to3 to convert from
     operator.isCallable(obj) to callable(obj).  Patch by Donghee Na.

   - bpo-32018(31): inspect.signature should follow PEP 8(32), if the
     parameter has an annotation and a default value.  Patch by Donghee
     Na.

   - bpo-32025(33): Add time.thread_time() and time.thread_time_ns()

   - bpo-32037(34): Integers that fit in a signed 32-bit integer will be
     now pickled with protocol 0 using the INT opcode.  This will
     decrease the size of a pickle, speed up pickling and unpickling,
     and make these integers be unpickled as int instances in Python 2.

   - bpo-32034(35): Make asyncio.IncompleteReadError and
     LimitOverrunError pickleable.

   - bpo-32015(36): Fixed the looping of asyncio in the case of
     reconnection the socket during waiting async read/write from/to the
     socket.

   - bpo-32011(37): Restored support of loading marshal files with the
     TYPE_INT64 code.  These files can be produced in Python 2.7.

   - bpo-28369(38): Enhance add_reader/writer check that socket is not
     used by some transport.  Before, only cases when add_reader/writer
     were called with an int FD were supported.  Now the check is
     implemented correctly for all file-like objects.

   - bpo-31976(39): Fix race condition when flushing a file is slow,
     which can cause a segfault if closing the file from another thread.

   - bpo-31985(40): Formally deprecated aifc.openfp, sunau.openfp, and
     wave.openfp.  Since change 7bc817d5ba917528e8bd07ec461c635291e7b06a
     in 1993, openfp in each of the three modules had been pointing to
     that module’s open function as a matter of backwards compatibility,
     though it had been both untested and undocumented.

   - bpo-21862(41): cProfile command line now accepts ‘-m module_name’
     as an alternative to script path.  Patch by Sanyam Khurana.

   - bpo-31970(42): Reduce performance overhead of asyncio debug mode.

   - bpo-31843(43): 'database' argument of sqlite3.connect() now accepts
     a *note path-like object: 5a1, instead of just a string.

   - bpo-31945(44): Add Configurable 'blocksize' to ‘HTTPConnection’ and
     ‘HTTPSConnection’ for improved upload throughput.  Patch by Nir
     Soffer.

   - bpo-31943(45): Add a ‘cancelled()’ method to *note asyncio.Handle:
     1e6c.  Patch by Marat Sharafutdinov.

   - bpo-9678(46): Fixed determining the MAC address in the uuid module:
     Using ifconfig on NetBSD and OpenBSD. Using arp on Linux, FreeBSD,
     NetBSD and OpenBSD. Based on patch by Takayuki Shimizukawa.

   - bpo-30057(47): Fix potential missed signal in signal.signal().

   - bpo-31933(48): Fix Blake2 params leaf_size and node_offset on big
     endian platforms.  Patch by Jack O’Connor.

   - bpo-21423(49): Add an initializer argument to
     {Process,Thread}PoolExecutor

   - bpo-31927(50): Fixed compilation of the socket module on NetBSD 8.
     Fixed assertion failure or reading arbitrary data when parse a
     AF_BLUETOOTH address on NetBSD and DragonFly BSD.

   - bpo-27666(51): Fixed stack corruption in curses.box() and
     curses.ungetmouse() when the size of types chtype or mmask_t is
     less than the size of C long.  curses.box() now accepts characters
     as arguments.  Based on patch by Steve Fink.

   - bpo-31917(52): Add 3 new clock identifiers: *note
     time.CLOCK_BOOTTIME: d89, *note time.CLOCK_PROF: d8a. and *note
     time.CLOCK_UPTIME: d8b.

   - bpo-31897(53): plistlib now catches more errors when read binary
     plists and raises InvalidFileException instead of unexpected
     exceptions.

   - bpo-25720(54): Fix the method for checking pad state of curses
     WINDOW. Patch by Masayuki Yamamoto.

   - bpo-31893(55): Fixed the layout of the kqueue_event structure on
     OpenBSD and NetBSD. Fixed the comparison of the kqueue_event
     objects.

   - bpo-31891(56): Fixed building the curses module on NetBSD.

   - bpo-31884(57): added required constants to subprocess module for
     setting priority on windows

   - bpo-28281(58): Remove year (1-9999) limits on the
     Calendar.weekday() function.  Patch by Mark Gollahon.

   - bpo-31702(59): crypt.mksalt() now allows to specify the number of
     rounds for SHA-256 and SHA-512 hashing.

   - bpo-30639(60): *note inspect.getfile(): 1e6d. no longer computes
     the repr of unknown objects to display in an error message, to
     protect against badly behaved custom reprs.

   - bpo-30768(61): Fix the pthread+semaphore implementation of
     PyThread_acquire_lock_timed() when called with timeout > 0 and
     intr_flag=0: recompute the timeout if sem_timedwait() is
     interrupted by a signal (EINTR). See also the PEP 475(62).

   - bpo-31854(63): Add ‘mmap.ACCESS_DEFAULT’ constant.

   - bpo-31834(64): Use optimized code for BLAKE2 only with SSSE3+.  The
     pure SSE2 implementation is slower than the pure C reference
     implementation.

   - bpo-28292(65): Calendar.itermonthdates() will now consistently
     raise an exception when a date falls outside of the 0001-01-01
     through 9999-12-31 range.  To support applications that cannot
     tolerate such exceptions, the new methods itermonthdays3() and
     itermonthdays4() are added.  The new methods return tuples and are
     not restricted by the range supported by datetime.date.

   - bpo-28564(66): The shutil.rmtree() function has been sped up to
     20–40%.  This was done using the os.scandir() function.

   - bpo-28416(67): Instances of pickle.Pickler subclass with the
     persistent_id() method and pickle.Unpickler subclass with the
     persistent_load() method no longer create reference cycles.

   - bpo-31653(68): Don’t release the GIL if we can acquire a
     multiprocessing semaphore immediately.

   - bpo-28326(69): Fix multiprocessing.Process when stdout and/or
     stderr is closed or None.

   - bpo-20825(70): Add ‘subnet_of’ and ‘superset_of’ containment tests
     to *note ipaddress.IPv6Network: 510. and *note
     ipaddress.IPv4Network: 50f.  Patch by Michel Albert and Cheryl
     Sabella.

   - bpo-31827(71): Remove the os.stat_float_times() function.  It was
     introduced in Python 2.3 for backward compatibility with Python
     2.2, and was deprecated since Python 3.1.

   - bpo-31756(72): Add a ‘subprocess.Popen(text=False)’ keyword
     argument to ‘subprocess’ functions to be more explicit about when
     the library should attempt to decode outputs into text.  Patch by
     Andrew Clegg.

   - bpo-31819(73): Add AbstractEventLoop.sock_recv_into().

   - bpo-31457(74): If nested log adapters are used, the inner
     ‘process()’ methods are no longer omitted.

   - bpo-31457(75): The ‘manager’ property on LoggerAdapter objects is
     now properly settable.

   - bpo-31806(76): Fix timeout rounding in time.sleep(),
     threading.Lock.acquire() and socket.socket.settimeout() to round
     correctly negative timeouts between -1.0 and 0.0.  The functions
     now block waiting for events as expected.  Previously, the call was
     incorrectly non-blocking.  Patch by Pablo Galindo.

   - bpo-31803(77): time.clock() and time.get_clock_info(“clock”) now
     emit a DeprecationWarning warning.

   - bpo-31800(78): Extended support for parsing UTC offsets.  strptime
     “%z” can now parse the output generated by datetime.isoformat,
     including seconds and microseconds.

   - bpo-28603(79): traceback: Fix a TypeError that occurred during
     printing of exception tracebacks when either the current exception
     or an exception in its context/cause chain is unhashable.  Patch by
     Zane Bitter.

   - bpo-30541(80): Add new function to seal a mock and prevent the
     automatically creation of child mocks.  Patch by Mario Corchero.

   - bpo-31784(81): Implement the PEP 564(82), add new 6 new functions
     with nanosecond resolution to the *note time: f4. module: *note
     clock_gettime_ns(): cdd, *note clock_settime_ns(): cde, *note
     monotonic_ns(): cdf, *note perf_counter_ns(): ce0, *note
     process_time_ns(): ce1, *note time_ns(): ce2.

   - bpo-30143(83): 2to3 now generates a code that uses abstract
     collection classes from collections.abc rather than collections.

   - bpo-31770(84): Prevent a crash when calling the ‘__init__()’ method
     of a ‘sqlite3.Cursor’ object more than once.  Patch by Oren Milman.

   - bpo-31764(85): Prevent a crash in ‘sqlite3.Cursor.close()’ in case
     the ‘Cursor’ object is uninitialized.  Patch by Oren Milman.

   - bpo-31752(86): Fix possible crash in timedelta constructor called
     with custom integers.

   - bpo-31620(87): an empty asyncio.Queue now doesn’t leak memory when
     queue.get pollers timeout

   - bpo-31690(88): Allow the flags re.ASCII, re.LOCALE, and re.UNICODE
     to be used as group flags for regular expressions.

   - bpo-30349(89): FutureWarning is now emitted if a regular expression
     contains character set constructs that will change semantically in
     the future (nested sets and set operations).

   - bpo-31664(90): Added support for the Blowfish hashing in the crypt
     module.

   - bpo-31632(91): Fix method set_protocol() of class
     _SSLProtocolTransport in asyncio module.  This method was
     previously modifying a wrong reference to the protocol.

   - bpo-15037(92): Added a workaround for getkey() in curses for
     ncurses 5.7 and earlier.

   - bpo-31307(93): Allow use of bytes objects for arguments to *note
     configparser.ConfigParser.read(): 166f.  Patch by Vincent Michel.

   - bpo-31334(94): Fix ‘poll.poll([timeout])’ in the ‘select’ module
     for arbitrary negative timeouts on all OSes where it can only be a
     non-negative integer or -1.  Patch by Riccardo Coccioli.

   - bpo-31310(95): multiprocessing’s semaphore tracker should be
     launched again if crashed.

   - bpo-31308(96): Make multiprocessing’s forkserver process immune to
     Ctrl-C and other user interruptions.  If it crashes, restart it
     when necessary.

   - bpo-31245(97): Added support for AF_UNIX socket in asyncio
     ‘create_datagram_endpoint’.

   - bpo-30553(98): Add HTTP/2 status code 421 (Misdirected Request) to
     *note http.HTTPStatus: afe.  Patch by Vitor Pereira.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32214

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27240

   (4) https://bugs.python.org/issue?@action=redirect&bpo=30788

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31831

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32182

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32186

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32101

   (9) https://bugs.python.org/issue?@action=redirect&bpo=32154

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32089

   (11) https://bugs.python.org/issue?@action=redirect&bpo=32107

   (12) https://bugs.python.org/issue?@action=redirect&bpo=23033

   (13) https://bugs.python.org/issue?@action=redirect&bpo=12239

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28334

   (15) https://bugs.python.org/issue?@action=redirect&bpo=32121

   (16) https://bugs.python.org/issue?@action=redirect&bpo=31325

   (17) https://bugs.python.org/issue?@action=redirect&bpo=12382

   (18) https://bugs.python.org/issue?@action=redirect&bpo=19610

   (19) https://bugs.python.org/issue?@action=redirect&bpo=32071

   (20) https://bugs.python.org/issue?@action=redirect&bpo=10049

   (21) https://bugs.python.org/issue?@action=redirect&bpo=28684

   (22) https://bugs.python.org/issue?@action=redirect&bpo=32110

   (23) https://bugs.python.org/issue?@action=redirect&bpo=27535

   (24) https://bugs.python.org/issue?@action=redirect&bpo=32088

   (25) https://bugs.python.org/issue?@action=redirect&bpo=1647489

   (26) https://bugs.python.org/issue?@action=redirect&bpo=25054

   (27) https://bugs.python.org/issue?@action=redirect&bpo=32072

   (28) https://bugs.python.org/issue?@action=redirect&bpo=32069

   (29) https://bugs.python.org/issue?@action=redirect&bpo=32066

   (30) https://bugs.python.org/issue?@action=redirect&bpo=32046

   (31) https://bugs.python.org/issue?@action=redirect&bpo=32018

   (32) https://peps.python.org/pep-0008/

   (33) https://bugs.python.org/issue?@action=redirect&bpo=32025

   (34) https://bugs.python.org/issue?@action=redirect&bpo=32037

   (35) https://bugs.python.org/issue?@action=redirect&bpo=32034

   (36) https://bugs.python.org/issue?@action=redirect&bpo=32015

   (37) https://bugs.python.org/issue?@action=redirect&bpo=32011

   (38) https://bugs.python.org/issue?@action=redirect&bpo=28369

   (39) https://bugs.python.org/issue?@action=redirect&bpo=31976

   (40) https://bugs.python.org/issue?@action=redirect&bpo=31985

   (41) https://bugs.python.org/issue?@action=redirect&bpo=21862

   (42) https://bugs.python.org/issue?@action=redirect&bpo=31970

   (43) https://bugs.python.org/issue?@action=redirect&bpo=31843

   (44) https://bugs.python.org/issue?@action=redirect&bpo=31945

   (45) https://bugs.python.org/issue?@action=redirect&bpo=31943

   (46) https://bugs.python.org/issue?@action=redirect&bpo=9678

   (47) https://bugs.python.org/issue?@action=redirect&bpo=30057

   (48) https://bugs.python.org/issue?@action=redirect&bpo=31933

   (49) https://bugs.python.org/issue?@action=redirect&bpo=21423

   (50) https://bugs.python.org/issue?@action=redirect&bpo=31927

   (51) https://bugs.python.org/issue?@action=redirect&bpo=27666

   (52) https://bugs.python.org/issue?@action=redirect&bpo=31917

   (53) https://bugs.python.org/issue?@action=redirect&bpo=31897

   (54) https://bugs.python.org/issue?@action=redirect&bpo=25720

   (55) https://bugs.python.org/issue?@action=redirect&bpo=31893

   (56) https://bugs.python.org/issue?@action=redirect&bpo=31891

   (57) https://bugs.python.org/issue?@action=redirect&bpo=31884

   (58) https://bugs.python.org/issue?@action=redirect&bpo=28281

   (59) https://bugs.python.org/issue?@action=redirect&bpo=31702

   (60) https://bugs.python.org/issue?@action=redirect&bpo=30639

   (61) https://bugs.python.org/issue?@action=redirect&bpo=30768

   (62) https://peps.python.org/pep-0475/

   (63) https://bugs.python.org/issue?@action=redirect&bpo=31854

   (64) https://bugs.python.org/issue?@action=redirect&bpo=31834

   (65) https://bugs.python.org/issue?@action=redirect&bpo=28292

   (66) https://bugs.python.org/issue?@action=redirect&bpo=28564

   (67) https://bugs.python.org/issue?@action=redirect&bpo=28416

   (68) https://bugs.python.org/issue?@action=redirect&bpo=31653

   (69) https://bugs.python.org/issue?@action=redirect&bpo=28326

   (70) https://bugs.python.org/issue?@action=redirect&bpo=20825

   (71) https://bugs.python.org/issue?@action=redirect&bpo=31827

   (72) https://bugs.python.org/issue?@action=redirect&bpo=31756

   (73) https://bugs.python.org/issue?@action=redirect&bpo=31819

   (74) https://bugs.python.org/issue?@action=redirect&bpo=31457

   (75) https://bugs.python.org/issue?@action=redirect&bpo=31457

   (76) https://bugs.python.org/issue?@action=redirect&bpo=31806

   (77) https://bugs.python.org/issue?@action=redirect&bpo=31803

   (78) https://bugs.python.org/issue?@action=redirect&bpo=31800

   (79) https://bugs.python.org/issue?@action=redirect&bpo=28603

   (80) https://bugs.python.org/issue?@action=redirect&bpo=30541

   (81) https://bugs.python.org/issue?@action=redirect&bpo=31784

   (82) https://peps.python.org/pep-0564/

   (83) https://bugs.python.org/issue?@action=redirect&bpo=30143

   (84) https://bugs.python.org/issue?@action=redirect&bpo=31770

   (85) https://bugs.python.org/issue?@action=redirect&bpo=31764

   (86) https://bugs.python.org/issue?@action=redirect&bpo=31752

   (87) https://bugs.python.org/issue?@action=redirect&bpo=31620

   (88) https://bugs.python.org/issue?@action=redirect&bpo=31690

   (89) https://bugs.python.org/issue?@action=redirect&bpo=30349

   (90) https://bugs.python.org/issue?@action=redirect&bpo=31664

   (91) https://bugs.python.org/issue?@action=redirect&bpo=31632

   (92) https://bugs.python.org/issue?@action=redirect&bpo=15037

   (93) https://bugs.python.org/issue?@action=redirect&bpo=31307

   (94) https://bugs.python.org/issue?@action=redirect&bpo=31334

   (95) https://bugs.python.org/issue?@action=redirect&bpo=31310

   (96) https://bugs.python.org/issue?@action=redirect&bpo=31308

   (97) https://bugs.python.org/issue?@action=redirect&bpo=31245

   (98) https://bugs.python.org/issue?@action=redirect&bpo=30553


File: python.info,  Node: Documentation<63>,  Next: Tests<61>,  Prev: Library<170>,  Up: Python 3 7 0 alpha 3

1.24.70.3 Documentation
.......................

   - bpo-32105(1): Added asyncio.BaseEventLoop.connect_accepted_socket
     versionadded marker.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32105


File: python.info,  Node: Tests<61>,  Next: Build<68>,  Prev: Documentation<63>,  Up: Python 3 7 0 alpha 3

1.24.70.4 Tests
...............

   - bpo-31380(1): Skip test_httpservers test_undecodable_file on macOS:
     fails on APFS.

   - bpo-31705(2): Skip test_socket.test_sha256() on Linux kernel older
     than 4.5.  The test fails with ENOKEY on kernel 3.10 (on ppc64le).
     A fix was merged into the kernel 4.5.

   - bpo-32138(3): Skip on Android test_faulthandler tests that raise
     SIGSEGV and remove the test.support.requires_android_level
     decorator.

   - bpo-32136(4): The runtime embedding tests have been split out from
     ‘Lib/test/test_capi.py’ into a new ‘Lib/test/test_embed.py’ file.

   - bpo-28668(5): test.support.requires_multiprocessing_queue is
     removed.  Skip tests with
     test.support.import_module(“multiprocessing.synchronize”) instead
     when the semaphore implementation is broken or missing.

   - bpo-32126(6): Skip test_get_event_loop_new_process in
     test.test_asyncio.test_events when sem_open() is not functional.

   - bpo-31174(7): Fix test_tools.test_unparse: DirectoryTestCase now
     stores the names sample to always test the same files.  It prevents
     false alarms when hunting reference leaks.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31380

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31705

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32138

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32136

   (5) https://bugs.python.org/issue?@action=redirect&bpo=28668

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32126

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31174


File: python.info,  Node: Build<68>,  Next: Windows<61>,  Prev: Tests<61>,  Up: Python 3 7 0 alpha 3

1.24.70.5 Build
...............

   - bpo-28538(1): Revert the previous changes, the if_nameindex
     structure is defined by Unified Headers.

   - bpo-28762(2): Revert the last commit, the F_LOCK macro is defined
     by Android Unified Headers.

   - bpo-29040(3): Support building Android with Unified Headers.  The
     first NDK release to support Unified Headers is android-ndk-r14.

   - bpo-32059(4): ‘detect_modules()’ in ‘setup.py’ now also searches
     the sysroot paths when cross-compiling.

   - bpo-31957(5): Fixes Windows SDK version detection when building for
     Windows.

   - bpo-31609(6): Fixes quotes in PCbuild/clean.bat

   - bpo-31934(7): Abort the build when building out of a not clean
     source tree.

   - bpo-31926(8): Fixed Argument Clinic sometimes causing compilation
     errors when there was more than one function and/or method in a .c
     file with the same name.

   - bpo-28791(9): Update Windows builds to use SQLite 3.21.0.

   - bpo-28791(10): Update OS X installer to use SQLite 3.21.0.

   - bpo-28643(11): Record profile-opt build progress with stamp files.

   - bpo-31866(12): Finish removing support for AtheOS.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28538

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28762

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29040

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32059

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31957

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31609

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31934

   (8) https://bugs.python.org/issue?@action=redirect&bpo=31926

   (9) https://bugs.python.org/issue?@action=redirect&bpo=28791

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28791

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28643

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31866


File: python.info,  Node: Windows<61>,  Next: macOS<47>,  Prev: Build<68>,  Up: Python 3 7 0 alpha 3

1.24.70.6 Windows
.................

   - bpo-1102(1): Return ‘None’ when ‘View.Fetch()’ returns
     ‘ERROR_NO_MORE_ITEMS’ instead of raising ‘MSIError’.  Initial patch
     by Anthony Tuininga.

   - bpo-31944(2): Fixes Modify button in Apps and Features dialog.

   - bpo-20486(3): Implement the ‘Database.Close()’ method to help
     closing MSI database objects.

   - bpo-31857(4): Make the behavior of USE_STACKCHECK deterministic in
     a multi-threaded environment.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1102

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31944

   (3) https://bugs.python.org/issue?@action=redirect&bpo=20486

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31857


File: python.info,  Node: macOS<47>,  Next: IDLE<43>,  Prev: Windows<61>,  Up: Python 3 7 0 alpha 3

1.24.70.7 macOS
...............

   - bpo-31392(1): Update macOS installer to use OpenSSL 1.0.2m

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31392


File: python.info,  Node: IDLE<43>,  Next: Tools/Demos<42>,  Prev: macOS<47>,  Up: Python 3 7 0 alpha 3

1.24.70.8 IDLE
..............

   - bpo-32207(1): Improve tk event exception tracebacks in IDLE. When
     tk event handling is driven by IDLE’s run loop, a confusing and
     distracting queue.EMPTY traceback context is no longer added to tk
     event exception tracebacks.  The traceback is now the same as when
     event handling is driven by user code.  Patch based on a suggestion
     by Serhiy Storchaka.

   - bpo-32164(2): Delete unused file idlelib/tabbedpages.py.  Use of
     TabbedPageSet in configdialog was replaced by ttk.Notebook.

   - bpo-32100(3): IDLE: Fix old and new bugs in pathbrowser; improve
     tests.  Patch mostly by Cheryl Sabella.

   - bpo-31858(4): IDLE – Restrict shell prompt manipulation to the
     shell.  Editor and output windows only see an empty last prompt
     line.  This simplifies the code and fixes a minor bug when newline
     is inserted.  Sys.ps1, if present, is read on Shell start-up, but
     is not set or changed.

   - bpo-31860(5): The font sample in the IDLE configuration dialog is
     now editable.  Changes persist while IDLE remains open

   - bpo-31836(6): Test_code_module now passes if run after test_idle,
     which sets ps1.  The code module uses sys.ps1 if present or sets it
     to “>>> “ if not.  Test_code_module now properly tests both
     behaviors.  Ditto for ps2.

   - bpo-28603(7): Fix a TypeError that caused a shell restart when
     printing a traceback that includes an exception that is unhashable.
     Patch by Zane Bitter.

   - bpo-13802(8): Use non-Latin characters in the IDLE’s Font settings
     sample.  Even if one selects a font that defines a limited subset
     of the unicode Basic Multilingual Plane, tcl/tk will use other
     fonts that define a character.  The expanded example give users of
     non-Latin characters a better idea of what they might see in IDLE’s
     shell and editors.  To make room for the expanded sample, frames on
     the Font tab are re-arranged.  The Font/Tabs help explains a bit
     about the additions.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32207

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32164

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32100

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31858

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31860

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31836

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28603

   (8) https://bugs.python.org/issue?@action=redirect&bpo=13802


File: python.info,  Node: Tools/Demos<42>,  Next: C API<61>,  Prev: IDLE<43>,  Up: Python 3 7 0 alpha 3

1.24.70.9 Tools/Demos
.....................

   - bpo-32159(1): Remove CVS and Subversion tools: remove svneol.py and
     treesync.py scripts.  CPython migrated from CVS to Subversion, to
     Mercurial, and then to Git.  CVS and Subversion are no longer used
     to develop CPython.

   - bpo-30722(2): Make redemo work with Python 3.6 and newer versions.
     Also, remove the ‘LOCALE’ option since it doesn’t work with string
     patterns in Python 3.  Patch by Christoph Sarnowski.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32159

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30722


File: python.info,  Node: C API<61>,  Prev: Tools/Demos<42>,  Up: Python 3 7 0 alpha 3

1.24.70.10 C API
................

   - bpo-20891(1): Fix PyGILState_Ensure().  When PyGILState_Ensure() is
     called in a non-Python thread before PyEval_InitThreads(), only
     call PyEval_InitThreads() after calling PyThreadState_New() to fix
     a crash.

   - bpo-32125(2): The ‘Py_UseClassExceptionsFlag’ flag has been
     removed.  It was deprecated and wasn’t used anymore since Python
     2.0.

   - bpo-25612(3): Move the current exception state from the frame
     object to the co-routine.  This simplifies the interpreter and
     fixes a couple of obscure bugs caused by having swap exception
     state when entering or exiting a generator.

   - bpo-23699(4): Add Py_RETURN_RICHCOMPARE macro to reduce boilerplate
     code in rich comparison functions.

   - bpo-30697(5): The ‘PyExc_RecursionErrorInst’ singleton is removed
     and ‘PyErr_NormalizeException()’ does not use it anymore.  This
     singleton is persistent and its members being never cleared may
     cause a segfault during finalization of the interpreter.  See also
     bpo-22898(6).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20891

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32125

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25612

   (4) https://bugs.python.org/issue?@action=redirect&bpo=23699

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30697

   (6) https://bugs.python.org/issue?@action=redirect&bpo=22898


File: python.info,  Node: Python 3 7 0 alpha 2,  Next: Python 3 7 0 alpha 1,  Prev: Python 3 7 0 alpha 3,  Up: Changelog

1.24.71 Python 3.7.0 alpha 2
----------------------------

'Release date: 2017-10-16'

* Menu:

* Core and Builtins: Core and Builtins<167>.
* Library: Library<171>.
* Documentation: Documentation<64>.
* Build: Build<69>.
* IDLE: IDLE<44>.
* C API: C API<62>.


File: python.info,  Node: Core and Builtins<167>,  Next: Library<171>,  Up: Python 3 7 0 alpha 2

1.24.71.1 Core and Builtins
...........................

   - bpo-31558(1): ‘gc.freeze()’ is a new API that allows for moving all
     objects currently tracked by the garbage collector to a permanent
     generation, effectively removing them from future collection
     events.  This can be used to protect those objects from having
     their PyGC_Head mutated.  In effect, this enables great
     copy-on-write stability at fork().

   - bpo-31642(2): Restored blocking «from package import module» by
     setting sys.modules[«package.module»] to None.

   - bpo-31708(3): Allow use of asynchronous generator expressions in
     synchronous functions.

   - bpo-31709(4): Drop support of asynchronous __aiter__.

   - bpo-30404(5): The -u option now makes the stdout and stderr streams
     unbuffered rather than line-buffered.

   - bpo-31619(6): Fixed a ValueError when convert a string with large
     number of underscores to integer with binary base.

   - bpo-31602(7): Fix an assertion failure in
     ‘zipimporter.get_source()’ in case of a bad ‘zlib.decompress()’.
     Patch by Oren Milman.

   - bpo-31592(8): Fixed an assertion failure in Python parser in case
     of a bad ‘unicodedata.normalize()’.  Patch by Oren Milman.

   - bpo-31588(9): Raise a ‘TypeError’ with a helpful error message when
     class creation fails due to a metaclass with a bad ‘__prepare__()’
     method.  Patch by Oren Milman.

   - bpo-31574(10): Importlib was instrumented with two dtrace probes to
     profile import timing.

   - bpo-31566(11): Fix an assertion failure in ‘_warnings.warn()’ in
     case of a bad ‘__name__’ global.  Patch by Oren Milman.

   - bpo-31506(12): Improved the error message logic for
     ‘object.__new__’ and ‘object.__init__’.

   - bpo-31505(13): Fix an assertion failure in ‘json’, in case
     ‘_json.make_encoder()’ received a bad ‘encoder()’ argument.  Patch
     by Oren Milman.

   - bpo-31492(14): Fix assertion failures in case of failing to import
     from a module with a bad ‘__name__’ attribute, and in case of
     failing to access an attribute of such a module.  Patch by Oren
     Milman.

   - bpo-31478(15): Fix an assertion failure in ‘_random.Random.seed()’
     in case the argument has a bad ‘__abs__()’ method.  Patch by Oren
     Milman.

   - bpo-31336(16): Speed up class creation by 10-20% by reducing the
     overhead in the necessary special method lookups.  Patch by Stefan
     Behnel.

   - bpo-31415(17): Add ‘-X importtime’ option to show how long each
     import takes.  It can be used to optimize application’s startup
     time.  Support the *note PYTHONPROFILEIMPORTTIME: cef. as an
     equivalent way to enable this.

   - bpo-31410(18): Optimized calling wrapper and classmethod
     descriptors.

   - bpo-31353(19): PEP 553(20) - Add a new built-in called
     ‘breakpoint()’ which calls ‘sys.breakpointhook()’.  By default this
     imports ‘pdb’ and calls ‘pdb.set_trace()’, but users may override
     ‘sys.breakpointhook()’ to call whatever debugger they want.  The
     original value of the hook is saved in ‘sys.__breakpointhook__’.

   - bpo-17852(21): Maintain a list of open buffered files, flush them
     before exiting the interpreter.  Based on a patch from Armin Rigo.

   - bpo-31315(22): Fix an assertion failure in imp.create_dynamic(),
     when spec.name is not a string.  Patch by Oren Milman.

   - bpo-31311(23): Fix a crash in the ‘__setstate__()’ method of
     ‘ctypes._CData’, in case of a bad ‘__dict__’.  Patch by Oren
     Milman.

   - bpo-31293(24): Fix crashes in true division and multiplication of a
     timedelta object by a float with a bad as_integer_ratio() method.
     Patch by Oren Milman.

   - bpo-31285(25): Fix an assertion failure in
     ‘warnings.warn_explicit’, when the return value of the received
     loader’s ‘get_source()’ has a bad ‘splitlines()’ method.  Patch by
     Oren Milman.

   - bpo-30406(26): Make ‘async’ and ‘await’ proper keywords, as
     specified in PEP 492(27).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31558

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31642

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31708

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31709

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30404

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31619

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31602

   (8) https://bugs.python.org/issue?@action=redirect&bpo=31592

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31588

   (10) https://bugs.python.org/issue?@action=redirect&bpo=31574

   (11) https://bugs.python.org/issue?@action=redirect&bpo=31566

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31506

   (13) https://bugs.python.org/issue?@action=redirect&bpo=31505

   (14) https://bugs.python.org/issue?@action=redirect&bpo=31492

   (15) https://bugs.python.org/issue?@action=redirect&bpo=31478

   (16) https://bugs.python.org/issue?@action=redirect&bpo=31336

   (17) https://bugs.python.org/issue?@action=redirect&bpo=31415

   (18) https://bugs.python.org/issue?@action=redirect&bpo=31410

   (19) https://bugs.python.org/issue?@action=redirect&bpo=31353

   (20) https://peps.python.org/pep-0553/

   (21) https://bugs.python.org/issue?@action=redirect&bpo=17852

   (22) https://bugs.python.org/issue?@action=redirect&bpo=31315

   (23) https://bugs.python.org/issue?@action=redirect&bpo=31311

   (24) https://bugs.python.org/issue?@action=redirect&bpo=31293

   (25) https://bugs.python.org/issue?@action=redirect&bpo=31285

   (26) https://bugs.python.org/issue?@action=redirect&bpo=30406

   (27) https://peps.python.org/pep-0492/


File: python.info,  Node: Library<171>,  Next: Documentation<64>,  Prev: Core and Builtins<167>,  Up: Python 3 7 0 alpha 2

1.24.71.2 Library
.................

   - bpo-30058(1): Fixed buffer overflow in select.kqueue.control().

   - bpo-31672(2): ‘idpattern’ in ‘string.Template’ matched some
     non-ASCII characters.  Now it uses ‘-i’ regular expression local
     flag to avoid non-ASCII characters.

   - bpo-31701(3): On Windows, faulthandler.enable() now ignores MSC and
     COM exceptions.

   - bpo-31728(4): Prevent crashes in ‘_elementtree’ due to unsafe
     cleanup of ‘Element.text’ and ‘Element.tail’.  Patch by Oren
     Milman.

   - bpo-31671(5): Now ‘re.compile()’ converts passed RegexFlag to
     normal int object before compiling.  bm_regex_compile benchmark
     shows 14% performance improvements.

   - bpo-30397(6): The types of compiled regular objects and match
     objects are now exposed as ‘re.Pattern’ and ‘re.Match’.  This adds
     information in pydoc output for the ‘re’ module.

   - bpo-31675(7): Fixed memory leaks in Tkinter’s methods splitlist()
     and split() when pass a string larger than 2 GiB.

   - bpo-31673(8): Fixed typo in the name of Tkinter’s method
     adderrorinfo().

   - bpo-31648(9): Improvements to path predicates in ElementTree: Allow
     whitespace around predicate parts, i.e.  «[a = “text”]» instead of
     requiring the less readable «[a=”text”]».  Add support for text
     comparison of the current node, like «[.=”text”]».  Patch by Stefan
     Behnel.

   - bpo-30806(10): Fix the string representation of a netrc object.

   - bpo-31638(11): Add optional argument ‘compressed’ to
     ‘zipapp.create_archive’, and add option ‘--compress’ to the command
     line interface of ‘zipapp’.

   - bpo-25351(12): Avoid venv activate failures with undefined
     variables

   - bpo-20519(13): Avoid ctypes use (if possible) and improve import
     time for uuid.

   - bpo-28293(14): The regular expression cache is no longer completely
     dumped when it is full.

   - bpo-31596(15): Added pthread_getcpuclockid() to the time module

   - bpo-27494(16): Make 2to3 accept a trailing comma in generator
     expressions.  For example, ‘set(x for x in [],)’ is now allowed.

   - bpo-30347(17): Stop crashes when concurrently iterate over
     itertools.groupby() iterators.

   - bpo-30346(18): An iterator produced by itertools.groupby() iterator
     now becomes exhausted after advancing the groupby iterator.

   - bpo-31556(19): Cancel asyncio.wait_for future faster if timeout <=
     0

   - bpo-31540(20): Allow passing a context object in *note
     concurrent.futures.ProcessPoolExecutor: 1d6. constructor.  Also,
     free job resources in *note concurrent.futures.ProcessPoolExecutor:
     1d6. earlier to improve memory usage when a worker waits for new
     jobs.

   - bpo-31516(21): ‘threading.current_thread()’ should not return a
     dummy thread at shutdown.

   - bpo-31525(22): In the sqlite module, require the sqlite3_prepare_v2
     API. Thus, the sqlite module now requires sqlite version at least
     3.3.9.

   - bpo-26510(23): argparse subparsers are now required by default.
     This matches behaviour in Python 2.  For optional subparsers, use
     the new parameter ‘add_subparsers(required=False)’.  Patch by
     Anthony Sottile.  (As of 3.7.0rc1, the default was changed to not
     required as had been the case since Python 3.3.)

   - bpo-27541(24): Reprs of subclasses of some collection and iterator
     classes (‘bytearray’, ‘array.array’, ‘collections.deque’,
     ‘collections.defaultdict’, ‘itertools.count’, ‘itertools.repeat’)
     now contain actual type name instead of hardcoded names of the base
     class.

   - bpo-31351(25): python -m ensurepip now exits with non-zero exit
     code if pip bootstrapping has failed.

   - bpo-31389(26): ‘pdb.set_trace()’ now takes an optional keyword-only
     argument ‘header’.  If given, this is printed to the console just
     before debugging begins.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30058

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31672

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31701

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31728

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31671

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30397

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31675

   (8) https://bugs.python.org/issue?@action=redirect&bpo=31673

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31648

   (10) https://bugs.python.org/issue?@action=redirect&bpo=30806

   (11) https://bugs.python.org/issue?@action=redirect&bpo=31638

   (12) https://bugs.python.org/issue?@action=redirect&bpo=25351

   (13) https://bugs.python.org/issue?@action=redirect&bpo=20519

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28293

   (15) https://bugs.python.org/issue?@action=redirect&bpo=31596

   (16) https://bugs.python.org/issue?@action=redirect&bpo=27494

   (17) https://bugs.python.org/issue?@action=redirect&bpo=30347

   (18) https://bugs.python.org/issue?@action=redirect&bpo=30346

   (19) https://bugs.python.org/issue?@action=redirect&bpo=31556

   (20) https://bugs.python.org/issue?@action=redirect&bpo=31540

   (21) https://bugs.python.org/issue?@action=redirect&bpo=31516

   (22) https://bugs.python.org/issue?@action=redirect&bpo=31525

   (23) https://bugs.python.org/issue?@action=redirect&bpo=26510

   (24) https://bugs.python.org/issue?@action=redirect&bpo=27541

   (25) https://bugs.python.org/issue?@action=redirect&bpo=31351

   (26) https://bugs.python.org/issue?@action=redirect&bpo=31389


File: python.info,  Node: Documentation<64>,  Next: Build<69>,  Prev: Library<171>,  Up: Python 3 7 0 alpha 2

1.24.71.3 Documentation
.......................

   - bpo-31537(1): Fix incorrect usage of ‘get_history_length’ in
     readline documentation example code.  Patch by Brad Smith.

   - bpo-30085(2): The operator functions without double underscores are
     preferred for clarity.  The one with underscores are only kept for
     back-compatibility.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31537

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30085


File: python.info,  Node: Build<69>,  Next: IDLE<44>,  Prev: Documentation<64>,  Up: Python 3 7 0 alpha 2

1.24.71.4 Build
...............

   - bpo-31696(1): Improve compiler version information in *note
     sys.version: 49d. when Python is built with Clang.

   - bpo-31625(2): Stop using ranlib on static libraries.  Instead, we
     assume ar supports the “s” flag.

   - bpo-31624(3): Remove support for BSD/OS.

   - bpo-22140(4): Prevent double substitution of prefix in
     python-config.sh.

   - bpo-31569(5): Correct PCBuild/ case to PCbuild/ in build scripts
     and documentation.

   - bpo-31536(6): Avoid wholesale rebuild after ‘make regen-all’ if
     nothing changed.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31696

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31625

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31624

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22140

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31569

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31536


File: python.info,  Node: IDLE<44>,  Next: C API<62>,  Prev: Build<69>,  Up: Python 3 7 0 alpha 2

1.24.71.5 IDLE
..............

   - bpo-31460(1): Simplify the API of IDLE’s Module Browser.  Passing a
     widget instead of an flist with a root widget opens the option of
     creating a browser frame that is only part of a window.  Passing a
     full file name instead of pieces assumed to come from a .py file
     opens the possibility of browsing python files that do not end in
     .py.

   - bpo-31649(2): IDLE - Make _htest, _utest parameters keyword only.

   - bpo-31559(3): Remove test order dependence in
     idle_test.test_browser.

   - bpo-31459(4): Rename IDLE’s module browser from Class Browser to
     Module Browser.  The original module-level class and method browser
     became a module browser, with the addition of module-level
     functions, years ago.  Nested classes and functions were added
     yesterday.  For back-compatibility, the virtual event
     <<open-class-browser>>, which appears on the Keys tab of the
     Settings dialog, is not changed.  Patch by Cheryl Sabella.

   - bpo-31500(5): Default fonts now are scaled on HiDPI displays.

   - bpo-1612262(6): IDLE module browser now shows nested classes and
     functions.  Original patches for code and tests by Guilherme Polo
     and Cheryl Sabella, respectively.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31460

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31649

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31559

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31459

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31500

   (6) https://bugs.python.org/issue?@action=redirect&bpo=1612262


File: python.info,  Node: C API<62>,  Prev: IDLE<44>,  Up: Python 3 7 0 alpha 2

1.24.71.6 C API
...............

   - bpo-28280(1): Make ‘PyMapping_Keys()’, ‘PyMapping_Values()’ and
     ‘PyMapping_Items()’ always return a ‘list’ (rather than a ‘list’ or
     a ‘tuple’).  Patch by Oren Milman.

   - bpo-31532(2): Fix memory corruption due to allocator mix in
     getpath.c between Py_GetPath() and Py_SetPath()

   - bpo-25658(3): Implement PEP 539(4) for Thread Specific Storage
     (TSS) API: it is a new Thread Local Storage (TLS) API to CPython
     which would supersede use of the existing TLS API within the
     CPython interpreter, while deprecating the existing API. PEP
     written by Erik M. Bray, patch by Masayuki Yamamoto.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28280

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31532

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25658

   (4) https://peps.python.org/pep-0539/


File: python.info,  Node: Python 3 7 0 alpha 1,  Next: Python 3 6 6 final,  Prev: Python 3 7 0 alpha 2,  Up: Changelog

1.24.72 Python 3.7.0 alpha 1
----------------------------

'Release date: 2017-09-19'

* Menu:

* Security: Security<49>.
* Core and Builtins: Core and Builtins<168>.
* Library: Library<172>.
* Documentation: Documentation<65>.
* Tests: Tests<62>.
* Build: Build<70>.
* Windows: Windows<62>.
* IDLE: IDLE<45>.
* Tools/Demos: Tools/Demos<43>.
* C API: C API<63>.


File: python.info,  Node: Security<49>,  Next: Core and Builtins<168>,  Up: Python 3 7 0 alpha 1

1.24.72.1 Security
..................

   - bpo-29781(1): SSLObject.version() now correctly returns None when
     handshake over BIO has not been performed yet.

   - bpo-29505(2): Add fuzz tests for float(str), int(str),
     unicode(str); for oss-fuzz.

   - bpo-30947(3): Upgrade libexpat embedded copy from version 2.2.1 to
     2.2.3 to get security fixes.

   - bpo-30730(4): Prevent environment variables injection in subprocess
     on Windows.  Prevent passing other environment variables and
     command arguments.

   - bpo-30694(5): Upgrade expat copy from 2.2.0 to 2.2.1 to get fixes
     of multiple security vulnerabilities including: CVE 2017-9233(6)
     (External entity infinite loop DoS), CVE 2016-9063(7) (Integer
     overflow, re-fix), CVE 2016-0718(8) (Fix regression bugs from
     2.2.0’s fix to CVE 2016-0718(9)) and CVE 2012-0876(10) (Counter
     hash flooding with SipHash).  Note: the CVE 2016-5300(11) (Use
     os-specific entropy sources like getrandom) doesn’t impact Python,
     since Python already gets entropy from the OS to set the expat
     secret using ‘XML_SetHashSalt()’.

   - bpo-30500(12): Fix urllib.parse.splithost() to correctly parse
     fragments.  For example, ‘splithost('//127.0.0.1#@evil.com/')’ now
     correctly returns the ‘127.0.0.1’ host, instead of treating
     ‘@evil.com’ as the host in an authentication (‘login@host’).

   - bpo-29591(13): Update expat copy from 2.1.1 to 2.2.0 to get fixes
     of CVE 2016-0718(14) and CVE 2016-4472(15).  See
     ‘https://sourceforge.net/p/expat/bugs/537/’ for more information.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29781

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29505

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30947

   (4) https://bugs.python.org/issue?@action=redirect&bpo=30730

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30694

   (6) https://www.cve.org/CVERecord?id=CVE-2017-9233

   (7) https://www.cve.org/CVERecord?id=CVE-2016-9063

   (8) https://www.cve.org/CVERecord?id=CVE-2016-0718

   (9) https://www.cve.org/CVERecord?id=CVE-2016-0718

   (10) https://www.cve.org/CVERecord?id=CVE-2012-0876

   (11) https://www.cve.org/CVERecord?id=CVE-2016-5300

   (12) https://bugs.python.org/issue?@action=redirect&bpo=30500

   (13) https://bugs.python.org/issue?@action=redirect&bpo=29591

   (14) https://www.cve.org/CVERecord?id=CVE-2016-0718

   (15) https://www.cve.org/CVERecord?id=CVE-2016-4472


File: python.info,  Node: Core and Builtins<168>,  Next: Library<172>,  Prev: Security<49>,  Up: Python 3 7 0 alpha 1

1.24.72.2 Core and Builtins
...........................

   - bpo-31490(1): Fix an assertion failure in ‘ctypes’ class
     definition, in case the class has an attribute whose name is
     specified in ‘_anonymous_’ but not in ‘_fields_’.  Patch by Oren
     Milman.

   - bpo-31471(2): Fix an assertion failure in ‘subprocess.Popen()’ on
     Windows, in case the env argument has a bad ‘keys()’ method.  Patch
     by Oren Milman.

   - bpo-31418(3): Fix an assertion failure in ‘PyErr_WriteUnraisable()’
     in case of an exception with a bad ‘__module__’ attribute.  Patch
     by Oren Milman.

   - bpo-31416(4): Fix assertion failures in case of a bad
     warnings.filters or warnings.defaultaction.  Patch by Oren Milman.

   - bpo-28411(5): Change direct usage of PyInterpreterState.modules to
     PyImport_GetModuleDict().  Also introduce more uniformity in other
     code that deals with sys.modules.  This helps reduce complications
     when working on sys.modules.

   - bpo-28411(6): Switch to the abstract API when dealing with
     ‘PyInterpreterState.modules’.  This allows later support for all
     dict subclasses and other Mapping implementations.  Also add a
     ‘PyImport_GetModule()’ function to reduce a bunch of duplicated
     code.

   - bpo-31411(7): Raise a TypeError instead of SystemError in case
     warnings.onceregistry is not a dictionary.  Patch by Oren Milman.

   - bpo-31344(8): For finer control of tracing behaviour when testing
     the interpreter, two new frame attributes have been added to
     control the emission of particular trace events: ‘f_trace_lines’
     (‘True’ by default) to turn off per-line trace events; and
     ‘f_trace_opcodes’ (‘False’ by default) to turn on per-opcode trace
     events.

   - bpo-31373(9): Fix several possible instances of undefined behavior
     due to floating-point demotions.

   - bpo-30465(10): Location information (‘lineno’ and ‘col_offset’) in
     f-strings is now (mostly) correct.  This fixes tools like flake8
     from showing warnings on the wrong line (typically the first line
     of the file).

   - bpo-30860(11): Consolidate CPython’s global runtime state under a
     single struct.  This improves discoverability of the runtime state.

   - bpo-31347(12): Fix possible undefined behavior in
     _PyObject_FastCall_Prepend.

   - bpo-31343(13): Include sys/sysmacros.h for major(), minor(), and
     makedev().  GNU C library plans to remove the functions from
     sys/types.h.

   - bpo-31291(14): Fix an assertion failure in
     ‘zipimport.zipimporter.get_data’ on Windows, when the return value
     of ‘pathname.replace('/','\\')’ isn’t a string.  Patch by Oren
     Milman.

   - bpo-31271(15): Fix an assertion failure in the ‘write()’ method of
     ‘io.TextIOWrapper’, when the encoder doesn’t return a bytes object.
     Patch by Oren Milman.

   - bpo-31243(16): Fix a crash in some methods of ‘io.TextIOWrapper’,
     when the decoder’s state is invalid.  Patch by Oren Milman.

   - bpo-30721(17): ‘print’ now shows correct usage hint for using
     Python 2 redirection syntax.  Patch by Sanyam Khurana.

   - bpo-31070(18): Fix a race condition in importlib
     _get_module_lock().

   - bpo-30747(19): Add a non-dummy implementation of _Py_atomic_store
     and _Py_atomic_load on MSVC.

   - bpo-31095(20): Fix potential crash during GC caused by ‘tp_dealloc’
     which doesn’t call ‘PyObject_GC_UnTrack()’.

   - bpo-31071(21): Avoid masking original TypeError in call with *
     unpacking when other arguments are passed.

   - bpo-30978(22): str.format_map() now passes key lookup exceptions
     through.  Previously any exception was replaced with a KeyError
     exception.

   - bpo-30808(23): Use _Py_atomic API for concurrency-sensitive signal
     state.

   - bpo-30876(24): Relative import from unloaded package now reimports
     the package instead of failing with SystemError.  Relative import
     from non-package now fails with ImportError rather than
     SystemError.

   - bpo-30703(25): Improve signal delivery.  Avoid using
     Py_AddPendingCall from signal handler, to avoid calling
     signal-unsafe functions.  The tests I’m adding here fail without
     the rest of the patch, on Linux and OS X. This means our signal
     delivery logic had defects (some signals could be lost).

   - bpo-30765(26): Avoid blocking in pthread_mutex_lock() when
     PyThread_acquire_lock() is asked not to block.

   - bpo-31161(27): Make sure the “Missing parentheses” syntax error
     message is only applied to SyntaxError, not to subclasses.  Patch
     by Martijn Pieters.

   - bpo-30814(28): Fixed a race condition when import a submodule from
     a package.

   - bpo-30736(29): The internal unicodedata database has been upgraded
     to Unicode 10.0.

   - bpo-30604(30): Move co_extra_freefuncs from per-thread to
     per-interpreter to avoid crashes.

   - bpo-30597(31): ‘print’ now shows expected input in custom error
     message when used as a Python 2 statement.  Patch by Sanyam
     Khurana.

   - bpo-30682(32): Removed a too-strict assertion that failed for
     certain f-strings, such as eval(«f”\n”») and eval(«f”\r”»).

   - bpo-30501(33): The compiler now produces more optimal code for
     complex condition expressions in the «if», «while» and «assert»
     statement, the «if» expression, and generator expressions and
     comprehensions.

   - bpo-28180(34): Implement PEP 538(35) (legacy C locale coercion).
     This means that when a suitable coercion target locale is
     available, both the core interpreter and locale-aware C extensions
     will assume the use of UTF-8 as the default text encoding, rather
     than ASCII.

   - bpo-30486(36): Allows setting cell values for __closure__.  Patch
     by Lisa Roach.

   - bpo-30537(37): itertools.islice now accepts integer-like objects
     (having an __index__ method) as start, stop, and slice arguments

   - bpo-25324(38): Tokens needed for parsing in Python moved to C.
     ‘COMMENT’, ‘NL’ and ‘ENCODING’.  This way the tokens and tok_names
     in the token module don’t get changed when you import the tokenize
     module.

   - bpo-29104(39): Fixed parsing backslashes in f-strings.

   - bpo-27945(40): Fixed various segfaults with dict when input
     collections are mutated during searching, inserting or comparing.
     Based on patches by Duane Griffin and Tim Mitchell.

   - bpo-25794(41): Fixed type.__setattr__() and type.__delattr__() for
     non-interned attribute names.  Based on patch by Eryk Sun.

   - bpo-30039(42): If a KeyboardInterrupt happens when the interpreter
     is in the middle of resuming a chain of nested “yield from” or
     “await” calls, it’s now correctly delivered to the innermost frame.

   - bpo-28974(43): ‘object.__format__(x, '')’ is now equivalent to
     ‘str(x)’ rather than ‘format(str(self), '')’.

   - bpo-30024(44): Circular imports involving absolute imports with
     binding a submodule to a name are now supported.

   - bpo-12414(45): sys.getsizeof() on a code object now returns the
     sizes which includes the code struct and sizes of objects which it
     references.  Patch by Donghee Na.

   - bpo-29839(46): len() now raises ValueError rather than
     OverflowError if __len__() returned a large negative integer.

   - bpo-11913(47): README.rst is now included in the list of distutils
     standard READMEs and therefore included in source distributions.

   - bpo-29914(48): Fixed default implementations of __reduce__ and
     __reduce_ex__().  object.__reduce__() no longer takes arguments,
     object.__reduce_ex__() now requires one argument.

   - bpo-29949(49): Fix memory usage regression of set and frozenset
     object.

   - bpo-29935(50): Fixed error messages in the index() method of tuple,
     list and deque when pass indices of wrong type.

   - bpo-29816(51): Shift operation now has less opportunity to raise
     OverflowError.  ValueError always is raised rather than
     OverflowError for negative counts.  Shifting zero with non-negative
     count always returns zero.

   - bpo-24821(52): Fixed the slowing down to 25 times in the searching
     of some unlucky Unicode characters.

   - bpo-29102(53): Add a unique ID to PyInterpreterState.  This makes
     it easier to identify each subinterpreter.

   - bpo-29894(54): The deprecation warning is emitted if __complex__
     returns an instance of a strict subclass of complex.  In a future
     versions of Python this can be an error.

   - bpo-29859(55): Show correct error messages when any of the
     pthread_* calls in thread_pthread.h fails.

   - bpo-29849(56): Fix a memory leak when an ImportError is raised
     during from import.

   - bpo-28856(57): Fix an oversight that %b format for bytes should
     support objects follow the buffer protocol.

   - bpo-29723(58): The ‘sys.path[0]’ initialization change for
     bpo-29139(59) caused a regression by revealing an inconsistency in
     how sys.path is initialized when executing ‘__main__’ from a
     zipfile, directory, or other import location.  The interpreter now
     consistently avoids ever adding the import location’s parent
     directory to ‘sys.path’, and ensures no other ‘sys.path’ entries
     are inadvertently modified when inserting the import location named
     on the command line.

   - bpo-29568(60): Escaped percent «%%» in the format string for
     classic string formatting no longer allows any characters between
     two percents.

   - bpo-29714(61): Fix a regression that bytes format may fail when
     containing zero bytes inside.

   - bpo-29695(62): bool(), float(), list() and tuple() no longer take
     keyword arguments.  The first argument of int() can now be passes
     only as positional argument.

   - bpo-28893(63): Set correct __cause__ for errors about invalid
     awaitables returned from __aiter__ and __anext__.

   - bpo-28876(64): ‘bool(range)’ works even if ‘len(range)’ raises
     *note OverflowError: a83.

   - bpo-29683(65): Fixes to memory allocation in _PyCode_SetExtra.
     Patch by Brian Coleman.

   - bpo-29684(66): Fix minor regression of
     PyEval_CallObjectWithKeywords.  It should raise TypeError when
     kwargs is not a dict.  But it might cause segv when args=NULL and
     kwargs is not a dict.

   - bpo-28598(67): Support __rmod__ for subclasses of str being called
     before str.__mod__.  Patch by Martijn Pieters.

   - bpo-29607(68): Fix stack_effect computation for CALL_FUNCTION_EX.
     Patch by Matthieu Dartiailh.

   - bpo-29602(69): Fix incorrect handling of signed zeros in complex
     constructor for complex subclasses and for inputs having a
     __complex__ method.  Patch by Serhiy Storchaka.

   - bpo-29347(70): Fixed possibly dereferencing undefined pointers when
     creating weakref objects.

   - bpo-29463(71): Add ‘docstring’ field to Module, ClassDef,
     FunctionDef, and AsyncFunctionDef ast nodes.  docstring is not
     first stmt in their body anymore.  It affects ‘co_firstlineno’ and
     ‘co_lnotab’ of code object for module and class.  (Reverted in
     bpo-32911(72).)

   - bpo-29438(73): Fixed use-after-free problem in key sharing dict.

   - bpo-29546(74): Set the “path” and “name” attribute on ImportError
     for ‘from ... import ...’.

   - bpo-29546(75): Improve from-import error message with location

   - bpo-29478(76): If max_line_length=None is specified while using the
     Compat32 policy, it is no longer ignored.  Patch by Mircea Cosbuc.

   - bpo-29319(77): Prevent RunMainFromImporter overwriting sys.path[0].

   - bpo-29337(78): Fixed possible BytesWarning when compare the code
     objects.  Warnings could be emitted at compile time.

   - bpo-29327(79): Fixed a crash when pass the iterable keyword
     argument to sorted().

   - bpo-29034(80): Fix memory leak and use-after-free in os module
     (path_converter).

   - bpo-29159(81): Fix regression in bytes(x) when x.__index__() raises
     Exception.

   - bpo-29049(82): Call _PyObject_GC_TRACK() lazily when calling Python
     function.  Calling function is up to 5% faster.

   - bpo-28927(83): bytes.fromhex() and bytearray.fromhex() now ignore
     all ASCII whitespace, not only spaces.  Patch by Robert Xiao.

   - bpo-28932(84): Do not include <sys/random.h> if it does not exist.

   - bpo-25677(85): Correct the positioning of the syntax error caret
     for indented blocks.  Based on patch by Michael Layzell.

   - bpo-29000(86): Fixed bytes formatting of octals with zero padding
     in alternate form.

   - bpo-18896(87): Python function can now have more than 255
     parameters.  collections.namedtuple() now supports tuples with more
     than 255 elements.

   - bpo-28596(88): The preferred encoding is UTF-8 on Android.  Patch
     written by Chi Hsuan Yen.

   - bpo-22257(89): Clean up interpreter startup (see PEP 432(90)).

   - bpo-26919(91): On Android, operating system data is now always
     encoded/decoded to/from UTF-8, instead of the locale encoding to
     avoid inconsistencies with os.fsencode() and os.fsdecode() which
     are already using UTF-8.

   - bpo-28991(92): functools.lru_cache() was susceptible to an obscure
     reentrancy bug triggerable by a monkey-patched len() function.

   - bpo-28147(93): Fix a memory leak in split-table dictionaries:
     setattr() must not convert combined table into split table.  Patch
     written by INADA Naoki.

   - bpo-28739(94): f-string expressions are no longer accepted as
     docstrings and by ast.literal_eval() even if they do not include
     expressions.

   - bpo-28512(95): Fixed setting the offset attribute of SyntaxError by
     PyErr_SyntaxLocationEx() and PyErr_SyntaxLocationObject().

   - bpo-28918(96): Fix the cross compilation of xxlimited when Python
     has been built with Py_DEBUG defined.

   - bpo-23722(97): Rather than silently producing a class that doesn’t
     support zero-argument ‘super()’ in methods, failing to pass the new
     ‘__classcell__’ namespace entry up to ‘type.__new__’ now results in
     a ‘DeprecationWarning’ and a class that supports zero-argument
     ‘super()’.

   - bpo-28797(98): Modifying the class __dict__ inside the __set_name__
     method of a descriptor that is used inside that class no longer
     prevents calling the __set_name__ method of other descriptors.

   - bpo-28799(99): Remove the ‘PyEval_GetCallStats()’ function and
     deprecate the untested and undocumented ‘sys.callstats()’ function.
     Remove the ‘CALL_PROFILE’ special build: use the *note
     sys.setprofile(): 1705. function, *note cProfile: 2b. or *note
     profile: b4. to profile function calls.

   - bpo-12844(100): More than 255 arguments can now be passed to a
     function.

   - bpo-28782(101): Fix a bug in the implementation ‘yield from’ when
     checking if the next instruction is YIELD_FROM. Regression
     introduced by WORDCODE (bpo-26647(102)).

   - bpo-28774(103): Fix error position of the unicode error in ASCII
     and Latin1 encoders when a string returned by the error handler
     contains multiple non-encodable characters (non-ASCII for the ASCII
     codec, characters out of the U+0000-U+00FF range for Latin1).

   - bpo-28731(104): Optimize _PyDict_NewPresized() to create correct
     size dict.  Improve speed of dict literal with constant keys up to
     30%.

   - bpo-28532(105): Show sys.version when -V option is supplied twice.

   - bpo-27100(106): The with-statement now checks for __enter__ before
     it checks for __exit__.  This gives less confusing error messages
     when both methods are missing.  Patch by Jonathan Ellington.

   - bpo-28746(107): Fix the set_inheritable() file descriptor method on
     platforms that do not have the ioctl FIOCLEX and FIONCLEX commands.

   - bpo-26920(108): Fix not getting the locale’s charset upon
     initializing the interpreter, on platforms that do not have
     langinfo.

   - bpo-28648(109): Fixed crash in Py_DecodeLocale() in debug build on
     Mac OS X when decode astral characters.  Patch by Xiang Zhang.

   - bpo-28665(110): Improve speed of the STORE_DEREF opcode by 40%.

   - bpo-19398(111): Extra slash no longer added to sys.path components
     in case of empty compile-time PYTHONPATH components.

   - bpo-28621(112): Sped up converting int to float by reusing faster
     bits counting implementation.  Patch by Adrian Wielgosik.

   - bpo-28580(113): Optimize iterating split table values.  Patch by
     Xiang Zhang.

   - bpo-28583(114): PyDict_SetDefault didn’t combine split table when
     needed.  Patch by Xiang Zhang.

   - bpo-28128(115): Deprecation warning for invalid str and byte escape
     sequences now prints better information about where the error
     occurs.  Patch by Serhiy Storchaka and Eric Smith.

   - bpo-28509(116): dict.update() no longer allocate unnecessary large
     memory.

   - bpo-28426(117): Fixed potential crash in
     PyUnicode_AsDecodedObject() in debug build.

   - bpo-28517(118): Fixed of-by-one error in the peephole optimizer
     that caused keeping unreachable code.

   - bpo-28214(119): Improved exception reporting for problematic
     __set_name__ attributes.

   - bpo-23782(120): Fixed possible memory leak in _PyTraceback_Add()
     and exception loss in PyTraceBack_Here().

   - bpo-28183(121): Optimize and cleanup dict iteration.

   - bpo-26081(122): Added C implementation of asyncio.Future.  Original
     patch by Yury Selivanov.

   - bpo-28379(123): Added sanity checks and tests for
     PyUnicode_CopyCharacters().  Patch by Xiang Zhang.

   - bpo-28376(124): The type of long range iterator is now registered
     as Iterator.  Patch by Oren Milman.

   - bpo-28376(125): Creating instances of range_iterator by calling
     range_iterator type now is disallowed.  Calling iter() on range
     instance is the only way.  Patch by Oren Milman.

   - bpo-26906(126): Resolving special methods of uninitialized type now
     causes implicit initialization of the type instead of a fail.

   - bpo-18287(127): PyType_Ready() now checks that tp_name is not NULL.
     Original patch by Niklas Koep.

   - bpo-24098(128): Fixed possible crash when AST is changed in process
     of compiling it.

   - bpo-28201(129): Dict reduces possibility of 2nd conflict in hash
     table when hashes have same lower bits.

   - bpo-28350(130): String constants with null character no longer
     interned.

   - bpo-26617(131): Fix crash when GC runs during weakref callbacks.

   - bpo-27942(132): String constants now interned recursively in tuples
     and frozensets.

   - bpo-28289(133): ImportError.__init__ now resets not specified
     attributes.

   - bpo-21578(134): Fixed misleading error message when ImportError
     called with invalid keyword args.

   - bpo-28203(135): Fix incorrect type in complex(1.0, {2:3}) error
     message.  Patch by Soumya Sharma.

   - bpo-28086(136): Single var-positional argument of tuple subtype was
     passed unscathed to the C-defined function.  Now it is converted to
     exact tuple.

   - bpo-28214(137): Now __set_name__ is looked up on the class instead
     of the instance.

   - bpo-27955(138): Fallback on reading /dev/urandom device when the
     getrandom() syscall fails with EPERM, for example when blocked by
     SECCOMP.

   - bpo-28192(139): Don’t import readline in isolated mode.

   - bpo-27441(140): Remove some redundant assignments to ob_size in
     longobject.c.  Thanks Oren Milman.

   - bpo-27222(141): Clean up redundant code in long_rshift function.
     Thanks Oren Milman.

   - Upgrade internal unicode databases to Unicode version 9.0.0.

   - bpo-28131(142): Fix a regression in zipimport’s compile_source().
     zipimport should use the same optimization level as the
     interpreter.

   - bpo-28126(143): Replace Py_MEMCPY with memcpy().  Visual Studio can
     properly optimize memcpy().

   - bpo-28120(144): Fix dict.pop() for split dictionary when trying to
     remove a «pending key» (Not yet inserted in split-table).  Patch by
     Xiang Zhang.

   - bpo-26182(145): Raise DeprecationWarning when async and await
     keywords are used as variable/attribute/class/function name.

   - bpo-26182(146): Fix a refleak in code that raises
     DeprecationWarning.

   - bpo-28721(147): Fix asynchronous generators aclose() and athrow()
     to handle StopAsyncIteration propagation properly.

   - bpo-26110(148): Speed-up method calls: add LOAD_METHOD and
     CALL_METHOD opcodes.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31490

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31471

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31418

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31416

   (5) https://bugs.python.org/issue?@action=redirect&bpo=28411

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28411

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31411

   (8) https://bugs.python.org/issue?@action=redirect&bpo=31344

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31373

   (10) https://bugs.python.org/issue?@action=redirect&bpo=30465

   (11) https://bugs.python.org/issue?@action=redirect&bpo=30860

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31347

   (13) https://bugs.python.org/issue?@action=redirect&bpo=31343

   (14) https://bugs.python.org/issue?@action=redirect&bpo=31291

   (15) https://bugs.python.org/issue?@action=redirect&bpo=31271

   (16) https://bugs.python.org/issue?@action=redirect&bpo=31243

   (17) https://bugs.python.org/issue?@action=redirect&bpo=30721

   (18) https://bugs.python.org/issue?@action=redirect&bpo=31070

   (19) https://bugs.python.org/issue?@action=redirect&bpo=30747

   (20) https://bugs.python.org/issue?@action=redirect&bpo=31095

   (21) https://bugs.python.org/issue?@action=redirect&bpo=31071

   (22) https://bugs.python.org/issue?@action=redirect&bpo=30978

   (23) https://bugs.python.org/issue?@action=redirect&bpo=30808

   (24) https://bugs.python.org/issue?@action=redirect&bpo=30876

   (25) https://bugs.python.org/issue?@action=redirect&bpo=30703

   (26) https://bugs.python.org/issue?@action=redirect&bpo=30765

   (27) https://bugs.python.org/issue?@action=redirect&bpo=31161

   (28) https://bugs.python.org/issue?@action=redirect&bpo=30814

   (29) https://bugs.python.org/issue?@action=redirect&bpo=30736

   (30) https://bugs.python.org/issue?@action=redirect&bpo=30604

   (31) https://bugs.python.org/issue?@action=redirect&bpo=30597

   (32) https://bugs.python.org/issue?@action=redirect&bpo=30682

   (33) https://bugs.python.org/issue?@action=redirect&bpo=30501

   (34) https://bugs.python.org/issue?@action=redirect&bpo=28180

   (35) https://peps.python.org/pep-0538/

   (36) https://bugs.python.org/issue?@action=redirect&bpo=30486

   (37) https://bugs.python.org/issue?@action=redirect&bpo=30537

   (38) https://bugs.python.org/issue?@action=redirect&bpo=25324

   (39) https://bugs.python.org/issue?@action=redirect&bpo=29104

   (40) https://bugs.python.org/issue?@action=redirect&bpo=27945

   (41) https://bugs.python.org/issue?@action=redirect&bpo=25794

   (42) https://bugs.python.org/issue?@action=redirect&bpo=30039

   (43) https://bugs.python.org/issue?@action=redirect&bpo=28974

   (44) https://bugs.python.org/issue?@action=redirect&bpo=30024

   (45) https://bugs.python.org/issue?@action=redirect&bpo=12414

   (46) https://bugs.python.org/issue?@action=redirect&bpo=29839

   (47) https://bugs.python.org/issue?@action=redirect&bpo=11913

   (48) https://bugs.python.org/issue?@action=redirect&bpo=29914

   (49) https://bugs.python.org/issue?@action=redirect&bpo=29949

   (50) https://bugs.python.org/issue?@action=redirect&bpo=29935

   (51) https://bugs.python.org/issue?@action=redirect&bpo=29816

   (52) https://bugs.python.org/issue?@action=redirect&bpo=24821

   (53) https://bugs.python.org/issue?@action=redirect&bpo=29102

   (54) https://bugs.python.org/issue?@action=redirect&bpo=29894

   (55) https://bugs.python.org/issue?@action=redirect&bpo=29859

   (56) https://bugs.python.org/issue?@action=redirect&bpo=29849

   (57) https://bugs.python.org/issue?@action=redirect&bpo=28856

   (58) https://bugs.python.org/issue?@action=redirect&bpo=29723

   (59) https://bugs.python.org/issue?@action=redirect&bpo=29139

   (60) https://bugs.python.org/issue?@action=redirect&bpo=29568

   (61) https://bugs.python.org/issue?@action=redirect&bpo=29714

   (62) https://bugs.python.org/issue?@action=redirect&bpo=29695

   (63) https://bugs.python.org/issue?@action=redirect&bpo=28893

   (64) https://bugs.python.org/issue?@action=redirect&bpo=28876

   (65) https://bugs.python.org/issue?@action=redirect&bpo=29683

   (66) https://bugs.python.org/issue?@action=redirect&bpo=29684

   (67) https://bugs.python.org/issue?@action=redirect&bpo=28598

   (68) https://bugs.python.org/issue?@action=redirect&bpo=29607

   (69) https://bugs.python.org/issue?@action=redirect&bpo=29602

   (70) https://bugs.python.org/issue?@action=redirect&bpo=29347

   (71) https://bugs.python.org/issue?@action=redirect&bpo=29463

   (72) https://bugs.python.org/issue?@action=redirect&bpo=32911

   (73) https://bugs.python.org/issue?@action=redirect&bpo=29438

   (74) https://bugs.python.org/issue?@action=redirect&bpo=29546

   (75) https://bugs.python.org/issue?@action=redirect&bpo=29546

   (76) https://bugs.python.org/issue?@action=redirect&bpo=29478

   (77) https://bugs.python.org/issue?@action=redirect&bpo=29319

   (78) https://bugs.python.org/issue?@action=redirect&bpo=29337

   (79) https://bugs.python.org/issue?@action=redirect&bpo=29327

   (80) https://bugs.python.org/issue?@action=redirect&bpo=29034

   (81) https://bugs.python.org/issue?@action=redirect&bpo=29159

   (82) https://bugs.python.org/issue?@action=redirect&bpo=29049

   (83) https://bugs.python.org/issue?@action=redirect&bpo=28927

   (84) https://bugs.python.org/issue?@action=redirect&bpo=28932

   (85) https://bugs.python.org/issue?@action=redirect&bpo=25677

   (86) https://bugs.python.org/issue?@action=redirect&bpo=29000

   (87) https://bugs.python.org/issue?@action=redirect&bpo=18896

   (88) https://bugs.python.org/issue?@action=redirect&bpo=28596

   (89) https://bugs.python.org/issue?@action=redirect&bpo=22257

   (90) https://peps.python.org/pep-0432/

   (91) https://bugs.python.org/issue?@action=redirect&bpo=26919

   (92) https://bugs.python.org/issue?@action=redirect&bpo=28991

   (93) https://bugs.python.org/issue?@action=redirect&bpo=28147

   (94) https://bugs.python.org/issue?@action=redirect&bpo=28739

   (95) https://bugs.python.org/issue?@action=redirect&bpo=28512

   (96) https://bugs.python.org/issue?@action=redirect&bpo=28918

   (97) https://bugs.python.org/issue?@action=redirect&bpo=23722

   (98) https://bugs.python.org/issue?@action=redirect&bpo=28797

   (99) https://bugs.python.org/issue?@action=redirect&bpo=28799

   (100) https://bugs.python.org/issue?@action=redirect&bpo=12844

   (101) https://bugs.python.org/issue?@action=redirect&bpo=28782

   (102) https://bugs.python.org/issue?@action=redirect&bpo=26647

   (103) https://bugs.python.org/issue?@action=redirect&bpo=28774

   (104) https://bugs.python.org/issue?@action=redirect&bpo=28731

   (105) https://bugs.python.org/issue?@action=redirect&bpo=28532

   (106) https://bugs.python.org/issue?@action=redirect&bpo=27100

   (107) https://bugs.python.org/issue?@action=redirect&bpo=28746

   (108) https://bugs.python.org/issue?@action=redirect&bpo=26920

   (109) https://bugs.python.org/issue?@action=redirect&bpo=28648

   (110) https://bugs.python.org/issue?@action=redirect&bpo=28665

   (111) https://bugs.python.org/issue?@action=redirect&bpo=19398

   (112) https://bugs.python.org/issue?@action=redirect&bpo=28621

   (113) https://bugs.python.org/issue?@action=redirect&bpo=28580

   (114) https://bugs.python.org/issue?@action=redirect&bpo=28583

   (115) https://bugs.python.org/issue?@action=redirect&bpo=28128

   (116) https://bugs.python.org/issue?@action=redirect&bpo=28509

   (117) https://bugs.python.org/issue?@action=redirect&bpo=28426

   (118) https://bugs.python.org/issue?@action=redirect&bpo=28517

   (119) https://bugs.python.org/issue?@action=redirect&bpo=28214

   (120) https://bugs.python.org/issue?@action=redirect&bpo=23782

   (121) https://bugs.python.org/issue?@action=redirect&bpo=28183

   (122) https://bugs.python.org/issue?@action=redirect&bpo=26081

   (123) https://bugs.python.org/issue?@action=redirect&bpo=28379

   (124) https://bugs.python.org/issue?@action=redirect&bpo=28376

   (125) https://bugs.python.org/issue?@action=redirect&bpo=28376

   (126) https://bugs.python.org/issue?@action=redirect&bpo=26906

   (127) https://bugs.python.org/issue?@action=redirect&bpo=18287

   (128) https://bugs.python.org/issue?@action=redirect&bpo=24098

   (129) https://bugs.python.org/issue?@action=redirect&bpo=28201

   (130) https://bugs.python.org/issue?@action=redirect&bpo=28350

   (131) https://bugs.python.org/issue?@action=redirect&bpo=26617

   (132) https://bugs.python.org/issue?@action=redirect&bpo=27942

   (133) https://bugs.python.org/issue?@action=redirect&bpo=28289

   (134) https://bugs.python.org/issue?@action=redirect&bpo=21578

   (135) https://bugs.python.org/issue?@action=redirect&bpo=28203

   (136) https://bugs.python.org/issue?@action=redirect&bpo=28086

   (137) https://bugs.python.org/issue?@action=redirect&bpo=28214

   (138) https://bugs.python.org/issue?@action=redirect&bpo=27955

   (139) https://bugs.python.org/issue?@action=redirect&bpo=28192

   (140) https://bugs.python.org/issue?@action=redirect&bpo=27441

   (141) https://bugs.python.org/issue?@action=redirect&bpo=27222

   (142) https://bugs.python.org/issue?@action=redirect&bpo=28131

   (143) https://bugs.python.org/issue?@action=redirect&bpo=28126

   (144) https://bugs.python.org/issue?@action=redirect&bpo=28120

   (145) https://bugs.python.org/issue?@action=redirect&bpo=26182

   (146) https://bugs.python.org/issue?@action=redirect&bpo=26182

   (147) https://bugs.python.org/issue?@action=redirect&bpo=28721

   (148) https://bugs.python.org/issue?@action=redirect&bpo=26110


File: python.info,  Node: Library<172>,  Next: Documentation<65>,  Prev: Core and Builtins<168>,  Up: Python 3 7 0 alpha 1

1.24.72.3 Library
.................

   - bpo-31499(1): xml.etree: Fix a crash when a parser is part of a
     reference cycle.

   - bpo-31482(2): ‘random.seed()’ now works with bytes in version=1

   - bpo-28556(3): typing.get_type_hints now finds the right globalns
     for classes and modules by default (when no ‘globalns’ was
     specified by the caller).

   - bpo-28556(4): Speed improvements to the ‘typing’ module.  Original
     PRs by Ivan Levkivskyi and Mitar.

   - bpo-31544(5): The C accelerator module of ElementTree ignored
     exceptions raised when looking up TreeBuilder target methods in
     XMLParser().

   - bpo-31234(6): socket.create_connection() now fixes manually a
     reference cycle: clear the variable storing the last exception on
     success.

   - bpo-31457(7): LoggerAdapter objects can now be nested.

   - bpo-31431(8): SSLContext.check_hostname now automatically sets
     SSLContext.verify_mode to ssl.CERT_REQUIRED instead of failing with
     a ValueError.

   - bpo-31233(9): socketserver.ThreadingMixIn now keeps a list of
     non-daemonic threads to wait until all these threads complete in
     server_close().

   - bpo-28638(10): Changed the implementation strategy for
     collections.namedtuple() to substantially reduce the use of exec()
     in favor of precomputed methods.  As a result, the 'verbose'
     parameter and '_source' attribute are no longer supported.  The
     benefits include 1) having a smaller memory footprint for
     applications using multiple named tuples, 2) faster creation of the
     named tuple class (approx 4x to 6x depending on how it is
     measured), and 3) minor speed-ups for instance creation using
     __new__, _make, and _replace.  (The primary patch contributor is
     Jelle Zijlstra with further improvements by INADA Naoki, Serhiy
     Storchaka, and Raymond Hettinger.)

   - bpo-31400(11): Improves SSL error handling to avoid losing error
     numbers.

   - bpo-27629(12): Make return types of SSLContext.wrap_bio() and
     SSLContext.wrap_socket() customizable.

   - bpo-28958(13): ssl.SSLContext() now uses OpenSSL error information
     when a context cannot be instantiated.

   - bpo-28182(14): The SSL module now raises SSLCertVerificationError
     when OpenSSL fails to verify the peer’s certificate.  The exception
     contains more information about the error.

   - bpo-27340(15): SSLSocket.sendall() now uses memoryview to create
     slices of data.  This fixes support for all bytes-like object.  It
     is also more efficient and avoids costly copies.

   - bpo-14191(16): A new function
     ‘argparse.ArgumentParser.parse_intermixed_args’ provides the
     ability to parse command lines where there user intermixes options
     and positional arguments.

   - bpo-31178(17): Fix string concatenation bug in rare error path in
     the subprocess module

   - bpo-31350(18): Micro-optimize ‘asyncio._get_running_loop()’ to
     become up to 10% faster.

   - bpo-31170(19): expat: Update libexpat from 2.2.3 to 2.2.4.  Fix
     copying of partial characters for UTF-8 input (libexpat bug 115):
     ‘https://github.com/libexpat/libexpat/issues/115’

   - bpo-29136(20): Add TLS 1.3 cipher suites and OP_NO_TLSv1_3.

   - bpo-1198569(21): ‘string.Template’ subclasses can optionally define
     ‘braceidpattern’ if they want to specify different placeholder
     patterns inside and outside the braces.  If None (the default) it
     falls back to ‘idpattern’.

   - bpo-31326(22): concurrent.futures.ProcessPoolExecutor.shutdown()
     now explicitly closes the call queue.  Moreover,
     shutdown(wait=True) now also join the call queue thread, to prevent
     leaking a dangling thread.

   - bpo-27144(23): The ‘map()’ and ‘as_completed()’ iterators in
     ‘concurrent.futures’ now avoid keeping a reference to yielded
     objects.

   - bpo-31281(24): Fix ‘fileinput.FileInput(files, inplace=True)’ when
     ‘files’ contain ‘pathlib.Path’ objects.

   - bpo-10746(25): Fix ctypes producing wrong PEP 3118(26) type codes
     for integer types.

   - bpo-27584(27): ‘AF_VSOCK’ has been added to the socket interface
     which allows communication between virtual machines and their host.

   - bpo-22536(28): The subprocess module now sets the filename when
     FileNotFoundError is raised on POSIX systems due to the executable
     or cwd not being found.

   - bpo-29741(29): Update some methods in the _pyio module to also
     accept integer types.  Patch by Oren Milman.

   - bpo-31249(30): concurrent.futures: WorkItem.run() used by
     ThreadPoolExecutor now breaks a reference cycle between an
     exception object and the WorkItem object.

   - bpo-31247(31): xmlrpc.server now explicitly breaks reference cycles
     when using sys.exc_info() in code handling exceptions.

   - bpo-23835(32): configparser: reading defaults in the
     ‘ConfigParser()’ constructor is now using ‘read_dict()’, making its
     behavior consistent with the rest of the parser.  Non-string keys
     and values in the defaults dictionary are now being implicitly
     converted to strings.  Patch by James Tocknell.

   - bpo-31238(33): pydoc: the stop() method of the private ServerThread
     class now waits until DocServer.serve_until_quit() completes and
     then explicitly sets its docserver attribute to None to break a
     reference cycle.

   - bpo-5001(34): Many asserts in ‘multiprocessing’ are now more
     informative, and some error types have been changed to more
     specific ones.

   - bpo-31109(35): Convert zipimport to use Argument Clinic.

   - bpo-30102(36): The ssl and hashlib modules now call
     OPENSSL_add_all_algorithms_noconf() on OpenSSL < 1.1.0.  The
     function detects CPU features and enables optimizations on some CPU
     architectures such as POWER8.  Patch is based on research from
     Gustavo Serra Scalet.

   - bpo-18966(37): Non-daemonic threads created by a
     multiprocessing.Process are now joined on child exit.

   - bpo-31183(38): ‘dis’ now works with asynchronous generator and
     coroutine objects.  Patch by George Collins based on diagnosis by
     Luciano Ramalho.

   - bpo-5001(39): There are a number of uninformative asserts in the
     ‘multiprocessing’ module, as noted in issue 5001.  This change
     fixes two of the most potentially problematic ones, since they are
     in error-reporting code, in the
     ‘multiprocessing.managers.convert_to_error’ function.  (It also
     makes more informative a ValueError message.)  The only potentially
     problematic change is that the AssertionError is now a TypeError;
     however, this should also help distinguish it from an
     AssertionError being 'reported' by the function/its caller (such as
     in issue 31169).  - Patch by Allen W. Smith (drallensmith on
     github).

   - bpo-31185(40): Fixed miscellaneous errors in asyncio speedup
     module.

   - bpo-31151(41): socketserver.ForkingMixIn.server_close() now waits
     until all child processes completed to prevent leaking zombie
     processes.

   - bpo-31072(42): Add an ‘include_file’ parameter to
     ‘zipapp.create_archive()’

   - bpo-24700(43): Optimize array.array comparison.  It is now from 10x
     up to 70x faster when comparing arrays holding values of the same
     integer type.

   - bpo-31135(44): ttk: fix the destroy() method of LabeledScale and
     OptionMenu classes.  Call the parent destroy() method even if the
     used attribute doesn’t exist.  The LabeledScale.destroy() method
     now also explicitly clears label and scale attributes to help the
     garbage collector to destroy all widgets.

   - bpo-31107(45): Fix ‘copyreg._slotnames()’ mangled attribute
     calculation for classes whose name begins with an underscore.
     Patch by Shane Harvey.

   - bpo-31080(46): Allow ‘logging.config.fileConfig’ to accept kwargs
     and/or args.

   - bpo-30897(47): ‘pathlib.Path’ objects now include an ‘is_mount()’
     method (only implemented on POSIX). This is similar to
     ‘os.path.ismount(p)’.  Patch by Cooper Ry Lees.

   - bpo-31061(48): Fixed a crash when using asyncio and threads.

   - bpo-30987(49): Added support for CAN ISO-TP protocol in the socket
     module.

   - bpo-30522(50): Added a ‘setStream’ method to
     ‘logging.StreamHandler’ to allow the stream to be set after
     creation.

   - bpo-30502(51): Fix handling of long oids in ssl.  Based on patch by
     Christian Heimes.

   - bpo-5288(52): Support tzinfo objects with sub-minute offsets.

   - bpo-30919(53): Fix shared memory performance regression in
     multiprocessing in 3.x.  Shared memory used anonymous memory
     mappings in 2.x, while 3.x mmaps actual files.  Try to be careful
     to do as little disk I/O as possible.

   - bpo-26732(54): Fix too many fds in processes started with the
     «forkserver» method.  A child process would inherit as many fds as
     the number of still-running children.

   - bpo-29403(55): Fix ‘unittest.mock’’s autospec to not fail on
     method-bound builtin functions.  Patch by Aaron Gallagher.

   - bpo-30961(56): Fix decrementing a borrowed reference in
     tracemalloc.

   - bpo-19896(57): Fix multiprocessing.sharedctypes to recognize
     typecodes ‘'q'’ and ‘'Q'’.

   - bpo-30946(58): Remove obsolete code in readline module for
     platforms where GNU readline is older than 2.1 or where select() is
     not available.

   - bpo-25684(59): Change ‘ttk.OptionMenu’ radiobuttons to be unique
     across instances of ‘OptionMenu’.

   - bpo-30886(60): Fix multiprocessing.Queue.join_thread(): it now
     waits until the thread completes, even if the thread was started by
     the same process which created the queue.

   - bpo-29854(61): Fix segfault in readline when using readline’s
     history-size option.  Patch by Nir Soffer.

   - bpo-30794(62): Added multiprocessing.Process.kill method to
     terminate using the SIGKILL signal on Unix.

   - bpo-30319(63): socket.close() now ignores ECONNRESET error.

   - bpo-30828(64): Fix out of bounds write in
     ‘asyncio.CFuture.remove_done_callback()’.

   - bpo-30302(65): Use keywords in the ‘repr’ of ‘datetime.timedelta’.

   - bpo-30807(66): signal.setitimer() may disable the timer when passed
     a tiny value.  Tiny values (such as 1e-6) are valid non-zero values
     for setitimer(), which is specified as taking
     microsecond-resolution intervals.  However, on some platform, our
     conversion routine could convert 1e-6 into a zero interval,
     therefore disabling the timer instead of (re-)scheduling it.

   - bpo-30441(67): Fix bug when modifying os.environ while iterating
     over it

   - bpo-29585(68): Avoid importing ‘sysconfig’ from ‘site’ to improve
     startup speed.  Python startup is about 5% faster on Linux and 30%
     faster on macOS.

   - bpo-29293(69): Add missing parameter «n» on
     multiprocessing.Condition.notify().  The doc claims
     multiprocessing.Condition behaves like threading.Condition, but its
     notify() method lacked the optional «n» argument (to specify the
     number of sleepers to wake up) that threading.Condition.notify()
     accepts.

   - bpo-30532(70): Fix email header value parser dropping folding white
     space in certain cases.

   - bpo-30596(71): Add a ‘close()’ method to ‘multiprocessing.Process’.

   - bpo-9146(72): Fix a segmentation fault in _hashopenssl when
     standard hash functions such as md5 are not available in the linked
     OpenSSL library.  As in some special FIPS-140 build environments.

   - bpo-29169(73): Update zlib to 1.2.11.

   - bpo-30119(74): ftplib.FTP.putline() now throws ValueError on
     commands that contains CR or LF. Patch by Donghee Na.

   - bpo-30879(75): os.listdir() and os.scandir() now emit bytes names
     when called with bytes-like argument.

   - bpo-30746(76): Prohibited the “=” character in environment variable
     names in ‘os.putenv()’ and ‘os.spawn*()’.

   - bpo-30664(77): The description of a unittest subtest now preserves
     the order of keyword arguments of TestCase.subTest().

   - bpo-21071(78): struct.Struct.format type is now *note str: 169.
     instead of *note bytes: 192.

   - bpo-29212(79): Fix concurrent.futures.thread.ThreadPoolExecutor
     threads to have a non repr() based thread name by default when no
     thread_name_prefix is supplied.  They will now identify themselves
     as «ThreadPoolExecutor-y_n».

   - bpo-29755(80): Fixed the lgettext() family of functions in the
     gettext module.  They now always return bytes.

   - bpo-30616(81): Functional API of enum allows to create empty enums.
     Patched by Donghee Na

   - bpo-30038(82): Fix race condition between signal delivery and
     wakeup file descriptor.  Patch by Nathaniel Smith.

   - bpo-23894(83): lib2to3 now recognizes ‘rb'...'’ and ‘f'...'’
     strings.

   - bpo-24744(84): pkgutil.walk_packages function now raises ValueError
     if 'path' is a string.  Patch by Sanyam Khurana.

   - bpo-24484(85): Avoid race condition in multiprocessing cleanup.

   - bpo-30589(86): Fix multiprocessing.Process.exitcode to return the
     opposite of the signal number when the process is killed by a
     signal (instead of 255) when using the «forkserver» method.

   - bpo-28994(87): The traceback no longer displayed for SystemExit
     raised in a callback registered by atexit.

   - bpo-30508(88): Don’t log exceptions if Task/Future «cancel()»
     method was called.

   - bpo-30645(89): Fix path calculation in ‘imp.load_package()’, fixing
     it for cases when a package is only shipped with bytecodes.  Patch
     by Alexandru Ardelean.

   - bpo-11822(90): The dis.dis() function now is able to disassemble
     nested code objects.

   - bpo-30624(91): selectors does not take KeyboardInterrupt and
     SystemExit into account, leaving a fd in a bad state in case of
     error.  Patch by Giampaolo Rodola”.

   - bpo-30595(92): multiprocessing.Queue.get() with a timeout now polls
     its reader in non-blocking mode if it succeeded to acquire the lock
     but the acquire took longer than the timeout.

   - bpo-28556(93): Updates to typing module: Add generic
     AsyncContextManager, add support for ContextManager on all
     versions.  Original PRs by Jelle Zijlstra and Ivan Levkivskyi

   - bpo-30605(94): re.compile() no longer raises a BytesWarning when
     compiling a bytes instance with misplaced inline modifier.  Patch
     by Roy Williams.

   - bpo-29870(95): Fix ssl sockets leaks when connection is aborted in
     asyncio/ssl implementation.  Patch by Michaël Sghaïer.

   - bpo-29743(96): Closing transport during handshake process leaks
     open socket.  Patch by Nikolay Kim

   - bpo-27585(97): Fix waiter cancellation in asyncio.Lock.  Patch by
     Mathieu Sornay.

   - bpo-30014(98): modify() method of poll(), epoll() and devpoll()
     based classes of selectors module is around 10% faster.  Patch by
     Giampaolo Rodola”.

   - bpo-30418(99): On Windows, subprocess.Popen.communicate() now also
     ignore EINVAL on stdin.write() if the child process is still
     running but closed the pipe.

   - bpo-30463(100): Added empty __slots__ to abc.ABC. This allows
     subclassers to deny __dict__ and __weakref__ creation.  Patch by
     Aaron Hall.

   - bpo-30520(101): Loggers are now pickleable.

   - bpo-30557(102): faulthandler now correctly filters and displays
     exception codes on Windows

   - bpo-30526(103): Add TextIOWrapper.reconfigure() and a
     TextIOWrapper.write_through attribute.

   - bpo-30245(104): Fix possible overflow when organize
     struct.pack_into error message.  Patch by Yuan Liu.

   - bpo-30378(105): Fix the problem that logging.handlers.SysLogHandler
     cannot handle IPv6 addresses.

   - bpo-16500(106): Allow registering at-fork handlers.

   - bpo-30470(107): Deprecate invalid ctypes call protection on
     Windows.  Patch by Mariatta Wijaya.

   - bpo-30414(108): multiprocessing.Queue._feed background running
     thread do not break from main loop on exception.

   - bpo-30003(109): Fix handling escape characters in HZ codec.  Based
     on patch by Ma Lin.

   - bpo-30149(110): inspect.signature() now supports callables with
     variable-argument parameters wrapped with partialmethod.  Patch by
     Donghee Na.

   - bpo-30436(111): importlib.find_spec() raises ModuleNotFoundError
     instead of AttributeError if the specified parent module is not a
     package (i.e.  lacks a __path__ attribute).

   - bpo-30301(112): Fix AttributeError when using SimpleQueue.empty()
     under 'spawn' and 'forkserver' start methods.

   - bpo-30375(113): Warnings emitted when compile a regular expression
     now always point to the line in the user code.  Previously they
     could point into inners of the re module if emitted from inside of
     groups or conditionals.

   - bpo-30329(114): imaplib and poplib now catch the Windows socket
     WSAEINVAL error (code 10022) on shutdown(SHUT_RDWR): An invalid
     operation was attempted.  This error occurs sometimes on SSL
     connections.

   - bpo-29196(115): Removed previously deprecated in Python 2.4 classes
     Plist, Dict and _InternalDict in the plistlib module.  Dict values
     in the result of functions readPlist() and readPlistFromBytes() are
     now normal dicts.  You no longer can use attribute access to access
     items of these dictionaries.

   - bpo-9850(116): The ‘macpath’ is now deprecated and will be removed
     in Python 3.8.

   - bpo-30299(117): Compiling regular expression in debug mode on
     CPython now displays the compiled bytecode in human readable form.

   - bpo-30048(118): Fixed ‘Task.cancel()’ can be ignored when the task
     is running coroutine and the coroutine returned without any more
     ‘await’.

   - bpo-30266(119): contextlib.AbstractContextManager now supports
     anti-registration by setting __enter__ = None or __exit__ = None,
     following the pattern introduced in bpo-25958(120).  Patch by Jelle
     Zijlstra.

   - bpo-30340(121): Enhanced regular expressions optimization.  This
     increased the performance of matching some patterns up to 25 times.

   - bpo-30298(122): Weaken the condition of deprecation warnings for
     inline modifiers.  Now allowed several subsequential inline
     modifiers at the start of the pattern (e.g.  ‘'(?i)(?s)...'’).  In
     verbose mode whitespaces and comments now are allowed before and
     between inline modifiers (e.g.  ‘'(?x) (?i) (?s)...'’).

   - bpo-30285(123): Optimized case-insensitive matching and searching
     of regular expressions.

   - bpo-29990(124): Fix range checking in GB18030 decoder.  Original
     patch by Ma Lin.

   - bpo-29979(125): rewrite cgi.parse_multipart, reusing the
     FieldStorage class and making its results consistent with those of
     FieldStorage for multipart/form-data requests.  Patch by Pierre
     Quentel.

   - bpo-30243(126): Removed the __init__ methods of _json’s scanner and
     encoder.  Misusing them could cause memory leaks or crashes.  Now
     scanner and encoder objects are completely initialized in the
     __new__ methods.

   - bpo-30215(127): Compiled regular expression objects with the
     re.LOCALE flag no longer depend on the locale at compile time.
     Only the locale at matching time affects the result of matching.

   - bpo-30185(128): Avoid KeyboardInterrupt tracebacks in forkserver
     helper process when Ctrl-C is received.

   - bpo-30103(129): binascii.b2a_uu() and uu.encode() now support using
     ‘'`'’ as zero instead of space.

   - bpo-28556(130): Various updates to typing module: add
     typing.NoReturn type, use WrapperDescriptorType, minor bug-fixes.
     Original PRs by Jim Fasarakis-Hilliard and Ivan Levkivskyi.

   - bpo-30205(131): Fix getsockname() for unbound AF_UNIX sockets on
     Linux.

   - bpo-30228(132): The seek() and tell() methods of io.FileIO now set
     the internal seekable attribute to avoid one syscall on open() (in
     buffered or text mode).

   - bpo-30190(133): unittest’s assertAlmostEqual and
     assertNotAlmostEqual provide a better message in case of failure
     which includes the difference between left and right arguments.
     (patch by Giampaolo Rodola”)

   - bpo-30101(134): Add support for curses.A_ITALIC.

   - bpo-29822(135): inspect.isabstract() now works during
     __init_subclass__.  Patch by Nate Soares.

   - bpo-29960(136): Preserve generator state when
     _random.Random.setstate() raises an exception.  Patch by Bryan
     Olson.

   - bpo-30070(137): Fixed leaks and crashes in errors handling in the
     parser module.

   - bpo-22352(138): Column widths in the output of dis.dis() are now
     adjusted for large line numbers and instruction offsets.

   - bpo-30061(139): Fixed crashes in IOBase methods __next__() and
     readlines() when readline() or __next__() respectively return
     non-sizeable object.  Fixed possible other errors caused by not
     checking results of PyObject_Size(), PySequence_Size(), or
     PyMapping_Size().

   - bpo-30218(140): Fix PathLike support for shutil.unpack_archive.
     Patch by Jelle Zijlstra.

   - bpo-10076(141): Compiled regular expression and match objects in
     the re module now support copy.copy() and copy.deepcopy() (they are
     considered atomic).

   - bpo-30068(142): _io._IOBase.readlines will check if it’s closed
     first when hint is present.

   - bpo-29694(143): Fixed race condition in pathlib mkdir with flags
     parents=True.  Patch by Armin Rigo.

   - bpo-29692(144): Fixed arbitrary unchaining of RuntimeError
     exceptions in contextlib.contextmanager.  Patch by Siddharth
     Velankar.

   - bpo-26187(145): Test that sqlite3 trace callback is not called
     multiple times when schema is changing.  Indirectly fixed by
     switching to use sqlite3_prepare_v2() in bpo-9303(146).  Patch by
     Aviv Palivoda.

   - bpo-30017(147): Allowed calling the close() method of the zip entry
     writer object multiple times.  Writing to a closed writer now
     always produces a ValueError.

   - bpo-29998(148): Pickling and copying ImportError now preserves name
     and path attributes.

   - bpo-29995(149): re.escape() now escapes only regex special
     characters.

   - bpo-29962(150): Add math.remainder operation, implementing
     remainder as specified in IEEE 754.

   - bpo-29649(151): Improve struct.pack_into() exception messages for
     problems with the buffer size and offset.  Patch by Andrew Nester.

   - bpo-29654(152): Support If-Modified-Since HTTP header (browser
     cache).  Patch by Pierre Quentel.

   - bpo-29931(153): Fixed comparison check for ipaddress.ip_interface
     objects.  Patch by Sanjay Sundaresan.

   - bpo-29953(154): Fixed memory leaks in the replace() method of
     datetime and time objects when pass out of bound fold argument.

   - bpo-29942(155): Fix a crash in itertools.chain.from_iterable when
     encountering long runs of empty iterables.

   - bpo-10030(156): Sped up reading encrypted ZIP files by 2 times.

   - bpo-29204(157): Element.getiterator() and the html parameter of
     XMLParser() were deprecated only in the documentation (since Python
     3.2 and 3.4 correspondingly).  Now using them emits a deprecation
     warning.

   - bpo-27863(158): Fixed multiple crashes in ElementTree caused by
     race conditions and wrong types.

   - bpo-25996(159): Added support of file descriptors in os.scandir()
     on Unix.  os.fwalk() is sped up by 2 times by using os.scandir().

   - bpo-28699(160): Fixed a bug in pools in multiprocessing.pool that
     raising an exception at the very first of an iterable may swallow
     the exception or make the program hang.  Patch by Davin Potts and
     Xiang Zhang.

   - bpo-23890(161): unittest.TestCase.assertRaises() now manually
     breaks a reference cycle to not keep objects alive longer than
     expected.

   - bpo-29901(162): The zipapp module now supports general path-like
     objects, not just pathlib.Path.

   - bpo-25803(163): Avoid incorrect errors raised by
     Path.mkdir(exist_ok=True) when the OS gives priority to errors such
     as EACCES over EEXIST.

   - bpo-29861(164): Release references to tasks, their arguments and
     their results as soon as they are finished in multiprocessing.Pool.

   - bpo-19930(165): The mode argument of os.makedirs() no longer
     affects the file permission bits of newly created
     intermediate-level directories.

   - bpo-29884(166): faulthandler: Restore the old sigaltstack during
     teardown.  Patch by Christophe Zeitouny.

   - bpo-25455(167): Fixed crashes in repr of recursive buffered
     file-like objects.

   - bpo-29800(168): Fix crashes in partial.__repr__ if the keys of
     partial.keywords are not strings.  Patch by Michael Seifert.

   - bpo-8256(169): Fixed possible failing or crashing input() if
     attributes «encoding» or «errors» of sys.stdin or sys.stdout are
     not set or are not strings.

   - bpo-28692(170): Using non-integer value for selecting a plural form
     in gettext is now deprecated.

   - bpo-26121(171): Use C library implementation for math functions
     erf() and erfc().

   - bpo-29619(172): os.stat() and os.DirEntry.inode() now convert inode
     (st_ino) using unsigned integers.

   - bpo-28298(173): Fix a bug that prevented array “Q”, “L” and “I”
     from accepting big intables (objects that have __int__) as
     elements.

   - bpo-29645(174): Speed up importing the webbrowser module.
     webbrowser.register() is now thread-safe.

   - bpo-28231(175): The zipfile module now accepts path-like objects
     for external paths.

   - bpo-26915(176): index() and count() methods of
     collections.abc.Sequence now check identity before checking
     equality when do comparisons.

   - bpo-28682(177): Added support for bytes paths in os.fwalk().

   - bpo-29728(178): Add new ‘socket.TCP_NOTSENT_LOWAT’ (Linux 3.12)
     constant.  Patch by Nathaniel J. Smith.

   - bpo-29623(179): Allow use of path-like object as a single argument
     in ConfigParser.read().  Patch by David Ellis.

   - bpo-9303(180): Migrate sqlite3 module to _v2 API. Patch by Aviv
     Palivoda.

   - bpo-28963(181): Fix out of bound iteration in
     asyncio.Future.remove_done_callback implemented in C.

   - bpo-29704(182): asyncio.subprocess.SubprocessStreamProtocol no
     longer closes before all pipes are closed.

   - bpo-29271(183): Fix Task.current_task and Task.all_tasks
     implemented in C to accept None argument as their pure Python
     implementation.

   - bpo-29703(184): Fix asyncio to support instantiation of new event
     loops in child processes.

   - bpo-29615(185): SimpleXMLRPCDispatcher no longer chains KeyError
     (or any other exception) to exception(s) raised in the dispatched
     methods.  Patch by Petr Motejlek.

   - bpo-7769(186): Method register_function() of
     xmlrpc.server.SimpleXMLRPCDispatcher and its subclasses can now be
     used as a decorator.

   - bpo-29376(187): Fix assertion error in
     threading._DummyThread.is_alive().

   - bpo-28624(188): Add a test that checks that cwd parameter of
     Popen() accepts PathLike objects.  Patch by Sayan Chowdhury.

   - bpo-28518(189): Start a transaction implicitly before a DML
     statement.  Patch by Aviv Palivoda.

   - bpo-29742(190): get_extra_info() raises exception if get called on
     closed ssl transport.  Patch by Nikolay Kim.

   - bpo-16285(191): urllib.parse.quote is now based on RFC 3986 and
     hence includes “~” in the set of characters that is not quoted by
     default.  Patch by Christian Theune and Ratnadeep Debnath.

   - bpo-29532(192): Altering a kwarg dictionary passed to
     functools.partial() no longer affects a partial object after
     creation.

   - bpo-29110(193): Fix file object leak in aifc.open() when file is
     given as a filesystem path and is not in valid AIFF format.  Patch
     by Anthony Zhang.

   - bpo-22807(194): Add uuid.SafeUUID and uuid.UUID.is_safe to relay
     information from the platform about whether generated UUIDs are
     generated with a multiprocessing safe method.

   - bpo-29576(195): Improve some deprecations in importlib.  Some
     deprecated methods now emit DeprecationWarnings and have better
     descriptive messages.

   - bpo-29534(196): Fixed different behaviour of Decimal.from_float()
     for _decimal and _pydecimal.  Thanks Andrew Nester.

   - bpo-10379(197): locale.format_string now supports the “monetary”
     keyword argument, and locale.format is deprecated.

   - bpo-29851(198): importlib.reload() now raises ModuleNotFoundError
     if the module lacks a spec.

   - bpo-28556(199): Various updates to typing module: typing.Counter,
     typing.ChainMap, improved ABC caching, etc.  Original PRs by Jelle
     Zijlstra, Ivan Levkivskyi, Manuel Krebber, and Łukasz Langa.

   - bpo-29100(200): Fix datetime.fromtimestamp() regression introduced
     in Python 3.6.0: check minimum and maximum years.

   - bpo-29416(201): Prevent infinite loop in pathlib.Path.mkdir

   - bpo-29444(202): Fixed out-of-bounds buffer access in the group()
     method of the match object.  Based on patch by WGH.

   - bpo-29377(203): Add WrapperDescriptorType, MethodWrapperType, and
     MethodDescriptorType built-in types to types module.  Original
     patch by Manuel Krebber.

   - bpo-29218(204): Unused install_misc command is now removed.  It has
     been documented as unused since 2000.  Patch by Eric N. Vander
     Weele.

   - bpo-29368(205): The extend() method is now called instead of the
     append() method when unpickle collections.deque and other list-like
     objects.  This can speed up unpickling to 2 times.

   - bpo-29338(206): The help of a builtin or extension class now
     includes the constructor signature if __text_signature__ is
     provided for the class.

   - bpo-29335(207): Fix subprocess.Popen.wait() when the child process
     has exited to a stopped instead of terminated state (ex: when under
     ptrace).

   - bpo-29290(208): Fix a regression in argparse that help messages
     would wrap at non-breaking spaces.

   - bpo-28735(209): Fixed the comparison of mock.MagickMock with
     mock.ANY.

   - bpo-29197(210): Removed deprecated function ntpath.splitunc().

   - bpo-29210(211): Removed support of deprecated argument «exclude» in
     tarfile.TarFile.add().

   - bpo-29219(212): Fixed infinite recursion in the repr of
     uninitialized ctypes.CDLL instances.

   - bpo-29192(213): Removed deprecated features in the http.cookies
     module.

   - bpo-29193(214): A format string argument for
     string.Formatter.format() is now positional-only.

   - bpo-29195(215): Removed support of deprecated undocumented keyword
     arguments in methods of regular expression objects.

   - bpo-28969(216): Fixed race condition in C implementation of
     functools.lru_cache.  KeyError could be raised when cached function
     with full cache was simultaneously called from different threads
     with the same uncached arguments.

   - bpo-20804(217): The unittest.mock.sentinel attributes now preserve
     their identity when they are copied or pickled.

   - bpo-29142(218): In urllib.request, suffixes in no_proxy environment
     variable with leading dots could match related hostnames again
     (e.g.  .b.c matches a.b.c).  Patch by Milan Oberkirch.

   - bpo-28961(219): Fix unittest.mock._Call helper: don’t ignore the
     name parameter anymore.  Patch written by Jiajun Huang.

   - bpo-15812(220): inspect.getframeinfo() now correctly shows the
     first line of a context.  Patch by Sam Breese.

   - bpo-28985(221): Update authorizer constants in sqlite3 module.
     Patch by Dingyuan Wang.

   - bpo-29079(222): Prevent infinite loop in pathlib.resolve() on
     Windows

   - bpo-13051(223): Fixed recursion errors in large or resized
     curses.textpad.Textbox.  Based on patch by Tycho Andersen.

   - bpo-9770(224): curses.ascii predicates now work correctly with
     negative integers.

   - bpo-28427(225): old keys should not remove new values from
     WeakValueDictionary when collecting from another thread.

   - bpo-28923(226): Remove editor artifacts from Tix.py.

   - bpo-28871(227): Fixed a crash when deallocate deep ElementTree.

   - bpo-19542(228): Fix bugs in WeakValueDictionary.setdefault() and
     WeakValueDictionary.pop() when a GC collection happens in another
     thread.

   - bpo-20191(229): Fixed a crash in resource.prlimit() when passing a
     sequence that doesn’t own its elements as limits.

   - bpo-16255(230): subprocess.Popen uses /system/bin/sh on Android as
     the shell, instead of /bin/sh.

   - bpo-28779(231): multiprocessing.set_forkserver_preload() would
     crash the forkserver process if a preloaded module instantiated
     some multiprocessing objects such as locks.

   - bpo-26937(232): The chown() method of the tarfile.TarFile class
     does not fail now when the grp module cannot be imported, as for
     example on Android platforms.

   - bpo-28847(233): dbm.dumb now supports reading read-only files and
     no longer writes the index file when it is not changed.  A
     deprecation warning is now emitted if the index file is missed and
     recreated in the “r” and “w” modes (will be an error in future
     Python releases).

   - bpo-27030(234): Unknown escapes consisting of ‘'\'’ and an ASCII
     letter in re.sub() replacement templates regular expressions now
     are errors.

   - bpo-28835(235): Fix a regression introduced in
     warnings.catch_warnings(): call warnings.showwarning() if it was
     overridden inside the context manager.

   - bpo-27172(236): To assist with upgrades from 2.7, the previously
     documented deprecation of ‘inspect.getfullargspec()’ has been
     reversed.  This decision may be revisited again after the Python
     2.7 branch is no longer officially supported.

   - bpo-28740(237): Add sys.getandroidapilevel(): return the build time
     API version of Android as an integer.  Function only available on
     Android.

   - bpo-26273(238): Add new ‘socket.TCP_CONGESTION’ (Linux 2.6.13) and
     ‘socket.TCP_USER_TIMEOUT’ (Linux 2.6.37) constants.  Patch written
     by Omar Sandoval.

   - bpo-28752(239): Restored the __reduce__() methods of datetime
     objects.

   - bpo-28727(240): Regular expression patterns, _sre.SRE_Pattern
     objects created by re.compile(), become comparable (only x==y and
     x!=y operators).  This change should fix the bpo-18383(241): don’t
     duplicate warning filters when the warnings module is reloaded
     (thing usually only done in unit tests).

   - bpo-20572(242): Remove the subprocess.Popen.wait endtime parameter.
     It was deprecated in 3.4 and undocumented prior to that.

   - bpo-25659(243): In ctypes, prevent a crash calling the
     from_buffer() and from_buffer_copy() methods on abstract classes
     like Array.

   - bpo-28548(244): In the «http.server» module, parse the protocol
     version if possible, to avoid using HTTP 0.9 in some error
     responses.

   - bpo-19717(245): Makes Path.resolve() succeed on paths that do not
     exist.  Patch by Vajrasky Kok

   - bpo-28563(246): Fixed possible DoS and arbitrary code execution
     when handle plural form selections in the gettext module.  The
     expression parser now supports exact syntax supported by GNU
     gettext.

   - bpo-28387(247): Fixed possible crash in _io.TextIOWrapper
     deallocator when the garbage collector is invoked in other thread.
     Based on patch by Sebastian Cufre.

   - bpo-27517(248): LZMA compressor and decompressor no longer raise
     exceptions if given empty data twice.  Patch by Benjamin Fogle.

   - bpo-28549(249): Fixed segfault in curses’s addch() with ncurses6.

   - bpo-28449(250): tarfile.open() with mode «r» or «r:» now tries to
     open a tar file with compression before trying to open it without
     compression.  Otherwise it had 50% chance failed with
     ignore_zeros=True.

   - bpo-23262(251): The webbrowser module now supports Firefox 36+ and
     derived browsers.  Based on patch by Oleg Broytman.

   - bpo-24241(252): The webbrowser in an X environment now prefers
     using the default browser directly.  Also, the webbrowser
     register() function now has a documented “preferred” argument, to
     specify browsers to be returned by get() with no arguments.  Patch
     by David Steele

   - bpo-27939(253): Fixed bugs in tkinter.ttk.LabeledScale and
     tkinter.Scale caused by representing the scale as float value
     internally in Tk.  tkinter.IntVar now works if float value is set
     to underlying Tk variable.

   - bpo-28255(254): calendar.TextCalendar.prweek() no longer prints a
     space after a weeks’s calendar.  calendar.TextCalendar.pryear() no
     longer prints redundant newline after a year’s calendar.  Based on
     patch by Xiang Zhang.

   - bpo-28255(255): calendar.TextCalendar.prmonth() no longer prints a
     space at the start of new line after printing a month’s calendar.
     Patch by Xiang Zhang.

   - bpo-20491(256): The textwrap.TextWrapper class now honors
     non-breaking spaces.  Based on patch by Kaarle Ritvanen.

   - bpo-28353(257): os.fwalk() no longer fails on broken links.

   - bpo-28430(258): Fix iterator of C implemented asyncio.Future
     doesn’t accept non-None value is passed to it.send(val).

   - bpo-27025(259): Generated names for Tkinter widgets now start by
     the «!» prefix for readability.

   - bpo-25464(260): Fixed HList.header_exists() in tkinter.tix module
     by addin a workaround to Tix library bug.

   - bpo-28488(261): shutil.make_archive() no longer adds entry «./» to
     ZIP archive.

   - bpo-25953(262): re.sub() now raises an error for invalid numerical
     group reference in replacement template even if the pattern is not
     found in the string.  Error message for invalid group reference now
     includes the group index and the position of the reference.  Based
     on patch by SilentGhost.

   - bpo-28469(263): timeit now uses the sequence 1, 2, 5, 10, 20, 50,…
     instead of 1, 10, 100,… for autoranging.

   - bpo-28115(264): Command-line interface of the zipfile module now
     uses argparse.  Added support of long options.

   - bpo-18219(265): Optimize csv.DictWriter for large number of
     columns.  Patch by Mariatta Wijaya.

   - bpo-28448(266): Fix C implemented asyncio.Future didn’t work on
     Windows.

   - bpo-23214(267): In the «io» module, the argument to BufferedReader
     and BytesIO’s read1() methods is now optional and can be -1,
     matching the BufferedIOBase specification.

   - bpo-28480(268): Fix error building socket module when
     multithreading is disabled.

   - bpo-28240(269): timeit: remove ‘-c/--clock’ and ‘-t/--time’ command
     line options which were deprecated since Python 3.3.

   - bpo-28240(270): timeit now repeats the benchmarks 5 times instead
     of only 3 to make benchmarks more reliable.

   - bpo-28240(271): timeit autorange now uses a single loop iteration
     if the benchmark takes less than 10 seconds, instead of 10
     iterations.  «python3 -m timeit -s “import time” “time.sleep(1)”»
     now takes 4 seconds instead of 40 seconds.

   - Distutils.sdist now looks for README and setup.py files with case
     sensitivity.  This behavior matches that found in Setuptools 6.0
     and later.  See setuptools 100(272) for rationale.

   - bpo-24452(273): Make webbrowser support Chrome on Mac OS X. Patch
     by Ned Batchelder.

   - bpo-20766(274): Fix references leaked by pdb in the handling of
     SIGINT handlers.

   - bpo-27998(275): Fixed bytes path support in os.scandir() on
     Windows.  Patch by Eryk Sun.

   - bpo-28317(276): The disassembler now decodes FORMAT_VALUE argument.

   - bpo-28380(277): unittest.mock Mock autospec functions now properly
     support assert_called, assert_not_called, and assert_called_once.

   - bpo-28229(278): lzma module now supports pathlib.

   - bpo-28321(279): Fixed writing non-BMP characters with binary format
     in plistlib.

   - bpo-28225(280): bz2 module now supports pathlib.  Initial patch by
     Ethan Furman.

   - bpo-28227(281): gzip now supports pathlib.  Patch by Ethan Furman.

   - bpo-28332(282): Deprecated silent truncations in socket.htons and
     socket.ntohs.  Original patch by Oren Milman.

   - bpo-27358(283): Optimized merging var-keyword arguments and
     improved error message when passing a non-mapping as a var-keyword
     argument.

   - bpo-28257(284): Improved error message when passing a non-iterable
     as a var-positional argument.  Added opcode
     BUILD_TUPLE_UNPACK_WITH_CALL.

   - bpo-28322(285): Fixed possible crashes when unpickle itertools
     objects from incorrect pickle data.  Based on patch by John Leitch.

   - bpo-28228(286): imghdr now supports pathlib.

   - bpo-28226(287): compileall now supports pathlib.

   - bpo-28314(288): Fix function declaration (C flags) for the
     getiterator() method of xml.etree.ElementTree.Element.

   - bpo-28148(289): Stop using localtime() and gmtime() in the time
     module.  Introduced platform independent _PyTime_localtime API that
     is similar to POSIX localtime_r, but available on all platforms.
     Patch by Ed Schouten.

   - bpo-28253(290): Fixed calendar functions for extreme months:
     0001-01 and 9999-12.  Methods itermonthdays() and itermonthdays2()
     are reimplemented so that they don’t call itermonthdates() which
     can cause datetime.date under/overflow.

   - bpo-28275(291): Fixed possible use after free in the decompress()
     methods of the LZMADecompressor and BZ2Decompressor classes.
     Original patch by John Leitch.

   - bpo-27897(292): Fixed possible crash in
     sqlite3.Connection.create_collation() if pass invalid string-like
     object as a name.  Patch by Xiang Zhang.

   - bpo-18844(293): random.choices() now has k as a keyword-only
     argument to improve the readability of common cases and come into
     line with the signature used in other languages.

   - bpo-18893(294): Fix invalid exception handling in
     Lib/ctypes/macholib/dyld.py.  Patch by Madison May.

   - bpo-27611(295): Fixed support of default root window in the
     tkinter.tix module.  Added the master parameter in the DisplayStyle
     constructor.

   - bpo-27348(296): In the traceback module, restore the formatting of
     exception messages like «Exception: None».  This fixes a regression
     introduced in 3.5a2.

   - bpo-25651(297): Allow false values to be used for msg parameter of
     subTest().

   - bpo-27778(298): Fix a memory leak in os.getrandom() when the
     getrandom() is interrupted by a signal and a signal handler raises
     a Python exception.

   - bpo-28200(299): Fix memory leak on Windows in the os module (fix
     path_converter() function).

   - bpo-25400(300): RobotFileParser now correctly returns default
     values for crawl_delay and request_rate.  Initial patch by Peter
     Wirtz.

   - bpo-27932(301): Prevent memory leak in win32_ver().

   - Fix UnboundLocalError in socket._sendfile_use_sendfile.

   - bpo-28075(302): Check for ERROR_ACCESS_DENIED in Windows
     implementation of os.stat().  Patch by Eryk Sun.

   - bpo-22493(303): Warning message emitted by using inline flags in
     the middle of regular expression now contains a (truncated) regex
     pattern.  Patch by Tim Graham.

   - bpo-25270(304): Prevent codecs.escape_encode() from raising
     SystemError when an empty bytestring is passed.

   - bpo-28181(305): Get antigravity over HTTPS. Patch by Kaartic
     Sivaraam.

   - bpo-25895(306): Enable WebSocket URL schemes in
     urllib.parse.urljoin.  Patch by Gergely Imreh and Markus
     Holtermann.

   - bpo-28114(307): Fix a crash in parse_envlist() when env contains
     byte strings.  Patch by Eryk Sun.

   - bpo-27599(308): Fixed buffer overrun in binascii.b2a_qp() and
     binascii.a2b_qp().

   - bpo-27906(309): Fix socket accept exhaustion during high TCP
     traffic.  Patch by Kevin Conway.

   - bpo-28174(310): Handle when SO_REUSEPORT isn’t properly supported.
     Patch by Seth Michael Larson.

   - bpo-26654(311): Inspect functools.partial in
     asyncio.Handle.__repr__.  Patch by iceboy.

   - bpo-26909(312): Fix slow pipes IO in asyncio.  Patch by INADA
     Naoki.

   - bpo-28176(313): Fix callbacks race in
     asyncio.SelectorLoop.sock_connect.

   - bpo-27759(314): Fix selectors incorrectly retain invalid file
     descriptors.  Patch by Mark Williams.

   - bpo-28325(315): Remove vestigial MacOS 9 macurl2path module and its
     tests.

   - bpo-28368(316): Refuse monitoring processes if the child watcher
     has no loop attached.  Patch by Vincent Michel.

   - bpo-28369(317): Raise RuntimeError when transport’s FD is used with
     add_reader, add_writer, etc.

   - bpo-28370(318): Speedup asyncio.StreamReader.readexactly.  Patch by
     Коренберг Марк.

   - bpo-28371(319): Deprecate passing asyncio.Handles to
     run_in_executor.

   - bpo-28372(320): Fix asyncio to support formatting of non-python
     coroutines.

   - bpo-28399(321): Remove UNIX socket from FS before binding.  Patch
     by Коренберг Марк.

   - bpo-27972(322): Prohibit Tasks to await on themselves.

   - bpo-24142(323): Reading a corrupt config file left configparser in
     an invalid state.  Original patch by Florian Höch.

   - bpo-29581(324): ABCMeta.__new__ now accepts ‘**kwargs’, allowing
     abstract base classes to use keyword parameters in
     __init_subclass__.  Patch by Nate Soares.

   - bpo-25532(325): inspect.unwrap() will now only try to unwrap an
     object sys.getrecursionlimit() times, to protect against objects
     which create a new object on every attribute access.

   - bpo-30177(326): path.resolve(strict=False) no longer cuts the path
     after the first element not present in the filesystem.  Patch by
     Antoine Pietri.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31499

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31482

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31544

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31234

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31457

   (8) https://bugs.python.org/issue?@action=redirect&bpo=31431

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31233

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28638

   (11) https://bugs.python.org/issue?@action=redirect&bpo=31400

   (12) https://bugs.python.org/issue?@action=redirect&bpo=27629

   (13) https://bugs.python.org/issue?@action=redirect&bpo=28958

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28182

   (15) https://bugs.python.org/issue?@action=redirect&bpo=27340

   (16) https://bugs.python.org/issue?@action=redirect&bpo=14191

   (17) https://bugs.python.org/issue?@action=redirect&bpo=31178

   (18) https://bugs.python.org/issue?@action=redirect&bpo=31350

   (19) https://bugs.python.org/issue?@action=redirect&bpo=31170

   (20) https://bugs.python.org/issue?@action=redirect&bpo=29136

   (21) https://bugs.python.org/issue?@action=redirect&bpo=1198569

   (22) https://bugs.python.org/issue?@action=redirect&bpo=31326

   (23) https://bugs.python.org/issue?@action=redirect&bpo=27144

   (24) https://bugs.python.org/issue?@action=redirect&bpo=31281

   (25) https://bugs.python.org/issue?@action=redirect&bpo=10746

   (26) https://peps.python.org/pep-3118/

   (27) https://bugs.python.org/issue?@action=redirect&bpo=27584

   (28) https://bugs.python.org/issue?@action=redirect&bpo=22536

   (29) https://bugs.python.org/issue?@action=redirect&bpo=29741

   (30) https://bugs.python.org/issue?@action=redirect&bpo=31249

   (31) https://bugs.python.org/issue?@action=redirect&bpo=31247

   (32) https://bugs.python.org/issue?@action=redirect&bpo=23835

   (33) https://bugs.python.org/issue?@action=redirect&bpo=31238

   (34) https://bugs.python.org/issue?@action=redirect&bpo=5001

   (35) https://bugs.python.org/issue?@action=redirect&bpo=31109

   (36) https://bugs.python.org/issue?@action=redirect&bpo=30102

   (37) https://bugs.python.org/issue?@action=redirect&bpo=18966

   (38) https://bugs.python.org/issue?@action=redirect&bpo=31183

   (39) https://bugs.python.org/issue?@action=redirect&bpo=5001

   (40) https://bugs.python.org/issue?@action=redirect&bpo=31185

   (41) https://bugs.python.org/issue?@action=redirect&bpo=31151

   (42) https://bugs.python.org/issue?@action=redirect&bpo=31072

   (43) https://bugs.python.org/issue?@action=redirect&bpo=24700

   (44) https://bugs.python.org/issue?@action=redirect&bpo=31135

   (45) https://bugs.python.org/issue?@action=redirect&bpo=31107

   (46) https://bugs.python.org/issue?@action=redirect&bpo=31080

   (47) https://bugs.python.org/issue?@action=redirect&bpo=30897

   (48) https://bugs.python.org/issue?@action=redirect&bpo=31061

   (49) https://bugs.python.org/issue?@action=redirect&bpo=30987

   (50) https://bugs.python.org/issue?@action=redirect&bpo=30522

   (51) https://bugs.python.org/issue?@action=redirect&bpo=30502

   (52) https://bugs.python.org/issue?@action=redirect&bpo=5288

   (53) https://bugs.python.org/issue?@action=redirect&bpo=30919

   (54) https://bugs.python.org/issue?@action=redirect&bpo=26732

   (55) https://bugs.python.org/issue?@action=redirect&bpo=29403

   (56) https://bugs.python.org/issue?@action=redirect&bpo=30961

   (57) https://bugs.python.org/issue?@action=redirect&bpo=19896

   (58) https://bugs.python.org/issue?@action=redirect&bpo=30946

   (59) https://bugs.python.org/issue?@action=redirect&bpo=25684

   (60) https://bugs.python.org/issue?@action=redirect&bpo=30886

   (61) https://bugs.python.org/issue?@action=redirect&bpo=29854

   (62) https://bugs.python.org/issue?@action=redirect&bpo=30794

   (63) https://bugs.python.org/issue?@action=redirect&bpo=30319

   (64) https://bugs.python.org/issue?@action=redirect&bpo=30828

   (65) https://bugs.python.org/issue?@action=redirect&bpo=30302

   (66) https://bugs.python.org/issue?@action=redirect&bpo=30807

   (67) https://bugs.python.org/issue?@action=redirect&bpo=30441

   (68) https://bugs.python.org/issue?@action=redirect&bpo=29585

   (69) https://bugs.python.org/issue?@action=redirect&bpo=29293

   (70) https://bugs.python.org/issue?@action=redirect&bpo=30532

   (71) https://bugs.python.org/issue?@action=redirect&bpo=30596

   (72) https://bugs.python.org/issue?@action=redirect&bpo=9146

   (73) https://bugs.python.org/issue?@action=redirect&bpo=29169

   (74) https://bugs.python.org/issue?@action=redirect&bpo=30119

   (75) https://bugs.python.org/issue?@action=redirect&bpo=30879

   (76) https://bugs.python.org/issue?@action=redirect&bpo=30746

   (77) https://bugs.python.org/issue?@action=redirect&bpo=30664

   (78) https://bugs.python.org/issue?@action=redirect&bpo=21071

   (79) https://bugs.python.org/issue?@action=redirect&bpo=29212

   (80) https://bugs.python.org/issue?@action=redirect&bpo=29755

   (81) https://bugs.python.org/issue?@action=redirect&bpo=30616

   (82) https://bugs.python.org/issue?@action=redirect&bpo=30038

   (83) https://bugs.python.org/issue?@action=redirect&bpo=23894

   (84) https://bugs.python.org/issue?@action=redirect&bpo=24744

   (85) https://bugs.python.org/issue?@action=redirect&bpo=24484

   (86) https://bugs.python.org/issue?@action=redirect&bpo=30589

   (87) https://bugs.python.org/issue?@action=redirect&bpo=28994

   (88) https://bugs.python.org/issue?@action=redirect&bpo=30508

   (89) https://bugs.python.org/issue?@action=redirect&bpo=30645

   (90) https://bugs.python.org/issue?@action=redirect&bpo=11822

   (91) https://bugs.python.org/issue?@action=redirect&bpo=30624

   (92) https://bugs.python.org/issue?@action=redirect&bpo=30595

   (93) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (94) https://bugs.python.org/issue?@action=redirect&bpo=30605

   (95) https://bugs.python.org/issue?@action=redirect&bpo=29870

   (96) https://bugs.python.org/issue?@action=redirect&bpo=29743

   (97) https://bugs.python.org/issue?@action=redirect&bpo=27585

   (98) https://bugs.python.org/issue?@action=redirect&bpo=30014

   (99) https://bugs.python.org/issue?@action=redirect&bpo=30418

   (100) https://bugs.python.org/issue?@action=redirect&bpo=30463

   (101) https://bugs.python.org/issue?@action=redirect&bpo=30520

   (102) https://bugs.python.org/issue?@action=redirect&bpo=30557

   (103) https://bugs.python.org/issue?@action=redirect&bpo=30526

   (104) https://bugs.python.org/issue?@action=redirect&bpo=30245

   (105) https://bugs.python.org/issue?@action=redirect&bpo=30378

   (106) https://bugs.python.org/issue?@action=redirect&bpo=16500

   (107) https://bugs.python.org/issue?@action=redirect&bpo=30470

   (108) https://bugs.python.org/issue?@action=redirect&bpo=30414

   (109) https://bugs.python.org/issue?@action=redirect&bpo=30003

   (110) https://bugs.python.org/issue?@action=redirect&bpo=30149

   (111) https://bugs.python.org/issue?@action=redirect&bpo=30436

   (112) https://bugs.python.org/issue?@action=redirect&bpo=30301

   (113) https://bugs.python.org/issue?@action=redirect&bpo=30375

   (114) https://bugs.python.org/issue?@action=redirect&bpo=30329

   (115) https://bugs.python.org/issue?@action=redirect&bpo=29196

   (116) https://bugs.python.org/issue?@action=redirect&bpo=9850

   (117) https://bugs.python.org/issue?@action=redirect&bpo=30299

   (118) https://bugs.python.org/issue?@action=redirect&bpo=30048

   (119) https://bugs.python.org/issue?@action=redirect&bpo=30266

   (120) https://bugs.python.org/issue?@action=redirect&bpo=25958

   (121) https://bugs.python.org/issue?@action=redirect&bpo=30340

   (122) https://bugs.python.org/issue?@action=redirect&bpo=30298

   (123) https://bugs.python.org/issue?@action=redirect&bpo=30285

   (124) https://bugs.python.org/issue?@action=redirect&bpo=29990

   (125) https://bugs.python.org/issue?@action=redirect&bpo=29979

   (126) https://bugs.python.org/issue?@action=redirect&bpo=30243

   (127) https://bugs.python.org/issue?@action=redirect&bpo=30215

   (128) https://bugs.python.org/issue?@action=redirect&bpo=30185

   (129) https://bugs.python.org/issue?@action=redirect&bpo=30103

   (130) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (131) https://bugs.python.org/issue?@action=redirect&bpo=30205

   (132) https://bugs.python.org/issue?@action=redirect&bpo=30228

   (133) https://bugs.python.org/issue?@action=redirect&bpo=30190

   (134) https://bugs.python.org/issue?@action=redirect&bpo=30101

   (135) https://bugs.python.org/issue?@action=redirect&bpo=29822

   (136) https://bugs.python.org/issue?@action=redirect&bpo=29960

   (137) https://bugs.python.org/issue?@action=redirect&bpo=30070

   (138) https://bugs.python.org/issue?@action=redirect&bpo=22352

   (139) https://bugs.python.org/issue?@action=redirect&bpo=30061

   (140) https://bugs.python.org/issue?@action=redirect&bpo=30218

   (141) https://bugs.python.org/issue?@action=redirect&bpo=10076

   (142) https://bugs.python.org/issue?@action=redirect&bpo=30068

   (143) https://bugs.python.org/issue?@action=redirect&bpo=29694

   (144) https://bugs.python.org/issue?@action=redirect&bpo=29692

   (145) https://bugs.python.org/issue?@action=redirect&bpo=26187

   (146) https://bugs.python.org/issue?@action=redirect&bpo=9303

   (147) https://bugs.python.org/issue?@action=redirect&bpo=30017

   (148) https://bugs.python.org/issue?@action=redirect&bpo=29998

   (149) https://bugs.python.org/issue?@action=redirect&bpo=29995

   (150) https://bugs.python.org/issue?@action=redirect&bpo=29962

   (151) https://bugs.python.org/issue?@action=redirect&bpo=29649

   (152) https://bugs.python.org/issue?@action=redirect&bpo=29654

   (153) https://bugs.python.org/issue?@action=redirect&bpo=29931

   (154) https://bugs.python.org/issue?@action=redirect&bpo=29953

   (155) https://bugs.python.org/issue?@action=redirect&bpo=29942

   (156) https://bugs.python.org/issue?@action=redirect&bpo=10030

   (157) https://bugs.python.org/issue?@action=redirect&bpo=29204

   (158) https://bugs.python.org/issue?@action=redirect&bpo=27863

   (159) https://bugs.python.org/issue?@action=redirect&bpo=25996

   (160) https://bugs.python.org/issue?@action=redirect&bpo=28699

   (161) https://bugs.python.org/issue?@action=redirect&bpo=23890

   (162) https://bugs.python.org/issue?@action=redirect&bpo=29901

   (163) https://bugs.python.org/issue?@action=redirect&bpo=25803

   (164) https://bugs.python.org/issue?@action=redirect&bpo=29861

   (165) https://bugs.python.org/issue?@action=redirect&bpo=19930

   (166) https://bugs.python.org/issue?@action=redirect&bpo=29884

   (167) https://bugs.python.org/issue?@action=redirect&bpo=25455

   (168) https://bugs.python.org/issue?@action=redirect&bpo=29800

   (169) https://bugs.python.org/issue?@action=redirect&bpo=8256

   (170) https://bugs.python.org/issue?@action=redirect&bpo=28692

   (171) https://bugs.python.org/issue?@action=redirect&bpo=26121

   (172) https://bugs.python.org/issue?@action=redirect&bpo=29619

   (173) https://bugs.python.org/issue?@action=redirect&bpo=28298

   (174) https://bugs.python.org/issue?@action=redirect&bpo=29645

   (175) https://bugs.python.org/issue?@action=redirect&bpo=28231

   (176) https://bugs.python.org/issue?@action=redirect&bpo=26915

   (177) https://bugs.python.org/issue?@action=redirect&bpo=28682

   (178) https://bugs.python.org/issue?@action=redirect&bpo=29728

   (179) https://bugs.python.org/issue?@action=redirect&bpo=29623

   (180) https://bugs.python.org/issue?@action=redirect&bpo=9303

   (181) https://bugs.python.org/issue?@action=redirect&bpo=28963

   (182) https://bugs.python.org/issue?@action=redirect&bpo=29704

   (183) https://bugs.python.org/issue?@action=redirect&bpo=29271

   (184) https://bugs.python.org/issue?@action=redirect&bpo=29703

   (185) https://bugs.python.org/issue?@action=redirect&bpo=29615

   (186) https://bugs.python.org/issue?@action=redirect&bpo=7769

   (187) https://bugs.python.org/issue?@action=redirect&bpo=29376

   (188) https://bugs.python.org/issue?@action=redirect&bpo=28624

   (189) https://bugs.python.org/issue?@action=redirect&bpo=28518

   (190) https://bugs.python.org/issue?@action=redirect&bpo=29742

   (191) https://bugs.python.org/issue?@action=redirect&bpo=16285

   (192) https://bugs.python.org/issue?@action=redirect&bpo=29532

   (193) https://bugs.python.org/issue?@action=redirect&bpo=29110

   (194) https://bugs.python.org/issue?@action=redirect&bpo=22807

   (195) https://bugs.python.org/issue?@action=redirect&bpo=29576

   (196) https://bugs.python.org/issue?@action=redirect&bpo=29534

   (197) https://bugs.python.org/issue?@action=redirect&bpo=10379

   (198) https://bugs.python.org/issue?@action=redirect&bpo=29851

   (199) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (200) https://bugs.python.org/issue?@action=redirect&bpo=29100

   (201) https://bugs.python.org/issue?@action=redirect&bpo=29416

   (202) https://bugs.python.org/issue?@action=redirect&bpo=29444

   (203) https://bugs.python.org/issue?@action=redirect&bpo=29377

   (204) https://bugs.python.org/issue?@action=redirect&bpo=29218

   (205) https://bugs.python.org/issue?@action=redirect&bpo=29368

   (206) https://bugs.python.org/issue?@action=redirect&bpo=29338

   (207) https://bugs.python.org/issue?@action=redirect&bpo=29335

   (208) https://bugs.python.org/issue?@action=redirect&bpo=29290

   (209) https://bugs.python.org/issue?@action=redirect&bpo=28735

   (210) https://bugs.python.org/issue?@action=redirect&bpo=29197

   (211) https://bugs.python.org/issue?@action=redirect&bpo=29210

   (212) https://bugs.python.org/issue?@action=redirect&bpo=29219

   (213) https://bugs.python.org/issue?@action=redirect&bpo=29192

   (214) https://bugs.python.org/issue?@action=redirect&bpo=29193

   (215) https://bugs.python.org/issue?@action=redirect&bpo=29195

   (216) https://bugs.python.org/issue?@action=redirect&bpo=28969

   (217) https://bugs.python.org/issue?@action=redirect&bpo=20804

   (218) https://bugs.python.org/issue?@action=redirect&bpo=29142

   (219) https://bugs.python.org/issue?@action=redirect&bpo=28961

   (220) https://bugs.python.org/issue?@action=redirect&bpo=15812

   (221) https://bugs.python.org/issue?@action=redirect&bpo=28985

   (222) https://bugs.python.org/issue?@action=redirect&bpo=29079

   (223) https://bugs.python.org/issue?@action=redirect&bpo=13051

   (224) https://bugs.python.org/issue?@action=redirect&bpo=9770

   (225) https://bugs.python.org/issue?@action=redirect&bpo=28427

   (226) https://bugs.python.org/issue?@action=redirect&bpo=28923

   (227) https://bugs.python.org/issue?@action=redirect&bpo=28871

   (228) https://bugs.python.org/issue?@action=redirect&bpo=19542

   (229) https://bugs.python.org/issue?@action=redirect&bpo=20191

   (230) https://bugs.python.org/issue?@action=redirect&bpo=16255

   (231) https://bugs.python.org/issue?@action=redirect&bpo=28779

   (232) https://bugs.python.org/issue?@action=redirect&bpo=26937

   (233) https://bugs.python.org/issue?@action=redirect&bpo=28847

   (234) https://bugs.python.org/issue?@action=redirect&bpo=27030

   (235) https://bugs.python.org/issue?@action=redirect&bpo=28835

   (236) https://bugs.python.org/issue?@action=redirect&bpo=27172

   (237) https://bugs.python.org/issue?@action=redirect&bpo=28740

   (238) https://bugs.python.org/issue?@action=redirect&bpo=26273

   (239) https://bugs.python.org/issue?@action=redirect&bpo=28752

   (240) https://bugs.python.org/issue?@action=redirect&bpo=28727

   (241) https://bugs.python.org/issue?@action=redirect&bpo=18383

   (242) https://bugs.python.org/issue?@action=redirect&bpo=20572

   (243) https://bugs.python.org/issue?@action=redirect&bpo=25659

   (244) https://bugs.python.org/issue?@action=redirect&bpo=28548

   (245) https://bugs.python.org/issue?@action=redirect&bpo=19717

   (246) https://bugs.python.org/issue?@action=redirect&bpo=28563

   (247) https://bugs.python.org/issue?@action=redirect&bpo=28387

   (248) https://bugs.python.org/issue?@action=redirect&bpo=27517

   (249) https://bugs.python.org/issue?@action=redirect&bpo=28549

   (250) https://bugs.python.org/issue?@action=redirect&bpo=28449

   (251) https://bugs.python.org/issue?@action=redirect&bpo=23262

   (252) https://bugs.python.org/issue?@action=redirect&bpo=24241

   (253) https://bugs.python.org/issue?@action=redirect&bpo=27939

   (254) https://bugs.python.org/issue?@action=redirect&bpo=28255

   (255) https://bugs.python.org/issue?@action=redirect&bpo=28255

   (256) https://bugs.python.org/issue?@action=redirect&bpo=20491

   (257) https://bugs.python.org/issue?@action=redirect&bpo=28353

   (258) https://bugs.python.org/issue?@action=redirect&bpo=28430

   (259) https://bugs.python.org/issue?@action=redirect&bpo=27025

   (260) https://bugs.python.org/issue?@action=redirect&bpo=25464

   (261) https://bugs.python.org/issue?@action=redirect&bpo=28488

   (262) https://bugs.python.org/issue?@action=redirect&bpo=25953

   (263) https://bugs.python.org/issue?@action=redirect&bpo=28469

   (264) https://bugs.python.org/issue?@action=redirect&bpo=28115

   (265) https://bugs.python.org/issue?@action=redirect&bpo=18219

   (266) https://bugs.python.org/issue?@action=redirect&bpo=28448

   (267) https://bugs.python.org/issue?@action=redirect&bpo=23214

   (268) https://bugs.python.org/issue?@action=redirect&bpo=28480

   (269) https://bugs.python.org/issue?@action=redirect&bpo=28240

   (270) https://bugs.python.org/issue?@action=redirect&bpo=28240

   (271) https://bugs.python.org/issue?@action=redirect&bpo=28240

   (272) https://github.com/pypa/setuptools/issues/100

   (273) https://bugs.python.org/issue?@action=redirect&bpo=24452

   (274) https://bugs.python.org/issue?@action=redirect&bpo=20766

   (275) https://bugs.python.org/issue?@action=redirect&bpo=27998

   (276) https://bugs.python.org/issue?@action=redirect&bpo=28317

   (277) https://bugs.python.org/issue?@action=redirect&bpo=28380

   (278) https://bugs.python.org/issue?@action=redirect&bpo=28229

   (279) https://bugs.python.org/issue?@action=redirect&bpo=28321

   (280) https://bugs.python.org/issue?@action=redirect&bpo=28225

   (281) https://bugs.python.org/issue?@action=redirect&bpo=28227

   (282) https://bugs.python.org/issue?@action=redirect&bpo=28332

   (283) https://bugs.python.org/issue?@action=redirect&bpo=27358

   (284) https://bugs.python.org/issue?@action=redirect&bpo=28257

   (285) https://bugs.python.org/issue?@action=redirect&bpo=28322

   (286) https://bugs.python.org/issue?@action=redirect&bpo=28228

   (287) https://bugs.python.org/issue?@action=redirect&bpo=28226

   (288) https://bugs.python.org/issue?@action=redirect&bpo=28314

   (289) https://bugs.python.org/issue?@action=redirect&bpo=28148

   (290) https://bugs.python.org/issue?@action=redirect&bpo=28253

   (291) https://bugs.python.org/issue?@action=redirect&bpo=28275

   (292) https://bugs.python.org/issue?@action=redirect&bpo=27897

   (293) https://bugs.python.org/issue?@action=redirect&bpo=18844

   (294) https://bugs.python.org/issue?@action=redirect&bpo=18893

   (295) https://bugs.python.org/issue?@action=redirect&bpo=27611

   (296) https://bugs.python.org/issue?@action=redirect&bpo=27348

   (297) https://bugs.python.org/issue?@action=redirect&bpo=25651

   (298) https://bugs.python.org/issue?@action=redirect&bpo=27778

   (299) https://bugs.python.org/issue?@action=redirect&bpo=28200

   (300) https://bugs.python.org/issue?@action=redirect&bpo=25400

   (301) https://bugs.python.org/issue?@action=redirect&bpo=27932

   (302) https://bugs.python.org/issue?@action=redirect&bpo=28075

   (303) https://bugs.python.org/issue?@action=redirect&bpo=22493

   (304) https://bugs.python.org/issue?@action=redirect&bpo=25270

   (305) https://bugs.python.org/issue?@action=redirect&bpo=28181

   (306) https://bugs.python.org/issue?@action=redirect&bpo=25895

   (307) https://bugs.python.org/issue?@action=redirect&bpo=28114

   (308) https://bugs.python.org/issue?@action=redirect&bpo=27599

   (309) https://bugs.python.org/issue?@action=redirect&bpo=27906

   (310) https://bugs.python.org/issue?@action=redirect&bpo=28174

   (311) https://bugs.python.org/issue?@action=redirect&bpo=26654

   (312) https://bugs.python.org/issue?@action=redirect&bpo=26909

   (313) https://bugs.python.org/issue?@action=redirect&bpo=28176

   (314) https://bugs.python.org/issue?@action=redirect&bpo=27759

   (315) https://bugs.python.org/issue?@action=redirect&bpo=28325

   (316) https://bugs.python.org/issue?@action=redirect&bpo=28368

   (317) https://bugs.python.org/issue?@action=redirect&bpo=28369

   (318) https://bugs.python.org/issue?@action=redirect&bpo=28370

   (319) https://bugs.python.org/issue?@action=redirect&bpo=28371

   (320) https://bugs.python.org/issue?@action=redirect&bpo=28372

   (321) https://bugs.python.org/issue?@action=redirect&bpo=28399

   (322) https://bugs.python.org/issue?@action=redirect&bpo=27972

   (323) https://bugs.python.org/issue?@action=redirect&bpo=24142

   (324) https://bugs.python.org/issue?@action=redirect&bpo=29581

   (325) https://bugs.python.org/issue?@action=redirect&bpo=25532

   (326) https://bugs.python.org/issue?@action=redirect&bpo=30177


File: python.info,  Node: Documentation<65>,  Next: Tests<62>,  Prev: Library<172>,  Up: Python 3 7 0 alpha 1

1.24.72.4 Documentation
.......................

   - bpo-31294(1): Fix incomplete code snippet in the
     ZeroMQSocketListener and ZeroMQSocketHandler examples and adapt
     them to Python 3.

   - bpo-21649(2): Add RFC 7525 and Mozilla server side TLS links to SSL
     documentation.

   - bpo-31128(3): Allow the pydoc server to bind to arbitrary
     hostnames.

   - bpo-30803(4): Clarify doc on truth value testing.  Original patch
     by Peter Thomassen.

   - bpo-30176(5): Add missing attribute related constants in curses
     documentation.

   - bpo-30052(6): the link targets for *note bytes(): 192. and *note
     bytearray(): 344. are now their respective type definitions, rather
     than the corresponding builtin function entries.  Use *note bytes:
     1e82. and *note bytearray: 1e83. to reference the latter.  In order
     to ensure this and future cross-reference updates are applied
     automatically, the daily documentation builds now disable the
     default output caching features in Sphinx.

   - bpo-26985(7): Add missing info of code object in inspect
     documentation.

   - bpo-19824(8): Improve the documentation for, and links to, template
     strings by emphasizing their utility for internationalization, and
     by clarifying some usage constraints.  (See also: bpo-20314(9),
     bpo-12518(10))

   - bpo-28929(11): Link the documentation to its source file on GitHub.

   - bpo-25008(12): Document smtpd.py as effectively deprecated and add
     a pointer to aiosmtpd, a third-party asyncio-based replacement.

   - bpo-26355(13): Add canonical header link on each page to
     corresponding major version of the documentation.  Patch by
     Matthias Bussonnier.

   - bpo-29349(14): Fix Python 2 syntax in code for building the
     documentation.

   - bpo-23722(15): The data model reference and the porting section in
     the 3.6 What’s New guide now cover the additional ‘__classcell__’
     handling needed for custom metaclasses to fully support PEP 487(16)
     and zero-argument ‘super()’.

   - bpo-28513(17): Documented command-line interface of zipfile.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31294

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21649

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31128

   (4) https://bugs.python.org/issue?@action=redirect&bpo=30803

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30176

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30052

   (7) https://bugs.python.org/issue?@action=redirect&bpo=26985

   (8) https://bugs.python.org/issue?@action=redirect&bpo=19824

   (9) https://bugs.python.org/issue?@action=redirect&bpo=20314

   (10) https://bugs.python.org/issue?@action=redirect&bpo=12518

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28929

   (12) https://bugs.python.org/issue?@action=redirect&bpo=25008

   (13) https://bugs.python.org/issue?@action=redirect&bpo=26355

   (14) https://bugs.python.org/issue?@action=redirect&bpo=29349

   (15) https://bugs.python.org/issue?@action=redirect&bpo=23722

   (16) https://peps.python.org/pep-0487/

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28513


File: python.info,  Node: Tests<62>,  Next: Build<70>,  Prev: Documentation<65>,  Up: Python 3 7 0 alpha 1

1.24.72.5 Tests
...............

   - bpo-29639(1): test.support.HOST is now «localhost», a new HOSTv4
     constant has been added for your ‘127.0.0.1’ needs, similar to the
     existing HOSTv6 constant.

   - bpo-31320(2): Silence traceback in test_ssl

   - bpo-31346(3): Prefer PROTOCOL_TLS_CLIENT and PROTOCOL_TLS_SERVER
     protocols for SSLContext.

   - bpo-25674(4): Remove sha256.tbs-internet.com ssl test

   - bpo-30715(5): Address ALPN callback changes for OpenSSL 1.1.0f.
     The latest version behaves like OpenSSL 1.0.2 and no longer aborts
     handshake.

   - bpo-30822(6): regrtest: Exclude tzdata from regrtest –all.  When
     running the test suite using –use=all / -u all, exclude tzdata
     since it makes test_datetime too slow (15-20 min on some buildbots)
     which then times out on some buildbots.  Fix also regrtest command
     line parser to allow passing -u extralargefile to run
     test_zipfile64.

   - bpo-30695(7): Add the ‘set_nomemory(start, stop)’ and
     ‘remove_mem_hooks()’ functions to the ‘_testcapi’ module.

   - bpo-30357(8): test_thread: setUp() now uses
     support.threading_setup() and support.threading_cleanup() to wait
     until threads complete to avoid random side effects on following
     tests.  Initial patch written by Grzegorz Grzywacz.

   - bpo-30197(9): Enhanced functions swap_attr() and swap_item() in the
     test.support module.  They now work when delete replaced attribute
     or item inside the with statement.  The old value of the attribute
     or item (or None if it doesn’t exist) now will be assigned to the
     target of the «as» clause, if there is one.

   - bpo-24932(10): Use proper command line parsing in _testembed

   - bpo-28950(11): Disallow -j0 to be combined with -T/-l in regrtest
     command line arguments.

   - bpo-28683(12): Fix the tests that bind() a unix socket and raise
     PermissionError on Android for a non-root user.

   - bpo-26936(13): Fix the test_socket failures on Android -
     getservbyname(), getservbyport() and getaddrinfo() are broken on
     some Android API levels.

   - bpo-28666(14): Now test.support.rmtree is able to remove unwritable
     or unreadable directories.

   - bpo-23839(15): Various caches now are cleared before running every
     test file.

   - bpo-26944(16): Fix test_posix for Android where “id -G” is entirely
     wrong or missing the effective gid.

   - bpo-28409(17): regrtest: fix the parser of command line arguments.

   - bpo-28217(18): Adds _testconsole module to test console input.

   - bpo-26939(19): Add the support.setswitchinterval() function to fix
     test_functools hanging on the Android armv7 qemu emulator.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29639

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31320

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31346

   (4) https://bugs.python.org/issue?@action=redirect&bpo=25674

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30715

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30822

   (7) https://bugs.python.org/issue?@action=redirect&bpo=30695

   (8) https://bugs.python.org/issue?@action=redirect&bpo=30357

   (9) https://bugs.python.org/issue?@action=redirect&bpo=30197

   (10) https://bugs.python.org/issue?@action=redirect&bpo=24932

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28950

   (12) https://bugs.python.org/issue?@action=redirect&bpo=28683

   (13) https://bugs.python.org/issue?@action=redirect&bpo=26936

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28666

   (15) https://bugs.python.org/issue?@action=redirect&bpo=23839

   (16) https://bugs.python.org/issue?@action=redirect&bpo=26944

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28409

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28217

   (19) https://bugs.python.org/issue?@action=redirect&bpo=26939


File: python.info,  Node: Build<70>,  Next: Windows<62>,  Prev: Tests<62>,  Up: Python 3 7 0 alpha 1

1.24.72.6 Build
...............

   - bpo-31354(1): Allow ‘--with-lto’ to be used on all builds, not just
     ‘make profile-opt’.

   - bpo-31370(2): Remove support for building –without-threads.  This
     option is not really useful anymore in the 21st century.  Removing
     lots of conditional paths allows us to simplify the code base,
     including in difficult to maintain low-level internal code.

   - bpo-31341(3): Per PEP 11(4), support for the IRIX operating system
     was removed.

   - bpo-30854(5): Fix compile error when compiling –without-threads.
     Patch by Masayuki Yamamoto.

   - bpo-30687(6): Locate msbuild.exe on Windows when building rather
     than vcvarsall.bat

   - bpo-20210(7): Support the 'disabled' marker in Setup files.
     Extension modules listed after this marker are not built at all,
     neither by the Makefile nor by setup.py.

   - bpo-29941(8): Add ‘--with-assertions’ configure flag to explicitly
     enable C ‘assert()’ checks.  Defaults to off.  ‘--with-pydebug’
     implies ‘--with-assertions’.

   - bpo-28787(9): Fix out-of-tree builds of Python when configured with
     ‘--with--dtrace’.

   - bpo-29243(10): Prevent unnecessary rebuilding of Python during
     ‘make test’, ‘make install’ and some other make targets when
     configured with ‘--enable-optimizations’.

   - bpo-23404(11): Don’t regenerate generated files based on file
     modification time anymore: the action is now explicit.  Replace
     ‘make touch’ with ‘make regen-all’.

   - bpo-29643(12): Fix ‘--enable-optimization’ didn’t work.

   - bpo-27593(13): sys.version and the platform module python_build(),
     python_branch(), and python_revision() functions now use git
     information rather than hg when building from a repo.

   - bpo-29572(14): Update Windows build and OS X installers to use
     OpenSSL 1.0.2k.

   - bpo-27659(15): Prohibit implicit C function declarations: use
     ‘-Werror=implicit-function-declaration’ when possible (GCC and
     Clang, but it depends on the compiler version).  Patch written by
     Chi Hsuan Yen.

   - bpo-29384(16): Remove old Be OS helper scripts.

   - bpo-26851(17): Set Android compilation and link flags.

   - bpo-28768(18): Fix implicit declaration of function _setmode.
     Patch by Masayuki Yamamoto

   - bpo-29080(19): Removes hard dependency on hg.exe from
     PCBuild/build.bat

   - bpo-23903(20): Added missed names to PC/python3.def.

   - bpo-28762(21): lockf() is available on Android API level 24, but
     the F_LOCK macro is not defined in android-ndk-r13.

   - bpo-28538(22): Fix the compilation error that occurs because
     if_nameindex() is available on Android API level 24, but the
     if_nameindex structure is not defined.

   - bpo-20211(23): Do not add the directory for installing C header
     files and the directory for installing object code libraries to the
     cross compilation search paths.  Original patch by Thomas
     Petazzoni.

   - bpo-28849(24): Do not define sys.implementation._multiarch on
     Android.

   - bpo-10656(25): Fix out-of-tree building on AIX. Patch by Tristan
     Carel and Michael Haubenwallner.

   - bpo-26359(26): Rename –with-optimiations to –enable-optimizations.

   - bpo-28444(27): Fix missing extensions modules when cross compiling.

   - bpo-28208(28): Update Windows build and OS X installers to use
     SQLite 3.14.2.

   - bpo-28248(29): Update Windows build and OS X installers to use
     OpenSSL 1.0.2j.

   - bpo-21124(30): Fix building the _struct module on Cygwin by passing
     ‘NULL’ instead of ‘&PyType_Type’ to PyVarObject_HEAD_INIT. Patch by
     Masayuki Yamamoto.

   - bpo-13756(31): Fix building extensions modules on Cygwin.  Patch by
     Roumen Petrov, based on original patch by Jason Tishler.

   - bpo-21085(32): Add configure check for siginfo_t.si_band, which
     Cygwin does not provide.  Patch by Masayuki Yamamoto with review
     and rebase by Erik Bray.

   - bpo-28258(33): Fixed build with Estonian locale (python-config and
     distclean targets in Makefile).  Patch by Arfrever Frehtes
     Taifersar Arahesis.

   - bpo-26661(34): setup.py now detects system libffi with multiarch
     wrapper.

   - bpo-27979(35): A full copy of libffi is no longer bundled for use
     when building _ctypes on non-OSX UNIX platforms.  An installed copy
     of libffi is now required when building _ctypes on such platforms.

   - bpo-15819(36): Remove redundant include search directory option for
     building outside the source tree.

   - bpo-28676(37): Prevent missing “getentropy” declaration warning on
     macOS. Patch by Gareth Rees.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31354

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31370

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31341

   (4) https://peps.python.org/pep-0011/

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30854

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30687

   (7) https://bugs.python.org/issue?@action=redirect&bpo=20210

   (8) https://bugs.python.org/issue?@action=redirect&bpo=29941

   (9) https://bugs.python.org/issue?@action=redirect&bpo=28787

   (10) https://bugs.python.org/issue?@action=redirect&bpo=29243

   (11) https://bugs.python.org/issue?@action=redirect&bpo=23404

   (12) https://bugs.python.org/issue?@action=redirect&bpo=29643

   (13) https://bugs.python.org/issue?@action=redirect&bpo=27593

   (14) https://bugs.python.org/issue?@action=redirect&bpo=29572

   (15) https://bugs.python.org/issue?@action=redirect&bpo=27659

   (16) https://bugs.python.org/issue?@action=redirect&bpo=29384

   (17) https://bugs.python.org/issue?@action=redirect&bpo=26851

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28768

   (19) https://bugs.python.org/issue?@action=redirect&bpo=29080

   (20) https://bugs.python.org/issue?@action=redirect&bpo=23903

   (21) https://bugs.python.org/issue?@action=redirect&bpo=28762

   (22) https://bugs.python.org/issue?@action=redirect&bpo=28538

   (23) https://bugs.python.org/issue?@action=redirect&bpo=20211

   (24) https://bugs.python.org/issue?@action=redirect&bpo=28849

   (25) https://bugs.python.org/issue?@action=redirect&bpo=10656

   (26) https://bugs.python.org/issue?@action=redirect&bpo=26359

   (27) https://bugs.python.org/issue?@action=redirect&bpo=28444

   (28) https://bugs.python.org/issue?@action=redirect&bpo=28208

   (29) https://bugs.python.org/issue?@action=redirect&bpo=28248

   (30) https://bugs.python.org/issue?@action=redirect&bpo=21124

   (31) https://bugs.python.org/issue?@action=redirect&bpo=13756

   (32) https://bugs.python.org/issue?@action=redirect&bpo=21085

   (33) https://bugs.python.org/issue?@action=redirect&bpo=28258

   (34) https://bugs.python.org/issue?@action=redirect&bpo=26661

   (35) https://bugs.python.org/issue?@action=redirect&bpo=27979

   (36) https://bugs.python.org/issue?@action=redirect&bpo=15819

   (37) https://bugs.python.org/issue?@action=redirect&bpo=28676


File: python.info,  Node: Windows<62>,  Next: IDLE<45>,  Prev: Build<70>,  Up: Python 3 7 0 alpha 1

1.24.72.7 Windows
.................

   - bpo-31392(1): Update Windows build to use OpenSSL 1.1.0f

   - bpo-30389(2): Adds detection of Visual Studio 2017 to distutils on
     Windows.

   - bpo-31358(3): zlib is no longer bundled in the CPython source,
     instead it is downloaded on demand just like bz2, lzma, OpenSSL,
     Tcl/Tk, and SQLite.

   - bpo-31340(4): Change to building with MSVC v141 (included with
     Visual Studio 2017)

   - bpo-30581(5): os.cpu_count() now returns the correct number of
     processors on Windows when the number of logical processors is
     greater than 64.

   - bpo-30916(6): Pre-build OpenSSL, Tcl and Tk and include the
     binaries in the build.

   - bpo-30731(7): Add a missing xmlns to python.manifest so that it
     matches the schema.

   - bpo-30291(8): Allow requiring 64-bit interpreters from py.exe using
     -64 suffix.  Contributed by Steve (Gadget) Barnes.

   - bpo-30362(9): Adds list options (-0, -0p) to py.exe launcher.
     Contributed by Steve Barnes.

   - bpo-23451(10): Fix socket deprecation warnings in socketmodule.c.
     Patch by Segev Finer.

   - bpo-30450(11): The build process on Windows no longer depends on
     Subversion, instead pulling external code from GitHub via a Python
     script.  If Python 3.6 is not found on the system (via ‘py -3.6’),
     NuGet is used to download a copy of 32-bit Python.

   - bpo-29579(12): Removes readme.txt from the installer.

   - bpo-25778(13): winreg does not truncate string correctly (Patch by
     Eryk Sun)

   - bpo-28896(14): Deprecate WindowsRegistryFinder and disable it by
     default

   - bpo-28522(15): Fixes mishandled buffer reallocation in getpathp.c

   - bpo-28402(16): Adds signed catalog files for stdlib on Windows.

   - bpo-28333(17): Enables Unicode for ps1/ps2 and input() prompts.
     (Patch by Eryk Sun)

   - bpo-28251(18): Improvements to help manuals on Windows.

   - bpo-28110(19): launcher.msi has different product codes between
     32-bit and 64-bit

   - bpo-28161(20): Opening CON for write access fails

   - bpo-28162(21): WindowsConsoleIO readall() fails if first line
     starts with Ctrl+Z

   - bpo-28163(22): WindowsConsoleIO fileno() passes wrong flags to
     _open_osfhandle

   - bpo-28164(23): _PyIO_get_console_type fails for various paths

   - bpo-28137(24): Renames Windows path file to ._pth

   - bpo-28138(25): Windows ._pth file should allow import site

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31392

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30389

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31358

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31340

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30581

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30916

   (7) https://bugs.python.org/issue?@action=redirect&bpo=30731

   (8) https://bugs.python.org/issue?@action=redirect&bpo=30291

   (9) https://bugs.python.org/issue?@action=redirect&bpo=30362

   (10) https://bugs.python.org/issue?@action=redirect&bpo=23451

   (11) https://bugs.python.org/issue?@action=redirect&bpo=30450

   (12) https://bugs.python.org/issue?@action=redirect&bpo=29579

   (13) https://bugs.python.org/issue?@action=redirect&bpo=25778

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28896

   (15) https://bugs.python.org/issue?@action=redirect&bpo=28522

   (16) https://bugs.python.org/issue?@action=redirect&bpo=28402

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28333

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28251

   (19) https://bugs.python.org/issue?@action=redirect&bpo=28110

   (20) https://bugs.python.org/issue?@action=redirect&bpo=28161

   (21) https://bugs.python.org/issue?@action=redirect&bpo=28162

   (22) https://bugs.python.org/issue?@action=redirect&bpo=28163

   (23) https://bugs.python.org/issue?@action=redirect&bpo=28164

   (24) https://bugs.python.org/issue?@action=redirect&bpo=28137

   (25) https://bugs.python.org/issue?@action=redirect&bpo=28138


File: python.info,  Node: IDLE<45>,  Next: Tools/Demos<43>,  Prev: Windows<62>,  Up: Python 3 7 0 alpha 1

1.24.72.8 IDLE
..............

   - bpo-31493(1): IDLE code context – fix code update and font update
     timers.  Canceling timers prevents a warning message when test_idle
     completes.

   - bpo-31488(2): IDLE - Update non-key options in former extension
     classes.  When applying configdialog changes, call .reload for each
     feature class.  Change ParenMatch so updated options affect
     existing instances attached to existing editor windows.

   - bpo-31477(3): IDLE - Improve rstrip entry in doc.  Strip trailing
     whitespace strips more than blank spaces.  Multiline string
     literals are not skipped.

   - bpo-31480(4): IDLE - make tests pass with zzdummy extension
     disabled by default.

   - bpo-31421(5): Document how IDLE runs tkinter programs.  IDLE calls
     tcl/tk update in the background in order to make live interaction
     and experimentation with tkinter applications much easier.

   - bpo-31414(6): IDLE – fix tk entry box tests by deleting first.
     Adding to an int entry is not the same as deleting and inserting
     because int(“”) will fail.

   - bpo-31051(7): Rearrange IDLE configdialog GenPage into Window,
     Editor, and Help sections.

   - bpo-30617(8): IDLE - Add docstrings and tests for outwin subclass
     of editor.  Move some data and functions from the class to module
     level.  Patch by Cheryl Sabella.

   - bpo-31287(9): IDLE - Do not modify tkinter.message in
     test_configdialog.

   - bpo-27099(10): Convert IDLE’s built-in “extensions” to regular
     features.  About 10 IDLE features were implemented as supposedly
     optional extensions.  Their different behavior could be confusing
     or worse for users and not good for maintenance.  Hence the
     conversion.  The main difference for users is that user
     configurable key bindings for builtin features are now handled
     uniformly.  Now, editing a binding in a keyset only affects its
     value in the keyset.  All bindings are defined together in the
     system-specific default keysets in config-extensions.def.  All
     custom keysets are saved as a whole in config-extension.cfg.  All
     take effect as soon as one clicks Apply or Ok.  The affected events
     are “<<force-open-completions>>”, “<<expand-word>>”,
     “<<force-open-calltip>>”, “<<flash-paren>>”,
     “<<format-paragraph>>”, “<<run-module>>”, “<<check-module>>”, and
     “<<zoom-height>>”.  Any (global) customizations made before 3.6.3
     will not affect their keyset-specific customization after 3.6.3.
     and vice versa.  Initial patch by Charles Wohlganger.

   - bpo-31206(11): IDLE: Factor HighPage(Frame) class from
     ConfigDialog.  Patch by Cheryl Sabella.

   - bpo-31001(12): Add tests for configdialog highlight tab.  Patch by
     Cheryl Sabella.

   - bpo-31205(13): IDLE: Factor KeysPage(Frame) class from
     ConfigDialog.  The slightly modified tests continue to pass.  Patch
     by Cheryl Sabella.

   - bpo-31130(14): IDLE – stop leaks in test_configdialog.  Initial
     patch by Victor Stinner.

   - bpo-31002(15): Add tests for configdialog keys tab.  Patch by
     Cheryl Sabella.

   - bpo-19903(16): IDLE: Calltips use ‘inspect.signature’ instead of
     ‘inspect.getfullargspec’.  This improves calltips for builtins
     converted to use Argument Clinic.  Patch by Louie Lu.

   - bpo-31083(17): IDLE - Add an outline of a TabPage class in
     configdialog.  Update existing classes to match outline.  Initial
     patch by Cheryl Sabella.

   - bpo-31050(18): Factor GenPage(Frame) class from ConfigDialog.  The
     slightly modified tests continue to pass.  Patch by Cheryl Sabella.

   - bpo-31004(19): IDLE - Factor FontPage(Frame) class from
     ConfigDialog.  Slightly modified tests continue to pass.  Fix
     General tests.  Patch mostly by Cheryl Sabella.

   - bpo-30781(20): IDLE - Use ttk widgets in ConfigDialog.  Patches by
     Terry Jan Reedy and Cheryl Sabella.

   - bpo-31060(21): IDLE - Finish rearranging methods of ConfigDialog
     Grouping methods pertaining to each tab and the buttons will aid
     writing tests and improving the tabs and will enable splitting the
     groups into classes.

   - bpo-30853(22): IDLE – Factor a VarTrace class out of ConfigDialog.
     Instance tracers manages pairs consisting of a tk variable and a
     callback function.  When tracing is turned on, setting the variable
     calls the function.  Test coverage for the new class is 100%.

   - bpo-31003(23): IDLE: Add more tests for General tab.

   - bpo-30993(24): IDLE - Improve configdialog font page and tests.  In
     configdialog: Document causal pathways in create_font_tab
     docstring.  Simplify some attribute names.  Move set_samples calls
     to var_changed_font (idea from Cheryl Sabella).  Move related
     functions to positions after the create widgets function.  In
     test_configdialog: Fix test_font_set so not order dependent.  Fix
     renamed test_indent_scale so it tests the widget.  Adjust tests for
     movement of set_samples call.  Add tests for load functions.  Put
     all font tests in one class and tab indent tests in another.
     Except for two lines, these tests completely cover the related
     functions.

   - bpo-30981(25): IDLE – Add more configdialog font page tests.

   - bpo-28523(26): IDLE: replace “colour” with “color” in configdialog.

   - bpo-30917(27): Add tests for idlelib.config.IdleConf.  Increase
     coverage from 46% to 96%.  Patch by Louie Lu.

   - bpo-30934(28): Document coverage details for idlelib tests.  Add
     section to idlelib/idle-test/README.txt.  Include check that
     branches are taken both ways.  Exclude IDLE-specific code that does
     not run during unit tests.

   - bpo-30913(29): IDLE: Document ConfigDialog tk Vars, methods, and
     widgets in docstrings This will facilitate improving the dialog and
     splitting up the class.  Original patch by Cheryl Sabella.

   - bpo-30899(30): IDLE: Add tests for ConfigParser subclasses in
     config.  Patch by Louie Lu.

   - bpo-30881(31): IDLE: Add docstrings to browser.py.  Patch by Cheryl
     Sabella.

   - bpo-30851(32): IDLE: Remove unused variables in configdialog.  One
     is a duplicate, one is set but cannot be altered by users.  Patch
     by Cheryl Sabella.

   - bpo-30870(33): IDLE: In Settings dialog, select font with Up, Down
     keys as well as mouse.  Initial patch by Louie Lu.

   - bpo-8231(34): IDLE: call config.IdleConf.GetUserCfgDir only once.

   - bpo-30779(35): IDLE: Factor ConfigChanges class from configdialog,
     put in config; test.  * In config, put dump test code in a
     function; run it and unittest in “if __name__ == “__main__”.  * Add
     class config.ConfigChanges based on changes_class_v4.py on bpo
     issue.  * Add class test_config.ChangesTest, partly using
     configdialog_tests_v1.py.  * Revise configdialog to use
     ConfigChanges; see tracker msg297804.  * Revise test_configdialog
     to match configdialog changes.  * Remove configdialog functions
     unused or moved to ConfigChanges.  Cheryl Sabella contributed parts
     of the patch.

   - bpo-30777(36): IDLE: configdialog - Add docstrings and fix
     comments.  Patch by Cheryl Sabella.

   - bpo-30495(37): IDLE: Improve textview with docstrings, PEP8 names,
     and more tests.  Patch by Cheryl Sabella.

   - bpo-30723(38): IDLE: Make several improvements to parenmatch.  Add
     “parens” style to highlight both opener and closer.  Make “default”
     style, which is not default, a synonym for “opener”.  Make
     time-delay work the same with all styles.  Add help for config
     dialog extensions tab, including help for parenmatch.  Add new
     tests.  Original patch by Charles Wohlganger.

   - bpo-30674(39): IDLE: add docstrings to grep module.  Patch by
     Cheryl Sabella

   - bpo-21519(40): IDLE’s basic custom key entry dialog now detects
     duplicates properly.  Original patch by Saimadhav Heblikar.

   - bpo-29910(41): IDLE no longer deletes a character after commenting
     out a region by a key shortcut.  Add ‘return 'break'’ for this and
     other potential conflicts between IDLE and default key bindings.

   - bpo-30728(42): Review and change idlelib.configdialog names.
     Lowercase method and attribute names.  Replace “colour” with
     “color”, expand overly cryptic names, delete unneeded underscores.
     Replace ‘import *’ with specific imports.  Patches by Cheryl
     Sabella.

   - bpo-6739(43): IDLE: Verify user-entered key sequences by trying to
     bind them with tk.  Add tests for all 3 validation functions.
     Original patch by G Polo.  Tests added by Cheryl Sabella.

   - bpo-15786(44): Fix several problems with IDLE’s autocompletion box.
     The following should now work: clicking on selection box items;
     using the scrollbar; selecting an item by hitting Return.  Hangs on
     MacOSX should no longer happen.  Patch by Louie Lu.

   - bpo-25514(45): Add doc subsubsection about IDLE failure to start.
     Popup no-connection message directs users to this section.

   - bpo-30642(46): Fix reference leaks in IDLE tests.  Patches by Louie
     Lu and Terry Jan Reedy.

   - bpo-30495(47): Add docstrings for textview.py and use PEP8 names.
     Patches by Cheryl Sabella and Terry Jan Reedy.

   - bpo-30290(48): Help-about: use pep8 names and add tests.  Increase
     coverage to 100%.  Patches by Louie Lu, Cheryl Sabella, and Terry
     Jan Reedy.

   - bpo-30303(49): Add _utest option to textview; add new tests.
     Increase coverage to 100%.  Patches by Louie Lu and Terry Jan
     Reedy.

   - bpo-29071(50): IDLE colors f-string prefixes (but not invalid ur
     prefixes).

   - bpo-28572(51): Add 10% to coverage of IDLE’s test_configdialog.
     Update and augment description of the configuration system.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31493

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31488

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31477

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31480

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31421

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31414

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31051

   (8) https://bugs.python.org/issue?@action=redirect&bpo=30617

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31287

   (10) https://bugs.python.org/issue?@action=redirect&bpo=27099

   (11) https://bugs.python.org/issue?@action=redirect&bpo=31206

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31001

   (13) https://bugs.python.org/issue?@action=redirect&bpo=31205

   (14) https://bugs.python.org/issue?@action=redirect&bpo=31130

   (15) https://bugs.python.org/issue?@action=redirect&bpo=31002

   (16) https://bugs.python.org/issue?@action=redirect&bpo=19903

   (17) https://bugs.python.org/issue?@action=redirect&bpo=31083

   (18) https://bugs.python.org/issue?@action=redirect&bpo=31050

   (19) https://bugs.python.org/issue?@action=redirect&bpo=31004

   (20) https://bugs.python.org/issue?@action=redirect&bpo=30781

   (21) https://bugs.python.org/issue?@action=redirect&bpo=31060

   (22) https://bugs.python.org/issue?@action=redirect&bpo=30853

   (23) https://bugs.python.org/issue?@action=redirect&bpo=31003

   (24) https://bugs.python.org/issue?@action=redirect&bpo=30993

   (25) https://bugs.python.org/issue?@action=redirect&bpo=30981

   (26) https://bugs.python.org/issue?@action=redirect&bpo=28523

   (27) https://bugs.python.org/issue?@action=redirect&bpo=30917

   (28) https://bugs.python.org/issue?@action=redirect&bpo=30934

   (29) https://bugs.python.org/issue?@action=redirect&bpo=30913

   (30) https://bugs.python.org/issue?@action=redirect&bpo=30899

   (31) https://bugs.python.org/issue?@action=redirect&bpo=30881

   (32) https://bugs.python.org/issue?@action=redirect&bpo=30851

   (33) https://bugs.python.org/issue?@action=redirect&bpo=30870

   (34) https://bugs.python.org/issue?@action=redirect&bpo=8231

   (35) https://bugs.python.org/issue?@action=redirect&bpo=30779

   (36) https://bugs.python.org/issue?@action=redirect&bpo=30777

   (37) https://bugs.python.org/issue?@action=redirect&bpo=30495

   (38) https://bugs.python.org/issue?@action=redirect&bpo=30723

   (39) https://bugs.python.org/issue?@action=redirect&bpo=30674

   (40) https://bugs.python.org/issue?@action=redirect&bpo=21519

   (41) https://bugs.python.org/issue?@action=redirect&bpo=29910

   (42) https://bugs.python.org/issue?@action=redirect&bpo=30728

   (43) https://bugs.python.org/issue?@action=redirect&bpo=6739

   (44) https://bugs.python.org/issue?@action=redirect&bpo=15786

   (45) https://bugs.python.org/issue?@action=redirect&bpo=25514

   (46) https://bugs.python.org/issue?@action=redirect&bpo=30642

   (47) https://bugs.python.org/issue?@action=redirect&bpo=30495

   (48) https://bugs.python.org/issue?@action=redirect&bpo=30290

   (49) https://bugs.python.org/issue?@action=redirect&bpo=30303

   (50) https://bugs.python.org/issue?@action=redirect&bpo=29071

   (51) https://bugs.python.org/issue?@action=redirect&bpo=28572


File: python.info,  Node: Tools/Demos<43>,  Next: C API<63>,  Prev: IDLE<45>,  Up: Python 3 7 0 alpha 1

1.24.72.9 Tools/Demos
.....................

   - bpo-30983(1): gdb integration commands (py-bt, etc.)  work on
     optimized shared builds now, too.  PEP 523(2) introduced
     _PyEval_EvalFrameDefault which inlines PyEval_EvalFrameEx on
     non-debug shared builds.  This broke the ability to use py-bt,
     py-up, and a few other Python-specific gdb integrations.  The
     problem is fixed by only looking for _PyEval_EvalFrameDefault
     frames in python-gdb.py.  Original patch by Bruno «Polaco»
     Penteado.

   - bpo-29748(3): Added the slice index converter in Argument Clinic.

   - bpo-24037(4): Argument Clinic now uses the converter
     ‘bool(accept={int})’ rather than ‘int’ for semantical booleans.
     This avoids repeating the default value for Python and C and will
     help in converting to ‘bool’ in future.

   - bpo-29367(5): python-gdb.py now supports also ‘method-wrapper’
     (‘wrapperobject’) objects.

   - bpo-28023(6): Fix python-gdb.py didn’t support new dict
     implementation.

   - bpo-15369(7): The pybench and pystone microbenchmark have been
     removed from Tools.  Please use the new Python benchmark suite
     ‘https://github.com/python/pyperformance’ which is more reliable
     and includes a portable version of pybench working on Python 2 and
     Python 3.

   - bpo-28102(8): The zipfile module CLI now prints usage to stderr.
     Patch by Stephen J. Turnbull.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30983

   (2) https://peps.python.org/pep-0523/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29748

   (4) https://bugs.python.org/issue?@action=redirect&bpo=24037

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29367

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28023

   (7) https://bugs.python.org/issue?@action=redirect&bpo=15369

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28102


File: python.info,  Node: C API<63>,  Prev: Tools/Demos<43>,  Up: Python 3 7 0 alpha 1

1.24.72.10 C API
................

   - bpo-31338(1): Added the ‘Py_UNREACHABLE()’ macro for code paths
     which are never expected to be reached.  This and a few other
     useful macros are now documented in the C API manual.

   - bpo-30832(2): Remove own implementation for thread-local storage.
     CPython has provided the own implementation for thread-local
     storage (TLS) on Python/thread.c, it’s used in the case which a
     platform has not supplied native TLS. However, currently all
     supported platforms (Windows and pthreads) have provided native TLS
     and defined the Py_HAVE_NATIVE_TLS macro with unconditional in any
     case.

   - bpo-30708(3): PyUnicode_AsWideCharString() now raises a ValueError
     if the second argument is NULL and the wchar_t* string contains
     null characters.

   - bpo-16500(4): Deprecate PyOS_AfterFork() and add PyOS_BeforeFork(),
     PyOS_AfterFork_Parent() and PyOS_AfterFork_Child().

   - bpo-6532(5): The type of results of PyThread_start_new_thread() and
     PyThread_get_thread_ident(), and the id parameter of
     PyThreadState_SetAsyncExc() changed from «long» to «unsigned long».

   - bpo-27867(6): Function PySlice_GetIndicesEx() is deprecated and
     replaced with a macro if Py_LIMITED_API is not set or set to the
     value between 0x03050400 and 0x03060000 (not including) or
     0x03060100 or higher.  Added functions PySlice_Unpack() and
     PySlice_AdjustIndices().

   - bpo-29083(7): Fixed the declaration of some public API functions.
     PyArg_VaParse() and PyArg_VaParseTupleAndKeywords() were not
     available in limited API. PyArg_ValidateKeywordArguments(),
     PyArg_UnpackTuple() and Py_BuildValue() were not available in
     limited API of version < 3.3 when PY_SSIZE_T_CLEAN is defined.

   - bpo-28769(8): The result of PyUnicode_AsUTF8AndSize() and
     PyUnicode_AsUTF8() is now of type ‘const char *’ rather of ‘char
     *’.

   - bpo-29058(9): All stable API extensions added after Python 3.2 are
     now available only when Py_LIMITED_API is set to the PY_VERSION_HEX
     value of the minimum Python version supporting this API.

   - bpo-28822(10): The index parameters 'start' and 'end' of
     PyUnicode_FindChar() are now adjusted to behave like
     ‘str[start:end]’.

   - bpo-28808(11): PyUnicode_CompareWithASCIIString() now never raises
     exceptions.

   - bpo-28761(12): The fields name and doc of structures PyMemberDef,
     PyGetSetDef, PyStructSequence_Field, PyStructSequence_Desc, and
     wrapperbase are now of type ‘const char *’ rather of ‘char *’.

   - bpo-28748(13): Private variable _Py_PackageContext is now of type
     ‘const char *’ rather of ‘char *’.

   - bpo-19569(14): Compiler warnings are now emitted if use most of
     deprecated functions.

   - bpo-28426(15): Deprecated undocumented functions
     PyUnicode_AsEncodedObject(), PyUnicode_AsDecodedObject(),
     PyUnicode_AsDecodedUnicode() and PyUnicode_AsEncodedUnicode().

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31338

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30832

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30708

   (4) https://bugs.python.org/issue?@action=redirect&bpo=16500

   (5) https://bugs.python.org/issue?@action=redirect&bpo=6532

   (6) https://bugs.python.org/issue?@action=redirect&bpo=27867

   (7) https://bugs.python.org/issue?@action=redirect&bpo=29083

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28769

   (9) https://bugs.python.org/issue?@action=redirect&bpo=29058

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28822

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28808

   (12) https://bugs.python.org/issue?@action=redirect&bpo=28761

   (13) https://bugs.python.org/issue?@action=redirect&bpo=28748

   (14) https://bugs.python.org/issue?@action=redirect&bpo=19569

   (15) https://bugs.python.org/issue?@action=redirect&bpo=28426


File: python.info,  Node: Python 3 6 6 final,  Next: Python 3 6 6 release candidate 1,  Prev: Python 3 7 0 alpha 1,  Up: Changelog

1.24.73 Python 3.6.6 final
--------------------------

'Release date: 2018-06-27'

There were no new changes in version 3.6.6.


File: python.info,  Node: Python 3 6 6 release candidate 1,  Next: Python 3 6 5 final,  Prev: Python 3 6 6 final,  Up: Changelog

1.24.74 Python 3.6.6 release candidate 1
----------------------------------------

'Release date: 2018-06-11'

* Menu:

* Core and Builtins: Core and Builtins<169>.
* Library: Library<173>.
* Documentation: Documentation<66>.
* Tests: Tests<63>.
* Build: Build<71>.
* Windows: Windows<63>.
* macOS: macOS<48>.
* IDLE: IDLE<46>.
* Tools/Demos: Tools/Demos<44>.
* C API: C API<64>.


File: python.info,  Node: Core and Builtins<169>,  Next: Library<173>,  Up: Python 3 6 6 release candidate 1

1.24.74.1 Core and Builtins
...........................

   - bpo-33786(1): Fix asynchronous generators to handle GeneratorExit
     in athrow() correctly

   - bpo-30654(2): Fixed reset of the SIGINT handler to SIG_DFL on
     interpreter shutdown even when there was a custom handler set
     previously.  Patch by Philipp Kerling.

   - bpo-33622(3): Fixed a leak when the garbage collector fails to add
     an object with the ‘__del__’ method or referenced by it into the
     *note gc.garbage: 13c9. list.  *note PyGC_Collect(): b87. can now
     be called when an exception is set and preserves it.

   - bpo-31849(4): Fix signed/unsigned comparison warning in pyhash.c.

   - bpo-33391(5): Fix a leak in set_symmetric_difference().

   - bpo-28055(6): Fix unaligned accesses in siphash24().  Patch by Rolf
     Eike Beer.

   - bpo-33231(7): Fix potential memory leak in ‘normalizestring()’.

   - bpo-29922(8): Improved error messages in “async with” when
     ‘__aenter__()’ or ‘__aexit__()’ return non-awaitable object.

   - bpo-33199(9): Fix ‘ma_version_tag’ in dict implementation is
     uninitialized when copying from key-sharing dict.

   - bpo-33041(10): Fixed jumping when the function contains an ‘async
     for’ loop.

   - bpo-32282(11): Fix an unnecessary ifdef in the include of
     VersionHelpers.h in socketmodule on Windows.

   - bpo-21983(12): Fix a crash in ‘ctypes.cast()’ in case the type
     argument is a ctypes structured data type.  Patch by Eryk Sun and
     Oren Milman.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33786

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30654

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33622

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31849

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33391

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28055

   (7) https://bugs.python.org/issue?@action=redirect&bpo=33231

   (8) https://bugs.python.org/issue?@action=redirect&bpo=29922

   (9) https://bugs.python.org/issue?@action=redirect&bpo=33199

   (10) https://bugs.python.org/issue?@action=redirect&bpo=33041

   (11) https://bugs.python.org/issue?@action=redirect&bpo=32282

   (12) https://bugs.python.org/issue?@action=redirect&bpo=21983


File: python.info,  Node: Library<173>,  Next: Documentation<66>,  Prev: Core and Builtins<169>,  Up: Python 3 6 6 release candidate 1

1.24.74.2 Library
.................

   - bpo-30167(1): Prevent site.main() exception if PYTHONSTARTUP is
     set.  Patch by Steve Weber.

   - bpo-33812(2): Datetime instance d with non-None tzinfo, but with
     d.tzinfo.utcoffset(d) returning None is now treated as naive by the
     astimezone() method.

   - bpo-30805(3): Avoid race condition with debug logging

   - bpo-33767(4): The concatenation (‘+’) and repetition (‘*’) sequence
     operations now raise *note TypeError: 198. instead of *note
     SystemError: 796. when performed on *note mmap.mmap: 51a. objects.
     Patch by Zackery Spytz.

   - bpo-32684(5): Fix gather to propagate cancellation of itself even
     with return_exceptions.

   - bpo-33674(6): Fix a race condition in SSLProtocol.connection_made()
     of asyncio.sslproto: start immediately the handshake instead of
     using call_soon().  Previously, data_received() could be called
     before the handshake started, causing the handshake to hang or
     fail.

   - bpo-31647(7): Fixed bug where calling write_eof() on a
     _SelectorSocketTransport after it’s already closed raises
     AttributeError.

   - bpo-33672(8): Fix Task.__repr__ crash with Cython’s bogus
     coroutines

   - bpo-33469(9): Fix RuntimeError after closing loop that used
     run_in_executor

   - bpo-11874(10): Use a better regex when breaking usage into
     wrappable parts.  Avoids bogus assertion errors from custom metavar
     strings.

   - bpo-30877(11): Fixed a bug in the Python implementation of the JSON
     decoder that prevented the cache of parsed strings from clearing
     after finishing the decoding.  Based on patch by c-fos.

   - bpo-33548(12): tempfile._candidate_tempdir_list should consider
     common TEMP locations

   - bpo-33542(13): Prevent ‘uuid.get_node’ from using a DUID instead of
     a MAC on Windows.  Patch by Zvi Effron

   - bpo-26819(14): Fix race condition with
     ‘ReadTransport.resume_reading’ in Windows proactor event loop.

   - bpo-28556(15): Minor fixes in typing module: add annotations to
     ‘NamedTuple.__new__’, pass ‘*args’ and ‘**kwds’ in
     ‘Generic.__new__’.  Original PRs by Paulius Šarka and Chad
     Dombrova.

   - bpo-20087(16): Updated alias mapping with glibc 2.27 supported
     locales.

   - bpo-33422(17): Fix trailing quotation marks getting deleted when
     looking up byte/string literals on pydoc.  Patch by Andrés Delfino.

   - bpo-33197(18): Update error message when constructing invalid
     inspect.Parameters Patch by Donghee Na.

   - bpo-33383(19): Fixed crash in the get() method of the *note
     dbm.ndbm: 38. database object when it is called with a single
     argument.

   - bpo-33329(20): Fix multiprocessing regression on newer glibcs

   - bpo-991266(21): Fix quoting of the ‘Comment’ attribute of *note
     http.cookies.SimpleCookie: 1e0c.

   - bpo-33131(22): Upgrade bundled version of pip to 10.0.1.

   - bpo-33308(23): Fixed a crash in the ‘parser’ module when converting
     an ST object to a tree of tuples or lists with ‘line_info=False’
     and ‘col_info=True’.

   - bpo-33263(24): Fix FD leak in ‘_SelectorSocketTransport’ Patch by
     Vlad Starostin.

   - bpo-33256(25): Fix display of ‘<module>’ call in the html produced
     by ‘cgitb.html()’.  Patch by Stéphane Blondon.

   - bpo-33203(26): ‘random.Random.choice()’ now raises ‘IndexError’ for
     empty sequences consistently even when called from subclasses
     without a ‘getrandbits()’ implementation.

   - bpo-33224(27): Update difflib.mdiff() for PEP 479(28).  Convert an
     uncaught StopIteration in a generator into a return-statement.

   - bpo-33209(29): End framing at the end of C implementation of *note
     pickle.Pickler.dump(): 1e0d.

   - bpo-32861(30): The urllib.robotparser’s ‘__str__’ representation
     now includes wildcard entries and the «Crawl-delay» and
     «Request-rate» fields.  Patch by Michael Lazar.

   - bpo-33096(31): Allow ttk.Treeview.insert to insert iid that has a
     false boolean value.  Note iid=0 and iid=False would be same.
     Patch by Garvit Khatri.

   - bpo-33127(32): The ssl module now compiles with LibreSSL 2.7.1.

   - bpo-33021(33): Release the GIL during fstat() calls, avoiding hang
     of all threads when calling mmap.mmap(), os.urandom(), and
     random.seed().  Patch by Nir Soffer.

   - bpo-27683(34): Fix a regression in *note ipaddress: 84. that result
     of ‘hosts()’ is empty when the network is constructed by a tuple
     containing an integer mask and only 1 bit left for addresses.

   - bpo-32844(35): Fix wrong redirection of a low descriptor (0 or 1)
     to stderr in subprocess if another low descriptor is closed.

   - bpo-31908(36): Fix output of cover files for ‘trace’ module
     command-line tool.  Previously emitted cover files only when
     ‘--missing’ option was used.  Patch by Michael Selik.

   - bpo-31457(37): If nested log adapters are used, the inner
     ‘process()’ methods are no longer omitted.

   - bpo-16865(38): Support arrays >=2GiB in *note ctypes: 2e.  Patch by
     Segev Finer.

   - bpo-31238(39): pydoc: the stop() method of the private ServerThread
     class now waits until DocServer.serve_until_quit() completes and
     then explicitly sets its docserver attribute to None to break a
     reference cycle.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30167

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33812

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30805

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33767

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32684

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33674

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31647

   (8) https://bugs.python.org/issue?@action=redirect&bpo=33672

   (9) https://bugs.python.org/issue?@action=redirect&bpo=33469

   (10) https://bugs.python.org/issue?@action=redirect&bpo=11874

   (11) https://bugs.python.org/issue?@action=redirect&bpo=30877

   (12) https://bugs.python.org/issue?@action=redirect&bpo=33548

   (13) https://bugs.python.org/issue?@action=redirect&bpo=33542

   (14) https://bugs.python.org/issue?@action=redirect&bpo=26819

   (15) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (16) https://bugs.python.org/issue?@action=redirect&bpo=20087

   (17) https://bugs.python.org/issue?@action=redirect&bpo=33422

   (18) https://bugs.python.org/issue?@action=redirect&bpo=33197

   (19) https://bugs.python.org/issue?@action=redirect&bpo=33383

   (20) https://bugs.python.org/issue?@action=redirect&bpo=33329

   (21) https://bugs.python.org/issue?@action=redirect&bpo=991266

   (22) https://bugs.python.org/issue?@action=redirect&bpo=33131

   (23) https://bugs.python.org/issue?@action=redirect&bpo=33308

   (24) https://bugs.python.org/issue?@action=redirect&bpo=33263

   (25) https://bugs.python.org/issue?@action=redirect&bpo=33256

   (26) https://bugs.python.org/issue?@action=redirect&bpo=33203

   (27) https://bugs.python.org/issue?@action=redirect&bpo=33224

   (28) https://peps.python.org/pep-0479/

   (29) https://bugs.python.org/issue?@action=redirect&bpo=33209

   (30) https://bugs.python.org/issue?@action=redirect&bpo=32861

   (31) https://bugs.python.org/issue?@action=redirect&bpo=33096

   (32) https://bugs.python.org/issue?@action=redirect&bpo=33127

   (33) https://bugs.python.org/issue?@action=redirect&bpo=33021

   (34) https://bugs.python.org/issue?@action=redirect&bpo=27683

   (35) https://bugs.python.org/issue?@action=redirect&bpo=32844

   (36) https://bugs.python.org/issue?@action=redirect&bpo=31908

   (37) https://bugs.python.org/issue?@action=redirect&bpo=31457

   (38) https://bugs.python.org/issue?@action=redirect&bpo=16865

   (39) https://bugs.python.org/issue?@action=redirect&bpo=31238


File: python.info,  Node: Documentation<66>,  Next: Tests<63>,  Prev: Library<173>,  Up: Python 3 6 6 release candidate 1

1.24.74.3 Documentation
.......................

   - bpo-33503(1): Fix broken pypi link

   - bpo-33421(2): Add missing documentation for
     ‘typing.AsyncContextManager’.

   - bpo-33378(3): Add Korean language switcher for
     ‘https://docs.python.org/3/’

   - bpo-33276(4): Clarify that the ‘__path__’ attribute on modules
     cannot be just any value.

   - bpo-33201(5): Modernize documentation for writing C extension
     types.

   - bpo-33195(6): Deprecate ‘Py_UNICODE’ usage in ‘c-api/arg’ document.
     ‘Py_UNICODE’ related APIs are deprecated since Python 3.3, but it
     is missed in the document.

   - bpo-33126(7): Document PyBuffer_ToContiguous().

   - bpo-27212(8): Modify documentation for the ‘islice()’ recipe to
     consume initial values up to the start index.

   - bpo-28247(9): Update *note zipapp: 136. documentation to describe
     how to make standalone applications.

   - bpo-18802(10): Documentation changes for ipaddress.  Patch by Jon
     Foster and Berker Peksag.

   - bpo-27428(11): Update documentation to clarify that
     ‘WindowsRegistryFinder’ implements ‘MetaPathFinder’.  (Patch by
     Himanshu Lakhara)

   - bpo-8243(12): Add a note about curses.addch and curses.addstr
     exception behavior when writing outside a window, or pad.

   - bpo-31432(13): Clarify meaning of CERT_NONE, CERT_OPTIONAL, and
     CERT_REQUIRED flags for ssl.SSLContext.verify_mode.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33503

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33421

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33378

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33276

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33201

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33195

   (7) https://bugs.python.org/issue?@action=redirect&bpo=33126

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27212

   (9) https://bugs.python.org/issue?@action=redirect&bpo=28247

   (10) https://bugs.python.org/issue?@action=redirect&bpo=18802

   (11) https://bugs.python.org/issue?@action=redirect&bpo=27428

   (12) https://bugs.python.org/issue?@action=redirect&bpo=8243

   (13) https://bugs.python.org/issue?@action=redirect&bpo=31432


File: python.info,  Node: Tests<63>,  Next: Build<71>,  Prev: Documentation<66>,  Up: Python 3 6 6 release candidate 1

1.24.74.4 Tests
...............

   - bpo-33655(1): Ignore test_posix_fallocate failures on BSD platforms
     that might be due to running on ZFS.

   - bpo-19417(2): Add test_bdb.py.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33655

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19417


File: python.info,  Node: Build<71>,  Next: Windows<63>,  Prev: Tests<63>,  Up: Python 3 6 6 release candidate 1

1.24.74.5 Build
...............

   - bpo-5755(1): Move ‘-Wstrict-prototypes’ option to ‘CFLAGS_NODIST’
     from ‘OPT’.  This option emitted annoying warnings when building
     extension modules written in C++.

   - bpo-33614(2): Ensures module definition files for the stable ABI on
     Windows are correctly regenerated.

   - bpo-33522(3): Enable CI builds on Visual Studio Team Services at
     ‘https://python.visualstudio.com/cpython’

   - bpo-33012(4): Add ‘-Wno-cast-function-type’ for gcc 8 for silencing
     warnings about function casts like casting to PyCFunction in method
     definition lists.

   - bpo-33394(5): Enable the verbose build for extension modules, when
     GNU make is passed macros on the command line.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5755

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33614

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33522

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33012

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33394


File: python.info,  Node: Windows<63>,  Next: macOS<48>,  Prev: Build<71>,  Up: Python 3 6 6 release candidate 1

1.24.74.6 Windows
.................

   - bpo-33184(1): Update Windows installer to OpenSSL 1.0.2o.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33184


File: python.info,  Node: macOS<48>,  Next: IDLE<46>,  Prev: Windows<63>,  Up: Python 3 6 6 release candidate 1

1.24.74.7 macOS
...............

   - bpo-33184(1): Update macOS installer build to use OpenSSL 1.0.2o.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33184


File: python.info,  Node: IDLE<46>,  Next: Tools/Demos<44>,  Prev: macOS<48>,  Up: Python 3 6 6 release candidate 1

1.24.74.8 IDLE
..............

   - bpo-33656(1): On Windows, add API call saying that tk scales for
     DPI. On Windows 8.1+ or 10, with DPI compatibility properties of
     the Python binary unchanged, and a monitor resolution greater than
     96 DPI, this should make text and lines sharper.  It should
     otherwise have no effect.

   - bpo-33768(2): Clicking on a context line moves that line to the top
     of the editor window.

   - bpo-33763(3): IDLE: Use read-only text widget for code context
     instead of label widget.

   - bpo-33664(4): Scroll IDLE editor text by lines.  Previously, the
     mouse wheel and scrollbar slider moved text by a fixed number of
     pixels, resulting in partial lines at the top of the editor box.
     The change also applies to the shell and grep output windows, but
     not to read-only text views.

   - bpo-33679(5): Enable theme-specific color configuration for Code
     Context.  Use the Highlights tab to see the setting for built-in
     themes or add settings to custom themes.

   - bpo-33642(6): Display up to maxlines non-blank lines for Code
     Context.  If there is no current context, show a single blank line.

   - bpo-33628(7): IDLE: Cleanup codecontext.py and its test.

   - bpo-33564(8): IDLE’s code context now recognizes async as a block
     opener.

   - bpo-29706(9): IDLE now colors async and await as keywords in 3.6.
     They become full keywords in 3.7.

   - bpo-21474(10): Update word/identifier definition from ascii to
     unicode.  In text and entry boxes, this affects selection by
     double-click, movement left/right by control-left/right, and
     deletion left/right by control-BACKSPACE/DEL.

   - bpo-33204(11): IDLE: consistently color invalid string prefixes.  A
     “u” string prefix cannot be paired with either “r” or “f”.
     Consistently color as much of the prefix, starting at the right, as
     is valid.  Revise and extend colorizer test.

   - bpo-32831(12): Add docstrings and tests for codecontext.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33656

   (2) https://bugs.python.org/issue?@action=redirect&bpo=33768

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33763

   (4) https://bugs.python.org/issue?@action=redirect&bpo=33664

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33679

   (6) https://bugs.python.org/issue?@action=redirect&bpo=33642

   (7) https://bugs.python.org/issue?@action=redirect&bpo=33628

   (8) https://bugs.python.org/issue?@action=redirect&bpo=33564

   (9) https://bugs.python.org/issue?@action=redirect&bpo=29706

   (10) https://bugs.python.org/issue?@action=redirect&bpo=21474

   (11) https://bugs.python.org/issue?@action=redirect&bpo=33204

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32831


File: python.info,  Node: Tools/Demos<44>,  Next: C API<64>,  Prev: IDLE<46>,  Up: Python 3 6 6 release candidate 1

1.24.74.9 Tools/Demos
.....................

   - bpo-33189(1): ‘pygettext.py’ now recognizes only literal strings as
     docstrings and translatable strings, and rejects bytes literals and
     f-string expressions.

   - bpo-31920(2): Fixed handling directories as arguments in the
     ‘pygettext’ script.  Based on patch by Oleg Krasnikov.

   - bpo-29673(3): Fix pystackv and pystack gdbinit macros.

   - bpo-32885(4): Add an ‘-n’ flag for ‘Tools/scripts/pathfix.py’ to
     disable automatic backup creation (files with ‘~’ suffix).

   - bpo-31583(5): Fix 2to3 for using with –add-suffix option but
     without –output-dir option for relative path to files in current
     directory.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33189

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31920

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29673

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32885

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31583


File: python.info,  Node: C API<64>,  Prev: Tools/Demos<44>,  Up: Python 3 6 6 release candidate 1

1.24.74.10 C API
................

   - bpo-32374(1): Document that m_traverse for multi-phase initialized
     modules can be called with m_state=NULL, and add a sanity check

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32374


File: python.info,  Node: Python 3 6 5 final,  Next: Python 3 6 5 release candidate 1,  Prev: Python 3 6 6 release candidate 1,  Up: Changelog

1.24.75 Python 3.6.5 final
--------------------------

'Release date: 2018-03-28'

* Menu:

* Tests: Tests<64>.
* Build: Build<72>.


File: python.info,  Node: Tests<64>,  Next: Build<72>,  Up: Python 3 6 5 final

1.24.75.1 Tests
...............

   - bpo-32872(1): Avoid regrtest compatibility issue with namespace
     packages.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32872


File: python.info,  Node: Build<72>,  Prev: Tests<64>,  Up: Python 3 6 5 final

1.24.75.2 Build
...............

   - bpo-33163(1): Upgrade pip to 9.0.3 and setuptools to v39.0.1.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33163


File: python.info,  Node: Python 3 6 5 release candidate 1,  Next: Python 3 6 4 final,  Prev: Python 3 6 5 final,  Up: Changelog

1.24.76 Python 3.6.5 release candidate 1
----------------------------------------

'Release date: 2018-03-13'

* Menu:

* Security: Security<50>.
* Core and Builtins: Core and Builtins<170>.
* Library: Library<174>.
* Documentation: Documentation<67>.
* Tests: Tests<65>.
* Build: Build<73>.
* Windows: Windows<64>.
* macOS: macOS<49>.
* IDLE: IDLE<47>.
* Tools/Demos: Tools/Demos<45>.
* C API: C API<65>.


File: python.info,  Node: Security<50>,  Next: Core and Builtins<170>,  Up: Python 3 6 5 release candidate 1

1.24.76.1 Security
..................

   - bpo-33001(1): Minimal fix to prevent buffer overrun in os.symlink
     on Windows

   - bpo-32981(2): Regexes in difflib and poplib were vulnerable to
     catastrophic backtracking.  These regexes formed potential DOS
     vectors (REDOS). They have been refactored.  This resolves CVE
     2018-1060(3) and CVE 2018-1061(4).  Patch by Jamie Davis.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33001

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32981

   (3) https://www.cve.org/CVERecord?id=CVE-2018-1060

   (4) https://www.cve.org/CVERecord?id=CVE-2018-1061


File: python.info,  Node: Core and Builtins<170>,  Next: Library<174>,  Prev: Security<50>,  Up: Python 3 6 5 release candidate 1

1.24.76.2 Core and Builtins
...........................

   - bpo-33026(1): Fixed jumping out of «with» block by setting
     f_lineno.

   - bpo-17288(2): Prevent jumps from “return” and “exception” trace
     events.

   - bpo-32889(3): Update Valgrind suppression list to account for the
     rename of ‘Py_ADDRESS_IN_RANG’ to ‘address_in_range’.

   - bpo-32650(4): Pdb and other debuggers dependent on bdb.py will
     correctly step over (next command) native coroutines.  Patch by
     Pablo Galindo.

   - bpo-32685(5): Improve suggestion when the Python 2 form of print
     statement is either present on the same line as the header of a
     compound statement or else terminated by a semi-colon instead of a
     newline.  Patch by Nitish Chandra.

   - bpo-32583(6): Fix possible crashing in builtin Unicode decoders
     caused by write out-of-bound errors when using customized decode
     error handlers.

   - bpo-26163(7): Improved frozenset() hash to create more distinct
     hash values when faced with datasets containing many similar
     values.

   - bpo-27169(8): The ‘__debug__’ constant is now optimized out at
     compile time.  This fixes also bpo-22091(9).

   - bpo-32329(10): ‘sys.flags.hash_randomization’ is now properly set
     to 0 when hash randomization is turned off by ‘PYTHONHASHSEED=0’.

   - bpo-30416(11): The optimizer is now protected from spending much
     time doing complex calculations and consuming much memory for
     creating large constants in constant folding.

   - bpo-18533(12): ‘repr()’ on a dict containing its own ‘values()’ or
     ‘items()’ no longer raises ‘RecursionError’; OrderedDict similarly.
     Instead, use ‘...’, as for other recursive structures.  Patch by
     Ben North.

   - bpo-32028(13): Leading whitespace is now correctly ignored when
     generating suggestions for converting Py2 print statements to Py3
     builtin print function calls.  Patch by Sanyam Khurana.

   - bpo-32137(14): The repr of deeply nested dict now raises a
     RecursionError instead of crashing due to a stack overflow.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33026

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17288

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32889

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32650

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32685

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32583

   (7) https://bugs.python.org/issue?@action=redirect&bpo=26163

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27169

   (9) https://bugs.python.org/issue?@action=redirect&bpo=22091

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32329

   (11) https://bugs.python.org/issue?@action=redirect&bpo=30416

   (12) https://bugs.python.org/issue?@action=redirect&bpo=18533

   (13) https://bugs.python.org/issue?@action=redirect&bpo=32028

   (14) https://bugs.python.org/issue?@action=redirect&bpo=32137


File: python.info,  Node: Library<174>,  Next: Documentation<67>,  Prev: Core and Builtins<170>,  Up: Python 3 6 5 release candidate 1

1.24.76.3 Library
.................

   - bpo-33064(1): lib2to3 now properly supports trailing commas after
     ‘*args’ and ‘**kwargs’ in function signatures.

   - bpo-31804(2): Avoid failing in multiprocessing.Process if the
     standard streams are closed or None at exit.

   - bpo-33037(3): Skip sending/receiving data after SSL transport
     closing.

   - bpo-30353(4): Fix ctypes pass-by-value for structs on 64-bit
     Cygwin/MinGW.

   - bpo-33009(5): Fix inspect.signature() for single-parameter
     partialmethods.

   - bpo-32969(6): Expose several missing constants in zlib and fix
     corresponding documentation.

   - bpo-32713(7): Fixed tarfile.itn handling of out-of-bounds float
     values.  Patch by Joffrey Fuhrer.

   - bpo-30622(8): The ssl module now detects missing NPN support in
     LibreSSL.

   - bpo-32922(9): dbm.open() now encodes filename with the filesystem
     encoding rather than default encoding.

   - bpo-32859(10): In ‘os.dup2’, don’t check every call whether the
     ‘dup3’ syscall exists or not.

   - bpo-21060(11): Rewrite confusing message from setup.py upload from
     «No dist file created in earlier command» to the more helpful «Must
     create and upload files in one command».

   - bpo-32857(12): In *note tkinter: f6, ‘after_cancel(None)’ now
     raises a *note ValueError: 2ec. instead of canceling the first
     scheduled function.  Patch by Cheryl Sabella.

   - bpo-32852(13): Make sure sys.argv remains as a list when running
     trace.

   - bpo-32841(14): Fixed ‘asyncio.Condition’ issue which silently
     ignored cancellation after notifying and cancelling a conditional
     lock.  Patch by Bar Harel.

   - bpo-31787(15): Fixed refleaks of ‘__init__()’ methods in various
     modules.  (Contributed by Oren Milman)

   - bpo-30157(16): Fixed guessing quote and delimiter in
     csv.Sniffer.sniff() when only the last field is quoted.  Patch by
     Jake Davis.

   - bpo-32394(17): socket: Remove TCP_FASTOPEN, TCP_KEEPCNT flags on
     older version Windows during run-time.

   - bpo-32777(18): Fix a rare but potential pre-exec child process
     deadlock in subprocess on POSIX systems when marking file
     descriptors inheritable on exec in the child process.  This bug
     appears to have been introduced in 3.4.

   - bpo-32647(19): The ctypes module used to depend on indirect linking
     for dlopen.  The shared extension is now explicitly linked against
     libdl on platforms with dl.

   - bpo-32734(20): Fixed ‘asyncio.Lock()’ safety issue which allowed
     acquiring and locking the same lock multiple times, without it
     being free.  Patch by Bar Harel.

   - bpo-32727(21): Do not include name field in SMTP envelope from
     address.  Patch by Stéphane Wirtel

   - bpo-27931(22): Fix email address header parsing error when the
     username is an empty quoted string.  Patch by Xiang Zhang.

   - bpo-32304(23): distutils” upload command no longer corrupts tar
     files ending with a CR byte, and no longer tries to convert CR to
     CRLF in any of the upload text fields.

   - bpo-32502(24): uuid.uuid1 no longer raises an exception if a 64-bit
     hardware address is encountered.

   - bpo-31848(25): Fix the error handling in Aifc_read.initfp() when
     the SSND chunk is not found.  Patch by Zackery Spytz.

   - bpo-32555(26): On FreeBSD and Solaris, os.strerror() now always
     decode the byte string from the current locale encoding, rather
     than using ASCII/surrogateescape in some cases.

   - bpo-32521(27): The nis module is now compatible with new libnsl and
     headers location.

   - bpo-32473(28): Improve ABCMeta._dump_registry() output readability

   - bpo-32521(29): glibc has removed Sun RPC. Use replacement libtirpc
     headers and library in nis module.

   - bpo-32228(30): Ensure that ‘truncate()’ preserves the file position
     (as reported by ‘tell()’) after writes longer than the buffer size.

   - bpo-26133(31): Don’t unsubscribe signals in asyncio UNIX event loop
     on interpreter shutdown.

   - bpo-32185(32): The SSL module no longer sends IP addresses in SNI
     TLS extension on platforms with OpenSSL 1.0.2+ or inet_pton.

   - bpo-32323(33): *note urllib.parse.urlsplit(): f3c. does not convert
     zone-id (scope) to lower case for scoped IPv6 addresses in
     hostnames now.

   - bpo-32302(34): Fix bdist_wininst of distutils for CRT v142: it
     binary compatible with CRT v140.

   - bpo-32255(35): A single empty field is now always quoted when
     written into a CSV file.  This allows to distinguish an empty row
     from a row consisting of a single empty field.  Patch by Licht
     Takeuchi.

   - bpo-32277(36): Raise ‘NotImplementedError’ instead of ‘SystemError’
     on platforms where ‘chmod(..., follow_symlinks=False)’ is not
     supported.  Patch by Anthony Sottile.

   - bpo-32199(37): The getnode() ip getter now uses “ip link” instead
     of “ip link list”.

   - bpo-27456(38): Ensure TCP_NODELAY is set on Linux.  Tests by Victor
     Stinner.

   - bpo-31900(39): The *note locale.localeconv(): dfa. function now
     sets temporarily the ‘LC_CTYPE’ locale to the ‘LC_NUMERIC’ locale
     to decode ‘decimal_point’ and ‘thousands_sep’ byte strings if they
     are non-ASCII or longer than 1 byte, and the ‘LC_NUMERIC’ locale is
     different than the ‘LC_CTYPE’ locale.  This temporary change
     affects other threads.  Same change for the *note str.format():
     834. method when formatting a number (*note int: 19b, *note float:
     196, *note float: 196. and subclasses) with the ‘n’ type (ex:
     ‘'{:n}'.format(1234)’).

   - bpo-31802(40): Importing native path module (‘posixpath’, ‘ntpath’)
     now works even if the ‘os’ module still is not imported.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33064

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31804

   (3) https://bugs.python.org/issue?@action=redirect&bpo=33037

   (4) https://bugs.python.org/issue?@action=redirect&bpo=30353

   (5) https://bugs.python.org/issue?@action=redirect&bpo=33009

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32969

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32713

   (8) https://bugs.python.org/issue?@action=redirect&bpo=30622

   (9) https://bugs.python.org/issue?@action=redirect&bpo=32922

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32859

   (11) https://bugs.python.org/issue?@action=redirect&bpo=21060

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32857

   (13) https://bugs.python.org/issue?@action=redirect&bpo=32852

   (14) https://bugs.python.org/issue?@action=redirect&bpo=32841

   (15) https://bugs.python.org/issue?@action=redirect&bpo=31787

   (16) https://bugs.python.org/issue?@action=redirect&bpo=30157

   (17) https://bugs.python.org/issue?@action=redirect&bpo=32394

   (18) https://bugs.python.org/issue?@action=redirect&bpo=32777

   (19) https://bugs.python.org/issue?@action=redirect&bpo=32647

   (20) https://bugs.python.org/issue?@action=redirect&bpo=32734

   (21) https://bugs.python.org/issue?@action=redirect&bpo=32727

   (22) https://bugs.python.org/issue?@action=redirect&bpo=27931

   (23) https://bugs.python.org/issue?@action=redirect&bpo=32304

   (24) https://bugs.python.org/issue?@action=redirect&bpo=32502

   (25) https://bugs.python.org/issue?@action=redirect&bpo=31848

   (26) https://bugs.python.org/issue?@action=redirect&bpo=32555

   (27) https://bugs.python.org/issue?@action=redirect&bpo=32521

   (28) https://bugs.python.org/issue?@action=redirect&bpo=32473

   (29) https://bugs.python.org/issue?@action=redirect&bpo=32521

   (30) https://bugs.python.org/issue?@action=redirect&bpo=32228

   (31) https://bugs.python.org/issue?@action=redirect&bpo=26133

   (32) https://bugs.python.org/issue?@action=redirect&bpo=32185

   (33) https://bugs.python.org/issue?@action=redirect&bpo=32323

   (34) https://bugs.python.org/issue?@action=redirect&bpo=32302

   (35) https://bugs.python.org/issue?@action=redirect&bpo=32255

   (36) https://bugs.python.org/issue?@action=redirect&bpo=32277

   (37) https://bugs.python.org/issue?@action=redirect&bpo=32199

   (38) https://bugs.python.org/issue?@action=redirect&bpo=27456

   (39) https://bugs.python.org/issue?@action=redirect&bpo=31900

   (40) https://bugs.python.org/issue?@action=redirect&bpo=31802


File: python.info,  Node: Documentation<67>,  Next: Tests<65>,  Prev: Library<174>,  Up: Python 3 6 5 release candidate 1

1.24.76.4 Documentation
.......................

   - bpo-17232(1): Clarify docs for -O and -OO. Patch by Terry Reedy.

   - bpo-32800(2): Update link to w3c doc for xml default namespaces.

   - bpo-8722(3): Document ‘__getattr__()’ behavior when property
     ‘get()’ method raises *note AttributeError: 5f0.

   - bpo-32614(4): Modify RE examples in documentation to use raw
     strings to prevent *note DeprecationWarning: 1a3. and add text to
     REGEX HOWTO to highlight the deprecation.

   - bpo-31972(5): Improve docstrings for ‘pathlib.PurePath’ subclasses.

   - bpo-17799(6): Explain real behaviour of sys.settrace and
     sys.setprofile and their C-API counterparts regarding which type of
     events are received in each function.  Patch by Pablo Galindo
     Salgado.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=17232

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32800

   (3) https://bugs.python.org/issue?@action=redirect&bpo=8722

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32614

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31972

   (6) https://bugs.python.org/issue?@action=redirect&bpo=17799


File: python.info,  Node: Tests<65>,  Next: Build<73>,  Prev: Documentation<67>,  Up: Python 3 6 5 release candidate 1

1.24.76.5 Tests
...............

   - bpo-32517(1): Fix failing ‘test_asyncio’ on macOS 10.12.2+ due to
     transport of ‘KqueueSelector’ loop was not being closed.

   - bpo-32721(2): Fix test_hashlib to not fail if the _md5 module is
     not built.

   - bpo-32252(3): Fix faulthandler_suppress_crash_report() used to
     prevent core dump files when testing crashes.  getrlimit() returns
     zero on success.

   - bpo-31518(4): Debian Unstable has disabled TLS 1.0 and 1.1 for
     SSLv23_METHOD().  Change TLS/SSL protocol of some tests to
     PROTOCOL_TLS or PROTOCOL_TLSv1_2 to make them pass on Debian.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32517

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32721

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32252

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31518


File: python.info,  Node: Build<73>,  Next: Windows<64>,  Prev: Tests<65>,  Up: Python 3 6 5 release candidate 1

1.24.76.6 Build
...............

   - bpo-32635(1): Fix segfault of the crypt module when libxcrypt is
     provided instead of libcrypt at the system.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32635


File: python.info,  Node: Windows<64>,  Next: macOS<49>,  Prev: Build<73>,  Up: Python 3 6 5 release candidate 1

1.24.76.7 Windows
.................

   - bpo-33016(1): Fix potential use of uninitialized memory in
     nt._getfinalpathname

   - bpo-32903(2): Fix a memory leak in os.chdir() on Windows if the
     current directory is set to a UNC path.

   - bpo-31966(3): Fixed WindowsConsoleIO.write() for writing empty
     data.

   - bpo-32409(4): Ensures activate.bat can handle Unicode contents.

   - bpo-32457(5): Improves handling of denormalized executable path
     when launching Python.

   - bpo-32370(6): Use the correct encoding for ipconfig output in the
     uuid module.  Patch by Segev Finer.

   - bpo-29248(7): Fix *note os.readlink(): b1c. on Windows, which was
     mistakenly treating the ‘PrintNameOffset’ field of the reparse data
     buffer as a number of characters instead of bytes.  Patch by Craig
     Holmquist and SSE4.

   - bpo-32588(8): Create standalone _distutils_findvs module.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33016

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32903

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31966

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32409

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32457

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32370

   (7) https://bugs.python.org/issue?@action=redirect&bpo=29248

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32588


File: python.info,  Node: macOS<49>,  Next: IDLE<47>,  Prev: Windows<64>,  Up: Python 3 6 5 release candidate 1

1.24.76.8 macOS
...............

   - bpo-32726(1): Provide an additional, more modern macOS installer
     variant that supports macOS 10.9+ systems in 64-bit mode only.
     Upgrade the supplied third-party libraries to OpenSSL 1.0.2n, XZ
     5.2.3, and SQLite 3.22.0.  The 10.9+ installer now links with and
     supplies its own copy of Tcl/Tk 8.6.8.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32726


File: python.info,  Node: IDLE<47>,  Next: Tools/Demos<45>,  Prev: macOS<49>,  Up: Python 3 6 5 release candidate 1

1.24.76.9 IDLE
..............

   - bpo-32984(1): Set ‘__file__’ while running a startup file.  Like
     Python, IDLE optionally runs one startup file in the Shell window
     before presenting the first interactive input prompt.  For IDLE,
     ‘-s’ runs a file named in environmental variable ‘IDLESTARTUP’ or
     *note PYTHONSTARTUP: 1b8.; ‘-r file’ runs ‘file’.  Python sets
     ‘__file__’ to the startup file name before running the file and
     unsets it before the first prompt.  IDLE now does the same when run
     normally, without the ‘-n’ option.

   - bpo-32940(2): Simplify and rename StringTranslatePseudoMapping in
     pyparse.

   - bpo-32916(3): Change ‘str’ to ‘code’ in pyparse.

   - bpo-32905(4): Remove unused code in pyparse module.

   - bpo-32874(5): Add tests for pyparse.

   - bpo-32837(6): Using the system and place-dependent default encoding
     for open() is a bad idea for IDLE’s system and location-independent
     files.

   - bpo-32826(7): Add «encoding=utf-8» to open() in IDLE’s
     test_help_about.  GUI test test_file_buttons() only looks at
     initial ascii-only lines, but failed on systems where open()
     defaults to “ascii” because readline() internally reads and decodes
     far enough ahead to encounter a non-ascii character in CREDITS.txt.

   - bpo-32765(8): Update configdialog General tab docstring to add new
     widgets to the widget list.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32984

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32940

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32916

   (4) https://bugs.python.org/issue?@action=redirect&bpo=32905

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32874

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32837

   (7) https://bugs.python.org/issue?@action=redirect&bpo=32826

   (8) https://bugs.python.org/issue?@action=redirect&bpo=32765


File: python.info,  Node: Tools/Demos<45>,  Next: C API<65>,  Prev: IDLE<47>,  Up: Python 3 6 5 release candidate 1

1.24.76.10 Tools/Demos
......................

   - bpo-24960(1): 2to3 and lib2to3 can now read pickled grammar files
     using pkgutil.get_data() rather than probing the filesystem.  This
     lets 2to3 and lib2to3 work when run from a zipfile.

   - bpo-32222(2): Fix pygettext not extracting docstrings for functions
     with type annotated arguments.  Patch by Toby Harradine.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24960

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32222


File: python.info,  Node: C API<65>,  Prev: Tools/Demos<45>,  Up: Python 3 6 5 release candidate 1

1.24.76.11 C API
................

   - bpo-29084(1): Undocumented C API for OrderedDict has been excluded
     from the limited C API. It was added by mistake and actually never
     worked in the limited C API.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29084


File: python.info,  Node: Python 3 6 4 final,  Next: Python 3 6 4 release candidate 1,  Prev: Python 3 6 5 release candidate 1,  Up: Changelog

1.24.77 Python 3.6.4 final
--------------------------

'Release date: 2017-12-18'

There were no new code changes in version 3.6.4 since v3.6.4rc1.


File: python.info,  Node: Python 3 6 4 release candidate 1,  Next: Python 3 6 3 final,  Prev: Python 3 6 4 final,  Up: Changelog

1.24.78 Python 3.6.4 release candidate 1
----------------------------------------

'Release date: 2017-12-05'

* Menu:

* Core and Builtins: Core and Builtins<171>.
* Library: Library<175>.
* Documentation: Documentation<68>.
* Tests: Tests<66>.
* Build: Build<74>.
* Windows: Windows<65>.
* macOS: macOS<50>.
* IDLE: IDLE<48>.
* Tools/Demos: Tools/Demos<46>.
* C API: C API<66>.


File: python.info,  Node: Core and Builtins<171>,  Next: Library<175>,  Up: Python 3 6 4 release candidate 1

1.24.78.1 Core and Builtins
...........................

   - bpo-32176(1): co_flags.CO_NOFREE is now always set correctly by the
     code object constructor based on freevars and cellvars, rather than
     needing to be set correctly by the caller.  This ensures it will be
     cleared automatically when additional cell references are injected
     into a modified code object and function.

   - bpo-31949(2): Fixed several issues in printing tracebacks
     (PyTraceBack_Print()).  Setting sys.tracebacklimit to 0 or less now
     suppresses printing tracebacks.  Setting sys.tracebacklimit to None
     now causes using the default limit.  Setting sys.tracebacklimit to
     an integer larger than LONG_MAX now means using the limit LONG_MAX
     rather than the default limit.  Fixed integer overflows in the case
     of more than ‘2**31’ traceback items on Windows.  Fixed output
     errors handling.

   - bpo-30696(3): Fix the interactive interpreter looping endlessly
     when no memory.

   - bpo-20047(4): Bytearray methods partition() and rpartition() now
     accept only bytes-like objects as separator, as documented.  In
     particular they now raise TypeError rather of returning a bogus
     result when an integer is passed as a separator.

   - bpo-31852(5): Fix a segmentation fault caused by a combination of
     the async soft keyword and continuation lines.

   - bpo-21720(6): BytesWarning no longer emitted when the 'fromlist'
     argument of ‘__import__()’ or the ‘__all__’ attribute of the module
     contain bytes instances.

   - bpo-31825(7): Fixed OverflowError in the “unicode-escape” codec and
     in codecs.escape_decode() when decode an escaped non-ascii byte.

   - bpo-28603(8): Print the full context/cause chain of exceptions on
     interpreter exit, even if an exception in the chain is unhashable
     or compares equal to later ones.  Patch by Zane Bitter.

   - bpo-31786(9): Fix timeout rounding in the select module to round
     correctly negative timeouts between -1.0 and 0.0.  The functions
     now block waiting for events as expected.  Previously, the call was
     incorrectly non-blocking.  Patch by Pablo Galindo.

   - bpo-31642(10): Restored blocking «from package import module» by
     setting sys.modules[«package.module»] to None.

   - bpo-31626(11): Fixed a bug in debug memory allocator.  There was a
     write to freed memory after shrinking a memory block.

   - bpo-31619(12): Fixed a ValueError when convert a string with large
     number of underscores to integer with binary base.

   - bpo-31592(13): Fixed an assertion failure in Python parser in case
     of a bad ‘unicodedata.normalize()’.  Patch by Oren Milman.

   - bpo-31588(14): Raise a ‘TypeError’ with a helpful error message
     when class creation fails due to a metaclass with a bad
     ‘__prepare__()’ method.  Patch by Oren Milman.

   - bpo-31566(15): Fix an assertion failure in ‘_warnings.warn()’ in
     case of a bad ‘__name__’ global.  Patch by Oren Milman.

   - bpo-31505(16): Fix an assertion failure in ‘json’, in case
     ‘_json.make_encoder()’ received a bad ‘encoder()’ argument.  Patch
     by Oren Milman.

   - bpo-31492(17): Fix assertion failures in case of failing to import
     from a module with a bad ‘__name__’ attribute, and in case of
     failing to access an attribute of such a module.  Patch by Oren
     Milman.

   - bpo-31490(18): Fix an assertion failure in ‘ctypes’ class
     definition, in case the class has an attribute whose name is
     specified in ‘_anonymous_’ but not in ‘_fields_’.  Patch by Oren
     Milman.

   - bpo-31478(19): Fix an assertion failure in ‘_random.Random.seed()’
     in case the argument has a bad ‘__abs__()’ method.  Patch by Oren
     Milman.

   - bpo-31315(20): Fix an assertion failure in imp.create_dynamic(),
     when spec.name is not a string.  Patch by Oren Milman.

   - bpo-31311(21): Fix a crash in the ‘__setstate__()’ method of
     ‘ctypes._CData’, in case of a bad ‘__dict__’.  Patch by Oren
     Milman.

   - bpo-31293(22): Fix crashes in true division and multiplication of a
     timedelta object by a float with a bad as_integer_ratio() method.
     Patch by Oren Milman.

   - bpo-31285(23): Fix an assertion failure in
     ‘warnings.warn_explicit’, when the return value of the received
     loader’s ‘get_source()’ has a bad ‘splitlines()’ method.  Patch by
     Oren Milman.

   - bpo-30817(24): ‘PyErr_PrintEx()’ clears now the ignored exception
     that may be raised by ‘_PySys_SetObjectId()’, for example when no
     memory.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32176

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31949

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30696

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20047

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31852

   (6) https://bugs.python.org/issue?@action=redirect&bpo=21720

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31825

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28603

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31786

   (10) https://bugs.python.org/issue?@action=redirect&bpo=31642

   (11) https://bugs.python.org/issue?@action=redirect&bpo=31626

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31619

   (13) https://bugs.python.org/issue?@action=redirect&bpo=31592

   (14) https://bugs.python.org/issue?@action=redirect&bpo=31588

   (15) https://bugs.python.org/issue?@action=redirect&bpo=31566

   (16) https://bugs.python.org/issue?@action=redirect&bpo=31505

   (17) https://bugs.python.org/issue?@action=redirect&bpo=31492

   (18) https://bugs.python.org/issue?@action=redirect&bpo=31490

   (19) https://bugs.python.org/issue?@action=redirect&bpo=31478

   (20) https://bugs.python.org/issue?@action=redirect&bpo=31315

   (21) https://bugs.python.org/issue?@action=redirect&bpo=31311

   (22) https://bugs.python.org/issue?@action=redirect&bpo=31293

   (23) https://bugs.python.org/issue?@action=redirect&bpo=31285

   (24) https://bugs.python.org/issue?@action=redirect&bpo=30817


File: python.info,  Node: Library<175>,  Next: Documentation<68>,  Prev: Core and Builtins<171>,  Up: Python 3 6 4 release candidate 1

1.24.78.2 Library
.................

   - bpo-28556(1): Two minor fixes for ‘typing’ module: allow shallow
     copying instances of generic classes, improve interaction of
     ‘__init_subclass__’ with generics.  Original PRs by Ivan
     Levkivskyi.

   - bpo-27240(2): The header folding algorithm for the new email
     policies has been rewritten, which also fixes bpo-30788(3),
     bpo-31831(4), and bpo-32182(5).  In particular, RFC2231 folding is
     now done correctly.

   - bpo-32186(6): io.FileIO.readall() and io.FileIO.read() now release
     the GIL when getting the file size.  Fixed hang of all threads with
     inaccessible NFS server.  Patch by Nir Soffer.

   - bpo-12239(7): Make ‘msilib.SummaryInformation.GetProperty()’ return
     ‘None’ when the value of property is ‘VT_EMPTY’.  Initial patch by
     Mark Mc Mahon.

   - bpo-31325(8): Fix wrong usage of *note collections.namedtuple():
     4e1. in the *note RobotFileParser.parse(): 1e6b. method.  Initial
     patch by Robin Wellner.

   - bpo-12382(9): ‘msilib.OpenDatabase()’ now raises a better exception
     message when it couldn’t open or create an MSI file.  Initial patch
     by William Tisäter.

   - bpo-32110(10): ‘codecs.StreamReader.read(n)’ now returns not more
     than 'n' characters/bytes for non-negative 'n'.  This makes it
     compatible with ‘read()’ methods of other file-like objects.

   - bpo-32072(11): Fixed issues with binary plists: Fixed saving
     bytearrays.  Identical objects will be saved only once.  Equal
     references will be load as identical objects.  Added support for
     saving and loading recursive data structures.

   - bpo-32034(12): Make asyncio.IncompleteReadError and
     LimitOverrunError pickleable.

   - bpo-32015(13): Fixed the looping of asyncio in the case of
     reconnection the socket during waiting async read/write from/to the
     socket.

   - bpo-32011(14): Restored support of loading marshal files with the
     TYPE_INT64 code.  These files can be produced in Python 2.7.

   - bpo-31970(15): Reduce performance overhead of asyncio debug mode.

   - bpo-9678(16): Fixed determining the MAC address in the uuid module:
     Using ifconfig on NetBSD and OpenBSD. Using arp on Linux, FreeBSD,
     NetBSD and OpenBSD. Based on patch by Takayuki Shimizukawa.

   - bpo-30057(17): Fix potential missed signal in signal.signal().

   - bpo-31933(18): Fix Blake2 params leaf_size and node_offset on big
     endian platforms.  Patch by Jack O’Connor.

   - bpo-31927(19): Fixed compilation of the socket module on NetBSD 8.
     Fixed assertion failure or reading arbitrary data when parse a
     AF_BLUETOOTH address on NetBSD and DragonFly BSD.

   - bpo-27666(20): Fixed stack corruption in curses.box() and
     curses.ungetmouse() when the size of types chtype or mmask_t is
     less than the size of C long.  curses.box() now accepts characters
     as arguments.  Based on patch by Steve Fink.

   - bpo-31897(21): plistlib now catches more errors when read binary
     plists and raises InvalidFileException instead of unexpected
     exceptions.

   - bpo-25720(22): Fix the method for checking pad state of curses
     WINDOW. Patch by Masayuki Yamamoto.

   - bpo-31893(23): Fixed the layout of the kqueue_event structure on
     OpenBSD and NetBSD. Fixed the comparison of the kqueue_event
     objects.

   - bpo-31891(24): Fixed building the curses module on NetBSD.

   - bpo-28416(25): Instances of pickle.Pickler subclass with the
     persistent_id() method and pickle.Unpickler subclass with the
     persistent_load() method no longer create reference cycles.

   - bpo-28326(26): Fix multiprocessing.Process when stdout and/or
     stderr is closed or None.

   - bpo-31457(27): If nested log adapters are used, the inner
     ‘process()’ methods are no longer omitted.

   - bpo-31457(28): The ‘manager’ property on LoggerAdapter objects is
     now properly settable.

   - bpo-31806(29): Fix timeout rounding in time.sleep(),
     threading.Lock.acquire() and socket.socket.settimeout() to round
     correctly negative timeouts between -1.0 and 0.0.  The functions
     now block waiting for events as expected.  Previously, the call was
     incorrectly non-blocking.  Patch by Pablo Galindo.

   - bpo-28603(30): traceback: Fix a TypeError that occurred during
     printing of exception tracebacks when either the current exception
     or an exception in its context/cause chain is unhashable.  Patch by
     Zane Bitter.

   - bpo-30058(31): Fixed buffer overflow in select.kqueue.control().

   - bpo-31770(32): Prevent a crash when calling the ‘__init__()’ method
     of a ‘sqlite3.Cursor’ object more than once.  Patch by Oren Milman.

   - bpo-31672(33): ‘idpattern’ in ‘string.Template’ matched some
     non-ASCII characters.  Now it uses ‘-i’ regular expression local
     flag to avoid non-ASCII characters.

   - bpo-31764(34): Prevent a crash in ‘sqlite3.Cursor.close()’ in case
     the ‘Cursor’ object is uninitialized.  Patch by Oren Milman.

   - bpo-31752(35): Fix possible crash in timedelta constructor called
     with custom integers.

   - bpo-31701(36): On Windows, faulthandler.enable() now ignores MSC
     and COM exceptions.

   - bpo-31728(37): Prevent crashes in ‘_elementtree’ due to unsafe
     cleanup of ‘Element.text’ and ‘Element.tail’.  Patch by Oren
     Milman.

   - bpo-31620(38): an empty asyncio.Queue now doesn’t leak memory when
     queue.get pollers timeout

   - bpo-31632(39): Fix method set_protocol() of class
     _SSLProtocolTransport in asyncio module.  This method was
     previously modifying a wrong reference to the protocol.

   - bpo-31675(40): Fixed memory leaks in Tkinter’s methods splitlist()
     and split() when pass a string larger than 2 GiB.

   - bpo-31673(41): Fixed typo in the name of Tkinter’s method
     adderrorinfo().

   - bpo-30806(42): Fix the string representation of a netrc object.

   - bpo-15037(43): Added a workaround for getkey() in curses for
     ncurses 5.7 and earlier.

   - bpo-25351(44): Avoid venv activate failures with undefined
     variables

   - bpo-25532(45): inspect.unwrap() will now only try to unwrap an
     object sys.getrecursionlimit() times, to protect against objects
     which create a new object on every attribute access.

   - bpo-30347(46): Stop crashes when concurrently iterate over
     itertools.groupby() iterators.

   - bpo-31516(47): ‘threading.current_thread()’ should not return a
     dummy thread at shutdown.

   - bpo-31351(48): python -m ensurepip now exits with non-zero exit
     code if pip bootstrapping has failed.

   - bpo-31482(49): ‘random.seed()’ now works with bytes in version=1

   - bpo-31334(50): Fix ‘poll.poll([timeout])’ in the ‘select’ module
     for arbitrary negative timeouts on all OSes where it can only be a
     non-negative integer or -1.  Patch by Riccardo Coccioli.

   - bpo-31310(51): multiprocessing’s semaphore tracker should be
     launched again if crashed.

   - bpo-31308(52): Make multiprocessing’s forkserver process immune to
     Ctrl-C and other user interruptions.  If it crashes, restart it
     when necessary.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27240

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30788

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31831

   (5) https://bugs.python.org/issue?@action=redirect&bpo=32182

   (6) https://bugs.python.org/issue?@action=redirect&bpo=32186

   (7) https://bugs.python.org/issue?@action=redirect&bpo=12239

   (8) https://bugs.python.org/issue?@action=redirect&bpo=31325

   (9) https://bugs.python.org/issue?@action=redirect&bpo=12382

   (10) https://bugs.python.org/issue?@action=redirect&bpo=32110

   (11) https://bugs.python.org/issue?@action=redirect&bpo=32072

   (12) https://bugs.python.org/issue?@action=redirect&bpo=32034

   (13) https://bugs.python.org/issue?@action=redirect&bpo=32015

   (14) https://bugs.python.org/issue?@action=redirect&bpo=32011

   (15) https://bugs.python.org/issue?@action=redirect&bpo=31970

   (16) https://bugs.python.org/issue?@action=redirect&bpo=9678

   (17) https://bugs.python.org/issue?@action=redirect&bpo=30057

   (18) https://bugs.python.org/issue?@action=redirect&bpo=31933

   (19) https://bugs.python.org/issue?@action=redirect&bpo=31927

   (20) https://bugs.python.org/issue?@action=redirect&bpo=27666

   (21) https://bugs.python.org/issue?@action=redirect&bpo=31897

   (22) https://bugs.python.org/issue?@action=redirect&bpo=25720

   (23) https://bugs.python.org/issue?@action=redirect&bpo=31893

   (24) https://bugs.python.org/issue?@action=redirect&bpo=31891

   (25) https://bugs.python.org/issue?@action=redirect&bpo=28416

   (26) https://bugs.python.org/issue?@action=redirect&bpo=28326

   (27) https://bugs.python.org/issue?@action=redirect&bpo=31457

   (28) https://bugs.python.org/issue?@action=redirect&bpo=31457

   (29) https://bugs.python.org/issue?@action=redirect&bpo=31806

   (30) https://bugs.python.org/issue?@action=redirect&bpo=28603

   (31) https://bugs.python.org/issue?@action=redirect&bpo=30058

   (32) https://bugs.python.org/issue?@action=redirect&bpo=31770

   (33) https://bugs.python.org/issue?@action=redirect&bpo=31672

   (34) https://bugs.python.org/issue?@action=redirect&bpo=31764

   (35) https://bugs.python.org/issue?@action=redirect&bpo=31752

   (36) https://bugs.python.org/issue?@action=redirect&bpo=31701

   (37) https://bugs.python.org/issue?@action=redirect&bpo=31728

   (38) https://bugs.python.org/issue?@action=redirect&bpo=31620

   (39) https://bugs.python.org/issue?@action=redirect&bpo=31632

   (40) https://bugs.python.org/issue?@action=redirect&bpo=31675

   (41) https://bugs.python.org/issue?@action=redirect&bpo=31673

   (42) https://bugs.python.org/issue?@action=redirect&bpo=30806

   (43) https://bugs.python.org/issue?@action=redirect&bpo=15037

   (44) https://bugs.python.org/issue?@action=redirect&bpo=25351

   (45) https://bugs.python.org/issue?@action=redirect&bpo=25532

   (46) https://bugs.python.org/issue?@action=redirect&bpo=30347

   (47) https://bugs.python.org/issue?@action=redirect&bpo=31516

   (48) https://bugs.python.org/issue?@action=redirect&bpo=31351

   (49) https://bugs.python.org/issue?@action=redirect&bpo=31482

   (50) https://bugs.python.org/issue?@action=redirect&bpo=31334

   (51) https://bugs.python.org/issue?@action=redirect&bpo=31310

   (52) https://bugs.python.org/issue?@action=redirect&bpo=31308


File: python.info,  Node: Documentation<68>,  Next: Tests<66>,  Prev: Library<175>,  Up: Python 3 6 4 release candidate 1

1.24.78.3 Documentation
.......................

   - bpo-32105(1): Added asyncio.BaseEventLoop.connect_accepted_socket
     versionadded marker.

   - bpo-31537(2): Fix incorrect usage of ‘get_history_length’ in
     readline documentation example code.  Patch by Brad Smith.

   - bpo-30085(3): The operator functions without double underscores are
     preferred for clarity.  The one with underscores are only kept for
     back-compatibility.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32105

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31537

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30085


File: python.info,  Node: Tests<66>,  Next: Build<74>,  Prev: Documentation<68>,  Up: Python 3 6 4 release candidate 1

1.24.78.4 Tests
...............

   - bpo-31380(1): Skip test_httpservers test_undecodable_file on macOS:
     fails on APFS.

   - bpo-31705(2): Skip test_socket.test_sha256() on Linux kernel older
     than 4.5.  The test fails with ENOKEY on kernel 3.10 (on ppc64le).
     A fix was merged into the kernel 4.5.

   - bpo-31174(3): Fix test_tools.test_unparse: DirectoryTestCase now
     stores the names sample to always test the same files.  It prevents
     false alarms when hunting reference leaks.

   - bpo-30695(4): Add the ‘set_nomemory(start, stop)’ and
     ‘remove_mem_hooks()’ functions to the ‘_testcapi’ module.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31380

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31705

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31174

   (4) https://bugs.python.org/issue?@action=redirect&bpo=30695


File: python.info,  Node: Build<74>,  Next: Windows<65>,  Prev: Tests<66>,  Up: Python 3 6 4 release candidate 1

1.24.78.5 Build
...............

   - bpo-32059(1): ‘detect_modules()’ in ‘setup.py’ now also searches
     the sysroot paths when cross-compiling.

   - bpo-31957(2): Fixes Windows SDK version detection when building for
     Windows.

   - bpo-31609(3): Fixes quotes in PCbuild/clean.bat

   - bpo-31934(4): Abort the build when building out of a not clean
     source tree.

   - bpo-31926(5): Fixed Argument Clinic sometimes causing compilation
     errors when there was more than one function and/or method in a .c
     file with the same name.

   - bpo-28791(6): Update Windows builds to use SQLite 3.21.0.

   - bpo-28791(7): Update OS X installer to use SQLite 3.21.0.

   - bpo-22140(8): Prevent double substitution of prefix in
     python-config.sh.

   - bpo-31536(9): Avoid wholesale rebuild after ‘make regen-all’ if
     nothing changed.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32059

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31957

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31609

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31934

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31926

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28791

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28791

   (8) https://bugs.python.org/issue?@action=redirect&bpo=22140

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31536


File: python.info,  Node: Windows<65>,  Next: macOS<50>,  Prev: Build<74>,  Up: Python 3 6 4 release candidate 1

1.24.78.6 Windows
.................

   - bpo-1102(1): Return ‘None’ when ‘View.Fetch()’ returns
     ‘ERROR_NO_MORE_ITEMS’ instead of raising ‘MSIError’.  Initial patch
     by Anthony Tuininga.

   - bpo-31944(2): Fixes Modify button in Apps and Features dialog.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=1102

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31944


File: python.info,  Node: macOS<50>,  Next: IDLE<48>,  Prev: Windows<65>,  Up: Python 3 6 4 release candidate 1

1.24.78.7 macOS
...............

   - bpo-31392(1): Update macOS installer to use OpenSSL 1.0.2m

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31392


File: python.info,  Node: IDLE<48>,  Next: Tools/Demos<46>,  Prev: macOS<50>,  Up: Python 3 6 4 release candidate 1

1.24.78.8 IDLE
..............

   - bpo-32207(1): Improve tk event exception tracebacks in IDLE. When
     tk event handling is driven by IDLE’s run loop, a confusing and
     distracting queue.EMPTY traceback context is no longer added to tk
     event exception tracebacks.  The traceback is now the same as when
     event handling is driven by user code.  Patch based on a suggestion
     by Serhiy Storchaka.

   - bpo-32164(2): Delete unused file idlelib/tabbedpages.py.  Use of
     TabbedPageSet in configdialog was replaced by ttk.Notebook.

   - bpo-32100(3): IDLE: Fix old and new bugs in pathbrowser; improve
     tests.  Patch mostly by Cheryl Sabella.

   - bpo-31858(4): IDLE – Restrict shell prompt manipulation to the
     shell.  Editor and output windows only see an empty last prompt
     line.  This simplifies the code and fixes a minor bug when newline
     is inserted.  Sys.ps1, if present, is read on Shell start-up, but
     is not set or changed.

   - bpo-31860(5): The font sample in the IDLE configuration dialog is
     now editable.  Changes persist while IDLE remains open

   - bpo-31836(6): Test_code_module now passes if run after test_idle,
     which sets ps1.  The code module uses sys.ps1 if present or sets it
     to “>>> “ if not.  Test_code_module now properly tests both
     behaviors.  Ditto for ps2.

   - bpo-28603(7): Fix a TypeError that caused a shell restart when
     printing a traceback that includes an exception that is unhashable.
     Patch by Zane Bitter.

   - bpo-13802(8): Use non-Latin characters in the IDLE’s Font settings
     sample.  Even if one selects a font that defines a limited subset
     of the unicode Basic Multilingual Plane, tcl/tk will use other
     fonts that define a character.  The expanded example give users of
     non-Latin characters a better idea of what they might see in IDLE’s
     shell and editors.  To make room for the expanded sample, frames on
     the Font tab are re-arranged.  The Font/Tabs help explains a bit
     about the additions.

   - bpo-31460(9): Simplify the API of IDLE’s Module Browser.  Passing a
     widget instead of an flist with a root widget opens the option of
     creating a browser frame that is only part of a window.  Passing a
     full file name instead of pieces assumed to come from a .py file
     opens the possibility of browsing python files that do not end in
     .py.

   - bpo-31649(10): IDLE - Make _htest, _utest parameters keyword only.

   - bpo-31559(11): Remove test order dependence in
     idle_test.test_browser.

   - bpo-31459(12): Rename IDLE’s module browser from Class Browser to
     Module Browser.  The original module-level class and method browser
     became a module browser, with the addition of module-level
     functions, years ago.  Nested classes and functions were added
     yesterday.  For back-compatibility, the virtual event
     <<open-class-browser>>, which appears on the Keys tab of the
     Settings dialog, is not changed.  Patch by Cheryl Sabella.

   - bpo-31500(13): Default fonts now are scaled on HiDPI displays.

   - bpo-1612262(14): IDLE module browser now shows nested classes and
     functions.  Original patches for code and tests by Guilherme Polo
     and Cheryl Sabella, respectively.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32207

   (2) https://bugs.python.org/issue?@action=redirect&bpo=32164

   (3) https://bugs.python.org/issue?@action=redirect&bpo=32100

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31858

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31860

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31836

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28603

   (8) https://bugs.python.org/issue?@action=redirect&bpo=13802

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31460

   (10) https://bugs.python.org/issue?@action=redirect&bpo=31649

   (11) https://bugs.python.org/issue?@action=redirect&bpo=31559

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31459

   (13) https://bugs.python.org/issue?@action=redirect&bpo=31500

   (14) https://bugs.python.org/issue?@action=redirect&bpo=1612262


File: python.info,  Node: Tools/Demos<46>,  Next: C API<66>,  Prev: IDLE<48>,  Up: Python 3 6 4 release candidate 1

1.24.78.9 Tools/Demos
.....................

   - bpo-30722(1): Make redemo work with Python 3.6 and newer versions.
     Also, remove the ‘LOCALE’ option since it doesn’t work with string
     patterns in Python 3.  Patch by Christoph Sarnowski.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30722


File: python.info,  Node: C API<66>,  Prev: Tools/Demos<46>,  Up: Python 3 6 4 release candidate 1

1.24.78.10 C API
................

   - bpo-20891(1): Fix PyGILState_Ensure().  When PyGILState_Ensure() is
     called in a non-Python thread before PyEval_InitThreads(), only
     call PyEval_InitThreads() after calling PyThreadState_New() to fix
     a crash.

   - bpo-31532(2): Fix memory corruption due to allocator mix in
     getpath.c between Py_GetPath() and Py_SetPath()

   - bpo-30697(3): The ‘PyExc_RecursionErrorInst’ singleton is removed
     and ‘PyErr_NormalizeException()’ does not use it anymore.  This
     singleton is persistent and its members being never cleared may
     cause a segfault during finalization of the interpreter.  See also
     bpo-22898(4).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20891

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31532

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30697

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22898


File: python.info,  Node: Python 3 6 3 final,  Next: Python 3 6 3 release candidate 1,  Prev: Python 3 6 4 release candidate 1,  Up: Changelog

1.24.79 Python 3.6.3 final
--------------------------

'Release date: 2017-10-03'

* Menu:

* Library: Library<176>.
* Build: Build<75>.


File: python.info,  Node: Library<176>,  Next: Build<75>,  Up: Python 3 6 3 final

1.24.79.1 Library
.................

   - bpo-31641(1): Re-allow arbitrary iterables in
     ‘concurrent.futures.as_completed()’.  Fixes regression in 3.6.3rc1.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31641


File: python.info,  Node: Build<75>,  Prev: Library<176>,  Up: Python 3 6 3 final

1.24.79.2 Build
...............

   - bpo-31662(1): Fix typos in Windows ‘uploadrelease.bat’ script.  Fix
     Windows Doc build issues in ‘Doc/make.bat’.

   - bpo-31423(2): Fix building the PDF documentation with newer
     versions of Sphinx.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31662

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31423


File: python.info,  Node: Python 3 6 3 release candidate 1,  Next: Python 3 6 2 final,  Prev: Python 3 6 3 final,  Up: Changelog

1.24.80 Python 3.6.3 release candidate 1
----------------------------------------

'Release date: 2017-09-18'

* Menu:

* Security: Security<51>.
* Core and Builtins: Core and Builtins<172>.
* Library: Library<177>.
* Documentation: Documentation<69>.
* Tests: Tests<67>.
* Build: Build<76>.
* Windows: Windows<66>.
* IDLE: IDLE<49>.
* Tools/Demos: Tools/Demos<47>.


File: python.info,  Node: Security<51>,  Next: Core and Builtins<172>,  Up: Python 3 6 3 release candidate 1

1.24.80.1 Security
..................

   - bpo-29781(1): SSLObject.version() now correctly returns None when
     handshake over BIO has not been performed yet.

   - bpo-30947(2): Upgrade libexpat embedded copy from version 2.2.1 to
     2.2.3 to get security fixes.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29781

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30947


File: python.info,  Node: Core and Builtins<172>,  Next: Library<177>,  Prev: Security<51>,  Up: Python 3 6 3 release candidate 1

1.24.80.2 Core and Builtins
...........................

   - bpo-31471(1): Fix an assertion failure in ‘subprocess.Popen()’ on
     Windows, in case the env argument has a bad ‘keys()’ method.  Patch
     by Oren Milman.

   - bpo-31418(2): Fix an assertion failure in ‘PyErr_WriteUnraisable()’
     in case of an exception with a bad ‘__module__’ attribute.  Patch
     by Oren Milman.

   - bpo-31416(3): Fix assertion failures in case of a bad
     warnings.filters or warnings.defaultaction.  Patch by Oren Milman.

   - bpo-31411(4): Raise a TypeError instead of SystemError in case
     warnings.onceregistry is not a dictionary.  Patch by Oren Milman.

   - bpo-31373(5): Fix several possible instances of undefined behavior
     due to floating-point demotions.

   - bpo-30465(6): Location information (‘lineno’ and ‘col_offset’) in
     f-strings is now (mostly) correct.  This fixes tools like flake8
     from showing warnings on the wrong line (typically the first line
     of the file).

   - bpo-31343(7): Include sys/sysmacros.h for major(), minor(), and
     makedev().  GNU C library plans to remove the functions from
     sys/types.h.

   - bpo-31291(8): Fix an assertion failure in
     ‘zipimport.zipimporter.get_data’ on Windows, when the return value
     of ‘pathname.replace('/','\\')’ isn’t a string.  Patch by Oren
     Milman.

   - bpo-31271(9): Fix an assertion failure in the ‘write()’ method of
     ‘io.TextIOWrapper’, when the encoder doesn’t return a bytes object.
     Patch by Oren Milman.

   - bpo-31243(10): Fix a crash in some methods of ‘io.TextIOWrapper’,
     when the decoder’s state is invalid.  Patch by Oren Milman.

   - bpo-30721(11): ‘print’ now shows correct usage hint for using
     Python 2 redirection syntax.  Patch by Sanyam Khurana.

   - bpo-31070(12): Fix a race condition in importlib
     _get_module_lock().

   - bpo-31095(13): Fix potential crash during GC caused by ‘tp_dealloc’
     which doesn’t call ‘PyObject_GC_UnTrack()’.

   - bpo-31071(14): Avoid masking original TypeError in call with *
     unpacking when other arguments are passed.

   - bpo-30978(15): str.format_map() now passes key lookup exceptions
     through.  Previously any exception was replaced with a KeyError
     exception.

   - bpo-30808(16): Use _Py_atomic API for concurrency-sensitive signal
     state.

   - bpo-30876(17): Relative import from unloaded package now reimports
     the package instead of failing with SystemError.  Relative import
     from non-package now fails with ImportError rather than
     SystemError.

   - bpo-30703(18): Improve signal delivery.  Avoid using
     Py_AddPendingCall from signal handler, to avoid calling
     signal-unsafe functions.  The tests I’m adding here fail without
     the rest of the patch, on Linux and OS X. This means our signal
     delivery logic had defects (some signals could be lost).

   - bpo-30765(19): Avoid blocking in pthread_mutex_lock() when
     PyThread_acquire_lock() is asked not to block.

   - bpo-31161(20): Make sure the “Missing parentheses” syntax error
     message is only applied to SyntaxError, not to subclasses.  Patch
     by Martijn Pieters.

   - bpo-30814(21): Fixed a race condition when import a submodule from
     a package.

   - bpo-30597(22): ‘print’ now shows expected input in custom error
     message when used as a Python 2 statement.  Patch by Sanyam
     Khurana.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31471

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31418

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31416

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31411

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31373

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30465

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31343

   (8) https://bugs.python.org/issue?@action=redirect&bpo=31291

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31271

   (10) https://bugs.python.org/issue?@action=redirect&bpo=31243

   (11) https://bugs.python.org/issue?@action=redirect&bpo=30721

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31070

   (13) https://bugs.python.org/issue?@action=redirect&bpo=31095

   (14) https://bugs.python.org/issue?@action=redirect&bpo=31071

   (15) https://bugs.python.org/issue?@action=redirect&bpo=30978

   (16) https://bugs.python.org/issue?@action=redirect&bpo=30808

   (17) https://bugs.python.org/issue?@action=redirect&bpo=30876

   (18) https://bugs.python.org/issue?@action=redirect&bpo=30703

   (19) https://bugs.python.org/issue?@action=redirect&bpo=30765

   (20) https://bugs.python.org/issue?@action=redirect&bpo=31161

   (21) https://bugs.python.org/issue?@action=redirect&bpo=30814

   (22) https://bugs.python.org/issue?@action=redirect&bpo=30597


File: python.info,  Node: Library<177>,  Next: Documentation<69>,  Prev: Core and Builtins<172>,  Up: Python 3 6 3 release candidate 1

1.24.80.3 Library
.................

   - bpo-31499(1): xml.etree: Fix a crash when a parser is part of a
     reference cycle.

   - bpo-28556(2): typing.get_type_hints now finds the right globalns
     for classes and modules by default (when no ‘globalns’ was
     specified by the caller).

   - bpo-28556(3): Speed improvements to the ‘typing’ module.  Original
     PRs by Ivan Levkivskyi and Mitar.

   - bpo-31544(4): The C accelerator module of ElementTree ignored
     exceptions raised when looking up TreeBuilder target methods in
     XMLParser().

   - bpo-31234(5): socket.create_connection() now fixes manually a
     reference cycle: clear the variable storing the last exception on
     success.

   - bpo-31457(6): LoggerAdapter objects can now be nested.

   - bpo-31400(7): Improves SSL error handling to avoid losing error
     numbers.

   - bpo-28958(8): ssl.SSLContext() now uses OpenSSL error information
     when a context cannot be instantiated.

   - bpo-27340(9): SSLSocket.sendall() now uses memoryview to create
     slices of data.  This fixes support for all bytes-like object.  It
     is also more efficient and avoids costly copies.

   - bpo-31178(10): Fix string concatenation bug in rare error path in
     the subprocess module

   - bpo-31350(11): Micro-optimize ‘asyncio._get_running_loop()’ to
     become up to 10% faster.

   - bpo-31170(12): expat: Update libexpat from 2.2.3 to 2.2.4.  Fix
     copying of partial characters for UTF-8 input (libexpat bug 115):
     ‘https://github.com/libexpat/libexpat/issues/115’

   - bpo-29136(13): Add TLS 1.3 cipher suites and OP_NO_TLSv1_3.

   - bpo-29212(14): Fix concurrent.futures.thread.ThreadPoolExecutor
     threads to have a non repr() based thread name by default when no
     thread_name_prefix is supplied.  They will now identify themselves
     as «ThreadPoolExecutor-y_n».

   - bpo-9146(15): Fix a segmentation fault in _hashopenssl when
     standard hash functions such as md5 are not available in the linked
     OpenSSL library.  As in some special FIPS-140 build environments.

   - bpo-27144(16): The ‘map()’ and ‘as_completed()’ iterators in
     ‘concurrent.futures’ now avoid keeping a reference to yielded
     objects.

   - bpo-10746(17): Fix ctypes producing wrong PEP 3118(18) type codes
     for integer types.

   - bpo-22536(19): The subprocess module now sets the filename when
     FileNotFoundError is raised on POSIX systems due to the executable
     or cwd not being found.

   - bpo-31249(20): concurrent.futures: WorkItem.run() used by
     ThreadPoolExecutor now breaks a reference cycle between an
     exception object and the WorkItem object.

   - bpo-31247(21): xmlrpc.server now explicitly breaks reference cycles
     when using sys.exc_info() in code handling exceptions.

   - bpo-30102(22): The ssl and hashlib modules now call
     OPENSSL_add_all_algorithms_noconf() on OpenSSL < 1.1.0.  The
     function detects CPU features and enables optimizations on some CPU
     architectures such as POWER8.  Patch is based on research from
     Gustavo Serra Scalet.

   - bpo-31185(23): Fixed miscellaneous errors in asyncio speedup
     module.

   - bpo-31135(24): ttk: fix the destroy() method of LabeledScale and
     OptionMenu classes.  Call the parent destroy() method even if the
     used attribute doesn’t exist.  The LabeledScale.destroy() method
     now also explicitly clears label and scale attributes to help the
     garbage collector to destroy all widgets.

   - bpo-31107(25): Fix ‘copyreg._slotnames()’ mangled attribute
     calculation for classes whose name begins with an underscore.
     Patch by Shane Harvey.

   - bpo-31061(26): Fixed a crash when using asyncio and threads.

   - bpo-30502(27): Fix handling of long oids in ssl.  Based on patch by
     Christian Heimes.

   - bpo-30119(28): ftplib.FTP.putline() now throws ValueError on
     commands that contains CR or LF. Patch by Donghee Na.

   - bpo-30595(29): multiprocessing.Queue.get() with a timeout now polls
     its reader in non-blocking mode if it succeeded to acquire the lock
     but the acquire took longer than the timeout.

   - bpo-29403(30): Fix ‘unittest.mock’’s autospec to not fail on
     method-bound builtin functions.  Patch by Aaron Gallagher.

   - bpo-30961(31): Fix decrementing a borrowed reference in
     tracemalloc.

   - bpo-25684(32): Change ‘ttk.OptionMenu’ radiobuttons to be unique
     across instances of ‘OptionMenu’.

   - bpo-30886(33): Fix multiprocessing.Queue.join_thread(): it now
     waits until the thread completes, even if the thread was started by
     the same process which created the queue.

   - bpo-29854(34): Fix segfault in readline when using readline’s
     history-size option.  Patch by Nir Soffer.

   - bpo-30319(35): socket.close() now ignores ECONNRESET error.

   - bpo-30828(36): Fix out of bounds write in
     ‘asyncio.CFuture.remove_done_callback()’.

   - bpo-30807(37): signal.setitimer() may disable the timer when passed
     a tiny value.  Tiny values (such as 1e-6) are valid non-zero values
     for setitimer(), which is specified as taking
     microsecond-resolution intervals.  However, on some platform, our
     conversion routine could convert 1e-6 into a zero interval,
     therefore disabling the timer instead of (re-)scheduling it.

   - bpo-30441(38): Fix bug when modifying os.environ while iterating
     over it

   - bpo-30532(39): Fix email header value parser dropping folding white
     space in certain cases.

   - bpo-30879(40): os.listdir() and os.scandir() now emit bytes names
     when called with bytes-like argument.

   - bpo-30746(41): Prohibited the “=” character in environment variable
     names in ‘os.putenv()’ and ‘os.spawn*()’.

   - bpo-29755(42): Fixed the lgettext() family of functions in the
     gettext module.  They now always return bytes.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31499

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31544

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31234

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31457

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31400

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28958

   (9) https://bugs.python.org/issue?@action=redirect&bpo=27340

   (10) https://bugs.python.org/issue?@action=redirect&bpo=31178

   (11) https://bugs.python.org/issue?@action=redirect&bpo=31350

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31170

   (13) https://bugs.python.org/issue?@action=redirect&bpo=29136

   (14) https://bugs.python.org/issue?@action=redirect&bpo=29212

   (15) https://bugs.python.org/issue?@action=redirect&bpo=9146

   (16) https://bugs.python.org/issue?@action=redirect&bpo=27144

   (17) https://bugs.python.org/issue?@action=redirect&bpo=10746

   (18) https://peps.python.org/pep-3118/

   (19) https://bugs.python.org/issue?@action=redirect&bpo=22536

   (20) https://bugs.python.org/issue?@action=redirect&bpo=31249

   (21) https://bugs.python.org/issue?@action=redirect&bpo=31247

   (22) https://bugs.python.org/issue?@action=redirect&bpo=30102

   (23) https://bugs.python.org/issue?@action=redirect&bpo=31185

   (24) https://bugs.python.org/issue?@action=redirect&bpo=31135

   (25) https://bugs.python.org/issue?@action=redirect&bpo=31107

   (26) https://bugs.python.org/issue?@action=redirect&bpo=31061

   (27) https://bugs.python.org/issue?@action=redirect&bpo=30502

   (28) https://bugs.python.org/issue?@action=redirect&bpo=30119

   (29) https://bugs.python.org/issue?@action=redirect&bpo=30595

   (30) https://bugs.python.org/issue?@action=redirect&bpo=29403

   (31) https://bugs.python.org/issue?@action=redirect&bpo=30961

   (32) https://bugs.python.org/issue?@action=redirect&bpo=25684

   (33) https://bugs.python.org/issue?@action=redirect&bpo=30886

   (34) https://bugs.python.org/issue?@action=redirect&bpo=29854

   (35) https://bugs.python.org/issue?@action=redirect&bpo=30319

   (36) https://bugs.python.org/issue?@action=redirect&bpo=30828

   (37) https://bugs.python.org/issue?@action=redirect&bpo=30807

   (38) https://bugs.python.org/issue?@action=redirect&bpo=30441

   (39) https://bugs.python.org/issue?@action=redirect&bpo=30532

   (40) https://bugs.python.org/issue?@action=redirect&bpo=30879

   (41) https://bugs.python.org/issue?@action=redirect&bpo=30746

   (42) https://bugs.python.org/issue?@action=redirect&bpo=29755


File: python.info,  Node: Documentation<69>,  Next: Tests<67>,  Prev: Library<177>,  Up: Python 3 6 3 release candidate 1

1.24.80.4 Documentation
.......................

   - bpo-31294(1): Fix incomplete code snippet in the
     ZeroMQSocketListener and ZeroMQSocketHandler examples and adapt
     them to Python 3.

   - bpo-21649(2): Add RFC 7525 and Mozilla server side TLS links to SSL
     documentation.

   - bpo-30803(3): Clarify doc on truth value testing.  Original patch
     by Peter Thomassen.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31294

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21649

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30803


File: python.info,  Node: Tests<67>,  Next: Build<76>,  Prev: Documentation<69>,  Up: Python 3 6 3 release candidate 1

1.24.80.5 Tests
...............

   - bpo-31320(1): Silence traceback in test_ssl

   - bpo-25674(2): Remove sha256.tbs-internet.com ssl test

   - bpo-30715(3): Address ALPN callback changes for OpenSSL 1.1.0f.
     The latest version behaves like OpenSSL 1.0.2 and no longer aborts
     handshake.

   - bpo-30822(4): regrtest: Exclude tzdata from regrtest –all.  When
     running the test suite using –use=all / -u all, exclude tzdata
     since it makes test_datetime too slow (15-20 min on some buildbots)
     which then times out on some buildbots.  Fix also regrtest command
     line parser to allow passing -u extralargefile to run
     test_zipfile64.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31320

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25674

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30715

   (4) https://bugs.python.org/issue?@action=redirect&bpo=30822


File: python.info,  Node: Build<76>,  Next: Windows<66>,  Prev: Tests<67>,  Up: Python 3 6 3 release candidate 1

1.24.80.6 Build
...............

   - bpo-30854(1): Fix compile error when compiling –without-threads.
     Patch by Masayuki Yamamoto.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30854


File: python.info,  Node: Windows<66>,  Next: IDLE<49>,  Prev: Build<76>,  Up: Python 3 6 3 release candidate 1

1.24.80.7 Windows
.................

   - bpo-30389(1): Adds detection of Visual Studio 2017 to distutils on
     Windows.

   - bpo-31340(2): Change to building with MSVC v141 (included with
     Visual Studio 2017)

   - bpo-30581(3): os.cpu_count() now returns the correct number of
     processors on Windows when the number of logical processors is
     greater than 64.

   - bpo-30731(4): Add a missing xmlns to python.manifest so that it
     matches the schema.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30389

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31340

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30581

   (4) https://bugs.python.org/issue?@action=redirect&bpo=30731


File: python.info,  Node: IDLE<49>,  Next: Tools/Demos<47>,  Prev: Windows<66>,  Up: Python 3 6 3 release candidate 1

1.24.80.8 IDLE
..............

   - bpo-31493(1): IDLE code context – fix code update and font update
     timers.  Canceling timers prevents a warning message when test_idle
     completes.

   - bpo-31488(2): IDLE - Update non-key options in former extension
     classes.  When applying configdialog changes, call .reload for each
     feature class.  Change ParenMatch so updated options affect
     existing instances attached to existing editor windows.

   - bpo-31477(3): IDLE - Improve rstrip entry in doc.  Strip trailing
     whitespace strips more than blank spaces.  Multiline string
     literals are not skipped.

   - bpo-31480(4): IDLE - make tests pass with zzdummy extension
     disabled by default.

   - bpo-31421(5): Document how IDLE runs tkinter programs.  IDLE calls
     tcl/tk update in the background in order to make live interaction
     and experimentation with tkinter applications much easier.

   - bpo-31414(6): IDLE – fix tk entry box tests by deleting first.
     Adding to an int entry is not the same as deleting and inserting
     because int(“”) will fail.

   - bpo-31051(7): Rearrange IDLE configdialog GenPage into Window,
     Editor, and Help sections.

   - bpo-30617(8): IDLE - Add docstrings and tests for outwin subclass
     of editor.  Move some data and functions from the class to module
     level.  Patch by Cheryl Sabella.

   - bpo-31287(9): IDLE - Do not modify tkinter.message in
     test_configdialog.

   - bpo-27099(10): Convert IDLE’s built-in “extensions” to regular
     features.  About 10 IDLE features were implemented as supposedly
     optional extensions.  Their different behavior could be confusing
     or worse for users and not good for maintenance.  Hence the
     conversion.  The main difference for users is that user
     configurable key bindings for builtin features are now handled
     uniformly.  Now, editing a binding in a keyset only affects its
     value in the keyset.  All bindings are defined together in the
     system-specific default keysets in config-extensions.def.  All
     custom keysets are saved as a whole in config-extension.cfg.  All
     take effect as soon as one clicks Apply or Ok.  The affected events
     are “<<force-open-completions>>”, “<<expand-word>>”,
     “<<force-open-calltip>>”, “<<flash-paren>>”,
     “<<format-paragraph>>”, “<<run-module>>”, “<<check-module>>”, and
     “<<zoom-height>>”.  Any (global) customizations made before 3.6.3
     will not affect their keyset-specific customization after 3.6.3.
     and vice versa.  Initial patch by Charles Wohlganger.

   - bpo-31206(11): IDLE: Factor HighPage(Frame) class from
     ConfigDialog.  Patch by Cheryl Sabella.

   - bpo-31001(12): Add tests for configdialog highlight tab.  Patch by
     Cheryl Sabella.

   - bpo-31205(13): IDLE: Factor KeysPage(Frame) class from
     ConfigDialog.  The slightly modified tests continue to pass.  Patch
     by Cheryl Sabella.

   - bpo-31130(14): IDLE – stop leaks in test_configdialog.  Initial
     patch by Victor Stinner.

   - bpo-31002(15): Add tests for configdialog keys tab.  Patch by
     Cheryl Sabella.

   - bpo-19903(16): IDLE: Calltips use ‘inspect.signature’ instead of
     ‘inspect.getfullargspec’.  This improves calltips for builtins
     converted to use Argument Clinic.  Patch by Louie Lu.

   - bpo-31083(17): IDLE - Add an outline of a TabPage class in
     configdialog.  Update existing classes to match outline.  Initial
     patch by Cheryl Sabella.

   - bpo-31050(18): Factor GenPage(Frame) class from ConfigDialog.  The
     slightly modified tests continue to pass.  Patch by Cheryl Sabella.

   - bpo-31004(19): IDLE - Factor FontPage(Frame) class from
     ConfigDialog.  Slightly modified tests continue to pass.  Fix
     General tests.  Patch mostly by Cheryl Sabella.

   - bpo-30781(20): IDLE - Use ttk widgets in ConfigDialog.  Patches by
     Terry Jan Reedy and Cheryl Sabella.

   - bpo-31060(21): IDLE - Finish rearranging methods of ConfigDialog
     Grouping methods pertaining to each tab and the buttons will aid
     writing tests and improving the tabs and will enable splitting the
     groups into classes.

   - bpo-30853(22): IDLE – Factor a VarTrace class out of ConfigDialog.
     Instance tracers manages pairs consisting of a tk variable and a
     callback function.  When tracing is turned on, setting the variable
     calls the function.  Test coverage for the new class is 100%.

   - bpo-31003(23): IDLE: Add more tests for General tab.

   - bpo-30993(24): IDLE - Improve configdialog font page and tests.  In
     configdialog: Document causal pathways in create_font_tab
     docstring.  Simplify some attribute names.  Move set_samples calls
     to var_changed_font (idea from Cheryl Sabella).  Move related
     functions to positions after the create widgets function.  In
     test_configdialog: Fix test_font_set so not order dependent.  Fix
     renamed test_indent_scale so it tests the widget.  Adjust tests for
     movement of set_samples call.  Add tests for load functions.  Put
     all font tests in one class and tab indent tests in another.
     Except for two lines, these tests completely cover the related
     functions.

   - bpo-30981(25): IDLE – Add more configdialog font page tests.

   - bpo-28523(26): IDLE: replace “colour” with “color” in configdialog.

   - bpo-30917(27): Add tests for idlelib.config.IdleConf.  Increase
     coverage from 46% to 96%.  Patch by Louie Lu.

   - bpo-30934(28): Document coverage details for idlelib tests.  Add
     section to idlelib/idle-test/README.txt.  Include check that
     branches are taken both ways.  Exclude IDLE-specific code that does
     not run during unit tests.

   - bpo-30913(29): IDLE: Document ConfigDialog tk Vars, methods, and
     widgets in docstrings This will facilitate improving the dialog and
     splitting up the class.  Original patch by Cheryl Sabella.

   - bpo-30899(30): IDLE: Add tests for ConfigParser subclasses in
     config.  Patch by Louie Lu.

   - bpo-30881(31): IDLE: Add docstrings to browser.py.  Patch by Cheryl
     Sabella.

   - bpo-30851(32): IDLE: Remove unused variables in configdialog.  One
     is a duplicate, one is set but cannot be altered by users.  Patch
     by Cheryl Sabella.

   - bpo-30870(33): IDLE: In Settings dialog, select font with Up, Down
     keys as well as mouse.  Initial patch by Louie Lu.

   - bpo-8231(34): IDLE: call config.IdleConf.GetUserCfgDir only once.

   - bpo-30779(35): IDLE: Factor ConfigChanges class from configdialog,
     put in config; test.  * In config, put dump test code in a
     function; run it and unittest in “if __name__ == “__main__”.  * Add
     class config.ConfigChanges based on changes_class_v4.py on bpo
     issue.  * Add class test_config.ChangesTest, partly using
     configdialog_tests_v1.py.  * Revise configdialog to use
     ConfigChanges; see tracker msg297804.  * Revise test_configdialog
     to match configdialog changes.  * Remove configdialog functions
     unused or moved to ConfigChanges.  Cheryl Sabella contributed parts
     of the patch.

   - bpo-30777(36): IDLE: configdialog - Add docstrings and fix
     comments.  Patch by Cheryl Sabella.

   - bpo-30495(37): IDLE: Improve textview with docstrings, PEP8 names,
     and more tests.  Patch by Cheryl Sabella.

   - bpo-30723(38): IDLE: Make several improvements to parenmatch.  Add
     “parens” style to highlight both opener and closer.  Make “default”
     style, which is not default, a synonym for “opener”.  Make
     time-delay work the same with all styles.  Add help for config
     dialog extensions tab, including help for parenmatch.  Add new
     tests.  Original patch by Charles Wohlganger.

   - bpo-30674(39): IDLE: add docstrings to grep module.  Patch by
     Cheryl Sabella

   - bpo-21519(40): IDLE’s basic custom key entry dialog now detects
     duplicates properly.  Original patch by Saimadhav Heblikar.

   - bpo-29910(41): IDLE no longer deletes a character after commenting
     out a region by a key shortcut.  Add ‘return 'break'’ for this and
     other potential conflicts between IDLE and default key bindings.

   - bpo-30728(42): Review and change idlelib.configdialog names.
     Lowercase method and attribute names.  Replace “colour” with
     “color”, expand overly cryptic names, delete unneeded underscores.
     Replace ‘import *’ with specific imports.  Patches by Cheryl
     Sabella.

   - bpo-6739(43): IDLE: Verify user-entered key sequences by trying to
     bind them with tk.  Add tests for all 3 validation functions.
     Original patch by G Polo.  Tests added by Cheryl Sabella.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31493

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31488

   (3) https://bugs.python.org/issue?@action=redirect&bpo=31477

   (4) https://bugs.python.org/issue?@action=redirect&bpo=31480

   (5) https://bugs.python.org/issue?@action=redirect&bpo=31421

   (6) https://bugs.python.org/issue?@action=redirect&bpo=31414

   (7) https://bugs.python.org/issue?@action=redirect&bpo=31051

   (8) https://bugs.python.org/issue?@action=redirect&bpo=30617

   (9) https://bugs.python.org/issue?@action=redirect&bpo=31287

   (10) https://bugs.python.org/issue?@action=redirect&bpo=27099

   (11) https://bugs.python.org/issue?@action=redirect&bpo=31206

   (12) https://bugs.python.org/issue?@action=redirect&bpo=31001

   (13) https://bugs.python.org/issue?@action=redirect&bpo=31205

   (14) https://bugs.python.org/issue?@action=redirect&bpo=31130

   (15) https://bugs.python.org/issue?@action=redirect&bpo=31002

   (16) https://bugs.python.org/issue?@action=redirect&bpo=19903

   (17) https://bugs.python.org/issue?@action=redirect&bpo=31083

   (18) https://bugs.python.org/issue?@action=redirect&bpo=31050

   (19) https://bugs.python.org/issue?@action=redirect&bpo=31004

   (20) https://bugs.python.org/issue?@action=redirect&bpo=30781

   (21) https://bugs.python.org/issue?@action=redirect&bpo=31060

   (22) https://bugs.python.org/issue?@action=redirect&bpo=30853

   (23) https://bugs.python.org/issue?@action=redirect&bpo=31003

   (24) https://bugs.python.org/issue?@action=redirect&bpo=30993

   (25) https://bugs.python.org/issue?@action=redirect&bpo=30981

   (26) https://bugs.python.org/issue?@action=redirect&bpo=28523

   (27) https://bugs.python.org/issue?@action=redirect&bpo=30917

   (28) https://bugs.python.org/issue?@action=redirect&bpo=30934

   (29) https://bugs.python.org/issue?@action=redirect&bpo=30913

   (30) https://bugs.python.org/issue?@action=redirect&bpo=30899

   (31) https://bugs.python.org/issue?@action=redirect&bpo=30881

   (32) https://bugs.python.org/issue?@action=redirect&bpo=30851

   (33) https://bugs.python.org/issue?@action=redirect&bpo=30870

   (34) https://bugs.python.org/issue?@action=redirect&bpo=8231

   (35) https://bugs.python.org/issue?@action=redirect&bpo=30779

   (36) https://bugs.python.org/issue?@action=redirect&bpo=30777

   (37) https://bugs.python.org/issue?@action=redirect&bpo=30495

   (38) https://bugs.python.org/issue?@action=redirect&bpo=30723

   (39) https://bugs.python.org/issue?@action=redirect&bpo=30674

   (40) https://bugs.python.org/issue?@action=redirect&bpo=21519

   (41) https://bugs.python.org/issue?@action=redirect&bpo=29910

   (42) https://bugs.python.org/issue?@action=redirect&bpo=30728

   (43) https://bugs.python.org/issue?@action=redirect&bpo=6739


File: python.info,  Node: Tools/Demos<47>,  Prev: IDLE<49>,  Up: Python 3 6 3 release candidate 1

1.24.80.9 Tools/Demos
.....................

   - bpo-30983(1): gdb integration commands (py-bt, etc.)  work on
     optimized shared builds now, too.  PEP 523(2) introduced
     _PyEval_EvalFrameDefault which inlines PyEval_EvalFrameEx on
     non-debug shared builds.  This broke the ability to use py-bt,
     py-up, and a few other Python-specific gdb integrations.  The
     problem is fixed by only looking for _PyEval_EvalFrameDefault
     frames in python-gdb.py.  Original patch by Bruno «Polaco»
     Penteado.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30983

   (2) https://peps.python.org/pep-0523/


File: python.info,  Node: Python 3 6 2 final,  Next: Python 3 6 2 release candidate 2,  Prev: Python 3 6 3 release candidate 1,  Up: Changelog

1.24.81 Python 3.6.2 final
--------------------------

'Release date: 2017-07-17'

No changes since release candidate 2


File: python.info,  Node: Python 3 6 2 release candidate 2,  Next: Python 3 6 2 release candidate 1,  Prev: Python 3 6 2 final,  Up: Changelog

1.24.82 Python 3.6.2 release candidate 2
----------------------------------------

'Release date: 2017-07-07'

* Menu:

* Security: Security<52>.


File: python.info,  Node: Security<52>,  Up: Python 3 6 2 release candidate 2

1.24.82.1 Security
..................

   - bpo-30730(1): Prevent environment variables injection in subprocess
     on Windows.  Prevent passing other environment variables and
     command arguments.

   - bpo-30694(2): Upgrade expat copy from 2.2.0 to 2.2.1 to get fixes
     of multiple security vulnerabilities including: CVE 2017-9233(3)
     (External entity infinite loop DoS), CVE 2016-9063(4) (Integer
     overflow, re-fix), CVE 2016-0718(5) (Fix regression bugs from
     2.2.0’s fix to CVE 2016-0718(6)) and CVE 2012-0876(7) (Counter hash
     flooding with SipHash).  Note: the CVE 2016-5300(8) (Use
     os-specific entropy sources like getrandom) doesn’t impact Python,
     since Python already gets entropy from the OS to set the expat
     secret using ‘XML_SetHashSalt()’.

   - bpo-30500(9): Fix urllib.parse.splithost() to correctly parse
     fragments.  For example, ‘splithost('//127.0.0.1#@evil.com/')’ now
     correctly returns the ‘127.0.0.1’ host, instead of treating
     ‘@evil.com’ as the host in an authentication (‘login@host’).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30730

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30694

   (3) https://www.cve.org/CVERecord?id=CVE-2017-9233

   (4) https://www.cve.org/CVERecord?id=CVE-2016-9063

   (5) https://www.cve.org/CVERecord?id=CVE-2016-0718

   (6) https://www.cve.org/CVERecord?id=CVE-2016-0718

   (7) https://www.cve.org/CVERecord?id=CVE-2012-0876

   (8) https://www.cve.org/CVERecord?id=CVE-2016-5300

   (9) https://bugs.python.org/issue?@action=redirect&bpo=30500


File: python.info,  Node: Python 3 6 2 release candidate 1,  Next: Python 3 6 1 final,  Prev: Python 3 6 2 release candidate 2,  Up: Changelog

1.24.83 Python 3.6.2 release candidate 1
----------------------------------------

'Release date: 2017-06-17'

* Menu:

* Security: Security<53>.
* Core and Builtins: Core and Builtins<173>.
* Library: Library<178>.
* IDLE: IDLE<50>.
* C API: C API<67>.
* Build: Build<77>.
* Documentation: Documentation<70>.
* Tools/Demos: Tools/Demos<48>.
* Tests: Tests<68>.
* Windows: Windows<67>.


File: python.info,  Node: Security<53>,  Next: Core and Builtins<173>,  Up: Python 3 6 2 release candidate 1

1.24.83.1 Security
..................

   - bpo-29591(1): Update expat copy from 2.1.1 to 2.2.0 to get fixes of
     CVE 2016-0718(2) and CVE 2016-4472(3).  See
     ‘https://sourceforge.net/p/expat/bugs/537/’ for more information.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29591

   (2) https://www.cve.org/CVERecord?id=CVE-2016-0718

   (3) https://www.cve.org/CVERecord?id=CVE-2016-4472


File: python.info,  Node: Core and Builtins<173>,  Next: Library<178>,  Prev: Security<53>,  Up: Python 3 6 2 release candidate 1

1.24.83.2 Core and Builtins
...........................

   - bpo-30682(1): Removed a too-strict assertion that failed for
     certain f-strings, such as eval(«f”\n”») and eval(«f”\r”»).

   - bpo-30604(2): Move co_extra_freefuncs to not be per-thread to avoid
     crashes

   - bpo-29104(3): Fixed parsing backslashes in f-strings.

   - bpo-27945(4): Fixed various segfaults with dict when input
     collections are mutated during searching, inserting or comparing.
     Based on patches by Duane Griffin and Tim Mitchell.

   - bpo-25794(5): Fixed type.__setattr__() and type.__delattr__() for
     non-interned attribute names.  Based on patch by Eryk Sun.

   - bpo-30039(6): If a KeyboardInterrupt happens when the interpreter
     is in the middle of resuming a chain of nested “yield from” or
     “await” calls, it’s now correctly delivered to the innermost frame.

   - bpo-12414(7): sys.getsizeof() on a code object now returns the
     sizes which includes the code struct and sizes of objects which it
     references.  Patch by Donghee Na.

   - bpo-29949(8): Fix memory usage regression of set and frozenset
     object.

   - bpo-29935(9): Fixed error messages in the index() method of tuple,
     list and deque when pass indices of wrong type.

   - bpo-29859(10): Show correct error messages when any of the
     pthread_* calls in thread_pthread.h fails.

   - bpo-28876(11): ‘bool(range)’ works even if ‘len(range)’ raises
     *note OverflowError: a83.

   - bpo-29600(12): Fix wrapping coroutine return values in
     StopIteration.

   - bpo-28856(13): Fix an oversight that %b format for bytes should
     support objects follow the buffer protocol.

   - bpo-29714(14): Fix a regression that bytes format may fail when
     containing zero bytes inside.

   - bpo-29478(15): If max_line_length=None is specified while using the
     Compat32 policy, it is no longer ignored.  Patch by Mircea Cosbuc.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30682

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30604

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29104

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27945

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25794

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30039

   (7) https://bugs.python.org/issue?@action=redirect&bpo=12414

   (8) https://bugs.python.org/issue?@action=redirect&bpo=29949

   (9) https://bugs.python.org/issue?@action=redirect&bpo=29935

   (10) https://bugs.python.org/issue?@action=redirect&bpo=29859

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28876

   (12) https://bugs.python.org/issue?@action=redirect&bpo=29600

   (13) https://bugs.python.org/issue?@action=redirect&bpo=28856

   (14) https://bugs.python.org/issue?@action=redirect&bpo=29714

   (15) https://bugs.python.org/issue?@action=redirect&bpo=29478


File: python.info,  Node: Library<178>,  Next: IDLE<50>,  Prev: Core and Builtins<173>,  Up: Python 3 6 2 release candidate 1

1.24.83.3 Library
.................

   - bpo-30616(1): Functional API of enum allows to create empty enums.
     Patched by Donghee Na

   - bpo-30038(2): Fix race condition between signal delivery and wakeup
     file descriptor.  Patch by Nathaniel Smith.

   - bpo-23894(3): lib2to3 now recognizes ‘rb'...'’ and ‘f'...'’
     strings.

   - bpo-23890(4): unittest.TestCase.assertRaises() now manually breaks
     a reference cycle to not keep objects alive longer than expected.

   - bpo-30149(5): inspect.signature() now supports callables with
     variable-argument parameters wrapped with partialmethod.  Patch by
     Donghee Na.

   - bpo-30645(6): Fix path calculation in imp.load_package(), fixing it
     for cases when a package is only shipped with bytecodes.  Patch by
     Alexandru Ardelean.

   - bpo-29931(7): Fixed comparison check for ipaddress.ip_interface
     objects.  Patch by Sanjay Sundaresan.

   - bpo-30605(8): re.compile() no longer raises a BytesWarning when
     compiling a bytes instance with misplaced inline modifier.  Patch
     by Roy Williams.

   - bpo-24484(9): Avoid race condition in multiprocessing cleanup
     (#2159)

   - bpo-28994(10): The traceback no longer displayed for SystemExit
     raised in a callback registered by atexit.

   - bpo-30508(11): Don’t log exceptions if Task/Future «cancel()»
     method was called.

   - bpo-28556(12): Updates to typing module: Add generic
     AsyncContextManager, add support for ContextManager on all
     versions.  Original PRs by Jelle Zijlstra and Ivan Levkivskyi

   - bpo-29870(13): Fix ssl sockets leaks when connection is aborted in
     asyncio/ssl implementation.  Patch by Michaël Sghaïer.

   - bpo-29743(14): Closing transport during handshake process leaks
     open socket.  Patch by Nikolay Kim

   - bpo-27585(15): Fix waiter cancellation in asyncio.Lock.  Patch by
     Mathieu Sornay.

   - bpo-30418(16): On Windows, subprocess.Popen.communicate() now also
     ignore EINVAL on stdin.write() if the child process is still
     running but closed the pipe.

   - bpo-29822(17): inspect.isabstract() now works during
     __init_subclass__.  Patch by Nate Soares.

   - bpo-29581(18): ABCMeta.__new__ now accepts ‘**kwargs’, allowing
     abstract base classes to use keyword parameters in
     __init_subclass__.  Patch by Nate Soares.

   - bpo-30557(19): faulthandler now correctly filters and displays
     exception codes on Windows

   - bpo-30378(20): Fix the problem that logging.handlers.SysLogHandler
     cannot handle IPv6 addresses.

   - bpo-29960(21): Preserve generator state when
     _random.Random.setstate() raises an exception.  Patch by Bryan
     Olson.

   - bpo-30414(22): multiprocessing.Queue._feed background running
     thread do not break from main loop on exception.

   - bpo-30003(23): Fix handling escape characters in HZ codec.  Based
     on patch by Ma Lin.

   - bpo-30301(24): Fix AttributeError when using SimpleQueue.empty()
     under 'spawn' and 'forkserver' start methods.

   - bpo-30329(25): imaplib and poplib now catch the Windows socket
     WSAEINVAL error (code 10022) on shutdown(SHUT_RDWR): An invalid
     operation was attempted.  This error occurs sometimes on SSL
     connections.

   - bpo-30375(26): Warnings emitted when compile a regular expression
     now always point to the line in the user code.  Previously they
     could point into inners of the re module if emitted from inside of
     groups or conditionals.

   - bpo-30048(27): Fixed ‘Task.cancel()’ can be ignored when the task
     is running coroutine and the coroutine returned without any more
     ‘await’.

   - bpo-30266(28): contextlib.AbstractContextManager now supports
     anti-registration by setting __enter__ = None or __exit__ = None,
     following the pattern introduced in bpo-25958(29).  Patch by Jelle
     Zijlstra.

   - bpo-30298(30): Weaken the condition of deprecation warnings for
     inline modifiers.  Now allowed several subsequential inline
     modifiers at the start of the pattern (e.g.  ‘'(?i)(?s)...'’).  In
     verbose mode whitespaces and comments now are allowed before and
     between inline modifiers (e.g.  ‘'(?x) (?i) (?s)...'’).

   - bpo-29990(31): Fix range checking in GB18030 decoder.  Original
     patch by Ma Lin.

   - bpo-26293(32): Change resulted because of zipfile breakage.  (See
     also: bpo-29094(33))

   - bpo-30243(34): Removed the __init__ methods of _json’s scanner and
     encoder.  Misusing them could cause memory leaks or crashes.  Now
     scanner and encoder objects are completely initialized in the
     __new__ methods.

   - bpo-30185(35): Avoid KeyboardInterrupt tracebacks in forkserver
     helper process when Ctrl-C is received.

   - bpo-28556(36): Various updates to typing module: add
     typing.NoReturn type, use WrapperDescriptorType, minor bug-fixes.
     Original PRs by Jim Fasarakis-Hilliard and Ivan Levkivskyi.

   - bpo-30205(37): Fix getsockname() for unbound AF_UNIX sockets on
     Linux.

   - bpo-30070(38): Fixed leaks and crashes in errors handling in the
     parser module.

   - bpo-30061(39): Fixed crashes in IOBase methods __next__() and
     readlines() when readline() or __next__() respectively return
     non-sizeable object.  Fixed possible other errors caused by not
     checking results of PyObject_Size(), PySequence_Size(), or
     PyMapping_Size().

   - bpo-30017(40): Allowed calling the close() method of the zip entry
     writer object multiple times.  Writing to a closed writer now
     always produces a ValueError.

   - bpo-30068(41): _io._IOBase.readlines will check if it’s closed
     first when hint is present.

   - bpo-29694(42): Fixed race condition in pathlib mkdir with flags
     parents=True.  Patch by Armin Rigo.

   - bpo-29692(43): Fixed arbitrary unchaining of RuntimeError
     exceptions in contextlib.contextmanager.  Patch by Siddharth
     Velankar.

   - bpo-29998(44): Pickling and copying ImportError now preserves name
     and path attributes.

   - bpo-29953(45): Fixed memory leaks in the replace() method of
     datetime and time objects when pass out of bound fold argument.

   - bpo-29942(46): Fix a crash in itertools.chain.from_iterable when
     encountering long runs of empty iterables.

   - bpo-27863(47): Fixed multiple crashes in ElementTree caused by race
     conditions and wrong types.

   - bpo-28699(48): Fixed a bug in pools in multiprocessing.pool that
     raising an exception at the very first of an iterable may swallow
     the exception or make the program hang.  Patch by Davin Potts and
     Xiang Zhang.

   - bpo-25803(49): Avoid incorrect errors raised by
     Path.mkdir(exist_ok=True) when the OS gives priority to errors such
     as EACCES over EEXIST.

   - bpo-29861(50): Release references to tasks, their arguments and
     their results as soon as they are finished in multiprocessing.Pool.

   - bpo-29884(51): faulthandler: Restore the old sigaltstack during
     teardown.  Patch by Christophe Zeitouny.

   - bpo-25455(52): Fixed crashes in repr of recursive buffered
     file-like objects.

   - bpo-29800(53): Fix crashes in partial.__repr__ if the keys of
     partial.keywords are not strings.  Patch by Michael Seifert.

   - bpo-29742(54): get_extra_info() raises exception if get called on
     closed ssl transport.  Patch by Nikolay Kim.

   - bpo-8256(55): Fixed possible failing or crashing input() if
     attributes «encoding» or «errors» of sys.stdin or sys.stdout are
     not set or are not strings.

   - bpo-28298(56): Fix a bug that prevented array “Q”, “L” and “I” from
     accepting big intables (objects that have __int__) as elements.
     Patch by Oren Milman.

   - bpo-28231(57): The zipfile module now accepts path-like objects for
     external paths.

   - bpo-26915(58): index() and count() methods of
     collections.abc.Sequence now check identity before checking
     equality when do comparisons.

   - bpo-29615(59): SimpleXMLRPCDispatcher no longer chains KeyError (or
     any other exception) to exception(s) raised in the dispatched
     methods.  Patch by Petr Motejlek.

   - bpo-30177(60): path.resolve(strict=False) no longer cuts the path
     after the first element not present in the filesystem.  Patch by
     Antoine Pietri.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30616

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30038

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23894

   (4) https://bugs.python.org/issue?@action=redirect&bpo=23890

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30149

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30645

   (7) https://bugs.python.org/issue?@action=redirect&bpo=29931

   (8) https://bugs.python.org/issue?@action=redirect&bpo=30605

   (9) https://bugs.python.org/issue?@action=redirect&bpo=24484

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28994

   (11) https://bugs.python.org/issue?@action=redirect&bpo=30508

   (12) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (13) https://bugs.python.org/issue?@action=redirect&bpo=29870

   (14) https://bugs.python.org/issue?@action=redirect&bpo=29743

   (15) https://bugs.python.org/issue?@action=redirect&bpo=27585

   (16) https://bugs.python.org/issue?@action=redirect&bpo=30418

   (17) https://bugs.python.org/issue?@action=redirect&bpo=29822

   (18) https://bugs.python.org/issue?@action=redirect&bpo=29581

   (19) https://bugs.python.org/issue?@action=redirect&bpo=30557

   (20) https://bugs.python.org/issue?@action=redirect&bpo=30378

   (21) https://bugs.python.org/issue?@action=redirect&bpo=29960

   (22) https://bugs.python.org/issue?@action=redirect&bpo=30414

   (23) https://bugs.python.org/issue?@action=redirect&bpo=30003

   (24) https://bugs.python.org/issue?@action=redirect&bpo=30301

   (25) https://bugs.python.org/issue?@action=redirect&bpo=30329

   (26) https://bugs.python.org/issue?@action=redirect&bpo=30375

   (27) https://bugs.python.org/issue?@action=redirect&bpo=30048

   (28) https://bugs.python.org/issue?@action=redirect&bpo=30266

   (29) https://bugs.python.org/issue?@action=redirect&bpo=25958

   (30) https://bugs.python.org/issue?@action=redirect&bpo=30298

   (31) https://bugs.python.org/issue?@action=redirect&bpo=29990

   (32) https://bugs.python.org/issue?@action=redirect&bpo=26293

   (33) https://bugs.python.org/issue?@action=redirect&bpo=29094

   (34) https://bugs.python.org/issue?@action=redirect&bpo=30243

   (35) https://bugs.python.org/issue?@action=redirect&bpo=30185

   (36) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (37) https://bugs.python.org/issue?@action=redirect&bpo=30205

   (38) https://bugs.python.org/issue?@action=redirect&bpo=30070

   (39) https://bugs.python.org/issue?@action=redirect&bpo=30061

   (40) https://bugs.python.org/issue?@action=redirect&bpo=30017

   (41) https://bugs.python.org/issue?@action=redirect&bpo=30068

   (42) https://bugs.python.org/issue?@action=redirect&bpo=29694

   (43) https://bugs.python.org/issue?@action=redirect&bpo=29692

   (44) https://bugs.python.org/issue?@action=redirect&bpo=29998

   (45) https://bugs.python.org/issue?@action=redirect&bpo=29953

   (46) https://bugs.python.org/issue?@action=redirect&bpo=29942

   (47) https://bugs.python.org/issue?@action=redirect&bpo=27863

   (48) https://bugs.python.org/issue?@action=redirect&bpo=28699

   (49) https://bugs.python.org/issue?@action=redirect&bpo=25803

   (50) https://bugs.python.org/issue?@action=redirect&bpo=29861

   (51) https://bugs.python.org/issue?@action=redirect&bpo=29884

   (52) https://bugs.python.org/issue?@action=redirect&bpo=25455

   (53) https://bugs.python.org/issue?@action=redirect&bpo=29800

   (54) https://bugs.python.org/issue?@action=redirect&bpo=29742

   (55) https://bugs.python.org/issue?@action=redirect&bpo=8256

   (56) https://bugs.python.org/issue?@action=redirect&bpo=28298

   (57) https://bugs.python.org/issue?@action=redirect&bpo=28231

   (58) https://bugs.python.org/issue?@action=redirect&bpo=26915

   (59) https://bugs.python.org/issue?@action=redirect&bpo=29615

   (60) https://bugs.python.org/issue?@action=redirect&bpo=30177


File: python.info,  Node: IDLE<50>,  Next: C API<67>,  Prev: Library<178>,  Up: Python 3 6 2 release candidate 1

1.24.83.4 IDLE
..............

   - bpo-15786(1): Fix several problems with IDLE’s autocompletion box.
     The following should now work: clicking on selection box items;
     using the scrollbar; selecting an item by hitting Return.  Hangs on
     MacOSX should no longer happen.  Patch by Louie Lu.

   - bpo-25514(2): Add doc subsubsection about IDLE failure to start.
     Popup no-connection message directs users to this section.

   - bpo-30642(3): Fix reference leaks in IDLE tests.  Patches by Louie
     Lu and Terry Jan Reedy.

   - bpo-30495(4): Add docstrings for textview.py and use PEP8 names.
     Patches by Cheryl Sabella and Terry Jan Reedy.

   - bpo-30290(5): Help-about: use pep8 names and add tests.  Increase
     coverage to 100%.  Patches by Louie Lu, Cheryl Sabella, and Terry
     Jan Reedy.

   - bpo-30303(6): Add _utest option to textview; add new tests.
     Increase coverage to 100%.  Patches by Louie Lu and Terry Jan
     Reedy.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15786

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25514

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30642

   (4) https://bugs.python.org/issue?@action=redirect&bpo=30495

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30290

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30303


File: python.info,  Node: C API<67>,  Next: Build<77>,  Prev: IDLE<50>,  Up: Python 3 6 2 release candidate 1

1.24.83.5 C API
...............

   - bpo-27867(1): Function PySlice_GetIndicesEx() no longer replaced
     with a macro if Py_LIMITED_API is not set.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27867


File: python.info,  Node: Build<77>,  Next: Documentation<70>,  Prev: C API<67>,  Up: Python 3 6 2 release candidate 1

1.24.83.6 Build
...............

   - bpo-29941(1): Add ‘--with-assertions’ configure flag to explicitly
     enable C ‘assert()’ checks.  Defaults to off.  ‘--with-pydebug’
     implies ‘--with-assertions’.

   - bpo-28787(2): Fix out-of-tree builds of Python when configured with
     ‘--with--dtrace’.

   - bpo-29243(3): Prevent unnecessary rebuilding of Python during ‘make
     test’, ‘make install’ and some other make targets when configured
     with ‘--enable-optimizations’.

   - bpo-23404(4): Don’t regenerate generated files based on file
     modification time anymore: the action is now explicit.  Replace
     ‘make touch’ with ‘make regen-all’.

   - bpo-29643(5): Fix ‘--enable-optimization’ didn’t work.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29941

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28787

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29243

   (4) https://bugs.python.org/issue?@action=redirect&bpo=23404

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29643


File: python.info,  Node: Documentation<70>,  Next: Tools/Demos<48>,  Prev: Build<77>,  Up: Python 3 6 2 release candidate 1

1.24.83.7 Documentation
.......................

   - bpo-30176(1): Add missing attribute related constants in curses
     documentation.

   - bpo-30052(2): the link targets for *note bytes(): 192. and *note
     bytearray(): 344. are now their respective type definitions, rather
     than the corresponding builtin function entries.  Use *note bytes:
     1e82. and *note bytearray: 1e83. to reference the latter.  In order
     to ensure this and future cross-reference updates are applied
     automatically, the daily documentation builds now disable the
     default output caching features in Sphinx.

   - bpo-26985(3): Add missing info of code object in inspect
     documentation.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30176

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30052

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26985


File: python.info,  Node: Tools/Demos<48>,  Next: Tests<68>,  Prev: Documentation<70>,  Up: Python 3 6 2 release candidate 1

1.24.83.8 Tools/Demos
.....................

   - bpo-29367(1): python-gdb.py now supports also ‘method-wrapper’
     (‘wrapperobject’) objects.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29367


File: python.info,  Node: Tests<68>,  Next: Windows<67>,  Prev: Tools/Demos<48>,  Up: Python 3 6 2 release candidate 1

1.24.83.9 Tests
...............

   - bpo-30357(1): test_thread: setUp() now uses
     support.threading_setup() and support.threading_cleanup() to wait
     until threads complete to avoid random side effects on following
     tests.  Initial patch written by Grzegorz Grzywacz.

   - bpo-30197(2): Enhanced functions swap_attr() and swap_item() in the
     test.support module.  They now work when delete replaced attribute
     or item inside the with statement.  The old value of the attribute
     or item (or None if it doesn’t exist) now will be assigned to the
     target of the «as» clause, if there is one.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30357

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30197


File: python.info,  Node: Windows<67>,  Prev: Tests<68>,  Up: Python 3 6 2 release candidate 1

1.24.83.10 Windows
..................

   - bpo-30687(1): Locate msbuild.exe on Windows when building rather
     than vcvarsall.bat

   - bpo-30450(2): The build process on Windows no longer depends on
     Subversion, instead pulling external code from GitHub via a Python
     script.  If Python 3.6 is not found on the system (via ‘py -3.6’),
     NuGet is used to download a copy of 32-bit Python.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30687

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30450


File: python.info,  Node: Python 3 6 1 final,  Next: Python 3 6 1 release candidate 1,  Prev: Python 3 6 2 release candidate 1,  Up: Changelog

1.24.84 Python 3.6.1 final
--------------------------

'Release date: 2017-03-21'

* Menu:

* Core and Builtins: Core and Builtins<174>.
* Build: Build<78>.


File: python.info,  Node: Core and Builtins<174>,  Next: Build<78>,  Up: Python 3 6 1 final

1.24.84.1 Core and Builtins
...........................

   - bpo-29723(1): The ‘sys.path[0]’ initialization change for
     bpo-29139(2) caused a regression by revealing an inconsistency in
     how sys.path is initialized when executing ‘__main__’ from a
     zipfile, directory, or other import location.  The interpreter now
     consistently avoids ever adding the import location’s parent
     directory to ‘sys.path’, and ensures no other ‘sys.path’ entries
     are inadvertently modified when inserting the import location named
     on the command line.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29723

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29139


File: python.info,  Node: Build<78>,  Prev: Core and Builtins<174>,  Up: Python 3 6 1 final

1.24.84.2 Build
...............

   - bpo-27593(1): fix format of git information used in sys.version

   - Fix incompatible comment in python.h

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27593


File: python.info,  Node: Python 3 6 1 release candidate 1,  Next: Python 3 6 0 final,  Prev: Python 3 6 1 final,  Up: Changelog

1.24.85 Python 3.6.1 release candidate 1
----------------------------------------

'Release date: 2017-03-04'

* Menu:

* Core and Builtins: Core and Builtins<175>.
* Library: Library<179>.
* IDLE: IDLE<51>.
* Windows: Windows<68>.
* C API: C API<68>.
* Documentation: Documentation<71>.
* Tests: Tests<69>.
* Build: Build<79>.


File: python.info,  Node: Core and Builtins<175>,  Next: Library<179>,  Up: Python 3 6 1 release candidate 1

1.24.85.1 Core and Builtins
...........................

   - bpo-28893(1): Set correct __cause__ for errors about invalid
     awaitables returned from __aiter__ and __anext__.

   - bpo-29683(2): Fixes to memory allocation in _PyCode_SetExtra.
     Patch by Brian Coleman.

   - bpo-29684(3): Fix minor regression of
     PyEval_CallObjectWithKeywords.  It should raise TypeError when
     kwargs is not a dict.  But it might cause segv when args=NULL and
     kwargs is not a dict.

   - bpo-28598(4): Support __rmod__ for subclasses of str being called
     before str.__mod__.  Patch by Martijn Pieters.

   - bpo-29607(5): Fix stack_effect computation for CALL_FUNCTION_EX.
     Patch by Matthieu Dartiailh.

   - bpo-29602(6): Fix incorrect handling of signed zeros in complex
     constructor for complex subclasses and for inputs having a
     __complex__ method.  Patch by Serhiy Storchaka.

   - bpo-29347(7): Fixed possibly dereferencing undefined pointers when
     creating weakref objects.

   - bpo-29438(8): Fixed use-after-free problem in key sharing dict.

   - bpo-29319(9): Prevent RunMainFromImporter overwriting sys.path[0].

   - bpo-29337(10): Fixed possible BytesWarning when compare the code
     objects.  Warnings could be emitted at compile time.

   - bpo-29327(11): Fixed a crash when pass the iterable keyword
     argument to sorted().

   - bpo-29034(12): Fix memory leak and use-after-free in os module
     (path_converter).

   - bpo-29159(13): Fix regression in bytes(x) when x.__index__() raises
     Exception.

   - bpo-28932(14): Do not include <sys/random.h> if it does not exist.

   - bpo-25677(15): Correct the positioning of the syntax error caret
     for indented blocks.  Based on patch by Michael Layzell.

   - bpo-29000(16): Fixed bytes formatting of octals with zero padding
     in alternate form.

   - bpo-26919(17): On Android, operating system data is now always
     encoded/decoded to/from UTF-8, instead of the locale encoding to
     avoid inconsistencies with os.fsencode() and os.fsdecode() which
     are already using UTF-8.

   - bpo-28991(18): functools.lru_cache() was susceptible to an obscure
     reentrancy bug triggerable by a monkey-patched len() function.

   - bpo-28739(19): f-string expressions are no longer accepted as
     docstrings and by ast.literal_eval() even if they do not include
     expressions.

   - bpo-28512(20): Fixed setting the offset attribute of SyntaxError by
     PyErr_SyntaxLocationEx() and PyErr_SyntaxLocationObject().

   - bpo-28918(21): Fix the cross compilation of xxlimited when Python
     has been built with Py_DEBUG defined.

   - bpo-28731(22): Optimize _PyDict_NewPresized() to create correct
     size dict.  Improve speed of dict literal with constant keys up to
     30%.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28893

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29683

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29684

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28598

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29607

   (6) https://bugs.python.org/issue?@action=redirect&bpo=29602

   (7) https://bugs.python.org/issue?@action=redirect&bpo=29347

   (8) https://bugs.python.org/issue?@action=redirect&bpo=29438

   (9) https://bugs.python.org/issue?@action=redirect&bpo=29319

   (10) https://bugs.python.org/issue?@action=redirect&bpo=29337

   (11) https://bugs.python.org/issue?@action=redirect&bpo=29327

   (12) https://bugs.python.org/issue?@action=redirect&bpo=29034

   (13) https://bugs.python.org/issue?@action=redirect&bpo=29159

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28932

   (15) https://bugs.python.org/issue?@action=redirect&bpo=25677

   (16) https://bugs.python.org/issue?@action=redirect&bpo=29000

   (17) https://bugs.python.org/issue?@action=redirect&bpo=26919

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28991

   (19) https://bugs.python.org/issue?@action=redirect&bpo=28739

   (20) https://bugs.python.org/issue?@action=redirect&bpo=28512

   (21) https://bugs.python.org/issue?@action=redirect&bpo=28918

   (22) https://bugs.python.org/issue?@action=redirect&bpo=28731


File: python.info,  Node: Library<179>,  Next: IDLE<51>,  Prev: Core and Builtins<175>,  Up: Python 3 6 1 release candidate 1

1.24.85.2 Library
.................

   - bpo-29169(1): Update zlib to 1.2.11.

   - bpo-29623(2): Allow use of path-like object as a single argument in
     ConfigParser.read().  Patch by David Ellis.

   - bpo-28963(3): Fix out of bound iteration in
     asyncio.Future.remove_done_callback implemented in C.

   - bpo-29704(4): asyncio.subprocess.SubprocessStreamProtocol no longer
     closes before all pipes are closed.

   - bpo-29271(5): Fix Task.current_task and Task.all_tasks implemented
     in C to accept None argument as their pure Python implementation.

   - bpo-29703(6): Fix asyncio to support instantiation of new event
     loops in child processes.

   - bpo-29376(7): Fix assertion error in
     threading._DummyThread.is_alive().

   - bpo-28624(8): Add a test that checks that cwd parameter of Popen()
     accepts PathLike objects.  Patch by Sayan Chowdhury.

   - bpo-28518(9): Start a transaction implicitly before a DML
     statement.  Patch by Aviv Palivoda.

   - bpo-29532(10): Altering a kwarg dictionary passed to
     functools.partial() no longer affects a partial object after
     creation.

   - bpo-29110(11): Fix file object leak in aifc.open() when file is
     given as a filesystem path and is not in valid AIFF format.  Patch
     by Anthony Zhang.

   - bpo-28556(12): Various updates to typing module: typing.Counter,
     typing.ChainMap, improved ABC caching, etc.  Original PRs by Jelle
     Zijlstra, Ivan Levkivskyi, Manuel Krebber, and Łukasz Langa.

   - bpo-29100(13): Fix datetime.fromtimestamp() regression introduced
     in Python 3.6.0: check minimum and maximum years.

   - bpo-29519(14): Fix weakref spewing exceptions during interpreter
     shutdown when used with a rare combination of multiprocessing and
     custom codecs.

   - bpo-29416(15): Prevent infinite loop in pathlib.Path.mkdir

   - bpo-29444(16): Fixed out-of-bounds buffer access in the group()
     method of the match object.  Based on patch by WGH.

   - bpo-29335(17): Fix subprocess.Popen.wait() when the child process
     has exited to a stopped instead of terminated state (ex: when under
     ptrace).

   - bpo-29290(18): Fix a regression in argparse that help messages
     would wrap at non-breaking spaces.

   - bpo-28735(19): Fixed the comparison of mock.MagickMock with
     mock.ANY.

   - bpo-29316(20): Restore the provisional status of typing module, add
     corresponding note to documentation.  Patch by Ivan L.

   - bpo-29219(21): Fixed infinite recursion in the repr of
     uninitialized ctypes.CDLL instances.

   - bpo-29011(22): Fix an important omission by adding Deque to the
     typing module.

   - bpo-28969(23): Fixed race condition in C implementation of
     functools.lru_cache.  KeyError could be raised when cached function
     with full cache was simultaneously called from different threads
     with the same uncached arguments.

   - bpo-29142(24): In urllib.request, suffixes in no_proxy environment
     variable with leading dots could match related hostnames again
     (e.g.  .b.c matches a.b.c).  Patch by Milan Oberkirch.

   - bpo-28961(25): Fix unittest.mock._Call helper: don’t ignore the
     name parameter anymore.  Patch written by Jiajun Huang.

   - bpo-29203(26): functools.lru_cache() now respects PEP 468(27) and
     preserves the order of keyword arguments.  f(a=1, b=2) is now
     cached separately from f(b=2, a=1) since both calls could
     potentially give different results.

   - bpo-15812(28): inspect.getframeinfo() now correctly shows the first
     line of a context.  Patch by Sam Breese.

   - bpo-29094(29): Offsets in a ZIP file created with extern file
     object and modes «w» and «x» now are relative to the start of the
     file.

   - bpo-29085(30): Allow random.Random.seed() to use high quality OS
     randomness rather than the pid and time.

   - bpo-29061(31): Fixed bug in secrets.randbelow() which would hang
     when given a negative input.  Patch by Brendan Donegan.

   - bpo-29079(32): Prevent infinite loop in pathlib.resolve() on
     Windows

   - bpo-13051(33): Fixed recursion errors in large or resized
     curses.textpad.Textbox.  Based on patch by Tycho Andersen.

   - bpo-29119(34): Fix weakrefs in the pure python version of
     collections.OrderedDict move_to_end() method.  Contributed by Andra
     Bogildea.

   - bpo-9770(35): curses.ascii predicates now work correctly with
     negative integers.

   - bpo-28427(36): old keys should not remove new values from
     WeakValueDictionary when collecting from another thread.

   - bpo-28923(37): Remove editor artifacts from Tix.py.

   - bpo-29055(38): Neaten-up empty population error on random.choice()
     by suppressing the upstream exception.

   - bpo-28871(39): Fixed a crash when deallocate deep ElementTree.

   - bpo-19542(40): Fix bugs in WeakValueDictionary.setdefault() and
     WeakValueDictionary.pop() when a GC collection happens in another
     thread.

   - bpo-20191(41): Fixed a crash in resource.prlimit() when passing a
     sequence that doesn’t own its elements as limits.

   - bpo-28779(42): multiprocessing.set_forkserver_preload() would crash
     the forkserver process if a preloaded module instantiated some
     multiprocessing objects such as locks.

   - bpo-28847(43): dbm.dumb now supports reading read-only files and no
     longer writes the index file when it is not changed.

   - bpo-26937(44): The chown() method of the tarfile.TarFile class does
     not fail now when the grp module cannot be imported, as for example
     on Android platforms.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29169

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29623

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28963

   (4) https://bugs.python.org/issue?@action=redirect&bpo=29704

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29271

   (6) https://bugs.python.org/issue?@action=redirect&bpo=29703

   (7) https://bugs.python.org/issue?@action=redirect&bpo=29376

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28624

   (9) https://bugs.python.org/issue?@action=redirect&bpo=28518

   (10) https://bugs.python.org/issue?@action=redirect&bpo=29532

   (11) https://bugs.python.org/issue?@action=redirect&bpo=29110

   (12) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (13) https://bugs.python.org/issue?@action=redirect&bpo=29100

   (14) https://bugs.python.org/issue?@action=redirect&bpo=29519

   (15) https://bugs.python.org/issue?@action=redirect&bpo=29416

   (16) https://bugs.python.org/issue?@action=redirect&bpo=29444

   (17) https://bugs.python.org/issue?@action=redirect&bpo=29335

   (18) https://bugs.python.org/issue?@action=redirect&bpo=29290

   (19) https://bugs.python.org/issue?@action=redirect&bpo=28735

   (20) https://bugs.python.org/issue?@action=redirect&bpo=29316

   (21) https://bugs.python.org/issue?@action=redirect&bpo=29219

   (22) https://bugs.python.org/issue?@action=redirect&bpo=29011

   (23) https://bugs.python.org/issue?@action=redirect&bpo=28969

   (24) https://bugs.python.org/issue?@action=redirect&bpo=29142

   (25) https://bugs.python.org/issue?@action=redirect&bpo=28961

   (26) https://bugs.python.org/issue?@action=redirect&bpo=29203

   (27) https://peps.python.org/pep-0468/

   (28) https://bugs.python.org/issue?@action=redirect&bpo=15812

   (29) https://bugs.python.org/issue?@action=redirect&bpo=29094

   (30) https://bugs.python.org/issue?@action=redirect&bpo=29085

   (31) https://bugs.python.org/issue?@action=redirect&bpo=29061

   (32) https://bugs.python.org/issue?@action=redirect&bpo=29079

   (33) https://bugs.python.org/issue?@action=redirect&bpo=13051

   (34) https://bugs.python.org/issue?@action=redirect&bpo=29119

   (35) https://bugs.python.org/issue?@action=redirect&bpo=9770

   (36) https://bugs.python.org/issue?@action=redirect&bpo=28427

   (37) https://bugs.python.org/issue?@action=redirect&bpo=28923

   (38) https://bugs.python.org/issue?@action=redirect&bpo=29055

   (39) https://bugs.python.org/issue?@action=redirect&bpo=28871

   (40) https://bugs.python.org/issue?@action=redirect&bpo=19542

   (41) https://bugs.python.org/issue?@action=redirect&bpo=20191

   (42) https://bugs.python.org/issue?@action=redirect&bpo=28779

   (43) https://bugs.python.org/issue?@action=redirect&bpo=28847

   (44) https://bugs.python.org/issue?@action=redirect&bpo=26937


File: python.info,  Node: IDLE<51>,  Next: Windows<68>,  Prev: Library<179>,  Up: Python 3 6 1 release candidate 1

1.24.85.3 IDLE
..............

   - bpo-29071(1): IDLE colors f-string prefixes (but not invalid ur
     prefixes).

   - bpo-28572(2): Add 10% to coverage of IDLE’s test_configdialog.
     Update and augment description of the configuration system.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29071

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28572


File: python.info,  Node: Windows<68>,  Next: C API<68>,  Prev: IDLE<51>,  Up: Python 3 6 1 release candidate 1

1.24.85.4 Windows
.................

   - bpo-29579(1): Removes readme.txt from the installer

   - bpo-29326(2): Ignores blank lines in ._pth files (Patch by Alexey
     Izbyshev)

   - bpo-28164(3): Correctly handle special console filenames (patch by
     Eryk Sun)

   - bpo-29409(4): Implement PEP 529(5) for io.FileIO (Patch by Eryk
     Sun)

   - bpo-29392(6): Prevent crash when passing invalid arguments into
     msvcrt module.

   - bpo-25778(7): winreg does not truncate string correctly (Patch by
     Eryk Sun)

   - bpo-28896(8): Deprecate WindowsRegistryFinder and disable it by
     default.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29579

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29326

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28164

   (4) https://bugs.python.org/issue?@action=redirect&bpo=29409

   (5) https://peps.python.org/pep-0529/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=29392

   (7) https://bugs.python.org/issue?@action=redirect&bpo=25778

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28896


File: python.info,  Node: C API<68>,  Next: Documentation<71>,  Prev: Windows<68>,  Up: Python 3 6 1 release candidate 1

1.24.85.5 C API
...............

   - bpo-27867(1): Function PySlice_GetIndicesEx() is replaced with a
     macro if Py_LIMITED_API is not set or set to the value between
     0x03050400 and 0x03060000 (not including) or 0x03060100 or higher.

   - bpo-29083(2): Fixed the declaration of some public API functions.
     PyArg_VaParse() and PyArg_VaParseTupleAndKeywords() were not
     available in limited API. PyArg_ValidateKeywordArguments(),
     PyArg_UnpackTuple() and Py_BuildValue() were not available in
     limited API of version < 3.3 when PY_SSIZE_T_CLEAN is defined.

   - bpo-29058(3): All stable API extensions added after Python 3.2 are
     now available only when Py_LIMITED_API is set to the PY_VERSION_HEX
     value of the minimum Python version supporting this API.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27867

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29083

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29058


File: python.info,  Node: Documentation<71>,  Next: Tests<69>,  Prev: C API<68>,  Up: Python 3 6 1 release candidate 1

1.24.85.6 Documentation
.......................

   - bpo-28929(1): Link the documentation to its source file on GitHub.

   - bpo-25008(2): Document smtpd.py as effectively deprecated and add a
     pointer to aiosmtpd, a third-party asyncio-based replacement.

   - bpo-26355(3): Add canonical header link on each page to
     corresponding major version of the documentation.  Patch by
     Matthias Bussonnier.

   - bpo-29349(4): Fix Python 2 syntax in code for building the
     documentation.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28929

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25008

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26355

   (4) https://bugs.python.org/issue?@action=redirect&bpo=29349


File: python.info,  Node: Tests<69>,  Next: Build<79>,  Prev: Documentation<71>,  Up: Python 3 6 1 release candidate 1

1.24.85.7 Tests
...............

   - bpo-28087(1): Skip test_asyncore and test_eintr poll failures on
     macOS. Skip some tests of select.poll when running on macOS due to
     unresolved issues with the underlying system poll function on some
     macOS versions.

   - bpo-29571(2): to match the behaviour of the ‘re.LOCALE’ flag,
     test_re.test_locale_flag now uses
     ‘locale.getpreferredencoding(False)’ to determine the candidate
     encoding for the test regex (allowing it to correctly skip the test
     when the default locale encoding is a multi-byte encoding)

   - bpo-28950(3): Disallow -j0 to be combined with -T/-l in regrtest
     command line arguments.

   - bpo-28683(4): Fix the tests that bind() a unix socket and raise
     PermissionError on Android for a non-root user.

   - bpo-26939(5): Add the support.setswitchinterval() function to fix
     test_functools hanging on the Android armv7 qemu emulator.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28087

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29571

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28950

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28683

   (5) https://bugs.python.org/issue?@action=redirect&bpo=26939


File: python.info,  Node: Build<79>,  Prev: Tests<69>,  Up: Python 3 6 1 release candidate 1

1.24.85.8 Build
...............

   - bpo-27593(1): sys.version and the platform module python_build(),
     python_branch(), and python_revision() functions now use git
     information rather than hg when building from a repo.

   - bpo-29572(2): Update Windows build and OS X installers to use
     OpenSSL 1.0.2k.

   - bpo-26851(3): Set Android compilation and link flags.

   - bpo-28768(4): Fix implicit declaration of function _setmode.  Patch
     by Masayuki Yamamoto

   - bpo-29080(5): Removes hard dependency on hg.exe from
     PCBuild/build.bat

   - bpo-23903(6): Added missed names to PC/python3.def.

   - bpo-28762(7): lockf() is available on Android API level 24, but the
     F_LOCK macro is not defined in android-ndk-r13.

   - bpo-28538(8): Fix the compilation error that occurs because
     if_nameindex() is available on Android API level 24, but the
     if_nameindex structure is not defined.

   - bpo-20211(9): Do not add the directory for installing C header
     files and the directory for installing object code libraries to the
     cross compilation search paths.  Original patch by Thomas
     Petazzoni.

   - bpo-28849(10): Do not define sys.implementation._multiarch on
     Android.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27593

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29572

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26851

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28768

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29080

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23903

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28762

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28538

   (9) https://bugs.python.org/issue?@action=redirect&bpo=20211

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28849


File: python.info,  Node: Python 3 6 0 final,  Next: Python 3 6 0 release candidate 2,  Prev: Python 3 6 1 release candidate 1,  Up: Changelog

1.24.86 Python 3.6.0 final
--------------------------

'Release date: 2016-12-23'

No changes since release candidate 2


File: python.info,  Node: Python 3 6 0 release candidate 2,  Next: Python 3 6 0 release candidate 1,  Prev: Python 3 6 0 final,  Up: Changelog

1.24.87 Python 3.6.0 release candidate 2
----------------------------------------

'Release date: 2016-12-16'

* Menu:

* Core and Builtins: Core and Builtins<176>.
* Tools/Demos: Tools/Demos<49>.
* Windows: Windows<69>.
* Build: Build<80>.


File: python.info,  Node: Core and Builtins<176>,  Next: Tools/Demos<49>,  Up: Python 3 6 0 release candidate 2

1.24.87.1 Core and Builtins
...........................

   - bpo-28147(1): Fix a memory leak in split-table dictionaries:
     setattr() must not convert combined table into split table.  Patch
     written by INADA Naoki.

   - bpo-28990(2): Fix asyncio SSL hanging if connection is closed
     before handshake is completed.  (Patch by HoHo-Ho)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28147

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28990


File: python.info,  Node: Tools/Demos<49>,  Next: Windows<69>,  Prev: Core and Builtins<176>,  Up: Python 3 6 0 release candidate 2

1.24.87.2 Tools/Demos
.....................

   - bpo-28770(1): Fix python-gdb.py for fastcalls.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28770


File: python.info,  Node: Windows<69>,  Next: Build<80>,  Prev: Tools/Demos<49>,  Up: Python 3 6 0 release candidate 2

1.24.87.3 Windows
.................

   - bpo-28896(1): Deprecate WindowsRegistryFinder.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28896


File: python.info,  Node: Build<80>,  Prev: Windows<69>,  Up: Python 3 6 0 release candidate 2

1.24.87.4 Build
...............

   - bpo-28898(1): Prevent gdb build errors due to HAVE_LONG_LONG
     redefinition.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28898


File: python.info,  Node: Python 3 6 0 release candidate 1,  Next: Python 3 6 0 beta 4,  Prev: Python 3 6 0 release candidate 2,  Up: Changelog

1.24.88 Python 3.6.0 release candidate 1
----------------------------------------

'Release date: 2016-12-06'

* Menu:

* Core and Builtins: Core and Builtins<177>.
* Library: Library<180>.
* C API: C API<69>.
* Documentation: Documentation<72>.
* Tools/Demos: Tools/Demos<50>.


File: python.info,  Node: Core and Builtins<177>,  Next: Library<180>,  Up: Python 3 6 0 release candidate 1

1.24.88.1 Core and Builtins
...........................

   - bpo-23722(1): Rather than silently producing a class that doesn’t
     support zero-argument ‘super()’ in methods, failing to pass the new
     ‘__classcell__’ namespace entry up to ‘type.__new__’ now results in
     a ‘DeprecationWarning’ and a class that supports zero-argument
     ‘super()’.

   - bpo-28797(2): Modifying the class __dict__ inside the __set_name__
     method of a descriptor that is used inside that class no longer
     prevents calling the __set_name__ method of other descriptors.

   - bpo-28782(3): Fix a bug in the implementation ‘yield from’ when
     checking if the next instruction is YIELD_FROM. Regression
     introduced by WORDCODE (bpo-26647(4)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23722

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28797

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28782

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26647


File: python.info,  Node: Library<180>,  Next: C API<69>,  Prev: Core and Builtins<177>,  Up: Python 3 6 0 release candidate 1

1.24.88.2 Library
.................

   - bpo-27030(1): Unknown escapes in re.sub() replacement template are
     allowed again.  But they still are deprecated and will be disabled
     in 3.7.

   - bpo-28835(2): Fix a regression introduced in
     warnings.catch_warnings(): call warnings.showwarning() if it was
     overridden inside the context manager.

   - bpo-27172(3): To assist with upgrades from 2.7, the previously
     documented deprecation of ‘inspect.getfullargspec()’ has been
     reversed.  This decision may be revisited again after the Python
     2.7 branch is no longer officially supported.

   - bpo-26273(4): Add new ‘socket.TCP_CONGESTION’ (Linux 2.6.13) and
     ‘socket.TCP_USER_TIMEOUT’ (Linux 2.6.37) constants.  Patch written
     by Omar Sandoval.

   - bpo-24142(5): Reading a corrupt config file left configparser in an
     invalid state.  Original patch by Florian Höch.

   - bpo-28843(6): Fix asyncio C Task to handle exceptions
     __traceback__.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27030

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28835

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27172

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26273

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24142

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28843


File: python.info,  Node: C API<69>,  Next: Documentation<72>,  Prev: Library<180>,  Up: Python 3 6 0 release candidate 1

1.24.88.3 C API
...............

   - bpo-28808(1): PyUnicode_CompareWithASCIIString() now never raises
     exceptions.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28808


File: python.info,  Node: Documentation<72>,  Next: Tools/Demos<50>,  Prev: C API<69>,  Up: Python 3 6 0 release candidate 1

1.24.88.4 Documentation
.......................

   - bpo-23722(1): The data model reference and the porting section in
     the What’s New guide now cover the additional ‘__classcell__’
     handling needed for custom metaclasses to fully support PEP 487(2)
     and zero-argument ‘super()’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23722

   (2) https://peps.python.org/pep-0487/


File: python.info,  Node: Tools/Demos<50>,  Prev: Documentation<72>,  Up: Python 3 6 0 release candidate 1

1.24.88.5 Tools/Demos
.....................

   - bpo-28023(1): Fix python-gdb.py didn’t support new dict
     implementation.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28023


File: python.info,  Node: Python 3 6 0 beta 4,  Next: Python 3 6 0 beta 3,  Prev: Python 3 6 0 release candidate 1,  Up: Changelog

1.24.89 Python 3.6.0 beta 4
---------------------------

'Release date: 2016-11-21'

* Menu:

* Core and Builtins: Core and Builtins<178>.
* Library: Library<181>.
* Documentation: Documentation<73>.
* Tests: Tests<70>.
* Build: Build<81>.


File: python.info,  Node: Core and Builtins<178>,  Next: Library<181>,  Up: Python 3 6 0 beta 4

1.24.89.1 Core and Builtins
...........................

   - bpo-28532(1): Show sys.version when -V option is supplied twice.

   - bpo-27100(2): The with-statement now checks for __enter__ before it
     checks for __exit__.  This gives less confusing error messages when
     both methods are missing.  Patch by Jonathan Ellington.

   - bpo-28746(3): Fix the set_inheritable() file descriptor method on
     platforms that do not have the ioctl FIOCLEX and FIONCLEX commands.

   - bpo-26920(4): Fix not getting the locale’s charset upon
     initializing the interpreter, on platforms that do not have
     langinfo.

   - bpo-28648(5): Fixed crash in Py_DecodeLocale() in debug build on
     Mac OS X when decode astral characters.  Patch by Xiang Zhang.

   - bpo-19398(6): Extra slash no longer added to sys.path components in
     case of empty compile-time PYTHONPATH components.

   - bpo-28665(7): Improve speed of the STORE_DEREF opcode by 40%.

   - bpo-28583(8): PyDict_SetDefault didn’t combine split table when
     needed.  Patch by Xiang Zhang.

   - bpo-27243(9): Change PendingDeprecationWarning ->
     DeprecationWarning.  As it was agreed in the issue, __aiter__
     returning an awaitable should result in PendingDeprecationWarning
     in 3.5 and in DeprecationWarning in 3.6.

   - bpo-26182(10): Fix a refleak in code that raises
     DeprecationWarning.

   - bpo-28721(11): Fix asynchronous generators aclose() and athrow() to
     handle StopAsyncIteration propagation properly.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28532

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27100

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28746

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26920

   (5) https://bugs.python.org/issue?@action=redirect&bpo=28648

   (6) https://bugs.python.org/issue?@action=redirect&bpo=19398

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28665

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28583

   (9) https://bugs.python.org/issue?@action=redirect&bpo=27243

   (10) https://bugs.python.org/issue?@action=redirect&bpo=26182

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28721


File: python.info,  Node: Library<181>,  Next: Documentation<73>,  Prev: Core and Builtins<178>,  Up: Python 3 6 0 beta 4

1.24.89.2 Library
.................

   - bpo-28752(1): Restored the __reduce__() methods of datetime
     objects.

   - bpo-28727(2): Regular expression patterns, _sre.SRE_Pattern objects
     created by re.compile(), become comparable (only x==y and x!=y
     operators).  This change should fix the bpo-18383(3): don’t
     duplicate warning filters when the warnings module is reloaded
     (thing usually only done in unit tests).

   - bpo-20572(4): The subprocess.Popen.wait method’s undocumented
     endtime parameter now raises a DeprecationWarning.

   - bpo-25659(5): In ctypes, prevent a crash calling the from_buffer()
     and from_buffer_copy() methods on abstract classes like Array.

   - bpo-19717(6): Makes Path.resolve() succeed on paths that do not
     exist.  Patch by Vajrasky Kok

   - bpo-28563(7): Fixed possible DoS and arbitrary code execution when
     handle plural form selections in the gettext module.  The
     expression parser now supports exact syntax supported by GNU
     gettext.

   - bpo-28387(8): Fixed possible crash in _io.TextIOWrapper deallocator
     when the garbage collector is invoked in other thread.  Based on
     patch by Sebastian Cufre.

   - bpo-28600(9): Optimize loop.call_soon.

   - bpo-28613(10): Fix get_event_loop() return the current loop if
     called from coroutines/callbacks.

   - bpo-28634(11): Fix asyncio.isfuture() to support unittest.Mock.

   - bpo-26081(12): Fix refleak in _asyncio.Future.__iter__().throw.

   - bpo-28639(13): Fix inspect.isawaitable to always return bool Patch
     by Justin Mayfield.

   - bpo-28652(14): Make loop methods reject socket kinds they do not
     support.

   - bpo-28653(15): Fix a refleak in functools.lru_cache.

   - bpo-28703(16): Fix asyncio.iscoroutinefunction to handle Mock
     objects.

   - bpo-28704(17): Fix create_unix_server to support Path-like objects
     (PEP 519).

   - bpo-28720(18): Add collections.abc.AsyncGenerator.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28752

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28727

   (3) https://bugs.python.org/issue?@action=redirect&bpo=18383

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20572

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25659

   (6) https://bugs.python.org/issue?@action=redirect&bpo=19717

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28563

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28387

   (9) https://bugs.python.org/issue?@action=redirect&bpo=28600

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28613

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28634

   (12) https://bugs.python.org/issue?@action=redirect&bpo=26081

   (13) https://bugs.python.org/issue?@action=redirect&bpo=28639

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28652

   (15) https://bugs.python.org/issue?@action=redirect&bpo=28653

   (16) https://bugs.python.org/issue?@action=redirect&bpo=28703

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28704

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28720


File: python.info,  Node: Documentation<73>,  Next: Tests<70>,  Prev: Library<181>,  Up: Python 3 6 0 beta 4

1.24.89.3 Documentation
.......................

   - bpo-28513(1): Documented command-line interface of zipfile.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28513


File: python.info,  Node: Tests<70>,  Next: Build<81>,  Prev: Documentation<73>,  Up: Python 3 6 0 beta 4

1.24.89.4 Tests
...............

   - bpo-28666(1): Now test.support.rmtree is able to remove unwritable
     or unreadable directories.

   - bpo-23839(2): Various caches now are cleared before running every
     test file.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28666

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23839


File: python.info,  Node: Build<81>,  Prev: Tests<70>,  Up: Python 3 6 0 beta 4

1.24.89.5 Build
...............

   - bpo-10656(1): Fix out-of-tree building on AIX. Patch by Tristan
     Carel and Michael Haubenwallner.

   - bpo-26359(2): Rename –with-optimiations to –enable-optimizations.

   - bpo-28676(3): Prevent missing “getentropy” declaration warning on
     macOS. Patch by Gareth Rees.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=10656

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26359

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28676


File: python.info,  Node: Python 3 6 0 beta 3,  Next: Python 3 6 0 beta 2,  Prev: Python 3 6 0 beta 4,  Up: Changelog

1.24.90 Python 3.6.0 beta 3
---------------------------

'Release date: 2016-10-31'

* Menu:

* Core and Builtins: Core and Builtins<179>.
* Library: Library<182>.
* Windows: Windows<70>.
* Build: Build<82>.
* Tests: Tests<71>.


File: python.info,  Node: Core and Builtins<179>,  Next: Library<182>,  Up: Python 3 6 0 beta 3

1.24.90.1 Core and Builtins
...........................

   - bpo-28128(1): Deprecation warning for invalid str and byte escape
     sequences now prints better information about where the error
     occurs.  Patch by Serhiy Storchaka and Eric Smith.

   - bpo-28509(2): dict.update() no longer allocate unnecessary large
     memory.

   - bpo-28426(3): Fixed potential crash in PyUnicode_AsDecodedObject()
     in debug build.

   - bpo-28517(4): Fixed of-by-one error in the peephole optimizer that
     caused keeping unreachable code.

   - bpo-28214(5): Improved exception reporting for problematic
     __set_name__ attributes.

   - bpo-23782(6): Fixed possible memory leak in _PyTraceback_Add() and
     exception loss in PyTraceBack_Here().

   - bpo-28471(7): Fix «Python memory allocator called without holding
     the GIL» crash in socket.setblocking.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28128

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28509

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28426

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28517

   (5) https://bugs.python.org/issue?@action=redirect&bpo=28214

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23782

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28471


File: python.info,  Node: Library<182>,  Next: Windows<70>,  Prev: Core and Builtins<179>,  Up: Python 3 6 0 beta 3

1.24.90.2 Library
.................

   - bpo-27517(1): LZMA compressor and decompressor no longer raise
     exceptions if given empty data twice.  Patch by Benjamin Fogle.

   - bpo-28549(2): Fixed segfault in curses’s addch() with ncurses6.

   - bpo-28449(3): tarfile.open() with mode «r» or «r:» now tries to
     open a tar file with compression before trying to open it without
     compression.  Otherwise it had 50% chance failed with
     ignore_zeros=True.

   - bpo-23262(4): The webbrowser module now supports Firefox 36+ and
     derived browsers.  Based on patch by Oleg Broytman.

   - bpo-27939(5): Fixed bugs in tkinter.ttk.LabeledScale and
     tkinter.Scale caused by representing the scale as float value
     internally in Tk.  tkinter.IntVar now works if float value is set
     to underlying Tk variable.

   - bpo-18844(6): The various ways of specifying weights for
     random.choices() now produce the same result sequences.

   - bpo-28255(7): calendar.TextCalendar().prmonth() no longer prints a
     space at the start of new line after printing a month’s calendar.
     Patch by Xiang Zhang.

   - bpo-20491(8): The textwrap.TextWrapper class now honors
     non-breaking spaces.  Based on patch by Kaarle Ritvanen.

   - bpo-28353(9): os.fwalk() no longer fails on broken links.

   - bpo-28430(10): Fix iterator of C implemented asyncio.Future doesn’t
     accept non-None value is passed to it.send(val).

   - bpo-27025(11): Generated names for Tkinter widgets now start by the
     «!» prefix for readability.

   - bpo-25464(12): Fixed HList.header_exists() in tkinter.tix module by
     addin a workaround to Tix library bug.

   - bpo-28488(13): shutil.make_archive() no longer adds entry «./» to
     ZIP archive.

   - bpo-25953(14): re.sub() now raises an error for invalid numerical
     group reference in replacement template even if the pattern is not
     found in the string.  Error message for invalid group reference now
     includes the group index and the position of the reference.  Based
     on patch by SilentGhost.

   - bpo-18219(15): Optimize csv.DictWriter for large number of columns.
     Patch by Mariatta Wijaya.

   - bpo-28448(16): Fix C implemented asyncio.Future didn’t work on
     Windows.

   - bpo-28480(17): Fix error building socket module when multithreading
     is disabled.

   - bpo-24452(18): Make webbrowser support Chrome on Mac OS X.

   - bpo-20766(19): Fix references leaked by pdb in the handling of
     SIGINT handlers.

   - bpo-28492(20): Fix how StopIteration exception is raised in
     _asyncio.Future.

   - bpo-28500(21): Fix asyncio to handle async gens GC from another
     thread.

   - bpo-26923(22): Fix asyncio.Gather to refuse being cancelled once
     all children are done.  Patch by Johannes Ebke.

   - bpo-26796(23): Don’t configure the number of workers for default
     threadpool executor.  Initial patch by Hans Lawrenz.

   - bpo-28544(24): Implement asyncio.Task in C.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27517

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28549

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28449

   (4) https://bugs.python.org/issue?@action=redirect&bpo=23262

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27939

   (6) https://bugs.python.org/issue?@action=redirect&bpo=18844

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28255

   (8) https://bugs.python.org/issue?@action=redirect&bpo=20491

   (9) https://bugs.python.org/issue?@action=redirect&bpo=28353

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28430

   (11) https://bugs.python.org/issue?@action=redirect&bpo=27025

   (12) https://bugs.python.org/issue?@action=redirect&bpo=25464

   (13) https://bugs.python.org/issue?@action=redirect&bpo=28488

   (14) https://bugs.python.org/issue?@action=redirect&bpo=25953

   (15) https://bugs.python.org/issue?@action=redirect&bpo=18219

   (16) https://bugs.python.org/issue?@action=redirect&bpo=28448

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28480

   (18) https://bugs.python.org/issue?@action=redirect&bpo=24452

   (19) https://bugs.python.org/issue?@action=redirect&bpo=20766

   (20) https://bugs.python.org/issue?@action=redirect&bpo=28492

   (21) https://bugs.python.org/issue?@action=redirect&bpo=28500

   (22) https://bugs.python.org/issue?@action=redirect&bpo=26923

   (23) https://bugs.python.org/issue?@action=redirect&bpo=26796

   (24) https://bugs.python.org/issue?@action=redirect&bpo=28544


File: python.info,  Node: Windows<70>,  Next: Build<82>,  Prev: Library<182>,  Up: Python 3 6 0 beta 3

1.24.90.3 Windows
.................

   - bpo-28522(1): Fixes mishandled buffer reallocation in getpathp.c

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28522


File: python.info,  Node: Build<82>,  Next: Tests<71>,  Prev: Windows<70>,  Up: Python 3 6 0 beta 3

1.24.90.4 Build
...............

   - bpo-28444(1): Fix missing extensions modules when cross compiling.

   - bpo-28208(2): Update Windows build and OS X installers to use
     SQLite 3.14.2.

   - bpo-28248(3): Update Windows build and OS X installers to use
     OpenSSL 1.0.2j.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28444

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28208

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28248


File: python.info,  Node: Tests<71>,  Prev: Build<82>,  Up: Python 3 6 0 beta 3

1.24.90.5 Tests
...............

   - bpo-26944(1): Fix test_posix for Android where “id -G” is entirely
     wrong or missing the effective gid.

   - bpo-28409(2): regrtest: fix the parser of command line arguments.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26944

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28409


File: python.info,  Node: Python 3 6 0 beta 2,  Next: Python 3 6 0 beta 1,  Prev: Python 3 6 0 beta 3,  Up: Changelog

1.24.91 Python 3.6.0 beta 2
---------------------------

'Release date: 2016-10-10'

* Menu:

* Core and Builtins: Core and Builtins<180>.
* Library: Library<183>.
* Windows: Windows<71>.
* C API: C API<70>.
* Build: Build<83>.
* Tests: Tests<72>.


File: python.info,  Node: Core and Builtins<180>,  Next: Library<183>,  Up: Python 3 6 0 beta 2

1.24.91.1 Core and Builtins
...........................

   - bpo-28183(1): Optimize and cleanup dict iteration.

   - bpo-26081(2): Added C implementation of asyncio.Future.  Original
     patch by Yury Selivanov.

   - bpo-28379(3): Added sanity checks and tests for
     PyUnicode_CopyCharacters().  Patch by Xiang Zhang.

   - bpo-28376(4): The type of long range iterator is now registered as
     Iterator.  Patch by Oren Milman.

   - bpo-28376(5): Creating instances of range_iterator by calling
     range_iterator type now is deprecated.  Patch by Oren Milman.

   - bpo-28376(6): The constructor of range_iterator now checks that
     step is not 0.  Patch by Oren Milman.

   - bpo-26906(7): Resolving special methods of uninitialized type now
     causes implicit initialization of the type instead of a fail.

   - bpo-18287(8): PyType_Ready() now checks that tp_name is not NULL.
     Original patch by Niklas Koep.

   - bpo-24098(9): Fixed possible crash when AST is changed in process
     of compiling it.

   - bpo-28201(10): Dict reduces possibility of 2nd conflict in hash
     table when hashes have same lower bits.

   - bpo-28350(11): String constants with null character no longer
     interned.

   - bpo-26617(12): Fix crash when GC runs during weakref callbacks.

   - bpo-27942(13): String constants now interned recursively in tuples
     and frozensets.

   - bpo-21578(14): Fixed misleading error message when ImportError
     called with invalid keyword args.

   - bpo-28203(15): Fix incorrect type in complex(1.0, {2:3}) error
     message.  Patch by Soumya Sharma.

   - bpo-28086(16): Single var-positional argument of tuple subtype was
     passed unscathed to the C-defined function.  Now it is converted to
     exact tuple.

   - bpo-28214(17): Now __set_name__ is looked up on the class instead
     of the instance.

   - bpo-27955(18): Fallback on reading /dev/urandom device when the
     getrandom() syscall fails with EPERM, for example when blocked by
     SECCOMP.

   - bpo-28192(19): Don’t import readline in isolated mode.

   - Upgrade internal unicode databases to Unicode version 9.0.0.

   - bpo-28131(20): Fix a regression in zipimport’s compile_source().
     zipimport should use the same optimization level as the
     interpreter.

   - bpo-28126(21): Replace Py_MEMCPY with memcpy().  Visual Studio can
     properly optimize memcpy().

   - bpo-28120(22): Fix dict.pop() for split dictionary when trying to
     remove a «pending key» (Not yet inserted in split-table).  Patch by
     Xiang Zhang.

   - bpo-26182(23): Raise DeprecationWarning when async and await
     keywords are used as variable/attribute/class/function name.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28183

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26081

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28379

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28376

   (5) https://bugs.python.org/issue?@action=redirect&bpo=28376

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28376

   (7) https://bugs.python.org/issue?@action=redirect&bpo=26906

   (8) https://bugs.python.org/issue?@action=redirect&bpo=18287

   (9) https://bugs.python.org/issue?@action=redirect&bpo=24098

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28201

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28350

   (12) https://bugs.python.org/issue?@action=redirect&bpo=26617

   (13) https://bugs.python.org/issue?@action=redirect&bpo=27942

   (14) https://bugs.python.org/issue?@action=redirect&bpo=21578

   (15) https://bugs.python.org/issue?@action=redirect&bpo=28203

   (16) https://bugs.python.org/issue?@action=redirect&bpo=28086

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28214

   (18) https://bugs.python.org/issue?@action=redirect&bpo=27955

   (19) https://bugs.python.org/issue?@action=redirect&bpo=28192

   (20) https://bugs.python.org/issue?@action=redirect&bpo=28131

   (21) https://bugs.python.org/issue?@action=redirect&bpo=28126

   (22) https://bugs.python.org/issue?@action=redirect&bpo=28120

   (23) https://bugs.python.org/issue?@action=redirect&bpo=26182


File: python.info,  Node: Library<183>,  Next: Windows<71>,  Prev: Core and Builtins<180>,  Up: Python 3 6 0 beta 2

1.24.91.2 Library
.................

   - bpo-27998(1): Fixed bytes path support in os.scandir() on Windows.
     Patch by Eryk Sun.

   - bpo-28317(2): The disassembler now decodes FORMAT_VALUE argument.

   - bpo-26293(3): Fixed writing ZIP files that starts not from the
     start of the file.  Offsets in ZIP file now are relative to the
     start of the archive in conforming to the specification.

   - bpo-28380(4): unittest.mock Mock autospec functions now properly
     support assert_called, assert_not_called, and assert_called_once.

   - bpo-27181(5): remove statistics.geometric_mean and defer until 3.7.

   - bpo-28229(6): lzma module now supports pathlib.

   - bpo-28321(7): Fixed writing non-BMP characters with binary format
     in plistlib.

   - bpo-28225(8): bz2 module now supports pathlib.  Initial patch by
     Ethan Furman.

   - bpo-28227(9): gzip now supports pathlib.  Patch by Ethan Furman.

   - bpo-27358(10): Optimized merging var-keyword arguments and improved
     error message when passing a non-mapping as a var-keyword argument.

   - bpo-28257(11): Improved error message when passing a non-iterable
     as a var-positional argument.  Added opcode
     BUILD_TUPLE_UNPACK_WITH_CALL.

   - bpo-28322(12): Fixed possible crashes when unpickle itertools
     objects from incorrect pickle data.  Based on patch by John Leitch.

   - bpo-28228(13): imghdr now supports pathlib.

   - bpo-28226(14): compileall now supports pathlib.

   - bpo-28314(15): Fix function declaration (C flags) for the
     getiterator() method of xml.etree.ElementTree.Element.

   - bpo-28148(16): Stop using localtime() and gmtime() in the time
     module.  Introduced platform independent _PyTime_localtime API that
     is similar to POSIX localtime_r, but available on all platforms.
     Patch by Ed Schouten.

   - bpo-28253(17): Fixed calendar functions for extreme months: 0001-01
     and 9999-12.  Methods itermonthdays() and itermonthdays2() are
     reimplemented so that they don’t call itermonthdates() which can
     cause datetime.date under/overflow.

   - bpo-28275(18): Fixed possible use after free in the decompress()
     methods of the LZMADecompressor and BZ2Decompressor classes.
     Original patch by John Leitch.

   - bpo-27897(19): Fixed possible crash in
     sqlite3.Connection.create_collation() if pass invalid string-like
     object as a name.  Patch by Xiang Zhang.

   - bpo-18844(20): random.choices() now has k as a keyword-only
     argument to improve the readability of common cases and come into
     line with the signature used in other languages.

   - bpo-18893(21): Fix invalid exception handling in
     Lib/ctypes/macholib/dyld.py.  Patch by Madison May.

   - bpo-27611(22): Fixed support of default root window in the
     tkinter.tix module.  Added the master parameter in the DisplayStyle
     constructor.

   - bpo-27348(23): In the traceback module, restore the formatting of
     exception messages like «Exception: None».  This fixes a regression
     introduced in 3.5a2.

   - bpo-25651(24): Allow false values to be used for msg parameter of
     subTest().

   - bpo-27778(25): Fix a memory leak in os.getrandom() when the
     getrandom() is interrupted by a signal and a signal handler raises
     a Python exception.

   - bpo-28200(26): Fix memory leak on Windows in the os module (fix
     path_converter() function).

   - bpo-25400(27): RobotFileParser now correctly returns default values
     for crawl_delay and request_rate.  Initial patch by Peter Wirtz.

   - bpo-27932(28): Prevent memory leak in win32_ver().

   - Fix UnboundLocalError in socket._sendfile_use_sendfile.

   - bpo-28075(29): Check for ERROR_ACCESS_DENIED in Windows
     implementation of os.stat().  Patch by Eryk Sun.

   - bpo-22493(30): Warning message emitted by using inline flags in the
     middle of regular expression now contains a (truncated) regex
     pattern.  Patch by Tim Graham.

   - bpo-25270(31): Prevent codecs.escape_encode() from raising
     SystemError when an empty bytestring is passed.

   - bpo-28181(32): Get antigravity over HTTPS. Patch by Kaartic
     Sivaraam.

   - bpo-25895(33): Enable WebSocket URL schemes in
     urllib.parse.urljoin.  Patch by Gergely Imreh and Markus
     Holtermann.

   - bpo-28114(34): Fix a crash in parse_envlist() when env contains
     byte strings.  Patch by Eryk Sun.

   - bpo-27599(35): Fixed buffer overrun in binascii.b2a_qp() and
     binascii.a2b_qp().

   - bpo-27906(36): Fix socket accept exhaustion during high TCP
     traffic.  Patch by Kevin Conway.

   - bpo-28174(37): Handle when SO_REUSEPORT isn’t properly supported.
     Patch by Seth Michael Larson.

   - bpo-26654(38): Inspect functools.partial in
     asyncio.Handle.__repr__.  Patch by iceboy.

   - bpo-26909(39): Fix slow pipes IO in asyncio.  Patch by INADA Naoki.

   - bpo-28176(40): Fix callbacks race in
     asyncio.SelectorLoop.sock_connect.

   - bpo-27759(41): Fix selectors incorrectly retain invalid file
     descriptors.  Patch by Mark Williams.

   - bpo-28368(42): Refuse monitoring processes if the child watcher has
     no loop attached.  Patch by Vincent Michel.

   - bpo-28369(43): Raise RuntimeError when transport’s FD is used with
     add_reader, add_writer, etc.

   - bpo-28370(44): Speedup asyncio.StreamReader.readexactly.  Patch by
     Коренберг Марк.

   - bpo-28371(45): Deprecate passing asyncio.Handles to
     run_in_executor.

   - bpo-28372(46): Fix asyncio to support formatting of non-python
     coroutines.

   - bpo-28399(47): Remove UNIX socket from FS before binding.  Patch by
     Коренберг Марк.

   - bpo-27972(48): Prohibit Tasks to await on themselves.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27998

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28317

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26293

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28380

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27181

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28229

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28321

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28225

   (9) https://bugs.python.org/issue?@action=redirect&bpo=28227

   (10) https://bugs.python.org/issue?@action=redirect&bpo=27358

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28257

   (12) https://bugs.python.org/issue?@action=redirect&bpo=28322

   (13) https://bugs.python.org/issue?@action=redirect&bpo=28228

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28226

   (15) https://bugs.python.org/issue?@action=redirect&bpo=28314

   (16) https://bugs.python.org/issue?@action=redirect&bpo=28148

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28253

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28275

   (19) https://bugs.python.org/issue?@action=redirect&bpo=27897

   (20) https://bugs.python.org/issue?@action=redirect&bpo=18844

   (21) https://bugs.python.org/issue?@action=redirect&bpo=18893

   (22) https://bugs.python.org/issue?@action=redirect&bpo=27611

   (23) https://bugs.python.org/issue?@action=redirect&bpo=27348

   (24) https://bugs.python.org/issue?@action=redirect&bpo=25651

   (25) https://bugs.python.org/issue?@action=redirect&bpo=27778

   (26) https://bugs.python.org/issue?@action=redirect&bpo=28200

   (27) https://bugs.python.org/issue?@action=redirect&bpo=25400

   (28) https://bugs.python.org/issue?@action=redirect&bpo=27932

   (29) https://bugs.python.org/issue?@action=redirect&bpo=28075

   (30) https://bugs.python.org/issue?@action=redirect&bpo=22493

   (31) https://bugs.python.org/issue?@action=redirect&bpo=25270

   (32) https://bugs.python.org/issue?@action=redirect&bpo=28181

   (33) https://bugs.python.org/issue?@action=redirect&bpo=25895

   (34) https://bugs.python.org/issue?@action=redirect&bpo=28114

   (35) https://bugs.python.org/issue?@action=redirect&bpo=27599

   (36) https://bugs.python.org/issue?@action=redirect&bpo=27906

   (37) https://bugs.python.org/issue?@action=redirect&bpo=28174

   (38) https://bugs.python.org/issue?@action=redirect&bpo=26654

   (39) https://bugs.python.org/issue?@action=redirect&bpo=26909

   (40) https://bugs.python.org/issue?@action=redirect&bpo=28176

   (41) https://bugs.python.org/issue?@action=redirect&bpo=27759

   (42) https://bugs.python.org/issue?@action=redirect&bpo=28368

   (43) https://bugs.python.org/issue?@action=redirect&bpo=28369

   (44) https://bugs.python.org/issue?@action=redirect&bpo=28370

   (45) https://bugs.python.org/issue?@action=redirect&bpo=28371

   (46) https://bugs.python.org/issue?@action=redirect&bpo=28372

   (47) https://bugs.python.org/issue?@action=redirect&bpo=28399

   (48) https://bugs.python.org/issue?@action=redirect&bpo=27972


File: python.info,  Node: Windows<71>,  Next: C API<70>,  Prev: Library<183>,  Up: Python 3 6 0 beta 2

1.24.91.3 Windows
.................

   - bpo-28402(1): Adds signed catalog files for stdlib on Windows.

   - bpo-28333(2): Enables Unicode for ps1/ps2 and input() prompts.
     (Patch by Eryk Sun)

   - bpo-28251(3): Improvements to help manuals on Windows.

   - bpo-28110(4): launcher.msi has different product codes between
     32-bit and 64-bit

   - bpo-28161(5): Opening CON for write access fails

   - bpo-28162(6): WindowsConsoleIO readall() fails if first line starts
     with Ctrl+Z

   - bpo-28163(7): WindowsConsoleIO fileno() passes wrong flags to
     _open_osfhandle

   - bpo-28164(8): _PyIO_get_console_type fails for various paths

   - bpo-28137(9): Renames Windows path file to ._pth

   - bpo-28138(10): Windows ._pth file should allow import site

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28402

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28333

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28251

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28110

   (5) https://bugs.python.org/issue?@action=redirect&bpo=28161

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28162

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28163

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28164

   (9) https://bugs.python.org/issue?@action=redirect&bpo=28137

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28138


File: python.info,  Node: C API<70>,  Next: Build<83>,  Prev: Windows<71>,  Up: Python 3 6 0 beta 2

1.24.91.4 C API
...............

   - bpo-28426(1): Deprecated undocumented functions
     PyUnicode_AsEncodedObject(), PyUnicode_AsDecodedObject(),
     PyUnicode_AsDecodedUnicode() and PyUnicode_AsEncodedUnicode().

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28426


File: python.info,  Node: Build<83>,  Next: Tests<72>,  Prev: C API<70>,  Up: Python 3 6 0 beta 2

1.24.91.5 Build
...............

   - bpo-28258(1): Fixed build with Estonian locale (python-config and
     distclean targets in Makefile).  Patch by Arfrever Frehtes
     Taifersar Arahesis.

   - bpo-26661(2): setup.py now detects system libffi with multiarch
     wrapper.

   - bpo-15819(3): Remove redundant include search directory option for
     building outside the source tree.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28258

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26661

   (3) https://bugs.python.org/issue?@action=redirect&bpo=15819


File: python.info,  Node: Tests<72>,  Prev: Build<83>,  Up: Python 3 6 0 beta 2

1.24.91.6 Tests
...............

   - bpo-28217(1): Adds _testconsole module to test console input.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28217


File: python.info,  Node: Python 3 6 0 beta 1,  Next: Python 3 6 0 alpha 4,  Prev: Python 3 6 0 beta 2,  Up: Changelog

1.24.92 Python 3.6.0 beta 1
---------------------------

'Release date: 2016-09-12'

* Menu:

* Core and Builtins: Core and Builtins<181>.
* Library: Library<184>.
* IDLE: IDLE<52>.
* C API: C API<71>.
* Tests: Tests<73>.
* Build: Build<84>.
* Tools/Demos: Tools/Demos<51>.
* Windows: Windows<72>.


File: python.info,  Node: Core and Builtins<181>,  Next: Library<184>,  Up: Python 3 6 0 beta 1

1.24.92.1 Core and Builtins
...........................

   - bpo-23722(1): The __class__ cell used by zero-argument super() is
     now initialized from type.__new__ rather than __build_class__, so
     class methods relying on that will now work correctly when called
     from metaclass methods during class creation.  Patch by Martin
     Teichmann.

   - bpo-25221(2): Fix corrupted result from PyLong_FromLong(0) when
     Python is compiled with NSMALLPOSINTS = 0.

   - bpo-27080(3): Implement formatting support for PEP 515(4).  Initial
     patch by Chris Angelico.

   - bpo-27199(5): In tarfile, expose copyfileobj bufsize to improve
     throughput.  Patch by Jason Fried.

   - bpo-27948(6): In f-strings, only allow backslashes inside the
     braces (where the expressions are).  This is a breaking change from
     the 3.6 alpha releases, where backslashes are allowed anywhere in
     an f-string.  Also, require that expressions inside f-strings be
     enclosed within literal braces, and not escapes like
     ‘f'\x7b"hi"\x7d'’.

   - bpo-28046(7): Remove platform-specific directories from sys.path.

   - bpo-28071(8): Add early-out for differencing from an empty set.

   - bpo-25758(9): Prevents zipimport from unnecessarily encoding a
     filename (patch by Eryk Sun)

   - bpo-25856(10): The __module__ attribute of extension classes and
     functions now is interned.  This leads to more compact pickle data
     with protocol 4.

   - bpo-27213(11): Rework CALL_FUNCTION* opcodes to produce shorter and
     more efficient bytecode.  Patch by Demur Rumed, design by Serhiy
     Storchaka, reviewed by Serhiy Storchaka and Victor Stinner.

   - bpo-26331(12): Implement tokenizing support for PEP 515(13).  Patch
     by Georg Brandl.

   - bpo-27999(14): Make «global after use» a SyntaxError, and ditto for
     nonlocal.  Patch by Ivan Levkivskyi.

   - bpo-28003(15): Implement PEP 525(16) – Asynchronous Generators.

   - bpo-27985(17): Implement PEP 526(18) – Syntax for Variable
     Annotations.  Patch by Ivan Levkivskyi.

   - bpo-26058(19): Add a new private version to the builtin dict type,
     incremented at each dictionary creation and at each dictionary
     change.  Implementation of the PEP 509.

   - bpo-27364(20): A backslash-character pair that is not a valid
     escape sequence now generates a DeprecationWarning.  Patch by
     Emanuel Barry.

   - bpo-27350(21): ‘dict’ implementation is changed like PyPy.  It is
     more compact and preserves insertion order.  (Concept developed by
     Raymond Hettinger and patch by Inada Naoki.)

   - bpo-27911(22): Remove unnecessary error checks in
     ‘exec_builtin_or_dynamic()’.

   - bpo-27078(23): Added BUILD_STRING opcode.  Optimized f-strings
     evaluation.

   - bpo-17884(24): Python now requires systems with inttypes.h and
     stdint.h

   - bpo-27961(25): Require platforms to support ‘long long’.  Python
     hasn’t compiled without ‘long long’ for years, so this is basically
     a formality.

   - bpo-27355(26): Removed support for Windows CE. It was never
     finished, and Windows CE is no longer a relevant platform for
     Python.

   - Implement PEP 523(27).

   - bpo-27870(28): A left shift of zero by a large integer no longer
     attempts to allocate large amounts of memory.

   - bpo-25402(29): In int-to-decimal-string conversion, improve the
     estimate of the intermediate memory required, and remove an
     unnecessarily strict overflow check.  Patch by Serhiy Storchaka.

   - bpo-27214(30): In long_invert, be more careful about modifying
     object returned by long_add, and remove an unnecessary check for
     small longs.  Thanks Oren Milman for analysis and patch.

   - bpo-27506(31): Support passing the bytes/bytearray.translate()
     «delete» argument by keyword.

   - bpo-27812(32): Properly clear out a generator’s frame’s
     backreference to the generator to prevent crashes in frame.clear().

   - bpo-27811(33): Fix a crash when a coroutine that has not been
     awaited is finalized with warnings-as-errors enabled.

   - bpo-27587(34): Fix another issue found by PVS-Studio: Null pointer
     check after use of “def” in _PyState_AddModule().  Initial patch by
     Christian Heimes.

   - bpo-27792(35): The modulo operation applied to ‘bool’ and other
     ‘int’ subclasses now always returns an ‘int’.  Previously the
     return type depended on the input values.  Patch by Xiang Zhang.

   - bpo-26984(36): int() now always returns an instance of exact int.

   - bpo-25604(37): Fix a minor bug in integer true division; this bug
     could potentially have caused off-by-one-ulp results on platforms
     with unreliable ldexp implementations.

   - bpo-24254(38): Make class definition namespace ordered by default.

   - bpo-27662(39): Fix an overflow check in ‘List_New’: the original
     code was checking against ‘Py_SIZE_MAX’ instead of the correct
     upper bound of ‘Py_SSIZE_T_MAX’.  Patch by Xiang Zhang.

   - bpo-27782(40): Multi-phase extension module import now correctly
     allows the ‘m_methods’ field to be used to add module level
     functions to instances of non-module types returned from
     ‘Py_create_mod’.  Patch by Xiang Zhang.

   - bpo-27936(41): The round() function accepted a second None argument
     for some types but not for others.  Fixed the inconsistency by
     accepting None for all numeric types.

   - bpo-27487(42): Warn if a submodule argument to «python -m» or
     runpy.run_module() is found in sys.modules after parent packages
     are imported, but before the submodule is executed.

   - bpo-27157(43): Make only type() itself accept the one-argument
     form.  Patch by Eryk Sun and Emanuel Barry.

   - bpo-27558(44): Fix a SystemError in the implementation of «raise»
     statement.  In a brand new thread, raise a RuntimeError since there
     is no active exception to reraise.  Patch written by Xiang Zhang.

   - bpo-28008(45): Implement PEP 530(46) – asynchronous comprehensions.

   - bpo-27942(47): Fix memory leak in codeobject.c

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23722

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25221

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27080

   (4) https://peps.python.org/pep-0515/

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27199

   (6) https://bugs.python.org/issue?@action=redirect&bpo=27948

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28046

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28071

   (9) https://bugs.python.org/issue?@action=redirect&bpo=25758

   (10) https://bugs.python.org/issue?@action=redirect&bpo=25856

   (11) https://bugs.python.org/issue?@action=redirect&bpo=27213

   (12) https://bugs.python.org/issue?@action=redirect&bpo=26331

   (13) https://peps.python.org/pep-0515/

   (14) https://bugs.python.org/issue?@action=redirect&bpo=27999

   (15) https://bugs.python.org/issue?@action=redirect&bpo=28003

   (16) https://peps.python.org/pep-0525/

   (17) https://bugs.python.org/issue?@action=redirect&bpo=27985

   (18) https://peps.python.org/pep-0526/

   (19) https://bugs.python.org/issue?@action=redirect&bpo=26058

   (20) https://bugs.python.org/issue?@action=redirect&bpo=27364

   (21) https://bugs.python.org/issue?@action=redirect&bpo=27350

   (22) https://bugs.python.org/issue?@action=redirect&bpo=27911

   (23) https://bugs.python.org/issue?@action=redirect&bpo=27078

   (24) https://bugs.python.org/issue?@action=redirect&bpo=17884

   (25) https://bugs.python.org/issue?@action=redirect&bpo=27961

   (26) https://bugs.python.org/issue?@action=redirect&bpo=27355

   (27) https://peps.python.org/pep-0523/

   (28) https://bugs.python.org/issue?@action=redirect&bpo=27870

   (29) https://bugs.python.org/issue?@action=redirect&bpo=25402

   (30) https://bugs.python.org/issue?@action=redirect&bpo=27214

   (31) https://bugs.python.org/issue?@action=redirect&bpo=27506

   (32) https://bugs.python.org/issue?@action=redirect&bpo=27812

   (33) https://bugs.python.org/issue?@action=redirect&bpo=27811

   (34) https://bugs.python.org/issue?@action=redirect&bpo=27587

   (35) https://bugs.python.org/issue?@action=redirect&bpo=27792

   (36) https://bugs.python.org/issue?@action=redirect&bpo=26984

   (37) https://bugs.python.org/issue?@action=redirect&bpo=25604

   (38) https://bugs.python.org/issue?@action=redirect&bpo=24254

   (39) https://bugs.python.org/issue?@action=redirect&bpo=27662

   (40) https://bugs.python.org/issue?@action=redirect&bpo=27782

   (41) https://bugs.python.org/issue?@action=redirect&bpo=27936

   (42) https://bugs.python.org/issue?@action=redirect&bpo=27487

   (43) https://bugs.python.org/issue?@action=redirect&bpo=27157

   (44) https://bugs.python.org/issue?@action=redirect&bpo=27558

   (45) https://bugs.python.org/issue?@action=redirect&bpo=28008

   (46) https://peps.python.org/pep-0530/

   (47) https://bugs.python.org/issue?@action=redirect&bpo=27942


File: python.info,  Node: Library<184>,  Next: IDLE<52>,  Prev: Core and Builtins<181>,  Up: Python 3 6 0 beta 1

1.24.92.2 Library
.................

   - bpo-28732(1): Fix crash in os.spawnv() with no elements in args

   - bpo-28485(2): Always raise ValueError for negative
     compileall.compile_dir(workers=…) parameter, even when
     multithreading is unavailable.

   - bpo-28037(3): Use sqlite3_get_autocommit() instead of setting
     Connection->inTransaction manually.

   - bpo-25283(4): Attributes tm_gmtoff and tm_zone are now available on
     all platforms in the return values of time.localtime() and
     time.gmtime().

   - bpo-24454(5): Regular expression match object groups are now
     accessible using __getitem__.  «mo[x]» is equivalent to
     «mo.group(x)».

   - bpo-10740(6): sqlite3 no longer implicitly commit an open
     transaction before DDL statements.

   - bpo-17941(7): Add a 'module' parameter to collections.namedtuple().

   - bpo-22493(8): Inline flags now should be used only at the start of
     the regular expression.  Deprecation warning is emitted if uses
     them in the middle of the regular expression.

   - bpo-26885(9): xmlrpc now supports unmarshalling additional data
     types used by Apache XML-RPC implementation for numerics and None.

   - bpo-28070(10): Fixed parsing inline verbose flag in regular
     expressions.

   - bpo-19500(11): Add client-side SSL session resumption to the ssl
     module.

   - bpo-28022(12): Deprecate ssl-related arguments in favor of
     SSLContext.  The deprecation include manual creation of SSLSocket
     and certfile/keyfile (or similar) in ftplib, httplib, imaplib,
     smtplib, poplib and urllib.

   - bpo-28043(13): SSLContext has improved default settings:
     OP_NO_SSLv2, OP_NO_SSLv3, OP_NO_COMPRESSION,
     OP_CIPHER_SERVER_PREFERENCE, OP_SINGLE_DH_USE, OP_SINGLE_ECDH_USE
     and HIGH ciphers without MD5.

   - bpo-24693(14): Changed some RuntimeError’s in the zipfile module to
     more appropriate types.  Improved some error messages and debugging
     output.

   - bpo-17909(15): ‘json.load’ and ‘json.loads’ now support binary
     input encoded as UTF-8, UTF-16 or UTF-32.  Patch by Serhiy
     Storchaka.

   - bpo-27137(16): the pure Python fallback implementation of
     ‘functools.partial’ now matches the behaviour of its accelerated C
     counterpart for subclassing, pickling and text representation
     purposes.  Patch by Emanuel Barry and Serhiy Storchaka.

   - Fix possible integer overflows and crashes in the mmap module with
     unusual usage patterns.

   - bpo-1703178(17): Fix the ability to pass the –link-objects option
     to the distutils build_ext command.

   - bpo-28019(18): itertools.count() no longer rounds non-integer step
     in range between 1.0 and 2.0 to 1.

   - bpo-18401(19): Pdb now supports the “readrc” keyword argument to
     control whether .pdbrc files should be read.  Patch by Martin
     Matusiak and Sam Kimbrel.

   - bpo-25969(20): Update the lib2to3 grammar to handle the unpacking
     generalizations added in 3.5.

   - bpo-14977(21): mailcap now respects the order of the lines in the
     mailcap files («first match»), as required by RFC 1542.  Patch by
     Michael Lazar.

   - bpo-28082(22): Convert re flag constants to IntFlag.

   - bpo-28025(23): Convert all ssl module constants to IntEnum and
     IntFlags.  SSLContext properties now return flags and enums.

   - bpo-23591(24): Add Flag, IntFlag, and auto() to enum module.

   - bpo-433028(25): Added support of modifier spans in regular
     expressions.

   - bpo-24594(26): Validates persist parameter when opening MSI
     database

   - bpo-17582(27): xml.etree.ElementTree nows preserves whitespaces in
     attributes (Patch by Duane Griffin.  Reviewed and approved by
     Stefan Behnel.)

   - bpo-28047(28): Fixed calculation of line length used for the base64
     CTE in the new email policies.

   - bpo-27576(29): Fix call order in OrderedDict.__init__().

   - email.generator.DecodedGenerator now supports the policy keyword.

   - bpo-28027(30): Remove undocumented modules from ‘Lib/plat-*’: IN,
     CDROM, DLFCN, TYPES, CDIO, and STROPTS.

   - bpo-27445(31): Don’t pass str(_charset) to MIMEText.set_payload().
     Patch by Claude Paroz.

   - bpo-24277(32): The new email API is no longer provisional, and the
     docs have been reorganized and rewritten to emphasize the new API.

   - bpo-22450(33): urllib now includes an ‘Accept: */*’ header among
     the default headers.  This makes the results of REST API requests
     more consistent and predictable especially when proxy servers are
     involved.

   - lib2to3.pgen3.driver.load_grammar() now creates a stable cache file
     between runs given the same Grammar.txt input regardless of the
     hash randomization setting.

   - bpo-28005(34): Allow ImportErrors in encoding implementation to
     propagate.

   - bpo-26667(35): Support path-like objects in importlib.util.

   - bpo-27570(36): Avoid zero-length memcpy() etc calls with null
     source pointers in the «ctypes» and «array» modules.

   - bpo-22233(37): Break email header lines 'only' on the RFC specified
     CR and LF characters, not on arbitrary unicode line breaks.  This
     also fixes a bug in HTTP header parsing.

   - bpo-27331(38): The email.mime classes now all accept an optional
     policy keyword.

   - bpo-27988(39): Fix email iter_attachments incorrect mutation of
     payload list.

   - bpo-16113(40): Add SHA-3 and SHAKE support to hashlib module.

   - Eliminate a tautological-pointer-compare warning in _scproxy.c.

   - bpo-27776(41): The *note os.urandom(): 747. function does now block
     on Linux 3.17 and newer until the system urandom entropy pool is
     initialized to increase the security.  This change is part of the
     PEP 524(42).

   - bpo-27778(43): Expose the Linux ‘getrandom()’ syscall as a new
     *note os.getrandom(): ebb. function.  This change is part of the
     PEP 524(44).

   - bpo-27691(45): Fix ssl module’s parsing of GEN_RID subject
     alternative name fields in X.509 certs.

   - bpo-18844(46): Add random.choices().

   - bpo-25761(47): Improved error reporting about truncated pickle data
     in C implementation of unpickler.  UnpicklingError is now raised
     instead of AttributeError and ValueError in some cases.

   - bpo-26798(48): Add BLAKE2 (blake2b and blake2s) to hashlib.

   - bpo-26032(49): Optimized globbing in pathlib by using os.scandir();
     it is now about 1.5–4 times faster.

   - bpo-25596(50): Optimized glob() and iglob() functions in the glob
     module; they are now about 3–6 times faster.

   - bpo-27928(51): Add scrypt (password-based key derivation function)
     to hashlib module (requires OpenSSL 1.1.0).

   - bpo-27850(52): Remove 3DES from ssl module’s default cipher list to
     counter measure sweet32 attack ( CVE 2016-2183(53)).

   - bpo-27766(54): Add ChaCha20 Poly1305 to ssl module’s default cipher
     list.  (Required OpenSSL 1.1.0 or LibreSSL).

   - bpo-25387(55): Check return value of winsound.MessageBeep.

   - bpo-27866(56): Add SSLContext.get_ciphers() method to get a list of
     all enabled ciphers.

   - bpo-27744(57): Add AF_ALG (Linux Kernel crypto) to socket module.

   - bpo-26470(58): Port ssl and hashlib module to OpenSSL 1.1.0.

   - bpo-11620(59): Fix support for SND_MEMORY in winsound.PlaySound.
     Based on a patch by Tim Lesher.

   - bpo-11734(60): Add support for IEEE 754 half-precision floats to
     the struct module.  Based on a patch by Eli Stevens.

   - bpo-27919(61): Deprecated ‘extra_path’ distribution option in
     distutils packaging.

   - bpo-23229(62): Add new ‘cmath’ constants: ‘cmath.inf’ and
     ‘cmath.nan’ to match ‘math.inf’ and ‘math.nan’, and also
     ‘cmath.infj’ and ‘cmath.nanj’ to match the format used by complex
     repr.

   - bpo-27842(63): The csv.DictReader now returns rows of type
     OrderedDict.  (Contributed by Steve Holden.)

   - Remove support for passing a file descriptor to os.access.  It
     never worked but previously didn’t raise.

   - bpo-12885(64): Fix error when distutils encounters symlink.

   - bpo-27881(65): Fixed possible bugs when setting
     sqlite3.Connection.isolation_level.  Based on patch by Xiang Zhang.

   - bpo-27861(66): Fixed a crash in sqlite3.Connection.cursor() when a
     factory creates not a cursor.  Patch by Xiang Zhang.

   - bpo-19884(67): Avoid spurious output on OS X with Gnu Readline.

   - bpo-27706(68): Restore deterministic behavior of
     random.Random().seed() for string seeds using seeding version 1.
     Allows sequences of calls to random() to exactly match those
     obtained in Python 2.  Patch by Nofar Schnider.

   - bpo-10513(69): Fix a regression in Connection.commit().  Statements
     should not be reset after a commit.

   - bpo-12319(70): Chunked transfer encoding support added to
     http.client.HTTPConnection requests.  The
     urllib.request.AbstractHTTPHandler class does not enforce a
     Content-Length header any more.  If a HTTP request has a file or
     iterable body, but no Content-Length header, the library now falls
     back to use chunked transfer-encoding.

   - A new version of typing.py from ‘https://github.com/python/typing’:
     - Collection (only for 3.6) (bpo-27598(71)) - Add FrozenSet to
     __all__ (upstream #261) - fix crash in _get_type_vars() (upstream
     #259) - Remove the dict constraint in ForwardRef._eval_type
     (upstream #252)

   - bpo-27832(72): Make ‘_normalize’ parameter to ‘Fraction’
     constructor keyword-only, so that ‘Fraction(2, 3, 4)’ now raises
     ‘TypeError’.

   - bpo-27539(73): Fix unnormalised ‘Fraction.__pow__’ result in the
     case of negative exponent and negative base.

   - bpo-21718(74): cursor.description is now available for queries
     using CTEs.

   - bpo-27819(75): In distutils sdists, simply produce the «gztar»
     (gzipped tar format) distributions on all platforms unless
     «formats» is supplied.

   - bpo-2466(76): posixpath.ismount now correctly recognizes mount
     points which the user does not have permission to access.

   - bpo-9998(77): On Linux, ctypes.util.find_library now looks in
     LD_LIBRARY_PATH for shared libraries.

   - bpo-27573(78): exit message for code.interact is now configurable.

   - bpo-27930(79): Improved behaviour of
     logging.handlers.QueueListener.  Thanks to Paulo Andrade and Petr
     Viktorin for the analysis and patch.

   - bpo-6766(80): Distributed reference counting added to
     multiprocessing to support nesting of shared values / proxy
     objects.

   - bpo-21201(81): Improves readability of multiprocessing error
     message.  Thanks to Wojciech Walczak for patch.

   - asyncio: Add set_protocol / get_protocol to Transports.

   - bpo-27456(82): asyncio: Set TCP_NODELAY by default.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28732

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28485

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28037

   (4) https://bugs.python.org/issue?@action=redirect&bpo=25283

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24454

   (6) https://bugs.python.org/issue?@action=redirect&bpo=10740

   (7) https://bugs.python.org/issue?@action=redirect&bpo=17941

   (8) https://bugs.python.org/issue?@action=redirect&bpo=22493

   (9) https://bugs.python.org/issue?@action=redirect&bpo=26885

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28070

   (11) https://bugs.python.org/issue?@action=redirect&bpo=19500

   (12) https://bugs.python.org/issue?@action=redirect&bpo=28022

   (13) https://bugs.python.org/issue?@action=redirect&bpo=28043

   (14) https://bugs.python.org/issue?@action=redirect&bpo=24693

   (15) https://bugs.python.org/issue?@action=redirect&bpo=17909

   (16) https://bugs.python.org/issue?@action=redirect&bpo=27137

   (17) https://bugs.python.org/issue?@action=redirect&bpo=1703178

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28019

   (19) https://bugs.python.org/issue?@action=redirect&bpo=18401

   (20) https://bugs.python.org/issue?@action=redirect&bpo=25969

   (21) https://bugs.python.org/issue?@action=redirect&bpo=14977

   (22) https://bugs.python.org/issue?@action=redirect&bpo=28082

   (23) https://bugs.python.org/issue?@action=redirect&bpo=28025

   (24) https://bugs.python.org/issue?@action=redirect&bpo=23591

   (25) https://bugs.python.org/issue?@action=redirect&bpo=433028

   (26) https://bugs.python.org/issue?@action=redirect&bpo=24594

   (27) https://bugs.python.org/issue?@action=redirect&bpo=17582

   (28) https://bugs.python.org/issue?@action=redirect&bpo=28047

   (29) https://bugs.python.org/issue?@action=redirect&bpo=27576

   (30) https://bugs.python.org/issue?@action=redirect&bpo=28027

   (31) https://bugs.python.org/issue?@action=redirect&bpo=27445

   (32) https://bugs.python.org/issue?@action=redirect&bpo=24277

   (33) https://bugs.python.org/issue?@action=redirect&bpo=22450

   (34) https://bugs.python.org/issue?@action=redirect&bpo=28005

   (35) https://bugs.python.org/issue?@action=redirect&bpo=26667

   (36) https://bugs.python.org/issue?@action=redirect&bpo=27570

   (37) https://bugs.python.org/issue?@action=redirect&bpo=22233

   (38) https://bugs.python.org/issue?@action=redirect&bpo=27331

   (39) https://bugs.python.org/issue?@action=redirect&bpo=27988

   (40) https://bugs.python.org/issue?@action=redirect&bpo=16113

   (41) https://bugs.python.org/issue?@action=redirect&bpo=27776

   (42) https://peps.python.org/pep-0524/

   (43) https://bugs.python.org/issue?@action=redirect&bpo=27778

   (44) https://peps.python.org/pep-0524/

   (45) https://bugs.python.org/issue?@action=redirect&bpo=27691

   (46) https://bugs.python.org/issue?@action=redirect&bpo=18844

   (47) https://bugs.python.org/issue?@action=redirect&bpo=25761

   (48) https://bugs.python.org/issue?@action=redirect&bpo=26798

   (49) https://bugs.python.org/issue?@action=redirect&bpo=26032

   (50) https://bugs.python.org/issue?@action=redirect&bpo=25596

   (51) https://bugs.python.org/issue?@action=redirect&bpo=27928

   (52) https://bugs.python.org/issue?@action=redirect&bpo=27850

   (53) https://www.cve.org/CVERecord?id=CVE-2016-2183

   (54) https://bugs.python.org/issue?@action=redirect&bpo=27766

   (55) https://bugs.python.org/issue?@action=redirect&bpo=25387

   (56) https://bugs.python.org/issue?@action=redirect&bpo=27866

   (57) https://bugs.python.org/issue?@action=redirect&bpo=27744

   (58) https://bugs.python.org/issue?@action=redirect&bpo=26470

   (59) https://bugs.python.org/issue?@action=redirect&bpo=11620

   (60) https://bugs.python.org/issue?@action=redirect&bpo=11734

   (61) https://bugs.python.org/issue?@action=redirect&bpo=27919

   (62) https://bugs.python.org/issue?@action=redirect&bpo=23229

   (63) https://bugs.python.org/issue?@action=redirect&bpo=27842

   (64) https://bugs.python.org/issue?@action=redirect&bpo=12885

   (65) https://bugs.python.org/issue?@action=redirect&bpo=27881

   (66) https://bugs.python.org/issue?@action=redirect&bpo=27861

   (67) https://bugs.python.org/issue?@action=redirect&bpo=19884

   (68) https://bugs.python.org/issue?@action=redirect&bpo=27706

   (69) https://bugs.python.org/issue?@action=redirect&bpo=10513

   (70) https://bugs.python.org/issue?@action=redirect&bpo=12319

   (71) https://bugs.python.org/issue?@action=redirect&bpo=27598

   (72) https://bugs.python.org/issue?@action=redirect&bpo=27832

   (73) https://bugs.python.org/issue?@action=redirect&bpo=27539

   (74) https://bugs.python.org/issue?@action=redirect&bpo=21718

   (75) https://bugs.python.org/issue?@action=redirect&bpo=27819

   (76) https://bugs.python.org/issue?@action=redirect&bpo=2466

   (77) https://bugs.python.org/issue?@action=redirect&bpo=9998

   (78) https://bugs.python.org/issue?@action=redirect&bpo=27573

   (79) https://bugs.python.org/issue?@action=redirect&bpo=27930

   (80) https://bugs.python.org/issue?@action=redirect&bpo=6766

   (81) https://bugs.python.org/issue?@action=redirect&bpo=21201

   (82) https://bugs.python.org/issue?@action=redirect&bpo=27456


File: python.info,  Node: IDLE<52>,  Next: C API<71>,  Prev: Library<184>,  Up: Python 3 6 0 beta 1

1.24.92.3 IDLE
..............

   - bpo-15308(1): Add “interrupt execution” (^C) to Shell menu.  Patch
     by Roger Serwy, updated by Bayard Randel.

   - bpo-27922(2): Stop IDLE tests from “flashing” gui widgets on the
     screen.

   - bpo-27891(3): Consistently group and sort imports within idlelib
     modules.

   - bpo-17642(4): add larger font sizes for classroom projection.

   - Add version to title of IDLE help window.

   - bpo-25564(5): In section on IDLE – console differences, mention
     that using exec means that __builtins__ is defined for each
     statement.

   - bpo-27821(6): Fix 3.6.0a3 regression that prevented custom key sets
     from being selected when no custom theme was defined.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15308

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27922

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27891

   (4) https://bugs.python.org/issue?@action=redirect&bpo=17642

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25564

   (6) https://bugs.python.org/issue?@action=redirect&bpo=27821


File: python.info,  Node: C API<71>,  Next: Tests<73>,  Prev: IDLE<52>,  Up: Python 3 6 0 beta 1

1.24.92.4 C API
...............

   - bpo-26900(1): Excluded underscored names and other private API from
     limited API.

   - bpo-26027(2): Add support for path-like objects in
     PyUnicode_FSConverter() & PyUnicode_FSDecoder().

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26900

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26027


File: python.info,  Node: Tests<73>,  Next: Build<84>,  Prev: C API<71>,  Up: Python 3 6 0 beta 1

1.24.92.5 Tests
...............

   - bpo-27427(1): Additional tests for the math module.  Patch by
     Francisco Couzo.

   - bpo-27953(2): Skip math and cmath tests that fail on OS X 10.4 due
     to a poor libm implementation of tan.

   - bpo-26040(3): Improve test_math and test_cmath coverage and rigour.
     Patch by Jeff Allen.

   - bpo-27787(4): Call gc.collect() before checking each test for
     «dangling threads», since the dangling threads are weak references.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27427

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27953

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26040

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27787


File: python.info,  Node: Build<84>,  Next: Tools/Demos<51>,  Prev: Tests<73>,  Up: Python 3 6 0 beta 1

1.24.92.6 Build
...............

   - bpo-27566(1): Fix clean target in freeze makefile (patch by Lisa
     Roach)

   - bpo-27705(2): Update message in validate_ucrtbase.py

   - bpo-27976(3): Deprecate building _ctypes with the bundled copy of
     libffi on non-OSX UNIX platforms.

   - bpo-27983(4): Cause lack of llvm-profdata tool when using clang as
     required for PGO linking to be a configure time error rather than
     make time when ‘--with-optimizations’ is enabled.  Also improve our
     ability to find the llvm-profdata tool on MacOS and some Linuxes.

   - bpo-21590(5): Support for DTrace and SystemTap probes.

   - bpo-26307(6): The profile-opt build now applies PGO to the built-in
     modules.

   - bpo-26359(7): Add the –with-optimizations flag to turn on LTO and
     PGO build support when available.

   - bpo-27917(8): Set platform triplets for Android builds.

   - bpo-25825(9): Update references to the $(LIBPL) installation path
     on AIX. This path was changed in 3.2a4.

   - Update OS X installer to use SQLite 3.14.1 and XZ 5.2.2.

   - bpo-21122(10): Fix LTO builds on OS X.

   - bpo-17128(11): Build OS X installer with a private copy of OpenSSL.
     Also provide a sample Install Certificates command script to
     install a set of root certificates from the third-party certifi
     module.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27566

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27705

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27976

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27983

   (5) https://bugs.python.org/issue?@action=redirect&bpo=21590

   (6) https://bugs.python.org/issue?@action=redirect&bpo=26307

   (7) https://bugs.python.org/issue?@action=redirect&bpo=26359

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27917

   (9) https://bugs.python.org/issue?@action=redirect&bpo=25825

   (10) https://bugs.python.org/issue?@action=redirect&bpo=21122

   (11) https://bugs.python.org/issue?@action=redirect&bpo=17128


File: python.info,  Node: Tools/Demos<51>,  Next: Windows<72>,  Prev: Build<84>,  Up: Python 3 6 0 beta 1

1.24.92.7 Tools/Demos
.....................

   - bpo-27952(1): Get Tools/scripts/fixcid.py working with Python 3 and
     the current «re» module, avoid invalid Python backslash escapes,
     and fix a bug parsing escaped C quote signs.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27952


File: python.info,  Node: Windows<72>,  Prev: Tools/Demos<51>,  Up: Python 3 6 0 beta 1

1.24.92.8 Windows
.................

   - bpo-28065(1): Update xz dependency to 5.2.2 and build it from
     source.

   - bpo-25144(2): Ensures TargetDir is set before continuing with
     custom install.

   - bpo-1602(3): Windows console doesn’t input or print Unicode (PEP
     528)

   - bpo-27781(4): Change file system encoding on Windows to UTF-8 (PEP
     529)

   - bpo-27731(5): Opt-out of MAX_PATH on Windows 10

   - bpo-6135(6): Adds encoding and errors parameters to subprocess.

   - bpo-27959(7): Adds oem encoding, alias ansi to mbcs, move aliasmbcs
     to codec lookup.

   - bpo-27982(8): The functions of the winsound module now accept
     keyword arguments.

   - bpo-20366(9): Build full text search support into SQLite on
     Windows.

   - bpo-27756(10): Adds new icons for Python files and processes on
     Windows.  Designs by Cherry Wang.

   - bpo-27883(11): Update sqlite to 3.14.1.0 on Windows.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28065

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25144

   (3) https://bugs.python.org/issue?@action=redirect&bpo=1602

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27781

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27731

   (6) https://bugs.python.org/issue?@action=redirect&bpo=6135

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27959

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27982

   (9) https://bugs.python.org/issue?@action=redirect&bpo=20366

   (10) https://bugs.python.org/issue?@action=redirect&bpo=27756

   (11) https://bugs.python.org/issue?@action=redirect&bpo=27883


File: python.info,  Node: Python 3 6 0 alpha 4,  Next: Python 3 6 0 alpha 3,  Prev: Python 3 6 0 beta 1,  Up: Changelog

1.24.93 Python 3.6.0 alpha 4
----------------------------

'Release date: 2016-08-15'

* Menu:

* Core and Builtins: Core and Builtins<182>.
* Library: Library<185>.
* IDLE: IDLE<53>.
* Tests: Tests<74>.
* Windows: Windows<73>.
* Build: Build<85>.


File: python.info,  Node: Core and Builtins<182>,  Next: Library<185>,  Up: Python 3 6 0 alpha 4

1.24.93.1 Core and Builtins
...........................

   - bpo-27704(1): Optimized creating bytes and bytearray from byte-like
     objects and iterables.  Speed up to 3 times for short objects.
     Original patch by Naoki Inada.

   - bpo-26823(2): Large sections of repeated lines in tracebacks are
     now abbreviated as «[Previous line repeated {count} more times]» by
     the builtin traceback rendering.  Patch by Emanuel Barry.

   - bpo-27574(3): Decreased an overhead of parsing keyword arguments in
     functions implemented with using Argument Clinic.

   - bpo-22557(4): Now importing already imported modules is up to 2.5
     times faster.

   - bpo-17596(5): Include <wincrypt.h> to help with Min GW building.

   - bpo-17599(6): On Windows, rename the privately defined
     REPARSE_DATA_BUFFER structure to avoid conflicting with the
     definition from Min GW.

   - bpo-27507(7): Add integer overflow check in bytearray.extend().
     Patch by Xiang Zhang.

   - bpo-27581(8): Don’t rely on wrapping for overflow check in
     PySequence_Tuple().  Patch by Xiang Zhang.

   - bpo-1621(9): Avoid signed integer overflow in list and tuple
     operations.  Patch by Xiang Zhang.

   - bpo-27419(10): Standard __import__() no longer look up «__import__»
     in globals or builtins for importing submodules or «from import».
     Fixed a crash if raise a warning about unabling to resolve package
     from __spec__ or __package__.

   - bpo-27083(11): Respect the PYTHONCASEOK environment variable under
     Windows.

   - bpo-27514(12): Make having too many statically nested blocks a
     SyntaxError instead of SystemError.

   - bpo-27366(13): Implemented PEP 487(14) (Simpler customization of
     class creation).  Upon subclassing, the __init_subclass__
     classmethod is called on the base class.  Descriptors are
     initialized with __set_name__ after class creation.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27704

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26823

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27574

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22557

   (5) https://bugs.python.org/issue?@action=redirect&bpo=17596

   (6) https://bugs.python.org/issue?@action=redirect&bpo=17599

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27507

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27581

   (9) https://bugs.python.org/issue?@action=redirect&bpo=1621

   (10) https://bugs.python.org/issue?@action=redirect&bpo=27419

   (11) https://bugs.python.org/issue?@action=redirect&bpo=27083

   (12) https://bugs.python.org/issue?@action=redirect&bpo=27514

   (13) https://bugs.python.org/issue?@action=redirect&bpo=27366

   (14) https://peps.python.org/pep-0487/


File: python.info,  Node: Library<185>,  Next: IDLE<53>,  Prev: Core and Builtins<182>,  Up: Python 3 6 0 alpha 4

1.24.93.2 Library
.................

   - bpo-26027(1): Add PEP 519(2)/__fspath__() support to the os and
     os.path modules.  Includes code from Jelle Zijlstra.  (See also:
     bpo-27524(3))

   - bpo-27598(4): Add Collections to collections.abc.  Patch by Ivan
     Levkivskyi, docs by Neil Girdhar.

   - bpo-25958(5): Support «anti-registration» of special methods from
     various ABCs, like __hash__, __iter__ or __len__.  All these (and
     several more) can be set to None in an implementation class and the
     behavior will be as if the method is not defined at all.
     (Previously, this mechanism existed only for __hash__, to make
     mutable classes unhashable.)  Code contributed by Andrew Barnert
     and Ivan Levkivskyi.

   - bpo-16764(6): Support keyword arguments to zlib.decompress().
     Patch by Xiang Zhang.

   - bpo-27736(7): Prevent segfault after interpreter re-initialization
     due to ref count problem introduced in code for bpo-27038(8) in
     3.6.0a3.  Patch by Xiang Zhang.

   - bpo-25628(9): The 'verbose' and 'rename' parameters for
     collections.namedtuple are now keyword-only.

   - bpo-12345(10): Add mathematical constant tau to math and cmath.
     See also PEP 628(11).

   - bpo-26823(12): traceback.StackSummary.format now abbreviates large
     sections of repeated lines as «[Previous line repeated {count} more
     times]» (this change then further affects other traceback display
     operations in the module).  Patch by Emanuel Barry.

   - bpo-27664(13): Add to
     concurrent.futures.thread.ThreadPoolExecutor() the ability to
     specify a thread name prefix.

   - bpo-27181(14): Add geometric_mean and harmonic_mean to statistics
     module.

   - bpo-27573(15): code.interact now prints an message when exiting.

   - bpo-6422(16): Add autorange method to timeit.Timer objects.

   - bpo-27773(17): Correct some memory management errors
     server_hostname in _ssl.wrap_socket().

   - bpo-26750(18): unittest.mock.create_autospec() now works properly
     for subclasses of property() and other data descriptors.  Removes
     the never publicly used, never documented
     unittest.mock.DescriptorTypes tuple.

   - bpo-26754(19): Undocumented support of general bytes-like objects
     as path in compile() and similar functions is now deprecated.

   - bpo-26800(20): Undocumented support of general bytes-like objects
     as paths in os functions is now deprecated.

   - bpo-26981(21): Add _order_ compatibility shim to enum.Enum for
     Python 2/3 code bases.

   - bpo-27661(22): Added tzinfo keyword argument to datetime.combine.

   - In the curses module, raise an error if window.getstr() or
     window.instr() is passed a negative value.

   - bpo-27783(23): Fix possible usage of uninitialized memory in
     operator.methodcaller.

   - bpo-27774(24): Fix possible Py_DECREF on unowned object in _sre.

   - bpo-27760(25): Fix possible integer overflow in binascii.b2a_qp.

   - bpo-27758(26): Fix possible integer overflow in the _csv module for
     large record lengths.

   - bpo-27568(27): Prevent HTTPoxy attack ( CVE 2016-1000110(28)).
     Ignore the HTTP_PROXY variable when REQUEST_METHOD environment is
     set, which indicates that the script is in CGI mode.

   - bpo-7063(29): Remove dead code from the «array» module’s slice
     handling.  Patch by Chuck.

   - bpo-27656(30): Do not assume sched.h defines any SCHED_* constants.

   - bpo-27130(31): In the «zlib» module, fix handling of large buffers
     (typically 4 GiB) when compressing and decompressing.  Previously,
     inputs were limited to 4 GiB, and compression and decompression
     operations did not properly handle results of 4 GiB.

   - bpo-24773(32): Implemented PEP 495(33) (Local Time Disambiguation).

   - Expose the EPOLLEXCLUSIVE constant (when it is defined) in the
     select module.

   - bpo-27567(34): Expose the EPOLLRDHUP and POLLRDHUP constants in the
     select module.

   - bpo-1621(35): Avoid signed int negation overflow in the «audioop»
     module.

   - bpo-27533(36): Release GIL in nt._isdir

   - bpo-17711(37): Fixed unpickling by the persistent ID with protocol
     0.  Original patch by Alexandre Vassalotti.

   - bpo-27522(38): Avoid an unintentional reference cycle in
     email.feedparser.

   - bpo-27512(39): Fix a segfault when os.fspath() called an
     __fspath__() method that raised an exception.  Patch by Xiang
     Zhang.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26027

   (2) https://peps.python.org/pep-0519/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27524

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27598

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25958

   (6) https://bugs.python.org/issue?@action=redirect&bpo=16764

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27736

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27038

   (9) https://bugs.python.org/issue?@action=redirect&bpo=25628

   (10) https://bugs.python.org/issue?@action=redirect&bpo=12345

   (11) https://peps.python.org/pep-0628/

   (12) https://bugs.python.org/issue?@action=redirect&bpo=26823

   (13) https://bugs.python.org/issue?@action=redirect&bpo=27664

   (14) https://bugs.python.org/issue?@action=redirect&bpo=27181

   (15) https://bugs.python.org/issue?@action=redirect&bpo=27573

   (16) https://bugs.python.org/issue?@action=redirect&bpo=6422

   (17) https://bugs.python.org/issue?@action=redirect&bpo=27773

   (18) https://bugs.python.org/issue?@action=redirect&bpo=26750

   (19) https://bugs.python.org/issue?@action=redirect&bpo=26754

   (20) https://bugs.python.org/issue?@action=redirect&bpo=26800

   (21) https://bugs.python.org/issue?@action=redirect&bpo=26981

   (22) https://bugs.python.org/issue?@action=redirect&bpo=27661

   (23) https://bugs.python.org/issue?@action=redirect&bpo=27783

   (24) https://bugs.python.org/issue?@action=redirect&bpo=27774

   (25) https://bugs.python.org/issue?@action=redirect&bpo=27760

   (26) https://bugs.python.org/issue?@action=redirect&bpo=27758

   (27) https://bugs.python.org/issue?@action=redirect&bpo=27568

   (28) https://www.cve.org/CVERecord?id=CVE-2016-1000110

   (29) https://bugs.python.org/issue?@action=redirect&bpo=7063

   (30) https://bugs.python.org/issue?@action=redirect&bpo=27656

   (31) https://bugs.python.org/issue?@action=redirect&bpo=27130

   (32) https://bugs.python.org/issue?@action=redirect&bpo=24773

   (33) https://peps.python.org/pep-0495/

   (34) https://bugs.python.org/issue?@action=redirect&bpo=27567

   (35) https://bugs.python.org/issue?@action=redirect&bpo=1621

   (36) https://bugs.python.org/issue?@action=redirect&bpo=27533

   (37) https://bugs.python.org/issue?@action=redirect&bpo=17711

   (38) https://bugs.python.org/issue?@action=redirect&bpo=27522

   (39) https://bugs.python.org/issue?@action=redirect&bpo=27512


File: python.info,  Node: IDLE<53>,  Next: Tests<74>,  Prev: Library<185>,  Up: Python 3 6 0 alpha 4

1.24.93.3 IDLE
..............

   - bpo-27714(1): text_textview and test_autocomplete now pass when
     re-run in the same process.  This occurs when test_idle fails when
     run with the -w option but without -jn.  Fix warning from
     test_config.

   - bpo-27621(2): Put query response validation error messages in the
     query box itself instead of in a separate messagebox.  Redo tests
     to match.  Add Mac OSX refinements.  Original patch by Mark
     Roseman.

   - bpo-27620(3): Escape key now closes Query box as cancelled.

   - bpo-27609(4): IDLE: tab after initial whitespace should tab, not
     autocomplete.  This fixes problem with writing docstrings at least
     twice indented.

   - bpo-27609(5): Explicitly return None when there are also non-None
     returns.  In a few cases, reverse a condition and eliminate a
     return.

   - bpo-25507(6): IDLE no longer runs buggy code because of its tkinter
     imports.  Users must include the same imports required to run
     directly in Python.

   - bpo-27173(7): Add “IDLE Modern Unix” to the built-in key sets.
     Make the default key set depend on the platform.  Add tests for the
     changes to the config module.

   - bpo-27452(8): add line counter and crc to IDLE configHandler test
     dump.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27714

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27621

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27620

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27609

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27609

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25507

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27173

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27452


File: python.info,  Node: Tests<74>,  Next: Windows<73>,  Prev: IDLE<53>,  Up: Python 3 6 0 alpha 4

1.24.93.4 Tests
...............

   - bpo-25805(1): Skip a test in test_pkgutil as needed that doesn’t
     work when ‘__name__ == __main__’.  Patch by SilentGhost.

   - bpo-27472(2): Add test.support.unix_shell as the path to the
     default shell.

   - bpo-27369(3): In test_pyexpat, avoid testing an error message
     detail that changed in Expat 2.2.0.

   - bpo-27594(4): Prevent assertion error when running test_ast with
     coverage enabled: ensure code object has a valid first line number.
     Patch suggested by Ivan Levkivskyi.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25805

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27472

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27369

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27594


File: python.info,  Node: Windows<73>,  Next: Build<85>,  Prev: Tests<74>,  Up: Python 3 6 0 alpha 4

1.24.93.5 Windows
.................

   - bpo-27647(1): Update bundled Tcl/Tk to 8.6.6.

   - bpo-27610(2): Adds PEP 514(3) metadata to Windows installer

   - bpo-27469(4): Adds a shell extension to the launcher so that drag
     and drop works correctly.

   - bpo-27309(5): Enables proper Windows styles in python[w].exe
     manifest.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27647

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27610

   (3) https://peps.python.org/pep-0514/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27469

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27309


File: python.info,  Node: Build<85>,  Prev: Windows<73>,  Up: Python 3 6 0 alpha 4

1.24.93.6 Build
...............

   - bpo-27713(1): Suppress spurious build warnings when updating
     importlib’s bootstrap files.  Patch by Xiang Zhang

   - bpo-25825(2): Correct the references to Modules/python.exp, which
     is required on AIX. The references were accidentally changed in
     3.5.0a1.

   - bpo-27453(3): CPP invocation in configure must use CPPFLAGS. Patch
     by Chi Hsuan Yen.

   - bpo-27641(4): The configure script now inserts comments into the
     makefile to prevent the pgen and _freeze_importlib executables from
     being cross-compiled.

   - bpo-26662(5): Set PYTHON_FOR_GEN in configure as the Python program
     to be used for file generation during the build.

   - bpo-10910(6): Avoid C++ compilation errors on FreeBSD and OS X.
     Also update FreedBSD version checks for the original ctype UTF-8
     workaround.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27713

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25825

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27453

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27641

   (5) https://bugs.python.org/issue?@action=redirect&bpo=26662

   (6) https://bugs.python.org/issue?@action=redirect&bpo=10910


File: python.info,  Node: Python 3 6 0 alpha 3,  Next: Python 3 6 0 alpha 2,  Prev: Python 3 6 0 alpha 4,  Up: Changelog

1.24.94 Python 3.6.0 alpha 3
----------------------------

'Release date: 2016-07-11'

* Menu:

* Security: Security<54>.
* Core and Builtins: Core and Builtins<183>.
* Library: Library<186>.
* IDLE: IDLE<54>.
* C API: C API<72>.
* Build: Build<86>.
* Tools/Demos: Tools/Demos<52>.
* Documentation: Documentation<74>.
* Tests: Tests<75>.


File: python.info,  Node: Security<54>,  Next: Core and Builtins<183>,  Up: Python 3 6 0 alpha 3

1.24.94.1 Security
..................

   - bpo-27278(1): Fix os.urandom() implementation using getrandom() on
     Linux.  Truncate size to INT_MAX and loop until we collected enough
     random bytes, instead of casting a directly Py_ssize_t to int.

   - bpo-22636(2): Avoid shell injection problems with
     ctypes.util.find_library().

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27278

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22636


File: python.info,  Node: Core and Builtins<183>,  Next: Library<186>,  Prev: Security<54>,  Up: Python 3 6 0 alpha 3

1.24.94.2 Core and Builtins
...........................

   - bpo-27473(1): Fixed possible integer overflow in bytes and
     bytearray concatenations.  Patch by Xiang Zhang.

   - bpo-23034(2): The output of a special Python build with defined
     COUNT_ALLOCS, SHOW_ALLOC_COUNT or SHOW_TRACK_COUNT macros is now
     off by default.  It can be re-enabled using the «-X showalloccount»
     option.  It now outputs to stderr instead of stdout.

   - bpo-27443(3): __length_hint__() of bytearray iterators no longer
     return a negative integer for a resized bytearray.

   - bpo-27007(4): The fromhex() class methods of bytes and bytearray
     subclasses now return an instance of corresponding subclass.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27473

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23034

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27443

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27007


File: python.info,  Node: Library<186>,  Next: IDLE<54>,  Prev: Core and Builtins<183>,  Up: Python 3 6 0 alpha 3

1.24.94.3 Library
.................

   - bpo-26844(1): Fix error message for imp.find_module() to refer to
     “path” instead of “name”.  Patch by Lev Maximov.

   - bpo-23804(2): Fix SSL zero-length recv() calls to not block and not
     raise an error about unclean EOF.

   - bpo-27466(3): Change time format returned by
     http.cookie.time2netscape, confirming the netscape cookie format
     and making it consistent with documentation.

   - bpo-21708(4): Deprecated dbm.dumb behavior that differs from common
     dbm behavior: creating a database in “r” and “w” modes and
     modifying a database in “r” mode.

   - bpo-26721(5): Change the socketserver.StreamRequestHandler.wfile
     attribute to implement BufferedIOBase.  In particular, the write()
     method no longer does partial writes.

   - bpo-22115(6): Added methods trace_add, trace_remove and trace_info
     in the tkinter.Variable class.  They replace old methods
     trace_variable, trace, trace_vdelete and trace_vinfo that use
     obsolete Tcl commands and might not work in future versions of Tcl.
     Fixed old tracing methods: trace_vdelete() with wrong mode no
     longer break tracing, trace_vinfo() now always returns a list of
     pairs of strings, tracing in the «u» mode now works.

   - bpo-26243(7): Only the level argument to zlib.compress() is keyword
     argument now.  The first argument is positional-only.

   - bpo-27038(8): Expose the DirEntry type as os.DirEntry.  Code patch
     by Jelle Zijlstra.

   - bpo-27186(9): Update os.fspath()/PyOS_FSPath() to check the return
     value of __fspath__() to be either str or bytes.

   - bpo-18726(10): All optional parameters of the dump(), dumps(),
     load() and loads() functions and JSONEncoder and JSONDecoder class
     constructors in the json module are now keyword-only.

   - bpo-27319(11): Methods selection_set(), selection_add(),
     selection_remove() and selection_toggle() of ttk.TreeView now allow
     passing multiple items as multiple arguments instead of passing
     them as a tuple.  Deprecated undocumented ability of calling the
     selection() method with arguments.

   - bpo-27079(12): Fixed curses.ascii functions isblank(), iscntrl()
     and ispunct().

   - bpo-27294(13): Numerical state in the repr for Tkinter event
     objects is now represented as a combination of known flags.

   - bpo-27177(14): Match objects in the re module now support
     index-like objects as group indices.  Based on patches by Jeroen
     Demeyer and Xiang Zhang.

   - bpo-26754(15): Some functions (compile() etc) accepted a filename
     argument encoded as an iterable of integers.  Now only strings and
     byte-like objects are accepted.

   - bpo-26536(16): socket.ioctl now supports SIO_LOOPBACK_FAST_PATH.
     Patch by Daniel Stokes.

   - bpo-27048(17): Prevents distutils failing on Windows when
     environment variables contain non-ASCII characters

   - bpo-27330(18): Fixed possible leaks in the ctypes module.

   - bpo-27238(19): Got rid of bare excepts in the turtle module.
     Original patch by Jelle Zijlstra.

   - bpo-27122(20): When an exception is raised within the context being
     managed by a contextlib.ExitStack() and one of the exit stack
     generators catches and raises it in a chain, do not re-raise the
     original exception when exiting, let the new chained one through.
     This avoids the PEP 479(21) bug described in issue25782.

   - bpo-16864(22): sqlite3.Cursor.lastrowid now supports REPLACE
     statement.  Initial patch by Alex LordThorsen.

   - bpo-26386(23): Fixed ttk.TreeView selection operations with item
     id’s containing spaces.

   - bpo-8637(24): Honor a pager set by the env var MANPAGER (in
     preference to one set by the env var PAGER).

   - bpo-16182(25): Fix various functions in the «readline» module to
     use the locale encoding, and fix get_begidx() and get_endidx() to
     return code point indexes.

   - bpo-27392(26): Add loop.connect_accepted_socket().  Patch by Jim
     Fulton.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26844

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23804

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27466

   (4) https://bugs.python.org/issue?@action=redirect&bpo=21708

   (5) https://bugs.python.org/issue?@action=redirect&bpo=26721

   (6) https://bugs.python.org/issue?@action=redirect&bpo=22115

   (7) https://bugs.python.org/issue?@action=redirect&bpo=26243

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27038

   (9) https://bugs.python.org/issue?@action=redirect&bpo=27186

   (10) https://bugs.python.org/issue?@action=redirect&bpo=18726

   (11) https://bugs.python.org/issue?@action=redirect&bpo=27319

   (12) https://bugs.python.org/issue?@action=redirect&bpo=27079

   (13) https://bugs.python.org/issue?@action=redirect&bpo=27294

   (14) https://bugs.python.org/issue?@action=redirect&bpo=27177

   (15) https://bugs.python.org/issue?@action=redirect&bpo=26754

   (16) https://bugs.python.org/issue?@action=redirect&bpo=26536

   (17) https://bugs.python.org/issue?@action=redirect&bpo=27048

   (18) https://bugs.python.org/issue?@action=redirect&bpo=27330

   (19) https://bugs.python.org/issue?@action=redirect&bpo=27238

   (20) https://bugs.python.org/issue?@action=redirect&bpo=27122

   (21) https://peps.python.org/pep-0479/

   (22) https://bugs.python.org/issue?@action=redirect&bpo=16864

   (23) https://bugs.python.org/issue?@action=redirect&bpo=26386

   (24) https://bugs.python.org/issue?@action=redirect&bpo=8637

   (25) https://bugs.python.org/issue?@action=redirect&bpo=16182

   (26) https://bugs.python.org/issue?@action=redirect&bpo=27392


File: python.info,  Node: IDLE<54>,  Next: C API<72>,  Prev: Library<186>,  Up: Python 3 6 0 alpha 3

1.24.94.4 IDLE
..............

   - bpo-27477(1): IDLE search dialogs now use ttk widgets.

   - bpo-27173(2): Add “IDLE Modern Unix” to the built-in key sets.
     Make the default key set depend on the platform.  Add tests for the
     changes to the config module.

   - bpo-27452(3): make command line «idle-test> python test_help.py»
     work.  __file__ is relative when python is started in the file’s
     directory.

   - bpo-27452(4): add line counter and crc to IDLE configHandler test
     dump.

   - bpo-27380(5): IDLE: add query.py with base Query dialog and ttk
     widgets.  Module had subclasses SectionName, ModuleName, and
     HelpSource, which are used to get information from users by
     configdialog and file =>Load Module.  Each subclass has itw own
     validity checks.  Using ModuleName allows users to edit bad module
     names instead of starting over.  Add tests and delete the two files
     combined into the new one.

   - bpo-27372(6): Test_idle no longer changes the locale.

   - bpo-27365(7): Allow non-ascii chars in IDLE NEWS.txt, for
     contributor names.

   - bpo-27245(8): IDLE: Cleanly delete custom themes and key bindings.
     Previously, when IDLE was started from a console or by import, a
     cascade of warnings was emitted.  Patch by Serhiy Storchaka.

   - bpo-24137(9): Run IDLE, test_idle, and htest with tkinter default
     root disabled.  Fix code and tests that fail with this restriction.
     Fix htests to not create a second and redundant root and mainloop.

   - bpo-27310(10): Fix IDLE.app failure to launch on OS X due to
     vestigial import.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27477

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27173

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27452

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27452

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27380

   (6) https://bugs.python.org/issue?@action=redirect&bpo=27372

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27365

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27245

   (9) https://bugs.python.org/issue?@action=redirect&bpo=24137

   (10) https://bugs.python.org/issue?@action=redirect&bpo=27310


File: python.info,  Node: C API<72>,  Next: Build<86>,  Prev: IDLE<54>,  Up: Python 3 6 0 alpha 3

1.24.94.5 C API
...............

   - bpo-26754(1): PyUnicode_FSDecoder() accepted a filename argument
     encoded as an iterable of integers.  Now only strings and byte-like
     objects are accepted.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26754


File: python.info,  Node: Build<86>,  Next: Tools/Demos<52>,  Prev: C API<72>,  Up: Python 3 6 0 alpha 3

1.24.94.6 Build
...............

   - bpo-28066(1): Fix the logic that searches build directories for
     generated include files when building outside the source tree.

   - bpo-27442(2): Expose the Android API level that python was built
     against, in sysconfig.get_config_vars() as “ANDROID_API_LEVEL”.

   - bpo-27434(3): The interpreter that runs the cross-build, found in
     PATH, must now be of the same feature version (e.g.  3.6) as the
     source being built.

   - bpo-26930(4): Update Windows builds to use OpenSSL 1.0.2h.

   - bpo-23968(5): Rename the platform directory from plat-$(MACHDEP) to
     plat-$(PLATFORM_TRIPLET). Rename the config directory (LIBPL) from
     config-$(LDVERSION) to config-$(LDVERSION)-$(PLATFORM_TRIPLET).
     Install the platform specific _sysconfigdata module into the
     platform directory and rename it to include the ABIFLAGS.

   - Don’t use largefile support for GNU/Hurd.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28066

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27442

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27434

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26930

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23968


File: python.info,  Node: Tools/Demos<52>,  Next: Documentation<74>,  Prev: Build<86>,  Up: Python 3 6 0 alpha 3

1.24.94.7 Tools/Demos
.....................

   - bpo-27332(1): Fixed the type of the first argument of module-level
     functions generated by Argument Clinic.  Patch by Petr Viktorin.

   - bpo-27418(2): Fixed Tools/importbench/importbench.py.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27332

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27418


File: python.info,  Node: Documentation<74>,  Next: Tests<75>,  Prev: Tools/Demos<52>,  Up: Python 3 6 0 alpha 3

1.24.94.8 Documentation
.......................

   - bpo-19489(1): Moved the search box from the sidebar to the header
     and footer of each page.  Patch by Ammar Askar.

   - bpo-27285(2): Update documentation to reflect the deprecation of
     ‘pyvenv’ and normalize on the term «virtual environment».  Patch by
     Steve Piercy.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19489

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27285


File: python.info,  Node: Tests<75>,  Prev: Documentation<74>,  Up: Python 3 6 0 alpha 3

1.24.94.9 Tests
...............

   - bpo-27027(1): Added test.support.is_android that is True when this
     is an Android build.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27027


File: python.info,  Node: Python 3 6 0 alpha 2,  Next: Python 3 6 0 alpha 1,  Prev: Python 3 6 0 alpha 3,  Up: Changelog

1.24.95 Python 3.6.0 alpha 2
----------------------------

'Release date: 2016-06-13'

* Menu:

* Security: Security<55>.
* Core and Builtins: Core and Builtins<184>.
* Library: Library<187>.
* IDLE: IDLE<55>.
* Documentation: Documentation<75>.
* Tests: Tests<76>.
* Windows: Windows<74>.
* Build: Build<87>.
* C API: C API<73>.
* Tools/Demos: Tools/Demos<53>.


File: python.info,  Node: Security<55>,  Next: Core and Builtins<184>,  Up: Python 3 6 0 alpha 2

1.24.95.1 Security
..................

   - bpo-26556(1): Update expat to 2.1.1, fixes CVE 2015-1283(2).

   - Fix TLS stripping vulnerability in smtplib, CVE 2016-0772(3).
     Reported by Team Oststrom.

   - bpo-26839(4): On Linux, *note os.urandom(): 747. now calls
     ‘getrandom()’ with ‘GRND_NONBLOCK’ to fall back on reading
     ‘/dev/urandom’ if the urandom entropy pool is not initialized yet.
     Patch written by Colm Buckley.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26556

   (2) https://www.cve.org/CVERecord?id=CVE-2015-1283

   (3) https://www.cve.org/CVERecord?id=CVE-2016-0772

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26839


File: python.info,  Node: Core and Builtins<184>,  Next: Library<187>,  Prev: Security<55>,  Up: Python 3 6 0 alpha 2

1.24.95.2 Core and Builtins
...........................

   - bpo-27095(1): Simplified MAKE_FUNCTION and removed MAKE_CLOSURE
     opcodes.  Patch by Demur Rumed.

   - bpo-27190(2): Raise NotSupportedError if sqlite3 is older than
     3.3.1.  Patch by Dave Sawyer.

   - bpo-27286(3): Fixed compiling BUILD_MAP_UNPACK_WITH_CALL opcode.
     Calling function with generalized unpacking (PEP 448) and
     conflicting keyword names could cause undefined behavior.

   - bpo-27140(4): Added BUILD_CONST_KEY_MAP opcode.

   - bpo-27186(5): Add support for os.PathLike objects to open() (part
     of PEP 519(6)).

   - bpo-27066(7): Fixed SystemError if a custom opener (for open())
     returns a negative number without setting an exception.

   - bpo-26983(8): float() now always return an instance of exact float.
     The deprecation warning is emitted if __float__ returns an instance
     of a strict subclass of float.  In a future versions of Python this
     can be an error.

   - bpo-27097(9): Python interpreter is now about 7% faster due to
     optimized instruction decoding.  Based on patch by Demur Rumed.

   - bpo-26647(10): Python interpreter now uses 16-bit wordcode instead
     of bytecode.  Patch by Demur Rumed.

   - bpo-23275(11): Allow assigning to an empty target list in round
     brackets: () = iterable.

   - bpo-27243(12): Update the __aiter__ protocol: instead of returning
     an awaitable that resolves to an asynchronous iterator, the
     asynchronous iterator should be returned directly.  Doing the
     former will trigger a PendingDeprecationWarning.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27095

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27190

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27286

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27140

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27186

   (6) https://peps.python.org/pep-0519/

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27066

   (8) https://bugs.python.org/issue?@action=redirect&bpo=26983

   (9) https://bugs.python.org/issue?@action=redirect&bpo=27097

   (10) https://bugs.python.org/issue?@action=redirect&bpo=26647

   (11) https://bugs.python.org/issue?@action=redirect&bpo=23275

   (12) https://bugs.python.org/issue?@action=redirect&bpo=27243


File: python.info,  Node: Library<187>,  Next: IDLE<55>,  Prev: Core and Builtins<184>,  Up: Python 3 6 0 alpha 2

1.24.95.3 Library
.................

   - Comment out socket (SO_REUSEPORT) and posix (O_SHLOCK, O_EXLOCK)
     constants exposed on the API which are not implemented on GNU/Hurd.
     They would not work at runtime anyway.

   - bpo-27025(1): Generated names for Tkinter widgets are now more
     meaningful and recognizable.

   - bpo-25455(2): Fixed crashes in repr of recursive
     ElementTree.Element and functools.partial objects.

   - bpo-27294(3): Improved repr for Tkinter event objects.

   - bpo-20508(4): Improve exception message of
     IPv{4,6}Network.__getitem__.  Patch by Gareth Rees.

   - bpo-21386(5): Implement missing IPv4Address.is_global property.  It
     was documented since 07a5610bae9d.  Initial patch by Roger Luethi.

   - bpo-27029(6): Removed deprecated support of universal newlines mode
     from ZipFile.open().

   - bpo-27030(7): Unknown escapes consisting of ‘'\'’ and an ASCII
     letter in regular expressions now are errors.  The re.LOCALE flag
     now can be used only with bytes patterns.

   - bpo-27186(8): Add os.PathLike support to DirEntry (part of PEP
     519(9)).  Initial patch by Jelle Zijlstra.

   - bpo-20900(10): distutils register command now decodes HTTP
     responses correctly.  Initial patch by ingrid.

   - bpo-27186(11): Add os.PathLike support to pathlib, removing its
     provisional status (part of PEP 519).  Initial patch by Dusty
     Phillips.

   - bpo-27186(12): Add support for os.PathLike objects to os.fsencode()
     and os.fsdecode() (part of PEP 519(13)).

   - bpo-27186(14): Introduce os.PathLike and os.fspath() (part of PEP
     519(15)).

   - A new version of typing.py provides several new classes and
     features: @overload outside stubs, Reversible, DefaultDict, Text,
     ContextManager, Type[], NewType(), TYPE_CHECKING, and numerous bug
     fixes (note that some of the new features are not yet implemented
     in mypy or other static analyzers).  Also classes for PEP 492(16)
     (Awaitable, AsyncIterable, AsyncIterator) have been added (in fact
     they made it into 3.5.1 but were never mentioned).

   - bpo-25738(17): Stop http.server.BaseHTTPRequestHandler.send_error()
     from sending a message body for 205 Reset Content.  Also, don’t
     send Content header fields in responses that don’t have a body.
     Patch by Susumu Koshiba.

   - bpo-21313(18): Fix the «platform» module to tolerate when
     sys.version contains truncated build information.

   - bpo-23883(19): Added missing APIs to __all__ to match the
     documented APIs for the following modules: cgi, mailbox, mimetypes,
     plistlib and smtpd.  Patches by Jacek Kołodziej.

   - bpo-27164(20): In the zlib module, allow decompressing raw Deflate
     streams with a predefined zdict.  Based on patch by Xiang Zhang.

   - bpo-24291(21): Fix wsgiref.simple_server.WSGIRequestHandler to
     completely write data to the client.  Previously it could do
     partial writes and truncate data.  Also,
     wsgiref.handler.ServerHandler can now handle stdout doing partial
     writes, but this is deprecated.

   - bpo-21272(22): Use _sysconfigdata.py to initialize
     distutils.sysconfig.

   - bpo-19611(23): *note inspect: 82. now reports the implicit ‘.0’
     parameters generated by the compiler for comprehension and
     generator expression scopes as if they were positional-only
     parameters called ‘implicit0’.  Patch by Jelle Zijlstra.

   - bpo-26809(24): Add ‘__all__’ to *note string: d8.  Patch by Emanuel
     Barry.

   - bpo-26373(25): subprocess.Popen.communicate now correctly ignores
     BrokenPipeError when the child process dies before .communicate()
     is called in more/all circumstances.

   - signal, socket, and ssl module IntEnum constant name lookups now
     return a consistent name for values having multiple names.  Ex:
     signal.Signals(6) now refers to itself as signal.SIGALRM rather
     than flipping between that and signal.SIGIOT based on the
     interpreter’s hash randomization seed.

   - bpo-27167(26): Clarify the subprocess.CalledProcessError error
     message text when the child process died due to a signal.

   - bpo-25931(27): Don’t define socketserver.Forking* names on
     platforms such as Windows that do not support os.fork().

   - bpo-21776(28): distutils.upload now correctly handles HTTPError.
     Initial patch by Claudiu Popa.

   - bpo-26526(29): Replace custom parse tree validation in the parser
     module with a simple DFA validator.

   - bpo-27114(30): Fix SSLContext._load_windows_store_certs fails with
     PermissionError

   - bpo-18383(31): Avoid creating duplicate filters when using
     filterwarnings and simplefilter.  Based on patch by Alex Shkop.

   - bpo-23026(32): winreg.QueryValueEx() now return an integer for
     REG_QWORD type.

   - bpo-26741(33): subprocess.Popen destructor now emits a
     ResourceWarning warning if the child process is still running.

   - bpo-27056(34): Optimize pickle.load() and pickle.loads(), up to 10%
     faster to deserialize a lot of small objects.

   - bpo-21271(35): New keyword only parameters in reset_mock call.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27025

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25455

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27294

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20508

   (5) https://bugs.python.org/issue?@action=redirect&bpo=21386

   (6) https://bugs.python.org/issue?@action=redirect&bpo=27029

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27030

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27186

   (9) https://peps.python.org/pep-0519/

   (10) https://bugs.python.org/issue?@action=redirect&bpo=20900

   (11) https://bugs.python.org/issue?@action=redirect&bpo=27186

   (12) https://bugs.python.org/issue?@action=redirect&bpo=27186

   (13) https://peps.python.org/pep-0519/

   (14) https://bugs.python.org/issue?@action=redirect&bpo=27186

   (15) https://peps.python.org/pep-0519/

   (16) https://peps.python.org/pep-0492/

   (17) https://bugs.python.org/issue?@action=redirect&bpo=25738

   (18) https://bugs.python.org/issue?@action=redirect&bpo=21313

   (19) https://bugs.python.org/issue?@action=redirect&bpo=23883

   (20) https://bugs.python.org/issue?@action=redirect&bpo=27164

   (21) https://bugs.python.org/issue?@action=redirect&bpo=24291

   (22) https://bugs.python.org/issue?@action=redirect&bpo=21272

   (23) https://bugs.python.org/issue?@action=redirect&bpo=19611

   (24) https://bugs.python.org/issue?@action=redirect&bpo=26809

   (25) https://bugs.python.org/issue?@action=redirect&bpo=26373

   (26) https://bugs.python.org/issue?@action=redirect&bpo=27167

   (27) https://bugs.python.org/issue?@action=redirect&bpo=25931

   (28) https://bugs.python.org/issue?@action=redirect&bpo=21776

   (29) https://bugs.python.org/issue?@action=redirect&bpo=26526

   (30) https://bugs.python.org/issue?@action=redirect&bpo=27114

   (31) https://bugs.python.org/issue?@action=redirect&bpo=18383

   (32) https://bugs.python.org/issue?@action=redirect&bpo=23026

   (33) https://bugs.python.org/issue?@action=redirect&bpo=26741

   (34) https://bugs.python.org/issue?@action=redirect&bpo=27056

   (35) https://bugs.python.org/issue?@action=redirect&bpo=21271


File: python.info,  Node: IDLE<55>,  Next: Documentation<75>,  Prev: Library<187>,  Up: Python 3 6 0 alpha 2

1.24.95.4 IDLE
..............

   - bpo-5124(1): Paste with text selected now replaces the selection on
     X11.  This matches how paste works on Windows, Mac, most modern
     Linux apps, and ttk widgets.  Original patch by Serhiy Storchaka.

   - bpo-24750(2): Switch all scrollbars in IDLE to ttk versions.  Where
     needed, minimal tests are added to cover changes.

   - bpo-24759(3): IDLE requires tk 8.5 and availability ttk widgets.
     Delete now unneeded tk version tests and code for older versions.
     Add test for IDLE syntax colorizer.

   - bpo-27239(4): idlelib.macosx.isXyzTk functions initialize as
     needed.

   - bpo-27262(5): move Aqua unbinding code, which enable context menus,
     to macosx.

   - bpo-24759(6): Make clear in idlelib.idle_test.__init__ that the
     directory is a private implementation of test.test_idle and tool
     for maintainers.

   - bpo-27196(7): Stop “ThemeChanged” warnings when running IDLE tests.
     These persisted after other warnings were suppressed in #20567.
     Apply Serhiy Storchaka’s update_idletasks solution to four test
     files.  Record this additional advice in idle_test/README.txt

   - bpo-20567(8): Revise idle_test/README.txt with advice about
     avoiding tk warning messages from tests.  Apply advice to several
     IDLE tests.

   - bpo-24225(9): Update idlelib/README.txt with new file names and
     event handlers.

   - bpo-27156(10): Remove obsolete code not used by IDLE.

   - bpo-27117(11): Make colorizer htest and turtledemo work with dark
     themes.  Move code for configuring text widget colors to a new
     function.

   - bpo-24225(12): Rename many ‘idlelib/*.py’ and ‘idle_test/test_*.py’
     files.  Edit files to replace old names with new names when the old
     name referred to the module rather than the class it contained.
     See the issue and IDLE section in What’s New in 3.6 for more.

   - bpo-26673(13): When tk reports font size as 0, change to size 10.
     Such fonts on Linux prevented the configuration dialog from
     opening.

   - bpo-21939(14): Add test for IDLE’s percolator.  Original patch by
     Saimadhav Heblikar.

   - bpo-21676(15): Add test for IDLE’s replace dialog.  Original patch
     by Saimadhav Heblikar.

   - bpo-18410(16): Add test for IDLE’s search dialog.  Original patch
     by Westley Martínez.

   - bpo-21703(17): Add test for undo delegator.  Patch mostly by
     Saimadhav Heblikar .

   - bpo-27044(18): Add ConfigDialog.remove_var_callbacks to stop memory
     leaks.

   - bpo-23977(19): Add more asserts to test_delegator.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5124

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24750

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24759

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27239

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27262

   (6) https://bugs.python.org/issue?@action=redirect&bpo=24759

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27196

   (8) https://bugs.python.org/issue?@action=redirect&bpo=20567

   (9) https://bugs.python.org/issue?@action=redirect&bpo=24225

   (10) https://bugs.python.org/issue?@action=redirect&bpo=27156

   (11) https://bugs.python.org/issue?@action=redirect&bpo=27117

   (12) https://bugs.python.org/issue?@action=redirect&bpo=24225

   (13) https://bugs.python.org/issue?@action=redirect&bpo=26673

   (14) https://bugs.python.org/issue?@action=redirect&bpo=21939

   (15) https://bugs.python.org/issue?@action=redirect&bpo=21676

   (16) https://bugs.python.org/issue?@action=redirect&bpo=18410

   (17) https://bugs.python.org/issue?@action=redirect&bpo=21703

   (18) https://bugs.python.org/issue?@action=redirect&bpo=27044

   (19) https://bugs.python.org/issue?@action=redirect&bpo=23977


File: python.info,  Node: Documentation<75>,  Next: Tests<76>,  Prev: IDLE<55>,  Up: Python 3 6 0 alpha 2

1.24.95.5 Documentation
.......................

   - bpo-16484(1): Change the default PYTHONDOCS URL to «https:», and
     fix the resulting links to use lowercase.  Patch by Sean Rodman,
     test by Kaushik Nadikuditi.

   - bpo-24136(2): Document the new PEP 448(3) unpacking syntax of 3.5.

   - bpo-22558(4): Add remaining doc links to source code for
     Python-coded modules.  Patch by Yoni Lavi.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=16484

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24136

   (3) https://peps.python.org/pep-0448/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22558


File: python.info,  Node: Tests<76>,  Next: Windows<74>,  Prev: Documentation<75>,  Up: Python 3 6 0 alpha 2

1.24.95.6 Tests
...............

   - bpo-25285(1): regrtest now uses subprocesses when the -j1 command
     line option is used: each test file runs in a fresh child process.
     Before, the -j1 option was ignored.

   - bpo-25285(2): Tools/buildbot/test.bat script now uses -j1 by
     default to run each test file in fresh child process.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25285

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25285


File: python.info,  Node: Windows<74>,  Next: Build<87>,  Prev: Tests<76>,  Up: Python 3 6 0 alpha 2

1.24.95.7 Windows
.................

   - bpo-27064(1): The py.exe launcher now defaults to Python 3.  The
     Windows launcher ‘py.exe’ no longer prefers an installed Python 2
     version over Python 3 by default when used interactively.

   - bpo-17500(2): Remove unused and outdated icons.  (See also:
     ‘https://github.com/python/pythondotorg/issues/945’)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27064

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17500


File: python.info,  Node: Build<87>,  Next: C API<73>,  Prev: Windows<74>,  Up: Python 3 6 0 alpha 2

1.24.95.8 Build
...............

   - bpo-27229(1): Fix the cross-compiling pgen rule for in-tree builds.
     Patch by Xavier de Gaye.

   - bpo-26930(2): Update OS X 10.5+ 32-bit-only installer to build and
     link with OpenSSL 1.0.2h.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27229

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26930


File: python.info,  Node: C API<73>,  Next: Tools/Demos<53>,  Prev: Build<87>,  Up: Python 3 6 0 alpha 2

1.24.95.9 C API
...............

   - bpo-27186(1): Add the PyOS_FSPath() function (part of PEP 519(2)).

   - bpo-26282(3): PyArg_ParseTupleAndKeywords() now supports
     positional-only parameters.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27186

   (2) https://peps.python.org/pep-0519/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26282


File: python.info,  Node: Tools/Demos<53>,  Prev: C API<73>,  Up: Python 3 6 0 alpha 2

1.24.95.10 Tools/Demos
......................

   - bpo-26282(1): Argument Clinic now supports positional-only and
     keyword parameters in the same function.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26282


File: python.info,  Node: Python 3 6 0 alpha 1,  Next: Python 3 5 5 final,  Prev: Python 3 6 0 alpha 2,  Up: Changelog

1.24.96 Python 3.6.0 alpha 1
----------------------------

'Release date: 2016-05-16'

* Menu:

* Security: Security<56>.
* Core and Builtins: Core and Builtins<185>.
* Library: Library<188>.
* IDLE: IDLE<56>.
* Documentation: Documentation<76>.
* Tests: Tests<77>.
* Build: Build<88>.
* Windows: Windows<75>.
* Tools/Demos: Tools/Demos<54>.
* C API: C API<74>.


File: python.info,  Node: Security<56>,  Next: Core and Builtins<185>,  Up: Python 3 6 0 alpha 1

1.24.96.1 Security
..................

   - bpo-26657(1): Fix directory traversal vulnerability with
     http.server on Windows.  This fixes a regression that was
     introduced in 3.3.4rc1 and 3.4.0rc1.  Based on patch by Philipp
     Hagemeister.

   - bpo-26313(2): ssl.py _load_windows_store_certs fails if windows
     cert store is empty.  Patch by Baji.

   - bpo-25939(3): On Windows open the cert store readonly in
     ssl.enum_certificates.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26657

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26313

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25939


File: python.info,  Node: Core and Builtins<185>,  Next: Library<188>,  Prev: Security<56>,  Up: Python 3 6 0 alpha 1

1.24.96.2 Core and Builtins
...........................

   - bpo-20041(1): Fixed TypeError when frame.f_trace is set to None.
     Patch by Xavier de Gaye.

   - bpo-26168(2): Fixed possible refleaks in failing Py_BuildValue()
     with the «N» format unit.

   - bpo-26991(3): Fix possible refleak when creating a function with
     annotations.

   - bpo-27039(4): Fixed bytearray.remove() for values greater than 127.
     Based on patch by Joe Jevnik.

   - bpo-23640(5): int.from_bytes() no longer bypasses constructors for
     subclasses.

   - bpo-27005(6): Optimized the float.fromhex() class method for exact
     float.  It is now 2 times faster.

   - bpo-18531(7): Single var-keyword argument of dict subtype was
     passed unscathed to the C-defined function.  Now it is converted to
     exact dict.

   - bpo-26811(8): gc.get_objects() no longer contains a broken tuple
     with NULL pointer.

   - bpo-20120(9): Use RawConfigParser for .pypirc parsing, removing
     support for interpolation unintentionally added with move to Python
     3.  Behavior no longer does any interpolation in .pypirc files,
     matching behavior in Python 2.7 and Setuptools 19.0.

   - bpo-26249(10): Memory functions of the *note PyMem_Malloc(): e62.
     domain (*note PYMEM_DOMAIN_MEM: e65.) now use the *note pymalloc
     allocator: f0d. rather than system ‘malloc()’.  Applications
     calling *note PyMem_Malloc(): e62. without holding the GIL can now
     crash: use ‘PYTHONMALLOC=debug’ environment variable to validate
     the usage of memory allocators in your application.

   - bpo-26802(11): Optimize function calls only using unpacking like
     ‘func(*tuple)’ (no other positional argument, no keyword): avoid
     copying the tuple.  Patch written by Joe Jevnik.

   - bpo-26659(12): Make the builtin slice type support cycle
     collection.

   - bpo-26718(13): super.__init__ no longer leaks memory if called
     multiple times.  NOTE: A direct call of super.__init__ is not
     endorsed!

   - bpo-27138(14): Fix the doc comment for FileFinder.find_spec().

   - bpo-27147(15): Mention PEP 420(16) in the importlib docs.

   - bpo-25339(17): PYTHONIOENCODING now has priority over locale in
     setting the error handler for stdin and stdout.

   - bpo-26494(18): Fixed crash on iterating exhausting iterators.
     Affected classes are generic sequence iterators, iterators of str,
     bytes, bytearray, list, tuple, set, frozenset, dict, OrderedDict,
     corresponding views and os.scandir() iterator.

   - bpo-26574(19): Optimize ‘bytes.replace(b'', b'.')’ and
     ‘bytearray.replace(b'', b'.')’.  Patch written by Josh Snider.

   - bpo-26581(20): If coding cookie is specified multiple times on a
     line in Python source code file, only the first one is taken to
     account.

   - bpo-19711(21): Add tests for reloading namespace packages.

   - bpo-21099(22): Switch applicable importlib tests to use PEP 451(23)
     API.

   - bpo-26563(24): Debug hooks on Python memory allocators now raise a
     fatal error if functions of the *note PyMem_Malloc(): e62. family
     are called without holding the GIL.

   - bpo-26564(25): On error, the debug hooks on Python memory
     allocators now use the *note tracemalloc: 105. module to get the
     traceback where a memory block was allocated.

   - bpo-26558(26): The debug hooks on Python memory allocator *note
     PyObject_Malloc(): e64. now detect when functions are called
     without holding the GIL.

   - bpo-26516(27): Add *note PYTHONMALLOC: e60. environment variable to
     set the Python memory allocators and/or install debug hooks.

   - bpo-26516(28): The *note PyMem_SetupDebugHooks(): e66. function can
     now also be used on Python compiled in release mode.

   - bpo-26516(29): The *note PYTHONMALLOCSTATS: 1f1f. environment
     variable can now also be used on Python compiled in release mode.
     It now has no effect if set to an empty string.

   - bpo-26516(30): In debug mode, debug hooks are now also installed on
     Python memory allocators when Python is configured without
     pymalloc.

   - bpo-26464(31): Fix str.translate() when string is ASCII and first
     replacements removes character, but next replacement uses a
     non-ASCII character or a string longer than 1 character.
     Regression introduced in Python 3.5.0.

   - bpo-22836(32): Ensure exception reports from PyErr_Display() and
     PyErr_WriteUnraisable() are sensible even when formatting them
     produces secondary errors.  This affects the reports produced by
     sys.__excepthook__() and when __del__() raises an exception.

   - bpo-26302(33): Correct behavior to reject comma as a legal
     character for cookie names.

   - bpo-26136(34): Upgrade the warning when a generator raises
     StopIteration from PendingDeprecationWarning to DeprecationWarning.
     Patch by Anish Shah.

   - bpo-26204(35): The compiler now ignores all constant statements:
     bytes, str, int, float, complex, name constants (None, False,
     True), Ellipsis and ast.Constant; not only str and int.  For
     example, ‘1.0’ is now ignored in ‘def f(): 1.0’.

   - bpo-4806(36): Avoid masking the original TypeError exception when
     using star (‘*’) unpacking in function calls.  Based on patch by
     Hagen Fürstenau and Daniel Urban.

   - bpo-26146(37): Add a new kind of AST node: ‘ast.Constant’.  It can
     be used by external AST optimizers, but the compiler does not emit
     directly such node.

   - bpo-23601(38): Sped-up allocation of dict key objects by using
     Python’s small object allocator.  (Contributed by Julian Taylor.)

   - bpo-18018(39): Import raises ImportError instead of SystemError if
     a relative import is attempted without a known parent package.

   - bpo-25843(40): When compiling code, don’t merge constants if they
     are equal but have a different types.  For example, ‘f1, f2 =
     lambda: 1, lambda: 1.0’ is now correctly compiled to two different
     functions: ‘f1()’ returns ‘1’ (‘int’) and ‘f2()’ returns ‘1.0’
     (‘float’), even if ‘1’ and ‘1.0’ are equal.

   - bpo-26107(41): The format of the ‘co_lnotab’ attribute of code
     objects changes to support negative line number delta.

   - bpo-26154(42): Add a new private _PyThreadState_UncheckedGet()
     function to get the current Python thread state, but don’t issue a
     fatal error if it is NULL. This new function must be used instead
     of accessing directly the _PyThreadState_Current variable.  The
     variable is no more exposed since Python 3.5.1 to hide the exact
     implementation of atomic C types, to avoid compiler issues.

   - bpo-25791(43): If __package__ != __spec__.parent or if neither
     __package__ or __spec__ are defined then ImportWarning is raised.

   - bpo-22995(44): [UPDATE] Comment out the one of the pickleability
     tests in _PyObject_GetState() due to regressions observed in
     Cython-based projects.

   - bpo-25961(45): Disallowed null characters in the type name.

   - bpo-25973(46): Fix segfault when an invalid nonlocal statement
     binds a name starting with two underscores.

   - bpo-22995(47): Instances of extension types with a state that
     aren’t subclasses of list or dict and haven’t implemented any
     pickle-related methods (__reduce__, __reduce_ex__, __getnewargs__,
     __getnewargs_ex__, or __getstate__), can no longer be pickled.
     Including memoryview.

   - bpo-20440(48): Massive replacing unsafe attribute setting code with
     special macro Py_SETREF.

   - bpo-25766(49): Special method __bytes__() now works in str
     subclasses.

   - bpo-25421(50): __sizeof__ methods of builtin types now use dynamic
     basic size.  This allows sys.getsize() to work correctly with their
     subclasses with __slots__ defined.

   - bpo-25709(51): Fixed problem with in-place string concatenation and
     utf-8 cache.

   - bpo-5319(52): New Py_FinalizeEx() API allowing Python to set an
     exit status of 120 on failure to flush buffered streams.

   - bpo-25485(53): telnetlib.Telnet is now a context manager.

   - bpo-24097(54): Fixed crash in object.__reduce__() if slot name is
     freed inside __getattr__.

   - bpo-24731(55): Fixed crash on converting objects with special
     methods __bytes__, __trunc__, and __float__ returning instances of
     subclasses of bytes, int, and float to subclasses of bytes, int,
     and float correspondingly.

   - bpo-25630(56): Fix a possible segfault during argument parsing in
     functions that accept filesystem paths.

   - bpo-23564(57): Fixed a partially broken sanity check in the
     _posixsubprocess internals regarding how fds_to_pass were passed to
     the child.  The bug had no actual impact as subprocess.py already
     avoided it.

   - bpo-25388(58): Fixed tokenizer crash when processing undecodable
     source code with a null byte.

   - bpo-25462(59): The hash of the key now is calculated only once in
     most operations in C implementation of OrderedDict.

   - bpo-22995(60): Default implementation of __reduce__ and
     __reduce_ex__ now rejects builtin types with not defined __new__.

   - bpo-24802(61): Avoid buffer overreads when int(), float(),
     compile(), exec() and eval() are passed bytes-like objects.  These
     objects are not necessarily terminated by a null byte, but the
     functions assumed they were.

   - bpo-25555(62): Fix parser and AST: fill lineno and col_offset of
     «arg» node when compiling AST from Python objects.

   - bpo-24726(63): Fixed a crash and leaking NULL in repr() of
     OrderedDict that was mutated by direct calls of dict methods.

   - bpo-25449(64): Iterating OrderedDict with keys with unstable hash
     now raises KeyError in C implementations as well as in Python
     implementation.

   - bpo-25395(65): Fixed crash when highly nested OrderedDict
     structures were garbage collected.

   - bpo-25401(66): Optimize bytes.fromhex() and bytearray.fromhex():
     they are now between 2x and 3.5x faster.

   - bpo-25399(67): Optimize bytearray % args using the new private
     _PyBytesWriter API. Formatting is now between 2.5 and 5 times
     faster.

   - bpo-25274(68): sys.setrecursionlimit() now raises a RecursionError
     if the new recursion limit is too low depending at the current
     recursion depth.  Modify also the «lower-water mark» formula to
     make it monotonic.  This mark is used to decide when the overflowed
     flag of the thread state is reset.

   - bpo-24402(69): Fix input() to prompt to the redirected stdout when
     sys.stdout.fileno() fails.

   - bpo-25349(70): Optimize bytes % args using the new private
     _PyBytesWriter API. Formatting is now up to 2 times faster.

   - bpo-24806(71): Prevent builtin types that are not allowed to be
     subclassed from being subclassed through multiple inheritance.

   - bpo-25301(72): The UTF-8 decoder is now up to 15 times as fast for
     error handlers: ‘ignore’, ‘replace’ and ‘surrogateescape’.

   - bpo-24848(73): Fixed a number of bugs in UTF-7 decoding of
     misformed data.

   - bpo-25267(74): The UTF-8 encoder is now up to 75 times as fast for
     error handlers: ‘ignore’, ‘replace’, ‘surrogateescape’,
     ‘surrogatepass’.  Patch co-written with Serhiy Storchaka.

   - bpo-25280(75): Import trace messages emitted in verbose (-v) mode
     are no longer formatted twice.

   - bpo-25227(76): Optimize ASCII and latin1 encoders with the
     ‘surrogateescape’ error handler: the encoders are now up to 3 times
     as fast.  Initial patch written by Serhiy Storchaka.

   - bpo-25003(77): On Solaris 11.3 or newer, os.urandom() now uses the
     getrandom() function instead of the getentropy() function.  The
     getentropy() function is blocking to generate very good quality
     entropy, os.urandom() doesn’t need such high-quality entropy.

   - bpo-9232(78): Modify Python’s grammar to allow trailing commas in
     the argument list of a function declaration.  For example, «def
     f(*, a = 3,): pass» is now legal.  Patch from Mark Dickinson.

   - bpo-24965(79): Implement PEP 498(80) «Literal String
     Interpolation».  This allows you to embed expressions inside
     f-strings, which are converted to normal strings at run time.
     Given x=3, then f’value={x}” == “value=3”.  Patch by Eric V. Smith.

   - bpo-26478(81): Fix semantic bugs when using binary operators with
     dictionary views and tuples.

   - bpo-26171(82): Fix possible integer overflow and heap corruption in
     zipimporter.get_data().

   - bpo-25660(83): Fix TAB key behaviour in REPL with readline.

   - bpo-26288(84): Optimize PyLong_AsDouble.

   - bpo-26289(85): Optimize floor and modulo division for single-digit
     longs.  Microbenchmarks show 2-2.5x improvement.  Built-in “divmod”
     function is now also ~10% faster.  (See also: bpo-26315(86))

   - bpo-25887(87): Raise a RuntimeError when a coroutine object is
     awaited more than once.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20041

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26168

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26991

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27039

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23640

   (6) https://bugs.python.org/issue?@action=redirect&bpo=27005

   (7) https://bugs.python.org/issue?@action=redirect&bpo=18531

   (8) https://bugs.python.org/issue?@action=redirect&bpo=26811

   (9) https://bugs.python.org/issue?@action=redirect&bpo=20120

   (10) https://bugs.python.org/issue?@action=redirect&bpo=26249

   (11) https://bugs.python.org/issue?@action=redirect&bpo=26802

   (12) https://bugs.python.org/issue?@action=redirect&bpo=26659

   (13) https://bugs.python.org/issue?@action=redirect&bpo=26718

   (14) https://bugs.python.org/issue?@action=redirect&bpo=27138

   (15) https://bugs.python.org/issue?@action=redirect&bpo=27147

   (16) https://peps.python.org/pep-0420/

   (17) https://bugs.python.org/issue?@action=redirect&bpo=25339

   (18) https://bugs.python.org/issue?@action=redirect&bpo=26494

   (19) https://bugs.python.org/issue?@action=redirect&bpo=26574

   (20) https://bugs.python.org/issue?@action=redirect&bpo=26581

   (21) https://bugs.python.org/issue?@action=redirect&bpo=19711

   (22) https://bugs.python.org/issue?@action=redirect&bpo=21099

   (23) https://peps.python.org/pep-0451/

   (24) https://bugs.python.org/issue?@action=redirect&bpo=26563

   (25) https://bugs.python.org/issue?@action=redirect&bpo=26564

   (26) https://bugs.python.org/issue?@action=redirect&bpo=26558

   (27) https://bugs.python.org/issue?@action=redirect&bpo=26516

   (28) https://bugs.python.org/issue?@action=redirect&bpo=26516

   (29) https://bugs.python.org/issue?@action=redirect&bpo=26516

   (30) https://bugs.python.org/issue?@action=redirect&bpo=26516

   (31) https://bugs.python.org/issue?@action=redirect&bpo=26464

   (32) https://bugs.python.org/issue?@action=redirect&bpo=22836

   (33) https://bugs.python.org/issue?@action=redirect&bpo=26302

   (34) https://bugs.python.org/issue?@action=redirect&bpo=26136

   (35) https://bugs.python.org/issue?@action=redirect&bpo=26204

   (36) https://bugs.python.org/issue?@action=redirect&bpo=4806

   (37) https://bugs.python.org/issue?@action=redirect&bpo=26146

   (38) https://bugs.python.org/issue?@action=redirect&bpo=23601

   (39) https://bugs.python.org/issue?@action=redirect&bpo=18018

   (40) https://bugs.python.org/issue?@action=redirect&bpo=25843

   (41) https://bugs.python.org/issue?@action=redirect&bpo=26107

   (42) https://bugs.python.org/issue?@action=redirect&bpo=26154

   (43) https://bugs.python.org/issue?@action=redirect&bpo=25791

   (44) https://bugs.python.org/issue?@action=redirect&bpo=22995

   (45) https://bugs.python.org/issue?@action=redirect&bpo=25961

   (46) https://bugs.python.org/issue?@action=redirect&bpo=25973

   (47) https://bugs.python.org/issue?@action=redirect&bpo=22995

   (48) https://bugs.python.org/issue?@action=redirect&bpo=20440

   (49) https://bugs.python.org/issue?@action=redirect&bpo=25766

   (50) https://bugs.python.org/issue?@action=redirect&bpo=25421

   (51) https://bugs.python.org/issue?@action=redirect&bpo=25709

   (52) https://bugs.python.org/issue?@action=redirect&bpo=5319

   (53) https://bugs.python.org/issue?@action=redirect&bpo=25485

   (54) https://bugs.python.org/issue?@action=redirect&bpo=24097

   (55) https://bugs.python.org/issue?@action=redirect&bpo=24731

   (56) https://bugs.python.org/issue?@action=redirect&bpo=25630

   (57) https://bugs.python.org/issue?@action=redirect&bpo=23564

   (58) https://bugs.python.org/issue?@action=redirect&bpo=25388

   (59) https://bugs.python.org/issue?@action=redirect&bpo=25462

   (60) https://bugs.python.org/issue?@action=redirect&bpo=22995

   (61) https://bugs.python.org/issue?@action=redirect&bpo=24802

   (62) https://bugs.python.org/issue?@action=redirect&bpo=25555

   (63) https://bugs.python.org/issue?@action=redirect&bpo=24726

   (64) https://bugs.python.org/issue?@action=redirect&bpo=25449

   (65) https://bugs.python.org/issue?@action=redirect&bpo=25395

   (66) https://bugs.python.org/issue?@action=redirect&bpo=25401

   (67) https://bugs.python.org/issue?@action=redirect&bpo=25399

   (68) https://bugs.python.org/issue?@action=redirect&bpo=25274

   (69) https://bugs.python.org/issue?@action=redirect&bpo=24402

   (70) https://bugs.python.org/issue?@action=redirect&bpo=25349

   (71) https://bugs.python.org/issue?@action=redirect&bpo=24806

   (72) https://bugs.python.org/issue?@action=redirect&bpo=25301

   (73) https://bugs.python.org/issue?@action=redirect&bpo=24848

   (74) https://bugs.python.org/issue?@action=redirect&bpo=25267

   (75) https://bugs.python.org/issue?@action=redirect&bpo=25280

   (76) https://bugs.python.org/issue?@action=redirect&bpo=25227

   (77) https://bugs.python.org/issue?@action=redirect&bpo=25003

   (78) https://bugs.python.org/issue?@action=redirect&bpo=9232

   (79) https://bugs.python.org/issue?@action=redirect&bpo=24965

   (80) https://peps.python.org/pep-0498/

   (81) https://bugs.python.org/issue?@action=redirect&bpo=26478

   (82) https://bugs.python.org/issue?@action=redirect&bpo=26171

   (83) https://bugs.python.org/issue?@action=redirect&bpo=25660

   (84) https://bugs.python.org/issue?@action=redirect&bpo=26288

   (85) https://bugs.python.org/issue?@action=redirect&bpo=26289

   (86) https://bugs.python.org/issue?@action=redirect&bpo=26315

   (87) https://bugs.python.org/issue?@action=redirect&bpo=25887


File: python.info,  Node: Library<188>,  Next: IDLE<56>,  Prev: Core and Builtins<185>,  Up: Python 3 6 0 alpha 1

1.24.96.3 Library
.................

   - bpo-27057(1): Fix os.set_inheritable() on Android, ioctl() is
     blocked by SELinux and fails with EACCESS. The function now falls
     back to fcntl().  Patch written by Michał Bednarski.

   - bpo-27014(2): Fix infinite recursion using typing.py.  Thanks to
     Kalle Tuure!

   - bpo-27031(3): Removed dummy methods in Tkinter widget classes:
     tk_menuBar() and tk_bindForTraversal().

   - bpo-14132(4): Fix urllib.request redirect handling when the target
     only has a query string.  Original fix by Ján Janech.

   - bpo-17214(5): The «urllib.request» module now percent-encodes
     non-ASCII bytes found in redirect target URLs.  Some servers send
     Location header fields with non-ASCII bytes, but «http.client»
     requires the request target to be ASCII-encodable, otherwise a
     UnicodeEncodeError is raised.  Based on patch by Christian Heimes.

   - bpo-27033(6): The default value of the decode_data parameter for
     smtpd.SMTPChannel and smtpd.SMTPServer constructors is changed to
     False.

   - bpo-27034(7): Removed deprecated class asynchat.fifo.

   - bpo-26870(8): Added readline.set_auto_history(), which can stop
     entries being automatically added to the history list.  Based on
     patch by Tyler Crompton.

   - bpo-26039(9): zipfile.ZipFile.open() can now be used to write data
     into a ZIP file, as well as for extracting data.  Patch by Thomas
     Kluyver.

   - bpo-26892(10): Honor debuglevel flag in urllib.request.HTTPHandler.
     Patch contributed by Chi Hsuan Yen.

   - bpo-22274(11): In the subprocess module, allow stderr to be
     redirected to stdout even when stdout is not redirected.  Patch by
     Akira Li.

   - bpo-26807(12): mock_open “files” no longer error on readline at end
     of file.  Patch from Yolanda Robla.

   - bpo-25745(13): Fixed leaking a userptr in curses panel destructor.

   - bpo-26977(14): Removed unnecessary, and ignored, call to sum of
     squares helper in statistics.pvariance.

   - bpo-26002(15): Use bisect in statistics.median instead of a linear
     search.  Patch by Upendra Kuma.

   - bpo-25974(16): Make use of new Decimal.as_integer_ratio() method in
     statistics module.  Patch by Stefan Krah.

   - bpo-26996(17): Add secrets module as described in PEP 506(18).

   - bpo-26881(19): The modulefinder module now supports extended opcode
     arguments.

   - bpo-23815(20): Fixed crashes related to directly created instances
     of types in _tkinter and curses.panel modules.

   - bpo-17765(21): weakref.ref() no longer silently ignores keyword
     arguments.  Patch by Georg Brandl.

   - bpo-26873(22): xmlrpc now raises ResponseError on unsupported type
     tags instead of silently return incorrect result.

   - bpo-26915(23): The __contains__ methods in the collections ABCs now
     check for identity before checking equality.  This better matches
     the behavior of the concrete classes, allows sensible handling of
     NaNs, and makes it easier to reason about container invariants.

   - bpo-26711(24): Fixed the comparison of plistlib.Data with other
     types.

   - bpo-24114(25): Fix an uninitialized variable in ‘ctypes.util’.  The
     bug only occurs on SunOS when the ctypes implementation searches
     for the ‘crle’ program.  Patch by Xiang Zhang.  Tested on SunOS by
     Kees Bos.

   - bpo-26864(26): In urllib.request, change the proxy bypass host
     checking against no_proxy to be case-insensitive, and to not match
     unrelated host names that happen to have a bypassed hostname as a
     suffix.  Patch by Xiang Zhang.

   - bpo-24902(27): Print server URL on http.server startup.  Initial
     patch by Felix Kaiser.

   - bpo-25788(28): fileinput.hook_encoded() now supports an «errors»
     argument for passing to open.  Original patch by Joseph Hackman.

   - bpo-26634(29): recursive_repr() now sets __qualname__ of wrapper.
     Patch by Xiang Zhang.

   - bpo-26804(30): urllib.request will prefer lower_case proxy
     environment variables over UPPER_CASE or Mixed_Case ones.  Patch
     contributed by Hans-Peter Jansen.

   - bpo-26837(31): assertSequenceEqual() now correctly outputs
     non-stringified differing items (like bytes in the -b mode).  This
     affects assertListEqual() and assertTupleEqual().

   - bpo-26041(32): Remove «will be removed in Python 3.7» from
     deprecation messages of platform.dist() and
     platform.linux_distribution().  Patch by Kumaripaba Miyurusara
     Athukorala.

   - bpo-26822(33): itemgetter, attrgetter and methodcaller objects no
     longer silently ignore keyword arguments.

   - bpo-26733(34): Disassembling a class now disassembles class and
     static methods.  Patch by Xiang Zhang.

   - bpo-26801(35): Fix error handling in *note
     shutil.get_terminal_size(): 130b, catch *note AttributeError: 5f0.
     instead of *note NameError: 452.  Patch written by Emanuel Barry.

   - bpo-24838(36): tarfile’s ustar and gnu formats now correctly
     calculate name and link field limits for multibyte character
     encodings like utf-8.

   - bpo-26717(37): Stop encoding Latin-1-ized WSGI paths with UTF-8.
     Patch by Anthony Sottile.

   - bpo-26782(38): Add STARTUPINFO to subprocess.__all__ on Windows.

   - bpo-26404(39): Add context manager to socketserver.  Patch by Aviv
     Palivoda.

   - bpo-26735(40): Fix *note os.urandom(): 747. on Solaris 11.3 and
     newer when reading more than 1,024 bytes: call ‘getrandom()’
     multiple times with a limit of 1024 bytes per call.

   - bpo-26585(41): Eliminate http.server._quote_html() and use
     html.escape(quote=False).  Patch by Xiang Zhang.

   - bpo-26685(42): Raise OSError if closing a socket fails.

   - bpo-16329(43): Add .webm to mimetypes.types_map.  Patch by
     Giampaolo Rodola”.

   - bpo-13952(44): Add .csv to mimetypes.types_map.  Patch by Geoff
     Wilson.

   - bpo-26587(45): the site module now allows .pth files to specify
     files to be added to sys.path (e.g.  zip files).

   - bpo-25609(46): Introduce contextlib.AbstractContextManager and
     typing.ContextManager.

   - bpo-26709(47): Fixed Y2038 problem in loading binary PLists.

   - bpo-23735(48): Handle terminal resizing with Readline 6.3+ by
     installing our own SIGWINCH handler.  Patch by Eric Price.

   - bpo-25951(49): Change SSLSocket.sendall() to return None, as
     explicitly documented for plain socket objects.  Patch by Aviv
     Palivoda.

   - bpo-26586(50): In http.server, respond with «413 Request header
     fields too large» if there are too many header fields to parse,
     rather than killing the connection and raising an unhandled
     exception.  Patch by Xiang Zhang.

   - bpo-26676(51): Added missing XMLPullParser to ElementTree.__all__.

   - bpo-22854(52): Change BufferedReader.writable() and
     BufferedWriter.readable() to always return False.

   - bpo-26492(53): Exhausted iterator of array.array now conforms with
     the behavior of iterators of other mutable sequences: it lefts
     exhausted even if iterated array is extended.

   - bpo-26641(54): doctest.DocFileTest and doctest.testfile() now
     support packages (module split into multiple directories) for the
     package parameter.

   - bpo-25195(55): Fix a regression in mock.MagicMock.  _Call is a
     subclass of tuple (changeset 3603bae63c13 only works for classes)
     so we need to implement __ne__ ourselves.  Patch by Andrew Plummer.

   - bpo-26644(56): Raise ValueError rather than SystemError when a
     negative length is passed to SSLSocket.recv() or read().

   - bpo-23804(57): Fix SSL recv(0) and read(0) methods to return zero
     bytes instead of up to 1024.

   - bpo-26616(58): Fixed a bug in datetime.astimezone() method.

   - bpo-26637(59): The *note importlib: 7b. module now emits an *note
     ImportError: 65b. rather than a *note TypeError: 198. if *note
     __import__(): ad3. is tried during the Python shutdown process but
     *note sys.path: 3e4. is already cleared (set to ‘None’).

   - bpo-21925(60): *note warnings.formatwarning(): 1de0. now catches
     exceptions when calling *note linecache.getline(): 240. and *note
     tracemalloc.get_object_traceback(): 1f21. to be able to log *note
     ResourceWarning: 54d. emitted late during the Python shutdown
     process.

   - bpo-23848(61): On Windows, faulthandler.enable() now also installs
     an exception handler to dump the traceback of all Python threads on
     any Windows exception, not only on UNIX signals (SIGSEGV, SIGFPE,
     SIGABRT).

   - bpo-26530(62): Add C functions ‘_PyTraceMalloc_Track()’ and
     ‘_PyTraceMalloc_Untrack()’ to track memory blocks using the *note
     tracemalloc: 105. module.  Add ‘_PyTraceMalloc_GetTraceback()’ to
     get the traceback of an object.

   - bpo-26588(63): The _tracemalloc now supports tracing memory
     allocations of multiple address spaces (domains).

   - bpo-24266(64): Ctrl+C during Readline history search now cancels
     the search mode when compiled with Readline 7.

   - bpo-26590(65): Implement a safe finalizer for the _socket.socket
     type.  It now releases the GIL to close the socket.

   - bpo-18787(66): spwd.getspnam() now raises a PermissionError if the
     user doesn’t have privileges.

   - bpo-26560(67): Avoid potential ValueError in
     BaseHandler.start_response.  Initial patch by Peter Inglesby.

   - bpo-26567(68): Add a new function *note PyErr_ResourceWarning():
     f15. function to pass the destroyed object.  Add a 'source'
     attribute to ‘warnings.WarningMessage’.  Add
     warnings._showwarnmsg() which uses tracemalloc to get the traceback
     where source object was allocated.

   - bpo-26569(69): Fix *note pyclbr.readmodule(): a2e. and *note
     pyclbr.readmodule_ex(): a2f. to support importing packages.

   - bpo-26499(70): Account for remaining Content-Length in
     HTTPResponse.readline() and read1().  Based on patch by Silent
     Ghost.  Also document that HTTPResponse now supports these methods.

   - bpo-25320(71): Handle sockets in directories unittest discovery is
     scanning.  Patch from Victor van den Elzen.

   - bpo-16181(72): cookiejar.http2time() now returns None if year is
     higher than datetime.MAXYEAR.

   - bpo-26513(73): Fixes platform module detection of Windows Server

   - bpo-23718(74): Fixed parsing time in week 0 before Jan 1.  Original
     patch by Tamás Bence Gedai.

   - bpo-26323(75): Add Mock.assert_called() and
     Mock.assert_called_once() methods to unittest.mock.  Patch written
     by Amit Saha.

   - bpo-20589(76): Invoking Path.owner() and Path.group() on Windows
     now raise NotImplementedError instead of ImportError.

   - bpo-26177(77): Fixed the keys() method for Canvas and Scrollbar
     widgets.

   - bpo-15068(78): Got rid of excessive buffering in fileinput.  The
     bufsize parameter is now deprecated and ignored.

   - bpo-19475(79): Added an optional argument timespec to the datetime
     isoformat() method to choose the precision of the time component.

   - bpo-2202(80): Fix UnboundLocalError in
     AbstractDigestAuthHandler.get_algorithm_impls.  Initial patch by
     Mathieu Dupuy.

   - bpo-26167(81): Minimized overhead in copy.copy() and
     copy.deepcopy().  Optimized copying and deepcopying bytearrays,
     NotImplemented, slices, short lists, tuples, dicts, sets.

   - bpo-25718(82): Fixed pickling and copying the accumulate() iterator
     with total is None.

   - bpo-26475(83): Fixed debugging output for regular expressions with
     the (?x) flag.

   - bpo-26482(84): Allowed pickling recursive dequeues.

   - bpo-26335(85): Make mmap.write() return the number of bytes written
     like other write methods.  Patch by Jakub Stasiak.

   - bpo-26457(86): Fixed the subnets() methods in IP network classes
     for the case when resulting prefix length is equal to maximal
     prefix length.  Based on patch by Xiang Zhang.

   - bpo-26385(87): Remove the file if the internal open() call in
     NamedTemporaryFile() fails.  Patch by Silent Ghost.

   - bpo-26402(88): Fix XML-RPC client to retry when the server shuts
     down a persistent connection.  This was a regression related to the
     new http.client.RemoteDisconnected exception in 3.5.0a4.

   - bpo-25913(89): Leading ‘<~’ is optional now in base64.a85decode()
     with adobe=True.  Patch by Swati Jaiswal.

   - bpo-26186(90): Remove an invalid type check in
     importlib.util.LazyLoader.

   - bpo-26367(91): importlib.__import__() raises ImportError like
     builtins.__import__() when ‘level’ is specified but without an
     accompanying package specified.

   - bpo-26309(92): In the «socketserver» module, shut down the request
     (closing the connected socket) when verify_request() returns false.
     Patch by Aviv Palivoda.

   - bpo-23430(93): Change the socketserver module to only catch
     exceptions raised from a request handler that are derived from
     Exception (instead of BaseException).  Therefore SystemExit and
     KeyboardInterrupt no longer trigger the handle_error() method, and
     will now to stop a single-threaded server.

   - bpo-25995(94): os.walk() no longer uses FDs proportional to the
     tree depth.

   - bpo-25994(95): Added the close() method and the support of the
     context manager protocol for the os.scandir() iterator.

   - bpo-23992(96): multiprocessing: make MapResult not fail-fast upon
     exception.

   - bpo-26243(97): Support keyword arguments to zlib.compress().  Patch
     by Aviv Palivoda.

   - bpo-26117(98): The os.scandir() iterator now closes file descriptor
     not only when the iteration is finished, but when it was failed
     with error.

   - bpo-25949(99): __dict__ for an OrderedDict instance is now created
     only when needed.

   - bpo-25911(100): Restored support of bytes paths in os.walk() on
     Windows.

   - bpo-26045(101): Add UTF-8 suggestion to error message when posting
     a non-Latin-1 string with http.client.

   - bpo-26039(102): Added zipfile.ZipInfo.from_file() and
     zipinfo.ZipInfo.is_dir().  Patch by Thomas Kluyver.

   - bpo-12923(103): Reset FancyURLopener’s redirect counter even if
     there is an exception.  Based on patches by Brian Brazil and Daniel
     Rocco.

   - bpo-25945(104): Fixed a crash when unpickle the functools.partial
     object with wrong state.  Fixed a leak in failed functools.partial
     constructor.  «args» and «keywords» attributes of functools.partial
     have now always types tuple and dict correspondingly.

   - bpo-26202(105): copy.deepcopy() now correctly copies range()
     objects with non-atomic attributes.

   - bpo-23076(106): Path.glob() now raises a ValueError if it’s called
     with an invalid pattern.  Patch by Thomas Nyberg.

   - bpo-19883(107): Fixed possible integer overflows in zipimport.

   - bpo-26227(108): On Windows, getnameinfo(), gethostbyaddr() and
     gethostbyname_ex() functions of the socket module now decode the
     hostname from the ANSI code page rather than UTF-8.

   - bpo-26099(109): The site module now writes an error into stderr if
     sitecustomize module can be imported but executing the module raise
     an ImportError.  Same change for usercustomize.

   - bpo-26147(110): xmlrpc now works with strings not encodable with
     used non-UTF-8 encoding.

   - bpo-25935(111): Garbage collector now breaks reference loops with
     OrderedDict.

   - bpo-16620(112): Fixed AttributeError in msilib.Directory.glob().

   - bpo-26013(113): Added compatibility with broken protocol 2 pickles
     created in old Python 3 versions (3.4.3 and lower).

   - bpo-26129(114): Deprecated accepting non-integers in
     grp.getgrgid().

   - bpo-25850(115): Use cross-compilation by default for 64-bit
     Windows.

   - bpo-25822(116): Add docstrings to the fields of urllib.parse
     results.  Patch contributed by Swati Jaiswal.

   - bpo-22642(117): Convert trace module option parsing mechanism to
     argparse.  Patch contributed by SilentGhost.

   - bpo-24705(118): Fix sysconfig._parse_makefile not expanding ${}
     vars appearing before $() vars.

   - bpo-26069(119): Remove the deprecated apis in the trace module.

   - bpo-22138(120): Fix mock.patch behavior when patching descriptors.
     Restore original values after patching.  Patch contributed by Sean
     McCully.

   - bpo-25672(121): In the ssl module, enable the
     SSL_MODE_RELEASE_BUFFERS mode option if it is safe to do so.

   - bpo-26012(122): Don’t traverse into symlinks for ‘**’ pattern in
     pathlib.Path.[r]glob().

   - bpo-24120(123): Ignore PermissionError when traversing a tree with
     pathlib.Path.[r]glob().  Patch by Ulrich Petri.

   - bpo-21815(124): Accept ] characters in the data portion of imap
     responses, in order to handle the flags with square brackets
     accepted and produced by servers such as gmail.

   - bpo-25447(125): fileinput now uses sys.stdin as-is if it does not
     have a buffer attribute (restores backward compatibility).

   - bpo-25971(126): Optimized creating Fractions from floats by 2 times
     and from Decimals by 3 times.

   - bpo-25802(127): Document as deprecated the remaining
     implementations of importlib.abc.Loader.load_module().

   - bpo-25928(128): Add Decimal.as_integer_ratio().

   - bpo-25447(129): Copying the lru_cache() wrapper object now always
     works, independently from the type of the wrapped object (by
     returning the original object unchanged).

   - bpo-25768(130): Have the functions in compileall return booleans
     instead of ints and add proper documentation and tests for the
     return values.

   - bpo-24103(131): Fixed possible use after free in
     ElementTree.XMLPullParser.

   - bpo-25860(132): os.fwalk() no longer skips remaining directories
     when error occurs.  Original patch by Samson Lee.

   - bpo-25914(133): Fixed and simplified OrderedDict.__sizeof__.

   - bpo-25869(134): Optimized deepcopying ElementTree; it is now 20
     times faster.

   - bpo-25873(135): Optimized iterating ElementTree.  Iterating
     elements Element.iter() is now 40% faster, iterating text
     Element.itertext() is now up to 2.5 times faster.

   - bpo-25902(136): Fixed various refcount issues in ElementTree
     iteration.

   - bpo-22227(137): The TarFile iterator is reimplemented using
     generator.  This implementation is simpler that using class.

   - bpo-25638(138): Optimized ElementTree.iterparse(); it is now 2x
     faster.  Optimized ElementTree parsing; it is now 10% faster.

   - bpo-25761(139): Improved detecting errors in broken pickle data.

   - bpo-25717(140): Restore the previous behaviour of tolerating most
     fstat() errors when opening files.  This was a regression in 3.5a1,
     and stopped anonymous temporary files from working in special
     cases.

   - bpo-24903(141): Fix regression in number of arguments compileall
     accepts when “-d” is specified.  The check on the number of
     arguments has been dropped completely as it never worked correctly
     anyway.

   - bpo-25764(142): In the subprocess module, preserve any exception
     caused by fork() failure when preexec_fn is used.

   - bpo-25771(143): Tweak the exception message for
     importlib.util.resolve_name() when “package” isn’t specified but
     necessary.

   - bpo-6478(144): _strptime’s regexp cache now is reset after changing
     timezone with time.tzset().

   - bpo-14285(145): When executing a package with the «python -m
     package» option, and package initialization fails, a proper
     traceback is now reported.  The «runpy» module now lets exceptions
     from package initialization pass back to the caller, rather than
     raising ImportError.

   - bpo-19771(146): Also in runpy and the «-m» option, omit the
     irrelevant message «… is a package and cannot be directly executed»
     if the package could not even be initialized (e.g.  due to a bad
     ‘*.pyc’ file).

   - bpo-25177(147): Fixed problem with the mean of very small and very
     large numbers.  As a side effect, statistics.mean and
     statistics.variance should be significantly faster.

   - bpo-25718(148): Fixed copying object with state with boolean value
     is false.

   - bpo-10131(149): Fixed deep copying of minidom documents.  Based on
     patch by Marian Ganisin.

   - bpo-7990(150): dir() on ElementTree.Element now lists properties:
     «tag», «text», «tail» and «attrib».  Original patch by Santoso
     Wijaya.

   - bpo-25725(151): Fixed a reference leak in pickle.loads() when
     unpickling invalid data including tuple instructions.

   - bpo-25663(152): In the Readline completer, avoid listing duplicate
     global names, and search the global namespace before searching
     builtins.

   - bpo-25688(153): Fixed file leak in ElementTree.iterparse() raising
     an error.

   - bpo-23914(154): Fixed SystemError raised by unpickler on broken
     pickle data.

   - bpo-25691(155): Fixed crash on deleting ElementTree.Element
     attributes.

   - bpo-25624(156): ZipFile now always writes a ZIP_STORED header for
     directory entries.  Patch by Dingyuan Wang.

   - bpo-25626(157): Change three zlib functions to accept sizes that
     fit in Py_ssize_t, but internally cap those sizes to UINT_MAX. This
     resolves a regression in 3.5 where GzipFile.read() failed to read
     chunks larger than 2 or 4 GiB. The change affects the
     zlib.Decompress.decompress() max_length parameter, the
     zlib.decompress() bufsize parameter, and the
     zlib.Decompress.flush() length parameter.

   - bpo-25583(158): Avoid incorrect errors raised by
     os.makedirs(exist_ok=True) when the OS gives priority to errors
     such as EACCES over EEXIST.

   - bpo-25593(159): Change semantics of EventLoop.stop() in asyncio.

   - bpo-6973(160): When we know a subprocess.Popen process has died, do
     not allow the send_signal(), terminate(), or kill() methods to do
     anything as they could potentially signal a different process.

   - bpo-23883(161): Added missing APIs to __all__ to match the
     documented APIs for the following modules: calendar, csv, enum,
     fileinput, ftplib, logging, optparse, tarfile, threading and wave.
     Also added a test.support.check__all__() helper.  Patches by Jacek
     Kołodziej, Mauro S. M. Rodrigues and Joel Taddei.

   - bpo-25590(162): In the Readline completer, only call getattr() once
     per attribute.  Also complete names of attributes such as
     properties and slots which are listed by dir() but not yet created
     on an instance.

   - bpo-25498(163): Fix a crash when garbage-collecting ctypes objects
     created by wrapping a memoryview.  This was a regression made in
     3.5a1.  Based on patch by Eryksun.

   - bpo-25584(164): Added «escape» to the __all__ list in the glob
     module.

   - bpo-25584(165): Fixed recursive glob() with patterns starting with
     ‘**’.

   - bpo-25446(166): Fix regression in smtplib’s AUTH LOGIN support.

   - bpo-18010(167): Fix the pydoc web server’s module search function
     to handle exceptions from importing packages.

   - bpo-25554(168): Got rid of circular references in regular
     expression parsing.

   - bpo-18973(169): Command-line interface of the calendar module now
     uses argparse instead of optparse.

   - bpo-25510(170): fileinput.FileInput.readline() now returns b””
     instead of “” at the end if the FileInput was opened with binary
     mode.  Patch by Ryosuke Ito.

   - bpo-25503(171): Fixed inspect.getdoc() for inherited docstrings of
     properties.  Original patch by John Mark Vandenberg.

   - bpo-25515(172): Always use os.urandom as a source of randomness in
     uuid.uuid4.

   - bpo-21827(173): Fixed textwrap.dedent() for the case when largest
     common whitespace is a substring of smallest leading whitespace.
     Based on patch by Robert Li.

   - bpo-25447(174): The lru_cache() wrapper objects now can be copied
     and pickled (by returning the original object unchanged).

   - bpo-25390(175): typing: Don’t crash on Union[str, Pattern].

   - bpo-25441(176): asyncio: Raise error from drain() when socket is
     closed.

   - bpo-25410(177): Cleaned up and fixed minor bugs in C implementation
     of OrderedDict.

   - bpo-25411(178): Improved Unicode support in SMTPHandler through
     better use of the email package.  Thanks to user simon04 for the
     patch.

   - Move the imp module from a PendingDeprecationWarning to
     DeprecationWarning.

   - bpo-25407(179): Remove mentions of the formatter module being
     removed in Python 3.6.

   - bpo-25406(180): Fixed a bug in C implementation of
     OrderedDict.move_to_end() that caused segmentation fault or hang in
     iterating after moving several items to the start of ordered dict.

   - bpo-25382(181): pickletools.dis() now outputs implicit memo index
     for the MEMOIZE opcode.

   - bpo-25357(182): Add an optional newline parameter to
     binascii.b2a_base64().  base64.b64encode() uses it to avoid a
     memory copy.

   - bpo-24164(183): Objects that need calling ‘__new__’ with keyword
     arguments, can now be pickled using pickle protocols older than
     protocol version 4.

   - bpo-25364(184): zipfile now works in threads disabled builds.

   - bpo-25328(185): smtpd’s SMTPChannel now correctly raises a
     ValueError if both decode_data and enable_SMTPUTF8 are set to true.

   - bpo-16099(186): RobotFileParser now supports Crawl-delay and
     Request-rate extensions.  Patch by Nikolay Bogoychev.

   - bpo-25316(187): distutils raises OSError instead of
     DistutilsPlatformError when MSVC is not installed.

   - bpo-25380(188): Fixed protocol for the STACK_GLOBAL opcode in
     pickletools.opcodes.

   - bpo-23972(189): Updates asyncio datagram create method allowing
     reuseport and reuseaddr socket options to be set prior to binding
     the socket.  Mirroring the existing asyncio create_server method
     the reuseaddr option for datagram sockets defaults to True if the
     O/S is “posix” (except if the platform is Cygwin).  Patch by Chris
     Laws.

   - bpo-25304(190): Add asyncio.run_coroutine_threadsafe().  This lets
     you submit a coroutine to a loop from another thread, returning a
     concurrent.futures.Future.  By Vincent Michel.

   - bpo-25232(191): Fix CGIRequestHandler to split the query from the
     URL at the first question mark (?)  rather than the last.  Patch
     from Xiang Zhang.

   - bpo-24657(192): Prevent CGIRequestHandler from collapsing slashes
     in the query part of the URL as if it were a path.  Patch from
     Xiang Zhang.

   - bpo-25287(193): Don’t add crypt.METHOD_CRYPT to crypt.methods if
     it’s not supported.  Check if it is supported, it may not be
     supported on OpenBSD for example.

   - bpo-23600(194): Default implementation of tzinfo.fromutc() was
     returning wrong results in some cases.

   - bpo-25203(195): Failed readline.set_completer_delims() no longer
     left the module in inconsistent state.

   - bpo-25011(196): rlcompleter now omits private and special attribute
     names unless the prefix starts with underscores.

   - bpo-25209(197): rlcompleter now can add a space or a colon after
     completed keyword.

   - bpo-22241(198): timezone.utc name is now plain “UTC”, not
     “UTC-00:00”.

   - bpo-23517(199): fromtimestamp() and utcfromtimestamp() methods of
     datetime.datetime now round microseconds to nearest with ties going
     to nearest even integer (ROUND_HALF_EVEN), as round(float), instead
     of rounding towards -Infinity (ROUND_FLOOR).

   - bpo-23552(200): Timeit now warns when there is substantial (4x)
     variance between best and worst times.  Patch from Serhiy
     Storchaka.

   - bpo-24633(201): site-packages/README -> README.txt.

   - bpo-24879(202): help() and pydoc can now list named tuple fields in
     the order they were defined rather than alphabetically.  The
     ordering is determined by the _fields attribute if present.

   - bpo-24874(203): Improve speed of itertools.cycle() and make its
     pickle more compact.

   - Fix crash in itertools.cycle.__setstate__() when the first argument
     wasn’t a list.

   - bpo-20059(204): urllib.parse raises ValueError on all invalid
     ports.  Patch by Martin Panter.

   - bpo-24360(205): Improve __repr__ of argparse.Namespace() for
     invalid identifiers.  Patch by Matthias Bussonnier.

   - bpo-23426(206): run_setup was broken in distutils.  Patch from
     Alexander Belopolsky.

   - bpo-13938(207): 2to3 converts StringTypes to a tuple.  Patch from
     Mark Hammond.

   - bpo-2091(208): open() accepted a “U” mode string containing “+”,
     but “U” can only be used with “r”.  Patch from Jeff Balogh and John
     O’Connor.

   - bpo-8585(209): improved tests for zipimporter2.  Patch from Mark
     Lawrence.

   - bpo-18622(210): unittest.mock.mock_open().reset_mock would recurse
     infinitely.  Patch from Nicola Palumbo and Laurent De Buyst.

   - bpo-24426(211): Fast searching optimization in regular expressions
     now works for patterns that starts with capturing groups.  Fast
     searching optimization now can’t be disabled at compile time.

   - bpo-23661(212): unittest.mock side_effects can now be exceptions
     again.  This was a regression vs Python 3.4.  Patch from Ignacio
     Rossi

   - bpo-13248(213): Remove deprecated inspect.getmoduleinfo function.

   - bpo-25578(214): Fix (another) memory leak in
     SSLSocket.getpeercer().

   - bpo-25530(215): Disable the vulnerable SSLv3 protocol by default
     when creating ssl.SSLContext.

   - bpo-25569(216): Fix memory leak in SSLSocket.getpeercert().

   - bpo-25471(217): Sockets returned from accept() shouldn’t appear to
     be nonblocking.

   - bpo-25319(218): When threading.Event is reinitialized, the
     underlying condition should use a regular lock rather than a
     recursive lock.

   - Skip getaddrinfo if host is already resolved.  Patch by A. Jesse
     Jiryu Davis.

   - bpo-26050(219): Add asyncio.StreamReader.readuntil() method.  Patch
     by Марк Коренберг.

   - bpo-25924(220): Avoid unnecessary serialization of getaddrinfo(3)
     calls on OS X versions 10.5 or higher.  Original patch by A. Jesse
     Jiryu Davis.

   - bpo-26406(221): Avoid unnecessary serialization of getaddrinfo(3)
     calls on current versions of OpenBSD and NetBSD. Patch by A. Jesse
     Jiryu Davis.

   - bpo-26848(222): Fix asyncio/subprocess.communicate() to handle
     empty input.  Patch by Jack O’Connor.

   - bpo-27040(223): Add loop.get_exception_handler method

   - bpo-27041(224): asyncio: Add loop.create_future method

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27057

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27014

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27031

   (4) https://bugs.python.org/issue?@action=redirect&bpo=14132

   (5) https://bugs.python.org/issue?@action=redirect&bpo=17214

   (6) https://bugs.python.org/issue?@action=redirect&bpo=27033

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27034

   (8) https://bugs.python.org/issue?@action=redirect&bpo=26870

   (9) https://bugs.python.org/issue?@action=redirect&bpo=26039

   (10) https://bugs.python.org/issue?@action=redirect&bpo=26892

   (11) https://bugs.python.org/issue?@action=redirect&bpo=22274

   (12) https://bugs.python.org/issue?@action=redirect&bpo=26807

   (13) https://bugs.python.org/issue?@action=redirect&bpo=25745

   (14) https://bugs.python.org/issue?@action=redirect&bpo=26977

   (15) https://bugs.python.org/issue?@action=redirect&bpo=26002

   (16) https://bugs.python.org/issue?@action=redirect&bpo=25974

   (17) https://bugs.python.org/issue?@action=redirect&bpo=26996

   (18) https://peps.python.org/pep-0506/

   (19) https://bugs.python.org/issue?@action=redirect&bpo=26881

   (20) https://bugs.python.org/issue?@action=redirect&bpo=23815

   (21) https://bugs.python.org/issue?@action=redirect&bpo=17765

   (22) https://bugs.python.org/issue?@action=redirect&bpo=26873

   (23) https://bugs.python.org/issue?@action=redirect&bpo=26915

   (24) https://bugs.python.org/issue?@action=redirect&bpo=26711

   (25) https://bugs.python.org/issue?@action=redirect&bpo=24114

   (26) https://bugs.python.org/issue?@action=redirect&bpo=26864

   (27) https://bugs.python.org/issue?@action=redirect&bpo=24902

   (28) https://bugs.python.org/issue?@action=redirect&bpo=25788

   (29) https://bugs.python.org/issue?@action=redirect&bpo=26634

   (30) https://bugs.python.org/issue?@action=redirect&bpo=26804

   (31) https://bugs.python.org/issue?@action=redirect&bpo=26837

   (32) https://bugs.python.org/issue?@action=redirect&bpo=26041

   (33) https://bugs.python.org/issue?@action=redirect&bpo=26822

   (34) https://bugs.python.org/issue?@action=redirect&bpo=26733

   (35) https://bugs.python.org/issue?@action=redirect&bpo=26801

   (36) https://bugs.python.org/issue?@action=redirect&bpo=24838

   (37) https://bugs.python.org/issue?@action=redirect&bpo=26717

   (38) https://bugs.python.org/issue?@action=redirect&bpo=26782

   (39) https://bugs.python.org/issue?@action=redirect&bpo=26404

   (40) https://bugs.python.org/issue?@action=redirect&bpo=26735

   (41) https://bugs.python.org/issue?@action=redirect&bpo=26585

   (42) https://bugs.python.org/issue?@action=redirect&bpo=26685

   (43) https://bugs.python.org/issue?@action=redirect&bpo=16329

   (44) https://bugs.python.org/issue?@action=redirect&bpo=13952

   (45) https://bugs.python.org/issue?@action=redirect&bpo=26587

   (46) https://bugs.python.org/issue?@action=redirect&bpo=25609

   (47) https://bugs.python.org/issue?@action=redirect&bpo=26709

   (48) https://bugs.python.org/issue?@action=redirect&bpo=23735

   (49) https://bugs.python.org/issue?@action=redirect&bpo=25951

   (50) https://bugs.python.org/issue?@action=redirect&bpo=26586

   (51) https://bugs.python.org/issue?@action=redirect&bpo=26676

   (52) https://bugs.python.org/issue?@action=redirect&bpo=22854

   (53) https://bugs.python.org/issue?@action=redirect&bpo=26492

   (54) https://bugs.python.org/issue?@action=redirect&bpo=26641

   (55) https://bugs.python.org/issue?@action=redirect&bpo=25195

   (56) https://bugs.python.org/issue?@action=redirect&bpo=26644

   (57) https://bugs.python.org/issue?@action=redirect&bpo=23804

   (58) https://bugs.python.org/issue?@action=redirect&bpo=26616

   (59) https://bugs.python.org/issue?@action=redirect&bpo=26637

   (60) https://bugs.python.org/issue?@action=redirect&bpo=21925

   (61) https://bugs.python.org/issue?@action=redirect&bpo=23848

   (62) https://bugs.python.org/issue?@action=redirect&bpo=26530

   (63) https://bugs.python.org/issue?@action=redirect&bpo=26588

   (64) https://bugs.python.org/issue?@action=redirect&bpo=24266

   (65) https://bugs.python.org/issue?@action=redirect&bpo=26590

   (66) https://bugs.python.org/issue?@action=redirect&bpo=18787

   (67) https://bugs.python.org/issue?@action=redirect&bpo=26560

   (68) https://bugs.python.org/issue?@action=redirect&bpo=26567

   (69) https://bugs.python.org/issue?@action=redirect&bpo=26569

   (70) https://bugs.python.org/issue?@action=redirect&bpo=26499

   (71) https://bugs.python.org/issue?@action=redirect&bpo=25320

   (72) https://bugs.python.org/issue?@action=redirect&bpo=16181

   (73) https://bugs.python.org/issue?@action=redirect&bpo=26513

   (74) https://bugs.python.org/issue?@action=redirect&bpo=23718

   (75) https://bugs.python.org/issue?@action=redirect&bpo=26323

   (76) https://bugs.python.org/issue?@action=redirect&bpo=20589

   (77) https://bugs.python.org/issue?@action=redirect&bpo=26177

   (78) https://bugs.python.org/issue?@action=redirect&bpo=15068

   (79) https://bugs.python.org/issue?@action=redirect&bpo=19475

   (80) https://bugs.python.org/issue?@action=redirect&bpo=2202

   (81) https://bugs.python.org/issue?@action=redirect&bpo=26167

   (82) https://bugs.python.org/issue?@action=redirect&bpo=25718

   (83) https://bugs.python.org/issue?@action=redirect&bpo=26475

   (84) https://bugs.python.org/issue?@action=redirect&bpo=26482

   (85) https://bugs.python.org/issue?@action=redirect&bpo=26335

   (86) https://bugs.python.org/issue?@action=redirect&bpo=26457

   (87) https://bugs.python.org/issue?@action=redirect&bpo=26385

   (88) https://bugs.python.org/issue?@action=redirect&bpo=26402

   (89) https://bugs.python.org/issue?@action=redirect&bpo=25913

   (90) https://bugs.python.org/issue?@action=redirect&bpo=26186

   (91) https://bugs.python.org/issue?@action=redirect&bpo=26367

   (92) https://bugs.python.org/issue?@action=redirect&bpo=26309

   (93) https://bugs.python.org/issue?@action=redirect&bpo=23430

   (94) https://bugs.python.org/issue?@action=redirect&bpo=25995

   (95) https://bugs.python.org/issue?@action=redirect&bpo=25994

   (96) https://bugs.python.org/issue?@action=redirect&bpo=23992

   (97) https://bugs.python.org/issue?@action=redirect&bpo=26243

   (98) https://bugs.python.org/issue?@action=redirect&bpo=26117

   (99) https://bugs.python.org/issue?@action=redirect&bpo=25949

   (100) https://bugs.python.org/issue?@action=redirect&bpo=25911

   (101) https://bugs.python.org/issue?@action=redirect&bpo=26045

   (102) https://bugs.python.org/issue?@action=redirect&bpo=26039

   (103) https://bugs.python.org/issue?@action=redirect&bpo=12923

   (104) https://bugs.python.org/issue?@action=redirect&bpo=25945

   (105) https://bugs.python.org/issue?@action=redirect&bpo=26202

   (106) https://bugs.python.org/issue?@action=redirect&bpo=23076

   (107) https://bugs.python.org/issue?@action=redirect&bpo=19883

   (108) https://bugs.python.org/issue?@action=redirect&bpo=26227

   (109) https://bugs.python.org/issue?@action=redirect&bpo=26099

   (110) https://bugs.python.org/issue?@action=redirect&bpo=26147

   (111) https://bugs.python.org/issue?@action=redirect&bpo=25935

   (112) https://bugs.python.org/issue?@action=redirect&bpo=16620

   (113) https://bugs.python.org/issue?@action=redirect&bpo=26013

   (114) https://bugs.python.org/issue?@action=redirect&bpo=26129

   (115) https://bugs.python.org/issue?@action=redirect&bpo=25850

   (116) https://bugs.python.org/issue?@action=redirect&bpo=25822

   (117) https://bugs.python.org/issue?@action=redirect&bpo=22642

   (118) https://bugs.python.org/issue?@action=redirect&bpo=24705

   (119) https://bugs.python.org/issue?@action=redirect&bpo=26069

   (120) https://bugs.python.org/issue?@action=redirect&bpo=22138

   (121) https://bugs.python.org/issue?@action=redirect&bpo=25672

   (122) https://bugs.python.org/issue?@action=redirect&bpo=26012

   (123) https://bugs.python.org/issue?@action=redirect&bpo=24120

   (124) https://bugs.python.org/issue?@action=redirect&bpo=21815

   (125) https://bugs.python.org/issue?@action=redirect&bpo=25447

   (126) https://bugs.python.org/issue?@action=redirect&bpo=25971

   (127) https://bugs.python.org/issue?@action=redirect&bpo=25802

   (128) https://bugs.python.org/issue?@action=redirect&bpo=25928

   (129) https://bugs.python.org/issue?@action=redirect&bpo=25447

   (130) https://bugs.python.org/issue?@action=redirect&bpo=25768

   (131) https://bugs.python.org/issue?@action=redirect&bpo=24103

   (132) https://bugs.python.org/issue?@action=redirect&bpo=25860

   (133) https://bugs.python.org/issue?@action=redirect&bpo=25914

   (134) https://bugs.python.org/issue?@action=redirect&bpo=25869

   (135) https://bugs.python.org/issue?@action=redirect&bpo=25873

   (136) https://bugs.python.org/issue?@action=redirect&bpo=25902

   (137) https://bugs.python.org/issue?@action=redirect&bpo=22227

   (138) https://bugs.python.org/issue?@action=redirect&bpo=25638

   (139) https://bugs.python.org/issue?@action=redirect&bpo=25761

   (140) https://bugs.python.org/issue?@action=redirect&bpo=25717

   (141) https://bugs.python.org/issue?@action=redirect&bpo=24903

   (142) https://bugs.python.org/issue?@action=redirect&bpo=25764

   (143) https://bugs.python.org/issue?@action=redirect&bpo=25771

   (144) https://bugs.python.org/issue?@action=redirect&bpo=6478

   (145) https://bugs.python.org/issue?@action=redirect&bpo=14285

   (146) https://bugs.python.org/issue?@action=redirect&bpo=19771

   (147) https://bugs.python.org/issue?@action=redirect&bpo=25177

   (148) https://bugs.python.org/issue?@action=redirect&bpo=25718

   (149) https://bugs.python.org/issue?@action=redirect&bpo=10131

   (150) https://bugs.python.org/issue?@action=redirect&bpo=7990

   (151) https://bugs.python.org/issue?@action=redirect&bpo=25725

   (152) https://bugs.python.org/issue?@action=redirect&bpo=25663

   (153) https://bugs.python.org/issue?@action=redirect&bpo=25688

   (154) https://bugs.python.org/issue?@action=redirect&bpo=23914

   (155) https://bugs.python.org/issue?@action=redirect&bpo=25691

   (156) https://bugs.python.org/issue?@action=redirect&bpo=25624

   (157) https://bugs.python.org/issue?@action=redirect&bpo=25626

   (158) https://bugs.python.org/issue?@action=redirect&bpo=25583

   (159) https://bugs.python.org/issue?@action=redirect&bpo=25593

   (160) https://bugs.python.org/issue?@action=redirect&bpo=6973

   (161) https://bugs.python.org/issue?@action=redirect&bpo=23883

   (162) https://bugs.python.org/issue?@action=redirect&bpo=25590

   (163) https://bugs.python.org/issue?@action=redirect&bpo=25498

   (164) https://bugs.python.org/issue?@action=redirect&bpo=25584

   (165) https://bugs.python.org/issue?@action=redirect&bpo=25584

   (166) https://bugs.python.org/issue?@action=redirect&bpo=25446

   (167) https://bugs.python.org/issue?@action=redirect&bpo=18010

   (168) https://bugs.python.org/issue?@action=redirect&bpo=25554

   (169) https://bugs.python.org/issue?@action=redirect&bpo=18973

   (170) https://bugs.python.org/issue?@action=redirect&bpo=25510

   (171) https://bugs.python.org/issue?@action=redirect&bpo=25503

   (172) https://bugs.python.org/issue?@action=redirect&bpo=25515

   (173) https://bugs.python.org/issue?@action=redirect&bpo=21827

   (174) https://bugs.python.org/issue?@action=redirect&bpo=25447

   (175) https://bugs.python.org/issue?@action=redirect&bpo=25390

   (176) https://bugs.python.org/issue?@action=redirect&bpo=25441

   (177) https://bugs.python.org/issue?@action=redirect&bpo=25410

   (178) https://bugs.python.org/issue?@action=redirect&bpo=25411

   (179) https://bugs.python.org/issue?@action=redirect&bpo=25407

   (180) https://bugs.python.org/issue?@action=redirect&bpo=25406

   (181) https://bugs.python.org/issue?@action=redirect&bpo=25382

   (182) https://bugs.python.org/issue?@action=redirect&bpo=25357

   (183) https://bugs.python.org/issue?@action=redirect&bpo=24164

   (184) https://bugs.python.org/issue?@action=redirect&bpo=25364

   (185) https://bugs.python.org/issue?@action=redirect&bpo=25328

   (186) https://bugs.python.org/issue?@action=redirect&bpo=16099

   (187) https://bugs.python.org/issue?@action=redirect&bpo=25316

   (188) https://bugs.python.org/issue?@action=redirect&bpo=25380

   (189) https://bugs.python.org/issue?@action=redirect&bpo=23972

   (190) https://bugs.python.org/issue?@action=redirect&bpo=25304

   (191) https://bugs.python.org/issue?@action=redirect&bpo=25232

   (192) https://bugs.python.org/issue?@action=redirect&bpo=24657

   (193) https://bugs.python.org/issue?@action=redirect&bpo=25287

   (194) https://bugs.python.org/issue?@action=redirect&bpo=23600

   (195) https://bugs.python.org/issue?@action=redirect&bpo=25203

   (196) https://bugs.python.org/issue?@action=redirect&bpo=25011

   (197) https://bugs.python.org/issue?@action=redirect&bpo=25209

   (198) https://bugs.python.org/issue?@action=redirect&bpo=22241

   (199) https://bugs.python.org/issue?@action=redirect&bpo=23517

   (200) https://bugs.python.org/issue?@action=redirect&bpo=23552

   (201) https://bugs.python.org/issue?@action=redirect&bpo=24633

   (202) https://bugs.python.org/issue?@action=redirect&bpo=24879

   (203) https://bugs.python.org/issue?@action=redirect&bpo=24874

   (204) https://bugs.python.org/issue?@action=redirect&bpo=20059

   (205) https://bugs.python.org/issue?@action=redirect&bpo=24360

   (206) https://bugs.python.org/issue?@action=redirect&bpo=23426

   (207) https://bugs.python.org/issue?@action=redirect&bpo=13938

   (208) https://bugs.python.org/issue?@action=redirect&bpo=2091

   (209) https://bugs.python.org/issue?@action=redirect&bpo=8585

   (210) https://bugs.python.org/issue?@action=redirect&bpo=18622

   (211) https://bugs.python.org/issue?@action=redirect&bpo=24426

   (212) https://bugs.python.org/issue?@action=redirect&bpo=23661

   (213) https://bugs.python.org/issue?@action=redirect&bpo=13248

   (214) https://bugs.python.org/issue?@action=redirect&bpo=25578

   (215) https://bugs.python.org/issue?@action=redirect&bpo=25530

   (216) https://bugs.python.org/issue?@action=redirect&bpo=25569

   (217) https://bugs.python.org/issue?@action=redirect&bpo=25471

   (218) https://bugs.python.org/issue?@action=redirect&bpo=25319

   (219) https://bugs.python.org/issue?@action=redirect&bpo=26050

   (220) https://bugs.python.org/issue?@action=redirect&bpo=25924

   (221) https://bugs.python.org/issue?@action=redirect&bpo=26406

   (222) https://bugs.python.org/issue?@action=redirect&bpo=26848

   (223) https://bugs.python.org/issue?@action=redirect&bpo=27040

   (224) https://bugs.python.org/issue?@action=redirect&bpo=27041


File: python.info,  Node: IDLE<56>,  Next: Documentation<76>,  Prev: Library<188>,  Up: Python 3 6 0 alpha 1

1.24.96.4 IDLE
..............

   - bpo-20640(1): Add tests for idlelib.configHelpSourceEdit.  Patch by
     Saimadhav Heblikar.

   - In the “IDLE-console differences” section of the IDLE doc, clarify
     how running with IDLE affects sys.modules and the standard streams.

   - bpo-25507(2): fix incorrect change in IOBinding that prevented
     printing.  Augment IOBinding htest to include all major IOBinding
     functions.

   - bpo-25905(3): Revert unwanted conversion of “ to ’ RIGHT SINGLE
     QUOTATION MARK in README.txt and open this and NEWS.txt with
     “ascii”.  Re-encode CREDITS.txt to utf-8 and open it with “utf-8”.

   - bpo-15348(4): Stop the debugger engine (normally in a user process)
     before closing the debugger window (running in the IDLE process).
     This prevents the RuntimeErrors that were being caught and ignored.

   - bpo-24455(5): Prevent IDLE from hanging when a) closing the shell
     while the debugger is active (15347); b) closing the debugger with
     the [X] button (15348); and c) activating the debugger when already
     active (24455).  The patch by Mark Roseman does this by making two
     changes.  1.  Suspend and resume the gui.interaction method with
     the tcl vwait mechanism intended for this purpose (instead of
     root.mainloop & .quit).  2.  In gui.run, allow any existing
     interaction to terminate first.

   - Change “The program” to “Your program” in an IDLE “kill program?”
     message to make it clearer that the program referred to is the
     currently running user program, not IDLE itself.

   - bpo-24750(6): Improve the appearance of the IDLE editor window
     status bar.  Patch by Mark Roseman.

   - bpo-25313(7): Change the handling of new built-in text color themes
     to better address the compatibility problem introduced by the
     addition of IDLE Dark.  Consistently use the revised
     idleConf.CurrentTheme everywhere in idlelib.

   - bpo-24782(8): Extension configuration is now a tab in the IDLE
     Preferences dialog rather than a separate dialog.  The former tabs
     are now a sorted list.  Patch by Mark Roseman.

   - bpo-22726(9): Re-activate the config dialog help button with some
     content about the other buttons and the new IDLE Dark theme.

   - bpo-24820(10): IDLE now has an “IDLE Dark” built-in text color
     theme.  It is more or less IDLE Classic inverted, with a cobalt
     blue background.  Strings, comments, keywords, … are still green,
     red, orange, … .  To use it with IDLEs released before November
     2015, hit the “Save as New Custom Theme” button and enter a new
     name, such as “Custom Dark”.  The custom theme will work with any
     IDLE release, and can be modified.

   - bpo-25224(11): README.txt is now an idlelib index for IDLE
     developers and curious users.  The previous user content is now in
     the IDLE doc chapter.  “IDLE” now means “Integrated Development and
     Learning Environment”.

   - bpo-24820(12): Users can now set breakpoint colors in Settings ->
     Custom Highlighting.  Original patch by Mark Roseman.

   - bpo-24972(13): Inactive selection background now matches active
     selection background, as configured by users, on all systems.
     Found items are now always highlighted on Windows.  Initial patch
     by Mark Roseman.

   - bpo-24570(14): Idle: make calltip and completion boxes appear on
     Macs affected by a tk regression.  Initial patch by Mark Roseman.

   - bpo-24988(15): Idle ScrolledList context menus (used in debugger)
     now work on Mac Aqua.  Patch by Mark Roseman.

   - bpo-24801(16): Make right-click for context menu work on Mac Aqua.
     Patch by Mark Roseman.

   - bpo-25173(17): Associate tkinter messageboxes with a specific
     widget.  For Mac OSX, make them a “sheet”.  Patch by Mark Roseman.

   - bpo-25198(18): Enhance the initial html viewer now used for Idle
     Help.  Properly indent fixed-pitch text (patch by Mark Roseman).
     Give code snippet a very Sphinx-like light blueish-gray background.
     Re-use initial width and height set by users for shell and editor.
     When the Table of Contents (TOC) menu is used, put the section
     header at the top of the screen.

   - bpo-25225(19): Condense and rewrite Idle doc section on text
     colors.

   - bpo-21995(20): Explain some differences between IDLE and console
     Python.

   - bpo-22820(21): Explain need for 'print' when running file from Idle
     editor.

   - bpo-25224(22): Doc: augment Idle feature list and no-subprocess
     section.

   - bpo-25219(23): Update doc for Idle command line options.  Some were
     missing and notes were not correct.

   - bpo-24861(24): Most of idlelib is private and subject to change.
     Use idleib.idle.* to start Idle.  See idlelib.__init__.__doc__.

   - bpo-25199(25): Idle: add synchronization comments for future
     maintainers.

   - bpo-16893(26): Replace help.txt with help.html for Idle doc
     display.  The new idlelib/help.html is rstripped
     Doc/build/html/library/idle.html.  It looks better than help.txt
     and will better document Idle as released.  The tkinter html viewer
     that works for this file was written by Rose Roseman.  The now
     unused EditorWindow.HelpDialog class and helt.txt file are
     deprecated.

   - bpo-24199(27): Deprecate unused idlelib.idlever with possible
     removal in 3.6.

   - bpo-24790(28): Remove extraneous code (which also create 2 & 3
     conflicts).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20640

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25507

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25905

   (4) https://bugs.python.org/issue?@action=redirect&bpo=15348

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24455

   (6) https://bugs.python.org/issue?@action=redirect&bpo=24750

   (7) https://bugs.python.org/issue?@action=redirect&bpo=25313

   (8) https://bugs.python.org/issue?@action=redirect&bpo=24782

   (9) https://bugs.python.org/issue?@action=redirect&bpo=22726

   (10) https://bugs.python.org/issue?@action=redirect&bpo=24820

   (11) https://bugs.python.org/issue?@action=redirect&bpo=25224

   (12) https://bugs.python.org/issue?@action=redirect&bpo=24820

   (13) https://bugs.python.org/issue?@action=redirect&bpo=24972

   (14) https://bugs.python.org/issue?@action=redirect&bpo=24570

   (15) https://bugs.python.org/issue?@action=redirect&bpo=24988

   (16) https://bugs.python.org/issue?@action=redirect&bpo=24801

   (17) https://bugs.python.org/issue?@action=redirect&bpo=25173

   (18) https://bugs.python.org/issue?@action=redirect&bpo=25198

   (19) https://bugs.python.org/issue?@action=redirect&bpo=25225

   (20) https://bugs.python.org/issue?@action=redirect&bpo=21995

   (21) https://bugs.python.org/issue?@action=redirect&bpo=22820

   (22) https://bugs.python.org/issue?@action=redirect&bpo=25224

   (23) https://bugs.python.org/issue?@action=redirect&bpo=25219

   (24) https://bugs.python.org/issue?@action=redirect&bpo=24861

   (25) https://bugs.python.org/issue?@action=redirect&bpo=25199

   (26) https://bugs.python.org/issue?@action=redirect&bpo=16893

   (27) https://bugs.python.org/issue?@action=redirect&bpo=24199

   (28) https://bugs.python.org/issue?@action=redirect&bpo=24790


File: python.info,  Node: Documentation<76>,  Next: Tests<77>,  Prev: IDLE<56>,  Up: Python 3 6 0 alpha 1

1.24.96.5 Documentation
.......................

   - bpo-26736(1): Used HTTPS for external links in the documentation if
     possible.

   - bpo-6953(2): Rework the Readline module documentation to group
     related functions together, and add more details such as what
     underlying Readline functions and variables are accessed.

   - bpo-23606(3): Adds note to ctypes documentation regarding
     cdll.msvcrt.

   - bpo-24952(4): Clarify the default size argument of stack_size() in
     the «threading» and «_thread» modules.  Patch from Mattip.

   - bpo-26014(5): Update 3.x packaging documentation: * «See also»
     links to the new docs are now provided in the legacy pages * links
     to setuptools documentation have been updated

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26736

   (2) https://bugs.python.org/issue?@action=redirect&bpo=6953

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23606

   (4) https://bugs.python.org/issue?@action=redirect&bpo=24952

   (5) https://bugs.python.org/issue?@action=redirect&bpo=26014


File: python.info,  Node: Tests<77>,  Next: Build<88>,  Prev: Documentation<76>,  Up: Python 3 6 0 alpha 1

1.24.96.6 Tests
...............

   - bpo-21916(1): Added tests for the turtle module.  Patch by ingrid,
     Gregory Loyse and Jelle Zijlstra.

   - bpo-26295(2): When using «python3 -m test –testdir=TESTDIR»,
     regrtest doesn’t add «test.» prefix to test module names.

   - bpo-26523(3): The multiprocessing thread pool
     (multiprocessing.dummy.Pool) was untested.

   - bpo-26015(4): Added new tests for pickling iterators of mutable
     sequences.

   - bpo-26325(5): Added test.support.check_no_resource_warning() to
     check that no ResourceWarning is emitted.

   - bpo-25940(6): Changed test_ssl to use its internal local server
     more.  This avoids relying on svn.python.org, which recently
     changed root certificate.

   - bpo-25616(7): Tests for OrderedDict are extracted from
     test_collections into separate file test_ordered_dict.

   - bpo-25449(8): Added tests for OrderedDict subclasses.

   - bpo-25188(9): Add -P/–pgo to test.regrtest to suppress error output
     when running the test suite for the purposes of a PGO build.
     Initial patch by Alecsandru Patrascu.

   - bpo-22806(10): Add ‘python -m test --list-tests’ command to list
     tests.

   - bpo-18174(11): ‘python -m test --huntrleaks ...’ now also checks
     for leak of file descriptors.  Patch written by Richard Oudkerk.

   - bpo-25260(12): Fix ‘python -m test --coverage’ on Windows.  Remove
     the list of ignored directories.

   - ‘PCbuild\rt.bat’ now accepts an unlimited number of arguments to
     pass along to regrtest.py.  Previously there was a limit of 9.

   - bpo-26583(13): Skip test_timestamp_overflow in test_import if
     bytecode files cannot be written.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21916

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26295

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26523

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26015

   (5) https://bugs.python.org/issue?@action=redirect&bpo=26325

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25940

   (7) https://bugs.python.org/issue?@action=redirect&bpo=25616

   (8) https://bugs.python.org/issue?@action=redirect&bpo=25449

   (9) https://bugs.python.org/issue?@action=redirect&bpo=25188

   (10) https://bugs.python.org/issue?@action=redirect&bpo=22806

   (11) https://bugs.python.org/issue?@action=redirect&bpo=18174

   (12) https://bugs.python.org/issue?@action=redirect&bpo=25260

   (13) https://bugs.python.org/issue?@action=redirect&bpo=26583


File: python.info,  Node: Build<88>,  Next: Windows<75>,  Prev: Tests<77>,  Up: Python 3 6 0 alpha 1

1.24.96.7 Build
...............

   - bpo-21277(1): Don’t try to link _ctypes with a ffi_convenience
     library.

   - bpo-26884(2): Fix linking extension modules for cross builds.
     Patch by Xavier de Gaye.

   - bpo-26932(3): Fixed support of RTLD_* constants defined as enum
     values, not via macros (in particular on Android).  Patch by Chi
     Hsuan Yen.

   - bpo-22359(4): Disable the rules for running _freeze_importlib and
     pgen when cross-compiling.  The output of these programs is
     normally saved with the source code anyway, and is still
     regenerated when doing a native build.  Patch by Xavier de Gaye.

   - bpo-21668(5): Link audioop, _datetime, _ctypes_test modules to
     libm, except on Mac OS X. Patch written by Chi Hsuan Yen.

   - bpo-25702(6): A –with-lto configure option has been added that will
     enable link time optimizations at build time during a make
     profile-opt.  Some compilers and toolchains are known to not
     produce stable code when using LTO, be sure to test things
     thoroughly before relying on it.  It can provide a few % speed up
     over profile-opt alone.

   - bpo-26624(7): Adds validation of ucrtbase[d].dll version with
     warning for old versions.

   - bpo-17603(8): Avoid error about nonexistent fileblocks.o file by
     using a lower-level check for st_blocks in struct stat.

   - bpo-26079(9): Fixing the build output folder for tix-8.4.3.6.
     Patch by Bjoern Thiel.

   - bpo-26465(10): Update Windows builds to use OpenSSL 1.0.2g.

   - bpo-25348(11): Added ‘--pgo’ and ‘--pgo-job’ arguments to
     ‘PCbuild\build.bat’ for building with Profile-Guided Optimization.
     The old ‘PCbuild\build_pgo.bat’ script is removed.

   - bpo-25827(12): Add support for building with ICC to ‘configure’,
     including a new ‘--with-icc’ flag.

   - bpo-25696(13): Fix installation of Python on UNIX with make -j9.

   - bpo-24986(14): It is now possible to build Python on Windows
     without errors when external libraries are not available.

   - bpo-24421(15): Compile Modules/_math.c once, before building
     extensions.  Previously it could fail to compile properly if the
     math and cmath builds were concurrent.

   - bpo-26465(16): Update OS X 10.5+ 32-bit-only installer to build and
     link with OpenSSL 1.0.2g.

   - bpo-26268(17): Update Windows builds to use OpenSSL 1.0.2f.

   - bpo-25136(18): Support Apple Xcode 7’s new textual SDK stub
     libraries.

   - bpo-24324(19): Do not enable unreachable code warnings when using
     gcc as the option does not work correctly in older versions of gcc
     and has been silently removed as of gcc-4.5.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21277

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26884

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26932

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22359

   (5) https://bugs.python.org/issue?@action=redirect&bpo=21668

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25702

   (7) https://bugs.python.org/issue?@action=redirect&bpo=26624

   (8) https://bugs.python.org/issue?@action=redirect&bpo=17603

   (9) https://bugs.python.org/issue?@action=redirect&bpo=26079

   (10) https://bugs.python.org/issue?@action=redirect&bpo=26465

   (11) https://bugs.python.org/issue?@action=redirect&bpo=25348

   (12) https://bugs.python.org/issue?@action=redirect&bpo=25827

   (13) https://bugs.python.org/issue?@action=redirect&bpo=25696

   (14) https://bugs.python.org/issue?@action=redirect&bpo=24986

   (15) https://bugs.python.org/issue?@action=redirect&bpo=24421

   (16) https://bugs.python.org/issue?@action=redirect&bpo=26465

   (17) https://bugs.python.org/issue?@action=redirect&bpo=26268

   (18) https://bugs.python.org/issue?@action=redirect&bpo=25136

   (19) https://bugs.python.org/issue?@action=redirect&bpo=24324


File: python.info,  Node: Windows<75>,  Next: Tools/Demos<54>,  Prev: Build<88>,  Up: Python 3 6 0 alpha 1

1.24.96.8 Windows
.................

   - bpo-27053(1): Updates make_zip.py to correctly generate library ZIP
     file.

   - bpo-26268(2): Update the prepare_ssl.py script to handle OpenSSL
     releases that don’t include the contents of the include directory
     (that is, 1.0.2e and later).

   - bpo-26071(3): bdist_wininst created binaries fail to start and find
     32bit Python

   - bpo-26073(4): Update the list of magic numbers in launcher

   - bpo-26065(5): Excludes venv from library when generating embeddable
     distro.

   - bpo-25022(6): Removed very outdated PC/example_nt/ directory.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27053

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26268

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26071

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26073

   (5) https://bugs.python.org/issue?@action=redirect&bpo=26065

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25022


File: python.info,  Node: Tools/Demos<54>,  Next: C API<74>,  Prev: Windows<75>,  Up: Python 3 6 0 alpha 1

1.24.96.9 Tools/Demos
.....................

   - bpo-26799(1): Fix python-gdb.py: don’t get C types once when the
     Python code is loaded, but get C types on demand.  The C types can
     change if python-gdb.py is loaded before the Python executable.
     Patch written by Thomas Ilsche.

   - bpo-26271(2): Fix the Freeze tool to properly use flags passed
     through configure.  Patch by Daniel Shaulov.

   - bpo-26489(3): Add dictionary unpacking support to
     Tools/parser/unparse.py.  Patch by Guo Ci Teo.

   - bpo-26316(4): Fix variable name typo in Argument Clinic.

   - bpo-25440(5): Fix output of python-config –extension-suffix.

   - bpo-25154(6): The pyvenv script has been deprecated in favour of
     ‘python3 -m venv’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26799

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26271

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26489

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26316

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25440

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25154


File: python.info,  Node: C API<74>,  Prev: Tools/Demos<54>,  Up: Python 3 6 0 alpha 1

1.24.96.10 C API
................

   - bpo-26312(1): SystemError is now raised in all programming bugs
     with using PyArg_ParseTupleAndKeywords().  RuntimeError did raised
     before in some programming bugs.

   - bpo-26198(2): ValueError is now raised instead of TypeError on
     buffer overflow in parsing «es#» and «et#» format units.
     SystemError is now raised instead of TypeError on programmatical
     error in parsing format string.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26312

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26198


File: python.info,  Node: Python 3 5 5 final,  Next: Python 3 5 5 release candidate 1,  Prev: Python 3 6 0 alpha 1,  Up: Changelog

1.24.97 Python 3.5.5 final
--------------------------

'Release date: 2018-02-04'

There were no new changes in version 3.5.5.


File: python.info,  Node: Python 3 5 5 release candidate 1,  Next: Python 3 5 4 final,  Prev: Python 3 5 5 final,  Up: Changelog

1.24.98 Python 3.5.5 release candidate 1
----------------------------------------

'Release date: 2018-01-23'

* Menu:

* Security: Security<57>.
* Core and Builtins: Core and Builtins<186>.
* Library: Library<189>.


File: python.info,  Node: Security<57>,  Next: Core and Builtins<186>,  Up: Python 3 5 5 release candidate 1

1.24.98.1 Security
..................

   - bpo-32551(1): The ‘sys.path[0]’ initialization change for
     bpo-29139(2) caused a regression by revealing an inconsistency in
     how sys.path is initialized when executing ‘__main__’ from a
     zipfile, directory, or other import location.  This is considered a
     potential security issue, as it may lead to privileged processes
     unexpectedly loading code from user controlled directories in
     situations where that was not previously the case.  The interpreter
     now consistently avoids ever adding the import location’s parent
     directory to ‘sys.path’, and ensures no other ‘sys.path’ entries
     are inadvertently modified when inserting the import location named
     on the command line.  (Originally reported as bpo-29723(3) against
     Python 3.6rc1, but it was missed at the time that the then upcoming
     Python 3.5.4 release would also be affected)

   - bpo-30657(4): Fixed possible integer overflow in
     PyBytes_DecodeEscape, CVE 2017-1000158(5).  Original patch by Jay
     Bosamiya; rebased to Python 3 by Miro Hrončok.

   - bpo-30947(6): Upgrade libexpat embedded copy from version 2.2.1 to
     2.2.3 to get security fixes.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32551

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29139

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29723

   (4) https://bugs.python.org/issue?@action=redirect&bpo=30657

   (5) https://www.cve.org/CVERecord?id=CVE-2017-1000158

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30947


File: python.info,  Node: Core and Builtins<186>,  Next: Library<189>,  Prev: Security<57>,  Up: Python 3 5 5 release candidate 1

1.24.98.2 Core and Builtins
...........................

   - bpo-31095(1): Fix potential crash during GC caused by ‘tp_dealloc’
     which doesn’t call ‘PyObject_GC_UnTrack()’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=31095


File: python.info,  Node: Library<189>,  Prev: Core and Builtins<186>,  Up: Python 3 5 5 release candidate 1

1.24.98.3 Library
.................

   - bpo-32072(1): Fixed issues with binary plists: Fixed saving
     bytearrays.  Identical objects will be saved only once.  Equal
     references will be load as identical objects.  Added support for
     saving and loading recursive data structures.

   - bpo-31170(2): expat: Update libexpat from 2.2.3 to 2.2.4.  Fix
     copying of partial characters for UTF-8 input (libexpat bug 115):
     ‘https://github.com/libexpat/libexpat/issues/115’

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=32072

   (2) https://bugs.python.org/issue?@action=redirect&bpo=31170


File: python.info,  Node: Python 3 5 4 final,  Next: Python 3 5 4 release candidate 1,  Prev: Python 3 5 5 release candidate 1,  Up: Changelog

1.24.99 Python 3.5.4 final
--------------------------

'Release date: 2017-08-07'

* Menu:

* Library: Library<190>.


File: python.info,  Node: Library<190>,  Up: Python 3 5 4 final

1.24.99.1 Library
.................

   - bpo-30119(1): ftplib.FTP.putline() now throws ValueError on
     commands that contains CR or LF. Patch by Donghee Na.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30119


File: python.info,  Node: Python 3 5 4 release candidate 1,  Next: Python 3 5 3 final,  Prev: Python 3 5 4 final,  Up: Changelog

1.24.100 Python 3.5.4 release candidate 1
-----------------------------------------

'Release date: 2017-07-23'

* Menu:

* Security: Security<58>.
* Core and Builtins: Core and Builtins<187>.
* Library: Library<191>.
* Documentation: Documentation<77>.
* Tests: Tests<78>.
* Build: Build<89>.
* Windows: Windows<76>.
* C API: C API<75>.


File: python.info,  Node: Security<58>,  Next: Core and Builtins<187>,  Up: Python 3 5 4 release candidate 1

1.24.100.1 Security
...................

   - bpo-30730(1): Prevent environment variables injection in subprocess
     on Windows.  Prevent passing other environment variables and
     command arguments.

   - bpo-30694(2): Upgrade expat copy from 2.2.0 to 2.2.1 to get fixes
     of multiple security vulnerabilities including: CVE 2017-9233(3)
     (External entity infinite loop DoS), CVE 2016-9063(4) (Integer
     overflow, re-fix), CVE 2016-0718(5) (Fix regression bugs from
     2.2.0’s fix to CVE 2016-0718(6)) and CVE 2012-0876(7) (Counter hash
     flooding with SipHash).  Note: the CVE 2016-5300(8) (Use
     os-specific entropy sources like getrandom) doesn’t impact Python,
     since Python already gets entropy from the OS to set the expat
     secret using ‘XML_SetHashSalt()’.

   - bpo-30500(9): Fix urllib.parse.splithost() to correctly parse
     fragments.  For example, ‘splithost('//127.0.0.1#@evil.com/')’ now
     correctly returns the ‘127.0.0.1’ host, instead of treating
     ‘@evil.com’ as the host in an authentication (‘login@host’).

   - bpo-29591(10): Update expat copy from 2.1.1 to 2.2.0 to get fixes
     of CVE 2016-0718(11) and CVE 2016-4472(12).  See
     ‘https://sourceforge.net/p/expat/bugs/537/’ for more information.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30730

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30694

   (3) https://www.cve.org/CVERecord?id=CVE-2017-9233

   (4) https://www.cve.org/CVERecord?id=CVE-2016-9063

   (5) https://www.cve.org/CVERecord?id=CVE-2016-0718

   (6) https://www.cve.org/CVERecord?id=CVE-2016-0718

   (7) https://www.cve.org/CVERecord?id=CVE-2012-0876

   (8) https://www.cve.org/CVERecord?id=CVE-2016-5300

   (9) https://bugs.python.org/issue?@action=redirect&bpo=30500

   (10) https://bugs.python.org/issue?@action=redirect&bpo=29591

   (11) https://www.cve.org/CVERecord?id=CVE-2016-0718

   (12) https://www.cve.org/CVERecord?id=CVE-2016-4472


File: python.info,  Node: Core and Builtins<187>,  Next: Library<191>,  Prev: Security<58>,  Up: Python 3 5 4 release candidate 1

1.24.100.2 Core and Builtins
............................

   - bpo-30876(1): Relative import from unloaded package now reimports
     the package instead of failing with SystemError.  Relative import
     from non-package now fails with ImportError rather than
     SystemError.

   - bpo-30765(2): Avoid blocking in pthread_mutex_lock() when
     PyThread_acquire_lock() is asked not to block.

   - bpo-27945(3): Fixed various segfaults with dict when input
     collections are mutated during searching, inserting or comparing.
     Based on patches by Duane Griffin and Tim Mitchell.

   - bpo-25794(4): Fixed type.__setattr__() and type.__delattr__() for
     non-interned attribute names.  Based on patch by Eryk Sun.

   - bpo-29935(5): Fixed error messages in the index() method of tuple,
     list and deque when pass indices of wrong type.

   - bpo-28876(6): ‘bool(range)’ works even if ‘len(range)’ raises *note
     OverflowError: a83.

   - bpo-29600(7): Fix wrapping coroutine return values in
     StopIteration.

   - bpo-29537(8): Restore runtime compatibility with bytecode files
     generated by CPython 3.5.0 to 3.5.2, and adjust the eval loop to
     avoid the problems that could be caused by the malformed variant of
     the BUILD_MAP_UNPACK_WITH_CALL opcode that they may contain.  Patch
     by Petr Viktorin, Serhiy Storchaka, and Nick Coghlan.

   - bpo-28598(9): Support __rmod__ for subclasses of str being called
     before str.__mod__.  Patch by Martijn Pieters.

   - bpo-29602(10): Fix incorrect handling of signed zeros in complex
     constructor for complex subclasses and for inputs having a
     __complex__ method.  Patch by Serhiy Storchaka.

   - bpo-29347(11): Fixed possibly dereferencing undefined pointers when
     creating weakref objects.

   - bpo-29438(12): Fixed use-after-free problem in key sharing dict.

   - bpo-29319(13): Prevent RunMainFromImporter overwriting sys.path[0].

   - bpo-29337(14): Fixed possible BytesWarning when compare the code
     objects.  Warnings could be emitted at compile time.

   - bpo-29478(15): If max_line_length=None is specified while using the
     Compat32 policy, it is no longer ignored.  Patch by Mircea Cosbuc.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30876

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30765

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27945

   (4) https://bugs.python.org/issue?@action=redirect&bpo=25794

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29935

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28876

   (7) https://bugs.python.org/issue?@action=redirect&bpo=29600

   (8) https://bugs.python.org/issue?@action=redirect&bpo=29537

   (9) https://bugs.python.org/issue?@action=redirect&bpo=28598

   (10) https://bugs.python.org/issue?@action=redirect&bpo=29602

   (11) https://bugs.python.org/issue?@action=redirect&bpo=29347

   (12) https://bugs.python.org/issue?@action=redirect&bpo=29438

   (13) https://bugs.python.org/issue?@action=redirect&bpo=29319

   (14) https://bugs.python.org/issue?@action=redirect&bpo=29337

   (15) https://bugs.python.org/issue?@action=redirect&bpo=29478


File: python.info,  Node: Library<191>,  Next: Documentation<77>,  Prev: Core and Builtins<187>,  Up: Python 3 5 4 release candidate 1

1.24.100.3 Library
..................

   - bpo-29403(1): Fix ‘unittest.mock’’s autospec to not fail on
     method-bound builtin functions.  Patch by Aaron Gallagher.

   - bpo-30961(2): Fix decrementing a borrowed reference in tracemalloc.

   - bpo-30886(3): Fix multiprocessing.Queue.join_thread(): it now waits
     until the thread completes, even if the thread was started by the
     same process which created the queue.

   - bpo-29854(4): Fix segfault in readline when using readline’s
     history-size option.  Patch by Nir Soffer.

   - bpo-30807(5): signal.setitimer() may disable the timer when passed
     a tiny value.  Tiny values (such as 1e-6) are valid non-zero values
     for setitimer(), which is specified as taking
     microsecond-resolution intervals.  However, on some platform, our
     conversion routine could convert 1e-6 into a zero interval,
     therefore disabling the timer instead of (re-)scheduling it.

   - bpo-30441(6): Fix bug when modifying os.environ while iterating
     over it

   - bpo-30532(7): Fix email header value parser dropping folding white
     space in certain cases.

   - bpo-29169(8): Update zlib to 1.2.11.

   - bpo-30879(9): os.listdir() and os.scandir() now emit bytes names
     when called with bytes-like argument.

   - bpo-30746(10): Prohibited the “=” character in environment variable
     names in ‘os.putenv()’ and ‘os.spawn*()’.

   - bpo-29755(11): Fixed the lgettext() family of functions in the
     gettext module.  They now always return bytes.

   - bpo-30645(12): Fix path calculation in imp.load_package(), fixing
     it for cases when a package is only shipped with bytecodes.  Patch
     by Alexandru Ardelean.

   - bpo-23890(13): unittest.TestCase.assertRaises() now manually breaks
     a reference cycle to not keep objects alive longer than expected.

   - bpo-30149(14): inspect.signature() now supports callables with
     variable-argument parameters wrapped with partialmethod.  Patch by
     Donghee Na.

   - bpo-29931(15): Fixed comparison check for ipaddress.ip_interface
     objects.  Patch by Sanjay Sundaresan.

   - bpo-24484(16): Avoid race condition in multiprocessing cleanup.

   - bpo-28994(17): The traceback no longer displayed for SystemExit
     raised in a callback registered by atexit.

   - bpo-30508(18): Don’t log exceptions if Task/Future «cancel()»
     method was called.

   - bpo-28556(19): Updates to typing module: Add generic
     AsyncContextManager, add support for ContextManager on all
     versions.  Original PRs by Jelle Zijlstra and Ivan Levkivskyi

   - bpo-29870(20): Fix ssl sockets leaks when connection is aborted in
     asyncio/ssl implementation.  Patch by Michaël Sghaïer.

   - bpo-29743(21): Closing transport during handshake process leaks
     open socket.  Patch by Nikolay Kim

   - bpo-27585(22): Fix waiter cancellation in asyncio.Lock.  Patch by
     Mathieu Sornay.

   - bpo-30418(23): On Windows, subprocess.Popen.communicate() now also
     ignore EINVAL on stdin.write() if the child process is still
     running but closed the pipe.

   - bpo-30378(24): Fix the problem that logging.handlers.SysLogHandler
     cannot handle IPv6 addresses.

   - bpo-29960(25): Preserve generator state when
     _random.Random.setstate() raises an exception.  Patch by Bryan
     Olson.

   - bpo-30414(26): multiprocessing.Queue._feed background running
     thread do not break from main loop on exception.

   - bpo-30003(27): Fix handling escape characters in HZ codec.  Based
     on patch by Ma Lin.

   - bpo-30301(28): Fix AttributeError when using SimpleQueue.empty()
     under 'spawn' and 'forkserver' start methods.

   - bpo-30329(29): imaplib and poplib now catch the Windows socket
     WSAEINVAL error (code 10022) on shutdown(SHUT_RDWR): An invalid
     operation was attempted.  This error occurs sometimes on SSL
     connections.

   - bpo-30375(30): Warnings emitted when compile a regular expression
     now always point to the line in the user code.  Previously they
     could point into inners of the re module if emitted from inside of
     groups or conditionals.

   - bpo-30048(31): Fixed ‘Task.cancel()’ can be ignored when the task
     is running coroutine and the coroutine returned without any more
     ‘await’.

   - bpo-29990(32): Fix range checking in GB18030 decoder.  Original
     patch by Ma Lin.

   - bpo-26293(33): Change resulted because of zipfile breakage.  (See
     also: bpo-29094(34))

   - bpo-30243(35): Removed the __init__ methods of _json’s scanner and
     encoder.  Misusing them could cause memory leaks or crashes.  Now
     scanner and encoder objects are completely initialized in the
     __new__ methods.

   - bpo-30185(36): Avoid KeyboardInterrupt tracebacks in forkserver
     helper process when Ctrl-C is received.

   - bpo-28556(37): Various updates to typing module: add
     typing.NoReturn type, use WrapperDescriptorType, minor bug-fixes.
     Original PRs by Jim Fasarakis-Hilliard and Ivan Levkivskyi.

   - bpo-30205(38): Fix getsockname() for unbound AF_UNIX sockets on
     Linux.

   - bpo-30070(39): Fixed leaks and crashes in errors handling in the
     parser module.

   - bpo-30061(40): Fixed crashes in IOBase methods __next__() and
     readlines() when readline() or __next__() respectively return
     non-sizeable object.  Fixed possible other errors caused by not
     checking results of PyObject_Size(), PySequence_Size(), or
     PyMapping_Size().

   - bpo-30068(41): _io._IOBase.readlines will check if it’s closed
     first when hint is present.

   - bpo-29694(42): Fixed race condition in pathlib mkdir with flags
     parents=True.  Patch by Armin Rigo.

   - bpo-29692(43): Fixed arbitrary unchaining of RuntimeError
     exceptions in contextlib.contextmanager.  Patch by Siddharth
     Velankar.

   - bpo-29998(44): Pickling and copying ImportError now preserves name
     and path attributes.

   - bpo-29942(45): Fix a crash in itertools.chain.from_iterable when
     encountering long runs of empty iterables.

   - bpo-27863(46): Fixed multiple crashes in ElementTree caused by race
     conditions and wrong types.

   - bpo-28699(47): Fixed a bug in pools in multiprocessing.pool that
     raising an exception at the very first of an iterable may swallow
     the exception or make the program hang.  Patch by Davin Potts and
     Xiang Zhang.

   - bpo-25803(48): Avoid incorrect errors raised by
     Path.mkdir(exist_ok=True) when the OS gives priority to errors such
     as EACCES over EEXIST.

   - bpo-29861(49): Release references to tasks, their arguments and
     their results as soon as they are finished in multiprocessing.Pool.

   - bpo-29884(50): faulthandler: Restore the old sigaltstack during
     teardown.  Patch by Christophe Zeitouny.

   - bpo-25455(51): Fixed crashes in repr of recursive buffered
     file-like objects.

   - bpo-29800(52): Fix crashes in partial.__repr__ if the keys of
     partial.keywords are not strings.  Patch by Michael Seifert.

   - bpo-29742(53): get_extra_info() raises exception if get called on
     closed ssl transport.  Patch by Nikolay Kim.

   - bpo-8256(54): Fixed possible failing or crashing input() if
     attributes «encoding» or «errors» of sys.stdin or sys.stdout are
     not set or are not strings.

   - bpo-28298(55): Fix a bug that prevented array “Q”, “L” and “I” from
     accepting big intables (objects that have __int__) as elements.
     Patch by Oren Milman.

   - bpo-29615(56): SimpleXMLRPCDispatcher no longer chains KeyError (or
     any other exception) to exception(s) raised in the dispatched
     methods.  Patch by Petr Motejlek.

   - bpo-29704(57): asyncio.subprocess.SubprocessStreamProtocol no
     longer closes before all pipes are closed.

   - bpo-29703(58): Fix asyncio to support instantiation of new event
     loops in child processes.

   - bpo-29376(59): Fix assertion error in
     threading._DummyThread.is_alive().

   - bpo-29110(60): Fix file object leak in aifc.open() when file is
     given as a filesystem path and is not in valid AIFF format.  Patch
     by Anthony Zhang.

   - bpo-28961(61): Fix unittest.mock._Call helper: don’t ignore the
     name parameter anymore.  Patch written by Jiajun Huang.

   - bpo-29532(62): Altering a kwarg dictionary passed to
     functools.partial() no longer affects a partial object after
     creation.

   - bpo-28556(63): Various updates to typing module: typing.Counter,
     typing.ChainMap, improved ABC caching, etc.  Original PRs by Jelle
     Zijlstra, Ivan Levkivskyi, Manuel Krebber, and Łukasz Langa.

   - bpo-29100(64): Fix datetime.fromtimestamp() regression introduced
     in Python 3.6.0: check minimum and maximum years.

   - bpo-29519(65): Fix weakref spewing exceptions during interpreter
     shutdown when used with a rare combination of multiprocessing and
     custom codecs.

   - bpo-29416(66): Prevent infinite loop in pathlib.Path.mkdir

   - bpo-29444(67): Fixed out-of-bounds buffer access in the group()
     method of the match object.  Based on patch by WGH.

   - bpo-29335(68): Fix subprocess.Popen.wait() when the child process
     has exited to a stopped instead of terminated state (ex: when under
     ptrace).

   - bpo-29290(69): Fix a regression in argparse that help messages
     would wrap at non-breaking spaces.

   - bpo-28735(70): Fixed the comparison of mock.MagickMock with
     mock.ANY.

   - bpo-29011(71): Fix an important omission by adding Deque to the
     typing module.

   - bpo-29219(72): Fixed infinite recursion in the repr of
     uninitialized ctypes.CDLL instances.

   - bpo-28969(73): Fixed race condition in C implementation of
     functools.lru_cache.  KeyError could be raised when cached function
     with full cache was simultaneously called from different threads
     with the same uncached arguments.

   - bpo-29142(74): In urllib.request, suffixes in no_proxy environment
     variable with leading dots could match related hostnames again
     (e.g.  .b.c matches a.b.c).  Patch by Milan Oberkirch.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29403

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30961

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30886

   (4) https://bugs.python.org/issue?@action=redirect&bpo=29854

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30807

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30441

   (7) https://bugs.python.org/issue?@action=redirect&bpo=30532

   (8) https://bugs.python.org/issue?@action=redirect&bpo=29169

   (9) https://bugs.python.org/issue?@action=redirect&bpo=30879

   (10) https://bugs.python.org/issue?@action=redirect&bpo=30746

   (11) https://bugs.python.org/issue?@action=redirect&bpo=29755

   (12) https://bugs.python.org/issue?@action=redirect&bpo=30645

   (13) https://bugs.python.org/issue?@action=redirect&bpo=23890

   (14) https://bugs.python.org/issue?@action=redirect&bpo=30149

   (15) https://bugs.python.org/issue?@action=redirect&bpo=29931

   (16) https://bugs.python.org/issue?@action=redirect&bpo=24484

   (17) https://bugs.python.org/issue?@action=redirect&bpo=28994

   (18) https://bugs.python.org/issue?@action=redirect&bpo=30508

   (19) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (20) https://bugs.python.org/issue?@action=redirect&bpo=29870

   (21) https://bugs.python.org/issue?@action=redirect&bpo=29743

   (22) https://bugs.python.org/issue?@action=redirect&bpo=27585

   (23) https://bugs.python.org/issue?@action=redirect&bpo=30418

   (24) https://bugs.python.org/issue?@action=redirect&bpo=30378

   (25) https://bugs.python.org/issue?@action=redirect&bpo=29960

   (26) https://bugs.python.org/issue?@action=redirect&bpo=30414

   (27) https://bugs.python.org/issue?@action=redirect&bpo=30003

   (28) https://bugs.python.org/issue?@action=redirect&bpo=30301

   (29) https://bugs.python.org/issue?@action=redirect&bpo=30329

   (30) https://bugs.python.org/issue?@action=redirect&bpo=30375

   (31) https://bugs.python.org/issue?@action=redirect&bpo=30048

   (32) https://bugs.python.org/issue?@action=redirect&bpo=29990

   (33) https://bugs.python.org/issue?@action=redirect&bpo=26293

   (34) https://bugs.python.org/issue?@action=redirect&bpo=29094

   (35) https://bugs.python.org/issue?@action=redirect&bpo=30243

   (36) https://bugs.python.org/issue?@action=redirect&bpo=30185

   (37) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (38) https://bugs.python.org/issue?@action=redirect&bpo=30205

   (39) https://bugs.python.org/issue?@action=redirect&bpo=30070

   (40) https://bugs.python.org/issue?@action=redirect&bpo=30061

   (41) https://bugs.python.org/issue?@action=redirect&bpo=30068

   (42) https://bugs.python.org/issue?@action=redirect&bpo=29694

   (43) https://bugs.python.org/issue?@action=redirect&bpo=29692

   (44) https://bugs.python.org/issue?@action=redirect&bpo=29998

   (45) https://bugs.python.org/issue?@action=redirect&bpo=29942

   (46) https://bugs.python.org/issue?@action=redirect&bpo=27863

   (47) https://bugs.python.org/issue?@action=redirect&bpo=28699

   (48) https://bugs.python.org/issue?@action=redirect&bpo=25803

   (49) https://bugs.python.org/issue?@action=redirect&bpo=29861

   (50) https://bugs.python.org/issue?@action=redirect&bpo=29884

   (51) https://bugs.python.org/issue?@action=redirect&bpo=25455

   (52) https://bugs.python.org/issue?@action=redirect&bpo=29800

   (53) https://bugs.python.org/issue?@action=redirect&bpo=29742

   (54) https://bugs.python.org/issue?@action=redirect&bpo=8256

   (55) https://bugs.python.org/issue?@action=redirect&bpo=28298

   (56) https://bugs.python.org/issue?@action=redirect&bpo=29615

   (57) https://bugs.python.org/issue?@action=redirect&bpo=29704

   (58) https://bugs.python.org/issue?@action=redirect&bpo=29703

   (59) https://bugs.python.org/issue?@action=redirect&bpo=29376

   (60) https://bugs.python.org/issue?@action=redirect&bpo=29110

   (61) https://bugs.python.org/issue?@action=redirect&bpo=28961

   (62) https://bugs.python.org/issue?@action=redirect&bpo=29532

   (63) https://bugs.python.org/issue?@action=redirect&bpo=28556

   (64) https://bugs.python.org/issue?@action=redirect&bpo=29100

   (65) https://bugs.python.org/issue?@action=redirect&bpo=29519

   (66) https://bugs.python.org/issue?@action=redirect&bpo=29416

   (67) https://bugs.python.org/issue?@action=redirect&bpo=29444

   (68) https://bugs.python.org/issue?@action=redirect&bpo=29335

   (69) https://bugs.python.org/issue?@action=redirect&bpo=29290

   (70) https://bugs.python.org/issue?@action=redirect&bpo=28735

   (71) https://bugs.python.org/issue?@action=redirect&bpo=29011

   (72) https://bugs.python.org/issue?@action=redirect&bpo=29219

   (73) https://bugs.python.org/issue?@action=redirect&bpo=28969

   (74) https://bugs.python.org/issue?@action=redirect&bpo=29142


File: python.info,  Node: Documentation<77>,  Next: Tests<78>,  Prev: Library<191>,  Up: Python 3 5 4 release candidate 1

1.24.100.4 Documentation
........................

   - bpo-30176(1): Add missing attribute related constants in curses
     documentation.

   - bpo-26985(2): Add missing info of code object in inspect
     documentation.

   - bpo-28929(3): Link the documentation to its source file on GitHub.

   - bpo-25008(4): Document smtpd.py as effectively deprecated and add a
     pointer to aiosmtpd, a third-party asyncio-based replacement.

   - bpo-26355(5): Add canonical header link on each page to
     corresponding major version of the documentation.  Patch by
     Matthias Bussonnier.

   - bpo-29349(6): Fix Python 2 syntax in code for building the
     documentation.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30176

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26985

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28929

   (4) https://bugs.python.org/issue?@action=redirect&bpo=25008

   (5) https://bugs.python.org/issue?@action=redirect&bpo=26355

   (6) https://bugs.python.org/issue?@action=redirect&bpo=29349


File: python.info,  Node: Tests<78>,  Next: Build<89>,  Prev: Documentation<77>,  Up: Python 3 5 4 release candidate 1

1.24.100.5 Tests
................

   - bpo-30822(1): Fix regrtest command line parser to allow passing -u
     extralargefile to run test_zipfile64.

   - bpo-30383(2): regrtest: Enhance regrtest and backport features from
     the master branch.  Add options: –coverage, –testdir, –list-tests
     (list test files, don’t run them), –list-cases (list test
     identifiers, don’t run them, bpo-30523(3)), –matchfile (load a list
     of test filters from a text file, bpo-30540(4)), –slowest (alias to
     –slow).  Enhance output: add timestamp, test result, currently
     running tests, «Tests result: xxx» summary with total duration,
     etc.  Fix reference leak hunting in regrtest, –huntrleaks: regrtest
     now warms up caches, create explicitly all internal singletons
     which are created on demand to prevent false positives when
     checking for reference leaks.  (bpo-30675(5)).

   - bpo-30357(6): test_thread: setUp() now uses
     support.threading_setup() and support.threading_cleanup() to wait
     until threads complete to avoid random side effects on following
     tests.  Initial patch written by Grzegorz Grzywacz.

   - bpo-28087(7): Skip test_asyncore and test_eintr poll failures on
     macOS. Skip some tests of select.poll when running on macOS due to
     unresolved issues with the underlying system poll function on some
     macOS versions.

   - bpo-30197(8): Enhanced functions swap_attr() and swap_item() in the
     test.support module.  They now work when delete replaced attribute
     or item inside the with statement.  The old value of the attribute
     or item (or None if it doesn’t exist) now will be assigned to the
     target of the «as» clause, if there is one.

   - bpo-29571(9): to match the behaviour of the ‘re.LOCALE’ flag,
     test_re.test_locale_flag now uses
     ‘locale.getpreferredencoding(False)’ to determine the candidate
     encoding for the test regex (allowing it to correctly skip the test
     when the default locale encoding is a multi-byte encoding)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30822

   (2) https://bugs.python.org/issue?@action=redirect&bpo=30383

   (3) https://bugs.python.org/issue?@action=redirect&bpo=30523

   (4) https://bugs.python.org/issue?@action=redirect&bpo=30540

   (5) https://bugs.python.org/issue?@action=redirect&bpo=30675

   (6) https://bugs.python.org/issue?@action=redirect&bpo=30357

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28087

   (8) https://bugs.python.org/issue?@action=redirect&bpo=30197

   (9) https://bugs.python.org/issue?@action=redirect&bpo=29571


File: python.info,  Node: Build<89>,  Next: Windows<76>,  Prev: Tests<78>,  Up: Python 3 5 4 release candidate 1

1.24.100.6 Build
................

   - bpo-29243(1): Prevent unnecessary rebuilding of Python during ‘make
     test’, ‘make install’ and some other make targets when configured
     with ‘--enable-optimizations’.

   - bpo-23404(2): Don’t regenerate generated files based on file
     modification time anymore: the action is now explicit.  Replace
     ‘make touch’ with ‘make regen-all’.

   - bpo-29643(3): Fix ‘--enable-optimization’ didn’t work.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29243

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23404

   (3) https://bugs.python.org/issue?@action=redirect&bpo=29643


File: python.info,  Node: Windows<76>,  Next: C API<75>,  Prev: Build<89>,  Up: Python 3 5 4 release candidate 1

1.24.100.7 Windows
..................

   - bpo-30687(1): Locate msbuild.exe on Windows when building rather
     than vcvarsall.bat

   - bpo-29392(2): Prevent crash when passing invalid arguments into
     msvcrt module.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=30687

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29392


File: python.info,  Node: C API<75>,  Prev: Windows<76>,  Up: Python 3 5 4 release candidate 1

1.24.100.8 C API
................

   - bpo-27867(1): Function PySlice_GetIndicesEx() is replaced with a
     macro if Py_LIMITED_API is set to the value between 0x03050400 and
     0x03060000 (not including) or 0x03060100 or higher.

   - bpo-29083(2): Fixed the declaration of some public API functions.
     PyArg_VaParse() and PyArg_VaParseTupleAndKeywords() were not
     available in limited API. PyArg_ValidateKeywordArguments(),
     PyArg_UnpackTuple() and Py_BuildValue() were not available in
     limited API of version < 3.3 when PY_SSIZE_T_CLEAN is defined.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27867

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29083


File: python.info,  Node: Python 3 5 3 final,  Next: Python 3 5 3 release candidate 1,  Prev: Python 3 5 4 release candidate 1,  Up: Changelog

1.24.101 Python 3.5.3 final
---------------------------

'Release date: 2017-01-17'

There were no code changes between 3.5.3rc1 and 3.5.3 final.


File: python.info,  Node: Python 3 5 3 release candidate 1,  Next: Python 3 5 2 final,  Prev: Python 3 5 3 final,  Up: Changelog

1.24.102 Python 3.5.3 release candidate 1
-----------------------------------------

'Release date: 2017-01-02'

* Menu:

* Security: Security<59>.
* Core and Builtins: Core and Builtins<188>.
* Library: Library<192>.
* IDLE: IDLE<57>.
* C API: C API<76>.
* Documentation: Documentation<78>.
* Tests: Tests<79>.
* Tools/Demos: Tools/Demos<55>.
* Windows: Windows<77>.
* Build: Build<90>.


File: python.info,  Node: Security<59>,  Next: Core and Builtins<188>,  Up: Python 3 5 3 release candidate 1

1.24.102.1 Security
...................

   - bpo-27278(1): Fix os.urandom() implementation using getrandom() on
     Linux.  Truncate size to INT_MAX and loop until we collected enough
     random bytes, instead of casting a directly Py_ssize_t to int.

   - bpo-22636(2): Avoid shell injection problems with
     ctypes.util.find_library().

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27278

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22636


File: python.info,  Node: Core and Builtins<188>,  Next: Library<192>,  Prev: Security<59>,  Up: Python 3 5 3 release candidate 1

1.24.102.2 Core and Builtins
............................

   - bpo-29073(1): bytearray formatting no longer truncates on first
     null byte.

   - bpo-28932(2): Do not include <sys/random.h> if it does not exist.

   - bpo-28147(3): Fix a memory leak in split-table dictionaries:
     setattr() must not convert combined table into split table.

   - bpo-25677(4): Correct the positioning of the syntax error caret for
     indented blocks.  Based on patch by Michael Layzell.

   - bpo-29000(5): Fixed bytes formatting of octals with zero padding in
     alternate form.

   - bpo-28512(6): Fixed setting the offset attribute of SyntaxError by
     PyErr_SyntaxLocationEx() and PyErr_SyntaxLocationObject().

   - bpo-28991(7): functools.lru_cache() was susceptible to an obscure
     reentrancy bug caused by a monkey-patched len() function.

   - bpo-28648(8): Fixed crash in Py_DecodeLocale() in debug build on
     Mac OS X when decode astral characters.  Patch by Xiang Zhang.

   - bpo-19398(9): Extra slash no longer added to sys.path components in
     case of empty compile-time PYTHONPATH components.

   - bpo-28426(10): Fixed potential crash in PyUnicode_AsDecodedObject()
     in debug build.

   - bpo-23782(11): Fixed possible memory leak in _PyTraceback_Add() and
     exception loss in PyTraceBack_Here().

   - bpo-28379(12): Added sanity checks and tests for
     PyUnicode_CopyCharacters().  Patch by Xiang Zhang.

   - bpo-28376(13): The type of long range iterator is now registered as
     Iterator.  Patch by Oren Milman.

   - bpo-28376(14): The constructor of range_iterator now checks that
     step is not 0.  Patch by Oren Milman.

   - bpo-26906(15): Resolving special methods of uninitialized type now
     causes implicit initialization of the type instead of a fail.

   - bpo-18287(16): PyType_Ready() now checks that tp_name is not NULL.
     Original patch by Niklas Koep.

   - bpo-24098(17): Fixed possible crash when AST is changed in process
     of compiling it.

   - bpo-28350(18): String constants with null character no longer
     interned.

   - bpo-26617(19): Fix crash when GC runs during weakref callbacks.

   - bpo-27942(20): String constants now interned recursively in tuples
     and frozensets.

   - bpo-21578(21): Fixed misleading error message when ImportError
     called with invalid keyword args.

   - bpo-28203(22): Fix incorrect type in error message from
     ‘complex(1.0, {2:3})’.  Patch by Soumya Sharma.

   - bpo-27955(23): Fallback on reading /dev/urandom device when the
     getrandom() syscall fails with EPERM, for example when blocked by
     SECCOMP.

   - bpo-28131(24): Fix a regression in zipimport’s compile_source().
     zipimport should use the same optimization level as the
     interpreter.

   - bpo-25221(25): Fix corrupted result from PyLong_FromLong(0) when
     Python is compiled with NSMALLPOSINTS = 0.

   - bpo-25758(26): Prevents zipimport from unnecessarily encoding a
     filename (patch by Eryk Sun)

   - bpo-28189(27): dictitems_contains no longer swallows compare
     errors.  (Patch by Xiang Zhang)

   - bpo-27812(28): Properly clear out a generator’s frame’s
     backreference to the generator to prevent crashes in frame.clear().

   - bpo-27811(29): Fix a crash when a coroutine that has not been
     awaited is finalized with warnings-as-errors enabled.

   - bpo-27587(30): Fix another issue found by PVS-Studio: Null pointer
     check after use of “def” in _PyState_AddModule().  Initial patch by
     Christian Heimes.

   - bpo-26020(31): set literal evaluation order did not match
     documented behaviour.

   - bpo-27782(32): Multi-phase extension module import now correctly
     allows the ‘m_methods’ field to be used to add module level
     functions to instances of non-module types returned from
     ‘Py_create_mod’.  Patch by Xiang Zhang.

   - bpo-27936(33): The round() function accepted a second None argument
     for some types but not for others.  Fixed the inconsistency by
     accepting None for all numeric types.

   - bpo-27487(34): Warn if a submodule argument to «python -m» or
     runpy.run_module() is found in sys.modules after parent packages
     are imported, but before the submodule is executed.

   - bpo-27558(35): Fix a SystemError in the implementation of «raise»
     statement.  In a brand new thread, raise a RuntimeError since there
     is no active exception to reraise.  Patch written by Xiang Zhang.

   - bpo-27419(36): Standard __import__() no longer look up «__import__»
     in globals or builtins for importing submodules or «from import».
     Fixed handling an error of non-string package name.

   - bpo-27083(37): Respect the PYTHONCASEOK environment variable under
     Windows.

   - bpo-27514(38): Make having too many statically nested blocks a
     SyntaxError instead of SystemError.

   - bpo-27473(39): Fixed possible integer overflow in bytes and
     bytearray concatenations.  Patch by Xiang Zhang.

   - bpo-27507(40): Add integer overflow check in bytearray.extend().
     Patch by Xiang Zhang.

   - bpo-27581(41): Don’t rely on wrapping for overflow check in
     PySequence_Tuple().  Patch by Xiang Zhang.

   - bpo-27443(42): __length_hint__() of bytearray iterators no longer
     return a negative integer for a resized bytearray.

   - bpo-27942(43): Fix memory leak in codeobject.c

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29073

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28932

   (3) https://bugs.python.org/issue?@action=redirect&bpo=28147

   (4) https://bugs.python.org/issue?@action=redirect&bpo=25677

   (5) https://bugs.python.org/issue?@action=redirect&bpo=29000

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28512

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28991

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28648

   (9) https://bugs.python.org/issue?@action=redirect&bpo=19398

   (10) https://bugs.python.org/issue?@action=redirect&bpo=28426

   (11) https://bugs.python.org/issue?@action=redirect&bpo=23782

   (12) https://bugs.python.org/issue?@action=redirect&bpo=28379

   (13) https://bugs.python.org/issue?@action=redirect&bpo=28376

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28376

   (15) https://bugs.python.org/issue?@action=redirect&bpo=26906

   (16) https://bugs.python.org/issue?@action=redirect&bpo=18287

   (17) https://bugs.python.org/issue?@action=redirect&bpo=24098

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28350

   (19) https://bugs.python.org/issue?@action=redirect&bpo=26617

   (20) https://bugs.python.org/issue?@action=redirect&bpo=27942

   (21) https://bugs.python.org/issue?@action=redirect&bpo=21578

   (22) https://bugs.python.org/issue?@action=redirect&bpo=28203

   (23) https://bugs.python.org/issue?@action=redirect&bpo=27955

   (24) https://bugs.python.org/issue?@action=redirect&bpo=28131

   (25) https://bugs.python.org/issue?@action=redirect&bpo=25221

   (26) https://bugs.python.org/issue?@action=redirect&bpo=25758

   (27) https://bugs.python.org/issue?@action=redirect&bpo=28189

   (28) https://bugs.python.org/issue?@action=redirect&bpo=27812

   (29) https://bugs.python.org/issue?@action=redirect&bpo=27811

   (30) https://bugs.python.org/issue?@action=redirect&bpo=27587

   (31) https://bugs.python.org/issue?@action=redirect&bpo=26020

   (32) https://bugs.python.org/issue?@action=redirect&bpo=27782

   (33) https://bugs.python.org/issue?@action=redirect&bpo=27936

   (34) https://bugs.python.org/issue?@action=redirect&bpo=27487

   (35) https://bugs.python.org/issue?@action=redirect&bpo=27558

   (36) https://bugs.python.org/issue?@action=redirect&bpo=27419

   (37) https://bugs.python.org/issue?@action=redirect&bpo=27083

   (38) https://bugs.python.org/issue?@action=redirect&bpo=27514

   (39) https://bugs.python.org/issue?@action=redirect&bpo=27473

   (40) https://bugs.python.org/issue?@action=redirect&bpo=27507

   (41) https://bugs.python.org/issue?@action=redirect&bpo=27581

   (42) https://bugs.python.org/issue?@action=redirect&bpo=27443

   (43) https://bugs.python.org/issue?@action=redirect&bpo=27942


File: python.info,  Node: Library<192>,  Next: IDLE<57>,  Prev: Core and Builtins<188>,  Up: Python 3 5 3 release candidate 1

1.24.102.3 Library
..................

   - bpo-15812(1): inspect.getframeinfo() now correctly shows the first
     line of a context.  Patch by Sam Breese.

   - bpo-29094(2): Offsets in a ZIP file created with extern file object
     and modes «w» and «x» now are relative to the start of the file.

   - bpo-13051(3): Fixed recursion errors in large or resized
     curses.textpad.Textbox.  Based on patch by Tycho Andersen.

   - bpo-29119(4): Fix weakrefs in the pure python version of
     collections.OrderedDict move_to_end() method.  Contributed by Andra
     Bogildea.

   - bpo-9770(5): curses.ascii predicates now work correctly with
     negative integers.

   - bpo-28427(6): old keys should not remove new values from
     WeakValueDictionary when collecting from another thread.

   - bpo-28923(7): Remove editor artifacts from Tix.py.

   - bpo-28871(8): Fixed a crash when deallocate deep ElementTree.

   - bpo-19542(9): Fix bugs in WeakValueDictionary.setdefault() and
     WeakValueDictionary.pop() when a GC collection happens in another
     thread.

   - bpo-20191(10): Fixed a crash in resource.prlimit() when pass a
     sequence that doesn’t own its elements as limits.

   - bpo-28779(11): multiprocessing.set_forkserver_preload() would crash
     the forkserver process if a preloaded module instantiated some
     multiprocessing objects such as locks.

   - bpo-28847(12): dbm.dumb now supports reading read-only files and no
     longer writes the index file when it is not changed.

   - bpo-25659(13): In ctypes, prevent a crash calling the from_buffer()
     and from_buffer_copy() methods on abstract classes like Array.

   - bpo-28732(14): Fix crash in os.spawnv() with no elements in args

   - bpo-28485(15): Always raise ValueError for negative
     compileall.compile_dir(workers=…) parameter, even when
     multithreading is unavailable.

   - bpo-28387(16): Fixed possible crash in _io.TextIOWrapper
     deallocator when the garbage collector is invoked in other thread.
     Based on patch by Sebastian Cufre.

   - bpo-27517(17): LZMA compressor and decompressor no longer raise
     exceptions if given empty data twice.  Patch by Benjamin Fogle.

   - bpo-28549(18): Fixed segfault in curses’s addch() with ncurses6.

   - bpo-28449(19): tarfile.open() with mode «r» or «r:» now tries to
     open a tar file with compression before trying to open it without
     compression.  Otherwise it had 50% chance failed with
     ignore_zeros=True.

   - bpo-23262(20): The webbrowser module now supports Firefox 36+ and
     derived browsers.  Based on patch by Oleg Broytman.

   - bpo-27939(21): Fixed bugs in tkinter.ttk.LabeledScale and
     tkinter.Scale caused by representing the scale as float value
     internally in Tk.  tkinter.IntVar now works if float value is set
     to underlying Tk variable.

   - bpo-28255(22): calendar.TextCalendar().prmonth() no longer prints a
     space at the start of new line after printing a month’s calendar.
     Patch by Xiang Zhang.

   - bpo-20491(23): The textwrap.TextWrapper class now honors
     non-breaking spaces.  Based on patch by Kaarle Ritvanen.

   - bpo-28353(24): os.fwalk() no longer fails on broken links.

   - bpo-25464(25): Fixed HList.header_exists() in tkinter.tix module by
     addin a workaround to Tix library bug.

   - bpo-28488(26): shutil.make_archive() no longer add entry «./» to
     ZIP archive.

   - bpo-24452(27): Make webbrowser support Chrome on Mac OS X.

   - bpo-20766(28): Fix references leaked by pdb in the handling of
     SIGINT handlers.

   - bpo-26293(29): Fixed writing ZIP files that starts not from the
     start of the file.  Offsets in ZIP file now are relative to the
     start of the archive in conforming to the specification.

   - bpo-28321(30): Fixed writing non-BMP characters with binary format
     in plistlib.

   - bpo-28322(31): Fixed possible crashes when unpickle itertools
     objects from incorrect pickle data.  Based on patch by John Leitch.

   - Fix possible integer overflows and crashes in the mmap module with
     unusual usage patterns.

   - bpo-1703178(32): Fix the ability to pass the –link-objects option
     to the distutils build_ext command.

   - bpo-28253(33): Fixed calendar functions for extreme months: 0001-01
     and 9999-12.  Methods itermonthdays() and itermonthdays2() are
     reimplemented so that they don’t call itermonthdates() which can
     cause datetime.date under/overflow.

   - bpo-28275(34): Fixed possible use after free in the decompress()
     methods of the LZMADecompressor and BZ2Decompressor classes.
     Original patch by John Leitch.

   - bpo-27897(35): Fixed possible crash in
     sqlite3.Connection.create_collation() if pass invalid string-like
     object as a name.  Patch by Xiang Zhang.

   - bpo-18893(36): Fix invalid exception handling in
     Lib/ctypes/macholib/dyld.py.  Patch by Madison May.

   - bpo-27611(37): Fixed support of default root window in the
     tkinter.tix module.

   - bpo-27348(38): In the traceback module, restore the formatting of
     exception messages like «Exception: None».  This fixes a regression
     introduced in 3.5a2.

   - bpo-25651(39): Allow false values to be used for msg parameter of
     subTest().

   - bpo-27932(40): Prevent memory leak in win32_ver().

   - Fix UnboundLocalError in socket._sendfile_use_sendfile.

   - bpo-28075(41): Check for ERROR_ACCESS_DENIED in Windows
     implementation of os.stat().  Patch by Eryk Sun.

   - bpo-25270(42): Prevent codecs.escape_encode() from raising
     SystemError when an empty bytestring is passed.

   - bpo-28181(43): Get antigravity over HTTPS. Patch by Kaartic
     Sivaraam.

   - bpo-25895(44): Enable WebSocket URL schemes in
     urllib.parse.urljoin.  Patch by Gergely Imreh and Markus
     Holtermann.

   - bpo-27599(45): Fixed buffer overrun in binascii.b2a_qp() and
     binascii.a2b_qp().

   - bpo-19003(46): m email.generator now replaces only ‘\r’ and/or ‘\n’
     line endings, per the RFC, instead of all unicode line endings.

   - bpo-28019(47): itertools.count() no longer rounds non-integer step
     in range between 1.0 and 2.0 to 1.

   - bpo-25969(48): Update the lib2to3 grammar to handle the unpacking
     generalizations added in 3.5.

   - bpo-14977(49): mailcap now respects the order of the lines in the
     mailcap files («first match»), as required by RFC 1542.  Patch by
     Michael Lazar.

   - bpo-24594(50): Validates persist parameter when opening MSI
     database

   - bpo-17582(51): xml.etree.ElementTree nows preserves whitespaces in
     attributes (Patch by Duane Griffin.  Reviewed and approved by
     Stefan Behnel.)

   - bpo-28047(52): Fixed calculation of line length used for the base64
     CTE in the new email policies.

   - bpo-27445(53): Don’t pass str(_charset) to MIMEText.set_payload().
     Patch by Claude Paroz.

   - bpo-22450(54): urllib now includes an ‘Accept: */*’ header among
     the default headers.  This makes the results of REST API requests
     more consistent and predictable especially when proxy servers are
     involved.

   - lib2to3.pgen3.driver.load_grammar() now creates a stable cache file
     between runs given the same Grammar.txt input regardless of the
     hash randomization setting.

   - bpo-27570(55): Avoid zero-length memcpy() etc calls with null
     source pointers in the «ctypes» and «array» modules.

   - bpo-22233(56): Break email header lines 'only' on the RFC specified
     CR and LF characters, not on arbitrary unicode line breaks.  This
     also fixes a bug in HTTP header parsing.

   - bpo-27988(57): Fix email iter_attachments incorrect mutation of
     payload list.

   - bpo-27691(58): Fix ssl module’s parsing of GEN_RID subject
     alternative name fields in X.509 certs.

   - bpo-27850(59): Remove 3DES from ssl module’s default cipher list to
     counter measure sweet32 attack ( CVE 2016-2183(60)).

   - bpo-27766(61): Add ChaCha20 Poly1305 to ssl module’s default cipher
     list.  (Required OpenSSL 1.1.0 or LibreSSL).

   - bpo-26470(62): Port ssl and hashlib module to OpenSSL 1.1.0.

   - Remove support for passing a file descriptor to os.access.  It
     never worked but previously didn’t raise.

   - bpo-12885(63): Fix error when distutils encounters symlink.

   - bpo-27881(64): Fixed possible bugs when setting
     sqlite3.Connection.isolation_level.  Based on patch by Xiang Zhang.

   - bpo-27861(65): Fixed a crash in sqlite3.Connection.cursor() when a
     factory creates not a cursor.  Patch by Xiang Zhang.

   - bpo-19884(66): Avoid spurious output on OS X with Gnu Readline.

   - bpo-27706(67): Restore deterministic behavior of
     random.Random().seed() for string seeds using seeding version 1.
     Allows sequences of calls to random() to exactly match those
     obtained in Python 2.  Patch by Nofar Schnider.

   - bpo-10513(68): Fix a regression in Connection.commit().  Statements
     should not be reset after a commit.

   - A new version of typing.py from ‘https://github.com/python/typing’:
     Collection (only for 3.6) (bpo-27598(69)).  Add FrozenSet to
     __all__ (upstream #261).  Fix crash in _get_type_vars() (upstream
     #259).  Remove the dict constraint in ForwardRef._eval_type
     (upstream #252).

   - bpo-27539(70): Fix unnormalised ‘Fraction.__pow__’ result in the
     case of negative exponent and negative base.

   - bpo-21718(71): cursor.description is now available for queries
     using CTEs.

   - bpo-2466(72): posixpath.ismount now correctly recognizes mount
     points which the user does not have permission to access.

   - bpo-27773(73): Correct some memory management errors
     server_hostname in _ssl.wrap_socket().

   - bpo-26750(74): unittest.mock.create_autospec() now works properly
     for subclasses of property() and other data descriptors.

   - In the curses module, raise an error if window.getstr() or
     window.instr() is passed a negative value.

   - bpo-27783(75): Fix possible usage of uninitialized memory in
     operator.methodcaller.

   - bpo-27774(76): Fix possible Py_DECREF on unowned object in _sre.

   - bpo-27760(77): Fix possible integer overflow in binascii.b2a_qp.

   - bpo-27758(78): Fix possible integer overflow in the _csv module for
     large record lengths.

   - bpo-27568(79): Prevent HTTPoxy attack ( CVE 2016-1000110(80)).
     Ignore the HTTP_PROXY variable when REQUEST_METHOD environment is
     set, which indicates that the script is in CGI mode.

   - bpo-27656(81): Do not assume sched.h defines any SCHED_* constants.

   - bpo-27130(82): In the «zlib» module, fix handling of large buffers
     (typically 4 GiB) when compressing and decompressing.  Previously,
     inputs were limited to 4 GiB, and compression and decompression
     operations did not properly handle results of 4 GiB.

   - bpo-27533(83): Release GIL in nt._isdir

   - bpo-17711(84): Fixed unpickling by the persistent ID with protocol
     0.  Original patch by Alexandre Vassalotti.

   - bpo-27522(85): Avoid an unintentional reference cycle in
     email.feedparser.

   - bpo-26844(86): Fix error message for imp.find_module() to refer to
     “path” instead of “name”.  Patch by Lev Maximov.

   - bpo-23804(87): Fix SSL zero-length recv() calls to not block and
     not raise an error about unclean EOF.

   - bpo-27466(88): Change time format returned by
     http.cookie.time2netscape, confirming the netscape cookie format
     and making it consistent with documentation.

   - bpo-26664(89): Fix activate.fish by removing mis-use of ‘$’.

   - bpo-22115(90): Fixed tracing Tkinter variables: trace_vdelete()
     with wrong mode no longer break tracing, trace_vinfo() now always
     returns a list of pairs of strings, tracing in the «u» mode now
     works.

   - Fix a scoping issue in importlib.util.LazyLoader which triggered an
     UnboundLocalError when lazy-loading a module that was already put
     into sys.modules.

   - bpo-27079(91): Fixed curses.ascii functions isblank(), iscntrl()
     and ispunct().

   - bpo-26754(92): Some functions (compile() etc) accepted a filename
     argument encoded as an iterable of integers.  Now only strings and
     byte-like objects are accepted.

   - bpo-27048(93): Prevents distutils failing on Windows when
     environment variables contain non-ASCII characters

   - bpo-27330(94): Fixed possible leaks in the ctypes module.

   - bpo-27238(95): Got rid of bare excepts in the turtle module.
     Original patch by Jelle Zijlstra.

   - bpo-27122(96): When an exception is raised within the context being
     managed by a contextlib.ExitStack() and one of the exit stack
     generators catches and raises it in a chain, do not re-raise the
     original exception when exiting, let the new chained one through.
     This avoids the PEP 479(97) bug described in issue25782.

   - bpo-26386(98): Fixed ttk.TreeView selection operations with item
     id’s containing spaces.

   - bpo-16182(99): Fix various functions in the «readline» module to
     use the locale encoding, and fix get_begidx() and get_endidx() to
     return code point indexes.

   - bpo-27392(100): Add loop.connect_accepted_socket().  Patch by Jim
     Fulton.

   - bpo-27930(101): Improved behaviour of
     logging.handlers.QueueListener.  Thanks to Paulo Andrade and Petr
     Viktorin for the analysis and patch.

   - bpo-21201(102): Improves readability of multiprocessing error
     message.  Thanks to Wojciech Walczak for patch.

   - bpo-27456(103): asyncio: Set TCP_NODELAY by default.

   - bpo-27906(104): Fix socket accept exhaustion during high TCP
     traffic.  Patch by Kevin Conway.

   - bpo-28174(105): Handle when SO_REUSEPORT isn’t properly supported.
     Patch by Seth Michael Larson.

   - bpo-26654(106): Inspect functools.partial in
     asyncio.Handle.__repr__.  Patch by iceboy.

   - bpo-26909(107): Fix slow pipes IO in asyncio.  Patch by INADA
     Naoki.

   - bpo-28176(108): Fix callbacks race in
     asyncio.SelectorLoop.sock_connect.

   - bpo-27759(109): Fix selectors incorrectly retain invalid file
     descriptors.  Patch by Mark Williams.

   - bpo-28368(110): Refuse monitoring processes if the child watcher
     has no loop attached.  Patch by Vincent Michel.

   - bpo-28369(111): Raise RuntimeError when transport’s FD is used with
     add_reader, add_writer, etc.

   - bpo-28370(112): Speedup asyncio.StreamReader.readexactly.  Patch by
     Коренберг Марк.

   - bpo-28371(113): Deprecate passing asyncio.Handles to
     run_in_executor.

   - bpo-28372(114): Fix asyncio to support formatting of non-python
     coroutines.

   - bpo-28399(115): Remove UNIX socket from FS before binding.  Patch
     by Коренберг Марк.

   - bpo-27972(116): Prohibit Tasks to await on themselves.

   - bpo-26923(117): Fix asyncio.Gather to refuse being cancelled once
     all children are done.  Patch by Johannes Ebke.

   - bpo-26796(118): Don’t configure the number of workers for default
     threadpool executor.  Initial patch by Hans Lawrenz.

   - bpo-28600(119): Optimize loop.call_soon().

   - bpo-28613(120): Fix get_event_loop() return the current loop if
     called from coroutines/callbacks.

   - bpo-28639(121): Fix inspect.isawaitable to always return bool Patch
     by Justin Mayfield.

   - bpo-28652(122): Make loop methods reject socket kinds they do not
     support.

   - bpo-28653(123): Fix a refleak in functools.lru_cache.

   - bpo-28703(124): Fix asyncio.iscoroutinefunction to handle Mock
     objects.

   - bpo-24142(125): Reading a corrupt config file left the parser in an
     invalid state.  Original patch by Florian Höch.

   - bpo-28990(126): Fix SSL hanging if connection is closed before
     handshake completed.  (Patch by HoHo-Ho)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15812

   (2) https://bugs.python.org/issue?@action=redirect&bpo=29094

   (3) https://bugs.python.org/issue?@action=redirect&bpo=13051

   (4) https://bugs.python.org/issue?@action=redirect&bpo=29119

   (5) https://bugs.python.org/issue?@action=redirect&bpo=9770

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28427

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28923

   (8) https://bugs.python.org/issue?@action=redirect&bpo=28871

   (9) https://bugs.python.org/issue?@action=redirect&bpo=19542

   (10) https://bugs.python.org/issue?@action=redirect&bpo=20191

   (11) https://bugs.python.org/issue?@action=redirect&bpo=28779

   (12) https://bugs.python.org/issue?@action=redirect&bpo=28847

   (13) https://bugs.python.org/issue?@action=redirect&bpo=25659

   (14) https://bugs.python.org/issue?@action=redirect&bpo=28732

   (15) https://bugs.python.org/issue?@action=redirect&bpo=28485

   (16) https://bugs.python.org/issue?@action=redirect&bpo=28387

   (17) https://bugs.python.org/issue?@action=redirect&bpo=27517

   (18) https://bugs.python.org/issue?@action=redirect&bpo=28549

   (19) https://bugs.python.org/issue?@action=redirect&bpo=28449

   (20) https://bugs.python.org/issue?@action=redirect&bpo=23262

   (21) https://bugs.python.org/issue?@action=redirect&bpo=27939

   (22) https://bugs.python.org/issue?@action=redirect&bpo=28255

   (23) https://bugs.python.org/issue?@action=redirect&bpo=20491

   (24) https://bugs.python.org/issue?@action=redirect&bpo=28353

   (25) https://bugs.python.org/issue?@action=redirect&bpo=25464

   (26) https://bugs.python.org/issue?@action=redirect&bpo=28488

   (27) https://bugs.python.org/issue?@action=redirect&bpo=24452

   (28) https://bugs.python.org/issue?@action=redirect&bpo=20766

   (29) https://bugs.python.org/issue?@action=redirect&bpo=26293

   (30) https://bugs.python.org/issue?@action=redirect&bpo=28321

   (31) https://bugs.python.org/issue?@action=redirect&bpo=28322

   (32) https://bugs.python.org/issue?@action=redirect&bpo=1703178

   (33) https://bugs.python.org/issue?@action=redirect&bpo=28253

   (34) https://bugs.python.org/issue?@action=redirect&bpo=28275

   (35) https://bugs.python.org/issue?@action=redirect&bpo=27897

   (36) https://bugs.python.org/issue?@action=redirect&bpo=18893

   (37) https://bugs.python.org/issue?@action=redirect&bpo=27611

   (38) https://bugs.python.org/issue?@action=redirect&bpo=27348

   (39) https://bugs.python.org/issue?@action=redirect&bpo=25651

   (40) https://bugs.python.org/issue?@action=redirect&bpo=27932

   (41) https://bugs.python.org/issue?@action=redirect&bpo=28075

   (42) https://bugs.python.org/issue?@action=redirect&bpo=25270

   (43) https://bugs.python.org/issue?@action=redirect&bpo=28181

   (44) https://bugs.python.org/issue?@action=redirect&bpo=25895

   (45) https://bugs.python.org/issue?@action=redirect&bpo=27599

   (46) https://bugs.python.org/issue?@action=redirect&bpo=19003

   (47) https://bugs.python.org/issue?@action=redirect&bpo=28019

   (48) https://bugs.python.org/issue?@action=redirect&bpo=25969

   (49) https://bugs.python.org/issue?@action=redirect&bpo=14977

   (50) https://bugs.python.org/issue?@action=redirect&bpo=24594

   (51) https://bugs.python.org/issue?@action=redirect&bpo=17582

   (52) https://bugs.python.org/issue?@action=redirect&bpo=28047

   (53) https://bugs.python.org/issue?@action=redirect&bpo=27445

   (54) https://bugs.python.org/issue?@action=redirect&bpo=22450

   (55) https://bugs.python.org/issue?@action=redirect&bpo=27570

   (56) https://bugs.python.org/issue?@action=redirect&bpo=22233

   (57) https://bugs.python.org/issue?@action=redirect&bpo=27988

   (58) https://bugs.python.org/issue?@action=redirect&bpo=27691

   (59) https://bugs.python.org/issue?@action=redirect&bpo=27850

   (60) https://www.cve.org/CVERecord?id=CVE-2016-2183

   (61) https://bugs.python.org/issue?@action=redirect&bpo=27766

   (62) https://bugs.python.org/issue?@action=redirect&bpo=26470

   (63) https://bugs.python.org/issue?@action=redirect&bpo=12885

   (64) https://bugs.python.org/issue?@action=redirect&bpo=27881

   (65) https://bugs.python.org/issue?@action=redirect&bpo=27861

   (66) https://bugs.python.org/issue?@action=redirect&bpo=19884

   (67) https://bugs.python.org/issue?@action=redirect&bpo=27706

   (68) https://bugs.python.org/issue?@action=redirect&bpo=10513

   (69) https://bugs.python.org/issue?@action=redirect&bpo=27598

   (70) https://bugs.python.org/issue?@action=redirect&bpo=27539

   (71) https://bugs.python.org/issue?@action=redirect&bpo=21718

   (72) https://bugs.python.org/issue?@action=redirect&bpo=2466

   (73) https://bugs.python.org/issue?@action=redirect&bpo=27773

   (74) https://bugs.python.org/issue?@action=redirect&bpo=26750

   (75) https://bugs.python.org/issue?@action=redirect&bpo=27783

   (76) https://bugs.python.org/issue?@action=redirect&bpo=27774

   (77) https://bugs.python.org/issue?@action=redirect&bpo=27760

   (78) https://bugs.python.org/issue?@action=redirect&bpo=27758

   (79) https://bugs.python.org/issue?@action=redirect&bpo=27568

   (80) https://www.cve.org/CVERecord?id=CVE-2016-1000110

   (81) https://bugs.python.org/issue?@action=redirect&bpo=27656

   (82) https://bugs.python.org/issue?@action=redirect&bpo=27130

   (83) https://bugs.python.org/issue?@action=redirect&bpo=27533

   (84) https://bugs.python.org/issue?@action=redirect&bpo=17711

   (85) https://bugs.python.org/issue?@action=redirect&bpo=27522

   (86) https://bugs.python.org/issue?@action=redirect&bpo=26844

   (87) https://bugs.python.org/issue?@action=redirect&bpo=23804

   (88) https://bugs.python.org/issue?@action=redirect&bpo=27466

   (89) https://bugs.python.org/issue?@action=redirect&bpo=26664

   (90) https://bugs.python.org/issue?@action=redirect&bpo=22115

   (91) https://bugs.python.org/issue?@action=redirect&bpo=27079

   (92) https://bugs.python.org/issue?@action=redirect&bpo=26754

   (93) https://bugs.python.org/issue?@action=redirect&bpo=27048

   (94) https://bugs.python.org/issue?@action=redirect&bpo=27330

   (95) https://bugs.python.org/issue?@action=redirect&bpo=27238

   (96) https://bugs.python.org/issue?@action=redirect&bpo=27122

   (97) https://peps.python.org/pep-0479/

   (98) https://bugs.python.org/issue?@action=redirect&bpo=26386

   (99) https://bugs.python.org/issue?@action=redirect&bpo=16182

   (100) https://bugs.python.org/issue?@action=redirect&bpo=27392

   (101) https://bugs.python.org/issue?@action=redirect&bpo=27930

   (102) https://bugs.python.org/issue?@action=redirect&bpo=21201

   (103) https://bugs.python.org/issue?@action=redirect&bpo=27456

   (104) https://bugs.python.org/issue?@action=redirect&bpo=27906

   (105) https://bugs.python.org/issue?@action=redirect&bpo=28174

   (106) https://bugs.python.org/issue?@action=redirect&bpo=26654

   (107) https://bugs.python.org/issue?@action=redirect&bpo=26909

   (108) https://bugs.python.org/issue?@action=redirect&bpo=28176

   (109) https://bugs.python.org/issue?@action=redirect&bpo=27759

   (110) https://bugs.python.org/issue?@action=redirect&bpo=28368

   (111) https://bugs.python.org/issue?@action=redirect&bpo=28369

   (112) https://bugs.python.org/issue?@action=redirect&bpo=28370

   (113) https://bugs.python.org/issue?@action=redirect&bpo=28371

   (114) https://bugs.python.org/issue?@action=redirect&bpo=28372

   (115) https://bugs.python.org/issue?@action=redirect&bpo=28399

   (116) https://bugs.python.org/issue?@action=redirect&bpo=27972

   (117) https://bugs.python.org/issue?@action=redirect&bpo=26923

   (118) https://bugs.python.org/issue?@action=redirect&bpo=26796

   (119) https://bugs.python.org/issue?@action=redirect&bpo=28600

   (120) https://bugs.python.org/issue?@action=redirect&bpo=28613

   (121) https://bugs.python.org/issue?@action=redirect&bpo=28639

   (122) https://bugs.python.org/issue?@action=redirect&bpo=28652

   (123) https://bugs.python.org/issue?@action=redirect&bpo=28653

   (124) https://bugs.python.org/issue?@action=redirect&bpo=28703

   (125) https://bugs.python.org/issue?@action=redirect&bpo=24142

   (126) https://bugs.python.org/issue?@action=redirect&bpo=28990


File: python.info,  Node: IDLE<57>,  Next: C API<76>,  Prev: Library<192>,  Up: Python 3 5 3 release candidate 1

1.24.102.4 IDLE
...............

   - bpo-15308(1): Add “interrupt execution” (^C) to Shell menu.  Patch
     by Roger Serwy, updated by Bayard Randel.

   - bpo-27922(2): Stop IDLE tests from “flashing” gui widgets on the
     screen.

   - Add version to title of IDLE help window.

   - bpo-25564(3): In section on IDLE – console differences, mention
     that using exec means that __builtins__ is defined for each
     statement.

   - bpo-27714(4): text_textview and test_autocomplete now pass when
     re-run in the same process.  This occurs when test_idle fails when
     run with the -w option but without -jn.  Fix warning from
     test_config.

   - bpo-25507(5): IDLE no longer runs buggy code because of its tkinter
     imports.  Users must include the same imports required to run
     directly in Python.

   - bpo-27452(6): add line counter and crc to IDLE configHandler test
     dump.

   - bpo-27365(7): Allow non-ascii chars in IDLE NEWS.txt, for
     contributor names.

   - bpo-27245(8): IDLE: Cleanly delete custom themes and key bindings.
     Previously, when IDLE was started from a console or by import, a
     cascade of warnings was emitted.  Patch by Serhiy Storchaka.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15308

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27922

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25564

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27714

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25507

   (6) https://bugs.python.org/issue?@action=redirect&bpo=27452

   (7) https://bugs.python.org/issue?@action=redirect&bpo=27365

   (8) https://bugs.python.org/issue?@action=redirect&bpo=27245


File: python.info,  Node: C API<76>,  Next: Documentation<78>,  Prev: IDLE<57>,  Up: Python 3 5 3 release candidate 1

1.24.102.5 C API
................

   - bpo-28808(1): PyUnicode_CompareWithASCIIString() now never raises
     exceptions.

   - bpo-26754(2): PyUnicode_FSDecoder() accepted a filename argument
     encoded as an iterable of integers.  Now only strings and
     bytes-like objects are accepted.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28808

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26754


File: python.info,  Node: Documentation<78>,  Next: Tests<79>,  Prev: C API<76>,  Up: Python 3 5 3 release candidate 1

1.24.102.6 Documentation
........................

   - bpo-28513(1): Documented command-line interface of zipfile.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28513


File: python.info,  Node: Tests<79>,  Next: Tools/Demos<55>,  Prev: Documentation<78>,  Up: Python 3 5 3 release candidate 1

1.24.102.7 Tests
................

   - bpo-28950(1): Disallow -j0 to be combined with -T/-l/-M in regrtest
     command line arguments.

   - bpo-28666(2): Now test.support.rmtree is able to remove unwritable
     or unreadable directories.

   - bpo-23839(3): Various caches now are cleared before running every
     test file.

   - bpo-28409(4): regrtest: fix the parser of command line arguments.

   - bpo-27787(5): Call gc.collect() before checking each test for
     «dangling threads», since the dangling threads are weak references.

   - bpo-27369(6): In test_pyexpat, avoid testing an error message
     detail that changed in Expat 2.2.0.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28950

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28666

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23839

   (4) https://bugs.python.org/issue?@action=redirect&bpo=28409

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27787

   (6) https://bugs.python.org/issue?@action=redirect&bpo=27369


File: python.info,  Node: Tools/Demos<55>,  Next: Windows<77>,  Prev: Tests<79>,  Up: Python 3 5 3 release candidate 1

1.24.102.8 Tools/Demos
......................

   - bpo-27952(1): Get Tools/scripts/fixcid.py working with Python 3 and
     the current «re» module, avoid invalid Python backslash escapes,
     and fix a bug parsing escaped C quote signs.

   - bpo-27332(2): Fixed the type of the first argument of module-level
     functions generated by Argument Clinic.  Patch by Petr Viktorin.

   - bpo-27418(3): Fixed Tools/importbench/importbench.py.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27952

   (2) https://bugs.python.org/issue?@action=redirect&bpo=27332

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27418


File: python.info,  Node: Windows<77>,  Next: Build<90>,  Prev: Tools/Demos<55>,  Up: Python 3 5 3 release candidate 1

1.24.102.9 Windows
..................

   - bpo-28251(1): Improvements to help manuals on Windows.

   - bpo-28110(2): launcher.msi has different product codes between
     32-bit and 64-bit

   - bpo-25144(3): Ensures TargetDir is set before continuing with
     custom install.

   - bpo-27469(4): Adds a shell extension to the launcher so that drag
     and drop works correctly.

   - bpo-27309(5): Enabled proper Windows styles in python[w].exe
     manifest.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28251

   (2) https://bugs.python.org/issue?@action=redirect&bpo=28110

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25144

   (4) https://bugs.python.org/issue?@action=redirect&bpo=27469

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27309


File: python.info,  Node: Build<90>,  Prev: Windows<77>,  Up: Python 3 5 3 release candidate 1

1.24.102.10 Build
.................

   - bpo-29080(1): Removes hard dependency on hg.exe from
     PCBuild/build.bat

   - bpo-23903(2): Added missed names to PC/python3.def.

   - bpo-10656(3): Fix out-of-tree building on AIX. Patch by Tristan
     Carel and Michael Haubenwallner.

   - bpo-26359(4): Rename –with-optimiations to –enable-optimizations.

   - bpo-28444(5): Fix missing extensions modules when cross compiling.

   - bpo-28248(6): Update Windows build and OS X installers to use
     OpenSSL 1.0.2j.

   - bpo-28258(7): Fixed build with Estonian locale (python-config and
     distclean targets in Makefile).  Patch by Arfrever Frehtes
     Taifersar Arahesis.

   - bpo-26661(8): setup.py now detects system libffi with multiarch
     wrapper.

   - bpo-28066(9): Fix the logic that searches build directories for
     generated include files when building outside the source tree.

   - bpo-15819(10): Remove redundant include search directory option for
     building outside the source tree.

   - bpo-27566(11): Fix clean target in freeze makefile (patch by Lisa
     Roach)

   - bpo-27705(12): Update message in validate_ucrtbase.py

   - bpo-27983(13): Cause lack of llvm-profdata tool when using clang as
     required for PGO linking to be a configure time error rather than
     make time when –with-optimizations is enabled.  Also improve our
     ability to find the llvm-profdata tool on MacOS and some Linuxes.

   - bpo-26307(14): The profile-opt build now applies PGO to the
     built-in modules.

   - bpo-26359(15): Add the –with-optimizations configure flag.

   - bpo-27713(16): Suppress spurious build warnings when updating
     importlib’s bootstrap files.  Patch by Xiang Zhang

   - bpo-25825(17): Correct the references to Modules/python.exp and
     ld_so_aix, which are required on AIX. This updates references to an
     installation path that was changed in 3.2a4, and undoes changed
     references to the build tree that were made in 3.5.0a1.

   - bpo-27453(18): CPP invocation in configure must use CPPFLAGS. Patch
     by Chi Hsuan Yen.

   - bpo-27641(19): The configure script now inserts comments into the
     makefile to prevent the pgen and _freeze_importlib executables from
     being cross-compiled.

   - bpo-26662(20): Set PYTHON_FOR_GEN in configure as the Python
     program to be used for file generation during the build.

   - bpo-10910(21): Avoid C++ compilation errors on FreeBSD and OS X.
     Also update FreedBSD version checks for the original ctype UTF-8
     workaround.

   - bpo-28676(22): Prevent missing “getentropy” declaration warning on
     macOS. Patch by Gareth Rees.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=29080

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23903

   (3) https://bugs.python.org/issue?@action=redirect&bpo=10656

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26359

   (5) https://bugs.python.org/issue?@action=redirect&bpo=28444

   (6) https://bugs.python.org/issue?@action=redirect&bpo=28248

   (7) https://bugs.python.org/issue?@action=redirect&bpo=28258

   (8) https://bugs.python.org/issue?@action=redirect&bpo=26661

   (9) https://bugs.python.org/issue?@action=redirect&bpo=28066

   (10) https://bugs.python.org/issue?@action=redirect&bpo=15819

   (11) https://bugs.python.org/issue?@action=redirect&bpo=27566

   (12) https://bugs.python.org/issue?@action=redirect&bpo=27705

   (13) https://bugs.python.org/issue?@action=redirect&bpo=27983

   (14) https://bugs.python.org/issue?@action=redirect&bpo=26307

   (15) https://bugs.python.org/issue?@action=redirect&bpo=26359

   (16) https://bugs.python.org/issue?@action=redirect&bpo=27713

   (17) https://bugs.python.org/issue?@action=redirect&bpo=25825

   (18) https://bugs.python.org/issue?@action=redirect&bpo=27453

   (19) https://bugs.python.org/issue?@action=redirect&bpo=27641

   (20) https://bugs.python.org/issue?@action=redirect&bpo=26662

   (21) https://bugs.python.org/issue?@action=redirect&bpo=10910

   (22) https://bugs.python.org/issue?@action=redirect&bpo=28676


File: python.info,  Node: Python 3 5 2 final,  Next: Python 3 5 2 release candidate 1,  Prev: Python 3 5 3 release candidate 1,  Up: Changelog

1.24.103 Python 3.5.2 final
---------------------------

'Release date: 2016-06-26'

* Menu:

* Core and Builtins: Core and Builtins<189>.
* Tests: Tests<80>.
* IDLE: IDLE<58>.


File: python.info,  Node: Core and Builtins<189>,  Next: Tests<80>,  Up: Python 3 5 2 final

1.24.103.1 Core and Builtins
............................

   - bpo-26930(1): Update Windows builds to use OpenSSL 1.0.2h.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26930


File: python.info,  Node: Tests<80>,  Next: IDLE<58>,  Prev: Core and Builtins<189>,  Up: Python 3 5 2 final

1.24.103.2 Tests
................

   - bpo-26867(1): Ubuntu’s openssl OP_NO_SSLv3 is forced on by default;
     fix test.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26867


File: python.info,  Node: IDLE<58>,  Prev: Tests<80>,  Up: Python 3 5 2 final

1.24.103.3 IDLE
...............

   - bpo-27365(1): Allow non-ascii in idlelib/NEWS.txt - minimal part
     for 3.5.2.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27365


File: python.info,  Node: Python 3 5 2 release candidate 1,  Next: Python 3 5 1 final,  Prev: Python 3 5 2 final,  Up: Changelog

1.24.104 Python 3.5.2 release candidate 1
-----------------------------------------

'Release date: 2016-06-12'

* Menu:

* Security: Security<60>.
* Core and Builtins: Core and Builtins<190>.
* Library: Library<193>.
* IDLE: IDLE<59>.
* Documentation: Documentation<79>.
* Tests: Tests<81>.
* Build: Build<91>.
* Windows: Windows<78>.
* Tools/Demos: Tools/Demos<56>.


File: python.info,  Node: Security<60>,  Next: Core and Builtins<190>,  Up: Python 3 5 2 release candidate 1

1.24.104.1 Security
...................

   - bpo-26556(1): Update expat to 2.1.1, fixes CVE 2015-1283(2).

   - Fix TLS stripping vulnerability in smtplib, CVE 2016-0772(3).
     Reported by Team Oststrom.

   - bpo-26839(4): On Linux, *note os.urandom(): 747. now calls
     ‘getrandom()’ with ‘GRND_NONBLOCK’ to fall back on reading
     ‘/dev/urandom’ if the urandom entropy pool is not initialized yet.
     Patch written by Colm Buckley.

   - bpo-26657(5): Fix directory traversal vulnerability with
     http.server on Windows.  This fixes a regression that was
     introduced in 3.3.4rc1 and 3.4.0rc1.  Based on patch by Philipp
     Hagemeister.

   - bpo-26313(6): ssl.py _load_windows_store_certs fails if windows
     cert store is empty.  Patch by Baji.

   - bpo-25939(7): On Windows open the cert store readonly in
     ssl.enum_certificates.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26556

   (2) https://www.cve.org/CVERecord?id=CVE-2015-1283

   (3) https://www.cve.org/CVERecord?id=CVE-2016-0772

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26839

   (5) https://bugs.python.org/issue?@action=redirect&bpo=26657

   (6) https://bugs.python.org/issue?@action=redirect&bpo=26313

   (7) https://bugs.python.org/issue?@action=redirect&bpo=25939


File: python.info,  Node: Core and Builtins<190>,  Next: Library<193>,  Prev: Security<60>,  Up: Python 3 5 2 release candidate 1

1.24.104.2 Core and Builtins
............................

   - bpo-27066(1): Fixed SystemError if a custom opener (for open())
     returns a negative number without setting an exception.

   - bpo-20041(2): Fixed TypeError when frame.f_trace is set to None.
     Patch by Xavier de Gaye.

   - bpo-26168(3): Fixed possible refleaks in failing Py_BuildValue()
     with the «N» format unit.

   - bpo-26991(4): Fix possible refleak when creating a function with
     annotations.

   - bpo-27039(5): Fixed bytearray.remove() for values greater than 127.
     Patch by Joe Jevnik.

   - bpo-23640(6): int.from_bytes() no longer bypasses constructors for
     subclasses.

   - bpo-26811(7): gc.get_objects() no longer contains a broken tuple
     with NULL pointer.

   - bpo-20120(8): Use RawConfigParser for .pypirc parsing, removing
     support for interpolation unintentionally added with move to Python
     3.  Behavior no longer does any interpolation in .pypirc files,
     matching behavior in Python 2.7 and Setuptools 19.0.

   - bpo-26659(9): Make the builtin slice type support cycle collection.

   - bpo-26718(10): super.__init__ no longer leaks memory if called
     multiple times.  NOTE: A direct call of super.__init__ is not
     endorsed!

   - bpo-25339(11): PYTHONIOENCODING now has priority over locale in
     setting the error handler for stdin and stdout.

   - bpo-26494(12): Fixed crash on iterating exhausting iterators.
     Affected classes are generic sequence iterators, iterators of str,
     bytes, bytearray, list, tuple, set, frozenset, dict, OrderedDict,
     corresponding views and os.scandir() iterator.

   - bpo-26581(13): If coding cookie is specified multiple times on a
     line in Python source code file, only the first one is taken to
     account.

   - bpo-26464(14): Fix str.translate() when string is ASCII and first
     replacements removes character, but next replacement uses a
     non-ASCII character or a string longer than 1 character.
     Regression introduced in Python 3.5.0.

   - bpo-22836(15): Ensure exception reports from PyErr_Display() and
     PyErr_WriteUnraisable() are sensible even when formatting them
     produces secondary errors.  This affects the reports produced by
     sys.__excepthook__() and when __del__() raises an exception.

   - bpo-26302(16): Correct behavior to reject comma as a legal
     character for cookie names.

   - bpo-4806(17): Avoid masking the original TypeError exception when
     using star (‘*’) unpacking in function calls.  Based on patch by
     Hagen Fürstenau and Daniel Urban.

   - bpo-27138(18): Fix the doc comment for FileFinder.find_spec().

   - bpo-26154(19): Add a new private _PyThreadState_UncheckedGet()
     function to get the current Python thread state, but don’t issue a
     fatal error if it is NULL. This new function must be used instead
     of accessing directly the _PyThreadState_Current variable.  The
     variable is no more exposed since Python 3.5.1 to hide the exact
     implementation of atomic C types, to avoid compiler issues.

   - bpo-26194(20): Deque.insert() gave odd results for bounded deques
     that had reached their maximum size.  Now an IndexError will be
     raised when attempting to insert into a full deque.

   - bpo-25843(21): When compiling code, don’t merge constants if they
     are equal but have a different types.  For example, ‘f1, f2 =
     lambda: 1, lambda: 1.0’ is now correctly compiled to two different
     functions: ‘f1()’ returns ‘1’ (‘int’) and ‘f2()’ returns ‘1.0’
     (‘int’), even if ‘1’ and ‘1.0’ are equal.

   - bpo-22995(22): [UPDATE] Comment out the one of the pickleability
     tests in _PyObject_GetState() due to regressions observed in
     Cython-based projects.

   - bpo-25961(23): Disallowed null characters in the type name.

   - bpo-25973(24): Fix segfault when an invalid nonlocal statement
     binds a name starting with two underscores.

   - bpo-22995(25): Instances of extension types with a state that
     aren’t subclasses of list or dict and haven’t implemented any
     pickle-related methods (__reduce__, __reduce_ex__, __getnewargs__,
     __getnewargs_ex__, or __getstate__), can no longer be pickled.
     Including memoryview.

   - bpo-20440(26): Massive replacing unsafe attribute setting code with
     special macro Py_SETREF.

   - bpo-25766(27): Special method __bytes__() now works in str
     subclasses.

   - bpo-25421(28): __sizeof__ methods of builtin types now use dynamic
     basic size.  This allows sys.getsize() to work correctly with their
     subclasses with __slots__ defined.

   - bpo-25709(29): Fixed problem with in-place string concatenation and
     utf-8 cache.

   - bpo-27147(30): Mention PEP 420(31) in the importlib docs.

   - bpo-24097(32): Fixed crash in object.__reduce__() if slot name is
     freed inside __getattr__.

   - bpo-24731(33): Fixed crash on converting objects with special
     methods __bytes__, __trunc__, and __float__ returning instances of
     subclasses of bytes, int, and float to subclasses of bytes, int,
     and float correspondingly.

   - bpo-26478(34): Fix semantic bugs when using binary operators with
     dictionary views and tuples.

   - bpo-26171(35): Fix possible integer overflow and heap corruption in
     zipimporter.get_data().

   - bpo-25660(36): Fix TAB key behaviour in REPL with readline.

   - bpo-25887(37): Raise a RuntimeError when a coroutine object is
     awaited more than once.

   - bpo-27243(38): Update the __aiter__ protocol: instead of returning
     an awaitable that resolves to an asynchronous iterator, the
     asynchronous iterator should be returned directly.  Doing the
     former will trigger a PendingDeprecationWarning.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27066

   (2) https://bugs.python.org/issue?@action=redirect&bpo=20041

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26168

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26991

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27039

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23640

   (7) https://bugs.python.org/issue?@action=redirect&bpo=26811

   (8) https://bugs.python.org/issue?@action=redirect&bpo=20120

   (9) https://bugs.python.org/issue?@action=redirect&bpo=26659

   (10) https://bugs.python.org/issue?@action=redirect&bpo=26718

   (11) https://bugs.python.org/issue?@action=redirect&bpo=25339

   (12) https://bugs.python.org/issue?@action=redirect&bpo=26494

   (13) https://bugs.python.org/issue?@action=redirect&bpo=26581

   (14) https://bugs.python.org/issue?@action=redirect&bpo=26464

   (15) https://bugs.python.org/issue?@action=redirect&bpo=22836

   (16) https://bugs.python.org/issue?@action=redirect&bpo=26302

   (17) https://bugs.python.org/issue?@action=redirect&bpo=4806

   (18) https://bugs.python.org/issue?@action=redirect&bpo=27138

   (19) https://bugs.python.org/issue?@action=redirect&bpo=26154

   (20) https://bugs.python.org/issue?@action=redirect&bpo=26194

   (21) https://bugs.python.org/issue?@action=redirect&bpo=25843

   (22) https://bugs.python.org/issue?@action=redirect&bpo=22995

   (23) https://bugs.python.org/issue?@action=redirect&bpo=25961

   (24) https://bugs.python.org/issue?@action=redirect&bpo=25973

   (25) https://bugs.python.org/issue?@action=redirect&bpo=22995

   (26) https://bugs.python.org/issue?@action=redirect&bpo=20440

   (27) https://bugs.python.org/issue?@action=redirect&bpo=25766

   (28) https://bugs.python.org/issue?@action=redirect&bpo=25421

   (29) https://bugs.python.org/issue?@action=redirect&bpo=25709

   (30) https://bugs.python.org/issue?@action=redirect&bpo=27147

   (31) https://peps.python.org/pep-0420/

   (32) https://bugs.python.org/issue?@action=redirect&bpo=24097

   (33) https://bugs.python.org/issue?@action=redirect&bpo=24731

   (34) https://bugs.python.org/issue?@action=redirect&bpo=26478

   (35) https://bugs.python.org/issue?@action=redirect&bpo=26171

   (36) https://bugs.python.org/issue?@action=redirect&bpo=25660

   (37) https://bugs.python.org/issue?@action=redirect&bpo=25887

   (38) https://bugs.python.org/issue?@action=redirect&bpo=27243


File: python.info,  Node: Library<193>,  Next: IDLE<59>,  Prev: Core and Builtins<190>,  Up: Python 3 5 2 release candidate 1

1.24.104.3 Library
..................

   - bpo-21386(1): Implement missing IPv4Address.is_global property.  It
     was documented since 07a5610bae9d.  Initial patch by Roger Luethi.

   - bpo-20900(2): distutils register command now decodes HTTP responses
     correctly.  Initial patch by ingrid.

   - A new version of typing.py provides several new classes and
     features: @overload outside stubs, Reversible, DefaultDict, Text,
     ContextManager, Type[], NewType(), TYPE_CHECKING, and numerous bug
     fixes (note that some of the new features are not yet implemented
     in mypy or other static analyzers).  Also classes for PEP 492(3)
     (Awaitable, AsyncIterable, AsyncIterator) have been added (in fact
     they made it into 3.5.1 but were never mentioned).

   - bpo-25738(4): Stop http.server.BaseHTTPRequestHandler.send_error()
     from sending a message body for 205 Reset Content.  Also, don’t
     send Content header fields in responses that don’t have a body.
     Patch by Susumu Koshiba.

   - bpo-21313(5): Fix the «platform» module to tolerate when
     sys.version contains truncated build information.

   - bpo-27164(6): In the zlib module, allow decompressing raw Deflate
     streams with a predefined zdict.  Based on patch by Xiang Zhang.

   - bpo-24291(7): Fix wsgiref.simple_server.WSGIRequestHandler to
     completely write data to the client.  Previously it could do
     partial writes and truncate data.  Also,
     wsgiref.handler.ServerHandler can now handle stdout doing partial
     writes, but this is deprecated.

   - bpo-26809(8): Add ‘__all__’ to *note string: d8.  Patch by Emanuel
     Barry.

   - bpo-26373(9): subprocess.Popen.communicate now correctly ignores
     BrokenPipeError when the child process dies before .communicate()
     is called in more/all circumstances.

   - bpo-21776(10): distutils.upload now correctly handles HTTPError.
     Initial patch by Claudiu Popa.

   - bpo-27114(11): Fix SSLContext._load_windows_store_certs fails with
     PermissionError

   - bpo-18383(12): Avoid creating duplicate filters when using
     filterwarnings and simplefilter.  Based on patch by Alex Shkop.

   - bpo-27057(13): Fix os.set_inheritable() on Android, ioctl() is
     blocked by SELinux and fails with EACCESS. The function now falls
     back to fcntl().  Patch written by Michał Bednarski.

   - bpo-27014(14): Fix infinite recursion using typing.py.  Thanks to
     Kalle Tuure!

   - bpo-14132(15): Fix urllib.request redirect handling when the target
     only has a query string.  Original fix by Ján Janech.

   - bpo-17214(16): The «urllib.request» module now percent-encodes
     non-ASCII bytes found in redirect target URLs.  Some servers send
     Location header fields with non-ASCII bytes, but «http.client»
     requires the request target to be ASCII-encodable, otherwise a
     UnicodeEncodeError is raised.  Based on patch by Christian Heimes.

   - bpo-26892(17): Honor debuglevel flag in urllib.request.HTTPHandler.
     Patch contributed by Chi Hsuan Yen.

   - bpo-22274(18): In the subprocess module, allow stderr to be
     redirected to stdout even when stdout is not redirected.  Patch by
     Akira Li.

   - bpo-26807(19): mock_open “files” no longer error on readline at end
     of file.  Patch from Yolanda Robla.

   - bpo-25745(20): Fixed leaking a userptr in curses panel destructor.

   - bpo-26977(21): Removed unnecessary, and ignored, call to sum of
     squares helper in statistics.pvariance.

   - bpo-26881(22): The modulefinder module now supports extended opcode
     arguments.

   - bpo-23815(23): Fixed crashes related to directly created instances
     of types in _tkinter and curses.panel modules.

   - bpo-17765(24): weakref.ref() no longer silently ignores keyword
     arguments.  Patch by Georg Brandl.

   - bpo-26873(25): xmlrpc now raises ResponseError on unsupported type
     tags instead of silently return incorrect result.

   - bpo-26711(26): Fixed the comparison of plistlib.Data with other
     types.

   - bpo-24114(27): Fix an uninitialized variable in ‘ctypes.util’.  The
     bug only occurs on SunOS when the ctypes implementation searches
     for the ‘crle’ program.  Patch by Xiang Zhang.  Tested on SunOS by
     Kees Bos.

   - bpo-26864(28): In urllib.request, change the proxy bypass host
     checking against no_proxy to be case-insensitive, and to not match
     unrelated host names that happen to have a bypassed hostname as a
     suffix.  Patch by Xiang Zhang.

   - bpo-26634(29): recursive_repr() now sets __qualname__ of wrapper.
     Patch by Xiang Zhang.

   - bpo-26804(30): urllib.request will prefer lower_case proxy
     environment variables over UPPER_CASE or Mixed_Case ones.  Patch
     contributed by Hans-Peter Jansen.

   - bpo-26837(31): assertSequenceEqual() now correctly outputs
     non-stringified differing items (like bytes in the -b mode).  This
     affects assertListEqual() and assertTupleEqual().

   - bpo-26041(32): Remove «will be removed in Python 3.7» from
     deprecation messages of platform.dist() and
     platform.linux_distribution().  Patch by Kumaripaba Miyurusara
     Athukorala.

   - bpo-26822(33): itemgetter, attrgetter and methodcaller objects no
     longer silently ignore keyword arguments.

   - bpo-26733(34): Disassembling a class now disassembles class and
     static methods.  Patch by Xiang Zhang.

   - bpo-26801(35): Fix error handling in *note
     shutil.get_terminal_size(): 130b, catch *note AttributeError: 5f0.
     instead of *note NameError: 452.  Patch written by Emanuel Barry.

   - bpo-24838(36): tarfile’s ustar and gnu formats now correctly
     calculate name and link field limits for multibyte character
     encodings like utf-8.

   - bpo-26717(37): Stop encoding Latin-1-ized WSGI paths with UTF-8.
     Patch by Anthony Sottile.

   - bpo-26735(38): Fix *note os.urandom(): 747. on Solaris 11.3 and
     newer when reading more than 1,024 bytes: call ‘getrandom()’
     multiple times with a limit of 1024 bytes per call.

   - bpo-16329(39): Add .webm to mimetypes.types_map.  Patch by
     Giampaolo Rodola”.

   - bpo-13952(40): Add .csv to mimetypes.types_map.  Patch by Geoff
     Wilson.

   - bpo-26709(41): Fixed Y2038 problem in loading binary PLists.

   - bpo-23735(42): Handle terminal resizing with Readline 6.3+ by
     installing our own SIGWINCH handler.  Patch by Eric Price.

   - bpo-26586(43): In http.server, respond with «413 Request header
     fields too large» if there are too many header fields to parse,
     rather than killing the connection and raising an unhandled
     exception.  Patch by Xiang Zhang.

   - bpo-22854(44): Change BufferedReader.writable() and
     BufferedWriter.readable() to always return False.

   - bpo-25195(45): Fix a regression in mock.MagicMock.  _Call is a
     subclass of tuple (changeset 3603bae63c13 only works for classes)
     so we need to implement __ne__ ourselves.  Patch by Andrew Plummer.

   - bpo-26644(46): Raise ValueError rather than SystemError when a
     negative length is passed to SSLSocket.recv() or read().

   - bpo-23804(47): Fix SSL recv(0) and read(0) methods to return zero
     bytes instead of up to 1024.

   - bpo-26616(48): Fixed a bug in datetime.astimezone() method.

   - bpo-21925(49): *note warnings.formatwarning(): 1de0. now catches
     exceptions on ‘linecache.getline(...)’ to be able to log *note
     ResourceWarning: 54d. emitted late during the Python shutdown
     process.

   - bpo-24266(50): Ctrl+C during Readline history search now cancels
     the search mode when compiled with Readline 7.

   - bpo-26560(51): Avoid potential ValueError in
     BaseHandler.start_response.  Initial patch by Peter Inglesby.

   - bpo-26569(52): Fix *note pyclbr.readmodule(): a2e. and *note
     pyclbr.readmodule_ex(): a2f. to support importing packages.

   - bpo-26499(53): Account for remaining Content-Length in
     HTTPResponse.readline() and read1().  Based on patch by Silent
     Ghost.  Also document that HTTPResponse now supports these methods.

   - bpo-25320(54): Handle sockets in directories unittest discovery is
     scanning.  Patch from Victor van den Elzen.

   - bpo-16181(55): cookiejar.http2time() now returns None if year is
     higher than datetime.MAXYEAR.

   - bpo-26513(56): Fixes platform module detection of Windows Server

   - bpo-23718(57): Fixed parsing time in week 0 before Jan 1.  Original
     patch by Tamás Bence Gedai.

   - bpo-20589(58): Invoking Path.owner() and Path.group() on Windows
     now raise NotImplementedError instead of ImportError.

   - bpo-26177(59): Fixed the keys() method for Canvas and Scrollbar
     widgets.

   - bpo-15068(60): Got rid of excessive buffering in the fileinput
     module.  The bufsize parameter is no longer used.

   - bpo-2202(61): Fix UnboundLocalError in
     AbstractDigestAuthHandler.get_algorithm_impls.  Initial patch by
     Mathieu Dupuy.

   - bpo-25718(62): Fixed pickling and copying the accumulate() iterator
     with total is None.

   - bpo-26475(63): Fixed debugging output for regular expressions with
     the (?x) flag.

   - bpo-26457(64): Fixed the subnets() methods in IP network classes
     for the case when resulting prefix length is equal to maximal
     prefix length.  Based on patch by Xiang Zhang.

   - bpo-26385(65): Remove the file if the internal open() call in
     NamedTemporaryFile() fails.  Patch by Silent Ghost.

   - bpo-26402(66): Fix XML-RPC client to retry when the server shuts
     down a persistent connection.  This was a regression related to the
     new http.client.RemoteDisconnected exception in 3.5.0a4.

   - bpo-25913(67): Leading ‘<~’ is optional now in base64.a85decode()
     with adobe=True.  Patch by Swati Jaiswal.

   - bpo-26186(68): Remove an invalid type check in
     importlib.util.LazyLoader.

   - bpo-26367(69): importlib.__import__() raises SystemError like
     builtins.__import__() when ‘level’ is specified but without an
     accompanying package specified.

   - bpo-26309(70): In the «socketserver» module, shut down the request
     (closing the connected socket) when verify_request() returns false.
     Patch by Aviv Palivoda.

   - bpo-25995(71): os.walk() no longer uses FDs proportional to the
     tree depth.

   - bpo-26117(72): The os.scandir() iterator now closes file descriptor
     not only when the iteration is finished, but when it was failed
     with error.

   - bpo-25911(73): Restored support of bytes paths in os.walk() on
     Windows.

   - bpo-26045(74): Add UTF-8 suggestion to error message when posting a
     non-Latin-1 string with http.client.

   - bpo-12923(75): Reset FancyURLopener’s redirect counter even if
     there is an exception.  Based on patches by Brian Brazil and Daniel
     Rocco.

   - bpo-25945(76): Fixed a crash when unpickle the functools.partial
     object with wrong state.  Fixed a leak in failed functools.partial
     constructor.  «args» and «keywords» attributes of functools.partial
     have now always types tuple and dict correspondingly.

   - bpo-26202(77): copy.deepcopy() now correctly copies range() objects
     with non-atomic attributes.

   - bpo-23076(78): Path.glob() now raises a ValueError if it’s called
     with an invalid pattern.  Patch by Thomas Nyberg.

   - bpo-19883(79): Fixed possible integer overflows in zipimport.

   - bpo-26227(80): On Windows, getnameinfo(), gethostbyaddr() and
     gethostbyname_ex() functions of the socket module now decode the
     hostname from the ANSI code page rather than UTF-8.

   - bpo-26147(81): xmlrpc now works with strings not encodable with
     used non-UTF-8 encoding.

   - bpo-25935(82): Garbage collector now breaks reference loops with
     OrderedDict.

   - bpo-16620(83): Fixed AttributeError in msilib.Directory.glob().

   - bpo-26013(84): Added compatibility with broken protocol 2 pickles
     created in old Python 3 versions (3.4.3 and lower).

   - bpo-25850(85): Use cross-compilation by default for 64-bit Windows.

   - bpo-17633(86): Improve zipimport’s support for namespace packages.

   - bpo-24705(87): Fix sysconfig._parse_makefile not expanding ${} vars
     appearing before $() vars.

   - bpo-22138(88): Fix mock.patch behavior when patching descriptors.
     Restore original values after patching.  Patch contributed by Sean
     McCully.

   - bpo-25672(89): In the ssl module, enable the
     SSL_MODE_RELEASE_BUFFERS mode option if it is safe to do so.

   - bpo-26012(90): Don’t traverse into symlinks for ‘**’ pattern in
     pathlib.Path.[r]glob().

   - bpo-24120(91): Ignore PermissionError when traversing a tree with
     pathlib.Path.[r]glob().  Patch by Ulrich Petri.

   - bpo-25447(92): fileinput now uses sys.stdin as-is if it does not
     have a buffer attribute (restores backward compatibility).

   - bpo-25447(93): Copying the lru_cache() wrapper object now always
     works, independently from the type of the wrapped object (by
     returning the original object unchanged).

   - bpo-24103(94): Fixed possible use after free in
     ElementTree.XMLPullParser.

   - bpo-25860(95): os.fwalk() no longer skips remaining directories
     when error occurs.  Original patch by Samson Lee.

   - bpo-25914(96): Fixed and simplified OrderedDict.__sizeof__.

   - bpo-25902(97): Fixed various refcount issues in ElementTree
     iteration.

   - bpo-25717(98): Restore the previous behaviour of tolerating most
     fstat() errors when opening files.  This was a regression in 3.5a1,
     and stopped anonymous temporary files from working in special
     cases.

   - bpo-24903(99): Fix regression in number of arguments compileall
     accepts when “-d” is specified.  The check on the number of
     arguments has been dropped completely as it never worked correctly
     anyway.

   - bpo-25764(100): In the subprocess module, preserve any exception
     caused by fork() failure when preexec_fn is used.

   - bpo-6478(101): _strptime’s regexp cache now is reset after changing
     timezone with time.tzset().

   - bpo-14285(102): When executing a package with the «python -m
     package» option, and package initialization fails, a proper
     traceback is now reported.  The «runpy» module now lets exceptions
     from package initialization pass back to the caller, rather than
     raising ImportError.

   - bpo-19771(103): Also in runpy and the «-m» option, omit the
     irrelevant message «… is a package and cannot be directly executed»
     if the package could not even be initialized (e.g.  due to a bad
     ‘*.pyc’ file).

   - bpo-25177(104): Fixed problem with the mean of very small and very
     large numbers.  As a side effect, statistics.mean and
     statistics.variance should be significantly faster.

   - bpo-25718(105): Fixed copying object with state with boolean value
     is false.

   - bpo-10131(106): Fixed deep copying of minidom documents.  Based on
     patch by Marian Ganisin.

   - bpo-25725(107): Fixed a reference leak in pickle.loads() when
     unpickling invalid data including tuple instructions.

   - bpo-25663(108): In the Readline completer, avoid listing duplicate
     global names, and search the global namespace before searching
     builtins.

   - bpo-25688(109): Fixed file leak in ElementTree.iterparse() raising
     an error.

   - bpo-23914(110): Fixed SystemError raised by unpickler on broken
     pickle data.

   - bpo-25691(111): Fixed crash on deleting ElementTree.Element
     attributes.

   - bpo-25624(112): ZipFile now always writes a ZIP_STORED header for
     directory entries.  Patch by Dingyuan Wang.

   - Skip getaddrinfo if host is already resolved.  Patch by A. Jesse
     Jiryu Davis.

   - bpo-26050(113): Add asyncio.StreamReader.readuntil() method.  Patch
     by Марк Коренберг.

   - bpo-25924(114): Avoid unnecessary serialization of getaddrinfo(3)
     calls on OS X versions 10.5 or higher.  Original patch by A. Jesse
     Jiryu Davis.

   - bpo-26406(115): Avoid unnecessary serialization of getaddrinfo(3)
     calls on current versions of OpenBSD and NetBSD. Patch by A. Jesse
     Jiryu Davis.

   - bpo-26848(116): Fix asyncio/subprocess.communicate() to handle
     empty input.  Patch by Jack O’Connor.

   - bpo-27040(117): Add loop.get_exception_handler method

   - bpo-27041(118): asyncio: Add loop.create_future method

   - bpo-27223(119): asyncio: Fix _read_ready and _write_ready to
     respect _conn_lost.  Patch by Łukasz Langa.

   - bpo-22970(120): asyncio: Fix inconsistency cancelling
     Condition.wait.  Patch by David Coles.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21386

   (2) https://bugs.python.org/issue?@action=redirect&bpo=20900

   (3) https://peps.python.org/pep-0492/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=25738

   (5) https://bugs.python.org/issue?@action=redirect&bpo=21313

   (6) https://bugs.python.org/issue?@action=redirect&bpo=27164

   (7) https://bugs.python.org/issue?@action=redirect&bpo=24291

   (8) https://bugs.python.org/issue?@action=redirect&bpo=26809

   (9) https://bugs.python.org/issue?@action=redirect&bpo=26373

   (10) https://bugs.python.org/issue?@action=redirect&bpo=21776

   (11) https://bugs.python.org/issue?@action=redirect&bpo=27114

   (12) https://bugs.python.org/issue?@action=redirect&bpo=18383

   (13) https://bugs.python.org/issue?@action=redirect&bpo=27057

   (14) https://bugs.python.org/issue?@action=redirect&bpo=27014

   (15) https://bugs.python.org/issue?@action=redirect&bpo=14132

   (16) https://bugs.python.org/issue?@action=redirect&bpo=17214

   (17) https://bugs.python.org/issue?@action=redirect&bpo=26892

   (18) https://bugs.python.org/issue?@action=redirect&bpo=22274

   (19) https://bugs.python.org/issue?@action=redirect&bpo=26807

   (20) https://bugs.python.org/issue?@action=redirect&bpo=25745

   (21) https://bugs.python.org/issue?@action=redirect&bpo=26977

   (22) https://bugs.python.org/issue?@action=redirect&bpo=26881

   (23) https://bugs.python.org/issue?@action=redirect&bpo=23815

   (24) https://bugs.python.org/issue?@action=redirect&bpo=17765

   (25) https://bugs.python.org/issue?@action=redirect&bpo=26873

   (26) https://bugs.python.org/issue?@action=redirect&bpo=26711

   (27) https://bugs.python.org/issue?@action=redirect&bpo=24114

   (28) https://bugs.python.org/issue?@action=redirect&bpo=26864

   (29) https://bugs.python.org/issue?@action=redirect&bpo=26634

   (30) https://bugs.python.org/issue?@action=redirect&bpo=26804

   (31) https://bugs.python.org/issue?@action=redirect&bpo=26837

   (32) https://bugs.python.org/issue?@action=redirect&bpo=26041

   (33) https://bugs.python.org/issue?@action=redirect&bpo=26822

   (34) https://bugs.python.org/issue?@action=redirect&bpo=26733

   (35) https://bugs.python.org/issue?@action=redirect&bpo=26801

   (36) https://bugs.python.org/issue?@action=redirect&bpo=24838

   (37) https://bugs.python.org/issue?@action=redirect&bpo=26717

   (38) https://bugs.python.org/issue?@action=redirect&bpo=26735

   (39) https://bugs.python.org/issue?@action=redirect&bpo=16329

   (40) https://bugs.python.org/issue?@action=redirect&bpo=13952

   (41) https://bugs.python.org/issue?@action=redirect&bpo=26709

   (42) https://bugs.python.org/issue?@action=redirect&bpo=23735

   (43) https://bugs.python.org/issue?@action=redirect&bpo=26586

   (44) https://bugs.python.org/issue?@action=redirect&bpo=22854

   (45) https://bugs.python.org/issue?@action=redirect&bpo=25195

   (46) https://bugs.python.org/issue?@action=redirect&bpo=26644

   (47) https://bugs.python.org/issue?@action=redirect&bpo=23804

   (48) https://bugs.python.org/issue?@action=redirect&bpo=26616

   (49) https://bugs.python.org/issue?@action=redirect&bpo=21925

   (50) https://bugs.python.org/issue?@action=redirect&bpo=24266

   (51) https://bugs.python.org/issue?@action=redirect&bpo=26560

   (52) https://bugs.python.org/issue?@action=redirect&bpo=26569

   (53) https://bugs.python.org/issue?@action=redirect&bpo=26499

   (54) https://bugs.python.org/issue?@action=redirect&bpo=25320

   (55) https://bugs.python.org/issue?@action=redirect&bpo=16181

   (56) https://bugs.python.org/issue?@action=redirect&bpo=26513

   (57) https://bugs.python.org/issue?@action=redirect&bpo=23718

   (58) https://bugs.python.org/issue?@action=redirect&bpo=20589

   (59) https://bugs.python.org/issue?@action=redirect&bpo=26177

   (60) https://bugs.python.org/issue?@action=redirect&bpo=15068

   (61) https://bugs.python.org/issue?@action=redirect&bpo=2202

   (62) https://bugs.python.org/issue?@action=redirect&bpo=25718

   (63) https://bugs.python.org/issue?@action=redirect&bpo=26475

   (64) https://bugs.python.org/issue?@action=redirect&bpo=26457

   (65) https://bugs.python.org/issue?@action=redirect&bpo=26385

   (66) https://bugs.python.org/issue?@action=redirect&bpo=26402

   (67) https://bugs.python.org/issue?@action=redirect&bpo=25913

   (68) https://bugs.python.org/issue?@action=redirect&bpo=26186

   (69) https://bugs.python.org/issue?@action=redirect&bpo=26367

   (70) https://bugs.python.org/issue?@action=redirect&bpo=26309

   (71) https://bugs.python.org/issue?@action=redirect&bpo=25995

   (72) https://bugs.python.org/issue?@action=redirect&bpo=26117

   (73) https://bugs.python.org/issue?@action=redirect&bpo=25911

   (74) https://bugs.python.org/issue?@action=redirect&bpo=26045

   (75) https://bugs.python.org/issue?@action=redirect&bpo=12923

   (76) https://bugs.python.org/issue?@action=redirect&bpo=25945

   (77) https://bugs.python.org/issue?@action=redirect&bpo=26202

   (78) https://bugs.python.org/issue?@action=redirect&bpo=23076

   (79) https://bugs.python.org/issue?@action=redirect&bpo=19883

   (80) https://bugs.python.org/issue?@action=redirect&bpo=26227

   (81) https://bugs.python.org/issue?@action=redirect&bpo=26147

   (82) https://bugs.python.org/issue?@action=redirect&bpo=25935

   (83) https://bugs.python.org/issue?@action=redirect&bpo=16620

   (84) https://bugs.python.org/issue?@action=redirect&bpo=26013

   (85) https://bugs.python.org/issue?@action=redirect&bpo=25850

   (86) https://bugs.python.org/issue?@action=redirect&bpo=17633

   (87) https://bugs.python.org/issue?@action=redirect&bpo=24705

   (88) https://bugs.python.org/issue?@action=redirect&bpo=22138

   (89) https://bugs.python.org/issue?@action=redirect&bpo=25672

   (90) https://bugs.python.org/issue?@action=redirect&bpo=26012

   (91) https://bugs.python.org/issue?@action=redirect&bpo=24120

   (92) https://bugs.python.org/issue?@action=redirect&bpo=25447

   (93) https://bugs.python.org/issue?@action=redirect&bpo=25447

   (94) https://bugs.python.org/issue?@action=redirect&bpo=24103

   (95) https://bugs.python.org/issue?@action=redirect&bpo=25860

   (96) https://bugs.python.org/issue?@action=redirect&bpo=25914

   (97) https://bugs.python.org/issue?@action=redirect&bpo=25902

   (98) https://bugs.python.org/issue?@action=redirect&bpo=25717

   (99) https://bugs.python.org/issue?@action=redirect&bpo=24903

   (100) https://bugs.python.org/issue?@action=redirect&bpo=25764

   (101) https://bugs.python.org/issue?@action=redirect&bpo=6478

   (102) https://bugs.python.org/issue?@action=redirect&bpo=14285

   (103) https://bugs.python.org/issue?@action=redirect&bpo=19771

   (104) https://bugs.python.org/issue?@action=redirect&bpo=25177

   (105) https://bugs.python.org/issue?@action=redirect&bpo=25718

   (106) https://bugs.python.org/issue?@action=redirect&bpo=10131

   (107) https://bugs.python.org/issue?@action=redirect&bpo=25725

   (108) https://bugs.python.org/issue?@action=redirect&bpo=25663

   (109) https://bugs.python.org/issue?@action=redirect&bpo=25688

   (110) https://bugs.python.org/issue?@action=redirect&bpo=23914

   (111) https://bugs.python.org/issue?@action=redirect&bpo=25691

   (112) https://bugs.python.org/issue?@action=redirect&bpo=25624

   (113) https://bugs.python.org/issue?@action=redirect&bpo=26050

   (114) https://bugs.python.org/issue?@action=redirect&bpo=25924

   (115) https://bugs.python.org/issue?@action=redirect&bpo=26406

   (116) https://bugs.python.org/issue?@action=redirect&bpo=26848

   (117) https://bugs.python.org/issue?@action=redirect&bpo=27040

   (118) https://bugs.python.org/issue?@action=redirect&bpo=27041

   (119) https://bugs.python.org/issue?@action=redirect&bpo=27223

   (120) https://bugs.python.org/issue?@action=redirect&bpo=22970


File: python.info,  Node: IDLE<59>,  Next: Documentation<79>,  Prev: Library<193>,  Up: Python 3 5 2 release candidate 1

1.24.104.4 IDLE
...............

   - bpo-5124(1): Paste with text selected now replaces the selection on
     X11.  This matches how paste works on Windows, Mac, most modern
     Linux apps, and ttk widgets.  Original patch by Serhiy Storchaka.

   - bpo-24759(2): Make clear in idlelib.idle_test.__init__ that the
     directory is a private implementation of test.test_idle and tool
     for maintainers.

   - bpo-27196(3): Stop “ThemeChanged” warnings when running IDLE tests.
     These persisted after other warnings were suppressed in #20567.
     Apply Serhiy Storchaka’s update_idletasks solution to four test
     files.  Record this additional advice in idle_test/README.txt

   - bpo-20567(4): Revise idle_test/README.txt with advice about
     avoiding tk warning messages from tests.  Apply advice to several
     IDLE tests.

   - bpo-27117(5): Make colorizer htest and turtledemo work with dark
     themes.  Move code for configuring text widget colors to a new
     function.

   - bpo-26673(6): When tk reports font size as 0, change to size 10.
     Such fonts on Linux prevented the configuration dialog from
     opening.

   - bpo-21939(7): Add test for IDLE’s percolator.  Original patch by
     Saimadhav Heblikar.

   - bpo-21676(8): Add test for IDLE’s replace dialog.  Original patch
     by Saimadhav Heblikar.

   - bpo-18410(9): Add test for IDLE’s search dialog.  Original patch by
     Westley Martínez.

   - bpo-21703(10): Add test for IDLE’s undo delegator.  Original patch
     by Saimadhav Heblikar .

   - bpo-27044(11): Add ConfigDialog.remove_var_callbacks to stop memory
     leaks.

   - bpo-23977(12): Add more asserts to test_delegator.

   - bpo-20640(13): Add tests for idlelib.configHelpSourceEdit.  Patch
     by Saimadhav Heblikar.

   - In the “IDLE-console differences” section of the IDLE doc, clarify
     how running with IDLE affects sys.modules and the standard streams.

   - bpo-25507(14): fix incorrect change in IOBinding that prevented
     printing.  Augment IOBinding htest to include all major IOBinding
     functions.

   - bpo-25905(15): Revert unwanted conversion of “ to ’ RIGHT SINGLE
     QUOTATION MARK in README.txt and open this and NEWS.txt with
     “ascii”.  Re-encode CREDITS.txt to utf-8 and open it with “utf-8”.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5124

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24759

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27196

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20567

   (5) https://bugs.python.org/issue?@action=redirect&bpo=27117

   (6) https://bugs.python.org/issue?@action=redirect&bpo=26673

   (7) https://bugs.python.org/issue?@action=redirect&bpo=21939

   (8) https://bugs.python.org/issue?@action=redirect&bpo=21676

   (9) https://bugs.python.org/issue?@action=redirect&bpo=18410

   (10) https://bugs.python.org/issue?@action=redirect&bpo=21703

   (11) https://bugs.python.org/issue?@action=redirect&bpo=27044

   (12) https://bugs.python.org/issue?@action=redirect&bpo=23977

   (13) https://bugs.python.org/issue?@action=redirect&bpo=20640

   (14) https://bugs.python.org/issue?@action=redirect&bpo=25507

   (15) https://bugs.python.org/issue?@action=redirect&bpo=25905


File: python.info,  Node: Documentation<79>,  Next: Tests<81>,  Prev: IDLE<59>,  Up: Python 3 5 2 release candidate 1

1.24.104.5 Documentation
........................

   - bpo-19489(1): Moved the search box from the sidebar to the header
     and footer of each page.  Patch by Ammar Askar.

   - bpo-24136(2): Document the new PEP 448(3) unpacking syntax of 3.5.

   - bpo-26736(4): Used HTTPS for external links in the documentation if
     possible.

   - bpo-6953(5): Rework the Readline module documentation to group
     related functions together, and add more details such as what
     underlying Readline functions and variables are accessed.

   - bpo-23606(6): Adds note to ctypes documentation regarding
     cdll.msvcrt.

   - bpo-25500(7): Fix documentation to not claim that __import__ is
     searched for in the global scope.

   - bpo-26014(8): Update 3.x packaging documentation: * «See also»
     links to the new docs are now provided in the legacy pages * links
     to setuptools documentation have been updated

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19489

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24136

   (3) https://peps.python.org/pep-0448/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26736

   (5) https://bugs.python.org/issue?@action=redirect&bpo=6953

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23606

   (7) https://bugs.python.org/issue?@action=redirect&bpo=25500

   (8) https://bugs.python.org/issue?@action=redirect&bpo=26014


File: python.info,  Node: Tests<81>,  Next: Build<91>,  Prev: Documentation<79>,  Up: Python 3 5 2 release candidate 1

1.24.104.6 Tests
................

   - bpo-21916(1): Added tests for the turtle module.  Patch by ingrid,
     Gregory Loyse and Jelle Zijlstra.

   - bpo-26523(2): The multiprocessing thread pool
     (multiprocessing.dummy.Pool) was untested.

   - bpo-26015(3): Added new tests for pickling iterators of mutable
     sequences.

   - bpo-26325(4): Added test.support.check_no_resource_warning() to
     check that no ResourceWarning is emitted.

   - bpo-25940(5): Changed test_ssl to use self-signed.pythontest.net.
     This avoids relying on svn.python.org, which recently changed root
     certificate.

   - bpo-25616(6): Tests for OrderedDict are extracted from
     test_collections into separate file test_ordered_dict.

   - bpo-26583(7): Skip test_timestamp_overflow in test_import if
     bytecode files cannot be written.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21916

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26523

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26015

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26325

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25940

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25616

   (7) https://bugs.python.org/issue?@action=redirect&bpo=26583


File: python.info,  Node: Build<91>,  Next: Windows<78>,  Prev: Tests<81>,  Up: Python 3 5 2 release candidate 1

1.24.104.7 Build
................

   - bpo-26884(1): Fix linking extension modules for cross builds.
     Patch by Xavier de Gaye.

   - bpo-22359(2): Disable the rules for running _freeze_importlib and
     pgen when cross-compiling.  The output of these programs is
     normally saved with the source code anyway, and is still
     regenerated when doing a native build.  Patch by Xavier de Gaye.

   - bpo-27229(3): Fix the cross-compiling pgen rule for in-tree builds.
     Patch by Xavier de Gaye.

   - bpo-21668(4): Link audioop, _datetime, _ctypes_test modules to
     libm, except on Mac OS X. Patch written by Xavier de Gaye.

   - bpo-25702(5): A –with-lto configure option has been added that will
     enable link time optimizations at build time during a make
     profile-opt.  Some compilers and toolchains are known to not
     produce stable code when using LTO, be sure to test things
     thoroughly before relying on it.  It can provide a few % speed up
     over profile-opt alone.

   - bpo-26624(6): Adds validation of ucrtbase[d].dll version with
     warning for old versions.

   - bpo-17603(7): Avoid error about nonexistent fileblocks.o file by
     using a lower-level check for st_blocks in struct stat.

   - bpo-26079(8): Fixing the build output folder for tix-8.4.3.6.
     Patch by Bjoern Thiel.

   - bpo-26465(9): Update Windows builds to use OpenSSL 1.0.2g.

   - bpo-24421(10): Compile Modules/_math.c once, before building
     extensions.  Previously it could fail to compile properly if the
     math and cmath builds were concurrent.

   - bpo-25348(11): Added ‘--pgo’ and ‘--pgo-job’ arguments to
     ‘PCbuild\build.bat’ for building with Profile-Guided Optimization.
     The old ‘PCbuild\build_pgo.bat’ script is now deprecated, and
     simply calls ‘PCbuild\build.bat --pgo %*’.

   - bpo-25827(12): Add support for building with ICC to ‘configure’,
     including a new ‘--with-icc’ flag.

   - bpo-25696(13): Fix installation of Python on UNIX with make -j9.

   - bpo-26930(14): Update OS X 10.5+ 32-bit-only installer to build and
     link with OpenSSL 1.0.2h.

   - bpo-26268(15): Update Windows builds to use OpenSSL 1.0.2f.

   - bpo-25136(16): Support Apple Xcode 7’s new textual SDK stub
     libraries.

   - bpo-24324(17): Do not enable unreachable code warnings when using
     gcc as the option does not work correctly in older versions of gcc
     and has been silently removed as of gcc-4.5.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26884

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22359

   (3) https://bugs.python.org/issue?@action=redirect&bpo=27229

   (4) https://bugs.python.org/issue?@action=redirect&bpo=21668

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25702

   (6) https://bugs.python.org/issue?@action=redirect&bpo=26624

   (7) https://bugs.python.org/issue?@action=redirect&bpo=17603

   (8) https://bugs.python.org/issue?@action=redirect&bpo=26079

   (9) https://bugs.python.org/issue?@action=redirect&bpo=26465

   (10) https://bugs.python.org/issue?@action=redirect&bpo=24421

   (11) https://bugs.python.org/issue?@action=redirect&bpo=25348

   (12) https://bugs.python.org/issue?@action=redirect&bpo=25827

   (13) https://bugs.python.org/issue?@action=redirect&bpo=25696

   (14) https://bugs.python.org/issue?@action=redirect&bpo=26930

   (15) https://bugs.python.org/issue?@action=redirect&bpo=26268

   (16) https://bugs.python.org/issue?@action=redirect&bpo=25136

   (17) https://bugs.python.org/issue?@action=redirect&bpo=24324


File: python.info,  Node: Windows<78>,  Next: Tools/Demos<56>,  Prev: Build<91>,  Up: Python 3 5 2 release candidate 1

1.24.104.8 Windows
..................

   - bpo-27053(1): Updates make_zip.py to correctly generate library ZIP
     file.

   - bpo-26268(2): Update the prepare_ssl.py script to handle OpenSSL
     releases that don’t include the contents of the include directory
     (that is, 1.0.2e and later).

   - bpo-26071(3): bdist_wininst created binaries fail to start and find
     32bit Python

   - bpo-26073(4): Update the list of magic numbers in launcher

   - bpo-26065(5): Excludes venv from library when generating embeddable
     distro.

   - bpo-17500(6): Remove unused and outdated icons.  (See also:
     ‘https://github.com/python/pythondotorg/issues/945’)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=27053

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26268

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26071

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26073

   (5) https://bugs.python.org/issue?@action=redirect&bpo=26065

   (6) https://bugs.python.org/issue?@action=redirect&bpo=17500


File: python.info,  Node: Tools/Demos<56>,  Prev: Windows<78>,  Up: Python 3 5 2 release candidate 1

1.24.104.9 Tools/Demos
......................

   - bpo-26799(1): Fix python-gdb.py: don’t get C types once when the
     Python code is loaded, but get C types on demand.  The C types can
     change if python-gdb.py is loaded before the Python executable.
     Patch written by Thomas Ilsche.

   - bpo-26271(2): Fix the Freeze tool to properly use flags passed
     through configure.  Patch by Daniel Shaulov.

   - bpo-26489(3): Add dictionary unpacking support to
     Tools/parser/unparse.py.  Patch by Guo Ci Teo.

   - bpo-26316(4): Fix variable name typo in Argument Clinic.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=26799

   (2) https://bugs.python.org/issue?@action=redirect&bpo=26271

   (3) https://bugs.python.org/issue?@action=redirect&bpo=26489

   (4) https://bugs.python.org/issue?@action=redirect&bpo=26316


File: python.info,  Node: Python 3 5 1 final,  Next: Python 3 5 1 release candidate 1,  Prev: Python 3 5 2 release candidate 1,  Up: Changelog

1.24.105 Python 3.5.1 final
---------------------------

'Release date: 2015-12-06'

* Menu:

* Core and Builtins: Core and Builtins<191>.
* Windows: Windows<79>.


File: python.info,  Node: Core and Builtins<191>,  Next: Windows<79>,  Up: Python 3 5 1 final

1.24.105.1 Core and Builtins
............................

   - bpo-25709(1): Fixed problem with in-place string concatenation and
     utf-8 cache.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25709


File: python.info,  Node: Windows<79>,  Prev: Core and Builtins<191>,  Up: Python 3 5 1 final

1.24.105.2 Windows
..................

   - bpo-25715(1): Python 3.5.1 installer shows wrong upgrade path and
     incorrect logic for launcher detection.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25715


File: python.info,  Node: Python 3 5 1 release candidate 1,  Next: Python 3 5 0 final,  Prev: Python 3 5 1 final,  Up: Changelog

1.24.106 Python 3.5.1 release candidate 1
-----------------------------------------

'Release date: 2015-11-22'

* Menu:

* Core and Builtins: Core and Builtins<192>.
* Library: Library<194>.
* IDLE: IDLE<60>.
* Documentation: Documentation<80>.
* Tests: Tests<82>.
* Build: Build<92>.
* Windows: Windows<80>.
* Tools/Demos: Tools/Demos<57>.


File: python.info,  Node: Core and Builtins<192>,  Next: Library<194>,  Up: Python 3 5 1 release candidate 1

1.24.106.1 Core and Builtins
............................

   - bpo-25630(1): Fix a possible segfault during argument parsing in
     functions that accept filesystem paths.

   - bpo-23564(2): Fixed a partially broken sanity check in the
     _posixsubprocess internals regarding how fds_to_pass were passed to
     the child.  The bug had no actual impact as subprocess.py already
     avoided it.

   - bpo-25388(3): Fixed tokenizer crash when processing undecodable
     source code with a null byte.

   - bpo-25462(4): The hash of the key now is calculated only once in
     most operations in C implementation of OrderedDict.

   - bpo-22995(5): Default implementation of __reduce__ and
     __reduce_ex__ now rejects builtin types with not defined __new__.

   - bpo-25555(6): Fix parser and AST: fill lineno and col_offset of
     «arg» node when compiling AST from Python objects.

   - bpo-24802(7): Avoid buffer overreads when int(), float(),
     compile(), exec() and eval() are passed bytes-like objects.  These
     objects are not necessarily terminated by a null byte, but the
     functions assumed they were.

   - bpo-24726(8): Fixed a crash and leaking NULL in repr() of
     OrderedDict that was mutated by direct calls of dict methods.

   - bpo-25449(9): Iterating OrderedDict with keys with unstable hash
     now raises KeyError in C implementations as well as in Python
     implementation.

   - bpo-25395(10): Fixed crash when highly nested OrderedDict
     structures were garbage collected.

   - bpo-25274(11): sys.setrecursionlimit() now raises a RecursionError
     if the new recursion limit is too low depending at the current
     recursion depth.  Modify also the «lower-water mark» formula to
     make it monotonic.  This mark is used to decide when the overflowed
     flag of the thread state is reset.

   - bpo-24402(12): Fix input() to prompt to the redirected stdout when
     sys.stdout.fileno() fails.

   - bpo-24806(13): Prevent builtin types that are not allowed to be
     subclassed from being subclassed through multiple inheritance.

   - bpo-24848(14): Fixed a number of bugs in UTF-7 decoding of
     misformed data.

   - bpo-25280(15): Import trace messages emitted in verbose (-v) mode
     are no longer formatted twice.

   - bpo-25003(16): On Solaris 11.3 or newer, os.urandom() now uses the
     getrandom() function instead of the getentropy() function.  The
     getentropy() function is blocking to generate very good quality
     entropy, os.urandom() doesn’t need such high-quality entropy.

   - bpo-25182(17): The stdprinter (used as sys.stderr before the io
     module is imported at startup) now uses the backslashreplace error
     handler.

   - bpo-25131(18): Make the line number and column offset of set/dict
     literals and comprehensions correspond to the opening brace.

   - bpo-25150(19): Hide the private ‘_Py_atomic_XXX’ symbols from the
     public Python.h header to fix a compilation error with OpenMP.
     PyThreadState_GET() becomes an alias to PyThreadState_Get() to
     avoid ABI incompatibilities.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25630

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23564

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25388

   (4) https://bugs.python.org/issue?@action=redirect&bpo=25462

   (5) https://bugs.python.org/issue?@action=redirect&bpo=22995

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25555

   (7) https://bugs.python.org/issue?@action=redirect&bpo=24802

   (8) https://bugs.python.org/issue?@action=redirect&bpo=24726

   (9) https://bugs.python.org/issue?@action=redirect&bpo=25449

   (10) https://bugs.python.org/issue?@action=redirect&bpo=25395

   (11) https://bugs.python.org/issue?@action=redirect&bpo=25274

   (12) https://bugs.python.org/issue?@action=redirect&bpo=24402

   (13) https://bugs.python.org/issue?@action=redirect&bpo=24806

   (14) https://bugs.python.org/issue?@action=redirect&bpo=24848

   (15) https://bugs.python.org/issue?@action=redirect&bpo=25280

   (16) https://bugs.python.org/issue?@action=redirect&bpo=25003

   (17) https://bugs.python.org/issue?@action=redirect&bpo=25182

   (18) https://bugs.python.org/issue?@action=redirect&bpo=25131

   (19) https://bugs.python.org/issue?@action=redirect&bpo=25150


File: python.info,  Node: Library<194>,  Next: IDLE<60>,  Prev: Core and Builtins<192>,  Up: Python 3 5 1 release candidate 1

1.24.106.2 Library
..................

   - bpo-25626(1): Change three zlib functions to accept sizes that fit
     in Py_ssize_t, but internally cap those sizes to UINT_MAX. This
     resolves a regression in 3.5 where GzipFile.read() failed to read
     chunks larger than 2 or 4 GiB. The change affects the
     zlib.Decompress.decompress() max_length parameter, the
     zlib.decompress() bufsize parameter, and the
     zlib.Decompress.flush() length parameter.

   - bpo-25583(2): Avoid incorrect errors raised by
     os.makedirs(exist_ok=True) when the OS gives priority to errors
     such as EACCES over EEXIST.

   - bpo-25593(3): Change semantics of EventLoop.stop() in asyncio.

   - bpo-6973(4): When we know a subprocess.Popen process has died, do
     not allow the send_signal(), terminate(), or kill() methods to do
     anything as they could potentially signal a different process.

   - bpo-25590(5): In the Readline completer, only call getattr() once
     per attribute.

   - bpo-25498(6): Fix a crash when garbage-collecting ctypes objects
     created by wrapping a memoryview.  This was a regression made in
     3.5a1.  Based on patch by Eryksun.

   - bpo-25584(7): Added «escape» to the __all__ list in the glob
     module.

   - bpo-25584(8): Fixed recursive glob() with patterns starting with
     ‘**’.

   - bpo-25446(9): Fix regression in smtplib’s AUTH LOGIN support.

   - bpo-18010(10): Fix the pydoc web server’s module search function to
     handle exceptions from importing packages.

   - bpo-25554(11): Got rid of circular references in regular expression
     parsing.

   - bpo-25510(12): fileinput.FileInput.readline() now returns b””
     instead of “” at the end if the FileInput was opened with binary
     mode.  Patch by Ryosuke Ito.

   - bpo-25503(13): Fixed inspect.getdoc() for inherited docstrings of
     properties.  Original patch by John Mark Vandenberg.

   - bpo-25515(14): Always use os.urandom as a source of randomness in
     uuid.uuid4.

   - bpo-21827(15): Fixed textwrap.dedent() for the case when largest
     common whitespace is a substring of smallest leading whitespace.
     Based on patch by Robert Li.

   - bpo-25447(16): The lru_cache() wrapper objects now can be copied
     and pickled (by returning the original object unchanged).

   - bpo-25390(17): typing: Don’t crash on Union[str, Pattern].

   - bpo-25441(18): asyncio: Raise error from drain() when socket is
     closed.

   - bpo-25410(19): Cleaned up and fixed minor bugs in C implementation
     of OrderedDict.

   - bpo-25411(20): Improved Unicode support in SMTPHandler through
     better use of the email package.  Thanks to user simon04 for the
     patch.

   - bpo-25407(21): Remove mentions of the formatter module being
     removed in Python 3.6.

   - bpo-25406(22): Fixed a bug in C implementation of
     OrderedDict.move_to_end() that caused segmentation fault or hang in
     iterating after moving several items to the start of ordered dict.

   - bpo-25364(23): zipfile now works in threads disabled builds.

   - bpo-25328(24): smtpd’s SMTPChannel now correctly raises a
     ValueError if both decode_data and enable_SMTPUTF8 are set to true.

   - bpo-25316(25): distutils raises OSError instead of
     DistutilsPlatformError when MSVC is not installed.

   - bpo-25380(26): Fixed protocol for the STACK_GLOBAL opcode in
     pickletools.opcodes.

   - bpo-23972(27): Updates asyncio datagram create method allowing
     reuseport and reuseaddr socket options to be set prior to binding
     the socket.  Mirroring the existing asyncio create_server method
     the reuseaddr option for datagram sockets defaults to True if the
     O/S is “posix” (except if the platform is Cygwin).  Patch by Chris
     Laws.

   - bpo-25304(28): Add asyncio.run_coroutine_threadsafe().  This lets
     you submit a coroutine to a loop from another thread, returning a
     concurrent.futures.Future.  By Vincent Michel.

   - bpo-25232(29): Fix CGIRequestHandler to split the query from the
     URL at the first question mark (?)  rather than the last.  Patch
     from Xiang Zhang.

   - bpo-24657(30): Prevent CGIRequestHandler from collapsing slashes in
     the query part of the URL as if it were a path.  Patch from Xiang
     Zhang.

   - bpo-24483(31): C implementation of functools.lru_cache() now
     calculates key’s hash only once.

   - bpo-22958(32): Constructor and update method of
     weakref.WeakValueDictionary now accept the self and the dict
     keyword arguments.

   - bpo-22609(33): Constructor of collections.UserDict now accepts the
     self keyword argument.

   - bpo-25111(34): Fixed comparison of traceback.FrameSummary.

   - bpo-25262(35): Added support for BINBYTES8 opcode in Python
     implementation of unpickler.  Highest 32 bits of 64-bit size for
     BINUNICODE8 and BINBYTES8 opcodes no longer silently ignored on
     32-bit platforms in C implementation.

   - bpo-25034(36): Fix string.Formatter problem with auto-numbering and
     nested format_specs.  Patch by Anthon van der Neut.

   - bpo-25233(37): Rewrite the guts of asyncio.Queue and
     asyncio.Semaphore to be more understandable and correct.

   - bpo-25203(38): Failed readline.set_completer_delims() no longer
     left the module in inconsistent state.

   - bpo-23600(39): Default implementation of tzinfo.fromutc() was
     returning wrong results in some cases.

   - bpo-23329(40): Allow the ssl module to be built with older versions
     of LibreSSL.

   - Prevent overflow in _Unpickler_Read.

   - bpo-25047(41): The XML encoding declaration written by Element Tree
     now respects the letter case given by the user.  This restores the
     ability to write encoding names in uppercase like «UTF-8», which
     worked in Python 2.

   - bpo-25135(42): Make deque_clear() safer by emptying the deque
     before clearing.  This helps avoid possible reentrancy issues.

   - bpo-19143(43): platform module now reads Windows version from
     kernel32.dll to avoid compatibility shims.

   - bpo-25092(44): Fix datetime.strftime() failure when errno was
     already set to EINVAL.

   - bpo-23517(45): Fix rounding in fromtimestamp() and
     utcfromtimestamp() methods of datetime.datetime: microseconds are
     now rounded to nearest with ties going to nearest even integer
     (ROUND_HALF_EVEN), instead of being rounding towards minus infinity
     (ROUND_FLOOR). It’s important that these methods use the same
     rounding mode than datetime.timedelta to keep the property:
     (datetime(1970,1,1) + timedelta(seconds=t)) ==
     datetime.utcfromtimestamp(t).  It also the rounding mode used by
     round(float) for example.

   - bpo-25155(46): Fix datetime.datetime.now() and
     datetime.datetime.utcnow() on Windows to support date after year
     2038.  It was a regression introduced in Python 3.5.0.

   - bpo-25108(47): Omitted internal frames in traceback functions
     print_stack(), format_stack(), and extract_stack() called without
     arguments.

   - bpo-25118(48): Fix a regression of Python 3.5.0 in os.waitpid() on
     Windows.

   - bpo-24684(49): socket.socket.getaddrinfo() now calls
     PyUnicode_AsEncodedString() instead of calling the encode() method
     of the host, to handle correctly custom string with an encode()
     method which doesn’t return a byte string.  The encoder of the IDNA
     codec is now called directly instead of calling the encode() method
     of the string.

   - bpo-25060(50): Correctly compute stack usage of the BUILD_MAP
     opcode.

   - bpo-24857(51): Comparing call_args to a long sequence now correctly
     returns a boolean result instead of raising an exception.  Patch by
     A Kaptur.

   - bpo-23144(52): Make sure that HTMLParser.feed() returns all the
     data, even when convert_charrefs is True.

   - bpo-24982(53): shutil.make_archive() with the «zip» format now adds
     entries for directories (including empty directories) in ZIP file.

   - bpo-25019(54): Fixed a crash caused by setting non-string key of
     expat parser.  Based on patch by John Leitch.

   - bpo-16180(55): Exit pdb if file has syntax error, instead of
     trapping user in an infinite loop.  Patch by Xavier de Gaye.

   - bpo-24891(56): Fix a race condition at Python startup if the file
     descriptor of stdin (0), stdout (1) or stderr (2) is closed while
     Python is creating sys.stdin, sys.stdout and sys.stderr objects.
     These attributes are now set to None if the creation of the object
     failed, instead of raising an OSError exception.  Initial patch
     written by Marco Paolini.

   - bpo-24992(57): Fix error handling and a race condition (related to
     garbage collection) in collections.OrderedDict constructor.

   - bpo-24881(58): Fixed setting binary mode in Python implementation
     of FileIO on Windows and Cygwin.  Patch from Akira Li.

   - bpo-25578(59): Fix (another) memory leak in SSLSocket.getpeercer().

   - bpo-25530(60): Disable the vulnerable SSLv3 protocol by default
     when creating ssl.SSLContext.

   - bpo-25569(61): Fix memory leak in SSLSocket.getpeercert().

   - bpo-25471(62): Sockets returned from accept() shouldn’t appear to
     be nonblocking.

   - bpo-25319(63): When threading.Event is reinitialized, the
     underlying condition should use a regular lock rather than a
     recursive lock.

   - bpo-21112(64): Fix regression in unittest.expectedFailure on
     subclasses.  Patch from Berker Peksag.

   - bpo-24764(65): cgi.FieldStorage.read_multi() now ignores the
     Content-Length header in part headers.  Patch written by Peter
     Landry and reviewed by Pierre Quentel.

   - bpo-24913(66): Fix overrun error in deque.index().  Found by John
     Leitch and Bryce Darling.

   - bpo-24774(67): Fix docstring in http.server.test.  Patch from
     Chiu-Hsiang Hsu.

   - bpo-21159(68): Improve message in
     configparser.InterpolationMissingOptionError.  Patch from Łukasz
     Langa.

   - bpo-20362(69): Honour TestCase.longMessage correctly in
     assertRegex.  Patch from Ilia Kurenkov.

   - bpo-23572(70): Fixed functools.singledispatch on classes with false
     metaclasses.  Patch by Ethan Furman.

   - asyncio: ensure_future() now accepts awaitable objects.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25626

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25583

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25593

   (4) https://bugs.python.org/issue?@action=redirect&bpo=6973

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25590

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25498

   (7) https://bugs.python.org/issue?@action=redirect&bpo=25584

   (8) https://bugs.python.org/issue?@action=redirect&bpo=25584

   (9) https://bugs.python.org/issue?@action=redirect&bpo=25446

   (10) https://bugs.python.org/issue?@action=redirect&bpo=18010

   (11) https://bugs.python.org/issue?@action=redirect&bpo=25554

   (12) https://bugs.python.org/issue?@action=redirect&bpo=25510

   (13) https://bugs.python.org/issue?@action=redirect&bpo=25503

   (14) https://bugs.python.org/issue?@action=redirect&bpo=25515

   (15) https://bugs.python.org/issue?@action=redirect&bpo=21827

   (16) https://bugs.python.org/issue?@action=redirect&bpo=25447

   (17) https://bugs.python.org/issue?@action=redirect&bpo=25390

   (18) https://bugs.python.org/issue?@action=redirect&bpo=25441

   (19) https://bugs.python.org/issue?@action=redirect&bpo=25410

   (20) https://bugs.python.org/issue?@action=redirect&bpo=25411

   (21) https://bugs.python.org/issue?@action=redirect&bpo=25407

   (22) https://bugs.python.org/issue?@action=redirect&bpo=25406

   (23) https://bugs.python.org/issue?@action=redirect&bpo=25364

   (24) https://bugs.python.org/issue?@action=redirect&bpo=25328

   (25) https://bugs.python.org/issue?@action=redirect&bpo=25316

   (26) https://bugs.python.org/issue?@action=redirect&bpo=25380

   (27) https://bugs.python.org/issue?@action=redirect&bpo=23972

   (28) https://bugs.python.org/issue?@action=redirect&bpo=25304

   (29) https://bugs.python.org/issue?@action=redirect&bpo=25232

   (30) https://bugs.python.org/issue?@action=redirect&bpo=24657

   (31) https://bugs.python.org/issue?@action=redirect&bpo=24483

   (32) https://bugs.python.org/issue?@action=redirect&bpo=22958

   (33) https://bugs.python.org/issue?@action=redirect&bpo=22609

   (34) https://bugs.python.org/issue?@action=redirect&bpo=25111

   (35) https://bugs.python.org/issue?@action=redirect&bpo=25262

   (36) https://bugs.python.org/issue?@action=redirect&bpo=25034

   (37) https://bugs.python.org/issue?@action=redirect&bpo=25233

   (38) https://bugs.python.org/issue?@action=redirect&bpo=25203

   (39) https://bugs.python.org/issue?@action=redirect&bpo=23600

   (40) https://bugs.python.org/issue?@action=redirect&bpo=23329

   (41) https://bugs.python.org/issue?@action=redirect&bpo=25047

   (42) https://bugs.python.org/issue?@action=redirect&bpo=25135

   (43) https://bugs.python.org/issue?@action=redirect&bpo=19143

   (44) https://bugs.python.org/issue?@action=redirect&bpo=25092

   (45) https://bugs.python.org/issue?@action=redirect&bpo=23517

   (46) https://bugs.python.org/issue?@action=redirect&bpo=25155

   (47) https://bugs.python.org/issue?@action=redirect&bpo=25108

   (48) https://bugs.python.org/issue?@action=redirect&bpo=25118

   (49) https://bugs.python.org/issue?@action=redirect&bpo=24684

   (50) https://bugs.python.org/issue?@action=redirect&bpo=25060

   (51) https://bugs.python.org/issue?@action=redirect&bpo=24857

   (52) https://bugs.python.org/issue?@action=redirect&bpo=23144

   (53) https://bugs.python.org/issue?@action=redirect&bpo=24982

   (54) https://bugs.python.org/issue?@action=redirect&bpo=25019

   (55) https://bugs.python.org/issue?@action=redirect&bpo=16180

   (56) https://bugs.python.org/issue?@action=redirect&bpo=24891

   (57) https://bugs.python.org/issue?@action=redirect&bpo=24992

   (58) https://bugs.python.org/issue?@action=redirect&bpo=24881

   (59) https://bugs.python.org/issue?@action=redirect&bpo=25578

   (60) https://bugs.python.org/issue?@action=redirect&bpo=25530

   (61) https://bugs.python.org/issue?@action=redirect&bpo=25569

   (62) https://bugs.python.org/issue?@action=redirect&bpo=25471

   (63) https://bugs.python.org/issue?@action=redirect&bpo=25319

   (64) https://bugs.python.org/issue?@action=redirect&bpo=21112

   (65) https://bugs.python.org/issue?@action=redirect&bpo=24764

   (66) https://bugs.python.org/issue?@action=redirect&bpo=24913

   (67) https://bugs.python.org/issue?@action=redirect&bpo=24774

   (68) https://bugs.python.org/issue?@action=redirect&bpo=21159

   (69) https://bugs.python.org/issue?@action=redirect&bpo=20362

   (70) https://bugs.python.org/issue?@action=redirect&bpo=23572


File: python.info,  Node: IDLE<60>,  Next: Documentation<80>,  Prev: Library<194>,  Up: Python 3 5 1 release candidate 1

1.24.106.3 IDLE
...............

   - bpo-15348(1): Stop the debugger engine (normally in a user process)
     before closing the debugger window (running in the IDLE process).
     This prevents the RuntimeErrors that were being caught and ignored.

   - bpo-24455(2): Prevent IDLE from hanging when a) closing the shell
     while the debugger is active (15347); b) closing the debugger with
     the [X] button (15348); and c) activating the debugger when already
     active (24455).  The patch by Mark Roseman does this by making two
     changes.  1.  Suspend and resume the gui.interaction method with
     the tcl vwait mechanism intended for this purpose (instead of
     root.mainloop & .quit).  2.  In gui.run, allow any existing
     interaction to terminate first.

   - Change “The program” to “Your program” in an IDLE “kill program?”
     message to make it clearer that the program referred to is the
     currently running user program, not IDLE itself.

   - bpo-24750(3): Improve the appearance of the IDLE editor window
     status bar.  Patch by Mark Roseman.

   - bpo-25313(4): Change the handling of new built-in text color themes
     to better address the compatibility problem introduced by the
     addition of IDLE Dark.  Consistently use the revised
     idleConf.CurrentTheme everywhere in idlelib.

   - bpo-24782(5): Extension configuration is now a tab in the IDLE
     Preferences dialog rather than a separate dialog.  The former tabs
     are now a sorted list.  Patch by Mark Roseman.

   - bpo-22726(6): Re-activate the config dialog help button with some
     content about the other buttons and the new IDLE Dark theme.

   - bpo-24820(7): IDLE now has an “IDLE Dark” built-in text color
     theme.  It is more or less IDLE Classic inverted, with a cobalt
     blue background.  Strings, comments, keywords, … are still green,
     red, orange, … .  To use it with IDLEs released before November
     2015, hit the “Save as New Custom Theme” button and enter a new
     name, such as “Custom Dark”.  The custom theme will work with any
     IDLE release, and can be modified.

   - bpo-25224(8): README.txt is now an idlelib index for IDLE
     developers and curious users.  The previous user content is now in
     the IDLE doc chapter.  “IDLE” now means “Integrated Development and
     Learning Environment”.

   - bpo-24820(9): Users can now set breakpoint colors in Settings ->
     Custom Highlighting.  Original patch by Mark Roseman.

   - bpo-24972(10): Inactive selection background now matches active
     selection background, as configured by users, on all systems.
     Found items are now always highlighted on Windows.  Initial patch
     by Mark Roseman.

   - bpo-24570(11): Idle: make calltip and completion boxes appear on
     Macs affected by a tk regression.  Initial patch by Mark Roseman.

   - bpo-24988(12): Idle ScrolledList context menus (used in debugger)
     now work on Mac Aqua.  Patch by Mark Roseman.

   - bpo-24801(13): Make right-click for context menu work on Mac Aqua.
     Patch by Mark Roseman.

   - bpo-25173(14): Associate tkinter messageboxes with a specific
     widget.  For Mac OSX, make them a “sheet”.  Patch by Mark Roseman.

   - bpo-25198(15): Enhance the initial html viewer now used for Idle
     Help.  Properly indent fixed-pitch text (patch by Mark Roseman).
     Give code snippet a very Sphinx-like light blueish-gray background.
     Re-use initial width and height set by users for shell and editor.
     When the Table of Contents (TOC) menu is used, put the section
     header at the top of the screen.

   - bpo-25225(16): Condense and rewrite Idle doc section on text
     colors.

   - bpo-21995(17): Explain some differences between IDLE and console
     Python.

   - bpo-22820(18): Explain need for 'print' when running file from Idle
     editor.

   - bpo-25224(19): Doc: augment Idle feature list and no-subprocess
     section.

   - bpo-25219(20): Update doc for Idle command line options.  Some were
     missing and notes were not correct.

   - bpo-24861(21): Most of idlelib is private and subject to change.
     Use idleib.idle.* to start Idle.  See idlelib.__init__.__doc__.

   - bpo-25199(22): Idle: add synchronization comments for future
     maintainers.

   - bpo-16893(23): Replace help.txt with help.html for Idle doc
     display.  The new idlelib/help.html is rstripped
     Doc/build/html/library/idle.html.  It looks better than help.txt
     and will better document Idle as released.  The tkinter html viewer
     that works for this file was written by Mark Roseman.  The now
     unused EditorWindow.HelpDialog class and helt.txt file are
     deprecated.

   - bpo-24199(24): Deprecate unused idlelib.idlever with possible
     removal in 3.6.

   - bpo-24790(25): Remove extraneous code (which also create 2 & 3
     conflicts).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15348

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24455

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24750

   (4) https://bugs.python.org/issue?@action=redirect&bpo=25313

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24782

   (6) https://bugs.python.org/issue?@action=redirect&bpo=22726

   (7) https://bugs.python.org/issue?@action=redirect&bpo=24820

   (8) https://bugs.python.org/issue?@action=redirect&bpo=25224

   (9) https://bugs.python.org/issue?@action=redirect&bpo=24820

   (10) https://bugs.python.org/issue?@action=redirect&bpo=24972

   (11) https://bugs.python.org/issue?@action=redirect&bpo=24570

   (12) https://bugs.python.org/issue?@action=redirect&bpo=24988

   (13) https://bugs.python.org/issue?@action=redirect&bpo=24801

   (14) https://bugs.python.org/issue?@action=redirect&bpo=25173

   (15) https://bugs.python.org/issue?@action=redirect&bpo=25198

   (16) https://bugs.python.org/issue?@action=redirect&bpo=25225

   (17) https://bugs.python.org/issue?@action=redirect&bpo=21995

   (18) https://bugs.python.org/issue?@action=redirect&bpo=22820

   (19) https://bugs.python.org/issue?@action=redirect&bpo=25224

   (20) https://bugs.python.org/issue?@action=redirect&bpo=25219

   (21) https://bugs.python.org/issue?@action=redirect&bpo=24861

   (22) https://bugs.python.org/issue?@action=redirect&bpo=25199

   (23) https://bugs.python.org/issue?@action=redirect&bpo=16893

   (24) https://bugs.python.org/issue?@action=redirect&bpo=24199

   (25) https://bugs.python.org/issue?@action=redirect&bpo=24790


File: python.info,  Node: Documentation<80>,  Next: Tests<82>,  Prev: IDLE<60>,  Up: Python 3 5 1 release candidate 1

1.24.106.4 Documentation
........................

   - bpo-22558(1): Add remaining doc links to source code for
     Python-coded modules.  Patch by Yoni Lavi.

   - bpo-12067(2): Rewrite Comparisons section in the Expressions
     chapter of the language reference.  Some of the details of
     comparing mixed types were incorrect or ambiguous.  NotImplemented
     is only relevant at a lower level than the Expressions chapter.
     Added details of comparing range() objects, and default behaviour
     and consistency suggestions for user-defined classes.  Patch from
     Andy Maier.

   - bpo-24952(3): Clarify the default size argument of stack_size() in
     the «threading» and «_thread» modules.  Patch from Mattip.

   - bpo-23725(4): Overhaul tempfile docs.  Note deprecated status of
     mktemp.  Patch from Zbigniew Jędrzejewski-Szmek.

   - bpo-24808(5): Update the types of some PyTypeObject fields.  Patch
     by Joseph Weston.

   - bpo-22812(6): Fix unittest discovery examples.  Patch from Pam
     McA’Nulty.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22558

   (2) https://bugs.python.org/issue?@action=redirect&bpo=12067

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24952

   (4) https://bugs.python.org/issue?@action=redirect&bpo=23725

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24808

   (6) https://bugs.python.org/issue?@action=redirect&bpo=22812


File: python.info,  Node: Tests<82>,  Next: Build<92>,  Prev: Documentation<80>,  Up: Python 3 5 1 release candidate 1

1.24.106.5 Tests
................

   - bpo-25449(1): Added tests for OrderedDict subclasses.

   - bpo-25099(2): Make test_compileall not fail when an entry on
     sys.path cannot be written to (commonly seen in administrative
     installs on Windows).

   - bpo-23919(3): Prevents assert dialogs appearing in the test suite.

   - ‘PCbuild\rt.bat’ now accepts an unlimited number of arguments to
     pass along to regrtest.py.  Previously there was a limit of 9.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25449

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25099

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23919


File: python.info,  Node: Build<92>,  Next: Windows<80>,  Prev: Tests<82>,  Up: Python 3 5 1 release candidate 1

1.24.106.6 Build
................

   - bpo-24915(1): Add LLVM support for PGO builds and use the test
     suite to generate the profile data.  Initial patch by Alecsandru
     Patrascu of Intel.

   - bpo-24910(2): Windows MSIs now have unique display names.

   - bpo-24986(3): It is now possible to build Python on Windows without
     errors when external libraries are not available.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24915

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24910

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24986


File: python.info,  Node: Windows<80>,  Next: Tools/Demos<57>,  Prev: Build<92>,  Up: Python 3 5 1 release candidate 1

1.24.106.7 Windows
..................

   - bpo-25450(1): Updates shortcuts to start Python in installation
     directory.

   - bpo-25164(2): Changes default all-users install directory to match
     per-user directory.

   - bpo-25143(3): Improves installer error messages for unsupported
     platforms.

   - bpo-25163(4): Display correct directory in installer when using
     non-default settings.

   - bpo-25361(5): Disables use of SSE2 instructions in Windows 32-bit
     build

   - bpo-25089(6): Adds logging to installer for case where launcher is
     not selected on upgrade.

   - bpo-25165(7): Windows uninstallation should not remove launcher if
     other versions remain

   - bpo-25112(8): py.exe launcher is missing icons

   - bpo-25102(9): Windows installer does not precompile for -O or -OO.

   - bpo-25081(10): Makes Back button in installer go back to upgrade
     page when upgrading.

   - bpo-25091(11): Increases font size of the installer.

   - bpo-25126(12): Clarifies that the non-web installer will download
     some components.

   - bpo-25213(13): Restores requestedExecutionLevel to manifest to
     disable UAC virtualization.

   - bpo-25022(14): Removed very outdated PC/example_nt/ directory.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25450

   (2) https://bugs.python.org/issue?@action=redirect&bpo=25164

   (3) https://bugs.python.org/issue?@action=redirect&bpo=25143

   (4) https://bugs.python.org/issue?@action=redirect&bpo=25163

   (5) https://bugs.python.org/issue?@action=redirect&bpo=25361

   (6) https://bugs.python.org/issue?@action=redirect&bpo=25089

   (7) https://bugs.python.org/issue?@action=redirect&bpo=25165

   (8) https://bugs.python.org/issue?@action=redirect&bpo=25112

   (9) https://bugs.python.org/issue?@action=redirect&bpo=25102

   (10) https://bugs.python.org/issue?@action=redirect&bpo=25081

   (11) https://bugs.python.org/issue?@action=redirect&bpo=25091

   (12) https://bugs.python.org/issue?@action=redirect&bpo=25126

   (13) https://bugs.python.org/issue?@action=redirect&bpo=25213

   (14) https://bugs.python.org/issue?@action=redirect&bpo=25022


File: python.info,  Node: Tools/Demos<57>,  Prev: Windows<80>,  Up: Python 3 5 1 release candidate 1

1.24.106.8 Tools/Demos
......................

   - bpo-25440(1): Fix output of python-config –extension-suffix.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25440


File: python.info,  Node: Python 3 5 0 final,  Next: Python 3 5 0 release candidate 4,  Prev: Python 3 5 1 release candidate 1,  Up: Changelog

1.24.107 Python 3.5.0 final
---------------------------

'Release date: 2015-09-13'

* Menu:

* Build: Build<93>.


File: python.info,  Node: Build<93>,  Up: Python 3 5 0 final

1.24.107.1 Build
................

   - bpo-25071(1): Windows installer should not require TargetDir
     parameter when installing quietly.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25071


File: python.info,  Node: Python 3 5 0 release candidate 4,  Next: Python 3 5 0 release candidate 3,  Prev: Python 3 5 0 final,  Up: Changelog

1.24.108 Python 3.5.0 release candidate 4
-----------------------------------------

'Release date: 2015-09-09'

* Menu:

* Library: Library<195>.
* Build: Build<94>.


File: python.info,  Node: Library<195>,  Next: Build<94>,  Up: Python 3 5 0 release candidate 4

1.24.108.1 Library
..................

   - bpo-25029(1): Fixes MemoryError in test_strptime.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25029


File: python.info,  Node: Build<94>,  Prev: Library<195>,  Up: Python 3 5 0 release candidate 4

1.24.108.2 Build
................

   - bpo-25027(1): Reverts partial-static build options and adds
     vcruntime140.dll to Windows installation.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=25027


File: python.info,  Node: Python 3 5 0 release candidate 3,  Next: Python 3 5 0 release candidate 2,  Prev: Python 3 5 0 release candidate 4,  Up: Changelog

1.24.109 Python 3.5.0 release candidate 3
-----------------------------------------

'Release date: 2015-09-07'

* Menu:

* Core and Builtins: Core and Builtins<193>.
* Library: Library<196>.


File: python.info,  Node: Core and Builtins<193>,  Next: Library<196>,  Up: Python 3 5 0 release candidate 3

1.24.109.1 Core and Builtins
............................

   - bpo-24305(1): Prevent import subsystem stack frames from being
     counted by the warnings.warn(stacklevel=) parameter.

   - bpo-24912(2): Prevent __class__ assignment to immutable built-in
     objects.

   - bpo-24975(3): Fix AST compilation for PEP 448(4) syntax.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24305

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24912

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24975

   (4) https://peps.python.org/pep-0448/


File: python.info,  Node: Library<196>,  Prev: Core and Builtins<193>,  Up: Python 3 5 0 release candidate 3

1.24.109.2 Library
..................

   - bpo-24917(1): time_strftime() buffer over-read.

   - bpo-24748(2): To resolve a compatibility problem found with py2exe
     and pywin32, imp.load_dynamic() once again ignores previously
     loaded modules to support Python modules replacing themselves with
     extension modules.  Patch by Petr Viktorin.

   - bpo-24635(3): Fixed a bug in typing.py where isinstance([],
     typing.Iterable) would return True once, then False on subsequent
     calls.

   - bpo-24989(4): Fixed buffer overread in BytesIO.readline() if a
     position is set beyond size.  Based on patch by John Leitch.

   - bpo-24913(5): Fix overrun error in deque.index().  Found by John
     Leitch and Bryce Darling.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24917

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24748

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24635

   (4) https://bugs.python.org/issue?@action=redirect&bpo=24989

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24913


File: python.info,  Node: Python 3 5 0 release candidate 2,  Next: Python 3 5 0 release candidate 1,  Prev: Python 3 5 0 release candidate 3,  Up: Changelog

1.24.110 Python 3.5.0 release candidate 2
-----------------------------------------

'Release date: 2015-08-25'

* Menu:

* Core and Builtins: Core and Builtins<194>.
* Library: Library<197>.


File: python.info,  Node: Core and Builtins<194>,  Next: Library<197>,  Up: Python 3 5 0 release candidate 2

1.24.110.1 Core and Builtins
............................

   - bpo-24769(1): Interpreter now starts properly when dynamic loading
     is disabled.  Patch by Petr Viktorin.

   - bpo-21167(2): NAN operations are now handled correctly when python
     is compiled with ICC even if -fp-model strict is not specified.

   - bpo-24492(3): A «package» lacking a __name__ attribute when trying
     to perform a ‘from .. import ...’ statement will trigger an
     ImportError instead of an AttributeError.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24769

   (2) https://bugs.python.org/issue?@action=redirect&bpo=21167

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24492


File: python.info,  Node: Library<197>,  Prev: Core and Builtins<194>,  Up: Python 3 5 0 release candidate 2

1.24.110.2 Library
..................

   - bpo-24847(1): Removes vcruntime140.dll dependency from Tcl/Tk.

   - bpo-24839(2): platform._syscmd_ver raises DeprecationWarning

   - bpo-24867(3): Fix Task.get_stack() for “async def” coroutines

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24847

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24839

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24867


File: python.info,  Node: Python 3 5 0 release candidate 1,  Next: Python 3 5 0 beta 4,  Prev: Python 3 5 0 release candidate 2,  Up: Changelog

1.24.111 Python 3.5.0 release candidate 1
-----------------------------------------

'Release date: 2015-08-09'

* Menu:

* Core and Builtins: Core and Builtins<195>.
* Library: Library<198>.
* IDLE: IDLE<61>.
* Documentation: Documentation<81>.
* Tests: Tests<83>.


File: python.info,  Node: Core and Builtins<195>,  Next: Library<198>,  Up: Python 3 5 0 release candidate 1

1.24.111.1 Core and Builtins
............................

   - bpo-24667(1): Resize odict in all cases that the underlying dict
     resizes.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24667


File: python.info,  Node: Library<198>,  Next: IDLE<61>,  Prev: Core and Builtins<195>,  Up: Python 3 5 0 release candidate 1

1.24.111.2 Library
..................

   - bpo-24824(1): Signatures of codecs.encode() and codecs.decode() now
     are compatible with pydoc.

   - bpo-24634(2): Importing uuid should not try to load libc on Windows

   - bpo-24798(3): _msvccompiler.py doesn’t properly support manifests

   - bpo-4395(4): Better testing and documentation of binary operators.
     Patch by Martin Panter.

   - bpo-23973(5): Update typing.py from GitHub repo.

   - bpo-23004(6): mock_open() now reads binary data correctly when the
     type of read_data is bytes.  Initial patch by Aaron Hill.

   - bpo-23888(7): Handle fractional time in cookie expiry.  Patch by
     ssh.

   - bpo-23652(8): Make it possible to compile the select module against
     the libc headers from the Linux Standard Base, which do not include
     some EPOLL macros.  Patch by Matt Frank.

   - bpo-22932(9): Fix timezones in email.utils.formatdate.  Patch from
     Dmitry Shachnev.

   - bpo-23779(10): imaplib raises TypeError if authenticator tries to
     abort.  Patch from Craig Holmquist.

   - bpo-23319(11): Fix ctypes.BigEndianStructure, swap correctly bytes.
     Patch written by Matthieu Gautier.

   - bpo-23254(12): Document how to close the TCPServer listening
     socket.  Patch from Martin Panter.

   - bpo-19450(13): Update Windows and OS X installer builds to use
     SQLite 3.8.11.

   - bpo-17527(14): Add PATCH to wsgiref.validator.  Patch from Luca
     Sbardella.

   - bpo-24791(15): Fix grammar regression for call syntax: “g(*a or
     b)”.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24824

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24634

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24798

   (4) https://bugs.python.org/issue?@action=redirect&bpo=4395

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23973

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23004

   (7) https://bugs.python.org/issue?@action=redirect&bpo=23888

   (8) https://bugs.python.org/issue?@action=redirect&bpo=23652

   (9) https://bugs.python.org/issue?@action=redirect&bpo=22932

   (10) https://bugs.python.org/issue?@action=redirect&bpo=23779

   (11) https://bugs.python.org/issue?@action=redirect&bpo=23319

   (12) https://bugs.python.org/issue?@action=redirect&bpo=23254

   (13) https://bugs.python.org/issue?@action=redirect&bpo=19450

   (14) https://bugs.python.org/issue?@action=redirect&bpo=17527

   (15) https://bugs.python.org/issue?@action=redirect&bpo=24791


File: python.info,  Node: IDLE<61>,  Next: Documentation<81>,  Prev: Library<198>,  Up: Python 3 5 0 release candidate 1

1.24.111.3 IDLE
...............

   - bpo-23672(1): Allow Idle to edit and run files with astral chars in
     name.  Patch by Mohd Sanad Zaki Rizvi.

   - bpo-24745(2): Idle editor default font.  Switch from Courier to
     platform-sensitive TkFixedFont.  This should not affect current
     customized font selections.  If there is a problem, edit
     $HOME/.idlerc/config-main.cfg and remove “‘fontXXX’” entries from
     [Editor Window].  Patch by Mark Roseman.

   - bpo-21192(3): Idle editor.  When a file is run, put its name in the
     restart bar.  Do not print false prompts.  Original patch by Adnan
     Umer.

   - bpo-13884(4): Idle menus.  Remove tearoff lines.  Patch by Roger
     Serwy.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23672

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24745

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21192

   (4) https://bugs.python.org/issue?@action=redirect&bpo=13884


File: python.info,  Node: Documentation<81>,  Next: Tests<83>,  Prev: IDLE<61>,  Up: Python 3 5 0 release candidate 1

1.24.111.4 Documentation
........................

   - bpo-24129(1): Clarify the reference documentation for name
     resolution.  This includes removing the assumption that readers
     will be familiar with the name resolution scheme Python used prior
     to the introduction of lexical scoping for function namespaces.
     Patch by Ivan Levkivskyi.

   - bpo-20769(2): Improve reload() docs.  Patch by Dorian Pula.

   - bpo-23589(3): Remove duplicate sentence from the FAQ. Patch by
     Yongzhi Pan.

   - bpo-24729(4): Correct IO tutorial to match implementation regarding
     encoding parameter to open function.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24129

   (2) https://bugs.python.org/issue?@action=redirect&bpo=20769

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23589

   (4) https://bugs.python.org/issue?@action=redirect&bpo=24729


File: python.info,  Node: Tests<83>,  Prev: Documentation<81>,  Up: Python 3 5 0 release candidate 1

1.24.111.5 Tests
................

   - bpo-24751(1): When running regrtest with the ‘-w’ command line
     option, a test run is no longer marked as a failure if all tests
     succeed when re-run.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24751


File: python.info,  Node: Python 3 5 0 beta 4,  Next: Python 3 5 0 beta 3,  Prev: Python 3 5 0 release candidate 1,  Up: Changelog

1.24.112 Python 3.5.0 beta 4
----------------------------

'Release date: 2015-07-26'

* Menu:

* Core and Builtins: Core and Builtins<196>.
* Library: Library<199>.
* Build: Build<95>.


File: python.info,  Node: Core and Builtins<196>,  Next: Library<199>,  Up: Python 3 5 0 beta 4

1.24.112.1 Core and Builtins
............................

   - bpo-23573(1): Restored optimization of bytes.rfind() and
     bytearray.rfind() for single-byte argument on Linux.

   - bpo-24569(2): Make PEP 448(3) dictionary evaluation more
     consistent.

   - bpo-24583(4): Fix crash when set is mutated while being updated.

   - bpo-24407(5): Fix crash when dict is mutated while being updated.

   - bpo-24619(6): New approach for tokenizing async/await.  As a
     consequence, it is now possible to have one-line “async def foo():
     await ..” functions.

   - bpo-24687(7): Plug refleak on SyntaxError in function parameters
     annotations.

   - bpo-15944(8): memoryview: Allow arbitrary formats when casting to
     bytes.  Patch by Martin Panter.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23573

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24569

   (3) https://peps.python.org/pep-0448/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=24583

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24407

   (6) https://bugs.python.org/issue?@action=redirect&bpo=24619

   (7) https://bugs.python.org/issue?@action=redirect&bpo=24687

   (8) https://bugs.python.org/issue?@action=redirect&bpo=15944


File: python.info,  Node: Library<199>,  Next: Build<95>,  Prev: Core and Builtins<196>,  Up: Python 3 5 0 beta 4

1.24.112.2 Library
..................

   - bpo-23441(1): rcompleter now prints a tab character instead of
     displaying possible completions for an empty word.  Initial patch
     by Martin Sekera.

   - bpo-24683(2): Fixed crashes in _json functions called with
     arguments of inappropriate type.

   - bpo-21697(3): shutil.copytree() now correctly handles symbolic
     links that point to directories.  Patch by Eduardo Seabra and
     Thomas Kluyver.

   - bpo-14373(4): Fixed segmentation fault when gc.collect() is called
     during constructing lru_cache (C implementation).

   - bpo-24695(5): Fix a regression in traceback.print_exception().  If
     exc_traceback is None we shouldn’t print a traceback header like
     described in the documentation.

   - bpo-24620(6): Random.setstate() now validates the value of state
     last element.

   - bpo-22485(7): Fixed an issue that caused ‘inspect.getsource’ to
     return incorrect results on nested functions.

   - bpo-22153(8): Improve unittest docs.  Patch from Martin Panter and
     evilzero.

   - bpo-24580(9): Symbolic group references to open group in re
     patterns now are explicitly forbidden as well as numeric group
     references.

   - bpo-24206(10): Fixed __eq__ and __ne__ methods of inspect classes.

   - bpo-24631(11): Fixed regression in the timeit module with multiline
     setup.

   - bpo-18622(12): unittest.mock.mock_open().reset_mock would recurse
     infinitely.  Patch from Nicola Palumbo and Laurent De Buyst.

   - bpo-23661(13): unittest.mock side_effects can now be exceptions
     again.  This was a regression vs Python 3.4.  Patch from Ignacio
     Rossi

   - bpo-24608(14): chunk.Chunk.read() now always returns bytes, not
     str.

   - bpo-18684(15): Fixed reading out of the buffer in the re module.

   - bpo-24259(16): tarfile now raises a ReadError if an archive is
     truncated inside a data segment.

   - bpo-15014(17): SMTP.auth() and SMTP.login() now support RFC 4954’s
     optional initial-response argument to the SMTP AUTH command.

   - bpo-24669(18): Fix inspect.getsource() for “async def” functions.
     Patch by Kai Groner.

   - bpo-24688(19): ast.get_docstring() for “async def” functions.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23441

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24683

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21697

   (4) https://bugs.python.org/issue?@action=redirect&bpo=14373

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24695

   (6) https://bugs.python.org/issue?@action=redirect&bpo=24620

   (7) https://bugs.python.org/issue?@action=redirect&bpo=22485

   (8) https://bugs.python.org/issue?@action=redirect&bpo=22153

   (9) https://bugs.python.org/issue?@action=redirect&bpo=24580

   (10) https://bugs.python.org/issue?@action=redirect&bpo=24206

   (11) https://bugs.python.org/issue?@action=redirect&bpo=24631

   (12) https://bugs.python.org/issue?@action=redirect&bpo=18622

   (13) https://bugs.python.org/issue?@action=redirect&bpo=23661

   (14) https://bugs.python.org/issue?@action=redirect&bpo=24608

   (15) https://bugs.python.org/issue?@action=redirect&bpo=18684

   (16) https://bugs.python.org/issue?@action=redirect&bpo=24259

   (17) https://bugs.python.org/issue?@action=redirect&bpo=15014

   (18) https://bugs.python.org/issue?@action=redirect&bpo=24669

   (19) https://bugs.python.org/issue?@action=redirect&bpo=24688


File: python.info,  Node: Build<95>,  Prev: Library<199>,  Up: Python 3 5 0 beta 4

1.24.112.3 Build
................

   - bpo-24603(1): Update Windows builds and OS X 10.5 installer to use
     OpenSSL 1.0.2d.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24603


File: python.info,  Node: Python 3 5 0 beta 3,  Next: Python 3 5 0 beta 2,  Prev: Python 3 5 0 beta 4,  Up: Changelog

1.24.113 Python 3.5.0 beta 3
----------------------------

'Release date: 2015-07-05'

* Menu:

* Core and Builtins: Core and Builtins<197>.
* Library: Library<200>.
* Tests: Tests<84>.
* Documentation: Documentation<82>.
* Build: Build<96>.


File: python.info,  Node: Core and Builtins<197>,  Next: Library<200>,  Up: Python 3 5 0 beta 3

1.24.113.1 Core and Builtins
............................

   - bpo-24467(1): Fixed possible buffer over-read in bytearray.  The
     bytearray object now always allocates place for trailing null byte
     and it’s buffer now is always null-terminated.

   - Upgrade to Unicode 8.0.0.

   - bpo-24345(2): Add Py_tp_finalize slot for the stable ABI.

   - bpo-24400(3): Introduce a distinct type for PEP 492(4) coroutines;
     add types.CoroutineType, inspect.getcoroutinestate,
     inspect.getcoroutinelocals; coroutines no longer use CO_GENERATOR
     flag; sys.set_coroutine_wrapper works only for “async def”
     coroutines; inspect.iscoroutine no longer uses
     collections.abc.Coroutine, it’s intended to test for pure “async
     def” coroutines only; add new opcode: GET_YIELD_FROM_ITER; fix
     generators wrapper used in types.coroutine to be instance of
     collections.abc.Generator; collections.abc.Awaitable and
     collections.abc.Coroutine can no longer be used to detect
     generator-based coroutines–use inspect.isawaitable instead.

   - bpo-24450(5): Add gi_yieldfrom to generators and cr_await to
     coroutines.  Contributed by Benno Leslie and Yury Selivanov.

   - bpo-19235(6): Add new RecursionError exception.  Patch by Georg
     Brandl.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24467

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24345

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24400

   (4) https://peps.python.org/pep-0492/

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24450

   (6) https://bugs.python.org/issue?@action=redirect&bpo=19235


File: python.info,  Node: Library<200>,  Next: Tests<84>,  Prev: Core and Builtins<197>,  Up: Python 3 5 0 beta 3

1.24.113.2 Library
..................

   - bpo-21750(1): mock_open.read_data can now be read from each
     instance, as it could in Python 3.3.

   - bpo-24552(2): Fix use after free in an error case of the _pickle
     module.

   - bpo-24514(3): tarfile now tolerates number fields consisting of
     only whitespace.

   - bpo-19176(4): Fixed doctype() related bugs in C implementation of
     ElementTree.  A deprecation warning no longer issued by XMLParser
     subclass with default doctype() method.  Direct call of doctype()
     now issues a warning.  Parser’s doctype() now is not called if
     target’s doctype() is called.  Based on patch by Martin Panter.

   - bpo-20387(5): Restore semantic round-trip correctness in
     tokenize/untokenize for tab-indented blocks.

   - bpo-24456(6): Fixed possible buffer over-read in adpcm2lin() and
     lin2adpcm() functions of the audioop module.

   - bpo-24336(7): The contextmanager decorator now works with functions
     with keyword arguments called «func» and «self».  Patch by Martin
     Panter.

   - bpo-24522(8): Fix possible integer overflow in json accelerator
     module.

   - bpo-24489(9): ensure a previously set C errno doesn’t disturb
     cmath.polar().

   - bpo-24408(10): Fixed AttributeError in measure() and metrics()
     methods of tkinter.Font.

   - bpo-14373(11): C implementation of functools.lru_cache() now can be
     used with methods.

   - bpo-24347(12): Set KeyError if PyDict_GetItemWithError returns
     NULL.

   - bpo-24348(13): Drop superfluous incref/decref.

   - bpo-24359(14): Check for changed OrderedDict size during iteration.

   - bpo-24368(15): Support keyword arguments in OrderedDict methods.

   - bpo-24362(16): Simplify the C OrderedDict fast nodes resize logic.

   - bpo-24377(17): Fix a ref leak in OrderedDict.__repr__.

   - bpo-24369(18): Defend against key-changes during iteration.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21750

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24552

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24514

   (4) https://bugs.python.org/issue?@action=redirect&bpo=19176

   (5) https://bugs.python.org/issue?@action=redirect&bpo=20387

   (6) https://bugs.python.org/issue?@action=redirect&bpo=24456

   (7) https://bugs.python.org/issue?@action=redirect&bpo=24336

   (8) https://bugs.python.org/issue?@action=redirect&bpo=24522

   (9) https://bugs.python.org/issue?@action=redirect&bpo=24489

   (10) https://bugs.python.org/issue?@action=redirect&bpo=24408

   (11) https://bugs.python.org/issue?@action=redirect&bpo=14373

   (12) https://bugs.python.org/issue?@action=redirect&bpo=24347

   (13) https://bugs.python.org/issue?@action=redirect&bpo=24348

   (14) https://bugs.python.org/issue?@action=redirect&bpo=24359

   (15) https://bugs.python.org/issue?@action=redirect&bpo=24368

   (16) https://bugs.python.org/issue?@action=redirect&bpo=24362

   (17) https://bugs.python.org/issue?@action=redirect&bpo=24377

   (18) https://bugs.python.org/issue?@action=redirect&bpo=24369


File: python.info,  Node: Tests<84>,  Next: Documentation<82>,  Prev: Library<200>,  Up: Python 3 5 0 beta 3

1.24.113.3 Tests
................

   - bpo-24373(1): _testmultiphase and xxlimited now use tp_traverse and
     tp_finalize to avoid reference leaks encountered when combining
     tp_dealloc with PyType_FromSpec (see bpo-16690(2) for details)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24373

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16690


File: python.info,  Node: Documentation<82>,  Next: Build<96>,  Prev: Tests<84>,  Up: Python 3 5 0 beta 3

1.24.113.4 Documentation
........................

   - bpo-24458(1): Update documentation to cover multi-phase
     initialization for extension modules (PEP 489).  Patch by Petr
     Viktorin.

   - bpo-24351(2): Clarify what is meant by «identifier» in the context
     of string.Template instances.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24458

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24351


File: python.info,  Node: Build<96>,  Prev: Documentation<82>,  Up: Python 3 5 0 beta 3

1.24.113.5 Build
................

   - bpo-24432(1): Update Windows builds and OS X 10.5 installer to use
     OpenSSL 1.0.2c.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24432


File: python.info,  Node: Python 3 5 0 beta 2,  Next: Python 3 5 0 beta 1,  Prev: Python 3 5 0 beta 3,  Up: Changelog

1.24.114 Python 3.5.0 beta 2
----------------------------

'Release date: 2015-05-31'

* Menu:

* Core and Builtins: Core and Builtins<198>.
* Library: Library<201>.


File: python.info,  Node: Core and Builtins<198>,  Next: Library<201>,  Up: Python 3 5 0 beta 2

1.24.114.1 Core and Builtins
............................

   - bpo-24284(1): The startswith and endswith methods of the str class
     no longer return True when finding the empty string and the indexes
     are completely out of range.

   - bpo-24115(2): Update uses of PyObject_IsTrue(), PyObject_Not(),
     PyObject_IsInstance(), PyObject_RichCompareBool() and
     _PyDict_Contains() to check for and handle errors correctly.

   - bpo-24328(3): Fix importing one character extension modules.

   - bpo-11205(4): In dictionary displays, evaluate the key before the
     value.

   - bpo-24285(5): Fixed regression that prevented importing extension
     modules from inside packages.  Patch by Petr Viktorin.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24284

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24115

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24328

   (4) https://bugs.python.org/issue?@action=redirect&bpo=11205

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24285


File: python.info,  Node: Library<201>,  Prev: Core and Builtins<198>,  Up: Python 3 5 0 beta 2

1.24.114.2 Library
..................

   - bpo-23247(1): Fix a crash in the StreamWriter.reset() of CJK
     codecs.

   - bpo-24270(2): Add math.isclose() and cmath.isclose() functions as
     per PEP 485(3).  Contributed by Chris Barker and Tal Einat.

   - bpo-5633(4): Fixed timeit when the statement is a string and the
     setup is not.

   - bpo-24326(5): Fixed audioop.ratecv() with non-default weightB
     argument.  Original patch by David Moore.

   - bpo-16991(6): Add a C implementation of OrderedDict.

   - bpo-23934(7): Fix inspect.signature to fail correctly for builtin
     types lacking signature information.  Initial patch by James
     Powell.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23247

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24270

   (3) https://peps.python.org/pep-0485/

   (4) https://bugs.python.org/issue?@action=redirect&bpo=5633

   (5) https://bugs.python.org/issue?@action=redirect&bpo=24326

   (6) https://bugs.python.org/issue?@action=redirect&bpo=16991

   (7) https://bugs.python.org/issue?@action=redirect&bpo=23934


File: python.info,  Node: Python 3 5 0 beta 1,  Next: Python 3 5 0 alpha 4,  Prev: Python 3 5 0 beta 2,  Up: Changelog

1.24.115 Python 3.5.0 beta 1
----------------------------

'Release date: 2015-05-24'

* Menu:

* Core and Builtins: Core and Builtins<199>.
* Library: Library<202>.
* IDLE: IDLE<62>.
* Tests: Tests<85>.
* Documentation: Documentation<83>.
* Tools/Demos: Tools/Demos<58>.


File: python.info,  Node: Core and Builtins<199>,  Next: Library<202>,  Up: Python 3 5 0 beta 1

1.24.115.1 Core and Builtins
............................

   - bpo-24276(1): Fixed optimization of property descriptor getter.

   - bpo-24268(2): PEP 489: Multi-phase extension module initialization.
     Patch by Petr Viktorin.

   - bpo-23955(3): Add pyvenv.cfg option to suppress
     registry/environment lookup for generating sys.path on Windows.

   - bpo-24257(4): Fixed system error in the comparison of faked
     types.SimpleNamespace.

   - bpo-22939(5): Fixed integer overflow in iterator object.  Patch by
     Clement Rouault.

   - bpo-23985(6): Fix a possible buffer overrun when deleting a slice
     from the front of a bytearray and then appending some other bytes
     data.

   - bpo-24102(7): Fixed exception type checking in standard error
     handlers.

   - bpo-15027(8): The UTF-32 encoder is now 3x to 7x faster.

   - bpo-23290(9): Optimize set_merge() for cases where the target is
     empty.  (Contributed by Serhiy Storchaka.)

   - bpo-2292(10): PEP 448: Additional Unpacking Generalizations.

   - bpo-24096(11): Make warnings.warn_explicit more robust against
     mutation of the warnings.filters list.

   - bpo-23996(12): Avoid a crash when a delegated generator raises an
     unnormalized StopIteration exception.  Patch by Stefan Behnel.

   - bpo-23910(13): Optimize property() getter calls.  Patch by Joe
     Jevnik.

   - bpo-23911(14): Move path-based importlib bootstrap code to a
     separate frozen module.

   - bpo-24192(15): Fix namespace package imports.

   - bpo-24022(16): Fix tokenizer crash when processing undecodable
     source code.

   - bpo-9951(17): Added a hex() method to bytes, bytearray, and
     memoryview.

   - bpo-22906(18): PEP 479: Change StopIteration handling inside
     generators.

   - bpo-24017(19): PEP 492: Coroutines with async and await syntax.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24276

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24268

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23955

   (4) https://bugs.python.org/issue?@action=redirect&bpo=24257

   (5) https://bugs.python.org/issue?@action=redirect&bpo=22939

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23985

   (7) https://bugs.python.org/issue?@action=redirect&bpo=24102

   (8) https://bugs.python.org/issue?@action=redirect&bpo=15027

   (9) https://bugs.python.org/issue?@action=redirect&bpo=23290

   (10) https://bugs.python.org/issue?@action=redirect&bpo=2292

   (11) https://bugs.python.org/issue?@action=redirect&bpo=24096

   (12) https://bugs.python.org/issue?@action=redirect&bpo=23996

   (13) https://bugs.python.org/issue?@action=redirect&bpo=23910

   (14) https://bugs.python.org/issue?@action=redirect&bpo=23911

   (15) https://bugs.python.org/issue?@action=redirect&bpo=24192

   (16) https://bugs.python.org/issue?@action=redirect&bpo=24022

   (17) https://bugs.python.org/issue?@action=redirect&bpo=9951

   (18) https://bugs.python.org/issue?@action=redirect&bpo=22906

   (19) https://bugs.python.org/issue?@action=redirect&bpo=24017


File: python.info,  Node: Library<202>,  Next: IDLE<62>,  Prev: Core and Builtins<199>,  Up: Python 3 5 0 beta 1

1.24.115.2 Library
..................

   - bpo-14373(1): Added C implementation of functools.lru_cache().
     Based on patches by Matt Joiner and Alexey Kachayev.

   - bpo-24230(2): The tempfile module now accepts bytes for prefix,
     suffix and dir parameters and returns bytes in such situations
     (matching the os module APIs).

   - bpo-22189(3): collections.UserString now supports __getnewargs__(),
     __rmod__(), casefold(), format_map(), isprintable(), and
     maketrans().  Patch by Joe Jevnik.

   - bpo-24244(4): Prevents termination when an invalid format string is
     encountered on Windows in strftime.

   - bpo-23973(5): PEP 484: Add the typing module.

   - bpo-23086(6): The collections.abc.Sequence() abstract base class
     added 'start' and 'stop' parameters to the index() mixin.  Patch by
     Devin Jeanpierre.

   - bpo-20035(7): Replaced the ‘tkinter._fix’ module used for setting
     up the Tcl/Tk environment on Windows with a private function in the
     ‘_tkinter’ module that makes no permanent changes to the
     environment.

   - bpo-24257(8): Fixed segmentation fault in sqlite3.Row constructor
     with faked cursor type.

   - bpo-15836(9): assertRaises(), assertRaisesRegex(), assertWarns()
     and assertWarnsRegex() assertments now check the type of the first
     argument to prevent possible user error.  Based on patch by Daniel
     Wagner-Hall.

   - bpo-9858(10): Add missing method stubs to _io.RawIOBase.  Patch by
     Laura Rupprecht.

   - bpo-22955(11): attrgetter, itemgetter and methodcaller objects in
     the operator module now support pickling.  Added readable and
     evaluable repr for these objects.  Based on patch by Josh
     Rosenberg.

   - bpo-22107(12): tempfile.gettempdir() and tempfile.mkdtemp() now try
     again when a directory with the chosen name already exists on
     Windows as well as on Unix.  tempfile.mkstemp() now fails early if
     parent directory is not valid (not exists or is a file) on Windows.

   - bpo-23780(13): Improved error message in os.path.join() with single
     argument.

   - bpo-6598(14): Increased time precision and random number range in
     email.utils.make_msgid() to strengthen the uniqueness of the
     message ID.

   - bpo-24091(15): Fixed various crashes in corner cases in C
     implementation of ElementTree.

   - bpo-21931(16): msilib.FCICreate() now raises TypeError in the case
     of a bad argument instead of a ValueError with a bogus FCI error
     number.  Patch by Jeffrey Armstrong.

   - bpo-13866(17): 'quote_via' argument added to
     urllib.parse.urlencode.

   - bpo-20098(18): New mangle_from policy option for email, default
     True for compat32, but False for all other policies.

   - bpo-24211(19): The email library now supports RFC 6532: it can
     generate headers using utf-8 instead of encoded words.

   - bpo-16314(20): Added support for the LZMA compression in distutils.

   - bpo-21804(21): poplib now supports RFC 6856 (UTF8).

   - bpo-18682(22): Optimized pprint functions for builtin scalar types.

   - bpo-22027(23): smtplib now supports RFC 6531 (SMTPUTF8).

   - bpo-23488(24): Random generator objects now consume 2x less memory
     on 64-bit.

   - bpo-1322(25): platform.dist() and platform.linux_distribution()
     functions are now deprecated.  Initial patch by Vajrasky Kok.

   - bpo-22486(26): Added the math.gcd() function.  The fractions.gcd()
     function now is deprecated.  Based on patch by Mark Dickinson.

   - bpo-24064(27): Property() docstrings are now writeable.  (Patch by
     Berker Peksag.)

   - bpo-22681(28): Added support for the koi8_t encoding.

   - bpo-22682(29): Added support for the kz1048 encoding.

   - bpo-23796(30): peek and read1 methods of BufferedReader now raise
     ValueError if they called on a closed object.  Patch by John
     Hergenroeder.

   - bpo-21795(31): smtpd now supports the 8BITMIME extension whenever
     the new 'decode_data' constructor argument is set to False.

   - bpo-24155(32): optimize heapq.heapify() for better cache
     performance when heapifying large lists.

   - bpo-21800(33): imaplib now supports RFC 5161 (enable), RFC 6855
     (utf8/internationalized email) and automatically encodes non-ASCII
     usernames and passwords to UTF8.

   - bpo-20274(34): When calling a _sqlite.Connection, it now complains
     if passed any keyword arguments.  Previously it silently ignored
     them.

   - bpo-20274(35): Remove ignored and erroneous «kwargs» parameters
     from three METH_VARARGS methods on _sqlite.Connection.

   - bpo-24134(36): assertRaises(), assertRaisesRegex(), assertWarns()
     and assertWarnsRegex() checks now emits a deprecation warning when
     callable is None or keyword arguments except msg is passed in the
     context manager mode.

   - bpo-24018(37): Add a collections.abc.Generator abstract base class.
     Contributed by Stefan Behnel.

   - bpo-23880(38): Tkinter’s getint() and getdouble() now support
     Tcl_Obj.  Tkinter’s getdouble() now supports any numbers (in
     particular int).

   - bpo-22619(39): Added negative limit support in the traceback
     module.  Based on patch by Dmitry Kazakov.

   - bpo-24094(40): Fix possible crash in json.encode with poorly
     behaved dict subclasses.

   - bpo-9246(41): On POSIX, os.getcwd() now supports paths longer than
     1025 bytes.  Patch written by William Orr.

   - bpo-17445(42): add difflib.diff_bytes() to support comparison of
     byte strings (fixes a regression from Python 2).

   - bpo-23917(43): Fall back to sequential compilation when
     ProcessPoolExecutor doesn’t exist.  Patch by Claudiu Popa.

   - bpo-23008(44): Fixed resolving attributes with boolean value is
     False in pydoc.

   - Fix asyncio issue 235: LifoQueue and PriorityQueue’s put didn’t
     increment unfinished tasks (this bug was introduced when
     JoinableQueue was merged with Queue).

   - bpo-23908(45): os functions now reject paths with embedded null
     character on Windows instead of silently truncating them.

   - bpo-23728(46): binascii.crc_hqx() could return an integer outside
     of the range 0-0xffff for empty data.

   - bpo-23887(47): urllib.error.HTTPError now has a proper repr()
     representation.  Patch by Berker Peksag.

   - asyncio: New event loop APIs: set_task_factory() and
     get_task_factory().

   - asyncio: async() function is deprecated in favour of
     ensure_future().

   - bpo-24178(48): asyncio.Lock, Condition, Semaphore, and
     BoundedSemaphore support new “async with” syntax.  Contributed by
     Yury Selivanov.

   - bpo-24179(49): Support “async for” for asyncio.StreamReader.
     Contributed by Yury Selivanov.

   - bpo-24184(50): Add AsyncIterator and AsyncIterable ABCs to
     collections.abc.  Contributed by Yury Selivanov.

   - bpo-22547(51): Implement informative __repr__ for
     inspect.BoundArguments.  Contributed by Yury Selivanov.

   - bpo-24190(52): Implement inspect.BoundArgument.apply_defaults()
     method.  Contributed by Yury Selivanov.

   - bpo-20691(53): Add “follow_wrapped” argument to
     inspect.Signature.from_callable() and inspect.signature().
     Contributed by Yury Selivanov.

   - bpo-24248(54): Deprecate inspect.Signature.from_function() and
     inspect.Signature.from_builtin().

   - bpo-23898(55): Fix inspect.classify_class_attrs() to support
     attributes with overloaded __eq__ and __bool__.  Patch by Mike
     Bayer.

   - bpo-24298(56): Fix inspect.signature() to correctly unwrap wrappers
     around bound methods.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14373

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24230

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22189

   (4) https://bugs.python.org/issue?@action=redirect&bpo=24244

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23973

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23086

   (7) https://bugs.python.org/issue?@action=redirect&bpo=20035

   (8) https://bugs.python.org/issue?@action=redirect&bpo=24257

   (9) https://bugs.python.org/issue?@action=redirect&bpo=15836

   (10) https://bugs.python.org/issue?@action=redirect&bpo=9858

   (11) https://bugs.python.org/issue?@action=redirect&bpo=22955

   (12) https://bugs.python.org/issue?@action=redirect&bpo=22107

   (13) https://bugs.python.org/issue?@action=redirect&bpo=23780

   (14) https://bugs.python.org/issue?@action=redirect&bpo=6598

   (15) https://bugs.python.org/issue?@action=redirect&bpo=24091

   (16) https://bugs.python.org/issue?@action=redirect&bpo=21931

   (17) https://bugs.python.org/issue?@action=redirect&bpo=13866

   (18) https://bugs.python.org/issue?@action=redirect&bpo=20098

   (19) https://bugs.python.org/issue?@action=redirect&bpo=24211

   (20) https://bugs.python.org/issue?@action=redirect&bpo=16314

   (21) https://bugs.python.org/issue?@action=redirect&bpo=21804

   (22) https://bugs.python.org/issue?@action=redirect&bpo=18682

   (23) https://bugs.python.org/issue?@action=redirect&bpo=22027

   (24) https://bugs.python.org/issue?@action=redirect&bpo=23488

   (25) https://bugs.python.org/issue?@action=redirect&bpo=1322

   (26) https://bugs.python.org/issue?@action=redirect&bpo=22486

   (27) https://bugs.python.org/issue?@action=redirect&bpo=24064

   (28) https://bugs.python.org/issue?@action=redirect&bpo=22681

   (29) https://bugs.python.org/issue?@action=redirect&bpo=22682

   (30) https://bugs.python.org/issue?@action=redirect&bpo=23796

   (31) https://bugs.python.org/issue?@action=redirect&bpo=21795

   (32) https://bugs.python.org/issue?@action=redirect&bpo=24155

   (33) https://bugs.python.org/issue?@action=redirect&bpo=21800

   (34) https://bugs.python.org/issue?@action=redirect&bpo=20274

   (35) https://bugs.python.org/issue?@action=redirect&bpo=20274

   (36) https://bugs.python.org/issue?@action=redirect&bpo=24134

   (37) https://bugs.python.org/issue?@action=redirect&bpo=24018

   (38) https://bugs.python.org/issue?@action=redirect&bpo=23880

   (39) https://bugs.python.org/issue?@action=redirect&bpo=22619

   (40) https://bugs.python.org/issue?@action=redirect&bpo=24094

   (41) https://bugs.python.org/issue?@action=redirect&bpo=9246

   (42) https://bugs.python.org/issue?@action=redirect&bpo=17445

   (43) https://bugs.python.org/issue?@action=redirect&bpo=23917

   (44) https://bugs.python.org/issue?@action=redirect&bpo=23008

   (45) https://bugs.python.org/issue?@action=redirect&bpo=23908

   (46) https://bugs.python.org/issue?@action=redirect&bpo=23728

   (47) https://bugs.python.org/issue?@action=redirect&bpo=23887

   (48) https://bugs.python.org/issue?@action=redirect&bpo=24178

   (49) https://bugs.python.org/issue?@action=redirect&bpo=24179

   (50) https://bugs.python.org/issue?@action=redirect&bpo=24184

   (51) https://bugs.python.org/issue?@action=redirect&bpo=22547

   (52) https://bugs.python.org/issue?@action=redirect&bpo=24190

   (53) https://bugs.python.org/issue?@action=redirect&bpo=20691

   (54) https://bugs.python.org/issue?@action=redirect&bpo=24248

   (55) https://bugs.python.org/issue?@action=redirect&bpo=23898

   (56) https://bugs.python.org/issue?@action=redirect&bpo=24298


File: python.info,  Node: IDLE<62>,  Next: Tests<85>,  Prev: Library<202>,  Up: Python 3 5 0 beta 1

1.24.115.3 IDLE
...............

   - bpo-23184(1): remove unused names and imports in idlelib.  Initial
     patch by Al Sweigart.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23184


File: python.info,  Node: Tests<85>,  Next: Documentation<83>,  Prev: IDLE<62>,  Up: Python 3 5 0 beta 1

1.24.115.4 Tests
................

   - bpo-21520(1): test_zipfile no longer fails if the word “bad”
     appears anywhere in the name of the current directory.

   - bpo-9517(2): Move script_helper into the support package.  Patch by
     Christie Wilson.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=21520

   (2) https://bugs.python.org/issue?@action=redirect&bpo=9517


File: python.info,  Node: Documentation<83>,  Next: Tools/Demos<58>,  Prev: Tests<85>,  Up: Python 3 5 0 beta 1

1.24.115.5 Documentation
........................

   - bpo-22155(1): Add File Handlers subsection with createfilehandler
     to tkinter doc.  Remove obsolete example from FAQ. Patch by Martin
     Panter.

   - bpo-24029(2): Document the name binding behavior for submodule
     imports.

   - bpo-24077(3): Fix typo in man page for -I command option: -s, not
     -S

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22155

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24029

   (3) https://bugs.python.org/issue?@action=redirect&bpo=24077


File: python.info,  Node: Tools/Demos<58>,  Prev: Documentation<83>,  Up: Python 3 5 0 beta 1

1.24.115.6 Tools/Demos
......................

   - bpo-24000(1): Improved Argument Clinic’s mapping of converters to
     legacy «format units».  Updated the documentation to match.

   - bpo-24001(2): Argument Clinic converters now use accept={type}
     instead of types={“type”} to specify the types the converter
     accepts.

   - bpo-23330(3): h2py now supports arbitrary filenames in #include.

   - bpo-24031(4): make patchcheck now supports git checkouts, too.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=24000

   (2) https://bugs.python.org/issue?@action=redirect&bpo=24001

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23330

   (4) https://bugs.python.org/issue?@action=redirect&bpo=24031


File: python.info,  Node: Python 3 5 0 alpha 4,  Next: Python 3 5 0 alpha 3,  Prev: Python 3 5 0 beta 1,  Up: Changelog

1.24.116 Python 3.5.0 alpha 4
-----------------------------

'Release date: 2015-04-19'

* Menu:

* Core and Builtins: Core and Builtins<200>.
* Library: Library<203>.
* Build: Build<97>.
* Tests: Tests<86>.
* Tools/Demos: Tools/Demos<59>.
* C API: C API<77>.


File: python.info,  Node: Core and Builtins<200>,  Next: Library<203>,  Up: Python 3 5 0 alpha 4

1.24.116.1 Core and Builtins
............................

   - bpo-22980(1): Under Linux, GNU/KFreeBSD and the Hurd, C extensions
     now include the architecture triplet in the extension name, to make
     it easy to test builds for different ABIs in the same working tree.
     Under OS X, the extension name now includes PEP 3149(2)-style
     information.

   - bpo-22631(3): Added Linux-specific socket constant
     CAN_RAW_FD_FRAMES. Patch courtesy of Joe Jevnik.

   - bpo-23731(4): Implement PEP 488(5): removal of .pyo files.

   - bpo-23726(6): Don’t enable GC for user subclasses of non-GC types
     that don’t add any new fields.  Patch by Eugene Toder.

   - bpo-23309(7): Avoid a deadlock at shutdown if a daemon thread is
     aborted while it is holding a lock to a buffered I/O object, and
     the main thread tries to use the same I/O object (typically stdout
     or stderr).  A fatal error is emitted instead.

   - bpo-22977(8): Fixed formatting Windows error messages on Wine.
     Patch by Martin Panter.

   - bpo-23466(9): %c, %o, %x, and %X in bytes formatting now raise
     TypeError on non-integer input.

   - bpo-24044(10): Fix possible null pointer dereference in list.sort
     in out of memory conditions.

   - bpo-21354(11): PyCFunction_New function is exposed by python DLL
     again.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22980

   (2) https://peps.python.org/pep-3149/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22631

   (4) https://bugs.python.org/issue?@action=redirect&bpo=23731

   (5) https://peps.python.org/pep-0488/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23726

   (7) https://bugs.python.org/issue?@action=redirect&bpo=23309

   (8) https://bugs.python.org/issue?@action=redirect&bpo=22977

   (9) https://bugs.python.org/issue?@action=redirect&bpo=23466

   (10) https://bugs.python.org/issue?@action=redirect&bpo=24044

   (11) https://bugs.python.org/issue?@action=redirect&bpo=21354


File: python.info,  Node: Library<203>,  Next: Build<97>,  Prev: Core and Builtins<200>,  Up: Python 3 5 0 alpha 4

1.24.116.2 Library
..................

   - bpo-23840(1): tokenize.open() now closes the temporary binary file
     on error to fix a resource warning.

   - bpo-16914(2): new debuglevel 2 in smtplib adds timestamps to debug
     output.

   - bpo-7159(3): urllib.request now supports sending auth credentials
     automatically after the first 401.  This enhancement is a superset
     of the enhancement from bpo-19494(4) and supersedes that change.

   - bpo-23703(5): Fix a regression in urljoin() introduced in
     901e4e52b20a.  Patch by Demian Brecht.

   - bpo-4254(6): Adds _curses.update_lines_cols().  Patch by Arnon
     Yaari

   - bpo-19933(7): Provide default argument for ndigits in round.  Patch
     by Vajrasky Kok.

   - bpo-23193(8): Add a numeric_owner parameter to
     tarfile.TarFile.extract and tarfile.TarFile.extractall.  Patch by
     Michael Vogt and Eric Smith.

   - bpo-23342(9): Add a subprocess.run() function than returns a
     CalledProcess instance for a more consistent API than the existing
     call* functions.

   - bpo-21217(10): inspect.getsourcelines() now tries to compute the
     start and end lines from the code object, fixing an issue when a
     lambda function is used as decorator argument.  Patch by Thomas
     Ballinger and Allison Kaptur.

   - bpo-24521(11): Fix possible integer overflows in the pickle module.

   - bpo-22931(12): Allow “[” and “]” in cookie values.

   - The keywords attribute of functools.partial is now always a
     dictionary.

   - bpo-23811(13): Add missing newline to the PyCompileError error
     message.  Patch by Alex Shkop.

   - bpo-21116(14): Avoid blowing memory when allocating a
     multiprocessing shared array that’s larger than 50% of the
     available RAM. Patch by Médéric Boquien.

   - bpo-22982(15): Improve BOM handling when seeking to multiple
     positions of a writable text file.

   - bpo-23464(16): Removed deprecated asyncio JoinableQueue.

   - bpo-23529(17): Limit the size of decompressed data when reading
     from GzipFile, BZ2File or LZMAFile.  This defeats denial of service
     attacks using compressed bombs (i.e.  compressed payloads which
     decompress to a huge size).  Patch by Martin Panter and Nikolaus
     Rath.

   - bpo-21859(18): Added Python implementation of io.FileIO.

   - bpo-23865(19): close() methods in multiple modules now are
     idempotent and more robust at shutdown.  If they need to release
     multiple resources, all are released even if errors occur.

   - bpo-23400(20): Raise same exception on both Python 2 and 3 if
     sem_open is not available.  Patch by Davin Potts.

   - bpo-10838(21): The subprocess now module includes SubprocessError
     and TimeoutError in its list of exported names for the users wild
     enough to use ‘from subprocess import *’.

   - bpo-23411(22): Added DefragResult, ParseResult, SplitResult,
     DefragResultBytes, ParseResultBytes, and SplitResultBytes to
     urllib.parse.__all__.  Patch by Martin Panter.

   - bpo-23881(23): urllib.request.ftpwrapper constructor now closes the
     socket if the FTP connection failed to fix a ResourceWarning.

   - bpo-23853(24): *note socket.socket.sendall(): faa. does no more
     reset the socket timeout each time data is sent successfully.  The
     socket timeout is now the maximum total duration to send all data.

   - bpo-22721(25): An order of multiline pprint output of set or dict
     containing orderable and non-orderable elements no longer depends
     on iteration order of set or dict.

   - bpo-15133(26): _tkinter.tkapp.getboolean() now supports Tcl_Obj and
     always returns bool.  tkinter.BooleanVar now validates input values
     (accepted bool, int, str, and Tcl_Obj).  tkinter.BooleanVar.get()
     now always returns bool.

   - bpo-10590(27): xml.sax.parseString() now supports string argument.

   - bpo-23338(28): Fixed formatting ctypes error messages on Cygwin.
     Patch by Makoto Kato.

   - bpo-15582(29): inspect.getdoc() now follows inheritance chains.

   - bpo-2175(30): SAX parsers now support a character stream of
     InputSource object.

   - bpo-16840(31): Tkinter now supports 64-bit integers added in Tcl
     8.4 and arbitrary precision integers added in Tcl 8.5.

   - bpo-23834(32): Fix socket.sendto(), use the C Py_ssize_t type to
     store the result of sendto() instead of the C int type.

   - bpo-23618(33): *note socket.socket.connect(): fa5. now waits until
     the connection completes instead of raising *note InterruptedError:
     f8a. if the connection is interrupted by signals, signal handlers
     don’t raise an exception and the socket is blocking or has a
     timeout.  *note socket.socket.connect(): fa5. still raise *note
     InterruptedError: f8a. for non-blocking sockets.

   - bpo-21526(34): Tkinter now supports new boolean type in Tcl 8.5.

   - bpo-23836(35): Fix the faulthandler module to handle reentrant
     calls to its signal handlers.

   - bpo-23838(36): linecache now clears the cache and returns an empty
     result on MemoryError.

   - bpo-10395(37): Added os.path.commonpath().  Implemented in
     posixpath and ntpath.  Based on patch by Rafik Draoui.

   - bpo-23611(38): Serializing more «lookupable» objects (such as
     unbound methods or nested classes) now are supported with pickle
     protocols < 4.

   - bpo-13583(39): sqlite3.Row now supports slice indexing.

   - bpo-18473(40): Fixed 2to3 and 3to2 compatible pickle mappings.
     Fixed ambiguous reverse mappings.  Added many new mappings.  Import
     mapping is no longer applied to modules already mapped with full
     name mapping.

   - bpo-23485(41): select.select() is now retried automatically with
     the recomputed timeout when interrupted by a signal, except if the
     signal handler raises an exception.  This change is part of the PEP
     475(42).

   - bpo-23752(43): When built from an existing file descriptor,
     io.FileIO() now only calls fstat() once.  Before fstat() was called
     twice, which was not necessary.

   - bpo-23704(44): collections.deque() objects now support __add__,
     __mul__, and __imul__().

   - bpo-23171(45): csv.Writer.writerow() now supports arbitrary
     iterables.

   - bpo-23745(46): The new email header parser now handles duplicate
     MIME parameter names without error, similar to how get_param
     behaves.

   - bpo-22117(47): Fix os.utime(), it now rounds the timestamp towards
     minus infinity (-inf) instead of rounding towards zero.

   - bpo-23310(48): Fix MagicMock’s initializer to work with
     __methods__, just like configure_mock().  Patch by Kasia Jachim.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23840

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16914

   (3) https://bugs.python.org/issue?@action=redirect&bpo=7159

   (4) https://bugs.python.org/issue?@action=redirect&bpo=19494

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23703

   (6) https://bugs.python.org/issue?@action=redirect&bpo=4254

   (7) https://bugs.python.org/issue?@action=redirect&bpo=19933

   (8) https://bugs.python.org/issue?@action=redirect&bpo=23193

   (9) https://bugs.python.org/issue?@action=redirect&bpo=23342

   (10) https://bugs.python.org/issue?@action=redirect&bpo=21217

   (11) https://bugs.python.org/issue?@action=redirect&bpo=24521

   (12) https://bugs.python.org/issue?@action=redirect&bpo=22931

   (13) https://bugs.python.org/issue?@action=redirect&bpo=23811

   (14) https://bugs.python.org/issue?@action=redirect&bpo=21116

   (15) https://bugs.python.org/issue?@action=redirect&bpo=22982

   (16) https://bugs.python.org/issue?@action=redirect&bpo=23464

   (17) https://bugs.python.org/issue?@action=redirect&bpo=23529

   (18) https://bugs.python.org/issue?@action=redirect&bpo=21859

   (19) https://bugs.python.org/issue?@action=redirect&bpo=23865

   (20) https://bugs.python.org/issue?@action=redirect&bpo=23400

   (21) https://bugs.python.org/issue?@action=redirect&bpo=10838

   (22) https://bugs.python.org/issue?@action=redirect&bpo=23411

   (23) https://bugs.python.org/issue?@action=redirect&bpo=23881

   (24) https://bugs.python.org/issue?@action=redirect&bpo=23853

   (25) https://bugs.python.org/issue?@action=redirect&bpo=22721

   (26) https://bugs.python.org/issue?@action=redirect&bpo=15133

   (27) https://bugs.python.org/issue?@action=redirect&bpo=10590

   (28) https://bugs.python.org/issue?@action=redirect&bpo=23338

   (29) https://bugs.python.org/issue?@action=redirect&bpo=15582

   (30) https://bugs.python.org/issue?@action=redirect&bpo=2175

   (31) https://bugs.python.org/issue?@action=redirect&bpo=16840

   (32) https://bugs.python.org/issue?@action=redirect&bpo=23834

   (33) https://bugs.python.org/issue?@action=redirect&bpo=23618

   (34) https://bugs.python.org/issue?@action=redirect&bpo=21526

   (35) https://bugs.python.org/issue?@action=redirect&bpo=23836

   (36) https://bugs.python.org/issue?@action=redirect&bpo=23838

   (37) https://bugs.python.org/issue?@action=redirect&bpo=10395

   (38) https://bugs.python.org/issue?@action=redirect&bpo=23611

   (39) https://bugs.python.org/issue?@action=redirect&bpo=13583

   (40) https://bugs.python.org/issue?@action=redirect&bpo=18473

   (41) https://bugs.python.org/issue?@action=redirect&bpo=23485

   (42) https://peps.python.org/pep-0475/

   (43) https://bugs.python.org/issue?@action=redirect&bpo=23752

   (44) https://bugs.python.org/issue?@action=redirect&bpo=23704

   (45) https://bugs.python.org/issue?@action=redirect&bpo=23171

   (46) https://bugs.python.org/issue?@action=redirect&bpo=23745

   (47) https://bugs.python.org/issue?@action=redirect&bpo=22117

   (48) https://bugs.python.org/issue?@action=redirect&bpo=23310


File: python.info,  Node: Build<97>,  Next: Tests<86>,  Prev: Library<203>,  Up: Python 3 5 0 alpha 4

1.24.116.3 Build
................

   - bpo-23817(1): FreeBSD now uses «1.0» in the SOVERSION as other
     operating systems, instead of just «1».

   - bpo-23501(2): Argument Clinic now generates code into separate
     files by default.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23817

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23501


File: python.info,  Node: Tests<86>,  Next: Tools/Demos<59>,  Prev: Build<97>,  Up: Python 3 5 0 alpha 4

1.24.116.4 Tests
................

   - bpo-23799(1): Added test.support.start_threads() for running and
     cleaning up multiple threads.

   - bpo-22390(2): test.regrtest now emits a warning if temporary files
     or directories are left after running a test.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23799

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22390


File: python.info,  Node: Tools/Demos<59>,  Next: C API<77>,  Prev: Tests<86>,  Up: Python 3 5 0 alpha 4

1.24.116.5 Tools/Demos
......................

   - bpo-18128(1): pygettext now uses standard +NNNN format in the
     POT-Creation-Date header.

   - bpo-23935(2): Argument Clinic’s understanding of format units
     accepting bytes, bytearrays, and buffers is now consistent with
     both the documentation and the implementation.

   - bpo-23944(3): Argument Clinic now wraps long impl prototypes at
     column 78.

   - bpo-20586(4): Argument Clinic now ensures that functions without
     docstrings have signatures.

   - bpo-23492(5): Argument Clinic now generates argument parsing code
     with PyArg_Parse instead of PyArg_ParseTuple if possible.

   - bpo-23500(6): Argument Clinic is now smarter about generating the
     «#ifndef» (empty) definition of the methoddef macro: it’s only
     generated once, even if Argument Clinic processes the same symbol
     multiple times, and it’s emitted at the end of all processing
     rather than immediately after the first use.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18128

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23935

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23944

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20586

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23492

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23500


File: python.info,  Node: C API<77>,  Prev: Tools/Demos<59>,  Up: Python 3 5 0 alpha 4

1.24.116.6 C API
................

   - bpo-23998(1): PyImport_ReInitLock() now checks for lock allocation
     error

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23998


File: python.info,  Node: Python 3 5 0 alpha 3,  Next: Python 3 5 0 alpha 2,  Prev: Python 3 5 0 alpha 4,  Up: Changelog

1.24.117 Python 3.5.0 alpha 3
-----------------------------

'Release date: 2015-03-28'

* Menu:

* Core and Builtins: Core and Builtins<201>.
* Library: Library<204>.
* Build: Build<98>.
* Tests: Tests<87>.
* Tools/Demos: Tools/Demos<60>.


File: python.info,  Node: Core and Builtins<201>,  Next: Library<204>,  Up: Python 3 5 0 alpha 3

1.24.117.1 Core and Builtins
............................

   - bpo-23573(1): Increased performance of string search operations
     (str.find, str.index, str.count, the in operator, str.split,
     str.partition) with arguments of different kinds (UCS1, UCS2,
     UCS4).

   - bpo-23753(2): Python doesn’t support anymore platforms without
     stat() or fstat(), these functions are always required.

   - bpo-23681(3): The -b option now affects comparisons of bytes with
     int.

   - bpo-23632(4): Memoryviews now allow tuple indexing (including for
     multi-dimensional memoryviews).

   - bpo-23192(5): Fixed generator lambdas.  Patch by Bruno Cauet.

   - bpo-23629(6): Fix the default __sizeof__ implementation for
     variable-sized objects.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23573

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23753

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23681

   (4) https://bugs.python.org/issue?@action=redirect&bpo=23632

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23192

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23629


File: python.info,  Node: Library<204>,  Next: Build<98>,  Prev: Core and Builtins<201>,  Up: Python 3 5 0 alpha 3

1.24.117.2 Library
..................

   - bpo-14260(1): The groupindex attribute of regular expression
     pattern object now is non-modifiable mapping.

   - bpo-23792(2): Ignore KeyboardInterrupt when the pydoc pager is
     active.  This mimics the behavior of the standard unix pagers, and
     prevents pipepager from shutting down while the pager itself is
     still running.

   - bpo-23775(3): pprint() of OrderedDict now outputs the same
     representation as repr().

   - bpo-23765(4): Removed IsBadStringPtr calls in ctypes

   - bpo-22364(5): Improved some re error messages using regex for
     hints.

   - bpo-23742(6): ntpath.expandvars() no longer loses unbalanced single
     quotes.

   - bpo-21717(7): The zipfile.ZipFile.open function now supports “x”
     (exclusive creation) mode.

   - bpo-21802(8): The reader in BufferedRWPair now is closed even when
     closing writer failed in BufferedRWPair.close().

   - bpo-23622(9): Unknown escapes in regular expressions that consist
     of ‘'\'’ and ASCII letter now raise a deprecation warning and will
     be forbidden in Python 3.6.

   - bpo-23671(10): string.Template now allows specifying the «self»
     parameter as a keyword argument.  string.Formatter now allows
     specifying the «self» and the «format_string» parameters as keyword
     arguments.

   - bpo-23502(11): The pprint module now supports mapping proxies.

   - bpo-17530(12): pprint now wraps long bytes objects and bytearrays.

   - bpo-22687(13): Fixed some corner cases in breaking words in
     tetxtwrap.  Got rid of quadratic complexity in breaking long words.

   - bpo-4727(14): The copy module now uses pickle protocol 4 (PEP 3154)
     and supports copying of instances of classes whose __new__ method
     takes keyword-only arguments.

   - bpo-23491(15): Added a zipapp module to support creating executable
     zip file archives of Python code.  Registered «.pyz» and «.pyzw»
     extensions on Windows for these archives (PEP 441).

   - bpo-23657(16): Avoid explicit checks for str in zipapp, adding
     support for pathlib.Path objects as arguments.

   - bpo-23688(17): Added support of arbitrary bytes-like objects and
     avoided unnecessary copying of memoryview in gzip.GzipFile.write().
     Original patch by Wolfgang Maier.

   - bpo-23252(18): Added support for writing ZIP files to unseekable
     streams.

   - bpo-23647(19): Increase imaplib’s MAXLINE to accommodate modern
     mailbox sizes.

   - bpo-23539(20): If body is None, http.client.HTTPConnection.request
     now sets Content-Length to 0 for PUT, POST, and PATCH headers to
     avoid 411 errors from some web servers.

   - bpo-22351(21): The nntplib.NNTP constructor no longer leaves the
     connection and socket open until the garbage collector cleans them
     up.  Patch by Martin Panter.

   - bpo-23704(22): collections.deque() objects now support methods for
     index(), insert(), and copy().  This allows deques to be registered
     as a MutableSequence and it improves their substitutability for
     lists.

   - bpo-23715(23): *note signal.sigwaitinfo(): fad. and *note
     signal.sigtimedwait(): fac. are now retried when interrupted by a
     signal not in the 'sigset' parameter, if the signal handler does
     not raise an exception.  signal.sigtimedwait() recomputes the
     timeout with a monotonic clock when it is retried.

   - bpo-23001(24): Few functions in modules mmap, ossaudiodev, socket,
     ssl, and codecs, that accepted only read-only bytes-like object now
     accept writable bytes-like object too.

   - bpo-23646(25): If time.sleep() is interrupted by a signal, the
     sleep is now retried with the recomputed delay, except if the
     signal handler raises an exception (PEP 475).

   - bpo-23136(26): _strptime now uniformly handles all days in week 0,
     including Dec 30 of previous year.  Based on patch by Jim Carroll.

   - bpo-23700(27): Iterator of NamedTemporaryFile now keeps a reference
     to NamedTemporaryFile instance.  Patch by Bohuslav Kabrda.

   - bpo-22903(28): The fake test case created by unittest.loader when
     it fails importing a test module is now picklable.

   - bpo-22181(29): On Linux, os.urandom() now uses the new getrandom()
     syscall if available, syscall introduced in the Linux kernel 3.17.
     It is more reliable and more secure, because it avoids the need of
     a file descriptor and waits until the kernel has enough entropy.

   - bpo-2211(30): Updated the implementation of the http.cookies.Morsel
     class.  Setting attributes key, value and coded_value directly now
     is deprecated.  update() and setdefault() now transform and check
     keys.  Comparing for equality now takes into account attributes
     key, value and coded_value.  copy() now returns a Morsel, not a
     dict.  repr() now contains all attributes.  Optimized checking keys
     and quoting values.  Added new tests.  Original patch by Demian
     Brecht.

   - bpo-18983(31): Allow selection of output units in timeit.  Patch by
     Julian Gindi.

   - bpo-23631(32): Fix traceback.format_list when a traceback has been
     mutated.

   - bpo-23568(33): Add rdivmod support to MagicMock() objects.  Patch
     by Håkan Lövdahl.

   - bpo-2052(34): Add charset parameter to HtmlDiff.make_file().

   - bpo-23668(35): Support os.truncate and os.ftruncate on Windows.

   - bpo-23138(36): Fixed parsing cookies with absent keys or values in
     cookiejar.  Patch by Demian Brecht.

   - bpo-23051(37): multiprocessing.Pool methods imap() and
     imap_unordered() now handle exceptions raised by an iterator.
     Patch by Alon Diamant and Davin Potts.

   - bpo-23581(38): Add matmul support to MagicMock.  Patch by Håkan
     Lövdahl.

   - bpo-23566(39): enable(), register(), dump_traceback() and
     dump_traceback_later() functions of faulthandler now accept file
     descriptors.  Patch by Wei Wu.

   - bpo-22928(40): Disabled HTTP header injections in http.client.
     Original patch by Demian Brecht.

   - bpo-23615(41): Modules bz2, tarfile and tokenize now can be
     reloaded with imp.reload().  Patch by Thomas Kluyver.

   - bpo-23605(42): os.walk() now calls os.scandir() instead of
     os.listdir().  The usage of os.scandir() reduces the number of
     calls to os.stat().  Initial patch written by Ben Hoyt.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14260

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23792

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23775

   (4) https://bugs.python.org/issue?@action=redirect&bpo=23765

   (5) https://bugs.python.org/issue?@action=redirect&bpo=22364

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23742

   (7) https://bugs.python.org/issue?@action=redirect&bpo=21717

   (8) https://bugs.python.org/issue?@action=redirect&bpo=21802

   (9) https://bugs.python.org/issue?@action=redirect&bpo=23622

   (10) https://bugs.python.org/issue?@action=redirect&bpo=23671

   (11) https://bugs.python.org/issue?@action=redirect&bpo=23502

   (12) https://bugs.python.org/issue?@action=redirect&bpo=17530

   (13) https://bugs.python.org/issue?@action=redirect&bpo=22687

   (14) https://bugs.python.org/issue?@action=redirect&bpo=4727

   (15) https://bugs.python.org/issue?@action=redirect&bpo=23491

   (16) https://bugs.python.org/issue?@action=redirect&bpo=23657

   (17) https://bugs.python.org/issue?@action=redirect&bpo=23688

   (18) https://bugs.python.org/issue?@action=redirect&bpo=23252

   (19) https://bugs.python.org/issue?@action=redirect&bpo=23647

   (20) https://bugs.python.org/issue?@action=redirect&bpo=23539

   (21) https://bugs.python.org/issue?@action=redirect&bpo=22351

   (22) https://bugs.python.org/issue?@action=redirect&bpo=23704

   (23) https://bugs.python.org/issue?@action=redirect&bpo=23715

   (24) https://bugs.python.org/issue?@action=redirect&bpo=23001

   (25) https://bugs.python.org/issue?@action=redirect&bpo=23646

   (26) https://bugs.python.org/issue?@action=redirect&bpo=23136

   (27) https://bugs.python.org/issue?@action=redirect&bpo=23700

   (28) https://bugs.python.org/issue?@action=redirect&bpo=22903

   (29) https://bugs.python.org/issue?@action=redirect&bpo=22181

   (30) https://bugs.python.org/issue?@action=redirect&bpo=2211

   (31) https://bugs.python.org/issue?@action=redirect&bpo=18983

   (32) https://bugs.python.org/issue?@action=redirect&bpo=23631

   (33) https://bugs.python.org/issue?@action=redirect&bpo=23568

   (34) https://bugs.python.org/issue?@action=redirect&bpo=2052

   (35) https://bugs.python.org/issue?@action=redirect&bpo=23668

   (36) https://bugs.python.org/issue?@action=redirect&bpo=23138

   (37) https://bugs.python.org/issue?@action=redirect&bpo=23051

   (38) https://bugs.python.org/issue?@action=redirect&bpo=23581

   (39) https://bugs.python.org/issue?@action=redirect&bpo=23566

   (40) https://bugs.python.org/issue?@action=redirect&bpo=22928

   (41) https://bugs.python.org/issue?@action=redirect&bpo=23615

   (42) https://bugs.python.org/issue?@action=redirect&bpo=23605


File: python.info,  Node: Build<98>,  Next: Tests<87>,  Prev: Library<204>,  Up: Python 3 5 0 alpha 3

1.24.117.3 Build
................

   - bpo-23585(1): make patchcheck will ensure the interpreter is built.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23585


File: python.info,  Node: Tests<87>,  Next: Tools/Demos<60>,  Prev: Build<98>,  Up: Python 3 5 0 alpha 3

1.24.117.4 Tests
................

   - bpo-23583(1): Added tests for standard IO streams in IDLE.

   - bpo-22289(2): Prevent test_urllib2net failures due to ftp
     connection timeout.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23583

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22289


File: python.info,  Node: Tools/Demos<60>,  Prev: Tests<87>,  Up: Python 3 5 0 alpha 3

1.24.117.5 Tools/Demos
......................

   - bpo-22826(1): The result of open() in Tools/freeze/bkfile.py is now
     better compatible with regular files (in particular it now supports
     the context management protocol).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22826


File: python.info,  Node: Python 3 5 0 alpha 2,  Next: Python 3 5 0 alpha 1,  Prev: Python 3 5 0 alpha 3,  Up: Changelog

1.24.118 Python 3.5.0 alpha 2
-----------------------------

'Release date: 2015-03-09'

* Menu:

* Core and Builtins: Core and Builtins<202>.
* Library: Library<205>.
* Build: Build<99>.
* C API: C API<78>.
* Windows: Windows<81>.


File: python.info,  Node: Core and Builtins<202>,  Next: Library<205>,  Up: Python 3 5 0 alpha 2

1.24.118.1 Core and Builtins
............................

   - bpo-23571(1): PyObject_Call() and PyCFunction_Call() now raise a
     SystemError if a function returns a result and raises an exception.
     The SystemError is chained to the previous exception.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23571


File: python.info,  Node: Library<205>,  Next: Build<99>,  Prev: Core and Builtins<202>,  Up: Python 3 5 0 alpha 2

1.24.118.2 Library
..................

   - bpo-22524(1): New os.scandir() function, part of the PEP 471(2):
     «os.scandir() function – a better and faster directory iterator».
     Patch written by Ben Hoyt.

   - bpo-23103(3): Reduced the memory consumption of IPv4Address and
     IPv6Address.

   - bpo-21793(4): BaseHTTPRequestHandler again logs response code as
     numeric, not as stringified enum.  Patch by Demian Brecht.

   - bpo-23476(5): In the ssl module, enable OpenSSL’s
     X509_V_FLAG_TRUSTED_FIRST flag on certificate stores when it is
     available.

   - bpo-23576(6): Avoid stalling in SSL reads when EOF has been reached
     in the SSL layer but the underlying connection hasn’t been closed.

   - bpo-23504(7): Added an __all__ to the types module.

   - bpo-23563(8): Optimized utility functions in urllib.parse.

   - bpo-7830(9): Flatten nested functools.partial.

   - bpo-20204(10): Added the __module__ attribute to _tkinter classes.

   - bpo-19980(11): Improved help() for non-recognized strings.
     help(“”) now shows the help on str.  help(“help”) now shows the
     help on help().  Original patch by Mark Lawrence.

   - bpo-23521(12): Corrected pure python implementation of timedelta
     division.  Eliminated OverflowError from ‘timedelta * float’ for
     some floats; Corrected rounding in timedelta true division.

   - bpo-21619(13): Popen objects no longer leave a zombie after exit in
     the with statement if the pipe was broken.  Patch by Martin Panter.

   - bpo-22936(14): Make it possible to show local variables in
     tracebacks for both the traceback module and unittest.

   - bpo-15955(15): Add an option to limit the output size in
     bz2.decompress().  Patch by Nikolaus Rath.

   - bpo-6639(16): Module-level turtle functions no longer raise
     TclError after closing the window.

   - bpo-814253(17): Group references and conditional group references
     now work in lookbehind assertions in regular expressions.  (See
     also: bpo-9179(18))

   - bpo-23215(19): Multibyte codecs with custom error handlers that
     ignores errors consumed too much memory and raised SystemError or
     MemoryError.  Original patch by Aleksi Torhamo.

   - bpo-5700(20): io.FileIO() called flush() after closing the file.
     flush() was not called in close() if closefd=False.

   - bpo-23374(21): Fixed pydoc failure with non-ASCII files when stdout
     encoding differs from file system encoding (e.g.  on Mac OS).

   - bpo-23481(22): Remove RC4 from the SSL module’s default cipher
     list.

   - bpo-21548(23): Fix pydoc.synopsis() and pydoc.apropos() on modules
     with empty docstrings.

   - bpo-22885(24): Fixed arbitrary code execution vulnerability in the
     dbm.dumb module.  Original patch by Claudiu Popa.

   - bpo-23239(25): ssl.match_hostname() now supports matching of IP
     addresses.

   - bpo-23146(26): Fix mishandling of absolute Windows paths with
     forward slashes in pathlib.

   - bpo-23096(27): Pickle representation of floats with protocol 0 now
     is the same for both Python and C implementations.

   - bpo-19105(28): pprint now more efficiently uses free space at the
     right.

   - bpo-14910(29): Add allow_abbrev parameter to
     argparse.ArgumentParser.  Patch by Jonathan Paugh, Steven Bethard,
     paul j3 and Daniel Eriksson.

   - bpo-21717(30): tarfile.open() now supports “x” (exclusive creation)
     mode.

   - bpo-23344(31): marshal.dumps() is now 20-25% faster on average.

   - bpo-20416(32): marshal.dumps() with protocols 3 and 4 is now 40-50%
     faster on average.

   - bpo-23421(33): Fixed compression in tarfile CLI. Patch by wdv4758h.

   - bpo-23367(34): Fix possible overflows in the unicodedata module.

   - bpo-23361(35): Fix possible overflow in Windows subprocess creation
     code.

   - logging.handlers.QueueListener now takes a respect_handler_level
     keyword argument which, if set to True, will pass messages to
     handlers taking handler levels into account.

   - bpo-19705(36): turtledemo now has a visual sorting algorithm demo.
     Original patch from Jason Yeo.

   - bpo-23801(37): Fix issue where cgi.FieldStorage did not always
     ignore the entire preamble to a multipart body.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22524

   (2) https://peps.python.org/pep-0471/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23103

   (4) https://bugs.python.org/issue?@action=redirect&bpo=21793

   (5) https://bugs.python.org/issue?@action=redirect&bpo=23476

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23576

   (7) https://bugs.python.org/issue?@action=redirect&bpo=23504

   (8) https://bugs.python.org/issue?@action=redirect&bpo=23563

   (9) https://bugs.python.org/issue?@action=redirect&bpo=7830

   (10) https://bugs.python.org/issue?@action=redirect&bpo=20204

   (11) https://bugs.python.org/issue?@action=redirect&bpo=19980

   (12) https://bugs.python.org/issue?@action=redirect&bpo=23521

   (13) https://bugs.python.org/issue?@action=redirect&bpo=21619

   (14) https://bugs.python.org/issue?@action=redirect&bpo=22936

   (15) https://bugs.python.org/issue?@action=redirect&bpo=15955

   (16) https://bugs.python.org/issue?@action=redirect&bpo=6639

   (17) https://bugs.python.org/issue?@action=redirect&bpo=814253

   (18) https://bugs.python.org/issue?@action=redirect&bpo=9179

   (19) https://bugs.python.org/issue?@action=redirect&bpo=23215

   (20) https://bugs.python.org/issue?@action=redirect&bpo=5700

   (21) https://bugs.python.org/issue?@action=redirect&bpo=23374

   (22) https://bugs.python.org/issue?@action=redirect&bpo=23481

   (23) https://bugs.python.org/issue?@action=redirect&bpo=21548

   (24) https://bugs.python.org/issue?@action=redirect&bpo=22885

   (25) https://bugs.python.org/issue?@action=redirect&bpo=23239

   (26) https://bugs.python.org/issue?@action=redirect&bpo=23146

   (27) https://bugs.python.org/issue?@action=redirect&bpo=23096

   (28) https://bugs.python.org/issue?@action=redirect&bpo=19105

   (29) https://bugs.python.org/issue?@action=redirect&bpo=14910

   (30) https://bugs.python.org/issue?@action=redirect&bpo=21717

   (31) https://bugs.python.org/issue?@action=redirect&bpo=23344

   (32) https://bugs.python.org/issue?@action=redirect&bpo=20416

   (33) https://bugs.python.org/issue?@action=redirect&bpo=23421

   (34) https://bugs.python.org/issue?@action=redirect&bpo=23367

   (35) https://bugs.python.org/issue?@action=redirect&bpo=23361

   (36) https://bugs.python.org/issue?@action=redirect&bpo=19705

   (37) https://bugs.python.org/issue?@action=redirect&bpo=23801


File: python.info,  Node: Build<99>,  Next: C API<78>,  Prev: Library<205>,  Up: Python 3 5 0 alpha 2

1.24.118.3 Build
................

   - bpo-23445(1): pydebug builds now use «gcc -Og» where possible, to
     make the resulting executable faster.

   - bpo-23686(2): Update OS X 10.5 installer build to use OpenSSL
     1.0.2a.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23445

   (2) https://bugs.python.org/issue?@action=redirect&bpo=23686


File: python.info,  Node: C API<78>,  Next: Windows<81>,  Prev: Build<99>,  Up: Python 3 5 0 alpha 2

1.24.118.4 C API
................

   - bpo-20204(1): Deprecation warning is now raised for builtin types
     without the __module__ attribute.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20204


File: python.info,  Node: Windows<81>,  Prev: C API<78>,  Up: Python 3 5 0 alpha 2

1.24.118.5 Windows
..................

   - bpo-23465(1): Implement PEP 486(2) - Make the Python Launcher aware
     of virtual environments.  Patch by Paul Moore.

   - bpo-23437(3): Make user scripts directory versioned on Windows.
     Patch by Paul Moore.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23465

   (2) https://peps.python.org/pep-0486/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=23437


File: python.info,  Node: Python 3 5 0 alpha 1,  Prev: Python 3 5 0 alpha 2,  Up: Changelog

1.24.119 Python 3.5.0 alpha 1
-----------------------------

'Release date: 2015-02-08'

* Menu:

* Core and Builtins: Core and Builtins<203>.
* Library: Library<206>.
* IDLE: IDLE<63>.
* Build: Build<100>.
* C API: C API<79>.
* Documentation: Documentation<84>.
* Tests: Tests<88>.
* Tools/Demos: Tools/Demos<61>.
* Windows: Windows<82>.


File: python.info,  Node: Core and Builtins<203>,  Next: Library<206>,  Up: Python 3 5 0 alpha 1

1.24.119.1 Core and Builtins
............................

   - bpo-23285(1): PEP 475 - EINTR handling.

   - bpo-22735(2): Fix many edge cases (including crashes) involving
     custom mro() implementations.

   - bpo-22896(3): Avoid using PyObject_AsCharBuffer(),
     PyObject_AsReadBuffer() and PyObject_AsWriteBuffer().

   - bpo-21295(4): Revert some changes (bpo-16795(5)) to AST line
     numbers and column offsets that constituted a regression.

   - bpo-22986(6): Allow changing an object’s __class__ between a
     dynamic type and static type in some cases.

   - bpo-15859(7): PyUnicode_EncodeFSDefault(), PyUnicode_EncodeMBCS()
     and PyUnicode_EncodeCodePage() now raise an exception if the object
     is not a Unicode object.  For PyUnicode_EncodeFSDefault(), it was
     already the case on platforms other than Windows.  Patch written by
     Campbell Barton.

   - bpo-21408(8): The default __ne__() now returns NotImplemented if
     __eq__() returned NotImplemented.  Original patch by Martin Panter.

   - bpo-23321(9): Fixed a crash in str.decode() when error handler
     returned replacement string longer than malformed input data.

   - bpo-22286(10): The «backslashreplace» error handlers now works with
     decoding and translating.

   - bpo-23253(11): Delay-load ShellExecute[AW] in os.startfile for
     reduced startup overhead on Windows.

   - bpo-22038(12): pyatomic.h now uses stdatomic.h or GCC built-in
     functions for atomic memory access if available.  Patch written by
     Vitor de Lima and Gustavo Temple.

   - bpo-20284(13): %-interpolation (aka printf) formatting added for
     bytes and bytearray.

   - bpo-23048(14): Fix jumping out of an infinite while loop in the
     pdb.

   - bpo-20335(15): bytes constructor now raises TypeError when encoding
     or errors is specified with non-string argument.  Based on patch by
     Renaud Blanch.

   - bpo-22834(16): If the current working directory ends up being set
     to a non-existent directory then import will no longer raise
     FileNotFoundError.

   - bpo-22869(17): Move the interpreter startup & shutdown code to a
     new dedicated pylifecycle.c module

   - bpo-22847(18): Improve method cache efficiency.

   - bpo-22335(19): Fix crash when trying to enlarge a bytearray to
     0x7fffffff bytes on a 32-bit platform.

   - bpo-22653(20): Fix an assertion failure in debug mode when doing a
     reentrant dict insertion in debug mode.

   - bpo-22643(21): Fix integer overflow in Unicode case operations
     (upper, lower, title, swapcase, casefold).

   - bpo-17636(22): Circular imports involving relative imports are now
     supported.

   - bpo-22604(23): Fix assertion error in debug mode when dividing a
     complex number by (nan+0j).

   - bpo-21052(24): Do not raise ImportWarning when sys.path_hooks or
     sys.meta_path are set to None.

   - bpo-16518(25): Use “bytes-like object required” in error messages
     that previously used the far more cryptic «“x” does not support the
     buffer protocol.

   - bpo-22470(26): Fixed integer overflow issues in «backslashreplace»,
     «xmlcharrefreplace», and «surrogatepass» error handlers.

   - bpo-22540(27): speed up ‘PyObject_IsInstance’ and
     ‘PyObject_IsSubclass’ in the common case that the second argument
     has metaclass ‘type’.

   - bpo-18711(28): Add a new ‘PyErr_FormatV’ function, similar to
     ‘PyErr_Format’ but accepting a ‘va_list’ argument.

   - bpo-22520(29): Fix overflow checking when generating the repr of a
     unicode object.

   - bpo-22519(30): Fix overflow checking in PyBytes_Repr.

   - bpo-22518(31): Fix integer overflow issues in latin-1 encoding.

   - bpo-16324(32): _charset parameter of MIMEText now also accepts
     email.charset.Charset instances.  Initial patch by Claude Paroz.

   - bpo-1764286(33): Fix inspect.getsource() to support decorated
     functions.  Patch by Claudiu Popa.

   - bpo-18554(34): os.__all__ includes posix functions.

   - bpo-21391(35): Use os.path.abspath in the shutil module.

   - bpo-11471(36): avoid generating a JUMP_FORWARD instruction at the
     end of an if-block if there is no else-clause.  Original patch by
     Eugene Toder.

   - bpo-22215(37): Now ValueError is raised instead of TypeError when
     str or bytes argument contains not permitted null character or
     byte.

   - bpo-22258(38): Fix the internal function set_inheritable() on
     Illumos.  This platform exposes the function ‘ioctl(FIOCLEX)’, but
     calling it fails with errno is ENOTTY: «Inappropriate ioctl for
     device».  set_inheritable() now falls back to the slower ‘fcntl()’
     (‘F_GETFD’ and then ‘F_SETFD’).

   - bpo-21389(39): Displaying the __qualname__ of the underlying
     function in the repr of a bound method.

   - bpo-22206(40): Using pthread, PyThread_create_key() now sets errno
     to ENOMEM and returns -1 (error) on integer overflow.

   - bpo-20184(41): Argument Clinic based signature introspection added
     for 30 of the builtin functions.

   - bpo-22116(42): C functions and methods (of the
     “builtin_function_or_method” type) can now be weakref’ed.  Patch by
     Wei Wu.

   - bpo-22077(43): Improve index error messages for bytearrays, bytes,
     lists, and tuples by adding “or slices”.  Added “, not <typename>”
     for bytearrays.  Original patch by Claudiu Popa.

   - bpo-20179(44): Apply Argument Clinic to bytes and bytearray.  Patch
     by Tal Einat.

   - bpo-22082(45): Clear interned strings in slotdefs.

   - Upgrade Unicode database to Unicode 7.0.0.

   - bpo-21897(46): Fix a crash with the f_locals attribute with closure
     variables when frame.clear() has been called.

   - bpo-21205(47): Add a new ‘__qualname__’ attribute to generator, the
     qualified name, and use it in the representation of a generator
     (‘repr(gen)’).  The default name of the generator (‘__name__’
     attribute) is now get from the function instead of the code.  Use
     ‘gen.gi_code.co_name’ to get the name of the code.

   - bpo-21669(48): With the aid of heuristics in SyntaxError.__init__,
     the parser now attempts to generate more meaningful (or at least
     more search engine friendly) error messages when «exec» and «print»
     are used as statements.

   - bpo-21642(49): In the conditional if-else expression, allow an
     integer written with no space between itself and the ‘else’ keyword
     (e.g.  ‘True if 42else False’) to be valid syntax.

   - bpo-21523(50): Fix over-pessimistic computation of the stack effect
     of some opcodes in the compiler.  This also fixes a quadratic
     compilation time issue noticeable when compiling code with a large
     number of «and» and «or» operators.

   - bpo-21418(51): Fix a crash in the builtin function super() when
     called without argument and without current frame (ex: embedded
     Python).

   - bpo-21425(52): Fix flushing of standard streams in the interactive
     interpreter.

   - bpo-21435(53): In rare cases, when running finalizers on objects in
     cyclic trash a bad pointer dereference could occur due to a subtle
     flaw in internal iteration logic.

   - bpo-21377(54): PyBytes_Concat() now tries to concatenate in-place
     when the first argument has a reference count of 1.  Patch by
     Nikolaus Rath.

   - bpo-20355(55): -W command line options now have higher priority
     than the PYTHONWARNINGS environment variable.  Patch by Arfrever.

   - bpo-21274(56): Define PATH_MAX for GNU/Hurd in Python/pythonrun.c.

   - bpo-20904(57): Support setting FPU precision on m68k.

   - bpo-21209(58): Fix sending tuples to custom generator objects with
     the yield from syntax.

   - bpo-21193(59): pow(a, b, c) now raises ValueError rather than
     TypeError when b is negative.  Patch by Josh Rosenberg.

   - bpo-21176(60): PEP 465: Add the “@” operator for matrix
     multiplication.

   - bpo-21134(61): Fix segfault when str is called on an uninitialized
     UnicodeEncodeError, UnicodeDecodeError, or UnicodeTranslateError
     object.

   - bpo-19537(62): Fix PyUnicode_DATA() alignment under m68k.  Patch by
     Andreas Schwab.

   - bpo-20929(63): Add a type cast to avoid shifting a negative number.

   - bpo-20731(64): Properly position in source code files even if they
     are opened in text mode.  Patch by Serhiy Storchaka.

   - bpo-20637(65): Key-sharing now also works for instance dictionaries
     of subclasses.  Patch by Peter Ingebretson.

   - bpo-8297(66): Attributes missing from modules now include the
     module name in the error text.  Original patch by ysj.ray.

   - bpo-19995(67): %c, %o, %x, and %X now raise TypeError on
     non-integer input.

   - bpo-19655(68): The ASDL parser - used by the build process to
     generate code for managing the Python AST in C - was rewritten.
     The new parser is self contained and does not require to carry long
     the spark.py parser-generator library; spark.py was removed from
     the source base.

   - bpo-12546(69): Allow ‘\x00’ to be used as a fill character when
     using str, int, float, and complex __format__ methods.

   - bpo-20480(70): Add ipaddress.reverse_pointer.  Patch by Leon Weber.

   - bpo-13598(71): Modify string.Formatter to support auto-numbering of
     replacement fields.  It now matches the behavior of str.format() in
     this regard.  Patches by Phil Elson and Ramchandra Apte.

   - bpo-8931(72): Make alternate formatting (“#”) for type “c” raise an
     exception.  In versions prior to 3.5, “#” with “c” had no effect.
     Now specifying it is an error.  Patch by Torsten Landschoff.

   - bpo-23165(73): Perform overflow checks before allocating memory in
     the _Py_char2wchar function.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23285

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22735

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22896

   (4) https://bugs.python.org/issue?@action=redirect&bpo=21295

   (5) https://bugs.python.org/issue?@action=redirect&bpo=16795

   (6) https://bugs.python.org/issue?@action=redirect&bpo=22986

   (7) https://bugs.python.org/issue?@action=redirect&bpo=15859

   (8) https://bugs.python.org/issue?@action=redirect&bpo=21408

   (9) https://bugs.python.org/issue?@action=redirect&bpo=23321

   (10) https://bugs.python.org/issue?@action=redirect&bpo=22286

   (11) https://bugs.python.org/issue?@action=redirect&bpo=23253

   (12) https://bugs.python.org/issue?@action=redirect&bpo=22038

   (13) https://bugs.python.org/issue?@action=redirect&bpo=20284

   (14) https://bugs.python.org/issue?@action=redirect&bpo=23048

   (15) https://bugs.python.org/issue?@action=redirect&bpo=20335

   (16) https://bugs.python.org/issue?@action=redirect&bpo=22834

   (17) https://bugs.python.org/issue?@action=redirect&bpo=22869

   (18) https://bugs.python.org/issue?@action=redirect&bpo=22847

   (19) https://bugs.python.org/issue?@action=redirect&bpo=22335

   (20) https://bugs.python.org/issue?@action=redirect&bpo=22653

   (21) https://bugs.python.org/issue?@action=redirect&bpo=22643

   (22) https://bugs.python.org/issue?@action=redirect&bpo=17636

   (23) https://bugs.python.org/issue?@action=redirect&bpo=22604

   (24) https://bugs.python.org/issue?@action=redirect&bpo=21052

   (25) https://bugs.python.org/issue?@action=redirect&bpo=16518

   (26) https://bugs.python.org/issue?@action=redirect&bpo=22470

   (27) https://bugs.python.org/issue?@action=redirect&bpo=22540

   (28) https://bugs.python.org/issue?@action=redirect&bpo=18711

   (29) https://bugs.python.org/issue?@action=redirect&bpo=22520

   (30) https://bugs.python.org/issue?@action=redirect&bpo=22519

   (31) https://bugs.python.org/issue?@action=redirect&bpo=22518

   (32) https://bugs.python.org/issue?@action=redirect&bpo=16324

   (33) https://bugs.python.org/issue?@action=redirect&bpo=1764286

   (34) https://bugs.python.org/issue?@action=redirect&bpo=18554

   (35) https://bugs.python.org/issue?@action=redirect&bpo=21391

   (36) https://bugs.python.org/issue?@action=redirect&bpo=11471

   (37) https://bugs.python.org/issue?@action=redirect&bpo=22215

   (38) https://bugs.python.org/issue?@action=redirect&bpo=22258

   (39) https://bugs.python.org/issue?@action=redirect&bpo=21389

   (40) https://bugs.python.org/issue?@action=redirect&bpo=22206

   (41) https://bugs.python.org/issue?@action=redirect&bpo=20184

   (42) https://bugs.python.org/issue?@action=redirect&bpo=22116

   (43) https://bugs.python.org/issue?@action=redirect&bpo=22077

   (44) https://bugs.python.org/issue?@action=redirect&bpo=20179

   (45) https://bugs.python.org/issue?@action=redirect&bpo=22082

   (46) https://bugs.python.org/issue?@action=redirect&bpo=21897

   (47) https://bugs.python.org/issue?@action=redirect&bpo=21205

   (48) https://bugs.python.org/issue?@action=redirect&bpo=21669

   (49) https://bugs.python.org/issue?@action=redirect&bpo=21642

   (50) https://bugs.python.org/issue?@action=redirect&bpo=21523

   (51) https://bugs.python.org/issue?@action=redirect&bpo=21418

   (52) https://bugs.python.org/issue?@action=redirect&bpo=21425

   (53) https://bugs.python.org/issue?@action=redirect&bpo=21435

   (54) https://bugs.python.org/issue?@action=redirect&bpo=21377

   (55) https://bugs.python.org/issue?@action=redirect&bpo=20355

   (56) https://bugs.python.org/issue?@action=redirect&bpo=21274

   (57) https://bugs.python.org/issue?@action=redirect&bpo=20904

   (58) https://bugs.python.org/issue?@action=redirect&bpo=21209

   (59) https://bugs.python.org/issue?@action=redirect&bpo=21193

   (60) https://bugs.python.org/issue?@action=redirect&bpo=21176

   (61) https://bugs.python.org/issue?@action=redirect&bpo=21134

   (62) https://bugs.python.org/issue?@action=redirect&bpo=19537

   (63) https://bugs.python.org/issue?@action=redirect&bpo=20929

   (64) https://bugs.python.org/issue?@action=redirect&bpo=20731

   (65) https://bugs.python.org/issue?@action=redirect&bpo=20637

   (66) https://bugs.python.org/issue?@action=redirect&bpo=8297

   (67) https://bugs.python.org/issue?@action=redirect&bpo=19995

   (68) https://bugs.python.org/issue?@action=redirect&bpo=19655

   (69) https://bugs.python.org/issue?@action=redirect&bpo=12546

   (70) https://bugs.python.org/issue?@action=redirect&bpo=20480

   (71) https://bugs.python.org/issue?@action=redirect&bpo=13598

   (72) https://bugs.python.org/issue?@action=redirect&bpo=8931

   (73) https://bugs.python.org/issue?@action=redirect&bpo=23165


File: python.info,  Node: Library<206>,  Next: IDLE<63>,  Prev: Core and Builtins<203>,  Up: Python 3 5 0 alpha 1

1.24.119.2 Library
..................

   - bpo-23399(1): pyvenv creates relative symlinks where possible.

   - bpo-20289(2): cgi.FieldStorage() now supports the context
     management protocol.

   - bpo-13128(3): Print response headers for CONNECT requests when
     debuglevel > 0.  Patch by Demian Brecht.

   - bpo-15381(4): Optimized io.BytesIO to make less allocations and
     copyings.

   - bpo-22818(5): Splitting on a pattern that could match an empty
     string now raises a warning.  Patterns that can only match empty
     strings are now rejected.

   - bpo-23099(6): Closing io.BytesIO with exported buffer is rejected
     now to prevent corrupting exported buffer.

   - bpo-23326(7): Removed __ne__ implementations.  Since fixing default
     __ne__ implementation in bpo-21408(8) they are redundant.

   - bpo-23363(9): Fix possible overflow in itertools.permutations.

   - bpo-23364(10): Fix possible overflow in itertools.product.

   - bpo-23366(11): Fixed possible integer overflow in
     itertools.combinations.

   - bpo-23369(12): Fixed possible integer overflow in
     _json.encode_basestring_ascii.

   - bpo-23353(13): Fix the exception handling of generators in
     PyEval_EvalFrameEx().  At entry, save or swap the exception state
     even if PyEval_EvalFrameEx() is called with throwflag=0.  At exit,
     the exception state is now always restored or swapped, not only if
     why is WHY_YIELD or WHY_RETURN. Patch co-written with Antoine
     Pitrou.

   - bpo-14099(14): Restored support of writing ZIP files to tellable
     but non-seekable streams.

   - bpo-14099(15): Writing to ZipFile and reading multiple ZipExtFiles
     is threadsafe now.

   - bpo-19361(16): JSON decoder now raises JSONDecodeError instead of
     ValueError.

   - bpo-18518(17): timeit now rejects statements which can’t be
     compiled outside a function or a loop (e.g.  «return» or «break»).

   - bpo-23094(18): Fixed readline with frames in Python implementation
     of pickle.

   - bpo-23268(19): Fixed bugs in the comparison of ipaddress classes.

   - bpo-21408(20): Removed incorrect implementations of __ne__() which
     didn’t returned NotImplemented if __eq__() returned NotImplemented.
     The default __ne__() now works correctly.

   - bpo-19996(21): ‘email.feedparser.FeedParser’ now handles
     (malformed) headers with no key rather than assuming the body has
     started.

   - bpo-20188(22): Support Application-Layer Protocol Negotiation
     (ALPN) in the ssl module.

   - bpo-23133(23): Pickling of ipaddress objects now produces more
     compact and portable representation.

   - bpo-23248(24): Update ssl error codes from latest OpenSSL git
     master.

   - bpo-23266(25): Much faster implementation of
     ipaddress.collapse_addresses() when there are many non-consecutive
     addresses.

   - bpo-23098(26): 64-bit dev_t is now supported in the os module.

   - bpo-21817(27): When an exception is raised in a task submitted to a
     ProcessPoolExecutor, the remote traceback is now displayed in the
     parent process.  Patch by Claudiu Popa.

   - bpo-15955(28): Add an option to limit output size when
     decompressing LZMA data.  Patch by Nikolaus Rath and Martin Panter.

   - bpo-23250(29): In the http.cookies module, capitalize «HttpOnly»
     and «Secure» as they are written in the standard.

   - bpo-23063(30): In the distutils” check command, fix parsing of reST
     with code or code-block directives.

   - bpo-23209(31): selectors.BaseSelector.get_key() now raises a
     RuntimeError if the selector is closed.  And
     selectors.BaseSelector.close() now clears its internal reference to
     the selector mapping to break a reference cycle.  Initial patch
     written by Martin Richard.  (See also: bpo-23225(32))

   - bpo-17911(33): Provide a way to seed the linecache for a PEP-302
     module without actually loading the code.

   - bpo-17911(34): Provide a new object API for traceback, including
     the ability to not lookup lines at all until the traceback is
     actually rendered, without any trace of the original objects being
     kept alive.

   - bpo-19777(35): Provide a home() classmethod on Path objects.
     Contributed by Victor Salgado and Mayank Tripathi.

   - bpo-23206(36): Make ‘json.dumps(..., ensure_ascii=False)’ as fast
     as the default case of ‘ensure_ascii=True’.  Patch by Naoki Inada.

   - bpo-23185(37): Add math.inf and math.nan constants.

   - bpo-23186(38): Add ssl.SSLObject.shared_ciphers() and
     ssl.SSLSocket.shared_ciphers() to fetch the client’s list ciphers
     sent at handshake.

   - bpo-23143(39): Remove compatibility with OpenSSLs older than 0.9.8.

   - bpo-23132(40): Improve performance and introspection support of
     comparison methods created by functool.total_ordering.

   - bpo-19776(41): Add an expanduser() method on Path objects.

   - bpo-23112(42): Fix SimpleHTTPServer to correctly carry the query
     string and fragment when it redirects to add a trailing slash.

   - bpo-21793(43): Added http.HTTPStatus enums (i.e.  HTTPStatus.OK,
     HTTPStatus.NOT_FOUND). Patch by Demian Brecht.

   - bpo-23093(44): In the io, module allow more operations to work on
     detached streams.

   - bpo-23111(45): In the ftplib, make ssl.PROTOCOL_SSLv23 the default
     protocol version.

   - bpo-22585(46): On OpenBSD 5.6 and newer, os.urandom() now calls
     getentropy(), instead of reading /dev/urandom, to get pseudo-random
     bytes.

   - bpo-19104(47): pprint now produces evaluable output for wrapped
     strings.

   - bpo-23071(48): Added missing names to codecs.__all__.  Patch by
     Martin Panter.

   - bpo-22783(49): Pickling now uses the NEWOBJ opcode instead of the
     NEWOBJ_EX opcode if possible.

   - bpo-15513(50): Added a __sizeof__ implementation for pickle
     classes.

   - bpo-19858(51): pickletools.optimize() now aware of the MEMOIZE
     opcode, can produce more compact result and no longer produces
     invalid output if input data contains MEMOIZE opcodes together with
     PUT or BINPUT opcodes.

   - bpo-22095(52): Fixed HTTPConnection.set_tunnel with default port.
     The port value in the host header was set to «None».  Patch by
     Demian Brecht.

   - bpo-23016(53): A warning no longer produces an AttributeError when
     the program is run with pythonw.exe.

   - bpo-21775(54): shutil.copytree(): fix crash when copying to VFAT.
     An exception handler assumed that OSError objects always have a
     “winerror” attribute.  That is not the case, so the exception
     handler itself raised AttributeError when run on Linux (and,
     presumably, any other non-Windows OS). Patch by Greg Ward.

   - bpo-1218234(55): Fix inspect.getsource() to load updated source of
     reloaded module.  Initial patch by Berker Peksag.

   - bpo-21740(56): Support wrapped callables in doctest.  Patch by
     Claudiu Popa.

   - bpo-23009(57): Make sure selectors.EpollSelector.select() works
     when no FD is registered.

   - bpo-22959(58): In the constructor of http.client.HTTPSConnection,
     prefer the context’s check_hostname attribute over the
     'check_hostname' parameter.

   - bpo-22696(59): Add function *note sys.is_finalizing(): c82. to know
     about interpreter shutdown.

   - bpo-16043(60): Add a default limit for the amount of data
     xmlrpclib.gzip_decode will return.  This resolves CVE
     2013-1753(61).

   - bpo-14099(62): ZipFile.open() no longer reopen the underlying file.
     Objects returned by ZipFile.open() can now operate independently of
     the ZipFile even if the ZipFile was created by passing in a
     file-like object as the first argument to the constructor.

   - bpo-22966(63): Fix __pycache__ pyc file name clobber when
     pyc_compile is asked to compile a source file containing multiple
     dots in the source file name.

   - bpo-21971(64): Update turtledemo doc and add module to the index.

   - bpo-21032(65): Fixed socket leak if HTTPConnection.getresponse()
     fails.  Original patch by Martin Panter.

   - bpo-22407(66): Deprecated the use of re.LOCALE flag with str
     patterns or re.ASCII. It was newer worked.

   - bpo-22902(67): The «ip» command is now used on Linux to determine
     MAC address in uuid.getnode().  Patch by Bruno Cauet.

   - bpo-22960(68): Add a context argument to xmlrpclib.ServerProxy
     constructor.

   - bpo-22389(69): Add contextlib.redirect_stderr().

   - bpo-21356(70): Make ssl.RAND_egd() optional to support LibreSSL.
     The availability of the function is checked during the compilation.
     Patch written by Bernard Spil.

   - bpo-22915(71): SAX parser now supports files opened with file
     descriptor or bytes path.

   - bpo-22609(72): Constructors and update methods of mapping classes
     in the collections module now accept the self keyword argument.

   - bpo-22940(73): Add readline.append_history_file.

   - bpo-19676(74): Added the «namereplace» error handler.

   - bpo-22788(75): Add 'context' parameter to
     logging.handlers.HTTPHandler.

   - bpo-22921(76): Allow SSLContext to take the 'hostname' parameter
     even if OpenSSL doesn’t support SNI.

   - bpo-22894(77): TestCase.subTest() would cause the test suite to be
     stopped when in failfast mode, even in the absence of failures.

   - bpo-22796(78): HTTP cookie parsing is now stricter, in order to
     protect against potential injection attacks.

   - bpo-22370(79): Windows detection in pathlib is now more robust.

   - bpo-22841(80): Reject coroutines in asyncio add_signal_handler().
     Patch by Ludovic.Gasc.

   - bpo-19494(81): Added urllib.request.HTTPBasicPriorAuthHandler.
     Patch by Matej Cepl.

   - bpo-22578(82): Added attributes to the re.error class.

   - bpo-22849(83): Fix possible double free in the io.TextIOWrapper
     constructor.

   - bpo-12728(84): Different Unicode characters having the same
     uppercase but different lowercase are now matched in
     case-insensitive regular expressions.

   - bpo-22821(85): Fixed fcntl() with integer argument on 64-bit
     big-endian platforms.

   - bpo-21650(86): Add an ‘--sort-keys’ option to ‘json.tool’ CLI.

   - bpo-22824(87): Updated reprlib output format for sets to use set
     literals.  Patch contributed by Berker Peksag.

   - bpo-22824(88): Updated reprlib output format for arrays to display
     empty arrays without an unnecessary empty list.  Suggested by
     Serhiy Storchaka.

   - bpo-22406(89): Fixed the uu_codec codec incorrectly ported to 3.x.
     Based on patch by Martin Panter.

   - bpo-17293(90): uuid.getnode() now determines MAC address on AIX
     using netstat.  Based on patch by Aivars Kalvāns.

   - bpo-22769(91): Fixed ttk.Treeview.tag_has() when called without
     arguments.

   - bpo-22417(92): Verify certificates by default in httplib (PEP 476).

   - bpo-22775(93): Fixed unpickling of http.cookies.SimpleCookie with
     protocol 2 and above.  Patch by Tim Graham.

   - bpo-22776(94): Brought excluded code into the scope of a try block
     in SysLogHandler.emit().

   - bpo-22665(95): Add missing get_terminal_size and SameFileError to
     shutil.__all__.

   - bpo-6623(96): Remove deprecated Netrc class in the ftplib module.
     Patch by Matt Chaput.

   - bpo-17381(97): Fixed handling of case-insensitive ranges in regular
     expressions.

   - bpo-22410(98): Module level functions in the re module now cache
     compiled locale-dependent regular expressions taking into account
     the locale.

   - bpo-22759(99): Query methods on pathlib.Path() (exists(), is_dir(),
     etc.)  now return False when the underlying stat call raises
     NotADirectoryError.

   - bpo-8876(100): distutils now falls back to copying files when hard
     linking doesn’t work.  This allows use with special filesystems
     such as VirtualBox shared folders.

   - bpo-22217(101): Implemented reprs of classes in the zipfile module.

   - bpo-22457(102): Honour load_tests in the start_dir of discovery.

   - bpo-18216(103): gettext now raises an error when a .mo file has an
     unsupported major version number.  Patch by Aaron Hill.

   - bpo-13918(104): Provide a locale.delocalize() function which can
     remove locale-specific number formatting from a string representing
     a number, without then converting it to a specific type.  Patch by
     Cédric Krier.

   - bpo-22676(105): Make the pickling of global objects which don’t
     have a __module__ attribute less slow.

   - bpo-18853(106): Fixed ResourceWarning in shlex.__nain__.

   - bpo-9351(107): Defaults set with set_defaults on an argparse
     subparser are no longer ignored when also set on the parent parser.

   - bpo-7559(108): unittest test loading ImportErrors are reported as
     import errors with their import exception rather than as attribute
     errors after the import has already failed.

   - bpo-19746(109): Make it possible to examine the errors from
     unittest discovery without executing the test suite.  The new
     ‘errors’ attribute on ‘TestLoader’ exposes these non-fatal errors
     encountered during discovery.

   - bpo-21991(110): Make email.headerregistry’s header “params”
     attributes be read-only (MappingProxyType).  Previously the
     dictionary was modifiable but a new one was created on each access
     of the attribute.

   - bpo-22638(111): SSLv3 is now disabled throughout the standard
     library.  It can still be enabled by instantiating a SSLContext
     manually.

   - bpo-22641(112): In asyncio, the default SSL context for client
     connections is now created using ssl.create_default_context(), for
     stronger security.

   - bpo-17401(113): Include closefd in io.FileIO repr.

   - bpo-21338(114): Add silent mode for compileall.  quiet parameters
     of compile_{dir, file, path} functions now have a multilevel value.
     Also, -q option of the CLI now have a multilevel value.  Patch by
     Thomas Kluyver.

   - bpo-20152(115): Convert the array and cmath modules to Argument
     Clinic.

   - bpo-18643(116): Add socket.socketpair() on Windows.

   - bpo-22435(117): Fix a file descriptor leak when socketserver bind
     fails.

   - bpo-13096(118): Fixed segfault in CTypes POINTER handling of large
     values.

   - bpo-11694(119): Raise ConversionError in xdrlib as documented.
     Patch by Filip Gruszczyński and Claudiu Popa.

   - bpo-19380(120): Optimized parsing of regular expressions.

   - bpo-1519638(121): Now unmatched groups are replaced with empty
     strings in re.sub() and re.subn().

   - bpo-18615(122): sndhdr.what/whathdr now return a namedtuple.

   - bpo-22462(123): Fix pyexpat’s creation of a dummy frame to make it
     appear in exception tracebacks.

   - bpo-21965(124): Add support for in-memory SSL to the ssl module.
     Patch by Geert Jansen.

   - bpo-21173(125): Fix len() on a WeakKeyDictionary when .clear() was
     called with an iterator alive.

   - bpo-11866(126): Eliminated race condition in the computation of
     names for new threads.

   - bpo-21905(127): Avoid RuntimeError in pickle.whichmodule() when
     sys.modules is mutated while iterating.  Patch by Olivier Grisel.

   - bpo-11271(128): concurrent.futures.Executor.map() now takes a
     'chunksize' argument to allow batching of tasks in child processes
     and improve performance of ProcessPoolExecutor.  Patch by Dan
     O’Reilly.

   - bpo-21883(129): os.path.join() and os.path.relpath() now raise a
     TypeError with more helpful error message for unsupported or
     mismatched types of arguments.

   - bpo-22219(130): The zipfile module CLI now adds entries for
     directories (including empty directories) in ZIP file.

   - bpo-22449(131): In the ssl.SSLContext.load_default_certs, consult
     the environmental variables SSL_CERT_DIR and SSL_CERT_FILE on
     Windows.

   - bpo-22508(132): The email.__version__ variable has been removed;
     the email code is no longer shipped separately from the stdlib, and
     __version__ hasn’t been updated in several releases.

   - bpo-20076(133): Added non derived UTF-8 aliases to locale aliases
     table.

   - bpo-20079(134): Added locales supported in glibc 2.18 to locale
     alias table.

   - bpo-20218(135): Added convenience methods read_text/write_text and
     read_bytes/ write_bytes to pathlib.Path objects.

   - bpo-22396(136): On 32-bit AIX platform, don’t expose
     os.posix_fadvise() nor os.posix_fallocate() because their
     prototypes in system headers are wrong.

   - bpo-22517(137): When an io.BufferedRWPair object is deallocated,
     clear its weakrefs.

   - bpo-22437(138): Number of capturing groups in regular expression is
     no longer limited by 100.

   - bpo-17442(139): InteractiveInterpreter now displays the full
     chained traceback in its showtraceback method, to match the built
     in interactive interpreter.

   - bpo-23392(140): Added tests for marshal C API that works with
     FILE*.

   - bpo-10510(141): distutils register and upload methods now use HTML
     standards compliant CRLF line endings.

   - bpo-9850(142): Fixed macpath.join() for empty first component.
     Patch by Oleg Oshmyan.

   - bpo-5309(143): distutils” build and build_ext commands now accept a
     ‘-j’ option to enable parallel building of extension modules.

   - bpo-22448(144): Improve canceled timer handles cleanup to prevent
     unbound memory usage.  Patch by Joshua Moore-Oliva.

   - bpo-22427(145): TemporaryDirectory no longer attempts to clean up
     twice when used in the with statement in generator.

   - bpo-22362(146): Forbidden ambiguous octal escapes out of range
     0-0o377 in regular expressions.

   - bpo-20912(147): Now directories added to ZIP file have correct Unix
     and MS-DOS directory attributes.

   - bpo-21866(148): ZipFile.close() no longer writes ZIP64 central
     directory records if allowZip64 is false.

   - bpo-22278(149): Fix urljoin problem with relative urls, a
     regression observed after changes to issue22118 were submitted.

   - bpo-22415(150): Fixed debugging output of the GROUPREF_EXISTS
     opcode in the re module.  Removed trailing spaces in debugging
     output.

   - bpo-22423(151): Unhandled exception in thread no longer causes
     unhandled AttributeError when sys.stderr is None.

   - bpo-21332(152): Ensure that ‘bufsize=1’ in subprocess.Popen()
     selects line buffering, rather than block buffering.  Patch by
     Akira Li.

   - bpo-21091(153): Fix API bug:
     email.message.EmailMessage.is_attachment is now a method.

   - bpo-21079(154): Fix email.message.EmailMessage.is_attachment to
     return the correct result when the header has parameters as well as
     a value.

   - bpo-22247(155): Add NNTPError to nntplib.__all__.

   - bpo-22366(156): urllib.request.urlopen will accept a context object
     (SSLContext) as an argument which will then be used for HTTPS
     connection.  Patch by Alex Gaynor.

   - bpo-4180(157): The warnings registries are now reset when the
     filters are modified.

   - bpo-22419(158): Limit the length of incoming HTTP request in
     wsgiref server to 65536 bytes and send a 414 error code for higher
     lengths.  Patch contributed by Devin Cook.

   - Lax cookie parsing in http.cookies could be a security issue when
     combined with non-standard cookie handling in some web browsers.
     Reported by Sergey Bobrov.

   - bpo-20537(159): logging methods now accept an exception instance as
     well as a Boolean value or exception tuple.  Thanks to Yury
     Selivanov for the patch.

   - bpo-22384(160): An exception in Tkinter callback no longer crashes
     the program when it is run with pythonw.exe.

   - bpo-22168(161): Prevent turtle AttributeError with non-default
     Canvas on OS X.

   - bpo-21147(162): sqlite3 now raises an exception if the request
     contains a null character instead of truncating it.  Based on patch
     by Victor Stinner.

   - bpo-13968(163): The glob module now supports recursive search in
     subdirectories using the ‘**’ pattern.

   - bpo-21951(164): Fixed a crash in Tkinter on AIX when called Tcl
     command with empty string or tuple argument.

   - bpo-21951(165): Tkinter now most likely raises MemoryError instead
     of crash if the memory allocation fails.

   - bpo-22338(166): Fix a crash in the json module on memory allocation
     failure.

   - bpo-12410(167): imaplib.IMAP4 now supports the context management
     protocol.  Original patch by Tarek Ziadé.

   - bpo-21270(168): We now override tuple methods in mock.call objects
     so that they can be used as normal call attributes.

   - bpo-16662(169): ‘load_tests()’ is now unconditionally run when it
     is present in a package’s ‘__init__.py’.
     ‘TestLoader.loadTestsFromModule()’ still accepts use_load_tests,
     but it is deprecated and ignored.  A new keyword-only attribute
     ‘pattern’ is added and documented.  Patch given by Robert Collins,
     tweaked by Barry Warsaw.

   - bpo-22226(170): First letter no longer is stripped from the
     «status» key in the result of Treeview.heading().

   - bpo-19524(171): Fixed resource leak in the HTTP connection when an
     invalid response is received.  Patch by Martin Panter.

   - bpo-20421(172): Add a .version() method to SSL sockets exposing the
     actual protocol version in use.

   - bpo-19546(173): configparser exceptions no longer expose
     implementation details.  Chained KeyErrors are removed, which leads
     to cleaner tracebacks.  Patch by Claudiu Popa.

   - bpo-22051(174): turtledemo no longer reloads examples to re-run
     them.  Initialization of variables and gui setup should be done in
     main(), which is called each time a demo is run, but not on import.

   - bpo-21933(175): Turtledemo users can change the code font size with
     a menu selection or control(command) “-” or “+” or
     control-mousewheel.  Original patch by Lita Cho.

   - bpo-21597(176): The separator between the turtledemo text pane and
     the drawing canvas can now be grabbed and dragged with a mouse.
     The code text pane can be widened to easily view or copy the full
     width of the text.  The canvas can be widened on small screens.
     Original patches by Jan Kanis and Lita Cho.

   - bpo-18132(177): Turtledemo buttons no longer disappear when the
     window is shrunk.  Original patches by Jan Kanis and Lita Cho.

   - bpo-22043(178): time.monotonic() is now always available.
     ‘threading.Lock.acquire()’, ‘threading.RLock.acquire()’ and socket
     operations now use a monotonic clock, instead of the system clock,
     when a timeout is used.

   - bpo-21527(179): Add a default number of workers to
     ThreadPoolExecutor equal to 5 times the number of CPUs.  Patch by
     Claudiu Popa.

   - bpo-22216(180): smtplib now resets its state more completely after
     a quit.  The most obvious consequence of the previous behavior was
     a STARTTLS failure during a connect/starttls/quit/connect/starttls
     sequence.

   - bpo-22098(181): ctypes” BigEndianStructure and
     LittleEndianStructure now define an empty __slots__ so that
     subclasses don’t always get an instance dict.  Patch by Claudiu
     Popa.

   - bpo-22185(182): Fix an occasional RuntimeError in
     threading.Condition.wait() caused by mutation of the waiters queue
     without holding the lock.  Patch by Doug Zongker.

   - bpo-22287(183): On UNIX, _PyTime_gettimeofday() now uses
     clock_gettime(CLOCK_REALTIME) if available.  As a side effect,
     Python now depends on the librt library on Solaris and on Linux
     (only with glibc older than 2.17).

   - bpo-22182(184): Use e.args to unpack exceptions correctly in
     distutils.file_util.move_file.  Patch by Claudiu Popa.

   - The webbrowser module now uses subprocess’s start_new_session=True
     rather than a potentially risky preexec_fn=os.setsid call.

   - bpo-22042(185): signal.set_wakeup_fd(fd) now raises an exception if
     the file descriptor is in blocking mode.

   - bpo-16808(186): inspect.stack() now returns a named tuple instead
     of a tuple.  Patch by Daniel Shahaf.

   - bpo-22236(187): Fixed Tkinter images copying operations in
     NoDefaultRoot mode.

   - bpo-2527(188): Add a 'globals' argument to timeit functions, in
     order to override the globals namespace in which the timed code is
     executed.  Patch by Ben Roberts.

   - bpo-22118(189): Switch urllib.parse to use RFC 3986 semantics for
     the resolution of relative URLs, rather than RFCs 1808 and 2396.
     Patch by Demian Brecht.

   - bpo-21549(190): Added the «members» parameter to TarFile.list().

   - bpo-19628(191): Allow compileall recursion depth to be specified
     with a -r option.

   - bpo-15696(192): Add a __sizeof__ implementation for mmap objects on
     Windows.

   - bpo-22068(193): Avoided reference loops with Variables and Fonts in
     Tkinter.

   - bpo-22165(194): SimpleHTTPRequestHandler now supports undecodable
     file names.

   - bpo-15381(195): Optimized line reading in io.BytesIO.

   - bpo-8797(196): Raise HTTPError on failed Basic Authentication
     immediately.  Initial patch by Sam Bull.

   - bpo-20729(197): Restored the use of lazy
     iterkeys()/itervalues()/iteritems() in the mailbox module.

   - bpo-21448(198): Changed FeedParser feed() to avoid 'O'('n'^2)
     behavior when parsing long line.  Original patch by Raymond
     Hettinger.

   - bpo-22184(199): The functools LRU Cache decorator factory now gives
     an earlier and clearer error message when the user forgets the
     required parameters.

   - bpo-17923(200): glob() patterns ending with a slash no longer match
     non-dirs on AIX. Based on patch by Delhallt.

   - bpo-21725(201): Added support for RFC 6531 (SMTPUTF8) in smtpd.

   - bpo-22176(202): Update the ctypes module’s libffi to v3.1.  This
     release adds support for the Linux AArch64 and POWERPC ELF ABIv2
     little endian architectures.

   - bpo-5411(203): Added support for the «xztar» format in the shutil
     module.

   - bpo-21121(204): Don’t force 3rd party C extensions to be built with
     -Werror=declaration-after-statement.

   - bpo-21975(205): Fixed crash when using uninitialized sqlite3.Row
     (in particular when unpickling pickled sqlite3.Row).  sqlite3.Row
     is now initialized in the __new__() method.

   - bpo-20170(206): Convert posixmodule to use Argument Clinic.

   - bpo-21539(207): Add an 'exists_ok' argument to ‘Pathlib.mkdir()’ to
     mimic ‘mkdir -p’ and ‘os.makedirs()’ functionality.  When true,
     ignore ‘FileExistsErrors’.  Patch by Berker Peksag.

   - bpo-22127(208): Bypass IDNA for pure-ASCII host names in the socket
     module (in particular for numeric IPs).

   - bpo-21047(209): set the default value for the 'convert_charrefs'
     argument of HTMLParser to True.  Patch by Berker Peksag.

   - Add an __all__ to html.entities.

   - bpo-15114(210): the strict mode and argument of HTMLParser,
     HTMLParser.error, and the HTMLParserError exception have been
     removed.

   - bpo-22085(211): Dropped support of Tk 8.3 in Tkinter.

   - bpo-21580(212): Now Tkinter correctly handles bytes arguments
     passed to Tk.  In particular this allows initializing images from
     binary data.

   - bpo-22003(213): When initialized from a bytes object, io.BytesIO()
     now defers making a copy until it is mutated, improving performance
     and memory use on some use cases.  Patch by David Wilson.

   - bpo-22018(214): On Windows, signal.set_wakeup_fd() now also
     supports sockets.  A side effect is that Python depends to the
     WinSock library.

   - bpo-22054(215): Add os.get_blocking() and os.set_blocking()
     functions to get and set the blocking mode of a file descriptor
     (False if the O_NONBLOCK flag is set, True otherwise).  These
     functions are not available on Windows.

   - bpo-17172(216): Make turtledemo start as active on OS X even when
     run with subprocess.  Patch by Lita Cho.

   - bpo-21704(217): Fix build error for _multiprocessing when
     semaphores are not available.  Patch by Arfrever Frehtes Taifersar
     Arahesis.

   - bpo-20173(218): Convert sha1, sha256, sha512 and md5 to
     ArgumentClinic.  Patch by Vajrasky Kok.

   - Fix repr(_socket.socket) on Windows 64-bit: don’t fail with
     OverflowError on closed socket.  repr(socket.socket) already works
     fine.

   - bpo-22033(219): Reprs of most Python implemented classes now
     contain actual class name instead of hardcoded one.

   - bpo-21947(220): The dis module can now disassemble
     generator-iterator objects based on their gi_code attribute.  Patch
     by Clement Rouault.

   - bpo-16133(221): The asynchat.async_chat.handle_read() method now
     ignores BlockingIOError exceptions.

   - bpo-22044(222): Fixed premature DECREF in call_tzinfo_method.
     Patch by Tom Flanagan.

   - bpo-19884(223): readline: Disable the meta modifier key if stdout
     is not a terminal to not write the ANSI sequence ‘"\033[1034h"’
     into stdout.  This sequence is used on some terminal (ex:
     TERM=xterm-256color») to enable support of 8 bit characters.

   - bpo-4350(224): Removed a number of out-of-dated and non-working for
     a long time Tkinter methods.

   - bpo-6167(225): Scrollbar.activate() now returns the name of active
     element if the argument is not specified.  Scrollbar.set() now
     always accepts only 2 arguments.

   - bpo-15275(226): Clean up and speed up the ntpath module.

   - bpo-21888(227): plistlib’s load() and loads() now work if the fmt
     parameter is specified.

   - bpo-22032(228): __qualname__ instead of __name__ is now always used
     to format fully qualified class names of Python implemented
     classes.

   - bpo-22031(229): Reprs now always use hexadecimal format with the
     «0x» prefix when contain an id in form « at 0x…».

   - bpo-22018(230): signal.set_wakeup_fd() now raises an OSError
     instead of a ValueError on ‘fstat()’ failure.

   - bpo-21044(231): tarfile.open() now handles fileobj with an integer
     “name” attribute.  Based on patch by Antoine Pietri.

   - bpo-21966(232): Respect -q command-line option when code module is
     ran.

   - bpo-19076(233): Don’t pass the redundant “file” argument to
     self.error().

   - bpo-16382(234): Improve exception message of warnings.warn() for
     bad category.  Initial patch by Phil Elson.

   - bpo-21932(235): os.read() now uses a *note Py_ssize_t(): c57. type
     instead of int for the size to support reading more than 2 GB at
     once.  On Windows, the size is truncated to INT_MAX. As any call to
     os.read(), the OS may read less bytes than the number of requested
     bytes.

   - bpo-21942(236): Fixed source file viewing in pydoc’s server mode on
     Windows.

   - bpo-11259(237): asynchat.async_chat().set_terminator() now raises a
     ValueError if the number of received bytes is negative.

   - bpo-12523(238): asynchat.async_chat.push() now raises a TypeError
     if it doesn’t get a bytes string

   - bpo-21707(239): Add missing kwonlyargcount argument to
     ModuleFinder.replace_paths_in_code().

   - bpo-20639(240): calling Path.with_suffix(“”) allows removing the
     suffix again.  Patch by July Tikhonov.

   - bpo-21714(241): Disallow the construction of invalid paths using
     Path.with_name().  Original patch by Antony Lee.

   - bpo-15014(242): Added “auth” method to smtplib to make implementing
     auth mechanisms simpler, and used it internally in the login
     method.

   - bpo-21151(243): Fixed a segfault in the winreg module when ‘None’
     is passed as a ‘REG_BINARY’ value to SetValueEx.  Patch by John
     Ehresman.

   - bpo-21090(244): io.FileIO.readall() does not ignore I/O errors
     anymore.  Before, it ignored I/O errors if at least the first C
     call read() succeed.

   - bpo-5800(245): headers parameter of wsgiref.headers.Headers is now
     optional.  Initial patch by Pablo Torres Navarrete and SilentGhost.

   - bpo-21781(246): ssl.RAND_add() now supports strings longer than 2
     GB.

   - bpo-21679(247): Prevent extraneous fstat() calls during open().
     Patch by Bohuslav Kabrda.

   - bpo-21863(248): cProfile now displays the module name of C
     extension functions, in addition to their own name.

   - bpo-11453(249): asyncore: emit a ResourceWarning when an unclosed
     file_wrapper object is destroyed.  The destructor now closes the
     file if needed.  The close() method can now be called twice: the
     second call does nothing.

   - bpo-21858(250): Better handling of Python exceptions in the sqlite3
     module.

   - bpo-21476(251): Make sure the email.parser.BytesParser
     TextIOWrapper is discarded after parsing, so the input file isn’t
     unexpectedly closed.

   - bpo-20295(252): imghdr now recognizes OpenEXR format images.

   - bpo-21729(253): Used the «with» statement in the dbm.dumb module to
     ensure files closing.  Patch by Claudiu Popa.

   - bpo-21491(254): socketserver: Fix a race condition in child
     processes reaping.

   - bpo-21719(255): Added the ‘st_file_attributes’ field to
     os.stat_result on Windows.

   - bpo-21832(256): Require named tuple inputs to be exact strings.

   - bpo-21722(257): The distutils «upload» command now exits with a
     non-zero return code when uploading fails.  Patch by Martin
     Dengler.

   - bpo-21723(258): asyncio.Queue: support any type of number (ex:
     float) for the maximum size.  Patch written by Vajrasky Kok.

   - bpo-21711(259): support for «site-python» directories has now been
     removed from the site module (it was deprecated in 3.4).

   - bpo-17552(260): new socket.sendfile() method allowing a file to be
     sent over a socket by using high-performance os.sendfile() on UNIX.
     Patch by Giampaolo Rodola”.

   - bpo-18039(261): dbm.dump.open() now always creates a new database
     when the flag has the value “n”.  Patch by Claudiu Popa.

   - bpo-21326(262): Add a new is_closed() method to
     asyncio.BaseEventLoop.  run_forever() and run_until_complete()
     methods of asyncio.BaseEventLoop now raise an exception if the
     event loop was closed.

   - bpo-21766(263): Prevent a security hole in CGIHTTPServer by URL
     unquoting paths before checking for a CGI script at that path.

   - bpo-21310(264): Fixed possible resource leak in failed open().

   - bpo-21256(265): Printout of keyword args should be in deterministic
     order in a mock function call.  This will help to write better
     doctests.

   - bpo-21677(266): Fixed chaining nonnormalized exceptions in io
     close() methods.

   - bpo-11709(267): Fix the pydoc.help function to not fail when
     sys.stdin is not a valid file.

   - bpo-21515(268): tempfile.TemporaryFile now uses os.O_TMPFILE flag
     is available.

   - bpo-13223(269): Fix pydoc.writedoc so that the HTML documentation
     for methods that use “self” in the example code is generated
     correctly.

   - bpo-21463(270): In urllib.request, fix pruning of the FTP cache.

   - bpo-21618(271): The subprocess module could fail to close open fds
     that were inherited by the calling process and already higher than
     POSIX resource limits would otherwise allow.  On systems with a
     functioning /proc/self/fd or /dev/fd interface the max is now
     ignored and all fds are closed.

   - bpo-20383(272): Introduce importlib.util.module_from_spec() as the
     preferred way to create a new module.

   - bpo-21552(273): Fixed possible integer overflow of too long string
     lengths in the tkinter module on 64-bit platforms.

   - bpo-14315(274): The zipfile module now ignores extra fields in the
     central directory that are too short to be parsed instead of
     letting a struct.unpack error bubble up as this «bad data» appears
     in many real world zip files in the wild and is ignored by other
     zip tools.

   - bpo-13742(275): Added «key» and «reverse» parameters to
     heapq.merge().  (First draft of patch contributed by Simon Sapin.)

   - bpo-21402(276): tkinter.ttk now works when default root window is
     not set.

   - bpo-3015(277): ‘_tkinter.create()’ now creates ‘tkapp’ object with
     ‘wantobjects=1’ by default.

   - bpo-10203(278): sqlite3.Row now truly supports sequence protocol.
     In particular it supports reverse() and negative indices.  Original
     patch by Claudiu Popa.

   - bpo-18807(279): If copying (no symlinks) specified for a venv, then
     the python interpreter aliases (python, python3) are now created by
     copying rather than symlinking.

   - bpo-20197(280): Added support for the WebP image type in the imghdr
     module.  Patch by Fabrice Aneche and Claudiu Popa.

   - bpo-21513(281): Speedup some properties of IP addresses
     (IPv4Address, IPv6Address) such as .is_private or .is_multicast.

   - bpo-21137(282): Improve the repr for threading.Lock() and its
     variants by showing the «locked» or «unlocked» status.  Patch by
     Berker Peksag.

   - bpo-21538(283): The plistlib module now supports loading of binary
     plist files when reference or offset size is not a power of two.

   - bpo-21455(284): Add a default backlog to socket.listen().

   - bpo-21525(285): Most Tkinter methods which accepted tuples now
     accept lists too.

   - bpo-22166(286): With the assistance of a new internal
     _codecs._forget_codec helping function, test_codecs now clears the
     encoding caches to avoid the appearance of a reference leak

   - bpo-22236(287): Tkinter tests now don’t reuse default root window.
     New root window is created for every test class.

   - bpo-10744(288): Fix PEP 3118(289) format strings on ctypes objects
     with a nontrivial shape.

   - bpo-20826(290): Optimize ipaddress.collapse_addresses().

   - bpo-21487(291): Optimize ipaddress.summarize_address_range() and
     ipaddress.{IPv4Network,IPv6Network}.subnets().

   - bpo-21486(292): Optimize parsing of netmasks in
     ipaddress.IPv4Network and ipaddress.IPv6Network.

   - bpo-13916(293): Disallowed the surrogatepass error handler for non
     UTF-* encodings.

   - bpo-20998(294): Fixed re.fullmatch() of repeated single character
     pattern with ignore case.  Original patch by Matthew Barnett.

   - bpo-21075(295): fileinput.FileInput now reads bytes from standard
     stream if binary mode is specified.  Patch by Sam Kimbrel.

   - bpo-19775(296): Add a samefile() method to pathlib Path objects.
     Initial patch by Vajrasky Kok.

   - bpo-21226(297): Set up modules properly in
     PyImport_ExecCodeModuleObject (and friends).

   - bpo-21398(298): Fix a unicode error in the pydoc pager when the
     documentation contains characters not encodable to the stdout
     encoding.

   - bpo-16531(299): ipaddress.IPv4Network and ipaddress.IPv6Network now
     accept an (address, netmask) tuple argument, so as to easily
     construct network objects from existing addresses.

   - bpo-21156(300): importlib.abc.InspectLoader.source_to_code() is now
     a staticmethod.

   - bpo-21424(301): Simplified and optimized heaqp.nlargest() and
     nmsmallest() to make fewer tuple comparisons.

   - bpo-21396(302): Fix TextIOWrapper(…, write_through=True) to not
     force a flush() on the underlying binary stream.  Patch by akira.

   - bpo-18314(303): Unlink now removes junctions on Windows.  Patch by
     Kim Gräsman

   - bpo-21088(304): Bugfix for curses.window.addch() regression in
     3.4.0.  In porting to Argument Clinic, the first two arguments were
     reversed.

   - bpo-21407(305): _decimal: The module now supports function
     signatures.

   - bpo-10650(306): Remove the non-standard “watchexp” parameter from
     the Decimal.quantize() method in the Python version.  It had never
     been present in the C version.

   - bpo-21469(307): Reduced the risk of false positives in robotparser
     by checking to make sure that robots.txt has been read or does not
     exist prior to returning True in can_fetch().

   - bpo-19414(308): Have the OrderedDict mark deleted links as
     unusable.  This gives an early failure if the link is deleted
     during iteration.

   - bpo-21421(309): Add __slots__ to the MappingViews ABC. Patch by
     Josh Rosenberg.

   - bpo-21101(310): Eliminate double hashing in the C speed-up code for
     collections.Counter().

   - bpo-21321(311): itertools.islice() now releases the reference to
     the source iterator when the slice is exhausted.  Patch by Anton
     Afanasyev.

   - bpo-21057(312): TextIOWrapper now allows the underlying binary
     stream’s read() or read1() method to return an arbitrary bytes-like
     object (such as a memoryview).  Patch by Nikolaus Rath.

   - bpo-20951(313): SSLSocket.send() now raises either SSLWantReadError
     or SSLWantWriteError on a non-blocking socket if the operation
     would block.  Previously, it would return 0.  Patch by Nikolaus
     Rath.

   - bpo-13248(314): removed previously deprecated asyncore.dispatcher
     __getattr__ cheap inheritance hack.

   - bpo-9815(315): assertRaises now tries to clear references to local
     variables in the exception’s traceback.

   - bpo-19940(316): ssl.cert_time_to_seconds() now interprets the given
     time string in the UTC timezone (as specified in RFC 5280), not the
     local timezone.

   - bpo-13204(317): Calling sys.flags.__new__ would crash the
     interpreter, now it raises a TypeError.

   - bpo-19385(318): Make operations on a closed dbm.dumb database
     always raise the same exception.

   - bpo-21207(319): Detect when the os.urandom cached fd has been
     closed or replaced, and open it anew.

   - bpo-21291(320): subprocess’s Popen.wait() is now thread safe so
     that multiple threads may be calling wait() or poll() on a Popen
     instance at the same time without losing the Popen.returncode
     value.

   - bpo-21127(321): Path objects can now be instantiated from str
     subclass instances (such as ‘numpy.str_’).

   - bpo-15002(322): urllib.response object to use _TemporaryFileWrapper
     (and _TemporaryFileCloser) facility.  Provides a better way to
     handle file descriptor close.  Patch contributed by Christian
     Theune.

   - bpo-12220(323): mindom now raises a custom ValueError indicating it
     doesn’t support spaces in URIs instead of letting a “split”
     ValueError bubble up.

   - bpo-21068(324): The ssl.PROTOCOL* constants are now enum members.

   - bpo-21276(325): posixmodule: Don’t define USE_XATTRS on KFreeBSD
     and the Hurd.

   - bpo-21262(326): New method assert_not_called for Mock.  It raises
     AssertionError if the mock has been called.

   - bpo-21238(327): New keyword argument ‘unsafe’ to Mock.  It raises
     ‘AttributeError’ in case of an attribute startswith assert or
     assret.

   - bpo-20896(328): ssl.get_server_certificate() now uses
     PROTOCOL_SSLv23, not PROTOCOL_SSLv3, for maximum compatibility.

   - bpo-21239(329): patch.stopall() didn’t work deterministically when
     the same name was patched more than once.

   - bpo-21203(330): Updated fileConfig and dictConfig to remove
     inconsistencies.  Thanks to Jure Koren for the patch.

   - bpo-21222(331): Passing name keyword argument to
     mock.create_autospec now works.

   - bpo-21197(332): Add lib64 -> lib symlink in venvs on 64-bit non-OS
     X POSIX.

   - bpo-17498(333): Some SMTP servers disconnect after certain errors,
     violating strict RFC conformance.  Instead of losing the error code
     when we issue the subsequent RSET, smtplib now returns the error
     code and defers raising the SMTPServerDisconnected error until the
     next command is issued.

   - bpo-17826(334): setting an iterable side_effect on a mock function
     created by create_autospec now works.  Patch by Kushal Das.

   - bpo-7776(335): Fix ‘Host:’ header and reconnection when using
     http.client.HTTPConnection.set_tunnel().  Patch by Nikolaus Rath.

   - bpo-20968(336): unittest.mock.MagicMock now supports division.
     Patch by Johannes Baiter.

   - bpo-21529(337): Fix arbitrary memory access in
     JSONDecoder.raw_decode with a negative second parameter.  Bug
     reported by Guido Vranken.  (See also: CVE 2014-4616(338))

   - bpo-21169(339): getpass now handles non-ascii characters that the
     input stream encoding cannot encode by re-encoding using the
     replace error handler.

   - bpo-21171(340): Fixed undocumented filter API of the rot13 codec.
     Patch by Berker Peksag.

   - bpo-20539(341): Improved math.factorial error message for large
     positive inputs and changed exception type (OverflowError ->
     ValueError) for large negative inputs.

   - bpo-21172(342): isinstance check relaxed from dict to
     collections.Mapping.

   - bpo-21155(343): asyncio.EventLoop.create_unix_server() now raises a
     ValueError if path and sock are specified at the same time.

   - bpo-21136(344): Avoid unnecessary normalization of Fractions
     resulting from power and other operations.  Patch by Raymond
     Hettinger.

   - bpo-17621(345): Introduce importlib.util.LazyLoader.

   - bpo-21076(346): signal module constants were turned into enums.
     Patch by Giampaolo Rodola”.

   - bpo-20636(347): Improved the repr of Tkinter widgets.

   - bpo-19505(348): The items, keys, and values views of OrderedDict
     now support reverse iteration using reversed().

   - bpo-21149(349): Improved thread-safety in logging cleanup during
     interpreter shutdown.  Thanks to Devin Jeanpierre for the patch.

   - bpo-21058(350): Fix a leak of file descriptor in *note
     tempfile.NamedTemporaryFile(): 6ee, close the file descriptor if
     *note io.open(): 741. fails

   - bpo-21200(351): Return None from pkgutil.get_loader() when __spec__
     is missing.

   - bpo-21013(352): Enhance ssl.create_default_context() when used for
     server side sockets to provide better security by default.

   - bpo-20145(353): ‘assertRaisesRegex’ and ‘assertWarnsRegex’ now
     raise a ‘TypeError’ if the second argument is not a string or
     compiled regex.

   - bpo-20633(354): Replace relative import by absolute import.

   - bpo-20980(355): Stop wrapping exception when using ThreadPool.

   - bpo-21082(356): In os.makedirs, do not set the process-wide umask.
     Note this changes behavior of makedirs when exist_ok=True.

   - bpo-20990(357): Fix issues found by pyflakes for multiprocessing.

   - bpo-21015(358): SSL contexts will now automatically select an
     elliptic curve for ECDH key exchange on OpenSSL 1.0.2 and later,
     and otherwise default to «prime256v1».

   - bpo-21000(359): Improve the command-line interface of json.tool.

   - bpo-20995(360): Enhance default ciphers used by the ssl module to
     enable better security and prioritize perfect forward secrecy.

   - bpo-20884(361): Don’t assume that __file__ is defined on
     importlib.__init__.

   - bpo-21499(362): Ignore __builtins__ in several
     test_importlib.test_api tests.

   - bpo-20627(363): xmlrpc.client.ServerProxy is now a context manager.

   - bpo-19165(364): The formatter module now raises DeprecationWarning
     instead of PendingDeprecationWarning.

   - bpo-13936(365): Remove the ability of datetime.time instances to be
     considered false in boolean contexts.

   - bpo-18931(366): selectors module now supports /dev/poll on Solaris.
     Patch by Giampaolo Rodola”.

   - bpo-19977(367): When the ‘LC_TYPE’ locale is the POSIX locale (‘C’
     locale), *note sys.stdin: 760. and *note sys.stdout: ccf. are now
     using the ‘surrogateescape’ error handler, instead of the ‘strict’
     error handler.

   - bpo-20574(368): Implement incremental decoder for cp65001 code
     (Windows code page 65001, Microsoft UTF-8).

   - bpo-20879(369): Delay the initialization of encoding and decoding
     tables for base32, ascii85 and base85 codecs in the base64 module,
     and delay the initialization of the unquote_to_bytes() table of the
     urllib.parse module, to not waste memory if these modules are not
     used.

   - bpo-19157(370): Include the broadcast address in the usable hosts
     for IPv6 in ipaddress.

   - bpo-11599(371): When an external command (e.g.  compiler) fails,
     distutils now prints out the whole command line (instead of just
     the command name) if the environment variable DISTUTILS_DEBUG is
     set.

   - bpo-4931(372): distutils should not produce unhelpful «error: None»
     messages anymore.  distutils.util.grok_environment_error is kept
     but doc-deprecated.

   - bpo-20875(373): Prevent possible gzip «“read” is not defined»
     NameError.  Patch by Claudiu Popa.

   - bpo-11558(374): ‘email.message.Message.attach’ now returns a more
     useful error message if ‘attach’ is called on a message for which
     ‘is_multipart’ is False.

   - bpo-20283(375): RE pattern methods now accept the string keyword
     parameters as documented.  The pattern and source keyword
     parameters are left as deprecated aliases.

   - bpo-20778(376): Fix modulefinder to work with bytecode-only
     modules.

   - bpo-20791(377): copy.copy() now doesn’t make a copy when the input
     is a bytes object.  Initial patch by Peter Otten.

   - bpo-19748(378): On AIX, time.mktime() now raises an OverflowError
     for year outsize range [1902; 2037].

   - bpo-19573(379): inspect.signature: Use enum for parameter kind
     constants.

   - bpo-20726(380): inspect.signature: Make Signature and Parameter
     picklable.

   - bpo-17373(381): Add inspect.Signature.from_callable method.

   - bpo-20378(382): Improve repr of inspect.Signature and
     inspect.Parameter.

   - bpo-20816(383): Fix inspect.getcallargs() to raise correct
     TypeError for missing keyword-only arguments.  Patch by Jeremiah
     Lowin.

   - bpo-20817(384): Fix inspect.getcallargs() to fail correctly if more
     than 3 arguments are missing.  Patch by Jeremiah Lowin.

   - bpo-6676(385): Ensure a meaningful exception is raised when
     attempting to parse more than one XML document per pyexpat
     xmlparser instance.  (Original patches by Hirokazu Yamamoto and
     Amaury Forgeot d’Arc, with suggested wording by David Gutteridge)

   - bpo-21117(386): Fix inspect.signature to better support
     functools.partial.  Due to the specifics of functools.partial
     implementation, positional-or-keyword arguments passed as keyword
     arguments become keyword-only.

   - bpo-20334(387): inspect.Signature and inspect.Parameter are now
     hashable.  Thanks to Antony Lee for bug reports and suggestions.

   - bpo-15916(388): doctest.DocTestSuite returns an empty
     unittest.TestSuite instead of raising ValueError if it finds no
     tests

   - bpo-21209(389): Fix asyncio.tasks.CoroWrapper to workaround a bug
     in yield-from implementation in CPythons prior to 3.4.1.

   - asyncio: Add gi_{frame,running,code} properties to CoroWrapper
     (upstream bpo-163(390)).

   - bpo-21311(391): Avoid exception in _osx_support with non-standard
     compiler configurations.  Patch by John Szakmeister.

   - bpo-11571(392): Ensure that the turtle window becomes the topmost
     window when launched on OS X.

   - bpo-21801(393): Validate that __signature__ is None or an instance
     of Signature.

   - bpo-21923(394): Prevent AttributeError in
     distutils.sysconfig.customize_compiler due to possible
     uninitialized _config_vars.

   - bpo-21323(395): Fix http.server to again handle scripts in CGI
     subdirectories, broken by the fix for security bpo-19435(396).
     Patch by Zach Byrne.

   - bpo-22733(397): Fix ffi_prep_args not zero-extending argument
     values correctly on 64-bit Windows.

   - bpo-23302(398): Default to TCP_NODELAY=1 upon establishing an
     HTTPConnection.  Removed use of hard-coded MSS as it’s an
     optimization that’s no longer needed with Nagle disabled.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23399

   (2) https://bugs.python.org/issue?@action=redirect&bpo=20289

   (3) https://bugs.python.org/issue?@action=redirect&bpo=13128

   (4) https://bugs.python.org/issue?@action=redirect&bpo=15381

   (5) https://bugs.python.org/issue?@action=redirect&bpo=22818

   (6) https://bugs.python.org/issue?@action=redirect&bpo=23099

   (7) https://bugs.python.org/issue?@action=redirect&bpo=23326

   (8) https://bugs.python.org/issue?@action=redirect&bpo=21408

   (9) https://bugs.python.org/issue?@action=redirect&bpo=23363

   (10) https://bugs.python.org/issue?@action=redirect&bpo=23364

   (11) https://bugs.python.org/issue?@action=redirect&bpo=23366

   (12) https://bugs.python.org/issue?@action=redirect&bpo=23369

   (13) https://bugs.python.org/issue?@action=redirect&bpo=23353

   (14) https://bugs.python.org/issue?@action=redirect&bpo=14099

   (15) https://bugs.python.org/issue?@action=redirect&bpo=14099

   (16) https://bugs.python.org/issue?@action=redirect&bpo=19361

   (17) https://bugs.python.org/issue?@action=redirect&bpo=18518

   (18) https://bugs.python.org/issue?@action=redirect&bpo=23094

   (19) https://bugs.python.org/issue?@action=redirect&bpo=23268

   (20) https://bugs.python.org/issue?@action=redirect&bpo=21408

   (21) https://bugs.python.org/issue?@action=redirect&bpo=19996

   (22) https://bugs.python.org/issue?@action=redirect&bpo=20188

   (23) https://bugs.python.org/issue?@action=redirect&bpo=23133

   (24) https://bugs.python.org/issue?@action=redirect&bpo=23248

   (25) https://bugs.python.org/issue?@action=redirect&bpo=23266

   (26) https://bugs.python.org/issue?@action=redirect&bpo=23098

   (27) https://bugs.python.org/issue?@action=redirect&bpo=21817

   (28) https://bugs.python.org/issue?@action=redirect&bpo=15955

   (29) https://bugs.python.org/issue?@action=redirect&bpo=23250

   (30) https://bugs.python.org/issue?@action=redirect&bpo=23063

   (31) https://bugs.python.org/issue?@action=redirect&bpo=23209

   (32) https://bugs.python.org/issue?@action=redirect&bpo=23225

   (33) https://bugs.python.org/issue?@action=redirect&bpo=17911

   (34) https://bugs.python.org/issue?@action=redirect&bpo=17911

   (35) https://bugs.python.org/issue?@action=redirect&bpo=19777

   (36) https://bugs.python.org/issue?@action=redirect&bpo=23206

   (37) https://bugs.python.org/issue?@action=redirect&bpo=23185

   (38) https://bugs.python.org/issue?@action=redirect&bpo=23186

   (39) https://bugs.python.org/issue?@action=redirect&bpo=23143

   (40) https://bugs.python.org/issue?@action=redirect&bpo=23132

   (41) https://bugs.python.org/issue?@action=redirect&bpo=19776

   (42) https://bugs.python.org/issue?@action=redirect&bpo=23112

   (43) https://bugs.python.org/issue?@action=redirect&bpo=21793

   (44) https://bugs.python.org/issue?@action=redirect&bpo=23093

   (45) https://bugs.python.org/issue?@action=redirect&bpo=23111

   (46) https://bugs.python.org/issue?@action=redirect&bpo=22585

   (47) https://bugs.python.org/issue?@action=redirect&bpo=19104

   (48) https://bugs.python.org/issue?@action=redirect&bpo=23071

   (49) https://bugs.python.org/issue?@action=redirect&bpo=22783

   (50) https://bugs.python.org/issue?@action=redirect&bpo=15513

   (51) https://bugs.python.org/issue?@action=redirect&bpo=19858

   (52) https://bugs.python.org/issue?@action=redirect&bpo=22095

   (53) https://bugs.python.org/issue?@action=redirect&bpo=23016

   (54) https://bugs.python.org/issue?@action=redirect&bpo=21775

   (55) https://bugs.python.org/issue?@action=redirect&bpo=1218234

   (56) https://bugs.python.org/issue?@action=redirect&bpo=21740

   (57) https://bugs.python.org/issue?@action=redirect&bpo=23009

   (58) https://bugs.python.org/issue?@action=redirect&bpo=22959

   (59) https://bugs.python.org/issue?@action=redirect&bpo=22696

   (60) https://bugs.python.org/issue?@action=redirect&bpo=16043

   (61) https://www.cve.org/CVERecord?id=CVE-2013-1753

   (62) https://bugs.python.org/issue?@action=redirect&bpo=14099

   (63) https://bugs.python.org/issue?@action=redirect&bpo=22966

   (64) https://bugs.python.org/issue?@action=redirect&bpo=21971

   (65) https://bugs.python.org/issue?@action=redirect&bpo=21032

   (66) https://bugs.python.org/issue?@action=redirect&bpo=22407

   (67) https://bugs.python.org/issue?@action=redirect&bpo=22902

   (68) https://bugs.python.org/issue?@action=redirect&bpo=22960

   (69) https://bugs.python.org/issue?@action=redirect&bpo=22389

   (70) https://bugs.python.org/issue?@action=redirect&bpo=21356

   (71) https://bugs.python.org/issue?@action=redirect&bpo=22915

   (72) https://bugs.python.org/issue?@action=redirect&bpo=22609

   (73) https://bugs.python.org/issue?@action=redirect&bpo=22940

   (74) https://bugs.python.org/issue?@action=redirect&bpo=19676

   (75) https://bugs.python.org/issue?@action=redirect&bpo=22788

   (76) https://bugs.python.org/issue?@action=redirect&bpo=22921

   (77) https://bugs.python.org/issue?@action=redirect&bpo=22894

   (78) https://bugs.python.org/issue?@action=redirect&bpo=22796

   (79) https://bugs.python.org/issue?@action=redirect&bpo=22370

   (80) https://bugs.python.org/issue?@action=redirect&bpo=22841

   (81) https://bugs.python.org/issue?@action=redirect&bpo=19494

   (82) https://bugs.python.org/issue?@action=redirect&bpo=22578

   (83) https://bugs.python.org/issue?@action=redirect&bpo=22849

   (84) https://bugs.python.org/issue?@action=redirect&bpo=12728

   (85) https://bugs.python.org/issue?@action=redirect&bpo=22821

   (86) https://bugs.python.org/issue?@action=redirect&bpo=21650

   (87) https://bugs.python.org/issue?@action=redirect&bpo=22824

   (88) https://bugs.python.org/issue?@action=redirect&bpo=22824

   (89) https://bugs.python.org/issue?@action=redirect&bpo=22406

   (90) https://bugs.python.org/issue?@action=redirect&bpo=17293

   (91) https://bugs.python.org/issue?@action=redirect&bpo=22769

   (92) https://bugs.python.org/issue?@action=redirect&bpo=22417

   (93) https://bugs.python.org/issue?@action=redirect&bpo=22775

   (94) https://bugs.python.org/issue?@action=redirect&bpo=22776

   (95) https://bugs.python.org/issue?@action=redirect&bpo=22665

   (96) https://bugs.python.org/issue?@action=redirect&bpo=6623

   (97) https://bugs.python.org/issue?@action=redirect&bpo=17381

   (98) https://bugs.python.org/issue?@action=redirect&bpo=22410

   (99) https://bugs.python.org/issue?@action=redirect&bpo=22759

   (100) https://bugs.python.org/issue?@action=redirect&bpo=8876

   (101) https://bugs.python.org/issue?@action=redirect&bpo=22217

   (102) https://bugs.python.org/issue?@action=redirect&bpo=22457

   (103) https://bugs.python.org/issue?@action=redirect&bpo=18216

   (104) https://bugs.python.org/issue?@action=redirect&bpo=13918

   (105) https://bugs.python.org/issue?@action=redirect&bpo=22676

   (106) https://bugs.python.org/issue?@action=redirect&bpo=18853

   (107) https://bugs.python.org/issue?@action=redirect&bpo=9351

   (108) https://bugs.python.org/issue?@action=redirect&bpo=7559

   (109) https://bugs.python.org/issue?@action=redirect&bpo=19746

   (110) https://bugs.python.org/issue?@action=redirect&bpo=21991

   (111) https://bugs.python.org/issue?@action=redirect&bpo=22638

   (112) https://bugs.python.org/issue?@action=redirect&bpo=22641

   (113) https://bugs.python.org/issue?@action=redirect&bpo=17401

   (114) https://bugs.python.org/issue?@action=redirect&bpo=21338

   (115) https://bugs.python.org/issue?@action=redirect&bpo=20152

   (116) https://bugs.python.org/issue?@action=redirect&bpo=18643

   (117) https://bugs.python.org/issue?@action=redirect&bpo=22435

   (118) https://bugs.python.org/issue?@action=redirect&bpo=13096

   (119) https://bugs.python.org/issue?@action=redirect&bpo=11694

   (120) https://bugs.python.org/issue?@action=redirect&bpo=19380

   (121) https://bugs.python.org/issue?@action=redirect&bpo=1519638

   (122) https://bugs.python.org/issue?@action=redirect&bpo=18615

   (123) https://bugs.python.org/issue?@action=redirect&bpo=22462

   (124) https://bugs.python.org/issue?@action=redirect&bpo=21965

   (125) https://bugs.python.org/issue?@action=redirect&bpo=21173

   (126) https://bugs.python.org/issue?@action=redirect&bpo=11866

   (127) https://bugs.python.org/issue?@action=redirect&bpo=21905

   (128) https://bugs.python.org/issue?@action=redirect&bpo=11271

   (129) https://bugs.python.org/issue?@action=redirect&bpo=21883

   (130) https://bugs.python.org/issue?@action=redirect&bpo=22219

   (131) https://bugs.python.org/issue?@action=redirect&bpo=22449

   (132) https://bugs.python.org/issue?@action=redirect&bpo=22508

   (133) https://bugs.python.org/issue?@action=redirect&bpo=20076

   (134) https://bugs.python.org/issue?@action=redirect&bpo=20079

   (135) https://bugs.python.org/issue?@action=redirect&bpo=20218

   (136) https://bugs.python.org/issue?@action=redirect&bpo=22396

   (137) https://bugs.python.org/issue?@action=redirect&bpo=22517

   (138) https://bugs.python.org/issue?@action=redirect&bpo=22437

   (139) https://bugs.python.org/issue?@action=redirect&bpo=17442

   (140) https://bugs.python.org/issue?@action=redirect&bpo=23392

   (141) https://bugs.python.org/issue?@action=redirect&bpo=10510

   (142) https://bugs.python.org/issue?@action=redirect&bpo=9850

   (143) https://bugs.python.org/issue?@action=redirect&bpo=5309

   (144) https://bugs.python.org/issue?@action=redirect&bpo=22448

   (145) https://bugs.python.org/issue?@action=redirect&bpo=22427

   (146) https://bugs.python.org/issue?@action=redirect&bpo=22362

   (147) https://bugs.python.org/issue?@action=redirect&bpo=20912

   (148) https://bugs.python.org/issue?@action=redirect&bpo=21866

   (149) https://bugs.python.org/issue?@action=redirect&bpo=22278

   (150) https://bugs.python.org/issue?@action=redirect&bpo=22415

   (151) https://bugs.python.org/issue?@action=redirect&bpo=22423

   (152) https://bugs.python.org/issue?@action=redirect&bpo=21332

   (153) https://bugs.python.org/issue?@action=redirect&bpo=21091

   (154) https://bugs.python.org/issue?@action=redirect&bpo=21079

   (155) https://bugs.python.org/issue?@action=redirect&bpo=22247

   (156) https://bugs.python.org/issue?@action=redirect&bpo=22366

   (157) https://bugs.python.org/issue?@action=redirect&bpo=4180

   (158) https://bugs.python.org/issue?@action=redirect&bpo=22419

   (159) https://bugs.python.org/issue?@action=redirect&bpo=20537

   (160) https://bugs.python.org/issue?@action=redirect&bpo=22384

   (161) https://bugs.python.org/issue?@action=redirect&bpo=22168

   (162) https://bugs.python.org/issue?@action=redirect&bpo=21147

   (163) https://bugs.python.org/issue?@action=redirect&bpo=13968

   (164) https://bugs.python.org/issue?@action=redirect&bpo=21951

   (165) https://bugs.python.org/issue?@action=redirect&bpo=21951

   (166) https://bugs.python.org/issue?@action=redirect&bpo=22338

   (167) https://bugs.python.org/issue?@action=redirect&bpo=12410

   (168) https://bugs.python.org/issue?@action=redirect&bpo=21270

   (169) https://bugs.python.org/issue?@action=redirect&bpo=16662

   (170) https://bugs.python.org/issue?@action=redirect&bpo=22226

   (171) https://bugs.python.org/issue?@action=redirect&bpo=19524

   (172) https://bugs.python.org/issue?@action=redirect&bpo=20421

   (173) https://bugs.python.org/issue?@action=redirect&bpo=19546

   (174) https://bugs.python.org/issue?@action=redirect&bpo=22051

   (175) https://bugs.python.org/issue?@action=redirect&bpo=21933

   (176) https://bugs.python.org/issue?@action=redirect&bpo=21597

   (177) https://bugs.python.org/issue?@action=redirect&bpo=18132

   (178) https://bugs.python.org/issue?@action=redirect&bpo=22043

   (179) https://bugs.python.org/issue?@action=redirect&bpo=21527

   (180) https://bugs.python.org/issue?@action=redirect&bpo=22216

   (181) https://bugs.python.org/issue?@action=redirect&bpo=22098

   (182) https://bugs.python.org/issue?@action=redirect&bpo=22185

   (183) https://bugs.python.org/issue?@action=redirect&bpo=22287

   (184) https://bugs.python.org/issue?@action=redirect&bpo=22182

   (185) https://bugs.python.org/issue?@action=redirect&bpo=22042

   (186) https://bugs.python.org/issue?@action=redirect&bpo=16808

   (187) https://bugs.python.org/issue?@action=redirect&bpo=22236

   (188) https://bugs.python.org/issue?@action=redirect&bpo=2527

   (189) https://bugs.python.org/issue?@action=redirect&bpo=22118

   (190) https://bugs.python.org/issue?@action=redirect&bpo=21549

   (191) https://bugs.python.org/issue?@action=redirect&bpo=19628

   (192) https://bugs.python.org/issue?@action=redirect&bpo=15696

   (193) https://bugs.python.org/issue?@action=redirect&bpo=22068

   (194) https://bugs.python.org/issue?@action=redirect&bpo=22165

   (195) https://bugs.python.org/issue?@action=redirect&bpo=15381

   (196) https://bugs.python.org/issue?@action=redirect&bpo=8797

   (197) https://bugs.python.org/issue?@action=redirect&bpo=20729

   (198) https://bugs.python.org/issue?@action=redirect&bpo=21448

   (199) https://bugs.python.org/issue?@action=redirect&bpo=22184

   (200) https://bugs.python.org/issue?@action=redirect&bpo=17923

   (201) https://bugs.python.org/issue?@action=redirect&bpo=21725

   (202) https://bugs.python.org/issue?@action=redirect&bpo=22176

   (203) https://bugs.python.org/issue?@action=redirect&bpo=5411

   (204) https://bugs.python.org/issue?@action=redirect&bpo=21121

   (205) https://bugs.python.org/issue?@action=redirect&bpo=21975

   (206) https://bugs.python.org/issue?@action=redirect&bpo=20170

   (207) https://bugs.python.org/issue?@action=redirect&bpo=21539

   (208) https://bugs.python.org/issue?@action=redirect&bpo=22127

   (209) https://bugs.python.org/issue?@action=redirect&bpo=21047

   (210) https://bugs.python.org/issue?@action=redirect&bpo=15114

   (211) https://bugs.python.org/issue?@action=redirect&bpo=22085

   (212) https://bugs.python.org/issue?@action=redirect&bpo=21580

   (213) https://bugs.python.org/issue?@action=redirect&bpo=22003

   (214) https://bugs.python.org/issue?@action=redirect&bpo=22018

   (215) https://bugs.python.org/issue?@action=redirect&bpo=22054

   (216) https://bugs.python.org/issue?@action=redirect&bpo=17172

   (217) https://bugs.python.org/issue?@action=redirect&bpo=21704

   (218) https://bugs.python.org/issue?@action=redirect&bpo=20173

   (219) https://bugs.python.org/issue?@action=redirect&bpo=22033

   (220) https://bugs.python.org/issue?@action=redirect&bpo=21947

   (221) https://bugs.python.org/issue?@action=redirect&bpo=16133

   (222) https://bugs.python.org/issue?@action=redirect&bpo=22044

   (223) https://bugs.python.org/issue?@action=redirect&bpo=19884

   (224) https://bugs.python.org/issue?@action=redirect&bpo=4350

   (225) https://bugs.python.org/issue?@action=redirect&bpo=6167

   (226) https://bugs.python.org/issue?@action=redirect&bpo=15275

   (227) https://bugs.python.org/issue?@action=redirect&bpo=21888

   (228) https://bugs.python.org/issue?@action=redirect&bpo=22032

   (229) https://bugs.python.org/issue?@action=redirect&bpo=22031

   (230) https://bugs.python.org/issue?@action=redirect&bpo=22018

   (231) https://bugs.python.org/issue?@action=redirect&bpo=21044

   (232) https://bugs.python.org/issue?@action=redirect&bpo=21966

   (233) https://bugs.python.org/issue?@action=redirect&bpo=19076

   (234) https://bugs.python.org/issue?@action=redirect&bpo=16382

   (235) https://bugs.python.org/issue?@action=redirect&bpo=21932

   (236) https://bugs.python.org/issue?@action=redirect&bpo=21942

   (237) https://bugs.python.org/issue?@action=redirect&bpo=11259

   (238) https://bugs.python.org/issue?@action=redirect&bpo=12523

   (239) https://bugs.python.org/issue?@action=redirect&bpo=21707

   (240) https://bugs.python.org/issue?@action=redirect&bpo=20639

   (241) https://bugs.python.org/issue?@action=redirect&bpo=21714

   (242) https://bugs.python.org/issue?@action=redirect&bpo=15014

   (243) https://bugs.python.org/issue?@action=redirect&bpo=21151

   (244) https://bugs.python.org/issue?@action=redirect&bpo=21090

   (245) https://bugs.python.org/issue?@action=redirect&bpo=5800

   (246) https://bugs.python.org/issue?@action=redirect&bpo=21781

   (247) https://bugs.python.org/issue?@action=redirect&bpo=21679

   (248) https://bugs.python.org/issue?@action=redirect&bpo=21863

   (249) https://bugs.python.org/issue?@action=redirect&bpo=11453

   (250) https://bugs.python.org/issue?@action=redirect&bpo=21858

   (251) https://bugs.python.org/issue?@action=redirect&bpo=21476

   (252) https://bugs.python.org/issue?@action=redirect&bpo=20295

   (253) https://bugs.python.org/issue?@action=redirect&bpo=21729

   (254) https://bugs.python.org/issue?@action=redirect&bpo=21491

   (255) https://bugs.python.org/issue?@action=redirect&bpo=21719

   (256) https://bugs.python.org/issue?@action=redirect&bpo=21832

   (257) https://bugs.python.org/issue?@action=redirect&bpo=21722

   (258) https://bugs.python.org/issue?@action=redirect&bpo=21723

   (259) https://bugs.python.org/issue?@action=redirect&bpo=21711

   (260) https://bugs.python.org/issue?@action=redirect&bpo=17552

   (261) https://bugs.python.org/issue?@action=redirect&bpo=18039

   (262) https://bugs.python.org/issue?@action=redirect&bpo=21326

   (263) https://bugs.python.org/issue?@action=redirect&bpo=21766

   (264) https://bugs.python.org/issue?@action=redirect&bpo=21310

   (265) https://bugs.python.org/issue?@action=redirect&bpo=21256

   (266) https://bugs.python.org/issue?@action=redirect&bpo=21677

   (267) https://bugs.python.org/issue?@action=redirect&bpo=11709

   (268) https://bugs.python.org/issue?@action=redirect&bpo=21515

   (269) https://bugs.python.org/issue?@action=redirect&bpo=13223

   (270) https://bugs.python.org/issue?@action=redirect&bpo=21463

   (271) https://bugs.python.org/issue?@action=redirect&bpo=21618

   (272) https://bugs.python.org/issue?@action=redirect&bpo=20383

   (273) https://bugs.python.org/issue?@action=redirect&bpo=21552

   (274) https://bugs.python.org/issue?@action=redirect&bpo=14315

   (275) https://bugs.python.org/issue?@action=redirect&bpo=13742

   (276) https://bugs.python.org/issue?@action=redirect&bpo=21402

   (277) https://bugs.python.org/issue?@action=redirect&bpo=3015

   (278) https://bugs.python.org/issue?@action=redirect&bpo=10203

   (279) https://bugs.python.org/issue?@action=redirect&bpo=18807

   (280) https://bugs.python.org/issue?@action=redirect&bpo=20197

   (281) https://bugs.python.org/issue?@action=redirect&bpo=21513

   (282) https://bugs.python.org/issue?@action=redirect&bpo=21137

   (283) https://bugs.python.org/issue?@action=redirect&bpo=21538

   (284) https://bugs.python.org/issue?@action=redirect&bpo=21455

   (285) https://bugs.python.org/issue?@action=redirect&bpo=21525

   (286) https://bugs.python.org/issue?@action=redirect&bpo=22166

   (287) https://bugs.python.org/issue?@action=redirect&bpo=22236

   (288) https://bugs.python.org/issue?@action=redirect&bpo=10744

   (289) https://peps.python.org/pep-3118/

   (290) https://bugs.python.org/issue?@action=redirect&bpo=20826

   (291) https://bugs.python.org/issue?@action=redirect&bpo=21487

   (292) https://bugs.python.org/issue?@action=redirect&bpo=21486

   (293) https://bugs.python.org/issue?@action=redirect&bpo=13916

   (294) https://bugs.python.org/issue?@action=redirect&bpo=20998

   (295) https://bugs.python.org/issue?@action=redirect&bpo=21075

   (296) https://bugs.python.org/issue?@action=redirect&bpo=19775

   (297) https://bugs.python.org/issue?@action=redirect&bpo=21226

   (298) https://bugs.python.org/issue?@action=redirect&bpo=21398

   (299) https://bugs.python.org/issue?@action=redirect&bpo=16531

   (300) https://bugs.python.org/issue?@action=redirect&bpo=21156

   (301) https://bugs.python.org/issue?@action=redirect&bpo=21424

   (302) https://bugs.python.org/issue?@action=redirect&bpo=21396

   (303) https://bugs.python.org/issue?@action=redirect&bpo=18314

   (304) https://bugs.python.org/issue?@action=redirect&bpo=21088

   (305) https://bugs.python.org/issue?@action=redirect&bpo=21407

   (306) https://bugs.python.org/issue?@action=redirect&bpo=10650

   (307) https://bugs.python.org/issue?@action=redirect&bpo=21469

   (308) https://bugs.python.org/issue?@action=redirect&bpo=19414

   (309) https://bugs.python.org/issue?@action=redirect&bpo=21421

   (310) https://bugs.python.org/issue?@action=redirect&bpo=21101

   (311) https://bugs.python.org/issue?@action=redirect&bpo=21321

   (312) https://bugs.python.org/issue?@action=redirect&bpo=21057

   (313) https://bugs.python.org/issue?@action=redirect&bpo=20951

   (314) https://bugs.python.org/issue?@action=redirect&bpo=13248

   (315) https://bugs.python.org/issue?@action=redirect&bpo=9815

   (316) https://bugs.python.org/issue?@action=redirect&bpo=19940

   (317) https://bugs.python.org/issue?@action=redirect&bpo=13204

   (318) https://bugs.python.org/issue?@action=redirect&bpo=19385

   (319) https://bugs.python.org/issue?@action=redirect&bpo=21207

   (320) https://bugs.python.org/issue?@action=redirect&bpo=21291

   (321) https://bugs.python.org/issue?@action=redirect&bpo=21127

   (322) https://bugs.python.org/issue?@action=redirect&bpo=15002

   (323) https://bugs.python.org/issue?@action=redirect&bpo=12220

   (324) https://bugs.python.org/issue?@action=redirect&bpo=21068

   (325) https://bugs.python.org/issue?@action=redirect&bpo=21276

   (326) https://bugs.python.org/issue?@action=redirect&bpo=21262

   (327) https://bugs.python.org/issue?@action=redirect&bpo=21238

   (328) https://bugs.python.org/issue?@action=redirect&bpo=20896

   (329) https://bugs.python.org/issue?@action=redirect&bpo=21239

   (330) https://bugs.python.org/issue?@action=redirect&bpo=21203

   (331) https://bugs.python.org/issue?@action=redirect&bpo=21222

   (332) https://bugs.python.org/issue?@action=redirect&bpo=21197

   (333) https://bugs.python.org/issue?@action=redirect&bpo=17498

   (334) https://bugs.python.org/issue?@action=redirect&bpo=17826

   (335) https://bugs.python.org/issue?@action=redirect&bpo=7776

   (336) https://bugs.python.org/issue?@action=redirect&bpo=20968

   (337) https://bugs.python.org/issue?@action=redirect&bpo=21529

   (338) https://www.cve.org/CVERecord?id=CVE-2014-4616

   (339) https://bugs.python.org/issue?@action=redirect&bpo=21169

   (340) https://bugs.python.org/issue?@action=redirect&bpo=21171

   (341) https://bugs.python.org/issue?@action=redirect&bpo=20539

   (342) https://bugs.python.org/issue?@action=redirect&bpo=21172

   (343) https://bugs.python.org/issue?@action=redirect&bpo=21155

   (344) https://bugs.python.org/issue?@action=redirect&bpo=21136

   (345) https://bugs.python.org/issue?@action=redirect&bpo=17621

   (346) https://bugs.python.org/issue?@action=redirect&bpo=21076

   (347) https://bugs.python.org/issue?@action=redirect&bpo=20636

   (348) https://bugs.python.org/issue?@action=redirect&bpo=19505

   (349) https://bugs.python.org/issue?@action=redirect&bpo=21149

   (350) https://bugs.python.org/issue?@action=redirect&bpo=21058

   (351) https://bugs.python.org/issue?@action=redirect&bpo=21200

   (352) https://bugs.python.org/issue?@action=redirect&bpo=21013

   (353) https://bugs.python.org/issue?@action=redirect&bpo=20145

   (354) https://bugs.python.org/issue?@action=redirect&bpo=20633

   (355) https://bugs.python.org/issue?@action=redirect&bpo=20980

   (356) https://bugs.python.org/issue?@action=redirect&bpo=21082

   (357) https://bugs.python.org/issue?@action=redirect&bpo=20990

   (358) https://bugs.python.org/issue?@action=redirect&bpo=21015

   (359) https://bugs.python.org/issue?@action=redirect&bpo=21000

   (360) https://bugs.python.org/issue?@action=redirect&bpo=20995

   (361) https://bugs.python.org/issue?@action=redirect&bpo=20884

   (362) https://bugs.python.org/issue?@action=redirect&bpo=21499

   (363) https://bugs.python.org/issue?@action=redirect&bpo=20627

   (364) https://bugs.python.org/issue?@action=redirect&bpo=19165

   (365) https://bugs.python.org/issue?@action=redirect&bpo=13936

   (366) https://bugs.python.org/issue?@action=redirect&bpo=18931

   (367) https://bugs.python.org/issue?@action=redirect&bpo=19977

   (368) https://bugs.python.org/issue?@action=redirect&bpo=20574

   (369) https://bugs.python.org/issue?@action=redirect&bpo=20879

   (370) https://bugs.python.org/issue?@action=redirect&bpo=19157

   (371) https://bugs.python.org/issue?@action=redirect&bpo=11599

   (372) https://bugs.python.org/issue?@action=redirect&bpo=4931

   (373) https://bugs.python.org/issue?@action=redirect&bpo=20875

   (374) https://bugs.python.org/issue?@action=redirect&bpo=11558

   (375) https://bugs.python.org/issue?@action=redirect&bpo=20283

   (376) https://bugs.python.org/issue?@action=redirect&bpo=20778

   (377) https://bugs.python.org/issue?@action=redirect&bpo=20791

   (378) https://bugs.python.org/issue?@action=redirect&bpo=19748

   (379) https://bugs.python.org/issue?@action=redirect&bpo=19573

   (380) https://bugs.python.org/issue?@action=redirect&bpo=20726

   (381) https://bugs.python.org/issue?@action=redirect&bpo=17373

   (382) https://bugs.python.org/issue?@action=redirect&bpo=20378

   (383) https://bugs.python.org/issue?@action=redirect&bpo=20816

   (384) https://bugs.python.org/issue?@action=redirect&bpo=20817

   (385) https://bugs.python.org/issue?@action=redirect&bpo=6676

   (386) https://bugs.python.org/issue?@action=redirect&bpo=21117

   (387) https://bugs.python.org/issue?@action=redirect&bpo=20334

   (388) https://bugs.python.org/issue?@action=redirect&bpo=15916

   (389) https://bugs.python.org/issue?@action=redirect&bpo=21209

   (390) https://bugs.python.org/issue?@action=redirect&bpo=163

   (391) https://bugs.python.org/issue?@action=redirect&bpo=21311

   (392) https://bugs.python.org/issue?@action=redirect&bpo=11571

   (393) https://bugs.python.org/issue?@action=redirect&bpo=21801

   (394) https://bugs.python.org/issue?@action=redirect&bpo=21923

   (395) https://bugs.python.org/issue?@action=redirect&bpo=21323

   (396) https://bugs.python.org/issue?@action=redirect&bpo=19435

   (397) https://bugs.python.org/issue?@action=redirect&bpo=22733

   (398) https://bugs.python.org/issue?@action=redirect&bpo=23302


File: python.info,  Node: IDLE<63>,  Next: Build<100>,  Prev: Library<206>,  Up: Python 3 5 0 alpha 1

1.24.119.3 IDLE
...............

   - bpo-20577(1): Configuration of the max line length for the
     FormatParagraph extension has been moved from the General tab of
     the Idle preferences dialog to the FormatParagraph tab of the
     Config Extensions dialog.  Patch by Tal Einat.

   - bpo-16893(2): Update Idle doc chapter to match current Idle and add
     new information.

   - bpo-3068(3): Add Idle extension configuration dialog to Options
     menu.  Changes are written to HOME/.idlerc/config-extensions.cfg.
     Original patch by Tal Einat.

   - bpo-16233(4): A module browser (File : Class Browser, Alt+C)
     requires an editor window with a filename.  When Class Browser is
     requested otherwise, from a shell, output window, or “Untitled”
     editor, Idle no longer displays an error box.  It now pops up an
     Open Module box (Alt+M). If a valid name is entered and a module is
     opened, a corresponding browser is also opened.

   - bpo-4832(5): Save As to type Python files automatically adds .py to
     the name you enter (even if your system does not display it).  Some
     systems automatically add .txt when type is Text files.

   - bpo-21986(6): Code objects are not normally pickled by the pickle
     module.  To match this, they are no longer pickled when running
     under Idle.

   - bpo-17390(7): Adjust Editor window title; remove “Python”, move
     version to end.

   - bpo-14105(8): Idle debugger breakpoints no longer disappear when
     inserting or deleting lines.

   - bpo-17172(9): Turtledemo can now be run from Idle.  Currently, the
     entry is on the Help menu, but it may move to Run.  Patch by
     Ramchandra Apt and Lita Cho.

   - bpo-21765(10): Add support for non-ascii identifiers to
     HyperParser.

   - bpo-21940(11): Add unittest for WidgetRedirector.  Initial patch by
     Saimadhav Heblikar.

   - bpo-18592(12): Add unittest for SearchDialogBase.  Patch by Phil
     Webster.

   - bpo-21694(13): Add unittest for ParenMatch.  Patch by Saimadhav
     Heblikar.

   - bpo-21686(14): add unittest for HyperParser.  Original patch by
     Saimadhav Heblikar.

   - bpo-12387(15): Add missing upper(lower)case versions of default
     Windows key bindings for Idle so Caps Lock does not disable them.
     Patch by Roger Serwy.

   - bpo-21695(16): Closing a Find-in-files output window while the
     search is still in progress no longer closes Idle.

   - bpo-18910(17): Add unittest for textView.  Patch by Phil Webster.

   - bpo-18292(18): Add unittest for AutoExpand.  Patch by Saihadhav
     Heblikar.

   - bpo-18409(19): Add unittest for AutoComplete.  Patch by Phil
     Webster.

   - bpo-21477(20): htest.py - Improve framework, complete set of tests.
     Patches by Saimadhav Heblikar

   - bpo-18104(21): Add idlelib/idle_test/htest.py with a few sample
     tests to begin consolidating and improving human-validated tests of
     Idle.  Change other files as needed to work with htest.  Running
     the module as __main__ runs all tests.

   - bpo-21139(22): Change default paragraph width to 72, the PEP 8(23)
     recommendation.

   - bpo-21284(24): Paragraph reformat test passes after user changes
     reformat width.

   - bpo-17654(25): Ensure IDLE menus are customized properly on OS X
     for non-framework builds and for all variants of Tk.

   - bpo-23180(26): Rename IDLE «Windows» menu item to «Window».  Patch
     by Al Sweigart.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=20577

   (2) https://bugs.python.org/issue?@action=redirect&bpo=16893

   (3) https://bugs.python.org/issue?@action=redirect&bpo=3068

   (4) https://bugs.python.org/issue?@action=redirect&bpo=16233

   (5) https://bugs.python.org/issue?@action=redirect&bpo=4832

   (6) https://bugs.python.org/issue?@action=redirect&bpo=21986

   (7) https://bugs.python.org/issue?@action=redirect&bpo=17390

   (8) https://bugs.python.org/issue?@action=redirect&bpo=14105

   (9) https://bugs.python.org/issue?@action=redirect&bpo=17172

   (10) https://bugs.python.org/issue?@action=redirect&bpo=21765

   (11) https://bugs.python.org/issue?@action=redirect&bpo=21940

   (12) https://bugs.python.org/issue?@action=redirect&bpo=18592

   (13) https://bugs.python.org/issue?@action=redirect&bpo=21694

   (14) https://bugs.python.org/issue?@action=redirect&bpo=21686

   (15) https://bugs.python.org/issue?@action=redirect&bpo=12387

   (16) https://bugs.python.org/issue?@action=redirect&bpo=21695

   (17) https://bugs.python.org/issue?@action=redirect&bpo=18910

   (18) https://bugs.python.org/issue?@action=redirect&bpo=18292

   (19) https://bugs.python.org/issue?@action=redirect&bpo=18409

   (20) https://bugs.python.org/issue?@action=redirect&bpo=21477

   (21) https://bugs.python.org/issue?@action=redirect&bpo=18104

   (22) https://bugs.python.org/issue?@action=redirect&bpo=21139

   (23) https://peps.python.org/pep-0008/

   (24) https://bugs.python.org/issue?@action=redirect&bpo=21284

   (25) https://bugs.python.org/issue?@action=redirect&bpo=17654

   (26) https://bugs.python.org/issue?@action=redirect&bpo=23180


File: python.info,  Node: Build<100>,  Next: C API<79>,  Prev: IDLE<63>,  Up: Python 3 5 0 alpha 1

1.24.119.4 Build
................

   - bpo-15506(1): Use standard PKG_PROG_PKG_CONFIG autoconf macro in
     the configure script.

   - bpo-22935(2): Allow the ssl module to be compiled if openssl
     doesn’t support SSL 3.

   - bpo-22592(3): Drop support of the Borland C compiler to build
     Python.  The distutils module still supports it to build
     extensions.

   - bpo-22591(4): Drop support of MS-DOS, especially of the DJGPP
     compiler (MS-DOS port of GCC).

   - bpo-16537(5): Check whether self.extensions is empty in setup.py.
     Patch by Jonathan Hosmer.

   - bpo-22359(6): Remove incorrect uses of recursive make.  Patch by
     Jonas Wagner.

   - bpo-21958(7): Define HAVE_ROUND when building with Visual Studio
     2013 and above.  Patch by Zachary Turner.

   - bpo-18093(8): the programs that embed the CPython runtime are now
     in a separate «Programs» directory, rather than being kept in the
     Modules directory.

   - bpo-15759(9): «make suspicious», «make linkcheck» and «make
     doctest» in Doc/ now display special message when and only when
     there are failures.

   - bpo-21141(10): The Windows build process no longer attempts to find
     Perl, instead relying on OpenSSL source being configured and ready
     to build.  The ‘PCbuild\build_ssl.py’ script has been re-written
     and re-named to ‘PCbuild\prepare_ssl.py’, and takes care of
     configuring OpenSSL source for both 32 and 64 bit platforms.
     OpenSSL sources obtained from svn.python.org will always be
     pre-configured and ready to build.

   - bpo-21037(11): Add a build option to enable AddressSanitizer
     support.

   - bpo-19962(12): The Windows build process now creates «python.bat»
     in the root of the source tree, which passes all arguments through
     to the most recently built interpreter.

   - bpo-21285(13): Refactor and fix curses configure check to always
     search in a ncursesw directory.

   - bpo-15234(14): For BerkeleyDB and Sqlite, only add the found
     library and include directories if they aren’t already being
     searched.  This avoids an explicit runtime library dependency.

   - bpo-17861(15): Tools/scripts/generate_opcode_h.py automatically
     regenerates Include/opcode.h from Lib/opcode.py if the latter gets
     any change.

   - bpo-20644(16): OS X installer build support for documentation build
     changes in 3.4.1: assume externally supplied sphinx-build is
     available in /usr/bin.

   - bpo-20022(17): Eliminate use of deprecated bundlebuilder in OS X
     builds.

   - bpo-15968(18): Incorporated Tcl, Tk, and Tix builds into the
     Windows build solution.

   - bpo-17095(19): Fix Modules/Setup 'shared' support.

   - bpo-21811(20): Anticipated fixes to support OS X versions > 10.9.

   - bpo-21166(21): Prevent possible segfaults and other random failures
     of python –generate-posix-vars in pybuilddir.txt build target.

   - bpo-18096(22): Fix library order returned by python-config.

   - bpo-17219(23): Add library build dir for Python extension
     cross-builds.

   - bpo-22919(24): Windows build updated to support VC 14.0 (Visual
     Studio 2015), which will be used for the official release.

   - bpo-21236(25): Build _msi.pyd with cabinet.lib instead of fci.lib

   - bpo-17128(26): Use private version of OpenSSL for OS X 10.5+
     installer.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=15506

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22935

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22592

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22591

   (5) https://bugs.python.org/issue?@action=redirect&bpo=16537

   (6) https://bugs.python.org/issue?@action=redirect&bpo=22359

   (7) https://bugs.python.org/issue?@action=redirect&bpo=21958

   (8) https://bugs.python.org/issue?@action=redirect&bpo=18093

   (9) https://bugs.python.org/issue?@action=redirect&bpo=15759

   (10) https://bugs.python.org/issue?@action=redirect&bpo=21141

   (11) https://bugs.python.org/issue?@action=redirect&bpo=21037

   (12) https://bugs.python.org/issue?@action=redirect&bpo=19962

   (13) https://bugs.python.org/issue?@action=redirect&bpo=21285

   (14) https://bugs.python.org/issue?@action=redirect&bpo=15234

   (15) https://bugs.python.org/issue?@action=redirect&bpo=17861

   (16) https://bugs.python.org/issue?@action=redirect&bpo=20644

   (17) https://bugs.python.org/issue?@action=redirect&bpo=20022

   (18) https://bugs.python.org/issue?@action=redirect&bpo=15968

   (19) https://bugs.python.org/issue?@action=redirect&bpo=17095

   (20) https://bugs.python.org/issue?@action=redirect&bpo=21811

   (21) https://bugs.python.org/issue?@action=redirect&bpo=21166

   (22) https://bugs.python.org/issue?@action=redirect&bpo=18096

   (23) https://bugs.python.org/issue?@action=redirect&bpo=17219

   (24) https://bugs.python.org/issue?@action=redirect&bpo=22919

   (25) https://bugs.python.org/issue?@action=redirect&bpo=21236

   (26) https://bugs.python.org/issue?@action=redirect&bpo=17128


File: python.info,  Node: C API<79>,  Next: Documentation<84>,  Prev: Build<100>,  Up: Python 3 5 0 alpha 1

1.24.119.5 C API
................

   - bpo-14203(1): Remove obsolete support for view==NULL in
     PyBuffer_FillInfo(), bytearray_getbuffer(), bytesiobuf_getbuffer()
     and array_buffer_getbuf().  All functions now raise BufferError in
     that case.

   - bpo-22445(2): PyBuffer_IsContiguous() now implements precise
     contiguity tests, compatible with NumPy’s
     NPY_RELAXED_STRIDES_CHECKING compilation flag.  Previously the
     function reported false negatives for corner cases.

   - bpo-22079(3): PyType_Ready() now checks that statically allocated
     type has no dynamically allocated bases.

   - bpo-22453(4): Removed non-documented macro PyObject_REPR().

   - bpo-18395(5): Rename ‘_Py_char2wchar()’ to *note Py_DecodeLocale():
     dc2, rename ‘_Py_wchar2char()’ to *note Py_EncodeLocale(): dc3, and
     document these functions.

   - bpo-21233(6): Add new C functions: PyMem_RawCalloc(),
     PyMem_Calloc(), PyObject_Calloc(), _PyObject_GC_Calloc().
     bytes(int) is now using ‘calloc()’ instead of ‘malloc()’ for large
     objects which is faster and use less memory.

   - bpo-20942(7): PyImport_ImportFrozenModuleObject() no longer sets
     __file__ to match what importlib does; this affects
     _frozen_importlib as well as any module loaded using
     imp.init_frozen().

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=14203

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22445

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22079

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22453

   (5) https://bugs.python.org/issue?@action=redirect&bpo=18395

   (6) https://bugs.python.org/issue?@action=redirect&bpo=21233

   (7) https://bugs.python.org/issue?@action=redirect&bpo=20942


File: python.info,  Node: Documentation<84>,  Next: Tests<88>,  Prev: C API<79>,  Up: Python 3 5 0 alpha 1

1.24.119.6 Documentation
........................

   - bpo-19548(1): Update the codecs module documentation to better
     cover the distinction between text encodings and other codecs,
     together with other clarifications.  Patch by Martin Panter.

   - bpo-22394(2): Doc/Makefile now supports ‘make venv
     PYTHON=../python’ to create a venv for generating the
     documentation, e.g., ‘make html PYTHON=venv/bin/python3’.

   - bpo-21514(3): The documentation of the json module now refers to
     new JSON RFC 7159 instead of obsoleted RFC 4627.

   - bpo-21777(4): The binary sequence methods on bytes and bytearray
     are now documented explicitly, rather than assuming users will be
     able to derive the expected behaviour from the behaviour of the
     corresponding str methods.

   - bpo-6916(5): undocument deprecated asynchat.fifo class.

   - bpo-17386(6): Expanded functionality of the ‘Doc/make.bat’ script
     to make it much more comparable to ‘Doc/Makefile’.

   - bpo-21312(7): Update the thread_foobar.h template file to include
     newer threading APIs.  Patch by Jack McCracken.

   - bpo-21043(8): Remove the recommendation for specific CA
     organizations and to mention the ability to load the OS
     certificates.

   - bpo-20765(9): Add missing documentation for PurePath.with_name()
     and PurePath.with_suffix().

   - bpo-19407(10): New package installation and distribution guides
     based on the Python Packaging Authority tools.  Existing guides
     have been retained as legacy links from the distutils docs, as they
     still contain some required reference material for tool developers
     that isn’t recorded anywhere else.

   - bpo-19697(11): Document cases where __main__.__spec__ is None.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=19548

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22394

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21514

   (4) https://bugs.python.org/issue?@action=redirect&bpo=21777

   (5) https://bugs.python.org/issue?@action=redirect&bpo=6916

   (6) https://bugs.python.org/issue?@action=redirect&bpo=17386

   (7) https://bugs.python.org/issue?@action=redirect&bpo=21312

   (8) https://bugs.python.org/issue?@action=redirect&bpo=21043

   (9) https://bugs.python.org/issue?@action=redirect&bpo=20765

   (10) https://bugs.python.org/issue?@action=redirect&bpo=19407

   (11) https://bugs.python.org/issue?@action=redirect&bpo=19697


File: python.info,  Node: Tests<88>,  Next: Tools/Demos<61>,  Prev: Documentation<84>,  Up: Python 3 5 0 alpha 1

1.24.119.7 Tests
................

   - bpo-18982(1): Add tests for CLI of the calendar module.

   - bpo-19548(2): Added some additional checks to test_codecs to ensure
     that statements in the updated documentation remain accurate.
     Patch by Martin Panter.

   - bpo-22838(3): All test_re tests now work with unittest test
     discovery.

   - bpo-22173(4): Update lib2to3 tests to use unittest test discovery.

   - bpo-16000(5): Convert test_curses to use unittest.

   - bpo-21456(6): Skip two tests in test_urllib2net.py if _ssl module
     not present.  Patch by Remi Pointel.

   - bpo-20746(7): Fix test_pdb to run in refleak mode (-R). Patch by
     Xavier de Gaye.

   - bpo-22060(8): test_ctypes has been somewhat cleaned up and
     simplified; it now uses unittest test discovery to find its tests.

   - bpo-22104(9): regrtest.py no longer holds a reference to the suite
     of tests loaded from test modules that don’t define test_main().

   - bpo-22111(10): Assorted cleanups in test_imaplib.  Patch by Milan
     Oberkirch.

   - bpo-22002(11): Added ‘load_package_tests’ function to test.support
     and used it to implement/augment test discovery in test_asyncio,
     test_email, test_importlib, test_json, and test_tools.

   - bpo-21976(12): Fix test_ssl to accept LibreSSL version strings.
     Thanks to William Orr.

   - bpo-21918(13): Converted test_tools from a module to a package
     containing separate test files for each tested script.

   - bpo-9554(14): Use modern unittest features in test_argparse.
     Initial patch by Denver Coneybeare and Radu Voicilas.

   - bpo-20155(15): Changed HTTP method names in failing tests in
     test_httpservers so that packet filtering software (specifically
     Windows Base Filtering Engine) does not interfere with the
     transaction semantics expected by the tests.

   - bpo-19493(16): Refactored the ctypes test package to skip tests
     explicitly rather than silently.

   - bpo-18492(17): All resources are now allowed when tests are not run
     by regrtest.py.

   - bpo-21634(18): Fix pystone micro-benchmark: use floor division
     instead of true division to benchmark integers instead of
     floating-point numbers.  Set pystone version to 1.2.  Patch written
     by Lennart Regebro.

   - bpo-21605(19): Added tests for Tkinter images.

   - bpo-21493(20): Added test for ntpath.expanduser().  Original patch
     by Claudiu Popa.

   - bpo-19925(21): Added tests for the spwd module.  Original patch by
     Vajrasky Kok.

   - bpo-21522(22): Added Tkinter tests for Listbox.itemconfigure(),
     PanedWindow.paneconfigure(), and Menu.entryconfigure().

   - bpo-17756(23): Fix test_code test when run from the installed
     location.

   - bpo-17752(24): Fix distutils tests when run from the installed
     location.

   - bpo-18604(25): Consolidated checks for GUI availability.  All
     platforms now at least check whether Tk can be instantiated when
     the GUI resource is requested.

   - bpo-21275(26): Fix a socket test on KFreeBSD.

   - bpo-21223(27): Pass test_site/test_startup_imports when some of the
     extensions are built as builtins.

   - bpo-20635(28): Added tests for Tk geometry managers.

   - Add test case for freeze.

   - bpo-20743(29): Fix a reference leak in test_tcl.

   - bpo-21097(30): Move test_namespace_pkgs into test_importlib.

   - bpo-21503(31): Use test_both() consistently in test_importlib.

   - bpo-20939(32): Avoid various network test failures due to new
     redirect of ‘http://www.python.org/’ to ‘https://www.python.org’:
     use ‘http://www.example.com’ instead.

   - bpo-20668(33): asyncio tests no longer rely on tests.txt file.
     (Patch by Vajrasky Kok)

   - bpo-21093(34): Prevent failures of ctypes test_macholib on OS X if
     a copy of libz exists in $HOME/lib or /usr/local/lib.

   - bpo-22770(35): Prevent some Tk segfaults on OS X when running gui
     tests.

   - bpo-23211(36): Workaround test_logging failure on some OS X 10.6
     systems.

   - bpo-23345(37): Prevent test_ssl failures with large OpenSSL patch
     level values (like 0.9.8zc).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18982

   (2) https://bugs.python.org/issue?@action=redirect&bpo=19548

   (3) https://bugs.python.org/issue?@action=redirect&bpo=22838

   (4) https://bugs.python.org/issue?@action=redirect&bpo=22173

   (5) https://bugs.python.org/issue?@action=redirect&bpo=16000

   (6) https://bugs.python.org/issue?@action=redirect&bpo=21456

   (7) https://bugs.python.org/issue?@action=redirect&bpo=20746

   (8) https://bugs.python.org/issue?@action=redirect&bpo=22060

   (9) https://bugs.python.org/issue?@action=redirect&bpo=22104

   (10) https://bugs.python.org/issue?@action=redirect&bpo=22111

   (11) https://bugs.python.org/issue?@action=redirect&bpo=22002

   (12) https://bugs.python.org/issue?@action=redirect&bpo=21976

   (13) https://bugs.python.org/issue?@action=redirect&bpo=21918

   (14) https://bugs.python.org/issue?@action=redirect&bpo=9554

   (15) https://bugs.python.org/issue?@action=redirect&bpo=20155

   (16) https://bugs.python.org/issue?@action=redirect&bpo=19493

   (17) https://bugs.python.org/issue?@action=redirect&bpo=18492

   (18) https://bugs.python.org/issue?@action=redirect&bpo=21634

   (19) https://bugs.python.org/issue?@action=redirect&bpo=21605

   (20) https://bugs.python.org/issue?@action=redirect&bpo=21493

   (21) https://bugs.python.org/issue?@action=redirect&bpo=19925

   (22) https://bugs.python.org/issue?@action=redirect&bpo=21522

   (23) https://bugs.python.org/issue?@action=redirect&bpo=17756

   (24) https://bugs.python.org/issue?@action=redirect&bpo=17752

   (25) https://bugs.python.org/issue?@action=redirect&bpo=18604

   (26) https://bugs.python.org/issue?@action=redirect&bpo=21275

   (27) https://bugs.python.org/issue?@action=redirect&bpo=21223

   (28) https://bugs.python.org/issue?@action=redirect&bpo=20635

   (29) https://bugs.python.org/issue?@action=redirect&bpo=20743

   (30) https://bugs.python.org/issue?@action=redirect&bpo=21097

   (31) https://bugs.python.org/issue?@action=redirect&bpo=21503

   (32) https://bugs.python.org/issue?@action=redirect&bpo=20939

   (33) https://bugs.python.org/issue?@action=redirect&bpo=20668

   (34) https://bugs.python.org/issue?@action=redirect&bpo=21093

   (35) https://bugs.python.org/issue?@action=redirect&bpo=22770

   (36) https://bugs.python.org/issue?@action=redirect&bpo=23211

   (37) https://bugs.python.org/issue?@action=redirect&bpo=23345


File: python.info,  Node: Tools/Demos<61>,  Next: Windows<82>,  Prev: Tests<88>,  Up: Python 3 5 0 alpha 1

1.24.119.8 Tools/Demos
......................

   - bpo-22314(1): pydoc now works when the LINES environment variable
     is set.

   - bpo-22615(2): Argument Clinic now supports the «type» argument for
     the int converter.  This permits using the int converter with enums
     and typedefs.

   - bpo-20076(3): The makelocalealias.py script no longer ignores UTF-8
     mapping.

   - bpo-20079(4): The makelocalealias.py script now can parse the
     SUPPORTED file from glibc sources and supports command line options
     for source paths.

   - bpo-22201(5): Command-line interface of the zipfile module now
     correctly extracts ZIP files with directory entries.  Patch by Ryan
     Wilson.

   - bpo-22120(6): For functions using an unsigned integer return
     converter, Argument Clinic now generates a cast to that type for
     the comparison to -1 in the generated code.  (This suppresses a
     compilation warning.)

   - bpo-18974(7): Tools/scripts/diff.py now uses argparse instead of
     optparse.

   - bpo-21906(8): Make Tools/scripts/md5sum.py work in Python 3.  Patch
     by Zachary Ware.

   - bpo-21629(9): Fix Argument Clinic’s «–converters» feature.

   - Add support for ‘yield from’ to 2to3.

   - Add support for the PEP 465(10) matrix multiplication operator to
     2to3.

   - bpo-16047(11): Fix module exception list and __file__ handling in
     freeze.  Patch by Meador Inge.

   - bpo-11824(12): Consider ABI tags in freeze.  Patch by Meador Inge.

   - bpo-20535(13): PYTHONWARNING no longer affects the run_tests.py
     script.  Patch by Arfrever Frehtes Taifersar Arahesis.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=22314

   (2) https://bugs.python.org/issue?@action=redirect&bpo=22615

   (3) https://bugs.python.org/issue?@action=redirect&bpo=20076

   (4) https://bugs.python.org/issue?@action=redirect&bpo=20079

   (5) https://bugs.python.org/issue?@action=redirect&bpo=22201

   (6) https://bugs.python.org/issue?@action=redirect&bpo=22120

   (7) https://bugs.python.org/issue?@action=redirect&bpo=18974

   (8) https://bugs.python.org/issue?@action=redirect&bpo=21906

   (9) https://bugs.python.org/issue?@action=redirect&bpo=21629

   (10) https://peps.python.org/pep-0465/

   (11) https://bugs.python.org/issue?@action=redirect&bpo=16047

   (12) https://bugs.python.org/issue?@action=redirect&bpo=11824

   (13) https://bugs.python.org/issue?@action=redirect&bpo=20535


File: python.info,  Node: Windows<82>,  Prev: Tools/Demos<61>,  Up: Python 3 5 0 alpha 1

1.24.119.9 Windows
..................

   - bpo-23260(1): Update Windows installer

   - The bundled version of Tcl/Tk has been updated to 8.6.3.  The most
     visible result of this change is the addition of new native file
     dialogs when running on Windows Vista or newer.  See Tcl/Tk’s TIP
     432 for more information.  Also, this version of Tcl/Tk includes
     support for Windows 10.

   - bpo-17896(2): The Windows build scripts now expect external library
     sources to be in ‘PCbuild\..\externals’ rather than
     ‘PCbuild\..\..’.

   - bpo-17717(3): The Windows build scripts now use a copy of NASM
     pulled from svn.python.org to build OpenSSL.

   - bpo-21907(4): Improved the batch scripts provided for building
     Python.

   - bpo-22644(5): The bundled version of OpenSSL has been updated to
     1.0.1j.

   - bpo-10747(6): Use versioned labels in the Windows start menu.
     Patch by Olive Kilburn.

   - bpo-22980(7): .pyd files with a version and platform tag (for
     example, «.cp35-win32.pyd») will now be loaded in preference to
     those without tags.

'(For information about older versions, consult the HISTORY file.)'

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=23260

   (2) https://bugs.python.org/issue?@action=redirect&bpo=17896

   (3) https://bugs.python.org/issue?@action=redirect&bpo=17717

   (4) https://bugs.python.org/issue?@action=redirect&bpo=21907

   (5) https://bugs.python.org/issue?@action=redirect&bpo=22644

   (6) https://bugs.python.org/issue?@action=redirect&bpo=10747

   (7) https://bugs.python.org/issue?@action=redirect&bpo=22980


File: python.info,  Node: Tutorial su Python,  Next: Python Setup and Usage,  Prev: Novità in Python,  Up: Top

2 Tutorial su Python
********************

     Suggerimento: This tutorial is designed for 'programmers' that are
     new to the Python language, 'not' 'beginners' who are new to
     programming.

Python è un linguaggio di programmazione potente e facile da imparare.
Dispone di strutture di dati efficienti e di alto livello e di un
approccio semplice ma efficace alla programmazione orientata agli
oggetti.  La sintassi elegante e la tipizzazione dinamica di Python,
insieme alla sua natura interpretata, ne fanno un linguaggio ideale per
lo scripting e il rapido sviluppo di applicazioni in molte aree per la
maggior parte delle piattaforme.

The Python interpreter and the extensive standard library are freely
available in source or binary form for all major platforms from the
Python website, ‘https://www.python.org/’, and may be freely
distributed.  The same site also contains distributions of and pointers
to many free third party Python modules, programs and tools, and
additional documentation.

L’interprete Python è facilmente ampliabile con nuove funzioni e tipi di
dati implementati in C o C++ (o altri linguaggi richiamabili da C).
Python è adatto anche come linguaggio di estensione per applicazioni
personalizzabili.

This tutorial introduces the reader informally to the basic concepts and
features of the Python language and system.  Be aware that it expects
you to have a basic understanding of programming in general.  It helps
to have a Python interpreter handy for hands-on experience, but all
examples are self-contained, so the tutorial can be read off-line as
well.

Per una descrizione degli oggetti e dei moduli standard, si veda *note
The Python Standard Library: 149.  *note The Python Language Reference:
14a. fornisce una definizione più formale del linguaggio.  Per scrivere
le estensioni in C o C++, si legga *note Extending and Embedding the
Python Interpreter: 1fa5. e *note Python/C API Reference Manual: 1fa6.
Ci sono anche diversi libri che coprono Python in profondità.

Questo tutorial non vuole essere completo e coprire ogni singola
caratteristica, come pure ogni caratteristica usata comunemente.
Invece, introduce molte delle caratteristiche più importanti di Python,
e vi darà una buona idea sullo stile del linguaggio.  Dopo averlo letto,
sarete in grado di leggere e scrivere moduli e programmi Python, e
sarete pronti per saperne di più sui vari moduli della libreria Python,
i quali sono descritti in *note The Python Standard Library: 149.

Anche il *note Glossary: 1fa7. vale la pena di essere sfogliato.

* Menu:

* Stuzzichiamo il tuo appetito::
* Uso dell’interprete di Python::
* Un’introduzione informale a Python::
* Altri Strumenti di Controllo del Flusso::
* Strutture Dati::
* Moduli::
* Input e Output::
* Errori ed Eccezioni::
* Classi::
* Breve Panoramica della Libreria Standard::
* Giro Breve della Libreria Standard — Parte II::
* Ambienti Virtuali e Pacchetti::
* E adesso?::
* Editing dell’input interattivo e sostituzione della history::
* Floating-Point Arithmetic; Issues and Limitations: Floating-Point Arithmetic Issues and Limitations.
* Appendice::


File: python.info,  Node: Stuzzichiamo il tuo appetito,  Next: Uso dell’interprete di Python,  Up: Tutorial su Python

2.1 Stuzzichiamo il tuo appetito
================================

Se si fa molto lavoro sui computer, alla fine si scopre che c’è qualche
compito che si desidera automatizzare.  Ad esempio, è possibile eseguire
un “ricerca e sostituisci” su un gran numero di file di testo, oppure
rinominare e riorganizzare un gruppo di file di foto in modo complesso.
Magari vi piacerebbe scrivere un piccolo database personalizzato, o
un’applicazione GUI specializzata, o un semplice gioco.

Se sei uno sviluppatore di software professionista, potresti dover
lavorare con diverse librerie C/C+++/Java, ma il solito ciclo di
scrittura/compilazione/test/ricompilazione è troppo lento.  Forse stai
scrivendo una suite di test per una libreria di questo tipo e credi che
la scrittura del codice di test sia un compito noioso.  O forse avete
scritto un programma che potrebbe utilizzare una libreria che usa un
proprio linguaggio di programmazione, e non volete progettare e
implementare un linguaggio completamente nuovo per la vostra
applicazione.

Python è il linguaggio che fa per te.

Si potrebbe scrivere uno script di shell Unix o file batch di Windows
per alcune di queste attività, tuttavia se è vero che gli script di
shell sono i migliori per spostarsi tra i file o modificare i file di
testo, non sono adatti per applicazioni GUI o giochi.  Si potrebbe
scrivere un programma C/C+++/Java, ma può essere necessario molto tempo
di sviluppo per ottenere anche solo una prima bozza di programma.
Python è più semplice da usare, disponibile su Windows, Mac OS X e Unix,
e vi aiuterà a svolgere il lavoro più rapidamente.

Python è semplice da usare, ma è un vero e proprio linguaggio di
programmazione, che offre una struttura e un supporto per programmi di
grandi dimensioni molto più di quanto possano offrire script di shell o
file batch.  D’altra parte, Python offre anche molto più controllo degli
errori di C e, essendo un linguaggio 'di altissimo livello', ha tipi di
dati di alto livello integrati, come array flessibili e dizionari.  A
causa dei suoi tipi di dati più generali, Python è applicabile ad un
dominio molto più grande di Awk o anche di Perl, ma molte cose sono
almeno altrettanto facili in Python come in quei linguaggi.

Python permette di suddividere il programma in moduli che possono essere
riutilizzati in altri programmi Python.  Viene fornito con una vasta
collezione di moduli standard che potete usare come base dei vostri
programmi — o come esempi per iniziare ad imparare a programmare in
Python.  Alcuni di questi moduli forniscono cose come I/O di file,
chiamate di sistema, socket e persino strumenti per lo sviluppo di
interfacce grafiche utente come Tk.

Python è un linguaggio interpretato, che può farvi risparmiare molto
tempo durante lo sviluppo del programma perché non è necessaria alcuna
compilazione e 'linking'.  L’interprete può essere usato in modo
interattivo, il che rende facile sperimentare con le caratteristiche del
linguaggio, scrivere programmi usa e getta o testare le funzioni durante
lo sviluppo del programma dal basso verso l’alto.  È anche una pratica
calcolatrice da tavolo.

Python consente di scrivere programmi in modo compatto e leggibile.  I
programmi scritti in Python sono in genere molto più brevi dei programmi
equivalenti in C, C+++ o Java, per diversi motivi:

   * i tipi di dati di alto livello consentono di esprimere operazioni
     complesse in un’unica dichiarazione;

   * il raggruppamento delle istruzioni è fatto usando l’indentazione
     invece che per parentesi iniziali e finali;

   * non sono necessarie dichiarazioni di variabili o argomenti.

Python è 'estensibile': se si conosce la programmazione in C è facile
aggiungere una nuova funzione o un modulo all’interprete, sia per
eseguire operazioni critiche alla massima velocità, sia per collegare
programmi Python a librerie che possono essere disponibili solo in forma
di eseguibili binari (come una libreria grafica fornita da un
fornitore).  Una volta che ci si è fatto il callo, è possibile anche
collegare l’interprete Python ad un’applicazione scritta in C e usarlo
come un’estensione o come linguaggio per impartire comandi a
quell’applicazione.

A proposito, la lingua prende il nome dallo show della BBC «Monty
Python’s Flying Circus» e non ha nulla a che fare con i rettili.  Fare
riferimento agli schetch Monty Python nella documentazione non solo è
permesso, ma è incoraggiato!

Ora che siete tutti entusiasti di Python, vorrete esaminarlo più in
dettaglio.  Poiché il modo migliore per imparare un linguaggio è usarlo,
il tutorial vi invita a giocare con l’interprete Python mentre lo
leggete.

Nel capitolo successivo vengono spiegate le modalità di utilizzo
dell’interprete.  Si tratta di informazioni piuttosto banali, ma
essenziali per provare gli esempi mostrati in seguito.

Il resto del tutorial introduce varie caratteristiche del linguaggio e
del sistema Python attraverso esempi, iniziando con semplici
espressioni, comandi e tipi di dati, attraverso funzioni e moduli, e
infine toccando concetti avanzati come eccezioni e classi definite
dall’utente.


File: python.info,  Node: Uso dell’interprete di Python,  Next: Un’introduzione informale a Python,  Prev: Stuzzichiamo il tuo appetito,  Up: Tutorial su Python

2.2 Uso dell’interprete di Python
=================================

* Menu:

* Invocazione dell’interprete::
* L’interprete e il suo ambiente::


File: python.info,  Node: Invocazione dell’interprete,  Next: L’interprete e il suo ambiente,  Up: Uso dell’interprete di Python

2.2.1 Invocazione dell’interprete
---------------------------------

L’interprete Python è solitamente installato come
‘/usr/local/bin/python3.14’ su quelle macchine dove è disponibile;
aggiungere ‘/usr/local/bin’ al path di ricerca della vostra shell Unix
rende possibile avviarlo digitando il comando:

     python3.14

alla shell.  (1)  Poiché la scelta della cartella in cui è situato
l’interprete è un’opzione di installazione, è possibile trovarlo anche
in altri percorsi; verificate con il vostro guru Python o con
l’amministratore di sistema.  (Ad esempio, ‘/usr/local/python’ è
un’alternativa popolare.)

Sulle macchine Windows dove hai installato Python dallo *note Microsoft
Store: 1fb1, il comando ‘python3.14’ sarà disponibile.  Se hai
installato il *note py.exe launcher: 7db, puoi utilizzare il comando
‘py’.  Consulta *note Python install manager: 1fb2. per altri modi di
avviare Python.

Digitando un carattere di fine file (‘Control’-‘D’ su Unix,
‘Control’-‘Z’ su Windows) nel prompt, l’interprete esce con stato zero.
Se non funziona, è possibile uscire dall’interprete digitando il
seguente comando: ‘quit()’.

The interpreter’s line-editing features include interactive editing,
history substitution and code completion on most systems.  Perhaps the
quickest check to see whether command line editing is supported is
typing a word in on the Python prompt, then pressing Left arrow (or
‘Control’-‘b’).  If the cursor moves, you have command line editing; see
Appendix *note Editing dell’input interattivo e sostituzione della
history: 1fb3. for an introduction to the keys.  If nothing appears to
happen, or if a sequence like ‘^[[D’ or ‘^B’ appears, command line
editing isn’t available; you’ll only be able to use backspace to remove
characters from the current line.

L’interprete opera in maniera simile alla shell Unix: quando viene
chiamato con lo 'standard input' collegato ad un dispositivo tty, legge
ed esegue i comandi in modo interattivo; quando viene chiamato con un
nome di file come argomento o con un file come 'standard input', legge
ed esegue un 'script' da quel file.

Un secondo modo di iniziare l’interprete è ‘python -c command [arg]
...’, che esegue le istruzioni in 'command', analogamente all’opzione
*note -c: 1a8.  Poiché le istruzioni di Python spesso contengono spazi o
altri caratteri speciali per la shell, di solito si consiglia di
racchiudere 'command', nella sua interezza, con apici singoli.

Alcuni moduli Python sono utili anche come script.  Questi possono
essere invocati usando ‘python -m module [arg] ...’, che esegue il file
sorgente del 'modulo' come se tu avessi scritto il suo nome completo
sulla riga di comando.

Quando si utilizza un file di script, a volte è utile essere in grado di
eseguire lo script ed entrare in modalità interattiva in seguito.
Questo può essere fatto passando *note -i: 16e2. prima dello script.

Tutte le opzioni della riga di comando sono descritte in *note Command
line and environment: 1d8f.

* Menu:

* Passare Argomenti::
* Modalità Interattiva::

   ---------- Footnotes ----------

   (1) Su Unix, l’interprete Python 3.x non è installato di default con
l’eseguibile chiamato ‘python’, in modo che non sia in conflitto con un
eseguibile Python 2.x installato contemporaneamente.


File: python.info,  Node: Passare Argomenti,  Next: Modalità Interattiva,  Up: Invocazione dell’interprete

2.2.1.1 Passare Argomenti
.........................

Una volta resi noti all’interprete, il nome dello script e gli argomenti
aggiuntivi vengono poi trasformati in una lista di stringhe e assegnati
alla variabile ‘argv’ nel modulo ‘sys’.  È possibile accedere a questa
lista eseguendo ‘importa sys’.  La lunghezza della lista è almeno una;
quando non viene dato alcuno script e nessun argomento, ‘sys.argv[0]’ è
una stringa vuota.  Quando il nome dello script è dato come ‘'-'’ (che
significa ingresso standard), ‘sys.argv[0]’ è settato a ‘’-‘’.  Quando è
usato il 'comando' *note -c: 1a8, ‘sys.argv[0]’ viene settato a ‘’-c’’.
Quando viene usato il 'modulo' *note -m: 23c, ‘sys.argv[0]’ viene
impostato con il nome completo del modulo.  Tutte le opzioni trovate
dopo i comandi *note -c: 1a8. o i moduli *note -m: 23c. non vengono
consumati dell’interprete di Python che processa le opzioni, ma vengono
lasciate in ‘sys.argv’ in modo che vengano poi gestite manualmente dal
comando o dal modulo.


File: python.info,  Node: Modalità Interattiva,  Prev: Passare Argomenti,  Up: Invocazione dell’interprete

2.2.1.2 Modalità Interattiva
............................

Quando i comandi vengono letti da una tty, l’interprete è detto essere
in 'modo interattivo'.  In questa modalità richiede il comando
successivo con il 'prompt', di solito tre simboli di 'maggiore di'
(‘>>>’); per le linee di continuazione viene emesso un 'prompt'
secondario, che per impostazione predefinita consiste di tre punti
(‘...’).  L’interprete stampa un messaggio di benvenuto indicando il
numero di versione e un avviso di copyright prima di stampare il
'prompt':

     $ python3.14
     Python 3.14 (default, April 4 2024, 09:25:04)
     [GCC 10.2.0] on linux
     Type "help", "copyright", "credits" or "license" for more information.
     >>>

Le linee di continuazione sono necessarie quando si inserisce un
costrutto su più linee.  Come esempio, date un’occhiata a questa
dichiarazione *note if: 181.:

     >>> the_world_is_flat = True
     >>> if the_world_is_flat:
     ...     print("Be careful not to fall off!")
     ...
     Be careful not to fall off!

Per ulteriori informazioni sulla modalità interattiva, vedere *note
Modalità Interattiva: 495.


File: python.info,  Node: L’interprete e il suo ambiente,  Prev: Invocazione dell’interprete,  Up: Uso dell’interprete di Python

2.2.2 L’interprete e il suo ambiente
------------------------------------

* Menu:

* Codifica del codice sorgente::


File: python.info,  Node: Codifica del codice sorgente,  Up: L’interprete e il suo ambiente

2.2.2.1 Codifica del codice sorgente
....................................

Per impostazione predefinita, i file sorgente di Python sono trattati
come codificati in UTF-8.  In questa codifica, i caratteri della maggior
parte delle lingue del mondo possono essere usati simultaneamente in
stringhe, variabili e commenti — la libreria standard tuttavia usa solo
caratteri ASCII per le variabili, una convenzione che ogni codice
portatile dovrebbe seguire.  Per visualizzare correttamente tutti questi
caratteri, l’editor deve riconoscere che il file è UTF-8, e deve
utilizzare un font che supporti tutti i caratteri del file.

Per dichiarare una codifica diversa da quella predefinita, è necessario
aggiungere un commento speciale come 'prima' riga del file.  La sintassi
è la seguente:

     # -*- coding: encoding -*-

dove 'codifica' è uno dei *note codecs: 1c. validi supportati da Python.

Per esempio, per dichiarare che deve essere usata la codifica
Windows-1252, la prima riga del file del codice sorgente dovrebbe
essere:

     # -*- coding: cp1252 -*-

Un’eccezione alla regola della 'prima linea' è quando il codice sorgente
inizia con una linea *note UNIX “shebang” line: 1fbb.  In questo caso,
la dichiarazione della codifica dovrebbe essere aggiunta come seconda
riga del file.  Per esempio:

     #!/usr/bin/env python3
     # -*- coding: cp1252 -*-

Note
....


File: python.info,  Node: Un’introduzione informale a Python,  Next: Altri Strumenti di Controllo del Flusso,  Prev: Uso dell’interprete di Python,  Up: Tutorial su Python

2.3 Un’introduzione informale a Python
======================================

Nei seguenti esempi, input e output si distinguono per la presenza o
meno del prompt (*note >>>: 493. e *note …: 494.): per ripetere
l’esempio, è necessario digitare tutto dopo il prompt, quando questo è
presente; le righe che non iniziano con un prompt vengono emesse
dall’interprete.  Si noti che un prompt secondario su una linea da solo
in un esempio significa che è necessario digitare una riga vuota; questo
viene utilizzato per terminare un comando a più righe.

Molti degli esempi di questo manuale, anche quelli inseriti al prompt
interattivo, includono commenti.  I commenti in Python iniziano con il
carattere 'hash', ‘#’, e si estendono fino alla fine della riga.  Un
commento può apparire all’inizio di una riga o dopo uno spazio bianco o
codice, ma non all’interno di una stringa.  Un carattere hash
all’interno di una stringa letterale è solo un carattere.  Poiché i
commenti servono solo a chiarire il codice e non sono interpretati da
Python, possono essere omessi quando si scrivono gli esempi.

Alcuni esempi:

     # this is the first comment
     spam = 1  # and this is the second comment
               # ... and now a third!
     text = "# This is not a comment because it's inside quotes."

* Menu:

* Usare Python come calcolatrice::
* Primi passi di programmazione::


File: python.info,  Node: Usare Python come calcolatrice,  Next: Primi passi di programmazione,  Up: Un’introduzione informale a Python

2.3.1 Usare Python come calcolatrice
------------------------------------

Proviamo con alcuni semplici comandi di Python.  Avviare l’interprete e
attendere il prompt primario, ‘>>>’.  (Non dovrebbe volerci molto.)

* Menu:

* Numeri::
* Testo::
* Liste::


File: python.info,  Node: Numeri,  Next: Testo,  Up: Usare Python come calcolatrice

2.3.1.1 Numeri
..............

The interpreter acts as a simple calculator: you can type an expression
into it and it will write the value.  Expression syntax is
straightforward: the operators ‘+’, ‘-’, ‘*’ and ‘/’ can be used to
perform arithmetic; parentheses (‘()’) can be used for grouping.  For
example:

     >>> 2 + 2
     4
     >>> 50 - 5*6
     20
     >>> (50 - 5*6) / 4
     5.0
     >>> 8 / 5  # division always returns a floating-point number
     1.6

I numeri interi (es.  ‘2’, ‘4’, ‘20’) hanno tipo *note int: 19b, quelli
in virgola mobile (es.  ‘5.0’, ‘1.6’) hanno tipo *note float: 196.
Torneremo a parlare ancora dei tipi numerici più avanti nel tutorial.

La divisione (‘/’) restituisce sempre un float.  Per fare *note floor
division: b40. e ottenere un risultato intero (scartando qualsiasi cifra
decimale) si può usare l’operatore ‘//’; per calcolare il resto si può
usare ‘%’:

     >>> 17 / 3  # classic division returns a float
     5.666666666666667
     >>>
     >>> 17 // 3  # floor division discards the fractional part
     5
     >>> 17 % 3  # the % operator returns the remainder of the division
     2
     >>> 5 * 3 + 2  # floored quotient * divisor + remainder
     17

Con Python, è possibile utilizzare l’operatore ‘**’ per calcolare le
potenze (1):

     >>> 5 ** 2  # 5 squared
     25
     >>> 2 ** 7  # 2 to the power of 7
     128

Il segno uguale (‘=’) è usato per assegnare un valore ad una variabile.
Successivamente, nessun risultato viene visualizzato prima della
successiva richiesta:

     >>> width = 20
     >>> height = 5 * 9
     >>> width * height
     900

Se una variabile non è stata ”definita» (a cui è stato assegnato un
valore), usarla vi darà un errore:

     >>> n  # try to access an undefined variable
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     NameError: name 'n' is not defined

C’è pieno supporto per i numeri in virgola mobile; gli operatori con
operandi di tipo misto convertono l’intero in un numero in virgola
mobile:

     >>> 4 * 3.75 - 1
     14.0

In modalità interattiva, l’ultima espressione stampata viene assegnata
alla variabile ‘_’.  Questo significa che quando si utilizza Python come
calcolatrice da tavolo, è un po” più facile continuare i calcoli, ad
esempio:

     >>> tax = 12.5 / 100
     >>> price = 100.50
     >>> price * tax
     12.5625
     >>> price + _
     113.0625
     >>> round(_, 2)
     113.06

Questa variabile deve essere trattata dall’utente in sola lettura.  Non
va assegnato esplicitamente un valore ad essa — si dovrebbe invece
creare una variabile locale indipendente con lo stesso nome, mascherando
così la variabile 'built-in' e il suo comportamento magico.

Oltre a *note int: 19b. e *note float: 196, Python supporta altri tipi
di numeri, come *note Decimal: 1fe. e *note Fraction: 213.  Python ha
anche il supporto incorporato per *note complex numbers: 1fc4, e usa il
suffisso ‘j’ o ‘J’ per indicare la parte immaginaria (es.  ‘3+5j’).

   ---------- Footnotes ----------

   (1) Poiché ‘**’ ha una precedenza superiore a ‘-’, ‘-3**2’ sarà
interpretato come ‘-(3**2)’ e quindi risulterà in ‘-9’.  Per evitare
questo e ottenere ‘9’, è possibile utilizzare ‘(-3)**2’.


File: python.info,  Node: Testo,  Next: Liste,  Prev: Numeri,  Up: Usare Python come calcolatrice

2.3.1.2 Testo
.............

Python può manipolare testo (rappresentato dal tipo *note str: 169, le
cosiddette «stringhe») così come numeri.  Questo include caratteri
«‘!’», parole «‘rabbit’», nomi «‘Paris’», frasi «‘Got your back.’», ecc.
«‘Yay! :)’».  Possono essere racchiusi tra virgolette singole (‘'...'’)
o virgolette doppie (‘"..."’) con lo stesso risultato (1).

     >>> 'spam eggs'  # single quotes
     'spam eggs'
     >>> "Paris rabbit got your back :)! Yay!"  # double quotes
     'Paris rabbit got your back :)! Yay!'
     >>> '1975'  # digits and numerals enclosed in quotes are also strings
     '1975'

racchiudere una virgoletta dello stesso tipo, dobbiamo farne l“«escape»,
precedendola con ‘\’.  In alternativa, possiamo usare l’altro tipo di
virgolette:

     >>> 'doesn\'t'  # use \' to escape the single quote...
     "doesn't"
     >>> "doesn't"  # ...or use double quotes instead
     "doesn't"
     >>> '"Yes," they said.'
     '"Yes," they said.'
     >>> "\"Yes,\" they said."
     '"Yes," they said.'
     >>> '"Isn\'t," they said.'
     '"Isn\'t," they said.'

Nella shell di Python, la definizione di una stringa e la stringa di
output possono apparire differenti.  La funzione *note print(): 1177.
produce un output più leggibile, omettendo le virgolette di chiusura e
stampando i caratteri con escape e speciali:

     >>> s = 'First line.\nSecond line.'  # \n means newline
     >>> s  # without print(), special characters are included in the string
     'First line.\nSecond line.'
     >>> print(s)  # with print(), special characters are interpreted, so \n produces new line
     First line.
     Second line.

Se non si desidera che i caratteri preceduti da ‘\’ siano interpretati
come caratteri speciali, è possibile utilizzare le cosiddette 'raw
strings' aggiungendo un ‘r’ prima del primo apice:

     >>> print('C:\some\name')  # here \n means newline!
     C:\some
     ame
     >>> print(r'C:\some\name')  # note the r before the quote
     C:\some\name

C’è un aspetto sottile nelle stringhe raw: una stringa raw non può
terminare con un numero dispari di caratteri ‘\’; vedi *note la voce
FAQ: 1fc7. per ulteriori informazioni e soluzioni.

String literals can span multiple lines.  One way is using
triple-quotes: ‘"""..."""’ or ‘'''...'''’.  End-of-line characters are
automatically included in the string, but it’s possible to prevent this
by adding a ‘\’ at the end of the line.  In the following example, the
initial newline is not included:

     >>> print("""\
     ... Usage: thingy [OPTIONS]
     ...      -h                        Display this usage message
     ...      -H hostname               Hostname to connect to
     ... """)
     Usage: thingy [OPTIONS]
          -h                        Display this usage message
          -H hostname               Hostname to connect to

     >>>

Le stringhe possono essere concatenate (incollate insieme) con
l’operatore ‘+’ e ripetute con ‘*’:

     >>> # 3 times 'un', followed by 'ium'
     >>> 3 * 'un' + 'ium'
     'unununium'

Due o più 'letterali di tipo stringa' (cioè quelli racchiusi tra
virgolette) posizionati uno accanto all’altro sono automaticamente
concatenati.

     >>> 'Py' 'thon'
     'Python'

Questa funzione è particolarmente utile quando si vogliono separare
stringhe lunghe:

     >>> text = ('Put several strings within parentheses '
     ...         'to have them joined together.')
     >>> text
     'Put several strings within parentheses to have them joined together.'

Questo funziona solo con due letterali, ma non con variabili o
'expression':

     >>> prefix = 'Py'
     >>> prefix 'thon'  # can't concatenate a variable and a string literal
       File "<stdin>", line 1
         prefix 'thon'
                ^^^^^^
     SyntaxError: invalid syntax
     >>> ('un' * 3) 'ium'
       File "<stdin>", line 1
         ('un' * 3) 'ium'
                    ^^^^^
     SyntaxError: invalid syntax

Se volete concatenare variabili o una variabile e un letterale, usate
‘+’:

     >>> prefix + 'thon'
     'Python'

Le stringhe possono essere 'indicizzate' (sottoscritte), e il primo
carattere ha indice 0.  Non esiste un tipo carattere specifico; un
carattere è semplicemente una stringa di dimensione uno:

     >>> word = 'Python'
     >>> word[0]  # character in position 0
     'P'
     >>> word[5]  # character in position 5
     'n'

Gli indici possono anche essere numeri negativi, per iniziare a contare
da destra:

     >>> word[-1]  # last character
     'n'
     >>> word[-2]  # second-last character
     'o'
     >>> word[-6]
     'P'

N.B. Poiché -0 è uguale a 0, gli indici negativi partono da -1.

Oltre all’indicizzazione, è supportato anche lo 'slicing'.  Mentre
l’indicizzazione è usata per ottenere i singoli caratteri, lo 'slicing'
permette di ottenere una sottostringa:

     >>> word[0:2]  # characters from position 0 (included) to 2 (excluded)
     'Py'
     >>> word[2:5]  # characters from position 2 (included) to 5 (excluded)
     'tho'

Nello slice gli indici hanno degli utili valori predefiniti; un primo
indice omesso è zero, un secondo indice omesso è uguale alla dimensione
della stringa che si sta tagliando:

     >>> word[:2]   # character from the beginning to position 2 (excluded)
     'Py'
     >>> word[4:]   # characters from position 4 (included) to the end
     'on'
     >>> word[-2:]  # characters from the second-last (included) to the end
     'on'

Si noti come l’inizio sia sempre incluso, e la fine sempre esclusa.
Questo fa sì che ‘s[:i] + s[i:]’ è sempre uguale a ‘s’:

     >>> word[:2] + word[2:]
     'Python'
     >>> word[:4] + word[4:]
     'Python'

Un modo per ricordare come funzionano le fette è quello di pensare agli
indici come al punto 'tra' caratteri, con il bordo sinistro del primo
carattere numerato 0.  Poi il bordo destro dell’ultimo carattere di una
stringa di caratteri 'n' ha l’indice 'n', per esempio:

      +---+---+---+---+---+---+
      | P | y | t | h | o | n |
      +---+---+---+---+---+---+
      0   1   2   3   4   5   6
     -6  -5  -4  -3  -2  -1

La prima riga di numeri dà la posizione degli indici 0…6 nella stringa;
la seconda riga dà i corrispondenti indici negativi.  La porzione da 'i'
a 'j' è costituita da tutti i caratteri tra i bordi contrassegnati
rispettivamente con 'i' e 'j'.

Per gli indici non negativi, la lunghezza di una fetta è la differenza
degli indici, se entrambi sono entro i limiti.  Per esempio, la
lunghezza di ‘word[1:3]’ è 2.

Il tentativo di utilizzare un indice troppo grande comporta un errore:

     >>> word[42]  # the word only has 6 characters
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     IndexError: string index out of range

Tuttavia, gli indici delle sottostringhe fuori 'range' (che superano la
lunghezza della stringa) sono gestiti a modo quando vengono utilizzati
per l’affettamento:

     >>> word[4:42]
     'on'
     >>> word[42:]
     ''

Le stringhe Python non possono essere modificate — sono *note immutable:
1fc8.  Pertanto, l’assegnazione di una posizione indicizzata nella
stringa comporta un errore:

     >>> word[0] = 'J'
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: 'str' object does not support item assignment
     >>> word[2:] = 'py'
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: 'str' object does not support item assignment

Se avete bisogno di una stringa diversa, dovreste crearne una nuova:

     >>> 'J' + word[1:]
     'Jython'
     >>> word[:2] + 'py'
     'Pypy'

La funzione integrata *note len(): 841. restituisce la lunghezza di una
stringa:

     >>> s = 'supercalifragilisticexpialidocious'
     >>> len(s)
     34

Vedi anche
..........

*note Tipo Sequenza di Testo — str: 1fc9.

     Le stringhe sono esempi di 'tipi di sequenze', e supportano le
     operazioni comuni supportate da questi tipi di dato.

*note Metodi per le Stringhe: 1fca.

     Un gran numero di metodi per le trasformazioni di base e la ricerca
     sono supportati dalle stringhe.

*note f-strings: 19a.

     Stringhe con 'expression' incorporate.

*note Format String Syntax: 15a3.

     Informazioni sulla formattazione delle stringhe con *note
     str.format(): 834.

*note Formattazione delle stringhe in stile printf: 8dc.

     Il vecchio metodo di formattazione, quello che prevede un template
     a sinistra dell’operatore ‘%’ è descritto più dettagliatamente qui.

   ---------- Footnotes ----------

   (1) A differenza di altri linguaggi, i caratteri speciali come ‘\n’
hanno lo stesso significato sia con apici singoli (‘’…’’) che doppi
(‘”…”’).  L’unica differenza tra i due è che all’interno delle stringhe
ad apici singoli non c’è bisogno di aggiungere il carattere di escaping
prima del ‘"’ (ma bisogna inserirlo prima di un ‘\'’) e viceversa.


File: python.info,  Node: Liste,  Prev: Testo,  Up: Usare Python come calcolatrice

2.3.1.3 Liste
.............

Python conosce un certo numero di tipi di dati 'composti', usati per
raggruppare altri valori.  La più versatile è la 'lista', che può essere
scritta come una lista di valori separati da virgola (elementi) tra
parentesi quadre.  Gli elenchi possono contenere elementi di tipo
diverso, ma di solito gli elementi hanno tutti lo stesso tipo.

     >>> squares = [1, 4, 9, 16, 25]
     >>> squares
     [1, 4, 9, 16, 25]

Come le stringhe (e tutti gli altri tipi built-in *note sequence: 717.),
le liste possono essere indicizzate e tagliate:

     >>> squares[0]  # indexing returns the item
     1
     >>> squares[-1]
     25
     >>> squares[-3:]  # slicing returns a new list
     [9, 16, 25]

Gli elenchi supportano anche operazioni come la concatenazione:

     >>> squares + [36, 49, 64, 81, 100]
     [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]

A differenza delle stringhe, che sono *note immutable: 1fc8, le liste
sono di tipo *note mutable: 1fcd, cioè è possibile modificarne il
contenuto:

     >>> cubes = [1, 8, 27, 65, 125]  # something's wrong here
     >>> 4 ** 3  # the cube of 4 is 64, not 65!
     64
     >>> cubes[3] = 64  # replace the wrong value
     >>> cubes
     [1, 8, 27, 64, 125]

You can also add new items at the end of the list, by using the *note
list.append(): 8dd. 'method' (we will see more about methods later):

     >>> cubes.append(216)  # add the cube of 6
     >>> cubes.append(7 ** 3)  # and the cube of 7
     >>> cubes
     [1, 8, 27, 64, 125, 216, 343]

L’assegnazione semplice in Python non copia mai i dati.  Quando assegni
una lista a una variabile, la variabile si riferisce alla 'lista
esistente'.  Qualsiasi modifica apportata alla lista tramite una
variabile sarà visibile attraverso tutte le altre variabili che si
riferiscono ad essa.:

     >>> rgb = ["Red", "Green", "Blue"]
     >>> rgba = rgb
     >>> id(rgb) == id(rgba)  # they reference the same object
     True
     >>> rgba.append("Alph")
     >>> rgb
     ["Red", "Green", "Blue", "Alph"]

Tutte le operazioni di taglio restituiscono una nuova lista contenente
gli elementi richiesti.  Ciò significa che la seguente sezione
restituisce una nuova *note shallow copy: 1fce. della list:

     >>> correct_rgba = rgba[:]
     >>> correct_rgba[-1] = "Alpha"
     >>> correct_rgba
     ["Red", "Green", "Blue", "Alpha"]
     >>> rgba
     ["Red", "Green", "Blue", "Alph"]

L’assegnazione a uno slice è anche possibile, per cambiare anche la
dimensione della lista o cancellarne gli elementi completamente:

     >>> letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g']
     >>> letters
     ['a', 'b', 'c', 'd', 'e', 'f', 'g']
     >>> # replace some values
     >>> letters[2:5] = ['C', 'D', 'E']
     >>> letters
     ['a', 'b', 'C', 'D', 'E', 'f', 'g']
     >>> # now remove them
     >>> letters[2:5] = []
     >>> letters
     ['a', 'b', 'f', 'g']
     >>> # clear the list by replacing all the elements with an empty list
     >>> letters[:] = []
     >>> letters
     []

La funzione *note len(): 841. si applica anche alle liste:

     >>> letters = ['a', 'b', 'c', 'd']
     >>> len(letters)
     4

E” possibile nidificare liste (creare liste contenenti altre liste), ad
esempio:

     >>> a = ['a', 'b', 'c']
     >>> n = [1, 2, 3]
     >>> x = [a, n]
     >>> x
     [['a', 'b', 'c'], [1, 2, 3]]
     >>> x[0]
     ['a', 'b', 'c']
     >>> x[0][1]
     'b'


File: python.info,  Node: Primi passi di programmazione,  Prev: Usare Python come calcolatrice,  Up: Un’introduzione informale a Python

2.3.2 Primi passi di programmazione
-----------------------------------

Naturalmente, possiamo usare Python per compiti più complicati che
sommare insieme due più due.  Per esempio, possiamo scrivere una prima
sottosequenza della Successione di Fibonacci(1) come segue:

     >>> # Fibonacci series:
     >>> # the sum of two elements defines the next
     >>> a, b = 0, 1
     >>> while a < 10:
     ...     print(a)
     ...     a, b = b, a+b
     ...
     0
     1
     1
     2
     3
     5
     8

Questo esempio introduce diverse nuove funzionalità.

   * La prima riga contiene una 'assegnazione multipla': le variabili
     ‘a’ e ‘b’ ottengono simultaneamente i nuovi valori 0 e 1.
     Sull’ultima riga viene usata di nuovo, dimostrando che le
     espressioni sul lato destro sono tutte valutate prima di una
     qualsiasi delle assegnazioni.  Le espressioni del lato destro sono
     valutate da sinistra a destra.

   * Il ciclo *note while: 195b. viene eseguito finché la condizione
     (qui: ‘a < 10’) rimane vera.  In Python, come in C, qualsiasi
     valore intero diverso da zero è vero; zero è falso.  La condizione
     può anche essere una stringa o un valore di lista, infatti
     qualsiasi sequenza; qualsiasi cosa con una lunghezza diversa da
     zero è vera, le sequenze vuote sono false.  Il test utilizzato
     nell’esempio è un semplice confronto.  Gli operatori di confronto
     standard sono scritti come in C: ‘<’ (minore di), ‘>’ (maggiore
     di), ‘==’ (uguale a), ‘<=’ (minore o uguale a), ‘>=’ (maggiore o
     uguale a) e ‘!=’ (diverso da).

   * Il 'corpo' del ciclo è 'indentato': l’indentazione è il modo di
     Python di raggruppare le istruzioni.  Al prompt interattivo, è
     necessario digitare un tab o spazio/i per ogni riga rientrata.  In
     pratica si prepara un input più complicato per Python con un editor
     di testo; tutti gli editor di testo seri hanno una funzione di
     auto-indentazione.  Quando un’istruzione composta è inserita nella
     shell interattiva, deve essere seguita da una riga vuota per
     indicare il completamento (poiché l’analizzatore non può indovinare
     quando si è digitata l’ultima riga).  Si noti che ogni riga
     all’interno di un blocco di base deve essere rientrata della stessa
     quantità.

   * The *note print(): 1177. function writes the value of the
     argument(s) it is given.  It differs from just writing the
     expression you want to write (as we did earlier in the calculator
     examples) in the way it handles multiple arguments, floating-point
     quantities, and strings.  Strings are printed without quotes, and a
     space is inserted between items, so you can format things nicely,
     like this:

          >>> i = 256*256
          >>> print('The value of i is', i)
          The value of i is 65536

     L’argomento 'end' può essere usato per evitare la nuova linea dopo
     l’output, o terminare l’output con una stringa diversa:

          >>> a, b = 0, 1
          >>> while a < 1000:
          ...     print(a, end=',')
          ...     a, b = b, a+b
          ...
          0,1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,

Note
....

   ---------- Footnotes ----------

   (1) https://it.wikipedia.org/wiki/Successione_di_Fibonacci


File: python.info,  Node: Altri Strumenti di Controllo del Flusso,  Next: Strutture Dati,  Prev: Un’introduzione informale a Python,  Up: Tutorial su Python

2.4 Altri Strumenti di Controllo del Flusso
===========================================

Oltre all’istruzione *note while: 195b. appena introdotta, Python ne
utilizza altre che incontreremo in questo capitolo.

* Menu:

* Istruzioni if::
* Istruzioni for::
* La Funzione range(): La Funzione range.
* break and continue Statements::
* else Clauses on Loops::
* Istruzioni pass::
* Istruzioni match::
* Definizione di Funzioni::
* Ulteriori informazioni sulla Definizione di Funzioni::
* Intermezzo; Stile di Codifica: Intermezzo Stile di Codifica.


File: python.info,  Node: Istruzioni if,  Next: Istruzioni for,  Up: Altri Strumenti di Controllo del Flusso

2.4.1 Istruzioni ‘if’
---------------------

Forse il tipo di istruzione più conosciuto è l’istruzione *note if: 181.
Ad esempio:

     >>> x = int(input("Please enter an integer: "))
     Please enter an integer: 42
     >>> if x < 0:
     ...     x = 0
     ...     print('Negative changed to zero')
     ... elif x == 0:
     ...     print('Zero')
     ... elif x == 1:
     ...     print('Single')
     ... else:
     ...     print('More')
     ...
     More

Possiamo avere zero o più parti *note elif: 17b, e la parte *note else:
17c. è facoltativa.  La parola chiave “‘elif’” è l’abbreviazione di
“else if”, ed è utile per evitare un’eccessiva indentazione.  Una
sequenza ‘if’ … ‘elif’ … ‘elif’ … è un sostituto per le istruzioni
‘switch’ o ‘case’ trovate in altri linguaggi.

Se stai confrontando lo stesso valore con diverse costanti, o
controllando tipi o attributi specifici, potresti trovare utile
l’istruzione ‘match’.  Per maggiori dettagli, consulta *note Istruzioni
match: 1fd7.


File: python.info,  Node: Istruzioni for,  Next: La Funzione range,  Prev: Istruzioni if,  Up: Altri Strumenti di Controllo del Flusso

2.4.2 Istruzioni ‘for’
----------------------

L’istruzione *note for: 34a. in Python differisce leggermente da ciò a
cui potresti essere abitualmente abituato in C o Pascal.  Piuttosto che
iterare sempre su una progressione aritmetica di numeri (come in
Pascal), o dare all’utente la possibilità di definire sia il passo di
iterazione che la condizione di arresto (come in C), l’istruzione ‘for’
di Python itera sugli elementi di qualsiasi sequenza (una lista o una
stringa), nell’ordine in cui appaiono nella sequenza.  Ad esempio:

     >>> # Measure some strings:
     >>> words = ['cat', 'window', 'defenestrate']
     >>> for w in words:
     ...     print(w, len(w))
     ...
     cat 3
     window 6
     defenestrate 12

Il codice che modifica una collezione durante l’iterazione sulla stessa
può essere difficile da scrivere correttamente.  Invece, è generalmente
più semplice iterare su una copia della collezione o crearne una nuova:

     # Create a sample collection
     users = {'Hans': 'active', 'Éléonore': 'inactive', '景太郎': 'active'}

     # Strategy:  Iterate over a copy
     for user, status in users.copy().items():
         if status == 'inactive':
             del users[user]

     # Strategy:  Create a new collection
     active_users = {}
     for user, status in users.items():
         if status == 'active':
             active_users[user] = status


File: python.info,  Node: La Funzione range,  Next: break and continue Statements,  Prev: Istruzioni for,  Up: Altri Strumenti di Controllo del Flusso

2.4.3 La Funzione ‘range()’
---------------------------

Se hai bisogno di iterare su una sequenza di numeri, la funzione
integrata *note range(): b3f. è utile.  Genera progressioni aritmetiche:

     >>> for i in range(5):
     ...     print(i)
     ...
     0
     1
     2
     3
     4

Il valore finale fornito non fa parte della sequenza generata;
‘range(10)’ genera 10 valori, gli indici legali per gli elementi di una
sequenza di lunghezza 10.  È possibile far partire l’intervallo da un
altro numero, o specificare un incremento diverso (anche negativo;
talvolta questo è chiamato “passo”):

     >>> list(range(5, 10))
     [5, 6, 7, 8, 9]

     >>> list(range(0, 10, 3))
     [0, 3, 6, 9]

     >>> list(range(-10, -100, -30))
     [-10, -40, -70]

Per iterare sugli indici di una sequenza, puoi combinare *note range():
b3f. e *note len(): 841. nel seguente modo:

     >>> a = ['Mary', 'had', 'a', 'little', 'lamb']
     >>> for i in range(len(a)):
     ...     print(i, a[i])
     ...
     0 Mary
     1 had
     2 a
     3 little
     4 lamb

Nella maggior parte di questi casi, però, è conveniente utilizzare la
funzione *note enumerate(): 1688, vedi *note Tecniche di Looping: 1fdc.

Attenzione: succede una cosa strana se provi a stampare un range:

     >>> range(10)
     range(0, 10)

In molti casi, l’oggetto restituito da *note range(): b3f. si comporta
come se fosse una lista, ma in realtà non lo è.  È un oggetto che
restituisce gli elementi successivi della sequenza desiderata quando ci
si itera sopra, ma non crea effettivamente la lista, risparmiando così
spazio.

Diciamo che un tale oggetto è un *note iterable: 142f, cioè adatto per
funzioni e costrutti che si aspettano qualcosa da cui possono ottenere
elementi fino a quando il contenitore è vuoto.  Abbiamo visto che
l’istruzione *note for: 34a. è un tale costrutto, mentre un esempio di
una funzione che prende come argomento un oggetto iterabile è *note
sum(): 696.:

     >>> sum(range(4))  # 0 + 1 + 2 + 3
     6

In seguito vedremo altre funzioni che restituiscono oggetti iterabili e
prendono oggetti iterabili come argomenti.  Nel capitolo *note Strutture
Dati: 1fdd, discuteremo in modo più dettagliato riguardo a *note list():
24d.


File: python.info,  Node: break and continue Statements,  Next: else Clauses on Loops,  Prev: La Funzione range,  Up: Altri Strumenti di Controllo del Flusso

2.4.4 ‘break’ and ‘continue’ Statements
---------------------------------------

The *note break: 17f. statement breaks out of the innermost enclosing
*note for: 34a. or *note while: 195b. loop:

     >>> for n in range(2, 10):
     ...     for x in range(2, n):
     ...         if n % x == 0:
     ...             print(f"{n} equals {x} * {n//x}")
     ...             break
     ...
     4 equals 2 * 2
     6 equals 2 * 3
     8 equals 2 * 4
     9 equals 3 * 3

The *note continue: 180. statement continues with the next iteration of
the loop:

     >>> for num in range(2, 10):
     ...     if num % 2 == 0:
     ...         print(f"Found an even number {num}")
     ...         continue
     ...     print(f"Found an odd number {num}")
     ...
     Found an even number 2
     Found an odd number 3
     Found an even number 4
     Found an odd number 5
     Found an even number 6
     Found an odd number 7
     Found an even number 8
     Found an odd number 9


File: python.info,  Node: else Clauses on Loops,  Next: Istruzioni pass,  Prev: break and continue Statements,  Up: Altri Strumenti di Controllo del Flusso

2.4.5 ‘else’ Clauses on Loops
-----------------------------

In a ‘for’ or ‘while’ loop the ‘break’ statement may be paired with an
‘else’ clause.  If the loop finishes without executing the ‘break’, the
‘else’ clause executes.

In a *note for: 34a. loop, the ‘else’ clause is executed after the loop
finishes its final iteration, that is, if no break occurred.

In un ciclo *note while: 195b, viene eseguita dopo che la condizione del
ciclo diventa falsa.

In either kind of loop, the ‘else’ clause is 'not' executed if the loop
was terminated by a *note break: 17f.  Of course, other ways of ending
the loop early, such as a *note return: 1af. or a raised exception, will
also skip execution of the *note else: 17c. clause.

Questo è esemplificato nel seguente ciclo ‘for’, che cerca numeri primi:

     >>> for n in range(2, 10):
     ...     for x in range(2, n):
     ...         if n % x == 0:
     ...             print(n, 'equals', x, '*', n//x)
     ...             break
     ...     else:
     ...         # loop fell through without finding a factor
     ...         print(n, 'is a prime number')
     ...
     2 is a prime number
     3 is a prime number
     4 equals 2 * 2
     5 is a prime number
     6 equals 2 * 3
     7 is a prime number
     8 equals 2 * 4
     9 equals 3 * 3

(Yes, this is the correct code.  Look closely: the ‘else’ clause belongs
to the ‘for’ loop, 'not' the ‘if’ statement.)

One way to think of the else clause is to imagine it paired with the
‘if’ inside the loop.  As the loop executes, it will run a sequence like
if/if/if/else.  The ‘if’ is inside the loop, encountered a number of
times.  If the condition is ever true, a ‘break’ will happen.  If the
condition is never true, the ‘else’ clause outside the loop will
execute.

When used with a loop, the ‘else’ clause has more in common with the
‘else’ clause of a *note try: 8f9. statement than it does with that of
‘if’ statements: a ‘try’ statement’s ‘else’ clause runs when no
exception occurs, and a loop’s ‘else’ clause runs when no ‘break’
occurs.  For more on the ‘try’ statement and exceptions, see *note
Gestione delle Eccezioni: 1fe3.


File: python.info,  Node: Istruzioni pass,  Next: Istruzioni match,  Prev: else Clauses on Loops,  Up: Altri Strumenti di Controllo del Flusso

2.4.6 Istruzioni ‘pass’
-----------------------

L’istruzione *note pass: 17e. non fa nulla.  Può essere utilizzata
quando è richiesta un’istruzione sintatticamente, ma il programma non
richiede alcuna azione.  Per esempio:

     >>> while True:
     ...     pass  # Busy-wait for keyboard interrupt (Ctrl+C)
     ...

Questo è comunemente usato per creare classi minime:

     >>> class MyEmptyClass:
     ...     pass
     ...

Un altro posto in cui *note pass: 17e. può essere usato è come
segnaposto per il corpo di una funzione o condizionale quando si sta
lavorando su nuovo codice, permettendo di continuare a pensare a un
livello più astratto.  L’istruzione ‘pass’ viene ignorata
silenziosamente:

     >>> def initlog(*args):
     ...     pass   # Remember to implement this!
     ...

For this last case, many people use the ellipsis literal ‘...’ instead
of ‘pass’.  This use has no special meaning to Python, and is not part
of the language definition (you could use any constant expression here),
but ‘...’ is used conventionally as a placeholder body as well.  See
*note L’Oggetto Ellipsis: 1fe6.


File: python.info,  Node: Istruzioni match,  Next: Definizione di Funzioni,  Prev: Istruzioni pass,  Up: Altri Strumenti di Controllo del Flusso

2.4.7 Istruzioni ‘match’
------------------------

A *note match: a10. statement takes an expression and compares its value
to successive patterns given as one or more case blocks.  This is
superficially similar to a switch statement in C, Java or JavaScript
(and many other languages), but it’s more similar to pattern matching in
languages like Rust or Haskell.  Only the first pattern that matches
gets executed and it can also extract components (sequence elements or
object attributes) from the value into variables.  If no case matches,
none of the branches is executed.

La forma più semplice confronta un valore con uno o più letterali:

     def http_error(status):
         match status:
             case 400:
                 return "Bad request"
             case 404:
                 return "Not found"
             case 418:
                 return "I'm a teapot"
             case _:
                 return "Something's wrong with the internet"

Note the last block: the «variable name» ‘_’ acts as a 'wildcard' and
never fails to match.

Puoi combinare diversi letterali in un singolo schema usando ‘|’ («or»):

     case 401 | 403 | 404:
         return "Not allowed"

Gli schemi possono sembrare assegnazioni di decomposizione e possono
essere utilizzati per associare variabili:

     # point is an (x, y) tuple
     match point:
         case (0, 0):
             print("Origin")
         case (0, y):
             print(f"Y={y}")
         case (x, 0):
             print(f"X={x}")
         case (x, y):
             print(f"X={x}, Y={y}")
         case _:
             raise ValueError("Not a point")

Studialo attentamente!  Il primo schema ha due letterali, e può essere
pensato come un’estensione dello schema letterale mostrato sopra.  Ma i
successivi due schemi combinano un letterale e una variabile, e la
variabile 'associa' un valore dal soggetto (‘point’).  Il quarto schema
cattura due valori, che lo rende concettualmente simile all’assegnazione
con 'unpacking' ‘(x, y) = point’.

Se stai utilizzando classi per strutturare i tuoi dati, puoi usare il
nome della classe seguito da un elenco di argomenti che assomiglia a un
costruttore, ma con la capacità di catturare attributi in variabili:

     class Point:
         def __init__(self, x, y):
             self.x = x
             self.y = y

     def where_is(point):
         match point:
             case Point(x=0, y=0):
                 print("Origin")
             case Point(x=0, y=y):
                 print(f"Y={y}")
             case Point(x=x, y=0):
                 print(f"X={x}")
             case Point():
                 print("Somewhere else")
             case _:
                 print("Not a point")

Puoi utilizzare parametri posizionali con alcune classi integrate che
forniscono un ordinamento per i loro attributi (ad esempio le
dataclassi).  Puoi anche definire una posizione specifica per gli
attributi negli schemi impostando l’attributo speciale ‘__match_args__’
nelle tue classi.  Se è impostato su («x», «y»), gli schemi seguenti
sono tutti equivalenti (e tutti associano l’attributo ‘y’ alla variabile
‘var’):

     Point(1, var)
     Point(1, y=var)
     Point(x=1, y=var)
     Point(y=var, x=1)

Un modo consigliato per leggere gli schemi è considerarli come una forma
estesa di quello che metteresti a sinistra di un’assegnazione, per
capire quali variabili verrebbero impostate su cosa.  Solo i nomi
autonomi (come ‘var’ qui sopra) vengono assegnati da un’istruzione di
match.  I nomi puntati (come ‘foo.bar’), i nomi degli attributi (il ‘x=’
e ‘y=’ qui sopra) o i nomi delle classi (riconosciuti dalle «(…)»
accanto a loro come ‘Point’ qui sopra) non vengono mai assegnati.

Gli schemi possono essere arbitrariamente nidificati.  Ad esempio, se
abbiamo una breve lista di Punti, con ‘__match_args__’ aggiunto,
potremmo abbinarla così:

     class Point:
         __match_args__ = ('x', 'y')
         def __init__(self, x, y):
             self.x = x
             self.y = y

     match points:
         case []:
             print("No points")
         case [Point(0, 0)]:
             print("The origin")
         case [Point(x, y)]:
             print(f"Single point {x}, {y}")
         case [Point(0, y1), Point(0, y2)]:
             print(f"Two on the Y axis at {y1}, {y2}")
         case _:
             print("Something else")

Possiamo aggiungere una clausola ‘if’ a uno schema, nota come «guardia».
Se la guardia è falsa, ‘match’ passa a provare il blocco case
successivo.  Nota che la cattura del valore avviene prima che la guardia
venga valutata:

     match point:
         case Point(x, y) if x == y:
             print(f"Y=X at {x}")
         case Point(x, y):
             print(f"Not on the diagonal")

Altre caratteristiche chiave di questa istruzione:

   - Come le assegnazioni di decomposizione, gli schemi di tuple e liste
     hanno esattamente lo stesso significato e corrispondono
     effettivamente a sequenze arbitrarie.  Un’importante eccezione è
     che non corrispondano a iteratori o stringhe.

   - Le sequenze di schemi supportano l’unpacking esteso: ‘[x, y,
     *rest]’ e ‘(x, y, *rest)’ funzionano in modo simile alle
     assegnazioni di decomposizione.  Il nome dopo ‘*’ può anche essere
     ‘_’, quindi ‘(x, y, *_)’ corrisponde a una sequenza di almeno due
     elementi senza la necessità di associare gli elementi rimanenti.

   - Schemi di mapping: ‘{"bandwidth": b, "latency": l}’ cattura i
     valori ‘"bandwidth"’ e ‘"latency"’ da un dizionario.  A differenza
     degli schemi di sequenza, le chiavi aggiuntive vengono ignorate.  È
     supportato anche un unpacking come ‘**rest’.  (Ma ‘**_’ sarebbe
     ridondante, quindi non è possibile utilizzarlo.)

   - I sotto-schemi possono essere catturati utilizzando la parola
     chiave ‘as’:

          case (Point(x1, y1), Point(x2, y2) as p2): ...

     acquisirà il secondo elemento dell’input come ‘p2’ (a patto che
     l’input sia una sequenza di due punti)

   - La maggior parte dei letterali sono confrontati per uguaglianza,
     tuttavia i 'singleton' ‘True’, ‘False’ e ‘None’ sono confrontati
     per identità.

   - Gli schemi possono utilizzare costanti nominate.  Queste devono
     essere nomi puntati per impedire che vengano interpretati come
     variabili di cattura:

          from enum import Enum
          class Color(Enum):
              RED = 'red'
              GREEN = 'green'
              BLUE = 'blue'

          color = Color(input("Enter your choice of 'red', 'blue' or 'green': "))

          match color:
              case Color.RED:
                  print("I see red!")
              case Color.GREEN:
                  print("Grass is green")
              case Color.BLUE:
                  print("I'm feeling the blues :(")

Per una spiegazione più dettagliata e ulteriori esempi, puoi consultare
PEP 636(1) che è scritta in un formato simile a un tutorial.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0636/


File: python.info,  Node: Definizione di Funzioni,  Next: Ulteriori informazioni sulla Definizione di Funzioni,  Prev: Istruzioni match,  Up: Altri Strumenti di Controllo del Flusso

2.4.8 Definizione di Funzioni
-----------------------------

Possiamo creare una funzione che scrive la serie di Fibonacci fino a un
limite arbitrario:

     >>> def fib(n):    # write Fibonacci series less than n
     ...     """Print a Fibonacci series less than n."""
     ...     a, b = 0, 1
     ...     while a < n:
     ...         print(a, end=' ')
     ...         a, b = b, a+b
     ...     print()
     ...
     >>> # Now call the function we just defined:
     >>> fib(2000)
     0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597

La parola chiave *note def: 1661. introduce una 'definizione' di
funzione.  Deve essere seguita dal nome della funzione e dall’elenco tra
parentesi dei parametri formali.  Le istruzioni che formano il corpo
della funzione iniziano alla riga successiva, e devono essere indentate.

La prima istruzione del corpo della funzione può opzionalmente essere
una stringa letterale; questa stringa letterale è la stringa di
documentazione della funzione, o 'docstring'.  (Maggiori informazioni
sulle docstring possono essere trovate nella sezione *note Stringhe di
Documentazione: 1fea.)  Ci sono strumenti che utilizzano le docstring
per produrre automaticamente documentazione online o stampata, o per
consentire all’utente di navigare interattivamente attraverso il codice;
è una buona pratica includere le docstring nel codice che scrivi, quindi
prendilo come abitudine.

L”'esecuzione' di una funzione introduce una nuova tabella dei simboli
utilizzata per le variabili locali della funzione.  Più precisamente,
tutte le assegnazioni di variabili in una funzione memorizzano il valore
nella tabella dei simboli locali; mentre i riferimenti alle variabili
cercano prima nella tabella dei simboli locali, poi nelle tabelle dei
simboli locali delle funzioni circostanti, poi nella tabella dei simboli
globali, e infine nella tabella dei nomi incorporati.  Pertanto, le
variabili globali e le variabili delle funzioni circostanti non possono
essere direttamente assegnate un valore all’interno di una funzione (a
meno che, per le variabili globali, siano nominate in un’istruzione
*note global: 4ad, o, per le variabili delle funzioni circostanti, siano
nominate in un’istruzione *note nonlocal: 14af.), anche se possono
essere referenziate.

I parametri effettivi (argomenti) di una chiamata di funzione vengono
introdotti nella tabella dei simboli locali della funzione chiamata
quando viene chiamata; quindi, gli argomenti sono passati utilizzando il
'passaggio per valore' (dove il 'valore' è sempre un 'riferimento'
all’oggetto, non il valore dell’oggetto).  (1)  Quando una funzione
chiama un’altra funzione, o si chiama ricorsivamente, viene creata una
nuova tabella dei simboli locali per quella chiamata.

Una definizione di funzione associa il nome della funzione all’oggetto
funzione nella tabella dei simboli corrente.  L’interprete riconosce
l’oggetto puntato da quel nome come una funzione definita dall’utente.
Altri nomi possono anche puntare a quello stesso oggetto funzione e
possono anche essere utilizzati per accedere alla funzione:

     >>> fib
     <function fib at 10042ed0>
     >>> f = fib
     >>> f(100)
     0 1 1 2 3 5 8 13 21 34 55 89

Provenendo da altri linguaggi, potresti obiettare che ‘fib’ non è una
funzione ma una procedura poiché non restituisce un valore.  Infatti,
anche le funzioni senza un’istruzione *note return: 1af. restituiscono
un valore, sebbene piuttosto noioso.  Questo valore si chiama ‘None’ (è
un nome riservato del linguaggio).  Scrivere il valore ‘None’ è
normalmente soppresso dall’interprete se sarebbe l’unico valore scritto.
Puoi vederlo se lo desideri davvero utilizzando *note print(): 1177.:

     >>> fib(0)
     >>> print(fib(0))
     None

È semplice scrivere una funzione che restituisce una lista dei numeri
della serie di Fibonacci, invece di stamparla:

     >>> def fib2(n):  # return Fibonacci series up to n
     ...     """Return a list containing the Fibonacci series up to n."""
     ...     result = []
     ...     a, b = 0, 1
     ...     while a < n:
     ...         result.append(a)    # see below
     ...         a, b = b, a+b
     ...     return result
     ...
     >>> f100 = fib2(100)    # call it
     >>> f100                # write the result
     [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]

Questo esempio, come al solito, dimostra alcune nuove funzionalità di
Python:

   * L’istruzione *note return: 1af. restituisce un valore da una
     funzione.  ‘return’ senza un argomento espressione restituisce
     ‘None’.  Anche uscire dalla fine di una funzione restituisce
     ‘None’.

   * The statement ‘result.append(a)’ calls a 'method' of the list
     object ‘result’.  A method is a function that “belongs” to an
     object and is named ‘obj.methodname’, where ‘obj’ is some object
     (this may be an expression), and ‘methodname’ is the name of a
     method that is defined by the object’s type.  Different types
     define different methods.  Methods of different types may have the
     same name without causing ambiguity.  (It is possible to define
     your own object types and methods, using 'classes', see *note
     Classi: 1feb.) The method *note append(): 8dd. shown in the example
     is defined for list objects; it adds a new element at the end of
     the list.  In this example it is equivalent to ‘result = result +
     [a]’, but more efficient.

   ---------- Footnotes ----------

   (1) In realtà, 'chiamata per riferimento all’oggetto' sarebbe una
descrizione migliore, poiché se viene passato un oggetto mutabile, il
chiamante vedrà qualsiasi modifica che il chiamato fa ad esso (elementi
inseriti in una lista).


File: python.info,  Node: Ulteriori informazioni sulla Definizione di Funzioni,  Next: Intermezzo Stile di Codifica,  Prev: Definizione di Funzioni,  Up: Altri Strumenti di Controllo del Flusso

2.4.9 Ulteriori informazioni sulla Definizione di Funzioni
----------------------------------------------------------

È anche possibile definire funzioni con un numero variabile di
argomenti.  Esistono tre forme, che possono essere combinate.

* Menu:

* Valori predefiniti degli argomenti::
* Argomenti chiave-valore::
* Parametri speciali::
* Liste di Argomenti Arbitrarie::
* Spacchettamento delle Liste di Argomenti::
* Espressioni Lambda::
* Stringhe di Documentazione::
* Annotationi delle Funzioni::


File: python.info,  Node: Valori predefiniti degli argomenti,  Next: Argomenti chiave-valore,  Up: Ulteriori informazioni sulla Definizione di Funzioni

2.4.9.1 Valori predefiniti degli argomenti
..........................................

La forma più utile è specificare un valore predefinito per uno o più
argomenti.  Questo crea una funzione che può essere chiamata con meno
argomenti di quelli che è definita per consentire.  Ad esempio:

     def ask_ok(prompt, retries=4, reminder='Please try again!'):
         while True:
             reply = input(prompt)
             if reply in {'y', 'ye', 'yes'}:
                 return True
             if reply in {'n', 'no', 'nop', 'nope'}:
                 return False
             retries = retries - 1
             if retries < 0:
                 raise ValueError('invalid user response')
             print(reminder)

Questa funzione può essere chiamata in diversi modi:

   * dando solo l’argomento obbligatorio: ‘ask_ok('Vuoi davvero
     uscire?')’

   * dando uno degli argomenti opzionali: ‘ask_ok('OK sovrascrivere il
     file?', 2)’

   * o addirittura dando tutti gli argomenti: ‘ask_ok('OK sovrascrivere
     il file?', 2, 'Dai su, solo sì o no!')’

Questo esempio introduce anche la parola chiave *note in: 34b.  Questo
testa se una sequenza contiene o meno un certo valore.

I valori predefiniti vengono valutati nel punto di definizione della
funzione nello 'scope' di definizione, in modo che

     i = 5

     def f(arg=i):
         print(arg)

     i = 6
     f()

stamperà ‘5’.

'Avvertenza importante:' Il valore predefinito viene valutato solo una
volta.  Questo fa la differenza quando il valore predefinito è un
oggetto mutabile come una lista, un dizionario, o istanze della maggior
parte delle classi.  Ad esempio, la seguente funzione accumula gli
argomenti passati ad essa nelle chiamate successive:

     def f(a, L=[]):
         L.append(a)
         return L

     print(f(1))
     print(f(2))
     print(f(3))

Questo stamperà

     [1]
     [1, 2]
     [1, 2, 3]

Se non vuoi che il valore predefinito sia condiviso tra le chiamate
successive, puoi scrivere la funzione in questo modo:

     def f(a, L=None):
         if L is None:
             L = []
         L.append(a)
         return L


File: python.info,  Node: Argomenti chiave-valore,  Next: Parametri speciali,  Prev: Valori predefiniti degli argomenti,  Up: Ulteriori informazioni sulla Definizione di Funzioni

2.4.9.2 Argomenti chiave-valore
...............................

Le funzioni possono anche essere chiamate utilizzando *note argomenti
chiave-valore: f10. della forma ‘kwarg=value’.  Ad esempio, la seguente
funzione:

     def parrot(voltage, state='a stiff', action='voom', type='Norwegian Blue'):
         print("-- This parrot wouldn't", action, end=' ')
         print("if you put", voltage, "volts through it.")
         print("-- Lovely plumage, the", type)
         print("-- It's", state, "!")

accetta un argomento obbligatorio (‘voltage’) e tre argomenti opzionali
(‘state’, ‘action’, e ‘type’).  Questa funzione può essere chiamata in
uno dei seguenti modi:

     parrot(1000)                                          # 1 positional argument
     parrot(voltage=1000)                                  # 1 keyword argument
     parrot(voltage=1000000, action='VOOOOOM')             # 2 keyword arguments
     parrot(action='VOOOOOM', voltage=1000000)             # 2 keyword arguments
     parrot('a million', 'bereft of life', 'jump')         # 3 positional arguments
     parrot('a thousand', state='pushing up the daisies')  # 1 positional, 1 keyword

ma tutte le chiamate seguenti non sarebbero valide:

     parrot()                     # required argument missing
     parrot(voltage=5.0, 'dead')  # non-keyword argument after a keyword argument
     parrot(110, voltage=220)     # duplicate value for the same argument
     parrot(actor='John Cleese')  # unknown keyword argument

In una chiamata di funzione, gli argomenti chiave-valore devono seguire
gli argomenti posizionali.  Tutti gli argomenti chiave passati devono
corrispondere a uno degli argomenti accettati dalla funzione (ad
esempio, ‘actor’ non è un argomento valido per la funzione ‘parrot’), e
il loro ordine non è importante.  Questo include anche gli argomenti non
opzionali (ad esempio, ‘parrot(voltage=1000)’ è valido).  Nessun
argomento può ricevere un valore più di una volta.  Ecco un esempio che
fallisce a causa di questa restrizione:

     >>> def function(a):
     ...     pass
     ...
     >>> function(0, a=0)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: function() got multiple values for argument 'a'

Quando è presente un parametro formale finale della forma ‘**name’,
riceve un dizionario (vedi *note Tipi di Mapping — dict: cbf.)
contenente tutti gli argomenti chiave tranne quelli corrispondenti a un
parametro formale.  Questo può essere combinato con un parametro formale
della forma ‘*name’ (descritto nella prossima sottosezione) che riceve
una *note tupla: 1ff2. contenente gli argomenti posizionali oltre
all’elenco dei parametri formali.  (‘*name’ deve occorrere prima di
‘**name’.)  Ad esempio, se definiamo una funzione in questo modo:

     def cheeseshop(kind, *arguments, **keywords):
         print("-- Do you have any", kind, "?")
         print("-- I'm sorry, we're all out of", kind)
         for arg in arguments:
             print(arg)
         print("-" * 40)
         for kw in keywords:
             print(kw, ":", keywords[kw])

Potrebbe essere chiamato in questo modo:

     cheeseshop("Limburger", "It's very runny, sir.",
                "It's really very, VERY runny, sir.",
                shopkeeper="Michael Palin",
                client="John Cleese",
                sketch="Cheese Shop Sketch")

e naturalmente stamperà:

     -- Do you have any Limburger ?
     -- I'm sorry, we're all out of Limburger
     It's very runny, sir.
     It's really very, VERY runny, sir.
     ----------------------------------------
     shopkeeper : Michael Palin
     client : John Cleese
     sketch : Cheese Shop Sketch

Nota che l’ordine in cui gli argomenti chiave-valore vengono stampati è
garantito corrispondere all’ordine in cui sono stati forniti nella
chiamata della funzione.


File: python.info,  Node: Parametri speciali,  Next: Liste di Argomenti Arbitrarie,  Prev: Argomenti chiave-valore,  Up: Ulteriori informazioni sulla Definizione di Funzioni

2.4.9.3 Parametri speciali
..........................

Per impostazione predefinita, gli argomenti possono essere passati a una
funzione Python sia per posizione che esplicitamente per chiave.  Per
leggibilità e prestazioni, ha senso limitare il modo in cui gli
argomenti possono essere passati in modo che uno sviluppatore debba solo
guardare la definizione della funzione per determinare se gli elementi
sono passati per posizione, per posizione o per chiave, o per chiave.

Ecco come potrebbe essere la definizione di una funzione:

     def f(pos1, pos2, /, pos_or_kwd, *, kwd1, kwd2):
           -----------    ----------     ----------
             |             |                  |
             |        Positional or keyword   |
             |                                - Keyword only
              -- Positional only

dove ‘/’ e ‘*’ sono opzionali.  Se utilizzati, questi simboli indicano
il tipo di parametro in base a come gli argomenti possono essere passati
alla funzione: solo per posizione, per posizione o per chiave, e solo
per chiave.  I parametri chiave-valore sono anche chiamati parametri
nominali.

* Menu:

* Argomenti Posizionali o per Chiave::
* Parametri Solo per Posizione::
* Argomenti Solo per Chiave::
* Esempi di Funzioni::
* Riepilogo::


File: python.info,  Node: Argomenti Posizionali o per Chiave,  Next: Parametri Solo per Posizione,  Up: Parametri speciali

2.4.9.4 Argomenti Posizionali o per Chiave
..........................................

Se ‘/’ e ‘*’ non sono presenti nella definizione della funzione, gli
argomenti possono essere passati a una funzione per posizione o per
chiave.


File: python.info,  Node: Parametri Solo per Posizione,  Next: Argomenti Solo per Chiave,  Prev: Argomenti Posizionali o per Chiave,  Up: Parametri speciali

2.4.9.5 Parametri Solo per Posizione
....................................

Guardando questo in modo più dettagliato, è possibile contrassegnare
certi parametri come 'solo per posizione'.  Se lo sono, l’ordine dei
parametri è importante, e i parametri non possono essere passati per
chiave.  I parametri solo per posizione sono posizionati prima di un ‘/’
(barra obliqua).  Il ‘/’ è utilizzato per separare logicamente i
parametri posizionali dal resto dei parametri.  Se non c’è un ‘/’ nella
definizione della funzione, non ci sono parametri posizionali.

I parametri che seguono il ‘/’ possono essere 'posizionali o per chiave'
o 'solo per chiave'.


File: python.info,  Node: Argomenti Solo per Chiave,  Next: Esempi di Funzioni,  Prev: Parametri Solo per Posizione,  Up: Parametri speciali

2.4.9.6 Argomenti Solo per Chiave
.................................

Per contrassegnare i parametri come 'solo per chiave', indicando che i
parametri devono essere passati per argomento chiave, posiziona un ‘*’
nell’elenco degli argomenti subito prima del primo parametro 'solo per
chiave'.


File: python.info,  Node: Esempi di Funzioni,  Next: Riepilogo,  Prev: Argomenti Solo per Chiave,  Up: Parametri speciali

2.4.9.7 Esempi di Funzioni
..........................

Considera le seguenti definizioni di funzioni di esempio prestando
particolare attenzione ai marcatori ‘/’ e ‘*’:

     >>> def standard_arg(arg):
     ...     print(arg)
     ...
     >>> def pos_only_arg(arg, /):
     ...     print(arg)
     ...
     >>> def kwd_only_arg(*, arg):
     ...     print(arg)
     ...
     >>> def combined_example(pos_only, /, standard, *, kwd_only):
     ...     print(pos_only, standard, kwd_only)

Nella prima definizione di funzione, ‘standard_arg’, la forma più
familiare, non pone restrizioni sulla convenzione di chiamata e gli
argomenti possono essere passati per posizione o per chiave:

     >>> standard_arg(2)
     2

     >>> standard_arg(arg=2)
     2

La seconda funzione ‘pos_only_arg’ è limitata a utilizzare solo
parametri posizionali poiché c’è un ‘/’ nella definizione della
funzione:

     >>> pos_only_arg(1)
     1

     >>> pos_only_arg(arg=1)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: pos_only_arg() got some positional-only arguments passed as keyword arguments: 'arg'

The third function ‘kwd_only_arg’ only allows keyword arguments as
indicated by a ‘*’ in the function definition:

     >>> kwd_only_arg(3)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: kwd_only_arg() takes 0 positional arguments but 1 was given

     >>> kwd_only_arg(arg=3)
     3

E l’ultimo utilizza tutte e tre le convenzioni di chiamata nella stessa
definizione di funzione:

     >>> combined_example(1, 2, 3)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: combined_example() takes 2 positional arguments but 3 were given

     >>> combined_example(1, 2, kwd_only=3)
     1 2 3

     >>> combined_example(1, standard=2, kwd_only=3)
     1 2 3

     >>> combined_example(pos_only=1, standard=2, kwd_only=3)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: combined_example() got some positional-only arguments passed as keyword arguments: 'pos_only'

Infine, considera questa definizione di funzione che ha un potenziale
conflitto tra l’argomento posizionale ‘name’ e ‘**kwds’ che ha ‘name’
come chiave:

     def foo(name, **kwds):
         return 'name' in kwds

Non esiste una chiamata possibile che lo farà restituire ‘True’ poiché
la chiave ‘'name'’ si legherà sempre al primo parametro.  Ad esempio:

     >>> foo(1, **{'name': 2})
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: foo() got multiple values for argument 'name'
     >>>

Ma utilizzando ‘/’ (argomenti solo per posizione), è possibile poiché
consente ‘name’ come argomento posizionale e ‘'name'’ come chiave negli
argomenti chiave-valore:

     >>> def foo(name, /, **kwds):
     ...     return 'name' in kwds
     ...
     >>> foo(1, **{'name': 2})
     True

In altre parole, i nomi dei parametri solo per posizione possono essere
utilizzati in ‘**kwds’ senza ambiguità.


File: python.info,  Node: Riepilogo,  Prev: Esempi di Funzioni,  Up: Parametri speciali

2.4.9.8 Riepilogo
.................

Il caso d’uso determinerà quali parametri utilizzare nella definizione
della funzione:

     def f(pos1, pos2, /, pos_or_kwd, *, kwd1, kwd2):

Come guida:

   * Usa solo argomenti per posizione se vuoi che il nome dei parametri
     non sia disponibile per l’utente.  Questo è utile quando i nomi dei
     parametri non hanno un vero significato, se vuoi imporre l’ordine
     degli argomenti quando la funzione viene chiamata o se devi
     prendere alcuni parametri posizionali e argomenti chiave arbitrari.

   * Usa solo argomenti per chiave quando i nomi hanno significato e la
     definizione della funzione è più comprensibile essendo esplicita
     con i nomi o vuoi impedire agli utenti di fare affidamento sulla
     posizione dell’argomento passato.

   * Per un’API, usa solo per posizione per evitare rotture delle
     modifiche API se il nome del parametro viene modificato in futuro.


File: python.info,  Node: Liste di Argomenti Arbitrarie,  Next: Spacchettamento delle Liste di Argomenti,  Prev: Parametri speciali,  Up: Ulteriori informazioni sulla Definizione di Funzioni

2.4.9.9 Liste di Argomenti Arbitrarie
.....................................

Infine, l’opzione meno utilizzata è specificare che una funzione può
essere chiamata con un numero arbitrario di argomenti.  Questi argomenti
saranno racchiusi in una tupla (vedi *note Tuple e Sequenze: 1ff2.).
Prima del numero variabile di argomenti, possono verificarsi zero o più
argomenti normali.

     def write_multiple_items(file, separator, *args):
         file.write(separator.join(args))

Normalmente, questi argomenti 'variadici' saranno gli ultimi nell’elenco
dei parametri formali, perché raccolgono tutti gli argomenti di input
rimanenti che vengono passati alla funzione.  Qualsiasi parametro
formale che si verifica dopo il parametro ‘*args’ sono argomenti “solo
per chiave”, il che significa che possono essere utilizzati solo come
argomenti chiave piuttosto che argomenti posizionali.

     >>> def concat(*args, sep="/"):
     ...     return sep.join(args)
     ...
     >>> concat("earth", "mars", "venus")
     'earth/mars/venus'
     >>> concat("earth", "mars", "venus", sep=".")
     'earth.mars.venus'


File: python.info,  Node: Spacchettamento delle Liste di Argomenti,  Next: Espressioni Lambda,  Prev: Liste di Argomenti Arbitrarie,  Up: Ulteriori informazioni sulla Definizione di Funzioni

2.4.9.10 Spacchettamento delle Liste di Argomenti
.................................................

La situazione inversa si verifica quando gli argomenti sono già in una
lista o tupla ma devono essere spacchettati per una chiamata di funzione
che richiede argomenti posizionali separati.  Ad esempio, la funzione
built-in *note range(): b3f. si aspetta argomenti 'start' e 'stop'
separati.  Se non sono disponibili separatamente, scrivi la chiamata di
funzione con l’operatore ‘*’per spacchettare gli argomenti da una lista
o tupla:

     >>> list(range(3, 6))            # normal call with separate arguments
     [3, 4, 5]
     >>> args = [3, 6]
     >>> list(range(*args))            # call with arguments unpacked from a list
     [3, 4, 5]

Nello stesso modo, i dizionari possono fornire argomenti chiave-valore
con l’operatore ‘**’::

     >>> def parrot(voltage, state='a stiff', action='voom'):
     ...     print("-- This parrot wouldn't", action, end=' ')
     ...     print("if you put", voltage, "volts through it.", end=' ')
     ...     print("E's", state, "!")
     ...
     >>> d = {"voltage": "four million", "state": "bleedin' demised", "action": "VOOM"}
     >>> parrot(**d)
     -- This parrot wouldn't VOOM if you put four million volts through it. E's bleedin' demised !


File: python.info,  Node: Espressioni Lambda,  Next: Stringhe di Documentazione,  Prev: Spacchettamento delle Liste di Argomenti,  Up: Ulteriori informazioni sulla Definizione di Funzioni

2.4.9.11 Espressioni Lambda
...........................

Piccole funzioni anonime possono essere create con la parola chiave
*note lambda: 14a5.  Questa funzione restituisce la somma dei suoi due
argomenti: ‘lambda a, b: a+b’.  Le funzioni lambda possono essere
utilizzate ovunque siano richiesti oggetti funzione.  Sono
sintatticamente limitate a una singola espressione.  Semanticamente,
sono solo zucchero sintattico per una normale definizione di funzione.
Come le definizioni di funzione nidificate, le funzioni lambda possono
fare riferimento a variabili dallo scope contenente:

     >>> def make_incrementor(n):
     ...     return lambda x: x + n
     ...
     >>> f = make_incrementor(42)
     >>> f(0)
     42
     >>> f(1)
     43

The above example uses a lambda expression to return a function.
Another use is to pass a small function as an argument.  For instance,
*note list.sort(): dca. takes a sorting key function 'key' which can be
a lambda function:

     >>> pairs = [(1, 'one'), (2, 'two'), (3, 'three'), (4, 'four')]
     >>> pairs.sort(key=lambda pair: pair[1])
     >>> pairs
     [(4, 'four'), (1, 'one'), (3, 'three'), (2, 'two')]


File: python.info,  Node: Stringhe di Documentazione,  Next: Annotationi delle Funzioni,  Prev: Espressioni Lambda,  Up: Ulteriori informazioni sulla Definizione di Funzioni

2.4.9.12 Stringhe di Documentazione
...................................

Ecco alcune convenzioni sul contenuto e la formattazione delle stringhe
di documentazione.

La prima riga dovrebbe essere sempre un breve e conciso riassunto dello
scopo dell’oggetto.  Per brevità, non dovrebbe esplicitamente indicare
il nome o il tipo dell’oggetto, poiché questi sono disponibili in altri
modi (tranne se il nome è un verbo che descrive l’operazione di una
funzione).  Questa riga dovrebbe iniziare con una lettera maiuscola e
terminare con un punto.

Se ci sono più righe nella stringa di documentazione, la seconda riga
dovrebbe essere vuota, separando visivamente il riassunto dal resto
della descrizione.  Le righe seguenti dovrebbero essere uno o più
paragrafi che descrivono le convenzioni di chiamata dell’oggetto, i suoi
effetti collaterali, ecc.

The Python parser strips indentation from multi-line string literals
when they serve as module, class, or function docstrings.

Di seguito è riportato un esempio di una stringa di documentazione
multilinea:

     >>> def my_function():
     ...     """Do nothing, but document it.
     ...
     ...     No, really, it doesn't do anything:
     ...
     ...         >>> my_function()
     ...         >>>
     ...     """
     ...     pass
     ...
     >>> print(my_function.__doc__)
     Do nothing, but document it.

     No, really, it doesn't do anything:

         >>> my_function()
         >>>


File: python.info,  Node: Annotationi delle Funzioni,  Prev: Stringhe di Documentazione,  Up: Ulteriori informazioni sulla Definizione di Funzioni

2.4.9.13 Annotationi delle Funzioni
...................................

*note Le annotationi delle funzioni: 2002. sono informazioni di metadati
completamente opzionali sui tipi utilizzati dalle funzioni definite
dall’utente (vedi PEP 3107(1) e PEP 484(2) per ulteriori informazioni).

*note Annotations: 2003. are stored in the *note __annotations__: 458.
attribute of the function as a dictionary and have no effect on any
other part of the function.  Parameter annotations are defined by a
colon after the parameter name, followed by an expression evaluating to
the value of the annotation.  Return annotations are defined by a
literal ‘->’, followed by an expression, between the parameter list and
the colon denoting the end of the *note def: 1661. statement.  The
following example has a required argument, an optional argument, and the
return value annotated:

     >>> def f(ham: str, eggs: str = 'eggs') -> str:
     ...     print("Annotations:", f.__annotations__)
     ...     print("Arguments:", ham, eggs)
     ...     return ham + ' and ' + eggs
     ...
     >>> f('spam')
     Annotations: {'ham': <class 'str'>, 'return': <class 'str'>, 'eggs': <class 'str'>}
     Arguments: spam eggs
     'spam and eggs'

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3107/

   (2) https://peps.python.org/pep-0484/


File: python.info,  Node: Intermezzo Stile di Codifica,  Prev: Ulteriori informazioni sulla Definizione di Funzioni,  Up: Altri Strumenti di Controllo del Flusso

2.4.10 Intermezzo: Stile di Codifica
------------------------------------

Ora che stai per scrivere pezzi di Python più lunghi e complessi, è un
buon momento per parlare dello 'stile di codifica'.  La maggior parte
dei linguaggi può essere scritta (o più concisamente, 'formattata') in
stili diversi; alcuni sono più leggibili di altri.  Rendere facile per
gli altri leggere il tuo codice è sempre una buona idea, e adottare uno
stile di codifica piacevole aiuta enormemente.

Per Python, la PEP 8(1) è la guida di stile a cui aderiscono la maggior
parte dei progetti; promuove uno stile di codifica molto leggibile e
piacevole alla vista.  Ogni sviluppatore Python dovrebbe leggerla prima
o poi; ecco i punti più importanti estratti per te:

   * Usa l’indentazione a 4 spazi, e niente tabulazioni.

     4 spazi sono un buon compromesso tra una piccola indentazione
     (permette una maggiore profondità di nidificazione) e una grande
     indentazione (più facile da leggere).  Le tabulazioni introducono
     confusione, ed è preferibile non usarle.

   * Manda a capo le righe in modo che non superino i 79 caratteri.

     Questo aiuta gli utenti con schermi piccoli e rende possibile avere
     diversi file di codice affiancati su schermi più grandi.

   * Usa righe vuote per separare funzioni e classi, e blocchi di codice
     più grandi all’interno delle funzioni.

   * Quando possibile, metti i commenti su una riga a parte.

   * Usa le stringhe di documentazione.

   * Usa spazi attorno agli operatori e dopo le virgole, ma non
     direttamente all’interno dei costrutti tra parentesi: ‘a = f(1, 2)
     + g(3, 4)’.

   * Nomina le tue classi e funzioni in modo coerente; la convenzione è
     utilizzare ‘UpperCamelCase’ per le classi e
     ‘lowercase_with_underscores’ per le funzioni e i metodi.  Usa
     sempre ‘self’ come nome per il primo argomento del metodo (vedi
     *note Una prima occhiata alle classi: 2006. per ulteriori
     informazioni su classi e metodi).

   * Non utilizzare codifiche complesse se il tuo codice è destinato ad
     essere utilizzato in ambienti internazionali.  Il predefinito di
     Python, UTF-8, o anche il semplice ASCII funzionano meglio in ogni
     caso.

   * Allo stesso modo, non utilizzare caratteri non-ASCII negli
     identificatori se c’è solo la minima possibilità che persone che
     parlano una lingua diversa leggano o mantengano il codice.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0008/


File: python.info,  Node: Strutture Dati,  Next: Moduli,  Prev: Altri Strumenti di Controllo del Flusso,  Up: Tutorial su Python

2.5 Strutture Dati
==================

Questo capitolo descrive alcune cose che hai già imparato in maggiore
dettaglio, e aggiunge anche alcune nuove cose.

* Menu:

* Più sulle Liste::
* L’istruzione del::
* Tuple e Sequenze::
* Insiemi::
* Dizionari::
* Tecniche di Looping::
* Maggiori informazioni sulle Condizioni::
* Confronto tra Sequenze e Altri Tipi::


File: python.info,  Node: Più sulle Liste,  Next: L’istruzione del,  Up: Strutture Dati

2.5.1 Più sulle Liste
---------------------

The *note list: 200c. data type has some more methods.  Here are all of
the methods of list objects:

 -- Metodo: list.append (x)

     Add an item to the end of the list.  Similar to ‘a[len(a):] = [x]’.

 -- Metodo: list.extend (iterable)

     Extend the list by appending all the items from the iterable.
     Similar to ‘a[len(a):] = iterable’.

 -- Metodo: list.insert (i, x)

     Inserisce un elemento in una posizione specificata.  Il primo
     argomento è l’indice dell’elemento prima del quale inserire, quindi
     ‘a.insert(0, x)’ inserisce all’inizio della lista, e
     ‘a.insert(len(a), x)’ è equivalente a ‘a.append(x)’.

 -- Metodo: list.remove (x)

     Rimuove il primo elemento dalla lista il cui valore è uguale a 'x'.
     Solleva una *note ValueError: 2ec. se non c’è un tale elemento.

 -- Metodo: list.pop ([i])

     Rimuove l’elemento nella posizione specificata nella lista e lo
     restituisce.  Se non viene specificato un indice, ‘a.pop()’ rimuove
     e restituisce l’ultimo elemento della lista.  Solleva un *note
     IndexError: 173c. se la lista è vuota o l’indice è fuori dal range
     della lista.

 -- Metodo: list.clear ()

     Remove all items from the list.  Similar to ‘del a[:]’.

 -- Metodo: list.index (x[, start[, end]])

     Return zero-based index of the first occurrence of 'x' in the list.
     Raises a *note ValueError: 2ec. if there is no such item.

     Gli argomenti opzionali 'start' e 'end' sono interpretati come
     nella notazione delle slice e sono usati per limitare la ricerca a
     una particolare sottosequenza della lista.  L’indice restituito è
     calcolato rispetto all’inizio della sequenza completa piuttosto che
     all’argomento 'start'.

 -- Metodo: list.count (x)

     Restituisce il numero di volte che 'x' appare nella lista.

 -- Metodo: list.sort (*, key=None, reverse=False)

     Ordina gli elementi della lista in loco (gli argomenti possono
     essere usati per la personalizzazione dell’ordinamento, vedere
     *note sorted(): dc9. per la loro spiegazione).

 -- Metodo: list.reverse ()

     Inverte gli elementi della lista in loco.

 -- Metodo: list.copy ()

     Return a shallow copy of the list.  Similar to ‘a[:]’.

Un esempio che utilizza la maggior parte dei metodi della lista:

     >>> fruits = ['orange', 'apple', 'pear', 'banana', 'kiwi', 'apple', 'banana']
     >>> fruits.count('apple')
     2
     >>> fruits.count('tangerine')
     0
     >>> fruits.index('banana')
     3
     >>> fruits.index('banana', 4)  # Find next banana starting at position 4
     6
     >>> fruits.reverse()
     >>> fruits
     ['banana', 'apple', 'kiwi', 'banana', 'pear', 'apple', 'orange']
     >>> fruits.append('grape')
     >>> fruits
     ['banana', 'apple', 'kiwi', 'banana', 'pear', 'apple', 'orange', 'grape']
     >>> fruits.sort()
     >>> fruits
     ['apple', 'apple', 'banana', 'banana', 'grape', 'kiwi', 'orange', 'pear']
     >>> fruits.pop()
     'pear'

Avrai notato che metodi come ‘insert’, ‘remove’ o ‘sort’ che modificano
solo la lista non stampano alcun valore di ritorno – ritornano il
default ‘None’.  (1)  Questo è un principio di design per tutte le
strutture dati mutabili in Python.

Un’altra cosa che potresti notare è che non tutti i dati possono essere
ordinati o confrontati.  Per esempio, ‘[None, 'hello', 10]’ non può
essere ordinata perché gli interi non possono essere confrontati con le
stringhe e ‘None’ non può essere confrontato con altri tipi.  Inoltre,
ci sono alcuni tipi che non hanno una relazione di ordinamento definita.
Ad esempio, ‘3+4j < 5+7j’ non è un confronto valido.

* Menu:

* Usare le Liste come Pile::
* Usare le Liste come Code::
* Comprensioni di Lista::
* Comprensioni di Lista Nidificate::

   ---------- Footnotes ----------

   (1) Altri linguaggi possono restituire l’oggetto mutato, il che
consente di concatenare i metodi, come
‘d->insert("a")->remove("b")->sort();’.


File: python.info,  Node: Usare le Liste come Pile,  Next: Usare le Liste come Code,  Up: Più sulle Liste

2.5.1.1 Usare le Liste come Pile
................................

I metodi delle liste rendono molto facile usare una lista come una pila,
dove l’ultimo elemento aggiunto è il primo elemento recuperato
(«last-in, first-out»).  Per aggiungere un elemento alla cima della
pila, usa *note append(): 8dd.  Per recuperare un elemento dalla cima
della pila, usa *note pop(): 200f. senza un indice esplicito.  Per
esempio:

     >>> stack = [3, 4, 5]
     >>> stack.append(6)
     >>> stack.append(7)
     >>> stack
     [3, 4, 5, 6, 7]
     >>> stack.pop()
     7
     >>> stack
     [3, 4, 5, 6]
     >>> stack.pop()
     6
     >>> stack.pop()
     5
     >>> stack
     [3, 4]


File: python.info,  Node: Usare le Liste come Code,  Next: Comprensioni di Lista,  Prev: Usare le Liste come Pile,  Up: Più sulle Liste

2.5.1.2 Usare le Liste come Code
................................

È anche possibile usare una lista come una coda, dove il primo elemento
aggiunto è il primo elemento recuperato («first-in, first-out»);
tuttavia, le liste non sono efficienti per questo scopo.  Mentre gli
append e i pop dalla fine della lista sono veloci, fare inserzioni o pop
dall’inizio di una lista è lento (perché tutti gli altri elementi devono
essere spostati di uno).

Per implementare una coda, usa *note collections.deque: 7f5. che è stata
progettata per avere append e pop veloci da entrambi i lati.  Per
esempio:

     >>> from collections import deque
     >>> queue = deque(["Eric", "John", "Michael"])
     >>> queue.append("Terry")           # Terry arrives
     >>> queue.append("Graham")          # Graham arrives
     >>> queue.popleft()                 # The first to arrive now leaves
     'Eric'
     >>> queue.popleft()                 # The second to arrive now leaves
     'John'
     >>> queue                           # Remaining queue in order of arrival
     deque(['Michael', 'Terry', 'Graham'])


File: python.info,  Node: Comprensioni di Lista,  Next: Comprensioni di Lista Nidificate,  Prev: Usare le Liste come Code,  Up: Più sulle Liste

2.5.1.3 Comprensioni di Lista
.............................

Le comprensioni di lista forniscono un modo conciso per creare liste.
Le applicazioni comuni sono creare nuove liste dove ogni elemento è il
risultato di alcune operazioni applicate a ciascun membro di un’altra
sequenza o iterabile, o creare una sottosequenza di quegli elementi che
soddisfano una certa condizione.

Per esempio, supponiamo di voler creare una lista di quadrati, come:

     >>> squares = []
     >>> for x in range(10):
     ...     squares.append(x**2)
     ...
     >>> squares
     [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

Nota che questo crea (o sovrascrive) una variabile chiamata ‘x’ che
esiste ancora dopo che il ciclo è completo.  Possiamo calcolare la lista
dei quadrati senza effetti collaterali usando:

     squares = list(map(lambda x: x**2, range(10)))

oppure, equivalentemente:

     squares = [x**2 for x in range(10)]

il che è più conciso e leggibile.

Una comprensione di lista consiste di parentesi contenenti
un’espressione seguita da una clausola ‘for’, quindi zero o più clausole
‘for’ o ‘if’.  Il risultato sarà una nuova lista risultante dalla
valutazione dell’espressione nel contesto delle clausole ‘for’ e ‘if’
che la seguono.  Per esempio, questa listcomp combina gli elementi di
due liste se non sono uguali:

     >>> [(x, y) for x in [1,2,3] for y in [3,1,4] if x != y]
     [(1, 3), (1, 4), (2, 3), (2, 1), (2, 4), (3, 1), (3, 4)]

e equivale a:

     >>> combs = []
     >>> for x in [1,2,3]:
     ...     for y in [3,1,4]:
     ...         if x != y:
     ...             combs.append((x, y))
     ...
     >>> combs
     [(1, 3), (1, 4), (2, 3), (2, 1), (2, 4), (3, 1), (3, 4)]

Nota come l’ordine delle istruzioni *note for: 34a. e *note if: 181. sia
lo stesso in entrambi questi snippet.

Se l’espressione è una tupla (per es.  il ‘(x, y)’ nell’esempio
precedente), deve essere racchiusa tra parentesi.

     >>> vec = [-4, -2, 0, 2, 4]
     >>> # create a new list with the values doubled
     >>> [x*2 for x in vec]
     [-8, -4, 0, 4, 8]
     >>> # filter the list to exclude negative numbers
     >>> [x for x in vec if x >= 0]
     [0, 2, 4]
     >>> # apply a function to all the elements
     >>> [abs(x) for x in vec]
     [4, 2, 0, 2, 4]
     >>> # call a method on each element
     >>> freshfruit = ['  banana', '  loganberry ', 'passion fruit  ']
     >>> [weapon.strip() for weapon in freshfruit]
     ['banana', 'loganberry', 'passion fruit']
     >>> # create a list of 2-tuples like (number, square)
     >>> [(x, x**2) for x in range(6)]
     [(0, 0), (1, 1), (2, 4), (3, 9), (4, 16), (5, 25)]
     >>> # the tuple must be parenthesized, otherwise an error is raised
     >>> [x, x**2 for x in range(6)]
       File "<stdin>", line 1
         [x, x**2 for x in range(6)]
          ^^^^^^^
     SyntaxError: did you forget parentheses around the comprehension target?
     >>> # flatten a list using a listcomp with two 'for'
     >>> vec = [[1,2,3], [4,5,6], [7,8,9]]
     >>> [num for elem in vec for num in elem]
     [1, 2, 3, 4, 5, 6, 7, 8, 9]

Le comprensioni di lista possono contenere espressioni complesse e
funzioni nidificate:

     >>> from math import pi
     >>> [str(round(pi, i)) for i in range(1, 6)]
     ['3.1', '3.14', '3.142', '3.1416', '3.14159']


File: python.info,  Node: Comprensioni di Lista Nidificate,  Prev: Comprensioni di Lista,  Up: Più sulle Liste

2.5.1.4 Comprensioni di Lista Nidificate
........................................

L’espressione iniziale in una comprensione di lista può essere qualsiasi
espressione arbitraria, inclusa un’altra comprensione di lista.

Considera il seguente esempio di una matrice 3x4 implementata come una
lista di 3 liste di lunghezza 4:

     >>> matrix = [
     ...     [1, 2, 3, 4],
     ...     [5, 6, 7, 8],
     ...     [9, 10, 11, 12],
     ... ]

La seguente comprensione di lista trasporrà righe e colonne:

     >>> [[row[i] for row in matrix] for i in range(4)]
     [[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]]

Come abbiamo visto nella sezione precedente, la comprensione di lista
interna è valutata nel contesto del *note for: 34a. che la segue, quindi
questo esempio è equivalente a:

     >>> transposed = []
     >>> for i in range(4):
     ...     transposed.append([row[i] for row in matrix])
     ...
     >>> transposed
     [[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]]

che, a sua volta, è lo stesso di:

     >>> transposed = []
     >>> for i in range(4):
     ...     # the following 3 lines implement the nested listcomp
     ...     transposed_row = []
     ...     for row in matrix:
     ...         transposed_row.append(row[i])
     ...     transposed.append(transposed_row)
     ...
     >>> transposed
     [[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]]

Nel mondo reale, dovresti preferire le funzioni built-in a strutture di
controllo complesse.  La funzione *note zip(): 1a0. farebbe un ottimo
lavoro per questo caso d’uso:

     >>> list(zip(*matrix))
     [(1, 5, 9), (2, 6, 10), (3, 7, 11), (4, 8, 12)]

Vedi *note Spacchettamento delle Liste di Argomenti: 1ffb. per dettagli
sull’asterisco in questa riga.


File: python.info,  Node: L’istruzione del,  Next: Tuple e Sequenze,  Prev: Più sulle Liste,  Up: Strutture Dati

2.5.2 L’istruzione ‘del’
------------------------

Esiste un modo per rimuovere un elemento da una lista dato il suo indice
invece del suo valore: l’istruzione *note del: 1b07.  Questo differisce
dal metodo *note pop(): 200f. che restituisce un valore.  L’istruzione
‘del’ può essere usata anche per rimuovere slice da una lista o per
cancellare l’intera lista (cosa che abbiamo fatto prima assegnando una
lista vuota alla slice).  Per esempio:

     >>> a = [-1, 1, 66.25, 333, 333, 1234.5]
     >>> del a[0]
     >>> a
     [1, 66.25, 333, 333, 1234.5]
     >>> del a[2:4]
     >>> a
     [1, 66.25, 1234.5]
     >>> del a[:]
     >>> a
     []

*note del: 1b07. può anche essere usato per cancellare variabili intere:

     >>> del a

Fare riferimento al nome ‘a’ d’ora in poi è un errore (almeno finché un
altro valore non viene assegnato ad esso).  Troveremo altri usi per
*note del: 1b07. più avanti.


File: python.info,  Node: Tuple e Sequenze,  Next: Insiemi,  Prev: L’istruzione del,  Up: Strutture Dati

2.5.3 Tuple e Sequenze
----------------------

Abbiamo visto che liste e stringhe hanno molte proprietà comuni, come le
operazioni di indicizzazione e slicing.  Sono due esempi di tipi di dati
'sequenza' (vedi *note Tipi di Sequenza — list, tuple, range: 2018.).
Poiché Python è un linguaggio in evoluzione, possono essere aggiunti
altri tipi di dati sequenza.  Esiste anche un altro tipo di dati
sequenza standard: la 'tupla'.

Una tupla consiste in un numero di valori separati da virgole, ad
esempio:

     >>> t = 12345, 54321, 'hello!'
     >>> t[0]
     12345
     >>> t
     (12345, 54321, 'hello!')
     >>> # Tuples may be nested:
     >>> u = t, (1, 2, 3, 4, 5)
     >>> u
     ((12345, 54321, 'hello!'), (1, 2, 3, 4, 5))
     >>> # Tuples are immutable:
     >>> t[0] = 88888
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: 'tuple' object does not support item assignment
     >>> # but they can contain mutable objects:
     >>> v = ([1, 2, 3], [3, 2, 1])
     >>> v
     ([1, 2, 3], [3, 2, 1])

Come vedi, in uscita le tuple sono sempre racchiuse tra parentesi, in
modo che le tuple annidate siano interpretate correttamente; possono
essere inserite con o senza parentesi, anche se spesso le parentesi sono
comunque necessarie (se la tupla fa parte di un’espressione più grande).
Tuttavia, non è possibile assegnare ai singoli elementi di una tupla,
mentre è possibile creare tuple che contengono oggetti mutabili, come le
liste.

Sebbene le tuple possano sembrare simili alle liste, vengono spesso
utilizzate in situazioni diverse e per scopi diversi.  Le tuple sono
*note immutable: 1fc8, e di solito contengono una sequenza eterogenea di
elementi che sono accessibili tramite unpacking (vedi più avanti in
questa sezione) o indicizzazione (o anche per attributo nel caso di
*note namedtuples: 4e1.).  Le liste sono *note mutable: 1fcd, e i loro
elementi sono di solito omogenei e sono accessibili iterando sulla
lista.

Un problema speciale è la costruzione di tuple contenenti 0 o 1
elemento: la sintassi presenta alcune peculiarità per accogliere questi
casi.  Le tuple vuote sono costruite da una coppia di parentesi vuota;
una tupla con un solo elemento è costruita seguendo un valore con una
virgola (non è sufficiente racchiudere un singolo valore tra parentesi).
Brutto, ma efficace.  Ad esempio:

     >>> empty = ()
     >>> singleton = 'hello',    # <-- note trailing comma
     >>> len(empty)
     0
     >>> len(singleton)
     1
     >>> singleton
     ('hello',)

L’istruzione ‘t = 12345, 54321, 'hello!'’ è un esempio di 'tuple
packing': i valori ‘12345’, ‘54321’ e ‘'hello!'’ sono racchiusi insieme
in una tupla.  L’operazione inversa è anche possibile:

     >>> x, y, z = t

Questo è chiamato, appropriatamente, 'sequence unpacking' e funziona per
qualsiasi sequenza sul lato destro.  Lo sequence unpacking richiede che
ci siano tante variabili sul lato sinistro del segno di uguale quante
sono gli elementi nella sequenza.  Nota che l’assegnazione multipla è
davvero solo una combinazione di tuple packing e sequence unpacking.


File: python.info,  Node: Insiemi,  Next: Dizionari,  Prev: Tuple e Sequenze,  Up: Strutture Dati

2.5.4 Insiemi
-------------

Python also includes a data type for *note sets: 201b.  A set is an
unordered collection with no duplicate elements.  Basic uses include
membership testing and eliminating duplicate entries.  Set objects also
support mathematical operations like union, intersection, difference,
and symmetric difference.

Le parentesi graffe o la funzione *note set(): 184. possono essere
utilizzate per creare insiemi.  Nota: per creare un insieme vuoto devi
utilizzare ‘set()’, non ‘{}’; quest’ultimo crea un dizionario vuoto, una
struttura dati che discuteremo nella sezione successiva.

Ecco una breve dimostrazione:

     >>> basket = {'apple', 'orange', 'apple', 'pear', 'orange', 'banana'}
     >>> print(basket)                      # show that duplicates have been removed
     {'orange', 'banana', 'pear', 'apple'}
     >>> 'orange' in basket                 # fast membership testing
     True
     >>> 'crabgrass' in basket
     False

     >>> # Demonstrate set operations on unique letters from two words
     >>>
     >>> a = set('abracadabra')
     >>> b = set('alacazam')
     >>> a                                  # unique letters in a
     {'a', 'r', 'b', 'c', 'd'}
     >>> a - b                              # letters in a but not in b
     {'r', 'd', 'b'}
     >>> a | b                              # letters in a or b or both
     {'a', 'c', 'r', 'd', 'b', 'm', 'z', 'l'}
     >>> a & b                              # letters in both a and b
     {'a', 'c'}
     >>> a ^ b                              # letters in a or b but not both
     {'r', 'd', 'b', 'm', 'z', 'l'}

Analogamente alle *note list comprehensions: 2013, sono supportate anche
le set comprehensions:

     >>> a = {x for x in 'abracadabra' if x not in 'abc'}
     >>> a
     {'r', 'd'}


File: python.info,  Node: Dizionari,  Next: Tecniche di Looping,  Prev: Insiemi,  Up: Strutture Dati

2.5.5 Dizionari
---------------

Un altro tipo di dato utile incorporato in Python è il 'dizionario'
(vedi *note Tipi di Mapping — dict: cbf.).  I dizionari sono a volte
conosciuti in altre lingue come «memorie associative» o «array
associativi».  A differenza delle sequenze, che sono indicizzate da un
intervallo di numeri, i dizionari sono indicizzati da 'chiavi', che
possono essere di qualsiasi tipo immutabile; stringhe e numeri possono
sempre essere chiavi.  Le tuple possono essere usate come chiavi se
contengono solo stringhe, numeri o tuple; se una tupla contiene un
qualsiasi oggetto mutabile direttamente o indirettamente, non può essere
utilizzata come chiave.  Non puoi usare le liste come chiavi, poiché le
liste possono essere modificate in loco usando assegnazioni di indice,
assegnazioni di slice o metodi come *note append(): 8dd. e *note
extend(): 602.

È meglio pensare a un dizionario come a un insieme di coppie 'chiave:
valore', con il requisito che le chiavi siano uniche (all’interno di un
dizionario).  Una coppia di parentesi crea un dizionario vuoto: ‘{}’.
Inserendo una lista di coppie chiave:valore separate da virgole dentro
le parentesi si aggiungono le coppie iniziali al dizionario; questo è
anche il modo in cui i dizionari vengono scritti in uscita.

The main operations on a dictionary are storing a value with some key
and extracting the value given the key.  It is also possible to delete a
key:value pair with ‘del’.  If you store using a key that is already in
use, the old value associated with that key is forgotten.

Extracting a value for a non-existent key by subscripting (‘d[key]’)
raises a *note KeyError: 5e7.  To avoid getting this error when trying
to access a possibly non-existent key, use the *note get(): 201e. method
instead, which returns ‘None’ (or a specified default value) if the key
is not in the dictionary.

Eseguendo ‘list(d)’ su un dizionario si ottiene una lista di tutte le
chiavi utilizzate nel dizionario, in ordine di inserimento (se la vuoi
ordinata, basta usare ‘sorted(d)’).  Per controllare se una singola
chiave è nel dizionario, usa la parola chiave *note in: 34b.

Ecco un piccolo esempio usando un dizionario:

     >>> tel = {'jack': 4098, 'sape': 4139}
     >>> tel['guido'] = 4127
     >>> tel
     {'jack': 4098, 'sape': 4139, 'guido': 4127}
     >>> tel['jack']
     4098
     >>> tel['irv']
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     KeyError: 'irv'
     >>> print(tel.get('irv'))
     None
     >>> del tel['sape']
     >>> tel['irv'] = 4127
     >>> tel
     {'jack': 4098, 'guido': 4127, 'irv': 4127}
     >>> list(tel)
     ['jack', 'guido', 'irv']
     >>> sorted(tel)
     ['guido', 'irv', 'jack']
     >>> 'guido' in tel
     True
     >>> 'jack' not in tel
     False

Il costruttore *note dict(): 183. costruisce dizionari direttamente da
sequenze di coppie chiave-valore:

     >>> dict([('sape', 4139), ('guido', 4127), ('jack', 4098)])
     {'sape': 4139, 'guido': 4127, 'jack': 4098}

Inoltre, le dict comprehensions possono essere utilizzate per creare
dizionari da espressioni di chiave e valore arbitrarie:

     >>> {x: x**2 for x in (2, 4, 6)}
     {2: 4, 4: 16, 6: 36}

Quando le chiavi sono semplici stringhe, a volte è più facile
specificare le coppie utilizzando gli argomenti per parola chiave:

     >>> dict(sape=4139, guido=4127, jack=4098)
     {'sape': 4139, 'guido': 4127, 'jack': 4098}


File: python.info,  Node: Tecniche di Looping,  Next: Maggiori informazioni sulle Condizioni,  Prev: Dizionari,  Up: Strutture Dati

2.5.6 Tecniche di Looping
-------------------------

Quando si scorre un dizionario, è possibile recuperare
contemporaneamente la chiave e il valore corrispondente usando il metodo
*note items(): 9d4.

     >>> knights = {'gallahad': 'the pure', 'robin': 'the brave'}
     >>> for k, v in knights.items():
     ...     print(k, v)
     ...
     gallahad the pure
     robin the brave

Quando si scorre una sequenza, è possibile recuperare contemporaneamente
l’indice di posizione e il valore corrispondente usando la funzione
*note enumerate(): 1688.

     >>> for i, v in enumerate(['tic', 'tac', 'toe']):
     ...     print(i, v)
     ...
     0 tic
     1 tac
     2 toe

Per scorrere due o più sequenze contemporaneamente, le voci possono
essere abbinate con la funzione *note zip(): 1a0.

     >>> questions = ['name', 'quest', 'favorite color']
     >>> answers = ['lancelot', 'the holy grail', 'blue']
     >>> for q, a in zip(questions, answers):
     ...     print('What is your {0}?  It is {1}.'.format(q, a))
     ...
     What is your name?  It is lancelot.
     What is your quest?  It is the holy grail.
     What is your favorite color?  It is blue.

Per scorrere una sequenza al contrario, specifica prima la sequenza in
direzione avanti e poi chiama la funzione *note reversed(): a67.

     >>> for i in reversed(range(1, 10, 2)):
     ...     print(i)
     ...
     9
     7
     5
     3
     1

Per scorrere una sequenza in ordine ordinato, usa la funzione *note
sorted(): dc9. che restituisce una nuova lista ordinata lasciando
invariata la sorgente.

     >>> basket = ['apple', 'orange', 'apple', 'pear', 'orange', 'banana']
     >>> for i in sorted(basket):
     ...     print(i)
     ...
     apple
     apple
     banana
     orange
     orange
     pear

Usare *note set(): 184. su una sequenza elimina gli elementi duplicati.
L’uso di *note sorted(): dc9. in combinazione con *note set(): 184. su
una sequenza è un modo idiomatico di scorrere gli elementi unici della
sequenza in ordine ordinato.

     >>> basket = ['apple', 'orange', 'apple', 'pear', 'orange', 'banana']
     >>> for f in sorted(set(basket)):
     ...     print(f)
     ...
     apple
     banana
     orange
     pear

A volte è allettante modificare una lista mentre la stai scorrendo;
tuttavia, è spesso più semplice e sicuro creare una nuova lista invece.

     >>> import math
     >>> raw_data = [56.2, float('NaN'), 51.7, 55.3, 52.5, float('NaN'), 47.8]
     >>> filtered_data = []
     >>> for value in raw_data:
     ...     if not math.isnan(value):
     ...         filtered_data.append(value)
     ...
     >>> filtered_data
     [56.2, 51.7, 55.3, 52.5, 47.8]


File: python.info,  Node: Maggiori informazioni sulle Condizioni,  Next: Confronto tra Sequenze e Altri Tipi,  Prev: Tecniche di Looping,  Up: Strutture Dati

2.5.7 Maggiori informazioni sulle Condizioni
--------------------------------------------

Le condizioni utilizzate nelle istruzioni ‘while’ e ‘if’ possono
contenere qualsiasi operatore, non solo confronti.

Gli operatori di confronto ‘in’ e ‘not in’ sono test di appartenenza che
determinano se un valore è (o non è) in un contenitore.  Gli operatori
‘is’ e ‘is not’ confrontano se due oggetti sono davvero lo stesso
oggetto.  Tutti gli operatori di confronto hanno la stessa priorità, che
è inferiore a quella di tutti gli operatori numerici.

I confronti possono essere concatenati.  Ad esempio, ‘a < b == c’
verifica se ‘a’ è minore di ‘b’ e inoltre se ‘b’ è uguale a ‘c’.

I confronti possono essere combinati usando gli operatori booleani ‘and’
e ‘or’, e il risultato di un confronto (o di qualsiasi altra espressione
booleana) può essere negato con ‘not’.  Questi hanno una priorità
inferiore rispetto agli operatori di confronto; tra di loro, ‘not’ ha la
priorità più alta e ‘or’ la più bassa, in modo che ‘A and not B or C’
sia equivalente a ‘(A and (not B)) or C’.  Come sempre, le parentesi
possono essere utilizzate per esprimere la composizione desiderata.

Gli operatori booleani ‘and’ e ‘or’ sono i cosiddetti operatori
'short-circuit': i loro argomenti vengono valutati da sinistra a destra,
e la valutazione si arresta non appena l’esito è determinato.  Ad
esempio, se ‘A’ e ‘C’ sono veri ma ‘B’ è falso, ‘A and B and C’ non
valuta l’espressione ‘C’.  Quando vengono utilizzati come un valore
generale e non come booleani, il valore restituito di un operatore
short-circuit è l’ultimo argomento valutato.

È possibile assegnare il risultato di un confronto o di un’altra
espressione booleana a una variabile.  Ad esempio,

     >>> string1, string2, string3 = '', 'Trondheim', 'Hammer Dance'
     >>> non_null = string1 or string2 or string3
     >>> non_null
     'Trondheim'

Nota che in Python, a differenza del C, l’assegnazione dentro
espressioni deve essere fatta esplicitamente con l’operatore detto *note
walrus operator: 2022. ‘:=’.  Questo evita una comune classe di problemi
incontrati nei programmi C: digitare ‘=’ in un’espressione quando si
intendeva ‘==’.


File: python.info,  Node: Confronto tra Sequenze e Altri Tipi,  Prev: Maggiori informazioni sulle Condizioni,  Up: Strutture Dati

2.5.8 Confronto tra Sequenze e Altri Tipi
-----------------------------------------

Gli oggetti sequenza possono essere tipicamente confrontati con altri
oggetti dello stesso tipo di sequenza.  Il confronto usa l’ordinamento
'lessicografico': prima vengono confrontati i primi due elementi, e se
differiscono questo determina il risultato del confronto; se sono
uguali, vengono confrontati i due successivi, e così via, fino a quando
una delle due sequenze è esaurita.  Se gli elementi da confrontare sono
essi stessi sequenze dello stesso tipo, il confronto lessicografico
viene effettuato ricorsivamente.  Se tutti gli elementi di due sequenze
sono uguali tra di loro, le sequenze sono considerate uguali.  Se una
sequenza è una sottosequenza iniziale dell’altra, la sequenza più corta
è considerata la minore.  L’ordinamento lessicografico per le stringhe
utilizza il numero del punto di codice Unicode per ordinare i singoli
caratteri.  Alcuni esempi di confronti tra sequenze dello stesso tipo:

     (1, 2, 3)              < (1, 2, 4)
     [1, 2, 3]              < [1, 2, 4]
     'ABC' < 'C' < 'Pascal' < 'Python'
     (1, 2, 3, 4)           < (1, 2, 4)
     (1, 2)                 < (1, 2, -1)
     (1, 2, 3)             == (1.0, 2.0, 3.0)
     (1, 2, ('aa', 'ab'))   < (1, 2, ('abc', 'a'), 4)

Nota che confrontare oggetti di tipi diversi con ‘<’ o ‘>’ è legale a
condizione che gli oggetti abbiano metodi di confronto appropriati.  Ad
esempio, i tipi numerici misti sono confrontati in base al loro valore
numerico, quindi 0 è uguale a 0.0, ecc.  Altrimenti, invece di fornire
un ordinamento arbitrario, l’interprete alzerà un’eccezione *note
TypeError: 198.


File: python.info,  Node: Moduli,  Next: Input e Output,  Prev: Strutture Dati,  Up: Tutorial su Python

2.6 Moduli
==========

Se chiudi l’interprete Python e lo riapri, le definizioni che hai fatto
(funzioni e variabili) vengono perse.  Pertanto, se vuoi scrivere un
programma un po” più lungo, è meglio usare un editor di testo per
preparare l’input per l’interprete e eseguirlo con quel file come input.
Questo è conosciuto come creare uno 'script'.  Man mano che il tuo
programma diventa più lungo, potresti volerlo dividere in diversi file
per una manutenzione più facile.  Potresti anche voler usare una
funzione utile che hai scritto in diversi programmi senza copiarne la
definizione in ciascun programma.

Per supportare questo, Python ha un modo per mettere definizioni in un
file e usarle in uno script o in un’istanza interattiva dell’interprete.
Tale file è chiamato un 'modulo'; le definizioni di un modulo possono
essere 'importate' in altri moduli o nel 'modulo principale' (la
collezione di variabili a cui hai accesso in uno script eseguito al
livello superiore e in modalità calcolatrice).

Un modulo è un file contenente definizioni e istruzioni Python.  Il nome
del file è il nome del modulo con il suffisso ‘.py’ aggiunto.
All’interno di un modulo, il nome del modulo (come stringa) è
disponibile come valore della variabile globale ‘__name__’.  Ad esempio,
usa il tuo editor di testo preferito per creare un file chiamato
‘fibo.py’ nella directory corrente con il seguente contenuto:

     # Fibonacci numbers module

     def fib(n):
         """Write Fibonacci series up to n."""
         a, b = 0, 1
         while a < n:
             print(a, end=' ')
             a, b = b, a+b
         print()

     def fib2(n):
         """Return Fibonacci series up to n."""
         result = []
         a, b = 0, 1
         while a < n:
             result.append(a)
             a, b = b, a+b
         return result

Ora entra nell’interprete Python e importa questo modulo con il seguente
comando:

     >>> import fibo

Questo non aggiunge i nomi delle funzioni definite in ‘fibo’
direttamente all’attuale *note namespace: 2029. (vedi *note Visibilità e
spazi dei nomi in Python: 202a. per maggiori dettagli); aggiunge solo il
nome del modulo ‘fibo’ lì.  Utilizzando il nome del modulo puoi accedere
alle funzioni:

     >>> fibo.fib(1000)
     0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987
     >>> fibo.fib2(100)
     [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]
     >>> fibo.__name__
     'fibo'

Se intendi usare una funzione spesso puoi assegnarla a un nome locale:

     >>> fib = fibo.fib
     >>> fib(500)
     0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

* Menu:

* Più sui Moduli::
* Moduli Standard::
* La funzione dir(): La funzione dir.
* Pacchetti::


File: python.info,  Node: Più sui Moduli,  Next: Moduli Standard,  Up: Moduli

2.6.1 Più sui Moduli
--------------------

Un modulo può contenere istruzioni eseguibili così come definizioni di
funzioni.  Queste istruzioni sono intese per inizializzare il modulo.
Sono eseguite solo la 'prima' volta che il nome del modulo viene
incontrato in un’istruzione d’importazione.  (1)  (Sono anche eseguite
se il file è eseguito come script.)

Ogni modulo ha il proprio namespace privato, che è utilizzato come il
namespace globale da tutte le funzioni definite nel modulo.  Pertanto,
l’autore di un modulo può usare variabili globali nel modulo senza
preoccuparsi di collisioni accidentali con le variabili globali di un
utente.  D’altra parte, se sai quello che stai facendo puoi toccare le
variabili globali di un modulo con la stessa notazione utilizzata per
riferirsi alle sue funzioni, ‘modname.itemname’.

I moduli possono importare altri moduli.  È consuetudine, ma non
obbligatorio, posizionare tutte le istruzioni *note import: 7f9.
all’inizio di un modulo (o script, se è per questo).  I nomi dei moduli
importati, se posizionati a livello superiore di un modulo (fuori da
qualsiasi funzione o classe), sono aggiunti al namespace globale del
modulo.

Esiste una variante dell’istruzione *note import: 7f9. che importa nomi
da un modulo direttamente nel namespace del modulo importante.  Ad
esempio:

     >>> from fibo import fib, fib2
     >>> fib(500)
     0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

Questo non introduce il nome del modulo da cui provengono le
importazioni nel namespace locale (quindi nell’esempio, ‘fibo’ non è
definito).

Esiste anche una variante per importare tutti i nomi che un modulo
definisce:

     >>> from fibo import *
     >>> fib(500)
     0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

Questo importa tutti i nomi eccetto quelli che iniziano con un
underscore (‘_’).  Nella maggior parte dei casi i programmatori Python
non utilizzano questa funzione poiché introduce un insieme sconosciuto
di nomi nell’interprete, nascondendo possibilmente alcune cose che hai
già definito.

Nota che in generale la pratica di importare ‘*’ da un modulo o
pacchetto è disapprovata, poiché spesso causa codice poco leggibile.
Tuttavia, è accettabile usarla per risparmiare battitura nelle sessioni
interattive.

Se il nome del modulo è seguito da ‘as’, allora il nome che segue ‘as’ è
legato direttamente al modulo importato.

     >>> import fibo as fib
     >>> fib.fib(500)
     0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

Questo importa effettivamente il modulo nello stesso modo in cui lo
farebbe ‘import fibo’, con l’unica differenza che sarà disponibile come
‘fib’.

Può anche essere utilizzato quando si utilizza *note from: 14b3. con
effetti simili:

     >>> from fibo import fib as fibonacci
     >>> fibonacci(500)
     0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

     Nota: Per ragioni di efficienza, ogni modulo viene importato una
     sola volta per sessione dell’interprete.  Pertanto, se cambi i tuoi
     moduli, devi riavviare l’interprete – o, se è solo un modulo che
     vuoi testare interattivamente, usa *note importlib.reload(): 73e,
     es.  ‘import importlib; importlib.reload(modulename)’.

* Menu:

* Esecuzione di moduli come script::
* Il percorso di ricerca del modulo::
* File Python «compilati»::

   ---------- Footnotes ----------

   (1) In realtà anche le definizioni di funzione sono “istruzioni” che
vengono “eseguite”; l’esecuzione di una definizione di funzione a
livello di modulo aggiunge il nome della funzione allo spazio dei nomi
globale del modulo.


File: python.info,  Node: Esecuzione di moduli come script,  Next: Il percorso di ricerca del modulo,  Up: Più sui Moduli

2.6.1.1 Esecuzione di moduli come script
........................................

Quando esegui un modulo Python con

     python fibo.py <arguments>

il codice nel modulo sarà eseguito, proprio come se lo avessi importato,
ma con ‘__name__’ impostato su ‘"__main__"’.  Ciò significa che
aggiungendo questo codice alla fine del tuo modulo:

     if __name__ == "__main__":
         import sys
         fib(int(sys.argv[1]))

puoi rendere il file utilizzabile sia come script che come modulo
importabile, poiché il codice che analizza la linea di comando viene
eseguito solo se il modulo è eseguito come file «principale»:

     $ python fibo.py 50
     0 1 1 2 3 5 8 13 21 34

Se il modulo è importato, il codice non viene eseguito:

     >>> import fibo
     >>>

Questo è spesso usato sia per fornire un’interfaccia utente comoda a un
modulo, sia per scopi di test (eseguire il modulo come script esegue una
suite di test).


File: python.info,  Node: Il percorso di ricerca del modulo,  Next: File Python «compilati»,  Prev: Esecuzione di moduli come script,  Up: Più sui Moduli

2.6.1.2 Il percorso di ricerca del modulo
.........................................

Quando un modulo chiamato ‘spam’ è importato, l’interprete cerca prima
un modulo built-in con quel nome.  Questi nomi di moduli sono elencati
in *note sys.builtin_module_names: 2031.  Se non viene trovato, allora
cerca un file chiamato ‘spam.py’ in una lista di directory data dalla
variabile *note sys.path: 3e4.  *note sys.path: 3e4. è inizializzata da
queste posizioni:

   * La directory contenente lo script di input (o la directory corrente
     quando non è specificato alcun file).

   * *note PYTHONPATH: 121f. (una lista di nomi di directory, con la
     stessa sintassi della variabile di shell ‘PATH’).

   * Il valore predefinito dipendente dall’installazione (per
     convenzione include una directory ‘site-packages’, gestita dal
     modulo *note site: cc.).

Maggiori dettagli sono disponibili in *note The initialization of the
sys.path module search path: 18c4.

     Nota: Su file system che supportano i collegamenti simbolici, la
     directory contenente lo script di input viene calcolata dopo che il
     collegamento simbolico è stato seguito.  In altre parole la
     directory contenente il collegamento simbolico 'non' è aggiunta al
     percorso di ricerca del modulo.

Dopo l’inizializzazione, i programmi Python possono modificare *note
sys.path: 3e4.  La directory contenente lo script in esecuzione è
posizionata all’inizio del percorso di ricerca, davanti al percorso
della libreria standard.  Ciò significa che gli script in quella
directory saranno caricati invece dei moduli con lo stesso nome nella
directory della libreria.  Questo è un errore a meno che la sostituzione
non sia intenzionale.  Vedi la sezione *note Moduli Standard: 2032. per
maggiori informazioni.


File: python.info,  Node: File Python «compilati»,  Prev: Il percorso di ricerca del modulo,  Up: Più sui Moduli

2.6.1.3 File Python «compilati»
...............................

Per velocizzare il caricamento dei moduli, Python memorizza nella cache
la versione compilata di ciascun modulo nella directory ‘__pycache__’
sotto il nome ‘module.`version'.pyc’, dove la versione codifica il
formato del file compilato; contiene generalmente il numero di versione
di Python.  Ad esempio, nella versione CPython 3.3, la versione
compilata di spam.py verrebbe memorizzata nella cache come
‘__pycache__/spam.cpython-33.pyc’.  Questa convenzione di denominazione
permette ai moduli compilati di versioni diverse e rilasci diversi di
Python di coesistere.

Python controlla la data di modifica della sorgente rispetto alla
versione compilata per vedere se è obsoleta e deve essere ricompilata.
Questo è un processo completamente automatico.  Inoltre, i moduli
compilati sono indipendenti dalla piattaforma, quindi la stessa libreria
può essere condivisa tra sistemi con diverse architetture.

Python non controlla la cache in due circostanze.  Primo, ricompila
sempre e non memorizza il risultato per il modulo caricato direttamente
dalla linea di comando.  Secondo, non controlla la cache se non esiste
il modulo sorgente.  Per supportare una distribuzione senza sorgente
(solo compilata), il modulo compilato deve essere nella directory
sorgente e non deve esserci un modulo sorgente.

Alcuni consigli per esperti:

   * Puoi usare le opzioni *note -O: 18c. o *note -OO: fb7. sul comando
     Python per ridurre la dimensione di un modulo compilato.  L’opzione
     ‘-O’ rimuove le istruzioni assert, l’opzione ‘-OO’ rimuove sia le
     istruzioni assert che le stringhe __doc__.  Poiché alcuni programmi
     possono fare affidamento su queste, dovresti usare questa opzione
     solo se sai quello che stai facendo.  I moduli «ottimizzati» hanno
     un tag ‘opt-’ e sono solitamente più piccoli.  I futuri rilasci
     possono cambiare gli effetti dell’ottimizzazione.

   * Un programma non gira più velocemente quando è letto da un file
     ‘.pyc’ rispetto a quando è letto da un file ‘.py’; l’unica cosa che
     è più veloce nei file ‘.pyc’ è la velocità con cui vengono
     caricati.

   * Il modulo *note compileall: 21. può creare file .pyc per tutti i
     moduli in una directory.

   * Ci sono maggiori dettagli su questo processo, incluso un diagramma
     di flusso delle decisioni, in PEP 3147(1).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3147/


File: python.info,  Node: Moduli Standard,  Next: La funzione dir,  Prev: Più sui Moduli,  Up: Moduli

2.6.2 Moduli Standard
---------------------

Python viene fornito con una libreria di moduli standard, descritta in
un documento separato, il Python Library Reference («Library Reference»
da qui in avanti).  Alcuni moduli sono incorporati nell’interprete;
questi forniscono accesso a operazioni che non fanno parte del core del
linguaggio ma sono comunque incorporate, sia per efficienza che per
fornire accesso a primitive del sistema operativo come le chiamate di
sistema.  Il set di tali moduli è un’opzione di configurazione che
dipende anche dalla piattaforma sottostante.  Ad esempio, il modulo
*note winreg: 11c. è fornito solo sui sistemi Windows.  Un particolare
modulo merita attenzione: *note sys: df, che è incorporato in ogni
interprete Python.  Le variabili ‘sys.ps1’ e ‘sys.ps2’ definiscono le
stringhe usate come prompt primario e secondario:

     >>> import sys
     >>> sys.ps1
     '>>> '
     >>> sys.ps2
     '... '
     >>> sys.ps1 = 'C> '
     C> print('Yuck!')
     Yuck!
     C>

Queste due variabili sono definite solo se l’interprete è in modalità
interattiva.

La variabile ‘sys.path’ è una lista di stringhe che determina il
percorso di ricerca dell’interprete per i moduli.  È inizializzata a un
percorso predefinito preso dalla variabile di ambiente *note PYTHONPATH:
121f, o da un predefinito incorporato se *note PYTHONPATH: 121f. non è
impostato.  Puoi modificarla usando le operazioni standard delle liste:

     >>> import sys
     >>> sys.path.append('/ufs/guido/lib/python')


File: python.info,  Node: La funzione dir,  Next: Pacchetti,  Prev: Moduli Standard,  Up: Moduli

2.6.3 La funzione ‘dir()’
-------------------------

La funzione built-in *note dir(): 845. è usata per scoprire quali nomi
definisce un modulo.  Restituisce una lista ordinata di stringhe:

     >>> import fibo, sys
     >>> dir(fibo)
     ['__name__', 'fib', 'fib2']
     >>> dir(sys)
     ['__breakpointhook__', '__displayhook__', '__doc__', '__excepthook__',
      '__interactivehook__', '__loader__', '__name__', '__package__', '__spec__',
      '__stderr__', '__stdin__', '__stdout__', '__unraisablehook__',
      '_clear_type_cache', '_current_frames', '_debugmallocstats', '_framework',
      '_getframe', '_git', '_home', '_xoptions', 'abiflags', 'addaudithook',
      'api_version', 'argv', 'audit', 'base_exec_prefix', 'base_prefix',
      'breakpointhook', 'builtin_module_names', 'byteorder', 'call_tracing',
      'callstats', 'copyright', 'displayhook', 'dont_write_bytecode', 'exc_info',
      'excepthook', 'exec_prefix', 'executable', 'exit', 'flags', 'float_info',
      'float_repr_style', 'get_asyncgen_hooks', 'get_coroutine_origin_tracking_depth',
      'getallocatedblocks', 'getdefaultencoding', 'getdlopenflags',
      'getfilesystemencodeerrors', 'getfilesystemencoding', 'getprofile',
      'getrecursionlimit', 'getrefcount', 'getsizeof', 'getswitchinterval',
      'gettrace', 'hash_info', 'hexversion', 'implementation', 'int_info',
      'intern', 'is_finalizing', 'last_traceback', 'last_type', 'last_value',
      'maxsize', 'maxunicode', 'meta_path', 'modules', 'path', 'path_hooks',
      'path_importer_cache', 'platform', 'prefix', 'ps1', 'ps2', 'pycache_prefix',
      'set_asyncgen_hooks', 'set_coroutine_origin_tracking_depth', 'setdlopenflags',
      'setprofile', 'setrecursionlimit', 'setswitchinterval', 'settrace', 'stderr',
      'stdin', 'stdout', 'thread_info', 'unraisablehook', 'version', 'version_info',
      'warnoptions']

Senza argomenti, *note dir(): 845. elenca i nomi che hai definito
attualmente:

     >>> a = [1, 2, 3, 4, 5]
     >>> import fibo
     >>> fib = fibo.fib
     >>> dir()
     ['__builtins__', '__name__', 'a', 'fib', 'fibo', 'sys']

Nota che elenca tutti i tipi di nomi: variabili, moduli, funzioni, ecc.

*note dir(): 845. non elenca i nomi delle funzioni e variabili built-in.
Se vuoi una lista di questi, sono definiti nel modulo standard *note
builtins: 13.:

     >>> import builtins
     >>> dir(builtins)
     ['ArithmeticError', 'AssertionError', 'AttributeError', 'BaseException',
      'BlockingIOError', 'BrokenPipeError', 'BufferError', 'BytesWarning',
      'ChildProcessError', 'ConnectionAbortedError', 'ConnectionError',
      'ConnectionRefusedError', 'ConnectionResetError', 'DeprecationWarning',
      'EOFError', 'Ellipsis', 'EnvironmentError', 'Exception', 'False',
      'FileExistsError', 'FileNotFoundError', 'FloatingPointError',
      'FutureWarning', 'GeneratorExit', 'IOError', 'ImportError',
      'ImportWarning', 'IndentationError', 'IndexError', 'InterruptedError',
      'IsADirectoryError', 'KeyError', 'KeyboardInterrupt', 'LookupError',
      'MemoryError', 'NameError', 'None', 'NotADirectoryError', 'NotImplemented',
      'NotImplementedError', 'OSError', 'OverflowError',
      'PendingDeprecationWarning', 'PermissionError', 'ProcessLookupError',
      'ReferenceError', 'ResourceWarning', 'RuntimeError', 'RuntimeWarning',
      'StopIteration', 'SyntaxError', 'SyntaxWarning', 'SystemError',
      'SystemExit', 'TabError', 'TimeoutError', 'True', 'TypeError',
      'UnboundLocalError', 'UnicodeDecodeError', 'UnicodeEncodeError',
      'UnicodeError', 'UnicodeTranslateError', 'UnicodeWarning', 'UserWarning',
      'ValueError', 'Warning', 'ZeroDivisionError', '_', '__build_class__',
      '__debug__', '__doc__', '__import__', '__name__', '__package__', 'abs',
      'all', 'any', 'ascii', 'bin', 'bool', 'bytearray', 'bytes', 'callable',
      'chr', 'classmethod', 'compile', 'complex', 'copyright', 'credits',
      'delattr', 'dict', 'dir', 'divmod', 'enumerate', 'eval', 'exec', 'exit',
      'filter', 'float', 'format', 'frozenset', 'getattr', 'globals', 'hasattr',
      'hash', 'help', 'hex', 'id', 'input', 'int', 'isinstance', 'issubclass',
      'iter', 'len', 'license', 'list', 'locals', 'map', 'max', 'memoryview',
      'min', 'next', 'object', 'oct', 'open', 'ord', 'pow', 'print', 'property',
      'quit', 'range', 'repr', 'reversed', 'round', 'set', 'setattr', 'slice',
      'sorted', 'staticmethod', 'str', 'sum', 'super', 'tuple', 'type', 'vars',
      'zip']


File: python.info,  Node: Pacchetti,  Prev: La funzione dir,  Up: Moduli

2.6.4 Pacchetti
---------------

I pacchetti sono un modo di strutturare il namespace dei moduli di
Python usando «nomi di moduli puntati».  Ad esempio, il nome del modulo
‘A.B’ designa un sottomodulo chiamato ‘B’ in un pacchetto chiamato ‘A’.
Proprio come l’uso dei moduli salva gli autori di diversi moduli dal
preoccuparsi dei nomi delle variabili globali degli altri, l’uso dei
nomi di moduli puntati salva gli autori di pacchetti multi-modulo come
NumPy o Pillow dal preoccuparsi dei nomi dei moduli degli altri.

Supponiamo che tu voglia progettare una collezione di moduli (un
«pacchetto») per la gestione uniforme dei file audio e dei dati audio.
Ci sono molti formati di file audio diversi (di solito riconosciuti
dalla loro estensione, ad esempio: ‘.wav’, ‘.aiff’, ‘.au’), quindi
potresti aver bisogno di creare e mantenere una collezione crescente di
moduli per la conversione tra i vari formati di file.  Ci sono anche
molte operazioni diverse che potresti voler eseguire sui dati audio
(come il mixaggio, l’aggiunta di eco, l’applicazione di una funzione
equalizzatrice, la creazione di un effetto stereo artificiale), quindi,
in aggiunta, scriverai una serie interminabile di moduli per eseguire
queste operazioni.  Ecco una possibile struttura per il tuo pacchetto
(espressa in termini di filesystem gerarchico):

     sound/                          Top-level package
           __init__.py               Initialize the sound package
           formats/                  Subpackage for file format conversions
                   __init__.py
                   wavread.py
                   wavwrite.py
                   aiffread.py
                   aiffwrite.py
                   auread.py
                   auwrite.py
                   ...
           effects/                  Subpackage for sound effects
                   __init__.py
                   echo.py
                   surround.py
                   reverse.py
                   ...
           filters/                  Subpackage for filters
                   __init__.py
                   equalizer.py
                   vocoder.py
                   karaoke.py
                   ...

Quando importa il pacchetto, Python cerca nelle directory su ‘sys.path’
cercando la sottodirectory del pacchetto.

I file ‘__init__.py’ sono richiesti per fare in modo che Python tratti
le directory contenenti il file come pacchetti (a meno che non si
utilizzi un *note namespace package: 2b2, una funzionalità relativamente
avanzata).  Questo impedisce alle directory con un nome comune, come
‘string’, di nascondere inavvertitamente moduli validi che si trovano
più avanti nel percorso di ricerca del modulo.  Nel caso più semplice,
‘__init__.py’ può essere solo un file vuoto, ma può anche eseguire
codice di inizializzazione per il pacchetto o impostare la variabile
‘__all__’, descritta più avanti.

Gli utenti del pacchetto possono importare moduli individuali dal
pacchetto, ad esempio:

     import sound.effects.echo

Questo carica il sottomodulo ‘sound.effects.echo’.  Deve essere
referenziato con il suo nome completo.:

     sound.effects.echo.echofilter(input, output, delay=0.7, atten=4)

Un modo alternativo di importare il sottomodulo è:

     from sound.effects import echo

Questo carica anche il sottomodulo ‘echo’, e lo rende disponibile senza
il prefisso del pacchetto, quindi può essere usato come segue:

     echo.echofilter(input, output, delay=0.7, atten=4)

Un’ulteriore variazione è importare direttamente la funzione o la
variabile desiderata:

     from sound.effects.echo import echofilter

Ancora una volta, questo carica il sottomodulo ‘echo’, ma rende
direttamente disponibile la sua funzione ‘echofilter()’:

     echofilter(input, output, delay=0.7, atten=4)

Nota che quando usi ‘from package import item’, l’elemento può essere un
sottomodulo (o sottopacchetto) del pacchetto, o qualche altro nome
definito nel pacchetto, come una funzione, classe o variabile.
L’istruzione ‘import’ testa prima se l’elemento è definito nel
pacchetto; se non lo è, assume che sia un modulo e tenta di caricarlo.
Se non riesce a trovarlo, viene sollevata un’eccezione *note
ImportError: 65b.

Al contrario, quando usi una sintassi come ‘import
item.subitem.subsubitem’, ciascun elemento tranne l’ultimo deve essere
un pacchetto; l’ultimo elemento può essere un modulo o un pacchetto ma
non può essere una classe, funzione o variabile definita nell’elemento
precedente.

* Menu:

* Importare * Da un Pacchetto::
* Riferimenti Intra-pacchetto::
* Pacchetti in Directory Multiple::


File: python.info,  Node: Importare * Da un Pacchetto,  Next: Riferimenti Intra-pacchetto,  Up: Pacchetti

2.6.4.1 Importare * Da un Pacchetto
...................................

Ora cosa succede quando l’utente scrive ‘from sound.effects import *’?
Idealmente, si spera che questo vada in qualche modo nel filesystem,
trovi quali sottomoduli sono presenti nel pacchetto e li importi tutti.
Questo potrebbe richiedere molto tempo e l’importazione di sottomoduli
potrebbe avere effetti collaterali indesiderati che dovrebbero accadere
solo quando il sottomodulo viene importato esplicitamente.

L’unica soluzione è che l’autore del pacchetto fornisca un indice
esplicito del pacchetto.  L’istruzione *note import: 7f9. utilizza la
seguente convenzione: se il codice di ‘__init__.py’ di un pacchetto
definisce una lista denominata ‘__all__’, essa è considerata la lista
dei nomi dei moduli che dovrebbero essere importati quando si incontra
‘from package import *’.  È compito dell’autore del pacchetto mantenere
aggiornata questa lista quando viene rilasciata una nuova versione del
pacchetto.  Gli autori dei pacchetti possono anche decidere di non
supportarla, se non vedono un’utilità per l’importazione * dal loro
pacchetto.  Ad esempio, il file ‘sound/effects/__init__.py’ potrebbe
contenere il seguente codice:

     __all__ = ["echo", "surround", "reverse"]

Questo significherebbe che ‘from sound.effects import *’ importerebbe i
tre sottomoduli denominati del pacchetto ‘sound.effects’.

Tieni presente che i sottomoduli potrebbero essere ombreggiati da nomi
definiti localmente.  Ad esempio, se aggiungi una funzione ‘reverse’ al
file ‘sound/effects/__init__.py’, ‘from sound.effects import *’
importerebbe solo i due sottomoduli ‘echo’ e ‘surround’, ma 'non' il
sottomodulo ‘reverse’, perché è oscurato dalla funzione ‘reverse’
definita localmente.:

     __all__ = [
         "echo",      # refers to the 'echo.py' file
         "surround",  # refers to the 'surround.py' file
         "reverse",   # !!! refers to the 'reverse' function now !!!
     ]

     def reverse(msg: str):  # <-- this name shadows the 'reverse.py' submodule
         return msg[::-1]    #     in the case of a 'from sound.effects import *'

Se ‘__all__’ non è definito, l’istruzione ‘from sound.effects import *’
'non' importa tutti i sottomoduli del pacchetto ‘sound.effects’ nello
spazio dei nomi corrente; si limita ad assicurare che il pacchetto
‘sound.effects’ sia stato importato (eventualmente eseguendo qualsiasi
codice di inizializzazione in ‘__init__.py’) e quindi importa solo i
nomi definiti nel pacchetto.  Questo include qualsiasi nome definito (e
sottomoduli esplicitamente caricati) nel file ‘__init__.py’.  Include
anche eventuali sottomoduli del pacchetto che sono stati esplicitamente
caricati da precedenti istruzioni di *note import: 7f9.  Considera
questo codice:

     import sound.effects.echo
     import sound.effects.surround
     from sound.effects import *

In questo esempio, i moduli ‘echo’ e ‘surround’ sono importati nello
spazio dei nomi corrente perché sono definiti nel pacchetto
‘sound.effects’ quando viene eseguita l’istruzione ‘from...import’.
(Questo funziona anche quando è definito ‘__all__’.)

Sebbene certi moduli siano progettati per esportare solo nomi che
seguono certi schemi quando usi ‘import *’, è comunque considerata una
cattiva pratica nel codice di produzione.

Ricorda, non c’è nulla di sbagliato nell’usare ‘from package import
specific_submodule’!  Infatti, questa è la notazione raccomandata a meno
che il modulo importante non debba usare sottomoduli con lo stesso nome
da pacchetti differenti.


File: python.info,  Node: Riferimenti Intra-pacchetto,  Next: Pacchetti in Directory Multiple,  Prev: Importare * Da un Pacchetto,  Up: Pacchetti

2.6.4.2 Riferimenti Intra-pacchetto
...................................

Quando i pacchetti sono strutturati in sottopacchetti (come il pacchetto
‘sound’ nell’esempio), puoi usare importazioni assolute per riferirti a
sottomoduli di pacchetti fratelli.  Ad esempio, se il modulo
‘sound.filters.vocoder’ deve utilizzare il modulo ‘echo’ nel pacchetto
‘sound.effects’, può usare ‘from sound.effects import echo’.

Puoi anche scrivere importazioni relative, con la forma dell’istruzione
di importazione ‘from module import name’.  Queste importazioni
utilizzano punti di testa per indicare i pacchetti corrente e genitore
coinvolti nell’importazione relativa.  Dal modulo ‘surround’, ad
esempio, potresti usare:

     from . import echo
     from .. import formats
     from ..filters import equalizer

Note that relative imports are based on the name of the current module’s
package.  Since the main module does not have a package, modules
intended for use as the main module of a Python application must always
use absolute imports.


File: python.info,  Node: Pacchetti in Directory Multiple,  Prev: Riferimenti Intra-pacchetto,  Up: Pacchetti

2.6.4.3 Pacchetti in Directory Multiple
.......................................

Packages support one more special attribute, *note __path__: 203e.  This
is initialized to be a *note sequence: 717. of strings containing the
name of the directory holding the package’s ‘__init__.py’ before the
code in that file is executed.  This variable can be modified; doing so
affects future searches for modules and subpackages contained in the
package.

Sebbene questa funzione non sia spesso necessaria, può essere utilizzata
per estendere il set di moduli trovati in un pacchetto.

Note
....


File: python.info,  Node: Input e Output,  Next: Errori ed Eccezioni,  Prev: Moduli,  Up: Tutorial su Python

2.7 Input e Output
==================

Ci sono diversi modi per presentare l’output di un programma; i dati
possono essere stampati in una forma leggibile dall’uomo o scritti in un
file per un uso futuro.  Questo capitolo discuterà alcune delle
possibilità.

* Menu:

* Formattazione Avanzata dell’Output::
* Lettura e Scrittura di File::


File: python.info,  Node: Formattazione Avanzata dell’Output,  Next: Lettura e Scrittura di File,  Up: Input e Output

2.7.1 Formattazione Avanzata dell’Output
----------------------------------------

Finora abbiamo incontrato due modi di scrivere valori: 'espressioni' e
la funzione *note print(): 1177.  (Un terzo modo è utilizzare il metodo
*note write(): 2045. degli oggetti file; il file di output standard può
essere referenziato come ‘sys.stdout’.  Vedi la Libreria di Riferimento
per ulteriori informazioni a riguardo.)

Spesso desidererai avere più controllo sulla formattazione del tuo
output rispetto al semplice stampare valori separati da spazi.  Ci sono
diversi modi per formattare l’output.

   * Per usare *note formatted string literals: 2046, inizia una stringa
     con ‘f’ o ‘F’ prima del segno di apertura della virgoletta o della
     tripla virgoletta.  Dentro questa stringa, puoi scrivere
     un’espressione Python tra i caratteri ‘{’ e ‘}’, che possono
     riferirsi a variabili o valori letterali.

          >>> year = 2016
          >>> event = 'Referendum'
          >>> f'Results of the {year} {event}'
          'Results of the 2016 Referendum'

   * Il metodo *note str.format(): 834. delle stringhe richiede più
     sforzo manuale.  Utilizzerai comunque ‘{’ e ‘}’ per indicare dove
     una variabile sarà sostituita e potrai fornire direttive di
     formattazione dettagliate, ma dovrai anche fornire le informazioni
     da formattare.  Nel blocco di codice seguente ci sono due esempi di
     come formattare variabili:

          >>> yes_votes = 42_572_654
          >>> total_votes = 85_705_149
          >>> percentage = yes_votes / total_votes
          >>> '{:-9} YES votes  {:2.2%}'.format(yes_votes, percentage)
          ' 42572654 YES votes  49.67%'

     Nota come i ‘yes_votes’ sono riempiti con spazi e con un segno
     negativo solo per i numeri negativi.  L’esempio stampa anche
     ‘percentage’ moltiplicato per 100, con 2 cifre decimali e seguito
     da un segno di percentuale (vedi *note Format Specification
     Mini-Language: 4fa. per i dettagli).

   * Infine, puoi gestire tutte le stringhe da solo usando operazioni di
     slicing e concatenazione per creare qualsiasi layout tu possa
     immaginare.  Il tipo stringa ha alcuni metodi che eseguono
     operazioni utili per riempire le stringhe a una determinata
     larghezza di colonna.

Quando non hai bisogno di un output sofisticato ma vuoi solo una rapida
visualizzazione di alcune variabili per scopi di debug, puoi convertire
qualsiasi valore in una stringa con le funzioni *note repr(): 1c1. o
*note str(): 169.

La funzione *note str(): 169. è pensata per restituire rappresentazioni
di valori che siano abbastanza leggibili, mentre *note repr(): 1c1. è
pensata per generare rappresentazioni che possono essere lette
dall’interprete (o genererà una *note SyntaxError: 18e. se non esiste
una sintassi equivalente).  Per oggetti che non hanno una particolare
rappresentazione per il consumo umano, *note str(): 169. restituirà lo
stesso valore di *note repr(): 1c1.  Molti valori, come i numeri o
strutture come liste e dizionari, hanno la stessa rappresentazione
usando entrambe le funzioni.  Le stringhe, in particolare, hanno due
rappresentazioni distinte.

Alcuni esempi:

     >>> s = 'Hello, world.'
     >>> str(s)
     'Hello, world.'
     >>> repr(s)
     "'Hello, world.'"
     >>> str(1/7)
     '0.14285714285714285'
     >>> x = 10 * 3.25
     >>> y = 200 * 200
     >>> s = 'The value of x is ' + repr(x) + ', and y is ' + repr(y) + '...'
     >>> print(s)
     The value of x is 32.5, and y is 40000...
     >>> # The repr() of a string adds string quotes and backslashes:
     >>> hello = 'hello, world\n'
     >>> hellos = repr(hello)
     >>> print(hellos)
     'hello, world\n'
     >>> # The argument to repr() may be any Python object:
     >>> repr((x, y, ('spam', 'eggs')))
     "(32.5, 40000, ('spam', 'eggs'))"

The *note string: d8. module contains support for a simple templating
approach based upon regular expressions, via *note string.Template: 898.
This offers yet another way to substitute values into strings, using
placeholders like ‘$x’ and replacing them with values from a dictionary.
This syntax is easy to use, although it offers much less control for
formatting.

* Menu:

* Stringhe Formattate Letterali::
* Il Metodo String format(): Il Metodo String format.
* Formattazione Manuale delle Stringhe::
* Vecchia formattazione delle stringhe::


File: python.info,  Node: Stringhe Formattate Letterali,  Next: Il Metodo String format,  Up: Formattazione Avanzata dell’Output

2.7.1.1 Stringhe Formattate Letterali
.....................................

*note Formatted string literals: 19a. (anche dette f-strings per
brevità) ti permettono di includere il valore di espressioni Python
all’interno di una stringa, prefissando la stringa con ‘f’ o ‘F’ e
scrivendo espressioni come ‘{expression}’.

Uno specificatore di formato opzionale può seguire l’espressione.
Questo permette un maggiore controllo su come il valore viene
formattato.  Il seguente esempio arrotonda pi a tre cifre decimali:

     >>> import math
     >>> print(f'The value of pi is approximately {math.pi:.3f}.')
     The value of pi is approximately 3.142.

Passare un intero dopo ‘':'’ farà sì che quel campo abbia una larghezza
minima di un certo numero di caratteri.  Questo è utile per allineare le
colonne.

     >>> table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 7678}
     >>> for name, phone in table.items():
     ...     print(f'{name:10} ==> {phone:10d}')
     ...
     Sjoerd     ==>       4127
     Jack       ==>       4098
     Dcab       ==>       7678

Possono essere usati altri modificatori per convertire il valore prima
che venga formattato.  ‘'!a'’ applica *note ascii(): 15ed, ‘'!s'’
applica *note str(): 169, e ‘'!r'’ applica *note repr(): 1c1.:

     >>> animals = 'eels'
     >>> print(f'My hovercraft is full of {animals}.')
     My hovercraft is full of eels.
     >>> print(f'My hovercraft is full of {animals!r}.')
     My hovercraft is full of 'eels'.

Lo specificatore ‘=’ può essere usato per espandere un’espressione al
testo dell’espressione, un segno di uguale e poi la rappresentazione
dell’espressione valutata:

     >>> bugs = 'roaches'
     >>> count = 13
     >>> area = 'living room'
     >>> print(f'Debugging {bugs=} {count=} {area=}')
     Debugging bugs='roaches' count=13 area='living room'

Vedi *note self-documenting expressions: ba1. per maggiori informazioni
sullo specificatore ‘=’.  Per un riferimento su queste specifiche di
formato, consulta la guida di riferimento per *note Format Specification
Mini-Language: 4fa.


File: python.info,  Node: Il Metodo String format,  Next: Formattazione Manuale delle Stringhe,  Prev: Stringhe Formattate Letterali,  Up: Formattazione Avanzata dell’Output

2.7.1.2 Il Metodo String format()
.................................

L’uso di base del metodo *note str.format(): 834. sembra così:

     >>> print('We are the {} who say "{}!"'.format('knights', 'Ni'))
     We are the knights who say "Ni!"

Le parentesi e i caratteri al loro interno (chiamati campi di formato)
sono sostituiti dagli oggetti passati nel metodo *note str.format():
834.  Un numero nelle parentesi può essere usato per riferirsi alla
posizione dell’oggetto passato nel metodo *note str.format(): 834.

     >>> print('{0} and {1}'.format('spam', 'eggs'))
     spam and eggs
     >>> print('{1} and {0}'.format('spam', 'eggs'))
     eggs and spam

Se vengono utilizzati argomenti keyword nel metodo *note str.format():
834, i loro valori vengono referenziati usando il nome dell’argomento.

     >>> print('This {food} is {adjective}.'.format(
     ...       food='spam', adjective='absolutely horrible'))
     This spam is absolutely horrible.

Gli argomenti posizionali e keyword possono essere combinati
arbitrariamente:

     >>> print('The story of {0}, {1}, and {other}.'.format('Bill', 'Manfred',
     ...                                                    other='Georg'))
     The story of Bill, Manfred, and Georg.

Se hai una stringa di formato molto lunga che non vuoi dividere, sarebbe
utile poter riferire le variabili da formattare per nome invece che per
posizione.  Questo può essere fatto semplicemente passando il dizionario
e usando le parentesi quadre ‘'[]'’ per accedere alle chiavi.

     >>> table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 8637678}
     >>> print('Jack: {0[Jack]:d}; Sjoerd: {0[Sjoerd]:d}; '
     ...       'Dcab: {0[Dcab]:d}'.format(table))
     Jack: 4098; Sjoerd: 4127; Dcab: 8637678

Questo può essere fatto anche passando il dizionario ‘table’ come
argomenti keyword usando la notazione ‘**’.

     >>> table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 8637678}
     >>> print('Jack: {Jack:d}; Sjoerd: {Sjoerd:d}; Dcab: {Dcab:d}'.format(**table))
     Jack: 4098; Sjoerd: 4127; Dcab: 8637678

Questo è particolarmente utile in combinazione con la funzione built-in
*note vars(): 1e0b, che restituisce un dizionario contenente tutte le
variabili locali:

     >>> table = {k: str(v) for k, v in vars().items()}
     >>> message = " ".join([f'{k}: ' + '{' + k +'};' for k in table.keys()])
     >>> print(message.format(**table))
     __name__: __main__; __doc__: None; __package__: None; __loader__: ...

Ad esempio, le seguenti righe producono un insieme di colonne
ordinatamente allineate che danno interi e loro quadrati e cubi:

     >>> for x in range(1, 11):
     ...     print('{0:2d} {1:3d} {2:4d}'.format(x, x*x, x*x*x))
     ...
      1   1    1
      2   4    8
      3   9   27
      4  16   64
      5  25  125
      6  36  216
      7  49  343
      8  64  512
      9  81  729
     10 100 1000

Per una panoramica completa della formattazione delle stringhe con *note
str.format(): 834, vedi *note Format String Syntax: 15a3.


File: python.info,  Node: Formattazione Manuale delle Stringhe,  Next: Vecchia formattazione delle stringhe,  Prev: Il Metodo String format,  Up: Formattazione Avanzata dell’Output

2.7.1.3 Formattazione Manuale delle Stringhe
............................................

Ecco la stessa tabella di quadrati e cubi, formattata manualmente:

     >>> for x in range(1, 11):
     ...     print(repr(x).rjust(2), repr(x*x).rjust(3), end=' ')
     ...     # Note use of 'end' on previous line
     ...     print(repr(x*x*x).rjust(4))
     ...
      1   1    1
      2   4    8
      3   9   27
      4  16   64
      5  25  125
      6  36  216
      7  49  343
      8  64  512
      9  81  729
     10 100 1000

(Nota che l’unico spazio tra ogni colonna è stato aggiunto dal modo in
cui funziona *note print(): 1177.: aggiunge sempre spazi tra i suoi
argomenti.)

Il metodo *note str.rjust(): 204b. degli oggetti stringa giustifica a
destra una stringa in un campo di una data larghezza riempiendola con
spazi sulla sinistra.  Esistono metodi simili *note str.ljust(): 204c. e
*note str.center(): 204d.  Questi metodi non scrivono nulla,
restituiranno solo una nuova stringa.  Se la stringa di input è troppo
lunga, non viene troncata, ma restituita invariata; questo comprometterà
l’allineamento delle colonne ma di solito è meglio dell’alternativa, che
sarebbe mentire su un valore.  (Se desideri davvero la troncatura, puoi
sempre aggiungere un’operazione di slicing, come in ‘x.ljust(n)[:n]’.)

C’è un altro metodo, *note str.zfill(): 16b9, che riempie una stringa
numerica a sinistra con zeri.  Comprende i segni più e meno:

     >>> '12'.zfill(5)
     '00012'
     >>> '-3.14'.zfill(7)
     '-003.14'
     >>> '3.14159265359'.zfill(5)
     '3.14159265359'


File: python.info,  Node: Vecchia formattazione delle stringhe,  Prev: Formattazione Manuale delle Stringhe,  Up: Formattazione Avanzata dell’Output

2.7.1.4 Vecchia formattazione delle stringhe
............................................

The % operator (modulo) can also be used for string formatting.  Given
‘format % values’ (where 'format' is a string), ‘%’ conversion
specifications in 'format' are replaced with zero or more elements of
'values'.  This operation is commonly known as string interpolation.
For example:

     >>> import math
     >>> print('The value of pi is approximately %5.3f.' % math.pi)
     The value of pi is approximately 3.142.

Maggiori informazioni possono essere trovate nella sezione *note
Formattazione delle stringhe in stile printf: 8dc.


File: python.info,  Node: Lettura e Scrittura di File,  Prev: Formattazione Avanzata dell’Output,  Up: Input e Output

2.7.2 Lettura e Scrittura di File
---------------------------------

*note open(): 316. restituisce un *note file object: 13cb, ed è più
comunemente usato con due argomenti posizionali e uno keyword:
‘open(filename, mode, encoding=None)’

     >>> f = open('workfile', 'w', encoding="utf-8")

Il primo argomento è una stringa che contiene il nome del file.  Il
secondo argomento è un’altra stringa che contiene alcuni caratteri che
descrivono il modo in cui il file verrà utilizzato.  'mode' può essere
‘'r'’ quando il file verrà solo letto, ‘'w'’ per solo scrivere (un file
esistente con lo stesso nome verrà cancellato), e ‘'a'’ apre il file per
l’aggiunta dati; qualsiasi dato scritto nel file viene automaticamente
aggiunto alla fine.  ‘'r+'’ apre il file per sia lettura che scrittura.
L’argomento 'mode' è opzionale; ‘'r'’ sarà assunto se omesso.

Normalmente, i file vengono aperti in 'text mode', ciò significa che
leggi e scrivi stringhe dal e nel file, che sono codificate in una
specifica 'encoding'.  Se 'encoding' non è specificato, il valore
predefinito dipende dal sistema (vedi *note open(): 316.).  Poiché UTF-8
è lo standard de facto moderno, ‘encoding="utf-8"’ è raccomandato a meno
che non si sappia che è necessario utilizzare una diversa codifica.
Aggiungendo una ‘'b'’ al mode, si apre il file in 'binary mode'.  I dati
in modalità binaria sono letti e scritti come oggetti *note bytes: 192.
Non puoi specificare 'encoding' quando apri file in modalità binaria.

In modalità testo, il valore predefinito durante la lettura è convertire
i terminatori di riga specifici della piattaforma (‘\n’ su Unix, ‘\r\n’
su Windows) in solo ‘\n’.  Quando si scrive in modalità testo, il valore
predefinito è convertire le occorrenze di ‘\n’ nei terminatori specifici
della piattaforma.  Questa modifica dietro le quinte ai dati del file va
bene per i file di testo, ma corromperà i dati binari come quelli nei
file ‘JPEG’ o ‘EXE’.  Fai molta attenzione a usare modalità binaria
quando leggi e scrivi tali file.

È buona pratica usare la keyword *note with: 186. quando si lavora con
oggetti file.  Il vantaggio è che il file viene chiuso correttamente
dopo che la sua suite finisce, anche se viene generata un’eccezione a un
certo punto.  Usare ‘with’ è anche molto più breve che scrivere blocchi
equivalenti *note try: 8f9.-*note finally: 1b0.:

     >>> with open('workfile', encoding="utf-8") as f:
     ...     read_data = f.read()

     >>> # We can check that the file has been automatically closed.
     >>> f.closed
     True

Se non stai usando la keyword *note with: 186, allora dovresti chiamare
‘f.close()’ per chiudere il file e liberare immediatamente qualsiasi
risorsa di sistema utilizzata da esso.

     Avvertimento: Chiamare ‘f.write()’ senza usare la keyword ‘with’ o
     chiamare ‘f.close()’ 'potrebbe' risultare nel fatto che gli
     argomenti di ‘f.write()’ non vengano completamente scritti sul
     disco, anche se il programma termina con successo.

Dopo che un oggetto file è stato chiuso, sia tramite un’istruzione *note
with: 186, sia chiamando ‘f.close()’, i tentativi di utilizzare
l’oggetto file falliranno automaticamente.

     >>> f.close()
     >>> f.read()
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     ValueError: I/O operation on closed file.

* Menu:

* Metodi degli Oggetti File::
* Salvare dati strutturati con json::


File: python.info,  Node: Metodi degli Oggetti File,  Next: Salvare dati strutturati con json,  Up: Lettura e Scrittura di File

2.7.2.1 Metodi degli Oggetti File
.................................

Gli altri esempi in questa sezione assumeranno che un oggetto file
chiamato ‘f’ sia già stato creato.

Per leggere i contenuti di un file, chiama ‘f.read(size)’, che legge una
certa quantità di dati e li restituisce come una stringa (in modalità
testo) o un oggetto bytes (in modalità binaria).  'size' è un argomento
numerico opzionale.  Quando 'size' è omesso o negativo, verranno letti e
restituiti tutti i contenuti del file; è un tuo problema se il file è
due volte più grande della memoria del tuo computer.  Altrimenti, al
massimo 'size' caratteri (in modalità testo) o 'size' byte (in modalità
binaria) vengono letti e restituiti.  Se la fine del file è stata
raggiunta, ‘f.read()’ restituirà una stringa vuota (‘''’).

     >>> f.read()
     'This is the entire file.\n'
     >>> f.read()
     ''

‘f.readline()’ legge una singola riga dal file; un carattere di newline
(‘\n’) viene lasciato alla fine della stringa e viene omesso solo
sull’ultima riga del file se il file non termina con un newline.  Questo
rende il valore di ritorno non ambiguo; se ‘f.readline()’ restituisce
una stringa vuota, la fine del file è stata raggiunta, mentre una linea
vuota è rappresentata da ‘'\n'’, una stringa contenente solo un newline.

     >>> f.readline()
     'This is the first line of the file.\n'
     >>> f.readline()
     'Second line of the file\n'
     >>> f.readline()
     ''

Per leggere le righe da un file, puoi iterare sull’oggetto file.  Questo
è efficiente in termini di memoria, veloce e porta a un codice semplice:

     >>> for line in f:
     ...     print(line, end='')
     ...
     This is the first line of the file.
     Second line of the file

Se vuoi leggere tutte le righe di un file in una lista puoi anche usare
‘list(f)’ o ‘f.readlines()’.

‘f.write(string)’ scrive i contenuti di 'string' nel file, restituendo
il numero di caratteri scritti.

     >>> f.write('This is a test\n')
     15

Altri tipi di oggetti devono essere convertiti – o in una stringa (in
modalità testo) o in un oggetto bytes (in modalità binaria) – prima di
scriverli:

     >>> value = ('the answer', 42)
     >>> s = str(value)  # convert the tuple to string
     >>> f.write(s)
     18

‘f.tell()’ restituisce un intero che indica la posizione corrente
dell’oggetto file nel file, rappresentata come numero di byte
dall’inizio del file quando in modalità binaria e un numero opaco quando
in modalità testo.

Per cambiare la posizione dell’oggetto file, usa ‘f.seek(offset,
whence)’.  La posizione è calcolata sommando 'offset' a un punto di
riferimento; il punto di riferimento è selezionato dall’argomento
'whence'.  Un valore 'whence' di 0 misura dall’inizio del file, 1 usa la
posizione corrente del file, e 2 usa la fine del file come punto di
riferimento.  'whence' può essere omesso e predefinito a 0, utilizzando
l’inizio del file come punto di riferimento.

     >>> f = open('workfile', 'rb+')
     >>> f.write(b'0123456789abcdef')
     16
     >>> f.seek(5)      # Go to the 6th byte in the file
     5
     >>> f.read(1)
     b'5'
     >>> f.seek(-3, 2)  # Go to the 3rd byte before the end
     13
     >>> f.read(1)
     b'd'

Nei file di testo (quelli aperti senza una ‘b’ nella stringa di
modalità), sono consentiti solo i seek relativi all’inizio del file (con
l’eccezione del seek alla fine del file con ‘seek(0, 2)’) e gli unici
valori 'offset' validi sono quelli restituiti da ‘f.tell()’, o zero.
Qualsiasi altro valore 'offset' produce un comportamento non definito.

Gli oggetti file hanno alcuni metodi aggiuntivi, come *note isatty():
2053. e *note truncate(): 1518. che sono meno frequentemente usati;
consulta la Libreria di Riferimento per una guida completa agli oggetti
file.


File: python.info,  Node: Salvare dati strutturati con json,  Prev: Metodi degli Oggetti File,  Up: Lettura e Scrittura di File

2.7.2.2 Salvare dati strutturati con ‘json’
...........................................

Le stringhe possono essere facilmente scritte su e lette da un file.  I
numeri richiedono un po” più di sforzo, poiché il metodo *note read():
2056. restituisce solo stringhe, che dovranno essere passate a una
funzione come *note int(): 19b, che prende una stringa come ‘'123'’ e
restituisce il suo valore numerico 123.  Quando vuoi salvare tipi di
dati più complessi come liste annidate e dizionari, il parsing e la
serializzazione manuale diventano complicati.

Piuttosto che avere utenti che scrivono e fanno debug costantemente di
codice per salvare tipi di dati complicati nei file, Python ti permette
di usare il popolare formato di interscambio dati chiamato JSON
(JavaScript Object Notation)(1).  Il modulo standard chiamato *note
json: 86. può prendere gerarchie di dati Python e convertirle in
rappresentazioni di stringhe; questo processo è chiamato
'serializzazione'.  Ricostruire i dati dalla rappresentazione di stringa
è chiamato 'deserializzazione'.  Tra la serializzazione e la
deserializzazione, la stringa che rappresenta l’oggetto può essere stata
memorizzata in un file o dato, o inviata su una connessione di rete a
una macchina lontana.

     Nota: Il formato JSON è comunemente usato dalle applicazioni
     moderne per permettere lo scambio di dati.  Molti programmatori
     sono già familiari con esso, il che lo rende una buona scelta per
     l’interoperabilità.

Se hai un oggetto ‘x’, puoi visualizzare la sua rappresentazione JSON
della stringa con una semplice riga di codice:

     >>> import json
     >>> x = [1, 'simple', 'list']
     >>> json.dumps(x)
     '[1, "simple", "list"]'

Un’altra variante della funzione *note dumps(): f43, chiamata *note
dump(): f42, semplicemente serializza l’oggetto in un oggetto *note text
file: 2057.  Quindi se ‘f’ è un oggetto *note text file: 2057. aperto
per la scrittura, possiamo fare questo:

     json.dump(x, f)

Per decodificare l’oggetto di nuovo, se ‘f’ è un oggetto *note binary
file: 2058. o *note text file: 2057. che è stato aperto per la lettura:

     x = json.load(f)

     Nota: I file JSON devono essere codificati in UTF-8.  Usa
     ‘encoding="utf-8"’ quando apri il file JSON come *note text file:
     2057. sia per la lettura che per la scrittura.

Questa semplice tecnica di serializzazione può gestire liste e
dizionari, ma serializzare istanze di classi arbitrari in JSON richiede
un po” di sforzo extra.  Il riferimento per il modulo *note json: 86.
contiene una spiegazione di questo.

Vedi anche
..........

*note pickle: ab. - il modulo pickle

Contrariamente a *note JSON: 2055, 'pickle' è un protocollo che permette
la serializzazione di oggetti Python arbitrariamente complessi.  Come
tale, è specifico per Python e non può essere usato

   ---------- Footnotes ----------

   (1) https://json.org


File: python.info,  Node: Errori ed Eccezioni,  Next: Classi,  Prev: Input e Output,  Up: Tutorial su Python

2.8 Errori ed Eccezioni
=======================

Finora i messaggi di errore sono stati solo menzionati, ma se hai
provato gli esempi probabilmente ne hai visti alcuni.  Ci sono (almeno)
due tipi distinti di errori: 'errori di sintassi' ed 'eccezioni'.

* Menu:

* Errori di Sintassi::
* Eccezioni::
* Gestione delle Eccezioni::
* Sollevare Eccezioni::
* Collegamento delle Eccezioni::
* Eccezioni Definite dall’Utente::
* Definizione di Azioni di Pulizia::
* Azioni di Pulizia Predefinite::
* Sollevare e Gestire Eccezioni Multiple e Non Correlate::
* Arricchire le Eccezioni con Note::


File: python.info,  Node: Errori di Sintassi,  Next: Eccezioni,  Up: Errori ed Eccezioni

2.8.1 Errori di Sintassi
------------------------

Gli errori di sintassi, noti anche come errori di parsing, sono forse il
tipo più comune di reclamo che si ottiene mentre si sta ancora imparando
Python:

     >>> while True print('Hello world')
       File "<stdin>", line 1
         while True print('Hello world')
                    ^^^^^
     SyntaxError: invalid syntax

The parser repeats the offending line and displays little arrows
pointing at the place where the error was detected.  Note that this is
not always the place that needs to be fixed.  In the example, the error
is detected at the function *note print(): 1177, since a colon (‘':'’)
is missing just before it.

The file name (‘<stdin>’ in our example) and line number are printed so
you know where to look in case the input came from a file.


File: python.info,  Node: Eccezioni,  Next: Gestione delle Eccezioni,  Prev: Errori di Sintassi,  Up: Errori ed Eccezioni

2.8.2 Eccezioni
---------------

Anche se un’istruzione o un’espressione è sintatticamente corretta, può
causare un errore quando si tenta di eseguirla.  Gli errori rilevati
durante l’esecuzione sono chiamati 'eccezioni' e non sono
incondizionatamente fatali: imparerai presto come gestirli nei programmi
Python.  La maggior parte delle eccezioni non viene gestita dai
programmi, tuttavia, e si traduce in messaggi di errore come mostrato
qui:

     >>> 10 * (1/0)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
         10 * (1/0)
               ~^~
     ZeroDivisionError: division by zero
     >>> 4 + spam*3
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
         4 + spam*3
             ^^^^
     NameError: name 'spam' is not defined
     >>> '2' + 2
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
         '2' + 2
         ~~~~^~~
     TypeError: can only concatenate str (not "int") to str

L’ultima linea del messaggio di errore indica cosa è successo.  Le
eccezioni hanno tipi diversi, e il tipo viene stampato come parte del
messaggio: i tipi nell’esempio sono *note ZeroDivisionError: b41, *note
NameError: 452. e *note TypeError: 198.  La stringa stampata come tipo
di eccezione è il nome dell’eccezione built-in che si è verificata.
Questo è vero per tutte le eccezioni built-in, ma non deve essere vero
per le eccezioni definite dall’utente (anche se è una convenzione
utile).  I nomi delle eccezioni standard sono identificatori built-in
(non parole chiave riservate).

La restante parte della linea fornisce dettagli basati sul tipo di
eccezione e su cosa l’ha causata.

La parte precedente del messaggio di errore mostra il contesto in cui si
è verificata l’eccezione, sotto forma di traccia dello stack.  In
generale, contiene una traccia dello stack che elenca le linee di
origine; tuttavia, non visualizzerà linee lette dall’input standard.

*note Built-in Exceptions: 1c0f. elenca le eccezioni built-in e i loro
significati.


File: python.info,  Node: Gestione delle Eccezioni,  Next: Sollevare Eccezioni,  Prev: Eccezioni,  Up: Errori ed Eccezioni

2.8.3 Gestione delle Eccezioni
------------------------------

È possibile scrivere programmi che gestiscono eccezioni selezionate.
Guarda il seguente esempio, che chiede all’utente un input finché non
viene inserito un intero valido, ma consente all’utente di interrompere
il programma (usando ‘Control’-‘C’ o cosa supporta il sistema
operativo); nota che un’interruzione generata dall’utente è segnalata
sollevando l’eccezione *note KeyboardInterrupt: bc7.

     >>> while True:
     ...     try:
     ...         x = int(input("Please enter a number: "))
     ...         break
     ...     except ValueError:
     ...         print("Oops!  That was no valid number.  Try again...")
     ...

L’istruzione *note try: 8f9. funziona come segue.

   * Per prima cosa, viene eseguita la 'clausola try' (l’istruzione o le
     istruzioni tra le parole chiave *note try: 8f9. e *note except:
     1ab.).

   * Se non si verifica alcuna eccezione, la 'clausola except' viene
     saltata e l’esecuzione dell’istruzione *note try: 8f9. è terminata.

   * Se si verifica un’eccezione durante l’esecuzione della clausola
     *note try: 8f9, il resto della clausola viene saltato.  Poi, se il
     suo tipo corrisponde all’eccezione nominata dopo la parola chiave
     *note except: 1ab, viene eseguita la 'clausola except', e quindi
     l’esecuzione continua dopo il blocco try/except.

   * Se si verifica un’eccezione che non corrisponde all’eccezione
     nominata nella 'clausola except', viene passata alle istruzioni
     *note try: 8f9. esterne; se non viene trovato alcun gestore, è un”
     'eccezione non gestita' e l’esecuzione si interrompe con un
     messaggio di errore.

Un’istruzione *note try: 8f9. può avere più di una 'clausola except',
per specificare gestori per diverse eccezioni.  Al massimo verrà
eseguito un gestore.  I gestori gestiscono solo le eccezioni che si
verificano nella corrispondente 'clausola try', non in altri gestori
della stessa istruzione ‘try’.  Una 'clausola except' può nominare più
eccezioni come una tupla tra parentesi, per esempio:

     ... except (RuntimeError, TypeError, NameError):
     ...     pass

Una classe in una clausola *note except: 1ab. corrisponde a eccezioni
che sono istanze della classe stessa o di una delle sue classi derivate
(ma non viceversa — una 'clausola except' che elenca una classe derivata
non corrisponde a istanze delle sue classi base).  Ad esempio, il
seguente codice stamperà B, C, D in quell’ordine:

     class B(Exception):
         pass

     class C(B):
         pass

     class D(C):
         pass

     for cls in [B, C, D]:
         try:
             raise cls()
         except D:
             print("D")
         except C:
             print("C")
         except B:
             print("B")

Nota che se le 'clausole except' fossero invertite (con ‘except B’
prima), avrebbero stampato B, B, B — la prima 'clausola except' che
corrisponde viene attivata.

Quando si verifica un’eccezione, essa può avere valori associati, noti
anche come 'argomenti' dell’eccezione.  La presenza e il tipo degli
argomenti dipendono dal tipo di eccezione.

La 'clausola except' può specificare una variabile dopo il nome
dell’eccezione.  La variabile è legata all’istanza dell’eccezione che
tipicamente ha un attributo ‘args’ che memorizza gli argomenti.  Per
comodità, i tipi di eccezioni built-in definiscono *note __str__(): 831.
per stampare tutti gli argomenti senza accedere esplicitamente a
‘.args’.

     >>> try:
     ...     raise Exception('spam', 'eggs')
     ... except Exception as inst:
     ...     print(type(inst))    # the exception type
     ...     print(inst.args)     # arguments stored in .args
     ...     print(inst)          # __str__ allows args to be printed directly,
     ...                          # but may be overridden in exception subclasses
     ...     x, y = inst.args     # unpack args
     ...     print('x =', x)
     ...     print('y =', y)
     ...
     <class 'Exception'>
     ('spam', 'eggs')
     ('spam', 'eggs')
     x = spam
     y = eggs

L’output di *note __str__(): 831. dell’eccezione viene stampato come
l’ultima parte (“dettaglio”) del messaggio per le eccezioni non gestite.

*note BaseException: 7d8. è la classe base comune di tutte le eccezioni.
Uno dei suoi sottosclassi, *note Exception: bcf, è la classe base di
tutte le eccezioni non fatali.  Le eccezioni che non sono sottoclassi di
*note Exception: bcf. non sono tipicamente gestite, perché vengono
utilizzate per indicare che il programma dovrebbe terminare.  Queste
includono *note SystemExit: f3e. che è sollevata da *note sys.exit():
277. e *note KeyboardInterrupt: bc7. che è sollevata quando un utente
desidera interrompere il programma.

*note Exception: bcf. può essere utilizzata come un jolly che cattura
(quasi) tutto.  Tuttavia, è buona pratica essere il più specifici
possibile con i tipi di eccezioni che intendiamo gestire, e permettere a
qualsiasi eccezione inattesa di propagarsi.

Il pattern più comune per la gestione di *note Exception: bcf. è
stamparla o registrarla e poi rilanciarla (consentendo a un chiamante di
gestire l’eccezione altrettanto):

     import sys

     try:
         f = open('myfile.txt')
         s = f.readline()
         i = int(s.strip())
     except OSError as err:
         print("OS error:", err)
     except ValueError:
         print("Could not convert data to an integer.")
     except Exception as err:
         print(f"Unexpected {err=}, {type(err)=}")
         raise

L’istruzione *note try: 8f9. … *note except: 1ab. ha una 'clausola else'
opzionale, che, quando presente, deve seguire tutte le 'clausole
except'.  È utile per il codice che deve essere eseguito se la 'clausola
try' non solleva un’eccezione.  Per esempio:

     for arg in sys.argv[1:]:
         try:
             f = open(arg, 'r')
         except OSError:
             print('cannot open', arg)
         else:
             print(arg, 'has', len(f.readlines()), 'lines')
             f.close()

L’uso della clausola ‘else’ è migliore che aggiungere codice ulteriore
alla clausola *note try: 8f9. perché evita di catturare accidentalmente
un’eccezione che non è stata sollevata dal codice protetto
dall’istruzione ‘try’ … ‘except’.

I gestori delle eccezioni non gestiscono solo le eccezioni che si
verificano immediatamente nella 'clausola try', ma anche quelle che si
verificano all’interno delle funzioni che vengono chiamate (anche
indirettamente) nella 'clausola try'.  Per esempio:

     >>> def this_fails():
     ...     x = 1/0
     ...
     >>> try:
     ...     this_fails()
     ... except ZeroDivisionError as err:
     ...     print('Handling run-time error:', err)
     ...
     Handling run-time error: division by zero


File: python.info,  Node: Sollevare Eccezioni,  Next: Collegamento delle Eccezioni,  Prev: Gestione delle Eccezioni,  Up: Errori ed Eccezioni

2.8.4 Sollevare Eccezioni
-------------------------

L’istruzione *note raise: 804. permette al programmatore di forzare il
verificarsi di una specifica eccezione.  Per esempio:

     >>> raise NameError('HiThere')
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
         raise NameError('HiThere')
     NameError: HiThere

L’unico argomento per *note raise: 804. indica l’eccezione da sollevare.
Questo deve essere o un’istanza di eccezione o una classe di eccezione
(una classe che deriva da *note BaseException: 7d8, come *note
Exception: bcf. o una delle sue sottoclassi).  Se viene passata una
classe di eccezione, verrà istanziata implicitamente chiamando il suo
costruttore senza argomenti:

     raise ValueError  # shorthand for 'raise ValueError()'

Se è necessario determinare se un’eccezione è stata sollevata ma non si
intende gestirla, una forma più semplice dell’istruzione *note raise:
804. consente di rilanciare l’eccezione:

     >>> try:
     ...     raise NameError('HiThere')
     ... except NameError:
     ...     print('An exception flew by!')
     ...     raise
     ...
     An exception flew by!
     Traceback (most recent call last):
       File "<stdin>", line 2, in <module>
         raise NameError('HiThere')
     NameError: HiThere


File: python.info,  Node: Collegamento delle Eccezioni,  Next: Eccezioni Definite dall’Utente,  Prev: Sollevare Eccezioni,  Up: Errori ed Eccezioni

2.8.5 Collegamento delle Eccezioni
----------------------------------

Se si verifica un’eccezione non gestita all’interno di una sezione *note
except: 1ab, avrà l’eccezione che viene gestita allegata e inclusa nel
messaggio di errore:

     >>> try:
     ...     open("database.sqlite")
     ... except OSError:
     ...     raise RuntimeError("unable to handle error")
     ...
     Traceback (most recent call last):
       File "<stdin>", line 2, in <module>
         open("database.sqlite")
         ~~~~^^^^^^^^^^^^^^^^^^^
     FileNotFoundError: [Errno 2] No such file or directory: 'database.sqlite'

     During handling of the above exception, another exception occurred:

     Traceback (most recent call last):
       File "<stdin>", line 4, in <module>
         raise RuntimeError("unable to handle error")
     RuntimeError: unable to handle error

Per indicare che un’eccezione è una diretta conseguenza di un’altra,
l’istruzione *note raise: 804. permette una clausola opzionale *note
from: 804.:

     # exc must be exception instance or None.
     raise RuntimeError from exc

Questo può essere utile quando si stanno trasformando le eccezioni.  Per
esempio:

     >>> def func():
     ...     raise ConnectionError
     ...
     >>> try:
     ...     func()
     ... except ConnectionError as exc:
     ...     raise RuntimeError('Failed to open database') from exc
     ...
     Traceback (most recent call last):
       File "<stdin>", line 2, in <module>
         func()
         ~~~~^^
       File "<stdin>", line 2, in func
     ConnectionError

     The above exception was the direct cause of the following exception:

     Traceback (most recent call last):
       File "<stdin>", line 4, in <module>
         raise RuntimeError('Failed to open database') from exc
     RuntimeError: Failed to open database

Consente anche di disabilitare il collegamento automatico delle
eccezioni utilizzando l’idioma ‘from None’:

     >>> try:
     ...     open('database.sqlite')
     ... except OSError:
     ...     raise RuntimeError from None
     ...
     Traceback (most recent call last):
       File "<stdin>", line 4, in <module>
         raise RuntimeError from None
     RuntimeError

Per ulteriori informazioni sulla meccanica del collegamento, vedi *note
Built-in Exceptions: 1c0f.


File: python.info,  Node: Eccezioni Definite dall’Utente,  Next: Definizione di Azioni di Pulizia,  Prev: Collegamento delle Eccezioni,  Up: Errori ed Eccezioni

2.8.6 Eccezioni Definite dall’Utente
------------------------------------

I programmi possono nominare le proprie eccezioni creando una nuova
classe di eccezione (vedi *note Classi: 1feb. per ulteriori informazioni
sulle classi Python).  Le eccezioni devono essere tipicamente derivate
dalla classe *note Exception: bcf, direttamente o indirettamente.

Si possono definire classi di eccezione che fanno qualsiasi cosa possa
fare qualsiasi altra classe, ma di solito vengono mantenute semplici,
spesso offrendo solo un numero di attributi che consentono di estrarre
informazioni sull’errore dai gestori per l’eccezione.

La maggior parte delle eccezioni è definita con nomi che terminano in
«Error», simili alla denominazione delle eccezioni standard.

Molti moduli standard definiscono le proprie eccezioni per segnalare
errori che possono verificarsi nelle funzioni che definiscono.


File: python.info,  Node: Definizione di Azioni di Pulizia,  Next: Azioni di Pulizia Predefinite,  Prev: Eccezioni Definite dall’Utente,  Up: Errori ed Eccezioni

2.8.7 Definizione di Azioni di Pulizia
--------------------------------------

L’istruzione *note try: 8f9. ha un’altra clausola opzionale che è intesa
a definire azioni di pulizia che devono essere eseguite in tutte le
circostanze.  Per esempio:

     >>> try:
     ...     raise KeyboardInterrupt
     ... finally:
     ...     print('Goodbye, world!')
     ...
     Goodbye, world!
     Traceback (most recent call last):
       File "<stdin>", line 2, in <module>
         raise KeyboardInterrupt
     KeyboardInterrupt

Se è presente una clausola *note finally: 1b0, la clausola ‘finally’
verrà eseguita come ultimo compito prima che l’istruzione *note try:
8f9. completi.  La clausola ‘finally’ viene eseguita sia che
l’istruzione ‘try’ produca o meno un’eccezione.  I seguenti punti
discutono casi più complessi quando si verifica un’eccezione:

   * Se si verifica un’eccezione durante l’esecuzione della clausola
     ‘try’, l’eccezione può essere gestita da una clausola *note except:
     1ab.  Se l’eccezione non è gestita da una clausola ‘except’,
     l’eccezione viene rilanciata dopo che la clausola ‘finally’ è stata
     eseguita.

   * Un’eccezione potrebbe verificarsi durante l’esecuzione di una
     clausola ‘except’ o ‘else’.  Anche in questo caso, l’eccezione
     viene rilanciata dopo che la clausola ‘finally’ è stata eseguita.

   * If the ‘finally’ clause executes a *note break: 17f, *note
     continue: 180. or *note return: 1af. statement, exceptions are not
     re-raised.  This can be confusing and is therefore discouraged.
     From version 3.14 the compiler emits a *note SyntaxWarning: 1ae.
     for it (see PEP 765(1)).

   * Se l’istruzione ‘try’ raggiunge un’istruzione *note break: 17f,
     *note continue: 180. o *note return: 1af, la clausola ‘finally’
     verrà eseguita appena prima dell’esecuzione dell’istruzione
     ‘break’, ‘continue’ o ‘return’.

   * If a ‘finally’ clause includes a ‘return’ statement, the returned
     value will be the one from the ‘finally’ clause’s ‘return’
     statement, not the value from the ‘try’ clause’s ‘return’
     statement.  This can be confusing and is therefore discouraged.
     From version 3.14 the compiler emits a *note SyntaxWarning: 1ae.
     for it (see PEP 765(2)).

Per esempio:

     >>> def bool_return():
     ...     try:
     ...         return True
     ...     finally:
     ...         return False
     ...
     >>> bool_return()
     False

Un esempio più complicato:

     >>> def divide(x, y):
     ...     try:
     ...         result = x / y
     ...     except ZeroDivisionError:
     ...         print("division by zero!")
     ...     else:
     ...         print("result is", result)
     ...     finally:
     ...         print("executing finally clause")
     ...
     >>> divide(2, 1)
     result is 2.0
     executing finally clause
     >>> divide(2, 0)
     division by zero!
     executing finally clause
     >>> divide("2", "1")
     executing finally clause
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
         divide("2", "1")
         ~~~~~~^^^^^^^^^^
       File "<stdin>", line 3, in divide
         result = x / y
                  ~~^~~
     TypeError: unsupported operand type(s) for /: 'str' and 'str'

Come puoi vedere, la clausola *note finally: 1b0. viene eseguita in ogni
caso.  L’eccezione *note TypeError: 198. sollevata dividendo due
stringhe non è gestita dalla clausola *note except: 1ab. e quindi
rilanciata dopo che la clausola ‘finally’ è stata eseguita.

Nelle applicazioni del mondo reale, la clausola *note finally: 1b0. è
utile per rilasciare risorse esterne (come file o connessioni di rete),
indipendentemente dal successo dell’uso delle risorse.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0765/

   (2) https://peps.python.org/pep-0765/


File: python.info,  Node: Azioni di Pulizia Predefinite,  Next: Sollevare e Gestire Eccezioni Multiple e Non Correlate,  Prev: Definizione di Azioni di Pulizia,  Up: Errori ed Eccezioni

2.8.8 Azioni di Pulizia Predefinite
-----------------------------------

Alcuni oggetti definiscono azioni di pulizia standard da intraprendere
quando l’oggetto non è più necessario, indipendentemente dal fatto che
l’operazione che usa l’oggetto sia riuscita o fallita.  Guarda il
seguente esempio, che tenta di aprire un file e stampare il suo
contenuto sullo schermo.

     for line in open("myfile.txt"):
         print(line, end="")

Il problema con questo codice è che lascia il file aperto per un tempo
indeterminato dopo che questa parte del codice ha terminato
l’esecuzione.  Questo non è un problema negli script semplici, ma può
essere un problema per applicazioni più grandi.  L’istruzione *note
with: 186. consente agli oggetti come i file di essere usati in modo
tale da garantire che siano sempre puliti rapidamente e correttamente.

     with open("myfile.txt") as f:
         for line in f:
             print(line, end="")

Dopo che l’istruzione è stata eseguita, il file 'f' è sempre chiuso,
anche se si è verificato un problema durante l’elaborazione delle linee.
Gli oggetti che, come i file, forniscono azioni di pulizia predefinite
indicheranno ciò nella loro documentazione.


File: python.info,  Node: Sollevare e Gestire Eccezioni Multiple e Non Correlate,  Next: Arricchire le Eccezioni con Note,  Prev: Azioni di Pulizia Predefinite,  Up: Errori ed Eccezioni

2.8.9 Sollevare e Gestire Eccezioni Multiple e Non Correlate
------------------------------------------------------------

Ci sono situazioni in cui è necessario segnalare diverse eccezioni che
si sono verificate.  Questo è spesso il caso nei framework di
concorrenza, quando diversi compiti possono aver fallito in parallelo,
ma ci sono anche altri casi d’uso in cui è desiderabile continuare
l’esecuzione e raccogliere più errori piuttosto che sollevare la prima
eccezione.

L’eccezione built-in *note ExceptionGroup: 4d3. avvolge una lista di
istanze di eccezione in modo tale che possano essere sollevate insieme.
È un’eccezione a sé stante, quindi può essere catturata come qualsiasi
altra eccezione.

     >>> def f():
     ...     excs = [OSError('error 1'), SystemError('error 2')]
     ...     raise ExceptionGroup('there were problems', excs)
     ...
     >>> f()
       + Exception Group Traceback (most recent call last):
       |   File "<stdin>", line 1, in <module>
       |     f()
       |     ~^^
       |   File "<stdin>", line 3, in f
       |     raise ExceptionGroup('there were problems', excs)
       | ExceptionGroup: there were problems (2 sub-exceptions)
       +-+---------------- 1 ----------------
         | OSError: error 1
         +---------------- 2 ----------------
         | SystemError: error 2
         +------------------------------------
     >>> try:
     ...     f()
     ... except Exception as e:
     ...     print(f'caught {type(e)}: e')
     ...
     caught <class 'ExceptionGroup'>: e
     >>>

Usando ‘except*’ invece di ‘except’, possiamo gestire selettivamente
solo le eccezioni nel gruppo che corrispondono a un certo tipo.
Nell’esempio seguente, che mostra un gruppo di eccezioni annidato, ogni
clausola ‘except*’ estrae dal gruppo le eccezioni di un certo tipo
lasciando che tutte le altre eccezioni si propaghino ad altre clausole
e, infine, vengano rilanciate.

     >>> def f():
     ...     raise ExceptionGroup(
     ...         "group1",
     ...         [
     ...             OSError(1),
     ...             SystemError(2),
     ...             ExceptionGroup(
     ...                 "group2",
     ...                 [
     ...                     OSError(3),
     ...                     RecursionError(4)
     ...                 ]
     ...             )
     ...         ]
     ...     )
     ...
     >>> try:
     ...     f()
     ... except* OSError as e:
     ...     print("There were OSErrors")
     ... except* SystemError as e:
     ...     print("There were SystemErrors")
     ...
     There were OSErrors
     There were SystemErrors
       + Exception Group Traceback (most recent call last):
       |   File "<stdin>", line 2, in <module>
       |     f()
       |     ~^^
       |   File "<stdin>", line 2, in f
       |     raise ExceptionGroup(
       |     ...<12 lines>...
       |     )
       | ExceptionGroup: group1 (1 sub-exception)
       +-+---------------- 1 ----------------
         | ExceptionGroup: group2 (1 sub-exception)
         +-+---------------- 1 ----------------
           | RecursionError: 4
           +------------------------------------
     >>>

Nota che le eccezioni annidate in un gruppo di eccezioni devono essere
istanze, non tipi.  Questo perché in pratica le eccezioni sarebbero
tipicamente quelle che sono state già sollevate e catturate dal
programma, seguendo il seguente pattern:

     >>> excs = []
     ... for test in tests:
     ...     try:
     ...         test.run()
     ...     except Exception as e:
     ...         excs.append(e)
     ...
     >>> if excs:
     ...    raise ExceptionGroup("Test Failures", excs)
     ...


File: python.info,  Node: Arricchire le Eccezioni con Note,  Prev: Sollevare e Gestire Eccezioni Multiple e Non Correlate,  Up: Errori ed Eccezioni

2.8.10 Arricchire le Eccezioni con Note
---------------------------------------

Quando un’eccezione viene creata per essere sollevata, viene solitamente
inizializzata con informazioni che descrivono l’errore verificatosi.  Ci
sono casi in cui è utile aggiungere informazioni dopo che l’eccezione è
stata catturata.  Per questo scopo, le eccezioni hanno un metodo
‘add_note(note)’ che accetta una stringa e la aggiunge alla lista di
note dell’eccezione.  Il rendering standard del traceback include tutte
le note, nell’ordine in cui sono state aggiunte, dopo l’eccezione.

     >>> try:
     ...     raise TypeError('bad type')
     ... except Exception as e:
     ...     e.add_note('Add some information')
     ...     e.add_note('Add some more information')
     ...     raise
     ...
     Traceback (most recent call last):
       File "<stdin>", line 2, in <module>
         raise TypeError('bad type')
     TypeError: bad type
     Add some information
     Add some more information
     >>>

Per esempio, quando si raccolgono eccezioni in un gruppo di eccezioni,
potremmo voler aggiungere informazioni di contesto per gli errori
individuali.  Nel seguente esempio, ogni eccezione nel gruppo ha una
nota che indica quando si è verificato l’errore.

     >>> def f():
     ...     raise OSError('operation failed')
     ...
     >>> excs = []
     >>> for i in range(3):
     ...     try:
     ...         f()
     ...     except Exception as e:
     ...         e.add_note(f'Happened in Iteration {i+1}')
     ...         excs.append(e)
     ...
     >>> raise ExceptionGroup('We have some problems', excs)
       + Exception Group Traceback (most recent call last):
       |   File "<stdin>", line 1, in <module>
       |     raise ExceptionGroup('We have some problems', excs)
       | ExceptionGroup: We have some problems (3 sub-exceptions)
       +-+---------------- 1 ----------------
         | Traceback (most recent call last):
         |   File "<stdin>", line 3, in <module>
         |     f()
         |     ~^^
         |   File "<stdin>", line 2, in f
         |     raise OSError('operation failed')
         | OSError: operation failed
         | Happened in Iteration 1
         +---------------- 2 ----------------
         | Traceback (most recent call last):
         |   File "<stdin>", line 3, in <module>
         |     f()
         |     ~^^
         |   File "<stdin>", line 2, in f
         |     raise OSError('operation failed')
         | OSError: operation failed
         | Happened in Iteration 2
         +---------------- 3 ----------------
         | Traceback (most recent call last):
         |   File "<stdin>", line 3, in <module>
         |     f()
         |     ~^^
         |   File "<stdin>", line 2, in f
         |     raise OSError('operation failed')
         | OSError: operation failed
         | Happened in Iteration 3
         +------------------------------------
     >>>


File: python.info,  Node: Classi,  Next: Breve Panoramica della Libreria Standard,  Prev: Errori ed Eccezioni,  Up: Tutorial su Python

2.9 Classi
==========

Le classi forniscono un mezzo per raggruppare dati e funzionalità
insieme.  Creare una nuova classe crea un nuovo 'tipo' di oggetto,
consentendo la creazione di nuove 'istanze' di quel tipo.  Ogni istanza
di classe può avere attributi ad essa associati per mantenere il suo
stato.  Le istanze di classe possono anche avere metodi (definiti dalla
sua classe) per modificarne lo stato.

Rispetto ad altri linguaggi di programmazione, il meccanismo delle
classi di Python aggiunge classi con un minimo di nuova sintassi e
semantica.  È un misto dei meccanismi di classe trovati in C++ e
Modula-3.  Le classi Python forniscono tutte le funzionalità standard
della programmazione orientata agli oggetti: il meccanismo di
ereditarietà delle classi consente più classi di base, una classe
derivata può sovrascrivere qualsiasi metodo della sua classe base o
classi, e un metodo può chiamare il metodo di una classe di base con lo
stesso nome.  Gli oggetti possono contenere quantità e tipi di dati
arbitrari.  Come è vero per i moduli, le classi partecipano alla natura
dinamica di Python: sono create a tempo di esecuzione e possono essere
modificate ulteriormente dopo la creazione.

Nella terminologia di C++, normalmente i membri della classe (compresi i
membri dei dati) sono 'pubblici' (tranne vedere sotto *note Variabili
Private: 2073.), e tutte le funzioni membro sono 'virtuali'.  Come in
Modula-3, non ci sono abbreviazioni per fare riferimento ai membri
dell’oggetto dai suoi metodi: la funzione del metodo è dichiarata con un
primo argomento esplicito che rappresenta l’oggetto, che è fornito
implicitamente dalla chiamata.  Come in Smalltalk, le classi stesse sono
oggetti.  Questo fornisce la semantica per l’importazione e il
ridenominare.  A differenza di C++ e Modula-3, i tipi integrati possono
essere utilizzati come classi di base per l’estensione da parte
dell’utente.  Inoltre, come in C++, la maggior parte degli operatori
integrati con una sintassi speciale (operatori aritmetici,
indicizzazione ecc.)  possono essere ridefiniti per le istanze della
classe.

(Mancando una terminologia universalmente accettata per parlare di
classi, farò un uso occasionale dei termini Smalltalk e C++.
Utilizzerei i termini di Modula-3, poiché la sua semantica orientata
agli oggetti è più vicina a quella di Python rispetto a C++, ma mi
aspetto che pochi lettori ne abbiano sentito parlare.)

* Menu:

* Una parola su nomi e oggetti::
* Visibilità e spazi dei nomi in Python::
* Una prima occhiata alle classi::
* Osservazioni Varie::
* Ereditarietà::
* Variabili Private::
* Varie ed Eventuali::
* Iteratori::
* Generatori::
* Espressioni di Generatore::


File: python.info,  Node: Una parola su nomi e oggetti,  Next: Visibilità e spazi dei nomi in Python,  Up: Classi

2.9.1 Una parola su nomi e oggetti
----------------------------------

Gli oggetti hanno individualità e più nomi (in più ambiti) possono
essere vincolati allo stesso oggetto.  Questo è noto come aliasing in
altri linguaggi.  Questo di solito non è apprezzato a una prima occhiata
a Python e può essere tranquillamente ignorato quando si tratta di tipi
di base immutabili (numeri, stringhe, tuple).  Tuttavia, l’aliasing ha
un effetto possibilmente sorprendente sulla semantica del codice Python
che coinvolge oggetti mutabili come liste, dizionari e la maggior parte
degli altri tipi.  Questo è di solito usato a vantaggio del programma,
poiché gli alias si comportano come puntatori in alcuni aspetti.  Ad
esempio, passare un oggetto è economico poiché viene passato solo un
puntatore dall’implementazione; e se una funzione modifica un oggetto
passato come argomento, il chiamante vedrà il cambiamento — questo
elimina la necessità di due diversi meccanismi di passaggio degli
argomenti come in Pascal.


File: python.info,  Node: Visibilità e spazi dei nomi in Python,  Next: Una prima occhiata alle classi,  Prev: Una parola su nomi e oggetti,  Up: Classi

2.9.2 Visibilità e spazi dei nomi in Python
-------------------------------------------

Prima di introdurre le classi, devo prima dirti qualcosa sulle regole di
visibilità di Python.  Le definizioni di classe fanno alcuni trucchi
interessanti con gli spazi dei nomi e devi sapere come funzionano le
visibilità e gli spazi dei nomi per capire appieno cosa sta succedendo.
Per inciso, la conoscenza su questo argomento è utile per qualsiasi
programmatore Python avanzato.

Iniziamo con alcune definizioni.

Uno 'spazio dei nomi' è una mappatura da nomi a oggetti.  La maggior
parte degli spazi dei nomi è attualmente implementata come dizionari
Python, ma normalmente non è percepibile in alcun modo (tranne per le
prestazioni) e potrebbe cambiare in futuro.  Esempi di spazi dei nomi
sono: l’insieme di nomi integrati (contenente funzioni come *note abs():
2077. e nomi di eccezioni integrate); i nomi globali in un modulo; e i
nomi locali in una chiamata di funzione.  In un certo senso, l’insieme
di attributi di un oggetto forma anche uno spazio dei nomi.  La cosa
importante da sapere sugli spazi dei nomi è che non c’è assolutamente
alcuna relazione tra nomi in spazi dei nomi diversi; ad esempio, due
moduli diversi possono entrambi definire una funzione ‘massimizza’ senza
confusione — gli utenti dei moduli devono prefissarlo con il nome del
modulo.

A proposito, uso la parola 'attributo' per qualsiasi nome che segue un
punto — ad esempio, nell’espressione ‘z.reale’, ‘reale’ è un attributo
dell’oggetto ‘z’.  Più precisamente, i riferimenti ai nomi nei moduli
sono riferimenti agli attributi: nell’espressione
‘nomemodulo.nomefunzione’, ‘nomemodulo’ è un oggetto modulo e
‘nomefunzione’ è un suo attributo.  In questo caso c’è una
corrispondenza diretta tra gli attributi del modulo e i nomi globali
definiti nel modulo: condividono lo stesso spazio dei nomi!  (1)

Gli attributi possono essere di sola lettura o scrivibili.  In
quest’ultimo caso, l’assegnazione agli attributi è possibile.  Gli
attributi del modulo sono scrivibili: puoi scrivere
‘nomemodulo.larisposta = 42’.  Gli attributi scrivibili possono anche
essere eliminati con l’istruzione *note del: 1b07.  Ad esempio, ‘del
nomemodulo.larisposta’ rimuoverà l’attributo ‘larisposta’ dall’oggetto
denominato da ‘nomemodulo’.

Gli spazi dei nomi sono creati in momenti diversi e hanno durate
diverse.  Lo spazio dei nomi che contiene i nomi integrati è creato
quando l’interprete Python si avvia e non viene mai eliminato.  Lo
spazio dei nomi globale per un modulo è creato quando la definizione del
modulo viene letta; normalmente, gli spazi dei nomi dei moduli durano
anche fino a quando l’interprete non si arresta.  Le istruzioni eseguite
dall’invocazione di livello superiore dell’interprete, lette da un file
di script o interattivamente, sono considerate parte di un modulo
chiamato *note __main__: 1, quindi hanno il loro proprio spazio dei nomi
globale.  (I nomi integrati in realtà vivono anche in un modulo; questo
si chiama *note builtins: 13.)

Lo spazio dei nomi locale per una funzione è creato quando la funzione
viene chiamata e eliminato quando la funzione restituisce o genera
un’eccezione che non viene gestita all’interno della funzione.  (In
realtà, dimenticare sarebbe un modo migliore per descrivere ciò che
accade effettivamente.)  Naturalmente, le invocazioni ricorsive hanno
ciascuna il proprio spazio dei nomi locale.

Uno 'scope' è una regione testuale di un programma Python in cui uno
spazio dei nomi è direttamente accessibile.  «Direttamente accessibile»
qui significa che un riferimento non qualificato a un nome tenta di
trovare il nome nello spazio dei nomi.

Anche se gli scope sono determinati staticamente, vengono utilizzati
dinamicamente.  In qualsiasi momento durante l’esecuzione, ci sono 3 o 4
scope annidati i cui spazi dei nomi sono direttamente accessibili:

   * lo scope più interno, che viene cercato per primo, contiene i nomi
     locali

   * gli scope di eventuali funzioni contenenti, che vengono cercati a
     partire dallo scope contenente più vicino, contengono nomi non
     locali, ma anche non globali

   * il penultimo scope contiene i nomi globali del modulo corrente

   * lo scope più esterno (cercato per ultimo) è lo spazio dei nomi che
     contiene i nomi integrati

Se un nome è dichiarato globale, allora tutti i riferimenti e le
assegnazioni vanno direttamente allo scope penultimo contenente i nomi
globali del modulo.  Per rilegare le variabili trovate al di fuori dello
scope più interno, può essere utilizzata l’istruzione *note nonlocal:
14af.; se non dichiarate nonlocal, quelle variabili sono di sola lettura
(un tentativo di scrivere su una variabile del genere creerà
semplicemente una 'nuova' variabile locale nello scope più interno,
lasciando invariata la variabile esterna con lo stesso nome).

Di solito, lo scope locale fa riferimento ai nomi locali della funzione
(testualmente) corrente.  Al di fuori delle funzioni, lo scope locale fa
riferimento allo stesso spazio dei nomi dello scope globale: lo spazio
dei nomi del modulo.  Le definizioni di classe pongono un altro spazio
dei nomi nello scope locale.

È importante rendersi conto che gli scope sono determinati testualmente:
lo scope globale di una funzione definita in un modulo è lo spazio dei
nomi del modulo, non importa da dove o con quale alias la funzione viene
chiamata.  D’altra parte, la ricerca effettiva dei nomi viene fatta
dinamicamente, a tempo di esecuzione — tuttavia, la definizione del
linguaggio sta evolvendo verso la risoluzione statica dei nomi, a tempo
di «compilazione», quindi non fare affidamento sulla risoluzione
dinamica dei nomi!  (Infatti, le variabili locali sono già determinate
staticamente.)

Una particolarità speciale di Python è che – se non è in vigore alcuna
istruzione *note global: 4ad. o *note nonlocal: 14af. – le assegnazioni
ai nomi vanno sempre nello scope più interno.  Le assegnazioni non
copiano i dati — vincolano solo i nomi agli oggetti.  Lo stesso vale per
le eliminazioni: l’istruzione ‘del x’ rimuove il vincolo di ‘x’ dallo
spazio dei nomi riferito dallo scope locale.  In realtà, tutte le
operazioni che introducono nuovi nomi utilizzano lo scope locale: in
particolare, le istruzioni *note import: 7f9. e le definizioni di
funzioni vincolano il nome del modulo o della funzione nello scope
locale.

L’istruzione *note global: 4ad. può essere utilizzata per indicare che
particolari variabili vivono nello scope globale e dovrebbero essere
rilegate lì; l’istruzione *note nonlocal: 14af. indica che particolari
variabili vivono in uno scope circoscritto e dovrebbero essere rilegate
lì.

* Menu:

* Esempio di visibilità e spazi dei nomi::

   ---------- Footnotes ----------

   (1) Except for one thing.  Module objects have a secret read-only
attribute called *note __dict__: 77e. which returns the dictionary used
to implement the module’s namespace; the name ‘__dict__’ is an attribute
but not a global name.  Obviously, using this violates the abstraction
of namespace implementation, and should be restricted to things like
post-mortem debuggers.


File: python.info,  Node: Esempio di visibilità e spazi dei nomi,  Up: Visibilità e spazi dei nomi in Python

2.9.2.1 Esempio di visibilità e spazi dei nomi
..............................................

Questo è un esempio che dimostra come fare riferimento ai diversi scope
e spazi dei nomi e come *note global: 4ad. e *note nonlocal: 14af.
influenzano il vincolo delle variabili:

     def scope_test():
         def do_local():
             spam = "local spam"

         def do_nonlocal():
             nonlocal spam
             spam = "nonlocal spam"

         def do_global():
             global spam
             spam = "global spam"

         spam = "test spam"
         do_local()
         print("After local assignment:", spam)
         do_nonlocal()
         print("After nonlocal assignment:", spam)
         do_global()
         print("After global assignment:", spam)

     scope_test()
     print("In global scope:", spam)

L’output del codice di esempio è:

     After local assignment: test spam
     After nonlocal assignment: nonlocal spam
     After global assignment: nonlocal spam
     In global scope: global spam

Nota come l’assegnazione 'locale' (che è predefinita) non abbia cambiato
il vincolo di 'spam' di 'scope_test'.  L’assegnazione *note nonlocal:
14af. ha cambiato il vincolo di 'spam' di 'scope_test' e l’assegnazione
*note global: 4ad. ha cambiato il vincolo a livello di modulo.

Si può anche vedere che non c’era alcun vincolo precedente per 'spam'
prima dell’assegnazione *note global: 4ad.


File: python.info,  Node: Una prima occhiata alle classi,  Next: Osservazioni Varie,  Prev: Visibilità e spazi dei nomi in Python,  Up: Classi

2.9.3 Una prima occhiata alle classi
------------------------------------

Le classi introducono un po” di nuova sintassi, tre nuovi tipi di
oggetti e alcune nuove semantiche.

* Menu:

* Sintassi della definizione di classe::
* Oggetti della Classe::
* Oggetti Istanza::
* Oggetti Metodo::
* Variabili di Classe e Istanza::


File: python.info,  Node: Sintassi della definizione di classe,  Next: Oggetti della Classe,  Up: Una prima occhiata alle classi

2.9.3.1 Sintassi della definizione di classe
............................................

La forma più semplice di definizione di classe appare così:

     class ClassName:
         <statement-1>
         .
         .
         .
         <statement-N>

Le definizioni di classe, come le definizioni di funzione (istruzioni
*note def: 1661.), devono essere eseguite prima di avere effetto.
(Potresti concepibilmente collocare una definizione di classe in un ramo
di un’istruzione *note if: 181. o all’interno di una funzione.)

In pratica, le istruzioni all’interno di una definizione di classe
saranno solitamente definizioni di funzioni, ma sono ammesse e talvolta
utili — torneremo su questo più tardi.  Le definizioni di funzioni
all’interno di una classe hanno normalmente una forma peculiare di
elenco degli argomenti, dettata dalle convenzioni di chiamata per i
metodi — anche questo è spiegato più tardi.

Quando una definizione di classe viene inserita, viene creato un nuovo
spazio dei nomi e utilizzato come scope locale — quindi, tutte le
assegnazioni alle variabili locali vanno in questo nuovo spazio dei
nomi.  In particolare, qui le definizioni di funzioni vincolano il nome
della nuova funzione.

Quando una definizione di classe viene lasciata normalmente (tramite la
fine), viene creato un 'oggetto classe'.  Questo è essenzialmente un
wrapper attorno ai contenuti dello spazio dei nomi creato dalla
definizione di classe; impareremo di più sugli oggetti classe nella
sezione successiva.  Lo scope locale originale (quello in vigore appena
prima che la definizione di classe fosse inserita) viene ripristinato e
l’oggetto classe è vincolato qui al nome della classe dato
dall’intestazione della definizione di classe (‘NomeClasse’
nell’esempio).


File: python.info,  Node: Oggetti della Classe,  Next: Oggetti Istanza,  Prev: Sintassi della definizione di classe,  Up: Una prima occhiata alle classi

2.9.3.2 Oggetti della Classe
............................

Gli oggetti della classe supportano due tipi di operazioni: riferimenti
agli attributi e istanziazione.

I 'riferimenti agli attributi' utilizzano la sintassi standard
utilizzata per tutti i riferimenti agli attributi in Python:
‘oggetto.nome’.  I nomi degli attributi validi sono tutti i nomi che
erano nello spazio dei nomi della classe quando l’oggetto classe è stato
creato.  Quindi, se la definizione della classe apparisse così:

     class MyClass:
         """A simple example class"""
         i = 12345

         def f(self):
             return 'hello world'

then ‘MyClass.i’ and ‘MyClass.f’ are valid attribute references,
returning an integer and a function object, respectively.  Class
attributes can also be assigned to, so you can change the value of
‘MyClass.i’ by assignment.  *note __doc__: 207f. is also a valid
attribute, returning the docstring belonging to the class: ‘"A simple
example class"’.

L”'istanziamento' della classe utilizza la notazione funzionale.  Basta
immaginare che l’oggetto classe sia una funzione senza parametri che
restituisce una nuova istanza della classe.  Per esempio (assumendo la
classe sopra menzionata):

     x = MyClass()

crea una nuova 'istanza' della classe e assegna questo oggetto alla
variabile locale ‘x’.

L’operazione di istanziazione («chiamare» un oggetto classe) crea un
oggetto vuoto.  Molte classi preferiscono creare oggetti con istanze
personalizzate per uno stato iniziale specifico.  Pertanto, una classe
può definire un metodo speciale chiamato *note __init__(): 8c0, come
questo:

     def __init__(self):
         self.data = []

Quando una classe definisce un metodo *note __init__(): 8c0,
l’istanziamento della classe invoca automaticamente ‘__init__()’ per la
nuova istanza della classe creata.  Quindi, in questo esempio, una nuova
istanza inizializzata può essere ottenuta con:

     x = MyClass()

Ovviamente, il metodo *note __init__(): 8c0. può avere argomenti per una
maggiore flessibilità.  In tal caso, gli argomenti forniti all’operatore
di istanziazione della classe vengono passati a ‘__init__()’.  Per
esempio,

     >>> class Complex:
     ...     def __init__(self, realpart, imagpart):
     ...         self.r = realpart
     ...         self.i = imagpart
     ...
     >>> x = Complex(3.0, -4.5)
     >>> x.r, x.i
     (3.0, -4.5)


File: python.info,  Node: Oggetti Istanza,  Next: Oggetti Metodo,  Prev: Oggetti della Classe,  Up: Una prima occhiata alle classi

2.9.3.3 Oggetti Istanza
.......................

Ora, cosa possiamo fare con gli oggetti istanza?  Le uniche operazioni
comprese dagli oggetti istanza sono i riferimenti agli attributi.  Ci
sono due tipi di nomi di attributi validi: attributi dati e metodi.

'Data attributes' correspond to «instance variables» in Smalltalk, and
to «data members» in C++.  Data attributes need not be declared; like
local variables, they spring into existence when they are first assigned
to.  For example, if ‘x’ is the instance of ‘MyClass’ created above, the
following piece of code will print the value ‘16’, without leaving a
trace:

     x.counter = 1
     while x.counter < 10:
         x.counter = x.counter * 2
     print(x.counter)
     del x.counter

The other kind of instance attribute reference is a 'method'.  A method
is a function that «belongs to» an object.

I nomi dei metodi validi di un oggetto istanza dipendono dalla sua
classe.  Per definizione, tutti gli attributi di una classe che sono
oggetti funzione definiscono i metodi corrispondenti delle sue istanze.
Quindi nel nostro esempio, ‘x.f’ è un riferimento a un metodo valido,
poiché ‘MyClass.f’ è una funzione, ma ‘x.i’ no, poiché ‘MyClass.i’ non
lo è.  Tuttavia, ‘x.f’ non è la stessa cosa di ‘MyClass.f’ — è un
'oggetto metodo', non un oggetto funzione.


File: python.info,  Node: Oggetti Metodo,  Next: Variabili di Classe e Istanza,  Prev: Oggetti Istanza,  Up: Una prima occhiata alle classi

2.9.3.4 Oggetti Metodo
......................

Di solito, un metodo viene chiamato subito dopo essere stato associato:

     x.f()

If ‘x = MyClass()’, as above, this will return the string ‘'hello
world'’.  However, it is not necessary to call a method right away:
‘x.f’ is a method object, and can be stored away and called at a later
time.  For example:

     xf = x.f
     while True:
         print(xf())

continuerà a stampare ‘hello world’ fino alla fine dei tempi.

Cosa succede esattamente quando un metodo viene chiamato?  Potreste aver
notato che ‘x.f()’ è stato chiamato senza argomento sopra, anche se la
definizione della funzione per ‘f()’ specifica un argomento.  Che fine
ha fatto l’argomento?  Sicuramente Python solleva un’eccezione quando
una funzione che richiede un argomento viene chiamata senza alcuno —
anche se l’argomento non è effettivamente usato…

In realtà, potreste aver indovinato la risposta: la caratteristica
speciale dei metodi è che l’istanza dell’oggetto viene passata come
primo argomento della funzione.  Nel nostro esempio, la chiamata ‘x.f()’
è esattamente equivalente a ‘MyClass.f(x)’.  In generale, chiamare un
metodo con una lista di 'n' argomenti è equivalente a chiamare la
funzione corrispondente con una lista di argomenti creata inserendo
l’istanza del metodo prima del primo argomento.

In generale, i metodi funzionano come segue.  Quando viene referenziato
un attributo non dato di un’istanza, viene cercata la classe
dell’istanza.  Se il nome denota un attributo di classe valido che è un
oggetto funzione, i riferimenti all’istanza dell’oggetto e all’oggetto
funzione vengono impacchettati in un oggetto metodo.  Quando l’oggetto
metodo viene chiamato con una lista di argomenti, viene costruita una
nuova lista di argomenti dall’istanza dell’oggetto e la lista degli
argomenti, e l’oggetto funzione viene chiamato con questa nuova lista di
argomenti.


File: python.info,  Node: Variabili di Classe e Istanza,  Prev: Oggetti Metodo,  Up: Una prima occhiata alle classi

2.9.3.5 Variabili di Classe e Istanza
.....................................

Generalmente parlando, le variabili di istanza sono per i dati unici a
ciascuna istanza e le variabili di classe sono per gli attributi e i
metodi condivisi da tutte le istanze della classe:

     class Dog:

         kind = 'canine'         # class variable shared by all instances

         def __init__(self, name):
             self.name = name    # instance variable unique to each instance

     >>> d = Dog('Fido')
     >>> e = Dog('Buddy')
     >>> d.kind                  # shared by all dogs
     'canine'
     >>> e.kind                  # shared by all dogs
     'canine'
     >>> d.name                  # unique to d
     'Fido'
     >>> e.name                  # unique to e
     'Buddy'

Come discusso in *note Una parola su nomi e oggetti: 2075, i dati
condivisi possono avere effetti potenzialmente sorprendenti coinvolgendo
oggetti *note mutable: 1fcd. come liste e dizionari.  Per esempio, la
lista 'tricks' nel seguente codice non dovrebbe essere usata come
variabile di classe perché solo una singola lista verrebbe condivisa da
tutte le istanze di 'Dog':

     class Dog:

         tricks = []             # mistaken use of a class variable

         def __init__(self, name):
             self.name = name

         def add_trick(self, trick):
             self.tricks.append(trick)

     >>> d = Dog('Fido')
     >>> e = Dog('Buddy')
     >>> d.add_trick('roll over')
     >>> e.add_trick('play dead')
     >>> d.tricks                # unexpectedly shared by all dogs
     ['roll over', 'play dead']

Il design corretto della classe dovrebbe usare una variabile di istanza
invece:

     class Dog:

         def __init__(self, name):
             self.name = name
             self.tricks = []    # creates a new empty list for each dog

         def add_trick(self, trick):
             self.tricks.append(trick)

     >>> d = Dog('Fido')
     >>> e = Dog('Buddy')
     >>> d.add_trick('roll over')
     >>> e.add_trick('play dead')
     >>> d.tricks
     ['roll over']
     >>> e.tricks
     ['play dead']


File: python.info,  Node: Osservazioni Varie,  Next: Ereditarietà,  Prev: Una prima occhiata alle classi,  Up: Classi

2.9.4 Osservazioni Varie
------------------------

Se lo stesso nome di attributo appare sia in un’istanza che in una
classe, la ricerca degli attributi dà priorità all’istanza:

     >>> class Warehouse:
     ...    purpose = 'storage'
     ...    region = 'west'
     ...
     >>> w1 = Warehouse()
     >>> print(w1.purpose, w1.region)
     storage west
     >>> w2 = Warehouse()
     >>> w2.region = 'east'
     >>> print(w2.purpose, w2.region)
     storage east

Gli attributi dati possono essere referenziati dai metodi così come
dagli utenti ordinari («clienti») di un oggetto.  In altre parole, le
classi non sono utilizzabili per implementare tipi di dati astratti
puri.  Infatti, nulla in Python permette di imporre l’incapsulamento dei
dati — è tutto basato su convenzioni.  (D’altra parte, l’implementazione
di Python, scritta in C, può nascondere completamente i dettagli di
implementazione e controllare l’accesso a un oggetto se necessario;
questo può essere utilizzato dalle estensioni a Python scritte in C.)

I clienti dovrebbero usare gli attributi dati con cautela — i clienti
potrebbero infrangere gli invarianti mantenuti dai metodi alterando i
loro attributi dati.  Si noti che i clienti possono aggiungere attributi
dati propri a un oggetto istanza senza influenzare la validità dei
metodi, purché vengano evitati conflitti di nomi — ancora una volta, una
convenzione di nomenclatura può risparmiare molti mal di testa.

Non c’è alcuna scorciatoia per riferirsi agli attributi dati (o ad altri
metodi!)  dall’interno dei metodi.  Trovo che questo in realtà aumenti
la leggibilità dei metodi: non c’è possibilità di confondere variabili
locali e variabili di istanza quando si scorre un metodo.

Spesso, il primo argomento di un metodo è chiamato ‘self’.  Questa è
niente più che una convenzione: il nome ‘self’ non ha assolutamente
alcun significato speciale per Python.  Tieni presente, tuttavia, che
non seguire la convenzione potrebbe rendere il tuo codice meno leggibile
per altri programmatori Python, e non è nemmeno impossibile che venga
scritto un programma 'class browser' che si basa su tale convenzione.

Qualsiasi oggetto funzione che è un attributo di classe definisce un
metodo per le istanze di quella classe.  Non è necessario che la
definizione della funzione sia testualmente inclusa nella definizione
della classe: è anche possibile assegnare un oggetto funzione a una
variabile locale nella classe.  Per esempio:

     # Function defined outside the class
     def f1(self, x, y):
         return min(x, x+y)

     class C:
         f = f1

         def g(self):
             return 'hello world'

         h = g

Ora ‘f’, ‘g’ e ‘h’ sono tutti attributi della classe ‘C’ che si
riferiscono a oggetti funzione, e di conseguenza sono tutti metodi delle
istanze della classe ‘C’ — ‘h’ essendo esattamente equivalente a ‘g’.
Si noti che questa pratica di solito solo serve a confondere il lettore
di un programma.

I metodi possono chiamare altri metodi utilizzando gli attributi di
metodo dell’argomento ‘self’:

     class Bag:
         def __init__(self):
             self.data = []

         def add(self, x):
             self.data.append(x)

         def addtwice(self, x):
             self.add(x)
             self.add(x)

I metodi possono referenziare nomi globali allo stesso modo delle
funzioni ordinarie.  Lo scope globale associato a un metodo è il modulo
contenente la sua definizione.  (Una classe non è mai utilizzata come
uno scope globale.)  Sebbene raramente si incontri una buona ragione per
usare dati globali in un metodo, ci sono molti usi legittimi dello scope
globale: ad esempio, le funzioni e i moduli importati nello scope
globale possono essere utilizzati dai metodi, così come le funzioni e le
classi definite in esso.  Di solito, la classe contenente il metodo è
definita anch’essa in tale scope globale, e nella sezione successiva
troveremo alcune buone ragioni per cui un metodo potrebbe voler
referenziare la propria classe.

Ogni valore è un oggetto e quindi ha una 'classe' (chiamata anche il suo
'tipo').  È memorizzato come ‘object.__class__’.


File: python.info,  Node: Ereditarietà,  Next: Variabili Private,  Prev: Osservazioni Varie,  Up: Classi

2.9.5 Ereditarietà
------------------

Naturalmente, una caratteristica del linguaggio non sarebbe degna del
nome «classe» senza supportare l’ereditarietà.  La sintassi per la
definizione di una classe derivata è simile:

     class DerivedClassName(BaseClassName):
         <statement-1>
         .
         .
         .
         <statement-N>

Il nome ‘BaseClassName’ deve essere definito in uno spazio dei nomi
accessibile dallo scope contenente la definizione della classe derivata.
Al posto di un nome di classe base, sono permesse anche altre
espressioni arbitrarie.  Questo può essere utile, per esempio, quando la
classe base è definita in un altro modulo:

     class DerivedClassName(modname.BaseClassName):

L’esecuzione di una definizione di classe derivata procede nello stesso
modo di una classe base.  Quando viene costruito l’oggetto classe, viene
ricordata la classe base.  Questo viene utilizzato per risolvere i
riferimenti agli attributi: se un attributo richiesto non è trovato
nella classe, la ricerca procede a cercarlo nella classe base.  Questa
regola viene applicata ricorsivamente se la classe base stessa è
derivata da un’altra classe.

Non c’è nulla di speciale nell’istanza di classi derivate:
‘DerivedClassName()’ crea una nuova istanza della classe.  I riferimenti
ai metodi vengono risolti come segue: viene cercato l’attributo di
classe corrispondente, scendendo lungo la catena delle classi base se
necessario, e il riferimento al metodo è valido se questo produce un
oggetto funzione.

Le classi derivate possono ignorare i metodi delle loro classi base.
Poiché i metodi non hanno privilegi speciali quando chiamano altri
metodi dello stesso oggetto, un metodo di una classe base che chiama un
altro metodo definito nella stessa classe base può finire per chiamare
un metodo di una classe derivata che lo sostituisce.  (Per programmatori
C++: tutti i metodi in Python sono effettivamente ‘virtual’.)

Un metodo sovrascritto in una classe derivata può in realtà voler
estendere piuttosto che semplicemente sostituire il metodo della classe
base con lo stesso nome.  C’è un modo semplice per chiamare direttamente
il metodo della classe base: basta chiamare
‘BaseClassName.methodname(self, arguments)’.  Questo è occasionalmente
utile anche per i clienti.  (Si noti che questo funziona solo se la
classe base è accessibile come ‘BaseClassName’ nello scope globale.)

Python ha due funzioni built-in che funzionano con l’ereditarietà:

   * Usa *note isinstance(): 2ad. per controllare il tipo di un’istanza:
     ‘isinstance(obj, int)’ sarà ‘True’ solo se ‘obj.__class__’ è *note
     int: 19b. o una classe derivata da *note int: 19b.

   * Usa *note issubclass(): 9c6. per controllare l’ereditarietà delle
     classi: ‘issubclass(bool, int)’ è ‘True’ poiché *note bool: 3c3. è
     una sottoclasse di *note int: 19b.  Tuttavia, ‘issubclass(float,
     int)’ è ‘False’ poiché *note float: 196. non è una sottoclasse di
     *note int: 19b.

* Menu:

* Ereditarietà Multipla::


File: python.info,  Node: Ereditarietà Multipla,  Up: Ereditarietà

2.9.5.1 Ereditarietà Multipla
.............................

Python supporta anche una forma di ereditarietà multipla.  Una
definizione di classe con più classi base è simile:

     class DerivedClassName(Base1, Base2, Base3):
         <statement-1>
         .
         .
         .
         <statement-N>

Per la maggior parte degli scopi, nei casi più semplici, si può pensare
alla ricerca di attributi ereditati da una classe padre come alla
profondità prima, da sinistra a destra, senza cercare due volte nella
stessa classe dove c’è una sovrapposizione nella gerarchia.  Pertanto,
se un attributo non viene trovato in ‘DerivedClassName’, viene cercato
in ‘Base1’, quindi (ricorsivamente) nelle classi base di ‘Base1’, e se
non è stato trovato lì, viene cercato in ‘Base2’, e così via.

Infatti, è leggermente più complesso di così; l’ordine di risoluzione
del metodo cambia dinamicamente per supportare le chiamate cooperative a
*note super(): 1a6.  Questo approccio è noto in altri linguaggi con
ereditarietà multipla come call-next-method ed è più potente della
chiamata super trovata nei linguaggi a ereditarietà singola.

L’ordinamento dinamico è necessario perché tutti i casi di ereditarietà
multipla mostrano una o più relazioni di diamante (dove almeno una delle
classi padre può essere accessibile attraverso percorsi multipli dalla
classe più bassa).  Per esempio, tutte le classi ereditano da *note
object: c80, quindi qualsiasi caso di ereditarietà multipla fornisce più
di un percorso per raggiungere *note object: c80.  Per evitare che le
classi base vengano accessibili più di una volta, l’algoritmo dinamico
linearizza l’ordine di ricerca in modo che preserva l’ordunquezione da
sinistra a destra specificata in ogni classe, che chiama ogni genitore
solo una volta, e che è monotònico (significando che una classe può
essere sottoclasse senza influenzare l’ordine di precedenza dei suoi
genitori).  Insieme, queste proprietà rendono possibile progettare
classi affidabili ed estensibili con ereditarietà multipla.  Per
maggiori dettagli, vedi *note The Python 2.3 Method Resolution Order:
16b1.


File: python.info,  Node: Variabili Private,  Next: Varie ed Eventuali,  Prev: Ereditarietà,  Up: Classi

2.9.6 Variabili Private
-----------------------

Non esistono variabili di istanza «private» che non possono essere
accessibili se non all’interno di un oggetto in Python.  Tuttavia, c’è
una convenzione seguita dalla maggior parte del codice Python: un nome
prefisso con un trattino basso (es.  ‘_spam’) dovrebbe essere trattato
come una parte non pubblica dell’API (sia che sia una funzione, un
metodo o un membro dato).  Dovrebbe essere considerato un dettaglio di
implementazione e soggetto a cambiamento senza preavviso.

Poiché esiste un caso d’uso valido per i membri privati della classe
(ovvero per evitare conflitti di nomi con nomi definiti dalle
sottoclassi), c’è un supporto limitato per tale meccanismo, chiamato
'offuscamento dei nomi'.  Qualsiasi identificatore della forma ‘__spam’
(almeno due trattini bassi iniziali, al massimo uno finale) è
testualmente sostituito con ‘_classname__spam’, dove ‘classname’ è il
nome attuale della classe con i trattini bassi iniziali rimossi.  Questo
offuscamento viene eseguito senza riguardo alla posizione sintattica
dell’identificatore, purché si trovi all’interno della definizione di
una classe.

Vedi anche
..........

The *note private name mangling specifications: 208d. for details and
special cases.

L’offuscamento dei nomi è utile per permettere alle sottoclassi di
sovrascrivere i metodi senza rompere le chiamate ai metodi interni alla
classe.  Per esempio:

     class Mapping:
         def __init__(self, iterable):
             self.items_list = []
             self.__update(iterable)

         def update(self, iterable):
             for item in iterable:
                 self.items_list.append(item)

         __update = update   # private copy of original update() method

     class MappingSubclass(Mapping):

         def update(self, keys, values):
             # provides new signature for update()
             # but does not break __init__()
             for item in zip(keys, values):
                 self.items_list.append(item)

L’esempio sopra funzionerebbe anche se ‘MappingSubclass’ dovesse
introdurre un identificatore ‘__update’ poiché viene sostituito con
‘_Mapping__update’ nella classe ‘Mapping’ e ‘_MappingSubclass__update’
nella classe ‘MappingSubclass’ rispettivamente.

Si noti che le regole di offuscamento sono progettate soprattutto per
evitare incidenti; è ancora possibile accedere o modificare una
variabile considerata privata.  Questo può essere utile in circostanze
speciali, come nel debugger.

Si noti che il codice passato a ‘exec()’ o ‘eval()’ non considera la
classe nome dell’invocante per essere la classe attuale; questo è simile
all’effetto della dichiarazione ‘global’, l’effetto del quale è
analogamente limitato al codice che è compilato insieme.  La stessa
restrizione si applica a ‘getattr()’, ‘setattr()’ e ‘delattr()’, così
come quando si fa riferimento direttamente a ‘__dict__’.


File: python.info,  Node: Varie ed Eventuali,  Next: Iteratori,  Prev: Variabili Private,  Up: Classi

2.9.7 Varie ed Eventuali
------------------------

A volte è utile avere un tipo di dato simile al «record» del Pascal o al
«struct» del C, raggruppando insieme alcuni elementi dati con nome.
L’approccio idiomatico è utilizzare *note dataclasses: 33. per questo
scopo:

     from dataclasses import dataclass

     @dataclass
     class Employee:
         name: str
         dept: str
         salary: int

     >>> john = Employee('john', 'computer lab', 1000)
     >>> john.dept
     'computer lab'
     >>> john.salary
     1000

Un pezzo di codice Python che si aspetta un particolare tipo di dato
astratto può spesso essere passato a una classe che emula i metodi di
quel tipo di dato.  Per esempio, se hai una funzione che formatta alcuni
dati da un oggetto file, puoi definire una classe con i metodi *note
read(): 2056. e *note readline(): 2090. che ottengono i dati da un
buffer di stringhe, e passarla come argomento.

Gli *note oggetti metodo d’istanza: 2091. hanno anch’essi attributi:
*note m.__self__: 15d0. è l’oggetto istanza con il metodo ‘m()’, e *note
m.__func__: 1504. è l”*note oggetto funzione: 59c. corrispondente al
metodo.


File: python.info,  Node: Iteratori,  Next: Generatori,  Prev: Varie ed Eventuali,  Up: Classi

2.9.8 Iteratori
---------------

Ormai avrai probabilmente notato che la maggior parte degli oggetti
contenitori può essere iterata utilizzando un’istruzione *note for:
34a.:

     for element in [1, 2, 3]:
         print(element)
     for element in (1, 2, 3):
         print(element)
     for key in {'one':1, 'two':2}:
         print(key)
     for char in "123":
         print(char)
     for line in open("myfile.txt"):
         print(line, end='')

Questo stile di accesso è chiaro, conciso e conveniente.  L’uso degli
iteratori permea e unifica Python.  Dietro le quinte, l’istruzione *note
for: 34a. chiama la funzione *note iter(): 9d9. sull’oggetto
contenitore.  La funzione restituisce un oggetto iteratore che definisce
il metodo *note __next__(): 14d5. che accede agli elementi del
contenitore uno alla volta.  Quando non ci sono più elementi, *note
__next__(): 14d5. solleva un’eccezione *note StopIteration: df7. che
indica al ciclo ‘for’ di terminare.  Puoi chiamare il metodo *note
__next__(): 14d5. utilizzando la funzione built-in *note next(): 9da.;
questo esempio mostra come funziona tutto:

     >>> s = 'abc'
     >>> it = iter(s)
     >>> it
     <str_iterator object at 0x10c90e650>
     >>> next(it)
     'a'
     >>> next(it)
     'b'
     >>> next(it)
     'c'
     >>> next(it)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
         next(it)
     StopIteration

Avendo visto la meccanica dietro il protocollo dell’iteratore, è facile
aggiungere il comportamento di iteratore alle tue classi.  Definisci un
metodo *note __iter__(): 2094. che restituisce un oggetto con un metodo
*note __next__(): 14d5.  Se la classe definisce ‘__next__()’, allora
‘__iter__()’ può semplicemente restituire ‘self’:

     class Reverse:
         """Iterator for looping over a sequence backwards."""
         def __init__(self, data):
             self.data = data
             self.index = len(data)

         def __iter__(self):
             return self

         def __next__(self):
             if self.index == 0:
                 raise StopIteration
             self.index = self.index - 1
             return self.data[self.index]

     >>> rev = Reverse('spam')
     >>> iter(rev)
     <__main__.Reverse object at 0x00A1DB50>
     >>> for char in rev:
     ...     print(char)
     ...
     m
     a
     p
     s


File: python.info,  Node: Generatori,  Next: Espressioni di Generatore,  Prev: Iteratori,  Up: Classi

2.9.9 Generatori
----------------

I *note generatori: 1263. sono uno strumento semplice e potente per
creare iteratori.  Sono scritti come funzioni regolari ma utilizzano
l’istruzione *note yield: bc4. ogni volta che vogliono restituire dati.
Ogni volta che si chiama *note next(): 9da. su di esso, il generatore
riprende da dove si era interrotto (ricorda tutti i valori dei dati e
quale istruzione è stata eseguita per ultima).  Un esempio mostra che i
generatori possono essere creati con estrema facilità:

     def reverse(data):
         for index in range(len(data)-1, -1, -1):
             yield data[index]

     >>> for char in reverse('golf'):
     ...     print(char)
     ...
     f
     l
     o
     g

Tutto ciò che può essere fatto con i generatori può essere fatto anche
con gli iteratori basati su classi come descritto nella sezione
precedente.  Ciò che rende i generatori così compatti è che i metodi
*note __iter__(): 2097. e *note __next__(): 2098. sono creati
automaticamente.

Un’altra caratteristica chiave è che le variabili locali e lo stato di
esecuzione sono salvati automaticamente tra le chiamate.  Questo rende
la funzione più facile da scrivere e molto più chiara rispetto a un
approccio che utilizza variabili di istanza come ‘self.index’ e
‘self.data’.

Oltre alla creazione automatica dei metodi e al salvataggio dello stato
del programma, quando i generatori terminano, sollevano automaticamente
*note StopIteration: df7.  In combinazione, queste caratteristiche
rendono facile creare iteratori con lo stesso sforzo di scrivere una
funzione regolare.


File: python.info,  Node: Espressioni di Generatore,  Prev: Generatori,  Up: Classi

2.9.10 Espressioni di Generatore
--------------------------------

Alcuni generatori semplici possono essere codificati in modo conciso
come espressioni utilizzando una sintassi simile alle comprensioni di
lista ma con parentesi tonde anziché quadre.  Queste espressioni sono
progettate per situazioni in cui il generatore viene utilizzato
immediatamente da una funzione racchiudente.  Le espressioni di
generatore sono più compatte ma meno versatili rispetto alle definizioni
complete di generatore e tendono a essere più efficienti in termini di
memoria rispetto alle comprensioni di lista equivalenti.

Esempi:

     >>> sum(i*i for i in range(10))                 # sum of squares
     285

     >>> xvec = [10, 20, 30]
     >>> yvec = [7, 5, 3]
     >>> sum(x*y for x,y in zip(xvec, yvec))         # dot product
     260

     >>> unique_words = set(word for line in page  for word in line.split())

     >>> valedictorian = max((student.gpa, student.name) for student in graduates)

     >>> data = 'golf'
     >>> list(data[i] for i in range(len(data)-1, -1, -1))
     ['f', 'l', 'o', 'g']


File: python.info,  Node: Breve Panoramica della Libreria Standard,  Next: Giro Breve della Libreria Standard — Parte II,  Prev: Classi,  Up: Tutorial su Python

2.10 Breve Panoramica della Libreria Standard
=============================================

* Menu:

* Interfaccia del Sistema Operativo::
* Metacaratteri nei Nomfile::
* Argomenti dalla Linea di Comando::
* Reindirizzamento dell’Uscita degli Errori e Terminazione del Programma::
* Pattern Matching di Stringhe::
* Matematica::
* Accesso a Internet::
* Date e Orari::
* Compressione dei Dati::
* Misurazione delle Prestazioni::
* Controllo della Qualità::
* Batterie Incluse::


File: python.info,  Node: Interfaccia del Sistema Operativo,  Next: Metacaratteri nei Nomfile,  Up: Breve Panoramica della Libreria Standard

2.10.1 Interfaccia del Sistema Operativo
----------------------------------------

Il modulo *note os: a5. fornisce dozzine di funzioni per interagire con
il sistema operativo:

     >>> import os
     >>> os.getcwd()      # Return the current working directory
     'C:\\Python314'
     >>> os.chdir('/server/accesslogs')   # Change current working directory
     >>> os.system('mkdir today')   # Run the command mkdir in the system shell
     0

Assicurati di usare lo stile ‘import os’ invece di ‘from os import *’.
Questo eviterà che *note os.open(): f94. sovrasti la funzione built-in
*note open(): 316. che opera in modo molto diverso.

Le funzioni built-in *note dir(): 845. e *note help(): ad6. sono utili
come aiuti interattivi per lavorare con moduli grandi come *note os:
a5.:

     >>> import os
     >>> dir(os)
     <returns a list of all module functions>
     >>> help(os)
     <returns an extensive manual page created from the module's docstrings>

Per attività quotidiane di gestione di file e directory, il modulo *note
shutil: ca. fornisce un’interfaccia di livello superiore che è più
facile da usare:

     >>> import shutil
     >>> shutil.copyfile('data.db', 'archive.db')
     'archive.db'
     >>> shutil.move('/build/executables', 'installdir')
     'installdir'


File: python.info,  Node: Metacaratteri nei Nomfile,  Next: Argomenti dalla Linea di Comando,  Prev: Interfaccia del Sistema Operativo,  Up: Breve Panoramica della Libreria Standard

2.10.2 Metacaratteri nei Nomfile
--------------------------------

Il modulo *note glob: 68. fornisce una funzione per creare liste di file
a partire da ricerche con metacaratteri nei nomi delle directory:

     >>> import glob
     >>> glob.glob('*.py')
     ['primes.py', 'random.py', 'quote.py']


File: python.info,  Node: Argomenti dalla Linea di Comando,  Next: Reindirizzamento dell’Uscita degli Errori e Terminazione del Programma,  Prev: Metacaratteri nei Nomfile,  Up: Breve Panoramica della Libreria Standard

2.10.3 Argomenti dalla Linea di Comando
---------------------------------------

Gli script di utilità comuni spesso necessitano di elaborare gli
argomenti dalla linea di comando.  Questi argomenti sono memorizzati
nell’attributo 'argv' del modulo *note sys: df. come una lista.  Per
esempio, prendiamo il seguente file ‘demo.py’:

     # File demo.py
     import sys
     print(sys.argv)

Qui c’è l’output eseguendo ‘python demo.py one two three’ dalla linea di
comando:

     ['demo.py', 'one', 'two', 'three']

Il modulo *note argparse: 7. fornisce un meccanismo più sofisticato per
elaborare gli argomenti dalla linea di comando.  Il seguente script
estrae uno o più nomi di file e un numero opzionale di righe da
visualizzare:

     import argparse

     parser = argparse.ArgumentParser(
         prog='top',
         description='Show top lines from each file')
     parser.add_argument('filenames', nargs='+')
     parser.add_argument('-l', '--lines', type=int, default=10)
     args = parser.parse_args()
     print(args)

Quando eseguito dalla linea di comando con ‘python top.py --lines=5
alpha.txt beta.txt’, lo script assegna ‘args.lines’ a ‘5’ e
‘args.filenames’ a ‘['alpha.txt', 'beta.txt']’.


File: python.info,  Node: Reindirizzamento dell’Uscita degli Errori e Terminazione del Programma,  Next: Pattern Matching di Stringhe,  Prev: Argomenti dalla Linea di Comando,  Up: Breve Panoramica della Libreria Standard

2.10.4 Reindirizzamento dell’Uscita degli Errori e Terminazione del Programma
-----------------------------------------------------------------------------

Il modulo *note sys: df. ha anche attributi per 'stdin', 'stdout' e
'stderr'.  Quest’ultimo è utile per emettere avvisi e messaggi di errore
per renderli visibili anche quando 'stdout' è stato reindirizzato:

     >>> sys.stderr.write('Warning, log file not found starting a new one\n')
     Warning, log file not found starting a new one

Il modo più diretto per terminare uno script è usare ‘sys.exit()’.


File: python.info,  Node: Pattern Matching di Stringhe,  Next: Matematica,  Prev: Reindirizzamento dell’Uscita degli Errori e Terminazione del Programma,  Up: Breve Panoramica della Libreria Standard

2.10.5 Pattern Matching di Stringhe
-----------------------------------

Il modulo *note re: be. fornisce strumenti per le espressioni regolari
per l’elaborazione avanzata delle stringhe.  Per il matching e la
manipolazione complessi, le espressioni regolari offrono soluzioni
concise e ottimizzate:

     >>> import re
     >>> re.findall(r'\bf[a-z]*', 'which foot or hand fell fastest')
     ['foot', 'fell', 'fastest']
     >>> re.sub(r'(\b[a-z]+) \1', r'\1', 'cat in the the hat')
     'cat in the hat'

Quando sono necessarie solo semplici capacità, i metodi delle stringhe
sono preferiti perché sono più facili da leggere e fare debug:

     >>> 'tea for too'.replace('too', 'two')
     'tea for two'


File: python.info,  Node: Matematica,  Next: Accesso a Internet,  Prev: Pattern Matching di Stringhe,  Up: Breve Panoramica della Libreria Standard

2.10.6 Matematica
-----------------

The *note math: 92. module gives access to the underlying C library
functions for floating-point math:

     >>> import math
     >>> math.cos(math.pi / 4)
     0.70710678118654757
     >>> math.log(1024, 2)
     10.0

Il modulo *note random: bd. fornisce strumenti per effettuare selezioni
casuali:

     >>> import random
     >>> random.choice(['apple', 'pear', 'banana'])
     'apple'
     >>> random.sample(range(100), 10)   # sampling without replacement
     [30, 83, 16, 4, 8, 81, 41, 50, 18, 33]
     >>> random.random()    # random float from the interval [0.0, 1.0)
     0.17970987693706186
     >>> random.randrange(6)    # random integer chosen from range(6)
     4

Il modulo *note statistics: d7. calcola proprietà statistiche di base
(la media, la mediana, la varianza, ecc.)  di dati numerici:

     >>> import statistics
     >>> data = [2.75, 1.75, 1.25, 0.25, 0.5, 1.25, 3.5]
     >>> statistics.mean(data)
     1.6071428571428572
     >>> statistics.median(data)
     1.25
     >>> statistics.variance(data)
     1.3720238095238095

Il progetto SciPy <‘https://scipy.org’> ha molti altri moduli per i
calcoli numerici.


File: python.info,  Node: Accesso a Internet,  Next: Date e Orari,  Prev: Matematica,  Up: Breve Panoramica della Libreria Standard

2.10.7 Accesso a Internet
-------------------------

Ci sono molti moduli per accedere a internet e processare i protocolli
internet.  Due dei più semplici sono *note urllib.request: 111. per
recuperare dati da URL e *note smtplib: cf. per inviare mail:

     >>> from urllib.request import urlopen
     >>> with urlopen('https://docs.python.org/3/') as response:
     ...     for line in response:
     ...         line = line.decode()             # Convert bytes to a str
     ...         if 'updated' in line:
     ...             print(line.rstrip())         # Remove trailing newline
     ...
           Last updated on Nov 11, 2025 (20:11 UTC).

     >>> import smtplib
     >>> server = smtplib.SMTP('localhost')
     >>> server.sendmail('soothsayer@example.org', 'jcaesar@example.org',
     ... """To: jcaesar@example.org
     ... From: soothsayer@example.org
     ...
     ... Beware the Ides of March.
     ... """)
     >>> server.quit()

(Nota che il secondo esempio ha bisogno di un mailserver in esecuzione
su localhost.)


File: python.info,  Node: Date e Orari,  Next: Compressione dei Dati,  Prev: Accesso a Internet,  Up: Breve Panoramica della Libreria Standard

2.10.8 Date e Orari
-------------------

Il modulo *note datetime: 34. fornisce classi per manipolare date e
orari in modi sia semplici che complessi.  Mentre l’aritmetica su date e
orari è supportata, l’obiettivo dell’implementazione è l’estrazione
efficiente dei membri per la formattazione e la manipolazione
dell’output.  Il modulo supporta anche oggetti che sono consapevoli del
fuso orario.

     >>> # dates are easily constructed and formatted
     >>> from datetime import date
     >>> now = date.today()
     >>> now
     datetime.date(2003, 12, 2)
     >>> now.strftime("%m-%d-%y. %d %b %Y is a %A on the %d day of %B.")
     '12-02-03. 02 Dec 2003 is a Tuesday on the 02 day of December.'

     >>> # dates support calendar arithmetic
     >>> birthday = date(1964, 7, 31)
     >>> age = now - birthday
     >>> age.days
     14368


File: python.info,  Node: Compressione dei Dati,  Next: Misurazione delle Prestazioni,  Prev: Date e Orari,  Up: Breve Panoramica della Libreria Standard

2.10.9 Compressione dei Dati
----------------------------

I formati comuni di archiviazione e compressione dei dati sono
direttamente supportati dai moduli inclusi: *note zlib: 139, *note gzip:
6b, *note bz2: 14, *note lzma: 8e, *note zipfile: 137. e *note tarfile:
e4.

     >>> import zlib
     >>> s = b'witch which has which witches wrist watch'
     >>> len(s)
     41
     >>> t = zlib.compress(s)
     >>> len(t)
     37
     >>> zlib.decompress(t)
     b'witch which has which witches wrist watch'
     >>> zlib.crc32(s)
     226805979


File: python.info,  Node: Misurazione delle Prestazioni,  Next: Controllo della Qualità,  Prev: Compressione dei Dati,  Up: Breve Panoramica della Libreria Standard

2.10.10 Misurazione delle Prestazioni
-------------------------------------

Alcuni utenti di Python sviluppano un profondo interesse nel conoscere
le prestazioni relative di diversi approcci allo stesso problema.
Python fornisce uno strumento di misurazione che risponde a queste
domande immediatamente.

Per esempio, può essere allettante usare la funzione di impacchettamento
e spacchettamento delle tuple invece dell’approccio tradizionale per
scambiare argomenti.  Il modulo *note timeit: f5. dimostra rapidamente
un modesto vantaggio in termini di prestazioni:

     >>> from timeit import Timer
     >>> Timer('t=a; a=b; b=t', 'a=1; b=2').timeit()
     0.57535828626024577
     >>> Timer('a,b = b,a', 'a=1; b=2').timeit()
     0.54962537085770791

In contrasto con la fine granularità di *note timeit: f5, i moduli *note
profile: b4. e *note pstats: b5. forniscono strumenti per identificare
le sezioni critiche in termini di tempo in blocchi di codice più grandi.


File: python.info,  Node: Controllo della Qualità,  Next: Batterie Incluse,  Prev: Misurazione delle Prestazioni,  Up: Breve Panoramica della Libreria Standard

2.10.11 Controllo della Qualità
-------------------------------

Un approccio per sviluppare software di alta qualità è scrivere test per
ogni funzione mentre viene sviluppata e eseguire quei test
frequentemente durante il processo di sviluppo.

Il modulo *note doctest: 3e. fornisce uno strumento per scansionare un
modulo e validare i test incorporati nei docstring di un programma.  La
costruzione dei test è semplice come tagliare e incollare una tipica
chiamata con i suoi risultati nel docstring.  Questo migliora la
documentazione fornendo all’utente un esempio e permette al modulo
doctest di assicurarsi che il codice rimanga conforme alla
documentazione:

     def average(values):
         """Computes the arithmetic mean of a list of numbers.

         >>> print(average([20, 30, 70]))
         40.0
         """
         return sum(values) / len(values)

     import doctest
     doctest.testmod()   # automatically validate the embedded tests

Il modulo *note unittest: 10c. non è così semplice come il modulo *note
doctest: 3e, ma permette di mantenere un insieme più completo di test in
un file separato:

     import unittest

     class TestStatisticalFunctions(unittest.TestCase):

         def test_average(self):
             self.assertEqual(average([20, 30, 70]), 40.0)
             self.assertEqual(round(average([1, 5, 7]), 1), 4.3)
             with self.assertRaises(ZeroDivisionError):
                 average([])
             with self.assertRaises(TypeError):
                 average(20, 30, 70)

     unittest.main()  # Calling from the command line invokes all tests


File: python.info,  Node: Batterie Incluse,  Prev: Controllo della Qualità,  Up: Breve Panoramica della Libreria Standard

2.10.12 Batterie Incluse
------------------------

Python ha una filosofia di «batterie incluse».  Questo è reso evidente
dalle capacità sofisticate e robuste dei suoi pacchetti più grandi.  Per
esempio:

   * I moduli *note xmlrpc.client: 134. e *note xmlrpc.server: 135.
     rendono l’implementazione delle chiamate di procedure remote un
     compito quasi banale.  Nonostante i nomi dei moduli, non è
     necessaria una conoscenza o una gestione diretta dell’XML.

   * The *note email: 3f. package is a library for managing email
     messages, including MIME and other RFC 5322(1)-based message
     documents.  Unlike *note smtplib: cf. and *note poplib: b1. which
     actually send and receive messages, the email package has a
     complete toolset for building or decoding complex message
     structures (including attachments) and for implementing internet
     encoding and header protocols.

   * Il pacchetto *note json: 86. fornisce un supporto robusto per il
     parsing di questo popolare formato di interscambio dati.  Il modulo
     *note csv: 2d. supporta la lettura e la scrittura diretta di file
     nel formato Comma-Separated Value, comunemente supportato da
     database e fogli di calcolo.  L’elaborazione XML è supportata dai
     pacchetti *note xml.etree.ElementTree: 12b, *note xml.dom: 127. e
     *note xml.sax: 12f.  Insieme, questi moduli e pacchetti
     semplificano notevolmente l’interscambio di dati tra applicazioni
     Python e altri strumenti.

   * Il modulo *note sqlite3: d4. è un wrapper per la libreria del
     database SQLite, fornendo un database persistente che può essere
     aggiornato e accessibile utilizzando una sintassi SQL leggermente
     non standard.

   * L’internazionalizzazione è supportata da numerosi moduli tra cui
     *note gettext: 67, *note locale: 8a. e il pacchetto *note codecs:
     1c.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc5322.html


File: python.info,  Node: Giro Breve della Libreria Standard — Parte II,  Next: Ambienti Virtuali e Pacchetti,  Prev: Breve Panoramica della Libreria Standard,  Up: Tutorial su Python

2.11 Giro Breve della Libreria Standard — Parte II
==================================================

Questo secondo giro copre moduli più avanzati che supportano esigenze di
programmazione professionali.  Questi moduli raramente si trovano in
piccoli script.

* Menu:

* Formattazione dell’Output::
* Templating::
* Lavorare con Layout Binari dei Dati::
* Multi-threading: Multi-threading<2>.
* Logging::
* Riferimenti Deboli::
* Strumenti per Lavorare con Liste::
* Decimal Floating-Point Arithmetic::


File: python.info,  Node: Formattazione dell’Output,  Next: Templating,  Up: Giro Breve della Libreria Standard — Parte II

2.11.1 Formattazione dell’Output
--------------------------------

Il modulo *note reprlib: c0. fornisce una versione di *note repr(): 1c1.
personalizzata per visualizzazioni abbreviate di contenitori grandi o
profondamente annidati:

     >>> import reprlib
     >>> reprlib.repr(set('supercalifragilisticexpialidocious'))
     "{'a', 'c', 'd', 'e', 'f', 'g', ...}"

Il modulo *note pprint: b3. offre un controllo più sofisticato sulla
stampa di oggetti sia integrati che definiti dall’utente in modo
leggibile dall’interprete.  Quando il risultato è più lungo di una riga,
il «pretty printer» aggiunge interruzioni di riga e indentazione per
rivelare più chiaramente la struttura dei dati:

     >>> import pprint
     >>> t = [[[['black', 'cyan'], 'white', ['green', 'red']], [['magenta',
     ...     'yellow'], 'blue']]]
     ...
     >>> pprint.pprint(t, width=30)
     [[[['black', 'cyan'],
        'white',
        ['green', 'red']],
       [['magenta', 'yellow'],
        'blue']]]

Il modulo *note textwrap: f2. formatta paragrafi di testo per adattarsi
a una larghezza di schermo specificata:

     >>> import textwrap
     >>> doc = """The wrap() method is just like fill() except that it returns
     ... a list of strings instead of one big string with newlines to separate
     ... the wrapped lines."""
     ...
     >>> print(textwrap.fill(doc, width=40))
     The wrap() method is just like fill()
     except that it returns a list of strings
     instead of one big string with newlines
     to separate the wrapped lines.

Il modulo *note locale: 8a. accede a un database di formati di dati
specifici della cultura.  L’attributo di raggruppamento della funzione
di formattazione del locale fornisce un modo diretto di formattare i
numeri con separatori di gruppo:

     >>> import locale
     >>> locale.setlocale(locale.LC_ALL, 'English_United States.1252')
     'English_United States.1252'
     >>> conv = locale.localeconv()          # get a mapping of conventions
     >>> x = 1234567.8
     >>> locale.format_string("%d", x, grouping=True)
     '1,234,567'
     >>> locale.format_string("%s%.*f", (conv['currency_symbol'],
     ...                      conv['frac_digits'], x), grouping=True)
     '$1,234,567.80'


File: python.info,  Node: Templating,  Next: Lavorare con Layout Binari dei Dati,  Prev: Formattazione dell’Output,  Up: Giro Breve della Libreria Standard — Parte II

2.11.2 Templating
-----------------

Il modulo *note string: d8. include una versatile classe *note Template:
898. con una sintassi semplificata adatta per l’editing da parte degli
utenti finali.  Questo permette agli utenti di personalizzare le loro
applicazioni senza dover alterare l’applicazione.

Il formato utilizza nomi di segnaposto formati da ‘$’ con identificatori
Python validi (caratteri alfanumerici e trattini bassi).  Circondando il
segnaposto con parentesi graffe, è possibile farlo seguire da altre
lettere alfanumeriche senza spazi intermedi.  Scrivere ‘$$’ crea un
singolo ‘$’ escapato:

     >>> from string import Template
     >>> t = Template('${village}folk send $$10 to $cause.')
     >>> t.substitute(village='Nottingham', cause='the ditch fund')
     'Nottinghamfolk send $10 to the ditch fund.'

Il metodo *note substitute(): 20bf. solleva un’eccezione *note KeyError:
5e7. quando un segnaposto non è fornito in un dizionario o come
parametro keyword.  Per applicazioni stile mail-merge, i dati forniti
dall’utente possono essere incompleti e il metodo *note
safe_substitute(): 20c0. potrebbe essere più appropriato — lascerà i
segnaposto invariati se i dati sono mancanti:

     >>> t = Template('Return the $item to $owner.')
     >>> d = dict(item='unladen swallow')
     >>> t.substitute(d)
     Traceback (most recent call last):
       ...
     KeyError: 'owner'
     >>> t.safe_substitute(d)
     'Return the unladen swallow to $owner.'

Le sottoclassi di Template possono specificare un delimitatore
personalizzato.  Ad esempio, un’utilità per il rinominamento dei batch
di un browser di foto può scegliere di usare segni percentuali per i
segnaposto come la data corrente, il numero di sequenza delle immagini o
il formato del file:

     >>> import time, os.path
     >>> photofiles = ['img_1074.jpg', 'img_1076.jpg', 'img_1077.jpg']
     >>> class BatchRename(Template):
     ...     delimiter = '%'
     ...
     >>> fmt = input('Enter rename style (%d-date %n-seqnum %f-format):  ')
     Enter rename style (%d-date %n-seqnum %f-format):  Ashley_%n%f

     >>> t = BatchRename(fmt)
     >>> date = time.strftime('%d%b%y')
     >>> for i, filename in enumerate(photofiles):
     ...     base, ext = os.path.splitext(filename)
     ...     newname = t.substitute(d=date, n=i, f=ext)
     ...     print('{0} --> {1}'.format(filename, newname))

     img_1074.jpg --> Ashley_0.jpg
     img_1076.jpg --> Ashley_1.jpg
     img_1077.jpg --> Ashley_2.jpg

Un’altra applicazione per il templating è separare la logica del
programma dai dettagli di più formati di output.  Questo rende possibile
sostituire template personalizzati per file XML, rapporti in testo
semplice e rapporti HTML web.


File: python.info,  Node: Lavorare con Layout Binari dei Dati,  Next: Multi-threading<2>,  Prev: Templating,  Up: Giro Breve della Libreria Standard — Parte II

2.11.3 Lavorare con Layout Binari dei Dati
------------------------------------------

Il modulo *note struct: db. fornisce le funzioni *note pack(): 147e. e
*note unpack(): 1842. per lavorare con formati di record binari a
lunghezza variabile.  Il seguente esempio mostra come scorrere le
informazioni dell’intestazione in un file ZIP senza usare il modulo
*note zipfile: 137.  I codici pack ‘"H"’ e ‘"I"’ rappresentano numeri
senza segno a due e quattro byte rispettivamente.  Il ‘"<"’ indica che
hanno dimensioni standard e sono in byte order little-endian:

     import struct

     with open('myfile.zip', 'rb') as f:
         data = f.read()

     start = 0
     for i in range(3):                      # show the first 3 file headers
         start += 14
         fields = struct.unpack('<IIIHH', data[start:start+16])
         crc32, comp_size, uncomp_size, filenamesize, extra_size = fields

         start += 16
         filename = data[start:start+filenamesize]
         start += filenamesize
         extra = data[start:start+extra_size]
         print(filename, hex(crc32), comp_size, uncomp_size)

         start += extra_size + comp_size     # skip to the next header


File: python.info,  Node: Multi-threading<2>,  Next: Logging,  Prev: Lavorare con Layout Binari dei Dati,  Up: Giro Breve della Libreria Standard — Parte II

2.11.4 Multi-threading
----------------------

Il threading è una tecnica per disaccoppiare i compiti che non sono
sequenzialmente dipendenti.  I thread possono essere utilizzati per
migliorare la reattività delle applicazioni che accettano l’input
dell’utente mentre altri compiti vengono eseguiti in background.  Un
caso d’uso correlato è eseguire I/O in parallelo con calcoli in un altro
thread.

Il seguente codice mostra come il modulo ad alto livello *note
threading: f3. può eseguire compiti in background mentre il programma
principale continua a funzionare:

     import threading, zipfile

     class AsyncZip(threading.Thread):
         def __init__(self, infile, outfile):
             threading.Thread.__init__(self)
             self.infile = infile
             self.outfile = outfile

         def run(self):
             f = zipfile.ZipFile(self.outfile, 'w', zipfile.ZIP_DEFLATED)
             f.write(self.infile)
             f.close()
             print('Finished background zip of:', self.infile)

     background = AsyncZip('mydata.txt', 'myarchive.zip')
     background.start()
     print('The main program continues to run in foreground.')

     background.join()    # Wait for the background task to finish
     print('Main program waited until background was done.')

La principale sfida delle applicazioni multi-threaded è coordinare i
thread che condividono dati o altre risorse.  A tal fine, il modulo
threading fornisce numerosi primitivi di sincronizzazione tra cui lock,
eventi, variabili di condizione e semafori.

Sebbene questi strumenti siano potenti, piccoli errori di progettazione
possono provocare problemi difficili da riprodurre.  Quindi, l’approccio
preferito per il coordinamento dei compiti è concentrare tutto l’accesso
a una risorsa in un singolo thread e poi usare il modulo *note queue:
bb. per alimentare quel thread con richieste provenienti da altri
thread.  Le applicazioni che usano oggetti *note Queue: 159c. per la
comunicazione e il coordinamento tra thread sono più facili da
progettare, più leggibili e più affidabili.


File: python.info,  Node: Logging,  Next: Riferimenti Deboli,  Prev: Multi-threading<2>,  Up: Giro Breve della Libreria Standard — Parte II

2.11.5 Logging
--------------

Il modulo *note logging: 8b. offre un sistema di logging completo e
flessibile.  Nel suo uso più semplice, i messaggi di log vengono inviati
a un file o a ‘sys.stderr’:

     import logging
     logging.debug('Debugging information')
     logging.info('Informational message')
     logging.warning('Warning:config file %s not found', 'server.conf')
     logging.error('Error occurred')
     logging.critical('Critical error -- shutting down')

Questo produce il seguente output:

     WARNING:root:Warning:config file server.conf not found
     ERROR:root:Error occurred
     CRITICAL:root:Critical error -- shutting down

Per impostazione predefinita, i messaggi informativi e di debug sono
soppressi e l’output è inviato all’errore standard.  Altre opzioni di
output includono l’instradamento dei messaggi tramite email, datagrammi,
socket o a un server HTTP. Filtri nuovi possono selezionare
l’instradamento diverso basato sulla priorità del messaggio: *note
DEBUG: 20c7, *note INFO: 20c8, *note WARNING: 20c9, *note ERROR: 20ca, e
*note CRITICAL: 20cb.

Il sistema di logging può essere configurato direttamente da Python o
può essere caricato da un file di configurazione modificabile
dall’utente per un logging personalizzato senza alterare l’applicazione.


File: python.info,  Node: Riferimenti Deboli,  Next: Strumenti per Lavorare con Liste,  Prev: Logging,  Up: Giro Breve della Libreria Standard — Parte II

2.11.6 Riferimenti Deboli
-------------------------

Python gestisce automaticamente la memoria (conteggio dei riferimenti
per la maggior parte degli oggetti e *note garbage collection: 17c0. per
eliminare i cicli).  La memoria viene liberata poco dopo che l’ultimo
riferimento ad essa è stato eliminato.

Questo approccio funziona bene per la maggior parte delle applicazioni
ma occasionalmente è necessario tracciare gli oggetti solo finché
vengono utilizzati da qualcos’altro.  Sfortunatamente, solo il
tracciamento crea un riferimento che li rende permanenti.  Il modulo
*note weakref: 11a. fornisce strumenti per tracciare gli oggetti senza
creare un riferimento.  Quando l’oggetto non è più necessario, viene
automaticamente rimosso da una tabella weakref e viene attivato un
callback per gli oggetti weakref.  Applicazioni tipiche includono il
caching di oggetti costosi da creare:

     >>> import weakref, gc
     >>> class A:
     ...     def __init__(self, value):
     ...         self.value = value
     ...     def __repr__(self):
     ...         return str(self.value)
     ...
     >>> a = A(10)                   # create a reference
     >>> d = weakref.WeakValueDictionary()
     >>> d['primary'] = a            # does not create a reference
     >>> d['primary']                # fetch the object if it is still alive
     10
     >>> del a                       # remove the one reference
     >>> gc.collect()                # run garbage collection right away
     0
     >>> d['primary']                # entry was automatically removed
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
         d['primary']                # entry was automatically removed
       File "C:/python314/lib/weakref.py", line 46, in __getitem__
         o = self.data[key]()
     KeyError: 'primary'


File: python.info,  Node: Strumenti per Lavorare con Liste,  Next: Decimal Floating-Point Arithmetic,  Prev: Riferimenti Deboli,  Up: Giro Breve della Libreria Standard — Parte II

2.11.7 Strumenti per Lavorare con Liste
---------------------------------------

Molte necessità di strutture dati possono essere soddisfatte con il tipo
di lista integrato.  Tuttavia, a volte c’è bisogno di implementazioni
alternative con diversi compromessi di prestazioni.

The *note array: 8. module provides an *note array: 4bf. object that is
like a list that stores only homogeneous data and stores it more
compactly.  The following example shows an array of numbers stored as
two byte unsigned binary numbers (typecode ‘"H"’) rather than the usual
16 bytes per entry for regular lists of Python int objects:

     >>> from array import array
     >>> a = array('H', [4000, 10, 700, 22222])
     >>> sum(a)
     26932
     >>> a[1:3]
     array('H', [10, 700])

The *note collections: 1e. module provides a *note deque: 7f5. object
that is like a list with faster appends and pops from the left side but
slower lookups in the middle.  These objects are well suited for
implementing queues and breadth first tree searches:

     >>> from collections import deque
     >>> d = deque(["task1", "task2", "task3"])
     >>> d.append("task4")
     >>> print("Handling", d.popleft())
     Handling task1

     unsearched = deque([starting_node])
     def breadth_first_search(unsearched):
         node = unsearched.popleft()
         for m in gen_moves(node):
             if is_goal(m):
                 return m
             unsearched.append(m)

Oltre alle implementazioni alternative di liste, la libreria offre anche
altri strumenti come il modulo *note bisect: 12. con funzioni per
manipolare liste ordinate:

     >>> import bisect
     >>> scores = [(100, 'perl'), (200, 'tcl'), (400, 'lua'), (500, 'python')]
     >>> bisect.insort(scores, (300, 'ruby'))
     >>> scores
     [(100, 'perl'), (200, 'tcl'), (300, 'ruby'), (400, 'lua'), (500, 'python')]

Il modulo *note heapq: 6d. fornisce funzioni per implementare heap
basati su liste regolari.  L’ingresso a valore più basso viene sempre
mantenuto in posizione zero.  Questo è utile per applicazioni che
accedono ripetutamente all’elemento più piccolo ma non vogliono eseguire
un ordinamento completo della lista:

     >>> from heapq import heapify, heappop, heappush
     >>> data = [1, 3, 5, 7, 9, 2, 4, 6, 8, 0]
     >>> heapify(data)                      # rearrange the list into heap order
     >>> heappush(data, -5)                 # add a new entry
     >>> [heappop(data) for i in range(3)]  # fetch the three smallest entries
     [-5, 0, 1]


File: python.info,  Node: Decimal Floating-Point Arithmetic,  Prev: Strumenti per Lavorare con Liste,  Up: Giro Breve della Libreria Standard — Parte II

2.11.8 Decimal Floating-Point Arithmetic
----------------------------------------

The *note decimal: 3a. module offers a *note Decimal: 1fe. datatype for
decimal floating-point arithmetic.  Compared to the built-in *note
float: 196. implementation of binary floating point, the class is
especially helpful for

   * applicazioni finanziarie e altri usi che richiedono una
     rappresentazione decimale esatta,

   * controllo sulla precisione,

   * controllo sull’arrotondamento per soddisfare requisiti legali o
     normativi,

   * tracciamento delle cifre decimali significative, oppure

   * applicazioni in cui l’utente si aspetta che i risultati
     corrispondano ai calcoli fatti a mano.

Ad esempio, calcolare una tassa del 5% su una tariffa telefonica di 70
centesimi dà risultati diversi in decimale a virgola mobile e binario a
virgola mobile.  La differenza diventa significativa se i risultati
vengono arrotondati al centesimo più vicino:

     >>> from decimal import *
     >>> round(Decimal('0.70') * Decimal('1.05'), 2)
     Decimal('0.74')
     >>> round(.70 * 1.05, 2)
     0.73

Il risultato *note Decimal: 1fe. mantiene uno zero finale, inferendo
automaticamente una significatività a quattro posti dai fattori
moltiplicativi con significatività a due posti.  Decimale riproduce la
matematica fatta a mano ed evita problemi che possono sorgere quando la
virgola mobile binaria non può rappresentare esattamente quantità
decimali.

La rappresentazione esatta permette alla classe *note Decimal: 1fe. di
eseguire calcoli modulo e test di uguaglianza che sono inadatti per la
virgola mobile binaria:

     >>> Decimal('1.00') % Decimal('.10')
     Decimal('0.00')
     >>> 1.00 % 0.10
     0.09999999999999995

     >>> sum([Decimal('0.1')]*10) == Decimal('1.0')
     True
     >>> 0.1 + 0.1 + 0.1 + 0.1 + 0.1 + 0.1 + 0.1 + 0.1 + 0.1 + 0.1 == 1.0
     False

Il modulo *note decimal: 3a. fornisce aritmetica con precisione quanto
richiesta:

     >>> getcontext().prec = 36
     >>> Decimal(1) / Decimal(7)
     Decimal('0.142857142857142857142857142857142857')


File: python.info,  Node: Ambienti Virtuali e Pacchetti,  Next: E adesso?,  Prev: Giro Breve della Libreria Standard — Parte II,  Up: Tutorial su Python

2.12 Ambienti Virtuali e Pacchetti
==================================

* Menu:

* Introduzione::
* Creazione di Ambienti Virtuali::
* Gestione dei Pacchetti con pip::


File: python.info,  Node: Introduzione,  Next: Creazione di Ambienti Virtuali,  Up: Ambienti Virtuali e Pacchetti

2.12.1 Introduzione
-------------------

Le applicazioni Python spesso utilizzano pacchetti e moduli che non
fanno parte della libreria standard.  Le applicazioni a volte
necessitano una versione specifica di una libreria, perché
l’applicazione potrebbe richiedere che un bug particolare sia stato
risolto o l’applicazione potrebbe essere stata scritta utilizzando una
versione obsoleta dell’interfaccia della libreria.

Questo significa che potrebbe non essere possibile per una singola
installazione di Python soddisfare i requisiti di ogni applicazione.  Se
l’applicazione A necessita della versione 1.0 di un particolare modulo
ma l’applicazione B necessita della versione 2.0, allora i requisiti
sono in conflitto e l’installazione della versione 1.0 o 2.0 lascerà una
delle applicazioni impossibilitata a funzionare.

La soluzione a questo problema è creare un *note virtual environment:
20d7, un albero di directory auto-contenuto che contiene
un’installazione di Python per una particolare versione di Python, più
un numero di pacchetti aggiuntivi.

Differenti applicazioni possono quindi utilizzare differenti ambienti
virtuali.  Per risolvere l’esempio precedente di requisiti in conflitto,
l’applicazione A può avere il suo proprio ambiente virtuale con la
versione 1.0 installata mentre l’applicazione B ha un altro ambiente
virtuale con la versione 2.0.  Se l’applicazione B richiede che una
libreria venga aggiornata alla versione 3.0, questo non influenzerà
l’ambiente dell’applicazione A.


File: python.info,  Node: Creazione di Ambienti Virtuali,  Next: Gestione dei Pacchetti con pip,  Prev: Introduzione,  Up: Ambienti Virtuali e Pacchetti

2.12.2 Creazione di Ambienti Virtuali
-------------------------------------

Il modulo utilizzato per creare e gestire ambienti virtuali si chiama
*note venv: 117.  *note venv: 117. installerà la versione di Python
dalla quale il comando è stato eseguito (come riportato dall’opzione
*note -version: f19.).  Per esempio, eseguendo il comando con
‘python3.12’ verrà installata la versione 3.12.

Per creare un ambiente virtuale, decidi una directory dove vuoi
posizionarlo ed esegui il modulo *note venv: 117. come script con il
percorso della directory:

     python -m venv tutorial-env

Questo creerà la directory ‘tutorial-env’ se non esiste, e creerà anche
directory all’interno contenenti una copia dell’interprete Python e vari
file di supporto.

Una posizione comune per una directory di ambiente virtuale è ‘.venv’.
Questo nome mantiene la directory generalmente nascosta nella tua shell
e quindi fuori mano, dando anche un nome che spiega il motivo
dell’esistenza della directory.  Previene anche conflitti con file di
definizione di variabili d’ambiente ‘.env’ che alcuni strumenti
supportano.

Una volta creato un ambiente virtuale, puoi attivarlo.

Su Windows, esegui:

     tutorial-env\Scripts\activate

Su Unix o MacOS, esegui:

     source tutorial-env/bin/activate

(Questo script è scritto per la shell bash.  Se utilizzi le shell ‘csh’
o ‘fish’, ci sono script alternativi ‘activate.csh’ e ‘activate.fish’
che dovresti utilizzare.)

Attivare l’ambiente virtuale cambierà il prompt della tua shell per
mostrare quale ambiente virtuale stai utilizzando, e modificherà
l’ambiente in modo che eseguire ‘python’ ti fornirà quella versione e
installazione particolare di Python.  Per esempio:

     $ source ~/envs/tutorial-env/bin/activate
     (tutorial-env) $ python
     Python 3.5.1 (default, May  6 2016, 10:59:36)
       ...
     >>> import sys
     >>> sys.path
     ['', '/usr/local/lib/python35.zip', ...,
     '~/envs/tutorial-env/lib/python3.5/site-packages']
     >>>

Per disattivare un ambiente virtuale, scrivi:

     deactivate

nel terminale.


File: python.info,  Node: Gestione dei Pacchetti con pip,  Prev: Creazione di Ambienti Virtuali,  Up: Ambienti Virtuali e Pacchetti

2.12.3 Gestione dei Pacchetti con pip
-------------------------------------

Puoi installare, aggiornare e rimuovere pacchetti utilizzando un
programma chiamato ‘pip’.  Per impostazione predefinita ‘pip’ installerà
pacchetti dal Python Package Index(1).  Puoi sfogliare il Python Package
Index andando sul sito web con il tuo browser.

‘pip’ ha un certo numero di sottocomandi: «install», «uninstall»,
«freeze», etc.  (Consulta la guida *note Installing Python Modules:
10fa. per la documentazione completa su ‘pip’.)

Puoi installare l’ultima versione di un pacchetto specificando il nome
del pacchetto:

     (tutorial-env) $ python -m pip install novas
     Collecting novas
       Downloading novas-3.1.1.3.tar.gz (136kB)
     Installing collected packages: novas
       Running setup.py install for novas
     Successfully installed novas-3.1.1.3

Puoi anche installare una versione specifica di un pacchetto fornendo il
nome del pacchetto seguito da ‘==’ e dal numero di versione:

     (tutorial-env) $ python -m pip install requests==2.6.0
     Collecting requests==2.6.0
       Using cached requests-2.6.0-py2.py3-none-any.whl
     Installing collected packages: requests
     Successfully installed requests-2.6.0

Se esegui nuovamente questo comando, ‘pip’ noterà che la versione
richiesta è già installata e non farà nulla.  Puoi fornire un numero di
versione diverso per ottenere quella versione, oppure puoi eseguire
‘python -m pip install --upgrade’ per aggiornare il pacchetto all’ultima
versione:

     (tutorial-env) $ python -m pip install --upgrade requests
     Collecting requests
     Installing collected packages: requests
       Found existing installation: requests 2.6.0
         Uninstalling requests-2.6.0:
           Successfully uninstalled requests-2.6.0
     Successfully installed requests-2.7.0

‘python -m pip uninstall’ seguito da uno o più nomi di pacchetti
rimuoverà i pacchetti dall’ambiente virtuale.

‘python -m pip show’ mostrerà informazioni su un particolare pacchetto:

     (tutorial-env) $ python -m pip show requests
     ---
     Metadata-Version: 2.0
     Name: requests
     Version: 2.7.0
     Summary: Python HTTP for Humans.
     Home-page: http://python-requests.org
     Author: Kenneth Reitz
     Author-email: me@kennethreitz.com
     License: Apache 2.0
     Location: /Users/akuchling/envs/tutorial-env/lib/python3.4/site-packages
     Requires:

‘python -m pip list’ mostrerà tutti i pacchetti installati nell’ambiente
virtuale:

     (tutorial-env) $ python -m pip list
     novas (3.1.1.3)
     numpy (1.9.2)
     pip (7.0.3)
     requests (2.7.0)
     setuptools (16.0)

‘python -m pip freeze’ produrrà una lista simile dei pacchetti
installati, ma l’output utilizza il formato che ‘python -m pip install’
si aspetta.  Una convenzione comune è mettere questa lista in un file
‘requirements.txt’:

     (tutorial-env) $ python -m pip freeze > requirements.txt
     (tutorial-env) $ cat requirements.txt
     novas==3.1.1.3
     numpy==1.9.2
     requests==2.7.0

Il ‘requirements.txt’ può poi essere committato nel controllo di
versione e distribuito come parte di un’applicazione.  Gli utenti
possono poi installare tutti i pacchetti necessari con ‘install -r’:

     (tutorial-env) $ python -m pip install -r requirements.txt
     Collecting novas==3.1.1.3 (from -r requirements.txt (line 1))
       ...
     Collecting numpy==1.9.2 (from -r requirements.txt (line 2))
       ...
     Collecting requests==2.7.0 (from -r requirements.txt (line 3))
       ...
     Installing collected packages: novas, numpy, requests
       Running setup.py install for novas
     Successfully installed novas-3.1.1.3 numpy-1.9.2 requests-2.7.0

‘pip’ ha molte altre opzioni.  Consulta la guida *note Installing Python
Modules: 10fa. per la documentazione completa su ‘pip’.  Quando hai
scritto un pacchetto e vuoi renderlo disponibile su Python Package
Index, consulta la guida dell'utente al packaging di Python(2).

   ---------- Footnotes ----------

   (1) https://pypi.org

   (2) 
https://packaging.python.org/en/latest/tutorials/packaging-projects/


File: python.info,  Node: E adesso?,  Next: Editing dell’input interattivo e sostituzione della history,  Prev: Ambienti Virtuali e Pacchetti,  Up: Tutorial su Python

2.13 E adesso?
==============

Probabilmente la lettura di questo tutorial ha rafforzato il tuo
interesse nell’usare Python — dovresti essere desideroso di applicare
Python alla risoluzione dei tuoi problemi reali.  Dove dovresti andare
per imparare di più?

Questo tutorial fa parte della documentazione di Python.  Altri
documenti disponibili sono:

   * *note The Python Standard Library: 149.:

     Dovresti sfogliare questo manuale, che fornisce materiale di
     riferimento completo (anche se conciso) sui tipi, le funzioni e i
     moduli nella libreria standard.  La distribuzione standard di
     Python include 'molto' codice aggiuntivo.  Ci sono moduli per
     leggere caselle di posta Unix, recuperare documenti via HTTP,
     generare numeri casuali, analizzare opzioni da riga di comando,
     comprimere dati e molte altre attività.  Sfogliare il Reference
     della libreria ti darà un’idea di ciò che è disponibile.

   * *note Installing Python Modules: 10fa. spiega come installare
     moduli aggiuntivi scritti da altri utenti Python.

   * *note The Python Language Reference: 14a.: Una spiegazione
     dettagliata della sintassi e della semantica di Python.  È una
     lettura impegnativa, ma è utile come guida completa al linguaggio
     stesso.

Ulteriori risorse Python:

   * ‘https://www.python.org’: The major Python website.  It contains
     code, documentation, and pointers to Python-related pages around
     the web.

   * ‘https://docs.python.org’: Accesso rapido alla documentazione di
     Python.

   * ‘https://pypi.org’: L’Indice dei pacchetti Python, precedentemente
     anche soprannominato il Cheese Shop (1), è un indice di moduli
     Python creati dagli utenti che sono disponibili per il download.
     Una volta che inizi a rilasciare codice, puoi registrarlo qui in
     modo che altri possano trovarlo.

   * ‘https://code.activestate.com/recipes/langs/python/’: Il Python
     Cookbook è una vasta raccolta di esempi di codice, moduli più
     grandi e script utili.  Contributi particolarmente notevoli sono
     raccolti in un libro intitolato Python Cookbook (O’Reilly &
     Associates, ISBN 0-596-00797-3.)

   * ‘https://pyvideo.org’ raccoglie collegamenti a video relativi a
     Python da conferenze e riunioni di gruppi di utenti.

   * ‘https://scipy.org’: Il progetto Scientific Python include moduli
     per calcoli e manipolazioni di array veloci e una serie di
     pacchetti per attività come l’algebra lineare, le trasformate di
     Fourier, i risolutori non lineari, le distribuzioni di numeri
     casuali, l’analisi statistica e simili.

Per domande e segnalazioni di problemi relativi a Python, puoi inviare
un messaggio al newsgroup ‘comp.lang.python’, o inviarli alla mailing
list all’indirizzo <python-list@python.org>.  Il newsgroup e la mailing
list sono dei*gateway*, quindi i messaggi inviati a uno saranno
automaticamente inoltrati all’altro.  Ci sono centinaia di messaggi al
giorno, che pongono (e rispondono) domande, suggeriscono nuove
funzionalità e annunciano nuovi moduli.  Gli archivi della mailing list
sono disponibili su ‘https://mail.python.org/pipermail/’.

Prima di inviare un messaggio, assicurati di controllare l’elenco delle
*note Domande più frequenti: 20de. (chiamato anche FAQ). La FAQ risponde
a molte delle domande che vengono poste di nuovo e di nuovo, e potrebbe
già contenere la soluzione per il tuo problema.

   ---------- Footnotes ----------

   (1) «Cheese Shop» è uno sketch dei Monty Python: un cliente entra in
un negozio di formaggi, ma qualunque formaggio chieda, il commesso dice
che è finito.


File: python.info,  Node: Editing dell’input interattivo e sostituzione della history,  Next: Floating-Point Arithmetic Issues and Limitations,  Prev: E adesso?,  Up: Tutorial su Python

2.14 Editing dell’input interattivo e sostituzione della history
================================================================

Alcune versioni dell’interprete Python supportano la modifica della riga
di input corrente e la sostituzione della history, simili alle
funzionalità presenti nella shell Korn e nella shell GNU Bash.  Questo è
implementato utilizzando la libreria GNU Readline(1), che supporta vari
stili di modifica.  Questa libreria ha la sua documentazione che non
duplicheremo qui.

* Menu:

* Completamento con il tasto Tab e modifica della history::
* Alternative all’interprete interattivo::

   ---------- Footnotes ----------

   (1) https://tiswww.case.edu/php/chet/readline/rltop.html


File: python.info,  Node: Completamento con il tasto Tab e modifica della history,  Next: Alternative all’interprete interattivo,  Up: Editing dell’input interattivo e sostituzione della history

2.14.1 Completamento con il tasto Tab e modifica della history
--------------------------------------------------------------

Il completamento dei nomi delle variabili e dei moduli è *note
automaticamente abilitato: 11cb. all’avvio dell’interprete in modo che
il tasto ‘Tab’ invochi la funzione di completamento; essa esamina i nomi
delle istruzioni Python, le variabili locali correnti e i nomi dei
moduli disponibili.  Per le espressioni puntate come ‘string.a’,
valuterà l’espressione fino all’ultimo ‘'.'’ e quindi suggerirà
completamenti dagli attributi dell’oggetto risultante.  Nota che questo
potrebbe eseguire codice definito dall’applicazione se un oggetto con un
metodo *note __getattr__(): 6fb. fa parte dell’espressione.  La
configurazione predefinita salva anche la tua history in un file
chiamato ‘.python_history’ nella tua directory utente.  La history sarà
disponibile nuovamente durante la prossima sessione dell’interprete
interattivo.


File: python.info,  Node: Alternative all’interprete interattivo,  Prev: Completamento con il tasto Tab e modifica della history,  Up: Editing dell’input interattivo e sostituzione della history

2.14.2 Alternative all’interprete interattivo
---------------------------------------------

This facility is an enormous step forward compared to earlier versions
of the interpreter; however, some wishes are left: It would be nice if
the proper indentation were suggested on continuation lines (the parser
knows if an *note INDENT: 20e6. token is required next).  The completion
mechanism might use the interpreter’s symbol table.  A command to check
(or even suggest) matching parentheses, quotes, etc., would also be
useful.

Un’alternativa all’interprete interattivo migliorato che esiste da molto
tempo è IPython(1), che offre il completamento con il tasto Tab,
l’esplorazione degli oggetti e una gestione avanzata della history.  Può
anche essere personalizzato a fondo e incorporato in altre applicazioni.
Un altro ambiente interattivo migliorato simile è bpython(2).

   ---------- Footnotes ----------

   (1) https://ipython.org/

   (2) https://bpython-interpreter.org/


File: python.info,  Node: Floating-Point Arithmetic Issues and Limitations,  Next: Appendice,  Prev: Editing dell’input interattivo e sostituzione della history,  Up: Tutorial su Python

2.15 Floating-Point Arithmetic: Issues and Limitations
======================================================

I numeri in virgola mobile sono rappresentati nell’hardware del computer
come frazioni in base 2 (binari).  Ad esempio, la frazione 'decimale'
‘0.625’ ha valore 6/10 + 2/100 + 5/1000, e allo stesso modo la frazione
'binaria' ‘0.101’ ha valore 1/2 + 0/4 + 1/8.  Queste due frazioni hanno
valori identici, l’unica vera differenza è che la prima è scritta in
notazione frazionaria in base 10, e la seconda in base 2.

Sfortunatamente, la maggior parte delle frazioni decimali non può essere
rappresentata esattamente come frazioni binarie.  Una conseguenza è che,
in generale, i numeri in virgola mobile decimali che inserisci sono solo
approssimati dai numeri in virgola mobile binari effettivamente
memorizzati nella macchina.

Il problema è più facile da comprendere inizialmente in base 10.
Considera la frazione 1/3.  Puoi approssimarla come una frazione in base
10:

     0.3

o, meglio,

     0.33

o, meglio,

     0.333

e così via.  Non importa quanti cifre sei disposto a scrivere, il
risultato non sarà mai esattamente 1/3, ma sarà una approssimazione
sempre migliore di 1/3.

Allo stesso modo, non importa quante cifre in base 2 sei disposto a
usare, il valore decimale 0.1 non può essere rappresentato esattamente
come una frazione in base 2.  In base 2, 1/10 è la frazione che si
ripete all’infinito:

     0.0001100110011001100110011001100110011001100110011...

Fermati a un qualsiasi numero finito di bit, e otterrai
un’approssimazione.  Nella maggior parte delle macchine odierne, i float
sono approssimati usando una frazione binaria con il numeratore che
utilizza i primi 53 bit a partire dal bit più significativo e con il
denominatore come potenza di due.  Nel caso di 1/10, la frazione binaria
è ‘3602879701896397 / 2 ** 55’ che è vicino ma non esattamente uguale al
valore vero di 1/10.

Molti utenti non sono a conoscenza dell’approssimazione a causa del modo
in cui i valori sono visualizzati.  Python stampa solo
un’approssimazione decimale al valore decimale vero dell’approssimazione
binaria memorizzata nella macchina.  Nella maggior parte delle macchine,
se Python dovesse stampare il valore decimale vero dell’approssimazione
binaria memorizzata per 0.1, dovrebbe visualizzare:

     >>> 0.1
     0.1000000000000000055511151231257827021181583404541015625

Questo è un numero di cifre maggiore di quelle che la maggior parte
delle persone trova utile, quindi Python mantiene il numero di cifre
gestibile visualizzando invece un valore arrotondato:

     >>> 1 / 10
     0.1

Ricorda solo, anche se il risultato stampato sembra il valore esatto di
1/10, il valore effettivamente memorizzato è la frazione binaria
rappresentabile più vicina.

Interessante è che ci sono molti numeri decimali diversi che condividono
la stessa frazione binaria approssimata più vicina.  Ad esempio, i
numeri ‘0.1’ e ‘0.10000000000000001’ e
‘0.1000000000000000055511151231257827021181583404541015625’ sono tutti
approssimati da ‘3602879701896397 / 2 ** 55’.  Poiché tutti questi
valori decimali condividono la stessa approssimazione, qualsiasi di essi
potrebbe essere visualizzato pur mantenendo l’invariante ‘eval(repr(x))
== x’.

Storicamente, il prompt di Python e la funzione integrata *note repr():
1c1. avrebbero scelto quella con 17 cifre significative,
‘0.10000000000000001’.  A partire da Python 3.1, Python (sulla maggior
parte dei sistemi) è ora in grado di scegliere il più corto di questi e
visualizzare semplicemente ‘0.1’.

Note that this is in the very nature of binary floating point: this is
not a bug in Python, and it is not a bug in your code either.  You’ll
see the same kind of thing in all languages that support your hardware’s
floating-point arithmetic (although some languages may not 'display' the
difference by default, or in all output modes).

Per un output più gradevole, potresti voler usare la formattazione delle
stringhe per produrre un numero limitato di cifre significative:

     >>> format(math.pi, '.12g')  # give 12 significant digits
     '3.14159265359'

     >>> format(math.pi, '.2f')   # give 2 digits after the point
     '3.14'

     >>> repr(math.pi)
     '3.141592653589793'

È importante rendersi conto che questo è, in un certo senso,
un’illusione: stai semplicemente arrotondando la 'visualizzazione' del
vero valore della macchina.

Un’illusione può generare un’altra.  Ad esempio, poiché 0.1 non è
esattamente 1/10, sommare tre valori di 0.1 potrebbe non dare
esattamente 0.3, nemmeno:

     >>> 0.1 + 0.1 + 0.1 == 0.3
     False

Inoltre, poiché lo 0.1 non può avvicinarsi al valore esatto di 1/10 e lo
0.3 non può avvicinarsi al valore esatto di 3/10, il pre-arrotondamento
con la funzione *note round(): 14e2. non può aiutare:

     >>> round(0.1, 1) + round(0.1, 1) + round(0.1, 1) == round(0.3, 1)
     False

Anche se i numeri non possono essere resi più vicini ai loro valori
esatti previsti, la funzione *note math.isclose(): fb2. può essere utile
per confrontare valori inesatti:

     >>> math.isclose(0.1 + 0.1 + 0.1, 0.3)
     True

In alternativa, la funzione *note round(): 14e2. può essere utilizzata
per confrontare approssimazioni grossolane:

     >>> round(math.pi, ndigits=2) == round(22 / 7, ndigits=2)
     True

Binary floating-point arithmetic holds many surprises like this.  The
problem with «0.1» is explained in precise detail below, in the
«Representation Error» section.  See Examples of Floating Point
Problems(1) for a pleasant summary of how binary floating point works
and the kinds of problems commonly encountered in practice.  Also see
The Perils of Floating Point(2) for a more complete account of other
common surprises.

As that says near the end, «there are no easy answers.» Still, don’t be
unduly wary of floating point!  The errors in Python float operations
are inherited from the floating-point hardware, and on most machines are
on the order of no more than 1 part in 2**53 per operation.  That’s more
than adequate for most tasks, but you do need to keep in mind that it’s
not decimal arithmetic and that every float operation can suffer a new
rounding error.

Sebbene esistano casi patologici, per la maggior parte dell’uso
occasionale dell’aritmetica in virgola mobile otterrai il risultato che
ti aspetti alla fine se semplicemente arrotondi la visualizzazione dei
tuoi risultati finali al numero di cifre decimali che ti aspetti.  *note
str(): 169. di solito è sufficiente, e per un controllo più fine vedi
gli specificatori di formato del metodo *note str.format(): 834. in
*note Format String Syntax: 15a3.

Per utilizzi che richiedono una rappresentazione decimale esatta, prova
ad usare il modulo *note decimal: 3a. che implementa l’aritmetica
decimale adatta per applicazioni contabili e applicazioni ad alta
precisione.

Un’altra forma di aritmetica esatta è supportata dal modulo *note
fractions: 61. che implementa l’aritmetica basata su numeri razionali
(così i numeri come 1/3 possono essere rappresentati esattamente).

Se sei un utente assiduo delle operazioni in virgola mobile, dovresti
dare un’occhiata al pacchetto NumPy e a molti altri pacchetti per
operazioni matematiche e statistiche forniti dal progetto SciPy.  Vedi
<‘https://scipy.org’>.

Python fornisce strumenti che possono aiutare in quelle rare occasioni
in cui davvero 'vuoi' conoscere il valore esatto di un float.  Il metodo
*note float.as_integer_ratio(): 20eb. esprime il valore di un float come
una frazione:

     >>> x = 3.14159
     >>> x.as_integer_ratio()
     (3537115888337719, 1125899906842624)

Poiché il rapporto è esatto, può essere utilizzato per ricreare senza
perdita il valore originale:

     >>> x == 3537115888337719 / 1125899906842624
     True

Il metodo *note float.hex(): 20ec. esprime un float in esadecimale (base
16), dando ancora una volta il valore esatto memorizzato dal tuo
computer:

     >>> x.hex()
     '0x1.921f9f01b866ep+1'

Questa rappresentazione esadecimale precisa può essere utilizzata per
ricostruire il valore del float esattamente:

     >>> x == float.fromhex('0x1.921f9f01b866ep+1')
     True

Poiché la rappresentazione è esatta, è utile per trasferire valori in
modo affidabile tra diverse versioni di Python (indipendenza dalla
piattaforma) e scambiare dati con altri linguaggi che supportano lo
stesso formato (come Java e C99).

Un altro strumento utile è la funzione *note sum(): 696. che aiuta a
mitigare la perdita di precisione durante la somma.  Usa la precisione
estesa per i passaggi di arrotondamento intermedi man mano che i valori
vengono aggiunti a un totale incrementale.  Questo può fare la
differenza in termini di precisione complessiva in modo che gli errori
non si accumulino al punto da influenzare il totale finale:

     >>> 0.1 + 0.1 + 0.1 + 0.1 + 0.1 + 0.1 + 0.1 + 0.1 + 0.1 + 0.1 == 1.0
     False
     >>> sum([0.1] * 10) == 1.0
     True

The *note math.fsum(): 15db. goes further and tracks all of the «lost
digits» as values are added onto a running total so that the result has
only a single rounding.  This is slower than *note sum(): 696. but will
be more accurate in uncommon cases where large magnitude inputs mostly
cancel each other out leaving a final sum near zero:

     >>> arr = [-0.10430216751806065, -266310978.67179024, 143401161448607.16,
     ...        -143401161400469.7, 266262841.31058735, -0.003244936839808227]
     >>> float(sum(map(Fraction, arr)))   # Exact summation with single rounding
     8.042173697819788e-13
     >>> math.fsum(arr)                   # Single rounding
     8.042173697819788e-13
     >>> sum(arr)                         # Multiple roundings in extended precision
     8.042178034628478e-13
     >>> total = 0.0
     >>> for x in arr:
     ...     total += x                   # Multiple roundings in standard precision
     ...
     >>> total                            # Straight addition has no correct digits!
     -0.0051575902860057365

* Menu:

* Errore di Rappresentazione::

   ---------- Footnotes ----------

   (1) 
https://jvns.ca/blog/2023/01/13/examples-of-floating-point-problems/

   (2) http://www.indowsway.com/floatingpoint.htm


File: python.info,  Node: Errore di Rappresentazione,  Up: Floating-Point Arithmetic Issues and Limitations

2.15.1 Errore di Rappresentazione
---------------------------------

Questa sezione spiega l’esempio «0.1» in dettaglio, e mostra come puoi
eseguire un’analisi esatta di casi come questo da solo.  Si assume una
familiarità di base con la rappresentazione in virgola mobile binaria.

'Errore di rappresentazione' si riferisce al fatto che alcune (anzi, la
maggior parte) delle frazioni decimali non possono essere rappresentate
esattamente come frazioni binarie (base 2).  Questa è la principale
ragione per cui Python (o Perl, C, C++, Java, Fortran e molti altri)
spesso non visualizzeranno il numero decimale esatto che ti aspetti.

Perché questo?  1/10 non è esattamente rappresentabile come frazione
binaria.  Dal 2000 in poi, quasi tutte le macchine utilizzano
l’aritmetica in virgola mobile binaria IEEE 754, e quasi tutte le
piattaforme mappano i float di Python ai valori «doppia precisione» IEEE
754 binary64.  I valori IEEE 754 binary64 contengono 53 bit di
precisione, quindi in input il computer cerca di convertire 0.1 nella
frazione più vicina della forma 'J'/2**'N' dove 'J' è un intero
contenente esattamente 53 bit.  Riscrivendo:

     1 / 10 ~= J / (2**N)

come:

     J ~= 2**N / 10

e ricordando che 'J' ha esattamente 53 bit (è ‘>= 2**52’ ma ‘< 2**53’),
il miglior valore per 'N' è 56:

     >>> 2**52 <=  2**56 // 10  < 2**53
     True

Cioè, 56 è l’unico valore per 'N' che lascia 'J' con esattamente 53 bit.
Il miglior valore possibile per 'J' è quindi quel quoziente arrotondato:

     >>> q, r = divmod(2**56, 10)
     >>> r
     6

Poiché il resto è più della metà di 10, la migliore approssimazione si
ottiene arrotondando verso l’alto:

     >>> q+1
     7205759403792794

Pertanto la migliore approssimazione possibile di 1/10 in doppia
precisione IEEE 754 è:

     7205759403792794 / 2 ** 56

Dividendo sia il numeratore che il denominatore per due si riduce la
frazione a:

     3602879701896397 / 2 ** 55

Nota che poiché abbiamo arrotondato verso l’alto, questo è in realtà un
po” più grande di 1/10; se non avessimo arrotondato verso l’alto, il
quoziente sarebbe stato un po” più piccolo di 1/10.  Ma in nessun caso
può essere 'esattamente' 1/10!

Quindi il computer non «vede» mai 1/10: quello che vede è la frazione
esatta data sopra, la migliore approssimazione doppia precisione IEEE
754 che può ottenere:

     >>> 0.1 * 2 ** 55
     3602879701896397.0

Se moltiplichiamo quella frazione per 10**55, possiamo vedere il valore
fino a 55 cifre decimali:

     >>> 3602879701896397 * 10 ** 55 // 2 ** 55
     1000000000000000055511151231257827021181583404541015625

il che significa che il numero esatto memorizzato nel computer è pari al
valore decimale
0.1000000000000000055511151231257827021181583404541015625.  Invece di
visualizzare il valore decimale completo, molti linguaggi (compresi le
vecchie versioni di Python), arrotondano il risultato a 17 cifre
significative:

     >>> format(0.1, '.17f')
     '0.10000000000000001'

I moduli *note fractions: 61. e *note decimal: 3a. rendono questi
calcoli facili:

     >>> from decimal import Decimal
     >>> from fractions import Fraction

     >>> Fraction.from_float(0.1)
     Fraction(3602879701896397, 36028797018963968)

     >>> (0.1).as_integer_ratio()
     (3602879701896397, 36028797018963968)

     >>> Decimal.from_float(0.1)
     Decimal('0.1000000000000000055511151231257827021181583404541015625')

     >>> format(Decimal.from_float(0.1), '.17')
     '0.10000000000000001'


File: python.info,  Node: Appendice,  Prev: Floating-Point Arithmetic Issues and Limitations,  Up: Tutorial su Python

2.16 Appendice
==============

* Menu:

* Modalità Interattiva: Modalità Interattiva<2>.


File: python.info,  Node: Modalità Interattiva<2>,  Up: Appendice

2.16.1 Modalità Interattiva
---------------------------

Ci sono due varianti del *note REPL: 492. interattivo.  L’interprete di
base classico è supportato su tutte le piattaforme con capacità minime
di controllo di riga.

Since Python 3.13, a new interactive shell is used by default.  This one
supports color, multiline editing, history browsing, and paste mode.  To
disable color, see *note Controlling color: 1b7. for details.  Function
keys provide some additional functionality.  ‘F1’ enters the interactive
help browser *note pydoc: ba.  ‘F2’ allows for browsing command-line
history with neither output nor the *note >>>: 493. and *note …: 494.
prompts.  ‘F3’ enters «paste mode», which makes pasting larger blocks of
code easier.  Press ‘F3’ to return to the regular prompt.

Quando si utilizza la nuova shell interattiva, si può uscire dalla shell
digitando ‘exit’ o ‘quit’.  Non è necessario aggiungere le parentesi di
chiamata dopo questi comandi.

Se non si vuole usare la nuova shell interattiva, questa può essere
disabilitata tramite la variabile di ambiente *note PYTHON_BASIC_REPL:
1b6.

* Menu:

* Gestione degli Errori::
* Script Eseguibili Python::
* Il File di Avvio Interattivo::
* I Moduli di Personalizzazione::


File: python.info,  Node: Gestione degli Errori,  Next: Script Eseguibili Python,  Up: Modalità Interattiva<2>

2.16.1.1 Gestione degli Errori
..............................

Quando si verifica un errore, l’interprete stampa un messaggio di errore
e una traccia dello stack.  In modalità interattiva, quindi ritorna al
prompt principale; quando l’input proviene da un file, esce con uno
stato di uscita diverso da zero dopo aver stampato la traccia dello
stack.  (Le eccezioni gestite da una clausola *note except: 1ab. in
un’istruzione *note try: 8f9. non sono errori in questo contesto.)
Alcuni errori sono incondizionatamente fatali e causano un’uscita con
uno stato di uscita diverso da zero; questo si applica alle incoerenze
interne e a certi casi di esaurimento della memoria.  Tutti i messaggi
di errore sono scritti sul flusso standard degli errori; l’output
normale dei comandi eseguiti è scritto sul flusso standard dell’output.

Digitare il carattere d’interruzione (di solito ‘Control’-‘C’ o
‘Delete’) al prompt principale o secondario cancella l’input e ritorna
al prompt principale.  (1)  Digitando un’interruzione mentre un comando
è in esecuzione si solleva l’eccezione *note KeyboardInterrupt: bc7, che
può essere gestita da un’istruzione *note try: 8f9.

   ---------- Footnotes ----------

   (1) Un problema con il pacchetto GNU Readline potrebbe impedirlo.


File: python.info,  Node: Script Eseguibili Python,  Next: Il File di Avvio Interattivo,  Prev: Gestione degli Errori,  Up: Modalità Interattiva<2>

2.16.1.2 Script Eseguibili Python
.................................

Nei sistemi Unix di tipo BSD, gli script Python possono essere resi
direttamente eseguibili, come gli script di shell, aggiungendo la riga

     #!/usr/bin/env python3

(supponendo che l’interprete sia nel ‘PATH’ dell’utente) all’inizio
dello script e dando al file un permesso eseguibile.  Il ‘#!’ deve
essere i primi due caratteri del file.  Su alcune piattaforme, questa
prima riga deve terminare con un fine riga in stile Unix (‘'\n'’), non
con un fine riga in stile Windows (‘'\r\n'’).  Nota che il carattere
cancelleto, ‘'#'’, è usato per iniziare un commento in Python.

Lo script può essere reso eseguibile, o avere i permessi, usando il
comando ‘chmod’.

     $ chmod +x myscript.py

Nei sistemi Windows, non esiste il concetto di «modalità eseguibile».
L’installatore Python associa automaticamente i file ‘.py’ con
‘python.exe’ in modo che un doppio clic su un file Python lo esegua come
uno script.  L’estensione può anche essere ‘.pyw’; in tal caso, la
finestra della console che appare normalmente viene soppressa.


File: python.info,  Node: Il File di Avvio Interattivo,  Next: I Moduli di Personalizzazione,  Prev: Script Eseguibili Python,  Up: Modalità Interattiva<2>

2.16.1.3 Il File di Avvio Interattivo
.....................................

Quando usi Python in modalità interattiva, è spesso utile avere alcuni
comandi standard eseguiti ogni volta che l’interprete viene avviato.
Puoi fare ciò impostando una variabile di ambiente chiamata *note
PYTHONSTARTUP: 1b8. al nome di un file contenente i tuoi comandi di
avvio.  Questo è simile alla funzionalità ‘.profile’ delle shell Unix.

Questo file viene letto solo nelle sessioni interattive, non quando
Python legge i comandi da uno script, e non quando ‘/dev/tty’ è dato
come fonte esplicita dei comandi (che altrimenti si comporta come una
sessione interattiva).  Viene eseguito nello stesso namespace dove
vengono eseguiti i comandi interattivi, quindi gli oggetti che definisce
o importa possono essere usati senza qualificazioni nella sessione
interattiva.  Puoi anche cambiare i prompt ‘sys.ps1’ e ‘sys.ps2’ in
questo file.

Se vuoi leggere un file di avvio aggiuntivo dalla directory corrente,
puoi programmare questo nel file di avvio globale usando il codice come
‘if os.path.isfile('.pythonrc.py'): exec(open('.pythonrc.py').read())’.
Se vuoi usare il file di avvio in uno script, devi farlo esplicitamente
nello script:

     import os
     filename = os.environ.get('PYTHONSTARTUP')
     if filename and os.path.isfile(filename):
         with open(filename) as fobj:
             startup_file = fobj.read()
         exec(startup_file)


File: python.info,  Node: I Moduli di Personalizzazione,  Prev: Il File di Avvio Interattivo,  Up: Modalità Interattiva<2>

2.16.1.4 I Moduli di Personalizzazione
......................................

Python fornisce due hook per permetterti di personalizzarlo:
sitecustomize e usercustomize.  Per vedere come funziona, devi prima
trovare la posizione della directory user site-packages.  Avvia Python
ed esegui questo codice:

     >>> import site
     >>> site.getusersitepackages()
     '/home/user/.local/lib/python3.x/site-packages'

Ora puoi creare un file chiamato ‘usercustomize.py’ in quella directory
e inserire ciò che vuoi in esso.  Questo influenzerà ogni invocazione di
Python, a meno che non sia avviato con l’opzione *note -s: 1596. per
disabilitare l’importazione automatica.

sitecustomize funziona allo stesso modo, ma è tipicamente creato da un
amministratore del computer nella directory globale site-packages e
viene importato prima di usercustomize.  Per maggiori dettagli, vedi la
documentazione del modulo *note site: cc.

Note a pie” di pagina
.....................


File: python.info,  Node: Python Setup and Usage,  Next: The Python Language Reference,  Prev: Tutorial su Python,  Up: Top

3 Python Setup and Usage
************************

This part of the documentation is devoted to general information on the
setup of the Python environment on different platforms, the invocation
of the interpreter and things that make working with Python easier.

* Menu:

* Command line and environment: Command line and environment<2>.
* Using Python on Unix platforms::
* Configure Python::
* Using Python on Windows::
* Using Python on macOS::
* Using Python on Android::
* Using Python on iOS::
* Editors and IDEs::


File: python.info,  Node: Command line and environment<2>,  Next: Using Python on Unix platforms,  Up: Python Setup and Usage

3.1 Command line and environment
================================

The CPython interpreter scans the command line and the environment for
various settings.

'Dettaglio dell’implementazione di CPython:' Other implementations”
command line schemes may differ.  See *note Alternate Implementations:
2101. for further resources.

* Menu:

* Command line::
* Environment variables::


File: python.info,  Node: Command line,  Next: Environment variables,  Up: Command line and environment<2>

3.1.1 Command line
------------------

When invoking Python, you may specify any of these options:

     python [-bBdEhiIOPqRsSuvVWx?] [-c command | -m module-name | script | - ] [args]

The most common use case is, of course, a simple invocation of a script:

     python myscript.py

* Menu:

* Interface options::
* Generic options::
* Miscellaneous options::
* Controlling color::


File: python.info,  Node: Interface options,  Next: Generic options,  Up: Command line

3.1.1.1 Interface options
.........................

The interpreter interface resembles that of the UNIX shell, but provides
some additional methods of invocation:

   * When called with standard input connected to a tty device, it
     prompts for commands and executes them until an EOF (an end-of-file
     character, you can produce that with ‘Ctrl’-‘D’ on UNIX or
     ‘Ctrl’-‘Z,’ ‘Enter’ on Windows) is read.  For more on interactive
     mode, see *note Modalità Interattiva: 495.

   * When called with a file name argument or with a file as standard
     input, it reads and executes a script from that file.

   * When called with a directory name argument, it reads and executes
     an appropriately named script from that directory.

   * When called with ‘-c command’, it executes the Python statement(s)
     given as 'command'.  Here 'command' may contain multiple statements
     separated by newlines.  Leading whitespace is significant in Python
     statements!

   * When called with ‘-m module-name’, the given module is located on
     the Python module path and executed as a script.

In non-interactive mode, the entire input is parsed before it is
executed.

An interface option terminates the list of options consumed by the
interpreter, all consecutive arguments will end up in *note sys.argv:
146c. – note that the first element, subscript zero (‘sys.argv[0]’), is
a string reflecting the program’s source.

 -- Option: -c <command>

     Execute the Python code in 'command'.  'command' can be one or more
     statements separated by newlines, with significant leading
     whitespace as in normal module code.

     If this option is given, the first element of *note sys.argv: 146c.
     will be ‘"-c"’ and the current directory will be added to the start
     of *note sys.path: 3e4. (allowing modules in that directory to be
     imported as top level modules).

     Raises an *note auditing event: 1c56. ‘cpython.run_command’ with
     argument ‘command’.

     Cambiato nella versione 3.14: 'command' is automatically dedented
     before execution.

 -- Option: -m <module-name>

     Search *note sys.path: 3e4. for the named module and execute its
     contents as the *note __main__: 1. module.

     Since the argument is a 'module' name, you must not give a file
     extension (‘.py’).  The module name should be a valid absolute
     Python module name, but the implementation may not always enforce
     this (e.g.  it may allow you to use a name that includes a hyphen).

     Package names (including namespace packages) are also permitted.
     When a package name is supplied instead of a normal module, the
     interpreter will execute ‘<pkg>.__main__’ as the main module.  This
     behaviour is deliberately similar to the handling of directories
     and zipfiles that are passed to the interpreter as the script
     argument.

          Nota: This option cannot be used with built-in modules and
          extension modules written in C, since they do not have Python
          module files.  However, it can still be used for precompiled
          modules, even if the original source file is not available.

     If this option is given, the first element of *note sys.argv: 146c.
     will be the full path to the module file (while the module file is
     being located, the first element will be set to ‘"-m"’).  As with
     the *note -c: 1a8. option, the current directory will be added to
     the start of *note sys.path: 3e4.

     *note -I: b59. option can be used to run the script in isolated
     mode where *note sys.path: 3e4. contains neither the current
     directory nor the user’s site-packages directory.  All ‘PYTHON*’
     environment variables are ignored, too.

     Many standard library modules contain code that is invoked on their
     execution as a script.  An example is the *note timeit: f5. module:

          python -m timeit -s "setup here" "benchmarked code here"
          python -m timeit -h # for details

     Raises an *note auditing event: 1c56. ‘cpython.run_module’ with
     argument ‘module-name’.

     Vedi anche
     ..........

     *note runpy.run_module(): 1b7f.

          Equivalent functionality directly available to Python code

     PEP 338(1) – Executing modules as scripts

     Cambiato nella versione 3.1: Supply the package name to run a
     ‘__main__’ submodule.

     Cambiato nella versione 3.4: namespace packages are also supported

 -- Describe: -

     Read commands from standard input (*note sys.stdin: 760.).  If
     standard input is a terminal, *note -i: 16e2. is implied.

     If this option is given, the first element of *note sys.argv: 146c.
     will be ‘"-"’ and the current directory will be added to the start
     of *note sys.path: 3e4.

     Raises an *note auditing event: 1c56. ‘cpython.run_stdin’ with no
     arguments.

 -- Describe: <script>

     Execute the Python code contained in 'script', which must be a
     filesystem path (absolute or relative) referring to either a Python
     file, a directory containing a ‘__main__.py’ file, or a zipfile
     containing a ‘__main__.py’ file.

     If this option is given, the first element of *note sys.argv: 146c.
     will be the script name as given on the command line.

     If the script name refers directly to a Python file, the directory
     containing that file is added to the start of *note sys.path: 3e4,
     and the file is executed as the *note __main__: 1. module.

     If the script name refers to a directory or zipfile, the script
     name is added to the start of *note sys.path: 3e4. and the
     ‘__main__.py’ file in that location is executed as the *note
     __main__: 1. module.

     *note -I: b59. option can be used to run the script in isolated
     mode where *note sys.path: 3e4. contains neither the script’s
     directory nor the user’s site-packages directory.  All ‘PYTHON*’
     environment variables are ignored, too.

     Raises an *note auditing event: 1c56. ‘cpython.run_file’ with
     argument ‘filename’.

     Vedi anche
     ..........

     *note runpy.run_path(): 4a5.

          Equivalent functionality directly available to Python code

If no interface option is given, *note -i: 16e2. is implied,
‘sys.argv[0]’ is an empty string (‘""’) and the current directory will
be added to the start of *note sys.path: 3e4.  Also, tab-completion and
history editing is automatically enabled, if available on your platform
(see *note Readline configuration: 11cb.).

Vedi anche
..........

*note Invocazione dell’interprete: 1fb0.

Cambiato nella versione 3.4: Automatic enabling of tab-completion and
history editing.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0338/


File: python.info,  Node: Generic options,  Next: Miscellaneous options,  Prev: Interface options,  Up: Command line

3.1.1.2 Generic options
.......................

 -- Option: -?
 -- Option: -h
 -- Option: --help

     Print a short description of all command line options and
     corresponding environment variables and exit.

 -- Option: --help-env

     Print a short description of Python-specific environment variables
     and exit.

     Added in version 3.11.

 -- Option: --help-xoptions

     Print a description of implementation-specific *note -X: 16f.
     options and exit.

     Added in version 3.11.

 -- Option: --help-all

     Print complete usage information and exit.

     Added in version 3.11.

 -- Option: -V
 -- Option: --version

     Print the Python version number and exit.  Example output could be:

          Python 3.8.0b2+

     When given twice, print more information about the build, like:

          Python 3.8.0b2+ (3.8:0c076caaa8, Apr 20 2019, 21:55:00)
          [GCC 6.2.0 20161005]

     Added in version 3.6: The ‘-VV’ option.


File: python.info,  Node: Miscellaneous options,  Next: Controlling color,  Prev: Generic options,  Up: Command line

3.1.1.3 Miscellaneous options
.............................

 -- Option: -b

     Issue a warning when converting *note bytes: 192. or *note
     bytearray: 344. to *note str: 169. without specifying encoding or
     comparing ‘bytes’ or ‘bytearray’ with ‘str’ or ‘bytes’ with *note
     int: 19b.  Issue an error when the option is given twice (‘-bb’).

     Cambiato nella versione 3.5: Affects also comparisons of *note
     bytes: 192. with *note int: 19b.

 -- Option: -B

     If given, Python won’t try to write ‘.pyc’ files on the import of
     source modules.  See also *note PYTHONDONTWRITEBYTECODE: 15d5.

 -- Option: --check-hash-based-pycs default|always|never

     Control the validation behavior of hash-based ‘.pyc’ files.  See
     *note Cached bytecode invalidation: 803.  When set to ‘default’,
     checked and unchecked hash-based bytecode cache files are validated
     according to their default semantics.  When set to ‘always’, all
     hash-based ‘.pyc’ files, whether checked or unchecked, are
     validated against their corresponding source file.  When set to
     ‘never’, hash-based ‘.pyc’ files are not validated against their
     corresponding source files.

     The semantics of timestamp-based ‘.pyc’ files are unaffected by
     this option.

 -- Option: -d

     Turn on parser debugging output (for expert only).  See also the
     *note PYTHONDEBUG: 210d. environment variable.

     This option requires a *note debug build of Python: 50a, otherwise
     it’s ignored.

 -- Option: -E

     Ignore all ‘PYTHON*’ environment variables, e.g.  *note PYTHONPATH:
     121f. and *note PYTHONHOME: 3f0, that might be set.

     See also the *note -P: 7c2. and *note -I: b59. (isolated) options.

 -- Option: -i

     Enter interactive mode after execution.

     Using the *note -i: 16e2. option will enter interactive mode in any
     of the following circumstances:

        * When a script is passed as first argument

        * When the *note -c: 1a8. option is used

        * When the *note -m: 23c. option is used

     Interactive mode will start even when *note sys.stdin: 760. does
     not appear to be a terminal.  The *note PYTHONSTARTUP: 1b8. file is
     not read.

     This can be useful to inspect global variables or a stack trace
     when a script raises an exception.  See also *note PYTHONINSPECT:
     16e1.

 -- Option: -I

     Run Python in isolated mode.  This also implies *note -E: b58,
     *note -P: 7c2. and *note -s: 1596. options.

     In isolated mode *note sys.path: 3e4. contains neither the script’s
     directory nor the user’s site-packages directory.  All ‘PYTHON*’
     environment variables are ignored, too.  Further restrictions may
     be imposed to prevent the user from injecting malicious code.

     Added in version 3.4.

 -- Option: -O

     Remove assert statements and any code conditional on the value of
     *note __debug__: 9dc.  Augment the filename for compiled (*note
     bytecode: 4ab.) files by adding ‘.opt-1’ before the ‘.pyc’
     extension (see PEP 488(1)).  See also *note PYTHONOPTIMIZE: 210e.

     Cambiato nella versione 3.5: Modify ‘.pyc’ filenames according to
     PEP 488(2).

 -- Option: -OO

     Do *note -O: 18c. and also discard docstrings.  Augment the
     filename for compiled (*note bytecode: 4ab.) files by adding
     ‘.opt-2’ before the ‘.pyc’ extension (see PEP 488(3)).

     Cambiato nella versione 3.5: Modify ‘.pyc’ filenames according to
     PEP 488(4).

 -- Option: -P

     Don’t prepend a potentially unsafe path to *note sys.path: 3e4.:

        * ‘python -m module’ command line: Don’t prepend the current
          working directory.

        * ‘python script.py’ command line: Don’t prepend the script’s
          directory.  If it’s a symbolic link, resolve symbolic links.

        * ‘python -c code’ and ‘python’ (REPL) command lines: Don’t
          prepend an empty string, which means the current working
          directory.

     See also the *note PYTHONSAFEPATH: 7c3. environment variable, and
     *note -E: b58. and *note -I: b59. (isolated) options.

     Added in version 3.11.

 -- Option: -q

     Don’t display the copyright and version messages even in
     interactive mode.

     Added in version 3.2.

 -- Option: -R

     Turn on hash randomization.  This option only has an effect if the
     *note PYTHONHASHSEED: 127f. environment variable is set to anything
     other than ‘random’, since hash randomization is enabled by
     default.

     On previous versions of Python, this option turns on hash
     randomization, so that the *note __hash__(): cf5. values of str and
     bytes objects are «salted» with an unpredictable random value.
     Although they remain constant within an individual Python process,
     they are not predictable between repeated invocations of Python.

     Hash randomization is intended to provide protection against a
     denial-of-service caused by carefully chosen inputs that exploit
     the worst case performance of a dict construction, 'O'('n'^2)
     complexity.  See ‘http://ocert.org/advisories/ocert-2011-003.html’
     for details.

     *note PYTHONHASHSEED: 127f. allows you to set a fixed value for the
     hash seed secret.

     Added in version 3.2.3.

     Cambiato nella versione 3.7: The option is no longer ignored.

 -- Option: -s

     Don’t add the *note user site-packages directory: 210f. to *note
     sys.path: 3e4.

     See also *note PYTHONNOUSERSITE: 1597.

     Vedi anche
     ..........

     PEP 370(5) – Per user site-packages directory

 -- Option: -S

     Disable the import of the module *note site: cc. and the
     site-dependent manipulations of *note sys.path: 3e4. that it
     entails.  Also disable these manipulations if *note site: cc. is
     explicitly imported later (call *note site.main(): 2110. if you
     want them to be triggered).

 -- Option: -u

     Force the stdout and stderr streams to be unbuffered.  This option
     has no effect on the stdin stream.

     See also *note PYTHONUNBUFFERED: 1d76.

     Cambiato nella versione 3.7: The text layer of the stdout and
     stderr streams now is unbuffered.

 -- Option: -v

     Print a message each time a module is initialized, showing the
     place (filename or built-in module) from which it is loaded.  When
     given twice (‘-vv’), print a message for each file that is checked
     for when searching for a module.  Also provides information on
     module cleanup at exit.

     Cambiato nella versione 3.10: The *note site: cc. module reports
     the site-specific paths and ‘.pth’ files being processed.

     See also *note PYTHONVERBOSE: 2111.

 -- Option: -W arg

     Warning control.  Python’s warning machinery by default prints
     warning messages to *note sys.stderr: b35.

     The simplest settings apply a particular action unconditionally to
     all warnings emitted by a process (even those that are otherwise
     ignored by default):

          -Wdefault  # Warn once per call location
          -Werror    # Convert to exceptions
          -Walways   # Warn every time
          -Wall      # Same as -Walways
          -Wmodule   # Warn once per calling module
          -Wonce     # Warn once per Python process
          -Wignore   # Never warn

     The action names can be abbreviated as desired and the interpreter
     will resolve them to the appropriate action name.  For example,
     ‘-Wi’ is the same as ‘-Wignore’.

     The full form of argument is:

          action:message:category:module:lineno

     Empty fields match all values; trailing empty fields may be
     omitted.  For example ‘-W ignore::DeprecationWarning’ ignores all
     DeprecationWarning warnings.

     The 'action' field is as explained above but only applies to
     warnings that match the remaining fields.

     The 'message' field must match the whole warning message; this
     match is case-insensitive.

     The 'category' field matches the warning category (ex:
     ‘DeprecationWarning’).  This must be a class name; the match test
     whether the actual warning category of the message is a subclass of
     the specified warning category.

     The 'module' field matches the (fully qualified) module name; this
     match is case-sensitive.

     The 'lineno' field matches the line number, where zero matches all
     line numbers and is thus equivalent to an omitted line number.

     Multiple *note -W: ac7. options can be given; when a warning
     matches more than one option, the action for the last matching
     option is performed.  Invalid *note -W: ac7. options are ignored
     (though, a warning message is printed about invalid options when
     the first warning is issued).

     Warnings can also be controlled using the *note PYTHONWARNINGS:
     da5. environment variable and from within a Python program using
     the *note warnings: 118. module.  For example, the *note
     warnings.filterwarnings(): 16b0. function can be used to use a
     regular expression on the warning message.

     See *note The Warnings Filter: 1b1. and *note Describing Warning
     Filters: 2113. for more details.

 -- Option: -x

     Skip the first line of the source, allowing use of non-Unix forms
     of ‘#!cmd’.  This is intended for a DOS specific hack only.

 -- Option: -X

     Reserved for various implementation-specific options.  CPython
     currently defines the following possible values:

        * ‘-X faulthandler’ to enable *note faulthandler: 5c.  See also
          *note PYTHONFAULTHANDLER: 1287.

          Added in version 3.3.

        * ‘-X showrefcount’ to output the total reference count and
          number of used memory blocks when the program finishes or
          after each statement in the interactive interpreter.  This
          only works on *note debug builds: 50a.

          Added in version 3.4.

        * ‘-X tracemalloc’ to start tracing Python memory allocations
          using the *note tracemalloc: 105. module.  By default, only
          the most recent frame is stored in a traceback of a trace.
          Use ‘-X tracemalloc=NFRAME’ to start tracing with a traceback
          limit of 'NFRAME' frames.  See *note tracemalloc.start():
          2115. and *note PYTHONTRACEMALLOC: 2116. for more information.

          Added in version 3.4.

        * ‘-X int_max_str_digits’ configures the *note integer string
          conversion length limitation: 80c.  See also *note
          PYTHONINTMAXSTRDIGITS: 1b22.

          Added in version 3.11.

        * ‘-X importtime’ to show how long each import takes.  It shows
          module name, cumulative time (including nested imports) and
          self time (excluding nested imports).  Note that its output
          may be broken in multi-threaded application.  Typical usage is
          ‘python -X importtime -c 'import asyncio'’.

          ‘-X importtime=2’ enables additional output that indicates
          when an imported module has already been loaded.  In such
          cases, the string ‘cached’ will be printed in both time
          columns.

          See also *note PYTHONPROFILEIMPORTTIME: cef.

          Added in version 3.7.

          Cambiato nella versione 3.14: Added ‘-X importtime=2’ to also
          trace imports of loaded modules, and reserved values other
          than ‘1’ and ‘2’ for future use.

        * ‘-X dev’: enable *note Python Development Mode: 509,
          introducing additional runtime checks that are too expensive
          to be enabled by default.  See also *note PYTHONDEVMODE: ce9.

          Added in version 3.7.

        * ‘-X utf8’ enables the *note Python UTF-8 Mode: 867.  ‘-X
          utf8=0’ explicitly disables *note Python UTF-8 Mode: 867.
          (even when it would otherwise activate automatically).  See
          also *note PYTHONUTF8: cd1.

          Added in version 3.7.

        * ‘-X pycache_prefix=PATH’ enables writing ‘.pyc’ files to a
          parallel tree rooted at the given directory instead of to the
          code tree.  See also *note PYTHONPYCACHEPREFIX: b9d.

          Added in version 3.8.

        * ‘-X warn_default_encoding’ issues a *note EncodingWarning:
          2117. when the locale-specific default encoding is used for
          opening files.  See also *note PYTHONWARNDEFAULTENCODING: 9c1.

          Added in version 3.10.

        * ‘-X no_debug_ranges’ disables the inclusion of the tables
          mapping extra location information (end line, start column
          offset and end column offset) to every instruction in code
          objects.  This is useful when smaller code objects and pyc
          files are desired as well as suppressing the extra visual
          location indicators when the interpreter displays tracebacks.
          See also *note PYTHONNODEBUGRANGES: 7d4.

          Added in version 3.11.

        * ‘-X frozen_modules’ determines whether or not frozen modules
          are ignored by the import machinery.  A value of ‘on’ means
          they get imported and ‘off’ means they are ignored.  The
          default is ‘on’ if this is an installed Python (the normal
          case).  If it’s under development (running from the source
          tree) then the default is ‘off’.  Note that the
          ‘importlib_bootstrap’ and ‘importlib_bootstrap_external’
          frozen modules are always used, even if this flag is set to
          ‘off’.  See also *note PYTHON_FROZEN_MODULES: 4ae.

          Added in version 3.11.

        * ‘-X perf’ enables support for the Linux ‘perf’ profiler.  When
          this option is provided, the ‘perf’ profiler will be able to
          report Python calls.  This option is only available on some
          platforms and will do nothing if is not supported on the
          current system.  The default value is «off».  See also *note
          PYTHONPERFSUPPORT: 69a. and *note Python support for the Linux
          perf profiler: 4af.

          Added in version 3.12.

        * ‘-X perf_jit’ enables support for the Linux ‘perf’ profiler
          with DWARF support.  When this option is provided, the ‘perf’
          profiler will be able to report Python calls using DWARF
          information.  This option is only available on some platforms
          and will do nothing if is not supported on the current system.
          The default value is «off».  See also *note
          PYTHON_PERF_JIT_SUPPORT: 4b0. and *note Python support for the
          Linux perf profiler: 4af.

          Added in version 3.13.

        * ‘-X disable_remote_debug’ disables the remote debugging
          support as described in PEP 768(6).  This includes both the
          functionality to schedule code for execution in another
          process and the functionality to receive code for execution in
          the current process.

          This option is only available on some platforms and will do
          nothing if is not supported on the current system.  See also
          *note PYTHON_DISABLE_REMOTE_DEBUG: 16e. and PEP 768(7).

          Added in version 3.14.

        * ‘-X cpu_count=N’ overrides *note os.cpu_count(): 4dc, *note
          os.process_cpu_count(): 4db, and *note
          multiprocessing.cpu_count(): 1171.  'n' must be greater than
          or equal to 1.  This option may be useful for users who need
          to limit CPU resources of a container system.  See also *note
          PYTHON_CPU_COUNT: 51f.  If 'n' is ‘default’, nothing is
          overridden.

          Added in version 3.13.

        * ‘-X presite=PACKAGE.MODULE’ specifies a module that should be
          imported before the *note site: cc. module is executed and
          before the *note __main__: 1. module exists.  Therefore, the
          imported module isn’t *note __main__: 1.  This can be used to
          execute code early during Python initialization.  Python needs
          to be *note built in debug mode: 50a. for this option to
          exist.  See also *note PYTHON_PRESITE: 2118.

          Added in version 3.13.

        * ‘-X gil=0,1’ forces the GIL to be disabled or enabled,
          respectively.  Setting to ‘0’ is only available in builds
          configured with *note -disable-gil: 49a.  See also *note
          PYTHON_GIL: 49b. and *note Free-threaded CPython: 46d.

          Added in version 3.13.

        * ‘-X thread_inherit_context=0,1’ causes *note Thread: 176. to,
          by default, use a copy of context of the caller of
          ‘Thread.start()’ when starting.  Otherwise, threads will start
          with an empty context.  If unset, the value of this option
          defaults to ‘1’ on free-threaded builds and to ‘0’ otherwise.
          See also *note PYTHON_THREAD_INHERIT_CONTEXT: 1850.

          Added in version 3.14.

        * ‘-X context_aware_warnings=0,1’ causes the *note
          warnings.catch_warnings: 179. context manager to use a *note
          ContextVar: 185d. to store warnings filter state.  If unset,
          the value of this option defaults to ‘1’ on free-threaded
          builds and to ‘0’ otherwise.  See also *note
          PYTHON_CONTEXT_AWARE_WARNINGS: 1843.

          Added in version 3.14.

        * ‘-X tlbc=0,1’ enables (1, the default) or disables (0)
          thread-local bytecode in builds configured with *note
          -disable-gil: 49a.  When disabled, this also disables the
          specializing interpreter.  See also *note PYTHON_TLBC: 2119.

          Added in version 3.14.

     It also allows passing arbitrary values and retrieving them through
     the *note sys._xoptions: 211a. dictionary.

     Added in version 3.2.

     Cambiato nella versione 3.9: Removed the ‘-X showalloccount’
     option.

     Cambiato nella versione 3.10: Removed the ‘-X oldparser’ option.

Removed in version 3.14: ‘-J’ is no longer reserved for use by
Jython(8), and now has no special meaning.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0488/

   (2) https://peps.python.org/pep-0488/

   (3) https://peps.python.org/pep-0488/

   (4) https://peps.python.org/pep-0488/

   (5) https://peps.python.org/pep-0370/

   (6) https://peps.python.org/pep-0768/

   (7) https://peps.python.org/pep-0768/

   (8) https://www.jython.org/


File: python.info,  Node: Controlling color,  Prev: Miscellaneous options,  Up: Command line

3.1.1.4 Controlling color
.........................

The Python interpreter is configured by default to use colors to
highlight output in certain situations such as when displaying
tracebacks.  This behavior can be controlled by setting different
environment variables.

Setting the environment variable ‘TERM’ to ‘dumb’ will disable color.

If the FORCE_COLOR(1) environment variable is set, then color will be
enabled regardless of the value of TERM. This is useful on CI systems
which aren’t terminals but can still display ANSI escape sequences.

If the NO_COLOR(2) environment variable is set, Python will disable all
color in the output.  This takes precedence over ‘FORCE_COLOR’.

All these environment variables are used also by other tools to control
color output.  To control the color output only in the Python
interpreter, the *note PYTHON_COLORS: 476. environment variable can be
used.  This variable takes precedence over ‘NO_COLOR’, which in turn
takes precedence over ‘FORCE_COLOR’.

   ---------- Footnotes ----------

   (1) https://force-color.org/

   (2) https://no-color.org/


File: python.info,  Node: Environment variables,  Prev: Command line,  Up: Command line and environment<2>

3.1.2 Environment variables
---------------------------

These environment variables influence Python’s behavior, they are
processed before the command-line switches other than -E or -I. It is
customary that command-line switches override environmental variables
where there is a conflict.

 -- Variabile d'ambiente: PYTHONHOME

     Change the location of the standard Python libraries.  By default,
     the libraries are searched in ‘`prefix'/lib/python`version'’ and
     ‘`exec_prefix'/lib/python`version'’, where ‘`prefix'’ and
     ‘`exec_prefix'’ are installation-dependent directories, both
     defaulting to ‘/usr/local’.

     When *note PYTHONHOME: 3f0. is set to a single directory, its value
     replaces both ‘`prefix'’ and ‘`exec_prefix'’.  To specify different
     values for these, set *note PYTHONHOME: 3f0. to
     ‘`prefix':`exec_prefix'’.

 -- Variabile d'ambiente: PYTHONPATH

     Augment the default search path for module files.  The format is
     the same as the shell’s ‘PATH’: one or more directory pathnames
     separated by *note os.pathsep: 211d. (e.g.  colons on Unix or
     semicolons on Windows).  Non-existent directories are silently
     ignored.

     In addition to normal directories, individual *note PYTHONPATH:
     121f. entries may refer to zipfiles containing pure Python modules
     (in either source or compiled form).  Extension modules cannot be
     imported from zipfiles.

     The default search path is installation dependent, but generally
     begins with ‘`prefix'/lib/python`version'’ (see *note PYTHONHOME:
     3f0. above).  It is 'always' appended to *note PYTHONPATH: 121f.

     An additional directory will be inserted in the search path in
     front of *note PYTHONPATH: 121f. as described above under *note
     Interface options: 2104.  The search path can be manipulated from
     within a Python program as the variable *note sys.path: 3e4.

 -- Variabile d'ambiente: PYTHONSAFEPATH

     If this is set to a non-empty string, don’t prepend a potentially
     unsafe path to *note sys.path: 3e4.: see the *note -P: 7c2. option
     for details.

     Added in version 3.11.

 -- Variabile d'ambiente: PYTHONPLATLIBDIR

     If this is set to a non-empty string, it overrides the *note
     sys.platlibdir: b34. value.

     Added in version 3.9.

 -- Variabile d'ambiente: PYTHONSTARTUP

     If this is the name of a readable file, the Python commands in that
     file are executed before the first prompt is displayed in
     interactive mode.  The file is executed in the same namespace where
     interactive commands are executed so that objects defined or
     imported in it can be used without qualification in the interactive
     session.  You can also change the prompts *note sys.ps1: 211e. and
     *note sys.ps2: 211f. and the hook *note sys.__interactivehook__:
     11ca. in this file.

     Raises an *note auditing event: 1c56. ‘cpython.run_startup’ with
     the filename as the argument when called on startup.

 -- Variabile d'ambiente: PYTHONOPTIMIZE

     If this is set to a non-empty string it is equivalent to specifying
     the *note -O: 18c. option.  If set to an integer, it is equivalent
     to specifying *note -O: 18c. multiple times.

 -- Variabile d'ambiente: PYTHONBREAKPOINT

     If this is set, it names a callable using dotted-path notation.
     The module containing the callable will be imported and then the
     callable will be run by the default implementation of *note
     sys.breakpointhook(): cd3. which itself is called by built-in *note
     breakpoint(): 271.  If not set, or set to the empty string, it is
     equivalent to the value «pdb.set_trace».  Setting this to the
     string «0» causes the default implementation of *note
     sys.breakpointhook(): cd3. to do nothing but return immediately.

     Added in version 3.7.

 -- Variabile d'ambiente: PYTHONDEBUG

     If this is set to a non-empty string it is equivalent to specifying
     the *note -d: 210c. option.  If set to an integer, it is equivalent
     to specifying *note -d: 210c. multiple times.

     This environment variable requires a *note debug build of Python:
     50a, otherwise it’s ignored.

 -- Variabile d'ambiente: PYTHONINSPECT

     If this is set to a non-empty string it is equivalent to specifying
     the *note -i: 16e2. option.

     This variable can also be modified by Python code using *note
     os.environ: 259. to force inspect mode on program termination.

     Raises an *note auditing event: 1c56. ‘cpython.run_stdin’ with no
     arguments.

     Cambiato nella versione 3.12.5: (also 3.11.10, 3.10.15, 3.9.20, and
     3.8.20) Emits audit events.

     Cambiato nella versione 3.13: Uses PyREPL if possible, in which
     case *note PYTHONSTARTUP: 1b8. is also executed.  Emits audit
     events.

 -- Variabile d'ambiente: PYTHONUNBUFFERED

     If this is set to a non-empty string it is equivalent to specifying
     the *note -u: 1d75. option.

 -- Variabile d'ambiente: PYTHONVERBOSE

     If this is set to a non-empty string it is equivalent to specifying
     the *note -v: 162c. option.  If set to an integer, it is equivalent
     to specifying *note -v: 162c. multiple times.

 -- Variabile d'ambiente: PYTHONCASEOK

     If this is set, Python ignores case in *note import: 7f9.
     statements.  This only works on Windows and macOS.

 -- Variabile d'ambiente: PYTHONDONTWRITEBYTECODE

     If this is set to a non-empty string, Python won’t try to write
     ‘.pyc’ files on the import of source modules.  This is equivalent
     to specifying the *note -B: 15d4. option.

 -- Variabile d'ambiente: PYTHONPYCACHEPREFIX

     If this is set, Python will write ‘.pyc’ files in a mirror
     directory tree at this path, instead of in ‘__pycache__’
     directories within the source tree.  This is equivalent to
     specifying the *note -X: 16f. ‘pycache_prefix=PATH’ option.

     Added in version 3.8.

 -- Variabile d'ambiente: PYTHONHASHSEED

     If this variable is not set or set to ‘random’, a random value is
     used to seed the hashes of str and bytes objects.

     If *note PYTHONHASHSEED: 127f. is set to an integer value, it is
     used as a fixed seed for generating the hash() of the types covered
     by the hash randomization.

     Its purpose is to allow repeatable hashing, such as for selftests
     for the interpreter itself, or to allow a cluster of python
     processes to share hash values.

     The integer must be a decimal number in the range [0,4294967295].
     Specifying the value 0 will disable hash randomization.

     Added in version 3.2.3.

 -- Variabile d'ambiente: PYTHONINTMAXSTRDIGITS

     If this variable is set to an integer, it is used to configure the
     interpreter’s global *note integer string conversion length
     limitation: 80c.

     Added in version 3.11.

 -- Variabile d'ambiente: PYTHONIOENCODING

     If this is set before running the interpreter, it overrides the
     encoding used for stdin/stdout/stderr, in the syntax
     ‘encodingname:errorhandler’.  Both the ‘encodingname’ and the
     ‘:errorhandler’ parts are optional and have the same meaning as in
     *note str.encode(): ad4.

     For stderr, the ‘:errorhandler’ part is ignored; the handler will
     always be ‘'backslashreplace'’.

     Cambiato nella versione 3.4: The ‘encodingname’ part is now
     optional.

     Cambiato nella versione 3.6: On Windows, the encoding specified by
     this variable is ignored for interactive console buffers unless
     *note PYTHONLEGACYWINDOWSSTDIO: e57. is also specified.  Files and
     pipes redirected through the standard streams are not affected.

 -- Variabile d'ambiente: PYTHONNOUSERSITE

     If this is set, Python won’t add the *note user site-packages
     directory: 210f. to *note sys.path: 3e4.

     Vedi anche
     ..........

     PEP 370(1) – Per user site-packages directory

 -- Variabile d'ambiente: PYTHONUSERBASE

     Defines the *note user base directory: 1524, which is used to
     compute the path of the *note user site-packages directory: 210f.
     and *note installation paths: 2120. for ‘python -m pip install
     --user’.

     Vedi anche
     ..........

     PEP 370(2) – Per user site-packages directory

 -- Variabile d'ambiente: PYTHONEXECUTABLE

     If this environment variable is set, ‘sys.argv[0]’ will be set to
     its value instead of the value got through the C runtime.  Only
     works on macOS.

 -- Variabile d'ambiente: PYTHONWARNINGS

     This is equivalent to the *note -W: ac7. option.  If set to a comma
     separated string, it is equivalent to specifying *note -W: ac7.
     multiple times, with filters later in the list taking precedence
     over those earlier in the list.

     The simplest settings apply a particular action unconditionally to
     all warnings emitted by a process (even those that are otherwise
     ignored by default):

          PYTHONWARNINGS=default  # Warn once per call location
          PYTHONWARNINGS=error    # Convert to exceptions
          PYTHONWARNINGS=always   # Warn every time
          PYTHONWARNINGS=all      # Same as PYTHONWARNINGS=always
          PYTHONWARNINGS=module   # Warn once per calling module
          PYTHONWARNINGS=once     # Warn once per Python process
          PYTHONWARNINGS=ignore   # Never warn

     See *note The Warnings Filter: 1b1. and *note Describing Warning
     Filters: 2113. for more details.

 -- Variabile d'ambiente: PYTHONFAULTHANDLER

     If this environment variable is set to a non-empty string, *note
     faulthandler.enable(): 20f. is called at startup: install a handler
     for *note SIGSEGV: 1282, *note SIGFPE: 1283, *note SIGABRT: 1284,
     *note SIGBUS: 1285. and *note SIGILL: 1286. signals to dump the
     Python traceback.  This is equivalent to *note -X: 16f.
     ‘faulthandler’ option.

     Added in version 3.3.

 -- Variabile d'ambiente: PYTHONTRACEMALLOC

     If this environment variable is set to a non-empty string, start
     tracing Python memory allocations using the *note tracemalloc: 105.
     module.  The value of the variable is the maximum number of frames
     stored in a traceback of a trace.  For example,
     ‘PYTHONTRACEMALLOC=1’ stores only the most recent frame.  See the
     *note tracemalloc.start(): 2115. function for more information.
     This is equivalent to setting the *note -X: 16f. ‘tracemalloc’
     option.

     Added in version 3.4.

 -- Variabile d'ambiente: PYTHONPROFILEIMPORTTIME

     If this environment variable is set to ‘1’, Python will show how
     long each import takes.  If set to ‘2’, Python will include output
     for imported modules that have already been loaded.  This is
     equivalent to setting the *note -X: 16f. ‘importtime’ option.

     Added in version 3.7.

     Cambiato nella versione 3.14: Added ‘PYTHONPROFILEIMPORTTIME=2’ to
     also trace imports of loaded modules.

 -- Variabile d'ambiente: PYTHONASYNCIODEBUG

     If this environment variable is set to a non-empty string, enable
     the *note debug mode: 2123. of the *note asyncio: b. module.

     Added in version 3.4.

 -- Variabile d'ambiente: PYTHONMALLOC

     Set the Python memory allocators and/or install debug hooks.

     Set the family of memory allocators used by Python:

        * ‘default’: use the *note default memory allocators: 2124.

        * ‘malloc’: use the ‘malloc()’ function of the C library for all
          domains (*note PYMEM_DOMAIN_RAW: 2125, *note PYMEM_DOMAIN_MEM:
          e65, *note PYMEM_DOMAIN_OBJ: e63.).

        * ‘pymalloc’: use the *note pymalloc allocator: f0d. for *note
          PYMEM_DOMAIN_MEM: e65. and *note PYMEM_DOMAIN_OBJ: e63.
          domains and use the ‘malloc()’ function for the *note
          PYMEM_DOMAIN_RAW: 2125. domain.

        * ‘mimalloc’: use the *note mimalloc allocator: 2126. for *note
          PYMEM_DOMAIN_MEM: e65. and *note PYMEM_DOMAIN_OBJ: e63.
          domains and use the ‘malloc()’ function for the *note
          PYMEM_DOMAIN_RAW: 2125. domain.

     Install *note debug hooks: 2127.:

        * ‘debug’: install debug hooks on top of the *note default
          memory allocators: 2124.

        * ‘malloc_debug’: same as ‘malloc’ but also install debug hooks.

        * ‘pymalloc_debug’: same as ‘pymalloc’ but also install debug
          hooks.

        * ‘mimalloc_debug’: same as ‘mimalloc’ but also install debug
          hooks.

     Added in version 3.6.

     Cambiato nella versione 3.7: Added the ‘"default"’ allocator.

 -- Variabile d'ambiente: PYTHONMALLOCSTATS

     If set to a non-empty string, Python will print statistics of the
     *note pymalloc memory allocator: f0d. every time a new pymalloc
     object arena is created, and on shutdown.

     This variable is ignored if the *note PYTHONMALLOC: e60.
     environment variable is used to force the ‘malloc()’ allocator of
     the C library, or if Python is configured without ‘pymalloc’
     support.

     Cambiato nella versione 3.6: This variable can now also be used on
     Python compiled in release mode.  It now has no effect if set to an
     empty string.

 -- Variabile d'ambiente: PYTHONLEGACYWINDOWSFSENCODING

     If set to a non-empty string, the default *note filesystem encoding
     and error handler: 75e. mode will revert to their pre-3.6 values of
     “mbcs” and “replace”, respectively.  Otherwise, the new defaults
     “utf-8” and “surrogatepass” are used.

     This may also be enabled at runtime with *note
     sys._enablelegacywindowsfsencoding(): 33e.

     *note Availability: 2128.: Windows.

     Added in version 3.6: See PEP 529(3) for more details.

 -- Variabile d'ambiente: PYTHONLEGACYWINDOWSSTDIO

     If set to a non-empty string, does not use the new console reader
     and writer.  This means that Unicode characters will be encoded
     according to the active console code page, rather than using utf-8.

     This variable is ignored if the standard streams are redirected (to
     files or pipes) rather than referring to console buffers.

     *note Availability: 2128.: Windows.

     Added in version 3.6.

 -- Variabile d'ambiente: PYTHONCOERCECLOCALE

     If set to the value ‘0’, causes the main Python command line
     application to skip coercing the legacy ASCII-based C and POSIX
     locales to a more capable UTF-8 based alternative.

     If this variable is 'not' set (or is set to a value other than
     ‘0’), the ‘LC_ALL’ locale override environment variable is also not
     set, and the current locale reported for the ‘LC_CTYPE’ category is
     either the default ‘C’ locale, or else the explicitly ASCII-based
     ‘POSIX’ locale, then the Python CLI will attempt to configure the
     following locales for the ‘LC_CTYPE’ category in the order listed
     before loading the interpreter runtime:

        * ‘C.UTF-8’

        * ‘C.utf8’

        * ‘UTF-8’

     If setting one of these locale categories succeeds, then the
     ‘LC_CTYPE’ environment variable will also be set accordingly in the
     current process environment before the Python runtime is
     initialized.  This ensures that in addition to being seen by both
     the interpreter itself and other locale-aware components running in
     the same process (such as the GNU ‘readline’ library), the updated
     setting is also seen in subprocesses (regardless of whether or not
     those processes are running a Python interpreter), as well as in
     operations that query the environment rather than the current C
     locale (such as Python’s own *note locale.getdefaultlocale():
     326.).

     Configuring one of these locales (either explicitly or via the
     above implicit locale coercion) automatically enables the
     ‘surrogateescape’ *note error handler: 1b57. for *note sys.stdin:
     760. and *note sys.stdout: ccf. (*note sys.stderr: b35. continues
     to use ‘backslashreplace’ as it does in any other locale).  This
     stream handling behavior can be overridden using *note
     PYTHONIOENCODING: 120c. as usual.

     For debugging purposes, setting ‘PYTHONCOERCECLOCALE=warn’ will
     cause Python to emit warning messages on ‘stderr’ if either the
     locale coercion activates, or else if a locale that 'would' have
     triggered coercion is still active when the Python runtime is
     initialized.

     Also note that even when locale coercion is disabled, or when it
     fails to find a suitable target locale, *note PYTHONUTF8: cd1. will
     still activate by default in legacy ASCII-based locales.  Both
     features must be disabled in order to force the interpreter to use
     ‘ASCII’ instead of ‘UTF-8’ for system interfaces.

     *note Availability: 2128.: Unix.

     Added in version 3.7: See PEP 538(4) for more details.

 -- Variabile d'ambiente: PYTHONDEVMODE

     If this environment variable is set to a non-empty string, enable
     *note Python Development Mode: 509, introducing additional runtime
     checks that are too expensive to be enabled by default.  This is
     equivalent to setting the *note -X: 16f. ‘dev’ option.

     Added in version 3.7.

 -- Variabile d'ambiente: PYTHONUTF8

     If set to ‘1’, enable the *note Python UTF-8 Mode: 867.

     If set to ‘0’, disable the *note Python UTF-8 Mode: 867.

     Setting any other non-empty string causes an error during
     interpreter initialisation.

     Added in version 3.7.

 -- Variabile d'ambiente: PYTHONWARNDEFAULTENCODING

     If this environment variable is set to a non-empty string, issue a
     *note EncodingWarning: 2117. when the locale-specific default
     encoding is used.

     See *note Opt-in EncodingWarning: 2129. for details.

     Added in version 3.10.

 -- Variabile d'ambiente: PYTHONNODEBUGRANGES

     If this variable is set, it disables the inclusion of the tables
     mapping extra location information (end line, start column offset
     and end column offset) to every instruction in code objects.  This
     is useful when smaller code objects and pyc files are desired as
     well as suppressing the extra visual location indicators when the
     interpreter displays tracebacks.

     Added in version 3.11.

 -- Variabile d'ambiente: PYTHONPERFSUPPORT

     If this variable is set to a nonzero value, it enables support for
     the Linux ‘perf’ profiler so Python calls can be detected by it.

     If set to ‘0’, disable Linux ‘perf’ profiler support.

     See also the *note -X perf: 16f. command-line option and *note
     Python support for the Linux perf profiler: 4af.

     Added in version 3.12.

 -- Variabile d'ambiente: PYTHON_PERF_JIT_SUPPORT

     If this variable is set to a nonzero value, it enables support for
     the Linux ‘perf’ profiler so Python calls can be detected by it
     using DWARF information.

     If set to ‘0’, disable Linux ‘perf’ profiler support.

     See also the *note -X perf_jit: 16f. command-line option and *note
     Python support for the Linux perf profiler: 4af.

     Added in version 3.13.

 -- Variabile d'ambiente: PYTHON_DISABLE_REMOTE_DEBUG

     If this variable is set to a non-empty string, it disables the
     remote debugging feature described in PEP 768(5).  This includes
     both the functionality to schedule code for execution in another
     process and the functionality to receive code for execution in the
     current process.

     See also the *note -X disable_remote_debug: 16f. command-line
     option.

     Added in version 3.14.

 -- Variabile d'ambiente: PYTHON_CPU_COUNT

     If this variable is set to a positive integer, it overrides the
     return values of *note os.cpu_count(): 4dc. and *note
     os.process_cpu_count(): 4db.

     See also the *note -X cpu_count: 16f. command-line option.

     Added in version 3.13.

 -- Variabile d'ambiente: PYTHON_FROZEN_MODULES

     If this variable is set to ‘on’ or ‘off’, it determines whether or
     not frozen modules are ignored by the import machinery.  A value of
     ‘on’ means they get imported and ‘off’ means they are ignored.  The
     default is ‘on’ for non-debug builds (the normal case) and ‘off’
     for debug builds.  Note that the ‘importlib_bootstrap’ and
     ‘importlib_bootstrap_external’ frozen modules are always used, even
     if this flag is set to ‘off’.

     See also the *note -X frozen_modules: 16f. command-line option.

     Added in version 3.13.

 -- Variabile d'ambiente: PYTHON_COLORS

     If this variable is set to ‘1’, the interpreter will colorize
     various kinds of output.  Setting it to ‘0’ deactivates this
     behavior.  See also *note Controlling color: 1b7.

     Added in version 3.13.

 -- Variabile d'ambiente: PYTHON_BASIC_REPL

     If this variable is set to any value, the interpreter will not
     attempt to load the Python-based *note REPL: 492. that requires
     *note readline: bf, and will instead use the traditional
     parser-based *note REPL: 492.

     Added in version 3.13.

 -- Variabile d'ambiente: PYTHON_HISTORY

     This environment variable can be used to set the location of a
     ‘.python_history’ file (by default, it is ‘.python_history’ in the
     user’s home directory).

     Added in version 3.13.

 -- Variabile d'ambiente: PYTHON_GIL

     If this variable is set to ‘1’, the global interpreter lock (GIL)
     will be forced on.  Setting it to ‘0’ forces the GIL off (needs
     Python configured with the *note -disable-gil: 49a. build option).

     See also the *note -X gil: 16f. command-line option, which takes
     precedence over this variable, and *note Free-threaded CPython:
     46d.

     Added in version 3.13.

 -- Variabile d'ambiente: PYTHON_THREAD_INHERIT_CONTEXT

     If this variable is set to ‘1’ then *note Thread: 176. will, by
     default, use a copy of context of the caller of ‘Thread.start()’
     when starting.  Otherwise, new threads will start with an empty
     context.  If unset, this variable defaults to ‘1’ on free-threaded
     builds and to ‘0’ otherwise.  See also *note -X
     thread_inherit_context: 16f.

     Added in version 3.14.

 -- Variabile d'ambiente: PYTHON_CONTEXT_AWARE_WARNINGS

     If set to ‘1’ then the *note warnings.catch_warnings: 179. context
     manager will use a *note ContextVar: 185d. to store warnings filter
     state.  If unset, this variable defaults to ‘1’ on free-threaded
     builds and to ‘0’ otherwise.  See *note -X context_aware_warnings:
     16f.

     Added in version 3.14.

 -- Variabile d'ambiente: PYTHON_JIT

     On builds where experimental just-in-time compilation is available,
     this variable can force the JIT to be disabled (‘0’) or enabled
     (‘1’) at interpreter startup.

     Added in version 3.13.

 -- Variabile d'ambiente: PYTHON_TLBC

     If set to ‘1’ enables thread-local bytecode.  If set to ‘0’
     thread-local bytecode and the specializing interpreter are
     disabled.  Only applies to builds configured with *note
     -disable-gil: 49a.

     See also the *note -X tlbc: 16f. command-line option.

     Added in version 3.14.

* Menu:

* Debug-mode variables::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0370/

   (2) https://peps.python.org/pep-0370/

   (3) https://peps.python.org/pep-0529/

   (4) https://peps.python.org/pep-0538/

   (5) https://peps.python.org/pep-0768/


File: python.info,  Node: Debug-mode variables,  Up: Environment variables

3.1.2.1 Debug-mode variables
............................

 -- Variabile d'ambiente: PYTHONDUMPREFS

     If set, Python will dump objects and reference counts still alive
     after shutting down the interpreter.

     Needs Python configured with the *note -with-trace-refs: 636. build
     option.

 -- Variabile d'ambiente: PYTHONDUMPREFSFILE

     If set, Python will dump objects and reference counts still alive
     after shutting down the interpreter into a file under the path
     given as the value to this environment variable.

     Needs Python configured with the *note -with-trace-refs: 636. build
     option.

     Added in version 3.11.

 -- Variabile d'ambiente: PYTHON_PRESITE

     If this variable is set to a module, that module will be imported
     early in the interpreter lifecycle, before the *note site: cc.
     module is executed, and before the *note __main__: 1. module is
     created.  Therefore, the imported module is not treated as *note
     __main__: 1.

     This can be used to execute code early during Python
     initialization.

     To import a submodule, use ‘package.module’ as the value, like in
     an import statement.

     See also the *note -X presite: 16f. command-line option, which
     takes precedence over this variable.

     Needs Python configured with the *note -with-pydebug: 666. build
     option.

     Added in version 3.13.


File: python.info,  Node: Using Python on Unix platforms,  Next: Configure Python,  Prev: Command line and environment<2>,  Up: Python Setup and Usage

3.2 Using Python on Unix platforms
==================================

* Menu:

* Getting and installing the latest version of Python::
* Building Python::
* Python-related paths and files::
* Miscellaneous::
* Custom OpenSSL::


File: python.info,  Node: Getting and installing the latest version of Python,  Next: Building Python,  Up: Using Python on Unix platforms

3.2.1 Getting and installing the latest version of Python
---------------------------------------------------------

* Menu:

* On Linux::
* On FreeBSD and OpenBSD::


File: python.info,  Node: On Linux,  Next: On FreeBSD and OpenBSD,  Up: Getting and installing the latest version of Python

3.2.1.1 On Linux
................

Python comes preinstalled on most Linux distributions, and is available
as a package on all others.  However there are certain features you
might want to use that are not available on your distro’s package.  You
can compile the latest version of Python from source.

In the event that the latest version of Python doesn’t come preinstalled
and isn’t in the repositories as well, you can make packages for your
own distro.  Have a look at the following links:

Vedi anche
..........

‘https://www.debian.org/doc/manuals/maint-guide/first.en.html’

     for Debian users

‘https://en.opensuse.org/Portal:Packaging’

     for OpenSuse users

‘https://docs.fedoraproject.org/en-US/package-maintainers/Packaging_Tutorial_GNU_Hello/’

     for Fedora users

‘https://slackbook.org/html/package-management-making-packages.html’

     for Slackware users

* Menu:

* Installing IDLE::


File: python.info,  Node: Installing IDLE,  Up: On Linux

3.2.1.2 Installing IDLE
.......................

In some cases, IDLE might not be included in your Python installation.

   * For Debian and Ubuntu users:

          sudo apt update
          sudo apt install idle

   * For Fedora, RHEL, and CentOS users:

          sudo dnf install python3-idle

   * For SUSE and OpenSUSE users:

          sudo zypper install python3-idle

   * For Alpine Linux users:

          sudo apk add python3-idle


File: python.info,  Node: On FreeBSD and OpenBSD,  Prev: On Linux,  Up: Getting and installing the latest version of Python

3.2.1.3 On FreeBSD and OpenBSD
..............................

   * FreeBSD users, to add the package use:

          pkg install python3

   * OpenBSD users, to add the package use:

          pkg_add -r python

          pkg_add ftp://ftp.openbsd.org/pub/OpenBSD/4.2/packages/<insert your architecture here>/python-<version>.tgz

     For example i386 users get the 2.5.1 version of Python using:

          pkg_add ftp://ftp.openbsd.org/pub/OpenBSD/4.2/packages/i386/python-2.5.1p2.tgz


File: python.info,  Node: Building Python,  Next: Python-related paths and files,  Prev: Getting and installing the latest version of Python,  Up: Using Python on Unix platforms

3.2.2 Building Python
---------------------

Vedi anche
..........

If you want to contribute to CPython, refer to the devguide(1), which
includes build instructions and other tips on setting up environment.

If you want to compile CPython yourself, first thing you should do is
get the source(2).  You can download either the latest release’s source
or grab a fresh clone(3).  You will also need to install the *note build
requirements: 2135.

The build process consists of the usual commands:

     ./configure
     make
     make install

*note Configuration options: 2136. and caveats for specific Unix
platforms are extensively documented in the README.rst(4) file in the
root of the Python source tree.

     Avvertimento: ‘make install’ can overwrite or masquerade the
     ‘python3’ binary.  ‘make altinstall’ is therefore recommended
     instead of ‘make install’ since it only installs
     ‘`exec_prefix'/bin/python`version'’.

   ---------- Footnotes ----------

   (1) https://devguide.python.org/getting-started/setup-building/

   (2) https://www.python.org/downloads/source/

   (3) https://devguide.python.org/setup/#get-the-source-code

   (4) https://github.com/python/cpython/tree/3.14/README.rst


File: python.info,  Node: Python-related paths and files,  Next: Miscellaneous,  Prev: Building Python,  Up: Using Python on Unix platforms

3.2.3 Python-related paths and files
------------------------------------

These are subject to difference depending on local installation
conventions; *note prefix: 2138. and *note exec_prefix: 2139. are
installation-dependent and should be interpreted as for GNU software;
they may be the same.

For example, on most Linux systems, the default for both is ‘/usr’.

File/directory                                      Meaning
                                                    
---------------------------------------------------------------------------------------------------
                                                    
‘`exec_prefix'/bin/python3’                         Recommended location of the interpreter.
                                                    
                                                    
‘`prefix'/lib/python`version'’,                     Recommended locations of the directories
‘`exec_prefix'/lib/python`version'’                 containing the standard modules.
                                                    
                                                    
‘`prefix'/include/python`version'’,                 Recommended locations of the directories
‘`exec_prefix'/include/python`version'’             containing the include files needed for
                                                    developing Python extensions and embedding
                                                    the interpreter.
                                                    


File: python.info,  Node: Miscellaneous,  Next: Custom OpenSSL,  Prev: Python-related paths and files,  Up: Using Python on Unix platforms

3.2.4 Miscellaneous
-------------------

To easily use Python scripts on Unix, you need to make them executable,
e.g.  with

     $ chmod +x script

and put an appropriate Shebang line at the top of the script.  A good
choice is usually

     #!/usr/bin/env python3

which searches for the Python interpreter in the whole ‘PATH’.  However,
some Unices may not have the ‘env’ command, so you may need to hardcode
‘/usr/bin/python3’ as the interpreter path.

To use shell commands in your Python scripts, look at the *note
subprocess: dc. module.


File: python.info,  Node: Custom OpenSSL,  Prev: Miscellaneous,  Up: Using Python on Unix platforms

3.2.5 Custom OpenSSL
--------------------

  1. To use your vendor’s OpenSSL configuration and system trust store,
     locate the directory with ‘openssl.cnf’ file or symlink in ‘/etc’.
     On most distribution the file is either in ‘/etc/ssl’ or
     ‘/etc/pki/tls’.  The directory should also contain a ‘cert.pem’
     file and/or a ‘certs’ directory.

          $ find /etc/ -name openssl.cnf -printf "%h\n"
          /etc/ssl

  2. Download, build, and install OpenSSL. Make sure you use
     ‘install_sw’ and not ‘install’.  The ‘install_sw’ target does not
     override ‘openssl.cnf’.

          $ curl -O https://www.openssl.org/source/openssl-VERSION.tar.gz
          $ tar xzf openssl-VERSION
          $ pushd openssl-VERSION
          $ ./config \
              --prefix=/usr/local/custom-openssl \
              --libdir=lib \
              --openssldir=/etc/ssl
          $ make -j1 depend
          $ make -j8
          $ make install_sw
          $ popd

  3. Build Python with custom OpenSSL (see the configure
     ‘--with-openssl’ and ‘--with-openssl-rpath’ options)

          $ pushd python-3.x.x
          $ ./configure -C \
              --with-openssl=/usr/local/custom-openssl \
              --with-openssl-rpath=auto \
              --prefix=/usr/local/python-3.x.x
          $ make -j8
          $ make altinstall

     Nota: Patch releases of OpenSSL have a backwards compatible ABI.
     You don’t need to recompile Python to update OpenSSL. It’s
     sufficient to replace the custom OpenSSL installation with a newer
     version.


File: python.info,  Node: Configure Python,  Next: Using Python on Windows,  Prev: Using Python on Unix platforms,  Up: Python Setup and Usage

3.3 Configure Python
====================

* Menu:

* Build Requirements::
* Generated files::
* Configure Options::
* Python Build System::
* Compiler and linker flags::


File: python.info,  Node: Build Requirements,  Next: Generated files,  Up: Configure Python

3.3.1 Build Requirements
------------------------

To build CPython, you will need:

   * A C11(1) compiler.  Optional C11 features(2) are not required.

   * On Windows, Microsoft Visual Studio 2017 or later is required.

   * Support for IEEE 754(3) floating-point numbers and floating-point
     Not-a-Number (NaN)(4).

   * Support for threads.

Cambiato nella versione 3.5: On Windows, Visual Studio 2015 or later is
now required.

Cambiato nella versione 3.6: Selected C99 features, like ‘<stdint.h>’
and ‘static inline’ functions, are now required.

Cambiato nella versione 3.7: Thread support is now required.

Cambiato nella versione 3.11: C11 compiler, IEEE 754 and NaN support are
now required.  On Windows, Visual Studio 2017 or later is required.

See also PEP 7(5) «Style Guide for C Code» and PEP 11(6) «CPython
platform support».

* Menu:

* Requirements for optional modules::

   ---------- Footnotes ----------

   (1) https://en.cppreference.com/w/c/11

   (2) 
https://en.wikipedia.org/wiki/C11_(C_standard_revision)#Optional_features

   (3) https://en.wikipedia.org/wiki/IEEE_754

   (4) https://en.wikipedia.org/wiki/NaN#Floating_point

   (5) https://peps.python.org/pep-0007/

   (6) https://peps.python.org/pep-0011/


File: python.info,  Node: Requirements for optional modules,  Up: Build Requirements

3.3.1.1 Requirements for optional modules
.........................................

Some *note optional modules: 2143. of the standard library require
third-party libraries installed for development (for example, header
files must be available).

Missing requirements are reported in the ‘configure’ output.  Modules
that are missing due to missing dependencies are listed near the end of
the ‘make’ output, sometimes using an internal name, for example,
‘_ctypes’ for *note ctypes: 2e. module.

If you distribute a CPython interpreter without optional modules, it’s
best practice to advise users, who generally expect that standard
library modules are available.

Dependencies to build optional modules are:

Dependency                            Minimum version                       Python module
                                                                            
------------------------------------------------------------------------------------------------------------------
                                                                            
libbz2(1)                                                                   *note bz2: 14.
                                                                            
                                                                            
libffi(2)                             3.3.0 recommended                     *note ctypes: 2e.
                                                                            
                                                                            
liblzma(3)                                                                  *note lzma: 8e.
                                                                            
                                                                            
libmpdec(4)                           2.5.0                                 *note decimal: 3a. (5)
                                                                            
                                                                            
libreadline(6) or libedit(7) (8)                                            *note readline: bf.
                                                                            
                                                                            
libuuid(9)                                                                  ‘_uuid’ (10)
                                                                            
                                                                            
ncurses(11) (12)                                                            *note curses: 2f.
                                                                            
                                                                            
OpenSSL(13)                                3.0.18 recommended               *note ssl: d5, *note hashlib: 6c.
                                           (1.1.1 minimum)                  (14)
                                                                            
                                                                            
SQLite(15)                            3.15.2                                *note sqlite3: d4.
                                                                            
                                                                            
Tcl/Tk(16)                            8.5.12                                *note tkinter: f6,
                                                                            *note IDLE: 1217,
                                                                            *note turtle: 107.
                                                                            
                                                                            
zlib(17)                              1.2.2.1                               *note zlib: 139, *note gzip: 6b,
                                                                            *note ensurepip: 59.
                                                                            
                                                                            
zstd(18)                              1.4.5                                 *note compression.zstd: 23.
                                                                            

Note that the table does not include all optional modules; in
particular, platform-specific modules like *note winreg: 11c. are not
listed here.

Vedi anche
..........

   * The devguide(19) includes a full list of dependencies required to
     build all modules and instructions on how to install them on common
     platforms.

   * *note -with-system-expat: 1b15. allows building with an external
     libexpat(20) library.

   * *note Options for third-party dependencies: 2146.

Cambiato nella versione 3.1: Tcl/Tk version 8.3.1 is now required for
*note tkinter: f6.

Cambiato nella versione 3.5: Tcl/Tk version 8.4 is now required for
*note tkinter: f6.

Cambiato nella versione 3.7: OpenSSL 1.0.2 is now required for *note
hashlib: 6c. and *note ssl: d5.

Cambiato nella versione 3.10: OpenSSL 1.1.1 is now required for *note
hashlib: 6c. and *note ssl: d5.  SQLite 3.7.15 is now required for *note
sqlite3: d4.

Cambiato nella versione 3.11: Tcl/Tk version 8.5.12 is now required for
*note tkinter: f6.

Cambiato nella versione 3.13: SQLite 3.15.2 is now required for *note
sqlite3: d4.

   ---------- Footnotes ----------

   (1) https://sourceware.org/bzip2/

   (2) https://sourceware.org/libffi/

   (3) https://tukaani.org/xz/

   (4) https://www.bytereef.org/mpdecimal/doc/libmpdec/

   (5) If 'libmpdec' is not available, the *note decimal: 3a. module
will use a pure-Python implementation.  See *note -with-system-libmpdec:
657. for details.

   (6) https://tiswww.case.edu/php/chet/readline/rltop.html

   (7) https://www.thrysoee.dk/editline/

   (8) See *note -with-readline: 2144. for choosing the backend for the
*note readline: bf. module.

   (9) https://linux.die.net/man/3/libuuid

   (10) The *note uuid: 116. module uses ‘_uuid’ to generate «safe»
UUIDs.  See the module documentation for details.

   (11) https://gnu.org/software/ncurses/ncurses.html

   (12) The *note curses: 2f. module requires the ‘libncurses’ or
‘libncursesw’ library.  The *note curses.panel: 31. module additionally
requires the ‘libpanel’ or ‘libpanelw’ library.

   (13) https://openssl-library.org/

   (14) If OpenSSL is not available, the *note hashlib: 6c. module will
use bundled implementations of several hash functions.  See *note
-with-builtin-hashlib-hashes: 2145. for 'forcing' usage of OpenSSL.

   (15) https://sqlite.org/

   (16) https://www.tcl-lang.org/

   (17) https://www.zlib.net

   (18) https://facebook.github.io/zstd/

   (19) 
https://devguide.python.org/getting-started/setup-building/#install-dependencies

   (20) https://libexpat.github.io/


File: python.info,  Node: Generated files,  Next: Configure Options,  Prev: Build Requirements,  Up: Configure Python

3.3.2 Generated files
---------------------

To reduce build dependencies, Python source code contains multiple
generated files.  Commands to regenerate all generated files:

     make regen-all
     make regen-stdlib-module-names
     make regen-limited-abi
     make regen-configure

The ‘Makefile.pre.in’ file documents generated files, their inputs, and
tools used to regenerate them.  Search for ‘regen-*’ make targets.

* Menu:

* configure script::


File: python.info,  Node: configure script,  Up: Generated files

3.3.2.1 configure script
........................

The ‘make regen-configure’ command regenerates the ‘aclocal.m4’ file and
the ‘configure’ script using the ‘Tools/build/regen-configure.sh’ shell
script which uses an Ubuntu container to get the same tools versions and
have a reproducible output.

The container is optional, the following command can be run locally:

     autoreconf -ivf -Werror

The generated files can change depending on the exact versions of the
tools used.  The container that CPython uses has Autoconf(1) 2.72,
‘aclocal’ from Automake(2) 1.16.5, and pkg-config(3) 1.8.1.

Cambiato nella versione 3.13: Autoconf 2.71 and aclocal 1.16.5 and are
now used to regenerate ‘configure’.

Cambiato nella versione 3.14: Autoconf 2.72 is now used to regenerate
‘configure’.

   ---------- Footnotes ----------

   (1) https://gnu.org/software/autoconf

   (2) https://www.gnu.org/software/automake

   (3) https://www.freedesktop.org/wiki/Software/pkg-config/


File: python.info,  Node: Configure Options,  Next: Python Build System,  Prev: Generated files,  Up: Configure Python

3.3.3 Configure Options
-----------------------

List all ‘configure’ script options using:

     ./configure --help

See also the ‘Misc/SpecialBuilds.txt’ in the Python source distribution.

* Menu:

* General Options::
* C compiler options::
* Linker options::
* Options for third-party dependencies::
* WebAssembly Options::
* Install Options::
* Performance options::
* Python Debug Build::
* Debug options::
* Linker options: Linker options<2>.
* Libraries options::
* Security Options::
* macOS Options::
* iOS Options::
* Cross Compiling Options::


File: python.info,  Node: General Options,  Next: C compiler options,  Up: Configure Options

3.3.3.1 General Options
.......................

 -- Option: --enable-loadable-sqlite-extensions

     Support loadable extensions in the ‘_sqlite’ extension module
     (default is no) of the *note sqlite3: d4. module.

     See the *note sqlite3.Connection.enable_load_extension(): a41.
     method of the *note sqlite3: d4. module.

     Added in version 3.6.

 -- Option: --disable-ipv6

     Disable IPv6 support (enabled by default if supported), see the
     *note socket: d1. module.

 -- Option: --enable-big-digits=[15|30]

     Define the size in bits of Python *note int: 19b. digits: 15 or 30
     bits.

     By default, the digit size is 30.

     Define the ‘PYLONG_BITS_IN_DIGIT’ to ‘15’ or ‘30’.

     See *note sys.int_info.bits_per_digit: 149b.

 -- Option: --with-suffix=SUFFIX

     Set the Python executable suffix to 'SUFFIX'.

     The default suffix is ‘.exe’ on Windows and macOS (‘python.exe’
     executable), ‘.js’ on Emscripten node, ‘.html’ on Emscripten
     browser, ‘.wasm’ on WASI, and an empty string on other platforms
     (‘python’ executable).

     Cambiato nella versione 3.11: The default suffix on WASM platform
     is one of ‘.js’, ‘.html’ or ‘.wasm’.

 -- Option: --with-tzpath=<list of absolute paths separated by pathsep>

     Select the default time zone search path for *note zoneinfo.TZPATH:
     214f.  See the *note Compile-time configuration: 2150. of the *note
     zoneinfo: 13a. module.

     Default:
     ‘/usr/share/zoneinfo:/usr/lib/zoneinfo:/usr/share/lib/zoneinfo:/etc/zoneinfo’.

     See *note os.pathsep: 211d. path separator.

     Added in version 3.9.

 -- Option: --without-decimal-contextvar

     Build the ‘_decimal’ extension module using a thread-local context
     rather than a coroutine-local context (default), see the *note
     decimal: 3a. module.

     See *note decimal.HAVE_CONTEXTVAR: 2152. and the *note contextvars:
     28. module.

     Added in version 3.9.

 -- Option: --with-dbmliborder=<list of backend names>

     Override order to check db backends for the *note dbm: 35. module

     A valid value is a colon (‘:’) separated string with the backend
     names:

        * ‘ndbm’;

        * ‘gdbm’;

        * ‘bdb’.

 -- Option: --without-c-locale-coercion

     Disable C locale coercion to a UTF-8 based locale (enabled by
     default).

     Don’t define the ‘PY_COERCE_C_LOCALE’ macro.

     See *note PYTHONCOERCECLOCALE: cce. and the PEP 538(1).

 -- Option: --with-platlibdir=DIRNAME

     Python library directory name (default is ‘lib’).

     Fedora and SuSE use ‘lib64’ on 64-bit platforms.

     See *note sys.platlibdir: b34.

     Added in version 3.9.

 -- Option: --with-wheel-pkg-dir=PATH

     Directory of wheel packages used by the *note ensurepip: 59. module
     (none by default).

     Some Linux distribution packaging policies recommend against
     bundling dependencies.  For example, Fedora installs wheel packages
     in the ‘/usr/share/python-wheels/’ directory and don’t install the
     ‘ensurepip._bundled’ package.

     Added in version 3.10.

 -- Option: --with-pkg-config=[check|yes|no]

     Whether configure should use ‘pkg-config’ to detect build
     dependencies.

        * ‘check’ (default): ‘pkg-config’ is optional

        * ‘yes’: ‘pkg-config’ is mandatory

        * ‘no’: configure does not use ‘pkg-config’ even when present

     Added in version 3.11.

 -- Option: --enable-pystats

     Turn on internal Python performance statistics gathering.

     By default, statistics gathering is off.  Use ‘python3 -X pystats’
     command or set ‘PYTHONSTATS=1’ environment variable to turn on
     statistics gathering at Python startup.

     At Python exit, dump statistics if statistics gathering was on and
     not cleared.

     Effects:

        * Add *note -X pystats: 16f. command line option.

        * Add ‘PYTHONSTATS’ environment variable.

        * Define the ‘Py_STATS’ macro.

        * Add functions to the *note sys: df. module:

             * ‘sys._stats_on()’: Turns on statistics gathering.

             * ‘sys._stats_off()’: Turns off statistics gathering.

             * ‘sys._stats_clear()’: Clears the statistics.

             * ‘sys._stats_dump()’: Dump statistics to file, and clears
               the statistics.

     The statistics will be dumped to a arbitrary (probably unique) file
     in ‘/tmp/py_stats/’ (Unix) or ‘C:\temp\py_stats\’ (Windows).  If
     that directory does not exist, results will be printed on stderr.

     Use ‘Tools/scripts/summarize_stats.py’ to read the stats.

     Statistics:

        * Opcode:

             * Specialization: success, failure, hit, deferred, miss,
               deopt, failures;

             * Execution count;

             * Pair count.

        * Call:

             * Inlined Python calls;

             * PyEval calls;

             * Frames pushed;

             * Frame object created;

             * Eval calls: vector, generator, legacy, function
               VECTORCALL, build class, slot, function «ex», API,
               method.

        * Object:

             * incref and decref;

             * interpreter incref and decref;

             * allocations: all, 512 bytes, 4 kiB, big;

             * free;

             * to/from free lists;

             * dictionary materialized/dematerialized;

             * type cache;

             * optimization attempts;

             * optimization traces created/executed;

             * uops executed.

        * Garbage collector:

             * Garbage collections;

             * Objects visited;

             * Objects collected.

     Added in version 3.11.

 -- Option: --disable-gil

     Enables support for running Python without the *note global
     interpreter lock: 474. (GIL): free threading build.

     Defines the ‘Py_GIL_DISABLED’ macro and adds ‘"t"’ to *note
     sys.abiflags: c5b.

     See *note Free-threaded CPython: 46d. for more detail.

     Added in version 3.13.

 -- Option: --enable-experimental-jit=[no|yes|yes-off|interpreter]

     Indicate how to integrate the *note experimental just-in-time
     compiler: 159.

        * ‘no’: Don’t build the JIT.

        * ‘yes’: Enable the JIT. To disable it at runtime, set the
          environment variable *note PYTHON_JIT=0: 44d.

        * ‘yes-off’: Build the JIT, but disable it by default.  To
          enable it at runtime, set the environment variable *note
          PYTHON_JIT=1: 44d.

        * ‘interpreter’: Enable the «JIT interpreter» (only useful for
          those debugging the JIT itself).  To disable it at runtime,
          set the environment variable *note PYTHON_JIT=0: 44d.

     ‘--enable-experimental-jit=no’ is the default behavior if the
     option is not provided, and ‘--enable-experimental-jit’ is
     shorthand for ‘--enable-experimental-jit=yes’.  See
     ‘Tools/jit/README.md’ for more information, including how to
     install the necessary build-time dependencies.

          Nota: When building CPython with JIT enabled, ensure that your
          system has Python 3.11 or later installed.

     Added in version 3.13.

 -- Option: PKG_CONFIG

     Path to ‘pkg-config’ utility.

 -- Option: PKG_CONFIG_LIBDIR

 -- Option: PKG_CONFIG_PATH

     ‘pkg-config’ options.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0538/


File: python.info,  Node: C compiler options,  Next: Linker options,  Prev: General Options,  Up: Configure Options

3.3.3.2 C compiler options
..........................

 -- Option: CC

     C compiler command.

 -- Option: CFLAGS

     C compiler flags.

 -- Option: CPP

     C preprocessor command.

 -- Option: CPPFLAGS

     C preprocessor flags, e.g.  ‘-IINCLUDE_DIR’.


File: python.info,  Node: Linker options,  Next: Options for third-party dependencies,  Prev: C compiler options,  Up: Configure Options

3.3.3.3 Linker options
......................

 -- Option: LDFLAGS

     Linker flags, e.g.  ‘-LLIBRARY_DIRECTORY’.

 -- Option: LIBS

     Libraries to pass to the linker, e.g.  ‘-lLIBRARY’.

 -- Option: MACHDEP

     Name for machine-dependent library files.


File: python.info,  Node: Options for third-party dependencies,  Next: WebAssembly Options,  Prev: Linker options,  Up: Configure Options

3.3.3.4 Options for third-party dependencies
............................................

Added in version 3.11.

 -- Option: BZIP2_CFLAGS

 -- Option: BZIP2_LIBS

     C compiler and linker flags to link Python to ‘libbz2’, used by
     *note bz2: 14. module, overriding ‘pkg-config’.

 -- Option: CURSES_CFLAGS

 -- Option: CURSES_LIBS

     C compiler and linker flags for ‘libncurses’ or ‘libncursesw’, used
     by *note curses: 2f. module, overriding ‘pkg-config’.

 -- Option: GDBM_CFLAGS

 -- Option: GDBM_LIBS

     C compiler and linker flags for ‘gdbm’.

 -- Option: LIBEDIT_CFLAGS

 -- Option: LIBEDIT_LIBS

     C compiler and linker flags for ‘libedit’, used by *note readline:
     bf. module, overriding ‘pkg-config’.

 -- Option: LIBFFI_CFLAGS

 -- Option: LIBFFI_LIBS

     C compiler and linker flags for ‘libffi’, used by *note ctypes: 2e.
     module, overriding ‘pkg-config’.

 -- Option: LIBMPDEC_CFLAGS

 -- Option: LIBMPDEC_LIBS

     C compiler and linker flags for ‘libmpdec’, used by *note decimal:
     3a. module, overriding ‘pkg-config’.

          Nota: These environment variables have no effect unless *note
          -with-system-libmpdec: 657. is specified.

 -- Option: LIBLZMA_CFLAGS

 -- Option: LIBLZMA_LIBS

     C compiler and linker flags for ‘liblzma’, used by *note lzma: 8e.
     module, overriding ‘pkg-config’.

 -- Option: LIBREADLINE_CFLAGS

 -- Option: LIBREADLINE_LIBS

     C compiler and linker flags for ‘libreadline’, used by *note
     readline: bf. module, overriding ‘pkg-config’.

 -- Option: LIBSQLITE3_CFLAGS

 -- Option: LIBSQLITE3_LIBS

     C compiler and linker flags for ‘libsqlite3’, used by *note
     sqlite3: d4. module, overriding ‘pkg-config’.

 -- Option: LIBUUID_CFLAGS

 -- Option: LIBUUID_LIBS

     C compiler and linker flags for ‘libuuid’, used by *note uuid: 116.
     module, overriding ‘pkg-config’.

 -- Option: LIBZSTD_CFLAGS

 -- Option: LIBZSTD_LIBS

     C compiler and linker flags for ‘libzstd’, used by *note
     compression.zstd: 23. module, overriding ‘pkg-config’.

     Added in version 3.14.

 -- Option: PANEL_CFLAGS

 -- Option: PANEL_LIBS

     C compiler and linker flags for PANEL, overriding ‘pkg-config’.

     C compiler and linker flags for ‘libpanel’ or ‘libpanelw’, used by
     *note curses.panel: 31. module, overriding ‘pkg-config’.

 -- Option: TCLTK_CFLAGS

 -- Option: TCLTK_LIBS

     C compiler and linker flags for TCLTK, overriding ‘pkg-config’.

 -- Option: ZLIB_CFLAGS

 -- Option: ZLIB_LIBS

     C compiler and linker flags for ‘libzlib’, used by *note gzip: 6b.
     module, overriding ‘pkg-config’.


File: python.info,  Node: WebAssembly Options,  Next: Install Options,  Prev: Options for third-party dependencies,  Up: Configure Options

3.3.3.5 WebAssembly Options
...........................

 -- Option: --enable-wasm-dynamic-linking

     Turn on dynamic linking support for WASM.

     Dynamic linking enables ‘dlopen’.  File size of the executable
     increases due to limited dead code elimination and additional
     features.

     Added in version 3.11.

 -- Option: --enable-wasm-pthreads

     Turn on pthreads support for WASM.

     Added in version 3.11.


File: python.info,  Node: Install Options,  Next: Performance options,  Prev: WebAssembly Options,  Up: Configure Options

3.3.3.6 Install Options
.......................

 -- Option: --prefix=PREFIX

     Install architecture-independent files in PREFIX. On Unix, it
     defaults to ‘/usr/local’.

     This value can be retrieved at runtime using *note sys.prefix: 3e7.

     As an example, one can use ‘--prefix="$HOME/.local/"’ to install a
     Python in its home directory.

 -- Option: --exec-prefix=EPREFIX

     Install architecture-dependent files in EPREFIX, defaults to *note
     -prefix: 2138.

     This value can be retrieved at runtime using *note sys.exec_prefix:
     3eb.

 -- Option: --disable-test-modules

     Don’t build nor install test modules, like the *note test: e8.
     package or the ‘_testcapi’ extension module (built and installed by
     default).

     Added in version 3.10.

 -- Option: --with-ensurepip=[upgrade|install|no]

     Select the *note ensurepip: 59. command run on Python installation:

        * ‘upgrade’ (default): run ‘python -m ensurepip --altinstall
          --upgrade’ command.

        * ‘install’: run ‘python -m ensurepip --altinstall’ command;

        * ‘no’: don’t run ensurepip;

     Added in version 3.6.


File: python.info,  Node: Performance options,  Next: Python Debug Build,  Prev: Install Options,  Up: Configure Options

3.3.3.7 Performance options
...........................

Configuring Python using ‘--enable-optimizations --with-lto’ (PGO + LTO)
is recommended for best performance.  The experimental ‘--enable-bolt’
flag can also be used to improve performance.

 -- Option: --enable-optimizations

     Enable Profile Guided Optimization (PGO) using *note PROFILE_TASK:
     1a66. (disabled by default).

     The C compiler Clang requires ‘llvm-profdata’ program for PGO. On
     macOS, GCC also requires it: GCC is just an alias to Clang on
     macOS.

     Disable also semantic interposition in libpython if
     ‘--enable-shared’ and GCC is used: add
     ‘-fno-semantic-interposition’ to the compiler and linker flags.

          Nota: During the build, you may encounter compiler warnings
          about profile data not being available for some source files.
          These warnings are harmless, as only a subset of the code is
          exercised during profile data acquisition.  To disable these
          warnings on Clang, manually suppress them by adding
          ‘-Wno-profile-instr-unprofiled’ to *note CFLAGS: 16be.

     Added in version 3.6.

     Cambiato nella versione 3.10: Use ‘-fno-semantic-interposition’ on
     GCC.

 -- Variabile d'ambiente: PROFILE_TASK

     Environment variable used in the Makefile: Python command line
     arguments for the PGO generation task.

     Default: ‘-m test --pgo --timeout=$(TESTTIMEOUT)’.

     Added in version 3.8.

     Cambiato nella versione 3.13: Task failure is no longer ignored
     silently.

 -- Option: --with-lto=[full|thin|no|yes]

     Enable Link Time Optimization (LTO) in any build (disabled by
     default).

     The C compiler Clang requires ‘llvm-ar’ for LTO (‘ar’ on macOS), as
     well as an LTO-aware linker (‘ld.gold’ or ‘lld’).

     Added in version 3.6.

     Added in version 3.11: To use ThinLTO feature, use
     ‘--with-lto=thin’ on Clang.

     Cambiato nella versione 3.12: Use ThinLTO as the default
     optimization policy on Clang if the compiler accepts the flag.

 -- Option: --enable-bolt

     Enable usage of the BOLT post-link binary optimizer(1) (disabled by
     default).

     BOLT is part of the LLVM project but is not always included in
     their binary distributions.  This flag requires that ‘llvm-bolt’
     and ‘merge-fdata’ are available.

     BOLT is still a fairly new project so this flag should be
     considered experimental for now.  Because this tool operates on
     machine code its success is dependent on a combination of the build
     environment + the other optimization configure args + the CPU
     architecture, and not all combinations are supported.  BOLT
     versions before LLVM 16 are known to crash BOLT under some
     scenarios.  Use of LLVM 16 or newer for BOLT optimization is
     strongly encouraged.

     The ‘BOLT_INSTRUMENT_FLAGS’ and ‘BOLT_APPLY_FLAGS’ ‘configure’
     variables can be defined to override the default set of arguments
     for ‘llvm-bolt’ to instrument and apply BOLT data to binaries,
     respectively.

     Added in version 3.12.

 -- Option: BOLT_APPLY_FLAGS

     Arguments to ‘llvm-bolt’ when creating a BOLT optimized binary(2).

     Added in version 3.12.

 -- Option: BOLT_INSTRUMENT_FLAGS

     Arguments to ‘llvm-bolt’ when instrumenting binaries.

     Added in version 3.12.

 -- Option: --with-computed-gotos

     Enable computed gotos in evaluation loop (enabled by default on
     supported compilers).

 -- Option: --with-tail-call-interp

     Enable interpreters using tail calls in CPython.  If enabled,
     enabling PGO (*note -enable-optimizations: a64.) is highly
     recommended.  This option specifically requires a C compiler with
     proper tail call support, and the preserve_none(3) calling
     convention.  For example, Clang 19 and newer supports this feature.

     Added in version 3.14.

 -- Option: --without-mimalloc

     Disable the fast *note mimalloc: 2126. allocator (enabled by
     default).

     See also *note PYTHONMALLOC: e60. environment variable.

 -- Option: --without-pymalloc

     Disable the specialized Python memory allocator *note pymalloc:
     f0d. (enabled by default).

     See also *note PYTHONMALLOC: e60. environment variable.

 -- Option: --without-doc-strings

     Disable static documentation strings to reduce the memory footprint
     (enabled by default).  Documentation strings defined in Python are
     not affected.

     Don’t define the ‘WITH_DOC_STRINGS’ macro.

     See the ‘PyDoc_STRVAR()’ macro.

 -- Option: --enable-profiling

     Enable C-level code profiling with ‘gprof’ (disabled by default).

 -- Option: --with-strict-overflow

     Add ‘-fstrict-overflow’ to the C compiler flags (by default we add
     ‘-fno-strict-overflow’ instead).

 -- Option: --without-remote-debug

     Deactivate remote debugging support described in PEP 768(4)
     (enabled by default).  When this flag is provided the code that
     allows the interpreter to schedule the execution of a Python file
     in a separate process as described in PEP 768(5) is not compiled.
     This includes both the functionality to schedule code to be
     executed and the functionality to receive code to be executed.

      -- C Macro: Py_REMOTE_DEBUG

          This macro is defined by default, unless Python is configured
          with *note -without-remote-debug: 170.

          Note that even if the macro is defined, remote debugging may
          not be available (for example, on an incompatible platform).

     Added in version 3.14.

   ---------- Footnotes ----------

   (1) https://github.com/llvm/llvm-project/tree/main/bolt

   (2) https://github.com/facebookarchive/BOLT

   (3) https://clang.llvm.org/docs/AttributeReference.html#preserve-none

   (4) https://peps.python.org/pep-0768/

   (5) https://peps.python.org/pep-0768/


File: python.info,  Node: Python Debug Build,  Next: Debug options,  Prev: Performance options,  Up: Configure Options

3.3.3.8 Python Debug Build
..........................

A debug build is Python built with the *note -with-pydebug: 666.
configure option.

Effects of a debug build:

   * Display all warnings by default: the list of default warning
     filters is empty in the *note warnings: 118. module.

   * Add ‘d’ to *note sys.abiflags: c5b.

   * Add ‘sys.gettotalrefcount()’ function.

   * Add *note -X showrefcount: 16f. command line option.

   * Add *note -d: 210c. command line option and *note PYTHONDEBUG:
     210d. environment variable to debug the parser.

   * Add support for the ‘__lltrace__’ variable: enable low-level
     tracing in the bytecode evaluation loop if the variable is defined.

   * Install *note debug hooks on memory allocators: 2124. to detect
     buffer overflow and other memory errors.

   * Define ‘Py_DEBUG’ and ‘Py_REF_DEBUG’ macros.

   * Add runtime checks: code surrounded by ‘#ifdef Py_DEBUG’ and
     ‘#endif’.  Enable ‘assert(...)’ and ‘_PyObject_ASSERT(...)’
     assertions: don’t set the ‘NDEBUG’ macro (see also the *note
     -with-assertions: 62d. configure option).  Main runtime checks:

        * Add sanity checks on the function arguments.

        * Unicode and int objects are created with their memory filled
          with a pattern to detect usage of uninitialized objects.

        * Ensure that functions which can clear or replace the current
          exception are not called with an exception raised.

        * Check that deallocator functions don’t change the current
          exception.

        * The garbage collector (*note gc.collect(): 1b3. function) runs
          some basic checks on objects consistency.

        * The ‘Py_SAFE_DOWNCAST()’ macro checks for integer underflow
          and overflow when downcasting from wide types to narrow types.

See also the *note Python Development Mode: 509. and the *note
-with-trace-refs: 636. configure option.

Cambiato nella versione 3.8: Release builds and debug builds are now ABI
compatible: defining the ‘Py_DEBUG’ macro no longer implies the
‘Py_TRACE_REFS’ macro (see the *note -with-trace-refs: 636. option).


File: python.info,  Node: Debug options,  Next: Linker options<2>,  Prev: Python Debug Build,  Up: Configure Options

3.3.3.9 Debug options
.....................

 -- Option: --with-pydebug

     *note Build Python in debug mode: 50a.: define the ‘Py_DEBUG’ macro
     (disabled by default).

 -- Option: --with-trace-refs

     Enable tracing references for debugging purpose (disabled by
     default).

     Effects:

        * Define the ‘Py_TRACE_REFS’ macro.

        * Add *note sys.getobjects(): 28e. function.

        * Add *note PYTHONDUMPREFS: ba0. environment variable.

     The *note PYTHONDUMPREFS: ba0. environment variable can be used to
     dump objects and reference counts still alive at Python exit.

     *note Statically allocated objects: 984. are not traced.

     Added in version 3.8.

     Cambiato nella versione 3.13: This build is now ABI compatible with
     release build and *note debug build: 50a.

 -- Option: --with-assertions

     Build with C assertions enabled (default is no): ‘assert(...);’ and
     ‘_PyObject_ASSERT(...);’.

     If set, the ‘NDEBUG’ macro is not defined in the *note OPT: 2190.
     compiler variable.

     See also the *note -with-pydebug: 666. option (*note debug build:
     50a.) which also enables assertions.

     Added in version 3.6.

 -- Option: --with-valgrind

     Enable Valgrind support (default is no).

 -- Option: --with-dtrace

     Enable DTrace support (default is no).

     See *note Instrumenting CPython with DTrace and SystemTap: e68.

     Added in version 3.6.

 -- Option: --with-address-sanitizer

     Enable AddressSanitizer memory error detector, ‘asan’ (default is
     no).  To improve ASan detection capabilities you may also want to
     combine this with *note -without-pymalloc: 218a. to disable the
     specialized small-object allocator whose allocations are not
     tracked by ASan.

     Added in version 3.6.

 -- Option: --with-memory-sanitizer

     Enable MemorySanitizer allocation error detector, ‘msan’ (default
     is no).

     Added in version 3.6.

 -- Option: --with-undefined-behavior-sanitizer

     Enable UndefinedBehaviorSanitizer undefined behaviour detector,
     ‘ubsan’ (default is no).

     Added in version 3.6.

 -- Option: --with-thread-sanitizer

     Enable ThreadSanitizer data race detector, ‘tsan’ (default is no).

     Added in version 3.13.


File: python.info,  Node: Linker options<2>,  Next: Libraries options,  Prev: Debug options,  Up: Configure Options

3.3.3.10 Linker options
.......................

 -- Option: --enable-shared

     Enable building a shared Python library: ‘libpython’ (default is
     no).

 -- Option: --without-static-libpython

     Do not build ‘libpythonMAJOR.MINOR.a’ and do not install ‘python.o’
     (built and enabled by default).

     Added in version 3.10.


File: python.info,  Node: Libraries options,  Next: Security Options,  Prev: Linker options<2>,  Up: Configure Options

3.3.3.11 Libraries options
..........................

 -- Option: --with-libs='lib1 ...'

     Link against additional libraries (default is no).

 -- Option: --with-system-expat

     Build the ‘pyexpat’ module using an installed ‘expat’ library
     (default is no).

 -- Option: --with-system-libmpdec

     Build the ‘_decimal’ extension module using an installed
     ‘mpdecimal’ library, see the *note decimal: 3a. module (default is
     yes).

     Added in version 3.3.

     Cambiato nella versione 3.13: Default to using the installed
     ‘mpdecimal’ library.

     Cambiato nella versione 3.15: A bundled copy of the library will no
     longer be selected implicitly if an installed ‘mpdecimal’ library
     is not found.  In Python 3.15 only, it can still be selected
     explicitly using ‘--with-system-libmpdec=no’ or
     ‘--without-system-libmpdec’.

     Deprecated since version 3.13, will be removed in version 3.16: A
     copy of the ‘mpdecimal’ library sources will no longer be
     distributed with Python 3.16.

     Vedi anche
     ..........

     *note LIBMPDEC_CFLAGS: 216f. and *note LIBMPDEC_LIBS: 2170.

 -- Option: --with-readline=readline|editline

     Designate a backend library for the *note readline: bf. module.

        * readline: Use readline as the backend.

        * editline: Use editline as the backend.

     Added in version 3.10.

 -- Option: --without-readline

     Don’t build the *note readline: bf. module (built by default).

     Don’t define the ‘HAVE_LIBREADLINE’ macro.

     Added in version 3.10.

 -- Option: --with-libm=STRING

     Override ‘libm’ math library to 'STRING' (default is
     system-dependent).

 -- Option: --with-libc=STRING

     Override ‘libc’ C library to 'STRING' (default is
     system-dependent).

 -- Option: --with-openssl=DIR

     Root of the OpenSSL directory.

     Added in version 3.7.

 -- Option: --with-openssl-rpath=[no|auto|DIR]

     Set runtime library directory (rpath) for OpenSSL libraries:

        * ‘no’ (default): don’t set rpath;

        * ‘auto’: auto-detect rpath from *note -with-openssl: 219d. and
          ‘pkg-config’;

        * 'DIR': set an explicit rpath.

     Added in version 3.10.


File: python.info,  Node: Security Options,  Next: macOS Options,  Prev: Libraries options,  Up: Configure Options

3.3.3.12 Security Options
.........................

 -- Option: --with-hash-algorithm=[fnv|siphash13|siphash24]

     Select hash algorithm for use in ‘Python/pyhash.c’:

        * ‘siphash13’ (default);

        * ‘siphash24’;

        * ‘fnv’.

     Added in version 3.4.

     Added in version 3.11: ‘siphash13’ is added and it is the new
     default.

 -- Option:
          --with-builtin-hashlib-hashes=md5,sha1,sha256,sha512,sha3,blake2

     Built-in hash modules:

        * ‘md5’;

        * ‘sha1’;

        * ‘sha256’;

        * ‘sha512’;

        * ‘sha3’ (with shake);

        * ‘blake2’.

     Added in version 3.9.

 -- Option: --with-ssl-default-suites=[python|openssl|STRING]

     Override the OpenSSL default cipher suites string:

        * ‘python’ (default): use Python’s preferred selection;

        * ‘openssl’: leave OpenSSL’s defaults untouched;

        * 'STRING': use a custom string

     See the *note ssl: d5. module.

     Added in version 3.7.

     Cambiato nella versione 3.10: The settings ‘python’ and 'STRING'
     also set TLS 1.2 as minimum protocol version.

 -- Option: --disable-safety

     Disable compiler options that are recommended by OpenSSF(1) for
     security reasons with no performance overhead.  If this option is
     not enabled, CPython will be built based on safety compiler options
     with no slow down.  When this option is enabled, CPython will not
     be built with the compiler options listed below.

     The following compiler options are disabled with
     ‘--disable-safety’:

        * -fstack-protector-strong(2): Enable run-time checks for
          stack-based buffer overflows.

        * -Wtrampolines(3): Enable warnings about trampolines that
          require executable stacks.

     Added in version 3.14.

 -- Option: --enable-slower-safety

     Enable compiler options that are recommended by OpenSSF(4) for
     security reasons which require overhead.  If this option is not
     enabled, CPython will not be built based on safety compiler options
     which performance impact.  When this option is enabled, CPython
     will be built with the compiler options listed below.

     The following compiler options are enabled with
     ‘--enable-slower-safety’:

        * -D_FORTIFY_SOURCE=3(5): Fortify sources with compile- and
          run-time checks for unsafe libc usage and buffer overflows.

     Added in version 3.14.

   ---------- Footnotes ----------

   (1) 
https://github.com/ossf/wg-best-practices-os-developers/blob/main/docs/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C++.md

   (2) 
https://github.com/ossf/wg-best-practices-os-developers/blob/main/docs/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C++.md#enable-run-time-checks-for-stack-based-buffer-overflows

   (3) 
https://github.com/ossf/wg-best-practices-os-developers/blob/main/docs/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C++.md#enable-warning-about-trampolines-that-require-executable-stacks

   (4) 
https://github.com/ossf/wg-best-practices-os-developers/blob/main/docs/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C++.md

   (5) 
https://github.com/ossf/wg-best-practices-os-developers/blob/main/docs/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C++.md#fortify-sources-for-unsafe-libc-usage-and-buffer-overflows


File: python.info,  Node: macOS Options,  Next: iOS Options,  Prev: Security Options,  Up: Configure Options

3.3.3.13 macOS Options
......................

See Mac/README.rst(1).

 -- Option: --enable-universalsdk

 -- Option: --enable-universalsdk=SDKDIR

     Create a universal binary build.  'SDKDIR' specifies which macOS
     SDK should be used to perform the build (default is no).

 -- Option: --enable-framework

 -- Option: --enable-framework=INSTALLDIR

     Create a Python.framework rather than a traditional Unix install.
     Optional 'INSTALLDIR' specifies the installation path (default is
     no).

 -- Option: --with-universal-archs=ARCH

     Specify the kind of universal binary that should be created.  This
     option is only valid when *note -enable-universalsdk: b65. is set.

     Options:

        * ‘universal2’ (x86-64 and arm64);

        * ‘32-bit’ (PPC and i386);

        * ‘64-bit’ (PPC64 and x86-64);

        * ‘3-way’ (i386, PPC and x86-64);

        * ‘intel’ (i386 and x86-64);

        * ‘intel-32’ (i386);

        * ‘intel-64’ (x86-64);

        * ‘all’ (PPC, i386, PPC64 and x86-64).

     Note that values for this configuration item are 'not' the same as
     the identifiers used for universal binary wheels on macOS. See the
     Python Packaging User Guide for details on the packaging platform
     compatibility tags used on macOS(2)

 -- Option: --with-framework-name=FRAMEWORK

     Specify the name for the python framework on macOS only valid when
     *note -enable-framework: 21a3. is set (default: ‘Python’).

 -- Option: --with-app-store-compliance

 -- Option: --with-app-store-compliance=PATCH-FILE

     The Python standard library contains strings that are known to
     trigger automated inspection tool errors when submitted for
     distribution by the macOS and iOS App Stores.  If enabled, this
     option will apply the list of patches that are known to correct app
     store compliance.  A custom patch file can also be specified.  This
     option is disabled by default.

     Added in version 3.13.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Mac/README.rst

   (2) 
https://packaging.python.org/en/latest/specifications/platform-compatibility-tags/#macos


File: python.info,  Node: iOS Options,  Next: Cross Compiling Options,  Prev: macOS Options,  Up: Configure Options

3.3.3.14 iOS Options
....................

See iOS/README.rst(1).

 -- Option: --enable-framework=INSTALLDIR

     Create a Python.framework.  Unlike macOS, the 'INSTALLDIR' argument
     specifying the installation path is mandatory.

 -- Option: --with-framework-name=FRAMEWORK

     Specify the name for the framework (default: ‘Python’).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/iOS/README.rst


File: python.info,  Node: Cross Compiling Options,  Prev: iOS Options,  Up: Configure Options

3.3.3.15 Cross Compiling Options
................................

Cross compiling, also known as cross building, can be used to build
Python for another CPU architecture or platform.  Cross compiling
requires a Python interpreter for the build platform.  The version of
the build Python must match the version of the cross compiled host
Python.

 -- Option: --build=BUILD

     configure for building on BUILD, usually guessed by ‘config.guess’.

 -- Option: --host=HOST

     cross-compile to build programs to run on HOST (target platform)

 -- Option: --with-build-python=path/to/python

     path to build ‘python’ binary for cross compiling

     Added in version 3.11.

 -- Option: CONFIG_SITE=file

     An environment variable that points to a file with configure
     overrides.

     Example 'config.site' file:

          # config.site-aarch64
          ac_cv_buggy_getaddrinfo=no
          ac_cv_file__dev_ptmx=yes
          ac_cv_file__dev_ptc=no

 -- Option: HOSTRUNNER

     Program to run CPython for the host platform for cross-compilation.

     Added in version 3.11.

Cross compiling example:

     CONFIG_SITE=config.site-aarch64 ../configure \
         --build=x86_64-pc-linux-gnu \
         --host=aarch64-unknown-linux-gnu \
         --with-build-python=../x86_64/python


File: python.info,  Node: Python Build System,  Next: Compiler and linker flags,  Prev: Configure Options,  Up: Configure Python

3.3.4 Python Build System
-------------------------

* Menu:

* Main files of the build system::
* Main build steps::
* Main Makefile targets::
* C extensions::


File: python.info,  Node: Main files of the build system,  Next: Main build steps,  Up: Python Build System

3.3.4.1 Main files of the build system
......................................

   * ‘configure.ac’ => ‘configure’;

   * ‘Makefile.pre.in’ => ‘Makefile’ (created by ‘configure’);

   * ‘pyconfig.h’ (created by ‘configure’);

   * ‘Modules/Setup’: C extensions built by the Makefile using
     ‘Module/makesetup’ shell script;


File: python.info,  Node: Main build steps,  Next: Main Makefile targets,  Prev: Main files of the build system,  Up: Python Build System

3.3.4.2 Main build steps
........................

   * C files (‘.c’) are built as object files (‘.o’).

   * A static ‘libpython’ library (‘.a’) is created from objects files.

   * ‘python.o’ and the static ‘libpython’ library are linked into the
     final ‘python’ program.

   * C extensions are built by the Makefile (see ‘Modules/Setup’).


File: python.info,  Node: Main Makefile targets,  Next: C extensions,  Prev: Main build steps,  Up: Python Build System

3.3.4.3 Main Makefile targets
.............................

* Menu:

* make::
* make platform::
* make profile-opt::
* make clean::
* make distclean::
* make install::
* make test::
* make ci::
* make buildbottest::
* make regen-all::


File: python.info,  Node: make,  Next: make platform,  Up: Main Makefile targets

3.3.4.4 make
............

For the most part, when rebuilding after editing some code or refreshing
your checkout from upstream, all you need to do is execute ‘make’, which
(per Make’s semantics) builds the default target, the first one defined
in the Makefile.  By tradition (including in the CPython project) this
is usually the ‘all’ target.  The ‘configure’ script expands an
‘autoconf’ variable, ‘@DEF_MAKE_ALL_RULE@’ to describe precisely which
targets ‘make all’ will build.  The three choices are:

   * ‘profile-opt’ (configured with ‘--enable-optimizations’)

   * ‘build_wasm’ (chosen if the host platform matches ‘wasm32-wasi*’ or
     ‘wasm32-emscripten’)

   * ‘build_all’ (configured without explicitly using either of the
     others)

Depending on the most recent source file changes, Make will rebuild any
targets (object files and executables) deemed out-of-date, including
running ‘configure’ again if necessary.  Source/target dependencies are
many and maintained manually however, so Make sometimes doesn’t have all
the information necessary to correctly detect all targets which need to
be rebuilt.  Depending on which targets aren’t rebuilt, you might
experience a number of problems.  If you have build or test problems
which you can’t otherwise explain, ‘make clean && make’ should work
around most dependency problems, at the expense of longer build times.


File: python.info,  Node: make platform,  Next: make profile-opt,  Prev: make,  Up: Main Makefile targets

3.3.4.5 make platform
.....................

Build the ‘python’ program, but don’t build the standard library
extension modules.  This generates a file named ‘platform’ which
contains a single line describing the details of the build platform,
e.g., ‘macosx-14.3-arm64-3.12’ or ‘linux-x86_64-3.13’.


File: python.info,  Node: make profile-opt,  Next: make clean,  Prev: make platform,  Up: Main Makefile targets

3.3.4.6 make profile-opt
........................

Build Python using profile-guided optimization (PGO). You can use the
configure *note -enable-optimizations: a64. option to make this the
default target of the ‘make’ command (‘make all’ or just ‘make’).


File: python.info,  Node: make clean,  Next: make distclean,  Prev: make profile-opt,  Up: Main Makefile targets

3.3.4.7 make clean
..................

Remove built files.


File: python.info,  Node: make distclean,  Next: make install,  Prev: make clean,  Up: Main Makefile targets

3.3.4.8 make distclean
......................

In addition to the work done by ‘make clean’, remove files created by
the configure script.  ‘configure’ will have to be run before building
again.  (1)

   ---------- Footnotes ----------

   (1) ‘git clean -fdx’ is an even more extreme way to «clean» your
checkout.  It removes all files not known to Git.  When bug hunting
using ‘git bisect’, this is recommended between probes
(https://github.com/python/cpython/issues/114505#issuecomment-1907021718)
to guarantee a completely clean build.  'Use with care', as it will
delete all files not checked into Git, including your new, uncommitted
work.


File: python.info,  Node: make install,  Next: make test,  Prev: make distclean,  Up: Main Makefile targets

3.3.4.9 make install
....................

Build the ‘all’ target and install Python.


File: python.info,  Node: make test,  Next: make ci,  Prev: make install,  Up: Main Makefile targets

3.3.4.10 make test
..................

Build the ‘all’ target and run the Python test suite with the
‘--fast-ci’ option without GUI tests.  Variables:

   * ‘TESTOPTS’: additional regrtest command-line options.

   * ‘TESTPYTHONOPTS’: additional Python command-line options.

   * ‘TESTTIMEOUT’: timeout in seconds (default: 10 minutes).


File: python.info,  Node: make ci,  Next: make buildbottest,  Prev: make test,  Up: Main Makefile targets

3.3.4.11 make ci
................

This is similar to ‘make test’, but uses the ‘-ugui’ to also run GUI
tests.

Added in version 3.14.


File: python.info,  Node: make buildbottest,  Next: make regen-all,  Prev: make ci,  Up: Main Makefile targets

3.3.4.12 make buildbottest
..........................

This is similar to ‘make test’, but uses the ‘--slow-ci’ option and
default timeout of 20 minutes, instead of ‘--fast-ci’ option.


File: python.info,  Node: make regen-all,  Prev: make buildbottest,  Up: Main Makefile targets

3.3.4.13 make regen-all
.......................

Regenerate (almost) all generated files.  These include (but are not
limited to) bytecode cases, and parser generator file.  ‘make
regen-stdlib-module-names’ and ‘autoconf’ must be run separately for the
remaining *note generated files: 2147.


File: python.info,  Node: C extensions,  Prev: Main Makefile targets,  Up: Python Build System

3.3.4.14 C extensions
.....................

Some C extensions are built as built-in modules, like the ‘sys’ module.
They are built with the ‘Py_BUILD_CORE_BUILTIN’ macro defined.  Built-in
modules have no ‘__file__’ attribute:

     >>> import sys
     >>> sys
     <module 'sys' (built-in)>
     >>> sys.__file__
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     AttributeError: module 'sys' has no attribute '__file__'

Other C extensions are built as dynamic libraries, like the ‘_asyncio’
module.  They are built with the ‘Py_BUILD_CORE_MODULE’ macro defined.
Example on Linux x86-64:

     >>> import _asyncio
     >>> _asyncio
     <module '_asyncio' from '/usr/lib64/python3.9/lib-dynload/_asyncio.cpython-39-x86_64-linux-gnu.so'>
     >>> _asyncio.__file__
     '/usr/lib64/python3.9/lib-dynload/_asyncio.cpython-39-x86_64-linux-gnu.so'

‘Modules/Setup’ is used to generate Makefile targets to build C
extensions.  At the beginning of the files, C extensions are built as
built-in modules.  Extensions defined after the ‘*shared*’ marker are
built as dynamic libraries.

The ‘PyAPI_FUNC()’, ‘PyAPI_DATA()’ and *note PyMODINIT_FUNC: 16da.
macros of ‘Include/exports.h’ are defined differently depending if the
‘Py_BUILD_CORE_MODULE’ macro is defined:

   * Use ‘Py_EXPORTED_SYMBOL’ if the ‘Py_BUILD_CORE_MODULE’ is defined

   * Use ‘Py_IMPORTED_SYMBOL’ otherwise.

If the ‘Py_BUILD_CORE_BUILTIN’ macro is used by mistake on a C extension
built as a shared library, its ‘PyInit_XXX()’ function is not exported,
causing an *note ImportError: 65b. on import.


File: python.info,  Node: Compiler and linker flags,  Prev: Python Build System,  Up: Configure Python

3.3.5 Compiler and linker flags
-------------------------------

Options set by the ‘./configure’ script and environment variables and
used by ‘Makefile’.

* Menu:

* Preprocessor flags::
* Compiler flags::
* Linker flags::


File: python.info,  Node: Preprocessor flags,  Next: Compiler flags,  Up: Compiler and linker flags

3.3.5.1 Preprocessor flags
..........................

 -- Variabile d'ambiente: CONFIGURE_CPPFLAGS

     Value of *note CPPFLAGS: 16c0. variable passed to the ‘./configure’
     script.

     Added in version 3.6.

 -- Variabile d'ambiente: CPPFLAGS

     (Objective) C/C++ preprocessor flags, e.g.  ‘-IINCLUDE_DIR’ if you
     have headers in a nonstandard directory 'include_dir'.

     Both *note CPPFLAGS: 16c0. and *note LDFLAGS: 16bf. need to contain
     the shell’s value to be able to build extension modules using the
     directories specified in the environment variables.

 -- Variabile d'ambiente: BASECPPFLAGS

     Added in version 3.4.

 -- Variabile d'ambiente: PY_CPPFLAGS

     Extra preprocessor flags added for building the interpreter object
     files.

     Default: ‘$(BASECPPFLAGS) -I. -I$(srcdir)/Include
     $(CONFIGURE_CPPFLAGS) $(CPPFLAGS)’.

     Added in version 3.2.


File: python.info,  Node: Compiler flags,  Next: Linker flags,  Prev: Preprocessor flags,  Up: Compiler and linker flags

3.3.5.2 Compiler flags
......................

 -- Variabile d'ambiente: CC

     C compiler command.

     Example: ‘gcc -pthread’.

 -- Variabile d'ambiente: CXX

     C++ compiler command.

     Example: ‘g++ -pthread’.

 -- Variabile d'ambiente: CFLAGS

     C compiler flags.

 -- Variabile d'ambiente: CFLAGS_NODIST

     *note CFLAGS_NODIST: 21c7. is used for building the interpreter and
     stdlib C extensions.  Use it when a compiler flag should 'not' be
     part of *note CFLAGS: 16be. once Python is installed (gh-65320(1)).

     In particular, *note CFLAGS: 16be. should not contain:

        * the compiler flag ‘-I’ (for setting the search path for
          include files).  The ‘-I’ flags are processed from left to
          right, and any flags in *note CFLAGS: 16be. would take
          precedence over user- and package-supplied ‘-I’ flags.

        * hardening flags such as ‘-Werror’ because distributions cannot
          control whether packages installed by users conform to such
          heightened standards.

     Added in version 3.5.

 -- Variabile d'ambiente: COMPILEALL_OPTS

     Options passed to the *note compileall: 21. command line when
     building PYC files in ‘make install’.  Default: ‘-j0’.

     Added in version 3.12.

 -- Variabile d'ambiente: EXTRA_CFLAGS

     Extra C compiler flags.

 -- Variabile d'ambiente: CONFIGURE_CFLAGS

     Value of *note CFLAGS: 16be. variable passed to the ‘./configure’
     script.

     Added in version 3.2.

 -- Variabile d'ambiente: CONFIGURE_CFLAGS_NODIST

     Value of *note CFLAGS_NODIST: 21c7. variable passed to the
     ‘./configure’ script.

     Added in version 3.5.

 -- Variabile d'ambiente: BASECFLAGS

     Base compiler flags.

 -- Variabile d'ambiente: OPT

     Optimization flags.

 -- Variabile d'ambiente: CFLAGS_ALIASING

     Strict or non-strict aliasing flags used to compile
     ‘Python/dtoa.c’.

     Added in version 3.7.

 -- Variabile d'ambiente: CCSHARED

     Compiler flags used to build a shared library.

     For example, ‘-fPIC’ is used on Linux and on BSD.

 -- Variabile d'ambiente: CFLAGSFORSHARED

     Extra C flags added for building the interpreter object files.

     Default: ‘$(CCSHARED)’ when *note -enable-shared: a65. is used, or
     an empty string otherwise.

 -- Variabile d'ambiente: PY_CFLAGS

     Default: ‘$(BASECFLAGS) $(OPT) $(CONFIGURE_CFLAGS) $(CFLAGS)
     $(EXTRA_CFLAGS)’.

 -- Variabile d'ambiente: PY_CFLAGS_NODIST

     Default: ‘$(CONFIGURE_CFLAGS_NODIST) $(CFLAGS_NODIST)
     -I$(srcdir)/Include/internal’.

     Added in version 3.5.

 -- Variabile d'ambiente: PY_STDMODULE_CFLAGS

     C flags used for building the interpreter object files.

     Default: ‘$(PY_CFLAGS) $(PY_CFLAGS_NODIST) $(PY_CPPFLAGS)
     $(CFLAGSFORSHARED)’.

     Added in version 3.7.

 -- Variabile d'ambiente: PY_CORE_CFLAGS

     Default: ‘$(PY_STDMODULE_CFLAGS) -DPy_BUILD_CORE’.

     Added in version 3.2.

 -- Variabile d'ambiente: PY_BUILTIN_MODULE_CFLAGS

     Compiler flags to build a standard library extension module as a
     built-in module, like the *note posix: b2. module.

     Default: ‘$(PY_STDMODULE_CFLAGS) -DPy_BUILD_CORE_BUILTIN’.

     Added in version 3.8.

 -- Variabile d'ambiente: PURIFY

     Purify command.  Purify is a memory debugger program.

     Default: empty string (not used).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/65320


File: python.info,  Node: Linker flags,  Prev: Compiler flags,  Up: Compiler and linker flags

3.3.5.3 Linker flags
....................

 -- Variabile d'ambiente: LINKCC

     Linker command used to build programs like ‘python’ and
     ‘_testembed’.

     Default: ‘$(PURIFY) $(CC)’.

 -- Variabile d'ambiente: CONFIGURE_LDFLAGS

     Value of *note LDFLAGS: 16bf. variable passed to the ‘./configure’
     script.

     Avoid assigning *note CFLAGS: 16be, *note LDFLAGS: 16bf, etc.  so
     users can use them on the command line to append to these values
     without stomping the pre-set values.

     Added in version 3.2.

 -- Variabile d'ambiente: LDFLAGS_NODIST

     *note LDFLAGS_NODIST: 21d9. is used in the same manner as *note
     CFLAGS_NODIST: 21c7.  Use it when a linker flag should 'not' be
     part of *note LDFLAGS: 16bf. once Python is installed
     (gh-65320(1)).

     In particular, *note LDFLAGS: 16bf. should not contain:

        * the compiler flag ‘-L’ (for setting the search path for
          libraries).  The ‘-L’ flags are processed from left to right,
          and any flags in *note LDFLAGS: 16bf. would take precedence
          over user- and package-supplied ‘-L’ flags.

 -- Variabile d'ambiente: CONFIGURE_LDFLAGS_NODIST

     Value of *note LDFLAGS_NODIST: 21d9. variable passed to the
     ‘./configure’ script.

     Added in version 3.8.

 -- Variabile d'ambiente: LDFLAGS

     Linker flags, e.g.  ‘-LLIB_DIR’ if you have libraries in a
     nonstandard directory 'lib_dir'.

     Both *note CPPFLAGS: 16c0. and *note LDFLAGS: 16bf. need to contain
     the shell’s value to be able to build extension modules using the
     directories specified in the environment variables.

 -- Variabile d'ambiente: LIBS

     Linker flags to pass libraries to the linker when linking the
     Python executable.

     Example: ‘-lrt’.

 -- Variabile d'ambiente: LDSHARED

     Command to build a shared library.

     Default: ‘@LDSHARED@ $(PY_LDFLAGS)’.

 -- Variabile d'ambiente: BLDSHARED

     Command to build ‘libpython’ shared library.

     Default: ‘@BLDSHARED@ $(PY_CORE_LDFLAGS)’.

 -- Variabile d'ambiente: PY_LDFLAGS

     Default: ‘$(CONFIGURE_LDFLAGS) $(LDFLAGS)’.

 -- Variabile d'ambiente: PY_LDFLAGS_NODIST

     Default: ‘$(CONFIGURE_LDFLAGS_NODIST) $(LDFLAGS_NODIST)’.

     Added in version 3.8.

 -- Variabile d'ambiente: PY_CORE_LDFLAGS

     Linker flags used for building the interpreter object files.

     Added in version 3.8.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/65320


File: python.info,  Node: Using Python on Windows,  Next: Using Python on macOS,  Prev: Configure Python,  Up: Python Setup and Usage

3.4 Using Python on Windows
===========================

This document aims to give an overview of Windows-specific behaviour you
should know about when using Python on Microsoft Windows.

Unlike most Unix systems and services, Windows does not include a system
supported installation of Python.  Instead, Python can be obtained from
a number of distributors, including directly from the CPython team.
Each Python distribution will have its own benefits and drawbacks,
however, consistency with other tools you are using is generally a
worthwhile benefit.  Before committing to the process described here, we
recommend investigating your existing tools to see if they can provide
Python directly.

To obtain Python from the CPython team, use the Python Install Manager.
This is a standalone tool that makes Python available as global commands
on your Windows machine, integrates with the system, and supports
updates over time.  You can download the Python Install Manager from
python.org/downloads(1) or through the Microsoft Store app(2).

Once you have installed the Python Install Manager, the global ‘python’
command can be used from any terminal to launch your current latest
version of Python.  This version may change over time as you add or
remove different versions, and the ‘py list’ command will show which is
current.

In general, we recommend that you create a *note virtual environment:
20d4. for each project and run ‘<env>\Scripts\Activate’ in your terminal
to use it.  This provides isolation between projects, consistency over
time, and ensures that additional commands added by packages are also
available in your session.  Create a virtual environment using ‘python
-m venv <env path>’.

If the ‘python’ or ‘py’ commands do not seem to be working, please see
the *note Troubleshooting: 21e4. section below.  There are sometimes
additional manual steps required to configure your PC.

Apart from using the Python install manager, Python can also be obtained
as NuGet packages.  See *note The nuget.org packages: 21e5. below for
more information on these packages.

The embeddable distros are minimal packages of Python suitable for
embedding into larger applications.  They can be installed using the
Python install manager.  See *note The embeddable package: 21e6. below
for more information on these packages.
* Menu:

* Python install manager::
* The embeddable package::
* The nuget.org packages: The nuget org packages.
* Alternative bundles::
* Supported Windows versions::
* Removing the MAX_PATH limitation::
* UTF-8 mode::
* Finding modules::
* Additional modules::
* Compiling Python on Windows::
* The full installer (deprecated): The full installer deprecated.
* Python launcher for Windows (deprecated): Python launcher for Windows deprecated.

   ---------- Footnotes ----------

   (1) https://www.python.org/downloads/

   (2) https://apps.microsoft.com/detail/9NQ7512CXL7T


File: python.info,  Node: Python install manager,  Next: The embeddable package,  Up: Using Python on Windows

3.4.1 Python install manager
----------------------------

* Menu:

* Installation::
* Basic use::
* Command help::
* Listing runtimes::
* Installing runtimes::
* Offline installs::
* Uninstalling runtimes::
* Configuration::
* Shebang lines::
* Advanced installation::
* Administrative configuration::
* Installing free-threaded binaries::
* Troubleshooting::


File: python.info,  Node: Installation,  Next: Basic use,  Up: Python install manager

3.4.1.1 Installation
....................

The Python install manager can be installed from the Microsoft Store
app(1) or downloaded and installed from python.org/downloads(2).  The
two versions are identical.

To install through the Store, simply click «Install».  After it has
completed, open a terminal and type ‘python’ to get started.

To install the file downloaded from python.org, either double-click and
select «Install», or run ‘Add-AppxPackage <path to MSIX>’ in Windows
Powershell.

After installation, the ‘python’, ‘py’, and ‘pymanager’ commands should
be available.  If you have existing installations of Python, or you have
modified your ‘PATH’ variable, you may need to remove them or undo the
modifications.  See *note Troubleshooting: 21e4. for more help with
fixing non-working commands.

When you first install a runtime, you will likely be prompted to add a
directory to your ‘PATH’.  This is optional, if you prefer to use the
‘py’ command, but is offered for those who prefer the full range of
aliases (such as ‘python3.14.exe’) to be available.  The directory will
be ‘%LocalAppData%\Python\bin’ by default, but may be customized by an
administrator.  Click Start and search for «Edit environment variables
for your account» for the system settings page to add the path.

Each Python runtime you install will have its own directory for scripts.
These also need to be added to ‘PATH’ if you want to use them.

The Python install manager will be automatically updated to new
releases.  This does not affect any installs of Python runtimes.
Uninstalling the Python install manager does not uninstall any Python
runtimes.

If you are not able to install an MSIX in your context, for example, you
are using automated deployment software that does not support it, or are
targeting Windows Server 2019, please see *note Advanced installation:
21ea. below for more information.

   ---------- Footnotes ----------

   (1) https://apps.microsoft.com/detail/9NQ7512CXL7T

   (2) https://www.python.org/downloads/


File: python.info,  Node: Basic use,  Next: Command help,  Prev: Installation,  Up: Python install manager

3.4.1.2 Basic use
.................

The recommended command for launching Python is ‘python’, which will
either launch the version requested by the script being launched, an
active virtual environment, or the default installed version, which will
be the latest stable release unless configured otherwise.  If no version
is specifically requested and no runtimes are installed at all, the
current latest release will be installed automatically.

For all scenarios involving multiple runtime versions, the recommended
command is ‘py’.  This may be used anywhere in place of ‘python’ or the
older ‘py.exe’ launcher.  By default, ‘py’ matches the behaviour of
‘python’, but also allows command line options to select a specific
version as well as subcommands to manage installations.  These are
detailed below.

Because the ‘py’ command may already be taken by the previous version,
there is also an unambiguous ‘pymanager’ command.  Scripted installs
that are intending to use Python install manager should consider using
‘pymanager’, due to the lower chance of encountering a conflict with
existing installs.  The only difference between the two commands is when
running without any arguments: ‘py’ will launch your default
interpreter, while ‘pymanager’ will display help (‘pymanager exec ...’
provides equivalent behaviour to ‘py ...’).

Each of these commands also has a windowed version that avoids creating
a console window.  These are ‘pyw’, ‘pythonw’ and ‘pymanagerw’.  A
‘python3’ command is also included that mimics the ‘python’ command.  It
is intended to catch accidental uses of the typical POSIX command on
Windows, but is not meant to be widely used or recommended.

To launch your default runtime, run ‘python’ or ‘py’ with the arguments
you want to be passed to the runtime (such as script files or the module
to launch):

     $> py
     ...
     $> python my-script.py
     ...
     $> py -m this
     ...

The default runtime can be overridden with the *note
PYTHON_MANAGER_DEFAULT: 21ec. environment variable, or a configuration
file.  See *note Configuration: 21ed. for information about
configuration settings.

To launch a specific runtime, the ‘py’ command accepts a ‘-V:<TAG>’
option.  This option must be specified before any others.  The tag is
part or all of the identifier for the runtime; for those from the
CPython team, it looks like the version, potentially with the platform.
For compatibility, the ‘V:’ may be omitted in cases where the tag refers
to an official release and starts with ‘3’.

     $> py -V:3.14 ...
     $> py -V:3-arm64 ...

Runtimes from other distributors may require the 'company' to be
included as well.  This should be separated from the tag by a slash, and
may be a prefix.  Specifying the company is optional when it is
‘PythonCore’, and specifying the tag is optional (but not the slash)
when you want the latest release from a specific company.

     $> py -V:Distributor\1.0 ...
     $> py -V:distrib/ ...

If no version is specified, but a script file is passed, the script will
be inspected for a 'shebang line'.  This is a special format for the
first line in a file that allows overriding the command.  See *note
Shebang lines: 21ee. for more information.  When there is no shebang
line, or it cannot be resolved, the script will be launched with the
default runtime.

If you are running in an active virtual environment, have not requested
a particular version, and there is no shebang line, the default runtime
will be that virtual environment.  In this scenario, the ‘python’
command was likely already overridden and none of these checks occurred.
However, this behaviour ensures that the ‘py’ command can be used
interchangeably.

When no runtimes are installed, any launch command will try to install
the requested version and launch it.  However, after any version is
installed, only the ‘py exec ...’ and ‘pymanager exec ...’ commands will
install if the requested version is absent.  Other forms of commands
will display an error and direct you to use ‘py install’ first.


File: python.info,  Node: Command help,  Next: Listing runtimes,  Prev: Basic use,  Up: Python install manager

3.4.1.3 Command help
....................

The ‘py help’ command will display the full list of supported commands,
along with their options.  Any command may be passed the ‘-?’ option to
display its help, or its name passed to ‘py help’.

     $> py help
     $> py help install
     $> py install /?

All commands support some common options, which will be shown by ‘py
help’.  These options must be specified after any subcommand.
Specifying ‘-v’ or ‘--verbose’ will increase the amount of output shown,
and ‘-vv’ will increase it further for debugging purposes.  Passing ‘-q’
or ‘--quiet’ will reduce output, and ‘-qq’ will reduce it further.

The ‘--config=<PATH>’ option allows specifying a configuration file to
override multiple settings at once.  See *note Configuration: 21ed.
below for more information about these files.


File: python.info,  Node: Listing runtimes,  Next: Installing runtimes,  Prev: Command help,  Up: Python install manager

3.4.1.4 Listing runtimes
........................

     $> py list [-f=|--format=<FMT>] [-1|--one] [--online|-s=|--source=<URL>] [<TAG>...]

The list of installed runtimes can be seen using ‘py list’.  A filter
may be added in the form of one or more tags (with or without company
specifier), and each may include a ‘<’, ‘<=’, ‘>=’ or ‘>’ prefix to
restrict to a range.

A range of formats are supported, and can be passed as the
‘--format=<FMT>’ or ‘-f <FMT>’ option.  Formats include ‘table’ (a user
friendly table view), ‘csv’ (comma-separated table), ‘json’ (a single
JSON blob), ‘jsonl’ (one JSON blob per result), ‘exe’ (just the
executable path), ‘prefix’ (just the prefix path).

The ‘--one’ or ‘-1’ option only displays a single result.  If the
default runtime is included, it will be the one.  Otherwise, the «best»
result is shown («best» is deliberately vaguely defined, but will
usually be the most recent version).  The result shown by ‘py list --one
<TAG>’ will match the runtime that would be launched by ‘py -V:<TAG>’.

The ‘--only-managed’ option excludes results that were not installed by
the Python install manager.  This is useful when determining which
runtimes may be updated or uninstalled through the ‘py’ command.

The ‘--online’ option is short for passing ‘--source=<URL>’ with the
default source.  Passing either of these options will search the online
index for runtimes that can be installed.  The result shown by ‘py list
--online --one <TAG>’ will match the runtime that would be installed by
‘py install <TAG>’.

     $> py list --online 3.14

For compatibility with the old launcher, the ‘--list’, ‘--list-paths’,
‘-0’ and ‘-0p’ commands (e.g.  ‘py -0p’) are retained.  They do not
allow additional options, and will produce legacy formatted output.


File: python.info,  Node: Installing runtimes,  Next: Offline installs,  Prev: Listing runtimes,  Up: Python install manager

3.4.1.5 Installing runtimes
...........................

     $> py install [-s=|--source=<URL>] [-f|--force] [-u|--update] [--dry-run] [<TAG>...]

New runtime versions may be added using ‘py install’.  One or more tags
may be specified, and the special tag ‘default’ may be used to select
the default.  Ranges are not supported for installation.

The ‘--source=<URL>’ option allows overriding the online index that is
used to obtain runtimes.  This may be used with an offline index, as
shown in *note Offline installs: 21f2.

Passing ‘--force’ will ignore any cached files and remove any existing
install to replace it with the specified one.

Passing ‘--update’ will replace existing installs if the new version is
newer.  Otherwise, they will be left.  If no tags are provided with
‘--update’, all installs managed by the Python install manager will be
updated if newer versions are available.  Updates will remove any
modifications made to the install, including globally installed
packages, but virtual environments will continue to work.

Passing ‘--dry-run’ will generate output and logs, but will not modify
any installs.

In addition to the above options, the ‘--target’ option will extract the
runtime to the specified directory instead of doing a normal install.
This is useful for embedding runtimes into larger applications.  Unlike
a normal install, ‘py’ will not be aware of the extracted runtime, and
no Start menu or other shortcuts will be created.  To launch the
runtime, directly execute the main executable (typically ‘python.exe’)
in the target directory.

     $> py install ... [-t=|--target=<PATH>] <TAG>

The ‘py exec’ command will install the requested runtime if it is not
already present.  This is controlled by the ‘automatic_install’
configuration ( *note PYTHON_MANAGER_AUTOMATIC_INSTALL: 21f3.), and is
enabled by default.  If no runtimes are available at all, all launch
commands will do an automatic install if the configuration setting
allows.  This is to ensure a good experience for new users, but should
not generally be relied on rather than using the ‘py exec’ command or
explicit install commands.


File: python.info,  Node: Offline installs,  Next: Uninstalling runtimes,  Prev: Installing runtimes,  Up: Python install manager

3.4.1.6 Offline installs
........................

To perform offline installs of Python, you will need to first create an
offline index on a machine that has network access.

     $> py install --download=<PATH> ... <TAG>...

The ‘--download=<PATH>’ option will download the packages for the listed
tags and create a directory containing them and an ‘index.json’ file
suitable for later installation.  This entire directory can be moved to
the offline machine and used to install one or more of the bundled
runtimes:

     $> py install --source="<PATH>\index.json" <TAG>...

The Python install manager can be installed by downloading its installer
and moving it to another machine before installing.

Alternatively, the ZIP files in an offline index directory can simply be
transferred to another machine and extracted.  This will not register
the install in any way, and so it must be launched by directly
referencing the executables in the extracted directory, but it is
sometimes a preferable approach in cases where installing the Python
install manager is not possible or convenient.

In this way, Python runtimes can be installed and managed on a machine
without access to the internet.


File: python.info,  Node: Uninstalling runtimes,  Next: Configuration,  Prev: Offline installs,  Up: Python install manager

3.4.1.7 Uninstalling runtimes
.............................

     $> py uninstall [-y|--yes] <TAG>...

Runtimes may be removed using the ‘py uninstall’ command.  One or more
tags must be specified.  Ranges are not supported here.

The ‘--yes’ option bypasses the confirmation prompt before uninstalling.

Instead of passing tags individually, the ‘--purge’ option may be
specified.  This will remove all runtimes managed by the Python install
manager, including cleaning up the Start menu, registry, and any
download caches.  Runtimes that were not installed by the Python install
manager will not be impacted, and neither will manually created
configuration files.

     $> py uninstall [-y|--yes] --purge

The Python install manager can be uninstalled through the Windows
«Installed apps» settings page.  This does not remove any runtimes, and
they will still be usable, though the global ‘python’ and ‘py’ commands
will be removed.  Reinstalling the Python install manager will allow you
to manage these runtimes again.  To completely clean up all Python
runtimes, run with ‘--purge’ before uninstalling the Python install
manager.


File: python.info,  Node: Configuration,  Next: Shebang lines,  Prev: Uninstalling runtimes,  Up: Python install manager

3.4.1.8 Configuration
.....................

Python install manager is configured with a hierarchy of configuration
files, environment variables, command-line options, and registry
settings.  In general, configuration files have the ability to configure
everything, including the location of other configuration files, while
registry settings are administrator-only and will override configuration
files.  Command-line options override all other settings, but not every
option is available.

This section will describe the defaults, but be aware that modified or
overridden installs may resolve settings differently.

A global configuration file may be configured by an administrator, and
would be read first.  The user configuration file is stored at
‘%AppData%\Python\pymanager.json’ (note that this location is under
‘Roaming’, not ‘Local’) and is read next, overwriting any settings from
earlier files.  An additional configuration file may be specified as the
‘PYTHON_MANAGER_CONFIG’ environment variable or the ‘--config’ command
line option (but not both).  These locations may be modified by
administrative customization options listed later.

The following settings are those that are considered likely to be
modified in normal use.  Later sections list those that are intended for
administrative customization.

Standard configuration options
..............................

Config Key                            Environment Variable                  Description
                                                                            
------------------------------------------------------------------------------------------------------------------
                                                                            
‘default_tag’                          -- Variabile d'ambiente:             The preferred default version to
                                                PYTHON_MANAGER_DEFAULT      launch or install.  By default,
                                                                            this is interpreted as the most
                                                                            recent non-prerelease version from
                                                                            the CPython team.
                                                                            
                                                                            
‘default_platform’                    ‘PYTHON_MANAGER_DEFAULT_PLATFORM’     The preferred default platform to
                                                                            launch or install.  This is treated
                                                                            as a suffix to the specified tag,
                                                                            such that ‘py -V:3.14’ would prefer
                                                                            an install for ‘3.14-64’ if it
                                                                            exists (and ‘default_platform’ is
                                                                            ‘-64’), but will use ‘3.14’ if no
                                                                            tagged install exists.
                                                                            
                                                                            
‘logs_dir’                            ‘PYTHON_MANAGER_LOGS’                 The location where log files are
                                                                            written.  By default, ‘%TEMP%’.
                                                                            
                                                                            
‘automatic_install’                    -- Variabile d'ambiente:             True to allow automatic installs
                                                PYTHON_MANAGER_AUTOMATIC_INSTALLwhen using ‘py exec’ to launch (or
                                                                            ‘py’ when no runtimes are installed
                                                                            yet).  Other commands will not
                                                                            automatically install, regardless
                                                                            of this setting.  By default, true.
                                                                            
                                                                            
‘include_unmanaged’                   ‘PYTHON_MANAGER_INCLUDE_UNMANAGED’    True to allow listing and launching
                                                                            runtimes that were not installed by
                                                                            the Python install manager, or
                                                                            false to exclude them.  By default,
                                                                            true.
                                                                            
                                                                            
‘shebang_can_run_anything’            ‘PYTHON_MANAGER_SHEBANG_CAN_RUN_ANYTHING’True to allow shebangs in ‘.py’
                                                                            files to launch applications other
                                                                            than Python runtimes, or false to
                                                                            prevent it.  By default, true.
                                                                            
                                                                            
‘log_level’                           ‘PYMANAGER_VERBOSE’,                  Set the default level of output
                                      ‘PYMANAGER_DEBUG’                     (0-50).  By default, 20.  Lower
                                                                            values produce more output.  The
                                                                            environment variables are boolean,
                                                                            and may produce additional output
                                                                            during startup that is later
                                                                            suppressed by other configuration.
                                                                            
                                                                            
‘confirm’                             ‘PYTHON_MANAGER_CONFIRM’              True to confirm certain actions
                                                                            before taking them (such as
                                                                            uninstall), or false to skip the
                                                                            confirmation.  By default, true.
                                                                            
                                                                            
‘install.source’                      ‘PYTHON_MANAGER_SOURCE_URL’           Override the index feed to obtain
                                                                            new installs from.
                                                                            
                                                                            
‘list.format’                         ‘PYTHON_MANAGER_LIST_FORMAT’          Specify the default format used by
                                                                            the ‘py list’ command.  By default,
                                                                            ‘table’.
                                                                            
                                                                            
‘install_dir’                         (none)                                Specify the root directory that
                                                                            runtimes will be installed into.
                                                                            If you change this setting,
                                                                            previously installed runtimes will
                                                                            not be usable unless you move them
                                                                            to the new location.
                                                                            
                                                                            
‘global_dir’                          (none)                                Specify the directory where global
                                                                            commands (such as ‘python3.14.exe’)
                                                                            are stored.  This directory should
                                                                            be added to your ‘PATH’ to make the
                                                                            commands available from your
                                                                            terminal.
                                                                            
                                                                            
‘download_dir’                        (none)                                Specify the directory where
                                                                            downloaded files are stored.  This
                                                                            directory is a temporary cache, and
                                                                            can be cleaned up from time to
                                                                            time.
                                                                            

Dotted names should be nested inside JSON objects, for example,
‘list.format’ would be specified as ‘{"list": {"format": "table"}}’.


File: python.info,  Node: Shebang lines,  Next: Advanced installation,  Prev: Configuration,  Up: Python install manager

3.4.1.9 Shebang lines
.....................

If the first line of a script file starts with ‘#!’, it is known as a
«shebang» line.  Linux and other Unix like operating systems have native
support for such lines and they are commonly used on such systems to
indicate how a script should be executed.  The ‘python’ and ‘py’
commands allow the same facilities to be used with Python scripts on
Windows.

To allow shebang lines in Python scripts to be portable between Unix and
Windows, a number of “virtual” commands are supported to specify which
interpreter to use.  The supported virtual commands are:

   * ‘/usr/bin/env <ALIAS>’

   * ‘/usr/bin/env -S <ALIAS>’

   * ‘/usr/bin/<ALIAS>’

   * ‘/usr/local/bin/<ALIAS>’

   * ‘<ALIAS>’

For example, if the first line of your script starts with

     #! /usr/bin/python

The default Python or an active virtual environment will be located and
used.  As many Python scripts written to work on Unix will already have
this line, you should find these scripts can be used by the launcher
without modification.  If you are writing a new script on Windows which
you hope will be useful on Unix, you should use one of the shebang lines
starting with ‘/usr’.

Any of the above virtual commands can have ‘<ALIAS>’ replaced by an
alias from an installed runtime.  That is, any command generated in the
global aliases directory (which you may have added to your ‘PATH’
environment variable) can be used in a shebang, even if it is not on
your ‘PATH’.  This allows the use of shebangs like ‘/usr/bin/python3.12’
to select a particular runtime.

If no runtimes are installed, or if automatic installation is enabled,
the requested runtime will be installed if necessary.  See *note
Configuration: 21ed. for information about configuration settings.

The ‘/usr/bin/env’ form of shebang line will also search the ‘PATH’
environment variable for unrecognized commands.  This corresponds to the
behaviour of the Unix ‘env’ program, which performs the same search, but
prefers launching known Python commands.  A warning may be displayed
when searching for arbitrary executables, and this search may be
disabled by the ‘shebang_can_run_anything’ configuration option.

Shebang lines that do not match any of patterns are treated as 'Windows'
executable paths that are absolute or relative to the directory
containing the script file.  This is a convenience for Windows-only
scripts, such as those generated by an installer, since the behavior is
not compatible with Unix-style shells.  These paths may be quoted, and
may include multiple arguments, after which the path to the script and
any additional arguments will be appended.  This functionality may be
disabled by the ‘shebang_can_run_anything’ configuration option.

     Nota: The behaviour of shebangs in the Python install manager is
     subtly different from the previous ‘py.exe’ launcher, and the old
     configuration options no longer apply.  If you are specifically
     reliant on the old behaviour or configuration, we recommend
     installing the legacy launcher(1).  The legacy launcher’s ‘py’
     command will override PyManager’s one by default, and you will need
     to use ‘pymanager’ commands for installing and uninstalling.

   ---------- Footnotes ----------

   (1) https://www.python.org/ftp/python/3.14.0/win32/launcher.msi


File: python.info,  Node: Advanced installation,  Next: Administrative configuration,  Prev: Shebang lines,  Up: Python install manager

3.4.1.10 Advanced installation
..............................

For situations where an MSIX cannot be installed, such as some older
administrative distribution platforms, there is an MSI available from
the python.org downloads page.  This MSI has no user interface, and can
only perform per-machine installs to its default location in Program
Files.  It will attempt to modify the system ‘PATH’ environment variable
to include this install location, but be sure to validate this on your
configuration.

     Nota: Windows Server 2019 is the only version of Windows that
     CPython supports that does not support MSIX. For Windows Server
     2019, you should use the MSI.

Be aware that the MSI package does not bundle any runtimes, and so is
not suitable for installs into offline environments without also
creating an offline install index.  See *note Offline installs: 21f2.
and *note Administrative configuration: 21f9. for information on
handling these scenarios.

Runtimes installed by the MSI are shared with those installed by the
MSIX, and are all per-user only.  The Python install manager does not
support installing runtimes per-machine.  To emulate a per-machine
install, you can use ‘py install --target=<shared location>’ as
administrator and add your own system-wide modifications to ‘PATH’, the
registry, or the Start menu.

When the MSIX is installed, but commands are not available in the ‘PATH’
environment variable, they can be found under
‘%LocalAppData%\Microsoft\WindowsApps\PythonSoftwareFoundation.PythonManager_3847v3x7pw1km’
or
‘%LocalAppData%\Microsoft\WindowsApps\PythonSoftwareFoundation.PythonManager_qbz5n2kfra8p0’,
depending on whether it was installed from python.org or through the
Windows Store.  Attempting to run the executable directly from Program
Files is not recommended.

To programmatically install the Python install manager, it is easiest to
use WinGet, which is included with all supported versions of Windows:

     $> winget install 9NQ7512CXL7T -e --accept-package-agreements --disable-interactivity

     # Optionally run the configuration checker and accept all changes
     $> py install --configure -y

To download the Python install manager and install on another machine,
the following WinGet command will download the required files from the
Store to your Downloads directory (add ‘-d <location>’ to customize the
output location).  This also generates a YAML file that appears to be
unnecessary, as the downloaded MSIX can be installed by launching or
using the commands below.

     $> winget download 9NQ7512CXL7T -e --skip-license --accept-package-agreements --accept-source-agreements

To programmatically install or uninstall an MSIX using only PowerShell,
the Add-AppxPackage(1) and Remove-AppxPackage(2) PowerShell cmdlets are
recommended:

     $> Add-AppxPackage C:\Downloads\python-manager-25.0.msix
     ...
     $> Get-AppxPackage PythonSoftwareFoundation.PythonManager | Remove-AppxPackage

The latest release can be downloaded and installed by Windows by passing
the AppInstaller file to the Add-AppxPackage command.  This installs
using the MSIX on python.org, and is only recommended for cases where
installing via the Store (interactively or using WinGet) is not
possible.

     $> Add-AppxPackage -AppInstallerFile https://www.python.org/ftp/python/pymanager/pymanager.appinstaller

Other tools and APIs may also be used to provision an MSIX package for
all users on a machine, but Python does not consider this a supported
scenario.  We suggest looking into the PowerShell
Add-AppxProvisionedPackage(3) cmdlet, the native Windows
PackageManager(4) class, or the documentation and support for your
deployment tool.

Regardless of the install method, users will still need to install their
own copies of Python itself, as there is no way to trigger those
installs without being a logged in user.  When using the MSIX, the
latest version of Python will be available for all users to install
without network access.

Note that the MSIX downloadable from the Store and from the Python
website are subtly different and cannot be installed at the same time.
Wherever possible, we suggest using the above WinGet commands to
download the package from the Store to reduce the risk of setting up
conflicting installs.  There are no licensing restrictions on the Python
install manager that would prevent using the Store package in this way.

   ---------- Footnotes ----------

   (1) 
https://learn.microsoft.com/powershell/module/appx/add-appxpackage

   (2) 
https://learn.microsoft.com/powershell/module/appx/remove-appxpackage

   (3) 
https://learn.microsoft.com/powershell/module/dism/add-appxprovisionedpackage

   (4) 
https://learn.microsoft.com/uwp/api/windows.management.deployment.packagemanager


File: python.info,  Node: Administrative configuration,  Next: Installing free-threaded binaries,  Prev: Advanced installation,  Up: Python install manager

3.4.1.11 Administrative configuration
.....................................

There are a number of options that may be useful for administrators to
override configuration of the Python install manager.  These can be used
to provide local caching, disable certain shortcut types, override
bundled content.  All of the above configuration options may be set, as
well as those below.

Configuration options may be overridden in the registry by setting
values under ‘HKEY_LOCAL_MACHINE\Software\Policies\Python\PyManager’,
where the value name matches the configuration key and the value type is
‘REG_SZ’.  Note that this key can itself be customized, but only by
modifying the core config file distributed with the Python install
manager.  We recommend, however, that registry values are used only to
set ‘base_config’ to a JSON file containing the full set of overrides.
Registry key overrides will replace any other configured setting, while
‘base_config’ allows users to further modify settings they may need.

Note that most settings with environment variables support those
variables because their default setting specifies the variable.  If you
override them, the environment variable will no longer work, unless you
override it with another one.  For example, the default value of
‘confirm’ is literally ‘%PYTHON_MANAGER_CONFIRM%’, which will resolve
the variable at load time.  If you override the value to ‘yes’, then the
environment variable will no longer be used.  If you override the value
to ‘%CONFIRM%’, then that environment variable will be used instead.

Configuration settings that are paths are interpreted as relative to the
directory containing the configuration file that specified them.

Administrative configuration options
....................................

Config Key                                             Description
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
‘base_config’                                          The highest priority configuration file to read.
                                                       Note that only the built-in configuration file and
                                                       the registry can modify this setting.
                                                       
                                                       
‘user_config’                                          The second configuration file to read.
                                                       
                                                       
‘additional_config’                                    The third configuration file to read.
                                                       
                                                       
‘registry_override_key’                                Registry location to check for overrides.  Note that
                                                       only the built-in configuration file can modify this
                                                       setting.
                                                       
                                                       
‘bundled_dir’                                          Read-only directory containing locally cached files.
                                                       
                                                       
‘install.fallback_source’                              Path or URL to an index to consult when the main
                                                       index cannot be accessed.
                                                       
                                                       
‘install.enable_shortcut_kinds’                        Comma-separated list of shortcut kinds to allow
                                                       (e.g.  ‘"pep514,start"’).  Enabled shortcuts may
                                                       still be disabled by ‘disable_shortcut_kinds’.
                                                       
                                                       
‘install.disable_shortcut_kinds’                       Comma-separated list of shortcut kinds to exclude
                                                       (e.g.  ‘"pep514,start"’).  Disabled shortcuts are
                                                       not reactivated by ‘enable_shortcut_kinds’.
                                                       
                                                       
‘pep514_root’                                          Registry location to read and write PEP 514 entries
                                                       into.  By default,
                                                       ‘HKEY_CURRENT_USER\Software\Python’.
                                                       
                                                       
‘start_folder’                                         Start menu folder to write shortcuts into.  By
                                                       default, ‘Python’.  This path is relative to the
                                                       user’s Programs folder.
                                                       
                                                       
‘virtual_env’                                          Path to the active virtual environment.  By default,
                                                       this is ‘%VIRTUAL_ENV%’, but may be set empty to
                                                       disable venv detection.
                                                       
                                                       
‘shebang_can_run_anything_silently’                    True to suppress visible warnings when a shebang
                                                       launches an application other than a Python runtime.
                                                       


File: python.info,  Node: Installing free-threaded binaries,  Next: Troubleshooting,  Prev: Administrative configuration,  Up: Python install manager

3.4.1.12 Installing free-threaded binaries
..........................................

Added in version 3.13.

Pre-built distributions of the free-threaded build are available by
installing tags with the ‘t’ suffix.

     $> py install 3.14t
     $> py install 3.14t-arm64
     $> py install 3.14t-32

This will install and register as normal.  If you have no other runtimes
installed, then ‘python’ will launch this one.  Otherwise, you will need
to use ‘py -V:3.14t ...’ or, if you have added the global aliases
directory to your ‘PATH’ environment variable, the ‘python3.14t.exe’
commands.


File: python.info,  Node: Troubleshooting,  Prev: Installing free-threaded binaries,  Up: Python install manager

3.4.1.13 Troubleshooting
........................

If your Python install manager does not seem to be working correctly,
please work through these tests and fixes to see if it helps.  If not,
please report an issue at our bug tracker(1), including any relevant log
files (written to your ‘%TEMP%’ directory by default).

Troubleshooting
...............

Symptom                                                Things to try
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
‘python’ gives me a «command not found» error or       Did you
opens the Store app when I type it in my terminal.     *note install the Python install manager: 21e7.?
                                                       
                                                       
                                                       Click Start, open «Manage app execution aliases»,
                                                       and check that the aliases for «Python (default)»
                                                       are enabled.  If they already are, try disabling and
                                                       re-enabling to refresh the command.  The «Python
                                                       (default windowed)» and «Python install manager»
                                                       commands may also need refreshing.
                                                       
                                                       
                                                       Check that the ‘py’ and ‘pymanager’ commands work.
                                                       
                                                       
                                                       Ensure your ‘PATH’ variable contains the entry for
                                                       ‘%UserProfile%\AppData\Local\Microsoft\WindowsApps’.
                                                       The operating system includes this entry once by
                                                       default, after other user paths.  If removed,
                                                       shortcuts will not be found.
                                                       
                                                       
‘py’ gives me a «command not found» error when I       Did you
type it in my terminal.                                *note install the Python install manager: 21e7.?
                                                       
                                                       
                                                       Click Start, open «Manage app execution aliases»,
                                                       and check that the aliases for «Python (default)»
                                                       are enabled.  If they already are, try disabling and
                                                       re-enabling to refresh the command.  The «Python
                                                       (default windowed)» and «Python install manager»
                                                       commands may also need refreshing.
                                                       
                                                       
                                                       Ensure your ‘PATH’ variable contains the entry for
                                                       ‘%UserProfile%\AppData\Local\Microsoft\WindowsApps’.
                                                       The operating system includes this entry once by
                                                       default, after other user paths.  If removed,
                                                       shortcuts will not be found.
                                                       
                                                       
‘py’ gives me a «can’t open file» error when I type    This usually means you have the legacy launcher
commands in my terminal.                               installed and it has priority over the Python
                                                       install manager.  To remove, click Start, open
                                                       «Installed apps», search for «Python launcher» and
                                                       uninstall it.
                                                       
                                                       
‘python’ doesn’t launch the same runtime as ‘py’       Click Start, open «Installed apps», look for any
                                                       existing Python runtimes, and either remove them or
                                                       Modify and disable the ‘PATH’ options.
                                                       
                                                       
                                                       Click Start, open «Manage app execution aliases»,
                                                       and check that your ‘python.exe’ alias is set to
                                                       «Python (default)»
                                                       
                                                       
‘python’ and ‘py’ don’t launch the runtime I expect    Check your *note PYTHON_MANAGER_DEFAULT: 21ec.
                                                       environment variable or ‘default_tag’ configuration.
                                                       The ‘py list’ command will show your default based
                                                       on these settings.
                                                       
                                                       
                                                       Installs that are managed by the Python install
                                                       manager will be chosen ahead of unmanaged installs.
                                                       Use ‘py install’ to install the runtime you expect,
                                                       or configure your default tag.
                                                       
                                                       
                                                       Prerelease and experimental installs that are not
                                                       managed by the Python install manager may be chosen
                                                       ahead of stable releases.  Configure your default
                                                       tag or uninstall the prerelease runtime and
                                                       reinstall it using ‘py install’.
                                                       
                                                       
‘pythonw’ or ‘pyw’ don’t launch the same runtime as    Click Start, open «Manage app execution aliases»,
‘python’ or ‘py’                                       and check that your ‘pythonw.exe’ and ‘pyw.exe’
                                                       aliases are consistent with your others.
                                                       
                                                       
‘pip’ gives me a «command not found» error when I      Have you activated a virtual environment?  Run the
type it in my terminal.                                ‘.venv\Scripts\activate’ script in your terminal to
                                                       activate.
                                                       
                                                       
                                                       The package may be available but missing the
                                                       generated executable.  We recommend using the
                                                       ‘python -m pip’ command instead, or alternatively
                                                       the ‘python -m pip install --force pip’ command will
                                                       recreate the executables and show you the path to
                                                       add to ‘PATH’.  These scripts are separated for each
                                                       runtime, and so you may need to add multiple paths.
                                                       
                                                       
Typing ‘script-name.py’ in the terminal opens in a     This is a known limitation of the operating system.
new window.                                            Either specify ‘py’ before the script name, create a
                                                       batch file containing ‘@py "%~dpn0.py" %*’ with the
                                                       same name as the script, or install the legacy
                                                       launcher(2) and select it as the association for
                                                       scripts.
                                                       
                                                       
Drag-dropping files onto a script doesn’t work         This is a known limitation of the operating system.
                                                       It is supported with the legacy launcher(3), or with
                                                       the Python install manager when installed from the
                                                       MSI.
                                                       
                                                       
I have installed the Python install manager multiple   It is possible to install from the Store or WinGet,
times.                                                 from the MSIX on the Python website, and from the
                                                       MSI, all at once.  They are all compatible and will
                                                       share configuration and runtimes.
                                                       
                                                       
                                                       See the earlier *note Advanced installation: 21ea.
                                                       section for ways to uninstall the install manager
                                                       other than the typical Installed Apps (Add and
                                                       Remove Programs) settings page.
                                                       
                                                       
My old ‘py.ini’ settings no longer work.               The new Python install manager no longer supports
                                                       this configuration file or its settings, and so it
                                                       will be ignored.  See *note Configuration: 21ed. for
                                                       information about configuration settings.
                                                       

   ---------- Footnotes ----------

   (1) https://github.com/python/pymanager/issues

   (2) https://www.python.org/ftp/python/3.14.0/win32/launcher.msi

   (3) https://www.python.org/ftp/python/3.14.0/win32/launcher.msi


File: python.info,  Node: The embeddable package,  Next: The nuget org packages,  Prev: Python install manager,  Up: Using Python on Windows

3.4.2 The embeddable package
----------------------------

Added in version 3.5.

The embedded distribution is a ZIP file containing a minimal Python
environment.  It is intended for acting as part of another application,
rather than being directly accessed by end-users.

To install an embedded distribution, we recommend using ‘py install’
with the ‘--target’ option:

     $> py install 3.14-embed --target=<directory>

When extracted, the embedded distribution is (almost) fully isolated
from the user’s system, including environment variables, system registry
settings, and installed packages.  The standard library is included as
pre-compiled and optimized ‘.pyc’ files in a ZIP, and ‘python3.dll’,
‘python313.dll’, ‘python.exe’ and ‘pythonw.exe’ are all provided.
Tcl/tk (including all dependents, such as Idle), pip and the Python
documentation are not included.

A default ‘._pth’ file is included, which further restricts the default
search paths (as described below in *note Finding modules: e1c.).  This
file is intended for embedders to modify as necessary.

Third-party packages should be installed by the application installer
alongside the embedded distribution.  Using pip to manage dependencies
as for a regular Python installation is not supported with this
distribution, though with some care it may be possible to include and
use pip for automatic updates.  In general, third-party packages should
be treated as part of the application («vendoring») so that the
developer can ensure compatibility with newer versions before providing
updates to users.

The two recommended use cases for this distribution are described below.

* Menu:

* Python application::
* Embedding Python::


File: python.info,  Node: Python application,  Next: Embedding Python,  Up: The embeddable package

3.4.2.1 Python application
..........................

An application written in Python does not necessarily require users to
be aware of that fact.  The embedded distribution may be used in this
case to include a private version of Python in an install package.
Depending on how transparent it should be (or conversely, how
professional it should appear), there are two options.

Using a specialized executable as a launcher requires some coding, but
provides the most transparent experience for users.  With a customized
launcher, there are no obvious indications that the program is running
on Python: icons can be customized, company and version information can
be specified, and file associations behave properly.  In most cases, a
custom launcher should simply be able to call ‘Py_Main’ with a
hard-coded command line.

The simpler approach is to provide a batch file or generated shortcut
that directly calls the ‘python.exe’ or ‘pythonw.exe’ with the required
command-line arguments.  In this case, the application will appear to be
Python and not its actual name, and users may have trouble
distinguishing it from other running Python processes or file
associations.

With the latter approach, packages should be installed as directories
alongside the Python executable to ensure they are available on the
path.  With the specialized launcher, packages can be located in other
locations as there is an opportunity to specify the search path before
launching the application.


File: python.info,  Node: Embedding Python,  Prev: Python application,  Up: The embeddable package

3.4.2.2 Embedding Python
........................

Applications written in native code often require some form of scripting
language, and the embedded Python distribution can be used for this
purpose.  In general, the majority of the application is in native code,
and some part will either invoke ‘python.exe’ or directly use
‘python3.dll’.  For either case, extracting the embedded distribution to
a subdirectory of the application installation is sufficient to provide
a loadable Python interpreter.

As with the application use, packages can be installed to any location
as there is an opportunity to specify search paths before initializing
the interpreter.  Otherwise, there is no fundamental differences between
using the embedded distribution and a regular installation.


File: python.info,  Node: The nuget org packages,  Next: Alternative bundles,  Prev: The embeddable package,  Up: Using Python on Windows

3.4.3 The nuget.org packages
----------------------------

Added in version 3.5.2.

The nuget.org package is a reduced size Python environment intended for
use on continuous integration and build systems that do not have a
system-wide install of Python.  While nuget is «the package manager for
.NET», it also works perfectly fine for packages containing build-time
tools.

Visit nuget.org(1) for the most up-to-date information on using nuget.
What follows is a summary that is sufficient for Python developers.

The ‘nuget.exe’ command line tool may be downloaded directly from
‘https://aka.ms/nugetclidl’, for example, using curl or PowerShell.
With the tool, the latest version of Python for 64-bit or 32-bit
machines is installed using:

     nuget.exe install python -ExcludeVersion -OutputDirectory .
     nuget.exe install pythonx86 -ExcludeVersion -OutputDirectory .

To select a particular version, add a ‘-Version 3.x.y’.  The output
directory may be changed from ‘.’, and the package will be installed
into a subdirectory.  By default, the subdirectory is named the same as
the package, and without the ‘-ExcludeVersion’ option this name will
include the specific version installed.  Inside the subdirectory is a
‘tools’ directory that contains the Python installation:

     # Without -ExcludeVersion
     > .\python.3.5.2\tools\python.exe -V
     Python 3.5.2

     # With -ExcludeVersion
     > .\python\tools\python.exe -V
     Python 3.5.2

In general, nuget packages are not upgradeable, and newer versions
should be installed side-by-side and referenced using the full path.
Alternatively, delete the package directory manually and install it
again.  Many CI systems will do this automatically if they do not
preserve files between builds.

Alongside the ‘tools’ directory is a ‘build\native’ directory.  This
contains a MSBuild properties file ‘python.props’ that can be used in a
C++ project to reference the Python install.  Including the settings
will automatically use the headers and import libraries in your build.

The package information pages on nuget.org are
www.nuget.org/packages/python(2) for the 64-bit version,
www.nuget.org/packages/pythonx86(3) for the 32-bit version, and
www.nuget.org/packages/pythonarm64(4) for the ARM64 version

* Menu:

* Free-threaded packages::

   ---------- Footnotes ----------

   (1) https://www.nuget.org/

   (2) https://www.nuget.org/packages/python

   (3) https://www.nuget.org/packages/pythonx86

   (4) https://www.nuget.org/packages/pythonarm64


File: python.info,  Node: Free-threaded packages,  Up: The nuget org packages

3.4.3.1 Free-threaded packages
..............................

Added in version 3.13.

Packages containing free-threaded binaries are named
python-freethreaded(1) for the 64-bit version, pythonx86-freethreaded(2)
for the 32-bit version, and pythonarm64-freethreaded(3) for the ARM64
version.  These packages contain both the ‘python3.13t.exe’ and
‘python.exe’ entry points, both of which run free threaded.

   ---------- Footnotes ----------

   (1) https://www.nuget.org/packages/python-freethreaded

   (2) https://www.nuget.org/packages/pythonx86-freethreaded

   (3) https://www.nuget.org/packages/pythonarm64-freethreaded


File: python.info,  Node: Alternative bundles,  Next: Supported Windows versions,  Prev: The nuget org packages,  Up: Using Python on Windows

3.4.4 Alternative bundles
-------------------------

Besides the standard CPython distribution, there are modified packages
including additional functionality.  The following is a list of popular
versions and their key features:

ActivePython(1)

     Installer with multi-platform compatibility, documentation, PyWin32

Anaconda(2)

     Popular scientific modules (such as numpy, scipy and pandas) and
     the ‘conda’ package manager.

Enthought Deployment Manager(3)

     «The Next Generation Python Environment and Package Manager».

     Previously Enthought provided Canopy, but it reached end of life in
     2016(4).

WinPython(5)

     Windows-specific distribution with prebuilt scientific packages and
     tools for building packages.

Note that these packages may not include the latest versions of Python
or other libraries, and are not maintained or supported by the core
Python team.

   ---------- Footnotes ----------

   (1) https://www.activestate.com/products/python/

   (2) https://www.anaconda.com/download/

   (3) https://assets.enthought.com/downloads/edm/

   (4) 
https://support.enthought.com/hc/en-us/articles/360038600051-Canopy-GUI-end-of-life-transition-to-the-Enthought-Deployment-Manager-EDM-and-Visual-Studio-Code

   (5) https://winpython.github.io/


File: python.info,  Node: Supported Windows versions,  Next: Removing the MAX_PATH limitation,  Prev: Alternative bundles,  Up: Using Python on Windows

3.4.5 Supported Windows versions
--------------------------------

As specified in PEP 11(1), a Python release only supports a Windows
platform while Microsoft considers the platform under extended support.
This means that Python 3.14 supports Windows 10 and newer.  If you
require Windows 7 support, please install Python 3.8.  If you require
Windows 8.1 support, please install Python 3.12.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0011/


File: python.info,  Node: Removing the MAX_PATH limitation,  Next: UTF-8 mode,  Prev: Supported Windows versions,  Up: Using Python on Windows

3.4.6 Removing the MAX_PATH limitation
--------------------------------------

Windows historically has limited path lengths to 260 characters.  This
meant that paths longer than this would not resolve and errors would
result.

In the latest versions of Windows, this limitation can be expanded to
over 32,000 characters.  Your administrator will need to activate the
«Enable Win32 long paths» group policy, or set ‘LongPathsEnabled’ to ‘1’
in the registry key
‘HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem’.

This allows the *note open(): 316. function, the *note os: a5. module
and most other path functionality to accept and return paths longer than
260 characters.

After changing the above option and rebooting, no further configuration
is required.


File: python.info,  Node: UTF-8 mode,  Next: Finding modules,  Prev: Removing the MAX_PATH limitation,  Up: Using Python on Windows

3.4.7 UTF-8 mode
----------------

Added in version 3.7.

Windows still uses legacy encodings for the system encoding (the ANSI
Code Page).  Python uses it for the default encoding of text files (e.g.
*note locale.getencoding(): 329.).

This may cause issues because UTF-8 is widely used on the internet and
most Unix systems, including WSL (Windows Subsystem for Linux).

You can use the *note Python UTF-8 Mode: 867. to change the default text
encoding to UTF-8.  You can enable the *note Python UTF-8 Mode: 867. via
the ‘-X utf8’ command line option, or the ‘PYTHONUTF8=1’ environment
variable.  See *note PYTHONUTF8: cd1. for enabling UTF-8 mode, and *note
Python install manager: 1fb2. for how to modify environment variables.

When the *note Python UTF-8 Mode: 867. is enabled, you can still use the
system encoding (the ANSI Code Page) via the «mbcs» codec.

Note that adding ‘PYTHONUTF8=1’ to the default environment variables
will affect all Python 3.7+ applications on your system.  If you have
any Python 3.7+ applications which rely on the legacy system encoding,
it is recommended to set the environment variable temporarily or use the
‘-X utf8’ command line option.

     Nota: Even when UTF-8 mode is disabled, Python uses UTF-8 by
     default on Windows for:

        * Console I/O including standard I/O (see PEP 528(1) for
          details).

        * The *note filesystem encoding: 75e. (see PEP 529(2) for
          details).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0528/

   (2) https://peps.python.org/pep-0529/


File: python.info,  Node: Finding modules,  Next: Additional modules,  Prev: UTF-8 mode,  Up: Using Python on Windows

3.4.8 Finding modules
---------------------

These notes supplement the description at *note The initialization of
the sys.path module search path: 18c4. with detailed Windows notes.

When no ‘._pth’ file is found, this is how *note sys.path: 3e4. is
populated on Windows:

   * An empty entry is added at the start, which corresponds to the
     current directory.

   * If the environment variable *note PYTHONPATH: 121f. exists, as
     described in *note Environment variables: 808, its entries are
     added next.  Note that on Windows, paths in this variable must be
     separated by semicolons, to distinguish them from the colon used in
     drive identifiers (‘C:\’ etc.).

   * Additional «application paths» can be added in the registry as
     subkeys of ‘\SOFTWARE\Python\PythonCore{version}\PythonPath’ under
     both the ‘HKEY_CURRENT_USER’ and ‘HKEY_LOCAL_MACHINE’ hives.
     Subkeys which have semicolon-delimited path strings as their
     default value will cause each path to be added to *note sys.path:
     3e4.  (Note that all known installers only use HKLM, so HKCU is
     typically empty.)

   * If the environment variable *note PYTHONHOME: 3f0. is set, it is
     assumed as «Python Home».  Otherwise, the path of the main Python
     executable is used to locate a «landmark file» (either ‘Lib\os.py’
     or ‘pythonXY.zip’) to deduce the «Python Home».  If a Python home
     is found, the relevant sub-directories added to *note sys.path:
     3e4. (‘Lib’, ‘plat-win’, etc) are based on that folder.  Otherwise,
     the core Python path is constructed from the PythonPath stored in
     the registry.

   * If the Python Home cannot be located, no *note PYTHONPATH: 121f. is
     specified in the environment, and no registry entries can be found,
     a default path with relative entries is used (e.g.
     ‘.\Lib;.\plat-win’, etc).

If a ‘pyvenv.cfg’ file is found alongside the main executable or in the
directory one level above the executable, the following variations
apply:

   * If ‘home’ is an absolute path and *note PYTHONHOME: 3f0. is not
     set, this path is used instead of the path to the main executable
     when deducing the home location.

The end result of all this is:

   * When running ‘python.exe’, or any other .exe in the main Python
     directory (either an installed version, or directly from the
     PCbuild directory), the core path is deduced, and the core paths in
     the registry are ignored.  Other «application paths» in the
     registry are always read.

   * When Python is hosted in another .exe (different directory,
     embedded via COM, etc), the «Python Home» will not be deduced, so
     the core path from the registry is used.  Other «application paths»
     in the registry are always read.

   * If Python can’t find its home and there are no registry value
     (frozen .exe, some very strange installation setup) you get a path
     with some default, but relative, paths.

For those who want to bundle Python into their application or
distribution, the following advice will prevent conflicts with other
installations:

   * Include a ‘._pth’ file alongside your executable containing the
     directories to include.  This will ignore paths listed in the
     registry and environment variables, and also ignore *note site: cc.
     unless ‘import site’ is listed.

   * If you are loading ‘python3.dll’ or ‘python37.dll’ in your own
     executable, explicitly set *note PyConfig.module_search_paths: 643.
     before *note Py_InitializeFromConfig(): 3f6.

   * Clear and/or overwrite *note PYTHONPATH: 121f. and set *note
     PYTHONHOME: 3f0. before launching ‘python.exe’ from your
     application.

   * If you cannot use the previous suggestions (for example, you are a
     distribution that allows people to run ‘python.exe’ directly),
     ensure that the landmark file (‘Lib\os.py’) exists in your install
     directory.  (Note that it will not be detected inside a ZIP file,
     but a correctly named ZIP file will be detected instead.)

These will ensure that the files in a system-wide installation will not
take precedence over the copy of the standard library bundled with your
application.  Otherwise, your users may experience problems using your
application.  Note that the first suggestion is the best, as the others
may still be susceptible to non-standard paths in the registry and user
site-packages.

Cambiato nella versione 3.6: Add ‘._pth’ file support and removes
‘applocal’ option from ‘pyvenv.cfg’.

Cambiato nella versione 3.6: Add ‘python`XX'.zip’ as a potential
landmark when directly adjacent to the executable.

Deprecato dalla versione 3.6: Modules specified in the registry under
‘Modules’ (not ‘PythonPath’) may be imported by *note
importlib.machinery.WindowsRegistryFinder: f28.  This finder is enabled
on Windows in 3.6.0 and earlier, but may need to be explicitly added to
*note sys.meta_path: f29. in the future.


File: python.info,  Node: Additional modules,  Next: Compiling Python on Windows,  Prev: Finding modules,  Up: Using Python on Windows

3.4.9 Additional modules
------------------------

Even though Python aims to be portable among all platforms, there are
features that are unique to Windows.  A couple of modules, both in the
standard library and external, and snippets exist to use these features.

The Windows-specific standard modules are documented in *note MS Windows
Specific Services: 2209.

* Menu:

* PyWin32::
* cx_Freeze::


File: python.info,  Node: PyWin32,  Next: cx_Freeze,  Up: Additional modules

3.4.9.1 PyWin32
...............

The PyWin32(1) module by Mark Hammond is a collection of modules for
advanced Windows-specific support.  This includes utilities for:

   * Component Object Model(2) (COM)

   * Win32 API calls

   * Registry

   * Event log

   * Microsoft Foundation Classes(3) (MFC) user interfaces

PythonWin(4) is a sample MFC application shipped with PyWin32.  It is an
embeddable IDE with a built-in debugger.

Vedi anche
..........

Win32 How Do I...?(5)

     by Tim Golden

Python and COM(6)

     by David and Paul Boddie

   ---------- Footnotes ----------

   (1) https://pypi.org/project/PyWin32/

   (2) 
https://learn.microsoft.com/windows/win32/com/component-object-model-com-portal

   (3) https://learn.microsoft.com/cpp/mfc/mfc-desktop-applications

   (4) 
https://web.archive.org/web/20060524042422/https://www.python.org/windows/pythonwin/

   (5) https://timgolden.me.uk/python/win32_how_do_i.html

   (6) https://www.boddie.org.uk/python/COM.html


File: python.info,  Node: cx_Freeze,  Prev: PyWin32,  Up: Additional modules

3.4.9.2 cx_Freeze
.................

cx_Freeze(1) wraps Python scripts into executable Windows programs
(‘`*'.exe’ files).  When you have done this, you can distribute your
application without requiring your users to install Python.

   ---------- Footnotes ----------

   (1) https://cx-freeze.readthedocs.io/en/latest/


File: python.info,  Node: Compiling Python on Windows,  Next: The full installer deprecated,  Prev: Additional modules,  Up: Using Python on Windows

3.4.10 Compiling Python on Windows
----------------------------------

If you want to compile CPython yourself, first thing you should do is
get the source(1).  You can download either the latest release’s source
or just grab a fresh checkout(2).

The source tree contains a build solution and project files for
Microsoft Visual Studio, which is the compiler used to build the
official Python releases.  These files are in the ‘PCbuild’ directory.

Check ‘PCbuild/readme.txt’ for general information on the build process.

For extension modules, consult *note Building C and C++ Extensions on
Windows: 220d.

   ---------- Footnotes ----------

   (1) https://www.python.org/downloads/source/

   (2) https://devguide.python.org/setup/#get-the-source-code


File: python.info,  Node: The full installer deprecated,  Next: Python launcher for Windows deprecated,  Prev: Compiling Python on Windows,  Up: Using Python on Windows

3.4.11 The full installer (deprecated)
--------------------------------------

Deprecato dalla versione 3.14: This installer is deprecated since 3.14
and will not be produced for Python 3.16 or later.  See *note Python
install manager: 21e7. for the modern installer.

* Menu:

* Installation steps::
* Removing the MAX_PATH limitation: Removing the MAX_PATH limitation<2>.
* Installing without UI::
* Installing without downloading::
* Modifying an install::
* Installing free-threaded binaries: Installing free-threaded binaries<2>.


File: python.info,  Node: Installation steps,  Next: Removing the MAX_PATH limitation<2>,  Up: The full installer deprecated

3.4.11.1 Installation steps
...........................

Four Python 3.14 installers are available for download - two each for
the 32-bit and 64-bit versions of the interpreter.  The 'web installer'
is a small initial download, and it will automatically download the
required components as necessary.  The 'offline installer' includes the
components necessary for a default installation and only requires an
internet connection for optional features.  See *note Installing without
downloading: 2211. for other ways to avoid downloading during
installation.

After starting the installer, one of two options may be selected:

[image src="python-figures/win_installer.png"]


If you select «Install Now»:

   * You will 'not' need to be an administrator (unless a system update
     for the C Runtime Library is required or you install the *note
     Python install manager: 7db. for all users)

   * Python will be installed into your user directory

   * The *note Python install manager: 7db. will be installed according
     to the option at the bottom of the first page

   * The standard library, test suite, launcher and pip will be
     installed

   * If selected, the install directory will be added to your ‘PATH’

   * Shortcuts will only be visible for the current user

Selecting «Customize installation» will allow you to select the features
to install, the installation location and other options or post-install
actions.  To install debugging symbols or binaries, you will need to use
this option.

To perform an all-users installation, you should select «Customize
installation».  In this case:

   * You may be required to provide administrative credentials or
     approval

   * Python will be installed into the Program Files directory

   * The *note Python install manager: 7db. will be installed into the
     Windows directory

   * Optional features may be selected during installation

   * The standard library can be pre-compiled to bytecode

   * If selected, the install directory will be added to the system
     ‘PATH’

   * Shortcuts are available for all users


File: python.info,  Node: Removing the MAX_PATH limitation<2>,  Next: Installing without UI,  Prev: Installation steps,  Up: The full installer deprecated

3.4.11.2 Removing the MAX_PATH limitation
.........................................

Windows historically has limited path lengths to 260 characters.  This
meant that paths longer than this would not resolve and errors would
result.

In the latest versions of Windows, this limitation can be expanded to
approximately 32,000 characters.  Your administrator will need to
activate the «Enable Win32 long paths» group policy, or set
‘LongPathsEnabled’ to ‘1’ in the registry key
‘HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem’.

This allows the *note open(): 316. function, the *note os: a5. module
and most other path functionality to accept and return paths longer than
260 characters.

After changing the above option, no further configuration is required.

Cambiato nella versione 3.6: Support for long paths was enabled in
Python.


File: python.info,  Node: Installing without UI,  Next: Installing without downloading,  Prev: Removing the MAX_PATH limitation<2>,  Up: The full installer deprecated

3.4.11.3 Installing without UI
..............................

All of the options available in the installer UI can also be specified
from the command line, allowing scripted installers to replicate an
installation on many machines without user interaction.  These options
may also be set without suppressing the UI in order to change some of
the defaults.

The following options (found by executing the installer with ‘/?’) can
be passed into the installer:

Name                      Description
                          
---------------------------------------------------------------------------------------
                          
/passive                  to display progress without requiring user interaction
                          
                          
/quiet                    to install/uninstall without displaying any UI
                          
                          
/simple                   to prevent user customization
                          
                          
/uninstall                to remove Python (without confirmation)
                          
                          
/layout [directory]       to pre-download all components
                          
                          
/log [filename]           to specify log files location
                          

All other options are passed as ‘name=value’, where the value is usually
‘0’ to disable a feature, ‘1’ to enable a feature, or a path.  The full
list of available options is shown below.

Name                            Description                                Default
                                                                           
----------------------------------------------------------------------------------------------------------
                                                                           
InstallAllUsers                 Perform a system-wide installation.        0
                                                                           
                                                                           
TargetDir                       The installation directory                 Selected based on
                                                                           InstallAllUsers
                                                                           
                                                                           
DefaultAllUsersTargetDir        The default installation directory for     ‘%ProgramFiles%\Python X.Y’
                                all-user installs                          or
                                                                           ‘%ProgramFiles(x86)%\Python
                                                                           X.Y’
                                                                           
                                                                           
DefaultJustForMeTargetDir       The default install directory for          ‘%LocalAppData%\Programs\Python\PythonXY’
                                just-for-me installs                       or
                                                                           ‘%LocalAppData%\Programs\Python\PythonXY-32’
                                                                           or
                                                                           ‘%LocalAppData%\Programs\Python\PythonXY-64’
                                                                           
                                                                           
DefaultCustomTargetDir          The default custom install directory       (empty)
                                displayed in the UI                        
                                
                                                                           
AssociateFiles                  Create file associations if the launcher   1
                                is also installed.                         
                                
                                                                           
CompileAll                      Compile all ‘.py’ files to ‘.pyc’.         0
                                                                           
                                                                           
PrependPath                     Prepend install and Scripts directories    0
                                to ‘PATH’ and add ‘.PY’ to ‘PATHEXT’       
                                
                                                                           
AppendPath                      Append install and Scripts directories     0
                                to ‘PATH’ and add ‘.PY’ to ‘PATHEXT’       
                                
                                                                           
Shortcuts                       Create shortcuts for the interpreter,      1
                                documentation and IDLE if installed.       
                                
                                                                           
Include_doc                     Install Python manual                      1
                                                                           
                                                                           
Include_debug                   Install debug binaries                     0
                                                                           
                                                                           
Include_dev                     Install developer headers and libraries.   1
                                Omitting this may lead to an unusable      
                                installation.
                                
                                                                           
Include_exe                     Install ‘python.exe’ and related files.    1
                                Omitting this may lead to an unusable      
                                installation.
                                
                                                                           
Include_launcher                Install                                    1
                                *note Python install manager: 7db.         
                                
                                                                           
InstallLauncherAllUsers         Installs the launcher for all users.       1
                                Also requires ‘Include_launcher’ to be     
                                set to 1
                                
                                                                           
Include_lib                     Install standard library and extension     1
                                modules.  Omitting this may lead to an     
                                unusable installation.
                                
                                                                           
Include_pip                     Install bundled pip and setuptools         1
                                                                           
                                                                           
Include_symbols                 Install debugging symbols (‘*.pdb’)        0
                                                                           
                                                                           
Include_tcltk                   Install Tcl/Tk support and IDLE            1
                                                                           
                                                                           
Include_test                    Install standard library test suite        1
                                                                           
                                                                           
Include_tools                   Install utility scripts                    1
                                                                           
                                                                           
LauncherOnly                    Only installs the launcher.  This will     0
                                override most other options.               
                                
                                                                           
SimpleInstall                   Disable most install UI                    0
                                                                           
                                                                           
SimpleInstallDescription        A custom message to display when the       (empty)
                                simplified install UI is used.             
                                

For example, to silently install a default, system-wide Python
installation, you could use the following command (from an elevated
command prompt):

     python-3.9.0.exe /quiet InstallAllUsers=1 PrependPath=1 Include_test=0

To allow users to easily install a personal copy of Python without the
test suite, you could provide a shortcut with the following command.
This will display a simplified initial page and disallow customization:

     python-3.9.0.exe InstallAllUsers=0 Include_launcher=0 Include_test=0
         SimpleInstall=1 SimpleInstallDescription="Just for me, no test suite."

(Note that omitting the launcher also omits file associations, and is
only recommended for per-user installs when there is also a system-wide
installation that included the launcher.)

The options listed above can also be provided in a file named
‘unattend.xml’ alongside the executable.  This file specifies a list of
options and values.  When a value is provided as an attribute, it will
be converted to a number if possible.  Values provided as element text
are always left as strings.  This example file sets the same options as
the previous example:

     <Options>
         <Option Name="InstallAllUsers" Value="no" />
         <Option Name="Include_launcher" Value="0" />
         <Option Name="Include_test" Value="no" />
         <Option Name="SimpleInstall" Value="yes" />
         <Option Name="SimpleInstallDescription">Just for me, no test suite</Option>
     </Options>


File: python.info,  Node: Installing without downloading,  Next: Modifying an install,  Prev: Installing without UI,  Up: The full installer deprecated

3.4.11.4 Installing without downloading
.......................................

As some features of Python are not included in the initial installer
download, selecting those features may require an internet connection.
To avoid this need, all possible components may be downloaded on-demand
to create a complete 'layout' that will no longer require an internet
connection regardless of the selected features.  Note that this download
may be bigger than required, but where a large number of installations
are going to be performed it is very useful to have a locally cached
copy.

Execute the following command from Command Prompt to download all
possible required files.  Remember to substitute ‘python-3.9.0.exe’ for
the actual name of your installer, and to create layouts in their own
directories to avoid collisions between files with the same name.

     python-3.9.0.exe /layout [optional target directory]

You may also specify the ‘/quiet’ option to hide the progress display.


File: python.info,  Node: Modifying an install,  Next: Installing free-threaded binaries<2>,  Prev: Installing without downloading,  Up: The full installer deprecated

3.4.11.5 Modifying an install
.............................

Once Python has been installed, you can add or remove features through
the Programs and Features tool that is part of Windows.  Select the
Python entry and choose «Uninstall/Change» to open the installer in
maintenance mode.

«Modify» allows you to add or remove features by modifying the
checkboxes - unchanged checkboxes will not install or remove anything.
Some options cannot be changed in this mode, such as the install
directory; to modify these, you will need to remove and then reinstall
Python completely.

«Repair» will verify all the files that should be installed using the
current settings and replace any that have been removed or modified.

«Uninstall» will remove Python entirely, with the exception of the *note
Python install manager: 7db, which has its own entry in Programs and
Features.


File: python.info,  Node: Installing free-threaded binaries<2>,  Prev: Modifying an install,  Up: The full installer deprecated

3.4.11.6 Installing free-threaded binaries
..........................................

Added in version 3.13.

To install pre-built binaries with free-threading enabled (see PEP
703(1)), you should select «Customize installation».  The second page of
options includes the «Download free-threaded binaries» checkbox.

[image src="python-figures/win_install_freethreaded.png"]


Selecting this option will download and install additional binaries to
the same location as the main Python install.  The main executable is
called ‘python3.13t.exe’, and other binaries either receive a ‘t’ suffix
or a full ABI suffix.  Python source files and bundled third-party
dependencies are shared with the main install.

The free-threaded version is registered as a regular Python install with
the tag ‘3.13t’ (with a ‘-32’ or ‘-arm64’ suffix as normal for those
platforms).  This allows tools to discover it, and for the *note Python
install manager: 7db. to support ‘py.exe -3.13t’.  Note that the
launcher will interpret ‘py.exe -3’ (or a ‘python3’ shebang) as «the
latest 3.x install», which will prefer the free-threaded binaries over
the regular ones, while ‘py.exe -3.13’ will not.  If you use the short
style of option, you may prefer to not install the free-threaded
binaries at this time.

To specify the install option at the command line, use
‘Include_freethreaded=1’.  See *note Installing without downloading:
2211. for instructions on pre-emptively downloading the additional
binaries for offline install.  The options to include debug symbols and
binaries also apply to the free-threaded builds.

Free-threaded binaries are also available *note on nuget.org: 21e5.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0703/


File: python.info,  Node: Python launcher for Windows deprecated,  Prev: The full installer deprecated,  Up: Using Python on Windows

3.4.12 Python launcher for Windows (deprecated)
-----------------------------------------------

Deprecato dalla versione 3.14: The launcher and this documentation have
been superseded by the Python Install Manager described above.  This is
preserved temporarily for historical interest.

Added in version 3.3.

The Python launcher for Windows is a utility which aids in locating and
executing of different Python versions.  It allows scripts (or the
command-line) to indicate a preference for a specific Python version,
and will locate and execute that version.

Unlike the ‘PATH’ variable, the launcher will correctly select the most
appropriate version of Python.  It will prefer per-user installations
over system-wide ones, and orders by language version rather than using
the most recently installed version.

The launcher was originally specified in PEP 397(1).

* Menu:

* Getting started::
* Shebang lines: Shebang lines<2>.
* Arguments in shebang lines::
* Customization::
* Diagnostics::
* Dry run::
* Install on demand::
* Return codes::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0397/


File: python.info,  Node: Getting started,  Next: Shebang lines<2>,  Up: Python launcher for Windows deprecated

3.4.12.1 Getting started
........................

* Menu:

* From the command-line::
* Virtual environments::
* From a script::
* From file associations::


File: python.info,  Node: From the command-line,  Next: Virtual environments,  Up: Getting started

3.4.12.2 From the command-line
..............................

Cambiato nella versione 3.6.

System-wide installations of Python 3.3 and later will put the launcher
on your ‘PATH’.  The launcher is compatible with all available versions
of Python, so it does not matter which version is installed.  To check
that the launcher is available, execute the following command in Command
Prompt:

     py

You should find that the latest version of Python you have installed is
started - it can be exited as normal, and any additional command-line
arguments specified will be sent directly to Python.

If you have multiple versions of Python installed (e.g., 3.7 and 3.14)
you will have noticed that Python 3.14 was started - to launch Python
3.7, try the command:

     py -3.7

If you want the latest version of Python 2 you have installed, try the
command:

     py -2

If you see the following error, you do not have the launcher installed:

     'py' is not recognized as an internal or external command,
     operable program or batch file.

The command:

     py --list

displays the currently installed version(s) of Python.

The ‘-x.y’ argument is the short form of the ‘-V:Company/Tag’ argument,
which allows selecting a specific Python runtime, including those that
may have come from somewhere other than python.org.  Any runtime
registered by following PEP 514(1) will be discoverable.  The ‘--list’
command lists all available runtimes using the ‘-V:’ format.

When using the ‘-V:’ argument, specifying the Company will limit
selection to runtimes from that provider, while specifying only the Tag
will select from all providers.  Note that omitting the slash implies a
tag:

     # Select any '3.*' tagged runtime
     py -V:3

     # Select any 'PythonCore' released runtime
     py -V:PythonCore/

     # Select PythonCore's latest Python 3 runtime
     py -V:PythonCore/3

The short form of the argument (‘-3’) only ever selects from core Python
releases, and not other distributions.  However, the longer form
(‘-V:3’) will select from any.

The Company is matched on the full string, case-insensitive.  The Tag is
matched on either the full string, or a prefix, provided the next
character is a dot or a hyphen.  This allows ‘-V:3.1’ to match ‘3.1-32’,
but not ‘3.10’.  Tags are sorted using numerical ordering (‘3.10’ is
newer than ‘3.1’), but are compared using text (‘-V:3.01’ does not match
‘3.1’).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0514/


File: python.info,  Node: Virtual environments,  Next: From a script,  Prev: From the command-line,  Up: Getting started

3.4.12.3 Virtual environments
.............................

Added in version 3.5.

If the launcher is run with no explicit Python version specification,
and a virtual environment (created with the standard library *note venv:
117. module or the external ‘virtualenv’ tool) active, the launcher will
run the virtual environment’s interpreter rather than the global one.
To run the global interpreter, either deactivate the virtual
environment, or explicitly specify the global Python version.


File: python.info,  Node: From a script,  Next: From file associations,  Prev: Virtual environments,  Up: Getting started

3.4.12.4 From a script
......................

Let’s create a test Python script - create a file called ‘hello.py’ with
the following contents

     #! python
     import sys
     sys.stdout.write("hello from Python %s\n" % (sys.version,))

From the directory in which hello.py lives, execute the command:

     py hello.py

You should notice the version number of your latest Python 2.x
installation is printed.  Now try changing the first line to be:

     #! python3

Re-executing the command should now print the latest Python 3.x
information.  As with the above command-line examples, you can specify a
more explicit version qualifier.  Assuming you have Python 3.7
installed, try changing the first line to ‘#! python3.7’ and you should
find the 3.7 version information printed.

Note that unlike interactive use, a bare «python» will use the latest
version of Python 2.x that you have installed.  This is for backward
compatibility and for compatibility with Unix, where the command
‘python’ typically refers to Python 2.


File: python.info,  Node: From file associations,  Prev: From a script,  Up: Getting started

3.4.12.5 From file associations
...............................

The launcher should have been associated with Python files (i.e.  ‘.py’,
‘.pyw’, ‘.pyc’ files) when it was installed.  This means that when you
double-click on one of these files from Windows explorer the launcher
will be used, and therefore you can use the same facilities described
above to have the script specify the version which should be used.

The key benefit of this is that a single launcher can support multiple
Python versions at the same time depending on the contents of the first
line.


File: python.info,  Node: Shebang lines<2>,  Next: Arguments in shebang lines,  Prev: Getting started,  Up: Python launcher for Windows deprecated

3.4.12.6 Shebang lines
......................

If the first line of a script file starts with ‘#!’, it is known as a
«shebang» line.  Linux and other Unix like operating systems have native
support for such lines and they are commonly used on such systems to
indicate how a script should be executed.  This launcher allows the same
facilities to be used with Python scripts on Windows and the examples
above demonstrate their use.

To allow shebang lines in Python scripts to be portable between Unix and
Windows, this launcher supports a number of “virtual” commands to
specify which interpreter to use.  The supported virtual commands are:

   * ‘/usr/bin/env’

   * ‘/usr/bin/python’

   * ‘/usr/local/bin/python’

   * ‘python’

For example, if the first line of your script starts with

     #! /usr/bin/python

The default Python or an active virtual environment will be located and
used.  As many Python scripts written to work on Unix will already have
this line, you should find these scripts can be used by the launcher
without modification.  If you are writing a new script on Windows which
you hope will be useful on Unix, you should use one of the shebang lines
starting with ‘/usr’.

Any of the above virtual commands can be suffixed with an explicit
version (either just the major version, or the major and minor version).
Furthermore the 32-bit version can be requested by adding «-32» after
the minor version.  I.e.  ‘/usr/bin/python3.7-32’ will request usage of
the 32-bit Python 3.7.  If a virtual environment is active, the version
will be ignored and the environment will be used.

Added in version 3.7: Beginning with python launcher 3.7 it is possible
to request 64-bit version by the «-64» suffix.  Furthermore it is
possible to specify a major and architecture without minor (i.e.
‘/usr/bin/python3-64’).

Cambiato nella versione 3.11: The «-64» suffix is deprecated, and now
implies «any architecture that is not provably i386/32-bit».  To request
a specific environment, use the new ‘-V:TAG’ argument with the complete
tag.

Cambiato nella versione 3.13: Virtual commands referencing ‘python’ now
prefer an active virtual environment rather than searching ‘PATH’.  This
handles cases where the shebang specifies ‘/usr/bin/env python3’ but
‘python3.exe’ is not present in the active environment.

The ‘/usr/bin/env’ form of shebang line has one further special
property.  Before looking for installed Python interpreters, this form
will search the executable ‘PATH’ for a Python executable matching the
name provided as the first argument.  This corresponds to the behaviour
of the Unix ‘env’ program, which performs a ‘PATH’ search.  If an
executable matching the first argument after the ‘env’ command cannot be
found, but the argument starts with ‘python’, it will be handled as
described for the other virtual commands.  The environment variable
‘PYLAUNCHER_NO_SEARCH_PATH’ may be set (to any value) to skip this
search of ‘PATH’.

Shebang lines that do not match any of these patterns are looked up in
the ‘[commands]’ section of the launcher’s *note .INI file: 221e.  This
may be used to handle certain commands in a way that makes sense for
your system.  The name of the command must be a single argument (no
spaces in the shebang executable), and the value substituted is the full
path to the executable (additional arguments specified in the .INI will
be quoted as part of the filename).

     [commands]
     /bin/xpython=C:\Program Files\XPython\python.exe

Any commands not found in the .INI file are treated as 'Windows'
executable paths that are absolute or relative to the directory
containing the script file.  This is a convenience for Windows-only
scripts, such as those generated by an installer, since the behavior is
not compatible with Unix-style shells.  These paths may be quoted, and
may include multiple arguments, after which the path to the script and
any additional arguments will be appended.


File: python.info,  Node: Arguments in shebang lines,  Next: Customization,  Prev: Shebang lines<2>,  Up: Python launcher for Windows deprecated

3.4.12.7 Arguments in shebang lines
...................................

The shebang lines can also specify additional options to be passed to
the Python interpreter.  For example, if you have a shebang line:

     #! /usr/bin/python -v

Then Python will be started with the ‘-v’ option


File: python.info,  Node: Customization,  Next: Diagnostics,  Prev: Arguments in shebang lines,  Up: Python launcher for Windows deprecated

3.4.12.8 Customization
......................

* Menu:

* Customization via INI files::
* Customizing default Python versions::


File: python.info,  Node: Customization via INI files,  Next: Customizing default Python versions,  Up: Customization

3.4.12.9 Customization via INI files
....................................

Two .ini files will be searched by the launcher - ‘py.ini’ in the
current user’s application data directory (‘%LOCALAPPDATA%’ or
‘$env:LocalAppData’) and ‘py.ini’ in the same directory as the launcher.
The same .ini files are used for both the “console” version of the
launcher (i.e.  py.exe) and for the “windows” version (i.e.  pyw.exe).

Customization specified in the «application directory» will have
precedence over the one next to the executable, so a user, who may not
have write access to the .ini file next to the launcher, can override
commands in that global .ini file.


File: python.info,  Node: Customizing default Python versions,  Prev: Customization via INI files,  Up: Customization

3.4.12.10 Customizing default Python versions
.............................................

In some cases, a version qualifier can be included in a command to
dictate which version of Python will be used by the command.  A version
qualifier starts with a major version number and can optionally be
followed by a period (“.”) and a minor version specifier.  Furthermore
it is possible to specify if a 32 or 64 bit implementation shall be
requested by adding «-32» or «-64».

For example, a shebang line of ‘#!python’ has no version qualifier,
while ‘#!python3’ has a version qualifier which specifies only a major
version.

If no version qualifiers are found in a command, the environment
variable ‘PY_PYTHON’ can be set to specify the default version
qualifier.  If it is not set, the default is «3».  The variable can
specify any value that may be passed on the command line, such as «3»,
«3.7», «3.7-32» or «3.7-64».  (Note that the «-64» option is only
available with the launcher included with Python 3.7 or newer.)

If no minor version qualifiers are found, the environment variable
‘PY_PYTHON{major}’ (where ‘{major}’ is the current major version
qualifier as determined above) can be set to specify the full version.
If no such option is found, the launcher will enumerate the installed
Python versions and use the latest minor release found for the major
version, which is likely, although not guaranteed, to be the most
recently installed version in that family.

On 64-bit Windows with both 32-bit and 64-bit implementations of the
same (major.minor) Python version installed, the 64-bit version will
always be preferred.  This will be true for both 32-bit and 64-bit
implementations of the launcher - a 32-bit launcher will prefer to
execute a 64-bit Python installation of the specified version if
available.  This is so the behavior of the launcher can be predicted
knowing only what versions are installed on the PC and without regard to
the order in which they were installed (i.e., without knowing whether a
32 or 64-bit version of Python and corresponding launcher was installed
last).  As noted above, an optional «-32» or «-64» suffix can be used on
a version specifier to change this behaviour.

Examples:

   * If no relevant options are set, the commands ‘python’ and ‘python2’
     will use the latest Python 2.x version installed and the command
     ‘python3’ will use the latest Python 3.x installed.

   * The command ‘python3.7’ will not consult any options at all as the
     versions are fully specified.

   * If ‘PY_PYTHON=3’, the commands ‘python’ and ‘python3’ will both use
     the latest installed Python 3 version.

   * If ‘PY_PYTHON=3.7-32’, the command ‘python’ will use the 32-bit
     implementation of 3.7 whereas the command ‘python3’ will use the
     latest installed Python (PY_PYTHON was not considered at all as a
     major version was specified.)

   * If ‘PY_PYTHON=3’ and ‘PY_PYTHON3=3.7’, the commands ‘python’ and
     ‘python3’ will both use specifically 3.7

In addition to environment variables, the same settings can be
configured in the .INI file used by the launcher.  The section in the
INI file is called ‘[defaults]’ and the key name will be the same as the
environment variables without the leading ‘PY_’ prefix (and note that
the key names in the INI file are case insensitive.)  The contents of an
environment variable will override things specified in the INI file.

For example:

   * Setting ‘PY_PYTHON=3.7’ is equivalent to the INI file containing:

     [defaults]
     python=3.7

   * Setting ‘PY_PYTHON=3’ and ‘PY_PYTHON3=3.7’ is equivalent to the INI
     file containing:

     [defaults]
     python=3
     python3=3.7


File: python.info,  Node: Diagnostics,  Next: Dry run,  Prev: Customization,  Up: Python launcher for Windows deprecated

3.4.12.11 Diagnostics
.....................

If an environment variable ‘PYLAUNCHER_DEBUG’ is set (to any value), the
launcher will print diagnostic information to stderr (i.e.  to the
console).  While this information manages to be simultaneously verbose
'and' terse, it should allow you to see what versions of Python were
located, why a particular version was chosen and the exact command-line
used to execute the target Python.  It is primarily intended for testing
and debugging.


File: python.info,  Node: Dry run,  Next: Install on demand,  Prev: Diagnostics,  Up: Python launcher for Windows deprecated

3.4.12.12 Dry run
.................

If an environment variable ‘PYLAUNCHER_DRYRUN’ is set (to any value),
the launcher will output the command it would have run, but will not
actually launch Python.  This may be useful for tools that want to use
the launcher to detect and then launch Python directly.  Note that the
command written to standard output is always encoded using UTF-8, and
may not render correctly in the console.


File: python.info,  Node: Install on demand,  Next: Return codes,  Prev: Dry run,  Up: Python launcher for Windows deprecated

3.4.12.13 Install on demand
...........................

If an environment variable ‘PYLAUNCHER_ALLOW_INSTALL’ is set (to any
value), and the requested Python version is not installed but is
available on the Microsoft Store, the launcher will attempt to install
it.  This may require user interaction to complete, and you may need to
run the command again.

An additional ‘PYLAUNCHER_ALWAYS_INSTALL’ variable causes the launcher
to always try to install Python, even if it is detected.  This is mainly
intended for testing (and should be used with ‘PYLAUNCHER_DRYRUN’).


File: python.info,  Node: Return codes,  Prev: Install on demand,  Up: Python launcher for Windows deprecated

3.4.12.14 Return codes
......................

The following exit codes may be returned by the Python launcher.
Unfortunately, there is no way to distinguish these from the exit code
of Python itself.

The names of codes are as used in the sources, and are only for
reference.  There is no way to access or resolve them apart from reading
this page.  Entries are listed in alphabetical order of names.

Name                    Value       Description
                                    
----------------------------------------------------------------------------------------
                                    
RC_BAD_VENV_CFG         107         A ‘pyvenv.cfg’ was found but is corrupt.
                                    
                                    
RC_CREATE_PROCESS       101         Failed to launch Python.
                                    
                                    
RC_INSTALLING           111         An install was started, but the command will need
                                    to be re-run after it completes.
                                    
                                    
RC_INTERNAL_ERROR       109         Unexpected error.  Please report a bug.
                                    
                                    
RC_NO_COMMANDLINE       108         Unable to obtain command line from the operating
                                    system.
                                    
                                    
RC_NO_PYTHON            103         Unable to locate the requested version.
                                    
                                    
RC_NO_VENV_CFG          106         A ‘pyvenv.cfg’ was required but not found.
                                    


File: python.info,  Node: Using Python on macOS,  Next: Using Python on Android,  Prev: Using Python on Windows,  Up: Python Setup and Usage

3.5 Using Python on macOS
=========================

This document aims to give an overview of macOS-specific behavior you
should know about to get started with Python on Mac computers.  Python
on a Mac running macOS is very similar to Python on other Unix-derived
platforms, but there are some differences in installation and some
features.

There are various ways to obtain and install Python for macOS. Pre-built
versions of the most recent versions of Python are available from a
number of distributors.  Much of this document describes use of the
Pythons provided by the CPython release team for download from the
python.org website(1).  See *note Alternative Distributions: 222b. for
some other options.
* Menu:

* Using Python for macOS from python.org: Using Python for macOS from python org.
* Alternative Distributions::
* Installing Additional Python Packages::
* GUI Programming::
* Advanced Topics::
* Other Resources::

   ---------- Footnotes ----------

   (1) https://www.python.org/downloads/


File: python.info,  Node: Using Python for macOS from python org,  Next: Alternative Distributions,  Up: Using Python on macOS

3.5.1 Using Python for macOS from ‘python.org’
----------------------------------------------

* Menu:

* Installation steps: Installation steps<2>.
* How to run a Python script::


File: python.info,  Node: Installation steps<2>,  Next: How to run a Python script,  Up: Using Python for macOS from python org

3.5.1.1 Installation steps
..........................

For current Python versions(1) (other than those in ‘security’ status),
the release team produces a 'Python for macOS' installer package for
each new release.  A list of available installers is available here(2).
We recommend using the most recent supported Python version where
possible.  Current installers provide a universal2 binary(3) build of
Python which runs natively on all Macs (Apple Silicon and Intel) that
are supported by a wide range of macOS versions, currently typically
from at least 'macOS 10.15 Catalina' on.

The downloaded file is a standard macOS installer package file (‘.pkg’).
File integrity information (checksum, size, sigstore signature, etc) for
each file is included on the release download page.  Installer packages
and their contents are signed and notarized with ‘Python Software
Foundation’ Apple Developer ID certificates to meet macOS Gatekeeper
requirements(4).

For a default installation, double-click on the downloaded installer
package file.  This should launch the standard macOS Installer app and
display the first of several installer windows steps.

[image src="python-figures/mac_installer_01_introduction.png"]


Clicking on the 'Continue' button brings up the 'Read Me' for this
installer.  Besides other important information, the 'Read Me' documents
which Python version is going to be installed and on what versions of
macOS it is supported.  You may need to scroll through to read the whole
file.  By default, this 'Read Me' will also be installed in
‘/Applications/Python 3.14/’ and available to read anytime.

[image src="python-figures/mac_installer_02_readme.png"]


Clicking on 'Continue' proceeds to display the license for Python and
for other included software.  You will then need to 'Agree' to the
license terms before proceeding to the next step.  This license file
will also be installed and available to be read later.

[image src="python-figures/mac_installer_03_license.png"]


After the license terms are accepted, the next step is the 'Installation
Type' display.  For most uses, the standard set of installation
operations is appropriate.

[image src="python-figures/mac_installer_04_installation_type.png"]


By pressing the 'Customize' button, you can choose to omit or select
certain package components of the installer.  Click on each package name
to see a description of what it installs.  To also install support for
the optional free-threaded feature, see *note Installing Free-threaded
Binaries: 499.

[image src="python-figures/mac_installer_05_custom_install.png"]


In either case, clicking 'Install' will begin the install process by
asking permission to install new software.  A macOS user name with
‘Administrator’ privilege is needed as the installed Python will be
available to all users of the Mac.

When the installation is complete, the 'Summary' window will appear.

[image src="python-figures/mac_installer_06_summary.png"]


Double-click on the ‘Install Certificates.command’ icon or file in the
‘/Applications/Python 3.14/’ window to complete the installation.

[image src="python-figures/mac_installer_07_applications.png"]


This will open a temporary ‘Terminal’ shell window that will use the new
Python to download and install SSL root certificates for its use.

[image src="python-figures/mac_installer_08_install_certificates.png"]


If ‘Successfully installed certifi’ and ‘update complete’ appears in the
terminal window, the installation is complete.  Close this terminal
window and the installer window.

A default install will include:

   * A ‘Python 3.14’ folder in your ‘Applications’ folder.  In here you
     find ‘IDLE’, the development environment that is a standard part of
     official Python distributions; and ‘Python Launcher’, which handles
     double-clicking Python scripts from the macOS Finder(5).

   * A framework ‘/Library/Frameworks/Python.framework’, which includes
     the Python executable and libraries.  The installer adds this
     location to your shell path.  To uninstall Python, you can remove
     these three things.  Symlinks to the Python executable are placed
     in ‘/usr/local/bin/’.

     Nota: Recent versions of macOS include a ‘python3’ command in
     ‘/usr/bin/python3’ that links to a usually older and incomplete
     version of Python provided by and for use by the Apple development
     tools, ‘Xcode’ or the ‘Command Line Tools for Xcode’.  You should
     never modify or attempt to delete this installation, as it is
     Apple-controlled and is used by Apple-provided or third-party
     software.  If you choose to install a newer Python version from
     ‘python.org’, you will have two different but functional Python
     installations on your computer that can co-exist.  The default
     installer options should ensure that its ‘python3’ will be used
     instead of the system ‘python3’.

   ---------- Footnotes ----------

   (1) https://www.python.org/downloads/

   (2) https://www.python.org/downloads/macos/

   (3) https://en.wikipedia.org/wiki/Universal_binary

   (4) https://support.apple.com/en-us/102445

   (5) https://support.apple.com/en-us/HT201732


File: python.info,  Node: How to run a Python script,  Prev: Installation steps<2>,  Up: Using Python for macOS from python org

3.5.1.2 How to run a Python script
..................................

There are two ways to invoke the Python interpreter.  If you are
familiar with using a Unix shell in a terminal window, you can invoke
‘python3.14’ or ‘python3’ optionally followed by one or more command
line options (described in *note Command line and environment: 1d8f.).
The Python tutorial also has a useful section on *note using Python
interactively from a shell: 495.

You can also invoke the interpreter through an integrated development
environment.  *note IDLE — Python editor and shell: 1217. is a basic
editor and interpreter environment which is included with the standard
distribution of Python.  ‘IDLE’ includes a Help menu that allows you to
access Python documentation.  If you are completely new to Python, you
can read the tutorial introduction in that document.

There are many other editors and IDEs available, see *note Editors and
IDEs: 2231. for more information.

To run a Python script file from the terminal window, you can invoke the
interpreter with the name of the script file:

     ‘python3.14’ ‘myscript.py’

To run your script from the Finder, you can either:

   * Drag it to ‘Python Launcher’.

   * Select ‘Python Launcher’ as the default application to open your
     script (or any ‘.py’ script) through the Finder Info window and
     double-click it.  ‘Python Launcher’ has various preferences to
     control how your script is launched.  Option-dragging allows you to
     change these for one invocation, or use its ‘Preferences’ menu to
     change things globally.

Be aware that running the script directly from the macOS Finder might
produce different results than when running from a terminal window as
the script will not be run in the usual shell environment including any
setting of environment variables in shell profiles.  And, as with any
other script or program, be certain of what you are about to run.


File: python.info,  Node: Alternative Distributions,  Next: Installing Additional Python Packages,  Prev: Using Python for macOS from python org,  Up: Using Python on macOS

3.5.2 Alternative Distributions
-------------------------------

Besides the standard ‘python.org’ for macOS installer, there are
third-party distributions for macOS that may include additional
functionality.  Some popular distributions and their key features:

ActivePython(1)

     Installer with multi-platform compatibility, documentation

Anaconda(2)

     Popular scientific modules (such as numpy, scipy, and pandas) and
     the ‘conda’ package manager.

Homebrew(3)

     Package manager for macOS including multiple versions of Python and
     many third-party Python-based packages (including numpy, scipy, and
     pandas).

MacPorts(4)

     Another package manager for macOS including multiple versions of
     Python and many third-party Python-based packages.  May include
     pre-built versions of Python and many packages for older versions
     of macOS.

Note that distributions might not include the latest versions of Python
or other libraries, and are not maintained or supported by the core
Python team.

   ---------- Footnotes ----------

   (1) https://www.activestate.com/products/python/

   (2) https://www.anaconda.com/download/

   (3) https://brew.sh

   (4) https://www.macports.org


File: python.info,  Node: Installing Additional Python Packages,  Next: GUI Programming,  Prev: Alternative Distributions,  Up: Using Python on macOS

3.5.3 Installing Additional Python Packages
-------------------------------------------

Refer to the Python Packaging User Guide(1) for more information.

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/tutorials/installing-packages/


File: python.info,  Node: GUI Programming,  Next: Advanced Topics,  Prev: Installing Additional Python Packages,  Up: Using Python on macOS

3.5.4 GUI Programming
---------------------

There are several options for building GUI applications on the Mac with
Python.

The standard Python GUI toolkit is *note tkinter: f6, based on the
cross-platform Tk toolkit (‘https://www.tcl.tk’).  A macOS-native
version of Tk is included with the installer.

'PyObjC' is a Python binding to Apple’s Objective-C/Cocoa framework.
Information on PyObjC is available from pyobjc(1).

A number of alternative macOS GUI toolkits are available including:

   * PySide(2): Official Python bindings to the Qt GUI toolkit(3).

   * PyQt(4): Alternative Python bindings to Qt.

   * Kivy(5): A cross-platform GUI toolkit that supports desktop and
     mobile platforms.

   * Toga(6): Part of the BeeWare Project(7); supports desktop, mobile,
     web and console apps.

   * wxPython(8): A cross-platform toolkit that supports desktop
     operating systems.

   ---------- Footnotes ----------

   (1) https://pypi.org/project/pyobjc/

   (2) https://www.qt.io/qt-for-python

   (3) https://wiki.qt.io/Qt_for_Python

   (4) https://riverbankcomputing.com/software/pyqt/

   (5) https://kivy.org

   (6) https://toga.readthedocs.io

   (7) https://beeware.org

   (8) https://wxpython.org


File: python.info,  Node: Advanced Topics,  Next: Other Resources,  Prev: GUI Programming,  Up: Using Python on macOS

3.5.5 Advanced Topics
---------------------

* Menu:

* Installing Free-threaded Binaries::
* Installing using the command line::
* Distributing Python Applications::
* App Store Compliance::


File: python.info,  Node: Installing Free-threaded Binaries,  Next: Installing using the command line,  Up: Advanced Topics

3.5.5.1 Installing Free-threaded Binaries
.........................................

Added in version 3.13.

The ‘python.org’ *note Python for macOS: 222d. installer package can
optionally install an additional build of Python 3.14 that supports PEP
703(1), the free-threading feature (running with the *note global
interpreter lock: 474. disabled).  Check the release page on
‘python.org’ for possible updated information.

The free-threaded mode is working and continues to be improved, but
there is some additional overhead in single-threaded workloads compared
to the regular build.  Additionally, third-party packages, in particular
ones with an *note extension module: 223a, may not be ready for use in a
free-threaded build, and will re-enable the *note GIL: 164.  Therefore,
the support for free-threading is not installed by default.  It is
packaged as a separate install option, available by clicking the
'Customize' button on the 'Installation Type' step of the installer as
described above.

[image src="python-figures/mac_installer_09_custom_install_free_threaded.png"]


If the box next to the 'Free-threaded Python' package name is checked, a
separate ‘PythonT.framework’ will also be installed alongside the normal
‘Python.framework’ in ‘/Library/Frameworks’.  This configuration allows
a free-threaded Python 3.14 build to co-exist on your system with a
traditional (GIL only) Python 3.14 build with minimal risk while
installing or testing.  This installation layout may change in future
releases.

Known cautions and limitations:

   - The 'UNIX command-line tools' package, which is selected by
     default, will install links in ‘/usr/local/bin’ for ‘python3.14t’,
     the free-threaded interpreter, and ‘python3.14t-config’, a
     configuration utility which may be useful for package builders.
     Since ‘/usr/local/bin’ is typically included in your shell ‘PATH’,
     in most cases no changes to your ‘PATH’ environment variables
     should be needed to use ‘python3.14t’.

   - For this release, the 'Shell profile updater' package and the
     ‘Update Shell Profile.command’ in ‘/Applications/Python 3.14/’ do
     not support the free-threaded package.

   - The free-threaded build and the traditional build have separate
     search paths and separate ‘site-packages’ directories so, by
     default, if you need a package available in both builds, it may
     need to be installed in both.  The free-threaded package will
     install a separate instance of ‘pip’ for use with ‘python3.14t’.

        - To install a package using ‘pip’ without a ‘venv’:

               python3.14t -m pip install <package_name>

   - When working with multiple Python environments, it is usually
     safest and easiest to *note create and use virtual environments:
     20d4.  This can avoid possible command name conflicts and confusion
     about which Python is in use:

          python3.14t -m venv <venv_name>

     then ‘activate’.

   - To run a free-threaded version of IDLE:

          python3.14t -m idlelib

   - The interpreters in both builds respond to the same *note PYTHON
     environment variables: 808. which may have unexpected results, for
     example, if you have ‘PYTHONPATH’ set in a shell profile.  If
     necessary, there are *note command line options: 2104. like ‘-E’ to
     ignore these environment variables.

   - The free-threaded build links to the third-party shared libraries,
     such as ‘OpenSSL’ and ‘Tk’, installed in the traditional framework.
     This means that both builds also share one set of trust
     certificates as installed by the ‘Install Certificates.command’
     script, thus it only needs to be run once.

   - If you cannot depend on the link in ‘/usr/local/bin’ pointing to
     the ‘python.org’ free-threaded ‘python3.14t’ (for example, if you
     want to install your own version there or some other distribution
     does), you can explicitly set your shell ‘PATH’ environment
     variable to include the ‘PythonT’ framework ‘bin’ directory:

          export PATH="/Library/Frameworks/PythonT.framework/Versions/3.14/bin":"$PATH"

     The traditional framework installation by default does something
     similar, except for ‘Python.framework’.  Be aware that having both
     framework ‘bin’ directories in ‘PATH’ can lead to confusion if
     there are duplicate names like ‘python3.14’ in both; which one is
     actually used depends on the order they appear in ‘PATH’.  The
     ‘which python3.x’ or ‘which python3.xt’ commands can show which
     path is being used.  Using virtual environments can help avoid such
     ambiguities.  Another option might be to create a shell ‘alias’ to
     the desired interpreter, like:

          alias py3.14="/Library/Frameworks/Python.framework/Versions/3.14/bin/python3.14"
          alias py3.14t="/Library/Frameworks/PythonT.framework/Versions/3.14/bin/python3.14t"

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0703/


File: python.info,  Node: Installing using the command line,  Next: Distributing Python Applications,  Prev: Installing Free-threaded Binaries,  Up: Advanced Topics

3.5.5.2 Installing using the command line
.........................................

If you want to use automation to install the ‘python.org’ installer
package (rather than by using the familiar macOS ‘Installer’ GUI app),
the macOS command line ‘installer’ utility lets you select non-default
options, too.  If you are not familiar with ‘installer’, it can be
somewhat cryptic (see ‘man installer’ for more information).  As an
example, the following shell snippet shows one way to do it, using the
‘3.14.0b2’ release and selecting the free-threaded interpreter option:

     RELEASE="python-3.140b2-macos11.pkg"

     # download installer pkg
     curl -O https://www.python.org/ftp/python/3.14.0/${RELEASE}

     # create installer choicechanges to customize the install:
     #    enable the PythonTFramework-3.14 package
     #    while accepting the other defaults (install all other packages)
     cat > ./choicechanges.plist <<EOF
     <?xml version="1.0" encoding="UTF-8"?>
     <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
     <plist version="1.0">
     <array>
             <dict>
                     <key>attributeSetting</key>
                     <integer>1</integer>
                     <key>choiceAttribute</key>
                     <string>selected</string>
                     <key>choiceIdentifier</key>
                     <string>org.python.Python.PythonTFramework-3.14</string>
             </dict>
     </array>
     </plist>
     EOF

     sudo installer -pkg ./${RELEASE} -applyChoiceChangesXML ./choicechanges.plist -target /

You can then test that both installer builds are now available with
something like:

     $ # test that the free-threaded interpreter was installed if the Unix Command Tools package was enabled
     $ /usr/local/bin/python3.14t -VV
     Python 3.14.0b2 free-threading build (v3.14.0b2:3a83b172af, Jun  5 2024, 12:57:31) [Clang 15.0.0 (clang-1500.3.9.4)]
     $ #    and the traditional interpreter
     $ /usr/local/bin/python3.14 -VV
     Python 3.14.0b2 (v3.14.0b2:3a83b172af, Jun  5 2024, 12:50:24) [Clang 15.0.0 (clang-1500.3.9.4)]
     $ # test that they are also available without the prefix if /usr/local/bin is on $PATH
     $ python3.14t -VV
     Python 3.14.0b2 free-threading build (v3.14.0b2:3a83b172af, Jun  5 2024, 12:57:31) [Clang 15.0.0 (clang-1500.3.9.4)]
     $ python3.14 -VV
     Python 3.14.0b2 (v3.14.0b2:3a83b172af, Jun  5 2024, 12:50:24) [Clang 15.0.0 (clang-1500.3.9.4)]

     Nota: Current ‘python.org’ installers only install to fixed
     locations like ‘/Library/Frameworks/’, ‘/Applications’, and
     ‘/usr/local/bin’.  You cannot use the ‘installer’ ‘-domain’ option
     to install to other locations.


File: python.info,  Node: Distributing Python Applications,  Next: App Store Compliance,  Prev: Installing using the command line,  Up: Advanced Topics

3.5.5.3 Distributing Python Applications
........................................

A range of tools exist for converting your Python code into a standalone
distributable application:

   * py2app(1): Supports creating macOS ‘.app’ bundles from a Python
     project.

   * Briefcase(2): Part of the BeeWare Project(3); a cross-platform
     packaging tool that supports creation of ‘.app’ bundles on macOS,
     as well as managing signing and notarization.

   * PyInstaller(4): A cross-platform packaging tool that creates a
     single file or folder as a distributable artifact.

   ---------- Footnotes ----------

   (1) https://pypi.org/project/py2app/

   (2) https://briefcase.readthedocs.io

   (3) https://beeware.org

   (4) https://pyinstaller.org/


File: python.info,  Node: App Store Compliance,  Prev: Distributing Python Applications,  Up: Advanced Topics

3.5.5.4 App Store Compliance
............................

Apps submitted for distribution through the macOS App Store must pass
Apple’s app review process.  This process includes a set of automated
validation rules that inspect the submitted application bundle for
problematic code.

The Python standard library contains some code that is known to violate
these automated rules.  While these violations appear to be false
positives, Apple’s review rules cannot be challenged.  Therefore, it is
necessary to modify the Python standard library for an app to pass App
Store review.

The Python source tree contains a patch file(1) that will remove all
code that is known to cause issues with the App Store review process.
This patch is applied automatically when CPython is configured with the
*note -with-app-store-compliance: 197f. option.

This patch is not normally required to use CPython on a Mac; nor is it
required if you are distributing an app 'outside' the macOS App Store.
It is 'only' required if you are using the macOS App Store as a
distribution channel.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Mac/Resources/app-store-compliance.patch


File: python.info,  Node: Other Resources,  Prev: Advanced Topics,  Up: Using Python on macOS

3.5.6 Other Resources
---------------------

The python.org Help page(1) has links to many useful resources.  The
Pythonmac-SIG mailing list(2) is another support resource specifically
for Python users and developers on the Mac.

   ---------- Footnotes ----------

   (1) https://www.python.org/about/help/

   (2) https://www.python.org/community/sigs/current/pythonmac-sig/


File: python.info,  Node: Using Python on Android,  Next: Using Python on iOS,  Prev: Using Python on macOS,  Up: Python Setup and Usage

3.6 Using Python on Android
===========================

Python on Android is unlike Python on desktop platforms.  On a desktop
platform, Python is generally installed as a system resource that can be
used by any user of that computer.  Users then interact with Python by
running a ‘python’ executable and entering commands at an interactive
prompt, or by running a Python script.

On Android, there is no concept of installing as a system resource.  The
only unit of software distribution is an «app».  There is also no
console where you could run a ‘python’ executable, or interact with a
Python REPL.

As a result, the only way you can use Python on Android is in embedded
mode – that is, by writing a native Android application, embedding a
Python interpreter using ‘libpython’, and invoking Python code using the
*note Python embedding API: 2244.  The full Python interpreter, the
standard library, and all your Python code is then packaged into your
app for its own private use.

The Python standard library has some notable omissions and restrictions
on Android.  See the *note API availability guide: 2245. for details.

* Menu:

* Adding Python to an Android app::
* Building a Python package for Android::


File: python.info,  Node: Adding Python to an Android app,  Next: Building a Python package for Android,  Up: Using Python on Android

3.6.1 Adding Python to an Android app
-------------------------------------

Most app developers should use one of the following tools, which will
provide a much easier experience:

   * Briefcase(1), from the BeeWare project

   * Buildozer(2), from the Kivy project

   * Chaquopy(3)

   * pyqtdeploy(4)

   * Termux(5)

If you’re sure you want to do all of this manually, read on.  You can
use the testbed app(6) as a guide; each step below contains a link to
the relevant file.

   * First, acquire a build of Python for Android:

        * The easiest way is to download an Android release from
          python.org(7).  The ‘prefix’ directory mentioned below is at
          the top level of the package.

        * Or if you want to build it yourself, follow the instructions
          in Android/README.md(8).  The ‘prefix’ directory will be
          created under ‘cross-build/HOST’.

   * Add code to your build.gradle(9) file to copy the following items
     into your project.  All except your own Python code can be copied
     from ‘prefix/lib’:

        * In your JNI libraries:

             * ‘libpython*.*.so’

             * ‘lib*_python.so’ (external libraries such as OpenSSL)

        * In your assets:

             * ‘python*.*’ (the Python standard library)

             * ‘python*.*/site-packages’ (your own Python code)

   * Add code to your app to extract the assets to the filesystem(10).

   * Add code to your app to start Python in embedded mode(11).  This
     will need to be C code called via JNI.

   ---------- Footnotes ----------

   (1) https://briefcase.readthedocs.io

   (2) https://buildozer.readthedocs.io

   (3) https://chaquo.com/chaquopy

   (4) https://www.riverbankcomputing.com/static/Docs/pyqtdeploy/

   (5) https://termux.dev/en/

   (6) https://github.com/python/cpython/tree/3.14/Android/testbed

   (7) https://www.python.org/downloads/android/

   (8) https://github.com/python/cpython/tree/3.14/Android/README.md

   (9) 
https://github.com/python/cpython/tree/3.14/Android/testbed/app/build.gradle.kts

   (10) 
https://github.com/python/cpython/tree/3.14/Android/testbed/app/src/main/java/org/python/testbed/MainActivity.kt

   (11) 
https://github.com/python/cpython/tree/3.14/Android/testbed/app/src/main/c/main_activity.c


File: python.info,  Node: Building a Python package for Android,  Prev: Adding Python to an Android app,  Up: Using Python on Android

3.6.2 Building a Python package for Android
-------------------------------------------

Python packages can be built for Android as wheels and released on PyPI.
The recommended tool for doing this is cibuildwheel(1), which automates
all the details of setting up a cross-compilation environment, building
the wheel, and testing it on an emulator.

   ---------- Footnotes ----------

   (1) https://cibuildwheel.pypa.io/en/stable/platforms/#android


File: python.info,  Node: Using Python on iOS,  Next: Editors and IDEs,  Prev: Using Python on Android,  Up: Python Setup and Usage

3.7 Using Python on iOS
=======================


Authors: Russell Keith-Magee (2024-03)

Python on iOS is unlike Python on desktop platforms.  On a desktop
platform, Python is generally installed as a system resource that can be
used by any user of that computer.  Users then interact with Python by
running a ‘python’ executable and entering commands at an interactive
prompt, or by running a Python script.

On iOS, there is no concept of installing as a system resource.  The
only unit of software distribution is an «app».  There is also no
console where you could run a ‘python’ executable, or interact with a
Python REPL.

As a result, the only way you can use Python on iOS is in embedded mode
- that is, by writing a native iOS application, and embedding a Python
interpreter using ‘libPython’, and invoking Python code using the *note
Python embedding API: 2244.  The full Python interpreter, the standard
library, and all your Python code is then packaged as a standalone
bundle that can be distributed via the iOS App Store.

If you’re looking to experiment for the first time with writing an iOS
app in Python, projects such as BeeWare(1) and Kivy(2) will provide a
much more approachable user experience.  These projects manage the
complexities associated with getting an iOS project running, so you only
need to deal with the Python code itself.

* Menu:

* Python at runtime on iOS::
* Installing Python on iOS::
* App Store Compliance: App Store Compliance<2>.

   ---------- Footnotes ----------

   (1) https://beeware.org

   (2) https://kivy.org


File: python.info,  Node: Python at runtime on iOS,  Next: Installing Python on iOS,  Up: Using Python on iOS

3.7.1 Python at runtime on iOS
------------------------------

* Menu:

* iOS version compatibility::
* Platform identification::
* Standard library availability::
* Binary extension modules::
* Compiler stub binaries::


File: python.info,  Node: iOS version compatibility,  Next: Platform identification,  Up: Python at runtime on iOS

3.7.1.1 iOS version compatibility
.................................

The minimum supported iOS version is specified at compile time, using
the *note -host: 21ad. option to ‘configure’.  By default, when compiled
for iOS, Python will be compiled with a minimum supported iOS version of
13.0.  To use a different minimum iOS version, provide the version
number as part of the ‘--host’ argument - for example,
‘--host=arm64-apple-ios15.4-simulator’ would compile an ARM64 simulator
build with a deployment target of 15.4.


File: python.info,  Node: Platform identification,  Next: Standard library availability,  Prev: iOS version compatibility,  Up: Python at runtime on iOS

3.7.1.2 Platform identification
...............................

When executing on iOS, ‘sys.platform’ will report as ‘ios’.  This value
will be returned on an iPhone or iPad, regardless of whether the app is
running on the simulator or a physical device.

Information about the specific runtime environment, including the iOS
version, device model, and whether the device is a simulator, can be
obtained using *note platform.ios_ver(): 224f.  *note platform.system():
2250. will report ‘iOS’ or ‘iPadOS’, depending on the device.

*note os.uname(): 131e. reports kernel-level details; it will report a
name of ‘Darwin’.


File: python.info,  Node: Standard library availability,  Next: Binary extension modules,  Prev: Platform identification,  Up: Python at runtime on iOS

3.7.1.3 Standard library availability
.....................................

The Python standard library has some notable omissions and restrictions
on iOS. See the *note API availability guide for iOS: 2245. for details.


File: python.info,  Node: Binary extension modules,  Next: Compiler stub binaries,  Prev: Standard library availability,  Up: Python at runtime on iOS

3.7.1.4 Binary extension modules
................................

One notable difference about iOS as a platform is that App Store
distribution imposes hard requirements on the packaging of an
application.  One of these requirements governs how binary extension
modules are distributed.

The iOS App Store requires that 'all' binary modules in an iOS app must
be dynamic libraries, contained in a framework with appropriate
metadata, stored in the ‘Frameworks’ folder of the packaged app.  There
can be only a single binary per framework, and there can be no
executable binary material outside the ‘Frameworks’ folder.

This conflicts with the usual Python approach for distributing binaries,
which allows a binary extension module to be loaded from any location on
‘sys.path’.  To ensure compliance with App Store policies, an iOS
project must post-process any Python packages, converting ‘.so’ binary
modules into individual standalone frameworks with appropriate metadata
and signing.  For details on how to perform this post-processing, see
the guide for *note adding Python to your project: 2253.

To help Python discover binaries in their new location, the original
‘.so’ file on ‘sys.path’ is replaced with a ‘.fwork’ file.  This file is
a text file containing the location of the framework binary, relative to
the app bundle.  To allow the framework to resolve back to the original
location, the framework must contain a ‘.origin’ file that contains the
location of the ‘.fwork’ file, relative to the app bundle.

For example, consider the case of an import ‘from foo.bar import _whiz’,
where ‘_whiz’ is implemented with the binary module
‘sources/foo/bar/_whiz.abi3.so’, with ‘sources’ being the location
registered on ‘sys.path’, relative to the application bundle.  This
module 'must' be distributed as
‘Frameworks/foo.bar._whiz.framework/foo.bar._whiz’ (creating the
framework name from the full import path of the module), with an
‘Info.plist’ file in the ‘.framework’ directory identifying the binary
as a framework.  The ‘foo.bar._whiz’ module would be represented in the
original location with a ‘sources/foo/bar/_whiz.abi3.fwork’ marker file,
containing the path ‘Frameworks/foo.bar._whiz/foo.bar._whiz’.  The
framework would also contain
‘Frameworks/foo.bar._whiz.framework/foo.bar._whiz.origin’, containing
the path to the ‘.fwork’ file.

When running on iOS, the Python interpreter will install an *note
AppleFrameworkLoader: 2254. that is able to read and import ‘.fwork’
files.  Once imported, the ‘__file__’ attribute of the binary module
will report as the location of the ‘.fwork’ file.  However, the *note
ModuleSpec: 2255. for the loaded module will report the ‘origin’ as the
location of the binary in the framework folder.


File: python.info,  Node: Compiler stub binaries,  Prev: Binary extension modules,  Up: Python at runtime on iOS

3.7.1.5 Compiler stub binaries
..............................

Xcode doesn’t expose explicit compilers for iOS; instead, it uses an
‘xcrun’ script that resolves to a full compiler path (e.g., ‘xcrun --sdk
iphoneos clang’ to get the ‘clang’ for an iPhone device).  However,
using this script poses two problems:

   * The output of ‘xcrun’ includes paths that are machine specific,
     resulting in a sysconfig module that cannot be shared between
     users; and

   * It results in ‘CC’/‘CPP’/‘LD’/‘AR’ definitions that include spaces.
     There is a lot of C ecosystem tooling that assumes that you can
     split a command line at the first space to get the path to the
     compiler executable; this isn’t the case when using ‘xcrun’.

To avoid these problems, Python provided stubs for these tools.  These
stubs are shell script wrappers around the underingly ‘xcrun’ tools,
distributed in a ‘bin’ folder distributed alongside the compiled iOS
framework.  These scripts are relocatable, and will always resolve to
the appropriate local system paths.  By including these scripts in the
bin folder that accompanies a framework, the contents of the ‘sysconfig’
module becomes useful for end-users to compile their own modules.  When
compiling third-party Python modules for iOS, you should ensure these
stub binaries are on your path.


File: python.info,  Node: Installing Python on iOS,  Next: App Store Compliance<2>,  Prev: Python at runtime on iOS,  Up: Using Python on iOS

3.7.2 Installing Python on iOS
------------------------------

* Menu:

* Tools for building iOS apps::
* Adding Python to an iOS project::
* Testing a Python package::


File: python.info,  Node: Tools for building iOS apps,  Next: Adding Python to an iOS project,  Up: Installing Python on iOS

3.7.2.1 Tools for building iOS apps
...................................

Building for iOS requires the use of Apple’s Xcode tooling.  It is
strongly recommended that you use the most recent stable release of
Xcode.  This will require the use of the most (or second-most) recently
released macOS version, as Apple does not maintain Xcode for older macOS
versions.  The Xcode Command Line Tools are not sufficient for iOS
development; you need a 'full' Xcode install.

If you want to run your code on the iOS simulator, you’ll also need to
install an iOS Simulator Platform.  You should be prompted to select an
iOS Simulator Platform when you first run Xcode.  Alternatively, you can
add an iOS Simulator Platform by selecting from the Platforms tab of the
Xcode Settings panel.


File: python.info,  Node: Adding Python to an iOS project,  Next: Testing a Python package,  Prev: Tools for building iOS apps,  Up: Installing Python on iOS

3.7.2.2 Adding Python to an iOS project
.......................................

Python can be added to any iOS project, using either Swift or Objective
C. The following examples will use Objective C; if you are using Swift,
you may find a library like PythonKit(1) to be helpful.

To add Python to an iOS Xcode project:

  1. Build or obtain a Python ‘XCFramework’.  See the instructions in
     Apple/iOS/README.md(2) (in the CPython source distribution) for
     details on how to build a Python ‘XCFramework’.  At a minimum, you
     will need a build that supports ‘arm64-apple-ios’, plus one of
     either ‘arm64-apple-ios-simulator’ or ‘x86_64-apple-ios-simulator’.

  2. Drag the ‘XCframework’ into your iOS project.  In the following
     instructions, we’ll assume you’ve dropped the ‘XCframework’ into
     the root of your project; however, you can use any other location
     that you want by adjusting paths as needed.

  3. Add your application code as a folder in your Xcode project.  In
     the following instructions, we’ll assume that your user code is in
     a folder named ‘app’ in the root of your project; you can use any
     other location by adjusting paths as needed.  Ensure that this
     folder is associated with your app target.

  4. Select the app target by selecting the root node of your Xcode
     project, then the target name in the sidebar that appears.

  5. In the «General» settings, under «Frameworks, Libraries and
     Embedded Content», add ‘Python.xcframework’, with «Embed & Sign»
     selected.

  6. In the «Build Settings» tab, modify the following:

        - Build Options

             * User Script Sandboxing: No

             * Enable Testability: Yes

        - Search Paths

             * Framework Search Paths: ‘$(PROJECT_DIR)’

             * Header Search Paths:
               ‘"$(BUILT_PRODUCTS_DIR)/Python.framework/Headers"’

        - Apple Clang - Warnings - All languages

             * Quoted Include In Framework Header: No

  7. Add a build step that processes the Python standard library, and
     your own Python binary dependencies.  In the «Build Phases» tab,
     add a new «Run Script» build step 'before' the «Embed Frameworks»
     step, but 'after' the «Copy Bundle Resources» step.  Name the step
     «Process Python libraries», disable the «Based on dependency
     analysis» checkbox, and set the script content to:

          set -e
          source $PROJECT_DIR/Python.xcframework/build/build_utils.sh
          install_python Python.xcframework app

     If you have placed your XCframework somewhere other than the root
     of your project, modify the path to the first argument.

  8. Add Objective C code to initialize and use a Python interpreter in
     embedded mode.  You should ensure that:

        * UTF-8 mode (*note PyPreConfig.utf8_mode: 41d.) is 'enabled';

        * Buffered stdio (*note PyConfig.buffered_stdio: 411.) is
          'disabled';

        * Writing bytecode (*note PyConfig.write_bytecode: 40d.) is
          'disabled';

        * Signal handlers (*note PyConfig.install_signal_handlers: abd.)
          are 'enabled';

        * System logging (*note PyConfig.use_system_logger: 225a.) is
          'enabled' (optional, but strongly recommended; this is enabled
          by default);

        * *note PYTHONHOME: 3f0. for the interpreter is configured to
          point at the ‘python’ subfolder of your app’s bundle; and

        * The *note PYTHONPATH: 121f. for the interpreter includes:

             - the ‘python/lib/python3.X’ subfolder of your app’s
               bundle,

             - the ‘python/lib/python3.X/lib-dynload’ subfolder of your
               app’s bundle, and

             - the ‘app’ subfolder of your app’s bundle

     Your app’s bundle location can be determined using ‘[[NSBundle
     mainBundle] resourcePath]’.

Steps 7 and 8 of these instructions assume that you have a single folder
of pure Python application code, named ‘app’.  If you have third-party
binary modules in your app, some additional steps will be required:

   * You need to ensure that any folders containing third-party binaries
     are either associated with the app target, or are explicitly copied
     as part of step 7.  Step 7 should also purge any binaries that are
     not appropriate for the platform a specific build is targeting
     (i.e., delete any device binaries if you’re building an app
     targeting the simulator).

   * If you’re using a separate folder for third-party packages, ensure
     that folder is added to the end of the call to ‘install_python’ in
     step 7, and as part of the *note PYTHONPATH: 121f. configuration in
     step 8.

   * If any of the folders that contain third-party packages will
     contain ‘.pth’ files, you should add that folder as a 'site
     directory' (using *note site.addsitedir(): 225b.), rather than
     adding to *note PYTHONPATH: 121f. or *note sys.path: 3e4. directly.

   ---------- Footnotes ----------

   (1) https://github.com/pvieito/PythonKit

   (2) https://github.com/python/cpython/tree/3.14/Apple/iOS/README.md


File: python.info,  Node: Testing a Python package,  Prev: Adding Python to an iOS project,  Up: Installing Python on iOS

3.7.2.3 Testing a Python package
................................

The CPython source tree contains a testbed project(1) that is used to
run the CPython test suite on the iOS simulator.  This testbed can also
be used as a testbed project for running your Python library’s test
suite on iOS.

After building or obtaining an iOS XCFramework (see
Apple/iOS/README.md(2) for details), create a clone of the Python iOS
testbed project.  If you used the ‘Apple’ build script to build the
XCframework, you can run:

     $ python cross-build/iOS/testbed clone --app <path/to/module1> --app <path/to/module2> app-testbed

Or, if you’ve sourced your own XCframework, by running:

     $ python Apple/testbed clone --platform iOS --framework <path/to/Python.xcframework> --app <path/to/module1> --app <path/to/module2> app-testbed

Any folders specified with the ‘--app’ flag will be copied into the
cloned testbed project.  The resulting testbed will be created in the
‘app-testbed’ folder.  In this example, the ‘module1’ and ‘module2’
would be importable modules at runtime.  If your project has additional
dependencies, they can be installed into the
‘app-testbed/Testbed/app_packages’ folder (using ‘pip install --target
app-testbed/Testbed/app_packages’ or similar).

You can then use the ‘app-testbed’ folder to run the test suite for your
app, For example, if ‘module1.tests’ was the entry point to your test
suite, you could run:

     $ python app-testbed run -- module1.tests

This is the equivalent of running ‘python -m module1.tests’ on a desktop
Python build.  Any arguments after the ‘--’ will be passed to the
testbed as if they were arguments to ‘python -m’ on a desktop machine.

You can also open the testbed project in Xcode by running:

     $ open app-testbed/iOSTestbed.xcodeproj

This will allow you to use the full Xcode suite of tools for debugging.

The arguments used to run the test suite are defined as part of the test
plan.  To modify the test plan, select the test plan node of the project
tree (it should be the first child of the root node), and select the
«Configurations» tab.  Modify the «Arguments Passed On Launch» value to
change the testing arguments.

The test plan also disables parallel testing, and specifies the use of
the ‘Testbed.lldbinit’ file for providing configuration of the debugger.
The default debugger configuration disables automatic breakpoints on the
‘SIGINT’, ‘SIGUSR1’, ‘SIGUSR2’, and ‘SIGXFSZ’ signals.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Apple/iOS/testbed

   (2) https://github.com/python/cpython/tree/3.14/Apple/iOS/README.md


File: python.info,  Node: App Store Compliance<2>,  Prev: Installing Python on iOS,  Up: Using Python on iOS

3.7.3 App Store Compliance
--------------------------

The only mechanism for distributing apps to third-party iOS devices is
to submit the app to the iOS App Store; apps submitted for distribution
must pass Apple’s app review process.  This process includes a set of
automated validation rules that inspect the submitted application bundle
for problematic code.  There are some steps that must be taken to ensure
that your app will be able to pass these validation steps.

* Menu:

* Incompatible code in the standard library::
* Privacy manifests::


File: python.info,  Node: Incompatible code in the standard library,  Next: Privacy manifests,  Up: App Store Compliance<2>

3.7.3.1 Incompatible code in the standard library
.................................................

The Python standard library contains some code that is known to violate
these automated rules.  While these violations appear to be false
positives, Apple’s review rules cannot be challenged; so, it is
necessary to modify the Python standard library for an app to pass App
Store review.

The Python source tree contains a patch file(1) that will remove all
code that is known to cause issues with the App Store review process.
This patch is applied automatically when building for iOS.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Mac/Resources/app-store-compliance.patch


File: python.info,  Node: Privacy manifests,  Prev: Incompatible code in the standard library,  Up: App Store Compliance<2>

3.7.3.2 Privacy manifests
.........................

In April 2025, Apple introduced a requirement for certain third-party
libraries to provide a Privacy Manifest(1).  As a result, if you have a
binary module that uses one of the affected libraries, you must provide
an ‘.xcprivacy’ file for that library.  OpenSSL is one library affected
by this requirement, but there are others.

If you produce a binary module named ‘mymodule.so’, and use you the
Xcode build script described in step 7 above, you can place a
‘mymodule.xcprivacy’ file next to ‘mymodule.so’, and the privacy
manifest will be installed into the required location when the binary
module is converted into a framework.

   ---------- Footnotes ----------

   (1) https://developer.apple.com/support/third-party-SDK-requirements


File: python.info,  Node: Editors and IDEs,  Prev: Using Python on iOS,  Up: Python Setup and Usage

3.8 Editors and IDEs
====================

There are a number of IDEs that support Python programming language.
Many editors and IDEs provide syntax highlighting, debugging tools, and
PEP 8(1) checks.

* Menu:

* IDLE — Python editor and shell::
* Other Editors and IDEs::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0008/


File: python.info,  Node: IDLE — Python editor and shell,  Next: Other Editors and IDEs,  Up: Editors and IDEs

3.8.1 IDLE — Python editor and shell
------------------------------------

IDLE is Python’s Integrated Development and Learning Environment and is
generally bundled with Python installs.  If you are on Linux and do not
have IDLE installed see *note Installing IDLE on Linux: 2132.  For more
information see the *note IDLE docs: 1217.


File: python.info,  Node: Other Editors and IDEs,  Prev: IDLE — Python editor and shell,  Up: Editors and IDEs

3.8.2 Other Editors and IDEs
----------------------------

Python’s community wiki has information submitted by the community on
Editors and IDEs.  Please go to Python Editors(1) and Integrated
Development Environments(2) for a comprehensive list.

   ---------- Footnotes ----------

   (1) https://wiki.python.org/moin/PythonEditors

   (2) https://wiki.python.org/moin/IntegratedDevelopmentEnvironments


File: python.info,  Node: The Python Language Reference,  Next: The Python Standard Library,  Prev: Python Setup and Usage,  Up: Top

4 The Python Language Reference
*******************************

This reference manual describes the syntax and «core semantics» of the
language.  It is terse, but attempts to be exact and complete.  The
semantics of non-essential built-in object types and of the built-in
functions and modules are described in *note The Python Standard
Library: 149.  For an informal introduction to the language, see *note
Tutorial su Python: 1fa4.  For C or C++ programmers, two additional
manuals exist: *note Extending and Embedding the Python Interpreter:
1fa5. describes the high-level picture of how to write a Python
extension module, and the *note Python/C API Reference Manual: 1fa6.
describes the interfaces available to C/C++ programmers in detail.

* Menu:

* Introduction: Introduction<4>.
* Lexical analysis::
* Data model::
* Execution model::
* The import system::
* Expressions::
* Simple statements::
* Compound statements::
* Top-level components::
* Full Grammar specification::


File: python.info,  Node: Introduction<4>,  Next: Lexical analysis,  Up: The Python Language Reference

4.1 Introduction
================

This reference manual describes the Python programming language.  It is
not intended as a tutorial.

While I am trying to be as precise as possible, I chose to use English
rather than formal specifications for everything except syntax and
lexical analysis.  This should make the document more understandable to
the average reader, but will leave room for ambiguities.  Consequently,
if you were coming from Mars and tried to re-implement Python from this
document alone, you might have to guess things and in fact you would
probably end up implementing quite a different language.  On the other
hand, if you are using Python and wonder what the precise rules about a
particular area of the language are, you should definitely be able to
find them here.  If you would like to see a more formal definition of
the language, maybe you could volunteer your time — or invent a cloning
machine :-).

It is dangerous to add too many implementation details to a language
reference document — the implementation may change, and other
implementations of the same language may work differently.  On the other
hand, CPython is the one Python implementation in widespread use
(although alternate implementations continue to gain support), and its
particular quirks are sometimes worth being mentioned, especially where
the implementation imposes additional limitations.  Therefore, you’ll
find short «implementation notes» sprinkled throughout the text.

Every Python implementation comes with a number of built-in and standard
modules.  These are documented in *note The Python Standard Library:
149.  A few built-in modules are mentioned when they interact in a
significant way with the language definition.

* Menu:

* Alternate Implementations::
* Notation::


File: python.info,  Node: Alternate Implementations,  Next: Notation,  Up: Introduction<4>

4.1.1 Alternate Implementations
-------------------------------

Though there is one Python implementation which is by far the most
popular, there are some alternate implementations which are of
particular interest to different audiences.

Known implementations include:

CPython

     This is the original and most-maintained implementation of Python,
     written in C. New language features generally appear here first.

Jython

     Python implemented in Java.  This implementation can be used as a
     scripting language for Java applications, or can be used to create
     applications using the Java class libraries.  It is also often used
     to create tests for Java libraries.  More information can be found
     at the Jython website(1).

Python for .NET

     This implementation actually uses the CPython implementation, but
     is a managed .NET application and makes .NET libraries available.
     It was created by Brian Lloyd.  For more information, see the
     Python for .NET home page(2).

IronPython

     An alternate Python for .NET. Unlike Python.NET, this is a complete
     Python implementation that generates IL, and compiles Python code
     directly to .NET assemblies.  It was created by Jim Hugunin, the
     original creator of Jython.  For more information, see the
     IronPython website(3).

PyPy

     An implementation of Python written completely in Python.  It
     supports several advanced features not found in other
     implementations like stackless support and a Just in Time compiler.
     One of the goals of the project is to encourage experimentation
     with the language itself by making it easier to modify the
     interpreter (since it is written in Python).  Additional
     information is available on the PyPy project's home page(4).

Each of these implementations varies in some way from the language as
documented in this manual, or introduces specific information beyond
what’s covered in the standard Python documentation.  Please refer to
the implementation-specific documentation to determine what else you
need to know about the specific implementation you’re using.

   ---------- Footnotes ----------

   (1) https://www.jython.org/

   (2) https://pythonnet.github.io/

   (3) https://ironpython.net/

   (4) https://pypy.org/


File: python.info,  Node: Notation,  Prev: Alternate Implementations,  Up: Introduction<4>

4.1.2 Notation
--------------

The descriptions of lexical analysis and syntax use a grammar notation
that is a mixture of EBNF(1) and PEG(2). For example:

     name:   *note letter: 226f. (*note letter: 226f. | *note digit: 2270. | "_")*
     letter: "a"..."z" | "A"..."Z"
     digit:  "0"..."9"

In this example, the first line says that a ‘name’ is a ‘letter’
followed by a sequence of zero or more ‘letter’s, ‘digit’s, and
underscores.  A ‘letter’ in turn is any of the single characters ‘'a'’
through ‘'z'’ and ‘A’ through ‘Z’; a ‘digit’ is a single character from
‘0’ to ‘9’.

Each rule begins with a name (which identifies the rule that’s being
defined) followed by a colon, ‘:’.  The definition to the right of the
colon uses the following syntax elements:

   * ‘name’: A name refers to another rule.  Where possible, it is a
     link to the rule’s definition.

        * ‘TOKEN’: An uppercase name refers to a *note token: 2271.  For
          the purposes of grammar definitions, tokens are the same as
          rules.

   * ‘"text"’, ‘'text'’: Text in single or double quotes must match
     literally (without the quotes).  The type of quote is chosen
     according to the meaning of ‘text’:

        * ‘'if'’: A name in single quotes denotes a *note keyword: 2272.

        * ‘"case"’: A name in double quotes denotes a *note
          soft-keyword: a0f.

        * ‘'@'’: A non-letter symbol in single quotes denotes an *note
          OP: 2273. token, that is, a *note delimiter: 2274. or *note
          operator: 2275.

   * ‘e1 e2’: Items separated only by whitespace denote a sequence.
     Here, ‘e1’ must be followed by ‘e2’.

   * ‘e1 | e2’: A vertical bar is used to separate alternatives.  It
     denotes PEG’s «ordered choice»: if ‘e1’ matches, ‘e2’ is not
     considered.  In traditional PEG grammars, this is written as a
     slash, ‘/’, rather than a vertical bar.  See PEP 617(3) for more
     background and details.

   * ‘e*’: A star means zero or more repetitions of the preceding item.

   * ‘e+’: Likewise, a plus means one or more repetitions.

   * ‘[e]’: A phrase enclosed in square brackets means zero or one
     occurrences.  In other words, the enclosed phrase is optional.

   * ‘e?’: A question mark has exactly the same meaning as square
     brackets: the preceding item is optional.

   * ‘(e)’: Parentheses are used for grouping.

The following notation is only used in *note lexical definitions: 2276.

   * ‘"a"..."z"’: Two literal characters separated by three dots mean a
     choice of any single character in the given (inclusive) range of
     ASCII characters.

   * ‘<...>’: A phrase between angular brackets gives an informal
     description of the matched symbol (for example, ‘<any ASCII
     character except "\">’), or an abbreviation that is defined in
     nearby text (for example, ‘<Lu>’).
Some definitions also use 'lookaheads', which indicate that an element
must (or must not) match at a given position, but without consuming any
input:

   * ‘&e’: a positive lookahead (that is, ‘e’ is required to match)

   * ‘!e’: a negative lookahead (that is, ‘e’ is required 'not' to
     match)

The unary operators (‘*’, ‘+’, ‘?’) bind as tightly as possible; the
vertical bar (‘|’) binds most loosely.

White space is only meaningful to separate tokens.

Rules are normally contained on a single line, but rules that are too
long may be wrapped:

     literal: stringliteral | bytesliteral
              | integer | floatnumber | imagnumber

Alternatively, rules may be formatted with the first line ending at the
colon, and each alternative beginning with a vertical bar on a new line.
For example:

     literal:
        | stringliteral
        | bytesliteral
        | integer
        | floatnumber
        | imagnumber

This does 'not' mean that there is an empty first alternative.

* Menu:

* Lexical and Syntactic definitions::

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Extended_Backus%E2%80%93Naur_form

   (2) https://en.wikipedia.org/wiki/Parsing_expression_grammar

   (3) https://peps.python.org/pep-0617/


File: python.info,  Node: Lexical and Syntactic definitions,  Up: Notation

4.1.2.1 Lexical and Syntactic definitions
.........................................

There is some difference between 'lexical' and 'syntactic' analysis: the
*note lexical analyzer: 227b. operates on the individual characters of
the input source, while the 'parser' (syntactic analyzer) operates on
the stream of *note tokens: 2271. generated by the lexical analysis.
However, in some cases the exact boundary between the two phases is a
CPython implementation detail.

The practical difference between the two is that in 'lexical'
definitions, all whitespace is significant.  The lexical analyzer *note
discards: 227c. all whitespace that is not converted to tokens like
*note token.INDENT: 20e6. or *note NEWLINE: 227d.  'Syntactic'
definitions then use these tokens, rather than source characters.

This documentation uses the same BNF grammar for both styles of
definitions.  All uses of BNF in the next chapter (*note Lexical
analysis: 227e.) are lexical definitions; uses in subsequent chapters
are syntactic definitions.


File: python.info,  Node: Lexical analysis,  Next: Data model,  Prev: Introduction<4>,  Up: The Python Language Reference

4.2 Lexical analysis
====================

A Python program is read by a 'parser'.  Input to the parser is a stream
of *note tokens: 2271, generated by the 'lexical analyzer' (also known
as the 'tokenizer').  This chapter describes how the lexical analyzer
produces these tokens.

The lexical analyzer determines the program text’s *note encoding: 2282.
(UTF-8 by default), and decodes the text into *note source characters:
2283.  If the text cannot be decoded, a *note SyntaxError: 18e. is
raised.

Next, the lexical analyzer uses the source characters to generate a
stream of tokens.  The type of a generated token generally depends on
the next source character to be processed.  Similarly, other special
behavior of the analyzer depends on the first source character that
hasn’t yet been processed.  The following table gives a quick summary of
these source characters, with links to sections that contain more
information.

Character                                              Next token (or other relevant documentation)
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
   * space                                                * *note Whitespace: 227c.
                                                       
   * tab

   * formfeed

   * CR, LF                                               * *note New line: 2284.
                                                       
                                                          * *note Indentation: 2285.
                                                       
                                                       
   * backslash (‘\’)                                      * *note Explicit line joining: 2286.
                                                       
                                                          * (Also significant in
                                                            *note string escape sequences: 688.)
                                                       
                                                       
   * hash (‘#’)                                           * *note Comment: 2287.
                                                       
                                                       
   * quote (‘'’, ‘"’)                                     * *note String literal: 2288.
                                                       
                                                       
   * ASCII letter (‘a’-‘z’, ‘A’-‘Z’)                      * *note Name: 2289.
                                                       
   * non-ASCII character                                  * Prefixed *note string or bytes literal: 2288.
                                                       
                                                       
   * underscore (‘_’)                                     * *note Name: 2289.
                                                       
                                                          * (Can also be part of
                                                            *note numeric literals: 228a.)
                                                       
                                                       
   * number (‘0’-‘9’)                                     * *note Numeric literal: 228a.
                                                       
                                                       
   * dot (‘.’)                                            * *note Numeric literal: 228a.
                                                       
                                                          * *note Operator: 2275.
                                                       
                                                       
   * question mark (‘?’)                                  * Error (outside string literals and comments)
                                                       
   * dollar (‘$’)

   * 
     backquote (‘​`​’)

   * control character

   * other printing character                             * *note Operator or delimiter: 2275.
                                                       
                                                       
   * end of file                                          * *note End marker: 228b.
                                                       

* Menu:

* Line structure::
* Other tokens::
* Names (identifiers and keywords): Names identifiers and keywords.
* Literals::
* String and Bytes literals::
* Numeric literals::
* Operators and delimiters::


File: python.info,  Node: Line structure,  Next: Other tokens,  Up: Lexical analysis

4.2.1 Line structure
--------------------

A Python program is divided into a number of 'logical lines'.

* Menu:

* Logical lines::
* Physical lines::
* Comments::
* Encoding declarations::
* Explicit line joining::
* Implicit line joining::
* Blank lines::
* Indentation::
* Whitespace between tokens::
* End marker::


File: python.info,  Node: Logical lines,  Next: Physical lines,  Up: Line structure

4.2.1.1 Logical lines
.....................

The end of a logical line is represented by the token *note NEWLINE:
227d.  Statements cannot cross logical line boundaries except where
‘NEWLINE’ is allowed by the syntax (e.g., between statements in compound
statements).  A logical line is constructed from one or more 'physical
lines' by following the *note explicit: 2286. or *note implicit: 228f.
'line joining' rules.


File: python.info,  Node: Physical lines,  Next: Comments,  Prev: Logical lines,  Up: Line structure

4.2.1.2 Physical lines
......................

A physical line is a sequence of characters terminated by one the
following end-of-line sequences:

   * the Unix form using ASCII LF (linefeed),

   * the Windows form using the ASCII sequence CR LF (return followed by
     linefeed),

   * the “Classic Mac OS(1)” form using the ASCII CR (return) character.

Regardless of platform, each of these sequences is replaced by a single
ASCII LF (linefeed) character.  (This is done even inside *note string
literals: 2288.)  Each line can use any of the sequences; they do not
need to be consistent within a file.

The end of input also serves as an implicit terminator for the final
physical line.

Formally:

     newline: <ASCII LF> | <ASCII CR> <ASCII LF> | <ASCII CR>

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Classic_Mac_OS


File: python.info,  Node: Comments,  Next: Encoding declarations,  Prev: Physical lines,  Up: Line structure

4.2.1.3 Comments
................

A comment starts with a hash character (‘#’) that is not part of a
string literal, and ends at the end of the physical line.  A comment
signifies the end of the logical line unless the implicit line joining
rules are invoked.  Comments are ignored by the syntax.


File: python.info,  Node: Encoding declarations,  Next: Explicit line joining,  Prev: Comments,  Up: Line structure

4.2.1.4 Encoding declarations
.............................

If a comment in the first or second line of the Python script matches
the regular expression ‘coding[=:]\s*([-\w.]+)’, this comment is
processed as an encoding declaration; the first group of this expression
names the encoding of the source code file.  The encoding declaration
must appear on a line of its own.  If it is the second line, the first
line must also be a comment-only line.  The recommended forms of an
encoding expression are

     # -*- coding: <encoding-name> -*-

which is recognized also by GNU Emacs, and

     # vim:fileencoding=<encoding-name>

which is recognized by Bram Moolenaar’s VIM.

If no encoding declaration is found, the default encoding is UTF-8.  If
the implicit or explicit encoding of a file is UTF-8, an initial UTF-8
byte-order mark (‘b'\xef\xbb\xbf'’) is ignored rather than being a
syntax error.

If an encoding is declared, the encoding name must be recognized by
Python (see *note Standard Encodings: fba.).  The encoding is used for
all lexical analysis, including string literals, comments and
identifiers.  All lexical analysis, including string literals, comments
and identifiers, works on Unicode text decoded using the source
encoding.  Any Unicode code point, except the NUL control character, can
appear in Python source.

     source_character:  <any Unicode code point, except NUL>


File: python.info,  Node: Explicit line joining,  Next: Implicit line joining,  Prev: Encoding declarations,  Up: Line structure

4.2.1.5 Explicit line joining
.............................

Two or more physical lines may be joined into logical lines using
backslash characters (‘\’), as follows: when a physical line ends in a
backslash that is not part of a string literal or comment, it is joined
with the following forming a single logical line, deleting the backslash
and the following end-of-line character.  For example:

     if 1900 < year < 2100 and 1 <= month <= 12 \
        and 1 <= day <= 31 and 0 <= hour < 24 \
        and 0 <= minute < 60 and 0 <= second < 60:   # Looks like a valid date
             return 1

A line ending in a backslash cannot carry a comment.  A backslash does
not continue a comment.  A backslash does not continue a token except
for string literals (i.e., tokens other than string literals cannot be
split across physical lines using a backslash).  A backslash is illegal
elsewhere on a line outside a string literal.


File: python.info,  Node: Implicit line joining,  Next: Blank lines,  Prev: Explicit line joining,  Up: Line structure

4.2.1.6 Implicit line joining
.............................

Expressions in parentheses, square brackets or curly braces can be split
over more than one physical line without using backslashes.  For
example:

     month_names = ['Januari', 'Februari', 'Maart',      # These are the
                    'April',   'Mei',      'Juni',       # Dutch names
                    'Juli',    'Augustus', 'September',  # for the months
                    'Oktober', 'November', 'December']   # of the year

Implicitly continued lines can carry comments.  The indentation of the
continuation lines is not important.  Blank continuation lines are
allowed.  There is no NEWLINE token between implicit continuation lines.
Implicitly continued lines can also occur within triple-quoted strings
(see below); in that case they cannot carry comments.


File: python.info,  Node: Blank lines,  Next: Indentation,  Prev: Implicit line joining,  Up: Line structure

4.2.1.7 Blank lines
...................

A logical line that contains only spaces, tabs, formfeeds and possibly a
comment, is ignored (i.e., no *note NEWLINE: 227d. token is generated).
During interactive input of statements, handling of a blank line may
differ depending on the implementation of the read-eval-print loop.  In
the standard interactive interpreter, an entirely blank logical line
(that is, one containing not even whitespace or a comment) terminates a
multi-line statement.


File: python.info,  Node: Indentation,  Next: Whitespace between tokens,  Prev: Blank lines,  Up: Line structure

4.2.1.8 Indentation
...................

Leading whitespace (spaces and tabs) at the beginning of a logical line
is used to compute the indentation level of the line, which in turn is
used to determine the grouping of statements.

Tabs are replaced (from left to right) by one to eight spaces such that
the total number of characters up to and including the replacement is a
multiple of eight (this is intended to be the same rule as used by
Unix).  The total number of spaces preceding the first non-blank
character then determines the line’s indentation.  Indentation cannot be
split over multiple physical lines using backslashes; the whitespace up
to the first backslash determines the indentation.

Indentation is rejected as inconsistent if a source file mixes tabs and
spaces in a way that makes the meaning dependent on the worth of a tab
in spaces; a *note TabError: 766. is raised in that case.

'Cross-platform compatibility note:' because of the nature of text
editors on non-UNIX platforms, it is unwise to use a mixture of spaces
and tabs for the indentation in a single source file.  It should also be
noted that different platforms may explicitly limit the maximum
indentation level.

A formfeed character may be present at the start of the line; it will be
ignored for the indentation calculations above.  Formfeed characters
occurring elsewhere in the leading whitespace have an undefined effect
(for instance, they may reset the space count to zero).

The indentation levels of consecutive lines are used to generate *note
INDENT: 20e6. and *note DEDENT: 229b. tokens, using a stack, as follows.

Before the first line of the file is read, a single zero is pushed on
the stack; this will never be popped off again.  The numbers pushed on
the stack will always be strictly increasing from bottom to top.  At the
beginning of each logical line, the line’s indentation level is compared
to the top of the stack.  If it is equal, nothing happens.  If it is
larger, it is pushed on the stack, and one ‘INDENT’ token is generated.
If it is smaller, it 'must' be one of the numbers occurring on the
stack; all numbers on the stack that are larger are popped off, and for
each number popped off a ‘DEDENT’ token is generated.  At the end of the
file, a ‘DEDENT’ token is generated for each number remaining on the
stack that is larger than zero.

Here is an example of a correctly (though confusingly) indented piece of
Python code:

     def perm(l):
             # Compute the list of all permutations of l
         if len(l) <= 1:
                       return [l]
         r = []
         for i in range(len(l)):
                  s = l[:i] + l[i+1:]
                  p = perm(s)
                  for x in p:
                   r.append(l[i:i+1] + x)
         return r

The following example shows various indentation errors:

      def perm(l):                       # error: first line indented
     for i in range(len(l)):             # error: not indented
         s = l[:i] + l[i+1:]
             p = perm(l[:i] + l[i+1:])   # error: unexpected indent
             for x in p:
                     r.append(l[i:i+1] + x)
                 return r                # error: inconsistent dedent

(Actually, the first three errors are detected by the parser; only the
last error is found by the lexical analyzer — the indentation of ‘return
r’ does not match a level popped off the stack.)


File: python.info,  Node: Whitespace between tokens,  Next: End marker,  Prev: Indentation,  Up: Line structure

4.2.1.9 Whitespace between tokens
.................................

Except at the beginning of a logical line or in string literals, the
whitespace characters space, tab and formfeed can be used
interchangeably to separate tokens:

     whitespace:  ' ' | tab | formfeed

Whitespace is needed between two tokens only if their concatenation
could otherwise be interpreted as a different token.  For example, ‘ab’
is one token, but ‘a b’ is two tokens.  However, ‘+a’ and ‘+ a’ both
produce two tokens, ‘+’ and ‘a’, as ‘+a’ is not a valid token.


File: python.info,  Node: End marker,  Prev: Whitespace between tokens,  Up: Line structure

4.2.1.10 End marker
...................

At the end of non-interactive input, the lexical analyzer generates an
*note ENDMARKER: 229f. token.


File: python.info,  Node: Other tokens,  Next: Names identifiers and keywords,  Prev: Line structure,  Up: Lexical analysis

4.2.2 Other tokens
------------------

Besides *note NEWLINE: 227d, *note INDENT: 20e6. and *note DEDENT: 229b,
the following categories of tokens exist: 'identifiers' and 'keywords'
(*note NAME: 22a2.), 'literals' (such as *note NUMBER: 22a3. and *note
STRING: 22a4.), and other symbols ('operators' and 'delimiters', *note
OP: 2273.).  Whitespace characters (other than logical line terminators,
discussed earlier) are not tokens, but serve to delimit tokens.  Where
ambiguity exists, a token comprises the longest possible string that
forms a legal token, when read from left to right.


File: python.info,  Node: Names identifiers and keywords,  Next: Literals,  Prev: Other tokens,  Up: Lexical analysis

4.2.3 Names (identifiers and keywords)
--------------------------------------

*note NAME: 22a2. tokens represent 'identifiers', 'keywords', and 'soft
keywords'.

Names are composed of the following characters:

   * uppercase and lowercase letters (‘A-Z’ and ‘a-z’),

   * the underscore (‘_’),

   * digits (‘0’ through ‘9’), which cannot appear as the first
     character, and

   * non-ASCII characters.  Valid names may only contain «letter-like»
     and «digit-like» characters; see *note Non-ASCII characters in
     names: 22a6. for details.

Names must contain at least one character, but have no upper length
limit.  Case is significant.

Formally, names are described by the following lexical definitions:

     NAME:          *note name_start: 22a8. *note name_continue: 22a9.*
     name_start:    "a"..."z" | "A"..."Z" | "_" | <non-ASCII character>
     name_continue: name_start | "0"..."9"
     identifier:    <*note NAME: 22a7, except keywords>

Note that not all names matched by this grammar are valid; see *note
Non-ASCII characters in names: 22a6. for details.

* Menu:

* Keywords::
* Soft Keywords::
* Reserved classes of identifiers::
* Non-ASCII characters in names::


File: python.info,  Node: Keywords,  Next: Soft Keywords,  Up: Names identifiers and keywords

4.2.3.1 Keywords
................

The following names are used as reserved words, or 'keywords' of the
language, and cannot be used as ordinary identifiers.  They must be
spelled exactly as written here:

     False      await      else       import     pass
     None       break      except     in         raise
     True       class      finally    is         return
     and        continue   for        lambda     try
     as         def        from       nonlocal   while
     assert     del        global     not        with
     async      elif       if         or         yield


File: python.info,  Node: Soft Keywords,  Next: Reserved classes of identifiers,  Prev: Keywords,  Up: Names identifiers and keywords

4.2.3.2 Soft Keywords
.....................

Added in version 3.10.

Some names are only reserved under specific contexts.  These are known
as 'soft keywords':

   - ‘match’, ‘case’, and ‘_’, when used in the *note match: a10.
     statement.

   - ‘type’, when used in the *note type: 66d. statement.

These syntactically act as keywords in their specific contexts, but this
distinction is done at the parser level, not when tokenizing.

As soft keywords, their use in the grammar is possible while still
preserving compatibility with existing code that uses these names as
identifier names.

Cambiato nella versione 3.12: ‘type’ is now a soft keyword.


File: python.info,  Node: Reserved classes of identifiers,  Next: Non-ASCII characters in names,  Prev: Soft Keywords,  Up: Names identifiers and keywords

4.2.3.3 Reserved classes of identifiers
.......................................

Certain classes of identifiers (besides keywords) have special meanings.
These classes are identified by the patterns of leading and trailing
underscore characters:

‘_*’

     Not imported by ‘from module import *’.

‘_’

     In a ‘case’ pattern within a *note match: a10. statement, ‘_’ is a
     *note soft keyword: a0f. that denotes a *note wildcard: a11.

     Separately, the interactive interpreter makes the result of the
     last evaluation available in the variable ‘_’.  (It is stored in
     the *note builtins: 13. module, alongside built-in functions like
     ‘print’.)

     Elsewhere, ‘_’ is a regular identifier.  It is often used to name
     «special» items, but it is not special to Python itself.

          Nota: The name ‘_’ is often used in conjunction with
          internationalization; refer to the documentation for the *note
          gettext: 67. module for more information on this convention.

          It is also commonly used for unused variables.

‘__*__’

     System-defined names, informally known as «dunder» names.  These
     names are defined by the interpreter and its implementation
     (including the standard library).  Current system names are
     discussed in the *note Special method names: e6a. section and
     elsewhere.  More will likely be defined in future versions of
     Python.  'Any' use of ‘__*__’ names, in any context, that does not
     follow explicitly documented use, is subject to breakage without
     warning.

‘__*’

     Class-private names.  Names in this category, when used within the
     context of a class definition, are re-written to use a mangled form
     to help avoid name clashes between «private» attributes of base and
     derived classes.  See section *note Identifiers (Names): 22af.


File: python.info,  Node: Non-ASCII characters in names,  Prev: Reserved classes of identifiers,  Up: Names identifiers and keywords

4.2.3.4 Non-ASCII characters in names
.....................................

Names that contain non-ASCII characters need additional normalization
and validation beyond the rules and grammar explained *note above: 2289.
For example, ‘ř_1’, ‘蛇’, or ‘साँप’ are valid names, but ‘r〰2’, ‘€’, or
‘🐍’ are not.

This section explains the exact rules.

All names are converted into the normalization form(1) NFKC while
parsing.  This means that, for example, some typographic variants of
characters are converted to their «basic» form.  For example,
‘ﬁⁿₐˡᵢᶻₐᵗᵢᵒₙ’ normalizes to ‘finalization’, so Python treats them as the
same name:

     >>> ﬁⁿₐˡᵢᶻₐᵗᵢᵒₙ = 3
     >>> finalization
     3

     Nota: Normalization is done at the lexical level only.  Run-time
     functions that take names as 'strings' generally do not normalize
     their arguments.  For example, the variable defined above is
     accessible at run time in the *note globals(): 1bf2. dictionary as
     ‘globals()["finalization"]’ but not ‘globals()["ﬁⁿₐˡᵢᶻₐᵗᵢᵒₙ"]’.

Similarly to how ASCII-only names must contain only letters, digits and
the underscore, and cannot start with a digit, a valid name must start
with a character in the «letter-like» set ‘xid_start’, and the remaining
characters must be in the «letter- and digit-like» set ‘xid_continue’.

These sets based on the 'XID_Start' and 'XID_Continue' sets as defined
by the Unicode standard annex UAX-31(2).  Python’s ‘xid_start’
additionally includes the underscore (‘_’).  Note that Python does not
necessarily conform to UAX-31(3).

A non-normative listing of characters in the 'XID_Start' and
'XID_Continue' sets as defined by Unicode is available in the
DerivedCoreProperties.txt(4) file in the Unicode Character Database.
For reference, the construction rules for the ‘xid_*’ sets are given
below.

The set ‘id_start’ is defined as the union of:

   * Unicode category ‘<Lu>’ - uppercase letters (includes ‘A’ to ‘Z’)

   * Unicode category ‘<Ll>’ - lowercase letters (includes ‘a’ to ‘z’)

   * Unicode category ‘<Lt>’ - titlecase letters

   * Unicode category ‘<Lm>’ - modifier letters

   * Unicode category ‘<Lo>’ - other letters

   * Unicode category ‘<Nl>’ - letter numbers

   * {‘"_"’} - the underscore

   * ‘<Other_ID_Start>’ - an explicit set of characters in
     PropList.txt(5) to support backwards compatibility

The set ‘xid_start’ then closes this set under NFKC normalization, by
removing all characters whose normalization is not of the form ‘id_start
id_continue*’.

The set ‘id_continue’ is defined as the union of:

   * ‘id_start’ (see above)

   * Unicode category ‘<Nd>’ - decimal numbers (includes ‘0’ to ‘9’)

   * Unicode category ‘<Pc>’ - connector punctuations

   * Unicode category ‘<Mn>’ - nonspacing marks

   * Unicode category ‘<Mc>’ - spacing combining marks

   * ‘<Other_ID_Continue>’ - another explicit set of characters in
     PropList.txt(6) to support backwards compatibility

Again, ‘xid_continue’ closes this set under NFKC normalization.

Unicode categories use the version of the Unicode Character Database as
included in the *note unicodedata: 10b. module.

Vedi anche
..........

   * PEP 3131(7) – Supporting Non-ASCII Identifiers

   * PEP 672(8) – Unicode-related Security Considerations for Python

   ---------- Footnotes ----------

   (1) https://www.unicode.org/reports/tr15/#Norm_Forms

   (2) https://www.unicode.org/reports/tr31/

   (3) https://www.unicode.org/reports/tr31/

   (4) 
https://www.unicode.org/Public/16.0.0/ucd/DerivedCoreProperties.txt

   (5) https://www.unicode.org/Public/16.0.0/ucd/PropList.txt

   (6) https://www.unicode.org/Public/16.0.0/ucd/PropList.txt

   (7) https://peps.python.org/pep-3131/

   (8) https://peps.python.org/pep-0672/


File: python.info,  Node: Literals,  Next: String and Bytes literals,  Prev: Names identifiers and keywords,  Up: Lexical analysis

4.2.4 Literals
--------------

Literals are notations for constant values of some built-in types.

In terms of lexical analysis, Python has *note string, bytes: 2288. and
*note numeric: 228a. literals.

Other «literals» are lexically denoted using *note keywords: 2272.
(‘None’, ‘True’, ‘False’) and the special *note ellipsis token: 22b3.
(‘...’).


File: python.info,  Node: String and Bytes literals,  Next: Numeric literals,  Prev: Literals,  Up: Lexical analysis

4.2.5 String and Bytes literals
-------------------------------

String literals are text enclosed in single quotes (‘'’) or double
quotes (‘"’).  For example:

     "spam"
     'eggs'

The quote used to start the literal also terminates it, so a string
literal can only contain the other quote (except with escape sequences,
see below).  For example:

     'Say "Hello", please.'
     "Don't do that!"

Except for this limitation, the choice of quote character (‘'’ or ‘"’)
does not affect how the literal is parsed.

Inside a string literal, the backslash (‘\’) character introduces an
'escape sequence', which has special meaning depending on the character
after the backslash.  For example, ‘\"’ denotes the double quote
character, and does 'not' end the string:

     >>> print("Say \"Hello\" to everyone!")
     Say "Hello" to everyone!

See *note escape sequences: 688. below for a full list of such
sequences, and more details.

* Menu:

* Triple-quoted strings::
* String prefixes::
* Formal grammar::
* Escape sequences::
* Bytes literals::
* Raw string literals::
* f-strings::
* t-strings::
* Formal grammar for f-strings::


File: python.info,  Node: Triple-quoted strings,  Next: String prefixes,  Up: String and Bytes literals

4.2.5.1 Triple-quoted strings
.............................

Strings can also be enclosed in matching groups of three single or
double quotes.  These are generally referred to as 'triple-quoted
strings':

     """This is a triple-quoted string."""

In triple-quoted literals, unescaped quotes are allowed (and are
retained), except that three unescaped quotes in a row terminate the
literal, if they are of the same kind (‘'’ or ‘"’) used at the start:

     """This string has "quotes" inside."""

Unescaped newlines are also allowed and retained:

     '''This triple-quoted string
     continues on the next line.'''


File: python.info,  Node: String prefixes,  Next: Formal grammar,  Prev: Triple-quoted strings,  Up: String and Bytes literals

4.2.5.2 String prefixes
.......................

String literals can have an optional 'prefix' that influences how the
content of the literal is parsed, for example:

     b"data"
     f'{result=}'

The allowed prefixes are:

   * ‘b’: *note Bytes literal: 22b7.

   * ‘r’: *note Raw string: 22b8.

   * ‘f’: *note Formatted string literal: 19a. («f-string»)

   * ‘t’: *note Template string literal: 17e2. («t-string»)

   * ‘u’: No effect (allowed for backwards compatibility)

See the linked sections for details on each type.

Prefixes are case-insensitive (for example, “‘B’” works the same as
“‘b’”).  The “‘r’” prefix can be combined with “‘f’”, “‘t’” or “‘b’”, so
“‘fr’”, “‘rf’”, “‘tr’”, “‘rt’”, “‘br’”, and “‘rb’” are also valid
prefixes.

Added in version 3.3: The ‘'rb'’ prefix of raw bytes literals has been
added as a synonym of ‘'br'’.

Support for the unicode legacy literal (‘u'value'’) was reintroduced to
simplify the maintenance of dual Python 2.x and 3.x codebases.  See PEP
414(1) for more information.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0414/


File: python.info,  Node: Formal grammar,  Next: Escape sequences,  Prev: String prefixes,  Up: String and Bytes literals

4.2.5.3 Formal grammar
......................

String literals, except *note «f-strings»: 19a. and *note «t-strings»:
17e2, are described by the following lexical definitions.

These definitions use *note negative lookaheads: 2277. (‘!’) to indicate
that an ending quote ends the literal.

     STRING:          [*note stringprefix: 22bb.] (*note stringcontent: 22bc.)
     stringprefix:    <("r" | "u" | "b" | "br" | "rb"), case-insensitive>
     stringcontent:
        | "'''" ( !"'''" *note longstringitem: 22bd.)* "'''"
        | '"""' ( !'"""' *note longstringitem: 22bd.)* '"""'
        | "'" ( !"'" *note stringitem: 22be.)* "'"
        | '"' ( !'"' *note stringitem: 22be.)* '"'
     stringitem:      *note stringchar: 22bf. | *note stringescapeseq: 22c0.
     stringchar:      <any *note source_character: 2295, except backslash and newline>
     longstringitem:  *note stringitem: 22be. | newline
     stringescapeseq: "\" <any *note source_character: 2295.>

Note that as in all lexical definitions, whitespace is significant.  In
particular, the prefix (if any) must be immediately followed by the
starting quote.


File: python.info,  Node: Escape sequences,  Next: Bytes literals,  Prev: Formal grammar,  Up: String and Bytes literals

4.2.5.4 Escape sequences
........................

Unless an “‘r’” or “‘R’” prefix is present, escape sequences in string
and bytes literals are interpreted according to rules similar to those
used by Standard C. The recognized escape sequences are:

Escape Sequence                                        Meaning
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
‘\’<newline>                                           *note Ignored end of line: 22c2.
                                                       
                                                       
‘\\’                                                   *note Backslash: 22c3.
                                                       
                                                       
‘\'’                                                   *note Single quote: 22c3.
                                                       
                                                       
‘\"’                                                   *note Double quote: 22c3.
                                                       
                                                       
‘\a’                                                   ASCII Bell (BEL)
                                                       
                                                       
‘\b’                                                   ASCII Backspace (BS)
                                                       
                                                       
‘\f’                                                   ASCII Formfeed (FF)
                                                       
                                                       
‘\n’                                                   ASCII Linefeed (LF)
                                                       
                                                       
‘\r’                                                   ASCII Carriage Return (CR)
                                                       
                                                       
‘\t’                                                   ASCII Horizontal Tab (TAB)
                                                       
                                                       
‘\v’                                                   ASCII Vertical Tab (VT)
                                                       
                                                       
‘\OOO’                                                 *note Octal character: 22c4.
                                                       
                                                       
‘\xHH’                                                 *note Hexadecimal character: 22c5.
                                                       
                                                       
‘\N{NAME}’                                             *note Named Unicode character: 22c6.
                                                       
                                                       
‘\uXXXX’                                               *note Hexadecimal Unicode character: 22c7.
                                                       
                                                       
‘\UXXXXXXXX’                                           *note Hexadecimal Unicode character: 22c7.
                                                       

* Menu:

* Ignored end of line::
* Escaped characters::
* Octal character::
* Hexadecimal character::
* Named Unicode character::
* Hexadecimal Unicode characters::
* Unrecognized escape sequences::


File: python.info,  Node: Ignored end of line,  Next: Escaped characters,  Up: Escape sequences

4.2.5.5 Ignored end of line
...........................

A backslash can be added at the end of a line to ignore the newline:

     >>> 'This string will not include \
     ... backslashes or newline characters.'
     'This string will not include backslashes or newline characters.'

The same result can be achieved using *note triple-quoted strings: 2288,
or parentheses and *note string literal concatenation: 22c9.


File: python.info,  Node: Escaped characters,  Next: Octal character,  Prev: Ignored end of line,  Up: Escape sequences

4.2.5.6 Escaped characters
..........................

To include a backslash in a non-*note raw: 22b8. Python string literal,
it must be doubled.  The ‘\\’ escape sequence denotes a single backslash
character:

     >>> print('C:\\Program Files')
     C:\Program Files

Similarly, the ‘\'’ and ‘\"’ sequences denote the single and double
quote character, respectively:

     >>> print('\' and \"')
     ' and "


File: python.info,  Node: Octal character,  Next: Hexadecimal character,  Prev: Escaped characters,  Up: Escape sequences

4.2.5.7 Octal character
.......................

The sequence ‘\OOO’ denotes a 'character' with the octal (base 8) value
'ooo':

     >>> '\120'
     'P'

Up to three octal digits (0 through 7) are accepted.

In a bytes literal, 'character' means a 'byte' with the given value.  In
a string literal, it means a Unicode character with the given value.

Cambiato nella versione 3.11: Octal escapes with value larger than
‘0o377’ (255) produce a *note DeprecationWarning: 1a3.

Cambiato nella versione 3.12: Octal escapes with value larger than
‘0o377’ (255) produce a *note SyntaxWarning: 1ae.  In a future Python
version they will raise a *note SyntaxError: 18e.


File: python.info,  Node: Hexadecimal character,  Next: Named Unicode character,  Prev: Octal character,  Up: Escape sequences

4.2.5.8 Hexadecimal character
.............................

The sequence ‘\xHH’ denotes a 'character' with the hex (base 16) value
'hh':

     >>> '\x50'
     'P'

Unlike in Standard C, exactly two hex digits are required.

In a bytes literal, 'character' means a 'byte' with the given value.  In
a string literal, it means a Unicode character with the given value.


File: python.info,  Node: Named Unicode character,  Next: Hexadecimal Unicode characters,  Prev: Hexadecimal character,  Up: Escape sequences

4.2.5.9 Named Unicode character
...............................

The sequence ‘\N{NAME}’ denotes a Unicode character with the given
'name':

     >>> '\N{LATIN CAPITAL LETTER P}'
     'P'
     >>> '\N{SNAKE}'
     '🐍'

This sequence cannot appear in *note bytes literals: 22b7.

Cambiato nella versione 3.3: Support for name aliases(1) has been added.

   ---------- Footnotes ----------

   (1) https://www.unicode.org/Public/16.0.0/ucd/NameAliases.txt


File: python.info,  Node: Hexadecimal Unicode characters,  Next: Unrecognized escape sequences,  Prev: Named Unicode character,  Up: Escape sequences

4.2.5.10 Hexadecimal Unicode characters
.......................................

These sequences ‘\uXXXX’ and ‘\UXXXXXXXX’ denote the Unicode character
with the given hex (base 16) value.  Exactly four digits are required
for ‘\u’; exactly eight digits are required for ‘\U’.  The latter can
encode any Unicode character.

     >>> '\u1234'
     'ሴ'
     >>> '\U0001f40d'
     '🐍'

These sequences cannot appear in *note bytes literals: 22b7.


File: python.info,  Node: Unrecognized escape sequences,  Prev: Hexadecimal Unicode characters,  Up: Escape sequences

4.2.5.11 Unrecognized escape sequences
......................................

Unlike in Standard C, all unrecognized escape sequences are left in the
string unchanged, that is, 'the backslash is left in the result':

     >>> print('\q')
     \q
     >>> list('\q')
     ['\\', 'q']

Note that for bytes literals, the escape sequences only recognized in
string literals (‘\N...’, ‘\u...’, ‘\U...’) fall into the category of
unrecognized escapes.

Cambiato nella versione 3.6: Unrecognized escape sequences produce a
*note DeprecationWarning: 1a3.

Cambiato nella versione 3.12: Unrecognized escape sequences produce a
*note SyntaxWarning: 1ae.  In a future Python version they will raise a
*note SyntaxError: 18e.


File: python.info,  Node: Bytes literals,  Next: Raw string literals,  Prev: Escape sequences,  Up: String and Bytes literals

4.2.5.12 Bytes literals
.......................

'Bytes literals' are always prefixed with “‘b’” or “‘B’”; they produce
an instance of the *note bytes: 192. type instead of the *note str: 169.
type.  They may only contain ASCII characters; bytes with a numeric
value of 128 or greater must be expressed with escape sequences
(typically *note Hexadecimal character: 22c5. or *note Octal character:
22c4.):

     >>> b'\x89PNG\r\n\x1a\n'
     b'\x89PNG\r\n\x1a\n'
     >>> list(b'\x89PNG\r\n\x1a\n')
     [137, 80, 78, 71, 13, 10, 26, 10]

Similarly, a zero byte must be expressed using an escape sequence
(typically ‘\0’ or ‘\x00’).


File: python.info,  Node: Raw string literals,  Next: f-strings,  Prev: Bytes literals,  Up: String and Bytes literals

4.2.5.13 Raw string literals
............................

Both string and bytes literals may optionally be prefixed with a letter
“‘r’” or “‘R’”; such constructs are called 'raw string literals' and
'raw bytes literals' respectively and treat backslashes as literal
characters.  As a result, in raw string literals, *note escape
sequences: 688. are not treated specially:

     >>> r'\d{4}-\d{2}-\d{2}'
     '\\d{4}-\\d{2}-\\d{2}'

Even in a raw literal, quotes can be escaped with a backslash, but the
backslash remains in the result; for example, ‘r"\""’ is a valid string
literal consisting of two characters: a backslash and a double quote;
‘r"\"’ is not a valid string literal (even a raw string cannot end in an
odd number of backslashes).  Specifically, 'a raw literal cannot end in
a single backslash' (since the backslash would escape the following
quote character).  Note also that a single backslash followed by a
newline is interpreted as those two characters as part of the literal,
'not' as a line continuation.


File: python.info,  Node: f-strings,  Next: t-strings,  Prev: Raw string literals,  Up: String and Bytes literals

4.2.5.14 f-strings
..................

Added in version 3.6.

Cambiato nella versione 3.7: The *note await: 18d. and *note async for:
ca3. can be used in expressions within f-strings.

Cambiato nella versione 3.8: Added the debug specifier (‘=’)

Cambiato nella versione 3.12: Many restrictions on expressions within
f-strings have been removed.  Notably, nested strings, comments, and
backslashes are now permitted.

A 'formatted string literal' or 'f-string' is a string literal that is
prefixed with “‘f’” or “‘F’”.  Unlike other string literals, f-strings
do not have a constant value.  They may contain 'replacement fields'
delimited by curly braces ‘{}’.  Replacement fields contain expressions
which are evaluated at run time.  For example:

     >>> who = 'nobody'
     >>> nationality = 'Spanish'
     >>> f'{who.title()} expects the {nationality} Inquisition!'
     'Nobody expects the Spanish Inquisition!'

Any doubled curly braces (‘{{’ or ‘}}’) outside replacement fields are
replaced with the corresponding single curly brace:

     >>> print(f'{{...}}')
     {...}

Other characters outside replacement fields are treated like in ordinary
string literals.  This means that escape sequences are decoded (except
when a literal is also marked as a raw string), and newlines are
possible in triple-quoted f-strings:

     >>> name = 'Galahad'
     >>> favorite_color = 'blue'
     >>> print(f'{name}:\t{favorite_color}')
     Galahad:       blue
     >>> print(rf"C:\Users\{name}")
     C:\Users\Galahad
     >>> print(f'''Three shall be the number of the counting
     ... and the number of the counting shall be three.''')
     Three shall be the number of the counting
     and the number of the counting shall be three.

Expressions in formatted string literals are treated like regular Python
expressions.  Each expression is evaluated in the context where the
formatted string literal appears, in order from left to right.  An empty
expression is not allowed, and both *note lambda: 14a5. and assignment
expressions ‘:=’ must be surrounded by explicit parentheses:

     >>> f'{(half := 1/2)}, {half * 42}'
     '0.5, 21.0'

Reusing the outer f-string quoting type inside a replacement field is
permitted:

     >>> a = dict(x=2)
     >>> f"abc {a["x"]} def"
     'abc 2 def'

Backslashes are also allowed in replacement fields and are evaluated the
same way as in any other context:

     >>> a = ["a", "b", "c"]
     >>> print(f"List a contains:\n{"\n".join(a)}")
     List a contains:
     a
     b
     c

It is possible to nest f-strings:

     >>> name = 'world'
     >>> f'Repeated:{f' hello {name}' * 3}'
     'Repeated: hello world hello world hello world'

Portable Python programs should not use more than 5 levels of nesting.

'Dettaglio dell’implementazione di CPython:' CPython does not limit
nesting of f-strings.

Replacement expressions can contain newlines in both single-quoted and
triple-quoted f-strings and they can contain comments.  Everything that
comes after a ‘#’ inside a replacement field is a comment (even closing
braces and quotes).  This means that replacement fields with comments
must be closed in a different line:

     >>> a = 2
     >>> f"abc{a  # This comment  }"  continues until the end of the line
     ...       + 3}"
     'abc5'

After the expression, replacement fields may optionally contain:

   * a 'debug specifier' – an equal sign (‘=’), optionally surrounded by
     whitespace on one or both sides;

   * a 'conversion specifier' – ‘!s’, ‘!r’ or ‘!a’; and/or

   * a 'format specifier' prefixed with a colon (‘:’).

See the *note Standard Library section on f-strings: 22d4. for details
on how these fields are evaluated.

As that section explains, 'format specifiers' are passed as the second
argument to the *note format(): 199. function to format a replacement
field value.  For example, they can be used to specify a field width and
padding characters using the *note Format Specification Mini-Language:
4fa.:

     >>> number = 14.3
     >>> f'{number:20.7f}'
     '          14.3000000'

Top-level format specifiers may include nested replacement fields:

     >>> field_size = 20
     >>> precision = 7
     >>> f'{number:{field_size}.{precision}f}'
     '          14.3000000'

These nested fields may include their own conversion fields and *note
format specifiers: 4fa.:

     >>> number = 3
     >>> f'{number:{field_size}}'
     '                   3'
     >>> f'{number:{field_size:05}}'
     '00000000000000000003'

However, these nested fields may not include more deeply nested
replacement fields.

Formatted string literals cannot be used as *note docstrings: 22d5, even
if they do not include expressions:

     >>> def foo():
     ...     f"Not a docstring"
     ...
     >>> print(foo.__doc__)
     None

Vedi anche
..........

   * PEP 498(1) – Literal String Interpolation

   * PEP 701(2) – Syntactic formalization of f-strings

   * *note str.format(): 834, which uses a related format string
     mechanism.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0498/

   (2) https://peps.python.org/pep-0701/


File: python.info,  Node: t-strings,  Next: Formal grammar for f-strings,  Prev: f-strings,  Up: String and Bytes literals

4.2.5.15 t-strings
..................

Added in version 3.14.

A 'template string literal' or 't-string' is a string literal that is
prefixed with “‘t’” or “‘T’”.  These strings follow the same syntax
rules as *note formatted string literals: 19a.  For differences in
evaluation rules, see the *note Standard Library section on t-strings:
22d8.


File: python.info,  Node: Formal grammar for f-strings,  Prev: t-strings,  Up: String and Bytes literals

4.2.5.16 Formal grammar for f-strings
.....................................

F-strings are handled partly by the *note lexical analyzer: 227b, which
produces the tokens *note FSTRING_START: 22da, *note FSTRING_MIDDLE:
22db. and *note FSTRING_END: 22dc, and partly by the parser, which
handles expressions in the replacement field.  The exact way the work is
split is a CPython implementation detail.

Correspondingly, the f-string grammar is a mix of *note lexical and
syntactic definitions: 2276.

Whitespace is significant in these situations:

   * There may be no whitespace in *note FSTRING_START: 22da. (between
     the prefix and quote).

   * Whitespace in *note FSTRING_MIDDLE: 22db. is part of the literal
     string contents.

   * In ‘fstring_replacement_field’, if ‘f_debug_specifier’ is present,
     all whitespace after the opening brace until the
     ‘f_debug_specifier’, as well as whitespace immediately following
     ‘f_debug_specifier’, is retained as part of the expression.

     'Dettaglio dell’implementazione di CPython:' The expression is not
     handled in the tokenization phase; it is retrieved from the source
     code using locations of the ‘{’ token and the token after ‘=’.

The ‘FSTRING_MIDDLE’ definition uses *note negative lookaheads: 2277.
(‘!’) to indicate special characters (backslash, newline, ‘{’, ‘}’) and
sequences (‘f_quote’).

     fstring:    *note FSTRING_START: 22de. *note fstring_middle: 22df.* *note FSTRING_END: 22e0.

     FSTRING_START:      *note fstringprefix: 22e1. ("'" | '"' | "'''" | '"""')
     FSTRING_END:        *note f_quote: 22e2.
     fstringprefix:      <("f" | "fr" | "rf"), case-insensitive>
     f_debug_specifier:  '='
     f_quote:            <the quote character(s) used in FSTRING_START>

     fstring_middle:
        | *note fstring_replacement_field: 22e4.
        | *note FSTRING_MIDDLE: 22e5.
     FSTRING_MIDDLE:
        | (!"\" !*note newline: 2292. !'{' !'}' !*note f_quote: 22e2.) *note source_character: 2295.
        | *note stringescapeseq: 22c0.
        | "{{"
        | "}}"
        | <newline, in triple-quoted f-strings only>
     fstring_replacement_field:
        | '{' *note f_expression: 22e6. [*note f_debug_specifier: 22e3.] [*note fstring_conversion: 22e7.]
              [*note fstring_full_format_spec: 22e8.] '}'
     fstring_conversion:
        | "!" ("s" | "r" | "a")
     fstring_full_format_spec:
        | ':' *note fstring_format_spec: 22e9.*
     fstring_format_spec:
        | *note FSTRING_MIDDLE: 22e5.
        | *note fstring_replacement_field: 22e4.
     f_expression:
        | ','.(*note conditional_expression: 22ea. | "*" *note or_expr: 22eb.)+ [","]
        | *note yield_expression: 22ec.

     Nota: In the above grammar snippet, the ‘f_quote’ and
     ‘FSTRING_MIDDLE’ rules are context-sensitive – they depend on the
     contents of ‘FSTRING_START’ of the nearest enclosing ‘fstring’.

     Constructing a more traditional formal grammar from this template
     is left as an exercise for the reader.

The grammar for t-strings is identical to the one for f-strings, with
't' instead of 'f' at the beginning of rule and token names and in the
prefix.

     tstring:    TSTRING_START tstring_middle* TSTRING_END

     <rest of the t-string grammar is omitted; see above>


File: python.info,  Node: Numeric literals,  Next: Operators and delimiters,  Prev: String and Bytes literals,  Up: Lexical analysis

4.2.6 Numeric literals
----------------------

*note NUMBER: 22a3. tokens represent numeric literals, of which there
are three types: integers, floating-point numbers, and imaginary
numbers.

     NUMBER: *note integer: 22f0. | *note floatnumber: 22f1. | *note imagnumber: 22f2.

The numeric value of a numeric literal is the same as if it were passed
as a string to the *note int: 19b, *note float: 196. or *note complex:
197. class constructor, respectively.  Note that not all valid inputs
for those constructors are also valid literals.

Numeric literals do not include a sign; a phrase like ‘-1’ is actually
an expression composed of the unary operator “‘-’” and the literal ‘1’.

* Menu:

* Integer literals::
* Floating-point literals::
* Imaginary literals::


File: python.info,  Node: Integer literals,  Next: Floating-point literals,  Up: Numeric literals

4.2.6.1 Integer literals
........................

Integer literals denote whole numbers.  For example:

     7
     3
     2147483647

There is no limit for the length of integer literals apart from what can
be stored in available memory:

     7922816251426433759354395033679228162514264337593543950336

Underscores can be used to group digits for enhanced readability, and
are ignored for determining the numeric value of the literal.  For
example, the following literals are equivalent:

     100_000_000_000
     100000000000
     1_00_00_00_00_000

Underscores can only occur between digits.  For example, ‘_123’, ‘321_’,
and ‘123__321’ are 'not' valid literals.

Integers can be specified in binary (base 2), octal (base 8), or
hexadecimal (base 16) using the prefixes ‘0b’, ‘0o’ and ‘0x’,
respectively.  Hexadecimal digits 10 through 15 are represented by
letters ‘A’-‘F’, case-insensitive.  For example:

     0b100110111
     0b_1110_0101
     0o177
     0o377
     0xdeadbeef
     0xDead_Beef

An underscore can follow the base specifier.  For example, ‘0x_1f’ is a
valid literal, but ‘0_x1f’ and ‘0x__1f’ are not.

Leading zeros in a non-zero decimal number are not allowed.  For
example, ‘0123’ is not a valid literal.  This is for disambiguation with
C-style octal literals, which Python used before version 3.0.

Formally, integer literals are described by the following lexical
definitions:

     integer:      *note decinteger: 22f5. | *note bininteger: 22f6. | *note octinteger: 22f7. | *note hexinteger: 22f8. | *note zerointeger: 22f9.
     decinteger:   *note nonzerodigit: 22fa. (["_"] *note digit: 22fb.)*
     bininteger:   "0" ("b" | "B") (["_"] *note bindigit: 22fc.)+
     octinteger:   "0" ("o" | "O") (["_"] *note octdigit: 22fd.)+
     hexinteger:   "0" ("x" | "X") (["_"] *note hexdigit: 22fe.)+
     zerointeger:  "0"+ (["_"] "0")*
     nonzerodigit: "1"..."9"
     digit:        "0"..."9"
     bindigit:     "0" | "1"
     octdigit:     "0"..."7"
     hexdigit:     *note digit: 22fb. | "a"..."f" | "A"..."F"

Cambiato nella versione 3.6: Underscores are now allowed for grouping
purposes in literals.


File: python.info,  Node: Floating-point literals,  Next: Imaginary literals,  Prev: Integer literals,  Up: Numeric literals

4.2.6.2 Floating-point literals
...............................

Floating-point (float) literals, such as ‘3.14’ or ‘1.5’, denote *note
approximations of real numbers: 2301.

They consist of 'integer' and 'fraction' parts, each composed of decimal
digits.  The parts are separated by a decimal point, ‘.’:

     2.71828
     4.0

Unlike in integer literals, leading zeros are allowed.  For example,
‘077.010’ is legal, and denotes the same number as ‘77.01’.

As in integer literals, single underscores may occur between digits to
help readability:

     96_485.332_123
     3.14_15_93

Either of these parts, but not both, can be empty.  For example:

     10.  # (equivalent to 10.0)
     .001  # (equivalent to 0.001)

Optionally, the integer and fraction may be followed by an 'exponent':
the letter ‘e’ or ‘E’, followed by an optional sign, ‘+’ or ‘-’, and a
number in the same format as the integer and fraction parts.  The ‘e’ or
‘E’ represents «times ten raised to the power of»:

     1.0e3  # (represents 1.0×10³, or 1000.0)
     1.166e-5  # (represents 1.166×10⁻⁵, or 0.00001166)
     6.02214076e+23  # (represents 6.02214076×10²³, or 602214076000000000000000.)

In floats with only integer and exponent parts, the decimal point may be
omitted:

     1e3  # (equivalent to 1.e3 and 1.0e3)
     0e0  # (equivalent to 0.)

Formally, floating-point literals are described by the following lexical
definitions:

     floatnumber:
        | *note digitpart: 2302. "." [*note digitpart: 2302.] [*note exponent: 2303.]
        | "." *note digitpart: 2302. [*note exponent: 2303.]
        | *note digitpart: 2302. *note exponent: 2303.
     digitpart: *note digit: 22fb. (["_"] *note digit: 22fb.)*
     exponent:  ("e" | "E") ["+" | "-"] *note digitpart: 2302.

Cambiato nella versione 3.6: Underscores are now allowed for grouping
purposes in literals.


File: python.info,  Node: Imaginary literals,  Prev: Floating-point literals,  Up: Numeric literals

4.2.6.3 Imaginary literals
..........................

Python has *note complex number: 1fc4. objects, but no complex literals.
Instead, 'imaginary literals' denote complex numbers with a zero real
part.

For example, in math, the complex number 3+4.2'i' is written as the real
number 3 added to the imaginary number 4.2'i'.  Python uses a similar
syntax, except the imaginary unit is written as ‘j’ rather than 'i':

     3+4.2j

This is an expression composed of the *note integer literal: 22f4. ‘3’,
the *note operator: 2275. “‘+’”, and the *note imaginary literal: 2304.
‘4.2j’.  Since these are three separate tokens, whitespace is allowed
between them:

     3 + 4.2j

No whitespace is allowed 'within' each token.  In particular, the ‘j’
suffix, may not be separated from the number before it.

The number before the ‘j’ has the same syntax as a floating-point
literal.  Thus, the following are valid imaginary literals:

     4.2j
     3.14j
     10.j
     .001j
     1e100j
     3.14e-10j
     3.14_15_93j

Unlike in a floating-point literal the decimal point can be omitted if
the imaginary number only has an integer part.  The number is still
evaluated as a floating-point number, not an integer:

     10j
     0j
     1000000000000000000000000j   # equivalent to 1e+24j

The ‘j’ suffix is case-insensitive.  That means you can use ‘J’ instead:

     3.14J   # equivalent to 3.14j

Formally, imaginary literals are described by the following lexical
definition:

     imagnumber: (*note floatnumber: 22f1. | *note digitpart: 2302.) ("j" | "J")


File: python.info,  Node: Operators and delimiters,  Prev: Numeric literals,  Up: Lexical analysis

4.2.7 Operators and delimiters
------------------------------

The following grammar defines 'operator' and 'delimiter' tokens, that
is, the generic *note OP: 2273. token type.  A *note list of these
tokens and their names: 2307. is also available in the ‘token’ module
documentation.

     OP:
        | assignment_operator
        | bitwise_operator
        | comparison_operator
        | enclosing_delimiter
        | other_delimiter
        | arithmetic_operator
        | "..."
        | other_op

     assignment_operator:   "+=" | "-=" | "*=" | "**=" | "/="  | "//=" | "%=" |
                            "&=" | "|=" | "^=" | "<<=" | ">>=" | "@="  | ":="
     bitwise_operator:      "&"  | "|"  | "^"  | "~"   | "<<"  | ">>"
     comparison_operator:   "<=" | ">=" | "<"  | ">"   | "=="  | "!="
     enclosing_delimiter:   "("  | ")"  | "["  | "]"   | "{"   | "}"
     other_delimiter:       ","  | ":"  | "!"  | ";"   | "="   | "->"
     arithmetic_operator:   "+"  | "-"  | "**" | "*"   | "//"  | "/"   | "%"
     other_op:              "."  | "@"

     Nota: Generally, 'operators' are used to combine *note expressions:
     2310, while 'delimiters' serve other purposes.  However, there is
     no clear, formal distinction between the two categories.

     Some tokens can serve as either operators or delimiters, depending
     on usage.  For example, ‘*’ is both the multiplication operator and
     a delimiter used for sequence unpacking, and ‘@’ is both the matrix
     multiplication and a delimiter that introduces decorators.

     For some tokens, the distinction is unclear.  For example, some
     people consider ‘.’, ‘(’, and ‘)’ to be delimiters, while others
     see the *note getattr(): dcc. operator and the function call
     operator(s).

     Some of Python’s operators, like ‘and’, ‘or’, and ‘not in’, use
     *note keyword: 2272. tokens rather than «symbols» (operator
     tokens).

A sequence of three consecutive periods (‘...’) has a special meaning as
an *note Ellipsis: 2311. literal.


File: python.info,  Node: Data model,  Next: Execution model,  Prev: Lexical analysis,  Up: The Python Language Reference

4.3 Data model
==============

* Menu:

* Objects, values and types: Objects values and types.
* The standard type hierarchy::
* Special method names::
* Coroutines::


File: python.info,  Node: Objects values and types,  Next: The standard type hierarchy,  Up: Data model

4.3.1 Objects, values and types
-------------------------------

'Objects' are Python’s abstraction for data.  All data in a Python
program is represented by objects or by relations between objects.  Even
code is represented by objects.

Every object has an identity, a type and a value.  An object’s
'identity' never changes once it has been created; you may think of it
as the object’s address in memory.  The *note is: 34c. operator compares
the identity of two objects; the *note id(): 162a. function returns an
integer representing its identity.

'Dettaglio dell’implementazione di CPython:' For CPython, ‘id(x)’ is the
memory address where ‘x’ is stored.

An object’s type determines the operations that the object supports
(e.g., «does it have a length?») and also defines the possible values
for objects of that type.  The *note type(): f46. function returns an
object’s type (which is an object itself).  Like its identity, an
object’s 'type' is also unchangeable.  (1)

The 'value' of some objects can change.  Objects whose value can change
are said to be 'mutable'; objects whose value is unchangeable once they
are created are called 'immutable'.  (The value of an immutable
container object that contains a reference to a mutable object can
change when the latter’s value is changed; however the container is
still considered immutable, because the collection of objects it
contains cannot be changed.  So, immutability is not strictly the same
as having an unchangeable value, it is more subtle.)  An object’s
mutability is determined by its type; for instance, numbers, strings and
tuples are immutable, while dictionaries and lists are mutable.

Objects are never explicitly destroyed; however, when they become
unreachable they may be garbage-collected.  An implementation is allowed
to postpone garbage collection or omit it altogether — it is a matter of
implementation quality how garbage collection is implemented, as long as
no objects are collected that are still reachable.

'Dettaglio dell’implementazione di CPython:' CPython currently uses a
reference-counting scheme with (optional) delayed detection of
cyclically linked garbage, which collects most objects as soon as they
become unreachable, but is not guaranteed to collect garbage containing
circular references.  See the documentation of the *note gc: 64. module
for information on controlling the collection of cyclic garbage.  Other
implementations act differently and CPython may change.  Do not depend
on immediate finalization of objects when they become unreachable (so
you should always close files explicitly).

Note that the use of the implementation’s tracing or debugging
facilities may keep objects alive that would normally be collectable.
Also note that catching an exception with a *note try: 8f9.…*note
except: 1ab. statement may keep objects alive.

Some objects contain references to «external» resources such as open
files or windows.  It is understood that these resources are freed when
the object is garbage-collected, but since garbage collection is not
guaranteed to happen, such objects also provide an explicit way to
release the external resource, usually a ‘close()’ method.  Programs are
strongly recommended to explicitly close such objects.  The *note try:
8f9.…*note finally: 1b0. statement and the *note with: 186. statement
provide convenient ways to do this.

Some objects contain references to other objects; these are called
'containers'.  Examples of containers are tuples, lists and
dictionaries.  The references are part of a container’s value.  In most
cases, when we talk about the value of a container, we imply the values,
not the identities of the contained objects; however, when we talk about
the mutability of a container, only the identities of the immediately
contained objects are implied.  So, if an immutable container (like a
tuple) contains a reference to a mutable object, its value changes if
that mutable object is changed.

Types affect almost all aspects of object behavior.  Even the importance
of object identity is affected in some sense: for immutable types,
operations that compute new values may actually return a reference to
any existing object with the same type and value, while for mutable
objects this is not allowed.  For example, after ‘a = 1; b = 1’, 'a' and
'b' may or may not refer to the same object with the value one,
depending on the implementation.  This is because *note int: 19b. is an
immutable type, so the reference to ‘1’ can be reused.  This behaviour
depends on the implementation used, so should not be relied upon, but is
something to be aware of when making use of object identity tests.
However, after ‘c = []; d = []’, 'c' and 'd' are guaranteed to refer to
two different, unique, newly created empty lists.  (Note that ‘e = f =
[]’ assigns the 'same' object to both 'e' and 'f'.)

   ---------- Footnotes ----------

   (1) It 'is' possible in some cases to change an object’s type, under
certain controlled conditions.  It generally isn’t a good idea though,
since it can lead to some very strange behaviour if it is handled
incorrectly.


File: python.info,  Node: The standard type hierarchy,  Next: Special method names,  Prev: Objects values and types,  Up: Data model

4.3.2 The standard type hierarchy
---------------------------------

Below is a list of the types that are built into Python.  Extension
modules (written in C, Java, or other languages, depending on the
implementation) can define additional types.  Future versions of Python
may add types to the type hierarchy (e.g., rational numbers, efficiently
stored arrays of integers, etc.), although such additions will often be
provided via the standard library instead.

Some of the type descriptions below contain a paragraph listing “special
attributes.” These are attributes that provide access to the
implementation and are not intended for general use.  Their definition
may change in the future.

* Menu:

* None::
* NotImplemented::
* Ellipsis::
* numbers.Number: numbers Number.
* Sequences::
* Set types::
* Mappings::
* Callable types::
* Modules: Modules<2>.
* Custom classes::
* Class instances::
* I/O objects (also known as file objects): I/O objects also known as file objects.
* Internal types::


File: python.info,  Node: None,  Next: NotImplemented,  Up: The standard type hierarchy

4.3.2.1 None
............

This type has a single value.  There is a single object with this value.
This object is accessed through the built-in name ‘None’.  It is used to
signify the absence of a value in many situations, e.g., it is returned
from functions that don’t explicitly return anything.  Its truth value
is false.


File: python.info,  Node: NotImplemented,  Next: Ellipsis,  Prev: None,  Up: The standard type hierarchy

4.3.2.2 NotImplemented
......................

This type has a single value.  There is a single object with this value.
This object is accessed through the built-in name *note NotImplemented:
1a2.  Numeric methods and rich comparison methods should return this
value if they do not implement the operation for the operands provided.
(The interpreter will then try the reflected operation, or some other
fallback, depending on the operator.)  It should not be evaluated in a
boolean context.

See *note Implementing the arithmetic operations: 231b. for more
details.

Cambiato nella versione 3.9: Evaluating *note NotImplemented: 1a2. in a
boolean context was deprecated.

Cambiato nella versione 3.14: Evaluating *note NotImplemented: 1a2. in a
boolean context now raises a *note TypeError: 198.  It previously
evaluated to *note True: e09. and emitted a *note DeprecationWarning:
1a3. since Python 3.9.


File: python.info,  Node: Ellipsis,  Next: numbers Number,  Prev: NotImplemented,  Up: The standard type hierarchy

4.3.2.3 Ellipsis
................

This type has a single value.  There is a single object with this value.
This object is accessed through the literal ‘...’ or the built-in name
‘Ellipsis’.  Its truth value is true.


File: python.info,  Node: numbers Number,  Next: Sequences,  Prev: Ellipsis,  Up: The standard type hierarchy

4.3.2.4 ‘numbers.Number’
........................

These are created by numeric literals and returned as results by
arithmetic operators and arithmetic built-in functions.  Numeric objects
are immutable; once created their value never changes.  Python numbers
are of course strongly related to mathematical numbers, but subject to
the limitations of numerical representation in computers.

The string representations of the numeric classes, computed by *note
__repr__(): 830. and *note __str__(): 831, have the following
properties:

   * They are valid numeric literals which, when passed to their class
     constructor, produce an object having the value of the original
     numeric.

   * The representation is in base 10, when possible.

   * Leading zeros, possibly excepting a single zero before a decimal
     point, are not shown.

   * Trailing zeros, possibly excepting a single zero after a decimal
     point, are not shown.

   * A sign is shown only when the number is negative.

Python distinguishes between integers, floating-point numbers, and
complex numbers:

* Menu:

* numbers.Integral: numbers Integral.
* numbers.Real (float): numbers Real float.
* numbers.Complex (complex): numbers Complex complex.


File: python.info,  Node: numbers Integral,  Next: numbers Real float,  Up: numbers Number

4.3.2.5 ‘numbers.Integral’
..........................

These represent elements from the mathematical set of integers (positive
and negative).

     Nota: 
     The rules for integer representation are intended to give the most
     meaningful interpretation of shift and mask operations involving
     negative integers.

There are two types of integers:

Integers (*note int: 19b.)

     These represent numbers in an unlimited range, subject to available
     (virtual) memory only.  For the purpose of shift and mask
     operations, a binary representation is assumed, and negative
     numbers are represented in a variant of 2’s complement which gives
     the illusion of an infinite string of sign bits extending to the
     left.

Booleans (*note bool: 3c3.)

     These represent the truth values False and True.  The two objects
     representing the values ‘False’ and ‘True’ are the only Boolean
     objects.  The Boolean type is a subtype of the integer type, and
     Boolean values behave like the values 0 and 1, respectively, in
     almost all contexts, the exception being that when converted to a
     string, the strings ‘"False"’ or ‘"True"’ are returned,
     respectively.


File: python.info,  Node: numbers Real float,  Next: numbers Complex complex,  Prev: numbers Integral,  Up: numbers Number

4.3.2.6 ‘numbers.Real’ (‘float’)
................................

These represent machine-level double precision floating-point numbers.
You are at the mercy of the underlying machine architecture (and C or
Java implementation) for the accepted range and handling of overflow.
Python does not support single-precision floating-point numbers; the
savings in processor and memory usage that are usually the reason for
using these are dwarfed by the overhead of using objects in Python, so
there is no reason to complicate the language with two kinds of
floating-point numbers.


File: python.info,  Node: numbers Complex complex,  Prev: numbers Real float,  Up: numbers Number

4.3.2.7 ‘numbers.Complex’ (‘complex’)
.....................................

These represent complex numbers as a pair of machine-level double
precision floating-point numbers.  The same caveats apply as for
floating-point numbers.  The real and imaginary parts of a complex
number ‘z’ can be retrieved through the read-only attributes ‘z.real’
and ‘z.imag’.


File: python.info,  Node: Sequences,  Next: Set types,  Prev: numbers Number,  Up: The standard type hierarchy

4.3.2.8 Sequences
.................

These represent finite ordered sets indexed by non-negative numbers.
The built-in function *note len(): 841. returns the number of items of a
sequence.  When the length of a sequence is 'n', the index set contains
the numbers 0, 1, …, 'n'-1.  Item 'i' of sequence 'a' is selected by
‘a[i]’.  Some sequences, including built-in sequences, interpret
negative subscripts by adding the sequence length.  For example, ‘a[-2]’
equals ‘a[n-2]’, the second to last item of sequence a with length ‘n’.

Sequences also support slicing: ‘a[i:j]’ selects all items with index
'k' such that 'i' ‘<=’ 'k' ‘<’ 'j'.  When used as an expression, a slice
is a sequence of the same type.  The comment above about negative
indexes also applies to negative slice positions.

Some sequences also support «extended slicing» with a third «step»
parameter: ‘a[i:j:k]’ selects all items of 'a' with index 'x' where ‘x =
i + n*k’, 'n' ‘>=’ ‘0’ and 'i' ‘<=’ 'x' ‘<’ 'j'.

Sequences are distinguished according to their mutability:

* Menu:

* Immutable sequences::
* Mutable sequences::


File: python.info,  Node: Immutable sequences,  Next: Mutable sequences,  Up: Sequences

4.3.2.9 Immutable sequences
...........................

An object of an immutable sequence type cannot change once it is
created.  (If the object contains references to other objects, these
other objects may be mutable and may be changed; however, the collection
of objects directly referenced by an immutable object cannot change.)

The following types are immutable sequences:

Strings

     A string is a sequence of values that represent Unicode code
     points.  All the code points in the range ‘U+0000 - U+10FFFF’ can
     be represented in a string.  Python doesn’t have a char type;
     instead, every code point in the string is represented as a string
     object with length ‘1’.  The built-in function *note ord(): 2323.
     converts a code point from its string form to an integer in the
     range ‘0 - 10FFFF’; *note chr(): 19d7. converts an integer in the
     range ‘0 - 10FFFF’ to the corresponding length ‘1’ string object.
     *note str.encode(): ad4. can be used to convert a *note str: 169.
     to *note bytes: 192. using the given text encoding, and *note
     bytes.decode(): ad5. can be used to achieve the opposite.

Tuples

     The items of a tuple are arbitrary Python objects.  Tuples of two
     or more items are formed by comma-separated lists of expressions.
     A tuple of one item (a “singleton”) can be formed by affixing a
     comma to an expression (an expression by itself does not create a
     tuple, since parentheses must be usable for grouping of
     expressions).  An empty tuple can be formed by an empty pair of
     parentheses.

Bytes

     A bytes object is an immutable array.  The items are 8-bit bytes,
     represented by integers in the range 0 <= x < 256.  Bytes literals
     (like ‘b'abc'’) and the built-in *note bytes(): 192. constructor
     can be used to create bytes objects.  Also, bytes objects can be
     decoded to strings via the *note decode(): ad5. method.


File: python.info,  Node: Mutable sequences,  Prev: Immutable sequences,  Up: Sequences

4.3.2.10 Mutable sequences
..........................

Mutable sequences can be changed after they are created.  The
subscription and slicing notations can be used as the target of
assignment and *note del: 1b07. (delete) statements.

     Nota: 
     The *note collections: 1e. and *note array: 8. module provide
     additional examples of mutable sequence types.

There are currently two intrinsic mutable sequence types:

Lists

     The items of a list are arbitrary Python objects.  Lists are formed
     by placing a comma-separated list of expressions in square
     brackets.  (Note that there are no special cases needed to form
     lists of length 0 or 1.)

Byte Arrays

     A bytearray object is a mutable array.  They are created by the
     built-in *note bytearray(): 344. constructor.  Aside from being
     mutable (and hence unhashable), byte arrays otherwise provide the
     same interface and functionality as immutable *note bytes: 192.
     objects.


File: python.info,  Node: Set types,  Next: Mappings,  Prev: Sequences,  Up: The standard type hierarchy

4.3.2.11 Set types
..................

These represent unordered, finite sets of unique, immutable objects.  As
such, they cannot be indexed by any subscript.  However, they can be
iterated over, and the built-in function *note len(): 841. returns the
number of items in a set.  Common uses for sets are fast membership
testing, removing duplicates from a sequence, and computing mathematical
operations such as intersection, union, difference, and symmetric
difference.

For set elements, the same immutability rules apply as for dictionary
keys.  Note that numeric types obey the normal rules for numeric
comparison: if two numbers compare equal (e.g., ‘1’ and ‘1.0’), only one
of them can be contained in a set.

There are currently two intrinsic set types:

Sets

     These represent a mutable set.  They are created by the built-in
     *note set(): 184. constructor and can be modified afterwards by
     several methods, such as *note add(): 2326.

Frozen sets

     These represent an immutable set.  They are created by the built-in
     *note frozenset(): 7f3. constructor.  As a frozenset is immutable
     and *note hashable: 825, it can be used again as an element of
     another set, or as a dictionary key.


File: python.info,  Node: Mappings,  Next: Callable types,  Prev: Set types,  Up: The standard type hierarchy

4.3.2.12 Mappings
.................

These represent finite sets of objects indexed by arbitrary index sets.
The subscript notation ‘a[k]’ selects the item indexed by ‘k’ from the
mapping ‘a’; this can be used in expressions and as the target of
assignments or *note del: 1b07. statements.  The built-in function *note
len(): 841. returns the number of items in a mapping.

There is currently a single intrinsic mapping type:

* Menu:

* Dictionaries::


File: python.info,  Node: Dictionaries,  Up: Mappings

4.3.2.13 Dictionaries
.....................

These represent finite sets of objects indexed by nearly arbitrary
values.  The only types of values not acceptable as keys are values
containing lists or dictionaries or other mutable types that are
compared by value rather than by object identity, the reason being that
the efficient implementation of dictionaries requires a key’s hash value
to remain constant.  Numeric types used for keys obey the normal rules
for numeric comparison: if two numbers compare equal (e.g., ‘1’ and
‘1.0’) then they can be used interchangeably to index the same
dictionary entry.

Dictionaries preserve insertion order, meaning that keys will be
produced in the same order they were added sequentially over the
dictionary.  Replacing an existing key does not change the order,
however removing a key and re-inserting it will add it to the end
instead of keeping its old place.

Dictionaries are mutable; they can be created by the ‘{}’ notation (see
section *note Dictionary displays: f81.).

The extension modules *note dbm.ndbm: 38. and *note dbm.gnu: 37. provide
additional examples of mapping types, as does the *note collections: 1e.
module.

Cambiato nella versione 3.7: Dictionaries did not preserve insertion
order in versions of Python before 3.6.  In CPython 3.6, insertion order
was preserved, but it was considered an implementation detail at that
time rather than a language guarantee.


File: python.info,  Node: Callable types,  Next: Modules<2>,  Prev: Mappings,  Up: The standard type hierarchy

4.3.2.14 Callable types
.......................

These are the types to which the function call operation (see section
*note Calls: f7f.) can be applied:

* Menu:

* User-defined functions::
* Instance methods::
* Generator functions::
* Coroutine functions::
* Asynchronous generator functions::
* Built-in functions::
* Built-in methods::
* Classes::
* Class Instances::


File: python.info,  Node: User-defined functions,  Next: Instance methods,  Up: Callable types

4.3.2.15 User-defined functions
...............................

A user-defined function object is created by a function definition (see
section *note Function definitions: 2002.).  It should be called with an
argument list containing the same number of items as the function’s
formal parameter list.

* Menu:

* Special read-only attributes::
* Special writable attributes::


File: python.info,  Node: Special read-only attributes,  Next: Special writable attributes,  Up: User-defined functions

4.3.2.16 Special read-only attributes
.....................................

Attribute                                              Meaning
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
 -- Attributo: function.__builtins__                   A reference to the *note dictionary: 183. that holds
                                                       the function’s builtins namespace.
                                                       
                                                       Added in version 3.10.
                                                       
                                                       
 -- Attributo: function.__globals__                    A reference to the *note dictionary: 183. that holds
                                                       the function’s *note global variables: 232d. – the
                                                       global namespace of the module in which the function
                                                       was defined.
                                                       
                                                       
 -- Attributo: function.__closure__                    ‘None’ or a *note tuple: 614. of cells that contain
                                                       bindings for the names specified in the
                                                       *note co_freevars: 232e. attribute of the function’s
                                                       *note code object: 59d.
                                                       
                                                       A cell object has the attribute ‘cell_contents’.
                                                       This can be used to get the value of the cell, as
                                                       well as set the value.
                                                       


File: python.info,  Node: Special writable attributes,  Prev: Special read-only attributes,  Up: User-defined functions

4.3.2.17 Special writable attributes
....................................

Most of these attributes check the type of the assigned value:

Attribute                                              Meaning
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
 -- Attributo: function.__doc__                        The function’s documentation string, or ‘None’ if
                                                       unavailable.
                                                       
                                                       
 -- Attributo: function.__name__                       The function’s name.  See also:
                                                       *note __name__ attributes: 1268.
                                                       
                                                       
 -- Attributo: function.__qualname__                   The function’s *note qualified name: 1d0c.  See
                                                       also: *note __qualname__ attributes: 1267.
                                                       
                                                       Added in version 3.3.
                                                       
                                                       
 -- Attributo: function.__module__                     The name of the module the function was defined in,
                                                       or ‘None’ if unavailable.
                                                       
                                                       
 -- Attributo: function.__defaults__                   A *note tuple: 614. containing default
                                                       *note parameter: 2332. values for those parameters
                                                       that have defaults, or ‘None’ if no parameters have
                                                       a default value.
                                                       
                                                       
 -- Attributo: function.__code__                       The *note code object: 4e7. representing the
                                                       compiled function body.
                                                       
                                                       
 -- Attributo: function.__dict__                       The namespace supporting arbitrary function
                                                       attributes.  See also:
                                                       *note __dict__ attributes: 77e.
                                                       
                                                       
 -- Attributo: function.__annotations__                A *note dictionary: 183. containing annotations of
                                                       *note parameters: 2332.  The keys of the dictionary
                                                       are the parameter names, and ‘'return'’ for the
                                                       return annotation, if provided.  See also:
                                                       *note object.__annotations__: 458.
                                                       
                                                       Cambiato nella versione 3.14: Annotations are now
                                                       *note lazily evaluated: 686.  See PEP 649(1).
                                                       
                                                       
 -- Attributo: function.__annotate__                   The *note annotate function: 15d. for this function,
                                                       or ‘None’ if the function has no annotations.  See
                                                       *note object.__annotate__: 196b.
                                                       
                                                       Added in version 3.14.
                                                       
                                                       
 -- Attributo: function.__kwdefaults__                 A *note dictionary: 183. containing defaults for
                                                       keyword-only *note parameters: 2332.
                                                       
                                                       
 -- Attributo: function.__type_params__                A *note tuple: 614. containing the
                                                       *note type parameters: 5ad. of a
                                                       *note generic function: 683.
                                                       
                                                       Added in version 3.12.
                                                       

Function objects also support getting and setting arbitrary attributes,
which can be used, for example, to attach metadata to functions.
Regular attribute dot-notation is used to get and set such attributes.

'Dettaglio dell’implementazione di CPython:' CPython’s current
implementation only supports function attributes on user-defined
functions.  Function attributes on *note built-in functions: 2335. may
be supported in the future.

Additional information about a function’s definition can be retrieved
from its *note code object: 4e7. (accessible via the *note __code__:
59d. attribute).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0649/


File: python.info,  Node: Instance methods,  Next: Generator functions,  Prev: User-defined functions,  Up: Callable types

4.3.2.18 Instance methods
.........................

An instance method object combines a class, a class instance and any
callable object (normally a user-defined function).

Special read-only attributes:

 -- Attributo: method.__self__                         Refers to the class instance object to which the
                                                       method is *note bound: 2337.
                                                       
                                                       
 -- Attributo: method.__func__                         Refers to the original *note function object: 59c.
                                                       
                                                       
 -- Attributo: method.__doc__                          The method’s documentation (same as
                                                       *note method.__func__.__doc__: 13e1.).  A
                                                       *note string: 169. if the original function had a
                                                       docstring, else ‘None’.
                                                       
                                                       
 -- Attributo: method.__name__                         The name of the method (same as
                                                       *note method.__func__.__name__: 14dc.)
                                                       
                                                       
 -- Attributo: method.__module__                       The name of the module the method was defined in, or
                                                       ‘None’ if unavailable.
                                                       

Methods also support accessing (but not setting) the arbitrary function
attributes on the underlying *note function object: 59c.

User-defined method objects may be created when getting an attribute of
a class (perhaps via an instance of that class), if that attribute is a
user-defined *note function object: 59c. or a *note classmethod: 48f.
object.  When an instance method object is created by retrieving a
user-defined *note function object: 59c. from a class via one of its
instances, its *note __self__: 15d0. attribute is the instance, and the
method object is said to be 'bound'.  The new method’s *note __func__:
1504. attribute is the original function object.

When an instance method object is created by retrieving a *note
classmethod: 48f. object from a class or instance, its *note __self__:
15d0. attribute is the class itself, and its *note __func__: 1504.
attribute is the function object underlying the class method.

When an instance method object is called, the underlying function (*note
__func__: 1504.) is called, inserting the class instance (*note
__self__: 15d0.) in front of the argument list.  For instance, when ‘C’
is a class which contains a definition for a function ‘f()’, and ‘x’ is
an instance of ‘C’, calling ‘x.f(1)’ is equivalent to calling ‘C.f(x,
1)’.

When an instance method object is derived from a *note classmethod: 48f.
object, the «class instance» stored in *note __self__: 15d0. will
actually be the class itself, so that calling either ‘x.f(1)’ or
‘C.f(1)’ is equivalent to calling ‘f(C,1)’ where ‘f’ is the underlying
function.

It is important to note that user-defined functions which are attributes
of a class instance are not converted to bound methods; this 'only'
happens when the function is an attribute of the class.


File: python.info,  Node: Generator functions,  Next: Coroutine functions,  Prev: Instance methods,  Up: Callable types

4.3.2.19 Generator functions
............................

A function or method which uses the *note yield: bc4. statement (see
section *note The yield statement: bc4.) is called a 'generator
function'.  Such a function, when called, always returns an *note
iterator: 4c9. object which can be used to execute the body of the
function: calling the iterator’s *note iterator.__next__(): 14d5. method
will cause the function to execute until it provides a value using the
‘yield’ statement.  When the function executes a *note return: 1af.
statement or falls off the end, a *note StopIteration: df7. exception is
raised and the iterator will have reached the end of the set of values
to be returned.


File: python.info,  Node: Coroutine functions,  Next: Asynchronous generator functions,  Prev: Generator functions,  Up: Callable types

4.3.2.20 Coroutine functions
............................

A function or method which is defined using *note async def: 7ee. is
called a 'coroutine function'.  Such a function, when called, returns a
*note coroutine: 6ba. object.  It may contain *note await: 18d.
expressions, as well as *note async with: 185. and *note async for: ca3.
statements.  See also the *note Coroutine Objects: 233d. section.


File: python.info,  Node: Asynchronous generator functions,  Next: Built-in functions,  Prev: Coroutine functions,  Up: Callable types

4.3.2.21 Asynchronous generator functions
.........................................

A function or method which is defined using *note async def: 7ee. and
which uses the *note yield: bc4. statement is called a 'asynchronous
generator function'.  Such a function, when called, returns an *note
asynchronous iterator: 4c8. object which can be used in an *note async
for: ca3. statement to execute the body of the function.

Calling the asynchronous iterator’s *note aiterator.__anext__: 186a.
method will return an *note awaitable: 4ca. which when awaited will
execute until it provides a value using the *note yield: bc4.
expression.  When the function executes an empty *note return: 1af.
statement or falls off the end, a *note StopAsyncIteration: 1df7.
exception is raised and the asynchronous iterator will have reached the
end of the set of values to be yielded.


File: python.info,  Node: Built-in functions,  Next: Built-in methods,  Prev: Asynchronous generator functions,  Up: Callable types

4.3.2.22 Built-in functions
...........................

A built-in function object is a wrapper around a C function.  Examples
of built-in functions are *note len(): 841. and *note math.sin(): 16c5.
(*note math: 92. is a standard built-in module).  The number and type of
the arguments are determined by the C function.  Special read-only
attributes:

   * ‘__doc__’ is the function’s documentation string, or ‘None’ if
     unavailable.  See *note function.__doc__: 13e1.

   * ‘__name__’ is the function’s name.  See *note function.__name__:
     14dc.

   * ‘__self__’ is set to ‘None’ (but see the next item).

   * ‘__module__’ is the name of the module the function was defined in
     or ‘None’ if unavailable.  See *note function.__module__: 2331.


File: python.info,  Node: Built-in methods,  Next: Classes,  Prev: Built-in functions,  Up: Callable types

4.3.2.23 Built-in methods
.........................

This is really a different disguise of a built-in function, this time
containing an object passed to the C function as an implicit extra
argument.  An example of a built-in method is ‘alist.append()’, assuming
'alist' is a list object.  In this case, the special read-only attribute
‘__self__’ is set to the object denoted by 'alist'.  (The attribute has
the same semantics as it does with *note other instance methods: 15d0.)


File: python.info,  Node: Classes,  Next: Class Instances,  Prev: Built-in methods,  Up: Callable types

4.3.2.24 Classes
................

Classes are callable.  These objects normally act as factories for new
instances of themselves, but variations are possible for class types
that override *note __new__(): 7a1.  The arguments of the call are
passed to ‘__new__()’ and, in the typical case, to *note __init__():
8c0. to initialize the new instance.


File: python.info,  Node: Class Instances,  Prev: Classes,  Up: Callable types

4.3.2.25 Class Instances
........................

Instances of arbitrary classes can be made callable by defining a *note
__call__(): 77b. method in their class.


File: python.info,  Node: Modules<2>,  Next: Custom classes,  Prev: Callable types,  Up: The standard type hierarchy

4.3.2.26 Modules
................

Modules are a basic organizational unit of Python code, and are created
by the *note import system: 2347. as invoked either by the *note import:
7f9. statement, or by calling functions such as *note
importlib.import_module(): 73d. and built-in *note __import__(): ad3.  A
module object has a namespace implemented by a *note dictionary: 183.
object (this is the dictionary referenced by the *note __globals__:
14db. attribute of functions defined in the module).  Attribute
references are translated to lookups in this dictionary, e.g., ‘m.x’ is
equivalent to ‘m.__dict__["x"]’.  A module object does not contain the
code object used to initialize the module (since it isn’t needed once
the initialization is done).

Attribute assignment updates the module’s namespace dictionary, e.g.,
‘m.x = 1’ is equivalent to ‘m.__dict__["x"] = 1’.

* Menu:

* Import-related attributes on module objects::
* Other writable attributes on module objects::
* Module dictionaries::


File: python.info,  Node: Import-related attributes on module objects,  Next: Other writable attributes on module objects,  Up: Modules<2>

4.3.2.27 Import-related attributes on module objects
....................................................

Module objects have the following attributes that relate to the *note
import system: 2347.  When a module is created using the machinery
associated with the import system, these attributes are filled in based
on the module’s *note spec: 234a, before the *note loader: 1a10.
executes and loads the module.

To create a module dynamically rather than using the import system, it’s
recommended to use *note importlib.util.module_from_spec(): 1015, which
will set the various import-controlled attributes to appropriate values.
It’s also possible to use the *note types.ModuleType: 1016. constructor
to create modules directly, but this technique is more error-prone, as
most attributes must be manually set on the module object after it has
been created when using this approach.

     Attenzione: With the exception of *note __name__: 1593, it is
     'strongly' recommended that you rely on *note __spec__: 234b. and
     its attributes instead of any of the other individual attributes
     listed in this subsection.  Note that updating an attribute on
     ‘__spec__’ will not update the corresponding attribute on the
     module itself:

          >>> import typing
          >>> typing.__name__, typing.__spec__.name
          ('typing', 'typing')
          >>> typing.__spec__.name = 'spelling'
          >>> typing.__name__, typing.__spec__.name
          ('typing', 'spelling')
          >>> typing.__name__ = 'keyboard_smashing'
          >>> typing.__name__, typing.__spec__.name
          ('keyboard_smashing', 'spelling')

 -- Attributo: module.__name__

     The name used to uniquely identify the module in the import system.
     For a directly executed module, this will be set to ‘"__main__"’.

     This attribute must be set to the fully qualified name of the
     module.  It is expected to match the value of *note
     module.__spec__.name: 234c.

 -- Attributo: module.__spec__

     A record of the module’s import-system-related state.

     Set to the *note module spec: 2255. that was used when importing
     the module.  See *note Module specs: 234d. for more details.

     Added in version 3.4.

 -- Attributo: module.__package__

     The *note package: 233. a module belongs to.

     If the module is top-level (that is, not a part of any specific
     package) then the attribute should be set to ‘''’ (the empty
     string).  Otherwise, it should be set to the name of the module’s
     package (which can be equal to *note module.__name__: 1593. if the
     module itself is a package).  See PEP 366(1) for further details.

     This attribute is used instead of *note __name__: 1593. to
     calculate explicit relative imports for main modules.  It defaults
     to ‘None’ for modules created dynamically using the *note
     types.ModuleType: 1016. constructor; use *note
     importlib.util.module_from_spec(): 1015. instead to ensure the
     attribute is set to a *note str: 169.

     It is 'strongly' recommended that you use *note
     module.__spec__.parent: 324. instead of ‘module.__package__’.
     *note __package__: 323. is now only used as a fallback if
     ‘__spec__.parent’ is not set, and this fallback path is deprecated.

     Cambiato nella versione 3.4: This attribute now defaults to ‘None’
     for modules created dynamically using the *note types.ModuleType:
     1016. constructor.  Previously the attribute was optional.

     Cambiato nella versione 3.6: The value of ‘__package__’ is expected
     to be the same as *note __spec__.parent: 324.  *note __package__:
     323. is now only used as a fallback during import resolution if
     ‘__spec__.parent’ is not defined.

     Cambiato nella versione 3.10: *note ImportWarning: 71f. is raised
     if an import resolution falls back to ‘__package__’ instead of
     *note __spec__.parent: 324.

     Cambiato nella versione 3.12: Raise *note DeprecationWarning: 1a3.
     instead of *note ImportWarning: 71f. when falling back to
     ‘__package__’ during import resolution.

     Deprecated since version 3.13, will be removed in version 3.15:
     ‘__package__’ will cease to be set or taken into consideration by
     the import system or standard library.

 -- Attributo: module.__loader__

     The *note loader: 1a10. object that the import machinery used to
     load the module.

     This attribute is mostly useful for introspection, but can be used
     for additional loader-specific functionality, for example getting
     data associated with a loader.

     ‘__loader__’ defaults to ‘None’ for modules created dynamically
     using the *note types.ModuleType: 1016. constructor; use *note
     importlib.util.module_from_spec(): 1015. instead to ensure the
     attribute is set to a *note loader: 1a10. object.

     It is 'strongly' recommended that you use *note
     module.__spec__.loader: 33c. instead of ‘module.__loader__’.

     Cambiato nella versione 3.4: This attribute now defaults to ‘None’
     for modules created dynamically using the *note types.ModuleType:
     1016. constructor.  Previously the attribute was optional.

     Deprecated since version 3.12, will be removed in version 3.16:
     Setting ‘__loader__’ on a module while failing to set
     ‘__spec__.loader’ is deprecated.  In Python 3.16, ‘__loader__’ will
     cease to be set or taken into consideration by the import system or
     the standard library.

 -- Attributo: module.__path__

     A (possibly empty) *note sequence: 717. of strings enumerating the
     locations where the package’s submodules will be found.
     Non-package modules should not have a ‘__path__’ attribute.  See
     *note __path__ attributes on modules: 234e. for more details.

     It is 'strongly' recommended that you use *note
     module.__spec__.submodule_search_locations: 234f. instead of
     ‘module.__path__’.

 -- Attributo: module.__file__

 -- Attributo: module.__cached__

     ‘__file__’ and ‘__cached__’ are both optional attributes that may
     or may not be set.  Both attributes should be a *note str: 169.
     when they are available.

     ‘__file__’ indicates the pathname of the file from which the module
     was loaded (if loaded from a file), or the pathname of the shared
     library file for extension modules loaded dynamically from a shared
     library.  It might be missing for certain types of modules, such as
     C modules that are statically linked into the interpreter, and the
     *note import system: 2347. may opt to leave it unset if it has no
     semantic meaning (for example, a module loaded from a database).

     If ‘__file__’ is set then the ‘__cached__’ attribute might also be
     set, which is the path to any compiled version of the code (for
     example, a byte-compiled file).  The file does not need to exist to
     set this attribute; the path can simply point to where the compiled
     file 'would' exist (see PEP 3147(2)).

     Note that ‘__cached__’ may be set even if ‘__file__’ is not set.
     However, that scenario is quite atypical.  Ultimately, the *note
     loader: 1a10. is what makes use of the module spec provided by the
     *note finder: 2351. (from which ‘__file__’ and ‘__cached__’ are
     derived).  So if a loader can load from a cached module but
     otherwise does not load from a file, that atypical scenario may be
     appropriate.

     It is 'strongly' recommended that you use *note
     module.__spec__.cached: 322. instead of ‘module.__cached__’.

     Deprecated since version 3.13, will be removed in version 3.15:
     Setting ‘__cached__’ on a module while failing to set
     ‘__spec__.cached’ is deprecated.  In Python 3.15, ‘__cached__’ will
     cease to be set or taken into consideration by the import system or
     standard library.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0366/

   (2) https://peps.python.org/pep-3147/


File: python.info,  Node: Other writable attributes on module objects,  Next: Module dictionaries,  Prev: Import-related attributes on module objects,  Up: Modules<2>

4.3.2.28 Other writable attributes on module objects
....................................................

As well as the import-related attributes listed above, module objects
also have the following writable attributes:

 -- Attributo: module.__doc__

     The module’s documentation string, or ‘None’ if unavailable.  See
     also: *note __doc__ attributes: b23.

 -- Attributo: module.__annotations__

     A dictionary containing *note variable annotations: f53. collected
     during module body execution.  For best practices on working with
     ‘__annotations__’, see *note annotationlib: 6.

     Cambiato nella versione 3.14: Annotations are now *note lazily
     evaluated: 686.  See PEP 649(1).

 -- Attributo: module.__annotate__

     The *note annotate function: 15d. for this module, or ‘None’ if the
     module has no annotations.  See also: *note __annotate__: 196b.
     attributes.

     Added in version 3.14.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0649/


File: python.info,  Node: Module dictionaries,  Prev: Other writable attributes on module objects,  Up: Modules<2>

4.3.2.29 Module dictionaries
............................

Module objects also have the following special read-only attribute:

 -- Attributo: module.__dict__

     The module’s namespace as a dictionary object.  Uniquely among the
     attributes listed here, ‘__dict__’ cannot be accessed as a global
     variable from within a module; it can only be accessed as an
     attribute on module objects.

     'Dettaglio dell’implementazione di CPython:' Because of the way
     CPython clears module dictionaries, the module dictionary will be
     cleared when the module falls out of scope even if the dictionary
     still has live references.  To avoid this, copy the dictionary or
     keep the module around while using its dictionary directly.


File: python.info,  Node: Custom classes,  Next: Class instances,  Prev: Modules<2>,  Up: The standard type hierarchy

4.3.2.30 Custom classes
.......................

Custom class types are typically created by class definitions (see
section *note Class definitions: 14df.).  A class has a namespace
implemented by a dictionary object.  Class attribute references are
translated to lookups in this dictionary, e.g., ‘C.x’ is translated to
‘C.__dict__["x"]’ (although there are a number of hooks which allow for
other means of locating attributes).  When the attribute name is not
found there, the attribute search continues in the base classes.  This
search of the base classes uses the C3 method resolution order which
behaves correctly even in the presence of “diamond” inheritance
structures where there are multiple inheritance paths leading back to a
common ancestor.  Additional details on the C3 MRO used by Python can be
found at *note The Python 2.3 Method Resolution Order: 16b1.

When a class attribute reference (for class ‘C’, say) would yield a
class method object, it is transformed into an instance method object
whose *note __self__: 15d0. attribute is ‘C’.  When it would yield a
*note staticmethod: 453. object, it is transformed into the object
wrapped by the static method object.  See section *note Implementing
Descriptors: e4b. for another way in which attributes retrieved from a
class may differ from those actually contained in its *note __dict__:
77e.

Class attribute assignments update the class’s dictionary, never the
dictionary of a base class.

A class object can be called (see above) to yield a class instance (see
below).

* Menu:

* Special attributes::
* Special methods::


File: python.info,  Node: Special attributes,  Next: Special methods,  Up: Custom classes

4.3.2.31 Special attributes
...........................

Attribute                                              Meaning
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
 -- Attributo: type.__name__                           The class’s name.  See also:
                                                       *note __name__ attributes: 1268.
                                                       
                                                       
 -- Attributo: type.__qualname__                       The class’s *note qualified name: 1d0c.  See also:
                                                       *note __qualname__ attributes: 1267.
                                                       
                                                       
 -- Attributo: type.__module__                         The name of the module in which the class was
                                                       defined.
                                                       
                                                       
 -- Attributo: type.__dict__                           A *note mapping proxy: 699. providing a read-only
                                                       view of the class’s namespace.  See also:
                                                       *note __dict__ attributes: 77e.
                                                       
                                                       
 -- Attributo: type.__bases__                          A *note tuple: 614. containing the class’s bases.
                                                       In most cases, for a class defined as ‘class X(A, B,
                                                       C)’, ‘X.__bases__’ will be exactly equal to ‘(A, B,
                                                       C)’.
                                                       
                                                       
 -- Attributo: type.__base__                           'Dettaglio dell’implementazione di CPython:' The
                                                       single base class in the inheritance chain that is
                                                       responsible for the memory layout of instances.
                                                       This attribute corresponds to *note tp_base: 235c.
                                                       at the C level.
                                                       
                                                       
 -- Attributo: type.__doc__                            The class’s documentation string, or ‘None’ if
                                                       undefined.  Not inherited by subclasses.
                                                       
                                                       
 -- Attributo: type.__annotations__                    A dictionary containing
                                                       *note variable annotations: f53. collected during
                                                       class body execution.  See also:
                                                       *note __annotations__ attributes: 458.
                                                       
                                                       For best practices on working with
                                                       *note __annotations__: 458, please see
                                                       *note annotationlib: 6.  Use
                                                       *note annotationlib.get_annotations(): 459. instead
                                                       of accessing this attribute directly.
                                                       
                                                            Avvertimento: Accessing the ‘__annotations__’
                                                            attribute directly on a class object may return
                                                            annotations for the wrong class, specifically
                                                            in certain cases where the class, its base
                                                            class, or a metaclass is defined under ‘from
                                                            __future__ import annotations’.  See 749(1) for
                                                            details.
                                                       
                                                            This attribute does not exist on certain
                                                            builtin classes.  On user-defined classes
                                                            without ‘__annotations__’, it is an empty
                                                            dictionary.
                                                       
                                                       Cambiato nella versione 3.14: Annotations are now
                                                       *note lazily evaluated: 686.  See PEP 649(2).
                                                       
                                                       
 -- Metodo: type.__annotate__ ()                       The *note annotate function: 15d. for this class, or
                                                       ‘None’ if the class has no annotations.  See also:
                                                       *note __annotate__ attributes: 196b.
                                                       
                                                       Added in version 3.14.
                                                       
                                                       
 -- Attributo: type.__type_params__                    A *note tuple: 614. containing the
                                                       *note type parameters: 5ad. of a
                                                       *note generic class: 682.
                                                       
                                                       Added in version 3.12.
                                                       
                                                       
 -- Attributo: type.__static_attributes__              A *note tuple: 614. containing names of attributes
                                                       of this class which are assigned through ‘self.X’
                                                       from any function in its body.
                                                       
                                                       Added in version 3.13.
                                                       
                                                       
 -- Attributo: type.__firstlineno__                    The line number of the first line of the class
                                                       definition, including decorators.  Setting the
                                                       *note __module__: 617. attribute removes the
                                                       ‘__firstlineno__’ item from the type’s dictionary.
                                                       
                                                       Added in version 3.13.
                                                       
                                                       
 -- Attributo: type.__mro__                            The *note tuple: 614. of classes that are considered
                                                       when looking for base classes during method
                                                       resolution.
                                                       

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0749/#pep749-metaclasses

   (2) https://peps.python.org/pep-0649/


File: python.info,  Node: Special methods,  Prev: Special attributes,  Up: Custom classes

4.3.2.32 Special methods
........................

In addition to the special attributes described above, all Python
classes also have the following two methods available:

 -- Metodo: type.mro ()

     This method can be overridden by a metaclass to customize the
     method resolution order for its instances.  It is called at class
     instantiation, and its result is stored in *note __mro__: 235e.

 -- Metodo: type.__subclasses__ ()

     Each class keeps a list of weak references to its immediate
     subclasses.  This method returns a list of all those references
     still alive.  The list is in definition order.  Example:

          >>> class A: pass
          >>> class B(A): pass
          >>> A.__subclasses__()
          [<class 'B'>]


File: python.info,  Node: Class instances,  Next: I/O objects also known as file objects,  Prev: Custom classes,  Up: The standard type hierarchy

4.3.2.33 Class instances
........................

A class instance is created by calling a class object (see above).  A
class instance has a namespace implemented as a dictionary which is the
first place in which attribute references are searched.  When an
attribute is not found there, and the instance’s class has an attribute
by that name, the search continues with the class attributes.  If a
class attribute is found that is a user-defined function object, it is
transformed into an instance method object whose *note __self__: 15d0.
attribute is the instance.  Static method and class method objects are
also transformed; see above under «Classes».  See section *note
Implementing Descriptors: e4b. for another way in which attributes of a
class retrieved via its instances may differ from the objects actually
stored in the class’s *note __dict__: 77e.  If no class attribute is
found, and the object’s class has a *note __getattr__(): 6fb. method,
that is called to satisfy the lookup.

Attribute assignments and deletions update the instance’s dictionary,
never a class’s dictionary.  If the class has a *note __setattr__():
2362. or *note __delattr__(): 2363. method, this is called instead of
updating the instance dictionary directly.

Class instances can pretend to be numbers, sequences, or mappings if
they have methods with certain special names.  See section *note Special
method names: e6a.

* Menu:

* Special attributes: Special attributes<2>.


File: python.info,  Node: Special attributes<2>,  Up: Class instances

4.3.2.34 Special attributes
...........................

 -- Attributo: object.__class__

     The class to which a class instance belongs.

 -- Attributo: object.__dict__

     A dictionary or other mapping object used to store an object’s
     (writable) attributes.  Not all instances have a ‘__dict__’
     attribute; see the section on *note __slots__: 2365. for more
     details.


File: python.info,  Node: I/O objects also known as file objects,  Next: Internal types,  Prev: Class instances,  Up: The standard type hierarchy

4.3.2.35 I/O objects (also known as file objects)
.................................................

A *note file object: 13cb. represents an open file.  Various shortcuts
are available to create file objects: the *note open(): 316. built-in
function, and also *note os.popen(): 31a, *note os.fdopen(): 2367, and
the *note makefile(): 13a7. method of socket objects (and perhaps by
other functions or methods provided by extension modules).

The objects ‘sys.stdin’, ‘sys.stdout’ and ‘sys.stderr’ are initialized
to file objects corresponding to the interpreter’s standard input,
output and error streams; they are all open in text mode and therefore
follow the interface defined by the *note io.TextIOBase: 8a5. abstract
class.


File: python.info,  Node: Internal types,  Prev: I/O objects also known as file objects,  Up: The standard type hierarchy

4.3.2.36 Internal types
.......................

A few types used internally by the interpreter are exposed to the user.
Their definitions may change with future versions of the interpreter,
but they are mentioned here for completeness.

* Menu:

* Code objects::
* Frame objects::
* Traceback objects::
* Slice objects::
* Static method objects::
* Class method objects::


File: python.info,  Node: Code objects,  Next: Frame objects,  Up: Internal types

4.3.2.37 Code objects
.....................

Code objects represent 'byte-compiled' executable Python code, or *note
bytecode: 4ab.  The difference between a code object and a function
object is that the function object contains an explicit reference to the
function’s globals (the module in which it was defined), while a code
object contains no context; also the default argument values are stored
in the function object, not in the code object (because they represent
values calculated at run-time).  Unlike function objects, code objects
are immutable and contain no references (directly or indirectly) to
mutable objects.

* Menu:

* Special read-only attributes: Special read-only attributes<2>.
* Methods on code objects::


File: python.info,  Node: Special read-only attributes<2>,  Next: Methods on code objects,  Up: Code objects

4.3.2.38 Special read-only attributes
.....................................

 -- Attributo: codeobject.co_name                      The function name
                                                       
                                                       
 -- Attributo: codeobject.co_qualname                  The fully qualified function name
                                                       
                                                       Added in version 3.11.
                                                       
                                                       
 -- Attributo: codeobject.co_argcount                  The total number of positional
                                                       *note parameters: 2332. (including positional-only
                                                       parameters and parameters with default values) that
                                                       the function has
                                                       
                                                       
 -- Attributo: codeobject.co_posonlyargcount           The number of positional-only
                                                       *note parameters: 2332. (including arguments with
                                                       default values) that the function has
                                                       
                                                       
 -- Attributo: codeobject.co_kwonlyargcount            The number of keyword-only *note parameters: 2332.
                                                       (including arguments with default values) that the
                                                       function has
                                                       
                                                       
 -- Attributo: codeobject.co_nlocals                   The number of *note local variables: 232d. used by
                                                       the function (including parameters)
                                                       
                                                       
 -- Attributo: codeobject.co_varnames                  A *note tuple: 614. containing the names of the
                                                       local variables in the function (starting with the
                                                       parameter names)
                                                       
                                                       
 -- Attributo: codeobject.co_cellvars                  A *note tuple: 614. containing the names of
                                                       *note local variables: 232d. that are referenced
                                                       from at least one *note nested scope: 2373. inside
                                                       the function
                                                       
                                                       
 -- Attributo: codeobject.co_freevars                  A *note tuple: 614. containing the names of
                                                       *note free (closure) variables: 187b. that a
                                                       *note nested scope: 2373. references in an outer
                                                       scope.  See also *note function.__closure__: 14d8.
                                                       
                                                       Note: references to global and builtin names are
                                                       'not' included.
                                                       
                                                       
 -- Attributo: codeobject.co_code                      A string representing the sequence of
                                                       *note bytecode: 4ab. instructions in the function
                                                       
                                                       
 -- Attributo: codeobject.co_consts                    A *note tuple: 614. containing the literals used by
                                                       the *note bytecode: 4ab. in the function
                                                       
                                                       
 -- Attributo: codeobject.co_names                     A *note tuple: 614. containing the names used by the
                                                       *note bytecode: 4ab. in the function
                                                       
                                                       
 -- Attributo: codeobject.co_filename                  The name of the file from which the code was
                                                       compiled
                                                       
                                                       
 -- Attributo: codeobject.co_firstlineno               The line number of the first line of the function
                                                       
                                                       
 -- Attributo: codeobject.co_lnotab                    A string encoding the mapping from
                                                       *note bytecode: 4ab. offsets to line numbers.  For
                                                       details, see the source code of the interpreter.
                                                       
                                                       Deprecato dalla versione 3.12: This attribute of
                                                       code objects is deprecated, and may be removed in
                                                       Python 3.15.
                                                       
                                                       
 -- Attributo: codeobject.co_stacksize                 The required stack size of the code object
                                                       
                                                       
 -- Attributo: codeobject.co_flags                     An *note integer: 19b. encoding a number of flags
                                                       for the interpreter.
                                                       

The following flag bits are defined for *note co_flags: 18c3.: bit
‘0x04’ is set if the function uses the ‘*arguments’ syntax to accept an
arbitrary number of positional arguments; bit ‘0x08’ is set if the
function uses the ‘**keywords’ syntax to accept arbitrary keyword
arguments; bit ‘0x20’ is set if the function is a generator.  See *note
Code Objects Bit Flags: 2378. for details on the semantics of each flags
that might be present.

Future feature declarations (for example, ‘from __future__ import
division’) also use bits in *note co_flags: 18c3. to indicate whether a
code object was compiled with a particular feature enabled.  See *note
compiler_flag: 2379.

Other bits in *note co_flags: 18c3. are reserved for internal use.

If a code object represents a function and has a docstring, the *note
CO_HAS_DOCSTRING: 237a. bit is set in *note co_flags: 18c3. and the
first item in *note co_consts: 1883. is the docstring of the function.


File: python.info,  Node: Methods on code objects,  Prev: Special read-only attributes<2>,  Up: Code objects

4.3.2.39 Methods on code objects
................................

 -- Metodo: codeobject.co_positions ()

     Returns an iterable over the source code positions of each *note
     bytecode: 4ab. instruction in the code object.

     The iterator returns *note tuple: 614.s containing the
     ‘(start_line, end_line, start_column, end_column)’.  The 'i-th'
     tuple corresponds to the position of the source code that compiled
     to the 'i-th' code unit.  Column information is 0-indexed utf-8
     byte offsets on the given source line.

     This positional information can be missing.  A non-exhaustive lists
     of cases where this may happen:

        - Running the interpreter with *note -X: 16f. ‘no_debug_ranges’.

        - Loading a pyc file compiled while using *note -X: 16f.
          ‘no_debug_ranges’.

        - Position tuples corresponding to artificial instructions.

        - Line and column numbers that can’t be represented due to
          implementation specific limitations.

     When this occurs, some or all of the tuple elements can be *note
     None: 886.

     Added in version 3.11.

          Nota: This feature requires storing column positions in code
          objects which may result in a small increase of disk usage of
          compiled Python files or interpreter memory usage.  To avoid
          storing the extra information and/or deactivate printing the
          extra traceback information, the *note -X: 16f.
          ‘no_debug_ranges’ command line flag or the *note
          PYTHONNODEBUGRANGES: 7d4. environment variable can be used.

 -- Metodo: codeobject.co_lines ()

     Returns an iterator that yields information about successive ranges
     of *note bytecode: 4ab.s.  Each item yielded is a ‘(start, end,
     lineno)’ *note tuple: 614.:

        * ‘start’ (an *note int: 19b.) represents the offset (inclusive)
          of the start of the *note bytecode: 4ab. range

        * ‘end’ (an *note int: 19b.) represents the offset (exclusive)
          of the end of the *note bytecode: 4ab. range

        * ‘lineno’ is an *note int: 19b. representing the line number of
          the *note bytecode: 4ab. range, or ‘None’ if the bytecodes in
          the given range have no line number

     The items yielded will have the following properties:

        * The first range yielded will have a ‘start’ of 0.

        * The ‘(start, end)’ ranges will be non-decreasing and
          consecutive.  That is, for any pair of *note tuple: 614.s, the
          ‘start’ of the second will be equal to the ‘end’ of the first.

        * No range will be backwards: ‘end >= start’ for all triples.

        * The last *note tuple: 614. yielded will have ‘end’ equal to
          the size of the *note bytecode: 4ab.

     Zero-width ranges, where ‘start == end’, are allowed.  Zero-width
     ranges are used for lines that are present in the source code, but
     have been eliminated by the *note bytecode: 4ab. compiler.

     Added in version 3.10.

     Vedi anche
     ..........

     PEP 626(1) - Precise line numbers for debugging and other tools.

          The PEP that introduced the ‘co_lines()’ method.

 -- Metodo: codeobject.replace (**kwargs)

     Return a copy of the code object with new values for the specified
     fields.

     Code objects are also supported by the generic function *note
     copy.replace(): 1c0.

     Added in version 3.8.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0626/


File: python.info,  Node: Frame objects,  Next: Traceback objects,  Prev: Code objects,  Up: Internal types

4.3.2.40 Frame objects
......................

Frame objects represent execution frames.  They may occur in *note
traceback objects: cee, and are also passed to registered trace
functions.

* Menu:

* Special read-only attributes: Special read-only attributes<3>.
* Special writable attributes: Special writable attributes<2>.
* Frame object methods::


File: python.info,  Node: Special read-only attributes<3>,  Next: Special writable attributes<2>,  Up: Frame objects

4.3.2.41 Special read-only attributes
.....................................

 -- Attributo: frame.f_back                            Points to the previous stack frame (towards the
                                                       caller), or ‘None’ if this is the bottom stack frame
                                                       
                                                       
 -- Attributo: frame.f_code                            The *note code object: 4e7. being executed in this
                                                       frame.  Accessing this attribute raises an
                                                       *note auditing event: 1c56. ‘object.__getattr__’
                                                       with arguments ‘obj’ and ‘"f_code"’.
                                                       
                                                       
 -- Attributo: frame.f_locals                          The mapping used by the frame to look up
                                                       *note local variables: 232d.  If the frame refers to
                                                       an *note optimized scope: 4a2, this may return a
                                                       write-through proxy object.
                                                       
                                                       Cambiato nella versione 3.13: Return a proxy for
                                                       optimized scopes.
                                                       
                                                       
 -- Attributo: frame.f_globals                         The dictionary used by the frame to look up
                                                       *note global variables: 232d.
                                                       
                                                       
 -- Attributo: frame.f_builtins                        The dictionary used by the frame to look up
                                                       *note built-in (intrinsic) names: 232d.
                                                       
                                                       
 -- Attributo: frame.f_lasti                           The «precise instruction» of the frame object (this
                                                       is an index into the *note bytecode: 4ab. string of
                                                       the *note code object: 4e7.)
                                                       
                                                       
 -- Attributo: frame.f_generator                       The *note generator: 1263. or *note coroutine: 6ba.
                                                       object that owns this frame, or ‘None’ if the frame
                                                       is a normal function.
                                                       
                                                       Added in version 3.14.
                                                       


File: python.info,  Node: Special writable attributes<2>,  Next: Frame object methods,  Prev: Special read-only attributes<3>,  Up: Frame objects

4.3.2.42 Special writable attributes
....................................

 -- Attributo: frame.f_trace                           If not ‘None’, this is a function called for various
                                                       events during code execution (this is used by
                                                       debuggers).  Normally an event is triggered for each
                                                       new source line (see *note f_trace_lines: dd8.).
                                                       
                                                       
 -- Attributo: frame.f_trace_lines                     Set this attribute to *note False: d2d. to disable
                                                       triggering a tracing event for each source line.
                                                       
                                                       
 -- Attributo: frame.f_trace_opcodes                   Set this attribute to *note True: e09. to allow
                                                       per-opcode events to be requested.  Note that this
                                                       may lead to undefined interpreter behaviour if
                                                       exceptions raised by the trace function escape to
                                                       the function being traced.
                                                       
                                                       
 -- Attributo: frame.f_lineno                          The current line number of the frame – writing to
                                                       this from within a trace function jumps to the given
                                                       line (only for the bottom-most frame).  A debugger
                                                       can implement a Jump command (aka Set Next
                                                       Statement) by writing to this attribute.
                                                       


File: python.info,  Node: Frame object methods,  Prev: Special writable attributes<2>,  Up: Frame objects

4.3.2.43 Frame object methods
.............................

Frame objects support one method:

 -- Metodo: frame.clear ()

     This method clears all references to *note local variables: 232d.
     held by the frame.  Also, if the frame belonged to a *note
     generator: 1263, the generator is finalized.  This helps break
     reference cycles involving frame objects (for example when catching
     an *note exception: 1c0f. and storing its *note traceback: cee. for
     later use).

     *note RuntimeError: 244. is raised if the frame is currently
     executing or suspended.

     Added in version 3.4.

     Cambiato nella versione 3.13: Attempting to clear a suspended frame
     raises *note RuntimeError: 244. (as has always been the case for
     executing frames).


File: python.info,  Node: Traceback objects,  Next: Slice objects,  Prev: Frame objects,  Up: Internal types

4.3.2.44 Traceback objects
..........................

Traceback objects represent the stack trace of an *note exception: 205c.
A traceback object is implicitly created when an exception occurs, and
may also be explicitly created by calling *note types.TracebackType:
cec.

Cambiato nella versione 3.7: Traceback objects can now be explicitly
instantiated from Python code.

For implicitly created tracebacks, when the search for an exception
handler unwinds the execution stack, at each unwound level a traceback
object is inserted in front of the current traceback.  When an exception
handler is entered, the stack trace is made available to the program.
(See section *note The try statement: 8f9.)  It is accessible as the
third item of the tuple returned by *note sys.exc_info(): 89b, and as
the *note __traceback__: 14ce. attribute of the caught exception.

When the program contains no suitable handler, the stack trace is
written (nicely formatted) to the standard error stream; if the
interpreter is interactive, it is also made available to the user as
*note sys.last_traceback: 6e9.

For explicitly created tracebacks, it is up to the creator of the
traceback to determine how the *note tb_next: ced. attributes should be
linked to form a full stack trace.

Special read-only attributes:

 -- Attributo: traceback.tb_frame                      Points to the execution *note frame: 8f0. of the
                                                       current level.
                                                       
                                                       Accessing this attribute raises an
                                                       *note auditing event: 1c56. ‘object.__getattr__’
                                                       with arguments ‘obj’ and ‘"tb_frame"’.
                                                       
                                                       
 -- Attributo: traceback.tb_lineno                     Gives the line number where the exception occurred
                                                       
                                                       
 -- Attributo: traceback.tb_lasti                      Indicates the «precise instruction».
                                                       

The line number and last instruction in the traceback may differ from
the line number of its *note frame object: 8f0. if the exception
occurred in a *note try: 8f9. statement with no matching except clause
or with a *note finally: 1b0. clause.

 -- Attributo: traceback.tb_next

     The special writable attribute ‘tb_next’ is the next level in the
     stack trace (towards the frame where the exception occurred), or
     ‘None’ if there is no next level.

     Cambiato nella versione 3.7: This attribute is now writable


File: python.info,  Node: Slice objects,  Next: Static method objects,  Prev: Traceback objects,  Up: Internal types

4.3.2.45 Slice objects
......................

Slice objects are used to represent slices for *note __getitem__(): 588.
methods.  They are also created by the built-in *note slice(): 695.
function.

Special read-only attributes: *note start: 238b. is the lower bound;
*note stop: 238c. is the upper bound; *note step: 238d. is the step
value; each is ‘None’ if omitted.  These attributes can have any type.

Slice objects support one method:

 -- Metodo: slice.indices (self, length)

     This method takes a single integer argument 'length' and computes
     information about the slice that the slice object would describe if
     applied to a sequence of 'length' items.  It returns a tuple of
     three integers; respectively these are the 'start' and 'stop'
     indices and the 'step' or stride length of the slice.  Missing or
     out-of-bounds indices are handled in a manner consistent with
     regular slices.


File: python.info,  Node: Static method objects,  Next: Class method objects,  Prev: Slice objects,  Up: Internal types

4.3.2.46 Static method objects
..............................

Static method objects provide a way of defeating the transformation of
function objects to method objects described above.  A static method
object is a wrapper around any other object, usually a user-defined
method object.  When a static method object is retrieved from a class or
a class instance, the object actually returned is the wrapped object,
which is not subject to any further transformation.  Static method
objects are also callable.  Static method objects are created by the
built-in *note staticmethod(): 453. constructor.


File: python.info,  Node: Class method objects,  Prev: Static method objects,  Up: Internal types

4.3.2.47 Class method objects
.............................

A class method object, like a static method object, is a wrapper around
another object that alters the way in which that object is retrieved
from classes and class instances.  The behaviour of class method objects
upon such retrieval is described above, under *note «instance methods»:
2091.  Class method objects are created by the built-in *note
classmethod(): 48f. constructor.


File: python.info,  Node: Special method names,  Next: Coroutines,  Prev: The standard type hierarchy,  Up: Data model

4.3.3 Special method names
--------------------------

A class can implement certain operations that are invoked by special
syntax (such as arithmetic operations or subscripting and slicing) by
defining methods with special names.  This is Python’s approach to
'operator overloading', allowing classes to define their own behavior
with respect to language operators.  For instance, if a class defines a
method named *note __getitem__(): 588, and ‘x’ is an instance of this
class, then ‘x[i]’ is roughly equivalent to ‘type(x).__getitem__(x, i)’.
Except where mentioned, attempts to execute an operation raise an
exception when no appropriate method is defined (typically *note
AttributeError: 5f0. or *note TypeError: 198.).

Setting a special method to ‘None’ indicates that the corresponding
operation is not available.  For example, if a class sets *note
__iter__(): e6b. to ‘None’, the class is not iterable, so calling *note
iter(): 9d9. on its instances will raise a *note TypeError: 198.
(without falling back to *note __getitem__(): 588.).  (1)

When implementing a class that emulates any built-in type, it is
important that the emulation only be implemented to the degree that it
makes sense for the object being modelled.  For example, some sequences
may work well with retrieval of individual elements, but extracting a
slice may not make sense.  (One example of this is the *note NodeList:
2391. interface in the W3C’s Document Object Model.)

* Menu:

* Basic customization::
* Customizing attribute access::
* Customizing class creation::
* Customizing instance and subclass checks::
* Emulating generic types::
* Emulating callable objects::
* Emulating container types::
* Emulating numeric types::
* With Statement Context Managers::
* Customizing positional arguments in class pattern matching::
* Emulating buffer types::
* Annotations::
* Special method lookup::

   ---------- Footnotes ----------

   (1) The *note __hash__(): cf5, *note __iter__(): e6b, *note
__reversed__(): e88, *note __contains__(): 15c1, *note
__class_getitem__(): 944. and *note __fspath__(): e4e. methods have
special handling for this.  Others will still raise a *note TypeError:
198, but may do so by relying on the behavior that ‘None’ is not
callable.


File: python.info,  Node: Basic customization,  Next: Customizing attribute access,  Up: Special method names

4.3.3.1 Basic customization
...........................

 -- Metodo: object.__new__ (cls[, ...])

     Called to create a new instance of class 'cls'.  *note __new__():
     7a1. is a static method (special-cased so you need not declare it
     as such) that takes the class of which an instance was requested as
     its first argument.  The remaining arguments are those passed to
     the object constructor expression (the call to the class).  The
     return value of *note __new__(): 7a1. should be the new object
     instance (usually an instance of 'cls').

     Typical implementations create a new instance of the class by
     invoking the superclass’s *note __new__(): 7a1. method using
     ‘super().__new__(cls[, ...])’ with appropriate arguments and then
     modifying the newly created instance as necessary before returning
     it.

     If *note __new__(): 7a1. is invoked during object construction and
     it returns an instance of 'cls', then the new instance’s *note
     __init__(): 8c0. method will be invoked like ‘__init__(self[,
     ...])’, where 'self' is the new instance and the remaining
     arguments are the same as were passed to the object constructor.

     If *note __new__(): 7a1. does not return an instance of 'cls', then
     the new instance’s *note __init__(): 8c0. method will not be
     invoked.

     *note __new__(): 7a1. is intended mainly to allow subclasses of
     immutable types (like int, str, or tuple) to customize instance
     creation.  It is also commonly overridden in custom metaclasses in
     order to customize class creation.

 -- Metodo: object.__init__ (self[, ...])

     Called after the instance has been created (by *note __new__():
     7a1.), but before it is returned to the caller.  The arguments are
     those passed to the class constructor expression.  If a base class
     has an *note __init__(): 8c0. method, the derived class’s *note
     __init__(): 8c0. method, if any, must explicitly call it to ensure
     proper initialization of the base class part of the instance; for
     example: ‘super().__init__([args...])’.

     Because *note __new__(): 7a1. and *note __init__(): 8c0. work
     together in constructing objects (*note __new__(): 7a1. to create
     it, and *note __init__(): 8c0. to customize it), no non-‘None’
     value may be returned by *note __init__(): 8c0.; doing so will
     cause a *note TypeError: 198. to be raised at runtime.

 -- Metodo: object.__del__ (self)

     Called when the instance is about to be destroyed.  This is also
     called a finalizer or (improperly) a destructor.  If a base class
     has a *note __del__(): 11ff. method, the derived class’s *note
     __del__(): 11ff. method, if any, must explicitly call it to ensure
     proper deletion of the base class part of the instance.

     It is possible (though not recommended!)  for the *note __del__():
     11ff. method to postpone destruction of the instance by creating a
     new reference to it.  This is called object 'resurrection'.  It is
     implementation-dependent whether *note __del__(): 11ff. is called a
     second time when a resurrected object is about to be destroyed; the
     current *note CPython: 906. implementation only calls it once.

     It is not guaranteed that *note __del__(): 11ff. methods are called
     for objects that still exist when the interpreter exits.  *note
     weakref.finalize: c71. provides a straightforward way to register a
     cleanup function to be called when an object is garbage collected.

          Nota: ‘del x’ doesn’t directly call ‘x.__del__()’ — the former
          decrements the reference count for ‘x’ by one, and the latter
          is only called when ‘x’’s reference count reaches zero.

     'Dettaglio dell’implementazione di CPython:' It is possible for a
     reference cycle to prevent the reference count of an object from
     going to zero.  In this case, the cycle will be later detected and
     deleted by the *note cyclic garbage collector: 17c0.  A common
     cause of reference cycles is when an exception has been caught in a
     local variable.  The frame’s locals then reference the exception,
     which references its own traceback, which references the locals of
     all frames caught in the traceback.

     Vedi anche
     ..........

     Documentation for the *note gc: 64. module.

          Avvertimento: Due to the precarious circumstances under which
          *note __del__(): 11ff. methods are invoked, exceptions that
          occur during their execution are ignored, and a warning is
          printed to ‘sys.stderr’ instead.  In particular:

             * *note __del__(): 11ff. can be invoked when arbitrary code
               is being executed, including from any arbitrary thread.
               If *note __del__(): 11ff. needs to take a lock or invoke
               any other blocking resource, it may deadlock as the
               resource may already be taken by the code that gets
               interrupted to execute *note __del__(): 11ff.

             * *note __del__(): 11ff. can be executed during interpreter
               shutdown.  As a consequence, the global variables it
               needs to access (including other modules) may already
               have been deleted or set to ‘None’.  Python guarantees
               that globals whose name begins with a single underscore
               are deleted from their module before other globals are
               deleted; if no other references to such globals exist,
               this may help in assuring that imported modules are still
               available at the time when the *note __del__(): 11ff.
               method is called.

 -- Metodo: object.__repr__ (self)

     Called by the *note repr(): 1c1. built-in function to compute the
     «official» string representation of an object.  If at all possible,
     this should look like a valid Python expression that could be used
     to recreate an object with the same value (given an appropriate
     environment).  If this is not possible, a string of the form
     ‘<...some useful description...>’ should be returned.  The return
     value must be a string object.  If a class defines *note
     __repr__(): 830. but not *note __str__(): 831, then *note
     __repr__(): 830. is also used when an «informal» string
     representation of instances of that class is required.

     This is typically used for debugging, so it is important that the
     representation is information-rich and unambiguous.  A default
     implementation is provided by the *note object: c80. class itself.

 -- Metodo: object.__str__ (self)

     Called by *note str(object): 169, the default *note __format__():
     832. implementation, and the built-in function *note print(): 1177,
     to compute the «informal» or nicely printable string representation
     of an object.  The return value must be a *note str: 1fc9. object.

     This method differs from *note object.__repr__(): 830. in that
     there is no expectation that *note __str__(): 831. return a valid
     Python expression: a more convenient or concise representation can
     be used.

     The default implementation defined by the built-in type *note
     object: c80. calls *note object.__repr__(): 830.

 -- Metodo: object.__bytes__ (self)

     Called by *note bytes: 1e82. to compute a byte-string
     representation of an object.  This should return a *note bytes:
     192. object.  The *note object: c80. class itself does not provide
     this method.

 -- Metodo: object.__format__ (self, format_spec)

     Called by the *note format(): 199. built-in function, and by
     extension, evaluation of *note formatted string literals: 19a. and
     the *note str.format(): 834. method, to produce a «formatted»
     string representation of an object.  The 'format_spec' argument is
     a string that contains a description of the formatting options
     desired.  The interpretation of the 'format_spec' argument is up to
     the type implementing *note __format__(): 832, however most classes
     will either delegate formatting to one of the built-in types, or
     use a similar formatting option syntax.

     See *note Format Specification Mini-Language: 4fa. for a
     description of the standard formatting syntax.

     The return value must be a string object.

     The default implementation by the *note object: c80. class should
     be given an empty 'format_spec' string.  It delegates to *note
     __str__(): 831.

     Cambiato nella versione 3.4: The __format__ method of ‘object’
     itself raises a *note TypeError: 198. if passed any non-empty
     string.

     Cambiato nella versione 3.7: ‘object.__format__(x, '')’ is now
     equivalent to ‘str(x)’ rather than ‘format(str(x), '')’.

 -- Metodo: object.__lt__ (self, other)
 -- Metodo: object.__le__ (self, other)
 -- Metodo: object.__eq__ (self, other)
 -- Metodo: object.__ne__ (self, other)
 -- Metodo: object.__gt__ (self, other)
 -- Metodo: object.__ge__ (self, other)

     These are the so-called «rich comparison» methods.  The
     correspondence between operator symbols and method names is as
     follows: ‘x<y’ calls ‘x.__lt__(y)’, ‘x<=y’ calls ‘x.__le__(y)’,
     ‘x==y’ calls ‘x.__eq__(y)’, ‘x!=y’ calls ‘x.__ne__(y)’, ‘x>y’ calls
     ‘x.__gt__(y)’, and ‘x>=y’ calls ‘x.__ge__(y)’.

     A rich comparison method may return the singleton *note
     NotImplemented: 1a2. if it does not implement the operation for a
     given pair of arguments.  By convention, ‘False’ and ‘True’ are
     returned for a successful comparison.  However, these methods can
     return any value, so if the comparison operator is used in a
     Boolean context (e.g., in the condition of an ‘if’ statement),
     Python will call *note bool(): 3c3. on the value to determine if
     the result is true or false.

     By default, ‘object’ implements *note __eq__(): cf4. by using ‘is’,
     returning *note NotImplemented: 1a2. in the case of a false
     comparison: ‘True if x is y else NotImplemented’.  For *note
     __ne__(): 171e, by default it delegates to *note __eq__(): cf4. and
     inverts the result unless it is ‘NotImplemented’.  There are no
     other implied relationships among the comparison operators or
     default implementations; for example, the truth of ‘(x<y or x==y)’
     does not imply ‘x<=y’.  To automatically generate ordering
     operations from a single root operation, see *note
     functools.total_ordering(): 1144.

     By default, the *note object: c80. class provides implementations
     consistent with *note Value comparisons: 1c08.: equality compares
     according to object identity, and order comparisons raise *note
     TypeError: 198.  Each default method may generate these results
     directly, but may also return *note NotImplemented: 1a2.

     See the paragraph on *note __hash__(): cf5. for some important
     notes on creating *note hashable: 825. objects which support custom
     comparison operations and are usable as dictionary keys.

     There are no swapped-argument versions of these methods (to be used
     when the left argument does not support the operation but the right
     argument does); rather, *note __lt__(): 14a8. and *note __gt__():
     1513. are each other’s reflection, *note __le__(): 1512. and *note
     __ge__(): 1514. are each other’s reflection, and *note __eq__():
     cf4. and *note __ne__(): 171e. are their own reflection.  If the
     operands are of different types, and the right operand’s type is a
     direct or indirect subclass of the left operand’s type, the
     reflected method of the right operand has priority, otherwise the
     left operand’s method has priority.  Virtual subclassing is not
     considered.

     When no appropriate method returns any value other than *note
     NotImplemented: 1a2, the ‘==’ and ‘!=’ operators will fall back to
     ‘is’ and ‘is not’, respectively.

 -- Metodo: object.__hash__ (self)

     Called by built-in function *note hash(): 802. and for operations
     on members of hashed collections including *note set: 184, *note
     frozenset: 7f3, and *note dict: 183.  The ‘__hash__()’ method
     should return an integer.  The only required property is that
     objects which compare equal have the same hash value; it is advised
     to mix together the hash values of the components of the object
     that also play a part in comparison of objects by packing them into
     a tuple and hashing the tuple.  Example:

          def __hash__(self):
              return hash((self.name, self.nick, self.color))

          Nota: *note hash(): 802. truncates the value returned from an
          object’s custom *note __hash__(): cf5. method to the size of a
          *note Py_ssize_t: c57.  This is typically 8 bytes on 64-bit
          builds and 4 bytes on 32-bit builds.  If an object’s *note
          __hash__(): cf5. must interoperate on builds of different bit
          sizes, be sure to check the width on all supported builds.  An
          easy way to do this is with ‘python -c "import sys;
          print(sys.hash_info.width)"’.

     If a class does not define an *note __eq__(): cf4. method it should
     not define a *note __hash__(): cf5. operation either; if it defines
     *note __eq__(): cf4. but not *note __hash__(): cf5, its instances
     will not be usable as items in hashable collections.  If a class
     defines mutable objects and implements an *note __eq__(): cf4.
     method, it should not implement *note __hash__(): cf5, since the
     implementation of *note hashable: 825. collections requires that a
     key’s hash value is immutable (if the object’s hash value changes,
     it will be in the wrong hash bucket).

     User-defined classes have *note __eq__(): cf4. and *note
     __hash__(): cf5. methods by default (inherited from the *note
     object: c80. class); with them, all objects compare unequal (except
     with themselves) and ‘x.__hash__()’ returns an appropriate value
     such that ‘x == y’ implies both that ‘x is y’ and ‘hash(x) ==
     hash(y)’.

     A class that overrides *note __eq__(): cf4. and does not define
     *note __hash__(): cf5. will have its *note __hash__(): cf5.
     implicitly set to ‘None’.  When the *note __hash__(): cf5. method
     of a class is ‘None’, instances of the class will raise an
     appropriate *note TypeError: 198. when a program attempts to
     retrieve their hash value, and will also be correctly identified as
     unhashable when checking ‘isinstance(obj,
     collections.abc.Hashable)’.

     If a class that overrides *note __eq__(): cf4. needs to retain the
     implementation of *note __hash__(): cf5. from a parent class, the
     interpreter must be told this explicitly by setting ‘__hash__ =
     <ParentClass>.__hash__’.

     If a class that does not override *note __eq__(): cf4. wishes to
     suppress hash support, it should include ‘__hash__ = None’ in the
     class definition.  A class which defines its own *note __hash__():
     cf5. that explicitly raises a *note TypeError: 198. would be
     incorrectly identified as hashable by an ‘isinstance(obj,
     collections.abc.Hashable)’ call.

          Nota: By default, the *note __hash__(): cf5. values of str and
          bytes objects are «salted» with an unpredictable random value.
          Although they remain constant within an individual Python
          process, they are not predictable between repeated invocations
          of Python.

          This is intended to provide protection against a
          denial-of-service caused by carefully chosen inputs that
          exploit the worst case performance of a dict insertion,
          'O'('n'^2) complexity.  See
          ‘http://ocert.org/advisories/ocert-2011-003.html’ for details.

          Changing hash values affects the iteration order of sets.
          Python has never made guarantees about this ordering (and it
          typically varies between 32-bit and 64-bit builds).

          See also *note PYTHONHASHSEED: 127f.

     Cambiato nella versione 3.3: Hash randomization is enabled by
     default.

 -- Metodo: object.__bool__ (self)

     Called to implement truth value testing and the built-in operation
     ‘bool()’; should return ‘False’ or ‘True’.  When this method is not
     defined, *note __len__(): 1777. is called, if it is defined, and
     the object is considered true if its result is nonzero.  If a class
     defines neither ‘__len__()’ nor ‘__bool__()’ (which is true of the
     *note object: c80. class itself), all its instances are considered
     true.


File: python.info,  Node: Customizing attribute access,  Next: Customizing class creation,  Prev: Basic customization,  Up: Special method names

4.3.3.2 Customizing attribute access
....................................

The following methods can be defined to customize the meaning of
attribute access (use of, assignment to, or deletion of ‘x.name’) for
class instances.

 -- Metodo: object.__getattr__ (self, name)

     Called when the default attribute access fails with an *note
     AttributeError: 5f0. (either *note __getattribute__(): dcd. raises
     an *note AttributeError: 5f0. because 'name' is not an instance
     attribute or an attribute in the class tree for ‘self’; or *note
     __get__(): 16ef. of a 'name' property raises *note AttributeError:
     5f0.).  This method should either return the (computed) attribute
     value or raise an *note AttributeError: 5f0. exception.  The *note
     object: c80. class itself does not provide this method.

     Note that if the attribute is found through the normal mechanism,
     *note __getattr__(): 6fb. is not called.  (This is an intentional
     asymmetry between *note __getattr__(): 6fb. and *note
     __setattr__(): 2362.)  This is done both for efficiency reasons and
     because otherwise *note __getattr__(): 6fb. would have no way to
     access other attributes of the instance.  Note that at least for
     instance variables, you can take total control by not inserting any
     values in the instance attribute dictionary (but instead inserting
     them in another object).  See the *note __getattribute__(): dcd.
     method below for a way to actually get total control over attribute
     access.

 -- Metodo: object.__getattribute__ (self, name)

     Called unconditionally to implement attribute accesses for
     instances of the class.  If the class also defines *note
     __getattr__(): 6fb, the latter will not be called unless *note
     __getattribute__(): dcd. either calls it explicitly or raises an
     *note AttributeError: 5f0.  This method should return the
     (computed) attribute value or raise an *note AttributeError: 5f0.
     exception.  In order to avoid infinite recursion in this method,
     its implementation should always call the base class method with
     the same name to access any attributes it needs, for example,
     ‘object.__getattribute__(self, name)’.

          Nota: This method may still be bypassed when looking up
          special methods as the result of implicit invocation via
          language syntax or *note built-in functions: 2335.  See *note
          Special method lookup: 2397.

     For certain sensitive attribute accesses, raises an *note auditing
     event: 1c56. ‘object.__getattr__’ with arguments ‘obj’ and ‘name’.

 -- Metodo: object.__setattr__ (self, name, value)

     Called when an attribute assignment is attempted.  This is called
     instead of the normal mechanism (i.e.  store the value in the
     instance dictionary).  'name' is the attribute name, 'value' is the
     value to be assigned to it.

     If *note __setattr__(): 2362. wants to assign to an instance
     attribute, it should call the base class method with the same name,
     for example, ‘object.__setattr__(self, name, value)’.

     For certain sensitive attribute assignments, raises an *note
     auditing event: 1c56. ‘object.__setattr__’ with arguments ‘obj’,
     ‘name’, ‘value’.

 -- Metodo: object.__delattr__ (self, name)

     Like *note __setattr__(): 2362. but for attribute deletion instead
     of assignment.  This should only be implemented if ‘del obj.name’
     is meaningful for the object.

     For certain sensitive attribute deletions, raises an *note auditing
     event: 1c56. ‘object.__delattr__’ with arguments ‘obj’ and ‘name’.

 -- Metodo: object.__dir__ (self)

     Called when *note dir(): 845. is called on the object.  An iterable
     must be returned.  *note dir(): 845. converts the returned iterable
     to a list and sorts it.

* Menu:

* Customizing module attribute access::
* Implementing Descriptors::
* Invoking Descriptors::
* __slots__: __slots__<2>.


File: python.info,  Node: Customizing module attribute access,  Next: Implementing Descriptors,  Up: Customizing attribute access

4.3.3.3 Customizing module attribute access
...........................................

 -- Metodo: module.__getattr__ ()
 -- Metodo: module.__dir__ ()

Special names ‘__getattr__’ and ‘__dir__’ can be also used to customize
access to module attributes.  The ‘__getattr__’ function at the module
level should accept one argument which is the name of an attribute and
return the computed value or raise an *note AttributeError: 5f0.  If an
attribute is not found on a module object through the normal lookup,
i.e.  *note object.__getattribute__(): dcd, then ‘__getattr__’ is
searched in the module ‘__dict__’ before raising an *note
AttributeError: 5f0.  If found, it is called with the attribute name and
the result is returned.

The ‘__dir__’ function should accept no arguments, and return an
iterable of strings that represents the names accessible on module.  If
present, this function overrides the standard *note dir(): 845. search
on a module.

 -- Attributo: module.__class__

For a more fine grained customization of the module behavior (setting
attributes, properties, etc.), one can set the ‘__class__’ attribute of
a module object to a subclass of *note types.ModuleType: 1016.  For
example:

     import sys
     from types import ModuleType

     class VerboseModule(ModuleType):
         def __repr__(self):
             return f'Verbose {self.__name__}'

         def __setattr__(self, attr, value):
             print(f'Setting {attr}...')
             super().__setattr__(attr, value)

     sys.modules[__name__].__class__ = VerboseModule

     Nota: Defining module ‘__getattr__’ and setting module ‘__class__’
     only affect lookups made using the attribute access syntax –
     directly accessing the module globals (whether by code within the
     module, or via a reference to the module’s globals dictionary) is
     unaffected.

Cambiato nella versione 3.5: ‘__class__’ module attribute is now
writable.

Added in version 3.7: ‘__getattr__’ and ‘__dir__’ module attributes.

Vedi anche
..........

PEP 562(1) - Module __getattr__ and __dir__

     Describes the ‘__getattr__’ and ‘__dir__’ functions on modules.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0562/


File: python.info,  Node: Implementing Descriptors,  Next: Invoking Descriptors,  Prev: Customizing module attribute access,  Up: Customizing attribute access

4.3.3.4 Implementing Descriptors
................................

The following methods only apply when an instance of the class
containing the method (a so-called 'descriptor' class) appears in an
'owner' class (the descriptor must be in either the owner’s class
dictionary or in the class dictionary for one of its parents).  In the
examples below, «the attribute» refers to the attribute whose name is
the key of the property in the owner class” *note __dict__: 77e.  The
*note object: c80. class itself does not implement any of these
protocols.

 -- Metodo: object.__get__ (self, instance, owner=None)

     Called to get the attribute of the owner class (class attribute
     access) or of an instance of that class (instance attribute
     access).  The optional 'owner' argument is the owner class, while
     'instance' is the instance that the attribute was accessed through,
     or ‘None’ when the attribute is accessed through the 'owner'.

     This method should return the computed attribute value or raise an
     *note AttributeError: 5f0. exception.

     PEP 252(1) specifies that *note __get__(): 16ef. is callable with
     one or two arguments.  Python’s own built-in descriptors support
     this specification; however, it is likely that some third-party
     tools have descriptors that require both arguments.  Python’s own
     *note __getattribute__(): dcd. implementation always passes in both
     arguments whether they are required or not.

 -- Metodo: object.__set__ (self, instance, value)

     Called to set the attribute on an instance 'instance' of the owner
     class to a new value, 'value'.

     Note, adding *note __set__(): 239b. or *note __delete__(): 1937.
     changes the kind of descriptor to a «data descriptor».  See *note
     Invoking Descriptors: 239c. for more details.

 -- Metodo: object.__delete__ (self, instance)

     Called to delete the attribute on an instance 'instance' of the
     owner class.

Instances of descriptors may also have the ‘__objclass__’ attribute
present:

 -- Attributo: object.__objclass__

     The attribute ‘__objclass__’ is interpreted by the *note inspect:
     82. module as specifying the class where this object was defined
     (setting this appropriately can assist in runtime introspection of
     dynamic class attributes).  For callables, it may indicate that an
     instance of the given type (or a subclass) is expected or required
     as the first positional argument (for example, CPython sets this
     attribute for unbound methods that are implemented in C).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0252/


File: python.info,  Node: Invoking Descriptors,  Next: __slots__<2>,  Prev: Implementing Descriptors,  Up: Customizing attribute access

4.3.3.5 Invoking Descriptors
............................

In general, a descriptor is an object attribute with «binding behavior»,
one whose attribute access has been overridden by methods in the
descriptor protocol: *note __get__(): 16ef, *note __set__(): 239b, and
*note __delete__(): 1937.  If any of those methods are defined for an
object, it is said to be a descriptor.

The default behavior for attribute access is to get, set, or delete the
attribute from an object’s dictionary.  For instance, ‘a.x’ has a lookup
chain starting with ‘a.__dict__['x']’, then ‘type(a).__dict__['x']’, and
continuing through the base classes of ‘type(a)’ excluding metaclasses.

However, if the looked-up value is an object defining one of the
descriptor methods, then Python may override the default behavior and
invoke the descriptor method instead.  Where this occurs in the
precedence chain depends on which descriptor methods were defined and
how they were called.

The starting point for descriptor invocation is a binding, ‘a.x’.  How
the arguments are assembled depends on ‘a’:

Direct Call

     The simplest and least common call is when user code directly
     invokes a descriptor method: ‘x.__get__(a)’.

Instance Binding

     If binding to an object instance, ‘a.x’ is transformed into the
     call: ‘type(a).__dict__['x'].__get__(a, type(a))’.

Class Binding

     If binding to a class, ‘A.x’ is transformed into the call:
     ‘A.__dict__['x'].__get__(None, A)’.

Super Binding

     A dotted lookup such as ‘super(A, a).x’ searches
     ‘a.__class__.__mro__’ for a base class ‘B’ following ‘A’ and then
     returns ‘B.__dict__['x'].__get__(a, A)’.  If not a descriptor, ‘x’
     is returned unchanged.

For instance bindings, the precedence of descriptor invocation depends
on which descriptor methods are defined.  A descriptor can define any
combination of *note __get__(): 16ef, *note __set__(): 239b. and *note
__delete__(): 1937.  If it does not define ‘__get__()’, then accessing
the attribute will return the descriptor object itself unless there is a
value in the object’s instance dictionary.  If the descriptor defines
‘__set__()’ and/or ‘__delete__()’, it is a data descriptor; if it
defines neither, it is a non-data descriptor.  Normally, data
descriptors define both ‘__get__()’ and ‘__set__()’, while non-data
descriptors have just the ‘__get__()’ method.  Data descriptors with
‘__get__()’ and ‘__set__()’ (and/or ‘__delete__()’) defined always
override a redefinition in an instance dictionary.  In contrast,
non-data descriptors can be overridden by instances.

Python methods (including those decorated with *note @staticmethod: 453.
and *note @classmethod: 48f.) are implemented as non-data descriptors.
Accordingly, instances can redefine and override methods.  This allows
individual instances to acquire behaviors that differ from other
instances of the same class.

The *note property(): 4b4. function is implemented as a data descriptor.
Accordingly, instances cannot override the behavior of a property.


File: python.info,  Node: __slots__<2>,  Prev: Invoking Descriptors,  Up: Customizing attribute access

4.3.3.6 __slots__
.................

'__slots__' allow us to explicitly declare data members (like
properties) and deny the creation of *note __dict__: 77e. and
'__weakref__' (unless explicitly declared in '__slots__' or available in
a parent.)

The space saved over using *note __dict__: 77e. can be significant.
Attribute lookup speed can be significantly improved as well.

 -- Dati: object.__slots__

     This class variable can be assigned a string, iterable, or sequence
     of strings with variable names used by instances.  '__slots__'
     reserves space for the declared variables and prevents the
     automatic creation of *note __dict__: 77e. and '__weakref__' for
     each instance.
Notes on using '__slots__':

   * When inheriting from a class without '__slots__', the *note
     __dict__: 77e. and '__weakref__' attribute of the instances will
     always be accessible.

   * Without a *note __dict__: 77e. variable, instances cannot be
     assigned new variables not listed in the '__slots__' definition.
     Attempts to assign to an unlisted variable name raises *note
     AttributeError: 5f0.  If dynamic assignment of new variables is
     desired, then add ‘'__dict__'’ to the sequence of strings in the
     '__slots__' declaration.

   * Without a '__weakref__' variable for each instance, classes
     defining '__slots__' do not support *note weak references: 11a. to
     its instances.  If weak reference support is needed, then add
     ‘'__weakref__'’ to the sequence of strings in the '__slots__'
     declaration.

   * '__slots__' are implemented at the class level by creating *note
     descriptors: e4b. for each variable name.  As a result, class
     attributes cannot be used to set default values for instance
     variables defined by '__slots__'; otherwise, the class attribute
     would overwrite the descriptor assignment.

   * The action of a '__slots__' declaration is not limited to the class
     where it is defined.  '__slots__' declared in parents are available
     in child classes.  However, instances of a child subclass will get
     a *note __dict__: 77e. and '__weakref__' unless the subclass also
     defines '__slots__' (which should only contain names of any
     'additional' slots).

   * If a class defines a slot also defined in a base class, the
     instance variable defined by the base class slot is inaccessible
     (except by retrieving its descriptor directly from the base class).
     This renders the meaning of the program undefined.  In the future,
     a check may be added to prevent this.

   * *note TypeError: 198. will be raised if nonempty '__slots__' are
     defined for a class derived from a *note "variable-length" built-in
     type: 23a1. such as *note int: 19b, *note bytes: 192, and *note
     tuple: 614.

   * Any non-string *note iterable: 142f. may be assigned to
     '__slots__'.

   * If a *note dictionary: 183. is used to assign '__slots__', the
     dictionary keys will be used as the slot names.  The values of the
     dictionary can be used to provide per-attribute docstrings that
     will be recognised by *note inspect.getdoc(): bef. and displayed in
     the output of *note help(): ad6.

   * *note __class__: 16b4. assignment works only if both classes have
     the same '__slots__'.

   * *note Multiple inheritance: 208b. with multiple slotted parent
     classes can be used, but only one parent is allowed to have
     attributes created by slots (the other bases must have empty slot
     layouts) - violations raise *note TypeError: 198.

   * If an *note iterator: 4c9. is used for '__slots__' then a *note
     descriptor: 1869. is created for each of the iterator’s values.
     However, the '__slots__' attribute will be an empty iterator.


File: python.info,  Node: Customizing class creation,  Next: Customizing instance and subclass checks,  Prev: Customizing attribute access,  Up: Special method names

4.3.3.7 Customizing class creation
..................................

Whenever a class inherits from another class, *note __init_subclass__():
844. is called on the parent class.  This way, it is possible to write
classes which change the behavior of subclasses.  This is closely
related to class decorators, but where class decorators only affect the
specific class they’re applied to, ‘__init_subclass__’ solely applies to
future subclasses of the class defining the method.

 -- Metodo: classmethod object.__init_subclass__ (cls)

     This method is called whenever the containing class is subclassed.
     'cls' is then the new subclass.  If defined as a normal instance
     method, this method is implicitly converted to a class method.

     Keyword arguments which are given to a new class are passed to the
     parent class’s ‘__init_subclass__’.  For compatibility with other
     classes using ‘__init_subclass__’, one should take out the needed
     keyword arguments and pass the others over to the base class, as
     in:

          class Philosopher:
              def __init_subclass__(cls, /, default_name, **kwargs):
                  super().__init_subclass__(**kwargs)
                  cls.default_name = default_name

          class AustralianPhilosopher(Philosopher, default_name="Bruce"):
              pass

     The default implementation ‘object.__init_subclass__’ does nothing,
     but raises an error if it is called with any arguments.

          Nota: The metaclass hint ‘metaclass’ is consumed by the rest
          of the type machinery, and is never passed to
          ‘__init_subclass__’ implementations.  The actual metaclass
          (rather than the explicit hint) can be accessed as
          ‘type(cls)’.

     Added in version 3.6.

When a class is created, ‘type.__new__()’ scans the class variables and
makes callbacks to those with a *note __set_name__(): e4a. hook.

 -- Metodo: object.__set_name__ (self, owner, name)

     Automatically called at the time the owning class 'owner' is
     created.  The object has been assigned to 'name' in that class:

          class A:
              x = C()  # Automatically calls: x.__set_name__(A, 'x')

     If the class variable is assigned after the class is created, *note
     __set_name__(): e4a. will not be called automatically.  If needed,
     *note __set_name__(): e4a. can be called directly:

          class A:
             pass

          c = C()
          A.x = c                  # The hook is not called
          c.__set_name__(A, 'x')   # Manually invoke the hook

     See *note Creating the class object: e46. for more details.

     Added in version 3.6.

* Menu:

* Metaclasses::
* Resolving MRO entries::
* Determining the appropriate metaclass::
* Preparing the class namespace::
* Executing the class body::
* Creating the class object::
* Uses for metaclasses::


File: python.info,  Node: Metaclasses,  Next: Resolving MRO entries,  Up: Customizing class creation

4.3.3.8 Metaclasses
...................

By default, classes are constructed using *note type(): f46.  The class
body is executed in a new namespace and the class name is bound locally
to the result of ‘type(name, bases, namespace)’.

The class creation process can be customized by passing the ‘metaclass’
keyword argument in the class definition line, or by inheriting from an
existing class that included such an argument.  In the following
example, both ‘MyClass’ and ‘MySubclass’ are instances of ‘Meta’:

     class Meta(type):
         pass

     class MyClass(metaclass=Meta):
         pass

     class MySubclass(MyClass):
         pass

Any other keyword arguments that are specified in the class definition
are passed through to all metaclass operations described below.

When a class definition is executed, the following steps occur:

   * MRO entries are resolved;

   * the appropriate metaclass is determined;

   * the class namespace is prepared;

   * the class body is executed;

   * the class object is created.


File: python.info,  Node: Resolving MRO entries,  Next: Determining the appropriate metaclass,  Prev: Metaclasses,  Up: Customizing class creation

4.3.3.9 Resolving MRO entries
.............................

 -- Metodo: object.__mro_entries__ (self, bases)

     If a base that appears in a class definition is not an instance of
     *note type: f46, then an ‘__mro_entries__()’ method is searched on
     the base.  If an ‘__mro_entries__()’ method is found, the base is
     substituted with the result of a call to ‘__mro_entries__()’ when
     creating the class.  The method is called with the original bases
     tuple passed to the 'bases' parameter, and must return a tuple of
     classes that will be used instead of the base.  The returned tuple
     may be empty: in these cases, the original base is ignored.

Vedi anche
..........

*note types.resolve_bases(): d97.

     Dynamically resolve bases that are not instances of *note type:
     f46.

*note types.get_original_bases(): 6f6.

     Retrieve a class’s «original bases» prior to modifications by *note
     __mro_entries__(): ce5.

PEP 560(1)

     Core support for typing module and generic types.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0560/


File: python.info,  Node: Determining the appropriate metaclass,  Next: Preparing the class namespace,  Prev: Resolving MRO entries,  Up: Customizing class creation

4.3.3.10 Determining the appropriate metaclass
..............................................

The appropriate metaclass for a class definition is determined as
follows:

   * if no bases and no explicit metaclass are given, then *note type():
     f46. is used;

   * if an explicit metaclass is given and it is 'not' an instance of
     *note type(): f46, then it is used directly as the metaclass;

   * if an instance of *note type(): f46. is given as the explicit
     metaclass, or bases are defined, then the most derived metaclass is
     used.

The most derived metaclass is selected from the explicitly specified
metaclass (if any) and the metaclasses (i.e.  ‘type(cls)’) of all
specified base classes.  The most derived metaclass is one which is a
subtype of 'all' of these candidate metaclasses.  If none of the
candidate metaclasses meets that criterion, then the class definition
will fail with ‘TypeError’.


File: python.info,  Node: Preparing the class namespace,  Next: Executing the class body,  Prev: Determining the appropriate metaclass,  Up: Customizing class creation

4.3.3.11 Preparing the class namespace
......................................

Once the appropriate metaclass has been identified, then the class
namespace is prepared.  If the metaclass has a ‘__prepare__’ attribute,
it is called as ‘namespace = metaclass.__prepare__(name, bases, **kwds)’
(where the additional keyword arguments, if any, come from the class
definition).  The ‘__prepare__’ method should be implemented as a *note
classmethod: 48f.  The namespace returned by ‘__prepare__’ is passed in
to ‘__new__’, but when the final class object is created the namespace
is copied into a new ‘dict’.

If the metaclass has no ‘__prepare__’ attribute, then the class
namespace is initialised as an empty ordered mapping.

Vedi anche
..........

PEP 3115(1) - Metaclasses in Python 3000

     Introduced the ‘__prepare__’ namespace hook

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3115/


File: python.info,  Node: Executing the class body,  Next: Creating the class object,  Prev: Preparing the class namespace,  Up: Customizing class creation

4.3.3.12 Executing the class body
.................................

The class body is executed (approximately) as ‘exec(body, globals(),
namespace)’.  The key difference from a normal call to *note exec():
4a3. is that lexical scoping allows the class body (including any
methods) to reference names from the current and outer scopes when the
class definition occurs inside a function.

However, even when the class definition occurs inside the function,
methods defined inside the class still cannot see names defined at the
class scope.  Class variables must be accessed through the first
parameter of instance or class methods, or through the implicit
lexically scoped ‘__class__’ reference described in the next section.


File: python.info,  Node: Creating the class object,  Next: Uses for metaclasses,  Prev: Executing the class body,  Up: Customizing class creation

4.3.3.13 Creating the class object
..................................

Once the class namespace has been populated by executing the class body,
the class object is created by calling ‘metaclass(name, bases,
namespace, **kwds)’ (the additional keywords passed here are the same as
those passed to ‘__prepare__’).

This class object is the one that will be referenced by the
zero-argument form of *note super(): 1a6.  ‘__class__’ is an implicit
closure reference created by the compiler if any methods in a class body
refer to either ‘__class__’ or ‘super’.  This allows the zero argument
form of *note super(): 1a6. to correctly identify the class being
defined based on lexical scoping, while the class or instance that was
used to make the current call is identified based on the first argument
passed to the method.

'Dettaglio dell’implementazione di CPython:' In CPython 3.6 and later,
the ‘__class__’ cell is passed to the metaclass as a ‘__classcell__’
entry in the class namespace.  If present, this must be propagated up to
the ‘type.__new__’ call in order for the class to be initialised
correctly.  Failing to do so will result in a *note RuntimeError: 244.
in Python 3.8.

When using the default metaclass *note type: f46, or any metaclass that
ultimately calls ‘type.__new__’, the following additional customization
steps are invoked after creating the class object:

  1. The ‘type.__new__’ method collects all of the attributes in the
     class namespace that define a *note __set_name__(): e4a. method;

  2. Those ‘__set_name__’ methods are called with the class being
     defined and the assigned name of that particular attribute;

  3. The *note __init_subclass__(): 844. hook is called on the immediate
     parent of the new class in its method resolution order.

After the class object is created, it is passed to the class decorators
included in the class definition (if any) and the resulting object is
bound in the local namespace as the defined class.

When a new class is created by ‘type.__new__’, the object provided as
the namespace parameter is copied to a new ordered mapping and the
original object is discarded.  The new copy is wrapped in a read-only
proxy, which becomes the *note __dict__: e59. attribute of the class
object.

Vedi anche
..........

PEP 3135(1) - New super

     Describes the implicit ‘__class__’ closure reference

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3135/


File: python.info,  Node: Uses for metaclasses,  Prev: Creating the class object,  Up: Customizing class creation

4.3.3.14 Uses for metaclasses
.............................

The potential uses for metaclasses are boundless.  Some ideas that have
been explored include enum, logging, interface checking, automatic
delegation, automatic property creation, proxies, frameworks, and
automatic resource locking/synchronization.


File: python.info,  Node: Customizing instance and subclass checks,  Next: Emulating generic types,  Prev: Customizing class creation,  Up: Special method names

4.3.3.15 Customizing instance and subclass checks
.................................................

The following methods are used to override the default behavior of the
*note isinstance(): 2ad. and *note issubclass(): 9c6. built-in
functions.

In particular, the metaclass *note abc.ABCMeta: 111d. implements these
methods in order to allow the addition of Abstract Base Classes (ABCs)
as «virtual base classes» to any class or type (including built-in
types), including other ABCs.

 -- Metodo: type.__instancecheck__ (self, instance)

     Return true if 'instance' should be considered a (direct or
     indirect) instance of 'class'.  If defined, called to implement
     ‘isinstance(instance, class)’.

 -- Metodo: type.__subclasscheck__ (self, subclass)

     Return true if 'subclass' should be considered a (direct or
     indirect) subclass of 'class'.  If defined, called to implement
     ‘issubclass(subclass, class)’.

Note that these methods are looked up on the type (metaclass) of a
class.  They cannot be defined as class methods in the actual class.
This is consistent with the lookup of special methods that are called on
instances, only in this case the instance is itself a class.

Vedi anche
..........

PEP 3119(1) - Introducing Abstract Base Classes

     Includes the specification for customizing *note isinstance(): 2ad.
     and *note issubclass(): 9c6. behavior through *note
     __instancecheck__(): 23ac. and *note __subclasscheck__(): 23ad,
     with motivation for this functionality in the context of adding
     Abstract Base Classes (see the *note abc: 4. module) to the
     language.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3119/


File: python.info,  Node: Emulating generic types,  Next: Emulating callable objects,  Prev: Customizing instance and subclass checks,  Up: Special method names

4.3.3.16 Emulating generic types
................................

When using *note type annotations: 15c, it is often useful to
'parameterize' a *note generic type: 1a1. using Python’s square-brackets
notation.  For example, the annotation ‘list[int]’ might be used to
signify a *note list: 24d. in which all the elements are of type *note
int: 19b.

Vedi anche
..........

PEP 484(1) - Type Hints

     Introducing Python’s framework for type annotations

*note Generic Alias Types: 8c2.

     Documentation for objects representing parameterized generic
     classes

*note Generics: 23af, *note user-defined generics: 6f7. and *note typing.Generic: 179e.

     Documentation on how to implement generic classes that can be
     parameterized at runtime and understood by static type-checkers.

A class can 'generally' only be parameterized if it defines the special
class method ‘__class_getitem__()’.

 -- Metodo: classmethod object.__class_getitem__ (cls, key)

     Return an object representing the specialization of a generic class
     by type arguments found in 'key'.

     When defined on a class, ‘__class_getitem__()’ is automatically a
     class method.  As such, there is no need for it to be decorated
     with *note @classmethod: 48f. when it is defined.

* Menu:

* The purpose of __class_getitem__::
* __class_getitem__ versus __getitem__::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/


File: python.info,  Node: The purpose of __class_getitem__,  Next: __class_getitem__ versus __getitem__,  Up: Emulating generic types

4.3.3.17 The purpose of '__class_getitem__'
...........................................

The purpose of *note __class_getitem__(): 944. is to allow runtime
parameterization of standard-library generic classes in order to more
easily apply *note type hints: 23b1. to these classes.

To implement custom generic classes that can be parameterized at runtime
and understood by static type-checkers, users should either inherit from
a standard library class that already implements *note
__class_getitem__(): 944, or inherit from *note typing.Generic: 179e,
which has its own implementation of ‘__class_getitem__()’.

Custom implementations of *note __class_getitem__(): 944. on classes
defined outside of the standard library may not be understood by
third-party type-checkers such as mypy.  Using ‘__class_getitem__()’ on
any class for purposes other than type hinting is discouraged.


File: python.info,  Node: __class_getitem__ versus __getitem__,  Prev: The purpose of __class_getitem__,  Up: Emulating generic types

4.3.3.18 '__class_getitem__' versus '__getitem__'
.................................................

Usually, the *note subscription: 23b4. of an object using square
brackets will call the *note __getitem__(): 588. instance method defined
on the object’s class.  However, if the object being subscribed is
itself a class, the class method *note __class_getitem__(): 944. may be
called instead.  ‘__class_getitem__()’ should return a *note
GenericAlias: 8c2. object if it is properly defined.

Presented with the *note expression: 23b5. ‘obj[x]’, the Python
interpreter follows something like the following process to decide
whether *note __getitem__(): 588. or *note __class_getitem__(): 944.
should be called:

     from inspect import isclass

     def subscribe(obj, x):
         """Return the result of the expression 'obj[x]'"""

         class_of_obj = type(obj)

         # If the class of obj defines __getitem__,
         # call class_of_obj.__getitem__(obj, x)
         if hasattr(class_of_obj, '__getitem__'):
             return class_of_obj.__getitem__(obj, x)

         # Else, if obj is a class and defines __class_getitem__,
         # call obj.__class_getitem__(x)
         elif isclass(obj) and hasattr(obj, '__class_getitem__'):
             return obj.__class_getitem__(x)

         # Else, raise an exception
         else:
             raise TypeError(
                 f"'{class_of_obj.__name__}' object is not subscriptable"
             )

In Python, all classes are themselves instances of other classes.  The
class of a class is known as that class’s *note metaclass: 23b6, and
most classes have the *note type: f46. class as their metaclass.  *note
type: f46. does not define *note __getitem__(): 588, meaning that
expressions such as ‘list[int]’, ‘dict[str, float]’ and ‘tuple[str,
bytes]’ all result in *note __class_getitem__(): 944. being called:

     >>> # list has class "type" as its metaclass, like most classes:
     >>> type(list)
     <class 'type'>
     >>> type(dict) == type(list) == type(tuple) == type(str) == type(bytes)
     True
     >>> # "list[int]" calls "list.__class_getitem__(int)"
     >>> list[int]
     list[int]
     >>> # list.__class_getitem__ returns a GenericAlias object:
     >>> type(list[int])
     <class 'types.GenericAlias'>

However, if a class has a custom metaclass that defines *note
__getitem__(): 588, subscribing the class may result in different
behaviour.  An example of this can be found in the *note enum: 5a.
module:

     >>> from enum import Enum
     >>> class Menu(Enum):
     ...     """A breakfast menu"""
     ...     SPAM = 'spam'
     ...     BACON = 'bacon'
     ...
     >>> # Enum classes have a custom metaclass:
     >>> type(Menu)
     <class 'enum.EnumMeta'>
     >>> # EnumMeta defines __getitem__,
     >>> # so __class_getitem__ is not called,
     >>> # and the result is not a GenericAlias object:
     >>> Menu['SPAM']
     <Menu.SPAM: 'spam'>
     >>> type(Menu['SPAM'])
     <enum 'Menu'>

Vedi anche
..........

PEP 560(1) - Core Support for typing module and generic types

     Introducing *note __class_getitem__(): 944, and outlining when a
     *note subscription: 23b4. results in ‘__class_getitem__()’ being
     called instead of *note __getitem__(): 588.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0560/


File: python.info,  Node: Emulating callable objects,  Next: Emulating container types,  Prev: Emulating generic types,  Up: Special method names

4.3.3.19 Emulating callable objects
...................................

 -- Metodo: object.__call__ (self[, args...])

     Called when the instance is «called» as a function; if this method
     is defined, ‘x(arg1, arg2, ...)’ roughly translates to
     ‘type(x).__call__(x, arg1, ...)’.  The *note object: c80. class
     itself does not provide this method.


File: python.info,  Node: Emulating container types,  Next: Emulating numeric types,  Prev: Emulating callable objects,  Up: Special method names

4.3.3.20 Emulating container types
..................................

The following methods can be defined to implement container objects.
None of them are provided by the *note object: c80. class itself.
Containers usually are *note sequences: 717. (such as *note lists: 24d.
or *note tuples: 614.) or *note mappings: 13c3. (like *note
dictionaries: 23bb.), but can represent other containers as well.  The
first set of methods is used either to emulate a sequence or to emulate
a mapping; the difference is that for a sequence, the allowable keys
should be the integers 'k' for which ‘0 <= k < N’ where 'N' is the
length of the sequence, or *note slice: 695. objects, which define a
range of items.  It is also recommended that mappings provide the
methods ‘keys()’, ‘values()’, ‘items()’, ‘get()’, ‘clear()’,
‘setdefault()’, ‘pop()’, ‘popitem()’, ‘copy()’, and ‘update()’ behaving
similar to those for Python’s standard *note dictionary: 183. objects.
The *note collections.abc: 1f. module provides a *note MutableMapping:
12b4. *note abstract base class: 13be. to help create those methods from
a base set of *note __getitem__(): 588, *note __setitem__(): 14d3, *note
__delitem__(): 14d4, and ‘keys()’.

Mutable sequences should provide methods *note append(): 23bc, *note
clear(): 23bd, *note count(): 23be, *note extend(): 23bf, *note index():
1961, *note insert(): 23c0, *note pop(): 23c1, *note remove(): 1962, and
*note reverse(): 23c2, like Python standard *note list: 24d. objects.
Finally, sequence types should implement addition (meaning
concatenation) and multiplication (meaning repetition) by defining the
methods *note __add__(): 23c3, *note __radd__(): 23c4, *note __iadd__():
23c5, *note __mul__(): 23c6, *note __rmul__(): 23c7. and *note
__imul__(): 23c8. described below; they should not define other
numerical operators.

It is recommended that both mappings and sequences implement the *note
__contains__(): 15c1. method to allow efficient use of the ‘in’
operator; for mappings, ‘in’ should search the mapping’s keys; for
sequences, it should search through the values.  It is further
recommended that both mappings and sequences implement the *note
__iter__(): e6b. method to allow efficient iteration through the
container; for mappings, ‘__iter__()’ should iterate through the
object’s keys; for sequences, it should iterate through the values.

 -- Metodo: object.__len__ (self)

     Called to implement the built-in function *note len(): 841.  Should
     return the length of the object, an integer ‘>=’ 0.  Also, an
     object that doesn’t define a *note __bool__(): 14dd. method and
     whose ‘__len__()’ method returns zero is considered to be false in
     a Boolean context.

     'Dettaglio dell’implementazione di CPython:' In CPython, the length
     is required to be at most *note sys.maxsize: 13cd.  If the length
     is larger than ‘sys.maxsize’ some features (such as *note len():
     841.) may raise *note OverflowError: a83.  To prevent raising
     ‘OverflowError’ by truth value testing, an object must define a
     *note __bool__(): 14dd. method.

 -- Metodo: object.__length_hint__ (self)

     Called to implement *note operator.length_hint(): 116f.  Should
     return an estimated length for the object (which may be greater or
     less than the actual length).  The length must be an integer ‘>=’
     0.  The return value may also be *note NotImplemented: 1a2, which
     is treated the same as if the ‘__length_hint__’ method didn’t exist
     at all.  This method is purely an optimization and is never
     required for correctness.

     Added in version 3.4.

     Nota: Slicing is done exclusively with the following three methods.
     A call like

          a[1:2] = b

     is translated to

          a[slice(1, 2, None)] = b

     and so forth.  Missing slice items are always filled in with
     ‘None’.

 -- Metodo: object.__getitem__ (self, key)

     Called to implement evaluation of ‘self[key]’.  For *note sequence:
     717. types, the accepted keys should be integers.  Optionally, they
     may support *note slice: 695. objects as well.  Negative index
     support is also optional.  If 'key' is of an inappropriate type,
     *note TypeError: 198. may be raised; if 'key' is a value outside
     the set of indexes for the sequence (after any special
     interpretation of negative values), *note IndexError: 173c. should
     be raised.  For *note mapping: 13c3. types, if 'key' is missing
     (not in the container), *note KeyError: 5e7. should be raised.

          Nota: *note for: 34a. loops expect that an *note IndexError:
          173c. will be raised for illegal indexes to allow proper
          detection of the end of the sequence.

          Nota: When *note subscripting: 23b4. a 'class', the special
          class method *note __class_getitem__(): 944. may be called
          instead of ‘__getitem__()’.  See *note __class_getitem__
          versus __getitem__: 23b3. for more details.

 -- Metodo: object.__setitem__ (self, key, value)

     Called to implement assignment to ‘self[key]’.  Same note as for
     *note __getitem__(): 588.  This should only be implemented for
     mappings if the objects support changes to the values for keys, or
     if new keys can be added, or for sequences if elements can be
     replaced.  The same exceptions should be raised for improper 'key'
     values as for the *note __getitem__(): 588. method.

 -- Metodo: object.__delitem__ (self, key)

     Called to implement deletion of ‘self[key]’.  Same note as for
     *note __getitem__(): 588.  This should only be implemented for
     mappings if the objects support removal of keys, or for sequences
     if elements can be removed from the sequence.  The same exceptions
     should be raised for improper 'key' values as for the *note
     __getitem__(): 588. method.

 -- Metodo: object.__missing__ (self, key)

     Called by *note dict: 183.*note __getitem__(): 588. to implement
     ‘self[key]’ for dict subclasses when key is not in the dictionary.

 -- Metodo: object.__iter__ (self)

     This method is called when an *note iterator: 4c9. is required for
     a container.  This method should return a new iterator object that
     can iterate over all the objects in the container.  For mappings,
     it should iterate over the keys of the container.

 -- Metodo: object.__reversed__ (self)

     Called (if present) by the *note reversed(): a67. built-in to
     implement reverse iteration.  It should return a new iterator
     object that iterates over all the objects in the container in
     reverse order.

     If the *note __reversed__(): e88. method is not provided, the *note
     reversed(): a67. built-in will fall back to using the sequence
     protocol (*note __len__(): 1777. and *note __getitem__(): 588.).
     Objects that support the sequence protocol should only provide
     *note __reversed__(): e88. if they can provide an implementation
     that is more efficient than the one provided by *note reversed():
     a67.

The membership test operators (*note in: 34b. and *note not in: 842.)
are normally implemented as an iteration through a container.  However,
container objects can supply the following special method with a more
efficient implementation, which also does not require the object be
iterable.

 -- Metodo: object.__contains__ (self, item)

     Called to implement membership test operators.  Should return true
     if 'item' is in 'self', false otherwise.  For mapping objects, this
     should consider the keys of the mapping rather than the values or
     the key-item pairs.

     For objects that don’t define *note __contains__(): 15c1, the
     membership test first tries iteration via *note __iter__(): e6b,
     then the old sequence iteration protocol via *note __getitem__():
     588, see *note this section in the language reference: 23c9.


File: python.info,  Node: Emulating numeric types,  Next: With Statement Context Managers,  Prev: Emulating container types,  Up: Special method names

4.3.3.21 Emulating numeric types
................................

The following methods can be defined to emulate numeric objects.
Methods corresponding to operations that are not supported by the
particular kind of number implemented (e.g., bitwise operations for
non-integral numbers) should be left undefined.

 -- Metodo: object.__add__ (self, other)
 -- Metodo: object.__sub__ (self, other)
 -- Metodo: object.__mul__ (self, other)
 -- Metodo: object.__matmul__ (self, other)
 -- Metodo: object.__truediv__ (self, other)
 -- Metodo: object.__floordiv__ (self, other)
 -- Metodo: object.__mod__ (self, other)
 -- Metodo: object.__divmod__ (self, other)
 -- Metodo: object.__pow__ (self, other[, modulo])
 -- Metodo: object.__lshift__ (self, other)
 -- Metodo: object.__rshift__ (self, other)
 -- Metodo: object.__and__ (self, other)
 -- Metodo: object.__xor__ (self, other)
 -- Metodo: object.__or__ (self, other)

     These methods are called to implement the binary arithmetic
     operations (‘+’, ‘-’, ‘*’, ‘@’, ‘/’, ‘//’, ‘%’, *note divmod():
     b9b, *note pow(): 1a4, ‘**’, ‘<<’, ‘>>’, ‘&’, ‘^’, ‘|’).  For
     instance, to evaluate the expression ‘x + y’, where 'x' is an
     instance of a class that has an *note __add__(): 23c3. method,
     ‘type(x).__add__(x, y)’ is called.  The *note __divmod__(): 1093.
     method should be the equivalent to using *note __floordiv__():
     16fb. and *note __mod__(): 23cd.; it should not be related to *note
     __truediv__(): 1092.  Note that *note __pow__(): 9d6. should be
     defined to accept an optional third argument if the three-argument
     version of the built-in *note pow(): 1a4. function is to be
     supported.

     If one of those methods does not support the operation with the
     supplied arguments, it should return *note NotImplemented: 1a2.

 -- Metodo: object.__radd__ (self, other)
 -- Metodo: object.__rsub__ (self, other)
 -- Metodo: object.__rmul__ (self, other)
 -- Metodo: object.__rmatmul__ (self, other)
 -- Metodo: object.__rtruediv__ (self, other)
 -- Metodo: object.__rfloordiv__ (self, other)
 -- Metodo: object.__rmod__ (self, other)
 -- Metodo: object.__rdivmod__ (self, other)
 -- Metodo: object.__rpow__ (self, other[, modulo])
 -- Metodo: object.__rlshift__ (self, other)
 -- Metodo: object.__rrshift__ (self, other)
 -- Metodo: object.__rand__ (self, other)
 -- Metodo: object.__rxor__ (self, other)
 -- Metodo: object.__ror__ (self, other)

     These methods are called to implement the binary arithmetic
     operations (‘+’, ‘-’, ‘*’, ‘@’, ‘/’, ‘//’, ‘%’, *note divmod():
     b9b, *note pow(): 1a4, ‘**’, ‘<<’, ‘>>’, ‘&’, ‘^’, ‘|’) with
     reflected (swapped) operands.  These functions are only called if
     the operands are of different types, when the left operand does not
     support the corresponding operation (1), or the right operand’s
     class is derived from the left operand’s class.  (2)  For instance,
     to evaluate the expression ‘x - y’, where 'y' is an instance of a
     class that has an *note __rsub__(): 23d3. method,
     ‘type(y).__rsub__(y, x)’ is called if ‘type(x).__sub__(x, y)’
     returns *note NotImplemented: 1a2. or ‘type(y)’ is a subclass of
     ‘type(x)’.  (3)

     Note that *note __rpow__(): 1a5. should be defined to accept an
     optional third argument if the three-argument version of the
     built-in *note pow(): 1a4. function is to be supported.

     Cambiato nella versione 3.14: Three-argument *note pow(): 1a4. now
     try calling *note __rpow__(): 1a5. if necessary.  Previously it was
     only called in two-argument ‘pow()’ and the binary power operator.

          Nota: If the right operand’s type is a subclass of the left
          operand’s type and that subclass provides a different
          implementation of the reflected method for the operation, this
          method will be called before the left operand’s non-reflected
          method.  This behavior allows subclasses to override their
          ancestors” operations.

 -- Metodo: object.__iadd__ (self, other)
 -- Metodo: object.__isub__ (self, other)
 -- Metodo: object.__imul__ (self, other)
 -- Metodo: object.__imatmul__ (self, other)
 -- Metodo: object.__itruediv__ (self, other)
 -- Metodo: object.__ifloordiv__ (self, other)
 -- Metodo: object.__imod__ (self, other)
 -- Metodo: object.__ipow__ (self, other[, modulo])
 -- Metodo: object.__ilshift__ (self, other)
 -- Metodo: object.__irshift__ (self, other)
 -- Metodo: object.__iand__ (self, other)
 -- Metodo: object.__ixor__ (self, other)
 -- Metodo: object.__ior__ (self, other)

     These methods are called to implement the augmented arithmetic
     assignments (‘+=’, ‘-=’, ‘*=’, ‘@=’, ‘/=’, ‘//=’, ‘%=’, ‘**=’,
     ‘<<=’, ‘>>=’, ‘&=’, ‘^=’, ‘|=’).  These methods should attempt to
     do the operation in-place (modifying 'self') and return the result
     (which could be, but does not have to be, 'self').  If a specific
     method is not defined, or if that method returns *note
     NotImplemented: 1a2, the augmented assignment falls back to the
     normal methods.  For instance, if 'x' is an instance of a class
     with an *note __iadd__(): 23c5. method, ‘x += y’ is equivalent to
     ‘x = x.__iadd__(y)’ .  If *note __iadd__(): 23c5. does not exist,
     or if ‘x.__iadd__(y)’ returns ‘NotImplemented’, ‘x.__add__(y)’ and
     ‘y.__radd__(x)’ are considered, as with the evaluation of ‘x + y’.
     In certain situations, augmented assignment can result in
     unexpected errors (see *note Why does a_tuple[i] += [“item”] raise
     an exception when the addition works?: 23e5.), but this behavior is
     in fact part of the data model.

 -- Metodo: object.__neg__ (self)
 -- Metodo: object.__pos__ (self)
 -- Metodo: object.__abs__ (self)
 -- Metodo: object.__invert__ (self)

     Called to implement the unary arithmetic operations (‘-’, ‘+’,
     *note abs(): 2077. and ‘~’).

 -- Metodo: object.__complex__ (self)
 -- Metodo: object.__int__ (self)
 -- Metodo: object.__float__ (self)

     Called to implement the built-in functions *note complex(): 197,
     *note int(): 19b. and *note float(): 196.  Should return a value of
     the appropriate type.

 -- Metodo: object.__index__ (self)

     Called to implement *note operator.index(): 1cba, and whenever
     Python needs to losslessly convert the numeric object to an integer
     object (such as in slicing, or in the built-in *note bin(): 14b0,
     *note hex(): 14d7. and *note oct(): 14d6. functions).  Presence of
     this method indicates that the numeric object is an integer type.
     Must return an integer.

     If *note __int__(): 19d, *note __float__(): bc3. and *note
     __complex__(): 7fe. are not defined then corresponding built-in
     functions *note int(): 19b, *note float(): 196. and *note
     complex(): 197. fall back to *note __index__(): 19e.

 -- Metodo: object.__round__ (self[, ndigits])
 -- Metodo: object.__trunc__ (self)
 -- Metodo: object.__floor__ (self)
 -- Metodo: object.__ceil__ (self)

     Called to implement the built-in function *note round(): 14e2. and
     *note math: 92. functions *note trunc(): 15c7, *note floor(): 15c5.
     and *note ceil(): 15c6.  Unless 'ndigits' is passed to
     ‘__round__()’ all these methods should return the value of the
     object truncated to an *note Integral: 23ed. (typically an *note
     int: 19b.).

     Cambiato nella versione 3.14: *note int(): 19b. no longer delegates
     to the *note __trunc__(): 19c. method.

   ---------- Footnotes ----------

   (1) «Does not support» here means that the class has no such method,
or the method returns *note NotImplemented: 1a2.  Do not set the method
to ‘None’ if you want to force fallback to the right operand’s reflected
method—that will instead have the opposite effect of explicitly
'blocking' such fallback.

   (2) For operands of the same type, it is assumed that if the
non-reflected method (such as *note __add__(): 23c3.) fails then the
operation is not supported, which is why the reflected method is not
called.

   (3) If the right operand’s type is a subclass of the left operand’s
type, the reflected method having precedence allows subclasses to
override their ancestors” operations.


File: python.info,  Node: With Statement Context Managers,  Next: Customizing positional arguments in class pattern matching,  Prev: Emulating numeric types,  Up: Special method names

4.3.3.22 With Statement Context Managers
........................................

A 'context manager' is an object that defines the runtime context to be
established when executing a *note with: 186. statement.  The context
manager handles the entry into, and the exit from, the desired runtime
context for the execution of the block of code.  Context managers are
normally invoked using the ‘with’ statement (described in section *note
The with statement: 186.), but can also be used by directly invoking
their methods.

Typical uses of context managers include saving and restoring various
kinds of global state, locking and unlocking resources, closing opened
files, etc.

For more information on context managers, see *note Tipi di gestori di
contesti: 23f0.  The *note object: c80. class itself does not provide
the context manager methods.

 -- Metodo: object.__enter__ (self)

     Enter the runtime context related to this object.  The *note with:
     186. statement will bind this method’s return value to the
     target(s) specified in the ‘as’ clause of the statement, if any.

 -- Metodo: object.__exit__ (self, exc_type, exc_value, traceback)

     Exit the runtime context related to this object.  The parameters
     describe the exception that caused the context to be exited.  If
     the context was exited without an exception, all three arguments
     will be *note None: 886.

     If an exception is supplied, and the method wishes to suppress the
     exception (i.e., prevent it from being propagated), it should
     return a true value.  Otherwise, the exception will be processed
     normally upon exit from this method.

     Note that *note __exit__(): 1508. methods should not reraise the
     passed-in exception; this is the caller’s responsibility.

Vedi anche
..........

PEP 343(1) - The «with» statement

     The specification, background, and examples for the Python *note
     with: 186. statement.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0343/


File: python.info,  Node: Customizing positional arguments in class pattern matching,  Next: Emulating buffer types,  Prev: With Statement Context Managers,  Up: Special method names

4.3.3.23 Customizing positional arguments in class pattern matching
...................................................................

When using a class name in a pattern, positional arguments in the
pattern are not allowed by default, i.e.  ‘case MyClass(x, y)’ is
typically invalid without special support in ‘MyClass’.  To be able to
use that kind of pattern, the class needs to define a '__match_args__'
attribute.

 -- Dati: object.__match_args__

     This class variable can be assigned a tuple of strings.  When this
     class is used in a class pattern with positional arguments, each
     positional argument will be converted into a keyword argument,
     using the corresponding value in '__match_args__' as the keyword.
     The absence of this attribute is equivalent to setting it to ‘()’.

For example, if ‘MyClass.__match_args__’ is ‘("left", "center",
"right")’ that means that ‘case MyClass(x, y)’ is equivalent to ‘case
MyClass(left=x, center=y)’.  Note that the number of arguments in the
pattern must be smaller than or equal to the number of elements in
'__match_args__'; if it is larger, the pattern match attempt will raise
a *note TypeError: 198.

Added in version 3.10.

Vedi anche
..........

PEP 634(1) - Structural Pattern Matching

     The specification for the Python ‘match’ statement.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0634/


File: python.info,  Node: Emulating buffer types,  Next: Annotations,  Prev: Customizing positional arguments in class pattern matching,  Up: Special method names

4.3.3.24 Emulating buffer types
...............................

The *note buffer protocol: 260. provides a way for Python objects to
expose efficient access to a low-level memory array.  This protocol is
implemented by builtin types such as *note bytes: 192. and *note
memoryview: 165, and third-party libraries may define additional buffer
types.

While buffer types are usually implemented in C, it is also possible to
implement the protocol in Python.

 -- Metodo: object.__buffer__ (self, flags)

     Called when a buffer is requested from 'self' (for example, by the
     *note memoryview: 165. constructor).  The 'flags' argument is an
     integer representing the kind of buffer requested, affecting for
     example whether the returned buffer is read-only or writable.
     *note inspect.BufferFlags: 68e. provides a convenient way to
     interpret the flags.  The method must return a *note memoryview:
     165. object.

 -- Metodo: object.__release_buffer__ (self, buffer)

     Called when a buffer is no longer needed.  The 'buffer' argument is
     a *note memoryview: 165. object that was previously returned by
     *note __buffer__(): 68d.  The method must release any resources
     associated with the buffer.  This method should return ‘None’.
     Buffer objects that do not need to perform any cleanup are not
     required to implement this method.

Added in version 3.12.

Vedi anche
..........

PEP 688(1) - Making the buffer protocol accessible in Python

     Introduces the Python ‘__buffer__’ and ‘__release_buffer__’
     methods.

*note collections.abc.Buffer: 343.

     ABC for buffer types.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0688/


File: python.info,  Node: Annotations,  Next: Special method lookup,  Prev: Emulating buffer types,  Up: Special method names

4.3.3.25 Annotations
....................

Functions, classes, and modules may contain *note annotations: 15c,
which are a way to associate information (usually *note type hints:
23b1.) with a symbol.

 -- Attributo: object.__annotations__

     This attribute contains the annotations for an object.  It is *note
     lazily evaluated: 686, so accessing the attribute may execute
     arbitrary code and raise exceptions.  If evaluation is successful,
     the attribute is set to a dictionary mapping from variable names to
     annotations.

     Cambiato nella versione 3.14: Annotations are now lazily evaluated.

 -- Metodo: object.__annotate__ (format)

     An *note annotate function: 15d.  Returns a new dictionary object
     mapping attribute/parameter names to their annotation values.

     Takes a format parameter specifying the format in which annotations
     values should be provided.  It must be a member of the *note
     annotationlib.Format: 230. enum, or an integer with a value
     corresponding to a member of the enum.

     If an annotate function doesn’t support the requested format, it
     must raise *note NotImplementedError: 36b.  Annotate functions must
     always support *note VALUE: 15e. format; they must not raise *note
     NotImplementedError(): 36b. when called with this format.

     When called with *note VALUE: 15e. format, an annotate function may
     raise *note NameError: 452.; it must not raise ‘NameError’ when
     called requesting any other format.

     If an object does not have any annotations, *note __annotate__:
     196b. should preferably be set to ‘None’ (it can’t be deleted),
     rather than set to a function that returns an empty dict.

     Added in version 3.14.

Vedi anche
..........

PEP 649(1) — Deferred evaluation of annotation using descriptors

     Introduces lazy evaluation of annotations and the ‘__annotate__’
     function.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0649/


File: python.info,  Node: Special method lookup,  Prev: Annotations,  Up: Special method names

4.3.3.26 Special method lookup
..............................

For custom classes, implicit invocations of special methods are only
guaranteed to work correctly if defined on an object’s type, not in the
object’s instance dictionary.  That behaviour is the reason why the
following code raises an exception:

     >>> class C:
     ...     pass
     ...
     >>> c = C()
     >>> c.__len__ = lambda: 5
     >>> len(c)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: object of type 'C' has no len()

The rationale behind this behaviour lies with a number of special
methods such as *note __hash__(): cf5. and *note __repr__(): 830. that
are implemented by all objects, including type objects.  If the implicit
lookup of these methods used the conventional lookup process, they would
fail when invoked on the type object itself:

     >>> 1 .__hash__() == hash(1)
     True
     >>> int.__hash__() == hash(int)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: descriptor '__hash__' of 'int' object needs an argument

Incorrectly attempting to invoke an unbound method of a class in this
way is sometimes referred to as “metaclass confusion”, and is avoided by
bypassing the instance when looking up special methods:

     >>> type(1).__hash__(1) == hash(1)
     True
     >>> type(int).__hash__(int) == hash(int)
     True

In addition to bypassing any instance attributes in the interest of
correctness, implicit special method lookup generally also bypasses the
*note __getattribute__(): dcd. method even of the object’s metaclass:

     >>> class Meta(type):
     ...     def __getattribute__(*args):
     ...         print("Metaclass getattribute invoked")
     ...         return type.__getattribute__(*args)
     ...
     >>> class C(object, metaclass=Meta):
     ...     def __len__(self):
     ...         return 10
     ...     def __getattribute__(*args):
     ...         print("Class getattribute invoked")
     ...         return object.__getattribute__(*args)
     ...
     >>> c = C()
     >>> c.__len__()                 # Explicit lookup via instance
     Class getattribute invoked
     10
     >>> type(c).__len__(c)          # Explicit lookup via type
     Metaclass getattribute invoked
     10
     >>> len(c)                      # Implicit lookup
     10

Bypassing the *note __getattribute__(): dcd. machinery in this fashion
provides significant scope for speed optimisations within the
interpreter, at the cost of some flexibility in the handling of special
methods (the special method 'must' be set on the class object itself in
order to be consistently invoked by the interpreter).


File: python.info,  Node: Coroutines,  Prev: Special method names,  Up: Data model

4.3.4 Coroutines
----------------

* Menu:

* Awaitable Objects::
* Coroutine Objects::
* Asynchronous Iterators::
* Asynchronous Context Managers::


File: python.info,  Node: Awaitable Objects,  Next: Coroutine Objects,  Up: Coroutines

4.3.4.1 Awaitable Objects
.........................

An *note awaitable: 4ca. object generally implements an *note
__await__(): f77. method.  *note Coroutine objects: 6ba. returned from
*note async def: 7ee. functions are awaitable.

     Nota: The *note generator iterator: ddb. objects returned from
     generators decorated with *note types.coroutine(): 108a. are also
     awaitable, but they do not implement *note __await__(): f77.

 -- Metodo: object.__await__ (self)

     Must return an *note iterator: 4c9.  Should be used to implement
     *note awaitable: 4ca. objects.  For instance, *note asyncio.Future:
     dc8. implements this method to be compatible with the *note await:
     18d. expression.  The *note object: c80. class itself is not
     awaitable and does not provide this method.

          Nota: The language doesn’t place any restriction on the type
          or value of the objects yielded by the iterator returned by
          ‘__await__’, as this is specific to the implementation of the
          asynchronous execution framework (e.g.  *note asyncio: b.)
          that will be managing the *note awaitable: 4ca. object.

Added in version 3.5.

Vedi anche
..........

PEP 492(1) for additional information about awaitable objects.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0492/


File: python.info,  Node: Coroutine Objects,  Next: Asynchronous Iterators,  Prev: Awaitable Objects,  Up: Coroutines

4.3.4.2 Coroutine Objects
.........................

*note Coroutine objects: 6ba. are *note awaitable: 4ca. objects.  A
coroutine’s execution can be controlled by calling *note __await__():
f77. and iterating over the result.  When the coroutine has finished
executing and returns, the iterator raises *note StopIteration: df7, and
the exception’s *note value: 23fa. attribute holds the return value.  If
the coroutine raises an exception, it is propagated by the iterator.
Coroutines should not directly raise unhandled *note StopIteration: df7.
exceptions.

Coroutines also have the methods listed below, which are analogous to
those of generators (see *note Generator-iterator methods: 23fb.).
However, unlike generators, coroutines do not directly support
iteration.

Cambiato nella versione 3.5.2: It is a *note RuntimeError: 244. to await
on a coroutine more than once.

 -- Metodo: coroutine.send (value)

     Starts or resumes execution of the coroutine.  If 'value' is
     ‘None’, this is equivalent to advancing the iterator returned by
     *note __await__(): f77.  If 'value' is not ‘None’, this method
     delegates to the *note send(): 23fd. method of the iterator that
     caused the coroutine to suspend.  The result (return value, *note
     StopIteration: df7, or other exception) is the same as when
     iterating over the ‘__await__()’ return value, described above.

 -- Metodo: coroutine.throw (value)

 -- Metodo: coroutine.throw (type[, value[, traceback]])

     Raises the specified exception in the coroutine.  This method
     delegates to the *note throw(): 71d. method of the iterator that
     caused the coroutine to suspend, if it has such a method.
     Otherwise, the exception is raised at the suspension point.  The
     result (return value, *note StopIteration: df7, or other exception)
     is the same as when iterating over the *note __await__(): f77.
     return value, described above.  If the exception is not caught in
     the coroutine, it propagates back to the caller.

     Cambiato nella versione 3.12: The second signature (type[, value[,
     traceback]]) is deprecated and may be removed in a future version
     of Python.

 -- Metodo: coroutine.close ()

     Causes the coroutine to clean itself up and exit.  If the coroutine
     is suspended, this method first delegates to the *note close():
     177b. method of the iterator that caused the coroutine to suspend,
     if it has such a method.  Then it raises *note GeneratorExit: 15cf.
     at the suspension point, causing the coroutine to immediately clean
     itself up.  Finally, the coroutine is marked as having finished
     executing, even if it was never started.

     Coroutine objects are automatically closed using the above process
     when they are about to be destroyed.


File: python.info,  Node: Asynchronous Iterators,  Next: Asynchronous Context Managers,  Prev: Coroutine Objects,  Up: Coroutines

4.3.4.3 Asynchronous Iterators
..............................

An 'asynchronous iterator' can call asynchronous code in its ‘__anext__’
method.

Asynchronous iterators can be used in an *note async for: ca3.
statement.

The *note object: c80. class itself does not provide these methods.

 -- Metodo: object.__aiter__ (self)

     Must return an 'asynchronous iterator' object.

 -- Metodo: object.__anext__ (self)

     Must return an 'awaitable' resulting in a next value of the
     iterator.  Should raise a *note StopAsyncIteration: 1df7. error
     when the iteration is over.

An example of an asynchronous iterable object:

     class Reader:
         async def readline(self):
             ...

         def __aiter__(self):
             return self

         async def __anext__(self):
             val = await self.readline()
             if val == b'':
                 raise StopAsyncIteration
             return val

Added in version 3.5.

Cambiato nella versione 3.7: Prior to Python 3.7, *note __aiter__():
df8. could return an 'awaitable' that would resolve to an *note
asynchronous iterator: 4c8.

Starting with Python 3.7, *note __aiter__(): df8. must return an
asynchronous iterator object.  Returning anything else will result in a
*note TypeError: 198. error.


File: python.info,  Node: Asynchronous Context Managers,  Prev: Asynchronous Iterators,  Up: Coroutines

4.3.4.4 Asynchronous Context Managers
.....................................

An 'asynchronous context manager' is a 'context manager' that is able to
suspend execution in its ‘__aenter__’ and ‘__aexit__’ methods.

Asynchronous context managers can be used in an *note async with: 185.
statement.

The *note object: c80. class itself does not provide these methods.

 -- Metodo: object.__aenter__ (self)

     Semantically similar to *note __enter__(): 7e5, the only difference
     being that it must return an 'awaitable'.

 -- Metodo: object.__aexit__ (self, exc_type, exc_value, traceback)

     Semantically similar to *note __exit__(): 1508, the only difference
     being that it must return an 'awaitable'.

An example of an asynchronous context manager class:

     class AsyncContextManager:
         async def __aenter__(self):
             await log('entering context')

         async def __aexit__(self, exc_type, exc, tb):
             await log('exiting context')

Added in version 3.5.


File: python.info,  Node: Execution model,  Next: The import system,  Prev: Data model,  Up: The Python Language Reference

4.4 Execution model
===================

* Menu:

* Structure of a program::
* Naming and binding::
* Exceptions::
* Runtime Components::


File: python.info,  Node: Structure of a program,  Next: Naming and binding,  Up: Execution model

4.4.1 Structure of a program
----------------------------

A Python program is constructed from code blocks.  A 'block' is a piece
of Python program text that is executed as a unit.  The following are
blocks: a module, a function body, and a class definition.  Each command
typed interactively is a block.  A script file (a file given as standard
input to the interpreter or specified as a command line argument to the
interpreter) is a code block.  A script command (a command specified on
the interpreter command line with the *note -c: 1a8. option) is a code
block.  A module run as a top level script (as module ‘__main__’) from
the command line using a *note -m: 23c. argument is also a code block.
The string argument passed to the built-in functions *note eval(): 4a4.
and *note exec(): 4a3. is a code block.

A code block is executed in an 'execution frame'.  A frame contains some
administrative information (used for debugging) and determines where and
how execution continues after the code block’s execution has completed.


File: python.info,  Node: Naming and binding,  Next: Exceptions,  Prev: Structure of a program,  Up: Execution model

4.4.2 Naming and binding
------------------------

* Menu:

* Binding of names::
* Resolution of names::
* Annotation scopes::
* Lazy evaluation::
* Builtins and restricted execution::
* Interaction with dynamic features::


File: python.info,  Node: Binding of names,  Next: Resolution of names,  Up: Naming and binding

4.4.2.1 Binding of names
........................

'Names' refer to objects.  Names are introduced by name binding
operations.

The following constructs bind names:

   * formal parameters to functions,

   * class definitions,

   * function definitions,

   * assignment expressions,

   * *note targets: 240b. that are identifiers if occurring in an
     assignment:

        + *note for: 34a. loop header,

        + after ‘as’ in a *note with: 186. statement, *note except: 1ab.
          clause, *note except*: 1ac. clause, or in the as-pattern in
          structural pattern matching,

        + in a capture pattern in structural pattern matching

   * *note import: 7f9. statements.

   * *note type: 66d. statements.

   * *note type parameter lists: 5ad.

The ‘import’ statement of the form ‘from ... import *’ binds all names
defined in the imported module, except those beginning with an
underscore.  This form may only be used at the module level.

A target occurring in a *note del: 1b07. statement is also considered
bound for this purpose (though the actual semantics are to unbind the
name).

Each assignment or import statement occurs within a block defined by a
class or function definition or at the module level (the top-level code
block).

If a name is bound in a block, it is a local variable of that block,
unless declared as *note nonlocal: 14af. or *note global: 4ad.  If a
name is bound at the module level, it is a global variable.  (The
variables of the module code block are local and global.)  If a variable
is used in a code block but not defined there, it is a *note free
variable: 240c.

Each occurrence of a name in the program text refers to the 'binding' of
that name established by the following name resolution rules.


File: python.info,  Node: Resolution of names,  Next: Annotation scopes,  Prev: Binding of names,  Up: Naming and binding

4.4.2.2 Resolution of names
...........................

A 'scope' defines the visibility of a name within a block.  If a local
variable is defined in a block, its scope includes that block.  If the
definition occurs in a function block, the scope extends to any blocks
contained within the defining one, unless a contained block introduces a
different binding for the name.

When a name is used in a code block, it is resolved using the nearest
enclosing scope.  The set of all such scopes visible to a code block is
called the block’s 'environment'.

When a name is not found at all, a *note NameError: 452. exception is
raised.  If the current scope is a function scope, and the name refers
to a local variable that has not yet been bound to a value at the point
where the name is used, an *note UnboundLocalError: 173d. exception is
raised.  *note UnboundLocalError: 173d. is a subclass of *note
NameError: 452.

If a name binding operation occurs anywhere within a code block, all
uses of the name within the block are treated as references to the
current block.  This can lead to errors when a name is used within a
block before it is bound.  This rule is subtle.  Python lacks
declarations and allows name binding operations to occur anywhere within
a code block.  The local variables of a code block can be determined by
scanning the entire text of the block for name binding operations.  See
*note the FAQ entry on UnboundLocalError: 240f. for examples.

If the *note global: 4ad. statement occurs within a block, all uses of
the names specified in the statement refer to the bindings of those
names in the top-level namespace.  Names are resolved in the top-level
namespace by searching the global namespace, i.e.  the namespace of the
module containing the code block, and the builtins namespace, the
namespace of the module *note builtins: 13.  The global namespace is
searched first.  If the names are not found there, the builtins
namespace is searched next.  If the names are also not found in the
builtins namespace, new variables are created in the global namespace.
The global statement must precede all uses of the listed names.

The *note global: 4ad. statement has the same scope as a name binding
operation in the same block.  If the nearest enclosing scope for a free
variable contains a global statement, the free variable is treated as a
global.

The *note nonlocal: 14af. statement causes corresponding names to refer
to previously bound variables in the nearest enclosing function scope.
*note SyntaxError: 18e. is raised at compile time if the given name does
not exist in any enclosing function scope.  *note Type parameters: 5ad.
cannot be rebound with the ‘nonlocal’ statement.

The namespace for a module is automatically created the first time a
module is imported.  The main module for a script is always called *note
__main__: 1.

Class definition blocks and arguments to *note exec(): 4a3. and *note
eval(): 4a4. are special in the context of name resolution.  A class
definition is an executable statement that may use and define names.
These references follow the normal rules for name resolution with an
exception that unbound local variables are looked up in the global
namespace.  The namespace of the class definition becomes the attribute
dictionary of the class.  The scope of names defined in a class block is
limited to the class block; it does not extend to the code blocks of
methods.  This includes comprehensions and generator expressions, but it
does not include *note annotation scopes: 4ac, which have access to
their enclosing class scopes.  This means that the following will fail:

     class A:
         a = 42
         b = list(a + i for i in range(10))

However, the following will succeed:

     class A:
         type Alias = Nested
         class Nested: pass

     print(A.Alias.__value__)  # <type 'A.Nested'>


File: python.info,  Node: Annotation scopes,  Next: Lazy evaluation,  Prev: Resolution of names,  Up: Naming and binding

4.4.2.3 Annotation scopes
.........................

*note Annotations: 15c, *note type parameter lists: 5ad. and *note type:
66d. statements introduce 'annotation scopes', which behave mostly like
function scopes, but with some exceptions discussed below.

Annotation scopes are used in the following contexts:

   * *note Function annotations: 2003.

   * *note Variable annotations: f53.

   * Type parameter lists for *note generic type aliases: 685.

   * Type parameter lists for *note generic functions: 683.  A generic
     function’s annotations are executed within the annotation scope,
     but its defaults and decorators are not.

   * Type parameter lists for *note generic classes: 682.  A generic
     class’s base classes and keyword arguments are executed within the
     annotation scope, but its decorators are not.

   * The bounds, constraints, and default values for type parameters
     (*note lazily evaluated: 686.).

   * The value of type aliases (*note lazily evaluated: 686.).

Annotation scopes differ from function scopes in the following ways:

   * Annotation scopes have access to their enclosing class namespace.
     If an annotation scope is immediately within a class scope, or
     within another annotation scope that is immediately within a class
     scope, the code in the annotation scope can use names defined in
     the class scope as if it were executed directly within the class
     body.  This contrasts with regular functions defined within
     classes, which cannot access names defined in the class scope.

   * Expressions in annotation scopes cannot contain *note yield: bc4,
     ‘yield from’, *note await: 18d, or *note ;=: 2411. expressions.
     (These expressions are allowed in other scopes contained within the
     annotation scope.)

   * Names defined in annotation scopes cannot be rebound with *note
     nonlocal: 14af. statements in inner scopes.  This includes only
     type parameters, as no other syntactic elements that can appear
     within annotation scopes can introduce new names.

   * While annotation scopes have an internal name, that name is not
     reflected in the *note qualified name: 1d0c. of objects defined
     within the scope.  Instead, the *note __qualname__: 1267. of such
     objects is as if the object were defined in the enclosing scope.

Added in version 3.12: Annotation scopes were introduced in Python 3.12
as part of PEP 695(1).

Cambiato nella versione 3.13: Annotation scopes are also used for type
parameter defaults, as introduced by PEP 696(2).

Cambiato nella versione 3.14: Annotation scopes are now also used for
annotations, as specified in PEP 649(3) and PEP 749(4).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0695/

   (2) https://peps.python.org/pep-0696/

   (3) https://peps.python.org/pep-0649/

   (4) https://peps.python.org/pep-0749/


File: python.info,  Node: Lazy evaluation,  Next: Builtins and restricted execution,  Prev: Annotation scopes,  Up: Naming and binding

4.4.2.4 Lazy evaluation
.......................

Most annotation scopes are 'lazily evaluated'.  This includes
annotations, the values of type aliases created through the *note type:
66d. statement, and the bounds, constraints, and default values of type
variables created through the *note type parameter syntax: 5ad.  This
means that they are not evaluated when the type alias or type variable
is created, or when the object carrying annotations is created.
Instead, they are only evaluated when necessary, for example when the
‘__value__’ attribute on a type alias is accessed.

Example:

     >>> type Alias = 1/0
     >>> Alias.__value__
     Traceback (most recent call last):
       ...
     ZeroDivisionError: division by zero
     >>> def func[T: 1/0](): pass
     >>> T = func.__type_params__[0]
     >>> T.__bound__
     Traceback (most recent call last):
       ...
     ZeroDivisionError: division by zero

Here the exception is raised only when the ‘__value__’ attribute of the
type alias or the ‘__bound__’ attribute of the type variable is
accessed.

This behavior is primarily useful for references to types that have not
yet been defined when the type alias or type variable is created.  For
example, lazy evaluation enables creation of mutually recursive type
aliases:

     from typing import Literal

     type SimpleExpr = int | Parenthesized
     type Parenthesized = tuple[Literal["("], Expr, Literal[")"]]
     type Expr = SimpleExpr | tuple[SimpleExpr, Literal["+", "-"], Expr]

Lazily evaluated values are evaluated in *note annotation scope: 4ac,
which means that names that appear inside the lazily evaluated value are
looked up as if they were used in the immediately enclosing scope.

Added in version 3.12.


File: python.info,  Node: Builtins and restricted execution,  Next: Interaction with dynamic features,  Prev: Lazy evaluation,  Up: Naming and binding

4.4.2.5 Builtins and restricted execution
.........................................

'Dettaglio dell’implementazione di CPython:' Users should not touch
‘__builtins__’; it is strictly an implementation detail.  Users wanting
to override values in the builtins namespace should *note import: 7f9.
the *note builtins: 13. module and modify its attributes appropriately.

The builtins namespace associated with the execution of a code block is
actually found by looking up the name ‘__builtins__’ in its global
namespace; this should be a dictionary or a module (in the latter case
the module’s dictionary is used).  By default, when in the *note
__main__: 1. module, ‘__builtins__’ is the built-in module *note
builtins: 13.; when in any other module, ‘__builtins__’ is an alias for
the dictionary of the *note builtins: 13. module itself.


File: python.info,  Node: Interaction with dynamic features,  Prev: Builtins and restricted execution,  Up: Naming and binding

4.4.2.6 Interaction with dynamic features
.........................................

Name resolution of free variables occurs at runtime, not at compile
time.  This means that the following code will print 42:

     i = 10
     def f():
         print(i)
     i = 42
     f()

The *note eval(): 4a4. and *note exec(): 4a3. functions do not have
access to the full environment for resolving names.  Names may be
resolved in the local and global namespaces of the caller.  Free
variables are not resolved in the nearest enclosing namespace, but in
the global namespace.  (1)  The *note exec(): 4a3. and *note eval():
4a4. functions have optional arguments to override the global and local
namespace.  If only one namespace is specified, it is used for both.

   ---------- Footnotes ----------

   (1) This limitation occurs because the code that is executed by these
operations is not available at the time the module is compiled.


File: python.info,  Node: Exceptions,  Next: Runtime Components,  Prev: Naming and binding,  Up: Execution model

4.4.3 Exceptions
----------------

Exceptions are a means of breaking out of the normal flow of control of
a code block in order to handle errors or other exceptional conditions.
An exception is 'raised' at the point where the error is detected; it
may be 'handled' by the surrounding code block or by any code block that
directly or indirectly invoked the code block where the error occurred.

The Python interpreter raises an exception when it detects a run-time
error (such as division by zero).  A Python program can also explicitly
raise an exception with the *note raise: 804. statement.  Exception
handlers are specified with the *note try: 8f9. … *note except: 1ab.
statement.  The *note finally: 1b0. clause of such a statement can be
used to specify cleanup code which does not handle the exception, but is
executed whether an exception occurred or not in the preceding code.

Python uses the «termination» model of error handling: an exception
handler can find out what happened and continue execution at an outer
level, but it cannot repair the cause of the error and retry the failing
operation (except by re-entering the offending piece of code from the
top).

When an exception is not handled at all, the interpreter terminates
execution of the program, or returns to its interactive main loop.  In
either case, it prints a stack traceback, except when the exception is
*note SystemExit: f3e.

Exceptions are identified by class instances.  The *note except: 1ab.
clause is selected depending on the class of the instance: it must
reference the class of the instance or a *note non-virtual base class:
13be. thereof.  The instance can be received by the handler and can
carry additional information about the exceptional condition.

     Nota: Exception messages are not part of the Python API. Their
     contents may change from one version of Python to the next without
     warning and should not be relied on by code which will run under
     multiple versions of the interpreter.

See also the description of the *note try: 8f9. statement in section
*note The try statement: 8f9. and *note raise: 804. statement in section
*note The raise statement: 804.


File: python.info,  Node: Runtime Components,  Prev: Exceptions,  Up: Execution model

4.4.4 Runtime Components
------------------------

* Menu:

* General Computing Model::
* Python Runtime Model::


File: python.info,  Node: General Computing Model,  Next: Python Runtime Model,  Up: Runtime Components

4.4.4.1 General Computing Model
...............................

Python’s execution model does not operate in a vacuum.  It runs on a
host machine and through that host’s runtime environment, including its
operating system (OS), if there is one.  When a program runs, the
conceptual layers of how it runs on the host look something like this:

          'host machine'
               'process' (global resources)
                    'thread' (runs machine code)

Each process represents a program running on the host.  Think of each
process itself as the data part of its program.  Think of the process”
threads as the execution part of the program.  This distinction will be
important to understand the conceptual Python runtime.

The process, as the data part, is the execution context in which the
program runs.  It mostly consists of the set of resources assigned to
the program by the host, including memory, signals, file handles,
sockets, and environment variables.

Processes are isolated and independent from one another.  (The same is
true for hosts.)  The host manages the process” access to its assigned
resources, in addition to coordinating between processes.

Each thread represents the actual execution of the program’s machine
code, running relative to the resources assigned to the program’s
process.  It’s strictly up to the host how and when that execution takes
place.

From the point of view of Python, a program always starts with exactly
one thread.  However, the program may grow to run in multiple
simultaneous threads.  Not all hosts support multiple threads per
process, but most do.  Unlike processes, threads in a process are not
isolated and independent from one another.  Specifically, all threads in
a process share all of the process” resources.

The fundamental point of threads is that each one does 'run'
independently, at the same time as the others.  That may be only
conceptually at the same time («concurrently») or physically («in
parallel»).  Either way, the threads effectively run at a
non-synchronized rate.

     Nota: That non-synchronized rate means none of the process” memory
     is guaranteed to stay consistent for the code running in any given
     thread.  Thus multi-threaded programs must take care to coordinate
     access to intentionally shared resources.  Likewise, they must take
     care to be absolutely diligent about not accessing any 'other'
     resources in multiple threads; otherwise two threads running at the
     same time might accidentally interfere with each other’s use of
     some shared data.  All this is true for both Python programs and
     the Python runtime.

     The cost of this broad, unstructured requirement is the tradeoff
     for the kind of raw concurrency that threads provide.  The
     alternative to the required discipline generally means dealing with
     non-deterministic bugs and data corruption.


File: python.info,  Node: Python Runtime Model,  Prev: General Computing Model,  Up: Runtime Components

4.4.4.2 Python Runtime Model
............................

The same conceptual layers apply to each Python program, with some extra
data layers specific to Python:

          'host machine'
               'process' (global resources)
                    Python global runtime ('state')
                         Python interpreter ('state')
                              'thread' (runs Python bytecode and «C-API»)
                                   Python thread 'state'

At the conceptual level: when a Python program starts, it looks exactly
like that diagram, with one of each.  The runtime may grow to include
multiple interpreters, and each interpreter may grow to include multiple
thread states.

     Nota: A Python implementation won’t necessarily implement the
     runtime layers distinctly or even concretely.  The only exception
     is places where distinct layers are directly specified or exposed
     to users, like through the *note threading: f3. module.

     Nota: The initial interpreter is typically called the «main»
     interpreter.  Some Python implementations, like CPython, assign
     special roles to the main interpreter.

     Likewise, the host thread where the runtime was initialized is
     known as the «main» thread.  It may be different from the process”
     initial thread, though they are often the same.  In some cases
     «main thread» may be even more specific and refer to the initial
     thread state.  A Python runtime might assign specific
     responsibilities to the main thread, such as handling signals.

As a whole, the Python runtime consists of the global runtime state,
interpreters, and thread states.  The runtime ensures all that state
stays consistent over its lifetime, particularly when used with multiple
host threads.

The global runtime, at the conceptual level, is just a set of
interpreters.  While those interpreters are otherwise isolated and
independent from one another, they may share some data or other
resources.  The runtime is responsible for managing these global
resources safely.  The actual nature and management of these resources
is implementation-specific.  Ultimately, the external utility of the
global runtime is limited to managing interpreters.

In contrast, an «interpreter» is conceptually what we would normally
think of as the (full-featured) «Python runtime».  When machine code
executing in a host thread interacts with the Python runtime, it calls
into Python in the context of a specific interpreter.

     Nota: The term «interpreter» here is not the same as the «bytecode
     interpreter», which is what regularly runs in threads, executing
     compiled Python code.

     In an ideal world, «Python runtime» would refer to what we
     currently call «interpreter».  However, it’s been called
     «interpreter» at least since introduced in 1997
     (CPython:a027efa5b(1)).

Each interpreter completely encapsulates all of the non-process-global,
non-thread-specific state needed for the Python runtime to work.
Notably, the interpreter’s state persists between uses.  It includes
fundamental data like *note sys.modules: 17ce.  The runtime ensures
multiple threads using the same interpreter will safely share it between
them.

A Python implementation may support using multiple interpreters at the
same time in the same process.  They are independent and isolated from
one another.  For example, each interpreter has its own *note
sys.modules: 17ce.

For thread-specific runtime state, each interpreter has a set of thread
states, which it manages, in the same way the global runtime contains a
set of interpreters.  It can have thread states for as many host threads
as it needs.  It may even have multiple thread states for the same host
thread, though that isn’t as common.

Each thread state, conceptually, has all the thread-specific runtime
data an interpreter needs to operate in one host thread.  The thread
state includes the current raised exception and the thread’s Python call
stack.  It may include other thread-specific resources.

     Nota: The term «Python thread» can sometimes refer to a thread
     state, but normally it means a thread created using the *note
     threading: f3. module.

Each thread state, over its lifetime, is always tied to exactly one
interpreter and exactly one host thread.  It will only ever be used in
that thread and with that interpreter.

Multiple thread states may be tied to the same host thread, whether for
different interpreters or even the same interpreter.  However, for any
given host thread, only one of the thread states tied to it can be used
by the thread at a time.

Thread states are isolated and independent from one another and don’t
share any data, except for possibly sharing an interpreter and objects
or other resources belonging to that interpreter.

Once a program is running, new Python threads can be created using the
*note threading: f3. module (on platforms and Python implementations
that support threads).  Additional processes can be created using the
*note os: a5, *note subprocess: dc, and *note multiprocessing: 98.
modules.  Interpreters can be created and used with the *note
interpreters: 25. module.  Coroutines (async) can be run using *note
asyncio: b. in each interpreter, typically only in a single thread
(often the main thread).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/commit/a027efa5b


File: python.info,  Node: The import system,  Next: Expressions,  Prev: Execution model,  Up: The Python Language Reference

4.5 The import system
=====================

Python code in one *note module: 19c6. gains access to the code in
another module by the process of *note importing: 2420. it.  The *note
import: 7f9. statement is the most common way of invoking the import
machinery, but it is not the only way.  Functions such as *note
importlib.import_module(): 73d. and built-in *note __import__(): ad3.
can also be used to invoke the import machinery.

The *note import: 7f9. statement combines two operations; it searches
for the named module, then it binds the results of that search to a name
in the local scope.  The search operation of the ‘import’ statement is
defined as a call to the *note __import__(): ad3. function, with the
appropriate arguments.  The return value of *note __import__(): ad3. is
used to perform the name binding operation of the ‘import’ statement.
See the ‘import’ statement for the exact details of that name binding
operation.

A direct call to *note __import__(): ad3. performs only the module
search and, if found, the module creation operation.  While certain
side-effects may occur, such as the importing of parent packages, and
the updating of various caches (including *note sys.modules: 17ce.),
only the *note import: 7f9. statement performs a name binding operation.

When an *note import: 7f9. statement is executed, the standard builtin
*note __import__(): ad3. function is called.  Other mechanisms for
invoking the import system (such as *note importlib.import_module():
73d.) may choose to bypass *note __import__(): ad3. and use their own
solutions to implement import semantics.

When a module is first imported, Python searches for the module and if
found, it creates a module object (1), initializing it.  If the named
module cannot be found, a *note ModuleNotFoundError: d3f. is raised.
Python implements various strategies to search for the named module when
the import machinery is invoked.  These strategies can be modified and
extended by using various hooks described in the sections below.

Cambiato nella versione 3.3: The import system has been updated to fully
implement the second phase of PEP 302(2).  There is no longer any
implicit import machinery - the full import system is exposed through
*note sys.meta_path: f29.  In addition, native namespace package support
has been implemented (see PEP 420(3)).

* Menu:

* importlib: importlib<10>.
* Packages::
* Searching::
* Loading::
* The Path Based Finder::
* Replacing the standard import system::
* Package Relative Imports::
* Special considerations for __main__::
* References::

   ---------- Footnotes ----------

   (1) See *note types.ModuleType: 1016.

   (2) https://peps.python.org/pep-0302/

   (3) https://peps.python.org/pep-0420/


File: python.info,  Node: importlib<10>,  Next: Packages,  Up: The import system

4.5.1 ‘importlib’
-----------------

The *note importlib: 7b. module provides a rich API for interacting with
the import system.  For example *note importlib.import_module(): 73d.
provides a recommended, simpler API than built-in *note __import__():
ad3. for invoking the import machinery.  Refer to the *note importlib:
7b. library documentation for additional detail.


File: python.info,  Node: Packages,  Next: Searching,  Prev: importlib<10>,  Up: The import system

4.5.2 Packages
--------------

Python has only one type of module object, and all modules are of this
type, regardless of whether the module is implemented in Python, C, or
something else.  To help organize modules and provide a naming
hierarchy, Python has a concept of *note packages: 233.

You can think of packages as the directories on a file system and
modules as files within directories, but don’t take this analogy too
literally since packages and modules need not originate from the file
system.  For the purposes of this documentation, we’ll use this
convenient analogy of directories and files.  Like file system
directories, packages are organized hierarchically, and packages may
themselves contain subpackages, as well as regular modules.

It’s important to keep in mind that all packages are modules, but not
all modules are packages.  Or put another way, packages are just a
special kind of module.  Specifically, any module that contains a
‘__path__’ attribute is considered a package.

All modules have a name.  Subpackage names are separated from their
parent package name by a dot, akin to Python’s standard attribute access
syntax.  Thus you might have a package called *note email: 3f, which in
turn has a subpackage called *note email.mime: 49. and a module within
that subpackage called *note email.mime.text: 51.

* Menu:

* Regular packages::
* Namespace packages::


File: python.info,  Node: Regular packages,  Next: Namespace packages,  Up: Packages

4.5.2.1 Regular packages
........................

Python defines two types of packages, *note regular packages: 2424. and
*note namespace packages: 2b2.  Regular packages are traditional
packages as they existed in Python 3.2 and earlier.  A regular package
is typically implemented as a directory containing an ‘__init__.py’
file.  When a regular package is imported, this ‘__init__.py’ file is
implicitly executed, and the objects it defines are bound to names in
the package’s namespace.  The ‘__init__.py’ file can contain the same
Python code that any other module can contain, and Python will add some
additional attributes to the module when it is imported.

For example, the following file system layout defines a top level
‘parent’ package with three subpackages:

     parent/
         __init__.py
         one/
             __init__.py
         two/
             __init__.py
         three/
             __init__.py

Importing ‘parent.one’ will implicitly execute ‘parent/__init__.py’ and
‘parent/one/__init__.py’.  Subsequent imports of ‘parent.two’ or
‘parent.three’ will execute ‘parent/two/__init__.py’ and
‘parent/three/__init__.py’ respectively.


File: python.info,  Node: Namespace packages,  Prev: Regular packages,  Up: Packages

4.5.2.2 Namespace packages
..........................

A namespace package is a composite of various *note portions: 2427,
where each portion contributes a subpackage to the parent package.
Portions may reside in different locations on the file system.  Portions
may also be found in zip files, on the network, or anywhere else that
Python searches during import.  Namespace packages may or may not
correspond directly to objects on the file system; they may be virtual
modules that have no concrete representation.

Namespace packages do not use an ordinary list for their ‘__path__’
attribute.  They instead use a custom iterable type which will
automatically perform a new search for package portions on the next
import attempt within that package if the path of their parent package
(or *note sys.path: 3e4. for a top level package) changes.

With namespace packages, there is no ‘parent/__init__.py’ file.  In
fact, there may be multiple ‘parent’ directories found during import
search, where each one is provided by a different portion.  Thus
‘parent/one’ may not be physically located next to ‘parent/two’.  In
this case, Python will create a namespace package for the top-level
‘parent’ package whenever it or one of its subpackages is imported.

See also PEP 420(1) for the namespace package specification.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0420/


File: python.info,  Node: Searching,  Next: Loading,  Prev: Packages,  Up: The import system

4.5.3 Searching
---------------

To begin the search, Python needs the *note fully qualified: 1d0c. name
of the module (or package, but for the purposes of this discussion, the
difference is immaterial) being imported.  This name may come from
various arguments to the *note import: 7f9. statement, or from the
parameters to the *note importlib.import_module(): 73d. or *note
__import__(): ad3. functions.

This name will be used in various phases of the import search, and it
may be the dotted path to a submodule, e.g.  ‘foo.bar.baz’.  In this
case, Python first tries to import ‘foo’, then ‘foo.bar’, and finally
‘foo.bar.baz’.  If any of the intermediate imports fail, a *note
ModuleNotFoundError: d3f. is raised.

* Menu:

* The module cache::
* Finders and loaders::
* Import hooks::
* The meta path::


File: python.info,  Node: The module cache,  Next: Finders and loaders,  Up: Searching

4.5.3.1 The module cache
........................

The first place checked during import search is *note sys.modules: 17ce.
This mapping serves as a cache of all modules that have been previously
imported, including the intermediate paths.  So if ‘foo.bar.baz’ was
previously imported, *note sys.modules: 17ce. will contain entries for
‘foo’, ‘foo.bar’, and ‘foo.bar.baz’.  Each key will have as its value
the corresponding module object.

During import, the module name is looked up in *note sys.modules: 17ce.
and if present, the associated value is the module satisfying the
import, and the process completes.  However, if the value is ‘None’,
then a *note ModuleNotFoundError: d3f. is raised.  If the module name is
missing, Python will continue searching for the module.

*note sys.modules: 17ce. is writable.  Deleting a key may not destroy
the associated module (as other modules may hold references to it), but
it will invalidate the cache entry for the named module, causing Python
to search anew for the named module upon its next import.  The key can
also be assigned to ‘None’, forcing the next import of the module to
result in a *note ModuleNotFoundError: d3f.

Beware though, as if you keep a reference to the module object,
invalidate its cache entry in *note sys.modules: 17ce, and then
re-import the named module, the two module objects will 'not' be the
same.  By contrast, *note importlib.reload(): 73e. will reuse the 'same'
module object, and simply reinitialise the module contents by rerunning
the module’s code.


File: python.info,  Node: Finders and loaders,  Next: Import hooks,  Prev: The module cache,  Up: Searching

4.5.3.2 Finders and loaders
...........................

If the named module is not found in *note sys.modules: 17ce, then
Python’s import protocol is invoked to find and load the module.  This
protocol consists of two conceptual objects, *note finders: 2351. and
*note loaders: 1a10.  A finder’s job is to determine whether it can find
the named module using whatever strategy it knows about.  Objects that
implement both of these interfaces are referred to as *note importers:
242c. - they return themselves when they find that they can load the
requested module.

Python includes a number of default finders and importers.  The first
one knows how to locate built-in modules, and the second knows how to
locate frozen modules.  A third default finder searches an *note import
path: 242d. for modules.  The *note import path: 242d. is a list of
locations that may name file system paths or zip files.  It can also be
extended to search for any locatable resource, such as those identified
by URLs.

The import machinery is extensible, so new finders can be added to
extend the range and scope of module searching.

Finders do not actually load modules.  If they can find the named
module, they return a 'module spec', an encapsulation of the module’s
import-related information, which the import machinery then uses when
loading the module.

The following sections describe the protocol for finders and loaders in
more detail, including how you can create and register new ones to
extend the import machinery.

Cambiato nella versione 3.4: In previous versions of Python, finders
returned *note loaders: 1a10. directly, whereas now they return module
specs which 'contain' loaders.  Loaders are still used during import but
have fewer responsibilities.


File: python.info,  Node: Import hooks,  Next: The meta path,  Prev: Finders and loaders,  Up: Searching

4.5.3.3 Import hooks
....................

The import machinery is designed to be extensible; the primary mechanism
for this are the 'import hooks'.  There are two types of import hooks:
'meta hooks' and 'import path hooks'.

Meta hooks are called at the start of import processing, before any
other import processing has occurred, other than *note sys.modules:
17ce. cache look up.  This allows meta hooks to override *note sys.path:
3e4. processing, frozen modules, or even built-in modules.  Meta hooks
are registered by adding new finder objects to *note sys.meta_path: f29,
as described below.

Import path hooks are called as part of *note sys.path: 3e4. (or
‘package.__path__’) processing, at the point where their associated path
item is encountered.  Import path hooks are registered by adding new
callables to *note sys.path_hooks: 1226. as described below.


File: python.info,  Node: The meta path,  Prev: Import hooks,  Up: Searching

4.5.3.4 The meta path
.....................

When the named module is not found in *note sys.modules: 17ce, Python
next searches *note sys.meta_path: f29, which contains a list of meta
path finder objects.  These finders are queried in order to see if they
know how to handle the named module.  Meta path finders must implement a
method called *note find_spec(): a6a. which takes three arguments: a
name, an import path, and (optionally) a target module.  The meta path
finder can use any strategy it wants to determine whether it can handle
the named module or not.

If the meta path finder knows how to handle the named module, it returns
a spec object.  If it cannot handle the named module, it returns ‘None’.
If *note sys.meta_path: f29. processing reaches the end of its list
without returning a spec, then a *note ModuleNotFoundError: d3f. is
raised.  Any other exceptions raised are simply propagated up, aborting
the import process.

The *note find_spec(): a6a. method of meta path finders is called with
two or three arguments.  The first is the fully qualified name of the
module being imported, for example ‘foo.bar.baz’.  The second argument
is the path entries to use for the module search.  For top-level
modules, the second argument is ‘None’, but for submodules or
subpackages, the second argument is the value of the parent package’s
‘__path__’ attribute.  If the appropriate ‘__path__’ attribute cannot be
accessed, a *note ModuleNotFoundError: d3f. is raised.  The third
argument is an existing module object that will be the target of loading
later.  The import system passes in a target module only during reload.

The meta path may be traversed multiple times for a single import
request.  For example, assuming none of the modules involved has already
been cached, importing ‘foo.bar.baz’ will first perform a top level
import, calling ‘mpf.find_spec("foo", None, None)’ on each meta path
finder (‘mpf’).  After ‘foo’ has been imported, ‘foo.bar’ will be
imported by traversing the meta path a second time, calling
‘mpf.find_spec("foo.bar", foo.__path__, None)’.  Once ‘foo.bar’ has been
imported, the final traversal will call ‘mpf.find_spec("foo.bar.baz",
foo.bar.__path__, None)’.

Some meta path finders only support top level imports.  These importers
will always return ‘None’ when anything other than ‘None’ is passed as
the second argument.

Python’s default *note sys.meta_path: f29. has three meta path finders,
one that knows how to import built-in modules, one that knows how to
import frozen modules, and one that knows how to import modules from an
*note import path: 242d. (i.e.  the *note path based finder: 2430.).

Cambiato nella versione 3.4: The *note find_spec(): a6a. method of meta
path finders replaced ‘find_module()’, which is now deprecated.  While
it will continue to work without change, the import machinery will try
it only if the finder does not implement *note find_spec(): a6a.

Cambiato nella versione 3.10: Use of ‘find_module()’ by the import
system now raises *note ImportWarning: 71f.

Cambiato nella versione 3.12: ‘find_module()’ has been removed.  Use
*note find_spec(): a6a. instead.


File: python.info,  Node: Loading,  Next: The Path Based Finder,  Prev: Searching,  Up: The import system

4.5.4 Loading
-------------

If and when a module spec is found, the import machinery will use it
(and the loader it contains) when loading the module.  Here is an
approximation of what happens during the loading portion of import:

     module = None
     if spec.loader is not None and hasattr(spec.loader, 'create_module'):
         # It is assumed 'exec_module' will also be defined on the loader.
         module = spec.loader.create_module(spec)
     if module is None:
         module = ModuleType(spec.name)
     # The import-related module attributes get set here:
     _init_module_attrs(spec, module)

     if spec.loader is None:
         # unsupported
         raise ImportError
     if spec.origin is None and spec.submodule_search_locations is not None:
         # namespace package
         sys.modules[spec.name] = module
     elif not hasattr(spec.loader, 'exec_module'):
         module = spec.loader.load_module(spec.name)
     else:
         sys.modules[spec.name] = module
         try:
             spec.loader.exec_module(module)
         except BaseException:
             try:
                 del sys.modules[spec.name]
             except KeyError:
                 pass
             raise
     return sys.modules[spec.name]

Note the following details:

   * If there is an existing module object with the given name in *note
     sys.modules: 17ce, import will have already returned it.

   * The module will exist in *note sys.modules: 17ce. before the loader
     executes the module code.  This is crucial because the module code
     may (directly or indirectly) import itself; adding it to *note
     sys.modules: 17ce. beforehand prevents unbounded recursion in the
     worst case and multiple loading in the best.

   * If loading fails, the failing module – and only the failing module
     – gets removed from *note sys.modules: 17ce.  Any module already in
     the *note sys.modules: 17ce. cache, and any module that was
     successfully loaded as a side-effect, must remain in the cache.
     This contrasts with reloading where even the failing module is left
     in *note sys.modules: 17ce.

   * After the module is created but before execution, the import
     machinery sets the import-related module attributes
     («_init_module_attrs» in the pseudo-code example above), as
     summarized in a *note later section: 2348.

   * Module execution is the key moment of loading in which the module’s
     namespace gets populated.  Execution is entirely delegated to the
     loader, which gets to decide what gets populated and how.

   * The module created during loading and passed to exec_module() may
     not be the one returned at the end of import (1).

Cambiato nella versione 3.4: The import system has taken over the
boilerplate responsibilities of loaders.  These were previously
performed by the *note importlib.abc.Loader.load_module(): a6b. method.

* Menu:

* Loaders::
* Submodules::
* Module specs::
* __path__ attributes on modules::
* Module reprs::
* Cached bytecode invalidation::

   ---------- Footnotes ----------

   (1) The importlib implementation avoids using the return value
directly.  Instead, it gets the module object by looking the module name
up in *note sys.modules: 17ce.  The indirect effect of this is that an
imported module may replace itself in *note sys.modules: 17ce.  This is
implementation-specific behavior that is not guaranteed to work in other
Python implementations.


File: python.info,  Node: Loaders,  Next: Submodules,  Up: Loading

4.5.4.1 Loaders
...............

Module loaders provide the critical function of loading: module
execution.  The import machinery calls the *note
importlib.abc.Loader.exec_module(): a6c. method with a single argument,
the module object to execute.  Any value returned from *note
exec_module(): a6c. is ignored.

Loaders must satisfy the following requirements:

   * If the module is a Python module (as opposed to a built-in module
     or a dynamically loaded extension), the loader should execute the
     module’s code in the module’s global name space
     (‘module.__dict__’).

   * If the loader cannot execute the module, it should raise an *note
     ImportError: 65b, although any other exception raised during *note
     exec_module(): a6c. will be propagated.

In many cases, the finder and loader can be the same object; in such
cases the *note find_spec(): a6a. method would just return a spec with
the loader set to ‘self’.

Module loaders may opt in to creating the module object during loading
by implementing a *note create_module(): eae. method.  It takes one
argument, the module spec, and returns the new module object to use
during loading.  ‘create_module()’ does not need to set any attributes
on the module object.  If the method returns ‘None’, the import
machinery will create the new module itself.

Added in version 3.4: The *note create_module(): eae. method of loaders.

Cambiato nella versione 3.4: The *note load_module(): a6b. method was
replaced by *note exec_module(): a6c. and the import machinery assumed
all the boilerplate responsibilities of loading.

For compatibility with existing loaders, the import machinery will use
the ‘load_module()’ method of loaders if it exists and the loader does
not also implement ‘exec_module()’.  However, ‘load_module()’ has been
deprecated and loaders should implement ‘exec_module()’ instead.

The ‘load_module()’ method must implement all the boilerplate loading
functionality described above in addition to executing the module.  All
the same constraints apply, with some additional clarification:

   * If there is an existing module object with the given name in *note
     sys.modules: 17ce, the loader must use that existing module.
     (Otherwise, *note importlib.reload(): 73e. will not work
     correctly.)  If the named module does not exist in *note
     sys.modules: 17ce, the loader must create a new module object and
     add it to *note sys.modules: 17ce.

   * The module 'must' exist in *note sys.modules: 17ce. before the
     loader executes the module code, to prevent unbounded recursion or
     multiple loading.

   * If loading fails, the loader must remove any modules it has
     inserted into *note sys.modules: 17ce, but it must remove 'only'
     the failing module(s), and only if the loader itself has loaded the
     module(s) explicitly.

Cambiato nella versione 3.5: A *note DeprecationWarning: 1a3. is raised
when ‘exec_module()’ is defined but ‘create_module()’ is not.

Cambiato nella versione 3.6: An *note ImportError: 65b. is raised when
‘exec_module()’ is defined but ‘create_module()’ is not.

Cambiato nella versione 3.10: Use of ‘load_module()’ will raise *note
ImportWarning: 71f.


File: python.info,  Node: Submodules,  Next: Module specs,  Prev: Loaders,  Up: Loading

4.5.4.2 Submodules
..................

When a submodule is loaded using any mechanism (e.g.  ‘importlib’ APIs,
the ‘import’ or ‘import-from’ statements, or built-in ‘__import__()’) a
binding is placed in the parent module’s namespace to the submodule
object.  For example, if package ‘spam’ has a submodule ‘foo’, after
importing ‘spam.foo’, ‘spam’ will have an attribute ‘foo’ which is bound
to the submodule.  Let’s say you have the following directory structure:

     spam/
         __init__.py
         foo.py

and ‘spam/__init__.py’ has the following line in it:

     from .foo import Foo

then executing the following puts name bindings for ‘foo’ and ‘Foo’ in
the ‘spam’ module:

     >>> import spam
     >>> spam.foo
     <module 'spam.foo' from '/tmp/imports/spam/foo.py'>
     >>> spam.Foo
     <class 'spam.foo.Foo'>

Given Python’s familiar name binding rules this might seem surprising,
but it’s actually a fundamental feature of the import system.  The
invariant holding is that if you have ‘sys.modules['spam']’ and
‘sys.modules['spam.foo']’ (as you would after the above import), the
latter must appear as the ‘foo’ attribute of the former.


File: python.info,  Node: Module specs,  Next: __path__ attributes on modules,  Prev: Submodules,  Up: Loading

4.5.4.3 Module specs
....................

The import machinery uses a variety of information about each module
during import, especially before loading.  Most of the information is
common to all modules.  The purpose of a module’s spec is to encapsulate
this import-related information on a per-module basis.

Using a spec during import allows state to be transferred between import
system components, e.g.  between the finder that creates the module spec
and the loader that executes it.  Most importantly, it allows the import
machinery to perform the boilerplate operations of loading, whereas
without a module spec the loader had that responsibility.

The module’s spec is exposed as *note module.__spec__: 234b.  Setting
‘__spec__’ appropriately applies equally to *note modules initialized
during interpreter startup: 2435.  The one exception is ‘__main__’,
where ‘__spec__’ is *note set to None in some cases: 2436.

See *note ModuleSpec: 2255. for details on the contents of the module
spec.

Added in version 3.4.


File: python.info,  Node: __path__ attributes on modules,  Next: Module reprs,  Prev: Module specs,  Up: Loading

4.5.4.4 __path__ attributes on modules
......................................

The *note __path__: 203e. attribute should be a (possibly empty) *note
sequence: 717. of strings enumerating the locations where the package’s
submodules will be found.  By definition, if a module has a ‘__path__’
attribute, it is a *note package: 233.

A package’s *note __path__: 203e. attribute is used during imports of
its subpackages.  Within the import machinery, it functions much the
same as *note sys.path: 3e4, i.e.  providing a list of locations to
search for modules during import.  However, ‘__path__’ is typically much
more constrained than ‘sys.path’.

The same rules used for *note sys.path: 3e4. also apply to a package’s
‘__path__’.  *note sys.path_hooks: 1226. (described below) are consulted
when traversing a package’s ‘__path__’.

A package’s ‘__init__.py’ file may set or alter the package’s *note
__path__: 203e. attribute, and this was typically the way namespace
packages were implemented prior to PEP 420(1).  With the adoption of PEP
420(2), namespace packages no longer need to supply ‘__init__.py’ files
containing only ‘__path__’ manipulation code; the import machinery
automatically sets ‘__path__’ correctly for the namespace package.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0420/

   (2) https://peps.python.org/pep-0420/


File: python.info,  Node: Module reprs,  Next: Cached bytecode invalidation,  Prev: __path__ attributes on modules,  Up: Loading

4.5.4.5 Module reprs
....................

By default, all modules have a usable repr, however depending on the
attributes set above, and in the module’s spec, you can more explicitly
control the repr of module objects.

If the module has a spec (‘__spec__’), the import machinery will try to
generate a repr from it.  If that fails or there is no spec, the import
system will craft a default repr using whatever information is available
on the module.  It will try to use the ‘module.__name__’,
‘module.__file__’, and ‘module.__loader__’ as input into the repr, with
defaults for whatever information is missing.

Here are the exact rules used:

   * If the module has a ‘__spec__’ attribute, the information in the
     spec is used to generate the repr.  The «name», «loader», «origin»,
     and «has_location» attributes are consulted.

   * If the module has a ‘__file__’ attribute, this is used as part of
     the module’s repr.

   * If the module has no ‘__file__’ but does have a ‘__loader__’ that
     is not ‘None’, then the loader’s repr is used as part of the
     module’s repr.

   * Otherwise, just use the module’s ‘__name__’ in the repr.

Cambiato nella versione 3.12: Use of ‘module_repr()’, having been
deprecated since Python 3.4, was removed in Python 3.12 and is no longer
called during the resolution of a module’s repr.


File: python.info,  Node: Cached bytecode invalidation,  Prev: Module reprs,  Up: Loading

4.5.4.6 Cached bytecode invalidation
....................................

Before Python loads cached bytecode from a ‘.pyc’ file, it checks
whether the cache is up-to-date with the source ‘.py’ file.  By default,
Python does this by storing the source’s last-modified timestamp and
size in the cache file when writing it.  At runtime, the import system
then validates the cache file by checking the stored metadata in the
cache file against the source’s metadata.

Python also supports «hash-based» cache files, which store a hash of the
source file’s contents rather than its metadata.  There are two variants
of hash-based ‘.pyc’ files: checked and unchecked.  For checked
hash-based ‘.pyc’ files, Python validates the cache file by hashing the
source file and comparing the resulting hash with the hash in the cache
file.  If a checked hash-based cache file is found to be invalid, Python
regenerates it and writes a new checked hash-based cache file.  For
unchecked hash-based ‘.pyc’ files, Python simply assumes the cache file
is valid if it exists.  Hash-based ‘.pyc’ files validation behavior may
be overridden with the *note -check-hash-based-pycs: 210b. flag.

Cambiato nella versione 3.7: Added hash-based ‘.pyc’ files.  Previously,
Python only supported timestamp-based invalidation of bytecode caches.


File: python.info,  Node: The Path Based Finder,  Next: Replacing the standard import system,  Prev: Loading,  Up: The import system

4.5.5 The Path Based Finder
---------------------------

As mentioned previously, Python comes with several default meta path
finders.  One of these, called the *note path based finder: 2430. (*note
PathFinder: 1225.), searches an *note import path: 242d, which contains
a list of *note path entries: 243b.  Each path entry names a location to
search for modules.

The path based finder itself doesn’t know how to import anything.
Instead, it traverses the individual path entries, associating each of
them with a path entry finder that knows how to handle that particular
kind of path.

The default set of path entry finders implement all the semantics for
finding modules on the file system, handling special file types such as
Python source code (‘.py’ files), Python byte code (‘.pyc’ files) and
shared libraries (e.g.  ‘.so’ files).  When supported by the *note
zipimport: 138. module in the standard library, the default path entry
finders also handle loading all of these file types (other than shared
libraries) from zipfiles.

Path entries need not be limited to file system locations.  They can
refer to URLs, database queries, or any other location that can be
specified as a string.

The path based finder provides additional hooks and protocols so that
you can extend and customize the types of searchable path entries.  For
example, if you wanted to support path entries as network URLs, you
could write a hook that implements HTTP semantics to find modules on the
web.  This hook (a callable) would return a *note path entry finder:
1273. supporting the protocol described below, which was then used to
get a loader for the module from the web.

A word of warning: this section and the previous both use the term
'finder', distinguishing between them by using the terms *note meta path
finder: 1272. and *note path entry finder: 1273.  These two types of
finders are very similar, support similar protocols, and function in
similar ways during the import process, but it’s important to keep in
mind that they are subtly different.  In particular, meta path finders
operate at the beginning of the import process, as keyed off the *note
sys.meta_path: f29. traversal.

By contrast, path entry finders are in a sense an implementation detail
of the path based finder, and in fact, if the path based finder were to
be removed from *note sys.meta_path: f29, none of the path entry finder
semantics would be invoked.

* Menu:

* Path entry finders::
* Path entry finder protocol::


File: python.info,  Node: Path entry finders,  Next: Path entry finder protocol,  Up: The Path Based Finder

4.5.5.1 Path entry finders
..........................

The *note path based finder: 2430. is responsible for finding and
loading Python modules and packages whose location is specified with a
string *note path entry: 243b.  Most path entries name locations in the
file system, but they need not be limited to this.

As a meta path finder, the *note path based finder: 2430. implements the
*note find_spec(): a6a. protocol previously described, however it
exposes additional hooks that can be used to customize how modules are
found and loaded from the *note import path: 242d.

Three variables are used by the *note path based finder: 2430, *note
sys.path: 3e4, *note sys.path_hooks: 1226. and *note
sys.path_importer_cache: 7fb.  The ‘__path__’ attributes on package
objects are also used.  These provide additional ways that the import
machinery can be customized.

*note sys.path: 3e4. contains a list of strings providing search
locations for modules and packages.  It is initialized from the *note
PYTHONPATH: 121f. environment variable and various other installation-
and implementation-specific defaults.  Entries in *note sys.path: 3e4.
can name directories on the file system, zip files, and potentially
other «locations» (see the *note site: cc. module) that should be
searched for modules, such as URLs, or database queries.  Only strings
should be present on *note sys.path: 3e4.; all other data types are
ignored.

The *note path based finder: 2430. is a *note meta path finder: 1272, so
the import machinery begins the *note import path: 242d. search by
calling the path based finder’s *note find_spec(): 1213. method as
described previously.  When the ‘path’ argument to *note find_spec():
1213. is given, it will be a list of string paths to traverse -
typically a package’s ‘__path__’ attribute for an import within that
package.  If the ‘path’ argument is ‘None’, this indicates a top level
import and *note sys.path: 3e4. is used.

The path based finder iterates over every entry in the search path, and
for each of these, looks for an appropriate *note path entry finder:
1273. (*note PathEntryFinder: a71.) for the path entry.  Because this
can be an expensive operation (e.g.  there may be ‘stat()’ call
overheads for this search), the path based finder maintains a cache
mapping path entries to path entry finders.  This cache is maintained in
*note sys.path_importer_cache: 7fb. (despite the name, this cache
actually stores finder objects rather than being limited to *note
importer: 242c. objects).  In this way, the expensive search for a
particular *note path entry: 243b. location’s *note path entry finder:
1273. need only be done once.  User code is free to remove cache entries
from *note sys.path_importer_cache: 7fb. forcing the path based finder
to perform the path entry search again.

If the path entry is not present in the cache, the path based finder
iterates over every callable in *note sys.path_hooks: 1226.  Each of the
*note path entry hooks: 243d. in this list is called with a single
argument, the path entry to be searched.  This callable may either
return a *note path entry finder: 1273. that can handle the path entry,
or it may raise *note ImportError: 65b.  An *note ImportError: 65b. is
used by the path based finder to signal that the hook cannot find a
*note path entry finder: 1273. for that *note path entry: 243b.  The
exception is ignored and *note import path: 242d. iteration continues.
The hook should expect either a string or bytes object; the encoding of
bytes objects is up to the hook (e.g.  it may be a file system encoding,
UTF-8, or something else), and if the hook cannot decode the argument,
it should raise *note ImportError: 65b.

If *note sys.path_hooks: 1226. iteration ends with no *note path entry
finder: 1273. being returned, then the path based finder’s *note
find_spec(): 1213. method will store ‘None’ in *note
sys.path_importer_cache: 7fb. (to indicate that there is no finder for
this path entry) and return ‘None’, indicating that this *note meta path
finder: 1272. could not find the module.

If a *note path entry finder: 1273. 'is' returned by one of the *note
path entry hook: 243d. callables on *note sys.path_hooks: 1226, then the
following protocol is used to ask the finder for a module spec, which is
then used when loading the module.

The current working directory – denoted by an empty string – is handled
slightly differently from other entries on *note sys.path: 3e4.  First,
if the current working directory cannot be determined or is found not to
exist, no value is stored in *note sys.path_importer_cache: 7fb.
Second, the value for the current working directory is looked up fresh
for each module lookup.  Third, the path used for *note
sys.path_importer_cache: 7fb. and returned by *note
importlib.machinery.PathFinder.find_spec(): 1213. will be the actual
current working directory and not the empty string.


File: python.info,  Node: Path entry finder protocol,  Prev: Path entry finders,  Up: The Path Based Finder

4.5.5.2 Path entry finder protocol
..................................

In order to support imports of modules and initialized packages and also
to contribute portions to namespace packages, path entry finders must
implement the *note find_spec(): a6e. method.

*note find_spec(): a6e. takes two arguments: the fully qualified name of
the module being imported, and the (optional) target module.
‘find_spec()’ returns a fully populated spec for the module.  This spec
will always have «loader» set (with one exception).

To indicate to the import machinery that the spec represents a namespace
*note portion: 2427, the path entry finder sets
‘submodule_search_locations’ to a list containing the portion.

Cambiato nella versione 3.4: *note find_spec(): a6e. replaced
‘find_loader()’ and ‘find_module()’, both of which are now deprecated,
but will be used if ‘find_spec()’ is not defined.

Older path entry finders may implement one of these two deprecated
methods instead of ‘find_spec()’.  The methods are still respected for
the sake of backward compatibility.  However, if ‘find_spec()’ is
implemented on the path entry finder, the legacy methods are ignored.

‘find_loader()’ takes one argument, the fully qualified name of the
module being imported.  ‘find_loader()’ returns a 2-tuple where the
first item is the loader and the second item is a namespace *note
portion: 2427.

For backwards compatibility with other implementations of the import
protocol, many path entry finders also support the same, traditional
‘find_module()’ method that meta path finders support.  However path
entry finder ‘find_module()’ methods are never called with a ‘path’
argument (they are expected to record the appropriate path information
from the initial call to the path hook).

The ‘find_module()’ method on path entry finders is deprecated, as it
does not allow the path entry finder to contribute portions to namespace
packages.  If both ‘find_loader()’ and ‘find_module()’ exist on a path
entry finder, the import system will always call ‘find_loader()’ in
preference to ‘find_module()’.

Cambiato nella versione 3.10: Calls to ‘find_module()’ and
‘find_loader()’ by the import system will raise *note ImportWarning:
71f.

Cambiato nella versione 3.12: ‘find_module()’ and ‘find_loader()’ have
been removed.


File: python.info,  Node: Replacing the standard import system,  Next: Package Relative Imports,  Prev: The Path Based Finder,  Up: The import system

4.5.6 Replacing the standard import system
------------------------------------------

The most reliable mechanism for replacing the entire import system is to
delete the default contents of *note sys.meta_path: f29, replacing them
entirely with a custom meta path hook.

If it is acceptable to only alter the behaviour of import statements
without affecting other APIs that access the import system, then
replacing the builtin *note __import__(): ad3. function may be
sufficient.

To selectively prevent the import of some modules from a hook early on
the meta path (rather than disabling the standard import system
entirely), it is sufficient to raise *note ModuleNotFoundError: d3f.
directly from *note find_spec(): a6a. instead of returning ‘None’.  The
latter indicates that the meta path search should continue, while
raising an exception terminates it immediately.


File: python.info,  Node: Package Relative Imports,  Next: Special considerations for __main__,  Prev: Replacing the standard import system,  Up: The import system

4.5.7 Package Relative Imports
------------------------------

Relative imports use leading dots.  A single leading dot indicates a
relative import, starting with the current package.  Two or more leading
dots indicate a relative import to the parent(s) of the current package,
one level per dot after the first.  For example, given the following
package layout:

     package/
         __init__.py
         subpackage1/
             __init__.py
             moduleX.py
             moduleY.py
         subpackage2/
             __init__.py
             moduleZ.py
         moduleA.py

In either ‘subpackage1/moduleX.py’ or ‘subpackage1/__init__.py’, the
following are valid relative imports:

     from .moduleY import spam
     from .moduleY import spam as ham
     from . import moduleY
     from ..subpackage1 import moduleY
     from ..subpackage2.moduleZ import eggs
     from ..moduleA import foo

Absolute imports may use either the ‘import <>’ or ‘from <> import <>’
syntax, but relative imports may only use the second form; the reason
for this is that:

     import XXX.YYY.ZZZ

should expose ‘XXX.YYY.ZZZ’ as a usable expression, but .moduleY is not
a valid expression.


File: python.info,  Node: Special considerations for __main__,  Next: References,  Prev: Package Relative Imports,  Up: The import system

4.5.8 Special considerations for __main__
-----------------------------------------

The *note __main__: 1. module is a special case relative to Python’s
import system.  As noted *note elsewhere: 2435, the ‘__main__’ module is
directly initialized at interpreter startup, much like *note sys: df.
and *note builtins: 13.  However, unlike those two, it doesn’t strictly
qualify as a built-in module.  This is because the manner in which
‘__main__’ is initialized depends on the flags and other options with
which the interpreter is invoked.

* Menu:

* __main__.__spec__: __main__ __spec__.


File: python.info,  Node: __main__ __spec__,  Up: Special considerations for __main__

4.5.8.1 __main__.__spec__
.........................

Depending on how *note __main__: 1. is initialized, ‘__main__.__spec__’
gets set appropriately or to ‘None’.

When Python is started with the *note -m: 23c. option, ‘__spec__’ is set
to the module spec of the corresponding module or package.  ‘__spec__’
is also populated when the ‘__main__’ module is loaded as part of
executing a directory, zipfile or other *note sys.path: 3e4. entry.

In *note the remaining cases: 2104. ‘__main__.__spec__’ is set to
‘None’, as the code used to populate the *note __main__: 1. does not
correspond directly with an importable module:

   - interactive prompt

   - *note -c: 1a8. option

   - running from stdin

   - running directly from a source or bytecode file

Note that ‘__main__.__spec__’ is always ‘None’ in the last case, 'even
if' the file could technically be imported directly as a module instead.
Use the *note -m: 23c. switch if valid module metadata is desired in
*note __main__: 1.

Note also that even when ‘__main__’ corresponds with an importable
module and ‘__main__.__spec__’ is set accordingly, they’re still
considered 'distinct' modules.  This is due to the fact that blocks
guarded by ‘if __name__ == "__main__":’ checks only execute when the
module is used to populate the ‘__main__’ namespace, and not during
normal import.


File: python.info,  Node: References,  Prev: Special considerations for __main__,  Up: The import system

4.5.9 References
----------------

The import machinery has evolved considerably since Python’s early days.
The original specification for packages(1) is still available to read,
although some details have changed since the writing of that document.

The original specification for *note sys.meta_path: f29. was PEP 302(2),
with subsequent extension in PEP 420(3).

PEP 420(4) introduced *note namespace packages: 2b2. for Python 3.3.
PEP 420(5) also introduced the ‘find_loader()’ protocol as an
alternative to ‘find_module()’.

PEP 366(6) describes the addition of the ‘__package__’ attribute for
explicit relative imports in main modules.

PEP 328(7) introduced absolute and explicit relative imports and
initially proposed ‘__name__’ for semantics PEP 366(8) would eventually
specify for ‘__package__’.

PEP 338(9) defines executing modules as scripts.

PEP 451(10) adds the encapsulation of per-module import state in spec
objects.  It also off-loads most of the boilerplate responsibilities of
loaders back onto the import machinery.  These changes allow the
deprecation of several APIs in the import system and also addition of
new methods to finders and loaders.

   ---------- Footnotes ----------

   (1) https://www.python.org/doc/essays/packages/

   (2) https://peps.python.org/pep-0302/

   (3) https://peps.python.org/pep-0420/

   (4) https://peps.python.org/pep-0420/

   (5) https://peps.python.org/pep-0420/

   (6) https://peps.python.org/pep-0366/

   (7) https://peps.python.org/pep-0328/

   (8) https://peps.python.org/pep-0366/

   (9) https://peps.python.org/pep-0338/

   (10) https://peps.python.org/pep-0451/


File: python.info,  Node: Expressions,  Next: Simple statements,  Prev: The import system,  Up: The Python Language Reference

4.6 Expressions
===============

This chapter explains the meaning of the elements of expressions in
Python.

'Syntax Notes:' In this and the following chapters, extended BNF
notation will be used to describe syntax, not lexical analysis.  When
(one alternative of) a syntax rule has the form

     name: othername

and no semantics are given, the semantics of this form of ‘name’ are the
same as for ‘othername’.

* Menu:

* Arithmetic conversions::
* Atoms::
* Primaries::
* Await expression::
* The power operator::
* Unary arithmetic and bitwise operations::
* Binary arithmetic operations::
* Shifting operations::
* Binary bitwise operations::
* Comparisons::
* Boolean operations::
* Assignment expressions: Assignment expressions<2>.
* Conditional expressions::
* Lambdas::
* Expression lists::
* Evaluation order::
* Operator precedence::


File: python.info,  Node: Arithmetic conversions,  Next: Atoms,  Up: Expressions

4.6.1 Arithmetic conversions
----------------------------

When a description of an arithmetic operator below uses the phrase «the
numeric arguments are converted to a common real type», this means that
the operator implementation for built-in types works as follows:

   * If both arguments are complex numbers, no conversion is performed;

   * if either argument is a complex or a floating-point number, the
     other is converted to a floating-point number;

   * otherwise, both must be integers and no conversion is necessary.

Some additional rules apply for certain operators (e.g., a string as a
left argument to the “%” operator).  Extensions must define their own
conversion behavior.


File: python.info,  Node: Atoms,  Next: Primaries,  Prev: Arithmetic conversions,  Up: Expressions

4.6.2 Atoms
-----------

Atoms are the most basic elements of expressions.  The simplest atoms
are identifiers or literals.  Forms enclosed in parentheses, brackets or
braces are also categorized syntactically as atoms.  The syntax for
atoms is:

     atom:      *note identifier: 22aa. | *note literal: 244f. | *note enclosure: 2450.
     enclosure: *note parenth_form: 2451. | *note list_display: 2452. | *note dict_display: 2453. | *note set_display: 2454.
                | *note generator_expression: 2455. | *note yield_atom: 2456.

* Menu:

* Identifiers (Names): Identifiers Names.
* Literals: Literals<2>.
* Parenthesized forms::
* Displays for lists, sets and dictionaries: Displays for lists sets and dictionaries.
* List displays::
* Set displays::
* Dictionary displays::
* Generator expressions::
* Yield expressions::


File: python.info,  Node: Identifiers Names,  Next: Literals<2>,  Up: Atoms

4.6.2.1 Identifiers (Names)
...........................

An identifier occurring as an atom is a name.  See section *note Names
(identifiers and keywords): 2289. for lexical definition and section
*note Naming and binding: 232d. for documentation of naming and binding.

When the name is bound to an object, evaluation of the atom yields that
object.  When a name is not bound, an attempt to evaluate it raises a
*note NameError: 452. exception.

* Menu:

* Private name mangling::


File: python.info,  Node: Private name mangling,  Up: Identifiers Names

4.6.2.2 Private name mangling
.............................

When an identifier that textually occurs in a class definition begins
with two or more underscore characters and does not end in two or more
underscores, it is considered a 'private name' of that class.

Vedi anche
..........

The *note class specifications: 14df.

More precisely, private names are transformed to a longer form before
code is generated for them.  If the transformed name is longer than 255
characters, implementation-defined truncation may happen.

The transformation is independent of the syntactical context in which
the identifier is used but only the following private identifiers are
mangled:

   - Any name used as the name of a variable that is assigned or read or
     any name of an attribute being accessed.

     The *note __name__: 1268. attribute of nested functions, classes,
     and type aliases is however not mangled.

   - The name of imported modules, e.g., ‘__spam’ in ‘import __spam’.
     If the module is part of a package (i.e., its name contains a dot),
     the name is 'not' mangled, e.g., the ‘__foo’ in ‘import __foo.bar’
     is not mangled.

   - The name of an imported member, e.g., ‘__f’ in ‘from spam import
     __f’.

The transformation rule is defined as follows:

   - The class name, with leading underscores removed and a single
     leading underscore inserted, is inserted in front of the
     identifier, e.g., the identifier ‘__spam’ occurring in a class
     named ‘Foo’, ‘_Foo’ or ‘__Foo’ is transformed to ‘_Foo__spam’.

   - If the class name consists only of underscores, the transformation
     is the identity, e.g., the identifier ‘__spam’ occurring in a class
     named ‘_’ or ‘__’ is left as is.


File: python.info,  Node: Literals<2>,  Next: Parenthesized forms,  Prev: Identifiers Names,  Up: Atoms

4.6.2.3 Literals
................

Python supports string and bytes literals and various numeric literals:

     literal: *note strings: 245b. | *note NUMBER: 22ef.

Evaluation of a literal yields an object of the given type (string,
bytes, integer, floating-point number, complex number) with the given
value.  The value may be approximated in the case of floating-point and
imaginary (complex) literals.  See section *note Literals: 22b2. for
details.  See section *note String literal concatenation: 22c9. for
details on ‘strings’.

All literals correspond to immutable data types, and hence the object’s
identity is less important than its value.  Multiple evaluations of
literals with the same value (either the same occurrence in the program
text or a different occurrence) may obtain the same object or a
different object with the same value.

* Menu:

* String literal concatenation::


File: python.info,  Node: String literal concatenation,  Up: Literals<2>

4.6.2.4 String literal concatenation
....................................

Multiple adjacent string or bytes literals (delimited by whitespace),
possibly using different quoting conventions, are allowed, and their
meaning is the same as their concatenation:

     >>> "hello" 'world'
     "helloworld"

Formally:

     strings: ( *note STRING: 22ba. | *note fstring: 22dd.)+ | *note tstring: 22ed.+

This feature is defined at the syntactical level, so it only works with
literals.  To concatenate string expressions at run time, the “+”
operator may be used:

     >>> greeting = "Hello"
     >>> space = " "
     >>> name = "Blaise"
     >>> print(greeting + space + name)   # not: print(greeting space name)
     Hello Blaise

Literal concatenation can freely mix raw strings, triple-quoted strings,
and formatted string literals.  For example:

     >>> "Hello" r', ' f"{name}!"
     "Hello, Blaise!"

This feature can be used to reduce the number of backslashes needed, to
split long strings conveniently across long lines, or even to add
comments to parts of strings.  For example:

     re.compile("[A-Za-z_]"       # letter or underscore
                "[A-Za-z0-9_]*"   # letter, digit or underscore
               )

However, bytes literals may only be combined with other byte literals;
not with string literals of any kind.  Also, template string literals
may only be combined with other template string literals:

     >>> t"Hello" t"{name}!"
     Template(strings=('Hello', '!'), interpolations=(...))


File: python.info,  Node: Parenthesized forms,  Next: Displays for lists sets and dictionaries,  Prev: Literals<2>,  Up: Atoms

4.6.2.5 Parenthesized forms
...........................

A parenthesized form is an optional expression list enclosed in
parentheses:

     parenth_form: "(" [*note starred_expression: 245f.] ")"

A parenthesized expression list yields whatever that expression list
yields: if the list contains at least one comma, it yields a tuple;
otherwise, it yields the single expression that makes up the expression
list.

An empty pair of parentheses yields an empty tuple object.  Since tuples
are immutable, the same rules as for literals apply (i.e., two
occurrences of the empty tuple may or may not yield the same object).

Note that tuples are not formed by the parentheses, but rather by use of
the comma.  The exception is the empty tuple, for which parentheses
'are' required — allowing unparenthesized «nothing» in expressions would
cause ambiguities and allow common typos to pass uncaught.


File: python.info,  Node: Displays for lists sets and dictionaries,  Next: List displays,  Prev: Parenthesized forms,  Up: Atoms

4.6.2.6 Displays for lists, sets and dictionaries
.................................................

For constructing a list, a set or a dictionary Python provides special
syntax called «displays», each of them in two flavors:

   * either the container contents are listed explicitly, or

   * they are computed via a set of looping and filtering instructions,
     called a 'comprehension'.

Common syntax elements for comprehensions are:

     comprehension: *note assignment_expression: 2411. *note comp_for: 2462.
     comp_for:      ["async"] "for" *note target_list: 2463. "in" *note or_test: 2464. [*note comp_iter: 2465.]
     comp_iter:     *note comp_for: 2462. | *note comp_if: 2466.
     comp_if:       "if" *note or_test: 2464. [*note comp_iter: 2465.]

The comprehension consists of a single expression followed by at least
one ‘for’ clause and zero or more ‘for’ or ‘if’ clauses.  In this case,
the elements of the new container are those that would be produced by
considering each of the ‘for’ or ‘if’ clauses a block, nesting from left
to right, and evaluating the expression to produce an element each time
the innermost block is reached.

However, aside from the iterable expression in the leftmost ‘for’
clause, the comprehension is executed in a separate implicitly nested
scope.  This ensures that names assigned to in the target list don’t
«leak» into the enclosing scope.

The iterable expression in the leftmost ‘for’ clause is evaluated
directly in the enclosing scope and then passed as an argument to the
implicitly nested scope.  Subsequent ‘for’ clauses and any filter
condition in the leftmost ‘for’ clause cannot be evaluated in the
enclosing scope as they may depend on the values obtained from the
leftmost iterable.  For example: ‘[x*y for x in range(10) for y in
range(x, x+10)]’.

To ensure the comprehension always results in a container of the
appropriate type, ‘yield’ and ‘yield from’ expressions are prohibited in
the implicitly nested scope.

Since Python 3.6, in an *note async def: 7ee. function, an ‘async for’
clause may be used to iterate over a *note asynchronous iterator: 4c8.
A comprehension in an ‘async def’ function may consist of either a ‘for’
or ‘async for’ clause following the leading expression, may contain
additional ‘for’ or ‘async for’ clauses, and may also use *note await:
18d. expressions.

If a comprehension contains ‘async for’ clauses, or if it contains
‘await’ expressions or other asynchronous comprehensions anywhere except
the iterable expression in the leftmost ‘for’ clause, it is called an
'asynchronous comprehension'.  An asynchronous comprehension may suspend
the execution of the coroutine function in which it appears.  See also
PEP 530(1).

Added in version 3.6: Asynchronous comprehensions were introduced.

Cambiato nella versione 3.8: ‘yield’ and ‘yield from’ prohibited in the
implicitly nested scope.

Cambiato nella versione 3.11: Asynchronous comprehensions are now
allowed inside comprehensions in asynchronous functions.  Outer
comprehensions implicitly become asynchronous.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0530/


File: python.info,  Node: List displays,  Next: Set displays,  Prev: Displays for lists sets and dictionaries,  Up: Atoms

4.6.2.7 List displays
.....................

A list display is a possibly empty series of expressions enclosed in
square brackets:

     list_display: "[" [*note flexible_expression_list: 2469. | *note comprehension: 2461.] "]"

A list display yields a new list object, the contents being specified by
either a list of expressions or a comprehension.  When a comma-separated
list of expressions is supplied, its elements are evaluated from left to
right and placed into the list object in that order.  When a
comprehension is supplied, the list is constructed from the elements
resulting from the comprehension.


File: python.info,  Node: Set displays,  Next: Dictionary displays,  Prev: List displays,  Up: Atoms

4.6.2.8 Set displays
....................

A set display is denoted by curly braces and distinguishable from
dictionary displays by the lack of colons separating keys and values:

     set_display: "{" (*note flexible_expression_list: 2469. | *note comprehension: 2461.) "}"

A set display yields a new mutable set object, the contents being
specified by either a sequence of expressions or a comprehension.  When
a comma-separated list of expressions is supplied, its elements are
evaluated from left to right and added to the set object.  When a
comprehension is supplied, the set is constructed from the elements
resulting from the comprehension.

An empty set cannot be constructed with ‘{}’; this literal constructs an
empty dictionary.


File: python.info,  Node: Dictionary displays,  Next: Generator expressions,  Prev: Set displays,  Up: Atoms

4.6.2.9 Dictionary displays
...........................

A dictionary display is a possibly empty series of dict items (key/value
pairs) enclosed in curly braces:

     dict_display:       "{" [*note dict_item_list: 246d. | *note dict_comprehension: 246e.] "}"
     dict_item_list:     *note dict_item: 246f. ("," *note dict_item: 246f.)* [","]
     dict_item:          *note expression: 182. ":" *note expression: 182. | "**" *note or_expr: 22eb.
     dict_comprehension: *note expression: 182. ":" *note expression: 182. *note comp_for: 2462.

A dictionary display yields a new dictionary object.

If a comma-separated sequence of dict items is given, they are evaluated
from left to right to define the entries of the dictionary: each key
object is used as a key into the dictionary to store the corresponding
value.  This means that you can specify the same key multiple times in
the dict item list, and the final dictionary’s value for that key will
be the last one given.

A double asterisk ‘**’ denotes 'dictionary unpacking'.  Its operand must
be a *note mapping: 13c3.  Each mapping item is added to the new
dictionary.  Later values replace values already set by earlier dict
items and earlier dictionary unpackings.

Added in version 3.5: Unpacking into dictionary displays, originally
proposed by PEP 448(1).

A dict comprehension, in contrast to list and set comprehensions, needs
two expressions separated with a colon followed by the usual «for» and
«if» clauses.  When the comprehension is run, the resulting key and
value elements are inserted in the new dictionary in the order they are
produced.

Restrictions on the types of the key values are listed earlier in
section *note The standard type hierarchy: 2318.  (To summarize, the key
type should be *note hashable: 825, which excludes all mutable objects.)
Clashes between duplicate keys are not detected; the last value
(textually rightmost in the display) stored for a given key value
prevails.

Cambiato nella versione 3.8: Prior to Python 3.8, in dict
comprehensions, the evaluation order of key and value was not
well-defined.  In CPython, the value was evaluated before the key.
Starting with 3.8, the key is evaluated before the value, as proposed by
PEP 572(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0448/

   (2) https://peps.python.org/pep-0572/


File: python.info,  Node: Generator expressions,  Next: Yield expressions,  Prev: Dictionary displays,  Up: Atoms

4.6.2.10 Generator expressions
..............................

A generator expression is a compact generator notation in parentheses:

     generator_expression: "(" *note expression: 182. *note comp_for: 2462. ")"

A generator expression yields a new generator object.  Its syntax is the
same as for comprehensions, except that it is enclosed in parentheses
instead of brackets or curly braces.

Variables used in the generator expression are evaluated lazily when the
*note __next__(): 2098. method is called for the generator object (in
the same fashion as normal generators).  However, the iterable
expression in the leftmost ‘for’ clause is immediately evaluated, and
the *note iterator: 4c9. is immediately created for that iterable, so
that an error produced while creating the iterator will be emitted at
the point where the generator expression is defined, rather than at the
point where the first value is retrieved.  Subsequent ‘for’ clauses and
any filter condition in the leftmost ‘for’ clause cannot be evaluated in
the enclosing scope as they may depend on the values obtained from the
leftmost iterable.  For example: ‘(x*y for x in range(10) for y in
range(x, x+10))’.

The parentheses can be omitted on calls with only one argument.  See
section *note Calls: f7f. for details.

To avoid interfering with the expected operation of the generator
expression itself, ‘yield’ and ‘yield from’ expressions are prohibited
in the implicitly defined generator.

If a generator expression contains either ‘async for’ clauses or *note
await: 18d. expressions it is called an 'asynchronous generator
expression'.  An asynchronous generator expression returns a new
asynchronous generator object, which is an asynchronous iterator (see
*note Asynchronous Iterators: f79.).

Added in version 3.6: Asynchronous generator expressions were
introduced.

Cambiato nella versione 3.7: Prior to Python 3.7, asynchronous generator
expressions could only appear in *note async def: 7ee. coroutines.
Starting with 3.7, any function can use asynchronous generator
expressions.

Cambiato nella versione 3.8: ‘yield’ and ‘yield from’ prohibited in the
implicitly nested scope.


File: python.info,  Node: Yield expressions,  Prev: Generator expressions,  Up: Atoms

4.6.2.11 Yield expressions
..........................

     yield_atom:       "(" *note yield_expression: 22ec. ")"
     yield_from:       "yield" "from" *note expression: 182.
     yield_expression: "yield" *note yield_list: 2475. | *note yield_from: 2474.

The yield expression is used when defining a *note generator: 1263.
function or an *note asynchronous generator: 2476. function and thus can
only be used in the body of a function definition.  Using a yield
expression in a function’s body causes that function to be a generator
function, and using it in an *note async def: 7ee. function’s body
causes that coroutine function to be an asynchronous generator function.
For example:

     def gen():  # defines a generator function
         yield 123

     async def agen(): # defines an asynchronous generator function
         yield 123

Due to their side effects on the containing scope, ‘yield’ expressions
are not permitted as part of the implicitly defined scopes used to
implement comprehensions and generator expressions.

Cambiato nella versione 3.8: Yield expressions prohibited in the
implicitly nested scopes used to implement comprehensions and generator
expressions.

Generator functions are described below, while asynchronous generator
functions are described separately in section *note Asynchronous
generator functions: 2477.

When a generator function is called, it returns an iterator known as a
generator.  That generator then controls the execution of the generator
function.  The execution starts when one of the generator’s methods is
called.  At that time, the execution proceeds to the first yield
expression, where it is suspended again, returning the value of *note
yield_list: 2475. to the generator’s caller, or ‘None’ if *note
yield_list: 2475. is omitted.  By suspended, we mean that all local
state is retained, including the current bindings of local variables,
the instruction pointer, the internal evaluation stack, and the state of
any exception handling.  When the execution is resumed by calling one of
the generator’s methods, the function can proceed exactly as if the
yield expression were just another external call.  The value of the
yield expression after resuming depends on the method which resumed the
execution.  If *note __next__(): 2098. is used (typically via either a
*note for: 34a. or the *note next(): 9da. builtin) then the result is
*note None: 886.  Otherwise, if *note send(): 23fd. is used, then the
result will be the value passed in to that method.

All of this makes generator functions quite similar to coroutines; they
yield multiple times, they have more than one entry point and their
execution can be suspended.  The only difference is that a generator
function cannot control where the execution should continue after it
yields; the control is always transferred to the generator’s caller.

Yield expressions are allowed anywhere in a *note try: 8f9. construct.
If the generator is not resumed before it is finalized (by reaching a
zero reference count or by being garbage collected), the
generator-iterator’s *note close(): 177b. method will be called,
allowing any pending *note finally: 1b0. clauses to execute.

When ‘yield from <expr>’ is used, the supplied expression must be an
iterable.  The values produced by iterating that iterable are passed
directly to the caller of the current generator’s methods.  Any values
passed in with *note send(): 23fd. and any exceptions passed in with
*note throw(): 71d. are passed to the underlying iterator if it has the
appropriate methods.  If this is not the case, then *note send(): 23fd.
will raise *note AttributeError: 5f0. or *note TypeError: 198, while
*note throw(): 71d. will just raise the passed in exception immediately.

When the underlying iterator is complete, the *note value: 23fa.
attribute of the raised *note StopIteration: df7. instance becomes the
value of the yield expression.  It can be either set explicitly when
raising *note StopIteration: df7, or automatically when the subiterator
is a generator (by returning a value from the subgenerator).

Cambiato nella versione 3.3: Added ‘yield from <expr>’ to delegate
control flow to a subiterator.

The parentheses may be omitted when the yield expression is the sole
expression on the right hand side of an assignment statement.

Vedi anche
..........

PEP 255(1) - Simple Generators

     The proposal for adding generators and the *note yield: bc4.
     statement to Python.

PEP 342(2) - Coroutines via Enhanced Generators

     The proposal to enhance the API and syntax of generators, making
     them usable as simple coroutines.

PEP 380(3) - Syntax for Delegating to a Subgenerator

     The proposal to introduce the *note yield_from: 2474. syntax,
     making delegation to subgenerators easy.

PEP 525(4) - Asynchronous Generators

     The proposal that expanded on PEP 492(5) by adding generator
     capabilities to coroutine functions.

* Menu:

* Generator-iterator methods::
* Examples::
* Asynchronous generator functions: Asynchronous generator functions<2>.
* Asynchronous generator-iterator methods::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0255/

   (2) https://peps.python.org/pep-0342/

   (3) https://peps.python.org/pep-0380/

   (4) https://peps.python.org/pep-0525/

   (5) https://peps.python.org/pep-0492/


File: python.info,  Node: Generator-iterator methods,  Next: Examples,  Up: Yield expressions

4.6.2.12 Generator-iterator methods
...................................

This subsection describes the methods of a generator iterator.  They can
be used to control the execution of a generator function.

Note that calling any of the generator methods below when the generator
is already executing raises a *note ValueError: 2ec. exception.

 -- Metodo: generator.__next__ ()

     Starts the execution of a generator function or resumes it at the
     last executed yield expression.  When a generator function is
     resumed with a *note __next__(): 2098. method, the current yield
     expression always evaluates to *note None: 886.  The execution then
     continues to the next yield expression, where the generator is
     suspended again, and the value of the *note yield_list: 2475. is
     returned to *note __next__(): 2098.”s caller.  If the generator
     exits without yielding another value, a *note StopIteration: df7.
     exception is raised.

     This method is normally called implicitly, e.g.  by a *note for:
     34a. loop, or by the built-in *note next(): 9da. function.

 -- Metodo: generator.send (value)

     Resumes the execution and «sends» a value into the generator
     function.  The 'value' argument becomes the result of the current
     yield expression.  The *note send(): 23fd. method returns the next
     value yielded by the generator, or raises *note StopIteration: df7.
     if the generator exits without yielding another value.  When *note
     send(): 23fd. is called to start the generator, it must be called
     with *note None: 886. as the argument, because there is no yield
     expression that could receive the value.

 -- Metodo: generator.throw (value)

 -- Metodo: generator.throw (type[, value[, traceback]])

     Raises an exception at the point where the generator was paused,
     and returns the next value yielded by the generator function.  If
     the generator exits without yielding another value, a *note
     StopIteration: df7. exception is raised.  If the generator function
     does not catch the passed-in exception, or raises a different
     exception, then that exception propagates to the caller.

     In typical use, this is called with a single exception instance
     similar to the way the *note raise: 804. keyword is used.

     For backwards compatibility, however, the second signature is
     supported, following a convention from older versions of Python.
     The 'type' argument should be an exception class, and 'value'
     should be an exception instance.  If the 'value' is not provided,
     the 'type' constructor is called to get an instance.  If
     'traceback' is provided, it is set on the exception, otherwise any
     existing *note __traceback__: 14ce. attribute stored in 'value' may
     be cleared.

     Cambiato nella versione 3.12: The second signature (type[, value[,
     traceback]]) is deprecated and may be removed in a future version
     of Python.

 -- Metodo: generator.close ()

     Raises a *note GeneratorExit: 15cf. exception at the point where
     the generator function was paused (equivalent to calling
     ‘throw(GeneratorExit)’).  The exception is raised by the yield
     expression where the generator was paused.  If the generator
     function catches the exception and returns a value, this value is
     returned from *note close(): 177b.  If the generator function is
     already closed, or raises *note GeneratorExit: 15cf. (by not
     catching the exception), *note close(): 177b. returns *note None:
     886.  If the generator yields a value, a *note RuntimeError: 244.
     is raised.  If the generator raises any other exception, it is
     propagated to the caller.  If the generator has already exited due
     to an exception or normal exit, *note close(): 177b. returns *note
     None: 886. and has no other effect.

     Cambiato nella versione 3.13: If a generator returns a value upon
     being closed, the value is returned by *note close(): 177b.


File: python.info,  Node: Examples,  Next: Asynchronous generator functions<2>,  Prev: Generator-iterator methods,  Up: Yield expressions

4.6.2.13 Examples
.................

Here is a simple example that demonstrates the behavior of generators
and generator functions:

     >>> def echo(value=None):
     ...     print("Execution starts when 'next()' is called for the first time.")
     ...     try:
     ...         while True:
     ...             try:
     ...                 value = (yield value)
     ...             except Exception as e:
     ...                 value = e
     ...     finally:
     ...         print("Don't forget to clean up when 'close()' is called.")
     ...
     >>> generator = echo(1)
     >>> print(next(generator))
     Execution starts when 'next()' is called for the first time.
     1
     >>> print(next(generator))
     None
     >>> print(generator.send(2))
     2
     >>> generator.throw(TypeError, "spam")
     TypeError('spam',)
     >>> generator.close()
     Don't forget to clean up when 'close()' is called.

For examples using ‘yield from’, see *note PEP 380; Syntax for
Delegating to a Subgenerator: 123c. in «What’s New in Python.»


File: python.info,  Node: Asynchronous generator functions<2>,  Next: Asynchronous generator-iterator methods,  Prev: Examples,  Up: Yield expressions

4.6.2.14 Asynchronous generator functions
.........................................

The presence of a yield expression in a function or method defined using
*note async def: 7ee. further defines the function as an *note
asynchronous generator: 2476. function.

When an asynchronous generator function is called, it returns an
asynchronous iterator known as an asynchronous generator object.  That
object then controls the execution of the generator function.  An
asynchronous generator object is typically used in an *note async for:
ca3. statement in a coroutine function analogously to how a generator
object would be used in a *note for: 34a. statement.

Calling one of the asynchronous generator’s methods returns an *note
awaitable: 4ca. object, and the execution starts when this object is
awaited on.  At that time, the execution proceeds to the first yield
expression, where it is suspended again, returning the value of *note
yield_list: 2475. to the awaiting coroutine.  As with a generator,
suspension means that all local state is retained, including the current
bindings of local variables, the instruction pointer, the internal
evaluation stack, and the state of any exception handling.  When the
execution is resumed by awaiting on the next object returned by the
asynchronous generator’s methods, the function can proceed exactly as if
the yield expression were just another external call.  The value of the
yield expression after resuming depends on the method which resumed the
execution.  If *note __anext__(): 247b. is used then the result is *note
None: 886.  Otherwise, if *note asend(): ad8. is used, then the result
will be the value passed in to that method.

If an asynchronous generator happens to exit early by *note break: 17f,
the caller task being cancelled, or other exceptions, the generator’s
async cleanup code will run and possibly raise exceptions or access
context variables in an unexpected context–perhaps after the lifetime of
tasks it depends, or during the event loop shutdown when the
async-generator garbage collection hook is called.  To prevent this, the
caller must explicitly close the async generator by calling *note
aclose(): ad7. method to finalize the generator and ultimately detach it
from the event loop.

In an asynchronous generator function, yield expressions are allowed
anywhere in a *note try: 8f9. construct.  However, if an asynchronous
generator is not resumed before it is finalized (by reaching a zero
reference count or by being garbage collected), then a yield expression
within a ‘try’ construct could result in a failure to execute pending
*note finally: 1b0. clauses.  In this case, it is the responsibility of
the event loop or scheduler running the asynchronous generator to call
the asynchronous generator-iterator’s *note aclose(): ad7. method and
run the resulting coroutine object, thus allowing any pending ‘finally’
clauses to execute.

To take care of finalization upon event loop termination, an event loop
should define a 'finalizer' function which takes an asynchronous
generator-iterator and presumably calls *note aclose(): ad7. and
executes the coroutine.  This 'finalizer' may be registered by calling
*note sys.set_asyncgen_hooks(): 1985.  When first iterated over, an
asynchronous generator-iterator will store the registered 'finalizer' to
be called upon finalization.  For a reference example of a 'finalizer'
method see the implementation of ‘asyncio.Loop.shutdown_asyncgens’ in
Lib/asyncio/base_events.py(1).

The expression ‘yield from <expr>’ is a syntax error when used in an
asynchronous generator function.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/base_events.py


File: python.info,  Node: Asynchronous generator-iterator methods,  Prev: Asynchronous generator functions<2>,  Up: Yield expressions

4.6.2.15 Asynchronous generator-iterator methods
................................................

This subsection describes the methods of an asynchronous generator
iterator, which are used to control the execution of a generator
function.

 -- Metodo: async agen.__anext__ ()

     Returns an awaitable which when run starts to execute the
     asynchronous generator or resumes it at the last executed yield
     expression.  When an asynchronous generator function is resumed
     with an *note __anext__(): 247b. method, the current yield
     expression always evaluates to *note None: 886. in the returned
     awaitable, which when run will continue to the next yield
     expression.  The value of the *note yield_list: 2475. of the yield
     expression is the value of the *note StopIteration: df7. exception
     raised by the completing coroutine.  If the asynchronous generator
     exits without yielding another value, the awaitable instead raises
     a *note StopAsyncIteration: 1df7. exception, signalling that the
     asynchronous iteration has completed.

     This method is normally called implicitly by a *note async for:
     ca3. loop.

 -- Metodo: async agen.asend (value)

     Returns an awaitable which when run resumes the execution of the
     asynchronous generator.  As with the *note send(): 23fd. method for
     a generator, this «sends» a value into the asynchronous generator
     function, and the 'value' argument becomes the result of the
     current yield expression.  The awaitable returned by the *note
     asend(): ad8. method will return the next value yielded by the
     generator as the value of the raised *note StopIteration: df7, or
     raises *note StopAsyncIteration: 1df7. if the asynchronous
     generator exits without yielding another value.  When *note
     asend(): ad8. is called to start the asynchronous generator, it
     must be called with *note None: 886. as the argument, because there
     is no yield expression that could receive the value.

 -- Metodo: async agen.athrow (value)

 -- Metodo: async agen.athrow (type[, value[, traceback]])

     Returns an awaitable that raises an exception of type ‘type’ at the
     point where the asynchronous generator was paused, and returns the
     next value yielded by the generator function as the value of the
     raised *note StopIteration: df7. exception.  If the asynchronous
     generator exits without yielding another value, a *note
     StopAsyncIteration: 1df7. exception is raised by the awaitable.  If
     the generator function does not catch the passed-in exception, or
     raises a different exception, then when the awaitable is run that
     exception propagates to the caller of the awaitable.

     Cambiato nella versione 3.12: The second signature (type[, value[,
     traceback]]) is deprecated and may be removed in a future version
     of Python.

 -- Metodo: async agen.aclose ()

     Returns an awaitable that when run will throw a *note
     GeneratorExit: 15cf. into the asynchronous generator function at
     the point where it was paused.  If the asynchronous generator
     function then exits gracefully, is already closed, or raises *note
     GeneratorExit: 15cf. (by not catching the exception), then the
     returned awaitable will raise a *note StopIteration: df7.
     exception.  Any further awaitables returned by subsequent calls to
     the asynchronous generator will raise a *note StopAsyncIteration:
     1df7. exception.  If the asynchronous generator yields a value, a
     *note RuntimeError: 244. is raised by the awaitable.  If the
     asynchronous generator raises any other exception, it is propagated
     to the caller of the awaitable.  If the asynchronous generator has
     already exited due to an exception or normal exit, then further
     calls to *note aclose(): ad7. will return an awaitable that does
     nothing.


File: python.info,  Node: Primaries,  Next: Await expression,  Prev: Atoms,  Up: Expressions

4.6.3 Primaries
---------------

Primaries represent the most tightly bound operations of the language.
Their syntax is:

     primary: *note atom: 244e. | *note attributeref: 2481. | *note subscription: 2482. | *note slicing: 2483. | *note call: 2484.

* Menu:

* Attribute references::
* Subscriptions::
* Slicings::
* Calls::


File: python.info,  Node: Attribute references,  Next: Subscriptions,  Up: Primaries

4.6.3.1 Attribute references
............................

An attribute reference is a primary followed by a period and a name:

     attributeref: *note primary: 2480. "." *note identifier: 22aa.

The primary must evaluate to an object of a type that supports attribute
references, which most objects do.  This object is then asked to produce
the attribute whose name is the identifier.  The type and value produced
is determined by the object.  Multiple evaluations of the same attribute
reference may yield different objects.

This production can be customized by overriding the *note
__getattribute__(): dcd. method or the *note __getattr__(): 6fb. method.
The ‘__getattribute__()’ method is called first and either returns a
value or raises *note AttributeError: 5f0. if the attribute is not
available.

If an *note AttributeError: 5f0. is raised and the object has a
‘__getattr__()’ method, that method is called as a fallback.


File: python.info,  Node: Subscriptions,  Next: Slicings,  Prev: Attribute references,  Up: Primaries

4.6.3.2 Subscriptions
.....................

The subscription of an instance of a *note container class: 23ba. will
generally select an element from the container.  The subscription of a
*note generic class: 1a1. will generally return a *note GenericAlias:
8c2. object.

     subscription: *note primary: 2480. "[" *note flexible_expression_list: 2469. "]"

When an object is subscripted, the interpreter will evaluate the primary
and the expression list.

The primary must evaluate to an object that supports subscription.  An
object may support subscription through defining one or both of *note
__getitem__(): 588. and *note __class_getitem__(): 944.  When the
primary is subscripted, the evaluated result of the expression list will
be passed to one of these methods.  For more details on when
‘__class_getitem__’ is called instead of ‘__getitem__’, see *note
__class_getitem__ versus __getitem__: 23b3.

If the expression list contains at least one comma, or if any of the
expressions are starred, the expression list will evaluate to a *note
tuple: 614. containing the items of the expression list.  Otherwise, the
expression list will evaluate to the value of the list’s sole member.

Cambiato nella versione 3.11: Expressions in an expression list may be
starred.  See PEP 646(1).

For built-in objects, there are two types of objects that support
subscription via *note __getitem__(): 588.:

  1. Mappings.  If the primary is a *note mapping: 13c3, the expression
     list must evaluate to an object whose value is one of the keys of
     the mapping, and the subscription selects the value in the mapping
     that corresponds to that key.  An example of a builtin mapping
     class is the *note dict: 183. class.

  2. Sequences.  If the primary is a *note sequence: 717, the expression
     list must evaluate to an *note int: 19b. or a *note slice: 695. (as
     discussed in the following section).  Examples of builtin sequence
     classes include the *note str: 169, *note list: 24d. and *note
     tuple: 614. classes.

The formal syntax makes no special provision for negative indices in
*note sequences: 717.  However, built-in sequences all provide a *note
__getitem__(): 588. method that interprets negative indices by adding
the length of the sequence to the index so that, for example, ‘x[-1]’
selects the last item of ‘x’.  The resulting value must be a nonnegative
integer less than the number of items in the sequence, and the
subscription selects the item whose index is that value (counting from
zero).  Since the support for negative indices and slicing occurs in the
object’s *note __getitem__(): 588. method, subclasses overriding this
method will need to explicitly add that support.

A *note string: 169. is a special kind of sequence whose items are
'characters'.  A character is not a separate data type but a string of
exactly one character.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0646/


File: python.info,  Node: Slicings,  Next: Calls,  Prev: Subscriptions,  Up: Primaries

4.6.3.3 Slicings
................

A slicing selects a range of items in a sequence object (e.g., a string,
tuple or list).  Slicings may be used as expressions or as targets in
assignment or *note del: 1b07. statements.  The syntax for a slicing:

     slicing:      *note primary: 2480. "[" *note slice_list: 248a. "]"
     slice_list:   *note slice_item: 248b. ("," *note slice_item: 248b.)* [","]
     slice_item:   *note expression: 182. | *note proper_slice: 248c.
     proper_slice: [*note lower_bound: 248d.] ":" [*note upper_bound: 248e.] [ ":" [*note stride: 248f.] ]
     lower_bound:  *note expression: 182.
     upper_bound:  *note expression: 182.
     stride:       *note expression: 182.

There is ambiguity in the formal syntax here: anything that looks like
an expression list also looks like a slice list, so any subscription can
be interpreted as a slicing.  Rather than further complicating the
syntax, this is disambiguated by defining that in this case the
interpretation as a subscription takes priority over the interpretation
as a slicing (this is the case if the slice list contains no proper
slice).

The semantics for a slicing are as follows.  The primary is indexed
(using the same *note __getitem__(): 588. method as normal subscription)
with a key that is constructed from the slice list, as follows.  If the
slice list contains at least one comma, the key is a tuple containing
the conversion of the slice items; otherwise, the conversion of the lone
slice item is the key.  The conversion of a slice item that is an
expression is that expression.  The conversion of a proper slice is a
slice object (see section *note The standard type hierarchy: 2318.)
whose *note start: 238b, *note stop: 238c. and *note step: 238d.
attributes are the values of the expressions given as lower bound, upper
bound and stride, respectively, substituting ‘None’ for missing
expressions.


File: python.info,  Node: Calls,  Prev: Slicings,  Up: Primaries

4.6.3.4 Calls
.............

A call calls a callable object (e.g., a *note function: 2491.) with a
possibly empty series of *note arguments: 67b.:

     call:                 *note primary: 2480. "(" [*note argument_list: 2492. [","] | *note comprehension: 2461.] ")"
     argument_list:        *note positional_arguments: 2493. ["," *note starred_and_keywords: 2494.]
                             ["," *note keywords_arguments: 2495.]
                           | *note starred_and_keywords: 2494. ["," *note keywords_arguments: 2495.]
                           | *note keywords_arguments: 2495.
     positional_arguments: *note positional_item: 2496. ("," *note positional_item: 2496.)*
     positional_item:      *note assignment_expression: 2411. | "*" *note expression: 182.
     starred_and_keywords: ("*" *note expression: 182. | *note keyword_item: 2497.)
                           ("," "*" *note expression: 182. | "," *note keyword_item: 2497.)*
     keywords_arguments:   (*note keyword_item: 2497. | "**" *note expression: 182.)
                           ("," *note keyword_item: 2497. | "," "**" *note expression: 182.)*
     keyword_item:         *note identifier: 22aa. "=" *note expression: 182.

An optional trailing comma may be present after the positional and
keyword arguments but does not affect the semantics.

The primary must evaluate to a callable object (user-defined functions,
built-in functions, methods of built-in objects, class objects, methods
of class instances, and all objects having a *note __call__(): 77b.
method are callable).  All argument expressions are evaluated before the
call is attempted.  Please refer to section *note Function definitions:
2002. for the syntax of formal *note parameter: 2332. lists.

If keyword arguments are present, they are first converted to positional
arguments, as follows.  First, a list of unfilled slots is created for
the formal parameters.  If there are N positional arguments, they are
placed in the first N slots.  Next, for each keyword argument, the
identifier is used to determine the corresponding slot (if the
identifier is the same as the first formal parameter name, the first
slot is used, and so on).  If the slot is already filled, a *note
TypeError: 198. exception is raised.  Otherwise, the argument is placed
in the slot, filling it (even if the expression is ‘None’, it fills the
slot).  When all arguments have been processed, the slots that are still
unfilled are filled with the corresponding default value from the
function definition.  (Default values are calculated, once, when the
function is defined; thus, a mutable object such as a list or dictionary
used as default value will be shared by all calls that don’t specify an
argument value for the corresponding slot; this should usually be
avoided.)  If there are any unfilled slots for which no default value is
specified, a *note TypeError: 198. exception is raised.  Otherwise, the
list of filled slots is used as the argument list for the call.

'Dettaglio dell’implementazione di CPython:' An implementation may
provide built-in functions whose positional parameters do not have
names, even if they are “named” for the purpose of documentation, and
which therefore cannot be supplied by keyword.  In CPython, this is the
case for functions implemented in C that use *note PyArg_ParseTuple():
3c1. to parse their arguments.

If there are more positional arguments than there are formal parameter
slots, a *note TypeError: 198. exception is raised, unless a formal
parameter using the syntax ‘*identifier’ is present; in this case, that
formal parameter receives a tuple containing the excess positional
arguments (or an empty tuple if there were no excess positional
arguments).

If any keyword argument does not correspond to a formal parameter name,
a *note TypeError: 198. exception is raised, unless a formal parameter
using the syntax ‘**identifier’ is present; in this case, that formal
parameter receives a dictionary containing the excess keyword arguments
(using the keywords as keys and the argument values as corresponding
values), or a (new) empty dictionary if there were no excess keyword
arguments.

If the syntax ‘*expression’ appears in the function call, ‘expression’
must evaluate to an *note iterable: 142f.  Elements from these iterables
are treated as if they were additional positional arguments.  For the
call ‘f(x1, x2, *y, x3, x4)’, if 'y' evaluates to a sequence 'y1', …,
'yM', this is equivalent to a call with M+4 positional arguments 'x1',
'x2', 'y1', …, 'yM', 'x3', 'x4'.

A consequence of this is that although the ‘*expression’ syntax may
appear 'after' explicit keyword arguments, it is processed 'before' the
keyword arguments (and any ‘**expression’ arguments – see below).  So:

     >>> def f(a, b):
     ...     print(a, b)
     ...
     >>> f(b=1, *(2,))
     2 1
     >>> f(a=1, *(2,))
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: f() got multiple values for keyword argument 'a'
     >>> f(1, *(2,))
     1 2

It is unusual for both keyword arguments and the ‘*expression’ syntax to
be used in the same call, so in practice this confusion does not often
arise.

If the syntax ‘**expression’ appears in the function call, ‘expression’
must evaluate to a *note mapping: 13c3, the contents of which are
treated as additional keyword arguments.  If a parameter matching a key
has already been given a value (by an explicit keyword argument, or from
another unpacking), a *note TypeError: 198. exception is raised.

When ‘**expression’ is used, each key in this mapping must be a string.
Each value from the mapping is assigned to the first formal parameter
eligible for keyword assignment whose name is equal to the key.  A key
need not be a Python identifier (e.g.  ‘"max-temp °F"’ is acceptable,
although it will not match any formal parameter that could be declared).
If there is no match to a formal parameter the key-value pair is
collected by the ‘**’ parameter, if there is one, or if there is not, a
*note TypeError: 198. exception is raised.

Formal parameters using the syntax ‘*identifier’ or ‘**identifier’
cannot be used as positional argument slots or as keyword argument
names.

Cambiato nella versione 3.5: Function calls accept any number of ‘*’ and
‘**’ unpackings, positional arguments may follow iterable unpackings
(‘*’), and keyword arguments may follow dictionary unpackings (‘**’).
Originally proposed by PEP 448(1).

A call always returns some value, possibly ‘None’, unless it raises an
exception.  How this value is computed depends on the type of the
callable object.

If it is—

a user-defined function:

     The code block for the function is executed, passing it the
     argument list.  The first thing the code block will do is bind the
     formal parameters to the arguments; this is described in section
     *note Function definitions: 2002.  When the code block executes a
     *note return: 1af. statement, this specifies the return value of
     the function call.  If execution reaches the end of the code block
     without executing a *note return: 1af. statement, the return value
     is ‘None’.

a built-in function or method:

     The result is up to the interpreter; see *note Funzioni
     Incorporate: 1464. for the descriptions of built-in functions and
     methods.

a class object:

     A new instance of that class is returned.

a class instance method:

     The corresponding user-defined function is called, with an argument
     list that is one longer than the argument list of the call: the
     instance becomes the first argument.

a class instance:

     The class must define a *note __call__(): 77b. method; the effect
     is then the same as if that method was called.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0448/


File: python.info,  Node: Await expression,  Next: The power operator,  Prev: Primaries,  Up: Expressions

4.6.4 Await expression
----------------------

Suspend the execution of *note coroutine: 6ba. on an *note awaitable:
4ca. object.  Can only be used inside a *note coroutine function: f75.

     await_expr: "await" *note primary: 2480.

Added in version 3.5.


File: python.info,  Node: The power operator,  Next: Unary arithmetic and bitwise operations,  Prev: Await expression,  Up: Expressions

4.6.5 The power operator
------------------------

The power operator binds more tightly than unary operators on its left;
it binds less tightly than unary operators on its right.  The syntax is:

     power: (*note await_expr: 2499. | *note primary: 2480.) ["**" *note u_expr: 249d.]

Thus, in an unparenthesized sequence of power and unary operators, the
operators are evaluated from right to left (this does not constrain the
evaluation order for the operands): ‘-1**2’ results in ‘-1’.

The power operator has the same semantics as the built-in *note pow():
1a4. function, when called with two arguments: it yields its left
argument raised to the power of its right argument.  The numeric
arguments are first converted to a common type, and the result is of
that type.

For int operands, the result has the same type as the operands unless
the second argument is negative; in that case, all arguments are
converted to float and a float result is delivered.  For example,
‘10**2’ returns ‘100’, but ‘10**-2’ returns ‘0.01’.

Raising ‘0.0’ to a negative power results in a *note ZeroDivisionError:
b41.  Raising a negative number to a fractional power results in a *note
complex: 197. number.  (In earlier versions it raised a *note
ValueError: 2ec.)

This operation can be customized using the special *note __pow__(): 9d6.
and *note __rpow__(): 1a5. methods.


File: python.info,  Node: Unary arithmetic and bitwise operations,  Next: Binary arithmetic operations,  Prev: The power operator,  Up: Expressions

4.6.6 Unary arithmetic and bitwise operations
---------------------------------------------

All unary arithmetic and bitwise operations have the same priority:

     u_expr: *note power: 249c. | "-" *note u_expr: 249d. | "+" *note u_expr: 249d. | "~" *note u_expr: 249d.

The unary ‘-’ (minus) operator yields the negation of its numeric
argument; the operation can be overridden with the *note __neg__():
23e6. special method.

The unary ‘+’ (plus) operator yields its numeric argument unchanged; the
operation can be overridden with the *note __pos__(): 23e7. special
method.

The unary ‘~’ (invert) operator yields the bitwise inversion of its
integer argument.  The bitwise inversion of ‘x’ is defined as ‘-(x+1)’.
It only applies to integral numbers or to custom objects that override
the *note __invert__(): 23e9. special method.

In all three cases, if the argument does not have the proper type, a
*note TypeError: 198. exception is raised.


File: python.info,  Node: Binary arithmetic operations,  Next: Shifting operations,  Prev: Unary arithmetic and bitwise operations,  Up: Expressions

4.6.7 Binary arithmetic operations
----------------------------------

The binary arithmetic operations have the conventional priority levels.
Note that some of these operations also apply to certain non-numeric
types.  Apart from the power operator, there are only two levels, one
for multiplicative operators and one for additive operators:

     m_expr: *note u_expr: 249d. | *note m_expr: 24a2. "*" *note u_expr: 249d. | *note m_expr: 24a2. "@" *note m_expr: 24a2. |
             *note m_expr: 24a2. "//" *note u_expr: 249d. | *note m_expr: 24a2. "/" *note u_expr: 249d. |
             *note m_expr: 24a2. "%" *note u_expr: 249d.
     a_expr: *note m_expr: 24a2. | *note a_expr: 24a3. "+" *note m_expr: 24a2. | *note a_expr: 24a3. "-" *note m_expr: 24a2.

The ‘*’ (multiplication) operator yields the product of its arguments.
The arguments must either both be numbers, or one argument must be an
integer and the other must be a sequence.  In the former case, the
numbers are converted to a common real type and then multiplied
together.  In the latter case, sequence repetition is performed; a
negative repetition factor yields an empty sequence.

This operation can be customized using the special *note __mul__():
23c6. and *note __rmul__(): 23c7. methods.

Cambiato nella versione 3.14: If only one operand is a complex number,
the other operand is converted to a floating-point number.

The ‘@’ (at) operator is intended to be used for matrix multiplication.
No builtin Python types implement this operator.

This operation can be customized using the special *note __matmul__():
f7b. and *note __rmatmul__(): f7c. methods.

Added in version 3.5.

The ‘/’ (division) and ‘//’ (floor division) operators yield the
quotient of their arguments.  The numeric arguments are first converted
to a common type.  Division of integers yields a float, while floor
division of integers results in an integer; the result is that of
mathematical division with the “floor” function applied to the result.
Division by zero raises the *note ZeroDivisionError: b41. exception.

The division operation can be customized using the special *note
__truediv__(): 1092. and *note __rtruediv__(): 23d4. methods.  The floor
division operation can be customized using the special *note
__floordiv__(): 16fb. and *note __rfloordiv__(): 23d5. methods.

The ‘%’ (modulo) operator yields the remainder from the division of the
first argument by the second.  The numeric arguments are first converted
to a common type.  A zero right argument raises the *note
ZeroDivisionError: b41. exception.  The arguments may be floating-point
numbers, e.g., ‘3.14%0.7’ equals ‘0.34’ (since ‘3.14’ equals ‘4*0.7 +
0.34’.)  The modulo operator always yields a result with the same sign
as its second operand (or zero); the absolute value of the result is
strictly smaller than the absolute value of the second operand (1).

The floor division and modulo operators are connected by the following
identity: ‘x == (x//y)*y + (x%y)’.  Floor division and modulo are also
connected with the built-in function *note divmod(): b9b.: ‘divmod(x, y)
== (x//y, x%y)’.  (2).

In addition to performing the modulo operation on numbers, the ‘%’
operator is also overloaded by string objects to perform old-style
string formatting (also known as interpolation).  The syntax for string
formatting is described in the Python Library Reference, section *note
Formattazione delle stringhe in stile printf: 8dc.

The 'modulo' operation can be customized using the special *note
__mod__(): 23cd. and *note __rmod__(): fd7. methods.

The floor division operator, the modulo operator, and the *note
divmod(): b9b. function are not defined for complex numbers.  Instead,
convert to a floating-point number using the *note abs(): 2077. function
if appropriate.

The ‘+’ (addition) operator yields the sum of its arguments.  The
arguments must either both be numbers or both be sequences of the same
type.  In the former case, the numbers are converted to a common real
type and then added together.  In the latter case, the sequences are
concatenated.

This operation can be customized using the special *note __add__():
23c3. and *note __radd__(): 23c4. methods.

Cambiato nella versione 3.14: If only one operand is a complex number,
the other operand is converted to a floating-point number.

The ‘-’ (subtraction) operator yields the difference of its arguments.
The numeric arguments are first converted to a common real type.

This operation can be customized using the special *note __sub__():
23cc. and *note __rsub__(): 23d3. methods.

Cambiato nella versione 3.14: If only one operand is a complex number,
the other operand is converted to a floating-point number.

   ---------- Footnotes ----------

   (1) While ‘abs(x%y) < abs(y)’ is true mathematically, for floats it
may not be true numerically due to roundoff.  For example, and assuming
a platform on which a Python float is an IEEE 754 double-precision
number, in order that ‘-1e-100 % 1e100’ have the same sign as ‘1e100’,
the computed result is ‘-1e-100 + 1e100’, which is numerically exactly
equal to ‘1e100’.  The function *note math.fmod(): 24a4. returns a
result whose sign matches the sign of the first argument instead, and so
returns ‘-1e-100’ in this case.  Which approach is more appropriate
depends on the application.

   (2) If x is very close to an exact integer multiple of y, it’s
possible for ‘x//y’ to be one larger than ‘(x-x%y)//y’ due to rounding.
In such cases, Python returns the latter result, in order to preserve
that ‘divmod(x,y)[0] * y + x % y’ be very close to ‘x’.


File: python.info,  Node: Shifting operations,  Next: Binary bitwise operations,  Prev: Binary arithmetic operations,  Up: Expressions

4.6.8 Shifting operations
-------------------------

The shifting operations have lower priority than the arithmetic
operations:

     shift_expr: *note a_expr: 24a3. | *note shift_expr: 24a7. ("<<" | ">>") *note a_expr: 24a3.

These operators accept integers as arguments.  They shift the first
argument to the left or right by the number of bits given by the second
argument.

The left shift operation can be customized using the special *note
__lshift__(): 23ce. and *note __rlshift__(): 23d7. methods.  The right
shift operation can be customized using the special *note __rshift__():
23cf. and *note __rrshift__(): 23d8. methods.

A right shift by 'n' bits is defined as floor division by ‘pow(2,n)’.  A
left shift by 'n' bits is defined as multiplication with ‘pow(2,n)’.


File: python.info,  Node: Binary bitwise operations,  Next: Comparisons,  Prev: Shifting operations,  Up: Expressions

4.6.9 Binary bitwise operations
-------------------------------

Each of the three bitwise operations has a different priority level:

     and_expr: *note shift_expr: 24a7. | *note and_expr: 24aa. "&" *note shift_expr: 24a7.
     xor_expr: *note and_expr: 24aa. | *note xor_expr: 24ab. "^" *note and_expr: 24aa.
     or_expr:  *note xor_expr: 24ab. | *note or_expr: 22eb. "|" *note xor_expr: 24ab.

The ‘&’ operator yields the bitwise AND of its arguments, which must be
integers or one of them must be a custom object overriding *note
__and__(): 23d0. or *note __rand__(): 23d9. special methods.

The ‘^’ operator yields the bitwise XOR (exclusive OR) of its arguments,
which must be integers or one of them must be a custom object overriding
*note __xor__(): 23d1. or *note __rxor__(): 23da. special methods.

The ‘|’ operator yields the bitwise (inclusive) OR of its arguments,
which must be integers or one of them must be a custom object overriding
*note __or__(): 23d2. or *note __ror__(): 23db. special methods.


File: python.info,  Node: Comparisons,  Next: Boolean operations,  Prev: Binary bitwise operations,  Up: Expressions

4.6.10 Comparisons
------------------

Unlike C, all comparison operations in Python have the same priority,
which is lower than that of any arithmetic, shifting or bitwise
operation.  Also unlike C, expressions like ‘a < b < c’ have the
interpretation that is conventional in mathematics:

     comparison:    *note or_expr: 22eb. (*note comp_operator: 24af. *note or_expr: 22eb.)*
     comp_operator: "<" | ">" | "==" | ">=" | "<=" | "!="
                    | "is" ["not"] | ["not"] "in"

Comparisons yield boolean values: ‘True’ or ‘False’.  Custom 'rich
comparison methods' may return non-boolean values.  In this case Python
will call *note bool(): 3c3. on such value in boolean contexts.

Comparisons can be chained arbitrarily, e.g., ‘x < y <= z’ is equivalent
to ‘x < y and y <= z’, except that ‘y’ is evaluated only once (but in
both cases ‘z’ is not evaluated at all when ‘x < y’ is found to be
false).

Formally, if 'a', 'b', 'c', …, 'y', 'z' are expressions and 'op1',
'op2', …, 'opN' are comparison operators, then ‘a op1 b op2 c ... y opN
z’ is equivalent to ‘a op1 b and b op2 c and ... y opN z’, except that
each expression is evaluated at most once.

Note that ‘a op1 b op2 c’ doesn’t imply any kind of comparison between
'a' and 'c', so that, e.g., ‘x < y > z’ is perfectly legal (though
perhaps not pretty).

* Menu:

* Value comparisons::
* Membership test operations::
* Identity comparisons::


File: python.info,  Node: Value comparisons,  Next: Membership test operations,  Up: Comparisons

4.6.10.1 Value comparisons
..........................

The operators ‘<’, ‘>’, ‘==’, ‘>=’, ‘<=’, and ‘!=’ compare the values of
two objects.  The objects do not need to have the same type.

Chapter *note Objects, values and types: 2315. states that objects have
a value (in addition to type and identity).  The value of an object is a
rather abstract notion in Python: For example, there is no canonical
access method for an object’s value.  Also, there is no requirement that
the value of an object should be constructed in a particular way, e.g.
comprised of all its data attributes.  Comparison operators implement a
particular notion of what the value of an object is.  One can think of
them as defining the value of an object indirectly, by means of their
comparison implementation.

Because all types are (direct or indirect) subtypes of *note object:
c80, they inherit the default comparison behavior from *note object:
c80.  Types can customize their comparison behavior by implementing
'rich comparison methods' like *note __lt__(): 14a8, described in *note
Basic customization: 2393.

The default behavior for equality comparison (‘==’ and ‘!=’) is based on
the identity of the objects.  Hence, equality comparison of instances
with the same identity results in equality, and equality comparison of
instances with different identities results in inequality.  A motivation
for this default behavior is the desire that all objects should be
reflexive (i.e.  ‘x is y’ implies ‘x == y’).

A default order comparison (‘<’, ‘>’, ‘<=’, and ‘>=’) is not provided;
an attempt raises *note TypeError: 198.  A motivation for this default
behavior is the lack of a similar invariant as for equality.

The behavior of the default equality comparison, that instances with
different identities are always unequal, may be in contrast to what
types will need that have a sensible definition of object value and
value-based equality.  Such types will need to customize their
comparison behavior, and in fact, a number of built-in types have done
that.

The following list describes the comparison behavior of the most
important built-in types.

   * Numbers of built-in numeric types (*note Tipi Numerici — int,
     float, complex: 1fc4.) and of the standard library types *note
     fractions.Fraction: 213. and *note decimal.Decimal: 1fe. can be
     compared within and across their types, with the restriction that
     complex numbers do not support order comparison.  Within the limits
     of the types involved, they compare mathematically
     (algorithmically) correct without loss of precision.

     The not-a-number values ‘float('NaN')’ and ‘decimal.Decimal('NaN')’
     are special.  Any ordered comparison of a number to a not-a-number
     value is false.  A counter-intuitive implication is that
     not-a-number values are not equal to themselves.  For example, if
     ‘x = float('NaN')’, ‘3 < x’, ‘x < 3’ and ‘x == x’ are all false,
     while ‘x != x’ is true.  This behavior is compliant with IEEE 754.

   * ‘None’ and *note NotImplemented: 1a2. are singletons.  PEP 8(1)
     advises that comparisons for singletons should always be done with
     ‘is’ or ‘is not’, never the equality operators.

   * Binary sequences (instances of *note bytes: 192. or *note
     bytearray: 344.) can be compared within and across their types.
     They compare lexicographically using the numeric values of their
     elements.

   * Strings (instances of *note str: 169.) compare lexicographically
     using the numerical Unicode code points (the result of the built-in
     function *note ord(): 2323.) of their characters.  (2)

     Strings and binary sequences cannot be directly compared.

   * Sequences (instances of *note tuple: 614, *note list: 24d, or *note
     range: b3f.) can be compared only within each of their types, with
     the restriction that ranges do not support order comparison.
     Equality comparison across these types results in inequality, and
     ordering comparison across these types raises *note TypeError: 198.

     Sequences compare lexicographically using comparison of
     corresponding elements.  The built-in containers typically assume
     identical objects are equal to themselves.  That lets them bypass
     equality tests for identical objects to improve performance and to
     maintain their internal invariants.

     Lexicographical comparison between built-in collections works as
     follows:

        - For two collections to compare equal, they must be of the same
          type, have the same length, and each pair of corresponding
          elements must compare equal (for example, ‘[1,2] == (1,2)’ is
          false because the type is not the same).

        - Collections that support order comparison are ordered the same
          as their first unequal elements (for example, ‘[1,2,x] <=
          [1,2,y]’ has the same value as ‘x <= y’).  If a corresponding
          element does not exist, the shorter collection is ordered
          first (for example, ‘[1,2] < [1,2,3]’ is true).

   * Mappings (instances of *note dict: 183.) compare equal if and only
     if they have equal ‘(key, value)’ pairs.  Equality comparison of
     the keys and values enforces reflexivity.

     Order comparisons (‘<’, ‘>’, ‘<=’, and ‘>=’) raise *note TypeError:
     198.

   * Sets (instances of *note set: 184. or *note frozenset: 7f3.) can be
     compared within and across their types.

     They define order comparison operators to mean subset and superset
     tests.  Those relations do not define total orderings (for example,
     the two sets ‘{1,2}’ and ‘{2,3}’ are not equal, nor subsets of one
     another, nor supersets of one another).  Accordingly, sets are not
     appropriate arguments for functions which depend on total ordering
     (for example, *note min(): 110d, *note max(): 110e, and *note
     sorted(): dc9. produce undefined results given a list of sets as
     inputs).

     Comparison of sets enforces reflexivity of its elements.

   * Most other built-in types have no comparison methods implemented,
     so they inherit the default comparison behavior.

User-defined classes that customize their comparison behavior should
follow some consistency rules, if possible:

   * Equality comparison should be reflexive.  In other words, identical
     objects should compare equal:

          ‘x is y’ implies ‘x == y’

   * Comparison should be symmetric.  In other words, the following
     expressions should have the same result:

          ‘x == y’ and ‘y == x’

          ‘x != y’ and ‘y != x’

          ‘x < y’ and ‘y > x’

          ‘x <= y’ and ‘y >= x’

   * Comparison should be transitive.  The following (non-exhaustive)
     examples illustrate that:

          ‘x > y and y > z’ implies ‘x > z’

          ‘x < y and y <= z’ implies ‘x < z’

   * Inverse comparison should result in the boolean negation.  In other
     words, the following expressions should have the same result:

          ‘x == y’ and ‘not x != y’

          ‘x < y’ and ‘not x >= y’ (for total ordering)

          ‘x > y’ and ‘not x <= y’ (for total ordering)

     The last two expressions apply to totally ordered collections (e.g.
     to sequences, but not to sets or mappings).  See also the *note
     total_ordering(): 1144. decorator.

   * The *note hash(): 802. result should be consistent with equality.
     Objects that are equal should either have the same hash value, or
     be marked as unhashable.

Python does not enforce these consistency rules.  In fact, the
not-a-number values are an example for not following these rules.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0008/

   (2) The Unicode standard distinguishes between 'code points' (e.g.
U+0041) and 'abstract characters' (e.g.  «LATIN CAPITAL LETTER A»).
While most abstract characters in Unicode are only represented using one
code point, there is a number of abstract characters that can in
addition be represented using a sequence of more than one code point.
For example, the abstract character «LATIN CAPITAL LETTER C WITH
CEDILLA» can be represented as a single 'precomposed character' at code
position U+00C7, or as a sequence of a 'base character' at code position
U+0043 (LATIN CAPITAL LETTER C), followed by a 'combining character' at
code position U+0327 (COMBINING CEDILLA).

The comparison operators on strings compare at the level of Unicode code
points.  This may be counter-intuitive to humans.  For example,
‘"\u00C7" == "\u0043\u0327"’ is ‘False’, even though both strings
represent the same abstract character «LATIN CAPITAL LETTER C WITH
CEDILLA».

To compare strings at the level of abstract characters (that is, in a
way intuitive to humans), use *note unicodedata.normalize(): 8e5.


File: python.info,  Node: Membership test operations,  Next: Identity comparisons,  Prev: Value comparisons,  Up: Comparisons

4.6.10.2 Membership test operations
...................................

The operators *note in: 34b. and *note not in: 842. test for membership.
‘x in s’ evaluates to ‘True’ if 'x' is a member of 's', and ‘False’
otherwise.  ‘x not in s’ returns the negation of ‘x in s’.  All built-in
sequences and set types support this as well as dictionary, for which
‘in’ tests whether the dictionary has a given key.  For container types
such as list, tuple, set, frozenset, dict, or collections.deque, the
expression ‘x in y’ is equivalent to ‘any(x is e or x == e for e in y)’.

For the string and bytes types, ‘x in y’ is ‘True’ if and only if 'x' is
a substring of 'y'.  An equivalent test is ‘y.find(x) != -1’.  Empty
strings are always considered to be a substring of any other string, so
‘"" in "abc"’ will return ‘True’.

For user-defined classes which define the *note __contains__(): 15c1.
method, ‘x in y’ returns ‘True’ if ‘y.__contains__(x)’ returns a true
value, and ‘False’ otherwise.

For user-defined classes which do not define *note __contains__(): 15c1.
but do define *note __iter__(): e6b, ‘x in y’ is ‘True’ if some value
‘z’, for which the expression ‘x is z or x == z’ is true, is produced
while iterating over ‘y’.  If an exception is raised during the
iteration, it is as if *note in: 34b. raised that exception.

Lastly, the old-style iteration protocol is tried: if a class defines
*note __getitem__(): 588, ‘x in y’ is ‘True’ if and only if there is a
non-negative integer index 'i' such that ‘x is y[i] or x == y[i]’, and
no lower integer index raises the *note IndexError: 173c. exception.
(If any other exception is raised, it is as if *note in: 34b. raised
that exception).

The operator *note not in: 842. is defined to have the inverse truth
value of *note in: 34b.


File: python.info,  Node: Identity comparisons,  Prev: Membership test operations,  Up: Comparisons

4.6.10.3 Identity comparisons
.............................

The operators *note is: 34c. and *note is not: 24b3. test for an
object’s identity: ‘x is y’ is true if and only if 'x' and 'y' are the
same object.  An Object’s identity is determined using the *note id():
162a. function.  ‘x is not y’ yields the inverse truth value.  (1)

   ---------- Footnotes ----------

   (1) Due to automatic garbage-collection, free lists, and the dynamic
nature of descriptors, you may notice seemingly unusual behaviour in
certain uses of the *note is: 34c. operator, like those involving
comparisons between instance methods, or constants.  Check their
documentation for more info.


File: python.info,  Node: Boolean operations,  Next: Assignment expressions<2>,  Prev: Comparisons,  Up: Expressions

4.6.11 Boolean operations
-------------------------

     or_test:  *note and_test: 24b7. | *note or_test: 2464. "or" *note and_test: 24b7.
     and_test: *note not_test: 24b8. | *note and_test: 24b7. "and" *note not_test: 24b8.
     not_test: *note comparison: 24ae. | "not" *note not_test: 24b8.

In the context of Boolean operations, and also when expressions are used
by control flow statements, the following values are interpreted as
false: ‘False’, ‘None’, numeric zero of all types, and empty strings and
containers (including strings, tuples, lists, dictionaries, sets and
frozensets).  All other values are interpreted as true.  User-defined
objects can customize their truth value by providing a *note __bool__():
14dd. method.

The operator *note not: 24b6. yields ‘True’ if its argument is false,
‘False’ otherwise.

The expression ‘x and y’ first evaluates 'x'; if 'x' is false, its value
is returned; otherwise, 'y' is evaluated and the resulting value is
returned.

The expression ‘x or y’ first evaluates 'x'; if 'x' is true, its value
is returned; otherwise, 'y' is evaluated and the resulting value is
returned.

Note that neither *note and: 349. nor *note or: 34d. restrict the value
and type they return to ‘False’ and ‘True’, but rather return the last
evaluated argument.  This is sometimes useful, e.g., if ‘s’ is a string
that should be replaced by a default value if it is empty, the
expression ‘s or 'foo'’ yields the desired value.  Because *note not:
24b6. has to create a new value, it returns a boolean value regardless
of the type of its argument (for example, ‘not 'foo'’ produces ‘False’
rather than ‘''’.)


File: python.info,  Node: Assignment expressions<2>,  Next: Conditional expressions,  Prev: Boolean operations,  Up: Expressions

4.6.12 Assignment expressions
-----------------------------

     assignment_expression: [*note identifier: 22aa. ":="] *note expression: 182.

An assignment expression (sometimes also called a «named expression» or
«walrus») assigns an *note expression: 182. to an *note identifier:
22aa, while also returning the value of the *note expression: 182.

One common use case is when handling matched regular expressions:

     if matching := pattern.search(data):
         do_something(matching)

Or, when processing a file stream in chunks:

     while chunk := file.read(9000):
         process(chunk)

Assignment expressions must be surrounded by parentheses when used as
expression statements and when used as sub-expressions in slicing,
conditional, lambda, keyword-argument, and comprehension-if expressions
and in ‘assert’, ‘with’, and ‘assignment’ statements.  In all other
places where they can be used, parentheses are not required, including
in ‘if’ and ‘while’ statements.

Added in version 3.8: See PEP 572(1) for more details about assignment
expressions.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0572/


File: python.info,  Node: Conditional expressions,  Next: Lambdas,  Prev: Assignment expressions<2>,  Up: Expressions

4.6.13 Conditional expressions
------------------------------

     conditional_expression: *note or_test: 2464. ["if" *note or_test: 2464. "else" *note expression: 182.]
     expression:             *note conditional_expression: 22ea. | *note lambda_expr: 24bc.

A conditional expression (sometimes called a «ternary operator») is an
alternative to the if-else statement.  As it is an expression, it
returns a value and can appear as a sub-expression.

The expression ‘x if C else y’ first evaluates the condition, 'C' rather
than 'x'.  If 'C' is true, 'x' is evaluated and its value is returned;
otherwise, 'y' is evaluated and its value is returned.

See PEP 308(1) for more details about conditional expressions.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0308/


File: python.info,  Node: Lambdas,  Next: Expression lists,  Prev: Conditional expressions,  Up: Expressions

4.6.14 Lambdas
--------------

     lambda_expr: "lambda" [*note parameter_list: 24bf.] ":" *note expression: 182.

Lambda expressions (sometimes called lambda forms) are used to create
anonymous functions.  The expression ‘lambda parameters: expression’
yields a function object.  The unnamed object behaves like a function
object defined with:

     def <lambda>(parameters):
         return expression

See section *note Function definitions: 2002. for the syntax of
parameter lists.  Note that functions created with lambda expressions
cannot contain statements or annotations.


File: python.info,  Node: Expression lists,  Next: Evaluation order,  Prev: Lambdas,  Up: Expressions

4.6.15 Expression lists
-----------------------

     starred_expression:       "*" *note or_expr: 22eb. | *note expression: 182.
     flexible_expression:      *note assignment_expression: 2411. | *note starred_expression: 245f.
     flexible_expression_list: *note flexible_expression: 24c1. ("," *note flexible_expression: 24c1.)* [","]
     starred_expression_list:  *note starred_expression: 245f. ("," *note starred_expression: 245f.)* [","]
     expression_list:          *note expression: 182. ("," *note expression: 182.)* [","]
     yield_list:               *note expression_list: 24c3. | *note starred_expression: 245f. "," [*note starred_expression_list: 24c2.]

Except when part of a list or set display, an expression list containing
at least one comma yields a tuple.  The length of the tuple is the
number of expressions in the list.  The expressions are evaluated from
left to right.

An asterisk ‘*’ denotes 'iterable unpacking'.  Its operand must be an
*note iterable: 142f.  The iterable is expanded into a sequence of
items, which are included in the new tuple, list, or set, at the site of
the unpacking.

Added in version 3.5: Iterable unpacking in expression lists, originally
proposed by PEP 448(1).

Added in version 3.11: Any item in an expression list may be starred.
See PEP 646(2).

A trailing comma is required only to create a one-item tuple, such as
‘1,’; it is optional in all other cases.  A single expression without a
trailing comma doesn’t create a tuple, but rather yields the value of
that expression.  (To create an empty tuple, use an empty pair of
parentheses: ‘()’.)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0448/

   (2) https://peps.python.org/pep-0646/


File: python.info,  Node: Evaluation order,  Next: Operator precedence,  Prev: Expression lists,  Up: Expressions

4.6.16 Evaluation order
-----------------------

Python evaluates expressions from left to right.  Notice that while
evaluating an assignment, the right-hand side is evaluated before the
left-hand side.

In the following lines, expressions will be evaluated in the arithmetic
order of their suffixes:

     expr1, expr2, expr3, expr4
     (expr1, expr2, expr3, expr4)
     {expr1: expr2, expr3: expr4}
     expr1 + expr2 * (expr3 - expr4)
     expr1(expr2, expr3, *expr4, **expr5)
     expr3, expr4 = expr1, expr2


File: python.info,  Node: Operator precedence,  Prev: Evaluation order,  Up: Expressions

4.6.17 Operator precedence
--------------------------

The following table summarizes the operator precedence in Python, from
highest precedence (most binding) to lowest precedence (least binding).
Operators in the same box have the same precedence.  Unless the syntax
is explicitly given, operators are binary.  Operators in the same box
group left to right (except for exponentiation and conditional
expressions, which group from right to left).

Note that comparisons, membership tests, and identity tests, all have
the same precedence and have a left-to-right chaining feature as
described in the *note Comparisons: 24ac. section.

Operator                                            Description
                                                    
----------------------------------------------------------------------------------------------
                                                    
‘(expressions...)’,                                 Binding or parenthesized expression,
                                                    list display, dictionary display, set
‘[expressions...]’, ‘{key: value...}’,              display
‘{expressions...}’                                  

‘x[index]’, ‘x[index:index]’, ‘x(arguments...)’,    Subscription, slicing, call, attribute
‘x.attribute’                                       reference
                                                    
                                                    
*note await x: 18d.                                 Await expression
                                                    
                                                    
‘**’                                                Exponentiation (1)
                                                    
                                                    
‘+x’, ‘-x’, ‘~x’                                    Positive, negative, bitwise NOT
                                                    
                                                    
‘*’, ‘@’, ‘/’, ‘//’, ‘%’                            Multiplication, matrix multiplication,
                                                    division, floor division, remainder (2)
                                                    
                                                    
‘+’, ‘-’                                            Addition and subtraction
                                                    
                                                    
‘<<’, ‘>>’                                          Shifts
                                                    
                                                    
‘&’                                                 Bitwise AND
                                                    
                                                    
‘^’                                                 Bitwise XOR
                                                    
                                                    
‘|’                                                 Bitwise OR
                                                    
                                                    
*note in: 34b, *note not in: 842, *note is: 34c,    Comparisons, including membership tests
*note is not: 24b3, ‘<’, ‘<=’, ‘>’, ‘>=’, ‘!=’,     and identity tests
‘==’                                                

*note not x: 24b6.                                  Boolean NOT
                                                    
                                                    
*note and: 349.                                     Boolean AND
                                                    
                                                    
*note or: 34d.                                      Boolean OR
                                                    
                                                    
*note if: 17d. – ‘else’                             Conditional expression
                                                    
                                                    
*note lambda: 14a5.                                 Lambda expression
                                                    
                                                    
‘:=’                                                Assignment expression
                                                    

   ---------- Footnotes ----------

   (1) The power operator ‘**’ binds less tightly than an arithmetic or
bitwise unary operator on its right, that is, ‘2**-1’ is ‘0.5’.

   (2) The ‘%’ operator is also used for string formatting; the same
precedence applies.


File: python.info,  Node: Simple statements,  Next: Compound statements,  Prev: Expressions,  Up: The Python Language Reference

4.7 Simple statements
=====================

A simple statement is comprised within a single logical line.  Several
simple statements may occur on a single line separated by semicolons.
The syntax for simple statements is:

     simple_stmt: *note expression_stmt: 24cd.
                  | *note assert_stmt: 24ce.
                  | *note assignment_stmt: 24cf.
                  | *note augmented_assignment_stmt: 24d0.
                  | *note annotated_assignment_stmt: 24d1.
                  | *note pass_stmt: 24d2.
                  | *note del_stmt: 24d3.
                  | *note return_stmt: 24d4.
                  | *note yield_stmt: 24d5.
                  | *note raise_stmt: 24d6.
                  | *note break_stmt: 24d7.
                  | *note continue_stmt: 24d8.
                  | *note import_stmt: 24d9.
                  | *note future_stmt: 24da.
                  | *note global_stmt: 24db.
                  | *note nonlocal_stmt: 24dc.
                  | *note type_stmt: 24dd.

* Menu:

* Expression statements::
* Assignment statements::
* The assert statement::
* The pass statement::
* The del statement::
* The return statement::
* The yield statement::
* The raise statement::
* The break statement::
* The continue statement::
* The import statement::
* The global statement::
* The nonlocal statement::
* The type statement::


File: python.info,  Node: Expression statements,  Next: Assignment statements,  Up: Simple statements

4.7.1 Expression statements
---------------------------

Expression statements are used (mostly interactively) to compute and
write a value, or (usually) to call a procedure (a function that returns
no meaningful result; in Python, procedures return the value ‘None’).
Other uses of expression statements are allowed and occasionally useful.
The syntax for an expression statement is:

     expression_stmt: *note starred_expression: 245f.

An expression statement evaluates the expression list (which may be a
single expression).

In interactive mode, if the value is not ‘None’, it is converted to a
string using the built-in *note repr(): 1c1. function and the resulting
string is written to standard output on a line by itself (except if the
result is ‘None’, so that procedure calls do not cause any output.)


File: python.info,  Node: Assignment statements,  Next: The assert statement,  Prev: Expression statements,  Up: Simple statements

4.7.2 Assignment statements
---------------------------

Assignment statements are used to (re)bind names to values and to modify
attributes or items of mutable objects:

     assignment_stmt: (*note target_list: 2463. "=")+ (*note starred_expression: 245f. | *note yield_expression: 22ec.)
     target_list:     *note target: 24e1. ("," *note target: 24e1.)* [","]
     target:          *note identifier: 22aa.
                      | "(" [*note target_list: 2463.] ")"
                      | "[" [*note target_list: 2463.] "]"
                      | *note attributeref: 2481.
                      | *note subscription: 2482.
                      | *note slicing: 2483.
                      | "*" *note target: 24e1.

(See section *note Primaries: 247f. for the syntax definitions for
'attributeref', 'subscription', and 'slicing'.)

An assignment statement evaluates the expression list (remember that
this can be a single expression or a comma-separated list, the latter
yielding a tuple) and assigns the single resulting object to each of the
target lists, from left to right.

Assignment is defined recursively depending on the form of the target
(list).  When a target is part of a mutable object (an attribute
reference, subscription or slicing), the mutable object must ultimately
perform the assignment and decide about its validity, and may raise an
exception if the assignment is unacceptable.  The rules observed by
various types and the exceptions raised are given with the definition of
the object types (see section *note The standard type hierarchy: 2318.).

Assignment of an object to a target list, optionally enclosed in
parentheses or square brackets, is recursively defined as follows.

   * If the target list is a single target with no trailing comma,
     optionally in parentheses, the object is assigned to that target.

   * Else:

        * If the target list contains one target prefixed with an
          asterisk, called a «starred» target: The object must be an
          iterable with at least as many items as there are targets in
          the target list, minus one.  The first items of the iterable
          are assigned, from left to right, to the targets before the
          starred target.  The final items of the iterable are assigned
          to the targets after the starred target.  A list of the
          remaining items in the iterable is then assigned to the
          starred target (the list can be empty).

        * Else: The object must be an iterable with the same number of
          items as there are targets in the target list, and the items
          are assigned, from left to right, to the corresponding
          targets.

Assignment of an object to a single target is recursively defined as
follows.

   * If the target is an identifier (name):

        * If the name does not occur in a *note global: 4ad. or *note
          nonlocal: 14af. statement in the current code block: the name
          is bound to the object in the current local namespace.

        * Otherwise: the name is bound to the object in the global
          namespace or the outer namespace determined by *note nonlocal:
          14af, respectively.

     The name is rebound if it was already bound.  This may cause the
     reference count for the object previously bound to the name to
     reach zero, causing the object to be deallocated and its destructor
     (if it has one) to be called.

   * If the target is an attribute reference: The primary expression in
     the reference is evaluated.  It should yield an object with
     assignable attributes; if this is not the case, *note TypeError:
     198. is raised.  That object is then asked to assign the assigned
     object to the given attribute; if it cannot perform the assignment,
     it raises an exception (usually but not necessarily *note
     AttributeError: 5f0.).  Note: If the object is a class instance and
     the attribute reference occurs on both sides of the assignment
     operator, the right-hand side expression, ‘a.x’ can access either
     an instance attribute or (if no instance attribute exists) a class
     attribute.  The left-hand side target ‘a.x’ is always set as an
     instance attribute, creating it if necessary.  Thus, the two
     occurrences of ‘a.x’ do not necessarily refer to the same
     attribute: if the right-hand side expression refers to a class
     attribute, the left-hand side creates a new instance attribute as
     the target of the assignment:

          class Cls:
              x = 3             # class variable
          inst = Cls()
          inst.x = inst.x + 1   # writes inst.x as 4 leaving Cls.x as 3

     This description does not necessarily apply to descriptor
     attributes, such as properties created with *note property(): 4b4.

   * If the target is a subscription: The primary expression in the
     reference is evaluated.  It should yield either a mutable sequence
     object (such as a list) or a mapping object (such as a dictionary).
     Next, the subscript expression is evaluated.

     If the primary is a mutable sequence object (such as a list), the
     subscript must yield an integer.  If it is negative, the sequence’s
     length is added to it.  The resulting value must be a nonnegative
     integer less than the sequence’s length, and the sequence is asked
     to assign the assigned object to its item with that index.  If the
     index is out of range, *note IndexError: 173c. is raised
     (assignment to a subscripted sequence cannot add new items to a
     list).

     If the primary is a mapping object (such as a dictionary), the
     subscript must have a type compatible with the mapping’s key type,
     and the mapping is then asked to create a key/value pair which maps
     the subscript to the assigned object.  This can either replace an
     existing key/value pair with the same key value, or insert a new
     key/value pair (if no key with the same value existed).

     For user-defined objects, the *note __setitem__(): 14d3. method is
     called with appropriate arguments.

   * If the target is a slicing: The primary expression in the reference
     is evaluated.  It should yield a mutable sequence object (such as a
     list).  The assigned object should be a sequence object of the same
     type.  Next, the lower and upper bound expressions are evaluated,
     insofar they are present; defaults are zero and the sequence’s
     length.  The bounds should evaluate to integers.  If either bound
     is negative, the sequence’s length is added to it.  The resulting
     bounds are clipped to lie between zero and the sequence’s length,
     inclusive.  Finally, the sequence object is asked to replace the
     slice with the items of the assigned sequence.  The length of the
     slice may be different from the length of the assigned sequence,
     thus changing the length of the target sequence, if the target
     sequence allows it.

'Dettaglio dell’implementazione di CPython:' In the current
implementation, the syntax for targets is taken to be the same as for
expressions, and invalid syntax is rejected during the code generation
phase, causing less detailed error messages.

Although the definition of assignment implies that overlaps between the
left-hand side and the right-hand side are “simultaneous” (for example
‘a, b = b, a’ swaps two variables), overlaps 'within' the collection of
assigned-to variables occur left-to-right, sometimes resulting in
confusion.  For instance, the following program prints ‘[0, 2]’:

     x = [0, 1]
     i = 0
     i, x[i] = 1, 2         # i is updated, then x[i] is updated
     print(x)

Vedi anche
..........

PEP 3132(1) - Extended Iterable Unpacking

     The specification for the ‘*target’ feature.

* Menu:

* Augmented assignment statements::
* Annotated assignment statements::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3132/


File: python.info,  Node: Augmented assignment statements,  Next: Annotated assignment statements,  Up: Assignment statements

4.7.2.1 Augmented assignment statements
.......................................

Augmented assignment is the combination, in a single statement, of a
binary operation and an assignment statement:

     augmented_assignment_stmt: *note augtarget: 24e5. *note augop: 24e6. (*note expression_list: 24c3. | *note yield_expression: 22ec.)
     augtarget:                 *note identifier: 22aa. | *note attributeref: 2481. | *note subscription: 2482. | *note slicing: 2483.
     augop:                     "+=" | "-=" | "*=" | "@=" | "/=" | "//=" | "%=" | "**="
                                | ">>=" | "<<=" | "&=" | "^=" | "|="

(See section *note Primaries: 247f. for the syntax definitions of the
last three symbols.)

An augmented assignment evaluates the target (which, unlike normal
assignment statements, cannot be an unpacking) and the expression list,
performs the binary operation specific to the type of assignment on the
two operands, and assigns the result to the original target.  The target
is only evaluated once.

An augmented assignment statement like ‘x += 1’ can be rewritten as ‘x =
x + 1’ to achieve a similar, but not exactly equal effect.  In the
augmented version, ‘x’ is only evaluated once.  Also, when possible, the
actual operation is performed 'in-place', meaning that rather than
creating a new object and assigning that to the target, the old object
is modified instead.

Unlike normal assignments, augmented assignments evaluate the left-hand
side 'before' evaluating the right-hand side.  For example, ‘a[i] +=
f(x)’ first looks-up ‘a[i]’, then it evaluates ‘f(x)’ and performs the
addition, and lastly, it writes the result back to ‘a[i]’.

With the exception of assigning to tuples and multiple targets in a
single statement, the assignment done by augmented assignment statements
is handled the same way as normal assignments.  Similarly, with the
exception of the possible 'in-place' behavior, the binary operation
performed by augmented assignment is the same as the normal binary
operations.

For targets which are attribute references, the same *note caveat about
class and instance attributes: 24e2. applies as for regular assignments.


File: python.info,  Node: Annotated assignment statements,  Prev: Augmented assignment statements,  Up: Assignment statements

4.7.2.2 Annotated assignment statements
.......................................

*note Annotation: f53. assignment is the combination, in a single
statement, of a variable or attribute annotation and an optional
assignment statement:

     annotated_assignment_stmt: *note augtarget: 24e5. ":" *note expression: 182.
                                ["=" (*note starred_expression: 245f. | *note yield_expression: 22ec.)]

The difference from normal *note Assignment statements: 240b. is that
only a single target is allowed.

The assignment target is considered «simple» if it consists of a single
name that is not enclosed in parentheses.  For simple assignment
targets, if in class or module scope, the annotations are gathered in a
lazily evaluated *note annotation scope: 4ac.  The annotations can be
evaluated using the *note __annotations__: 458. attribute of a class or
module, or using the facilities in the *note annotationlib: 6. module.

If the assignment target is not simple (an attribute, subscript node, or
parenthesized name), the annotation is never evaluated.

If a name is annotated in a function scope, then this name is local for
that scope.  Annotations are never evaluated and stored in function
scopes.

If the right hand side is present, an annotated assignment performs the
actual assignment as if there was no annotation present.  If the right
hand side is not present for an expression target, then the interpreter
evaluates the target except for the last *note __setitem__(): 14d3. or
*note __setattr__(): 2362. call.

Vedi anche
..........

PEP 526(1) - Syntax for Variable Annotations

     The proposal that added syntax for annotating the types of
     variables (including class variables and instance variables),
     instead of expressing them through comments.

PEP 484(2) - Type hints

     The proposal that added the *note typing: 10a. module to provide a
     standard syntax for type annotations that can be used in static
     analysis tools and IDEs.

Cambiato nella versione 3.8: Now annotated assignments allow the same
expressions in the right hand side as regular assignments.  Previously,
some expressions (like un-parenthesized tuple expressions) caused a
syntax error.

Cambiato nella versione 3.14: Annotations are now lazily evaluated in a
separate *note annotation scope: 4ac.  If the assignment target is not
simple, annotations are never evaluated.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0526/

   (2) https://peps.python.org/pep-0484/


File: python.info,  Node: The assert statement,  Next: The pass statement,  Prev: Assignment statements,  Up: Simple statements

4.7.3 The ‘assert’ statement
----------------------------

Assert statements are a convenient way to insert debugging assertions
into a program:

     assert_stmt: "assert" *note expression: 182. ["," *note expression: 182.]

The simple form, ‘assert expression’, is equivalent to

     if __debug__:
         if not expression: raise AssertionError

The extended form, ‘assert expression1, expression2’, is equivalent to

     if __debug__:
         if not expression1: raise AssertionError(expression2)

These equivalences assume that *note __debug__: 9dc. and *note
AssertionError: 8b9. refer to the built-in variables with those names.
In the current implementation, the built-in variable ‘__debug__’ is
‘True’ under normal circumstances, ‘False’ when optimization is
requested (command line option *note -O: 18c.).  The current code
generator emits no code for an *note assert: b62. statement when
optimization is requested at compile time.  Note that it is unnecessary
to include the source code for the expression that failed in the error
message; it will be displayed as part of the stack trace.

Assignments to *note __debug__: 9dc. are illegal.  The value for the
built-in variable is determined when the interpreter starts.


File: python.info,  Node: The pass statement,  Next: The del statement,  Prev: The assert statement,  Up: Simple statements

4.7.4 The ‘pass’ statement
--------------------------

     pass_stmt: "pass"

*note pass: 17e. is a null operation — when it is executed, nothing
happens.  It is useful as a placeholder when a statement is required
syntactically, but no code needs to be executed, for example:

     def f(arg): pass    # a function that does nothing (yet)

     class C: pass       # a class with no methods (yet)


File: python.info,  Node: The del statement,  Next: The return statement,  Prev: The pass statement,  Up: Simple statements

4.7.5 The ‘del’ statement
-------------------------

     del_stmt: "del" *note target_list: 2463.

Deletion is recursively defined very similar to the way assignment is
defined.  Rather than spelling it out in full details, here are some
hints.

Deletion of a target list recursively deletes each target, from left to
right.

Deletion of a name removes the binding of that name from the local or
global namespace, depending on whether the name occurs in a *note
global: 4ad. statement in the same code block.  Trying to delete an
unbound name raises a *note NameError: 452. exception.

Deletion of attribute references, subscriptions and slicings is passed
to the primary object involved; deletion of a slicing is in general
equivalent to assignment of an empty slice of the right type (but even
this is determined by the sliced object).

Cambiato nella versione 3.2: Previously it was illegal to delete a name
from the local namespace if it occurs as a free variable in a nested
block.


File: python.info,  Node: The return statement,  Next: The yield statement,  Prev: The del statement,  Up: Simple statements

4.7.6 The ‘return’ statement
----------------------------

     return_stmt: "return" [*note expression_list: 24c3.]

*note return: 1af. may only occur syntactically nested in a function
definition, not within a nested class definition.

If an expression list is present, it is evaluated, else ‘None’ is
substituted.

*note return: 1af. leaves the current function call with the expression
list (or ‘None’) as return value.

When *note return: 1af. passes control out of a *note try: 8f9.
statement with a *note finally: 1b0. clause, that ‘finally’ clause is
executed before really leaving the function.

In a generator function, the *note return: 1af. statement indicates that
the generator is done and will cause *note StopIteration: df7. to be
raised.  The returned value (if any) is used as an argument to construct
*note StopIteration: df7. and becomes the *note StopIteration.value:
23fa. attribute.

In an asynchronous generator function, an empty *note return: 1af.
statement indicates that the asynchronous generator is done and will
cause *note StopAsyncIteration: 1df7. to be raised.  A non-empty
‘return’ statement is a syntax error in an asynchronous generator
function.


File: python.info,  Node: The yield statement,  Next: The raise statement,  Prev: The return statement,  Up: Simple statements

4.7.7 The ‘yield’ statement
---------------------------

     yield_stmt: *note yield_expression: 22ec.

A *note yield: bc4. statement is semantically equivalent to a *note
yield expression: 2473.  The ‘yield’ statement can be used to omit the
parentheses that would otherwise be required in the equivalent yield
expression statement.  For example, the yield statements

     yield <expr>
     yield from <expr>

are equivalent to the yield expression statements

     (yield <expr>)
     (yield from <expr>)

Yield expressions and statements are only used when defining a *note
generator: 1263. function, and are only used in the body of the
generator function.  Using *note yield: bc4. in a function definition is
sufficient to cause that definition to create a generator function
instead of a normal function.

For full details of *note yield: bc4. semantics, refer to the *note
Yield expressions: 2473. section.


File: python.info,  Node: The raise statement,  Next: The break statement,  Prev: The yield statement,  Up: Simple statements

4.7.8 The ‘raise’ statement
---------------------------

     raise_stmt: "raise" [*note expression: 182. ["from" *note expression: 182.]]

If no expressions are present, *note raise: 804. re-raises the exception
that is currently being handled, which is also known as the 'active
exception'.  If there isn’t currently an active exception, a *note
RuntimeError: 244. exception is raised indicating that this is an error.

Otherwise, *note raise: 804. evaluates the first expression as the
exception object.  It must be either a subclass or an instance of *note
BaseException: 7d8.  If it is a class, the exception instance will be
obtained when needed by instantiating the class with no arguments.

The 'type' of the exception is the exception instance’s class, the
'value' is the instance itself.

A traceback object is normally created automatically when an exception
is raised and attached to it as the *note __traceback__: 14ce.
attribute.  You can create an exception and set your own traceback in
one step using the *note with_traceback(): 24ef. exception method (which
returns the same exception instance, with its traceback set to its
argument), like so:

     raise Exception("foo occurred").with_traceback(tracebackobj)

The ‘from’ clause is used for exception chaining: if given, the second
'expression' must be another exception class or instance.  If the second
expression is an exception instance, it will be attached to the raised
exception as the *note __cause__: 14d0. attribute (which is writable).
If the expression is an exception class, the class will be instantiated
and the resulting exception instance will be attached to the raised
exception as the ‘__cause__’ attribute.  If the raised exception is not
handled, both exceptions will be printed:

     >>> try:
     ...     print(1 / 0)
     ... except Exception as exc:
     ...     raise RuntimeError("Something bad happened") from exc
     ...
     Traceback (most recent call last):
       File "<stdin>", line 2, in <module>
         print(1 / 0)
               ~~^~~
     ZeroDivisionError: division by zero

     The above exception was the direct cause of the following exception:

     Traceback (most recent call last):
       File "<stdin>", line 4, in <module>
         raise RuntimeError("Something bad happened") from exc
     RuntimeError: Something bad happened

A similar mechanism works implicitly if a new exception is raised when
an exception is already being handled.  An exception may be handled when
an *note except: 1ab. or *note finally: 1b0. clause, or a *note with:
186. statement, is used.  The previous exception is then attached as the
new exception’s *note __context__: 14cf. attribute:

     >>> try:
     ...     print(1 / 0)
     ... except:
     ...     raise RuntimeError("Something bad happened")
     ...
     Traceback (most recent call last):
       File "<stdin>", line 2, in <module>
         print(1 / 0)
               ~~^~~
     ZeroDivisionError: division by zero

     During handling of the above exception, another exception occurred:

     Traceback (most recent call last):
       File "<stdin>", line 4, in <module>
         raise RuntimeError("Something bad happened")
     RuntimeError: Something bad happened

Exception chaining can be explicitly suppressed by specifying *note
None: 886. in the ‘from’ clause:

     >>> try:
     ...     print(1 / 0)
     ... except:
     ...     raise RuntimeError("Something bad happened") from None
     ...
     Traceback (most recent call last):
       File "<stdin>", line 4, in <module>
     RuntimeError: Something bad happened

Additional information on exceptions can be found in section *note
Exceptions: 2417, and information about handling exceptions is in
section *note The try statement: 8f9.

Cambiato nella versione 3.3: *note None: 886. is now permitted as ‘Y’ in
‘raise X from Y’.

Added the *note __suppress_context__: 24f0. attribute to suppress
automatic display of the exception context.

Cambiato nella versione 3.11: If the traceback of the active exception
is modified in an *note except: 1ab. clause, a subsequent ‘raise’
statement re-raises the exception with the modified traceback.
Previously, the exception was re-raised with the traceback it had when
it was caught.


File: python.info,  Node: The break statement,  Next: The continue statement,  Prev: The raise statement,  Up: Simple statements

4.7.9 The ‘break’ statement
---------------------------

     break_stmt: "break"

*note break: 17f. may only occur syntactically nested in a *note for:
34a. or *note while: 195b. loop, but not nested in a function or class
definition within that loop.

It terminates the nearest enclosing loop, skipping the optional ‘else’
clause if the loop has one.

If a *note for: 34a. loop is terminated by *note break: 17f, the loop
control target keeps its current value.

When *note break: 17f. passes control out of a *note try: 8f9. statement
with a *note finally: 1b0. clause, that ‘finally’ clause is executed
before really leaving the loop.


File: python.info,  Node: The continue statement,  Next: The import statement,  Prev: The break statement,  Up: Simple statements

4.7.10 The ‘continue’ statement
-------------------------------

     continue_stmt: "continue"

*note continue: 180. may only occur syntactically nested in a *note for:
34a. or *note while: 195b. loop, but not nested in a function or class
definition within that loop.  It continues with the next cycle of the
nearest enclosing loop.

When *note continue: 180. passes control out of a *note try: 8f9.
statement with a *note finally: 1b0. clause, that ‘finally’ clause is
executed before really starting the next loop cycle.


File: python.info,  Node: The import statement,  Next: The global statement,  Prev: The continue statement,  Up: Simple statements

4.7.11 The ‘import’ statement
-----------------------------

     import_stmt:     "import" *note module: 24f4. ["as" *note identifier: 22aa.] ("," *note module: 24f4. ["as" *note identifier: 22aa.])*
                      | "from" *note relative_module: 24f5. "import" *note identifier: 22aa. ["as" *note identifier: 22aa.]
                      ("," *note identifier: 22aa. ["as" *note identifier: 22aa.])*
                      | "from" *note relative_module: 24f5. "import" "(" *note identifier: 22aa. ["as" *note identifier: 22aa.]
                      ("," *note identifier: 22aa. ["as" *note identifier: 22aa.])* [","] ")"
                      | "from" *note relative_module: 24f5. "import" "*"
     module:          (*note identifier: 22aa. ".")* *note identifier: 22aa.
     relative_module: "."* *note module: 24f4. | "."+

The basic import statement (no *note from: 14b3. clause) is executed in
two steps:

  1. find a module, loading and initializing it if necessary

  2. define a name or names in the local namespace for the scope where
     the *note import: 7f9. statement occurs.

When the statement contains multiple clauses (separated by commas) the
two steps are carried out separately for each clause, just as though the
clauses had been separated out into individual import statements.

The details of the first step, finding and loading modules, are
described in greater detail in the section on the *note import system:
2347, which also describes the various types of packages and modules
that can be imported, as well as all the hooks that can be used to
customize the import system.  Note that failures in this step may
indicate either that the module could not be located, 'or' that an error
occurred while initializing the module, which includes execution of the
module’s code.

If the requested module is retrieved successfully, it will be made
available in the local namespace in one of three ways:

   * If the module name is followed by ‘as’, then the name following
     ‘as’ is bound directly to the imported module.

   * If no other name is specified, and the module being imported is a
     top level module, the module’s name is bound in the local namespace
     as a reference to the imported module

   * If the module being imported is 'not' a top level module, then the
     name of the top level package that contains the module is bound in
     the local namespace as a reference to the top level package.  The
     imported module must be accessed using its full qualified name
     rather than directly

The *note from: 14b3. form uses a slightly more complex process:

  1. find the module specified in the *note from: 14b3. clause, loading
     and initializing it if necessary;

  2. for each of the identifiers specified in the *note import: 7f9.
     clauses:

       1. check if the imported module has an attribute by that name

       2. if not, attempt to import a submodule with that name and then
          check the imported module again for that attribute

       3. if the attribute is not found, *note ImportError: 65b. is
          raised.

       4. otherwise, a reference to that value is stored in the local
          namespace, using the name in the ‘as’ clause if it is present,
          otherwise using the attribute name

Examples:

     import foo                 # foo imported and bound locally
     import foo.bar.baz         # foo, foo.bar, and foo.bar.baz imported, foo bound locally
     import foo.bar.baz as fbb  # foo, foo.bar, and foo.bar.baz imported, foo.bar.baz bound as fbb
     from foo.bar import baz    # foo, foo.bar, and foo.bar.baz imported, foo.bar.baz bound as baz
     from foo import attr       # foo imported and foo.attr bound as attr

If the list of identifiers is replaced by a star (‘'*'’), all public
names defined in the module are bound in the local namespace for the
scope where the *note import: 7f9. statement occurs.

The 'public names' defined by a module are determined by checking the
module’s namespace for a variable named ‘__all__’; if defined, it must
be a sequence of strings which are names defined or imported by that
module.  The names given in ‘__all__’ are all considered public and are
required to exist.  If ‘__all__’ is not defined, the set of public names
includes all names found in the module’s namespace which do not begin
with an underscore character (‘'_'’).  ‘__all__’ should contain the
entire public API. It is intended to avoid accidentally exporting items
that are not part of the API (such as library modules which were
imported and used within the module).

The wild card form of import — ‘from module import *’ — is only allowed
at the module level.  Attempting to use it in class or function
definitions will raise a *note SyntaxError: 18e.

When specifying what module to import you do not have to specify the
absolute name of the module.  When a module or package is contained
within another package it is possible to make a relative import within
the same top package without having to mention the package name.  By
using leading dots in the specified module or package after *note from:
14b3. you can specify how high to traverse up the current package
hierarchy without specifying exact names.  One leading dot means the
current package where the module making the import exists.  Two dots
means up one package level.  Three dots is up two levels, etc.  So if
you execute ‘from . import mod’ from a module in the ‘pkg’ package then
you will end up importing ‘pkg.mod’.  If you execute ‘from ..subpkg2
import mod’ from within ‘pkg.subpkg1’ you will import ‘pkg.subpkg2.mod’.
The specification for relative imports is contained in the *note Package
Relative Imports: 2441. section.

*note importlib.import_module(): 73d. is provided to support
applications that determine dynamically the modules to be loaded.

Raises an *note auditing event: 1c56. ‘import’ with arguments ‘module’,
‘filename’, ‘sys.path’, ‘sys.meta_path’, ‘sys.path_hooks’.

* Menu:

* Future statements::


File: python.info,  Node: Future statements,  Up: The import statement

4.7.11.1 Future statements
..........................

A 'future statement' is a directive to the compiler that a particular
module should be compiled using syntax or semantics that will be
available in a specified future release of Python where the feature
becomes standard.

The future statement is intended to ease migration to future versions of
Python that introduce incompatible changes to the language.  It allows
use of the new features on a per-module basis before the release in
which the feature becomes standard.

     future_stmt: "from" "__future__" "import" *note feature: 24f7. ["as" *note identifier: 22aa.]
                  ("," *note feature: 24f7. ["as" *note identifier: 22aa.])*
                  | "from" "__future__" "import" "(" *note feature: 24f7. ["as" *note identifier: 22aa.]
                  ("," *note feature: 24f7. ["as" *note identifier: 22aa.])* [","] ")"
     feature:     *note identifier: 22aa.

A future statement must appear near the top of the module.  The only
lines that can appear before a future statement are:

   * the module docstring (if any),

   * comments,

   * blank lines, and

   * other future statements.

The only feature that requires using the future statement is
‘annotations’ (see PEP 563(1)).

All historical features enabled by the future statement are still
recognized by Python 3.  The list includes ‘absolute_import’,
‘division’, ‘generators’, ‘generator_stop’, ‘unicode_literals’,
‘print_function’, ‘nested_scopes’ and ‘with_statement’.  They are all
redundant because they are always enabled, and only kept for backwards
compatibility.

A future statement is recognized and treated specially at compile time:
Changes to the semantics of core constructs are often implemented by
generating different code.  It may even be the case that a new feature
introduces new incompatible syntax (such as a new reserved word), in
which case the compiler may need to parse the module differently.  Such
decisions cannot be pushed off until runtime.

For any given release, the compiler knows which feature names have been
defined, and raises a compile-time error if a future statement contains
a feature not known to it.

The direct runtime semantics are the same as for any import statement:
there is a standard module *note __future__: 0, described later, and it
will be imported in the usual way at the time the future statement is
executed.

The interesting runtime semantics depend on the specific feature enabled
by the future statement.

Note that there is nothing special about the statement:

     import __future__ [as name]

That is not a future statement; it’s an ordinary import statement with
no special semantics or syntax restrictions.

Code compiled by calls to the built-in functions *note exec(): 4a3. and
*note compile(): 4b2. that occur in a module ‘M’ containing a future
statement will, by default, use the new syntax or semantics associated
with the future statement.  This can be controlled by optional arguments
to *note compile(): 4b2. — see the documentation of that function for
details.

A future statement typed at an interactive interpreter prompt will take
effect for the rest of the interpreter session.  If an interpreter is
started with the *note -i: 16e2. option, is passed a script name to
execute, and the script includes a future statement, it will be in
effect in the interactive session started after the script is executed.

Vedi anche
..........

PEP 236(2) - Back to the __future__

     The original proposal for the __future__ mechanism.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0563/

   (2) https://peps.python.org/pep-0236/


File: python.info,  Node: The global statement,  Next: The nonlocal statement,  Prev: The import statement,  Up: Simple statements

4.7.12 The ‘global’ statement
-----------------------------

     global_stmt: "global" *note identifier: 22aa. ("," *note identifier: 22aa.)*

The *note global: 4ad. statement causes the listed identifiers to be
interpreted as globals.  It would be impossible to assign to a global
variable without ‘global’, although free variables may refer to globals
without being declared global.

The ‘global’ statement applies to the entire current scope (module,
function body or class definition).  A *note SyntaxError: 18e. is raised
if a variable is used or assigned to prior to its global declaration in
the scope.

At the module level, all variables are global, so a ‘global’ statement
has no effect.  However, variables must still not be used or assigned to
prior to their ‘global’ declaration.  This requirement is relaxed in the
interactive prompt (*note REPL: 492.).

'Programmer’s note:' *note global: 4ad. is a directive to the parser.
It applies only to code parsed at the same time as the ‘global’
statement.  In particular, a ‘global’ statement contained in a string or
code object supplied to the built-in *note exec(): 4a3. function does
not affect the code block 'containing' the function call, and code
contained in such a string is unaffected by ‘global’ statements in the
code containing the function call.  The same applies to the *note
eval(): 4a4. and *note compile(): 4b2. functions.


File: python.info,  Node: The nonlocal statement,  Next: The type statement,  Prev: The global statement,  Up: Simple statements

4.7.13 The ‘nonlocal’ statement
-------------------------------

     nonlocal_stmt: "nonlocal" *note identifier: 22aa. ("," *note identifier: 22aa.)*

When the definition of a function or class is nested (enclosed) within
the definitions of other functions, its nonlocal scopes are the local
scopes of the enclosing functions.  The *note nonlocal: 14af. statement
causes the listed identifiers to refer to names previously bound in
nonlocal scopes.  It allows encapsulated code to rebind such nonlocal
identifiers.  If a name is bound in more than one nonlocal scope, the
nearest binding is used.  If a name is not bound in any nonlocal scope,
or if there is no nonlocal scope, a *note SyntaxError: 18e. is raised.

The *note nonlocal: 14af. statement applies to the entire scope of a
function or class body.  A *note SyntaxError: 18e. is raised if a
variable is used or assigned to prior to its nonlocal declaration in the
scope.

Vedi anche
..........

PEP 3104(1) - Access to Names in Outer Scopes

     The specification for the *note nonlocal: 14af. statement.

'Programmer’s note:' *note nonlocal: 14af. is a directive to the parser
and applies only to code parsed along with it.  See the note for the
*note global: 4ad. statement.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3104/


File: python.info,  Node: The type statement,  Prev: The nonlocal statement,  Up: Simple statements

4.7.14 The ‘type’ statement
---------------------------

     type_stmt: 'type' *note identifier: 22aa. [*note type_params: 24fb.] "=" *note expression: 182.

The ‘type’ statement declares a type alias, which is an instance of
*note typing.TypeAliasType: 2ae.

For example, the following statement creates a type alias:

     type Point = tuple[float, float]

This code is roughly equivalent to:

     annotation-def VALUE_OF_Point():
         return tuple[float, float]
     Point = typing.TypeAliasType("Point", VALUE_OF_Point())

‘annotation-def’ indicates an *note annotation scope: 4ac, which behaves
mostly like a function, but with several small differences.

The value of the type alias is evaluated in the annotation scope.  It is
not evaluated when the type alias is created, but only when the value is
accessed through the type alias’s ‘__value__’ attribute (see *note Lazy
evaluation: 686.).  This allows the type alias to refer to names that
are not yet defined.

Type aliases may be made generic by adding a *note type parameter list:
5ad. after the name.  See *note Generic type aliases: 685. for more.

‘type’ is a *note soft keyword: a0f.

Added in version 3.12.

Vedi anche
..........

PEP 695(1) - Type Parameter Syntax

     Introduced the ‘type’ statement and syntax for generic classes and
     functions.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0695/


File: python.info,  Node: Compound statements,  Next: Top-level components,  Prev: Simple statements,  Up: The Python Language Reference

4.8 Compound statements
=======================

Compound statements contain (groups of) other statements; they affect or
control the execution of those other statements in some way.  In
general, compound statements span multiple lines, although in simple
incarnations a whole compound statement may be contained in one line.

The *note if: 181, *note while: 195b. and *note for: 34a. statements
implement traditional control flow constructs.  *note try: 8f9.
specifies exception handlers and/or cleanup code for a group of
statements, while the *note with: 186. statement allows the execution of
initialization and finalization code around a block of code.  Function
and class definitions are also syntactically compound statements.

A compound statement consists of one or more “clauses.” A clause
consists of a header and a “suite.” The clause headers of a particular
compound statement are all at the same indentation level.  Each clause
header begins with a uniquely identifying keyword and ends with a colon.
A suite is a group of statements controlled by a clause.  A suite can be
one or more semicolon-separated simple statements on the same line as
the header, following the header’s colon, or it can be one or more
indented statements on subsequent lines.  Only the latter form of a
suite can contain nested compound statements; the following is illegal,
mostly because it wouldn’t be clear to which *note if: 181. clause a
following *note else: 17c. clause would belong:

     if test1: if test2: print(x)

Also note that the semicolon binds tighter than the colon in this
context, so that in the following example, either all or none of the
*note print(): 1177. calls are executed:

     if x < y < z: print(x); print(y); print(z)

Summarizing:

     compound_stmt: *note if_stmt: 2501.
                    | *note while_stmt: 2502.
                    | *note for_stmt: 2503.
                    | *note try_stmt: 2504.
                    | *note with_stmt: 2505.
                    | *note match_stmt: 2506.
                    | *note funcdef: 2507.
                    | *note classdef: 2508.
                    | *note async_with_stmt: 2509.
                    | *note async_for_stmt: 250a.
                    | *note async_funcdef: 250b.
     suite:         *note stmt_list: 250d. NEWLINE | NEWLINE INDENT *note statement: 250e.+ DEDENT
     statement:     *note stmt_list: 250d. NEWLINE | *note compound_stmt: 2500.
     stmt_list:     *note simple_stmt: 24cc. (";" *note simple_stmt: 24cc.)* [";"]

Note that statements always end in a ‘NEWLINE’ possibly followed by a
‘DEDENT’.  Also note that optional continuation clauses always begin
with a keyword that cannot start a statement, thus there are no
ambiguities (the “dangling *note else: 17c.” problem is solved in Python
by requiring nested *note if: 181. statements to be indented).

The formatting of the grammar rules in the following sections places
each clause on a separate line for clarity.
* Menu:

* The if statement::
* The while statement::
* The for statement::
* The try statement::
* The with statement::
* The match statement::
* Function definitions::
* Class definitions::
* Coroutines: Coroutines<2>.
* Type parameter lists::
* Annotations: Annotations<2>.


File: python.info,  Node: The if statement,  Next: The while statement,  Up: Compound statements

4.8.1 The ‘if’ statement
------------------------

The *note if: 181. statement is used for conditional execution:

     if_stmt: "if" *note assignment_expression: 2411. ":" *note suite: 250c.
              ("elif" *note assignment_expression: 2411. ":" *note suite: 250c.)*
              ["else" ":" *note suite: 250c.]

It selects exactly one of the suites by evaluating the expressions one
by one until one is found to be true (see section *note Boolean
operations: 24b4. for the definition of true and false); then that suite
is executed (and no other part of the *note if: 181. statement is
executed or evaluated).  If all expressions are false, the suite of the
*note else: 17c. clause, if present, is executed.


File: python.info,  Node: The while statement,  Next: The for statement,  Prev: The if statement,  Up: Compound statements

4.8.2 The ‘while’ statement
---------------------------

The *note while: 195b. statement is used for repeated execution as long
as an expression is true:

     while_stmt: "while" *note assignment_expression: 2411. ":" *note suite: 250c.
                 ["else" ":" *note suite: 250c.]

This repeatedly tests the expression and, if it is true, executes the
first suite; if the expression is false (which may be the first time it
is tested) the suite of the ‘else’ clause, if present, is executed and
the loop terminates.

A *note break: 17f. statement executed in the first suite terminates the
loop without executing the ‘else’ clause’s suite.  A *note continue:
180. statement executed in the first suite skips the rest of the suite
and goes back to testing the expression.


File: python.info,  Node: The for statement,  Next: The try statement,  Prev: The while statement,  Up: Compound statements

4.8.3 The ‘for’ statement
-------------------------

The *note for: 34a. statement is used to iterate over the elements of a
sequence (such as a string, tuple or list) or other iterable object:

     for_stmt: "for" *note target_list: 2463. "in" *note starred_expression_list: 24c2. ":" *note suite: 250c.
               ["else" ":" *note suite: 250c.]

The *note starred_expression_list: 24c2. expression is evaluated once;
it should yield an *note iterable: 142f. object.  An *note iterator:
4c9. is created for that iterable.  The first item provided by the
iterator is then assigned to the target list using the standard rules
for assignments (see *note Assignment statements: 240b.), and the suite
is executed.  This repeats for each item provided by the iterator.  When
the iterator is exhausted, the suite in the ‘else’ clause, if present,
is executed, and the loop terminates.

A *note break: 17f. statement executed in the first suite terminates the
loop without executing the ‘else’ clause’s suite.  A *note continue:
180. statement executed in the first suite skips the rest of the suite
and continues with the next item, or with the ‘else’ clause if there is
no next item.

The for-loop makes assignments to the variables in the target list.
This overwrites all previous assignments to those variables including
those made in the suite of the for-loop:

     for i in range(10):
         print(i)
         i = 5             # this will not affect the for-loop
                           # because i will be overwritten with the next
                           # index in the range

Names in the target list are not deleted when the loop is finished, but
if the sequence is empty, they will not have been assigned to at all by
the loop.  Hint: the built-in type *note range(): b3f. represents
immutable arithmetic sequences of integers.  For instance, iterating
‘range(3)’ successively yields 0, 1, and then 2.

Cambiato nella versione 3.11: Starred elements are now allowed in the
expression list.


File: python.info,  Node: The try statement,  Next: The with statement,  Prev: The for statement,  Up: Compound statements

4.8.4 The ‘try’ statement
-------------------------

The ‘try’ statement specifies exception handlers and/or cleanup code for
a group of statements:

     try_stmt:  *note try1_stmt: 2513. | *note try2_stmt: 2514. | *note try3_stmt: 2515.
     try1_stmt: "try" ":" *note suite: 250c.
                ("except" [*note expression: 182. ["as" *note identifier: 22aa.]] ":" *note suite: 250c.)+
                ["else" ":" *note suite: 250c.]
                ["finally" ":" *note suite: 250c.]
     try2_stmt: "try" ":" *note suite: 250c.
                ("except" "*" *note expression: 182. ["as" *note identifier: 22aa.] ":" *note suite: 250c.)+
                ["else" ":" *note suite: 250c.]
                ["finally" ":" *note suite: 250c.]
     try3_stmt: "try" ":" *note suite: 250c.
                "finally" ":" *note suite: 250c.

Additional information on exceptions can be found in section *note
Exceptions: 2417, and information on using the *note raise: 804.
statement to generate exceptions may be found in section *note The raise
statement: 804.

Cambiato nella versione 3.14: Support for optionally dropping grouping
parentheses when using multiple exception types.  See PEP 758(1).

* Menu:

* except clause::
* except* clause::
* else clause::
* finally clause::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0758/


File: python.info,  Node: except clause,  Next: except* clause,  Up: The try statement

4.8.4.1 ‘except’ clause
.......................

The ‘except’ clause(s) specify one or more exception handlers.  When no
exception occurs in the *note try: 8f9. clause, no exception handler is
executed.  When an exception occurs in the ‘try’ suite, a search for an
exception handler is started.  This search inspects the ‘except’ clauses
in turn until one is found that matches the exception.  An
expression-less ‘except’ clause, if present, must be last; it matches
any exception.

For an ‘except’ clause with an expression, the expression must evaluate
to an exception type or a tuple of exception types.  Parentheses can be
dropped if multiple exception types are provided and the ‘as’ clause is
not used.  The raised exception matches an ‘except’ clause whose
expression evaluates to the class or a *note non-virtual base class:
13be. of the exception object, or to a tuple that contains such a class.

If no ‘except’ clause matches the exception, the search for an exception
handler continues in the surrounding code and on the invocation stack.
(1)

If the evaluation of an expression in the header of an ‘except’ clause
raises an exception, the original search for a handler is canceled and a
search starts for the new exception in the surrounding code and on the
call stack (it is treated as if the entire *note try: 8f9. statement
raised the exception).

When a matching ‘except’ clause is found, the exception is assigned to
the target specified after the ‘as’ keyword in that ‘except’ clause, if
present, and the ‘except’ clause’s suite is executed.  All ‘except’
clauses must have an executable block.  When the end of this block is
reached, execution continues normally after the entire *note try: 8f9.
statement.  (This means that if two nested handlers exist for the same
exception, and the exception occurs in the ‘try’ clause of the inner
handler, the outer handler will not handle the exception.)

When an exception has been assigned using ‘as target’, it is cleared at
the end of the ‘except’ clause.  This is as if

     except E as N:
         foo

was translated to

     except E as N:
         try:
             foo
         finally:
             del N

This means the exception must be assigned to a different name to be able
to refer to it after the ‘except’ clause.  Exceptions are cleared
because with the traceback attached to them, they form a reference cycle
with the stack frame, keeping all locals in that frame alive until the
next garbage collection occurs.

Before an ‘except’ clause’s suite is executed, the exception is stored
in the *note sys: df. module, where it can be accessed from within the
body of the ‘except’ clause by calling *note sys.exception(): 89c.  When
leaving an exception handler, the exception stored in the *note sys: df.
module is reset to its previous value:

     >>> print(sys.exception())
     None
     >>> try:
     ...     raise TypeError
     ... except:
     ...     print(repr(sys.exception()))
     ...     try:
     ...          raise ValueError
     ...     except:
     ...         print(repr(sys.exception()))
     ...     print(repr(sys.exception()))
     ...
     TypeError()
     ValueError()
     TypeError()
     >>> print(sys.exception())
     None

   ---------- Footnotes ----------

   (1) The exception is propagated to the invocation stack unless there
is a *note finally: 1b0. clause which happens to raise another
exception.  That new exception causes the old one to be lost.


File: python.info,  Node: except* clause,  Next: else clause,  Prev: except clause,  Up: The try statement

4.8.4.2 ‘except*’ clause
........................

The ‘except*’ clause(s) specify one or more handlers for groups of
exceptions (*note BaseExceptionGroup: 566. instances).  A *note try:
8f9. statement can have either *note except: 1ab. or ‘except*’ clauses,
but not both.  The exception type for matching is mandatory in the case
of ‘except*’, so ‘except*:’ is a syntax error.  The type is interpreted
as in the case of ‘except’, but matching is performed on the exceptions
contained in the group that is being handled.  An *note TypeError: 198.
is raised if a matching type is a subclass of ‘BaseExceptionGroup’,
because that would have ambiguous semantics.

When an exception group is raised in the try block, each ‘except*’
clause splits (see *note split(): 18c0.) it into the subgroups of
matching and non-matching exceptions.  If the matching subgroup is not
empty, it becomes the handled exception (the value returned from *note
sys.exception(): 89c.) and assigned to the target of the ‘except*’
clause (if there is one).  Then, the body of the ‘except*’ clause
executes.  If the non-matching subgroup is not empty, it is processed by
the next ‘except*’ in the same manner.  This continues until all
exceptions in the group have been matched, or the last ‘except*’ clause
has run.

After all ‘except*’ clauses execute, the group of unhandled exceptions
is merged with any exceptions that were raised or re-raised from within
‘except*’ clauses.  This merged exception group propagates on.:

     >>> try:
     ...     raise ExceptionGroup("eg",
     ...         [ValueError(1), TypeError(2), OSError(3), OSError(4)])
     ... except* TypeError as e:
     ...     print(f'caught {type(e)} with nested {e.exceptions}')
     ... except* OSError as e:
     ...     print(f'caught {type(e)} with nested {e.exceptions}')
     ...
     caught <class 'ExceptionGroup'> with nested (TypeError(2),)
     caught <class 'ExceptionGroup'> with nested (OSError(3), OSError(4))
       + Exception Group Traceback (most recent call last):
       |   File "<doctest default[0]>", line 2, in <module>
       |     raise ExceptionGroup("eg",
       |         [ValueError(1), TypeError(2), OSError(3), OSError(4)])
       | ExceptionGroup: eg (1 sub-exception)
       +-+---------------- 1 ----------------
         | ValueError: 1
         +------------------------------------

If the exception raised from the *note try: 8f9. block is not an
exception group and its type matches one of the ‘except*’ clauses, it is
caught and wrapped by an exception group with an empty message string.
This ensures that the type of the target ‘e’ is consistently *note
BaseExceptionGroup: 566.:

     >>> try:
     ...     raise BlockingIOError
     ... except* BlockingIOError as e:
     ...     print(repr(e))
     ...
     ExceptionGroup('', (BlockingIOError(),))

*note break: 17f, *note continue: 180. and *note return: 1af. cannot
appear in an ‘except*’ clause.


File: python.info,  Node: else clause,  Next: finally clause,  Prev: except* clause,  Up: The try statement

4.8.4.3 ‘else’ clause
.....................

The optional ‘else’ clause is executed if the control flow leaves the
*note try: 8f9. suite, no exception was raised, and no *note return:
1af, *note continue: 180, or *note break: 17f. statement was executed.
Exceptions in the ‘else’ clause are not handled by the preceding *note
except: 1ab. clauses.


File: python.info,  Node: finally clause,  Prev: else clause,  Up: The try statement

4.8.4.4 ‘finally’ clause
........................

If ‘finally’ is present, it specifies a “cleanup” handler.  The *note
try: 8f9. clause is executed, including any *note except: 1ab. and *note
else: 2519. clauses.  If an exception occurs in any of the clauses and
is not handled, the exception is temporarily saved.  The ‘finally’
clause is executed.  If there is a saved exception it is re-raised at
the end of the ‘finally’ clause.  If the ‘finally’ clause raises another
exception, the saved exception is set as the context of the new
exception.  If the ‘finally’ clause executes a *note return: 1af, *note
break: 17f. or *note continue: 180. statement, the saved exception is
discarded.  For example, this function returns 42.

     def f():
         try:
             1/0
         finally:
             return 42

The exception information is not available to the program during
execution of the ‘finally’ clause.

When a *note return: 1af, *note break: 17f. or *note continue: 180.
statement is executed in the *note try: 8f9. suite of a ‘try’…‘finally’
statement, the ‘finally’ clause is also executed “on the way out.”

The return value of a function is determined by the last *note return:
1af. statement executed.  Since the ‘finally’ clause always executes, a
‘return’ statement executed in the ‘finally’ clause will always be the
last one executed.  The following function returns “finally”.

     def foo():
         try:
             return 'try'
         finally:
             return 'finally'

Cambiato nella versione 3.8: Prior to Python 3.8, a *note continue: 180.
statement was illegal in the ‘finally’ clause due to a problem with the
implementation.

Cambiato nella versione 3.14: The compiler emits a *note SyntaxWarning:
1ae. when a *note return: 1af, *note break: 17f. or *note continue: 180.
appears in a ‘finally’ block (see PEP 765(1)).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0765/


File: python.info,  Node: The with statement,  Next: The match statement,  Prev: The try statement,  Up: Compound statements

4.8.5 The ‘with’ statement
--------------------------

The *note with: 186. statement is used to wrap the execution of a block
with methods defined by a context manager (see section *note With
Statement Context Managers: 23ee.).  This allows common *note try:
8f9.…*note except: 1ab.…*note finally: 1b0. usage patterns to be
encapsulated for convenient reuse.

     with_stmt:          "with" ( "(" *note with_stmt_contents: 251d. ","? ")" | *note with_stmt_contents: 251d. ) ":" *note suite: 250c.
     with_stmt_contents: *note with_item: 251e. ("," *note with_item: 251e.)*
     with_item:          *note expression: 182. ["as" *note target: 24e1.]

The execution of the *note with: 186. statement with one «item» proceeds
as follows:

  1. The context expression (the expression given in the *note
     with_item: 251e.) is evaluated to obtain a context manager.

  2. The context manager’s *note __enter__(): 7e5. is loaded for later
     use.

  3. The context manager’s *note __exit__(): 1508. is loaded for later
     use.

  4. The context manager’s *note __enter__(): 7e5. method is invoked.

  5. If a target was included in the *note with: 186. statement, the
     return value from *note __enter__(): 7e5. is assigned to it.

          Nota: The *note with: 186. statement guarantees that if the
          *note __enter__(): 7e5. method returns without an error, then
          *note __exit__(): 1508. will always be called.  Thus, if an
          error occurs during the assignment to the target list, it will
          be treated the same as an error occurring within the suite
          would be.  See step 7 below.

  6. The suite is executed.

  7. The context manager’s *note __exit__(): 1508. method is invoked.
     If an exception caused the suite to be exited, its type, value, and
     traceback are passed as arguments to *note __exit__(): 1508.
     Otherwise, three *note None: 886. arguments are supplied.

     If the suite was exited due to an exception, and the return value
     from the *note __exit__(): 1508. method was false, the exception is
     reraised.  If the return value was true, the exception is
     suppressed, and execution continues with the statement following
     the *note with: 186. statement.

     If the suite was exited for any reason other than an exception, the
     return value from *note __exit__(): 1508. is ignored, and execution
     proceeds at the normal location for the kind of exit that was
     taken.

The following code:

     with EXPRESSION as TARGET:
         SUITE

is semantically equivalent to:

     manager = (EXPRESSION)
     enter = type(manager).__enter__
     exit = type(manager).__exit__
     value = enter(manager)
     hit_except = False

     try:
         TARGET = value
         SUITE
     except:
         hit_except = True
         if not exit(manager, *sys.exc_info()):
             raise
     finally:
         if not hit_except:
             exit(manager, None, None, None)

With more than one item, the context managers are processed as if
multiple *note with: 186. statements were nested:

     with A() as a, B() as b:
         SUITE

is semantically equivalent to:

     with A() as a:
         with B() as b:
             SUITE

You can also write multi-item context managers in multiple lines if the
items are surrounded by parentheses.  For example:

     with (
         A() as a,
         B() as b,
     ):
         SUITE

Cambiato nella versione 3.1: Support for multiple context expressions.

Cambiato nella versione 3.10: Support for using grouping parentheses to
break the statement in multiple lines.

Vedi anche
..........

PEP 343(1) - The «with» statement

     The specification, background, and examples for the Python *note
     with: 186. statement.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0343/


File: python.info,  Node: The match statement,  Next: Function definitions,  Prev: The with statement,  Up: Compound statements

4.8.6 The ‘match’ statement
---------------------------

Added in version 3.10.

The match statement is used for pattern matching.  Syntax:

     match_stmt:   'match' *note subject_expr: 2521. ":" NEWLINE INDENT *note case_block: 2522.+ DEDENT
     subject_expr: `!star_named_expression` "," `!star_named_expressions`?
                   | `!named_expression`
     case_block:   'case' *note patterns: 2523. [*note guard: 2524.] ":" `!block`

     Nota: This section uses single quotes to denote *note soft
     keywords: a0f.

Pattern matching takes a pattern as input (following ‘case’) and a
subject value (following ‘match’).  The pattern (which may contain
subpatterns) is matched against the subject value.  The outcomes are:

   * A match success or failure (also termed a pattern success or
     failure).

   * Possible binding of matched values to a name.  The prerequisites
     for this are further discussed below.

The ‘match’ and ‘case’ keywords are *note soft keywords: a0f.

Vedi anche
..........

   * PEP 634(1) – Structural Pattern Matching: Specification

   * PEP 636(2) – Structural Pattern Matching: Tutorial

* Menu:

* Overview::
* Guards::
* Irrefutable Case Blocks::
* Patterns::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0634/

   (2) https://peps.python.org/pep-0636/


File: python.info,  Node: Overview,  Next: Guards,  Up: The match statement

4.8.6.1 Overview
................

Here’s an overview of the logical flow of a match statement:

  1. The subject expression ‘subject_expr’ is evaluated and a resulting
     subject value obtained.  If the subject expression contains a
     comma, a tuple is constructed using *note the standard rules: 2526.

  2. Each pattern in a ‘case_block’ is attempted to match with the
     subject value.  The specific rules for success or failure are
     described below.  The match attempt can also bind some or all of
     the standalone names within the pattern.  The precise pattern
     binding rules vary per pattern type and are specified below.  'Name
     bindings made during a successful pattern match outlive the
     executed block and can be used after the match statement'.

          Nota: During failed pattern matches, some subpatterns may
          succeed.  Do not rely on bindings being made for a failed
          match.  Conversely, do not rely on variables remaining
          unchanged after a failed match.  The exact behavior is
          dependent on implementation and may vary.  This is an
          intentional decision made to allow different implementations
          to add optimizations.

  3. If the pattern succeeds, the corresponding guard (if present) is
     evaluated.  In this case all name bindings are guaranteed to have
     happened.

        * If the guard evaluates as true or is missing, the ‘block’
          inside ‘case_block’ is executed.

        * Otherwise, the next ‘case_block’ is attempted as described
          above.

        * If there are no further case blocks, the match statement is
          completed.

     Nota: Users should generally never rely on a pattern being
     evaluated.  Depending on implementation, the interpreter may cache
     values or use other optimizations which skip repeated evaluations.

A sample match statement:

     >>> flag = False
     >>> match (100, 200):
     ...    case (100, 300):  # Mismatch: 200 != 300
     ...        print('Case 1')
     ...    case (100, 200) if flag:  # Successful match, but guard fails
     ...        print('Case 2')
     ...    case (100, y):  # Matches and binds y to 200
     ...        print(f'Case 3, y: {y}')
     ...    case _:  # Pattern not attempted
     ...        print('Case 4, I match anything!')
     ...
     Case 3, y: 200

In this case, ‘if flag’ is a guard.  Read more about that in the next
section.


File: python.info,  Node: Guards,  Next: Irrefutable Case Blocks,  Prev: Overview,  Up: The match statement

4.8.6.2 Guards
..............

     guard: "if" `!named_expression`

A ‘guard’ (which is part of the ‘case’) must succeed for code inside the
‘case’ block to execute.  It takes the form: *note if: 181. followed by
an expression.

The logical flow of a ‘case’ block with a ‘guard’ follows:

  1. Check that the pattern in the ‘case’ block succeeded.  If the
     pattern failed, the ‘guard’ is not evaluated and the next ‘case’
     block is checked.

  2. If the pattern succeeded, evaluate the ‘guard’.

        * If the ‘guard’ condition evaluates as true, the case block is
          selected.

        * If the ‘guard’ condition evaluates as false, the case block is
          not selected.

        * If the ‘guard’ raises an exception during evaluation, the
          exception bubbles up.

Guards are allowed to have side effects as they are expressions.  Guard
evaluation must proceed from the first to the last case block, one at a
time, skipping case blocks whose pattern(s) don’t all succeed.  (I.e.,
guard evaluation must happen in order.)  Guard evaluation must stop once
a case block is selected.


File: python.info,  Node: Irrefutable Case Blocks,  Next: Patterns,  Prev: Guards,  Up: The match statement

4.8.6.3 Irrefutable Case Blocks
...............................

An irrefutable case block is a match-all case block.  A match statement
may have at most one irrefutable case block, and it must be last.

A case block is considered irrefutable if it has no guard and its
pattern is irrefutable.  A pattern is considered irrefutable if we can
prove from its syntax alone that it will always succeed.  Only the
following patterns are irrefutable:

   * *note AS Patterns: 252a. whose left-hand side is irrefutable

   * *note OR Patterns: 252b. containing at least one irrefutable
     pattern

   * *note Capture Patterns: 252c.

   * *note Wildcard Patterns: a11.

   * parenthesized irrefutable patterns


File: python.info,  Node: Patterns,  Prev: Irrefutable Case Blocks,  Up: The match statement

4.8.6.4 Patterns
................

     Nota: This section uses grammar notations beyond standard EBNF:

        * the notation ‘SEP.RULE+’ is shorthand for ‘RULE (SEP RULE)*’

        * the notation ‘!RULE’ is shorthand for a negative lookahead
          assertion

The top-level syntax for ‘patterns’ is:

     patterns:       *note open_sequence_pattern: 252e. | *note pattern: 252f.
     pattern:        *note as_pattern: 2530. | *note or_pattern: 2531.
     closed_pattern: | *note literal_pattern: 2533.
                     | *note capture_pattern: 2534.
                     | *note wildcard_pattern: 2535.
                     | *note value_pattern: 2536.
                     | *note group_pattern: 2537.
                     | *note sequence_pattern: 2538.
                     | *note mapping_pattern: 2539.
                     | *note class_pattern: 253a.

The descriptions below will include a description «in simple terms» of
what a pattern does for illustration purposes (credits to Raymond
Hettinger for a document that inspired most of the descriptions).  Note
that these descriptions are purely for illustration purposes and 'may
not' reflect the underlying implementation.  Furthermore, they do not
cover all valid forms.

* Menu:

* OR Patterns::
* AS Patterns::
* Literal Patterns::
* Capture Patterns::
* Wildcard Patterns::
* Value Patterns::
* Group Patterns::
* Sequence Patterns::
* Mapping Patterns::
* Class Patterns::


File: python.info,  Node: OR Patterns,  Next: AS Patterns,  Up: Patterns

4.8.6.5 OR Patterns
...................

An OR pattern is two or more patterns separated by vertical bars ‘|’.
Syntax:

     or_pattern: "|".*note closed_pattern: 2532.+

Only the final subpattern may be *note irrefutable: 2528, and each
subpattern must bind the same set of names to avoid ambiguity.

An OR pattern matches each of its subpatterns in turn to the subject
value, until one succeeds.  The OR pattern is then considered
successful.  Otherwise, if none of the subpatterns succeed, the OR
pattern fails.

In simple terms, ‘P1 | P2 | ...’ will try to match ‘P1’, if it fails it
will try to match ‘P2’, succeeding immediately if any succeeds, failing
otherwise.


File: python.info,  Node: AS Patterns,  Next: Literal Patterns,  Prev: OR Patterns,  Up: Patterns

4.8.6.6 AS Patterns
...................

An AS pattern matches an OR pattern on the left of the *note as: 251b.
keyword against a subject.  Syntax:

     as_pattern: *note or_pattern: 2531. "as" *note capture_pattern: 2534.

If the OR pattern fails, the AS pattern fails.  Otherwise, the AS
pattern binds the subject to the name on the right of the as keyword and
succeeds.  ‘capture_pattern’ cannot be a ‘_’.

In simple terms ‘P as NAME’ will match with ‘P’, and on success it will
set ‘NAME = <subject>’.


File: python.info,  Node: Literal Patterns,  Next: Capture Patterns,  Prev: AS Patterns,  Up: Patterns

4.8.6.7 Literal Patterns
........................

A literal pattern corresponds to most *note literals: 22b2. in Python.
Syntax:

     literal_pattern: *note signed_number: 253f.
                      | *note signed_number: 253f. "+" NUMBER
                      | *note signed_number: 253f. "-" NUMBER
                      | *note strings: 245b.
                      | "None"
                      | "True"
                      | "False"
     signed_number:   ["-"] NUMBER

The rule ‘strings’ and the token ‘NUMBER’ are defined in the *note
standard Python grammar: 2540.  Triple-quoted strings are supported.
Raw strings and byte strings are supported.  *note f-strings: 19a. and
*note t-strings: 17e2. are not supported.

The forms ‘signed_number '+' NUMBER’ and ‘signed_number '-' NUMBER’ are
for expressing *note complex numbers: 2304.; they require a real number
on the left and an imaginary number on the right.  E.g.  ‘3 + 4j’.

In simple terms, ‘LITERAL’ will succeed only if ‘<subject> == LITERAL’.
For the singletons ‘None’, ‘True’ and ‘False’, the *note is: 34c.
operator is used.


File: python.info,  Node: Capture Patterns,  Next: Wildcard Patterns,  Prev: Literal Patterns,  Up: Patterns

4.8.6.8 Capture Patterns
........................

A capture pattern binds the subject value to a name.  Syntax:

     capture_pattern: !'_' NAME

A single underscore ‘_’ is not a capture pattern (this is what ‘!'_'’
expresses).  It is instead treated as a *note wildcard_pattern: 2535.

In a given pattern, a given name can only be bound once.  E.g.  ‘case x,
x: ...’ is invalid while ‘case [x] | x: ...’ is allowed.

Capture patterns always succeed.  The binding follows scoping rules
established by the assignment expression operator in PEP 572(1); the
name becomes a local variable in the closest containing function scope
unless there’s an applicable *note global: 4ad. or *note nonlocal: 14af.
statement.

In simple terms ‘NAME’ will always succeed and it will set ‘NAME =
<subject>’.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0572/


File: python.info,  Node: Wildcard Patterns,  Next: Value Patterns,  Prev: Capture Patterns,  Up: Patterns

4.8.6.9 Wildcard Patterns
.........................

A wildcard pattern always succeeds (matches anything) and binds no name.
Syntax:

     wildcard_pattern: '_'

‘_’ is a *note soft keyword: a0f. within any pattern, but only within
patterns.  It is an identifier, as usual, even within ‘match’ subject
expressions, ‘guard’s, and ‘case’ blocks.

In simple terms, ‘_’ will always succeed.


File: python.info,  Node: Value Patterns,  Next: Group Patterns,  Prev: Wildcard Patterns,  Up: Patterns

4.8.6.10 Value Patterns
.......................

A value pattern represents a named value in Python.  Syntax:

     value_pattern: *note attr: 2545.
     attr:          *note name_or_attr: 2546. "." NAME
     name_or_attr:  *note attr: 2545. | NAME

The dotted name in the pattern is looked up using standard Python *note
name resolution rules: 240e.  The pattern succeeds if the value found
compares equal to the subject value (using the ‘==’ equality operator).

In simple terms ‘NAME1.NAME2’ will succeed only if ‘<subject> ==
NAME1.NAME2’

     Nota: If the same value occurs multiple times in the same match
     statement, the interpreter may cache the first value found and
     reuse it rather than repeat the same lookup.  This cache is
     strictly tied to a given execution of a given match statement.


File: python.info,  Node: Group Patterns,  Next: Sequence Patterns,  Prev: Value Patterns,  Up: Patterns

4.8.6.11 Group Patterns
.......................

A group pattern allows users to add parentheses around patterns to
emphasize the intended grouping.  Otherwise, it has no additional
syntax.  Syntax:

     group_pattern: "(" *note pattern: 252f. ")"

In simple terms ‘(P)’ has the same effect as ‘P’.


File: python.info,  Node: Sequence Patterns,  Next: Mapping Patterns,  Prev: Group Patterns,  Up: Patterns

4.8.6.12 Sequence Patterns
..........................

A sequence pattern contains several subpatterns to be matched against
sequence elements.  The syntax is similar to the unpacking of a list or
tuple.

     sequence_pattern:       "[" [*note maybe_sequence_pattern: 254b.] "]"
                             | "(" [*note open_sequence_pattern: 252e.] ")"
     open_sequence_pattern:  *note maybe_star_pattern: 254c. "," [*note maybe_sequence_pattern: 254b.]
     maybe_sequence_pattern: ",".*note maybe_star_pattern: 254c.+ ","?
     maybe_star_pattern:     *note star_pattern: 254d. | *note pattern: 252f.
     star_pattern:           "*" (*note capture_pattern: 2534. | *note wildcard_pattern: 2535.)

There is no difference if parentheses or square brackets are used for
sequence patterns (i.e.  ‘(...)’ vs ‘[...]’ ).

     Nota: A single pattern enclosed in parentheses without a trailing
     comma (e.g.  ‘(3 | 4)’) is a *note group pattern: 2547.  While a
     single pattern enclosed in square brackets (e.g.  ‘[3 | 4]’) is
     still a sequence pattern.

At most one star subpattern may be in a sequence pattern.  The star
subpattern may occur in any position.  If no star subpattern is present,
the sequence pattern is a fixed-length sequence pattern; otherwise it is
a variable-length sequence pattern.

The following is the logical flow for matching a sequence pattern
against a subject value:

  1. If the subject value is not a sequence (1), the sequence pattern
     fails.

  2. If the subject value is an instance of ‘str’, ‘bytes’ or
     ‘bytearray’ the sequence pattern fails.

  3. The subsequent steps depend on whether the sequence pattern is
     fixed or variable-length.

     If the sequence pattern is fixed-length:

       1. If the length of the subject sequence is not equal to the
          number of subpatterns, the sequence pattern fails

       2. Subpatterns in the sequence pattern are matched to their
          corresponding items in the subject sequence from left to
          right.  Matching stops as soon as a subpattern fails.  If all
          subpatterns succeed in matching their corresponding item, the
          sequence pattern succeeds.

     Otherwise, if the sequence pattern is variable-length:

       1. If the length of the subject sequence is less than the number
          of non-star subpatterns, the sequence pattern fails.

       2. The leading non-star subpatterns are matched to their
          corresponding items as for fixed-length sequences.

       3. If the previous step succeeds, the star subpattern matches a
          list formed of the remaining subject items, excluding the
          remaining items corresponding to non-star subpatterns
          following the star subpattern.

       4. Remaining non-star subpatterns are matched to their
          corresponding subject items, as for a fixed-length sequence.

          Nota: The length of the subject sequence is obtained via *note
          len(): 841. (i.e.  via the *note __len__(): 1777. protocol).
          This length may be cached by the interpreter in a similar
          manner as *note value patterns: 2544.

In simple terms ‘[P1, P2, P3,’ … ‘, P<N>]’ matches only if all the
following happens:

   * check ‘<subject>’ is a sequence

   * ‘len(subject) == <N>’

   * ‘P1’ matches ‘<subject>[0]’ (note that this match can also bind
     names)

   * ‘P2’ matches ‘<subject>[1]’ (note that this match can also bind
     names)

   * … and so on for the corresponding pattern/element.

   ---------- Footnotes ----------

   (1) In pattern matching, a sequence is defined as one of the
following:

   * a class that inherits from *note collections.abc.Sequence: 13cc.

   * a Python class that has been registered as *note
     collections.abc.Sequence: 13cc.

   * a builtin class that has its (CPython) *note Py_TPFLAGS_SEQUENCE:
     1c41. bit set

   * a class that inherits from any of the above

The following standard library classes are sequences:

   * *note array.array: 4bf.

   * *note collections.deque: 7f5.

   * *note list: 24d.

   * *note memoryview: 165.

   * *note range: b3f.

   * *note tuple: 614.

     Nota: Subject values of type ‘str’, ‘bytes’, and ‘bytearray’ do not
     match sequence patterns.


File: python.info,  Node: Mapping Patterns,  Next: Class Patterns,  Prev: Sequence Patterns,  Up: Patterns

4.8.6.13 Mapping Patterns
.........................

A mapping pattern contains one or more key-value patterns.  The syntax
is similar to the construction of a dictionary.  Syntax:

     mapping_pattern:     "{" [*note items_pattern: 2550.] "}"
     items_pattern:       ",".*note key_value_pattern: 2551.+ ","?
     key_value_pattern:   (*note literal_pattern: 2533. | *note value_pattern: 2536.) ":" *note pattern: 252f.
                          | *note double_star_pattern: 2552.
     double_star_pattern: "**" *note capture_pattern: 2534.

At most one double star pattern may be in a mapping pattern.  The double
star pattern must be the last subpattern in the mapping pattern.

Duplicate keys in mapping patterns are disallowed.  Duplicate literal
keys will raise a *note SyntaxError: 18e.  Two keys that otherwise have
the same value will raise a *note ValueError: 2ec. at runtime.

The following is the logical flow for matching a mapping pattern against
a subject value:

  1. If the subject value is not a mapping (1),the mapping pattern
     fails.

  2. If every key given in the mapping pattern is present in the subject
     mapping, and the pattern for each key matches the corresponding
     item of the subject mapping, the mapping pattern succeeds.

  3. If duplicate keys are detected in the mapping pattern, the pattern
     is considered invalid.  A *note SyntaxError: 18e. is raised for
     duplicate literal values; or a *note ValueError: 2ec. for named
     keys of the same value.

     Nota: Key-value pairs are matched using the two-argument form of
     the mapping subject’s ‘get()’ method.  Matched key-value pairs must
     already be present in the mapping, and not created on-the-fly via
     *note __missing__(): 13c5. or *note __getitem__(): 588.

In simple terms ‘{KEY1: P1, KEY2: P2, ... }’ matches only if all the
following happens:

   * check ‘<subject>’ is a mapping

   * ‘KEY1 in <subject>’

   * ‘P1’ matches ‘<subject>[KEY1]’

   * … and so on for the corresponding KEY/pattern pair.

   ---------- Footnotes ----------

   (1) In pattern matching, a mapping is defined as one of the
following:

   * a class that inherits from *note collections.abc.Mapping: ac9.

   * a Python class that has been registered as *note
     collections.abc.Mapping: ac9.

   * a builtin class that has its (CPython) *note Py_TPFLAGS_MAPPING:
     1c40. bit set

   * a class that inherits from any of the above

The standard library classes *note dict: 183. and *note
types.MappingProxyType: 699. are mappings.


File: python.info,  Node: Class Patterns,  Prev: Mapping Patterns,  Up: Patterns

4.8.6.14 Class Patterns
.......................

A class pattern represents a class and its positional and keyword
arguments (if any).  Syntax:

     class_pattern:       *note name_or_attr: 2546. "(" [*note pattern_arguments: 2555. ","?] ")"
     pattern_arguments:   *note positional_patterns: 2556. ["," *note keyword_patterns: 2557.]
                          | *note keyword_patterns: 2557.
     positional_patterns: ",".*note pattern: 252f.+
     keyword_patterns:    ",".*note keyword_pattern: 2558.+
     keyword_pattern:     NAME "=" *note pattern: 252f.

The same keyword should not be repeated in class patterns.

The following is the logical flow for matching a class pattern against a
subject value:

  1. If ‘name_or_attr’ is not an instance of the builtin *note type:
     f46. , raise *note TypeError: 198.

  2. If the subject value is not an instance of ‘name_or_attr’ (tested
     via *note isinstance(): 2ad.), the class pattern fails.

  3. If no pattern arguments are present, the pattern succeeds.
     Otherwise, the subsequent steps depend on whether keyword or
     positional argument patterns are present.

     For a number of built-in types (specified below), a single
     positional subpattern is accepted which will match the entire
     subject; for these types keyword patterns also work as for other
     types.

     If only keyword patterns are present, they are processed as
     follows, one by one:

       1. The keyword is looked up as an attribute on the subject.

             * If this raises an exception other than *note
               AttributeError: 5f0, the exception bubbles up.

             * If this raises *note AttributeError: 5f0, the class
               pattern has failed.

             * Else, the subpattern associated with the keyword pattern
               is matched against the subject’s attribute value.  If
               this fails, the class pattern fails; if this succeeds,
               the match proceeds to the next keyword.

       2. If all keyword patterns succeed, the class pattern succeeds.

     If any positional patterns are present, they are converted to
     keyword patterns using the *note __match_args__: 1c5d. attribute on
     the class ‘name_or_attr’ before matching:

       1. The equivalent of ‘getattr(cls, "__match_args__", ())’ is
          called.

             * If this raises an exception, the exception bubbles up.

             * If the returned value is not a tuple, the conversion
               fails and *note TypeError: 198. is raised.

             * If there are more positional patterns than
               ‘len(cls.__match_args__)’, *note TypeError: 198. is
               raised.

             * Otherwise, positional pattern ‘i’ is converted to a
               keyword pattern using ‘__match_args__[i]’ as the keyword.
               ‘__match_args__[i]’ must be a string; if not *note
               TypeError: 198. is raised.

             * If there are duplicate keywords, *note TypeError: 198. is
               raised.

          Vedi anche
          ..........

          *note Customizing positional arguments in class pattern
          matching: 23f1.

       2. Once all positional patterns have been converted to keyword
          patterns, the match proceeds as if there were only keyword
          patterns.

     For the following built-in types the handling of positional
     subpatterns is different:

        * *note bool: 3c3.

        * *note bytearray: 344.

        * *note bytes: 192.

        * *note dict: 183.

        * *note float: 196.

        * *note frozenset: 7f3.

        * *note int: 19b.

        * *note list: 24d.

        * *note set: 184.

        * *note str: 169.

        * *note tuple: 614.

     These classes accept a single positional argument, and the pattern
     there is matched against the whole object rather than an attribute.
     For example ‘int(0|1)’ matches the value ‘0’, but not the value
     ‘0.0’.

In simple terms ‘CLS(P1, attr=P2)’ matches only if the following
happens:

   * ‘isinstance(<subject>, CLS)’

   * convert ‘P1’ to a keyword pattern using ‘CLS.__match_args__’

   * For each keyword argument ‘attr=P2’:

        * ‘hasattr(<subject>, "attr")’

        * ‘P2’ matches ‘<subject>.attr’

   * … and so on for the corresponding keyword argument/pattern pair.

Vedi anche
..........

   * PEP 634(1) – Structural Pattern Matching: Specification

   * PEP 636(2) – Structural Pattern Matching: Tutorial

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0634/

   (2) https://peps.python.org/pep-0636/


File: python.info,  Node: Function definitions,  Next: Class definitions,  Prev: The match statement,  Up: Compound statements

4.8.7 Function definitions
--------------------------

A function definition defines a user-defined function object (see
section *note The standard type hierarchy: 2318.):

     funcdef:                   [*note decorators: 255a.] "def" *note funcname: 255b. [*note type_params: 24fb.] "(" [*note parameter_list: 24bf.] ")"
                                ["->" *note expression: 182.] ":" *note suite: 250c.
     decorators:                *note decorator: 255c.+
     decorator:                 "@" *note assignment_expression: 2411. NEWLINE
     parameter_list:            *note defparameter: 255d. ("," *note defparameter: 255d.)* "," "/" ["," [*note parameter_list_no_posonly: 255e.]]
                                  | *note parameter_list_no_posonly: 255e.
     parameter_list_no_posonly: *note defparameter: 255d. ("," *note defparameter: 255d.)* ["," [*note parameter_list_starargs: 255f.]]
                                | *note parameter_list_starargs: 255f.
     parameter_list_starargs:   "*" [*note star_parameter: 2560.] ("," *note defparameter: 255d.)* ["," [*note parameter_star_kwargs: 2561.]]
                                | "*" ("," *note defparameter: 255d.)+ ["," [*note parameter_star_kwargs: 2561.]]
                                | *note parameter_star_kwargs: 2561.
     parameter_star_kwargs:     "**" *note parameter: 2562. [","]
     parameter:                 *note identifier: 22aa. [":" *note expression: 182.]
     star_parameter:            *note identifier: 22aa. [":" ["*"] *note expression: 182.]
     defparameter:              *note parameter: 2562. ["=" *note expression: 182.]
     funcname:                  *note identifier: 22aa.

A function definition is an executable statement.  Its execution binds
the function name in the current local namespace to a function object (a
wrapper around the executable code for the function).  This function
object contains a reference to the current global namespace as the
global namespace to be used when the function is called.

The function definition does not execute the function body; this gets
executed only when the function is called.  (1)

A function definition may be wrapped by one or more *note decorator:
93b. expressions.  Decorator expressions are evaluated when the function
is defined, in the scope that contains the function definition.  The
result must be a callable, which is invoked with the function object as
the only argument.  The returned value is bound to the function name
instead of the function object.  Multiple decorators are applied in
nested fashion.  For example, the following code

     @f1(arg)
     @f2
     def func(): pass

is roughly equivalent to

     def func(): pass
     func = f1(arg)(f2(func))

except that the original function is not temporarily bound to the name
‘func’.

Cambiato nella versione 3.9: Functions may be decorated with any valid
*note assignment_expression: 2411.  Previously, the grammar was much
more restrictive; see PEP 614(2) for details.

A list of *note type parameters: 5ad. may be given in square brackets
between the function’s name and the opening parenthesis for its
parameter list.  This indicates to static type checkers that the
function is generic.  At runtime, the type parameters can be retrieved
from the function’s *note __type_params__: 2334. attribute.  See *note
Generic functions: 683. for more.

Cambiato nella versione 3.12: Type parameter lists are new in Python
3.12.

When one or more *note parameters: 2332. have the form 'parameter' ‘=’
'expression', the function is said to have «default parameter values.»
For a parameter with a default value, the corresponding *note argument:
67b. may be omitted from a call, in which case the parameter’s default
value is substituted.  If a parameter has a default value, all following
parameters up until the «‘*’» must also have a default value — this is a
syntactic restriction that is not expressed by the grammar.

'Default parameter values are evaluated from left to right when the
function definition is executed.'  This means that the expression is
evaluated once, when the function is defined, and that the same
«pre-computed» value is used for each call.  This is especially
important to understand when a default parameter value is a mutable
object, such as a list or a dictionary: if the function modifies the
object (e.g.  by appending an item to a list), the default parameter
value is in effect modified.  This is generally not what was intended.
A way around this is to use ‘None’ as the default, and explicitly test
for it in the body of the function, e.g.:

     def whats_on_the_telly(penguin=None):
         if penguin is None:
             penguin = []
         penguin.append("property of the zoo")
         return penguin

Function call semantics are described in more detail in section *note
Calls: f7f.  A function call always assigns values to all parameters
mentioned in the parameter list, either from positional arguments, from
keyword arguments, or from default values.  If the form «‘*identifier’»
is present, it is initialized to a tuple receiving any excess positional
parameters, defaulting to the empty tuple.  If the form «‘**identifier’»
is present, it is initialized to a new ordered mapping receiving any
excess keyword arguments, defaulting to a new empty mapping of the same
type.  Parameters after «‘*’» or «‘*identifier’» are keyword-only
parameters and may only be passed by keyword arguments.  Parameters
before «‘/’» are positional-only parameters and may only be passed by
positional arguments.

Cambiato nella versione 3.8: The ‘/’ function parameter syntax may be
used to indicate positional-only parameters.  See PEP 570(3) for
details.

Parameters may have an *note annotation: 2003. of the form «‘:
expression’» following the parameter name.  Any parameter may have an
annotation, even those of the form ‘*identifier’ or ‘**identifier’.  (As
a special case, parameters of the form ‘*identifier’ may have an
annotation «‘: *expression’».)  Functions may have «return» annotation
of the form «‘-> expression’» after the parameter list.  These
annotations can be any valid Python expression.  The presence of
annotations does not change the semantics of a function.  See *note
Annotations: 2563. for more information on annotations.

Cambiato nella versione 3.11: Parameters of the form «‘*identifier’» may
have an annotation «‘: *expression’».  See PEP 646(4).

It is also possible to create anonymous functions (functions not bound
to a name), for immediate use in expressions.  This uses lambda
expressions, described in section *note Lambdas: 14a5.  Note that the
lambda expression is merely a shorthand for a simplified function
definition; a function defined in a «*note def: 1661.» statement can be
passed around or assigned to another name just like a function defined
by a lambda expression.  The «‘def’» form is actually more powerful
since it allows the execution of multiple statements and annotations.

'Programmer’s note:' Functions are first-class objects.  A «‘def’»
statement executed inside a function definition defines a local function
that can be returned or passed around.  Free variables used in the
nested function can access the local variables of the function
containing the def.  See section *note Naming and binding: 232d. for
details.

Vedi anche
..........

PEP 3107(5) - Function Annotations

     The original specification for function annotations.

PEP 484(6) - Type Hints

     Definition of a standard meaning for annotations: type hints.

PEP 526(7) - Syntax for Variable Annotations

     Ability to type hint variable declarations, including class
     variables and instance variables.

PEP 563(8) - Postponed Evaluation of Annotations

     Support for forward references within annotations by preserving
     annotations in a string form at runtime instead of eager
     evaluation.

PEP 318(9) - Decorators for Functions and Methods

     Function and method decorators were introduced.  Class decorators
     were introduced in PEP 3129(10).

   ---------- Footnotes ----------

   (1) A string literal appearing as the first statement in the function
body is transformed into the function’s *note __doc__: 13e1. attribute
and therefore the function’s *note docstring: 22d5.

   (2) https://peps.python.org/pep-0614/

   (3) https://peps.python.org/pep-0570/

   (4) https://peps.python.org/pep-0646/

   (5) https://peps.python.org/pep-3107/

   (6) https://peps.python.org/pep-0484/

   (7) https://peps.python.org/pep-0526/

   (8) https://peps.python.org/pep-0563/

   (9) https://peps.python.org/pep-0318/

   (10) https://peps.python.org/pep-3129/


File: python.info,  Node: Class definitions,  Next: Coroutines<2>,  Prev: Function definitions,  Up: Compound statements

4.8.8 Class definitions
-----------------------

A class definition defines a class object (see section *note The
standard type hierarchy: 2318.):

     classdef:    [*note decorators: 255a.] "class" *note classname: 2565. [*note type_params: 24fb.] [*note inheritance: 2566.] ":" *note suite: 250c.
     inheritance: "(" [*note argument_list: 2492.] ")"
     classname:   *note identifier: 22aa.

A class definition is an executable statement.  The inheritance list
usually gives a list of base classes (see *note Metaclasses: 23a4. for
more advanced uses), so each item in the list should evaluate to a class
object which allows subclassing.  Classes without an inheritance list
inherit, by default, from the base class *note object: c80.; hence,

     class Foo:
         pass

is equivalent to

     class Foo(object):
         pass

The class’s suite is then executed in a new execution frame (see *note
Naming and binding: 232d.), using a newly created local namespace and
the original global namespace.  (Usually, the suite contains mostly
function definitions.)  When the class’s suite finishes execution, its
execution frame is discarded but its local namespace is saved.  (1)  A
class object is then created using the inheritance list for the base
classes and the saved local namespace for the attribute dictionary.  The
class name is bound to this class object in the original local
namespace.

The order in which attributes are defined in the class body is preserved
in the new class’s *note __dict__: e59.  Note that this is reliable only
right after the class is created and only for classes that were defined
using the definition syntax.

Class creation can be customized heavily using *note metaclasses: 23a4.

Classes can also be decorated: just like when decorating functions,

     @f1(arg)
     @f2
     class Foo: pass

is roughly equivalent to

     class Foo: pass
     Foo = f1(arg)(f2(Foo))

The evaluation rules for the decorator expressions are the same as for
function decorators.  The result is then bound to the class name.

Cambiato nella versione 3.9: Classes may be decorated with any valid
*note assignment_expression: 2411.  Previously, the grammar was much
more restrictive; see PEP 614(2) for details.

A list of *note type parameters: 5ad. may be given in square brackets
immediately after the class’s name.  This indicates to static type
checkers that the class is generic.  At runtime, the type parameters can
be retrieved from the class’s *note __type_params__: 235d. attribute.
See *note Generic classes: 682. for more.

Cambiato nella versione 3.12: Type parameter lists are new in Python
3.12.

'Programmer’s note:' Variables defined in the class definition are class
attributes; they are shared by instances.  Instance attributes can be
set in a method with ‘self.name = value’.  Both class and instance
attributes are accessible through the notation «‘self.name’», and an
instance attribute hides a class attribute with the same name when
accessed in this way.  Class attributes can be used as defaults for
instance attributes, but using mutable values there can lead to
unexpected results.  *note Descriptors: e4b. can be used to create
instance variables with different implementation details.

Vedi anche
..........

PEP 3115(3) - Metaclasses in Python 3000

     The proposal that changed the declaration of metaclasses to the
     current syntax, and the semantics for how classes with metaclasses
     are constructed.

PEP 3129(4) - Class Decorators

     The proposal that added class decorators.  Function and method
     decorators were introduced in PEP 318(5).

   ---------- Footnotes ----------

   (1) A string literal appearing as the first statement in the class
body is transformed into the namespace’s *note __doc__: 207f. item and
therefore the class’s *note docstring: 22d5.

   (2) https://peps.python.org/pep-0614/

   (3) https://peps.python.org/pep-3115/

   (4) https://peps.python.org/pep-3129/

   (5) https://peps.python.org/pep-0318/


File: python.info,  Node: Coroutines<2>,  Next: Type parameter lists,  Prev: Class definitions,  Up: Compound statements

4.8.9 Coroutines
----------------

Added in version 3.5.

* Menu:

* Coroutine function definition::
* The async for statement::
* The async with statement::


File: python.info,  Node: Coroutine function definition,  Next: The async for statement,  Up: Coroutines<2>

4.8.9.1 Coroutine function definition
.....................................

     async_funcdef: [*note decorators: 255a.] "async" "def" *note funcname: 255b. "(" [*note parameter_list: 24bf.] ")"
                    ["->" *note expression: 182.] ":" *note suite: 250c.

Execution of Python coroutines can be suspended and resumed at many
points (see *note coroutine: 6ba.).  *note await: 18d. expressions,
*note async for: ca3. and *note async with: 185. can only be used in the
body of a coroutine function.

Functions defined with ‘async def’ syntax are always coroutine
functions, even if they do not contain ‘await’ or ‘async’ keywords.

It is a *note SyntaxError: 18e. to use a ‘yield from’ expression inside
the body of a coroutine function.

An example of a coroutine function:

     async def func(param1, param2):
         do_stuff()
         await some_coroutine()

Cambiato nella versione 3.7: ‘await’ and ‘async’ are now keywords;
previously they were only treated as such inside the body of a coroutine
function.


File: python.info,  Node: The async for statement,  Next: The async with statement,  Prev: Coroutine function definition,  Up: Coroutines<2>

4.8.9.2 The ‘async for’ statement
.................................

     async_for_stmt: "async" *note for_stmt: 2503.

An *note asynchronous iterable: f76. provides an ‘__aiter__’ method that
directly returns an *note asynchronous iterator: 4c8, which can call
asynchronous code in its ‘__anext__’ method.

The ‘async for’ statement allows convenient iteration over asynchronous
iterables.

The following code:

     async for TARGET in ITER:
         SUITE
     else:
         SUITE2

Is semantically equivalent to:

     iter = (ITER)
     iter = type(iter).__aiter__(iter)
     running = True

     while running:
         try:
             TARGET = await type(iter).__anext__(iter)
         except StopAsyncIteration:
             running = False
         else:
             SUITE
     else:
         SUITE2

See also *note __aiter__(): df8. and *note __anext__(): 186a. for
details.

It is a *note SyntaxError: 18e. to use an ‘async for’ statement outside
the body of a coroutine function.


File: python.info,  Node: The async with statement,  Prev: The async for statement,  Up: Coroutines<2>

4.8.9.3 The ‘async with’ statement
..................................

     async_with_stmt: "async" *note with_stmt: 2505.

An *note asynchronous context manager: 7f1. is a *note context manager:
1e1. that is able to suspend execution in its 'enter' and 'exit'
methods.

The following code:

     async with EXPRESSION as TARGET:
         SUITE

is semantically equivalent to:

     manager = (EXPRESSION)
     aenter = type(manager).__aenter__
     aexit = type(manager).__aexit__
     value = await aenter(manager)
     hit_except = False

     try:
         TARGET = value
         SUITE
     except:
         hit_except = True
         if not await aexit(manager, *sys.exc_info()):
             raise
     finally:
         if not hit_except:
             await aexit(manager, None, None, None)

See also *note __aenter__(): 2401. and *note __aexit__(): 1989. for
details.

It is a *note SyntaxError: 18e. to use an ‘async with’ statement outside
the body of a coroutine function.

Vedi anche
..........

PEP 492(1) - Coroutines with async and await syntax

     The proposal that made coroutines a proper standalone concept in
     Python, and added supporting syntax.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0492/


File: python.info,  Node: Type parameter lists,  Next: Annotations<2>,  Prev: Coroutines<2>,  Up: Compound statements

4.8.10 Type parameter lists
---------------------------

Added in version 3.12.

Cambiato nella versione 3.13: Support for default values was added (see
PEP 696(1)).

     type_params:  "[" *note type_param: 256c. ("," *note type_param: 256c.)* "]"
     type_param:   *note typevar: 256d. | *note typevartuple: 256e. | *note paramspec: 256f.
     typevar:      *note identifier: 22aa. (":" *note expression: 182.)? ("=" *note expression: 182.)?
     typevartuple: "*" *note identifier: 22aa. ("=" *note expression: 182.)?
     paramspec:    "**" *note identifier: 22aa. ("=" *note expression: 182.)?

*note Functions: 1661. (including *note coroutines: 7ee.), *note
classes: 14df. and *note type aliases: 66d. may contain a type parameter
list:

     def max[T](args: list[T]) -> T:
         ...

     async def amax[T](args: list[T]) -> T:
         ...

     class Bag[T]:
         def __iter__(self) -> Iterator[T]:
             ...

         def add(self, arg: T) -> None:
             ...

     type ListOrSet[T] = list[T] | set[T]

Semantically, this indicates that the function, class, or type alias is
generic over a type variable.  This information is primarily used by
static type checkers, and at runtime, generic objects behave much like
their non-generic counterparts.

Type parameters are declared in square brackets (‘[]’) immediately after
the name of the function, class, or type alias.  The type parameters are
accessible within the scope of the generic object, but not elsewhere.
Thus, after a declaration ‘def func[T](): pass’, the name ‘T’ is not
available in the module scope.  Below, the semantics of generic objects
are described with more precision.  The scope of type parameters is
modeled with a special function (technically, an *note annotation scope:
4ac.) that wraps the creation of the generic object.

Generic functions, classes, and type aliases have a *note
__type_params__: 2570. attribute listing their type parameters.

Type parameters come in three kinds:

   * *note typing.TypeVar: 487, introduced by a plain name (e.g., ‘T’).
     Semantically, this represents a single type to a type checker.

   * *note typing.TypeVarTuple: 489, introduced by a name prefixed with
     a single asterisk (e.g., ‘*Ts’).  Semantically, this stands for a
     tuple of any number of types.

   * *note typing.ParamSpec: 488, introduced by a name prefixed with two
     asterisks (e.g., ‘**P’).  Semantically, this stands for the
     parameters of a callable.

*note typing.TypeVar: 487. declarations can define 'bounds' and
'constraints' with a colon (‘:’) followed by an expression.  A single
expression after the colon indicates a bound (e.g.  ‘T: int’).
Semantically, this means that the ‘typing.TypeVar’ can only represent
types that are a subtype of this bound.  A parenthesized tuple of
expressions after the colon indicates a set of constraints (e.g.  ‘T:
(str, bytes)’).  Each member of the tuple should be a type (again, this
is not enforced at runtime).  Constrained type variables can only take
on one of the types in the list of constraints.

For ‘typing.TypeVar’s declared using the type parameter list syntax, the
bound and constraints are not evaluated when the generic object is
created, but only when the value is explicitly accessed through the
attributes ‘__bound__’ and ‘__constraints__’.  To accomplish this, the
bounds or constraints are evaluated in a separate *note annotation
scope: 4ac.

*note typing.TypeVarTuple: 489.s and *note typing.ParamSpec: 488.s
cannot have bounds or constraints.

All three flavors of type parameters can also have a 'default value',
which is used when the type parameter is not explicitly provided.  This
is added by appending a single equals sign (‘=’) followed by an
expression.  Like the bounds and constraints of type variables, the
default value is not evaluated when the object is created, but only when
the type parameter’s ‘__default__’ attribute is accessed.  To this end,
the default value is evaluated in a separate *note annotation scope:
4ac.  If no default value is specified for a type parameter, the
‘__default__’ attribute is set to the special sentinel object *note
typing.NoDefault: 569.

The following example indicates the full set of allowed type parameter
declarations:

     def overly_generic[
        SimpleTypeVar,
        TypeVarWithDefault = int,
        TypeVarWithBound: int,
        TypeVarWithConstraints: (str, bytes),
        *SimpleTypeVarTuple = (int, float),
        **SimpleParamSpec = (str, bytearray),
     ](
        a: SimpleTypeVar,
        b: TypeVarWithDefault,
        c: TypeVarWithBound,
        d: Callable[SimpleParamSpec, TypeVarWithConstraints],
        *e: SimpleTypeVarTuple,
     ): ...

* Menu:

* Generic functions::
* Generic classes::
* Generic type aliases::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0696/


File: python.info,  Node: Generic functions,  Next: Generic classes,  Up: Type parameter lists

4.8.10.1 Generic functions
..........................

Generic functions are declared as follows:

     def func[T](arg: T): ...

This syntax is equivalent to:

     annotation-def TYPE_PARAMS_OF_func():
         T = typing.TypeVar("T")
         def func(arg: T): ...
         func.__type_params__ = (T,)
         return func
     func = TYPE_PARAMS_OF_func()

Here ‘annotation-def’ indicates an *note annotation scope: 4ac, which is
not actually bound to any name at runtime.  (One other liberty is taken
in the translation: the syntax does not go through attribute access on
the *note typing: 10a. module, but creates an instance of *note
typing.TypeVar: 487. directly.)

The annotations of generic functions are evaluated within the annotation
scope used for declaring the type parameters, but the function’s
defaults and decorators are not.

The following example illustrates the scoping rules for these cases, as
well as for additional flavors of type parameters:

     @decorator
     def func[T: int, *Ts, **P](*args: *Ts, arg: Callable[P, T] = some_default):
         ...

Except for the *note lazy evaluation: 686. of the *note TypeVar: 487.
bound, this is equivalent to:

     DEFAULT_OF_arg = some_default

     annotation-def TYPE_PARAMS_OF_func():

         annotation-def BOUND_OF_T():
             return int
         # In reality, BOUND_OF_T() is evaluated only on demand.
         T = typing.TypeVar("T", bound=BOUND_OF_T())

         Ts = typing.TypeVarTuple("Ts")
         P = typing.ParamSpec("P")

         def func(*args: *Ts, arg: Callable[P, T] = DEFAULT_OF_arg):
             ...

         func.__type_params__ = (T, Ts, P)
         return func
     func = decorator(TYPE_PARAMS_OF_func())

The capitalized names like ‘DEFAULT_OF_arg’ are not actually bound at
runtime.


File: python.info,  Node: Generic classes,  Next: Generic type aliases,  Prev: Generic functions,  Up: Type parameter lists

4.8.10.2 Generic classes
........................

Generic classes are declared as follows:

     class Bag[T]: ...

This syntax is equivalent to:

     annotation-def TYPE_PARAMS_OF_Bag():
         T = typing.TypeVar("T")
         class Bag(typing.Generic[T]):
             __type_params__ = (T,)
             ...
         return Bag
     Bag = TYPE_PARAMS_OF_Bag()

Here again ‘annotation-def’ (not a real keyword) indicates an *note
annotation scope: 4ac, and the name ‘TYPE_PARAMS_OF_Bag’ is not actually
bound at runtime.

Generic classes implicitly inherit from *note typing.Generic: 179e.  The
base classes and keyword arguments of generic classes are evaluated
within the type scope for the type parameters, and decorators are
evaluated outside that scope.  This is illustrated by this example:

     @decorator
     class Bag(Base[T], arg=T): ...

This is equivalent to:

     annotation-def TYPE_PARAMS_OF_Bag():
         T = typing.TypeVar("T")
         class Bag(Base[T], typing.Generic[T], arg=T):
             __type_params__ = (T,)
             ...
         return Bag
     Bag = decorator(TYPE_PARAMS_OF_Bag())


File: python.info,  Node: Generic type aliases,  Prev: Generic classes,  Up: Type parameter lists

4.8.10.3 Generic type aliases
.............................

The *note type: 66d. statement can also be used to create a generic type
alias:

     type ListOrSet[T] = list[T] | set[T]

Except for the *note lazy evaluation: 686. of the value, this is
equivalent to:

     annotation-def TYPE_PARAMS_OF_ListOrSet():
         T = typing.TypeVar("T")

         annotation-def VALUE_OF_ListOrSet():
             return list[T] | set[T]
         # In reality, the value is lazily evaluated
         return typing.TypeAliasType("ListOrSet", VALUE_OF_ListOrSet(), type_params=(T,))
     ListOrSet = TYPE_PARAMS_OF_ListOrSet()

Here, ‘annotation-def’ (not a real keyword) indicates an *note
annotation scope: 4ac.  The capitalized names like
‘TYPE_PARAMS_OF_ListOrSet’ are not actually bound at runtime.


File: python.info,  Node: Annotations<2>,  Prev: Type parameter lists,  Up: Compound statements

4.8.11 Annotations
------------------

Cambiato nella versione 3.14: Annotations are now lazily evaluated by
default.

Variables and function parameters may carry *note annotations: 15c,
created by adding a colon after the name, followed by an expression:

     x: annotation = 1
     def f(param: annotation): ...

Functions may also carry a return annotation following an arrow:

     def f() -> annotation: ...

Annotations are conventionally used for *note type hints: 23b1, but this
is not enforced by the language, and in general annotations may contain
arbitrary expressions.  The presence of annotations does not change the
runtime semantics of the code, except if some mechanism is used that
introspects and uses the annotations (such as *note dataclasses: 33. or
*note functools.singledispatch(): 84c.).

By default, annotations are lazily evaluated in an *note annotation
scope: 4ac.  This means that they are not evaluated when the code
containing the annotation is evaluated.  Instead, the interpreter saves
information that can be used to evaluate the annotation later if
requested.  The *note annotationlib: 6. module provides tools for
evaluating annotations.

If the *note future statement: 45d. ‘from __future__ import annotations’
is present, all annotations are instead stored as strings:

     >>> from __future__ import annotations
     >>> def f(param: annotation): ...
     >>> f.__annotations__
     {'param': 'annotation'}

This future statement will be deprecated and removed in a future version
of Python, but not before Python 3.13 reaches its end of life (see PEP
749(1)).  When it is used, introspection tools like *note
annotationlib.get_annotations(): 459. and *note typing.get_type_hints():
8c1. are less likely to be able to resolve annotations at runtime.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0749/


File: python.info,  Node: Top-level components,  Next: Full Grammar specification,  Prev: Compound statements,  Up: The Python Language Reference

4.9 Top-level components
========================

The Python interpreter can get its input from a number of sources: from
a script passed to it as standard input or as program argument, typed in
interactively, from a module source file, etc.  This chapter gives the
syntax used in these cases.

* Menu:

* Complete Python programs::
* File input::
* Interactive input::
* Expression input::


File: python.info,  Node: Complete Python programs,  Next: File input,  Up: Top-level components

4.9.1 Complete Python programs
------------------------------

While a language specification need not prescribe how the language
interpreter is invoked, it is useful to have a notion of a complete
Python program.  A complete Python program is executed in a minimally
initialized environment: all built-in and standard modules are
available, but none have been initialized, except for *note sys: df.
(various system services), *note builtins: 13. (built-in functions,
exceptions and ‘None’) and *note __main__: 1.  The latter is used to
provide the local and global namespace for execution of the complete
program.

The syntax for a complete Python program is that for file input,
described in the next section.

The interpreter may also be invoked in interactive mode; in this case,
it does not read and execute a complete program but reads and executes
one statement (possibly compound) at a time.  The initial environment is
identical to that of a complete program; each statement is executed in
the namespace of *note __main__: 1.

A complete program can be passed to the interpreter in three forms: with
the *note -c: 1a8. 'string' command line option, as a file passed as the
first command line argument, or as standard input.  If the file or
standard input is a tty device, the interpreter enters interactive mode;
otherwise, it executes the file as a complete program.


File: python.info,  Node: File input,  Next: Interactive input,  Prev: Complete Python programs,  Up: Top-level components

4.9.2 File input
----------------

All input read from non-interactive files has the same form:

     file_input: (NEWLINE | *note statement: 250e.)* ENDMARKER

This syntax is used in the following situations:

   * when parsing a complete Python program (from a file or from a
     string);

   * when parsing a module;

   * when parsing a string passed to the *note exec(): 4a3. function;


File: python.info,  Node: Interactive input,  Next: Expression input,  Prev: File input,  Up: Top-level components

4.9.3 Interactive input
-----------------------

Input in interactive mode is parsed using the following grammar:

     interactive_input: [*note stmt_list: 250d.] NEWLINE | *note compound_stmt: 2500. NEWLINE | ENDMARKER

Note that a (top-level) compound statement must be followed by a blank
line in interactive mode; this is needed to help the parser detect the
end of the input.


File: python.info,  Node: Expression input,  Prev: Interactive input,  Up: Top-level components

4.9.4 Expression input
----------------------

*note eval(): 4a4. is used for expression input.  It ignores leading
whitespace.  The string argument to *note eval(): 4a4. must have the
following form:

     eval_input: *note expression_list: 24c3. NEWLINE* ENDMARKER


File: python.info,  Node: Full Grammar specification,  Prev: Top-level components,  Up: The Python Language Reference

4.10 Full Grammar specification
===============================

This is the full Python grammar, derived directly from the grammar used
to generate the CPython parser (see Grammar/python.gram(1)).  The
version here omits details related to code generation and error
recovery.

The notation used here is the same as in the preceding docs, and is
described in the *note notation: 226d. section, except for an extra
complication:

   * ‘~’ («cut»): commit to the current alternative; fail the rule if
     the alternative fails to parse

     Python mainly uses cuts for optimizations or improved error
     messages.  They often appear to be useless in the listing below.

     Cuts currently don’t appear inside parentheses, brackets,
     lookaheads and similar.  Their behavior in these contexts is
     deliberately left unspecified.

     # PEG grammar for Python

     @trailer '''
     void *
     _PyPegen_parse(Parser *p)
     {
         // Initialize keywords
         p->keywords = reserved_keywords;
         p->n_keyword_lists = n_keyword_lists;
         p->soft_keywords = soft_keywords;

         // Run parser
         void *result = NULL;
         if (p->start_rule == Py_file_input) {
             result = file_rule(p);
         } else if (p->start_rule == Py_single_input) {
             result = interactive_rule(p);
         } else if (p->start_rule == Py_eval_input) {
             result = eval_rule(p);
         } else if (p->start_rule == Py_func_type_input) {
             result = func_type_rule(p);
         }

         return result;
     }
     '''

     # ========================= START OF THE GRAMMAR =========================

     # General grammatical elements and rules:
     #
     # * Strings with double quotes (") denote SOFT KEYWORDS
     # * Strings with single quotes (') denote KEYWORDS
     # * Upper case names (NAME) denote tokens in the Grammar/Tokens file
     # * Rule names starting with "invalid_" are used for specialized syntax errors
     #     - These rules are NOT used in the first pass of the parser.
     #     - Only if the first pass fails to parse, a second pass including the invalid
     #       rules will be executed.
     #     - If the parser fails in the second phase with a generic syntax error, the
     #       location of the generic failure of the first pass will be used (this avoids
     #       reporting incorrect locations due to the invalid rules).
     #     - The order of the alternatives involving invalid rules matter
     #       (like any rule in PEG).
     #
     # Grammar Syntax (see PEP 617 for more information):
     #
     # rule_name: expression
     #   Optionally, a type can be included right after the rule name, which
     #   specifies the return type of the C or Python function corresponding to the
     #   rule:
     # rule_name[return_type]: expression
     #   If the return type is omitted, then a void * is returned in C and an Any in
     #   Python.
     # e1 e2
     #   Match e1, then match e2.
     # e1 | e2
     #   Match e1 or e2.
     #   The first alternative can also appear on the line after the rule name for
     #   formatting purposes. In that case, a | must be used before the first
     #   alternative, like so:
     #       rule_name[return_type]:
     #            | first_alt
     #            | second_alt
     # ( e )
     #   Match e (allows also to use other operators in the group like '(e)*')
     # [ e ] or e?
     #   Optionally match e.
     # e*
     #   Match zero or more occurrences of e.
     # e+
     #   Match one or more occurrences of e.
     # s.e+
     #   Match one or more occurrences of e, separated by s. The generated parse tree
     #   does not include the separator. This is otherwise identical to (e (s e)*).
     # &e
     #   Succeed if e can be parsed, without consuming any input.
     # !e
     #   Fail if e can be parsed, without consuming any input.
     # ~
     #   Commit to the current alternative, even if it fails to parse.
     # &&e
     #   Eager parse e. The parser will not backtrack and will immediately
     #   fail with SyntaxError if e cannot be parsed.
     #

     # STARTING RULES
     # ==============

     file[mod_ty]: a=[statements] ENDMARKER { _PyPegen_make_module(p, a) }
     interactive[mod_ty]: a=statement_newline { _PyAST_Interactive(a, p->arena) }
     eval[mod_ty]: a=expressions NEWLINE* ENDMARKER { _PyAST_Expression(a, p->arena) }
     func_type[mod_ty]: '(' a=[type_expressions] ')' '->' b=expression NEWLINE* ENDMARKER { _PyAST_FunctionType(a, b, p->arena) }

     # GENERAL STATEMENTS
     # ==================

     statements[asdl_stmt_seq*]: a=statement+ { (asdl_stmt_seq*)_PyPegen_seq_flatten(p, a) }

     statement[asdl_stmt_seq*]:
         | a=compound_stmt { _PyPegen_register_stmts(p ,
                                (asdl_stmt_seq*)_PyPegen_singleton_seq(p, a)
                             ) }
         | a[asdl_stmt_seq*]=simple_stmts { a }

     single_compound_stmt[asdl_stmt_seq*]:
         | a=compound_stmt {
             _PyPegen_register_stmts(p, (asdl_stmt_seq*)_PyPegen_singleton_seq(p, a)) }

     statement_newline[asdl_stmt_seq*]:
         | a=single_compound_stmt NEWLINE { a }
         | simple_stmts
         | NEWLINE { (asdl_stmt_seq*)_PyPegen_singleton_seq(p, CHECK(stmt_ty, _PyAST_Pass(EXTRA))) }
         | ENDMARKER { _PyPegen_interactive_exit(p) }

     simple_stmts[asdl_stmt_seq*]:
         | a=simple_stmt !';' NEWLINE { (asdl_stmt_seq*)_PyPegen_singleton_seq(p, a) } # Not needed, there for speedup
         | a[asdl_stmt_seq*]=';'.simple_stmt+ [';'] NEWLINE { a }

     # NOTE: assignment MUST precede expression, else parsing a simple assignment
     # will throw a SyntaxError.
     simple_stmt[stmt_ty] (memo):
         | assignment
         | &"type" type_alias
         | e=star_expressions { _PyAST_Expr(e, EXTRA) }
         | &'return' return_stmt
         | &('import' | 'from') import_stmt
         | &'raise' raise_stmt
         | &'pass' pass_stmt
         | &'del' del_stmt
         | &'yield' yield_stmt
         | &'assert' assert_stmt
         | &'break' break_stmt
         | &'continue' continue_stmt
         | &'global' global_stmt
         | &'nonlocal' nonlocal_stmt

     compound_stmt[stmt_ty]:
         | &('def' | '@' | 'async') function_def
         | &'if' if_stmt
         | &('class' | '@') class_def
         | &('with' | 'async') with_stmt
         | &('for' | 'async') for_stmt
         | &'try' try_stmt
         | &'while' while_stmt
         | match_stmt

     # SIMPLE STATEMENTS
     # =================

     # NOTE: annotated_rhs may start with 'yield'; yield_expr must start with 'yield'
     assignment[stmt_ty]:
         | a=NAME ':' b=expression c=['=' d=annotated_rhs { d }] {
             CHECK_VERSION(
                 stmt_ty,
                 6,
                 "Variable annotation syntax is",
                 _PyAST_AnnAssign(CHECK(expr_ty, _PyPegen_set_expr_context(p, a, Store)), b, c, 1, EXTRA)
             ) }
         | a=('(' b=single_target ')' { b }
              | single_subscript_attribute_target) ':' b=expression c=['=' d=annotated_rhs { d }] {
             CHECK_VERSION(stmt_ty, 6, "Variable annotations syntax is", _PyAST_AnnAssign(a, b, c, 0, EXTRA)) }
         | a[asdl_expr_seq*]=(z=star_targets '=' { z })+ b=annotated_rhs !'=' tc=[TYPE_COMMENT] {
              _PyAST_Assign(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) }
         | a=single_target b=augassign ~ c=annotated_rhs {
              _PyAST_AugAssign(a, b->kind, c, EXTRA) }
         | invalid_assignment

     annotated_rhs[expr_ty]: yield_expr | star_expressions

     augassign[AugOperator*]:
         | '+=' { _PyPegen_augoperator(p, Add) }
         | '-=' { _PyPegen_augoperator(p, Sub) }
         | '*=' { _PyPegen_augoperator(p, Mult) }
         | '@=' { CHECK_VERSION(AugOperator*, 5, "The '@' operator is", _PyPegen_augoperator(p, MatMult)) }
         | '/=' { _PyPegen_augoperator(p, Div) }
         | '%=' { _PyPegen_augoperator(p, Mod) }
         | '&=' { _PyPegen_augoperator(p, BitAnd) }
         | '|=' { _PyPegen_augoperator(p, BitOr) }
         | '^=' { _PyPegen_augoperator(p, BitXor) }
         | '<<=' { _PyPegen_augoperator(p, LShift) }
         | '>>=' { _PyPegen_augoperator(p, RShift) }
         | '**=' { _PyPegen_augoperator(p, Pow) }
         | '//=' { _PyPegen_augoperator(p, FloorDiv) }

     return_stmt[stmt_ty]:
         | 'return' a=[star_expressions] { _PyAST_Return(a, EXTRA) }

     raise_stmt[stmt_ty]:
         | 'raise' a=expression b=['from' z=expression { z }] { _PyAST_Raise(a, b, EXTRA) }
         | 'raise' { _PyAST_Raise(NULL, NULL, EXTRA) }

     pass_stmt[stmt_ty]:
         | 'pass' { _PyAST_Pass(EXTRA) }

     break_stmt[stmt_ty]:
         | 'break' { _PyAST_Break(EXTRA) }

     continue_stmt[stmt_ty]:
         | 'continue' { _PyAST_Continue(EXTRA) }

     global_stmt[stmt_ty]: 'global' a[asdl_expr_seq*]=','.NAME+ {
         _PyAST_Global(CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p, a)), EXTRA) }

     nonlocal_stmt[stmt_ty]: 'nonlocal' a[asdl_expr_seq*]=','.NAME+ {
         _PyAST_Nonlocal(CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p, a)), EXTRA) }

     del_stmt[stmt_ty]:
         | 'del' a=del_targets &(';' | NEWLINE) { _PyAST_Delete(a, EXTRA) }
         | invalid_del_stmt

     yield_stmt[stmt_ty]: y=yield_expr { _PyAST_Expr(y, EXTRA) }

     assert_stmt[stmt_ty]: 'assert' a=expression b=[',' z=expression { z }] { _PyAST_Assert(a, b, EXTRA) }

     import_stmt[stmt_ty]:
         | invalid_import
         | import_name
         | import_from

     # Import statements
     # -----------------

     import_name[stmt_ty]: 'import' a=dotted_as_names { _PyAST_Import(a, EXTRA) }
     # note below: the ('.' | '...') is necessary because '...' is tokenized as ELLIPSIS
     import_from[stmt_ty]:
         | 'from' a=('.' | '...')* b=dotted_name 'import' c=import_from_targets {
             _PyPegen_checked_future_import(p, b->v.Name.id, c, _PyPegen_seq_count_dots(a), EXTRA) }
         | 'from' a=('.' | '...')+ 'import' b=import_from_targets {
             _PyAST_ImportFrom(NULL, b, _PyPegen_seq_count_dots(a), EXTRA) }
     import_from_targets[asdl_alias_seq*]:
         | '(' a=import_from_as_names [','] ')' { a }
         | import_from_as_names !','
         | '*' { (asdl_alias_seq*)_PyPegen_singleton_seq(p, CHECK(alias_ty, _PyPegen_alias_for_star(p, EXTRA))) }
         | invalid_import_from_targets
     import_from_as_names[asdl_alias_seq*]:
         | a[asdl_alias_seq*]=','.import_from_as_name+ { a }
     import_from_as_name[alias_ty]:
         | invalid_import_from_as_name
         | a=NAME b=['as' z=NAME { z }] { _PyAST_alias(
             a->v.Name.id, (b) ? ((expr_ty) b)->v.Name.id : NULL, EXTRA) }

     dotted_as_names[asdl_alias_seq*]:
         | a[asdl_alias_seq*]=','.dotted_as_name+ { a }
     dotted_as_name[alias_ty]:
         | invalid_dotted_as_name
         | a=dotted_name b=['as' z=NAME { z }] { _PyAST_alias(
             a->v.Name.id, (b) ? ((expr_ty) b)->v.Name.id : NULL, EXTRA) }

     dotted_name[expr_ty]:
         | a=dotted_name '.' b=NAME { _PyPegen_join_names_with_dot(p, a, b) }
         | NAME

     # COMPOUND STATEMENTS
     # ===================

     # Common elements
     # ---------------

     block[asdl_stmt_seq*] (memo):
         | NEWLINE INDENT a=statements DEDENT { a }
         | simple_stmts
         | invalid_block

     decorators[asdl_expr_seq*]: a[asdl_expr_seq*]=('@' f=named_expression NEWLINE { f })+ { a }

     # Class definitions
     # -----------------

     class_def[stmt_ty]:
         | a=decorators b=class_def_raw { _PyPegen_class_def_decorators(p, a, b) }
         | class_def_raw

     class_def_raw[stmt_ty]:
         | invalid_class_def_raw
         | 'class' a=NAME t=[type_params] b=['(' z=[arguments] ')' { z }] ':' c=block {
             _PyAST_ClassDef(a->v.Name.id,
                          (b) ? ((expr_ty) b)->v.Call.args : NULL,
                          (b) ? ((expr_ty) b)->v.Call.keywords : NULL,
                          c, NULL, t, EXTRA) }

     # Function definitions
     # --------------------

     function_def[stmt_ty]:
         | d=decorators f=function_def_raw { _PyPegen_function_def_decorators(p, d, f) }
         | function_def_raw

     function_def_raw[stmt_ty]:
         | invalid_def_raw
         | 'def' n=NAME t=[type_params] '(' params=[params] ')' a=['->' z=expression { z }] ':' tc=[func_type_comment] b=block {
             _PyAST_FunctionDef(n->v.Name.id,
                             (params) ? params : CHECK(arguments_ty, _PyPegen_empty_arguments(p)),
                             b, NULL, a, NEW_TYPE_COMMENT(p, tc), t, EXTRA) }
         | 'async' 'def' n=NAME t=[type_params] '(' params=[params] ')' a=['->' z=expression { z }] ':' tc=[func_type_comment] b=block {
             CHECK_VERSION(
                 stmt_ty,
                 5,
                 "Async functions are",
                 _PyAST_AsyncFunctionDef(n->v.Name.id,
                                 (params) ? params : CHECK(arguments_ty, _PyPegen_empty_arguments(p)),
                                 b, NULL, a, NEW_TYPE_COMMENT(p, tc), t, EXTRA)
             ) }

     # Function parameters
     # -------------------

     params[arguments_ty]:
         | invalid_parameters
         | parameters

     parameters[arguments_ty]:
         | a=slash_no_default b[asdl_arg_seq*]=param_no_default* c=param_with_default* d=[star_etc] {
             CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, a, NULL, b, c, d)) }
         | a=slash_with_default b=param_with_default* c=[star_etc] {
             CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, NULL, a, NULL, b, c)) }
         | a[asdl_arg_seq*]=param_no_default+ b=param_with_default* c=[star_etc] {
             _PyPegen_make_arguments(p, NULL, NULL, a, b, c) }
         | a=param_with_default+ b=[star_etc] { _PyPegen_make_arguments(p, NULL, NULL, NULL, a, b)}
         | a=star_etc { _PyPegen_make_arguments(p, NULL, NULL, NULL, NULL, a) }

     # Some duplication here because we can't write (',' | &')'),
     # which is because we don't support empty alternatives (yet).

     slash_no_default[asdl_arg_seq*]:
         | a[asdl_arg_seq*]=param_no_default+ '/' ',' { a }
         | a[asdl_arg_seq*]=param_no_default+ '/' &')' { a }
     slash_with_default[SlashWithDefault*]:
         | a=param_no_default* b=param_with_default+ '/' ',' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }
         | a=param_no_default* b=param_with_default+ '/' &')' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }

     star_etc[StarEtc*]:
         | invalid_star_etc
         | '*' a=param_no_default b=param_maybe_default* c=[kwds] {
             _PyPegen_star_etc(p, a, b, c) }
         | '*' a=param_no_default_star_annotation b=param_maybe_default* c=[kwds] {
             _PyPegen_star_etc(p, a, b, c) }
         | '*' ',' b=param_maybe_default+ c=[kwds] {
             _PyPegen_star_etc(p, NULL, b, c) }
         | a=kwds { _PyPegen_star_etc(p, NULL, NULL, a) }

     kwds[arg_ty]:
         | invalid_kwds
         | '**' a=param_no_default { a }

     # One parameter.  This *includes* a following comma and type comment.
     #
     # There are three styles:
     # - No default
     # - With default
     # - Maybe with default
     #
     # There are two alternative forms of each, to deal with type comments:
     # - Ends in a comma followed by an optional type comment
     # - No comma, optional type comment, must be followed by close paren
     # The latter form is for a final parameter without trailing comma.
     #

     param_no_default[arg_ty]:
         | a=param ',' tc=TYPE_COMMENT? { _PyPegen_add_type_comment_to_arg(p, a, tc) }
         | a=param tc=TYPE_COMMENT? &')' { _PyPegen_add_type_comment_to_arg(p, a, tc) }
     param_no_default_star_annotation[arg_ty]:
         | a=param_star_annotation ',' tc=TYPE_COMMENT? { _PyPegen_add_type_comment_to_arg(p, a, tc) }
         | a=param_star_annotation tc=TYPE_COMMENT? &')' { _PyPegen_add_type_comment_to_arg(p, a, tc) }
     param_with_default[NameDefaultPair*]:
         | a=param c=default ',' tc=TYPE_COMMENT? { _PyPegen_name_default_pair(p, a, c, tc) }
         | a=param c=default tc=TYPE_COMMENT? &')' { _PyPegen_name_default_pair(p, a, c, tc) }
     param_maybe_default[NameDefaultPair*]:
         | a=param c=default? ',' tc=TYPE_COMMENT? { _PyPegen_name_default_pair(p, a, c, tc) }
         | a=param c=default? tc=TYPE_COMMENT? &')' { _PyPegen_name_default_pair(p, a, c, tc) }
     param[arg_ty]: a=NAME b=annotation? { _PyAST_arg(a->v.Name.id, b, NULL, EXTRA) }
     param_star_annotation[arg_ty]: a=NAME b=star_annotation { _PyAST_arg(a->v.Name.id, b, NULL, EXTRA) }
     annotation[expr_ty]: ':' a=expression { a }
     star_annotation[expr_ty]: ':' a=star_expression { a }
     default[expr_ty]: '=' a=expression { a } | invalid_default

     # If statement
     # ------------

     if_stmt[stmt_ty]:
         | invalid_if_stmt
         | 'if' a=named_expression ':' b=block c=elif_stmt {
             _PyAST_If(a, b, CHECK(asdl_stmt_seq*, _PyPegen_singleton_seq(p, c)), EXTRA) }
         | 'if' a=named_expression ':' b=block c=[else_block] { _PyAST_If(a, b, c, EXTRA) }
     elif_stmt[stmt_ty]:
         | invalid_elif_stmt
         | 'elif' a=named_expression ':' b=block c=elif_stmt {
             _PyAST_If(a, b, CHECK(asdl_stmt_seq*, _PyPegen_singleton_seq(p, c)), EXTRA) }
         | 'elif' a=named_expression ':' b=block c=[else_block] { _PyAST_If(a, b, c, EXTRA) }
     else_block[asdl_stmt_seq*]:
         | invalid_else_stmt
         | 'else' &&':' b=block { b }

     # While statement
     # ---------------

     while_stmt[stmt_ty]:
         | invalid_while_stmt
         | 'while' a=named_expression ':' b=block c=[else_block] { _PyAST_While(a, b, c, EXTRA) }

     # For statement
     # -------------

     for_stmt[stmt_ty]:
         | invalid_for_stmt
         | 'for' t=star_targets 'in' ~ ex=star_expressions ':' tc=[TYPE_COMMENT] b=block el=[else_block] {
             _PyAST_For(t, ex, b, el, NEW_TYPE_COMMENT(p, tc), EXTRA) }
         | 'async' 'for' t=star_targets 'in' ~ ex=star_expressions ':' tc=[TYPE_COMMENT] b=block el=[else_block] {
             CHECK_VERSION(stmt_ty, 5, "Async for loops are", _PyAST_AsyncFor(t, ex, b, el, NEW_TYPE_COMMENT(p, tc), EXTRA)) }
         | invalid_for_target

     # With statement
     # --------------

     with_stmt[stmt_ty]:
         | invalid_with_stmt_indent
         | 'with' '(' a[asdl_withitem_seq*]=','.with_item+ ','? ')' ':' tc=[TYPE_COMMENT] b=block {
            _PyAST_With(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) }
         | 'with' a[asdl_withitem_seq*]=','.with_item+ ':' tc=[TYPE_COMMENT] b=block {
             _PyAST_With(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) }
         | 'async' 'with' '(' a[asdl_withitem_seq*]=','.with_item+ ','? ')' ':' b=block {
            CHECK_VERSION(stmt_ty, 5, "Async with statements are", _PyAST_AsyncWith(a, b, NULL, EXTRA)) }
         | 'async' 'with' a[asdl_withitem_seq*]=','.with_item+ ':' tc=[TYPE_COMMENT] b=block {
            CHECK_VERSION(stmt_ty, 5, "Async with statements are", _PyAST_AsyncWith(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA)) }
         | invalid_with_stmt

     with_item[withitem_ty]:
         | e=expression 'as' t=star_target &(',' | ')' | ':') { _PyAST_withitem(e, t, p->arena) }
         | invalid_with_item
         | e=expression { _PyAST_withitem(e, NULL, p->arena) }

     # Try statement
     # -------------

     try_stmt[stmt_ty]:
         | invalid_try_stmt
         | 'try' &&':' b=block f=finally_block { _PyAST_Try(b, NULL, NULL, f, EXTRA) }
         | 'try' &&':' b=block ex[asdl_excepthandler_seq*]=except_block+ el=[else_block] f=[finally_block] { _PyAST_Try(b, ex, el, f, EXTRA) }
         | 'try' &&':' b=block ex[asdl_excepthandler_seq*]=except_star_block+ el=[else_block] f=[finally_block] {
             CHECK_VERSION(stmt_ty, 11, "Exception groups are",
                           _PyAST_TryStar(b, ex, el, f, EXTRA)) }


     # Except statement
     # ----------------

     except_block[excepthandler_ty]:
         | invalid_except_stmt_indent
         | 'except' e=expression ':' b=block {
             _PyAST_ExceptHandler(e, NULL, b, EXTRA) }
         | 'except' e=expression 'as' t=NAME ':' b=block {
             _PyAST_ExceptHandler(e, ((expr_ty) t)->v.Name.id, b, EXTRA) }
         | 'except' e=expressions ':' b=block {
             CHECK_VERSION(
                 excepthandler_ty,
                 14,
                 "except expressions without parentheses are",
                 _PyAST_ExceptHandler(e, NULL, b, EXTRA)) }
         | 'except' ':' b=block { _PyAST_ExceptHandler(NULL, NULL, b, EXTRA) }
         | invalid_except_stmt
     except_star_block[excepthandler_ty]:
         | invalid_except_star_stmt_indent
         | 'except' '*' e=expression ':' b=block {
             _PyAST_ExceptHandler(e, NULL, b, EXTRA) }
         | 'except' '*' e=expression 'as' t=NAME ':' b=block {
             _PyAST_ExceptHandler(e, ((expr_ty) t)->v.Name.id, b, EXTRA) }
         | 'except' '*' e=expressions ':' b=block {
             CHECK_VERSION(
                 excepthandler_ty,
                 14,
                 "except expressions without parentheses are",
                 _PyAST_ExceptHandler(e,  NULL, b, EXTRA)) }
         | invalid_except_star_stmt
     finally_block[asdl_stmt_seq*]:
         | invalid_finally_stmt
         | 'finally' &&':' a=block { a }

     # Match statement
     # ---------------

     match_stmt[stmt_ty]:
         | "match" subject=subject_expr ':' NEWLINE INDENT cases[asdl_match_case_seq*]=case_block+ DEDENT {
             CHECK_VERSION(stmt_ty, 10, "Pattern matching is", _PyAST_Match(subject, cases, EXTRA)) }
         | invalid_match_stmt

     subject_expr[expr_ty]:
         | value=star_named_expression ',' values=star_named_expressions? {
             _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, value, values)), Load, EXTRA) }
         | named_expression

     case_block[match_case_ty]:
         | invalid_case_block
         | "case" pattern=patterns guard=guard? ':' body=block {
             _PyAST_match_case(pattern, guard, body, p->arena) }

     guard[expr_ty]: 'if' guard=named_expression { guard }

     patterns[pattern_ty]:
         | patterns[asdl_pattern_seq*]=open_sequence_pattern {
             _PyAST_MatchSequence(patterns, EXTRA) }
         | pattern

     pattern[pattern_ty]:
         | as_pattern
         | or_pattern

     as_pattern[pattern_ty]:
         | pattern=or_pattern 'as' target=pattern_capture_target {
             _PyAST_MatchAs(pattern, target->v.Name.id, EXTRA) }
         | invalid_as_pattern

     or_pattern[pattern_ty]:
         | patterns[asdl_pattern_seq*]='|'.closed_pattern+ {
             asdl_seq_LEN(patterns) == 1 ? asdl_seq_GET(patterns, 0) : _PyAST_MatchOr(patterns, EXTRA) }

     closed_pattern[pattern_ty] (memo):
         | literal_pattern
         | capture_pattern
         | wildcard_pattern
         | value_pattern
         | group_pattern
         | sequence_pattern
         | mapping_pattern
         | class_pattern

     # Literal patterns are used for equality and identity constraints
     literal_pattern[pattern_ty]:
         | value=signed_number !('+' | '-') { _PyAST_MatchValue(value, EXTRA) }
         | value=complex_number { _PyAST_MatchValue(value, EXTRA) }
         | value=strings { _PyAST_MatchValue(value, EXTRA) }
         | 'None' { _PyAST_MatchSingleton(Py_None, EXTRA) }
         | 'True' { _PyAST_MatchSingleton(Py_True, EXTRA) }
         | 'False' { _PyAST_MatchSingleton(Py_False, EXTRA) }

     # Literal expressions are used to restrict permitted mapping pattern keys
     literal_expr[expr_ty]:
         | signed_number !('+' | '-')
         | complex_number
         | &(STRING|FSTRING_START|TSTRING_START) strings
         | 'None' { _PyAST_Constant(Py_None, NULL, EXTRA) }
         | 'True' { _PyAST_Constant(Py_True, NULL, EXTRA) }
         | 'False' { _PyAST_Constant(Py_False, NULL, EXTRA) }

     complex_number[expr_ty]:
         | real=signed_real_number '+' imag=imaginary_number {
             _PyAST_BinOp(real, Add, imag, EXTRA) }
         | real=signed_real_number '-' imag=imaginary_number  {
             _PyAST_BinOp(real, Sub, imag, EXTRA) }

     signed_number[expr_ty]:
         | NUMBER
         | '-' number=NUMBER { _PyAST_UnaryOp(USub, number, EXTRA) }

     signed_real_number[expr_ty]:
         | real_number
         | '-' real=real_number { _PyAST_UnaryOp(USub, real, EXTRA) }

     real_number[expr_ty]:
         | real=NUMBER { _PyPegen_ensure_real(p, real) }

     imaginary_number[expr_ty]:
         | imag=NUMBER { _PyPegen_ensure_imaginary(p, imag) }

     capture_pattern[pattern_ty]:
         | target=pattern_capture_target { _PyAST_MatchAs(NULL, target->v.Name.id, EXTRA) }

     pattern_capture_target[expr_ty]:
         | !"_" name=NAME !('.' | '(' | '=') {
             _PyPegen_set_expr_context(p, name, Store) }

     wildcard_pattern[pattern_ty]:
         | "_" { _PyAST_MatchAs(NULL, NULL, EXTRA) }

     value_pattern[pattern_ty]:
         | attr=attr !('.' | '(' | '=') { _PyAST_MatchValue(attr, EXTRA) }

     attr[expr_ty]:
         | value=name_or_attr '.' attr=NAME {
             _PyAST_Attribute(value, attr->v.Name.id, Load, EXTRA) }

     name_or_attr[expr_ty]:
         | attr
         | NAME

     group_pattern[pattern_ty]:
         | '(' pattern=pattern ')' { pattern }

     sequence_pattern[pattern_ty]:
         | '[' patterns=maybe_sequence_pattern? ']' { _PyAST_MatchSequence(patterns, EXTRA) }
         | '(' patterns=open_sequence_pattern? ')' { _PyAST_MatchSequence(patterns, EXTRA) }

     open_sequence_pattern[asdl_seq*]:
         | pattern=maybe_star_pattern ',' patterns=maybe_sequence_pattern? {
             _PyPegen_seq_insert_in_front(p, pattern, patterns) }

     maybe_sequence_pattern[asdl_seq*]:
         | patterns=','.maybe_star_pattern+ ','? { patterns }

     maybe_star_pattern[pattern_ty]:
         | star_pattern
         | pattern

     star_pattern[pattern_ty] (memo):
         | '*' target=pattern_capture_target {
             _PyAST_MatchStar(target->v.Name.id, EXTRA) }
         | '*' wildcard_pattern {
             _PyAST_MatchStar(NULL, EXTRA) }

     mapping_pattern[pattern_ty]:
         | '{' '}' {
             _PyAST_MatchMapping(NULL, NULL, NULL, EXTRA) }
         | '{' rest=double_star_pattern ','? '}' {
             _PyAST_MatchMapping(NULL, NULL, rest->v.Name.id, EXTRA) }
         | '{' items=items_pattern ',' rest=double_star_pattern ','? '}' {
             _PyAST_MatchMapping(
                 CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, items)),
                 CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, items)),
                 rest->v.Name.id,
                 EXTRA) }
         | '{' items=items_pattern ','? '}' {
             _PyAST_MatchMapping(
                 CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, items)),
                 CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, items)),
                 NULL,
                 EXTRA) }

     items_pattern[asdl_seq*]:
         | ','.key_value_pattern+

     key_value_pattern[KeyPatternPair*]:
         | key=(literal_expr | attr) ':' pattern=pattern {
             _PyPegen_key_pattern_pair(p, key, pattern) }

     double_star_pattern[expr_ty]:
         | '**' target=pattern_capture_target { target }

     class_pattern[pattern_ty]:
         | cls=name_or_attr '(' ')' {
             _PyAST_MatchClass(cls, NULL, NULL, NULL, EXTRA) }
         | cls=name_or_attr '(' patterns=positional_patterns ','? ')' {
             _PyAST_MatchClass(cls, patterns, NULL, NULL, EXTRA) }
         | cls=name_or_attr '(' keywords=keyword_patterns ','? ')' {
             _PyAST_MatchClass(
                 cls, NULL,
                 CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p,
                     CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, keywords)))),
                 CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, keywords)),
                 EXTRA) }
         | cls=name_or_attr '(' patterns=positional_patterns ',' keywords=keyword_patterns ','? ')' {
             _PyAST_MatchClass(
                 cls,
                 patterns,
                 CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p,
                     CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, keywords)))),
                 CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, keywords)),
                 EXTRA) }
         | invalid_class_pattern

     positional_patterns[asdl_pattern_seq*]:
         | args[asdl_pattern_seq*]=','.pattern+ { args }

     keyword_patterns[asdl_seq*]:
         | ','.keyword_pattern+

     keyword_pattern[KeyPatternPair*]:
         | arg=NAME '=' value=pattern { _PyPegen_key_pattern_pair(p, arg, value) }

     # Type statement
     # ---------------

     type_alias[stmt_ty]:
         | "type" n=NAME t=[type_params] '=' b=expression {
             CHECK_VERSION(stmt_ty, 12, "Type statement is",
             _PyAST_TypeAlias(CHECK(expr_ty, _PyPegen_set_expr_context(p, n, Store)), t, b, EXTRA)) }

     # Type parameter declaration
     # --------------------------

     type_params[asdl_type_param_seq*]:
         | invalid_type_params
         | '[' t=type_param_seq ']' {
             CHECK_VERSION(asdl_type_param_seq *, 12, "Type parameter lists are", t) }

     type_param_seq[asdl_type_param_seq*]: a[asdl_type_param_seq*]=','.type_param+ [','] { a }

     type_param[type_param_ty] (memo):
         | a=NAME b=[type_param_bound] c=[type_param_default] { _PyAST_TypeVar(a->v.Name.id, b, c, EXTRA) }
         | invalid_type_param
         | '*' a=NAME b=[type_param_starred_default] { _PyAST_TypeVarTuple(a->v.Name.id, b, EXTRA) }
         | '**' a=NAME b=[type_param_default] { _PyAST_ParamSpec(a->v.Name.id, b, EXTRA) }

     type_param_bound[expr_ty]: ':' e=expression { e }
     type_param_default[expr_ty]: '=' e=expression {
         CHECK_VERSION(expr_ty, 13, "Type parameter defaults are", e) }
     type_param_starred_default[expr_ty]: '=' e=star_expression {
         CHECK_VERSION(expr_ty, 13, "Type parameter defaults are", e) }

     # EXPRESSIONS
     # -----------

     expressions[expr_ty]:
         | a=expression b=(',' c=expression { c })+ [','] {
             _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)), Load, EXTRA) }
         | a=expression ',' { _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_singleton_seq(p, a)), Load, EXTRA) }
         | expression

     expression[expr_ty] (memo):
         | invalid_expression
         | invalid_legacy_expression
         | a=disjunction 'if' b=disjunction 'else' c=expression { _PyAST_IfExp(b, a, c, EXTRA) }
         | disjunction
         | lambdef

     yield_expr[expr_ty]:
         | 'yield' 'from' a=expression { _PyAST_YieldFrom(a, EXTRA) }
         | 'yield' a=[star_expressions] { _PyAST_Yield(a, EXTRA) }

     star_expressions[expr_ty]:
         | a=star_expression b=(',' c=star_expression { c })+ [','] {
             _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)), Load, EXTRA) }
         | a=star_expression ',' { _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_singleton_seq(p, a)), Load, EXTRA) }
         | star_expression

     star_expression[expr_ty] (memo):
         | '*' a=bitwise_or { _PyAST_Starred(a, Load, EXTRA) }
         | expression

     star_named_expressions[asdl_expr_seq*]: a[asdl_expr_seq*]=','.star_named_expression+ [','] { a }

     star_named_expression[expr_ty]:
         | '*' a=bitwise_or { _PyAST_Starred(a, Load, EXTRA) }
         | named_expression

     assignment_expression[expr_ty]:
         | a=NAME ':=' ~ b=expression {
             CHECK_VERSION(expr_ty, 8, "Assignment expressions are",
             _PyAST_NamedExpr(CHECK(expr_ty, _PyPegen_set_expr_context(p, a, Store)), b, EXTRA)) }

     named_expression[expr_ty]:
         | assignment_expression
         | invalid_named_expression
         | expression !':='

     disjunction[expr_ty] (memo):
         | a=conjunction b=('or' c=conjunction { c })+ { _PyAST_BoolOp(
             Or,
             CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)),
             EXTRA) }
         | conjunction

     conjunction[expr_ty] (memo):
         | a=inversion b=('and' c=inversion { c })+ { _PyAST_BoolOp(
             And,
             CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)),
             EXTRA) }
         | inversion

     inversion[expr_ty] (memo):
         | 'not' a=inversion { _PyAST_UnaryOp(Not, a, EXTRA) }
         | comparison

     # Comparison operators
     # --------------------

     comparison[expr_ty]:
         | a=bitwise_or b=compare_op_bitwise_or_pair+ {
             _PyAST_Compare(
                 a,
                 CHECK(asdl_int_seq*, _PyPegen_get_cmpops(p, b)),
                 CHECK(asdl_expr_seq*, _PyPegen_get_exprs(p, b)),
                 EXTRA) }
         | bitwise_or

     compare_op_bitwise_or_pair[CmpopExprPair*]:
         | eq_bitwise_or
         | noteq_bitwise_or
         | lte_bitwise_or
         | lt_bitwise_or
         | gte_bitwise_or
         | gt_bitwise_or
         | notin_bitwise_or
         | in_bitwise_or
         | isnot_bitwise_or
         | is_bitwise_or

     eq_bitwise_or[CmpopExprPair*]: '==' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Eq, a) }
     noteq_bitwise_or[CmpopExprPair*]:
         | (tok='!=' { _PyPegen_check_barry_as_flufl(p, tok) ? NULL : tok}) a=bitwise_or {_PyPegen_cmpop_expr_pair(p, NotEq, a) }
     lte_bitwise_or[CmpopExprPair*]: '<=' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, LtE, a) }
     lt_bitwise_or[CmpopExprPair*]: '<' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Lt, a) }
     gte_bitwise_or[CmpopExprPair*]: '>=' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, GtE, a) }
     gt_bitwise_or[CmpopExprPair*]: '>' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Gt, a) }
     notin_bitwise_or[CmpopExprPair*]: 'not' 'in' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, NotIn, a) }
     in_bitwise_or[CmpopExprPair*]: 'in' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, In, a) }
     isnot_bitwise_or[CmpopExprPair*]: 'is' 'not' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, IsNot, a) }
     is_bitwise_or[CmpopExprPair*]: 'is' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Is, a) }

     # Bitwise operators
     # -----------------

     bitwise_or[expr_ty]:
         | a=bitwise_or '|' b=bitwise_xor { _PyAST_BinOp(a, BitOr, b, EXTRA) }
         | bitwise_xor

     bitwise_xor[expr_ty]:
         | a=bitwise_xor '^' b=bitwise_and { _PyAST_BinOp(a, BitXor, b, EXTRA) }
         | bitwise_and

     bitwise_and[expr_ty]:
         | a=bitwise_and '&' b=shift_expr { _PyAST_BinOp(a, BitAnd, b, EXTRA) }
         | shift_expr

     shift_expr[expr_ty]:
         | a=shift_expr '<<' b=sum { _PyAST_BinOp(a, LShift, b, EXTRA) }
         | a=shift_expr '>>' b=sum { _PyAST_BinOp(a, RShift, b, EXTRA) }
         | invalid_arithmetic
         | sum

     # Arithmetic operators
     # --------------------

     sum[expr_ty]:
         | a=sum '+' b=term { _PyAST_BinOp(a, Add, b, EXTRA) }
         | a=sum '-' b=term { _PyAST_BinOp(a, Sub, b, EXTRA) }
         | term

     term[expr_ty]:
         | a=term '*' b=factor { _PyAST_BinOp(a, Mult, b, EXTRA) }
         | a=term '/' b=factor { _PyAST_BinOp(a, Div, b, EXTRA) }
         | a=term '//' b=factor { _PyAST_BinOp(a, FloorDiv, b, EXTRA) }
         | a=term '%' b=factor { _PyAST_BinOp(a, Mod, b, EXTRA) }
         | a=term '@' b=factor { CHECK_VERSION(expr_ty, 5, "The '@' operator is", _PyAST_BinOp(a, MatMult, b, EXTRA)) }
         | invalid_factor
         | factor

     factor[expr_ty] (memo):
         | '+' a=factor { _PyAST_UnaryOp(UAdd, a, EXTRA) }
         | '-' a=factor { _PyAST_UnaryOp(USub, a, EXTRA) }
         | '~' a=factor { _PyAST_UnaryOp(Invert, a, EXTRA) }
         | power

     power[expr_ty]:
         | a=await_primary '**' b=factor { _PyAST_BinOp(a, Pow, b, EXTRA) }
         | await_primary

     # Primary elements
     # ----------------

     # Primary elements are things like "obj.something.something", "obj[something]", "obj(something)", "obj" ...

     await_primary[expr_ty] (memo):
         | 'await' a=primary { CHECK_VERSION(expr_ty, 5, "Await expressions are", _PyAST_Await(a, EXTRA)) }
         | primary

     primary[expr_ty]:
         | a=primary '.' b=NAME { _PyAST_Attribute(a, b->v.Name.id, Load, EXTRA) }
         | a=primary b=genexp { _PyAST_Call(a, CHECK(asdl_expr_seq*, (asdl_expr_seq*)_PyPegen_singleton_seq(p, b)), NULL, EXTRA) }
         | a=primary '(' b=[arguments] ')' {
             _PyAST_Call(a,
                      (b) ? ((expr_ty) b)->v.Call.args : NULL,
                      (b) ? ((expr_ty) b)->v.Call.keywords : NULL,
                      EXTRA) }
         | a=primary '[' b=slices ']' { _PyAST_Subscript(a, b, Load, EXTRA) }
         | atom

     slices[expr_ty]:
         | a=slice !',' { a }
         | a[asdl_expr_seq*]=','.(slice | starred_expression)+ [','] { _PyAST_Tuple(a, Load, EXTRA) }

     slice[expr_ty]:
         | a=[expression] ':' b=[expression] c=[':' d=[expression] { d }] { _PyAST_Slice(a, b, c, EXTRA) }
         | a=named_expression { a }

     atom[expr_ty]:
         | NAME
         | 'True' { _PyAST_Constant(Py_True, NULL, EXTRA) }
         | 'False' { _PyAST_Constant(Py_False, NULL, EXTRA) }
         | 'None' { _PyAST_Constant(Py_None, NULL, EXTRA) }
         | &(STRING|FSTRING_START|TSTRING_START) strings
         | NUMBER
         | &'(' (tuple | group | genexp)
         | &'[' (list | listcomp)
         | &'{' (dict | set | dictcomp | setcomp)
         | '...' { _PyAST_Constant(Py_Ellipsis, NULL, EXTRA) }

     group[expr_ty]:
         | '(' a=(yield_expr | named_expression) ')' { a }
         | invalid_group

     # Lambda functions
     # ----------------

     lambdef[expr_ty]:
         | 'lambda' a=[lambda_params] ':' b=expression {
             _PyAST_Lambda((a) ? a : CHECK(arguments_ty, _PyPegen_empty_arguments(p)), b, EXTRA) }

     lambda_params[arguments_ty]:
         | invalid_lambda_parameters
         | lambda_parameters

     # lambda_parameters etc. duplicates parameters but without annotations
     # or type comments, and if there's no comma after a parameter, we expect
     # a colon, not a close parenthesis.  (For more, see parameters above.)
     #
     lambda_parameters[arguments_ty]:
         | a=lambda_slash_no_default b[asdl_arg_seq*]=lambda_param_no_default* c=lambda_param_with_default* d=[lambda_star_etc] {
             CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, a, NULL, b, c, d)) }
         | a=lambda_slash_with_default b=lambda_param_with_default* c=[lambda_star_etc] {
             CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, NULL, a, NULL, b, c)) }
         | a[asdl_arg_seq*]=lambda_param_no_default+ b=lambda_param_with_default* c=[lambda_star_etc] {
             _PyPegen_make_arguments(p, NULL, NULL, a, b, c) }
         | a=lambda_param_with_default+ b=[lambda_star_etc] { _PyPegen_make_arguments(p, NULL, NULL, NULL, a, b)}
         | a=lambda_star_etc { _PyPegen_make_arguments(p, NULL, NULL, NULL, NULL, a) }

     lambda_slash_no_default[asdl_arg_seq*]:
         | a[asdl_arg_seq*]=lambda_param_no_default+ '/' ',' { a }
         | a[asdl_arg_seq*]=lambda_param_no_default+ '/' &':' { a }

     lambda_slash_with_default[SlashWithDefault*]:
         | a=lambda_param_no_default* b=lambda_param_with_default+ '/' ',' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }
         | a=lambda_param_no_default* b=lambda_param_with_default+ '/' &':' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }

     lambda_star_etc[StarEtc*]:
         | invalid_lambda_star_etc
         | '*' a=lambda_param_no_default b=lambda_param_maybe_default* c=[lambda_kwds] {
             _PyPegen_star_etc(p, a, b, c) }
         | '*' ',' b=lambda_param_maybe_default+ c=[lambda_kwds] {
             _PyPegen_star_etc(p, NULL, b, c) }
         | a=lambda_kwds { _PyPegen_star_etc(p, NULL, NULL, a) }

     lambda_kwds[arg_ty]:
         | invalid_lambda_kwds
         | '**' a=lambda_param_no_default { a }

     lambda_param_no_default[arg_ty]:
         | a=lambda_param ',' { a }
         | a=lambda_param &':' { a }
     lambda_param_with_default[NameDefaultPair*]:
         | a=lambda_param c=default ',' { _PyPegen_name_default_pair(p, a, c, NULL) }
         | a=lambda_param c=default &':' { _PyPegen_name_default_pair(p, a, c, NULL) }
     lambda_param_maybe_default[NameDefaultPair*]:
         | a=lambda_param c=default? ',' { _PyPegen_name_default_pair(p, a, c, NULL) }
         | a=lambda_param c=default? &':' { _PyPegen_name_default_pair(p, a, c, NULL) }
     lambda_param[arg_ty]: a=NAME { _PyAST_arg(a->v.Name.id, NULL, NULL, EXTRA) }

     # LITERALS
     # ========

     fstring_middle[expr_ty]:
         | fstring_replacement_field
         | t=FSTRING_MIDDLE { _PyPegen_constant_from_token(p, t) }
     fstring_replacement_field[expr_ty]:
         | '{' a=annotated_rhs debug_expr='='? conversion=[fstring_conversion] format=[fstring_full_format_spec] rbrace='}' {
             _PyPegen_formatted_value(p, a, debug_expr, conversion, format, rbrace, EXTRA) }
         | invalid_fstring_replacement_field
     fstring_conversion[ResultTokenWithMetadata*]:
         | conv_token="!" conv=NAME { _PyPegen_check_fstring_conversion(p, conv_token, conv) }
     fstring_full_format_spec[ResultTokenWithMetadata*]:
         | colon=':' spec=fstring_format_spec* { _PyPegen_setup_full_format_spec(p, colon, (asdl_expr_seq *) spec, EXTRA) }
     fstring_format_spec[expr_ty]:
         | t=FSTRING_MIDDLE { _PyPegen_decoded_constant_from_token(p, t) }
         | fstring_replacement_field
     fstring[expr_ty]:
         | a=FSTRING_START b=fstring_middle* c=FSTRING_END { _PyPegen_joined_str(p, a, (asdl_expr_seq*)b, c) }

     tstring_format_spec_replacement_field[expr_ty]:
         | '{' a=annotated_rhs debug_expr='='? conversion=[fstring_conversion] format=[tstring_full_format_spec] rbrace='}' {
             _PyPegen_formatted_value(p, a, debug_expr, conversion, format, rbrace, EXTRA) }
         | invalid_tstring_replacement_field
     tstring_format_spec[expr_ty]:
         | t=TSTRING_MIDDLE { _PyPegen_decoded_constant_from_token(p, t) }
         | tstring_format_spec_replacement_field
     tstring_full_format_spec[ResultTokenWithMetadata*]:
         | colon=':' spec=tstring_format_spec* { _PyPegen_setup_full_format_spec(p, colon, (asdl_expr_seq *) spec, EXTRA) }
     tstring_replacement_field[expr_ty]:
         | '{' a=annotated_rhs debug_expr='='? conversion=[fstring_conversion] format=[tstring_full_format_spec] rbrace='}' {
             _PyPegen_interpolation(p, a, debug_expr, conversion, format, rbrace, EXTRA) }
         | invalid_tstring_replacement_field
     tstring_middle[expr_ty]:
         | tstring_replacement_field
         | t=TSTRING_MIDDLE { _PyPegen_constant_from_token(p, t) }
     tstring[expr_ty] (memo):
         | a=TSTRING_START b=tstring_middle* c=TSTRING_END {
             CHECK_VERSION(
                 expr_ty,
                 14,
                 "t-strings are",
                 _PyPegen_template_str(p, a, (asdl_expr_seq*)b, c)) }

     string[expr_ty]: s[Token*]=STRING { _PyPegen_constant_from_string(p, s) }
     strings[expr_ty] (memo):
         | invalid_string_tstring_concat
         | a[asdl_expr_seq*]=(fstring|string)+ { _PyPegen_concatenate_strings(p, a, EXTRA) }
         | a[asdl_expr_seq*]=tstring+ { _PyPegen_concatenate_tstrings(p, a, EXTRA) }

     list[expr_ty]:
         | '[' a=[star_named_expressions] ']' { _PyAST_List(a, Load, EXTRA) }

     tuple[expr_ty]:
         | '(' a=[y=star_named_expression ',' z=[star_named_expressions] { _PyPegen_seq_insert_in_front(p, y, z) } ] ')' {
             _PyAST_Tuple(a, Load, EXTRA) }

     set[expr_ty]: '{' a=star_named_expressions '}' { _PyAST_Set(a, EXTRA) }

     # Dicts
     # -----

     dict[expr_ty]:
         | '{' a=[double_starred_kvpairs] '}' {
             _PyAST_Dict(
                 CHECK(asdl_expr_seq*, _PyPegen_get_keys(p, a)),
                 CHECK(asdl_expr_seq*, _PyPegen_get_values(p, a)),
                 EXTRA) }
         | '{' invalid_double_starred_kvpairs '}'

     double_starred_kvpairs[asdl_seq*]: a=','.double_starred_kvpair+ [','] { a }

     double_starred_kvpair[KeyValuePair*]:
         | '**' a=bitwise_or { _PyPegen_key_value_pair(p, NULL, a) }
         | kvpair

     kvpair[KeyValuePair*]: a=expression ':' b=expression { _PyPegen_key_value_pair(p, a, b) }

     # Comprehensions & Generators
     # ---------------------------

     for_if_clauses[asdl_comprehension_seq*]:
         | a[asdl_comprehension_seq*]=for_if_clause+ { a }

     for_if_clause[comprehension_ty]:
         | 'async' 'for' a=star_targets 'in' ~ b=disjunction c[asdl_expr_seq*]=('if' z=disjunction { z })* {
             CHECK_VERSION(comprehension_ty, 6, "Async comprehensions are", _PyAST_comprehension(a, b, c, 1, p->arena)) }
         | 'for' a=star_targets 'in' ~ b=disjunction c[asdl_expr_seq*]=('if' z=disjunction { z })* {
             _PyAST_comprehension(a, b, c, 0, p->arena) }
         | invalid_for_if_clause
         | invalid_for_target

     listcomp[expr_ty]:
         | '[' a=named_expression b=for_if_clauses ']' { _PyAST_ListComp(a, b, EXTRA) }
         | invalid_comprehension

     setcomp[expr_ty]:
         | '{' a=named_expression b=for_if_clauses '}' { _PyAST_SetComp(a, b, EXTRA) }
         | invalid_comprehension

     genexp[expr_ty]:
         | '(' a=( assignment_expression | expression !':=') b=for_if_clauses ')' { _PyAST_GeneratorExp(a, b, EXTRA) }
         | invalid_comprehension

     dictcomp[expr_ty]:
         | '{' a=kvpair b=for_if_clauses '}' { _PyAST_DictComp(a->key, a->value, b, EXTRA) }
         | invalid_dict_comprehension

     # FUNCTION CALL ARGUMENTS
     # =======================

     arguments[expr_ty] (memo):
         | a=args [','] &')' { a }
         | invalid_arguments

     args[expr_ty]:
         | a[asdl_expr_seq*]=','.(starred_expression | ( assignment_expression | expression !':=') !'=')+ b=[',' k=kwargs {k}] {
             _PyPegen_collect_call_seqs(p, a, b, EXTRA) }
         | a=kwargs { _PyAST_Call(_PyPegen_dummy_name(p),
                               CHECK_NULL_ALLOWED(asdl_expr_seq*, _PyPegen_seq_extract_starred_exprs(p, a)),
                               CHECK_NULL_ALLOWED(asdl_keyword_seq*, _PyPegen_seq_delete_starred_exprs(p, a)),
                               EXTRA) }

     kwargs[asdl_seq*]:
         | a=','.kwarg_or_starred+ ',' b=','.kwarg_or_double_starred+ { _PyPegen_join_sequences(p, a, b) }
         | ','.kwarg_or_starred+
         | ','.kwarg_or_double_starred+

     starred_expression[expr_ty]:
         | invalid_starred_expression_unpacking
         | '*' a=expression { _PyAST_Starred(a, Load, EXTRA) }
         | invalid_starred_expression

     kwarg_or_starred[KeywordOrStarred*]:
         | invalid_kwarg
         | a=NAME '=' b=expression {
             _PyPegen_keyword_or_starred(p, CHECK(keyword_ty, _PyAST_keyword(a->v.Name.id, b, EXTRA)), 1) }
         | a=starred_expression { _PyPegen_keyword_or_starred(p, a, 0) }

     kwarg_or_double_starred[KeywordOrStarred*]:
         | invalid_kwarg
         | a=NAME '=' b=expression {
             _PyPegen_keyword_or_starred(p, CHECK(keyword_ty, _PyAST_keyword(a->v.Name.id, b, EXTRA)), 1) }
         | '**' a=expression { _PyPegen_keyword_or_starred(p, CHECK(keyword_ty, _PyAST_keyword(NULL, a, EXTRA)), 1) }

     # ASSIGNMENT TARGETS
     # ==================

     # Generic targets
     # ---------------

     # NOTE: star_targets may contain *bitwise_or, targets may not.
     star_targets[expr_ty]:
         | a=star_target !',' { a }
         | a=star_target b=(',' c=star_target { c })* [','] {
             _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)), Store, EXTRA) }

     star_targets_list_seq[asdl_expr_seq*]: a[asdl_expr_seq*]=','.star_target+ [','] { a }

     star_targets_tuple_seq[asdl_expr_seq*]:
         | a=star_target b=(',' c=star_target { c })+ [','] { (asdl_expr_seq*) _PyPegen_seq_insert_in_front(p, a, b) }
         | a=star_target ',' { (asdl_expr_seq*) _PyPegen_singleton_seq(p, a) }

     star_target[expr_ty] (memo):
         | '*' a=(!'*' star_target) {
             _PyAST_Starred(CHECK(expr_ty, _PyPegen_set_expr_context(p, a, Store)), Store, EXTRA) }
         | target_with_star_atom

     target_with_star_atom[expr_ty] (memo):
         | a=t_primary '.' b=NAME !t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Store, EXTRA) }
         | a=t_primary '[' b=slices ']' !t_lookahead { _PyAST_Subscript(a, b, Store, EXTRA) }
         | star_atom

     star_atom[expr_ty]:
         | a=NAME { _PyPegen_set_expr_context(p, a, Store) }
         | '(' a=target_with_star_atom ')' { _PyPegen_set_expr_context(p, a, Store) }
         | '(' a=[star_targets_tuple_seq] ')' { _PyAST_Tuple(a, Store, EXTRA) }
         | '[' a=[star_targets_list_seq] ']' { _PyAST_List(a, Store, EXTRA) }

     single_target[expr_ty]:
         | single_subscript_attribute_target
         | a=NAME { _PyPegen_set_expr_context(p, a, Store) }
         | '(' a=single_target ')' { a }

     single_subscript_attribute_target[expr_ty]:
         | a=t_primary '.' b=NAME !t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Store, EXTRA) }
         | a=t_primary '[' b=slices ']' !t_lookahead { _PyAST_Subscript(a, b, Store, EXTRA) }

     t_primary[expr_ty]:
         | a=t_primary '.' b=NAME &t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Load, EXTRA) }
         | a=t_primary '[' b=slices ']' &t_lookahead { _PyAST_Subscript(a, b, Load, EXTRA) }
         | a=t_primary b=genexp &t_lookahead {
             _PyAST_Call(a, CHECK(asdl_expr_seq*, (asdl_expr_seq*)_PyPegen_singleton_seq(p, b)), NULL, EXTRA) }
         | a=t_primary '(' b=[arguments] ')' &t_lookahead {
             _PyAST_Call(a,
                      (b) ? ((expr_ty) b)->v.Call.args : NULL,
                      (b) ? ((expr_ty) b)->v.Call.keywords : NULL,
                      EXTRA) }
         | a=atom &t_lookahead { a }

     t_lookahead: '(' | '[' | '.'

     # Targets for del statements
     # --------------------------

     del_targets[asdl_expr_seq*]: a[asdl_expr_seq*]=','.del_target+ [','] { a }

     del_target[expr_ty] (memo):
         | a=t_primary '.' b=NAME !t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Del, EXTRA) }
         | a=t_primary '[' b=slices ']' !t_lookahead { _PyAST_Subscript(a, b, Del, EXTRA) }
         | del_t_atom

     del_t_atom[expr_ty]:
         | a=NAME { _PyPegen_set_expr_context(p, a, Del) }
         | '(' a=del_target ')' { _PyPegen_set_expr_context(p, a, Del) }
         | '(' a=[del_targets] ')' { _PyAST_Tuple(a, Del, EXTRA) }
         | '[' a=[del_targets] ']' { _PyAST_List(a, Del, EXTRA) }

     # TYPING ELEMENTS
     # ---------------

     # type_expressions allow */** but ignore them
     type_expressions[asdl_expr_seq*]:
         | a=','.expression+ ',' '*' b=expression ',' '**' c=expression {
             (asdl_expr_seq*)_PyPegen_seq_append_to_end(
                 p,
                 CHECK(asdl_seq*, _PyPegen_seq_append_to_end(p, a, b)),
                 c) }
         | a=','.expression+ ',' '*' b=expression { (asdl_expr_seq*)_PyPegen_seq_append_to_end(p, a, b) }
         | a=','.expression+ ',' '**' b=expression { (asdl_expr_seq*)_PyPegen_seq_append_to_end(p, a, b) }
         | '*' a=expression ',' '**' b=expression {
             (asdl_expr_seq*)_PyPegen_seq_append_to_end(
                 p,
                 CHECK(asdl_seq*, _PyPegen_singleton_seq(p, a)),
                 b) }
         | '*' a=expression { (asdl_expr_seq*)_PyPegen_singleton_seq(p, a) }
         | '**' a=expression { (asdl_expr_seq*)_PyPegen_singleton_seq(p, a) }
         | a[asdl_expr_seq*]=','.expression+ {a}

     func_type_comment[Token*]:
         | NEWLINE t=TYPE_COMMENT &(NEWLINE INDENT) { t }  # Must be followed by indented block
         | invalid_double_type_comments
         | TYPE_COMMENT

     # ========================= END OF THE GRAMMAR ===========================



     # ========================= START OF INVALID RULES =======================

     # From here on, there are rules for invalid syntax with specialised error messages
     invalid_arguments:
         | ((','.(starred_expression | ( assignment_expression | expression !':=') !'=')+ ',' kwargs) | kwargs) a=',' ','.(starred_expression !'=')+ {
             RAISE_SYNTAX_ERROR_STARTING_FROM(a, "iterable argument unpacking follows keyword argument unpacking") }
         | a=expression b=for_if_clauses ',' [args | expression for_if_clauses] {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, _PyPegen_get_last_comprehension_item(PyPegen_last_item(b, comprehension_ty)), "Generator expression must be parenthesized") }
         | a=NAME b='=' expression for_if_clauses {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Maybe you meant '==' or ':=' instead of '='?")}
         | (args ',')? a=NAME b='=' &(',' | ')') {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "expected argument value expression")}
         | a=args b=for_if_clauses { _PyPegen_nonparen_genexp_in_call(p, a, b) }
         | args ',' a=expression b=for_if_clauses {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, _PyPegen_get_last_comprehension_item(PyPegen_last_item(b, comprehension_ty)), "Generator expression must be parenthesized") }
         | a=args ',' args { _PyPegen_arguments_parsing_error(p, a) }
     invalid_kwarg:
         | a[Token*]=('True'|'False'|'None') b='=' {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to %s", PyBytes_AS_STRING(a->bytes)) }
         | a=NAME b='=' expression for_if_clauses {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Maybe you meant '==' or ':=' instead of '='?")}
         | !(NAME '=') a=expression b='=' {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(
                 a, b, "expression cannot contain assignment, perhaps you meant \"==\"?") }
         | a='**' expression '=' b=expression {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to keyword argument unpacking") }

     # IMPORTANT: Note that the "_without_invalid" suffix causes the rule to not call invalid rules under it
     expression_without_invalid[expr_ty]:
         | a=disjunction 'if' b=disjunction 'else' c=expression { _PyAST_IfExp(b, a, c, EXTRA) }
         | disjunction
         | lambdef
     invalid_legacy_expression:
         | a=NAME !'(' b=star_expressions {
             _PyPegen_check_legacy_stmt(p, a) ? RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b,
                 "Missing parentheses in call to '%U'. Did you mean %U(...)?", a->v.Name.id, a->v.Name.id) : NULL}

     invalid_type_param:
         | '*' a=NAME colon=':' e=expression {
                 RAISE_SYNTAX_ERROR_STARTING_FROM(colon, e->kind == Tuple_kind
                     ? "cannot use constraints with TypeVarTuple"
                     : "cannot use bound with TypeVarTuple")
             }
         | '**' a=NAME colon=':' e=expression {
                 RAISE_SYNTAX_ERROR_STARTING_FROM(colon, e->kind == Tuple_kind
                     ? "cannot use constraints with ParamSpec"
                     : "cannot use bound with ParamSpec")
             }

     invalid_expression:
        |  STRING a=(!STRING expression_without_invalid)+ STRING {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE( PyPegen_first_item(a, expr_ty), PyPegen_last_item(a, expr_ty),
             "invalid syntax. Is this intended to be part of the string?") }
         # !(NAME STRING) is not matched so we don't show this error with some invalid string prefixes like: kf"dsfsdf"
         # Soft keywords need to also be ignored because they can be parsed as NAME NAME
        | !(NAME STRING | SOFT_KEYWORD) a=disjunction b=expression_without_invalid {
             _PyPegen_check_legacy_stmt(p, a) ? NULL : p->tokens[p->mark-1]->level == 0 ? NULL :
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Perhaps you forgot a comma?") }
        | a=disjunction 'if' b=disjunction !('else'|':') { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "expected 'else' after 'if' expression") }
        | a=disjunction 'if' b=disjunction 'else' !expression {
             RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("expected expression after 'else', but statement is given") }
        | a[stmt_ty]=(pass_stmt|break_stmt|continue_stmt) 'if' b=disjunction 'else' c=simple_stmt {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION (a, "expected expression before 'if', but statement is given") }
        | a='lambda' [lambda_params] b=':' &FSTRING_MIDDLE  {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "f-string: lambda expressions are not allowed without parentheses") }
        | a='lambda' [lambda_params] b=':' &TSTRING_MIDDLE  {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "t-string: lambda expressions are not allowed without parentheses") }

     invalid_named_expression(memo):
         | a=expression ':=' expression {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
                 a, "cannot use assignment expressions with %s", _PyPegen_get_expr_name(a)) }
         | a=NAME '=' b=bitwise_or !('='|':=') {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Maybe you meant '==' or ':=' instead of '='?") }
         | !(list|tuple|genexp|'True'|'None'|'False') a=bitwise_or b='=' bitwise_or !('='|':=') {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot assign to %s here. Maybe you meant '==' instead of '='?",
                                               _PyPegen_get_expr_name(a)) }

     invalid_assignment:
         | a=invalid_ann_assign_target ':' expression {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
                 a,
                 "only single target (not %s) can be annotated",
                 _PyPegen_get_expr_name(a)
             )}
         | a=star_named_expression ',' star_named_expressions* ':' expression {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "only single target (not tuple) can be annotated") }
         | a=expression ':' expression {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "illegal target for annotation") }
         | (star_targets '=')* a=star_expressions '=' {
             RAISE_SYNTAX_ERROR_INVALID_TARGET(STAR_TARGETS, a) }
         | (star_targets '=')* a=yield_expr '=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "assignment to yield expression not possible") }
         | a=star_expressions augassign annotated_rhs {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
                 a,
                 "'%s' is an illegal expression for augmented assignment",
                 _PyPegen_get_expr_name(a)
             )}
     invalid_ann_assign_target[expr_ty]:
         | list
         | tuple
         | '(' a=invalid_ann_assign_target ')' { a }
     invalid_del_stmt:
         | 'del' a=star_expressions {
             RAISE_SYNTAX_ERROR_INVALID_TARGET(DEL_TARGETS, a) }
     invalid_block:
         | NEWLINE !INDENT { RAISE_INDENTATION_ERROR("expected an indented block") }
     invalid_comprehension:
         | ('[' | '(' | '{') a=starred_expression for_if_clauses {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "iterable unpacking cannot be used in comprehension") }
         | ('[' | '{') a=star_named_expression ',' b=star_named_expressions for_if_clauses {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, PyPegen_last_item(b, expr_ty),
             "did you forget parentheses around the comprehension target?") }
         | ('[' | '{') a=star_named_expression b=',' for_if_clauses {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "did you forget parentheses around the comprehension target?") }
     invalid_dict_comprehension:
         | '{' a='**' bitwise_or for_if_clauses '}' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "dict unpacking cannot be used in dict comprehension") }
     invalid_parameters:
         | a="/" ',' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "at least one argument must precede /") }
         | (slash_no_default | slash_with_default) param_maybe_default* a='/' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ may appear only once") }
         | slash_no_default? param_no_default* invalid_parameters_helper a=param_no_default {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "parameter without a default follows parameter with a default") }
         | param_no_default* a='(' param_no_default+ ','? b=')' {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "Function parameters cannot be parenthesized") }
         | (slash_no_default | slash_with_default)? param_maybe_default* '*' (',' | param_no_default) param_maybe_default* a='/' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ must be ahead of *") }
         | param_maybe_default+ '/' a='*' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expected comma between / and *") }
     invalid_default:
         | a='=' &(')'|',') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expected default value expression") }
     invalid_star_etc:
         | a='*' (')' | ',' (')' | '**')) { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "named arguments must follow bare *") }
         | '*' ',' TYPE_COMMENT { RAISE_SYNTAX_ERROR("bare * has associated type comment") }
         | '*' param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-positional argument cannot have default value") }
         | '*' (param_no_default | ',') param_maybe_default* a='*' (param_no_default | ',') {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "* argument may appear only once") }
     invalid_kwds:
         | '**' param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-keyword argument cannot have default value") }
         | '**' param ',' a=param { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
         | '**' param ',' a[Token*]=('*'|'**'|'/') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
     invalid_parameters_helper: # This is only there to avoid type errors
         | a=slash_with_default { _PyPegen_singleton_seq(p, a) }
         | param_with_default+
     invalid_lambda_parameters:
         | a="/" ',' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "at least one argument must precede /") }
         | (lambda_slash_no_default | lambda_slash_with_default) lambda_param_maybe_default* a='/' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ may appear only once") }
         | lambda_slash_no_default? lambda_param_no_default* invalid_lambda_parameters_helper a=lambda_param_no_default {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "parameter without a default follows parameter with a default") }
         | lambda_param_no_default* a='(' ','.lambda_param+ ','? b=')' {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "Lambda expression parameters cannot be parenthesized") }
         | (lambda_slash_no_default | lambda_slash_with_default)? lambda_param_maybe_default* '*' (',' | lambda_param_no_default) lambda_param_maybe_default* a='/' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ must be ahead of *") }
         | lambda_param_maybe_default+ '/' a='*' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expected comma between / and *") }
     invalid_lambda_parameters_helper:
         | a=lambda_slash_with_default { _PyPegen_singleton_seq(p, a) }
         | lambda_param_with_default+
     invalid_lambda_star_etc:
         | '*' (':' | ',' (':' | '**')) { RAISE_SYNTAX_ERROR("named arguments must follow bare *") }
         | '*' lambda_param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-positional argument cannot have default value") }
         | '*' (lambda_param_no_default | ',') lambda_param_maybe_default* a='*' (lambda_param_no_default | ',') {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "* argument may appear only once") }
     invalid_lambda_kwds:
         | '**' lambda_param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-keyword argument cannot have default value") }
         | '**' lambda_param ',' a=lambda_param { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
         | '**' lambda_param ',' a[Token*]=('*'|'**'|'/') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
     invalid_double_type_comments:
         | TYPE_COMMENT NEWLINE TYPE_COMMENT NEWLINE INDENT {
             RAISE_SYNTAX_ERROR("Cannot have two type comments on def") }
     invalid_with_item:
         | expression 'as' a=expression &(',' | ')' | ':') {
             RAISE_SYNTAX_ERROR_INVALID_TARGET(STAR_TARGETS, a) }

     invalid_for_if_clause:
         | 'async'? 'for' (bitwise_or (',' bitwise_or)* [',']) !'in' {
             RAISE_SYNTAX_ERROR("'in' expected after for-loop variables") }

     invalid_for_target:
         | 'async'? 'for' a=star_expressions {
             RAISE_SYNTAX_ERROR_INVALID_TARGET(FOR_TARGETS, a) }

     invalid_group:
         | '(' a=starred_expression ')' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot use starred expression here") }
         | '(' a='**' expression ')' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot use double starred expression here") }
     invalid_import:
         | a='import' ','.dotted_name+ 'from' dotted_name {
             RAISE_SYNTAX_ERROR_STARTING_FROM(a, "Did you mean to use 'from ... import ...' instead?") }
         | 'import' token=NEWLINE {
             RAISE_SYNTAX_ERROR_STARTING_FROM(token, "Expected one or more names after 'import'") }
     invalid_dotted_as_name:
         | dotted_name 'as' !(NAME (',' | ')' | ';' | NEWLINE)) a=expression {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a,
                 "cannot use %s as import target", _PyPegen_get_expr_name(a)) }
     invalid_import_from_as_name:
         | NAME 'as' !(NAME (',' | ')' | ';' | NEWLINE)) a=expression {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a,
                 "cannot use %s as import target", _PyPegen_get_expr_name(a)) }

     invalid_import_from_targets:
         | import_from_as_names ',' NEWLINE {
             RAISE_SYNTAX_ERROR("trailing comma not allowed without surrounding parentheses") }
         | token=NEWLINE {
             RAISE_SYNTAX_ERROR_STARTING_FROM(token, "Expected one or more names after 'import'") }

     invalid_with_stmt:
         | ['async'] 'with' ','.(expression ['as' star_target])+ NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
         | ['async'] 'with' '(' ','.(expressions ['as' star_target])+ ','? ')' NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
     invalid_with_stmt_indent:
         | ['async'] a='with' ','.(expression ['as' star_target])+ ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'with' statement on line %d", a->lineno) }
         | ['async'] a='with' '(' ','.(expressions ['as' star_target])+ ','? ')' ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'with' statement on line %d", a->lineno) }

     invalid_try_stmt:
         | a='try' ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'try' statement on line %d", a->lineno) }
         | 'try' ':' block !('except' | 'finally') { RAISE_SYNTAX_ERROR("expected 'except' or 'finally' block") }
         | 'try' ':' block* except_block+ a='except' b='*' expression ['as' NAME] ':' {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot have both 'except' and 'except*' on the same 'try'") }
         | 'try' ':' block* except_star_block+ a='except' [expression ['as' NAME]] ':' {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot have both 'except' and 'except*' on the same 'try'") }
     invalid_except_stmt:
         | 'except' a=expression ',' expressions 'as' NAME  ':' {
             RAISE_SYNTAX_ERROR_STARTING_FROM(a, "multiple exception types must be parenthesized when using 'as'") }
         | a='except' expression ['as' NAME ] NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
         | a='except' NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
         | 'except' expression 'as' a=expression ':' block {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
                 a, "cannot use except statement with %s", _PyPegen_get_expr_name(a)) }
     invalid_except_star_stmt:
         | 'except' '*' a=expression ',' expressions 'as' NAME  ':' {
             RAISE_SYNTAX_ERROR_STARTING_FROM(a, "multiple exception types must be parenthesized when using 'as'") }
         | a='except' '*' expression ['as' NAME ] NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
         | a='except' '*' (NEWLINE | ':') { RAISE_SYNTAX_ERROR("expected one or more exception types") }
         | 'except' '*' expression 'as' a=expression ':' block {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
                 a, "cannot use except* statement with %s", _PyPegen_get_expr_name(a)) }
     invalid_finally_stmt:
         | a='finally' ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'finally' statement on line %d", a->lineno) }
     invalid_except_stmt_indent:
         | a='except' expression ['as' NAME ] ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'except' statement on line %d", a->lineno) }
         | a='except' ':' NEWLINE !INDENT { RAISE_INDENTATION_ERROR("expected an indented block after 'except' statement on line %d", a->lineno) }
     invalid_except_star_stmt_indent:
         | a='except' '*' expression ['as' NAME ] ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'except*' statement on line %d", a->lineno) }
     invalid_match_stmt:
         | "match" subject_expr NEWLINE { CHECK_VERSION(void*, 10, "Pattern matching is", RAISE_SYNTAX_ERROR("expected ':'") ) }
         | a="match" subject=subject_expr ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'match' statement on line %d", a->lineno) }
     invalid_case_block:
         | "case" patterns guard? NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
         | a="case" patterns guard? ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'case' statement on line %d", a->lineno) }
     invalid_as_pattern:
         | or_pattern 'as' a="_" { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot use '_' as a target") }
         | or_pattern 'as' a=expression {
             RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
                 a, "cannot use %s as pattern target", _PyPegen_get_expr_name(a)) }
     invalid_class_pattern:
         | name_or_attr '(' a=invalid_class_argument_pattern  { RAISE_SYNTAX_ERROR_KNOWN_RANGE(
             PyPegen_first_item(a, pattern_ty),
             PyPegen_last_item(a, pattern_ty),
             "positional patterns follow keyword patterns") }
     invalid_class_argument_pattern[asdl_pattern_seq*]:
         | [positional_patterns ','] keyword_patterns ',' a=positional_patterns { a }
     invalid_if_stmt:
         | 'if' named_expression NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
         | a='if' a=named_expression ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'if' statement on line %d", a->lineno) }
     invalid_elif_stmt:
         | 'elif' named_expression NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
         | a='elif' named_expression ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'elif' statement on line %d", a->lineno) }
     invalid_else_stmt:
         | a='else' ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'else' statement on line %d", a->lineno) }
         | 'else' ':' block 'elif' { RAISE_SYNTAX_ERROR("'elif' block follows an 'else' block")}
     invalid_while_stmt:
         | 'while' named_expression NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
         | a='while' named_expression ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'while' statement on line %d", a->lineno) }
     invalid_for_stmt:
         | ['async'] 'for' star_targets 'in' star_expressions NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
         | ['async'] a='for' star_targets 'in' star_expressions ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after 'for' statement on line %d", a->lineno) }
     invalid_def_raw:
         | ['async'] a='def' NAME [type_params] '(' [params] ')' ['->' expression] ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after function definition on line %d", a->lineno) }
         | ['async'] 'def' NAME [type_params] &&'(' [params] ')' ['->' expression] &&':' [func_type_comment] block
     invalid_class_def_raw:
         | 'class' NAME [type_params] ['(' [arguments] ')'] NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
         | a='class' NAME [type_params] ['(' [arguments] ')'] ':' NEWLINE !INDENT {
             RAISE_INDENTATION_ERROR("expected an indented block after class definition on line %d", a->lineno) }

     invalid_double_starred_kvpairs:
         | ','.double_starred_kvpair+ ',' invalid_kvpair
         | expression ':' a='*' bitwise_or { RAISE_SYNTAX_ERROR_STARTING_FROM(a, "cannot use a starred expression in a dictionary value") }
         | expression a=':' &('}'|',') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expression expected after dictionary key and ':'") }
     invalid_kvpair:
         | a=expression !(':') {
             RAISE_ERROR_KNOWN_LOCATION(p, PyExc_SyntaxError, a->lineno, a->end_col_offset - 1, a->end_lineno, -1, "':' expected after dictionary key") }
         | expression ':' a='*' bitwise_or { RAISE_SYNTAX_ERROR_STARTING_FROM(a, "cannot use a starred expression in a dictionary value") }
         | expression a=':' &('}'|',') {RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expression expected after dictionary key and ':'") }
     invalid_starred_expression_unpacking:
         | a='*' expression '=' b=expression { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to iterable argument unpacking") }
     invalid_starred_expression:
         | '*' { RAISE_SYNTAX_ERROR("Invalid star expression") }

     invalid_fstring_replacement_field:
         | '{' a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before '='") }
         | '{' a='!' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before '!'") }
         | '{' a=':' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before ':'") }
         | '{' a='}' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before '}'") }
         | '{' !annotated_rhs { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting a valid expression after '{'") }
         | '{' annotated_rhs !('=' | '!' | ':' | '}') {
             PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '=', or '!', or ':', or '}'") }
         | '{' annotated_rhs '=' !('!' | ':' | '}') {
             PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '!', or ':', or '}'") }
         | '{' annotated_rhs '='? invalid_fstring_conversion_character
         | '{' annotated_rhs '='? ['!' NAME] !(':' | '}') {
             PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting ':' or '}'") }
         | '{' annotated_rhs '='? ['!' NAME] ':' fstring_format_spec* !'}' {
             PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '}', or format specs") }
         | '{' annotated_rhs '='? ['!' NAME] !'}' {
             PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '}'") }

     invalid_fstring_conversion_character:
         | '!' &(':' | '}') { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: missing conversion character") }
         | '!' !NAME { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: invalid conversion character") }

     invalid_tstring_replacement_field:
         | '{' a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "t-string: valid expression required before '='") }
         | '{' a='!' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "t-string: valid expression required before '!'") }
         | '{' a=':' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "t-string: valid expression required before ':'") }
         | '{' a='}' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "t-string: valid expression required before '}'") }
         | '{' !annotated_rhs { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting a valid expression after '{'") }
         | '{' annotated_rhs !('=' | '!' | ':' | '}') {
             PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting '=', or '!', or ':', or '}'") }
         | '{' annotated_rhs '=' !('!' | ':' | '}') {
             PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting '!', or ':', or '}'") }
         | '{' annotated_rhs '='? invalid_tstring_conversion_character
         | '{' annotated_rhs '='? ['!' NAME] !(':' | '}') {
             PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting ':' or '}'") }
         | '{' annotated_rhs '='? ['!' NAME] ':' fstring_format_spec* !'}' {
             PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting '}', or format specs") }
         | '{' annotated_rhs '='? ['!' NAME] !'}' {
             PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting '}'") }

     invalid_tstring_conversion_character:
         | '!' &(':' | '}') { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: missing conversion character") }
         | '!' !NAME { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: invalid conversion character") }

     invalid_string_tstring_concat:
         | a=(fstring|string)+ b[expr_ty]=tstring {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(PyPegen_last_item(a, expr_ty), b, "cannot mix t-string literals with string or bytes literals") }
         | a=tstring+ b[expr_ty]=(fstring|string) {
             RAISE_SYNTAX_ERROR_KNOWN_RANGE(PyPegen_last_item(a, expr_ty), b, "cannot mix t-string literals with string or bytes literals") }

     invalid_arithmetic:
         | sum ('+'|'-'|'*'|'/'|'%'|'//'|'@') a='not' b=inversion { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "'not' after an operator must be parenthesized") }
     invalid_factor:
         | ('+' | '-' | '~') a='not' b=factor { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "'not' after an operator must be parenthesized") }

     invalid_type_params:
         | '[' token=']' {
             RAISE_SYNTAX_ERROR_STARTING_FROM(
                 token,
                 "Type parameter list cannot be empty")}

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Grammar/python.gram


File: python.info,  Node: The Python Standard Library,  Next: Extending and Embedding the Python Interpreter,  Prev: The Python Language Reference,  Up: Top

5 The Python Standard Library
*****************************

While *note The Python Language Reference: 14a. describes the exact
syntax and semantics of the Python language, this library reference
manual describes the standard library that is distributed with Python.
It also describes some of the optional components that are commonly
included in Python distributions.

Python’s standard library is very extensive, offering a wide range of
facilities as indicated by the long table of contents listed below.  The
library contains built-in modules (written in C) that provide access to
system functionality such as file I/O that would otherwise be
inaccessible to Python programmers, as well as modules written in Python
that provide standardized solutions for many problems that occur in
everyday programming.  Some of these modules are explicitly designed to
encourage and enhance the portability of Python programs by abstracting
away platform-specifics into platform-neutral APIs.

The Python installers for the Windows platform usually include the
entire standard library and often also include many additional
components.  For Unix-like operating systems Python is normally provided
as a collection of packages, so it may be necessary to use the packaging
tools provided with the operating system to obtain some or all of the
optional components.

In addition to the standard library, there is an active collection of
hundreds of thousands of components (from individual programs and
modules to packages and entire application development frameworks),
available from the Python Package Index(1).

* Menu:

* Introduction: Introduction<5>.
* Funzioni Incorporate::
* Built-in Constants::
* Tipi incorporati::
* Built-in Exceptions::
* Text Processing Services::
* Binary Data Services::
* Data Types::
* Numeric and Mathematical Modules::
* Functional Programming Modules::
* File and Directory Access::
* Data Persistence::
* Data Compression and Archiving::
* File Formats::
* Cryptographic Services::
* Generic Operating System Services::
* Command-line interface libraries::
* Concurrent Execution::
* Networking and Interprocess Communication::
* Internet Data Handling::
* Structured Markup Processing Tools::
* Internet Protocols and Support::
* Multimedia Services::
* Internationalization::
* Graphical user interfaces with Tk::
* Development Tools::
* Debugging and Profiling::
* Software Packaging and Distribution::
* Python Runtime Services::
* Custom Python Interpreters::
* Importing Modules::
* Python Language Services::
* MS Windows Specific Services::
* Unix-specific services::
* Modules command-line interface (CLI): Modules command-line interface CLI.
* Superseded Modules::
* Removed Modules::
* Security Considerations: Security Considerations<3>.

   ---------- Footnotes ----------

   (1) https://pypi.org


File: python.info,  Node: Introduction<5>,  Next: Funzioni Incorporate,  Up: The Python Standard Library

5.1 Introduction
================

The «Python library» contains several different kinds of components.

It contains data types that would normally be considered part of the
«core» of a language, such as numbers and lists.  For these types, the
Python language core defines the form of literals and places some
constraints on their semantics, but does not fully define the semantics.
(On the other hand, the language core does define syntactic properties
like the spelling and priorities of operators.)

The library also contains built-in functions and exceptions — objects
that can be used by all Python code without the need of an *note import:
7f9. statement.  Some of these are defined by the core language, but
many are not essential for the core semantics and are only described
here.

The bulk of the library, however, consists of a collection of modules.
There are many ways to dissect this collection.  Some modules are
written in C and built in to the Python interpreter; others are written
in Python and imported in source form.  Some modules provide interfaces
that are highly specific to Python, like printing a stack trace; some
provide interfaces that are specific to particular operating systems,
such as access to specific hardware; others provide interfaces that are
specific to a particular application domain, like the World Wide Web.
Some modules are available in all versions and ports of Python; others
are only available when the underlying system supports or requires them;
yet others are available only when a particular configuration option was
chosen at the time when Python was compiled and installed.

This manual is organized «from the inside out:» it first describes the
built-in functions, data types and exceptions, and finally the modules,
grouped in chapters of related modules.

This means that if you start reading this manual from the start, and
skip to the next chapter when you get bored, you will get a reasonable
overview of the available modules and application areas that are
supported by the Python library.  Of course, you don’t 'have' to read it
like a novel — you can also browse the table of contents (in front of
the manual), or look for a specific function, module or term in the
index (in the back).  And finally, if you enjoy learning about random
subjects, you choose a random page number (see module *note random: bd.)
and read a section or two.  Regardless of the order in which you read
the sections of this manual, it helps to start with chapter *note
Funzioni Incorporate: 1464, as the remainder of the manual assumes
familiarity with this material.

Let the show begin!

* Menu:

* Notes on availability::


File: python.info,  Node: Notes on availability,  Up: Introduction<5>

5.1.1 Notes on availability
---------------------------

   * An «Availability: Unix» note means that this function is commonly
     found on Unix systems.  It does not make any claims about its
     existence on a specific operating system.

   * If not separately noted, all functions that claim «Availability:
     Unix» are supported on macOS, iOS and Android, all of which build
     on a Unix core.

   * If an availability note contains both a minimum Kernel version and
     a minimum libc version, then both conditions must hold.  For
     example a feature with note 'Availability: Linux >= 3.17 with glibc
     >= 2.27' requires both Linux 3.17 or newer and glibc 2.27 or newer.

* Menu:

* WebAssembly platforms::
* Mobile platforms::


File: python.info,  Node: WebAssembly platforms,  Next: Mobile platforms,  Up: Notes on availability

5.1.1.1 WebAssembly platforms
.............................

The WebAssembly(1) platforms ‘wasm32-emscripten’ (Emscripten(2)) and
‘wasm32-wasi’ (WASI(3)) provide a subset of POSIX APIs.  WebAssembly
runtimes and browsers are sandboxed and have limited access to the host
and external resources.  Any Python standard library module that uses
processes, threading, networking, signals, or other forms of
inter-process communication (IPC), is either not available or may not
work as on other Unix-like systems.  File I/O, file system, and Unix
permission-related functions are restricted, too.  Emscripten does not
permit blocking I/O. Other blocking operations like *note sleep(): 8ad.
block the browser event loop.

The properties and behavior of Python on WebAssembly platforms depend on
the Emscripten(4)-SDK or WASI(5)-SDK version, WASM runtimes (browser,
NodeJS, wasmtime(6)), and Python build time flags.  WebAssembly,
Emscripten, and WASI are evolving standards; some features like
networking may be supported in the future.

For Python in the browser, users should consider Pyodide(7) or
PyScript(8).  PyScript is built on top of Pyodide, which itself is built
on top of CPython and Emscripten.  Pyodide provides access to browsers”
JavaScript and DOM APIs as well as limited networking capabilities with
JavaScript’s ‘XMLHttpRequest’ and ‘Fetch’ APIs.

   * Process-related APIs are not available or always fail with an
     error.  That includes APIs that spawn new processes (*note fork():
     4b6, *note execve(): 1301.), wait for processes (*note waitpid():
     f9c.), send signals (*note kill(): 156f.), or otherwise interact
     with processes.  The *note subprocess: dc. is importable but does
     not work.

   * The *note socket: d1. module is available, but is limited and
     behaves differently from other platforms.  On Emscripten, sockets
     are always non-blocking and require additional JavaScript code and
     helpers on the server to proxy TCP through WebSockets; see
     Emscripten Networking(9) for more information.  WASI snapshot
     preview 1 only permits sockets from an existing file descriptor.

   * Some functions are stubs that either don’t do anything and always
     return hardcoded values.

   * Functions related to file descriptors, file permissions, file
     ownership, and links are limited and don’t support some operations.
     For example, WASI does not permit symlinks with absolute file
     names.

   ---------- Footnotes ----------

   (1) https://webassembly.org/

   (2) https://emscripten.org/

   (3) https://wasi.dev/

   (4) https://emscripten.org/

   (5) https://wasi.dev/

   (6) https://wasmtime.dev/

   (7) https://pyodide.org/

   (8) https://pyscript.net/

   (9) https://emscripten.org/docs/porting/networking.html


File: python.info,  Node: Mobile platforms,  Prev: WebAssembly platforms,  Up: Notes on availability

5.1.1.2 Mobile platforms
........................

Android and iOS are, in most respects, POSIX operating systems.  File
I/O, socket handling, and threading all behave as they would on any
POSIX operating system.  However, there are several major differences:

   * Mobile platforms can only use Python in «embedded» mode.  There is
     no Python REPL, and no ability to use separate executables such as
     ‘python’ or ‘pip’.  To add Python code to your mobile app, you must
     use the *note Python embedding API: 2244.  For more details, see
     *note Using Python on Android: 2242. and *note Using Python on iOS:
     224a.

   * Subprocesses:

        * On Android, creating subprocesses is possible but officially
          unsupported(1).  In particular, Android does not support any
          part of the System V IPC API, so *note multiprocessing: 98. is
          not available.

        * An iOS app cannot use any form of subprocessing,
          multiprocessing, or inter-process communication.  If an iOS
          app attempts to create a subprocess, the process creating the
          subprocess will either lock up, or crash.  An iOS app has no
          visibility of other applications that are running, nor any
          ability to communicate with other running applications,
          outside of the iOS-specific APIs that exist for this purpose.

   * Mobile apps have limited access to modify system resources (such as
     the system clock).  These resources will often be 'readable', but
     attempts to modify those resources will usually fail.

   * Console input and output:

        * On Android, the native ‘stdout’ and ‘stderr’ are not connected
          to anything, so Python installs its own streams which redirect
          messages to the system log.  These can be seen under the tags
          ‘python.stdout’ and ‘python.stderr’ respectively.

        * iOS apps have a limited concept of console output.  ‘stdout’
          and ‘stderr’ 'exist', and content written to ‘stdout’ and
          ‘stderr’ will be visible in logs when running in Xcode, but
          this content 'won’t' be recorded in the system log.  If a user
          who has installed your app provides their app logs as a
          diagnostic aid, they will not include any detail written to
          ‘stdout’ or ‘stderr’.

        * Mobile apps have no usable ‘stdin’ at all.  While apps can
          display an on-screen keyboard, this is a software feature, not
          something that is attached to ‘stdin’.

          As a result, Python modules that involve console manipulation
          (such as *note curses: 2f. and *note readline: bf.) are not
          available on mobile platforms.

   ---------- Footnotes ----------

   (1) https://issuetracker.google.com/issues/128554619#comment4


File: python.info,  Node: Funzioni Incorporate,  Next: Built-in Constants,  Prev: Introduction<5>,  Up: The Python Standard Library

5.2 Funzioni Incorporate
========================

L’interprete Python ha un certo numero di funzioni e tipi incorporati
che sono sempre disponibili.  Sono elencati qui in ordine alfabetico.

Funzioni Incorporate

--------------------------------------------------------------------------------------------------------------------
                                                                                      
     'A'                           'E'                         'L'                         'R'
     *note abs(): 2077.            *note enumerate(): 1688.     *note len(): 841.          *note range(): 2598.
     *note aiter(): 9d7.           *note eval(): 4a4.          *note list(): 2596.         *note repr(): 1c1.
     *note all(): 1629.            *note exec(): 4a3.          *note locals(): 46f.        *note reversed(): a67.
     *note anext(): 9d8.                                                                   *note round(): 14e2.
     *note any(): 1628.            'F'                         'M'                         
     *note ascii(): 15ed.          *note filter(): a66.        *note map(): 19f.           'S'
                                   *note float(): 196.         *note max(): 110e.          *note set(): 2599.
     'B'                           *note format(): 199.        *note memoryview(): 2597.     *note setattr(): 259a.
     *note bin(): 14b0.            *note frozenset(): 2595.     *note min(): 110d.         *note slice(): 695.
     *note bool(): 3c3.                                                                    *note sorted(): dc9.
     *note breakpoint(): 271.      'G'                         'N'                         *note staticmethod(): 453.
     *note bytearray(): 1e83.      *note getattr(): dcc.       *note next(): 9da.          *note str(): 259b.
     *note bytes(): 1e82.          *note globals(): 1bf2.                                  *note sum(): 696.
                                                               'O'                         *note super(): 1a6.
     'C'                           'H'                         *note object(): c80.        
     *note callable(): 13ce.       *note hasattr(): 6fa.       *note oct(): 14d6.          'T'
     *note chr(): 19d7.            *note hash(): 802.          *note open(): 316.          *note tuple(): 259c.
     *note classmethod(): 48f.     *note help(): ad6.          *note ord(): 2323.          *note type(): f46.
     *note compile(): 4b2.         *note hex(): 14d7.                                      
     *note complex(): 197.                                     'P'                         'V'
                                   'I'                         *note pow(): 1a4.           *note vars(): 1e0b.
     'D'                           *note id(): 162a.           *note print(): 1177.        
     *note delattr(): 2593.        *note input(): 14e0.        *note property(): 4b4.      'Z'
     *note dict(): 2594.           *note int(): 19b.                                       *note zip(): 1a0.
     *note dir(): 845.             *note isinstance(): 2ad.                                
     *note divmod(): b9b.          *note issubclass(): 9c6.                                '_'
                                   *note iter(): 9d9.                                      *note __import__(): ad3.
                                                                                      

 -- Funzione: abs (number, /)

     Return the absolute value of a number.  The argument may be an
     integer, a floating-point number, or an object implementing *note
     __abs__(): 23e8.  If the argument is a complex number, its
     magnitude is returned.

 -- Funzione: aiter (async_iterable, /)

     Restituisce un *note asynchronous iterator: 4c8. per un *note
     asynchronous iterable: f76.  Equivalente a chiamare
     ‘x.__aiter__()’.

     Nota: A differenza di *note iter(): 9d9, *note aiter(): 9d7. non ha
     una variante con 2 argomenti.

     Added in version 3.10.

 -- Funzione: all (iterable, /)

     Restituisce ‘True’ se tutti gli elementi dell”'iterable' sono veri
     (o se l’iterable è vuoto).  Equivalente a:

          def all(iterable):
              for element in iterable:
                  if not element:
                      return False
              return True

 -- Funzione: awaitable anext (async_iterator, /)

 -- Funzione: awaitable anext (async_iterator, default, /)

     Quando viene atteso, restituisce l’elemento successivo dall”*note
     asynchronous iterator: 4c8. dato, o 'default' se fornito e
     l’iteratore è esaurito.

     Questa è la variante asincrona del builtin *note next(): 9da, e si
     comporta in modo simile.

     Questo chiama il metodo *note __anext__(): 186a. di
     'async_iterator', restituendo un *note awaitable: 4ca.  Attendere
     questo restituisce il prossimo valore dell’iteratore.  Se 'default'
     è fornito, viene restituito se l’iteratore è esaurito, altrimenti
     viene sollevata l’eccezione *note StopAsyncIteration: 1df7.

     Added in version 3.10.

 -- Funzione: any (iterable, /)

     Restituisce ‘True’ se qualche elemento dell”'iterable' è vero.  Se
     l’iterable è vuoto, restituisce ‘False’.  Equivalente a:

          def any(iterable):
              for element in iterable:
                  if element:
                      return True
              return False

 -- Funzione: ascii (object, /)

     Come *note repr(): 1c1, restituisce una stringa contenente una
     rappresentazione stampabile di un oggetto, ma escapa i caratteri
     non ASCII nella stringa restituita da *note repr(): 1c1.
     utilizzando le sequenze di escape ‘\x’, ‘\u’ o ‘\U’.  Ciò genera
     una stringa simile a quella restituita da *note repr(): 1c1. in
     Python 2.

 -- Funzione: bin (integer, /)

     Convert an integer number to a binary string prefixed with «0b».
     The result is a valid Python expression.  If 'integer' is not a
     Python *note int: 19b. object, it has to define an *note
     __index__(): 19e. method that returns an integer.  Some examples:

          >>> bin(3)
          '0b11'
          >>> bin(-10)
          '-0b1010'

     Se si desidera il prefisso «0b» oppure no, è possibile utilizzare
     uno dei seguenti modi.

          >>> format(14, '#b'), format(14, 'b')
          ('0b1110', '1110')
          >>> f'{14:#b}', f'{14:b}'
          ('0b1110', '1110')

     See also *note enum.bin(): 1775. to represent negative values as
     twos-complement.

     Vedi anche *note format(): 199. per maggiori informazioni.

 -- Classe: bool (object=False, /)

     Return a Boolean value, i.e.  one of ‘True’ or ‘False’.  The
     argument is converted using the standard *note truth testing
     procedure: 1840.  If the argument is false or omitted, this returns
     ‘False’; otherwise, it returns ‘True’.  The *note bool: 3c3. class
     is a subclass of *note int: 19b. (see *note Tipi Numerici — int,
     float, complex: 1fc4.).  It cannot be subclassed further.  Its only
     instances are ‘False’ and ‘True’ (see *note Tipo Booleano - bool:
     259d.).

     Cambiato nella versione 3.7: The parameter is now positional-only.

 -- Funzione: breakpoint (*args, **kws)

     This function drops you into the debugger at the call site.
     Specifically, it calls *note sys.breakpointhook(): cd3, passing
     ‘args’ and ‘kws’ straight through.  By default,
     ‘sys.breakpointhook()’ calls *note pdb.set_trace(): 272. expecting
     no arguments.  In this case, it is purely a convenience function so
     you don’t have to explicitly import *note pdb: aa. or type as much
     code to enter the debugger.  However, *note sys.breakpointhook():
     cd3. can be set to some other function and *note breakpoint(): 271.
     will automatically call that, allowing you to drop into the
     debugger of choice.  If *note sys.breakpointhook(): cd3. is not
     accessible, this function will raise *note RuntimeError: 244.

     Per impostazione predefinita, il comportamento di *note
     breakpoint(): 271. può essere modificato con la variabile
     d’ambiente *note PYTHONBREAKPOINT: cd4.  Vedi *note
     sys.breakpointhook(): cd3. per i dettagli d’uso.

     Nota che ciò non è garantito se *note sys.breakpointhook(): cd3. è
     stato sostituito.

     Solleva un *note evento di auditing: 1c56. ‘builtins.breakpoint’
     con l’argomento ‘breakpointhook’.

     Added in version 3.7.

 -- Classe: bytearray (source=b'')

 -- Classe: bytearray (source, encoding, errors='strict')

     Restituisce un nuovo array di byte.  La classe *note bytearray:
     344. è una sequenza mutabile di interi nell’intervallo 0 <= x <
     256.  Ha la maggior parte dei metodi usuali delle sequenze
     mutabili, descritti in *note Tipi di Sequenza Mutabili: 259e, oltre
     alla maggior parte dei metodi che il tipo *note bytes: 192. ha,
     vedi *note Operazioni su Bytes e Bytearray: 259f.

     Il parametro opzionale 'source' può essere utilizzato per
     inizializzare l’array in diversi modi:

        * Se è una 'string', devi anche dare i parametri 'encoding' (e
          facoltativamente, 'errors'); *note bytearray(): 344. quindi
          converte la stringa in byte utilizzando *note str.encode():
          ad4.

        * Se è un 'integer', l’array avrà quella dimensione e sarà
          inizializzato con byte nulli.

        * Se è un oggetto conforme all”*note interfaccia buffer: 260, un
          buffer di sola lettura dell’oggetto sarà utilizzato per
          inizializzare l’array di byte.

        * Se è un 'iterable', deve essere un iterable di interi
          nell’intervallo ‘0 <= x < 256’, che sono usati come contenuto
          iniziale dell’array.

     Senza un argomento, viene creato un array di dimensione 0.

     Vedi anche *note Tipi di sequenze binarie — bytes, bytearray,
     memoryview: 25a0. e *note Oggetti Bytearray: 25a1.

 -- Classe: bytes (source=b'')

 -- Classe: bytes (source, encoding, errors='strict')

     Restituisce un nuovo oggetto «bytes» che è una sequenza immutabile
     di interi nell’intervallo ‘0 <= x < 256’.  *note bytes: 192. è una
     versione immutabile di *note bytearray: 344. – ha gli stessi metodi
     non mutanti e lo stesso comportamento di indicizzazione e slicing.

     Di conseguenza, gli argomenti del costruttore sono interpretati
     come per *note bytearray(): 344.

     Gli oggetti byte possono essere creati anche con letterali, vedi
     *note String and Bytes literals: 2288.

     Vedi anche *note Tipi di sequenze binarie — bytes, bytearray,
     memoryview: 25a0, *note Oggetti bytes: 25a2, e *note Operazioni su
     Bytes e Bytearray: 259f.

 -- Funzione: callable (object, /)

     Restituisce *note True: e09. se l’argomento 'object' appare
     chiamabile, *note False: d2d. se non lo è.  Se questo restituisce
     ‘True’, è ancora possibile che una chiamata fallisca, ma se è
     ‘False’, chiamare 'object' non avrà mai successo.  Nota che le
     classi sono chiamabili (chiamare una classe restituisce una nuova
     istanza); le istanze sono chiamabili se la loro classe ha un metodo
     *note __call__(): 77b.

     Added in version 3.2: Questa funzione è stata prima rimossa in
     Python 3.0 e poi reintegrata in Python 3.2.

 -- Funzione: chr (codepoint, /)

     Return the string representing a character with the specified
     Unicode code point.  For example, ‘chr(97)’ returns the string
     ‘'a'’, while ‘chr(8364)’ returns the string ‘'€'’.  This is the
     inverse of *note ord(): 2323.

     The valid range for the argument is from 0 through 1,114,111
     (0x10FFFF in base 16).  *note ValueError: 2ec. will be raised if it
     is outside that range.

 -- Funzione: @classmethod

     Trasforma un metodo in un metodo di classe.

     Un metodo di classe riceve la classe come primo argomento
     implicito, proprio come un metodo di istanza riceve l’istanza.  Per
     dichiarare un metodo di classe, utilizza questo idiom:

          class C:
              @classmethod
              def f(cls, arg1, arg2): ...

     La forma ‘@classmethod’ è un *note decorator: 93b. di funzione –
     vedi *note Function definitions: 2002. per i dettagli.

     Un metodo di classe può essere chiamato sia sulla classe (come
     ‘C.f()’) sia su un’istanza (come ‘C().f()’).  L’istanza è ignorata
     tranne che per la sua classe.  Se un metodo di classe è chiamato
     per una classe derivata, l’oggetto della classe derivata è passato
     come primo argomento implicito.

     I metodi di classe sono diversi dai metodi statici di C++ o Java.
     Se desideri quelli, vedi *note staticmethod(): 453. in questa
     sezione.  Per maggiori informazioni sui metodi di classe, vedi
     *note The standard type hierarchy: 2318.

     Cambiato nella versione 3.9: I metodi di classe ora possono
     avvolgere altri *note descrittori: 1869. come *note property():
     4b4.

     Cambiato nella versione 3.10: Class methods now inherit the method
     attributes (*note __module__: 2331, *note __name__: 14dc, *note
     __qualname__: 2330, *note __doc__: 13e1. and *note __annotations__:
     13e0.) and have a new ‘__wrapped__’ attribute.

     Deprecated since version 3.11, removed in version 3.13: I metodi di
     classe non possono più avvolgere altri *note descrittori: 1869.
     come *note property(): 4b4.

 -- Funzione: compile (source, filename, mode, flags=0,
          dont_inherit=False, optimize=-1)

     Compila il 'source' in un oggetto codice o AST. Gli oggetti codice
     possono essere eseguiti da *note exec(): 4a3. o *note eval(): 4a4.
     'source' può essere una stringa normale, una stringa di byte o un
     oggetto AST. Consulta la documentazione del modulo *note ast: 9.
     per informazioni su come lavorare con gli oggetti AST.

     L’argomento 'filename' dovrebbe indicare il file da cui il codice è
     stato letto; passa un valore riconoscibile se non è stato letto da
     un file (‘'<string>'’ è comunemente utilizzato).

     L’argomento 'mode' specifica il tipo di codice che deve essere
     compilato; può essere ‘'exec'’ se 'source' è costituito da una
     sequenza di istruzioni, ‘'eval'’ se è costituito da una singola
     espressione, o ‘'single'’ se è costituito da una singola istruzione
     interattiva (in quest’ultimo caso, le istruzioni di espressione che
     valutano a qualcosa di diverso da ‘None’ saranno stampate).

     Gli argomenti opzionali 'flags' e 'dont_inherit' controllano quali
     *note opzioni del compilatore: 25a3. devono essere attivate e quali
     *note future features: 45d. dovrebbero essere consentite.  Se
     nessuno dei due è presente (o entrambi sono zero), il codice viene
     compilato con le stesse opzioni che influenzano il codice che
     chiama *note compile(): 4b2.  Se l’argomento 'flags' è fornito e
     'dont_inherit' non è (o è zero) allora le opzioni del compilatore e
     le dichiarazioni future specificate dall’argomento 'flags' vengono
     utilizzate in aggiunta a quelle che sarebbero comunque utilizzate.
     Se 'dont_inherit' è un numero intero diverso da zero, l’argomento
     'flags' è quello – le opzioni del compilatore (future features e
     opzioni del compilatore) nel codice circostante sono ignorate.

     Le opzioni del compilatore e le dichiarazioni future sono
     specificate da bit che possono essere combinati con l’operatore OR
     bit a bit per specificare più opzioni.  Il campo di bit richiesto
     per specificare una particolare future feature può essere trovato
     come attributo *note compiler_flag: 2379. sull’istanza *note
     _Feature: 25a4. nel modulo *note __future__: 0.  Le *note flag del
     compilatore: 25a3. possono essere trovate nel modulo *note ast: 9,
     con il prefisso ‘PyCF_’.

     L’argomento 'optimize' specifica il livello di ottimizzazione del
     compilatore; il valore predefinito ‘-1’ seleziona il livello di
     ottimizzazione dell’interprete come indicato dalle opzioni *note
     -O: 18c.  I livelli espliciti sono ‘0’ (nessuna ottimizzazione;
     ‘__debug__’ è vero), ‘1’ (gli assert vengono rimossi, ‘__debug__’ è
     falso) o ‘2’ (anche i docstring vengono rimossi).

     This function raises *note SyntaxError: 18e. or *note ValueError:
     2ec. if the compiled source is invalid.

     Se vuoi fare il parsing del codice Python nella sua
     rappresentazione AST, vedi *note ast.parse(): 1c2.

     Solleva un *note evento di auditing: 1c56. ‘compile’ con argomenti
     ‘source’ e ‘filename’.  Questo evento può essere sollevato anche
     dalla compilazione implicita.

          Nota: Quando si compila una stringa con codice multi-linea in
          modalità ‘'single'’ o ‘'eval'’, l’input deve essere terminato
          da almeno un carattere di nuova riga.  Questo per facilitare
          il rilevamento delle istruzioni incomplete e complete nel
          modulo *note code: 1b.

          Avvertimento: È possibile mandare in crash l’interprete Python
          con una stringa sufficientemente grande/complessa quando si
          compila in un oggetto AST a causa delle limitazioni della
          profondità dello stack del compilatore AST di Python.

     Cambiato nella versione 3.2: Consentito l’uso delle newline di
     Windows e Mac.  Inoltre, l’input in modalità ‘'exec'’ non deve più
     terminare con una newline.  Aggiunto il parametro 'optimize'.

     Cambiato nella versione 3.5: In precedenza, veniva sollevata
     un’eccezione *note TypeError: 198. quando venivano incontrati byte
     nulli nella sorgente.

     Added in version 3.8: ‘ast.PyCF_ALLOW_TOP_LEVEL_AWAIT’ può ora
     essere passato in flags per abilitare il supporto per ‘await’,
     ‘async for’ e ‘async with’ al livello superiore.

 -- Classe: complex (number=0, /)

 -- Classe: complex (string, /)

 -- Classe: complex (real=0, imag=0)

     Convert a single string or number to a complex number, or create a
     complex number from real and imaginary parts.

     Examples:

          >>> complex('+1.23')
          (1.23+0j)
          >>> complex('-4.5j')
          -4.5j
          >>> complex('-1.23+4.5j')
          (-1.23+4.5j)
          >>> complex('\t( -1.23+4.5J )\n')
          (-1.23+4.5j)
          >>> complex('-Infinity+NaNj')
          (-inf+nanj)
          >>> complex(1.23)
          (1.23+0j)
          >>> complex(imag=-4.5)
          -4.5j
          >>> complex(-1.23, 4.5)
          (-1.23+4.5j)

     If the argument is a string, it must contain either a real part (in
     the same format as for *note float(): 196.) or an imaginary part
     (in the same format but with a ‘'j'’ or ‘'J'’ suffix), or both real
     and imaginary parts (the sign of the imaginary part is mandatory in
     this case).  The string can optionally be surrounded by whitespaces
     and the round parentheses ‘'('’ and ‘')'’, which are ignored.  The
     string must not contain whitespace between ‘'+'’, ‘'-'’, the ‘'j'’
     or ‘'J'’ suffix, and the decimal number.  For example,
     ‘complex('1+2j')’ is fine, but ‘complex('1 + 2j')’ raises *note
     ValueError: 2ec.  More precisely, the input must conform to the
     *note complexvalue: 25a5. production rule in the following grammar,
     after parentheses and leading and trailing whitespace characters
     are removed:

          complexvalue: *note floatvalue: 25a6. |
                        *note floatvalue: 25a6. ("j" | "J") |
                        *note floatvalue: 25a6. *note sign: 25a7. *note absfloatvalue: 25a8. ("j" | "J")

     If the argument is a number, the constructor serves as a numeric
     conversion like *note int: 19b. and *note float: 196.  For a
     general Python object ‘x’, ‘complex(x)’ delegates to
     ‘x.__complex__()’.  If *note __complex__(): 7fe. is not defined
     then it falls back to *note __float__(): bc3.  If ‘__float__()’ is
     not defined then it falls back to *note __index__(): 19e.

     If two arguments are provided or keyword arguments are used, each
     argument may be any numeric type (including complex).  If both
     arguments are real numbers, return a complex number with the real
     component 'real' and the imaginary component 'imag'.  If both
     arguments are complex numbers, return a complex number with the
     real component ‘real.real-imag.imag’ and the imaginary component
     ‘real.imag+imag.real’.  If one of arguments is a real number, only
     its real component is used in the above expressions.

     See also *note complex.from_number(): 195. which only accepts a
     single numeric argument.

     If all arguments are omitted, returns ‘0j’.

     Il tipo complesso è descritto in *note Tipi Numerici — int, float,
     complex: 1fc4.

     Cambiato nella versione 3.6: È consentito raggruppare le cifre con
     trattini bassi come nei letterali di codice.

     Cambiato nella versione 3.8: Ricade su *note __index__(): 19e. se
     *note __complex__(): 7fe. e *note __float__(): bc3. non sono
     definiti.

     Deprecato dalla versione 3.14: Passing a complex number as the
     'real' or 'imag' argument is now deprecated; it should only be
     passed as a single positional argument.

 -- Funzione: delattr (object, name, /)

     Questo è un parente di *note setattr(): 259a.  Gli argomenti sono
     un oggetto e una stringa.  La stringa deve essere il nome di uno
     degli attributi dell’oggetto.  La funzione elimina l’attributo
     denominato, a condizione che l’oggetto lo permetta.  Ad esempio,
     ‘delattr(x, 'foobar')’ è equivalente a ‘del x.foobar’.  'name' non
     deve necessariamente essere un identificatore Python (vedi *note
     setattr(): 259a.).

 -- Classe: dict (**kwargs)

 -- Classe: dict (mapping, /, **kwargs)

 -- Classe: dict (iterable, /, **kwargs)

     Crea un nuovo dizionario.  L’oggetto *note dict: 183. è la classe
     del dizionario.  Vedi *note dict: 183. e *note Tipi di Mapping —
     dict: cbf. per la documentazione su questa classe.

     Per altri contenitori vedere le classi integrate *note list: 24d,
     *note set: 184. e *note tuple: 614, così come il modulo *note
     collections: 1e.

 -- Funzione: dir ()

 -- Funzione: dir (object, /)

     Senza argomenti, restituisce l’elenco dei nomi nell’attuale ambito
     locale.  Con un argomento, tenta di restituire un elenco di
     attributi validi per quell’oggetto.

     Se l’oggetto ha un metodo chiamato *note __dir__(): 17ca, verrà
     chiamato e deve restituire l’elenco degli attributi.  Questo
     consente agli oggetti che implementano una funzione personalizzata
     *note __getattr__(): 6fb. o *note __getattribute__(): dcd. di
     personalizzare il modo in cui *note dir(): 845. riporta i loro
     attributi.

     Se l’oggetto non fornisce *note __dir__(): 17ca, la funzione fa del
     suo meglio per raccogliere informazioni dall’attributo *note
     __dict__: 77e. dell’oggetto, se definito, e dal suo tipo di
     oggetto.  L’elenco risultante non è necessariamente completo e può
     essere inaccurato se l’oggetto ha una funzione personalizzata *note
     __getattr__(): 6fb.

     Il meccanismo predefinito di *note dir(): 845. si comporta
     diversamente con diversi tipi di oggetti, poiché tenta di produrre
     le informazioni più rilevanti, piuttosto che complete:

        * Se l’oggetto è un oggetto modulo, l’elenco contiene i nomi
          degli attributi del modulo.

        * Se l’oggetto è un oggetto di tipo o classe, l’elenco contiene
          i nomi dei suoi attributi e, ricorsivamente, degli attributi
          delle sue basi.

        * Altrimenti, l’elenco contiene i nomi degli attributi
          dell’oggetto, i nomi degli attributi della sua classe e,
          ricorsivamente, degli attributi delle sue classi base.

     L’elenco risultante è ordinato alfabeticamente.  Ad esempio:

          >>> import struct
          >>> dir()   # show the names in the module namespace
          ['__builtins__', '__name__', 'struct']
          >>> dir(struct)   # show the names in the struct module
          ['Struct', '__all__', '__builtins__', '__cached__', '__doc__', '__file__',
           '__initializing__', '__loader__', '__name__', '__package__',
           '_clearcache', 'calcsize', 'error', 'pack', 'pack_into',
           'unpack', 'unpack_from']
          >>> class Shape:
          ...     def __dir__(self):
          ...         return ['area', 'perimeter', 'location']
          ...
          >>> s = Shape()
          >>> dir(s)
          ['area', 'location', 'perimeter']

          Nota: Poiché *note dir(): 845. è fornito principalmente come
          praticità per l’uso in un prompt interattivo, tenta di fornire
          un insieme di nomi interessante piuttosto che un insieme
          definito rigorosamente o coerentemente, e il suo comportamento
          dettagliato può cambiare tra le versioni.  Ad esempio, gli
          attributi delle metaclassi non sono nella lista dei risultati
          quando l’argomento è una classe.

 -- Funzione: divmod (a, b, /)

     Take two (non-complex) numbers as arguments and return a pair of
     numbers consisting of their quotient and remainder when using
     integer division.  With mixed operand types, the rules for binary
     arithmetic operators apply.  For integers, the result is the same
     as ‘(a // b, a % b)’.  For floating-point numbers the result is
     ‘(q, a % b)’, where 'q' is usually ‘math.floor(a / b)’ but may be 1
     less than that.  In any case ‘q * b + a % b’ is very close to 'a',
     if ‘a % b’ is non-zero it has the same sign as 'b', and ‘0 <= abs(a
     % b) < abs(b)’.

 -- Funzione: enumerate (iterable, start=0)

     Restituisce un oggetto enumerate.  'iterable' deve essere una
     sequenza, un *note iterator: 4c9. o qualche altro oggetto che
     supporti l’iterazione.  Il metodo *note __next__(): 14d5.
     dell’iteratore restituito da *note enumerate(): 1688. restituisce
     una tupla contenente un conteggio (da 'start' che per impostazione
     predefinita è 0) e i valori ottenuti iterando su 'iterable'.

          >>> seasons = ['Spring', 'Summer', 'Fall', 'Winter']
          >>> list(enumerate(seasons))
          [(0, 'Spring'), (1, 'Summer'), (2, 'Fall'), (3, 'Winter')]
          >>> list(enumerate(seasons, start=1))
          [(1, 'Spring'), (2, 'Summer'), (3, 'Fall'), (4, 'Winter')]

     Equivalente a:

          def enumerate(iterable, start=0):
              n = start
              for elem in iterable:
                  yield n, elem
                  n += 1

 -- Funzione: eval (source, /, globals=None, locals=None)


     Parametri:

        * ‘source’ (*note str: 169. | *note code object: 4e7.) –
          Un’espressione Python.

        * ‘globals’ (*note dict: 183. | ‘None’) – Lo spazio dei nomi
          globale (predefinito: ‘None’).

        * ‘locals’ (*note mapping: 13c3. | ‘None’) – Lo spazio dei nomi
          locale (predefinito: ‘None’).


     Ritorna: Il risultato dell’espressione valutata.


     solleva: Gli errori di sintassi sono segnalati come eccezioni.

          Avvertimento: This function executes arbitrary code.  Calling
          it with user-supplied input may lead to security
          vulnerabilities.

     The 'source' argument is parsed and evaluated as a Python
     expression (technically speaking, a condition list) using the
     'globals' and 'locals' mappings as global and local namespace.  If
     the 'globals' dictionary is present and does not contain a value
     for the key ‘__builtins__’, a reference to the dictionary of the
     built-in module *note builtins: 13. is inserted under that key
     before 'source' is parsed.  That way you can control what builtins
     are available to the executed code by inserting your own
     ‘__builtins__’ dictionary into 'globals' before passing it to *note
     eval(): 4a4.  If the 'locals' mapping is omitted it defaults to the
     'globals' dictionary.  If both mappings are omitted, the source is
     executed with the 'globals' and 'locals' in the environment where
     *note eval(): 4a4. is called.  Note, 'eval()' will only have access
     to the *note nested scopes: 2373. (non-locals) in the enclosing
     environment if they are already referenced in the scope that is
     calling *note eval(): 4a4. (e.g.  via a *note nonlocal: 14af.
     statement).

     Esempio:

          >>> x = 1
          >>> eval('x+1')
          2

     Questa funzione può essere utilizzata anche per eseguire oggetti
     codice arbitrari (come quelli creati da *note compile(): 4b2.).  In
     questo caso, passa un oggetto codice invece di una stringa.  Se
     l’oggetto codice è stato compilato con ‘'exec'’ come argomento
     'mode', il valore restituito da *note eval(): 4a4. sarà ‘None’.

     Suggerimenti: l’esecuzione dinamica delle istruzioni è supportata
     dalla funzione *note exec(): 4a3.  Le funzioni *note globals():
     1bf2. e *note locals(): 46f. restituiscono rispettivamente il
     dizionario globale e locale corrente, che possono essere utili da
     passare per l’uso da parte di *note eval(): 4a4. o *note exec():
     4a3.

     Se la sorgente data è una stringa, allora gli spazi e le
     tabulazioni iniziali e finali vengono rimossi.

     Vedi *note ast.literal_eval(): e14. per una funzione che può
     valutare in sicurezza stringhe con espressioni contenenti solo
     letterali.

     Solleva un *note evento di auditing: 1c56. ‘exec’ con l’oggetto
     codice come argomento.  Possono anche essere sollevati eventi di
     compilazione del codice.

     Cambiato nella versione 3.13: Gli argomenti 'globals' e 'locals'
     possono ora essere passati come parole chiave.

     Cambiato nella versione 3.13: La semantica dello spazio dei nomi
     'locals' predefinito è stata modificata come descritto peril
     builtin *note locals(): 46f.

 -- Funzione: exec (source, /, globals=None, locals=None, *,
          closure=None)

          Avvertimento: This function executes arbitrary code.  Calling
          it with user-supplied input may lead to security
          vulnerabilities.

     Questa funzione supporta l’esecuzione dinamica di codice Python.
     'source' deve essere una stringa o un oggetto codice.  Se è una
     stringa, la stringa viene analizzata come una suite di istruzioni
     Python che viene quindi eseguita (a meno che non si verifichi un
     errore di sintassi).  (1)  Se è un oggetto codice, viene
     semplicemente eseguito.  In tutti i casi, il codice eseguito è
     previsto come input di file valido (vedi la sezione *note File
     input: 257a. nel Manuale di Riferimento).  Tieni presente che le
     istruzioni *note nonlocal: 14af, *note yield: bc4. e *note return:
     1af. non possono essere utilizzate al di fuori delle definizioni
     delle funzioni anche all’interno del contesto del codice passato
     alla funzione *note exec(): 4a3.  Il valore restituito è ‘None’.

     In ogni caso, se vengono omesse le parti opzionali, il codice viene
     eseguito nell’ambito corrente.  Se viene fornito solo 'globals',
     deve essere un dizionario (e non una sottoclasse del dizionario),
     che verrà utilizzato sia per le variabili globali che per quelle
     locali.  Se vengono forniti 'globals' e 'locals', vengono
     utilizzati rispettivamente per le variabili globali e locali.  Se
     fornito, 'locals' può essere qualsiasi oggetto di mappatura.
     Ricorda che a livello di modulo, globals e locals sono lo stesso
     dizionario.

          Nota: Quando ‘exec’ ottiene due oggetti separati come
          'globals' e 'locals', il codice verrà eseguito come se fosse
          incorporato in una definizione di classe.  Ciò significa che
          le funzioni e le classi definite nel codice eseguito non
          potranno accedere alle variabili assegnate a livello di alto
          (poiché le variabili «di alto livello» sono trattate come
          variabili di classe in una definizione di classe).

     Se il dizionario 'globals' non contiene un valore per la chiave
     ‘__builtins__’, viene inserito un riferimento al dizionario del
     modulo integrato *note builtins: 13. sotto quella chiave.  In
     questo modo puoi controllare quali builtins sono disponibili per il
     codice eseguito inserendo il tuo dizionario ‘__builtins__’ in
     'globals' prima di passarlo a *note exec(): 4a3.

     The 'closure' argument specifies a closure–a tuple of cellvars.
     It’s only valid when the 'object' is a code object containing *note
     free (closure) variables: 187b.  The length of the tuple must
     exactly match the length of the code object’s *note co_freevars:
     232e. attribute.

     Solleva un *note evento di auditing: 1c56. ‘exec’ con l’oggetto
     codice come argomento.  Possono anche essere sollevati eventi di
     compilazione del codice.

          Nota: Le funzioni integrate *note globals(): 1bf2. e *note
          locals(): 46f. restituiscono rispettivamente l’attuale spazio
          dei nomi globale e locale, che possono essere utili da passare
          come secondo e terzo argomento a *note exec(): 4a3.

          Nota: Il 'locals' predefinito agisce come descritto per la
          funzione *note locals(): 46f. di seguito.  Passa un dizionario
          'locals' esplicito se hai bisogno di vedere gli effetti del
          codice su 'locals' dopo che la funzione *note exec(): 4a3.
          restituisce.

     Cambiato nella versione 3.11: Aggiunto il parametro 'closure'.

     Cambiato nella versione 3.13: Gli argomenti 'globals' e 'locals'
     possono ora essere passati come parole chiave.

     Cambiato nella versione 3.13: La semantica dello spazio dei nomi
     'locals' predefinito è stata modificata come descritto peril
     builtin *note locals(): 46f.

 -- Funzione: filter (function, iterable, /)

     Costruisce un iteratore dagli elementi di 'iterable' per i quali
     'function' è vera.  'iterable' può essere una sequenza, un
     contenitore che supporta l’iterazione, o un iteratore.  Se
     'function' è ‘None’, si assume la funzione identità, ovvero, tutti
     gli elementi di 'iterable' che sono falsi vengono rimossi.

     Nota che ‘filter(function, iterable)’ è equivalente all’espressione
     generatrice ‘(item for item in iterable if function(item))’ se
     function non è ‘None’ e ‘(item for item in iterable if item)’ se
     function è ‘None’.

     Vedi *note itertools.filterfalse(): 25aa. per la funzione
     complementare che restituisce elementi di 'iterable' per i quali
     'function' è falsa.

 -- Classe: float (number=0.0, /)

 -- Classe: float (string, /)

     Return a floating-point number constructed from a number or a
     string.

     Examples:

          >>> float('+1.23')
          1.23
          >>> float('   -12345\n')
          -12345.0
          >>> float('1e-003')
          0.001
          >>> float('+1E6')
          1000000.0
          >>> float('-Infinity')
          -inf

     If the argument is a string, it should contain a decimal number,
     optionally preceded by a sign, and optionally embedded in
     whitespace.  The optional sign may be ‘'+'’ or ‘'-'’; a ‘'+'’ sign
     has no effect on the value produced.  The argument may also be a
     string representing a NaN (not-a-number), or positive or negative
     infinity.  More precisely, the input must conform to the *note
     floatvalue: 25a6. production rule in the following grammar, after
     leading and trailing whitespace characters are removed:

          sign:          "+" | "-"
          infinity:      "Infinity" | "inf"
          nan:           "nan"
          digit:         <a Unicode decimal digit, i.e. characters in Unicode general category Nd>
          digitpart:     *note digit: 25ad. (["_"] *note digit: 25ad.)*
          number:        [*note digitpart: 25ae.] "." *note digitpart: 25ae. | *note digitpart: 25ae. ["."]
          exponent:      ("e" | "E") [*note sign: 25a7.] *note digitpart: 25ae.
          floatnumber:   *note number: 25af. [*note exponent: 25b0.]
          absfloatvalue: *note floatnumber: 25b1. | *note infinity: 25ab. | *note nan: 25ac.
          floatvalue:    [*note sign: 25a7.] *note absfloatvalue: 25a8.

     La distinzione tra maiuscole e minuscole non è significativa,
     quindi, per esempio, «inf», «Inf», «INFINITY» e «iNfINity» sono
     tutte ortografie accettabili per l’infinito positivo.

     Otherwise, if the argument is an integer or a floating-point
     number, a floating-point number with the same value (within
     Python’s floating-point precision) is returned.  If the argument is
     outside the range of a Python float, an *note OverflowError: a83.
     will be raised.

     Per un oggetto Python generico ‘x’, ‘float(x)’ si delega a
     ‘x.__float__()’.  Se *note __float__(): bc3. non è definito, si
     ritorna a *note __index__(): 19e.

     See also *note float.from_number(): 194. which only accepts a
     numeric argument.

     Se non viene fornito alcun argomento, viene restituito ‘0.0’.

     Il tipo float è descritto in *note Tipi Numerici — int, float,
     complex: 1fc4.

     Cambiato nella versione 3.6: È consentito raggruppare le cifre con
     trattini bassi come nei letterali di codice.

     Cambiato nella versione 3.7: The parameter is now positional-only.

     Cambiato nella versione 3.8: Ritorna a *note __index__(): 19e. se
     *note __float__(): bc3. non è definito.

 -- Funzione: format (value, format_spec='', /)

     Converte un 'value' in una rappresentazione «formattata», come
     controllato da 'format_spec'.  L’interpretazione di 'format_spec'
     dipenderà dal tipo dell’argomento 'value'; tuttavia, esiste una
     sintassi di formattazione standard utilizzata dalla maggior parte
     dei tipi integrati: *note Format Specification Mini-Language: 4fa.

     Il 'format_spec' predefinito è una stringa vuota che di solito dà
     lo stesso effetto di una chiamata a *note str(value): 169.

     Una chiamata a ‘format(value, format_spec)’ viene tradotta in
     ‘type(value).__format__(value, format_spec)’ che bypassa il
     dizionario dell’istanza quando si cerca il metodo *note
     __format__(): 832. del valore.  Viene sollevata un’eccezione *note
     TypeError: 198. se la ricerca del metodo raggiunge *note object:
     c80. e 'format_spec' non è vuoto, o se 'format_spec' o il valore
     restituito non sono stringhe.

     Cambiato nella versione 3.4: ‘object().__format__(format_spec)’
     solleva *note TypeError: 198. se 'format_spec' non è una stringa
     vuota.

 -- Classe: frozenset (iterable=(), /)

     Restituisce un nuovo oggetto *note frozenset: 7f3, opzionalmente
     con elementi tratti da 'iterable'.  ‘frozenset’ è una classe
     integrata.  Vedi *note frozenset: 7f3. e *note Tipi di Insiemi —
     set, frozenset: 201b. per la documentazione su questa classe.

     Per altri contenitori vedere le classi integrate *note set: 184,
     *note list: 24d, *note tuple: 614. e *note dict: 183, così come il
     modulo *note collections: 1e.

 -- Funzione: getattr (object, name, /)

 -- Funzione: getattr (object, name, default, /)

     Restituisce il valore dell’attributo nominato di 'object'.  'name'
     deve essere una stringa.  Se la stringa è il nome di uno degli
     attributi dell’oggetto, il risultato è il valore di
     quell’attributo.  Ad esempio, ‘getattr(x, 'foobar')’ è equivalente
     a ‘x.foobar’.  Se l’attributo nominato non esiste, viene restituito
     'default' se fornito, altrimenti viene sollevata un’eccezione *note
     AttributeError: 5f0.  'name' non deve necessariamente essere un
     identificatore Python (vedi *note setattr(): 259a.).

          Nota: Poiché il *note private name mangling: 208d. avviene al
          momento della compilazione, è necessario manipolare
          manualmente il nome di un attributo privato (attributi con due
          underscore iniziali) per recuperarlo con *note getattr(): dcc.

 -- Funzione: globals ()

     Restituisce il dizionario che implementa lo spazio dei nomi del
     modulo corrente.  Per il codice all’interno delle funzioni, questo
     viene impostato quando la funzione è definita e rimane lo stesso
     indipendentemente da dove la funzione viene chiamata.

 -- Funzione: hasattr (object, name, /)

     Gli argomenti sono un oggetto e una stringa.  Il risultato è ‘True’
     se la stringa è il nome di uno degli attributi dell’oggetto,
     ‘False’ se non lo è.  (Questo è implementato chiamando
     ‘getattr(object, name)’ e verificando se solleva un’eccezione *note
     AttributeError: 5f0. o meno.)

 -- Funzione: hash (object, /)

     Restituisce il valore hash dell’oggetto (se ne ha uno).  I valori
     hash sono interi.  Vengono utilizzati per confrontare rapidamente
     le chiavi del dizionario durante una ricerca nel dizionario.  I
     valori numerici che risultano uguali hanno lo stesso valore hash
     (anche se sono di tipi diversi, come nel caso di 1 e 1.0).

          Nota: Per gli oggetti con metodi personalizzati *note
          __hash__(): cf5, si noti che *note hash(): 802. tronca il
          valore restituito in base alla larghezza di bit della macchina
          ospite.

 -- Funzione: help ()

 -- Funzione: help (request)

     Avvia il sistema di aiuto integrato.  (Questa funzione è destinata
     all’uso interattivo.)  Se non viene fornito alcun argomento, il
     sistema di aiuto interattivo si avvia sulla console
     dell’interprete.  Se l’argomento è una stringa, la stringa viene
     cercata come nome di un modulo, funzione, classe, metodo, parola
     chiave o argomento della documentazione, e viene stampata una
     pagina di aiuto sulla console.  Se l’argomento è di qualsiasi altro
     tipo di oggetto, viene generata una pagina di aiuto sull’oggetto.

     Si noti che se appare una barra (/) nell’elenco dei parametri di
     una funzione quando si invoca *note help(): ad6, significa che i
     parametri precedenti alla barra sono solo posizionali.  Per
     ulteriori informazioni, vedere *note la FAQ sugli argomenti solo
     posizionali: 25b2.

     Questa funzione viene aggiunta allo spazio dei nomi integrato dal
     modulo *note site: cc.

     Cambiato nella versione 3.4: Le modifiche a *note pydoc: ba. e
     *note inspect: 82. significano che le firme riportate per gli
     oggetti invocabili sono ora più complete e coerenti.

 -- Funzione: hex (integer, /)

     Convert an integer number to a lowercase hexadecimal string
     prefixed with «0x».  If 'integer' is not a Python *note int: 19b.
     object, it has to define an *note __index__(): 19e. method that
     returns an integer.  Some examples:

          >>> hex(255)
          '0xff'
          >>> hex(-42)
          '-0x2a'

     Se si desidera convertire un numero intero in una stringa
     esadecimale maiuscola o minuscola con prefisso o meno, è possibile
     utilizzare uno dei seguenti modi:

          >>> '%#x' % 255, '%x' % 255, '%X' % 255
          ('0xff', 'ff', 'FF')
          >>> format(255, '#x'), format(255, 'x'), format(255, 'X')
          ('0xff', 'ff', 'FF')
          >>> f'{255:#x}', f'{255:x}', f'{255:X}'
          ('0xff', 'ff', 'FF')

     Vedi anche *note format(): 199. per maggiori informazioni.

     Vedi anche *note int(): 19b. per convertire una stringa esadecimale
     in un numero intero utilizzando una base di 16.

          Nota: Per ottenere una rappresentazione in stringa esadecimale
          di un float, utilizzare il metodo *note float.hex(): 20ec.

 -- Funzione: id (object, /)

     Restituisce «l’identità» di un oggetto.  Questo è un numero intero
     che è garantito essere unico e costante per questo oggetto durante
     la sua vita.  Due oggetti con vite non sovrapposte possono avere lo
     stesso valore di *note id(): 162a.

     Questo è l’indirizzo dell’oggetto in memoria.

     Solleva un *note evento di auditing: 1c56. ‘builtins.id’ con
     l’argomento ‘id’.

 -- Funzione: input ()

 -- Funzione: input (prompt, /)

     Se l’argomento 'prompt' è presente, viene scritto nello standard
     output senza un a capo finale.  La funzione legge quindi una riga
     dall’input, la converte in una stringa (eliminando il newline
     finale) e la restituisce.  Quando EOF viene letto, viene sollevata
     l’eccezione *note EOFError: 14e1.  Esempio:

          >>> s = input('--> ')
          --> Monty Python's Flying Circus
          >>> s
          "Monty Python's Flying Circus"

     Se il modulo *note readline: bf. è stato caricato, allora *note
     input(): 14e0. lo utilizzerà per fornire funzionalità di modifica
     elaborata delle righe e cronologia.

     Solleva un *note evento di auditing: 1c56. ‘builtins.input’ con
     l’argomento ‘prompt’ prima di leggere l’input.

     Solleva un *note evento di auditing: 1c56. ‘builtins.input/result’
     con il risultato dopo aver letto l’input con successo.

 -- Classe: int (number=0, /)

 -- Classe: int (string, /, base=10)

     Return an integer object constructed from a number or a string, or
     return ‘0’ if no arguments are given.

     Examples:

          >>> int(123.45)
          123
          >>> int('123')
          123
          >>> int('   -12_345\n')
          -12345
          >>> int('FACE', 16)
          64206
          >>> int('0xface', 0)
          64206
          >>> int('01110011', base=2)
          115

     If the argument defines *note __int__(): 19d, ‘int(x)’ returns
     ‘x.__int__()’.  If the argument defines *note __index__(): 19e, it
     returns ‘x.__index__()’.  For floating-point numbers, this
     truncates towards zero.

     If the argument is not a number or if 'base' is given, then it must
     be a string, *note bytes: 192, or *note bytearray: 344. instance
     representing an integer in radix 'base'.  Optionally, the string
     can be preceded by ‘+’ or ‘-’ (with no space in between), have
     leading zeros, be surrounded by whitespace, and have single
     underscores interspersed between digits.

     Una stringa intera in base-n contiene cifre, ciascuna
     rappresentante un valore da 0 a n-1.  I valori 0-9 possono essere
     rappresentati da qualsiasi cifra decimale Unicode.  I valori 10-35
     possono essere rappresentati da ‘a’ a ‘z’ (o ‘A’ a ‘Z’).  La base
     predefinita è 10.  Le basi consentite sono 0 e 2-36.  Le stringhe
     in base 2, 8 e 16 possono essere opzionalmente precedute dai
     prefissi ‘0b’/‘0B’, ‘0o’/‘0O’ o ‘0x’/‘0X’, come con i letterali
     interi nel codice.  Per la base 0, la stringa viene interpretata in
     modo simile a un *note letterale intero nel codice: 22f4, nel senso
     che la base effettiva è 2, 8, 10 o 16 come determinato dal
     prefisso.  La base 0 disabilita anche gli zeri iniziali:
     ‘int('010', 0)’ non è legale, mentre ‘int('010')’ e ‘int('010', 8)’
     lo sono.

     Il tipo di intero è descritto in *note Tipi Numerici — int, float,
     complex: 1fc4.

     Cambiato nella versione 3.4: Se 'base' non è un’istanza di *note
     int: 19b. e l’oggetto 'base' ha un metodo *note base.__index__:
     19e, quel metodo viene chiamato per ottenere un intero per la base.
     Le versioni precedenti usavano *note base.__int__: 19d. invece di
     *note base.__index__: 19e.

     Cambiato nella versione 3.6: È consentito raggruppare le cifre con
     trattini bassi come nei letterali di codice.

     Cambiato nella versione 3.7: The first parameter is now
     positional-only.

     Cambiato nella versione 3.8: Ritorna a *note __index__(): 19e. se
     *note __int__(): 19d. non è definito.

     Cambiato nella versione 3.11: *note int: 19b. string inputs and
     string representations can be limited to help avoid denial of
     service attacks.  A *note ValueError: 2ec. is raised when the limit
     is exceeded while converting a string to an *note int: 19b. or when
     converting an *note int: 19b. into a string would exceed the limit.
     See the *note integer string conversion length limitation: 80c.
     documentation.

     Cambiato nella versione 3.14: *note int(): 19b. no longer delegates
     to the *note __trunc__(): 19c. method.

 -- Funzione: isinstance (object, classinfo, /)

     Restituisce ‘True’ se l’argomento 'object' è un’istanza
     dell’argomento 'classinfo', o di una sua sottoclasse (diretta,
     indiretta o *note virtual: 13be.).  Se 'object' non è un oggetto di
     quel tipo, la funzione restituisce sempre ‘False’.  Se 'classinfo'
     è una tupla di oggetti di tipo (o ricorsivamente, altre tuple di
     questo tipo) o una *note Tipo Unione: 9c7. di più tipi, restituisce
     ‘True’ se 'object' è un’istanza di uno qualsiasi dei tipi.  Se
     'classinfo' non è un tipo o una tupla di tipi e tali tuple, viene
     sollevata un’eccezione *note TypeError: 198.  *note TypeError: 198.
     può non essere sollevata per un tipo non valido se un controllo
     precedente ha successo.

     Cambiato nella versione 3.10: 'classinfo' può essere una *note Tipo
     Unione: 9c7.

 -- Funzione: issubclass (class, classinfo, /)

     Restituisce ‘True’ se 'class' è una sottoclasse (diretta, indiretta
     o *note virtual: 13be.) di 'classinfo'.  Una classe è considerata
     una sottoclasse di se stessa.  'classinfo' può essere una tupla di
     oggetti di classe (o ricorsivamente, altre tuple di questo tipo) o
     una *note Tipo Unione: 9c7, nel qual caso restituisce ‘True’ se
     'class' è una sottoclasse di uno qualsiasi degli elementi in
     'classinfo'.  In ogni altro caso, viene sollevata un’eccezione
     *note TypeError: 198.

     Cambiato nella versione 3.10: 'classinfo' può essere una *note Tipo
     Unione: 9c7.

 -- Funzione: iter (iterable, /)

 -- Funzione: iter (callable, sentinel, /)

     Return an *note iterator: 4c9. object.  The first argument is
     interpreted very differently depending on the presence of the
     second argument.  Without a second argument, the single argument
     must be a collection object which supports the *note iterable:
     142f. protocol (the *note __iter__(): e6b. method), or it must
     support the sequence protocol (the *note __getitem__(): 588. method
     with integer arguments starting at ‘0’).  If it does not support
     either of those protocols, *note TypeError: 198. is raised.  If the
     second argument, 'sentinel', is given, then the first argument must
     be a callable object.  The iterator created in this case will call
     'callable' with no arguments for each call to its *note __next__():
     14d5. method; if the value returned is equal to 'sentinel', *note
     StopIteration: df7. will be raised, otherwise the value will be
     returned.

     Vedi anche *note Tipi di Iteratore: 25b3.

     Una applicazione utile della seconda forma di *note iter(): 9d9. è
     costruire un lettore di blocchi.  Ad esempio, leggere blocchi a
     larghezza fissa da un file di database binario fino a raggiungere
     la fine del file:

          from functools import partial
          with open('mydata.db', 'rb') as f:
              for block in iter(partial(f.read, 64), b''):
                  process_block(block)

 -- Funzione: len (object, /)

     Restituisce la lunghezza (il numero di elementi) di un oggetto.
     L’argomento può essere una sequenza (come una stringa, bytes,
     tuple, list o range) o una collezione (come un dizionario, set o
     frozenset).

     ‘len’ solleva *note OverflowError: a83. su lunghezze maggiori di
     *note sys.maxsize: 13cd, come *note range(2 ** 100): b3f.

 -- Classe: list (iterable=(), /)

     Piuttosto che essere una funzione, *note list: 24d. è
     effettivamente un tipo di sequenza mutabile, come documentato in
     *note Liste: 200c. e *note Tipi di Sequenza — list, tuple, range:
     2018.

 -- Funzione: locals ()

     Restituisce un oggetto di mapping che rappresenta la tabella dei
     simboli locali corrente, con i nomi delle variabili come chiavi e i
     riferimenti attualmente associati come valori.

     A livello di modulo, così come quando si usa *note exec(): 4a3. o
     *note eval(): 4a4. con uno spazio dei nomi singolo, questa funzione
     restituisce lo stesso spazio dei nomi di *note globals(): 1bf2.

     A livello di classe, restituisce lo spazio dei nomi che sarà
     passato al costruttore della metaclasse.

     Quando si usa ‘exec()’ o ‘eval()’ con argomenti locali e globali
     separati, restituisce lo spazio dei nomi locale passato alla
     chiamata della funzione.

     In tutti i casi sopra menzionati, ogni chiamata a ‘locals()’ in un
     determinato frame di esecuzione restituirà lo 'stesso' oggetto di
     mapping.  Le modifiche apportate tramite l’oggetto di mapping
     restituito da ‘locals()’ saranno visibili come variabili locali
     assegnate, riassegnate o eliminate, e assegnare, riassegnare o
     eliminare variabili locali influenzerà immediatamente il contenuto
     dell’oggetto di mapping restituito.

     In un *note optimized scope: 4a2. (inclusi funzioni, generatori e
     coroutine), ogni chiamata a ‘locals()’ restituisce invece un
     dizionario nuovo contenente i binding correnti delle variabili
     locali della funzione e qualsiasi riferimento a celle non locali.
     In questo caso, le modifiche ai binding dei nomi apportate tramite
     il dizionario restituito non vengono scritte nuovamente nelle
     corrispondenti variabili locali o nei riferimenti a celle non
     locali, e assegnare, riassegnare o eliminare variabili locali e
     riferimenti a celle non locali non influisce sul contenuto dei
     dizionari precedentemente restituiti.

     Chiamare ‘locals()’ come parte di una comprensione in una funzione,
     generatore o coroutine equivale a chiamarlo nello scope contenente,
     eccetto che le variabili di iterazione inizializzate della
     comprensione saranno incluse.  In altri scope, si comporta come se
     la comprensione stesse eseguendo come una funzione annidata.

     Chiamare ‘locals()’ come parte di un’espressione del generatore
     equivale a chiamarlo in una funzione generatore annidata.

     Cambiato nella versione 3.12: Il comportamento di ‘locals()’ in una
     comprensione è stato aggiornato come descritto in PEP 709(2).

     Cambiato nella versione 3.13: Come parte di PEP 667(3), sono ora
     definiti i semantici della modifica degli oggetti mapping
     restituiti da questa funzione.  Il comportamento in *note ambiti
     ottimizzati: 4a2. è ora come descritto sopra.  A parte essere
     definiti, il comportamento in altri ambiti rimane invariato
     rispetto alle versioni precedenti.

 -- Funzione: map (function, iterable, /, *iterables, strict=False)

     Return an iterator that applies 'function' to every item of
     'iterable', yielding the results.  If additional 'iterables'
     arguments are passed, 'function' must take that many arguments and
     is applied to the items from all iterables in parallel.  With
     multiple iterables, the iterator stops when the shortest iterable
     is exhausted.  If 'strict' is ‘True’ and one of the iterables is
     exhausted before the others, a *note ValueError: 2ec. is raised.
     For cases where the function inputs are already arranged into
     argument tuples, see *note itertools.starmap(): 12ec.

     Cambiato nella versione 3.14: Added the 'strict' parameter.

 -- Funzione: max (iterable, /, *, key=None)

 -- Funzione: max (iterable, /, *, default, key=None)

 -- Funzione: max (arg1, arg2, /, *args, key=None)

     Restituisce l’elemento più grande in un iterabile o il più grande
     tra due o più argomenti.

     Se viene fornito un solo argomento posizionale, dovrebbe essere un
     *note iterable: 142f.  Viene restituito l’elemento più grande
     dell’iterabile.  Se vengono forniti due o più argomenti
     posizionali, viene restituito il più grande degli argomenti
     posizionali.

     Ci sono due argomenti opzionali solo per parole chiave.
     L’argomento 'key' specifica una funzione di ordinamento a un
     argomento, come quella utilizzata per *note list.sort(): dca.
     L’argomento 'default' specifica un oggetto da restituire se
     l’iterabile fornito è vuoto.  Se l’iterabile è vuoto e 'default'
     non è fornito, viene sollevata una *note ValueError: 2ec.

     Se ci sono più elementi massimali, la funzione restituisce il primo
     che incontra.  Questo è coerente con altri strumenti che preservano
     la stabilità dell’ordinamento come ‘sorted(iterable, key=keyfunc,
     reverse=True)[0]’ e ‘heapq.nlargest(1, iterable, key=keyfunc)’.

     Cambiato nella versione 3.4: Aggiunto il parametro 'default' solo
     per parole chiave.

     Cambiato nella versione 3.8: L’argomento 'key' può essere ‘None’.

 -- Classe: memoryview (object)

     Restituisce un oggetto «memory view» creato dall’argomento fornito.
     Vedi *note Memory Views: 25b4. per ulteriori informazioni.

 -- Funzione: min (iterable, /, *, key=None)

 -- Funzione: min (iterable, /, *, default, key=None)

 -- Funzione: min (arg1, arg2, /, *args, key=None)

     Restituisce l’elemento più piccolo in un iterabile o il più piccolo
     tra due o più argomenti.

     Se viene fornito un solo argomento posizionale, dovrebbe essere un
     *note iterable: 142f.  Viene restituito l’elemento più piccolo
     dell’iterabile.  Se vengono forniti due o più argomenti
     posizionali, viene restituito il più piccolo degli argomenti
     posizionali.

     Ci sono due argomenti opzionali solo per parole chiave.
     L’argomento 'key' specifica una funzione di ordinamento a un
     argomento, come quella utilizzata per *note list.sort(): dca.
     L’argomento 'default' specifica un oggetto da restituire se
     l’iterabile fornito è vuoto.  Se l’iterabile è vuoto e 'default'
     non è fornito, viene sollevata una *note ValueError: 2ec.

     Se ci sono più elementi minimi, la funzione restituisce il primo
     che incontra.  Questo è coerente con altri strumenti che preservano
     la stabilità dell’ordinamento come ‘sorted(iterable,
     key=keyfunc)[0]’ e ‘heapq.nsmallest(1, iterable, key=keyfunc)’.

     Cambiato nella versione 3.4: Aggiunto il parametro 'default' solo
     per parole chiave.

     Cambiato nella versione 3.8: L’argomento 'key' può essere ‘None’.

 -- Funzione: next (iterator, /)

 -- Funzione: next (iterator, default, /)

     Recupera l’elemento successivo dall”*note iterator: 4c9. chiamando
     il suo metodo *note __next__(): 14d5.  Se viene fornito 'default',
     esso viene restituito se l’iteratore è esaurito, altrimenti viene
     sollevata l’eccezione *note StopIteration: df7.

 -- Classe: object

     This is the ultimate base class of all other classes.  It has
     methods that are common to all instances of Python classes.  When
     the constructor is called, it returns a new featureless object.
     The constructor does not accept any arguments.

          Nota: *note object: c80. instances do 'not' have *note
          __dict__: 77e. attributes, so you can’t assign arbitrary
          attributes to an instance of *note object: c80.

 -- Funzione: oct (integer, /)

     Convert an integer number to an octal string prefixed with «0o».
     The result is a valid Python expression.  If 'integer' is not a
     Python *note int: 19b. object, it has to define an *note
     __index__(): 19e. method that returns an integer.  For example:

          >>> oct(8)
          '0o10'
          >>> oct(-56)
          '-0o70'

     Se vuoi convertire un numero intero in una stringa ottale con o
     senza il prefisso «0o», puoi usare uno dei seguenti modi.

          >>> '%#o' % 10, '%o' % 10
          ('0o12', '12')
          >>> format(10, '#o'), format(10, 'o')
          ('0o12', '12')
          >>> f'{10:#o}', f'{10:o}'
          ('0o12', '12')

     Vedi anche *note format(): 199. per maggiori informazioni.

 -- Funzione: open (file, mode='r', buffering=-1, encoding=None,
          errors=None, newline=None, closefd=True, opener=None)

     Apre 'file' e restituisce un corrispondente *note file object:
     13cb.  Se il file non può essere aperto, viene sollevata
     un’eccezione *note OSError: 2c0.  Vedi *note Lettura e Scrittura di
     File: 2050. per ulteriori esempi su come utilizzare questa
     funzione.

     'file' è un *note path-like object: 5a1. che fornisce il percorso
     (assoluto o relativo alla directory di lavoro corrente) del file da
     aprire o un descrittore del file intero del file da incapsulare.
     (Se viene fornito un file descriptor, esso viene chiuso quando
     l’oggetto I/O restituito viene chiuso, a meno che 'closefd' non sia
     impostato su ‘False’.)

     'mode' is an optional string that specifies the mode in which the
     file is opened.  It defaults to ‘'r'’ which means open for reading
     in text mode.  Other common values are ‘'w'’ for writing
     (truncating the file if it already exists), ‘'x'’ for exclusive
     creation, and ‘'a'’ for appending (which on 'some' Unix systems,
     means that 'all' writes append to the end of the file regardless of
     the current seek position).  In text mode, if 'encoding' is not
     specified the encoding used is platform-dependent: *note
     locale.getencoding(): 329. is called to get the current locale
     encoding.  (For reading and writing raw bytes use binary mode and
     leave 'encoding' unspecified.)  The available modes are:

     Carattere     Significato
                   
     ----------------------------------------------------------------------------------
                   
     ‘'r'’         apri per lettura (predefinito)
                   
                   
     ‘'w'’         apri per scrittura, troncando prima il file
                   
                   
     ‘'x'’         apri per creazione esclusiva, fallendo se il file esiste già
                   
                   
     ‘'a'’         apri per scrittura, aggiungendo alla fine del file se esiste
                   
                   
     ‘'b'’         modalità binaria
                   
                   
     ‘'t'’         modalità testo (predefinito)
                   
                   
     ‘'+'’         apri per aggiornamento (lettura e scrittura)
                   

     Il modo predefinito è ‘'r'’ (aperto per la lettura di testo,
     sinonimo di ‘'rt'’).  I modi ‘'w+'’ e ‘'w+b'’ aprono il file e lo
     troncano.  I modi ‘'r+'’ e ‘'r+b'’ aprono il file senza
     troncamento.

     Come menzionato nella *note Overview: 25b6, Python distingue tra
     I/O binario e di testo.  I file aperti in modalità binaria (incluso
     ‘'b'’ nell’argomento 'mode') restituiscono il contenuto come
     oggetti *note bytes: 192. senza alcuna decodifica.  In modalità
     testo (la predefinita, o quando ‘'t'’ è incluso nell’argomento
     'mode'), il contenuto del file è restituito come *note str: 169,
     con i byte decodificati utilizzando una codifica dipendente dalla
     piattaforma o quella specificata dall’opzione 'encoding' se
     fornita.

          Nota: Python non dipende dalla nozione di file di testo del
          sistema operativo sottostante; tutta l’elaborazione è fatta da
          Python stesso e quindi è indipendente dalla piattaforma.

     'buffering' è un intero opzionale utilizzato per impostare la
     politica di buffering.  Passa 0 per disattivare il buffering
     (consentito solo in modalità binaria), 1 per selezionare il line
     buffering (utilizzabile solo durante la scrittura in modalità
     testo) e un intero > 1 per indicare la dimensione in byte di un
     buffer a dimensione fissa.  Nota che specificare una dimensione del
     buffer in questo modo si applica per I/O binario bufferizzato, ma
     ‘TextIOWrapper’ (cioè, i file aperti con ‘mode='r+'’) avrebbe un
     altro buffering.  Per disabilitare il buffering in ‘TextIOWrapper’,
     considera l’uso del flag ‘write_through’ per *note
     io.TextIOWrapper.reconfigure(): d42.  Quando non viene dato
     l’argomento 'buffering', la politica di buffering predefinita
     funziona come segue:

        * Binary files are buffered in fixed-size chunks; the size of
          the buffer is ‘max(min(blocksize, 8 MiB),
          DEFAULT_BUFFER_SIZE)’ when the device block size is available.
          On most systems, the buffer will typically be 128 kilobytes
          long.

        * I file di testo «interattivi» (file per cui *note isatty():
          2053. restituisce ‘True’) utilizzano il line buffering.  Altri
          file di testo utilizzano la politica descritta sopra per i
          file binari.

     'encoding' è il nome della codifica utilizzata per decodificare o
     codificare il file.  Questo dovrebbe essere usato solo in modalità
     testo.  La codifica predefinita dipende dalla piattaforma
     (qualsiasi cosa restituita da *note locale.getencoding(): 329.), ma
     qualsiasi *note text encoding: 25b7. supportato da Python può
     essere utilizzato.  Vedi il modulo *note codecs: 1c. per l’elenco
     delle codifiche supportate.

     'errors' è una stringa opzionale che specifica come devono essere
     gestiti gli errori di codifica e decodifica — questo non può essere
     usato in modalità binaria.  È disponibile una varietà di gestori di
     errore standard (elencati sotto *note Error Handlers: 1b57.), anche
     se qualsiasi nome di gestione degli errori registrato con *note
     codecs.register_error(): 16a2. è anche valido.  I nomi standard
     includono:

        * ‘'strict'’ per sollevare un’eccezione *note ValueError: 2ec.
          se c’è un errore di codifica.  Il valore predefinito di ‘None’
          ha lo stesso effetto.

        * ‘'ignore'’ ignora gli errori.  Nota che ignorare gli errori di
          codifica può portare a perdita di dati.

        * ‘'replace'’ fa sì che un marcatore di sostituzione (come
          ‘'?'’) venga inserito dove ci sono dati malformati.

        * ‘'surrogateescape'’ rappresenterà eventuali byte errati come
          unità di codice basso surrogate che vanno da U+DC80 a U+DCFF.
          Queste unità di codice surrogate verranno quindi trasformate
          di nuovo negli stessi byte quando il gestore di errori
          ‘surrogateescape’ è utilizzato durante la scrittura dei dati.
          Questo è utile per elaborare file in una codifica sconosciuta.

        * ‘'xmlcharrefreplace'’ è supportato solo durante la scrittura
          in un file.  I caratteri non supportati dalla codifica sono
          sostituiti con il riferimento ai caratteri XML appropriato
          ‘&#NNN;’.

        * ‘'backslashreplace'’ sostituisce i dati malformati con le
          sequenze di escape con barra rovesciata di Python.

        * ‘'namereplace'’ (anche questo supportato solo durante la
          scrittura) sostituisce i caratteri non supportati con le
          sequenze di escape ‘\N{...}’.

     'newline' determina come analizzare i caratteri di nuova riga dal
     flusso.  Può essere ‘None’, ‘''’, ‘'\n'’, ‘'\r'’ e ‘'\r\n'’.
     Funziona come segue:

        * Quando si legge l’input dal flusso, se 'newline' è ‘None’, è
          attivata la modalità di nuove righe universali.  Le righe
          nell’input possono terminare con ‘'\n'’, ‘'\r'’ o ‘'\r\n'’ e
          queste sono tradotte in ‘'\n'’ prima di essere restituite al
          chiamante.  Se è ‘''’, è attivata la modalità di nuove righe
          universali, ma le terminazioni di riga sono restituite al
          chiamante non tradotte.  Se ha uno degli altri valori legali,
          le righe di input sono terminate solo dalla stringa data e la
          terminazione della riga è restituita al chiamante non
          tradotta.

        * Quando si scrive l’output nel flusso, se 'newline' è ‘None’,
          qualsiasi carattere ‘'\n'’ scritto è tradotto nel separatore
          di linea predefinito del sistema, *note os.linesep: 25b8.  Se
          'newline' è ‘''’ o ‘'\n'’, non avviene alcuna traduzione.  Se
          'newline' è uno degli altri valori legali, qualsiasi carattere
          ‘'\n'’ scritto è tradotto nella stringa data.

     Se 'closefd' è ‘False’ e viene fornito un descrittore di file
     anziché un nome file, il descrittore di file sottostante verrà
     mantenuto aperto quando il file viene chiuso.  Se viene fornito un
     nome file, 'closefd' deve essere ‘True’ (predefinito); altrimenti
     verrà generato un errore.

     Un apri-file personalizzato può essere utilizzato passando un
     callable come 'opener'.  Il descrittore di file sottostante per
     l’oggetto file viene quindi ottenuto chiamando 'opener' con
     ('file', 'flags').  'opener' deve restituire un descrittore di file
     aperto (passando *note os.open: f94. come 'opener' si ottiene una
     funzionalità simile a quella di passare ‘None’).

     Il file appena creato è *note non-inheritable: 10fe.

     Il seguente esempio utilizza il parametro *note dir_fd: 12f2. della
     funzione *note os.open(): f94. per aprire un file rispetto a una
     determinata directory:

          >>> import os
          >>> dir_fd = os.open('somedir', os.O_RDONLY)
          >>> def opener(path, flags):
          ...     return os.open(path, flags, dir_fd=dir_fd)
          ...
          >>> with open('spamspam.txt', 'w', opener=opener) as f:
          ...     print('This will be written to somedir/spamspam.txt', file=f)
          ...
          >>> os.close(dir_fd)  # don't leak a file descriptor

     Il tipo di *note file object: 13cb. restituito dalla funzione *note
     open(): 316. dipende dalla modalità.  Quando *note open(): 316. è
     usato per aprire un file in modalità testo (‘'w'’, ‘'r'’, ‘'wt'’,
     ‘'rt'’, ecc.), restituisce una sottoclasse di *note io.TextIOBase:
     8a5. (specificamente *note io.TextIOWrapper: 9c0.).  Quando è usato
     per aprire un file in modalità binaria con buffering, la classe
     restituita è una sottoclasse di *note io.BufferedIOBase: 8a4.  La
     classe esatta varia: in modalità di lettura binaria, restituisce un
     *note io.BufferedReader: 1416.; in modalità di scrittura binaria e
     di aggiunta binaria, restituisce un *note io.BufferedWriter: 15b9,
     e in modalità di lettura/scrittura, restituisce un *note
     io.BufferedRandom: 15ba.  Quando il buffering è disabilitato, viene
     restituito il flusso raw, una sottoclasse di *note io.RawIOBase:
     12d8, *note io.FileIO: 1517.

     Vedi anche i moduli di gestione dei file, come *note fileinput: 5f,
     *note io: 83. (dove è dichiarato *note open(): 316.), *note os: a5,
     *note os.path: a6, *note tempfile: e6. e *note shutil: ca.

     Raises an *note auditing event: 1c56. ‘open’ with arguments ‘path’,
     ‘mode’, ‘flags’.

     Gli argomenti ‘mode’ e ‘flags’ potrebbero essere stati modificati o
     dedotti dalla chiamata originale.

     Cambiato nella versione 3.3:

        * È stato aggiunto il parametro 'opener'.

        * È stato aggiunto il modo ‘'x'’.

        * *note IOError: 1255. veniva sollevato in passato, ora è un
          alias di *note OSError: 2c0.

        * *note FileExistsError: 1222. viene ora sollevato se il file
          aperto in modalità di creazione esclusiva (‘'x'’) esiste già.

     Cambiato nella versione 3.4:

        * Il file ora è non ereditabile.

     Cambiato nella versione 3.5:

        * Se la chiamata di sistema viene interrotta e il gestore dei
          segnali non solleva un’eccezione, la funzione ora riprova la
          chiamata di sistema anziché sollevare un’eccezione *note
          InterruptedError: f8a. (vedi PEP 475(4) per la motivazione).

        * È stato aggiunto il gestore di errori ‘'namereplace'’.

     Cambiato nella versione 3.6:

        * È stato aggiunto il supporto per accettare oggetti che
          implementano *note os.PathLike: e4d.

        * Su Windows, l’apertura di un buffer di console può restituire
          una sottoclasse di *note io.RawIOBase: 12d8. diversa da *note
          io.FileIO: 1517.

     Cambiato nella versione 3.11: È stato rimosso il modo ‘'U'’.

 -- Funzione: ord (character, /)

     Return the ordinal value of a character.

     If the argument is a one-character string, return the Unicode code
     point of that character.  For example, ‘ord('a')’ returns the
     integer ‘97’ and ‘ord('€')’ (Euro sign) returns ‘8364’.  This is
     the inverse of *note chr(): 19d7.

     If the argument is a *note bytes: 192. or *note bytearray: 344.
     object of length 1, return its single byte value.  For example,
     ‘ord(b'a')’ returns the integer ‘97’.

 -- Funzione: pow (base, exp, mod=None)

     Restituisce 'base' elevato a 'exp'; se 'mod' è presente,
     restituisce 'base' elevato a 'exp', modulo 'mod' (calcolato più
     efficientemente di ‘pow(base, exp) % mod’).  La forma a due
     argomenti ‘pow(base, exp)’ è equivalente all’utilizzo
     dell’operatore di potenza: ‘base**exp’.

     When arguments are builtin numeric types with mixed operand types,
     the coercion rules for binary arithmetic operators apply.  For
     *note int: 19b. operands, the result has the same type as the
     operands (after coercion) unless the second argument is negative;
     in that case, all arguments are converted to float and a float
     result is delivered.  For example, ‘pow(10, 2)’ returns ‘100’, but
     ‘pow(10, -2)’ returns ‘0.01’.  For a negative base of type *note
     int: 19b. or *note float: 196. and a non-integral exponent, a
     complex result is delivered.  For example, ‘pow(-9, 0.5)’ returns a
     value close to ‘3j’.  Whereas, for a negative base of type *note
     int: 19b. or *note float: 196. with an integral exponent, a float
     result is delivered.  For example, ‘pow(-9, 2.0)’ returns ‘81.0’.

     Per gli operandi *note int: 19b. 'base' e 'exp', se 'mod' è
     presente, 'mod' deve essere anche di tipo intero e 'mod' deve
     essere diverso da zero.  Se 'mod' è presente e 'exp' è negativo,
     'base' deve essere relativamente primo a 'mod'.  In tal caso, viene
     restituito ‘pow(inv_base, -exp, mod)’, dove 'inv_base' è un inverso
     di 'base' modulo 'mod'.

     Ecco un esempio di calcolo di un inverso per ‘38’ modulo ‘97’:

          >>> pow(38, -1, mod=97)
          23
          >>> 23 * 38 % 97 == 1
          True

     Cambiato nella versione 3.8: Per gli operandi *note int: 19b, la
     forma a tre argomenti di ‘pow’ ora consente che il secondo
     argomento sia negativo, permettendo il calcolo degli inversi
     modulari.

     Cambiato nella versione 3.8: Consente argomenti di parola chiave.
     In passato, erano supportati solo argomenti posizionali.

 -- Funzione: print (*objects, sep=' ', end='\n', file=None,
          flush=False)

     Stampa 'objects' sul flusso di testo 'file', separati da 'sep' e
     seguiti da 'end'.  'sep', 'end', 'file' e 'flush', se presenti,
     devono essere dati come argomenti di parola chiave.

     Tutti gli argomenti non di parola chiave sono convertiti in
     stringhe come fa *note str(): 169. e scritti nel flusso, separati
     da 'sep' e seguiti da 'end'.  Sia 'sep' che 'end' devono essere
     stringhe; possono anche essere ‘None’, il che significa usare i
     valori predefiniti.  Se non vengono dati 'objects', *note print():
     1177. scriverà solo 'end'.

     L’argomento 'file' deve essere un oggetto con un metodo
     ‘write(string)’; se non è presente o è ‘None’, verrà utilizzato
     *note sys.stdout: ccf.  Poiché gli argomenti stampati sono
     convertiti in stringhe di testo, *note print(): 1177. non può
     essere utilizzato con oggetti file in modalità binaria.  Per
     questi, utilizzare ‘file.write(...)’ invece.

     Il buffering dell’output è di solito determinato da 'file'.
     Tuttavia, se 'flush' è vero, il flusso viene forzato a essere
     svuotato.

     Cambiato nella versione 3.3: Aggiunto il parametro di parola chiave
     'flush'.

 -- Classe: property (fget=None, fset=None, fdel=None, doc=None)

     Restituisce un attributo di proprietà.

     'fget' è una funzione per ottenere il valore di un attributo.
     'fset' è una funzione per impostare il valore di un attributo.
     'fdel' è una funzione per eliminare il valore di un attributo.  E
     'doc' crea una docstring per l’attributo.

     Un uso tipico è definire un attributo gestito ‘x’:

          class C:
              def __init__(self):
                  self._x = None

              def getx(self):
                  return self._x

              def setx(self, value):
                  self._x = value

              def delx(self):
                  del self._x

              x = property(getx, setx, delx, "I'm the 'x' property.")

     Se 'c' è un’istanza di 'C', ‘c.x’ invocherà il getter, ‘c.x =
     valore’ invocherà il setter, e ‘del c.x’ il deleter.

     Se fornito, 'doc' sarà la docstring dell’attributo property.
     Altrimenti, la property copierà la docstring di 'fget' (se esiste).
     Questo rende possibile creare facilmente proprietà di sola lettura
     usando *note property(): 4b4. come un *note decorator: 93b.:

          class Parrot:
              def __init__(self):
                  self._voltage = 100000

              @property
              def voltage(self):
                  """Get the current voltage."""
                  return self._voltage

     Il decoratore ‘@property’ trasforma il metodo ‘voltage()’ in un
     «getter» per un attributo di sola lettura con lo stesso nome, e
     imposta la docstring di 'voltage' a «Get the current voltage.»

      -- Funzione: @getter

      -- Funzione: @setter

      -- Funzione: @deleter

          Un oggetto property ha metodi ‘getter’, ‘setter’, e ‘deleter’
          utilizzabili come decoratori che creano una copia della
          property con la funzione di accesso corrispondente impostata
          sulla funzione decorata.  Questo è spiegato al meglio con un
          esempio:

               class C:
                   def __init__(self):
                       self._x = None

                   @property
                   def x(self):
                       """I'm the 'x' property."""
                       return self._x

                   @x.setter
                   def x(self, value):
                       self._x = value

                   @x.deleter
                   def x(self):
                       del self._x

          Questo codice è esattamente equivalente al primo esempio.
          Assicurati di dare alle funzioni aggiuntive lo stesso nome
          della proprietà originale (‘x’ in questo caso.)

          L’oggetto property restituito ha anche gli attributi ‘fget’,
          ‘fset’, e ‘fdel’ corrispondenti agli argomenti del
          costruttore.

     Cambiato nella versione 3.5: Le docstring degli oggetti property
     ora sono scrivibili.

      -- Attributo: __name__

          Attribute holding the name of the property.  The name of the
          property can be changed at runtime.

          Added in version 3.13.

 -- Classe: range (stop, /)

 -- Classe: range (start, stop, step=1, /)

     Piuttosto che essere una funzione, *note range: b3f. è in realtà un
     tipo di sequenza immutabile, come documentato in *note Intervalli:
     25b9. e *note Tipi di Sequenza — list, tuple, range: 2018.

 -- Funzione: repr (object, /)

     Restituisce una stringa contenente una rappresentazione stampabile
     di un oggetto.  Per molti tipi, questa funzione tenta di restituire
     una stringa che produrrebbe un oggetto con lo stesso valore quando
     passato a *note eval(): 4a4.; altrimenti, la rappresentazione è una
     stringa racchiusa tra parentesi angolari che contiene il nome del
     tipo dell’oggetto insieme a informazioni aggiuntive, spesso
     includendo il nome e l’indirizzo dell’oggetto.  Una classe può
     controllare ciò che questa funzione restituisce per le sue istanze
     definendo un metodo *note __repr__(): 830.  Se *note
     sys.displayhook(): 1726. non è accessibile, questa funzione
     genererà *note RuntimeError: 244.

     Questa classe ha una rappresentazione personalizzata che può essere
     valutata:

          class Person:
             def __init__(self, name, age):
                self.name = name
                self.age = age

             def __repr__(self):
                return f"Person('{self.name}', {self.age})"

 -- Funzione: reversed (object, /)

     Return a reverse *note iterator: 4c9.  The argument must be an
     object which has a *note __reversed__(): e88. method or supports
     the sequence protocol (the *note __len__(): 1777. method and the
     *note __getitem__(): 588. method with integer arguments starting at
     ‘0’).

 -- Funzione: round (number, ndigits=None)

     Restituisce 'number' arrotondato a 'ndigits' precisione dopo il
     punto decimale.  Se 'ndigits' è omesso o è ‘None’, restituisce
     l’intero più vicino al valore di input.

     Per i tipi built-in che supportano *note round(): 14e2, i valori
     sono arrotondati al multiplo più vicino di 10 elevato alla potenza
     con segno meno 'ndigits'; se due multipli sono ugualmente vicini,
     l’arrotondamento è fatto verso la scelta pari (così, per esempio,
     sia ‘round(0.5)’ che ‘round(-0.5)’ sono ‘0’, e ‘round(1.5)’ è ‘2’).
     Qualsiasi valore intero è valido per 'ndigits' (positivo, zero o
     negativo).  Il valore restituito è un intero se 'ndigits' è omesso
     o è ‘None’.  Altrimenti, il valore restituito ha lo stesso tipo di
     'number'.

     Per un oggetto Python generico ‘number’, ‘round’ delega a
     ‘number.__round__’.

          Nota: Il comportamento di *note round(): 14e2. per i float può
          essere sorprendente: per esempio, ‘round(2.675, 2)’ dà ‘2.67’
          invece del previsto ‘2.68’.  Questo non è un bug: è il
          risultato del fatto che la maggior parte delle frazioni
          decimali non può essere rappresentata esattamente come un
          float.  Vedi *note Floating-Point Arithmetic; Issues and
          Limitations: 20ea. per maggiori informazioni.

 -- Classe: set (iterable=(), /)

     Restituisce un nuovo oggetto *note set: 184, opzionalmente con
     elementi presi da 'iterable'.  ‘set’ è una classe built-in.  Vedi
     *note set: 184. e *note Tipi di Insiemi — set, frozenset: 201b. per
     la documentazione su questa classe.

     Per altri contenitori vedi le classi built-in *note frozenset: 7f3,
     *note list: 24d, *note tuple: 614, e *note dict: 183, così come il
     modulo *note collections: 1e.

 -- Funzione: setattr (object, name, value, /)

     Questo è il corrispettivo di *note getattr(): dcc.  Gli argomenti
     sono un oggetto, una stringa e un valore arbitrario.  La stringa
     può nominare un attributo esistente o un nuovo attributo.  La
     funzione assegna il valore all’attributo, a condizione che
     l’oggetto lo consenta.  Per esempio, ‘setattr(x, 'foobar', 123)’ è
     equivalente a ‘x.foobar = 123’.

     'name' non deve essere necessariamente un identificatore Python
     come definito in *note Names (identifiers and keywords): 2289. a
     meno che l’oggetto non scelga di far rispettare ciò, per esempio in
     un metodo personalizzato *note __getattribute__(): dcd. o tramite
     *note __slots__: 16f2.  Un attributo il cui nome non è un
     identificatore non sarà accessibile usando la notazione a punto, ma
     è accessibile tramite *note getattr(): dcc. ecc.

          Nota: Poiché *note nome privato confuso: 208d. avviene al
          momento della compilazione, bisogna manualmente confondere il
          nome di un attributo privato (attributi con due trattini bassi
          all’inizio) per impostarlo con *note setattr(): 259a.

 -- Classe: slice (stop, /)

 -- Classe: slice (start, stop, step=None, /)

     Restituisce un oggetto *note slice: 25ba. che rappresenta l’insieme
     di indici specificati da ‘range(start, stop, step)’.  Gli argomenti
     'start' e 'step' predefiniti sono ‘None’.

     Gli oggetti Slice hanno attributi dati di sola lettura ‘start’,
     ‘stop’, e ‘step’ che restituiscono semplicemente i valori degli
     argomenti (o il loro valore predefinito).  Non hanno altra
     funzionalità esplicita; tuttavia, sono usati da NumPy e da altri
     pacchetti di terze parti.

      -- Attributo: start

      -- Attributo: stop

      -- Attributo: step

     Gli oggetti Slice vengono anche generati quando viene utilizzata la
     sintassi di indicizzazione estesa.  Per esempio:
     ‘a[start:stop:step]’ o ‘a[start:stop, i]’.  Vedi *note
     itertools.islice(): d45. per una versione alternativa che
     restituisce un *note iterator: 4c9.

     Cambiato nella versione 3.12: Gli oggetti Slice ora sono *note
     hashable: 825. (fornito che *note start: 238b, *note stop: 238c, e
     *note step: 238d. siano hashable).

 -- Funzione: sorted (iterable, /, *, key=None, reverse=False)

     Restituisce una nuova lista ordinata dagli elementi in 'iterable'.

     Ha due argomenti opzionali che devono essere specificati come
     argomenti per parola chiave.

     'key' specifica una funzione di un argomento che viene utilizzata
     per estrarre una chiave di confronto da ciascun elemento in
     'iterable' (per esempio, ‘key=str.lower’).  Il valore predefinito è
     ‘None’ (confronta gli elementi direttamente).

     'reverse' è un valore booleano.  Se impostato su ‘True’, gli
     elementi della lista vengono ordinati come se ogni confronto fosse
     inverso.

     Usa *note functools.cmp_to_key(): 13e2. per convertire una vecchia
     funzione 'cmp' in una funzione 'key'.

     La funzione built-in *note sorted(): dc9. è garantita per essere
     stabile.  Un ordinamento è stabile se garantisce di non modificare
     l’ordine relativo degli elementi che confronta uguali — questo è
     utile per ordinare in più passaggi (per esempio, ordinare per
     reparto, poi per grado di stipendio).

     The sort algorithm uses only ‘<’ comparisons between items.  While
     defining an *note __lt__(): 14a8. method will suffice for sorting,
     PEP 8(5) recommends that all six *note rich comparisons: 24ac. be
     implemented.  This will help avoid bugs when using the same data
     with other ordering tools such as *note max(): 110e. that rely on a
     different underlying method.  Implementing all six comparisons also
     helps avoid confusion for mixed type comparisons which can call the
     reflected *note __gt__(): 1513. method.

     Per esempi di ordinamento e un breve tutorial sull’ordinamento,
     vedere *note Sorting Techniques: 25bb.

 -- Funzione: @staticmethod

     Trasforma un metodo in un metodo statico.

     Un metodo statico non riceve un argomento primo implicito.  Per
     dichiarare un metodo statico, usa questo idiom:

          class C:
              @staticmethod
              def f(arg1, arg2, argN): ...

     La forma ‘@staticmethod’ è un *note decorator: 93b. di funzione –
     vedere *note Function definitions: 2002. per dettagli.

     Un metodo statico può essere chiamato sia sulla classe (come
     ‘C.f()’) che su un’istanza (come ‘C().f()’).  Inoltre, il *note
     descriptor: 1869. del metodo statico è anche invocabile, quindi può
     essere utilizzato nella definizione della classe (come ‘f()’).

     I metodi statici in Python sono simili a quelli trovati in Java o
     C++.  Inoltre, vedere *note classmethod(): 48f. per una variante
     utile per creare costruttori di classe alternativi.

     Come tutti i decoratori, è anche possibile chiamare ‘staticmethod’
     come una funzione regolare e fare qualcosa con il suo risultato.
     Questo è necessario in alcuni casi in cui è necessario un
     riferimento a una funzione dal corpo di una classe e si desidera
     evitare la trasformazione automatica a metodo istanza.  Per questi
     casi, utilizza questo idiom:

          def regular_function():
              ...

          class C:
              method = staticmethod(regular_function)

     Per maggiori informazioni sui metodi statici, vedere *note The
     standard type hierarchy: 2318.

     Cambiato nella versione 3.10: Static methods now inherit the method
     attributes (*note __module__: 2331, *note __name__: 14dc, *note
     __qualname__: 2330, *note __doc__: 13e1. and *note __annotations__:
     13e0.), have a new ‘__wrapped__’ attribute, and are now callable as
     regular functions.

 -- Classe: str (*, encoding='utf-8', errors='strict')

 -- Classe: str (object)

 -- Classe: str (object, encoding, errors='strict')

 -- Classe: str (object, *, errors)

     Restituisce una versione *note str: 169. di 'object'.  Vedi *note
     str(): 169. per dettagli.

     ‘str’ è la *note class: 1ce5. stringa built-in.  Per informazioni
     generali sulle stringhe, vedere *note Tipo Sequenza di Testo — str:
     1fc9.

 -- Funzione: sum (iterable, /, start=0)

     Somma 'start' e gli elementi di un 'iterable' da sinistra a destra
     e restituisce il totale.  Gli elementi dell”'iterable' sono
     normalmente numeri, e il valore iniziale non può essere una
     stringa.

     For some use cases, there are good alternatives to *note sum():
     696.  The preferred, fast way to concatenate a sequence of strings
     is by calling ‘''.join(sequence)’.  To add floating-point values
     with extended precision, see *note math.fsum(): 15db.  To
     concatenate a series of iterables, consider using *note
     itertools.chain(): 25bc.

     Cambiato nella versione 3.8: Il parametro 'start' può essere
     specificato come argomento per parola chiave.

     Cambiato nella versione 3.12: La somma di float è passata a un
     algoritmo che offre maggiore precisione e migliore commutatività
     sulla maggior parte delle build.

     Cambiato nella versione 3.14: Added specialization for summation of
     complexes, using same algorithm as for summation of floats.

 -- Classe: super

 -- Classe: super (type, object_or_type=None, /)

     Restituisce un oggetto proxy che delega le chiamate ai metodi a una
     classe genitrice o sorella di 'type'.  Questo è utile per accedere
     a metodi ereditati che sono stati sovrascritti in una classe.

     L”'object_or_type' determina l’ordine di risoluzione del *note
     method resolution order: 25bd. da cercare.  La ricerca inizia dalla
     classe subito dopo 'type'.

     For example, if *note __mro__: 235e. of 'object_or_type' is ‘D -> B
     -> C -> A -> object’ and the value of 'type' is ‘B’, then *note
     super(): 1a6. searches ‘C -> A -> object’.

     The *note __mro__: 235e. attribute of the class corresponding to
     'object_or_type' lists the method resolution search order used by
     both *note getattr(): dcc. and *note super(): 1a6.  The attribute
     is dynamic and can change whenever the inheritance hierarchy is
     updated.

     Se il secondo argomento viene omesso, l’oggetto super restituito
     non è associato ad alcuna istanza.  Se il secondo argomento è un
     oggetto, ‘isinstance(obj, type)’ deve essere vero.  Se il secondo
     argomento è un tipo, ‘issubclass(type2, type)’ deve essere vero
     (questo è utile per i classmethods).

     Quando viene chiamato direttamente all’interno di un metodo
     ordinario di una classe, entrambi gli argomenti possono essere
     omessi («zero-argomento ‘super()’»).  In questo caso, 'type' sarà
     la classe contenitrice e 'obj' sarà il primo argomento della
     funzione immediatamente contenitrice (di solito ‘self’).  (Questo
     significa che ‘super()’ con zero argomenti non funzionerà come
     previsto all’interno di funzioni nidificate, inclusi gli
     espressioni generatore, che creano implicitamente funzioni
     nidificate).

     Ci sono due casi d’uso tipici per 'super'.  In una gerarchia di
     classi con ereditarietà singola, 'super' può essere usato per
     riferirsi alle classi genitori senza nominarle esplicitamente,
     rendendo così il codice più mantenibile.  Questo uso è molto simile
     all’uso di 'super' in altri linguaggi di programmazione.

     Il secondo caso d’uso è supportare l’ereditarietà multipla
     cooperativa in un ambiente di esecuzione dinamico.  Questo caso
     d’uso è unico per Python e non si trova nei linguaggi compilati
     staticamente o nei linguaggi che supportano solo l’ereditarietà
     singola.  Questo rende possibile implementare «diagrammi a
     diamante» dove più classi base implementano lo stesso metodo.  Un
     buon design richiede che tali implementazioni abbiano la stessa
     firma di chiamata in ogni caso (poiché l’ordine delle chiamate è
     determinato in fase di runtime, perché tale ordine si adatta ai
     cambiamenti nella gerarchia di classi e perché tale ordine può
     includere classi sorelle che sono sconosciute prima del runtime).

     Per entrambi i casi d’uso, una chiamata tipica alla superclass
     sembra così:

          class C(B):
              def method(self, arg):
                  super().method(arg)    # This does the same thing as:
                                         # super(C, self).method(arg)

     Oltre alla ricerca di metodi, *note super(): 1a6. funziona anche
     per la ricerca degli attributi.  Un possibile caso d’uso per questo
     è chiamare i *note descrittori: 1869. in una classe genitore o
     sorella.

     Nota che *note super(): 1a6. è implementato come parte del processo
     di associazione per le ricerche di attributi punteggiate esplicite
     come ‘super().__getitem__(name)’.  Lo fa implementando il proprio
     metodo *note __getattribute__(): dcd. per la ricerca di classi in
     un ordine prevedibile che supporta l’ereditarietà multipla
     cooperativa.  Di conseguenza, *note super(): 1a6. non è definito
     per le ricerche implicite utilizzando dichiarazioni o operatori
     come ‘super()[name]’.

     Nota anche che, a parte la forma con zero argomenti, *note super():
     1a6. non è limitato all’uso all’interno di metodi.  La forma a due
     argomenti specifica esattamente gli argomenti e fa i riferimenti
     appropriati.  La forma a zero argomenti funziona solo all’interno
     di una definizione di classe, poiché il compilatore riempie i
     dettagli necessari per recuperare correttamente la classe in fase
     di definizione, così come accedere all’istanza corrente per i
     metodi ordinari.

     Per suggerimenti pratici su come progettare classi cooperative
     usando *note super(): 1a6, vedi guida all'uso di super()(6).

     Cambiato nella versione 3.14: *note super: 1a6. objects are now
     *note pickleable: ab. and *note copyable: 29.

 -- Classe: tuple (iterable=(), /)

     Piuttosto che essere una funzione, *note tuple: 614. è
     effettivamente un tipo di sequenza immutabile, come documentato in
     *note Tuple: 2526. e *note Tipi di Sequenza — list, tuple, range:
     2018.

 -- Classe: type (object, /)

 -- Classe: type (name, bases, dict, /, **kwargs)

     With one argument, return the type of an 'object'.  The return
     value is a type object and generally the same object as returned by
     *note object.__class__: 16b4.

     La funzione incorporata *note isinstance(): 2ad. è raccomandata per
     testare il tipo di un oggetto, poiché prende in considerazione le
     sottoclassi.

     With three arguments, return a new type object.  This is
     essentially a dynamic form of the *note class: 14df. statement.
     The 'name' string is the class name and becomes the *note __name__:
     16b2. attribute.  The 'bases' tuple contains the base classes and
     becomes the *note __bases__: 16b3. attribute; if empty, *note
     object: c80, the ultimate base of all classes, is added.  The
     'dict' dictionary contains attribute and method definitions for the
     class body; it may be copied or wrapped before becoming the *note
     __dict__: e59. attribute.  The following two statements create
     identical ‘type’ objects:

          >>> class X:
          ...     a = 1
          ...
          >>> X = type('X', (), dict(a=1))

     See also:

        * *note Documentation on attributes and methods on classes:
          2357.

        * *note Oggetti Tipo: 25be.

     Gli argomenti di parole chiave forniti alla forma a tre argomenti
     sono passati alla macchina adeguata della metaclasse (di solito
     *note __init_subclass__(): 844.) allo stesso modo degli argomenti
     di parole chiave in una definizione di classe (a parte
     'metaclass').

     Vedi anche *note Customizing class creation: e47.

     Cambiato nella versione 3.6: Subclasses of ‘type’ which don’t
     override ‘type.__new__’ may no longer use the one-argument form to
     get the type of an object.

 -- Funzione: vars ()

 -- Funzione: vars (object, /)

     Return the *note __dict__: 77e. attribute for a module, class,
     instance, or any other object with a ‘__dict__’ attribute.

     Objects such as modules and instances have an updateable *note
     __dict__: 77e. attribute; however, other objects may have write
     restrictions on their ‘__dict__’ attributes (for example, classes
     use a *note types.MappingProxyType: 699. to prevent direct
     dictionary updates).

     Senza argomento, *note vars(): 1e0b. si comporta come *note
     locals(): 46f.

     Viene sollevata un’eccezione *note TypeError: 198. se viene
     specificato un oggetto ma non possiede un attributo *note __dict__:
     77e. (ad esempio, se la sua classe definisce l’attributo *note
     __slots__: 16f2.).

     Cambiato nella versione 3.13: Il risultato della chiamata a questa
     funzione senza argomento è stato aggiornato come descritto per il
     builtin *note locals(): 46f.

 -- Funzione: zip (*iterables, strict=False)

     Itera su più iterabili in parallelo, producendo tuple con un
     elemento da ciascun iterabile.

     Esempio:

          >>> for item in zip([1, 2, 3], ['sugar', 'spice', 'everything nice']):
          ...     print(item)
          ...
          (1, 'sugar')
          (2, 'spice')
          (3, 'everything nice')

     Più formalmente: *note zip(): 1a0. restituisce un iteratore di
     tuple, dove la 'i'-esima tupla contiene l”'i'-esimo elemento di
     ciascuno degli iterabili argomento.

     Un altro modo di pensare a *note zip(): 1a0. è che trasforma righe
     in colonne e colonne in righe.  Questo è simile a trasporre una
     matrice(7).

     *note zip(): 1a0. è pigro: gli elementi non saranno processati fino
     a quando l’iterabile non viene iterato, ad esempio, tramite un
     ciclo ‘for’ o avvolgendolo in una *note list: 24d.

     Una cosa da considerare è che gli iterabili passati a *note zip():
     1a0. potrebbero avere lunghezze diverse; a volte per progettazione
     e a volte a causa di un bug nel codice che ha preparato questi
     iterabili.  Python offre tre approcci diversi per affrontare questo
     problema:

        * Per impostazione predefinita, *note zip(): 1a0. si ferma
          quando l’iterabile più breve è esaurito.  Ignorerà gli
          elementi rimanenti negli iterabili più lunghi, tagliando il
          risultato alla lunghezza dell’iterabile più corto:

               >>> list(zip(range(3), ['fee', 'fi', 'fo', 'fum']))
               [(0, 'fee'), (1, 'fi'), (2, 'fo')]

        * *note zip(): 1a0. è spesso usato nei casi in cui si presume
          che gli iterabili abbiano la stessa lunghezza.  In tali casi,
          è raccomandato usare l’opzione ‘strict=True’.  Il suo output è
          lo stesso del normale *note zip(): 1a0.:

               >>> list(zip(('a', 'b', 'c'), (1, 2, 3), strict=True))
               [('a', 1), ('b', 2), ('c', 3)]

          A differenza del comportamento predefinito, solleva
          un’eccezione *note ValueError: 2ec. se un iterabile è esaurito
          prima degli altri:

               >>> for item in zip(range(3), ['fee', 'fi', 'fo', 'fum'], strict=True):
               ...     print(item)
               ...
               (0, 'fee')
               (1, 'fi')
               (2, 'fo')
               Traceback (most recent call last):
                 ...
               ValueError: zip() argument 2 is longer than argument 1

          Senza l’argomento ‘strict=True’, qualsiasi bug che risulti in
          iterabili di lunghezze diverse verrà silenziato, possibilmente
          manifestandosi come un bug difficile da trovare in un’altra
          parte del programma.

        * Gli iterabili più corti possono essere imbottiti con un valore
          costante per rendere tutti gli iterabili della stessa
          lunghezza.  Questo viene fatto da *note
          itertools.zip_longest(): 14a6.

     Casi limite: Con un singolo argomento iterabile, *note zip(): 1a0.
     restituisce un iteratore di 1-tuple.  Senza argomenti, restituisce
     un iteratore vuoto.

     Suggerimenti e trucchi:

        * L’ordine di valutazione da sinistra a destra degli iterabili è
          garantito.  Questo rende possibile un idioma per raggruppare
          una serie di dati in gruppi di lunghezza n usando
          ‘zip(*[iter(s)]*n, strict=True)’.  Questo ripete lo 'stesso'
          iteratore ‘n’ volte in modo che ogni tupla di output contenga
          il risultato di ‘n’ chiamate all’iteratore.  Questo ha
          l’effetto di dividere l’input in blocchi di lunghezza n.

        * *note zip(): 1a0. in combinazione con l’operatore ‘*’ può
          essere usato per separare una lista:

               >>> x = [1, 2, 3]
               >>> y = [4, 5, 6]
               >>> list(zip(x, y))
               [(1, 4), (2, 5), (3, 6)]
               >>> x2, y2 = zip(*zip(x, y))
               >>> x == list(x2) and y == list(y2)
               True

     Cambiato nella versione 3.10: Aggiunto l’argomento ‘strict’.

 -- Funzione: __import__ (name, globals=None, locals=None, fromlist=(),
          level=0)

          Nota: Questa è una funzione avanzata che non è necessaria
          nella programmazione Python quotidiana, a differenza di *note
          importlib.import_module(): 73d.

     Questa funzione è invocata dalla dichiarazione *note import: 7f9.
     Può essere sostituita (importando il modulo *note builtins: 13. e
     assegnando a ‘builtins.__import__’) al fine di cambiare la
     semantica della dichiarazione ‘import’, ma farlo è 'fortemente'
     sconsigliato poiché è di solito più semplice usare gli hook di
     importazione (vedi PEP 302(8)) per raggiungere gli stessi obiettivi
     e non causa problemi con il codice che assume che l’implementazione
     di importazione predefinita sia in uso.  L’uso diretto di *note
     __import__(): ad3. è anche sconsigliato a favore di *note
     importlib.import_module(): 73d.

     La funzione importa il modulo 'name', potenzialmente utilizzando i
     'globals' e 'locals' dati per determinare come interpretare il nome
     in un contesto di pacchetto.  La 'fromlist' fornisce i nomi degli
     oggetti o sottomoduli che dovrebbero essere importati dal modulo
     specificato da 'name'.  L’implementazione standard non utilizza
     affatto il suo argomento 'locals' e utilizza il suo argomento
     'globals' solo per determinare il contesto di pacchetto della
     dichiarazione *note import: 7f9.

     'level' specifica se usare importazioni assolute o relative.  ‘0’
     (il valore predefinito) significa eseguire solo importazioni
     assolute.  Valori positivi per 'level' indicano il numero di
     directory genitore da cercare relativi alla directory del modulo
     che chiama *note __import__(): ad3. (vedi PEP 328(9) per i
     dettagli).

     Quando la variabile 'name' è della forma ‘package.module’,
     normalmente viene restituito il pacchetto di livello superiore (il
     nome fino al primo punto), 'non' il modulo denominato 'name'.
     Tuttavia, quando viene fornito un argomento 'fromlist' non vuoto,
     viene restituito il modulo denominato 'name'.

     Ad esempio, la dichiarazione ‘import spam’ risulta in un bytecode
     simile al seguente codice:

          spam = __import__('spam', globals(), locals(), [], 0)

     La dichiarazione ‘import spam.ham’ risulta in questa chiamata:

          spam = __import__('spam.ham', globals(), locals(), [], 0)

     Nota come *note __import__(): ad3. restituisce qui il modulo di
     livello superiore perché questo è l’oggetto che viene associato a
     un nome dalla dichiarazione *note import: 7f9.

     D’altra parte, la dichiarazione ‘from spam.ham import eggs, sausage
     as saus’ risulta in

          _temp = __import__('spam.ham', globals(), locals(), ['eggs', 'sausage'], 0)
          eggs = _temp.eggs
          saus = _temp.sausage

     Qui, il modulo ‘spam.ham’ viene restituito da *note __import__():
     ad3.  Da questo oggetto, vengono recuperati i nomi da importare e
     assegnati ai loro rispettivi nomi.

     Se vuoi semplicemente importare un modulo (potenzialmente
     all’interno di un pacchetto) per nome, usa *note
     importlib.import_module(): 73d.

     Cambiato nella versione 3.3: I valori negativi per 'level' non sono
     più supportati (il che cambia anche il valore predefinito a 0).

     Cambiato nella versione 3.9: Quando vengono utilizzate le opzioni
     della linea di comando *note -E: b58. o *note -I: b59, la variabile
     d’ambiente *note PYTHONCASEOK: b57. viene ora ignorata.

   ---------- Footnotes ----------

   (1) Nota che il parser accetta solo la convenzione Unix per la fine
della riga.  Se stai leggendo il codice da un file, assicurati di usare
la modalità di conversione delle interruzioni di riga per convertire le
interruzioni di riga in stile Windows o Mac.

   (2) https://peps.python.org/pep-0709/

   (3) https://peps.python.org/pep-0667/

   (4) https://peps.python.org/pep-0475/

   (5) https://peps.python.org/pep-0008/

   (6) 
https://rhettinger.wordpress.com/2011/05/26/super-considered-super/

   (7) https://en.wikipedia.org/wiki/Transpose

   (8) https://peps.python.org/pep-0302/

   (9) https://peps.python.org/pep-0328/


File: python.info,  Node: Built-in Constants,  Next: Tipi incorporati,  Prev: Funzioni Incorporate,  Up: The Python Standard Library

5.3 Built-in Constants
======================

A small number of constants live in the built-in namespace.  They are:

 -- Dati: False

     The false value of the *note bool: 3c3. type.  Assignments to
     ‘False’ are illegal and raise a *note SyntaxError: 18e.

 -- Dati: True

     The true value of the *note bool: 3c3. type.  Assignments to ‘True’
     are illegal and raise a *note SyntaxError: 18e.

 -- Dati: None

     An object frequently used to represent the absence of a value, as
     when default arguments are not passed to a function.  Assignments
     to ‘None’ are illegal and raise a *note SyntaxError: 18e.  ‘None’
     is the sole instance of the *note NoneType: a54. type.

 -- Dati: NotImplemented

     A special value which should be returned by the binary special
     methods (e.g.  *note __eq__(): cf4, *note __lt__(): 14a8, *note
     __add__(): 23c3, *note __rsub__(): 23d3, etc.)  to indicate that
     the operation is not implemented with respect to the other type;
     may be returned by the in-place binary special methods (e.g.  *note
     __imul__(): 23c8, *note __iand__(): 23e2, etc.)  for the same
     purpose.  It should not be evaluated in a boolean context.
     ‘NotImplemented’ is the sole instance of the *note
     types.NotImplementedType: a55. type.

          Nota: When a binary (or in-place) method returns
          ‘NotImplemented’ the interpreter will try the reflected
          operation on the other type (or some other fallback, depending
          on the operator).  If all attempts return ‘NotImplemented’,
          the interpreter will raise an appropriate exception.
          Incorrectly returning ‘NotImplemented’ will result in a
          misleading error message or the ‘NotImplemented’ value being
          returned to Python code.

          See *note Implementing the arithmetic operations: 231b. for
          examples.

          Attenzione: ‘NotImplemented’ and ‘NotImplementedError’ are not
          interchangeable.  This constant should only be used as
          described above; see *note NotImplementedError: 36b. for
          details on correct usage of the exception.

     Cambiato nella versione 3.9: Evaluating ‘NotImplemented’ in a
     boolean context was deprecated.

     Cambiato nella versione 3.14: Evaluating ‘NotImplemented’ in a
     boolean context now raises a *note TypeError: 198.  It previously
     evaluated to *note True: e09. and emitted a *note
     DeprecationWarning: 1a3. since Python 3.9.

 -- Dati: Ellipsis

     The same as the ellipsis literal «‘...’», an object frequently used
     to indicate that something is omitted.  Assignment to ‘Ellipsis’ is
     possible, but assignment to ‘...’ raises a *note SyntaxError: 18e.
     ‘Ellipsis’ is the sole instance of the *note types.EllipsisType:
     a53. type.

 -- Dati: __debug__

     This constant is true if Python was not started with an *note -O:
     18c. option.  See also the *note assert: b62. statement.

     Nota: The names *note None: 886, *note False: d2d, *note True: e09.
     and *note __debug__: 9dc. cannot be reassigned (assignments to
     them, even as an attribute name, raise *note SyntaxError: 18e.), so
     they can be considered «true» constants.

* Menu:

* Constants added by the site module::


File: python.info,  Node: Constants added by the site module,  Up: Built-in Constants

5.3.1 Constants added by the ‘site’ module
------------------------------------------

The *note site: cc. module (which is imported automatically during
startup, except if the *note -S: 13b0. command-line option is given)
adds several constants to the built-in namespace.  They are useful for
the interactive interpreter shell and should not be used in programs.

 -- Dati: quit (code=None)
 -- Dati: exit (code=None)

     Objects that when printed, print a message like «Use quit() or
     Ctrl-D (i.e.  EOF) to exit», and when accessed directly in the
     interactive interpreter or called as functions, raise *note
     SystemExit: f3e. with the specified exit code.

 -- Dati: help

     Object that when printed, prints the message «Type help() for
     interactive help, or help(object) for help about object.», and when
     accessed directly in the interactive interpreter, invokes the
     built-in help system (see *note help(): ad6.).

 -- Dati: copyright
 -- Dati: credits

     Objects that when printed or called, print the text of copyright or
     credits, respectively.

 -- Dati: license

     Object that when printed, prints the message «Type license() to see
     the full license text», and when called, displays the full license
     text in a pager-like fashion (one screen at a time).


File: python.info,  Node: Tipi incorporati,  Next: Built-in Exceptions,  Prev: Built-in Constants,  Up: The Python Standard Library

5.4 Tipi incorporati
====================

Le sezioni seguenti descrivono i tipi standard incorporati
nell’interprete.

I principali tipi incorporati sono numerici, sequenze, mappature,
classi, istanze ed eccezioni.

Alcune classi di collezioni sono mutabili.  I metodi che aggiungono,
sottraggono o riorganizzano i loro membri in loco, e non restituiscono
un elemento specifico, non restituiscono mai l’istanza della collezione
stessa ma ‘None’.

Alcune operazioni sono supportate da diversi tipi di oggetti; in
particolare, praticamente tutti gli oggetti possono essere confrontati
per uguaglianza, testati per valore di verità e convertiti in una
stringa (con la funzione *note repr(): 1c1. o la funzione leggermente
diversa *note str(): 169.).  Quest’ultima funzione viene utilizzata
implicitamente quando un oggetto è scritto dalla funzione *note print():
1177.

* Menu:

* Test del Valore di Verità::
* Operazioni Booleane — and, or, not: Operazioni Booleane — and or not.
* Confronti::
* Tipi Numerici — int, float, complex: Tipi Numerici — int float complex.
* Tipo Booleano - bool::
* Tipi di Iteratore::
* Tipi di Sequenza — list, tuple, range: Tipi di Sequenza — list tuple range.
* Text and Binary Sequence Type Methods Summary::
* Tipo Sequenza di Testo — str::
* Tipi di sequenze binarie — bytes, bytearray, memoryview: Tipi di sequenze binarie — bytes bytearray memoryview.
* Tipi di Insiemi — set, frozenset: Tipi di Insiemi — set frozenset.
* Tipi di Mapping — dict::
* Tipi di gestori di contesti::
* Tipi di annotazione di tipo — Alias generico, Union: Tipi di annotazione di tipo — Alias generico Union.
* Altri Tipi Integrati::
* Attributi Speciali::
* Limitazione della lunghezza di conversione delle stringhe di interi::


File: python.info,  Node: Test del Valore di Verità,  Next: Operazioni Booleane — and or not,  Up: Tipi incorporati

5.4.1 Test del Valore di Verità
-------------------------------

Qualsiasi oggetto può essere testato per valore di verità, per essere
usato in una condizione *note if: 181. o *note while: 195b. o come
operando delle operazioni booleane sotto.

By default, an object is considered true unless its class defines either
a *note __bool__(): 14dd. method that returns ‘False’ or a *note
__len__(): 1777. method that returns zero, when called with the object.
(1)  If one of the methods raises an exception when called, the
exception is propagated and the object does not have a truth value (for
example, *note NotImplemented: 1a2.).  Here are most of the built-in
objects considered false:

   * costanti definite come false: ‘None’ e ‘False’

   * zero di qualsiasi tipo numerico: ‘0’, ‘0.0’, ‘0j’, ‘Decimal(0)’,
     ‘Fraction(0, 1)’

   * sequenze e collezioni vuote: ‘''’, ‘()’, ‘[]’, ‘{}’, ‘set()’,
     ‘range(0)’

Le operazioni e le funzioni incorporate che hanno un risultato booleano
restituiscono sempre ‘0’ o ‘False’ per false e ‘1’ o ‘True’ per true,
salvo diversa indicazione.  (Eccezione importante: le operazioni
booleane ‘or’ e ‘and’ restituiscono sempre uno dei loro operandi.)

   ---------- Footnotes ----------

   (1) Ulteriori informazioni su questi metodi speciali possono essere
trovate nel Manuale di Riferimento Python (*note Basic customization:
2393.).


File: python.info,  Node: Operazioni Booleane — and or not,  Next: Confronti,  Prev: Test del Valore di Verità,  Up: Tipi incorporati

5.4.2 Operazioni Booleane — ‘and’, ‘or’, ‘not’
----------------------------------------------

Queste sono le operazioni booleane, ordinate per priorità crescente:

Operazione        Risultato                             Note
                                                        
--------------------------------------------------------------------
                                                        
‘x or y’          se 'x' è vero, allora 'x',            (1)
                  altrimenti 'y'                        
                  
                                                        
‘x and y’         se 'x' è falso, allora 'x',           (2)
                  altrimenti 'y'                        
                  
                                                        
‘not x’           se 'x' è falso, allora ‘True’,        (3)
                  altrimenti ‘False’                    
                  

Note:

  1. Questo è un operatore a cortocircuito, quindi valuta il secondo
     argomento solo se il primo è falso.

  2. Questo è un operatore a cortocircuito, quindi valuta il secondo
     argomento solo se il primo è vero.

  3. ‘not’ ha una priorità inferiore rispetto agli operatori non
     booleani, quindi ‘not a == b’ è interpretato come ‘not (a == b)’, e
     ‘a == not b’ è un errore di sintassi.


File: python.info,  Node: Confronti,  Next: Tipi Numerici — int float complex,  Prev: Operazioni Booleane — and or not,  Up: Tipi incorporati

5.4.3 Confronti
---------------

Ci sono otto operazioni di confronto in Python.  Hanno tutte la stessa
priorità (che è superiore a quella delle operazioni booleane).  I
confronti possono essere concatenati arbitrariamente; per esempio, ‘x <
y <= z’ è equivalente a ‘x < y and y <= z’, tranne che 'y' è valutato
solo una volta (ma in entrambi i casi 'z' non è valutato affatto quando
‘x < y’ risulta falso).

Questa tabella riassume le operazioni di confronto:

Operazione       Significato
                 
-----------------------------------------------
                 
‘<’              strettamente minore di
                 
                 
‘<=’             minore o uguale
                 
                 
‘>’              strettamente maggiore di
                 
                 
‘>=’             maggiore o uguale
                 
                 
‘==’             uguale
                 
                 
‘!=’             diverso
                 
                 
‘is’             identità dell’oggetto
                 
                 
‘is not’         identità dell’oggetto
                 negata
                 

Unless stated otherwise, objects of different types never compare equal.
The ‘==’ operator is always defined but for some object types (for
example, class objects) is equivalent to *note is: 34c.  The ‘<’, ‘<=’,
‘>’ and ‘>=’ operators are only defined where they make sense; for
example, they raise a *note TypeError: 198. exception when one of the
arguments is a complex number.

Le istanze non identiche di una classe normalmente vengono considerate
come non uguali a meno che la classe definisca il metodo *note __eq__():
cf4.

Le istanze di una classe non possono essere ordinate rispetto ad altre
istanze della stessa classe, o di altri tipi di oggetti, a meno che la
classe non definisca abbastanza metodi *note __lt__(): 14a8, *note
__le__(): 1512, *note __gt__(): 1513, e *note __ge__(): 1514. (in
generale, *note __lt__(): 14a8. e *note __eq__(): cf4. sono sufficienti,
se si vogliono i significati convenzionali degli operatori di
confronto).

Il comportamento degli operatori *note is: 34c. e *note is not: 24b3.
non può essere personalizzato; inoltre possono essere applicati a
qualsiasi due oggetti e non sollevano mai un’eccezione.

Due operazioni con la stessa priorità sintattica, *note in: 34b. e *note
not in: 842, sono supportate da tipi che sono *note iterable: 142f. o
implementano il metodo *note __contains__(): 15c1.


File: python.info,  Node: Tipi Numerici — int float complex,  Next: Tipo Booleano - bool,  Prev: Confronti,  Up: Tipi incorporati

5.4.4 Tipi Numerici — ‘int’, ‘float’, ‘complex’
-----------------------------------------------

There are three distinct numeric types: 'integers', 'floating-point
numbers', and 'complex numbers'.  In addition, Booleans are a subtype of
integers.  Integers have unlimited precision.  Floating-point numbers
are usually implemented using double in C; information about the
precision and internal representation of floating-point numbers for the
machine on which your program is running is available in *note
sys.float_info: 1db7.  Complex numbers have a real and imaginary part,
which are each a floating-point number.  To extract these parts from a
complex number 'z', use ‘z.real’ and ‘z.imag’.  (The standard library
includes the additional numeric types *note fractions.Fraction: 213, for
rationals, and *note decimal.Decimal: 1fe, for floating-point numbers
with user-definable precision.)

Numbers are created by numeric literals or as the result of built-in
functions and operators.  Unadorned integer literals (including hex,
octal and binary numbers) yield integers.  Numeric literals containing a
decimal point or an exponent sign yield floating-point numbers.
Appending ‘'j'’ or ‘'J'’ to a numeric literal yields an imaginary number
(a complex number with a zero real part) which you can add to an integer
or float to get a complex number with real and imaginary parts.

I costruttori *note int(): 19b, *note float(): 196. e *note complex():
197. possono essere usati per produrre numeri di un tipo specifico.

Python fully supports mixed arithmetic: when a binary arithmetic
operator has operands of different numeric types, the operand with the
«narrower» type is widened to that of the other, where integer is
narrower than floating point.  Arithmetic with complex and real operands
is defined by the usual mathematical formula, for example:

     x + complex(u, v) = complex(x + u, v)
     x * complex(u, v) = complex(x * u, x * v)

A comparison between numbers of different types behaves as though the
exact values of those numbers were being compared.  (1)

Tutti i tipi numerici (eccetto i complessi) supportano le seguenti
operazioni (per le priorità delle operazioni, vedi *note Operator
precedence: 24c7.):

Operazione                Risultato                             Note          Documentazione
                                                                              completa
                                                                              
-------------------------------------------------------------------------------------------------------
                                                                              
‘x + y’                   somma di 'x' e 'y'
                          
                                                                              
‘x - y’                   differenza tra 'x' e 'y'
                          
                                                                              
‘x * y’                   prodotto di 'x' e 'y'
                          
                                                                              
‘x / y’                   quoziente di 'x' e 'y'
                          
                                                                              
‘x // y’                  quoziente di 'x' e 'y' arrotondato    (1)(2)
                          per difetto                           
                          
                                                                              
‘x % y’                   resto della divisione ‘x / y’         (2)
                                                                
                                                                              
‘-x’                      'x' negato
                          
                                                                              
‘+x’                      'x' invariato
                          
                                                                              
‘abs(x)’                  valore assoluto o magnitudine di                    *note abs(): 2077.
                          'x'                                                 
                          
                                                                              
‘int(x)’                  'x' convertito in intero              (3)(6)        *note int(): 19b.
                                                                              
                                                                              
‘float(x)’                'x' convertito in numero in virgola   (4)(6)        *note float(): 196.
                          mobile                                              
                          
                                                                              
‘complex(re, im)’         un numero complesso con parte reale   (6)           *note complex(): 197.
                          're' e parte immaginaria 'im'.                      
                          'im' predefinito a zero.
                          
                                                                              
‘c.conjugate()’           coniugato del numero complesso 'c'
                          
                                                                              
‘divmod(x, y)’            la coppia ‘(x // y, x % y)’           (2)           *note divmod(): b9b.
                                                                              
                                                                              
‘pow(x, y)’               'x' elevato alla potenza 'y'          (5)           *note pow(): 1a4.
                                                                              
                                                                              
‘x ** y’                  'x' elevato alla potenza 'y'          (5)
                                                                

Note:

  1. Anche chiamato divisione intera.  Per operandi di tipo *note int:
     19b, il risultato ha tipo *note int: 19b.  Per operandi di tipo
     *note float: 196, il risultato ha tipo *note float: 196.  In
     generale, il risultato è un numero intero, anche se il tipo del
     risultato non è necessariamente *note int: 19b.  Il risultato è
     sempre arrotondato verso meno infinito: ‘1//2’ è ‘0’, ‘(-1)//2’ è
     ‘-1’, ‘1//(-2)’ è ‘-1’, e ‘(-1)//(-2)’ è ‘0’.

  2. Non per numeri complessi.  Convertire invece a float usando *note
     abs(): 2077. se appropriato.

  3. 
     La conversione da *note float: 196. a *note int: 19b. tronca,
     scartando la parte frazionaria.  Vedere le funzioni *note
     math.floor(): 15c5. e *note math.ceil(): 15c6. per conversioni
     alternative.

  4. float accetta anche le stringhe «nan» e «inf» con un prefisso
     opzionale «+» o «-» per Not a Number (NaN) e infinito positivo o
     negativo.

  5. Python definisce ‘pow(0, 0)’ e ‘0 ** 0’ come ‘1’, come è comune nei
     linguaggi di programmazione.

  6. I letterali numerici accettati includono le cifre ‘0’ a ‘9’ o
     qualsiasi equivalente Unicode (punti di codice con la proprietà
     ‘Nd’).

     Vedere the Unicode Standard(2) per un elenco completo dei punti di
     codice con la proprietà ‘Nd’.

Tutti i tipi *note numbers.Real: 25d1. (*note int: 19b. e *note float:
196.) includono anche le seguenti operazioni:

Operazione               Risultato
                         
---------------------------------------------------------------------------
                         
*note math.trunc(x): 15c7.'x' troncato a *note Integral: 23ed.
                         
                         
*note round(x[, n]): 14e2.'x' arrotondato a 'n' cifre, arrotondando per
                         eccesso in caso di mezza unità.  Se 'n' è
                         omesso, il valore predefinito è 0.
                         
                         
*note math.floor(x): 15c5.il più grande *note Integral: 23ed. <= 'x'
                         
                         
*note math.ceil(x): 15c6.il più piccolo *note Integral: 23ed. >= 'x'
                         

Per ulteriori operazioni numeriche vedere i moduli *note math: 92. e
*note cmath: 19.

* Menu:

* Operazioni Bitwise sui Tipi Integer::
* Metodi Aggiuntivi sui Tipi Integer::
* Metodi aggiuntivi su Float::
* Additional Methods on Complex::
* Hashing dei tipi numerici::

   ---------- Footnotes ----------

   (1) Di conseguenza, l’elenco ‘[1, 2]’ è considerato uguale a ‘[1.0,
2.0]’, e analogamente per le tuple.

   (2) 
https://unicode.org/Public/UNIDATA/extracted/DerivedNumericType.txt


File: python.info,  Node: Operazioni Bitwise sui Tipi Integer,  Next: Metodi Aggiuntivi sui Tipi Integer,  Up: Tipi Numerici — int float complex

5.4.4.1 Operazioni Bitwise sui Tipi Integer
...........................................

Le operazioni bitwise hanno senso solo per gli interi.  Il risultato
delle operazioni bitwise è calcolato come se eseguito in complemento a
due con un numero infinito di bit di segno.

Le priorità delle operazioni binarie bitwise sono tutte inferiori alle
operazioni numeriche e superiori alle comparazioni; l’operazione unaria
‘~’ ha la stessa priorità delle altre operazioni numeriche unarie (‘+’ e
‘-’).

Questa tabella elenca le operazioni bitwise ordinate per priorità
crescente:

Operazione       Risultato                            Note
                                                      
---------------------------------------------------------------------
                                                      
‘x | y’          bitwise 'or' di 'x' e 'y'            (4)
                                                      
                                                      
‘x ^ y’          bitwise 'or esclusivo' di 'x' e      (4)
                 'y'                                  
                 
                                                      
‘x & y’          bitwise 'and' di 'x' e 'y'           (4)
                                                      
                                                      
‘x << n’         'x' spostato a sinistra di 'n' bit   (1)(2)
                                                      
                                                      
‘x >> n’         'x' spostato a destra di 'n' bit     (1)(3)
                                                      
                                                      
‘~x’             i bit di 'x' invertiti
                 

Note:

  1. I conteggi di shift negativi sono illegali e causano un’eccezione
     *note ValueError: 2ec.

  2. Uno shift a sinistra di 'n' bit è equivalente alla moltiplicazione
     per ‘pow(2, n)’.

  3. Uno shift a destra di 'n' bit è equivalente alla divisione intera
     per ‘pow(2, n)’.

  4. Eseguire questi calcoli con almeno un bit di estensione del segno
     in più in una rappresentazione a complemento a due finita (una
     larghezza di bit lavorativa di ‘1 + max(x.bit_length(),
     y.bit_length())’ o più) è sufficiente per ottenere lo stesso
     risultato come se ci fossero un numero infinito di bit di segno.


File: python.info,  Node: Metodi Aggiuntivi sui Tipi Integer,  Next: Metodi aggiuntivi su Float,  Prev: Operazioni Bitwise sui Tipi Integer,  Up: Tipi Numerici — int float complex

5.4.4.2 Metodi Aggiuntivi sui Tipi Integer
..........................................

Il tipo int implementa la *note numbers.Integral: 23ed. *note abstract
base class: 13be.  Inoltre, fornisce qualche metodo in più:

 -- Metodo: int.bit_length ()

     Restituisce il numero di bit necessari a rappresentare un intero in
     binario, escludendo il segno e gli zeri iniziali:

          >>> n = -37
          >>> bin(n)
          '-0b100101'
          >>> n.bit_length()
          6

     Più precisamente, se ‘x’ è diverso da zero, allora ‘x.bit_length()’
     è l’unico intero positivo ‘k’ tale che ‘2**(k-1) <= abs(x) < 2**k’.
     Equivalentemente, quando ‘abs(x)’ è sufficientemente piccolo da
     avere un logaritmo correttamente arrotondato, allora ‘k = 1 +
     int(log(abs(x), 2))’.  Se ‘x’ è zero, allora ‘x.bit_length()’
     restituisce ‘0’.

     Equivalente a:

          def bit_length(self):
              s = bin(self)       # binary representation:  bin(-37) --> '-0b100101'
              s = s.lstrip('-0b') # remove leading zeros and minus sign
              return len(s)       # len('100101') --> 6

     Added in version 3.1.

 -- Metodo: int.bit_count ()

     Restituisce il numero di uno nella rappresentazione binaria del
     valore assoluto dell’intero.  Questo è anche conosciuto come il
     conteggio della popolazione.  Esempio:

          >>> n = 19
          >>> bin(n)
          '0b10011'
          >>> n.bit_count()
          3
          >>> (-n).bit_count()
          3

     Equivalente a:

          def bit_count(self):
              return bin(self).count("1")

     Added in version 3.10.

 -- Metodo: int.to_bytes (length=1, byteorder='big', *, signed=False)

     Restituisce un array di byte che rappresenta un intero.

          >>> (1024).to_bytes(2, byteorder='big')
          b'\x04\x00'
          >>> (1024).to_bytes(10, byteorder='big')
          b'\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00'
          >>> (-1024).to_bytes(10, byteorder='big', signed=True)
          b'\xff\xff\xff\xff\xff\xff\xff\xff\xfc\x00'
          >>> x = 1000
          >>> x.to_bytes((x.bit_length() + 7) // 8, byteorder='little')
          b'\xe8\x03'

     L’intero è rappresentato utilizzando 'length' byte, e il valore
     predefinito è 1.  Viene sollevata un’eccezione *note OverflowError:
     a83. se l’intero non è rappresentabile con il numero di byte
     fornito.

     L’argomento 'byteorder' determina l’ordine dei byte utilizzato per
     rappresentare l’intero, e il valore predefinito è ‘"big"’.  Se
     'byteorder' è ‘"big"’, il byte più significativo è all’inizio
     dell’array di byte.  Se 'byteorder' è ‘"little"’, il byte più
     significativo è alla fine dell’array di byte.

     L’argomento 'signed' determina se viene utilizzato il complemento a
     due per rappresentare l’intero.  Se 'signed' è ‘False’ e viene
     fornito un intero negativo, viene sollevata un’eccezione *note
     OverflowError: a83.  Il valore predefinito di 'signed' è ‘False’.

     I valori predefiniti possono essere utilizzati per convertire
     comodamente un intero in un singolo oggetto byte:

          >>> (65).to_bytes()
          b'A'

     Tuttavia, quando si utilizzano gli argomenti predefiniti, non
     tentare di convertire un valore maggiore di 255 o si otterrà
     un’eccezione *note OverflowError: a83.

     Equivalente a:

          def to_bytes(n, length=1, byteorder='big', signed=False):
              if byteorder == 'little':
                  order = range(length)
              elif byteorder == 'big':
                  order = reversed(range(length))
              else:
                  raise ValueError("byteorder must be either 'little' or 'big'")

              return bytes((n >> i*8) & 0xff for i in order)

     Added in version 3.2.

     Cambiato nella versione 3.11: Aggiunti i valori predefiniti degli
     argomenti per ‘length’ e ‘byteorder’.

 -- Metodo: classmethod int.from_bytes (bytes, byteorder='big', *,
          signed=False)

     Restituisce l’intero rappresentato dall’array di byte fornito.

          >>> int.from_bytes(b'\x00\x10', byteorder='big')
          16
          >>> int.from_bytes(b'\x00\x10', byteorder='little')
          4096
          >>> int.from_bytes(b'\xfc\x00', byteorder='big', signed=True)
          -1024
          >>> int.from_bytes(b'\xfc\x00', byteorder='big', signed=False)
          64512
          >>> int.from_bytes([255, 0, 0], byteorder='big')
          16711680

     L’argomento 'bytes' deve essere un *note bytes-like object: 193. o
     un iterabile che produce byte.

     L’argomento 'byteorder' determina l’ordine dei byte utilizzato per
     rappresentare l’intero, e il valore predefinito è ‘"big"’.  Se
     'byteorder' è ‘"big"’, il byte più significativo è all’inizio
     dell’array di byte.  Se 'byteorder' è ‘"little"’, il byte più
     significativo è alla fine dell’array di byte.  Per richiedere
     l’ordine dei byte nativo del sistema host, utilizzare *note
     sys.byteorder: 25d6. come valore dell’ordine dei byte.

     L’argomento 'signed' indica se viene utilizzato il complemento a
     due per rappresentare l’intero.

     Equivalente a:

          def from_bytes(bytes, byteorder='big', signed=False):
              if byteorder == 'little':
                  little_ordered = list(bytes)
              elif byteorder == 'big':
                  little_ordered = list(reversed(bytes))
              else:
                  raise ValueError("byteorder must be either 'little' or 'big'")

              n = sum(b << i*8 for i, b in enumerate(little_ordered))
              if signed and little_ordered and (little_ordered[-1] & 0x80):
                  n -= 1 << 8*len(little_ordered)

              return n

     Added in version 3.2.

     Cambiato nella versione 3.11: Aggiunto valore predefinito per
     l’argomento ‘byteorder’.

 -- Metodo: int.as_integer_ratio ()

     Restituisce una coppia di interi il cui rapporto è uguale
     all’intero originale e ha un denominatore positivo.  Il rapporto di
     numeri interi (numeri interi) è sempre l’intero come numeratore e
     ‘1’ come denominatore.

     Added in version 3.8.

 -- Metodo: int.is_integer ()

     Restituisce ‘True’.  Esiste per compatibilità con il tipo
     anatropomorfico con *note float.is_integer(): 25d7.

     Added in version 3.12.


File: python.info,  Node: Metodi aggiuntivi su Float,  Next: Additional Methods on Complex,  Prev: Metodi Aggiuntivi sui Tipi Integer,  Up: Tipi Numerici — int float complex

5.4.4.3 Metodi aggiuntivi su Float
..................................

Il tipo float implementa la classe *note numbers.Real: 25d1. *note
abstract base class: 13be.  float ha anche i seguenti metodi aggiuntivi.

 -- Metodo: classmethod float.from_number (x)

     Class method to return a floating-point number constructed from a
     number 'x'.

     If the argument is an integer or a floating-point number, a
     floating-point number with the same value (within Python’s
     floating-point precision) is returned.  If the argument is outside
     the range of a Python float, an *note OverflowError: a83. will be
     raised.

     For a general Python object ‘x’, ‘float.from_number(x)’ delegates
     to ‘x.__float__()’.  If *note __float__(): bc3. is not defined then
     it falls back to *note __index__(): 19e.

     Added in version 3.14.

 -- Metodo: float.as_integer_ratio ()

     Restituisce una coppia di interi il cui rapporto è esattamente
     uguale al float originale.  Il rapporto è in termini minimi e ha un
     denominatore positivo.  Solleva *note OverflowError: a83. su
     infiniti e una *note ValueError: 2ec. su NaN.

 -- Metodo: float.is_integer ()

     Restituisce ‘True’ se l’istanza float è finita con valore intero, e
     ‘False’ altrimenti:

          >>> (-2.0).is_integer()
          True
          >>> (3.2).is_integer()
          False

Due metodi supportano la conversione da e verso stringhe esadecimali.
Poiché i float di Python sono memorizzati internamente come numeri
binari, la conversione di un float da o verso una stringa 'decimale' di
solito comporta un piccolo errore di arrotondamento.  Al contrario, le
stringhe esadecimali consentono una rappresentazione e specifica esatta
dei numeri in virgola mobile.  Questo può essere utile durante il
debugging e nel lavoro numerico.

 -- Metodo: float.hex ()

     Restituisce una rappresentazione di un numero in virgola mobile
     come una stringa esadecimale.  Per i numeri in virgola mobile
     finiti, questa rappresentazione includerà sempre un ‘0x’ iniziale e
     un ‘p’ finale con l’esponente.

 -- Metodo: classmethod float.fromhex (s)

     Metodo di classe per restituire il float rappresentato da una
     stringa esadecimale 's'.  La stringa 's' può avere spazi bianchi
     iniziali e finali.

Nota che *note float.hex(): 20ec. è un metodo di istanza, mentre *note
float.fromhex(): 25d9. è un metodo di classe.

Una stringa esadecimale prende la forma:

     [sign] ['0x'] integer ['.' fraction] ['p' exponent]

dove il ‘segno’ opzionale può essere ‘+’ o ‘-’, ‘intero’ e ‘frazione’
sono stringhe di cifre esadecimali, e l”‘esponente’ è un intero decimale
con un segno iniziale opzionale.  Il caso non è significativo, e ci deve
essere almeno una cifra esadecimale nell’intero o nella frazione.
Questa sintassi è simile a quella specificata nella sezione 6.4.4.2
dello standard C99, e anche a quella utilizzata in Java 1.5 in poi.  In
particolare, l’output di *note float.hex(): 20ec. può essere utilizzato
come letterale a virgola mobile esadecimale nel codice C o Java, e le
stringhe esadecimali prodotte dal carattere di formato ‘%a’ di C o da
‘Double.toHexString’ di Java sono accettate da *note float.fromhex():
25d9.

Nota che l’esponente è scritto in decimale piuttosto che in esadecimale,
e che fornisce la potenza di 2 con cui moltiplicare il coefficiente.  Ad
esempio, la stringa esadecimale ‘0x3.a7p10’ rappresenta il numero in
virgola mobile ‘(3 + 10./16 + 7./16**2) * 2.0**10’, o ‘3740.0’:

     >>> float.fromhex('0x3.a7p10')
     3740.0

Applicando la conversione inversa a ‘3740.0’ si ottiene una stringa
esadecimale diversa che rappresenta lo stesso numero:

     >>> float.hex(3740.0)
     '0x1.d380000000000p+11'


File: python.info,  Node: Additional Methods on Complex,  Next: Hashing dei tipi numerici,  Prev: Metodi aggiuntivi su Float,  Up: Tipi Numerici — int float complex

5.4.4.4 Additional Methods on Complex
.....................................

The ‘complex’ type implements the *note numbers.Complex: 25db. *note
abstract base class: 13be.  ‘complex’ also has the following additional
methods.

 -- Metodo: classmethod complex.from_number (x)

     Class method to convert a number to a complex number.

     For a general Python object ‘x’, ‘complex.from_number(x)’ delegates
     to ‘x.__complex__()’.  If *note __complex__(): 7fe. is not defined
     then it falls back to *note __float__(): bc3.  If ‘__float__()’ is
     not defined then it falls back to *note __index__(): 19e.

     Added in version 3.14.


File: python.info,  Node: Hashing dei tipi numerici,  Prev: Additional Methods on Complex,  Up: Tipi Numerici — int float complex

5.4.4.5 Hashing dei tipi numerici
.................................

Per i numeri ‘x’ e ‘y’, possibilmente di tipi diversi, è un requisito
che ‘hash(x) == hash(y)’ ogni volta che ‘x == y’ (vedi la documentazione
del metodo *note __hash__(): cf5. per ulteriori dettagli).  Per facilità
di implementazione e efficienza in una varietà di tipi numerici (inclusi
*note int: 19b, *note float: 196, *note decimal.Decimal: 1fe. e *note
fractions.Fraction: 213.) l’hash di Python per i tipi numerici si basa
su una singola funzione matematica definita per qualsiasi numero
razionale, e quindi si applica a tutte le istanze di *note int: 19b. e
*note fractions.Fraction: 213, e tutte le istanze finite di *note float:
196. e *note decimal.Decimal: 1fe.  Essenzialmente, questa funzione è
data dalla riduzione modulo ‘P’ per un primo fisso ‘P’.  Il valore di
‘P’ è reso disponibile a Python come l’attributo *note modulus: 25de. di
*note sys.hash_info: 1201.

Attualmente, il primo utilizzato è ‘P = 2**31 - 1’ su macchine con long
C a 32 bit e ‘P = 2**61 - 1’ su macchine con long C a 64 bit.

Ecco le regole in dettaglio:

   - Se ‘x = m / n’ è un numero razionale non negativo e ‘n’ non è
     divisibile per ‘P’, definire ‘hash(x)’ come ‘m * invmod(n, P) % P’,
     dove ‘invmod(n, P)’ fornisce l’inverso di ‘n’ modulo ‘P’.

   - Se ‘x = m / n’ è un numero razionale non negativo e ‘n’ è
     divisibile per ‘P’ (ma ‘m’ non lo è), allora ‘n’ non ha inverso
     modulo ‘P’ e la regola sopra non si applica; in questo caso,
     definire ‘hash(x)’ come il valore costante ‘sys.hash_info.inf’.

   - Se ‘x = m / n’ è un numero razionale negativo, definire ‘hash(x)’
     come ‘-hash(-x)’.  Se l’hash risultante è ‘-1’, sostituirlo con
     ‘-2’.

   - I valori particolari ‘sys.hash_info.inf’ e ‘-sys.hash_info.inf’
     sono utilizzati come valori hash per l’infinito positivo o negativo
     (rispettivamente).

   - Per un numero *note complex: 197. ‘z’, i valori hash delle parti
     reale e immaginaria sono combinati calcolando ‘hash(z.real) +
     sys.hash_info.imag * hash(z.imag)’, ridotto modulo
     ‘2**sys.hash_info.width’ in modo che rientri in
     ‘range(-2**(sys.hash_info.width - 1), 2**(sys.hash_info.width -
     1))’.  Ancora una volta, se il risultato è ‘-1’, viene sostituito
     con ‘-2’.

Per chiarire le regole sopra, ecco un esempio di codice Python,
equivalente all’hash integrato, per calcolare l’hash di un numero
razionale, *note float: 196. o *note complex: 197.:

     import sys, math

     def hash_fraction(m, n):
         """Compute the hash of a rational number m / n.

         Assumes m and n are integers, with n positive.
         Equivalent to hash(fractions.Fraction(m, n)).

         """
         P = sys.hash_info.modulus
         # Remove common factors of P.  (Unnecessary if m and n already coprime.)
         while m % P == n % P == 0:
             m, n = m // P, n // P

         if n % P == 0:
             hash_value = sys.hash_info.inf
         else:
             # Fermat's Little Theorem: pow(n, P-1, P) is 1, so
             # pow(n, P-2, P) gives the inverse of n modulo P.
             hash_value = (abs(m) % P) * pow(n, P - 2, P) % P
         if m < 0:
             hash_value = -hash_value
         if hash_value == -1:
             hash_value = -2
         return hash_value

     def hash_float(x):
         """Compute the hash of a float x."""

         if math.isnan(x):
             return object.__hash__(x)
         elif math.isinf(x):
             return sys.hash_info.inf if x > 0 else -sys.hash_info.inf
         else:
             return hash_fraction(*x.as_integer_ratio())

     def hash_complex(z):
         """Compute the hash of a complex number z."""

         hash_value = hash_float(z.real) + sys.hash_info.imag * hash_float(z.imag)
         # do a signed reduction modulo 2**sys.hash_info.width
         M = 2**(sys.hash_info.width - 1)
         hash_value = (hash_value & (M - 1)) - (hash_value & M)
         if hash_value == -1:
             hash_value = -2
         return hash_value


File: python.info,  Node: Tipo Booleano - bool,  Next: Tipi di Iteratore,  Prev: Tipi Numerici — int float complex,  Up: Tipi incorporati

5.4.5 Tipo Booleano - ‘bool’
----------------------------

I booleani rappresentano valori di verità.  Il tipo *note bool: 3c3. ha
esattamente due istanze costanti: ‘True’ e ‘False’.

La funzione integrata *note bool(): 3c3. converte qualsiasi valore in un
booleano, se il valore può essere interpretato come un valore di verità
(vedi la sezione *note Test del Valore di Verità: 1840. sopra).

Per le operazioni logiche, utilizzare gli *note operatori booleani:
25cc. ‘and’, ‘or’ e ‘not’.  Quando si applicano gli operatori bitwise
‘&’, ‘|’, ‘^’ a due booleani, restituiscono un booleano equivalente alle
operazioni logiche «and», «or», «xor».  Tuttavia, gli operatori logici
‘and’, ‘or’ e ‘!=’ dovrebbero essere preferiti a ‘&’, ‘|’ e ‘^’.

Deprecato dalla versione 3.12: The use of the bitwise inversion operator
‘~’ is deprecated and will raise an error in Python 3.16.

*note bool: 3c3. è una sottoclasse di *note int: 19b. (vedi *note Tipi
Numerici — int, float, complex: 1fc4.).  In molti contesti numerici,
‘False’ e ‘True’ si comportano come gli interi 0 e 1, rispettivamente.
Tuttavia, affidarsi a ciò è sconsigliato; convertire esplicitamente
utilizzando *note int(): 19b.


File: python.info,  Node: Tipi di Iteratore,  Next: Tipi di Sequenza — list tuple range,  Prev: Tipo Booleano - bool,  Up: Tipi incorporati

5.4.6 Tipi di Iteratore
-----------------------

Python supporta un concetto di iterazione sui contenitori.  Questo è
implementato utilizzando due metodi distinti; questi sono utilizzati per
consentire alle classi definite dall’utente di supportare l’iterazione.
Le sequenze, descritte più dettagliatamente di seguito, supportano
sempre i metodi di iterazione.

Un metodo deve essere definito per gli oggetti contenitore per fornire
il supporto *note iterable: 142f.:

 -- Metodo: container.__iter__ ()

     Restituisce un oggetto *note iterator: 4c9.  È richiesto che
     l’oggetto supporti il protocollo dell’iteratore descritto di
     seguito.  Se un contenitore supporta diversi tipi di iterazione,
     possono essere forniti ulteriori metodi per richiedere
     specificamente iteratori per quei tipi di iterazione.  (Un esempio
     di oggetto che supporta più forme di iterazione potrebbe essere una
     struttura ad albero che supporta sia l’attraversamento in ampiezza
     sia quello in profondità.)  Questo metodo corrisponde allo slot
     *note tp_iter: 16f6. della struttura dei tipi per oggetti Python
     nell’API Python/C.

Gli oggetti iteratore stessi devono supportare i seguenti due metodi,
che insieme formano il 'protocollo dell’iteratore':

 -- Metodo: iterator.__iter__ ()

     Restituisce l’oggetto *note iterator: 4c9. stesso.  Questo è
     richiesto per consentire sia ai contenitori che agli iteratori di
     essere utilizzati con le dichiarazioni *note for: 34a. e *note in:
     34b.  Questo metodo corrisponde allo slot *note tp_iter: 16f6.
     della struttura dei tipi per oggetti Python nell’API Python/C.

 -- Metodo: iterator.__next__ ()

     Restituisce il prossimo elemento dall”*note iterator: 4c9.  Se non
     ci sono ulteriori elementi, solleva l’eccezione *note
     StopIteration: df7.  Questo metodo corrisponde allo slot *note
     tp_iternext: 16f7. della struttura dei tipi per oggetti Python
     nell’API Python/C.

Python definisce diversi oggetti iteratore per supportare l’iterazione
su tipi di sequenze generali e specifici, dizionari e altre forme più
specializzate.  I tipi specifici non sono importanti oltre la loro
implementazione del protocollo dell’iteratore.

Una volta che il metodo *note __next__(): 14d5. di un iteratore solleva
*note StopIteration: df7, deve continuare a farlo nelle chiamate
successive.  Implementazioni che non rispettano questa proprietà sono
considerate difettose.

* Menu:

* Tipi di Generatore::


File: python.info,  Node: Tipi di Generatore,  Up: Tipi di Iteratore

5.4.6.1 Tipi di Generatore
..........................

Python’s *note generator: 1263.s provide a convenient way to implement
the iterator protocol.  If a container object’s *note __iter__(): e6b.
method is implemented as a generator, it will automatically return an
iterator object (technically, a generator object) supplying the *note
__iter__(): 2097. and *note __next__(): 2098. methods.  More information
about generators can be found in *note the documentation for the yield
expression: 2473.


File: python.info,  Node: Tipi di Sequenza — list tuple range,  Next: Text and Binary Sequence Type Methods Summary,  Prev: Tipi di Iteratore,  Up: Tipi incorporati

5.4.7 Tipi di Sequenza — ‘list’, ‘tuple’, ‘range’
-------------------------------------------------

Esistono tre tipi di sequenza fondamentali: liste, tuple e oggetti
range.  Ulteriori tipi di sequenza adatti per l’elaborazione di *note
dati binari: 25a0. e *note stringhe di testo: 1fc9. sono descritti in
sezioni dedicate.

* Menu:

* Operazioni Comuni sulle Sequenze::
* Tipi di Sequenza Immutabili::
* Tipi di Sequenza Mutabili::
* Liste: Liste<2>.
* Tuple::
* Intervalli::


File: python.info,  Node: Operazioni Comuni sulle Sequenze,  Next: Tipi di Sequenza Immutabili,  Up: Tipi di Sequenza — list tuple range

5.4.7.1 Operazioni Comuni sulle Sequenze
........................................

Le operazioni nella tabella seguente sono supportate dalla maggior parte
dei tipi di sequenza, sia mutabili che immutabili.  La ABC *note
collections.abc.Sequence: 13cc. è fornita per facilitare
l’implementazione corretta di queste operazioni su tipi di sequenza
personalizzati.

Questa tabella elenca le operazioni di sequenza ordinate in ordine
crescente di priorità.  Nella tabella, 's' e 't' sono sequenze dello
stesso tipo, 'n', 'i', 'j' e 'k' sono interi e 'x' è un oggetto
arbitrario che soddisfa eventuali restrizioni di tipo e valore imposte
da 's'.

Le operazioni ‘in’ e ‘not in’ hanno le stesse priorità delle operazioni
di confronto.  Le operazioni ‘+’ (concatenazione) e ‘*’ (ripetizione)
hanno la stessa priorità delle corrispondenti operazioni numeriche.  (1)

Operazione                     Risultato                            Note
                                                                    
-----------------------------------------------------------------------------------
                                                                    
‘x in s’                       ‘True’ se un elemento di 's' è       (1)
                               uguale a 'x', altrimenti ‘False’     
                               
                                                                    
‘x not in s’                   ‘False’ se un elemento di 's' è      (1)
                               uguale a 'x', altrimenti ‘True’      
                               
                                                                    
‘s + t’                        la concatenazione di 's' e 't'       (6)(7)
                                                                    
                                                                    
‘s * n’ o ‘n * s’              equivalente ad aggiungere 's' a se   (2)(7)
                               stesso 'n' volte                     
                               
                                                                    
‘s[i]’                         'i'-esimo elemento di 's', origine   (3)(8)
                               0                                    
                               
                                                                    
‘s[i:j]’                       fetta di 's' da 'i' a 'j'            (3)(4)
                                                                    
                                                                    
‘s[i:j:k]’                     fetta di 's' da 'i' a 'j' con        (3)(5)
                               passo 'k'                            
                               
                                                                    
‘len(s)’                       lunghezza di 's'
                               
                                                                    
‘min(s)’                       l’elemento più piccolo di 's'
                               
                                                                    
‘max(s)’                       l’elemento più grande di 's'
                               

Sequenze dello stesso tipo supportano anche confronti.  In particolare,
tuple e liste sono confrontate lessicograficamente confrontando gli
elementi corrispondenti.  Questo significa che per risultare uguali,
ogni elemento deve risultare uguale e le due sequenze devono essere
dello stesso tipo e avere la stessa lunghezza.  (Per i dettagli
completi, vedere *note Comparisons: 24ac. nella documentazione del
linguaggio.)

Gli iteratori avanti e indietro su sequenze mutabili accedono ai valori
usando un indice.  Questo indice continuerà ad avanzare (o retrocedere)
anche se la sequenza sottostante viene mutata.  L’iteratore termina solo
quando viene trovata un’eccezione *note IndexError: 173c. o *note
StopIteration: df7. (o quando l’indice scende sotto zero).

Note:

  1. Anche se le operazioni ‘in’ e ‘not in’ sono usate solo per testare
     la semplice appartenenza nel caso generale, alcune sequenze
     specializzate (come *note str: 169, *note bytes: 192. e *note
     bytearray: 344.) le usano anche per il test di sotto-sequenza:

          >>> "gg" in "eggs"
          True

  2. I valori di 'n' inferiori a ‘0’ sono trattati come ‘0’ (il che
     produce una sequenza vuota dello stesso tipo di 's').  Nota che gli
     elementi nella sequenza 's' non vengono copiati; sono referenziati
     più volte.  Questo spesso confonde i nuovi programmatori Python;
     considera:

          >>> lists = [[]] * 3
          >>> lists
          [[], [], []]
          >>> lists[0].append(3)
          >>> lists
          [[3], [3], [3]]

     Quello che è successo è che ‘[[]]’ è una lista a un solo elemento
     contenente una lista vuota, quindi tutti e tre gli elementi di
     ‘[[]] * 3’ sono riferimenti a questa singola lista vuota.
     Modificare uno qualsiasi degli elementi di ‘lists’ modifica questa
     singola lista.  Puoi creare una lista di liste diverse in questo
     modo:

          >>> lists = [[] for i in range(3)]
          >>> lists[0].append(3)
          >>> lists[1].append(5)
          >>> lists[2].append(7)
          >>> lists
          [[3], [5], [7]]

     Ulteriori spiegazioni sono disponibili nella voce delle FAQ *note
     How do I create a multidimensional list?: 25e7.

  3. Se 'i' o 'j' è negativo, l’indice è relativo alla fine della
     sequenza 's': viene sostituito da ‘len(s) + i’ o ‘len(s) + j’.  Ma
     nota che ‘-0’ è ancora ‘0’.

  4. The slice of 's' from 'i' to 'j' is defined as the sequence of
     items with index 'k' such that ‘i <= k < j’.

        * If 'i' is omitted or ‘None’, use ‘0’.

        * If 'j' is omitted or ‘None’, use ‘len(s)’.

        * If 'i' or 'j' is less than ‘-len(s)’, use ‘0’.

        * If 'i' or 'j' is greater than ‘len(s)’, use ‘len(s)’.

        * If 'i' is greater than or equal to 'j', the slice is empty.

  5. La fetta di 's' da 'i' a 'j' con passo 'k' è definita come la
     sequenza degli elementi con indice ‘x = i + n*k’ tale che ‘0 <= n <
     (j-i)/k’.  In altre parole, gli indici sono ‘i’, ‘i+k’, ‘i+2*k’,
     ‘i+3*k’ e così via, fermandosi quando si raggiunge 'j' (ma senza
     includere 'j').  Quando 'k' è positivo, 'i' e 'j' sono ridotti a
     ‘len(s)’ se sono maggiori.  Quando 'k' è negativo, 'i' e 'j' sono
     ridotti a ‘len(s) - 1’ se sono maggiori.  Se 'i' o 'j' sono omessi
     o ‘None’, diventano valori «finali» (quale finale dipende dal segno
     di 'k').  Nota, 'k' non può essere zero.  Se 'k' è ‘None’, viene
     trattato come ‘1’.

  6. La concatenazione di sequenze immutabili produce sempre un nuovo
     oggetto.  Questo significa che costruire una sequenza concatenando
     ripetutamente avrà un costo di runtime quadratico in relazione alla
     lunghezza totale della sequenza.  Per ottenere un costo di runtime
     lineare, è necessario passare a una delle alternative seguenti:

        * se stai concatenando oggetti *note str: 169, puoi costruire
          una lista e usare *note str.join(): 25e8. alla fine oppure
          scrivere a un’istanza di *note io.StringIO: 112b. e recuperare
          il suo valore al termine

        * se stai concatenando oggetti *note bytes: 192, puoi allo
          stesso modo usare *note bytes.join(): 25e9. o *note
          io.BytesIO: 10a6, oppure puoi fare una concatenazione in loco
          con un oggetto *note bytearray: 344.  Gli oggetti *note
          bytearray: 344. sono mutabili e hanno un meccanismo di
          sovra-allocazione efficiente

        * se concatenare oggetti *note tuple: 614, estendere una *note
          list: 24d. invece

        * per altri tipi, consultare la documentazione della classe
          pertinente

  7. Alcuni tipi di sequenze (come *note range: b3f.) supportano solo
     sequenze di elementi che seguono schemi specifici, e quindi non
     supportano la concatenazione o la ripetizione della sequenza.

  8. An *note IndexError: 173c. is raised if 'i' is outside the sequence
     range.

Sequence Methods
................

Sequence types also support the following methods:

 -- Metodo: sequence.count (value, /)

     Return the total number of occurrences of 'value' in 'sequence'.

 -- Metodo: sequence.index (value[, start[, stop])

     Return the index of the first occurrence of 'value' in 'sequence'.

     Raises *note ValueError: 2ec. if 'value' is not found in
     'sequence'.

     The 'start' or 'stop' arguments allow for efficient searching of
     subsections of the sequence, beginning at 'start' and ending at
     'stop'.  This is roughly equivalent to ‘start +
     sequence[start:stop].index(value)’, only without copying any data.

          Attenzione: Not all sequence types support passing the 'start'
          and 'stop' arguments.

   ---------- Footnotes ----------

   (1) Devono esserlo poiché il parser non può determinare il tipo degli
operandi.


File: python.info,  Node: Tipi di Sequenza Immutabili,  Next: Tipi di Sequenza Mutabili,  Prev: Operazioni Comuni sulle Sequenze,  Up: Tipi di Sequenza — list tuple range

5.4.7.2 Tipi di Sequenza Immutabili
...................................

L’unica operazione che i tipi di sequenza immutabili generalmente
implementano che non è implementata anche dai tipi di sequenza mutabili
è il supporto per la funzione built-in *note hash(): 802.

Questo supporto consente alle sequenze immutabili, come le istanze di
*note tuple: 614, di essere utilizzate come chiavi di *note dict: 183. e
memorizzate in istanze di *note set: 184. e *note frozenset: 7f3.

Tentare di fare l’hash di una sequenza immutabile che contiene valori
non hashabili risulterà in un *note TypeError: 198.


File: python.info,  Node: Tipi di Sequenza Mutabili,  Next: Liste<2>,  Prev: Tipi di Sequenza Immutabili,  Up: Tipi di Sequenza — list tuple range

5.4.7.3 Tipi di Sequenza Mutabili
.................................

Le operazioni nella tabella seguente sono definite sui tipi di sequenza
mutabili.  L’ABC *note collections.abc.MutableSequence: 4c0. è fornito
per rendere più facile implementare correttamente queste operazioni su
tipi di sequenza personalizzati.

Nella tabella, 's' è un’istanza di un tipo di sequenza mutabile, 't' è
un qualsiasi oggetto iterabile e 'x' è un oggetto arbitrario che
soddisfa qualsiasi restrizione di tipo e valore imposta da 's' (ad
esempio, *note bytearray: 344. accetta solo interi che soddisfano la
restrizione di valore ‘0 <= x <= 255’).

Operazione                         Risultato                            Note
                                                                        
--------------------------------------------------------------------------------------------------
                                                                        
‘s[i] = x’                         l’elemento 'i' di 's' è sostituito
                                   da 'x'
                                   
                                                                        
‘del s[i]’                         removes item 'i' of 's'
                                   
                                                                        
‘s[i:j] = t’                       il sottoinsieme di 's' da 'i' a
                                   'j' è sostituito dal contenuto
                                   dell’iterabile 't'
                                   
                                                                        
‘del s[i:j]’                       removes the elements of ‘s[i:j]’
                                   from the list (same as ‘s[i:j] =
                                   []’)
                                   
                                                                        
‘s[i:j:k] = t’                     gli elementi di ‘s[i:j:k]’ sono      (1)
                                   sostituiti da quelli di 't'          
                                   
                                                                        
‘del s[i:j:k]’                     rimuove gli elementi di ‘s[i:j:k]’
                                   dalla lista
                                   
                                                                        
‘s += t’                           estende 's' con il contenuto di
                                   't' (per lo più come
                                   ‘s[len(s):len(s)] = t’)
                                   
                                                                        
‘s *= n’                           aggiorna 's' con il suo contenuto    (2)
                                   ripetuto 'n' volte                   
                                   

Note:

  1. If 'k' is not equal to ‘1’, 't' must have the same length as the
     slice it is replacing.

  2. Il valore 'n' è un intero, o un oggetto che implementa *note
     __index__(): 19e.  Valori zero e negativi di 'n' svuotano la
     sequenza.  Gli elementi nella sequenza non sono copiati; sono
     referenziati più volte, come spiegato per ‘s * n’ sotto *note
     Operazioni Comuni sulle Sequenze: 25e6.

Mutable Sequence Methods
........................

Mutable sequence types also support the following methods:

 -- Metodo: sequence.append (value, /)

     Append 'value' to the end of the sequence This is equivalent to
     writing ‘seq[len(seq):len(seq)] = [value]’.

 -- Metodo: sequence.clear ()

     Added in version 3.3.

     Remove all items from 'sequence'.  This is equivalent to writing
     ‘del sequence[:]’.

 -- Metodo: sequence.copy ()

     Added in version 3.3.

     Create a shallow copy of 'sequence'.  This is equivalent to writing
     ‘sequence[:]’.

          Suggerimento: The ‘copy()’ method is not part of the *note
          MutableSequence: 4c0. *note ABC: 111c, but most concrete
          mutable sequence types provide it.

 -- Metodo: sequence.extend (iterable, /)

     Extend 'sequence' with the contents of 'iterable'.  For the most
     part, this is the same as writing ‘seq[len(seq):len(seq)] =
     iterable’.

 -- Metodo: sequence.insert (index, value, /)

     Insert 'value' into 'sequence' at the given 'index'.  This is
     equivalent to writing ‘sequence[index:index] = [value]’.

 -- Metodo: sequence.pop (index=-1, /)

     Retrieve the item at 'index' and also removes it from 'sequence'.
     By default, the last item in 'sequence' is removed and returned.

 -- Metodo: sequence.remove (value, /)

     Remove the first item from 'sequence' where ‘sequence[i] == value’.

     Raises *note ValueError: 2ec. if 'value' is not found in
     'sequence'.

 -- Metodo: sequence.reverse ()

     Reverse the items of 'sequence' in place.  This method maintains
     economy of space when reversing a large sequence.  To remind users
     that it operates by side-effect, it returns ‘None’.


File: python.info,  Node: Liste<2>,  Next: Tuple,  Prev: Tipi di Sequenza Mutabili,  Up: Tipi di Sequenza — list tuple range

5.4.7.4 Liste
.............

Le liste sono sequenze mutabili, tipicamente utilizzate per memorizzare
collezioni di elementi omogenei (dove il grado di somiglianza preciso
varia in base all’applicazione).

 -- Classe: list (iterable=(), /)

     Le liste possono essere costruite in diversi modi:

        * Usare una coppia di parentesi quadre per denotare la lista
          vuota: ‘[]’

        * Utilizzo delle parentesi quadre, separando gli elementi con
          virgole: ‘[a]’, ‘[a, b, c]’

        * Utilizzo di una lista comprensiva: ‘[x for x in iterable]’

        * Utilizzo del costruttore del tipo: ‘list()’ o ‘list(iterable)’

     Il costruttore costruisce una lista i cui elementi sono gli stessi
     e nello stesso ordine degli elementi di 'iterable'.  'iterable' può
     essere una sequenza, un contenitore che supporta l’iterazione, o un
     oggetto iteratore.  Se 'iterable' è già una lista, viene fatta una
     copia e restituita, simile a ‘iterable[:]’.  Ad esempio,
     ‘list('abc')’ restituisce ‘['a', 'b', 'c']’ e ‘list( (1, 2, 3) )’
     restituisce ‘[1, 2, 3]’.  Se non viene fornito alcun argomento, il
     costruttore crea una nuova lista vuota, ‘[]’.

     Molte altre operazioni producono anche liste, includendo la
     funzione built-in *note sorted(): dc9.

     Le liste implementano tutte le operazioni comuni di sequenza: *note
     common: 25e6. e modificabili: *note mutable: 259e.  Le liste
     forniscono anche il seguente metodo aggiuntivo:

      -- Metodo: sort (*, key=None, reverse=False)

          Questo metodo ordina la lista sul posto, utilizzando solo i
          confronti ‘<’ tra gli elementi.  Le eccezioni non vengono
          soppresse - se una qualsiasi operazione di confronto fallisce,
          l’intera operazione di ordinamento fallirà (e la lista sarà
          probabilmente lasciata in uno stato parzialmente modificato).

          *note sort(): dca. accetta due argomenti che possono essere
          passati solo tramite parola chiave (*note keyword-only
          arguments: 5a5.):

          'key' specifica una funzione di un argomento che viene
          utilizzata per estrarre una chiave di confronto da ciascun
          elemento della lista (ad esempio, ‘key=str.lower’).  La chiave
          corrispondente a ciascun elemento nella lista viene calcolata
          una volta e poi utilizzata per l’intero processo di
          ordinamento.  Il valore predefinito di ‘None’ significa che
          gli elementi della lista vengono ordinati direttamente senza
          calcolare un valore di chiave separato.

          L’utilità *note functools.cmp_to_key(): 13e2. è disponibile
          per convertire una funzione 'cmp' in stile 2.x in una funzione
          'key'.

          'reverse' è un valore booleano.  Se impostato su ‘True’, gli
          elementi della lista vengono ordinati come se ogni confronto
          fosse invertito.

          Questo metodo modifica la sequenza in loco per risparmiare
          spazio quando si ordina una grande sequenza.  Per ricordare
          agli utenti che funziona con effetti collaterali, non
          restituisce la sequenza ordinata (utilizzare *note sorted():
          dc9. per richiedere esplicitamente una nuova istanza di lista
          ordinata).

          Il metodo *note sort(): dca. è garantito per essere stabile.
          Un ordinamento è stabile se garantisce di non cambiare
          l’ordine relativo degli elementi che risultano uguali — questo
          è utile per l’ordinamento in più passate (ad esempio, ordinare
          per reparto, poi per grado salariale).

          Per esempi di ordinamento e un breve tutorial
          sull’ordinamento, vedere *note Sorting Techniques: 25bb.

          Mentre una lista viene ordinata, l’effetto di tentare di
          modificarla o anche solo ispezionarla è indefinito.
          L’implementazione C di Python fa apparire la lista vuota per
          la durata, e solleva *note ValueError: 2ec. se riesce a
          rilevare che la lista è stata modificata durante un
          ordinamento.

     Thread safety: Reading a single element from a *note list: 24d. is
     *note atomic: 25f3.:

          lst[i]   # list.__getitem__

     The following methods traverse the list and use *note atomic: 25f3.
     reads of each item to perform their function.  That means that they
     may return results affected by concurrent modifications:

          item in lst
          lst.index(item)
          lst.count(item)

     All of the above methods/operations are also lock-free.  They do
     not block concurrent modifications.  Other operations that hold a
     lock will not block these from observing intermediate states.

     All other operations from here on block using the per-object lock.

     Writing a single item via ‘lst[i] = x’ is safe to call from
     multiple threads and will not corrupt the list.

     The following operations return new objects and appear *note
     atomic: 25f3. to other threads:

          lst1 + lst2    # concatenates two lists into a new list
          x * lst        # repeats lst x times into a new list
          lst.copy()     # returns a shallow copy of the list

     Methods that only operate on a single elements with no shifting
     required are *note atomic: 25f3.:

          lst.append(x)  # append to the end of the list, no shifting required
          lst.pop()      # pop element from the end of the list, no shifting required

     The *note clear(): 603. method is also *note atomic: 25f3.  Other
     threads cannot observe elements being removed.

     The *note sort(): dca. method is not *note atomic: 25f3.  Other
     threads cannot observe intermediate states during sorting, but the
     list appears empty for the duration of the sort.

     The following operations may allow lock-free operations to observe
     intermediate states since they modify multiple elements in place:

          lst.insert(idx, item)  # shifts elements
          lst.pop(idx)           # idx not at the end of the list, shifts elements
          lst *= x               # copies elements in place

     The *note remove(): 1a43. method may allow concurrent modifications
     since element comparison may execute arbitrary Python code (via
     *note __eq__(): cf4.).

     *note extend(): 602. is safe to call from multiple threads.
     However, its guarantees depend on the iterable passed to it.  If it
     is a *note list: 24d, a *note tuple: 614, a *note set: 184, a *note
     frozenset: 7f3, a *note dict: 183. or a *note dictionary view
     object: 25f4. (but not their subclasses), the ‘extend’ operation is
     safe from concurrent modifications to the iterable.  Otherwise, an
     iterator is created which can be concurrently modified by another
     thread.  The same applies to inplace concatenation of a list with
     other iterables when using ‘lst += iterable’.

     Similarly, assigning to a list slice with ‘lst[i:j] = iterable’ is
     safe to call from multiple threads, but ‘iterable’ is only locked
     when it is also a *note list: 24d. (but not its subclasses).

     Operations that involve multiple accesses, as well as iteration,
     are never atomic.  For example:

          # NOT atomic: read-modify-write
          lst[i] = lst[i] + 1

          # NOT atomic: check-then-act
          if lst:
              item = lst.pop()

          # NOT thread-safe: iteration while modifying
          for item in lst:
              process(item)  # another thread may modify lst

     Consider external synchronization when sharing *note list: 24d.
     instances across threads.  See *note Python support for free
     threading: 25f5. for more information.


File: python.info,  Node: Tuple,  Next: Intervalli,  Prev: Liste<2>,  Up: Tipi di Sequenza — list tuple range

5.4.7.5 Tuple
.............

Le tuple sono sequenze immutabili, tipicamente utilizzate per
memorizzare collezioni di dati eterogenei (come le 2-tuple prodotte
dalla funzione built-in *note enumerate(): 1688.).  Le tuple sono
utilizzate anche nei casi in cui è necessaria una sequenza immutabile di
dati omogenei (come permettere la memorizzazione in un’istanza di *note
set: 184. o *note dict: 183.).

 -- Classe: tuple (iterable=(), /)

     Le tuple possono essere costruite in diversi modi:

        * Utilizzando una coppia di parentesi per denotare la tupla
          vuota: ‘()’

        * Utilizzando una virgola finale per una tupla singleton: ‘a,’ o
          ‘(a,)’

        * Separando gli elementi con virgole: ‘a, b, c’ o ‘(a, b, c)’

        * Utilizzando la funzione built-in *note tuple(): 614.:
          ‘tuple()’ o ‘tuple(iterable)’

     Il costruttore costruisce una tupla i cui elementi sono gli stessi
     e nello stesso ordine degli elementi di 'iterable'.  'iterable' può
     essere una sequenza, un contenitore che supporta l’iterazione, o un
     oggetto iteratore.  Se 'iterable' è già una tupla, viene restituita
     invariata.  Ad esempio, ‘tuple('abc')’ restituisce ‘('a', 'b',
     'c')’ e ‘tuple( [1, 2, 3] )’ restituisce ‘(1, 2, 3)’.  Se non viene
     fornito alcun argomento, il costruttore crea una nuova tupla vuota,
     ‘()’.

     Nota che in realtà è la virgola che crea una tupla, non le
     parentesi.  Le parentesi sono facoltative, tranne nel caso della
     tupla vuota, o quando sono necessarie per evitare ambiguità
     sintattiche.  Ad esempio, ‘f(a, b, c)’ è una chiamata a funzione
     con tre argomenti, mentre ‘f((a, b, c))’ è una chiamata a funzione
     con una 3-tuple come unico argomento.

     Le tuple implementano tutte le operazioni di sequenza comuni: *note
     common: 25e6.

Per collezioni eterogenee di dati dove l’accesso per nome è più chiaro
che l’accesso per indice, *note collections.namedtuple(): 4e1. può
essere una scelta più appropriata di un semplice oggetto tupla.


File: python.info,  Node: Intervalli,  Prev: Tuple,  Up: Tipi di Sequenza — list tuple range

5.4.7.6 Intervalli
..................

Il tipo *note range: b3f. rappresenta una sequenza immutabile di numeri
ed è comunemente utilizzato per iterare un numero specifico di volte nei
cicli *note for: 34a.

 -- Classe: range (stop, /)

 -- Classe: range (start, stop, step=1, /)

     Gli argomenti al costruttore di range devono essere interi (sia la
     classe built-in *note int: 19b. o qualsiasi oggetto che implementa
     il metodo speciale *note __index__(): 19e.).  Se l’argomento 'step'
     è omesso, il valore predefinito è ‘1’.  Se l’argomento 'start' è
     omesso, il valore predefinito è ‘0’.  Se 'step' è zero, viene
     sollevata l’eccezione *note ValueError: 2ec.

     Per un 'step' positivo, il contenuto di un intervallo ‘r’ è
     determinato dalla formula ‘r[i] = start + step*i’ dove ‘i >= 0’ e
     ‘r[i] < stop’.

     Per un 'step' negativo, il contenuto dell’intervallo è ancora
     determinato dalla formula ‘r[i] = start + step*i’, ma i vincoli
     sono ‘i >= 0’ e ‘r[i] > stop’.

     Un oggetto range sarà vuoto se ‘r[0]’ non soddisfa il vincolo di
     valore.  Gli intervalli supportano indici negativi, ma questi sono
     interpretati come indice dalla fine della sequenza determinata
     dagli indici positivi.

     Gli intervalli contenenti valori assoluti maggiori di *note
     sys.maxsize: 13cd. sono permessi, ma alcune funzionalità (come
     *note len(): 841.) potrebbero sollevare l’eccezione *note
     OverflowError: a83.

     Esempi di intervalli:

          >>> list(range(10))
          [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
          >>> list(range(1, 11))
          [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
          >>> list(range(0, 30, 5))
          [0, 5, 10, 15, 20, 25]
          >>> list(range(0, 10, 3))
          [0, 3, 6, 9]
          >>> list(range(0, -10, -1))
          [0, -1, -2, -3, -4, -5, -6, -7, -8, -9]
          >>> list(range(0))
          []
          >>> list(range(1, 0))
          []

     Gli intervalli implementano tutte le operazioni di sequenza comuni:
     *note common: 25e6, eccezion fatta per la concatenazione e la
     ripetizione (a causa del fatto che gli oggetti range possono
     rappresentare solo sequenze che seguono un modello rigoroso e la
     ripetizione e la concatenazione violerebbero di solito tale
     modello).

      -- Attributo: start

          Il valore del parametro 'start' (o ‘0’ se il parametro non è
          stato fornito)

      -- Attributo: stop

          Il valore del parametro 'stop'

      -- Attributo: step

          Il valore del parametro 'step' (o ‘1’ se il parametro non è
          stato fornito)

Il vantaggio del tipo *note range: b3f. rispetto a una lista regolare
*note list: 24d. o una tupla *note tuple: 614. è che un oggetto *note
range: b3f. utilizzerà sempre la stessa (piccola) quantità di memoria,
indipendentemente dalla dimensione dell’intervallo che rappresenta
(poiché memorizza solo i valori ‘start’, ‘stop’ e ‘step’, calcolando gli
elementi individuali e i sottointervalli secondo necessità).

Gli oggetti range implementano l’ABC *note collections.abc.Sequence:
13cc, e forniscono funzionalità come test di inclusione, ricerca
dell’indice degli elementi, slicing e supporto per indici negativi (vedi
*note Tipi di Sequenza — list, tuple, range: 2018.):

     >>> r = range(0, 20, 2)
     >>> r
     range(0, 20, 2)
     >>> 11 in r
     False
     >>> 10 in r
     True
     >>> r.index(10)
     5
     >>> r[5]
     10
     >>> r[:5]
     range(0, 10, 2)
     >>> r[-1]
     18

Testare gli oggetti range per uguaglianza con ‘==’ e ‘!=’ li confronta
come sequenze.  Cioè, due oggetti range sono considerati uguali se
rappresentano la stessa sequenza di valori.  (Nota che due oggetti range
che risultano uguali potrebbero avere attributi *note start: 25f8, *note
stop: 25f9. e *note step: 25fa. diversi, ad esempio ‘range(0) ==
range(2, 1, 3)’ oppure ‘range(0, 3, 2) == range(0, 4, 2)’.)

Cambiato nella versione 3.2: Implementare l’ABC Sequence.  Supporto per
slicing e indici negativi.  Testare gli oggetti *note int: 19b. per la
membership in tempo costante invece di iterare attraverso tutti gli
elementi.

Cambiato nella versione 3.3: Definire “==” e “!=” per confrontare gli
oggetti range basandosi sulla sequenza di valori che definiscono (invece
di confrontare basandosi sull’identità degli oggetti).

Aggiunti gli attributi *note start: 25f8, *note stop: 25f9. e *note
step: 25fa.

Vedi anche
..........

   * The linspace recipe(1) shows how to implement a lazy version of
     range suitable for floating-point applications.

   ---------- Footnotes ----------

   (1) 
https://code.activestate.com/recipes/579000-equally-spaced-numbers-linspace/


File: python.info,  Node: Text and Binary Sequence Type Methods Summary,  Next: Tipo Sequenza di Testo — str,  Prev: Tipi di Sequenza — list tuple range,  Up: Tipi incorporati

5.4.8 Text and Binary Sequence Type Methods Summary
---------------------------------------------------

The following table summarizes the text and binary sequence types
methods by category.

Category                       *note str: 169.                                             *note bytes: 192. and
                               methods                                                     *note bytearray: 344.
                                                                                           methods
                                                                                           
---------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                              
Formatting                     *note str.format(): 834.
                               
                                                                                                                         
*note str.format_map(): fd9.

*note f-strings: 19a.

*note Formattazione delle stringhe in stile printf: 8dc.        *note Formattazione Bytes stile printf: f83.
                                                                
                                                                                                                              
Searching and Replacing        *note str.find(): 10aa.*note str.rfind(): 10ab.             *note bytes.find(): 1bbc.*note bytes.rfind(): 1bbd.
                                                                                                                    
                                                                                                                         
*note str.index(): 19a4.       *note str.rindex(): 145f.        *note bytes.index(): 25fd. *note bytes.rindex(): 25fe.
                                                                                           
                                                                                                                         
*note str.startswith(): 10cd.                                   *note bytes.startswith(): 25ff.
                                                                
                                                                                                                         
*note str.endswith(): 10ce.                                     *note bytes.endswith(): 2600.
                                                                
                                                                                                                         
*note str.count(): 1969.                                        *note bytes.count(): 196a.
                                                                
                                                                                                                         
*note str.replace(): 4b9.                                       *note bytes.replace(): 2601.
                                                                
                                                                                                                              
Splitting and Joining          *note str.split(): 10ac.    *note str.rsplit(): 145d.       *note bytes.split(): 2602.    *note bytes.rsplit(): 2603.
                                                                                                                         
                                                                                                                         
*note str.splitlines(): 145e.                                   *note bytes.splitlines(): 2604.
                                                                
                                                                                                                         
*note str.partition(): 10ad.                                    *note bytes.partition(): 2605.
                                                                
                                                                                                                         
*note str.rpartition(): 1460.                                   *note bytes.rpartition(): 2606.
                                                                
                                                                                                                         
*note str.join(): 25e8.                                         *note bytes.join(): 25e9.
                                                                
                                                                                                                              
String Classification          *note str.isalpha(): 2607.                                  *note bytes.isalpha(): 2608.
                                                                                           
                                                                                                                         
*note str.isdecimal(): 2609.

*note str.isdigit(): 260a.                                      *note bytes.isdigit(): 260b.
                                                                
                                                                                                                         
*note str.isnumeric(): 260c.

*note str.isalnum(): 260d.                                      *note bytes.isalnum(): 260e.
                                                                
                                                                                                                         
*note str.isidentifier(): 1d2e.

*note str.islower(): 260f.                                      *note bytes.islower(): 2610.
                                                                
                                                                                                                         
*note str.isupper(): 2611.                                      *note bytes.isupper(): 2612.
                                                                
                                                                                                                         
*note str.istitle(): 2613.                                      *note bytes.istitle(): 2614.
                                                                
                                                                                                                         
*note str.isspace(): 2615.                                      *note bytes.isspace(): 2616.
                                                                
                                                                                                                         
*note str.isprintable(): fda.

Case Manipulation              *note str.lower(): 1b5e.                                    *note bytes.lower(): 2617.
                                                                                           
                                                                                                                         
*note str.upper(): 2618.                                        *note bytes.upper(): 2619.
                                                                
                                                                                                                         
*note str.casefold(): fd8.

*note str.capitalize(): 261a.                                   *note bytes.capitalize(): 261b.
                                                                
                                                                                                                         
*note str.title(): 261c.                                        *note bytes.title(): 261d.
                                                                
                                                                                                                         
*note str.swapcase(): 261e.                                     *note bytes.swapcase(): 261f.
                                                                
                                                                                                                              
Padding and Stripping          *note str.ljust(): 204c.    *note str.rjust(): 204b.        *note bytes.ljust(): 2620.    *note bytes.rjust(): 2621.
                                                                                                                         
                                                                                                                         
*note str.center(): 204d.                                       *note bytes.center(): 2622.
                                                                
                                                                                                                         
*note str.expandtabs(): 2623.                                   *note bytes.expandtabs(): 2624.
                                                                
                                                                                                                         
*note str.strip(): 16b6.                                        *note bytes.strip(): 2625.
                                                                
                                                                                                                         
*note str.lstrip(): 16b7.                                  *note str.rstrip(): 16b8.*note bytes.lstrip(): 2626.          *note bytes.rstrip(): 2627.
                                                                                                                         
                                                                                                                              
Translation and Encoding       *note str.translate(): 2628.                                *note bytes.translate(): 2629.
                                                                                           
                                                                                                                         
*note str.maketrans(): fdb.                                     *note bytes.maketrans(): 147c.
                                                                
                                                                                                                         
*note str.encode(): ad4.

                                                                *note bytes.decode(): ad5.
                                                                


File: python.info,  Node: Tipo Sequenza di Testo — str,  Next: Tipi di sequenze binarie — bytes bytearray memoryview,  Prev: Text and Binary Sequence Type Methods Summary,  Up: Tipi incorporati

5.4.9 Tipo Sequenza di Testo — ‘str’
------------------------------------

I dati testuali in Python sono gestiti con oggetti *note str: 169, o
'string'.  Le stringhe sono *note sequenze: 2018. immutabili di punti di
codice Unicode.  I letterali stringa possono essere scritti in vari
modi:

   * Apici singoli: ‘'allows embedded "double" quotes'’

   * Apici doppi: ‘"allows embedded 'single' quotes"’

   * Apici tripli: ‘'''Three single quotes'''’, ‘"""Three double
     quotes"""’

Le stringhe con tripla virgoletta possono estendersi su più righe -
tutti gli spazi bianchi associati saranno inclusi nel letterale della
stringa.

I letterali di stringa che fanno parte di una singola espressione e
contengono solo spazi bianchi tra di loro saranno convertiti
implicitamente in un singolo letterale di stringa.  Cioè, ‘("spam "
"eggs") == "spam eggs"’.

Vedi *note String and Bytes literals: 2288. per ulteriori dettagli sulle
varie forme di letterali di stringa, comprese le *note sequenze di
escape: 688. supportate, e il prefisso ‘r’ («raw») che disabilita la
maggior parte delle elaborazioni delle sequenze di escape.

Le stringhe possono anche essere create da altri oggetti utilizzando il
costruttore *note str: 169.

Poiché non esiste un tipo «carattere» separato, l’indicizzazione di una
stringa produce stringhe di lunghezza 1.  Cioè, per una stringa non
vuota 's', ‘s[0] == s[0:1]’.

Inoltre, non esiste un tipo di stringa mutabile, ma *note str.join():
25e8. o *note io.StringIO: 112b. possono essere usati per costruire
efficientemente stringhe da più frammenti.

Cambiato nella versione 3.3: Per retrocompatibilità con la serie Python
2, il prefisso ‘u’ è nuovamente permesso sui letterali di stringa.  Non
ha effetto sul significato dei letterali di stringa e non può essere
combinato con il prefisso ‘r’.

 -- Classe: str (*, encoding='utf-8', errors='strict')

 -- Classe: str (object)

 -- Classe: str (object, encoding, errors='strict')

 -- Classe: str (object, *, errors)

     Restituisce una versione *note stringa: 1fc9. di 'object'.  Se
     'object' non viene fornito, restituisce la stringa vuota.
     Altrimenti, il comportamento di ‘str()’ dipende dalla presenza di
     'encoding' o 'errors', come segue.

     Se né 'encoding' né 'errors' vengono forniti, ‘str(object)’
     restituisce *note type(object).__str__(object): 831. che è la
     rappresentazione «informale» o ben stampabile di 'object'.  Per gli
     oggetti stringa, questa è la stringa stessa.  Se 'object' non ha un
     metodo *note __str__(): 831, allora *note str(): 169. ricorre alla
     restituzione di *note repr(object): 1c1.

     Se viene fornito almeno uno tra 'encoding' o 'errors', 'object'
     dovrebbe essere un *note bytes-like object: 193. (ad es.  *note
     bytes: 192. o *note bytearray: 344.).  In questo caso, se 'object'
     è un oggetto *note bytes: 192. (o *note bytearray: 344.), allora
     ‘str(bytes, encoding, errors)’ è equivalente a *note
     bytes.decode(encoding, errors): ad5.  Altrimenti, l’oggetto bytes
     sottostante l’oggetto buffer viene ottenuto prima di chiamare *note
     bytes.decode(): ad5.  Vedi *note Tipi di sequenze binarie — bytes,
     bytearray, memoryview: 25a0. e *note Buffer Protocol: 260. per
     informazioni sugli oggetti buffer.

     Passare un oggetto *note bytes: 192. a *note str(): 169. senza
     argomenti 'encoding' o 'errors' rientra nel primo caso che
     restituisce la rappresentazione informale della stringa (vedi anche
     l’opzione della riga di comando *note -b: 7fa. di Python).  Per
     esempio:

          >>> str(b'Zoot!')
          "b'Zoot!'"

     Per maggiori informazioni sulla classe ‘str’ e i suoi metodi,
     vedere *note Tipo Sequenza di Testo — str: 1fc9. e la sezione *note
     Metodi per le Stringhe: 1fca. qui sotto.  Per generare stringhe
     formattate, vedere le sezioni *note f-strings: 19a. e *note Format
     String Syntax: 15a3.  Inoltre, vedere la sezione *note Text
     Processing Services: 262b.

* Menu:

* Metodi per le Stringhe::
* Formatted String Literals (f-strings): Formatted String Literals f-strings.
* Template String Literals (t-strings): Template String Literals t-strings.
* Formattazione delle stringhe in stile printf::


File: python.info,  Node: Metodi per le Stringhe,  Next: Formatted String Literals f-strings,  Up: Tipo Sequenza di Testo — str

5.4.9.1 Metodi per le Stringhe
..............................

Le stringhe implementano tutte le operazioni delle sequenze *note
comuni: 25e6, insieme ai metodi aggiuntivi descritti di seguito.

Le stringhe supportano anche due stili di formattazione delle stringhe,
uno che fornisce un alto grado di flessibilità e personalizzazione (vedi
*note str.format(): 834, *note Format String Syntax: 15a3. e *note
Custom String Formatting: 262d.) e l’altro basato sulla formattazione in
stile C ‘printf’ che gestisce una gamma più ristretta di tipi ed è
leggermente più difficile da usare correttamente, ma è spesso più veloce
nei casi che può gestire (*note Formattazione delle stringhe in stile
printf: 8dc.).

La sezione *note Text Processing Services: 262e. della libreria standard
copre un certo numero di altri moduli che forniscono vari utilità
relative al testo (incluso il supporto per le espressioni regolari nel
modulo *note re: be.).

 -- Metodo: str.capitalize ()

     Restituisce una copia della stringa con il primo carattere in
     maiuscolo e il resto in minuscolo.

     Cambiato nella versione 3.8: Il primo carattere è ora convertito in
     titlecase piuttosto che in maiuscolo.  Questo significa che
     caratteri come i digrammi avranno solo la prima lettera maiuscola,
     invece del carattere completo.

 -- Metodo: str.casefold ()

     Restituisce una copia della stringa normalizzata in minuscolo.  Le
     stringhe normalizzate in minuscolo possono essere utilizzate per
     confronti senza distinzione tra maiuscole e minuscole.

     Casefolding is similar to lowercasing but more aggressive because
     it is intended to remove all case distinctions in a string.  For
     example, the German lowercase letter ‘'ß'’ is equivalent to ‘"ss"’.
     Since it is already lowercase, *note lower(): 1b5e. would do
     nothing to ‘'ß'’; *note casefold(): fd8. converts it to ‘"ss"’.
     For example:

          >>> 'straße'.lower()
          'straße'
          >>> 'straße'.casefold()
          'strasse'

     The casefolding algorithm is described in section 3.13 'Default
     Case Folding' of the Unicode Standard(1).

     Added in version 3.3.

 -- Metodo: str.center (width, fillchar=' ', /)

     Return centered in a string of length 'width'.  Padding is done
     using the specified 'fillchar' (default is an ASCII space).  The
     original string is returned if 'width' is less than or equal to
     ‘len(s)’.  For example:

          >>> 'Python'.center(10)
          '  Python  '
          >>> 'Python'.center(10, '-')
          '--Python--'
          >>> 'Python'.center(4)
          'Python'

 -- Metodo: str.count (sub[, start[, end]])

     Restituisce il numero di occorrenze non sovrapposte della
     sottostringa 'sub' nell’intervallo ['start', 'end'].  Gli argomenti
     opzionali 'start' e 'end' sono interpretati come nella notazione
     delle slice.

     If 'sub' is empty, returns the number of empty strings between
     characters which is the length of the string plus one.  For
     example:

          >>> 'spam, spam, spam'.count('spam')
          3
          >>> 'spam, spam, spam'.count('spam', 5)
          2
          >>> 'spam, spam, spam'.count('spam', 5, 10)
          1
          >>> 'spam, spam, spam'.count('eggs')
          0
          >>> 'spam, spam, spam'.count('')
          17

 -- Metodo: str.encode (encoding='utf-8', errors='strict')

     Restituisce la stringa codificata in *note bytes: 192.

     'encoding' di default è ‘'utf-8'’; vedere *note Standard Encodings:
     fba. per i valori possibili.

     'errors' controlla come vengono gestiti gli errori di codifica.  Se
     ‘'strict'’ (il default), viene sollevata un’eccezione *note
     UnicodeError: 462.  Altri valori possibili sono ‘'ignore'’,
     ‘'replace'’, ‘'xmlcharrefreplace'’, ‘'backslashreplace'’ e
     qualsiasi altro nome registrato tramite *note
     codecs.register_error(): 16a2.  Vedi *note Error Handlers: 1b57.
     per dettagli.

     For performance reasons, the value of 'errors' is not checked for
     validity unless an encoding error actually occurs, *note Python
     Development Mode: 509. is enabled or a *note debug build: 50a. is
     used.  For example:

          >>> encoded_str_to_bytes = 'Python'.encode()
          >>> type(encoded_str_to_bytes)
          <class 'bytes'>
          >>> encoded_str_to_bytes
          b'Python'

     Cambiato nella versione 3.1: Aggiunto supporto per argomenti di
     tipo keyword.

     Cambiato nella versione 3.9: Il valore dell’argomento 'errors' ora
     viene controllato in *note Python Development Mode: 509. e in *note
     modalità di debug: 50a.

 -- Metodo: str.endswith (suffix[, start[, end]])

     Return ‘True’ if the string ends with the specified 'suffix',
     otherwise return ‘False’.  'suffix' can also be a tuple of suffixes
     to look for.  With optional 'start', test beginning at that
     position.  With optional 'end', stop comparing at that position.
     Using 'start' and 'end' is equivalent to
     ‘str[start:end].endswith(suffix)’.  For example:

          >>> 'Python'.endswith('on')
          True
          >>> 'a tuple of suffixes'.endswith(('at', 'in'))
          False
          >>> 'a tuple of suffixes'.endswith(('at', 'es'))
          True
          >>> 'Python is amazing'.endswith('is', 0, 9)
          True

     See also *note startswith(): 10cd. and *note removesuffix(): acf.

 -- Metodo: str.expandtabs (tabsize=8)

     Return a copy of the string where all tab characters are replaced
     by one or more spaces, depending on the current column and the
     given tab size.  Tab positions occur every 'tabsize' characters
     (default is 8, giving tab positions at columns 0, 8, 16 and so on).
     To expand the string, the current column is set to zero and the
     string is examined character by character.  If the character is a
     tab (‘\t’), one or more space characters are inserted in the result
     until the current column is equal to the next tab position.  (The
     tab character itself is not copied.)  If the character is a newline
     (‘\n’) or return (‘\r’), it is copied and the current column is
     reset to zero.  Any other character is copied unchanged and the
     current column is incremented by one regardless of how the
     character is represented when printed.  For example:

          >>> '01\t012\t0123\t01234'.expandtabs()
          '01      012     0123    01234'
          >>> '01\t012\t0123\t01234'.expandtabs(4)
          '01  012 0123    01234'
          >>> print('01\t012\n0123\t01234'.expandtabs(4))
          01  012
          0123    01234

 -- Metodo: str.find (sub[, start[, end]])

     Return the lowest index in the string where substring 'sub' is
     found within the slice ‘s[start:end]’.  Optional arguments 'start'
     and 'end' are interpreted as in slice notation.  Return ‘-1’ if
     'sub' is not found.  For example:

          >>> 'spam, spam, spam'.find('sp')
          0
          >>> 'spam, spam, spam'.find('sp', 5)
          6

     See also *note rfind(): 10ab. and *note index(): 19a4.

          Nota: Il metodo *note find(): 10aa. dovrebbe essere utilizzato
          solo se si ha bisogno di conoscere la posizione di 'sub'.  Per
          verificare se 'sub' è una sottostringa o meno, usa l’operatore
          *note in: 34b.:

               >>> 'Py' in 'Python'
               True

 -- Metodo: str.format (*args, **kwargs)

     Perform a string formatting operation.  The string on which this
     method is called can contain literal text or replacement fields
     delimited by braces ‘{}’.  Each replacement field contains either
     the numeric index of a positional argument, or the name of a
     keyword argument.  Returns a copy of the string where each
     replacement field is replaced with the string value of the
     corresponding argument.  For example:

          >>> "The sum of 1 + 2 is {0}".format(1+2)
          'The sum of 1 + 2 is 3'
          >>> "The sum of {a} + {b} is {answer}".format(answer=1+2, a=1, b=2)
          'The sum of 1 + 2 is 3'
          >>> "{1} expects the {0} Inquisition!".format("Spanish", "Nobody")
          'Nobody expects the Spanish Inquisition!'

     Vedi *note Format String Syntax: 15a3. per una descrizione delle
     varie opzioni di formattazione che possono essere specificate nelle
     stringhe di formattazione.

          Nota: Quando si formatta un numero (*note int: 19b, *note
          float: 196, *note complex: 197, *note decimal.Decimal: 1fe. e
          sottoclassi) con il tipo ‘n’ (es: ‘'{:n}'.format(1234)’), la
          funzione imposta temporaneamente il locale ‘LC_CTYPE’ sul
          locale ‘LC_NUMERIC’ per decodificare i campi ‘decimal_point’ e
          ‘thousands_sep’ di ‘localeconv()’ se sono non-ASCII o più
          lunghi di 1 byte, e il locale ‘LC_NUMERIC’ è diverso dal
          locale ‘LC_CTYPE’.  Questo cambiamento temporaneo influisce su
          altri thread.

     Cambiato nella versione 3.7: Quando si formatta un numero con il
     tipo ‘n’, la funzione imposta temporaneamente il locale ‘LC_CTYPE’
     sul locale ‘LC_NUMERIC’ in alcuni casi.

 -- Metodo: str.format_map (mapping, /)

     Simile a ‘str.format(**mapping)’, tranne che ‘mapping’ viene
     utilizzato direttamente e non copiato in un *note dict: 183.
     Questo è utile se, per esempio, ‘mapping’ è una sottoclasse di
     dict:

          >>> class Default(dict):
          ...     def __missing__(self, key):
          ...         return key
          ...
          >>> '{name} was born in {country}'.format_map(Default(name='Guido'))
          'Guido was born in country'

     Added in version 3.2.

 -- Metodo: str.index (sub[, start[, end]])

     Like *note find(): 10aa, but raise *note ValueError: 2ec. when the
     substring is not found.  For example:

          >>> 'spam, spam, spam'.index('eggs')
          Traceback (most recent call last):
            File "<python-input-0>", line 1, in <module>
              'spam, spam, spam'.index('eggs')
              ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
          ValueError: substring not found

     See also *note rindex(): 145f.

 -- Metodo: str.isalnum ()

     Restituisce ‘True’ se tutti i caratteri della stringa sono
     alfanumerici e c’è almeno un carattere, ‘False’ altrimenti.  Un
     carattere ‘c’ è alfanumerico se uno dei seguenti restituisce
     ‘True’: ‘c.isalpha()’, ‘c.isdecimal()’, ‘c.isdigit()’, o
     ‘c.isnumeric()’.

 -- Metodo: str.isalpha ()

     Return ‘True’ if all characters in the string are alphabetic and
     there is at least one character, ‘False’ otherwise.  Alphabetic
     characters are those characters defined in the Unicode character
     database as «Letter», i.e., those with general category property
     being one of «Lm», «Lt», «Lu», «Ll», or «Lo».  Note that this is
     different from the Alphabetic property defined in the section 4.10
     'Letters, Alphabetic, and Ideographic' of the Unicode Standard(2).
     For example:

          >>> 'Letters and spaces'.isalpha()
          False
          >>> 'LettersOnly'.isalpha()
          True
          >>> 'µ'.isalpha()  # non-ASCII characters can be considered alphabetical too
          True

     See *note Unicode Properties: 262f.

 -- Metodo: str.isascii ()

     Return ‘True’ if the string is empty or all characters in the
     string are ASCII, ‘False’ otherwise.  ASCII characters have code
     points in the range U+0000-U+007F. For example:

          >>> 'ASCII characters'.isascii()
          True
          >>> 'µ'.isascii()
          False

     Added in version 3.7.

 -- Metodo: str.isdecimal ()

     Return ‘True’ if all characters in the string are decimal
     characters and there is at least one character, ‘False’ otherwise.
     Decimal characters are those that can be used to form numbers in
     base 10, such as U+0660, ARABIC-INDIC DIGIT ZERO. Formally a
     decimal character is a character in the Unicode General Category
     «Nd».  For example:

          >>> '0123456789'.isdecimal()
          True
          >>> '٠١٢٣٤٥٦٧٨٩'.isdecimal()  # Arabic-Indic digits zero to nine
          True
          >>> 'alphabetic'.isdecimal()
          False

 -- Metodo: str.isdigit ()

     Restituisce ‘True’ se tutti i caratteri della stringa sono cifre e
     c’è almeno un carattere, ‘False’ altrimenti.  Le cifre includono i
     caratteri decimali e le cifre che necessitano di una gestione
     speciale, come le cifre in apice di compatibilità.  Questo copre le
     cifre che non possono essere usate per formare numeri in base 10,
     come i numeri Kharosthi.  Formalmente, una cifra è un carattere che
     ha la proprietà Numeric_Type=Digit o Numeric_Type=Decimal.

 -- Metodo: str.isidentifier ()

     Restituisce ‘True’ se la stringa è un identificatore valido secondo
     la definizione del linguaggio, sezione *note Names (identifiers and
     keywords): 2289.

     *note keyword.iskeyword(): 2630. può essere utilizzata per testare
     se la stringa ‘s’ è un identificatore riservato, come *note def:
     1661. e *note class: 14df.

     Esempio:

          >>> from keyword import iskeyword

          >>> 'hello'.isidentifier(), iskeyword('hello')
          (True, False)
          >>> 'def'.isidentifier(), iskeyword('def')
          (True, True)

 -- Metodo: str.islower ()

     Restituisce ‘True’ se tutti i caratteri con distinzione di
     maiuscole e minuscole (3) della stringa sono minuscoli e c’è almeno
     un carattere con distinzione di maiuscole e minuscole, ‘False’
     altrimenti.

 -- Metodo: str.isnumeric ()

     Return ‘True’ if all characters in the string are numeric
     characters, and there is at least one character, ‘False’ otherwise.
     Numeric characters include digit characters, and all characters
     that have the Unicode numeric value property, e.g.  U+2155, VULGAR
     FRACTION ONE FIFTH. Formally, numeric characters are those with the
     property value Numeric_Type=Digit, Numeric_Type=Decimal or
     Numeric_Type=Numeric.  For example:

          >>> '0123456789'.isnumeric()
          True
          >>> '٠١٢٣٤٥٦٧٨٩'.isnumeric()  # Arabic-indic digit zero to nine
          True
          >>> '⅕'.isnumeric()  # Vulgar fraction one fifth
          True
          >>> '²'.isdecimal(), '²'.isdigit(),  '²'.isnumeric()
          (False, True, True)

     See also *note isdecimal(): 2609. and *note isdigit(): 260a.
     Numeric characters are a superset of decimal numbers.

 -- Metodo: str.isprintable ()

     Return ‘True’ if all characters in the string are printable,
     ‘False’ if it contains at least one non-printable character.

     Here «printable» means the character is suitable for *note repr():
     1c1. to use in its output; «non-printable» means that *note repr():
     1c1. on built-in types will hex-escape the character.  It has no
     bearing on the handling of strings written to *note sys.stdout:
     ccf. or *note sys.stderr: b35.

     The printable characters are those which in the Unicode character
     database (see *note unicodedata: 10b.) have a general category in
     group Letter, Mark, Number, Punctuation, or Symbol (L, M, N, P, or
     S); plus the ASCII space 0x20.  Nonprintable characters are those
     in group Separator or Other (Z or C), except the ASCII space.

     For example:

          >>> ''.isprintable(), ' '.isprintable()
          (True, True)
          >>> '\t'.isprintable(), '\n'.isprintable()
          (False, False)

 -- Metodo: str.isspace ()

     Restituisce ‘True’ se ci sono solo caratteri di spazio nella
     stringa e c’è almeno un carattere, altrimenti ‘False’.

     Un carattere è 'spazio' se nel database dei caratteri Unicode (vedi
     *note unicodedata: 10b.) la sua categoria generale è ‘Zs’
     («Separator, space»), o se la sua classe bidirezionale è una delle
     seguenti ‘WS’, ‘B’, o ‘S’.

 -- Metodo: str.istitle ()

     Restituisce ‘True’ se la stringa è una stringa con iniziale
     maiuscola e c’è almeno un carattere; ad esempio, i caratteri
     maiuscoli possono seguire solo caratteri senza distinzione
     maiuscola o minuscola e i caratteri minuscoli solo quelli con
     distinzione.  Restituisce ‘False’ altrimenti.

     For example:

          >>> 'Spam, Spam, Spam'.istitle()
          True
          >>> 'spam, spam, spam'.istitle()
          False
          >>> 'SPAM, SPAM, SPAM'.istitle()
          False

     See also *note title(): 261c.

 -- Metodo: str.isupper ()

     Restituisce ‘True’ se tutti i caratteri con distinzione (4) nella
     stringa sono maiuscoli e c’è almeno un carattere con distinzione,
     altrimenti ‘False’.

          >>> 'BANANA'.isupper()
          True
          >>> 'banana'.isupper()
          False
          >>> 'baNana'.isupper()
          False
          >>> ' '.isupper()
          False

 -- Metodo: str.join (iterable, /)

     Return a string which is the concatenation of the strings in
     'iterable'.  A *note TypeError: 198. will be raised if there are
     any non-string values in 'iterable', including *note bytes: 192.
     objects.  The separator between elements is the string providing
     this method.  For example:

          >>> ', '.join(['spam', 'spam', 'spam'])
          'spam, spam, spam'
          >>> '-'.join('Python')
          'P-y-t-h-o-n'

     See also *note split(): 10ac.

 -- Metodo: str.ljust (width, fillchar=' ', /)

     Restituisce la stringa allineata a sinistra in una stringa di
     lunghezza 'width'.  La spaziatura viene eseguita utilizzando il
     'fillchar' specificato (il valore predefinito è uno spazio ASCII).
     La stringa originale viene restituita se 'width' è minore o uguale
     alla lunghezza di ‘len(s)’.

     For example:

          >>> 'Python'.ljust(10)
          'Python    '
          >>> 'Python'.ljust(10, '.')
          'Python....'
          >>> 'Monty Python'.ljust(10, '.')
          'Monty Python'

     See also *note rjust(): 204b.

 -- Metodo: str.lower ()

     Return a copy of the string with all the cased characters (5)
     converted to lowercase.  For example:

          >>> 'Lower Method Example'.lower()
          'lower method example'

     The lowercasing algorithm used is described in section 3.13
     'Default Case Folding' of the Unicode Standard(6).

 -- Metodo: str.lstrip (chars=None, /)

     Restituisce una copia della stringa con i caratteri iniziali
     rimossi.  L’argomento 'chars' è una stringa che specifica l’insieme
     di caratteri da rimuovere.  Se omesso o ‘None’, l’argomento 'chars'
     predefinito rimuove gli spazi bianchi.  L’argomento 'chars' non è
     un prefisso; piuttosto, tutte le combinazioni dei suoi valori
     vengono rimosse:

          >>> '   spacious   '.lstrip()
          'spacious   '
          >>> 'www.example.com'.lstrip('cmowz.')
          'example.com'

     Vedi *note str.removeprefix(): ace. per un metodo che rimuova un
     singolo prefisso stringa piuttosto che tutti i caratteri di un
     insieme.  Ad esempio:

          >>> 'Arthur: three!'.lstrip('Arthur: ')
          'ee!'
          >>> 'Arthur: three!'.removeprefix('Arthur: ')
          'three!'

 -- Metodo: static str.maketrans (dict, /)

 -- Metodo: static str.maketrans (from, to, remove='', /)

     Questo metodo statico restituisce una tabella di traduzione
     utilizzabile per *note str.translate(): 2628.

     Se c’è solo un argomento, deve essere un dizionario che mappa gli
     ordinali Unicode (interi) o caratteri (stringhe di lunghezza 1) a
     ordinali Unicode, stringhe (di lunghezza arbitraria) o ‘None’.  Le
     chiavi dei caratteri verranno quindi convertite in ordinali.

     If there are two arguments, they must be strings of equal length,
     and in the resulting dictionary, each character in 'from' will be
     mapped to the character at the same position in 'to'.  If there is
     a third argument, it must be a string, whose characters will be
     mapped to ‘None’ in the result.

 -- Metodo: str.partition (sep, /)

     Divide la stringa alla prima occorrenza di 'sep', e restituisce una
     tuple a 3 elementi contenente la parte prima del separatore, il
     separatore stesso, e la parte dopo il separatore.  Se il separatore
     non viene trovato, restituisce una tuple a 3 elementi contenente la
     stringa stessa, seguita da due stringhe vuote.

 -- Metodo: str.removeprefix (prefix, /)

     If the string starts with the 'prefix' string, return
     ‘string[len(prefix):]’.  Otherwise, return a copy of the original
     string:

          >>> 'TestHook'.removeprefix('Test')
          'Hook'
          >>> 'BaseTestCase'.removeprefix('Test')
          'BaseTestCase'

     Added in version 3.9.

     See also *note removesuffix(): acf. and *note startswith(): 10cd.

 -- Metodo: str.removesuffix (suffix, /)

     If the string ends with the 'suffix' string and that 'suffix' is
     not empty, return ‘string[:-len(suffix)]’.  Otherwise, return a
     copy of the original string:

          >>> 'MiscTests'.removesuffix('Tests')
          'Misc'
          >>> 'TmpDirMixin'.removesuffix('Tests')
          'TmpDirMixin'

     Added in version 3.9.

     See also *note removeprefix(): ace. and *note endswith(): 10ce.

 -- Metodo: str.replace (old, new, /, count=-1)

     Return a copy of the string with all occurrences of substring 'old'
     replaced by 'new'.  If 'count' is given, only the first 'count'
     occurrences are replaced.  If 'count' is not specified or ‘-1’,
     then all occurrences are replaced.  For example:

          >>> 'spam, spam, spam'.replace('spam', 'eggs')
          'eggs, eggs, eggs'
          >>> 'spam, spam, spam'.replace('spam', 'eggs', 1)
          'eggs, spam, spam'

     Cambiato nella versione 3.13: 'count' è ora supportato come
     argomento di parola chiave.

 -- Metodo: str.rfind (sub[, start[, end]])

     Return the highest index in the string where substring 'sub' is
     found, such that 'sub' is contained within ‘s[start:end]’.
     Optional arguments 'start' and 'end' are interpreted as in slice
     notation.  Return ‘-1’ on failure.  For example:

          >>> 'spam, spam, spam'.rfind('sp')
          12
          >>> 'spam, spam, spam'.rfind('sp', 0, 10)
          6

     See also *note find(): 10aa. and *note rindex(): 145f.

 -- Metodo: str.rindex (sub[, start[, end]])

     Come *note rfind(): 10ab. ma solleva *note ValueError: 2ec. quando
     la sottostringa 'sub' non viene trovata.

 -- Metodo: str.rjust (width, fillchar=' ', /)

     Restituisce la stringa allineata a destra in una stringa di
     lunghezza 'width'.  La spaziatura viene eseguita utilizzando il
     'fillchar' specificato (il valore predefinito è uno spazio ASCII).
     La stringa originale viene restituita se 'width' è minore o uguale
     alla lunghezza di ‘len(s)’.

 -- Metodo: str.rpartition (sep, /)

     Divide la stringa all’ultima occorrenza di 'sep', e restituisce una
     tuple a 3 elementi contenente la parte prima del separatore, il
     separatore stesso, e la parte dopo il separatore.  Se il separatore
     non viene trovato, restituisce una tuple a 3 elementi contenente
     due stringhe vuote, seguite dalla stringa stessa.

     For example:

          >>> 'Monty Python'.rpartition(' ')
          ('Monty', ' ', 'Python')
          >>> "Monty Python's Flying Circus".rpartition(' ')
          ("Monty Python's Flying", ' ', 'Circus')
          >>> 'Monty Python'.rpartition('-')
          ('', '', 'Monty Python')

     See also *note partition(): 10ad.

 -- Metodo: str.rsplit (sep=None, maxsplit=-1)

     Restituisce un elenco delle parole nella stringa, utilizzando 'sep'
     come stringa delimitante.  Se è dato 'maxsplit', sono eseguite al
     massimo 'maxsplit' divisioni, quelle più a destra.  Se 'sep' non è
     specificato o è ‘None’, qualsiasi stringa di spazi bianchi è un
     separatore.  A eccezione della divisione da destra, *note rsplit():
     145d. si comporta come *note split(): 10ac. che viene descritto in
     dettaglio sotto.

 -- Metodo: str.rstrip (chars=None, /)

     Restituisce una copia della stringa con i caratteri finali rimossi.
     L’argomento 'chars' è una stringa che specifica l’insieme di
     caratteri da rimuovere.  Se omesso o ‘None’, l’argomento 'chars'
     predefinito rimuove gli spazi bianchi.  L’argomento 'chars' non è
     un suffisso; piuttosto, tutte le combinazioni dei suoi valori
     vengono rimosse:

          >>> '   spacious   '.rstrip()
          '   spacious'
          >>> 'mississippi'.rstrip('ipz')
          'mississ'

     Vedi *note str.removesuffix(): acf. per un metodo che rimuova un
     singolo suffisso stringa piuttosto che tutti i caratteri di un
     insieme.  Ad esempio:

          >>> 'Monty Python'.rstrip(' Python')
          'M'
          >>> 'Monty Python'.removesuffix(' Python')
          'Monty'

 -- Metodo: str.split (sep=None, maxsplit=-1)

     Restituisce un elenco delle parole nella stringa, utilizzando 'sep'
     come stringa delimitante.  Se è dato 'maxsplit', sono eseguite al
     massimo 'maxsplit' divisioni (quindi, l’elenco avrà al massimo
     ‘maxsplit+1’ elementi).  Se 'maxsplit' non è specificato o è ‘-1’,
     allora non c’è limite al numero di divisioni (vengono eseguite
     tutte le divisioni possibili).

     If 'sep' is given, consecutive delimiters are not grouped together
     and are deemed to delimit empty strings (for example,
     ‘'1,,2'.split(',')’ returns ‘['1', '', '2']’).  The 'sep' argument
     may consist of multiple characters as a single delimiter (to split
     with multiple delimiters, use *note re.split(): 5a2.).  Splitting
     an empty string with a specified separator returns ‘['']’.

     Ad esempio:

          >>> '1,2,3'.split(',')
          ['1', '2', '3']
          >>> '1,2,3'.split(',', maxsplit=1)
          ['1', '2,3']
          >>> '1,2,,3,'.split(',')
          ['1', '2', '', '3', '']
          >>> '1<>2<>3<4'.split('<>')
          ['1', '2', '3<4']

     Se 'sep' non è specificato o è ‘None’, viene applicato un algoritmo
     di divisione diverso: sequenze di spazi bianchi consecutivi sono
     considerate come un unico separatore, e il risultato non conterrà
     stringhe vuote all’inizio o alla fine se la stringa ha spazi
     bianchi iniziali o finali.  Di conseguenza, dividendo una stringa
     vuota o una stringa composta solo di spazi bianchi con un
     separatore ‘None’ si ottiene ‘[]’.

     Ad esempio:

          >>> '1 2 3'.split()
          ['1', '2', '3']
          >>> '1 2 3'.split(maxsplit=1)
          ['1', '2 3']
          >>> '   1   2   3   '.split()
          ['1', '2', '3']

     If 'sep' is not specified or is ‘None’ and 'maxsplit' is ‘0’, only
     leading runs of consecutive whitespace are considered.

     Ad esempio:

          >>> "".split(None, 0)
          []
          >>> "   ".split(None, 0)
          []
          >>> "   foo   ".split(maxsplit=0)
          ['foo   ']

     See also *note join(): 25e8.

 -- Metodo: str.splitlines (keepends=False)

     Restituisce un elenco delle righe nella stringa, suddividendo alle
     linee di demarcazione.  Le interruzioni di linea non sono incluse
     nell’elenco risultante a meno che 'keepends' non sia dato e vero.

     Questo metodo divide sulle seguenti linee di demarcazione.  In
     particolare, i confini sono un sovrainsieme delle *note universal
     newlines: f37.

     Rappresentazione            Descrizione
                                 
     --------------------------------------------------------------
                                 
     ‘\n’                        Line Feed
                                 
                                 
     ‘\r’                        Carriage Return
                                 
                                 
     ‘\r\n’                      Carriage Return + Line Feed
                                 
                                 
     ‘\v’ o ‘\x0b’               Line Tabulation
                                 
                                 
     ‘\f’ o ‘\x0c’               Form Feed
                                 
                                 
     ‘\x1c’                      File Separator
                                 
                                 
     ‘\x1d’                      Group Separator
                                 
                                 
     ‘\x1e’                      Record Separator
                                 
                                 
     ‘\x85’                      Codice di controllo C1 «Next
                                 Line»
                                 
                                 
     ‘\u2028’                    Separatore di riga
                                 
                                 
     ‘\u2029’                    Separatore di paragrafo
                                 

     Cambiato nella versione 3.2: ‘\v’ e ‘\f’ aggiunti all’elenco dei
     limiti di riga.

     Ad esempio:

          >>> 'ab c\n\nde fg\rkl\r\n'.splitlines()
          ['ab c', '', 'de fg', 'kl']
          >>> 'ab c\n\nde fg\rkl\r\n'.splitlines(keepends=True)
          ['ab c\n', '\n', 'de fg\r', 'kl\r\n']

     A differenza del metodo *note split(): 10ac. quando viene fornita
     una stringa delimitatore 'sep', questo metodo restituisce una lista
     vuota per la stringa vuota e un’interruzione di riga terminale non
     comporta una linea aggiuntiva:

          >>> "".splitlines()
          []
          >>> "One line\n".splitlines()
          ['One line']

     Per confronto, ‘split('\n')’ restituisce:

          >>> ''.split('\n')
          ['']
          >>> 'Two lines\n'.split('\n')
          ['Two lines', '']

 -- Metodo: str.startswith (prefix[, start[, end]])

     Restituisce ‘True’ se la stringa inizia con il 'prefisso',
     altrimenti restituisce ‘False’.  'prefix' può essere anche una
     tupla di prefissi da cercare.  Con 'start' opzionale, testa la
     stringa iniziando da quella posizione.  Con 'end' opzionale, smette
     di confrontare la stringa in quella posizione.

 -- Metodo: str.strip (chars=None, /)

     Restituisce una copia della stringa con i caratteri iniziali e
     finali rimossi.  L’argomento 'chars' è una stringa che specifica
     l’insieme dei caratteri da rimuovere.  Se omesso o ‘None’,
     l’argomento 'chars' predefinisce la rimozione degli spazi bianchi.
     L’argomento 'chars' non è un prefisso o un suffisso; piuttosto,
     tutte le combinazioni dei suoi valori vengono eliminate:

          >>> '   spacious   '.strip()
          'spacious'
          >>> 'www.example.com'.strip('cmowz.')
          'example'

     I valori esterni iniziali e finali dell’argomento 'chars' vengono
     rimossi dalla stringa.  I caratteri vengono rimossi dall’inizio
     fino a raggiungere un carattere della stringa che non è contenuto
     nel set di caratteri in 'chars'.  Un’azione simile avviene alla
     fine.  Per esempio:

          >>> comment_string = '#....... Section 3.2.1 Issue #32 .......'
          >>> comment_string.strip('.#! ')
          'Section 3.2.1 Issue #32'

 -- Metodo: str.swapcase ()

     Restituisce una copia della stringa con i caratteri maiuscoli
     convertiti in minuscoli e viceversa.  Nota che non è
     necessariamente vero che ‘s.swapcase().swapcase() == s’.

 -- Metodo: str.title ()

     Restituisce una versione della stringa con iniziali maiuscole, dove
     le parole iniziano con un carattere maiuscolo e i caratteri
     rimanenti sono minuscoli.

     Ad esempio:

          >>> 'Hello world'.title()
          'Hello World'

     L’algoritmo utilizza una semplice definizione indipendente dalla
     lingua di una parola come gruppi di lettere consecutive.  La
     definizione funziona in molti contesti, ma ciò significa che gli
     apostrofi nelle contrazioni e nei possessivi formano confini di
     parola, il che potrebbe non essere il risultato desiderato:

          >>> "they're bill's friends from the UK".title()
          "They'Re Bill'S Friends From The Uk"

     La funzione *note string.capwords(): 2632. non ha questo problema,
     poiché divide le parole solo sugli spazi.

     In alternativa, è possibile costruire una soluzione per gli
     apostrofi utilizzando le espressioni regolari:

          >>> import re
          >>> def titlecase(s):
          ...     return re.sub(r"[A-Za-z]+('[A-Za-z]+)?",
          ...                   lambda mo: mo.group(0).capitalize(),
          ...                   s)
          ...
          >>> titlecase("they're bill's friends.")
          "They're Bill's Friends."

     See also *note istitle(): 2613.

 -- Metodo: str.translate (table, /)

     Restituisce una copia della stringa in cui ciascun carattere è
     stato mappato attraverso la tabella di traduzione fornita.  La
     tabella deve essere un oggetto che implementa l’indicizzazione
     tramite *note __getitem__(): 588, tipicamente un *note mapping:
     13c3. o una *note sequence: 717.  Quando indicizzato tramite un
     ordinale Unicode (un intero), l’oggetto tabella può fare una delle
     seguenti azioni: restituire un ordinale Unicode o una stringa, per
     mappare il carattere a uno o più altri caratteri; restituire
     ‘None’, per eliminare il carattere dalla stringa di ritorno; o
     lanciare un’eccezione *note LookupError: 2633, per mappare il
     carattere a se stesso.

     Puoi usare *note str.maketrans(): fdb. per creare una mappa di
     traduzione da mappature carattere-a-carattere in diversi formati.

     Vedi anche il modulo *note codecs: 1c. per un approccio più
     flessibile alle mappature personalizzate dei caratteri.

 -- Metodo: str.upper ()

     Restituisce una copia della stringa con tutti i caratteri (7) in
     maiuscolo convertiti in maiuscolo.  Nota che ‘s.upper().isupper()’
     potrebbe essere ‘False’ se ‘s’ contiene caratteri non maiuscoli o
     se la categoria Unicode dei caratteri risultanti non è «Lu»
     (Lettera, maiuscolo), ma ad esempio «Lt» (Lettera, titolo).

     The uppercasing algorithm used is described in section 3.13
     'Default Case Folding' of the Unicode Standard(8).

 -- Metodo: str.zfill (width, /)

     Restituisce una copia della stringa riempita a sinistra con cifre
     ASCII ‘'0'’ per fare una stringa della lunghezza 'width'.  Un
     prefisso di segno principale (‘'+'’/‘'-'’) viene gestito inserendo
     il padding 'dopo' il carattere del segno piuttosto che prima.  La
     stringa originale viene restituita se 'width' è minore o uguale a
     ‘len(s)’.

     Ad esempio:

          >>> "42".zfill(5)
          '00042'
          >>> "-42".zfill(5)
          '-0042'

   ---------- Footnotes ----------

   (1) 
https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-3/#G33992

   (2) 
https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-4/#G91002

   (3) I caratteri con distinzione di maiuscole e minuscole sono quelli
con proprietà di categoria generale «Lu» (Lettera, maiuscola), «Ll»
(Lettera, minuscola) o «Lt» (Lettera, maiuscola a inizio parola).

   (4) I caratteri con distinzione di maiuscole e minuscole sono quelli
con proprietà di categoria generale «Lu» (Lettera, maiuscola), «Ll»
(Lettera, minuscola) o «Lt» (Lettera, maiuscola a inizio parola).

   (5) I caratteri con distinzione di maiuscole e minuscole sono quelli
con proprietà di categoria generale «Lu» (Lettera, maiuscola), «Ll»
(Lettera, minuscola) o «Lt» (Lettera, maiuscola a inizio parola).

   (6) 
https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-3/#G33992

   (7) I caratteri con distinzione di maiuscole e minuscole sono quelli
con proprietà di categoria generale «Lu» (Lettera, maiuscola), «Ll»
(Lettera, minuscola) o «Lt» (Lettera, maiuscola a inizio parola).

   (8) 
https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-3/#G33992


File: python.info,  Node: Formatted String Literals f-strings,  Next: Template String Literals t-strings,  Prev: Metodi per le Stringhe,  Up: Tipo Sequenza di Testo — str

5.4.9.2 Formatted String Literals (f-strings)
.............................................

Added in version 3.6.

Cambiato nella versione 3.7: The *note await: 18d. and *note async for:
ca3. can be used in expressions within f-strings.

Cambiato nella versione 3.8: Added the debug specifier (‘=’)

Cambiato nella versione 3.12: Many restrictions on expressions within
f-strings have been removed.  Notably, nested strings, comments, and
backslashes are now permitted.

An 'f-string' (formally a 'formatted string literal') is a string
literal that is prefixed with ‘f’ or ‘F’.  This type of string literal
allows embedding the results of arbitrary Python expressions within
'replacement fields', which are delimited by curly brackets (‘{}’).
Each replacement field must contain an expression, optionally followed
by:

   * a 'debug specifier' – an equal sign (‘=’);

   * a 'conversion specifier' – ‘!s’, ‘!r’ or ‘!a’; and/or

   * a 'format specifier' prefixed with a colon (‘:’).

See the *note Lexical Analysis section on f-strings: 19a. for details on
the syntax of these fields.

* Menu:

* Debug specifier::
* Conversion specifier::
* Format specifier::


File: python.info,  Node: Debug specifier,  Next: Conversion specifier,  Up: Formatted String Literals f-strings

5.4.9.3 Debug specifier
.......................

Added in version 3.8.

If a debug specifier – an equal sign (‘=’) – appears after the
replacement field expression, the resulting f-string will contain the
expression’s source, the equal sign, and the value of the expression.
This is often useful for debugging:

     >>> number = 14.3
     >>> f'{number=}'
     'number=14.3'

Whitespace before, inside and after the expression, as well as
whitespace after the equal sign, is significant — it is retained in the
result:

     >>> f'{ number  -  4  = }'
     ' number  -  4  = 10.3'


File: python.info,  Node: Conversion specifier,  Next: Format specifier,  Prev: Debug specifier,  Up: Formatted String Literals f-strings

5.4.9.4 Conversion specifier
............................

By default, the value of a replacement field expression is converted to
a string using *note str(): 169.:

     >>> from fractions import Fraction
     >>> one_third = Fraction(1, 3)
     >>> f'{one_third}'
     '1/3'

When a debug specifier but no format specifier is used, the default
conversion instead uses *note repr(): 1c1.:

     >>> f'{one_third = }'
     'one_third = Fraction(1, 3)'

The conversion can be specified explicitly using one of these
specifiers:

   * ‘!s’ for *note str(): 169.

   * ‘!r’ for *note repr(): 1c1.

   * ‘!a’ for *note ascii(): 15ed.

Ad esempio:

     >>> str(one_third)
     '1/3'
     >>> repr(one_third)
     'Fraction(1, 3)'

     >>> f'{one_third!s} is {one_third!r}'
     '1/3 is Fraction(1, 3)'

     >>> string = "¡kočka 😸!"
     >>> ascii(string)
     "'\\xa1ko\\u010dka \\U0001f638!'"

     >>> f'{string = !a}'
     "string = '\\xa1ko\\u010dka \\U0001f638!'"


File: python.info,  Node: Format specifier,  Prev: Conversion specifier,  Up: Formatted String Literals f-strings

5.4.9.5 Format specifier
........................

After the expression has been evaluated, and possibly converted using an
explicit conversion specifier, it is formatted using the *note format():
199. function.  If the replacement field includes a 'format specifier'
introduced by a colon (‘:’), the specifier is passed to ‘format()’ as
the second argument.  The result of ‘format()’ is then used as the final
value for the replacement field.  For example:

     >>> from fractions import Fraction
     >>> one_third = Fraction(1, 3)
     >>> f'{one_third:.6f}'
     '0.333333'
     >>> f'{one_third:_^+10}'
     '___+1/3___'
     >>> >>> f'{one_third!r:_^20}'
     '___Fraction(1, 3)___'
     >>> f'{one_third = :~>10}~'
     'one_third = ~~~~~~~1/3~'


File: python.info,  Node: Template String Literals t-strings,  Next: Formattazione delle stringhe in stile printf,  Prev: Formatted String Literals f-strings,  Up: Tipo Sequenza di Testo — str

5.4.9.6 Template String Literals (t-strings)
............................................

An 't-string' (formally a 'template string literal') is a string literal
that is prefixed with ‘t’ or ‘T’.

These strings follow the same syntax and evaluation rules as *note
formatted string literals: 22d4, with for the following differences:

   * Rather than evaluating to a ‘str’ object, template string literals
     evaluate to a *note string.templatelib.Template: 16a. object.

   * The *note format(): 199. protocol is not used.  Instead, the format
     specifier and conversions (if any) are passed to a new *note
     Interpolation: 16b. object that is created for each evaluated
     expression.  It is up to code that processes the resulting *note
     Template: 16a. object to decide how to handle format specifiers and
     conversions.

   * Format specifiers containing nested replacement fields are
     evaluated eagerly, prior to being passed to the *note
     Interpolation: 16b. object.  For instance, an interpolation of the
     form ‘{amount:.{precision}f}’ will evaluate the inner expression
     ‘{precision}’ to determine the value of the ‘format_spec’
     attribute.  If ‘precision’ were to be ‘2’, the resulting format
     specifier would be ‘'.2f'’.

   * When the equals sign ‘'='’ is provided in an interpolation
     expression, the text of the expression is appended to the literal
     string that precedes the relevant interpolation.  This includes the
     equals sign and any surrounding whitespace.  The ‘Interpolation’
     instance for the expression will be created as normal, except that
     *note conversion: 2639. will be set to “‘r’” (*note repr(): 1c1.)
     by default.  If an explicit conversion or format specifier are
     provided, this will override the default behaviour.


File: python.info,  Node: Formattazione delle stringhe in stile printf,  Prev: Template String Literals t-strings,  Up: Tipo Sequenza di Testo — str

5.4.9.7 Formattazione delle stringhe in stile ‘printf’
......................................................

     Nota: The formatting operations described here exhibit a variety of
     quirks that lead to a number of common errors (such as failing to
     display tuples and dictionaries correctly).

     Using *note formatted string literals: 19a, the *note str.format():
     834. interface, or *note string.Template: 898. may help avoid these
     errors.  Each of these alternatives provides their own trade-offs
     and benefits of simplicity, flexibility, and/or extensibility.

Gli oggetti stringa hanno un’operazione integrata unica: l’operatore ‘%’
(modulo).  Questo è anche noto come operatore di 'formattazione' o
'interpolazione' della stringa.  Data ‘format % values’ (dove 'format' è
una stringa), le specifiche di conversione ‘%’ in 'format' sono
sostituite con uno o più elementi di 'values'.  L’effetto è simile
all’uso della funzione ‘sprintf()’ nel linguaggio C. Per esempio:

     >>> print('%s has %d quote types.' % ('Python', 2))
     Python has 2 quote types.

Se 'format' richiede un singolo argomento, 'values' può essere un
singolo oggetto che non è una tupla.  (1)  Altrimenti, 'values' deve
essere una tupla con esattamente il numero di elementi specificati dalla
stringa di formattazione, o un singolo oggetto di mappatura (ad esempio,
un dizionario).

Uno specificatore di conversione contiene due o più caratteri e ha i
seguenti componenti, che devono apparire in questo ordine:

  1. Il carattere ‘'%'’, che segna l’inizio dello specificatore.

  2. Chiave di mappatura (opzionale), costituita da una sequenza tra
     parentesi di caratteri (ad esempio, ‘(somename)’).

  3. Flag di conversione (opzionali), che influiscono sul risultato di
     alcuni tipi di conversione.

  4. Larghezza minima del campo (opzionale).  Se specificata come ‘'*'’
     (asterisco), la larghezza effettiva viene letta dal prossimo
     elemento della tupla in 'values', e l’oggetto da convertire viene
     dopo la larghezza minima del campo e la precisione opzionale.

  5. Precisione (opzionale), data come ‘'.'’ (punto) seguita dalla
     precisione.  Se specificata come ‘'*'’ (un asterisco), la
     precisione effettiva viene letta dal prossimo elemento della tupla
     in 'values', e il valore da convertire viene dopo la precisione.

  6. Modificatore di lunghezza (opzionale).

  7. Tipo di conversione.

Quando l’argomento di destra è un dizionario (o un altro tipo di
mappatura), i formati nella stringa 'devono' includere una chiave di
mappatura tra parentesi in quel dizionario inserita immediatamente dopo
il carattere ‘'%'’.  La chiave di mappatura seleziona il valore da
formattare dalla mappatura.  Ad esempio:

     >>> print('%(language)s has %(number)03d quote types.' %
     ...       {'language': "Python", "number": 2})
     Python has 002 quote types.

In questo caso non possono comparire specificatori ‘*’ in un formato
(poiché richiedono un elenco di parametri sequenziale).

I caratteri di flag di conversione sono:

Flag          Significato
              
----------------------------------------------------------------------------------------
              
‘'#'’         La conversione del valore utilizzerà la «forma alternativa» (dove
              definita di seguito).
              
              
‘'0'’         La conversione sarà riempita di zeri per i valori numerici.
              
              
‘'-'’         Il valore convertito è allineato a sinistra (sovrascrive la conversione
              ‘'0'’ se entrambi sono forniti).
              
              
‘' '’         (uno spazio) Uno spazio vuoto dovrebbe essere lasciato prima di un
              numero positivo (o stringa vuota) prodotto da una conversione con
              segno.
              
              
‘'+'’         Un carattere di segno (‘'+'’ o ‘'-'’) precederà la conversione
              (sovrascrive un flag «spazio»).
              

Un modificatore di lunghezza (‘h’, ‘l’, o ‘L’) può essere presente, ma
viene ignorato poiché non è necessario per Python – quindi ad esempio
‘%ld’ è identico a ‘%d’.

I tipi di conversione sono:

Conversione      Significato                                               Note
                                                                           
---------------------------------------------------------------------------------------
                                                                           
‘'d'’            Intero con segno decimale.
                 
                                                                           
‘'i'’            Intero con segno decimale.
                 
                                                                           
‘'o'’            Valore ottale con segno.                                  (1)
                                                                           
                                                                           
‘'u'’            Tipo obsoleto – è identico a ‘'d'’.                       (6)
                                                                           
                                                                           
‘'x'’            Esadecimale con segno (minuscolo).                        (2)
                                                                           
                                                                           
‘'X'’            Esadecimale con segno (maiuscolo).                        (2)
                                                                           
                                                                           
‘'e'’            Floating-point exponential format (lowercase).            (3)
                                                                           
                                                                           
‘'E'’            Floating-point exponential format (uppercase).            (3)
                                                                           
                                                                           
‘'f'’            Floating-point decimal format.                            (3)
                                                                           
                                                                           
‘'F'’            Floating-point decimal format.                            (3)
                                                                           
                                                                           
‘'g'’            Floating-point format.  Uses lowercase exponential        (4)
                 format if exponent is less than -4 or not less than       
                 precision, decimal format otherwise.
                 
                                                                           
‘'G'’            Floating-point format.  Uses uppercase exponential        (4)
                 format if exponent is less than -4 or not less than       
                 precision, decimal format otherwise.
                 
                                                                           
‘'c'’            Singolo carattere (accetta un intero o una stringa di
                 un singolo carattere).
                 
                                                                           
‘'r'’            Stringa (converte qualsiasi oggetto Python usando         (5)
                 *note repr(): 1c1.).                                      
                 
                                                                           
‘'s'’            Stringa (converte qualsiasi oggetto Python usando         (5)
                 *note str(): 169.).                                       
                 
                                                                           
‘'a'’            Stringa (converte qualsiasi oggetto Python usando         (5)
                 *note ascii(): 15ed.).                                    
                 
                                                                           
‘'%'’            Nessun argomento viene convertito, il risultato è un
                 carattere ‘'%'’ nel risultato.
                 

Note:

  1. La forma alternativa fa sì che venga inserito un prefisso ottale
     (‘'0o'’) prima della prima cifra.

  2. La forma alternativa fa sì che venga inserito un prefisso ‘'0x'’ o
     ‘'0X'’ (a seconda che sia stato usato il formato ‘'x'’ o ‘'X'’)
     prima della prima cifra.

  3. La forma alternativa fa sì che il risultato contenga sempre un
     punto decimale, anche se non ci sono cifre che seguono.

     La precisione determina il numero di cifre dopo il punto decimale e
     il valore predefinito è 6.

  4. La forma alternativa fa sì che il risultato contenga sempre un
     punto decimale e gli zeri finali non vengono rimossi come
     avverrebbe altrimenti.

     La precisione determina il numero di cifre significative prima e
     dopo il punto decimale e il valore predefinito è 6.

  5. Se la precisione è ‘N’, l’output è troncato a ‘N’ caratteri.

  6. Vedi PEP 237(2).

Poiché le stringhe Python hanno una lunghezza esplicita, le conversioni
‘%s’ non assumono che ‘'\0'’ sia la fine della stringa.

Cambiato nella versione 3.1: Le conversioni ‘%f’ per i numeri il cui
valore assoluto è superiore a 1e50 non vengono più sostituite dalle
conversioni ‘%g’.

   ---------- Footnotes ----------

   (1) Per formattare solo una tupla, dovresti quindi fornire una tupla
singleton il cui unico elemento è la tupla da formattare.

   (2) https://peps.python.org/pep-0237/


File: python.info,  Node: Tipi di sequenze binarie — bytes bytearray memoryview,  Next: Tipi di Insiemi — set frozenset,  Prev: Tipo Sequenza di Testo — str,  Up: Tipi incorporati

5.4.10 Tipi di sequenze binarie — ‘bytes’, ‘bytearray’, ‘memoryview’
--------------------------------------------------------------------

I tipi incorporati principali per manipolare i dati binari sono *note
bytes: 192. e *note bytearray: 344.  Sono supportati da *note
memoryview: 165. che utilizza il *note protocollo buffer: 260. per
accedere alla memoria di altri oggetti binari senza necessità di fare
una copia.

Il modulo *note array: 8. supporta l’archiviazione efficiente di tipi di
dati di base come interi a 32 bit e valori a virgola mobile a doppia
precisione IEEE754.

* Menu:

* Oggetti bytes::
* Oggetti Bytearray::
* Operazioni su Bytes e Bytearray::
* Formattazione Bytes stile printf::
* Memory Views::


File: python.info,  Node: Oggetti bytes,  Next: Oggetti Bytearray,  Up: Tipi di sequenze binarie — bytes bytearray memoryview

5.4.10.1 Oggetti bytes
......................

Gli oggetti bytes sono sequenze immutabili di singoli byte.  Poiché
molti protocolli binari principali sono basati sulla codifica del testo
ASCII, gli oggetti bytes offrono diversi metodi validi solo quando si
lavora con dati compatibili con ASCII e sono strettamente correlati agli
oggetti stringa in vari altri modi.

 -- Classe: bytes (source=b'')

 -- Classe: bytes (source, encoding, errors='strict')

     In primo luogo, la sintassi per i letterali bytes è sostanzialmente
     la stessa di quella per i letterali stringa, tranne per il fatto
     che viene aggiunto un prefisso ‘b’:

        * Virgolette singole: ‘b'still allows embedded "double" quotes'’

        * Virgolette doppie: ‘b"still allows embedded 'single' quotes"’

        * Virgolette triple: ‘b'''3 single quotes'''’, ‘b"""3 double
          quotes"""’

     Sono permessi solo caratteri ASCII nei letterali bytes
     (indipendentemente dalla codifica dichiarata del codice sorgente).
     Qualsiasi valore binario superiore a 127 deve essere inserito nei
     letterali bytes usando la sequenza di escape appropriata.

     Come per i letterali stringa, i letterali bytes possono anche usare
     il prefisso ‘r’ per disabilitare l’elaborazione delle sequenze di
     escape.  Vedi *note String and Bytes literals: 2288. per maggiori
     informazioni sulle varie forme di letterali bytes, comprese le
     sequenze di escape supportate.

     Sebbene i letterali bytes e le loro rappresentazioni si basino sul
     testo ASCII, gli oggetti bytes si comportano effettivamente come
     sequenze immutabili di interi, con ciascun valore nella sequenza
     limitato in modo tale che ‘0 <= x < 256’ (i tentativi di violare
     questa restrizione attiveranno *note ValueError: 2ec.).  Questo
     viene fatto deliberatamente per enfatizzare che, sebbene molti
     formati binari includano elementi basati su ASCII e possano essere
     utilmente manipolati con alcuni algoritmi orientati al testo,
     questo non è generalmente il caso per dati binari arbitrari
     (applicare ciecamente algoritmi di elaborazione del testo a formati
     di dati binari non compatibili con ASCII di solito porta a
     corruzione dei dati).

     Oltre alle forme letterali, gli oggetti bytes possono essere creati
     in diversi altri modi:

        * Un oggetto bytes riempito di zeri di una lunghezza
          specificata: ‘bytes(10)’

        * Da un iterable di interi: ‘bytes(range(20))’

        * Copiando dati binari esistenti tramite il protocollo buffer:
          ‘bytes(obj)’

     Vedi anche il built-in *note bytes: 1e82.

     Poiché 2 cifre esadecimali corrispondono esattamente a un singolo
     byte, i numeri esadecimali sono un formato comunemente usato per
     descrivere i dati binari.  Di conseguenza, il tipo bytes ha un
     metodo di classe aggiuntivo per leggere i dati in tale formato:

      -- Metodo: classmethod fromhex (string, /)

          Questo metodo di classe *note bytes: 192. restituisce un
          oggetto bytes, decodificando il dato oggetto stringa.  La
          stringa deve contenere due cifre esadecimali per byte, e gli
          spazi bianchi ASCII vengono ignorati.

               >>> bytes.fromhex('2Ef0 F1f2  ')
               b'.\xf0\xf1\xf2'

          Cambiato nella versione 3.7: *note bytes.fromhex(): 190. ora
          salta tutti gli spazi bianchi ASCII nella stringa, non solo
          gli spazi.

          Cambiato nella versione 3.14: *note bytes.fromhex(): 190. now
          accepts ASCII *note bytes: 192. and *note bytes-like objects:
          193. as input.

     Esiste una funzione di conversione inversa per trasformare un
     oggetto bytes nella sua rappresentazione esadecimale.

      -- Metodo: hex (*, bytes_per_sep=1)

      -- Metodo: hex (sep, bytes_per_sep=1)

          Restituisce un oggetto stringa contenente due cifre
          esadecimali per ogni byte nell’istanza.

               >>> b'\xf0\xf1\xf2'.hex()
               'f0f1f2'

          Se vuoi rendere la stringa esadecimale più leggibile, puoi
          specificare un parametro separatore 'sep' per includere un
          singolo carattere nell’output.  Per impostazione predefinita,
          questo separatore verrà incluso tra ogni byte.  Un secondo
          parametro opzionale 'bytes_per_sep' controlla la spaziatura.
          I valori positivi calcolano la posizione del separatore da
          destra, i valori negativi da sinistra.

               >>> value = b'\xf0\xf1\xf2'
               >>> value.hex('-')
               'f0-f1-f2'
               >>> value.hex('_', 2)
               'f0_f1f2'
               >>> b'UUDDLRLRAB'.hex(' ', -4)
               '55554444 4c524c52 4142'

          Added in version 3.5.

          Cambiato nella versione 3.8: *note bytes.hex(): f67. ora
          supporta i parametri opzionali 'sep' e 'bytes_per_sep' per
          inserire separatori tra i byte nell’output esadecimale.

Poiché gli oggetti bytes sono sequenze di interi (simili a una tupla),
per un oggetto bytes 'b', ‘b[0]’ sarà un intero, mentre ‘b[0:1]’ sarà un
oggetto bytes di lunghezza 1.  (Questo contrasta con le stringhe di
testo, dove sia l’indicizzazione che il slicing produrranno una stringa
di lunghezza 1)

La rappresentazione degli oggetti bytes usa il formato letterale
(‘b'...'’) poiché è spesso più utile di, ad esempio, ‘bytes([46, 46,
46])’.  Puoi sempre convertire un oggetto bytes in una lista di interi
usando ‘list(b)’.


File: python.info,  Node: Oggetti Bytearray,  Next: Operazioni su Bytes e Bytearray,  Prev: Oggetti bytes,  Up: Tipi di sequenze binarie — bytes bytearray memoryview

5.4.10.2 Oggetti Bytearray
..........................

Gli oggetti *note bytearray: 344. sono una controparte mutabile degli
oggetti *note bytes: 192.

 -- Classe: bytearray (source=b'')

 -- Classe: bytearray (source, encoding, errors='strict')

     Non esiste una sintassi letterale dedicata per gli oggetti
     bytearray, essi vengono sempre creati chiamando il costruttore:

        * Creazione di un’istanza vuota: ‘bytearray()’

        * Creazione di un’istanza riempita di zeri con una lunghezza
          data: ‘bytearray(10)’

        * Da un iterable di interi: ‘bytearray(range(20))’

        * Copiando dati binari esistenti tramite il protocollo buffer:
          ‘bytearray(b'Hi!')’

     Poiché gli oggetti bytearray sono mutabili, supportano le
     operazioni di sequenza *note mutable: 259e. oltre alle comuni
     operazioni bytes e bytearray descritte in *note Operazioni su Bytes
     e Bytearray: 259f.

     Vedi anche il built-in *note bytearray: 1e83.

     Poiché 2 cifre esadecimali corrispondono esattamente a un singolo
     byte, i numeri esadecimali sono un formato comunemente usato per
     descrivere i dati binari.  Di conseguenza, il tipo bytearray ha un
     metodo di classe aggiuntivo per leggere i dati in tale formato:

      -- Metodo: classmethod fromhex (string, /)

          Questo metodo di classe *note bytearray: 344. restituisce un
          oggetto bytearray, decodificando il dato oggetto stringa.  La
          stringa deve contenere due cifre esadecimali per byte, e gli
          spazi bianchi ASCII vengono ignorati.

               >>> bytearray.fromhex('2Ef0 F1f2  ')
               bytearray(b'.\xf0\xf1\xf2')

          Cambiato nella versione 3.7: *note bytearray.fromhex(): 191.
          ora salta tutti gli spazi bianchi ASCII nella stringa, non
          solo gli spazi.

          Cambiato nella versione 3.14: *note bytearray.fromhex(): 191.
          now accepts ASCII *note bytes: 192. and *note bytes-like
          objects: 193. as input.

     Esiste una funzione di conversione inversa per trasformare un
     oggetto bytearray nella sua rappresentazione esadecimale.

      -- Metodo: hex (*, bytes_per_sep=1)

      -- Metodo: hex (sep, bytes_per_sep=1)

          Restituisce un oggetto stringa contenente due cifre
          esadecimali per ogni byte nell’istanza.

               >>> bytearray(b'\xf0\xf1\xf2').hex()
               'f0f1f2'

          Added in version 3.5.

          Cambiato nella versione 3.8: Simile a *note bytes.hex(): f67,
          *note bytearray.hex(): f68. ora supporta i parametri opzionali
          'sep' e 'bytes_per_sep' per inserire separatori tra i byte
          nell’output esadecimale.

      -- Metodo: resize (size, /)

          Resize the *note bytearray: 344. to contain 'size' bytes.
          'size' must be greater than or equal to 0.

          If the *note bytearray: 344. needs to shrink, bytes beyond
          'size' are truncated.

          If the *note bytearray: 344. needs to grow, all new bytes,
          those beyond 'size', will be set to null bytes.

          This is equivalent to:

               >>> def resize(ba, size):
               ...     if len(ba) > size:
               ...         del ba[size:]
               ...     else:
               ...         ba += b'\0' * (size - len(ba))

          Examples:

               >>> shrink = bytearray(b'abc')
               >>> shrink.resize(1)
               >>> (shrink, len(shrink))
               (bytearray(b'a'), 1)
               >>> grow = bytearray(b'abc')
               >>> grow.resize(5)
               >>> (grow, len(grow))
               (bytearray(b'abc\x00\x00'), 5)

          Added in version 3.14.

Poiché gli oggetti bytearray sono sequenze di interi (simili a una
lista), per un oggetto bytearray 'b', ‘b[0]’ sarà un intero, mentre
‘b[0:1]’ sarà un oggetto bytearray di lunghezza 1.  (Questo contrasta
con le stringhe di testo, dove sia l’indicizzazione che il slicing
produrranno una stringa di lunghezza 1)

La rappresentazione degli oggetti bytearray usa il formato letterale
bytes (‘bytearray(b'...')’) poiché è spesso più utile di, ad esempio,
‘bytearray([46, 46, 46])’.  Puoi sempre convertire un oggetto bytearray
in una lista di interi usando ‘list(b)’.


File: python.info,  Node: Operazioni su Bytes e Bytearray,  Next: Formattazione Bytes stile printf,  Prev: Oggetti Bytearray,  Up: Tipi di sequenze binarie — bytes bytearray memoryview

5.4.10.3 Operazioni su Bytes e Bytearray
........................................

Sia gli oggetti bytes che bytearray supportano le operazioni di sequenza
*note common: 25e6.  Essi interoperano non solo con operandi dello
stesso tipo, ma con qualsiasi *note bytes-like object: 193.  Grazie a
questa flessibilità, possono essere liberamente mescolati nelle
operazioni senza causare errori.  Tuttavia, il tipo restituito del
risultato può dipendere dall’ordine degli operandi.

     Nota: I metodi sugli oggetti bytes e bytearray non accettano
     stringhe come argomenti, così come i metodi sulle stringhe non
     accettano bytes come argomenti.  Ad esempio, devi scrivere:

          a = "abc"
          b = a.replace("a", "f")

     e:

          a = b"abc"
          b = a.replace(b"a", b"f")

Alcune operazioni su bytes e bytearray presumono l’uso di formati binari
compatibili con ASCII e, pertanto, dovrebbero essere evitate quando si
lavora con dati binari arbitrari.  Queste restrizioni sono trattate di
seguito.

     Nota: Utilizzare queste operazioni basate su ASCII per manipolare
     dati binari che non sono memorizzati in un formato basato su ASCII
     può portare a corruzione dei dati.

I seguenti metodi sugli oggetti bytes e bytearray possono essere
utilizzati con dati binari arbitrari.

 -- Metodo: bytes.count (sub[, start[, end]])
 -- Metodo: bytearray.count (sub[, start[, end]])

     Restituisce il numero di occorrenze non sovrapposte della
     sottosequenza 'sub' nell’intervallo ['start', 'end'].  Gli
     argomenti opzionali 'start' e 'end' sono interpretati come nella
     notazione di slice.

     La sottosequenza da cercare può essere qualsiasi *note bytes-like
     object: 193. o un intero nell’intervallo da 0 a 255.

     Se 'sub' è vuoto, restituisce il numero di slice vuoti tra i
     caratteri che è la lunghezza dell’oggetto bytes più uno.

     Cambiato nella versione 3.3: Accetta anche un intero
     nell’intervallo da 0 a 255 come sottosequenza.

 -- Metodo: bytes.removeprefix (prefix, /)
 -- Metodo: bytearray.removeprefix (prefix, /)

     Se i dati binari iniziano con la stringa 'prefix', restituisce
     ‘bytes[len(prefix):]’.  Altrimenti, restituisce una copia dei dati
     binari originali:

          >>> b'TestHook'.removeprefix(b'Test')
          b'Hook'
          >>> b'BaseTestCase'.removeprefix(b'Test')
          b'BaseTestCase'

     Il 'prefix' può essere qualsiasi *note bytes-like object: 193.

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

     Added in version 3.9.

 -- Metodo: bytes.removesuffix (suffix, /)
 -- Metodo: bytearray.removesuffix (suffix, /)

     Se i dati binari terminano con la stringa 'suffix' e questo
     'suffix' non è vuoto, ritorna ‘bytes[:-len(suffix)]’.  Altrimenti,
     ritorna una copia dei dati binari originali:

          >>> b'MiscTests'.removesuffix(b'Tests')
          b'Misc'
          >>> b'TmpDirMixin'.removesuffix(b'Tests')
          b'TmpDirMixin'

     Il 'suffix' può essere qualsiasi *note oggetto simile a bytes: 193.

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

     Added in version 3.9.

 -- Metodo: bytes.decode (encoding='utf-8', errors='strict')
 -- Metodo: bytearray.decode (encoding='utf-8', errors='strict')

     Restituisce i bytes decodificati in una *note str: 169.

     'encoding' di default è ‘'utf-8'’; vedere *note Standard Encodings:
     fba. per i valori possibili.

     'errors' controlla come vengono gestiti gli errori di decodifica.
     Se ‘'strict'’ (il valore predefinito), viene sollevata un’eccezione
     *note UnicodeError: 462.  Altri valori possibili sono ‘'ignore'’,
     ‘'replace'’, e qualsiasi altro nome registrato tramite *note
     codecs.register_error(): 16a2.  Vedi *note Error Handlers: 1b57.
     per i dettagli.

     Per ragioni di prestazioni, il valore di 'errors' non viene
     verificato per validità a meno che non si verifichi effettivamente
     un errore di decodifica, sia abilitato *note Python Development
     Mode: 509. o venga utilizzata una *note build di debug: 50a.

          Nota: Passare l’argomento 'encoding' a *note str: 169.
          permette di decodificare qualsiasi *note oggetto simile a
          bytes: 193. direttamente, senza dover creare un oggetto
          temporaneo ‘bytes’ o ‘bytearray’.

     Cambiato nella versione 3.1: Aggiunto supporto per argomenti di
     tipo keyword.

     Cambiato nella versione 3.9: Il valore dell’argomento 'errors' ora
     viene controllato in *note Python Development Mode: 509. e in *note
     modalità di debug: 50a.

 -- Metodo: bytes.endswith (suffix[, start[, end]])
 -- Metodo: bytearray.endswith (suffix[, start[, end]])

     Restituisce ‘True’ se i dati binari terminano con il 'suffix'
     specificato, altrimenti restituisce ‘False’.  'suffix' può essere
     anche una tupla di suffissi da cercare.  Con 'start' opzionale, il
     test inizia a quella posizione.  Con 'end' opzionale, smette di
     confrontare a quella posizione.

     Il/i suffisso/i da cercare possono essere qualsiasi *note oggetto
     simile a bytes: 193.

 -- Metodo: bytes.find (sub[, start[, end]])
 -- Metodo: bytearray.find (sub[, start[, end]])

     Restituisce l’indice più basso nei dati dove si trova la
     sottosequenza 'sub', tale che 'sub' sia contenuto nella slice
     ‘s[start:end]’.  Gli argomenti opzionali 'start' e 'end' sono
     interpretati come nella notazione delle slice.  Restituisce ‘-1’ se
     'sub' non viene trovato.

     La sottosequenza da cercare può essere qualsiasi *note bytes-like
     object: 193. o un intero nell’intervallo da 0 a 255.

          Nota: Il metodo *note find(): 1bbc. dovrebbe essere utilizzato
          solo se hai bisogno di conoscere la posizione di 'sub'.  Per
          verificare se 'sub' è una sottostringa o no, usa l’operatore
          *note in: 34b.:

               >>> b'Py' in b'Python'
               True

     Cambiato nella versione 3.3: Accetta anche un intero
     nell’intervallo da 0 a 255 come sottosequenza.

 -- Metodo: bytes.index (sub[, start[, end]])
 -- Metodo: bytearray.index (sub[, start[, end]])

     Come *note find(): 1bbc, ma solleva *note ValueError: 2ec. quando
     la sottosequenza non viene trovata.

     La sottosequenza da cercare può essere qualsiasi *note bytes-like
     object: 193. o un intero nell’intervallo da 0 a 255.

     Cambiato nella versione 3.3: Accetta anche un intero
     nell’intervallo da 0 a 255 come sottosequenza.

 -- Metodo: bytes.join (iterable, /)
 -- Metodo: bytearray.join (iterable, /)

     Restituisce un oggetto bytes o bytearray che è la concatenazione
     delle sequenze di dati binari in 'iterable'.  Verrà sollevata una
     *note TypeError: 198. se ci sono valori in 'iterable' che non sono
     *note oggetti simili a bytes: 193, inclusi gli oggetti *note str:
     169.  Il separatore tra gli elementi è il contenuto dell’oggetto
     bytes o bytearray che fornisce questo metodo.

 -- Metodo: static bytes.maketrans (from, to, /)
 -- Metodo: static bytearray.maketrans (from, to, /)

     Questo metodo statico restituisce una tabella di traduzione
     utilizzabile per *note bytes.translate(): 2629. che mapperà ciascun
     carattere in 'from' nel carattere nella stessa posizione in 'to';
     'from' e 'to' devono essere entrambi *note oggetti simili a bytes:
     193. e avere la stessa lunghezza.

     Added in version 3.1.

 -- Metodo: bytes.partition (sep, /)
 -- Metodo: bytearray.partition (sep, /)

     Divide la sequenza alla prima occorrenza di 'sep', e restituisce
     una tupla a 3 elementi contenente la parte prima del separatore, il
     separatore stesso o la sua copia bytearray, e la parte dopo il
     separatore.  Se il separatore non viene trovato, restituisce una
     tupla a 3 elementi contenente una copia della sequenza originale,
     seguita da due oggetti vuoti bytes o bytearray.

     Il separatore da cercare può essere qualsiasi *note oggetto simile
     a bytes: 193.

 -- Metodo: bytes.replace (old, new, count=-1, /)
 -- Metodo: bytearray.replace (old, new, count=-1, /)

     Restituisce una copia della sequenza con tutte le occorrenze della
     sottosequenza 'old' sostituite da 'new'.  Se viene specificato
     l’argomento opzionale 'count', vengono sostituite solo le prime
     'count' occorrenze.

     La sottosequenza da cercare e la sua sostituzione possono essere
     qualsiasi *note oggetto simile a bytes: 193.

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.rfind (sub[, start[, end]])
 -- Metodo: bytearray.rfind (sub[, start[, end]])

     Restituisce l’indice più alto nella sequenza dove si trova la
     sottosequenza 'sub', tale che 'sub' sia contenuto in
     ‘s[start:end]’.  Gli argomenti opzionali 'start' e 'end' sono
     interpretati come nella notazione delle slice.  Restituisce ‘-1’ in
     caso di fallimento.

     La sottosequenza da cercare può essere qualsiasi *note bytes-like
     object: 193. o un intero nell’intervallo da 0 a 255.

     Cambiato nella versione 3.3: Accetta anche un intero
     nell’intervallo da 0 a 255 come sottosequenza.

 -- Metodo: bytes.rindex (sub[, start[, end]])
 -- Metodo: bytearray.rindex (sub[, start[, end]])

     Come *note rfind(): 1bbd. ma solleva *note ValueError: 2ec. quando
     la sottosequenza 'sub' non viene trovata.

     La sottosequenza da cercare può essere qualsiasi *note bytes-like
     object: 193. o un intero nell’intervallo da 0 a 255.

     Cambiato nella versione 3.3: Accetta anche un intero
     nell’intervallo da 0 a 255 come sottosequenza.

 -- Metodo: bytes.rpartition (sep, /)
 -- Metodo: bytearray.rpartition (sep, /)

     Divide la sequenza all’ultima occorrenza di 'sep', e restituisce
     una tupla a 3 elementi contenente la parte prima del separatore, il
     separatore stesso o la sua copia bytearray, e la parte dopo il
     separatore.  Se il separatore non viene trovato, restituisce una
     tupla a 3 elementi contenente due oggetti vuoti bytes o bytearray,
     seguiti da una copia della sequenza originale.

     Il separatore da cercare può essere qualsiasi *note oggetto simile
     a bytes: 193.

 -- Metodo: bytes.startswith (prefix[, start[, end]])
 -- Metodo: bytearray.startswith (prefix[, start[, end]])

     Restituisce ‘True’ se i dati binari iniziano con il 'prefix'
     specificato, altrimenti restituisce ‘False’.  'prefix' può essere
     anche una tupla di prefissi da cercare.  Con 'start' opzionale, il
     test inizia a quella posizione.  Con 'end' opzionale, smette di
     confrontare a quella posizione.

     Il/i prefisso/i da cercare possono essere qualsiasi *note oggetto
     simile a bytes: 193.

 -- Metodo: bytes.translate (table, /, delete=b'')
 -- Metodo: bytearray.translate (table, /, delete=b'')

     Restituisce una copia dell’oggetto bytes o bytearray dove tutti i
     bytes presenti nell’argomento opzionale 'delete' sono stati
     rimossi, e i bytes rimanenti sono stati mappati attraverso la
     tabella di traduzione data, che deve essere un oggetto bytes di
     lunghezza 256.

     Puoi usare il metodo *note bytes.maketrans(): 147c. per creare una
     tabella di traduzione.

     Imposta l’argomento 'table' su ‘None’ per traduzioni che eliminano
     solo i caratteri:

          >>> b'read this short text'.translate(None, b'aeiou')
          b'rd ths shrt txt'

     Cambiato nella versione 3.6: 'delete' ora è supportato come
     argomento keyword.

I seguenti metodi su oggetti bytes e bytearray hanno comportamenti
predefiniti che assumono l’uso di formati binari compatibili con ASCII,
ma possono essere comunque utilizzati con dati binari arbitrari passando
argomenti appropriati.  Nota che tutti i metodi bytearray in questa
sezione 'non' operano in place, e invece producono nuovi oggetti.

 -- Metodo: bytes.center (width, fillbyte=b' ', /)
 -- Metodo: bytearray.center (width, fillbyte=b' ', /)

     Restituisce una copia dell’oggetto centrato in una sequenza di
     lunghezza 'width'.  L’imbottitura viene fatta usando il 'fillbyte'
     specificato (il predefinito è uno spazio ASCII). Per oggetti *note
     bytes: 192, la sequenza originale viene restituita se 'width' è
     minore o uguale a ‘len(s)’.

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.ljust (width, fillbyte=b' ', /)
 -- Metodo: bytearray.ljust (width, fillbyte=b' ', /)

     Restituisce una copia dell’oggetto giustificato a sinistra in una
     sequenza di lunghezza 'width'.  L’imbottitura viene fatta usando il
     'fillbyte' specificato (il predefinito è uno spazio ASCII). Per
     oggetti *note bytes: 192, la sequenza originale viene restituita se
     'width' è minore o uguale a ‘len(s)’.

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.lstrip (bytes=None, /)
 -- Metodo: bytearray.lstrip (bytes=None, /)

     Return a copy of the sequence with specified leading bytes removed.
     The 'bytes' argument is a binary sequence specifying the set of
     byte values to be removed.  If omitted or ‘None’, the 'bytes'
     argument defaults to removing ASCII whitespace.  The 'bytes'
     argument is not a prefix; rather, all combinations of its values
     are stripped:

          >>> b'   spacious   '.lstrip()
          b'spacious   '
          >>> b'www.example.com'.lstrip(b'cmowz.')
          b'example.com'

     La sequenza binaria di valori byte da rimuovere può essere
     qualsiasi *note oggetto simile a bytes: 193.  Vedi *note
     removeprefix(): 263f. per un metodo che rimuoverà una singola
     stringa prefisso anziché tutti i caratteri di un set.  Ad esempio:

          >>> b'Arthur: three!'.lstrip(b'Arthur: ')
          b'ee!'
          >>> b'Arthur: three!'.removeprefix(b'Arthur: ')
          b'three!'

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.rjust (width, fillbyte=b' ', /)
 -- Metodo: bytearray.rjust (width, fillbyte=b' ', /)

     Restituisce una copia dell’oggetto giustificato a destra in una
     sequenza di lunghezza 'width'.  L’imbottitura viene fatta usando il
     'fillbyte' specificato (il predefinito è uno spazio ASCII). Per
     oggetti *note bytes: 192, la sequenza originale viene restituita se
     'width' è minore o uguale a ‘len(s)’.

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.rsplit (sep=None, maxsplit=-1)
 -- Metodo: bytearray.rsplit (sep=None, maxsplit=-1)

     Divide la sequenza binaria in sottosequenze dello stesso tipo,
     usando 'sep' come stringa delimitatore.  Se viene specificato
     'maxsplit', vengono effettuate al massimo 'maxsplit' divisioni, le
     ultime.  Se 'sep' non è specificato o è ‘None’, qualsiasi
     sottosequenza costituita esclusivamente da spazi bianchi ASCII è un
     separatore.  A parte per la divisione da destra, *note rsplit():
     1781. si comporta come *note split(): 1780. che è descritto in
     dettaglio di seguito.

 -- Metodo: bytes.rstrip (bytes=None, /)
 -- Metodo: bytearray.rstrip (bytes=None, /)

     Return a copy of the sequence with specified trailing bytes
     removed.  The 'bytes' argument is a binary sequence specifying the
     set of byte values to be removed.  If omitted or ‘None’, the
     'bytes' argument defaults to removing ASCII whitespace.  The
     'bytes' argument is not a suffix; rather, all combinations of its
     values are stripped:

          >>> b'   spacious   '.rstrip()
          b'   spacious'
          >>> b'mississippi'.rstrip(b'ipz')
          b'mississ'

     La sequenza binaria di valori byte da rimuovere può essere
     qualsiasi *note oggetto simile a bytes: 193.  Vedi *note
     removesuffix(): 2641. per un metodo che rimuoverà una singola
     stringa suffisso anziché tutti i caratteri di un set.  Ad esempio:

          >>> b'Monty Python'.rstrip(b' Python')
          b'M'
          >>> b'Monty Python'.removesuffix(b' Python')
          b'Monty'

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.split (sep=None, maxsplit=-1)
 -- Metodo: bytearray.split (sep=None, maxsplit=-1)

     Divide la sequenza binaria in sottosequenze dello stesso tipo,
     usando 'sep' come stringa delimitatore.  Se 'maxsplit' è dato e non
     negativo, vengono effettuate al massimo 'maxsplit' divisioni
     (quindi, la lista avrà al massimo ‘maxsplit+1’ elementi).  Se
     'maxsplit' non è specificato o è ‘-1’, non c’è limite al numero di
     divisioni (vengono effettuate tutte le possibili divisioni).

     If 'sep' is given, consecutive delimiters are not grouped together
     and are deemed to delimit empty subsequences (for example,
     ‘b'1,,2'.split(b',')’ returns ‘[b'1', b'', b'2']’).  The 'sep'
     argument may consist of a multibyte sequence as a single delimiter.
     Splitting an empty sequence with a specified separator returns
     ‘[b'']’ or ‘[bytearray(b'')]’ depending on the type of object being
     split.  The 'sep' argument may be any *note bytes-like object: 193.

     Ad esempio:

          >>> b'1,2,3'.split(b',')
          [b'1', b'2', b'3']
          >>> b'1,2,3'.split(b',', maxsplit=1)
          [b'1', b'2,3']
          >>> b'1,2,,3,'.split(b',')
          [b'1', b'2', b'', b'3', b'']
          >>> b'1<>2<>3<4'.split(b'<>')
          [b'1', b'2', b'3<4']

     Se 'sep' non è specificato o è ‘None’, viene applicato un diverso
     algoritmo di divisione: le sequenze di spazi bianchi ASCII
     consecutivi sono considerate come un singolo separatore, e il
     risultato non conterrà stringhe vuote all’inizio o alla fine se la
     sequenza ha spazi bianchi iniziali o finali.  Pertanto, dividendo
     una sequenza vuota o una sequenza costituita esclusivamente da
     spazi bianchi ASCII senza un separatore specificato si ottiene
     ‘[]’.

     Ad esempio:

          >>> b'1 2 3'.split()
          [b'1', b'2', b'3']
          >>> b'1 2 3'.split(maxsplit=1)
          [b'1', b'2 3']
          >>> b'   1   2   3   '.split()
          [b'1', b'2', b'3']

 -- Metodo: bytes.strip (bytes=None, /)
 -- Metodo: bytearray.strip (bytes=None, /)

     Return a copy of the sequence with specified leading and trailing
     bytes removed.  The 'bytes' argument is a binary sequence
     specifying the set of byte values to be removed.  If omitted or
     ‘None’, the 'bytes' argument defaults to removing ASCII whitespace.
     The 'bytes' argument is not a prefix or suffix; rather, all
     combinations of its values are stripped:

          >>> b'   spacious   '.strip()
          b'spacious'
          >>> b'www.example.com'.strip(b'cmowz.')
          b'example'

     La sequenza binaria di valori byte da rimuovere può essere
     qualsiasi *note oggetto simile a bytes: 193.

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

I seguenti metodi sugli oggetti bytes e bytearray assumono l’uso di
formati binari compatibili con ASCII e non dovrebbero essere applicati a
dati binari arbitrari.  Nota che tutti i metodi bytearray in questa
sezione 'non' operano in place, e invece producono nuovi oggetti.

 -- Metodo: bytes.capitalize ()
 -- Metodo: bytearray.capitalize ()

     Restituisce una copia della sequenza con ogni byte interpretato
     come un carattere ASCII, e il primo byte capitalizzato e il resto
     in minuscolo.  I valori dei byte non ASCII vengono trasmessi senza
     modifiche.

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.expandtabs (tabsize=8)
 -- Metodo: bytearray.expandtabs (tabsize=8)

     Restituisce una copia della sequenza dove tutti i caratteri ASCII
     tab sono sostituiti da uno o più spazi ASCII, a seconda della
     colonna corrente e della dimensione del tab fornita.  Le posizioni
     della tabulazione si verificano ogni 'tabsize' byte (il valore
     predefinito è 8, dando le posizioni della tabulazione alle colonne
     0, 8, 16 e così via).  Per espandere la sequenza, la colonna
     corrente viene impostata a zero e la sequenza viene esaminata byte
     per byte.  Se il byte è un carattere tabulazione ASCII (‘b'\t'’),
     uno o più spazi vengono inseriti nel risultato fino a quando la
     colonna corrente è uguale alla prossima posizione di tabulazione.
     (Il carattere tabulazione stesso non viene copiato.)  Se il byte
     corrente è una nuova riga ASCII (‘b'\n'’) o ritorno a capo
     (‘b'\r'’), viene copiato e la colonna corrente viene reimpostata a
     zero.  Qualsiasi altro valore di byte viene copiato senza modifiche
     e la colonna corrente viene incrementata di uno indipendentemente
     da come il valore del byte viene rappresentato quando viene
     stampato:

          >>> b'01\t012\t0123\t01234'.expandtabs()
          b'01      012     0123    01234'
          >>> b'01\t012\t0123\t01234'.expandtabs(4)
          b'01  012 0123    01234'

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.isalnum ()
 -- Metodo: bytearray.isalnum ()

     Restituisce ‘True’ se tutti i byte nella sequenza sono caratteri
     alfabetici ASCII o cifre decimali ASCII e la sequenza non è vuota,
     ‘False’ altrimenti.  I caratteri alfabetici ASCII sono quei valori
     di byte nella sequenza
     ‘b'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'’.  Le
     cifre decimali ASCII sono quei valori di byte nella sequenza
     ‘b'0123456789'’.

     Ad esempio:

          >>> b'ABCabc1'.isalnum()
          True
          >>> b'ABC abc1'.isalnum()
          False

 -- Metodo: bytes.isalpha ()
 -- Metodo: bytearray.isalpha ()

     Restituisce ‘True’ se tutti i byte nella sequenza sono caratteri
     alfabetici ASCII e la sequenza non è vuota, ‘False’ altrimenti.  I
     caratteri alfabetici ASCII sono quei valori di byte nella sequenza
     ‘b'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'’.

     Ad esempio:

          >>> b'ABCabc'.isalpha()
          True
          >>> b'ABCabc1'.isalpha()
          False

 -- Metodo: bytes.isascii ()
 -- Metodo: bytearray.isascii ()

     Restituisce ‘True’ se la sequenza è vuota o se tutti i byte nella
     sequenza sono ASCII, ‘False’ altrimenti.  I byte ASCII sono
     nell’intervallo 0-0x7F.

     Added in version 3.7.

 -- Metodo: bytes.isdigit ()
 -- Metodo: bytearray.isdigit ()

     Restituisce ‘True’ se tutti i byte nella sequenza sono cifre
     decimali ASCII e la sequenza non è vuota, ‘False’ altrimenti.  Le
     cifre decimali ASCII sono quei valori di byte nella sequenza
     ‘b'0123456789'’.

     Ad esempio:

          >>> b'1234'.isdigit()
          True
          >>> b'1.23'.isdigit()
          False

 -- Metodo: bytes.islower ()
 -- Metodo: bytearray.islower ()

     Restituisce ‘True’ se c’è almeno un carattere minuscolo ASCII nella
     sequenza e nessun carattere maiuscolo ASCII, ‘False’ altrimenti.

     Ad esempio:

          >>> b'hello world'.islower()
          True
          >>> b'Hello world'.islower()
          False

     I caratteri minuscoli ASCII sono quei valori di byte nella sequenza
     ‘b'abcdefghijklmnopqrstuvwxyz'’.  I caratteri maiuscoli ASCII sono
     quei valori di byte nella sequenza ‘b'ABCDEFGHIJKLMNOPQRSTUVWXYZ'’.

 -- Metodo: bytes.isspace ()
 -- Metodo: bytearray.isspace ()

     Restituisce ‘True’ se tutti i byte nella sequenza sono spazi
     bianchi ASCII e la sequenza non è vuota, ‘False’ altrimenti.  I
     caratteri di spazio bianco ASCII sono quei valori di byte nella
     sequenza ‘b' \t\n\r\x0b\f'’ (spazio, tabulazione, nuova riga,
     ritorno a capo, tabulazione verticale, form feed).

 -- Metodo: bytes.istitle ()
 -- Metodo: bytearray.istitle ()

     Restituisce ‘True’ se la sequenza è in formato ASCII «titlecase» e
     la sequenza non è vuota, ‘False’ altrimenti.  Vedi *note
     bytes.title(): 261d. per maggiori dettagli sulla definizione di
     «titlecase».

     Ad esempio:

          >>> b'Hello World'.istitle()
          True
          >>> b'Hello world'.istitle()
          False

 -- Metodo: bytes.isupper ()
 -- Metodo: bytearray.isupper ()

     Restituisce ‘True’ se c’è almeno un carattere alfabetico ASCII
     maiuscolo nella sequenza e nessun carattere ASCII minuscolo,
     ‘False’ altrimenti.

     Ad esempio:

          >>> b'HELLO WORLD'.isupper()
          True
          >>> b'Hello world'.isupper()
          False

     I caratteri minuscoli ASCII sono quei valori di byte nella sequenza
     ‘b'abcdefghijklmnopqrstuvwxyz'’.  I caratteri maiuscoli ASCII sono
     quei valori di byte nella sequenza ‘b'ABCDEFGHIJKLMNOPQRSTUVWXYZ'’.

 -- Metodo: bytes.lower ()
 -- Metodo: bytearray.lower ()

     Restituisce una copia della sequenza con tutti i caratteri ASCII
     maiuscoli convertiti nei loro corrispondenti caratteri minuscoli.

     Ad esempio:

          >>> b'Hello World'.lower()
          b'hello world'

     I caratteri minuscoli ASCII sono quei valori di byte nella sequenza
     ‘b'abcdefghijklmnopqrstuvwxyz'’.  I caratteri maiuscoli ASCII sono
     quei valori di byte nella sequenza ‘b'ABCDEFGHIJKLMNOPQRSTUVWXYZ'’.

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.splitlines (keepends=False)
 -- Metodo: bytearray.splitlines (keepends=False)

     Restituisce un elenco delle linee nella sequenza binaria,
     suddividendo ai confini delle linee ASCII. Questo metodo utilizza
     l’approccio delle *note universal newlines: f37. per dividere le
     linee.  Le interruzioni di linea non sono incluse nell’elenco
     risultante a meno che 'keepends' non sia fornito e impostato su
     vero.

     Ad esempio:

          >>> b'ab c\n\nde fg\rkl\r\n'.splitlines()
          [b'ab c', b'', b'de fg', b'kl']
          >>> b'ab c\n\nde fg\rkl\r\n'.splitlines(keepends=True)
          [b'ab c\n', b'\n', b'de fg\r', b'kl\r\n']

     A differenza di *note split(): 2602. quando viene dato un
     delimitatore di stringa 'sep', questo metodo restituisce un elenco
     vuoto per la stringa vuota, e un’interruzione di linea terminale
     non produce una linea extra:

          >>> b"".split(b'\n'), b"Two lines\n".split(b'\n')
          ([b''], [b'Two lines', b''])
          >>> b"".splitlines(), b"One line\n".splitlines()
          ([], [b'One line'])

 -- Metodo: bytes.swapcase ()
 -- Metodo: bytearray.swapcase ()

     Restituisce una copia della sequenza con tutti i caratteri ASCII
     minuscoli convertiti nei loro corrispondenti caratteri maiuscoli e
     viceversa.

     Ad esempio:

          >>> b'Hello World'.swapcase()
          b'hELLO wORLD'

     I caratteri minuscoli ASCII sono quei valori di byte nella sequenza
     ‘b'abcdefghijklmnopqrstuvwxyz'’.  I caratteri maiuscoli ASCII sono
     quei valori di byte nella sequenza ‘b'ABCDEFGHIJKLMNOPQRSTUVWXYZ'’.

     Unlike *note str.swapcase(): 261e, it is always the case that
     ‘bin.swapcase().swapcase() == bin’ for the binary versions.  Case
     conversions are symmetrical in ASCII, even though that is not
     generally true for arbitrary Unicode code points.

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.title ()
 -- Metodo: bytearray.title ()

     Restituisce una versione in formato «titlecase» della sequenza
     binaria in cui le parole iniziano con un carattere ASCII maiuscolo
     e i rimanenti caratteri sono minuscoli.  I valori di byte senza
     distinzione di maiuscole e minuscole non vengono modificati.

     Ad esempio:

          >>> b'Hello world'.title()
          b'Hello World'

     I caratteri ASCII minuscoli sono quei valori di byte nella sequenza
     ‘b'abcdefghijklmnopqrstuvwxyz'’.  I caratteri ASCII maiuscoli sono
     quei valori di byte nella sequenza ‘b'ABCDEFGHIJKLMNOPQRSTUVWXYZ'’.
     Tutti gli altri valori di byte sono senza distinzione di maiuscole
     e minuscole.

     L’algoritmo utilizza una semplice definizione indipendente dalla
     lingua di una parola come gruppi di lettere consecutive.  La
     definizione funziona in molti contesti, ma ciò significa che gli
     apostrofi nelle contrazioni e nei possessivi formano confini di
     parola, il che potrebbe non essere il risultato desiderato:

          >>> b"they're bill's friends from the UK".title()
          b"They'Re Bill'S Friends From The Uk"

     Una soluzione alternativa per gli apostrofi può essere costruita
     utilizzando espressioni regolari:

          >>> import re
          >>> def titlecase(s):
          ...     return re.sub(rb"[A-Za-z]+('[A-Za-z]+)?",
          ...                   lambda mo: mo.group(0)[0:1].upper() +
          ...                              mo.group(0)[1:].lower(),
          ...                   s)
          ...
          >>> titlecase(b"they're bill's friends.")
          b"They're Bill's Friends."

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.upper ()
 -- Metodo: bytearray.upper ()

     Restituisce una copia della sequenza con tutti i caratteri ASCII
     minuscoli convertiti nei loro corrispondenti caratteri maiuscoli.

     Ad esempio:

          >>> b'Hello World'.upper()
          b'HELLO WORLD'

     I caratteri minuscoli ASCII sono quei valori di byte nella sequenza
     ‘b'abcdefghijklmnopqrstuvwxyz'’.  I caratteri maiuscoli ASCII sono
     quei valori di byte nella sequenza ‘b'ABCDEFGHIJKLMNOPQRSTUVWXYZ'’.

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.

 -- Metodo: bytes.zfill (width, /)
 -- Metodo: bytearray.zfill (width, /)

     Restituisce una copia della sequenza riempita a sinistra con i
     caratteri ASCII ‘b'0'’ per creare una sequenza della lunghezza
     'width'.  Un prefisso di segno principale (‘b'+'’/ ‘b'-'’) viene
     gestito inserendo il padding 'dopo' il carattere del segno anziché
     prima.  Per gli oggetti *note bytes: 192, la sequenza originale
     viene restituita se 'width' è inferiore o uguale a ‘len(seq)’.

     Ad esempio:

          >>> b"42".zfill(5)
          b'00042'
          >>> b"-42".zfill(5)
          b'-0042'

          Nota: La versione di questo metodo per bytearray non opera 'in
          place' - produce sempre un nuovo oggetto, anche se non sono
          state apportate modifiche.


File: python.info,  Node: Formattazione Bytes stile printf,  Next: Memory Views,  Prev: Operazioni su Bytes e Bytearray,  Up: Tipi di sequenze binarie — bytes bytearray memoryview

5.4.10.4 Formattazione Bytes stile ‘printf’
...........................................

     Nota: Le operazioni di formattazione descritte qui mostrano una
     varietà di stranezze che portano a numerosi errori comuni (come la
     visualizzazione errata di tuple e dizionari).  Se il valore da
     stampare potrebbe essere una tupla o un dizionario, racchiudilo in
     una tupla.

Gli oggetti Bytes (‘bytes’/‘bytearray’) hanno un’operazione integrata
unica: l’operatore ‘%’ (modulo).  Questo è anche noto come operatore di
'formattazione' o 'interpolazione' dei bytes.  Dato ‘format % values’
(dove 'format' è un oggetto bytes), le specifiche di conversione ‘%’ in
'format' sono sostituite con uno o più elementi di 'values'.  L’effetto
è simile all’uso della funzione ‘sprintf()’ nel linguaggio C.

Se 'format' richiede un singolo argomento, 'values' può essere un
singolo oggetto non-tuple.  (1)  Altrimenti, 'values' deve essere una
tupla con esattamente il numero di elementi specificati dall’oggetto
bytes di formato, o un singolo oggetto di mappatura (ad esempio, un
dizionario).

Uno specificatore di conversione contiene due o più caratteri e ha i
seguenti componenti, che devono apparire in questo ordine:

  1. Il carattere ‘'%'’, che segna l’inizio dello specificatore.

  2. Chiave di mappatura (opzionale), costituita da una sequenza tra
     parentesi di caratteri (ad esempio, ‘(somename)’).

  3. Flag di conversione (opzionali), che influiscono sul risultato di
     alcuni tipi di conversione.

  4. Larghezza minima del campo (opzionale).  Se specificata come ‘'*'’
     (asterisco), la larghezza effettiva viene letta dal prossimo
     elemento della tupla in 'values', e l’oggetto da convertire viene
     dopo la larghezza minima del campo e la precisione opzionale.

  5. Precisione (opzionale), data come ‘'.'’ (punto) seguita dalla
     precisione.  Se specificata come ‘'*'’ (un asterisco), la
     precisione effettiva viene letta dal prossimo elemento della tupla
     in 'values', e il valore da convertire viene dopo la precisione.

  6. Modificatore di lunghezza (opzionale).

  7. Tipo di conversione.

Quando l’argomento a destra è un dizionario (o un altro tipo di
mappatura), allora i formati nell’oggetto bytes 'devono' includere una
chiave di mappatura tra parentesi in quel dizionario inserita
immediatamente dopo il carattere ‘'%'’.  La chiave di mappatura
seleziona il valore da formattare dalla mappatura.  Ad esempio:

     >>> print(b'%(language)s has %(number)03d quote types.' %
     ...       {b'language': b"Python", b"number": 2})
     b'Python has 002 quote types.'

In questo caso non possono comparire specificatori ‘*’ in un formato
(poiché richiedono un elenco di parametri sequenziale).

I caratteri di flag di conversione sono:

Flag          Significato
              
----------------------------------------------------------------------------------------
              
‘'#'’         La conversione del valore utilizzerà la «forma alternativa» (dove
              definita di seguito).
              
              
‘'0'’         La conversione sarà riempita di zeri per i valori numerici.
              
              
‘'-'’         Il valore convertito è allineato a sinistra (sovrascrive la conversione
              ‘'0'’ se entrambi sono forniti).
              
              
‘' '’         (uno spazio) Uno spazio vuoto dovrebbe essere lasciato prima di un
              numero positivo (o stringa vuota) prodotto da una conversione con
              segno.
              
              
‘'+'’         Un carattere di segno (‘'+'’ o ‘'-'’) precederà la conversione
              (sovrascrive un flag «spazio»).
              

Un modificatore di lunghezza (‘h’, ‘l’, o ‘L’) può essere presente, ma
viene ignorato poiché non è necessario per Python – quindi ad esempio
‘%ld’ è identico a ‘%d’.

I tipi di conversione sono:

Conversione      Significato                                               Note
                                                                           
---------------------------------------------------------------------------------------
                                                                           
‘'d'’            Intero con segno decimale.
                 
                                                                           
‘'i'’            Intero con segno decimale.
                 
                                                                           
‘'o'’            Valore ottale con segno.                                  (1)
                                                                           
                                                                           
‘'u'’            Tipo obsoleto – è identico a ‘'d'’.                       (8)
                                                                           
                                                                           
‘'x'’            Esadecimale con segno (minuscolo).                        (2)
                                                                           
                                                                           
‘'X'’            Esadecimale con segno (maiuscolo).                        (2)
                                                                           
                                                                           
‘'e'’            Floating-point exponential format (lowercase).            (3)
                                                                           
                                                                           
‘'E'’            Floating-point exponential format (uppercase).            (3)
                                                                           
                                                                           
‘'f'’            Floating-point decimal format.                            (3)
                                                                           
                                                                           
‘'F'’            Floating-point decimal format.                            (3)
                                                                           
                                                                           
‘'g'’            Floating-point format.  Uses lowercase exponential        (4)
                 format if exponent is less than -4 or not less than       
                 precision, decimal format otherwise.
                 
                                                                           
‘'G'’            Floating-point format.  Uses uppercase exponential        (4)
                 format if exponent is less than -4 or not less than       
                 precision, decimal format otherwise.
                 
                                                                           
‘'c'’            Byte singolo (accetta oggetti interi o byte singoli).
                 
                                                                           
‘'b'’            Bytes (qualsiasi oggetto che segue il                     (5)
                 *note buffer protocol: 260. o ha                          
                 *note __bytes__(): 7ff.).
                 
                                                                           
‘'s'’            ‘'s'’ è un alias per ‘'b'’ e dovrebbe essere usato solo   (6)
                 per basi di codice Python2/3.                             
                 
                                                                           
‘'a'’            Bytes (converte qualsiasi oggetto Python utilizzando      (5)
                 ‘repr(obj).encode('ascii', 'backslashreplace')’).         
                 
                                                                           
‘'r'’            ‘'r'’ è un alias per ‘'a'’ e dovrebbe essere usato solo   (7)
                 per basi di codice Python2/3.                             
                 
                                                                           
‘'%'’            Nessun argomento viene convertito, il risultato è un
                 carattere ‘'%'’ nel risultato.
                 

Note:

  1. La forma alternativa fa sì che venga inserito un prefisso ottale
     (‘'0o'’) prima della prima cifra.

  2. La forma alternativa fa sì che venga inserito un prefisso ‘'0x'’ o
     ‘'0X'’ (a seconda che sia stato usato il formato ‘'x'’ o ‘'X'’)
     prima della prima cifra.

  3. La forma alternativa fa sì che il risultato contenga sempre un
     punto decimale, anche se non ci sono cifre che seguono.

     La precisione determina il numero di cifre dopo il punto decimale e
     il valore predefinito è 6.

  4. La forma alternativa fa sì che il risultato contenga sempre un
     punto decimale e gli zeri finali non vengono rimossi come
     avverrebbe altrimenti.

     La precisione determina il numero di cifre significative prima e
     dopo il punto decimale e il valore predefinito è 6.

  5. Se la precisione è ‘N’, l’output è troncato a ‘N’ caratteri.

  6. ‘b'%s'’ è deprecato, ma non verrà rimosso durante la serie 3.x.

  7. ‘b'%r'’ è deprecato, ma non verrà rimosso durante la serie 3.x.

  8. Vedi PEP 237(2).

     Nota: La versione di questo metodo per bytearray non opera 'in
     place' - produce sempre un nuovo oggetto, anche se non sono state
     apportate modifiche.

Vedi anche
..........

PEP 461(3) - Aggiunta della formattazione % a bytes e bytearray

Added in version 3.5.

   ---------- Footnotes ----------

   (1) Per formattare solo una tupla, dovresti quindi fornire una tupla
singleton il cui unico elemento è la tupla da formattare.

   (2) https://peps.python.org/pep-0237/

   (3) https://peps.python.org/pep-0461/


File: python.info,  Node: Memory Views,  Prev: Formattazione Bytes stile printf,  Up: Tipi di sequenze binarie — bytes bytearray memoryview

5.4.10.5 Memory Views
.....................

Gli oggetti *note memoryview: 165. permettono al codice Python di
accedere ai dati interni di un oggetto che supporta il *note buffer
protocol: 260. senza copiarli.

 -- Classe: memoryview (object)

          Crea un *note memoryview: 165. che fa riferimento a 'object'.
          'object' deve supportare il buffer protocol.  Gli oggetti
          integrati che supportano il buffer protocol includono *note
          bytes: 192. e *note bytearray: 344.

          Un *note memoryview: 165. ha la nozione di 'elemento', che è
          l’unità di memoria atomica gestita dall”'object' originario.
          Per molti tipi semplici come *note bytes: 192. e *note
          bytearray: 344, un elemento è un byte singolo, ma altri tipi
          come *note array.array: 4bf. possono avere elementi più
          grandi.

          ‘len(view)’ è uguale alla lunghezza di *note tolist: 2662, che
          è la rappresentazione dell’elenco nidificato della vista.  Se
          ‘view.ndim = 1’, questo è uguale al numero di elementi nella
          vista.

          Cambiato nella versione 3.12: Se ‘view.ndim == 0’, ‘len(view)’
          ora solleva *note TypeError: 198. invece di restituire 1.

          L’attributo *note itemsize: 2663. ti fornirà il numero di byte
          in un singolo elemento.

          Un *note memoryview: 165. supporta slicing e indicizzazioni
          per esporre i suoi dati.  Lo slicing monodimensionale
          risulterà in una sotto-vista:

               >>> v = memoryview(b'abcefg')
               >>> v[1]
               98
               >>> v[-1]
               103
               >>> v[1:4]
               <memory at 0x7f3ddc9f4350>
               >>> bytes(v[1:4])
               b'bce'

          Se *note format: 2664. è uno degli specificatori di formato
          nativi del modulo *note struct: db, l’indicizzazione con un
          intero o una tupla di interi è anche supportata e restituisce
          un singolo 'elemento' con il tipo corretto.  Le memoryview
          monodimensionali possono essere indicizzate con un intero o
          una tupla di un intero.  Le memoryview multidimensionali
          possono essere indicizzate con tuple di esattamente 'ndim'
          interi dove 'ndim' è il numero di dimensioni.  Le memoryview
          zero-dimensionali possono essere indicizzate con la tupla
          vuota.

          Ecco un esempio con un formato non-byte:

               >>> import array
               >>> a = array.array('l', [-11111111, 22222222, -33333333, 44444444])
               >>> m = memoryview(a)
               >>> m[0]
               -11111111
               >>> m[-1]
               44444444
               >>> m[::2].tolist()
               [-11111111, -33333333]

          Se l’oggetto sottostante è scrivibile, la memoryview supporta
          l’assegnazione di slice monodimensionale.  Non è permesso il
          ridimensionamento:

               >>> data = bytearray(b'abcefg')
               >>> v = memoryview(data)
               >>> v.readonly
               False
               >>> v[0] = ord(b'z')
               >>> data
               bytearray(b'zbcefg')
               >>> v[1:4] = b'123'
               >>> data
               bytearray(b'z123fg')
               >>> v[2:3] = b'spam'
               Traceback (most recent call last):
                 File "<stdin>", line 1, in <module>
               ValueError: memoryview assignment: lvalue and rvalue have different structures
               >>> v[2:6] = b'spam'
               >>> data
               bytearray(b'z1spam')

          Le memoryview monodimensionali di tipi *note hashable: 825.
          (di sola lettura) con formati “B”, “b” o “c” sono anche
          hashable.  L’hash è definito come ‘hash(m) ==
          hash(m.tobytes())’:

               >>> v = memoryview(b'abcefg')
               >>> hash(v) == hash(b'abcefg')
               True
               >>> hash(v[2:4]) == hash(b'ce')
               True
               >>> hash(v[::-2]) == hash(b'abcefg'[::-2])
               True

          Cambiato nella versione 3.3: Le memoryview monodimensionali
          possono ora essere slice.  Le memoryview monodimensionali con
          formati “B”, “b” o “c” sono ora *note hashable: 825.

          Cambiato nella versione 3.4: memoryview è ora registrato
          automaticamente con *note collections.abc.Sequence: 13cc.

          Cambiato nella versione 3.5: le memoryview possono ora essere
          indicizzate con tuple di interi.

          Cambiato nella versione 3.14: memoryview is now a *note
          generic type: 1a1.

          *note memoryview: 165. ha diversi metodi:

           -- Metodo: __eq__ (exporter)

               Una memoryview e un esportatore PEP 3118(1) sono uguali
               se le loro forme sono equivalenti e se tutti i valori
               corrispondenti sono uguali quando i rispettivi codici di
               formato degli operandi sono interpretati utilizzando la
               sintassi *note struct: db.

               Per il sottoinsieme di stringhe di formato *note struct:
               db. attualmente supportato da *note tolist(): 2662, ‘v’ e
               ‘w’ sono uguali se ‘v.tolist() == w.tolist()’:

                    >>> import array
                    >>> a = array.array('I', [1, 2, 3, 4, 5])
                    >>> b = array.array('d', [1.0, 2.0, 3.0, 4.0, 5.0])
                    >>> c = array.array('b', [5, 3, 1])
                    >>> x = memoryview(a)
                    >>> y = memoryview(b)
                    >>> x == a == y == b
                    True
                    >>> x.tolist() == a.tolist() == y.tolist() == b.tolist()
                    True
                    >>> z = y[::-2]
                    >>> z == c
                    True
                    >>> z.tolist() == c.tolist()
                    True

               Se una delle stringhe di formato non è supportata dal
               modulo *note struct: db, allora gli oggetti saranno
               sempre considerati diversi (anche se le stringhe di
               formato e i contenuti del buffer sono identici):

                    >>> from ctypes import BigEndianStructure, c_long
                    >>> class BEPoint(BigEndianStructure):
                    ...     _fields_ = [("x", c_long), ("y", c_long)]
                    ...
                    >>> point = BEPoint(100, 200)
                    >>> a = memoryview(point)
                    >>> b = memoryview(point)
                    >>> a == point
                    False
                    >>> a == b
                    False

               Note that, as with floating-point numbers, ‘v is w’ does
               'not' imply ‘v == w’ for memoryview objects.

               Cambiato nella versione 3.3: Le versioni precedenti
               confrontavano la memoria grezza senza considerare il
               formato degli elementi e la struttura dell’array logico.

           -- Metodo: tobytes (order='C')

               Restituisce i dati nel buffer come una stringa di byte.
               Questo è equivalente a chiamare il costruttore *note
               bytes: 192. sulla memoryview.

                    >>> m = memoryview(b"abc")
                    >>> m.tobytes()
                    b'abc'
                    >>> bytes(m)
                    b'abc'

               Per gli array non contigui il risultato è uguale alla
               rappresentazione dell’elenco appiattito con tutti gli
               elementi convertiti in byte.  *note tobytes(): 2666.
               supporta tutte le stringhe di formato, comprese quelle
               che non sono nella sintassi del modulo *note struct: db.

               Added in version 3.8: 'order' può essere {“C”, “F”, “A”}.
               Quando 'order' è “C” o “F”, i dati dell’array originale
               sono convertiti in ordine C o Fortran.  Per le viste
               contigue, “A” restituisce una copia esatta della memoria
               fisica.  In particolare, l’ordine Fortran in memoria
               viene preservato.  Per le viste non contigue, i dati sono
               prima convertiti in C. 'order=None' è equivalente a
               'order=”C”'.

           -- Metodo: hex (*, bytes_per_sep=1)

           -- Metodo: hex (sep, bytes_per_sep=1)

               Restituisce un oggetto stringa contenente due cifre
               esadecimali per ogni byte nel buffer.

                    >>> m = memoryview(b"abc")
                    >>> m.hex()
                    '616263'

               Added in version 3.5.

               Cambiato nella versione 3.8: Simile a *note bytes.hex():
               f67, *note memoryview.hex(): f69. supporta ora i
               parametri opzionali 'sep' e 'bytes_per_sep' per inserire
               separatori tra i byte nell’output esadecimale.

           -- Metodo: tolist ()

               Restituisce i dati nel buffer come una lista di elementi.

                    >>> memoryview(b'abc').tolist()
                    [97, 98, 99]
                    >>> import array
                    >>> a = array.array('d', [1.1, 2.2, 3.3])
                    >>> m = memoryview(a)
                    >>> m.tolist()
                    [1.1, 2.2, 3.3]

               Cambiato nella versione 3.3: *note tolist(): 2662.
               supporta ora tutti i formati nativi a singolo carattere
               nella sintassi del modulo *note struct: db. nonché
               rappresentazioni multidimensionali.

           -- Metodo: toreadonly ()

               Restituisce una versione di sola lettura dell’oggetto
               memoryview.  L’oggetto memoryview originale rimane
               invariato.

                    >>> m = memoryview(bytearray(b'abc'))
                    >>> mm = m.toreadonly()
                    >>> mm.tolist()
                    [97, 98, 99]
                    >>> mm[0] = 42
                    Traceback (most recent call last):
                      File "<stdin>", line 1, in <module>
                    TypeError: cannot modify read-only memory
                    >>> m[0] = 43
                    >>> mm.tolist()
                    [43, 98, 99]

               Added in version 3.8.

           -- Metodo: release ()

               Rilascia il buffer sottostante esposto dall’oggetto
               memoryview.  Molti oggetti prendono azioni speciali
               quando una vista è mantenuta su di essi (ad esempio, un
               *note bytearray: 344. temporaneamente vieterebbe il
               ridimensionamento); quindi, chiamare release() è utile
               per rimuovere queste restrizioni (e liberare eventuali
               risorse sospese) il più presto possibile.

               After this method has been called, any further operation
               on the view raises a *note ValueError: 2ec. (except *note
               release(): 13c6. itself which can be called multiple
               times):

                    >>> m = memoryview(b'abc')
                    >>> m.release()
                    >>> m[0]
                    Traceback (most recent call last):
                      File "<stdin>", line 1, in <module>
                    ValueError: operation forbidden on released memoryview object

               Il protocollo di gestione del contesto può essere
               utilizzato per un effetto simile, usando l’istruzione
               ‘with’:

                    >>> with memoryview(b'abc') as m:
                    ...     m[0]
                    ...
                    97
                    >>> m[0]
                    Traceback (most recent call last):
                      File "<stdin>", line 1, in <module>
                    ValueError: operation forbidden on released memoryview object

               Added in version 3.2.

           -- Metodo: cast (format, /)

           -- Metodo: cast (format, shape, /)

               Converte un memoryview in un nuovo formato o forma.
               'shape' di default è ‘[byte_length//new_itemsize]’, il
               che significa che la vista risultante sarà
               unidimensionale.  Il valore restituito è un nuovo
               memoryview, ma il buffer stesso non è copiato.  I cast
               supportati sono 1D -> C-*note contiguous: 2669. e
               C-contiguous -> 1D.

               Il formato di destinazione è limitato a un formato nativo
               a singolo elemento nella sintassi del modulo *note
               struct: db.  Uno dei formati deve essere un formato byte
               (“B”, “b” o “c”).  La lunghezza in byte del risultato
               deve essere uguale alla lunghezza originale.  Nota che
               tutte le lunghezze in byte possono dipendere dal sistema
               operativo.

               Converte 1D/long in 1D/unsigned bytes:

                    >>> import array
                    >>> a = array.array('l', [1,2,3])
                    >>> x = memoryview(a)
                    >>> x.format
                    'l'
                    >>> x.itemsize
                    8
                    >>> len(x)
                    3
                    >>> x.nbytes
                    24
                    >>> y = x.cast('B')
                    >>> y.format
                    'B'
                    >>> y.itemsize
                    1
                    >>> len(y)
                    24
                    >>> y.nbytes
                    24

               Converte 1D/unsigned bytes in 1D/char:

                    >>> b = bytearray(b'zyz')
                    >>> x = memoryview(b)
                    >>> x[0] = b'a'
                    Traceback (most recent call last):
                      ...
                    TypeError: memoryview: invalid type for format 'B'
                    >>> y = x.cast('c')
                    >>> y[0] = b'a'
                    >>> b
                    bytearray(b'ayz')

               Converte 1D/bytes in 3D/ints in 1D/signed char:

                    >>> import struct
                    >>> buf = struct.pack("i"*12, *list(range(12)))
                    >>> x = memoryview(buf)
                    >>> y = x.cast('i', shape=[2,2,3])
                    >>> y.tolist()
                    [[[0, 1, 2], [3, 4, 5]], [[6, 7, 8], [9, 10, 11]]]
                    >>> y.format
                    'i'
                    >>> y.itemsize
                    4
                    >>> len(y)
                    2
                    >>> y.nbytes
                    48
                    >>> z = y.cast('b')
                    >>> z.format
                    'b'
                    >>> z.itemsize
                    1
                    >>> len(z)
                    48
                    >>> z.nbytes
                    48

               Converte 1D/unsigned long in 2D/unsigned long:

                    >>> buf = struct.pack("L"*6, *list(range(6)))
                    >>> x = memoryview(buf)
                    >>> y = x.cast('L', shape=[2,3])
                    >>> len(y)
                    2
                    >>> y.nbytes
                    48
                    >>> y.tolist()
                    [[0, 1, 2], [3, 4, 5]]

               Added in version 3.3.

               Cambiato nella versione 3.5: Il formato di origine non è
               più limitato quando si converte in una vista byte.

           -- Metodo: count (value, /)

               Count the number of occurrences of 'value'.

               Added in version 3.14.

      -- Metodo: index (value, start=0, stop=sys.maxsize, /)

               Return the index of the first occurrence of 'value' (at
               or after index 'start' and before index 'stop').

               Raises a *note ValueError: 2ec. if 'value' cannot be
               found.

               Added in version 3.14.

          Sono disponibili anche diversi attributi di sola lettura:

           -- Attributo: obj

               L’oggetto sottostante del memoryview:

                    >>> b  = bytearray(b'xyz')
                    >>> m = memoryview(b)
                    >>> m.obj is b
                    True

               Added in version 3.3.

           -- Attributo: nbytes

               ‘nbytes == product(shape) * itemsize ==
               len(m.tobytes())’.  Questo è lo spazio in byte che
               l’array utilizzarebbe in una rappresentazione contigua.
               Non necessariamente uguale a ‘len(m)’:

                    >>> import array
                    >>> a = array.array('i', [1,2,3,4,5])
                    >>> m = memoryview(a)
                    >>> len(m)
                    5
                    >>> m.nbytes
                    20
                    >>> y = m[::2]
                    >>> len(y)
                    3
                    >>> y.nbytes
                    12
                    >>> len(y.tobytes())
                    12

               Array multidimensionali:

                    >>> import struct
                    >>> buf = struct.pack("d"*12, *[1.5*x for x in range(12)])
                    >>> x = memoryview(buf)
                    >>> y = x.cast('d', shape=[3,4])
                    >>> y.tolist()
                    [[0.0, 1.5, 3.0, 4.5], [6.0, 7.5, 9.0, 10.5], [12.0, 13.5, 15.0, 16.5]]
                    >>> len(y)
                    3
                    >>> y.nbytes
                    96

               Added in version 3.3.

           -- Attributo: readonly

               Un bool che indica se la memoria è di sola lettura.

           -- Attributo: format

               Una stringa contenente il formato (nello stile del modulo
               *note struct: db.) per ogni elemento nella vista.  Un
               memoryview può essere creato da esportatori con stringhe
               di formato arbitrario, ma alcuni metodi (es.: *note
               tolist(): 2662.) sono limitati ai formati a singolo
               elemento nativi.

               Cambiato nella versione 3.3: Il formato ‘'B'’ viene ora
               gestito secondo la sintassi del modulo struct.  Ciò
               significa che ‘memoryview(b'abc')[0] == b'abc'[0] == 97’.

           -- Attributo: itemsize

               La dimensione in byte di ogni elemento del memoryview:

                    >>> import array, struct
                    >>> m = memoryview(array.array('H', [32000, 32001, 32002]))
                    >>> m.itemsize
                    2
                    >>> m[0]
                    32000
                    >>> struct.calcsize('H') == m.itemsize
                    True

           -- Attributo: ndim

               Un intero che indica quante dimensioni di un array
               multidimensionale la memoria rappresenta.

           -- Attributo: shape

               Una tupla di numeri interi della lunghezza di *note ndim:
               266d. che indica la forma della memoria come un array
               N-dimensionale.

               Cambiato nella versione 3.3: Una tupla vuota invece di
               ‘None’ quando ndim = 0.

           -- Attributo: strides

               Una tupla di numeri interi della lunghezza di *note ndim:
               266d. che indica la dimensione in byte per accedere a
               ogni elemento per ciascuna dimensione dell’array.

               Cambiato nella versione 3.3: Una tupla vuota invece di
               ‘None’ quando ndim = 0.

           -- Attributo: suboffsets

               Usato internamente per array in stile PIL. Il valore è
               solo informativo.

           -- Attributo: c_contiguous

               Un bool che indica se la memoria è C-*note contiguous:
               2669.

               Added in version 3.3.

           -- Attributo: f_contiguous

               Un bool che indica se la memoria è Fortran *note
               contiguous: 2669.

               Added in version 3.3.

           -- Attributo: contiguous

               Un bool che indica se la memoria è *note contiguous:
               2669.

               Added in version 3.3.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3118/


File: python.info,  Node: Tipi di Insiemi — set frozenset,  Next: Tipi di Mapping — dict,  Prev: Tipi di sequenze binarie — bytes bytearray memoryview,  Up: Tipi incorporati

5.4.11 Tipi di Insiemi — ‘set’, ‘frozenset’
-------------------------------------------

Un oggetto 'set' è una collezione non ordinata di oggetti distinti *note
hashable: 825.  Usati comunemente per test di appartenenza, rimozione di
duplicati da una sequenza e operazioni matematiche come intersezione,
unione, differenza e differenza simmetrica.  (Per altri contenitori vedi
le classi integrate *note dict: 183, *note list: 24d. e *note tuple:
614, e il modulo *note collections: 1e.)

Come altre collezioni, gli insiemi supportano ‘x in set’, ‘len(set)’ e
‘for x in set’.  Essendo una collezione non ordinata, gli insiemi non
tengono traccia della posizione degli elementi o dell’ordine di
inserimento.  Di conseguenza, gli insiemi non supportano indicizzazione,
slicing o altro comportamento simile a una sequenza.

There are currently two built-in set types, *note set: 184. and *note
frozenset: 7f3.  The *note set: 184. type is mutable — the contents can
be changed using methods like *note add(): 2326. and *note remove():
2675.  Since it is mutable, it has no hash value and cannot be used as
either a dictionary key or as an element of another set.  The *note
frozenset: 7f3. type is immutable and *note hashable: 825. — its
contents cannot be altered after it is created; it can therefore be used
as a dictionary key or as an element of another set.

Gli insiemi non vuoti (non i frozenset) possono essere creati mettendo
un elenco di elementi separati da virgole tra parentesi graffe, per
esempio: ‘{'jack', 'sjoerd'}’, oltre al costruttore *note set: 184.

I costruttori per entrambe le classi funzionano allo stesso modo:

 -- Classe: set (iterable=(), /)
 -- Classe: frozenset (iterable=(), /)

     Restituisce un nuovo oggetto set o frozenset i cui elementi sono
     presi da 'iterable'.  Gli elementi di un insieme devono essere
     *note hashable: 825.  Per rappresentare insiemi di insiemi, gli
     insiemi interni devono essere oggetti *note frozenset: 7f3.  Se
     'iterable' non è specificato, viene restituito un nuovo insieme
     vuoto.

Gli insiemi possono essere creati in diversi modi:

   * Usa un elenco di elementi separati da virgole tra parentesi graffe:
     ‘{'jack', 'sjoerd'}’

   * Usa una comprensione dell’insieme: ‘{c for c in 'abracadabra' if c
     not in 'abc'}’

   * Usa il costruttore di tipo: ‘set()’, ‘set('foobar')’, ‘set(['a',
     'b', 'foo'])’

Le istanze di *note set: 184. e *note frozenset: 7f3. forniscono le
seguenti operazioni:

 -- Describe: len(s)

     Restituisce il numero di elementi nell’insieme 's' (cardinalità di
     's').

 -- Describe: x in s

     Verifica l’appartenenza di 'x' in 's'.

 -- Describe: x not in s

     Verifica la non appartenenza di 'x' in 's'.

 -- Metodo: frozenset.isdisjoint (other, /)
 -- Metodo: set.isdisjoint (other, /)

     Restituisce ‘True’ se l’insieme non ha elementi in comune con
     'other'.  Gli insiemi sono disgiunti se e solo se la loro
     intersezione è l’insieme vuoto.

 -- Metodo: frozenset.issubset (other, /)
 -- Metodo: set.issubset (other, /)

 -- Describe: set <= other

     Verifica se ogni elemento nell’insieme è in 'other'.

 -- Describe: set < other

     Verifica se l’insieme è un sottoinsieme proprio di 'other', cioè,
     ‘set <= other e set != other’.

 -- Metodo: frozenset.issuperset (other, /)
 -- Metodo: set.issuperset (other, /)

 -- Describe: set >= other

     Verificare se ogni elemento in 'other' è presente nell’insieme.

 -- Describe: set > other

     Verificare se l’insieme è un superinsieme proprio di 'other', cioè
     ‘set >= other and set != other’.

 -- Metodo: frozenset.union (*others)
 -- Metodo: set.union (*others)

 -- Describe: set | other | ...

     Restituire un nuovo insieme con elementi dall’insieme e tutti gli
     altri.

 -- Metodo: frozenset.intersection (*others)
 -- Metodo: set.intersection (*others)

 -- Describe: set & other & ...

     Restituire un nuovo insieme con elementi comuni all’insieme e a
     tutti gli altri.

 -- Metodo: frozenset.difference (*others)
 -- Metodo: set.difference (*others)

 -- Describe: set - other - ...

     Restituire un nuovo insieme con elementi presenti nell’insieme ma
     non negli altri.

 -- Metodo: frozenset.symmetric_difference (other, /)
 -- Metodo: set.symmetric_difference (other, /)

 -- Describe: set ^ other

     Restituire un nuovo insieme con elementi presenti nell’insieme o in
     'other' ma non in entrambi.

 -- Metodo: frozenset.copy ()
 -- Metodo: set.copy ()

     Restituire una copia superficiale dell’insieme.

Note, the non-operator versions of *note union(): 168a, *note
intersection(): 168b, *note difference(): 267c, *note
symmetric_difference(): 267e, *note issubset(): 2678, and *note
issuperset(): 267a. methods will accept any iterable as an argument.  In
contrast, their operator based counterparts require their arguments to
be sets.  This precludes error-prone constructions like ‘set('abc') &
'cbs'’ in favor of the more readable ‘set('abc').intersection('cbs')’.

Sia *note set: 184. che *note frozenset: 7f3. supportano confronti tra
insiemi.  Due insiemi sono uguali se e solo se ogni elemento di ciascun
insieme è contenuto nell’altro (ciascuno è un sottoinsieme dell’altro).
Un insieme è minore di un altro insieme se e solo se il primo insieme è
un sottoinsieme proprio del secondo insieme (è un sottoinsieme, ma non è
uguale).  Un insieme è maggiore di un altro insieme se e solo se il
primo insieme è un superinsieme proprio del secondo insieme (è un
superinsieme, ma non è uguale).

Le istanze di *note set: 184. sono confrontate con le istanze di *note
frozenset: 7f3. basandosi sui loro membri.  Ad esempio, ‘set('abc') ==
frozenset('abc')’ restituisce ‘True’ e anche ‘set('abc') in
set([frozenset('abc')])’.

I confronti di sottoinsieme e uguaglianza non si generalizzano a una
funzione di ordinamento totale.  Ad esempio, due insiemi non vuoti e
disgiunti non sono uguali e non sono sottoinsiemi l’uno dell’altro,
quindi 'tutti' i seguenti restituiscono ‘False’: ‘a<b’, ‘a==b’ o ‘a>b’.

Poiché gli insiemi definiscono solo un ordinamento parziale (relazioni
di sottoinsieme), l’output del metodo *note list.sort(): dca. è
indefinito per le liste di insiemi.

Gli elementi dell’insieme, come le chiavi del dizionario, devono essere
*note hashable: 825.

Le operazioni binarie che mescolano istanze di *note set: 184. con *note
frozenset: 7f3. restituiscono il tipo del primo operando.  Ad esempio:
‘frozenset('ab') | set('bc')’ restituisce un’istanza di *note frozenset:
7f3.

La seguente tabella elenca le operazioni disponibili per *note set: 184.
che non si applicano alle istanze immutabili di *note frozenset: 7f3.:

 -- Metodo: set.update (*others)

 -- Describe: set |= other | ...

     Aggiornare l’insieme, aggiungendo elementi da tutti gli altri.

 -- Metodo: set.intersection_update (*others)

 -- Describe: set &= other & ...

     Aggiornare l’insieme, mantenendo solo gli elementi presenti in esso
     e in tutti gli altri.

 -- Metodo: set.difference_update (*others)

 -- Describe: set -= other | ...

     Aggiornare l’insieme, rimuovendo gli elementi trovati negli altri.

 -- Metodo: set.symmetric_difference_update (other, /)

 -- Describe: set ^= other

     Aggiornare l’insieme, mantenendo solo gli elementi presenti in un
     insieme o nell’altro, ma non in entrambi.

 -- Metodo: set.add (elem, /)

     Aggiungere l’elemento 'elem' all’insieme.

 -- Metodo: set.remove (elem, /)

     Rimuovere l’elemento 'elem' dall’insieme.  Solleva *note KeyError:
     5e7. se 'elem' non è contenuto nell’insieme.

 -- Metodo: set.discard (elem, /)

     Rimuovere l’elemento 'elem' dall’insieme, se presente.

 -- Metodo: set.pop ()

     Rimuovere e restituire un elemento arbitrario dall’insieme.
     Solleva *note KeyError: 5e7. se l’insieme è vuoto.

 -- Metodo: set.clear ()

     Rimuovere tutti gli elementi dall’insieme.

Note, the non-operator versions of the *note update(): 2682, *note
intersection_update(): 168c, *note difference_update(): 2683, and *note
symmetric_difference_update(): 168d. methods will accept any iterable as
an argument.

Note, the 'elem' argument to the *note __contains__(): 15c1, *note
remove(): 2675, and *note discard(): 2684. methods may be a set.  To
support searching for an equivalent frozenset, a temporary one is
created from 'elem'.


File: python.info,  Node: Tipi di Mapping — dict,  Next: Tipi di gestori di contesti,  Prev: Tipi di Insiemi — set frozenset,  Up: Tipi incorporati

5.4.12 Tipi di Mapping — ‘dict’
-------------------------------

Un oggetto *note mapping: 13c3. mappa valori *note hashable: 825. a
oggetti arbitrari.  Le mappature sono oggetti mutabili.  Attualmente
esiste solo un tipo standard di mappatura, il 'dizionario'.  (Per altri
contenitori, vedere le classi incorporate *note list: 24d, *note set:
184. e *note tuple: 614, e il modulo *note collections: 1e.)

Le chiavi di un dizionario sono valori 'quasi' arbitrari.  Valori che
non sono *note hashable: 825, cioè valori che contengono liste,
dizionari o altri tipi mutabili (che sono comparati per valore anziché
per identità dell’oggetto) non possono essere usati come chiavi.  Valori
che sono comparati come uguali (come ‘1’, ‘1.0’ e ‘True’) possono essere
usati in modo intercambiabile per indicizzare la stessa voce del
dizionario.

 -- Classe: dict (**kwargs)

 -- Classe: dict (mapping, /, **kwargs)

 -- Classe: dict (iterable, /, **kwargs)

     Restituire un nuovo dizionario inizializzato da un argomento
     posizionale opzionale e un insieme possibilmente vuoto di argomenti
     chiave-valore.

     I dizionari possono essere creati con diversi metodi:

        * Utilizzare un elenco separato da virgole di coppie ‘chiave:
          valore’ tra parentesi graffe: ‘{'jack': 4098, 'sjoerd': 4127}’
          o ‘{4098: 'jack', 4127: 'sjoerd'}’

        * Usare una comprensione del dizionario: ‘{}’, ‘{x: x ** 2 per x
          in range(10)}’

        * Utilizzare il costruttore di tipi: ‘dict()’, ‘dict([('foo',
          100), ('bar', 200)])’, ‘dict(foo=100, bar=200)’

     If no positional argument is given, an empty dictionary is created.
     If a positional argument is given and it defines a ‘keys()’ method,
     a dictionary is created by calling *note __getitem__(): 588. on the
     argument with each returned key from the method.  Otherwise, the
     positional argument must be an *note iterable: 142f. object.  Each
     item in the iterable must itself be an iterable with exactly two
     elements.  The first element of each item becomes a key in the new
     dictionary, and the second element the corresponding value.  If a
     key occurs more than once, the last value for that key becomes the
     corresponding value in the new dictionary.

     Se vengono forniti argomenti chiave-valore, gli argomenti
     chiave-valore e i loro valori vengono aggiunti al dizionario creato
     dall’argomento posizionale.  Se una chiave aggiunta è già presente,
     il valore dall’argomento chiave-valore sostituisce il valore
     dall’argomento posizionale.

     Dictionaries compare equal if and only if they have the same ‘(key,
     value)’ pairs (regardless of ordering).  Order comparisons (“<”,
     “<=”, “>=”, “>”) raise *note TypeError: 198.  To illustrate
     dictionary creation and equality, the following examples all return
     a dictionary equal to ‘{"one": 1, "two": 2, "three": 3}’:

          >>> a = dict(one=1, two=2, three=3)
          >>> b = {'one': 1, 'two': 2, 'three': 3}
          >>> c = dict(zip(['one', 'two', 'three'], [1, 2, 3]))
          >>> d = dict([('two', 2), ('one', 1), ('three', 3)])
          >>> e = dict({'three': 3, 'one': 1, 'two': 2})
          >>> f = dict({'one': 1, 'three': 3}, two=2)
          >>> a == b == c == d == e == f
          True

     Fornire argomenti chiave-valore come nel primo esempio funziona
     solo per chiavi che sono identificatori Python validi.  Altrimenti,
     è possibile utilizzare qualsiasi chiave valida.

     I dizionari preservano l’ordine di inserimento.  Nota che
     aggiornare una chiave non influenza l’ordine.  Le chiavi aggiunte
     dopo la cancellazione vengono inserite alla fine.

          >>> d = {"one": 1, "two": 2, "three": 3, "four": 4}
          >>> d
          {'one': 1, 'two': 2, 'three': 3, 'four': 4}
          >>> list(d)
          ['one', 'two', 'three', 'four']
          >>> list(d.values())
          [1, 2, 3, 4]
          >>> d["one"] = 42
          >>> d
          {'one': 42, 'two': 2, 'three': 3, 'four': 4}
          >>> del d["two"]
          >>> d["two"] = None
          >>> d
          {'one': 42, 'three': 3, 'four': 4, 'two': None}

     Cambiato nella versione 3.7: L’ordine del dizionario è garantito
     essere l’ordine di inserimento.  Questo comportamento era un
     dettaglio di implementazione di CPython dalla versione 3.6.

     Queste sono le operazioni che i dizionari supportano (e che quindi,
     anche i tipi di mappatura personalizzati dovrebbero supportare):

      -- Describe: list(d)

          Restituire un elenco di tutte le chiavi utilizzate nel
          dizionario 'd'.

      -- Describe: len(d)

          Restituire il numero di voci nel dizionario 'd'.

      -- Describe: d[key]

          Restituire la voce di 'd' con chiave 'key'.  Solleva
          un’eccezione *note KeyError: 5e7. se 'key' non è nella mappa.

          If a subclass of dict defines a method *note __missing__():
          13c5. and 'key' is not present, the ‘d[key]’ operation calls
          that method with the key 'key' as argument.  The ‘d[key]’
          operation then returns or raises whatever is returned or
          raised by the ‘__missing__(key)’ call.  No other operations or
          methods invoke *note __missing__(): 13c5.  If *note
          __missing__(): 13c5. is not defined, *note KeyError: 5e7. is
          raised.  *note __missing__(): 13c5. must be a method; it
          cannot be an instance variable:

               >>> class Counter(dict):
               ...     def __missing__(self, key):
               ...         return 0
               ...
               >>> c = Counter()
               >>> c['red']
               0
               >>> c['red'] += 1
               >>> c['red']
               1

          The example above shows part of the implementation of *note
          collections.Counter: 1299.  A different ‘__missing__()’ method
          is used by *note collections.defaultdict: 13c4.

      -- Describe: d[key] = value

          Impostare ‘d[key]’ su 'value'.

      -- Describe: del d[key]

          Rimuovere ‘d[key]’ da 'd'.  Solleva una *note KeyError: 5e7.
          se 'key' non è nella mappa.

      -- Describe: key in d

          Restituire ‘True’ se 'd' ha una chiave 'key', altrimenti
          ‘False’.

      -- Describe: key not in d

          Equivalente a ‘not key in d’.

      -- Describe: iter(d)

          Restituire un iteratore sulle chiavi del dizionario.  Questo è
          un collegamento a ‘iter(d.keys())’.

      -- Metodo: clear ()

          Rimuovere tutte le voci dal dizionario.

      -- Metodo: copy ()

          Restituisce una copia superficiale del dizionario.

      -- Metodo: classmethod fromkeys (iterable, value=None, /)

          Crea un nuovo dizionario con chiavi da 'iterable' e valori
          impostati su 'value'.

          *note fromkeys(): 24e. è un metodo di classe che restituisce
          un nuovo dizionario.  'value' predefinito è ‘None’.  Tutti i
          valori si riferiscono a una singola istanza, quindi
          generalmente non ha senso che 'value' sia un oggetto mutabile
          come una lista vuota.  Per ottenere valori distinti,
          utilizzare invece una *note dict comprehension: f81.

      -- Metodo: get (key, default=None, /)

          Restituisce il valore per 'key' se 'key' è nel dizionario,
          altrimenti 'default'.  Se 'default' non è fornito, predefinito
          è ‘None’, in modo che questo metodo non sollevi mai una *note
          KeyError: 5e7.

      -- Metodo: items ()

          Restituisce una nuova vista degli elementi del dizionario
          (coppie ‘(key, value)’).  Vedi la *note documentazione degli
          oggetti view: 25f4.

      -- Metodo: keys ()

          Restituisce una nuova vista delle chiavi del dizionario.  Vedi
          la *note documentazione degli oggetti view: 25f4.

      -- Metodo: pop (key, /)

      -- Metodo: pop (key, default, /)

          Se 'key' è nel dizionario, rimuovilo e restituisci il suo
          valore, altrimenti restituisci 'default'.  Se 'default' non è
          fornito e 'key' non è nel dizionario, viene sollevata una
          *note KeyError: 5e7.

      -- Metodo: popitem ()

          Rimuove e restituisce una coppia ‘(key, value)’ dal
          dizionario.  Le coppie sono restituite in ordine LIFO
          (last-in, first-out).

          *note popitem(): 172d. è utile per iterare distruttivamente su
          un dizionario, come spesso utilizzato negli algoritmi di set.
          Se il dizionario è vuoto, chiamare *note popitem(): 172d.
          solleva una *note KeyError: 5e7.

          Cambiato nella versione 3.7: L’ordine LIFO è ora garantito.
          Nelle versioni precedenti, *note popitem(): 172d. avrebbe
          restituito una coppia chiave/valore arbitraria.

      -- Describe: reversed(d)

          Restituisce un iteratore inverso sulle chiavi del dizionario.
          Questo è un collegamento rapido per ‘reversed(d.keys())’.

          Added in version 3.8.

      -- Metodo: setdefault (key, default=None, /)

          Se 'key' è nel dizionario, restituisce il suo valore.  Se non
          lo è, inserisce 'key' con un valore di 'default' e restituisce
          'default'.  'default' predefinito è ‘None’.

      -- Metodo: update (**kwargs)

      -- Metodo: update (mapping, /, **kwargs)

      -- Metodo: update (iterable, /, **kwargs)

          Update the dictionary with the key/value pairs from 'mapping'
          or 'iterable' and 'kwargs', overwriting existing keys.  Return
          ‘None’.

          *note update(): 166c. accepts either another object with a
          ‘keys()’ method (in which case *note __getitem__(): 588. is
          called with every key returned from the method) or an iterable
          of key/value pairs (as tuples or other iterables of length
          two).  If keyword arguments are specified, the dictionary is
          then updated with those key/value pairs: ‘d.update(red=1,
          blue=2)’.

      -- Metodo: values ()

          Restituisce una nuova vista dei valori del dizionario.  Vedi
          la *note documentazione degli oggetti view: 25f4.

          Un confronto di uguaglianza tra una vista ‘dict.values()’ e
          un’altra restituirà sempre ‘False’.  Questo vale anche quando
          si confronta ‘dict.values()’ con se stesso:

               >>> d = {'a': 1}
               >>> d.values() == d.values()
               False

      -- Describe: d | other

          Crea un nuovo dizionario con le chiavi e i valori uniti di 'd'
          e 'other', che devono essere entrambi dizionari.  I valori di
          'other' hanno la priorità quando 'd' e 'other' condividono
          chiavi.

          Added in version 3.9.

      -- Describe: d |= other

          Aggiorna il dizionario 'd' con chiavi e valori da 'other', che
          può essere un *note mapping: 13c3. o un *note iterable: 142f.
          di coppie chiave/valore.  I valori di 'other' hanno la
          priorità quando 'd' e 'other' condividono chiavi.

          Added in version 3.9.

     I dizionari e le viste del dizionario sono reversibili.

          >>> d = {"one": 1, "two": 2, "three": 3, "four": 4}
          >>> d
          {'one': 1, 'two': 2, 'three': 3, 'four': 4}
          >>> list(reversed(d))
          ['four', 'three', 'two', 'one']
          >>> list(reversed(d.values()))
          [4, 3, 2, 1]
          >>> list(reversed(d.items()))
          [('four', 4), ('three', 3), ('two', 2), ('one', 1)]

     Cambiato nella versione 3.8: I dizionari sono ora reversibili.

Vedi anche
..........

*note types.MappingProxyType: 699. può essere utilizzato per creare una
vista di sola lettura di un *note dict: 183.

* Menu:

* Oggetti vista del dizionario::


File: python.info,  Node: Oggetti vista del dizionario,  Up: Tipi di Mapping — dict

5.4.12.1 Oggetti vista del dizionario
.....................................

Gli oggetti restituiti da *note dict.keys(): 9d2, *note dict.values():
9d3. e *note dict.items(): 9d4. sono 'oggetti vista'.  Forniscono una
vista dinamica sulle voci del dizionario, il che significa che quando il
dizionario cambia, la vista riflette questi cambiamenti.

Le viste del dizionario possono essere iterate per restituire i
rispettivi dati e supportano i test di appartenenza:

 -- Describe: len(dictview)

     Restituisce il numero di voci nel dizionario.

 -- Describe: iter(dictview)

     Restituisce un iteratore sulle chiavi, valori o elementi
     (rappresentati come tuple ‘(key, value)’) nel dizionario.

     Le chiavi e i valori sono iterati in ordine di inserimento.  Questo
     permette la creazione di coppie ‘(value, key)’ usando *note zip():
     1a0.: ‘pairs = zip(d.values(), d.keys())’.  Un altro modo per
     creare la stessa lista è ‘pairs = [(v, k) for (k, v) in
     d.items()]’.

     Le viste di iterazione durante l’aggiunta o l’eliminazione di voci
     nel dizionario possono sollevare una *note RuntimeError: 244. o
     fallire nell’iterare su tutte le voci.

     Cambiato nella versione 3.7: L’ordine del dizionario è garantito
     essere l’ordine di inserimento.

 -- Describe: x in dictview

     Restituisce ‘True’ se 'x' è nelle chiavi, valori o elementi del
     dizionario sottostante (in quest’ultimo caso, 'x' deve essere una
     tupla ‘(key, value)’).

 -- Describe: reversed(dictview)

     Restituisce un iteratore inverso sulle chiavi, valori o elementi
     del dizionario.  La vista verrà iterata in ordine inverso rispetto
     all’inserimento.

     Cambiato nella versione 3.8: Le viste del dizionario sono ora
     reversibili.

 -- Describe: dictview.mapping

     Restituisce un *note types.MappingProxyType: 699. che incapsula il
     dizionario originale cui si riferisce la vista.

     Added in version 3.10.

Le viste delle chiavi sono simili a insiemi poiché le loro voci sono
uniche e *note hashable: 825.  Anche le viste degli elementi hanno
operazioni simili a insiemi poiché le coppie (key, value) sono uniche e
le chiavi sono hashable.  Se anche tutti i valori in una vista di
elementi sono hashable, allora la vista degli elementi può interoperare
con altri insiemi.  (Le viste dei valori non sono trattate come simili
agli insiemi poiché le voci generalmente non sono uniche.)  Per le viste
simili agli insiemi, sono disponibili tutte le operazioni definite per
la classe base astratta *note collections.abc.Set: 2689. (ad esempio,
‘==’, ‘<’, o ‘^’).  Durante l’uso degli operatori di insiemi, le viste
simili agli insiemi accettano qualsiasi iterabile come l’altro operando,
a differenza degli insiemi che accettano solo insiemi come input.

Un esempio di utilizzo delle viste del dizionario:

     >>> dishes = {'eggs': 2, 'sausage': 1, 'bacon': 1, 'spam': 500}
     >>> keys = dishes.keys()
     >>> values = dishes.values()

     >>> # iteration
     >>> n = 0
     >>> for val in values:
     ...     n += val
     ...
     >>> print(n)
     504

     >>> # keys and values are iterated over in the same order (insertion order)
     >>> list(keys)
     ['eggs', 'sausage', 'bacon', 'spam']
     >>> list(values)
     [2, 1, 1, 500]

     >>> # view objects are dynamic and reflect dict changes
     >>> del dishes['eggs']
     >>> del dishes['sausage']
     >>> list(keys)
     ['bacon', 'spam']

     >>> # set operations
     >>> keys & {'eggs', 'bacon', 'salad'}
     {'bacon'}
     >>> keys ^ {'sausage', 'juice'} == {'juice', 'sausage', 'bacon', 'spam'}
     True
     >>> keys | ['juice', 'juice', 'juice'] == {'bacon', 'spam', 'juice'}
     True

     >>> # get back a read-only proxy for the original dictionary
     >>> values.mapping
     mappingproxy({'bacon': 1, 'spam': 500})
     >>> values.mapping['spam']
     500


File: python.info,  Node: Tipi di gestori di contesti,  Next: Tipi di annotazione di tipo — Alias generico Union,  Prev: Tipi di Mapping — dict,  Up: Tipi incorporati

5.4.13 Tipi di gestori di contesti
----------------------------------

La dichiarazione *note with: 186. di Python supporta il concetto di un
contesto di runtime definito da un gestore di contesto.  Questo è
implementato utilizzando una coppia di metodi che consentono alle classi
definite dall’utente di definire un contesto di runtime che viene
inserito prima che il corpo della dichiarazione venga eseguito ed esce
quando la dichiarazione termina:

 -- Metodo: contextmanager.__enter__ ()

     Entra nel contesto di runtime e restituisce questo oggetto o un
     altro oggetto relativo al contesto di runtime.  Il valore
     restituito da questo metodo è associato all’identificatore nella
     clausola ‘as’ di dichiarazioni *note with: 186. che usano questo
     gestore di contesto.

     Un esempio di un gestore di contesto che restituisce se stesso è un
     *note file object: 13cb.  Gli oggetti file restituiscono se stessi
     da __enter__() per permettere di usare *note open(): 316. come
     espressione di contesto in una dichiarazione *note with: 186.

     Un esempio di un gestore di contesto che restituisce un oggetto
     correlato è quello restituito da *note decimal.localcontext():
     158e.  Questi gestori impostano il contesto decimale attivo su una
     copia del contesto decimale originale e quindi restituiscono la
     copia.  Questo consente di apportare modifiche al contesto decimale
     corrente nel corpo della dichiarazione *note with: 186. senza
     influenzare il codice al di fuori della dichiarazione ‘with’.

 -- Metodo: contextmanager.__exit__ (exc_type, exc_val, exc_tb)

     Esce dal contesto di runtime e restituisce un flag booleano che
     indica se deve essere soppressa un’eccezione che si è verificata.
     Se si è verificata un’eccezione durante l’esecuzione del corpo
     della dichiarazione *note with: 186, gli argomenti contengono il
     tipo di eccezione, il valore e le informazioni di traceback.
     Altrimenti, tutti e tre gli argomenti sono ‘None’.

     Returning a true value from this method will cause the *note with:
     186. statement to suppress the exception and continue execution
     with the statement immediately following the ‘with’ statement.
     Otherwise the exception continues propagating after this method has
     finished executing.

     If this method raises an exception while handling an earlier
     exception from the *note with: 186. block, the new exception is
     raised, and the original exception is stored in its *note
     __context__: 14cf. attribute.

     L’eccezione passata non dovrebbe mai essere riesposta
     esplicitamente - invece, questo metodo dovrebbe restituire un
     valore falso per indicare che il metodo è stato completato con
     successo e non vuole sopprimere l’eccezione sollevata.  Questo
     consente al codice di gestione del contesto di rilevare facilmente
     se un metodo *note __exit__(): 1508. ha effettivamente fallito.

Python definisce diversi gestori di contesto per supportare una facile
sincronizzazione dei thread, la chiusura rapida di file o altri oggetti
e una manipolazione più semplice del contesto di aritmetica decimale
attivo.  I tipi specifici non sono trattati in modo speciale oltre alla
loro implementazione del protocollo di gestione del contesto.  Vedi il
modulo *note contextlib: 27. per alcuni esempi.

I *note generator: 1263.i di Python e il decoratore *note
contextlib.contextmanager: 140a. forniscono un modo conveniente per
implementare questi protocolli.  Se una funzione generatrice è decorata
con il decoratore *note contextlib.contextmanager: 140a, restituirà un
gestore di contesto che implementa i metodi necessari *note __enter__():
268b. e *note __exit__(): 268c, piuttosto che l’iteratore prodotto da
una funzione generatrice non decorata.

Si noti che non esiste uno slot specifico per nessuno di questi metodi
nella struttura dei tipi per gli oggetti Python nell’API Python/C. I
tipi di estensione che desiderano definire questi metodi devono fornirli
come un normale metodo accessibile da Python.  Rispetto al sovraccarico
di impostare il contesto di runtime, il sovraccarico di una singola
ricerca nel dizionario della classe è trascurabile.


File: python.info,  Node: Tipi di annotazione di tipo — Alias generico Union,  Next: Altri Tipi Integrati,  Prev: Tipi di gestori di contesti,  Up: Tipi incorporati

5.4.14 Tipi di annotazione di tipo — Alias generico, Union
----------------------------------------------------------

I tipi core incorporati per *note type annotations: 15c. sono *note
Generic Alias: 8c2. e *note Union: 9c7.

* Menu:

* Tipo Generic Alias::
* Tipo Unione::


File: python.info,  Node: Tipo Generic Alias,  Next: Tipo Unione,  Up: Tipi di annotazione di tipo — Alias generico Union

5.4.14.1 Tipo Generic Alias
...........................

Gli oggetti ‘GenericAlias’ sono generalmente creati tramite *note
subscripting: 23b4. di una classe.  Sono più spesso utilizzati con *note
container classes: 23ba, come *note list: 24d. o *note dict: 183.  Ad
esempio, ‘list[int]’ è un oggetto ‘GenericAlias’ creato facendo
subscripting della classe ‘list’ con l’argomento *note int: 19b.  Gli
oggetti ‘GenericAlias’ sono progettati principalmente per essere usati
con *note type annotations: 15c.

     Nota: Generalmente è possibile fare subscripting di una classe solo
     se la classe implementa il metodo speciale *note
     __class_getitem__(): 944.

Un oggetto ‘GenericAlias’ funge da proxy per un *note generic type: 1a1,
implementando 'parameterized generics'.

Per una container class, l’argomento o gli argomenti forniti a un *note
subscription: 23b4. della classe possono indicare il tipo o i tipi degli
elementi che un oggetto contiene.  Ad esempio, ‘set[bytes]’ può essere
utilizzato nelle type annotations per indicare un *note set: 184. in cui
tutti gli elementi sono di tipo *note bytes: 192.

Per una classe che definisce *note __class_getitem__(): 944. ma non è un
container, l’argomento o gli argomenti forniti a un subscription della
classe spesso indicheranno il tipo di ritorno di uno o più metodi
definiti su un oggetto.  Ad esempio, *note regular expressions: be. può
essere utilizzato sia sul tipo di dato *note str: 169. che sul tipo di
dato *note bytes: 192.:

   * Se ‘x = re.search('foo', 'foo')’, ‘x’ sarà un oggetto *note
     re.Match: 118a. dove i valori di ritorno di ‘x.group(0)’ e ‘x[0]’
     saranno entrambi di tipo *note str: 169.  Possiamo rappresentare
     questo tipo di oggetto nelle type annotations con il ‘GenericAlias’
     ‘re.Match[str]’.

   * Se ‘y = re.search(b'bar', b'bar')’, (nota il ‘b’ per *note bytes:
     192.), ‘y’ sarà anch’esso un’istanza di ‘re.Match’, ma i valori di
     ritorno di ‘y.group(0)’ e ‘y[0]’ saranno entrambi di tipo *note
     bytes: 192.  Nelle type annotations, rappresenteremmo questa
     varietà di oggetti *note re.Match: 118a. con ‘re.Match[bytes]’.

Gli oggetti ‘GenericAlias’ sono istanze della classe *note
types.GenericAlias: 9ee, che può essere utilizzata anche per creare
direttamente oggetti ‘GenericAlias’.

 -- Describe: T[X, Y, ...]

     Crea un ‘GenericAlias’ che rappresenta un tipo ‘T’ parametrizzato
     dai tipi 'X', 'Y' e altro a seconda del ‘T’ utilizzato.  Ad
     esempio, una funzione che si aspetta una *note list: 24d.
     contenente elementi di tipo *note float: 196.:

          def average(values: list[float]) -> float:
              return sum(values) / len(values)

     Un altro esempio per gli oggetti *note mapping: 13c3, utilizzando
     un *note dict: 183, che è un tipo generico che si aspetta due
     parametri di tipo che rappresentano il tipo delle chiavi e il tipo
     dei valori.  In questo esempio, la funzione si aspetta un ‘dict’
     con chiavi di tipo *note str: 169. e valori di tipo *note int:
     19b.:

          def send_post_request(url: str, body: dict[str, int]) -> None:
              ...

Le funzioni incorporate *note isinstance(): 2ad. e *note issubclass():
9c6. non accettano tipi ‘GenericAlias’ come secondo argomento:

     >>> isinstance([1, 2], list[str])
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: isinstance() argument 2 cannot be a parameterized generic

Il runtime Python non impone *note type annotations: 15c.  Questo si
estende ai tipi generici e ai loro parametri di tipo.  Quando si crea un
oggetto container da un ‘GenericAlias’, gli elementi nel container non
vengono verificati in base al loro tipo.  Ad esempio, il seguente codice
è sconsigliato, ma verrà eseguito senza errori:

     >>> t = list[str]
     >>> t([1, 2, 3])
     [1, 2, 3]

Inoltre, i generici parametrizzati eliminano i parametri di tipo durante
la creazione dell’oggetto:

     >>> t = list[str]
     >>> type(t)
     <class 'types.GenericAlias'>

     >>> l = t()
     >>> type(l)
     <class 'list'>

Chiamare *note repr(): 1c1. o *note str(): 169. su un generico mostra il
tipo parametrizzato:

     >>> repr(list[int])
     'list[int]'

     >>> str(list[int])
     'list[int]'

Il metodo *note __getitem__(): 588. dei container generici solleverà
un’eccezione per impedire errori come ‘dict[str][str]’:

     >>> dict[str][str]
     Traceback (most recent call last):
       ...
     TypeError: dict[str] is not a generic class

Tuttavia, tali espressioni sono valide quando vengono utilizzate le
*note type variables: 23af.  L’indice deve avere tanti elementi quanti
sono gli item delle variabili di tipo nell’oggetto ‘GenericAlias’ *note
__args__: 268f.:

     >>> from typing import TypeVar
     >>> Y = TypeVar('Y')
     >>> dict[str, Y][int]
     dict[str, int]

* Menu:

* Classi Generiche Standard::
* Attributi Speciali per oggetti GenericAlias::


File: python.info,  Node: Classi Generiche Standard,  Next: Attributi Speciali per oggetti GenericAlias,  Up: Tipo Generic Alias

5.4.14.2 Classi Generiche Standard
..................................

Le seguenti classi della libreria standard supportano i generici
parametrizzati.  Questa lista non è esaustiva.

   * *note tuple: 614.

   * *note list: 24d.

   * *note dict: 183.

   * *note set: 184.

   * *note frozenset: 7f3.

   * *note type: f46.

   * *note asyncio.Future: dc8.

   * *note asyncio.Task: 1c7.

   * *note collections.deque: 7f5.

   * *note collections.defaultdict: 13c4.

   * *note collections.OrderedDict: 7f4.

   * *note collections.Counter: 1299.

   * *note collections.ChainMap: e18.

   * *note collections.abc.Awaitable: fde.

   * *note collections.abc.Coroutine: fdf.

   * *note collections.abc.AsyncIterable: fe1.

   * *note collections.abc.AsyncIterator: fe0.

   * *note collections.abc.AsyncGenerator: e89.

   * *note collections.abc.Iterable: 2691.

   * *note collections.abc.Iterator: 2692.

   * *note collections.abc.Generator: fdd.

   * *note collections.abc.Reversible: e87.

   * *note collections.abc.Container: 2693.

   * *note collections.abc.Collection: e86.

   * *note collections.abc.Callable: 9ed.

   * *note collections.abc.Set: 2689.

   * *note collections.abc.MutableSet: 2694.

   * *note collections.abc.Mapping: ac9.

   * *note collections.abc.MutableMapping: 12b4.

   * *note collections.abc.Sequence: 13cc.

   * *note collections.abc.MutableSequence: 4c0.

   * *note collections.abc.ByteString: 342.

   * *note collections.abc.MappingView: 2695.

   * *note collections.abc.KeysView: 2696.

   * *note collections.abc.ItemsView: 2697.

   * *note collections.abc.ValuesView: 2698.

   * *note contextlib.AbstractContextManager: e8c.

   * *note contextlib.AbstractAsyncContextManager: d22.

   * *note dataclasses.Field: 1943.

   * *note functools.cached_property: 764.

   * *note functools.partialmethod: 218.

   * *note os.PathLike: e4d.

   * *note queue.LifoQueue: 2699.

   * *note queue.Queue: 159c.

   * *note queue.PriorityQueue: 269a.

   * *note queue.SimpleQueue: d63.

   * *note re.Pattern: 1189.

   * *note re.Match: 118a.

   * *note shelve.BsdDbShelf: 269b.

   * *note shelve.DbfilenameShelf: 269c.

   * *note shelve.Shelf: 119d.

   * *note types.MappingProxyType: 699.

   * *note weakref.WeakKeyDictionary: 1911.

   * *note weakref.WeakMethod: 11f1.

   * *note weakref.WeakSet: 7f6.

   * *note weakref.WeakValueDictionary: 1912.


File: python.info,  Node: Attributi Speciali per oggetti GenericAlias,  Prev: Classi Generiche Standard,  Up: Tipo Generic Alias

5.4.14.3 Attributi Speciali per oggetti ‘GenericAlias’
......................................................

Tutti i generici parametrici implementano attributi speciali di sola
lettura.

 -- Attributo: genericalias.__origin__

     Questo attributo punta alla classe generica non parametrizzata:

          >>> list[int].__origin__
          <class 'list'>

 -- Attributo: genericalias.__args__

     Questo attributo è una *note tuple: 614. (possibilmente di
     lunghezza 1) di tipi generici passati al metodo originale *note
     __class_getitem__(): 944. della classe generica:

          >>> dict[str, list[int]].__args__
          (<class 'str'>, list[int])

 -- Attributo: genericalias.__parameters__

     Questo attributo è una tupla calcolata pigramente (possibilmente
     vuota) di variabili di tipo uniche trovate in ‘__args__’:

          >>> from typing import TypeVar

          >>> T = TypeVar('T')
          >>> list[T].__parameters__
          (~T,)

          Nota: Un oggetto ‘GenericAlias’ con parametri *note
          typing.ParamSpec: 488. potrebbe non avere ‘__parameters__’
          corretti dopo la sostituzione perché *note typing.ParamSpec:
          488. è destinato principalmente al controllo statico dei tipi.

 -- Attributo: genericalias.__unpacked__

     Un booleano che è vero se l’alias è stato espanso usando
     l’operatore ‘*’ (vedere *note TypeVarTuple: 489.).

     Added in version 3.11.

Vedi anche
..........

PEP 484(1) - Suggerimenti di Tipo

     Introduzione al framework di Python per le annotazioni di tipo.

PEP 585(2) - Indicazione di Tipo Generica nelle Collezioni Standard

     Introduzione alla capacità di parametrizzare nativamente le classi
     della libreria standard, a condizione che implementino il metodo
     speciale di classe *note __class_getitem__(): 944.

*note Generics: 23af, *note user-defined generics: 6f7. e *note typing.Generic: 179e.

     Documentazione su come implementare classi generiche che possono
     essere parametrizzate in fase di esecuzione e comprese dai
     controllori di tipo statico.

Added in version 3.9.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0585/


File: python.info,  Node: Tipo Unione,  Prev: Tipo Generic Alias,  Up: Tipi di annotazione di tipo — Alias generico Union

5.4.14.4 Tipo Unione
....................

A union object holds the value of the ‘|’ (bitwise or) operation on
multiple *note type objects: 25be.  These types are intended primarily
for *note type annotations: 15c.  The union type expression enables
cleaner type hinting syntax compared to subscripting *note typing.Union:
2a8.

 -- Describe: X | Y | ...

     Definisce un oggetto unione che contiene i tipi 'X', 'Y', e così
     via.  ‘X | Y’ significa X o Y. È equivalente a ‘typing.Union[X,
     Y]’.  Ad esempio, la seguente funzione si aspetta un argomento di
     tipo *note int: 19b. o *note float: 196.:

          def square(number: int | float) -> int | float:
              return number ** 2

          Nota: L’operando ‘|’ non può essere utilizzato in fase di
          esecuzione per definire unioni dove uno o più membri sono un
          riferimento in avanti.  Ad esempio, ‘int | "Foo"’, dove
          ‘"Foo"’ è un riferimento a una classe non ancora definita,
          fallirà in fase di esecuzione.  Per le unioni che includono
          riferimenti in avanti, presentare l’intera espressione come
          una stringa, ad esempio ‘"int | Foo"’.

 -- Describe: union_object == other

     Gli oggetti unione possono essere testati per uguaglianza con altri
     oggetti unione.  Dettagli:

        * Le unioni di unioni sono appiattite:

               (int | str) | float == int | str | float

        * I tipi ridondanti sono rimossi:

               int | str | int == int | str

        * Quando si confrontano le unioni, l’ordine è ignorato:

               int | str == str | int

        * It creates instances of *note typing.Union: 2a8.:

               int | str == typing.Union[int, str]
               type(int | str) is typing.Union

        * I tipi opzionali possono essere scritti come un’unione con
          ‘None’:

               str | None == typing.Optional[str]

 -- Describe: isinstance(obj, union_object)

 -- Describe: issubclass(obj, union_object)

     Anche le chiamate a *note isinstance(): 2ad. e *note issubclass():
     9c6. sono supportate con un oggetto unione:

          >>> isinstance("", int | str)
          True

     Tuttavia, *note generici parametrici: 8c2. negli oggetti unione non
     possono essere verificati:

          >>> isinstance(1, int | list[int])  # short-circuit evaluation
          True
          >>> isinstance([1], int | list[int])
          Traceback (most recent call last):
            ...
          TypeError: isinstance() argument 2 cannot be a parameterized generic

The user-exposed type for the union object can be accessed from *note
typing.Union: 2a8. and used for *note isinstance(): 2ad. checks:

     >>> import typing
     >>> isinstance(int | str, typing.Union)
     True
     >>> typing.Union()
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: cannot create 'typing.Union' instances

     Nota: Il metodo ‘__or__()’ per gli oggetti di tipo è stato aggiunto
     per supportare la sintassi ‘X | Y’.  Se una metaclasse implementa
     ‘__or__()’, l’Unione può sovrascriverlo:

          >>> class M(type):
          ...     def __or__(self, other):
          ...         return "Hello"
          ...
          >>> class C(metaclass=M):
          ...     pass
          ...
          >>> C | int
          'Hello'
          >>> int | C
          int | C

Vedi anche
..........

PEP 604(1) – PEP che propone la sintassi ‘X | Y’ e il tipo Unione.

Added in version 3.10.

Cambiato nella versione 3.14: Union objects are now instances of *note
typing.Union: 2a8.  Previously, they were instances of *note
types.UnionType: 2a7, which remains an alias for *note typing.Union:
2a8.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0604/


File: python.info,  Node: Altri Tipi Integrati,  Next: Attributi Speciali,  Prev: Tipi di annotazione di tipo — Alias generico Union,  Up: Tipi incorporati

5.4.15 Altri Tipi Integrati
---------------------------

L’interprete supporta diversi altri tipi di oggetti.  La maggior parte
di questi supporta solo una o due operazioni.

* Menu:

* Moduli: Moduli<2>.
* Classi e Istanze di Classe::
* Funzioni::
* Metodi::
* Oggetti Codice::
* Oggetti Tipo::
* L’Oggetto Null::
* L’Oggetto Ellipsis::
* L’Oggetto NotImplemented::
* Oggetti Interni::


File: python.info,  Node: Moduli<2>,  Next: Classi e Istanze di Classe,  Up: Altri Tipi Integrati

5.4.15.1 Moduli
...............

L’unica operazione speciale su un modulo è l’accesso agli attributi:
‘m.name’, dove 'm' è un modulo e 'name' accede a un nome definito nella
tabella dei simboli di 'm'.  Gli attributi del modulo possono essere
assegnati.  (Nota che l’istruzione *note import: 7f9. non è,
strettamente parlando, un’operazione su un oggetto modulo; ‘import foo’
non richiede che esista un oggetto modulo chiamato 'foo', ma richiede
una 'definizione' (esterna) per un modulo denominato 'foo' da qualche
parte.)

Un attributo speciale di ogni modulo è *note __dict__: 77e.  Questo è il
dizionario contenente la tabella dei simboli del modulo.  La modifica di
questo dizionario cambierà effettivamente la tabella dei simboli del
modulo, ma l’assegnazione diretta all’attributo *note __dict__: 77e. non
è possibile (puoi scrivere ‘m.__dict__['a'] = 1’, che definisce ‘m.a’
come ‘1’, ma non puoi scrivere ‘m.__dict__ = {}’).  Modificare
direttamente *note __dict__: 77e. non è consigliato.

I moduli integrati nell’interprete sono scritti così: ‘<module 'sys'
(built-in)>’.  Se caricati da un file, sono scritti come ‘<module 'os'
from '/usr/local/lib/pythonX.Y/os.pyc'>’.


File: python.info,  Node: Classi e Istanze di Classe,  Next: Funzioni,  Prev: Moduli<2>,  Up: Altri Tipi Integrati

5.4.15.2 Classi e Istanze di Classe
...................................

Vedi *note Objects, values and types: 2315. e *note Class definitions:
14df. per questi.


File: python.info,  Node: Funzioni,  Next: Metodi,  Prev: Classi e Istanze di Classe,  Up: Altri Tipi Integrati

5.4.15.3 Funzioni
.................

Gli oggetti funzione sono creati dalle definizioni di funzione.  L’unica
operazione su un oggetto funzione è chiamarlo: ‘func(lista-argomenti)’.

Esistono realmente due tipi di oggetti funzione: funzioni integrate e
funzioni definite dall’utente.  Entrambi supportano la stessa operazione
(chiamare la funzione), ma l’implementazione è diversa, da cui i diversi
tipi di oggetti.

Vedi *note Function definitions: 2002. per ulteriori informazioni.


File: python.info,  Node: Metodi,  Next: Oggetti Codice,  Prev: Funzioni,  Up: Altri Tipi Integrati

5.4.15.4 Metodi
...............

Methods are functions that are called using the attribute notation.
There are two flavors: *note built-in methods: 2341. (such as *note
append(): 8dd. on lists) and *note class instance method: 2091.
Built-in methods are described with the types that support them.

Se accedi a un metodo (una funzione definita in uno spazio dei nomi di
una classe) tramite un’istanza, ottieni un oggetto speciale: un oggetto
'metodo vincolato' (anche chiamato *note metodo istanza: 2091.).  Quando
viene chiamato, aggiungerà l’argomento ‘self’ all’elenco degli
argomenti.  I metodi vincolati hanno due attributi speciali di sola
lettura: *note m.__self__: 15d0. è l’oggetto su cui il metodo opera, e
*note m.__func__: 1504. è la funzione che implementa il metodo.
Chiamare ‘m(arg-1, arg-2, ..., arg-n)’ è completamente equivalente a
chiamare ‘m.__func__(m.__self__, arg-1, arg-2, ..., arg-n)’.

Come *note oggetti funzione: 59c, gli oggetti metodo vincolati
supportano l’acquisizione di attributi arbitrari.  Tuttavia, poiché gli
attributi del metodo sono effettivamente memorizzati sull’oggetto
funzione sottostante (*note method.__func__: 1504.), impostare attributi
del metodo sui metodi vincolati non è consentito.  Il tentativo di
impostare un attributo su un metodo provoca il sollevamento di
un’eccezione *note AttributeError: 5f0.  Per impostare un attributo del
metodo, devi esplicitamente impostarlo sull’oggetto funzione
sottostante:

     >>> class C:
     ...     def method(self):
     ...         pass
     ...
     >>> c = C()
     >>> c.method.whoami = 'my name is method'  # can't set on the method
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     AttributeError: 'method' object has no attribute 'whoami'
     >>> c.method.__func__.whoami = 'my name is method'
     >>> c.method.whoami
     'my name is method'

Vedi *note Instance methods: 2091. per ulteriori informazioni.


File: python.info,  Node: Oggetti Codice,  Next: Oggetti Tipo,  Prev: Metodi,  Up: Altri Tipi Integrati

5.4.15.5 Oggetti Codice
.......................

Gli oggetti codice sono utilizzati dall’implementazione per
rappresentare il codice Python «pseudo-compilato» eseguibile come il
corpo di una funzione.  Differiscono dagli oggetti funzione perché non
contengono un riferimento al loro ambiente di esecuzione globale.  Gli
oggetti codice sono restituiti dalla funzione integrata *note compile():
4b2. e possono essere estratti dagli oggetti funzione attraverso il loro
attributo *note __code__: 59d.  Vedi anche il modulo *note code: 1b.

L’accesso a *note __code__: 59d. solleva un *note evento di auditing:
1c56. ‘object.__getattr__’ con argomenti ‘obj’ e ‘"__code__"’.

Un oggetto codice può essere eseguito o valutato passandolo (anziché una
stringa sorgente) alle funzioni integrate *note exec(): 4a3. o *note
eval(): 4a4.

Vedi *note The standard type hierarchy: 2318. per ulteriori
informazioni.


File: python.info,  Node: Oggetti Tipo,  Next: L’Oggetto Null,  Prev: Oggetti Codice,  Up: Altri Tipi Integrati

5.4.15.6 Oggetti Tipo
.....................

Gli oggetti tipo rappresentano i vari tipi di oggetto.  Il tipo di un
oggetto è accessibile tramite la funzione integrata *note type(): f46.
Non ci sono operazioni speciali sui tipi.  Il modulo standard *note
types: 109. definisce nomi per tutti i tipi integrati standard.

I tipi sono scritti così: ‘<class 'int'>’.


File: python.info,  Node: L’Oggetto Null,  Next: L’Oggetto Ellipsis,  Prev: Oggetti Tipo,  Up: Altri Tipi Integrati

5.4.15.7 L’Oggetto Null
.......................

Questo oggetto è restituito da funzioni che non restituiscono
esplicitamente un valore.  Non supporta operazioni speciali.  C’è
esattamente un oggetto null, chiamato ‘None’ (un nome integrato).
‘type(None)()’ produce lo stesso singleton.

È scritto come ‘None’.


File: python.info,  Node: L’Oggetto Ellipsis,  Next: L’Oggetto NotImplemented,  Prev: L’Oggetto Null,  Up: Altri Tipi Integrati

5.4.15.8 L’Oggetto Ellipsis
...........................

This object is commonly used to indicate that something is omitted.  It
supports no special operations.  There is exactly one ellipsis object,
named *note Ellipsis: 2311. (a built-in name).  ‘type(Ellipsis)()’
produces the *note Ellipsis: 2311. singleton.

È scritto come ‘Ellipsis’ o ‘...’.

In typical use, ‘...’ as the ‘Ellipsis’ object appears in a few
different places, for instance:

   - In type annotations, such as *note callable arguments: 26b2. or
     *note tuple elements: 26b3.

   - As the body of a function instead of a *note pass statement: 1fe5.

   - In third-party libraries, such as Numpy's slicing and striding(1).

Python also uses three dots in ways that are not ‘Ellipsis’ objects, for
instance:

   - Doctest’s *note ELLIPSIS: 1675, as a pattern for missing content.

   - The default Python prompt of the *note interactive: 1b5. shell when
     partial input is incomplete.

Lastly, the Python documentation often uses three dots in conventional
English usage to mean omitted content, even in code examples that also
use them as the ‘Ellipsis’.

   ---------- Footnotes ----------

   (1) 
https://numpy.org/doc/stable/user/basics.indexing.html#slicing-and-striding


File: python.info,  Node: L’Oggetto NotImplemented,  Next: Oggetti Interni,  Prev: L’Oggetto Ellipsis,  Up: Altri Tipi Integrati

5.4.15.9 L’Oggetto NotImplemented
.................................

Questo oggetto è restituito da confronti e operazioni binarie quando
questi sono richiesti di operare su tipi che non supportano.  Vedi *note
Comparisons: 24ac. per maggiori informazioni.  C’è esattamente un
oggetto *note NotImplemented: 1a2.  ‘type(NotImplemented)()’ produce
l’istanza singleton.

È scritto come ‘NotImplemented’.


File: python.info,  Node: Oggetti Interni,  Prev: L’Oggetto NotImplemented,  Up: Altri Tipi Integrati

5.4.15.10 Oggetti Interni
.........................

Vedi *note The standard type hierarchy: 2318. per queste informazioni.
Descrive *note stack frame objects: 8f0, *note traceback objects: cee, e
oggetti slice.


File: python.info,  Node: Attributi Speciali,  Next: Limitazione della lunghezza di conversione delle stringhe di interi,  Prev: Altri Tipi Integrati,  Up: Tipi incorporati

5.4.16 Attributi Speciali
-------------------------

L’implementazione aggiunge alcuni attributi speciali di sola lettura a
diversi tipi di oggetti, ove rilevanti.  Alcuni di questi non sono
riportati dalla funzione integrata *note dir(): 845.

 -- Attributo: definition.__name__

     Il nome della classe, funzione, metodo, descrittore o istanza del
     generatore.

 -- Attributo: definition.__qualname__

     Il *note qualified name: 1d0c. della classe, funzione, metodo,
     descrittore o istanza del generatore.

     Added in version 3.3.

 -- Attributo: definition.__module__

     The name of the module in which a class or function was defined.

 -- Attributo: definition.__doc__

     The documentation string of a class or function, or ‘None’ if
     undefined.

 -- Attributo: definition.__type_params__

     The *note type parameters: 5ad. of generic classes, functions, and
     *note type aliases: 684.  For classes and functions that are not
     generic, this will be an empty tuple.

     Added in version 3.12.


File: python.info,  Node: Limitazione della lunghezza di conversione delle stringhe di interi,  Prev: Attributi Speciali,  Up: Tipi incorporati

5.4.17 Limitazione della lunghezza di conversione delle stringhe di interi
--------------------------------------------------------------------------

CPython ha un limite globale per la conversione tra *note int: 19b. e
*note str: 169. per mitigare gli attacchi denial of service.  Questo
limite 'si applica solo' alle basi decimali o ad altre basi numeriche
non potenze di due.  Le conversioni esadecimali, ottali e binarie sono
illimitate.  Il limite può essere configurato.

Il tipo *note int: 19b. in CPython è un numero di lunghezza arbitraria
memorizzato in forma binaria (comunemente noto come «bignum»).  Non
esiste alcun algoritmo che possa convertire una stringa in un intero
binario o un intero binario in una stringa in tempo lineare, 'a meno
che' la base non sia una potenza di 2.  Anche i migliori algoritmi
conosciuti per la base 10 hanno una complessità sub-quadratica.  La
conversione di un valore grande come ‘int('1' * 500_000)’ può richiedere
più di un secondo su una CPU veloce.

Limitare la dimensione della conversione offre un modo pratico per
evitare CVE 2020-10735(1).

Il limite si applica al numero di caratteri numerici nella stringa di
input o output quando sarebbe coinvolto un algoritmo di conversione non
lineare.  Gli underscore e il segno non vengono contati ai fini del
limite.

Quando un’operazione supererebbe il limite, viene sollevata un’eccezione
*note ValueError: 2ec.:

     >>> import sys
     >>> sys.set_int_max_str_digits(4300)  # Illustrative, this is the default.
     >>> _ = int('2' * 5432)
     Traceback (most recent call last):
     ...
     ValueError: Exceeds the limit (4300 digits) for integer string conversion: value has 5432 digits; use sys.set_int_max_str_digits() to increase the limit
     >>> i = int('2' * 4300)
     >>> len(str(i))
     4300
     >>> i_squared = i*i
     >>> len(str(i_squared))
     Traceback (most recent call last):
     ...
     ValueError: Exceeds the limit (4300 digits) for integer string conversion; use sys.set_int_max_str_digits() to increase the limit
     >>> len(hex(i_squared))
     7144
     >>> assert int(hex(i_squared), base=16) == i*i  # Hexadecimal is unlimited.

Il limite predefinito è di 4300 cifre come indicato in *note
sys.int_info.default_max_str_digits: 149b.  Il limite più basso che può
essere configurato è 640 cifre come indicato in *note
sys.int_info.str_digits_check_threshold: 149b.

Verifica:

     >>> import sys
     >>> assert sys.int_info.default_max_str_digits == 4300, sys.int_info
     >>> assert sys.int_info.str_digits_check_threshold == 640, sys.int_info
     >>> msg = int('578966293710682886880994035146873798396722250538762761564'
     ...           '9252925514383915483333812743580549779436104706260696366600'
     ...           '571186405732').to_bytes(53, 'big')
     ...

Added in version 3.11.

* Menu:

* API influenzate::
* Configurazione del limite::
* Configurazione consigliata::

   ---------- Footnotes ----------

   (1) https://www.cve.org/CVERecord?id=CVE-2020-10735


File: python.info,  Node: API influenzate,  Next: Configurazione del limite,  Up: Limitazione della lunghezza di conversione delle stringhe di interi

5.4.17.1 API influenzate
........................

La limitazione si applica solo alle conversioni potenzialmente lente tra
*note int: 19b. e *note str: 169. o *note bytes: 192.:

   * ‘int(string)’ con base predefinita 10.

   * ‘int(string, base)’ per tutte le basi che non sono una potenza di
     2.

   * ‘str(integer)’.

   * ‘repr(integer)’.

   * qualsiasi altra conversione di stringhe in base 10, ad esempio
     ‘f"{integer}"’, ‘"{}".format(integer)’, o ‘b"%d" % integer’.

Le limitazioni non si applicano alle funzioni con un algoritmo lineare:

   * ‘int(string, base)’ con base 2, 4, 8, 16 o 32.

   * *note int.from_bytes(): 1bd1. e *note int.to_bytes(): 1c1a.

   * *note hex(): 14d7, *note oct(): 14d6, *note bin(): 14b0.

   * *note Format Specification Mini-Language: 4fa. per i numeri
     esadecimali, ottali e binari.

   * *note str: 169. a *note float: 196.

   * *note str: 169. a *note decimal.Decimal: 1fe.


File: python.info,  Node: Configurazione del limite,  Next: Configurazione consigliata,  Prev: API influenzate,  Up: Limitazione della lunghezza di conversione delle stringhe di interi

5.4.17.2 Configurazione del limite
..................................

Prima dell’avvio di Python, è possibile utilizzare una variabile
d’ambiente o un flag da linea di comando dell’interprete per configurare
il limite:

   * *note PYTHONINTMAXSTRDIGITS: 1b22, ad es.
     ‘PYTHONINTMAXSTRDIGITS=640 python3’ per impostare il limite a 640 o
     ‘PYTHONINTMAXSTRDIGITS=0 python3’ per disabilitare la limitazione.

   * *note -X int_max_str_digits: 16f, ad es.  ‘python3 -X
     int_max_str_digits=640’

   * *note sys.flags.int_max_str_digits: 26be. contiene il valore di
     *note PYTHONINTMAXSTRDIGITS: 1b22. o *note -X int_max_str_digits:
     16f.  Se sia la variabile d’ambiente che l’opzione ‘-X’ sono
     impostate, l’opzione ‘-X’ ha la precedenza.  Un valore di '-1'
     indica che entrambi non erano impostati, quindi durante
     l’inizializzazione è stato utilizzato un valore di *note
     sys.int_info.default_max_str_digits: 26bf.

Dal codice, puoi ispezionare il limite corrente e impostarne uno nuovo
utilizzando queste API del modulo *note sys: df.:

   * *note sys.get_int_max_str_digits(): 1800. e *note
     sys.set_int_max_str_digits(): 18d9. sono un getter e un setter per
     il limite a livello dell’interprete.  I sotto-interpreti hanno il
     proprio limite.

Informazioni sul predefinito e sul minimo possono essere trovate in
*note sys.int_info: 149b.:

   * *note sys.int_info.default_max_str_digits: 149b. è il limite
     predefinito compilato.

   * *note sys.int_info.str_digits_check_threshold: 149b. è il valore
     minimo accettato per il limite (ad eccezione di 0 che lo
     disabilita).

Added in version 3.11.

     Attenzione: Impostare un limite basso 'può' portare a problemi.
     Sebbene raro, esiste del codice che contiene costanti intere in
     decimale nel loro sorgente che superano la soglia minima.  Una
     conseguenza dell’impostazione del limite è che il codice sorgente
     Python contenente letterali interi decimali più lunghi del limite
     incontrerà un errore durante l’analisi, solitamente all’avvio o al
     momento dell’importazione o anche durante l’installazione - ogni
     volta che un ‘.pyc’ non aggiornato non esiste già per il codice.
     Un workaround per il sorgente che contiene tali costanti grandi è
     convertirle in forma esadecimale ‘0x’ poiché non ha limite.

     Testa accuratamente la tua applicazione se utilizzi un limite
     basso.  Assicurati che i tuoi test vengano eseguiti con il limite
     impostato in anticipo tramite l’ambiente o il flag in modo che si
     applichi durante l’avvio e anche durante qualsiasi passaggio di
     installazione che potrebbe invocare Python per precompilare i
     sorgenti ‘.py’ in file ‘.pyc’.


File: python.info,  Node: Configurazione consigliata,  Prev: Configurazione del limite,  Up: Limitazione della lunghezza di conversione delle stringhe di interi

5.4.17.3 Configurazione consigliata
...................................

Il *note sys.int_info.default_max_str_digits: 26bf. predefinito è
previsto per essere ragionevole per la maggior parte delle applicazioni.
Se la tua applicazione richiede un limite diverso, impostalo dal tuo
punto di ingresso principale utilizzando codice agnostico alla versione
di Python poiché queste API sono state aggiunte in rilasci di patch di
sicurezza in versioni precedenti alla 3.12.

Esempio:

     >>> import sys
     >>> if hasattr(sys, "set_int_max_str_digits"):
     ...     upper_bound = 68000
     ...     lower_bound = 4004
     ...     current_limit = sys.get_int_max_str_digits()
     ...     if current_limit == 0 or current_limit > upper_bound:
     ...         sys.set_int_max_str_digits(upper_bound)
     ...     elif current_limit < lower_bound:
     ...         sys.set_int_max_str_digits(lower_bound)

Se hai bisogno di disabilitarlo completamente, impostalo a ‘0’.


File: python.info,  Node: Built-in Exceptions,  Next: Text Processing Services,  Prev: Tipi incorporati,  Up: The Python Standard Library

5.5 Built-in Exceptions
=======================

In Python, all exceptions must be instances of a class that derives from
*note BaseException: 7d8.  In a *note try: 8f9. statement with an *note
except: 1ab. clause that mentions a particular class, that clause also
handles any exception classes derived from that class (but not exception
classes from which 'it' is derived).  Two exception classes that are not
related via subclassing are never equivalent, even if they have the same
name.

The built-in exceptions listed in this chapter can be generated by the
interpreter or built-in functions.  Except where mentioned, they have an
«associated value» indicating the detailed cause of the error.  This may
be a string or a tuple of several items of information (e.g., an error
code and a string explaining the code).  The associated value is usually
passed as arguments to the exception class’s constructor.

User code can raise built-in exceptions.  This can be used to test an
exception handler or to report an error condition «just like» the
situation in which the interpreter raises the same exception; but beware
that there is nothing to prevent user code from raising an inappropriate
error.

The built-in exception classes can be subclassed to define new
exceptions; programmers are encouraged to derive new exceptions from the
*note Exception: bcf. class or one of its subclasses, and not from *note
BaseException: 7d8.  More information on defining exceptions is
available in the Python Tutorial under *note Eccezioni Definite
dall’Utente: 2066.

* Menu:

* Exception context::
* Inheriting from built-in exceptions::
* Base classes::
* Concrete exceptions::
* Warnings::
* Exception groups::
* Exception hierarchy::


File: python.info,  Node: Exception context,  Next: Inheriting from built-in exceptions,  Up: Built-in Exceptions

5.5.1 Exception context
-----------------------

Three attributes on exception objects provide information about the
context in which the exception was raised:

 -- Attributo: BaseException.__context__
 -- Attributo: BaseException.__cause__
 -- Attributo: BaseException.__suppress_context__

     When raising a new exception while another exception is already
     being handled, the new exception’s ‘__context__’ attribute is
     automatically set to the handled exception.  An exception may be
     handled when an *note except: 1ab. or *note finally: 1b0. clause,
     or a *note with: 186. statement, is used.

     This implicit exception context can be supplemented with an
     explicit cause by using ‘from’ with *note raise: 804.:

          raise new_exc from original_exc

     The expression following *note from: 804. must be an exception or
     ‘None’.  It will be set as ‘__cause__’ on the raised exception.
     Setting ‘__cause__’ also implicitly sets the ‘__suppress_context__’
     attribute to ‘True’, so that using ‘raise new_exc from None’
     effectively replaces the old exception with the new one for display
     purposes (e.g.  converting *note KeyError: 5e7. to *note
     AttributeError: 5f0.), while leaving the old exception available in
     ‘__context__’ for introspection when debugging.

     The default traceback display code shows these chained exceptions
     in addition to the traceback for the exception itself.  An
     explicitly chained exception in ‘__cause__’ is always shown when
     present.  An implicitly chained exception in ‘__context__’ is shown
     only if ‘__cause__’ is *note None: 886. and ‘__suppress_context__’
     is false.

     In either case, the exception itself is always shown after any
     chained exceptions so that the final line of the traceback always
     shows the last exception that was raised.


File: python.info,  Node: Inheriting from built-in exceptions,  Next: Base classes,  Prev: Exception context,  Up: Built-in Exceptions

5.5.2 Inheriting from built-in exceptions
-----------------------------------------

User code can create subclasses that inherit from an exception type.
It’s recommended to only subclass one exception type at a time to avoid
any possible conflicts between how the bases handle the ‘args’
attribute, as well as due to possible memory layout incompatibilities.

'Dettaglio dell’implementazione di CPython:' Most built-in exceptions
are implemented in C for efficiency, see: Objects/exceptions.c(1).  Some
have custom memory layouts which makes it impossible to create a
subclass that inherits from multiple exception types.  The memory layout
of a type is an implementation detail and might change between Python
versions, leading to new conflicts in the future.  Therefore, it’s
recommended to avoid subclassing multiple exception types altogether.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Objects/exceptions.c


File: python.info,  Node: Base classes,  Next: Concrete exceptions,  Prev: Inheriting from built-in exceptions,  Up: Built-in Exceptions

5.5.3 Base classes
------------------

The following exceptions are used mostly as base classes for other
exceptions.

 -- Eccezione: BaseException

     The base class for all built-in exceptions.  It is not meant to be
     directly inherited by user-defined classes (for that, use *note
     Exception: bcf.).  If *note str(): 169. is called on an instance of
     this class, the representation of the argument(s) to the instance
     are returned, or the empty string when there were no arguments.

      -- Attributo: args

          The tuple of arguments given to the exception constructor.
          Some built-in exceptions (like *note OSError: 2c0.) expect a
          certain number of arguments and assign a special meaning to
          the elements of this tuple, while others are usually called
          only with a single string giving an error message.

      -- Metodo: with_traceback (tb)

          This method sets 'tb' as the new traceback for the exception
          and returns the exception object.  It was more commonly used
          before the exception chaining features of PEP 3134(1) became
          available.  The following example shows how we can convert an
          instance of ‘SomeException’ into an instance of
          ‘OtherException’ while preserving the traceback.  Once raised,
          the current frame is pushed onto the traceback of the
          ‘OtherException’, as would have happened to the traceback of
          the original ‘SomeException’ had we allowed it to propagate to
          the caller.

               try:
                   ...
               except SomeException:
                   tb = sys.exception().__traceback__
                   raise OtherException(...).with_traceback(tb)

      -- Attributo: __traceback__

          A writable field that holds the *note traceback object: cee.
          associated with this exception.  See also: *note The raise
          statement: 804.

      -- Metodo: add_note (note)

          Add the string ‘note’ to the exception’s notes which appear in
          the standard traceback after the exception string.  A *note
          TypeError: 198. is raised if ‘note’ is not a string.

          Added in version 3.11.

      -- Attributo: __notes__

          A list of the notes of this exception, which were added with
          *note add_note(): 7d7.  This attribute is created when *note
          add_note(): 7d7. is called.

          Added in version 3.11.

 -- Eccezione: Exception

     All built-in, non-system-exiting exceptions are derived from this
     class.  All user-defined exceptions should also be derived from
     this class.

 -- Eccezione: ArithmeticError

     The base class for those built-in exceptions that are raised for
     various arithmetic errors: *note OverflowError: a83, *note
     ZeroDivisionError: b41, *note FloatingPointError: 26c9.

 -- Eccezione: BufferError

     Raised when a *note buffer: 260. related operation cannot be
     performed.

 -- Eccezione: LookupError

     The base class for the exceptions that are raised when a key or
     index used on a mapping or sequence is invalid: *note IndexError:
     173c, *note KeyError: 5e7.  This can be raised directly by *note
     codecs.lookup(): b5e.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3134/


File: python.info,  Node: Concrete exceptions,  Next: Warnings,  Prev: Base classes,  Up: Built-in Exceptions

5.5.4 Concrete exceptions
-------------------------

The following exceptions are the exceptions that are usually raised.

 -- Eccezione: AssertionError

     Raised when an *note assert: b62. statement fails.

 -- Eccezione: AttributeError

     Raised when an attribute reference (see *note Attribute references:
     2485.) or assignment fails.  (When an object does not support
     attribute references or attribute assignments at all, *note
     TypeError: 198. is raised.)

     The optional 'name' and 'obj' keyword-only arguments set the
     corresponding attributes:

      -- Attributo: name

          The name of the attribute that was attempted to be accessed.

      -- Attributo: obj

          The object that was accessed for the named attribute.

     Cambiato nella versione 3.10: Added the *note name: 26cb. and *note
     obj: 26cc. attributes.

 -- Eccezione: EOFError

     Raised when the *note input(): 14e0. function hits an end-of-file
     condition (EOF) without reading any data.  (Note: the
     ‘io.IOBase.read()’ and *note io.IOBase.readline(): 1531. methods
     return an empty string when they hit EOF.)

 -- Eccezione: FloatingPointError

     Not currently used.

 -- Eccezione: GeneratorExit

     Raised when a *note generator: 1263. or *note coroutine: 6ba. is
     closed; see *note generator.close(): 177b. and *note
     coroutine.close(): 23fe.  It directly inherits from *note
     BaseException: 7d8. instead of *note Exception: bcf. since it is
     technically not an error.

 -- Eccezione: ImportError

     Raised when the *note import: 7f9. statement has troubles trying to
     load a module.  Also raised when the «from list» in ‘from ...
     import’ has a name that cannot be found.

     The optional 'name' and 'path' keyword-only arguments set the
     corresponding attributes:

      -- Attributo: name

          The name of the module that was attempted to be imported.

      -- Attributo: path

          The path to any file which triggered the exception.

     Cambiato nella versione 3.3: Added the *note name: 26cd. and *note
     path: 26ce. attributes.

 -- Eccezione: ModuleNotFoundError

     A subclass of *note ImportError: 65b. which is raised by *note
     import: 7f9. when a module could not be located.  It is also raised
     when ‘None’ is found in *note sys.modules: 17ce.

     Added in version 3.6.

 -- Eccezione: IndexError

     Raised when a sequence subscript is out of range.  (Slice indices
     are silently truncated to fall in the allowed range; if an index is
     not an integer, *note TypeError: 198. is raised.)

 -- Eccezione: KeyError

     Raised when a mapping (dictionary) key is not found in the set of
     existing keys.

 -- Eccezione: KeyboardInterrupt

     Raised when the user hits the interrupt key (normally ‘Control’-‘C’
     or ‘Delete’).  During execution, a check for interrupts is made
     regularly.  The exception inherits from *note BaseException: 7d8.
     so as to not be accidentally caught by code that catches *note
     Exception: bcf. and thus prevent the interpreter from exiting.

          Nota: Catching a *note KeyboardInterrupt: bc7. requires
          special consideration.  Because it can be raised at
          unpredictable points, it may, in some circumstances, leave the
          running program in an inconsistent state.  It is generally
          best to allow *note KeyboardInterrupt: bc7. to end the program
          as quickly as possible or avoid raising it entirely.  (See
          *note Note on Signal Handlers and Exceptions: 26cf.)

 -- Eccezione: MemoryError

     Raised when an operation runs out of memory but the situation may
     still be rescued (by deleting some objects).  The associated value
     is a string indicating what kind of (internal) operation ran out of
     memory.  Note that because of the underlying memory management
     architecture (C’s ‘malloc()’ function), the interpreter may not
     always be able to completely recover from this situation; it
     nevertheless raises an exception so that a stack traceback can be
     printed, in case a run-away program was the cause.

 -- Eccezione: NameError

     Raised when a local or global name is not found.  This applies only
     to unqualified names.  The associated value is an error message
     that includes the name that could not be found.

     The optional 'name' keyword-only argument sets the attribute:

      -- Attributo: name

          The name of the variable that was attempted to be accessed.

     Cambiato nella versione 3.10: Added the *note name: 26d0.
     attribute.

 -- Eccezione: NotImplementedError

     This exception is derived from *note RuntimeError: 244.  In user
     defined base classes, abstract methods should raise this exception
     when they require derived classes to override the method, or while
     the class is being developed to indicate that the real
     implementation still needs to be added.

          Nota: It should not be used to indicate that an operator or
          method is not meant to be supported at all – in that case
          either leave the operator / method undefined or, if a
          subclass, set it to *note None: 886.

          Attenzione: ‘NotImplementedError’ and ‘NotImplemented’ are not
          interchangeable.  This exception should only be used as
          described above; see *note NotImplemented: 1a2. for details on
          correct usage of the built-in constant.

 -- Eccezione: OSError ([arg])

 -- Eccezione: OSError (errno, strerror[, filename[, winerror[,
          filename2]]])

     This exception is raised when a system function returns a
     system-related error, including I/O failures such as «file not
     found» or «disk full» (not for illegal argument types or other
     incidental errors).

     The second form of the constructor sets the corresponding
     attributes, described below.  The attributes default to *note None:
     886. if not specified.  For backwards compatibility, if three
     arguments are passed, the *note args: 78e. attribute contains only
     a 2-tuple of the first two constructor arguments.

     The constructor often actually returns a subclass of *note OSError:
     2c0, as described in *note OS exceptions: 26d1. below.  The
     particular subclass depends on the final *note errno: 179b. value.
     This behaviour only occurs when constructing *note OSError: 2c0.
     directly or via an alias, and is not inherited when subclassing.

      -- Attributo: errno

          A numeric error code from the C variable ‘errno’.

      -- Attributo: winerror

          Under Windows, this gives you the native Windows error code.
          The *note errno: 179b. attribute is then an approximate
          translation, in POSIX terms, of that native error code.

          Under Windows, if the 'winerror' constructor argument is an
          integer, the *note errno: 179b. attribute is determined from
          the Windows error code, and the 'errno' argument is ignored.
          On other platforms, the 'winerror' argument is ignored, and
          the *note winerror: 26d2. attribute does not exist.

      -- Attributo: strerror

          The corresponding error message, as provided by the operating
          system.  It is formatted by the C functions ‘perror()’ under
          POSIX, and ‘FormatMessage()’ under Windows.

      -- Attributo: filename
      -- Attributo: filename2

          For exceptions that involve a file system path (such as *note
          open(): 316. or *note os.unlink(): 12fd.), *note filename:
          26d4. is the file name passed to the function.  For functions
          that involve two file system paths (such as *note os.rename():
          12f9.), *note filename2: 26d5. corresponds to the second file
          name passed to the function.

     Cambiato nella versione 3.3: *note EnvironmentError: 1256, *note
     IOError: 1255, *note WindowsError: 1257, *note socket.error: 1258,
     *note select.error: 1259. and ‘mmap.error’ have been merged into
     *note OSError: 2c0, and the constructor may return a subclass.

     Cambiato nella versione 3.4: The *note filename: 26d4. attribute is
     now the original file name passed to the function, instead of the
     name encoded to or decoded from the *note filesystem encoding and
     error handler: 75e.  Also, the 'filename2' constructor argument and
     attribute was added.

 -- Eccezione: OverflowError

     Raised when the result of an arithmetic operation is too large to
     be represented.  This cannot occur for integers (which would rather
     raise *note MemoryError: 1786. than give up).  However, for
     historical reasons, OverflowError is sometimes raised for integers
     that are outside a required range.  Because of the lack of
     standardization of floating-point exception handling in C, most
     floating-point operations are not checked.

 -- Eccezione: PythonFinalizationError

     This exception is derived from *note RuntimeError: 244.  It is
     raised when an operation is blocked during interpreter shutdown
     also known as *note Python finalization: 47a.

     Examples of operations which can be blocked with a *note
     PythonFinalizationError: 479. during the Python finalization:

        * Creating a new Python thread.

        * *note Joining: 13ec. a running daemon thread.

        * *note os.fork(): 4b6.

     See also the *note sys.is_finalizing(): c82. function.

     Added in version 3.13: Previously, a plain *note RuntimeError: 244.
     was raised.

     Cambiato nella versione 3.14: *note threading.Thread.join(): 13ec.
     can now raise this exception.

 -- Eccezione: RecursionError

     This exception is derived from *note RuntimeError: 244.  It is
     raised when the interpreter detects that the maximum recursion
     depth (see *note sys.getrecursionlimit(): 6ec.) is exceeded.

     Added in version 3.5: Previously, a plain *note RuntimeError: 244.
     was raised.

 -- Eccezione: ReferenceError

     This exception is raised when a weak reference proxy, created by
     the *note weakref.proxy(): c48. function, is used to access an
     attribute of the referent after it has been garbage collected.  For
     more information on weak references, see the *note weakref: 11a.
     module.

 -- Eccezione: RuntimeError

     Raised when an error is detected that doesn’t fall in any of the
     other categories.  The associated value is a string indicating what
     precisely went wrong.

 -- Eccezione: StopIteration

     Raised by built-in function *note next(): 9da. and an *note
     iterator: 4c9.'s *note __next__(): 14d5. method to signal that
     there are no further items produced by the iterator.

      -- Attributo: value

          The exception object has a single attribute ‘value’, which is
          given as an argument when constructing the exception, and
          defaults to *note None: 886.

     When a *note generator: 1263. or *note coroutine: 6ba. function
     returns, a new *note StopIteration: df7. instance is raised, and
     the value returned by the function is used as the *note value:
     23fa. parameter to the constructor of the exception.

     If a generator code directly or indirectly raises *note
     StopIteration: df7, it is converted into a *note RuntimeError: 244.
     (retaining the *note StopIteration: df7. as the new exception’s
     cause).

     Cambiato nella versione 3.3: Added ‘value’ attribute and the
     ability for generator functions to use it to return a value.

     Cambiato nella versione 3.5: Introduced the RuntimeError
     transformation via ‘from __future__ import generator_stop’, see PEP
     479(1).

     Cambiato nella versione 3.7: Enable PEP 479(2) for all code by
     default: a *note StopIteration: df7. error raised in a generator is
     transformed into a *note RuntimeError: 244.

 -- Eccezione: StopAsyncIteration

     Must be raised by *note __anext__(): 186a. method of an *note
     asynchronous iterator: 4c8. object to stop the iteration.

     Added in version 3.5.

 -- Eccezione: SyntaxError (message, details)

     Raised when the parser encounters a syntax error.  This may occur
     in an *note import: 7f9. statement, in a call to the built-in
     functions *note compile(): 4b2, *note exec(): 4a3, or *note eval():
     4a4, or when reading the initial script or standard input (also
     interactively).

     The *note str(): 169. of the exception instance returns only the
     error message.  Details is a tuple whose members are also available
     as separate attributes.

      -- Attributo: filename

          The name of the file the syntax error occurred in.

      -- Attributo: lineno

          Which line number in the file the error occurred in.  This is
          1-indexed: the first line in the file has a ‘lineno’ of 1.

      -- Attributo: offset

          The column in the line where the error occurred.  This is
          1-indexed: the first character in the line has an ‘offset’ of
          1.

      -- Attributo: text

          The source code text involved in the error.

      -- Attributo: end_lineno

          Which line number in the file the error occurred ends in.
          This is 1-indexed: the first line in the file has a ‘lineno’
          of 1.

      -- Attributo: end_offset

          The column in the end line where the error occurred finishes.
          This is 1-indexed: the first character in the line has an
          ‘offset’ of 1.

     For errors in f-string fields, the message is prefixed by
     «f-string: » and the offsets are offsets in a text constructed from
     the replacement expression.  For example, compiling f’Bad {a b}
     field” results in this args attribute: (“f-string: …”, (“”, 1, 2,
     “(a b)n”, 1, 5)).

     Cambiato nella versione 3.10: Added the *note end_lineno: 26da. and
     *note end_offset: 26db. attributes.

 -- Eccezione: IndentationError

     Base class for syntax errors related to incorrect indentation.
     This is a subclass of *note SyntaxError: 18e.

 -- Eccezione: TabError

     Raised when indentation contains an inconsistent use of tabs and
     spaces.  This is a subclass of *note IndentationError: 9ad.

 -- Eccezione: SystemError

     Raised when the interpreter finds an internal error, but the
     situation does not look so serious to cause it to abandon all hope.
     The associated value is a string indicating what went wrong (in
     low-level terms).  In *note CPython: 906, this could be raised by
     incorrectly using Python’s C API, such as returning a ‘NULL’ value
     without an exception set.

     If you’re confident that this exception wasn’t your fault, or the
     fault of a package you’re using, you should report this to the
     author or maintainer of your Python interpreter.  Be sure to report
     the version of the Python interpreter (‘sys.version’; it is also
     printed at the start of an interactive Python session), the exact
     error message (the exception’s associated value) and if possible
     the source of the program that triggered the error.

 -- Eccezione: SystemExit

     This exception is raised by the *note sys.exit(): 277. function.
     It inherits from *note BaseException: 7d8. instead of *note
     Exception: bcf. so that it is not accidentally caught by code that
     catches *note Exception: bcf.  This allows the exception to
     properly propagate up and cause the interpreter to exit.  When it
     is not handled, the Python interpreter exits; no stack traceback is
     printed.  The constructor accepts the same optional argument passed
     to *note sys.exit(): 277.  If the value is an integer, it specifies
     the system exit status (passed to C’s ‘exit()’ function); if it is
     ‘None’, the exit status is zero; if it has another type (such as a
     string), the object’s value is printed and the exit status is one.

     A call to *note sys.exit(): 277. is translated into an exception so
     that clean-up handlers (*note finally: 1b0. clauses of *note try:
     8f9. statements) can be executed, and so that a debugger can
     execute a script without running the risk of losing control.  The
     *note os._exit(): 26dc. function can be used if it is absolutely
     positively necessary to exit immediately (for example, in the child
     process after a call to *note os.fork(): 4b6.).

      -- Attributo: code

          The exit status or error message that is passed to the
          constructor.  (Defaults to ‘None’.)

 -- Eccezione: TypeError

     Raised when an operation or function is applied to an object of
     inappropriate type.  The associated value is a string giving
     details about the type mismatch.

     This exception may be raised by user code to indicate that an
     attempted operation on an object is not supported, and is not meant
     to be.  If an object is meant to support a given operation but has
     not yet provided an implementation, *note NotImplementedError: 36b.
     is the proper exception to raise.

     Passing arguments of the wrong type (e.g.  passing a *note list:
     24d. when an *note int: 19b. is expected) should result in a *note
     TypeError: 198, but passing arguments with the wrong value (e.g.  a
     number outside expected boundaries) should result in a *note
     ValueError: 2ec.

 -- Eccezione: UnboundLocalError

     Raised when a reference is made to a local variable in a function
     or method, but no value has been bound to that variable.  This is a
     subclass of *note NameError: 452.

 -- Eccezione: UnicodeError

     Raised when a Unicode-related encoding or decoding error occurs.
     It is a subclass of *note ValueError: 2ec.

     *note UnicodeError: 462. has attributes that describe the encoding
     or decoding error.  For example, ‘err.object[err.start:err.end]’
     gives the particular invalid input that the codec failed on.

      -- Attributo: encoding

          The name of the encoding that raised the error.

      -- Attributo: reason

          A string describing the specific codec error.

      -- Attributo: object

          The object the codec was attempting to encode or decode.

      -- Attributo: start

          The first index of invalid data in *note object: c80.

          This value should not be negative as it is interpreted as an
          absolute offset but this constraint is not enforced at
          runtime.

      -- Attributo: end

          The index after the last invalid data in *note object: c80.

          This value should not be negative as it is interpreted as an
          absolute offset but this constraint is not enforced at
          runtime.

 -- Eccezione: UnicodeEncodeError

     Raised when a Unicode-related error occurs during encoding.  It is
     a subclass of *note UnicodeError: 462.

 -- Eccezione: UnicodeDecodeError

     Raised when a Unicode-related error occurs during decoding.  It is
     a subclass of *note UnicodeError: 462.

 -- Eccezione: UnicodeTranslateError

     Raised when a Unicode-related error occurs during translating.  It
     is a subclass of *note UnicodeError: 462.

 -- Eccezione: ValueError

     Raised when an operation or function receives an argument that has
     the right type but an inappropriate value, and the situation is not
     described by a more precise exception such as *note IndexError:
     173c.

 -- Eccezione: ZeroDivisionError

     Raised when the second argument of a division or modulo operation
     is zero.  The associated value is a string indicating the type of
     the operands and the operation.

The following exceptions are kept for compatibility with previous
versions; starting from Python 3.3, they are aliases of *note OSError:
2c0.

 -- Eccezione: EnvironmentError

 -- Eccezione: IOError

 -- Eccezione: WindowsError

     Only available on Windows.

* Menu:

* OS exceptions::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0479/

   (2) https://peps.python.org/pep-0479/


File: python.info,  Node: OS exceptions,  Up: Concrete exceptions

5.5.4.1 OS exceptions
.....................

The following exceptions are subclasses of *note OSError: 2c0, they get
raised depending on the system error code.

 -- Eccezione: BlockingIOError

     Raised when an operation would block on an object (e.g.  socket)
     set for non-blocking operation.  Corresponds to ‘errno’ *note
     EAGAIN: 26e0, *note EALREADY: 26e1, *note EWOULDBLOCK: 26e2. and
     *note EINPROGRESS: 26e3.

     In addition to those of *note OSError: 2c0, *note BlockingIOError:
     235. can have one more attribute:

      -- Attributo: characters_written

          An integer containing the number of 'bytes' written to the
          stream before it blocked.  This attribute is available when
          using the buffered I/O classes from the *note io: 83. module.

 -- Eccezione: ChildProcessError

     Raised when an operation on a child process failed.  Corresponds to
     ‘errno’ *note ECHILD: 26e5.

 -- Eccezione: ConnectionError

     A base class for connection-related issues.

     Subclasses are *note BrokenPipeError: 125e, *note
     ConnectionAbortedError: 125f, *note ConnectionRefusedError: 1260.
     and *note ConnectionResetError: 1261.

 -- Eccezione: BrokenPipeError

     A subclass of *note ConnectionError: 100d, raised when trying to
     write on a pipe while the other end has been closed, or trying to
     write on a socket which has been shutdown for writing.  Corresponds
     to ‘errno’ *note EPIPE: 26e6. and *note ESHUTDOWN: 26e7.

 -- Eccezione: ConnectionAbortedError

     A subclass of *note ConnectionError: 100d, raised when a connection
     attempt is aborted by the peer.  Corresponds to ‘errno’ *note
     ECONNABORTED: 26e8.

 -- Eccezione: ConnectionRefusedError

     A subclass of *note ConnectionError: 100d, raised when a connection
     attempt is refused by the peer.  Corresponds to ‘errno’ *note
     ECONNREFUSED: 26e9.

 -- Eccezione: ConnectionResetError

     A subclass of *note ConnectionError: 100d, raised when a connection
     is reset by the peer.  Corresponds to ‘errno’ *note ECONNRESET:
     26ea.

 -- Eccezione: FileExistsError

     Raised when trying to create a file or directory which already
     exists.  Corresponds to ‘errno’ *note EEXIST: 26eb.

 -- Eccezione: FileNotFoundError

     Raised when a file or directory is requested but doesn’t exist.
     Corresponds to ‘errno’ *note ENOENT: 26ec.

 -- Eccezione: InterruptedError

     Raised when a system call is interrupted by an incoming signal.
     Corresponds to ‘errno’ *note EINTR: f89.

     Cambiato nella versione 3.5: Python now retries system calls when a
     syscall is interrupted by a signal, except if the signal handler
     raises an exception (see PEP 475(1) for the rationale), instead of
     raising *note InterruptedError: f8a.

 -- Eccezione: IsADirectoryError

     Raised when a file operation (such as *note os.remove(): 12f8.) is
     requested on a directory.  Corresponds to ‘errno’ *note EISDIR:
     26ed.

 -- Eccezione: NotADirectoryError

     Raised when a directory operation (such as *note os.listdir():
     1302.) is requested on something which is not a directory.  On most
     POSIX platforms, it may also be raised if an operation attempts to
     open or traverse a non-directory file as if it were a directory.
     Corresponds to ‘errno’ *note ENOTDIR: 26ee.

 -- Eccezione: PermissionError

     Raised when trying to run an operation without the adequate access
     rights - for example filesystem permissions.  Corresponds to
     ‘errno’ *note EACCES: 26ef, *note EPERM: 1b3e, and *note
     ENOTCAPABLE: 1b27.

     Cambiato nella versione 3.11.1: WASI’s *note ENOTCAPABLE: 1b27. is
     now mapped to *note PermissionError: f40.

 -- Eccezione: ProcessLookupError

     Raised when a given process doesn’t exist.  Corresponds to ‘errno’
     *note ESRCH: 26f0.

 -- Eccezione: TimeoutError

     Raised when a system function timed out at the system level.
     Corresponds to ‘errno’ *note ETIMEDOUT: 26f1.

Added in version 3.3: All the above *note OSError: 2c0. subclasses were
added.

Vedi anche
..........

PEP 3151(2) - Reworking the OS and IO exception hierarchy

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0475/

   (2) https://peps.python.org/pep-3151/


File: python.info,  Node: Warnings,  Next: Exception groups,  Prev: Concrete exceptions,  Up: Built-in Exceptions

5.5.5 Warnings
--------------

The following exceptions are used as warning categories; see the *note
Warning Categories: 26f4. documentation for more details.

 -- Eccezione: Warning

     Base class for warning categories.

 -- Eccezione: UserWarning

     Base class for warnings generated by user code.

 -- Eccezione: DeprecationWarning

     Base class for warnings about deprecated features when those
     warnings are intended for other Python developers.

     Ignored by the default warning filters, except in the ‘__main__’
     module ( PEP 565(1)).  Enabling the *note Python Development Mode:
     509. shows this warning.

     The deprecation policy is described in PEP 387(2).

 -- Eccezione: PendingDeprecationWarning

     Base class for warnings about features which are obsolete and
     expected to be deprecated in the future, but are not deprecated at
     the moment.

     This class is rarely used as emitting a warning about a possible
     upcoming deprecation is unusual, and *note DeprecationWarning: 1a3.
     is preferred for already active deprecations.

     Ignored by the default warning filters.  Enabling the *note Python
     Development Mode: 509. shows this warning.

     The deprecation policy is described in PEP 387(3).

 -- Eccezione: SyntaxWarning

     Base class for warnings about dubious syntax.

     This warning is typically emitted when compiling Python source
     code, and usually won’t be reported when running already compiled
     code.

 -- Eccezione: RuntimeWarning

     Base class for warnings about dubious runtime behavior.

 -- Eccezione: FutureWarning

     Base class for warnings about deprecated features when those
     warnings are intended for end users of applications that are
     written in Python.

 -- Eccezione: ImportWarning

     Base class for warnings about probable mistakes in module imports.

     Ignored by the default warning filters.  Enabling the *note Python
     Development Mode: 509. shows this warning.

 -- Eccezione: UnicodeWarning

     Base class for warnings related to Unicode.

 -- Eccezione: EncodingWarning

     Base class for warnings related to encodings.

     See *note Opt-in EncodingWarning: 2129. for details.

     Added in version 3.10.

 -- Eccezione: BytesWarning

     Base class for warnings related to *note bytes: 192. and *note
     bytearray: 344.

 -- Eccezione: ResourceWarning

     Base class for warnings related to resource usage.

     Ignored by the default warning filters.  Enabling the *note Python
     Development Mode: 509. shows this warning.

     Added in version 3.2.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0565/

   (2) https://peps.python.org/pep-0387/

   (3) https://peps.python.org/pep-0387/


File: python.info,  Node: Exception groups,  Next: Exception hierarchy,  Prev: Warnings,  Up: Built-in Exceptions

5.5.6 Exception groups
----------------------

The following are used when it is necessary to raise multiple unrelated
exceptions.  They are part of the exception hierarchy so they can be
handled with *note except: 1ab. like all other exceptions.  In addition,
they are recognised by *note except*: 1ac, which matches their subgroups
based on the types of the contained exceptions.

 -- Eccezione: ExceptionGroup (msg, excs)

 -- Eccezione: BaseExceptionGroup (msg, excs)

     Both of these exception types wrap the exceptions in the sequence
     ‘excs’.  The ‘msg’ parameter must be a string.  The difference
     between the two classes is that *note BaseExceptionGroup: 566.
     extends *note BaseException: 7d8. and it can wrap any exception,
     while *note ExceptionGroup: 4d3. extends *note Exception: bcf. and
     it can only wrap subclasses of *note Exception: bcf.  This design
     is so that ‘except Exception’ catches an *note ExceptionGroup: 4d3.
     but not *note BaseExceptionGroup: 566.

     The *note BaseExceptionGroup: 566. constructor returns an *note
     ExceptionGroup: 4d3. rather than a *note BaseExceptionGroup: 566.
     if all contained exceptions are *note Exception: bcf. instances, so
     it can be used to make the selection automatic.  The *note
     ExceptionGroup: 4d3. constructor, on the other hand, raises a *note
     TypeError: 198. if any contained exception is not an *note
     Exception: bcf. subclass.

      -- Attributo: message

          The ‘msg’ argument to the constructor.  This is a read-only
          attribute.

      -- Attributo: exceptions

          A tuple of the exceptions in the ‘excs’ sequence given to the
          constructor.  This is a read-only attribute.

      -- Metodo: subgroup (condition)

          Returns an exception group that contains only the exceptions
          from the current group that match 'condition', or ‘None’ if
          the result is empty.

          The condition can be an exception type or tuple of exception
          types, in which case each exception is checked for a match
          using the same check that is used in an ‘except’ clause.  The
          condition can also be a callable (other than a type object)
          that accepts an exception as its single argument and returns
          true for the exceptions that should be in the subgroup.

          The nesting structure of the current exception is preserved in
          the result, as are the values of its *note message: 26f9,
          *note __traceback__: 14ce, *note __cause__: 14d0, *note
          __context__: 14cf. and *note __notes__: 26c7. fields.  Empty
          nested groups are omitted from the result.

          The condition is checked for all exceptions in the nested
          exception group, including the top-level and any nested
          exception groups.  If the condition is true for such an
          exception group, it is included in the result in full.

          Added in version 3.13: ‘condition’ can be any callable which
          is not a type object.

      -- Metodo: split (condition)

          Like *note subgroup(): 1a20, but returns the pair ‘(match,
          rest)’ where ‘match’ is ‘subgroup(condition)’ and ‘rest’ is
          the remaining non-matching part.

      -- Metodo: derive (excs)

          Returns an exception group with the same *note message: 26f9,
          but which wraps the exceptions in ‘excs’.

          This method is used by *note subgroup(): 1a20. and *note
          split(): 18c0, which are used in various contexts to break up
          an exception group.  A subclass needs to override it in order
          to make *note subgroup(): 1a20. and *note split(): 18c0.
          return instances of the subclass rather than *note
          ExceptionGroup: 4d3.

          *note subgroup(): 1a20. and *note split(): 18c0. copy the
          *note __traceback__: 14ce, *note __cause__: 14d0, *note
          __context__: 14cf. and *note __notes__: 26c7. fields from the
          original exception group to the one returned by *note
          derive(): 1a1f, so these fields do not need to be updated by
          *note derive(): 1a1f.

               >>> class MyGroup(ExceptionGroup):
               ...     def derive(self, excs):
               ...         return MyGroup(self.message, excs)
               ...
               >>> e = MyGroup("eg", [ValueError(1), TypeError(2)])
               >>> e.add_note("a note")
               >>> e.__context__ = Exception("context")
               >>> e.__cause__ = Exception("cause")
               >>> try:
               ...    raise e
               ... except Exception as e:
               ...    exc = e
               ...
               >>> match, rest = exc.split(ValueError)
               >>> exc, exc.__context__, exc.__cause__, exc.__notes__
               (MyGroup('eg', [ValueError(1), TypeError(2)]), Exception('context'), Exception('cause'), ['a note'])
               >>> match, match.__context__, match.__cause__, match.__notes__
               (MyGroup('eg', [ValueError(1)]), Exception('context'), Exception('cause'), ['a note'])
               >>> rest, rest.__context__, rest.__cause__, rest.__notes__
               (MyGroup('eg', [TypeError(2)]), Exception('context'), Exception('cause'), ['a note'])
               >>> exc.__traceback__ is match.__traceback__ is rest.__traceback__
               True

     Note that *note BaseExceptionGroup: 566. defines *note __new__():
     7a1, so subclasses that need a different constructor signature need
     to override that rather than *note __init__(): 8c0.  For example,
     the following defines an exception group subclass which accepts an
     exit_code and constructs the group’s message from it.

          class Errors(ExceptionGroup):
             def __new__(cls, errors, exit_code):
                self = super().__new__(Errors, f"exit code: {exit_code}", errors)
                self.exit_code = exit_code
                return self

             def derive(self, excs):
                return Errors(excs, self.exit_code)

     Like *note ExceptionGroup: 4d3, any subclass of *note
     BaseExceptionGroup: 566. which is also a subclass of *note
     Exception: bcf. can only wrap instances of *note Exception: bcf.

     Added in version 3.11.


File: python.info,  Node: Exception hierarchy,  Prev: Exception groups,  Up: Built-in Exceptions

5.5.7 Exception hierarchy
-------------------------

The class hierarchy for built-in exceptions is:

     BaseException
      ├── BaseExceptionGroup
      ├── GeneratorExit
      ├── KeyboardInterrupt
      ├── SystemExit
      └── Exception
           ├── ArithmeticError
           │    ├── FloatingPointError
           │    ├── OverflowError
           │    └── ZeroDivisionError
           ├── AssertionError
           ├── AttributeError
           ├── BufferError
           ├── EOFError
           ├── ExceptionGroup [BaseExceptionGroup]
           ├── ImportError
           │    └── ModuleNotFoundError
           ├── LookupError
           │    ├── IndexError
           │    └── KeyError
           ├── MemoryError
           ├── NameError
           │    └── UnboundLocalError
           ├── OSError
           │    ├── BlockingIOError
           │    ├── ChildProcessError
           │    ├── ConnectionError
           │    │    ├── BrokenPipeError
           │    │    ├── ConnectionAbortedError
           │    │    ├── ConnectionRefusedError
           │    │    └── ConnectionResetError
           │    ├── FileExistsError
           │    ├── FileNotFoundError
           │    ├── InterruptedError
           │    ├── IsADirectoryError
           │    ├── NotADirectoryError
           │    ├── PermissionError
           │    ├── ProcessLookupError
           │    └── TimeoutError
           ├── ReferenceError
           ├── RuntimeError
           │    ├── NotImplementedError
           │    ├── PythonFinalizationError
           │    └── RecursionError
           ├── StopAsyncIteration
           ├── StopIteration
           ├── SyntaxError
           │    └── IndentationError
           │         └── TabError
           ├── SystemError
           ├── TypeError
           ├── ValueError
           │    └── UnicodeError
           │         ├── UnicodeDecodeError
           │         ├── UnicodeEncodeError
           │         └── UnicodeTranslateError
           └── Warning
                ├── BytesWarning
                ├── DeprecationWarning
                ├── EncodingWarning
                ├── FutureWarning
                ├── ImportWarning
                ├── PendingDeprecationWarning
                ├── ResourceWarning
                ├── RuntimeWarning
                ├── SyntaxWarning
                ├── UnicodeWarning
                └── UserWarning


File: python.info,  Node: Text Processing Services,  Next: Binary Data Services,  Prev: Built-in Exceptions,  Up: The Python Standard Library

5.6 Text Processing Services
============================

The modules described in this chapter provide a wide range of string
manipulation operations and other text processing services.

The *note codecs: 1c. module described under *note Binary Data Services:
26ff. is also highly relevant to text processing.  In addition, see the
documentation for Python’s built-in string type in *note Tipo Sequenza
di Testo — str: 1fc9.

* Menu:

* string — Common string operations::
* string.templatelib — Support for template string literals: string templatelib — Support for template string literals.
* re — Regular expression operations::
* difflib — Helpers for computing deltas::
* textwrap — Text wrapping and filling::
* unicodedata — Unicode Database::
* stringprep — Internet String Preparation::
* readline — GNU readline interface::
* rlcompleter — Completion function for GNU readline::


File: python.info,  Node: string — Common string operations,  Next: string templatelib — Support for template string literals,  Up: Text Processing Services

5.6.1 ‘string’ — Common string operations
-----------------------------------------

'Source code:' Lib/string/__init__.py(1)

__________________________________________________________________

Vedi anche
..........

*note Tipo Sequenza di Testo — str: 1fc9.

*note Metodi per le Stringhe: 1fca.

* Menu:

* String constants::
* Custom String Formatting::
* Format String Syntax::
* Template strings ($-strings): Template strings $-strings.
* Helper functions::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/string/__init__.py


File: python.info,  Node: String constants,  Next: Custom String Formatting,  Up: string — Common string operations

5.6.1.1 String constants
........................

The constants defined in this module are:

 -- Dati: string.ascii_letters

     The concatenation of the *note ascii_lowercase: 2703. and *note
     ascii_uppercase: 2704. constants described below.  This value is
     not locale-dependent.

 -- Dati: string.ascii_lowercase

     The lowercase letters ‘'abcdefghijklmnopqrstuvwxyz'’.  This value
     is not locale-dependent and will not change.

 -- Dati: string.ascii_uppercase

     The uppercase letters ‘'ABCDEFGHIJKLMNOPQRSTUVWXYZ'’.  This value
     is not locale-dependent and will not change.

 -- Dati: string.digits

     The string ‘'0123456789'’.

 -- Dati: string.hexdigits

     The string ‘'0123456789abcdefABCDEF'’.

 -- Dati: string.octdigits

     The string ‘'01234567'’.

 -- Dati: string.punctuation

     String of ASCII characters which are considered punctuation
     characters in the ‘C’ locale: ‘!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~’.

 -- Dati: string.printable

     String of ASCII characters which are considered printable by
     Python.  This is a combination of *note digits: 2705, *note
     ascii_letters: 14cb, *note punctuation: 2708, and *note whitespace:
     2709.

          Nota: By design, *note string.printable.isprintable(): fda.
          returns *note False: d2d.  In particular, ‘string.printable’
          is not printable in the POSIX sense (see ‘LC_CTYPE(1)’).

 -- Dati: string.whitespace

     A string containing all ASCII characters that are considered
     whitespace.  This includes the characters space, tab, linefeed,
     return, formfeed, and vertical tab.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/locale(5)


File: python.info,  Node: Custom String Formatting,  Next: Format String Syntax,  Prev: String constants,  Up: string — Common string operations

5.6.1.2 Custom String Formatting
................................

The built-in string class provides the ability to do complex variable
substitutions and value formatting via the *note format(): 834. method
described in PEP 3101(1).  The *note Formatter: 10bf. class in the *note
string: d8. module allows you to create and customize your own string
formatting behaviors using the same implementation as the built-in *note
format(): 834. method.

 -- Classe: string.Formatter

     The *note Formatter: 10bf. class has the following public methods:

      -- Metodo: format (format_string, /, *args, **kwargs)

          The primary API method.  It takes a format string and an
          arbitrary set of positional and keyword arguments.  It is just
          a wrapper that calls *note vformat(): 270b.

          Cambiato nella versione 3.7: A format string argument is now
          *note positional-only: c7a.

      -- Metodo: vformat (format_string, args, kwargs)

          This function does the actual work of formatting.  It is
          exposed as a separate function for cases where you want to
          pass in a predefined dictionary of arguments, rather than
          unpacking and repacking the dictionary as individual arguments
          using the ‘*args’ and ‘**kwargs’ syntax.  *note vformat():
          270b. does the work of breaking up the format string into
          character data and replacement fields.  It calls the various
          methods described below.

     In addition, the *note Formatter: 10bf. defines a number of methods
     that are intended to be replaced by subclasses:

      -- Metodo: parse (format_string)

          Loop over the format_string and return an iterable of tuples
          ('literal_text', 'field_name', 'format_spec', 'conversion').
          This is used by *note vformat(): 270b. to break the string
          into either literal text, or replacement fields.

          The values in the tuple conceptually represent a span of
          literal text followed by a single replacement field.  If there
          is no literal text (which can happen if two replacement fields
          occur consecutively), then 'literal_text' will be a
          zero-length string.  If there is no replacement field, then
          the values of 'field_name', 'format_spec' and 'conversion'
          will be ‘None’.  The value of 'field_name' is unmodified and
          auto-numbering of non-numbered positional fields is done by
          *note vformat(): 270b.

      -- Metodo: get_field (field_name, args, kwargs)

          Given 'field_name', convert it to an object to be formatted.
          Auto-numbering of 'field_name' returned from *note parse():
          270c. is done by *note vformat(): 270b. before calling this
          method.  Returns a tuple (obj, used_key).  The default version
          takes strings of the form defined in PEP 3101(2), such as
          «0[name]» or «label.title».  'args' and 'kwargs' are as passed
          in to *note vformat(): 270b.  The return value 'used_key' has
          the same meaning as the 'key' parameter to *note get_value():
          270e.

      -- Metodo: get_value (key, args, kwargs)

          Retrieve a given field value.  The 'key' argument will be
          either an integer or a string.  If it is an integer, it
          represents the index of the positional argument in 'args'; if
          it is a string, then it represents a named argument in
          'kwargs'.

          The 'args' parameter is set to the list of positional
          arguments to *note vformat(): 270b, and the 'kwargs' parameter
          is set to the dictionary of keyword arguments.

          For compound field names, these functions are only called for
          the first component of the field name; subsequent components
          are handled through normal attribute and indexing operations.

          So for example, the field expression “0.name” would cause
          *note get_value(): 270e. to be called with a 'key' argument of
          0.  The ‘name’ attribute will be looked up after *note
          get_value(): 270e. returns by calling the built-in *note
          getattr(): dcc. function.

          If the index or keyword refers to an item that does not exist,
          then an *note IndexError: 173c. or *note KeyError: 5e7. should
          be raised.

      -- Metodo: check_unused_args (used_args, args, kwargs)

          Implement checking for unused arguments if desired.  The
          arguments to this function is the set of all argument keys
          that were actually referred to in the format string (integers
          for positional arguments, and strings for named arguments),
          and a reference to the 'args' and 'kwargs' that was passed to
          vformat.  The set of unused args can be calculated from these
          parameters.  *note check_unused_args(): 270f. is assumed to
          raise an exception if the check fails.

      -- Metodo: format_field (value, format_spec)

          *note format_field(): 2710. simply calls the global *note
          format(): 199. built-in.  The method is provided so that
          subclasses can override it.

      -- Metodo: convert_field (value, conversion)

          Converts the value (returned by *note get_field(): 270d.)
          given a conversion type (as in the tuple returned by the *note
          parse(): 270c. method).  The default version understands “s”
          (str), “r” (repr) and “a” (ascii) conversion types.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3101/

   (2) https://peps.python.org/pep-3101/


File: python.info,  Node: Format String Syntax,  Next: Template strings $-strings,  Prev: Custom String Formatting,  Up: string — Common string operations

5.6.1.3 Format String Syntax
............................

The *note str.format(): 834. method and the *note Formatter: 10bf. class
share the same syntax for format strings (although in the case of *note
Formatter: 10bf, subclasses can define their own format string syntax).
The syntax is related to that of *note formatted string literals: 19a.
and *note template string literals: 17e2, but it is less sophisticated
and, in particular, does not support arbitrary expressions in
interpolations.

Format strings contain «replacement fields» surrounded by curly braces
‘{}’.  Anything that is not contained in braces is considered literal
text, which is copied unchanged to the output.  If you need to include a
brace character in the literal text, it can be escaped by doubling: ‘{{’
and ‘}}’.

The grammar for a replacement field is as follows:

     replacement_field: "{" [*note field_name: 2714.] ["!" *note conversion: 2715.] [":" *note format_spec: 2716.] "}"
     field_name:        *note arg_name: 2717. ("." *note attribute_name: 2718. | "[" *note element_index: 2719. "]")*
     arg_name:          [*note identifier: 22aa. | *note digit: 22fb.+]
     attribute_name:    *note identifier: 22aa.
     element_index:     *note digit: 22fb.+ | *note index_string: 271a.
     index_string:      <any source character except "]"> +
     conversion:        "r" | "s" | "a"
     format_spec:       *note format-spec;format_spec: 271b.

In less formal terms, the replacement field can start with a
'field_name' that specifies the object whose value is to be formatted
and inserted into the output instead of the replacement field.  The
'field_name' is optionally followed by a 'conversion' field, which is
preceded by an exclamation point ‘'!'’, and a 'format_spec', which is
preceded by a colon ‘':'’.  These specify a non-default format for the
replacement value.

See also the *note Format Specification Mini-Language: 4fa. section.

The 'field_name' itself begins with an 'arg_name' that is either a
number or a keyword.  If it’s a number, it refers to a positional
argument, and if it’s a keyword, it refers to a named keyword argument.
An 'arg_name' is treated as a number if a call to *note str.isdecimal():
2609. on the string would return true.  If the numerical arg_names in a
format string are 0, 1, 2, … in sequence, they can all be omitted (not
just some) and the numbers 0, 1, 2, … will be automatically inserted in
that order.  Because 'arg_name' is not quote-delimited, it is not
possible to specify arbitrary dictionary keys (e.g., the strings ‘'10'’
or ‘':-]'’) within a format string.  The 'arg_name' can be followed by
any number of index or attribute expressions.  An expression of the form
‘'.name'’ selects the named attribute using *note getattr(): dcc, while
an expression of the form ‘'[index]'’ does an index lookup using *note
__getitem__(): 588.

Cambiato nella versione 3.1: The positional argument specifiers can be
omitted for *note str.format(): 834, so ‘'{} {}'.format(a, b)’ is
equivalent to ‘'{0} {1}'.format(a, b)’.

Cambiato nella versione 3.4: The positional argument specifiers can be
omitted for *note Formatter: 10bf.

Some simple format string examples:

     "First, thou shalt count to {0}"  # References first positional argument
     "Bring me a {}"                   # Implicitly references the first positional argument
     "From {} to {}"                   # Same as "From {0} to {1}"
     "My quest is {name}"              # References keyword argument 'name'
     "Weight in tons {0.weight}"       # 'weight' attribute of first positional arg
     "Units destroyed: {players[0]}"   # First element of keyword argument 'players'.
The 'conversion' field causes a type coercion before formatting.
Normally, the job of formatting a value is done by the *note
__format__(): 832. method of the value itself.  However, in some cases
it is desirable to force a type to be formatted as a string, overriding
its own definition of formatting.  By converting the value to a string
before calling *note __format__(): 832, the normal formatting logic is
bypassed.

Three conversion flags are currently supported: ‘'!s'’ which calls *note
str(): 169. on the value, ‘'!r'’ which calls *note repr(): 1c1. and
‘'!a'’ which calls *note ascii(): 15ed.

Some examples:

     "Harold's a clever {0!s}"        # Calls str() on the argument first
     "Bring out the holy {name!r}"    # Calls repr() on the argument first
     "More {!a}"                      # Calls ascii() on the argument first

The 'format_spec' field contains a specification of how the value should
be presented, including such details as field width, alignment, padding,
decimal precision and so on.  Each value type can define its own
«formatting mini-language» or interpretation of the 'format_spec'.

Most built-in types support a common formatting mini-language, which is
described in the next section.

A 'format_spec' field can also include nested replacement fields within
it.  These nested replacement fields may contain a field name,
conversion flag and format specification, but deeper nesting is not
allowed.  The replacement fields within the format_spec are substituted
before the 'format_spec' string is interpreted.  This allows the
formatting of a value to be dynamically specified.

See the *note Format examples: 271d. section for some examples.

* Menu:

* Format Specification Mini-Language::
* Format examples::


File: python.info,  Node: Format Specification Mini-Language,  Next: Format examples,  Up: Format String Syntax

5.6.1.4 Format Specification Mini-Language
..........................................

«Format specifications» are used within replacement fields contained
within a format string to define how individual values are presented
(see *note Format String Syntax: 15a3, *note f-strings: 19a, and *note
t-strings: 17e2.).  They can also be passed directly to the built-in
*note format(): 199. function.  Each formattable type may define how the
format specification is to be interpreted.

Most built-in types implement the following options for format
specifications, although some of the formatting options are only
supported by the numeric types.

A general convention is that an empty format specification produces the
same result as if you had called *note str(): 169. on the value.  A
non-empty format specification typically modifies the result.

The general form of a 'standard format specifier' is:

     format_spec:             [*note options: 271f.][*note width_and_precision: 2720.][*note type: 2721.]
     options:                 [[*note fill: 2722.]*note align: 2723.][*note sign: 2724.]["z"]["#"]["0"]
     fill:                    <any character>
     align:                   "<" | ">" | "=" | "^"
     sign:                    "+" | "-" | " "
     width_and_precision:     [*note width_with_grouping: 2725.][*note precision_with_grouping: 2726.]
     width_with_grouping:     [*note width: 2727.][*note grouping: 2728.]
     precision_with_grouping: "." [*note precision: 2729.][*note grouping: 2728.] | "." *note grouping: 2728.
     width:                   *note digit: 22fb.+
     precision:               *note digit: 22fb.+
     grouping:                "," | "_"
     type:                    "b" | "c" | "d" | "e" | "E" | "f" | "F" | "g"
                              | "G" | "n" | "o" | "s" | "x" | "X" | "%"

If a valid 'align' value is specified, it can be preceded by a 'fill'
character that can be any character and defaults to a space if omitted.
It is not possible to use a literal curly brace (»‘{’» or «‘}’») as the
'fill' character in a *note formatted string literal: 19a. or when using
the *note str.format(): 834. method.  However, it is possible to insert
a curly brace with a nested replacement field.  This limitation doesn’t
affect the *note format(): 199. function.

The meaning of the various alignment options is as follows:

Option        Meaning
              
-----------------------------------------------------------------------------
              
‘'<'’         Forces the field to be left-aligned within the available
              space (this is the default for most objects).
              
              
‘'>'’         Forces the field to be right-aligned within the available
              space (this is the default for numbers).
              
              
‘'='’         Forces the padding to be placed after the sign (if any) but
              before the digits.  This is used for printing fields in the
              form “+000000120”.  This alignment option is only valid for
              numeric types, excluding *note complex: 197.  It becomes the
              default for numbers when “0” immediately precedes the field
              width.
              
              
‘'^'’         Forces the field to be centered within the available space.
              

Note that unless a minimum field width is defined, the field width will
always be the same size as the data to fill it, so that the alignment
option has no meaning in this case.

The 'sign' option is only valid for number types, and can be one of the
following:

Option        Meaning
              
-----------------------------------------------------------------------------
              
‘'+'’         Indicates that a sign should be used for both positive as
              well as negative numbers.
              
              
‘'-'’         Indicates that a sign should be used only for negative
              numbers (this is the default behavior).
              
              
space         Indicates that a leading space should be used on positive
              numbers, and a minus sign on negative numbers.
              

The ‘'z'’ option coerces negative zero floating-point values to positive
zero after rounding to the format precision.  This option is only valid
for floating-point presentation types.

Cambiato nella versione 3.11: Added the ‘'z'’ option (see also PEP
682(1)).

The ‘'#'’ option causes the «alternate form» to be used for the
conversion.  The alternate form is defined differently for different
types.  This option is only valid for integer, float and complex types.
For integers, when binary, octal, or hexadecimal output is used, this
option adds the respective prefix ‘'0b'’, ‘'0o'’, ‘'0x'’, or ‘'0X'’ to
the output value.  For float and complex the alternate form causes the
result of the conversion to always contain a decimal-point character,
even if no digits follow it.  Normally, a decimal-point character
appears in the result of these conversions only if a digit follows it.
In addition, for ‘'g'’ and ‘'G'’ conversions, trailing zeros are not
removed from the result.

The 'width' is a decimal integer defining the minimum total field width,
including any prefixes, separators, and other formatting characters.  If
not specified, then the field width will be determined by the content.

When no explicit alignment is given, preceding the 'width' field by a
zero (‘'0'’) character enables sign-aware zero-padding for numeric
types, excluding *note complex: 197.  This is equivalent to a 'fill'
character of ‘'0'’ with an 'alignment' type of ‘'='’.

Cambiato nella versione 3.10: Preceding the 'width' field by ‘'0'’ no
longer affects the default alignment for strings.

The 'precision' is a decimal integer indicating how many digits should
be displayed after the decimal point for presentation types ‘'f'’ and
‘'F'’, or before and after the decimal point for presentation types
‘'g'’ or ‘'G'’.  For string presentation types the field indicates the
maximum field size - in other words, how many characters will be used
from the field content.  The 'precision' is not allowed for integer
presentation types.

The 'grouping' option after 'width' and 'precision' fields specifies a
digit group separator for the integral and fractional parts of a number
respectively.  It can be one of the following:

Option        Meaning
              
-----------------------------------------------------------------------------
              
‘','’         Inserts a comma every 3 digits for integer presentation type
              ‘'d'’ and floating-point presentation types, excluding
              ‘'n'’.  For other presentation types, this option is not
              supported.
              
              
‘'_'’         Inserts an underscore every 3 digits for integer
              presentation type ‘'d'’ and floating-point presentation
              types, excluding ‘'n'’.  For integer presentation types
              ‘'b'’, ‘'o'’, ‘'x'’, and ‘'X'’, underscores are inserted
              every 4 digits.  For other presentation types, this option
              is not supported.
              

For a locale aware separator, use the ‘'n'’ presentation type instead.

Cambiato nella versione 3.1: Added the ‘','’ option (see also PEP
378(2)).

Cambiato nella versione 3.6: Added the ‘'_'’ option (see also PEP
515(3)).

Cambiato nella versione 3.14: Support the 'grouping' option for the
fractional part.

Finally, the 'type' determines how the data should be presented.

The available string presentation types are:

     Type          Meaning
                   
     -----------------------------------------------------------------------------
                   
     ‘'s'’         String format.  This is the default type for strings and may
                   be omitted.
                   
                   
     None          The same as ‘'s'’.
                   

The available integer presentation types are:

     Type          Meaning
                   
     -----------------------------------------------------------------------------
                   
     ‘'b'’         Binary format.  Outputs the number in base 2.
                   
                   
     ‘'c'’         Character.  Converts the integer to the corresponding
                   unicode character before printing.
                   
                   
     ‘'d'’         Decimal Integer.  Outputs the number in base 10.
                   
                   
     ‘'o'’         Octal format.  Outputs the number in base 8.
                   
                   
     ‘'x'’         Hex format.  Outputs the number in base 16, using lower-case
                   letters for the digits above 9.
                   
                   
     ‘'X'’         Hex format.  Outputs the number in base 16, using upper-case
                   letters for the digits above 9.  In case ‘'#'’ is specified,
                   the prefix ‘'0x'’ will be upper-cased to ‘'0X'’ as well.
                   
                   
     ‘'n'’         Number.  This is the same as ‘'d'’, except that it uses the
                   current locale setting to insert the appropriate digit group
                   separators.
                   
                   
     None          The same as ‘'d'’.
                   

In addition to the above presentation types, integers can be formatted
with the floating-point presentation types listed below (except ‘'n'’
and ‘None’).  When doing so, *note float(): 196. is used to convert the
integer to a floating-point number before formatting.

The available presentation types for *note float: 196. and *note
Decimal: 1fe. values are:

     Type          Meaning
                   
     -----------------------------------------------------------------------------
                   
     ‘'e'’         Scientific notation.  For a given precision ‘p’, formats the
                   number in scientific notation with the letter “e” separating
                   the coefficient from the exponent.  The coefficient has one
                   digit before and ‘p’ digits after the decimal point, for a
                   total of ‘p + 1’ significant digits.  With no precision
                   given, uses a precision of ‘6’ digits after the decimal
                   point for *note float: 196, and shows all coefficient digits
                   for *note Decimal: 1fe.  If ‘p=0’, the decimal point is
                   omitted unless the ‘#’ option is used.
                   
                   For *note float: 196, the exponent always contains at least
                   two digits, and is zero if the value is zero.
                   
                   
     ‘'E'’         Scientific notation.  Same as ‘'e'’ except it uses an upper
                   case “E” as the separator character.
                   
                   
     ‘'f'’         Fixed-point notation.  For a given precision ‘p’, formats
                   the number as a decimal number with exactly ‘p’ digits
                   following the decimal point.  With no precision given, uses
                   a precision of ‘6’ digits after the decimal point for
                   *note float: 196, and uses a precision large enough to show
                   all coefficient digits for *note Decimal: 1fe.  If ‘p=0’,
                   the decimal point is omitted unless the ‘#’ option is used.
                   
                   
     ‘'F'’         Fixed-point notation.  Same as ‘'f'’, but converts ‘nan’ to
                   ‘NAN’ and ‘inf’ to ‘INF’.
                   
                   
     ‘'g'’         General format.  For a given precision ‘p >= 1’, this rounds
                   the number to ‘p’ significant digits and then formats the
                   result in either fixed-point format or in scientific
                   notation, depending on its magnitude.  A precision of ‘0’ is
                   treated as equivalent to a precision of ‘1’.
                   
                   The precise rules are as follows: suppose that the result
                   formatted with presentation type ‘'e'’ and precision ‘p-1’
                   would have exponent ‘exp’.  Then, if ‘m <= exp < p’, where
                   ‘m’ is -4 for floats and -6 for *note Decimals: 1fe, the
                   number is formatted with presentation type ‘'f'’ and
                   precision ‘p-1-exp’.  Otherwise, the number is formatted
                   with presentation type ‘'e'’ and precision ‘p-1’.  In both
                   cases insignificant trailing zeros are removed from the
                   significand, and the decimal point is also removed if there
                   are no remaining digits following it, unless the ‘'#'’
                   option is used.
                   
                   With no precision given, uses a precision of ‘6’ significant
                   digits for *note float: 196.  For *note Decimal: 1fe, the
                   coefficient of the result is formed from the coefficient
                   digits of the value; scientific notation is used for values
                   smaller than ‘1e-6’ in absolute value and values where the
                   place value of the least significant digit is larger than 1,
                   and fixed-point notation is used otherwise.
                   
                   Positive and negative infinity, positive and negative zero,
                   and nans, are formatted as ‘inf’, ‘-inf’, ‘0’, ‘-0’ and
                   ‘nan’ respectively, regardless of the precision.
                   
                   
     ‘'G'’         General format.  Same as ‘'g'’ except switches to ‘'E'’ if
                   the number gets too large.  The representations of infinity
                   and NaN are uppercased, too.
                   
                   
     ‘'n'’         Number.  This is the same as ‘'g'’, except that it uses the
                   current locale setting to insert the appropriate digit group
                   separators for the integral part of a number.
                   
                   
     ‘'%'’         Percentage.  Multiplies the number by 100 and displays in
                   fixed (‘'f'’) format, followed by a percent sign.
                   
                   
     None          For *note float: 196. this is like the ‘'g'’ type, except
                   that when fixed-point notation is used to format the result,
                   it always includes at least one digit past the decimal
                   point, and switches to the scientific notation when ‘exp >=
                   p - 1’.  When the precision is not specified, the latter
                   will be as large as needed to represent the given value
                   faithfully.
                   
                   For *note Decimal: 1fe, this is the same as either ‘'g'’ or
                   ‘'G'’ depending on the value of ‘context.capitals’ for the
                   current decimal context.
                   
                   The overall effect is to match the output of
                   *note str(): 169. as altered by the other format modifiers.
                   

The result should be correctly rounded to a given precision ‘p’ of
digits after the decimal point.  The rounding mode for *note float: 196.
matches that of the *note round(): 14e2. builtin.  For *note Decimal:
1fe, the rounding mode of the current *note context: 272a. will be used.

The available presentation types for *note complex: 197. are the same as
those for *note float: 196. (‘'%'’ is not allowed).  Both the real and
imaginary components of a complex number are formatted as floating-point
numbers, according to the specified presentation type.  They are
separated by the mandatory sign of the imaginary part, the latter being
terminated by a ‘j’ suffix.  If the presentation type is missing, the
result will match the output of *note str(): 169. (complex numbers with
a non-zero real part are also surrounded by parentheses), possibly
altered by other format modifiers.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0682/

   (2) https://peps.python.org/pep-0378/

   (3) https://peps.python.org/pep-0515/


File: python.info,  Node: Format examples,  Prev: Format Specification Mini-Language,  Up: Format String Syntax

5.6.1.5 Format examples
.......................

This section contains examples of the *note str.format(): 834. syntax
and comparison with the old ‘%’-formatting.

In most of the cases the syntax is similar to the old ‘%’-formatting,
with the addition of the ‘{}’ and with ‘:’ used instead of ‘%’.  For
example, ‘'%03.2f'’ can be translated to ‘'{:03.2f}'’.

The new format syntax also supports new and different options, shown in
the following examples.

Accessing arguments by position:

     >>> '{0}, {1}, {2}'.format('a', 'b', 'c')
     'a, b, c'
     >>> '{}, {}, {}'.format('a', 'b', 'c')  # 3.1+ only
     'a, b, c'
     >>> '{2}, {1}, {0}'.format('a', 'b', 'c')
     'c, b, a'
     >>> '{2}, {1}, {0}'.format(*'abc')      # unpacking argument sequence
     'c, b, a'
     >>> '{0}{1}{0}'.format('abra', 'cad')   # arguments' indices can be repeated
     'abracadabra'

Accessing arguments by name:

     >>> 'Coordinates: {latitude}, {longitude}'.format(latitude='37.24N', longitude='-115.81W')
     'Coordinates: 37.24N, -115.81W'
     >>> coord = {'latitude': '37.24N', 'longitude': '-115.81W'}
     >>> 'Coordinates: {latitude}, {longitude}'.format(**coord)
     'Coordinates: 37.24N, -115.81W'

Accessing arguments” attributes:

     >>> c = 3-5j
     >>> ('The complex number {0} is formed from the real part {0.real} '
     ...  'and the imaginary part {0.imag}.').format(c)
     'The complex number (3-5j) is formed from the real part 3.0 and the imaginary part -5.0.'
     >>> class Point:
     ...     def __init__(self, x, y):
     ...         self.x, self.y = x, y
     ...     def __str__(self):
     ...         return 'Point({self.x}, {self.y})'.format(self=self)
     ...
     >>> str(Point(4, 2))
     'Point(4, 2)'

Accessing arguments” items:

     >>> coord = (3, 5)
     >>> 'X: {0[0]};  Y: {0[1]}'.format(coord)
     'X: 3;  Y: 5'

Replacing ‘%s’ and ‘%r’:

     >>> "repr() shows quotes: {!r}; str() doesn't: {!s}".format('test1', 'test2')
     "repr() shows quotes: 'test1'; str() doesn't: test2"

Aligning the text and specifying a width:

     >>> '{:<30}'.format('left aligned')
     'left aligned                  '
     >>> '{:>30}'.format('right aligned')
     '                 right aligned'
     >>> '{:^30}'.format('centered')
     '           centered           '
     >>> '{:*^30}'.format('centered')  # use '*' as a fill char
     '***********centered***********'

Replacing ‘%+f’, ‘%-f’, and ‘% f’ and specifying a sign:

     >>> '{:+f}; {:+f}'.format(3.14, -3.14)  # show it always
     '+3.140000; -3.140000'
     >>> '{: f}; {: f}'.format(3.14, -3.14)  # show a space for positive numbers
     ' 3.140000; -3.140000'
     >>> '{:-f}; {:-f}'.format(3.14, -3.14)  # show only the minus -- same as '{:f}; {:f}'
     '3.140000; -3.140000'

Replacing ‘%x’ and ‘%o’ and converting the value to different bases:

     >>> # format also supports binary numbers
     >>> "int: {0:d};  hex: {0:x};  oct: {0:o};  bin: {0:b}".format(42)
     'int: 42;  hex: 2a;  oct: 52;  bin: 101010'
     >>> # with 0x, 0o, or 0b as prefix:
     >>> "int: {0:d};  hex: {0:#x};  oct: {0:#o};  bin: {0:#b}".format(42)
     'int: 42;  hex: 0x2a;  oct: 0o52;  bin: 0b101010'

Using the comma or the underscore as a digit group separator:

     >>> '{:,}'.format(1234567890)
     '1,234,567,890'
     >>> '{:_}'.format(1234567890)
     '1_234_567_890'
     >>> '{:_b}'.format(1234567890)
     '100_1001_1001_0110_0000_0010_1101_0010'
     >>> '{:_x}'.format(1234567890)
     '4996_02d2'
     >>> '{:_}'.format(123456789.123456789)
     '123_456_789.12345679'
     >>> '{:.,}'.format(123456789.123456789)
     '123456789.123,456,79'
     >>> '{:,._}'.format(123456789.123456789)
     '123,456,789.123_456_79'

Expressing a percentage:

     >>> points = 19
     >>> total = 22
     >>> 'Correct answers: {:.2%}'.format(points/total)
     'Correct answers: 86.36%'

Using type-specific formatting:

     >>> import datetime
     >>> d = datetime.datetime(2010, 7, 4, 12, 15, 58)
     >>> '{:%Y-%m-%d %H:%M:%S}'.format(d)
     '2010-07-04 12:15:58'

Nesting arguments and more complex examples:

     >>> for align, text in zip('<^>', ['left', 'center', 'right']):
     ...     '{0:{fill}{align}16}'.format(text, fill=align, align=align)
     ...
     'left<<<<<<<<<<<<'
     '^^^^^center^^^^^'
     '>>>>>>>>>>>right'
     >>>
     >>> octets = [192, 168, 0, 1]
     >>> '{:02X}{:02X}{:02X}{:02X}'.format(*octets)
     'C0A80001'
     >>> int(_, 16)
     3232235521
     >>>
     >>> width = 5
     >>> for num in range(5,12):
     ...     for base in 'dXob':
     ...         print('{0:{width}{base}}'.format(num, base=base, width=width), end=' ')
     ...     print()
     ...
         5     5     5   101
         6     6     6   110
         7     7     7   111
         8     8    10  1000
         9     9    11  1001
        10     A    12  1010
        11     B    13  1011


File: python.info,  Node: Template strings $-strings,  Next: Helper functions,  Prev: Format String Syntax,  Up: string — Common string operations

5.6.1.6 Template strings ($-strings)
....................................

     Nota: The feature described here was introduced in Python 2.4; a
     simple templating method based upon regular expressions.  It
     predates *note str.format(): 834, *note formatted string literals:
     19a, and *note template string literals: 272e.

     It is unrelated to template string literals (t-strings), which were
     introduced in Python 3.14.  These evaluate to *note
     string.templatelib.Template: 16a. objects, found in the *note
     string.templatelib: d9. module.

Template strings provide simpler string substitutions as described in
PEP 292(1).  A primary use case for template strings is for
internationalization (i18n) since in that context, the simpler syntax
and functionality makes it easier to translate than other built-in
string formatting facilities in Python.  As an example of a library
built on template strings for i18n, see the flufl.i18n(2) package.

Template strings support ‘$’-based substitutions, using the following
rules:

   * ‘$$’ is an escape; it is replaced with a single ‘$’.

   * ‘$identifier’ names a substitution placeholder matching a mapping
     key of ‘"identifier"’.  By default, ‘"identifier"’ is restricted to
     any case-insensitive ASCII alphanumeric string (including
     underscores) that starts with an underscore or ASCII letter.  The
     first non-identifier character after the ‘$’ character terminates
     this placeholder specification.

   * ‘${identifier}’ is equivalent to ‘$identifier’.  It is required
     when valid identifier characters follow the placeholder but are not
     part of the placeholder, such as ‘"${noun}ification"’.

Any other appearance of ‘$’ in the string will result in a *note
ValueError: 2ec. being raised.

The *note string: d8. module provides a *note Template: 898. class that
implements these rules.  The methods of *note Template: 898. are:

 -- Classe: string.Template (template)

     The constructor takes a single argument which is the template
     string.

      -- Metodo: substitute (mapping={}, /, **kwds)

          Performs the template substitution, returning a new string.
          'mapping' is any dictionary-like object with keys that match
          the placeholders in the template.  Alternatively, you can
          provide keyword arguments, where the keywords are the
          placeholders.  When both 'mapping' and 'kwds' are given and
          there are duplicates, the placeholders from 'kwds' take
          precedence.

      -- Metodo: safe_substitute (mapping={}, /, **kwds)

          Like *note substitute(): 20bf, except that if placeholders are
          missing from 'mapping' and 'kwds', instead of raising a *note
          KeyError: 5e7. exception, the original placeholder will appear
          in the resulting string intact.  Also, unlike with *note
          substitute(): 20bf, any other appearances of the ‘$’ will
          simply return ‘$’ instead of raising *note ValueError: 2ec.

          While other exceptions may still occur, this method is called
          «safe» because it always tries to return a usable string
          instead of raising an exception.  In another sense, *note
          safe_substitute(): 20c0. may be anything other than safe,
          since it will silently ignore malformed templates containing
          dangling delimiters, unmatched braces, or placeholders that
          are not valid Python identifiers.

      -- Metodo: is_valid ()

          Returns ‘False’ if the template has invalid placeholders that
          will cause *note substitute(): 20bf. to raise *note
          ValueError: 2ec.

          Added in version 3.11.

      -- Metodo: get_identifiers ()

          Returns a list of the valid identifiers in the template, in
          the order they first appear, ignoring any invalid identifiers.

          Added in version 3.11.

     *note Template: 898. instances also provide one public data
     attribute:

      -- Attributo: template

          This is the object passed to the constructor’s 'template'
          argument.  In general, you shouldn’t change it, but read-only
          access is not enforced.

Here is an example of how to use a Template:

     >>> from string import Template
     >>> s = Template('$who likes $what')
     >>> s.substitute(who='tim', what='kung pao')
     'tim likes kung pao'
     >>> d = dict(who='tim')
     >>> Template('Give $who $100').substitute(d)
     Traceback (most recent call last):
     ...
     ValueError: Invalid placeholder in string: line 1, col 11
     >>> Template('$who likes $what').substitute(d)
     Traceback (most recent call last):
     ...
     KeyError: 'what'
     >>> Template('$who likes $what').safe_substitute(d)
     'tim likes $what'

Advanced usage: you can derive subclasses of *note Template: 898. to
customize the placeholder syntax, delimiter character, or the entire
regular expression used to parse template strings.  To do this, you can
override these class attributes:

   * 'delimiter' – This is the literal string describing a placeholder
     introducing delimiter.  The default value is ‘$’.  Note that this
     should 'not' be a regular expression, as the implementation will
     call *note re.escape(): e05. on this string as needed.  Note
     further that you cannot change the delimiter after class creation
     (i.e.  a different delimiter must be set in the subclass’s class
     namespace).

   * 'idpattern' – This is the regular expression describing the pattern
     for non-braced placeholders.  The default value is the regular
     expression ‘(?a:[_a-z][_a-z0-9]*)’.  If this is given and
     'braceidpattern' is ‘None’ this pattern will also apply to braced
     placeholders.

          Nota: Since default 'flags' is ‘re.IGNORECASE’, pattern
          ‘[a-z]’ can match with some non-ASCII characters.  That’s why
          we use the local ‘a’ flag here.

     Cambiato nella versione 3.7: 'braceidpattern' can be used to define
     separate patterns used inside and outside the braces.

   * 'braceidpattern' – This is like 'idpattern' but describes the
     pattern for braced placeholders.  Defaults to ‘None’ which means to
     fall back to 'idpattern' (i.e.  the same pattern is used both
     inside and outside braces).  If given, this allows you to define
     different patterns for braced and unbraced placeholders.

     Added in version 3.7.

   * 'flags' – The regular expression flags that will be applied when
     compiling the regular expression used for recognizing
     substitutions.  The default value is ‘re.IGNORECASE’.  Note that
     ‘re.VERBOSE’ will always be added to the flags, so custom
     'idpattern's must follow conventions for verbose regular
     expressions.

     Added in version 3.2.

Alternatively, you can provide the entire regular expression pattern by
overriding the class attribute 'pattern'.  If you do this, the value
must be a regular expression object with four named capturing groups.
The capturing groups correspond to the rules given above, along with the
invalid placeholder rule:

   * 'escaped' – This group matches the escape sequence, e.g.  ‘$$’, in
     the default pattern.

   * 'named' – This group matches the unbraced placeholder name; it
     should not include the delimiter in capturing group.

   * 'braced' – This group matches the brace enclosed placeholder name;
     it should not include either the delimiter or braces in the
     capturing group.

   * 'invalid' – This group matches any other delimiter pattern (usually
     a single delimiter), and it should appear last in the regular
     expression.

The methods on this class will raise *note ValueError: 2ec. if the
pattern matches the template without one of these named groups matching.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0292/

   (2) https://flufli18n.readthedocs.io/en/latest/


File: python.info,  Node: Helper functions,  Prev: Template strings $-strings,  Up: string — Common string operations

5.6.1.7 Helper functions
........................

 -- Funzione: string.capwords (s, sep=None)

     Split the argument into words using *note str.split(): 10ac,
     capitalize each word using *note str.capitalize(): 261a, and join
     the capitalized words using *note str.join(): 25e8.  If the
     optional second argument 'sep' is absent or ‘None’, runs of
     whitespace characters are replaced by a single space and leading
     and trailing whitespace are removed, otherwise 'sep' is used to
     split and join the words.


File: python.info,  Node: string templatelib — Support for template string literals,  Next: re — Regular expression operations,  Prev: string — Common string operations,  Up: Text Processing Services

5.6.2 ‘string.templatelib’ — Support for template string literals
-----------------------------------------------------------------

'Source code:' Lib/string/templatelib.py(1)

__________________________________________________________________

Vedi anche
..........

   * *note Format strings: 19a.

   * *note Template string literal (t-string) syntax: 17e2.

   * PEP 750(2)

* Menu:

* Template strings::
* Types::
* Helper functions: Helper functions<2>.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/string/templatelib.py

   (2) https://peps.python.org/pep-0750/


File: python.info,  Node: Template strings,  Next: Types,  Up: string templatelib — Support for template string literals

5.6.2.1 Template strings
........................

Added in version 3.14.

Template strings are a mechanism for custom string processing.  They
have the full flexibility of Python’s *note f-strings: 19a, but return a
*note Template: 16a. instance that gives access to the static and
interpolated (in curly brackets) parts of a string 'before' they are
combined.

To write a t-string, use a ‘'t'’ prefix instead of an ‘'f'’, like so:

     >>> pi = 3.14
     >>> t't-strings are new in Python {pi!s}!'
     Template(
        strings=('t-strings are new in Python ', '!'),
        interpolations=(Interpolation(3.14, 'pi', 's', ''),)
     )


File: python.info,  Node: Types,  Next: Helper functions<2>,  Prev: Template strings,  Up: string templatelib — Support for template string literals

5.6.2.2 Types
.............

 -- Classe: string.templatelib.Template

     The ‘Template’ class describes the contents of a template string.
     It is immutable, meaning that attributes of a template cannot be
     reassigned.

     The most common way to create a ‘Template’ instance is to use the
     *note template string literal syntax: 17e2.  This syntax is
     identical to that of *note f-strings: 19a, except that it uses a
     ‘t’ prefix in place of an ‘f’:

          >>> cheese = 'Red Leicester'
          >>> template = t"We're fresh out of {cheese}, sir."
          >>> type(template)
          <class 'string.templatelib.Template'>

     Templates are stored as sequences of literal *note strings: 2736.
     and dynamic *note interpolations: 2737.  A *note values: 2738.
     attribute holds the values of the interpolations:

          >>> cheese = 'Camembert'
          >>> template = t'Ah! We do have {cheese}.'
          >>> template.strings
          ('Ah! We do have ', '.')
          >>> template.interpolations
          (Interpolation('Camembert', ...),)
          >>> template.values
          ('Camembert',)

     The ‘strings’ tuple has one more element than ‘interpolations’ and
     ‘values’; the interpolations “belong” between the strings.  This
     may be easier to understand when tuples are aligned

          template.strings:  ('Ah! We do have ',              '.')
          template.values:   (                   'Camembert',    )

     Attributes
     ..........

      -- Attributo: strings: *note tuple: 614.[*note str: 169, ...]

          A *note tuple: 614. of the static strings in the template.

               >>> cheese = 'Camembert'
               >>> template = t'Ah! We do have {cheese}.'
               >>> template.strings
               ('Ah! We do have ', '.')

          Empty strings 'are' included in the tuple:

               >>> response = 'We do have '
               >>> cheese = 'Camembert'
               >>> template = t'Ah! {response}{cheese}.'
               >>> template.strings
               ('Ah! ', '', '.')

          The ‘strings’ tuple is never empty, and always contains one
          more string than the ‘interpolations’ and ‘values’ tuples:

               >>> t''.strings
               ('',)
               >>> t''.values
               ()
               >>> t'{'cheese'}'.strings
               ('', '')
               >>> t'{'cheese'}'.values
               ('cheese',)

      -- Attributo: interpolations: *note tuple: 614.[*note
               Interpolation: 16b, ...]

          A *note tuple: 614. of the interpolations in the template.

               >>> cheese = 'Camembert'
               >>> template = t'Ah! We do have {cheese}.'
               >>> template.interpolations
               (Interpolation('Camembert', 'cheese', None, ''),)

          The ‘interpolations’ tuple may be empty and always contains
          one fewer values than the ‘strings’ tuple:

               >>> t'Red Leicester'.interpolations
               ()

      -- Attributo: values: *note tuple: 614.[*note object: c80, ...]

          A tuple of all interpolated values in the template.

               >>> cheese = 'Camembert'
               >>> template = t'Ah! We do have {cheese}.'
               >>> template.values
               ('Camembert',)

          The ‘values’ tuple always has the same length as the
          ‘interpolations’ tuple.  It is always equivalent to
          ‘tuple(i.value for i in template.interpolations)’.

     Methods
     .......

      -- Metodo: __new__ (*args: str | Interpolation)

          While literal syntax is the most common way to create a
          ‘Template’, it is also possible to create them directly using
          the constructor:

               >>> from string.templatelib import Interpolation, Template
               >>> cheese = 'Camembert'
               >>> template = Template(
               ...     'Ah! We do have ', Interpolation(cheese, 'cheese'), '.'
               ... )
               >>> list(template)
               ['Ah! We do have ', Interpolation('Camembert', 'cheese', None, ''), '.']

          If multiple strings are passed consecutively, they will be
          concatenated into a single value in the *note strings: 2736.
          attribute.  For example, the following code creates a *note
          Template: 16a. with a single final string:

               >>> from string.templatelib import Template
               >>> template = Template('Ah! We do have ', 'Camembert', '.')
               >>> template.strings
               ('Ah! We do have Camembert.',)

          If multiple interpolations are passed consecutively, they will
          be treated as separate interpolations and an empty string will
          be inserted between them.  For example, the following code
          creates a template with empty placeholders in the *note
          strings: 2736. attribute:

               >>> from string.templatelib import Interpolation, Template
               >>> template = Template(
               ...     Interpolation('Camembert', 'cheese'),
               ...     Interpolation('.', 'punctuation'),
               ... )
               >>> template.strings
               ('', '', '')

      -- Describe: iter(template)

          Iterate over the template, yielding each non-empty string and
          *note Interpolation: 16b. in the correct order:

               >>> cheese = 'Camembert'
               >>> list(t'Ah! We do have {cheese}.')
               ['Ah! We do have ', Interpolation('Camembert', 'cheese', None, ''), '.']

               Attenzione: Empty strings are 'not' included in the
               iteration:

                    >>> response = 'We do have '
                    >>> cheese = 'Camembert'
                    >>> list(t'Ah! {response}{cheese}.')
                    ['Ah! ',
                     Interpolation('We do have ', 'response', None, ''),
                     Interpolation('Camembert', 'cheese', None, ''),
                     '.']

      -- Describe: template + other

      -- Describe: template += other

          Concatenate this template with another, returning a new
          ‘Template’ instance:

               >>> cheese = 'Camembert'
               >>> list(t'Ah! ' + t'We do have {cheese}.')
               ['Ah! We do have ', Interpolation('Camembert', 'cheese', None, ''), '.']

          Concatenating a ‘Template’ and a ‘str’ is 'not' supported.
          This is because it is unclear whether the string should be
          treated as a static string or an interpolation.  If you want
          to concatenate a ‘Template’ with a string, you should either
          wrap the string directly in a ‘Template’ (to treat it as a
          static string) or use an ‘Interpolation’ (to treat it as
          dynamic):

               >>> from string.templatelib import Interpolation, Template
               >>> template = t'Ah! '
               >>> # Treat 'We do have ' as a static string
               >>> template += Template('We do have ')
               >>> # Treat cheese as an interpolation
               >>> cheese = 'Camembert'
               >>> template += Template(Interpolation(cheese, 'cheese'))
               >>> list(template)
               ['Ah! We do have ', Interpolation('Camembert', 'cheese', None, '')]

 -- Classe: string.templatelib.Interpolation

     The ‘Interpolation’ type represents an expression inside a template
     string.  It is immutable, meaning that attributes of an
     interpolation cannot be reassigned.

     Interpolations support pattern matching, allowing you to match
     against their attributes with the *note match statement: a10.:

          >>> from string.templatelib import Interpolation
          >>> interpolation = t'{1. + 2.:.2f}'.interpolations[0]
          >>> interpolation
          Interpolation(3.0, '1. + 2.', None, '.2f')
          >>> match interpolation:
          ...     case Interpolation(value, expression, conversion, format_spec):
          ...         print(value, expression, conversion, format_spec, sep=' | ')
          ...
          3.0 | 1. + 2. | None | .2f

     Attributes
     ..........

      -- Attributo: value: *note object: c80.

          The evaluated value of the interpolation.

               >>> t'{1 + 2}'.interpolations[0].value
               3

      -- Attributo: expression: *note str: 169.

          For interpolations created by t-string literals, ‘expression’
          is the expression text found inside the curly brackets (‘{’ &
          ‘}’), including any whitespace, excluding the curly brackets
          themselves, and ending before the first ‘!’, ‘:’, or ‘=’ if
          any is present.  For manually created interpolations,
          ‘expression’ is the arbitrary string provided when
          constructing the interpolation instance.

          We recommend using valid Python expressions or the empty
          string for the ‘expression’ field of manually created
          ‘Interpolation’ instances, although this is not enforced at
          runtime.

               >>> t'{1 + 2}'.interpolations[0].expression
               '1 + 2'

      -- Attributo: conversion: *note Literal: a57.['a', 'r', 's'] |
               *note None: 886.

          The conversion to apply to the value, or ‘None’.

          The ‘conversion’ is the optional conversion to apply to the
          value:

               >>> t'{1 + 2!a}'.interpolations[0].conversion
               'a'

               Nota: Unlike f-strings, where conversions are applied
               automatically, the expected behavior with t-strings is
               that code that 'processes' the ‘Template’ will decide how
               to interpret and whether to apply the ‘conversion’.  For
               convenience, the *note convert(): 273c. function can be
               used to mimic f-string conversion semantics.

      -- Attributo: format_spec: *note str: 169.

          The format specification to apply to the value.

          The ‘format_spec’ is an optional, arbitrary string used as the
          format specification to present the value:

               >>> t'{1 + 2:.2f}'.interpolations[0].format_spec
               '.2f'

               Nota: Unlike f-strings, where format specifications are
               applied automatically via the *note format(): 199.
               protocol, the expected behavior with t-strings is that
               code that 'processes' the interpolation will decide how
               to interpret and whether to apply the format
               specification.  As a result, ‘format_spec’ values in
               interpolations can be arbitrary strings, including those
               that do not conform to the *note format(): 199. protocol.

     Methods
     .......

      -- Metodo: __new__ (value: object, expression: str, conversion:
               Literal['a', 'r', 's'] | None = None, format_spec: str =
               '')

          Create a new ‘Interpolation’ object from component parts.


          Parametri:

             * ‘value’ – The evaluated, in-scope result of the
               interpolation.

             * ‘expression’ – The text of a valid Python expression, or
               an empty string.

             * ‘conversion’ – The *note conversion: 15a3. to be used,
               one of ‘None’, ‘'a'’, ‘'r'’, or ‘'s'’.

             * ‘format_spec’ – An optional, arbitrary string used as the
               *note format specification: 4fa. to present the value.


File: python.info,  Node: Helper functions<2>,  Prev: Types,  Up: string templatelib — Support for template string literals

5.6.2.3 Helper functions
........................

 -- Funzione: string.templatelib.convert (obj, /, conversion)

     Applies formatted string literal *note conversion: 271c. semantics
     to the given object 'obj'.  This is frequently useful for custom
     template string processing logic.

     Three conversion flags are currently supported:

        * ‘'s'’ which calls *note str(): 169. on the value (like ‘!s’),

        * ‘'r'’ which calls *note repr(): 1c1. (like ‘!r’), and

        * ‘'a'’ which calls *note ascii(): 15ed. (like ‘!a’).

     If the conversion flag is ‘None’, 'obj' is returned unchanged.


File: python.info,  Node: re — Regular expression operations,  Next: difflib — Helpers for computing deltas,  Prev: string templatelib — Support for template string literals,  Up: Text Processing Services

5.6.3 ‘re’ — Regular expression operations
------------------------------------------

'Source code:' Lib/re/(1)

__________________________________________________________________

This module provides regular expression matching operations similar to
those found in Perl.

Both patterns and strings to be searched can be Unicode strings (*note
str: 169.) as well as 8-bit strings (*note bytes: 192.).  However,
Unicode strings and 8-bit strings cannot be mixed: that is, you cannot
match a Unicode string with a bytes pattern or vice-versa; similarly,
when asking for a substitution, the replacement string must be of the
same type as both the pattern and the search string.

Regular expressions use the backslash character (‘'\'’) to indicate
special forms or to allow special characters to be used without invoking
their special meaning.  This collides with Python’s usage of the same
character for the same purpose in string literals; for example, to match
a literal backslash, one might have to write ‘'\\\\'’ as the pattern
string, because the regular expression must be ‘\\’, and each backslash
must be expressed as ‘\\’ inside a regular Python string literal.  Also,
please note that any invalid escape sequences in Python’s usage of the
backslash in string literals now generate a *note SyntaxWarning: 1ae.
and in the future this will become a *note SyntaxError: 18e.  This
behaviour will happen even if it is a valid escape sequence for a
regular expression.

The solution is to use Python’s raw string notation for regular
expression patterns; backslashes are not handled in any special way in a
string literal prefixed with ‘'r'’.  So ‘r"\n"’ is a two-character
string containing ‘'\'’ and ‘'n'’, while ‘"\n"’ is a one-character
string containing a newline.  Usually patterns will be expressed in
Python code using this raw string notation.

It is important to note that most regular expression operations are
available as module-level functions and methods on *note compiled
regular expressions: 1189.  The functions are shortcuts that don’t
require you to compile a regex object first, but miss some fine-tuning
parameters.

Vedi anche
..........

The third-party regex(2) module, which has an API compatible with the
standard library *note re: be. module, but offers additional
functionality and a more thorough Unicode support.

* Menu:

* Regular Expression Syntax::
* Module Contents::
* Regular Expression Objects::
* Match Objects::
* Regular Expression Examples::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/re/

   (2) https://pypi.org/project/regex/


File: python.info,  Node: Regular Expression Syntax,  Next: Module Contents,  Up: re — Regular expression operations

5.6.3.1 Regular Expression Syntax
.................................

A regular expression (or RE) specifies a set of strings that matches it;
the functions in this module let you check if a particular string
matches a given regular expression (or if a given regular expression
matches a particular string, which comes down to the same thing).

Regular expressions can be concatenated to form new regular expressions;
if 'A' and 'B' are both regular expressions, then 'AB' is also a regular
expression.  In general, if a string 'p' matches 'A' and another string
'q' matches 'B', the string 'pq' will match AB. This holds unless 'A' or
'B' contain low precedence operations; boundary conditions between 'A'
and 'B'; or have numbered group references.  Thus, complex expressions
can easily be constructed from simpler primitive expressions like the
ones described here.  For details of the theory and implementation of
regular expressions, consult the Friedl book *note [Frie09]: 2744, or
almost any textbook about compiler construction.

A brief explanation of the format of regular expressions follows.  For
further information and a gentler presentation, consult the *note
Regular Expression HOWTO: 2745.

Regular expressions can contain both special and ordinary characters.
Most ordinary characters, like ‘'A'’, ‘'a'’, or ‘'0'’, are the simplest
regular expressions; they simply match themselves.  You can concatenate
ordinary characters, so ‘last’ matches the string ‘'last'’.  (In the
rest of this section, we’ll write RE’s in ‘this special style’, usually
without quotes, and strings to be matched ‘'in single quotes'’.)

Some characters, like ‘'|'’ or ‘'('’, are special.  Special characters
either stand for classes of ordinary characters, or affect how the
regular expressions around them are interpreted.

Repetition operators or quantifiers (‘*’, ‘+’, ‘?’, ‘{m,n}’, etc) cannot
be directly nested.  This avoids ambiguity with the non-greedy modifier
suffix ‘?’, and with other modifiers in other implementations.  To apply
a second repetition to an inner repetition, parentheses may be used.
For example, the expression ‘(?:a{6})*’ matches any multiple of six
‘'a'’ characters.

The special characters are:

‘.’

     (Dot.)  In the default mode, this matches any character except a
     newline.  If the *note DOTALL: 2746. flag has been specified, this
     matches any character including a newline.  ‘(?s:.)’ matches any
     character regardless of flags.

‘^’

     (Caret.)  Matches the start of the string, and in *note MULTILINE:
     2747. mode also matches immediately after each newline.

‘$’

     Matches the end of the string or just before the newline at the end
     of the string, and in *note MULTILINE: 2747. mode also matches
     before a newline.  ‘foo’ matches both “foo” and “foobar”, while the
     regular expression ‘foo$’ matches only “foo”.  More interestingly,
     searching for ‘foo.$’ in ‘'foo1\nfoo2\n'’ matches “foo2” normally,
     but “foo1” in *note MULTILINE: 2747. mode; searching for a single
     ‘$’ in ‘'foo\n'’ will find two (empty) matches: one just before the
     newline, and one at the end of the string.

‘*’

     Causes the resulting RE to match 0 or more repetitions of the
     preceding RE, as many repetitions as are possible.  ‘ab*’ will
     match “a”, “ab”, or “a” followed by any number of “b’s.

‘+’

     Causes the resulting RE to match 1 or more repetitions of the
     preceding RE. ‘ab+’ will match “a” followed by any non-zero number
     of “b’s; it will not match just “a”.

‘?’

     Causes the resulting RE to match 0 or 1 repetitions of the
     preceding RE. ‘ab?’ will match either “a” or “ab”.

‘*?’, ‘+?’, ‘??’

     The ‘'*'’, ‘'+'’, and ‘'?'’ quantifiers are all 'greedy'; they
     match as much text as possible.  Sometimes this behaviour isn’t
     desired; if the RE ‘<.*>’ is matched against ‘'<a> b <c>'’, it will
     match the entire string, and not just ‘'<a>'’.  Adding ‘?’ after
     the quantifier makes it perform the match in 'non-greedy' or
     'minimal' fashion; as 'few' characters as possible will be matched.
     Using the RE ‘<.*?>’ will match only ‘'<a>'’.

‘*+’, ‘++’, ‘?+’

     Like the ‘'*'’, ‘'+'’, and ‘'?'’ quantifiers, those where ‘'+'’ is
     appended also match as many times as possible.  However, unlike the
     true greedy quantifiers, these do not allow back-tracking when the
     expression following it fails to match.  These are known as
     'possessive' quantifiers.  For example, ‘a*a’ will match ‘'aaaa'’
     because the ‘a*’ will match all 4 ‘'a'’s, but, when the final ‘'a'’
     is encountered, the expression is backtracked so that in the end
     the ‘a*’ ends up matching 3 ‘'a'’s total, and the fourth ‘'a'’ is
     matched by the final ‘'a'’.  However, when ‘a*+a’ is used to match
     ‘'aaaa'’, the ‘a*+’ will match all 4 ‘'a'’, but when the final
     ‘'a'’ fails to find any more characters to match, the expression
     cannot be backtracked and will thus fail to match.  ‘x*+’, ‘x++’
     and ‘x?+’ are equivalent to ‘(?>x*)’, ‘(?>x+)’ and ‘(?>x?)’
     correspondingly.

     Added in version 3.11.

‘{m}’

     Specifies that exactly 'm' copies of the previous RE should be
     matched; fewer matches cause the entire RE not to match.  For
     example, ‘a{6}’ will match exactly six ‘'a'’ characters, but not
     five.

‘{m,n}’

     Causes the resulting RE to match from 'm' to 'n' repetitions of the
     preceding RE, attempting to match as many repetitions as possible.
     For example, ‘a{3,5}’ will match from 3 to 5 ‘'a'’ characters.
     Omitting 'm' specifies a lower bound of zero, and omitting 'n'
     specifies an infinite upper bound.  As an example, ‘a{4,}b’ will
     match ‘'aaaab'’ or a thousand ‘'a'’ characters followed by a ‘'b'’,
     but not ‘'aaab'’.  The comma may not be omitted or the modifier
     would be confused with the previously described form.

‘{m,n}?’

     Causes the resulting RE to match from 'm' to 'n' repetitions of the
     preceding RE, attempting to match as 'few' repetitions as possible.
     This is the non-greedy version of the previous quantifier.  For
     example, on the 6-character string ‘'aaaaaa'’, ‘a{3,5}’ will match
     5 ‘'a'’ characters, while ‘a{3,5}?’ will only match 3 characters.

‘{m,n}+’

     Causes the resulting RE to match from 'm' to 'n' repetitions of the
     preceding RE, attempting to match as many repetitions as possible
     'without' establishing any backtracking points.  This is the
     possessive version of the quantifier above.  For example, on the
     6-character string ‘'aaaaaa'’, ‘a{3,5}+aa’ attempt to match 5 ‘'a'’
     characters, then, requiring 2 more ‘'a'’s, will need more
     characters than available and thus fail, while ‘a{3,5}aa’ will
     match with ‘a{3,5}’ capturing 5, then 4 ‘'a'’s by backtracking and
     then the final 2 ‘'a'’s are matched by the final ‘aa’ in the
     pattern.  ‘x{m,n}+’ is equivalent to ‘(?>x{m,n})’.

     Added in version 3.11.

‘\’

     Either escapes special characters (permitting you to match
     characters like ‘'*'’, ‘'?'’, and so forth), or signals a special
     sequence; special sequences are discussed below.

     If you’re not using a raw string to express the pattern, remember
     that Python also uses the backslash as an escape sequence in string
     literals; if the escape sequence isn’t recognized by Python’s
     parser, the backslash and subsequent character are included in the
     resulting string.  However, if Python would recognize the resulting
     sequence, the backslash should be repeated twice.  This is
     complicated and hard to understand, so it’s highly recommended that
     you use raw strings for all but the simplest expressions.

‘[]’

     Used to indicate a set of characters.  In a set:

        * Characters can be listed individually, e.g.  ‘[amk]’ will
          match ‘'a'’, ‘'m'’, or ‘'k'’.

        * Ranges of characters can be indicated by giving two characters
          and separating them by a ‘'-'’, for example ‘[a-z]’ will match
          any lowercase ASCII letter, ‘[0-5][0-9]’ will match all the
          two-digits numbers from ‘00’ to ‘59’, and ‘[0-9A-Fa-f]’ will
          match any hexadecimal digit.  If ‘-’ is escaped (e.g.
          ‘[a\-z]’) or if it’s placed as the first or last character
          (e.g.  ‘[-a]’ or ‘[a-]’), it will match a literal ‘'-'’.

        * Special characters except backslash lose their special meaning
          inside sets.  For example, ‘[(+*)]’ will match any of the
          literal characters ‘'('’, ‘'+'’, ‘'*'’, or ‘')'’.

        * Backslash either escapes characters which have special meaning
          in a set such as ‘'-'’, ‘']'’, ‘'^'’ and ‘'\\'’ itself or
          signals a special sequence which represents a single character
          such as ‘\xa0’ or ‘\n’ or a character class such as ‘\w’ or
          ‘\S’ (defined below).  Note that ‘\b’ represents a single
          «backspace» character, not a word boundary as outside a set,
          and numeric escapes such as ‘\1’ are always octal escapes, not
          group references.  Special sequences which do not match a
          single character such as ‘\A’ and ‘\z’ are not allowed.

        * Characters that are not within a range can be matched by
          'complementing' the set.  If the first character of the set is
          ‘'^'’, all the characters that are 'not' in the set will be
          matched.  For example, ‘[^5]’ will match any character except
          ‘'5'’, and ‘[^^]’ will match any character except ‘'^'’.  ‘^’
          has no special meaning if it’s not the first character in the
          set.

        * To match a literal ‘']'’ inside a set, precede it with a
          backslash, or place it at the beginning of the set.  For
          example, both ‘[()[\]{}]’ and ‘[]()[{}]’ will match a right
          bracket, as well as left bracket, braces, and parentheses.

        * Support of nested sets and set operations as in Unicode
          Technical Standard #18(1) might be added in the future.  This
          would change the syntax, so to facilitate this change a *note
          FutureWarning: 659. will be raised in ambiguous cases for the
          time being.  That includes sets starting with a literal ‘'['’
          or containing literal character sequences ‘'--'’, ‘'&&'’,
          ‘'~~'’, and ‘'||'’.  To avoid a warning escape them with a
          backslash.

     Cambiato nella versione 3.7: *note FutureWarning: 659. is raised if
     a character set contains constructs that will change semantically
     in the future.

‘|’

     ‘A|B’, where 'A' and 'B' can be arbitrary REs, creates a regular
     expression that will match either 'A' or 'B'. An arbitrary number
     of REs can be separated by the ‘'|'’ in this way.  This can be used
     inside groups (see below) as well.  As the target string is
     scanned, REs separated by ‘'|'’ are tried from left to right.  When
     one pattern completely matches, that branch is accepted.  This
     means that once 'A' matches, 'B' will not be tested further, even
     if it would produce a longer overall match.  In other words, the
     ‘'|'’ operator is never greedy.  To match a literal ‘'|'’, use
     ‘\|’, or enclose it inside a character class, as in ‘[|]’.

‘(...)’

     Matches whatever regular expression is inside the parentheses, and
     indicates the start and end of a group; the contents of a group can
     be retrieved after a match has been performed, and can be matched
     later in the string with the ‘\number’ special sequence, described
     below.  To match the literals ‘'('’ or ‘')'’, use ‘\(’ or ‘\)’, or
     enclose them inside a character class: ‘[(]’, ‘[)]’.

‘(?...)’

     This is an extension notation (a ‘'?'’ following a ‘'('’ is not
     meaningful otherwise).  The first character after the ‘'?'’
     determines what the meaning and further syntax of the construct is.
     Extensions usually do not create a new group; ‘(?P<name>...)’ is
     the only exception to this rule.  Following are the currently
     supported extensions.

‘(?aiLmsux)’

     (One or more letters from the set ‘'a'’, ‘'i'’, ‘'L'’, ‘'m'’,
     ‘'s'’, ‘'u'’, ‘'x'’.)  The group matches the empty string; the
     letters set the corresponding flags for the entire regular
     expression:

        * *note re.A: 2748. (ASCII-only matching)

        * *note re.I: 2749. (ignore case)

        * *note re.L: 274a. (locale dependent)

        * *note re.M: 274b. (multi-line)

        * *note re.S: 274c. (dot matches all)

        * *note re.U: 274d. (Unicode matching)

        * *note re.X: 274e. (verbose)

     (The flags are described in *note Module Contents: 274f.)  This is
     useful if you wish to include the flags as part of the regular
     expression, instead of passing a 'flag' argument to the *note
     re.compile(): dd0. function.  Flags should be used first in the
     expression string.

     Cambiato nella versione 3.11: This construction can only be used at
     the start of the expression.

‘(?:...)’

     A non-capturing version of regular parentheses.  Matches whatever
     regular expression is inside the parentheses, but the substring
     matched by the group 'cannot' be retrieved after performing a match
     or referenced later in the pattern.

‘(?aiLmsux-imsx:...)’

     (Zero or more letters from the set ‘'a'’, ‘'i'’, ‘'L'’, ‘'m'’,
     ‘'s'’, ‘'u'’, ‘'x'’, optionally followed by ‘'-'’ followed by one
     or more letters from the ‘'i'’, ‘'m'’, ‘'s'’, ‘'x'’.)  The letters
     set or remove the corresponding flags for the part of the
     expression:

        * *note re.A: 2748. (ASCII-only matching)

        * *note re.I: 2749. (ignore case)

        * *note re.L: 274a. (locale dependent)

        * *note re.M: 274b. (multi-line)

        * *note re.S: 274c. (dot matches all)

        * *note re.U: 274d. (Unicode matching)

        * *note re.X: 274e. (verbose)

     (The flags are described in *note Module Contents: 274f.)

     The letters ‘'a'’, ‘'L'’ and ‘'u'’ are mutually exclusive when used
     as inline flags, so they can’t be combined or follow ‘'-'’.
     Instead, when one of them appears in an inline group, it overrides
     the matching mode in the enclosing group.  In Unicode patterns
     ‘(?a:...)’ switches to ASCII-only matching, and ‘(?u:...)’ switches
     to Unicode matching (default).  In bytes patterns ‘(?L:...)’
     switches to locale dependent matching, and ‘(?a:...)’ switches to
     ASCII-only matching (default).  This override is only in effect for
     the narrow inline group, and the original matching mode is restored
     outside of the group.

     Added in version 3.6.

     Cambiato nella versione 3.7: The letters ‘'a'’, ‘'L'’ and ‘'u'’
     also can be used in a group.

‘(?>...)’

     Attempts to match ‘...’ as if it was a separate regular expression,
     and if successful, continues to match the rest of the pattern
     following it.  If the subsequent pattern fails to match, the stack
     can only be unwound to a point 'before' the ‘(?>...)’ because once
     exited, the expression, known as an 'atomic group', has thrown away
     all stack points within itself.  Thus, ‘(?>.*).’ would never match
     anything because first the ‘.*’ would match all characters
     possible, then, having nothing left to match, the final ‘.’ would
     fail to match.  Since there are no stack points saved in the Atomic
     Group, and there is no stack point before it, the entire expression
     would thus fail to match.

     Added in version 3.11.

‘(?P<name>...)’

     Similar to regular parentheses, but the substring matched by the
     group is accessible via the symbolic group name 'name'.  Group
     names must be valid Python identifiers, and in *note bytes: 192.
     patterns they can only contain bytes in the ASCII range.  Each
     group name must be defined only once within a regular expression.
     A symbolic group is also a numbered group, just as if the group
     were not named.

     Named groups can be referenced in three contexts.  If the pattern
     is ‘(?P<quote>['"]).*?(?P=quote)’ (i.e.  matching a string quoted
     with either single or double quotes):

     Context of reference to group «quote»       Ways to reference it
                                                 
     -----------------------------------------------------------------------------------
                                                 
     in the same pattern itself                     * ‘(?P=quote)’ (as shown)
                                                 
                                                    * ‘\1’
                                                 
                                                 
     when processing match object 'm'               * ‘m.group('quote')’
                                                 
                                                    * ‘m.end('quote')’ (etc.)
                                                 
                                                 
     in a string passed to the 'repl' argument      * ‘\g<quote>’
     of ‘re.sub()’                               
                                                    * ‘\g<1>’
                                                 
                                                    * ‘\1’
                                                 

     Cambiato nella versione 3.12: In *note bytes: 192. patterns, group
     'name' can only contain bytes in the ASCII range
     (‘b'\x00'’-‘b'\x7f'’).

‘(?P=name)’

     A backreference to a named group; it matches whatever text was
     matched by the earlier group named 'name'.

‘(?#...)’

     A comment; the contents of the parentheses are simply ignored.

‘(?=...)’

     Matches if ‘...’ matches next, but doesn’t consume any of the
     string.  This is called a 'lookahead assertion'.  For example,
     ‘Isaac (?=Asimov)’ will match ‘'Isaac '’ only if it’s followed by
     ‘'Asimov'’.

‘(?!...)’

     Matches if ‘...’ doesn’t match next.  This is a 'negative lookahead
     assertion'.  For example, ‘Isaac (?!Asimov)’ will match ‘'Isaac '’
     only if it’s 'not' followed by ‘'Asimov'’.

‘(?<=...)’

     Matches if the current position in the string is preceded by a
     match for ‘...’ that ends at the current position.  This is called
     a 'positive lookbehind assertion'.  ‘(?<=abc)def’ will find a match
     in ‘'abcdef'’, since the lookbehind will back up 3 characters and
     check if the contained pattern matches.  The contained pattern must
     only match strings of some fixed length, meaning that ‘abc’ or
     ‘a|b’ are allowed, but ‘a*’ and ‘a{3,4}’ are not.  Note that
     patterns which start with positive lookbehind assertions will not
     match at the beginning of the string being searched; you will most
     likely want to use the *note search(): 1434. function rather than
     the *note match(): 1435. function:

          >>> import re
          >>> m = re.search('(?<=abc)def', 'abcdef')
          >>> m.group(0)
          'def'

     This example looks for a word following a hyphen:

          >>> m = re.search(r'(?<=-)\w+', 'spam-egg')
          >>> m.group(0)
          'egg'

     Cambiato nella versione 3.5: Added support for group references of
     fixed length.

‘(?<!...)’

     Matches if the current position in the string is not preceded by a
     match for ‘...’.  This is called a 'negative lookbehind assertion'.
     Similar to positive lookbehind assertions, the contained pattern
     must only match strings of some fixed length.  Patterns which start
     with negative lookbehind assertions may match at the beginning of
     the string being searched.

‘(?(id/name)yes-pattern|no-pattern)’

     Will try to match with ‘yes-pattern’ if the group with given 'id'
     or 'name' exists, and with ‘no-pattern’ if it doesn’t.
     ‘no-pattern’ is optional and can be omitted.  For example,
     ‘(<)?(\w+@\w+(?:\.\w+)+)(?(1)>|$)’ is a poor email matching
     pattern, which will match with ‘'<user@host.com>'’ as well as
     ‘'user@host.com'’, but not with ‘'<user@host.com'’ nor
     ‘'user@host.com>'’.

     Cambiato nella versione 3.12: Group 'id' can only contain ASCII
     digits.  In *note bytes: 192. patterns, group 'name' can only
     contain bytes in the ASCII range (‘b'\x00'’-‘b'\x7f'’).

The special sequences consist of ‘'\'’ and a character from the list
below.  If the ordinary character is not an ASCII digit or an ASCII
letter, then the resulting RE will match the second character.  For
example, ‘\$’ matches the character ‘'$'’.

‘\number’

     Matches the contents of the group of the same number.  Groups are
     numbered starting from 1.  For example, ‘(.+) \1’ matches ‘'the
     the'’ or ‘'55 55'’, but not ‘'thethe'’ (note the space after the
     group).  This special sequence can only be used to match one of the
     first 99 groups.  If the first digit of 'number' is 0, or 'number'
     is 3 octal digits long, it will not be interpreted as a group
     match, but as the character with octal value 'number'.  Inside the
     ‘'['’ and ‘']'’ of a character class, all numeric escapes are
     treated as characters.

‘\A’

     Matches only at the start of the string.

‘\b’

     Matches the empty string, but only at the beginning or end of a
     word.  A word is defined as a sequence of word characters.  Note
     that formally, ‘\b’ is defined as the boundary between a ‘\w’ and a
     ‘\W’ character (or vice versa), or between ‘\w’ and the beginning
     or end of the string.  This means that ‘r'\bat\b'’ matches ‘'at'’,
     ‘'at.'’, ‘'(at)'’, and ‘'as at ay'’ but not ‘'attempt'’ or
     ‘'atlas'’.

     The default word characters in Unicode (str) patterns are Unicode
     alphanumerics and the underscore, but this can be changed by using
     the *note ASCII: 83f. flag.  Word boundaries are determined by the
     current locale if the *note LOCALE: d65. flag is used.

          Nota: Inside a character range, ‘\b’ represents the backspace
          character, for compatibility with Python’s string literals.

‘\B’

     Matches the empty string, but only when it is 'not' at the
     beginning or end of a word.  This means that ‘r'at\B'’ matches
     ‘'athens'’, ‘'atom'’, ‘'attorney'’, but not ‘'at'’, ‘'at.'’, or
     ‘'at!'’.  ‘\B’ is the opposite of ‘\b’, so word characters in
     Unicode (str) patterns are Unicode alphanumerics or the underscore,
     although this can be changed by using the *note ASCII: 83f. flag.
     Word boundaries are determined by the current locale if the *note
     LOCALE: d65. flag is used.

     Cambiato nella versione 3.14: ‘\B’ now matches empty input string.

‘\d’

     For Unicode (str) patterns:

          Matches any Unicode decimal digit (that is, any character in
          Unicode character category [Nd](2)).  This includes ‘[0-9]’,
          and also many other digit characters.

          Matches ‘[0-9]’ if the *note ASCII: 83f. flag is used.

     For 8-bit (bytes) patterns:

          Matches any decimal digit in the ASCII character set; this is
          equivalent to ‘[0-9]’.

‘\D’

     Matches any character which is not a decimal digit.  This is the
     opposite of ‘\d’.

     Matches ‘[^0-9]’ if the *note ASCII: 83f. flag is used.

‘\s’

     For Unicode (str) patterns:

          Matches Unicode whitespace characters (as defined by *note
          str.isspace(): 2615.).  This includes ‘[ \t\n\r\f\v]’, and
          also many other characters, for example the non-breaking
          spaces mandated by typography rules in many languages.

          Matches ‘[ \t\n\r\f\v]’ if the *note ASCII: 83f. flag is used.

     For 8-bit (bytes) patterns:

          Matches characters considered whitespace in the ASCII
          character set; this is equivalent to ‘[ \t\n\r\f\v]’.

‘\S’

     Matches any character which is not a whitespace character.  This is
     the opposite of ‘\s’.

     Matches ‘[^ \t\n\r\f\v]’ if the *note ASCII: 83f. flag is used.

‘\w’

     For Unicode (str) patterns:

          Matches Unicode word characters; this includes all Unicode
          alphanumeric characters (as defined by *note str.isalnum():
          260d.), as well as the underscore (‘_’).

          Matches ‘[a-zA-Z0-9_]’ if the *note ASCII: 83f. flag is used.

     For 8-bit (bytes) patterns:

          Matches characters considered alphanumeric in the ASCII
          character set; this is equivalent to ‘[a-zA-Z0-9_]’.  If the
          *note LOCALE: d65. flag is used, matches characters considered
          alphanumeric in the current locale and the underscore.

‘\W’

     Matches any character which is not a word character.  This is the
     opposite of ‘\w’.  By default, matches non-underscore (‘_’)
     characters for which *note str.isalnum(): 260d. returns ‘False’.

     Matches ‘[^a-zA-Z0-9_]’ if the *note ASCII: 83f. flag is used.

     If the *note LOCALE: d65. flag is used, matches characters which
     are neither alphanumeric in the current locale nor the underscore.

‘\z’

     Matches only at the end of the string.

     Added in version 3.14.

‘\Z’

     The same as ‘\z’.  For compatibility with old Python versions.

Most of the *note escape sequences: 688. supported by Python string
literals are also accepted by the regular expression parser:

     \a      \b      \f      \n
     \N      \r      \t      \u
     \U      \v      \x      \\

(Note that ‘\b’ is used to represent word boundaries, and means
«backspace» only inside character classes.)

‘'\u'’, ‘'\U'’, and ‘'\N'’ escape sequences are only recognized in
Unicode (str) patterns.  In bytes patterns they are errors.  Unknown
escapes of ASCII letters are reserved for future use and treated as
errors.

Octal escapes are included in a limited form.  If the first digit is a
0, or if there are three octal digits, it is considered an octal escape.
Otherwise, it is a group reference.  As for string literals, octal
escapes are always at most three digits in length.

Cambiato nella versione 3.3: The ‘'\u'’ and ‘'\U'’ escape sequences have
been added.

Cambiato nella versione 3.6: Unknown escapes consisting of ‘'\'’ and an
ASCII letter now are errors.

Cambiato nella versione 3.8: The ‘'\N{NAME}'’ escape sequence has been
added.  As in string literals, it expands to the named Unicode character
(e.g.  ‘'\N{EM DASH}'’).

   ---------- Footnotes ----------

   (1) https://unicode.org/reports/tr18/

   (2) https://www.unicode.org/versions/Unicode15.0.0/ch04.pdf#G134153


File: python.info,  Node: Module Contents,  Next: Regular Expression Objects,  Prev: Regular Expression Syntax,  Up: re — Regular expression operations

5.6.3.2 Module Contents
.......................

The module defines several functions, constants, and an exception.  Some
of the functions are simplified versions of the full featured methods
for compiled regular expressions.  Most non-trivial applications always
use the compiled form.

* Menu:

* Flags::
* Functions::
* Exceptions: Exceptions<2>.


File: python.info,  Node: Flags,  Next: Functions,  Up: Module Contents

5.6.3.3 Flags
.............

Cambiato nella versione 3.6: Flag constants are now instances of *note
RegexFlag: 840, which is a subclass of *note enum.IntFlag: e9c.

 -- Classe: re.RegexFlag

     An *note enum.IntFlag: e9c. class containing the regex options
     listed below.

     Added in version 3.11: - added to ‘__all__’

 -- Dati: re.A
 -- Dati: re.ASCII

     Make ‘\w’, ‘\W’, ‘\b’, ‘\B’, ‘\d’, ‘\D’, ‘\s’ and ‘\S’ perform
     ASCII-only matching instead of full Unicode matching.  This is only
     meaningful for Unicode (str) patterns, and is ignored for bytes
     patterns.

     Corresponds to the inline flag ‘(?a)’.

          Nota: The *note U: 274d. flag still exists for backward
          compatibility, but is redundant in Python 3 since matches are
          Unicode by default for ‘str’ patterns, and Unicode matching
          isn’t allowed for bytes patterns.  *note UNICODE: d66. and the
          inline flag ‘(?u)’ are similarly redundant.

 -- Dati: re.DEBUG

     Display debug information about compiled expression.

     No corresponding inline flag.

 -- Dati: re.I
 -- Dati: re.IGNORECASE

     Perform case-insensitive matching; expressions like ‘[A-Z]’ will
     also match lowercase letters.  Full Unicode matching (such as ‘Ü’
     matching ‘ü’) also works unless the *note ASCII: 83f. flag is used
     to disable non-ASCII matches.  The current locale does not change
     the effect of this flag unless the *note LOCALE: d65. flag is also
     used.

     Corresponds to the inline flag ‘(?i)’.

     Note that when the Unicode patterns ‘[a-z]’ or ‘[A-Z]’ are used in
     combination with the *note IGNORECASE: 1a7e. flag, they will match
     the 52 ASCII letters and 4 additional non-ASCII letters: “İ”
     (U+0130, Latin capital letter I with dot above), “ı” (U+0131, Latin
     small letter dotless i), “ſ” (U+017F, Latin small letter long s)
     and “K” (U+212A, Kelvin sign).  If the *note ASCII: 83f. flag is
     used, only letters “a” to “z” and “A” to “Z” are matched.

 -- Dati: re.L
 -- Dati: re.LOCALE

     Make ‘\w’, ‘\W’, ‘\b’, ‘\B’ and case-insensitive matching dependent
     on the current locale.  This flag can be used only with bytes
     patterns.

     Corresponds to the inline flag ‘(?L)’.

          Avvertimento: This flag is discouraged; consider Unicode
          matching instead.  The locale mechanism is very unreliable as
          it only handles one «culture» at a time and only works with
          8-bit locales.  Unicode matching is enabled by default for
          Unicode (str) patterns and it is able to handle different
          locales and languages.

     Cambiato nella versione 3.6: *note LOCALE: d65. can be used only
     with bytes patterns and is not compatible with *note ASCII: 83f.

     Cambiato nella versione 3.7: Compiled regular expression objects
     with the *note LOCALE: d65. flag no longer depend on the locale at
     compile time.  Only the locale at matching time affects the result
     of matching.

 -- Dati: re.M
 -- Dati: re.MULTILINE

     When specified, the pattern character ‘'^'’ matches at the
     beginning of the string and at the beginning of each line
     (immediately following each newline); and the pattern character
     ‘'$'’ matches at the end of the string and at the end of each line
     (immediately preceding each newline).  By default, ‘'^'’ matches
     only at the beginning of the string, and ‘'$'’ only at the end of
     the string and immediately before the newline (if any) at the end
     of the string.

     Corresponds to the inline flag ‘(?m)’.

 -- Dati: re.NOFLAG

     Indicates no flag being applied, the value is ‘0’.  This flag may
     be used as a default value for a function keyword argument or as a
     base value that will be conditionally ORed with other flags.
     Example of use as a default value:

          def myfunc(text, flag=re.NOFLAG):
              return re.match(text, flag)

     Added in version 3.11.

 -- Dati: re.S
 -- Dati: re.DOTALL

     Make the ‘'.'’ special character match any character at all,
     including a newline; without this flag, ‘'.'’ will match anything
     'except' a newline.

     Corresponds to the inline flag ‘(?s)’.

 -- Dati: re.U
 -- Dati: re.UNICODE

     In Python 3, Unicode characters are matched by default for ‘str’
     patterns.  This flag is therefore redundant with 'no effect' and is
     only kept for backward compatibility.

     See *note ASCII: 83f. to restrict matching to ASCII characters
     instead.

 -- Dati: re.X
 -- Dati: re.VERBOSE

     This flag allows you to write regular expressions that look nicer
     and are more readable by allowing you to visually separate logical
     sections of the pattern and add comments.  Whitespace within the
     pattern is ignored, except when in a character class, or when
     preceded by an unescaped backslash, or within tokens like ‘*?’,
     ‘(?:’ or ‘(?P<...>’.  For example, ‘(? :’ and ‘* ?’ are not
     allowed.  When a line contains a ‘#’ that is not in a character
     class and is not preceded by an unescaped backslash, all characters
     from the leftmost such ‘#’ through the end of the line are ignored.

     This means that the two following regular expression objects that
     match a decimal number are functionally equal:

          a = re.compile(r"""\d +  # the integral part
                             \.    # the decimal point
                             \d *  # some fractional digits""", re.X)
          b = re.compile(r"\d+\.\d*")

     Corresponds to the inline flag ‘(?x)’.


File: python.info,  Node: Functions,  Next: Exceptions<2>,  Prev: Flags,  Up: Module Contents

5.6.3.4 Functions
.................

 -- Funzione: re.compile (pattern, flags=0)

     Compile a regular expression pattern into a *note regular
     expression object: 1189, which can be used for matching using its
     *note match(): 2757, *note search(): 2758. and other methods,
     described below.

     The expression’s behaviour can be modified by specifying a 'flags'
     value.  Values can be any of the *note flags: 2752. variables,
     combined using bitwise OR (the ‘|’ operator).

     The sequence

          prog = re.compile(pattern)
          result = prog.match(string)

     is equivalent to

          result = re.match(pattern, string)

     but using *note re.compile(): dd0. and saving the resulting regular
     expression object for reuse is more efficient when the expression
     will be used several times in a single program.

          Nota: The compiled versions of the most recent patterns passed
          to *note re.compile(): dd0. and the module-level matching
          functions are cached, so programs that use only a few regular
          expressions at a time needn’t worry about compiling regular
          expressions.

 -- Funzione: re.search (pattern, string, flags=0)

     Scan through 'string' looking for the first location where the
     regular expression 'pattern' produces a match, and return a
     corresponding *note Match: ec5.  Return ‘None’ if no position in
     the string matches the pattern; note that this is different from
     finding a zero-length match at some point in the string.

     The expression’s behaviour can be modified by specifying a 'flags'
     value.  Values can be any of the *note flags: 2752. variables,
     combined using bitwise OR (the ‘|’ operator).

 -- Funzione: re.match (pattern, string, flags=0)

     If zero or more characters at the beginning of 'string' match the
     regular expression 'pattern', return a corresponding *note Match:
     ec5.  Return ‘None’ if the string does not match the pattern; note
     that this is different from a zero-length match.

     Note that even in *note MULTILINE: 2747. mode, *note re.match():
     1435. will only match at the beginning of the string and not at the
     beginning of each line.

     If you want to locate a match anywhere in 'string', use *note
     search(): 1434. instead (see also *note search() vs.  match():
     2759.).

     The expression’s behaviour can be modified by specifying a 'flags'
     value.  Values can be any of the *note flags: 2752. variables,
     combined using bitwise OR (the ‘|’ operator).

 -- Funzione: re.fullmatch (pattern, string, flags=0)

     If the whole 'string' matches the regular expression 'pattern',
     return a corresponding *note Match: ec5.  Return ‘None’ if the
     string does not match the pattern; note that this is different from
     a zero-length match.

     The expression’s behaviour can be modified by specifying a 'flags'
     value.  Values can be any of the *note flags: 2752. variables,
     combined using bitwise OR (the ‘|’ operator).

     Added in version 3.4.

 -- Funzione: re.split (pattern, string, maxsplit=0, flags=0)

     Split 'string' by the occurrences of 'pattern'.  If capturing
     parentheses are used in 'pattern', then the text of all groups in
     the pattern are also returned as part of the resulting list.  If
     'maxsplit' is nonzero, at most 'maxsplit' splits occur, and the
     remainder of the string is returned as the final element of the
     list.

          >>> re.split(r'\W+', 'Words, words, words.')
          ['Words', 'words', 'words', '']
          >>> re.split(r'(\W+)', 'Words, words, words.')
          ['Words', ', ', 'words', ', ', 'words', '.', '']
          >>> re.split(r'\W+', 'Words, words, words.', maxsplit=1)
          ['Words', 'words, words.']
          >>> re.split('[a-f]+', '0a3B9', flags=re.IGNORECASE)
          ['0', '3', '9']

     If there are capturing groups in the separator and it matches at
     the start of the string, the result will start with an empty
     string.  The same holds for the end of the string:

          >>> re.split(r'(\W+)', '...words, words...')
          ['', '...', 'words', ', ', 'words', '...', '']

     That way, separator components are always found at the same
     relative indices within the result list.

     Adjacent empty matches are not possible, but an empty match can
     occur immediately after a non-empty match.

          >>> re.split(r'\b', 'Words, words, words.')
          ['', 'Words', ', ', 'words', ', ', 'words', '.']
          >>> re.split(r'\W*', '...words...')
          ['', '', 'w', 'o', 'r', 'd', 's', '', '']
          >>> re.split(r'(\W*)', '...words...')
          ['', '...', '', '', 'w', '', 'o', '', 'r', '', 'd', '', 's', '...', '', '', '']

     The expression’s behaviour can be modified by specifying a 'flags'
     value.  Values can be any of the *note flags: 2752. variables,
     combined using bitwise OR (the ‘|’ operator).

     Cambiato nella versione 3.1: Added the optional flags argument.

     Cambiato nella versione 3.7: Added support of splitting on a
     pattern that could match an empty string.

     Deprecato dalla versione 3.13: Passing 'maxsplit' and 'flags' as
     positional arguments is deprecated.  In future Python versions they
     will be *note keyword-only parameters: 5a5.

 -- Funzione: re.findall (pattern, string, flags=0)

     Return all non-overlapping matches of 'pattern' in 'string', as a
     list of strings or tuples.  The 'string' is scanned left-to-right,
     and matches are returned in the order found.  Empty matches are
     included in the result.

     The result depends on the number of capturing groups in the
     pattern.  If there are no groups, return a list of strings matching
     the whole pattern.  If there is exactly one group, return a list of
     strings matching that group.  If multiple groups are present,
     return a list of tuples of strings matching the groups.
     Non-capturing groups do not affect the form of the result.

          >>> re.findall(r'\bf[a-z]*', 'which foot or hand fell fastest')
          ['foot', 'fell', 'fastest']
          >>> re.findall(r'(\w+)=(\d+)', 'set width=20 and height=10')
          [('width', '20'), ('height', '10')]

     The expression’s behaviour can be modified by specifying a 'flags'
     value.  Values can be any of the *note flags: 2752. variables,
     combined using bitwise OR (the ‘|’ operator).

     Cambiato nella versione 3.7: Non-empty matches can now start just
     after a previous empty match.

 -- Funzione: re.finditer (pattern, string, flags=0)

     Return an *note iterator: 4c9. yielding *note Match: ec5. objects
     over all non-overlapping matches for the RE 'pattern' in 'string'.
     The 'string' is scanned left-to-right, and matches are returned in
     the order found.  Empty matches are included in the result.

     The expression’s behaviour can be modified by specifying a 'flags'
     value.  Values can be any of the *note flags: 2752. variables,
     combined using bitwise OR (the ‘|’ operator).

     Cambiato nella versione 3.7: Non-empty matches can now start just
     after a previous empty match.

 -- Funzione: re.sub (pattern, repl, string, count=0, flags=0)

     Return the string obtained by replacing the leftmost
     non-overlapping occurrences of 'pattern' in 'string' by the
     replacement 'repl'.  If the pattern isn’t found, 'string' is
     returned unchanged.  'repl' can be a string or a function; if it is
     a string, any backslash escapes in it are processed.  That is, ‘\n’
     is converted to a single newline character, ‘\r’ is converted to a
     carriage return, and so forth.  Unknown escapes of ASCII letters
     are reserved for future use and treated as errors.  Other unknown
     escapes such as ‘\&’ are left alone.  Backreferences, such as ‘\6’,
     are replaced with the substring matched by group 6 in the pattern.
     For example:

          >>> re.sub(r'def\s+([a-zA-Z_][a-zA-Z_0-9]*)\s*\(\s*\):',
          ...        r'static PyObject*\npy_\1(void)\n{',
          ...        'def myfunc():')
          'static PyObject*\npy_myfunc(void)\n{'

     If 'repl' is a function, it is called for every non-overlapping
     occurrence of 'pattern'.  The function takes a single *note Match:
     ec5. argument, and returns the replacement string.  For example:

          >>> def dashrepl(matchobj):
          ...     if matchobj.group(0) == '-': return ' '
          ...     else: return '-'
          ...
          >>> re.sub('-{1,2}', dashrepl, 'pro----gram-files')
          'pro--gram files'
          >>> re.sub(r'\sAND\s', ' & ', 'Baked Beans And Spam', flags=re.IGNORECASE)
          'Baked Beans & Spam'

     The pattern may be a string or a *note Pattern: 1b4f.

     The optional argument 'count' is the maximum number of pattern
     occurrences to be replaced; 'count' must be a non-negative integer.
     If omitted or zero, all occurrences will be replaced.

     Adjacent empty matches are not possible, but an empty match can
     occur immediately after a non-empty match.  As a result, ‘sub('x*',
     '-', 'abxd')’ returns ‘'-a-b--d-'’ instead of ‘'-a-b-d-'’.

     In string-type 'repl' arguments, in addition to the character
     escapes and backreferences described above, ‘\g<name>’ will use the
     substring matched by the group named ‘name’, as defined by the
     ‘(?P<name>...)’ syntax.  ‘\g<number>’ uses the corresponding group
     number; ‘\g<2>’ is therefore equivalent to ‘\2’, but isn’t
     ambiguous in a replacement such as ‘\g<2>0’.  ‘\20’ would be
     interpreted as a reference to group 20, not a reference to group 2
     followed by the literal character ‘'0'’.  The backreference ‘\g<0>’
     substitutes in the entire substring matched by the RE.

     The expression’s behaviour can be modified by specifying a 'flags'
     value.  Values can be any of the *note flags: 2752. variables,
     combined using bitwise OR (the ‘|’ operator).

     Cambiato nella versione 3.1: Added the optional flags argument.

     Cambiato nella versione 3.5: Unmatched groups are replaced with an
     empty string.

     Cambiato nella versione 3.6: Unknown escapes in 'pattern'
     consisting of ‘'\'’ and an ASCII letter now are errors.

     Cambiato nella versione 3.7: Unknown escapes in 'repl' consisting
     of ‘'\'’ and an ASCII letter now are errors.  An empty match can
     occur immediately after a non-empty match.

     Cambiato nella versione 3.12: Group 'id' can only contain ASCII
     digits.  In *note bytes: 192. replacement strings, group 'name' can
     only contain bytes in the ASCII range (‘b'\x00'’-‘b'\x7f'’).

     Deprecato dalla versione 3.13: Passing 'count' and 'flags' as
     positional arguments is deprecated.  In future Python versions they
     will be *note keyword-only parameters: 5a5.

 -- Funzione: re.subn (pattern, repl, string, count=0, flags=0)

     Perform the same operation as *note sub(): 5a3, but return a tuple
     ‘(new_string, number_of_subs_made)’.

     The expression’s behaviour can be modified by specifying a 'flags'
     value.  Values can be any of the *note flags: 2752. variables,
     combined using bitwise OR (the ‘|’ operator).

 -- Funzione: re.escape (pattern)

     Escape special characters in 'pattern'.  This is useful if you want
     to match an arbitrary literal string that may have regular
     expression metacharacters in it.  For example:

          >>> print(re.escape('https://www.python.org'))
          https://www\.python\.org

          >>> legal_chars = string.ascii_lowercase + string.digits + "!#$%&'*+-.^_`|~:"
          >>> print('[%s]+' % re.escape(legal_chars))
          [abcdefghijklmnopqrstuvwxyz0123456789!\#\$%\&'\*\+\-\.\^_`\|\~:]+

          >>> operators = ['+', '-', '*', '/', '**']
          >>> print('|'.join(map(re.escape, sorted(operators, reverse=True))))
          /|\-|\+|\*\*|\*

     This function must not be used for the replacement string in *note
     sub(): 5a3. and *note subn(): 5a4, only backslashes should be
     escaped.  For example:

          >>> digits_re = r'\d+'
          >>> sample = '/usr/sbin/sendmail - 0 errors, 12 warnings'
          >>> print(re.sub(digits_re, digits_re.replace('\\', r'\\'), sample))
          /usr/sbin/sendmail - \d+ errors, \d+ warnings

     Cambiato nella versione 3.3: The ‘'_'’ character is no longer
     escaped.

     Cambiato nella versione 3.7: Only characters that can have special
     meaning in a regular expression are escaped.  As a result, ‘'!'’,
     ‘'"'’, ‘'%'’, ‘"'"’, ‘','’, ‘'/'’, ‘':'’, ‘';'’, ‘'<'’, ‘'='’,
     ‘'>'’, ‘'@'’, and ‘"`"’ are no longer escaped.

 -- Funzione: re.purge ()

     Clear the regular expression cache.


File: python.info,  Node: Exceptions<2>,  Prev: Functions,  Up: Module Contents

5.6.3.5 Exceptions
..................

 -- Eccezione: re.PatternError (msg, pattern=None, pos=None)

     Exception raised when a string passed to one of the functions here
     is not a valid regular expression (for example, it might contain
     unmatched parentheses) or when some other error occurs during
     compilation or matching.  It is never an error if a string contains
     no match for a pattern.  The ‘PatternError’ instance has the
     following additional attributes:

      -- Attributo: msg

          The unformatted error message.

      -- Attributo: pattern

          The regular expression pattern.

      -- Attributo: pos

          The index in 'pattern' where compilation failed (may be
          ‘None’).

      -- Attributo: lineno

          The line corresponding to 'pos' (may be ‘None’).

      -- Attributo: colno

          The column corresponding to 'pos' (may be ‘None’).

     Cambiato nella versione 3.5: Added additional attributes.

     Cambiato nella versione 3.13: ‘PatternError’ was originally named
     ‘error’; the latter is kept as an alias for backward compatibility.


File: python.info,  Node: Regular Expression Objects,  Next: Match Objects,  Prev: Module Contents,  Up: re — Regular expression operations

5.6.3.6 Regular Expression Objects
..................................

 -- Classe: re.Pattern

     Compiled regular expression object returned by *note re.compile():
     dd0.

     Cambiato nella versione 3.9: *note re.Pattern: 1b4f. supports ‘[]’
     to indicate a Unicode (str) or bytes pattern.  See *note Tipo
     Generic Alias: 8c2.

 -- Metodo: Pattern.search (string[, pos[, endpos]])

     Scan through 'string' looking for the first location where this
     regular expression produces a match, and return a corresponding
     *note Match: ec5.  Return ‘None’ if no position in the string
     matches the pattern; note that this is different from finding a
     zero-length match at some point in the string.

     The optional second parameter 'pos' gives an index in the string
     where the search is to start; it defaults to ‘0’.  This is not
     completely equivalent to slicing the string; the ‘'^'’ pattern
     character matches at the real beginning of the string and at
     positions just after a newline, but not necessarily at the index
     where the search is to start.

     The optional parameter 'endpos' limits how far the string will be
     searched; it will be as if the string is 'endpos' characters long,
     so only the characters from 'pos' to ‘endpos - 1’ will be searched
     for a match.  If 'endpos' is less than 'pos', no match will be
     found; otherwise, if 'rx' is a compiled regular expression object,
     ‘rx.search(string, 0, 50)’ is equivalent to ‘rx.search(string[:50],
     0)’.

          >>> pattern = re.compile("d")
          >>> pattern.search("dog")     # Match at index 0
          <re.Match object; span=(0, 1), match='d'>
          >>> pattern.search("dog", 1)  # No match; search doesn't include the "d"

 -- Metodo: Pattern.match (string[, pos[, endpos]])

     If zero or more characters at the 'beginning' of 'string' match
     this regular expression, return a corresponding *note Match: ec5.
     Return ‘None’ if the string does not match the pattern; note that
     this is different from a zero-length match.

     The optional 'pos' and 'endpos' parameters have the same meaning as
     for the *note search(): 2758. method.

          >>> pattern = re.compile("o")
          >>> pattern.match("dog")      # No match as "o" is not at the start of "dog".
          >>> pattern.match("dog", 1)   # Match as "o" is the 2nd character of "dog".
          <re.Match object; span=(1, 2), match='o'>

     If you want to locate a match anywhere in 'string', use *note
     search(): 2758. instead (see also *note search() vs.  match():
     2759.).

 -- Metodo: Pattern.fullmatch (string[, pos[, endpos]])

     If the whole 'string' matches this regular expression, return a
     corresponding *note Match: ec5.  Return ‘None’ if the string does
     not match the pattern; note that this is different from a
     zero-length match.

     The optional 'pos' and 'endpos' parameters have the same meaning as
     for the *note search(): 2758. method.

          >>> pattern = re.compile("o[gh]")
          >>> pattern.fullmatch("dog")      # No match as "o" is not at the start of "dog".
          >>> pattern.fullmatch("ogre")     # No match as not the full string matches.
          >>> pattern.fullmatch("doggie", 1, 3)   # Matches within given limits.
          <re.Match object; span=(1, 3), match='og'>

     Added in version 3.4.

 -- Metodo: Pattern.split (string, maxsplit=0)

     Identical to the *note split(): 5a2. function, using the compiled
     pattern.

 -- Metodo: Pattern.findall (string[, pos[, endpos]])

     Similar to the *note findall(): 122c. function, using the compiled
     pattern, but also accepts optional 'pos' and 'endpos' parameters
     that limit the search region like for *note search(): 1434.

 -- Metodo: Pattern.finditer (string[, pos[, endpos]])

     Similar to the *note finditer(): 1701. function, using the compiled
     pattern, but also accepts optional 'pos' and 'endpos' parameters
     that limit the search region like for *note search(): 1434.

 -- Metodo: Pattern.sub (repl, string, count=0)

     Identical to the *note sub(): 5a3. function, using the compiled
     pattern.

 -- Metodo: Pattern.subn (repl, string, count=0)

     Identical to the *note subn(): 5a4. function, using the compiled
     pattern.

 -- Attributo: Pattern.flags

     The regex matching flags.  This is a combination of the flags given
     to *note compile(): dd0, any ‘(?...)’ inline flags in the pattern,
     and implicit flags such as *note UNICODE: d66. if the pattern is a
     Unicode string.

 -- Attributo: Pattern.groups

     The number of capturing groups in the pattern.

 -- Attributo: Pattern.groupindex

     A dictionary mapping any symbolic group names defined by ‘(?P<id>)’
     to group numbers.  The dictionary is empty if no symbolic groups
     were used in the pattern.

 -- Attributo: Pattern.pattern

     The pattern string from which the pattern object was compiled.

Cambiato nella versione 3.7: Added support of *note copy.copy(): 758.
and *note copy.deepcopy(): d67.  Compiled regular expression objects are
considered atomic.


File: python.info,  Node: Match Objects,  Next: Regular Expression Examples,  Prev: Regular Expression Objects,  Up: re — Regular expression operations

5.6.3.7 Match Objects
.....................

Match objects always have a boolean value of ‘True’.  Since *note
match(): 2757. and *note search(): 2758. return ‘None’ when there is no
match, you can test whether there was a match with a simple ‘if’
statement:

     match = re.search(pattern, string)
     if match:
         process(match)

 -- Classe: re.Match

     Match object returned by successful ‘match’es and ‘search’es.

     Cambiato nella versione 3.9: *note re.Match: ec5. supports ‘[]’ to
     indicate a Unicode (str) or bytes match.  See *note Tipo Generic
     Alias: 8c2.

 -- Metodo: Match.expand (template)

     Return the string obtained by doing backslash substitution on the
     template string 'template', as done by the *note sub(): 2760.
     method.  Escapes such as ‘\n’ are converted to the appropriate
     characters, and numeric backreferences (‘\1’, ‘\2’) and named
     backreferences (‘\g<1>’, ‘\g<name>’) are replaced by the contents
     of the corresponding group.  The backreference ‘\g<0>’ will be
     replaced by the entire match.

     Cambiato nella versione 3.5: Unmatched groups are replaced with an
     empty string.

 -- Metodo: Match.group ([group1, ...])

     Returns one or more subgroups of the match.  If there is a single
     argument, the result is a single string; if there are multiple
     arguments, the result is a tuple with one item per argument.
     Without arguments, 'group1' defaults to zero (the whole match is
     returned).  If a 'groupN' argument is zero, the corresponding
     return value is the entire matching string; if it is in the
     inclusive range [1..99], it is the string matching the
     corresponding parenthesized group.  If a group number is negative
     or larger than the number of groups defined in the pattern, an
     *note IndexError: 173c. exception is raised.  If a group is
     contained in a part of the pattern that did not match, the
     corresponding result is ‘None’.  If a group is contained in a part
     of the pattern that matched multiple times, the last match is
     returned.

          >>> m = re.match(r"(\w+) (\w+)", "Isaac Newton, physicist")
          >>> m.group(0)       # The entire match
          'Isaac Newton'
          >>> m.group(1)       # The first parenthesized subgroup.
          'Isaac'
          >>> m.group(2)       # The second parenthesized subgroup.
          'Newton'
          >>> m.group(1, 2)    # Multiple arguments give us a tuple.
          ('Isaac', 'Newton')

     If the regular expression uses the ‘(?P<name>...)’ syntax, the
     'groupN' arguments may also be strings identifying groups by their
     group name.  If a string argument is not used as a group name in
     the pattern, an *note IndexError: 173c. exception is raised.

     A moderately complicated example:

          >>> m = re.match(r"(?P<first_name>\w+) (?P<last_name>\w+)", "Malcolm Reynolds")
          >>> m.group('first_name')
          'Malcolm'
          >>> m.group('last_name')
          'Reynolds'

     Named groups can also be referred to by their index:

          >>> m.group(1)
          'Malcolm'
          >>> m.group(2)
          'Reynolds'

     If a group matches multiple times, only the last match is
     accessible:

          >>> m = re.match(r"(..)+", "a1b2c3")  # Matches 3 times.
          >>> m.group(1)                        # Returns only the last match.
          'c3'

 -- Metodo: Match.__getitem__ (g)

     This is identical to ‘m.group(g)’.  This allows easier access to an
     individual group from a match:

          >>> m = re.match(r"(\w+) (\w+)", "Isaac Newton, physicist")
          >>> m[0]       # The entire match
          'Isaac Newton'
          >>> m[1]       # The first parenthesized subgroup.
          'Isaac'
          >>> m[2]       # The second parenthesized subgroup.
          'Newton'

     Named groups are supported as well:

          >>> m = re.match(r"(?P<first_name>\w+) (?P<last_name>\w+)", "Isaac Newton")
          >>> m['first_name']
          'Isaac'
          >>> m['last_name']
          'Newton'

     Added in version 3.6.

 -- Metodo: Match.groups (default=None)

     Return a tuple containing all the subgroups of the match, from 1 up
     to however many groups are in the pattern.  The 'default' argument
     is used for groups that did not participate in the match; it
     defaults to ‘None’.

     For example:

          >>> m = re.match(r"(\d+)\.(\d+)", "24.1632")
          >>> m.groups()
          ('24', '1632')

     If we make the decimal place and everything after it optional, not
     all groups might participate in the match.  These groups will
     default to ‘None’ unless the 'default' argument is given:

          >>> m = re.match(r"(\d+)\.?(\d+)?", "24")
          >>> m.groups()      # Second group defaults to None.
          ('24', None)
          >>> m.groups('0')   # Now, the second group defaults to '0'.
          ('24', '0')

 -- Metodo: Match.groupdict (default=None)

     Return a dictionary containing all the 'named' subgroups of the
     match, keyed by the subgroup name.  The 'default' argument is used
     for groups that did not participate in the match; it defaults to
     ‘None’.  For example:

          >>> m = re.match(r"(?P<first_name>\w+) (?P<last_name>\w+)", "Malcolm Reynolds")
          >>> m.groupdict()
          {'first_name': 'Malcolm', 'last_name': 'Reynolds'}

 -- Metodo: Match.start ([group])
 -- Metodo: Match.end ([group])

     Return the indices of the start and end of the substring matched by
     'group'; 'group' defaults to zero (meaning the whole matched
     substring).  Return ‘-1’ if 'group' exists but did not contribute
     to the match.  For a match object 'm', and a group 'g' that did
     contribute to the match, the substring matched by group 'g'
     (equivalent to ‘m.group(g)’) is

          m.string[m.start(g):m.end(g)]

     Note that ‘m.start(group)’ will equal ‘m.end(group)’ if 'group'
     matched a null string.  For example, after ‘m = re.search('b(c?)',
     'cba')’, ‘m.start(0)’ is 1, ‘m.end(0)’ is 2, ‘m.start(1)’ and
     ‘m.end(1)’ are both 2, and ‘m.start(2)’ raises an *note IndexError:
     173c. exception.

     An example that will remove 'remove_this' from email addresses:

          >>> email = "tony@tiremove_thisger.net"
          >>> m = re.search("remove_this", email)
          >>> email[:m.start()] + email[m.end():]
          'tony@tiger.net'

 -- Metodo: Match.span ([group])

     For a match 'm', return the 2-tuple ‘(m.start(group),
     m.end(group))’.  Note that if 'group' did not contribute to the
     match, this is ‘(-1, -1)’.  'group' defaults to zero, the entire
     match.

 -- Attributo: Match.pos

     The value of 'pos' which was passed to the *note search(): 2758. or
     *note match(): 2757. method of a *note regex object: 1189.  This is
     the index into the string at which the RE engine started looking
     for a match.

 -- Attributo: Match.endpos

     The value of 'endpos' which was passed to the *note search(): 2758.
     or *note match(): 2757. method of a *note regex object: 1189.  This
     is the index into the string beyond which the RE engine will not
     go.

 -- Attributo: Match.lastindex

     The integer index of the last matched capturing group, or ‘None’ if
     no group was matched at all.  For example, the expressions ‘(a)b’,
     ‘((a)(b))’, and ‘((ab))’ will have ‘lastindex == 1’ if applied to
     the string ‘'ab'’, while the expression ‘(a)(b)’ will have
     ‘lastindex == 2’, if applied to the same string.

 -- Attributo: Match.lastgroup

     The name of the last matched capturing group, or ‘None’ if the
     group didn’t have a name, or if no group was matched at all.

 -- Attributo: Match.re

     The *note regular expression object: 1189. whose *note match():
     2757. or *note search(): 2758. method produced this match instance.

 -- Attributo: Match.string

     The string passed to *note match(): 2757. or *note search(): 2758.

Cambiato nella versione 3.7: Added support of *note copy.copy(): 758.
and *note copy.deepcopy(): d67.  Match objects are considered atomic.


File: python.info,  Node: Regular Expression Examples,  Prev: Match Objects,  Up: re — Regular expression operations

5.6.3.8 Regular Expression Examples
...................................

* Menu:

* Checking for a Pair::
* Simulating scanf(): Simulating scanf.
* search() vs. match(): search vs match.
* Making a Phonebook::
* Text Munging::
* Finding all Adverbs::
* Finding all Adverbs and their Positions::
* Raw String Notation::
* Writing a Tokenizer::


File: python.info,  Node: Checking for a Pair,  Next: Simulating scanf,  Up: Regular Expression Examples

5.6.3.9 Checking for a Pair
...........................

In this example, we’ll use the following helper function to display
match objects a little more gracefully:

     def displaymatch(match):
         if match is None:
             return None
         return '<Match: %r, groups=%r>' % (match.group(), match.groups())

Suppose you are writing a poker program where a player’s hand is
represented as a 5-character string with each character representing a
card, «a» for ace, «k» for king, «q» for queen, «j» for jack, «t» for
10, and «2» through «9» representing the card with that value.

To see if a given string is a valid hand, one could do the following:

     >>> valid = re.compile(r"^[a2-9tjqk]{5}$")
     >>> displaymatch(valid.match("akt5q"))  # Valid.
     "<Match: 'akt5q', groups=()>"
     >>> displaymatch(valid.match("akt5e"))  # Invalid.
     >>> displaymatch(valid.match("akt"))    # Invalid.
     >>> displaymatch(valid.match("727ak"))  # Valid.
     "<Match: '727ak', groups=()>"

That last hand, ‘"727ak"’, contained a pair, or two of the same valued
cards.  To match this with a regular expression, one could use
backreferences as such:

     >>> pair = re.compile(r".*(.).*\1")
     >>> displaymatch(pair.match("717ak"))     # Pair of 7s.
     "<Match: '717', groups=('7',)>"
     >>> displaymatch(pair.match("718ak"))     # No pairs.
     >>> displaymatch(pair.match("354aa"))     # Pair of aces.
     "<Match: '354aa', groups=('a',)>"

To find out what card the pair consists of, one could use the *note
group(): 122d. method of the match object in the following manner:

     >>> pair = re.compile(r".*(.).*\1")
     >>> pair.match("717ak").group(1)
     '7'

     # Error because re.match() returns None, which doesn't have a group() method:
     >>> pair.match("718ak").group(1)
     Traceback (most recent call last):
       File "<pyshell#23>", line 1, in <module>
         re.match(r".*(.).*\1", "718ak").group(1)
     AttributeError: 'NoneType' object has no attribute 'group'

     >>> pair.match("354aa").group(1)
     'a'


File: python.info,  Node: Simulating scanf,  Next: search vs match,  Prev: Checking for a Pair,  Up: Regular Expression Examples

5.6.3.10 Simulating scanf()
...........................

Python does not currently have an equivalent to ‘scanf()’.  Regular
expressions are generally more powerful, though also more verbose, than
‘scanf()’ format strings.  The table below offers some more-or-less
equivalent mappings between ‘scanf()’ format tokens and regular
expressions.

‘scanf()’ Token                      Regular Expression
                                     
---------------------------------------------------------------------------------------
                                     
‘%c’                                 ‘.’
                                     
                                     
‘%5c’                                ‘.{5}’
                                     
                                     
‘%d’                                 ‘[-+]?\d+’
                                     
                                     
‘%e’, ‘%E’, ‘%f’, ‘%g’               ‘[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?’
                                     
                                     
‘%i’                                 ‘[-+]?(0[xX][\dA-Fa-f]+|0[0-7]*|\d+)’
                                     
                                     
‘%o’                                 ‘[-+]?[0-7]+’
                                     
                                     
‘%s’                                 ‘\S+’
                                     
                                     
‘%u’                                 ‘\d+’
                                     
                                     
‘%x’, ‘%X’                           ‘[-+]?(0[xX])?[\dA-Fa-f]+’
                                     

To extract the filename and numbers from a string like

     /usr/sbin/sendmail - 0 errors, 4 warnings

you would use a ‘scanf()’ format like

     %s - %d errors, %d warnings

The equivalent regular expression would be

     (\S+) - (\d+) errors, (\d+) warnings


File: python.info,  Node: search vs match,  Next: Making a Phonebook,  Prev: Simulating scanf,  Up: Regular Expression Examples

5.6.3.11 search() vs. match()
.............................

Python offers different primitive operations based on regular
expressions:

   + *note re.match(): 1435. checks for a match only at the beginning of
     the string

   + *note re.search(): 1434. checks for a match anywhere in the string
     (this is what Perl does by default)

   + *note re.fullmatch(): 1187. checks for entire string to be a match

For example:

     >>> re.match("c", "abcdef")    # No match
     >>> re.search("c", "abcdef")   # Match
     <re.Match object; span=(2, 3), match='c'>
     >>> re.fullmatch("p.*n", "python") # Match
     <re.Match object; span=(0, 6), match='python'>
     >>> re.fullmatch("r.*n", "python") # No match

Regular expressions beginning with ‘'^'’ can be used with *note
search(): 1434. to restrict the match at the beginning of the string:

     >>> re.match("c", "abcdef")    # No match
     >>> re.search("^c", "abcdef")  # No match
     >>> re.search("^a", "abcdef")  # Match
     <re.Match object; span=(0, 1), match='a'>

Note however that in *note MULTILINE: 2747. mode *note match(): 1435.
only matches at the beginning of the string, whereas using *note
search(): 1434. with a regular expression beginning with ‘'^'’ will
match at the beginning of each line.

     >>> re.match("X", "A\nB\nX", re.MULTILINE)  # No match
     >>> re.search("^X", "A\nB\nX", re.MULTILINE)  # Match
     <re.Match object; span=(4, 5), match='X'>


File: python.info,  Node: Making a Phonebook,  Next: Text Munging,  Prev: search vs match,  Up: Regular Expression Examples

5.6.3.12 Making a Phonebook
...........................

*note split(): 5a2. splits a string into a list delimited by the passed
pattern.  The method is invaluable for converting textual data into data
structures that can be easily read and modified by Python as
demonstrated in the following example that creates a phonebook.

First, here is the input.  Normally it may come from a file, here we are
using triple-quoted string syntax

     >>> text = """Ross McFluff: 834.345.1254 155 Elm Street
     ...
     ... Ronald Heathmore: 892.345.3428 436 Finley Avenue
     ... Frank Burger: 925.541.7625 662 South Dogwood Way
     ...
     ...
     ... Heather Albrecht: 548.326.4584 919 Park Place"""

The entries are separated by one or more newlines.  Now we convert the
string into a list with each nonempty line having its own entry:

     >>> entries = re.split("\n+", text)
     >>> entries
     ['Ross McFluff: 834.345.1254 155 Elm Street',
     'Ronald Heathmore: 892.345.3428 436 Finley Avenue',
     'Frank Burger: 925.541.7625 662 South Dogwood Way',
     'Heather Albrecht: 548.326.4584 919 Park Place']

Finally, split each entry into a list with first name, last name,
telephone number, and address.  We use the ‘maxsplit’ parameter of *note
split(): 5a2. because the address has spaces, our splitting pattern, in
it:

     >>> [re.split(":? ", entry, maxsplit=3) for entry in entries]
     [['Ross', 'McFluff', '834.345.1254', '155 Elm Street'],
     ['Ronald', 'Heathmore', '892.345.3428', '436 Finley Avenue'],
     ['Frank', 'Burger', '925.541.7625', '662 South Dogwood Way'],
     ['Heather', 'Albrecht', '548.326.4584', '919 Park Place']]

The ‘:?’ pattern matches the colon after the last name, so that it does
not occur in the result list.  With a ‘maxsplit’ of ‘4’, we could
separate the house number from the street name:

     >>> [re.split(":? ", entry, maxsplit=4) for entry in entries]
     [['Ross', 'McFluff', '834.345.1254', '155', 'Elm Street'],
     ['Ronald', 'Heathmore', '892.345.3428', '436', 'Finley Avenue'],
     ['Frank', 'Burger', '925.541.7625', '662', 'South Dogwood Way'],
     ['Heather', 'Albrecht', '548.326.4584', '919', 'Park Place']]


File: python.info,  Node: Text Munging,  Next: Finding all Adverbs,  Prev: Making a Phonebook,  Up: Regular Expression Examples

5.6.3.13 Text Munging
.....................

*note sub(): 5a3. replaces every occurrence of a pattern with a string
or the result of a function.  This example demonstrates using *note
sub(): 5a3. with a function to «munge» text, or randomize the order of
all the characters in each word of a sentence except for the first and
last characters:

     >>> def repl(m):
     ...     inner_word = list(m.group(2))
     ...     random.shuffle(inner_word)
     ...     return m.group(1) + "".join(inner_word) + m.group(3)
     ...
     >>> text = "Professor Abdolmalek, please report your absences promptly."
     >>> re.sub(r"(\w)(\w+)(\w)", repl, text)
     'Poefsrosr Aealmlobdk, pslaee reorpt your abnseces plmrptoy.'
     >>> re.sub(r"(\w)(\w+)(\w)", repl, text)
     'Pofsroser Aodlambelk, plasee reoprt yuor asnebces potlmrpy.'


File: python.info,  Node: Finding all Adverbs,  Next: Finding all Adverbs and their Positions,  Prev: Text Munging,  Up: Regular Expression Examples

5.6.3.14 Finding all Adverbs
............................

*note findall(): 122c. matches 'all' occurrences of a pattern, not just
the first one as *note search(): 1434. does.  For example, if a writer
wanted to find all of the adverbs in some text, they might use *note
findall(): 122c. in the following manner:

     >>> text = "He was carefully disguised but captured quickly by police."
     >>> re.findall(r"\w+ly\b", text)
     ['carefully', 'quickly']


File: python.info,  Node: Finding all Adverbs and their Positions,  Next: Raw String Notation,  Prev: Finding all Adverbs,  Up: Regular Expression Examples

5.6.3.15 Finding all Adverbs and their Positions
................................................

If one wants more information about all matches of a pattern than the
matched text, *note finditer(): 1701. is useful as it provides *note
Match: ec5. objects instead of strings.  Continuing with the previous
example, if a writer wanted to find all of the adverbs 'and their
positions' in some text, they would use *note finditer(): 1701. in the
following manner:

     >>> text = "He was carefully disguised but captured quickly by police."
     >>> for m in re.finditer(r"\w+ly\b", text):
     ...     print('%02d-%02d: %s' % (m.start(), m.end(), m.group(0)))
     07-16: carefully
     40-47: quickly


File: python.info,  Node: Raw String Notation,  Next: Writing a Tokenizer,  Prev: Finding all Adverbs and their Positions,  Up: Regular Expression Examples

5.6.3.16 Raw String Notation
............................

Raw string notation (‘r"text"’) keeps regular expressions sane.  Without
it, every backslash (‘'\'’) in a regular expression would have to be
prefixed with another one to escape it.  For example, the two following
lines of code are functionally identical:

     >>> re.match(r"\W(.)\1\W", " ff ")
     <re.Match object; span=(0, 4), match=' ff '>
     >>> re.match("\\W(.)\\1\\W", " ff ")
     <re.Match object; span=(0, 4), match=' ff '>

When one wants to match a literal backslash, it must be escaped in the
regular expression.  With raw string notation, this means ‘r"\\"’.
Without raw string notation, one must use ‘"\\\\"’, making the following
lines of code functionally identical:

     >>> re.match(r"\\", r"\\")
     <re.Match object; span=(0, 1), match='\\'>
     >>> re.match("\\\\", r"\\")
     <re.Match object; span=(0, 1), match='\\'>


File: python.info,  Node: Writing a Tokenizer,  Prev: Raw String Notation,  Up: Regular Expression Examples

5.6.3.17 Writing a Tokenizer
............................

A tokenizer or scanner(1) analyzes a string to categorize groups of
characters.  This is a useful first step in writing a compiler or
interpreter.

The text categories are specified with regular expressions.  The
technique is to combine those into a single master regular expression
and to loop over successive matches:

     from typing import NamedTuple
     import re

     class Token(NamedTuple):
         type: str
         value: str
         line: int
         column: int

     def tokenize(code):
         keywords = {'IF', 'THEN', 'ENDIF', 'FOR', 'NEXT', 'GOSUB', 'RETURN'}
         token_specification = [
             ('NUMBER',   r'\d+(\.\d*)?'),  # Integer or decimal number
             ('ASSIGN',   r':='),           # Assignment operator
             ('END',      r';'),            # Statement terminator
             ('ID',       r'[A-Za-z]+'),    # Identifiers
             ('OP',       r'[+\-*/]'),      # Arithmetic operators
             ('NEWLINE',  r'\n'),           # Line endings
             ('SKIP',     r'[ \t]+'),       # Skip over spaces and tabs
             ('MISMATCH', r'.'),            # Any other character
         ]
         tok_regex = '|'.join('(?P<%s>%s)' % pair for pair in token_specification)
         line_num = 1
         line_start = 0
         for mo in re.finditer(tok_regex, code):
             kind = mo.lastgroup
             value = mo.group()
             column = mo.start() - line_start
             if kind == 'NUMBER':
                 value = float(value) if '.' in value else int(value)
             elif kind == 'ID' and value in keywords:
                 kind = value
             elif kind == 'NEWLINE':
                 line_start = mo.end()
                 line_num += 1
                 continue
             elif kind == 'SKIP':
                 continue
             elif kind == 'MISMATCH':
                 raise RuntimeError(f'{value!r} unexpected on line {line_num}')
             yield Token(kind, value, line_num, column)

     statements = '''
         IF quantity THEN
             total := total + price * quantity;
             tax := price * 0.05;
         ENDIF;
     '''

     for token in tokenize(statements):
         print(token)

The tokenizer produces the following output:

     Token(type='IF', value='IF', line=2, column=4)
     Token(type='ID', value='quantity', line=2, column=7)
     Token(type='THEN', value='THEN', line=2, column=16)
     Token(type='ID', value='total', line=3, column=8)
     Token(type='ASSIGN', value=':=', line=3, column=14)
     Token(type='ID', value='total', line=3, column=17)
     Token(type='OP', value='+', line=3, column=23)
     Token(type='ID', value='price', line=3, column=25)
     Token(type='OP', value='*', line=3, column=31)
     Token(type='ID', value='quantity', line=3, column=33)
     Token(type='END', value=';', line=3, column=41)
     Token(type='ID', value='tax', line=4, column=8)
     Token(type='ASSIGN', value=':=', line=4, column=12)
     Token(type='ID', value='price', line=4, column=15)
     Token(type='OP', value='*', line=4, column=21)
     Token(type='NUMBER', value=0.05, line=4, column=23)
     Token(type='END', value=';', line=4, column=27)
     Token(type='ENDIF', value='ENDIF', line=5, column=4)
     Token(type='END', value=';', line=5, column=9)

(Frie09) Friedl, Jeffrey.  Mastering Regular Expressions.  3rd ed.,
O’Reilly Media, 2009.  The third edition of the book no longer covers
Python at all, but the first edition covered writing good regular
expression patterns in great detail.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Lexical_analysis


File: python.info,  Node: difflib — Helpers for computing deltas,  Next: textwrap — Text wrapping and filling,  Prev: re — Regular expression operations,  Up: Text Processing Services

5.6.4 ‘difflib’ — Helpers for computing deltas
----------------------------------------------

'Source code:' Lib/difflib.py(1)

__________________________________________________________________

This module provides classes and functions for comparing sequences.  It
can be used for example, for comparing files, and can produce
information about file differences in various formats, including HTML
and context and unified diffs.  For comparing directories and files, see
also, the *note filecmp: 5e. module.

 -- Classe: difflib.SequenceMatcher

     This is a flexible class for comparing pairs of sequences of any
     type, so long as the sequence elements are *note hashable: 825.
     The basic algorithm predates, and is a little fancier than, an
     algorithm published in the late 1980’s by Ratcliff and Obershelp
     under the hyperbolic name «gestalt pattern matching.» The idea is
     to find the longest contiguous matching subsequence that contains
     no «junk» elements; these «junk» elements are ones that are
     uninteresting in some sense, such as blank lines or whitespace.
     (Handling junk is an extension to the Ratcliff and Obershelp
     algorithm.)  The same idea is then applied recursively to the
     pieces of the sequences to the left and to the right of the
     matching subsequence.  This does not yield minimal edit sequences,
     but does tend to yield matches that «look right» to people.

     'Timing:' The basic Ratcliff-Obershelp algorithm is cubic time in
     the worst case and quadratic time in the expected case.  *note
     SequenceMatcher: 121b. is quadratic time for the worst case and has
     expected-case behavior dependent in a complicated way on how many
     elements the sequences have in common; best case time is linear.

     'Automatic junk heuristic:' *note SequenceMatcher: 121b. supports a
     heuristic that automatically treats certain sequence items as junk.
     The heuristic counts how many times each individual item appears in
     the sequence.  If an item’s duplicates (after the first one)
     account for more than 1% of the sequence and the sequence is at
     least 200 items long, this item is marked as «popular» and is
     treated as junk for the purpose of sequence matching.  This
     heuristic can be turned off by setting the ‘autojunk’ argument to
     ‘False’ when creating the *note SequenceMatcher: 121b.

     Cambiato nella versione 3.2: Added the 'autojunk' parameter.

 -- Classe: difflib.Differ

     This is a class for comparing sequences of lines of text, and
     producing human-readable differences or deltas.  Differ uses *note
     SequenceMatcher: 121b. both to compare sequences of lines, and to
     compare sequences of characters within similar (near-matching)
     lines.

     Each line of a *note Differ: 2780. delta begins with a two-letter
     code:

     Code           Meaning
                    
     ---------------------------------------------------------------
                    
     ‘'- '’         line unique to sequence 1
                    
                    
     ‘'+ '’         line unique to sequence 2
                    
                    
     ‘' '’          line common to both sequences
                    
                    
     ‘'? '’         line not present in either input sequence
                    

     Lines beginning with “‘?’” attempt to guide the eye to intraline
     differences, and were not present in either input sequence.  These
     lines can be confusing if the sequences contain whitespace
     characters, such as spaces, tabs or line breaks.

 -- Classe: difflib.HtmlDiff

     This class can be used to create an HTML table (or a complete HTML
     file containing the table) showing a side by side, line by line
     comparison of text with inter-line and intra-line change
     highlights.  The table can be generated in either full or
     contextual difference mode.

     The constructor for this class is:

      -- Metodo: __init__ (tabsize=8, wrapcolumn=None, linejunk=None,
               charjunk=IS_CHARACTER_JUNK)

          Initializes instance of *note HtmlDiff: 201.

          'tabsize' is an optional keyword argument to specify tab stop
          spacing and defaults to ‘8’.

          'wrapcolumn' is an optional keyword to specify column number
          where lines are broken and wrapped, defaults to ‘None’ where
          lines are not wrapped.

          'linejunk' and 'charjunk' are optional keyword arguments
          passed into *note ndiff(): 2782. (used by *note HtmlDiff: 201.
          to generate the side by side HTML differences).  See *note
          ndiff(): 2782. documentation for argument default values and
          descriptions.

     The following methods are public:

      -- Metodo: make_file (fromlines, tolines, fromdesc='', todesc='',
               context=False, numlines=5, *, charset='utf-8')

          Compares 'fromlines' and 'tolines' (lists of strings) and
          returns a string which is a complete HTML file containing a
          table showing line by line differences with inter-line and
          intra-line changes highlighted.

          'fromdesc' and 'todesc' are optional keyword arguments to
          specify from/to file column header strings (both default to an
          empty string).

          'context' and 'numlines' are both optional keyword arguments.
          Set 'context' to ‘True’ when contextual differences are to be
          shown, else the default is ‘False’ to show the full files.
          'numlines' defaults to ‘5’.  When 'context' is ‘True’
          'numlines' controls the number of context lines which surround
          the difference highlights.  When 'context' is ‘False’
          'numlines' controls the number of lines which are shown before
          a difference highlight when using the «next» hyperlinks
          (setting to zero would cause the «next» hyperlinks to place
          the next difference highlight at the top of the browser
          without any leading context).

               Nota: 'fromdesc' and 'todesc' are interpreted as
               unescaped HTML and should be properly escaped while
               receiving input from untrusted sources.

          Cambiato nella versione 3.5: 'charset' keyword-only argument
          was added.  The default charset of HTML document changed from
          ‘'ISO-8859-1'’ to ‘'utf-8'’.

      -- Metodo: make_table (fromlines, tolines, fromdesc='', todesc='',
               context=False, numlines=5)

          Compares 'fromlines' and 'tolines' (lists of strings) and
          returns a string which is a complete HTML table showing line
          by line differences with inter-line and intra-line changes
          highlighted.

          The arguments for this method are the same as those for the
          *note make_file(): ff2. method.

 -- Funzione: difflib.context_diff (a, b, fromfile='', tofile='',
          fromfiledate='', tofiledate='', n=3, lineterm='\n')

     Compare 'a' and 'b' (lists of strings); return a delta (a *note
     generator: 1263. generating the delta lines) in context diff
     format.

     Context diffs are a compact way of showing just the lines that have
     changed plus a few lines of context.  The changes are shown in a
     before/after style.  The number of context lines is set by 'n'
     which defaults to three.

     By default, the diff control lines (those with ‘***’ or ‘---’) are
     created with a trailing newline.  This is helpful so that inputs
     created from *note io.IOBase.readlines(): 2784. result in diffs
     that are suitable for use with *note io.IOBase.writelines(): 1761.
     since both the inputs and outputs have trailing newlines.

     For inputs that do not have trailing newlines, set the 'lineterm'
     argument to ‘""’ so that the output will be uniformly newline free.

     The context diff format normally has a header for filenames and
     modification times.  Any or all of these may be specified using
     strings for 'fromfile', 'tofile', 'fromfiledate', and 'tofiledate'.
     The modification times are normally expressed in the ISO 8601
     format.  If not specified, the strings default to blanks.

          >>> import sys
          >>> from difflib import *
          >>> s1 = ['bacon\n', 'eggs\n', 'ham\n', 'guido\n']
          >>> s2 = ['python\n', 'eggy\n', 'hamster\n', 'guido\n']
          >>> sys.stdout.writelines(context_diff(s1, s2, fromfile='before.py',
          ...                        tofile='after.py'))
          *** before.py
          --- after.py
          ***************
          *** 1,4 ****
          ! bacon
          ! eggs
          ! ham
            guido
          --- 1,4 ----
          ! python
          ! eggy
          ! hamster
            guido

     See *note A command-line interface to difflib: 2785. for a more
     detailed example.

 -- Funzione: difflib.get_close_matches (word, possibilities, n=3,
          cutoff=0.6)

     Return a list of the best «good enough» matches.  'word' is a
     sequence for which close matches are desired (typically a string),
     and 'possibilities' is a list of sequences against which to match
     'word' (typically a list of strings).

     Optional argument 'n' (default ‘3’) is the maximum number of close
     matches to return; 'n' must be greater than ‘0’.

     Optional argument 'cutoff' (default ‘0.6’) is a float in the range
     [0, 1].  Possibilities that don’t score at least that similar to
     'word' are ignored.

     The best (no more than 'n') matches among the possibilities are
     returned in a list, sorted by similarity score, most similar first.

          >>> get_close_matches('appel', ['ape', 'apple', 'peach', 'puppy'])
          ['apple', 'ape']
          >>> import keyword
          >>> get_close_matches('wheel', keyword.kwlist)
          ['while']
          >>> get_close_matches('pineapple', keyword.kwlist)
          []
          >>> get_close_matches('accept', keyword.kwlist)
          ['except']

 -- Funzione: difflib.ndiff (a, b, linejunk=None,
          charjunk=IS_CHARACTER_JUNK)

     Compare 'a' and 'b' (lists of strings); return a *note Differ:
     2780.-style delta (a *note generator: 1263. generating the delta
     lines).

     Optional keyword parameters 'linejunk' and 'charjunk' are filtering
     functions (or ‘None’):

     'linejunk': A function that accepts a single string argument, and
     returns true if the string is junk, or false if not.  The default
     is ‘None’.  There is also a module-level function *note
     IS_LINE_JUNK(): 2d7, which filters out lines without visible
     characters, except for at most one hash character (‘'#'’) – however
     the underlying *note SequenceMatcher: 121b. class does a dynamic
     analysis of which lines are so frequent as to constitute noise, and
     this usually works better than using this function.

     'charjunk': A function that accepts a character (a string of length
     1), and returns if the character is junk, or false if not.  The
     default is module-level function *note IS_CHARACTER_JUNK(): 2787,
     which filters out whitespace characters (a blank or tab; it’s a bad
     idea to include newline in this!).

          >>> diff = ndiff('one\ntwo\nthree\n'.splitlines(keepends=True),
          ...              'ore\ntree\nemu\n'.splitlines(keepends=True))
          >>> print(''.join(diff), end="")
          - one
          ?  ^
          + ore
          ?  ^
          - two
          - three
          ?  -
          + tree
          + emu

 -- Funzione: difflib.restore (sequence, which)

     Return one of the two sequences that generated a delta.

     Given a 'sequence' produced by *note Differ.compare(): 2789. or
     *note ndiff(): 2782, extract lines originating from file 1 or 2
     (parameter 'which'), stripping off line prefixes.

     Example:

          >>> diff = ndiff('one\ntwo\nthree\n'.splitlines(keepends=True),
          ...              'ore\ntree\nemu\n'.splitlines(keepends=True))
          >>> diff = list(diff) # materialize the generated delta into a list
          >>> print(''.join(restore(diff, 1)), end="")
          one
          two
          three
          >>> print(''.join(restore(diff, 2)), end="")
          ore
          tree
          emu

 -- Funzione: difflib.unified_diff (a, b, fromfile='', tofile='',
          fromfiledate='', tofiledate='', n=3, lineterm='\n')

     Compare 'a' and 'b' (lists of strings); return a delta (a *note
     generator: 1263. generating the delta lines) in unified diff
     format.

     Unified diffs are a compact way of showing just the lines that have
     changed plus a few lines of context.  The changes are shown in an
     inline style (instead of separate before/after blocks).  The number
     of context lines is set by 'n' which defaults to three.

     By default, the diff control lines (those with ‘---’, ‘+++’, or
     ‘@@’) are created with a trailing newline.  This is helpful so that
     inputs created from *note io.IOBase.readlines(): 2784. result in
     diffs that are suitable for use with *note io.IOBase.writelines():
     1761. since both the inputs and outputs have trailing newlines.

     For inputs that do not have trailing newlines, set the 'lineterm'
     argument to ‘""’ so that the output will be uniformly newline free.

     The unified diff format normally has a header for filenames and
     modification times.  Any or all of these may be specified using
     strings for 'fromfile', 'tofile', 'fromfiledate', and 'tofiledate'.
     The modification times are normally expressed in the ISO 8601
     format.  If not specified, the strings default to blanks.

          >>> s1 = ['bacon\n', 'eggs\n', 'ham\n', 'guido\n']
          >>> s2 = ['python\n', 'eggy\n', 'hamster\n', 'guido\n']
          >>> sys.stdout.writelines(unified_diff(s1, s2, fromfile='before.py', tofile='after.py'))
          --- before.py
          +++ after.py
          @@ -1,4 +1,4 @@
          -bacon
          -eggs
          -ham
          +python
          +eggy
          +hamster
           guido

     See *note A command-line interface to difflib: 2785. for a more
     detailed example.

 -- Funzione: difflib.diff_bytes (dfunc, a, b, fromfile=b'', tofile=b'',
          fromfiledate=b'', tofiledate=b'', n=3, lineterm=b'\n')

     Compare 'a' and 'b' (lists of bytes objects) using 'dfunc'; yield a
     sequence of delta lines (also bytes) in the format returned by
     'dfunc'.  'dfunc' must be a callable, typically either *note
     unified_diff(): 196d. or *note context_diff(): 196e.

     Allows you to compare data with unknown or inconsistent encoding.
     All inputs except 'n' must be bytes objects, not str.  Works by
     losslessly converting all inputs (except 'n') to str, and calling
     ‘dfunc(a, b, fromfile, tofile, fromfiledate, tofiledate, n,
     lineterm)’.  The output of 'dfunc' is then converted back to bytes,
     so the delta lines that you receive have the same
     unknown/inconsistent encodings as 'a' and 'b'.

     Added in version 3.5.

 -- Funzione: difflib.IS_LINE_JUNK (line)

     Return ‘True’ for ignorable lines.  The line 'line' is ignorable if
     'line' is blank or contains a single ‘'#'’, otherwise it is not
     ignorable.  Used as a default for parameter 'linejunk' in *note
     ndiff(): 2782. in older versions.

 -- Funzione: difflib.IS_CHARACTER_JUNK (ch)

     Return ‘True’ for ignorable characters.  The character 'ch' is
     ignorable if 'ch' is a space or tab, otherwise it is not ignorable.
     Used as a default for parameter 'charjunk' in *note ndiff(): 2782.

Vedi anche
..........

Pattern Matching: The Gestalt Approach(2)

     Discussion of a similar algorithm by John W. Ratcliff and D. E.
     Metzener.  This was published in Dr.  Dobb’s Journal in July, 1988.

* Menu:

* SequenceMatcher Objects::
* SequenceMatcher Examples::
* Differ Objects::
* Differ Example::
* A command-line interface to difflib::
* ndiff example::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/difflib.py

   (2) 
https://jacobfilipp.com/DrDobbs/articles/DDJ/1988/8807/8807c/8807c.htm


File: python.info,  Node: SequenceMatcher Objects,  Next: SequenceMatcher Examples,  Up: difflib — Helpers for computing deltas

5.6.4.1 SequenceMatcher Objects
...............................

The *note SequenceMatcher: 121b. class has this constructor:

 -- Classe: difflib.SequenceMatcher (isjunk=None, a='', b='',
          autojunk=True)

     Optional argument 'isjunk' must be ‘None’ (the default) or a
     one-argument function that takes a sequence element and returns
     true if and only if the element is «junk» and should be ignored.
     Passing ‘None’ for 'isjunk' is equivalent to passing ‘lambda x:
     False’; in other words, no elements are ignored.  For example,
     pass:

          lambda x: x in " \t"

     if you’re comparing lines as sequences of characters, and don’t
     want to synch up on blanks or hard tabs.

     The optional arguments 'a' and 'b' are sequences to be compared;
     both default to empty strings.  The elements of both sequences must
     be *note hashable: 825.

     The optional argument 'autojunk' can be used to disable the
     automatic junk heuristic.

     Cambiato nella versione 3.2: Added the 'autojunk' parameter.

     SequenceMatcher objects get three data attributes: 'bjunk' is the
     set of elements of 'b' for which 'isjunk' is ‘True’; 'bpopular' is
     the set of non-junk elements considered popular by the heuristic
     (if it is not disabled); 'b2j' is a dict mapping the remaining
     elements of 'b' to a list of positions where they occur.  All three
     are reset whenever 'b' is reset with *note set_seqs(): 278c. or
     *note set_seq2(): 278d.

     Added in version 3.2: The 'bjunk' and 'bpopular' attributes.

     *note SequenceMatcher: 121b. objects have the following methods:

      -- Metodo: set_seqs (a, b)

          Set the two sequences to be compared.

     *note SequenceMatcher: 121b. computes and caches detailed
     information about the second sequence, so if you want to compare
     one sequence against many sequences, use *note set_seq2(): 278d. to
     set the commonly used sequence once and call *note set_seq1():
     278e. repeatedly, once for each of the other sequences.

      -- Metodo: set_seq1 (a)

          Set the first sequence to be compared.  The second sequence to
          be compared is not changed.

      -- Metodo: set_seq2 (b)

          Set the second sequence to be compared.  The first sequence to
          be compared is not changed.

      -- Metodo: find_longest_match (alo=0, ahi=None, blo=0, bhi=None)

          Find longest matching block in ‘a[alo:ahi]’ and ‘b[blo:bhi]’.

          If 'isjunk' was omitted or ‘None’, *note find_longest_match():
          1d33. returns ‘(i, j, k)’ such that ‘a[i:i+k]’ is equal to
          ‘b[j:j+k]’, where ‘alo <= i <= i+k <= ahi’ and ‘blo <= j <=
          j+k <= bhi’.  For all ‘(i', j', k')’ meeting those conditions,
          the additional conditions ‘k >= k'’, ‘i <= i'’, and if ‘i ==
          i'’, ‘j <= j'’ are also met.  In other words, of all maximal
          matching blocks, return one that starts earliest in 'a', and
          of all those maximal matching blocks that start earliest in
          'a', return the one that starts earliest in 'b'.

               >>> s = SequenceMatcher(None, " abcd", "abcd abcd")
               >>> s.find_longest_match(0, 5, 0, 9)
               Match(a=0, b=4, size=5)

          If 'isjunk' was provided, first the longest matching block is
          determined as above, but with the additional restriction that
          no junk element appears in the block.  Then that block is
          extended as far as possible by matching (only) junk elements
          on both sides.  So the resulting block never matches on junk
          except as identical junk happens to be adjacent to an
          interesting match.

          Here’s the same example as before, but considering blanks to
          be junk.  That prevents ‘' abcd'’ from matching the ‘' abcd'’
          at the tail end of the second sequence directly.  Instead only
          the ‘'abcd'’ can match, and matches the leftmost ‘'abcd'’ in
          the second sequence:

               >>> s = SequenceMatcher(lambda x: x==" ", " abcd", "abcd abcd")
               >>> s.find_longest_match(0, 5, 0, 9)
               Match(a=1, b=0, size=4)

          If no blocks match, this returns ‘(alo, blo, 0)’.

          This method returns a *note named tuple: 85f. ‘Match(a, b,
          size)’.

          Cambiato nella versione 3.9: Added default arguments.

      -- Metodo: get_matching_blocks ()

          Return list of triples describing non-overlapping matching
          subsequences.  Each triple is of the form ‘(i, j, n)’, and
          means that ‘a[i:i+n] == b[j:j+n]’.  The triples are
          monotonically increasing in 'i' and 'j'.

          The last triple is a dummy, and has the value ‘(len(a),
          len(b), 0)’.  It is the only triple with ‘n == 0’.  If ‘(i, j,
          n)’ and ‘(i', j', n')’ are adjacent triples in the list, and
          the second is not the last triple in the list, then ‘i+n < i'’
          or ‘j+n < j'’; in other words, adjacent triples always
          describe non-adjacent equal blocks.

               >>> s = SequenceMatcher(None, "abxcd", "abcd")
               >>> s.get_matching_blocks()
               [Match(a=0, b=0, size=2), Match(a=3, b=2, size=2), Match(a=5, b=4, size=0)]

      -- Metodo: get_opcodes ()

          Return list of 5-tuples describing how to turn 'a' into 'b'.
          Each tuple is of the form ‘(tag, i1, i2, j1, j2)’.  The first
          tuple has ‘i1 == j1 == 0’, and remaining tuples have 'i1'
          equal to the 'i2' from the preceding tuple, and, likewise,
          'j1' equal to the previous 'j2'.

          The 'tag' values are strings, with these meanings:

          Value               Meaning
                              
          ----------------------------------------------------------------------
                              
          ‘'replace'’         ‘a[i1:i2]’ should be replaced by ‘b[j1:j2]’.
                              
                              
          ‘'delete'’          ‘a[i1:i2]’ should be deleted.  Note that ‘j1 ==
                              j2’ in this case.
                              
                              
          ‘'insert'’          ‘b[j1:j2]’ should be inserted at ‘a[i1:i1]’.
                              Note that ‘i1 == i2’ in this case.
                              
                              
          ‘'equal'’           ‘a[i1:i2] == b[j1:j2]’ (the sub-sequences are
                              equal).
                              

          For example:

               >>> a = "qabxcd"
               >>> b = "abycdf"
               >>> s = SequenceMatcher(None, a, b)
               >>> for tag, i1, i2, j1, j2 in s.get_opcodes():
               ...     print('{:7}   a[{}:{}] --> b[{}:{}] {!r:>8} --> {!r}'.format(
               ...         tag, i1, i2, j1, j2, a[i1:i2], b[j1:j2]))
               delete    a[0:1] --> b[0:0]      'q' --> ''
               equal     a[1:3] --> b[0:2]     'ab' --> 'ab'
               replace   a[3:4] --> b[2:3]      'x' --> 'y'
               equal     a[4:6] --> b[3:5]     'cd' --> 'cd'
               insert    a[6:6] --> b[5:6]       '' --> 'f'

      -- Metodo: get_grouped_opcodes (n=3)

          Return a *note generator: 1263. of groups with up to 'n' lines
          of context.

          Starting with the groups returned by *note get_opcodes():
          2790, this method splits out smaller change clusters and
          eliminates intervening ranges which have no changes.

          The groups are returned in the same format as *note
          get_opcodes(): 2790.

      -- Metodo: ratio ()

          Return a measure of the sequences” similarity as a float in
          the range [0, 1].

          Where T is the total number of elements in both sequences, and
          M is the number of matches, this is 2.0*M / T. Note that this
          is ‘1.0’ if the sequences are identical, and ‘0.0’ if they
          have nothing in common.

          This is expensive to compute if *note get_matching_blocks():
          278f. or *note get_opcodes(): 2790. hasn’t already been
          called, in which case you may want to try *note quick_ratio():
          2793. or *note real_quick_ratio(): 2794. first to get an upper
          bound.

               Nota: Caution: The result of a *note ratio(): 2792. call
               may depend on the order of the arguments.  For instance:

                    >>> SequenceMatcher(None, 'tide', 'diet').ratio()
                    0.25
                    >>> SequenceMatcher(None, 'diet', 'tide').ratio()
                    0.5

      -- Metodo: quick_ratio ()

          Return an upper bound on *note ratio(): 2792. relatively
          quickly.

      -- Metodo: real_quick_ratio ()

          Return an upper bound on *note ratio(): 2792. very quickly.

The three methods that return the ratio of matching to total characters
can give different results due to differing levels of approximation,
although *note quick_ratio(): 2793. and *note real_quick_ratio(): 2794.
are always at least as large as *note ratio(): 2792.:

     >>> s = SequenceMatcher(None, "abcd", "bcde")
     >>> s.ratio()
     0.75
     >>> s.quick_ratio()
     0.75
     >>> s.real_quick_ratio()
     1.0


File: python.info,  Node: SequenceMatcher Examples,  Next: Differ Objects,  Prev: SequenceMatcher Objects,  Up: difflib — Helpers for computing deltas

5.6.4.2 SequenceMatcher Examples
................................

This example compares two strings, considering blanks to be «junk»:

     >>> s = SequenceMatcher(lambda x: x == " ",
     ...                     "private Thread currentThread;",
     ...                     "private volatile Thread currentThread;")

*note ratio(): 2792. returns a float in [0, 1], measuring the similarity
of the sequences.  As a rule of thumb, a *note ratio(): 2792. value over
0.6 means the sequences are close matches:

     >>> print(round(s.ratio(), 3))
     0.866

If you’re only interested in where the sequences match, *note
get_matching_blocks(): 278f. is handy:

     >>> for block in s.get_matching_blocks():
     ...     print("a[%d] and b[%d] match for %d elements" % block)
     a[0] and b[0] match for 8 elements
     a[8] and b[17] match for 21 elements
     a[29] and b[38] match for 0 elements

Note that the last tuple returned by *note get_matching_blocks(): 278f.
is always a dummy, ‘(len(a), len(b), 0)’, and this is the only case in
which the last tuple element (number of elements matched) is ‘0’.

If you want to know how to change the first sequence into the second,
use *note get_opcodes(): 2790.:

     >>> for opcode in s.get_opcodes():
     ...     print("%6s a[%d:%d] b[%d:%d]" % opcode)
      equal a[0:8] b[0:8]
     insert a[8:8] b[8:17]
      equal a[8:29] b[17:38]

Vedi anche
..........

   * The *note get_close_matches(): 2786. function in this module which
     shows how simple code building on *note SequenceMatcher: 121b. can
     be used to do useful work.

   * Simple version control recipe(1) for a small application built with
     *note SequenceMatcher: 121b.

   ---------- Footnotes ----------

   (1) 
https://code.activestate.com/recipes/576729-simple-version-control/


File: python.info,  Node: Differ Objects,  Next: Differ Example,  Prev: SequenceMatcher Examples,  Up: difflib — Helpers for computing deltas

5.6.4.3 Differ Objects
......................

Note that *note Differ: 2780.-generated deltas make no claim to be
'minimal' diffs.  To the contrary, minimal diffs are often
counter-intuitive, because they synch up anywhere possible, sometimes
accidental matches 100 pages apart.  Restricting synch points to
contiguous matches preserves some notion of locality, at the occasional
cost of producing a longer diff.

The *note Differ: 2780. class has this constructor:

 -- Classe: difflib.Differ (linejunk=None, charjunk=None)

     Optional keyword parameters 'linejunk' and 'charjunk' are for
     filter functions (or ‘None’):

     'linejunk': A function that accepts a single string argument, and
     returns true if the string is junk.  The default is ‘None’, meaning
     that no line is considered junk.

     'charjunk': A function that accepts a single character argument (a
     string of length 1), and returns true if the character is junk.
     The default is ‘None’, meaning that no character is considered
     junk.

     These junk-filtering functions speed up matching to find
     differences and do not cause any differing lines or characters to
     be ignored.  Read the description of the *note
     find_longest_match(): 1d33. method’s 'isjunk' parameter for an
     explanation.

     *note Differ: 2780. objects are used (deltas generated) via a
     single method:

      -- Metodo: compare (a, b)

          Compare two sequences of lines, and generate the delta (a
          sequence of lines).

          Each sequence must contain individual single-line strings
          ending with newlines.  Such sequences can be obtained from the
          *note readlines(): 2784. method of file-like objects.  The
          delta generated also consists of newline-terminated strings,
          ready to be printed as-is via the *note writelines(): 1761.
          method of a file-like object.


File: python.info,  Node: Differ Example,  Next: A command-line interface to difflib,  Prev: Differ Objects,  Up: difflib — Helpers for computing deltas

5.6.4.4 Differ Example
......................

This example compares two texts.  First we set up the texts, sequences
of individual single-line strings ending with newlines (such sequences
can also be obtained from the *note readlines(): 2784. method of
file-like objects):

     >>> text1 = '''  1. Beautiful is better than ugly.
     ...   2. Explicit is better than implicit.
     ...   3. Simple is better than complex.
     ...   4. Complex is better than complicated.
     ... '''.splitlines(keepends=True)
     >>> len(text1)
     4
     >>> text1[0][-1]
     '\n'
     >>> text2 = '''  1. Beautiful is better than ugly.
     ...   3.   Simple is better than complex.
     ...   4. Complicated is better than complex.
     ...   5. Flat is better than nested.
     ... '''.splitlines(keepends=True)

Next we instantiate a Differ object:

     >>> d = Differ()

Note that when instantiating a *note Differ: 2780. object we may pass
functions to filter out line and character «junk.» See the *note
Differ(): 2780. constructor for details.

Finally, we compare the two:

     >>> result = list(d.compare(text1, text2))

‘result’ is a list of strings, so let’s pretty-print it:

     >>> from pprint import pprint
     >>> pprint(result)
     ['    1. Beautiful is better than ugly.\n',
      '-   2. Explicit is better than implicit.\n',
      '-   3. Simple is better than complex.\n',
      '+   3.   Simple is better than complex.\n',
      '?     ++\n',
      '-   4. Complex is better than complicated.\n',
      '?            ^                     ---- ^\n',
      '+   4. Complicated is better than complex.\n',
      '?           ++++ ^                      ^\n',
      '+   5. Flat is better than nested.\n']

As a single multi-line string it looks like this:

     >>> import sys
     >>> sys.stdout.writelines(result)
         1. Beautiful is better than ugly.
     -   2. Explicit is better than implicit.
     -   3. Simple is better than complex.
     +   3.   Simple is better than complex.
     ?     ++
     -   4. Complex is better than complicated.
     ?            ^                     ---- ^
     +   4. Complicated is better than complex.
     ?           ++++ ^                      ^
     +   5. Flat is better than nested.


File: python.info,  Node: A command-line interface to difflib,  Next: ndiff example,  Prev: Differ Example,  Up: difflib — Helpers for computing deltas

5.6.4.5 A command-line interface to difflib
...........................................

This example shows how to use difflib to create a ‘diff’-like utility.

     """ Command line interface to difflib.py providing diffs in four formats:

     * ndiff:    lists every line and highlights interline changes.
     * context:  highlights clusters of changes in a before/after format.
     * unified:  highlights clusters of changes in an inline format.
     * html:     generates side by side comparison with change highlights.

     """

     import sys, os, difflib, argparse
     from datetime import datetime, timezone

     def file_mtime(path):
         t = datetime.fromtimestamp(os.stat(path).st_mtime,
                                    timezone.utc)
         return t.astimezone().isoformat()

     def main():

         parser = argparse.ArgumentParser()
         parser.add_argument('-c', action='store_true', default=False,
                             help='Produce a context format diff (default)')
         parser.add_argument('-u', action='store_true', default=False,
                             help='Produce a unified format diff')
         parser.add_argument('-m', action='store_true', default=False,
                             help='Produce HTML side by side diff '
                                  '(can use -c and -l in conjunction)')
         parser.add_argument('-n', action='store_true', default=False,
                             help='Produce a ndiff format diff')
         parser.add_argument('-l', '--lines', type=int, default=3,
                             help='Set number of context lines (default 3)')
         parser.add_argument('fromfile')
         parser.add_argument('tofile')
         options = parser.parse_args()

         n = options.lines
         fromfile = options.fromfile
         tofile = options.tofile

         fromdate = file_mtime(fromfile)
         todate = file_mtime(tofile)
         with open(fromfile) as ff:
             fromlines = ff.readlines()
         with open(tofile) as tf:
             tolines = tf.readlines()

         if options.u:
             diff = difflib.unified_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
         elif options.n:
             diff = difflib.ndiff(fromlines, tolines)
         elif options.m:
             diff = difflib.HtmlDiff().make_file(fromlines,tolines,fromfile,tofile,context=options.c,numlines=n)
         else:
             diff = difflib.context_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)

         sys.stdout.writelines(diff)

     if __name__ == '__main__':
         main()


File: python.info,  Node: ndiff example,  Prev: A command-line interface to difflib,  Up: difflib — Helpers for computing deltas

5.6.4.6 ndiff example
.....................

This example shows how to use *note difflib.ndiff(): 2782.

     """ndiff [-q] file1 file2
         or
     ndiff (-r1 | -r2) < ndiff_output > file1_or_file2

     Print a human-friendly file difference report to stdout.  Both inter-
     and intra-line differences are noted.  In the second form, recreate file1
     (-r1) or file2 (-r2) on stdout, from an ndiff report on stdin.

     In the first form, if -q ("quiet") is not specified, the first two lines
     of output are

     -: file1
     +: file2

     Each remaining line begins with a two-letter code:

         "- "    line unique to file1
         "+ "    line unique to file2
         "  "    line common to both files
         "? "    line not present in either input file

     Lines beginning with "? " attempt to guide the eye to intraline
     differences, and were not present in either input file.  These lines can be
     confusing if the source files contain tab characters.

     The first file can be recovered by retaining only lines that begin with
     "  " or "- ", and deleting those 2-character prefixes; use ndiff with -r1.

     The second file can be recovered similarly, but by retaining only "  " and
     "+ " lines; use ndiff with -r2; or, on Unix, the second file can be
     recovered by piping the output through

         sed -n '/^[+ ] /s/^..//p'
     """

     __version__ = 1, 7, 0

     import difflib, sys

     def fail(msg):
         out = sys.stderr.write
         out(msg + "\n\n")
         out(__doc__)
         return 0

     # open a file & return the file object; gripe and return 0 if it
     # couldn't be opened
     def fopen(fname):
         try:
             return open(fname)
         except IOError as detail:
             return fail("couldn't open " + fname + ": " + str(detail))

     # open two files & spray the diff to stdout; return false iff a problem
     def fcompare(f1name, f2name):
         f1 = fopen(f1name)
         f2 = fopen(f2name)
         if not f1 or not f2:
             return 0

         a = f1.readlines(); f1.close()
         b = f2.readlines(); f2.close()
         for line in difflib.ndiff(a, b):
             print(line, end=' ')

         return 1

     # crack args (sys.argv[1:] is normal) & compare;
     # return false iff a problem

     def main(args):
         import getopt
         try:
             opts, args = getopt.getopt(args, "qr:")
         except getopt.error as detail:
             return fail(str(detail))
         noisy = 1
         qseen = rseen = 0
         for opt, val in opts:
             if opt == "-q":
                 qseen = 1
                 noisy = 0
             elif opt == "-r":
                 rseen = 1
                 whichfile = val
         if qseen and rseen:
             return fail("can't specify both -q and -r")
         if rseen:
             if args:
                 return fail("no args allowed with -r option")
             if whichfile in ("1", "2"):
                 restore(whichfile)
                 return 1
             return fail("-r value must be 1 or 2")
         if len(args) != 2:
             return fail("need 2 filename args")
         f1name, f2name = args
         if noisy:
             print('-:', f1name)
             print('+:', f2name)
         return fcompare(f1name, f2name)

     # read ndiff output from stdin, and print file1 (which=='1') or
     # file2 (which=='2') to stdout

     def restore(which):
         restored = difflib.restore(sys.stdin.readlines(), which)
         sys.stdout.writelines(restored)

     if __name__ == '__main__':
         main(sys.argv[1:])


File: python.info,  Node: textwrap — Text wrapping and filling,  Next: unicodedata — Unicode Database,  Prev: difflib — Helpers for computing deltas,  Up: Text Processing Services

5.6.5 ‘textwrap’ — Text wrapping and filling
--------------------------------------------

'Source code:' Lib/textwrap.py(1)

__________________________________________________________________

The *note textwrap: f2. module provides some convenience functions, as
well as *note TextWrapper: 11cf, the class that does all the work.  If
you’re just wrapping or filling one or two text strings, the convenience
functions should be good enough; otherwise, you should use an instance
of *note TextWrapper: 11cf. for efficiency.

 -- Funzione: textwrap.wrap (text, width=70, *, initial_indent='',
          subsequent_indent='', expand_tabs=True,
          replace_whitespace=True, fix_sentence_endings=False,
          break_long_words=True, drop_whitespace=True,
          break_on_hyphens=True, tabsize=8, max_lines=None,
          placeholder=' [...]')

     Wraps the single paragraph in 'text' (a string) so every line is at
     most 'width' characters long.  Returns a list of output lines,
     without final newlines.

     Optional keyword arguments correspond to the instance attributes of
     *note TextWrapper: 11cf, documented below.

     See the *note TextWrapper.wrap(): 27a0. method for additional
     details on how *note wrap(): 16ce. behaves.

 -- Funzione: textwrap.fill (text, width=70, *, initial_indent='',
          subsequent_indent='', expand_tabs=True,
          replace_whitespace=True, fix_sentence_endings=False,
          break_long_words=True, drop_whitespace=True,
          break_on_hyphens=True, tabsize=8, max_lines=None,
          placeholder=' [...]')

     Wraps the single paragraph in 'text', and returns a single string
     containing the wrapped paragraph.  *note fill(): 16cd. is shorthand
     for

          "\n".join(wrap(text, ...))

     In particular, *note fill(): 16cd. accepts exactly the same keyword
     arguments as *note wrap(): 16ce.

 -- Funzione: textwrap.shorten (text, width, *,
          fix_sentence_endings=False, break_long_words=True,
          break_on_hyphens=True, placeholder=' [...]')

     Collapse and truncate the given 'text' to fit in the given 'width'.

     First the whitespace in 'text' is collapsed (all whitespace is
     replaced by single spaces).  If the result fits in the 'width', it
     is returned.  Otherwise, enough words are dropped from the end so
     that the remaining words plus the 'placeholder' fit within 'width':

          >>> textwrap.shorten("Hello  world!", width=12)
          'Hello world!'
          >>> textwrap.shorten("Hello  world!", width=11)
          'Hello [...]'
          >>> textwrap.shorten("Hello world", width=10, placeholder="...")
          'Hello...'

     Optional keyword arguments correspond to the instance attributes of
     *note TextWrapper: 11cf, documented below.  Note that the
     whitespace is collapsed before the text is passed to the *note
     TextWrapper: 11cf. *note fill(): 16cd. function, so changing the
     value of *note tabsize: 27a1, *note expand_tabs: 27a2, *note
     drop_whitespace: 27a3, and *note replace_whitespace: 27a4. will
     have no effect.

     Added in version 3.4.

 -- Funzione: textwrap.dedent (text)

     Remove any common leading whitespace from every line in 'text'.

     This can be used to make triple-quoted strings line up with the
     left edge of the display, while still presenting them in the source
     code in indented form.

     Note that tabs and spaces are both treated as whitespace, but they
     are not equal: the lines ‘" hello"’ and ‘"\thello"’ are considered
     to have no common leading whitespace.

     Lines containing only whitespace are ignored in the input and
     normalized to a single newline character in the output.

     For example:

          def test():
              # end first line with \ to avoid the empty line!
              s = '''\
              hello
                world
              '''
              print(repr(s))          # prints '    hello\n      world\n    '
              print(repr(dedent(s)))  # prints 'hello\n  world\n'

     Cambiato nella versione 3.14: The ‘dedent()’ function now correctly
     normalizes blank lines containing only whitespace characters.
     Previously, the implementation only normalized blank lines
     containing tabs and spaces.

 -- Funzione: textwrap.indent (text, prefix, predicate=None)

     Add 'prefix' to the beginning of selected lines in 'text'.

     Lines are separated by calling ‘text.splitlines(True)’.

     By default, 'prefix' is added to all lines that do not consist
     solely of whitespace (including any line endings).

     For example:

          >>> s = 'hello\n\n \nworld'
          >>> indent(s, '  ')
          '  hello\n\n \n  world'

     The optional 'predicate' argument can be used to control which
     lines are indented.  For example, it is easy to add 'prefix' to
     even empty and whitespace-only lines:

          >>> print(indent(s, '+ ', lambda line: True))
          + hello
          +
          +
          + world

     Added in version 3.3.

*note wrap(): 16ce, *note fill(): 16cd. and *note shorten(): 11d2. work
by creating a *note TextWrapper: 11cf. instance and calling a single
method on it.  That instance is not reused, so for applications that
process many text strings using *note wrap(): 16ce. and/or *note fill():
16cd, it may be more efficient to create your own *note TextWrapper:
11cf. object.

Text is preferably wrapped on whitespaces and right after the hyphens in
hyphenated words; only then will long words be broken if necessary,
unless *note TextWrapper.break_long_words: 27a5. is set to false.

 -- Classe: textwrap.TextWrapper (**kwargs)

     The *note TextWrapper: 11cf. constructor accepts a number of
     optional keyword arguments.  Each keyword argument corresponds to
     an instance attribute, so for example

          wrapper = TextWrapper(initial_indent="* ")

     is the same as

          wrapper = TextWrapper()
          wrapper.initial_indent = "* "

     You can reuse the same *note TextWrapper: 11cf. object many times,
     and you can change any of its options through direct assignment to
     instance attributes between uses.

     The *note TextWrapper: 11cf. instance attributes (and keyword
     arguments to the constructor) are as follows:

      -- Attributo: width

          (default: ‘70’) The maximum length of wrapped lines.  As long
          as there are no individual words in the input text longer than
          *note width: 27a6, *note TextWrapper: 11cf. guarantees that no
          output line will be longer than *note width: 27a6. characters.

      -- Attributo: expand_tabs

          (default: ‘True’) If true, then all tab characters in 'text'
          will be expanded to spaces using the *note expandtabs(): 2623.
          method of 'text'.

      -- Attributo: tabsize

          (default: ‘8’) If *note expand_tabs: 27a2. is true, then all
          tab characters in 'text' will be expanded to zero or more
          spaces, depending on the current column and the given tab
          size.

          Added in version 3.3.

      -- Attributo: replace_whitespace

          (default: ‘True’) If true, after tab expansion but before
          wrapping, the *note wrap(): 16ce. method will replace each
          whitespace character with a single space.  The whitespace
          characters replaced are as follows: tab, newline, vertical
          tab, formfeed, and carriage return (‘'\t\n\v\f\r'’).

               Nota: If *note expand_tabs: 27a2. is false and *note
               replace_whitespace: 27a4. is true, each tab character
               will be replaced by a single space, which is 'not' the
               same as tab expansion.

               Nota: If *note replace_whitespace: 27a4. is false,
               newlines may appear in the middle of a line and cause
               strange output.  For this reason, text should be split
               into paragraphs (using *note str.splitlines(): 145e. or
               similar) which are wrapped separately.

      -- Attributo: drop_whitespace

          (default: ‘True’) If true, whitespace at the beginning and
          ending of every line (after wrapping but before indenting) is
          dropped.  Whitespace at the beginning of the paragraph,
          however, is not dropped if non-whitespace follows it.  If
          whitespace being dropped takes up an entire line, the whole
          line is dropped.

      -- Attributo: initial_indent

          (default: ‘''’) String that will be prepended to the first
          line of wrapped output.  Counts towards the length of the
          first line.  The empty string is not indented.

      -- Attributo: subsequent_indent

          (default: ‘''’) String that will be prepended to all lines of
          wrapped output except the first.  Counts towards the length of
          each line except the first.

      -- Attributo: fix_sentence_endings

          (default: ‘False’) If true, *note TextWrapper: 11cf. attempts
          to detect sentence endings and ensure that sentences are
          always separated by exactly two spaces.  This is generally
          desired for text in a monospaced font.  However, the sentence
          detection algorithm is imperfect: it assumes that a sentence
          ending consists of a lowercase letter followed by one of
          ‘'.'’, ‘'!'’, or ‘'?'’, possibly followed by one of ‘'"'’ or
          ‘"'"’, followed by a space.  One problem with this algorithm
          is that it is unable to detect the difference between «Dr.» in

               [...] Dr. Frankenstein's monster [...]

          and «Spot.» in

               [...] See Spot. See Spot run [...]

          *note fix_sentence_endings: 27a9. is false by default.

          Since the sentence detection algorithm relies on
          ‘string.lowercase’ for the definition of «lowercase letter»,
          and a convention of using two spaces after a period to
          separate sentences on the same line, it is specific to
          English-language texts.

      -- Attributo: break_long_words

          (default: ‘True’) If true, then words longer than *note width:
          27a6. will be broken in order to ensure that no lines are
          longer than *note width: 27a6.  If it is false, long words
          will not be broken, and some lines may be longer than *note
          width: 27a6.  (Long words will be put on a line by themselves,
          in order to minimize the amount by which *note width: 27a6. is
          exceeded.)

      -- Attributo: break_on_hyphens

          (default: ‘True’) If true, wrapping will occur preferably on
          whitespaces and right after hyphens in compound words, as it
          is customary in English.  If false, only whitespaces will be
          considered as potentially good places for line breaks, but you
          need to set *note break_long_words: 27a5. to false if you want
          truly insecable words.  Default behaviour in previous versions
          was to always allow breaking hyphenated words.

      -- Attributo: max_lines

          (default: ‘None’) If not ‘None’, then the output will contain
          at most 'max_lines' lines, with 'placeholder' appearing at the
          end of the output.

          Added in version 3.4.

      -- Attributo: placeholder

          (default: ‘' [...]'’) String that will appear at the end of
          the output text if it has been truncated.

          Added in version 3.4.

     *note TextWrapper: 11cf. also provides some public methods,
     analogous to the module-level convenience functions:

      -- Metodo: wrap (text)

          Wraps the single paragraph in 'text' (a string) so every line
          is at most *note width: 27a6. characters long.  All wrapping
          options are taken from instance attributes of the *note
          TextWrapper: 11cf. instance.  Returns a list of output lines,
          without final newlines.  If the wrapped output has no content,
          the returned list is empty.

      -- Metodo: fill (text)

          Wraps the single paragraph in 'text', and returns a single
          string containing the wrapped paragraph.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/textwrap.py


File: python.info,  Node: unicodedata — Unicode Database,  Next: stringprep — Internet String Preparation,  Prev: textwrap — Text wrapping and filling,  Up: Text Processing Services

5.6.6 ‘unicodedata’ — Unicode Database
--------------------------------------

__________________________________________________________________

This module provides access to the Unicode Character Database (UCD)
which defines character properties for all Unicode characters.  The data
contained in this database is compiled from the UCD version 16.0.0(1).

The module uses the same names and symbols as defined by Unicode
Standard Annex #44, "Unicode Character Database"(2).  It defines the
following functions:

Vedi anche
..........

The *note Unicode HOWTO: 14ac. for more information about Unicode and
how to use this module.

 -- Funzione: unicodedata.lookup (name)

     Look up character by name.  If a character with the given name is
     found, return the corresponding character.  If not found, *note
     KeyError: 5e7. is raised.  For example:

          >>> unicodedata.lookup('LEFT CURLY BRACKET')
          '{'

     The characters returned by this function are the same as those
     produced by ‘\N’ escape sequence in string literals.  For example:

          >>> unicodedata.lookup('MIDDLE DOT') == '\N{MIDDLE DOT}'
          True

     Cambiato nella versione 3.3: Support for name aliases (3) and named
     sequences (4) has been added.

 -- Funzione: unicodedata.name (chr, default=None, /)

     Returns the name assigned to the character 'chr' as a string.  If
     no name is defined, 'default' is returned, or, if not given, *note
     ValueError: 2ec. is raised.  For example:

          >>> unicodedata.name('½')
          'VULGAR FRACTION ONE HALF'
          >>> unicodedata.name('\uFFFF', 'fallback')
          'fallback'

 -- Funzione: unicodedata.decimal (chr, default=None, /)

     Returns the decimal value assigned to the character 'chr' as
     integer.  If no such value is defined, 'default' is returned, or,
     if not given, *note ValueError: 2ec. is raised.  For example:

          >>> unicodedata.decimal('\N{ARABIC-INDIC DIGIT NINE}')
          9
          >>> unicodedata.decimal('\N{SUPERSCRIPT NINE}', -1)
          -1

 -- Funzione: unicodedata.digit (chr, default=None, /)

     Returns the digit value assigned to the character 'chr' as integer.
     If no such value is defined, 'default' is returned, or, if not
     given, *note ValueError: 2ec. is raised:

          >>> unicodedata.digit('\N{SUPERSCRIPT NINE}')
          9

 -- Funzione: unicodedata.numeric (chr, default=None, /)

     Returns the numeric value assigned to the character 'chr' as float.
     If no such value is defined, 'default' is returned, or, if not
     given, *note ValueError: 2ec. is raised:

          >>> unicodedata.numeric('½')
          0.5

 -- Funzione: unicodedata.category (chr)

     Returns the general category assigned to the character 'chr' as
     string.  General category names consist of two letters.  See the
     General Category Values section of the Unicode Character Database
     documentation(5) for a list of category codes.  For example:

          >>> unicodedata.category('A')  # 'L'etter, 'u'ppercase
          'Lu'

 -- Funzione: unicodedata.bidirectional (chr)

     Returns the bidirectional class assigned to the character 'chr' as
     string.  If no such value is defined, an empty string is returned.
     See the Bidirectional Class Values section of the Unicode Character
     Database(6) documentation for a list of bidirectional codes.  For
     example:

          >>> unicodedata.bidirectional('\N{ARABIC-INDIC DIGIT SEVEN}') # 'A'rabic, 'N'umber
          'AN'

 -- Funzione: unicodedata.combining (chr)

     Returns the canonical combining class assigned to the character
     'chr' as integer.  Returns ‘0’ if no combining class is defined.
     See the Canonical Combining Class Values section of the Unicode
     Character Database(7) for more information.

 -- Funzione: unicodedata.east_asian_width (chr)

     Returns the east asian width assigned to the character 'chr' as
     string.  For a list of widths and or more information, see the
     Unicode Standard Annex #11(8).

 -- Funzione: unicodedata.mirrored (chr)

     Returns the mirrored property assigned to the character 'chr' as
     integer.  Returns ‘1’ if the character has been identified as a
     «mirrored» character in bidirectional text, ‘0’ otherwise.  For
     example:

          >>> unicodedata.mirrored('>')
          1

 -- Funzione: unicodedata.decomposition (chr)

     Returns the character decomposition mapping assigned to the
     character 'chr' as string.  An empty string is returned in case no
     such mapping is defined.  For example:

          >>> unicodedata.decomposition('Ã')
          '0041 0303'

 -- Funzione: unicodedata.normalize (form, unistr)

     Return the normal form 'form' for the Unicode string 'unistr'.
     Valid values for 'form' are “NFC”, “NFKC”, “NFD”, and “NFKD”.

     The Unicode standard defines various normalization forms of a
     Unicode string, based on the definition of canonical equivalence
     and compatibility equivalence.  In Unicode, several characters can
     be expressed in various way.  For example, the character U+00C7
     (LATIN CAPITAL LETTER C WITH CEDILLA) can also be expressed as the
     sequence U+0043 (LATIN CAPITAL LETTER C) U+0327 (COMBINING
     CEDILLA).

     For each character, there are two normal forms: normal form C and
     normal form D. Normal form D (NFD) is also known as canonical
     decomposition, and translates each character into its decomposed
     form.  Normal form C (NFC) first applies a canonical decomposition,
     then composes pre-combined characters again.

     In addition to these two forms, there are two additional normal
     forms based on compatibility equivalence.  In Unicode, certain
     characters are supported which normally would be unified with other
     characters.  For example, U+2160 (ROMAN NUMERAL ONE) is really the
     same thing as U+0049 (LATIN CAPITAL LETTER I). However, it is
     supported in Unicode for compatibility with existing character sets
     (for example, gb2312).

     The normal form KD (NFKD) will apply the compatibility
     decomposition, that is, replace all compatibility characters with
     their equivalents.  The normal form KC (NFKC) first applies the
     compatibility decomposition, followed by the canonical composition.

     Even if two unicode strings are normalized and look the same to a
     human reader, if one has combining characters and the other
     doesn’t, they may not compare equal.

 -- Funzione: unicodedata.is_normalized (form, unistr)

     Return whether the Unicode string 'unistr' is in the normal form
     'form'.  Valid values for 'form' are “NFC”, “NFKC”, “NFD”, and
     “NFKD”.

     Added in version 3.8.

In addition, the module exposes the following constant:

 -- Dati: unicodedata.unidata_version

     The version of the Unicode database used in this module.

 -- Dati: unicodedata.ucd_3_2_0

     This is an object that has the same methods as the entire module,
     but uses the Unicode database version 3.2 instead, for applications
     that require this specific version of the Unicode database (such as
     IDNA).

   ---------- Footnotes ----------

   (1) https://www.unicode.org/Public/16.0.0/ucd

   (2) https://www.unicode.org/reports/tr44/

   (3) ‘https://www.unicode.org/Public/16.0.0/ucd/NameAliases.txt’

   (4) ‘https://www.unicode.org/Public/16.0.0/ucd/NamedSequences.txt’

   (5) 
https://www.unicode.org/reports/tr44/tr44-34.html#General_Category_Values

   (6) 
https://www.unicode.org/reports/tr44/tr44-34.html#Bidi_Class_Values

   (7) 
https://www.unicode.org/reports/tr44/tr44-34.html#Canonical_Combining_Class_Values

   (8) https://www.unicode.org/reports/tr11/tr11-43.html


File: python.info,  Node: stringprep — Internet String Preparation,  Next: readline — GNU readline interface,  Prev: unicodedata — Unicode Database,  Up: Text Processing Services

5.6.7 ‘stringprep’ — Internet String Preparation
------------------------------------------------

'Source code:' Lib/stringprep.py(1)

__________________________________________________________________

When identifying things (such as host names) in the internet, it is
often necessary to compare such identifications for «equality».  Exactly
how this comparison is executed may depend on the application domain,
e.g.  whether it should be case-insensitive or not.  It may be also
necessary to restrict the possible identifications, to allow only
identifications consisting of «printable» characters.

RFC 3454(2) defines a procedure for «preparing» Unicode strings in
internet protocols.  Before passing strings onto the wire, they are
processed with the preparation procedure, after which they have a
certain normalized form.  The RFC defines a set of tables, which can be
combined into profiles.  Each profile must define which tables it uses,
and what other optional parts of the ‘stringprep’ procedure are part of
the profile.  One example of a ‘stringprep’ profile is ‘nameprep’, which
is used for internationalized domain names.

The module *note stringprep: da. only exposes the tables from RFC
3454(3).  As these tables would be very large to represent as
dictionaries or lists, the module uses the Unicode character database
internally.  The module source code itself was generated using the
‘mkstringprep.py’ utility.

As a result, these tables are exposed as functions, not as data
structures.  There are two kinds of tables in the RFC: sets and
mappings.  For a set, *note stringprep: da. provides the «characteristic
function», i.e.  a function that returns ‘True’ if the parameter is part
of the set.  For mappings, it provides the mapping function: given the
key, it returns the associated value.  Below is a list of all functions
available in the module.

 -- Funzione: stringprep.in_table_a1 (code)

     Determine whether 'code' is in tableA.1 (Unassigned code points in
     Unicode 3.2).

 -- Funzione: stringprep.in_table_b1 (code)

     Determine whether 'code' is in tableB.1 (Commonly mapped to
     nothing).

 -- Funzione: stringprep.map_table_b2 (code)

     Return the mapped value for 'code' according to tableB.2 (Mapping
     for case-folding used with NFKC).

 -- Funzione: stringprep.map_table_b3 (code)

     Return the mapped value for 'code' according to tableB.3 (Mapping
     for case-folding used with no normalization).

 -- Funzione: stringprep.in_table_c11 (code)

     Determine whether 'code' is in tableC.1.1 (ASCII space characters).

 -- Funzione: stringprep.in_table_c12 (code)

     Determine whether 'code' is in tableC.1.2 (Non-ASCII space
     characters).

 -- Funzione: stringprep.in_table_c11_c12 (code)

     Determine whether 'code' is in tableC.1 (Space characters, union of
     C.1.1 and C.1.2).

 -- Funzione: stringprep.in_table_c21 (code)

     Determine whether 'code' is in tableC.2.1 (ASCII control
     characters).

 -- Funzione: stringprep.in_table_c22 (code)

     Determine whether 'code' is in tableC.2.2 (Non-ASCII control
     characters).

 -- Funzione: stringprep.in_table_c21_c22 (code)

     Determine whether 'code' is in tableC.2 (Control characters, union
     of C.2.1 and C.2.2).

 -- Funzione: stringprep.in_table_c3 (code)

     Determine whether 'code' is in tableC.3 (Private use).

 -- Funzione: stringprep.in_table_c4 (code)

     Determine whether 'code' is in tableC.4 (Non-character code
     points).

 -- Funzione: stringprep.in_table_c5 (code)

     Determine whether 'code' is in tableC.5 (Surrogate codes).

 -- Funzione: stringprep.in_table_c6 (code)

     Determine whether 'code' is in tableC.6 (Inappropriate for plain
     text).

 -- Funzione: stringprep.in_table_c7 (code)

     Determine whether 'code' is in tableC.7 (Inappropriate for
     canonical representation).

 -- Funzione: stringprep.in_table_c8 (code)

     Determine whether 'code' is in tableC.8 (Change display properties
     or are deprecated).

 -- Funzione: stringprep.in_table_c9 (code)

     Determine whether 'code' is in tableC.9 (Tagging characters).

 -- Funzione: stringprep.in_table_d1 (code)

     Determine whether 'code' is in tableD.1 (Characters with
     bidirectional property «R» or «AL»).

 -- Funzione: stringprep.in_table_d2 (code)

     Determine whether 'code' is in tableD.2 (Characters with
     bidirectional property «L»).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/stringprep.py

   (2) https://datatracker.ietf.org/doc/html/rfc3454.html

   (3) https://datatracker.ietf.org/doc/html/rfc3454.html


File: python.info,  Node: readline — GNU readline interface,  Next: rlcompleter — Completion function for GNU readline,  Prev: stringprep — Internet String Preparation,  Up: Text Processing Services

5.6.8 ‘readline’ — GNU readline interface
-----------------------------------------

__________________________________________________________________

The *note readline: bf. module defines a number of functions to
facilitate completion and reading/writing of history files from the
Python interpreter.  This module can be used directly, or via the *note
rlcompleter: c2. module, which supports completion of Python identifiers
at the interactive prompt.  Settings made using this module affect the
behaviour of both the interpreter’s interactive prompt and the prompts
offered by the built-in *note input(): 14e0. function.

Readline keybindings may be configured via an initialization file,
typically ‘.inputrc’ in your home directory.  See Readline Init File(1)
in the GNU Readline manual for information about the format and
allowable constructs of that file, and the capabilities of the Readline
library in general.

*note Availability: 2128.: not Android, not iOS, not WASI.

This module is not supported on *note mobile platforms: 2245. or *note
WebAssembly platforms: 1b52.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

     Nota: The underlying Readline library API may be implemented by the
     ‘editline’ (‘libedit’) library instead of GNU readline.  On macOS
     the *note readline: bf. module detects which library is being used
     at run time.

     The configuration file for ‘editline’ is different from that of GNU
     readline.  If you programmatically load configuration strings you
     can use *note backend: 1a0f. to determine which library is being
     used.

     If you use ‘editline’/‘libedit’ readline emulation on macOS, the
     initialization file located in your home directory is named
     ‘.editrc’.  For example, the following content in ‘~/.editrc’ will
     turn ON 'vi' keybindings and TAB completion:

          python:bind -v
          python:bind ^I rl_complete

     Also note that different libraries may use different history file
     formats.  When switching the underlying library, existing history
     files may become unusable.

 -- Dati: readline.backend

     The name of the underlying Readline library being used, either
     ‘"readline"’ or ‘"editline"’.

     Added in version 3.13.

* Menu:

* Init file::
* Line buffer::
* History file::
* History list::
* Startup hooks::
* Completion::
* Example::

   ---------- Footnotes ----------

   (1) 
https://tiswww.cwru.edu/php/chet/readline/rluserman.html#Readline-Init-File


File: python.info,  Node: Init file,  Next: Line buffer,  Up: readline — GNU readline interface

5.6.8.1 Init file
.................

The following functions relate to the init file and user configuration:

 -- Funzione: readline.parse_and_bind (string)

     Execute the init line provided in the 'string' argument.  This
     calls ‘rl_parse_and_bind()’ in the underlying library.

 -- Funzione: readline.read_init_file ([filename])

     Execute a readline initialization file.  The default filename is
     the last filename used.  This calls ‘rl_read_init_file()’ in the
     underlying library.  It raises an *note auditing event: 1c56.
     ‘open’ with the file name if given, and ‘"<readline_init_file>"’
     otherwise, regardless of which file the library resolves.

     Cambiato nella versione 3.14: The auditing event was added.


File: python.info,  Node: Line buffer,  Next: History file,  Prev: Init file,  Up: readline — GNU readline interface

5.6.8.2 Line buffer
...................

The following functions operate on the line buffer:

 -- Funzione: readline.get_line_buffer ()

     Return the current contents of the line buffer (‘rl_line_buffer’ in
     the underlying library).

 -- Funzione: readline.insert_text (string)

     Insert text into the line buffer at the cursor position.  This
     calls ‘rl_insert_text()’ in the underlying library, but ignores the
     return value.

 -- Funzione: readline.redisplay ()

     Change what’s displayed on the screen to reflect the current
     contents of the line buffer.  This calls ‘rl_redisplay()’ in the
     underlying library.


File: python.info,  Node: History file,  Next: History list,  Prev: Line buffer,  Up: readline — GNU readline interface

5.6.8.3 History file
....................

The following functions operate on a history file:

 -- Funzione: readline.read_history_file ([filename])

     Load a readline history file, and append it to the history list.
     The default filename is ‘~/.history’.  This calls ‘read_history()’
     in the underlying library and raises an *note auditing event: 1c56.
     ‘open’ with the file name if given and ‘"~/.history"’ otherwise.

     Cambiato nella versione 3.14: The auditing event was added.

 -- Funzione: readline.write_history_file ([filename])

     Save the history list to a readline history file, overwriting any
     existing file.  The default filename is ‘~/.history’.  This calls
     ‘write_history()’ in the underlying library and raises an *note
     auditing event: 1c56. ‘open’ with the file name if given and
     ‘"~/.history"’ otherwise.

     Cambiato nella versione 3.14: The auditing event was added.

 -- Funzione: readline.append_history_file (nelements[, filename])

     Append the last 'nelements' items of history to a file.  The
     default filename is ‘~/.history’.  The file must already exist.
     This calls ‘append_history()’ in the underlying library.  This
     function only exists if Python was compiled for a version of the
     library that supports it.  It raises an *note auditing event: 1c56.
     ‘open’ with the file name if given and ‘"~/.history"’ otherwise.

     Added in version 3.5.

     Cambiato nella versione 3.14: The auditing event was added.

 -- Funzione: readline.get_history_length ()
 -- Funzione: readline.set_history_length (length)

     Set or return the desired number of lines to save in the history
     file.  The *note write_history_file(): 17c4. function uses this
     value to truncate the history file, by calling
     ‘history_truncate_file()’ in the underlying library.  Negative
     values imply unlimited history file size.


File: python.info,  Node: History list,  Next: Startup hooks,  Prev: History file,  Up: readline — GNU readline interface

5.6.8.4 History list
....................

The following functions operate on a global history list:

 -- Funzione: readline.clear_history ()

     Clear the current history.  This calls ‘clear_history()’ in the
     underlying library.  The Python function only exists if Python was
     compiled for a version of the library that supports it.

 -- Funzione: readline.get_current_history_length ()

     Return the number of items currently in the history.  (This is
     different from *note get_history_length(): 27d8, which returns the
     maximum number of lines that will be written to a history file.)

 -- Funzione: readline.get_history_item (index)

     Return the current contents of history item at 'index'.  The item
     index is one-based.  This calls ‘history_get()’ in the underlying
     library.

 -- Funzione: readline.remove_history_item (pos)

     Remove history item specified by its position from the history.
     The position is zero-based.  This calls ‘remove_history()’ in the
     underlying library.

 -- Funzione: readline.replace_history_item (pos, line)

     Replace history item specified by its position with 'line'.  The
     position is zero-based.  This calls ‘replace_history_entry()’ in
     the underlying library.

 -- Funzione: readline.add_history (line)

     Append 'line' to the history buffer, as if it was the last line
     typed.  This calls ‘add_history()’ in the underlying library.

 -- Funzione: readline.set_auto_history (enabled)

     Enable or disable automatic calls to ‘add_history()’ when reading
     input via readline.  The 'enabled' argument should be a Boolean
     value that when true, enables auto history, and that when false,
     disables auto history.

     Added in version 3.6.

     'Dettaglio dell’implementazione di CPython:' Auto history is
     enabled by default, and changes to this do not persist across
     multiple sessions.


File: python.info,  Node: Startup hooks,  Next: Completion,  Prev: History list,  Up: readline — GNU readline interface

5.6.8.5 Startup hooks
.....................

 -- Funzione: readline.set_startup_hook ([function])

     Set or remove the function invoked by the ‘rl_startup_hook’
     callback of the underlying library.  If 'function' is specified, it
     will be used as the new hook function; if omitted or ‘None’, any
     function already installed is removed.  The hook is called with no
     arguments just before readline prints the first prompt.

 -- Funzione: readline.set_pre_input_hook ([function])

     Set or remove the function invoked by the ‘rl_pre_input_hook’
     callback of the underlying library.  If 'function' is specified, it
     will be used as the new hook function; if omitted or ‘None’, any
     function already installed is removed.  The hook is called with no
     arguments after the first prompt has been printed and just before
     readline starts reading input characters.  This function only
     exists if Python was compiled for a version of the library that
     supports it.


File: python.info,  Node: Completion,  Next: Example,  Prev: Startup hooks,  Up: readline — GNU readline interface

5.6.8.6 Completion
..................

The following functions relate to implementing a custom word completion
function.  This is typically operated by the Tab key, and can suggest
and automatically complete a word being typed.  By default, Readline is
set up to be used by *note rlcompleter: c2. to complete Python
identifiers for the interactive interpreter.  If the *note readline: bf.
module is to be used with a custom completer, a different set of word
delimiters should be set.

 -- Funzione: readline.set_completer ([function])

     Set or remove the completer function.  If 'function' is specified,
     it will be used as the new completer function; if omitted or
     ‘None’, any completer function already installed is removed.  The
     completer function is called as ‘function(text, state)’, for
     'state' in ‘0’, ‘1’, ‘2’, …, until it returns a non-string value.
     It should return the next possible completion starting with 'text'.

     The installed completer function is invoked by the 'entry_func'
     callback passed to ‘rl_completion_matches()’ in the underlying
     library.  The 'text' string comes from the first parameter to the
     ‘rl_attempted_completion_function’ callback of the underlying
     library.

 -- Funzione: readline.get_completer ()

     Get the completer function, or ‘None’ if no completer function has
     been set.

 -- Funzione: readline.get_completion_type ()

     Get the type of completion being attempted.  This returns the
     ‘rl_completion_type’ variable in the underlying library as an
     integer.

 -- Funzione: readline.get_begidx ()
 -- Funzione: readline.get_endidx ()

     Get the beginning or ending index of the completion scope.  These
     indexes are the 'start' and 'end' arguments passed to the
     ‘rl_attempted_completion_function’ callback of the underlying
     library.  The values may be different in the same input editing
     scenario based on the underlying C readline implementation.  Ex:
     libedit is known to behave differently than libreadline.

 -- Funzione: readline.set_completer_delims (string)
 -- Funzione: readline.get_completer_delims ()

     Set or get the word delimiters for completion.  These determine the
     start of the word to be considered for completion (the completion
     scope).  These functions access the
     ‘rl_completer_word_break_characters’ variable in the underlying
     library.

 -- Funzione: readline.set_completion_display_matches_hook ([function])

     Set or remove the completion display function.  If 'function' is
     specified, it will be used as the new completion display function;
     if omitted or ‘None’, any completion display function already
     installed is removed.  This sets or clears the
     ‘rl_completion_display_matches_hook’ callback in the underlying
     library.  The completion display function is called as
     ‘function(substitution, [matches], longest_match_length)’ once each
     time matches need to be displayed.


File: python.info,  Node: Example,  Prev: Completion,  Up: readline — GNU readline interface

5.6.8.7 Example
...............

The following example demonstrates how to use the *note readline: bf.
module’s history reading and writing functions to automatically load and
save a history file named ‘.python_history’ from the user’s home
directory.  The code below would normally be executed automatically
during interactive sessions from the user’s *note PYTHONSTARTUP: 1b8.
file.

     import atexit
     import os
     import readline

     histfile = os.path.join(os.path.expanduser("~"), ".python_history")
     try:
         readline.read_history_file(histfile)
         # default history len is -1 (infinite), which may grow unruly
         readline.set_history_length(1000)
     except FileNotFoundError:
         pass

     atexit.register(readline.write_history_file, histfile)

This code is actually automatically run when Python is run in *note
interactive mode: 443. (see *note Readline configuration: 11cb.).

The following example achieves the same goal but supports concurrent
interactive sessions, by only appending the new history.

     import atexit
     import os
     import readline
     histfile = os.path.join(os.path.expanduser("~"), ".python_history")

     try:
         readline.read_history_file(histfile)
         h_len = readline.get_current_history_length()
     except FileNotFoundError:
         open(histfile, 'wb').close()
         h_len = 0

     def save(prev_h_len, histfile):
         new_h_len = readline.get_current_history_length()
         readline.set_history_length(1000)
         readline.append_history_file(new_h_len - prev_h_len, histfile)
     atexit.register(save, h_len, histfile)

The following example extends the *note code.InteractiveConsole: 27ea.
class to support history save/restore.

     import atexit
     import code
     import os
     import readline

     class HistoryConsole(code.InteractiveConsole):
         def __init__(self, locals=None, filename="<console>",
                      histfile=os.path.expanduser("~/.console-history")):
             code.InteractiveConsole.__init__(self, locals, filename)
             self.init_history(histfile)

         def init_history(self, histfile):
             readline.parse_and_bind("tab: complete")
             if hasattr(readline, "read_history_file"):
                 try:
                     readline.read_history_file(histfile)
                 except FileNotFoundError:
                     pass
                 atexit.register(self.save_history, histfile)

         def save_history(self, histfile):
             readline.set_history_length(1000)
             readline.write_history_file(histfile)

     Nota: The new *note REPL: 492. introduced in version 3.13 doesn’t
     support readline.  However, readline can still be used by setting
     the *note PYTHON_BASIC_REPL: 1b6. environment variable.


File: python.info,  Node: rlcompleter — Completion function for GNU readline,  Prev: readline — GNU readline interface,  Up: Text Processing Services

5.6.9 ‘rlcompleter’ — Completion function for GNU readline
----------------------------------------------------------

'Source code:' Lib/rlcompleter.py(1)

__________________________________________________________________

The ‘rlcompleter’ module defines a completion function suitable to be
passed to *note set_completer(): 27e3. in the *note readline: bf.
module.

When this module is imported on a Unix platform with the *note readline:
bf. module available, an instance of the *note Completer: 1d13. class is
automatically created and its *note complete(): 27ee. method is set as
the *note readline completer: 27e2.  The method provides completion of
valid Python *note identifiers and keywords: 2289.

Example:

     >>> import rlcompleter
     >>> import readline
     >>> readline.parse_and_bind("tab: complete")
     >>> readline. <TAB PRESSED>
     readline.__doc__          readline.get_line_buffer(  readline.read_init_file(
     readline.__file__         readline.insert_text(      readline.set_completer(
     readline.__name__         readline.parse_and_bind(
     >>> readline.

The ‘rlcompleter’ module is designed for use with Python’s *note
interactive mode: 443.  Unless Python is run with the *note -S: 13b0.
option, the module is automatically imported and configured (see *note
Readline configuration: 11cb.).

On platforms without *note readline: bf, the *note Completer: 1d13.
class defined by this module can still be used for custom purposes.

 -- Classe: rlcompleter.Completer

     Completer objects have the following method:

      -- Metodo: complete (text, state)

          Return the next possible completion for 'text'.

          When called by the *note readline: bf. module, this method is
          called successively with ‘state == 0, 1, 2, ...’ until the
          method returns ‘None’.

          If called for 'text' that doesn’t include a period character
          (‘'.'’), it will complete from names currently defined in
          *note __main__: 1, *note builtins: 13. and keywords (as
          defined by the *note keyword: 88. module).

          If called for a dotted name, it will try to evaluate anything
          without obvious side-effects (functions will not be evaluated,
          but it can generate calls to *note __getattr__(): 6fb.) up to
          the last part, and find matches for the rest via the *note
          dir(): 845. function.  Any exception raised during the
          evaluation of the expression is caught, silenced and *note
          None: 886. is returned.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/rlcompleter.py


File: python.info,  Node: Binary Data Services,  Next: Data Types,  Prev: Text Processing Services,  Up: The Python Standard Library

5.7 Binary Data Services
========================

The modules described in this chapter provide some basic services
operations for manipulation of binary data.  Other operations on binary
data, specifically in relation to file formats and network protocols,
are described in the relevant sections.

Some libraries described under *note Text Processing Services: 262e.
also work with either ASCII-compatible binary formats (for example,
*note re: be.) or all binary data (for example, *note difflib: 3b.).

In addition, see the documentation for Python’s built-in binary data
types in *note Tipi di sequenze binarie — bytes, bytearray, memoryview:
25a0.

* Menu:

* struct — Interpret bytes as packed binary data::
* codecs — Codec registry and base classes::


File: python.info,  Node: struct — Interpret bytes as packed binary data,  Next: codecs — Codec registry and base classes,  Up: Binary Data Services

5.7.1 ‘struct’ — Interpret bytes as packed binary data
------------------------------------------------------

'Source code:' Lib/struct.py(1)

__________________________________________________________________

This module converts between Python values and C structs represented as
Python *note bytes: 192. objects.  Compact *note format strings: 27f5.
describe the intended conversions to/from Python values.  The module’s
functions and objects can be used for two largely distinct applications,
data exchange with external sources (files or network connections), or
data transfer between the Python application and the C layer.

     Nota: When no prefix character is given, native mode is the
     default.  It packs or unpacks data based on the platform and
     compiler on which the Python interpreter was built.  The result of
     packing a given C struct includes pad bytes which maintain proper
     alignment for the C types involved; similarly, alignment is taken
     into account when unpacking.  In contrast, when communicating data
     between external sources, the programmer is responsible for
     defining byte ordering and padding between elements.  See *note
     Byte Order, Size, and Alignment: 27f6. for details.

Several *note struct: db. functions (and methods of *note Struct: 175f.)
take a 'buffer' argument.  This refers to objects that implement the
*note Buffer Protocol: 260. and provide either a readable or
read-writable buffer.  The most common types used for that purpose are
*note bytes: 192. and *note bytearray: 344, but many other types that
can be viewed as an array of bytes implement the buffer protocol, so
that they can be read/filled without additional copying from a *note
bytes: 192. object.

* Menu:

* Functions and Exceptions::
* Format Strings::
* Applications::
* Classes: Classes<2>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/struct.py


File: python.info,  Node: Functions and Exceptions,  Next: Format Strings,  Up: struct — Interpret bytes as packed binary data

5.7.1.1 Functions and Exceptions
................................

The module defines the following exception and functions:

 -- Eccezione: struct.error

     Exception raised on various occasions; argument is a string
     describing what is wrong.

 -- Funzione: struct.pack (format, v1, v2, ...)

     Return a bytes object containing the values 'v1', 'v2', … packed
     according to the format string 'format'.  The arguments must match
     the values required by the format exactly.

 -- Funzione: struct.pack_into (format, buffer, offset, v1, v2, ...)

     Pack the values 'v1', 'v2', … according to the format string
     'format' and write the packed bytes into the writable buffer
     'buffer' starting at position 'offset'.  Note that 'offset' is a
     required argument.

 -- Funzione: struct.unpack (format, buffer)

     Unpack from the buffer 'buffer' (presumably packed by ‘pack(format,
     ...)’) according to the format string 'format'.  The result is a
     tuple even if it contains exactly one item.  The buffer’s size in
     bytes must match the size required by the format, as reflected by
     *note calcsize(): 1d91.

 -- Funzione: struct.unpack_from (format, /, buffer, offset=0)

     Unpack from 'buffer' starting at position 'offset', according to
     the format string 'format'.  The result is a tuple even if it
     contains exactly one item.  The buffer’s size in bytes, starting at
     position 'offset', must be at least the size required by the
     format, as reflected by *note calcsize(): 1d91.

 -- Funzione: struct.iter_unpack (format, buffer)

     Iteratively unpack from the buffer 'buffer' according to the format
     string 'format'.  This function returns an iterator which will read
     equally sized chunks from the buffer until all its contents have
     been consumed.  The buffer’s size in bytes must be a multiple of
     the size required by the format, as reflected by *note calcsize():
     1d91.

     Each iteration yields a tuple as specified by the format string.

     Added in version 3.4.

 -- Funzione: struct.calcsize (format)

     Return the size of the struct (and hence of the bytes object
     produced by ‘pack(format, ...)’) corresponding to the format string
     'format'.


File: python.info,  Node: Format Strings,  Next: Applications,  Prev: Functions and Exceptions,  Up: struct — Interpret bytes as packed binary data

5.7.1.2 Format Strings
......................

Format strings describe the data layout when packing and unpacking data.
They are built up from *note format characters: 27fb, which specify the
type of data being packed/unpacked.  In addition, special characters
control the *note byte order, size and alignment: 27f6.  Each format
string consists of an optional prefix character which describes the
overall properties of the data and one or more format characters which
describe the actual data values and padding.

* Menu:

* Byte Order, Size, and Alignment: Byte Order Size and Alignment.
* Format Characters::
* Examples: Examples<2>.


File: python.info,  Node: Byte Order Size and Alignment,  Next: Format Characters,  Up: Format Strings

5.7.1.3 Byte Order, Size, and Alignment
.......................................

By default, C types are represented in the machine’s native format and
byte order, and properly aligned by skipping pad bytes if necessary
(according to the rules used by the C compiler).  This behavior is
chosen so that the bytes of a packed struct correspond exactly to the
memory layout of the corresponding C struct.  Whether to use native byte
ordering and padding or standard formats depends on the application.

Alternatively, the first character of the format string can be used to
indicate the byte order, size and alignment of the packed data,
according to the following table:

Character       Byte order                   Size           Alignment
                                                            
----------------------------------------------------------------------------
                                                            
‘@’             native                       native         native
                                                            
                                                            
‘=’             native                       standard       none
                                                            
                                                            
‘<’             little-endian                standard       none
                                                            
                                                            
‘>’             big-endian                   standard       none
                                                            
                                                            
‘!’             network (= big-endian)       standard       none
                                                            

If the first character is not one of these, ‘'@'’ is assumed.

     Nota: The number 1023 (‘0x3ff’ in hexadecimal) has the following
     byte representations:

        * ‘03 ff’ in big-endian (‘>’)

        * ‘ff 03’ in little-endian (‘<’)

     Python example:

          >>> import struct
          >>> struct.pack('>h', 1023)
          b'\x03\xff'
          >>> struct.pack('<h', 1023)
          b'\xff\x03'

Native byte order is big-endian or little-endian, depending on the host
system.  For example, Intel x86, AMD64 (x86-64), and Apple M1 are
little-endian; IBM z and many legacy architectures are big-endian.  Use
*note sys.byteorder: 25d6. to check the endianness of your system.

Native size and alignment are determined using the C compiler’s ‘sizeof’
expression.  This is always combined with native byte order.

Standard size depends only on the format character; see the table in the
*note Format Characters: 27fb. section.

Note the difference between ‘'@'’ and ‘'='’: both use native byte order,
but the size and alignment of the latter is standardized.

The form ‘'!'’ represents the network byte order which is always
big-endian as defined in IETF RFC 1700(1).

There is no way to indicate non-native byte order (force byte-swapping);
use the appropriate choice of ‘'<'’ or ‘'>'’.

Notes:

  1. Padding is only automatically added between successive structure
     members.  No padding is added at the beginning or the end of the
     encoded struct.

  2. No padding is added when using non-native size and alignment, e.g.
     with “<”, “>”, “=”, and “!”.

  3. To align the end of a structure to the alignment requirement of a
     particular type, end the format with the code for that type with a
     repeat count of zero.  See *note Examples: 27fd.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc1700


File: python.info,  Node: Format Characters,  Next: Examples<2>,  Prev: Byte Order Size and Alignment,  Up: Format Strings

5.7.1.4 Format Characters
.........................

Format characters have the following meaning; the conversion between C
and Python values should be obvious given their types.  The “Standard
size” column refers to the size of the packed value in bytes when using
standard size; that is, when the format string starts with one of ‘'<'’,
‘'>'’, ‘'!'’ or ‘'='’.  When using native size, the size of the packed
value is platform-dependent.

Format       C Type                         Python type              Standard size        Notes
                                                                                          
-----------------------------------------------------------------------------------------------------------
                                                                                          
‘x’          pad byte                       no value                                      (7)
                                                                                          
                                                                                          
‘c’          char                           bytes of length 1        1
                                                                     
                                                                                          
‘b’          signed char                    integer                  1                    (1), (2)
                                                                                          
                                                                                          
‘B’          unsigned char                  integer                  1                    (2)
                                                                                          
                                                                                          
‘?’          _Bool                          bool                     1                    (1)
                                                                                          
                                                                                          
‘h’          short                          integer                  2                    (2)
                                                                                          
                                                                                          
‘H’          unsigned short                 integer                  2                    (2)
                                                                                          
                                                                                          
‘i’          int                            integer                  4                    (2)
                                                                                          
                                                                                          
‘I’          unsigned int                   integer                  4                    (2)
                                                                                          
                                                                                          
‘l’          long                           integer                  4                    (2)
                                                                                          
                                                                                          
‘L’          unsigned long                  integer                  4                    (2)
                                                                                          
                                                                                          
‘q’          long long                      integer                  8                    (2)
                                                                                          
                                                                                          
‘Q’          unsigned long long             integer                  8                    (2)
                                                                                          
                                                                                          
‘n’          ‘ssize_t’                      integer                                       (3)
                                                                                          
                                                                                          
‘N’          ‘size_t’                       integer                                       (3)
                                                                                          
                                                                                          
‘e’          (6)                            float                    2                    (4)
                                                                                          
                                                                                          
‘f’          float                          float                    4                    (4)
                                                                                          
                                                                                          
‘d’          double                         float                    8                    (4)
                                                                                          
                                                                                          
‘F’          float complex                  complex                  8                    (10)
                                                                                          
                                                                                          
‘D’          double complex                 complex                  16                   (10)
                                                                                          
                                                                                          
‘s’          char[]                         bytes                                         (9)
                                                                                          
                                                                                          
‘p’          char[]                         bytes                                         (8)
                                                                                          
                                                                                          
‘P’          void*                          integer                                       (5)
                                                                                          

Cambiato nella versione 3.3: Added support for the ‘'n'’ and ‘'N'’
formats.

Cambiato nella versione 3.6: Added support for the ‘'e'’ format.

Cambiato nella versione 3.14: Added support for the ‘'F'’ and ‘'D'’
formats.

Notes:

  1. 
     The ‘'?'’ conversion code corresponds to the _Bool type defined by
     C standards since C99.  In standard mode, it is represented by one
     byte.

  2. When attempting to pack a non-integer using any of the integer
     conversion codes, if the non-integer has a *note __index__(): 19e.
     method then that method is called to convert the argument to an
     integer before packing.

     Cambiato nella versione 3.2: Added use of the *note __index__():
     19e. method for non-integers.

  3. The ‘'n'’ and ‘'N'’ conversion codes are only available for the
     native size (selected as the default or with the ‘'@'’ byte order
     character).  For the standard size, you can use whichever of the
     other integer formats fits your application.

  4. For the ‘'f'’, ‘'d'’ and ‘'e'’ conversion codes, the packed
     representation uses the IEEE 754 binary32, binary64 or binary16
     format (for ‘'f'’, ‘'d'’ or ‘'e'’ respectively), regardless of the
     floating-point format used by the platform.

  5. The ‘'P'’ format character is only available for the native byte
     ordering (selected as the default or with the ‘'@'’ byte order
     character).  The byte order character ‘'='’ chooses to use little-
     or big-endian ordering based on the host system.  The struct module
     does not interpret this as native ordering, so the ‘'P'’ format is
     not available.

  6. The IEEE 754 binary16 «half precision» type was introduced in the
     2008 revision of the IEEE 754 standard(1).  It has a sign bit, a
     5-bit exponent and 11-bit precision (with 10 bits explicitly
     stored), and can represent numbers between approximately ‘6.1e-05’
     and ‘6.5e+04’ at full precision.  This type is not widely supported
     by C compilers: on a typical machine, an unsigned short can be used
     for storage, but not for math operations.  See the Wikipedia page
     on the half-precision floating-point format(2) for more
     information.

  7. When packing, ‘'x'’ inserts one NUL byte.

  8. The ‘'p'’ format character encodes a «Pascal string», meaning a
     short variable-length string stored in a 'fixed number of bytes',
     given by the count.  The first byte stored is the length of the
     string, or 255, whichever is smaller.  The bytes of the string
     follow.  If the string passed in to *note pack(): 147e. is too long
     (longer than the count minus 1), only the leading ‘count-1’ bytes
     of the string are stored.  If the string is shorter than ‘count-1’,
     it is padded with null bytes so that exactly count bytes in all are
     used.  Note that for *note unpack(): 1842, the ‘'p'’ format
     character consumes ‘count’ bytes, but that the string returned can
     never contain more than 255 bytes.

  9. For the ‘'s'’ format character, the count is interpreted as the
     length of the bytes, not a repeat count like for the other format
     characters; for example, ‘'10s'’ means a single 10-byte string
     mapping to or from a single Python byte string, while ‘'10c'’ means
     10 separate one byte character elements (e.g., ‘cccccccccc’)
     mapping to or from ten different Python byte objects.  (See *note
     Examples: 27fd. for a concrete demonstration of the difference.)
     If a count is not given, it defaults to 1.  For packing, the string
     is truncated or padded with null bytes as appropriate to make it
     fit.  For unpacking, the resulting bytes object always has exactly
     the specified number of bytes.  As a special case, ‘'0s'’ means a
     single, empty string (while ‘'0c'’ means 0 characters).

  10. For the ‘'F'’ and ‘'D'’ format characters, the packed
     representation uses the IEEE 754 binary32 and binary64 format for
     components of the complex number, regardless of the floating-point
     format used by the platform.  Note that complex types (‘F’ and ‘D’)
     are available unconditionally, despite complex types being an
     optional feature in C. As specified in the C11 standard, each
     complex type is represented by a two-element C array containing,
     respectively, the real and imaginary parts.

A format character may be preceded by an integral repeat count.  For
example, the format string ‘'4h'’ means exactly the same as ‘'hhhh'’.

Whitespace characters between formats are ignored; a count and its
format must not contain whitespace though.

When packing a value ‘x’ using one of the integer formats (‘'b'’, ‘'B'’,
‘'h'’, ‘'H'’, ‘'i'’, ‘'I'’, ‘'l'’, ‘'L'’, ‘'q'’, ‘'Q'’), if ‘x’ is
outside the valid range for that format then *note struct.error: 152b.
is raised.

Cambiato nella versione 3.1: Previously, some of the integer formats
wrapped out-of-range values and raised *note DeprecationWarning: 1a3.
instead of *note struct.error: 152b.

For the ‘'?'’ format character, the return value is either *note True:
e09. or *note False: d2d.  When packing, the truth value of the argument
object is used.  Either 0 or 1 in the native or standard bool
representation will be packed, and any non-zero value will be ‘True’
when unpacking.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/IEEE_754-2008_revision

   (2) 
https://en.wikipedia.org/wiki/Half-precision_floating-point_format


File: python.info,  Node: Examples<2>,  Prev: Format Characters,  Up: Format Strings

5.7.1.5 Examples
................

     Nota: Native byte order examples (designated by the ‘'@'’ format
     prefix or lack of any prefix character) may not match what the
     reader’s machine produces as that depends on the platform and
     compiler.

Pack and unpack integers of three different sizes, using big endian
ordering:

     >>> from struct import *
     >>> pack(">bhl", 1, 2, 3)
     b'\x01\x00\x02\x00\x00\x00\x03'
     >>> unpack('>bhl', b'\x01\x00\x02\x00\x00\x00\x03')
     (1, 2, 3)
     >>> calcsize('>bhl')
     7

Attempt to pack an integer which is too large for the defined field:

     >>> pack(">h", 99999)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     struct.error: 'h' format requires -32768 <= number <= 32767

Demonstrate the difference between ‘'s'’ and ‘'c'’ format characters:

     >>> pack("@ccc", b'1', b'2', b'3')
     b'123'
     >>> pack("@3s", b'123')
     b'123'

Unpacked fields can be named by assigning them to variables or by
wrapping the result in a named tuple:

     >>> record = b'raymond   \x32\x12\x08\x01\x08'
     >>> name, serialnum, school, gradelevel = unpack('<10sHHb', record)

     >>> from collections import namedtuple
     >>> Student = namedtuple('Student', 'name serialnum school gradelevel')
     >>> Student._make(unpack('<10sHHb', record))
     Student(name=b'raymond   ', serialnum=4658, school=264, gradelevel=8)

The ordering of format characters may have an impact on size in native
mode since padding is implicit.  In standard mode, the user is
responsible for inserting any desired padding.  Note in the first ‘pack’
call below that three NUL bytes were added after the packed ‘'#'’ to
align the following integer on a four-byte boundary.  In this example,
the output was produced on a little endian machine:

     >>> pack('@ci', b'#', 0x12131415)
     b'#\x00\x00\x00\x15\x14\x13\x12'
     >>> pack('@ic', 0x12131415, b'#')
     b'\x15\x14\x13\x12#'
     >>> calcsize('@ci')
     8
     >>> calcsize('@ic')
     5

The following format ‘'llh0l'’ results in two pad bytes being added at
the end, assuming the platform’s longs are aligned on 4-byte boundaries:

     >>> pack('@llh0l', 1, 2, 3)
     b'\x00\x00\x00\x01\x00\x00\x00\x02\x00\x03\x00\x00'

Vedi anche
..........

Module *note array: 8.

     Packed binary storage of homogeneous data.

Module *note json: 86.

     JSON encoder and decoder.

Module *note pickle: ab.

     Python object serialization.


File: python.info,  Node: Applications,  Next: Classes<2>,  Prev: Format Strings,  Up: struct — Interpret bytes as packed binary data

5.7.1.6 Applications
....................

Two main applications for the *note struct: db. module exist, data
interchange between Python and C code within an application or another
application compiled using the same compiler (*note native formats:
2802.), and data interchange between applications using agreed upon data
layout (*note standard formats: 2803.).  Generally speaking, the format
strings constructed for these two domains are distinct.

* Menu:

* Native Formats::
* Standard Formats::


File: python.info,  Node: Native Formats,  Next: Standard Formats,  Up: Applications

5.7.1.7 Native Formats
......................

When constructing format strings which mimic native layouts, the
compiler and machine architecture determine byte ordering and padding.
In such cases, the ‘@’ format character should be used to specify native
byte ordering and data sizes.  Internal pad bytes are normally inserted
automatically.  It is possible that a zero-repeat format code will be
needed at the end of a format string to round up to the correct byte
boundary for proper alignment of consecutive chunks of data.

Consider these two simple examples (on a 64-bit, little-endian machine):

     >>> calcsize('@lhl')
     24
     >>> calcsize('@llh')
     18

Data is not padded to an 8-byte boundary at the end of the second format
string without the use of extra padding.  A zero-repeat format code
solves that problem:

     >>> calcsize('@llh0l')
     24

The ‘'x'’ format code can be used to specify the repeat, but for native
formats it is better to use a zero-repeat format like ‘'0l'’.

By default, native byte ordering and alignment is used, but it is better
to be explicit and use the ‘'@'’ prefix character.


File: python.info,  Node: Standard Formats,  Prev: Native Formats,  Up: Applications

5.7.1.8 Standard Formats
........................

When exchanging data beyond your process such as networking or storage,
be precise.  Specify the exact byte order, size, and alignment.  Do not
assume they match the native order of a particular machine.  For
example, network byte order is big-endian, while many popular CPUs are
little-endian.  By defining this explicitly, the user need not care
about the specifics of the platform their code is running on.  The first
character should typically be ‘<’ or ‘>’ (or ‘!’).  Padding is the
responsibility of the programmer.  The zero-repeat format character
won’t work.  Instead, the user must explicitly add ‘'x'’ pad bytes where
needed.  Revisiting the examples from the previous section, we have:

     >>> calcsize('<qh6xq')
     24
     >>> pack('<qh6xq', 1, 2, 3) == pack('@lhl', 1, 2, 3)
     True
     >>> calcsize('@llh')
     18
     >>> pack('@llh', 1, 2, 3) == pack('<qqh', 1, 2, 3)
     True
     >>> calcsize('<qqh6x')
     24
     >>> calcsize('@llh0l')
     24
     >>> pack('@llh0l', 1, 2, 3) == pack('<qqh6x', 1, 2, 3)
     True

The above results (executed on a 64-bit machine) aren’t guaranteed to
match when executed on different machines.  For example, the examples
below were executed on a 32-bit machine:

     >>> calcsize('<qqh6x')
     24
     >>> calcsize('@llh0l')
     12
     >>> pack('@llh0l', 1, 2, 3) == pack('<qqh6x', 1, 2, 3)
     False


File: python.info,  Node: Classes<2>,  Prev: Applications,  Up: struct — Interpret bytes as packed binary data

5.7.1.9 Classes
...............

The *note struct: db. module also defines the following type:

 -- Classe: struct.Struct (format)

     Return a new Struct object which writes and reads binary data
     according to the format string 'format'.  Creating a ‘Struct’
     object once and calling its methods is more efficient than calling
     module-level functions with the same format since the format string
     is only compiled once.

          Nota: The compiled versions of the most recent format strings
          passed to the module-level functions are cached, so programs
          that use only a few format strings needn’t worry about reusing
          a single *note Struct: 175f. instance.

     Compiled Struct objects support the following methods and
     attributes:

      -- Metodo: pack (v1, v2, ...)

          Identical to the *note pack(): 147e. function, using the
          compiled format.  (‘len(result)’ will equal *note size: 2809.)

      -- Metodo: pack_into (buffer, offset, v1, v2, ...)

          Identical to the *note pack_into(): 27f8. function, using the
          compiled format.

      -- Metodo: unpack (buffer)

          Identical to the *note unpack(): 1842. function, using the
          compiled format.  The buffer’s size in bytes must equal *note
          size: 2809.

      -- Metodo: unpack_from (buffer, offset=0)

          Identical to the *note unpack_from(): 27f9. function, using
          the compiled format.  The buffer’s size in bytes, starting at
          position 'offset', must be at least *note size: 2809.

      -- Metodo: iter_unpack (buffer)

          Identical to the *note iter_unpack(): 11c1. function, using
          the compiled format.  The buffer’s size in bytes must be a
          multiple of *note size: 2809.

          Added in version 3.4.

      -- Attributo: format

          The format string used to construct this Struct object.

          Cambiato nella versione 3.7: The format string type is now
          *note str: 169. instead of *note bytes: 192.

      -- Attributo: size

          The calculated size of the struct (and hence of the bytes
          object produced by the *note pack(): 147e. method)
          corresponding to *note format: 199.

     Cambiato nella versione 3.13: The 'repr()' of structs has changed.
     It is now:

          >>> Struct('i')
          Struct('i')


File: python.info,  Node: codecs — Codec registry and base classes,  Prev: struct — Interpret bytes as packed binary data,  Up: Binary Data Services

5.7.2 ‘codecs’ — Codec registry and base classes
------------------------------------------------

'Source code:' Lib/codecs.py(1)

__________________________________________________________________

This module defines base classes for standard Python codecs (encoders
and decoders) and provides access to the internal Python codec registry,
which manages the codec and error handling lookup process.  Most
standard codecs are *note text encodings: 25b7, which encode text to
bytes (and decode bytes to text), but there are also codecs provided
that encode text to text, and bytes to bytes.  Custom codecs may encode
and decode between arbitrary types, but some module features are
restricted to be used specifically with *note text encodings: 25b7. or
with codecs that encode to *note bytes: 192.

The module defines the following functions for encoding and decoding
with any codec:

 -- Funzione: codecs.encode (obj, encoding='utf-8', errors='strict')

     Encodes 'obj' using the codec registered for 'encoding'.

     'Errors' may be given to set the desired error handling scheme.
     The default error handler is ‘'strict'’ meaning that encoding
     errors raise *note ValueError: 2ec. (or a more codec specific
     subclass, such as *note UnicodeEncodeError: 888.).  Refer to *note
     Codec Base Classes: 2810. for more information on codec error
     handling.

 -- Funzione: codecs.decode (obj, encoding='utf-8', errors='strict')

     Decodes 'obj' using the codec registered for 'encoding'.

     'Errors' may be given to set the desired error handling scheme.
     The default error handler is ‘'strict'’ meaning that decoding
     errors raise *note ValueError: 2ec. (or a more codec specific
     subclass, such as *note UnicodeDecodeError: c0a.).  Refer to *note
     Codec Base Classes: 2810. for more information on codec error
     handling.

 -- Funzione: codecs.charmap_build (string)

     Return a mapping suitable for encoding with a custom single-byte
     encoding.  Given a *note str: 169. 'string' of up to 256 characters
     representing a decoding table, returns either a compact internal
     mapping object ‘EncodingMap’ or a *note dictionary: 183. mapping
     character ordinals to byte values.  Raises a *note TypeError: 198.
     on invalid input.

The full details for each codec can also be looked up directly:

 -- Funzione: codecs.lookup (encoding, /)

     Looks up the codec info in the Python codec registry and returns a
     *note CodecInfo: 1a54. object as defined below.

     Encodings are first looked up in the registry’s cache.  If not
     found, the list of registered search functions is scanned.  If no
     *note CodecInfo: 1a54. object is found, a *note LookupError: 2633.
     is raised.  Otherwise, the *note CodecInfo: 1a54. object is stored
     in the cache and returned to the caller.

 -- Classe: codecs.CodecInfo (encode, decode, streamreader=None,
          streamwriter=None, incrementalencoder=None,
          incrementaldecoder=None, name=None)

     Codec details when looking up the codec registry.  The constructor
     arguments are stored in attributes of the same name:

      -- Attributo: name

          The name of the encoding.

      -- Attributo: encode
      -- Attributo: decode

          The stateless encoding and decoding functions.  These must be
          functions or methods which have the same interface as the
          *note encode(): 2815. and *note decode(): 2816. methods of
          Codec instances (see *note Codec Interface: 2817.).  The
          functions or methods are expected to work in a stateless mode.

      -- Attributo: incrementalencoder
      -- Attributo: incrementaldecoder

          Incremental encoder and decoder classes or factory functions.
          These have to provide the interface defined by the base
          classes *note IncrementalEncoder: 281a. and *note
          IncrementalDecoder: 281b, respectively.  Incremental codecs
          can maintain state.

      -- Attributo: streamwriter
      -- Attributo: streamreader

          Stream writer and reader classes or factory functions.  These
          have to provide the interface defined by the base classes
          *note StreamWriter: 281e. and *note StreamReader: 281f,
          respectively.  Stream codecs can maintain state.

To simplify access to the various codec components, the module provides
these additional functions which use *note lookup(): b5e. for the codec
lookup:

 -- Funzione: codecs.getencoder (encoding)

     Look up the codec for the given encoding and return its encoder
     function.

     Raises a *note LookupError: 2633. in case the encoding cannot be
     found.

 -- Funzione: codecs.getdecoder (encoding)

     Look up the codec for the given encoding and return its decoder
     function.

     Raises a *note LookupError: 2633. in case the encoding cannot be
     found.

 -- Funzione: codecs.getincrementalencoder (encoding)

     Look up the codec for the given encoding and return its incremental
     encoder class or factory function.

     Raises a *note LookupError: 2633. in case the encoding cannot be
     found or the codec doesn’t support an incremental encoder.

 -- Funzione: codecs.getincrementaldecoder (encoding)

     Look up the codec for the given encoding and return its incremental
     decoder class or factory function.

     Raises a *note LookupError: 2633. in case the encoding cannot be
     found or the codec doesn’t support an incremental decoder.

 -- Funzione: codecs.getreader (encoding)

     Look up the codec for the given encoding and return its *note
     StreamReader: 281f. class or factory function.

     Raises a *note LookupError: 2633. in case the encoding cannot be
     found.

 -- Funzione: codecs.getwriter (encoding)

     Look up the codec for the given encoding and return its *note
     StreamWriter: 281e. class or factory function.

     Raises a *note LookupError: 2633. in case the encoding cannot be
     found.

Custom codecs are made available by registering a suitable codec search
function:

 -- Funzione: codecs.register (search_function, /)

     Register a codec search function.  Search functions are expected to
     take one argument, being the encoding name in all lower case
     letters with hyphens and spaces converted to underscores, and
     return a *note CodecInfo: 1a54. object.  In case a search function
     cannot find a given encoding, it should return ‘None’.

     Cambiato nella versione 3.9: Hyphens and spaces are converted to
     underscore.

 -- Funzione: codecs.unregister (search_function, /)

     Unregister a codec search function and clear the registry’s cache.
     If the search function is not registered, do nothing.

     Added in version 3.10.

While the builtin *note open(): 316. and the associated *note io: 83.
module are the recommended approach for working with encoded text files,
this module provides additional utility functions and classes that allow
the use of a wider range of codecs when working with binary files:

 -- Funzione: codecs.open (filename, mode='r', encoding=None,
          errors='strict', buffering=-1)

     Open an encoded file using the given 'mode' and return an instance
     of *note StreamReaderWriter: 2827, providing transparent
     encoding/decoding.  The default file mode is ‘'r'’, meaning to open
     the file in read mode.

          Nota: If 'encoding' is not ‘None’, then the underlying encoded
          files are always opened in binary mode.  No automatic
          conversion of ‘'\n'’ is done on reading and writing.  The
          'mode' argument may be any binary mode acceptable to the
          built-in *note open(): 316. function; the ‘'b'’ is
          automatically added.

     'encoding' specifies the encoding which is to be used for the file.
     Any encoding that encodes to and decodes from bytes is allowed, and
     the data types supported by the file methods depend on the codec
     used.

     'errors' may be given to define the error handling.  It defaults to
     ‘'strict'’ which causes a *note ValueError: 2ec. to be raised in
     case an encoding error occurs.

     'buffering' has the same meaning as for the built-in *note open():
     316. function.  It defaults to -1 which means that the default
     buffer size will be used.

     Cambiato nella versione 3.11: The ‘'U'’ mode has been removed.

     Deprecato dalla versione 3.14: *note codecs.open(): 315. has been
     superseded by *note open(): 316.

 -- Funzione: codecs.EncodedFile (file, data_encoding,
          file_encoding=None, errors='strict')

     Return a *note StreamRecoder: 1dbc. instance, a wrapped version of
     'file' which provides transparent transcoding.  The original file
     is closed when the wrapped version is closed.

     Data written to the wrapped file is decoded according to the given
     'data_encoding' and then written to the original file as bytes
     using 'file_encoding'.  Bytes read from the original file are
     decoded according to 'file_encoding', and the result is encoded
     using 'data_encoding'.

     If 'file_encoding' is not given, it defaults to 'data_encoding'.

     'errors' may be given to define the error handling.  It defaults to
     ‘'strict'’, which causes *note ValueError: 2ec. to be raised in
     case an encoding error occurs.

 -- Funzione: codecs.iterencode (iterator, encoding, errors='strict',
          **kwargs)

     Uses an incremental encoder to iteratively encode the input
     provided by 'iterator'.  'iterator' must yield *note str: 169.
     objects.  This function is a *note generator: 1263.  The 'errors'
     argument (as well as any other keyword argument) is passed through
     to the incremental encoder.

     This function requires that the codec accept text *note str: 169.
     objects to encode.  Therefore it does not support bytes-to-bytes
     encoders such as ‘base64_codec’.

 -- Funzione: codecs.iterdecode (iterator, encoding, errors='strict',
          **kwargs)

     Uses an incremental decoder to iteratively decode the input
     provided by 'iterator'.  'iterator' must yield *note bytes: 192.
     objects.  This function is a *note generator: 1263.  The 'errors'
     argument (as well as any other keyword argument) is passed through
     to the incremental decoder.

     This function requires that the codec accept *note bytes: 192.
     objects to decode.  Therefore it does not support text-to-text
     encoders such as ‘rot_13’, although ‘rot_13’ may be used
     equivalently with *note iterencode(): 2829.

 -- Funzione: codecs.readbuffer_encode (buffer, errors=None, /)

     Return a *note tuple: 614. containing the raw bytes of 'buffer', a
     *note buffer-compatible object: 260. or *note str: 169. (encoded to
     UTF-8 before processing), and their length in bytes.

     The 'errors' argument is ignored.

          >>> codecs.readbuffer_encode(b"Zito")
          (b'Zito', 4)

The module also provides the following constants which are useful for
reading and writing to platform dependent files:

 -- Dati: codecs.BOM
 -- Dati: codecs.BOM_BE
 -- Dati: codecs.BOM_LE
 -- Dati: codecs.BOM_UTF8
 -- Dati: codecs.BOM_UTF16
 -- Dati: codecs.BOM_UTF16_BE
 -- Dati: codecs.BOM_UTF16_LE
 -- Dati: codecs.BOM_UTF32
 -- Dati: codecs.BOM_UTF32_BE
 -- Dati: codecs.BOM_UTF32_LE

     These constants define various byte sequences, being Unicode byte
     order marks (BOMs) for several encodings.  They are used in UTF-16
     and UTF-32 data streams to indicate the byte order used, and in
     UTF-8 as a Unicode signature.  *note BOM_UTF16: 2830. is either
     *note BOM_UTF16_BE: 2831. or *note BOM_UTF16_LE: 2832. depending on
     the platform’s native byte order, *note BOM: 282c. is an alias for
     *note BOM_UTF16: 2830, *note BOM_LE: 282e. for *note BOM_UTF16_LE:
     2832. and *note BOM_BE: 282d. for *note BOM_UTF16_BE: 2831.  The
     others represent the BOM in UTF-8 and UTF-32 encodings.

* Menu:

* Codec Base Classes::
* Encodings and Unicode::
* Standard Encodings::
* Python Specific Encodings::
* encodings — Encodings package::
* encodings.idna — Internationalized Domain Names in Applications: encodings idna — Internationalized Domain Names in Applications.
* encodings.mbcs — Windows ANSI codepage: encodings mbcs — Windows ANSI codepage.
* encodings.utf_8_sig — UTF-8 codec with BOM signature: encodings utf_8_sig — UTF-8 codec with BOM signature.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/codecs.py


File: python.info,  Node: Codec Base Classes,  Next: Encodings and Unicode,  Up: codecs — Codec registry and base classes

5.7.2.1 Codec Base Classes
..........................

The *note codecs: 1c. module defines a set of base classes which define
the interfaces for working with codec objects, and can also be used as
the basis for custom codec implementations.

Each codec has to define four interfaces to make it usable as codec in
Python: stateless encoder, stateless decoder, stream reader and stream
writer.  The stream reader and writers typically reuse the stateless
encoder/decoder to implement the file protocols.  Codec authors also
need to define how the codec will handle encoding and decoding errors.
* Menu:

* Error Handlers::
* Stateless Encoding and Decoding::
* Incremental Encoding and Decoding::
* Stream Encoding and Decoding::


File: python.info,  Node: Error Handlers,  Next: Stateless Encoding and Decoding,  Up: Codec Base Classes

5.7.2.2 Error Handlers
......................

To simplify and standardize error handling, codecs may implement
different error handling schemes by accepting the 'errors' string
argument:

     >>> 'German ß, ♬'.encode(encoding='ascii', errors='backslashreplace')
     b'German \\xdf, \\u266c'
     >>> 'German ß, ♬'.encode(encoding='ascii', errors='xmlcharrefreplace')
     b'German &#223;, &#9836;'

The following error handlers can be used with all Python *note Standard
Encodings: fba. codecs:

Value                         Meaning
                              
----------------------------------------------------------------------------------
                              
‘'strict'’                    Raise *note UnicodeError: 462. (or a subclass),
                              this is the default.  Implemented in
                              *note strict_errors(): 2839.
                              
                              
‘'ignore'’                    Ignore the malformed data and continue without
                              further notice.  Implemented in
                              *note ignore_errors(): 283a.
                              
                              
‘'replace'’                   Replace with a replacement marker.  On encoding,
                              use ‘?’ (ASCII character).  On decoding, use ‘�’
                              (U+FFFD, the official REPLACEMENT CHARACTER).
                              Implemented in *note replace_errors(): 18aa.
                              
                              
‘'backslashreplace'’          Replace with backslashed escape sequences.  On
                              encoding, use hexadecimal form of Unicode code
                              point with formats ‘\xHH’ ‘\uXXXX’ ‘\UXXXXXXXX’.
                              On decoding, use hexadecimal form of byte value
                              with format ‘\xHH’.  Implemented in
                              *note backslashreplace_errors(): 18ab.
                              
                              
‘'surrogateescape'’           On decoding, replace byte with individual
                              surrogate code ranging from ‘U+DC80’ to ‘U+DCFF’.
                              This code will then be turned back into the same
                              byte when the ‘'surrogateescape'’ error handler
                              is used when encoding the data.  (See PEP 383(1)
                              for more.)
                              

The following error handlers are only applicable to encoding (within
*note text encodings: 25b7.):

Value                         Meaning
                              
----------------------------------------------------------------------------------
                              
‘'xmlcharrefreplace'’         Replace with XML/HTML numeric character
                              reference, which is a decimal form of Unicode
                              code point with format ‘&#NUM;’.  Implemented in
                              *note xmlcharrefreplace_errors(): 18ac.
                              
                              
‘'namereplace'’               Replace with ‘\N{...}’ escape sequences, what
                              appears in the braces is the Name property from
                              Unicode Character Database.  Implemented in
                              *note namereplace_errors(): 283b.
                              

In addition, the following error handler is specific to the given
codecs:

Value                   Codecs                       Meaning
                                                     
-----------------------------------------------------------------------------------------------------
                                                     
‘'surrogatepass'’       utf-8, utf-16, utf-32,       Allow encoding and decoding surrogate code
                        utf-16-be, utf-16-le,        point (‘U+D800’ - ‘U+DFFF’) as normal code
                        utf-32-be, utf-32-le         point.  Otherwise these codecs treat the
                                                     presence of surrogate code point in
                                                     *note str: 169. as an error.
                                                     

Added in version 3.1: The ‘'surrogateescape'’ and ‘'surrogatepass'’
error handlers.

Cambiato nella versione 3.4: The ‘'surrogatepass'’ error handler now
works with utf-16* and utf-32* codecs.

Added in version 3.5: The ‘'namereplace'’ error handler.

Cambiato nella versione 3.5: The ‘'backslashreplace'’ error handler now
works with decoding and translating.

The set of allowed values can be extended by registering a new named
error handler:

 -- Funzione: codecs.register_error (name, error_handler, /)

     Register the error handling function 'error_handler' under the name
     'name'.  The 'error_handler' argument will be called during
     encoding and decoding in case of an error, when 'name' is specified
     as the errors parameter.

     For encoding, 'error_handler' will be called with a *note
     UnicodeEncodeError: 888. instance, which contains information about
     the location of the error.  The error handler must either raise
     this or a different exception, or return a tuple with a replacement
     for the unencodable part of the input and a position where encoding
     should continue.  The replacement may be either *note str: 169. or
     *note bytes: 192.  If the replacement is bytes, the encoder will
     simply copy them into the output buffer.  If the replacement is a
     string, the encoder will encode the replacement.  Encoding
     continues on original input at the specified position.  Negative
     position values will be treated as being relative to the end of the
     input string.  If the resulting position is out of bound an *note
     IndexError: 173c. will be raised.

     Decoding and translating works similarly, except *note
     UnicodeDecodeError: c0a. or *note UnicodeTranslateError: 18e5. will
     be passed to the handler and that the replacement from the error
     handler will be put into the output directly.

Previously registered error handlers (including the standard error
handlers) can be looked up by name:

 -- Funzione: codecs.lookup_error (name, /)

     Return the error handler previously registered under the name
     'name'.

     Raises a *note LookupError: 2633. in case the handler cannot be
     found.

The following standard error handlers are also made available as module
level functions:

 -- Funzione: codecs.strict_errors (exception)

     Implements the ‘'strict'’ error handling.

     Each encoding or decoding error raises a *note UnicodeError: 462.

 -- Funzione: codecs.ignore_errors (exception)

     Implements the ‘'ignore'’ error handling.

     Malformed data is ignored; encoding or decoding is continued
     without further notice.

 -- Funzione: codecs.replace_errors (exception)

     Implements the ‘'replace'’ error handling.

     Substitutes ‘?’ (ASCII character) for encoding errors or ‘�’
     (U+FFFD, the official REPLACEMENT CHARACTER) for decoding errors.

 -- Funzione: codecs.backslashreplace_errors (exception)

     Implements the ‘'backslashreplace'’ error handling.

     Malformed data is replaced by a backslashed escape sequence.  On
     encoding, use the hexadecimal form of Unicode code point with
     formats ‘\xHH’ ‘\uXXXX’ ‘\UXXXXXXXX’.  On decoding, use the
     hexadecimal form of byte value with format ‘\xHH’.

     Cambiato nella versione 3.5: Works with decoding and translating.

 -- Funzione: codecs.xmlcharrefreplace_errors (exception)

     Implements the ‘'xmlcharrefreplace'’ error handling (for encoding
     within *note text encoding: 25b7. only).

     The unencodable character is replaced by an appropriate XML/HTML
     numeric character reference, which is a decimal form of Unicode
     code point with format ‘&#NUM;’ .

 -- Funzione: codecs.namereplace_errors (exception)

     Implements the ‘'namereplace'’ error handling (for encoding within
     *note text encoding: 25b7. only).

     The unencodable character is replaced by a ‘\N{...}’ escape
     sequence.  The set of characters that appear in the braces is the
     Name property from Unicode Character Database.  For example, the
     German lowercase letter ‘'ß'’ will be converted to byte sequence
     ‘\N{LATIN SMALL LETTER SHARP S}’ .

     Added in version 3.5.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0383/


File: python.info,  Node: Stateless Encoding and Decoding,  Next: Incremental Encoding and Decoding,  Prev: Error Handlers,  Up: Codec Base Classes

5.7.2.3 Stateless Encoding and Decoding
.......................................

The base *note Codec: 283d. class defines these methods which also
define the function interfaces of the stateless encoder and decoder:

 -- Classe: codecs.Codec

      -- Metodo: encode (input, errors='strict')

          Encodes the object 'input' and returns a tuple (output object,
          length consumed).  For instance, *note text encoding: 25b7.
          converts a string object to a bytes object using a particular
          character set encoding (e.g., ‘cp1252’ or ‘iso-8859-1’).

          The 'errors' argument defines the error handling to apply.  It
          defaults to ‘'strict'’ handling.

          The method may not store state in the *note Codec: 283d.
          instance.  Use *note StreamWriter: 281e. for codecs which have
          to keep state in order to make encoding efficient.

          The encoder must be able to handle zero length input and
          return an empty object of the output object type in this
          situation.

      -- Metodo: decode (input, errors='strict')

          Decodes the object 'input' and returns a tuple (output object,
          length consumed).  For instance, for a *note text encoding:
          25b7, decoding converts a bytes object encoded using a
          particular character set encoding to a string object.

          For text encodings and bytes-to-bytes codecs, 'input' must be
          a bytes object or one which provides the read-only buffer
          interface – for example, buffer objects and memory mapped
          files.

          The 'errors' argument defines the error handling to apply.  It
          defaults to ‘'strict'’ handling.

          The method may not store state in the *note Codec: 283d.
          instance.  Use *note StreamReader: 281f. for codecs which have
          to keep state in order to make decoding efficient.

          The decoder must be able to handle zero length input and
          return an empty object of the output object type in this
          situation.


File: python.info,  Node: Incremental Encoding and Decoding,  Next: Stream Encoding and Decoding,  Prev: Stateless Encoding and Decoding,  Up: Codec Base Classes

5.7.2.4 Incremental Encoding and Decoding
.........................................

The *note IncrementalEncoder: 281a. and *note IncrementalDecoder: 281b.
classes provide the basic interface for incremental encoding and
decoding.  Encoding/decoding the input isn’t done with one call to the
stateless encoder/decoder function, but with multiple calls to the *note
encode(): 283f./*note decode(): 2840. method of the incremental
encoder/decoder.  The incremental encoder/decoder keeps track of the
encoding/decoding process during method calls.

The joined output of calls to the *note encode(): 283f./*note decode():
2840. method is the same as if all the single inputs were joined into
one, and this input was encoded/decoded with the stateless
encoder/decoder.

* Menu:

* IncrementalEncoder Objects::
* IncrementalDecoder Objects::


File: python.info,  Node: IncrementalEncoder Objects,  Next: IncrementalDecoder Objects,  Up: Incremental Encoding and Decoding

5.7.2.5 IncrementalEncoder Objects
..................................

The *note IncrementalEncoder: 281a. class is used for encoding an input
in multiple steps.  It defines the following methods which every
incremental encoder must define in order to be compatible with the
Python codec registry.

 -- Classe: codecs.IncrementalEncoder (errors='strict')

     Constructor for an *note IncrementalEncoder: 281a. instance.

     All incremental encoders must provide this constructor interface.
     They are free to add additional keyword arguments, but only the
     ones defined here are used by the Python codec registry.

     The *note IncrementalEncoder: 281a. may implement different error
     handling schemes by providing the 'errors' keyword argument.  See
     *note Error Handlers: 1b57. for possible values.

     The 'errors' argument will be assigned to an attribute of the same
     name.  Assigning to this attribute makes it possible to switch
     between different error handling strategies during the lifetime of
     the *note IncrementalEncoder: 281a. object.

      -- Metodo: encode (object, final=False)

          Encodes 'object' (taking the current state of the encoder into
          account) and returns the resulting encoded object.  If this is
          the last call to *note encode(): 1106. 'final' must be true
          (the default is false).

      -- Metodo: reset ()

          Reset the encoder to the initial state.  The output is
          discarded: call ‘.encode(object, final=True)’, passing an
          empty byte or text string if necessary, to reset the encoder
          and to get the output.

      -- Metodo: getstate ()

          Return the current state of the encoder which must be an
          integer.  The implementation should make sure that ‘0’ is the
          most common state.  (States that are more complicated than
          integers can be converted into an integer by
          marshaling/pickling the state and encoding the bytes of the
          resulting string into an integer.)

      -- Metodo: setstate (state)

          Set the state of the encoder to 'state'.  'state' must be an
          encoder state returned by *note getstate(): 2844.


File: python.info,  Node: IncrementalDecoder Objects,  Prev: IncrementalEncoder Objects,  Up: Incremental Encoding and Decoding

5.7.2.6 IncrementalDecoder Objects
..................................

The *note IncrementalDecoder: 281b. class is used for decoding an input
in multiple steps.  It defines the following methods which every
incremental decoder must define in order to be compatible with the
Python codec registry.

 -- Classe: codecs.IncrementalDecoder (errors='strict')

     Constructor for an *note IncrementalDecoder: 281b. instance.

     All incremental decoders must provide this constructor interface.
     They are free to add additional keyword arguments, but only the
     ones defined here are used by the Python codec registry.

     The *note IncrementalDecoder: 281b. may implement different error
     handling schemes by providing the 'errors' keyword argument.  See
     *note Error Handlers: 1b57. for possible values.

     The 'errors' argument will be assigned to an attribute of the same
     name.  Assigning to this attribute makes it possible to switch
     between different error handling strategies during the lifetime of
     the *note IncrementalDecoder: 281b. object.

      -- Metodo: decode (object, final=False)

          Decodes 'object' (taking the current state of the decoder into
          account) and returns the resulting decoded object.  If this is
          the last call to *note decode(): 1107. 'final' must be true
          (the default is false).  If 'final' is true the decoder must
          decode the input completely and must flush all buffers.  If
          this isn’t possible (e.g.  because of incomplete byte
          sequences at the end of the input) it must initiate error
          handling just like in the stateless case (which might raise an
          exception).

      -- Metodo: reset ()

          Reset the decoder to the initial state.

      -- Metodo: getstate ()

          Return the current state of the decoder.  This must be a tuple
          with two items, the first must be the buffer containing the
          still undecoded input.  The second must be an integer and can
          be additional state info.  (The implementation should make
          sure that ‘0’ is the most common additional state info.)  If
          this additional state info is ‘0’ it must be possible to set
          the decoder to the state which has no input buffered and ‘0’
          as the additional state info, so that feeding the previously
          buffered input to the decoder returns it to the previous state
          without producing any output.  (Additional state info that is
          more complicated than integers can be converted into an
          integer by marshaling/pickling the info and encoding the bytes
          of the resulting string into an integer.)

      -- Metodo: setstate (state)

          Set the state of the decoder to 'state'.  'state' must be a
          decoder state returned by *note getstate(): 2849.


File: python.info,  Node: Stream Encoding and Decoding,  Prev: Incremental Encoding and Decoding,  Up: Codec Base Classes

5.7.2.7 Stream Encoding and Decoding
....................................

The *note StreamWriter: 281e. and *note StreamReader: 281f. classes
provide generic working interfaces which can be used to implement new
encoding submodules very easily.  See ‘encodings.utf_8’ for an example
of how this is done.

* Menu:

* StreamWriter Objects::
* StreamReader Objects::
* StreamReaderWriter Objects::
* StreamRecoder Objects::


File: python.info,  Node: StreamWriter Objects,  Next: StreamReader Objects,  Up: Stream Encoding and Decoding

5.7.2.8 StreamWriter Objects
............................

The *note StreamWriter: 281e. class is a subclass of *note Codec: 283d.
and defines the following methods which every stream writer must define
in order to be compatible with the Python codec registry.

 -- Classe: codecs.StreamWriter (stream, errors='strict')

     Constructor for a *note StreamWriter: 281e. instance.

     All stream writers must provide this constructor interface.  They
     are free to add additional keyword arguments, but only the ones
     defined here are used by the Python codec registry.

     The 'stream' argument must be a file-like object open for writing
     text or binary data, as appropriate for the specific codec.

     The *note StreamWriter: 281e. may implement different error
     handling schemes by providing the 'errors' keyword argument.  See
     *note Error Handlers: 1b57. for the standard error handlers the
     underlying stream codec may support.

     The 'errors' argument will be assigned to an attribute of the same
     name.  Assigning to this attribute makes it possible to switch
     between different error handling strategies during the lifetime of
     the *note StreamWriter: 281e. object.

      -- Metodo: write (object)

          Writes the object’s contents encoded to the stream.

      -- Metodo: writelines (list)

          Writes the concatenated iterable of strings to the stream
          (possibly by reusing the *note write(): 284e. method).
          Infinite or very large iterables are not supported.  The
          standard bytes-to-bytes codecs do not support this method.

      -- Metodo: reset ()

          Resets the codec buffers used for keeping internal state.

          Calling this method should ensure that the data on the output
          is put into a clean state that allows appending of new fresh
          data without having to rescan the whole stream to recover
          state.

In addition to the above methods, the *note StreamWriter: 281e. must
also inherit all other methods and attributes from the underlying
stream.


File: python.info,  Node: StreamReader Objects,  Next: StreamReaderWriter Objects,  Prev: StreamWriter Objects,  Up: Stream Encoding and Decoding

5.7.2.9 StreamReader Objects
............................

The *note StreamReader: 281f. class is a subclass of *note Codec: 283d.
and defines the following methods which every stream reader must define
in order to be compatible with the Python codec registry.

 -- Classe: codecs.StreamReader (stream, errors='strict')

     Constructor for a *note StreamReader: 281f. instance.

     All stream readers must provide this constructor interface.  They
     are free to add additional keyword arguments, but only the ones
     defined here are used by the Python codec registry.

     The 'stream' argument must be a file-like object open for reading
     text or binary data, as appropriate for the specific codec.

     The *note StreamReader: 281f. may implement different error
     handling schemes by providing the 'errors' keyword argument.  See
     *note Error Handlers: 1b57. for the standard error handlers the
     underlying stream codec may support.

     The 'errors' argument will be assigned to an attribute of the same
     name.  Assigning to this attribute makes it possible to switch
     between different error handling strategies during the lifetime of
     the *note StreamReader: 281f. object.

     The set of allowed values for the 'errors' argument can be extended
     with *note register_error(): 16a2.

      -- Metodo: read (size=-1, chars=-1, firstline=False)

          Decodes data from the stream and returns the resulting object.

          The 'chars' argument indicates the number of decoded code
          points or bytes to return.  The *note read(): 2853. method
          will never return more data than requested, but it might
          return less, if there is not enough available.

          The 'size' argument indicates the approximate maximum number
          of encoded bytes or code points to read for decoding.  The
          decoder can modify this setting as appropriate.  The default
          value -1 indicates to read and decode as much as possible.
          This parameter is intended to prevent having to decode huge
          files in one step.

          The 'firstline' flag indicates that it would be sufficient to
          only return the first line, if there are decoding errors on
          later lines.

          The method should use a greedy read strategy meaning that it
          should read as much data as is allowed within the definition
          of the encoding and the given size, e.g.  if optional encoding
          endings or state markers are available on the stream, these
          should be read too.

      -- Metodo: readline (size=None, keepends=True)

          Read one line from the input stream and return the decoded
          data.

          'size', if given, is passed as size argument to the stream’s
          *note read(): 2853. method.

          If 'keepends' is false line-endings will be stripped from the
          lines returned.

      -- Metodo: readlines (sizehint=None, keepends=True)

          Read all lines available on the input stream and return them
          as a list of lines.

          Line-endings are implemented using the codec’s *note decode():
          1107. method and are included in the list entries if
          'keepends' is true.

          'sizehint', if given, is passed as the 'size' argument to the
          stream’s *note read(): 2853. method.

      -- Metodo: reset ()

          Resets the codec buffers used for keeping internal state.

          Note that no stream repositioning should take place.  This
          method is primarily intended to be able to recover from
          decoding errors.

In addition to the above methods, the *note StreamReader: 281f. must
also inherit all other methods and attributes from the underlying
stream.


File: python.info,  Node: StreamReaderWriter Objects,  Next: StreamRecoder Objects,  Prev: StreamReader Objects,  Up: Stream Encoding and Decoding

5.7.2.10 StreamReaderWriter Objects
...................................

The *note StreamReaderWriter: 2827. is a convenience class that allows
wrapping streams which work in both read and write modes.

The design is such that one can use the factory functions returned by
the *note lookup(): b5e. function to construct the instance.

 -- Classe: codecs.StreamReaderWriter (stream, Reader, Writer,
          errors='strict')

     Creates a *note StreamReaderWriter: 2827. instance.  'stream' must
     be a file-like object.  'Reader' and 'Writer' must be factory
     functions or classes providing the *note StreamReader: 281f. and
     *note StreamWriter: 281e. interface resp.  Error handling is done
     in the same way as defined for the stream readers and writers.

*note StreamReaderWriter: 2827. instances define the combined interfaces
of *note StreamReader: 281f. and *note StreamWriter: 281e. classes.
They inherit all other methods and attributes from the underlying
stream.


File: python.info,  Node: StreamRecoder Objects,  Prev: StreamReaderWriter Objects,  Up: Stream Encoding and Decoding

5.7.2.11 StreamRecoder Objects
..............................

The *note StreamRecoder: 1dbc. translates data from one encoding to
another, which is sometimes useful when dealing with different encoding
environments.

The design is such that one can use the factory functions returned by
the *note lookup(): b5e. function to construct the instance.

 -- Classe: codecs.StreamRecoder (stream, encode, decode, Reader,
          Writer, errors='strict')

     Creates a *note StreamRecoder: 1dbc. instance which implements a
     two-way conversion: 'encode' and 'decode' work on the frontend —
     the data visible to code calling *note read(): 2853. and *note
     write(): 284e, while 'Reader' and 'Writer' work on the backend —
     the data in 'stream'.

     You can use these objects to do transparent transcodings, e.g.,
     from Latin-1 to UTF-8 and back.

     The 'stream' argument must be a file-like object.

     The 'encode' and 'decode' arguments must adhere to the *note Codec:
     283d. interface.  'Reader' and 'Writer' must be factory functions
     or classes providing objects of the *note StreamReader: 281f. and
     *note StreamWriter: 281e. interface respectively.

     Error handling is done in the same way as defined for the stream
     readers and writers.

*note StreamRecoder: 1dbc. instances define the combined interfaces of
*note StreamReader: 281f. and *note StreamWriter: 281e. classes.  They
inherit all other methods and attributes from the underlying stream.


File: python.info,  Node: Encodings and Unicode,  Next: Standard Encodings,  Prev: Codec Base Classes,  Up: codecs — Codec registry and base classes

5.7.2.12 Encodings and Unicode
..............................

Strings are stored internally as sequences of code points in range
‘U+0000’–‘U+10FFFF’.  (See PEP 393(1) for more details about the
implementation.)  Once a string object is used outside of CPU and
memory, endianness and how these arrays are stored as bytes become an
issue.  As with other codecs, serialising a string into a sequence of
bytes is known as 'encoding', and recreating the string from the
sequence of bytes is known as 'decoding'.  There are a variety of
different text serialisation codecs, which are collectivity referred to
as *note text encodings: 25b7.

The simplest text encoding (called ‘'latin-1'’ or ‘'iso-8859-1'’) maps
the code points 0–255 to the bytes ‘0x0’–‘0xff’, which means that a
string object that contains code points above ‘U+00FF’ can’t be encoded
with this codec.  Doing so will raise a *note UnicodeEncodeError: 888.
that looks like the following (although the details of the error message
may differ): ‘UnicodeEncodeError: 'latin-1' codec can't encode character
'\u1234' in position 3: ordinal not in range(256)’.

There’s another group of encodings (the so called charmap encodings)
that choose a different subset of all Unicode code points and how these
code points are mapped to the bytes ‘0x0’–‘0xff’.  To see how this is
done simply open e.g.  ‘encodings/cp1252.py’ (which is an encoding that
is used primarily on Windows).  There’s a string constant with 256
characters that shows you which character is mapped to which byte value.

All of these encodings can only encode 256 of the 1114112 code points
defined in Unicode.  A simple and straightforward way that can store
each Unicode code point, is to store each code point as four consecutive
bytes.  There are two possibilities: store the bytes in big endian or in
little endian order.  These two encodings are called ‘UTF-32-BE’ and
‘UTF-32-LE’ respectively.  Their disadvantage is that if, for example,
you use ‘UTF-32-BE’ on a little endian machine you will always have to
swap bytes on encoding and decoding.  Python’s ‘UTF-16’ and ‘UTF-32’
codecs avoid this problem by using the platform’s native byte order when
no BOM is present.  Python follows prevailing platform practice, so
native-endian data round-trips without redundant byte swapping, even
though the Unicode Standard defaults to big-endian when the byte order
is unspecified.  When these bytes are read by a CPU with a different
endianness, the bytes have to be swapped.  To be able to detect the
endianness of a ‘UTF-16’ or ‘UTF-32’ byte sequence, a BOM («Byte Order
Mark») is used.  This is the Unicode character ‘U+FEFF’.  This character
can be prepended to every ‘UTF-16’ or ‘UTF-32’ byte sequence.  The byte
swapped version of this character (‘0xFFFE’) is an illegal character
that may not appear in a Unicode text.  When the first character of a
‘UTF-16’ or ‘UTF-32’ byte sequence is ‘U+FFFE’, the bytes have to be
swapped on decoding.

Unfortunately the character ‘U+FEFF’ had a second purpose as a ‘ZERO
WIDTH NO-BREAK SPACE’: a character that has no width and doesn’t allow a
word to be split.  It can e.g.  be used to give hints to a ligature
algorithm.  With Unicode 4.0 using ‘U+FEFF’ as a ‘ZERO WIDTH NO-BREAK
SPACE’ has been deprecated (with ‘U+2060’ (‘WORD JOINER’) assuming this
role).  Nevertheless Unicode software still must be able to handle
‘U+FEFF’ in both roles: as a BOM it’s a device to determine the storage
layout of the encoded bytes, and vanishes once the byte sequence has
been decoded into a string; as a ‘ZERO WIDTH NO-BREAK SPACE’ it’s a
normal character that will be decoded like any other.

There’s another encoding that is able to encode the full range of
Unicode characters: UTF-8.  UTF-8 is an 8-bit encoding, which means
there are no issues with byte order in UTF-8.  Each byte in a UTF-8 byte
sequence consists of two parts: marker bits (the most significant bits)
and payload bits.  The marker bits are a sequence of zero to four ‘1’
bits followed by a ‘0’ bit.  Unicode characters are encoded like this
(with x being payload bits, which when concatenated give the Unicode
character):

Range                                   Encoding
                                        
-------------------------------------------------------------------------------------------
                                        
‘U-00000000’ … ‘U-0000007F’             0xxxxxxx
                                        
                                        
‘U-00000080’ … ‘U-000007FF’             110xxxxx 10xxxxxx
                                        
                                        
‘U-00000800’ … ‘U-0000FFFF’             1110xxxx 10xxxxxx 10xxxxxx
                                        
                                        
‘U-00010000’ … ‘U-0010FFFF’             11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
                                        

The least significant bit of the Unicode character is the rightmost x
bit.

As UTF-8 is an 8-bit encoding no BOM is required and any ‘U+FEFF’
character in the decoded string (even if it’s the first character) is
treated as a ‘ZERO WIDTH NO-BREAK SPACE’.

Without external information it’s impossible to reliably determine which
encoding was used for encoding a string.  Each charmap encoding can
decode any random byte sequence.  However that’s not possible with
UTF-8, as UTF-8 byte sequences have a structure that doesn’t allow
arbitrary byte sequences.  To increase the reliability with which a
UTF-8 encoding can be detected, Microsoft invented a variant of UTF-8
(that Python calls ‘"utf-8-sig"’) for its Notepad program: Before any of
the Unicode characters is written to the file, a UTF-8 encoded BOM
(which looks like this as a byte sequence: ‘0xef’, ‘0xbb’, ‘0xbf’) is
written.  As it’s rather improbable that any charmap encoded file starts
with these byte values (which would e.g.  map to

          LATIN SMALL LETTER I WITH DIAERESIS
          RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
          INVERTED QUESTION MARK

in iso-8859-1), this increases the probability that a ‘utf-8-sig’
encoding can be correctly guessed from the byte sequence.  So here the
BOM is not used to be able to determine the byte order used for
generating the byte sequence, but as a signature that helps in guessing
the encoding.  On encoding the utf-8-sig codec will write ‘0xef’,
‘0xbb’, ‘0xbf’ as the first three bytes to the file.  On decoding
‘utf-8-sig’ will skip those three bytes if they appear as the first
three bytes in the file.  In UTF-8, the use of the BOM is discouraged
and should generally be avoided.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0393/


File: python.info,  Node: Standard Encodings,  Next: Python Specific Encodings,  Prev: Encodings and Unicode,  Up: codecs — Codec registry and base classes

5.7.2.13 Standard Encodings
...........................

Python comes with a number of codecs built-in, either implemented as C
functions or with dictionaries as mapping tables.  The following table
lists the codecs by name, together with a few common aliases, and the
languages for which the encoding is likely used.  Neither the list of
aliases nor the list of languages is meant to be exhaustive.  Notice
that spelling alternatives that only differ in case or use a hyphen
instead of an underscore are also valid aliases because they are
equivalent when normalized by *note normalize_encoding(): 9ff.  For
example, ‘'utf-8'’ is a valid alias for the ‘'utf_8'’ codec.

     Nota: The below table lists the most common aliases, for a complete
     list refer to the source aliases.py(1) file.

On Windows, ‘cpXXX’ codecs are available for all code pages.  But only
codecs listed in the following table are guarantead to exist on other
platforms.

'Dettaglio dell’implementazione di CPython:' Some common encodings can
bypass the codecs lookup machinery to improve performance.  These
optimization opportunities are only recognized by CPython for a limited
set of (case insensitive) aliases: utf-8, utf8, latin-1, latin1,
iso-8859-1, iso8859-1, mbcs (Windows only), ascii, us-ascii, utf-16,
utf16, utf-32, utf32, and the same using underscores instead of dashes.
Using alternative aliases for these encodings may result in slower
execution.

Cambiato nella versione 3.6: Optimization opportunity recognized for
us-ascii.

Many of the character sets support the same languages.  They vary in
individual characters (e.g.  whether the EURO SIGN is supported or not),
and in the assignment of characters to code positions.  For the European
languages in particular, the following variants typically exist:

   * an ISO 8859 codeset

   * a Microsoft Windows code page, which is typically derived from an
     8859 codeset, but replaces control characters with additional
     graphic characters

   * an IBM EBCDIC code page

   * an IBM PC code page, which is ASCII compatible

Codec                 Aliases                              Languages
                                                           
------------------------------------------------------------------------------------------------
                                                           
ascii                 646, us-ascii                        English
                                                           
                                                           
big5                  big5-tw, csbig5                      Traditional Chinese
                                                           
                                                           
big5hkscs             big5-hkscs, hkscs                    Traditional Chinese
                                                           
                                                           
cp037                 IBM037, IBM039                       English
                                                           
                                                           
cp273                 273, IBM273, csIBM273                German
                                                           
                                                           Added in version 3.4.
                                                           
                                                           
cp424                 EBCDIC-CP-HE, IBM424                 Hebrew
                                                           
                                                           
cp437                 437, IBM437                          English
                                                           
                                                           
cp500                 EBCDIC-CP-BE, EBCDIC-CP-CH, IBM500   Western Europe
                                                           
                                                           
cp720                                                      Arabic
                                                           
                                                           
cp737                                                      Greek
                                                           
                                                           
cp775                 IBM775                               Baltic languages
                                                           
                                                           
cp850                 850, IBM850                          Western Europe
                                                           
                                                           
cp852                 852, IBM852                          Central and Eastern Europe
                                                           
                                                           
cp855                 855, IBM855                          Belarusian, Bulgarian, Macedonian,
                                                           Russian, Serbian
                                                           
                                                           
cp856                                                      Hebrew
                                                           
                                                           
cp857                 857, IBM857                          Turkish
                                                           
                                                           
cp858                 858, IBM858                          Western Europe
                                                           
                                                           
cp860                 860, IBM860                          Portuguese
                                                           
                                                           
cp861                 861, CP-IS, IBM861                   Icelandic
                                                           
                                                           
cp862                 862, IBM862                          Hebrew
                                                           
                                                           
cp863                 863, IBM863                          Canadian
                                                           
                                                           
cp864                 IBM864                               Arabic
                                                           
                                                           
cp865                 865, IBM865                          Danish, Norwegian
                                                           
                                                           
cp866                 866, IBM866                          Russian
                                                           
                                                           
cp869                 869, CP-GR, IBM869                   Greek
                                                           
                                                           
cp874                                                      Thai
                                                           
                                                           
cp875                                                      Greek
                                                           
                                                           
cp932                 932, ms932, mskanji, ms-kanji,       Japanese
                      windows-31j                          
                      
                                                           
cp949                 949, ms949, uhc                      Korean
                                                           
                                                           
cp950                 950, ms950                           Traditional Chinese
                                                           
                                                           
cp1006                                                     Urdu
                                                           
                                                           
cp1026                ibm1026                              Turkish
                                                           
                                                           
cp1125                1125, ibm1125, cp866u, ruscii        Ukrainian
                                                           
                                                           Added in version 3.4.
                                                           
                                                           
cp1140                ibm1140                              Western Europe
                                                           
                                                           
cp1250                windows-1250                         Central and Eastern Europe
                                                           
                                                           
cp1251                windows-1251                         Belarusian, Bulgarian, Macedonian,
                                                           Russian, Serbian
                                                           
                                                           
cp1252                windows-1252                         Western Europe
                                                           
                                                           
cp1253                windows-1253                         Greek
                                                           
                                                           
cp1254                windows-1254                         Turkish
                                                           
                                                           
cp1255                windows-1255                         Hebrew
                                                           
                                                           
cp1256                windows-1256                         Arabic
                                                           
                                                           
cp1257                windows-1257                         Baltic languages
                                                           
                                                           
cp1258                windows-1258                         Vietnamese
                                                           
                                                           
euc_jp                eucjp, ujis, u-jis                   Japanese
                                                           
                                                           
euc_jis_2004          jisx0213, eucjis2004                 Japanese
                                                           
                                                           
euc_jisx0213          eucjisx0213                          Japanese
                                                           
                                                           
euc_kr                euckr, korean, ksc5601, ks_c-5601,   Korean
                      ks_c-5601-1987, ksx1001, ks_x-1001   
                      
                                                           
gb2312                chinese, csiso58gb231280, euc-cn,    Simplified Chinese
                      euccn, eucgb2312-cn, gb2312-1980,    
                      gb2312-80, iso-ir-58
                      
                                                           
gbk                   936, cp936, ms936                    Unified Chinese
                                                           
                                                           
gb18030               gb18030-2000                         Unified Chinese
                                                           
                                                           
hz                    hzgb, hz-gb, hz-gb-2312              Simplified Chinese
                                                           
                                                           
iso2022_jp            csiso2022jp, iso2022jp,              Japanese
                      iso-2022-jp                          
                      
                                                           
iso2022_jp_1          iso2022jp-1, iso-2022-jp-1           Japanese
                                                           
                                                           
iso2022_jp_2          iso2022jp-2, iso-2022-jp-2           Japanese, Korean, Simplified
                                                           Chinese, Western Europe, Greek
                                                           
                                                           
iso2022_jp_2004       iso2022jp-2004, iso-2022-jp-2004     Japanese
                                                           
                                                           
iso2022_jp_3          iso2022jp-3, iso-2022-jp-3           Japanese
                                                           
                                                           
iso2022_jp_ext        iso2022jp-ext, iso-2022-jp-ext       Japanese
                                                           
                                                           
iso2022_kr            csiso2022kr, iso2022kr,              Korean
                      iso-2022-kr                          
                      
                                                           
latin_1               iso-8859-1, iso8859-1, 8859,         Western Europe
                      cp819, latin, latin1, L1             
                      
                                                           
iso8859_2             iso-8859-2, latin2, L2               Central and Eastern Europe
                                                           
                                                           
iso8859_3             iso-8859-3, latin3, L3               Esperanto, Maltese
                                                           
                                                           
iso8859_4             iso-8859-4, latin4, L4               Northern Europe
                                                           
                                                           
iso8859_5             iso-8859-5, cyrillic                 Belarusian, Bulgarian, Macedonian,
                                                           Russian, Serbian
                                                           
                                                           
iso8859_6             iso-8859-6, arabic                   Arabic
                                                           
                                                           
iso8859_7             iso-8859-7, greek, greek8            Greek
                                                           
                                                           
iso8859_8             iso-8859-8, hebrew                   Hebrew
                                                           
                                                           
iso8859_9             iso-8859-9, latin5, L5               Turkish
                                                           
                                                           
iso8859_10            iso-8859-10, latin6, L6              Nordic languages
                                                           
                                                           
iso8859_11            iso-8859-11, thai                    Thai languages
                                                           
                                                           
iso8859_13            iso-8859-13, latin7, L7              Baltic languages
                                                           
                                                           
iso8859_14            iso-8859-14, latin8, L8              Celtic languages
                                                           
                                                           
iso8859_15            iso-8859-15, latin9, L9              Western Europe
                                                           
                                                           
iso8859_16            iso-8859-16, latin10, L10            South-Eastern Europe
                                                           
                                                           
johab                 cp1361, ms1361                       Korean
                                                           
                                                           
koi8_r                                                     Russian
                                                           
                                                           
koi8_t                                                     Tajik
                                                           
                                                           Added in version 3.5.
                                                           
                                                           
koi8_u                                                     Ukrainian
                                                           
                                                           
kz1048                kz_1048, strk1048_2002, rk1048       Kazakh
                                                           
                                                           Added in version 3.5.
                                                           
                                                           
mac_cyrillic          maccyrillic                          Belarusian, Bulgarian, Macedonian,
                                                           Russian, Serbian
                                                           
                                                           
mac_greek             macgreek                             Greek
                                                           
                                                           
mac_iceland           maciceland                           Icelandic
                                                           
                                                           
mac_latin2            maclatin2, maccentraleurope,         Central and Eastern Europe
                      mac_centeuro                         
                      
                                                           
mac_roman             macroman, macintosh                  Western Europe
                                                           
                                                           
mac_turkish           macturkish                           Turkish
                                                           
                                                           
ptcp154               csptcp154, pt154, cp154,             Kazakh
                      cyrillic-asian                       
                      
                                                           
shift_jis             csshiftjis, shiftjis, sjis, s_jis    Japanese
                                                           
                                                           
shift_jis_2004        shiftjis2004, sjis_2004, sjis2004    Japanese
                                                           
                                                           
shift_jisx0213        shiftjisx0213, sjisx0213,            Japanese
                      s_jisx0213                           
                      
                                                           
utf_32                U32, utf32                           all languages
                                                           
                                                           
utf_32_be             UTF-32BE                             all languages
                                                           
                                                           
utf_32_le             UTF-32LE                             all languages
                                                           
                                                           
utf_16                U16, utf16                           all languages
                                                           
                                                           
utf_16_be             UTF-16BE                             all languages
                                                           
                                                           
utf_16_le             UTF-16LE                             all languages
                                                           
                                                           
utf_7                 U7, unicode-1-1-utf-7                all languages
                                                           
                                                           
utf_8                 U8, UTF, utf8, cp65001               all languages
                                                           
                                                           
utf_8_sig                                                  all languages
                                                           

Cambiato nella versione 3.4: The utf-16* and utf-32* encoders no longer
allow surrogate code points (‘U+D800’–‘U+DFFF’) to be encoded.  The
utf-32* decoders no longer decode byte sequences that correspond to
surrogate code points.

Cambiato nella versione 3.8: ‘cp65001’ is now an alias to ‘utf_8’.

Cambiato nella versione 3.14: On Windows, ‘cpXXX’ codecs are now
available for all code pages.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/encodings/aliases.py


File: python.info,  Node: Python Specific Encodings,  Next: encodings — Encodings package,  Prev: Standard Encodings,  Up: codecs — Codec registry and base classes

5.7.2.14 Python Specific Encodings
..................................

A number of predefined codecs are specific to Python, so their codec
names have no meaning outside Python.  These are listed in the tables
below based on the expected input and output types (note that while text
encodings are the most common use case for codecs, the underlying codec
infrastructure supports arbitrary data transforms rather than just text
encodings).  For asymmetric codecs, the stated meaning describes the
encoding direction.

* Menu:

* Text Encodings::
* Binary Transforms::
* Standalone Codec Functions::
* Text Transforms::


File: python.info,  Node: Text Encodings,  Next: Binary Transforms,  Up: Python Specific Encodings

5.7.2.15 Text Encodings
.......................

The following codecs provide *note str: 169. to *note bytes: 192.
encoding and *note bytes-like object: 193. to *note str: 169. decoding,
similar to the Unicode text encodings.

Codec                    Aliases       Meaning
                                       
-----------------------------------------------------------------------
                                       
idna                                   Implement RFC 3490(1), see
                                       also
                                       *note encodings.idna: 56.
                                       Only ‘errors='strict'’ is
                                       supported.
                                       
                                       
mbcs                     ansi, dbcs    Windows only: Encode the
                                       operand according to the ANSI
                                       codepage (CP_ACP).
                                       
                                       
oem                                    Windows only: Encode the
                                       operand according to the OEM
                                       codepage (CP_OEMCP).
                                       
                                       Added in version 3.6.
                                       
                                       
palmos                                 Encoding of PalmOS 3.5.
                                       
                                       
punycode                               Implement RFC 3492(2).
                                       Stateful codecs are not
                                       supported.
                                       
                                       
raw_unicode_escape                     Latin-1 encoding with
                                       ‘\uXXXX’ and ‘\UXXXXXXXX’ for
                                       other code points.  Existing
                                       backslashes are not escaped
                                       in any way.  It is used in
                                       the Python pickle protocol.
                                       
                                       
undefined                              This Codec should only be
                                       used for testing purposes.
                                       
                                       Raise an exception for all
                                       conversions, even empty
                                       strings.  The error handler
                                       is ignored.
                                       
                                       
unicode_escape                         Encoding suitable as the
                                       contents of a Unicode literal
                                       in ASCII-encoded Python
                                       source code, except that
                                       quotes are not escaped.
                                       Decode from Latin-1 source
                                       code.  Beware that Python
                                       source code actually uses
                                       UTF-8 by default.
                                       

Cambiato nella versione 3.8: «unicode_internal» codec is removed.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc3490.html

   (2) https://datatracker.ietf.org/doc/html/rfc3492.html


File: python.info,  Node: Binary Transforms,  Next: Standalone Codec Functions,  Prev: Text Encodings,  Up: Python Specific Encodings

5.7.2.16 Binary Transforms
..........................

The following codecs provide binary transforms: *note bytes-like object:
193. to *note bytes: 192. mappings.  They are not supported by *note
bytes.decode(): ad5. (which only produces *note str: 169. output).

Codec                      Aliases                Meaning                            Encoder / decoder
                                                                                     
------------------------------------------------------------------------------------------------------------------------
                                                                                     
base64_codec (1)           base64, base_64        Convert the operand to multiline   *note base64.encodebytes(): b4e.
                                                  MIME base64 (the result always     /
                                                  includes a trailing ‘'\n'’).       *note base64.decodebytes(): b4f.
                                                                                     
                                                  Cambiato nella versione 3.4:
                                                  accepts any
                                                  *note bytes-like object: 193. as
                                                  input for encoding and decoding
                                                  
                                                                                     
bz2_codec                  bz2                    Compress the operand using bz2.    *note bz2.compress(): 2861. /
                                                                                     *note bz2.decompress(): 1296.
                                                                                     
                                                                                     
hex_codec                  hex                    Convert the operand to             *note binascii.b2a_hex(): 2862.
                                                  hexadecimal representation, with   /
                                                  two digits per byte.               *note binascii.a2b_hex(): 2863.
                                                                                     
                                                                                     
quopri_codec               quopri,                Convert the operand to MIME        *note quopri.encode(): 2864.
                           quotedprintable,       quoted printable.                  with ‘quotetabs=True’ /
                           quoted_printable                                          *note quopri.decode(): 2865.
                                                                                     
                                                                                     
uu_codec                   uu                     Convert the operand using
                                                  uuencode.
                                                  
                                                                                     
zlib_codec                 zip, zlib              Compress the operand using gzip.   *note zlib.compress(): 850. /
                                                                                     *note zlib.decompress(): f0b.
                                                                                     

Added in version 3.2: Restoration of the binary transforms.

Cambiato nella versione 3.4: Restoration of the aliases for the binary
transforms.

   ---------- Footnotes ----------

   (1) In addition to *note bytes-like objects: 193, ‘'base64_codec'’
also accepts ASCII-only instances of *note str: 169. for decoding


File: python.info,  Node: Standalone Codec Functions,  Next: Text Transforms,  Prev: Binary Transforms,  Up: Python Specific Encodings

5.7.2.17 Standalone Codec Functions
...................................

The following functions provide encoding and decoding functionality
similar to codecs, but are not available as named codecs through *note
codecs.encode(): 1106. or *note codecs.decode(): 1107.  They are used
internally (for example, by *note pickle: ab.) and behave similarly to
the ‘string_escape’ codec that was removed in Python 3.

 -- Funzione: codecs.escape_encode (input, errors=None)

     Encode 'input' using escape sequences.  Similar to how *note
     repr(): 1c1. on bytes produces escaped byte values.

     'input' must be a *note bytes: 192. object.

     Returns a tuple ‘(output, length)’ where 'output' is a *note bytes:
     192. object and 'length' is the number of bytes consumed.

 -- Funzione: codecs.escape_decode (input, errors=None)

     Decode 'input' from escape sequences back to the original bytes.

     'input' must be a *note bytes-like object: 193.

     Returns a tuple ‘(output, length)’ where 'output' is a *note bytes:
     192. object and 'length' is the number of bytes consumed.


File: python.info,  Node: Text Transforms,  Prev: Standalone Codec Functions,  Up: Python Specific Encodings

5.7.2.18 Text Transforms
........................

The following codec provides a text transform: a *note str: 169. to
*note str: 169. mapping.  It is not supported by *note str.encode():
ad4. (which only produces *note bytes: 192. output).

Codec                    Aliases       Meaning
                                       
-----------------------------------------------------------------------
                                       
rot_13                   rot13         Return the Caesar-cypher
                                       encryption of the operand.
                                       

Added in version 3.2: Restoration of the ‘rot_13’ text transform.

Cambiato nella versione 3.4: Restoration of the ‘rot13’ alias.


File: python.info,  Node: encodings — Encodings package,  Next: encodings idna — Internationalized Domain Names in Applications,  Prev: Python Specific Encodings,  Up: codecs — Codec registry and base classes

5.7.2.19 ‘encodings’ — Encodings package
........................................

This module implements the following functions:

 -- Funzione: encodings.normalize_encoding (encoding)

     Normalize encoding name 'encoding'.

     Normalization works as follows: all non-alphanumeric characters
     except the dot used for Python package names are collapsed and
     replaced with a single underscore, leading and trailing underscores
     are removed.  For example, ‘' -;#'’ becomes ‘'_'’.

     Note that 'encoding' should be ASCII only.

     Nota: The following functions should not be used directly, except
     for testing purposes; *note codecs.lookup(): b5e. should be used
     instead.

 -- Funzione: encodings.search_function (encoding)

     Search for the codec module corresponding to the given encoding
     name 'encoding'.

     This function first normalizes the 'encoding' using *note
     normalize_encoding(): 9ff, then looks for a corresponding alias.
     It attempts to import a codec module from the encodings package
     using either the alias or the normalized name.  If the module is
     found and defines a valid ‘getregentry()’ function that returns a
     *note codecs.CodecInfo: 1a54. object, the codec is cached and
     returned.

     If the codec module defines a ‘getaliases()’ function any returned
     aliases are registered for future use.

 -- Funzione: encodings.win32_code_page_search_function (encoding)

     Search for a Windows code page encoding 'encoding' of the form
     ‘cpXXXX’.

     If the code page is valid and supported, return a *note
     codecs.CodecInfo: 1a54. object for it.

     *note Availability: 2128.: Windows.

     Added in version 3.14.

This module implements the following exception:

 -- Eccezione: encodings.CodecRegistryError

     Raised when a codec is invalid or incompatible.


File: python.info,  Node: encodings idna — Internationalized Domain Names in Applications,  Next: encodings mbcs — Windows ANSI codepage,  Prev: encodings — Encodings package,  Up: codecs — Codec registry and base classes

5.7.2.20 ‘encodings.idna’ — Internationalized Domain Names in Applications
..........................................................................

This module implements RFC 3490(1) (Internationalized Domain Names in
Applications) and RFC 3492(2) (Nameprep: A Stringprep Profile for
Internationalized Domain Names (IDN)). It builds upon the ‘punycode’
encoding and *note stringprep: da.

If you need the IDNA 2008 standard from RFC 5891(3) and RFC 5895(4), use
the third-party idna(5) module.

These RFCs together define a protocol to support non-ASCII characters in
domain names.  A domain name containing non-ASCII characters (such as
‘www.Alliancefrançaise.nu’) is converted into an ASCII-compatible
encoding (ACE, such as ‘www.xn--alliancefranaise-npb.nu’).  The ACE form
of the domain name is then used in all places where arbitrary characters
are not allowed by the protocol, such as DNS queries, HTTP ‘Host’
fields, and so on.  This conversion is carried out in the application;
if possible invisible to the user: The application should transparently
convert Unicode domain labels to IDNA on the wire, and convert back ACE
labels to Unicode before presenting them to the user.

Python supports this conversion in several ways: the ‘idna’ codec
performs conversion between Unicode and ACE, separating an input string
into labels based on the separator characters defined in section 3.1 of
RFC 3490(6) and converting each label to ACE as required, and conversely
separating an input byte string into labels based on the ‘.’ separator
and converting any ACE labels found into unicode.  Furthermore, the
*note socket: d1. module transparently converts Unicode host names to
ACE, so that applications need not be concerned about converting host
names themselves when they pass them to the socket module.  On top of
that, modules that have host names as function parameters, such as *note
http.client: 73. and *note ftplib: 62, accept Unicode host names (*note
http.client: 73. then also transparently sends an IDNA hostname in the
‘Host’ field if it sends that field at all).

When receiving host names from the wire (such as in reverse name
lookup), no automatic conversion to Unicode is performed: applications
wishing to present such host names to the user should decode them to
Unicode.

The module *note encodings.idna: 56. also implements the nameprep
procedure, which performs certain normalizations on host names, to
achieve case-insensitivity of international domain names, and to unify
similar characters.  The nameprep functions can be used directly if
desired.

 -- Funzione: encodings.idna.nameprep (label)

     Return the nameprepped version of 'label'.  The implementation
     currently assumes query strings, so ‘AllowUnassigned’ is true.

 -- Funzione: encodings.idna.ToASCII (label)

     Convert a label to ASCII, as specified in RFC 3490(7).
     ‘UseSTD3ASCIIRules’ is assumed to be false.

 -- Funzione: encodings.idna.ToUnicode (label)

     Convert a label to Unicode, as specified in RFC 3490(8).

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc3490.html

   (2) https://datatracker.ietf.org/doc/html/rfc3492.html

   (3) https://datatracker.ietf.org/doc/html/rfc5891.html

   (4) https://datatracker.ietf.org/doc/html/rfc5895.html

   (5) https://pypi.org/project/idna/

   (6) https://datatracker.ietf.org/doc/html/rfc3490.html#section-3.1

   (7) https://datatracker.ietf.org/doc/html/rfc3490.html

   (8) https://datatracker.ietf.org/doc/html/rfc3490.html


File: python.info,  Node: encodings mbcs — Windows ANSI codepage,  Next: encodings utf_8_sig — UTF-8 codec with BOM signature,  Prev: encodings idna — Internationalized Domain Names in Applications,  Up: codecs — Codec registry and base classes

5.7.2.21 ‘encodings.mbcs’ — Windows ANSI codepage
.................................................

This module implements the ANSI codepage (CP_ACP).

*note Availability: 2128.: Windows.

Cambiato nella versione 3.2: Before 3.2, the 'errors' argument was
ignored; ‘'replace'’ was always used to encode, and ‘'ignore'’ to
decode.

Cambiato nella versione 3.3: Support any error handler.


File: python.info,  Node: encodings utf_8_sig — UTF-8 codec with BOM signature,  Prev: encodings mbcs — Windows ANSI codepage,  Up: codecs — Codec registry and base classes

5.7.2.22 ‘encodings.utf_8_sig’ — UTF-8 codec with BOM signature
...............................................................

This module implements a variant of the UTF-8 codec.  On encoding, a
UTF-8 encoded BOM will be prepended to the UTF-8 encoded bytes.  For the
stateful encoder this is only done once (on the first write to the byte
stream).  On decoding, an optional UTF-8 encoded BOM at the start of the
data will be skipped.


File: python.info,  Node: Data Types,  Next: Numeric and Mathematical Modules,  Prev: Binary Data Services,  Up: The Python Standard Library

5.8 Data Types
==============

The modules described in this chapter provide a variety of specialized
data types such as dates and times, fixed-type arrays, heap queues,
double-ended queues, and enumerations.

Python also provides some built-in data types, in particular, *note
dict: 183, *note list: 24d, *note set: 184. and *note frozenset: 7f3,
and *note tuple: 614.  The *note str: 169. class is used to hold Unicode
strings, and the *note bytes: 192. and *note bytearray: 344. classes are
used to hold binary data.

The following modules are documented in this chapter:

* Menu:

* datetime — Basic date and time types::
* zoneinfo — IANA time zone support::
* calendar — General calendar-related functions::
* collections — Container datatypes::
* collections.abc — Abstract Base Classes for Containers: collections abc — Abstract Base Classes for Containers.
* heapq — Heap queue algorithm::
* bisect — Array bisection algorithm::
* array — Efficient arrays of numeric values::
* weakref — Weak references::
* types — Dynamic type creation and names for built-in types::
* copy — Shallow and deep copy operations::
* pprint — Data pretty printer::
* reprlib — Alternate repr() implementation: reprlib — Alternate repr implementation.
* enum — Support for enumerations::
* graphlib — Functionality to operate with graph-like structures::


File: python.info,  Node: datetime — Basic date and time types,  Next: zoneinfo — IANA time zone support,  Up: Data Types

5.8.1 ‘datetime’ — Basic date and time types
--------------------------------------------

'Source code:' Lib/datetime.py(1)

__________________________________________________________________

The ‘datetime’ module supplies classes for manipulating dates and times.

While date and time arithmetic is supported, the focus of the
implementation is on efficient attribute extraction for output
formatting and manipulation.

     Suggerimento: Skip to *note the format codes: 287b.

Vedi anche
..........

Module *note calendar: 15.

     General calendar related functions.

Module *note time: f4.

     Time access and conversions.

Module *note zoneinfo: 13a.

     Concrete time zones representing the IANA time zone database.

Package dateutil(2)

     Third-party library with expanded time zone and parsing support.

Package DateType(3)

     Third-party library that introduces distinct static types to e.g.
     allow *note static type checkers: 574. to differentiate between
     naive and aware datetimes.

* Menu:

* Aware and Naive Objects::
* Constants::
* Available Types::
* timedelta Objects::
* date Objects::
* datetime Objects::
* time Objects::
* tzinfo Objects::
* timezone Objects::
* strftime() and strptime() Behavior: strftime and strptime Behavior.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/datetime.py

   (2) https://dateutil.readthedocs.io/en/stable/

   (3) https://pypi.org/project/DateType/


File: python.info,  Node: Aware and Naive Objects,  Next: Constants,  Up: datetime — Basic date and time types

5.8.1.1 Aware and Naive Objects
...............................

Date and time objects may be categorized as «aware» or «naive» depending
on whether or not they include time zone information.

With sufficient knowledge of applicable algorithmic and political time
adjustments, such as time zone and daylight saving time information, an
'aware' object can locate itself relative to other aware objects.  An
aware object represents a specific moment in time that is not open to
interpretation.  (1)

A 'naive' object does not contain enough information to unambiguously
locate itself relative to other date/time objects.  Whether a naive
object represents Coordinated Universal Time (UTC), local time, or time
in some other time zone is purely up to the program, just like it is up
to the program whether a particular number represents metres, miles, or
mass.  Naive objects are easy to understand and to work with, at the
cost of ignoring some aspects of reality.

For applications requiring aware objects, *note datetime: 4e3. and *note
time: 1fb. objects have an optional time zone information attribute,
‘tzinfo’, that can be set to an instance of a subclass of the abstract
*note tzinfo: 7f7. class.  These *note tzinfo: 7f7. objects capture
information about the offset from UTC time, the time zone name, and
whether daylight saving time is in effect.

Only one concrete *note tzinfo: 7f7. class, the *note timezone: 12c7.
class, is supplied by the ‘datetime’ module.  The ‘timezone’ class can
represent simple time zones with fixed offsets from UTC, such as UTC
itself or North American EST and EDT time zones.  Supporting time zones
at deeper levels of detail is up to the application.  The rules for time
adjustment across the world are more political than rational, change
frequently, and there is no standard suitable for every application
aside from UTC.

   ---------- Footnotes ----------

   (1) If, that is, we ignore the effects of Relativity


File: python.info,  Node: Constants,  Next: Available Types,  Prev: Aware and Naive Objects,  Up: datetime — Basic date and time types

5.8.1.2 Constants
.................

The ‘datetime’ module exports the following constants:

 -- Dati: datetime.MINYEAR

     The smallest year number allowed in a *note date: 1fa. or *note
     datetime: 4e3. object.  *note MINYEAR: 287f. is 1.

 -- Dati: datetime.MAXYEAR

     The largest year number allowed in a *note date: 1fa. or *note
     datetime: 4e3. object.  *note MAXYEAR: 2880. is 9999.

 -- Dati: datetime.UTC

     Alias for the UTC time zone singleton *note datetime.timezone.utc:
     828.

     Added in version 3.11.


File: python.info,  Node: Available Types,  Next: timedelta Objects,  Prev: Constants,  Up: datetime — Basic date and time types

5.8.1.3 Available Types
.......................

 -- Classe: datetime.date

     An idealized naive date, assuming the current Gregorian calendar
     always was, and always will be, in effect.  Attributes: *note year:
     2882, *note month: 2883, and *note day: 2884.

 -- Classe: datetime.time

     An idealized time, independent of any particular day, assuming that
     every day has exactly 24*60*60 seconds.  (There is no notion of
     «leap seconds» here.)  Attributes: *note hour: 2885, *note minute:
     2886, *note second: 2887, *note microsecond: 2888, and *note
     tzinfo: 2889.

 -- Classe: datetime.datetime

     A combination of a date and a time.  Attributes: *note year: 288a,
     *note month: 288b, *note day: 288c, *note hour: 288d, *note minute:
     288e, *note second: 288f, *note microsecond: 2890, and *note
     tzinfo: 2891.

 -- Classe: datetime.timedelta

     A duration expressing the difference between two *note datetime:
     4e3. or *note date: 1fa. instances to microsecond resolution.

 -- Classe: datetime.tzinfo

     An abstract base class for time zone information objects.  These
     are used by the *note datetime: 4e3. and *note time: 1fb. classes
     to provide a customizable notion of time adjustment (for example,
     to account for time zone and/or daylight saving time).

 -- Classe: datetime.timezone

     A class that implements the *note tzinfo: 7f7. abstract base class
     as a fixed offset from the UTC.

     Added in version 3.2.

Objects of these types are immutable.

Subclass relationships:

     object
         timedelta
         tzinfo
             timezone
         time
         date
             datetime

* Menu:

* Common Properties::
* Determining if an Object is Aware or Naive::


File: python.info,  Node: Common Properties,  Next: Determining if an Object is Aware or Naive,  Up: Available Types

5.8.1.4 Common Properties
.........................

The *note date: 1fa, *note datetime: 4e3, *note time: 1fb, and *note
timezone: 12c7. types share these common features:

   - Objects of these types are immutable.

   - Objects of these types are *note hashable: 825, meaning that they
     can be used as dictionary keys.

   - Objects of these types support efficient pickling via the *note
     pickle: ab. module.


File: python.info,  Node: Determining if an Object is Aware or Naive,  Prev: Common Properties,  Up: Available Types

5.8.1.5 Determining if an Object is Aware or Naive
..................................................

Objects of the *note date: 1fa. type are always naive.

An object of type *note time: 1fb. or *note datetime: 4e3. may be aware
or naive.

A *note datetime: 4e3. object ‘d’ is aware if both of the following
hold:

  1. ‘d.tzinfo’ is not ‘None’

  2. ‘d.tzinfo.utcoffset(d)’ does not return ‘None’

Otherwise, ‘d’ is naive.

A *note time: 1fb. object ‘t’ is aware if both of the following hold:

  1. ‘t.tzinfo’ is not ‘None’

  2. ‘t.tzinfo.utcoffset(None)’ does not return ‘None’.

Otherwise, ‘t’ is naive.

The distinction between aware and naive doesn’t apply to *note
timedelta: bc5. objects.


File: python.info,  Node: timedelta Objects,  Next: date Objects,  Prev: Available Types,  Up: datetime — Basic date and time types

5.8.1.6 ‘timedelta’ Objects
...........................

A *note timedelta: bc5. object represents a duration, the difference
between two *note datetime: 4e3. or *note date: 1fa. instances.

 -- Classe: datetime.timedelta (days=0, seconds=0, microseconds=0,
          milliseconds=0, minutes=0, hours=0, weeks=0)

     All arguments are optional and default to 0.  Arguments may be
     integers or floats, and may be positive or negative.

     Only 'days', 'seconds' and 'microseconds' are stored internally.
     Arguments are converted to those units:

        * A millisecond is converted to 1000 microseconds.

        * A minute is converted to 60 seconds.

        * An hour is converted to 3600 seconds.

        * A week is converted to 7 days.

     and days, seconds and microseconds are then normalized so that the
     representation is unique, with

        * ‘0 <= microseconds < 1000000’

        * ‘0 <= seconds < 3600*24’ (the number of seconds in one day)

        * ‘-999999999 <= days <= 999999999’

     The following example illustrates how any arguments besides 'days',
     'seconds' and 'microseconds' are «merged» and normalized into those
     three resulting attributes:

          >>> from datetime import timedelta
          >>> delta = timedelta(
          ...     days=50,
          ...     seconds=27,
          ...     microseconds=10,
          ...     milliseconds=29000,
          ...     minutes=5,
          ...     hours=8,
          ...     weeks=2
          ... )
          >>> # Only days, seconds, and microseconds remain
          >>> delta
          datetime.timedelta(days=64, seconds=29156, microseconds=10)

     If any argument is a float and there are fractional microseconds,
     the fractional microseconds left over from all arguments are
     combined and their sum is rounded to the nearest microsecond using
     round-half-to-even tiebreaker.  If no argument is a float, the
     conversion and normalization processes are exact (no information is
     lost).

     If the normalized value of days lies outside the indicated range,
     *note OverflowError: a83. is raised.

     Note that normalization of negative values may be surprising at
     first.  For example:

          >>> from datetime import timedelta
          >>> d = timedelta(microseconds=-1)
          >>> (d.days, d.seconds, d.microseconds)
          (-1, 86399, 999999)

     Since the string representation of ‘timedelta’ objects can be
     confusing, use the following recipe to produce a more readable
     format:

          >>> def pretty_timedelta(td):
          ...     if td.days >= 0:
          ...         return str(td)
          ...     return f'-({-td!s})'
          ...
          >>> d = timedelta(hours=-1)
          >>> str(d)  # not human-friendly
          '-1 day, 23:00:00'
          >>> pretty_timedelta(d)
          '-(1:00:00)'

Class attributes:

 -- Attributo: timedelta.min

     The most negative *note timedelta: bc5. object,
     ‘timedelta(-999999999)’.

 -- Attributo: timedelta.max

     The most positive *note timedelta: bc5. object,
     ‘timedelta(days=999999999, hours=23, minutes=59, seconds=59,
     microseconds=999999)’.

 -- Attributo: timedelta.resolution

     The smallest possible difference between non-equal *note timedelta:
     bc5. objects, ‘timedelta(microseconds=1)’.

Note that, because of normalization, ‘timedelta.max’ is greater than
‘-timedelta.min’.  ‘-timedelta.max’ is not representable as a *note
timedelta: bc5. object.

Instance attributes (read-only):

 -- Attributo: timedelta.days

     Between -999,999,999 and 999,999,999 inclusive.

 -- Attributo: timedelta.seconds

     Between 0 and 86,399 inclusive.

          Attenzione: It is a somewhat common bug for code to
          unintentionally use this attribute when it is actually
          intended to get a *note total_seconds(): 150d. value instead:

               >>> from datetime import timedelta
               >>> duration = timedelta(seconds=11235813)
               >>> duration.days, duration.seconds
               (130, 3813)
               >>> duration.total_seconds()
               11235813.0

 -- Attributo: timedelta.microseconds

     Between 0 and 999,999 inclusive.

Supported operations:

Operation                            Result
                                     
-----------------------------------------------------------------------------------------
                                     
‘t1 = t2 + t3’                       Sum of ‘t2’ and ‘t3’.  Afterwards ‘t1 - t2 == t3’
                                     and ‘t1 - t3 == t2’ are true.  (1)
                                     
                                     
‘t1 = t2 - t3’                       Difference of ‘t2’ and ‘t3’.  Afterwards ‘t1 ==
                                     t2 - t3’ and ‘t2 == t1 + t3’ are true.  (1)(6)
                                     
                                     
‘t1 = t2 * i or t1 = i * t2’         Delta multiplied by an integer.  Afterwards ‘t1
                                     // i == t2’ is true, provided ‘i != 0’.
                                     
                                     
                                     In general, ‘t1 * i == t1 * (i-1) + t1’ is true.
                                     (1)
                                     
                                     
‘t1 = t2 * f or t1 = f * t2’         Delta multiplied by a float.  The result is
                                     rounded to the nearest multiple of
                                     timedelta.resolution using round-half-to-even.
                                     
                                     
‘f = t2 / t3’                        Division (3) of overall duration ‘t2’ by interval
                                     unit ‘t3’.  Returns a *note float: 196. object.
                                     
                                     
‘t1 = t2 / f or t1 = t2 / i’         Delta divided by a float or an int.  The result
                                     is rounded to the nearest multiple of
                                     timedelta.resolution using round-half-to-even.
                                     
                                     
‘t1 = t2 // i’ or ‘t1 = t2 // t3’    The floor is computed and the remainder (if any)
                                     is thrown away.  In the second case, an integer
                                     is returned.  (3)
                                     
                                     
‘t1 = t2 % t3’                       The remainder is computed as a
                                     *note timedelta: bc5. object.  (3)
                                     
                                     
‘q, r = divmod(t1, t2)’              Computes the quotient and the remainder: ‘q = t1
                                     // t2’ (3) and ‘r = t1 % t2’.  ‘q’ is an integer
                                     and ‘r’ is a *note timedelta: bc5. object.
                                     
                                     
‘+t1’                                Returns a *note timedelta: bc5. object with the
                                     same value.  (2)
                                     
                                     
‘-t1’                                Equivalent to ‘timedelta(-t1.days, -t1.seconds,
                                     -t1.microseconds)’, and to ‘t1 * -1’.  (1)(4)
                                     
                                     
‘abs(t)’                             Equivalent to ‘+t’ when ‘t.days >= 0’, and to
                                     ‘-t’ when ‘t.days < 0’.  (2)
                                     
                                     
‘str(t)’                             Returns a string in the form ‘[D day[s],
                                     ][H]H:MM:SS[.UUUUUU]’, where D is negative for
                                     negative ‘t’.  (5)
                                     
                                     
‘repr(t)’                            Returns a string representation of the
                                     *note timedelta: bc5. object as a constructor
                                     call with canonical attribute values.
                                     

Notes:

  1. This is exact but may overflow.

  2. This is exact and cannot overflow.

  3. Division by zero raises *note ZeroDivisionError: b41.

  4. ‘-timedelta.max’ is not representable as a *note timedelta: bc5.
     object.

  5. String representations of *note timedelta: bc5. objects are
     normalized similarly to their internal representation.  This leads
     to somewhat unusual results for negative timedeltas.  For example:

          >>> timedelta(hours=-5)
          datetime.timedelta(days=-1, seconds=68400)
          >>> print(_)
          -1 day, 19:00:00

  6. The expression ‘t2 - t3’ will always be equal to the expression ‘t2
     + (-t3)’ except when t3 is equal to ‘timedelta.max’; in that case
     the former will produce a result while the latter will overflow.

In addition to the operations listed above, *note timedelta: bc5.
objects support certain additions and subtractions with *note date: 1fa.
and *note datetime: 4e3. objects (see below).

Cambiato nella versione 3.2: Floor division and true division of a *note
timedelta: bc5. object by another *note timedelta: bc5. object are now
supported, as are remainder operations and the *note divmod(): b9b.
function.  True division and multiplication of a *note timedelta: bc5.
object by a *note float: 196. object are now supported.

*note timedelta: bc5. objects support equality and order comparisons.

In Boolean contexts, a *note timedelta: bc5. object is considered to be
true if and only if it isn’t equal to ‘timedelta(0)’.

Instance methods:

 -- Metodo: timedelta.total_seconds ()

     Return the total number of seconds contained in the duration.
     Equivalent to ‘td / timedelta(seconds=1)’.  For interval units
     other than seconds, use the division form directly (e.g.  ‘td /
     timedelta(microseconds=1)’).

     Note that for very large time intervals (greater than 270 years on
     most platforms) this method will lose microsecond accuracy.

     Added in version 3.2.

* Menu:

* Examples of usage; timedelta: Examples of usage timedelta.


File: python.info,  Node: Examples of usage timedelta,  Up: timedelta Objects

5.8.1.7 Examples of usage: ‘timedelta’
......................................

An additional example of normalization:

     >>> # Components of another_year add up to exactly 365 days
     >>> from datetime import timedelta
     >>> year = timedelta(days=365)
     >>> another_year = timedelta(weeks=40, days=84, hours=23,
     ...                          minutes=50, seconds=600)
     >>> year == another_year
     True
     >>> year.total_seconds()
     31536000.0

Examples of *note timedelta: bc5. arithmetic:

     >>> from datetime import timedelta
     >>> year = timedelta(days=365)
     >>> ten_years = 10 * year
     >>> ten_years
     datetime.timedelta(days=3650)
     >>> ten_years.days // 365
     10
     >>> nine_years = ten_years - year
     >>> nine_years
     datetime.timedelta(days=3285)
     >>> three_years = nine_years // 3
     >>> three_years, three_years.days // 365
     (datetime.timedelta(days=1095), 3)


File: python.info,  Node: date Objects,  Next: datetime Objects,  Prev: timedelta Objects,  Up: datetime — Basic date and time types

5.8.1.8 ‘date’ Objects
......................

A *note date: 1fa. object represents a date (year, month and day) in an
idealized calendar, the current Gregorian calendar indefinitely extended
in both directions.

January 1 of year 1 is called day number 1, January 2 of year 1 is
called day number 2, and so on.  (1)

 -- Classe: datetime.date (year, month, day)

     All arguments are required.  Arguments must be integers, in the
     following ranges:

        * ‘MINYEAR <= year <= MAXYEAR’

        * ‘1 <= month <= 12’

        * ‘1 <= day <= number of days in the given month and year’

     If an argument outside those ranges is given, *note ValueError:
     2ec. is raised.

Other constructors, all class methods:

 -- Metodo: classmethod date.today ()

     Return the current local date.

     This is equivalent to ‘date.fromtimestamp(time.time())’.

 -- Metodo: classmethod date.fromtimestamp (timestamp)

     Return the local date corresponding to the POSIX timestamp, such as
     is returned by *note time.time(): 55d.

     This may raise *note OverflowError: a83, if the timestamp is out of
     the range of values supported by the platform C ‘localtime()’
     function, and *note OSError: 2c0. on ‘localtime()’ failure.  It’s
     common for this to be restricted to years from 1970 through 2038.
     Note that on non-POSIX systems that include leap seconds in their
     notion of a timestamp, leap seconds are ignored by *note
     fromtimestamp(): dcf.

     Cambiato nella versione 3.3: Raise *note OverflowError: a83.
     instead of *note ValueError: 2ec. if the timestamp is out of the
     range of values supported by the platform C ‘localtime()’ function.
     Raise *note OSError: 2c0. instead of *note ValueError: 2ec. on
     ‘localtime()’ failure.

 -- Metodo: classmethod date.fromordinal (ordinal)

     Return the date corresponding to the proleptic Gregorian ordinal,
     where January 1 of year 1 has ordinal 1.

     *note ValueError: 2ec. is raised unless ‘1 <= ordinal <=
     date.max.toordinal()’.  For any date ‘d’,
     ‘date.fromordinal(d.toordinal()) == d’.

 -- Metodo: classmethod date.fromisoformat (date_string)

     Return a *note date: 1fa. corresponding to a 'date_string' given in
     any valid ISO 8601 format, with the following exceptions:

       1. Reduced precision dates are not currently supported
          (‘YYYY-MM’, ‘YYYY’).

       2. Extended date representations are not currently supported
          (‘±YYYYYY-MM-DD’).

       3. Ordinal dates are not currently supported (‘YYYY-OOO’).

     Examples:

          >>> from datetime import date
          >>> date.fromisoformat('2019-12-04')
          datetime.date(2019, 12, 4)
          >>> date.fromisoformat('20191204')
          datetime.date(2019, 12, 4)
          >>> date.fromisoformat('2021-W01-1')
          datetime.date(2021, 1, 4)

     Added in version 3.7.

     Cambiato nella versione 3.11: Previously, this method only
     supported the format ‘YYYY-MM-DD’.

 -- Metodo: classmethod date.fromisocalendar (year, week, day)

     Return a *note date: 1fa. corresponding to the ISO calendar date
     specified by year, week and day.  This is the inverse of the
     function *note date.isocalendar(): af3.

     Added in version 3.8.

 -- Metodo: classmethod date.strptime (date_string, format)

     Return a *note date: 1fa. corresponding to 'date_string', parsed
     according to 'format'.  This is equivalent to:

          date(*(time.strptime(date_string, format)[0:3]))

     *note ValueError: 2ec. is raised if the date_string and format
     can’t be parsed by *note time.strptime(): 1634. or if it returns a
     value which isn’t a time tuple.  See also *note strftime() and
     strptime() Behavior: 1b3c. and *note date.fromisoformat(): 829.

          Nota: If 'format' specifies a day of month without a year a
          *note DeprecationWarning: 1a3. is emitted.  This is to avoid a
          quadrennial leap year bug in code seeking to parse only a
          month and day as the default year used in absence of one in
          the format is not a leap year.  Such 'format' values may raise
          an error as of Python 3.15.  The workaround is to always
          include a year in your 'format'.  If parsing 'date_string'
          values that do not have a year, explicitly add a year that is
          a leap year before parsing:

               >>> from datetime import date
               >>> date_string = "02/29"
               >>> when = date.strptime(f"{date_string};1984", "%m/%d;%Y")  # Avoids leap year bug.
               >>> when.strftime("%B %d")
               'February 29'

     Added in version 3.14.

Class attributes:

 -- Attributo: date.min

     The earliest representable date, ‘date(MINYEAR, 1, 1)’.

 -- Attributo: date.max

     The latest representable date, ‘date(MAXYEAR, 12, 31)’.

 -- Attributo: date.resolution

     The smallest possible difference between non-equal date objects,
     ‘timedelta(days=1)’.

Instance attributes (read-only):

 -- Attributo: date.year

     Between *note MINYEAR: 287f. and *note MAXYEAR: 2880. inclusive.

 -- Attributo: date.month

     Between 1 and 12 inclusive.

 -- Attributo: date.day

     Between 1 and the number of days in the given month of the given
     year.

Supported operations:

Operation                           Result
                                    
---------------------------------------------------------------------------------------
                                    
‘date2 = date1 + timedelta’         ‘date2’ will be ‘timedelta.days’ days after
                                    ‘date1’.  (1)
                                    
                                    
‘date2 = date1 - timedelta’         Computes ‘date2’ such that ‘date2 + timedelta ==
                                    date1’.  (2)
                                    
                                    
‘timedelta = date1 - date2’         (3)
                                    
                                    
     ‘date1 == date2’               Equality comparison.  (4)
     ‘date1 != date2’               

     ‘date1 < date2’                Order comparison.  (5)
     ‘date1 > date2’                
     ‘date1 <= date2’
     ‘date1 >= date2’

Notes:

  1. 'date2' is moved forward in time if ‘timedelta.days > 0’, or
     backward if ‘timedelta.days < 0’.  Afterward ‘date2 - date1 ==
     timedelta.days’.  ‘timedelta.seconds’ and ‘timedelta.microseconds’
     are ignored.  *note OverflowError: a83. is raised if ‘date2.year’
     would be smaller than *note MINYEAR: 287f. or larger than *note
     MAXYEAR: 2880.

  2. ‘timedelta.seconds’ and ‘timedelta.microseconds’ are ignored.

  3. This is exact, and cannot overflow.  ‘timedelta.seconds’ and
     ‘timedelta.microseconds’ are 0, and ‘date2 + timedelta == date1’
     after.

  4. *note date: 1fa. objects are equal if they represent the same date.

     ‘date’ objects that are not also *note datetime: 4e3. instances are
     never equal to ‘datetime’ objects, even if they represent the same
     date.

  5. 'date1' is considered less than 'date2' when 'date1' precedes
     'date2' in time.  In other words, ‘date1 < date2’ if and only if
     ‘date1.toordinal() < date2.toordinal()’.

     Order comparison between a ‘date’ object that is not also a *note
     datetime: 4e3. instance and a ‘datetime’ object raises *note
     TypeError: 198.

Cambiato nella versione 3.13: Comparison between *note datetime: 4e3.
object and an instance of the *note date: 1fa. subclass that is not a
‘datetime’ subclass no longer converts the latter to ‘date’, ignoring
the time part and the time zone.  The default behavior can be changed by
overriding the special comparison methods in subclasses.

In Boolean contexts, all *note date: 1fa. objects are considered to be
true.

Instance methods:

 -- Metodo: date.replace (year=self.year, month=self.month,
          day=self.day)

     Return a new *note date: 1fa. object with the same values, but with
     specified parameters updated.

     Example:

          >>> from datetime import date
          >>> d = date(2002, 12, 31)
          >>> d.replace(day=26)
          datetime.date(2002, 12, 26)

     The generic function *note copy.replace(): 1c0. also supports *note
     date: 1fa. objects.

 -- Metodo: date.timetuple ()

     Return a *note time.struct_time: ee8. such as returned by *note
     time.localtime(): 1700.

     The hours, minutes and seconds are 0, and the DST flag is -1.

     ‘d.timetuple()’ is equivalent to:

          time.struct_time((d.year, d.month, d.day, 0, 0, 0, d.weekday(), yday, -1))

     where ‘yday = d.toordinal() - date(d.year, 1, 1).toordinal() + 1’
     is the day number within the current year starting with 1 for
     January 1st.

 -- Metodo: date.toordinal ()

     Return the proleptic Gregorian ordinal of the date, where January 1
     of year 1 has ordinal 1.  For any *note date: 1fa. object ‘d’,
     ‘date.fromordinal(d.toordinal()) == d’.

 -- Metodo: date.weekday ()

     Return the day of the week as an integer, where Monday is 0 and
     Sunday is 6.  For example, ‘date(2002, 12, 4).weekday() == 2’, a
     Wednesday.  See also *note isoweekday(): 28a5.

 -- Metodo: date.isoweekday ()

     Return the day of the week as an integer, where Monday is 1 and
     Sunday is 7.  For example, ‘date(2002, 12, 4).isoweekday() == 3’, a
     Wednesday.  See also *note weekday(): 28a4, *note isocalendar():
     af3.

 -- Metodo: date.isocalendar ()

     Return a *note named tuple: 85f. object with three components:
     ‘year’, ‘week’ and ‘weekday’.

     The ISO calendar is a widely used variant of the Gregorian
     calendar.  (2)

     The ISO year consists of 52 or 53 full weeks, and where a week
     starts on a Monday and ends on a Sunday.  The first week of an ISO
     year is the first (Gregorian) calendar week of a year containing a
     Thursday.  This is called week number 1, and the ISO year of that
     Thursday is the same as its Gregorian year.

     For example, 2004 begins on a Thursday, so the first week of ISO
     year 2004 begins on Monday, 29 Dec 2003 and ends on Sunday, 4 Jan
     2004:

          >>> from datetime import date
          >>> date(2003, 12, 29).isocalendar()
          datetime.IsoCalendarDate(year=2004, week=1, weekday=1)
          >>> date(2004, 1, 4).isocalendar()
          datetime.IsoCalendarDate(year=2004, week=1, weekday=7)

     Cambiato nella versione 3.9: Result changed from a tuple to a *note
     named tuple: 85f.

 -- Metodo: date.isoformat ()

     Return a string representing the date in ISO 8601 format,
     ‘YYYY-MM-DD’:

          >>> from datetime import date
          >>> date(2002, 12, 4).isoformat()
          '2002-12-04'

 -- Metodo: date.__str__ ()

     For a date ‘d’, ‘str(d)’ is equivalent to ‘d.isoformat()’.

 -- Metodo: date.ctime ()

     Return a string representing the date:

          >>> from datetime import date
          >>> date(2002, 12, 4).ctime()
          'Wed Dec  4 00:00:00 2002'

     ‘d.ctime()’ is equivalent to:

          time.ctime(time.mktime(d.timetuple()))

     on platforms where the native C ‘ctime()’ function (which *note
     time.ctime(): 28a9. invokes, but which *note date.ctime(): 28a8.
     does not invoke) conforms to the C standard.

 -- Metodo: date.strftime (format)

     Return a string representing the date, controlled by an explicit
     format string.  Format codes referring to hours, minutes or seconds
     will see 0 values.  See also *note strftime() and strptime()
     Behavior: 1b3c. and *note date.isoformat(): 28a6.

 -- Metodo: date.__format__ (format)

     Same as *note date.strftime(): e91.  This makes it possible to
     specify a format string for a *note date: 1fa. object in *note
     formatted string literals: 19a. and when using *note str.format():
     834.  See also *note strftime() and strptime() Behavior: 1b3c. and
     *note date.isoformat(): 28a6.

* Menu:

* Examples of Usage; date: Examples of Usage date.

   ---------- Footnotes ----------

   (1) This matches the definition of the «proleptic Gregorian» calendar
in Dershowitz and Reingold’s book 'Calendrical Calculations', where it’s
the base calendar for all computations.  See the book for algorithms for
converting between proleptic Gregorian ordinals and many other calendar
systems.

   (2) See R. H. van Gent’s guide to the mathematics of the ISO 8601
calendar
(https://web.archive.org/web/20220531051136/https://webspace.science.uu.nl/~gent0113/calendar/isocalendar.htm)
for a good explanation.


File: python.info,  Node: Examples of Usage date,  Up: date Objects

5.8.1.9 Examples of Usage: ‘date’
.................................

Example of counting days to an event:

     >>> import time
     >>> from datetime import date
     >>> today = date.today()
     >>> today
     datetime.date(2007, 12, 5)
     >>> today == date.fromtimestamp(time.time())
     True
     >>> my_birthday = date(today.year, 6, 24)
     >>> if my_birthday < today:
     ...     my_birthday = my_birthday.replace(year=today.year + 1)
     ...
     >>> my_birthday
     datetime.date(2008, 6, 24)
     >>> time_to_birthday = abs(my_birthday - today)
     >>> time_to_birthday.days
     202

More examples of working with *note date: 1fa.:

     >>> from datetime import date
     >>> d = date.fromordinal(730920) # 730920th day after 1. 1. 0001
     >>> d
     datetime.date(2002, 3, 11)

     >>> # Methods related to formatting string output
     >>> d.isoformat()
     '2002-03-11'
     >>> d.strftime("%d/%m/%y")
     '11/03/02'
     >>> d.strftime("%A %d. %B %Y")
     'Monday 11. March 2002'
     >>> d.ctime()
     'Mon Mar 11 00:00:00 2002'
     >>> 'The {1} is {0:%d}, the {2} is {0:%B}.'.format(d, "day", "month")
     'The day is 11, the month is March.'

     >>> # Methods for to extracting 'components' under different calendars
     >>> t = d.timetuple()
     >>> for i in t:
     ...     print(i)
     2002                # year
     3                   # month
     11                  # day
     0
     0
     0
     0                   # weekday (0 = Monday)
     70                  # 70th day in the year
     -1
     >>> ic = d.isocalendar()
     >>> for i in ic:
     ...     print(i)
     2002                # ISO year
     11                  # ISO week number
     1                   # ISO day number ( 1 = Monday )

     >>> # A date object is immutable; all operations produce a new object
     >>> d.replace(year=2005)
     datetime.date(2005, 3, 11)


File: python.info,  Node: datetime Objects,  Next: time Objects,  Prev: date Objects,  Up: datetime — Basic date and time types

5.8.1.10 ‘datetime’ Objects
...........................

A *note datetime: 4e3. object is a single object containing all the
information from a *note date: 1fa. object and a *note time: 1fb.
object.

Like a *note date: 1fa. object, *note datetime: 4e3. assumes the current
Gregorian calendar extended in both directions; like a *note time: 1fb.
object, *note datetime: 4e3. assumes there are exactly 3600*24 seconds
in every day.

Constructor:

 -- Classe: datetime.datetime (year, month, day, hour=0, minute=0,
          second=0, microsecond=0, tzinfo=None, *, fold=0)

     The 'year', 'month' and 'day' arguments are required.  'tzinfo' may
     be ‘None’, or an instance of a *note tzinfo: 7f7. subclass.  The
     remaining arguments must be integers in the following ranges:

        * ‘MINYEAR <= year <= MAXYEAR’,

        * ‘1 <= month <= 12’,

        * ‘1 <= day <= number of days in the given month and year’,

        * ‘0 <= hour < 24’,

        * ‘0 <= minute < 60’,

        * ‘0 <= second < 60’,

        * ‘0 <= microsecond < 1000000’,

        * ‘fold in [0, 1]’.

     If an argument outside those ranges is given, *note ValueError:
     2ec. is raised.

     Cambiato nella versione 3.6: Added the 'fold' parameter.

Other constructors, all class methods:

 -- Metodo: classmethod datetime.today ()

     Return the current local date and time, with *note tzinfo: 2891.
     ‘None’.

     Equivalent to:

          datetime.fromtimestamp(time.time())

     See also *note now(): 712, *note fromtimestamp(): 713.

     This method is functionally equivalent to *note now(): 712, but
     without a ‘tz’ parameter.

 -- Metodo: classmethod datetime.now (tz=None)

     Return the current local date and time.

     If optional argument 'tz' is ‘None’ or not specified, this is like
     *note today(): 28ae, but, if possible, supplies more precision than
     can be gotten from going through a *note time.time(): 55d.
     timestamp (for example, this may be possible on platforms supplying
     the C ‘gettimeofday()’ function).

     If 'tz' is not ‘None’, it must be an instance of a *note tzinfo:
     7f7. subclass, and the current date and time are converted to
     'tz'’s time zone.

     This function is preferred over *note today(): 28ae. and *note
     utcnow(): 351.

          Nota: Subsequent calls to ‘datetime.now()’ may return the same
          instant depending on the precision of the underlying clock.

 -- Metodo: classmethod datetime.utcnow ()

     Return the current UTC date and time, with *note tzinfo: 2891.
     ‘None’.

     This is like *note now(): 712, but returns the current UTC date and
     time, as a naive *note datetime: 4e3. object.  An aware current UTC
     datetime can be obtained by calling ‘datetime.now(timezone.utc)’.
     See also *note now(): 712.

          Avvertimento: Because naive ‘datetime’ objects are treated by
          many ‘datetime’ methods as local times, it is preferred to use
          aware datetimes to represent times in UTC. As such, the
          recommended way to create an object representing the current
          time in UTC is by calling ‘datetime.now(timezone.utc)’.

     Deprecato dalla versione 3.12: Use *note datetime.now(): 712. with
     *note UTC: 714. instead.

 -- Metodo: classmethod datetime.fromtimestamp (timestamp, tz=None)

     Return the local date and time corresponding to the POSIX
     timestamp, such as is returned by *note time.time(): 55d.  If
     optional argument 'tz' is ‘None’ or not specified, the timestamp is
     converted to the platform’s local date and time, and the returned
     *note datetime: 4e3. object is naive.

     If 'tz' is not ‘None’, it must be an instance of a *note tzinfo:
     7f7. subclass, and the timestamp is converted to 'tz'’s time zone.

     *note fromtimestamp(): 713. may raise *note OverflowError: a83, if
     the timestamp is out of the range of values supported by the
     platform C ‘localtime()’ or ‘gmtime()’ functions, and *note
     OSError: 2c0. on ‘localtime()’ or ‘gmtime()’ failure.  It’s common
     for this to be restricted to years in 1970 through 2038.  Note that
     on non-POSIX systems that include leap seconds in their notion of a
     timestamp, leap seconds are ignored by *note fromtimestamp(): 713,
     and then it’s possible to have two timestamps differing by a second
     that yield identical *note datetime: 4e3. objects.  This method is
     preferred over *note utcfromtimestamp(): 352.

     Cambiato nella versione 3.3: Raise *note OverflowError: a83.
     instead of *note ValueError: 2ec. if the timestamp is out of the
     range of values supported by the platform C ‘localtime()’ or
     ‘gmtime()’ functions.  Raise *note OSError: 2c0. instead of *note
     ValueError: 2ec. on ‘localtime()’ or ‘gmtime()’ failure.

     Cambiato nella versione 3.6: *note fromtimestamp(): 713. may return
     instances with *note fold: e53. set to 1.

 -- Metodo: classmethod datetime.utcfromtimestamp (timestamp)

     Return the UTC *note datetime: 4e3. corresponding to the POSIX
     timestamp, with *note tzinfo: 2891. ‘None’.  (The resulting object
     is naive.)

     This may raise *note OverflowError: a83, if the timestamp is out of
     the range of values supported by the platform C ‘gmtime()’
     function, and *note OSError: 2c0. on ‘gmtime()’ failure.  It’s
     common for this to be restricted to years in 1970 through 2038.

     To get an aware *note datetime: 4e3. object, call *note
     fromtimestamp(): 713.:

          datetime.fromtimestamp(timestamp, timezone.utc)

     On the POSIX compliant platforms, it is equivalent to the following
     expression:

          datetime(1970, 1, 1, tzinfo=timezone.utc) + timedelta(seconds=timestamp)

     except the latter formula always supports the full years range:
     between *note MINYEAR: 287f. and *note MAXYEAR: 2880. inclusive.

          Avvertimento: Because naive ‘datetime’ objects are treated by
          many ‘datetime’ methods as local times, it is preferred to use
          aware datetimes to represent times in UTC. As such, the
          recommended way to create an object representing a specific
          timestamp in UTC is by calling
          ‘datetime.fromtimestamp(timestamp, tz=timezone.utc)’.

     Cambiato nella versione 3.3: Raise *note OverflowError: a83.
     instead of *note ValueError: 2ec. if the timestamp is out of the
     range of values supported by the platform C ‘gmtime()’ function.
     Raise *note OSError: 2c0. instead of *note ValueError: 2ec. on
     ‘gmtime()’ failure.

     Deprecato dalla versione 3.12: Use *note datetime.fromtimestamp():
     713. with *note UTC: 714. instead.

 -- Metodo: classmethod datetime.fromordinal (ordinal)

     Return the *note datetime: 4e3. corresponding to the proleptic
     Gregorian ordinal, where January 1 of year 1 has ordinal 1.  *note
     ValueError: 2ec. is raised unless ‘1 <= ordinal <=
     datetime.max.toordinal()’.  The hour, minute, second and
     microsecond of the result are all 0, and *note tzinfo: 2891. is
     ‘None’.

 -- Metodo: classmethod datetime.combine (date, time,
          tzinfo=time.tzinfo)

     Return a new *note datetime: 4e3. object whose date components are
     equal to the given *note date: 1fa. object’s, and whose time
     components are equal to the given *note time: 1fb. object’s.  If
     the 'tzinfo' argument is provided, its value is used to set the
     *note tzinfo: 2891. attribute of the result, otherwise the *note
     tzinfo: 2889. attribute of the 'time' argument is used.  If the
     'date' argument is a *note datetime: 4e3. object, its time
     components and *note tzinfo: 2891. attributes are ignored.

     For any *note datetime: 4e3. object ‘d’, ‘d ==
     datetime.combine(d.date(), d.time(), d.tzinfo)’.

     Cambiato nella versione 3.6: Added the 'tzinfo' argument.

 -- Metodo: classmethod datetime.fromisoformat (date_string)

     Return a *note datetime: 4e3. corresponding to a 'date_string' in
     any valid ISO 8601 format, with the following exceptions:

       1. Time zone offsets may have fractional seconds.

       2. The ‘T’ separator may be replaced by any single unicode
          character.

       3. Fractional hours and minutes are not supported.

       4. Reduced precision dates are not currently supported
          (‘YYYY-MM’, ‘YYYY’).

       5. Extended date representations are not currently supported
          (‘±YYYYYY-MM-DD’).

       6. Ordinal dates are not currently supported (‘YYYY-OOO’).

     Examples:

          >>> from datetime import datetime
          >>> datetime.fromisoformat('2011-11-04')
          datetime.datetime(2011, 11, 4, 0, 0)
          >>> datetime.fromisoformat('20111104')
          datetime.datetime(2011, 11, 4, 0, 0)
          >>> datetime.fromisoformat('2011-11-04T00:05:23')
          datetime.datetime(2011, 11, 4, 0, 5, 23)
          >>> datetime.fromisoformat('2011-11-04T00:05:23Z')
          datetime.datetime(2011, 11, 4, 0, 5, 23, tzinfo=datetime.timezone.utc)
          >>> datetime.fromisoformat('20111104T000523')
          datetime.datetime(2011, 11, 4, 0, 5, 23)
          >>> datetime.fromisoformat('2011-W01-2T00:05:23.283')
          datetime.datetime(2011, 1, 4, 0, 5, 23, 283000)
          >>> datetime.fromisoformat('2011-11-04 00:05:23.283')
          datetime.datetime(2011, 11, 4, 0, 5, 23, 283000)
          >>> datetime.fromisoformat('2011-11-04 00:05:23.283+00:00')
          datetime.datetime(2011, 11, 4, 0, 5, 23, 283000, tzinfo=datetime.timezone.utc)
          >>> datetime.fromisoformat('2011-11-04T00:05:23+04:00')
          datetime.datetime(2011, 11, 4, 0, 5, 23,
              tzinfo=datetime.timezone(datetime.timedelta(seconds=14400)))

     Added in version 3.7.

     Cambiato nella versione 3.11: Previously, this method only
     supported formats that could be emitted by *note date.isoformat():
     28a6. or *note datetime.isoformat(): d27.

 -- Metodo: classmethod datetime.fromisocalendar (year, week, day)

     Return a *note datetime: 4e3. corresponding to the ISO calendar
     date specified by year, week and day.  The non-date components of
     the datetime are populated with their normal default values.  This
     is the inverse of the function *note datetime.isocalendar(): af4.

     Added in version 3.8.

 -- Metodo: classmethod datetime.strptime (date_string, format)

     Return a *note datetime: 4e3. corresponding to 'date_string',
     parsed according to 'format'.

     If 'format' does not contain microseconds or time zone information,
     this is equivalent to:

          datetime(*(time.strptime(date_string, format)[0:6]))

     *note ValueError: 2ec. is raised if the date_string and format
     can’t be parsed by *note time.strptime(): 1634. or if it returns a
     value which isn’t a time tuple.  See also *note strftime() and
     strptime() Behavior: 1b3c. and *note datetime.fromisoformat(): 82b.

     Cambiato nella versione 3.13: If 'format' specifies a day of month
     without a year a *note DeprecationWarning: 1a3. is now emitted.
     This is to avoid a quadrennial leap year bug in code seeking to
     parse only a month and day as the default year used in absence of
     one in the format is not a leap year.  Such 'format' values may
     raise an error as of Python 3.15.  The workaround is to always
     include a year in your 'format'.  If parsing 'date_string' values
     that do not have a year, explicitly add a year that is a leap year
     before parsing:

          >>> from datetime import datetime
          >>> date_string = "02/29"
          >>> when = datetime.strptime(f"{date_string};1984", "%m/%d;%Y")  # Avoids leap year bug.
          >>> when.strftime("%B %d")
          'February 29'

Class attributes:

 -- Attributo: datetime.min

     The earliest representable *note datetime: 4e3, ‘datetime(MINYEAR,
     1, 1, tzinfo=None)’.

 -- Attributo: datetime.max

     The latest representable *note datetime: 4e3, ‘datetime(MAXYEAR,
     12, 31, 23, 59, 59, 999999, tzinfo=None)’.

 -- Attributo: datetime.resolution

     The smallest possible difference between non-equal *note datetime:
     4e3. objects, ‘timedelta(microseconds=1)’.

Instance attributes (read-only):

 -- Attributo: datetime.year

     Between *note MINYEAR: 287f. and *note MAXYEAR: 2880. inclusive.

 -- Attributo: datetime.month

     Between 1 and 12 inclusive.

 -- Attributo: datetime.day

     Between 1 and the number of days in the given month of the given
     year.

 -- Attributo: datetime.hour

     In ‘range(24)’.

 -- Attributo: datetime.minute

     In ‘range(60)’.

 -- Attributo: datetime.second

     In ‘range(60)’.

 -- Attributo: datetime.microsecond

     In ‘range(1000000)’.

 -- Attributo: datetime.tzinfo

     The object passed as the 'tzinfo' argument to the *note datetime:
     4e3. constructor, or ‘None’ if none was passed.

 -- Attributo: datetime.fold

     In ‘[0, 1]’.  Used to disambiguate wall times during a repeated
     interval.  (A repeated interval occurs when clocks are rolled back
     at the end of daylight saving time or when the UTC offset for the
     current zone is decreased for political reasons.)  The values 0 and
     1 represent, respectively, the earlier and later of the two moments
     with the same wall time representation.

     Added in version 3.6.

Supported operations:

Operation                                   Result
                                            
---------------------------------------------------------------------------------
                                            
‘datetime2 = datetime1 + timedelta’         (1)
                                            
                                            
‘datetime2 = datetime1 - timedelta’         (2)
                                            
                                            
‘timedelta = datetime1 - datetime2’         (3)
                                            
                                            
     ‘datetime1 == datetime2’               Equality comparison.  (4)
     ‘datetime1 != datetime2’               

     ‘datetime1 < datetime2’                Order comparison.  (5)
     ‘datetime1 > datetime2’                
     ‘datetime1 <= datetime2’
     ‘datetime1 >= datetime2’

  1. ‘datetime2’ is a duration of ‘timedelta’ removed from ‘datetime1’,
     moving forward in time if ‘timedelta.days > 0’, or backward if
     ‘timedelta.days < 0’.  The result has the same *note tzinfo: 2891.
     attribute as the input datetime, and ‘datetime2 - datetime1 ==
     timedelta’ after.  *note OverflowError: a83. is raised if
     ‘datetime2.year’ would be smaller than *note MINYEAR: 287f. or
     larger than *note MAXYEAR: 2880.  Note that no time zone
     adjustments are done even if the input is an aware object.

  2. Computes the ‘datetime2’ such that ‘datetime2 + timedelta ==
     datetime1’.  As for addition, the result has the same *note tzinfo:
     2891. attribute as the input datetime, and no time zone adjustments
     are done even if the input is aware.

  3. Subtraction of a *note datetime: 4e3. from a *note datetime: 4e3.
     is defined only if both operands are naive, or if both are aware.
     If one is aware and the other is naive, *note TypeError: 198. is
     raised.

     If both are naive, or both are aware and have the same *note
     tzinfo: 2891. attribute, the *note tzinfo: 2891. attributes are
     ignored, and the result is a *note timedelta: bc5. object ‘t’ such
     that ‘datetime2 + t == datetime1’.  No time zone adjustments are
     done in this case.

     If both are aware and have different *note tzinfo: 2891.
     attributes, ‘a-b’ acts as if ‘a’ and ‘b’ were first converted to
     naive UTC datetimes.  The result is ‘(a.replace(tzinfo=None) -
     a.utcoffset()) - (b.replace(tzinfo=None) - b.utcoffset())’ except
     that the implementation never overflows.

  4. *note datetime: 4e3. objects are equal if they represent the same
     date and time, taking into account the time zone.

     Naive and aware ‘datetime’ objects are never equal.

     If both comparands are aware, and have the same ‘tzinfo’ attribute,
     the ‘tzinfo’ and *note fold: e53. attributes are ignored and the
     base datetimes are compared.  If both comparands are aware and have
     different *note tzinfo: 2891. attributes, the comparison acts as
     comparands were first converted to UTC datetimes except that the
     implementation never overflows.  ‘datetime’ instances in a repeated
     interval are never equal to ‘datetime’ instances in other time
     zone.

  5. 'datetime1' is considered less than 'datetime2' when 'datetime1'
     precedes 'datetime2' in time, taking into account the time zone.

     Order comparison between naive and aware *note datetime: 4e3.
     objects raises *note TypeError: 198.

     If both comparands are aware, and have the same ‘tzinfo’ attribute,
     the ‘tzinfo’ and *note fold: e53. attributes are ignored and the
     base datetimes are compared.  If both comparands are aware and have
     different *note tzinfo: 2891. attributes, the comparison acts as
     comparands were first converted to UTC datetimes except that the
     implementation never overflows.

Cambiato nella versione 3.3: Equality comparisons between aware and
naive *note datetime: 4e3. instances don’t raise *note TypeError: 198.

Cambiato nella versione 3.13: Comparison between *note datetime: 4e3.
object and an instance of the *note date: 1fa. subclass that is not a
‘datetime’ subclass no longer converts the latter to ‘date’, ignoring
the time part and the time zone.  The default behavior can be changed by
overriding the special comparison methods in subclasses.

Instance methods:

 -- Metodo: datetime.date ()

     Return *note date: 1fa. object with same year, month and day.

 -- Metodo: datetime.time ()

     Return *note time: 1fb. object with same hour, minute, second,
     microsecond and fold.  *note tzinfo: 2891. is ‘None’.  See also
     method *note timetz(): 28b4.

     Cambiato nella versione 3.6: The fold value is copied to the
     returned *note time: 1fb. object.

 -- Metodo: datetime.timetz ()

     Return *note time: 1fb. object with same hour, minute, second,
     microsecond, fold, and tzinfo attributes.  See also method *note
     time(): f4.

     Cambiato nella versione 3.6: The fold value is copied to the
     returned *note time: 1fb. object.

 -- Metodo: datetime.replace (year=self.year, month=self.month,
          day=self.day, hour=self.hour, minute=self.minute,
          second=self.second, microsecond=self.microsecond,
          tzinfo=self.tzinfo, *, fold=0)

     Return a new *note datetime: 34. object with the same attributes,
     but with specified parameters updated.  Note that ‘tzinfo=None’ can
     be specified to create a naive datetime from an aware datetime with
     no conversion of date and time data.

     *note datetime: 4e3. objects are also supported by generic function
     *note copy.replace(): 1c0.

     Cambiato nella versione 3.6: Added the 'fold' parameter.

 -- Metodo: datetime.astimezone (tz=None)

     Return a *note datetime: 4e3. object with new *note tzinfo: 2891.
     attribute 'tz', adjusting the date and time data so the result is
     the same UTC time as 'self', but in 'tz'’s local time.

     If provided, 'tz' must be an instance of a *note tzinfo: 7f7.
     subclass, and its *note utcoffset(): 28b5. and *note dst(): 28b6.
     methods must not return ‘None’.  If 'self' is naive, it is presumed
     to represent time in the system time zone.

     If called without arguments (or with ‘tz=None’) the system local
     time zone is assumed for the target time zone.  The ‘.tzinfo’
     attribute of the converted datetime instance will be set to an
     instance of *note timezone: 12c7. with the zone name and offset
     obtained from the OS.

     If ‘self.tzinfo’ is 'tz', ‘self.astimezone(tz)’ is equal to 'self':
     no adjustment of date or time data is performed.  Else the result
     is local time in the time zone 'tz', representing the same UTC time
     as 'self': after ‘astz = dt.astimezone(tz)’, ‘astz -
     astz.utcoffset()’ will have the same date and time data as ‘dt -
     dt.utcoffset()’.

     If you merely want to attach a *note timezone: 12c7. object 'tz' to
     a datetime 'dt' without adjustment of date and time data, use
     ‘dt.replace(tzinfo=tz)’.  If you merely want to remove the
     ‘timezone’ object from an aware datetime 'dt' without conversion of
     date and time data, use ‘dt.replace(tzinfo=None)’.

     Note that the default *note tzinfo.fromutc(): 28b7. method can be
     overridden in a *note tzinfo: 7f7. subclass to affect the result
     returned by *note astimezone(): bc6.  Ignoring error cases, *note
     astimezone(): bc6. acts like:

          def astimezone(self, tz):
              if self.tzinfo is tz:
                  return self
              # Convert self to UTC, and attach the new timezone object.
              utc = (self - self.utcoffset()).replace(tzinfo=tz)
              # Convert from UTC to tz's local time.
              return tz.fromutc(utc)

     Cambiato nella versione 3.3: 'tz' now can be omitted.

     Cambiato nella versione 3.6: The *note astimezone(): bc6. method
     can now be called on naive instances that are presumed to represent
     system local time.

 -- Metodo: datetime.utcoffset ()

     If *note tzinfo: 2891. is ‘None’, returns ‘None’, else returns
     ‘self.tzinfo.utcoffset(self)’, and raises an exception if the
     latter doesn’t return ‘None’ or a *note timedelta: bc5. object with
     magnitude less than one day.

     Cambiato nella versione 3.7: The UTC offset is not restricted to a
     whole number of minutes.

 -- Metodo: datetime.dst ()

     If *note tzinfo: 2891. is ‘None’, returns ‘None’, else returns
     ‘self.tzinfo.dst(self)’, and raises an exception if the latter
     doesn’t return ‘None’ or a *note timedelta: bc5. object with
     magnitude less than one day.

     Cambiato nella versione 3.7: The DST offset is not restricted to a
     whole number of minutes.

 -- Metodo: datetime.tzname ()

     If *note tzinfo: 2891. is ‘None’, returns ‘None’, else returns
     ‘self.tzinfo.tzname(self)’, raises an exception if the latter
     doesn’t return ‘None’ or a string object,

 -- Metodo: datetime.timetuple ()

     Return a *note time.struct_time: ee8. such as returned by *note
     time.localtime(): 1700.

     ‘d.timetuple()’ is equivalent to:

          time.struct_time((d.year, d.month, d.day,
                            d.hour, d.minute, d.second,
                            d.weekday(), yday, dst))

     where ‘yday = d.toordinal() - date(d.year, 1, 1).toordinal() + 1’
     is the day number within the current year starting with 1 for
     January 1st.  The *note tm_isdst: 28ba. flag of the result is set
     according to the *note dst(): 28b6. method: *note tzinfo: 2891. is
     ‘None’ or *note dst(): 28b6. returns ‘None’, ‘tm_isdst’ is set to
     ‘-1’; else if *note dst(): 28b6. returns a non-zero value,
     ‘tm_isdst’ is set to 1; else ‘tm_isdst’ is set to 0.

 -- Metodo: datetime.utctimetuple ()

     If *note datetime: 4e3. instance ‘d’ is naive, this is the same as
     ‘d.timetuple()’ except that *note tm_isdst: 28ba. is forced to 0
     regardless of what ‘d.dst()’ returns.  DST is never in effect for a
     UTC time.

     If ‘d’ is aware, ‘d’ is normalized to UTC time, by subtracting
     ‘d.utcoffset()’, and a *note time.struct_time: ee8. for the
     normalized time is returned.  ‘tm_isdst’ is forced to 0.  Note that
     an *note OverflowError: a83. may be raised if ‘d.year’ was
     ‘MINYEAR’ or ‘MAXYEAR’ and UTC adjustment spills over a year
     boundary.

          Avvertimento: Because naive ‘datetime’ objects are treated by
          many ‘datetime’ methods as local times, it is preferred to use
          aware datetimes to represent times in UTC; as a result, using
          *note datetime.utctimetuple(): 28bb. may give misleading
          results.  If you have a naive ‘datetime’ representing UTC, use
          ‘datetime.replace(tzinfo=timezone.utc)’ to make it aware, at
          which point you can use *note datetime.timetuple(): 28b9.

 -- Metodo: datetime.toordinal ()

     Return the proleptic Gregorian ordinal of the date.  The same as
     ‘self.date().toordinal()’.

 -- Metodo: datetime.timestamp ()

     Return POSIX timestamp corresponding to the *note datetime: 4e3.
     instance.  The return value is a *note float: 196. similar to that
     returned by *note time.time(): 55d.

     Naive *note datetime: 4e3. instances are assumed to represent local
     time and this method relies on the platform C ‘mktime()’ function
     to perform the conversion.  Since *note datetime: 4e3. supports
     wider range of values than ‘mktime()’ on many platforms, this
     method may raise *note OverflowError: a83. or *note OSError: 2c0.
     for times far in the past or far in the future.

     For aware *note datetime: 4e3. instances, the return value is
     computed as:

          (dt - datetime(1970, 1, 1, tzinfo=timezone.utc)).total_seconds()

     Added in version 3.3.

     Cambiato nella versione 3.6: The *note timestamp(): 12a2. method
     uses the *note fold: e53. attribute to disambiguate the times
     during a repeated interval.

          Nota: There is no method to obtain the POSIX timestamp
          directly from a naive *note datetime: 4e3. instance
          representing UTC time.  If your application uses this
          convention and your system time zone is not set to UTC, you
          can obtain the POSIX timestamp by supplying
          ‘tzinfo=timezone.utc’:

               timestamp = dt.replace(tzinfo=timezone.utc).timestamp()

          or by calculating the timestamp directly:

               timestamp = (dt - datetime(1970, 1, 1)) / timedelta(seconds=1)

 -- Metodo: datetime.weekday ()

     Return the day of the week as an integer, where Monday is 0 and
     Sunday is 6.  The same as ‘self.date().weekday()’.  See also *note
     isoweekday(): 28be.

 -- Metodo: datetime.isoweekday ()

     Return the day of the week as an integer, where Monday is 1 and
     Sunday is 7.  The same as ‘self.date().isoweekday()’.  See also
     *note weekday(): 28bd, *note isocalendar(): af4.

 -- Metodo: datetime.isocalendar ()

     Return a *note named tuple: 85f. with three components: ‘year’,
     ‘week’ and ‘weekday’.  The same as ‘self.date().isocalendar()’.

 -- Metodo: datetime.isoformat (sep='T', timespec='auto')

     Return a string representing the date and time in ISO 8601 format:

        - ‘YYYY-MM-DDTHH:MM:SS.ffffff’, if *note microsecond: 2890. is
          not 0

        - ‘YYYY-MM-DDTHH:MM:SS’, if *note microsecond: 2890. is 0

     If *note utcoffset(): 28b5. does not return ‘None’, a string is
     appended, giving the UTC offset:

        - ‘YYYY-MM-DDTHH:MM:SS.ffffff+HH:MM[:SS[.ffffff]]’, if *note
          microsecond: 2890. is not 0

        - ‘YYYY-MM-DDTHH:MM:SS+HH:MM[:SS[.ffffff]]’, if *note
          microsecond: 2890. is 0

     Examples:

          >>> from datetime import datetime, timezone
          >>> datetime(2019, 5, 18, 15, 17, 8, 132263).isoformat()
          '2019-05-18T15:17:08.132263'
          >>> datetime(2019, 5, 18, 15, 17, tzinfo=timezone.utc).isoformat()
          '2019-05-18T15:17:00+00:00'

     The optional argument 'sep' (default ‘'T'’) is a one-character
     separator, placed between the date and time portions of the result.
     For example:

          >>> from datetime import tzinfo, timedelta, datetime
          >>> class TZ(tzinfo):
          ...     """A time zone with an arbitrary, constant -06:39 offset."""
          ...     def utcoffset(self, dt):
          ...         return timedelta(hours=-6, minutes=-39)
          ...
          >>> datetime(2002, 12, 25, tzinfo=TZ()).isoformat(' ')
          '2002-12-25 00:00:00-06:39'
          >>> datetime(2009, 11, 27, microsecond=100, tzinfo=TZ()).isoformat()
          '2009-11-27T00:00:00.000100-06:39'

     The optional argument 'timespec' specifies the number of additional
     components of the time to include (the default is ‘'auto'’).  It
     can be one of the following:

        - ‘'auto'’: Same as ‘'seconds'’ if *note microsecond: 2890. is
          0, same as ‘'microseconds'’ otherwise.

        - ‘'hours'’: Include the *note hour: 288d. in the two-digit ‘HH’
          format.

        - ‘'minutes'’: Include *note hour: 288d. and *note minute: 288e.
          in ‘HH:MM’ format.

        - ‘'seconds'’: Include *note hour: 288d, *note minute: 288e, and
          *note second: 288f. in ‘HH:MM:SS’ format.

        - ‘'milliseconds'’: Include full time, but truncate fractional
          second part to milliseconds.  ‘HH:MM:SS.sss’ format.

        - ‘'microseconds'’: Include full time in ‘HH:MM:SS.ffffff’
          format.

          Nota: Excluded time components are truncated, not rounded.

     *note ValueError: 2ec. will be raised on an invalid 'timespec'
     argument:

          >>> from datetime import datetime
          >>> datetime.now().isoformat(timespec='minutes')
          '2002-12-25T00:00'
          >>> dt = datetime(2015, 1, 1, 12, 30, 59, 0)
          >>> dt.isoformat(timespec='microseconds')
          '2015-01-01T12:30:59.000000'

     Cambiato nella versione 3.6: Added the 'timespec' parameter.

 -- Metodo: datetime.__str__ ()

     For a *note datetime: 4e3. instance ‘d’, ‘str(d)’ is equivalent to
     ‘d.isoformat(' ')’.

 -- Metodo: datetime.ctime ()

     Return a string representing the date and time:

          >>> from datetime import datetime
          >>> datetime(2002, 12, 4, 20, 30, 40).ctime()
          'Wed Dec  4 20:30:40 2002'

     The output string will 'not' include time zone information,
     regardless of whether the input is aware or naive.

     ‘d.ctime()’ is equivalent to:

          time.ctime(time.mktime(d.timetuple()))

     on platforms where the native C ‘ctime()’ function (which *note
     time.ctime(): 28a9. invokes, but which *note datetime.ctime():
     28c0. does not invoke) conforms to the C standard.

 -- Metodo: datetime.strftime (format)

     Return a string representing the date and time, controlled by an
     explicit format string.  See also *note strftime() and strptime()
     Behavior: 1b3c. and *note datetime.isoformat(): d27.

 -- Metodo: datetime.__format__ (format)

     Same as *note datetime.strftime(): e90.  This makes it possible to
     specify a format string for a *note datetime: 4e3. object in *note
     formatted string literals: 19a. and when using *note str.format():
     834.  See also *note strftime() and strptime() Behavior: 1b3c. and
     *note datetime.isoformat(): d27.

* Menu:

* Examples of Usage; datetime: Examples of Usage datetime.


File: python.info,  Node: Examples of Usage datetime,  Up: datetime Objects

5.8.1.11 Examples of Usage: ‘datetime’
......................................

Examples of working with *note datetime: 4e3. objects:

     >>> from datetime import datetime, date, time, timezone

     >>> # Using datetime.combine()
     >>> d = date(2005, 7, 14)
     >>> t = time(12, 30)
     >>> datetime.combine(d, t)
     datetime.datetime(2005, 7, 14, 12, 30)

     >>> # Using datetime.now()
     >>> datetime.now()
     datetime.datetime(2007, 12, 6, 16, 29, 43, 79043)   # GMT +1
     >>> datetime.now(timezone.utc)
     datetime.datetime(2007, 12, 6, 15, 29, 43, 79060, tzinfo=datetime.timezone.utc)

     >>> # Using datetime.strptime()
     >>> dt = datetime.strptime("21/11/06 16:30", "%d/%m/%y %H:%M")
     >>> dt
     datetime.datetime(2006, 11, 21, 16, 30)

     >>> # Using datetime.timetuple() to get tuple of all attributes
     >>> tt = dt.timetuple()
     >>> for it in tt:
     ...     print(it)
     ...
     2006    # year
     11      # month
     21      # day
     16      # hour
     30      # minute
     0       # second
     1       # weekday (0 = Monday)
     325     # number of days since 1st January
     -1      # dst - method tzinfo.dst() returned None

     >>> # Date in ISO format
     >>> ic = dt.isocalendar()
     >>> for it in ic:
     ...     print(it)
     ...
     2006    # ISO year
     47      # ISO week
     2       # ISO weekday

     >>> # Formatting a datetime
     >>> dt.strftime("%A, %d. %B %Y %I:%M%p")
     'Tuesday, 21. November 2006 04:30PM'
     >>> 'The {1} is {0:%d}, the {2} is {0:%B}, the {3} is {0:%I:%M%p}.'.format(dt, "day", "month", "time")
     'The day is 21, the month is November, the time is 04:30PM.'

The example below defines a *note tzinfo: 7f7. subclass capturing time
zone information for Kabul, Afghanistan, which used +4 UTC until 1945
and then +4:30 UTC thereafter:

     from datetime import timedelta, datetime, tzinfo, timezone

     class KabulTz(tzinfo):
         # Kabul used +4 until 1945, when they moved to +4:30
         UTC_MOVE_DATE = datetime(1944, 12, 31, 20, tzinfo=timezone.utc)

         def utcoffset(self, dt):
             if dt.year < 1945:
                 return timedelta(hours=4)
             elif (1945, 1, 1, 0, 0) <= dt.timetuple()[:5] < (1945, 1, 1, 0, 30):
                 # An ambiguous ("imaginary") half-hour range representing
                 # a 'fold' in time due to the shift from +4 to +4:30.
                 # If dt falls in the imaginary range, use fold to decide how
                 # to resolve. See PEP495.
                 return timedelta(hours=4, minutes=(30 if dt.fold else 0))
             else:
                 return timedelta(hours=4, minutes=30)

         def fromutc(self, dt):
             # Follow same validations as in datetime.tzinfo
             if not isinstance(dt, datetime):
                 raise TypeError("fromutc() requires a datetime argument")
             if dt.tzinfo is not self:
                 raise ValueError("dt.tzinfo is not self")

             # A custom implementation is required for fromutc as
             # the input to this function is a datetime with utc values
             # but with a tzinfo set to self.
             # See datetime.astimezone or fromtimestamp.
             if dt.replace(tzinfo=timezone.utc) >= self.UTC_MOVE_DATE:
                 return dt + timedelta(hours=4, minutes=30)
             else:
                 return dt + timedelta(hours=4)

         def dst(self, dt):
             # Kabul does not observe daylight saving time.
             return timedelta(0)

         def tzname(self, dt):
             if dt >= self.UTC_MOVE_DATE:
                 return "+04:30"
             return "+04"

Usage of ‘KabulTz’ from above:

     >>> tz1 = KabulTz()

     >>> # Datetime before the change
     >>> dt1 = datetime(1900, 11, 21, 16, 30, tzinfo=tz1)
     >>> print(dt1.utcoffset())
     4:00:00

     >>> # Datetime after the change
     >>> dt2 = datetime(2006, 6, 14, 13, 0, tzinfo=tz1)
     >>> print(dt2.utcoffset())
     4:30:00

     >>> # Convert datetime to another time zone
     >>> dt3 = dt2.astimezone(timezone.utc)
     >>> dt3
     datetime.datetime(2006, 6, 14, 8, 30, tzinfo=datetime.timezone.utc)
     >>> dt2
     datetime.datetime(2006, 6, 14, 13, 0, tzinfo=KabulTz())
     >>> dt2 == dt3
     True


File: python.info,  Node: time Objects,  Next: tzinfo Objects,  Prev: datetime Objects,  Up: datetime — Basic date and time types

5.8.1.12 ‘time’ Objects
.......................

A *note time: 1fb. object represents a (local) time of day, independent
of any particular day, and subject to adjustment via a *note tzinfo:
7f7. object.

 -- Classe: datetime.time (hour=0, minute=0, second=0, microsecond=0,
          tzinfo=None, *, fold=0)

     All arguments are optional.  'tzinfo' may be ‘None’, or an instance
     of a *note tzinfo: 7f7. subclass.  The remaining arguments must be
     integers in the following ranges:

        * ‘0 <= hour < 24’,

        * ‘0 <= minute < 60’,

        * ‘0 <= second < 60’,

        * ‘0 <= microsecond < 1000000’,

        * ‘fold in [0, 1]’.

     If an argument outside those ranges is given, *note ValueError:
     2ec. is raised.  All default to 0 except 'tzinfo', which defaults
     to ‘None’.

Class attributes:

 -- Attributo: time.min

     The earliest representable *note time: 1fb, ‘time(0, 0, 0, 0)’.

 -- Attributo: time.max

     The latest representable *note time: 1fb, ‘time(23, 59, 59,
     999999)’.

 -- Attributo: time.resolution

     The smallest possible difference between non-equal *note time: 1fb.
     objects, ‘timedelta(microseconds=1)’, although note that arithmetic
     on *note time: 1fb. objects is not supported.

Instance attributes (read-only):

 -- Attributo: time.hour

     In ‘range(24)’.

 -- Attributo: time.minute

     In ‘range(60)’.

 -- Attributo: time.second

     In ‘range(60)’.

 -- Attributo: time.microsecond

     In ‘range(1000000)’.

 -- Attributo: time.tzinfo

     The object passed as the tzinfo argument to the *note time: 1fb.
     constructor, or ‘None’ if none was passed.

 -- Attributo: time.fold

     In ‘[0, 1]’.  Used to disambiguate wall times during a repeated
     interval.  (A repeated interval occurs when clocks are rolled back
     at the end of daylight saving time or when the UTC offset for the
     current zone is decreased for political reasons.)  The values 0 and
     1 represent, respectively, the earlier and later of the two moments
     with the same wall time representation.

     Added in version 3.6.

*note time: 1fb. objects support equality and order comparisons, where
‘a’ is considered less than ‘b’ when ‘a’ precedes ‘b’ in time.

Naive and aware ‘time’ objects are never equal.  Order comparison
between naive and aware ‘time’ objects raises *note TypeError: 198.

If both comparands are aware, and have the same *note tzinfo: 2889.
attribute, the ‘tzinfo’ and ‘fold’ attributes are ignored and the base
times are compared.  If both comparands are aware and have different
‘tzinfo’ attributes, the comparands are first adjusted by subtracting
their UTC offsets (obtained from ‘self.utcoffset()’).

Cambiato nella versione 3.3: Equality comparisons between aware and
naive *note time: 1fb. instances don’t raise *note TypeError: 198.

In Boolean contexts, a *note time: 1fb. object is always considered to
be true.

Cambiato nella versione 3.5: Before Python 3.5, a *note time: 1fb.
object was considered to be false if it represented midnight in UTC.
This behavior was considered obscure and error-prone and has been
removed in Python 3.5.  See bpo-13936(1) for full details.

Other constructors:

 -- Metodo: classmethod time.fromisoformat (time_string)

     Return a *note time: 1fb. corresponding to a 'time_string' in any
     valid ISO 8601 format, with the following exceptions:

       1. Time zone offsets may have fractional seconds.

       2. The leading ‘T’, normally required in cases where there may be
          ambiguity between a date and a time, is not required.

       3. Fractional seconds may have any number of digits (anything
          beyond 6 will be truncated).

       4. Fractional hours and minutes are not supported.

     Examples:

          >>> from datetime import time
          >>> time.fromisoformat('04:23:01')
          datetime.time(4, 23, 1)
          >>> time.fromisoformat('T04:23:01')
          datetime.time(4, 23, 1)
          >>> time.fromisoformat('T042301')
          datetime.time(4, 23, 1)
          >>> time.fromisoformat('04:23:01.000384')
          datetime.time(4, 23, 1, 384)
          >>> time.fromisoformat('04:23:01,000384')
          datetime.time(4, 23, 1, 384)
          >>> time.fromisoformat('04:23:01+04:00')
          datetime.time(4, 23, 1, tzinfo=datetime.timezone(datetime.timedelta(seconds=14400)))
          >>> time.fromisoformat('04:23:01Z')
          datetime.time(4, 23, 1, tzinfo=datetime.timezone.utc)
          >>> time.fromisoformat('04:23:01+00:00')
          datetime.time(4, 23, 1, tzinfo=datetime.timezone.utc)

     Added in version 3.7.

     Cambiato nella versione 3.11: Previously, this method only
     supported formats that could be emitted by *note time.isoformat():
     28c8.

 -- Metodo: classmethod time.strptime (date_string, format)

     Return a *note time: 1fb. corresponding to 'date_string', parsed
     according to 'format'.

     If 'format' does not contain microseconds or timezone information,
     this is equivalent to:

          time(*(time.strptime(date_string, format)[3:6]))

     *note ValueError: 2ec. is raised if the 'date_string' and 'format'
     cannot be parsed by *note time.strptime(): 1634. or if it returns a
     value which is not a time tuple.  See also *note strftime() and
     strptime() Behavior: 1b3c. and *note time.fromisoformat(): 82a.

     Added in version 3.14.

Instance methods:

 -- Metodo: time.replace (hour=self.hour, minute=self.minute,
          second=self.second, microsecond=self.microsecond,
          tzinfo=self.tzinfo, *, fold=0)

     Return a new *note time: 1fb. with the same values, but with
     specified parameters updated.  Note that ‘tzinfo=None’ can be
     specified to create a naive *note time: 1fb. from an aware *note
     time: 1fb, without conversion of the time data.

     *note time: 1fb. objects are also supported by generic function
     *note copy.replace(): 1c0.

     Cambiato nella versione 3.6: Added the 'fold' parameter.

 -- Metodo: time.isoformat (timespec='auto')

     Return a string representing the time in ISO 8601 format, one of:

        - ‘HH:MM:SS.ffffff’, if *note microsecond: 2888. is not 0

        - ‘HH:MM:SS’, if *note microsecond: 2888. is 0

        - ‘HH:MM:SS.ffffff+HH:MM[:SS[.ffffff]]’, if *note utcoffset():
          28c9. does not return ‘None’

        - ‘HH:MM:SS+HH:MM[:SS[.ffffff]]’, if *note microsecond: 2888. is
          0 and *note utcoffset(): 28c9. does not return ‘None’

     The optional argument 'timespec' specifies the number of additional
     components of the time to include (the default is ‘'auto'’).  It
     can be one of the following:

        - ‘'auto'’: Same as ‘'seconds'’ if *note microsecond: 2888. is
          0, same as ‘'microseconds'’ otherwise.

        - ‘'hours'’: Include the *note hour: 2885. in the two-digit ‘HH’
          format.

        - ‘'minutes'’: Include *note hour: 2885. and *note minute: 2886.
          in ‘HH:MM’ format.

        - ‘'seconds'’: Include *note hour: 2885, *note minute: 2886, and
          *note second: 2887. in ‘HH:MM:SS’ format.

        - ‘'milliseconds'’: Include full time, but truncate fractional
          second part to milliseconds.  ‘HH:MM:SS.sss’ format.

        - ‘'microseconds'’: Include full time in ‘HH:MM:SS.ffffff’
          format.

          Nota: Excluded time components are truncated, not rounded.

     *note ValueError: 2ec. will be raised on an invalid 'timespec'
     argument.

     Example:

          >>> from datetime import time
          >>> time(hour=12, minute=34, second=56, microsecond=123456).isoformat(timespec='minutes')
          '12:34'
          >>> dt = time(hour=12, minute=34, second=56, microsecond=0)
          >>> dt.isoformat(timespec='microseconds')
          '12:34:56.000000'
          >>> dt.isoformat(timespec='auto')
          '12:34:56'

     Cambiato nella versione 3.6: Added the 'timespec' parameter.

 -- Metodo: time.__str__ ()

     For a time ‘t’, ‘str(t)’ is equivalent to ‘t.isoformat()’.

 -- Metodo: time.strftime (format)

     Return a string representing the time, controlled by an explicit
     format string.  See also *note strftime() and strptime() Behavior:
     1b3c. and *note time.isoformat(): 28c8.

 -- Metodo: time.__format__ (format)

     Same as *note time.strftime(): 1ae0.  This makes it possible to
     specify a format string for a *note time: 1fb. object in *note
     formatted string literals: 19a. and when using *note str.format():
     834.  See also *note strftime() and strptime() Behavior: 1b3c. and
     *note time.isoformat(): 28c8.

 -- Metodo: time.utcoffset ()

     If *note tzinfo: 2889. is ‘None’, returns ‘None’, else returns
     ‘self.tzinfo.utcoffset(None)’, and raises an exception if the
     latter doesn’t return ‘None’ or a *note timedelta: bc5. object with
     magnitude less than one day.

     Cambiato nella versione 3.7: The UTC offset is not restricted to a
     whole number of minutes.

 -- Metodo: time.dst ()

     If *note tzinfo: 2889. is ‘None’, returns ‘None’, else returns
     ‘self.tzinfo.dst(None)’, and raises an exception if the latter
     doesn’t return ‘None’, or a *note timedelta: bc5. object with
     magnitude less than one day.

     Cambiato nella versione 3.7: The DST offset is not restricted to a
     whole number of minutes.

 -- Metodo: time.tzname ()

     If *note tzinfo: 2889. is ‘None’, returns ‘None’, else returns
     ‘self.tzinfo.tzname(None)’, or raises an exception if the latter
     doesn’t return ‘None’ or a string object.

* Menu:

* Examples of Usage; time: Examples of Usage time.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=13936


File: python.info,  Node: Examples of Usage time,  Up: time Objects

5.8.1.13 Examples of Usage: ‘time’
..................................

Examples of working with a *note time: 1fb. object:

     >>> from datetime import time, tzinfo, timedelta
     >>> class TZ1(tzinfo):
     ...     def utcoffset(self, dt):
     ...         return timedelta(hours=1)
     ...     def dst(self, dt):
     ...         return timedelta(0)
     ...     def tzname(self,dt):
     ...         return "+01:00"
     ...     def  __repr__(self):
     ...         return f"{self.__class__.__name__}()"
     ...
     >>> t = time(12, 10, 30, tzinfo=TZ1())
     >>> t
     datetime.time(12, 10, 30, tzinfo=TZ1())
     >>> t.isoformat()
     '12:10:30+01:00'
     >>> t.dst()
     datetime.timedelta(0)
     >>> t.tzname()
     '+01:00'
     >>> t.strftime("%H:%M:%S %Z")
     '12:10:30 +01:00'
     >>> 'The {} is {:%H:%M}.'.format("time", t)
     'The time is 12:10.'


File: python.info,  Node: tzinfo Objects,  Next: timezone Objects,  Prev: time Objects,  Up: datetime — Basic date and time types

5.8.1.14 ‘tzinfo’ Objects
.........................

 -- Classe: datetime.tzinfo

     This is an abstract base class, meaning that this class should not
     be instantiated directly.  Define a subclass of *note tzinfo: 7f7.
     to capture information about a particular time zone.

     An instance of (a concrete subclass of) *note tzinfo: 7f7. can be
     passed to the constructors for *note datetime: 4e3. and *note time:
     1fb. objects.  The latter objects view their attributes as being in
     local time, and the *note tzinfo: 7f7. object supports methods
     revealing offset of local time from UTC, the name of the time zone,
     and DST offset, all relative to a date or time object passed to
     them.

     You need to derive a concrete subclass, and (at least) supply
     implementations of the standard *note tzinfo: 7f7. methods needed
     by the *note datetime: 4e3. methods you use.  The ‘datetime’ module
     provides *note timezone: 12c7, a simple concrete subclass of *note
     tzinfo: 7f7. which can represent time zones with fixed offset from
     UTC such as UTC itself or North American EST and EDT.

     Special requirement for pickling: A *note tzinfo: 7f7. subclass
     must have an *note __init__(): 8c0. method that can be called with
     no arguments, otherwise it can be pickled but possibly not
     unpickled again.  This is a technical requirement that may be
     relaxed in the future.

     A concrete subclass of *note tzinfo: 7f7. may need to implement the
     following methods.  Exactly which methods are needed depends on the
     uses made of aware ‘datetime’ objects.  If in doubt, simply
     implement all of them.

 -- Metodo: tzinfo.utcoffset (dt)

     Return offset of local time from UTC, as a *note timedelta: bc5.
     object that is positive east of UTC. If local time is west of UTC,
     this should be negative.

     This represents the 'total' offset from UTC; for example, if a
     *note tzinfo: 7f7. object represents both time zone and DST
     adjustments, *note utcoffset(): 28d1. should return their sum.  If
     the UTC offset isn’t known, return ‘None’.  Else the value returned
     must be a *note timedelta: bc5. object strictly between
     ‘-timedelta(hours=24)’ and ‘timedelta(hours=24)’ (the magnitude of
     the offset must be less than one day).  Most implementations of
     *note utcoffset(): 28d1. will probably look like one of these two:

          return CONSTANT                 # fixed-offset class
          return CONSTANT + self.dst(dt)  # daylight-aware class

     If *note utcoffset(): 28d1. does not return ‘None’, *note dst():
     28d2. should not return ‘None’ either.

     The default implementation of *note utcoffset(): 28d1. raises *note
     NotImplementedError: 36b.

     Cambiato nella versione 3.7: The UTC offset is not restricted to a
     whole number of minutes.

 -- Metodo: tzinfo.dst (dt)

     Return the daylight saving time (DST) adjustment, as a *note
     timedelta: bc5. object or ‘None’ if DST information isn’t known.

     Return ‘timedelta(0)’ if DST is not in effect.  If DST is in
     effect, return the offset as a *note timedelta: bc5. object (see
     *note utcoffset(): 28d1. for details).  Note that DST offset, if
     applicable, has already been added to the UTC offset returned by
     *note utcoffset(): 28d1, so there’s no need to consult *note dst():
     28d2. unless you’re interested in obtaining DST info separately.
     For example, *note datetime.timetuple(): 28b9. calls its *note
     tzinfo: 2891. attribute’s *note dst(): 28d2. method to determine
     how the *note tm_isdst: 28ba. flag should be set, and *note
     tzinfo.fromutc(): 28b7. calls *note dst(): 28d2. to account for DST
     changes when crossing time zones.

     An instance 'tz' of a *note tzinfo: 7f7. subclass that models both
     standard and daylight times must be consistent in this sense:

     ‘tz.utcoffset(dt) - tz.dst(dt)’

     must return the same result for every *note datetime: 4e3. 'dt'
     with ‘dt.tzinfo == tz’.  For sane *note tzinfo: 7f7. subclasses,
     this expression yields the time zone’s «standard offset», which
     should not depend on the date or the time, but only on geographic
     location.  The implementation of *note datetime.astimezone(): bc6.
     relies on this, but cannot detect violations; it’s the programmer’s
     responsibility to ensure it.  If a *note tzinfo: 7f7. subclass
     cannot guarantee this, it may be able to override the default
     implementation of *note tzinfo.fromutc(): 28b7. to work correctly
     with *note astimezone(): bc6. regardless.

     Most implementations of *note dst(): 28d2. will probably look like
     one of these two:

          def dst(self, dt):
              # a fixed-offset class:  doesn't account for DST
              return timedelta(0)

     or:

          def dst(self, dt):
              # Code to set dston and dstoff to the time zone's DST
              # transition times based on the input dt.year, and expressed
              # in standard local time.

              if dston <= dt.replace(tzinfo=None) < dstoff:
                  return timedelta(hours=1)
              else:
                  return timedelta(0)

     The default implementation of *note dst(): 28d2. raises *note
     NotImplementedError: 36b.

     Cambiato nella versione 3.7: The DST offset is not restricted to a
     whole number of minutes.

 -- Metodo: tzinfo.tzname (dt)

     Return the time zone name corresponding to the *note datetime: 4e3.
     object 'dt', as a string.  Nothing about string names is defined by
     the ‘datetime’ module, and there’s no requirement that it mean
     anything in particular.  For example, ‘"GMT"’, ‘"UTC"’, ‘"-500"’,
     ‘"-5:00"’, ‘"EDT"’, ‘"US/Eastern"’, ‘"America/New York"’ are all
     valid replies.  Return ‘None’ if a string name isn’t known.  Note
     that this is a method rather than a fixed string primarily because
     some *note tzinfo: 7f7. subclasses will wish to return different
     names depending on the specific value of 'dt' passed, especially if
     the *note tzinfo: 7f7. class is accounting for daylight time.

     The default implementation of *note tzname(): 28d3. raises *note
     NotImplementedError: 36b.

These methods are called by a *note datetime: 4e3. or *note time: 1fb.
object, in response to their methods of the same names.  A *note
datetime: 4e3. object passes itself as the argument, and a *note time:
1fb. object passes ‘None’ as the argument.  A *note tzinfo: 7f7.
subclass’s methods should therefore be prepared to accept a 'dt'
argument of ‘None’, or of class *note datetime: 4e3.

When ‘None’ is passed, it’s up to the class designer to decide the best
response.  For example, returning ‘None’ is appropriate if the class
wishes to say that time objects don’t participate in the *note tzinfo:
7f7. protocols.  It may be more useful for ‘utcoffset(None)’ to return
the standard UTC offset, as there is no other convention for discovering
the standard offset.

When a *note datetime: 4e3. object is passed in response to a *note
datetime: 4e3. method, ‘dt.tzinfo’ is the same object as 'self'.  *note
tzinfo: 7f7. methods can rely on this, unless user code calls *note
tzinfo: 7f7. methods directly.  The intent is that the *note tzinfo:
7f7. methods interpret 'dt' as being in local time, and not need worry
about objects in other time zones.

There is one more *note tzinfo: 7f7. method that a subclass may wish to
override:

 -- Metodo: tzinfo.fromutc (dt)

     This is called from the default *note datetime.astimezone(): bc6.
     implementation.  When called from that, ‘dt.tzinfo’ is 'self', and
     'dt'’s date and time data are to be viewed as expressing a UTC
     time.  The purpose of *note fromutc(): 28b7. is to adjust the date
     and time data, returning an equivalent datetime in 'self'’s local
     time.

     Most *note tzinfo: 7f7. subclasses should be able to inherit the
     default *note fromutc(): 28b7. implementation without problems.
     It’s strong enough to handle fixed-offset time zones, and time
     zones accounting for both standard and daylight time, and the
     latter even if the DST transition times differ in different years.
     An example of a time zone the default *note fromutc(): 28b7.
     implementation may not handle correctly in all cases is one where
     the standard offset (from UTC) depends on the specific date and
     time passed, which can happen for political reasons.  The default
     implementations of *note astimezone(): bc6. and *note fromutc():
     28b7. may not produce the result you want if the result is one of
     the hours straddling the moment the standard offset changes.

     Skipping code for error cases, the default *note fromutc(): 28b7.
     implementation acts like:

          def fromutc(self, dt):
              # raise ValueError error if dt.tzinfo is not self
              dtoff = dt.utcoffset()
              dtdst = dt.dst()
              # raise ValueError if dtoff is None or dtdst is None
              delta = dtoff - dtdst  # this is self's standard offset
              if delta:
                  dt += delta   # convert to standard local time
                  dtdst = dt.dst()
                  # raise ValueError if dtdst is None
              if dtdst:
                  return dt + dtdst
              else:
                  return dt

In the following ‘tzinfo_examples.py’ file there are some examples of
*note tzinfo: 7f7. classes:

     from datetime import tzinfo, timedelta, datetime

     ZERO = timedelta(0)
     HOUR = timedelta(hours=1)
     SECOND = timedelta(seconds=1)

     # A class capturing the platform's idea of local time.
     # (May result in wrong values on historical times in
     #  timezones where UTC offset and/or the DST rules had
     #  changed in the past.)
     import time as _time

     STDOFFSET = timedelta(seconds = -_time.timezone)
     if _time.daylight:
         DSTOFFSET = timedelta(seconds = -_time.altzone)
     else:
         DSTOFFSET = STDOFFSET

     DSTDIFF = DSTOFFSET - STDOFFSET

     class LocalTimezone(tzinfo):

         def fromutc(self, dt):
             assert dt.tzinfo is self
             stamp = (dt - datetime(1970, 1, 1, tzinfo=self)) // SECOND
             args = _time.localtime(stamp)[:6]
             dst_diff = DSTDIFF // SECOND
             # Detect fold
             fold = (args == _time.localtime(stamp - dst_diff))
             return datetime(*args, microsecond=dt.microsecond,
                             tzinfo=self, fold=fold)

         def utcoffset(self, dt):
             if self._isdst(dt):
                 return DSTOFFSET
             else:
                 return STDOFFSET

         def dst(self, dt):
             if self._isdst(dt):
                 return DSTDIFF
             else:
                 return ZERO

         def tzname(self, dt):
             return _time.tzname[self._isdst(dt)]

         def _isdst(self, dt):
             tt = (dt.year, dt.month, dt.day,
                   dt.hour, dt.minute, dt.second,
                   dt.weekday(), 0, 0)
             stamp = _time.mktime(tt)
             tt = _time.localtime(stamp)
             return tt.tm_isdst > 0

     Local = LocalTimezone()


     # A complete implementation of current DST rules for major US time zones.

     def first_sunday_on_or_after(dt):
         days_to_go = 6 - dt.weekday()
         if days_to_go:
             dt += timedelta(days_to_go)
         return dt


     # US DST Rules
     #
     # This is a simplified (i.e., wrong for a few cases) set of rules for US
     # DST start and end times. For a complete and up-to-date set of DST rules
     # and timezone definitions, visit the Olson Database (or try pytz):
     # http://www.twinsun.com/tz/tz-link.htm
     # https://sourceforge.net/projects/pytz/ (might not be up-to-date)
     #
     # In the US, since 2007, DST starts at 2am (standard time) on the second
     # Sunday in March, which is the first Sunday on or after Mar 8.
     DSTSTART_2007 = datetime(1, 3, 8, 2)
     # and ends at 2am (DST time) on the first Sunday of Nov.
     DSTEND_2007 = datetime(1, 11, 1, 2)
     # From 1987 to 2006, DST used to start at 2am (standard time) on the first
     # Sunday in April and to end at 2am (DST time) on the last
     # Sunday of October, which is the first Sunday on or after Oct 25.
     DSTSTART_1987_2006 = datetime(1, 4, 1, 2)
     DSTEND_1987_2006 = datetime(1, 10, 25, 2)
     # From 1967 to 1986, DST used to start at 2am (standard time) on the last
     # Sunday in April (the one on or after April 24) and to end at 2am (DST time)
     # on the last Sunday of October, which is the first Sunday
     # on or after Oct 25.
     DSTSTART_1967_1986 = datetime(1, 4, 24, 2)
     DSTEND_1967_1986 = DSTEND_1987_2006

     def us_dst_range(year):
         # Find start and end times for US DST. For years before 1967, return
         # start = end for no DST.
         if 2006 < year:
             dststart, dstend = DSTSTART_2007, DSTEND_2007
         elif 1986 < year < 2007:
             dststart, dstend = DSTSTART_1987_2006, DSTEND_1987_2006
         elif 1966 < year < 1987:
             dststart, dstend = DSTSTART_1967_1986, DSTEND_1967_1986
         else:
             return (datetime(year, 1, 1), ) * 2

         start = first_sunday_on_or_after(dststart.replace(year=year))
         end = first_sunday_on_or_after(dstend.replace(year=year))
         return start, end


     class USTimeZone(tzinfo):

         def __init__(self, hours, reprname, stdname, dstname):
             self.stdoffset = timedelta(hours=hours)
             self.reprname = reprname
             self.stdname = stdname
             self.dstname = dstname

         def __repr__(self):
             return self.reprname

         def tzname(self, dt):
             if self.dst(dt):
                 return self.dstname
             else:
                 return self.stdname

         def utcoffset(self, dt):
             return self.stdoffset + self.dst(dt)

         def dst(self, dt):
             if dt is None or dt.tzinfo is None:
                 # An exception may be sensible here, in one or both cases.
                 # It depends on how you want to treat them.  The default
                 # fromutc() implementation (called by the default astimezone()
                 # implementation) passes a datetime with dt.tzinfo is self.
                 return ZERO
             assert dt.tzinfo is self
             start, end = us_dst_range(dt.year)
             # Can't compare naive to aware objects, so strip the timezone from
             # dt first.
             dt = dt.replace(tzinfo=None)
             if start + HOUR <= dt < end - HOUR:
                 # DST is in effect.
                 return HOUR
             if end - HOUR <= dt < end:
                 # Fold (an ambiguous hour): use dt.fold to disambiguate.
                 return ZERO if dt.fold else HOUR
             if start <= dt < start + HOUR:
                 # Gap (a non-existent hour): reverse the fold rule.
                 return HOUR if dt.fold else ZERO
             # DST is off.
             return ZERO

         def fromutc(self, dt):
             assert dt.tzinfo is self
             start, end = us_dst_range(dt.year)
             start = start.replace(tzinfo=self)
             end = end.replace(tzinfo=self)
             std_time = dt + self.stdoffset
             dst_time = std_time + HOUR
             if end <= dst_time < end + HOUR:
                 # Repeated hour
                 return std_time.replace(fold=1)
             if std_time < start or dst_time >= end:
                 # Standard time
                 return std_time
             if start <= std_time < end - HOUR:
                 # Daylight saving time
                 return dst_time


     Eastern  = USTimeZone(-5, "Eastern",  "EST", "EDT")
     Central  = USTimeZone(-6, "Central",  "CST", "CDT")
     Mountain = USTimeZone(-7, "Mountain", "MST", "MDT")
     Pacific  = USTimeZone(-8, "Pacific",  "PST", "PDT")

Note that there are unavoidable subtleties twice per year in a *note
tzinfo: 7f7. subclass accounting for both standard and daylight time, at
the DST transition points.  For concreteness, consider US Eastern (UTC
-0500), where EDT begins the minute after 1:59 (EST) on the second
Sunday in March, and ends the minute after 1:59 (EDT) on the first
Sunday in November:

       UTC   3:MM  4:MM  5:MM  6:MM  7:MM  8:MM
       EST  22:MM 23:MM  0:MM  1:MM  2:MM  3:MM
       EDT  23:MM  0:MM  1:MM  2:MM  3:MM  4:MM

     start  22:MM 23:MM  0:MM  1:MM  3:MM  4:MM

       end  23:MM  0:MM  1:MM  1:MM  2:MM  3:MM

When DST starts (the «start» line), the local wall clock leaps from 1:59
to 3:00.  A wall time of the form 2:MM doesn’t really make sense on that
day, so ‘astimezone(Eastern)’ won’t deliver a result with ‘hour == 2’ on
the day DST begins.  For example, at the Spring forward transition of
2016, we get:

     >>> from datetime import datetime, timezone
     >>> from tzinfo_examples import HOUR, Eastern
     >>> u0 = datetime(2016, 3, 13, 5, tzinfo=timezone.utc)
     >>> for i in range(4):
     ...     u = u0 + i*HOUR
     ...     t = u.astimezone(Eastern)
     ...     print(u.time(), 'UTC =', t.time(), t.tzname())
     ...
     05:00:00 UTC = 00:00:00 EST
     06:00:00 UTC = 01:00:00 EST
     07:00:00 UTC = 03:00:00 EDT
     08:00:00 UTC = 04:00:00 EDT

When DST ends (the «end» line), there’s a potentially worse problem:
there’s an hour that can’t be spelled unambiguously in local wall time:
the last hour of daylight time.  In Eastern, that’s times of the form
5:MM UTC on the day daylight time ends.  The local wall clock leaps from
1:59 (daylight time) back to 1:00 (standard time) again.  Local times of
the form 1:MM are ambiguous.  *note astimezone(): bc6. mimics the local
clock’s behavior by mapping two adjacent UTC hours into the same local
hour then.  In the Eastern example, UTC times of the form 5:MM and 6:MM
both map to 1:MM when converted to Eastern, but earlier times have the
*note fold: e53. attribute set to 0 and the later times have it set to
1.  For example, at the Fall back transition of 2016, we get:

     >>> u0 = datetime(2016, 11, 6, 4, tzinfo=timezone.utc)
     >>> for i in range(4):
     ...     u = u0 + i*HOUR
     ...     t = u.astimezone(Eastern)
     ...     print(u.time(), 'UTC =', t.time(), t.tzname(), t.fold)
     ...
     04:00:00 UTC = 00:00:00 EDT 0
     05:00:00 UTC = 01:00:00 EDT 0
     06:00:00 UTC = 01:00:00 EST 1
     07:00:00 UTC = 02:00:00 EST 0

Note that the *note datetime: 4e3. instances that differ only by the
value of the *note fold: e53. attribute are considered equal in
comparisons.

Applications that can’t bear wall-time ambiguities should explicitly
check the value of the *note fold: e53. attribute or avoid using hybrid
*note tzinfo: 7f7. subclasses; there are no ambiguities when using *note
timezone: 12c7, or any other fixed-offset *note tzinfo: 7f7. subclass
(such as a class representing only EST (fixed offset -5 hours), or only
EDT (fixed offset -4 hours)).

Vedi anche
..........

     *note zoneinfo: 13a.

          The ‘datetime’ module has a basic *note timezone: 12c7. class
          (for handling arbitrary fixed offsets from UTC) and its *note
          timezone.utc: 828. attribute (a UTC ‘timezone’ instance).

          ‘zoneinfo’ brings the 'IANA time zone database' (also known as
          the Olson database) to Python, and its usage is recommended.

IANA time zone database(1)

     The Time Zone Database (often called tz, tzdata or zoneinfo)
     contains code and data that represent the history of local time for
     many representative locations around the globe.  It is updated
     periodically to reflect changes made by political bodies to time
     zone boundaries, UTC offsets, and daylight-saving rules.

   ---------- Footnotes ----------

   (1) https://www.iana.org/time-zones


File: python.info,  Node: timezone Objects,  Next: strftime and strptime Behavior,  Prev: tzinfo Objects,  Up: datetime — Basic date and time types

5.8.1.15 ‘timezone’ Objects
...........................

The *note timezone: 12c7. class is a subclass of *note tzinfo: 7f7, each
instance of which represents a time zone defined by a fixed offset from
UTC.

Objects of this class cannot be used to represent time zone information
in the locations where different offsets are used in different days of
the year or where historical changes have been made to civil time.

 -- Classe: datetime.timezone (offset, name=None)

     The 'offset' argument must be specified as a *note timedelta: bc5.
     object representing the difference between the local time and UTC.
     It must be strictly between ‘-timedelta(hours=24)’ and
     ‘timedelta(hours=24)’, otherwise *note ValueError: 2ec. is raised.

     The 'name' argument is optional.  If specified it must be a string
     that will be used as the value returned by the *note
     datetime.tzname(): 28b8. method.

     Added in version 3.2.

     Cambiato nella versione 3.7: The UTC offset is not restricted to a
     whole number of minutes.

 -- Metodo: timezone.utcoffset (dt)

     Return the fixed value specified when the *note timezone: 12c7.
     instance is constructed.

     The 'dt' argument is ignored.  The return value is a *note
     timedelta: bc5. instance equal to the difference between the local
     time and UTC.

     Cambiato nella versione 3.7: The UTC offset is not restricted to a
     whole number of minutes.

 -- Metodo: timezone.tzname (dt)

     Return the fixed value specified when the *note timezone: 12c7.
     instance is constructed.

     If 'name' is not provided in the constructor, the name returned by
     ‘tzname(dt)’ is generated from the value of the ‘offset’ as
     follows.  If 'offset' is ‘timedelta(0)’, the name is «UTC»,
     otherwise it is a string in the format ‘UTC±HH:MM’, where ± is the
     sign of ‘offset’, HH and MM are two digits of ‘offset.hours’ and
     ‘offset.minutes’ respectively.

     Cambiato nella versione 3.6: Name generated from
     ‘offset=timedelta(0)’ is now plain ‘'UTC'’, not ‘'UTC+00:00'’.

 -- Metodo: timezone.dst (dt)

     Always returns ‘None’.

 -- Metodo: timezone.fromutc (dt)

     Return ‘dt + offset’.  The 'dt' argument must be an aware *note
     datetime: 4e3. instance, with ‘tzinfo’ set to ‘self’.

Class attributes:

 -- Attributo: timezone.utc

     The UTC time zone, ‘timezone(timedelta(0))’.


File: python.info,  Node: strftime and strptime Behavior,  Prev: timezone Objects,  Up: datetime — Basic date and time types

5.8.1.16 ‘strftime()’ and ‘strptime()’ Behavior
...............................................

*note date: 1fa, *note datetime: 4e3, and *note time: 1fb. objects all
support a ‘strftime(format)’ method, to create a string representing the
time under the control of an explicit format string.

Conversely, the *note date.strptime(): 1f9, *note datetime.strptime():
1938. and *note time.strptime(): 1634. class methods create an object
from a string representing the time and a corresponding format string.

The table below provides a high-level comparison of *note strftime():
e90. versus *note strptime(): 1938.:

                     ‘strftime’                                                   ‘strptime’
                                                                                  
---------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  
Usage                Convert object to a string according to a given format       Parse a string into an object given a corresponding format
                                                                                  
                                                                                  
Type of method       Instance method                                              Class method
                                                                                  
                                                                                  
Signature            ‘strftime(format)’                                           ‘strptime(date_string, format)’
                                                                                  

* Menu:

* strftime() and strptime() Format Codes: strftime and strptime Format Codes.
* Technical Detail::


File: python.info,  Node: strftime and strptime Format Codes,  Next: Technical Detail,  Up: strftime and strptime Behavior

5.8.1.17 ‘strftime()’ and ‘strptime()’ Format Codes
...................................................

These methods accept format codes that can be used to parse and format
dates:

     >>> datetime.strptime('31/01/22 23:59:59.999999',
     ...                   '%d/%m/%y %H:%M:%S.%f')
     datetime.datetime(2022, 1, 31, 23, 59, 59, 999999)
     >>> _.strftime('%a %d %b %Y, %I:%M%p')
     'Mon 31 Jan 2022, 11:59PM'

The following is a list of all the format codes that the 1989 C standard
requires, and these work on all platforms with a standard C
implementation.

Directive       Meaning                              Example                      Notes
                                                                                  
----------------------------------------------------------------------------------------------
                                                                                  
‘%a’            Weekday as locale’s abbreviated           Sun, Mon, …, Sat (en_US);(1)
                name.                                     So, Mo, …, Sa (de_DE)   
                                                     
                                                                                  
‘%A’            Weekday as locale’s full name.            Sunday, Monday, …, Saturday (en_US);(1)
                                                          Sonntag, Montag, …, Samstag (de_DE)
                                                     
                                                                                  
‘%w’            Weekday as a decimal number, where   0, 1, …, 6
                0 is Sunday and 6 is Saturday.       
                
                                                                                  
‘%d’            Day of the month as a zero-padded    01, 02, …, 31                (9)
                decimal number.                                                   
                
                                                                                  
‘%b’            Month as locale’s abbreviated             Jan, Feb, …, Dec (en_US);(1)
                name.                                     Jan, Feb, …, Dez (de_DE)
                                                     
                                                                                  
‘%B’            Month as locale’s full name.              January, February, …, December (en_US);(1)
                                                          Januar, Februar, …, Dezember (de_DE)
                                                     
                                                                                  
‘%m’            Month as a zero-padded decimal       01, 02, …, 12                (9)
                number.                                                           
                
                                                                                  
‘%y’            Year without century as a            00, 01, …, 99                (9)
                zero-padded decimal number.                                       
                
                                                                                  
‘%Y’            Year with century as a decimal       0001, 0002, …, 2013, 2014,   (2)
                number.                              …, 9998, 9999                
                                                     
                                                                                  
‘%H’            Hour (24-hour clock) as a            00, 01, …, 23                (9)
                zero-padded decimal number.                                       
                
                                                                                  
‘%I’            Hour (12-hour clock) as a            01, 02, …, 12                (9)
                zero-padded decimal number.                                       
                
                                                                                  
‘%p’            Locale’s equivalent of either AM          AM, PM (en_US);         (1), (3)
                or PM.                                    am, pm (de_DE)          
                                                     
                                                                                  
‘%M’            Minute as a zero-padded decimal      00, 01, …, 59                (9)
                number.                                                           
                
                                                                                  
‘%S’            Second as a zero-padded decimal      00, 01, …, 59                (4), (9)
                number.                                                           
                
                                                                                  
‘%f’            Microsecond as a decimal number,     000000, 000001, …, 999999    (5)
                zero-padded to 6 digits.                                          
                
                                                                                  
‘%z’            UTC offset in the form               (empty), +0000, -0400,       (6)
                ‘±HHMM[SS[.ffffff]]’ (empty string   +1030, +063415,              
                if the object is naive).             -030712.345216
                                                     
                                                                                  
‘%Z’            Time zone name (empty string if      (empty), UTC, GMT            (6)
                the object is naive).                                             
                
                                                                                  
‘%j’            Day of the year as a zero-padded     001, 002, …, 366             (9)
                decimal number.                                                   
                
                                                                                  
‘%U’            Week number of the year (Sunday as   00, 01, …, 53                (7), (9)
                the first day of the week) as a                                   
                zero-padded decimal number.  All
                days in a new year preceding the
                first Sunday are considered to be
                in week 0.
                
                                                                                  
‘%W’            Week number of the year (Monday as   00, 01, …, 53                (7), (9)
                the first day of the week) as a                                   
                zero-padded decimal number.  All
                days in a new year preceding the
                first Monday are considered to be
                in week 0.
                
                                                                                  
‘%c’            Locale’s appropriate date and time        Tue Aug 16 21:30:00 1988 (en_US);(1)
                representation.                           Di 16 Aug 21:30:00 1988 (de_DE)
                                                     
                                                                                  
‘%x’            Locale’s appropriate date                 08/16/88 (None);        (1)
                representation.                           08/16/1988 (en_US);     
                                                          16.08.1988 (de_DE)
                                                     
                                                                                  
‘%X’            Locale’s appropriate time                 21:30:00 (en_US);       (1)
                representation.                           21:30:00 (de_DE)        
                                                     
                                                                                  
‘%%’            A literal ‘'%'’ character.           %
                                                     

Several additional directives not required by the C89 standard are
included for convenience.  These parameters all correspond to ISO 8601
date values.

Directive       Meaning                              Example                      Notes
                                                                                  
----------------------------------------------------------------------------------------------
                                                                                  
‘%G’            ISO 8601 year with century           0001, 0002, …, 2013, 2014,   (8)
                representing the year that           …, 9998, 9999                
                contains the greater part of the     
                ISO week (‘%V’).
                
                                                                                  
‘%u’            ISO 8601 weekday as a decimal        1, 2, …, 7
                number where 1 is Monday.            
                
                                                                                  
‘%V’            ISO 8601 week as a decimal number    01, 02, …, 53                (8), (9)
                with Monday as the first day of                                   
                the week.  Week 01 is the week
                containing Jan 4.
                
                                                                                  
‘%:z’           UTC offset in the form               (empty), +00:00, -04:00,     (6)
                ‘±HH:MM[:SS[.ffffff]]’ (empty        +10:30, +06:34:15,           
                string if the object is naive).      -03:07:12.345216
                                                     

These may not be available on all platforms when used with the *note
strftime(): e90. method.  The ISO 8601 year and ISO 8601 week directives
are not interchangeable with the year and week number directives above.
Calling *note strptime(): 1938. with incomplete or ambiguous ISO 8601
directives will raise a *note ValueError: 2ec.

The full set of format codes supported varies across platforms, because
Python calls the platform C library’s ‘strftime()’ function, and
platform variations are common.  To see the full set of format codes
supported on your platform, consult the ‘strftime(3)(1)’ documentation.
There are also differences between platforms in handling of unsupported
format specifiers.

Added in version 3.6: ‘%G’, ‘%u’ and ‘%V’ were added.

Added in version 3.12: ‘%:z’ was added.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/strftime(3)


File: python.info,  Node: Technical Detail,  Prev: strftime and strptime Format Codes,  Up: strftime and strptime Behavior

5.8.1.18 Technical Detail
.........................

Broadly speaking, ‘d.strftime(fmt)’ acts like the *note time: f4.
module’s ‘time.strftime(fmt, d.timetuple())’ although not all objects
support a *note timetuple(): 28a2. method.

For the *note datetime.strptime(): 1938. and *note date.strptime(): 1f9.
class methods, the default value is ‘1900-01-01T00:00:00.000’: any
components not specified in the format string will be pulled from the
default value.

     Nota: When used to parse partial dates lacking a year, *note
     datetime.strptime(): 1938. and *note date.strptime(): 1f9. will
     raise when encountering February 29 because the default year of
     1900 is 'not' a leap year.  Always add a default leap year to
     partial date strings before parsing.

     >>> from datetime import datetime
     >>> value = "2/29"
     >>> datetime.strptime(value, "%m/%d")
     Traceback (most recent call last):
     ...
     ValueError: day 29 must be in range 1..28 for month 2 in year 1900
     >>> datetime.strptime(f"1904 {value}", "%Y %m/%d")
     datetime.datetime(1904, 2, 29, 0, 0)

Using ‘datetime.strptime(date_string, format)’ is equivalent to:

     datetime(*(time.strptime(date_string, format)[0:6]))

except when the format includes sub-second components or time zone
offset information, which are supported in ‘datetime.strptime’ but are
discarded by ‘time.strptime’.

For *note time: 1fb. objects, the format codes for year, month, and day
should not be used, as ‘time’ objects have no such values.  If they’re
used anyway, 1900 is substituted for the year, and 1 for the month and
day.

For *note date: 1fa. objects, the format codes for hours, minutes,
seconds, and microseconds should not be used, as *note date: 1fa.
objects have no such values.  If they’re used anyway, 0 is substituted
for them.

For the same reason, handling of format strings containing Unicode code
points that can’t be represented in the charset of the current locale is
also platform-dependent.  On some platforms such code points are
preserved intact in the output, while on others ‘strftime’ may raise
*note UnicodeError: 462. or return an empty string instead.

Notes:

  1. Because the format depends on the current locale, care should be
     taken when making assumptions about the output value.  Field
     orderings will vary (for example, «month/day/year» versus
     «day/month/year»), and the output may contain non-ASCII characters.

  2. The *note strptime(): 1938. method can parse years in the full [1,
     9999] range, but years < 1000 must be zero-filled to 4-digit width.

     Cambiato nella versione 3.2: In previous versions, *note
     strftime(): e90. method was restricted to years >= 1900.

     Cambiato nella versione 3.3: In version 3.2, *note strftime(): e90.
     method was restricted to years >= 1000.

  3. When used with the *note strptime(): 1938. method, the ‘%p’
     directive only affects the output hour field if the ‘%I’ directive
     is used to parse the hour.

  4. Unlike the *note time: f4. module, the ‘datetime’ module does not
     support leap seconds.

  5. When used with the *note strptime(): 1938. method, the ‘%f’
     directive accepts from one to six digits and zero pads on the
     right.  ‘%f’ is an extension to the set of format characters in the
     C standard (but implemented separately in datetime objects, and
     therefore always available).

  6. For a naive object, the ‘%z’, ‘%:z’ and ‘%Z’ format codes are
     replaced by empty strings.

     For an aware object:

     ‘%z’

          *note utcoffset(): 28b5. is transformed into a string of the
          form ‘±HHMM[SS[.ffffff]]’, where ‘HH’ is a 2-digit string
          giving the number of UTC offset hours, ‘MM’ is a 2-digit
          string giving the number of UTC offset minutes, ‘SS’ is a
          2-digit string giving the number of UTC offset seconds and
          ‘ffffff’ is a 6-digit string giving the number of UTC offset
          microseconds.  The ‘ffffff’ part is omitted when the offset is
          a whole number of seconds and both the ‘ffffff’ and the ‘SS’
          part is omitted when the offset is a whole number of minutes.
          For example, if *note utcoffset(): 28b5. returns
          ‘timedelta(hours=-3, minutes=-30)’, ‘%z’ is replaced with the
          string ‘'-0330'’.

     Cambiato nella versione 3.7: The UTC offset is not restricted to a
     whole number of minutes.

     Cambiato nella versione 3.7: When the ‘%z’ directive is provided to
     the *note strptime(): 1938. method, the UTC offsets can have a
     colon as a separator between hours, minutes and seconds.  For
     example, ‘'+01:00:00'’ will be parsed as an offset of one hour.  In
     addition, providing ‘'Z'’ is identical to ‘'+00:00'’.

     ‘%:z’

          Behaves exactly as ‘%z’, but has a colon separator added
          between hours, minutes and seconds.

     ‘%Z’

          In *note strftime(): e90, ‘%Z’ is replaced by an empty string
          if *note tzname(): 28b8. returns ‘None’; otherwise ‘%Z’ is
          replaced by the returned value, which must be a string.

          *note strptime(): 1938. only accepts certain values for ‘%Z’:

            1. any value in ‘time.tzname’ for your machine’s locale

            2. the hard-coded values ‘UTC’ and ‘GMT’

          So someone living in Japan may have ‘JST’, ‘UTC’, and ‘GMT’ as
          valid values, but probably not ‘EST’.  It will raise
          ‘ValueError’ for invalid values.

     Cambiato nella versione 3.2: When the ‘%z’ directive is provided to
     the *note strptime(): 1938. method, an aware *note datetime: 4e3.
     object will be produced.  The ‘tzinfo’ of the result will be set to
     a *note timezone: 12c7. instance.

  7. When used with the *note strptime(): 1938. method, ‘%U’ and ‘%W’
     are only used in calculations when the day of the week and the
     calendar year (‘%Y’) are specified.

  8. Similar to ‘%U’ and ‘%W’, ‘%V’ is only used in calculations when
     the day of the week and the ISO year (‘%G’) are specified in a
     *note strptime(): 1938. format string.  Also note that ‘%G’ and
     ‘%Y’ are not interchangeable.

  9. When used with the *note strptime(): 1938. method, the leading zero
     is optional for formats ‘%d’, ‘%m’, ‘%H’, ‘%I’, ‘%M’, ‘%S’, ‘%j’,
     ‘%U’, ‘%W’, and ‘%V’.  Format ‘%y’ does require a leading zero.

  10. When parsing a month and day using *note strptime(): 1938, always
     include a year in the format.  If the value you need to parse lacks
     a year, append an explicit dummy leap year.  Otherwise your code
     will raise an exception when it encounters leap day because the
     default year used by the parser (1900) is not a leap year.  Users
     run into that bug every leap year.

          >>> month_day = "02/29"
          >>> datetime.strptime(f"{month_day};1984", "%m/%d;%Y")  # No leap year bug.
          datetime.datetime(1984, 2, 29, 0, 0)

     Deprecated since version 3.13, will be removed in version 3.15:
     *note strptime(): 1938. calls using a format string containing a
     day of month without a year now emit a *note DeprecationWarning:
     1a3.  In 3.15 or later we may change this into an error or change
     the default year to a leap year.  See gh-70647(1).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/70647


File: python.info,  Node: zoneinfo — IANA time zone support,  Next: calendar — General calendar-related functions,  Prev: datetime — Basic date and time types,  Up: Data Types

5.8.2 ‘zoneinfo’ — IANA time zone support
-----------------------------------------

Added in version 3.9.

'Source code:' Lib/zoneinfo(1)

__________________________________________________________________

The *note zoneinfo: 13a. module provides a concrete time zone
implementation to support the IANA time zone database as originally
specified in PEP 615(2).  By default, *note zoneinfo: 13a. uses the
system’s time zone data if available; if no system time zone data is
available, the library will fall back to using the first-party tzdata(3)
package available on PyPI.

Vedi anche
..........

Module: *note datetime: 34.

     Provides the *note time: 1fb. and *note datetime: 4e3. types with
     which the *note ZoneInfo: ade. class is designed to be used.

Package tzdata(4)

     First-party package maintained by the CPython core developers to
     supply time zone data via PyPI.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

* Menu:

* Using ZoneInfo::
* Data sources::
* The ZoneInfo class::
* Functions: Functions<2>.
* Globals::
* Exceptions and warnings::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/zoneinfo

   (2) https://peps.python.org/pep-0615/

   (3) https://pypi.org/project/tzdata/

   (4) https://pypi.org/project/tzdata/


File: python.info,  Node: Using ZoneInfo,  Next: Data sources,  Up: zoneinfo — IANA time zone support

5.8.2.1 Using ‘ZoneInfo’
........................

*note ZoneInfo: ade. is a concrete implementation of the *note
datetime.tzinfo: 7f7. abstract base class, and is intended to be
attached to ‘tzinfo’, either via the constructor, the *note
datetime.replace: 16d2. method or *note datetime.astimezone: bc6.:

     >>> from zoneinfo import ZoneInfo
     >>> from datetime import datetime, timedelta

     >>> dt = datetime(2020, 10, 31, 12, tzinfo=ZoneInfo("America/Los_Angeles"))
     >>> print(dt)
     2020-10-31 12:00:00-07:00

     >>> dt.tzname()
     'PDT'

Datetimes constructed in this way are compatible with datetime
arithmetic and handle daylight saving time transitions with no further
intervention:

     >>> dt_add = dt + timedelta(days=1)

     >>> print(dt_add)
     2020-11-01 12:00:00-08:00

     >>> dt_add.tzname()
     'PST'

These time zones also support the *note fold: e53. attribute introduced
in PEP 495(1).  During offset transitions which induce ambiguous times
(such as a daylight saving time to standard time transition), the offset
from 'before' the transition is used when ‘fold=0’, and the offset
'after' the transition is used when ‘fold=1’, for example:

     >>> dt = datetime(2020, 11, 1, 1, tzinfo=ZoneInfo("America/Los_Angeles"))
     >>> print(dt)
     2020-11-01 01:00:00-07:00

     >>> print(dt.replace(fold=1))
     2020-11-01 01:00:00-08:00

When converting from another time zone, the fold will be set to the
correct value:

     >>> from datetime import timezone
     >>> LOS_ANGELES = ZoneInfo("America/Los_Angeles")
     >>> dt_utc = datetime(2020, 11, 1, 8, tzinfo=timezone.utc)

     >>> # Before the PDT -> PST transition
     >>> print(dt_utc.astimezone(LOS_ANGELES))
     2020-11-01 01:00:00-07:00

     >>> # After the PDT -> PST transition
     >>> print((dt_utc + timedelta(hours=1)).astimezone(LOS_ANGELES))
     2020-11-01 01:00:00-08:00

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0495/


File: python.info,  Node: Data sources,  Next: The ZoneInfo class,  Prev: Using ZoneInfo,  Up: zoneinfo — IANA time zone support

5.8.2.2 Data sources
....................

The ‘zoneinfo’ module does not directly provide time zone data, and
instead pulls time zone information from the system time zone database
or the first-party PyPI package tzdata(1), if available.  Some systems,
including notably Windows systems, do not have an IANA database
available, and so for projects targeting cross-platform compatibility
that require time zone data, it is recommended to declare a dependency
on tzdata.  If neither system data nor tzdata are available, all calls
to *note ZoneInfo: ade. will raise *note ZoneInfoNotFoundError: 17fe.

* Menu:

* Configuring the data sources::

   ---------- Footnotes ----------

   (1) https://pypi.org/project/tzdata/


File: python.info,  Node: Configuring the data sources,  Up: Data sources

5.8.2.3 Configuring the data sources
....................................

When ‘ZoneInfo(key)’ is called, the constructor first searches the
directories specified in *note TZPATH: 214f. for a file matching ‘key’,
and on failure looks for a match in the tzdata package.  This behavior
can be configured in three ways:

  1. The default *note TZPATH: 214f. when not otherwise specified can be
     configured at *note compile time: 2150.

  2. *note TZPATH: 214f. can be configured using *note an environment
     variable: 28e4.

  3. At *note runtime: 28e5, the search path can be manipulated using
     the *note reset_tzpath(): 17a8. function.

* Menu:

* Compile-time configuration::
* Environment configuration::
* Runtime configuration::


File: python.info,  Node: Compile-time configuration,  Next: Environment configuration,  Up: Configuring the data sources

5.8.2.4 Compile-time configuration
..................................

The default *note TZPATH: 214f. includes several common deployment
locations for the time zone database (except on Windows, where there are
no «well-known» locations for time zone data).  On POSIX systems,
downstream distributors and those building Python from source who know
where their system time zone data is deployed may change the default
time zone path by specifying the compile-time option ‘TZPATH’ (or, more
likely, the *note configure flag -with-tzpath: 214e.), which should be a
string delimited by *note os.pathsep: 211d.

On all platforms, the configured value is available as the ‘TZPATH’ key
in *note sysconfig.get_config_var(): 174.


File: python.info,  Node: Environment configuration,  Next: Runtime configuration,  Prev: Compile-time configuration,  Up: Configuring the data sources

5.8.2.5 Environment configuration
.................................

When initializing *note TZPATH: 214f. (either at import time or whenever
*note reset_tzpath(): 17a8. is called with no arguments), the ‘zoneinfo’
module will use the environment variable ‘PYTHONTZPATH’, if it exists,
to set the search path.

 -- Variabile d'ambiente: PYTHONTZPATH

     This is an *note os.pathsep: 211d.-separated string containing the
     time zone search path to use.  It must consist of only absolute
     rather than relative paths.  Relative components specified in
     ‘PYTHONTZPATH’ will not be used, but otherwise the behavior when a
     relative path is specified is implementation-defined; CPython will
     raise *note InvalidTZPathWarning: 28e9, but other implementations
     are free to silently ignore the erroneous component or raise an
     exception.

To set the system to ignore the system data and use the tzdata package
instead, set ‘PYTHONTZPATH=""’.


File: python.info,  Node: Runtime configuration,  Prev: Environment configuration,  Up: Configuring the data sources

5.8.2.6 Runtime configuration
.............................

The TZ search path can also be configured at runtime using the *note
reset_tzpath(): 17a8. function.  This is generally not an advisable
operation, though it is reasonable to use it in test functions that
require the use of a specific time zone path (or require disabling
access to the system time zones).


File: python.info,  Node: The ZoneInfo class,  Next: Functions<2>,  Prev: Data sources,  Up: zoneinfo — IANA time zone support

5.8.2.7 The ‘ZoneInfo’ class
............................

 -- Classe: zoneinfo.ZoneInfo (key)

     A concrete *note datetime.tzinfo: 7f7. subclass that represents an
     IANA time zone specified by the string ‘key’.  Calls to the primary
     constructor will always return objects that compare identically;
     put another way, barring cache invalidation via *note
     ZoneInfo.clear_cache(): 28ec, for all values of ‘key’, the
     following assertion will always be true:

          a = ZoneInfo(key)
          b = ZoneInfo(key)
          assert a is b

     ‘key’ must be in the form of a relative, normalized POSIX path,
     with no up-level references.  The constructor will raise *note
     ValueError: 2ec. if a non-conforming key is passed.

     If no file matching ‘key’ is found, the constructor will raise
     *note ZoneInfoNotFoundError: 17fe.

The ‘ZoneInfo’ class has two alternate constructors:

 -- Metodo: classmethod ZoneInfo.from_file (file_obj, /, key=None)

     Constructs a ‘ZoneInfo’ object from a file-like object returning
     bytes (e.g.  a file opened in binary mode or an *note io.BytesIO:
     10a6. object).  Unlike the primary constructor, this always
     constructs a new object.

     The ‘key’ parameter sets the name of the zone for the purposes of
     *note __str__(): 831. and *note __repr__(): 830.

     Objects created via this constructor cannot be pickled (see *note
     pickling: 28ed.).

     *note ValueError: 2ec. is raised if the data read from 'file_obj'
     is not a valid TZif file.

 -- Metodo: classmethod ZoneInfo.no_cache (key)

     An alternate constructor that bypasses the constructor’s cache.  It
     is identical to the primary constructor, but returns a new object
     on each call.  This is most likely to be useful for testing or
     demonstration purposes, but it can also be used to create a system
     with a different cache invalidation strategy.

     Objects created via this constructor will also bypass the cache of
     a deserializing process when unpickled.

          Attenzione: Using this constructor may change the semantics of
          your datetimes in surprising ways, only use it if you know
          that you need to.

The following class methods are also available:

 -- Metodo: classmethod ZoneInfo.clear_cache (*, only_keys=None)

     A method for invalidating the cache on the ‘ZoneInfo’ class.  If no
     arguments are passed, all caches are invalidated and the next call
     to the primary constructor for each key will return a new instance.

     If an iterable of key names is passed to the ‘only_keys’ parameter,
     only the specified keys will be removed from the cache.  Keys
     passed to ‘only_keys’ but not found in the cache are ignored.

          Avvertimento: Invoking this function may change the semantics
          of datetimes using ‘ZoneInfo’ in surprising ways; this
          modifies module state and thus may have wide-ranging effects.
          Only use it if you know that you need to.

The class has one attribute:

 -- Attributo: ZoneInfo.key

     This is a read-only *note attribute: 28f0. that returns the value
     of ‘key’ passed to the constructor, which should be a lookup key in
     the IANA time zone database (e.g.  ‘America/New_York’,
     ‘Europe/Paris’ or ‘Asia/Tokyo’).

     For zones constructed from file without specifying a ‘key’
     parameter, this will be set to ‘None’.

          Nota: Although it is a somewhat common practice to expose
          these to end users, these values are designed to be primary
          keys for representing the relevant zones and not necessarily
          user-facing elements.  Projects like CLDR (the Unicode Common
          Locale Data Repository) can be used to get more user-friendly
          strings from these keys.

* Menu:

* String representations::
* Pickle serialization::


File: python.info,  Node: String representations,  Next: Pickle serialization,  Up: The ZoneInfo class

5.8.2.8 String representations
..............................

The string representation returned when calling *note str: 169. on a
*note ZoneInfo: ade. object defaults to using the *note ZoneInfo.key:
28ef. attribute (see the note on usage in the attribute documentation):

     >>> zone = ZoneInfo("Pacific/Kwajalein")
     >>> str(zone)
     'Pacific/Kwajalein'

     >>> dt = datetime(2020, 4, 1, 3, 15, tzinfo=zone)
     >>> f"{dt.isoformat()} [{dt.tzinfo}]"
     '2020-04-01T03:15:00+12:00 [Pacific/Kwajalein]'

For objects constructed from a file without specifying a ‘key’
parameter, ‘str’ falls back to calling *note repr(): 1c1.  ‘ZoneInfo’’s
‘repr’ is implementation-defined and not necessarily stable between
versions, but it is guaranteed not to be a valid ‘ZoneInfo’ key.


File: python.info,  Node: Pickle serialization,  Prev: String representations,  Up: The ZoneInfo class

5.8.2.9 Pickle serialization
............................

Rather than serializing all transition data, ‘ZoneInfo’ objects are
serialized by key, and ‘ZoneInfo’ objects constructed from files (even
those with a value for ‘key’ specified) cannot be pickled.

The behavior of a ‘ZoneInfo’ file depends on how it was constructed:

  1. ‘ZoneInfo(key)’: When constructed with the primary constructor, a
     ‘ZoneInfo’ object is serialized by key, and when deserialized, the
     deserializing process uses the primary and thus it is expected that
     these are the same object as other references to the same time
     zone.  For example, if ‘europe_berlin_pkl’ is a string containing a
     pickle constructed from ‘ZoneInfo("Europe/Berlin")’, one would
     expect the following behavior:

          >>> a = ZoneInfo("Europe/Berlin")
          >>> b = pickle.loads(europe_berlin_pkl)
          >>> a is b
          True

  2. ‘ZoneInfo.no_cache(key)’: When constructed from the cache-bypassing
     constructor, the ‘ZoneInfo’ object is also serialized by key, but
     when deserialized, the deserializing process uses the cache
     bypassing constructor.  If ‘europe_berlin_pkl_nc’ is a string
     containing a pickle constructed from
     ‘ZoneInfo.no_cache("Europe/Berlin")’, one would expect the
     following behavior:

          >>> a = ZoneInfo("Europe/Berlin")
          >>> b = pickle.loads(europe_berlin_pkl_nc)
          >>> a is b
          False

  3. ‘ZoneInfo.from_file(file_obj, /, key=None)’: When constructed from
     a file, the ‘ZoneInfo’ object raises an exception on pickling.  If
     an end user wants to pickle a ‘ZoneInfo’ constructed from a file,
     it is recommended that they use a wrapper type or a custom
     serialization function: either serializing by key or storing the
     contents of the file object and serializing that.

This method of serialization requires that the time zone data for the
required key be available on both the serializing and deserializing
side, similar to the way that references to classes and functions are
expected to exist in both the serializing and deserializing
environments.  It also means that no guarantees are made about the
consistency of results when unpickling a ‘ZoneInfo’ pickled in an
environment with a different version of the time zone data.


File: python.info,  Node: Functions<2>,  Next: Globals,  Prev: The ZoneInfo class,  Up: zoneinfo — IANA time zone support

5.8.2.10 Functions
..................

 -- Funzione: zoneinfo.available_timezones ()

     Get a set containing all the valid keys for IANA time zones
     available anywhere on the time zone path.  This is recalculated on
     every call to the function.

     This function only includes canonical zone names and does not
     include «special» zones such as those under the ‘posix/’ and
     ‘right/’ directories, or the ‘posixrules’ zone.

          Attenzione: This function may open a large number of files, as
          the best way to determine if a file on the time zone path is a
          valid time zone is to read the «magic string» at the
          beginning.

          Nota: These values are not designed to be exposed to
          end-users; for user facing elements, applications should use
          something like CLDR (the Unicode Common Locale Data
          Repository) to get more user-friendly strings.  See also the
          cautionary note on *note ZoneInfo.key: 28ef.

 -- Funzione: zoneinfo.reset_tzpath (to=None)

     Sets or resets the time zone search path (*note TZPATH: 214f.) for
     the module.  When called with no arguments, *note TZPATH: 214f. is
     set to the default value.

     Calling ‘reset_tzpath’ will not invalidate the *note ZoneInfo: ade.
     cache, and so calls to the primary ‘ZoneInfo’ constructor will only
     use the new ‘TZPATH’ in the case of a cache miss.

     The ‘to’ parameter must be a *note sequence: 717. of strings or
     *note os.PathLike: e4d. and not a string, all of which must be
     absolute paths.  *note ValueError: 2ec. will be raised if something
     other than an absolute path is passed.


File: python.info,  Node: Globals,  Next: Exceptions and warnings,  Prev: Functions<2>,  Up: zoneinfo — IANA time zone support

5.8.2.11 Globals
................

 -- Dati: zoneinfo.TZPATH

     A read-only sequence representing the time zone search path – when
     constructing a ‘ZoneInfo’ from a key, the key is joined to each
     entry in the ‘TZPATH’, and the first file found is used.

     ‘TZPATH’ may contain only absolute paths, never relative paths,
     regardless of how it is configured.

     The object that ‘zoneinfo.TZPATH’ points to may change in response
     to a call to *note reset_tzpath(): 17a8, so it is recommended to
     use ‘zoneinfo.TZPATH’ rather than importing ‘TZPATH’ from
     ‘zoneinfo’ or assigning a long-lived variable to ‘zoneinfo.TZPATH’.

     For more information on configuring the time zone search path, see
     *note Configuring the data sources: 28e3.


File: python.info,  Node: Exceptions and warnings,  Prev: Globals,  Up: zoneinfo — IANA time zone support

5.8.2.12 Exceptions and warnings
................................

 -- Eccezione: zoneinfo.ZoneInfoNotFoundError

     Raised when construction of a *note ZoneInfo: ade. object fails
     because the specified key could not be found on the system.  This
     is a subclass of *note KeyError: 5e7.

 -- Eccezione: zoneinfo.InvalidTZPathWarning

     Raised when *note PYTHONTZPATH: 28e8. contains an invalid component
     that will be filtered out, such as a relative path.


File: python.info,  Node: calendar — General calendar-related functions,  Next: collections — Container datatypes,  Prev: zoneinfo — IANA time zone support,  Up: Data Types

5.8.3 ‘calendar’ — General calendar-related functions
-----------------------------------------------------

'Source code:' Lib/calendar.py(1)

__________________________________________________________________

This module allows you to output calendars like the Unix ‘cal’ program,
and provides additional useful functions related to the calendar.  By
default, these calendars have Monday as the first day of the week, and
Sunday as the last (the European convention).  Use *note
setfirstweekday(): 28f9. to set the first day of the week to Sunday (6)
or to any other weekday.  Parameters that specify dates are given as
integers.  For related functionality, see also the *note datetime: 34.
and *note time: f4. modules.

The functions and classes defined in this module use an idealized
calendar, the current Gregorian calendar extended indefinitely in both
directions.  This matches the definition of the «proleptic Gregorian»
calendar in Dershowitz and Reingold’s book «Calendrical Calculations»,
where it’s the base calendar for all computations.  Zero and negative
years are interpreted as prescribed by the ISO 8601 standard.  Year 0 is
1 BC, year -1 is 2 BC, and so on.

 -- Classe: calendar.Calendar (firstweekday=0)

     Creates a *note Calendar: 28fa. object.  'firstweekday' is an
     integer specifying the first day of the week.  *note MONDAY: 28fb.
     is ‘0’ (the default), *note SUNDAY: 28fc. is ‘6’.

     A *note Calendar: 28fa. object provides several methods that can be
     used for preparing the calendar data for formatting.  This class
     doesn’t do any formatting itself.  This is the job of subclasses.

     *note Calendar: 28fa. instances have the following methods and
     attributes:

      -- Attributo: firstweekday

          The first weekday as an integer (0–6).

          This property can also be set and read using *note
          setfirstweekday(): 28fe. and *note getfirstweekday(): 28ff.
          respectively.

      -- Metodo: getfirstweekday ()

          Return an *note int: 19b. for the current first weekday (0–6).

          Identical to reading the *note firstweekday: 28fd. property.

      -- Metodo: setfirstweekday (firstweekday)

          Set the first weekday to 'firstweekday', passed as an *note
          int: 19b. (0–6)

          Identical to setting the *note firstweekday: 28fd. property.

      -- Metodo: iterweekdays ()

          Return an iterator for the week day numbers that will be used
          for one week.  The first value from the iterator will be the
          same as the value of the *note firstweekday: 28fd. property.

      -- Metodo: itermonthdates (year, month)

          Return an iterator for the month 'month' (1–12) in the year
          'year'.  This iterator will return all days (as *note
          datetime.date: 1fa. objects) for the month and all days before
          the start of the month or after the end of the month that are
          required to get a complete week.

      -- Metodo: itermonthdays (year, month)

          Return an iterator for the month 'month' in the year 'year'
          similar to *note itermonthdates(): e15, but not restricted by
          the *note datetime.date: 1fa. range.  Days returned will
          simply be day of the month numbers.  For the days outside of
          the specified month, the day number is ‘0’.

      -- Metodo: itermonthdays2 (year, month)

          Return an iterator for the month 'month' in the year 'year'
          similar to *note itermonthdates(): e15, but not restricted by
          the *note datetime.date: 1fa. range.  Days returned will be
          tuples consisting of a day of the month number and a week day
          number.

      -- Metodo: itermonthdays3 (year, month)

          Return an iterator for the month 'month' in the year 'year'
          similar to *note itermonthdates(): e15, but not restricted by
          the *note datetime.date: 1fa. range.  Days returned will be
          tuples consisting of a year, a month and a day of the month
          numbers.

          Added in version 3.7.

      -- Metodo: itermonthdays4 (year, month)

          Return an iterator for the month 'month' in the year 'year'
          similar to *note itermonthdates(): e15, but not restricted by
          the *note datetime.date: 1fa. range.  Days returned will be
          tuples consisting of a year, a month, a day of the month, and
          a day of the week numbers.

          Added in version 3.7.

      -- Metodo: monthdatescalendar (year, month)

          Return a list of the weeks in the month 'month' of the 'year'
          as full weeks.  Weeks are lists of seven *note datetime.date:
          1fa. objects.

      -- Metodo: monthdays2calendar (year, month)

          Return a list of the weeks in the month 'month' of the 'year'
          as full weeks.  Weeks are lists of seven tuples of day numbers
          and weekday numbers.

      -- Metodo: monthdayscalendar (year, month)

          Return a list of the weeks in the month 'month' of the 'year'
          as full weeks.  Weeks are lists of seven day numbers.

      -- Metodo: yeardatescalendar (year, width=3)

          Return the data for the specified year ready for formatting.
          The return value is a list of month rows.  Each month row
          contains up to 'width' months (defaulting to 3).  Each month
          contains between 4 and 6 weeks and each week contains 1–7
          days.  Days are *note datetime.date: 1fa. objects.

      -- Metodo: yeardays2calendar (year, width=3)

          Return the data for the specified year ready for formatting
          (similar to *note yeardatescalendar(): 2906.).  Entries in the
          week lists are tuples of day numbers and weekday numbers.  Day
          numbers outside this month are zero.

      -- Metodo: yeardayscalendar (year, width=3)

          Return the data for the specified year ready for formatting
          (similar to *note yeardatescalendar(): 2906.).  Entries in the
          week lists are day numbers.  Day numbers outside this month
          are zero.

 -- Classe: calendar.TextCalendar (firstweekday=0)

     This class can be used to generate plain text calendars.

     *note TextCalendar: 1892. instances have the following methods:

      -- Metodo: formatday (theday, weekday, width)

          Return a string representing a single day formatted with the
          given 'width'.  If 'theday' is ‘0’, return a string of spaces
          of the specified width, representing an empty day.  The
          'weekday' parameter is unused.

      -- Metodo: formatweek (theweek, w=0)

          Return a single week in a string with no newline.  If 'w' is
          provided, it specifies the width of the date columns, which
          are centered.  Depends on the first weekday as specified in
          the constructor or set by the *note setfirstweekday(): 28f9.
          method.

      -- Metodo: formatweekday (weekday, width)

          Return a string representing the name of a single weekday
          formatted to the specified 'width'.  The 'weekday' parameter
          is an integer representing the day of the week, where ‘0’ is
          Monday and ‘6’ is Sunday.

      -- Metodo: formatweekheader (width)

          Return a string containing the header row of weekday names,
          formatted with the given 'width' for each column.  The names
          depend on the locale settings and are padded to the specified
          width.

      -- Metodo: formatmonth (theyear, themonth, w=0, l=0)

          Return a month’s calendar in a multi-line string.  If 'w' is
          provided, it specifies the width of the date columns, which
          are centered.  If 'l' is given, it specifies the number of
          lines that each week will use.  Depends on the first weekday
          as specified in the constructor or set by the *note
          setfirstweekday(): 28f9. method.

      -- Metodo: formatmonthname (theyear, themonth, width=0,
               withyear=True)

          Return a string representing the month’s name centered within
          the specified 'width'.  If 'withyear' is ‘True’, include the
          year in the output.  The 'theyear' and 'themonth' parameters
          specify the year and month for the name to be formatted
          respectively.

      -- Metodo: prmonth (theyear, themonth, w=0, l=0)

          Print a month’s calendar as returned by *note formatmonth():
          290d.

      -- Metodo: formatyear (theyear, w=2, l=1, c=6, m=3)

          Return a 'm'-column calendar for an entire year as a
          multi-line string.  Optional parameters 'w', 'l', and 'c' are
          for date column width, lines per week, and number of spaces
          between month columns, respectively.  Depends on the first
          weekday as specified in the constructor or set by the *note
          setfirstweekday(): 28f9. method.  The earliest year for which
          a calendar can be generated is platform-dependent.

      -- Metodo: pryear (theyear, w=2, l=1, c=6, m=3)

          Print the calendar for an entire year as returned by *note
          formatyear(): 2910.

 -- Classe: calendar.HTMLCalendar (firstweekday=0)

     This class can be used to generate HTML calendars.

     ‘HTMLCalendar’ instances have the following methods:

      -- Metodo: formatmonth (theyear, themonth, withyear=True)

          Return a month’s calendar as an HTML table.  If 'withyear' is
          true the year will be included in the header, otherwise just
          the month name will be used.

      -- Metodo: formatyear (theyear, width=3)

          Return a year’s calendar as an HTML table.  'width'
          (defaulting to 3) specifies the number of months per row.

      -- Metodo: formatyearpage (theyear, width=3, css='calendar.css',
               encoding=None)

          Return a year’s calendar as a complete HTML page.  'width'
          (defaulting to 3) specifies the number of months per row.
          'css' is the name for the cascading style sheet to be used.
          *note None: 886. can be passed if no style sheet should be
          used.  'encoding' specifies the encoding to be used for the
          output (defaulting to the system default encoding).

      -- Metodo: formatmonthname (theyear, themonth, withyear=True)

          Return a month name as an HTML table row.  If 'withyear' is
          true the year will be included in the row, otherwise just the
          month name will be used.

     ‘HTMLCalendar’ has the following attributes you can override to
     customize the CSS classes used by the calendar:

      -- Attributo: cssclasses

          A list of CSS classes used for each weekday.  The default
          class list is:

               cssclasses = ["mon", "tue", "wed", "thu", "fri", "sat", "sun"]

          more styles can be added for each day:

               cssclasses = ["mon text-bold", "tue", "wed", "thu", "fri", "sat", "sun red"]

          Note that the length of this list must be seven items.

      -- Attributo: cssclass_noday

          The CSS class for a weekday occurring in the previous or
          coming month.

          Added in version 3.7.

      -- Attributo: cssclasses_weekday_head

          A list of CSS classes used for weekday names in the header
          row.  The default is the same as *note cssclasses: 2916.

          Added in version 3.7.

      -- Attributo: cssclass_month_head

          The month’s head CSS class (used by *note formatmonthname():
          2915.).  The default value is ‘"month"’.

          Added in version 3.7.

      -- Attributo: cssclass_month

          The CSS class for the whole month’s table (used by *note
          formatmonth(): 2912.).  The default value is ‘"month"’.

          Added in version 3.7.

      -- Attributo: cssclass_year

          The CSS class for the whole year’s table of tables (used by
          *note formatyear(): 2913.).  The default value is ‘"year"’.

          Added in version 3.7.

      -- Attributo: cssclass_year_head

          The CSS class for the table head for the whole year (used by
          *note formatyear(): 2913.).  The default value is ‘"year"’.

          Added in version 3.7.

     Note that although the naming for the above described class
     attributes is singular (e.g.  ‘cssclass_month’ ‘cssclass_noday’),
     one can replace the single CSS class with a space separated list of
     CSS classes, for example:

          "text-bold text-red"

     Here is an example how ‘HTMLCalendar’ can be customized:

          class CustomHTMLCal(calendar.HTMLCalendar):
              cssclasses = [style + " text-nowrap" for style in
                            calendar.HTMLCalendar.cssclasses]
              cssclass_month_head = "text-center month-head"
              cssclass_month = "text-center month"
              cssclass_year = "text-italic lead"

 -- Classe: calendar.LocaleTextCalendar (firstweekday=0, locale=None)

     This subclass of *note TextCalendar: 1892. can be passed a locale
     name in the constructor and will return month and weekday names in
     the specified locale.

 -- Classe: calendar.LocaleHTMLCalendar (firstweekday=0, locale=None)

     This subclass of *note HTMLCalendar: d1a. can be passed a locale
     name in the constructor and will return month and weekday names in
     the specified locale.

     Nota: The constructor, ‘formatweekday()’ and ‘formatmonthname()’
     methods of these two classes temporarily change the ‘LC_TIME’
     locale to the given 'locale'.  Because the current locale is a
     process-wide setting, they are not thread-safe.

For simple text calendars this module provides the following functions.

 -- Funzione: calendar.setfirstweekday (weekday)

     Sets the weekday (‘0’ is Monday, ‘6’ is Sunday) to start each week.
     The values *note MONDAY: 28fb, *note TUESDAY: 291d, *note
     WEDNESDAY: 291e, *note THURSDAY: 291f, *note FRIDAY: 2920, *note
     SATURDAY: 2921, and *note SUNDAY: 28fc. are provided for
     convenience.  For example, to set the first weekday to Sunday:

          import calendar
          calendar.setfirstweekday(calendar.SUNDAY)

 -- Funzione: calendar.firstweekday ()

     Returns the current setting for the weekday to start each week.

 -- Funzione: calendar.isleap (year)

     Returns *note True: e09. if 'year' is a leap year, otherwise *note
     False: d2d.

 -- Funzione: calendar.leapdays (y1, y2)

     Returns the number of leap years in the range from 'y1' to 'y2'
     (exclusive), where 'y1' and 'y2' are years.

     This function works for ranges spanning a century change.

 -- Funzione: calendar.weekday (year, month, day)

     Returns the day of the week (‘0’ is Monday) for 'year' (‘1970’–…),
     'month' (‘1’–‘12’), 'day' (‘1’–‘31’).

 -- Funzione: calendar.weekheader (n)

     Return a header containing abbreviated weekday names.  'n'
     specifies the width in characters for one weekday.

 -- Funzione: calendar.monthrange (year, month)

     Returns weekday of first day of the month and number of days in
     month, for the specified 'year' and 'month'.

 -- Funzione: calendar.monthcalendar (year, month)

     Returns a matrix representing a month’s calendar.  Each row
     represents a week; days outside of the month are represented by
     zeros.  Each week begins with Monday unless set by *note
     setfirstweekday(): 28f9.

 -- Funzione: calendar.prmonth (theyear, themonth, w=0, l=0)

     Prints a month’s calendar as returned by *note month(): 18f3.

 -- Funzione: calendar.month (theyear, themonth, w=0, l=0)

     Returns a month’s calendar in a multi-line string using the *note
     formatmonth(): 290d. of the *note TextCalendar: 1892. class.

 -- Funzione: calendar.prcal (year, w=0, l=0, c=6, m=3)

     Prints the calendar for an entire year as returned by *note
     calendar(): 15.

 -- Funzione: calendar.calendar (year, w=2, l=1, c=6, m=3)

     Returns a 3-column calendar for an entire year as a multi-line
     string using the *note formatyear(): 2910. of the *note
     TextCalendar: 1892. class.

 -- Funzione: calendar.timegm (tuple)

     An unrelated but handy function that takes a time tuple such as
     returned by the *note gmtime(): 13c8. function in the *note time:
     f4. module, and returns the corresponding Unix timestamp value,
     assuming an epoch of 1970, and the POSIX encoding.  In fact, *note
     time.gmtime(): 13c8. and *note timegm(): 292c. are each others”
     inverse.

The *note calendar: 15. module exports the following data attributes:

 -- Dati: calendar.day_name

     A sequence that represents the days of the week in the current
     locale, where Monday is day number 0.

          >>> import calendar
          >>> list(calendar.day_name)
          ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']

 -- Dati: calendar.day_abbr

     A sequence that represents the abbreviated days of the week in the
     current locale, where Mon is day number 0.

          >>> import calendar
          >>> list(calendar.day_abbr)
          ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']

 -- Dati: calendar.MONDAY
 -- Dati: calendar.TUESDAY
 -- Dati: calendar.WEDNESDAY
 -- Dati: calendar.THURSDAY
 -- Dati: calendar.FRIDAY
 -- Dati: calendar.SATURDAY
 -- Dati: calendar.SUNDAY

     Aliases for the days of the week, where ‘MONDAY’ is ‘0’ and
     ‘SUNDAY’ is ‘6’.

     Added in version 3.12.

 -- Classe: calendar.Day

     Enumeration defining days of the week as integer constants.  The
     members of this enumeration are exported to the module scope as
     *note MONDAY: 28fb. through *note SUNDAY: 28fc.

     Added in version 3.12.

 -- Dati: calendar.month_name

     A sequence that represents the months of the year in the current
     locale.  This follows normal convention of January being month
     number 1, so it has a length of 13 and ‘month_name[0]’ is the empty
     string.

          >>> import calendar
          >>> list(calendar.month_name)
          ['', 'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December']

 -- Dati: calendar.month_abbr

     A sequence that represents the abbreviated months of the year in
     the current locale.  This follows normal convention of January
     being month number 1, so it has a length of 13 and ‘month_abbr[0]’
     is the empty string.

          >>> import calendar
          >>> list(calendar.month_abbr)
          ['', 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']

 -- Dati: calendar.JANUARY
 -- Dati: calendar.FEBRUARY
 -- Dati: calendar.MARCH
 -- Dati: calendar.APRIL
 -- Dati: calendar.MAY
 -- Dati: calendar.JUNE
 -- Dati: calendar.JULY
 -- Dati: calendar.AUGUST
 -- Dati: calendar.SEPTEMBER
 -- Dati: calendar.OCTOBER
 -- Dati: calendar.NOVEMBER
 -- Dati: calendar.DECEMBER

     Aliases for the months of the year, where ‘JANUARY’ is ‘1’ and
     ‘DECEMBER’ is ‘12’.

     Added in version 3.12.

 -- Classe: calendar.Month

     Enumeration defining months of the year as integer constants.  The
     members of this enumeration are exported to the module scope as
     *note JANUARY: 34e. through *note DECEMBER: 293a.

     Added in version 3.12.

The *note calendar: 15. module defines the following exceptions:

 -- Eccezione: calendar.IllegalMonthError (month)

     A subclass of *note ValueError: 2ec, raised when the given month
     number is outside of the range 1-12 (inclusive).

      -- Attributo: month

          The invalid month number.

 -- Eccezione: calendar.IllegalWeekdayError (weekday)

     A subclass of *note ValueError: 2ec, raised when the given weekday
     number is outside of the range 0-6 (inclusive).

      -- Attributo: weekday

          The invalid weekday number.

Vedi anche
..........

Module *note datetime: 34.

     Object-oriented interface to dates and times with similar
     functionality to the *note time: f4. module.

Module *note time: f4.

     Low-level time related functions.

* Menu:

* Command-line usage::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/calendar.py


File: python.info,  Node: Command-line usage,  Up: calendar — General calendar-related functions

5.8.3.1 Command-line usage
..........................

Added in version 2.5.

The *note calendar: 15. module can be executed as a script from the
command line to interactively print a calendar.

     python -m calendar [-h] [-L LOCALE] [-e ENCODING] [-t {text,html}]
                        [-w WIDTH] [-l LINES] [-s SPACING] [-m MONTHS] [-c CSS]
                        [-f FIRST_WEEKDAY] [year] [month]

For example, to print a calendar for the year 2000:

     $ python -m calendar 2000
                                       2000

           January                   February                   March
     Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
                     1  2          1  2  3  4  5  6             1  2  3  4  5
      3  4  5  6  7  8  9       7  8  9 10 11 12 13       6  7  8  9 10 11 12
     10 11 12 13 14 15 16      14 15 16 17 18 19 20      13 14 15 16 17 18 19
     17 18 19 20 21 22 23      21 22 23 24 25 26 27      20 21 22 23 24 25 26
     24 25 26 27 28 29 30      28 29                     27 28 29 30 31
     31

            April                      May                       June
     Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
                     1  2       1  2  3  4  5  6  7                1  2  3  4
      3  4  5  6  7  8  9       8  9 10 11 12 13 14       5  6  7  8  9 10 11
     10 11 12 13 14 15 16      15 16 17 18 19 20 21      12 13 14 15 16 17 18
     17 18 19 20 21 22 23      22 23 24 25 26 27 28      19 20 21 22 23 24 25
     24 25 26 27 28 29 30      29 30 31                  26 27 28 29 30

             July                     August                  September
     Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
                     1  2          1  2  3  4  5  6                   1  2  3
      3  4  5  6  7  8  9       7  8  9 10 11 12 13       4  5  6  7  8  9 10
     10 11 12 13 14 15 16      14 15 16 17 18 19 20      11 12 13 14 15 16 17
     17 18 19 20 21 22 23      21 22 23 24 25 26 27      18 19 20 21 22 23 24
     24 25 26 27 28 29 30      28 29 30 31               25 26 27 28 29 30
     31

           October                   November                  December
     Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
                        1             1  2  3  4  5                   1  2  3
      2  3  4  5  6  7  8       6  7  8  9 10 11 12       4  5  6  7  8  9 10
      9 10 11 12 13 14 15      13 14 15 16 17 18 19      11 12 13 14 15 16 17
     16 17 18 19 20 21 22      20 21 22 23 24 25 26      18 19 20 21 22 23 24
     23 24 25 26 27 28 29      27 28 29 30               25 26 27 28 29 30 31
     30 31

The following options are accepted:

 -- Option: --help, -h

     Show the help message and exit.

 -- Option: --locale LOCALE, -L LOCALE

     The locale to use for month and weekday names.  Defaults to
     English.

 -- Option: --encoding ENCODING, -e ENCODING

     The encoding to use for output.  *note -encoding: 2943. is required
     if *note -locale: 2941. is set.

 -- Option: --type {text,html}, -t {text,html}

     Print the calendar to the terminal as text, or as an HTML document.

 -- Option: --first-weekday FIRST_WEEKDAY, -f FIRST_WEEKDAY

     The weekday to start each week.  Must be a number between 0
     (Monday) and 6 (Sunday).  Defaults to 0.

     Added in version 3.13.

 -- Option: year

     The year to print the calendar for.  Defaults to the current year.

 -- Option: month

     The month of the specified *note year: 2949. to print the calendar
     for.  Must be a number between 1 and 12, and may only be used in
     text mode.  Defaults to printing a calendar for the full year.

'Text-mode options:'

 -- Option: --width WIDTH, -w WIDTH

     The width of the date column in terminal columns.  The date is
     printed centred in the column.  Any value lower than 2 is ignored.
     Defaults to 2.

 -- Option: --lines LINES, -l LINES

     The number of lines for each week in terminal rows.  The date is
     printed top-aligned.  Any value lower than 1 is ignored.  Defaults
     to 1.

 -- Option: --spacing SPACING, -s SPACING

     The space between months in columns.  Any value lower than 2 is
     ignored.  Defaults to 6.

 -- Option: --months MONTHS, -m MONTHS

     The number of months printed per row.  Defaults to 3.

Cambiato nella versione 3.14: By default, today’s date is highlighted in
color and can be *note controlled using environment variables: 1b7.

'HTML-mode options:'

 -- Option: --css CSS, -c CSS

     The path of a CSS stylesheet to use for the calendar.  This must
     either be relative to the generated HTML, or an absolute HTTP or
     ‘file:///’ URL.


File: python.info,  Node: collections — Container datatypes,  Next: collections abc — Abstract Base Classes for Containers,  Prev: calendar — General calendar-related functions,  Up: Data Types

5.8.4 ‘collections’ — Container datatypes
-----------------------------------------

'Source code:' Lib/collections/__init__.py(1)

__________________________________________________________________

This module implements specialized container datatypes providing
alternatives to Python’s general purpose built-in containers, *note
dict: 183, *note list: 24d, *note set: 184, and *note tuple: 614.

*note namedtuple(): 4e1.  factory function for creating tuple subclasses with named fields
                          
                          
*note deque: 7f5.         list-like container with fast appends and pops on either end
                          
                          
*note ChainMap: e18.      dict-like class for creating a single view of multiple mappings
                          
                          
*note Counter: 1299.      dict subclass for counting *note hashable: 825. objects
                          
                          
*note OrderedDict: 7f4.   dict subclass that remembers the order entries were added
                          
                          
*note defaultdict: 13c4.  dict subclass that calls a factory function to supply missing values
                          
                          
*note UserDict: 1d65.     wrapper around dictionary objects for easier dict subclassing
                          
                          
*note UserList: 16eb.     wrapper around list objects for easier list subclassing
                          
                          
*note UserString: fd5.    wrapper around string objects for easier string subclassing
                          

* Menu:

* ChainMap objects::
* Counter objects::
* deque objects::
* defaultdict objects::
* namedtuple() Factory Function for Tuples with Named Fields: namedtuple Factory Function for Tuples with Named Fields.
* OrderedDict objects::
* UserDict objects::
* UserList objects::
* UserString objects::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/collections/__init__.py


File: python.info,  Node: ChainMap objects,  Next: Counter objects,  Up: collections — Container datatypes

5.8.4.1 ‘ChainMap’ objects
..........................

Added in version 3.3.

A *note ChainMap: e18. class is provided for quickly linking a number of
mappings so they can be treated as a single unit.  It is often much
faster than creating a new dictionary and running multiple *note
update(): 166c. calls.

The class can be used to simulate nested scopes and is useful in
templating.

 -- Classe: collections.ChainMap (*maps)

     A *note ChainMap: e18. groups multiple dicts or other mappings
     together to create a single, updateable view.  If no 'maps' are
     specified, a single empty dictionary is provided so that a new
     chain always has at least one mapping.

     The underlying mappings are stored in a list.  That list is public
     and can be accessed or updated using the 'maps' attribute.  There
     is no other state.

     Lookups search the underlying mappings successively until a key is
     found.  In contrast, writes, updates, and deletions only operate on
     the first mapping.

     A *note ChainMap: e18. incorporates the underlying mappings by
     reference.  So, if one of the underlying mappings gets updated,
     those changes will be reflected in *note ChainMap: e18.

     All of the usual dictionary methods are supported.  In addition,
     there is a 'maps' attribute, a method for creating new subcontexts,
     and a property for accessing all but the first mapping:

      -- Attributo: maps

          A user updateable list of mappings.  The list is ordered from
          first-searched to last-searched.  It is the only stored state
          and can be modified to change which mappings are searched.
          The list should always contain at least one mapping.

      -- Metodo: new_child (m=None, **kwargs)

          Returns a new *note ChainMap: e18. containing a new map
          followed by all of the maps in the current instance.  If ‘m’
          is specified, it becomes the new map at the front of the list
          of mappings; if not specified, an empty dict is used, so that
          a call to ‘d.new_child()’ is equivalent to: ‘ChainMap({},
          *d.maps)’.  If any keyword arguments are specified, they
          update passed map or new empty dict.  This method is used for
          creating subcontexts that can be updated without altering
          values in any of the parent mappings.

          Cambiato nella versione 3.4: The optional ‘m’ parameter was
          added.

          Cambiato nella versione 3.10: Keyword arguments support was
          added.

      -- Attributo: parents

          Property returning a new *note ChainMap: e18. containing all
          of the maps in the current instance except the first one.
          This is useful for skipping the first map in the search.  Use
          cases are similar to those for the *note nonlocal: 14af.
          keyword used in *note nested scopes: 2373.  The use cases also
          parallel those for the built-in *note super(): 1a6. function.
          A reference to ‘d.parents’ is equivalent to:
          ‘ChainMap(*d.maps[1:])’.

     Note, the iteration order of a *note ChainMap: e18. is determined
     by scanning the mappings last to first:

          >>> baseline = {'music': 'bach', 'art': 'rembrandt'}
          >>> adjustments = {'art': 'van gogh', 'opera': 'carmen'}
          >>> list(ChainMap(adjustments, baseline))
          ['music', 'art', 'opera']

     This gives the same ordering as a series of *note dict.update():
     166c. calls starting with the last mapping:

          >>> combined = baseline.copy()
          >>> combined.update(adjustments)
          >>> list(combined)
          ['music', 'art', 'opera']

     Cambiato nella versione 3.9: Added support for ‘|’ and ‘|=’
     operators, specified in PEP 584(1).

Vedi anche
..........

   * The MultiContext class(2) in the Enthought CodeTools package(3) has
     options to support writing to any mapping in the chain.

   * Django’s Context class(4) for templating is a read-only chain of
     mappings.  It also features pushing and popping of contexts similar
     to the *note new_child(): 1127. method and the *note parents: 295a.
     property.

   * The Nested Contexts recipe(5) has options to control whether writes
     and other mutations apply only to the first mapping or to any
     mapping in the chain.

   * A greatly simplified read-only version of Chainmap(6).

* Menu:

* ChainMap Examples and Recipes::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0584/

   (2) 
https://github.com/enthought/codetools/blob/4.0.0/codetools/contexts/multi_context.py

   (3) https://github.com/enthought/codetools

   (4) 
https://github.com/django/django/blob/main/django/template/context.py

   (5) 
https://code.activestate.com/recipes/577434-nested-contexts-a-chain-of-mapping-objects/

   (6) https://code.activestate.com/recipes/305268/


File: python.info,  Node: ChainMap Examples and Recipes,  Up: ChainMap objects

5.8.4.2 ‘ChainMap’ Examples and Recipes
.......................................

This section shows various approaches to working with chained maps.

Example of simulating Python’s internal lookup chain:

     import builtins
     pylookup = ChainMap(locals(), globals(), vars(builtins))

Example of letting user specified command-line arguments take precedence
over environment variables which in turn take precedence over default
values:

     import os, argparse

     defaults = {'color': 'red', 'user': 'guest'}

     parser = argparse.ArgumentParser()
     parser.add_argument('-u', '--user')
     parser.add_argument('-c', '--color')
     namespace = parser.parse_args()
     command_line_args = {k: v for k, v in vars(namespace).items() if v is not None}

     combined = ChainMap(command_line_args, os.environ, defaults)
     print(combined['color'])
     print(combined['user'])

Example patterns for using the *note ChainMap: e18. class to simulate
nested contexts:

     c = ChainMap()        # Create root context
     d = c.new_child()     # Create nested child context
     e = c.new_child()     # Child of c, independent from d
     e.maps[0]             # Current context dictionary -- like Python's locals()
     e.maps[-1]            # Root context -- like Python's globals()
     e.parents             # Enclosing context chain -- like Python's nonlocals

     d['x'] = 1            # Set value in current context
     d['x']                # Get first key in the chain of contexts
     del d['x']            # Delete from current context
     list(d)               # All nested values
     k in d                # Check all nested values
     len(d)                # Number of nested values
     d.items()             # All nested items
     dict(d)               # Flatten into a regular dictionary

The *note ChainMap: e18. class only makes updates (writes and deletions)
to the first mapping in the chain while lookups will search the full
chain.  However, if deep writes and deletions are desired, it is easy to
make a subclass that updates keys found deeper in the chain:

     class DeepChainMap(ChainMap):
         'Variant of ChainMap that allows direct updates to inner scopes'

         def __setitem__(self, key, value):
             for mapping in self.maps:
                 if key in mapping:
                     mapping[key] = value
                     return
             self.maps[0][key] = value

         def __delitem__(self, key):
             for mapping in self.maps:
                 if key in mapping:
                     del mapping[key]
                     return
             raise KeyError(key)

     >>> d = DeepChainMap({'zebra': 'black'}, {'elephant': 'blue'}, {'lion': 'yellow'})
     >>> d['lion'] = 'orange'         # update an existing key two levels down
     >>> d['snake'] = 'red'           # new keys get added to the topmost dict
     >>> del d['elephant']            # remove an existing key one level down
     >>> d                            # display result
     DeepChainMap({'zebra': 'black', 'snake': 'red'}, {}, {'lion': 'orange'})


File: python.info,  Node: Counter objects,  Next: deque objects,  Prev: ChainMap objects,  Up: collections — Container datatypes

5.8.4.3 ‘Counter’ objects
.........................

A counter tool is provided to support convenient and rapid tallies.  For
example:

     >>> # Tally occurrences of words in a list
     >>> cnt = Counter()
     >>> for word in ['red', 'blue', 'red', 'green', 'blue', 'blue']:
     ...     cnt[word] += 1
     ...
     >>> cnt
     Counter({'blue': 3, 'red': 2, 'green': 1})

     >>> # Find the ten most common words in Hamlet
     >>> import re
     >>> words = re.findall(r'\w+', open('hamlet.txt').read().lower())
     >>> Counter(words).most_common(10)
     [('the', 1143), ('and', 966), ('to', 762), ('of', 669), ('i', 631),
      ('you', 554),  ('a', 546), ('my', 514), ('hamlet', 471), ('in', 451)]

 -- Classe: collections.Counter ([iterable-or-mapping])

     A *note Counter: 1299. is a *note dict: 183. subclass for counting
     *note hashable: 825. objects.  It is a collection where elements
     are stored as dictionary keys and their counts are stored as
     dictionary values.  Counts are allowed to be any integer value
     including zero or negative counts.  The *note Counter: 1299. class
     is similar to bags or multisets in other languages.

     Elements are counted from an 'iterable' or initialized from another
     'mapping' (or counter):

          >>> c = Counter()                           # a new, empty counter
          >>> c = Counter('gallahad')                 # a new counter from an iterable
          >>> c = Counter({'red': 4, 'blue': 2})      # a new counter from a mapping
          >>> c = Counter(cats=4, dogs=8)             # a new counter from keyword args

     Counter objects have a dictionary interface except that they return
     a zero count for missing items instead of raising a *note KeyError:
     5e7.:

          >>> c = Counter(['eggs', 'ham'])
          >>> c['bacon']                              # count of a missing element is zero
          0

     Setting a count to zero does not remove an element from a counter.
     Use ‘del’ to remove it entirely:

          >>> c['sausage'] = 0                        # counter entry with a zero count
          >>> del c['sausage']                        # del actually removes the entry

     Added in version 3.1.

     Cambiato nella versione 3.7: As a *note dict: 183. subclass, *note
     Counter: 1299. inherited the capability to remember insertion
     order.  Math operations on 'Counter' objects also preserve order.
     Results are ordered according to when an element is first
     encountered in the left operand and then by the order encountered
     in the right operand.

     Counter objects support additional methods beyond those available
     for all dictionaries:

      -- Metodo: elements ()

          Return an iterator over elements repeating each as many times
          as its count.  Elements are returned in the order first
          encountered.  If an element’s count is less than one, *note
          elements(): 150b. will ignore it.

               >>> c = Counter(a=4, b=2, c=0, d=-2)
               >>> sorted(c.elements())
               ['a', 'a', 'a', 'a', 'b', 'b']

      -- Metodo: most_common ([n])

          Return a list of the 'n' most common elements and their counts
          from the most common to the least.  If 'n' is omitted or
          ‘None’, *note most_common(): 150a. returns 'all' elements in
          the counter.  Elements with equal counts are ordered in the
          order first encountered:

               >>> Counter('abracadabra').most_common(3)
               [('a', 5), ('b', 2), ('r', 2)]

      -- Metodo: subtract ([iterable-or-mapping])

          Elements are subtracted from an 'iterable' or from another
          'mapping' (or counter).  Like *note dict.update(): 166c. but
          subtracts counts instead of replacing them.  Both inputs and
          outputs may be zero or negative.

               >>> c = Counter(a=4, b=2, c=0, d=-2)
               >>> d = Counter(a=1, b=2, c=3, d=4)
               >>> c.subtract(d)
               >>> c
               Counter({'a': 3, 'b': 0, 'c': -3, 'd': -6})

          Added in version 3.2.

      -- Metodo: total ()

          Compute the sum of the counts.

               >>> c = Counter(a=10, b=5, c=0)
               >>> c.total()
               15

          Added in version 3.10.

     The usual dictionary methods are available for *note Counter: 1299.
     objects except for two which work differently for counters.

      -- Metodo: fromkeys (iterable)

          This class method is not implemented for *note Counter: 1299.
          objects.

      -- Metodo: update ([iterable-or-mapping])

          Elements are counted from an 'iterable' or added-in from
          another 'mapping' (or counter).  Like *note dict.update():
          166c. but adds counts instead of replacing them.  Also, the
          'iterable' is expected to be a sequence of elements, not a
          sequence of ‘(key, value)’ pairs.

Counters support rich comparison operators for equality, subset, and
superset relationships: ‘==’, ‘!=’, ‘<’, ‘<=’, ‘>’, ‘>=’.  All of those
tests treat missing elements as having zero counts so that ‘Counter(a=1)
== Counter(a=1, b=0)’ returns true.

Cambiato nella versione 3.10: Rich comparison operations were added.

Cambiato nella versione 3.10: In equality tests, missing elements are
treated as having zero counts.  Formerly, ‘Counter(a=3)’ and
‘Counter(a=3, b=0)’ were considered distinct.

Common patterns for working with *note Counter: 1299. objects:

     c.total()                       # total of all counts
     c.clear()                       # reset all counts
     list(c)                         # list unique elements
     set(c)                          # convert to a set
     dict(c)                         # convert to a regular dictionary
     c.items()                       # access the (elem, cnt) pairs
     Counter(dict(list_of_pairs))    # convert from a list of (elem, cnt) pairs
     c.most_common()[:-n-1:-1]       # n least common elements
     +c                              # remove zero and negative counts

Several mathematical operations are provided for combining *note
Counter: 1299. objects to produce multisets (counters that have counts
greater than zero).  Addition and subtraction combine counters by adding
or subtracting the counts of corresponding elements.  Intersection and
union return the minimum and maximum of corresponding counts.  Equality
and inclusion compare corresponding counts.  Each operation can accept
inputs with signed counts, but the output will exclude results with
counts of zero or less.

     >>> c = Counter(a=3, b=1)
     >>> d = Counter(a=1, b=2)
     >>> c + d                       # add two counters together:  c[x] + d[x]
     Counter({'a': 4, 'b': 3})
     >>> c - d                       # subtract (keeping only positive counts)
     Counter({'a': 2})
     >>> c & d                       # intersection:  min(c[x], d[x])
     Counter({'a': 1, 'b': 1})
     >>> c | d                       # union:  max(c[x], d[x])
     Counter({'a': 3, 'b': 2})
     >>> c == d                      # equality:  c[x] == d[x]
     False
     >>> c <= d                      # inclusion:  c[x] <= d[x]
     False

Unary addition and subtraction are shortcuts for adding an empty counter
or subtracting from an empty counter.

     >>> c = Counter(a=2, b=-4)
     >>> +c
     Counter({'a': 2})
     >>> -c
     Counter({'b': 4})

Added in version 3.3: Added support for unary plus, unary minus, and
in-place multiset operations.

     Nota: Counters were primarily designed to work with positive
     integers to represent running counts; however, care was taken to
     not unnecessarily preclude use cases needing other types or
     negative values.  To help with those use cases, this section
     documents the minimum range and type restrictions.

        * The *note Counter: 1299. class itself is a dictionary subclass
          with no restrictions on its keys and values.  The values are
          intended to be numbers representing counts, but you 'could'
          store anything in the value field.

        * The *note most_common(): 150a. method requires only that the
          values be orderable.

        * For in-place operations such as ‘c[key] += 1’, the value type
          need only support addition and subtraction.  So fractions,
          floats, and decimals would work and negative values are
          supported.  The same is also true for *note update(): 1764.
          and *note subtract(): 13e6. which allow negative and zero
          values for both inputs and outputs.

        * The multiset methods are designed only for use cases with
          positive values.  The inputs may be negative or zero, but only
          outputs with positive values are created.  There are no type
          restrictions, but the value type needs to support addition,
          subtraction, and comparison.

        * The *note elements(): 150b. method requires integer counts.
          It ignores zero and negative counts.

Vedi anche
..........

   * Bag class(1) in Smalltalk.

   * Wikipedia entry for Multisets(2).

   * C++ multisets(3) tutorial with examples.

   * For mathematical operations on multisets and their use cases, see
     'Knuth, Donald.  The Art of Computer Programming Volume II, Section
     4.6.3, Exercise 19'.

   * To enumerate all distinct multisets of a given size over a given
     set of elements, see *note
     itertools.combinations_with_replacement(): 1489.:

          map(Counter, combinations_with_replacement('ABC', 2)) # --> AA AB AC BB BC CC

   ---------- Footnotes ----------

   (1) 
https://www.gnu.org/software/smalltalk/manual-base/html_node/Bag.html

   (2) https://en.wikipedia.org/wiki/Multiset

   (3) 
http://www.java2s.com/Tutorial/Cpp/0380__set-multiset/Catalog0380__set-multiset.htm


File: python.info,  Node: deque objects,  Next: defaultdict objects,  Prev: Counter objects,  Up: collections — Container datatypes

5.8.4.4 ‘deque’ objects
.......................

 -- Classe: collections.deque ([iterable[, maxlen]])

     Returns a new deque object initialized left-to-right (using *note
     append(): 2960.) with data from 'iterable'.  If 'iterable' is not
     specified, the new deque is empty.

     Deques are a generalization of stacks and queues (the name is
     pronounced «deck» and is short for «double-ended queue»).  Deques
     support thread-safe, memory efficient appends and pops from either
     side of the deque with approximately the same 'O'(1) performance in
     either direction.

     Though *note list: 24d. objects support similar operations, they
     are optimized for fast fixed-length operations and incur 'O'('n')
     memory movement costs for ‘pop(0)’ and ‘insert(0, v)’ operations
     which change both the size and position of the underlying data
     representation.

     If 'maxlen' is not specified or is ‘None’, deques may grow to an
     arbitrary length.  Otherwise, the deque is bounded to the specified
     maximum length.  Once a bounded length deque is full, when new
     items are added, a corresponding number of items are discarded from
     the opposite end.  Bounded length deques provide functionality
     similar to the ‘tail’ filter in Unix.  They are also useful for
     tracking transactions and other pools of data where only the most
     recent activity is of interest.

     Deque objects support the following methods:

      -- Metodo: append (x)

          Add 'x' to the right side of the deque.

      -- Metodo: appendleft (x)

          Add 'x' to the left side of the deque.

      -- Metodo: clear ()

          Remove all elements from the deque leaving it with length 0.

      -- Metodo: copy ()

          Create a shallow copy of the deque.

          Added in version 3.5.

      -- Metodo: count (x)

          Count the number of deque elements equal to 'x'.

          Added in version 3.2.

      -- Metodo: extend (iterable)

          Extend the right side of the deque by appending elements from
          the iterable argument.

      -- Metodo: extendleft (iterable)

          Extend the left side of the deque by appending elements from
          'iterable'.  Note, the series of left appends results in
          reversing the order of elements in the iterable argument.

      -- Metodo: index (x[, start[, stop]])

          Return the position of 'x' in the deque (at or after index
          'start' and before index 'stop').  Returns the first match or
          raises *note ValueError: 2ec. if not found.

          Added in version 3.5.

      -- Metodo: insert (i, x)

          Insert 'x' into the deque at position 'i'.

          If the insertion would cause a bounded deque to grow beyond
          'maxlen', an *note IndexError: 173c. is raised.

          Added in version 3.5.

      -- Metodo: pop ()

          Remove and return an element from the right side of the deque.
          If no elements are present, raises an *note IndexError: 173c.

      -- Metodo: popleft ()

          Remove and return an element from the left side of the deque.
          If no elements are present, raises an *note IndexError: 173c.

      -- Metodo: remove (value)

          Remove the first occurrence of 'value'.  If not found, raises
          a *note ValueError: 2ec.

      -- Metodo: reverse ()

          Reverse the elements of the deque in-place and then return
          ‘None’.

          Added in version 3.2.

      -- Metodo: rotate (n=1)

          Rotate the deque 'n' steps to the right.  If 'n' is negative,
          rotate to the left.

          When the deque is not empty, rotating one step to the right is
          equivalent to ‘d.appendleft(d.pop())’, and rotating one step
          to the left is equivalent to ‘d.append(d.popleft())’.

     Deque objects also provide one read-only attribute:

      -- Attributo: maxlen

          Maximum size of a deque or ‘None’ if unbounded.

          Added in version 3.1.

In addition to the above, deques support iteration, pickling, ‘len(d)’,
‘reversed(d)’, ‘copy.copy(d)’, ‘copy.deepcopy(d)’, membership testing
with the *note in: 34b. operator, and subscript references such as
‘d[0]’ to access the first element.  Indexed access is 'O'(1) at both
ends but slows to 'O'('n') in the middle.  For fast random access, use
lists instead.

Starting in version 3.5, deques support ‘__add__()’, ‘__mul__()’, and
‘__imul__()’.

Example:

     >>> from collections import deque
     >>> d = deque('ghi')                 # make a new deque with three items
     >>> for elem in d:                   # iterate over the deque's elements
     ...     print(elem.upper())
     G
     H
     I

     >>> d.append('j')                    # add a new entry to the right side
     >>> d.appendleft('f')                # add a new entry to the left side
     >>> d                                # show the representation of the deque
     deque(['f', 'g', 'h', 'i', 'j'])

     >>> d.pop()                          # return and remove the rightmost item
     'j'
     >>> d.popleft()                      # return and remove the leftmost item
     'f'
     >>> list(d)                          # list the contents of the deque
     ['g', 'h', 'i']
     >>> d[0]                             # peek at leftmost item
     'g'
     >>> d[-1]                            # peek at rightmost item
     'i'

     >>> list(reversed(d))                # list the contents of a deque in reverse
     ['i', 'h', 'g']
     >>> 'h' in d                         # search the deque
     True
     >>> d.extend('jkl')                  # add multiple elements at once
     >>> d
     deque(['g', 'h', 'i', 'j', 'k', 'l'])
     >>> d.rotate(1)                      # right rotation
     >>> d
     deque(['l', 'g', 'h', 'i', 'j', 'k'])
     >>> d.rotate(-1)                     # left rotation
     >>> d
     deque(['g', 'h', 'i', 'j', 'k', 'l'])

     >>> deque(reversed(d))               # make a new deque in reverse order
     deque(['l', 'k', 'j', 'i', 'h', 'g'])
     >>> d.clear()                        # empty the deque
     >>> d.pop()                          # cannot pop from an empty deque
     Traceback (most recent call last):
         File "<pyshell#6>", line 1, in -toplevel-
             d.pop()
     IndexError: pop from an empty deque

     >>> d.extendleft('abc')              # extendleft() reverses the input order
     >>> d
     deque(['c', 'b', 'a'])

* Menu:

* deque Recipes::


File: python.info,  Node: deque Recipes,  Up: deque objects

5.8.4.5 ‘deque’ Recipes
.......................

This section shows various approaches to working with deques.

Bounded length deques provide functionality similar to the ‘tail’ filter
in Unix:

     def tail(filename, n=10):
         'Return the last n lines of a file'
         with open(filename) as f:
             return deque(f, n)

Another approach to using deques is to maintain a sequence of recently
added elements by appending to the right and popping to the left:

     def moving_average(iterable, n=3):
         # moving_average([40, 30, 50, 46, 39, 44]) --> 40.0 42.0 45.0 43.0
         # https://en.wikipedia.org/wiki/Moving_average
         it = iter(iterable)
         d = deque(itertools.islice(it, n-1))
         d.appendleft(0)
         s = sum(d)
         for elem in it:
             s += elem - d.popleft()
             d.append(elem)
             yield s / n

A round-robin scheduler(1) can be implemented with input iterators
stored in a *note deque: 7f5.  Values are yielded from the active
iterator in position zero.  If that iterator is exhausted, it can be
removed with *note popleft(): 2966.; otherwise, it can be cycled back to
the end with the *note rotate(): 1c78. method:

     def roundrobin(*iterables):
         "roundrobin('ABC', 'D', 'EF') --> A D E B F C"
         iterators = deque(map(iter, iterables))
         while iterators:
             try:
                 while True:
                     yield next(iterators[0])
                     iterators.rotate(-1)
             except StopIteration:
                 # Remove an exhausted iterator.
                 iterators.popleft()

The *note rotate(): 1c78. method provides a way to implement *note
deque: 7f5. slicing and deletion.  For example, a pure Python
implementation of ‘del d[n]’ relies on the ‘rotate()’ method to position
elements to be popped:

     def delete_nth(d, n):
         d.rotate(-n)
         d.popleft()
         d.rotate(n)

To implement *note deque: 7f5. slicing, use a similar approach applying
*note rotate(): 1c78. to bring a target element to the left side of the
deque.  Remove old entries with *note popleft(): 2966, add new entries
with *note extend(): 2963, and then reverse the rotation.  With minor
variations on that approach, it is easy to implement Forth style stack
manipulations such as ‘dup’, ‘drop’, ‘swap’, ‘over’, ‘pick’, ‘rot’, and
‘roll’.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Round-robin_scheduling


File: python.info,  Node: defaultdict objects,  Next: namedtuple Factory Function for Tuples with Named Fields,  Prev: deque objects,  Up: collections — Container datatypes

5.8.4.6 ‘defaultdict’ objects
.............................

 -- Classe: collections.defaultdict (default_factory=None, /[, ...])

     Return a new dictionary-like object.  *note defaultdict: 13c4. is a
     subclass of the built-in *note dict: 183. class.  It overrides one
     method and adds one writable instance variable.  The remaining
     functionality is the same as for the *note dict: 183. class and is
     not documented here.

     The first argument provides the initial value for the *note
     default_factory: 2969. attribute; it defaults to ‘None’.  All
     remaining arguments are treated the same as if they were passed to
     the *note dict: 183. constructor, including keyword arguments.

     *note defaultdict: 13c4. objects support the following method in
     addition to the standard *note dict: 183. operations:

      -- Metodo: __missing__ (key)

          If the *note default_factory: 2969. attribute is ‘None’, this
          raises a *note KeyError: 5e7. exception with the 'key' as
          argument.

          If *note default_factory: 2969. is not ‘None’, it is called
          without arguments to provide a default value for the given
          'key', this value is inserted in the dictionary for the 'key',
          and returned.

          If calling *note default_factory: 2969. raises an exception
          this exception is propagated unchanged.

          This method is called by the *note __getitem__(): 588. method
          of the *note dict: 183. class when the requested key is not
          found; whatever it returns or raises is then returned or
          raised by *note __getitem__(): 588.

          Note that *note __missing__(): 296a. is 'not' called for any
          operations besides *note __getitem__(): 588.  This means that
          *note get(): 201e. will, like normal dictionaries, return
          ‘None’ as a default rather than using *note default_factory:
          2969.

     *note defaultdict: 13c4. objects support the following instance
     variable:

      -- Attributo: default_factory

          This attribute is used by the *note __missing__(): 296a.
          method; it is initialized from the first argument to the
          constructor, if present, or to ‘None’, if absent.

     Cambiato nella versione 3.9: Added merge (‘|’) and update (‘|=’)
     operators, specified in PEP 584(1).

* Menu:

* defaultdict Examples::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0584/


File: python.info,  Node: defaultdict Examples,  Up: defaultdict objects

5.8.4.7 ‘defaultdict’ Examples
..............................

Using *note list: 24d. as the *note default_factory: 2969, it is easy to
group a sequence of key-value pairs into a dictionary of lists:

     >>> s = [('yellow', 1), ('blue', 2), ('yellow', 3), ('blue', 4), ('red', 1)]
     >>> d = defaultdict(list)
     >>> for k, v in s:
     ...     d[k].append(v)
     ...
     >>> sorted(d.items())
     [('blue', [2, 4]), ('red', [1]), ('yellow', [1, 3])]

When each key is encountered for the first time, it is not already in
the mapping; so an entry is automatically created using the *note
default_factory: 2969. function which returns an empty *note list: 24d.
The *note list.append(): 8dd. operation then attaches the value to the
new list.  When keys are encountered again, the look-up proceeds
normally (returning the list for that key) and the *note list.append():
8dd. operation adds another value to the list.  This technique is
simpler and faster than an equivalent technique using *note
dict.setdefault(): 127b.:

     >>> d = {}
     >>> for k, v in s:
     ...     d.setdefault(k, []).append(v)
     ...
     >>> sorted(d.items())
     [('blue', [2, 4]), ('red', [1]), ('yellow', [1, 3])]

Setting the *note default_factory: 2969. to *note int: 19b. makes the
*note defaultdict: 13c4. useful for counting (like a bag or multiset in
other languages):

     >>> s = 'mississippi'
     >>> d = defaultdict(int)
     >>> for k in s:
     ...     d[k] += 1
     ...
     >>> sorted(d.items())
     [('i', 4), ('m', 1), ('p', 2), ('s', 4)]

When a letter is first encountered, it is missing from the mapping, so
the *note default_factory: 2969. function calls *note int(): 19b. to
supply a default count of zero.  The increment operation then builds up
the count for each letter.

The function *note int(): 19b. which always returns zero is just a
special case of constant functions.  A faster and more flexible way to
create constant functions is to use a lambda function which can supply
any constant value (not just zero):

     >>> def constant_factory(value):
     ...     return lambda: value
     ...
     >>> d = defaultdict(constant_factory('<missing>'))
     >>> d.update(name='John', action='ran')
     >>> '%(name)s %(action)s to %(object)s' % d
     'John ran to <missing>'

Setting the *note default_factory: 2969. to *note set: 184. makes the
*note defaultdict: 13c4. useful for building a dictionary of sets:

     >>> s = [('red', 1), ('blue', 2), ('red', 3), ('blue', 4), ('red', 1), ('blue', 4)]
     >>> d = defaultdict(set)
     >>> for k, v in s:
     ...     d[k].add(v)
     ...
     >>> sorted(d.items())
     [('blue', {2, 4}), ('red', {1, 3})]


File: python.info,  Node: namedtuple Factory Function for Tuples with Named Fields,  Next: OrderedDict objects,  Prev: defaultdict objects,  Up: collections — Container datatypes

5.8.4.8 ‘namedtuple()’ Factory Function for Tuples with Named Fields
....................................................................

Named tuples assign meaning to each position in a tuple and allow for
more readable, self-documenting code.  They can be used wherever regular
tuples are used, and they add the ability to access fields by name
instead of position index.

 -- Funzione: collections.namedtuple (typename, field_names, *,
          rename=False, defaults=None, module=None)

     Returns a new tuple subclass named 'typename'.  The new subclass is
     used to create tuple-like objects that have fields accessible by
     attribute lookup as well as being indexable and iterable.
     Instances of the subclass also have a helpful docstring (with
     'typename' and 'field_names') and a helpful *note __repr__(): 830.
     method which lists the tuple contents in a ‘name=value’ format.

     The 'field_names' are a sequence of strings such as ‘['x', 'y']’.
     Alternatively, 'field_names' can be a single string with each
     fieldname separated by whitespace and/or commas, for example ‘'x
     y'’ or ‘'x, y'’.

     Any valid Python identifier may be used for a fieldname except for
     names starting with an underscore.  Valid identifiers consist of
     letters, digits, and underscores but do not start with a digit or
     underscore and cannot be a *note keyword: 88. such as 'class',
     'for', 'return', 'global', 'pass', or 'raise'.

     If 'rename' is true, invalid fieldnames are automatically replaced
     with positional names.  For example, ‘['abc', 'def', 'ghi', 'abc']’
     is converted to ‘['abc', '_1', 'ghi', '_3']’, eliminating the
     keyword ‘def’ and the duplicate fieldname ‘abc’.

     'defaults' can be ‘None’ or an *note iterable: 142f. of default
     values.  Since fields with a default value must come after any
     fields without a default, the 'defaults' are applied to the
     rightmost parameters.  For example, if the fieldnames are ‘['x',
     'y', 'z']’ and the defaults are ‘(1, 2)’, then ‘x’ will be a
     required argument, ‘y’ will default to ‘1’, and ‘z’ will default to
     ‘2’.

     If 'module' is defined, the *note __module__: 617. attribute of the
     named tuple is set to that value.

     Named tuple instances do not have per-instance dictionaries, so
     they are lightweight and require no more memory than regular
     tuples.

     To support pickling, the named tuple class should be assigned to a
     variable that matches 'typename'.

     Cambiato nella versione 3.1: Added support for 'rename'.

     Cambiato nella versione 3.6: The 'verbose' and 'rename' parameters
     became *note keyword-only arguments: 5a5.

     Cambiato nella versione 3.6: Added the 'module' parameter.

     Cambiato nella versione 3.7: Removed the 'verbose' parameter and
     the ‘_source’ attribute.

     Cambiato nella versione 3.7: Added the 'defaults' parameter and the
     *note _field_defaults: 296d. attribute.

     >>> # Basic example
     >>> Point = namedtuple('Point', ['x', 'y'])
     >>> p = Point(11, y=22)     # instantiate with positional or keyword arguments
     >>> p[0] + p[1]             # indexable like the plain tuple (11, 22)
     33
     >>> x, y = p                # unpack like a regular tuple
     >>> x, y
     (11, 22)
     >>> p.x + p.y               # fields also accessible by name
     33
     >>> p                       # readable __repr__ with a name=value style
     Point(x=11, y=22)

Named tuples are especially useful for assigning field names to result
tuples returned by the *note csv: 2d. or *note sqlite3: d4. modules:

     EmployeeRecord = namedtuple('EmployeeRecord', 'name, age, title, department, paygrade')

     import csv
     for emp in map(EmployeeRecord._make, csv.reader(open("employees.csv", "rb"))):
         print(emp.name, emp.title)

     import sqlite3
     conn = sqlite3.connect('/companydata')
     cursor = conn.cursor()
     cursor.execute('SELECT name, age, title, department, paygrade FROM employees')
     for emp in map(EmployeeRecord._make, cursor.fetchall()):
         print(emp.name, emp.title)

In addition to the methods inherited from tuples, named tuples support
three additional methods and two attributes.  To prevent conflicts with
field names, the method and attribute names start with an underscore.

 -- Metodo: classmethod somenamedtuple._make (iterable)

     Class method that makes a new instance from an existing sequence or
     iterable.

          >>> t = [11, 22]
          >>> Point._make(t)
          Point(x=11, y=22)

 -- Metodo: somenamedtuple._asdict ()

     Return a new *note dict: 183. which maps field names to their
     corresponding values:

          >>> p = Point(x=11, y=22)
          >>> p._asdict()
          {'x': 11, 'y': 22}

     Cambiato nella versione 3.1: Returns an *note OrderedDict: 7f4.
     instead of a regular *note dict: 183.

     Cambiato nella versione 3.8: Returns a regular *note dict: 183.
     instead of an *note OrderedDict: 7f4.  As of Python 3.7, regular
     dicts are guaranteed to be ordered.  If the extra features of *note
     OrderedDict: 7f4. are required, the suggested remediation is to
     cast the result to the desired type: ‘OrderedDict(nt._asdict())’.

 -- Metodo: somenamedtuple._replace (**kwargs)

     Return a new instance of the named tuple replacing specified fields
     with new values:

          >>> p = Point(x=11, y=22)
          >>> p._replace(x=33)
          Point(x=33, y=22)

          >>> for partnum, record in inventory.items():
          ...     inventory[partnum] = record._replace(price=newprices[partnum], timestamp=time.now())

     Named tuples are also supported by generic function *note
     copy.replace(): 1c0.

     Cambiato nella versione 3.13: Raise *note TypeError: 198. instead
     of *note ValueError: 2ec. for invalid keyword arguments.

 -- Attributo: somenamedtuple._fields

     Tuple of strings listing the field names.  Useful for introspection
     and for creating new named tuple types from existing named tuples.

          >>> p._fields            # view the field names
          ('x', 'y')

          >>> Color = namedtuple('Color', 'red green blue')
          >>> Pixel = namedtuple('Pixel', Point._fields + Color._fields)
          >>> Pixel(11, 22, 128, 255, 0)
          Pixel(x=11, y=22, red=128, green=255, blue=0)

 -- Attributo: somenamedtuple._field_defaults

     Dictionary mapping field names to default values.

          >>> Account = namedtuple('Account', ['type', 'balance'], defaults=[0])
          >>> Account._field_defaults
          {'balance': 0}
          >>> Account('premium')
          Account(type='premium', balance=0)

To retrieve a field whose name is stored in a string, use the *note
getattr(): dcc. function:

     >>> getattr(p, 'x')
     11

To convert a dictionary to a named tuple, use the double-star-operator
(as described in *note Spacchettamento delle Liste di Argomenti: 1ffb.):

     >>> d = {'x': 11, 'y': 22}
     >>> Point(**d)
     Point(x=11, y=22)

Since a named tuple is a regular Python class, it is easy to add or
change functionality with a subclass.  Here is how to add a calculated
field and a fixed-width print format:

     >>> class Point(namedtuple('Point', ['x', 'y'])):
     ...     __slots__ = ()
     ...     @property
     ...     def hypot(self):
     ...         return (self.x ** 2 + self.y ** 2) ** 0.5
     ...     def __str__(self):
     ...         return 'Point: x=%6.3f  y=%6.3f  hypot=%6.3f' % (self.x, self.y, self.hypot)

     >>> for p in Point(3, 4), Point(14, 5/7):
     ...     print(p)
     Point: x= 3.000  y= 4.000  hypot= 5.000
     Point: x=14.000  y= 0.714  hypot=14.018

The subclass shown above sets ‘__slots__’ to an empty tuple.  This helps
keep memory requirements low by preventing the creation of instance
dictionaries.

Subclassing is not useful for adding new, stored fields.  Instead,
simply create a new named tuple type from the *note _fields: 2970.
attribute:

     >>> Point3D = namedtuple('Point3D', Point._fields + ('z',))

Docstrings can be customized by making direct assignments to the
‘__doc__’ fields:

     >>> Book = namedtuple('Book', ['id', 'title', 'authors'])
     >>> Book.__doc__ += ': Hardcover book in active collection'
     >>> Book.id.__doc__ = '13-digit ISBN'
     >>> Book.title.__doc__ = 'Title of first printing'
     >>> Book.authors.__doc__ = 'List of authors sorted by last name'

Cambiato nella versione 3.5: Property docstrings became writeable.

Vedi anche
..........

   * See *note typing.NamedTuple: 331. for a way to add type hints for
     named tuples.  It also provides an elegant notation using the *note
     class: 14df. keyword:

          class Component(NamedTuple):
              part_number: int
              weight: float
              description: Optional[str] = None

   * See *note types.SimpleNamespace(): 4e6. for a mutable namespace
     based on an underlying dictionary instead of a tuple.

   * The *note dataclasses: 33. module provides a decorator and
     functions for automatically adding generated special methods to
     user-defined classes.


File: python.info,  Node: OrderedDict objects,  Next: UserDict objects,  Prev: namedtuple Factory Function for Tuples with Named Fields,  Up: collections — Container datatypes

5.8.4.9 ‘OrderedDict’ objects
.............................

Ordered dictionaries are just like regular dictionaries but have some
extra capabilities relating to ordering operations.  They have become
less important now that the built-in *note dict: 183. class gained the
ability to remember insertion order (this new behavior became guaranteed
in Python 3.7).

Some differences from *note dict: 183. still remain:

   * The regular *note dict: 183. was designed to be very good at
     mapping operations.  Tracking insertion order was secondary.

   * The *note OrderedDict: 7f4. was designed to be good at reordering
     operations.  Space efficiency, iteration speed, and the performance
     of update operations were secondary.

   * The *note OrderedDict: 7f4. algorithm can handle frequent
     reordering operations better than *note dict: 183.  As shown in the
     recipes below, this makes it suitable for implementing various
     kinds of LRU caches.

   * The equality operation for *note OrderedDict: 7f4. checks for
     matching order.

     A regular *note dict: 183. can emulate the order sensitive equality
     test with ‘p == q and all(k1 == k2 for k1, k2 in zip(p, q))’.

   * The *note popitem(): 14f5. method of *note OrderedDict: 7f4. has a
     different signature.  It accepts an optional argument to specify
     which item is popped.

     A regular *note dict: 183. can emulate OrderedDict’s
     ‘od.popitem(last=True)’ with ‘d.popitem()’ which is guaranteed to
     pop the rightmost (last) item.

     A regular *note dict: 183. can emulate OrderedDict’s
     ‘od.popitem(last=False)’ with ‘(k := next(iter(d)), d.pop(k))’
     which will return and remove the leftmost (first) item if it
     exists.

   * *note OrderedDict: 7f4. has a *note move_to_end(): 13e7. method to
     efficiently reposition an element to an endpoint.

     A regular *note dict: 183. can emulate OrderedDict’s
     ‘od.move_to_end(k, last=True)’ with ‘d[k] = d.pop(k)’ which will
     move the key and its associated value to the rightmost (last)
     position.

     A regular *note dict: 183. does not have an efficient equivalent
     for OrderedDict’s ‘od.move_to_end(k, last=False)’ which moves the
     key and its associated value to the leftmost (first) position.

   * Until Python 3.8, *note dict: 183. lacked a *note __reversed__():
     e88. method.

 -- Classe: collections.OrderedDict ([items])

     Return an instance of a *note dict: 183. subclass that has methods
     specialized for rearranging dictionary order.

     Added in version 3.1.

      -- Metodo: popitem (last=True)

          The *note popitem(): 14f5. method for ordered dictionaries
          returns and removes a (key, value) pair.  The pairs are
          returned in LIFO order if 'last' is true or FIFO (first-in,
          first-out) order if false.

      -- Metodo: move_to_end (key, last=True)

          Move an existing 'key' to either end of an ordered dictionary.
          The item is moved to the right end if 'last' is true (the
          default) or to the beginning if 'last' is false.  Raises *note
          KeyError: 5e7. if the 'key' does not exist:

               >>> d = OrderedDict.fromkeys('abcde')
               >>> d.move_to_end('b')
               >>> ''.join(d)
               'acdeb'
               >>> d.move_to_end('b', last=False)
               >>> ''.join(d)
               'bacde'

          Added in version 3.2.

In addition to the usual mapping methods, ordered dictionaries also
support reverse iteration using *note reversed(): a67.  Equality tests
between *note OrderedDict: 7f4. objects are order-sensitive and are
roughly equivalent to ‘list(od1.items())==list(od2.items())’.

Equality tests between *note OrderedDict: 7f4. objects and other *note
Mapping: ac9. objects are order-insensitive like regular dictionaries.
This allows *note OrderedDict: 7f4. objects to be substituted anywhere a
regular dictionary is used.

Cambiato nella versione 3.5: The items, keys, and values *note views:
2972. of *note OrderedDict: 7f4. now support reverse iteration using
*note reversed(): a67.

Cambiato nella versione 3.6: With the acceptance of PEP 468(1), order is
retained for keyword arguments passed to the *note OrderedDict: 7f4.
constructor and its *note update(): 166c. method.

Cambiato nella versione 3.9: Added merge (‘|’) and update (‘|=’)
operators, specified in PEP 584(2).

* Menu:

* OrderedDict Examples and Recipes::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0468/

   (2) https://peps.python.org/pep-0584/


File: python.info,  Node: OrderedDict Examples and Recipes,  Up: OrderedDict objects

5.8.4.10 ‘OrderedDict’ Examples and Recipes
...........................................

It is straightforward to create an ordered dictionary variant that
remembers the order the keys were 'last' inserted.  If a new entry
overwrites an existing entry, the original insertion position is changed
and moved to the end:

     class LastUpdatedOrderedDict(OrderedDict):
         'Store items in the order the keys were last added'

         def __setitem__(self, key, value):
             super().__setitem__(key, value)
             self.move_to_end(key)

An *note OrderedDict: 7f4. would also be useful for implementing
variants of *note functools.lru_cache(): be4.:

     from collections import OrderedDict
     from time import time

     class TimeBoundedLRU:
         "LRU Cache that invalidates and refreshes old entries."

         def __init__(self, func, maxsize=128, maxage=30):
             self.cache = OrderedDict()      # { args : (timestamp, result)}
             self.func = func
             self.maxsize = maxsize
             self.maxage = maxage

         def __call__(self, *args):
             if args in self.cache:
                 self.cache.move_to_end(args)
                 timestamp, result = self.cache[args]
                 if time() - timestamp <= self.maxage:
                     return result
             result = self.func(*args)
             self.cache[args] = time(), result
             if len(self.cache) > self.maxsize:
                 self.cache.popitem(last=False)
             return result

     class MultiHitLRUCache:
         """ LRU cache that defers caching a result until
             it has been requested multiple times.

             To avoid flushing the LRU cache with one-time requests,
             we don't cache until a request has been made more than once.

         """

         def __init__(self, func, maxsize=128, maxrequests=4096, cache_after=1):
             self.requests = OrderedDict()   # { uncached_key : request_count }
             self.cache = OrderedDict()      # { cached_key : function_result }
             self.func = func
             self.maxrequests = maxrequests  # max number of uncached requests
             self.maxsize = maxsize          # max number of stored return values
             self.cache_after = cache_after

         def __call__(self, *args):
             if args in self.cache:
                 self.cache.move_to_end(args)
                 return self.cache[args]
             result = self.func(*args)
             self.requests[args] = self.requests.get(args, 0) + 1
             if self.requests[args] <= self.cache_after:
                 self.requests.move_to_end(args)
                 if len(self.requests) > self.maxrequests:
                     self.requests.popitem(last=False)
             else:
                 self.requests.pop(args, None)
                 self.cache[args] = result
                 if len(self.cache) > self.maxsize:
                     self.cache.popitem(last=False)
             return result


File: python.info,  Node: UserDict objects,  Next: UserList objects,  Prev: OrderedDict objects,  Up: collections — Container datatypes

5.8.4.11 ‘UserDict’ objects
...........................

The class, *note UserDict: 1d65. acts as a wrapper around dictionary
objects.  The need for this class has been partially supplanted by the
ability to subclass directly from *note dict: 183.; however, this class
can be easier to work with because the underlying dictionary is
accessible as an attribute.

 -- Classe: collections.UserDict ([initialdata])

     Class that simulates a dictionary.  The instance’s contents are
     kept in a regular dictionary, which is accessible via the *note
     data: 2975. attribute of *note UserDict: 1d65. instances.  If
     'initialdata' is provided, *note data: 2975. is initialized with
     its contents; note that a reference to 'initialdata' will not be
     kept, allowing it to be used for other purposes.

     In addition to supporting the methods and operations of mappings,
     *note UserDict: 1d65. instances provide the following attribute:

      -- Attributo: data

          A real dictionary used to store the contents of the *note
          UserDict: 1d65. class.


File: python.info,  Node: UserList objects,  Next: UserString objects,  Prev: UserDict objects,  Up: collections — Container datatypes

5.8.4.12 ‘UserList’ objects
...........................

This class acts as a wrapper around list objects.  It is a useful base
class for your own list-like classes which can inherit from them and
override existing methods or add new ones.  In this way, one can add new
behaviors to lists.

The need for this class has been partially supplanted by the ability to
subclass directly from *note list: 24d.; however, this class can be
easier to work with because the underlying list is accessible as an
attribute.

 -- Classe: collections.UserList ([list])

     Class that simulates a list.  The instance’s contents are kept in a
     regular list, which is accessible via the *note data: 2977.
     attribute of *note UserList: 16eb. instances.  The instance’s
     contents are initially set to a copy of 'list', defaulting to the
     empty list ‘[]’.  'list' can be any iterable, for example a real
     Python list or a *note UserList: 16eb. object.

     In addition to supporting the methods and operations of mutable
     sequences, *note UserList: 16eb. instances provide the following
     attribute:

      -- Attributo: data

          A real *note list: 24d. object used to store the contents of
          the *note UserList: 16eb. class.

'Subclassing requirements:' Subclasses of *note UserList: 16eb. are
expected to offer a constructor which can be called with either no
arguments or one argument.  List operations which return a new sequence
attempt to create an instance of the actual implementation class.  To do
so, it assumes that the constructor can be called with a single
parameter, which is a sequence object used as a data source.

If a derived class does not wish to comply with this requirement, all of
the special methods supported by this class will need to be overridden;
please consult the sources for information about the methods which need
to be provided in that case.


File: python.info,  Node: UserString objects,  Prev: UserList objects,  Up: collections — Container datatypes

5.8.4.13 ‘UserString’ objects
.............................

The class, *note UserString: fd5. acts as a wrapper around string
objects.  The need for this class has been partially supplanted by the
ability to subclass directly from *note str: 169.; however, this class
can be easier to work with because the underlying string is accessible
as an attribute.

 -- Classe: collections.UserString (seq)

     Class that simulates a string object.  The instance’s content is
     kept in a regular string object, which is accessible via the *note
     data: 2979. attribute of *note UserString: fd5. instances.  The
     instance’s contents are initially set to a copy of 'seq'.  The
     'seq' argument can be any object which can be converted into a
     string using the built-in *note str(): 169. function.

     In addition to supporting the methods and operations of strings,
     *note UserString: fd5. instances provide the following attribute:

      -- Attributo: data

          A real *note str: 169. object used to store the contents of
          the *note UserString: fd5. class.

     Cambiato nella versione 3.5: New methods ‘__getnewargs__’,
     ‘__rmod__’, ‘casefold’, ‘format_map’, ‘isprintable’, and
     ‘maketrans’.


File: python.info,  Node: collections abc — Abstract Base Classes for Containers,  Next: heapq — Heap queue algorithm,  Prev: collections — Container datatypes,  Up: Data Types

5.8.5 ‘collections.abc’ — Abstract Base Classes for Containers
--------------------------------------------------------------

Added in version 3.3: Formerly, this module was part of the *note
collections: 1e. module.

'Source code:' Lib/_collections_abc.py(1)

__________________________________________________________________

This module provides *note abstract base classes: 13be. that can be used
to test whether a class provides a particular interface; for example,
whether it is *note hashable: 825. or whether it is a *note mapping:
13c3.

An *note issubclass(): 9c6. or *note isinstance(): 2ad. test for an
interface works in one of three ways.

  1. A newly written class can inherit directly from one of the abstract
     base classes.  The class must supply the required abstract methods.
     The remaining mixin methods come from inheritance and can be
     overridden if desired.  Other methods may be added as needed:

          class C(Sequence):                      # Direct inheritance
              def __init__(self): ...             # Extra method not required by the ABC
              def __getitem__(self, index):  ...  # Required abstract method
              def __len__(self):  ...             # Required abstract method
              def count(self, value): ...         # Optionally override a mixin method

          >>> issubclass(C, Sequence)
          True
          >>> isinstance(C(), Sequence)
          True

  2. Existing classes and built-in classes can be registered as «virtual
     subclasses» of the ABCs.  Those classes should define the full API
     including all of the abstract methods and all of the mixin methods.
     This lets users rely on *note issubclass(): 9c6. or *note
     isinstance(): 2ad. tests to determine whether the full interface is
     supported.  The exception to this rule is for methods that are
     automatically inferred from the rest of the API:

          class D:                                 # No inheritance
              def __init__(self): ...              # Extra method not required by the ABC
              def __getitem__(self, index):  ...   # Abstract method
              def __len__(self):  ...              # Abstract method
              def count(self, value): ...          # Mixin method
              def index(self, value): ...          # Mixin method

          Sequence.register(D)                     # Register instead of inherit

          >>> issubclass(D, Sequence)
          True
          >>> isinstance(D(), Sequence)
          True

     In this example, class ‘D’ does not need to define ‘__contains__’,
     ‘__iter__’, and ‘__reversed__’ because the *note in-operator: 24ac,
     the *note iteration: 142f. logic, and the *note reversed(): a67.
     function automatically fall back to using ‘__getitem__’ and
     ‘__len__’.

  3. Some simple interfaces are directly recognizable by the presence of
     the required methods (unless those methods have been set to *note
     None: 886.):

          class E:
              def __iter__(self): ...
              def __next__(self): ...

          >>> issubclass(E, Iterable)
          True
          >>> isinstance(E(), Iterable)
          True

     Complex interfaces do not support this last technique because an
     interface is more than just the presence of method names.
     Interfaces specify semantics and relationships between methods that
     cannot be inferred solely from the presence of specific method
     names.  For example, knowing that a class supplies ‘__getitem__’,
     ‘__len__’, and ‘__iter__’ is insufficient for distinguishing a
     *note Sequence: 13cc. from a *note Mapping: ac9.

Added in version 3.9: These abstract classes now support ‘[]’.  See
*note Tipo Generic Alias: 8c2. and PEP 585(2).

* Menu:

* Collections Abstract Base Classes::
* Collections Abstract Base Classes – Detailed Descriptions::
* Examples and Recipes::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/_collections_abc.py

   (2) https://peps.python.org/pep-0585/


File: python.info,  Node: Collections Abstract Base Classes,  Next: Collections Abstract Base Classes – Detailed Descriptions,  Up: collections abc — Abstract Base Classes for Containers

5.8.5.1 Collections Abstract Base Classes
.........................................

The collections module offers the following *note ABCs: 13be.:

ABC                                Inherits from              Abstract Methods            Mixin Methods
                                                                                          
---------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          
*note Container: 2693. (1)                                    ‘__contains__’
                                                              
                                                                                          
*note Hashable: 71a. (2)                                      ‘__hash__’
                                                              
                                                                                          
*note Iterable: 2691. (3) (4)                                 ‘__iter__’
                                                              
                                                                                          
*note Iterator: 2692. (5)          *note Iterable: 2691.      ‘__next__’                  ‘__iter__’
                                                                                          
                                                                                          
*note Reversible: e87. (6)         *note Iterable: 2691.      ‘__reversed__’
                                                              
                                                                                          
*note Generator: fdd. (7)          *note Iterator: 2692.      ‘send’, ‘throw’             ‘close’, ‘__iter__’, ‘__next__’
                                                                                          
                                                                                          
*note Sized: 71b. (8)                                         ‘__len__’
                                                              
                                                                                          
*note Callable: 9ed. (9)                                      ‘__call__’
                                                              
                                                                                          
*note Collection: e86. (10)        *note Sized: 71b,          ‘__contains__’,
                                   *note Iterable: 2691,      ‘__iter__’, ‘__len__’
                                   *note Container: 2693.     
                                   
                                                                                          
*note Sequence: 13cc.              *note Reversible: e87,     ‘__getitem__’, ‘__len__’    ‘__contains__’, ‘__iter__’, ‘__reversed__’, ‘index’,
                                   *note Collection: e86.                                 and ‘count’
                                                                                          
                                                                                          
*note MutableSequence: 4c0.        *note Sequence: 13cc.      ‘__getitem__’,              Inherited *note Sequence: 13cc. methods and ‘append’,
                                                              ‘__setitem__’,              ‘clear’, ‘reverse’, ‘extend’, ‘pop’, ‘remove’, and
                                                              ‘__delitem__’, ‘__len__’,   ‘__iadd__’
                                                              ‘insert’                    
                                                              
                                                                                          
*note ByteString: 342.             *note Sequence: 13cc.      ‘__getitem__’, ‘__len__’    Inherited *note Sequence: 13cc. methods
                                                                                          
                                                                                          
*note Set: 2689.                   *note Collection: e86.     ‘__contains__’,             ‘__le__’, ‘__lt__’, ‘__eq__’, ‘__ne__’, ‘__gt__’,
                                                              ‘__iter__’, ‘__len__’       ‘__ge__’, ‘__and__’, ‘__or__’, ‘__sub__’, ‘__rsub__’,
                                                                                          ‘__xor__’, ‘__rxor__’ and ‘isdisjoint’
                                                                                          
                                                                                          
*note MutableSet: 2694.            *note Set: 2689.           ‘__contains__’,             Inherited *note Set: 2689. methods and ‘clear’, ‘pop’,
                                                              ‘__iter__’, ‘__len__’,      ‘remove’, ‘__ior__’, ‘__iand__’, ‘__ixor__’, and
                                                              ‘add’, ‘discard’            ‘__isub__’
                                                                                          
                                                                                          
*note Mapping: ac9.                *note Collection: e86.     ‘__getitem__’,              ‘__contains__’, ‘keys’, ‘items’, ‘values’, ‘get’,
                                                              ‘__iter__’, ‘__len__’       ‘__eq__’, and ‘__ne__’
                                                                                          
                                                                                          
*note MutableMapping: 12b4.        *note Mapping: ac9.        ‘__getitem__’,              Inherited *note Mapping: ac9. methods and ‘pop’,
                                                              ‘__setitem__’,              ‘popitem’, ‘clear’, ‘update’, and ‘setdefault’
                                                              ‘__delitem__’,              
                                                              ‘__iter__’, ‘__len__’
                                                              
                                                                                          
*note MappingView: 2695.           *note Sized: 71b.                                      ‘__init__’, ‘__len__’ and ‘__repr__’
                                                                                          
                                                                                          
*note ItemsView: 2697.             *note MappingView: 2695,                               ‘__contains__’, ‘__iter__’
                                   *note Set: 2689.                                       
                                   
                                                                                          
*note KeysView: 2696.              *note MappingView: 2695,                               ‘__contains__’, ‘__iter__’
                                   *note Set: 2689.                                       
                                   
                                                                                          
*note ValuesView: 2698.            *note MappingView: 2695,                               ‘__contains__’, ‘__iter__’
                                   *note Collection: e86.                                 
                                   
                                                                                          
*note Awaitable: fde. (11)                                    ‘__await__’
                                                              
                                                                                          
*note Coroutine: fdf. (12)         *note Awaitable: fde.      ‘send’, ‘throw’             ‘close’
                                                                                          
                                                                                          
*note AsyncIterable: fe1. (13)                                ‘__aiter__’
                                                              
                                                                                          
*note AsyncIterator: fe0. (14)     *note AsyncIterable: fe1.  ‘__anext__’                 ‘__aiter__’
                                                                                          
                                                                                          
*note AsyncGenerator: e89. (15)    *note AsyncIterator: fe0.  ‘asend’, ‘athrow’           ‘aclose’, ‘__aiter__’, ‘__anext__’
                                                                                          
                                                                                          
*note Buffer: 343. (16)                                       ‘__buffer__’
                                                              

   ---------- Footnotes ----------

   (1) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (2) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (3) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (4) Checking ‘isinstance(obj, Iterable)’ detects classes that are
registered as *note Iterable: 2691. or that have an *note __iter__():
2094. method, but it does not detect classes that iterate with the *note
__getitem__(): 588. method.  The only reliable way to determine whether
an object is *note iterable: 142f. is to call ‘iter(obj)’.

   (5) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (6) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (7) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (8) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (9) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (10) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (11) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (12) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (13) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (14) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (15) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.

   (16) These ABCs override *note __subclasshook__(): 297e. to support
testing an interface by verifying the required methods are present and
have not been set to *note None: 886.  This only works for simple
interfaces.  More complex interfaces require registration or direct
subclassing.


File: python.info,  Node: Collections Abstract Base Classes – Detailed Descriptions,  Next: Examples and Recipes,  Prev: Collections Abstract Base Classes,  Up: collections abc — Abstract Base Classes for Containers

5.8.5.2 Collections Abstract Base Classes – Detailed Descriptions
.................................................................

 -- Classe: collections.abc.Container

     ABC for classes that provide the *note __contains__(): 15c1.
     method.

 -- Classe: collections.abc.Hashable

     ABC for classes that provide the *note __hash__(): cf5. method.

 -- Classe: collections.abc.Sized

     ABC for classes that provide the *note __len__(): 1777. method.

 -- Classe: collections.abc.Callable

     ABC for classes that provide the *note __call__(): 77b. method.

     See *note Annotating callable objects: 26b2. for details on how to
     use ‘Callable’ in type annotations.

 -- Classe: collections.abc.Iterable

     ABC for classes that provide the *note __iter__(): 2094. method.

     Checking ‘isinstance(obj, Iterable)’ detects classes that are
     registered as *note Iterable: 2691. or that have an *note
     __iter__(): 2094. method, but it does not detect classes that
     iterate with the *note __getitem__(): 588. method.  The only
     reliable way to determine whether an object is *note iterable:
     142f. is to call ‘iter(obj)’.

 -- Classe: collections.abc.Collection

     ABC for sized iterable container classes.

     Added in version 3.6.

 -- Classe: collections.abc.Iterator

     ABC for classes that provide the *note __iter__(): 2097. and *note
     __next__(): 14d5. methods.  See also the definition of *note
     iterator: 4c9.

 -- Classe: collections.abc.Reversible

     ABC for iterable classes that also provide the *note
     __reversed__(): e88. method.

     Added in version 3.6.

 -- Classe: collections.abc.Generator

     ABC for *note generator: 1263. classes that implement the protocol
     defined in PEP 342(1) that extends *note iterators: 4c9. with the
     *note send(): 23fd, *note throw(): 71d. and *note close(): 177b.
     methods.

     See *note Annotating generators and coroutines: 2980. for details
     on using ‘Generator’ in type annotations.

     Added in version 3.5.

 -- Classe: collections.abc.Sequence
 -- Classe: collections.abc.MutableSequence
 -- Classe: collections.abc.ByteString

     ABCs for read-only and mutable *note sequences: 717.

     Implementation note: Some of the mixin methods, such as *note
     __iter__(): 2094, *note __reversed__(): e88, and *note index():
     1961. make repeated calls to the underlying *note __getitem__():
     588. method.  Consequently, if *note __getitem__(): 588. is
     implemented with constant access speed, the mixin methods will have
     linear performance; however, if the underlying method is linear (as
     it would be with a linked list), the mixins will have quadratic
     performance and will likely need to be overridden.

      -- Metodo: index (value, start=0, stop=None)

          Return first index of 'value'.

          Raises *note ValueError: 2ec. if the value is not present.

          Supporting the 'start' and 'stop' arguments is optional, but
          recommended.

          Cambiato nella versione 3.5: The *note index(): 1961. method
          gained support for the 'stop' and 'start' arguments.

     Deprecated since version 3.12, will be removed in version 3.17: The
     *note ByteString: 342. ABC has been deprecated.

     Use ‘isinstance(obj, collections.abc.Buffer)’ to test if ‘obj’
     implements the *note buffer protocol: 260. at runtime.  For use in
     type annotations, either use *note Buffer: 343. or a union that
     explicitly specifies the types your code supports (e.g., ‘bytes |
     bytearray | memoryview’).

     ‘ByteString’ was originally intended to be an abstract class that
     would serve as a supertype of both *note bytes: 192. and *note
     bytearray: 344.  However, since the ABC never had any methods,
     knowing that an object was an instance of ‘ByteString’ never
     actually told you anything useful about the object.  Other common
     buffer types such as *note memoryview: 165. were also never
     understood as subtypes of ‘ByteString’ (either at runtime or by
     static type checkers).

     See PEP 688(2) for more details.

 -- Classe: collections.abc.Set
 -- Classe: collections.abc.MutableSet

     ABCs for read-only and mutable *note sets: 201b.

 -- Classe: collections.abc.Mapping
 -- Classe: collections.abc.MutableMapping

     ABCs for read-only and mutable *note mappings: 13c3.

 -- Classe: collections.abc.MappingView
 -- Classe: collections.abc.ItemsView
 -- Classe: collections.abc.KeysView
 -- Classe: collections.abc.ValuesView

     ABCs for mapping, items, keys, and values *note views: 2972.

 -- Classe: collections.abc.Awaitable

     ABC for *note awaitable: 4ca. objects, which can be used in *note
     await: 18d. expressions.  Custom implementations must provide the
     *note __await__(): f77. method.

     *note Coroutine: 6ba. objects and instances of the *note Coroutine:
     fdf. ABC are all instances of this ABC.

          Nota: In CPython, generator-based coroutines (*note
          generators: 1263. decorated with *note @types.coroutine:
          108a.) are 'awaitables', even though they do not have an *note
          __await__(): f77. method.  Using ‘isinstance(gencoro,
          Awaitable)’ for them will return ‘False’.  Use *note
          inspect.isawaitable(): 101a. to detect them.

     Added in version 3.5.

 -- Classe: collections.abc.Coroutine

     ABC for *note coroutine: 6ba. compatible classes.  These implement
     the following methods, defined in *note Coroutine Objects: 233d.:
     *note send(): 23fc, *note throw(): 71c, and *note close(): 23fe.
     Custom implementations must also implement *note __await__(): f77.
     All *note Coroutine: fdf. instances are also instances of *note
     Awaitable: fde.

          Nota: In CPython, generator-based coroutines (*note
          generators: 1263. decorated with *note @types.coroutine:
          108a.) are 'awaitables', even though they do not have an *note
          __await__(): f77. method.  Using ‘isinstance(gencoro,
          Coroutine)’ for them will return ‘False’.  Use *note
          inspect.isawaitable(): 101a. to detect them.

     See *note Annotating generators and coroutines: 2980. for details
     on using ‘Coroutine’ in type annotations.  The variance and order
     of type parameters correspond to those of *note Generator: fdd.

     Added in version 3.5.

 -- Classe: collections.abc.AsyncIterable

     ABC for classes that provide an ‘__aiter__’ method.  See also the
     definition of *note asynchronous iterable: f76.

     Added in version 3.5.

 -- Classe: collections.abc.AsyncIterator

     ABC for classes that provide ‘__aiter__’ and ‘__anext__’ methods.
     See also the definition of *note asynchronous iterator: 4c8.

     Added in version 3.5.

 -- Classe: collections.abc.AsyncGenerator

     ABC for *note asynchronous generator: 2476. classes that implement
     the protocol defined in PEP 525(3) and PEP 492(4).

     See *note Annotating generators and coroutines: 2980. for details
     on using ‘AsyncGenerator’ in type annotations.

     Added in version 3.6.

 -- Classe: collections.abc.Buffer

     ABC for classes that provide the *note __buffer__(): 68d. method,
     implementing the *note buffer protocol: 260.  See PEP 688(5).

     Added in version 3.12.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0342/

   (2) https://peps.python.org/pep-0688/#current-options

   (3) https://peps.python.org/pep-0525/

   (4) https://peps.python.org/pep-0492/

   (5) https://peps.python.org/pep-0688/


File: python.info,  Node: Examples and Recipes,  Prev: Collections Abstract Base Classes – Detailed Descriptions,  Up: collections abc — Abstract Base Classes for Containers

5.8.5.3 Examples and Recipes
............................

ABCs allow us to ask classes or instances if they provide particular
functionality, for example:

     size = None
     if isinstance(myvar, collections.abc.Sized):
         size = len(myvar)

Several of the ABCs are also useful as mixins that make it easier to
develop classes supporting container APIs.  For example, to write a
class supporting the full *note Set: 2689. API, it is only necessary to
supply the three underlying abstract methods: *note __contains__():
15c1, *note __iter__(): 2094, and *note __len__(): 1777.  The ABC
supplies the remaining methods such as ‘__and__()’ and *note
isdisjoint(): 2676.:

     class ListBasedSet(collections.abc.Set):
         ''' Alternate set implementation favoring space over speed
             and not requiring the set elements to be hashable. '''
         def __init__(self, iterable):
             self.elements = lst = []
             for value in iterable:
                 if value not in lst:
                     lst.append(value)

         def __iter__(self):
             return iter(self.elements)

         def __contains__(self, value):
             return value in self.elements

         def __len__(self):
             return len(self.elements)

     s1 = ListBasedSet('abcdef')
     s2 = ListBasedSet('defghi')
     overlap = s1 & s2            # The __and__() method is supported automatically

Notes on using *note Set: 2689. and *note MutableSet: 2694. as a mixin:

  1. Since some set operations create new sets, the default mixin
     methods need a way to create new instances from an *note iterable:
     142f.  The class constructor is assumed to have a signature in the
     form ‘ClassName(iterable)’.  That assumption is factored-out to an
     internal *note classmethod: 48f. called ‘_from_iterable()’ which
     calls ‘cls(iterable)’ to produce a new set.  If the *note Set:
     2689. mixin is being used in a class with a different constructor
     signature, you will need to override ‘_from_iterable()’ with a
     classmethod or regular method that can construct new instances from
     an iterable argument.

  2. To override the comparisons (presumably for speed, as the semantics
     are fixed), redefine *note __le__(): 1512. and *note __ge__():
     1514, then the other operations will automatically follow suit.

  3. The *note Set: 2689. mixin provides a ‘_hash()’ method to compute a
     hash value for the set; however, *note __hash__(): cf5. is not
     defined because not all sets are *note hashable: 825. or immutable.
     To add set hashability using mixins, inherit from both *note Set():
     2689. and *note Hashable(): 71a, then define ‘__hash__ =
     Set._hash’.

Vedi anche
..........

   * OrderedSet recipe(1) for an example built on *note MutableSet:
     2694.

   * For more about ABCs, see the *note abc: 4. module and PEP 3119(2).

   ---------- Footnotes ----------

   (1) https://code.activestate.com/recipes/576694/

   (2) https://peps.python.org/pep-3119/


File: python.info,  Node: heapq — Heap queue algorithm,  Next: bisect — Array bisection algorithm,  Prev: collections abc — Abstract Base Classes for Containers,  Up: Data Types

5.8.6 ‘heapq’ — Heap queue algorithm
------------------------------------

'Source code:' Lib/heapq.py(1)

__________________________________________________________________

This module provides an implementation of the heap queue algorithm, also
known as the priority queue algorithm.

Min-heaps are binary trees for which every parent node has a value less
than or equal to any of its children.  We refer to this condition as the
heap invariant.

For min-heaps, this implementation uses lists for which ‘heap[k] <=
heap[2*k+1]’ and ‘heap[k] <= heap[2*k+2]’ for all 'k' for which the
compared elements exist.  Elements are counted from zero.  The
interesting property of a min-heap is that its smallest element is
always the root, ‘heap[0]’.

Max-heaps satisfy the reverse invariant: every parent node has a value
'greater' than any of its children.  These are implemented as lists for
which ‘maxheap[2*k+1] <= maxheap[k]’ and ‘maxheap[2*k+2] <= maxheap[k]’
for all 'k' for which the compared elements exist.  The root,
‘maxheap[0]’, contains the 'largest' element; ‘heap.sort(reverse=True)’
maintains the max-heap invariant.

The ‘heapq’ API differs from textbook heap algorithms in two aspects:
(a) We use zero-based indexing.  This makes the relationship between the
index for a node and the indexes for its children slightly less obvious,
but is more suitable since Python uses zero-based indexing.  (b)
Textbooks often focus on max-heaps, due to their suitability for
in-place sorting.  Our implementation favors min-heaps as they better
correspond to Python *note lists: 24d.

These two aspects make it possible to view the heap as a regular Python
list without surprises: ‘heap[0]’ is the smallest item, and
‘heap.sort()’ maintains the heap invariant!

Like *note list.sort(): dca, this implementation uses only the ‘<’
operator for comparisons, for both min-heaps and max-heaps.

In the API below, and in this documentation, the unqualified term 'heap'
generally refers to a min-heap.  The API for max-heaps is named using a
‘_max’ suffix.

To create a heap, use a list initialized as ‘[]’, or transform an
existing list into a min-heap or max-heap using the *note heapify():
2986. or *note heapify_max(): 221. functions, respectively.

The following functions are provided for min-heaps:

 -- Funzione: heapq.heapify (x)

     Transform list 'x' into a min-heap, in-place, in linear time.

 -- Funzione: heapq.heappush (heap, item)

     Push the value 'item' onto the 'heap', maintaining the min-heap
     invariant.

 -- Funzione: heapq.heappop (heap)

     Pop and return the smallest item from the 'heap', maintaining the
     min-heap invariant.  If the heap is empty, *note IndexError: 173c.
     is raised.  To access the smallest item without popping it, use
     ‘heap[0]’.

 -- Funzione: heapq.heappushpop (heap, item)

     Push 'item' on the heap, then pop and return the smallest item from
     the 'heap'.  The combined action runs more efficiently than *note
     heappush(): 16c3. followed by a separate call to *note heappop():
     16c4.

 -- Funzione: heapq.heapreplace (heap, item)

     Pop and return the smallest item from the 'heap', and also push the
     new 'item'.  The heap size doesn’t change.  If the heap is empty,
     *note IndexError: 173c. is raised.

     This one step operation is more efficient than a *note heappop():
     16c4. followed by *note heappush(): 16c3. and can be more
     appropriate when using a fixed-size heap.  The pop/push combination
     always returns an element from the heap and replaces it with
     'item'.

     The value returned may be larger than the 'item' added.  If that
     isn’t desired, consider using *note heappushpop(): 2987. instead.
     Its push/pop combination returns the smaller of the two values,
     leaving the larger value on the heap.

For max-heaps, the following functions are provided:

 -- Funzione: heapq.heapify_max (x)

     Transform list 'x' into a max-heap, in-place, in linear time.

     Added in version 3.14.

 -- Funzione: heapq.heappush_max (heap, item)

     Push the value 'item' onto the max-heap 'heap', maintaining the
     max-heap invariant.

     Added in version 3.14.

 -- Funzione: heapq.heappop_max (heap)

     Pop and return the largest item from the max-heap 'heap',
     maintaining the max-heap invariant.  If the max-heap is empty,
     *note IndexError: 173c. is raised.  To access the largest item
     without popping it, use ‘maxheap[0]’.

     Added in version 3.14.

 -- Funzione: heapq.heappushpop_max (heap, item)

     Push 'item' on the max-heap 'heap', then pop and return the largest
     item from 'heap'.  The combined action runs more efficiently than
     *note heappush_max(): 222. followed by a separate call to *note
     heappop_max(): 223.

     Added in version 3.14.

 -- Funzione: heapq.heapreplace_max (heap, item)

     Pop and return the largest item from the max-heap 'heap' and also
     push the new 'item'.  The max-heap size doesn’t change.  If the
     max-heap is empty, *note IndexError: 173c. is raised.

     The value returned may be smaller than the 'item' added.  Refer to
     the analogous function *note heapreplace(): 2988. for detailed
     usage notes.

     Added in version 3.14.

The module also offers three general purpose functions based on heaps.

 -- Funzione: heapq.merge (*iterables, key=None, reverse=False)

     Merge multiple sorted inputs into a single sorted output (for
     example, merge timestamped entries from multiple log files).
     Returns an *note iterator: 4c9. over the sorted values.

     Similar to ‘sorted(itertools.chain(*iterables))’ but returns an
     iterable, does not pull the data into memory all at once, and
     assumes that each of the input streams is already sorted (smallest
     to largest).

     Has two optional arguments which must be specified as keyword
     arguments.

     'key' specifies a *note key function: 1008. of one argument that is
     used to extract a comparison key from each input element.  The
     default value is ‘None’ (compare the elements directly).

     'reverse' is a boolean value.  If set to ‘True’, then the input
     elements are merged as if each comparison were reversed.  To
     achieve behavior similar to ‘sorted(itertools.chain(*iterables),
     reverse=True)’, all iterables must be sorted from largest to
     smallest.

     Cambiato nella versione 3.5: Added the optional 'key' and 'reverse'
     parameters.

 -- Funzione: heapq.nlargest (n, iterable, key=None)

     Return a list with the 'n' largest elements from the dataset
     defined by 'iterable'.  'key', if provided, specifies a function of
     one argument that is used to extract a comparison key from each
     element in 'iterable' (for example, ‘key=str.lower’).  Equivalent
     to: ‘sorted(iterable, key=key, reverse=True)[:n]’.

 -- Funzione: heapq.nsmallest (n, iterable, key=None)

     Return a list with the 'n' smallest elements from the dataset
     defined by 'iterable'.  'key', if provided, specifies a function of
     one argument that is used to extract a comparison key from each
     element in 'iterable' (for example, ‘key=str.lower’).  Equivalent
     to: ‘sorted(iterable, key=key)[:n]’.

The latter two functions perform best for smaller values of 'n'.  For
larger values, it is more efficient to use the *note sorted(): dc9.
function.  Also, when ‘n==1’, it is more efficient to use the built-in
*note min(): 110d. and *note max(): 110e. functions.  If repeated usage
of these functions is required, consider turning the iterable into an
actual heap.

* Menu:

* Basic Examples::
* Other Applications::
* Priority Queue Implementation Notes::
* Theory::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/heapq.py


File: python.info,  Node: Basic Examples,  Next: Other Applications,  Up: heapq — Heap queue algorithm

5.8.6.1 Basic Examples
......................

A heapsort(1) can be implemented by pushing all values onto a heap and
then popping off the smallest values one at a time:

     >>> def heapsort(iterable):
     ...     h = []
     ...     for value in iterable:
     ...         heappush(h, value)
     ...     return [heappop(h) for i in range(len(h))]
     ...
     >>> heapsort([1, 3, 5, 7, 9, 2, 4, 6, 8, 0])
     [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

This is similar to ‘sorted(iterable)’, but unlike *note sorted(): dc9,
this implementation is not stable.

Heap elements can be tuples.  This is useful for assigning comparison
values (such as task priorities) alongside the main record being
tracked:

     >>> h = []
     >>> heappush(h, (5, 'write code'))
     >>> heappush(h, (7, 'release product'))
     >>> heappush(h, (1, 'write spec'))
     >>> heappush(h, (3, 'create tests'))
     >>> heappop(h)
     (1, 'write spec')

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Heapsort


File: python.info,  Node: Other Applications,  Next: Priority Queue Implementation Notes,  Prev: Basic Examples,  Up: heapq — Heap queue algorithm

5.8.6.2 Other Applications
..........................

Medians(1) are a measure of central tendency for a set of numbers.  In
distributions skewed by outliers, the median provides a more stable
estimate than an average (arithmetic mean).  A running median is an
online algorithm(2) that updates continuously as new data arrives.

A running median can be efficiently implemented by balancing two heaps,
a max-heap for values at or below the midpoint and a min-heap for values
above the midpoint.  When the two heaps have the same size, the new
median is the average of the tops of the two heaps; otherwise, the
median is at the top of the larger heap:

     def running_median(iterable):
         "Yields the cumulative median of values seen so far."

         lo = []  # max-heap
         hi = []  # min-heap (same size as or one smaller than lo)

         for x in iterable:
             if len(lo) == len(hi):
                 heappush_max(lo, heappushpop(hi, x))
                 yield lo[0]
             else:
                 heappush(hi, heappushpop_max(lo, x))
                 yield (lo[0] + hi[0]) / 2

For example:

     >>> list(running_median([5.0, 9.0, 4.0, 12.0, 8.0, 9.0]))
     [5.0, 7.0, 5.0, 7.0, 8.0, 8.5]

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Median

   (2) https://en.wikipedia.org/wiki/Online_algorithm


File: python.info,  Node: Priority Queue Implementation Notes,  Next: Theory,  Prev: Other Applications,  Up: heapq — Heap queue algorithm

5.8.6.3 Priority Queue Implementation Notes
...........................................

A priority queue(1) is common use for a heap, and it presents several
implementation challenges:

   * Sort stability: how do you get two tasks with equal priorities to
     be returned in the order they were originally added?

   * Tuple comparison breaks for (priority, task) pairs if the
     priorities are equal and the tasks do not have a default comparison
     order.

   * If the priority of a task changes, how do you move it to a new
     position in the heap?

   * Or if a pending task needs to be deleted, how do you find it and
     remove it from the queue?

A solution to the first two challenges is to store entries as 3-element
list including the priority, an entry count, and the task.  The entry
count serves as a tie-breaker so that two tasks with the same priority
are returned in the order they were added.  And since no two entry
counts are the same, the tuple comparison will never attempt to directly
compare two tasks.

Another solution to the problem of non-comparable tasks is to create a
wrapper class that ignores the task item and only compares the priority
field:

     from dataclasses import dataclass, field
     from typing import Any

     @dataclass(order=True)
     class PrioritizedItem:
         priority: int
         item: Any=field(compare=False)

The remaining challenges revolve around finding a pending task and
making changes to its priority or removing it entirely.  Finding a task
can be done with a dictionary pointing to an entry in the queue.

Removing the entry or changing its priority is more difficult because it
would break the heap structure invariants.  So, a possible solution is
to mark the entry as removed and add a new entry with the revised
priority:

     pq = []                         # list of entries arranged in a heap
     entry_finder = {}               # mapping of tasks to entries
     REMOVED = '<removed-task>'      # placeholder for a removed task
     counter = itertools.count()     # unique sequence count

     def add_task(task, priority=0):
         'Add a new task or update the priority of an existing task'
         if task in entry_finder:
             remove_task(task)
         count = next(counter)
         entry = [priority, count, task]
         entry_finder[task] = entry
         heappush(pq, entry)

     def remove_task(task):
         'Mark an existing task as REMOVED.  Raise KeyError if not found.'
         entry = entry_finder.pop(task)
         entry[-1] = REMOVED

     def pop_task():
         'Remove and return the lowest priority task. Raise KeyError if empty.'
         while pq:
             priority, count, task = heappop(pq)
             if task is not REMOVED:
                 del entry_finder[task]
                 return task
         raise KeyError('pop from an empty priority queue')

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Priority_queue


File: python.info,  Node: Theory,  Prev: Priority Queue Implementation Notes,  Up: heapq — Heap queue algorithm

5.8.6.4 Theory
..............

Heaps are arrays for which ‘a[k] <= a[2*k+1]’ and ‘a[k] <= a[2*k+2]’ for
all 'k', counting elements from 0.  For the sake of comparison,
non-existing elements are considered to be infinite.  The interesting
property of a heap is that ‘a[0]’ is always its smallest element.

The strange invariant above is meant to be an efficient memory
representation for a tournament.  The numbers below are 'k', not ‘a[k]’:

                                    0

                   1                                 2

           3               4                5               6

       7       8       9       10      11      12      13      14

     15 16   17 18   19 20   21 22   23 24   25 26   27 28   29 30

In the tree above, each cell 'k' is topping ‘2*k+1’ and ‘2*k+2’.  In a
usual binary tournament we see in sports, each cell is the winner over
the two cells it tops, and we can trace the winner down the tree to see
all opponents s/he had.  However, in many computer applications of such
tournaments, we do not need to trace the history of a winner.  To be
more memory efficient, when a winner is promoted, we try to replace it
by something else at a lower level, and the rule becomes that a cell and
the two cells it tops contain three different items, but the top cell
«wins» over the two topped cells.

If this heap invariant is protected at all time, index 0 is clearly the
overall winner.  The simplest algorithmic way to remove it and find the
«next» winner is to move some loser (let’s say cell 30 in the diagram
above) into the 0 position, and then percolate this new 0 down the tree,
exchanging values, until the invariant is re-established.  This is
clearly logarithmic on the total number of items in the tree.  By
iterating over all items, you get an 'O'('n' log 'n') sort.

A nice feature of this sort is that you can efficiently insert new items
while the sort is going on, provided that the inserted items are not
«better» than the last 0’th element you extracted.  This is especially
useful in simulation contexts, where the tree holds all incoming events,
and the «win» condition means the smallest scheduled time.  When an
event schedules other events for execution, they are scheduled into the
future, so they can easily go into the heap.  So, a heap is a good
structure for implementing schedulers (this is what I used for my MIDI
sequencer :-).

Various structures for implementing schedulers have been extensively
studied, and heaps are good for this, as they are reasonably speedy, the
speed is almost constant, and the worst case is not much different than
the average case.  However, there are other representations which are
more efficient overall, yet the worst cases might be terrible.

Heaps are also very useful in big disk sorts.  You most probably all
know that a big sort implies producing «runs» (which are pre-sorted
sequences, whose size is usually related to the amount of CPU memory),
followed by a merging passes for these runs, which merging is often very
cleverly organised (1).  It is very important that the initial sort
produces the longest runs possible.  Tournaments are a good way to
achieve that.  If, using all the memory available to hold a tournament,
you replace and percolate items that happen to fit the current run,
you’ll produce runs which are twice the size of the memory for random
input, and much better for input fuzzily ordered.

Moreover, if you output the 0’th item on disk and get an input which may
not fit in the current tournament (because the value «wins» over the
last output value), it cannot fit in the heap, so the size of the heap
decreases.  The freed memory could be cleverly reused immediately for
progressively building a second heap, which grows at exactly the same
rate the first heap is melting.  When the first heap completely
vanishes, you switch heaps and start a new run.  Clever and quite
effective!

In a word, heaps are useful memory structures to know.  I use them in a
few applications, and I think it is good to keep a “heap” module around.
:-)

   ---------- Footnotes ----------

   (1) The disk balancing algorithms which are current, nowadays, are
more annoying than clever, and this is a consequence of the seeking
capabilities of the disks.  On devices which cannot seek, like big tape
drives, the story was quite different, and one had to be very clever to
ensure (far in advance) that each tape movement will be the most
effective possible (that is, will best participate at «progressing» the
merge).  Some tapes were even able to read backwards, and this was also
used to avoid the rewinding time.  Believe me, real good tape sorts were
quite spectacular to watch!  From all times, sorting has always been a
Great Art!  :-)


File: python.info,  Node: bisect — Array bisection algorithm,  Next: array — Efficient arrays of numeric values,  Prev: heapq — Heap queue algorithm,  Up: Data Types

5.8.7 ‘bisect’ — Array bisection algorithm
------------------------------------------

'Source code:' Lib/bisect.py(1)

__________________________________________________________________

This module provides support for maintaining a list in sorted order
without having to sort the list after each insertion.  For long lists of
items with expensive comparison operations, this can be an improvement
over linear searches or frequent resorting.

The module is called *note bisect: 12. because it uses a basic bisection
algorithm to do its work.  Unlike other bisection tools that search for
a specific value, the functions in this module are designed to locate an
insertion point.  Accordingly, the functions never call an *note
__eq__(): cf4. method to determine whether a value has been found.
Instead, the functions only call the *note __lt__(): 14a8. method and
will return an insertion point between values in an array.

     Nota: The functions in this module are not thread-safe.  If
     multiple threads concurrently use *note bisect: 12. functions on
     the same sequence, this may result in undefined behaviour.
     Likewise, if the provided sequence is mutated by a different thread
     while a *note bisect: 12. function is operating on it, the result
     is undefined.  For example, using *note insort_left(): 2992. on the
     same list from multiple threads may result in the list becoming
     unsorted.
The following functions are provided:

 -- Funzione: bisect.bisect_left (a, x, lo=0, hi=len(a), *, key=None)

     Locate the insertion point for 'x' in 'a' to maintain sorted order.
     The parameters 'lo' and 'hi' may be used to specify a subset of the
     list which should be considered; by default the entire list is
     used.  If 'x' is already present in 'a', the insertion point will
     be before (to the left of) any existing entries.  The return value
     is suitable for use as the first parameter to ‘list.insert()’
     assuming that 'a' is already sorted.

     The returned insertion point 'ip' partitions the array 'a' into two
     slices such that ‘all(elem < x for elem in a[lo : ip])’ is true for
     the left slice and ‘all(elem >= x for elem in a[ip : hi])’ is true
     for the right slice.

     'key' specifies a *note key function: 1008. of one argument that is
     used to extract a comparison key from each element in the array.
     To support searching complex records, the key function is not
     applied to the 'x' value.

     If 'key' is ‘None’, the elements are compared directly and no key
     function is called.

     Cambiato nella versione 3.10: Added the 'key' parameter.

 -- Funzione: bisect.bisect_right (a, x, lo=0, hi=len(a), *, key=None)
 -- Funzione: bisect.bisect (a, x, lo=0, hi=len(a), *, key=None)

     Similar to *note bisect_left(): 2994, but returns an insertion
     point which comes after (to the right of) any existing entries of
     'x' in 'a'.

     The returned insertion point 'ip' partitions the array 'a' into two
     slices such that ‘all(elem <= x for elem in a[lo : ip])’ is true
     for the left slice and ‘all(elem > x for elem in a[ip : hi])’ is
     true for the right slice.

     Cambiato nella versione 3.10: Added the 'key' parameter.

 -- Funzione: bisect.insort_left (a, x, lo=0, hi=len(a), *, key=None)

     Insert 'x' in 'a' in sorted order.

     This function first runs *note bisect_left(): 2994. to locate an
     insertion point.  Next, it runs the *note insert(): 23c0. method on
     'a' to insert 'x' at the appropriate position to maintain sort
     order.

     To support inserting records in a table, the 'key' function (if
     any) is applied to 'x' for the search step but not for the
     insertion step.

     Keep in mind that the 'O'(log 'n') search is dominated by the slow
     'O'('n') insertion step.

     Cambiato nella versione 3.10: Added the 'key' parameter.

 -- Funzione: bisect.insort_right (a, x, lo=0, hi=len(a), *, key=None)
 -- Funzione: bisect.insort (a, x, lo=0, hi=len(a), *, key=None)

     Similar to *note insort_left(): 2992, but inserting 'x' in 'a'
     after any existing entries of 'x'.

     This function first runs *note bisect_right(): 2995. to locate an
     insertion point.  Next, it runs the *note insert(): 23c0. method on
     'a' to insert 'x' at the appropriate position to maintain sort
     order.

     To support inserting records in a table, the 'key' function (if
     any) is applied to 'x' for the search step but not for the
     insertion step.

     Keep in mind that the 'O'(log 'n') search is dominated by the slow
     'O'('n') insertion step.

     Cambiato nella versione 3.10: Added the 'key' parameter.

* Menu:

* Performance Notes::
* Searching Sorted Lists::
* Examples: Examples<3>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/bisect.py


File: python.info,  Node: Performance Notes,  Next: Searching Sorted Lists,  Up: bisect — Array bisection algorithm

5.8.7.1 Performance Notes
.........................

When writing time sensitive code using 'bisect()' and 'insort()', keep
these thoughts in mind:

   * Bisection is effective for searching ranges of values.  For
     locating specific values, dictionaries are more performant.

   * The 'insort()' functions are 'O'('n') because the logarithmic
     search step is dominated by the linear time insertion step.

   * The search functions are stateless and discard key function results
     after they are used.  Consequently, if the search functions are
     used in a loop, the key function may be called again and again on
     the same array elements.  If the key function isn’t fast, consider
     wrapping it with *note functools.cache(): 17b0. to avoid duplicate
     computations.  Alternatively, consider searching an array of
     precomputed keys to locate the insertion point (as shown in the
     examples section below).

Vedi anche
..........

   * Sorted Collections(1) is a high performance module that uses
     'bisect' to managed sorted collections of data.

   * The SortedCollection recipe(2) uses bisect to build a full-featured
     collection class with straight-forward search methods and support
     for a key-function.  The keys are precomputed to save unnecessary
     calls to the key function during searches.

   ---------- Footnotes ----------

   (1) https://grantjenks.com/docs/sortedcollections/

   (2) https://code.activestate.com/recipes/577197-sortedcollection/


File: python.info,  Node: Searching Sorted Lists,  Next: Examples<3>,  Prev: Performance Notes,  Up: bisect — Array bisection algorithm

5.8.7.2 Searching Sorted Lists
..............................

The above *note bisect functions: 2993. are useful for finding insertion
points but can be tricky or awkward to use for common searching tasks.
The following five functions show how to transform them into the
standard lookups for sorted lists:

     def index(a, x):
         'Locate the leftmost value exactly equal to x'
         i = bisect_left(a, x)
         if i != len(a) and a[i] == x:
             return i
         raise ValueError

     def find_lt(a, x):
         'Find rightmost value less than x'
         i = bisect_left(a, x)
         if i:
             return a[i-1]
         raise ValueError

     def find_le(a, x):
         'Find rightmost value less than or equal to x'
         i = bisect_right(a, x)
         if i:
             return a[i-1]
         raise ValueError

     def find_gt(a, x):
         'Find leftmost value greater than x'
         i = bisect_right(a, x)
         if i != len(a):
             return a[i]
         raise ValueError

     def find_ge(a, x):
         'Find leftmost item greater than or equal to x'
         i = bisect_left(a, x)
         if i != len(a):
             return a[i]
         raise ValueError


File: python.info,  Node: Examples<3>,  Prev: Searching Sorted Lists,  Up: bisect — Array bisection algorithm

5.8.7.3 Examples
................

The *note bisect(): 2996. function can be useful for numeric table
lookups.  This example uses *note bisect(): 2996. to look up a letter
grade for an exam score (say) based on a set of ordered numeric
breakpoints: 90 and up is an “A”, 80 to 89 is a “B”, and so on:

     >>> def grade(score, breakpoints=[60, 70, 80, 90], grades='FDCBA'):
     ...     i = bisect(breakpoints, score)
     ...     return grades[i]
     ...
     >>> [grade(score) for score in [33, 99, 77, 70, 89, 90, 100]]
     ['F', 'A', 'C', 'C', 'B', 'A', 'A']

The *note bisect(): 2996. and *note insort(): 2998. functions also work
with lists of tuples.  The 'key' argument can serve to extract the field
used for ordering records in a table:

     >>> from collections import namedtuple
     >>> from operator import attrgetter
     >>> from bisect import bisect, insort
     >>> from pprint import pprint

     >>> Movie = namedtuple('Movie', ('name', 'released', 'director'))

     >>> movies = [
     ...     Movie('Jaws', 1975, 'Spielberg'),
     ...     Movie('Titanic', 1997, 'Cameron'),
     ...     Movie('The Birds', 1963, 'Hitchcock'),
     ...     Movie('Aliens', 1986, 'Cameron')
     ... ]

     >>> # Find the first movie released after 1960
     >>> by_year = attrgetter('released')
     >>> movies.sort(key=by_year)
     >>> movies[bisect(movies, 1960, key=by_year)]
     Movie(name='The Birds', released=1963, director='Hitchcock')

     >>> # Insert a movie while maintaining sort order
     >>> romance = Movie('Love Story', 1970, 'Hiller')
     >>> insort(movies, romance, key=by_year)
     >>> pprint(movies)
     [Movie(name='The Birds', released=1963, director='Hitchcock'),
      Movie(name='Love Story', released=1970, director='Hiller'),
      Movie(name='Jaws', released=1975, director='Spielberg'),
      Movie(name='Aliens', released=1986, director='Cameron'),
      Movie(name='Titanic', released=1997, director='Cameron')]

If the key function is expensive, it is possible to avoid repeated
function calls by searching a list of precomputed keys to find the index
of a record:

     >>> data = [('red', 5), ('blue', 1), ('yellow', 8), ('black', 0)]
     >>> data.sort(key=lambda r: r[1])       # Or use operator.itemgetter(1).
     >>> keys = [r[1] for r in data]         # Precompute a list of keys.
     >>> data[bisect_left(keys, 0)]
     ('black', 0)
     >>> data[bisect_left(keys, 1)]
     ('blue', 1)
     >>> data[bisect_left(keys, 5)]
     ('red', 5)
     >>> data[bisect_left(keys, 8)]
     ('yellow', 8)


File: python.info,  Node: array — Efficient arrays of numeric values,  Next: weakref — Weak references,  Prev: bisect — Array bisection algorithm,  Up: Data Types

5.8.8 ‘array’ — Efficient arrays of numeric values
--------------------------------------------------

__________________________________________________________________

This module defines an object type which can compactly represent an
array of basic values: characters, integers, floating-point numbers.
Arrays are mutable *note sequence: 717. types and behave very much like
lists, except that the type of objects stored in them is constrained.
The type is specified at object creation time by using a 'type code',
which is a single character.  The following type codes are defined:

Type code       C Type                   Python Type             Minimum size in bytes       Notes
                                                                                             
---------------------------------------------------------------------------------------------------------
                                                                                             
‘'b'’           signed char              int                     1
                                                                 
                                                                                             
‘'B'’           unsigned char            int                     1
                                                                 
                                                                                             
‘'u'’           wchar_t                  Unicode character       2                           (1)
                                                                                             
                                                                                             
‘'w'’           Py_UCS4                  Unicode character       4                           (2)
                                                                                             
                                                                                             
‘'h'’           signed short             int                     2
                                                                 
                                                                                             
‘'H'’           unsigned short           int                     2
                                                                 
                                                                                             
‘'i'’           signed int               int                     2
                                                                 
                                                                                             
‘'I'’           unsigned int             int                     2
                                                                 
                                                                                             
‘'l'’           signed long              int                     4
                                                                 
                                                                                             
‘'L'’           unsigned long            int                     4
                                                                 
                                                                                             
‘'q'’           signed long long         int                     8
                                                                 
                                                                                             
‘'Q'’           unsigned long long       int                     8
                                                                 
                                                                                             
‘'f'’           float                    float                   4
                                                                 
                                                                                             
‘'d'’           double                   float                   8
                                                                 

Notes:

  1. It can be 16 bits or 32 bits depending on the platform.

     Cambiato nella versione 3.9: ‘array('u')’ now uses ‘wchar_t’ as C
     type instead of deprecated ‘Py_UNICODE’.  This change doesn’t
     affect its behavior because ‘Py_UNICODE’ is alias of ‘wchar_t’
     since Python 3.3.

     Deprecated since version 3.3, will be removed in version 3.16:
     Please migrate to ‘'w'’ typecode.

  2. 
     Added in version 3.13.

The actual representation of values is determined by the machine
architecture (strictly speaking, by the C implementation).  The actual
size can be accessed through the *note array.itemsize: 29a0. attribute.

The module defines the following item:

 -- Dati: array.typecodes

     A string with all available type codes.

The module defines the following type:

 -- Classe: array.array (typecode[, initializer])

     A new array whose items are restricted by 'typecode', and
     initialized from the optional 'initializer' value, which must be a
     *note bytes: 192. or *note bytearray: 344. object, a Unicode
     string, or iterable over elements of the appropriate type.

     If given a *note bytes: 192. or *note bytearray: 344. object, the
     initializer is passed to the new array’s *note frombytes(): 1479.
     method; if given a Unicode string, the initializer is passed to the
     *note fromunicode(): 29a2. method; otherwise, the initializer’s
     iterator is passed to the *note extend(): 29a3. method to add
     initial items to the array.

     Array objects support the ordinary *note mutable: 259e. *note
     sequence: 717. operations of indexing, slicing, concatenation, and
     multiplication.  When using slice assignment, the assigned value
     must be an array object with the same type code; in all other
     cases, *note TypeError: 198. is raised.  Array objects also
     implement the buffer interface, and may be used wherever *note
     bytes-like objects: 193. are supported.

     Raises an *note auditing event: 1c56. ‘array.__new__’ with
     arguments ‘typecode’, ‘initializer’.

      -- Attributo: typecode

          The typecode character used to create the array.

      -- Attributo: itemsize

          The length in bytes of one array item in the internal
          representation.

      -- Metodo: append (x)

          Append a new item with value 'x' to the end of the array.

      -- Metodo: buffer_info ()

          Return a tuple ‘(address, length)’ giving the current memory
          address and the length in elements of the buffer used to hold
          array’s contents.  The size of the memory buffer in bytes can
          be computed as ‘array.buffer_info()[1] * array.itemsize’.
          This is occasionally useful when working with low-level (and
          inherently unsafe) I/O interfaces that require memory
          addresses, such as certain ‘ioctl()’ operations.  The returned
          numbers are valid as long as the array exists and no
          length-changing operations are applied to it.

               Nota: When using array objects from code written in C or
               C++ (the only way to effectively make use of this
               information), it makes more sense to use the buffer
               interface supported by array objects.  This method is
               maintained for backward compatibility and should be
               avoided in new code.  The buffer interface is documented
               in *note Buffer Protocol: 260.

      -- Metodo: byteswap ()

          «Byteswap» all items of the array.  This is only supported for
          values which are 1, 2, 4, or 8 bytes in size; for other types
          of values, *note RuntimeError: 244. is raised.  It is useful
          when reading data from a file written on a machine with a
          different byte order.

      -- Metodo: count (x)

          Return the number of occurrences of 'x' in the array.

      -- Metodo: extend (iterable)

          Append items from 'iterable' to the end of the array.  If
          'iterable' is another array, it must have 'exactly' the same
          type code; if not, *note TypeError: 198. will be raised.  If
          'iterable' is not an array, it must be iterable and its
          elements must be the right type to be appended to the array.

      -- Metodo: frombytes (buffer)

          Appends items from the *note bytes-like object: 193,
          interpreting its content as an array of machine values (as if
          it had been read from a file using the *note fromfile(): 14c8.
          method).

          Added in version 3.2: ‘fromstring()’ is renamed to *note
          frombytes(): 1479. for clarity.

      -- Metodo: fromfile (f, n)

          Read 'n' items (as machine values) from the *note file object:
          13cb. 'f' and append them to the end of the array.  If less
          than 'n' items are available, *note EOFError: 14e1. is raised,
          but the items that were available are still inserted into the
          array.

      -- Metodo: fromlist (list)

          Append items from the list.  This is equivalent to ‘for x in
          list: a.append(x)’ except that if there is a type error, the
          array is unchanged.

      -- Metodo: fromunicode (s)

          Extends this array with data from the given Unicode string.
          The array must have type code ‘'u'’ or ‘'w'’; otherwise a
          *note ValueError: 2ec. is raised.  Use
          ‘array.frombytes(unicodestring.encode(enc))’ to append Unicode
          data to an array of some other type.

      -- Metodo: index (x[, start[, stop]])

          Return the smallest 'i' such that 'i' is the index of the
          first occurrence of 'x' in the array.  The optional arguments
          'start' and 'stop' can be specified to search for 'x' within a
          subsection of the array.  Raise *note ValueError: 2ec. if 'x'
          is not found.

          Cambiato nella versione 3.10: Added optional 'start' and
          'stop' parameters.

      -- Metodo: insert (i, x)

          Insert a new item with value 'x' in the array before position
          'i'.  Negative values are treated as being relative to the end
          of the array.

      -- Metodo: pop ([i])

          Removes the item with the index 'i' from the array and returns
          it.  The optional argument defaults to ‘-1’, so that by
          default the last item is removed and returned.

      -- Metodo: remove (x)

          Remove the first occurrence of 'x' from the array.

      -- Metodo: clear ()

          Remove all elements from the array.

          Added in version 3.13.

      -- Metodo: reverse ()

          Reverse the order of the items in the array.

      -- Metodo: tobytes ()

          Convert the array to an array of machine values and return the
          bytes representation (the same sequence of bytes that would be
          written to a file by the *note tofile(): 14c9. method.)

          Added in version 3.2: ‘tostring()’ is renamed to *note
          tobytes(): 1478. for clarity.

      -- Metodo: tofile (f)

          Write all items (as machine values) to the *note file object:
          13cb. 'f'.

      -- Metodo: tolist ()

          Convert the array to an ordinary list with the same items.

      -- Metodo: tounicode ()

          Convert the array to a Unicode string.  The array must have a
          type ‘'u'’ or ‘'w'’; otherwise a *note ValueError: 2ec. is
          raised.  Use ‘array.tobytes().decode(enc)’ to obtain a Unicode
          string from an array of some other type.

The string representation of array objects has the form ‘array(typecode,
initializer)’.  The 'initializer' is omitted if the array is empty,
otherwise it is a Unicode string if the 'typecode' is ‘'u'’ or ‘'w'’,
otherwise it is a list of numbers.  The string representation is
guaranteed to be able to be converted back to an array with the same
type and value using *note eval(): 4a4, so long as the *note array: 4bf.
class has been imported using ‘from array import array’.  Variables
‘inf’ and ‘nan’ must also be defined if it contains corresponding
floating-point values.  Examples:

     array('l')
     array('w', 'hello \u2641')
     array('l', [1, 2, 3, 4, 5])
     array('d', [1.0, 2.0, 3.14, -inf, nan])

Vedi anche
..........

Module *note struct: db.

     Packing and unpacking of heterogeneous binary data.

NumPy(1)

     The NumPy package defines another array type.

   ---------- Footnotes ----------

   (1) https://numpy.org/


File: python.info,  Node: weakref — Weak references,  Next: types — Dynamic type creation and names for built-in types,  Prev: array — Efficient arrays of numeric values,  Up: Data Types

5.8.9 ‘weakref’ — Weak references
---------------------------------

'Source code:' Lib/weakref.py(1)

__________________________________________________________________

The *note weakref: 11a. module allows the Python programmer to create
'weak references' to objects.

In the following, the term 'referent' means the object which is referred
to by a weak reference.

A weak reference to an object is not enough to keep the object alive:
when the only remaining references to a referent are weak references,
*note garbage collection: 17c0. is free to destroy the referent and
reuse its memory for something else.  However, until the object is
actually destroyed the weak reference may return the object even if
there are no strong references to it.

A primary use for weak references is to implement caches or mappings
holding large objects, where it’s desired that a large object not be
kept alive solely because it appears in a cache or mapping.

For example, if you have a number of large binary image objects, you may
wish to associate a name with each.  If you used a Python dictionary to
map names to images, or images to names, the image objects would remain
alive just because they appeared as values or keys in the dictionaries.
The *note WeakKeyDictionary: 1911. and *note WeakValueDictionary: 1912.
classes supplied by the *note weakref: 11a. module are an alternative,
using weak references to construct mappings that don’t keep objects
alive solely because they appear in the mapping objects.  If, for
example, an image object is a value in a *note WeakValueDictionary:
1912, then when the last remaining references to that image object are
the weak references held by weak mappings, garbage collection can
reclaim the object, and its corresponding entries in weak mappings are
simply deleted.

*note WeakKeyDictionary: 1911. and *note WeakValueDictionary: 1912. use
weak references in their implementation, setting up callback functions
on the weak references that notify the weak dictionaries when a key or
value has been reclaimed by garbage collection.  *note WeakSet: 7f6.
implements the *note set: 184. interface, but keeps weak references to
its elements, just like a *note WeakKeyDictionary: 1911. does.

*note finalize: c71. provides a straight forward way to register a
cleanup function to be called when an object is garbage collected.  This
is simpler to use than setting up a callback function on a raw weak
reference, since the module automatically ensures that the finalizer
remains alive until the object is collected.

Most programs should find that using one of these weak container types
or *note finalize: c71. is all they need – it’s not usually necessary to
create your own weak references directly.  The low-level machinery is
exposed by the *note weakref: 11a. module for the benefit of advanced
uses.

Not all objects can be weakly referenced.  Objects which support weak
references include class instances, functions written in Python (but not
in C), instance methods, sets, frozensets, some *note file objects:
13cb, *note generators: 1263, type objects, sockets, arrays, deques,
regular expression pattern objects, and code objects.

Cambiato nella versione 3.2: Added support for thread.lock,
threading.Lock, and code objects.

Several built-in types such as *note list: 24d. and *note dict: 183. do
not directly support weak references but can add support through
subclassing:

     class Dict(dict):
         pass

     obj = Dict(red=1, green=2, blue=3)   # this object is weak referenceable

'Dettaglio dell’implementazione di CPython:' Other built-in types such
as *note tuple: 614. and *note int: 19b. do not support weak references
even when subclassed.

Extension types can easily be made to support weak references; see *note
Weak Reference Support: 29b3.

When ‘__slots__’ are defined for a given type, weak reference support is
disabled unless a ‘'__weakref__'’ string is also present in the sequence
of strings in the ‘__slots__’ declaration.  See *note __slots__
documentation: 2365. for details.

 -- Classe: weakref.ref (object[, callback])

     Return a weak reference to 'object'.  The original object can be
     retrieved by calling the reference object if the referent is still
     alive; if the referent is no longer alive, calling the reference
     object will cause *note None: 886. to be returned.  If 'callback'
     is provided and not *note None: 886, and the returned weakref
     object is still alive, the callback will be called when the object
     is about to be finalized; the weak reference object will be passed
     as the only parameter to the callback; the referent will no longer
     be available.

     It is allowable for many weak references to be constructed for the
     same object.  Callbacks registered for each weak reference will be
     called from the most recently registered callback to the oldest
     registered callback.

     Exceptions raised by the callback will be noted on the standard
     error output, but cannot be propagated; they are handled in exactly
     the same way as exceptions raised from an object’s *note __del__():
     11ff. method.

     Weak references are *note hashable: 825. if the 'object' is
     hashable.  They will maintain their hash value even after the
     'object' was deleted.  If *note hash(): 802. is called the first
     time only after the 'object' was deleted, the call will raise *note
     TypeError: 198.

     Weak references support tests for equality, but not ordering.  If
     the referents are still alive, two references have the same
     equality relationship as their referents (regardless of the
     'callback').  If either referent has been deleted, the references
     are equal only if the reference objects are the same object.

     This is a subclassable type rather than a factory function.

      -- Attributo: __callback__

          This read-only attribute returns the callback currently
          associated to the weakref.  If there is no callback or if the
          referent of the weakref is no longer alive then this attribute
          will have value ‘None’.

     Cambiato nella versione 3.4: Added the *note __callback__: 11f3.
     attribute.

 -- Funzione: weakref.proxy (object[, callback])

     Return a proxy to 'object' which uses a weak reference.  This
     supports use of the proxy in most contexts instead of requiring the
     explicit dereferencing used with weak reference objects.  The
     returned object will have a type of either ‘ProxyType’ or
     ‘CallableProxyType’, depending on whether 'object' is callable.
     Proxy objects are not *note hashable: 825. regardless of the
     referent; this avoids a number of problems related to their
     fundamentally mutable nature, and prevents their use as dictionary
     keys.  'callback' is the same as the parameter of the same name to
     the *note ref(): 11f2. function.

     Accessing an attribute of the proxy object after the referent is
     garbage collected raises *note ReferenceError: 1714.

     Cambiato nella versione 3.8: Extended the operator support on proxy
     objects to include the matrix multiplication operators ‘@’ and
     ‘@=’.

 -- Funzione: weakref.getweakrefcount (object)

     Return the number of weak references and proxies which refer to
     'object'.

 -- Funzione: weakref.getweakrefs (object)

     Return a list of all weak reference and proxy objects which refer
     to 'object'.

 -- Classe: weakref.WeakKeyDictionary ([dict])

     Mapping class that references keys weakly.  Entries in the
     dictionary will be discarded when there is no longer a strong
     reference to the key.  This can be used to associate additional
     data with an object owned by other parts of an application without
     adding attributes to those objects.  This can be especially useful
     with objects that override attribute accesses.

     Note that when a key with equal value to an existing key (but not
     equal identity) is inserted into the dictionary, it replaces the
     value but does not replace the existing key.  Due to this, when the
     reference to the original key is deleted, it also deletes the entry
     in the dictionary:

          >>> class T(str): pass
          ...
          >>> k1, k2 = T(), T()
          >>> d = weakref.WeakKeyDictionary()
          >>> d[k1] = 1   # d = {k1: 1}
          >>> d[k2] = 2   # d = {k1: 2}
          >>> del k1      # d = {}

     A workaround would be to remove the key prior to reassignment:

          >>> class T(str): pass
          ...
          >>> k1, k2 = T(), T()
          >>> d = weakref.WeakKeyDictionary()
          >>> d[k1] = 1   # d = {k1: 1}
          >>> del d[k1]
          >>> d[k2] = 2   # d = {k2: 2}
          >>> del k1      # d = {k2: 2}

     Cambiato nella versione 3.9: Added support for ‘|’ and ‘|=’
     operators, as specified in PEP 584(2).

*note WeakKeyDictionary: 1911. objects have an additional method that
exposes the internal references directly.  The references are not
guaranteed to be «live» at the time they are used, so the result of
calling the references needs to be checked before being used.  This can
be used to avoid creating references that will cause the garbage
collector to keep the keys around longer than needed.

 -- Metodo: WeakKeyDictionary.keyrefs ()

     Return an iterable of the weak references to the keys.

 -- Classe: weakref.WeakValueDictionary ([dict])

     Mapping class that references values weakly.  Entries in the
     dictionary will be discarded when no strong reference to the value
     exists any more.

     Cambiato nella versione 3.9: Added support for ‘|’ and ‘|=’
     operators, as specified in PEP 584(3).

*note WeakValueDictionary: 1912. objects have an additional method that
has the same issues as the *note WeakKeyDictionary.keyrefs(): 29b6.
method.

 -- Metodo: WeakValueDictionary.valuerefs ()

     Return an iterable of the weak references to the values.

 -- Classe: weakref.WeakSet ([elements])

     Set class that keeps weak references to its elements.  An element
     will be discarded when no strong reference to it exists any more.

 -- Classe: weakref.WeakMethod (method[, callback])

     A custom *note ref: 11f2. subclass which simulates a weak reference
     to a bound method (i.e., a method defined on a class and looked up
     on an instance).  Since a bound method is ephemeral, a standard
     weak reference cannot keep hold of it.  *note WeakMethod: 11f1. has
     special code to recreate the bound method until either the object
     or the original function dies:

          >>> class C:
          ...     def method(self):
          ...         print("method called!")
          ...
          >>> c = C()
          >>> r = weakref.ref(c.method)
          >>> r()
          >>> r = weakref.WeakMethod(c.method)
          >>> r()
          <bound method C.method of <__main__.C object at 0x7fc859830220>>
          >>> r()()
          method called!
          >>> del c
          >>> gc.collect()
          0
          >>> r()
          >>>

     'callback' is the same as the parameter of the same name to the
     *note ref(): 11f2. function.

     Added in version 3.4.

 -- Classe: weakref.finalize (obj, func, /, *args, **kwargs)

     Return a callable finalizer object which will be called when 'obj'
     is garbage collected.  Unlike an ordinary weak reference, a
     finalizer will always survive until the reference object is
     collected, greatly simplifying lifecycle management.

     A finalizer is considered 'alive' until it is called (either
     explicitly or at garbage collection), and after that it is 'dead'.
     Calling a live finalizer returns the result of evaluating
     ‘func(*arg, **kwargs)’, whereas calling a dead finalizer returns
     *note None: 886.

     Exceptions raised by finalizer callbacks during garbage collection
     will be shown on the standard error output, but cannot be
     propagated.  They are handled in the same way as exceptions raised
     from an object’s *note __del__(): 11ff. method or a weak
     reference’s callback.

     When the program exits, each remaining live finalizer is called
     unless its *note atexit: d. attribute has been set to false.  They
     are called in reverse order of creation.

     A finalizer will never invoke its callback during the later part of
     the *note interpreter shutdown: 47a. when module globals are liable
     to have been replaced by *note None: 886.

      -- Metodo: __call__ ()

          If 'self' is alive then mark it as dead and return the result
          of calling ‘func(*args, **kwargs)’.  If 'self' is dead then
          return *note None: 886.

      -- Metodo: detach ()

          If 'self' is alive then mark it as dead and return the tuple
          ‘(obj, func, args, kwargs)’.  If 'self' is dead then return
          *note None: 886.

      -- Metodo: peek ()

          If 'self' is alive then return the tuple ‘(obj, func, args,
          kwargs)’.  If 'self' is dead then return *note None: 886.

      -- Attributo: alive

          Property which is true if the finalizer is alive, false
          otherwise.

      -- Attributo: atexit

          A writable boolean property which by default is true.  When
          the program exits, it calls all remaining live finalizers for
          which *note atexit: 29bc. is true.  They are called in reverse
          order of creation.

          Nota: It is important to ensure that 'func', 'args' and
          'kwargs' do not own any references to 'obj', either directly
          or indirectly, since otherwise 'obj' will never be garbage
          collected.  In particular, 'func' should not be a bound method
          of 'obj'.

     Added in version 3.4.

 -- Dati: weakref.ReferenceType

     The type object for weak references objects.

 -- Dati: weakref.ProxyType

     The type object for proxies of objects which are not callable.

 -- Dati: weakref.CallableProxyType

     The type object for proxies of callable objects.

 -- Dati: weakref.ProxyTypes

     Sequence containing all the type objects for proxies.  This can
     make it simpler to test if an object is a proxy without being
     dependent on naming both proxy types.

Vedi anche
..........

PEP 205(4) - Weak References

     The proposal and rationale for this feature, including links to
     earlier implementations and information about similar features in
     other languages.

* Menu:

* Weak Reference Objects::
* Example: Example<2>.
* Finalizer Objects::
* Comparing finalizers with __del__() methods: Comparing finalizers with __del__ methods.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/weakref.py

   (2) https://peps.python.org/pep-0584/

   (3) https://peps.python.org/pep-0584/

   (4) https://peps.python.org/pep-0205/


File: python.info,  Node: Weak Reference Objects,  Next: Example<2>,  Up: weakref — Weak references

5.8.9.1 Weak Reference Objects
..............................

Weak reference objects have no methods and no attributes besides *note
ref.__callback__: 11f3.  A weak reference object allows the referent to
be obtained, if it still exists, by calling it:

     >>> import weakref
     >>> class Object:
     ...     pass
     ...
     >>> o = Object()
     >>> r = weakref.ref(o)
     >>> o2 = r()
     >>> o is o2
     True

If the referent no longer exists, calling the reference object returns
*note None: 886.:

     >>> del o, o2
     >>> print(r())
     None

Testing that a weak reference object is still live should be done using
the expression ‘ref() is not None’.  Normally, application code that
needs to use a reference object should follow this pattern:

     # r is a weak reference object
     o = r()
     if o is None:
         # referent has been garbage collected
         print("Object has been deallocated; can't frobnicate.")
     else:
         print("Object is still live!")
         o.do_something_useful()

Using a separate test for «liveness» creates race conditions in threaded
applications; another thread can cause a weak reference to become
invalidated before the weak reference is called; the idiom shown above
is safe in threaded applications as well as single-threaded
applications.

Specialized versions of *note ref: 11f2. objects can be created through
subclassing.  This is used in the implementation of the *note
WeakValueDictionary: 1912. to reduce the memory overhead for each entry
in the mapping.  This may be most useful to associate additional
information with a reference, but could also be used to insert
additional processing on calls to retrieve the referent.

This example shows how a subclass of *note ref: 11f2. can be used to
store additional information about an object and affect the value that’s
returned when the referent is accessed:

     import weakref

     class ExtendedRef(weakref.ref):
         def __init__(self, ob, callback=None, /, **annotations):
             super().__init__(ob, callback)
             self.__counter = 0
             for k, v in annotations.items():
                 setattr(self, k, v)

         def __call__(self):
             """Return a pair containing the referent and the number of
             times the reference has been called.
             """
             ob = super().__call__()
             if ob is not None:
                 self.__counter += 1
                 ob = (ob, self.__counter)
             return ob


File: python.info,  Node: Example<2>,  Next: Finalizer Objects,  Prev: Weak Reference Objects,  Up: weakref — Weak references

5.8.9.2 Example
...............

This simple example shows how an application can use object IDs to
retrieve objects that it has seen before.  The IDs of the objects can
then be used in other data structures without forcing the objects to
remain alive, but the objects can still be retrieved by ID if they do.

     import weakref

     _id2obj_dict = weakref.WeakValueDictionary()

     def remember(obj):
         oid = id(obj)
         _id2obj_dict[oid] = obj
         return oid

     def id2obj(oid):
         return _id2obj_dict[oid]


File: python.info,  Node: Finalizer Objects,  Next: Comparing finalizers with __del__ methods,  Prev: Example<2>,  Up: weakref — Weak references

5.8.9.3 Finalizer Objects
.........................

The main benefit of using *note finalize: c71. is that it makes it
simple to register a callback without needing to preserve the returned
finalizer object.  For instance

     >>> import weakref
     >>> class Object:
     ...     pass
     ...
     >>> kenny = Object()
     >>> weakref.finalize(kenny, print, "You killed Kenny!")
     <finalize object at ...; for 'Object' at ...>
     >>> del kenny
     You killed Kenny!

The finalizer can be called directly as well.  However the finalizer
will invoke the callback at most once.

     >>> def callback(x, y, z):
     ...     print("CALLBACK")
     ...     return x + y + z
     ...
     >>> obj = Object()
     >>> f = weakref.finalize(obj, callback, 1, 2, z=3)
     >>> assert f.alive
     >>> assert f() == 6
     CALLBACK
     >>> assert not f.alive
     >>> f()                     # callback not called because finalizer dead
     >>> del obj                 # callback not called because finalizer dead

You can unregister a finalizer using its *note detach(): 29b9. method.
This kills the finalizer and returns the arguments passed to the
constructor when it was created.

     >>> obj = Object()
     >>> f = weakref.finalize(obj, callback, 1, 2, z=3)
     >>> f.detach()
     (<...Object object ...>, <function callback ...>, (1, 2), {'z': 3})
     >>> newobj, func, args, kwargs = _
     >>> assert not f.alive
     >>> assert newobj is obj
     >>> assert func(*args, **kwargs) == 6
     CALLBACK

Unless you set the *note atexit: 29bc. attribute to *note False: d2d, a
finalizer will be called when the program exits if it is still alive.
For instance

     >>> obj = Object()
     >>> weakref.finalize(obj, print, "obj dead or exiting")
     <finalize object at ...; for 'Object' at ...>
     >>> exit()
     obj dead or exiting


File: python.info,  Node: Comparing finalizers with __del__ methods,  Prev: Finalizer Objects,  Up: weakref — Weak references

5.8.9.4 Comparing finalizers with ‘__del__()’ methods
.....................................................

Suppose we want to create a class whose instances represent temporary
directories.  The directories should be deleted with their contents when
the first of the following events occurs:

   * the object is garbage collected,

   * the object’s ‘remove()’ method is called, or

   * the program exits.

We might try to implement the class using a *note __del__(): 11ff.
method as follows:

     class TempDir:
         def __init__(self):
             self.name = tempfile.mkdtemp()

         def remove(self):
             if self.name is not None:
                 shutil.rmtree(self.name)
                 self.name = None

         @property
         def removed(self):
             return self.name is None

         def __del__(self):
             self.remove()

Starting with Python 3.4, *note __del__(): 11ff. methods no longer
prevent reference cycles from being garbage collected, and module
globals are no longer forced to *note None: 886. during *note
interpreter shutdown: 47a.  So this code should work without any issues
on CPython.

However, handling of *note __del__(): 11ff. methods is notoriously
implementation specific, since it depends on internal details of the
interpreter’s garbage collector implementation.

A more robust alternative can be to define a finalizer which only
references the specific functions and objects that it needs, rather than
having access to the full state of the object:

     class TempDir:
         def __init__(self):
             self.name = tempfile.mkdtemp()
             self._finalizer = weakref.finalize(self, shutil.rmtree, self.name)

         def remove(self):
             self._finalizer()

         @property
         def removed(self):
             return not self._finalizer.alive

Defined like this, our finalizer only receives a reference to the
details it needs to clean up the directory appropriately.  If the object
never gets garbage collected the finalizer will still be called at exit.

The other advantage of weakref based finalizers is that they can be used
to register finalizers for classes where the definition is controlled by
a third party, such as running code when a module is unloaded:

     import weakref, sys
     def unloading_module():
         # implicit reference to the module globals from the function body
     weakref.finalize(sys.modules[__name__], unloading_module)

     Nota: If you create a finalizer object in a daemonic thread just as
     the program exits then there is the possibility that the finalizer
     does not get called at exit.  However, in a daemonic thread *note
     atexit.register(): a80, ‘try: ... finally: ...’ and ‘with: ...’ do
     not guarantee that cleanup occurs either.


File: python.info,  Node: types — Dynamic type creation and names for built-in types,  Next: copy — Shallow and deep copy operations,  Prev: weakref — Weak references,  Up: Data Types

5.8.10 ‘types’ — Dynamic type creation and names for built-in types
-------------------------------------------------------------------

'Source code:' Lib/types.py(1)

__________________________________________________________________

This module defines utility functions to assist in dynamic creation of
new types.

It also defines names for some object types that are used by the
standard Python interpreter, but not exposed as builtins like *note int:
19b. or *note str: 169. are.

Finally, it provides some additional type-related utility classes and
functions that are not fundamental enough to be builtins.

* Menu:

* Dynamic Type Creation::
* Standard Interpreter Types::
* Additional Utility Classes and Functions::
* Coroutine Utility Functions::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/types.py


File: python.info,  Node: Dynamic Type Creation,  Next: Standard Interpreter Types,  Up: types — Dynamic type creation and names for built-in types

5.8.10.1 Dynamic Type Creation
..............................

 -- Funzione: types.new_class (name, bases=(), kwds=None,
          exec_body=None)

     Creates a class object dynamically using the appropriate metaclass.

     The first three arguments are the components that make up a class
     definition header: the class name, the base classes (in order), the
     keyword arguments (such as ‘metaclass’).

     The 'exec_body' argument is a callback that is used to populate the
     freshly created class namespace.  It should accept the class
     namespace as its sole argument and update the namespace directly
     with the class contents.  If no callback is provided, it has the
     same effect as passing in ‘lambda ns: None’.

     Added in version 3.3.

 -- Funzione: types.prepare_class (name, bases=(), kwds=None)

     Calculates the appropriate metaclass and creates the class
     namespace.

     The arguments are the components that make up a class definition
     header: the class name, the base classes (in order) and the keyword
     arguments (such as ‘metaclass’).

     The return value is a 3-tuple: ‘metaclass, namespace, kwds’

     'metaclass' is the appropriate metaclass, 'namespace' is the
     prepared class namespace and 'kwds' is an updated copy of the
     passed in 'kwds' argument with any ‘'metaclass'’ entry removed.  If
     no 'kwds' argument is passed in, this will be an empty dict.

     Added in version 3.3.

     Cambiato nella versione 3.6: The default value for the ‘namespace’
     element of the returned tuple has changed.  Now an
     insertion-order-preserving mapping is used when the metaclass does
     not have a ‘__prepare__’ method.

Vedi anche
..........

*note Metaclasses: 23a4.

     Full details of the class creation process supported by these
     functions

PEP 3115(1) - Metaclasses in Python 3000

     Introduced the ‘__prepare__’ namespace hook

 -- Funzione: types.resolve_bases (bases)

     Resolve MRO entries dynamically as specified by PEP 560(2).

     This function looks for items in 'bases' that are not instances of
     *note type: f46, and returns a tuple where each such object that
     has an *note __mro_entries__(): ce5. method is replaced with an
     unpacked result of calling this method.  If a 'bases' item is an
     instance of *note type: f46, or it doesn’t have an
     ‘__mro_entries__()’ method, then it is included in the return tuple
     unchanged.

     Added in version 3.7.

 -- Funzione: types.get_original_bases (cls, /)

     Return the tuple of objects originally given as the bases of 'cls'
     before the *note __mro_entries__(): ce5. method has been called on
     any bases (following the mechanisms laid out in PEP 560(3)).  This
     is useful for introspecting *note Generics: 6f7.

     For classes that have an ‘__orig_bases__’ attribute, this function
     returns the value of ‘cls.__orig_bases__’.  For classes without the
     ‘__orig_bases__’ attribute, *note cls.__bases__: 16b3. is returned.

     Examples:

          from typing import TypeVar, Generic, NamedTuple, TypedDict

          T = TypeVar("T")
          class Foo(Generic[T]): ...
          class Bar(Foo[int], float): ...
          class Baz(list[str]): ...
          Eggs = NamedTuple("Eggs", [("a", int), ("b", str)])
          Spam = TypedDict("Spam", {"a": int, "b": str})

          assert Bar.__bases__ == (Foo, float)
          assert get_original_bases(Bar) == (Foo[int], float)

          assert Baz.__bases__ == (list,)
          assert get_original_bases(Baz) == (list[str],)

          assert Eggs.__bases__ == (tuple,)
          assert get_original_bases(Eggs) == (NamedTuple,)

          assert Spam.__bases__ == (dict,)
          assert get_original_bases(Spam) == (TypedDict,)

          assert int.__bases__ == (object,)
          assert get_original_bases(int) == (object,)

     Added in version 3.12.

Vedi anche
..........

PEP 560(4) - Core support for typing module and generic types

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3115/

   (2) https://peps.python.org/pep-0560/

   (3) https://peps.python.org/pep-0560/

   (4) https://peps.python.org/pep-0560/


File: python.info,  Node: Standard Interpreter Types,  Next: Additional Utility Classes and Functions,  Prev: Dynamic Type Creation,  Up: types — Dynamic type creation and names for built-in types

5.8.10.2 Standard Interpreter Types
...................................

This module provides names for many of the types that are required to
implement a Python interpreter.  It deliberately avoids including some
of the types that arise only incidentally during processing such as the
‘listiterator’ type.

Typical use of these names is for *note isinstance(): 2ad. or *note
issubclass(): 9c6. checks.

If you instantiate any of these types, note that signatures may vary
between Python versions.

Standard names are defined for the following types:

 -- Dati: types.NoneType

     The type of *note None: 886.

     Added in version 3.10.

 -- Dati: types.FunctionType
 -- Dati: types.LambdaType

     The type of user-defined functions and functions created by *note
     lambda: 14a5. expressions.

     Raises an *note auditing event: 1c56. ‘function.__new__’ with
     argument ‘code’.

     The audit event only occurs for direct instantiation of function
     objects, and is not raised for normal compilation.

 -- Dati: types.GeneratorType

     The type of *note generator: 1263.-iterator objects, created by
     generator functions.

 -- Dati: types.CoroutineType

     The type of *note coroutine: 6ba. objects, created by *note async
     def: 7ee. functions.

     Added in version 3.5.

 -- Dati: types.AsyncGeneratorType

     The type of *note asynchronous generator: 2476.-iterator objects,
     created by asynchronous generator functions.

     Added in version 3.6.

 -- Classe: types.CodeType (**kwargs)

     The type of *note code objects: 4e7. such as returned by *note
     compile(): 4b2.

     Raises an *note auditing event: 1c56. ‘code.__new__’ with arguments
     ‘code’, ‘filename’, ‘name’, ‘argcount’, ‘posonlyargcount’,
     ‘kwonlyargcount’, ‘nlocals’, ‘stacksize’, ‘flags’.

     Note that the audited arguments may not match the names or
     positions required by the initializer.  The audit event only occurs
     for direct instantiation of code objects, and is not raised for
     normal compilation.

 -- Dati: types.CellType

     The type for cell objects: such objects are used as containers for
     a function’s *note closure variables: 187b.

     Added in version 3.8.

 -- Dati: types.MethodType

     The type of methods of user-defined class instances.

 -- Dati: types.BuiltinFunctionType
 -- Dati: types.BuiltinMethodType

     The type of built-in functions like *note len(): 841. or *note
     sys.exit(): 277, and methods of built-in classes.  (Here, the term
     «built-in» means «written in C».)

 -- Dati: types.WrapperDescriptorType

     The type of methods of some built-in data types and base classes
     such as *note object.__init__(): 8c0. or *note object.__lt__():
     14a8.

     Added in version 3.7.

 -- Dati: types.MethodWrapperType

     The type of 'bound' methods of some built-in data types and base
     classes.  For example it is the type of ‘object().__str__’.

     Added in version 3.7.

 -- Dati: types.NotImplementedType

     The type of *note NotImplemented: 1a2.

     Added in version 3.10.

 -- Dati: types.MethodDescriptorType

     The type of methods of some built-in data types such as *note
     str.join(): 25e8.

     Added in version 3.7.

 -- Dati: types.ClassMethodDescriptorType

     The type of 'unbound' class methods of some built-in data types
     such as ‘dict.__dict__['fromkeys']’.

     Added in version 3.7.

 -- Classe: types.ModuleType (name, doc=None)

     The type of *note modules: 19c6.  The constructor takes the name of
     the module to be created and optionally its *note docstring: 22d5.

     Vedi anche
     ..........

     *note Documentation on module objects: 2345.

          Provides details on the special attributes that can be found
          on instances of ‘ModuleType’.

     *note importlib.util.module_from_spec(): 1015.

          Modules created using the ‘ModuleType’ constructor are created
          with many of their special attributes unset or set to default
          values.  ‘module_from_spec()’ provides a more robust way of
          creating ‘ModuleType’ instances which ensures the various
          attributes are set appropriately.

 -- Dati: types.EllipsisType

     The type of *note Ellipsis: 2311.

     Added in version 3.10.

 -- Classe: types.GenericAlias (t_origin, t_args)

     The type of *note parameterized generics: 8c2. such as ‘list[int]’.

     ‘t_origin’ should be a non-parameterized generic class, such as
     ‘list’, ‘tuple’ or ‘dict’.  ‘t_args’ should be a *note tuple: 614.
     (possibly of length 1) of types which parameterize ‘t_origin’:

          >>> from types import GenericAlias

          >>> list[int] == GenericAlias(list, (int,))
          True
          >>> dict[str, int] == GenericAlias(dict, (str, int))
          True

     Added in version 3.9.

     Cambiato nella versione 3.9.2: This type can now be subclassed.

     Vedi anche
     ..........

     *note Generic Alias Types: 8c2.

          In-depth documentation on instances of ‘types.GenericAlias’

     PEP 585(1) - Type Hinting Generics In Standard Collections

          Introducing the ‘types.GenericAlias’ class

 -- Classe: types.UnionType

     The type of *note union type expressions: 9c7.

     Added in version 3.10.

     Cambiato nella versione 3.14: This is now an alias for *note
     typing.Union: 2a8.

 -- Classe: types.TracebackType (tb_next, tb_frame, tb_lasti, tb_lineno)

     The type of traceback objects such as found in
     ‘sys.exception().__traceback__’.

     See *note the language reference: cee. for details of the available
     attributes and operations, and guidance on creating tracebacks
     dynamically.

 -- Dati: types.FrameType

     The type of *note frame objects: 8f0. such as found in *note
     tb.tb_frame: 2387. if ‘tb’ is a traceback object.

 -- Dati: types.GetSetDescriptorType

     The type of objects defined in extension modules with
     ‘PyGetSetDef’, such as *note FrameType.f_locals: 4a6. or
     ‘array.array.typecode’.  This type is used as descriptor for object
     attributes; it has the same purpose as the *note property: 4b4.
     type, but for classes defined in extension modules.

 -- Dati: types.MemberDescriptorType

     The type of objects defined in extension modules with
     ‘PyMemberDef’, such as ‘datetime.timedelta.days’.  This type is
     used as descriptor for simple C data members which use standard
     conversion functions; it has the same purpose as the *note
     property: 4b4. type, but for classes defined in extension modules.

     In addition, when a class is defined with a *note __slots__: 16f2.
     attribute, then for each slot, an instance of
     ‘MemberDescriptorType’ will be added as an attribute on the class.
     This allows the slot to appear in the class’s *note __dict__: e59.

     'Dettaglio dell’implementazione di CPython:' In other
     implementations of Python, this type may be identical to
     ‘GetSetDescriptorType’.

 -- Classe: types.MappingProxyType (mapping)

     Read-only proxy of a mapping.  It provides a dynamic view on the
     mapping’s entries, which means that when the mapping changes, the
     view reflects these changes.

     Added in version 3.3.

     Cambiato nella versione 3.9: Updated to support the new union (‘|’)
     operator from PEP 584(2), which simply delegates to the underlying
     mapping.

      -- Describe: key in proxy

          Return ‘True’ if the underlying mapping has a key 'key', else
          ‘False’.

      -- Describe: proxy[key]

          Return the item of the underlying mapping with key 'key'.
          Raises a *note KeyError: 5e7. if 'key' is not in the
          underlying mapping.

      -- Describe: iter(proxy)

          Return an iterator over the keys of the underlying mapping.
          This is a shortcut for ‘iter(proxy.keys())’.

      -- Describe: len(proxy)

          Return the number of items in the underlying mapping.

      -- Metodo: copy ()

          Return a shallow copy of the underlying mapping.

      -- Metodo: get (key[, default])

          Return the value for 'key' if 'key' is in the underlying
          mapping, else 'default'.  If 'default' is not given, it
          defaults to ‘None’, so that this method never raises a *note
          KeyError: 5e7.

      -- Metodo: items ()

          Return a new view of the underlying mapping’s items (‘(key,
          value)’ pairs).

      -- Metodo: keys ()

          Return a new view of the underlying mapping’s keys.

      -- Metodo: values ()

          Return a new view of the underlying mapping’s values.

      -- Describe: reversed(proxy)

          Return a reverse iterator over the keys of the underlying
          mapping.

          Added in version 3.9.

      -- Describe: hash(proxy)

          Return a hash of the underlying mapping.

          Added in version 3.12.

 -- Classe: types.CapsuleType

     The type of *note capsule objects: 29d7.

     Added in version 3.13.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0585/

   (2) https://peps.python.org/pep-0584/


File: python.info,  Node: Additional Utility Classes and Functions,  Next: Coroutine Utility Functions,  Prev: Standard Interpreter Types,  Up: types — Dynamic type creation and names for built-in types

5.8.10.3 Additional Utility Classes and Functions
.................................................

 -- Classe: types.SimpleNamespace

     A simple *note object: c80. subclass that provides attribute access
     to its namespace, as well as a meaningful repr.

     Unlike *note object: c80, with ‘SimpleNamespace’ you can add and
     remove attributes.

     *note SimpleNamespace: 4e6. objects may be initialized in the same
     way as *note dict: 183.: either with keyword arguments, with a
     single positional argument, or with both.  When initialized with
     keyword arguments, those are directly added to the underlying
     namespace.  Alternatively, when initialized with a positional
     argument, the underlying namespace will be updated with key-value
     pairs from that argument (either a mapping object or an *note
     iterable: 142f. object producing key-value pairs).  All such keys
     must be strings.

     The type is roughly equivalent to the following code:

          class SimpleNamespace:
              def __init__(self, mapping_or_iterable=(), /, **kwargs):
                  self.__dict__.update(mapping_or_iterable)
                  self.__dict__.update(kwargs)

              def __repr__(self):
                  items = (f"{k}={v!r}" for k, v in self.__dict__.items())
                  return "{}({})".format(type(self).__name__, ", ".join(items))

              def __eq__(self, other):
                  if isinstance(self, SimpleNamespace) and isinstance(other, SimpleNamespace):
                     return self.__dict__ == other.__dict__
                  return NotImplemented

     ‘SimpleNamespace’ may be useful as a replacement for ‘class NS:
     pass’.  However, for a structured record type use *note
     namedtuple(): 4e1. instead.

     ‘SimpleNamespace’ objects are supported by *note copy.replace():
     1c0.

     Added in version 3.3.

     Cambiato nella versione 3.9: Attribute order in the repr changed
     from alphabetical to insertion (like ‘dict’).

     Cambiato nella versione 3.13: Added support for an optional
     positional argument.

 -- Funzione: types.DynamicClassAttribute (fget=None, fset=None,
          fdel=None, doc=None)

     Route attribute access on a class to __getattr__.

     This is a descriptor, used to define attributes that act
     differently when accessed through an instance and through a class.
     Instance access remains normal, but access to an attribute through
     a class will be routed to the class’s __getattr__ method; this is
     done by raising AttributeError.

     This allows one to have properties active on an instance, and have
     virtual attributes on the class with the same name (see *note
     enum.Enum: 843. for an example).

     Added in version 3.4.


File: python.info,  Node: Coroutine Utility Functions,  Prev: Additional Utility Classes and Functions,  Up: types — Dynamic type creation and names for built-in types

5.8.10.4 Coroutine Utility Functions
....................................

 -- Funzione: types.coroutine (gen_func)

     This function transforms a *note generator: 1263. function into a
     *note coroutine function: f75. which returns a generator-based
     coroutine.  The generator-based coroutine is still a *note
     generator iterator: ddb, but is also considered to be a *note
     coroutine: 6ba. object and is *note awaitable: 4ca.  However, it
     may not necessarily implement the *note __await__(): f77. method.

     If 'gen_func' is a generator function, it will be modified
     in-place.

     If 'gen_func' is not a generator function, it will be wrapped.  If
     it returns an instance of *note collections.abc.Generator: fdd, the
     instance will be wrapped in an 'awaitable' proxy object.  All other
     types of objects will be returned as is.

     Added in version 3.5.


File: python.info,  Node: copy — Shallow and deep copy operations,  Next: pprint — Data pretty printer,  Prev: types — Dynamic type creation and names for built-in types,  Up: Data Types

5.8.11 ‘copy’ — Shallow and deep copy operations
------------------------------------------------

'Source code:' Lib/copy.py(1)

__________________________________________________________________

Assignment statements in Python do not copy objects, they create
bindings between a target and an object.  For collections that are
mutable or contain mutable items, a copy is sometimes needed so one can
change one copy without changing the other.  This module provides
generic shallow and deep copy operations (explained below).

Interface summary:

 -- Funzione: copy.copy (obj)

     Return a shallow copy of 'obj'.

 -- Funzione: copy.deepcopy (obj[, memo])

     Return a deep copy of 'obj'.

 -- Funzione: copy.replace (obj, /, **changes)

     Creates a new object of the same type as 'obj', replacing fields
     with values from 'changes'.

     Added in version 3.13.

 -- Eccezione: copy.Error

     Raised for module specific errors.
The difference between shallow and deep copying is only relevant for
compound objects (objects that contain other objects, like lists or
class instances):

   * A 'shallow copy' constructs a new compound object and then (to the
     extent possible) inserts 'references' into it to the objects found
     in the original.

   * A 'deep copy' constructs a new compound object and then,
     recursively, inserts 'copies' into it of the objects found in the
     original.

Two problems often exist with deep copy operations that don’t exist with
shallow copy operations:

   * Recursive objects (compound objects that, directly or indirectly,
     contain a reference to themselves) may cause a recursive loop.

   * Because deep copy copies everything it may copy too much, such as
     data which is intended to be shared between copies.

The *note deepcopy(): d67. function avoids these problems by:

   * keeping a ‘memo’ dictionary of objects already copied during the
     current copying pass; and

   * letting user-defined classes override the copying operation or the
     set of components copied.

This module does not copy types like module, method, stack trace, stack
frame, file, socket, window, or any similar types.  It does «copy»
functions and classes (shallow and deeply), by returning the original
object unchanged; this is compatible with the way these are treated by
the *note pickle: ab. module.

Shallow copies of dictionaries can be made using *note dict.copy(): dcb,
and of lists by assigning a slice of the entire list, for example,
‘copied_list = original_list[:]’.

Classes can use the same interfaces to control copying that they use to
control pickling.  See the description of module *note pickle: ab. for
information on these methods.  In fact, the *note copy: 29. module uses
the registered pickle functions from the *note copyreg: 2a. module.

In order for a class to define its own copy implementation, it can
define special methods *note __copy__(): 17c8. and *note __deepcopy__():
17c9.

 -- Metodo: object.__copy__ (self)

     Called to implement the shallow copy operation; no additional
     arguments are passed.

 -- Metodo: object.__deepcopy__ (self, memo)

     Called to implement the deep copy operation; it is passed one
     argument, the 'memo' dictionary.  If the ‘__deepcopy__’
     implementation needs to make a deep copy of a component, it should
     call the *note deepcopy(): d67. function with the component as
     first argument and the 'memo' dictionary as second argument.  The
     'memo' dictionary should be treated as an opaque object.

Function ‘copy.replace()’ is more limited than *note copy(): 758. and
*note deepcopy(): d67, and only supports named tuples created by *note
namedtuple(): 4e1, *note dataclasses: 33, and other classes which define
method *note __replace__(): 47d.

 -- Metodo: object.__replace__ (self, /, **changes)

     This method should create a new object of the same type, replacing
     fields with values from 'changes'.

     Added in version 3.13.

Vedi anche
..........

Module *note pickle: ab.

     Discussion of the special methods used to support object state
     retrieval and restoration.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/copy.py


File: python.info,  Node: pprint — Data pretty printer,  Next: reprlib — Alternate repr implementation,  Prev: copy — Shallow and deep copy operations,  Up: Data Types

5.8.12 ‘pprint’ — Data pretty printer
-------------------------------------

'Source code:' Lib/pprint.py(1)

__________________________________________________________________

The *note pprint: b3. module provides a capability to «pretty-print»
arbitrary Python data structures in a form which can be used as input to
the interpreter.  If the formatted structures include objects which are
not fundamental Python types, the representation may not be loadable.
This may be the case if objects such as files, sockets or classes are
included, as well as many other objects which are not representable as
Python literals.

The formatted representation keeps objects on a single line if it can,
and breaks them onto multiple lines if they don’t fit within the allowed
width, adjustable by the 'width' parameter defaulting to 80 characters.

Cambiato nella versione 3.9: Added support for pretty-printing *note
types.SimpleNamespace: 4e6.

Cambiato nella versione 3.10: Added support for pretty-printing *note
dataclasses.dataclass: 4e2.

* Menu:

* Functions: Functions<3>.
* PrettyPrinter Objects::
* Example: Example<3>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/pprint.py


File: python.info,  Node: Functions<3>,  Next: PrettyPrinter Objects,  Up: pprint — Data pretty printer

5.8.12.1 Functions
..................

 -- Funzione: pprint.pp (object, stream=None, indent=1, width=80,
          depth=None, *, compact=False, sort_dicts=False,
          underscore_numbers=False)

     Prints the formatted representation of 'object', followed by a
     newline.  This function may be used in the interactive interpreter
     instead of the *note print(): 1177. function for inspecting values.
     Tip: you can reassign ‘print = pprint.pp’ for use within a scope.


     Parametri:

        * ‘object’ – The object to be printed.

        * ‘stream’ (*note file-like object: 1794. | None) – A file-like
          object to which the output will be written by calling its
          ‘write()’ method.  If ‘None’ (the default), *note sys.stdout:
          ccf. is used.

        * ‘indent’ (*note int: 19b.) – The amount of indentation added
          for each nesting level.

        * ‘width’ (*note int: 19b.) – The desired maximum number of
          characters per line in the output.  If a structure cannot be
          formatted within the width constraint, a best effort will be
          made.

        * ‘depth’ (*note int: 19b.‘ | ’‘None’) – The number of nesting
          levels which may be printed.  If the data structure being
          printed is too deep, the next contained level is replaced by
          ‘...’.  If ‘None’ (the default), there is no constraint on the
          depth of the objects being formatted.

        * ‘compact’ (*note bool: 3c3.) – Control the way long *note
          sequences: 717. are formatted.  If ‘False’ (the default), each
          item of a sequence will be formatted on a separate line,
          otherwise as many items as will fit within the 'width' will be
          formatted on each output line.

        * ‘sort_dicts’ (*note bool: 3c3.) – If ‘True’, dictionaries will
          be formatted with their keys sorted, otherwise they will be
          displayed in insertion order (the default).

        * ‘underscore_numbers’ (*note bool: 3c3.) – If ‘True’, integers
          will be formatted with the ‘_’ character for a thousands
          separator, otherwise underscores are not displayed (the
          default).

          >>> import pprint
          >>> stuff = ['spam', 'eggs', 'lumberjack', 'knights', 'ni']
          >>> stuff.insert(0, stuff)
          >>> pprint.pp(stuff)
          [<Recursion on list with id=...>,
           'spam',
           'eggs',
           'lumberjack',
           'knights',
           'ni']

     Added in version 3.8.

 -- Funzione: pprint.pprint (object, stream=None, indent=1, width=80,
          depth=None, *, compact=False, sort_dicts=True,
          underscore_numbers=False)

     Alias for *note pp(): c1a. with 'sort_dicts' set to ‘True’ by
     default, which would automatically sort the dictionaries” keys, you
     might want to use *note pp(): c1a. instead where it is ‘False’ by
     default.

 -- Funzione: pprint.pformat (object, indent=1, width=80, depth=None, *,
          compact=False, sort_dicts=True, underscore_numbers=False)

     Return the formatted representation of 'object' as a string.
     'indent', 'width', 'depth', 'compact', 'sort_dicts' and
     'underscore_numbers' are passed to the *note PrettyPrinter: 1181.
     constructor as formatting parameters and their meanings are as
     described in the documentation above.

 -- Funzione: pprint.isreadable (object)

     Determine if the formatted representation of 'object' is
     «readable», or can be used to reconstruct the value using *note
     eval(): 4a4.  This always returns ‘False’ for recursive objects.

          >>> pprint.isreadable(stuff)
          False

 -- Funzione: pprint.isrecursive (object)

     Determine if 'object' requires a recursive representation.  This
     function is subject to the same limitations as noted in *note
     saferepr(): 29e5. below and may raise an *note RecursionError: f6a.
     if it fails to detect a recursive object.

 -- Funzione: pprint.saferepr (object)

     Return a string representation of 'object', protected against
     recursion in some common data structures, namely instances of *note
     dict: 183, *note list: 24d. and *note tuple: 614. or subclasses
     whose ‘__repr__’ has not been overridden.  If the representation of
     object exposes a recursive entry, the recursive reference will be
     represented as ‘<Recursion on typename with id=number>’.  The
     representation is not otherwise formatted.

          >>> pprint.saferepr(stuff)
          "[<Recursion on list with id=...>, 'spam', 'eggs', 'lumberjack', 'knights', 'ni']"


File: python.info,  Node: PrettyPrinter Objects,  Next: Example<3>,  Prev: Functions<3>,  Up: pprint — Data pretty printer

5.8.12.2 PrettyPrinter Objects
..............................

 -- Classe: pprint.PrettyPrinter (indent=1, width=80, depth=None,
          stream=None, *, compact=False, sort_dicts=True,
          underscore_numbers=False)

     Construct a *note PrettyPrinter: 1181. instance.

     Arguments have the same meaning as for *note pp(): c1a.  Note that
     they are in a different order, and that 'sort_dicts' defaults to
     ‘True’.

          >>> import pprint
          >>> stuff = ['spam', 'eggs', 'lumberjack', 'knights', 'ni']
          >>> stuff.insert(0, stuff[:])
          >>> pp = pprint.PrettyPrinter(indent=4)
          >>> pp.pprint(stuff)
          [   ['spam', 'eggs', 'lumberjack', 'knights', 'ni'],
              'spam',
              'eggs',
              'lumberjack',
              'knights',
              'ni']
          >>> pp = pprint.PrettyPrinter(width=41, compact=True)
          >>> pp.pprint(stuff)
          [['spam', 'eggs', 'lumberjack',
            'knights', 'ni'],
           'spam', 'eggs', 'lumberjack', 'knights',
           'ni']
          >>> tup = ('spam', ('eggs', ('lumberjack', ('knights', ('ni', ('dead',
          ... ('parrot', ('fresh fruit',))))))))
          >>> pp = pprint.PrettyPrinter(depth=6)
          >>> pp.pprint(tup)
          ('spam', ('eggs', ('lumberjack', ('knights', ('ni', ('dead', (...)))))))

     Cambiato nella versione 3.4: Added the 'compact' parameter.

     Cambiato nella versione 3.8: Added the 'sort_dicts' parameter.

     Cambiato nella versione 3.10: Added the 'underscore_numbers'
     parameter.

     Cambiato nella versione 3.11: No longer attempts to write to
     ‘sys.stdout’ if it is ‘None’.

*note PrettyPrinter: 1181. instances have the following methods:

 -- Metodo: PrettyPrinter.pformat (object)

     Return the formatted representation of 'object'.  This takes into
     account the options passed to the *note PrettyPrinter: 1181.
     constructor.

 -- Metodo: PrettyPrinter.pprint (object)

     Print the formatted representation of 'object' on the configured
     stream, followed by a newline.

The following methods provide the implementations for the corresponding
functions of the same names.  Using these methods on an instance is
slightly more efficient since new *note PrettyPrinter: 1181. objects
don’t need to be created.

 -- Metodo: PrettyPrinter.isreadable (object)

     Determine if the formatted representation of the object is
     «readable,» or can be used to reconstruct the value using *note
     eval(): 4a4.  Note that this returns ‘False’ for recursive objects.
     If the 'depth' parameter of the *note PrettyPrinter: 1181. is set
     and the object is deeper than allowed, this returns ‘False’.

 -- Metodo: PrettyPrinter.isrecursive (object)

     Determine if the object requires a recursive representation.

This method is provided as a hook to allow subclasses to modify the way
objects are converted to strings.  The default implementation uses the
internals of the *note saferepr(): 29e5. implementation.

 -- Metodo: PrettyPrinter.format (object, context, maxlevels, level)

     Returns three values: the formatted version of 'object' as a
     string, a flag indicating whether the result is readable, and a
     flag indicating whether recursion was detected.  The first argument
     is the object to be presented.  The second is a dictionary which
     contains the *note id(): 162a. of objects that are part of the
     current presentation context (direct and indirect containers for
     'object' that are affecting the presentation) as the keys; if an
     object needs to be presented which is already represented in
     'context', the third return value should be ‘True’.  Recursive
     calls to the *note format(): 1ccf. method should add additional
     entries for containers to this dictionary.  The third argument,
     'maxlevels', gives the requested limit to recursion; this will be
     ‘0’ if there is no requested limit.  This argument should be passed
     unmodified to recursive calls.  The fourth argument, 'level', gives
     the current level; recursive calls should be passed a value less
     than that of the current call.


File: python.info,  Node: Example<3>,  Prev: PrettyPrinter Objects,  Up: pprint — Data pretty printer

5.8.12.3 Example
................

To demonstrate several uses of the *note pp(): c1a. function and its
parameters, let’s fetch information about a project from PyPI(1):

     >>> import json
     >>> import pprint
     >>> from urllib.request import urlopen
     >>> with urlopen('https://pypi.org/pypi/sampleproject/1.2.0/json') as resp:
     ...     project_info = json.load(resp)['info']

In its basic form, *note pp(): c1a. shows the whole object:

     >>> pprint.pp(project_info)
     {'author': 'The Python Packaging Authority',
      'author_email': 'pypa-dev@googlegroups.com',
      'bugtrack_url': None,
      'classifiers': ['Development Status :: 3 - Alpha',
                      'Intended Audience :: Developers',
                      'License :: OSI Approved :: MIT License',
                      'Programming Language :: Python :: 2',
                      'Programming Language :: Python :: 2.6',
                      'Programming Language :: Python :: 2.7',
                      'Programming Language :: Python :: 3',
                      'Programming Language :: Python :: 3.2',
                      'Programming Language :: Python :: 3.3',
                      'Programming Language :: Python :: 3.4',
                      'Topic :: Software Development :: Build Tools'],
      'description': 'A sample Python project\n'
                     '=======================\n'
                     '\n'
                     'This is the description file for the project.\n'
                     '\n'
                     'The file should use UTF-8 encoding and be written using '
                     'ReStructured Text. It\n'
                     'will be used to generate the project webpage on PyPI, and '
                     'should be written for\n'
                     'that purpose.\n'
                     '\n'
                     'Typical contents for this file would include an overview of '
                     'the project, basic\n'
                     'usage examples, etc. Generally, including the project '
                     'changelog in here is not\n'
                     'a good idea, although a simple "What\'s New" section for the '
                     'most recent version\n'
                     'may be appropriate.',
      'description_content_type': None,
      'docs_url': None,
      'download_url': 'UNKNOWN',
      'downloads': {'last_day': -1, 'last_month': -1, 'last_week': -1},
      'home_page': 'https://github.com/pypa/sampleproject',
      'keywords': 'sample setuptools development',
      'license': 'MIT',
      'maintainer': None,
      'maintainer_email': None,
      'name': 'sampleproject',
      'package_url': 'https://pypi.org/project/sampleproject/',
      'platform': 'UNKNOWN',
      'project_url': 'https://pypi.org/project/sampleproject/',
      'project_urls': {'Download': 'UNKNOWN',
                       'Homepage': 'https://github.com/pypa/sampleproject'},
      'release_url': 'https://pypi.org/project/sampleproject/1.2.0/',
      'requires_dist': None,
      'requires_python': None,
      'summary': 'A sample Python project',
      'version': '1.2.0'}

The result can be limited to a certain 'depth' (ellipsis is used for
deeper contents):

     >>> pprint.pp(project_info, depth=1)
     {'author': 'The Python Packaging Authority',
      'author_email': 'pypa-dev@googlegroups.com',
      'bugtrack_url': None,
      'classifiers': [...],
      'description': 'A sample Python project\n'
                     '=======================\n'
                     '\n'
                     'This is the description file for the project.\n'
                     '\n'
                     'The file should use UTF-8 encoding and be written using '
                     'ReStructured Text. It\n'
                     'will be used to generate the project webpage on PyPI, and '
                     'should be written for\n'
                     'that purpose.\n'
                     '\n'
                     'Typical contents for this file would include an overview of '
                     'the project, basic\n'
                     'usage examples, etc. Generally, including the project '
                     'changelog in here is not\n'
                     'a good idea, although a simple "What\'s New" section for the '
                     'most recent version\n'
                     'may be appropriate.',
      'description_content_type': None,
      'docs_url': None,
      'download_url': 'UNKNOWN',
      'downloads': {...},
      'home_page': 'https://github.com/pypa/sampleproject',
      'keywords': 'sample setuptools development',
      'license': 'MIT',
      'maintainer': None,
      'maintainer_email': None,
      'name': 'sampleproject',
      'package_url': 'https://pypi.org/project/sampleproject/',
      'platform': 'UNKNOWN',
      'project_url': 'https://pypi.org/project/sampleproject/',
      'project_urls': {...},
      'release_url': 'https://pypi.org/project/sampleproject/1.2.0/',
      'requires_dist': None,
      'requires_python': None,
      'summary': 'A sample Python project',
      'version': '1.2.0'}

Additionally, maximum character 'width' can be suggested.  If a long
object cannot be split, the specified width will be exceeded:

     >>> pprint.pp(project_info, depth=1, width=60)
     {'author': 'The Python Packaging Authority',
      'author_email': 'pypa-dev@googlegroups.com',
      'bugtrack_url': None,
      'classifiers': [...],
      'description': 'A sample Python project\n'
                     '=======================\n'
                     '\n'
                     'This is the description file for the '
                     'project.\n'
                     '\n'
                     'The file should use UTF-8 encoding and be '
                     'written using ReStructured Text. It\n'
                     'will be used to generate the project '
                     'webpage on PyPI, and should be written '
                     'for\n'
                     'that purpose.\n'
                     '\n'
                     'Typical contents for this file would '
                     'include an overview of the project, '
                     'basic\n'
                     'usage examples, etc. Generally, including '
                     'the project changelog in here is not\n'
                     'a good idea, although a simple "What\'s '
                     'New" section for the most recent version\n'
                     'may be appropriate.',
      'description_content_type': None,
      'docs_url': None,
      'download_url': 'UNKNOWN',
      'downloads': {...},
      'home_page': 'https://github.com/pypa/sampleproject',
      'keywords': 'sample setuptools development',
      'license': 'MIT',
      'maintainer': None,
      'maintainer_email': None,
      'name': 'sampleproject',
      'package_url': 'https://pypi.org/project/sampleproject/',
      'platform': 'UNKNOWN',
      'project_url': 'https://pypi.org/project/sampleproject/',
      'project_urls': {...},
      'release_url': 'https://pypi.org/project/sampleproject/1.2.0/',
      'requires_dist': None,
      'requires_python': None,
      'summary': 'A sample Python project',
      'version': '1.2.0'}

   ---------- Footnotes ----------

   (1) https://pypi.org


File: python.info,  Node: reprlib — Alternate repr implementation,  Next: enum — Support for enumerations,  Prev: pprint — Data pretty printer,  Up: Data Types

5.8.13 ‘reprlib’ — Alternate ‘repr()’ implementation
----------------------------------------------------

'Source code:' Lib/reprlib.py(1)

__________________________________________________________________

The ‘reprlib’ module provides a means for producing object
representations with limits on the size of the resulting strings.  This
is used in the Python debugger and may be useful in other contexts as
well.

This module provides a class, an instance, and a function:

 -- Classe: reprlib.Repr (*, maxlevel=6, maxtuple=6, maxlist=6,
          maxarray=5, maxdict=4, maxset=6, maxfrozenset=6, maxdeque=6,
          maxstring=30, maxlong=40, maxother=30, fillvalue='...',
          indent=None)

     Class which provides formatting services useful in implementing
     functions similar to the built-in *note repr(): 1c1.; size limits
     for different object types are added to avoid the generation of
     representations which are excessively long.

     The keyword arguments of the constructor can be used as a shortcut
     to set the attributes of the *note Repr: 29f1. instance.  Which
     means that the following initialization:

          aRepr = reprlib.Repr(maxlevel=3)

     Is equivalent to:

          aRepr = reprlib.Repr()
          aRepr.maxlevel = 3

     See section *note Repr Objects: 29f2. for more information about
     *note Repr: 29f1. attributes.

     Cambiato nella versione 3.12: Allow attributes to be set via
     keyword arguments.

 -- Dati: reprlib.aRepr

     This is an instance of *note Repr: 29f1. which is used to provide
     the *note repr(): 29f4. function described below.  Changing the
     attributes of this object will affect the size limits used by *note
     repr(): 29f4. and the Python debugger.

 -- Funzione: reprlib.repr (obj)

     This is the *note repr(): 29f5. method of ‘aRepr’.  It returns a
     string similar to that returned by the built-in function of the
     same name, but with limits on most sizes.

In addition to size-limiting tools, the module also provides a decorator
for detecting recursive calls to *note __repr__(): 830. and substituting
a placeholder string instead.

 -- Funzione: @reprlib.recursive_repr (fillvalue='...')

     Decorator for *note __repr__(): 830. methods to detect recursive
     calls within the same thread.  If a recursive call is made, the
     'fillvalue' is returned, otherwise, the usual ‘__repr__()’ call is
     made.  For example:

          >>> from reprlib import recursive_repr
          >>> class MyList(list):
          ...     @recursive_repr()
          ...     def __repr__(self):
          ...         return '<' + '|'.join(map(repr, self)) + '>'
          ...
          >>> m = MyList('abc')
          >>> m.append(m)
          >>> m.append('x')
          >>> print(m)
          <'a'|'b'|'c'|...|'x'>

     Added in version 3.2.

* Menu:

* Repr Objects::
* Subclassing Repr Objects::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/reprlib.py


File: python.info,  Node: Repr Objects,  Next: Subclassing Repr Objects,  Up: reprlib — Alternate repr implementation

5.8.13.1 Repr Objects
.....................

*note Repr: 29f1. instances provide several attributes which can be used
to provide size limits for the representations of different object
types, and methods which format specific object types.

 -- Attributo: Repr.fillvalue

     This string is displayed for recursive references.  It defaults to
     ‘...’.

     Added in version 3.11.

 -- Attributo: Repr.maxlevel

     Depth limit on the creation of recursive representations.  The
     default is ‘6’.

 -- Attributo: Repr.maxdict
 -- Attributo: Repr.maxlist
 -- Attributo: Repr.maxtuple
 -- Attributo: Repr.maxset
 -- Attributo: Repr.maxfrozenset
 -- Attributo: Repr.maxdeque
 -- Attributo: Repr.maxarray

     Limits on the number of entries represented for the named object
     type.  The default is ‘4’ for *note maxdict: 29f9, ‘5’ for *note
     maxarray: 29ff, and ‘6’ for the others.

 -- Attributo: Repr.maxlong

     Maximum number of characters in the representation for an integer.
     Digits are dropped from the middle.  The default is ‘40’.

 -- Attributo: Repr.maxstring

     Limit on the number of characters in the representation of the
     string.  Note that the «normal» representation of the string is
     used as the character source: if escape sequences are needed in the
     representation, these may be mangled when the representation is
     shortened.  The default is ‘30’.

 -- Attributo: Repr.maxother

     This limit is used to control the size of object types for which no
     specific formatting method is available on the *note Repr: 29f1.
     object.  It is applied in a similar manner as *note maxstring:
     2a01.  The default is ‘20’.

 -- Attributo: Repr.indent

     If this attribute is set to ‘None’ (the default), the output is
     formatted with no line breaks or indentation, like the standard
     *note repr(): 1c1.  For example:

          >>> example = [
          ...     1, 'spam', {'a': 2, 'b': 'spam eggs', 'c': {3: 4.5, 6: []}}, 'ham']
          >>> import reprlib
          >>> aRepr = reprlib.Repr()
          >>> print(aRepr.repr(example))
          [1, 'spam', {'a': 2, 'b': 'spam eggs', 'c': {3: 4.5, 6: []}}, 'ham']

     If *note indent: 2a03. is set to a string, each recursion level is
     placed on its own line, indented by that string:

          >>> aRepr.indent = '-->'
          >>> print(aRepr.repr(example))
          [
          -->1,
          -->'spam',
          -->{
          -->-->'a': 2,
          -->-->'b': 'spam eggs',
          -->-->'c': {
          -->-->-->3: 4.5,
          -->-->-->6: [],
          -->-->},
          -->},
          -->'ham',
          ]

     Setting *note indent: 2a03. to a positive integer value behaves as
     if it was set to a string with that number of spaces:

          >>> aRepr.indent = 4
          >>> print(aRepr.repr(example))
          [
              1,
              'spam',
              {
                  'a': 2,
                  'b': 'spam eggs',
                  'c': {
                      3: 4.5,
                      6: [],
                  },
              },
              'ham',
          ]

     Added in version 3.12.

 -- Metodo: Repr.repr (obj)

     The equivalent to the built-in *note repr(): 1c1. that uses the
     formatting imposed by the instance.

 -- Metodo: Repr.repr1 (obj, level)

     Recursive implementation used by *note repr(): 29f5.  This uses the
     type of 'obj' to determine which formatting method to call, passing
     it 'obj' and 'level'.  The type-specific methods should call *note
     repr1(): 2a04. to perform recursive formatting, with ‘level - 1’
     for the value of 'level' in the recursive call.

 -- Metodo: Repr.repr_TYPE (obj, level)

     Formatting methods for specific types are implemented as methods
     with a name based on the type name.  In the method name, 'TYPE' is
     replaced by ‘'_'.join(type(obj).__name__.split())’.  Dispatch to
     these methods is handled by *note repr1(): 2a04.  Type-specific
     methods which need to recursively format a value should call
     ‘self.repr1(subobj, level - 1)’.


File: python.info,  Node: Subclassing Repr Objects,  Prev: Repr Objects,  Up: reprlib — Alternate repr implementation

5.8.13.2 Subclassing Repr Objects
.................................

The use of dynamic dispatching by *note Repr.repr1(): 2a04. allows
subclasses of *note Repr: 29f1. to add support for additional built-in
object types or to modify the handling of types already supported.  This
example shows how special support for file objects could be added:

     import reprlib
     import sys

     class MyRepr(reprlib.Repr):

         def repr_TextIOWrapper(self, obj, level):
             if obj.name in {'<stdin>', '<stdout>', '<stderr>'}:
                 return obj.name
             return repr(obj)

     aRepr = MyRepr()
     print(aRepr.repr(sys.stdin))         # prints '<stdin>'

     <stdin>


File: python.info,  Node: enum — Support for enumerations,  Next: graphlib — Functionality to operate with graph-like structures,  Prev: reprlib — Alternate repr implementation,  Up: Data Types

5.8.14 ‘enum’ — Support for enumerations
----------------------------------------

Added in version 3.4.

'Source code:' Lib/enum.py(1)

Important
.........

This page contains the API reference information.  For tutorial
information and discussion of more advanced topics, see

   * *note Basic Tutorial: 2a0a.

   * *note Advanced Tutorial: 2a0b.

   * *note Enum Cookbook: 2a0c.

__________________________________________________________________

An enumeration:

   * is a set of symbolic names (members) bound to unique values

   * can be iterated over to return its canonical (i.e.  non-alias)
     members in definition order

   * uses 'call' syntax to return members by value

   * uses 'index' syntax to return members by name

Enumerations are created either by using *note class: 14df. syntax, or
by using function-call syntax:

     >>> from enum import Enum

     >>> # class syntax
     >>> class Color(Enum):
     ...     RED = 1
     ...     GREEN = 2
     ...     BLUE = 3

     >>> # functional syntax
     >>> Color = Enum('Color', [('RED', 1), ('GREEN', 2), ('BLUE', 3)])

Even though we can use *note class: 14df. syntax to create Enums, Enums
are not normal Python classes.  See *note How are Enums different?:
2a0d. for more details.

     Nota: Nomenclature

        - The class ‘Color’ is an 'enumeration' (or 'enum')

        - The attributes ‘Color.RED’, ‘Color.GREEN’, etc., are
          'enumeration members' (or 'members') and are functionally
          constants.

        - The enum members have 'names' and 'values' (the name of
          ‘Color.RED’ is ‘RED’, the value of ‘Color.BLUE’ is ‘3’, etc.)

__________________________________________________________________

* Menu:

* Module Contents: Module Contents<2>.
* Data Types: Data Types<2>.
* Utilities and Decorators::
* Notes::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/enum.py


File: python.info,  Node: Module Contents<2>,  Next: Data Types<2>,  Up: enum — Support for enumerations

5.8.14.1 Module Contents
........................

     *note EnumType: 4f8.

          The ‘type’ for Enum and its subclasses.

     *note Enum: 843.

          Base class for creating enumerated constants.

     *note IntEnum: edd.

          Base class for creating enumerated constants that are also
          subclasses of *note int: 19b.  (*note Notes: 2a0f.)

     *note StrEnum: 82e.

          Base class for creating enumerated constants that are also
          subclasses of *note str: 169.  (*note Notes: 2a0f.)

     *note Flag: 836.

          Base class for creating enumerated constants that can be
          combined using the bitwise operations without losing their
          *note Flag: 836. membership.

     *note IntFlag: e9c.

          Base class for creating enumerated constants that can be
          combined using the bitwise operators without losing their
          *note IntFlag: e9c. membership.  *note IntFlag: e9c. members
          are also subclasses of *note int: 19b.  (*note Notes: 2a0f.)

     *note ReprEnum: 82f.

          Used by *note IntEnum: edd, *note StrEnum: 82e, and *note
          IntFlag: e9c. to keep the *note str(): 169. of the mixed-in
          type.

     *note EnumCheck: 839.

          An enumeration with the values ‘CONTINUOUS’, ‘NAMED_FLAGS’,
          and ‘UNIQUE’, for use with *note verify(): 838. to ensure
          various constraints are met by a given enumeration.

     *note FlagBoundary: 837.

          An enumeration with the values ‘STRICT’, ‘CONFORM’, ‘EJECT’,
          and ‘KEEP’ which allows for more fine-grained control over how
          invalid values are dealt with in an enumeration.

     *note EnumDict: 4f7.

          A subclass of *note dict: 183. for use when subclassing *note
          EnumType: 4f8.

     *note auto: e9d.

          Instances are replaced with an appropriate value for Enum
          members.  *note StrEnum: 82e. defaults to the lower-cased
          version of the member name, while other Enums default to 1 and
          increase from there.

     *note property(): 83c.

          Allows *note Enum: 843. members to have attributes without
          conflicting with member names.  The ‘value’ and ‘name’
          attributes are implemented this way.

     *note unique(): 2a10.

          Enum class decorator that ensures only one name is bound to
          any one value.

     *note verify(): 838.

          Enum class decorator that checks user-selectable constraints
          on an enumeration.

     *note member(): 83a.

          Make ‘obj’ a member.  Can be used as a decorator.

     *note nonmember(): 83b.

          Do not make ‘obj’ a member.  Can be used as a decorator.

     *note global_enum(): 83e.

          Modify the *note str(): 169. and *note repr(): 1c1. of an enum
          to show its members as belonging to the module instead of its
          class, and export the enum members to the global namespace.

     *note show_flag_values(): 2a11.

          Return a list of all power-of-two integers contained in a
          flag.

     *note enum.bin(): 1775.

          Like built-in *note bin(): 14b0, except negative values are
          represented in two’s complement, and the leading bit always
          indicates sign (‘0’ implies positive, ‘1’ implies negative).

Added in version 3.6: ‘Flag’, ‘IntFlag’, ‘auto’

Added in version 3.11: ‘StrEnum’, ‘EnumCheck’, ‘ReprEnum’,
‘FlagBoundary’, ‘property’, ‘member’, ‘nonmember’, ‘global_enum’,
‘show_flag_values’

Added in version 3.13: ‘EnumDict’

__________________________________________________________________


File: python.info,  Node: Data Types<2>,  Next: Utilities and Decorators,  Prev: Module Contents<2>,  Up: enum — Support for enumerations

5.8.14.2 Data Types
...................

 -- Classe: enum.EnumType

     'EnumType' is the *note metaclass: 23b6. for 'enum' enumerations.
     It is possible to subclass 'EnumType' – see *note Subclassing
     EnumType: 2a13. for details.

     ‘EnumType’ is responsible for setting the correct ‘__repr__()’,
     ‘__str__()’, ‘__format__()’, and ‘__reduce__()’ methods on the
     final 'enum', as well as creating the enum members, properly
     handling duplicates, providing iteration over the enum class, etc.

     Added in version 3.11: Before 3.11 ‘EnumType’ was called
     ‘EnumMeta’, which is still available as an alias.

      -- Metodo: __call__ (cls, value, names=None, *, module=None,
               qualname=None, type=None, start=1, boundary=None)

          This method is called in two different ways:

             * to look up an existing member:


                    cls: The enum class being called.


                    value: The value to lookup.

             * to use the ‘cls’ enum to create a new enum (only if the
               existing enum does not have any members):


                    cls: The enum class being called.


                    value: The name of the new Enum to create.


                    names: The names/values of the members for the new
                    Enum.


                    module: The name of the module the new Enum is
                    created in.


                    qualname: The actual location in the module where
                    this Enum can be found.


                    type: A mix-in type for the new Enum.


                    start: The first integer value for the Enum (used by
                    *note auto: e9d.).


                    boundary: How to handle out-of-range values from bit
                    operations (*note Flag: 836. only).

      -- Metodo: __contains__ (cls, member)

          Returns ‘True’ if member belongs to the ‘cls’:

               >>> some_var = Color.RED
               >>> some_var in Color
               True
               >>> Color.RED.value in Color
               True

          Cambiato nella versione 3.12: Before Python 3.12, a
          ‘TypeError’ is raised if a non-Enum-member is used in a
          containment check.

      -- Metodo: __dir__ (cls)

          Returns ‘['__class__', '__doc__', '__members__',
          '__module__']’ and the names of the members in 'cls':

               >>> dir(Color)
               ['BLUE', 'GREEN', 'RED', '__class__', '__contains__', '__doc__', '__getitem__', '__init_subclass__', '__iter__', '__len__', '__members__', '__module__', '__name__', '__qualname__']

      -- Metodo: __getitem__ (cls, name)

          Returns the Enum member in 'cls' matching 'name', or raises a
          *note KeyError: 5e7.:

               >>> Color['BLUE']
               <Color.BLUE: 3>

      -- Metodo: __iter__ (cls)

          Returns each member in 'cls' in definition order:

               >>> list(Color)
               [<Color.RED: 1>, <Color.GREEN: 2>, <Color.BLUE: 3>]

      -- Metodo: __len__ (cls)

          Returns the number of member in 'cls':

               >>> len(Color)
               3

      -- Attributo: __members__

          Returns a mapping of every enum name to its member, including
          aliases

      -- Metodo: __reversed__ (cls)

          Returns each member in 'cls' in reverse definition order:

               >>> list(reversed(Color))
               [<Color.BLUE: 3>, <Color.GREEN: 2>, <Color.RED: 1>]

 -- Classe: enum.Enum

     'Enum' is the base class for all 'enum' enumerations.

      -- Attributo: name

          The name used to define the ‘Enum’ member:

               >>> Color.BLUE.name
               'BLUE'

      -- Attributo: value

          The value given to the ‘Enum’ member:

               >>> Color.RED.value
               1

          Value of the member, can be set in *note __new__(): 2a1e.

               Nota: Enum member values

               Member values can be anything: *note int: 19b, *note str:
               169, etc.  If the exact value is unimportant you may use
               *note auto: e9d. instances and an appropriate value will
               be chosen for you.  See *note auto: e9d. for the details.

               While mutable/unhashable values, such as *note dict: 183,
               *note list: 24d. or a mutable *note dataclass: 4e2, can
               be used, they will have a quadratic performance impact
               during creation relative to the total number of
               mutable/unhashable values in the enum.

      -- Attributo: _name_

          Name of the member.

      -- Attributo: _value_

          Value of the member, can be set in *note __new__(): 2a1e.

      -- Attributo: _order_

          No longer used, kept for backward compatibility.  (class
          attribute, removed during class creation).

      -- Attributo: _ignore_

          ‘_ignore_’ is only used during creation and is removed from
          the enumeration once creation is complete.

          ‘_ignore_’ is a list of names that will not become members,
          and whose names will also be removed from the completed
          enumeration.  See *note TimePeriod: 2a23. for an example.

      -- Metodo: __dir__ (self)

          Returns ‘['__class__', '__doc__', '__module__', 'name',
          'value']’ and any public methods defined on 'self.__class__':

               >>> from enum import Enum
               >>> from datetime import date
               >>> class Weekday(Enum):
               ...     MONDAY = 1
               ...     TUESDAY = 2
               ...     WEDNESDAY = 3
               ...     THURSDAY = 4
               ...     FRIDAY = 5
               ...     SATURDAY = 6
               ...     SUNDAY = 7
               ...     @classmethod
               ...     def today(cls):
               ...         print('today is %s' % cls(date.today().isoweekday()).name)
               ...
               >>> dir(Weekday.SATURDAY)
               ['__class__', '__doc__', '__eq__', '__hash__', '__module__', 'name', 'today', 'value']

      -- Metodo: _generate_next_value_ (name, start, count, last_values)


               name: The name of the member being defined (e.g.  “RED”).


               start: The start value for the Enum; the default is 1.


               count: The number of members currently defined, not
               including this one.


               last_values: A list of the previous values.

          A 'staticmethod' that is used to determine the next value
          returned by *note auto: e9d.:

               >>> from enum import auto, Enum
               >>> class PowersOfThree(Enum):
               ...     @staticmethod
               ...     def _generate_next_value_(name, start, count, last_values):
               ...         return 3 ** (count + 1)
               ...     FIRST = auto()
               ...     SECOND = auto()
               ...
               >>> PowersOfThree.SECOND.value
               9

      -- Metodo: __init__ (self, *args, **kwds)

          By default, does nothing.  If multiple values are given in the
          member assignment, those values become separate arguments to
          ‘__init__’; e.g.

               >>> from enum import Enum
               >>> class Weekday(Enum):
               ...     MONDAY = 1, 'Mon'

          ‘Weekday.__init__()’ would be called as
          ‘Weekday.__init__(self, 1, 'Mon')’

      -- Metodo: __init_subclass__ (cls, **kwds)

          A 'classmethod' that is used to further configure subsequent
          subclasses.  By default, does nothing.

      -- Metodo: _missing_ (cls, value)

          A 'classmethod' for looking up values not found in 'cls'.  By
          default it does nothing, but can be overridden to implement
          custom search behavior:

               >>> from enum import auto, StrEnum
               >>> class Build(StrEnum):
               ...     DEBUG = auto()
               ...     OPTIMIZED = auto()
               ...     @classmethod
               ...     def _missing_(cls, value):
               ...         value = value.lower()
               ...         for member in cls:
               ...             if member.value == value:
               ...                 return member
               ...         return None
               ...
               >>> Build.DEBUG.value
               'debug'
               >>> Build('deBUG')
               <Build.DEBUG: 'debug'>

      -- Metodo: __new__ (cls, *args, **kwds)

          By default, doesn’t exist.  If specified, either in the enum
          class definition or in a mixin class (such as ‘int’), all
          values given in the member assignment will be passed; e.g.

               >>> from enum import Enum
               >>> class MyIntEnum(int, Enum):
               ...     TWENTYSIX = '1a', 16

          results in the call ‘int('1a', 16)’ and a value of ‘26’ for
          the member.

               Nota: When writing a custom ‘__new__’, do not use
               ‘super().__new__’ – call the appropriate ‘__new__’
               instead.

      -- Metodo: __repr__ (self)

          Returns the string used for 'repr()' calls.  By default,
          returns the 'Enum' name, member name, and value, but can be
          overridden:

               >>> from enum import auto, Enum
               >>> class OtherStyle(Enum):
               ...     ALTERNATE = auto()
               ...     OTHER = auto()
               ...     SOMETHING_ELSE = auto()
               ...     def __repr__(self):
               ...         cls_name = self.__class__.__name__
               ...         return f'{cls_name}.{self.name}'
               ...
               >>> OtherStyle.ALTERNATE, str(OtherStyle.ALTERNATE), f"{OtherStyle.ALTERNATE}"
               (OtherStyle.ALTERNATE, 'OtherStyle.ALTERNATE', 'OtherStyle.ALTERNATE')

      -- Metodo: __str__ (self)

          Returns the string used for 'str()' calls.  By default,
          returns the 'Enum' name and member name, but can be
          overridden:

               >>> from enum import auto, Enum
               >>> class OtherStyle(Enum):
               ...     ALTERNATE = auto()
               ...     OTHER = auto()
               ...     SOMETHING_ELSE = auto()
               ...     def __str__(self):
               ...         return f'{self.name}'
               ...
               >>> OtherStyle.ALTERNATE, str(OtherStyle.ALTERNATE), f"{OtherStyle.ALTERNATE}"
               (<OtherStyle.ALTERNATE: 1>, 'ALTERNATE', 'ALTERNATE')

      -- Metodo: __format__ (self)

          Returns the string used for 'format()' and 'f-string' calls.
          By default, returns *note __str__(): 835. return value, but
          can be overridden:

               >>> from enum import auto, Enum
               >>> class OtherStyle(Enum):
               ...     ALTERNATE = auto()
               ...     OTHER = auto()
               ...     SOMETHING_ELSE = auto()
               ...     def __format__(self, spec):
               ...         return f'{self.name}'
               ...
               >>> OtherStyle.ALTERNATE, str(OtherStyle.ALTERNATE), f"{OtherStyle.ALTERNATE}"
               (<OtherStyle.ALTERNATE: 1>, 'OtherStyle.ALTERNATE', 'ALTERNATE')

          Nota: Using *note auto: e9d. with *note Enum: 843. results in
          integers of increasing value, starting with ‘1’.

     Cambiato nella versione 3.12: Added *note Dataclass support: 1ae1.

      -- Metodo: _add_alias_ ()

          Adds a new name as an alias to an existing member:

               >>> Color.RED._add_alias_("ERROR")
               >>> Color.ERROR
               <Color.RED: 1>

          Raises a *note NameError: 452. if the name is already assigned
          to a different member.

          Added in version 3.13.

      -- Metodo: _add_value_alias_ ()

          Adds a new value as an alias to an existing member:

               >>> Color.RED._add_value_alias_(42)
               >>> Color(42)
               <Color.RED: 1>

          Raises a *note ValueError: 2ec. if the value is already linked
          with a different member.

          Added in version 3.13.

 -- Classe: enum.IntEnum

     'IntEnum' is the same as *note Enum: 843, but its members are also
     integers and can be used anywhere that an integer can be used.  If
     any integer operation is performed with an 'IntEnum' member, the
     resulting value loses its enumeration status.

          >>> from enum import IntEnum
          >>> class Number(IntEnum):
          ...     ONE = 1
          ...     TWO = 2
          ...     THREE = 3
          ...
          >>> Number.THREE
          <Number.THREE: 3>
          >>> Number.ONE + Number.TWO
          3
          >>> Number.THREE + 5
          8
          >>> Number.THREE == 3
          True

          Nota: Using *note auto: e9d. with *note IntEnum: edd. results
          in integers of increasing value, starting with ‘1’.

     Cambiato nella versione 3.11: *note __str__(): 831. is now
     ‘int.__str__()’ to better support the 'replacement of existing
     constants' use-case.  *note __format__(): 832. was already
     ‘int.__format__()’ for that same reason.

 -- Classe: enum.StrEnum

     'StrEnum' is the same as *note Enum: 843, but its members are also
     strings and can be used in most of the same places that a string
     can be used.  The result of any string operation performed on or
     with a 'StrEnum' member is not part of the enumeration.

          >>> from enum import StrEnum, auto
          >>> class Color(StrEnum):
          ...     RED = 'r'
          ...     GREEN = 'g'
          ...     BLUE = 'b'
          ...     UNKNOWN = auto()
          ...
          >>> Color.RED
          <Color.RED: 'r'>
          >>> Color.UNKNOWN
          <Color.UNKNOWN: 'unknown'>
          >>> str(Color.UNKNOWN)
          'unknown'

          Nota: There are places in the stdlib that check for an exact
          *note str: 169. instead of a *note str: 169. subclass (i.e.
          ‘type(unknown) == str’ instead of ‘isinstance(unknown, str)’),
          and in those locations you will need to use
          ‘str(MyStrEnum.MY_MEMBER)’.

          Nota: Using *note auto: e9d. with *note StrEnum: 82e. results
          in the lower-cased member name as the value.

          Nota: *note __str__(): 831. is ‘str.__str__()’ to better
          support the 'replacement of existing constants' use-case.
          *note __format__(): 832. is likewise ‘str.__format__()’ for
          that same reason.

     Added in version 3.11.

 -- Classe: enum.Flag

     ‘Flag’ is the same as *note Enum: 843, but its members support the
     bitwise operators ‘&’ ('AND'), ‘|’ ('OR'), ‘^’ ('XOR'), and ‘~’
     ('INVERT'); the results of those operations are (aliases of)
     members of the enumeration.

      -- Metodo: __contains__ (self, value)

          Returns 'True' if value is in self:

               >>> from enum import Flag, auto
               >>> class Color(Flag):
               ...     RED = auto()
               ...     GREEN = auto()
               ...     BLUE = auto()
               ...
               >>> purple = Color.RED | Color.BLUE
               >>> white = Color.RED | Color.GREEN | Color.BLUE
               >>> Color.GREEN in purple
               False
               >>> Color.GREEN in white
               True
               >>> purple in white
               True
               >>> white in purple
               False

      -- Metodo: __iter__(self):

          Returns all contained non-alias members:

               >>> list(Color.RED)
               [<Color.RED: 1>]
               >>> list(purple)
               [<Color.RED: 1>, <Color.BLUE: 4>]

          Added in version 3.11.

      -- Metodo: __len__(self):

          Returns number of members in flag:

               >>> len(Color.GREEN)
               1
               >>> len(white)
               3

          Added in version 3.11.

      -- Metodo: __bool__(self):

          Returns 'True' if any members in flag, 'False' otherwise:

               >>> bool(Color.GREEN)
               True
               >>> bool(white)
               True
               >>> black = Color(0)
               >>> bool(black)
               False

      -- Metodo: __or__ (self, other)

          Returns current flag binary or’ed with other:

               >>> Color.RED | Color.GREEN
               <Color.RED|GREEN: 3>

      -- Metodo: __and__ (self, other)

          Returns current flag binary and’ed with other:

               >>> purple & white
               <Color.RED|BLUE: 5>
               >>> purple & Color.GREEN
               <Color: 0>

      -- Metodo: __xor__ (self, other)

          Returns current flag binary xor’ed with other:

               >>> purple ^ white
               <Color.GREEN: 2>
               >>> purple ^ Color.GREEN
               <Color.RED|GREEN|BLUE: 7>

      -- Metodo: __invert__(self):

          Returns all the flags in 'type(self)' that are not in 'self':

               >>> ~white
               <Color: 0>
               >>> ~purple
               <Color.GREEN: 2>
               >>> ~Color.RED
               <Color.GREEN|BLUE: 6>

      -- Metodo: _numeric_repr_ ()

          Function used to format any remaining unnamed numeric values.
          Default is the value’s repr; common choices are *note hex():
          14d7. and *note oct(): 14d6.

          Nota: Using *note auto: e9d. with *note Flag: 836. results in
          integers that are powers of two, starting with ‘1’.

     Cambiato nella versione 3.11: The 'repr()' of zero-valued flags has
     changed.  It is now:

          >>> Color(0)
          <Color: 0>

 -- Classe: enum.IntFlag

     ‘IntFlag’ is the same as *note Flag: 836, but its members are also
     integers and can be used anywhere that an integer can be used.

          >>> from enum import IntFlag, auto
          >>> class Color(IntFlag):
          ...     RED = auto()
          ...     GREEN = auto()
          ...     BLUE = auto()
          ...
          >>> Color.RED & 2
          <Color: 0>
          >>> Color.RED | 2
          <Color.RED|GREEN: 3>

     If any integer operation is performed with an 'IntFlag' member, the
     result is not an 'IntFlag':

          >>> Color.RED + 2
          3

     If a *note Flag: 836. operation is performed with an 'IntFlag'
     member and:

        * the result is a valid 'IntFlag': an 'IntFlag' is returned

        * the result is not a valid 'IntFlag': the result depends on the
          *note FlagBoundary: 837. setting

     The *note repr(): 1c1. of unnamed zero-valued flags has changed.
     It is now:

          >>> Color(0)
          <Color: 0>

          Nota: Using *note auto: e9d. with *note IntFlag: e9c. results
          in integers that are powers of two, starting with ‘1’.

     Cambiato nella versione 3.11: *note __str__(): 831. is now
     ‘int.__str__()’ to better support the 'replacement of existing
     constants' use-case.  *note __format__(): 832. was already
     ‘int.__format__()’ for that same reason.

     Inversion of an ‘IntFlag’ now returns a positive value that is the
     union of all flags not in the given flag, rather than a negative
     value.  This matches the existing *note Flag: 836. behavior.

 -- Classe: enum.ReprEnum

     ‘ReprEnum’ uses the *note repr(): 1ae2. of *note Enum: 843, but the
     *note str(): 169. of the mixed-in data type:

        * ‘int.__str__()’ for *note IntEnum: edd. and *note IntFlag:
          e9c.

        * ‘str.__str__()’ for *note StrEnum: 82e.

     Inherit from ‘ReprEnum’ to keep the *note str(): 169. / *note
     format(): 199. of the mixed-in data type instead of using the *note
     Enum: 843.-default *note str(): 835.

     Added in version 3.11.

 -- Classe: enum.EnumCheck

     'EnumCheck' contains the options used by the *note verify(): 838.
     decorator to ensure various constraints; failed constraints result
     in a *note ValueError: 2ec.

      -- Attributo: UNIQUE

          Ensure that each value has only one name:

               >>> from enum import Enum, verify, UNIQUE
               >>> @verify(UNIQUE)
               ... class Color(Enum):
               ...     RED = 1
               ...     GREEN = 2
               ...     BLUE = 3
               ...     CRIMSON = 1
               Traceback (most recent call last):
               ...
               ValueError: aliases found in <enum 'Color'>: CRIMSON -> RED

      -- Attributo: CONTINUOUS

          Ensure that there are no missing values between the
          lowest-valued member and the highest-valued member:

               >>> from enum import Enum, verify, CONTINUOUS
               >>> @verify(CONTINUOUS)
               ... class Color(Enum):
               ...     RED = 1
               ...     GREEN = 2
               ...     BLUE = 5
               Traceback (most recent call last):
               ...
               ValueError: invalid enum 'Color': missing values 3, 4

      -- Attributo: NAMED_FLAGS

          Ensure that any flag groups/masks contain only named flags –
          useful when values are specified instead of being generated by
          *note auto(): e9d.:

               >>> from enum import Flag, verify, NAMED_FLAGS
               >>> @verify(NAMED_FLAGS)
               ... class Color(Flag):
               ...     RED = 1
               ...     GREEN = 2
               ...     BLUE = 4
               ...     WHITE = 15
               ...     NEON = 31
               Traceback (most recent call last):
               ...
               ValueError: invalid Flag 'Color': aliases WHITE and NEON are missing combined values of 0x18 [use enum.show_flag_values(value) for details]

          Nota: CONTINUOUS and NAMED_FLAGS are designed to work with
          integer-valued members.

     Added in version 3.11.

 -- Classe: enum.FlagBoundary

     ‘FlagBoundary’ controls how out-of-range values are handled in
     *note Flag: 836. and its subclasses.

      -- Attributo: STRICT

          Out-of-range values cause a *note ValueError: 2ec. to be
          raised.  This is the default for *note Flag: 836.:

               >>> from enum import Flag, STRICT, auto
               >>> class StrictFlag(Flag, boundary=STRICT):
               ...     RED = auto()
               ...     GREEN = auto()
               ...     BLUE = auto()
               ...
               >>> StrictFlag(2**2 + 2**4)
               Traceback (most recent call last):
               ...
               ValueError: <flag 'StrictFlag'> invalid value 20
                   given 0b0 10100
                 allowed 0b0 00111

      -- Attributo: CONFORM

          Out-of-range values have invalid values removed, leaving a
          valid *note Flag: 836. value:

               >>> from enum import Flag, CONFORM, auto
               >>> class ConformFlag(Flag, boundary=CONFORM):
               ...     RED = auto()
               ...     GREEN = auto()
               ...     BLUE = auto()
               ...
               >>> ConformFlag(2**2 + 2**4)
               <ConformFlag.BLUE: 4>

      -- Attributo: EJECT

          Out-of-range values lose their *note Flag: 836. membership and
          revert to *note int: 19b.

               >>> from enum import Flag, EJECT, auto
               >>> class EjectFlag(Flag, boundary=EJECT):
               ...     RED = auto()
               ...     GREEN = auto()
               ...     BLUE = auto()
               ...
               >>> EjectFlag(2**2 + 2**4)
               20

      -- Attributo: KEEP

          Out-of-range values are kept, and the *note Flag: 836.
          membership is kept.  This is the default for *note IntFlag:
          e9c.:

               >>> from enum import Flag, KEEP, auto
               >>> class KeepFlag(Flag, boundary=KEEP):
               ...     RED = auto()
               ...     GREEN = auto()
               ...     BLUE = auto()
               ...
               >>> KeepFlag(2**2 + 2**4)
               <KeepFlag.BLUE|16: 20>

     Added in version 3.11.

 -- Classe: enum.EnumDict

     'EnumDict' is a subclass of *note dict: 183. that is used as the
     namespace for defining enum classes (see *note Preparing the class
     namespace: e5a.).  It is exposed to allow subclasses of *note
     EnumType: 4f8. with advanced behavior like having multiple values
     per member.  It should be called with the name of the enum class
     being created, otherwise private names and internal classes will
     not be handled correctly.

     Note that only the *note MutableMapping: 12b4. interface (*note
     __setitem__(): 14d3. and *note update(): 166c.) is overridden.  It
     may be possible to bypass the checks using other ‘dict’ operations
     like *note |=: 23e4.

      -- Attributo: member_names

          A list of member names.

     Added in version 3.13.

__________________________________________________________________

* Menu:

* Supported __dunder__ names::
* Supported _sunder_ names::


File: python.info,  Node: Supported __dunder__ names,  Next: Supported _sunder_ names,  Up: Data Types<2>

5.8.14.3 Supported ‘__dunder__’ names
.....................................

*note __members__: 2a1a. is a read-only ordered mapping of
‘member_name’:‘member’ items.  It is only available on the class.

*note __new__(): 2a1e, if specified, must create and return the enum
members; it is also a very good idea to set the member’s ‘_value_’
appropriately.  Once all the members are created it is no longer used.


File: python.info,  Node: Supported _sunder_ names,  Prev: Supported __dunder__ names,  Up: Data Types<2>

5.8.14.4 Supported ‘_sunder_’ names
...................................

   - *note _name_: 2a1f. – name of the member

   - *note _value_: 2a20. – value of the member; can be set in ‘__new__’

   - *note _missing_(): 2a27. – a lookup function used when a value is
     not found; may be overridden

   - *note _ignore_: 2a22. – a list of names, either as a *note list:
     24d. or a *note str: 169, that will not be transformed into
     members, and will be removed from the final class

   - *note _order_: 2a21. – no longer used, kept for backward
     compatibility (class attribute, removed during class creation)

   - *note _generate_next_value_(): 2a24. – used to get an appropriate
     value for an enum member; may be overridden

          Nota: For standard *note Enum: 843. classes the next value
          chosen is the highest value seen incremented by one.

          For *note Flag: 836. classes the next value chosen will be the
          next highest power-of-two.

   - *note _add_alias_(): 2a28. – adds a new name as an alias to an
     existing member.

   - *note _add_value_alias_(): 2a29. – adds a new value as an alias to
     an existing member.

   - While ‘_sunder_’ names are generally reserved for the further
     development of the *note Enum: 843. class and can not be used, some
     are explicitly allowed:

        - ‘_repr_*’ (e.g.  ‘_repr_html_’), as used in IPython's rich
          display(1)

Added in version 3.6: ‘_missing_’, ‘_order_’, ‘_generate_next_value_’

Added in version 3.7: ‘_ignore_’

Added in version 3.13: ‘_add_alias_’, ‘_add_value_alias_’, ‘_repr_*’

__________________________________________________________________

   ---------- Footnotes ----------

   (1) 
https://ipython.readthedocs.io/en/stable/config/integrating.html#rich-display


File: python.info,  Node: Utilities and Decorators,  Next: Notes,  Prev: Data Types<2>,  Up: enum — Support for enumerations

5.8.14.5 Utilities and Decorators
.................................

 -- Classe: enum.auto

     'auto' can be used in place of a value.  If used, the 'Enum'
     machinery will call an *note Enum: 843.’s *note
     _generate_next_value_(): 2a24. to get an appropriate value.  For
     *note Enum: 843. and *note IntEnum: edd. that appropriate value
     will be the last value plus one; for *note Flag: 836. and *note
     IntFlag: e9c. it will be the first power-of-two greater than the
     highest value; for *note StrEnum: 82e. it will be the lower-cased
     version of the member’s name.  Care must be taken if mixing
     'auto()' with manually specified values.

     'auto' instances are only resolved when at the top level of an
     assignment, either by itself or as part of a tuple:

        * ‘FIRST = auto()’ will work (auto() is replaced with ‘1’);

        * ‘SECOND = auto(), -2’ will work (auto is replaced with ‘2’, so
          ‘2, -2’ is used to create the ‘SECOND’ enum member;

        * ‘THREE = [auto(), -3]’ will 'not' work (‘[<auto instance>,
          -3]’ is used to create the ‘THREE’ enum member)

     Cambiato nella versione 3.11.1: In prior versions, ‘auto()’ had to
     be the only thing on the assignment line to work properly.

     ‘_generate_next_value_’ can be overridden to customize the values
     used by 'auto'.

          Nota: in 3.13 the default ‘_generate_next_value_’ will always
          return the highest member value incremented by 1, and will
          fail if any member is an incompatible type.

 -- Funzione: @enum.property

     A decorator similar to the built-in 'property', but specifically
     for enumerations.  It allows member attributes to have the same
     names as members themselves.

          Nota: the 'property' and the member must be defined in
          separate classes; for example, the 'value' and 'name'
          attributes are defined in the 'Enum' class, and 'Enum'
          subclasses can define members with the names ‘value’ and
          ‘name’.

     Added in version 3.11.

 -- Funzione: @enum.unique

     A *note class: 14df. decorator specifically for enumerations.  It
     searches an enumeration’s *note __members__: 2a1a, gathering any
     aliases it finds; if any are found *note ValueError: 2ec. is raised
     with the details:

          >>> from enum import Enum, unique
          >>> @unique
          ... class Mistake(Enum):
          ...     ONE = 1
          ...     TWO = 2
          ...     THREE = 3
          ...     FOUR = 3
          ...
          Traceback (most recent call last):
          ...
          ValueError: duplicate values found in <enum 'Mistake'>: FOUR -> THREE

 -- Funzione: @enum.verify

     A *note class: 14df. decorator specifically for enumerations.
     Members from *note EnumCheck: 839. are used to specify which
     constraints should be checked on the decorated enumeration.

     Added in version 3.11.

 -- Funzione: @enum.member

     A decorator for use in enums: its target will become a member.

     Added in version 3.11.

 -- Funzione: @enum.nonmember

     A decorator for use in enums: its target will not become a member.

     Added in version 3.11.

 -- Funzione: @enum.global_enum

     A decorator to change the *note str(): 169. and *note repr(): 1c1.
     of an enum to show its members as belonging to the module instead
     of its class.  Should only be used when the enum members are
     exported to the module global namespace (see *note re.RegexFlag:
     840. for an example).

     Added in version 3.11.

 -- Funzione: enum.show_flag_values (value)

     Return a list of all power-of-two integers contained in a flag
     'value'.

     Added in version 3.11.

 -- Funzione: enum.bin (num, max_bits=None)

     Like built-in *note bin(): 14b0, except negative values are
     represented in two’s complement, and the leading bit always
     indicates sign (‘0’ implies positive, ‘1’ implies negative).

          >>> import enum
          >>> enum.bin(10)
          '0b0 1010'
          >>> enum.bin(~10)   # ~10 is -11
          '0b1 0101'

     Added in version 3.10.

__________________________________________________________________


File: python.info,  Node: Notes,  Prev: Utilities and Decorators,  Up: enum — Support for enumerations

5.8.14.6 Notes
..............

*note IntEnum: edd, *note StrEnum: 82e, and *note IntFlag: e9c.

     These three enum types are designed to be drop-in replacements for
     existing integer- and string-based values; as such, they have extra
     limitations:

        - ‘__str__’ uses the value and not the name of the enum member

        - ‘__format__’, because it uses ‘__str__’, will also use the
          value of the enum member instead of its name

     If you do not need/want those limitations, you can either create
     your own base class by mixing in the ‘int’ or ‘str’ type yourself:

          >>> from enum import Enum
          >>> class MyIntEnum(int, Enum):
          ...     pass

     or you can reassign the appropriate *note str(): 169, etc., in your
     enum:

          >>> from enum import Enum, IntEnum
          >>> class MyIntEnum(IntEnum):
          ...     __str__ = Enum.__str__


File: python.info,  Node: graphlib — Functionality to operate with graph-like structures,  Prev: enum — Support for enumerations,  Up: Data Types

5.8.15 ‘graphlib’ — Functionality to operate with graph-like structures
-----------------------------------------------------------------------

'Source code:' Lib/graphlib.py(1)

__________________________________________________________________

 -- Classe: graphlib.TopologicalSorter (graph=None)

     Provides functionality to topologically sort a graph of *note
     hashable: 825. nodes.

     A topological order is a linear ordering of the vertices in a graph
     such that for every directed edge u -> v from vertex u to vertex v,
     vertex u comes before vertex v in the ordering.  For instance, the
     vertices of the graph may represent tasks to be performed, and the
     edges may represent constraints that one task must be performed
     before another; in this example, a topological ordering is just a
     valid sequence for the tasks.  A complete topological ordering is
     possible if and only if the graph has no directed cycles, that is,
     if it is a directed acyclic graph.

     If the optional 'graph' argument is provided it must be a
     dictionary representing a directed acyclic graph where the keys are
     nodes and the values are iterables of all predecessors of that node
     in the graph (the nodes that have edges that point to the value in
     the key).  Additional nodes can be added to the graph using the
     *note add(): 2a3e. method.

     In the general case, the steps required to perform the sorting of a
     given graph are as follows:

        * Create an instance of the *note TopologicalSorter: ae0. with
          an optional initial graph.

        * Add additional nodes to the graph.

        * Call *note prepare(): 21f. on the graph.

        * While *note is_active(): 2a3f. is ‘True’, iterate over the
          nodes returned by *note get_ready(): 2a40. and process them.
          Call *note done(): 2a41. on each node as it finishes
          processing.

     In case just an immediate sorting of the nodes in the graph is
     required and no parallelism is involved, the convenience method
     *note TopologicalSorter.static_order(): 2a42. can be used directly:

          >>> graph = {"D": {"B", "C"}, "C": {"A"}, "B": {"A"}}
          >>> ts = TopologicalSorter(graph)
          >>> tuple(ts.static_order())
          ('A', 'C', 'B', 'D')

     The class is designed to easily support parallel processing of the
     nodes as they become ready.  For instance:

          topological_sorter = TopologicalSorter()

          # Add nodes to 'topological_sorter'...

          topological_sorter.prepare()
          while topological_sorter.is_active():
              for node in topological_sorter.get_ready():
                  # Worker threads or processes take nodes to work on off the
                  # 'task_queue' queue.
                  task_queue.put(node)

              # When the work for a node is done, workers put the node in
              # 'finalized_tasks_queue' so we can get more nodes to work on.
              # The definition of 'is_active()' guarantees that, at this point, at
              # least one node has been placed on 'task_queue' that hasn't yet
              # been passed to 'done()', so this blocking 'get()' must (eventually)
              # succeed.  After calling 'done()', we loop back to call 'get_ready()'
              # again, so put newly freed nodes on 'task_queue' as soon as
              # logically possible.
              node = finalized_tasks_queue.get()
              topological_sorter.done(node)

      -- Metodo: add (node, *predecessors)

          Add a new node and its predecessors to the graph.  Both the
          'node' and all elements in 'predecessors' must be *note
          hashable: 825.

          If called multiple times with the same node argument, the set
          of dependencies will be the union of all dependencies passed
          in.

          It is possible to add a node with no dependencies
          ('predecessors' is not provided) or to provide a dependency
          twice.  If a node that has not been provided before is
          included among 'predecessors' it will be automatically added
          to the graph with no predecessors of its own.

          Raises *note ValueError: 2ec. if called after *note prepare():
          21f.

      -- Metodo: prepare ()

          Mark the graph as finished and check for cycles in the graph.
          If any cycle is detected, *note CycleError: 2a43. will be
          raised, but *note get_ready(): 2a40. can still be used to
          obtain as many nodes as possible until cycles block more
          progress.  After a call to this function, the graph cannot be
          modified, and therefore no more nodes can be added using *note
          add(): 2a3e.

          A *note ValueError: 2ec. will be raised if the sort has been
          started by *note static_order(): 2a42. or *note get_ready():
          2a40.

          Cambiato nella versione 3.14: ‘prepare()’ can now be called
          more than once as long as the sort has not started.
          Previously this raised *note ValueError: 2ec.

      -- Metodo: is_active ()

          Returns ‘True’ if more progress can be made and ‘False’
          otherwise.  Progress can be made if cycles do not block the
          resolution and either there are still nodes ready that haven’t
          yet been returned by *note TopologicalSorter.get_ready():
          2a40. or the number of nodes marked *note
          TopologicalSorter.done(): 2a41. is less than the number that
          have been returned by *note TopologicalSorter.get_ready():
          2a40.

          The *note __bool__(): 14dd. method of this class defers to
          this function, so instead of:

               if ts.is_active():
                   ...

          it is possible to simply do:

               if ts:
                   ...

          Raises *note ValueError: 2ec. if called without calling *note
          prepare(): 21f. previously.

      -- Metodo: done (*nodes)

          Marks a set of nodes returned by *note
          TopologicalSorter.get_ready(): 2a40. as processed, unblocking
          any successor of each node in 'nodes' for being returned in
          the future by a call to *note TopologicalSorter.get_ready():
          2a40.

          Raises *note ValueError: 2ec. if any node in 'nodes' has
          already been marked as processed by a previous call to this
          method or if a node was not added to the graph by using *note
          TopologicalSorter.add(): 2a3e, if called without calling *note
          prepare(): 21f. or if node has not yet been returned by *note
          get_ready(): 2a40.

      -- Metodo: get_ready ()

          Returns a ‘tuple’ with all the nodes that are ready.
          Initially it returns all nodes with no predecessors, and once
          those are marked as processed by calling *note
          TopologicalSorter.done(): 2a41, further calls will return all
          new nodes that have all their predecessors already processed.
          Once no more progress can be made, empty tuples are returned.

          Raises *note ValueError: 2ec. if called without calling *note
          prepare(): 21f. previously.

      -- Metodo: static_order ()

          Returns an iterator object which will iterate over nodes in a
          topological order.  When using this method, *note prepare():
          21f. and *note done(): 2a41. should not be called.  This
          method is equivalent to:

               def static_order(self):
                   self.prepare()
                   while self.is_active():
                       node_group = self.get_ready()
                       yield from node_group
                       self.done(*node_group)

          The particular order that is returned may depend on the
          specific order in which the items were inserted in the graph.
          For example:

               >>> ts = TopologicalSorter()
               >>> ts.add(3, 2, 1)
               >>> ts.add(1, 0)
               >>> print([*ts.static_order()])
               [2, 0, 1, 3]

               >>> ts2 = TopologicalSorter()
               >>> ts2.add(1, 0)
               >>> ts2.add(3, 2, 1)
               >>> print([*ts2.static_order()])
               [0, 2, 1, 3]

          This is due to the fact that «0» and «2» are in the same level
          in the graph (they would have been returned in the same call
          to *note get_ready(): 2a40.) and the order between them is
          determined by the order of insertion.

          If any cycle is detected, *note CycleError: 2a43. will be
          raised.

     Added in version 3.9.

* Menu:

* Exceptions: Exceptions<3>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/graphlib.py


File: python.info,  Node: Exceptions<3>,  Up: graphlib — Functionality to operate with graph-like structures

5.8.15.1 Exceptions
...................

The *note graphlib: 69. module defines the following exception classes:

 -- Eccezione: graphlib.CycleError

     Subclass of *note ValueError: 2ec. raised by *note
     TopologicalSorter.prepare(): 21f. if cycles exist in the working
     graph.  If multiple cycles exist, only one undefined choice among
     them will be reported and included in the exception.

     The detected cycle can be accessed via the second element in the
     *note args: 78e. attribute of the exception instance and consists
     in a list of nodes, such that each node is, in the graph, an
     immediate predecessor of the next node in the list.  In the
     reported list, the first and the last node will be the same, to
     make it clear that it is cyclic.


File: python.info,  Node: Numeric and Mathematical Modules,  Next: Functional Programming Modules,  Prev: Data Types,  Up: The Python Standard Library

5.9 Numeric and Mathematical Modules
====================================

The modules described in this chapter provide numeric and math-related
functions and data types.  The *note numbers: a2. module defines an
abstract hierarchy of numeric types.  The *note math: 92. and *note
cmath: 19. modules contain various mathematical functions for
floating-point and complex numbers.  The *note decimal: 3a. module
supports exact representations of decimal numbers, using arbitrary
precision arithmetic.

The following modules are documented in this chapter:

* Menu:

* numbers — Numeric abstract base classes::
* math — Mathematical functions::
* cmath — Mathematical functions for complex numbers::
* decimal — Decimal fixed-point and floating-point arithmetic::
* fractions — Rational numbers::
* random — Generate pseudo-random numbers::
* statistics — Mathematical statistics functions::


File: python.info,  Node: numbers — Numeric abstract base classes,  Next: math — Mathematical functions,  Up: Numeric and Mathematical Modules

5.9.1 ‘numbers’ — Numeric abstract base classes
-----------------------------------------------

'Source code:' Lib/numbers.py(1)

__________________________________________________________________

The ‘numbers’ module ( PEP 3141(2)) defines a hierarchy of numeric *note
abstract base classes: 13be. which progressively define more operations.
None of the types defined in this module are intended to be
instantiated.

 -- Classe: numbers.Number

     The root of the numeric hierarchy.  If you just want to check if an
     argument 'x' is a number, without caring what kind, use
     ‘isinstance(x, Number)’.

* Menu:

* The numeric tower::
* Notes for type implementers::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/numbers.py

   (2) https://peps.python.org/pep-3141/


File: python.info,  Node: The numeric tower,  Next: Notes for type implementers,  Up: numbers — Numeric abstract base classes

5.9.1.1 The numeric tower
.........................

 -- Classe: numbers.Complex

     Subclasses of this type describe complex numbers and include the
     operations that work on the built-in *note complex: 197. type.
     These are: conversions to *note complex: 197. and *note bool: 3c3,
     *note real: 2a4d, *note imag: 2a4e, ‘+’, ‘-’, ‘*’, ‘/’, ‘**’, *note
     abs(): 2077, *note conjugate(): 2a4f, ‘==’, and ‘!=’.  All except
     ‘-’ and ‘!=’ are abstract.

      -- Attributo: real

          Abstract.  Retrieves the real component of this number.

      -- Attributo: imag

          Abstract.  Retrieves the imaginary component of this number.

      -- Metodo: abstractmethod conjugate ()

          Abstract.  Returns the complex conjugate.  For example,
          ‘(1+3j).conjugate() == (1-3j)’.

 -- Classe: numbers.Real

     To *note Complex: 25db, ‘Real’ adds the operations that work on
     real numbers.

     In short, those are: a conversion to *note float: 196, *note
     math.trunc(): 15c7, *note round(): 14e2, *note math.floor(): 15c5,
     *note math.ceil(): 15c6, *note divmod(): b9b, ‘//’, ‘%’, ‘<’, ‘<=’,
     ‘>’, and ‘>=’.

     Real also provides defaults for *note complex(): 197, *note real:
     2a4d, *note imag: 2a4e, and *note conjugate(): 2a4f.

 -- Classe: numbers.Rational

     Subtypes *note Real: 25d1. and adds *note numerator: 2a50. and
     *note denominator: 2a51. properties.  It also provides a default
     for *note float(): 196.

     The *note numerator: 2a50. and *note denominator: 2a51. values
     should be instances of *note Integral: 23ed. and should be in
     lowest terms with *note denominator: 2a51. positive.

      -- Attributo: numerator

          Abstract.  The numerator of this rational number.

      -- Attributo: denominator

          Abstract.  The denominator of this rational number.

 -- Classe: numbers.Integral

     Subtypes *note Rational: 14c6. and adds a conversion to *note int:
     19b.  Provides defaults for *note float(): 196, *note numerator:
     2a50, and *note denominator: 2a51.  Adds abstract methods for *note
     pow(): 1a4. with modulus and bit-string operations: ‘<<’, ‘>>’,
     ‘&’, ‘^’, ‘|’, ‘~’.


File: python.info,  Node: Notes for type implementers,  Prev: The numeric tower,  Up: numbers — Numeric abstract base classes

5.9.1.2 Notes for type implementers
...................................

Implementers should be careful to make equal numbers equal and hash them
to the same values.  This may be subtle if there are two different
extensions of the real numbers.  For example, *note fractions.Fraction:
213. implements *note hash(): 802. as follows:

     def __hash__(self):
         if self.denominator == 1:
             # Get integers right.
             return hash(self.numerator)
         # Expensive check, but definitely correct.
         if self == float(self):
             return hash(float(self))
         else:
             # Use tuple's hash to avoid a high collision rate on
             # simple fractions.
             return hash((self.numerator, self.denominator))

* Menu:

* Adding More Numeric ABCs::
* Implementing the arithmetic operations::


File: python.info,  Node: Adding More Numeric ABCs,  Next: Implementing the arithmetic operations,  Up: Notes for type implementers

5.9.1.3 Adding More Numeric ABCs
................................

There are, of course, more possible ABCs for numbers, and this would be
a poor hierarchy if it precluded the possibility of adding those.  You
can add ‘MyFoo’ between *note Complex: 25db. and *note Real: 25d1. with:

     class MyFoo(Complex): ...
     MyFoo.register(Real)


File: python.info,  Node: Implementing the arithmetic operations,  Prev: Adding More Numeric ABCs,  Up: Notes for type implementers

5.9.1.4 Implementing the arithmetic operations
..............................................

We want to implement the arithmetic operations so that mixed-mode
operations either call an implementation whose author knew about the
types of both arguments, or convert both to the nearest built in type
and do the operation there.  For subtypes of *note Integral: 23ed, this
means that *note __add__(): 23c3. and *note __radd__(): 23c4. should be
defined as:

     class MyIntegral(Integral):

         def __add__(self, other):
             if isinstance(other, MyIntegral):
                 return do_my_adding_stuff(self, other)
             elif isinstance(other, OtherTypeIKnowAbout):
                 return do_my_other_adding_stuff(self, other)
             else:
                 return NotImplemented

         def __radd__(self, other):
             if isinstance(other, MyIntegral):
                 return do_my_adding_stuff(other, self)
             elif isinstance(other, OtherTypeIKnowAbout):
                 return do_my_other_adding_stuff(other, self)
             elif isinstance(other, Integral):
                 return int(other) + int(self)
             elif isinstance(other, Real):
                 return float(other) + float(self)
             elif isinstance(other, Complex):
                 return complex(other) + complex(self)
             else:
                 return NotImplemented

There are 5 different cases for a mixed-type operation on subclasses of
*note Complex: 25db.  I’ll refer to all of the above code that doesn’t
refer to ‘MyIntegral’ and ‘OtherTypeIKnowAbout’ as «boilerplate».  ‘a’
will be an instance of ‘A’, which is a subtype of *note Complex: 25db.
(‘a : A <: Complex’), and ‘b : B <: Complex’.  I’ll consider ‘a + b’:

  1. If ‘A’ defines an *note __add__(): 23c3. which accepts ‘b’, all is
     well.

  2. If ‘A’ falls back to the boilerplate code, and it were to return a
     value from *note __add__(): 23c3, we’d miss the possibility that
     ‘B’ defines a more intelligent *note __radd__(): 23c4, so the
     boilerplate should return *note NotImplemented: 1a2. from
     ‘__add__()’.  (Or ‘A’ may not implement ‘__add__()’ at all.)

  3. Then ‘B’’s *note __radd__(): 23c4. gets a chance.  If it accepts
     ‘a’, all is well.

  4. If it falls back to the boilerplate, there are no more possible
     methods to try, so this is where the default implementation should
     live.

  5. If ‘B <: A’, Python tries ‘B.__radd__’ before ‘A.__add__’.  This is
     ok, because it was implemented with knowledge of ‘A’, so it can
     handle those instances before delegating to *note Complex: 25db.

If ‘A <: Complex’ and ‘B <: Real’ without sharing any other knowledge,
then the appropriate shared operation is the one involving the built in
*note complex: 197, and both *note __radd__(): 23c4. s land there, so
‘a+b == b+a’.

Because most of the operations on any given type will be very similar,
it can be useful to define a helper function which generates the forward
and reverse instances of any given operator.  For example, *note
fractions.Fraction: 213. uses:

     def _operator_fallbacks(monomorphic_operator, fallback_operator):
         def forward(a, b):
             if isinstance(b, (int, Fraction)):
                 return monomorphic_operator(a, b)
             elif isinstance(b, float):
                 return fallback_operator(float(a), b)
             elif isinstance(b, complex):
                 return fallback_operator(complex(a), b)
             else:
                 return NotImplemented
         forward.__name__ = '__' + fallback_operator.__name__ + '__'
         forward.__doc__ = monomorphic_operator.__doc__

         def reverse(b, a):
             if isinstance(a, Rational):
                 # Includes ints.
                 return monomorphic_operator(a, b)
             elif isinstance(a, Real):
                 return fallback_operator(float(a), float(b))
             elif isinstance(a, Complex):
                 return fallback_operator(complex(a), complex(b))
             else:
                 return NotImplemented
         reverse.__name__ = '__r' + fallback_operator.__name__ + '__'
         reverse.__doc__ = monomorphic_operator.__doc__

         return forward, reverse

     def _add(a, b):
         """a + b"""
         return Fraction(a.numerator * b.denominator +
                         b.numerator * a.denominator,
                         a.denominator * b.denominator)

     __add__, __radd__ = _operator_fallbacks(_add, operator.add)

     # ...


File: python.info,  Node: math — Mathematical functions,  Next: cmath — Mathematical functions for complex numbers,  Prev: numbers — Numeric abstract base classes,  Up: Numeric and Mathematical Modules

5.9.2 ‘math’ — Mathematical functions
-------------------------------------

__________________________________________________________________

This module provides access to common mathematical functions and
constants, including those defined by the C standard.

These functions cannot be used with complex numbers; use the functions
of the same name from the *note cmath: 19. module if you require support
for complex numbers.  The distinction between functions which support
complex numbers and those which don’t is made since most users do not
want to learn quite as much mathematics as required to understand
complex numbers.  Receiving an exception instead of a complex result
allows earlier detection of the unexpected complex number used as a
parameter, so that the programmer can determine how and why it was
generated in the first place.

The following functions are provided by this module.  Except when
explicitly noted otherwise, all return values are floats.

'Number-theoretic functions'

*note comb(n, k): 8e0.                                   Number of ways to choose 'k' items from 'n' items without repetition and without order
                                                         
                                                         
*note factorial(n): b43.                                 'n' factorial
                                                         
                                                         
*note gcd(*integers): b0e.                               Greatest common divisor of the integer arguments
                                                         
                                                         
*note isqrt(n): bfa.                                     Integer square root of a nonnegative integer 'n'
                                                         
                                                         
*note lcm(*integers): b0f.                               Least common multiple of the integer arguments
                                                         
                                                         
*note perm(n, k): 8e1.                                   Number of ways to choose 'k' items from 'n' items without repetition and with order
                                                         
                                                         
'Floating point arithmetic'

*note ceil(x): 15c6.                                     Ceiling of 'x', the smallest integer greater than or equal to 'x'
                                                         
                                                         
*note fabs(x): 2a58.                                     Absolute value of 'x'
                                                         
                                                         
*note floor(x): 15c5.                                    Floor of 'x', the largest integer less than or equal to 'x'
                                                         
                                                         
*note fma(x, y, z): 515.                                 Fused multiply-add operation: ‘(x * y) + z’
                                                         
                                                         
*note fmod(x, y): 24a4.                                  Remainder of division ‘x / y’
                                                         
                                                         
*note modf(x): 2a59.                                     Fractional and integer parts of 'x'
                                                         
                                                         
*note remainder(x, y): d4c.                              Remainder of 'x' with respect to 'y'
                                                         
                                                         
*note trunc(x): 15c7.                                    Integer part of 'x'
                                                         
                                                         
'Floating point manipulation functions'

*note copysign(x, y): 15da.                              Magnitude (absolute value) of 'x' with the sign of 'y'
                                                         
                                                         
*note frexp(x): 2a5a.                                    Mantissa and exponent of 'x'
                                                         
                                                         
*note isclose(a, b, rel_tol, abs_tol): fb2.              Check if the values 'a' and 'b' are close to each other
                                                         
                                                         
*note isfinite(x): 13f3.                                 Check if 'x' is neither an infinity nor a NaN
                                                         
                                                         
*note isinf(x): 15d8.                                    Check if 'x' is a positive or negative infinity
                                                         
                                                         
*note isnan(x): 15d9.                                    Check if 'x' is a NaN (not a number)
                                                         
                                                         
*note ldexp(x, i): 1828.                                 ‘x * (2**i)’, inverse of function *note frexp(): 2a5a.
                                                         
                                                         
*note nextafter(x, y, steps): 6c1.                       Floating-point value 'steps' steps after 'x' towards 'y'
                                                         
                                                         
*note ulp(x): b10.                                       Value of the least significant bit of 'x'
                                                         
                                                         
'Power, exponential and logarithmic functions'

*note cbrt(x): 872.                                      Cube root of 'x'
                                                         
                                                         
*note exp(x): 151b.                                      'e' raised to the power 'x'
                                                         
                                                         
*note exp2(x): 871.                                      '2' raised to the power 'x'
                                                         
                                                         
*note expm1(x): 13f4.                                    'e' raised to the power 'x', minus 1
                                                         
                                                         
*note log(x, base): 16c7.                                Logarithm of 'x' to the given base ('e' by default)
                                                         
                                                         
*note log1p(x): 15df.                                    Natural logarithm of '1+x' (base 'e')
                                                         
                                                         
*note log2(x): 12e3.                                     Base-2 logarithm of 'x'
                                                         
                                                         
*note log10(x): 1930.                                    Base-10 logarithm of 'x'
                                                         
                                                         
*note pow(x, y): 873.                                    'x' raised to the power 'y'
                                                         
                                                         
*note sqrt(x): bfb.                                      Square root of 'x'
                                                         
                                                         
'Summation and product functions'

*note dist(p, q): bf7.                                   Euclidean distance between two points 'p' and 'q' given as an iterable of coordinates
                                                         
                                                         
*note fsum(iterable): 15db.                              Sum of values in the input 'iterable'
                                                         
                                                         
*note hypot(*coordinates): bf8.                          Euclidean norm of an iterable of coordinates
                                                         
                                                         
*note prod(iterable, start): bf9.                        Product of elements in the input 'iterable' with a 'start' value
                                                         
                                                         
*note sumprod(p, q): 6c0.                                Sum of products from two iterables 'p' and 'q'
                                                         
                                                         
'Angular conversion'

*note degrees(x): 2a5b.                                  Convert angle 'x' from radians to degrees
                                                         
                                                         
*note radians(x): 2a5c.                                  Convert angle 'x' from degrees to radians
                                                         
                                                         
'Trigonometric functions'

*note acos(x): 2a5d.                                     Arc cosine of 'x'
                                                         
                                                         
*note asin(x): 2a5e.                                     Arc sine of 'x'
                                                         
                                                         
*note atan(x): 2a5f.                                     Arc tangent of 'x'
                                                         
                                                         
*note atan2(y, x): 2a60.                                 ‘atan(y / x)’
                                                         
                                                         
*note cos(x): 16c6.                                      Cosine of 'x'
                                                         
                                                         
*note sin(x): 16c5.                                      Sine of 'x'
                                                         
                                                         
*note tan(x): 2a61.                                      Tangent of 'x'
                                                         
                                                         
'Hyperbolic functions'

*note acosh(x): 15dc.                                    Inverse hyperbolic cosine of 'x'
                                                         
                                                         
*note asinh(x): 15dd.                                    Inverse hyperbolic sine of 'x'
                                                         
                                                         
*note atanh(x): 15de.                                    Inverse hyperbolic tangent of 'x'
                                                         
                                                         
*note cosh(x): 2a62.                                     Hyperbolic cosine of 'x'
                                                         
                                                         
*note sinh(x): 2a63.                                     Hyperbolic sine of 'x'
                                                         
                                                         
*note tanh(x): 2a64.                                     Hyperbolic tangent of 'x'
                                                         
                                                         
'Special functions'

*note erf(x): dd5.                                       Error function(1) at 'x'
                                                         
                                                         
*note erfc(x): dd6.                                      Complementary error function(2) at 'x'
                                                         
                                                         
*note gamma(x): 13f5.                                    Gamma function(3) at 'x'
                                                         
                                                         
*note lgamma(x): 13f6.                                   Natural logarithm of the absolute value of the Gamma function(4) at 'x'
                                                         
                                                         
'Constants'

*note pi: 2a65.                                          'π' = 3.141592…
                                                         
                                                         
*note e: 2a66.                                           'e' = 2.718281…
                                                         
                                                         
*note tau: 2a67.                                         'τ' = 2'π' = 6.283185…
                                                         
                                                         
*note inf: e82.                                          Positive infinity
                                                         
                                                         
*note nan: 874.                                          «Not a number» (NaN)
                                                         

* Menu:

* Number-theoretic functions::
* Floating point arithmetic::
* Floating point manipulation functions::
* Power, exponential and logarithmic functions: Power exponential and logarithmic functions.
* Summation and product functions::
* Angular conversion::
* Trigonometric functions::
* Hyperbolic functions::
* Special functions::
* Constants: Constants<2>.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Error_function

   (2) https://en.wikipedia.org/wiki/Error_function

   (3) https://en.wikipedia.org/wiki/Gamma_function

   (4) https://en.wikipedia.org/wiki/Gamma_function


File: python.info,  Node: Number-theoretic functions,  Next: Floating point arithmetic,  Up: math — Mathematical functions

5.9.2.1 Number-theoretic functions
..................................

 -- Funzione: math.comb (n, k)

     Return the number of ways to choose 'k' items from 'n' items
     without repetition and without order.

     Evaluates to ‘n! / (k! * (n - k)!)’ when ‘k <= n’ and evaluates to
     zero when ‘k > n’.

     Also called the binomial coefficient because it is equivalent to
     the coefficient of k-th term in polynomial expansion of ‘(1 + x)ⁿ’.

     Raises *note TypeError: 198. if either of the arguments are not
     integers.  Raises *note ValueError: 2ec. if either of the arguments
     are negative.

     Added in version 3.8.

 -- Funzione: math.factorial (n)

     Return factorial of the nonnegative integer 'n'.

     Cambiato nella versione 3.10: Floats with integral values (like
     ‘5.0’) are no longer accepted.

 -- Funzione: math.gcd (*integers)

     Return the greatest common divisor of the specified integer
     arguments.  If any of the arguments is nonzero, then the returned
     value is the largest positive integer that is a divisor of all
     arguments.  If all arguments are zero, then the returned value is
     ‘0’.  ‘gcd()’ without arguments returns ‘0’.

     Added in version 3.5.

     Cambiato nella versione 3.9: Added support for an arbitrary number
     of arguments.  Formerly, only two arguments were supported.

 -- Funzione: math.isqrt (n)

     Return the integer square root of the nonnegative integer 'n'.
     This is the floor of the exact square root of 'n', or equivalently
     the greatest integer 'a' such that 'a'² ≤ 'n'.

     For some applications, it may be more convenient to have the least
     integer 'a' such that 'n' ≤ 'a'², or in other words the ceiling of
     the exact square root of 'n'.  For positive 'n', this can be
     computed using ‘a = 1 + isqrt(n - 1)’.

     Added in version 3.8.

 -- Funzione: math.lcm (*integers)

     Return the least common multiple of the specified integer
     arguments.  If all arguments are nonzero, then the returned value
     is the smallest positive integer that is a multiple of all
     arguments.  If any of the arguments is zero, then the returned
     value is ‘0’.  ‘lcm()’ without arguments returns ‘1’.

     Added in version 3.9.

 -- Funzione: math.perm (n, k=None)

     Return the number of ways to choose 'k' items from 'n' items
     without repetition and with order.

     Evaluates to ‘n! / (n - k)!’ when ‘k <= n’ and evaluates to zero
     when ‘k > n’.

     If 'k' is not specified or is ‘None’, then 'k' defaults to 'n' and
     the function returns ‘n!’.

     Raises *note TypeError: 198. if either of the arguments are not
     integers.  Raises *note ValueError: 2ec. if either of the arguments
     are negative.

     Added in version 3.8.


File: python.info,  Node: Floating point arithmetic,  Next: Floating point manipulation functions,  Prev: Number-theoretic functions,  Up: math — Mathematical functions

5.9.2.2 Floating point arithmetic
.................................

 -- Funzione: math.ceil (x)

     Return the ceiling of 'x', the smallest integer greater than or
     equal to 'x'.  If 'x' is not a float, delegates to *note
     x.__ceil__: 23ec, which should return an *note Integral: 23ed.
     value.

 -- Funzione: math.fabs (x)

     Return the absolute value of 'x'.

 -- Funzione: math.floor (x)

     Return the floor of 'x', the largest integer less than or equal to
     'x'.  If 'x' is not a float, delegates to *note x.__floor__: 23eb,
     which should return an *note Integral: 23ed. value.

 -- Funzione: math.fma (x, y, z)

     Fused multiply-add operation.  Return ‘(x * y) + z’, computed as
     though with infinite precision and range followed by a single round
     to the ‘float’ format.  This operation often provides better
     accuracy than the direct expression ‘(x * y) + z’.

     This function follows the specification of the fusedMultiplyAdd
     operation described in the IEEE 754 standard.  The standard leaves
     one case implementation-defined, namely the result of ‘fma(0, inf,
     nan)’ and ‘fma(inf, 0, nan)’.  In these cases, ‘math.fma’ returns a
     NaN, and does not raise any exception.

     Added in version 3.13.

 -- Funzione: math.fmod (x, y)

     Return the floating-point remainder of ‘x / y’, as defined by the
     platform C library function ‘fmod(x, y)’.  Note that the Python
     expression ‘x % y’ may not return the same result.  The intent of
     the C standard is that ‘fmod(x, y)’ be exactly (mathematically; to
     infinite precision) equal to ‘x - n*y’ for some integer 'n' such
     that the result has the same sign as 'x' and magnitude less than
     ‘abs(y)’.  Python’s ‘x % y’ returns a result with the sign of 'y'
     instead, and may not be exactly computable for float arguments.
     For example, ‘fmod(-1e-100, 1e100)’ is ‘-1e-100’, but the result of
     Python’s ‘-1e-100 % 1e100’ is ‘1e100-1e-100’, which cannot be
     represented exactly as a float, and rounds to the surprising
     ‘1e100’.  For this reason, function *note fmod(): 24a4. is
     generally preferred when working with floats, while Python’s ‘x %
     y’ is preferred when working with integers.

 -- Funzione: math.modf (x)

     Return the fractional and integer parts of 'x'.  Both results carry
     the sign of 'x' and are floats.

     Note that *note modf(): 2a59. has a different call/return pattern
     than its C equivalents: it takes a single argument and return a
     pair of values, rather than returning its second return value
     through an “output parameter” (there is no such thing in Python).

 -- Funzione: math.remainder (x, y)

     Return the IEEE 754-style remainder of 'x' with respect to 'y'.
     For finite 'x' and finite nonzero 'y', this is the difference ‘x -
     n*y’, where ‘n’ is the closest integer to the exact value of the
     quotient ‘x / y’.  If ‘x / y’ is exactly halfway between two
     consecutive integers, the nearest 'even' integer is used for ‘n’.
     The remainder ‘r = remainder(x, y)’ thus always satisfies ‘abs(r)
     <= 0.5 * abs(y)’.

     Special cases follow IEEE 754: in particular, ‘remainder(x,
     math.inf)’ is 'x' for any finite 'x', and ‘remainder(x, 0)’ and
     ‘remainder(math.inf, x)’ raise *note ValueError: 2ec. for any
     non-NaN 'x'.  If the result of the remainder operation is zero,
     that zero will have the same sign as 'x'.

     On platforms using IEEE 754 binary floating point, the result of
     this operation is always exactly representable: no rounding error
     is introduced.

     Added in version 3.7.

 -- Funzione: math.trunc (x)

     Return 'x' with the fractional part removed, leaving the integer
     part.  This rounds toward 0: ‘trunc()’ is equivalent to *note
     floor(): 15c5. for positive 'x', and equivalent to *note ceil():
     15c6. for negative 'x'.  If 'x' is not a float, delegates to *note
     x.__trunc__: 19c, which should return an *note Integral: 23ed.
     value.

For the *note ceil(): 15c6, *note floor(): 15c5, and *note modf(): 2a59.
functions, note that 'all' floating-point numbers of sufficiently large
magnitude are exact integers.  Python floats typically carry no more
than 53 bits of precision (the same as the platform C double type), in
which case any float 'x' with ‘abs(x) >= 2**52’ necessarily has no
fractional bits.


File: python.info,  Node: Floating point manipulation functions,  Next: Power exponential and logarithmic functions,  Prev: Floating point arithmetic,  Up: math — Mathematical functions

5.9.2.3 Floating point manipulation functions
.............................................

 -- Funzione: math.copysign (x, y)

     Return a float with the magnitude (absolute value) of 'x' but the
     sign of 'y'.  On platforms that support signed zeros,
     ‘copysign(1.0, -0.0)’ returns '-1.0'.

 -- Funzione: math.frexp (x)

     Return the mantissa and exponent of 'x' as the pair ‘(m, e)’.  'm'
     is a float and 'e' is an integer such that ‘x == m * 2**e’ exactly.
     If 'x' is zero, returns ‘(0.0, 0)’, otherwise ‘0.5 <= abs(m) < 1’.
     This is used to «pick apart» the internal representation of a float
     in a portable way.

     Note that *note frexp(): 2a5a. has a different call/return pattern
     than its C equivalents: it takes a single argument and return a
     pair of values, rather than returning its second return value
     through an “output parameter” (there is no such thing in Python).

 -- Funzione: math.isclose (a, b, *, rel_tol=1e-09, abs_tol=0.0)

     Return ‘True’ if the values 'a' and 'b' are close to each other and
     ‘False’ otherwise.

     Whether or not two values are considered close is determined
     according to given absolute and relative tolerances.  If no errors
     occur, the result will be: ‘abs(a-b) <= max(rel_tol * max(abs(a),
     abs(b)), abs_tol)’.

     'rel_tol' is the relative tolerance – it is the maximum allowed
     difference between 'a' and 'b', relative to the larger absolute
     value of 'a' or 'b'.  For example, to set a tolerance of 5%, pass
     ‘rel_tol=0.05’.  The default tolerance is ‘1e-09’, which assures
     that the two values are the same within about 9 decimal digits.
     'rel_tol' must be nonnegative and less than ‘1.0’.

     'abs_tol' is the absolute tolerance; it defaults to ‘0.0’ and it
     must be nonnegative.  When comparing ‘x’ to ‘0.0’, ‘isclose(x, 0)’
     is computed as ‘abs(x) <= rel_tol * abs(x)’, which is ‘False’ for
     any nonzero ‘x’ and 'rel_tol' less than ‘1.0’.  So add an
     appropriate positive 'abs_tol' argument to the call.

     The IEEE 754 special values of ‘NaN’, ‘inf’, and ‘-inf’ will be
     handled according to IEEE rules.  Specifically, ‘NaN’ is not
     considered close to any other value, including ‘NaN’.  ‘inf’ and
     ‘-inf’ are only considered close to themselves.

     Added in version 3.5.

     Vedi anche
     ..........

     PEP 485(1) – A function for testing approximate equality

 -- Funzione: math.isfinite (x)

     Return ‘True’ if 'x' is neither an infinity nor a NaN, and ‘False’
     otherwise.  (Note that ‘0.0’ 'is' considered finite.)

     Added in version 3.2.

 -- Funzione: math.isinf (x)

     Return ‘True’ if 'x' is a positive or negative infinity, and
     ‘False’ otherwise.

 -- Funzione: math.isnan (x)

     Return ‘True’ if 'x' is a NaN (not a number), and ‘False’
     otherwise.

 -- Funzione: math.ldexp (x, i)

     Return ‘x * (2**i)’.  This is essentially the inverse of function
     *note frexp(): 2a5a.

 -- Funzione: math.nextafter (x, y, steps=1)

     Return the floating-point value 'steps' steps after 'x' towards
     'y'.

     If 'x' is equal to 'y', return 'y', unless 'steps' is zero.

     Examples:

        * ‘math.nextafter(x, math.inf)’ goes up: towards positive
          infinity.

        * ‘math.nextafter(x, -math.inf)’ goes down: towards minus
          infinity.

        * ‘math.nextafter(x, 0.0)’ goes towards zero.

        * ‘math.nextafter(x, math.copysign(math.inf, x))’ goes away from
          zero.

     See also *note math.ulp(): b10.

     Added in version 3.9.

     Cambiato nella versione 3.12: Added the 'steps' argument.

 -- Funzione: math.ulp (x)

     Return the value of the least significant bit of the float 'x':

        * If 'x' is a NaN (not a number), return 'x'.

        * If 'x' is negative, return ‘ulp(-x)’.

        * If 'x' is a positive infinity, return 'x'.

        * If 'x' is equal to zero, return the smallest positive
          'denormalized' representable float (smaller than the minimum
          positive 'normalized' float, *note sys.float_info.min: 1db7.).

        * If 'x' is equal to the largest positive representable float,
          return the value of the least significant bit of 'x', such
          that the first float smaller than 'x' is ‘x - ulp(x)’.

        * Otherwise ('x' is a positive finite number), return the value
          of the least significant bit of 'x', such that the first float
          bigger than 'x' is ‘x + ulp(x)’.

     ULP stands for «Unit in the Last Place».

     See also *note math.nextafter(): 6c1. and *note
     sys.float_info.epsilon: 1db7.

     Added in version 3.9.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0485/


File: python.info,  Node: Power exponential and logarithmic functions,  Next: Summation and product functions,  Prev: Floating point manipulation functions,  Up: math — Mathematical functions

5.9.2.4 Power, exponential and logarithmic functions
....................................................

 -- Funzione: math.cbrt (x)

     Return the cube root of 'x'.

     Added in version 3.11.

 -- Funzione: math.exp (x)

     Return 'e' raised to the power 'x', where 'e' = 2.718281… is the
     base of natural logarithms.  This is usually more accurate than
     ‘math.e ** x’ or ‘pow(math.e, x)’.

 -- Funzione: math.exp2 (x)

     Return '2' raised to the power 'x'.

     Added in version 3.11.

 -- Funzione: math.expm1 (x)

     Return 'e' raised to the power 'x', minus 1.  Here 'e' is the base
     of natural logarithms.  For small floats 'x', the subtraction in
     ‘exp(x) - 1’ can result in a significant loss of precision(1); the
     *note expm1(): 13f4. function provides a way to compute this
     quantity to full precision:

          >>> from math import exp, expm1
          >>> exp(1e-5) - 1  # gives result accurate to 11 places
          1.0000050000069649e-05
          >>> expm1(1e-5)    # result accurate to full precision
          1.0000050000166668e-05

     Added in version 3.2.

 -- Funzione: math.log (x[, base])

     With one argument, return the natural logarithm of 'x' (to base
     'e').

     With two arguments, return the logarithm of 'x' to the given
     'base', calculated as ‘log(x)/log(base)’.

 -- Funzione: math.log1p (x)

     Return the natural logarithm of '1+x' (base 'e').  The result is
     calculated in a way which is accurate for 'x' near zero.

 -- Funzione: math.log2 (x)

     Return the base-2 logarithm of 'x'.  This is usually more accurate
     than ‘log(x, 2)’.

     Added in version 3.3.

     Vedi anche
     ..........

     *note int.bit_length(): 25d5. returns the number of bits necessary
     to represent an integer in binary, excluding the sign and leading
     zeros.

 -- Funzione: math.log10 (x)

     Return the base-10 logarithm of 'x'.  This is usually more accurate
     than ‘log(x, 10)’.

 -- Funzione: math.pow (x, y)

     Return 'x' raised to the power 'y'.  Exceptional cases follow the
     IEEE 754 standard as far as possible.  In particular, ‘pow(1.0, x)’
     and ‘pow(x, 0.0)’ always return ‘1.0’, even when 'x' is a zero or a
     NaN. If both 'x' and 'y' are finite, 'x' is negative, and 'y' is
     not an integer then ‘pow(x, y)’ is undefined, and raises *note
     ValueError: 2ec.

     Unlike the built-in ‘**’ operator, *note math.pow(): 873. converts
     both its arguments to type *note float: 196.  Use ‘**’ or the
     built-in *note pow(): 1a4. function for computing exact integer
     powers.

     Cambiato nella versione 3.11: The special cases ‘pow(0.0, -inf)’
     and ‘pow(-0.0, -inf)’ were changed to return ‘inf’ instead of
     raising *note ValueError: 2ec, for consistency with IEEE 754.

 -- Funzione: math.sqrt (x)

     Return the square root of 'x'.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Loss_of_significance


File: python.info,  Node: Summation and product functions,  Next: Angular conversion,  Prev: Power exponential and logarithmic functions,  Up: math — Mathematical functions

5.9.2.5 Summation and product functions
.......................................

 -- Funzione: math.dist (p, q)

     Return the Euclidean distance between two points 'p' and 'q', each
     given as a sequence (or iterable) of coordinates.  The two points
     must have the same dimension.

     Roughly equivalent to:

          sqrt(sum((px - qx) ** 2.0 for px, qx in zip(p, q)))

     Added in version 3.8.

 -- Funzione: math.fsum (iterable)

     Return an accurate floating-point sum of values in the iterable.
     Avoids loss of precision by tracking multiple intermediate partial
     sums.

     The algorithm’s accuracy depends on IEEE-754 arithmetic guarantees
     and the typical case where the rounding mode is half-even.  On some
     non-Windows builds, the underlying C library uses extended
     precision addition and may occasionally double-round an
     intermediate sum causing it to be off in its least significant bit.

     For further discussion and two alternative approaches, see the ASPN
     cookbook recipes for accurate floating-point summation(1).

 -- Funzione: math.hypot (*coordinates)

     Return the Euclidean norm, ‘sqrt(sum(x**2 for x in coordinates))’.
     This is the length of the vector from the origin to the point given
     by the coordinates.

     For a two dimensional point ‘(x, y)’, this is equivalent to
     computing the hypotenuse of a right triangle using the Pythagorean
     theorem, ‘sqrt(x*x + y*y)’.

     Cambiato nella versione 3.8: Added support for n-dimensional
     points.  Formerly, only the two dimensional case was supported.

     Cambiato nella versione 3.10: Improved the algorithm’s accuracy so
     that the maximum error is under 1 ulp (unit in the last place).
     More typically, the result is almost always correctly rounded to
     within 1/2 ulp.

 -- Funzione: math.prod (iterable, *, start=1)

     Calculate the product of all the elements in the input 'iterable'.
     The default 'start' value for the product is ‘1’.

     When the iterable is empty, return the start value.  This function
     is intended specifically for use with numeric values and may reject
     non-numeric types.

     Added in version 3.8.

 -- Funzione: math.sumprod (p, q)

     Return the sum of products of values from two iterables 'p' and
     'q'.

     Raises *note ValueError: 2ec. if the inputs do not have the same
     length.

     Roughly equivalent to:

          sum(map(operator.mul, p, q, strict=True))

     For float and mixed int/float inputs, the intermediate products and
     sums are computed with extended precision.

     Added in version 3.12.

   ---------- Footnotes ----------

   (1) 
https://code.activestate.com/recipes/393090-binary-floating-point-summation-accurate-to-full-p/


File: python.info,  Node: Angular conversion,  Next: Trigonometric functions,  Prev: Summation and product functions,  Up: math — Mathematical functions

5.9.2.6 Angular conversion
..........................

 -- Funzione: math.degrees (x)

     Convert angle 'x' from radians to degrees.

 -- Funzione: math.radians (x)

     Convert angle 'x' from degrees to radians.


File: python.info,  Node: Trigonometric functions,  Next: Hyperbolic functions,  Prev: Angular conversion,  Up: math — Mathematical functions

5.9.2.7 Trigonometric functions
...............................

 -- Funzione: math.acos (x)

     Return the arc cosine of 'x', in radians.  The result is between
     ‘0’ and ‘pi’.

 -- Funzione: math.asin (x)

     Return the arc sine of 'x', in radians.  The result is between
     ‘-pi/2’ and ‘pi/2’.

 -- Funzione: math.atan (x)

     Return the arc tangent of 'x', in radians.  The result is between
     ‘-pi/2’ and ‘pi/2’.

 -- Funzione: math.atan2 (y, x)

     Return ‘atan(y / x)’, in radians.  The result is between ‘-pi’ and
     ‘pi’.  The vector in the plane from the origin to point ‘(x, y)’
     makes this angle with the positive X axis.  The point of *note
     atan2(): 2a60. is that the signs of both inputs are known to it, so
     it can compute the correct quadrant for the angle.  For example,
     ‘atan(1)’ and ‘atan2(1, 1)’ are both ‘pi/4’, but ‘atan2(-1, -1)’ is
     ‘-3*pi/4’.

 -- Funzione: math.cos (x)

     Return the cosine of 'x' radians.

 -- Funzione: math.sin (x)

     Return the sine of 'x' radians.

 -- Funzione: math.tan (x)

     Return the tangent of 'x' radians.


File: python.info,  Node: Hyperbolic functions,  Next: Special functions,  Prev: Trigonometric functions,  Up: math — Mathematical functions

5.9.2.8 Hyperbolic functions
............................

Hyperbolic functions(1) are analogs of trigonometric functions that are
based on hyperbolas instead of circles.

 -- Funzione: math.acosh (x)

     Return the inverse hyperbolic cosine of 'x'.

 -- Funzione: math.asinh (x)

     Return the inverse hyperbolic sine of 'x'.

 -- Funzione: math.atanh (x)

     Return the inverse hyperbolic tangent of 'x'.

 -- Funzione: math.cosh (x)

     Return the hyperbolic cosine of 'x'.

 -- Funzione: math.sinh (x)

     Return the hyperbolic sine of 'x'.

 -- Funzione: math.tanh (x)

     Return the hyperbolic tangent of 'x'.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Hyperbolic_functions


File: python.info,  Node: Special functions,  Next: Constants<2>,  Prev: Hyperbolic functions,  Up: math — Mathematical functions

5.9.2.9 Special functions
.........................

 -- Funzione: math.erf (x)

     Return the error function(1) at 'x'.

     The *note erf(): dd5. function can be used to compute traditional
     statistical functions such as the cumulative standard normal
     distribution(2):

          def phi(x):
              'Cumulative distribution function for the standard normal distribution'
              return (1.0 + erf(x / sqrt(2.0))) / 2.0

     Added in version 3.2.

 -- Funzione: math.erfc (x)

     Return the complementary error function at 'x'.  The complementary
     error function(3) is defined as ‘1.0 - erf(x)’.  It is used for
     large values of 'x' where a subtraction from one would cause a loss
     of significance(4).

     Added in version 3.2.

 -- Funzione: math.gamma (x)

     Return the Gamma function(5) at 'x'.

     Added in version 3.2.

 -- Funzione: math.lgamma (x)

     Return the natural logarithm of the absolute value of the Gamma
     function at 'x'.

     Added in version 3.2.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Error_function

   (2) https://en.wikipedia.org/wiki/Cumulative_distribution_function

   (3) https://en.wikipedia.org/wiki/Error_function

   (4) https://en.wikipedia.org/wiki/Loss_of_significance

   (5) https://en.wikipedia.org/wiki/Gamma_function


File: python.info,  Node: Constants<2>,  Prev: Special functions,  Up: math — Mathematical functions

5.9.2.10 Constants
..................

 -- Dati: math.pi

     The mathematical constant 'π' = 3.141592…, to available precision.

 -- Dati: math.e

     The mathematical constant 'e' = 2.718281…, to available precision.

 -- Dati: math.tau

     The mathematical constant 'τ' = 6.283185…, to available precision.
     Tau is a circle constant equal to 2'π', the ratio of a circle’s
     circumference to its radius.  To learn more about Tau, check out Vi
     Hart’s video Pi is (still) Wrong(1), and start celebrating Tau
     day(2) by eating twice as much pie!

     Added in version 3.6.

 -- Dati: math.inf

     A floating-point positive infinity.  (For negative infinity, use
     ‘-math.inf’.)  Equivalent to the output of ‘float('inf')’.

     Added in version 3.5.

 -- Dati: math.nan

     A floating-point «not a number» (NaN) value.  Equivalent to the
     output of ‘float('nan')’.  Due to the requirements of the IEEE-754
     standard(3), ‘math.nan’ and ‘float('nan')’ are not considered to
     equal to any other numeric value, including themselves.  To check
     whether a number is a NaN, use the *note isnan(): 15d9. function to
     test for NaNs instead of ‘is’ or ‘==’.  Example:

          >>> import math
          >>> math.nan == math.nan
          False
          >>> float('nan') == float('nan')
          False
          >>> math.isnan(math.nan)
          True
          >>> math.isnan(float('nan'))
          True

     Added in version 3.5.

     Cambiato nella versione 3.11: It is now always available.

'Dettaglio dell’implementazione di CPython:' The *note math: 92. module
consists mostly of thin wrappers around the platform C math library
functions.  Behavior in exceptional cases follows Annex F of the C99
standard where appropriate.  The current implementation will raise *note
ValueError: 2ec. for invalid operations like ‘sqrt(-1.0)’ or ‘log(0.0)’
(where C99 Annex F recommends signaling invalid operation or
divide-by-zero), and *note OverflowError: a83. for results that overflow
(for example, ‘exp(1000.0)’).  A NaN will not be returned from any of
the functions above unless one or more of the input arguments was a NaN;
in that case, most functions will return a NaN, but (again following C99
Annex F) there are some exceptions to this rule, for example
‘pow(float('nan'), 0.0)’ or ‘hypot(float('nan'), float('inf'))’.

Note that Python makes no effort to distinguish signaling NaNs from
quiet NaNs, and behavior for signaling NaNs remains unspecified.
Typical behavior is to treat all NaNs as though they were quiet.

Vedi anche
..........

Module *note cmath: 19.

     Complex number versions of many of these functions.

   ---------- Footnotes ----------

   (1) https://vimeo.com/147792667

   (2) https://tauday.com/

   (3) https://en.wikipedia.org/wiki/IEEE_754


File: python.info,  Node: cmath — Mathematical functions for complex numbers,  Next: decimal — Decimal fixed-point and floating-point arithmetic,  Prev: math — Mathematical functions,  Up: Numeric and Mathematical Modules

5.9.3 ‘cmath’ — Mathematical functions for complex numbers
----------------------------------------------------------

__________________________________________________________________

This module provides access to mathematical functions for complex
numbers.  The functions in this module accept integers, floating-point
numbers or complex numbers as arguments.  They will also accept any
Python object that has either a *note __complex__(): 7fe. or a *note
__float__(): bc3. method: these methods are used to convert the object
to a complex or floating-point number, respectively, and the function is
then applied to the result of the conversion.

     Nota: For functions involving branch cuts, we have the problem of
     deciding how to define those functions on the cut itself.
     Following Kahan’s «Branch cuts for complex elementary functions»
     paper, as well as Annex G of C99 and later C standards, we use the
     sign of zero to distinguish one side of the branch cut from the
     other: for a branch cut along (a portion of) the real axis we look
     at the sign of the imaginary part, while for a branch cut along the
     imaginary axis we look at the sign of the real part.

     For example, the *note cmath.sqrt(): 2a75. function has a branch
     cut along the negative real axis.  An argument of ‘-2-0j’ is
     treated as though it lies 'below' the branch cut, and so gives a
     result on the negative imaginary axis:

          >>> cmath.sqrt(-2-0j)
          -1.4142135623730951j

     But an argument of ‘-2+0j’ is treated as though it lies above the
     branch cut:

          >>> cmath.sqrt(-2+0j)
          1.4142135623730951j

'Conversions to and from polar coordinates'

*note phase(z): 2a76.                                    Return the phase of 'z'
                                                         
                                                         
*note polar(z): 2a77.                                    Return the representation of 'z' in polar coordinates
                                                         
                                                         
*note rect(r, phi): 2a78.                                Return the complex number 'z' with polar coordinates 'r' and 'phi'
                                                         
                                                         
'Power and logarithmic functions'

*note exp(z): 2a79.                                      Return 'e' raised to the power 'z'
                                                         
                                                         
*note log(z[, base]): 2a7a.                              Return the logarithm of 'z' to the given 'base' ('e' by default)
                                                         
                                                         
*note log10(z): 2a7b.                                    Return the base-10 logarithm of 'z'
                                                         
                                                         
*note sqrt(z): 2a75.                                     Return the square root of 'z'
                                                         
                                                         
'Trigonometric functions'

*note acos(z): 2a7c.                                     Return the arc cosine of 'z'
                                                         
                                                         
*note asin(z): 2a7d.                                     Return the arc sine of 'z'
                                                         
                                                         
*note atan(z): 2a7e.                                     Return the arc tangent of 'z'
                                                         
                                                         
*note cos(z): 2a7f.                                      Return the cosine of 'z'
                                                         
                                                         
*note sin(z): 2a80.                                      Return the sine of 'z'
                                                         
                                                         
*note tan(z): 2a81.                                      Return the tangent of 'z'
                                                         
                                                         
'Hyperbolic functions'

*note acosh(z): 2a82.                                    Return the inverse hyperbolic cosine of 'z'
                                                         
                                                         
*note asinh(z): 2a83.                                    Return the inverse hyperbolic sine of 'z'
                                                         
                                                         
*note atanh(z): 2a84.                                    Return the inverse hyperbolic tangent of 'z'
                                                         
                                                         
*note cosh(z): 2a85.                                     Return the hyperbolic cosine of 'z'
                                                         
                                                         
*note sinh(z): 2a86.                                     Return the hyperbolic sine of 'z'
                                                         
                                                         
*note tanh(z): 2a87.                                     Return the hyperbolic tangent of 'z'
                                                         
                                                         
'Classification functions'

*note isfinite(z): 2a88.                                 Check if all components of 'z' are finite
                                                         
                                                         
*note isinf(z): 2a89.                                    Check if any component of 'z' is infinite
                                                         
                                                         
*note isnan(z): 2a8a.                                    Check if any component of 'z' is a NaN
                                                         
                                                         
*note isclose(a, b, *, rel_tol, abs_tol): fb3.           Check if the values 'a' and 'b' are close to each other
                                                         
                                                         
'Constants'

*note pi: 2a8b.                                          'π' = 3.141592…
                                                         
                                                         
*note e: 2a8c.                                           'e' = 2.718281…
                                                         
                                                         
*note tau: e7f.                                          'τ' = 2'π' = 6.283185…
                                                         
                                                         
*note inf: e80.                                          Positive infinity
                                                         
                                                         
*note infj: e83.                                         Pure imaginary infinity
                                                         
                                                         
*note nan: e81.                                          «Not a number» (NaN)
                                                         
                                                         
*note nanj: e84.                                         Pure imaginary NaN
                                                         

* Menu:

* Conversions to and from polar coordinates::
* Power and logarithmic functions::
* Trigonometric functions: Trigonometric functions<2>.
* Hyperbolic functions: Hyperbolic functions<2>.
* Classification functions::
* Constants: Constants<3>.


File: python.info,  Node: Conversions to and from polar coordinates,  Next: Power and logarithmic functions,  Up: cmath — Mathematical functions for complex numbers

5.9.3.1 Conversions to and from polar coordinates
.................................................

A Python complex number ‘z’ is stored internally using 'rectangular' or
'Cartesian' coordinates.  It is completely determined by its 'real part'
‘z.real’ and its 'imaginary part' ‘z.imag’.

'Polar coordinates' give an alternative way to represent a complex
number.  In polar coordinates, a complex number 'z' is defined by the
modulus 'r' and the phase angle 'phi'.  The modulus 'r' is the distance
from 'z' to the origin, while the phase 'phi' is the counterclockwise
angle, measured in radians, from the positive x-axis to the line segment
that joins the origin to 'z'.

The following functions can be used to convert from the native
rectangular coordinates to polar coordinates and back.

 -- Funzione: cmath.phase (z)

     Return the phase of 'z' (also known as the 'argument' of 'z'), as a
     float.  ‘phase(z)’ is equivalent to ‘math.atan2(z.imag, z.real)’.
     The result lies in the range [-'π', 'π'], and the branch cut for
     this operation lies along the negative real axis.  The sign of the
     result is the same as the sign of ‘z.imag’, even when ‘z.imag’ is
     zero:

          >>> phase(-1+0j)
          3.141592653589793
          >>> phase(-1-0j)
          -3.141592653589793

     Nota: The modulus (absolute value) of a complex number 'z' can be
     computed using the built-in *note abs(): 2077. function.  There is
     no separate *note cmath: 19. module function for this operation.

 -- Funzione: cmath.polar (z)

     Return the representation of 'z' in polar coordinates.  Returns a
     pair ‘(r, phi)’ where 'r' is the modulus of 'z' and 'phi' is the
     phase of 'z'.  ‘polar(z)’ is equivalent to ‘(abs(z), phase(z))’.

 -- Funzione: cmath.rect (r, phi)

     Return the complex number 'z' with polar coordinates 'r' and 'phi'.
     Equivalent to ‘complex(r * math.cos(phi), r * math.sin(phi))’.


File: python.info,  Node: Power and logarithmic functions,  Next: Trigonometric functions<2>,  Prev: Conversions to and from polar coordinates,  Up: cmath — Mathematical functions for complex numbers

5.9.3.2 Power and logarithmic functions
.......................................

 -- Funzione: cmath.exp (z)

     Return 'e' raised to the power 'z', where 'e' is the base of
     natural logarithms.

 -- Funzione: cmath.log (z[, base])

     Return the logarithm of 'z' to the given 'base'.  If the 'base' is
     not specified, returns the natural logarithm of 'z'.  There is one
     branch cut, from 0 along the negative real axis to -∞.

 -- Funzione: cmath.log10 (z)

     Return the base-10 logarithm of 'z'.  This has the same branch cut
     as *note log(): 2a7a.

 -- Funzione: cmath.sqrt (z)

     Return the square root of 'z'.  This has the same branch cut as
     *note log(): 2a7a.


File: python.info,  Node: Trigonometric functions<2>,  Next: Hyperbolic functions<2>,  Prev: Power and logarithmic functions,  Up: cmath — Mathematical functions for complex numbers

5.9.3.3 Trigonometric functions
...............................

 -- Funzione: cmath.acos (z)

     Return the arc cosine of 'z'.  There are two branch cuts: One
     extends right from 1 along the real axis to ∞.  The other extends
     left from -1 along the real axis to -∞.

 -- Funzione: cmath.asin (z)

     Return the arc sine of 'z'.  This has the same branch cuts as *note
     acos(): 2a7c.

 -- Funzione: cmath.atan (z)

     Return the arc tangent of 'z'.  There are two branch cuts: One
     extends from ‘1j’ along the imaginary axis to ‘∞j’.  The other
     extends from ‘-1j’ along the imaginary axis to ‘-∞j’.

 -- Funzione: cmath.cos (z)

     Return the cosine of 'z'.

 -- Funzione: cmath.sin (z)

     Return the sine of 'z'.

 -- Funzione: cmath.tan (z)

     Return the tangent of 'z'.


File: python.info,  Node: Hyperbolic functions<2>,  Next: Classification functions,  Prev: Trigonometric functions<2>,  Up: cmath — Mathematical functions for complex numbers

5.9.3.4 Hyperbolic functions
............................

 -- Funzione: cmath.acosh (z)

     Return the inverse hyperbolic cosine of 'z'.  There is one branch
     cut, extending left from 1 along the real axis to -∞.

 -- Funzione: cmath.asinh (z)

     Return the inverse hyperbolic sine of 'z'.  There are two branch
     cuts: One extends from ‘1j’ along the imaginary axis to ‘∞j’.  The
     other extends from ‘-1j’ along the imaginary axis to ‘-∞j’.

 -- Funzione: cmath.atanh (z)

     Return the inverse hyperbolic tangent of 'z'.  There are two branch
     cuts: One extends from ‘1’ along the real axis to ‘∞’.  The other
     extends from ‘-1’ along the real axis to ‘-∞’.

 -- Funzione: cmath.cosh (z)

     Return the hyperbolic cosine of 'z'.

 -- Funzione: cmath.sinh (z)

     Return the hyperbolic sine of 'z'.

 -- Funzione: cmath.tanh (z)

     Return the hyperbolic tangent of 'z'.


File: python.info,  Node: Classification functions,  Next: Constants<3>,  Prev: Hyperbolic functions<2>,  Up: cmath — Mathematical functions for complex numbers

5.9.3.5 Classification functions
................................

 -- Funzione: cmath.isfinite (z)

     Return ‘True’ if both the real and imaginary parts of 'z' are
     finite, and ‘False’ otherwise.

     Added in version 3.2.

 -- Funzione: cmath.isinf (z)

     Return ‘True’ if either the real or the imaginary part of 'z' is an
     infinity, and ‘False’ otherwise.

 -- Funzione: cmath.isnan (z)

     Return ‘True’ if either the real or the imaginary part of 'z' is a
     NaN, and ‘False’ otherwise.

 -- Funzione: cmath.isclose (a, b, *, rel_tol=1e-09, abs_tol=0.0)

     Return ‘True’ if the values 'a' and 'b' are close to each other and
     ‘False’ otherwise.

     Whether or not two values are considered close is determined
     according to given absolute and relative tolerances.  If no errors
     occur, the result will be: ‘abs(a-b) <= max(rel_tol * max(abs(a),
     abs(b)), abs_tol)’.

     'rel_tol' is the relative tolerance – it is the maximum allowed
     difference between 'a' and 'b', relative to the larger absolute
     value of 'a' or 'b'.  For example, to set a tolerance of 5%, pass
     ‘rel_tol=0.05’.  The default tolerance is ‘1e-09’, which assures
     that the two values are the same within about 9 decimal digits.
     'rel_tol' must be nonnegative and less than ‘1.0’.

     'abs_tol' is the absolute tolerance; it defaults to ‘0.0’ and it
     must be nonnegative.  When comparing ‘x’ to ‘0.0’, ‘isclose(x, 0)’
     is computed as ‘abs(x) <= rel_tol * abs(x)’, which is ‘False’ for
     any ‘x’ and rel_tol less than ‘1.0’.  So add an appropriate
     positive abs_tol argument to the call.

     The IEEE 754 special values of ‘NaN’, ‘inf’, and ‘-inf’ will be
     handled according to IEEE rules.  Specifically, ‘NaN’ is not
     considered close to any other value, including ‘NaN’.  ‘inf’ and
     ‘-inf’ are only considered close to themselves.

     Added in version 3.5.

     Vedi anche
     ..........

     PEP 485(1) – A function for testing approximate equality

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0485/


File: python.info,  Node: Constants<3>,  Prev: Classification functions,  Up: cmath — Mathematical functions for complex numbers

5.9.3.6 Constants
.................

 -- Dati: cmath.pi

     The mathematical constant 'π', as a float.

 -- Dati: cmath.e

     The mathematical constant 'e', as a float.

 -- Dati: cmath.tau

     The mathematical constant 'τ', as a float.

     Added in version 3.6.

 -- Dati: cmath.inf

     Floating-point positive infinity.  Equivalent to ‘float('inf')’.

     Added in version 3.6.

 -- Dati: cmath.infj

     Complex number with zero real part and positive infinity imaginary
     part.  Equivalent to ‘complex(0.0, float('inf'))’.

     Added in version 3.6.

 -- Dati: cmath.nan

     A floating-point «not a number» (NaN) value.  Equivalent to
     ‘float('nan')’.  See also *note math.nan: 874.

     Added in version 3.6.

 -- Dati: cmath.nanj

     Complex number with zero real part and NaN imaginary part.
     Equivalent to ‘complex(0.0, float('nan'))’.

     Added in version 3.6.

Note that the selection of functions is similar, but not identical, to
that in module *note math: 92.  The reason for having two modules is
that some users aren’t interested in complex numbers, and perhaps don’t
even know what they are.  They would rather have ‘math.sqrt(-1)’ raise
an exception than return a complex number.  Also note that the functions
defined in *note cmath: 19. always return a complex number, even if the
answer can be expressed as a real number (in which case the complex
number has an imaginary part of zero).

A note on branch cuts: They are curves along which the given function
fails to be continuous.  They are a necessary feature of many complex
functions.  It is assumed that if you need to compute with complex
functions, you will understand about branch cuts.  Consult almost any
(not too elementary) book on complex variables for enlightenment.  For
information of the proper choice of branch cuts for numerical purposes,
a good reference should be the following:

Vedi anche
..........

Kahan, W: Branch cuts for complex elementary functions; or, Much ado
about nothing’s sign bit.  In Iserles, A., and Powell, M. (eds.), The
state of the art in numerical analysis.  Clarendon Press (1987)
pp165–211.


File: python.info,  Node: decimal — Decimal fixed-point and floating-point arithmetic,  Next: fractions — Rational numbers,  Prev: cmath — Mathematical functions for complex numbers,  Up: Numeric and Mathematical Modules

5.9.4 ‘decimal’ — Decimal fixed-point and floating-point arithmetic
-------------------------------------------------------------------

'Source code:' Lib/decimal.py(1)

__________________________________________________________________

The *note decimal: 3a. module provides support for fast correctly
rounded decimal floating-point arithmetic.  It offers several advantages
over the *note float: 196. datatype:

   * Decimal «is based on a floating-point model(2) which was designed
     with people in mind, and necessarily has a paramount guiding
     principle – computers must provide an arithmetic that works in the
     same way as the arithmetic that people learn at school.» – excerpt
     from the decimal arithmetic specification.

   * Decimal numbers can be represented exactly.  In contrast, numbers
     like ‘1.1’ and ‘2.2’ do not have exact representations in binary
     floating point.  End users typically would not expect ‘1.1 + 2.2’
     to display as ‘3.3000000000000003’ as it does with binary floating
     point.

   * The exactness carries over into arithmetic.  In decimal floating
     point, ‘0.1 + 0.1 + 0.1 - 0.3’ is exactly equal to zero.  In binary
     floating point, the result is ‘5.5511151231257827e-017’.  While
     near to zero, the differences prevent reliable equality testing and
     differences can accumulate.  For this reason, decimal is preferred
     in accounting applications which have strict equality invariants.

   * The decimal module incorporates a notion of significant places so
     that ‘1.30 + 1.20’ is ‘2.50’.  The trailing zero is kept to
     indicate significance.  This is the customary presentation for
     monetary applications.  For multiplication, the «schoolbook»
     approach uses all the figures in the multiplicands.  For instance,
     ‘1.3 * 1.2’ gives ‘1.56’ while ‘1.30 * 1.20’ gives ‘1.5600’.

   * Unlike hardware based binary floating point, the decimal module has
     a user alterable precision (defaulting to 28 places) which can be
     as large as needed for a given problem:

          >>> from decimal import *
          >>> getcontext().prec = 6
          >>> Decimal(1) / Decimal(7)
          Decimal('0.142857')
          >>> getcontext().prec = 28
          >>> Decimal(1) / Decimal(7)
          Decimal('0.1428571428571428571428571429')

   * Both binary and decimal floating point are implemented in terms of
     published standards.  While the built-in float type exposes only a
     modest portion of its capabilities, the decimal module exposes all
     required parts of the standard.  When needed, the programmer has
     full control over rounding and signal handling.  This includes an
     option to enforce exact arithmetic by using exceptions to block any
     inexact operations.

   * The decimal module was designed to support «without prejudice, both
     exact unrounded decimal arithmetic (sometimes called fixed-point
     arithmetic) and rounded floating-point arithmetic.» – excerpt from
     the decimal arithmetic specification.

The module design is centered around three concepts: the decimal number,
the context for arithmetic, and signals.

A decimal number is immutable.  It has a sign, coefficient digits, and
an exponent.  To preserve significance, the coefficient digits do not
truncate trailing zeros.  Decimals also include special values such as
‘Infinity’, ‘-Infinity’, and ‘NaN’.  The standard also differentiates
‘-0’ from ‘+0’.

The context for arithmetic is an environment specifying precision,
rounding rules, limits on exponents, flags indicating the results of
operations, and trap enablers which determine whether signals are
treated as exceptions.  Rounding options include *note ROUND_CEILING:
2a96, *note ROUND_DOWN: 2a97, *note ROUND_FLOOR: 2a98, *note
ROUND_HALF_DOWN: 2a99, *note ROUND_HALF_EVEN: 2a9a, *note ROUND_HALF_UP:
2a9b, *note ROUND_UP: 2a9c, and *note ROUND_05UP: 2a9d.

Signals are groups of exceptional conditions arising during the course
of computation.  Depending on the needs of the application, signals may
be ignored, considered as informational, or treated as exceptions.  The
signals in the decimal module are: *note Clamped: 2a9e, *note
InvalidOperation: 12b0, *note DivisionByZero: 2a9f, *note Inexact: 2aa0,
*note Rounded: 2aa1, *note Subnormal: 2aa2, *note Overflow: 2aa3, *note
Underflow: 2aa4. and *note FloatOperation: 12a5.

For each signal there is a flag and a trap enabler.  When a signal is
encountered, its flag is set to one, then, if the trap enabler is set to
one, an exception is raised.  Flags are sticky, so the user needs to
reset them before monitoring a calculation.

Vedi anche
..........

   * IBM’s General Decimal Arithmetic Specification, The General Decimal
     Arithmetic Specification(3).

* Menu:

* Quick-start tutorial::
* Decimal objects::
* Context objects::
* Constants: Constants<4>.
* Rounding modes::
* Signals::
* Floating-point notes::
* Working with threads::
* Recipes::
* Decimal FAQ::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/decimal.py

   (2) https://speleotrove.com/decimal/damodel.html#refnumber

   (3) https://speleotrove.com/decimal/decarith.html


File: python.info,  Node: Quick-start tutorial,  Next: Decimal objects,  Up: decimal — Decimal fixed-point and floating-point arithmetic

5.9.4.1 Quick-start tutorial
............................

The usual start to using decimals is importing the module, viewing the
current context with *note getcontext(): 191f. and, if necessary,
setting new values for precision, rounding, or enabled traps:

     >>> from decimal import *
     >>> getcontext()
     Context(prec=28, rounding=ROUND_HALF_EVEN, Emin=-999999, Emax=999999,
             capitals=1, clamp=0, flags=[], traps=[Overflow, DivisionByZero,
             InvalidOperation])

     >>> getcontext().prec = 7       # Set a new precision

Decimal instances can be constructed from integers, strings, floats, or
tuples.  Construction from an integer or a float performs an exact
conversion of the value of that integer or float.  Decimal numbers
include special values such as ‘NaN’ which stands for «Not a number»,
positive and negative ‘Infinity’, and ‘-0’:

     >>> getcontext().prec = 28
     >>> Decimal(10)
     Decimal('10')
     >>> Decimal('3.14')
     Decimal('3.14')
     >>> Decimal(3.14)
     Decimal('3.140000000000000124344978758017532527446746826171875')
     >>> Decimal((0, (3, 1, 4), -2))
     Decimal('3.14')
     >>> Decimal(str(2.0 ** 0.5))
     Decimal('1.4142135623730951')
     >>> Decimal(2) ** Decimal('0.5')
     Decimal('1.414213562373095048801688724')
     >>> Decimal('NaN')
     Decimal('NaN')
     >>> Decimal('-Infinity')
     Decimal('-Infinity')

If the *note FloatOperation: 12a5. signal is trapped, accidental mixing
of decimals and floats in constructors or ordering comparisons raises an
exception:

     >>> c = getcontext()
     >>> c.traps[FloatOperation] = True
     >>> Decimal(3.14)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     decimal.FloatOperation: [<class 'decimal.FloatOperation'>]
     >>> Decimal('3.5') < 3.7
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     decimal.FloatOperation: [<class 'decimal.FloatOperation'>]
     >>> Decimal('3.5') == 3.5
     True

Added in version 3.3.

The significance of a new Decimal is determined solely by the number of
digits input.  Context precision and rounding only come into play during
arithmetic operations.

     >>> getcontext().prec = 6
     >>> Decimal('3.0')
     Decimal('3.0')
     >>> Decimal('3.1415926535')
     Decimal('3.1415926535')
     >>> Decimal('3.1415926535') + Decimal('2.7182818285')
     Decimal('5.85987')
     >>> getcontext().rounding = ROUND_UP
     >>> Decimal('3.1415926535') + Decimal('2.7182818285')
     Decimal('5.85988')

If the internal limits of the C version are exceeded, constructing a
decimal raises *note InvalidOperation: 12b0.:

     >>> Decimal("1e9999999999999999999")
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     decimal.InvalidOperation: [<class 'decimal.InvalidOperation'>]

Cambiato nella versione 3.3.

Decimals interact well with much of the rest of Python.  Here is a small
decimal floating-point flying circus:

     >>> data = list(map(Decimal, '1.34 1.87 3.45 2.35 1.00 0.03 9.25'.split()))
     >>> max(data)
     Decimal('9.25')
     >>> min(data)
     Decimal('0.03')
     >>> sorted(data)
     [Decimal('0.03'), Decimal('1.00'), Decimal('1.34'), Decimal('1.87'),
      Decimal('2.35'), Decimal('3.45'), Decimal('9.25')]
     >>> sum(data)
     Decimal('19.29')
     >>> a,b,c = data[:3]
     >>> str(a)
     '1.34'
     >>> float(a)
     1.34
     >>> round(a, 1)
     Decimal('1.3')
     >>> int(a)
     1
     >>> a * 5
     Decimal('6.70')
     >>> a * b
     Decimal('2.5058')
     >>> c % a
     Decimal('0.77')

Decimals can be formatted (with *note format(): 199. built-in or *note
f-strings: 19a.) in fixed-point or scientific notation, using the same
formatting syntax (see *note Format Specification Mini-Language: 4fa.)
as builtin *note float: 196. type:

     >>> format(Decimal('2.675'), "f")
     '2.675'
     >>> format(Decimal('2.675'), ".2f")
     '2.68'
     >>> f"{Decimal('2.675'):.2f}"
     '2.68'
     >>> format(Decimal('2.675'), ".2e")
     '2.68e+0'
     >>> with localcontext() as ctx:
     ...     ctx.rounding = ROUND_DOWN
     ...     print(format(Decimal('2.675'), ".2f"))
     ...
     2.67

And some mathematical functions are also available to Decimal:

     >>> getcontext().prec = 28
     >>> Decimal(2).sqrt()
     Decimal('1.414213562373095048801688724')
     >>> Decimal(1).exp()
     Decimal('2.718281828459045235360287471')
     >>> Decimal('10').ln()
     Decimal('2.302585092994045684017991455')
     >>> Decimal('10').log10()
     Decimal('1')

The *note quantize(): 12b8. method rounds a number to a fixed exponent.
This method is useful for monetary applications that often round results
to a fixed number of places:

     >>> Decimal('7.325').quantize(Decimal('.01'), rounding=ROUND_DOWN)
     Decimal('7.32')
     >>> Decimal('7.325').quantize(Decimal('1.'), rounding=ROUND_UP)
     Decimal('8')

As shown above, the *note getcontext(): 191f. function accesses the
current context and allows the settings to be changed.  This approach
meets the needs of most applications.

For more advanced work, it may be useful to create alternate contexts
using the *note Context(): 12b7. constructor.  To make an alternate
active, use the *note setcontext(): 2aa7. function.

In accordance with the standard, the *note decimal: 3a. module provides
two ready to use standard contexts, *note BasicContext: 12ac. and *note
ExtendedContext: 12ad.  The former is especially useful for debugging
because many of the traps are enabled:

     >>> myothercontext = Context(prec=60, rounding=ROUND_HALF_DOWN)
     >>> setcontext(myothercontext)
     >>> Decimal(1) / Decimal(7)
     Decimal('0.142857142857142857142857142857142857142857142857142857142857')

     >>> ExtendedContext
     Context(prec=9, rounding=ROUND_HALF_EVEN, Emin=-999999, Emax=999999,
             capitals=1, clamp=0, flags=[], traps=[])
     >>> setcontext(ExtendedContext)
     >>> Decimal(1) / Decimal(7)
     Decimal('0.142857143')
     >>> Decimal(42) / Decimal(0)
     Decimal('Infinity')

     >>> setcontext(BasicContext)
     >>> Decimal(42) / Decimal(0)
     Traceback (most recent call last):
       File "<pyshell#143>", line 1, in -toplevel-
         Decimal(42) / Decimal(0)
     DivisionByZero: x / 0

Contexts also have signal flags for monitoring exceptional conditions
encountered during computations.  The flags remain set until explicitly
cleared, so it is best to clear the flags before each set of monitored
computations by using the *note clear_flags(): 2aa8. method.

     >>> setcontext(ExtendedContext)
     >>> getcontext().clear_flags()
     >>> Decimal(355) / Decimal(113)
     Decimal('3.14159292')
     >>> getcontext()
     Context(prec=9, rounding=ROUND_HALF_EVEN, Emin=-999999, Emax=999999,
             capitals=1, clamp=0, flags=[Inexact, Rounded], traps=[])

The 'flags' entry shows that the rational approximation to pi was
rounded (digits beyond the context precision were thrown away) and that
the result is inexact (some of the discarded digits were non-zero).

Individual traps are set using the dictionary in the *note traps: 12b6.
attribute of a context:

     >>> setcontext(ExtendedContext)
     >>> Decimal(1) / Decimal(0)
     Decimal('Infinity')
     >>> getcontext().traps[DivisionByZero] = 1
     >>> Decimal(1) / Decimal(0)
     Traceback (most recent call last):
       File "<pyshell#112>", line 1, in -toplevel-
         Decimal(1) / Decimal(0)
     DivisionByZero: x / 0

Most programs adjust the current context only once, at the beginning of
the program.  And, in many applications, data is converted to *note
Decimal: 1fe. with a single cast inside a loop.  With context set and
decimals created, the bulk of the program manipulates the data no
differently than with other Python numeric types.


File: python.info,  Node: Decimal objects,  Next: Context objects,  Prev: Quick-start tutorial,  Up: decimal — Decimal fixed-point and floating-point arithmetic

5.9.4.2 Decimal objects
.......................

 -- Classe: decimal.Decimal (value='0', context=None)

     Construct a new *note Decimal: 1fe. object based from 'value'.

     'value' can be an integer, string, tuple, *note float: 196, or
     another *note Decimal: 1fe. object.  If no 'value' is given,
     returns ‘Decimal('0')’.  If 'value' is a string, it should conform
     to the decimal numeric string syntax after leading and trailing
     whitespace characters, as well as underscores throughout, are
     removed:

          sign           ::=  '+' | '-'
          digit          ::=  '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'
          indicator      ::=  'e' | 'E'
          digits         ::=  digit [digit]...
          decimal-part   ::=  digits '.' [digits] | ['.'] digits
          exponent-part  ::=  indicator [sign] digits
          infinity       ::=  'Infinity' | 'Inf'
          nan            ::=  'NaN' [digits] | 'sNaN' [digits]
          numeric-value  ::=  decimal-part [exponent-part] | infinity
          numeric-string ::=  [sign] numeric-value | [sign] nan

     Other Unicode decimal digits are also permitted where ‘digit’
     appears above.  These include decimal digits from various other
     alphabets (for example, Arabic-Indic and Devanāgarī digits) along
     with the fullwidth digits ‘'\uff10'’ through ‘'\uff19'’.  Case is
     not significant, so, for example, ‘inf’, ‘Inf’, ‘INFINITY’, and
     ‘iNfINity’ are all acceptable spellings for positive infinity.

     If 'value' is a *note tuple: 614, it should have three components,
     a sign (‘0’ for positive or ‘1’ for negative), a *note tuple: 614.
     of digits, and an integer exponent.  For example, ‘Decimal((0, (1,
     4, 1, 4), -3))’ returns ‘Decimal('1.414')’.

     If 'value' is a *note float: 196, the binary floating-point value
     is losslessly converted to its exact decimal equivalent.  This
     conversion can often require 53 or more digits of precision.  For
     example, ‘Decimal(float('1.1'))’ converts to
     ‘Decimal('1.100000000000000088817841970012523233890533447265625')’.

     The 'context' precision does not affect how many digits are stored.
     That is determined exclusively by the number of digits in 'value'.
     For example, ‘Decimal('3.00000')’ records all five zeros even if
     the context precision is only three.

     The purpose of the 'context' argument is determining what to do if
     'value' is a malformed string.  If the context traps *note
     InvalidOperation: 12b0, an exception is raised; otherwise, the
     constructor returns a new Decimal with the value of ‘NaN’.

     Once constructed, *note Decimal: 1fe. objects are immutable.

     Cambiato nella versione 3.2: The argument to the constructor is now
     permitted to be a *note float: 196. instance.

     Cambiato nella versione 3.3: *note float: 196. arguments raise an
     exception if the *note FloatOperation: 12a5. trap is set.  By
     default the trap is off.

     Cambiato nella versione 3.6: Underscores are allowed for grouping,
     as with integral and floating-point literals in code.

     Decimal floating-point objects share many properties with the other
     built-in numeric types such as *note float: 196. and *note int:
     19b.  All of the usual math operations and special methods apply.
     Likewise, decimal objects can be copied, pickled, printed, used as
     dictionary keys, used as set elements, compared, sorted, and
     coerced to another type (such as *note float: 196. or *note int:
     19b.).

     There are some small differences between arithmetic on Decimal
     objects and arithmetic on integers and floats.  When the remainder
     operator ‘%’ is applied to Decimal objects, the sign of the result
     is the sign of the 'dividend' rather than the sign of the divisor:

          >>> (-7) % 4
          1
          >>> Decimal(-7) % Decimal(4)
          Decimal('-3')

     The integer division operator ‘//’ behaves analogously, returning
     the integer part of the true quotient (truncating towards zero)
     rather than its floor, so as to preserve the usual identity ‘x ==
     (x // y) * y + x % y’:

          >>> -7 // 4
          -2
          >>> Decimal(-7) // Decimal(4)
          Decimal('-1')

     The ‘%’ and ‘//’ operators implement the ‘remainder’ and
     ‘divide-integer’ operations (respectively) as described in the
     specification.

     Decimal objects cannot generally be combined with floats or
     instances of *note fractions.Fraction: 213. in arithmetic
     operations: an attempt to add a *note Decimal: 1fe. to a *note
     float: 196, for example, will raise a *note TypeError: 198.
     However, it is possible to use Python’s comparison operators to
     compare a *note Decimal: 1fe. instance ‘x’ with another number ‘y’.
     This avoids confusing results when doing equality comparisons
     between numbers of different types.

     Cambiato nella versione 3.2: Mixed-type comparisons between *note
     Decimal: 1fe. instances and other numeric types are now fully
     supported.

     In addition to the standard numeric properties, decimal
     floating-point objects also have a number of specialized methods:

      -- Metodo: adjusted ()

          Return the adjusted exponent after shifting out the
          coefficient’s rightmost digits until only the lead digit
          remains: ‘Decimal('321e+5').adjusted()’ returns seven.  Used
          for determining the position of the most significant digit
          with respect to the decimal point.

      -- Metodo: as_integer_ratio ()

          Return a pair ‘(n, d)’ of integers that represent the given
          *note Decimal: 1fe. instance as a fraction, in lowest terms
          and with a positive denominator:

               >>> Decimal('-3.14').as_integer_ratio()
               (-157, 50)

          The conversion is exact.  Raise OverflowError on infinities
          and ValueError on NaNs.

     Added in version 3.6.

      -- Metodo: as_tuple ()

          Return a *note named tuple: 85f. representation of the number:
          ‘DecimalTuple(sign, digits, exponent)’.

      -- Metodo: canonical ()

          Return the canonical encoding of the argument.  Currently, the
          encoding of a *note Decimal: 1fe. instance is always
          canonical, so this operation returns its argument unchanged.

      -- Metodo: compare (other, context=None)

          Compare the values of two Decimal instances.  *note compare():
          2aae. returns a Decimal instance, and if either operand is a
          NaN then the result is a NaN:

               a or b is a NaN  ==> Decimal('NaN')
               a < b            ==> Decimal('-1')
               a == b           ==> Decimal('0')
               a > b            ==> Decimal('1')

      -- Metodo: compare_signal (other, context=None)

          This operation is identical to the *note compare(): 2aae.
          method, except that all NaNs signal.  That is, if neither
          operand is a signaling NaN then any quiet NaN operand is
          treated as though it were a signaling NaN.

      -- Metodo: compare_total (other, context=None)

          Compare two operands using their abstract representation
          rather than their numerical value.  Similar to the *note
          compare(): 2aae. method, but the result gives a total ordering
          on *note Decimal: 1fe. instances.  Two *note Decimal: 1fe.
          instances with the same numeric value but different
          representations compare unequal in this ordering:

               >>> Decimal('12.0').compare_total(Decimal('12'))
               Decimal('-1')

          Quiet and signaling NaNs are also included in the total
          ordering.  The result of this function is ‘Decimal('0')’ if
          both operands have the same representation, ‘Decimal('-1')’ if
          the first operand is lower in the total order than the second,
          and ‘Decimal('1')’ if the first operand is higher in the total
          order than the second operand.  See the specification for
          details of the total order.

          This operation is unaffected by context and is quiet: no flags
          are changed and no rounding is performed.  As an exception,
          the C version may raise InvalidOperation if the second operand
          cannot be converted exactly.

      -- Metodo: compare_total_mag (other, context=None)

          Compare two operands using their abstract representation
          rather than their value as in *note compare_total(): 2ab0, but
          ignoring the sign of each operand.  ‘x.compare_total_mag(y)’
          is equivalent to ‘x.copy_abs().compare_total(y.copy_abs())’.

          This operation is unaffected by context and is quiet: no flags
          are changed and no rounding is performed.  As an exception,
          the C version may raise InvalidOperation if the second operand
          cannot be converted exactly.

      -- Metodo: conjugate ()

          Just returns self, this method is only to comply with the
          Decimal Specification.

      -- Metodo: copy_abs ()

          Return the absolute value of the argument.  This operation is
          unaffected by the context and is quiet: no flags are changed
          and no rounding is performed.

      -- Metodo: copy_negate ()

          Return the negation of the argument.  This operation is
          unaffected by the context and is quiet: no flags are changed
          and no rounding is performed.

      -- Metodo: copy_sign (other, context=None)

          Return a copy of the first operand with the sign set to be the
          same as the sign of the second operand.  For example:

               >>> Decimal('2.3').copy_sign(Decimal('-1.5'))
               Decimal('-2.3')

          This operation is unaffected by context and is quiet: no flags
          are changed and no rounding is performed.  As an exception,
          the C version may raise InvalidOperation if the second operand
          cannot be converted exactly.

      -- Metodo: exp (context=None)

          Return the value of the (natural) exponential function ‘e**x’
          at the given number.  The result is correctly rounded using
          the *note ROUND_HALF_EVEN: 2a9a. rounding mode.

               >>> Decimal(1).exp()
               Decimal('2.718281828459045235360287471')
               >>> Decimal(321).exp()
               Decimal('2.561702493119680037517373933E+139')

      -- Metodo: classmethod from_float (f, /)

          Alternative constructor that only accepts instances of *note
          float: 196. or *note int: 19b.

          Note ‘Decimal.from_float(0.1)’ is not the same as
          ‘Decimal('0.1')’.  Since 0.1 is not exactly representable in
          binary floating point, the value is stored as the nearest
          representable value which is ‘0x1.999999999999ap-4’.  That
          equivalent value in decimal is
          ‘0.1000000000000000055511151231257827021181583404541015625’.

               Nota: From Python 3.2 onwards, a *note Decimal: 1fe.
               instance can also be constructed directly from a *note
               float: 196.

               >>> Decimal.from_float(0.1)
               Decimal('0.1000000000000000055511151231257827021181583404541015625')
               >>> Decimal.from_float(float('nan'))
               Decimal('NaN')
               >>> Decimal.from_float(float('inf'))
               Decimal('Infinity')
               >>> Decimal.from_float(float('-inf'))
               Decimal('-Infinity')

          Added in version 3.1.

      -- Metodo: classmethod from_number (number, /)

          Alternative constructor that only accepts instances of *note
          float: 196, *note int: 19b. or *note Decimal: 1fe, but not
          strings or tuples.

               >>> Decimal.from_number(314)
               Decimal('314')
               >>> Decimal.from_number(0.1)
               Decimal('0.1000000000000000055511151231257827021181583404541015625')
               >>> Decimal.from_number(Decimal('3.14'))
               Decimal('3.14')

          Added in version 3.14.

      -- Metodo: fma (other, third, context=None)

          Fused multiply-add.  Return self*other+third with no rounding
          of the intermediate product self*other.

               >>> Decimal(2).fma(3, 5)
               Decimal('11')

      -- Metodo: is_canonical ()

          Return *note True: e09. if the argument is canonical and *note
          False: d2d. otherwise.  Currently, a *note Decimal: 1fe.
          instance is always canonical, so this operation always returns
          *note True: e09.

      -- Metodo: is_finite ()

          Return *note True: e09. if the argument is a finite number,
          and *note False: d2d. if the argument is an infinity or a NaN.

      -- Metodo: is_infinite ()

          Return *note True: e09. if the argument is either positive or
          negative infinity and *note False: d2d. otherwise.

      -- Metodo: is_nan ()

          Return *note True: e09. if the argument is a (quiet or
          signaling) NaN and *note False: d2d. otherwise.

      -- Metodo: is_normal (context=None)

          Return *note True: e09. if the argument is a 'normal' finite
          number.  Return *note False: d2d. if the argument is zero,
          subnormal, infinite or a NaN.

      -- Metodo: is_qnan ()

          Return *note True: e09. if the argument is a quiet NaN, and
          *note False: d2d. otherwise.

      -- Metodo: is_signed ()

          Return *note True: e09. if the argument has a negative sign
          and *note False: d2d. otherwise.  Note that zeros and NaNs can
          both carry signs.

      -- Metodo: is_snan ()

          Return *note True: e09. if the argument is a signaling NaN and
          *note False: d2d. otherwise.

      -- Metodo: is_subnormal (context=None)

          Return *note True: e09. if the argument is subnormal, and
          *note False: d2d. otherwise.

      -- Metodo: is_zero ()

          Return *note True: e09. if the argument is a (positive or
          negative) zero and *note False: d2d. otherwise.

      -- Metodo: ln (context=None)

          Return the natural (base e) logarithm of the operand.  The
          result is correctly rounded using the *note ROUND_HALF_EVEN:
          2a9a. rounding mode.

      -- Metodo: log10 (context=None)

          Return the base ten logarithm of the operand.  The result is
          correctly rounded using the *note ROUND_HALF_EVEN: 2a9a.
          rounding mode.

      -- Metodo: logb (context=None)

          For a nonzero number, return the adjusted exponent of its
          operand as a *note Decimal: 1fe. instance.  If the operand is
          a zero then ‘Decimal('-Infinity')’ is returned and the *note
          DivisionByZero: 2a9f. flag is raised.  If the operand is an
          infinity then ‘Decimal('Infinity')’ is returned.

      -- Metodo: logical_and (other, context=None)

          *note logical_and(): 2ac3. is a logical operation which takes
          two 'logical operands' (see *note Logical operands: 2ac4.).
          The result is the digit-wise ‘and’ of the two operands.

      -- Metodo: logical_invert (context=None)

          *note logical_invert(): 2ac5. is a logical operation.  The
          result is the digit-wise inversion of the operand.

      -- Metodo: logical_or (other, context=None)

          *note logical_or(): 2ac6. is a logical operation which takes
          two 'logical operands' (see *note Logical operands: 2ac4.).
          The result is the digit-wise ‘or’ of the two operands.

      -- Metodo: logical_xor (other, context=None)

          *note logical_xor(): 2ac7. is a logical operation which takes
          two 'logical operands' (see *note Logical operands: 2ac4.).
          The result is the digit-wise exclusive or of the two operands.

      -- Metodo: max (other, context=None)

          Like ‘max(self, other)’ except that the context rounding rule
          is applied before returning and that ‘NaN’ values are either
          signaled or ignored (depending on the context and whether they
          are signaling or quiet).

      -- Metodo: max_mag (other, context=None)

          Similar to the *note max(): 2ac8. method, but the comparison
          is done using the absolute values of the operands.

      -- Metodo: min (other, context=None)

          Like ‘min(self, other)’ except that the context rounding rule
          is applied before returning and that ‘NaN’ values are either
          signaled or ignored (depending on the context and whether they
          are signaling or quiet).

      -- Metodo: min_mag (other, context=None)

          Similar to the *note min(): 2aca. method, but the comparison
          is done using the absolute values of the operands.

      -- Metodo: next_minus (context=None)

          Return the largest number representable in the given context
          (or in the current thread’s context if no context is given)
          that is smaller than the given operand.

      -- Metodo: next_plus (context=None)

          Return the smallest number representable in the given context
          (or in the current thread’s context if no context is given)
          that is larger than the given operand.

      -- Metodo: next_toward (other, context=None)

          If the two operands are unequal, return the number closest to
          the first operand in the direction of the second operand.  If
          both operands are numerically equal, return a copy of the
          first operand with the sign set to be the same as the sign of
          the second operand.

      -- Metodo: normalize (context=None)

          Used for producing canonical values of an equivalence class
          within either the current context or the specified context.

          This has the same semantics as the unary plus operation,
          except that if the final result is finite it is reduced to its
          simplest form, with all trailing zeros removed and its sign
          preserved.  That is, while the coefficient is non-zero and a
          multiple of ten the coefficient is divided by ten and the
          exponent is incremented by 1.  Otherwise (the coefficient is
          zero) the exponent is set to 0.  In all cases the sign is
          unchanged.

          For example, ‘Decimal('32.100')’ and ‘Decimal('0.321000e+2')’
          both normalize to the equivalent value ‘Decimal('32.1')’.

          Note that rounding is applied 'before' reducing to simplest
          form.

          In the latest versions of the specification, this operation is
          also known as ‘reduce’.

      -- Metodo: number_class (context=None)

          Return a string describing the 'class' of the operand.  The
          returned value is one of the following ten strings.

             * ‘"-Infinity"’, indicating that the operand is negative
               infinity.

             * ‘"-Normal"’, indicating that the operand is a negative
               normal number.

             * ‘"-Subnormal"’, indicating that the operand is negative
               and subnormal.

             * ‘"-Zero"’, indicating that the operand is a negative
               zero.

             * ‘"+Zero"’, indicating that the operand is a positive
               zero.

             * ‘"+Subnormal"’, indicating that the operand is positive
               and subnormal.

             * ‘"+Normal"’, indicating that the operand is a positive
               normal number.

             * ‘"+Infinity"’, indicating that the operand is positive
               infinity.

             * ‘"NaN"’, indicating that the operand is a quiet NaN (Not
               a Number).

             * ‘"sNaN"’, indicating that the operand is a signaling NaN.

      -- Metodo: quantize (exp, rounding=None, context=None)

          Return a value equal to the first operand after rounding and
          having the exponent of the second operand.

               >>> Decimal('1.41421356').quantize(Decimal('1.000'))
               Decimal('1.414')

          Unlike other operations, if the length of the coefficient
          after the quantize operation would be greater than precision,
          then an *note InvalidOperation: 12b0. is signaled.  This
          guarantees that, unless there is an error condition, the
          quantized exponent is always equal to that of the right-hand
          operand.

          Also unlike other operations, quantize never signals
          Underflow, even if the result is subnormal and inexact.

          If the exponent of the second operand is larger than that of
          the first then rounding may be necessary.  In this case, the
          rounding mode is determined by the ‘rounding’ argument if
          given, else by the given ‘context’ argument; if neither
          argument is given the rounding mode of the current thread’s
          context is used.

          An error is returned whenever the resulting exponent is
          greater than *note Emax: 12ae. or less than *note Etiny():
          2ad1.

      -- Metodo: radix ()

          Return ‘Decimal(10)’, the radix (base) in which the *note
          Decimal: 1fe. class does all its arithmetic.  Included for
          compatibility with the specification.

      -- Metodo: remainder_near (other, context=None)

          Return the remainder from dividing 'self' by 'other'.  This
          differs from ‘self % other’ in that the sign of the remainder
          is chosen so as to minimize its absolute value.  More
          precisely, the return value is ‘self - n * other’ where ‘n’ is
          the integer nearest to the exact value of ‘self / other’, and
          if two integers are equally near then the even one is chosen.

          If the result is zero then its sign will be the sign of
          'self'.

               >>> Decimal(18).remainder_near(Decimal(10))
               Decimal('-2')
               >>> Decimal(25).remainder_near(Decimal(10))
               Decimal('5')
               >>> Decimal(35).remainder_near(Decimal(10))
               Decimal('-5')

      -- Metodo: rotate (other, context=None)

          Return the result of rotating the digits of the first operand
          by an amount specified by the second operand.  The second
          operand must be an integer in the range -precision through
          precision.  The absolute value of the second operand gives the
          number of places to rotate.  If the second operand is positive
          then rotation is to the left; otherwise rotation is to the
          right.  The coefficient of the first operand is padded on the
          left with zeros to length precision if necessary.  The sign
          and exponent of the first operand are unchanged.

      -- Metodo: same_quantum (other, context=None)

          Test whether self and other have the same exponent or whether
          both are ‘NaN’.

          This operation is unaffected by context and is quiet: no flags
          are changed and no rounding is performed.  As an exception,
          the C version may raise InvalidOperation if the second operand
          cannot be converted exactly.

      -- Metodo: scaleb (other, context=None)

          Return the first operand with exponent adjusted by the second.
          Equivalently, return the first operand multiplied by
          ‘10**other’.  The second operand must be an integer.

      -- Metodo: shift (other, context=None)

          Return the result of shifting the digits of the first operand
          by an amount specified by the second operand.  The second
          operand must be an integer in the range -precision through
          precision.  The absolute value of the second operand gives the
          number of places to shift.  If the second operand is positive
          then the shift is to the left; otherwise the shift is to the
          right.  Digits shifted into the coefficient are zeros.  The
          sign and exponent of the first operand are unchanged.

      -- Metodo: sqrt (context=None)

          Return the square root of the argument to full precision.

      -- Metodo: to_eng_string (context=None)

          Convert to a string, using engineering notation if an exponent
          is needed.

          Engineering notation has an exponent which is a multiple of 3.
          This can leave up to 3 digits to the left of the decimal place
          and may require the addition of either one or two trailing
          zeros.

          For example, this converts ‘Decimal('123E+1')’ to
          ‘Decimal('1.23E+3')’.

      -- Metodo: to_integral (rounding=None, context=None)

          Identical to the *note to_integral_value(): 2adb. method.  The
          ‘to_integral’ name has been kept for compatibility with older
          versions.

      -- Metodo: to_integral_exact (rounding=None, context=None)

          Round to the nearest integer, signaling *note Inexact: 2aa0.
          or *note Rounded: 2aa1. as appropriate if rounding occurs.
          The rounding mode is determined by the ‘rounding’ parameter if
          given, else by the given ‘context’.  If neither parameter is
          given then the rounding mode of the current context is used.

      -- Metodo: to_integral_value (rounding=None, context=None)

          Round to the nearest integer without signaling *note Inexact:
          2aa0. or *note Rounded: 2aa1.  If given, applies 'rounding';
          otherwise, uses the rounding method in either the supplied
          'context' or the current context.

     Decimal numbers can be rounded using the *note round(): 14e2.
     function:

      -- Describe: round(number)

      -- Describe: round(number, ndigits)

          If 'ndigits' is not given or ‘None’, returns the nearest *note
          int: 19b. to 'number', rounding ties to even, and ignoring the
          rounding mode of the *note Decimal: 1fe. context.  Raises
          *note OverflowError: a83. if 'number' is an infinity or *note
          ValueError: 2ec. if it is a (quiet or signaling) NaN.

          If 'ndigits' is an *note int: 19b, the context’s rounding mode
          is respected and a *note Decimal: 1fe. representing 'number'
          rounded to the nearest multiple of ‘Decimal('1E-ndigits')’ is
          returned; in this case, ‘round(number, ndigits)’ is equivalent
          to ‘self.quantize(Decimal('1E-ndigits'))’.  Returns
          ‘Decimal('NaN')’ if 'number' is a quiet NaN. Raises *note
          InvalidOperation: 12b0. if 'number' is an infinity, a
          signaling NaN, or if the length of the coefficient after the
          quantize operation would be greater than the current context’s
          precision.  In other words, for the non-corner cases:

             * if 'ndigits' is positive, return 'number' rounded to
               'ndigits' decimal places;

             * if 'ndigits' is zero, return 'number' rounded to the
               nearest integer;

             * if 'ndigits' is negative, return 'number' rounded to the
               nearest multiple of ‘10**abs(ndigits)’.

          For example:

               >>> from decimal import Decimal, getcontext, ROUND_DOWN
               >>> getcontext().rounding = ROUND_DOWN
               >>> round(Decimal('3.75'))     # context rounding ignored
               4
               >>> round(Decimal('3.5'))      # round-ties-to-even
               4
               >>> round(Decimal('3.75'), 0)  # uses the context rounding
               Decimal('3')
               >>> round(Decimal('3.75'), 1)
               Decimal('3.7')
               >>> round(Decimal('3.75'), -1)
               Decimal('0E+1')

* Menu:

* Logical operands::


File: python.info,  Node: Logical operands,  Up: Decimal objects

5.9.4.3 Logical operands
........................

The *note logical_and(): 2ac3, *note logical_invert(): 2ac5, *note
logical_or(): 2ac6, and *note logical_xor(): 2ac7. methods expect their
arguments to be 'logical operands'.  A 'logical operand' is a *note
Decimal: 1fe. instance whose exponent and sign are both zero, and whose
digits are all either ‘0’ or ‘1’.


File: python.info,  Node: Context objects,  Next: Constants<4>,  Prev: Decimal objects,  Up: decimal — Decimal fixed-point and floating-point arithmetic

5.9.4.4 Context objects
.......................

Contexts are environments for arithmetic operations.  They govern
precision, set rules for rounding, determine which signals are treated
as exceptions, and limit the range for exponents.

Each thread has its own current context which is accessed or changed
using the *note getcontext(): 191f. and *note setcontext(): 2aa7.
functions:

 -- Funzione: decimal.getcontext ()

     Return the current context for the active thread.

 -- Funzione: decimal.setcontext (c, /)

     Set the current context for the active thread to 'c'.

You can also use the *note with: 186. statement and the *note
localcontext(): 158e. function to temporarily change the active context.

 -- Funzione: decimal.localcontext (ctx=None, **kwargs)

     Return a context manager that will set the current context for the
     active thread to a copy of 'ctx' on entry to the with-statement and
     restore the previous context when exiting the with-statement.  If
     no context is specified, a copy of the current context is used.
     The 'kwargs' argument is used to set the attributes of the new
     context.

     For example, the following code sets the current decimal precision
     to 42 places, performs a calculation, and then automatically
     restores the previous context:

          from decimal import localcontext

          with localcontext() as ctx:
              ctx.prec = 42   # Perform a high precision calculation
              s = calculate_something()
          s = +s  # Round the final result back to the default precision

     Using keyword arguments, the code would be the following:

          from decimal import localcontext

          with localcontext(prec=42) as ctx:
              s = calculate_something()
          s = +s

     Raises *note TypeError: 198. if 'kwargs' supplies an attribute that
     *note Context: 12b7. doesn’t support.  Raises either *note
     TypeError: 198. or *note ValueError: 2ec. if 'kwargs' supplies an
     invalid value for an attribute.

     Cambiato nella versione 3.11: *note localcontext(): 158e. now
     supports setting context attributes through the use of keyword
     arguments.

 -- Funzione: decimal.IEEEContext (bits)

     Return a context object initialized to the proper values for one of
     the IEEE interchange formats.  The argument must be a multiple of
     32 and less than *note IEEE_CONTEXT_MAX_BITS: 2adf.

     Added in version 3.14.

New contexts can also be created using the *note Context: 12b7.
constructor described below.  In addition, the module provides three
pre-made contexts:

 -- Dati: decimal.BasicContext

     This is a standard context defined by the General Decimal
     Arithmetic Specification.  Precision is set to nine.  Rounding is
     set to *note ROUND_HALF_UP: 2a9b.  All flags are cleared.  All
     traps are enabled (treated as exceptions) except *note Inexact:
     2aa0, *note Rounded: 2aa1, and *note Subnormal: 2aa2.

     Because many of the traps are enabled, this context is useful for
     debugging.

 -- Dati: decimal.ExtendedContext

     This is a standard context defined by the General Decimal
     Arithmetic Specification.  Precision is set to nine.  Rounding is
     set to *note ROUND_HALF_EVEN: 2a9a.  All flags are cleared.  No
     traps are enabled (so that exceptions are not raised during
     computations).

     Because the traps are disabled, this context is useful for
     applications that prefer to have result value of ‘NaN’ or
     ‘Infinity’ instead of raising exceptions.  This allows an
     application to complete a run in the presence of conditions that
     would otherwise halt the program.

 -- Dati: decimal.DefaultContext

     This context is used by the *note Context: 12b7. constructor as a
     prototype for new contexts.  Changing a field (such a precision)
     has the effect of changing the default for new contexts created by
     the *note Context: 12b7. constructor.

     This context is most useful in multi-threaded environments.
     Changing one of the fields before threads are started has the
     effect of setting system-wide defaults.  Changing the fields after
     threads have started is not recommended as it would require thread
     synchronization to prevent race conditions.

     In single threaded environments, it is preferable to not use this
     context at all.  Instead, simply create contexts explicitly as
     described below.

     The default values are *note Context.prec: 2ae0.=‘28’, *note
     Context.rounding: 2ae1.=*note ROUND_HALF_EVEN: 2a9a, and enabled
     traps for *note Overflow: 2aa3, *note InvalidOperation: 12b0, and
     *note DivisionByZero: 2a9f.

In addition to the three supplied contexts, new contexts can be created
with the *note Context: 12b7. constructor.

 -- Classe: decimal.Context (prec=None, rounding=None, Emin=None,
          Emax=None, capitals=None, clamp=None, flags=None, traps=None)

     Creates a new context.  If a field is not specified or is *note
     None: 886, the default values are copied from the *note
     DefaultContext: 12ab.  If the 'flags' field is not specified or is
     *note None: 886, all flags are cleared.

      -- Attributo: prec

          An integer in the range [‘1’, *note MAX_PREC: 12a8.] that sets
          the precision for arithmetic operations in the context.

      -- Attributo: rounding

          One of the constants listed in the section *note Rounding
          Modes: 2ae2.

      -- Attributo: traps
      -- Attributo: flags

          Lists of any signals to be set.  Generally, new contexts
          should only set traps and leave the flags clear.

      -- Attributo: Emin
      -- Attributo: Emax

          Integers specifying the outer limits allowable for exponents.
          'Emin' must be in the range [*note MIN_EMIN: 12aa, ‘0’],
          'Emax' in the range [‘0’, *note MAX_EMAX: 12a9.].

      -- Attributo: capitals

          Either ‘0’ or ‘1’ (the default).  If set to ‘1’, exponents are
          printed with a capital ‘E’; otherwise, a lowercase ‘e’ is
          used: ‘Decimal('6.02e+23')’.

      -- Attributo: clamp

          Either ‘0’ (the default) or ‘1’.  If set to ‘1’, the exponent
          ‘e’ of a *note Decimal: 1fe. instance representable in this
          context is strictly limited to the range ‘Emin - prec + 1 <= e
          <= Emax - prec + 1’.  If 'clamp' is ‘0’ then a weaker
          condition holds: the adjusted exponent of the *note Decimal:
          1fe. instance is at most *note Emax: 12ae.  When 'clamp' is
          ‘1’, a large normal number will, where possible, have its
          exponent reduced and a corresponding number of zeros added to
          its coefficient, in order to fit the exponent constraints;
          this preserves the value of the number but loses information
          about significant trailing zeros.  For example:

               >>> Context(prec=6, Emax=999, clamp=1).create_decimal('1.23e999')
               Decimal('1.23000E+999')

          A 'clamp' value of ‘1’ allows compatibility with the
          fixed-width decimal interchange formats specified in IEEE 754.

     The *note Context: 12b7. class defines several general purpose
     methods as well as a large number of methods for doing arithmetic
     directly in a given context.  In addition, for each of the *note
     Decimal: 1fe. methods described above (with the exception of the
     *note adjusted(): 2aab. and *note as_tuple(): 2aac. methods) there
     is a corresponding *note Context: 12b7. method.  For example, for a
     *note Context: 12b7. instance ‘C’ and *note Decimal: 1fe. instance
     ‘x’, ‘C.exp(x)’ is equivalent to ‘x.exp(context=C)’.  Each *note
     Context: 12b7. method accepts a Python integer (an instance of
     *note int: 19b.) anywhere that a Decimal instance is accepted.

      -- Metodo: clear_flags ()

          Resets all of the flags to ‘0’.

      -- Metodo: clear_traps ()

          Resets all of the traps to ‘0’.

          Added in version 3.3.

      -- Metodo: copy ()

          Return a duplicate of the context.

      -- Metodo: copy_decimal (num, /)

          Return a copy of the Decimal instance num.

      -- Metodo: create_decimal (num='0', /)

          Creates a new Decimal instance from 'num' but using 'self' as
          context.  Unlike the *note Decimal: 1fe. constructor, the
          context precision, rounding method, flags, and traps are
          applied to the conversion.

          This is useful because constants are often given to a greater
          precision than is needed by the application.  Another benefit
          is that rounding immediately eliminates unintended effects
          from digits beyond the current precision.  In the following
          example, using unrounded inputs means that adding zero to a
          sum can change the result:

               >>> getcontext().prec = 3
               >>> Decimal('3.4445') + Decimal('1.0023')
               Decimal('4.45')
               >>> Decimal('3.4445') + Decimal(0) + Decimal('1.0023')
               Decimal('4.44')

          This method implements the to-number operation of the IBM
          specification.  If the argument is a string, no leading or
          trailing whitespace or underscores are permitted.

      -- Metodo: create_decimal_from_float (f, /)

          Creates a new Decimal instance from a float 'f' but rounding
          using 'self' as the context.  Unlike the *note
          Decimal.from_float(): 140c. class method, the context
          precision, rounding method, flags, and traps are applied to
          the conversion.

               >>> context = Context(prec=5, rounding=ROUND_DOWN)
               >>> context.create_decimal_from_float(math.pi)
               Decimal('3.1415')
               >>> context = Context(prec=5, traps=[Inexact])
               >>> context.create_decimal_from_float(math.pi)
               Traceback (most recent call last):
                   ...
               decimal.Inexact: None

          Added in version 3.1.

      -- Metodo: Etiny ()

          Returns a value equal to ‘Emin - prec + 1’ which is the
          minimum exponent value for subnormal results.  When underflow
          occurs, the exponent is set to *note Etiny: 2ad1.

      -- Metodo: Etop ()

          Returns a value equal to ‘Emax - prec + 1’.

     The usual approach to working with decimals is to create *note
     Decimal: 1fe. instances and then apply arithmetic operations which
     take place within the current context for the active thread.  An
     alternative approach is to use context methods for calculating
     within a specific context.  The methods are similar to those for
     the *note Decimal: 1fe. class and are only briefly recounted here.

      -- Metodo: abs (x, /)

          Returns the absolute value of 'x'.

      -- Metodo: add (x, y, /)

          Return the sum of 'x' and 'y'.

      -- Metodo: canonical (x, /)

          Returns the same Decimal object 'x'.

      -- Metodo: compare (x, y, /)

          Compares 'x' and 'y' numerically.

      -- Metodo: compare_signal (x, y, /)

          Compares the values of the two operands numerically.

      -- Metodo: compare_total (x, y, /)

          Compares two operands using their abstract representation.

      -- Metodo: compare_total_mag (x, y, /)

          Compares two operands using their abstract representation,
          ignoring sign.

      -- Metodo: copy_abs (x, /)

          Returns a copy of 'x' with the sign set to 0.

      -- Metodo: copy_negate (x, /)

          Returns a copy of 'x' with the sign inverted.

      -- Metodo: copy_sign (x, y, /)

          Copies the sign from 'y' to 'x'.

      -- Metodo: divide (x, y, /)

          Return 'x' divided by 'y'.

      -- Metodo: divide_int (x, y, /)

          Return 'x' divided by 'y', truncated to an integer.

      -- Metodo: divmod (x, y, /)

          Divides two numbers and returns the integer part of the
          result.

      -- Metodo: exp (x, /)

          Returns ‘e ** x’.

      -- Metodo: fma (x, y, z, /)

          Returns 'x' multiplied by 'y', plus 'z'.

      -- Metodo: is_canonical (x, /)

          Returns ‘True’ if 'x' is canonical; otherwise returns ‘False’.

      -- Metodo: is_finite (x, /)

          Returns ‘True’ if 'x' is finite; otherwise returns ‘False’.

      -- Metodo: is_infinite (x, /)

          Returns ‘True’ if 'x' is infinite; otherwise returns ‘False’.

      -- Metodo: is_nan (x, /)

          Returns ‘True’ if 'x' is a qNaN or sNaN; otherwise returns
          ‘False’.

      -- Metodo: is_normal (x, /)

          Returns ‘True’ if 'x' is a normal number; otherwise returns
          ‘False’.

      -- Metodo: is_qnan (x, /)

          Returns ‘True’ if 'x' is a quiet NaN; otherwise returns
          ‘False’.

      -- Metodo: is_signed (x, /)

          Returns ‘True’ if 'x' is negative; otherwise returns ‘False’.

      -- Metodo: is_snan (x, /)

          Returns ‘True’ if 'x' is a signaling NaN; otherwise returns
          ‘False’.

      -- Metodo: is_subnormal (x, /)

          Returns ‘True’ if 'x' is subnormal; otherwise returns ‘False’.

      -- Metodo: is_zero (x, /)

          Returns ‘True’ if 'x' is a zero; otherwise returns ‘False’.

      -- Metodo: ln (x, /)

          Returns the natural (base e) logarithm of 'x'.

      -- Metodo: log10 (x, /)

          Returns the base 10 logarithm of 'x'.

      -- Metodo: logb (x, /)

          Returns the exponent of the magnitude of the operand’s MSD.

      -- Metodo: logical_and (x, y, /)

          Applies the logical operation 'and' between each operand’s
          digits.

      -- Metodo: logical_invert (x, /)

          Invert all the digits in 'x'.

      -- Metodo: logical_or (x, y, /)

          Applies the logical operation 'or' between each operand’s
          digits.

      -- Metodo: logical_xor (x, y, /)

          Applies the logical operation 'xor' between each operand’s
          digits.

      -- Metodo: max (x, y, /)

          Compares two values numerically and returns the maximum.

      -- Metodo: max_mag (x, y, /)

          Compares the values numerically with their sign ignored.

      -- Metodo: min (x, y, /)

          Compares two values numerically and returns the minimum.

      -- Metodo: min_mag (x, y, /)

          Compares the values numerically with their sign ignored.

      -- Metodo: minus (x, /)

          Minus corresponds to the unary prefix minus operator in
          Python.

      -- Metodo: multiply (x, y, /)

          Return the product of 'x' and 'y'.

      -- Metodo: next_minus (x, /)

          Returns the largest representable number smaller than 'x'.

      -- Metodo: next_plus (x, /)

          Returns the smallest representable number larger than 'x'.

      -- Metodo: next_toward (x, y, /)

          Returns the number closest to 'x', in direction towards 'y'.

      -- Metodo: normalize (x, /)

          Reduces 'x' to its simplest form.

      -- Metodo: number_class (x, /)

          Returns an indication of the class of 'x'.

      -- Metodo: plus (x, /)

          Plus corresponds to the unary prefix plus operator in Python.
          This operation applies the context precision and rounding, so
          it is 'not' an identity operation.

      -- Metodo: power (x, y, modulo=None)

          Return ‘x’ to the power of ‘y’, reduced modulo ‘modulo’ if
          given.

          With two arguments, compute ‘x**y’.  If ‘x’ is negative then
          ‘y’ must be integral.  The result will be inexact unless ‘y’
          is integral and the result is finite and can be expressed
          exactly in “precision” digits.  The rounding mode of the
          context is used.  Results are always correctly rounded in the
          Python version.

          ‘Decimal(0) ** Decimal(0)’ results in ‘InvalidOperation’, and
          if ‘InvalidOperation’ is not trapped, then results in
          ‘Decimal('NaN')’.

          Cambiato nella versione 3.3: The C module computes *note
          power(): 2b13. in terms of the correctly rounded *note exp():
          2af5. and *note ln(): 2b00. functions.  The result is
          well-defined but only «almost always correctly rounded».

          With three arguments, compute ‘(x**y) % modulo’.  For the
          three argument form, the following restrictions on the
          arguments hold:

             - all three arguments must be integral

             - ‘y’ must be nonnegative

             - at least one of ‘x’ or ‘y’ must be nonzero

             - ‘modulo’ must be nonzero and have at most “precision”
               digits

          The value resulting from ‘Context.power(x, y, modulo)’ is
          equal to the value that would be obtained by computing ‘(x**y)
          % modulo’ with unbounded precision, but is computed more
          efficiently.  The exponent of the result is zero, regardless
          of the exponents of ‘x’, ‘y’ and ‘modulo’.  The result is
          always exact.

      -- Metodo: quantize (x, y, /)

          Returns a value equal to 'x' (rounded), having the exponent of
          'y'.

      -- Metodo: radix ()

          Just returns 10, as this is Decimal, :)

      -- Metodo: remainder (x, y, /)

          Returns the remainder from integer division.

          The sign of the result, if non-zero, is the same as that of
          the original dividend.

      -- Metodo: remainder_near (x, y, /)

          Returns ‘x - y * n’, where 'n' is the integer nearest the
          exact value of ‘x / y’ (if the result is 0 then its sign will
          be the sign of 'x').

      -- Metodo: rotate (x, y, /)

          Returns a rotated copy of 'x', 'y' times.

      -- Metodo: same_quantum (x, y, /)

          Returns ‘True’ if the two operands have the same exponent.

      -- Metodo: scaleb (x, y, /)

          Returns the first operand after adding the second value its
          exp.

      -- Metodo: shift (x, y, /)

          Returns a shifted copy of 'x', 'y' times.

      -- Metodo: sqrt (x, /)

          Square root of a non-negative number to context precision.

      -- Metodo: subtract (x, y, /)

          Return the difference between 'x' and 'y'.

      -- Metodo: to_eng_string (x, /)

          Convert to a string, using engineering notation if an exponent
          is needed.

          Engineering notation has an exponent which is a multiple of 3.
          This can leave up to 3 digits to the left of the decimal place
          and may require the addition of either one or two trailing
          zeros.

      -- Metodo: to_integral_exact (x, /)

          Rounds to an integer.

      -- Metodo: to_sci_string (x, /)

          Converts a number to a string using scientific notation.


File: python.info,  Node: Constants<4>,  Next: Rounding modes,  Prev: Context objects,  Up: decimal — Decimal fixed-point and floating-point arithmetic

5.9.4.5 Constants
.................

The constants in this section are only relevant for the C module.  They
are also included in the pure Python version for compatibility.

                                      32-bit                    64-bit
                                                                
----------------------------------------------------------------------------------------------------
                                                                
 -- Dati: decimal.MAX_PREC            ‘425000000’               ‘999999999999999999’
                                                                
                                                                
 -- Dati: decimal.MAX_EMAX            ‘425000000’               ‘999999999999999999’
                                                                
                                                                
 -- Dati: decimal.MIN_EMIN            ‘-425000000’              ‘-999999999999999999’
                                                                
                                                                
 -- Dati: decimal.MIN_ETINY           ‘-849999999’              ‘-1999999999999999997’
                                                                
                                                                
 -- Dati:                             ‘256’                     ‘512’
          decimal.IEEE_CONTEXT_MAX_BITS                         

 -- Dati: decimal.HAVE_THREADS

     The value is ‘True’.  Deprecated, because Python now always has
     threads.

     Deprecato dalla versione 3.9.

 -- Dati: decimal.HAVE_CONTEXTVAR

     The default value is ‘True’.  If Python is *note configured using
     the -without-decimal-contextvar option: 2151, the C version uses a
     thread-local rather than a coroutine-local context and the value is
     ‘False’.  This is slightly faster in some nested context scenarios.

     Added in version 3.8.3.


File: python.info,  Node: Rounding modes,  Next: Signals,  Prev: Constants<4>,  Up: decimal — Decimal fixed-point and floating-point arithmetic

5.9.4.6 Rounding modes
......................

 -- Dati: decimal.ROUND_CEILING

     Round towards ‘Infinity’.

 -- Dati: decimal.ROUND_DOWN

     Round towards zero.

 -- Dati: decimal.ROUND_FLOOR

     Round towards ‘-Infinity’.

 -- Dati: decimal.ROUND_HALF_DOWN

     Round to nearest with ties going towards zero.

 -- Dati: decimal.ROUND_HALF_EVEN

     Round to nearest with ties going to nearest even integer.

 -- Dati: decimal.ROUND_HALF_UP

     Round to nearest with ties going away from zero.

 -- Dati: decimal.ROUND_UP

     Round away from zero.

 -- Dati: decimal.ROUND_05UP

     Round away from zero if last digit after rounding towards zero
     would have been 0 or 5; otherwise round towards zero.


File: python.info,  Node: Signals,  Next: Floating-point notes,  Prev: Rounding modes,  Up: decimal — Decimal fixed-point and floating-point arithmetic

5.9.4.7 Signals
...............

Signals represent conditions that arise during computation.  Each
corresponds to one context flag and one context trap enabler.

The context flag is set whenever the condition is encountered.  After
the computation, flags may be checked for informational purposes (for
instance, to determine whether a computation was exact).  After checking
the flags, be sure to clear all flags before starting the next
computation.

If the context’s trap enabler is set for the signal, then the condition
causes a Python exception to be raised.  For example, if the *note
DivisionByZero: 2a9f. trap is set, then a *note DivisionByZero: 2a9f.
exception is raised upon encountering the condition.

 -- Classe: decimal.Clamped

     Altered an exponent to fit representation constraints.

     Typically, clamping occurs when an exponent falls outside the
     context’s *note Emin: 12af. and *note Emax: 12ae. limits.  If
     possible, the exponent is reduced to fit by adding zeros to the
     coefficient.

 -- Classe: decimal.DecimalException

     Base class for other signals and a subclass of *note
     ArithmeticError: 26c8.

 -- Classe: decimal.DivisionByZero

     Signals the division of a non-infinite number by zero.

     Can occur with division, modulo division, or when raising a number
     to a negative power.  If this signal is not trapped, returns
     ‘Infinity’ or ‘-Infinity’ with the sign determined by the inputs to
     the calculation.

 -- Classe: decimal.Inexact

     Indicates that rounding occurred and the result is not exact.

     Signals when non-zero digits were discarded during rounding.  The
     rounded result is returned.  The signal flag or trap is used to
     detect when results are inexact.

 -- Classe: decimal.InvalidOperation

     An invalid operation was performed.

     Indicates that an operation was requested that does not make sense.
     If not trapped, returns ‘NaN’.  Possible causes include:

          Infinity - Infinity
          0 * Infinity
          Infinity / Infinity
          x % 0
          Infinity % x
          sqrt(-x) and x > 0
          0 ** 0
          x ** (non-integer)
          x ** Infinity

 -- Classe: decimal.Overflow

     Numerical overflow.

     Indicates the exponent is larger than *note Context.Emax: 12ae.
     after rounding has occurred.  If not trapped, the result depends on
     the rounding mode, either pulling inward to the largest
     representable finite number or rounding outward to ‘Infinity’.  In
     either case, *note Inexact: 2aa0. and *note Rounded: 2aa1. are also
     signaled.

 -- Classe: decimal.Rounded

     Rounding occurred though possibly no information was lost.

     Signaled whenever rounding discards digits; even if those digits
     are zero (such as rounding ‘5.00’ to ‘5.0’).  If not trapped,
     returns the result unchanged.  This signal is used to detect loss
     of significant digits.

 -- Classe: decimal.Subnormal

     Exponent was lower than *note Emin: 12af. prior to rounding.

     Occurs when an operation result is subnormal (the exponent is too
     small).  If not trapped, returns the result unchanged.

 -- Classe: decimal.Underflow

     Numerical underflow with result rounded to zero.

     Occurs when a subnormal result is pushed to zero by rounding.
     *note Inexact: 2aa0. and *note Subnormal: 2aa2. are also signaled.

 -- Classe: decimal.FloatOperation

     Enable stricter semantics for mixing floats and Decimals.

     If the signal is not trapped (default), mixing floats and Decimals
     is permitted in the *note Decimal: 1fe. constructor, *note
     create_decimal(): 12b1. and all comparison operators.  Both
     conversion and comparisons are exact.  Any occurrence of a mixed
     operation is silently recorded by setting *note FloatOperation:
     12a5. in the context flags.  Explicit conversions with *note
     from_float(): 140c. or *note create_decimal_from_float(): 2ae7. do
     not set the flag.

     Otherwise (the signal is trapped), only equality comparisons and
     explicit conversions are silent.  All other mixed operations raise
     *note FloatOperation: 12a5.

The following table summarizes the hierarchy of signals:

     exceptions.ArithmeticError(exceptions.Exception)
         DecimalException
             Clamped
             DivisionByZero(DecimalException, exceptions.ZeroDivisionError)
             Inexact
                 Overflow(Inexact, Rounded)
                 Underflow(Inexact, Rounded, Subnormal)
             InvalidOperation
             Rounded
             Subnormal
             FloatOperation(DecimalException, exceptions.TypeError)


File: python.info,  Node: Floating-point notes,  Next: Working with threads,  Prev: Signals,  Up: decimal — Decimal fixed-point and floating-point arithmetic

5.9.4.8 Floating-point notes
............................

* Menu:

* Mitigating round-off error with increased precision::
* Special values::


File: python.info,  Node: Mitigating round-off error with increased precision,  Next: Special values,  Up: Floating-point notes

5.9.4.9 Mitigating round-off error with increased precision
...........................................................

The use of decimal floating point eliminates decimal representation
error (making it possible to represent ‘0.1’ exactly); however, some
operations can still incur round-off error when non-zero digits exceed
the fixed precision.

The effects of round-off error can be amplified by the addition or
subtraction of nearly offsetting quantities resulting in loss of
significance.  Knuth provides two instructive examples where rounded
floating-point arithmetic with insufficient precision causes the
breakdown of the associative and distributive properties of addition:

     # Examples from Seminumerical Algorithms, Section 4.2.2.
     >>> from decimal import Decimal, getcontext
     >>> getcontext().prec = 8

     >>> u, v, w = Decimal(11111113), Decimal(-11111111), Decimal('7.51111111')
     >>> (u + v) + w
     Decimal('9.5111111')
     >>> u + (v + w)
     Decimal('10')

     >>> u, v, w = Decimal(20000), Decimal(-6), Decimal('6.0000003')
     >>> (u*v) + (u*w)
     Decimal('0.01')
     >>> u * (v+w)
     Decimal('0.0060000')

The *note decimal: 3a. module makes it possible to restore the
identities by expanding the precision sufficiently to avoid loss of
significance:

     >>> getcontext().prec = 20
     >>> u, v, w = Decimal(11111113), Decimal(-11111111), Decimal('7.51111111')
     >>> (u + v) + w
     Decimal('9.51111111')
     >>> u + (v + w)
     Decimal('9.51111111')
     >>>
     >>> u, v, w = Decimal(20000), Decimal(-6), Decimal('6.0000003')
     >>> (u*v) + (u*w)
     Decimal('0.0060000')
     >>> u * (v+w)
     Decimal('0.0060000')


File: python.info,  Node: Special values,  Prev: Mitigating round-off error with increased precision,  Up: Floating-point notes

5.9.4.10 Special values
.......................

The number system for the *note decimal: 3a. module provides special
values including ‘NaN’, ‘sNaN’, ‘-Infinity’, ‘Infinity’, and two zeros,
‘+0’ and ‘-0’.

Infinities can be constructed directly with: ‘Decimal('Infinity')’.
Also, they can arise from dividing by zero when the *note
DivisionByZero: 2a9f. signal is not trapped.  Likewise, when the *note
Overflow: 2aa3. signal is not trapped, infinity can result from rounding
beyond the limits of the largest representable number.

The infinities are signed (affine) and can be used in arithmetic
operations where they get treated as very large, indeterminate numbers.
For instance, adding a constant to infinity gives another infinite
result.

Some operations are indeterminate and return ‘NaN’, or if the *note
InvalidOperation: 12b0. signal is trapped, raise an exception.  For
example, ‘0/0’ returns ‘NaN’ which means «not a number».  This variety
of ‘NaN’ is quiet and, once created, will flow through other
computations always resulting in another ‘NaN’.  This behavior can be
useful for a series of computations that occasionally have missing
inputs — it allows the calculation to proceed while flagging specific
results as invalid.

A variant is ‘sNaN’ which signals rather than remaining quiet after
every operation.  This is a useful return value when an invalid result
needs to interrupt a calculation for special handling.

The behavior of Python’s comparison operators can be a little surprising
where a ‘NaN’ is involved.  A test for equality where one of the
operands is a quiet or signaling ‘NaN’ always returns *note False: d2d.
(even when doing ‘Decimal('NaN')==Decimal('NaN')’), while a test for
inequality always returns *note True: e09.  An attempt to compare two
Decimals using any of the ‘<’, ‘<=’, ‘>’ or ‘>=’ operators will raise
the *note InvalidOperation: 12b0. signal if either operand is a ‘NaN’,
and return *note False: d2d. if this signal is not trapped.  Note that
the General Decimal Arithmetic specification does not specify the
behavior of direct comparisons; these rules for comparisons involving a
‘NaN’ were taken from the IEEE 854 standard (see Table 3 in section
5.7).  To ensure strict standards-compliance, use the *note compare():
2aae. and *note compare_signal(): 2aaf. methods instead.

The signed zeros can result from calculations that underflow.  They keep
the sign that would have resulted if the calculation had been carried
out to greater precision.  Since their magnitude is zero, both positive
and negative zeros are treated as equal and their sign is informational.

In addition to the two signed zeros which are distinct yet equal, there
are various representations of zero with differing precisions yet
equivalent in value.  This takes a bit of getting used to.  For an eye
accustomed to normalized floating-point representations, it is not
immediately obvious that the following calculation returns a value equal
to zero:

     >>> 1 / Decimal('Infinity')
     Decimal('0E-1000026')


File: python.info,  Node: Working with threads,  Next: Recipes,  Prev: Floating-point notes,  Up: decimal — Decimal fixed-point and floating-point arithmetic

5.9.4.11 Working with threads
.............................

The *note getcontext(): 191f. function accesses a different *note
Context: 12b7. object for each thread.  Having separate thread contexts
means that threads may make changes (such as ‘getcontext().prec=10’)
without interfering with other threads.

Likewise, the *note setcontext(): 2aa7. function automatically assigns
its target to the current thread.

If *note setcontext(): 2aa7. has not been called before *note
getcontext(): 191f, then *note getcontext(): 191f. will automatically
create a new context for use in the current thread.  New context objects
have default values set from the *note decimal.DefaultContext: 12ab.
object.

The *note sys.flags.thread_inherit_context: 175. flag affects the
context for new threads.  If the flag is false, new threads will start
with an empty context.  In this case, *note getcontext(): 191f. will
create a new context object when called and use the default values from
'DefaultContext'.  If the flag is true, new threads will start with a
copy of context from the caller of *note threading.Thread.start(): 178.

To control the defaults so that each thread will use the same values
throughout the application, directly modify the 'DefaultContext' object.
This should be done 'before' any threads are started so that there won’t
be a race condition between threads calling *note getcontext(): 191f.
For example:

     # Set applicationwide defaults for all threads about to be launched
     DefaultContext.prec = 12
     DefaultContext.rounding = ROUND_DOWN
     DefaultContext.traps = ExtendedContext.traps.copy()
     DefaultContext.traps[InvalidOperation] = 1
     setcontext(DefaultContext)

     # Afterwards, the threads can be started
     t1.start()
     t2.start()
     t3.start()
      . . .


File: python.info,  Node: Recipes,  Next: Decimal FAQ,  Prev: Working with threads,  Up: decimal — Decimal fixed-point and floating-point arithmetic

5.9.4.12 Recipes
................

Here are a few recipes that serve as utility functions and that
demonstrate ways to work with the *note Decimal: 1fe. class:

     def moneyfmt(value, places=2, curr='', sep=',', dp='.',
                  pos='', neg='-', trailneg=''):
         """Convert Decimal to a money formatted string.

         places:  required number of places after the decimal point
         curr:    optional currency symbol before the sign (may be blank)
         sep:     optional grouping separator (comma, period, space, or blank)
         dp:      decimal point indicator (comma or period)
                  only specify as blank when places is zero
         pos:     optional sign for positive numbers: '+', space or blank
         neg:     optional sign for negative numbers: '-', '(', space or blank
         trailneg:optional trailing minus indicator:  '-', ')', space or blank

         >>> d = Decimal('-1234567.8901')
         >>> moneyfmt(d, curr='$')
         '-$1,234,567.89'
         >>> moneyfmt(d, places=0, sep='.', dp='', neg='', trailneg='-')
         '1.234.568-'
         >>> moneyfmt(d, curr='$', neg='(', trailneg=')')
         '($1,234,567.89)'
         >>> moneyfmt(Decimal(123456789), sep=' ')
         '123 456 789.00'
         >>> moneyfmt(Decimal('-0.02'), neg='<', trailneg='>')
         '<0.02>'

         """
         q = Decimal(10) ** -places      # 2 places --> '0.01'
         sign, digits, exp = value.quantize(q).as_tuple()
         result = []
         digits = list(map(str, digits))
         build, next = result.append, digits.pop
         if sign:
             build(trailneg)
         for i in range(places):
             build(next() if digits else '0')
         if places:
             build(dp)
         if not digits:
             build('0')
         i = 0
         while digits:
             build(next())
             i += 1
             if i == 3 and digits:
                 i = 0
                 build(sep)
         build(curr)
         build(neg if sign else pos)
         return ''.join(reversed(result))

     def pi():
         """Compute Pi to the current precision.

         >>> print(pi())
         3.141592653589793238462643383

         """
         getcontext().prec += 2  # extra digits for intermediate steps
         three = Decimal(3)      # substitute "three=3.0" for regular floats
         lasts, t, s, n, na, d, da = 0, three, 3, 1, 0, 0, 24
         while s != lasts:
             lasts = s
             n, na = n+na, na+8
             d, da = d+da, da+32
             t = (t * n) / d
             s += t
         getcontext().prec -= 2
         return +s               # unary plus applies the new precision

     def exp(x):
         """Return e raised to the power of x.  Result type matches input type.

         >>> print(exp(Decimal(1)))
         2.718281828459045235360287471
         >>> print(exp(Decimal(2)))
         7.389056098930650227230427461
         >>> print(exp(2.0))
         7.38905609893
         >>> print(exp(2+0j))
         (7.38905609893+0j)

         """
         getcontext().prec += 2
         i, lasts, s, fact, num = 0, 0, 1, 1, 1
         while s != lasts:
             lasts = s
             i += 1
             fact *= i
             num *= x
             s += num / fact
         getcontext().prec -= 2
         return +s

     def cos(x):
         """Return the cosine of x as measured in radians.

         The Taylor series approximation works best for a small value of x.
         For larger values, first compute x = x % (2 * pi).

         >>> print(cos(Decimal('0.5')))
         0.8775825618903727161162815826
         >>> print(cos(0.5))
         0.87758256189
         >>> print(cos(0.5+0j))
         (0.87758256189+0j)

         """
         getcontext().prec += 2
         i, lasts, s, fact, num, sign = 0, 0, 1, 1, 1, 1
         while s != lasts:
             lasts = s
             i += 2
             fact *= i * (i-1)
             num *= x * x
             sign *= -1
             s += num / fact * sign
         getcontext().prec -= 2
         return +s

     def sin(x):
         """Return the sine of x as measured in radians.

         The Taylor series approximation works best for a small value of x.
         For larger values, first compute x = x % (2 * pi).

         >>> print(sin(Decimal('0.5')))
         0.4794255386042030002732879352
         >>> print(sin(0.5))
         0.479425538604
         >>> print(sin(0.5+0j))
         (0.479425538604+0j)

         """
         getcontext().prec += 2
         i, lasts, s, fact, num, sign = 1, 0, x, 1, x, 1
         while s != lasts:
             lasts = s
             i += 2
             fact *= i * (i-1)
             num *= x * x
             sign *= -1
             s += num / fact * sign
         getcontext().prec -= 2
         return +s


File: python.info,  Node: Decimal FAQ,  Prev: Recipes,  Up: decimal — Decimal fixed-point and floating-point arithmetic

5.9.4.13 Decimal FAQ
....................

Q: It is cumbersome to type ‘decimal.Decimal('1234.5')’.  Is there a way
to minimize typing when using the interactive interpreter?

A: Some users abbreviate the constructor to just a single letter:

     >>> D = decimal.Decimal
     >>> D('1.23') + D('3.45')
     Decimal('4.68')

Q: In a fixed-point application with two decimal places, some inputs
have many places and need to be rounded.  Others are not supposed to
have excess digits and need to be validated.  What methods should be
used?

A: The *note quantize(): 12b8. method rounds to a fixed number of
decimal places.  If the *note Inexact: 2aa0. trap is set, it is also
useful for validation:

     >>> TWOPLACES = Decimal(10) ** -2       # same as Decimal('0.01')

     >>> # Round to two places
     >>> Decimal('3.214').quantize(TWOPLACES)
     Decimal('3.21')

     >>> # Validate that a number does not exceed two places
     >>> Decimal('3.21').quantize(TWOPLACES, context=Context(traps=[Inexact]))
     Decimal('3.21')

     >>> Decimal('3.214').quantize(TWOPLACES, context=Context(traps=[Inexact]))
     Traceback (most recent call last):
        ...
     Inexact: None

Q: Once I have valid two place inputs, how do I maintain that invariant
throughout an application?

A: Some operations like addition, subtraction, and multiplication by an
integer will automatically preserve fixed point.  Others operations,
like division and non-integer multiplication, will change the number of
decimal places and need to be followed-up with a *note quantize(): 12b8.
step:

     >>> a = Decimal('102.72')           # Initial fixed-point values
     >>> b = Decimal('3.17')
     >>> a + b                           # Addition preserves fixed-point
     Decimal('105.89')
     >>> a - b
     Decimal('99.55')
     >>> a * 42                          # So does integer multiplication
     Decimal('4314.24')
     >>> (a * b).quantize(TWOPLACES)     # Must quantize non-integer multiplication
     Decimal('325.62')
     >>> (b / a).quantize(TWOPLACES)     # And quantize division
     Decimal('0.03')

In developing fixed-point applications, it is convenient to define
functions to handle the *note quantize(): 12b8. step:

     >>> def mul(x, y, fp=TWOPLACES):
     ...     return (x * y).quantize(fp)
     ...
     >>> def div(x, y, fp=TWOPLACES):
     ...     return (x / y).quantize(fp)

     >>> mul(a, b)                       # Automatically preserve fixed-point
     Decimal('325.62')
     >>> div(b, a)
     Decimal('0.03')

Q: There are many ways to express the same value.  The numbers ‘200’,
‘200.000’, ‘2E2’, and ‘.02E+4’ all have the same value at various
precisions.  Is there a way to transform them to a single recognizable
canonical value?

A: The *note normalize(): 2acf. method maps all equivalent values to a
single representative:

     >>> values = map(Decimal, '200 200.000 2E2 .02E+4'.split())
     >>> [v.normalize() for v in values]
     [Decimal('2E+2'), Decimal('2E+2'), Decimal('2E+2'), Decimal('2E+2')]

Q: When does rounding occur in a computation?

A: It occurs 'after' the computation.  The philosophy of the decimal
specification is that numbers are considered exact and are created
independent of the current context.  They can even have greater
precision than current context.  Computations process with those exact
inputs and then rounding (or other context operations) is applied to the
'result' of the computation:

     >>> getcontext().prec = 5
     >>> pi = Decimal('3.1415926535')   # More than 5 digits
     >>> pi                             # All digits are retained
     Decimal('3.1415926535')
     >>> pi + 0                         # Rounded after an addition
     Decimal('3.1416')
     >>> pi - Decimal('0.00005')        # Subtract unrounded numbers, then round
     Decimal('3.1415')
     >>> pi + 0 - Decimal('0.00005').   # Intermediate values are rounded
     Decimal('3.1416')

Q: Some decimal values always print with exponential notation.  Is there
a way to get a non-exponential representation?

A: For some values, exponential notation is the only way to express the
number of significant places in the coefficient.  For example,
expressing ‘5.0E+3’ as ‘5000’ keeps the value constant but cannot show
the original’s two-place significance.

If an application does not care about tracking significance, it is easy
to remove the exponent and trailing zeroes, losing significance, but
keeping the value unchanged:

     >>> def remove_exponent(d):
     ...     return d.quantize(Decimal(1)) if d == d.to_integral() else d.normalize()

     >>> remove_exponent(Decimal('5E+3'))
     Decimal('5000')

Q: Is there a way to convert a regular float to a *note Decimal: 1fe.?

A: Yes, any binary floating-point number can be exactly expressed as a
Decimal though an exact conversion may take more precision than
intuition would suggest:

     >>> Decimal(math.pi)
     Decimal('3.141592653589793115997963468544185161590576171875')

Q: Within a complex calculation, how can I make sure that I haven’t
gotten a spurious result because of insufficient precision or rounding
anomalies.

A: The decimal module makes it easy to test results.  A best practice is
to re-run calculations using greater precision and with various rounding
modes.  Widely differing results indicate insufficient precision,
rounding mode issues, ill-conditioned inputs, or a numerically unstable
algorithm.

Q: I noticed that context precision is applied to the results of
operations but not to the inputs.  Is there anything to watch out for
when mixing values of different precisions?

A: Yes.  The principle is that all values are considered to be exact and
so is the arithmetic on those values.  Only the results are rounded.
The advantage for inputs is that «what you type is what you get».  A
disadvantage is that the results can look odd if you forget that the
inputs haven’t been rounded:

     >>> getcontext().prec = 3
     >>> Decimal('3.104') + Decimal('2.104')
     Decimal('5.21')
     >>> Decimal('3.104') + Decimal('0.000') + Decimal('2.104')
     Decimal('5.20')

The solution is either to increase precision or to force rounding of
inputs using the unary plus operation:

     >>> getcontext().prec = 3
     >>> +Decimal('1.23456789')      # unary plus triggers rounding
     Decimal('1.23')

Alternatively, inputs can be rounded upon creation using the *note
Context.create_decimal(): 12b1. method:

     >>> Context(prec=5, rounding=ROUND_DOWN).create_decimal('1.2345678')
     Decimal('1.2345')

Q: Is the CPython implementation fast for large numbers?

A: Yes.  In the CPython and PyPy3 implementations, the C/CFFI versions
of the decimal module integrate the high speed libmpdec(1) library for
arbitrary precision correctly rounded decimal floating-point arithmetic
(2).  ‘libmpdec’ uses Karatsuba multiplication(3) for medium-sized
numbers and the Number Theoretic Transform(4) for very large numbers.

The context must be adapted for exact arbitrary precision arithmetic.
*note Emin: 12af. and *note Emax: 12ae. should always be set to the
maximum values, *note clamp: 13a6. should always be 0 (the default).
Setting *note prec: 2ae0. requires some care.

The easiest approach for trying out bignum arithmetic is to use the
maximum value for *note prec: 2ae0. as well (5):

     >>> setcontext(Context(prec=MAX_PREC, Emax=MAX_EMAX, Emin=MIN_EMIN))
     >>> x = Decimal(2) ** 256
     >>> x / 128
     Decimal('904625697166532776746648320380374280103671755200316906558262375061821325312')

For inexact results, *note MAX_PREC: 12a8. is far too large on 64-bit
platforms and the available memory will be insufficient:

     >>> Decimal(1) / 3
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     MemoryError

On systems with overallocation (e.g.  Linux), a more sophisticated
approach is to adjust *note prec: 2ae0. to the amount of available RAM.
Suppose that you have 8GB of RAM and expect 10 simultaneous operands
using a maximum of 500MB each:

     >>> import sys
     >>>
     >>> # Maximum number of digits for a single operand using 500MB in 8-byte words
     >>> # with 19 digits per word (4-byte and 9 digits for the 32-bit build):
     >>> maxdigits = 19 * ((500 * 1024**2) // 8)
     >>>
     >>> # Check that this works:
     >>> c = Context(prec=maxdigits, Emax=MAX_EMAX, Emin=MIN_EMIN)
     >>> c.traps[Inexact] = True
     >>> setcontext(c)
     >>>
     >>> # Fill the available precision with nines:
     >>> x = Decimal(0).logical_invert() * 9
     >>> sys.getsizeof(x)
     524288112
     >>> x + 2
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
       decimal.Inexact: [<class 'decimal.Inexact'>]

In general (and especially on systems without overallocation), it is
recommended to estimate even tighter bounds and set the *note Inexact:
2aa0. trap if all calculations are expected to be exact.

   ---------- Footnotes ----------

   (1) https://www.bytereef.org/mpdecimal/doc/libmpdec/index.html

   (2) 
Added in version 3.3.

   (3) https://en.wikipedia.org/wiki/Karatsuba_algorithm

   (4) 
https://en.wikipedia.org/wiki/Discrete_Fourier_transform_(general)#Number-theoretic_transform

   (5) 
Cambiato nella versione 3.9: This approach now works for all exact
results except for non-integer powers.


File: python.info,  Node: fractions — Rational numbers,  Next: random — Generate pseudo-random numbers,  Prev: decimal — Decimal fixed-point and floating-point arithmetic,  Up: Numeric and Mathematical Modules

5.9.5 ‘fractions’ — Rational numbers
------------------------------------

'Source code:' Lib/fractions.py(1)

__________________________________________________________________

The *note fractions: 61. module provides support for rational number
arithmetic.

A Fraction instance can be constructed from a pair of rational numbers,
from a single number, or from a string.

 -- Classe: fractions.Fraction (numerator=0, denominator=1)

 -- Classe: fractions.Fraction (number)

 -- Classe: fractions.Fraction (string)

     The first version requires that 'numerator' and 'denominator' are
     instances of *note numbers.Rational: 14c6. and returns a new *note
     Fraction: 213. instance with a value equal to
     ‘numerator/denominator’.  If 'denominator' is zero, it raises a
     *note ZeroDivisionError: b41.

     The second version requires that 'number' is an instance of *note
     numbers.Rational: 14c6. or has the ‘as_integer_ratio()’ method
     (this includes *note float: 196. and *note decimal.Decimal: 1fe.).
     It returns a *note Fraction: 213. instance with exactly the same
     value.  Assumed, that the ‘as_integer_ratio()’ method returns a
     pair of coprime integers and last one is positive.  Note that due
     to the usual issues with binary point (see *note Floating-Point
     Arithmetic; Issues and Limitations: 20ea.), the argument to
     ‘Fraction(1.1)’ is not exactly equal to 11/10, and so
     ‘Fraction(1.1)’ does 'not' return ‘Fraction(11, 10)’ as one might
     expect.  (But see the documentation for the *note
     limit_denominator(): 2b34. method below.)

     The last version of the constructor expects a string.  The usual
     form for this instance is:

          [sign] numerator ['/' denominator]

     where the optional ‘sign’ may be either “+” or “-” and ‘numerator’
     and ‘denominator’ (if present) are strings of decimal digits
     (underscores may be used to delimit digits as with integral
     literals in code).  In addition, any string that represents a
     finite value and is accepted by the *note float: 196. constructor
     is also accepted by the *note Fraction: 213. constructor.  In
     either form the input string may also have leading and/or trailing
     whitespace.  Here are some examples:

          >>> from fractions import Fraction
          >>> Fraction(16, -10)
          Fraction(-8, 5)
          >>> Fraction(123)
          Fraction(123, 1)
          >>> Fraction()
          Fraction(0, 1)
          >>> Fraction('3/7')
          Fraction(3, 7)
          >>> Fraction(' -3/7 ')
          Fraction(-3, 7)
          >>> Fraction('1.414213 \t\n')
          Fraction(1414213, 1000000)
          >>> Fraction('-.125')
          Fraction(-1, 8)
          >>> Fraction('7e-6')
          Fraction(7, 1000000)
          >>> Fraction(2.25)
          Fraction(9, 4)
          >>> Fraction(1.1)
          Fraction(2476979795053773, 2251799813685248)
          >>> from decimal import Decimal
          >>> Fraction(Decimal('1.1'))
          Fraction(11, 10)

     The *note Fraction: 213. class inherits from the abstract base
     class *note numbers.Rational: 14c6, and implements all of the
     methods and operations from that class.  *note Fraction: 213.
     instances are *note hashable: 825, and should be treated as
     immutable.  In addition, *note Fraction: 213. has the following
     properties and methods:

     Cambiato nella versione 3.2: The *note Fraction: 213. constructor
     now accepts *note float: 196. and *note decimal.Decimal: 1fe.
     instances.

     Cambiato nella versione 3.9: The *note math.gcd(): b0e. function is
     now used to normalize the 'numerator' and 'denominator'.  *note
     math.gcd(): b0e. always returns an *note int: 19b. type.
     Previously, the GCD type depended on 'numerator' and 'denominator'.

     Cambiato nella versione 3.11: Underscores are now permitted when
     creating a *note Fraction: 213. instance from a string, following
     PEP 515(2) rules.

     Cambiato nella versione 3.11: *note Fraction: 213. implements
     ‘__int__’ now to satisfy ‘typing.SupportsInt’ instance checks.

     Cambiato nella versione 3.12: Space is allowed around the slash for
     string inputs: ‘Fraction('2 / 3')’.

     Cambiato nella versione 3.12: *note Fraction: 213. instances now
     support float-style formatting, with presentation types ‘"e"’,
     ‘"E"’, ‘"f"’, ‘"F"’, ‘"g"’, ‘"G"’ and ‘"%""’.

     Cambiato nella versione 3.13: Formatting of *note Fraction: 213.
     instances without a presentation type now supports fill, alignment,
     sign handling, minimum width and grouping.

     Cambiato nella versione 3.14: The *note Fraction: 213. constructor
     now accepts any objects with the ‘as_integer_ratio()’ method.

      -- Attributo: numerator

          Numerator of the Fraction in lowest term.

      -- Attributo: denominator

          Denominator of the Fraction in lowest terms.  Guaranteed to be
          positive.

      -- Metodo: as_integer_ratio ()

          Return a tuple of two integers, whose ratio is equal to the
          original Fraction.  The ratio is in lowest terms and has a
          positive denominator.

          Added in version 3.8.

      -- Metodo: is_integer ()

          Return ‘True’ if the Fraction is an integer.

          Added in version 3.12.

      -- Metodo: classmethod from_float (f)

          Alternative constructor which only accepts instances of *note
          float: 196. or *note numbers.Integral: 23ed.  Beware that
          ‘Fraction.from_float(0.3)’ is not the same value as
          ‘Fraction(3, 10)’.

               Nota: From Python 3.2 onwards, you can also construct a
               *note Fraction: 213. instance directly from a *note
               float: 196.

      -- Metodo: classmethod from_decimal (dec)

          Alternative constructor which only accepts instances of *note
          decimal.Decimal: 1fe. or *note numbers.Integral: 23ed.

               Nota: From Python 3.2 onwards, you can also construct a
               *note Fraction: 213. instance directly from a *note
               decimal.Decimal: 1fe. instance.

      -- Metodo: classmethod from_number (number)

          Alternative constructor which only accepts instances of *note
          numbers.Integral: 23ed, *note numbers.Rational: 14c6, *note
          float: 196. or *note decimal.Decimal: 1fe, and objects with
          the ‘as_integer_ratio()’ method, but not strings.

          Added in version 3.14.

      -- Metodo: limit_denominator (max_denominator=1000000)

          Finds and returns the closest *note Fraction: 213. to ‘self’
          that has denominator at most max_denominator.  This method is
          useful for finding rational approximations to a given
          floating-point number:

               >>> from fractions import Fraction
               >>> Fraction('3.1415926535897932').limit_denominator(1000)
               Fraction(355, 113)

          or for recovering a rational number that’s represented as a
          float:

               >>> from math import pi, cos
               >>> Fraction(cos(pi/3))
               Fraction(4503599627370497, 9007199254740992)
               >>> Fraction(cos(pi/3)).limit_denominator()
               Fraction(1, 2)
               >>> Fraction(1.1).limit_denominator()
               Fraction(11, 10)

      -- Metodo: __floor__ ()

          Returns the greatest *note int: 19b. ‘<= self’.  This method
          can also be accessed through the *note math.floor(): 15c5.
          function:

               >>> from math import floor
               >>> floor(Fraction(355, 113))
               3

      -- Metodo: __ceil__ ()

          Returns the least *note int: 19b. ‘>= self’.  This method can
          also be accessed through the *note math.ceil(): 15c6.
          function.

      -- Metodo: __round__ ()

      -- Metodo: __round__ (ndigits)

          The first version returns the nearest *note int: 19b. to
          ‘self’, rounding half to even.  The second version rounds
          ‘self’ to the nearest multiple of ‘Fraction(1, 10**ndigits)’
          (logically, if ‘ndigits’ is negative), again rounding half
          toward even.  This method can also be accessed through the
          *note round(): 14e2. function.

      -- Metodo: __format__ (format_spec, /)

          Provides support for formatting of *note Fraction: 213.
          instances via the *note str.format(): 834. method, the *note
          format(): 199. built-in function, or *note Formatted string
          literals: 19a.

          If the ‘format_spec’ format specification string does not end
          with one of the presentation types ‘'e'’, ‘'E'’, ‘'f'’, ‘'F'’,
          ‘'g'’, ‘'G'’ or ‘'%'’ then formatting follows the general
          rules for fill, alignment, sign handling, minimum width, and
          grouping as described in the *note format specification
          mini-language: 4fa.  The «alternate form» flag ‘'#'’ is
          supported: if present, it forces the output string to always
          include an explicit denominator, even when the value being
          formatted is an exact integer.  The zero-fill flag ‘'0'’ is
          not supported.

          If the ‘format_spec’ format specification string ends with one
          of the presentation types ‘'e'’, ‘'E'’, ‘'f'’, ‘'F'’, ‘'g'’,
          ‘'G'’ or ‘'%'’ then formatting follows the rules outlined for
          the *note float: 196. type in the *note Format Specification
          Mini-Language: 4fa. section.

          Here are some examples:

               >>> from fractions import Fraction
               >>> format(Fraction(103993, 33102), '_')
               '103_993/33_102'
               >>> format(Fraction(1, 7), '.^+10')
               '...+1/7...'
               >>> format(Fraction(3, 1), '')
               '3'
               >>> format(Fraction(3, 1), '#')
               '3/1'
               >>> format(Fraction(1, 7), '.40g')
               '0.1428571428571428571428571428571428571429'
               >>> format(Fraction('1234567.855'), '_.2f')
               '1_234_567.86'
               >>> f"{Fraction(355, 113):*>20.6e}"
               '********3.141593e+00'
               >>> old_price, new_price = 499, 672
               >>> "{:.2%} price increase".format(Fraction(new_price, old_price) - 1)
               '34.67% price increase'

Vedi anche
..........

Module *note numbers: a2.

     The abstract base classes making up the numeric tower.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/fractions.py

   (2) https://peps.python.org/pep-0515/


File: python.info,  Node: random — Generate pseudo-random numbers,  Next: statistics — Mathematical statistics functions,  Prev: fractions — Rational numbers,  Up: Numeric and Mathematical Modules

5.9.6 ‘random’ — Generate pseudo-random numbers
-----------------------------------------------

'Source code:' Lib/random.py(1)

__________________________________________________________________

This module implements pseudo-random number generators for various
distributions.

For integers, there is uniform selection from a range.  For sequences,
there is uniform selection of a random element, a function to generate a
random permutation of a list in-place, and a function for random
sampling without replacement.

On the real line, there are functions to compute uniform, normal
(Gaussian), lognormal, negative exponential, gamma, and beta
distributions.  For generating distributions of angles, the von Mises
distribution is available.

Almost all module functions depend on the basic function *note random():
950, which generates a random float uniformly in the half-open range
‘0.0 <= X < 1.0’.  Python uses the Mersenne Twister as the core
generator.  It produces 53-bit precision floats and has a period of
2**19937-1.  The underlying implementation in C is both fast and
threadsafe.  The Mersenne Twister is one of the most extensively tested
random number generators in existence.  However, being completely
deterministic, it is not suitable for all purposes, and is completely
unsuitable for cryptographic purposes.

The functions supplied by this module are actually bound methods of a
hidden instance of the *note random.Random: 1c44. class.  You can
instantiate your own instances of *note Random: 1c44. to get generators
that don’t share state.

Class *note Random: 1c44. can also be subclassed if you want to use a
different basic generator of your own devising: see the documentation on
that class for more details.

The *note random: bd. module also provides the *note SystemRandom: 2b3d.
class which uses the system function *note os.urandom(): 747. to
generate random numbers from sources provided by the operating system.

     Avvertimento: The pseudo-random generators of this module should
     not be used for security purposes.  For security or cryptographic
     uses, see the *note secrets: c5. module.

Vedi anche
..........

M. Matsumoto and T. Nishimura, «Mersenne Twister: A 623-dimensionally
equidistributed uniform pseudorandom number generator», ACM Transactions
on Modeling and Computer Simulation Vol.  8, No.  1, January pp.3–30
1998.

Complementary-Multiply-with-Carry recipe(2) for a compatible alternative
random number generator with a long period and comparatively simple
update operations.

     Nota: The global random number generator and instances of *note
     Random: 1c44. are thread-safe.  However, in the free-threaded
     build, concurrent calls to the global generator or to the same
     instance of *note Random: 1c44. may encounter contention and poor
     performance.  Consider using separate instances of *note Random:
     1c44. per thread instead.

* Menu:

* Bookkeeping functions::
* Functions for bytes::
* Functions for integers::
* Functions for sequences::
* Discrete distributions::
* Real-valued distributions::
* Alternative Generator::
* Notes on Reproducibility::
* Examples: Examples<4>.
* Recipes: Recipes<2>.
* Command-line usage: Command-line usage<2>.
* Command-line example::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/random.py

   (2) 
https://code.activestate.com/recipes/576707-long-period-random-number-generator/


File: python.info,  Node: Bookkeeping functions,  Next: Functions for bytes,  Up: random — Generate pseudo-random numbers

5.9.6.1 Bookkeeping functions
.............................

 -- Funzione: random.seed (a=None, version=2)

     Initialize the random number generator.

     If 'a' is omitted or ‘None’, the current system time is used.  If
     randomness sources are provided by the operating system, they are
     used instead of the system time (see the *note os.urandom(): 747.
     function for details on availability).

     If 'a' is an int, its absolute value is used directly.

     With version 2 (the default), a *note str: 169, *note bytes: 192,
     or *note bytearray: 344. object gets converted to an *note int:
     19b. and all of its bits are used.

     With version 1 (provided for reproducing random sequences from
     older versions of Python), the algorithm for *note str: 169. and
     *note bytes: 192. generates a narrower range of seeds.

     Cambiato nella versione 3.2: Moved to the version 2 scheme which
     uses all of the bits in a string seed.

     Cambiato nella versione 3.11: The 'seed' must be one of the
     following types: ‘None’, *note int: 19b, *note float: 196, *note
     str: 169, *note bytes: 192, or *note bytearray: 344.

 -- Funzione: random.getstate ()

     Return an object capturing the current internal state of the
     generator.  This object can be passed to *note setstate(): 2b40. to
     restore the state.

 -- Funzione: random.setstate (state)

     'state' should have been obtained from a previous call to *note
     getstate(): 2b3f, and *note setstate(): 2b40. restores the internal
     state of the generator to what it was at the time *note getstate():
     2b3f. was called.


File: python.info,  Node: Functions for bytes,  Next: Functions for integers,  Prev: Bookkeeping functions,  Up: random — Generate pseudo-random numbers

5.9.6.2 Functions for bytes
...........................

 -- Funzione: random.randbytes (n)

     Generate 'n' random bytes.

     This method should not be used for generating security tokens.  Use
     *note secrets.token_bytes(): 2b42. instead.

     Added in version 3.9.


File: python.info,  Node: Functions for integers,  Next: Functions for sequences,  Prev: Functions for bytes,  Up: random — Generate pseudo-random numbers

5.9.6.3 Functions for integers
..............................

 -- Funzione: random.randrange (stop)

 -- Funzione: random.randrange (start, stop[, step])

     Return a randomly selected element from ‘range(start, stop, step)’.

     This is roughly equivalent to ‘choice(range(start, stop, step))’
     but supports arbitrarily large ranges and is optimized for common
     cases.

     The positional argument pattern matches the *note range(): b3f.
     function.

     Keyword arguments should not be used because they can be
     interpreted in unexpected ways.  For example ‘randrange(start=100)’
     is interpreted as ‘randrange(0, 100, 1)’.

     Cambiato nella versione 3.2: *note randrange(): a6d. is more
     sophisticated about producing equally distributed values.  Formerly
     it used a style like ‘int(random()*n)’ which could produce slightly
     uneven distributions.

     Cambiato nella versione 3.12: Automatic conversion of non-integer
     types is no longer supported.  Calls such as ‘randrange(10.0)’ and
     ‘randrange(Fraction(10, 1))’ now raise a *note TypeError: 198.

 -- Funzione: random.randint (a, b)

     Return a random integer 'N' such that ‘a <= N <= b’.  Alias for
     ‘randrange(a, b+1)’.

 -- Funzione: random.getrandbits (k)

     Returns a non-negative Python integer with 'k' random bits.  This
     method is supplied with the Mersenne Twister generator and some
     other generators may also provide it as an optional part of the
     API.  When available, *note getrandbits(): 120f. enables *note
     randrange(): a6d. to handle arbitrarily large ranges.

     Cambiato nella versione 3.9: This method now accepts zero for 'k'.


File: python.info,  Node: Functions for sequences,  Next: Discrete distributions,  Prev: Functions for integers,  Up: random — Generate pseudo-random numbers

5.9.6.4 Functions for sequences
...............................

 -- Funzione: random.choice (seq)

     Return a random element from the non-empty sequence 'seq'.  If
     'seq' is empty, raises *note IndexError: 173c.

 -- Funzione: random.choices (population, weights=None, *,
          cum_weights=None, k=1)

     Return a 'k' sized list of elements chosen from the 'population'
     with replacement.  If the 'population' is empty, raises *note
     IndexError: 173c.

     If a 'weights' sequence is specified, selections are made according
     to the relative weights.  Alternatively, if a 'cum_weights'
     sequence is given, the selections are made according to the
     cumulative weights (perhaps computed using *note
     itertools.accumulate(): bf2.).  For example, the relative weights
     ‘[10, 5, 30, 5]’ are equivalent to the cumulative weights ‘[10, 15,
     45, 50]’.  Internally, the relative weights are converted to
     cumulative weights before making selections, so supplying the
     cumulative weights saves work.

     If neither 'weights' nor 'cum_weights' are specified, selections
     are made with equal probability.  If a weights sequence is
     supplied, it must be the same length as the 'population' sequence.
     It is a *note TypeError: 198. to specify both 'weights' and
     'cum_weights'.

     The 'weights' or 'cum_weights' can use any numeric type that
     interoperates with the *note float: 196. values returned by *note
     random(): bd. (that includes integers, floats, and fractions but
     excludes decimals).  Weights are assumed to be non-negative and
     finite.  A *note ValueError: 2ec. is raised if all weights are
     zero.

     For a given seed, the *note choices(): ec3. function with equal
     weighting typically produces a different sequence than repeated
     calls to *note choice(): 1438.  The algorithm used by *note
     choices(): ec3. uses floating-point arithmetic for internal
     consistency and speed.  The algorithm used by *note choice(): 1438.
     defaults to integer arithmetic with repeated selections to avoid
     small biases from round-off error.

     Added in version 3.6.

     Cambiato nella versione 3.9: Raises a *note ValueError: 2ec. if all
     weights are zero.

 -- Funzione: random.shuffle (x)

     Shuffle the sequence 'x' in place.

     To shuffle an immutable sequence and return a new shuffled list,
     use ‘sample(x, k=len(x))’ instead.

     Note that even for small ‘len(x)’, the total number of permutations
     of 'x' can quickly grow larger than the period of most random
     number generators.  This implies that most permutations of a long
     sequence can never be generated.  For example, a sequence of length
     2080 is the largest that can fit within the period of the Mersenne
     Twister random number generator.

     Cambiato nella versione 3.11: Removed the optional parameter
     'random'.

 -- Funzione: random.sample (population, k, *, counts=None)

     Return a 'k' length list of unique elements chosen from the
     population sequence.  Used for random sampling without replacement.

     Returns a new list containing elements from the population while
     leaving the original population unchanged.  The resulting list is
     in selection order so that all sub-slices will also be valid random
     samples.  This allows raffle winners (the sample) to be partitioned
     into grand prize and second place winners (the subslices).

     Members of the population need not be *note hashable: 825. or
     unique.  If the population contains repeats, then each occurrence
     is a possible selection in the sample.

     Repeated elements can be specified one at a time or with the
     optional keyword-only 'counts' parameter.  For example,
     ‘sample(['red', 'blue'], counts=[4, 2], k=5)’ is equivalent to
     ‘sample(['red', 'red', 'red', 'red', 'blue', 'blue'], k=5)’.

     To choose a sample from a range of integers, use a *note range():
     b3f. object as an argument.  This is especially fast and space
     efficient for sampling from a large population:
     ‘sample(range(10000000), k=60)’.

     If the sample size is larger than the population size, a *note
     ValueError: 2ec. is raised.

     Cambiato nella versione 3.9: Added the 'counts' parameter.

     Cambiato nella versione 3.11: The 'population' must be a sequence.
     Automatic conversion of sets to lists is no longer supported.


File: python.info,  Node: Discrete distributions,  Next: Real-valued distributions,  Prev: Functions for sequences,  Up: random — Generate pseudo-random numbers

5.9.6.5 Discrete distributions
..............................

The following function generates a discrete distribution.

 -- Funzione: random.binomialvariate (n=1, p=0.5)

     Binomial distribution(1).  Return the number of successes for 'n'
     independent trials with the probability of success in each trial
     being 'p':

     Mathematically equivalent to:

          sum(random() < p for i in range(n))

     The number of trials 'n' should be a non-negative integer.  The
     probability of success 'p' should be between ‘0.0 <= p <= 1.0’.
     The result is an integer in the range ‘0 <= X <= n’.

     Added in version 3.12.

   ---------- Footnotes ----------

   (1) https://mathworld.wolfram.com/BinomialDistribution.html


File: python.info,  Node: Real-valued distributions,  Next: Alternative Generator,  Prev: Discrete distributions,  Up: random — Generate pseudo-random numbers

5.9.6.6 Real-valued distributions
.................................

The following functions generate specific real-valued distributions.
Function parameters are named after the corresponding variables in the
distribution’s equation, as used in common mathematical practice; most
of these equations can be found in any statistics text.

 -- Funzione: random.random ()

     Return the next random floating-point number in the range ‘0.0 <= X
     < 1.0’

 -- Funzione: random.uniform (a, b)

     Return a random floating-point number 'N' such that ‘a <= N <= b’
     for ‘a <= b’ and ‘b <= N <= a’ for ‘b < a’.

     The end-point value ‘b’ may or may not be included in the range
     depending on floating-point rounding in the expression ‘a + (b-a) *
     random()’.

 -- Funzione: random.triangular (low, high, mode)

     Return a random floating-point number 'N' such that ‘low <= N <=
     high’ and with the specified 'mode' between those bounds.  The
     'low' and 'high' bounds default to zero and one.  The 'mode'
     argument defaults to the midpoint between the bounds, giving a
     symmetric distribution.

 -- Funzione: random.betavariate (alpha, beta)

     Beta distribution.  Conditions on the parameters are ‘alpha > 0’
     and ‘beta > 0’.  Returned values range between 0 and 1.

 -- Funzione: random.expovariate (lambd=1.0)

     Exponential distribution.  'lambd' is 1.0 divided by the desired
     mean.  It should be nonzero.  (The parameter would be called
     «lambda», but that is a reserved word in Python.)  Returned values
     range from 0 to positive infinity if 'lambd' is positive, and from
     negative infinity to 0 if 'lambd' is negative.

     Cambiato nella versione 3.12: Added the default value for ‘lambd’.

 -- Funzione: random.gammavariate (alpha, beta)

     Gamma distribution.  ('Not' the gamma function!)  The shape and
     scale parameters, 'alpha' and 'beta', must have positive values.
     (Calling conventions vary and some sources define “beta” as the
     inverse of the scale).

     The probability distribution function is:

                    x ** (alpha - 1) * math.exp(-x / beta)
          pdf(x) =  --------------------------------------
                      math.gamma(alpha) * beta ** alpha

 -- Funzione: random.gauss (mu=0.0, sigma=1.0)

     Normal distribution, also called the Gaussian distribution.  'mu'
     is the mean, and 'sigma' is the standard deviation.  This is
     slightly faster than the *note normalvariate(): 1bc1. function
     defined below.

     Multithreading note: When two threads call this function
     simultaneously, it is possible that they will receive the same
     return value.  This can be avoided in three ways.  1) Have each
     thread use a different instance of the random number generator.  2)
     Put locks around all calls.  3) Use the slower, but thread-safe
     *note normalvariate(): 1bc1. function instead.

     Cambiato nella versione 3.11: 'mu' and 'sigma' now have default
     arguments.

 -- Funzione: random.lognormvariate (mu, sigma)

     Log normal distribution.  If you take the natural logarithm of this
     distribution, you’ll get a normal distribution with mean 'mu' and
     standard deviation 'sigma'.  'mu' can have any value, and 'sigma'
     must be greater than zero.

 -- Funzione: random.normalvariate (mu=0.0, sigma=1.0)

     Normal distribution.  'mu' is the mean, and 'sigma' is the standard
     deviation.

     Cambiato nella versione 3.11: 'mu' and 'sigma' now have default
     arguments.

 -- Funzione: random.vonmisesvariate (mu, kappa)

     'mu' is the mean angle, expressed in radians between 0 and 2*'pi',
     and 'kappa' is the concentration parameter, which must be greater
     than or equal to zero.  If 'kappa' is equal to zero, this
     distribution reduces to a uniform random angle over the range 0 to
     2*'pi'.

 -- Funzione: random.paretovariate (alpha)

     Pareto distribution.  'alpha' is the shape parameter.

 -- Funzione: random.weibullvariate (alpha, beta)

     Weibull distribution.  'alpha' is the scale parameter and 'beta' is
     the shape parameter.


File: python.info,  Node: Alternative Generator,  Next: Notes on Reproducibility,  Prev: Real-valued distributions,  Up: random — Generate pseudo-random numbers

5.9.6.7 Alternative Generator
.............................

 -- Classe: random.Random ([seed])

     Class that implements the default pseudo-random number generator
     used by the *note random: bd. module.

     Cambiato nella versione 3.11: Formerly the 'seed' could be any
     hashable object.  Now it is limited to: ‘None’, *note int: 19b,
     *note float: 196, *note str: 169, *note bytes: 192, or *note
     bytearray: 344.

     Subclasses of ‘Random’ should override the following methods if
     they wish to make use of a different basic generator:

      -- Metodo: seed (a=None, version=2)

          Override this method in subclasses to customise the *note
          seed(): 147b. behaviour of ‘Random’ instances.

      -- Metodo: getstate ()

          Override this method in subclasses to customise the *note
          getstate(): 2b3f. behaviour of ‘Random’ instances.

      -- Metodo: setstate (state)

          Override this method in subclasses to customise the *note
          setstate(): 2b40. behaviour of ‘Random’ instances.

      -- Metodo: random ()

          Override this method in subclasses to customise the *note
          random(): 950. behaviour of ‘Random’ instances.

     Optionally, a custom generator subclass can also supply the
     following method:

      -- Metodo: getrandbits (k)

          Override this method in subclasses to customise the *note
          getrandbits(): 120f. behaviour of ‘Random’ instances.

      -- Metodo: randbytes (n)

          Override this method in subclasses to customise the *note
          randbytes(): 180e. behaviour of ‘Random’ instances.

 -- Classe: random.SystemRandom ([seed])

     Class that uses the *note os.urandom(): 747. function for
     generating random numbers from sources provided by the operating
     system.  Not available on all systems.  Does not rely on software
     state, and sequences are not reproducible.  Accordingly, the *note
     seed(): 147b. method has no effect and is ignored.  The *note
     getstate(): 2b3f. and *note setstate(): 2b40. methods raise *note
     NotImplementedError: 36b. if called.


File: python.info,  Node: Notes on Reproducibility,  Next: Examples<4>,  Prev: Alternative Generator,  Up: random — Generate pseudo-random numbers

5.9.6.8 Notes on Reproducibility
................................

Sometimes it is useful to be able to reproduce the sequences given by a
pseudo-random number generator.  By reusing a seed value, the same
sequence should be reproducible from run to run as long as multiple
threads are not running.

Most of the random module’s algorithms and seeding functions are subject
to change across Python versions, but two aspects are guaranteed not to
change:

   * If a new seeding method is added, then a backward compatible seeder
     will be offered.

   * The generator’s *note random(): 2b53. method will continue to
     produce the same sequence when the compatible seeder is given the
     same seed.


File: python.info,  Node: Examples<4>,  Next: Recipes<2>,  Prev: Notes on Reproducibility,  Up: random — Generate pseudo-random numbers

5.9.6.9 Examples
................

Basic examples:

     >>> random()                          # Random float:  0.0 <= x < 1.0
     0.37444887175646646

     >>> uniform(2.5, 10.0)                # Random float:  2.5 <= x <= 10.0
     3.1800146073117523

     >>> expovariate(1 / 5)                # Interval between arrivals averaging 5 seconds
     5.148957571865031

     >>> randrange(10)                     # Integer from 0 to 9 inclusive
     7

     >>> randrange(0, 101, 2)              # Even integer from 0 to 100 inclusive
     26

     >>> choice(['win', 'lose', 'draw'])   # Single random element from a sequence
     'draw'

     >>> deck = 'ace two three four'.split()
     >>> shuffle(deck)                     # Shuffle a list
     >>> deck
     ['four', 'two', 'ace', 'three']

     >>> sample([10, 20, 30, 40, 50], k=4) # Four samples without replacement
     [40, 10, 50, 30]

Simulations:

     >>> # Six roulette wheel spins (weighted sampling with replacement)
     >>> choices(['red', 'black', 'green'], [18, 18, 2], k=6)
     ['red', 'green', 'black', 'black', 'red', 'black']

     >>> # Deal 20 cards without replacement from a deck
     >>> # of 52 playing cards, and determine the proportion of cards
     >>> # with a ten-value:  ten, jack, queen, or king.
     >>> deal = sample(['tens', 'low cards'], counts=[16, 36], k=20)
     >>> deal.count('tens') / 20
     0.15

     >>> # Estimate the probability of getting 5 or more heads from 7 spins
     >>> # of a biased coin that settles on heads 60% of the time.
     >>> sum(binomialvariate(n=7, p=0.6) >= 5 for i in range(10_000)) / 10_000
     0.4169

     >>> # Probability of the median of 5 samples being in middle two quartiles
     >>> def trial():
     ...     return 2_500 <= sorted(choices(range(10_000), k=5))[2] < 7_500
     ...
     >>> sum(trial() for i in range(10_000)) / 10_000
     0.7958

Example of statistical bootstrapping(1) using resampling with
replacement to estimate a confidence interval for the mean of a sample:

     # https://www.thoughtco.com/example-of-bootstrapping-3126155
     from statistics import fmean as mean
     from random import choices

     data = [41, 50, 29, 37, 81, 30, 73, 63, 20, 35, 68, 22, 60, 31, 95]
     means = sorted(mean(choices(data, k=len(data))) for i in range(100))
     print(f'The sample mean of {mean(data):.1f} has a 90% confidence '
           f'interval from {means[5]:.1f} to {means[94]:.1f}')

Example of a resampling permutation test(2) to determine the statistical
significance or p-value(3) of an observed difference between the effects
of a drug versus a placebo:

     # Example from "Statistics is Easy" by Dennis Shasha and Manda Wilson
     from statistics import fmean as mean
     from random import shuffle

     drug = [54, 73, 53, 70, 73, 68, 52, 65, 65]
     placebo = [54, 51, 58, 44, 55, 52, 42, 47, 58, 46]
     observed_diff = mean(drug) - mean(placebo)

     n = 10_000
     count = 0
     combined = drug + placebo
     for i in range(n):
         shuffle(combined)
         new_diff = mean(combined[:len(drug)]) - mean(combined[len(drug):])
         count += (new_diff >= observed_diff)

     print(f'{n} label reshufflings produced only {count} instances with a difference')
     print(f'at least as extreme as the observed difference of {observed_diff:.1f}.')
     print(f'The one-sided p-value of {count / n:.4f} leads us to reject the null')
     print(f'hypothesis that there is no difference between the drug and the placebo.')

Simulation of arrival times and service deliveries for a multiserver
queue:

     from heapq import heapify, heapreplace
     from random import expovariate, gauss
     from statistics import mean, quantiles

     average_arrival_interval = 5.6
     average_service_time = 15.0
     stdev_service_time = 3.5
     num_servers = 3

     waits = []
     arrival_time = 0.0
     servers = [0.0] * num_servers  # time when each server becomes available
     heapify(servers)
     for i in range(1_000_000):
         arrival_time += expovariate(1.0 / average_arrival_interval)
         next_server_available = servers[0]
         wait = max(0.0, next_server_available - arrival_time)
         waits.append(wait)
         service_duration = max(0.0, gauss(average_service_time, stdev_service_time))
         service_completed = arrival_time + wait + service_duration
         heapreplace(servers, service_completed)

     print(f'Mean wait: {mean(waits):.1f}   Max wait: {max(waits):.1f}')
     print('Quartiles:', [round(q, 1) for q in quantiles(waits)])

Vedi anche
..........

Statistics for Hackers(4) a video tutorial by Jake Vanderplas(5) on
statistical analysis using just a few fundamental concepts including
simulation, sampling, shuffling, and cross-validation.

Economics Simulation(6) a simulation of a marketplace by Peter Norvig(7)
that shows effective use of many of the tools and distributions provided
by this module (gauss, uniform, sample, betavariate, choice, triangular,
and randrange).

A Concrete Introduction to Probability (using Python)(8) a tutorial by
Peter Norvig(9) covering the basics of probability theory, how to write
simulations, and how to perform data analysis using Python.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Bootstrapping_(statistics)

   (2) 
https://en.wikipedia.org/wiki/Resampling_(statistics)#Permutation_tests

   (3) https://en.wikipedia.org/wiki/P-value

   (4) https://www.youtube.com/watch?v=Iq9DzN6mvYA

   (5) https://us.pycon.org/2016/speaker/profile/295/

   (6) https://nbviewer.org/url/norvig.com/ipython/Economics.ipynb

   (7) https://norvig.com/bio.html

   (8) https://nbviewer.org/url/norvig.com/ipython/Probability.ipynb

   (9) https://norvig.com/bio.html


File: python.info,  Node: Recipes<2>,  Next: Command-line usage<2>,  Prev: Examples<4>,  Up: random — Generate pseudo-random numbers

5.9.6.10 Recipes
................

These recipes show how to efficiently make random selections from the
combinatoric iterators in the *note itertools: 85. module:

     import random

     def random_product(*iterables, repeat=1):
         "Random selection from itertools.product(*iterables, repeat=repeat)"
         pools = tuple(map(tuple, iterables)) * repeat
         return tuple(map(random.choice, pools))

     def random_permutation(iterable, r=None):
         "Random selection from itertools.permutations(iterable, r)"
         pool = tuple(iterable)
         r = len(pool) if r is None else r
         return tuple(random.sample(pool, r))

     def random_combination(iterable, r):
         "Random selection from itertools.combinations(iterable, r)"
         pool = tuple(iterable)
         n = len(pool)
         indices = sorted(random.sample(range(n), r))
         return tuple(pool[i] for i in indices)

     def random_combination_with_replacement(iterable, r):
         "Choose r elements with replacement.  Order the result to match the iterable."
         # Result will be in set(itertools.combinations_with_replacement(iterable, r)).
         pool = tuple(iterable)
         n = len(pool)
         indices = sorted(random.choices(range(n), k=r))
         return tuple(pool[i] for i in indices)

     def random_derangement(iterable):
         "Choose a permutation where no element stays in its original position."
         seq = tuple(iterable)
         if len(seq) < 2:
             if not seq:
                 return ()
             raise IndexError('No derangments to choose from')
         perm = list(range(len(seq)))
         start = tuple(perm)
         while True:
             random.shuffle(perm)
             if all(p != q for p, q in zip(start, perm)):
                 return tuple([seq[i] for i in perm])

The default *note random(): 950. returns multiples of 2⁻⁵³ in the range
'0.0 ≤ x < 1.0'.  All such numbers are evenly spaced and are exactly
representable as Python floats.  However, many other representable
floats in that interval are not possible selections.  For example,
‘0.05954861408025609’ isn’t an integer multiple of 2⁻⁵³.

The following recipe takes a different approach.  All floats in the
interval are possible selections.  The mantissa comes from a uniform
distribution of integers in the range '2⁵² ≤ mantissa < 2⁵³'.  The
exponent comes from a geometric distribution where exponents smaller
than '-53' occur half as often as the next larger exponent.

     from random import Random
     from math import ldexp

     class FullRandom(Random):

         def random(self):
             mantissa = 0x10_0000_0000_0000 | self.getrandbits(52)
             exponent = -53
             x = 0
             while not x:
                 x = self.getrandbits(32)
                 exponent += x.bit_length() - 32
             return ldexp(mantissa, exponent)

All *note real valued distributions: 2b47. in the class will use the new
method:

     >>> fr = FullRandom()
     >>> fr.random()
     0.05954861408025609
     >>> fr.expovariate(0.25)
     8.87925541791544

The recipe is conceptually equivalent to an algorithm that chooses from
all the multiples of 2⁻¹⁰⁷⁴ in the range '0.0 ≤ x < 1.0'.  All such
numbers are evenly spaced, but most have to be rounded down to the
nearest representable Python float.  (The value 2⁻¹⁰⁷⁴ is the smallest
positive unnormalized float and is equal to ‘math.ulp(0.0)’.)

Vedi anche
..........

Generating Pseudo-random Floating-Point Values(1) a paper by Allen B.
Downey describing ways to generate more fine-grained floats than
normally generated by *note random(): 950.

   ---------- Footnotes ----------

   (1) https://allendowney.com/research/rand/downey07randfloat.pdf


File: python.info,  Node: Command-line usage<2>,  Next: Command-line example,  Prev: Recipes<2>,  Up: random — Generate pseudo-random numbers

5.9.6.11 Command-line usage
...........................

Added in version 3.13.

The ‘random’ module can be executed from the command line.

     python -m random [-h] [-c CHOICE [CHOICE ...] | -i N | -f N] [input ...]

The following options are accepted:

 -- Option: -h, --help

     Show the help message and exit.

 -- Option: -c CHOICE [CHOICE ...]
 -- Option: --choice CHOICE [CHOICE ...]

     Print a random choice, using *note choice(): 1438.

 -- Option: -i <N>
 -- Option: --integer <N>

     Print a random integer between 1 and N inclusive, using *note
     randint(): 1437.

 -- Option: -f <N>
 -- Option: --float <N>

     Print a random floating-point number between 0 and N inclusive,
     using *note uniform(): 2b48.

If no options are given, the output depends on the input:

   * String or multiple: same as *note -choice: 2b5c.

   * Integer: same as *note -integer: 2b5e.

   * Float: same as *note -float: 2b60.


File: python.info,  Node: Command-line example,  Prev: Command-line usage<2>,  Up: random — Generate pseudo-random numbers

5.9.6.12 Command-line example
.............................

Here are some examples of the ‘random’ command-line interface:

     $ # Choose one at random
     $ python -m random egg bacon sausage spam "Lobster Thermidor aux crevettes with a Mornay sauce"
     Lobster Thermidor aux crevettes with a Mornay sauce

     $ # Random integer
     $ python -m random 6
     6

     $ # Random floating-point number
     $ python -m random 1.8
     1.7080016272295635

     $ # With explicit arguments
     $ python  -m random --choice egg bacon sausage spam "Lobster Thermidor aux crevettes with a Mornay sauce"
     egg

     $ python -m random --integer 6
     3

     $ python -m random --float 1.8
     1.5666339105010318

     $ python -m random --integer 6
     5

     $ python -m random --float 6
     3.1942323316565915


File: python.info,  Node: statistics — Mathematical statistics functions,  Prev: random — Generate pseudo-random numbers,  Up: Numeric and Mathematical Modules

5.9.7 ‘statistics’ — Mathematical statistics functions
------------------------------------------------------

Added in version 3.4.

'Source code:' Lib/statistics.py(1)

__________________________________________________________________

This module provides functions for calculating mathematical statistics
of numeric (*note Real: 25d1.-valued) data.

The module is not intended to be a competitor to third-party libraries
such as NumPy(2), SciPy(3), or proprietary full-featured statistics
packages aimed at professional statisticians such as Minitab, SAS and
Matlab.  It is aimed at the level of graphing and scientific
calculators.

Unless explicitly noted, these functions support *note int: 19b, *note
float: 196, *note Decimal: 1fe. and *note Fraction: 213.  Behaviour with
other types (whether in the numeric tower or not) is currently
unsupported.  Collections with a mix of types are also undefined and
implementation-dependent.  If your input data consists of mixed types,
you may be able to use *note map(): 19f. to ensure a consistent result,
for example: ‘map(float, input_data)’.

Some datasets use ‘NaN’ (not a number) values to represent missing data.
Since NaNs have unusual comparison semantics, they cause surprising or
undefined behaviors in the statistics functions that sort data or that
count occurrences.  The functions affected are ‘median()’,
‘median_low()’, ‘median_high()’, ‘median_grouped()’, ‘mode()’,
‘multimode()’, and ‘quantiles()’.  The ‘NaN’ values should be stripped
before calling these functions:

     >>> from statistics import median
     >>> from math import isnan
     >>> from itertools import filterfalse

     >>> data = [20.7, float('NaN'),19.2, 18.3, float('NaN'), 14.4]
     >>> sorted(data)  # This has surprising behavior
     [20.7, nan, 14.4, 18.3, 19.2, nan]
     >>> median(data)  # This result is unexpected
     16.35

     >>> sum(map(isnan, data))    # Number of missing values
     2
     >>> clean = list(filterfalse(isnan, data))  # Strip NaN values
     >>> clean
     [20.7, 19.2, 18.3, 14.4]
     >>> sorted(clean)  # Sorting now works as expected
     [14.4, 18.3, 19.2, 20.7]
     >>> median(clean)       # This result is now well defined
     18.75

* Menu:

* Averages and measures of central location::
* Measures of spread::
* Statistics for relations between two inputs::
* Function details::
* Exceptions: Exceptions<4>.
* NormalDist objects::
* Examples and Recipes: Examples and Recipes<2>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/statistics.py

   (2) https://numpy.org

   (3) https://scipy.org/


File: python.info,  Node: Averages and measures of central location,  Next: Measures of spread,  Up: statistics — Mathematical statistics functions

5.9.7.1 Averages and measures of central location
.................................................

These functions calculate an average or typical value from a population
or sample.

*note mean(): 8e2.          Arithmetic mean («average») of data.
                            
                            
*note fmean(): c2b.         Fast, floating-point arithmetic mean, with optional weighting.
                            
                            
*note geometric_mean(): c2c.Geometric mean of data.
                            
                            
*note harmonic_mean(): edf. Harmonic mean of data.
                            
                            
*note kde(): 553.           Estimate the probability density distribution of the data.
                            
                            
*note kde_random(): 554.    Random sampling from the PDF generated by kde().
                            
                            
*note median(): 2b67.       Median (middle value) of data.
                            
                            
*note median_low(): 2b68.   Low median of data.
                            
                            
*note median_high(): 2b69.  High median of data.
                            
                            
*note median_grouped(): 2b6a.Median (50th percentile) of grouped data.
                            
                            
*note mode(): c87.          Single mode (most common value) of discrete or nominal data.
                            
                            
*note multimode(): c2d.     List of modes (most common values) of discrete or nominal data.
                            
                            
*note quantiles(): c2e.     Divide data into intervals with equal probability.
                            


File: python.info,  Node: Measures of spread,  Next: Statistics for relations between two inputs,  Prev: Averages and measures of central location,  Up: statistics — Mathematical statistics functions

5.9.7.2 Measures of spread
..........................

These functions calculate a measure of how much the population or sample
tends to deviate from the typical or average values.

*note pstdev(): 1798.       Population standard deviation of data.
                            
                            
*note pvariance(): 2b6c.    Population variance of data.
                            
                            
*note stdev(): 8e4.         Sample standard deviation of data.
                            
                            
*note variance(): 8e3.      Sample variance of data.
                            


File: python.info,  Node: Statistics for relations between two inputs,  Next: Function details,  Prev: Measures of spread,  Up: statistics — Mathematical statistics functions

5.9.7.3 Statistics for relations between two inputs
...................................................

These functions calculate statistics regarding relations between two
inputs.

*note covariance(): a33.      Sample covariance for two variables.
                              
                              
*note correlation(): 6e4.     Pearson and Spearman’s correlation coefficients.
                              
                              
*note linear_regression(): a34.Slope and intercept for simple linear regression.
                              


File: python.info,  Node: Function details,  Next: Exceptions<4>,  Prev: Statistics for relations between two inputs,  Up: statistics — Mathematical statistics functions

5.9.7.4 Function details
........................

Note: The functions do not require the data given to them to be sorted.
However, for reading convenience, most of the examples show sorted
sequences.

 -- Funzione: statistics.mean (data)

     Return the sample arithmetic mean of 'data' which can be a sequence
     or iterable.

     The arithmetic mean is the sum of the data divided by the number of
     data points.  It is commonly called «the average», although it is
     only one of many different mathematical averages.  It is a measure
     of the central location of the data.

     If 'data' is empty, *note StatisticsError: 2b6f. will be raised.

     Some examples of use:

          >>> mean([1, 2, 3, 4, 4])
          2.8
          >>> mean([-1.0, 2.5, 3.25, 5.75])
          2.625

          >>> from fractions import Fraction as F
          >>> mean([F(3, 7), F(1, 21), F(5, 3), F(1, 3)])
          Fraction(13, 21)

          >>> from decimal import Decimal as D
          >>> mean([D("0.5"), D("0.75"), D("0.625"), D("0.375")])
          Decimal('0.5625')

          Nota: The mean is strongly affected by outliers(1) and is not
          necessarily a typical example of the data points.  For a more
          robust, although less efficient, measure of central
          tendency(2), see *note median(): 2b67.

          The sample mean gives an unbiased estimate of the true
          population mean, so that when taken on average over all the
          possible samples, ‘mean(sample)’ converges on the true mean of
          the entire population.  If 'data' represents the entire
          population rather than a sample, then ‘mean(data)’ is
          equivalent to calculating the true population mean μ.

 -- Funzione: statistics.fmean (data, weights=None)

     Convert 'data' to floats and compute the arithmetic mean.

     This runs faster than the *note mean(): 8e2. function and it always
     returns a *note float: 196.  The 'data' may be a sequence or
     iterable.  If the input dataset is empty, raises a *note
     StatisticsError: 2b6f.

          >>> fmean([3.5, 4.0, 5.25])
          4.25

     Optional weighting is supported.  For example, a professor assigns
     a grade for a course by weighting quizzes at 20%, homework at 20%,
     a midterm exam at 30%, and a final exam at 30%:

          >>> grades = [85, 92, 83, 91]
          >>> weights = [0.20, 0.20, 0.30, 0.30]
          >>> fmean(grades, weights)
          87.6

     If 'weights' is supplied, it must be the same length as the 'data'
     or a *note ValueError: 2ec. will be raised.

     Added in version 3.8.

     Cambiato nella versione 3.11: Added support for 'weights'.

 -- Funzione: statistics.geometric_mean (data)

     Convert 'data' to floats and compute the geometric mean.

     The geometric mean indicates the central tendency or typical value
     of the 'data' using the product of the values (as opposed to the
     arithmetic mean which uses their sum).

     Raises a *note StatisticsError: 2b6f. if the input dataset is
     empty, if it contains a zero, or if it contains a negative value.
     The 'data' may be a sequence or iterable.

     No special efforts are made to achieve exact results.  (However,
     this may change in the future.)

          >>> round(geometric_mean([54, 24, 36]), 1)
          36.0

     Added in version 3.8.

 -- Funzione: statistics.harmonic_mean (data, weights=None)

     Return the harmonic mean of 'data', a sequence or iterable of
     real-valued numbers.  If 'weights' is omitted or ‘None’, then equal
     weighting is assumed.

     The harmonic mean is the reciprocal of the arithmetic *note mean():
     8e2. of the reciprocals of the data.  For example, the harmonic
     mean of three values 'a', 'b' and 'c' will be equivalent to ‘3/(1/a
     + 1/b + 1/c)’.  If one of the values is zero, the result will be
     zero.

     The harmonic mean is a type of average, a measure of the central
     location of the data.  It is often appropriate when averaging
     ratios or rates, for example speeds.

     Suppose a car travels 10 km at 40 km/hr, then another 10 km at 60
     km/hr.  What is the average speed?

          >>> harmonic_mean([40, 60])
          48.0

     Suppose a car travels 40 km/hr for 5 km, and when traffic clears,
     speeds-up to 60 km/hr for the remaining 30 km of the journey.  What
     is the average speed?

          >>> harmonic_mean([40, 60], weights=[5, 30])
          56.0

     *note StatisticsError: 2b6f. is raised if 'data' is empty, any
     element is less than zero, or if the weighted sum isn’t positive.

     The current algorithm has an early-out when it encounters a zero in
     the input.  This means that the subsequent inputs are not tested
     for validity.  (This behavior may change in the future.)

     Added in version 3.6.

     Cambiato nella versione 3.10: Added support for 'weights'.

 -- Funzione: statistics.kde (data, h, kernel='normal', *,
          cumulative=False)

     Kernel Density Estimation (KDE)(3): Create a continuous probability
     density function or cumulative distribution function from discrete
     samples.

     The basic idea is to smooth the data using a kernel function(4).
     to help draw inferences about a population from a sample.

     The degree of smoothing is controlled by the scaling parameter 'h'
     which is called the bandwidth.  Smaller values emphasize local
     features while larger values give smoother results.

     The 'kernel' determines the relative weights of the sample data
     points.  Generally, the choice of kernel shape does not matter as
     much as the more influential bandwidth smoothing parameter.

     Kernels that give some weight to every sample point include
     'normal' ('gauss'), 'logistic', and 'sigmoid'.

     Kernels that only give weight to sample points within the bandwidth
     include 'rectangular' ('uniform'), 'triangular', 'parabolic'
     ('epanechnikov'), 'quartic' ('biweight'), 'triweight', and
     'cosine'.

     If 'cumulative' is true, will return a cumulative distribution
     function.

     A *note StatisticsError: 2b6f. will be raised if the 'data'
     sequence is empty.

     Wikipedia has an example(5) where we can use *note kde(): 553. to
     generate and plot a probability density function estimated from a
     small sample:

          >>> sample = [-2.1, -1.3, -0.4, 1.9, 5.1, 6.2]
          >>> f_hat = kde(sample, h=1.5)
          >>> xarr = [i/100 for i in range(-750, 1100)]
          >>> yarr = [f_hat(x) for x in xarr]

     The points in ‘xarr’ and ‘yarr’ can be used to make a PDF plot:

[image src="python-figures/kde_example.png" alt="Scatter plot of the estimated probability density function."]


     Added in version 3.13.

 -- Funzione: statistics.kde_random (data, h, kernel='normal', *,
          seed=None)

     Return a function that makes a random selection from the estimated
     probability density function produced by ‘kde(data, h, kernel)’.

     Providing a 'seed' allows reproducible selections.  In the future,
     the values may change slightly as more accurate kernel inverse CDF
     estimates are implemented.  The seed may be an integer, float, str,
     or bytes.

     A *note StatisticsError: 2b6f. will be raised if the 'data'
     sequence is empty.

     Continuing the example for *note kde(): 553, we can use *note
     kde_random(): 554. to generate new random selections from an
     estimated probability density function:

          >>> data = [-2.1, -1.3, -0.4, 1.9, 5.1, 6.2]
          >>> rand = kde_random(data, h=1.5, seed=8675309)
          >>> new_selections = [rand() for i in range(10)]
          >>> [round(x, 1) for x in new_selections]
          [0.7, 6.2, 1.2, 6.9, 7.0, 1.8, 2.5, -0.5, -1.8, 5.6]

     Added in version 3.13.

 -- Funzione: statistics.median (data)

     Return the median (middle value) of numeric data, using the common
     «mean of middle two» method.  If 'data' is empty, *note
     StatisticsError: 2b6f. is raised.  'data' can be a sequence or
     iterable.

     The median is a robust measure of central location and is less
     affected by the presence of outliers.  When the number of data
     points is odd, the middle data point is returned:

          >>> median([1, 3, 5])
          3

     When the number of data points is even, the median is interpolated
     by taking the average of the two middle values:

          >>> median([1, 3, 5, 7])
          4.0

     This is suited for when your data is discrete, and you don’t mind
     that the median may not be an actual data point.

     If the data is ordinal (supports order operations) but not numeric
     (doesn’t support addition), consider using *note median_low():
     2b68. or *note median_high(): 2b69. instead.

 -- Funzione: statistics.median_low (data)

     Return the low median of numeric data.  If 'data' is empty, *note
     StatisticsError: 2b6f. is raised.  'data' can be a sequence or
     iterable.

     The low median is always a member of the data set.  When the number
     of data points is odd, the middle value is returned.  When it is
     even, the smaller of the two middle values is returned.

          >>> median_low([1, 3, 5])
          3
          >>> median_low([1, 3, 5, 7])
          3

     Use the low median when your data are discrete and you prefer the
     median to be an actual data point rather than interpolated.

 -- Funzione: statistics.median_high (data)

     Return the high median of data.  If 'data' is empty, *note
     StatisticsError: 2b6f. is raised.  'data' can be a sequence or
     iterable.

     The high median is always a member of the data set.  When the
     number of data points is odd, the middle value is returned.  When
     it is even, the larger of the two middle values is returned.

          >>> median_high([1, 3, 5])
          3
          >>> median_high([1, 3, 5, 7])
          5

     Use the high median when your data are discrete and you prefer the
     median to be an actual data point rather than interpolated.

 -- Funzione: statistics.median_grouped (data, interval=1.0)

     Estimates the median for numeric data that has been grouped or
     binned(6) around the midpoints of consecutive, fixed-width
     intervals.

     The 'data' can be any iterable of numeric data with each value
     being exactly the midpoint of a bin.  At least one value must be
     present.

     The 'interval' is the width of each bin.

     For example, demographic information may have been summarized into
     consecutive ten-year age groups with each group being represented
     by the 5-year midpoints of the intervals:

          >>> from collections import Counter
          >>> demographics = Counter({
          ...    25: 172,   # 20 to 30 years old
          ...    35: 484,   # 30 to 40 years old
          ...    45: 387,   # 40 to 50 years old
          ...    55:  22,   # 50 to 60 years old
          ...    65:   6,   # 60 to 70 years old
          ... })
          ...

     The 50th percentile (median) is the 536th person out of the 1071
     member cohort.  That person is in the 30 to 40 year old age group.

     The regular *note median(): 2b67. function would assume that
     everyone in the tricenarian age group was exactly 35 years old.  A
     more tenable assumption is that the 484 members of that age group
     are evenly distributed between 30 and 40.  For that, we use *note
     median_grouped(): 2b6a.:

          >>> data = list(demographics.elements())
          >>> median(data)
          35
          >>> round(median_grouped(data, interval=10), 1)
          37.5

     The caller is responsible for making sure the data points are
     separated by exact multiples of 'interval'.  This is essential for
     getting a correct result.  The function does not check this
     precondition.

     Inputs may be any numeric type that can be coerced to a float
     during the interpolation step.

 -- Funzione: statistics.mode (data)

     Return the single most common data point from discrete or nominal
     'data'.  The mode (when it exists) is the most typical value and
     serves as a measure of central location.

     If there are multiple modes with the same frequency, returns the
     first one encountered in the 'data'.  If the smallest or largest of
     those is desired instead, use ‘min(multimode(data))’ or
     ‘max(multimode(data))’.  If the input 'data' is empty, *note
     StatisticsError: 2b6f. is raised.

     ‘mode’ assumes discrete data and returns a single value.  This is
     the standard treatment of the mode as commonly taught in schools:

          >>> mode([1, 1, 2, 3, 3, 3, 3, 4])
          3

     The mode is unique in that it is the only statistic in this package
     that also applies to nominal (non-numeric) data:

          >>> mode(["red", "blue", "blue", "red", "green", "red", "red"])
          'red'

     Only hashable inputs are supported.  To handle type *note set: 184,
     consider casting to *note frozenset: 7f3.  To handle type *note
     list: 24d, consider casting to *note tuple: 614.  For mixed or
     nested inputs, consider using this slower quadratic algorithm that
     only depends on equality tests: ‘max(data, key=data.count)’.

     Cambiato nella versione 3.8: Now handles multimodal datasets by
     returning the first mode encountered.  Formerly, it raised *note
     StatisticsError: 2b6f. when more than one mode was found.

 -- Funzione: statistics.multimode (data)

     Return a list of the most frequently occurring values in the order
     they were first encountered in the 'data'.  Will return more than
     one result if there are multiple modes or an empty list if the
     'data' is empty:

          >>> multimode('aabbbbccddddeeffffgg')
          ['b', 'd', 'f']
          >>> multimode('')
          []

     Added in version 3.8.

 -- Funzione: statistics.pstdev (data, mu=None)

     Return the population standard deviation (the square root of the
     population variance).  See *note pvariance(): 2b6c. for arguments
     and other details.

          >>> pstdev([1.5, 2.5, 2.5, 2.75, 3.25, 4.75])
          0.986893273527251

 -- Funzione: statistics.pvariance (data, mu=None)

     Return the population variance of 'data', a non-empty sequence or
     iterable of real-valued numbers.  Variance, or second moment about
     the mean, is a measure of the variability (spread or dispersion) of
     data.  A large variance indicates that the data is spread out; a
     small variance indicates it is clustered closely around the mean.

     If the optional second argument 'mu' is given, it should be the
     'population' mean of the 'data'.  It can also be used to compute
     the second moment around a point that is not the mean.  If it is
     missing or ‘None’ (the default), the arithmetic mean is
     automatically calculated.

     Use this function to calculate the variance from the entire
     population.  To estimate the variance from a sample, the *note
     variance(): 8e3. function is usually a better choice.

     Raises *note StatisticsError: 2b6f. if 'data' is empty.

     Examples:

          >>> data = [0.0, 0.25, 0.25, 1.25, 1.5, 1.75, 2.75, 3.25]
          >>> pvariance(data)
          1.25

     If you have already calculated the mean of your data, you can pass
     it as the optional second argument 'mu' to avoid recalculation:

          >>> mu = mean(data)
          >>> pvariance(data, mu)
          1.25

     Decimals and Fractions are supported:

          >>> from decimal import Decimal as D
          >>> pvariance([D("27.5"), D("30.25"), D("30.25"), D("34.5"), D("41.75")])
          Decimal('24.815')

          >>> from fractions import Fraction as F
          >>> pvariance([F(1, 4), F(5, 4), F(1, 2)])
          Fraction(13, 72)

          Nota: When called with the entire population, this gives the
          population variance σ².  When called on a sample instead, this
          is the biased sample variance s², also known as variance with
          N degrees of freedom.

          If you somehow know the true population mean μ, you may use
          this function to calculate the variance of a sample, giving
          the known population mean as the second argument.  Provided
          the data points are a random sample of the population, the
          result will be an unbiased estimate of the population
          variance.

 -- Funzione: statistics.stdev (data, xbar=None)

     Return the sample standard deviation (the square root of the sample
     variance).  See *note variance(): 8e3. for arguments and other
     details.

          >>> stdev([1.5, 2.5, 2.5, 2.75, 3.25, 4.75])
          1.0810874155219827

 -- Funzione: statistics.variance (data, xbar=None)

     Return the sample variance of 'data', an iterable of at least two
     real-valued numbers.  Variance, or second moment about the mean, is
     a measure of the variability (spread or dispersion) of data.  A
     large variance indicates that the data is spread out; a small
     variance indicates it is clustered closely around the mean.

     If the optional second argument 'xbar' is given, it should be the
     'sample' mean of 'data'.  If it is missing or ‘None’ (the default),
     the mean is automatically calculated.

     Use this function when your data is a sample from a population.  To
     calculate the variance from the entire population, see *note
     pvariance(): 2b6c.

     Raises *note StatisticsError: 2b6f. if 'data' has fewer than two
     values.

     Examples:

          >>> data = [2.75, 1.75, 1.25, 0.25, 0.5, 1.25, 3.5]
          >>> variance(data)
          1.3720238095238095

     If you have already calculated the sample mean of your data, you
     can pass it as the optional second argument 'xbar' to avoid
     recalculation:

          >>> m = mean(data)
          >>> variance(data, m)
          1.3720238095238095

     This function does not attempt to verify that you have passed the
     actual mean as 'xbar'.  Using arbitrary values for 'xbar' can lead
     to invalid or impossible results.

     Decimal and Fraction values are supported:

          >>> from decimal import Decimal as D
          >>> variance([D("27.5"), D("30.25"), D("30.25"), D("34.5"), D("41.75")])
          Decimal('31.01875')

          >>> from fractions import Fraction as F
          >>> variance([F(1, 6), F(1, 2), F(5, 3)])
          Fraction(67, 108)

          Nota: This is the sample variance s² with Bessel’s correction,
          also known as variance with N-1 degrees of freedom.  Provided
          that the data points are representative (e.g.  independent and
          identically distributed), the result should be an unbiased
          estimate of the true population variance.

          If you somehow know the actual population mean μ you should
          pass it to the *note pvariance(): 2b6c. function as the 'mu'
          parameter to get the variance of a sample.

 -- Funzione: statistics.quantiles (data, *, n=4, method='exclusive')

     Divide 'data' into 'n' continuous intervals with equal probability.
     Returns a list of ‘n - 1’ cut points separating the intervals.

     Set 'n' to 4 for quartiles (the default).  Set 'n' to 10 for
     deciles.  Set 'n' to 100 for percentiles which gives the 99 cuts
     points that separate 'data' into 100 equal sized groups.  Raises
     *note StatisticsError: 2b6f. if 'n' is not least 1.

     The 'data' can be any iterable containing sample data.  For
     meaningful results, the number of data points in 'data' should be
     larger than 'n'.  Raises *note StatisticsError: 2b6f. if there is
     not at least one data point.

     The cut points are linearly interpolated from the two nearest data
     points.  For example, if a cut point falls one-third of the
     distance between two sample values, ‘100’ and ‘112’, the cut-point
     will evaluate to ‘104’.

     The 'method' for computing quantiles can be varied depending on
     whether the 'data' includes or excludes the lowest and highest
     possible values from the population.

     The default 'method' is «exclusive» and is used for data sampled
     from a population that can have more extreme values than found in
     the samples.  The portion of the population falling below the
     'i-th' of 'm' sorted data points is computed as ‘i / (m + 1)’.
     Given nine sample values, the method sorts them and assigns the
     following percentiles: 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%.

     Setting the 'method' to «inclusive» is used for describing
     population data or for samples that are known to include the most
     extreme values from the population.  The minimum value in 'data' is
     treated as the 0th percentile and the maximum value is treated as
     the 100th percentile.  The portion of the population falling below
     the 'i-th' of 'm' sorted data points is computed as ‘(i - 1) / (m -
     1)’.  Given 11 sample values, the method sorts them and assigns the
     following percentiles: 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%,
     90%, 100%.

          # Decile cut points for empirically sampled data
          >>> data = [105, 129, 87, 86, 111, 111, 89, 81, 108, 92, 110,
          ...         100, 75, 105, 103, 109, 76, 119, 99, 91, 103, 129,
          ...         106, 101, 84, 111, 74, 87, 86, 103, 103, 106, 86,
          ...         111, 75, 87, 102, 121, 111, 88, 89, 101, 106, 95,
          ...         103, 107, 101, 81, 109, 104]
          >>> [round(q, 1) for q in quantiles(data, n=10)]
          [81.0, 86.2, 89.0, 99.4, 102.5, 103.6, 106.0, 109.8, 111.0]

     Added in version 3.8.

     Cambiato nella versione 3.13: No longer raises an exception for an
     input with only a single data point.  This allows quantile
     estimates to be built up one sample point at a time becoming
     gradually more refined with each new data point.

 -- Funzione: statistics.covariance (x, y, /)

     Return the sample covariance of two inputs 'x' and 'y'.  Covariance
     is a measure of the joint variability of two inputs.

     Both inputs must be of the same length (no less than two),
     otherwise *note StatisticsError: 2b6f. is raised.

     Examples:

          >>> x = [1, 2, 3, 4, 5, 6, 7, 8, 9]
          >>> y = [1, 2, 3, 1, 2, 3, 1, 2, 3]
          >>> covariance(x, y)
          0.75
          >>> z = [9, 8, 7, 6, 5, 4, 3, 2, 1]
          >>> covariance(x, z)
          -7.5
          >>> covariance(z, x)
          -7.5

     Added in version 3.10.

 -- Funzione: statistics.correlation (x, y, /, *, method='linear')

     Return the Pearson's correlation coefficient(7) for two inputs.
     Pearson’s correlation coefficient 'r' takes values between -1 and
     +1.  It measures the strength and direction of a linear
     relationship.

     If 'method' is «ranked», computes Spearman's rank correlation
     coefficient(8) for two inputs.  The data is replaced by ranks.
     Ties are averaged so that equal values receive the same rank.  The
     resulting coefficient measures the strength of a monotonic
     relationship.

     Spearman’s correlation coefficient is appropriate for ordinal data
     or for continuous data that doesn’t meet the linear proportion
     requirement for Pearson’s correlation coefficient.

     Both inputs must be of the same length (no less than two), and need
     not to be constant, otherwise *note StatisticsError: 2b6f. is
     raised.

     Example with Kepler's laws of planetary motion(9):

          >>> # Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and  Neptune
          >>> orbital_period = [88, 225, 365, 687, 4331, 10_756, 30_687, 60_190]    # days
          >>> dist_from_sun = [58, 108, 150, 228, 778, 1_400, 2_900, 4_500] # million km

          >>> # Show that a perfect monotonic relationship exists
          >>> correlation(orbital_period, dist_from_sun, method='ranked')
          1.0

          >>> # Observe that a linear relationship is imperfect
          >>> round(correlation(orbital_period, dist_from_sun), 4)
          0.9882

          >>> # Demonstrate Kepler's third law: There is a linear correlation
          >>> # between the square of the orbital period and the cube of the
          >>> # distance from the sun.
          >>> period_squared = [p * p for p in orbital_period]
          >>> dist_cubed = [d * d * d for d in dist_from_sun]
          >>> round(correlation(period_squared, dist_cubed), 4)
          1.0

     Added in version 3.10.

     Cambiato nella versione 3.12: Added support for Spearman’s rank
     correlation coefficient.

 -- Funzione: statistics.linear_regression (x, y, /, *,
          proportional=False)

     Return the slope and intercept of simple linear regression(10)
     parameters estimated using ordinary least squares.  Simple linear
     regression describes the relationship between an independent
     variable 'x' and a dependent variable 'y' in terms of this linear
     function:

          'y = slope * x + intercept + noise'

     where ‘slope’ and ‘intercept’ are the regression parameters that
     are estimated, and ‘noise’ represents the variability of the data
     that was not explained by the linear regression (it is equal to the
     difference between predicted and actual values of the dependent
     variable).

     Both inputs must be of the same length (no less than two), and the
     independent variable 'x' cannot be constant; otherwise a *note
     StatisticsError: 2b6f. is raised.

     For example, we can use the release dates of the Monty Python
     films(11) to predict the cumulative number of Monty Python films
     that would have been produced by 2019 assuming that they had kept
     the pace.

          >>> year = [1971, 1975, 1979, 1982, 1983]
          >>> films_total = [1, 2, 3, 4, 5]
          >>> slope, intercept = linear_regression(year, films_total)
          >>> round(slope * 2019 + intercept)
          16

     If 'proportional' is true, the independent variable 'x' and the
     dependent variable 'y' are assumed to be directly proportional.
     The data is fit to a line passing through the origin.  Since the
     'intercept' will always be 0.0, the underlying linear function
     simplifies to:

          'y = slope * x + noise'

     Continuing the example from *note correlation(): 6e4, we look to
     see how well a model based on major planets can predict the orbital
     distances for dwarf planets:

          >>> model = linear_regression(period_squared, dist_cubed, proportional=True)
          >>> slope = model.slope

          >>> # Dwarf planets:   Pluto,  Eris,    Makemake, Haumea, Ceres
          >>> orbital_periods = [90_560, 204_199, 111_845, 103_410, 1_680]  # days
          >>> predicted_dist = [math.cbrt(slope * (p * p)) for p in orbital_periods]
          >>> list(map(round, predicted_dist))
          [5912, 10166, 6806, 6459, 414]

          >>> [5_906, 10_152, 6_796, 6_450, 414]  # actual distance in million km
          [5906, 10152, 6796, 6450, 414]

     Added in version 3.10.

     Cambiato nella versione 3.11: Added support for 'proportional'.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Outlier

   (2) https://en.wikipedia.org/wiki/Central_tendency

   (3) 
https://www.itm-conferences.org/articles/itmconf/pdf/2018/08/itmconf_sam2018_00037.pdf

   (4) https://en.wikipedia.org/wiki/Kernel_(statistics)

   (5) https://en.wikipedia.org/wiki/Kernel_density_estimation#Example

   (6) https://en.wikipedia.org/wiki/Data_binning

   (7) https://en.wikipedia.org/wiki/Pearson_correlation_coefficient

   (8) 
https://en.wikipedia.org/wiki/Spearman%27s_rank_correlation_coefficient

   (9) https://en.wikipedia.org/wiki/Kepler's_laws_of_planetary_motion

   (10) https://en.wikipedia.org/wiki/Simple_linear_regression

   (11) https://en.wikipedia.org/wiki/Monty_Python#Films


File: python.info,  Node: Exceptions<4>,  Next: NormalDist objects,  Prev: Function details,  Up: statistics — Mathematical statistics functions

5.9.7.5 Exceptions
..................

A single exception is defined:

 -- Eccezione: statistics.StatisticsError

     Subclass of *note ValueError: 2ec. for statistics-related
     exceptions.


File: python.info,  Node: NormalDist objects,  Next: Examples and Recipes<2>,  Prev: Exceptions<4>,  Up: statistics — Mathematical statistics functions

5.9.7.6 ‘NormalDist’ objects
............................

*note NormalDist: c2f. is a tool for creating and manipulating normal
distributions of a random variable(1).  It is a class that treats the
mean and standard deviation of data measurements as a single entity.

Normal distributions arise from the Central Limit Theorem(2) and have a
wide range of applications in statistics.

 -- Classe: statistics.NormalDist (mu=0.0, sigma=1.0)

     Returns a new 'NormalDist' object where 'mu' represents the
     arithmetic mean(3) and 'sigma' represents the standard
     deviation(4).

     If 'sigma' is negative, raises *note StatisticsError: 2b6f.

      -- Attributo: mean

          A read-only property for the arithmetic mean(5) of a normal
          distribution.

      -- Attributo: median

          A read-only property for the median(6) of a normal
          distribution.

      -- Attributo: mode

          A read-only property for the mode(7) of a normal distribution.

      -- Attributo: stdev

          A read-only property for the standard deviation(8) of a normal
          distribution.

      -- Attributo: variance

          A read-only property for the variance(9) of a normal
          distribution.  Equal to the square of the standard deviation.

      -- Metodo: classmethod from_samples (data)

          Makes a normal distribution instance with 'mu' and 'sigma'
          parameters estimated from the 'data' using *note fmean(): c2b.
          and *note stdev(): 8e4.

          The 'data' can be any *note iterable: 142f. and should consist
          of values that can be converted to type *note float: 196.  If
          'data' does not contain at least two elements, raises *note
          StatisticsError: 2b6f. because it takes at least one point to
          estimate a central value and at least two points to estimate
          dispersion.

      -- Metodo: samples (n, *, seed=None)

          Generates 'n' random samples for a given mean and standard
          deviation.  Returns a *note list: 24d. of *note float: 196.
          values.

          If 'seed' is given, creates a new instance of the underlying
          random number generator.  This is useful for creating
          reproducible results, even in a multi-threading context.

          Cambiato nella versione 3.13.

          Switched to a faster algorithm.  To reproduce samples from
          previous versions, use *note random.seed(): 147b. and *note
          random.gauss(): 1bc0.

      -- Metodo: pdf (x)

          Using a probability density function (pdf)(10), compute the
          relative likelihood that a random variable 'X' will be near
          the given value 'x'.  Mathematically, it is the limit of the
          ratio ‘P(x <= X < x+dx) / dx’ as 'dx' approaches zero.

          The relative likelihood is computed as the probability of a
          sample occurring in a narrow range divided by the width of the
          range (hence the word «density»).  Since the likelihood is
          relative to other points, its value can be greater than ‘1.0’.

      -- Metodo: cdf (x)

          Using a cumulative distribution function (cdf)(11), compute
          the probability that a random variable 'X' will be less than
          or equal to 'x'.  Mathematically, it is written ‘P(X <= x)’.

      -- Metodo: inv_cdf (p)

          Compute the inverse cumulative distribution function, also
          known as the quantile function(12) or the percent-point(13)
          function.  Mathematically, it is written ‘x : P(X <= x) = p’.

          Finds the value 'x' of the random variable 'X' such that the
          probability of the variable being less than or equal to that
          value equals the given probability 'p'.

      -- Metodo: overlap (other)

          Measures the agreement between two normal probability
          distributions.  Returns a value between 0.0 and 1.0 giving the
          overlapping area for the two probability density
          functions(14).

      -- Metodo: quantiles (n=4)

          Divide the normal distribution into 'n' continuous intervals
          with equal probability.  Returns a list of (n - 1) cut points
          separating the intervals.

          Set 'n' to 4 for quartiles (the default).  Set 'n' to 10 for
          deciles.  Set 'n' to 100 for percentiles which gives the 99
          cuts points that separate the normal distribution into 100
          equal sized groups.

      -- Metodo: zscore (x)

          Compute the Standard Score(15) describing 'x' in terms of the
          number of standard deviations above or below the mean of the
          normal distribution: ‘(x - mean) / stdev’.

          Added in version 3.9.

     Instances of *note NormalDist: c2f. support addition, subtraction,
     multiplication and division by a constant.  These operations are
     used for translation and scaling.  For example:

          >>> temperature_february = NormalDist(5, 2.5)             # Celsius
          >>> temperature_february * (9/5) + 32                     # Fahrenheit
          NormalDist(mu=41.0, sigma=4.5)

     Dividing a constant by an instance of *note NormalDist: c2f. is not
     supported because the result wouldn’t be normally distributed.

     Since normal distributions arise from additive effects of
     independent variables, it is possible to add and subtract two
     independent normally distributed random variables(16) represented
     as instances of *note NormalDist: c2f.  For example:

          >>> birth_weights = NormalDist.from_samples([2.5, 3.1, 2.1, 2.4, 2.7, 3.5])
          >>> drug_effects = NormalDist(0.4, 0.15)
          >>> combined = birth_weights + drug_effects
          >>> round(combined.mean, 1)
          3.1
          >>> round(combined.stdev, 1)
          0.5

     Added in version 3.8.

   ---------- Footnotes ----------

   (1) http://www.stat.yale.edu/Courses/1997-98/101/ranvar.htm

   (2) https://en.wikipedia.org/wiki/Central_limit_theorem

   (3) https://en.wikipedia.org/wiki/Arithmetic_mean

   (4) https://en.wikipedia.org/wiki/Standard_deviation

   (5) https://en.wikipedia.org/wiki/Arithmetic_mean

   (6) https://en.wikipedia.org/wiki/Median

   (7) https://en.wikipedia.org/wiki/Mode_(statistics)

   (8) https://en.wikipedia.org/wiki/Standard_deviation

   (9) https://en.wikipedia.org/wiki/Variance

   (10) https://en.wikipedia.org/wiki/Probability_density_function

   (11) https://en.wikipedia.org/wiki/Cumulative_distribution_function

   (12) https://en.wikipedia.org/wiki/Quantile_function

   (13) 
https://web.archive.org/web/20190203145224/https://www.statisticshowto.datasciencecentral.com/inverse-distribution-function/

   (14) https://www.rasch.org/rmt/rmt101r.htm

   (15) 
https://www.statisticshowto.com/probability-and-statistics/z-score/

   (16) 
https://en.wikipedia.org/wiki/Sum_of_normally_distributed_random_variables


File: python.info,  Node: Examples and Recipes<2>,  Prev: NormalDist objects,  Up: statistics — Mathematical statistics functions

5.9.7.7 Examples and Recipes
............................

* Menu:

* Classic probability problems::
* Monte Carlo inputs for simulations::
* Approximating binomial distributions::
* Naive bayesian classifier::


File: python.info,  Node: Classic probability problems,  Next: Monte Carlo inputs for simulations,  Up: Examples and Recipes<2>

5.9.7.8 Classic probability problems
....................................

*note NormalDist: c2f. readily solves classic probability problems.

For example, given historical data for SAT exams(1) showing that scores
are normally distributed with a mean of 1060 and a standard deviation of
195, determine the percentage of students with test scores between 1100
and 1200, after rounding to the nearest whole number:

     >>> sat = NormalDist(1060, 195)
     >>> fraction = sat.cdf(1200 + 0.5) - sat.cdf(1100 - 0.5)
     >>> round(fraction * 100.0, 1)
     18.4

Find the quartiles(2) and deciles(3) for the SAT scores:

     >>> list(map(round, sat.quantiles()))
     [928, 1060, 1192]
     >>> list(map(round, sat.quantiles(n=10)))
     [810, 896, 958, 1011, 1060, 1109, 1162, 1224, 1310]

   ---------- Footnotes ----------

   (1) https://nces.ed.gov/programs/digest/d17/tables/dt17_226.40.asp

   (2) https://en.wikipedia.org/wiki/Quartile

   (3) https://en.wikipedia.org/wiki/Decile


File: python.info,  Node: Monte Carlo inputs for simulations,  Next: Approximating binomial distributions,  Prev: Classic probability problems,  Up: Examples and Recipes<2>

5.9.7.9 Monte Carlo inputs for simulations
..........................................

To estimate the distribution for a model that isn’t easy to solve
analytically, *note NormalDist: c2f. can generate input samples for a
Monte Carlo simulation(1):

     >>> def model(x, y, z):
     ...     return (3*x + 7*x*y - 5*y) / (11 * z)
     ...
     >>> n = 100_000
     >>> X = NormalDist(10, 2.5).samples(n, seed=3652260728)
     >>> Y = NormalDist(15, 1.75).samples(n, seed=4582495471)
     >>> Z = NormalDist(50, 1.25).samples(n, seed=6582483453)
     >>> quantiles(map(model, X, Y, Z))
     [1.4591308524824727, 1.8035946855390597, 2.175091447274739]

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Monte_Carlo_method


File: python.info,  Node: Approximating binomial distributions,  Next: Naive bayesian classifier,  Prev: Monte Carlo inputs for simulations,  Up: Examples and Recipes<2>

5.9.7.10 Approximating binomial distributions
.............................................

Normal distributions can be used to approximate Binomial
distributions(1) when the sample size is large and when the probability
of a successful trial is near 50%.

For example, an open source conference has 750 attendees and two rooms
with a 500 person capacity.  There is a talk about Python and another
about Ruby.  In previous conferences, 65% of the attendees preferred to
listen to Python talks.  Assuming the population preferences haven’t
changed, what is the probability that the Python room will stay within
its capacity limits?

     >>> n = 750             # Sample size
     >>> p = 0.65            # Preference for Python
     >>> q = 1.0 - p         # Preference for Ruby
     >>> k = 500             # Room capacity

     >>> # Approximation using the cumulative normal distribution
     >>> from math import sqrt
     >>> round(NormalDist(mu=n*p, sigma=sqrt(n*p*q)).cdf(k + 0.5), 4)
     0.8402

     >>> # Exact solution using the cumulative binomial distribution
     >>> from math import comb, fsum
     >>> round(fsum(comb(n, r) * p**r * q**(n-r) for r in range(k+1)), 4)
     0.8402

     >>> # Approximation using a simulation
     >>> from random import seed, binomialvariate
     >>> seed(8675309)
     >>> mean(binomialvariate(n, p) <= k for i in range(10_000))
     0.8406

   ---------- Footnotes ----------

   (1) https://mathworld.wolfram.com/BinomialDistribution.html


File: python.info,  Node: Naive bayesian classifier,  Prev: Approximating binomial distributions,  Up: Examples and Recipes<2>

5.9.7.11 Naive bayesian classifier
..................................

Normal distributions commonly arise in machine learning problems.

Wikipedia has a nice example of a Naive Bayesian Classifier(1).  The
challenge is to predict a person’s gender from measurements of normally
distributed features including height, weight, and foot size.

We’re given a training dataset with measurements for eight people.  The
measurements are assumed to be normally distributed, so we summarize the
data with *note NormalDist: c2f.:

     >>> height_male = NormalDist.from_samples([6, 5.92, 5.58, 5.92])
     >>> height_female = NormalDist.from_samples([5, 5.5, 5.42, 5.75])
     >>> weight_male = NormalDist.from_samples([180, 190, 170, 165])
     >>> weight_female = NormalDist.from_samples([100, 150, 130, 150])
     >>> foot_size_male = NormalDist.from_samples([12, 11, 12, 10])
     >>> foot_size_female = NormalDist.from_samples([6, 8, 7, 9])

Next, we encounter a new person whose feature measurements are known but
whose gender is unknown:

     >>> ht = 6.0        # height
     >>> wt = 130        # weight
     >>> fs = 8          # foot size

Starting with a 50% prior probability(2) of being male or female, we
compute the posterior as the prior times the product of likelihoods for
the feature measurements given the gender:

     >>> prior_male = 0.5
     >>> prior_female = 0.5
     >>> posterior_male = (prior_male * height_male.pdf(ht) *
     ...                   weight_male.pdf(wt) * foot_size_male.pdf(fs))

     >>> posterior_female = (prior_female * height_female.pdf(ht) *
     ...                     weight_female.pdf(wt) * foot_size_female.pdf(fs))

The final prediction goes to the largest posterior.  This is known as
the maximum a posteriori(3) or MAP:

     >>> 'male' if posterior_male > posterior_female else 'female'
     'female'

   ---------- Footnotes ----------

   (1) 
https://en.wikipedia.org/wiki/Naive_Bayes_classifier#Person_classification

   (2) https://en.wikipedia.org/wiki/Prior_probability

   (3) https://en.wikipedia.org/wiki/Maximum_a_posteriori_estimation


File: python.info,  Node: Functional Programming Modules,  Next: File and Directory Access,  Prev: Numeric and Mathematical Modules,  Up: The Python Standard Library

5.10 Functional Programming Modules
===================================

The modules described in this chapter provide functions and classes that
support a functional programming style, and general operations on
callables.

The following modules are documented in this chapter:

* Menu:

* itertools — Functions creating iterators for efficient looping::
* functools — Higher-order functions and operations on callable objects::
* operator — Standard operators as functions::


File: python.info,  Node: itertools — Functions creating iterators for efficient looping,  Next: functools — Higher-order functions and operations on callable objects,  Up: Functional Programming Modules

5.10.1 ‘itertools’ — Functions creating iterators for efficient looping
-----------------------------------------------------------------------

__________________________________________________________________

This module implements a number of *note iterator: 4c9. building blocks
inspired by constructs from APL, Haskell, and SML. Each has been recast
in a form suitable for Python.

The module standardizes a core set of fast, memory efficient tools that
are useful by themselves or in combination.  Together, they form an
«iterator algebra» making it possible to construct specialized tools
succinctly and efficiently in pure Python.

For instance, SML provides a tabulation tool: ‘tabulate(f)’ which
produces a sequence ‘f(0), f(1), ...’.  The same effect can be achieved
in Python by combining *note map(): 19f. and *note count(): 148b. to
form ‘map(f, count())’.

'Infinite iterators:'

Iterator               Arguments             Results                                               Example
                                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                   
*note count(): 148b.   [start[, step]]       start, start+step, start+2*step, …                    ‘count(10) → 10 11 12 13 14 ...’
                                                                                                   
                                                                                                   
*note cycle(): 2b88.   p                     p0, p1, … plast, p0, p1, …                            ‘cycle('ABCD') → A B C D A B C D ...’
                                                                                                   
                                                                                                   
*note repeat(): 1841.  elem [,n]             elem, elem, elem, … endlessly or up to n times        ‘repeat(10, 3) → 10 10 10’
                                                                                                   

'Iterators terminating on the shortest input sequence:'

Iterator                         Arguments                        Results                                               Example
                                                                                                                        
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                        
*note accumulate(): bf2.         p [,func]                        p0, p0+p1, p0+p1+p2, …                                ‘accumulate([1,2,3,4,5]) → 1 3 6 10 15’
                                                                                                                        
                                                                                                                        
*note batched(): 512.            p, n                             (p0, p1, …, p_n-1), …                                 ‘batched('ABCDEFG', n=3) → ABC DEF G’
                                                                                                                        
                                                                                                                        
*note chain(): 25bc.             p, q, …                          p0, p1, … plast, q0, q1, …                            ‘chain('ABC', 'DEF') → A B C D E F’
                                                                                                                        
                                                                                                                        
*note chain.from_iterable(): 2b89.iterable                        p0, p1, … plast, q0, q1, …                            ‘chain.from_iterable(['ABC', 'DEF']) → A B C D E F’
                                                                                                                        
                                                                                                                        
*note compress(): 148a.          data, selectors                  (d[0] if s[0]), (d[1] if s[1]), …                     ‘compress('ABCDEF', [1,0,1,0,1,1]) → A C E F’
                                                                                                                        
                                                                                                                        
*note dropwhile(): 2b8a.         predicate, seq                   seq[n], seq[n+1], starting when predicate fails       ‘dropwhile(lambda x: x<5, [1,4,6,3,8]) → 6 3 8’
                                                                                                                        
                                                                                                                        
*note filterfalse(): 25aa.       predicate, seq                   elements of seq where predicate(elem) fails           ‘filterfalse(lambda x: x<5, [1,4,6,3,8]) → 6 8’
                                                                                                                        
                                                                                                                        
*note groupby(): 2b8b.           iterable[, key]                  sub-iterators grouped by value of key(v)              ‘groupby(['A','B','DEF'], len) → (1, A B) (3, DEF)’
                                                                                                                        
                                                                                                                        
*note islice(): d45.             seq, [start,] stop [, step]      elements from seq[start:stop:step]                    ‘islice('ABCDEFG', 2, None) → C D E F G’
                                                                                                                        
                                                                                                                        
*note pairwise(): a18.           iterable                         (p[0], p[1]), (p[1], p[2])                            ‘pairwise('ABCDEFG') → AB BC CD DE EF FG’
                                                                                                                        
                                                                                                                        
*note starmap(): 12ec.           func, seq                        func(*seq[0]), func(*seq[1]), …                       ‘starmap(pow, [(2,5), (3,2), (10,3)]) → 32 9 1000’
                                                                                                                        
                                                                                                                        
*note takewhile(): 2b8c.         predicate, seq                   seq[0], seq[1], until predicate fails                 ‘takewhile(lambda x: x<5, [1,4,6,3,8]) → 1 4’
                                                                                                                        
                                                                                                                        
*note tee(): 2b8d.               it, n                            it1, it2, … itn splits one iterator into n            ‘tee('ABC', 2) → A B C, A B C’
                                                                                                                        
                                                                                                                        
*note zip_longest(): 14a6.       p, q, …                          (p[0], q[0]), (p[1], q[1]), …                         ‘zip_longest('ABCD', 'xy', fillvalue='-') → Ax By C- D-’
                                                                                                                        

'Combinatoric iterators:'

Iterator                                           Arguments                Results
                                                                            
----------------------------------------------------------------------------------------------------------------------------------------------
                                                                            
*note product(): 151a.                             p, q, … [repeat=1]       cartesian product, equivalent to a nested for-loop
                                                                            
                                                                            
*note permutations(): 1cc5.                        p[, r]                   r-length tuples, all possible orderings, no repeated elements
                                                                            
                                                                            
*note combinations(): 1519.                        p, r                     r-length tuples, in sorted order, no repeated elements
                                                                            
                                                                            
*note combinations_with_replacement(): 1489.       p, r                     r-length tuples, in sorted order, with repeated elements
                                                                            

Examples                                           Results
                                                   
---------------------------------------------------------------------------------------------------------------------
                                                   
‘product('ABCD', repeat=2)’                        ‘AA AB AC AD BA BB BC BD CA CB CC CD DA DB DC DD’
                                                   
                                                   
‘permutations('ABCD', 2)’                          ‘AB AC AD BA BC BD CA CB CD DA DB DC’
                                                   
                                                   
‘combinations('ABCD', 2)’                          ‘AB AC AD BC BD CD’
                                                   
                                                   
‘combinations_with_replacement('ABCD', 2)’         ‘AA AB AC AD BB BC BD CC CD DD’
                                                   

* Menu:

* Itertool Functions::
* Itertools Recipes::


File: python.info,  Node: Itertool Functions,  Next: Itertools Recipes,  Up: itertools — Functions creating iterators for efficient looping

5.10.1.1 Itertool Functions
...........................

The following functions all construct and return iterators.  Some
provide streams of infinite length, so they should only be accessed by
functions or loops that truncate the stream.

 -- Funzione: itertools.accumulate (iterable[, function, *,
          initial=None])

     Make an iterator that returns accumulated sums or accumulated
     results from other binary functions.

     The 'function' defaults to addition.  The 'function' should accept
     two arguments, an accumulated total and a value from the
     'iterable'.

     If an 'initial' value is provided, the accumulation will start with
     that value and the output will have one more element than the input
     iterable.

     Roughly equivalent to:

          def accumulate(iterable, function=operator.add, *, initial=None):
              'Return running totals'
              # accumulate([1,2,3,4,5]) → 1 3 6 10 15
              # accumulate([1,2,3,4,5], initial=100) → 100 101 103 106 110 115
              # accumulate([1,2,3,4,5], operator.mul) → 1 2 6 24 120

              iterator = iter(iterable)
              total = initial
              if initial is None:
                  try:
                      total = next(iterator)
                  except StopIteration:
                      return

              yield total
              for element in iterator:
                  total = function(total, element)
                  yield total

     To compute a running minimum, set 'function' to *note min(): 110d.
     For a running maximum, set 'function' to *note max(): 110e.  Or for
     a running product, set 'function' to *note operator.mul(): 2b90.
     To build an amortization table(1), accumulate the interest and
     apply payments:

          >>> data = [3, 4, 6, 2, 1, 9, 0, 7, 5, 8]
          >>> list(accumulate(data, max))              # running maximum
          [3, 4, 6, 6, 6, 9, 9, 9, 9, 9]
          >>> list(accumulate(data, operator.mul))     # running product
          [3, 12, 72, 144, 144, 1296, 0, 0, 0, 0]

          # Amortize a 5% loan of 1000 with 10 annual payments of 90
          >>> update = lambda balance, payment: round(balance * 1.05) - payment
          >>> list(accumulate(repeat(90, 10), update, initial=1_000))
          [1000, 960, 918, 874, 828, 779, 728, 674, 618, 559, 497]

     See *note functools.reduce(): 21a. for a similar function that
     returns only the final accumulated value.

     Added in version 3.2.

     Cambiato nella versione 3.3: Added the optional 'function'
     parameter.

     Cambiato nella versione 3.8: Added the optional 'initial'
     parameter.

 -- Funzione: itertools.batched (iterable, n, *, strict=False)

     Batch data from the 'iterable' into tuples of length 'n'.  The last
     batch may be shorter than 'n'.

     If 'strict' is true, will raise a *note ValueError: 2ec. if the
     final batch is shorter than 'n'.

     Loops over the input iterable and accumulates data into tuples up
     to size 'n'.  The input is consumed lazily, just enough to fill a
     batch.  The result is yielded as soon as the batch is full or when
     the input iterable is exhausted:

          >>> flattened_data = ['roses', 'red', 'violets', 'blue', 'sugar', 'sweet']
          >>> unflattened = list(batched(flattened_data, 2))
          >>> unflattened
          [('roses', 'red'), ('violets', 'blue'), ('sugar', 'sweet')]

     Roughly equivalent to:

          def batched(iterable, n, *, strict=False):
              # batched('ABCDEFG', 3) → ABC DEF G
              if n < 1:
                  raise ValueError('n must be at least one')
              iterator = iter(iterable)
              while batch := tuple(islice(iterator, n)):
                  if strict and len(batch) != n:
                      raise ValueError('batched(): incomplete batch')
                  yield batch

     Added in version 3.12.

     Cambiato nella versione 3.13: Added the 'strict' option.

 -- Funzione: itertools.chain (*iterables)

     Make an iterator that returns elements from the first iterable
     until it is exhausted, then proceeds to the next iterable, until
     all of the iterables are exhausted.  This combines multiple data
     sources into a single iterator.  Roughly equivalent to:

          def chain(*iterables):
              # chain('ABC', 'DEF') → A B C D E F
              for iterable in iterables:
                  yield from iterable

 -- Metodo: classmethod chain.from_iterable (iterable)

     Alternate constructor for *note chain(): 25bc.  Gets chained inputs
     from a single iterable argument that is evaluated lazily.  Roughly
     equivalent to:

          def from_iterable(iterables):
              # chain.from_iterable(['ABC', 'DEF']) → A B C D E F
              for iterable in iterables:
                  yield from iterable

 -- Funzione: itertools.combinations (iterable, r)

     Return 'r' length subsequences of elements from the input
     'iterable'.

     The output is a subsequence of *note product(): 151a. keeping only
     entries that are subsequences of the 'iterable'.  The length of the
     output is given by *note math.comb(): 8e0. which computes ‘n! / r!
     / (n - r)!’ when ‘0 ≤ r ≤ n’ or zero when ‘r > n’.

     The combination tuples are emitted in lexicographic order according
     to the order of the input 'iterable'.  If the input 'iterable' is
     sorted, the output tuples will be produced in sorted order.

     Elements are treated as unique based on their position, not on
     their value.  If the input elements are unique, there will be no
     repeated values within each combination.

     Roughly equivalent to:

          def combinations(iterable, r):
              # combinations('ABCD', 2) → AB AC AD BC BD CD
              # combinations(range(4), 3) → 012 013 023 123

              pool = tuple(iterable)
              n = len(pool)
              if r > n:
                  return
              indices = list(range(r))

              yield tuple(pool[i] for i in indices)
              while True:
                  for i in reversed(range(r)):
                      if indices[i] != i + n - r:
                          break
                  else:
                      return
                  indices[i] += 1
                  for j in range(i+1, r):
                      indices[j] = indices[j-1] + 1
                  yield tuple(pool[i] for i in indices)

 -- Funzione: itertools.combinations_with_replacement (iterable, r)

     Return 'r' length subsequences of elements from the input
     'iterable' allowing individual elements to be repeated more than
     once.

     The output is a subsequence of *note product(): 151a. that keeps
     only entries that are subsequences (with possible repeated
     elements) of the 'iterable'.  The number of subsequence returned is
     ‘(n + r - 1)! / r! / (n - 1)!’ when ‘n > 0’.

     The combination tuples are emitted in lexicographic order according
     to the order of the input 'iterable'.  if the input 'iterable' is
     sorted, the output tuples will be produced in sorted order.

     Elements are treated as unique based on their position, not on
     their value.  If the input elements are unique, the generated
     combinations will also be unique.

     Roughly equivalent to:

          def combinations_with_replacement(iterable, r):
              # combinations_with_replacement('ABC', 2) → AA AB AC BB BC CC

              pool = tuple(iterable)
              n = len(pool)
              if not n and r:
                  return
              indices = [0] * r

              yield tuple(pool[i] for i in indices)
              while True:
                  for i in reversed(range(r)):
                      if indices[i] != n - 1:
                          break
                  else:
                      return
                  indices[i:] = [indices[i] + 1] * (r - i)
                  yield tuple(pool[i] for i in indices)

     Added in version 3.1.

 -- Funzione: itertools.compress (data, selectors)

     Make an iterator that returns elements from 'data' where the
     corresponding element in 'selectors' is true.  Stops when either
     the 'data' or 'selectors' iterables have been exhausted.  Roughly
     equivalent to:

          def compress(data, selectors):
              # compress('ABCDEF', [1,0,1,0,1,1]) → A C E F
              return (datum for datum, selector in zip(data, selectors) if selector)

     Added in version 3.1.

 -- Funzione: itertools.count (start=0, step=1)

     Make an iterator that returns evenly spaced values beginning with
     'start'.  Can be used with *note map(): 19f. to generate
     consecutive data points or with *note zip(): 1a0. to add sequence
     numbers.  Roughly equivalent to:

          def count(start=0, step=1):
              # count(10) → 10 11 12 13 14 ...
              # count(2.5, 0.5) → 2.5 3.0 3.5 ...
              n = start
              while True:
                  yield n
                  n += step

     When counting with floating-point numbers, better accuracy can
     sometimes be achieved by substituting multiplicative code such as:
     ‘(start + step * i for i in count())’.

     Cambiato nella versione 3.1: Added 'step' argument and allowed
     non-integer arguments.

 -- Funzione: itertools.cycle (iterable)

     Make an iterator returning elements from the 'iterable' and saving
     a copy of each.  When the iterable is exhausted, return elements
     from the saved copy.  Repeats indefinitely.  Roughly equivalent to:

          def cycle(iterable):
              # cycle('ABCD') → A B C D A B C D A B C D ...

              saved = []
              for element in iterable:
                  yield element
                  saved.append(element)

              while saved:
                  for element in saved:
                      yield element

     This itertool may require significant auxiliary storage (depending
     on the length of the iterable).

 -- Funzione: itertools.dropwhile (predicate, iterable)

     Make an iterator that drops elements from the 'iterable' while the
     'predicate' is true and afterwards returns every element.  Roughly
     equivalent to:

          def dropwhile(predicate, iterable):
              # dropwhile(lambda x: x<5, [1,4,6,3,8]) → 6 3 8

              iterator = iter(iterable)
              for x in iterator:
                  if not predicate(x):
                      yield x
                      break

              for x in iterator:
                  yield x

     Note this does not produce 'any' output until the predicate first
     becomes false, so this itertool may have a lengthy start-up time.

 -- Funzione: itertools.filterfalse (predicate, iterable)

     Make an iterator that filters elements from the 'iterable'
     returning only those for which the 'predicate' returns a false
     value.  If 'predicate' is ‘None’, returns the items that are false.
     Roughly equivalent to:

          def filterfalse(predicate, iterable):
              # filterfalse(lambda x: x<5, [1,4,6,3,8]) → 6 8

              if predicate is None:
                  predicate = bool

              for x in iterable:
                  if not predicate(x):
                      yield x

 -- Funzione: itertools.groupby (iterable, key=None)

     Make an iterator that returns consecutive keys and groups from the
     'iterable'.  The 'key' is a function computing a key value for each
     element.  If not specified or is ‘None’, 'key' defaults to an
     identity function and returns the element unchanged.  Generally,
     the iterable needs to already be sorted on the same key function.

     The operation of *note groupby(): 2b8b. is similar to the ‘uniq’
     filter in Unix.  It generates a break or new group every time the
     value of the key function changes (which is why it is usually
     necessary to have sorted the data using the same key function).
     That behavior differs from SQL’s GROUP BY which aggregates common
     elements regardless of their input order.

     The returned group is itself an iterator that shares the underlying
     iterable with *note groupby(): 2b8b.  Because the source is shared,
     when the *note groupby(): 2b8b. object is advanced, the previous
     group is no longer visible.  So, if that data is needed later, it
     should be stored as a list:

          groups = []
          uniquekeys = []
          data = sorted(data, key=keyfunc)
          for k, g in groupby(data, keyfunc):
              groups.append(list(g))      # Store group iterator as a list
              uniquekeys.append(k)

     *note groupby(): 2b8b. is roughly equivalent to:

          def groupby(iterable, key=None):
              # [k for k, g in groupby('AAAABBBCCDAABBB')] → A B C D A B
              # [list(g) for k, g in groupby('AAAABBBCCD')] → AAAA BBB CC D

              keyfunc = (lambda x: x) if key is None else key
              iterator = iter(iterable)
              exhausted = False

              def _grouper(target_key):
                  nonlocal curr_value, curr_key, exhausted
                  yield curr_value
                  for curr_value in iterator:
                      curr_key = keyfunc(curr_value)
                      if curr_key != target_key:
                          return
                      yield curr_value
                  exhausted = True

              try:
                  curr_value = next(iterator)
              except StopIteration:
                  return
              curr_key = keyfunc(curr_value)

              while not exhausted:
                  target_key = curr_key
                  curr_group = _grouper(target_key)
                  yield curr_key, curr_group
                  if curr_key == target_key:
                      for _ in curr_group:
                          pass

 -- Funzione: itertools.islice (iterable, stop)

 -- Funzione: itertools.islice (iterable, start, stop[, step])

     Make an iterator that returns selected elements from the iterable.
     Works like sequence slicing but does not support negative values
     for 'start', 'stop', or 'step'.

     If 'start' is zero or ‘None’, iteration starts at zero.  Otherwise,
     elements from the iterable are skipped until 'start' is reached.

     If 'stop' is ‘None’, iteration continues until the input is
     exhausted, if at all.  Otherwise, it stops at the specified
     position.

     If 'step' is ‘None’, the step defaults to one.  Elements are
     returned consecutively unless 'step' is set higher than one which
     results in items being skipped.

     Roughly equivalent to:

          def islice(iterable, *args):
              # islice('ABCDEFG', 2) → A B
              # islice('ABCDEFG', 2, 4) → C D
              # islice('ABCDEFG', 2, None) → C D E F G
              # islice('ABCDEFG', 0, None, 2) → A C E G

              s = slice(*args)
              start = 0 if s.start is None else s.start
              stop = s.stop
              step = 1 if s.step is None else s.step
              if start < 0 or (stop is not None and stop < 0) or step <= 0:
                  raise ValueError

              indices = count() if stop is None else range(max(start, stop))
              next_i = start
              for i, element in zip(indices, iterable):
                  if i == next_i:
                      yield element
                      next_i += step

     If the input is an iterator, then fully consuming the 'islice'
     advances the input iterator by ‘max(start, stop)’ steps regardless
     of the 'step' value.

 -- Funzione: itertools.pairwise (iterable)

     Return successive overlapping pairs taken from the input
     'iterable'.

     The number of 2-tuples in the output iterator will be one fewer
     than the number of inputs.  It will be empty if the input iterable
     has fewer than two values.

     Roughly equivalent to:

          def pairwise(iterable):
              # pairwise('ABCDEFG') → AB BC CD DE EF FG

              iterator = iter(iterable)
              a = next(iterator, None)

              for b in iterator:
                  yield a, b
                  a = b

     Added in version 3.10.

 -- Funzione: itertools.permutations (iterable, r=None)

     Return successive 'r' length permutations of elements(2) from the
     'iterable'.

     If 'r' is not specified or is ‘None’, then 'r' defaults to the
     length of the 'iterable' and all possible full-length permutations
     are generated.

     The output is a subsequence of *note product(): 151a. where entries
     with repeated elements have been filtered out.  The length of the
     output is given by *note math.perm(): 8e1. which computes ‘n! / (n
     - r)!’ when ‘0 ≤ r ≤ n’ or zero when ‘r > n’.

     The permutation tuples are emitted in lexicographic order according
     to the order of the input 'iterable'.  If the input 'iterable' is
     sorted, the output tuples will be produced in sorted order.

     Elements are treated as unique based on their position, not on
     their value.  If the input elements are unique, there will be no
     repeated values within a permutation.

     Roughly equivalent to:

          def permutations(iterable, r=None):
              # permutations('ABCD', 2) → AB AC AD BA BC BD CA CB CD DA DB DC
              # permutations(range(3)) → 012 021 102 120 201 210

              pool = tuple(iterable)
              n = len(pool)
              r = n if r is None else r
              if r > n:
                  return

              indices = list(range(n))
              cycles = list(range(n, n-r, -1))
              yield tuple(pool[i] for i in indices[:r])

              while n:
                  for i in reversed(range(r)):
                      cycles[i] -= 1
                      if cycles[i] == 0:
                          indices[i:] = indices[i+1:] + indices[i:i+1]
                          cycles[i] = n - i
                      else:
                          j = cycles[i]
                          indices[i], indices[-j] = indices[-j], indices[i]
                          yield tuple(pool[i] for i in indices[:r])
                          break
                  else:
                      return

 -- Funzione: itertools.product (*iterables, repeat=1)

     Cartesian product(3) of the input iterables.

     Roughly equivalent to nested for-loops in a generator expression.
     For example, ‘product(A, B)’ returns the same as ‘((x,y) for x in A
     for y in B)’.

     The nested loops cycle like an odometer with the rightmost element
     advancing on every iteration.  This pattern creates a lexicographic
     ordering so that if the input’s iterables are sorted, the product
     tuples are emitted in sorted order.

     To compute the product of an iterable with itself, specify the
     number of repetitions with the optional 'repeat' keyword argument.
     For example, ‘product(A, repeat=4)’ means the same as ‘product(A,
     A, A, A)’.

     This function is roughly equivalent to the following code, except
     that the actual implementation does not build up intermediate
     results in memory:

          def product(*iterables, repeat=1):
              # product('ABCD', 'xy') → Ax Ay Bx By Cx Cy Dx Dy
              # product(range(2), repeat=3) → 000 001 010 011 100 101 110 111

              if repeat < 0:
                  raise ValueError('repeat argument cannot be negative')
              pools = [tuple(pool) for pool in iterables] * repeat

              result = [[]]
              for pool in pools:
                  result = [x+[y] for x in result for y in pool]

              for prod in result:
                  yield tuple(prod)

     Before *note product(): 151a. runs, it completely consumes the
     input iterables, keeping pools of values in memory to generate the
     products.  Accordingly, it is only useful with finite inputs.

 -- Funzione: itertools.repeat (object[, times])

     Make an iterator that returns 'object' over and over again.  Runs
     indefinitely unless the 'times' argument is specified.

     Roughly equivalent to:

          def repeat(object, times=None):
              # repeat(10, 3) → 10 10 10
              if times is None:
                  while True:
                      yield object
              else:
                  for i in range(times):
                      yield object

     A common use for 'repeat' is to supply a stream of constant values
     to 'map' or 'zip':

          >>> list(map(pow, range(10), repeat(2)))
          [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

 -- Funzione: itertools.starmap (function, iterable)

     Make an iterator that computes the 'function' using arguments
     obtained from the 'iterable'.  Used instead of *note map(): 19f.
     when argument parameters have already been «pre-zipped» into
     tuples.

     The difference between *note map(): 19f. and *note starmap(): 12ec.
     parallels the distinction between ‘function(a,b)’ and
     ‘function(*c)’.  Roughly equivalent to:

          def starmap(function, iterable):
              # starmap(pow, [(2,5), (3,2), (10,3)]) → 32 9 1000
              for args in iterable:
                  yield function(*args)

 -- Funzione: itertools.takewhile (predicate, iterable)

     Make an iterator that returns elements from the 'iterable' as long
     as the 'predicate' is true.  Roughly equivalent to:

          def takewhile(predicate, iterable):
              # takewhile(lambda x: x<5, [1,4,6,3,8]) → 1 4
              for x in iterable:
                  if not predicate(x):
                      break
                  yield x

     Note, the element that first fails the predicate condition is
     consumed from the input iterator and there is no way to access it.
     This could be an issue if an application wants to further consume
     the input iterator after 'takewhile' has been run to exhaustion.
     To work around this problem, consider using more-itertools
     before_and_after()(4) instead.

 -- Funzione: itertools.tee (iterable, n=2)

     Return 'n' independent iterators from a single iterable.

     Roughly equivalent to:

          def tee(iterable, n=2):
              if n < 0:
                  raise ValueError
              if n == 0:
                  return ()
              iterator = _tee(iterable)
              result = [iterator]
              for _ in range(n - 1):
                  result.append(_tee(iterator))
              return tuple(result)

          class _tee:

              def __init__(self, iterable):
                  it = iter(iterable)
                  if isinstance(it, _tee):
                      self.iterator = it.iterator
                      self.link = it.link
                  else:
                      self.iterator = it
                      self.link = [None, None]

              def __iter__(self):
                  return self

              def __next__(self):
                  link = self.link
                  if link[1] is None:
                      link[0] = next(self.iterator)
                      link[1] = [None, None]
                  value, self.link = link
                  return value

     When the input 'iterable' is already a tee iterator object, all
     members of the return tuple are constructed as if they had been
     produced by the upstream *note tee(): 2b8d. call.  This «flattening
     step» allows nested *note tee(): 2b8d. calls to share the same
     underlying data chain and to have a single update step rather than
     a chain of calls.

     The flattening property makes tee iterators efficiently peekable:

          def lookahead(tee_iterator):
               "Return the next value without moving the input forward"
               [forked_iterator] = tee(tee_iterator, 1)
               return next(forked_iterator)

          >>> iterator = iter('abcdef')
          >>> [iterator] = tee(iterator, 1)   # Make the input peekable
          >>> next(iterator)                  # Move the iterator forward
          'a'
          >>> lookahead(iterator)             # Check next value
          'b'
          >>> next(iterator)                  # Continue moving forward
          'b'

     ‘tee’ iterators are not threadsafe.  A *note RuntimeError: 244. may
     be raised when simultaneously using iterators returned by the same
     *note tee(): 2b8d. call, even if the original 'iterable' is
     threadsafe.

     This itertool may require significant auxiliary storage (depending
     on how much temporary data needs to be stored).  In general, if one
     iterator uses most or all of the data before another iterator
     starts, it is faster to use *note list(): 24d. instead of *note
     tee(): 2b8d.

 -- Funzione: itertools.zip_longest (*iterables, fillvalue=None)

     Make an iterator that aggregates elements from each of the
     'iterables'.

     If the iterables are of uneven length, missing values are filled-in
     with 'fillvalue'.  If not specified, 'fillvalue' defaults to
     ‘None’.

     Iteration continues until the longest iterable is exhausted.

     Roughly equivalent to:

          def zip_longest(*iterables, fillvalue=None):
              # zip_longest('ABCD', 'xy', fillvalue='-') → Ax By C- D-

              iterators = list(map(iter, iterables))
              num_active = len(iterators)
              if not num_active:
                  return

              while True:
                  values = []
                  for i, iterator in enumerate(iterators):
                      try:
                          value = next(iterator)
                      except StopIteration:
                          num_active -= 1
                          if not num_active:
                              return
                          iterators[i] = repeat(fillvalue)
                          value = fillvalue
                      values.append(value)
                  yield tuple(values)

     If one of the iterables is potentially infinite, then the *note
     zip_longest(): 14a6. function should be wrapped with something that
     limits the number of calls (for example *note islice(): d45. or
     *note takewhile(): 2b8c.).

   ---------- Footnotes ----------

   (1) https://www.ramseysolutions.com/real-estate/amortization-schedule

   (2) https://www.britannica.com/science/permutation

   (3) https://en.wikipedia.org/wiki/Cartesian_product

   (4) 
https://more-itertools.readthedocs.io/en/stable/api.html#more_itertools.before_and_after


File: python.info,  Node: Itertools Recipes,  Prev: Itertool Functions,  Up: itertools — Functions creating iterators for efficient looping

5.10.1.2 Itertools Recipes
..........................

This section shows recipes for creating an extended toolset using the
existing itertools as building blocks.

The primary purpose of the itertools recipes is educational.  The
recipes show various ways of thinking about individual tools — for
example, that ‘chain.from_iterable’ is related to the concept of
flattening.  The recipes also give ideas about ways that the tools can
be combined — for example, how ‘starmap()’ and ‘repeat()’ can work
together.  The recipes also show patterns for using itertools with the
*note operator: a3. and *note collections: 1e. modules as well as with
the built-in itertools such as ‘map()’, ‘filter()’, ‘reversed()’, and
‘enumerate()’.

A secondary purpose of the recipes is to serve as an incubator.  The
‘accumulate()’, ‘compress()’, and ‘pairwise()’ itertools started out as
recipes.  Currently, the ‘sliding_window()’, ‘derangements()’, and
‘sieve()’ recipes are being tested to see whether they prove their
worth.

Substantially all of these recipes and many, many others can be
installed from the more-itertools(1) project found on the Python Package
Index:

     python -m pip install more-itertools

Many of the recipes offer the same high performance as the underlying
toolset.  Superior memory performance is kept by processing elements one
at a time rather than bringing the whole iterable into memory all at
once.  Code volume is kept small by linking the tools together in a
functional style(2).  High speed is retained by preferring «vectorized»
building blocks over the use of for-loops and *note generators: 1263.
which incur interpreter overhead.

     from itertools import (accumulate, batched, chain, combinations, compress,
          count, cycle, filterfalse, groupby, islice, permutations, product,
          repeat, starmap, tee, zip_longest)
     from collections import Counter, deque
     from contextlib import suppress
     from functools import reduce
     from math import comb, isqrt, prod, sumprod
     from operator import getitem, is_not, itemgetter, mul, neg

     # ==== Basic one liners ====

     def take(n, iterable):
         "Return first n items of the iterable as a list."
         return list(islice(iterable, n))

     def prepend(value, iterable):
         "Prepend a single value in front of an iterable."
         # prepend(1, [2, 3, 4]) → 1 2 3 4
         return chain([value], iterable)

     def tabulate(function, start=0):
         "Return function(0), function(1), ..."
         return map(function, count(start))

     def repeatfunc(function, times=None, *args):
         "Repeat calls to a function with specified arguments."
         if times is None:
             return starmap(function, repeat(args))
         return starmap(function, repeat(args, times))

     def flatten(list_of_lists):
         "Flatten one level of nesting."
         return chain.from_iterable(list_of_lists)

     def ncycles(iterable, n):
         "Returns the sequence elements n times."
         return chain.from_iterable(repeat(tuple(iterable), n))

     def loops(n):
         "Loop n times. Like range(n) but without creating integers."
         # for _ in loops(100): ...
         return repeat(None, n)

     def tail(n, iterable):
         "Return an iterator over the last n items."
         # tail(3, 'ABCDEFG') → E F G
         return iter(deque(iterable, maxlen=n))

     def consume(iterator, n=None):
         "Advance the iterator n-steps ahead. If n is None, consume entirely."
         # Use functions that consume iterators at C speed.
         if n is None:
             deque(iterator, maxlen=0)
         else:
             next(islice(iterator, n, n), None)

     def nth(iterable, n, default=None):
         "Returns the nth item or a default value."
         return next(islice(iterable, n, None), default)

     def quantify(iterable, predicate=bool):
         "Given a predicate that returns True or False, count the True results."
         return sum(map(predicate, iterable))

     def first_true(iterable, default=False, predicate=None):
         "Returns the first true value or the *default* if there is no true value."
         # first_true([a, b, c], x) → a or b or c or x
         # first_true([a, b], x, f) → a if f(a) else b if f(b) else x
         return next(filter(predicate, iterable), default)

     def all_equal(iterable, key=None):
         "Returns True if all the elements are equal to each other."
         # all_equal('4٤௪౪໔', key=int) → True
         return len(take(2, groupby(iterable, key))) <= 1

     # ==== Data pipelines ====

     def unique_justseen(iterable, key=None):
         "Yield unique elements, preserving order. Remember only the element just seen."
         # unique_justseen('AAAABBBCCDAABBB') → A B C D A B
         # unique_justseen('ABBcCAD', str.casefold) → A B c A D
         if key is None:
             return map(itemgetter(0), groupby(iterable))
         return map(next, map(itemgetter(1), groupby(iterable, key)))

     def unique_everseen(iterable, key=None):
         "Yield unique elements, preserving order. Remember all elements ever seen."
         # unique_everseen('AAAABBBCCDAABBB') → A B C D
         # unique_everseen('ABBcCAD', str.casefold) → A B c D
         seen = set()
         if key is None:
             for element in filterfalse(seen.__contains__, iterable):
                 seen.add(element)
                 yield element
         else:
             for element in iterable:
                 k = key(element)
                 if k not in seen:
                     seen.add(k)
                     yield element

     def unique(iterable, key=None, reverse=False):
        "Yield unique elements in sorted order. Supports unhashable inputs."
        # unique([[1, 2], [3, 4], [1, 2]]) → [1, 2] [3, 4]
        sequenced = sorted(iterable, key=key, reverse=reverse)
        return unique_justseen(sequenced, key=key)

     def sliding_window(iterable, n):
         "Collect data into overlapping fixed-length chunks or blocks."
         # sliding_window('ABCDEFG', 3) → ABC BCD CDE DEF EFG
         iterator = iter(iterable)
         window = deque(islice(iterator, n - 1), maxlen=n)
         for x in iterator:
             window.append(x)
             yield tuple(window)

     def grouper(iterable, n, *, incomplete='fill', fillvalue=None):
         "Collect data into non-overlapping fixed-length chunks or blocks."
         # grouper('ABCDEFG', 3, fillvalue='x')       → ABC DEF Gxx
         # grouper('ABCDEFG', 3, incomplete='strict') → ABC DEF ValueError
         # grouper('ABCDEFG', 3, incomplete='ignore') → ABC DEF
         iterators = [iter(iterable)] * n
         match incomplete:
             case 'fill':
                 return zip_longest(*iterators, fillvalue=fillvalue)
             case 'strict':
                 return zip(*iterators, strict=True)
             case 'ignore':
                 return zip(*iterators)
             case _:
                 raise ValueError('Expected fill, strict, or ignore')

     def roundrobin(*iterables):
         "Visit input iterables in a cycle until each is exhausted."
         # roundrobin('ABC', 'D', 'EF') → A D E B F C
         # Algorithm credited to George Sakkis
         iterators = map(iter, iterables)
         for num_active in range(len(iterables), 0, -1):
             iterators = cycle(islice(iterators, num_active))
             yield from map(next, iterators)

     def subslices(seq):
         "Return all contiguous non-empty subslices of a sequence."
         # subslices('ABCD') → A AB ABC ABCD B BC BCD C CD D
         slices = starmap(slice, combinations(range(len(seq) + 1), 2))
         return map(getitem, repeat(seq), slices)

     def derangements(iterable, r=None):
         "Produce r length permutations without fixed points."
         # derangements('ABCD') → BADC BCDA BDAC CADB CDAB CDBA DABC DCAB DCBA
         # Algorithm credited to Stefan Pochmann
         seq = tuple(iterable)
         pos = tuple(range(len(seq)))
         have_moved = map(map, repeat(is_not), repeat(pos), permutations(pos, r=r))
         valid_derangements = map(all, have_moved)
         return compress(permutations(seq, r=r), valid_derangements)

     def iter_index(iterable, value, start=0, stop=None):
         "Return indices where a value occurs in a sequence or iterable."
         # iter_index('AABCADEAF', 'A') → 0 1 4 7
         seq_index = getattr(iterable, 'index', None)
         if seq_index is None:
             iterator = islice(iterable, start, stop)
             for i, element in enumerate(iterator, start):
                 if element is value or element == value:
                     yield i
         else:
             stop = len(iterable) if stop is None else stop
             i = start
             with suppress(ValueError):
                 while True:
                     yield (i := seq_index(value, i, stop))
                     i += 1

     def iter_except(function, exception, first=None):
         "Convert a call-until-exception interface to an iterator interface."
         # iter_except(d.popitem, KeyError) → non-blocking dictionary iterator
         with suppress(exception):
             if first is not None:
                 yield first()
             while True:
                 yield function()

     # ==== Mathematical operations ====

     def multinomial(*counts):
         "Number of distinct arrangements of a multiset."
         # Counter('abracadabra').values() → 5 2 2 1 1
         # multinomial(5, 2, 2, 1, 1) → 83160
         return prod(map(comb, accumulate(counts), counts))

     def powerset(iterable):
         "Subsequences of the iterable from shortest to longest."
         # powerset([1,2,3]) → () (1,) (2,) (3,) (1,2) (1,3) (2,3) (1,2,3)
         s = list(iterable)
         return chain.from_iterable(combinations(s, r) for r in range(len(s)+1))

     def sum_of_squares(iterable):
         "Add up the squares of the input values."
         # sum_of_squares([10, 20, 30]) → 1400
         return sumprod(*tee(iterable))

     # ==== Matrix operations ====

     def reshape(matrix, columns):
         "Reshape a 2-D matrix to have a given number of columns."
         # reshape([(0, 1), (2, 3), (4, 5)], 3) →  (0, 1, 2) (3, 4, 5)
         return batched(chain.from_iterable(matrix), columns, strict=True)

     def transpose(matrix):
         "Swap the rows and columns of a 2-D matrix."
         # transpose([(1, 2, 3), (11, 22, 33)]) → (1, 11) (2, 22) (3, 33)
         return zip(*matrix, strict=True)

     def matmul(m1, m2):
         "Multiply two matrices."
         # matmul([(7, 5), (3, 5)], [(2, 5), (7, 9)]) → (49, 80) (41, 60)
         n = len(m2[0])
         return batched(starmap(sumprod, product(m1, transpose(m2))), n)

     # ==== Polynomial arithmetic ====

     def convolve(signal, kernel):
         """Discrete linear convolution of two iterables.
         Equivalent to polynomial multiplication.

         Convolutions are mathematically commutative; however, the inputs are
         evaluated differently.  The signal is consumed lazily and can be
         infinite. The kernel is fully consumed before the calculations begin.

         Article:  https://betterexplained.com/articles/intuitive-convolution/
         Video:    https://www.youtube.com/watch?v=KuXjwB4LzSA
         """
         # convolve([1, -1, -20], [1, -3]) → 1 -4 -17 60
         # convolve(data, [0.25, 0.25, 0.25, 0.25]) → Moving average (blur)
         # convolve(data, [1/2, 0, -1/2]) → 1st derivative estimate
         # convolve(data, [1, -2, 1]) → 2nd derivative estimate
         kernel = tuple(kernel)[::-1]
         n = len(kernel)
         padded_signal = chain(repeat(0, n-1), signal, repeat(0, n-1))
         windowed_signal = sliding_window(padded_signal, n)
         return map(sumprod, repeat(kernel), windowed_signal)

     def polynomial_from_roots(roots):
         """Compute a polynomial's coefficients from its roots.

            (x - 5) (x + 4) (x - 3)  expands to:   x³ -4x² -17x + 60
         """
         # polynomial_from_roots([5, -4, 3]) → [1, -4, -17, 60]
         factors = zip(repeat(1), map(neg, roots))
         return list(reduce(convolve, factors, [1]))

     def polynomial_eval(coefficients, x):
         """Evaluate a polynomial at a specific value.

         Computes with better numeric stability than Horner's method.
         """
         # Evaluate x³ -4x² -17x + 60 at x = 5
         # polynomial_eval([1, -4, -17, 60], x=5) → 0
         n = len(coefficients)
         if not n:
             return type(x)(0)
         powers = map(pow, repeat(x), reversed(range(n)))
         return sumprod(coefficients, powers)

     def polynomial_derivative(coefficients):
         """Compute the first derivative of a polynomial.

            f(x)  =  x³ -4x² -17x + 60
            f'(x) = 3x² -8x  -17
         """
         # polynomial_derivative([1, -4, -17, 60]) → [3, -8, -17]
         n = len(coefficients)
         powers = reversed(range(1, n))
         return list(map(mul, coefficients, powers))

     # ==== Number theory ====

     def sieve(n):
         "Primes less than n."
         # sieve(30) → 2 3 5 7 11 13 17 19 23 29
         if n > 2:
             yield 2
         data = bytearray((0, 1)) * (n // 2)
         for p in iter_index(data, 1, start=3, stop=isqrt(n) + 1):
             data[p*p : n : p+p] = bytes(len(range(p*p, n, p+p)))
         yield from iter_index(data, 1, start=3)

     def factor(n):
         "Prime factors of n."
         # factor(99) → 3 3 11
         # factor(1_000_000_000_000_007) → 47 59 360620266859
         # factor(1_000_000_000_000_403) → 1000000000000403
         for prime in sieve(isqrt(n) + 1):
             while not n % prime:
                 yield prime
                 n //= prime
                 if n == 1:
                     return
         if n > 1:
             yield n

     def is_prime(n):
         "Return True if n is prime."
         # is_prime(1_000_000_000_000_403) → True
         return n > 1 and next(factor(n)) == n

     def totient(n):
         "Count of natural numbers up to n that are coprime to n."
         # https://mathworld.wolfram.com/TotientFunction.html
         # totient(12) → 4 because len([1, 5, 7, 11]) == 4
         for prime in set(factor(n)):
             n -= n // prime
         return n

   ---------- Footnotes ----------

   (1) https://pypi.org/project/more-itertools/

   (2) https://www.cs.kent.ac.uk/people/staff/dat/miranda/whyfp90.pdf


File: python.info,  Node: functools — Higher-order functions and operations on callable objects,  Next: operator — Standard operators as functions,  Prev: itertools — Functions creating iterators for efficient looping,  Up: Functional Programming Modules

5.10.2 ‘functools’ — Higher-order functions and operations on callable objects
------------------------------------------------------------------------------

'Source code:' Lib/functools.py(1)

__________________________________________________________________

The *note functools: 63. module is for higher-order functions: functions
that act on or return other functions.  In general, any callable object
can be treated as a function for the purposes of this module.

The *note functools: 63. module defines the following functions:

 -- Funzione: @functools.cache (user_function)

     Simple lightweight unbounded function cache.  Sometimes called
     "memoize"(2).

     Returns the same as ‘lru_cache(maxsize=None)’, creating a thin
     wrapper around a dictionary lookup for the function arguments.
     Because it never needs to evict old values, this is smaller and
     faster than *note lru_cache(): be4. with a size limit.

     For example:

          @cache
          def factorial(n):
              return n * factorial(n-1) if n else 1

          >>> factorial(10)   # no previously cached result, makes 11 recursive calls
          3628800
          >>> factorial(5)    # no new calls, just returns the cached result
          120
          >>> factorial(12)   # two new recursive calls, factorial(10) is cached
          479001600

     The cache is threadsafe so that the wrapped function can be used in
     multiple threads.  This means that the underlying data structure
     will remain coherent during concurrent updates.

     It is possible for the wrapped function to be called more than once
     if another thread makes an additional call before the initial call
     has been completed and cached.

     Added in version 3.9.

 -- Funzione: @functools.cached_property (func)

     Transform a method of a class into a property whose value is
     computed once and then cached as a normal attribute for the life of
     the instance.  Similar to *note property(): 4b4, with the addition
     of caching.  Useful for expensive computed properties of instances
     that are otherwise effectively immutable.

     Example:

          class DataSet:

              def __init__(self, sequence_of_numbers):
                  self._data = tuple(sequence_of_numbers)

              @cached_property
              def stdev(self):
                  return statistics.stdev(self._data)

     The mechanics of *note cached_property(): 764. are somewhat
     different from *note property(): 4b4.  A regular property blocks
     attribute writes unless a setter is defined.  In contrast, a
     'cached_property' allows writes.

     The 'cached_property' decorator only runs on lookups and only when
     an attribute of the same name doesn’t exist.  When it does run, the
     'cached_property' writes to the attribute with the same name.
     Subsequent attribute reads and writes take precedence over the
     'cached_property' method and it works like a normal attribute.

     The cached value can be cleared by deleting the attribute.  This
     allows the 'cached_property' method to run again.

     The 'cached_property' does not prevent a possible race condition in
     multi-threaded usage.  The getter function could run more than once
     on the same instance, with the latest run setting the cached value.
     If the cached property is idempotent or otherwise not harmful to
     run more than once on an instance, this is fine.  If
     synchronization is needed, implement the necessary locking inside
     the decorated getter function or around the cached property access.

     Note, this decorator interferes with the operation of PEP 412(3)
     key-sharing dictionaries.  This means that instance dictionaries
     can take more space than usual.

     Also, this decorator requires that the ‘__dict__’ attribute on each
     instance be a mutable mapping.  This means it will not work with
     some types, such as metaclasses (since the ‘__dict__’ attributes on
     type instances are read-only proxies for the class namespace), and
     those that specify ‘__slots__’ without including ‘__dict__’ as one
     of the defined slots (as such classes don’t provide a ‘__dict__’
     attribute at all).

     If a mutable mapping is not available or if space-efficient key
     sharing is desired, an effect similar to *note cached_property():
     764. can also be achieved by stacking *note property(): 4b4. on top
     of *note lru_cache(): be4.  See *note How do I cache method calls?:
     2b95. for more details on how this differs from *note
     cached_property(): 764.

     Added in version 3.8.

     Cambiato nella versione 3.12: Prior to Python 3.12,
     ‘cached_property’ included an undocumented lock to ensure that in
     multi-threaded usage the getter function was guaranteed to run only
     once per instance.  However, the lock was per-property, not
     per-instance, which could result in unacceptably high lock
     contention.  In Python 3.12+ this locking is removed.

 -- Funzione: functools.cmp_to_key (func)

     Transform an old-style comparison function to a *note key function:
     1008.  Used with tools that accept key functions (such as *note
     sorted(): dc9, *note min(): 110d, *note max(): 110e, *note
     heapq.nlargest(): 2989, *note heapq.nsmallest(): 298a, *note
     itertools.groupby(): 2b8b.).  This function is primarily used as a
     transition tool for programs being converted from Python 2 which
     supported the use of comparison functions.

     A comparison function is any callable that accepts two arguments,
     compares them, and returns a negative number for less-than, zero
     for equality, or a positive number for greater-than.  A key
     function is a callable that accepts one argument and returns
     another value to be used as the sort key.

     Example:

          sorted(iterable, key=cmp_to_key(locale.strcoll))  # locale-aware sort order

     For sorting examples and a brief sorting tutorial, see *note
     Sorting Techniques: 25bb.

     Added in version 3.2.

 -- Funzione: @functools.lru_cache (user_function)

 -- Funzione: @functools.lru_cache (maxsize=128, typed=False)

     Decorator to wrap a function with a memoizing callable that saves
     up to the 'maxsize' most recent calls.  It can save time when an
     expensive or I/O bound function is periodically called with the
     same arguments.

     The cache is threadsafe so that the wrapped function can be used in
     multiple threads.  This means that the underlying data structure
     will remain coherent during concurrent updates.

     It is possible for the wrapped function to be called more than once
     if another thread makes an additional call before the initial call
     has been completed and cached.

     Since a dictionary is used to cache results, the positional and
     keyword arguments to the function must be *note hashable: 825.

     Distinct argument patterns may be considered to be distinct calls
     with separate cache entries.  For example, ‘f(a=1, b=2)’ and
     ‘f(b=2, a=1)’ differ in their keyword argument order and may have
     two separate cache entries.

     If 'user_function' is specified, it must be a callable.  This
     allows the 'lru_cache' decorator to be applied directly to a user
     function, leaving the 'maxsize' at its default value of 128:

          @lru_cache
          def count_vowels(sentence):
              return sum(sentence.count(vowel) for vowel in 'AEIOUaeiou')

     If 'maxsize' is set to ‘None’, the LRU feature is disabled and the
     cache can grow without bound.

     If 'typed' is set to true, function arguments of different types
     will be cached separately.  If 'typed' is false, the implementation
     will usually regard them as equivalent calls and only cache a
     single result.  (Some types such as 'str' and 'int' may be cached
     separately even when 'typed' is false.)

     Note, type specificity applies only to the function’s immediate
     arguments rather than their contents.  The scalar arguments,
     ‘Decimal(42)’ and ‘Fraction(42)’ are be treated as distinct calls
     with distinct results.  In contrast, the tuple arguments
     ‘('answer', Decimal(42))’ and ‘('answer', Fraction(42))’ are
     treated as equivalent.

     The wrapped function is instrumented with a ‘cache_parameters()’
     function that returns a new *note dict: 183. showing the values for
     'maxsize' and 'typed'.  This is for information purposes only.
     Mutating the values has no effect.

     To help measure the effectiveness of the cache and tune the
     'maxsize' parameter, the wrapped function is instrumented with a
     ‘cache_info()’ function that returns a *note named tuple: 85f.
     showing 'hits', 'misses', 'maxsize' and 'currsize'.

     The decorator also provides a ‘cache_clear()’ function for clearing
     or invalidating the cache.

     The original underlying function is accessible through the
     ‘__wrapped__’ attribute.  This is useful for introspection, for
     bypassing the cache, or for rewrapping the function with a
     different cache.

     The cache keeps references to the arguments and return values until
     they age out of the cache or until the cache is cleared.

     If a method is cached, the ‘self’ instance argument is included in
     the cache.  See *note How do I cache method calls?: 2b95.

     An LRU (least recently used) cache(4) works best when the most
     recent calls are the best predictors of upcoming calls (for
     example, the most popular articles on a news server tend to change
     each day).  The cache’s size limit assures that the cache does not
     grow without bound on long-running processes such as web servers.

     In general, the LRU cache should only be used when you want to
     reuse previously computed values.  Accordingly, it doesn’t make
     sense to cache functions with side-effects, functions that need to
     create distinct mutable objects on each call (such as generators
     and async functions), or impure functions such as time() or
     random().

     Example of an LRU cache for static web content:

          @lru_cache(maxsize=32)
          def get_pep(num):
              'Retrieve text of a Python Enhancement Proposal'
              resource = f'https://peps.python.org/pep-{num:04d}'
              try:
                  with urllib.request.urlopen(resource) as s:
                      return s.read()
              except urllib.error.HTTPError:
                  return 'Not Found'

          >>> for n in 8, 290, 308, 320, 8, 218, 320, 279, 289, 320, 9991:
          ...     pep = get_pep(n)
          ...     print(n, len(pep))

          >>> get_pep.cache_info()
          CacheInfo(hits=3, misses=8, maxsize=32, currsize=8)

     Example of efficiently computing Fibonacci numbers(5) using a cache
     to implement a dynamic programming(6) technique:

          @lru_cache(maxsize=None)
          def fib(n):
              if n < 2:
                  return n
              return fib(n-1) + fib(n-2)

          >>> [fib(n) for n in range(16)]
          [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610]

          >>> fib.cache_info()
          CacheInfo(hits=28, misses=16, maxsize=None, currsize=16)

     Added in version 3.2.

     Cambiato nella versione 3.3: Added the 'typed' option.

     Cambiato nella versione 3.8: Added the 'user_function' option.

     Cambiato nella versione 3.9: Added the function
     ‘cache_parameters()’

 -- Funzione: @functools.total_ordering

     Given a class defining one or more rich comparison ordering
     methods, this class decorator supplies the rest.  This simplifies
     the effort involved in specifying all of the possible rich
     comparison operations:

     The class must define one of *note __lt__(): 14a8, *note __le__():
     1512, *note __gt__(): 1513, or *note __ge__(): 1514.  In addition,
     the class should supply an *note __eq__(): cf4. method.

     For example:

          @total_ordering
          class Student:
              def _is_valid_operand(self, other):
                  return (hasattr(other, "lastname") and
                          hasattr(other, "firstname"))
              def __eq__(self, other):
                  if not self._is_valid_operand(other):
                      return NotImplemented
                  return ((self.lastname.lower(), self.firstname.lower()) ==
                          (other.lastname.lower(), other.firstname.lower()))
              def __lt__(self, other):
                  if not self._is_valid_operand(other):
                      return NotImplemented
                  return ((self.lastname.lower(), self.firstname.lower()) <
                          (other.lastname.lower(), other.firstname.lower()))

          Nota: While this decorator makes it easy to create well
          behaved totally ordered types, it 'does' come at the cost of
          slower execution and more complex stack traces for the derived
          comparison methods.  If performance benchmarking indicates
          this is a bottleneck for a given application, implementing all
          six rich comparison methods instead is likely to provide an
          easy speed boost.

          Nota: This decorator makes no attempt to override methods that
          have been declared in the class 'or its superclasses'.
          Meaning that if a superclass defines a comparison operator,
          'total_ordering' will not implement it again, even if the
          original method is abstract.

     Added in version 3.2.

     Cambiato nella versione 3.4: Returning ‘NotImplemented’ from the
     underlying comparison function for unrecognised types is now
     supported.

 -- Dati: functools.Placeholder

     A singleton object used as a sentinel to reserve a place for
     positional arguments when calling *note partial(): 217. and *note
     partialmethod(): 218.

     Added in version 3.14.

 -- Funzione: functools.partial (func, /, *args, **keywords)

     Return a new *note partial object: 219. which when called will
     behave like 'func' called with the positional arguments 'args' and
     keyword arguments 'keywords'.  If more arguments are supplied to
     the call, they are appended to 'args'.  If additional keyword
     arguments are supplied, they extend and override 'keywords'.
     Roughly equivalent to:

          def partial(func, /, *args, **keywords):
              def newfunc(*more_args, **more_keywords):
                  return func(*args, *more_args, **(keywords | more_keywords))
              newfunc.func = func
              newfunc.args = args
              newfunc.keywords = keywords
              return newfunc

     The ‘partial()’ function is used for partial function application
     which «freezes» some portion of a function’s arguments and/or
     keywords resulting in a new object with a simplified signature.
     For example, *note partial(): 217. can be used to create a callable
     that behaves like the *note int(): 19b. function where the 'base'
     argument defaults to ‘2’:

          >>> basetwo = partial(int, base=2)
          >>> basetwo.__doc__ = 'Convert base 2 string to an int.'
          >>> basetwo('10010')
          18

     If *note Placeholder: 216. sentinels are present in 'args', they
     will be filled first when ‘partial()’ is called.  This makes it
     possible to pre-fill any positional argument with a call to
     ‘partial()’; without ‘Placeholder’, only the chosen number of
     leading positional arguments can be pre-filled.

     If any ‘Placeholder’ sentinels are present, all must be filled at
     call time:

          >>> say_to_world = partial(print, Placeholder, Placeholder, "world!")
          >>> say_to_world('Hello', 'dear')
          Hello dear world!

     Calling ‘say_to_world('Hello')’ raises a *note TypeError: 198,
     because only one positional argument is provided, but there are two
     placeholders that must be filled in.

     If ‘partial()’ is applied to an existing ‘partial()’ object,
     ‘Placeholder’ sentinels of the input object are filled in with new
     positional arguments.  A placeholder can be retained by inserting a
     new ‘Placeholder’ sentinel to the place held by a previous
     ‘Placeholder’:

          >>> from functools import partial, Placeholder as _
          >>> remove = partial(str.replace, _, _, '')
          >>> message = 'Hello, dear dear world!'
          >>> remove(message, ' dear')
          'Hello, world!'
          >>> remove_dear = partial(remove, _, ' dear')
          >>> remove_dear(message)
          'Hello, world!'
          >>> remove_first_dear = partial(remove_dear, _, 1)
          >>> remove_first_dear(message)
          'Hello, dear world!'

     ‘Placeholder’ cannot be passed to ‘partial()’ as a keyword
     argument.

     Cambiato nella versione 3.14: Added support for *note Placeholder:
     216. in positional arguments.

 -- Classe: functools.partialmethod (func, /, *args, **keywords)

     Return a new *note partialmethod: 218. descriptor which behaves
     like *note partial: 217. except that it is designed to be used as a
     method definition rather than being directly callable.

     'func' must be a *note descriptor: 1869. or a callable (objects
     which are both, like normal functions, are handled as descriptors).

     When 'func' is a descriptor (such as a normal Python function,
     *note classmethod(): 48f, *note staticmethod(): 453, *note
     abstractmethod(): 128d. or another instance of *note partialmethod:
     218.), calls to ‘__get__’ are delegated to the underlying
     descriptor, and an appropriate *note partial object: 219. returned
     as the result.

     When 'func' is a non-descriptor callable, an appropriate bound
     method is created dynamically.  This behaves like a normal Python
     function when used as a method: the 'self' argument will be
     inserted as the first positional argument, even before the 'args'
     and 'keywords' supplied to the *note partialmethod: 218.
     constructor.

     Example:

          >>> class Cell:
          ...     def __init__(self):
          ...         self._alive = False
          ...     @property
          ...     def alive(self):
          ...         return self._alive
          ...     def set_state(self, state):
          ...         self._alive = bool(state)
          ...     set_alive = partialmethod(set_state, True)
          ...     set_dead = partialmethod(set_state, False)
          ...
          >>> c = Cell()
          >>> c.alive
          False
          >>> c.set_alive()
          >>> c.alive
          True

     Added in version 3.4.

 -- Funzione: functools.reduce (function, iterable, /[, initial])

     Apply 'function' of two arguments cumulatively to the items of
     'iterable', from left to right, so as to reduce the iterable to a
     single value.  For example, ‘reduce(lambda x, y: x+y, [1, 2, 3, 4,
     5])’ calculates ‘((((1+2)+3)+4)+5)’.  The left argument, 'x', is
     the accumulated value and the right argument, 'y', is the update
     value from the 'iterable'.  If the optional 'initial' is present,
     it is placed before the items of the iterable in the calculation,
     and serves as a default when the iterable is empty.  If 'initial'
     is not given and 'iterable' contains only one item, the first item
     is returned.

     Roughly equivalent to:

          initial_missing = object()

          def reduce(function, iterable, /, initial=initial_missing):
              it = iter(iterable)
              if initial is initial_missing:
                  value = next(it)
              else:
                  value = initial
              for element in it:
                  value = function(value, element)
              return value

     See *note itertools.accumulate(): bf2. for an iterator that yields
     all intermediate values.

     Cambiato nella versione 3.14: 'initial' is now supported as a
     keyword argument.

 -- Funzione: @functools.singledispatch

     Transform a function into a *note single-dispatch: be7. *note
     generic function: be6.

     To define a generic function, decorate it with the
     ‘@singledispatch’ decorator.  When defining a function using
     ‘@singledispatch’, note that the dispatch happens on the type of
     the first argument:

          >>> from functools import singledispatch
          >>> @singledispatch
          ... def fun(arg, verbose=False):
          ...     if verbose:
          ...         print("Let me just say,", end=" ")
          ...     print(arg)

     To add overloaded implementations to the function, use the
     ‘register()’ attribute of the generic function, which can be used
     as a decorator.  For functions annotated with types, the decorator
     will infer the type of the first argument automatically:

          >>> @fun.register
          ... def _(arg: int, verbose=False):
          ...     if verbose:
          ...         print("Strength in numbers, eh?", end=" ")
          ...     print(arg)
          ...
          >>> @fun.register
          ... def _(arg: list, verbose=False):
          ...     if verbose:
          ...         print("Enumerate this:")
          ...     for i, elem in enumerate(arg):
          ...         print(i, elem)

     *note typing.Union: 2a8. can also be used:

          >>> @fun.register
          ... def _(arg: int | float, verbose=False):
          ...     if verbose:
          ...         print("Strength in numbers, eh?", end=" ")
          ...     print(arg)
          ...
          >>> from typing import Union
          >>> @fun.register
          ... def _(arg: Union[list, set], verbose=False):
          ...     if verbose:
          ...         print("Enumerate this:")
          ...     for i, elem in enumerate(arg):
          ...         print(i, elem)
          ...

     For code which doesn’t use type annotations, the appropriate type
     argument can be passed explicitly to the decorator itself:

          >>> @fun.register(complex)
          ... def _(arg, verbose=False):
          ...     if verbose:
          ...         print("Better than complicated.", end=" ")
          ...     print(arg.real, arg.imag)
          ...

     For code that dispatches on a collections type (e.g., ‘list’), but
     wants to typehint the items of the collection (e.g., ‘list[int]’),
     the dispatch type should be passed explicitly to the decorator
     itself with the typehint going into the function definition:

          >>> @fun.register(list)
          ... def _(arg: list[int], verbose=False):
          ...     if verbose:
          ...         print("Enumerate this:")
          ...     for i, elem in enumerate(arg):
          ...         print(i, elem)

          Nota: At runtime the function will dispatch on an instance of
          a list regardless of the type contained within the list i.e.
          ‘[1,2,3]’ will be dispatched the same as ‘["foo", "bar",
          "baz"]’.  The annotation provided in this example is for
          static type checkers only and has no runtime impact.

     To enable registering *note lambdas: 2b99. and pre-existing
     functions, the *note register(): 2b98. attribute can also be used
     in a functional form:

          >>> def nothing(arg, verbose=False):
          ...     print("Nothing.")
          ...
          >>> fun.register(type(None), nothing)

     The *note register(): 2b98. attribute returns the undecorated
     function.  This enables decorator stacking, *note pickling: ab, and
     the creation of unit tests for each variant independently:

          >>> @fun.register(float)
          ... @fun.register(Decimal)
          ... def fun_num(arg, verbose=False):
          ...     if verbose:
          ...         print("Half of your number:", end=" ")
          ...     print(arg / 2)
          ...
          >>> fun_num is fun
          False

     When called, the generic function dispatches on the type of the
     first argument:

          >>> fun("Hello, world.")
          Hello, world.
          >>> fun("test.", verbose=True)
          Let me just say, test.
          >>> fun(42, verbose=True)
          Strength in numbers, eh? 42
          >>> fun(['spam', 'spam', 'eggs', 'spam'], verbose=True)
          Enumerate this:
          0 spam
          1 spam
          2 eggs
          3 spam
          >>> fun(None)
          Nothing.
          >>> fun(1.23)
          0.615

     Where there is no registered implementation for a specific type,
     its method resolution order is used to find a more generic
     implementation.  The original function decorated with
     ‘@singledispatch’ is registered for the base *note object: c80.
     type, which means it is used if no better implementation is found.

     If an implementation is registered to an *note abstract base class:
     13be, virtual subclasses of the base class will be dispatched to
     that implementation:

          >>> from collections.abc import Mapping
          >>> @fun.register
          ... def _(arg: Mapping, verbose=False):
          ...     if verbose:
          ...         print("Keys & Values")
          ...     for key, value in arg.items():
          ...         print(key, "=>", value)
          ...
          >>> fun({"a": "b"})
          a => b

     To check which implementation the generic function will choose for
     a given type, use the ‘dispatch()’ attribute:

          >>> fun.dispatch(float)
          <function fun_num at 0x1035a2840>
          >>> fun.dispatch(dict)    # note: default implementation
          <function fun at 0x103fe0000>

     To access all registered implementations, use the read-only
     ‘registry’ attribute:

          >>> fun.registry.keys()
          dict_keys([<class 'NoneType'>, <class 'int'>, <class 'object'>,
                    <class 'decimal.Decimal'>, <class 'list'>,
                    <class 'float'>])
          >>> fun.registry[float]
          <function fun_num at 0x1035a2840>
          >>> fun.registry[object]
          <function fun at 0x103fe0000>

     Added in version 3.4.

     Cambiato nella versione 3.7: The *note register(): 2b98. attribute
     now supports using type annotations.

     Cambiato nella versione 3.11: The *note register(): 2b98. attribute
     now supports *note typing.Union: 2a8. as a type annotation.

 -- Classe: functools.singledispatchmethod (func)

     Transform a method into a *note single-dispatch: be7. *note generic
     function: be6.

     To define a generic method, decorate it with the
     ‘@singledispatchmethod’ decorator.  When defining a method using
     ‘@singledispatchmethod’, note that the dispatch happens on the type
     of the first non-'self' or non-'cls' argument:

          class Negator:
              @singledispatchmethod
              def neg(self, arg):
                  raise NotImplementedError("Cannot negate a")

              @neg.register
              def _(self, arg: int):
                  return -arg

              @neg.register
              def _(self, arg: bool):
                  return not arg

     ‘@singledispatchmethod’ supports nesting with other decorators such
     as *note @classmethod: 48f.  Note that to allow for
     ‘dispatcher.register’, ‘singledispatchmethod’ must be the 'outer
     most' decorator.  Here is the ‘Negator’ class with the ‘neg’
     methods bound to the class, rather than an instance of the class:

          class Negator:
              @singledispatchmethod
              @classmethod
              def neg(cls, arg):
                  raise NotImplementedError("Cannot negate a")

              @neg.register
              @classmethod
              def _(cls, arg: int):
                  return -arg

              @neg.register
              @classmethod
              def _(cls, arg: bool):
                  return not arg

     The same pattern can be used for other similar decorators: *note
     @staticmethod: 453, *note @~abc.abstractmethod: 128d, and others.

     Added in version 3.8.

 -- Funzione: functools.update_wrapper (wrapper, wrapped,
          assigned=WRAPPER_ASSIGNMENTS, updated=WRAPPER_UPDATES)

     Update a 'wrapper' function to look like the 'wrapped' function.
     The optional arguments are tuples to specify which attributes of
     the original function are assigned directly to the matching
     attributes on the wrapper function and which attributes of the
     wrapper function are updated with the corresponding attributes from
     the original function.  The default values for these arguments are
     the module level constants ‘WRAPPER_ASSIGNMENTS’ (which assigns to
     the wrapper function’s *note __module__: 2331, *note __name__:
     14dc, *note __qualname__: 2330, *note __annotations__: 13e0, *note
     __type_params__: 2334, and *note __doc__: 13e1, the documentation
     string) and ‘WRAPPER_UPDATES’ (which updates the wrapper function’s
     *note __dict__: 14da, i.e.  the instance dictionary).

     To allow access to the original function for introspection and
     other purposes (e.g.  bypassing a caching decorator such as *note
     lru_cache(): be4.), this function automatically adds a
     ‘__wrapped__’ attribute to the wrapper that refers to the function
     being wrapped.

     The main intended use for this function is in *note decorator: 93b.
     functions which wrap the decorated function and return the wrapper.
     If the wrapper function is not updated, the metadata of the
     returned function will reflect the wrapper definition rather than
     the original function definition, which is typically less than
     helpful.

     *note update_wrapper(): 1224. may be used with callables other than
     functions.  Any attributes named in 'assigned' or 'updated' that
     are missing from the object being wrapped are ignored (i.e.  this
     function will not attempt to set them on the wrapper function).
     *note AttributeError: 5f0. is still raised if the wrapper function
     itself is missing any attributes named in 'updated'.

     Cambiato nella versione 3.2: The ‘__wrapped__’ attribute is now
     automatically added.  The *note __annotations__: 13e0. attribute is
     now copied by default.  Missing attributes no longer trigger an
     *note AttributeError: 5f0.

     Cambiato nella versione 3.4: The ‘__wrapped__’ attribute now always
     refers to the wrapped function, even if that function defined a
     ‘__wrapped__’ attribute.  (see bpo-17482(7))

     Cambiato nella versione 3.12: The *note __type_params__: 2334.
     attribute is now copied by default.

 -- Funzione: @functools.wraps (wrapped, assigned=WRAPPER_ASSIGNMENTS,
          updated=WRAPPER_UPDATES)

     This is a convenience function for invoking *note update_wrapper():
     1224. as a function decorator when defining a wrapper function.  It
     is equivalent to ‘partial(update_wrapper, wrapped=wrapped,
     assigned=assigned, updated=updated)’.  For example:

          >>> from functools import wraps
          >>> def my_decorator(f):
          ...     @wraps(f)
          ...     def wrapper(*args, **kwds):
          ...         print('Calling decorated function')
          ...         return f(*args, **kwds)
          ...     return wrapper
          ...
          >>> @my_decorator
          ... def example():
          ...     """Docstring"""
          ...     print('Called example function')
          ...
          >>> example()
          Calling decorated function
          Called example function
          >>> example.__name__
          'example'
          >>> example.__doc__
          'Docstring'

     Without the use of this decorator factory, the name of the example
     function would have been ‘'wrapper'’, and the docstring of the
     original ‘example()’ would have been lost.

* Menu:

* partial Objects::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/functools.py

   (2) https://en.wikipedia.org/wiki/Memoization

   (3) https://peps.python.org/pep-0412/

   (4) 
https://en.wikipedia.org/wiki/Cache_replacement_policies#Least_Recently_Used_(LRU)

   (5) https://en.wikipedia.org/wiki/Fibonacci_number

   (6) https://en.wikipedia.org/wiki/Dynamic_programming

   (7) https://bugs.python.org/issue?@action=redirect&bpo=17482


File: python.info,  Node: partial Objects,  Up: functools — Higher-order functions and operations on callable objects

5.10.2.1 ‘partial’ Objects
..........................

*note partial: 217. objects are callable objects created by *note
partial(): 217.  They have three read-only attributes:

 -- Attributo: partial.func

     A callable object or function.  Calls to the *note partial: 217.
     object will be forwarded to *note func: 2b9b. with new arguments
     and keywords.

 -- Attributo: partial.args

     The leftmost positional arguments that will be prepended to the
     positional arguments provided to a *note partial: 217. object call.

 -- Attributo: partial.keywords

     The keyword arguments that will be supplied when the *note partial:
     217. object is called.

*note partial: 217. objects are like *note function objects: 59c. in
that they are callable, weak referenceable, and can have attributes.
There are some important differences.  For instance, the *note __name__:
1268. and *note __doc__: b23. attributes are not created automatically.


File: python.info,  Node: operator — Standard operators as functions,  Prev: functools — Higher-order functions and operations on callable objects,  Up: Functional Programming Modules

5.10.3 ‘operator’ — Standard operators as functions
---------------------------------------------------

'Source code:' Lib/operator.py(1)

__________________________________________________________________

The *note operator: a3. module exports a set of efficient functions
corresponding to the intrinsic operators of Python.  For example,
‘operator.add(x, y)’ is equivalent to the expression ‘x+y’.  Many
function names are those used for special methods, without the double
underscores.  For backward compatibility, many of these have a variant
with the double underscores kept.  The variants without the double
underscores are preferred for clarity.

The functions fall into categories that perform object comparisons,
logical operations, mathematical operations and sequence operations.

The object comparison functions are useful for all objects, and are
named after the rich comparison operators they support:

 -- Funzione: operator.lt (a, b)
 -- Funzione: operator.le (a, b)
 -- Funzione: operator.eq (a, b)
 -- Funzione: operator.ne (a, b)
 -- Funzione: operator.ge (a, b)
 -- Funzione: operator.gt (a, b)
 -- Funzione: operator.__lt__ (a, b)
 -- Funzione: operator.__le__ (a, b)
 -- Funzione: operator.__eq__ (a, b)
 -- Funzione: operator.__ne__ (a, b)
 -- Funzione: operator.__ge__ (a, b)
 -- Funzione: operator.__gt__ (a, b)

     Perform «rich comparisons» between 'a' and 'b'.  Specifically,
     ‘lt(a, b)’ is equivalent to ‘a < b’, ‘le(a, b)’ is equivalent to ‘a
     <= b’, ‘eq(a, b)’ is equivalent to ‘a == b’, ‘ne(a, b)’ is
     equivalent to ‘a != b’, ‘gt(a, b)’ is equivalent to ‘a > b’ and
     ‘ge(a, b)’ is equivalent to ‘a >= b’.  Note that these functions
     can return any value, which may or may not be interpretable as a
     Boolean value.  See *note Comparisons: 24ac. for more information
     about rich comparisons.

The logical operations are also generally applicable to all objects, and
support truth tests, identity tests, and boolean operations:

 -- Funzione: operator.not_ (obj)
 -- Funzione: operator.__not__ (obj)

     Return the outcome of *note not: 24b6. 'obj'.  (Note that there is
     no ‘__not__()’ method for object instances; only the interpreter
     core defines this operation.  The result is affected by the *note
     __bool__(): 14dd. and *note __len__(): 1777. methods.)

 -- Funzione: operator.truth (obj)

     Return *note True: e09. if 'obj' is true, and *note False: d2d.
     otherwise.  This is equivalent to using the *note bool: 3c3.
     constructor.

 -- Funzione: operator.is_ (a, b)

     Return ‘a is b’.  Tests object identity.

 -- Funzione: operator.is_not (a, b)

     Return ‘a is not b’.  Tests object identity.

 -- Funzione: operator.is_none (a)

     Return ‘a is None’.  Tests object identity.

     Added in version 3.14.

 -- Funzione: operator.is_not_none (a)

     Return ‘a is not None’.  Tests object identity.

     Added in version 3.14.

The mathematical and bitwise operations are the most numerous:

 -- Funzione: operator.abs (obj)
 -- Funzione: operator.__abs__ (obj)

     Return the absolute value of 'obj'.

 -- Funzione: operator.add (a, b)
 -- Funzione: operator.__add__ (a, b)

     Return ‘a + b’, for 'a' and 'b' numbers.

 -- Funzione: operator.and_ (a, b)
 -- Funzione: operator.__and__ (a, b)

     Return the bitwise and of 'a' and 'b'.

 -- Funzione: operator.floordiv (a, b)
 -- Funzione: operator.__floordiv__ (a, b)

     Return ‘a // b’.

 -- Funzione: operator.index (a)
 -- Funzione: operator.__index__ (a)

     Return 'a' converted to an integer.  Equivalent to ‘a.__index__()’.

     Cambiato nella versione 3.10: The result always has exact type
     *note int: 19b.  Previously, the result could have been an instance
     of a subclass of ‘int’.

 -- Funzione: operator.inv (obj)
 -- Funzione: operator.invert (obj)
 -- Funzione: operator.__inv__ (obj)
 -- Funzione: operator.__invert__ (obj)

     Return the bitwise inverse of the number 'obj'.  This is equivalent
     to ‘~obj’.

 -- Funzione: operator.lshift (a, b)
 -- Funzione: operator.__lshift__ (a, b)

     Return 'a' shifted left by 'b'.

 -- Funzione: operator.mod (a, b)
 -- Funzione: operator.__mod__ (a, b)

     Return ‘a % b’.

 -- Funzione: operator.mul (a, b)
 -- Funzione: operator.__mul__ (a, b)

     Return ‘a * b’, for 'a' and 'b' numbers.

 -- Funzione: operator.matmul (a, b)
 -- Funzione: operator.__matmul__ (a, b)

     Return ‘a @ b’.

     Added in version 3.5.

 -- Funzione: operator.neg (obj)
 -- Funzione: operator.__neg__ (obj)

     Return 'obj' negated (‘-obj’).

 -- Funzione: operator.or_ (a, b)
 -- Funzione: operator.__or__ (a, b)

     Return the bitwise or of 'a' and 'b'.

 -- Funzione: operator.pos (obj)
 -- Funzione: operator.__pos__ (obj)

     Return 'obj' positive (‘+obj’).

 -- Funzione: operator.pow (a, b)
 -- Funzione: operator.__pow__ (a, b)

     Return ‘a ** b’, for 'a' and 'b' numbers.

 -- Funzione: operator.rshift (a, b)
 -- Funzione: operator.__rshift__ (a, b)

     Return 'a' shifted right by 'b'.

 -- Funzione: operator.sub (a, b)
 -- Funzione: operator.__sub__ (a, b)

     Return ‘a - b’.

 -- Funzione: operator.truediv (a, b)
 -- Funzione: operator.__truediv__ (a, b)

     Return ‘a / b’ where 2/3 is .66 rather than 0.  This is also known
     as «true» division.

 -- Funzione: operator.xor (a, b)
 -- Funzione: operator.__xor__ (a, b)

     Return the bitwise exclusive or of 'a' and 'b'.

Operations which work with sequences (some of them with mappings too)
include:

 -- Funzione: operator.concat (a, b)
 -- Funzione: operator.__concat__ (a, b)

     Return ‘a + b’ for 'a' and 'b' sequences.

 -- Funzione: operator.contains (a, b)
 -- Funzione: operator.__contains__ (a, b)

     Return the outcome of the test ‘b in a’.  Note the reversed
     operands.

 -- Funzione: operator.countOf (a, b)

     Return the number of occurrences of 'b' in 'a'.

 -- Funzione: operator.delitem (a, b)
 -- Funzione: operator.__delitem__ (a, b)

     Remove the value of 'a' at index 'b'.

 -- Funzione: operator.getitem (a, b)
 -- Funzione: operator.__getitem__ (a, b)

     Return the value of 'a' at index 'b'.

 -- Funzione: operator.indexOf (a, b)

     Return the index of the first of occurrence of 'b' in 'a'.

 -- Funzione: operator.setitem (a, b, c)
 -- Funzione: operator.__setitem__ (a, b, c)

     Set the value of 'a' at index 'b' to 'c'.

 -- Funzione: operator.length_hint (obj, default=0)

     Return an estimated length for the object 'obj'.  First try to
     return its actual length, then an estimate using *note
     object.__length_hint__(): 1110, and finally return the default
     value.

     Added in version 3.4.

The following operation works with callables:

 -- Funzione: operator.call (obj, /, *args, **kwargs)
 -- Funzione: operator.__call__ (obj, /, *args, **kwargs)

     Return ‘obj(*args, **kwargs)’.

     Added in version 3.11.

The *note operator: a3. module also defines tools for generalized
attribute and item lookups.  These are useful for making fast field
extractors as arguments for *note map(): 19f, *note sorted(): dc9, *note
itertools.groupby(): 2b8b, or other functions that expect a function
argument.

 -- Funzione: operator.attrgetter (attr)

 -- Funzione: operator.attrgetter (*attrs)

     Return a callable object that fetches 'attr' from its operand.  If
     more than one attribute is requested, returns a tuple of
     attributes.  The attribute names can also contain dots.  For
     example:

        * After ‘f = attrgetter('name')’, the call ‘f(b)’ returns
          ‘b.name’.

        * After ‘f = attrgetter('name', 'date')’, the call ‘f(b)’
          returns ‘(b.name, b.date)’.

        * After ‘f = attrgetter('name.first', 'name.last')’, the call
          ‘f(b)’ returns ‘(b.name.first, b.name.last)’.

     Equivalent to:

          def attrgetter(*items):
              if any(not isinstance(item, str) for item in items):
                  raise TypeError('attribute name must be a string')
              if len(items) == 1:
                  attr = items[0]
                  def g(obj):
                      return resolve_attr(obj, attr)
              else:
                  def g(obj):
                      return tuple(resolve_attr(obj, attr) for attr in items)
              return g

          def resolve_attr(obj, attr):
              for name in attr.split("."):
                  obj = getattr(obj, name)
              return obj

 -- Funzione: operator.itemgetter (item)

 -- Funzione: operator.itemgetter (*items)

     Return a callable object that fetches 'item' from its operand using
     the operand’s *note __getitem__(): 588. method.  If multiple items
     are specified, returns a tuple of lookup values.  For example:

        * After ‘f = itemgetter(2)’, the call ‘f(r)’ returns ‘r[2]’.

        * After ‘g = itemgetter(2, 5, 3)’, the call ‘g(r)’ returns
          ‘(r[2], r[5], r[3])’.

     Equivalent to:

          def itemgetter(*items):
              if len(items) == 1:
                  item = items[0]
                  def g(obj):
                      return obj[item]
              else:
                  def g(obj):
                      return tuple(obj[item] for item in items)
              return g

     The items can be any type accepted by the operand’s *note
     __getitem__(): 588. method.  Dictionaries accept any *note
     hashable: 825. value.  Lists, tuples, and strings accept an index
     or a slice:

          >>> itemgetter(1)('ABCDEFG')
          'B'
          >>> itemgetter(1, 3, 5)('ABCDEFG')
          ('B', 'D', 'F')
          >>> itemgetter(slice(2, None))('ABCDEFG')
          'CDEFG'
          >>> soldier = dict(rank='captain', name='dotterbart')
          >>> itemgetter('rank')(soldier)
          'captain'

     Example of using *note itemgetter(): c59. to retrieve specific
     fields from a tuple record:

          >>> inventory = [('apple', 3), ('banana', 2), ('pear', 5), ('orange', 1)]
          >>> getcount = itemgetter(1)
          >>> list(map(getcount, inventory))
          [3, 2, 5, 1]
          >>> sorted(inventory, key=getcount)
          [('orange', 1), ('banana', 2), ('apple', 3), ('pear', 5)]

 -- Funzione: operator.methodcaller (name, /, *args, **kwargs)

     Return a callable object that calls the method 'name' on its
     operand.  If additional arguments and/or keyword arguments are
     given, they will be given to the method as well.  For example:

        * After ‘f = methodcaller('name')’, the call ‘f(b)’ returns
          ‘b.name()’.

        * After ‘f = methodcaller('name', 'foo', bar=1)’, the call
          ‘f(b)’ returns ‘b.name('foo', bar=1)’.

     Equivalent to:

          def methodcaller(name, /, *args, **kwargs):
              def caller(obj):
                  return getattr(obj, name)(*args, **kwargs)
              return caller

* Menu:

* Mapping Operators to Functions::
* In-place Operators::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/operator.py


File: python.info,  Node: Mapping Operators to Functions,  Next: In-place Operators,  Up: operator — Standard operators as functions

5.10.3.1 Mapping Operators to Functions
.......................................

This table shows how abstract operations correspond to operator symbols
in the Python syntax and the functions in the *note operator: a3.
module.

Operation                   Syntax                        Function
                                                          
------------------------------------------------------------------------------------------------------
                                                          
Addition                    ‘a + b’                       ‘add(a, b)’
                                                          
                                                          
Concatenation               ‘seq1 + seq2’                 ‘concat(seq1, seq2)’
                                                          
                                                          
Containment Test            ‘obj in seq’                  ‘contains(seq, obj)’
                                                          
                                                          
Division                    ‘a / b’                       ‘truediv(a, b)’
                                                          
                                                          
Division                    ‘a // b’                      ‘floordiv(a, b)’
                                                          
                                                          
Bitwise And                 ‘a & b’                       ‘and_(a, b)’
                                                          
                                                          
Bitwise Exclusive Or        ‘a ^ b’                       ‘xor(a, b)’
                                                          
                                                          
Bitwise Inversion           ‘~ a’                         ‘invert(a)’
                                                          
                                                          
Bitwise Or                  ‘a | b’                       ‘or_(a, b)’
                                                          
                                                          
Exponentiation              ‘a ** b’                      ‘pow(a, b)’
                                                          
                                                          
Identity                    ‘a is b’                      ‘is_(a, b)’
                                                          
                                                          
Identity                    ‘a is not b’                  ‘is_not(a, b)’
                                                          
                                                          
Identity                    ‘a is None’                   ‘is_none(a)’
                                                          
                                                          
Identity                    ‘a is not None’               ‘is_not_none(a)’
                                                          
                                                          
Indexed Assignment          ‘obj[k] = v’                  ‘setitem(obj, k, v)’
                                                          
                                                          
Indexed Deletion            ‘del obj[k]’                  ‘delitem(obj, k)’
                                                          
                                                          
Indexing                    ‘obj[k]’                      ‘getitem(obj, k)’
                                                          
                                                          
Left Shift                  ‘a << b’                      ‘lshift(a, b)’
                                                          
                                                          
Modulo                      ‘a % b’                       ‘mod(a, b)’
                                                          
                                                          
Multiplication              ‘a * b’                       ‘mul(a, b)’
                                                          
                                                          
Matrix Multiplication       ‘a @ b’                       ‘matmul(a, b)’
                                                          
                                                          
Negation (Arithmetic)       ‘- a’                         ‘neg(a)’
                                                          
                                                          
Negation (Logical)          ‘not a’                       ‘not_(a)’
                                                          
                                                          
Positive                    ‘+ a’                         ‘pos(a)’
                                                          
                                                          
Right Shift                 ‘a >> b’                      ‘rshift(a, b)’
                                                          
                                                          
Slice Assignment            ‘seq[i:j] = values’           ‘setitem(seq, slice(i, j), values)’
                                                          
                                                          
Slice Deletion              ‘del seq[i:j]’                ‘delitem(seq, slice(i, j))’
                                                          
                                                          
Slicing                     ‘seq[i:j]’                    ‘getitem(seq, slice(i, j))’
                                                          
                                                          
String Formatting           ‘s % obj’                     ‘mod(s, obj)’
                                                          
                                                          
Subtraction                 ‘a - b’                       ‘sub(a, b)’
                                                          
                                                          
Truth Test                  ‘obj’                         ‘truth(obj)’
                                                          
                                                          
Ordering                    ‘a < b’                       ‘lt(a, b)’
                                                          
                                                          
Ordering                    ‘a <= b’                      ‘le(a, b)’
                                                          
                                                          
Equality                    ‘a == b’                      ‘eq(a, b)’
                                                          
                                                          
Difference                  ‘a != b’                      ‘ne(a, b)’
                                                          
                                                          
Ordering                    ‘a >= b’                      ‘ge(a, b)’
                                                          
                                                          
Ordering                    ‘a > b’                       ‘gt(a, b)’
                                                          


File: python.info,  Node: In-place Operators,  Prev: Mapping Operators to Functions,  Up: operator — Standard operators as functions

5.10.3.2 In-place Operators
...........................

Many operations have an «in-place» version.  Listed below are functions
providing a more primitive access to in-place operators than the usual
syntax does; for example, the *note statement: 2be2. ‘x += y’ is
equivalent to ‘x = operator.iadd(x, y)’.  Another way to put it is to
say that ‘z = operator.iadd(x, y)’ is equivalent to the compound
statement ‘z = x; z += y’.

In those examples, note that when an in-place method is called, the
computation and assignment are performed in two separate steps.  The
in-place functions listed below only do the first step, calling the
in-place method.  The second step, assignment, is not handled.

For immutable targets such as strings, numbers, and tuples, the updated
value is computed, but not assigned back to the input variable:

     >>> a = 'hello'
     >>> iadd(a, ' world')
     'hello world'
     >>> a
     'hello'

For mutable targets such as lists and dictionaries, the in-place method
will perform the update, so no subsequent assignment is necessary:

     >>> s = ['h', 'e', 'l', 'l', 'o']
     >>> iadd(s, [' ', 'w', 'o', 'r', 'l', 'd'])
     ['h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd']
     >>> s
     ['h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd']

 -- Funzione: operator.iadd (a, b)
 -- Funzione: operator.__iadd__ (a, b)

     ‘a = iadd(a, b)’ is equivalent to ‘a += b’.

 -- Funzione: operator.iand (a, b)
 -- Funzione: operator.__iand__ (a, b)

     ‘a = iand(a, b)’ is equivalent to ‘a &= b’.

 -- Funzione: operator.iconcat (a, b)
 -- Funzione: operator.__iconcat__ (a, b)

     ‘a = iconcat(a, b)’ is equivalent to ‘a += b’ for 'a' and 'b'
     sequences.

 -- Funzione: operator.ifloordiv (a, b)
 -- Funzione: operator.__ifloordiv__ (a, b)

     ‘a = ifloordiv(a, b)’ is equivalent to ‘a //= b’.

 -- Funzione: operator.ilshift (a, b)
 -- Funzione: operator.__ilshift__ (a, b)

     ‘a = ilshift(a, b)’ is equivalent to ‘a <<= b’.

 -- Funzione: operator.imod (a, b)
 -- Funzione: operator.__imod__ (a, b)

     ‘a = imod(a, b)’ is equivalent to ‘a %= b’.

 -- Funzione: operator.imul (a, b)
 -- Funzione: operator.__imul__ (a, b)

     ‘a = imul(a, b)’ is equivalent to ‘a *= b’.

 -- Funzione: operator.imatmul (a, b)
 -- Funzione: operator.__imatmul__ (a, b)

     ‘a = imatmul(a, b)’ is equivalent to ‘a @= b’.

     Added in version 3.5.

 -- Funzione: operator.ior (a, b)
 -- Funzione: operator.__ior__ (a, b)

     ‘a = ior(a, b)’ is equivalent to ‘a |= b’.

 -- Funzione: operator.ipow (a, b)
 -- Funzione: operator.__ipow__ (a, b)

     ‘a = ipow(a, b)’ is equivalent to ‘a **= b’.

 -- Funzione: operator.irshift (a, b)
 -- Funzione: operator.__irshift__ (a, b)

     ‘a = irshift(a, b)’ is equivalent to ‘a >>= b’.

 -- Funzione: operator.isub (a, b)
 -- Funzione: operator.__isub__ (a, b)

     ‘a = isub(a, b)’ is equivalent to ‘a -= b’.

 -- Funzione: operator.itruediv (a, b)
 -- Funzione: operator.__itruediv__ (a, b)

     ‘a = itruediv(a, b)’ is equivalent to ‘a /= b’.

 -- Funzione: operator.ixor (a, b)
 -- Funzione: operator.__ixor__ (a, b)

     ‘a = ixor(a, b)’ is equivalent to ‘a ^= b’.


File: python.info,  Node: File and Directory Access,  Next: Data Persistence,  Prev: Functional Programming Modules,  Up: The Python Standard Library

5.11 File and Directory Access
==============================

The modules described in this chapter deal with disk files and
directories.  For example, there are modules for reading the properties
of files, manipulating paths in a portable way, and creating temporary
files.  The full list of modules in this chapter is:

* Menu:

* pathlib — Object-oriented filesystem paths::
* os.path — Common pathname manipulations: os path — Common pathname manipulations.
* stat — Interpreting stat() results: stat — Interpreting stat results.
* filecmp — File and Directory Comparisons::
* tempfile — Generate temporary files and directories::
* glob — Unix style pathname pattern expansion::
* fnmatch — Unix filename pattern matching::
* linecache — Random access to text lines::
* shutil — High-level file operations::


File: python.info,  Node: pathlib — Object-oriented filesystem paths,  Next: os path — Common pathname manipulations,  Up: File and Directory Access

5.11.1 ‘pathlib’ — Object-oriented filesystem paths
---------------------------------------------------

Added in version 3.4.

'Source code:' Lib/pathlib/(1)

__________________________________________________________________

This module offers classes representing filesystem paths with semantics
appropriate for different operating systems.  Path classes are divided
between *note pure paths: 2c04, which provide purely computational
operations without I/O, and *note concrete paths: 2c05, which inherit
from pure paths but also provide I/O operations.

[image src="python-figures/pathlib-inheritance.png" alt="Inheritance diagram showing the classes available in pathlib. The most basic class is PurePath, which has three direct subclasses: PurePosixPath, PureWindowsPath, and Path. Further to these four classes, there are two classes that use multiple inheritance: PosixPath subclasses PurePosixPath and Path, and WindowsPath subclasses PureWindowsPath and Path."]


If you’ve never used this module before or just aren’t sure which class
is right for your task, *note Path: 266. is most likely what you need.
It instantiates a *note concrete path: 2c05. for the platform the code
is running on.

Pure paths are useful in some special cases; for example:

  1. If you want to manipulate Windows paths on a Unix machine (or vice
     versa).  You cannot instantiate a *note WindowsPath: 2c06. when
     running on Unix, but you can instantiate *note PureWindowsPath:
     1a5d.

  2. You want to make sure that your code only manipulates paths without
     actually accessing the OS. In this case, instantiating one of the
     pure classes may be useful since those simply don’t have any
     OS-accessing operations.

Vedi anche
..........

PEP 428(2): The pathlib module – object-oriented filesystem paths.

Vedi anche
..........

For low-level path manipulation on strings, you can also use the *note
os.path: a6. module.

* Menu:

* Basic use: Basic use<2>.
* Exceptions: Exceptions<5>.
* Pure paths::
* Concrete paths::
* Pattern language::
* Comparison to the glob module::
* Comparison to the os and os.path modules: Comparison to the os and os path modules.
* Protocols::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/pathlib/

   (2) https://peps.python.org/pep-0428/


File: python.info,  Node: Basic use<2>,  Next: Exceptions<5>,  Up: pathlib — Object-oriented filesystem paths

5.11.1.1 Basic use
..................

Importing the main class:

     >>> from pathlib import Path

Listing subdirectories:

     >>> p = Path('.')
     >>> [x for x in p.iterdir() if x.is_dir()]
     [PosixPath('.hg'), PosixPath('docs'), PosixPath('dist'),
      PosixPath('__pycache__'), PosixPath('build')]

Listing Python source files in this directory tree:

     >>> list(p.glob('**/*.py'))
     [PosixPath('test_pathlib.py'), PosixPath('setup.py'),
      PosixPath('pathlib.py'), PosixPath('docs/conf.py'),
      PosixPath('build/lib/pathlib.py')]

Navigating inside a directory tree:

     >>> p = Path('/etc')
     >>> q = p / 'init.d' / 'reboot'
     >>> q
     PosixPath('/etc/init.d/reboot')
     >>> q.resolve()
     PosixPath('/etc/rc.d/init.d/halt')

Querying path properties:

     >>> q.exists()
     True
     >>> q.is_dir()
     False

Opening a file:

     >>> with q.open() as f: f.readline()
     ...
     '#!/bin/bash\n'


File: python.info,  Node: Exceptions<5>,  Next: Pure paths,  Prev: Basic use<2>,  Up: pathlib — Object-oriented filesystem paths

5.11.1.2 Exceptions
...................

 -- Eccezione: pathlib.UnsupportedOperation

     An exception inheriting *note NotImplementedError: 36b. that is
     raised when an unsupported operation is called on a path object.

     Added in version 3.13.


File: python.info,  Node: Pure paths,  Next: Concrete paths,  Prev: Exceptions<5>,  Up: pathlib — Object-oriented filesystem paths

5.11.1.3 Pure paths
...................

Pure path objects provide path-handling operations which don’t actually
access a filesystem.  There are three ways to access these classes,
which we also call 'flavours':

 -- Classe: pathlib.PurePath (*pathsegments)

     A generic class that represents the system’s path flavour
     (instantiating it creates either a *note PurePosixPath: 2c0a. or a
     *note PureWindowsPath: 1a5d.):

          >>> PurePath('setup.py')      # Running on a Unix machine
          PurePosixPath('setup.py')

     Each element of 'pathsegments' can be either a string representing
     a path segment, or an object implementing the *note os.PathLike:
     e4d. interface where the *note __fspath__(): e4e. method returns a
     string, such as another path object:

          >>> PurePath('foo', 'some/path', 'bar')
          PurePosixPath('foo/some/path/bar')
          >>> PurePath(Path('foo'), Path('bar'))
          PurePosixPath('foo/bar')

     When 'pathsegments' is empty, the current directory is assumed:

          >>> PurePath()
          PurePosixPath('.')

     If a segment is an absolute path, all previous segments are ignored
     (like *note os.path.join(): 1991.):

          >>> PurePath('/etc', '/usr', 'lib64')
          PurePosixPath('/usr/lib64')
          >>> PureWindowsPath('c:/Windows', 'd:bar')
          PureWindowsPath('d:bar')

     On Windows, the drive is not reset when a rooted relative path
     segment (e.g., ‘r'\foo'’) is encountered:

          >>> PureWindowsPath('c:/Windows', '/Program Files')
          PureWindowsPath('c:/Program Files')

     Spurious slashes and single dots are collapsed, but double dots
     (‘'..'’) and leading double slashes (‘'//'’) are not, since this
     would change the meaning of a path for various reasons (e.g.
     symbolic links, UNC paths):

          >>> PurePath('foo//bar')
          PurePosixPath('foo/bar')
          >>> PurePath('//foo/bar')
          PurePosixPath('//foo/bar')
          >>> PurePath('foo/./bar')
          PurePosixPath('foo/bar')
          >>> PurePath('foo/../bar')
          PurePosixPath('foo/../bar')

     (a naïve approach would make ‘PurePosixPath('foo/../bar')’
     equivalent to ‘PurePosixPath('bar')’, which is wrong if ‘foo’ is a
     symbolic link to another directory)

     Pure path objects implement the *note os.PathLike: e4d. interface,
     allowing them to be used anywhere the interface is accepted.

     Cambiato nella versione 3.6: Added support for the *note
     os.PathLike: e4d. interface.

 -- Classe: pathlib.PurePosixPath (*pathsegments)

     A subclass of *note PurePath: 6ce, this path flavour represents
     non-Windows filesystem paths:

          >>> PurePosixPath('/etc/hosts')
          PurePosixPath('/etc/hosts')

     'pathsegments' is specified similarly to *note PurePath: 6ce.

 -- Classe: pathlib.PureWindowsPath (*pathsegments)

     A subclass of *note PurePath: 6ce, this path flavour represents
     Windows filesystem paths, including UNC paths(1):

          >>> PureWindowsPath('c:/', 'Users', 'Ximénez')
          PureWindowsPath('c:/Users/Ximénez')
          >>> PureWindowsPath('//server/share/file')
          PureWindowsPath('//server/share/file')

     'pathsegments' is specified similarly to *note PurePath: 6ce.

Regardless of the system you’re running on, you can instantiate all of
these classes, since they don’t provide any operation that does system
calls.

* Menu:

* General properties::
* Operators::
* Accessing individual parts::
* Methods and properties::

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Path_(computing)#UNC


File: python.info,  Node: General properties,  Next: Operators,  Up: Pure paths

5.11.1.4 General properties
...........................

Paths are immutable and *note hashable: 825.  Paths of a same flavour
are comparable and orderable.  These properties respect the flavour’s
case-folding semantics:

     >>> PurePosixPath('foo') == PurePosixPath('FOO')
     False
     >>> PureWindowsPath('foo') == PureWindowsPath('FOO')
     True
     >>> PureWindowsPath('FOO') in { PureWindowsPath('foo') }
     True
     >>> PureWindowsPath('C:') < PureWindowsPath('d:')
     True

Paths of a different flavour compare unequal and cannot be ordered:

     >>> PureWindowsPath('foo') == PurePosixPath('foo')
     False
     >>> PureWindowsPath('foo') < PurePosixPath('foo')
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: '<' not supported between instances of 'PureWindowsPath' and 'PurePosixPath'


File: python.info,  Node: Operators,  Next: Accessing individual parts,  Prev: General properties,  Up: Pure paths

5.11.1.5 Operators
..................

The slash operator helps create child paths, like *note os.path.join():
1991.  If the argument is an absolute path, the previous path is
ignored.  On Windows, the drive is not reset when the argument is a
rooted relative path (e.g., ‘r'\foo'’):

     >>> p = PurePath('/etc')
     >>> p
     PurePosixPath('/etc')
     >>> p / 'init.d' / 'apache2'
     PurePosixPath('/etc/init.d/apache2')
     >>> q = PurePath('bin')
     >>> '/usr' / q
     PurePosixPath('/usr/bin')
     >>> p / '/an_absolute_path'
     PurePosixPath('/an_absolute_path')
     >>> PureWindowsPath('c:/Windows', '/Program Files')
     PureWindowsPath('c:/Program Files')

A path object can be used anywhere an object implementing *note
os.PathLike: e4d. is accepted:

     >>> import os
     >>> p = PurePath('/etc')
     >>> os.fspath(p)
     '/etc'

The string representation of a path is the raw filesystem path itself
(in native form, e.g.  with backslashes under Windows), which you can
pass to any function taking a file path as a string:

     >>> p = PurePath('/etc')
     >>> str(p)
     '/etc'
     >>> p = PureWindowsPath('c:/Program Files')
     >>> str(p)
     'c:\\Program Files'

Similarly, calling *note bytes: 192. on a path gives the raw filesystem
path as a bytes object, as encoded by *note os.fsencode(): e51.:

     >>> bytes(p)
     b'/etc'

     Nota: Calling *note bytes: 192. is only recommended under Unix.
     Under Windows, the unicode form is the canonical representation of
     filesystem paths.


File: python.info,  Node: Accessing individual parts,  Next: Methods and properties,  Prev: Operators,  Up: Pure paths

5.11.1.6 Accessing individual parts
...................................

To access the individual «parts» (components) of a path, use the
following property:

 -- Attributo: PurePath.parts

     A tuple giving access to the path’s various components:

          >>> p = PurePath('/usr/bin/python3')
          >>> p.parts
          ('/', 'usr', 'bin', 'python3')

          >>> p = PureWindowsPath('c:/Program Files/PSF')
          >>> p.parts
          ('c:\\', 'Program Files', 'PSF')

     (note how the drive and local root are regrouped in a single part)


File: python.info,  Node: Methods and properties,  Prev: Accessing individual parts,  Up: Pure paths

5.11.1.7 Methods and properties
...............................

Pure paths provide the following methods and properties:

 -- Attributo: PurePath.parser

     The implementation of the *note os.path: a6. module used for
     low-level path parsing and joining: either ‘posixpath’ or ‘ntpath’.

     Added in version 3.13.

 -- Attributo: PurePath.drive

     A string representing the drive letter or name, if any:

          >>> PureWindowsPath('c:/Program Files/').drive
          'c:'
          >>> PureWindowsPath('/Program Files/').drive
          ''
          >>> PurePosixPath('/etc').drive
          ''

     UNC shares are also considered drives:

          >>> PureWindowsPath('//host/share/foo.txt').drive
          '\\\\host\\share'

 -- Attributo: PurePath.root

     A string representing the (local or global) root, if any:

          >>> PureWindowsPath('c:/Program Files/').root
          '\\'
          >>> PureWindowsPath('c:Program Files/').root
          ''
          >>> PurePosixPath('/etc').root
          '/'

     UNC shares always have a root:

          >>> PureWindowsPath('//host/share').root
          '\\'

     If the path starts with more than two successive slashes, *note
     PurePosixPath: 2c0a. collapses them:

          >>> PurePosixPath('//etc').root
          '//'
          >>> PurePosixPath('///etc').root
          '/'
          >>> PurePosixPath('////etc').root
          '/'

          Nota: This behavior conforms to 'The Open Group Base
          Specifications Issue 6', paragraph 4.11 Pathname
          Resolution(1):

          '«A pathname that begins with two successive slashes may be
          interpreted in an implementation-defined manner, although more
          than two leading slashes shall be treated as a single slash.»'

 -- Attributo: PurePath.anchor

     The concatenation of the drive and root:

          >>> PureWindowsPath('c:/Program Files/').anchor
          'c:\\'
          >>> PureWindowsPath('c:Program Files/').anchor
          'c:'
          >>> PurePosixPath('/etc').anchor
          '/'
          >>> PureWindowsPath('//host/share').anchor
          '\\\\host\\share\\'

 -- Attributo: PurePath.parents

     An immutable sequence providing access to the logical ancestors of
     the path:

          >>> p = PureWindowsPath('c:/foo/bar/setup.py')
          >>> p.parents[0]
          PureWindowsPath('c:/foo/bar')
          >>> p.parents[1]
          PureWindowsPath('c:/foo')
          >>> p.parents[2]
          PureWindowsPath('c:/')

     Cambiato nella versione 3.10: The parents sequence now supports
     *note slices: 25ba. and negative index values.

 -- Attributo: PurePath.parent

     The logical parent of the path:

          >>> p = PurePosixPath('/a/b/c/d')
          >>> p.parent
          PurePosixPath('/a/b/c')

     You cannot go past an anchor, or empty path:

          >>> p = PurePosixPath('/')
          >>> p.parent
          PurePosixPath('/')
          >>> p = PurePosixPath('.')
          >>> p.parent
          PurePosixPath('.')

          Nota: This is a purely lexical operation, hence the following
          behaviour:

               >>> p = PurePosixPath('foo/..')
               >>> p.parent
               PurePosixPath('foo')

          If you want to walk an arbitrary filesystem path upwards, it
          is recommended to first call *note Path.resolve(): 1a55. so as
          to resolve symlinks and eliminate ‘".."’ components.

 -- Attributo: PurePath.name

     A string representing the final path component, excluding the drive
     and root, if any:

          >>> PurePosixPath('my/library/setup.py').name
          'setup.py'

     UNC drive names are not considered:

          >>> PureWindowsPath('//some/share/setup.py').name
          'setup.py'
          >>> PureWindowsPath('//some/share').name
          ''

 -- Attributo: PurePath.suffix

     The last dot-separated portion of the final component, if any:

          >>> PurePosixPath('my/library/setup.py').suffix
          '.py'
          >>> PurePosixPath('my/library.tar.gz').suffix
          '.gz'
          >>> PurePosixPath('my/library').suffix
          ''

     This is commonly called the file extension.

     Cambiato nella versione 3.14: A single dot (»‘.’») is considered a
     valid suffix.

 -- Attributo: PurePath.suffixes

     A list of the path’s suffixes, often called file extensions:

          >>> PurePosixPath('my/library.tar.gar').suffixes
          ['.tar', '.gar']
          >>> PurePosixPath('my/library.tar.gz').suffixes
          ['.tar', '.gz']
          >>> PurePosixPath('my/library').suffixes
          []

     Cambiato nella versione 3.14: A single dot (»‘.’») is considered a
     valid suffix.

 -- Attributo: PurePath.stem

     The final path component, without its suffix:

          >>> PurePosixPath('my/library.tar.gz').stem
          'library.tar'
          >>> PurePosixPath('my/library.tar').stem
          'library'
          >>> PurePosixPath('my/library').stem
          'library'

 -- Metodo: PurePath.as_posix ()

     Return a string representation of the path with forward slashes
     (‘/’):

          >>> p = PureWindowsPath('c:\\windows')
          >>> str(p)
          'c:\\windows'
          >>> p.as_posix()
          'c:/windows'

 -- Metodo: PurePath.is_absolute ()

     Return whether the path is absolute or not.  A path is considered
     absolute if it has both a root and (if the flavour allows) a drive:

          >>> PurePosixPath('/a/b').is_absolute()
          True
          >>> PurePosixPath('a/b').is_absolute()
          False

          >>> PureWindowsPath('c:/a/b').is_absolute()
          True
          >>> PureWindowsPath('/a/b').is_absolute()
          False
          >>> PureWindowsPath('c:').is_absolute()
          False
          >>> PureWindowsPath('//some/share').is_absolute()
          True

 -- Metodo: PurePath.is_relative_to (other)

     Return whether or not this path is relative to the 'other' path.

          >>> p = PurePath('/etc/passwd')
          >>> p.is_relative_to('/etc')
          True
          >>> p.is_relative_to('/usr')
          False

     This method is string-based; it neither accesses the filesystem nor
     treats «‘..’» segments specially.  The following code is
     equivalent:

          >>> u = PurePath('/usr')
          >>> u == p or u in p.parents
          False

     Added in version 3.9.

     Deprecated since version 3.12, removed in version 3.14: Passing
     additional arguments is deprecated; if supplied, they are joined
     with 'other'.

 -- Metodo: PurePath.is_reserved ()

     With *note PureWindowsPath: 1a5d, return ‘True’ if the path is
     considered reserved under Windows, ‘False’ otherwise.  With *note
     PurePosixPath: 2c0a, ‘False’ is always returned.

     Cambiato nella versione 3.13: Windows path names that contain a
     colon, or end with a dot or a space, are considered reserved.  UNC
     paths may be reserved.

     Deprecated since version 3.13, will be removed in version 3.15:
     This method is deprecated; use *note os.path.isreserved(): 32b. to
     detect reserved paths on Windows.

 -- Metodo: PurePath.joinpath (*pathsegments)

     Calling this method is equivalent to combining the path with each
     of the given 'pathsegments' in turn:

          >>> PurePosixPath('/etc').joinpath('passwd')
          PurePosixPath('/etc/passwd')
          >>> PurePosixPath('/etc').joinpath(PurePosixPath('passwd'))
          PurePosixPath('/etc/passwd')
          >>> PurePosixPath('/etc').joinpath('init.d', 'apache2')
          PurePosixPath('/etc/init.d/apache2')
          >>> PureWindowsPath('c:').joinpath('/Program Files')
          PureWindowsPath('c:/Program Files')

 -- Metodo: PurePath.full_match (pattern, *, case_sensitive=None)

     Match this path against the provided glob-style pattern.  Return
     ‘True’ if matching is successful, ‘False’ otherwise.  For example:

          >>> PurePath('a/b.py').full_match('a/*.py')
          True
          >>> PurePath('a/b.py').full_match('*.py')
          False
          >>> PurePath('/a/b/c.py').full_match('/a/**')
          True
          >>> PurePath('/a/b/c.py').full_match('**/*.py')
          True

     Vedi anche
     ..........

     *note Pattern language: 2c17. documentation.

     As with other methods, case-sensitivity follows platform defaults:

          >>> PurePosixPath('b.py').full_match('*.PY')
          False
          >>> PureWindowsPath('b.py').full_match('*.PY')
          True

     Set 'case_sensitive' to ‘True’ or ‘False’ to override this
     behaviour.

     Added in version 3.13.

 -- Metodo: PurePath.match (pattern, *, case_sensitive=None)

     Match this path against the provided non-recursive glob-style
     pattern.  Return ‘True’ if matching is successful, ‘False’
     otherwise.

     This method is similar to *note full_match(): 536, but empty
     patterns aren’t allowed (*note ValueError: 2ec. is raised), the
     recursive wildcard «‘**’» isn’t supported (it acts like
     non-recursive «‘*’»), and if a relative pattern is provided, then
     matching is done from the right:

          >>> PurePath('a/b.py').match('*.py')
          True
          >>> PurePath('/a/b/c.py').match('b/*.py')
          True
          >>> PurePath('/a/b/c.py').match('a/*.py')
          False

     Cambiato nella versione 3.12: The 'pattern' parameter accepts a
     *note path-like object: 5a1.

     Cambiato nella versione 3.12: The 'case_sensitive' parameter was
     added.

 -- Metodo: PurePath.relative_to (other, walk_up=False)

     Compute a version of this path relative to the path represented by
     'other'.  If it’s impossible, *note ValueError: 2ec. is raised:

          >>> p = PurePosixPath('/etc/passwd')
          >>> p.relative_to('/')
          PurePosixPath('etc/passwd')
          >>> p.relative_to('/etc')
          PurePosixPath('passwd')
          >>> p.relative_to('/usr')
          Traceback (most recent call last):
            File "<stdin>", line 1, in <module>
            File "pathlib.py", line 941, in relative_to
              raise ValueError(error_message.format(str(self), str(formatted)))
          ValueError: '/etc/passwd' is not in the subpath of '/usr' OR one path is relative and the other is absolute.

     When 'walk_up' is false (the default), the path must start with
     'other'.  When the argument is true, ‘..’ entries may be added to
     form the relative path.  In all other cases, such as the paths
     referencing different drives, *note ValueError: 2ec. is raised.:

          >>> p.relative_to('/usr', walk_up=True)
          PurePosixPath('../etc/passwd')
          >>> p.relative_to('foo', walk_up=True)
          Traceback (most recent call last):
            File "<stdin>", line 1, in <module>
            File "pathlib.py", line 941, in relative_to
              raise ValueError(error_message.format(str(self), str(formatted)))
          ValueError: '/etc/passwd' is not on the same drive as 'foo' OR one path is relative and the other is absolute.

          Avvertimento: This function is part of *note PurePath: 6ce.
          and works with strings.  It does not check or access the
          underlying file structure.  This can impact the 'walk_up'
          option as it assumes that no symlinks are present in the path;
          call *note resolve(): 1a55. first if necessary to resolve
          symlinks.

     Cambiato nella versione 3.12: The 'walk_up' parameter was added
     (old behavior is the same as ‘walk_up=False’).

     Deprecated since version 3.12, removed in version 3.14: Passing
     additional positional arguments is deprecated; if supplied, they
     are joined with 'other'.

 -- Metodo: PurePath.with_name (name)

     Return a new path with the *note name: 2c13. changed.  If the
     original path doesn’t have a name, ValueError is raised:

          >>> p = PureWindowsPath('c:/Downloads/pathlib.tar.gz')
          >>> p.with_name('setup.py')
          PureWindowsPath('c:/Downloads/setup.py')
          >>> p = PureWindowsPath('c:/')
          >>> p.with_name('setup.py')
          Traceback (most recent call last):
            File "<stdin>", line 1, in <module>
            File "/home/antoine/cpython/default/Lib/pathlib.py", line 751, in with_name
              raise ValueError("%r has an empty name" % (self,))
          ValueError: PureWindowsPath('c:/') has an empty name

 -- Metodo: PurePath.with_stem (stem)

     Return a new path with the *note stem: 2c14. changed.  If the
     original path doesn’t have a name, ValueError is raised:

          >>> p = PureWindowsPath('c:/Downloads/draft.txt')
          >>> p.with_stem('final')
          PureWindowsPath('c:/Downloads/final.txt')
          >>> p = PureWindowsPath('c:/Downloads/pathlib.tar.gz')
          >>> p.with_stem('lib')
          PureWindowsPath('c:/Downloads/lib.gz')
          >>> p = PureWindowsPath('c:/')
          >>> p.with_stem('')
          Traceback (most recent call last):
            File "<stdin>", line 1, in <module>
            File "/home/antoine/cpython/default/Lib/pathlib.py", line 861, in with_stem
              return self.with_name(stem + self.suffix)
            File "/home/antoine/cpython/default/Lib/pathlib.py", line 851, in with_name
              raise ValueError("%r has an empty name" % (self,))
          ValueError: PureWindowsPath('c:/') has an empty name

     Added in version 3.9.

 -- Metodo: PurePath.with_suffix (suffix)

     Return a new path with the *note suffix: 193f. changed.  If the
     original path doesn’t have a suffix, the new 'suffix' is appended
     instead.  If the 'suffix' is an empty string, the original suffix
     is removed:

          >>> p = PureWindowsPath('c:/Downloads/pathlib.tar.gz')
          >>> p.with_suffix('.bz2')
          PureWindowsPath('c:/Downloads/pathlib.tar.bz2')
          >>> p = PureWindowsPath('README')
          >>> p.with_suffix('.txt')
          PureWindowsPath('README.txt')
          >>> p = PureWindowsPath('README.txt')
          >>> p.with_suffix('')
          PureWindowsPath('README')

     Cambiato nella versione 3.14: A single dot (»‘.’») is considered a
     valid suffix.  In previous versions, *note ValueError: 2ec. is
     raised if a single dot is supplied.

 -- Metodo: PurePath.with_segments (*pathsegments)

     Create a new path object of the same type by combining the given
     'pathsegments'.  This method is called whenever a derivative path
     is created, such as from *note parent: 1a85. and *note
     relative_to(): 2fd.  Subclasses may override this method to pass
     information to derivative paths, for example:

          from pathlib import PurePosixPath

          class MyPath(PurePosixPath):
              def __init__(self, *pathsegments, session_id):
                  super().__init__(*pathsegments)
                  self.session_id = session_id

              def with_segments(self, *pathsegments):
                  return type(self)(*pathsegments, session_id=self.session_id)

          etc = MyPath('/etc', session_id=42)
          hosts = etc / 'hosts'
          print(hosts.session_id)  # 42

     Added in version 3.12.

   ---------- Footnotes ----------

   (1) 
https://pubs.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap04.html#tag_04_11


File: python.info,  Node: Concrete paths,  Next: Pattern language,  Prev: Pure paths,  Up: pathlib — Object-oriented filesystem paths

5.11.1.8 Concrete paths
.......................

Concrete paths are subclasses of the pure path classes.  In addition to
operations provided by the latter, they also provide methods to do
system calls on path objects.  There are three ways to instantiate
concrete paths:

 -- Classe: pathlib.Path (*pathsegments)

     A subclass of *note PurePath: 6ce, this class represents concrete
     paths of the system’s path flavour (instantiating it creates either
     a *note PosixPath: 2c19. or a *note WindowsPath: 2c06.):

          >>> Path('setup.py')
          PosixPath('setup.py')

     'pathsegments' is specified similarly to *note PurePath: 6ce.

 -- Classe: pathlib.PosixPath (*pathsegments)

     A subclass of *note Path: 266. and *note PurePosixPath: 2c0a, this
     class represents concrete non-Windows filesystem paths:

          >>> PosixPath('/etc/hosts')
          PosixPath('/etc/hosts')

     'pathsegments' is specified similarly to *note PurePath: 6ce.

     Cambiato nella versione 3.13: Raises *note UnsupportedOperation:
     534. on Windows.  In previous versions, *note NotImplementedError:
     36b. was raised instead.

 -- Classe: pathlib.WindowsPath (*pathsegments)

     A subclass of *note Path: 266. and *note PureWindowsPath: 1a5d,
     this class represents concrete Windows filesystem paths:

          >>> WindowsPath('c:/', 'Users', 'Ximénez')
          WindowsPath('c:/Users/Ximénez')

     'pathsegments' is specified similarly to *note PurePath: 6ce.

     Cambiato nella versione 3.13: Raises *note UnsupportedOperation:
     534. on non-Windows platforms.  In previous versions, *note
     NotImplementedError: 36b. was raised instead.

You can only instantiate the class flavour that corresponds to your
system (allowing system calls on non-compatible path flavours could lead
to bugs or failures in your application):

     >>> import os
     >>> os.name
     'posix'
     >>> Path('setup.py')
     PosixPath('setup.py')
     >>> PosixPath('setup.py')
     PosixPath('setup.py')
     >>> WindowsPath('setup.py')
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
       File "pathlib.py", line 798, in __new__
         % (cls.__name__,))
     UnsupportedOperation: cannot instantiate 'WindowsPath' on your system

Some concrete path methods can raise an *note OSError: 2c0. if a system
call fails (for example because the path doesn’t exist).

* Menu:

* Parsing and generating URIs::
* Expanding and resolving paths::
* Querying file type and status::
* Reading and writing files::
* Reading directories::
* Creating files and directories::
* Copying, moving and deleting: Copying moving and deleting.
* Permissions and ownership::


File: python.info,  Node: Parsing and generating URIs,  Next: Expanding and resolving paths,  Up: Concrete paths

5.11.1.9 Parsing and generating URIs
....................................

Concrete path objects can be created from, and represented as, “file”
URIs conforming to RFC 8089(1).

     Nota: File URIs are not portable across machines with different
     *note filesystem encodings: 2c1b.

 -- Metodo: classmethod Path.from_uri (uri)

     Return a new path object from parsing a “file” URI. For example:

          >>> p = Path.from_uri('file:///etc/hosts')
          PosixPath('/etc/hosts')

     On Windows, DOS device and UNC paths may be parsed from URIs:

          >>> p = Path.from_uri('file:///c:/windows')
          WindowsPath('c:/windows')
          >>> p = Path.from_uri('file://server/share')
          WindowsPath('//server/share')

     Several variant forms are supported:

          >>> p = Path.from_uri('file:////server/share')
          WindowsPath('//server/share')
          >>> p = Path.from_uri('file://///server/share')
          WindowsPath('//server/share')
          >>> p = Path.from_uri('file:c:/windows')
          WindowsPath('c:/windows')
          >>> p = Path.from_uri('file:/c|/windows')
          WindowsPath('c:/windows')

     *note ValueError: 2ec. is raised if the URI does not start with
     ‘file:’, or the parsed path isn’t absolute.

     Added in version 3.13.

     Cambiato nella versione 3.14: The URL authority is discarded if it
     matches the local hostname.  Otherwise, if the authority isn’t
     empty or ‘localhost’, then on Windows a UNC path is returned (as
     before), and on other platforms a *note ValueError: 2ec. is raised.

 -- Metodo: Path.as_uri ()

     Represent the path as a “file” URI. *note ValueError: 2ec. is
     raised if the path isn’t absolute.

          >>> p = PosixPath('/etc/passwd')
          >>> p.as_uri()
          'file:///etc/passwd'
          >>> p = WindowsPath('c:/Windows')
          >>> p.as_uri()
          'file:///c:/Windows'

     Deprecated since version 3.14, will be removed in version 3.19:
     Calling this method from *note PurePath: 6ce. rather than *note
     Path: 266. is possible but deprecated.  The method’s use of *note
     os.fsencode(): e51. makes it strictly impure.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc8089.html


File: python.info,  Node: Expanding and resolving paths,  Next: Querying file type and status,  Prev: Parsing and generating URIs,  Up: Concrete paths

5.11.1.10 Expanding and resolving paths
.......................................

 -- Metodo: classmethod Path.home ()

     Return a new path object representing the user’s home directory (as
     returned by *note os.path.expanduser(): c0b. with ‘~’ construct).
     If the home directory can’t be resolved, *note RuntimeError: 244.
     is raised.

          >>> Path.home()
          PosixPath('/home/antoine')

     Added in version 3.5.

 -- Metodo: Path.expanduser ()

     Return a new path with expanded ‘~’ and ‘~user’ constructs, as
     returned by *note os.path.expanduser(): c0b.  If a home directory
     can’t be resolved, *note RuntimeError: 244. is raised.

          >>> p = PosixPath('~/films/Monty Python')
          >>> p.expanduser()
          PosixPath('/home/eric/films/Monty Python')

     Added in version 3.5.

 -- Metodo: classmethod Path.cwd ()

     Return a new path object representing the current directory (as
     returned by *note os.getcwd(): 18f1.):

          >>> Path.cwd()
          PosixPath('/home/antoine/pathlib')

 -- Metodo: Path.absolute ()

     Make the path absolute, without normalization or resolving
     symlinks.  Returns a new path object:

          >>> p = Path('tests')
          >>> p
          PosixPath('tests')
          >>> p.absolute()
          PosixPath('/home/antoine/pathlib/tests')

 -- Metodo: Path.resolve (strict=False)

     Make the path absolute, resolving any symlinks.  A new path object
     is returned:

          >>> p = Path()
          >>> p
          PosixPath('.')
          >>> p.resolve()
          PosixPath('/home/antoine/pathlib')

     «‘..’» components are also eliminated (this is the only method to
     do so):

          >>> p = Path('docs/../setup.py')
          >>> p.resolve()
          PosixPath('/home/antoine/pathlib/setup.py')

     If a path doesn’t exist or a symlink loop is encountered, and
     'strict' is ‘True’, *note OSError: 2c0. is raised.  If 'strict' is
     ‘False’, the path is resolved as far as possible and any remainder
     is appended without checking whether it exists.

     Cambiato nella versione 3.6: The 'strict' parameter was added
     (pre-3.6 behavior is strict).

     Cambiato nella versione 3.13: Symlink loops are treated like other
     errors: *note OSError: 2c0. is raised in strict mode, and no
     exception is raised in non-strict mode.  In previous versions,
     *note RuntimeError: 244. is raised no matter the value of 'strict'.

 -- Metodo: Path.readlink ()

     Return the path to which the symbolic link points (as returned by
     *note os.readlink(): b1c.):

          >>> p = Path('mylink')
          >>> p.symlink_to('setup.py')
          >>> p.readlink()
          PosixPath('setup.py')

     Added in version 3.9.

     Cambiato nella versione 3.13: Raises *note UnsupportedOperation:
     534. if *note os.readlink(): b1c. is not available.  In previous
     versions, *note NotImplementedError: 36b. was raised.


File: python.info,  Node: Querying file type and status,  Next: Reading and writing files,  Prev: Expanding and resolving paths,  Up: Concrete paths

5.11.1.11 Querying file type and status
.......................................

Cambiato nella versione 3.8: *note exists(): c0d, *note is_dir(): 53b,
*note is_file(): 53a, *note is_mount(): c0e, *note is_symlink(): c0f,
*note is_block_device(): c10, *note is_char_device(): c11, *note
is_fifo(): c12, *note is_socket(): c13. now return ‘False’ instead of
raising an exception for paths that contain characters unrepresentable
at the OS level.

Cambiato nella versione 3.14: The methods given above now return ‘False’
instead of raising any *note OSError: 2c0. exception from the operating
system.  In previous versions, some kinds of *note OSError: 2c0.
exception are raised, and others suppressed.  The new behaviour is
consistent with *note os.path.exists(): c05, *note os.path.isdir(): c07,
etc.  Use *note stat(): a26. to retrieve the file status without
suppressing exceptions.

 -- Metodo: Path.stat (*, follow_symlinks=True)

     Return an *note os.stat_result: 16c8. object containing information
     about this path, like *note os.stat(): 26d.  The result is looked
     up at each call to this method.

     This method normally follows symlinks; to stat a symlink add the
     argument ‘follow_symlinks=False’, or use *note lstat(): 2c1e.

          >>> p = Path('setup.py')
          >>> p.stat().st_size
          956
          >>> p.stat().st_mtime
          1327883547.852554

     Cambiato nella versione 3.10: The 'follow_symlinks' parameter was
     added.

 -- Metodo: Path.lstat ()

     Like *note Path.stat(): a26. but, if the path points to a symbolic
     link, return the symbolic link’s information rather than its
     target’s.

 -- Metodo: Path.exists (*, follow_symlinks=True)

     Return ‘True’ if the path points to an existing file or directory.
     ‘False’ will be returned if the path is invalid, inaccessible or
     missing.  Use *note Path.stat(): a26. to distinguish between these
     cases.

     This method normally follows symlinks; to check if a symlink
     exists, add the argument ‘follow_symlinks=False’.

          >>> Path('.').exists()
          True
          >>> Path('setup.py').exists()
          True
          >>> Path('/etc').exists()
          True
          >>> Path('nonexistentfile').exists()
          False

     Cambiato nella versione 3.12: The 'follow_symlinks' parameter was
     added.

 -- Metodo: Path.is_file (*, follow_symlinks=True)

     Return ‘True’ if the path points to a regular file.  ‘False’ will
     be returned if the path is invalid, inaccessible or missing, or if
     it points to something other than a regular file.  Use *note
     Path.stat(): a26. to distinguish between these cases.

     This method normally follows symlinks; to exclude symlinks, add the
     argument ‘follow_symlinks=False’.

     Cambiato nella versione 3.13: The 'follow_symlinks' parameter was
     added.

 -- Metodo: Path.is_dir (*, follow_symlinks=True)

     Return ‘True’ if the path points to a directory.  ‘False’ will be
     returned if the path is invalid, inaccessible or missing, or if it
     points to something other than a directory.  Use *note Path.stat():
     a26. to distinguish between these cases.

     This method normally follows symlinks; to exclude symlinks to
     directories, add the argument ‘follow_symlinks=False’.

     Cambiato nella versione 3.13: The 'follow_symlinks' parameter was
     added.

 -- Metodo: Path.is_symlink ()

     Return ‘True’ if the path points to a symbolic link, even if that
     symlink is broken.  ‘False’ will be returned if the path is
     invalid, inaccessible or missing, or if it points to something
     other than a symbolic link.  Use *note Path.stat(): a26. to
     distinguish between these cases.

 -- Metodo: Path.is_junction ()

     Return ‘True’ if the path points to a junction, and ‘False’ for any
     other type of file.  Currently only Windows supports junctions.

     Added in version 3.12.

 -- Metodo: Path.is_mount ()

     Return ‘True’ if the path is a 'mount point': a point in a file
     system where a different file system has been mounted.  On POSIX,
     the function checks whether 'path'’s parent, ‘path/..’, is on a
     different device than 'path', or whether ‘path/..’ and 'path' point
     to the same i-node on the same device — this should detect mount
     points for all Unix and POSIX variants.  On Windows, a mount point
     is considered to be a drive letter root (e.g.  ‘c:\’), a UNC share
     (e.g.  ‘\\server\share’), or a mounted filesystem directory.

     Added in version 3.7.

     Cambiato nella versione 3.12: Windows support was added.

 -- Metodo: Path.is_socket ()

     Return ‘True’ if the path points to a Unix socket.  ‘False’ will be
     returned if the path is invalid, inaccessible or missing, or if it
     points to something other than a Unix socket.  Use *note
     Path.stat(): a26. to distinguish between these cases.

 -- Metodo: Path.is_fifo ()

     Return ‘True’ if the path points to a FIFO. ‘False’ will be
     returned if the path is invalid, inaccessible or missing, or if it
     points to something other than a FIFO. Use *note Path.stat(): a26.
     to distinguish between these cases.

 -- Metodo: Path.is_block_device ()

     Return ‘True’ if the path points to a block device.  ‘False’ will
     be returned if the path is invalid, inaccessible or missing, or if
     it points to something other than a block device.  Use *note
     Path.stat(): a26. to distinguish between these cases.

 -- Metodo: Path.is_char_device ()

     Return ‘True’ if the path points to a character device.  ‘False’
     will be returned if the path is invalid, inaccessible or missing,
     or if it points to something other than a character device.  Use
     *note Path.stat(): a26. to distinguish between these cases.

 -- Metodo: Path.samefile (other_path)

     Return whether this path points to the same file as 'other_path',
     which can be either a Path object, or a string.  The semantics are
     similar to *note os.path.samefile(): 1173. and *note
     os.path.samestat(): 1172.

     An *note OSError: 2c0. can be raised if either file cannot be
     accessed for some reason.

          >>> p = Path('spam')
          >>> q = Path('eggs')
          >>> p.samefile(q)
          False
          >>> p.samefile('spam')
          True

     Added in version 3.5.

 -- Attributo: Path.info

     A *note PathInfo: 26c. object that supports querying file type
     information.  The object exposes methods that cache their results,
     which can help reduce the number of system calls needed when
     switching on file type.  For example:

          >>> p = Path('src')
          >>> if p.info.is_symlink():
          ...     print('symlink')
          ... elif p.info.is_dir():
          ...     print('directory')
          ... elif p.info.exists():
          ...     print('something else')
          ... else:
          ...     print('not found')
          ...
          directory

     If the path was generated from *note Path.iterdir(): 26e. then this
     attribute is initialized with some information about the file type
     gleaned from scanning the parent directory.  Merely accessing *note
     Path.info: 26b. does not perform any filesystem queries.

     To fetch up-to-date information, it’s best to call *note
     Path.is_dir(): 53b, *note is_file(): 53a. and *note is_symlink():
     c0f. rather than methods of this attribute.  There is no way to
     reset the cache; instead you can create a new path object with an
     empty info cache via ‘p = Path(p)’.

     Added in version 3.14.


File: python.info,  Node: Reading and writing files,  Next: Reading directories,  Prev: Querying file type and status,  Up: Concrete paths

5.11.1.12 Reading and writing files
...................................

 -- Metodo: Path.open (mode='r', buffering=-1, encoding=None,
          errors=None, newline=None)

     Open the file pointed to by the path, like the built-in *note
     open(): 316. function does:

          >>> p = Path('setup.py')
          >>> with p.open() as f:
          ...     f.readline()
          ...
          '#!/usr/bin/env python3\n'

 -- Metodo: Path.read_text (encoding=None, errors=None, newline=None)

     Return the decoded contents of the pointed-to file as a string:

          >>> p = Path('my_text_file')
          >>> p.write_text('Text file contents')
          18
          >>> p.read_text()
          'Text file contents'

     The file is opened and then closed.  The optional parameters have
     the same meaning as in *note open(): 316.

     Added in version 3.5.

     Cambiato nella versione 3.13: The 'newline' parameter was added.

 -- Metodo: Path.read_bytes ()

     Return the binary contents of the pointed-to file as a bytes
     object:

          >>> p = Path('my_binary_file')
          >>> p.write_bytes(b'Binary file contents')
          20
          >>> p.read_bytes()
          b'Binary file contents'

     Added in version 3.5.

 -- Metodo: Path.write_text (data, encoding=None, errors=None,
          newline=None)

     Open the file pointed to in text mode, write 'data' to it, and
     close the file:

          >>> p = Path('my_text_file')
          >>> p.write_text('Text file contents')
          18
          >>> p.read_text()
          'Text file contents'

     An existing file of the same name is overwritten.  The optional
     parameters have the same meaning as in *note open(): 316.

     Added in version 3.5.

     Cambiato nella versione 3.10: The 'newline' parameter was added.

 -- Metodo: Path.write_bytes (data)

     Open the file pointed to in bytes mode, write 'data' to it, and
     close the file:

          >>> p = Path('my_binary_file')
          >>> p.write_bytes(b'Binary file contents')
          20
          >>> p.read_bytes()
          b'Binary file contents'

     An existing file of the same name is overwritten.

     Added in version 3.5.


File: python.info,  Node: Reading directories,  Next: Creating files and directories,  Prev: Reading and writing files,  Up: Concrete paths

5.11.1.13 Reading directories
.............................

 -- Metodo: Path.iterdir ()

     When the path points to a directory, yield path objects of the
     directory contents:

          >>> p = Path('docs')
          >>> for child in p.iterdir(): child
          ...
          PosixPath('docs/conf.py')
          PosixPath('docs/_templates')
          PosixPath('docs/make.bat')
          PosixPath('docs/index.rst')
          PosixPath('docs/_build')
          PosixPath('docs/_static')
          PosixPath('docs/Makefile')

     The children are yielded in arbitrary order, and the special
     entries ‘'.'’ and ‘'..'’ are not included.  If a file is removed
     from or added to the directory after creating the iterator, it is
     unspecified whether a path object for that file is included.

     If the path is not a directory or otherwise inaccessible, *note
     OSError: 2c0. is raised.

 -- Metodo: Path.glob (pattern, *, case_sensitive=None,
          recurse_symlinks=False)

     Glob the given relative 'pattern' in the directory represented by
     this path, yielding all matching files (of any kind):

          >>> sorted(Path('.').glob('*.py'))
          [PosixPath('pathlib.py'), PosixPath('setup.py'), PosixPath('test_pathlib.py')]
          >>> sorted(Path('.').glob('*/*.py'))
          [PosixPath('docs/conf.py')]
          >>> sorted(Path('.').glob('**/*.py'))
          [PosixPath('build/lib/pathlib.py'),
           PosixPath('docs/conf.py'),
           PosixPath('pathlib.py'),
           PosixPath('setup.py'),
           PosixPath('test_pathlib.py')]

          Nota: The paths are returned in no particular order.  If you
          need a specific order, sort the results.

     Vedi anche
     ..........

     *note Pattern language: 2c17. documentation.

     By default, or when the 'case_sensitive' keyword-only argument is
     set to ‘None’, this method matches paths using platform-specific
     casing rules: typically, case-sensitive on POSIX, and
     case-insensitive on Windows.  Set 'case_sensitive' to ‘True’ or
     ‘False’ to override this behaviour.

     By default, or when the 'recurse_symlinks' keyword-only argument is
     set to ‘False’, this method follows symlinks except when expanding
     «‘**’» wildcards.  Set 'recurse_symlinks' to ‘True’ to always
     follow symlinks.

     Raises an *note auditing event: 1c56. ‘pathlib.Path.glob’ with
     arguments ‘self’, ‘pattern’.

     Cambiato nella versione 3.12: The 'case_sensitive' parameter was
     added.

     Cambiato nella versione 3.13: The 'recurse_symlinks' parameter was
     added.

     Cambiato nella versione 3.13: The 'pattern' parameter accepts a
     *note path-like object: 5a1.

     Cambiato nella versione 3.13: Any *note OSError: 2c0. exceptions
     raised from scanning the filesystem are suppressed.  In previous
     versions, such exceptions are suppressed in many cases, but not
     all.

 -- Metodo: Path.rglob (pattern, *, case_sensitive=None,
          recurse_symlinks=False)

     Glob the given relative 'pattern' recursively.  This is like
     calling *note Path.glob(): 538. with «‘**/’» added in front of the
     'pattern'.

          Nota: The paths are returned in no particular order.  If you
          need a specific order, sort the results.

     Vedi anche
     ..........

     *note Pattern language: 2c17. and *note Path.glob(): 538.
     documentation.

     Raises an *note auditing event: 1c56. ‘pathlib.Path.rglob’ with
     arguments ‘self’, ‘pattern’.

     Cambiato nella versione 3.12: The 'case_sensitive' parameter was
     added.

     Cambiato nella versione 3.13: The 'recurse_symlinks' parameter was
     added.

     Cambiato nella versione 3.13: The 'pattern' parameter accepts a
     *note path-like object: 5a1.

 -- Metodo: Path.walk (top_down=True, on_error=None,
          follow_symlinks=False)

     Generate the file names in a directory tree by walking the tree
     either top-down or bottom-up.

     For each directory in the directory tree rooted at 'self'
     (including 'self' but excluding “.” and “..”), the method yields a
     3-tuple of ‘(dirpath, dirnames, filenames)’.

     'dirpath' is a *note Path: 266. to the directory currently being
     walked, 'dirnames' is a list of strings for the names of
     subdirectories in 'dirpath' (excluding ‘'.'’ and ‘'..'’), and
     'filenames' is a list of strings for the names of the non-directory
     files in 'dirpath'.  To get a full path (which begins with 'self')
     to a file or directory in 'dirpath', do ‘dirpath / name’.  Whether
     or not the lists are sorted is file system-dependent.

     If the optional argument 'top_down' is true (which is the default),
     the triple for a directory is generated before the triples for any
     of its subdirectories (directories are walked top-down).  If
     'top_down' is false, the triple for a directory is generated after
     the triples for all of its subdirectories (directories are walked
     bottom-up).  No matter the value of 'top_down', the list of
     subdirectories is retrieved before the triples for the directory
     and its subdirectories are walked.

     When 'top_down' is true, the caller can modify the 'dirnames' list
     in-place (for example, using *note del: 1b07. or slice assignment),
     and *note Path.walk(): 6d0. will only recurse into the
     subdirectories whose names remain in 'dirnames'.  This can be used
     to prune the search, or to impose a specific order of visiting, or
     even to inform *note Path.walk(): 6d0. about directories the caller
     creates or renames before it resumes *note Path.walk(): 6d0. again.
     Modifying 'dirnames' when 'top_down' is false has no effect on the
     behavior of *note Path.walk(): 6d0. since the directories in
     'dirnames' have already been generated by the time 'dirnames' is
     yielded to the caller.

     By default, errors from *note os.scandir(): c56. are ignored.  If
     the optional argument 'on_error' is specified, it should be a
     callable; it will be called with one argument, an *note OSError:
     2c0. instance.  The callable can handle the error to continue the
     walk or re-raise it to stop the walk.  Note that the filename is
     available as the ‘filename’ attribute of the exception object.

     By default, *note Path.walk(): 6d0. does not follow symbolic links,
     and instead adds them to the 'filenames' list.  Set
     'follow_symlinks' to true to resolve symlinks and place them in
     'dirnames' and 'filenames' as appropriate for their targets, and
     consequently visit directories pointed to by symlinks (where
     supported).

          Nota: Be aware that setting 'follow_symlinks' to true can lead
          to infinite recursion if a link points to a parent directory
          of itself.  *note Path.walk(): 6d0. does not keep track of the
          directories it has already visited.

          Nota: *note Path.walk(): 6d0. assumes the directories it walks
          are not modified during execution.  For example, if a
          directory from 'dirnames' has been replaced with a symlink and
          'follow_symlinks' is false, *note Path.walk(): 6d0. will still
          try to descend into it.  To prevent such behavior, remove
          directories from 'dirnames' as appropriate.

          Nota: Unlike *note os.walk(): 6d1, *note Path.walk(): 6d0.
          lists symlinks to directories in 'filenames' if
          'follow_symlinks' is false.

     This example displays the number of bytes used by all files in each
     directory, while ignoring ‘__pycache__’ directories:

          from pathlib import Path
          for root, dirs, files in Path("cpython/Lib/concurrent").walk(on_error=print):
            print(
                root,
                "consumes",
                sum((root / file).stat().st_size for file in files),
                "bytes in",
                len(files),
                "non-directory files"
            )
            if '__pycache__' in dirs:
                  dirs.remove('__pycache__')

     This next example is a simple implementation of *note
     shutil.rmtree(): 356.  Walking the tree bottom-up is essential as
     *note rmdir(): 2c22. doesn’t allow deleting a directory before it
     is empty:

          # Delete everything reachable from the directory "top".
          # CAUTION:  This is dangerous! For example, if top == Path('/'),
          # it could delete all of your files.
          for root, dirs, files in top.walk(top_down=False):
              for name in files:
                  (root / name).unlink()
              for name in dirs:
                  (root / name).rmdir()

     Added in version 3.12.


File: python.info,  Node: Creating files and directories,  Next: Copying moving and deleting,  Prev: Reading directories,  Up: Concrete paths

5.11.1.14 Creating files and directories
........................................

 -- Metodo: Path.touch (mode=0o666, exist_ok=True)

     Create a file at this given path.  If 'mode' is given, it is
     combined with the process’s ‘umask’ value to determine the file
     mode and access flags.  If the file already exists, the function
     succeeds when 'exist_ok' is true (and its modification time is
     updated to the current time), otherwise *note FileExistsError:
     1222. is raised.

     Vedi anche
     ..........

     The *note open(): 2c20, *note write_text(): 1046. and *note
     write_bytes(): 1048. methods are often used to create files.

 -- Metodo: Path.mkdir (mode=0o777, parents=False, exist_ok=False)

     Create a new directory at this given path.  If 'mode' is given, it
     is combined with the process’s ‘umask’ value to determine the file
     mode and access flags.  If the path already exists, *note
     FileExistsError: 1222. is raised.

     If 'parents' is true, any missing parents of this path are created
     as needed; they are created with the default permissions without
     taking 'mode' into account (mimicking the POSIX ‘mkdir -p’
     command).

     If 'parents' is false (the default), a missing parent raises *note
     FileNotFoundError: 264.

     If 'exist_ok' is false (the default), *note FileExistsError: 1222.
     is raised if the target directory already exists.

     If 'exist_ok' is true, *note FileExistsError: 1222. will not be
     raised unless the given path already exists in the file system and
     is not a directory (same behavior as the POSIX ‘mkdir -p’ command).

     Cambiato nella versione 3.5: The 'exist_ok' parameter was added.

 -- Metodo: Path.symlink_to (target, target_is_directory=False)

     Make this path a symbolic link pointing to 'target'.

     On Windows, a symlink represents either a file or a directory, and
     does not morph to the target dynamically.  If the target is
     present, the type of the symlink will be created to match.
     Otherwise, the symlink will be created as a directory if
     'target_is_directory' is true or a file symlink (the default)
     otherwise.  On non-Windows platforms, 'target_is_directory' is
     ignored.

          >>> p = Path('mylink')
          >>> p.symlink_to('setup.py')
          >>> p.resolve()
          PosixPath('/home/antoine/pathlib/setup.py')
          >>> p.stat().st_size
          956
          >>> p.lstat().st_size
          8

          Nota: The order of arguments (link, target) is the reverse of
          *note os.symlink(): 12fc.”s.

     Cambiato nella versione 3.13: Raises *note UnsupportedOperation:
     534. if *note os.symlink(): 12fc. is not available.  In previous
     versions, *note NotImplementedError: 36b. was raised.

 -- Metodo: Path.hardlink_to (target)

     Make this path a hard link to the same file as 'target'.

          Nota: The order of arguments (link, target) is the reverse of
          *note os.link(): 12f7.”s.

     Added in version 3.10.

     Cambiato nella versione 3.13: Raises *note UnsupportedOperation:
     534. if *note os.link(): 12f7. is not available.  In previous
     versions, *note NotImplementedError: 36b. was raised.


File: python.info,  Node: Copying moving and deleting,  Next: Permissions and ownership,  Prev: Creating files and directories,  Up: Concrete paths

5.11.1.15 Copying, moving and deleting
......................................

 -- Metodo: Path.copy (target, *, follow_symlinks=True,
          preserve_metadata=False)

     Copy this file or directory tree to the given 'target', and return
     a new ‘Path’ instance pointing to 'target'.

     If the source is a file, the target will be replaced if it is an
     existing file.  If the source is a symlink and 'follow_symlinks' is
     true (the default), the symlink’s target is copied.  Otherwise, the
     symlink is recreated at the destination.

     If 'preserve_metadata' is false (the default), only directory
     structures and file data are guaranteed to be copied.  Set
     'preserve_metadata' to true to ensure that file and directory
     permissions, flags, last access and modification times, and
     extended attributes are copied where supported.  This argument has
     no effect when copying files on Windows (where metadata is always
     preserved).

          Nota: Where supported by the operating system and file system,
          this method performs a lightweight copy, where data blocks are
          only copied when modified.  This is known as copy-on-write.

     Added in version 3.14.

 -- Metodo: Path.copy_into (target_dir, *, follow_symlinks=True,
          preserve_metadata=False)

     Copy this file or directory tree into the given 'target_dir', which
     should be an existing directory.  Other arguments are handled
     identically to *note Path.copy(): 267.  Returns a new ‘Path’
     instance pointing to the copy.

     Added in version 3.14.

 -- Metodo: Path.rename (target)

     Rename this file or directory to the given 'target', and return a
     new ‘Path’ instance pointing to 'target'.  On Unix, if 'target'
     exists and is a file, it will be replaced silently if the user has
     permission.  On Windows, if 'target' exists, *note FileExistsError:
     1222. will be raised.  'target' can be either a string or another
     path object:

          >>> p = Path('foo')
          >>> p.open('w').write('some text')
          9
          >>> target = Path('bar')
          >>> p.rename(target)
          PosixPath('bar')
          >>> target.open().read()
          'some text'

     The target path may be absolute or relative.  Relative paths are
     interpreted relative to the current working directory, 'not' the
     directory of the ‘Path’ object.

     It is implemented in terms of *note os.rename(): 12f9. and gives
     the same guarantees.

     Cambiato nella versione 3.8: Added return value, return the new
     ‘Path’ instance.

 -- Metodo: Path.replace (target)

     Rename this file or directory to the given 'target', and return a
     new ‘Path’ instance pointing to 'target'.  If 'target' points to an
     existing file or empty directory, it will be unconditionally
     replaced.

     The target path may be absolute or relative.  Relative paths are
     interpreted relative to the current working directory, 'not' the
     directory of the ‘Path’ object.

     Cambiato nella versione 3.8: Added return value, return the new
     ‘Path’ instance.

 -- Metodo: Path.move (target)

     Move this file or directory tree to the given 'target', and return
     a new ‘Path’ instance pointing to 'target'.

     If the 'target' doesn’t exist it will be created.  If both this
     path and the 'target' are existing files, then the target is
     overwritten.  If both paths point to the same file or directory, or
     the 'target' is a non-empty directory, then *note OSError: 2c0. is
     raised.

     If both paths are on the same filesystem, the move is performed
     with *note os.replace(): 12fa.  Otherwise, this path is copied
     (preserving metadata and symlinks) and then deleted.

     Added in version 3.14.

 -- Metodo: Path.move_into (target_dir)

     Move this file or directory tree into the given 'target_dir', which
     should be an existing directory.  Returns a new ‘Path’ instance
     pointing to the moved path.

     Added in version 3.14.

 -- Metodo: Path.unlink (missing_ok=False)

     Remove this file or symbolic link.  If the path points to a
     directory, use *note Path.rmdir(): 2c22. instead.

     If 'missing_ok' is false (the default), *note FileNotFoundError:
     264. is raised if the path does not exist.

     If 'missing_ok' is true, *note FileNotFoundError: 264. exceptions
     will be ignored (same behavior as the POSIX ‘rm -f’ command).

     Cambiato nella versione 3.8: The 'missing_ok' parameter was added.

 -- Metodo: Path.rmdir ()

     Remove this directory.  The directory must be empty.


File: python.info,  Node: Permissions and ownership,  Prev: Copying moving and deleting,  Up: Concrete paths

5.11.1.16 Permissions and ownership
...................................

 -- Metodo: Path.owner (*, follow_symlinks=True)

     Return the name of the user owning the file.  *note KeyError: 5e7.
     is raised if the file’s user identifier (UID) isn’t found in the
     system database.

     This method normally follows symlinks; to get the owner of the
     symlink, add the argument ‘follow_symlinks=False’.

     Cambiato nella versione 3.13: Raises *note UnsupportedOperation:
     534. if the *note pwd: b7. module is not available.  In earlier
     versions, *note NotImplementedError: 36b. was raised.

     Cambiato nella versione 3.13: The 'follow_symlinks' parameter was
     added.

 -- Metodo: Path.group (*, follow_symlinks=True)

     Return the name of the group owning the file.  *note KeyError: 5e7.
     is raised if the file’s group identifier (GID) isn’t found in the
     system database.

     This method normally follows symlinks; to get the group of the
     symlink, add the argument ‘follow_symlinks=False’.

     Cambiato nella versione 3.13: Raises *note UnsupportedOperation:
     534. if the *note grp: 6a. module is not available.  In earlier
     versions, *note NotImplementedError: 36b. was raised.

     Cambiato nella versione 3.13: The 'follow_symlinks' parameter was
     added.

 -- Metodo: Path.chmod (mode, *, follow_symlinks=True)

     Change the file mode and permissions, like *note os.chmod(): 52a.

     This method normally follows symlinks.  Some Unix flavours support
     changing permissions on the symlink itself; on these platforms you
     may add the argument ‘follow_symlinks=False’, or use *note
     lchmod(): 2c28.

          >>> p = Path('setup.py')
          >>> p.stat().st_mode
          33277
          >>> p.chmod(0o444)
          >>> p.stat().st_mode
          33060

     Cambiato nella versione 3.10: The 'follow_symlinks' parameter was
     added.

 -- Metodo: Path.lchmod (mode)

     Like *note Path.chmod(): a27. but, if the path points to a symbolic
     link, the symbolic link’s mode is changed rather than its target’s.


File: python.info,  Node: Pattern language,  Next: Comparison to the glob module,  Prev: Concrete paths,  Up: pathlib — Object-oriented filesystem paths

5.11.1.17 Pattern language
..........................

The following wildcards are supported in patterns for *note
full_match(): 536, *note glob(): 538. and *note rglob(): 539.:

‘**’ (entire segment)

     Matches any number of file or directory segments, including zero.

‘*’ (entire segment)

     Matches one file or directory segment.

‘*’ (part of a segment)

     Matches any number of non-separator characters, including zero.

‘?’

     Matches one non-separator character.

‘[seq]’

     Matches one character in 'seq', where 'seq' is a sequence of
     characters.  Range expressions are supported; for example, ‘[a-z]’
     matches any lowercase ASCII letter.  Multiple ranges can be
     combined: ‘[a-zA-Z0-9_]’ matches any ASCII letter, digit, or
     underscore.

‘[!seq]’

     Matches one character not in 'seq', where 'seq' follows the same
     rules as above.

For a literal match, wrap the meta-characters in brackets.  For example,
‘"[?]"’ matches the character ‘"?"’.

The «‘**’» wildcard enables recursive globbing.  A few examples:

Pattern                       Meaning
                              
--------------------------------------------------------------------------------------------------------
                              
«‘**/*’»                      Any path with at least one segment.
                              
                              
«‘**/*.py’»                   Any path with a final segment ending «‘.py’».
                              
                              
«‘assets/**’»                 Any path starting with «‘assets/’».
                              
                              
«‘assets/**/*’»               Any path starting with «‘assets/’», excluding «‘assets/’» itself.
                              

     Nota: Globbing with the «‘**’» wildcard visits every directory in
     the tree.  Large directory trees may take a long time to search.

Cambiato nella versione 3.13: Globbing with a pattern that ends with
«‘**’» returns both files and directories.  In previous versions, only
directories were returned.

In *note Path.glob(): 538. and *note rglob(): 539, a trailing slash may
be added to the pattern to match only directories.

Cambiato nella versione 3.11: Globbing with a pattern that ends with a
pathname components separator (*note sep: 87b. or *note altsep: 87c.)
returns only directories.


File: python.info,  Node: Comparison to the glob module,  Next: Comparison to the os and os path modules,  Prev: Pattern language,  Up: pathlib — Object-oriented filesystem paths

5.11.1.18 Comparison to the ‘glob’ module
.........................................

The patterns accepted and results generated by *note Path.glob(): 538.
and *note Path.rglob(): 539. differ slightly from those by the *note
glob: 68. module:

  1. Files beginning with a dot are not special in pathlib.  This is
     like passing ‘include_hidden=True’ to *note glob.glob(): 5a0.

  2. «‘**’» pattern components are always recursive in pathlib.  This is
     like passing ‘recursive=True’ to *note glob.glob(): 5a0.

  3. «‘**’» pattern components do not follow symlinks by default in
     pathlib.  This behaviour has no equivalent in *note glob.glob():
     5a0, but you can pass ‘recurse_symlinks=True’ to *note Path.glob():
     538. for compatible behaviour.

  4. Like all *note PurePath: 6ce. and *note Path: 266. objects, the
     values returned from *note Path.glob(): 538. and *note
     Path.rglob(): 539. don’t include trailing slashes.

  5. The values returned from pathlib’s ‘path.glob()’ and ‘path.rglob()’
     include the 'path' as a prefix, unlike the results of
     ‘glob.glob(root_dir=path)’.

  6. The values returned from pathlib’s ‘path.glob()’ and ‘path.rglob()’
     may include 'path' itself, for example when globbing «‘**’»,
     whereas the results of ‘glob.glob(root_dir=path)’ never include an
     empty string that would correspond to 'path'.


File: python.info,  Node: Comparison to the os and os path modules,  Next: Protocols,  Prev: Comparison to the glob module,  Up: pathlib — Object-oriented filesystem paths

5.11.1.19 Comparison to the ‘os’ and ‘os.path’ modules
......................................................

pathlib implements path operations using *note PurePath: 6ce. and *note
Path: 266. objects, and so it’s said to be 'object-oriented'.  On the
other hand, the *note os: a5. and *note os.path: a6. modules supply
functions that work with low-level ‘str’ and ‘bytes’ objects, which is a
more 'procedural' approach.  Some users consider the object-oriented
style to be more readable.

Many functions in *note os: a5. and *note os.path: a6. support ‘bytes’
paths and *note paths relative to directory descriptors: 12f2.  These
features aren’t available in pathlib.

Python’s ‘str’ and ‘bytes’ types, and portions of the *note os: a5. and
*note os.path: a6. modules, are written in C and are very speedy.
pathlib is written in pure Python and is often slower, but rarely slow
enough to matter.

pathlib’s path normalization is slightly more opinionated and consistent
than *note os.path: a6.  For example, whereas *note os.path.abspath():
1522. eliminates «‘..’» segments from a path, which may change its
meaning if symlinks are involved, *note Path.absolute(): 1a0e. preserves
these segments for greater safety.

pathlib’s path normalization may render it unsuitable for some
applications:

  1. pathlib normalizes ‘Path("my_folder/")’ to ‘Path("my_folder")’,
     which changes a path’s meaning when supplied to various operating
     system APIs and command-line utilities.  Specifically, the absence
     of a trailing separator may allow the path to be resolved as either
     a file or directory, rather than a directory only.

  2. pathlib normalizes ‘Path("./my_program")’ to ‘Path("my_program")’,
     which changes a path’s meaning when used as an executable search
     path, such as in a shell or when spawning a child process.
     Specifically, the absence of a separator in the path may force it
     to be looked up in ‘PATH’ rather than the current directory.

As a consequence of these differences, pathlib is not a drop-in
replacement for *note os.path: a6.

* Menu:

* Corresponding tools::


File: python.info,  Node: Corresponding tools,  Up: Comparison to the os and os path modules

5.11.1.20 Corresponding tools
.............................

Below is a table mapping various *note os: a5. functions to their
corresponding *note PurePath: 6ce./*note Path: 266. equivalent.

*note os: a5. and *note os.path: a6.      *note pathlib: a8.
                                          
---------------------------------------------------------------------------------------------
                                          
*note os.path.dirname(): 2c2d.            *note PurePath.parent: 1a85.
                                          
                                          
*note os.path.basename(): 2c2e.           *note PurePath.name: 2c13.
                                          
                                          
*note os.path.splitext(): 1941.           *note PurePath.stem: 2c14,
                                          *note PurePath.suffix: 193f.
                                          
                                          
*note os.path.join(): 1991.               *note PurePath.joinpath(): 2c16.
                                          
                                          
*note os.path.isabs(): 532.               *note PurePath.is_absolute(): 1a84.
                                          
                                          
*note os.path.relpath(): 6d2.             *note PurePath.relative_to(): 2fd. (1)
                                          
                                          
*note os.path.expanduser(): c0b.          *note Path.expanduser(): 1044. (2)
                                          
                                          
*note os.path.realpath(): 262.            *note Path.resolve(): 1a55.
                                          
                                          
*note os.path.abspath(): 1522.            *note Path.absolute(): 1a0e. (3)
                                          
                                          
*note os.path.exists(): c05.              *note Path.exists(): c0d.
                                          
                                          
*note os.path.isfile(): c08.              *note Path.is_file(): 53a.
                                          
                                          
*note os.path.isdir(): c07.               *note Path.is_dir(): 53b.
                                          
                                          
*note os.path.islink(): c03.              *note Path.is_symlink(): c0f.
                                          
                                          
*note os.path.isjunction(): 6cb.          *note Path.is_junction(): 6d3.
                                          
                                          
*note os.path.ismount(): c09.             *note Path.is_mount(): c0e.
                                          
                                          
*note os.path.samefile(): 1173.           *note Path.samefile(): 1042.
                                          
                                          
*note os.getcwd(): 18f1.                  *note Path.cwd(): 1a83.
                                          
                                          
*note os.stat(): 26d.                     *note Path.stat(): a26.
                                          
                                          
*note os.lstat(): 6c9.                    *note Path.lstat(): 2c1e.
                                          
                                          
*note os.listdir(): 1302.                 *note Path.iterdir(): 26e.
                                          
                                          
*note os.walk(): 6d1.                     *note Path.walk(): 6d0. (4)
                                          
                                          
*note os.mkdir(): 52c,                    *note Path.mkdir(): 1043.
*note os.makedirs(): 52d.                 

*note os.link(): 12f7.                    *note Path.hardlink_to(): a24.
                                          
                                          
*note os.symlink(): 12fc.                 *note Path.symlink_to(): a25.
                                          
                                          
*note os.readlink(): b1c.                 *note Path.readlink(): b1b.
                                          
                                          
*note os.rename(): 12f9.                  *note Path.rename(): 1879.
                                          
                                          
*note os.replace(): 12fa.                 *note Path.replace(): 2c26.
                                          
                                          
*note os.remove(): 12f8,                  *note Path.unlink(): 1dbd.
*note os.unlink(): 12fd.                  

*note os.rmdir(): 12fb.                   *note Path.rmdir(): 2c22.
                                          
                                          
*note os.chmod(): 52a.                    *note Path.chmod(): a27.
                                          
                                          
*note os.lchmod(): 529.                   *note Path.lchmod(): 2c28.
                                          

   ---------- Footnotes ----------

   (1) *note os.path.relpath(): 6d2. calls *note abspath(): 1522. to
make paths absolute and remove «‘..’» parts, whereas *note
PurePath.relative_to(): 2fd. is a lexical operation that raises *note
ValueError: 2ec. when its inputs” anchors differ (e.g.  if one path is
absolute and the other relative.)

   (2) *note os.path.expanduser(): c0b. returns the path unchanged if
the home directory can’t be resolved, whereas *note Path.expanduser():
1044. raises *note RuntimeError: 244.

   (3) *note os.path.abspath(): 1522. removes «‘..’» components without
resolving symlinks, which may change the meaning of the path, whereas
*note Path.absolute(): 1a0e. leaves any «‘..’» components in the path.

   (4) *note os.walk(): 6d1. always follows symlinks when categorizing
paths into 'dirnames' and 'filenames', whereas *note Path.walk(): 6d0.
categorizes all symlinks into 'filenames' when 'follow_symlinks' is
false (the default.)


File: python.info,  Node: Protocols,  Prev: Comparison to the os and os path modules,  Up: pathlib — Object-oriented filesystem paths

5.11.1.21 Protocols
...................

The *note pathlib.types: a9. module provides types for static type
checking.

Added in version 3.14.

 -- Classe: pathlib.types.PathInfo

     A *note typing.Protocol: 56b. describing the *note Path.info: 26b.
     attribute.  Implementations may return cached results from their
     methods.

      -- Metodo: exists (*, follow_symlinks=True)

          Return ‘True’ if the path is an existing file or directory, or
          any other kind of file; return ‘False’ if the path doesn’t
          exist.

          If 'follow_symlinks' is ‘False’, return ‘True’ for symlinks
          without checking if their targets exist.

      -- Metodo: is_dir (*, follow_symlinks=True)

          Return ‘True’ if the path is a directory, or a symbolic link
          pointing to a directory; return ‘False’ if the path is (or
          points to) any other kind of file, or if it doesn’t exist.

          If 'follow_symlinks' is ‘False’, return ‘True’ only if the
          path is a directory (without following symlinks); return
          ‘False’ if the path is any other kind of file, or if it
          doesn’t exist.

      -- Metodo: is_file (*, follow_symlinks=True)

          Return ‘True’ if the path is a file, or a symbolic link
          pointing to a file; return ‘False’ if the path is (or points
          to) a directory or other non-file, or if it doesn’t exist.

          If 'follow_symlinks' is ‘False’, return ‘True’ only if the
          path is a file (without following symlinks); return ‘False’ if
          the path is a directory or other non-file, or if it doesn’t
          exist.

      -- Metodo: is_symlink ()

          Return ‘True’ if the path is a symbolic link (even if broken);
          return ‘False’ if the path is a directory or any kind of file,
          or if it doesn’t exist.


File: python.info,  Node: os path — Common pathname manipulations,  Next: stat — Interpreting stat results,  Prev: pathlib — Object-oriented filesystem paths,  Up: File and Directory Access

5.11.2 ‘os.path’ — Common pathname manipulations
------------------------------------------------

'Source code:' Lib/genericpath.py(1), Lib/posixpath.py(2) (for POSIX)
and Lib/ntpath.py(3) (for Windows).

__________________________________________________________________

This module implements some useful functions on pathnames.  To read or
write files see *note open(): 316, and for accessing the filesystem see
the *note os: a5. module.  The path parameters can be passed as strings,
or bytes, or any object implementing the *note os.PathLike: e4d.
protocol.

Unlike a Unix shell, Python does not do any 'automatic' path expansions.
Functions such as *note expanduser(): c0b. and *note expandvars(): 15e0.
can be invoked explicitly when an application desires shell-like path
expansion.  (See also the *note glob: 68. module.)

Vedi anche
..........

The *note pathlib: a8. module offers high-level path objects.

     Nota: All of these functions accept either only bytes or only
     string objects as their parameters.  The result is an object of the
     same type, if a path or file name is returned.

     Nota: Since different operating systems have different path name
     conventions, there are several versions of this module in the
     standard library.  The *note os.path: a6. module is always the path
     module suitable for the operating system Python is running on, and
     therefore usable for local paths.  However, you can also import and
     use the individual modules if you want to manipulate a path that is
     'always' in one of the different formats.  They all have the same
     interface:

        * ‘posixpath’ for UNIX-style paths

        * ‘ntpath’ for Windows paths

Cambiato nella versione 3.8: *note exists(): c05, *note lexists(): c06,
*note isdir(): c07, *note isfile(): c08, *note islink(): c03, and *note
ismount(): c09. now return ‘False’ instead of raising an exception for
paths that contain characters or bytes unrepresentable at the OS level.

 -- Funzione: os.path.abspath (path)

     Return a normalized absolutized version of the pathname 'path'.  On
     most platforms, this is equivalent to calling
     ‘normpath(join(os.getcwd(), path))’.

     Vedi anche
     ..........

     *note os.path.join(): 1991. and *note os.path.normpath(): 1521.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.basename (path, /)

     Return the base name of pathname 'path'.  This is the second
     element of the pair returned by passing 'path' to the function
     *note split(): 2c37.  Note that the result of this function is
     different from the Unix ‘basename’ program; where ‘basename’ for
     ‘'/foo/bar/'’ returns ‘'bar'’, the *note basename(): 2c2e. function
     returns an empty string (‘''’).

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.commonpath (paths)

     Return the longest common sub-path of each pathname in the iterable
     'paths'.  Raise *note ValueError: 2ec. if 'paths' contain both
     absolute and relative pathnames, if 'paths' are on different
     drives, or if 'paths' is empty.  Unlike *note commonprefix(): 1040,
     this returns a valid path.

     Added in version 3.5.

     Cambiato nella versione 3.6: Accepts a sequence of *note path-like
     objects: 5a1.

     Cambiato nella versione 3.13: Any iterable can now be passed,
     rather than just sequences.

 -- Funzione: os.path.commonprefix (list, /)

     Return the longest path prefix (taken character-by-character) that
     is a prefix of all paths in 'list'.  If 'list' is empty, return the
     empty string (‘''’).

          Nota: This function may return invalid paths because it works
          a character at a time.  To obtain a valid path, see *note
          commonpath(): 103f.

               >>> os.path.commonprefix(['/usr/lib', '/usr/local/lib'])
               '/usr/l'

               >>> os.path.commonpath(['/usr/lib', '/usr/local/lib'])
               '/usr'

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.dirname (path, /)

     Return the directory name of pathname 'path'.  This is the first
     element of the pair returned by passing 'path' to the function
     *note split(): 2c37.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.exists (path)

     Return ‘True’ if 'path' refers to an existing path or an open file
     descriptor.  Returns ‘False’ for broken symbolic links.  On some
     platforms, this function may return ‘False’ if permission is not
     granted to execute *note os.stat(): 26d. on the requested file,
     even if the 'path' physically exists.

     Cambiato nella versione 3.3: 'path' can now be an integer: ‘True’
     is returned if it is an open file descriptor, ‘False’ otherwise.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.lexists (path)

     Return ‘True’ if 'path' refers to an existing path, including
     broken symbolic links.  Equivalent to *note exists(): c05. on
     platforms lacking *note os.lstat(): 6c9.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.expanduser (path)

     On Unix and Windows, return the argument with an initial component
     of ‘~’ or ‘~user’ replaced by that 'user'’s home directory.

     On Unix, an initial ‘~’ is replaced by the environment variable
     ‘HOME’ if it is set; otherwise the current user’s home directory is
     looked up in the password directory through the built-in module
     *note pwd: b7.  An initial ‘~user’ is looked up directly in the
     password directory.

     On Windows, ‘USERPROFILE’ will be used if set, otherwise a
     combination of ‘HOMEPATH’ and ‘HOMEDRIVE’ will be used.  An initial
     ‘~user’ is handled by checking that the last directory component of
     the current user’s home directory matches ‘USERNAME’, and replacing
     it if so.

     If the expansion fails or if the path does not begin with a tilde,
     the path is returned unchanged.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.8: No longer uses ‘HOME’ on Windows.

 -- Funzione: os.path.expandvars (path)

     Return the argument with environment variables expanded.
     Substrings of the form ‘$name’ or ‘${name}’ are replaced by the
     value of environment variable 'name'.  Malformed variable names and
     references to non-existing variables are left unchanged.

     On Windows, ‘%name%’ expansions are supported in addition to
     ‘$name’ and ‘${name}’.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.getatime (path, /)

     Return the time of last access of 'path'.  The return value is a
     floating-point number giving the number of seconds since the epoch
     (see the *note time: f4. module).  Raise *note OSError: 2c0. if the
     file does not exist or is inaccessible.

 -- Funzione: os.path.getmtime (path, /)

     Return the time of last modification of 'path'.  The return value
     is a floating-point number giving the number of seconds since the
     epoch (see the *note time: f4. module).  Raise *note OSError: 2c0.
     if the file does not exist or is inaccessible.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.getctime (path, /)

     Return the system’s ctime which, on some systems (like Unix) is the
     time of the last metadata change, and, on others (like Windows), is
     the creation time for 'path'.  The return value is a number giving
     the number of seconds since the epoch (see the *note time: f4.
     module).  Raise *note OSError: 2c0. if the file does not exist or
     is inaccessible.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.getsize (path, /)

     Return the size, in bytes, of 'path'.  Raise *note OSError: 2c0. if
     the file does not exist or is inaccessible.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.isabs (path, /)

     Return ‘True’ if 'path' is an absolute pathname.  On Unix, that
     means it begins with a slash, on Windows that it begins with two
     (back)slashes, or a drive letter, colon, and (back)slash together.

     Vedi anche
     ..........

     *note abspath(): 1522.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.13: On Windows, returns ‘False’ if the
     given path starts with exactly one (back)slash.

 -- Funzione: os.path.isfile (path)

     Return ‘True’ if 'path' is an *note existing: c05. regular file.
     This follows symbolic links, so both *note islink(): c03. and *note
     isfile(): c08. can be true for the same path.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.isdir (path, /)

     Return ‘True’ if 'path' is an *note existing: c05. directory.  This
     follows symbolic links, so both *note islink(): c03. and *note
     isdir(): c07. can be true for the same path.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.isjunction (path)

     Return ‘True’ if 'path' refers to an *note existing: c06. directory
     entry that is a junction.  Always return ‘False’ if junctions are
     not supported on the current platform.

     Added in version 3.12.

 -- Funzione: os.path.islink (path)

     Return ‘True’ if 'path' refers to an *note existing: c05. directory
     entry that is a symbolic link.  Always ‘False’ if symbolic links
     are not supported by the Python runtime.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.ismount (path)

     Return ‘True’ if pathname 'path' is a 'mount point': a point in a
     file system where a different file system has been mounted.  On
     POSIX, the function checks whether 'path'’s parent, ‘`path'/..’, is
     on a different device than 'path', or whether ‘`path'/..’ and
     'path' point to the same i-node on the same device — this should
     detect mount points for all Unix and POSIX variants.  It is not
     able to reliably detect bind mounts on the same filesystem.  On
     Linux systems, it will always return ‘True’ for btrfs subvolumes,
     even if they aren’t mount points.  On Windows, a drive letter root
     and a share UNC are always mount points, and for any other path
     ‘GetVolumePathName’ is called to see if it is different from the
     input path.

     Cambiato nella versione 3.4: Added support for detecting non-root
     mount points on Windows.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.isdevdrive (path)

     Return ‘True’ if pathname 'path' is located on a Windows Dev Drive.
     A Dev Drive is optimized for developer scenarios, and offers faster
     performance for reading and writing files.  It is recommended for
     use for source code, temporary build directories, package caches,
     and other IO-intensive operations.

     May raise an error for an invalid path, for example, one without a
     recognizable drive, but returns ‘False’ on platforms that do not
     support Dev Drives.  See the Windows documentation(4) for
     information on enabling and creating Dev Drives.

     Added in version 3.12.

     Cambiato nella versione 3.13: The function is now available on all
     platforms, and will always return ‘False’ on those that have no
     support for Dev Drives

 -- Funzione: os.path.isreserved (path)

     Return ‘True’ if 'path' is a reserved pathname on the current
     system.

     On Windows, reserved filenames include those that end with a space
     or dot; those that contain colons (i.e.  file streams such as
     «name:stream»), wildcard characters (i.e.  ‘'*?"<>'’), pipe, or
     ASCII control characters; as well as DOS device names such as
     «NUL», «CON», «CONIN$», «CONOUT$», «AUX», «PRN», «COM1», and
     «LPT1».

          Nota: This function approximates rules for reserved paths on
          most Windows systems.  These rules change over time in various
          Windows releases.  This function may be updated in future
          Python releases as changes to the rules become broadly
          available.

     *note Availability: 2128.: Windows.

     Added in version 3.13.

 -- Funzione: os.path.join (path, /, *paths)

     Join one or more path segments intelligently.  The return value is
     the concatenation of 'path' and all members of '*paths', with
     exactly one directory separator following each non-empty part,
     except the last.  That is, the result will only end in a separator
     if the last part is either empty or ends in a separator.

     If a segment is an absolute path (which on Windows requires both a
     drive and a root), then all previous segments are ignored and
     joining continues from the absolute path segment.  On Linux, for
     example:

          >>> os.path.join('/home/foo', 'bar')
          '/home/foo/bar'
          >>> os.path.join('/home/foo', '/home/bar')
          '/home/bar'

     On Windows, the drive is not reset when a rooted path segment
     (e.g., ‘r'\foo'’) is encountered.  If a segment is on a different
     drive or is an absolute path, all previous segments are ignored and
     the drive is reset.  For example:

          >>> os.path.join('c:\\', 'foo')
          'c:\\foo'
          >>> os.path.join('c:\\foo', 'd:\\bar')
          'd:\\bar'

     Note that since there is a current directory for each drive,
     ‘os.path.join("c:", "foo")’ represents a path relative to the
     current directory on drive ‘C:’ (‘c:foo’), not ‘c:\foo’.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.
     for 'path' and 'paths'.

 -- Funzione: os.path.normcase (path, /)

     Normalize the case of a pathname.  On Windows, convert all
     characters in the pathname to lowercase, and also convert forward
     slashes to backward slashes.  On other operating systems, return
     the path unchanged.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.normpath (path)

     Normalize a pathname by collapsing redundant separators and
     up-level references so that ‘A//B’, ‘A/B/’, ‘A/./B’ and
     ‘A/foo/../B’ all become ‘A/B’.  This string manipulation may change
     the meaning of a path that contains symbolic links.  On Windows, it
     converts forward slashes to backward slashes.  To normalize case,
     use *note normcase(): 2c3c.

          Nota: On POSIX systems, in accordance with IEEE Std 1003.1
          2013 Edition; 4.13 Pathname Resolution(5), if a pathname
          begins with exactly two slashes, the first component following
          the leading characters may be interpreted in an
          implementation-defined manner, although more than two leading
          characters shall be treated as a single character.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.realpath (path, /, *, strict=False)

     Return the canonical path of the specified filename, eliminating
     any symbolic links encountered in the path (if they are supported
     by the operating system).  On Windows, this function will also
     resolve MS-DOS (also called 8.3) style names such as ‘C:\\PROGRA~1’
     to ‘C:\\Program Files’.

     By default, the path is evaluated up to the first component that
     does not exist, is a symlink loop, or whose evaluation raises *note
     OSError: 2c0.  All such components are appended unchanged to the
     existing part of the path.

     Some errors that are handled this way include «access denied», «not
     a directory», or «bad argument to internal function».  Thus, the
     resulting path may be missing or inaccessible, may still contain
     links or loops, and may traverse non-directories.

     This behavior can be modified by keyword arguments:

     If 'strict' is ‘True’, the first error encountered when evaluating
     the path is re-raised.  In particular, *note FileNotFoundError:
     264. is raised if 'path' does not exist, or another *note OSError:
     2c0. if it is otherwise inaccessible.

     If 'strict' is *note os.path.ALLOW_MISSING: 263, errors other than
     *note FileNotFoundError: 264. are re-raised (as with
     ‘strict=True’).  Thus, the returned path will not contain any
     symbolic links, but the named file and some of its parent
     directories may be missing.

          Nota: This function emulates the operating system’s procedure
          for making a path canonical, which differs slightly between
          Windows and UNIX with respect to how links and subsequent path
          components interact.

          Operating system APIs make paths canonical as needed, so it’s
          not normally necessary to call this function.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.8: Symbolic links and junctions are now
     resolved on Windows.

     Cambiato nella versione 3.10: The 'strict' parameter was added.

     Cambiato nella versione 3.14: The *note ALLOW_MISSING: 263. value
     for the 'strict' parameter was added.

 -- Dati: os.path.ALLOW_MISSING

     Special value used for the 'strict' argument in *note realpath():
     262.

     Added in version 3.14.

 -- Funzione: os.path.relpath (path, start=os.curdir)

     Return a relative filepath to 'path' either from the current
     directory or from an optional 'start' directory.  This is a path
     computation: the filesystem is not accessed to confirm the
     existence or nature of 'path' or 'start'.  On Windows, *note
     ValueError: 2ec. is raised when 'path' and 'start' are on different
     drives.

     'start' defaults to *note os.curdir: 2c3d.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.samefile (path1, path2, /)

     Return ‘True’ if both pathname arguments refer to the same file or
     directory.  This is determined by the device number and i-node
     number and raises an exception if an *note os.stat(): 26d. call on
     either pathname fails.

     Cambiato nella versione 3.2: Added Windows support.

     Cambiato nella versione 3.4: Windows now uses the same
     implementation as all other platforms.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.sameopenfile (fp1, fp2)

     Return ‘True’ if the file descriptors 'fp1' and 'fp2' refer to the
     same file.

     Cambiato nella versione 3.2: Added Windows support.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.samestat (stat1, stat2, /)

     Return ‘True’ if the stat tuples 'stat1' and 'stat2' refer to the
     same file.  These structures may have been returned by *note
     os.fstat(): f8e, *note os.lstat(): 6c9, or *note os.stat(): 26d.
     This function implements the underlying comparison used by *note
     samefile(): 1173. and *note sameopenfile(): 2c3e.

     Cambiato nella versione 3.4: Added Windows support.

 -- Funzione: os.path.split (path, /)

     Split the pathname 'path' into a pair, ‘(head, tail)’ where 'tail'
     is the last pathname component and 'head' is everything leading up
     to that.  The 'tail' part will never contain a slash; if 'path'
     ends in a slash, 'tail' will be empty.  If there is no slash in
     'path', 'head' will be empty.  If 'path' is empty, both 'head' and
     'tail' are empty.  Trailing slashes are stripped from 'head' unless
     it is the root (one or more slashes only).  In all cases,
     ‘join(head, tail)’ returns a path to the same location as 'path'
     (but the strings may differ).  Also see the functions *note join():
     1991, *note dirname(): 2c2d. and *note basename(): 2c2e.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.splitdrive (path, /)

     Split the pathname 'path' into a pair ‘(drive, tail)’ where 'drive'
     is either a mount point or the empty string.  On systems which do
     not use drive specifications, 'drive' will always be the empty
     string.  In all cases, ‘drive + tail’ will be the same as 'path'.

     On Windows, splits a pathname into drive/UNC sharepoint and
     relative path.

     If the path contains a drive letter, drive will contain everything
     up to and including the colon:

          >>> splitdrive("c:/dir")
          ("c:", "/dir")

     If the path contains a UNC path, drive will contain the host name
     and share:

          >>> splitdrive("//host/computer/dir")
          ("//host/computer", "/dir")

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.path.splitroot (path, /)

     Split the pathname 'path' into a 3-item tuple ‘(drive, root, tail)’
     where 'drive' is a device name or mount point, 'root' is a string
     of separators after the drive, and 'tail' is everything after the
     root.  Any of these items may be the empty string.  In all cases,
     ‘drive + root + tail’ will be the same as 'path'.

     On POSIX systems, 'drive' is always empty.  The 'root' may be empty
     (if 'path' is relative), a single forward slash (if 'path' is
     absolute), or two forward slashes (implementation-defined per IEEE
     Std 1003.1-2017; 4.13 Pathname Resolution(6).)  For example:

          >>> splitroot('/home/sam')
          ('', '/', 'home/sam')
          >>> splitroot('//home/sam')
          ('', '//', 'home/sam')
          >>> splitroot('///home/sam')
          ('', '/', '//home/sam')

     On Windows, 'drive' may be empty, a drive-letter name, a UNC share,
     or a device name.  The 'root' may be empty, a forward slash, or a
     backward slash.  For example:

          >>> splitroot('C:/Users/Sam')
          ('C:', '/', 'Users/Sam')
          >>> splitroot('//Server/Share/Users/Sam')
          ('//Server/Share', '/', 'Users/Sam')

     Added in version 3.12.

 -- Funzione: os.path.splitext (path, /)

     Split the pathname 'path' into a pair ‘(root, ext)’ such that ‘root
     + ext == path’, and the extension, 'ext', is empty or begins with a
     period and contains at most one period.

     If the path contains no extension, 'ext' will be ‘''’:

          >>> splitext('bar')
          ('bar', '')

     If the path contains an extension, then 'ext' will be set to this
     extension, including the leading period.  Note that previous
     periods will be ignored:

          >>> splitext('foo.bar.exe')
          ('foo.bar', '.exe')
          >>> splitext('/foo/bar.exe')
          ('/foo/bar', '.exe')

     Leading periods of the last component of the path are considered to
     be part of the root:

          >>> splitext('.cshrc')
          ('.cshrc', '')
          >>> splitext('/foo/....jpg')
          ('/foo/....jpg', '')

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Dati: os.path.supports_unicode_filenames

     ‘True’ if arbitrary Unicode strings can be used as file names
     (within limitations imposed by the file system).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/genericpath.py

   (2) https://github.com/python/cpython/tree/3.14/Lib/posixpath.py

   (3) https://github.com/python/cpython/tree/3.14/Lib/ntpath.py

   (4) https://learn.microsoft.com/windows/dev-drive/

   (5) 
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13

   (6) 
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13


File: python.info,  Node: stat — Interpreting stat results,  Next: filecmp — File and Directory Comparisons,  Prev: os path — Common pathname manipulations,  Up: File and Directory Access

5.11.3 ‘stat’ — Interpreting ‘stat()’ results
---------------------------------------------

'Source code:' Lib/stat.py(1)

__________________________________________________________________

The *note stat: d6. module defines constants and functions for
interpreting the results of *note os.stat(): 26d, *note os.fstat(): f8e.
and *note os.lstat(): 6c9. (if they exist).  For complete details about
the ‘stat()’, ‘fstat()’ and ‘lstat()’ calls, consult the documentation
for your system.

Cambiato nella versione 3.4: The stat module is backed by a C
implementation.

The *note stat: d6. module defines the following functions to test for
specific file types:

 -- Funzione: stat.S_ISDIR (mode)

     Return non-zero if the mode is from a directory.

 -- Funzione: stat.S_ISCHR (mode)

     Return non-zero if the mode is from a character special device
     file.

 -- Funzione: stat.S_ISBLK (mode)

     Return non-zero if the mode is from a block special device file.

 -- Funzione: stat.S_ISREG (mode)

     Return non-zero if the mode is from a regular file.

 -- Funzione: stat.S_ISFIFO (mode)

     Return non-zero if the mode is from a FIFO (named pipe).

 -- Funzione: stat.S_ISLNK (mode)

     Return non-zero if the mode is from a symbolic link.

 -- Funzione: stat.S_ISSOCK (mode)

     Return non-zero if the mode is from a socket.

 -- Funzione: stat.S_ISDOOR (mode)

     Return non-zero if the mode is from a door.

     Added in version 3.4.

 -- Funzione: stat.S_ISPORT (mode)

     Return non-zero if the mode is from an event port.

     Added in version 3.4.

 -- Funzione: stat.S_ISWHT (mode)

     Return non-zero if the mode is from a whiteout.

     Added in version 3.4.

Two additional functions are defined for more general manipulation of
the file’s mode:

 -- Funzione: stat.S_IMODE (mode)

     Return the portion of the file’s mode that can be set by *note
     os.chmod(): 52a.—that is, the file’s permission bits, plus the
     sticky bit, set-group-id, and set-user-id bits (on systems that
     support them).

 -- Funzione: stat.S_IFMT (mode)

     Return the portion of the file’s mode that describes the file type
     (used by the ‘S_IS*()’ functions above).

Normally, you would use the ‘os.path.is*()’ functions for testing the
type of a file; the functions here are useful when you are doing
multiple tests of the same file and wish to avoid the overhead of the
‘stat()’ system call for each test.  These are also useful when checking
for information about a file that isn’t handled by *note os.path: a6,
like the tests for block and character devices.

Example:

     import os, sys
     from stat import *

     def walktree(top, callback):
         '''recursively descend the directory tree rooted at top,
            calling the callback function for each regular file'''

         for f in os.listdir(top):
             pathname = os.path.join(top, f)
             mode = os.lstat(pathname).st_mode
             if S_ISDIR(mode):
                 # It's a directory, recurse into it
                 walktree(pathname, callback)
             elif S_ISREG(mode):
                 # It's a file, call the callback function
                 callback(pathname)
             else:
                 # Unknown file type, print a message
                 print('Skipping %s' % pathname)

     def visitfile(file):
         print('visiting', file)

     if __name__ == '__main__':
         walktree(sys.argv[1], visitfile)

An additional utility function is provided to convert a file’s mode in a
human readable string:

 -- Funzione: stat.filemode (mode)

     Convert a file’s mode to a string of the form “-rwxrwxrwx”.

     Added in version 3.3.

     Cambiato nella versione 3.4: The function supports *note S_IFDOOR:
     11bd, *note S_IFPORT: 11be. and *note S_IFWHT: 11bf.

All the variables below are simply symbolic indexes into the 10-tuple
returned by *note os.stat(): 26d, *note os.fstat(): f8e. or *note
os.lstat(): 6c9.

 -- Dati: stat.ST_MODE

     Inode protection mode.

 -- Dati: stat.ST_INO

     Inode number.

 -- Dati: stat.ST_DEV

     Device inode resides on.

 -- Dati: stat.ST_NLINK

     Number of links to the inode.

 -- Dati: stat.ST_UID

     User id of the owner.

 -- Dati: stat.ST_GID

     Group id of the owner.

 -- Dati: stat.ST_SIZE

     Size in bytes of a plain file; amount of data waiting on some
     special files.

 -- Dati: stat.ST_ATIME

     Time of last access.

 -- Dati: stat.ST_MTIME

     Time of last modification.

 -- Dati: stat.ST_CTIME

     The «ctime» as reported by the operating system.  On some systems
     (like Unix) is the time of the last metadata change, and, on others
     (like Windows), is the creation time (see platform documentation
     for details).

The interpretation of «file size» changes according to the file type.
For plain files this is the size of the file in bytes.  For FIFOs and
sockets under most flavors of Unix (including Linux in particular), the
«size» is the number of bytes waiting to be read at the time of the call
to *note os.stat(): 26d, *note os.fstat(): f8e, or *note os.lstat():
6c9.; this can sometimes be useful, especially for polling one of these
special files after a non-blocking open.  The meaning of the size field
for other character and block devices varies more, depending on the
implementation of the underlying system call.

The variables below define the flags used in the *note ST_MODE: 11bc.
field.

Use of the functions above is more portable than use of the first set of
flags:

 -- Dati: stat.S_IFSOCK

     Socket.

 -- Dati: stat.S_IFLNK

     Symbolic link.

 -- Dati: stat.S_IFREG

     Regular file.

 -- Dati: stat.S_IFBLK

     Block device.

 -- Dati: stat.S_IFDIR

     Directory.

 -- Dati: stat.S_IFCHR

     Character device.

 -- Dati: stat.S_IFIFO

     FIFO.

 -- Dati: stat.S_IFDOOR

     Door.

     Added in version 3.4.

 -- Dati: stat.S_IFPORT

     Event port.

     Added in version 3.4.

 -- Dati: stat.S_IFWHT

     Whiteout.

     Added in version 3.4.

     Nota: *note S_IFDOOR: 11bd, *note S_IFPORT: 11be. or *note S_IFWHT:
     11bf. are defined as 0 when the platform does not have support for
     the file types.

The following flags can also be used in the 'mode' argument of *note
os.chmod(): 52a.:

 -- Dati: stat.S_ISUID

     Set UID bit.

 -- Dati: stat.S_ISGID

     Set-group-ID bit.  This bit has several special uses.  For a
     directory it indicates that BSD semantics is to be used for that
     directory: files created there inherit their group ID from the
     directory, not from the effective group ID of the creating process,
     and directories created there will also get the *note S_ISGID:
     2c5c. bit set.  For a file that does not have the group execution
     bit (*note S_IXGRP: 2c5d.) set, the set-group-ID bit indicates
     mandatory file/record locking (see also *note S_ENFMT: 2c5e.).

 -- Dati: stat.S_ISVTX

     Sticky bit.  When this bit is set on a directory it means that a
     file in that directory can be renamed or deleted only by the owner
     of the file, by the owner of the directory, or by a privileged
     process.

 -- Dati: stat.S_IRWXU

     Mask for file owner permissions.

 -- Dati: stat.S_IRUSR

     Owner has read permission.

 -- Dati: stat.S_IWUSR

     Owner has write permission.

 -- Dati: stat.S_IXUSR

     Owner has execute permission.

 -- Dati: stat.S_IRWXG

     Mask for group permissions.

 -- Dati: stat.S_IRGRP

     Group has read permission.

 -- Dati: stat.S_IWGRP

     Group has write permission.

 -- Dati: stat.S_IXGRP

     Group has execute permission.

 -- Dati: stat.S_IRWXO

     Mask for permissions for others (not in group).

 -- Dati: stat.S_IROTH

     Others have read permission.

 -- Dati: stat.S_IWOTH

     Others have write permission.

 -- Dati: stat.S_IXOTH

     Others have execute permission.

 -- Dati: stat.S_ENFMT

     System V file locking enforcement.  This flag is shared with *note
     S_ISGID: 2c5c.: file/record locking is enforced on files that do
     not have the group execution bit (*note S_IXGRP: 2c5d.) set.

 -- Dati: stat.S_IREAD

     Unix V7 synonym for *note S_IRUSR: 2c61.

 -- Dati: stat.S_IWRITE

     Unix V7 synonym for *note S_IWUSR: 2c62.

 -- Dati: stat.S_IEXEC

     Unix V7 synonym for *note S_IXUSR: 2c63.

The following flags can be used in the 'flags' argument of *note
os.chflags(): 12f5.:

 -- Dati: stat.UF_SETTABLE

     All user settable flags.

     Added in version 3.13.

 -- Dati: stat.UF_NODUMP

     Do not dump the file.

 -- Dati: stat.UF_IMMUTABLE

     The file may not be changed.

 -- Dati: stat.UF_APPEND

     The file may only be appended to.

 -- Dati: stat.UF_OPAQUE

     The directory is opaque when viewed through a union stack.

 -- Dati: stat.UF_NOUNLINK

     The file may not be renamed or deleted.

 -- Dati: stat.UF_COMPRESSED

     The file is stored compressed (macOS 10.6+).

 -- Dati: stat.UF_TRACKED

     Used for handling document IDs (macOS)

     Added in version 3.13.

 -- Dati: stat.UF_DATAVAULT

     The file needs an entitlement for reading or writing (macOS 10.13+)

     Added in version 3.13.

 -- Dati: stat.UF_HIDDEN

     The file should not be displayed in a GUI (macOS 10.5+).

 -- Dati: stat.SF_SETTABLE

     All super-user changeable flags

     Added in version 3.13.

 -- Dati: stat.SF_SUPPORTED

     All super-user supported flags

     *note Availability: 2128.: macOS

     Added in version 3.13.

 -- Dati: stat.SF_SYNTHETIC

     All super-user read-only synthetic flags

     *note Availability: 2128.: macOS

     Added in version 3.13.

 -- Dati: stat.SF_ARCHIVED

     The file may be archived.

 -- Dati: stat.SF_IMMUTABLE

     The file may not be changed.

 -- Dati: stat.SF_APPEND

     The file may only be appended to.

 -- Dati: stat.SF_RESTRICTED

     The file needs an entitlement to write to (macOS 10.13+)

     Added in version 3.13.

 -- Dati: stat.SF_NOUNLINK

     The file may not be renamed or deleted.

 -- Dati: stat.SF_SNAPSHOT

     The file is a snapshot file.

 -- Dati: stat.SF_FIRMLINK

     The file is a firmlink (macOS 10.15+)

     Added in version 3.13.

 -- Dati: stat.SF_DATALESS

     The file is a dataless object (macOS 10.15+)

     Added in version 3.13.

See the *BSD or macOS systems man page ‘chflags(2)(2)’ for more
information.

On Windows, the following file attribute constants are available for use
when testing bits in the ‘st_file_attributes’ member returned by *note
os.stat(): 26d.  See the Windows API documentation(3) for more detail on
the meaning of these constants.

 -- Dati: stat.FILE_ATTRIBUTE_ARCHIVE
 -- Dati: stat.FILE_ATTRIBUTE_COMPRESSED
 -- Dati: stat.FILE_ATTRIBUTE_DEVICE
 -- Dati: stat.FILE_ATTRIBUTE_DIRECTORY
 -- Dati: stat.FILE_ATTRIBUTE_ENCRYPTED
 -- Dati: stat.FILE_ATTRIBUTE_HIDDEN
 -- Dati: stat.FILE_ATTRIBUTE_INTEGRITY_STREAM
 -- Dati: stat.FILE_ATTRIBUTE_NORMAL
 -- Dati: stat.FILE_ATTRIBUTE_NOT_CONTENT_INDEXED
 -- Dati: stat.FILE_ATTRIBUTE_NO_SCRUB_DATA
 -- Dati: stat.FILE_ATTRIBUTE_OFFLINE
 -- Dati: stat.FILE_ATTRIBUTE_READONLY
 -- Dati: stat.FILE_ATTRIBUTE_REPARSE_POINT
 -- Dati: stat.FILE_ATTRIBUTE_SPARSE_FILE
 -- Dati: stat.FILE_ATTRIBUTE_SYSTEM
 -- Dati: stat.FILE_ATTRIBUTE_TEMPORARY
 -- Dati: stat.FILE_ATTRIBUTE_VIRTUAL

     Added in version 3.5.

On Windows, the following constants are available for comparing against
the ‘st_reparse_tag’ member returned by *note os.lstat(): 6c9.  These
are well-known constants, but are not an exhaustive list.

 -- Dati: stat.IO_REPARSE_TAG_SYMLINK
 -- Dati: stat.IO_REPARSE_TAG_MOUNT_POINT
 -- Dati: stat.IO_REPARSE_TAG_APPEXECLINK

     Added in version 3.8.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/stat.py

   (2) https://manpages.debian.org/chflags(2)

   (3) 
https://msdn.microsoft.com/en-us/library/windows/desktop/gg258117.aspx


File: python.info,  Node: filecmp — File and Directory Comparisons,  Next: tempfile — Generate temporary files and directories,  Prev: stat — Interpreting stat results,  Up: File and Directory Access

5.11.4 ‘filecmp’ — File and Directory Comparisons
-------------------------------------------------

'Source code:' Lib/filecmp.py(1)

__________________________________________________________________

The *note filecmp: 5e. module defines functions to compare files and
directories, with various optional time/correctness trade-offs.  For
comparing files, see also the *note difflib: 3b. module.

The *note filecmp: 5e. module defines the following functions:

 -- Funzione: filecmp.cmp (f1, f2, shallow=True)

     Compare the files named 'f1' and 'f2', returning ‘True’ if they
     seem equal, ‘False’ otherwise.

     If 'shallow' is true and the *note os.stat(): 26d. signatures (file
     type, size, and modification time) of both files are identical, the
     files are taken to be equal.

     Otherwise, the files are treated as different if their sizes or
     contents differ.

     Note that no external programs are called from this function,
     giving it portability and efficiency.

     This function uses a cache for past comparisons and the results,
     with cache entries invalidated if the *note os.stat(): 26d.
     information for the file changes.  The entire cache may be cleared
     using *note clear_cache(): 1140.

 -- Funzione: filecmp.cmpfiles (dir1, dir2, common, shallow=True)

     Compare the files in the two directories 'dir1' and 'dir2' whose
     names are given by 'common'.

     Returns three lists of file names: 'match', 'mismatch', 'errors'.
     'match' contains the list of files that match, 'mismatch' contains
     the names of those that don’t, and 'errors' lists the names of
     files which could not be compared.  Files are listed in 'errors' if
     they don’t exist in one of the directories, the user lacks
     permission to read them or if the comparison could not be done for
     some other reason.

     The 'shallow' parameter has the same meaning and default value as
     for *note filecmp.cmp(): 19c5.

     For example, ‘cmpfiles('a', 'b', ['c', 'd/e'])’ will compare ‘a/c’
     with ‘b/c’ and ‘a/d/e’ with ‘b/d/e’.  ‘'c'’ and ‘'d/e'’ will each
     be in one of the three returned lists.

 -- Funzione: filecmp.clear_cache ()

     Clear the filecmp cache.  This may be useful if a file is compared
     so quickly after it is modified that it is within the mtime
     resolution of the underlying filesystem.

     Added in version 3.4.

* Menu:

* The dircmp class::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/filecmp.py


File: python.info,  Node: The dircmp class,  Up: filecmp — File and Directory Comparisons

5.11.4.1 The ‘dircmp’ class
...........................

 -- Classe: filecmp.dircmp (a, b, ignore=None, hide=None, *,
          shallow=True)

     Construct a new directory comparison object, to compare the
     directories 'a' and 'b'.  'ignore' is a list of names to ignore,
     and defaults to *note filecmp.DEFAULT_IGNORES: 1141.  'hide' is a
     list of names to hide, and defaults to ‘[os.curdir, os.pardir]’.

     The *note dircmp: 1142. class compares files by doing 'shallow'
     comparisons as described for *note filecmp.cmp(): 19c5. by default
     using the 'shallow' parameter.

     Cambiato nella versione 3.13: Added the 'shallow' parameter.

     The *note dircmp: 1142. class provides the following methods:

      -- Metodo: report ()

          Print (to *note sys.stdout: ccf.) a comparison between 'a' and
          'b'.

      -- Metodo: report_partial_closure ()

          Print a comparison between 'a' and 'b' and common immediate
          subdirectories.

      -- Metodo: report_full_closure ()

          Print a comparison between 'a' and 'b' and common
          subdirectories (recursively).

     The *note dircmp: 1142. class offers a number of interesting
     attributes that may be used to get various bits of information
     about the directory trees being compared.

     Note that via *note __getattr__(): 6fb. hooks, all attributes are
     computed lazily, so there is no speed penalty if only those
     attributes which are lightweight to compute are used.

      -- Attributo: left

          The directory 'a'.

      -- Attributo: right

          The directory 'b'.

      -- Attributo: left_list

          Files and subdirectories in 'a', filtered by 'hide' and
          'ignore'.

      -- Attributo: right_list

          Files and subdirectories in 'b', filtered by 'hide' and
          'ignore'.

      -- Attributo: common

          Files and subdirectories in both 'a' and 'b'.

      -- Attributo: left_only

          Files and subdirectories only in 'a'.

      -- Attributo: right_only

          Files and subdirectories only in 'b'.

      -- Attributo: common_dirs

          Subdirectories in both 'a' and 'b'.

      -- Attributo: common_files

          Files in both 'a' and 'b'.

      -- Attributo: common_funny

          Names in both 'a' and 'b', such that the type differs between
          the directories, or names for which *note os.stat(): 26d.
          reports an error.

      -- Attributo: same_files

          Files which are identical in both 'a' and 'b', using the
          class’s file comparison operator.

      -- Attributo: diff_files

          Files which are in both 'a' and 'b', whose contents differ
          according to the class’s file comparison operator.

      -- Attributo: funny_files

          Files which are in both 'a' and 'b', but could not be
          compared.

      -- Attributo: subdirs

          A dictionary mapping names in *note common_dirs: 2ca6. to
          *note dircmp: 1142. instances (or MyDirCmp instances if this
          instance is of type MyDirCmp, a subclass of *note dircmp:
          1142.).

          Cambiato nella versione 3.10: Previously entries were always
          *note dircmp: 1142. instances.  Now entries are the same type
          as 'self', if 'self' is a subclass of *note dircmp: 1142.

 -- Dati: filecmp.DEFAULT_IGNORES

     Added in version 3.4.

     List of directories ignored by *note dircmp: 1142. by default.

Here is a simplified example of using the ‘subdirs’ attribute to search
recursively through two directories to show common different files:

     >>> from filecmp import dircmp
     >>> def print_diff_files(dcmp):
     ...     for name in dcmp.diff_files:
     ...         print("diff_file %s found in %s and %s" % (name, dcmp.left,
     ...               dcmp.right))
     ...     for sub_dcmp in dcmp.subdirs.values():
     ...         print_diff_files(sub_dcmp)
     ...
     >>> dcmp = dircmp('dir1', 'dir2')
     >>> print_diff_files(dcmp)


File: python.info,  Node: tempfile — Generate temporary files and directories,  Next: glob — Unix style pathname pattern expansion,  Prev: filecmp — File and Directory Comparisons,  Up: File and Directory Access

5.11.5 ‘tempfile’ — Generate temporary files and directories
------------------------------------------------------------

'Source code:' Lib/tempfile.py(1)

__________________________________________________________________

This module creates temporary files and directories.  It works on all
supported platforms.  *note TemporaryFile: 2caf, *note
NamedTemporaryFile: 6ee, *note TemporaryDirectory: 143c, and *note
SpooledTemporaryFile: 8a3. are high-level interfaces which provide
automatic cleanup and can be used as *note context managers: 1e1.  *note
mkstemp(): 2cb0. and *note mkdtemp(): 52e. are lower-level functions
which require manual cleanup.

All the user-callable functions and constructors take additional
arguments which allow direct control over the location and name of
temporary files and directories.  Files names used by this module
include a string of random characters which allows those files to be
securely created in shared temporary directories.  To maintain backward
compatibility, the argument order is somewhat odd; it is recommended to
use keyword arguments for clarity.

The module defines the following user-callable items:

 -- Funzione: tempfile.TemporaryFile (mode='w+b', buffering=-1,
          encoding=None, newline=None, suffix=None, prefix=None,
          dir=None, *, errors=None)

     Return a *note file-like object: 1794. that can be used as a
     temporary storage area.  The file is created securely, using the
     same rules as *note mkstemp(): 2cb0.  It will be destroyed as soon
     as it is closed (including an implicit close when the object is
     garbage collected).  Under Unix, the directory entry for the file
     is either not created at all or is removed immediately after the
     file is created.  Other platforms do not support this; your code
     should not rely on a temporary file created using this function
     having or not having a visible name in the file system.

     The resulting object can be used as a *note context manager: 1e1.
     (see *note Examples: 2cb1.).  On completion of the context or
     destruction of the file object the temporary file will be removed
     from the filesystem.

     The 'mode' parameter defaults to ‘'w+b'’ so that the file created
     can be read and written without being closed.  Binary mode is used
     so that it behaves consistently on all platforms without regard for
     the data that is stored.  'buffering', 'encoding', 'errors' and
     'newline' are interpreted as for *note open(): 316.

     The 'dir', 'prefix' and 'suffix' parameters have the same meaning
     and defaults as with *note mkstemp(): 2cb0.

     The returned object is a true file object on POSIX platforms.  On
     other platforms, it is a file-like object whose ‘file’ attribute is
     the underlying true file object.

     The *note os.O_TMPFILE: 1175. flag is used if it is available and
     works (Linux-specific, requires Linux kernel 3.11 or later).

     On platforms that are neither Posix nor Cygwin, TemporaryFile is an
     alias for NamedTemporaryFile.

     Raises an *note auditing event: 1c56. ‘tempfile.mkstemp’ with
     argument ‘fullpath’.

     Cambiato nella versione 3.5: The *note os.O_TMPFILE: 1175. flag is
     now used if available.

     Cambiato nella versione 3.8: Added 'errors' parameter.

 -- Funzione: tempfile.NamedTemporaryFile (mode='w+b', buffering=-1,
          encoding=None, newline=None, suffix=None, prefix=None,
          dir=None, delete=True, *, errors=None, delete_on_close=True)

     This function operates exactly as *note TemporaryFile(): 2caf.
     does, except the following differences:

        * This function returns a file that is guaranteed to have a
          visible name in the file system.

        * To manage the named file, it extends the parameters of *note
          TemporaryFile(): 2caf. with 'delete' and 'delete_on_close'
          parameters that determine whether and how the named file
          should be automatically deleted.

     The returned object is always a *note file-like object: 1794. whose
     ‘file’ attribute is the underlying true file object.  This
     file-like object can be used in a *note with: 186. statement, just
     like a normal file.  The name of the temporary file can be
     retrieved from the ‘name’ attribute of the returned file-like
     object.  On Unix, unlike with the *note TemporaryFile(): 2caf, the
     directory entry does not get unlinked immediately after the file
     creation.

     If 'delete' is true (the default) and 'delete_on_close' is true
     (the default), the file is deleted as soon as it is closed.  If
     'delete' is true and 'delete_on_close' is false, the file is
     deleted on context manager exit only, or else when the *note
     file-like object: 1794. is finalized.  Deletion is not always
     guaranteed in this case (see *note object.__del__(): 11ff.).  If
     'delete' is false, the value of 'delete_on_close' is ignored.

     Therefore to use the name of the temporary file to reopen the file
     after closing it, either make sure not to delete the file upon
     closure (set the 'delete' parameter to be false) or, in case the
     temporary file is created in a *note with: 186. statement, set the
     'delete_on_close' parameter to be false.  The latter approach is
     recommended as it provides assistance in automatic cleaning of the
     temporary file upon the context manager exit.

     Opening the temporary file again by its name while it is still open
     works as follows:

        * On POSIX the file can always be opened again.

        * On Windows, make sure that at least one of the following
          conditions are fulfilled:

             * 'delete' is false

             * additional open shares delete access (e.g.  by calling
               *note os.open(): f94. with the flag ‘O_TEMPORARY’)

             * 'delete' is true but 'delete_on_close' is false.  Note,
               that in this case the additional opens that do not share
               delete access (e.g.  created via builtin *note open():
               316.) must be closed before exiting the context manager,
               else the *note os.unlink(): 12fd. call on context manager
               exit will fail with a *note PermissionError: f40.

     On Windows, if 'delete_on_close' is false, and the file is created
     in a directory for which the user lacks delete access, then the
     *note os.unlink(): 12fd. call on exit of the context manager will
     fail with a *note PermissionError: f40.  This cannot happen when
     'delete_on_close' is true because delete access is requested by the
     open, which fails immediately if the requested access is not
     granted.

     On POSIX (only), a process that is terminated abruptly with SIGKILL
     cannot automatically delete any NamedTemporaryFiles it created.

     Raises an *note auditing event: 1c56. ‘tempfile.mkstemp’ with
     argument ‘fullpath’.

     Cambiato nella versione 3.8: Added 'errors' parameter.

     Cambiato nella versione 3.12: Added 'delete_on_close' parameter.

 -- Classe: tempfile.SpooledTemporaryFile (max_size=0, mode='w+b',
          buffering=-1, encoding=None, newline=None, suffix=None,
          prefix=None, dir=None, *, errors=None)

     This class operates exactly as *note TemporaryFile(): 2caf. does,
     except that data is spooled in memory until the file size exceeds
     'max_size', or until the file’s *note fileno(): 1795. method is
     called, at which point the contents are written to disk and
     operation proceeds as with *note TemporaryFile(): 2caf.

      -- Metodo: rollover ()

          The resulting file has one additional method, ‘rollover()’,
          which causes the file to roll over to an on-disk file
          regardless of its size.

     The returned object is a file-like object whose ‘_file’ attribute
     is either an *note io.BytesIO: 10a6. or *note io.TextIOWrapper:
     9c0. object (depending on whether binary or text 'mode' was
     specified) or a true file object, depending on whether *note
     rollover(): 2cb2. has been called.  This file-like object can be
     used in a *note with: 186. statement, just like a normal file.

     Cambiato nella versione 3.3: the truncate method now accepts a
     'size' argument.

     Cambiato nella versione 3.8: Added 'errors' parameter.

     Cambiato nella versione 3.11: Fully implements the *note
     io.BufferedIOBase: 8a4. and *note io.TextIOBase: 8a5. abstract base
     classes (depending on whether binary or text 'mode' was specified).

 -- Classe: tempfile.TemporaryDirectory (suffix=None, prefix=None,
          dir=None, ignore_cleanup_errors=False, *, delete=True)

     This class securely creates a temporary directory using the same
     rules as *note mkdtemp(): 52e.  The resulting object can be used as
     a *note context manager: 1e1. (see *note Examples: 2cb1.).  On
     completion of the context or destruction of the temporary directory
     object, the newly created temporary directory and all its contents
     are removed from the filesystem.

      -- Attributo: name

          The directory name can be retrieved from the ‘name’ attribute
          of the returned object.  When the returned object is used as a
          *note context manager: 1e1, the ‘name’ will be assigned to the
          target of the ‘as’ clause in the *note with: 186. statement,
          if there is one.

      -- Metodo: cleanup ()

          The directory can be explicitly cleaned up by calling the
          ‘cleanup()’ method.  If 'ignore_cleanup_errors' is true, any
          unhandled exceptions during explicit or implicit cleanup (such
          as a *note PermissionError: f40. removing open files on
          Windows) will be ignored, and the remaining removable items
          deleted on a «best-effort» basis.  Otherwise, errors will be
          raised in whatever context cleanup occurs (the ‘cleanup()’
          call, exiting the context manager, when the object is
          garbage-collected or during interpreter shutdown).

     The 'delete' parameter can be used to disable cleanup of the
     directory tree upon exiting the context.  While it may seem unusual
     for a context manager to disable the action taken when exiting the
     context, it can be useful during debugging or when you need your
     cleanup behavior to be conditional based on other logic.

     Raises an *note auditing event: 1c56. ‘tempfile.mkdtemp’ with
     argument ‘fullpath’.

     Added in version 3.2.

     Cambiato nella versione 3.10: Added 'ignore_cleanup_errors'
     parameter.

     Cambiato nella versione 3.12: Added the 'delete' parameter.

 -- Funzione: tempfile.mkstemp (suffix=None, prefix=None, dir=None,
          text=False)

     Creates a temporary file in the most secure manner possible.  There
     are no race conditions in the file’s creation, assuming that the
     platform properly implements the *note os.O_EXCL: 2cb5. flag for
     *note os.open(): f94.  The file is readable and writable only by
     the creating user ID. If the platform uses permission bits to
     indicate whether a file is executable, the file is executable by no
     one.

     The file descriptor is *note not inherited by child processes:
     10fe.

     Unlike *note TemporaryFile(): 2caf, the user of *note mkstemp():
     2cb0. is responsible for deleting the temporary file when done with
     it.

     If 'suffix' is not ‘None’, the file name will end with that suffix,
     otherwise there will be no suffix.  *note mkstemp(): 2cb0. does not
     put a dot between the file name and the suffix; if you need one,
     put it at the beginning of 'suffix'.

     If 'prefix' is not ‘None’, the file name will begin with that
     prefix; otherwise, a default prefix is used.  The default is the
     return value of *note gettempprefix(): 2cb6. or *note
     gettempprefixb(): 2cb7, as appropriate.

     If 'dir' is not ‘None’, the file will be created in that directory;
     otherwise, a default directory is used.  The default directory is
     chosen from a platform-dependent list, but the user of the
     application can control the directory location by setting the
     'TMPDIR', 'TEMP' or 'TMP' environment variables.  There is thus no
     guarantee that the generated filename will have any nice
     properties, such as not requiring quoting when passed to external
     commands via ‘os.popen()’.

     If any of 'suffix', 'prefix', and 'dir' are not ‘None’, they must
     be the same type.  If they are bytes, the returned name will be
     bytes instead of str.  If you want to force a bytes return value
     with otherwise default behavior, pass ‘suffix=b''’.

     If 'text' is specified and true, the file is opened in text mode.
     Otherwise, (the default) the file is opened in binary mode.

     *note mkstemp(): 2cb0. returns a tuple containing an OS-level
     handle to an open file (as would be returned by *note os.open():
     f94.) and the absolute pathname of that file, in that order.

     Raises an *note auditing event: 1c56. ‘tempfile.mkstemp’ with
     argument ‘fullpath’.

     Cambiato nella versione 3.5: 'suffix', 'prefix', and 'dir' may now
     be supplied in bytes in order to obtain a bytes return value.
     Prior to this, only str was allowed.  'suffix' and 'prefix' now
     accept and default to ‘None’ to cause an appropriate default value
     to be used.

     Cambiato nella versione 3.6: The 'dir' parameter now accepts a
     *note path-like object: 5a1.

 -- Funzione: tempfile.mkdtemp (suffix=None, prefix=None, dir=None)

     Creates a temporary directory in the most secure manner possible.
     There are no race conditions in the directory’s creation.  The
     directory is readable, writable, and searchable only by the
     creating user ID.

     The user of *note mkdtemp(): 52e. is responsible for deleting the
     temporary directory and its contents when done with it.

     The 'prefix', 'suffix', and 'dir' arguments are the same as for
     *note mkstemp(): 2cb0.

     *note mkdtemp(): 52e. returns the absolute pathname of the new
     directory.

     Raises an *note auditing event: 1c56. ‘tempfile.mkdtemp’ with
     argument ‘fullpath’.

     Cambiato nella versione 3.5: 'suffix', 'prefix', and 'dir' may now
     be supplied in bytes in order to obtain a bytes return value.
     Prior to this, only str was allowed.  'suffix' and 'prefix' now
     accept and default to ‘None’ to cause an appropriate default value
     to be used.

     Cambiato nella versione 3.6: The 'dir' parameter now accepts a
     *note path-like object: 5a1.

     Cambiato nella versione 3.12: *note mkdtemp(): 52e. now always
     returns an absolute path, even if 'dir' is relative.

 -- Funzione: tempfile.gettempdir ()

     Return the name of the directory used for temporary files.  This
     defines the default value for the 'dir' argument to all functions
     in this module.

     Python searches a standard list of directories to find one which
     the calling user can create files in.  The list is:

       1. The directory named by the ‘TMPDIR’ environment variable.

       2. The directory named by the ‘TEMP’ environment variable.

       3. The directory named by the ‘TMP’ environment variable.

       4. A platform-specific location:

             * On Windows, the directories ‘C:\TEMP’, ‘C:\TMP’, ‘\TEMP’,
               and ‘\TMP’, in that order.

             * On all other platforms, the directories ‘/tmp’,
               ‘/var/tmp’, and ‘/usr/tmp’, in that order.

       5. As a last resort, the current working directory.

     The result of this search is cached, see the description of *note
     tempdir: 1c7a. below.

     Cambiato nella versione 3.10: Always returns a str.  Previously it
     would return any *note tempdir: 1c7a. value regardless of type so
     long as it was not ‘None’.

 -- Funzione: tempfile.gettempdirb ()

     Same as *note gettempdir(): 1c7b. but the return value is in bytes.

     Added in version 3.5.

 -- Funzione: tempfile.gettempprefix ()

     Return the filename prefix used to create temporary files.  This
     does not contain the directory component.

 -- Funzione: tempfile.gettempprefixb ()

     Same as *note gettempprefix(): 2cb6. but the return value is in
     bytes.

     Added in version 3.5.

The module uses a global variable to store the name of the directory
used for temporary files returned by *note gettempdir(): 1c7b.  It can
be set directly to override the selection process, but this is
discouraged.  All functions in this module take a 'dir' argument which
can be used to specify the directory.  This is the recommended approach
that does not surprise other unsuspecting code by changing global API
behavior.

 -- Dati: tempfile.tempdir

     When set to a value other than ‘None’, this variable defines the
     default value for the 'dir' argument to the functions defined in
     this module, including its type, bytes or str.  It cannot be a
     *note path-like object: 5a1.

     If ‘tempdir’ is ‘None’ (the default) at any call to any of the
     above functions except *note gettempprefix(): 2cb6. it is
     initialized following the algorithm described in *note
     gettempdir(): 1c7b.

          Nota: Beware that if you set ‘tempdir’ to a bytes value, there
          is a nasty side effect: The global default return type of
          *note mkstemp(): 2cb0. and *note mkdtemp(): 52e. changes to
          bytes when no explicit ‘prefix’, ‘suffix’, or ‘dir’ arguments
          of type str are supplied.  Please do not write code expecting
          or depending on this.  This awkward behavior is maintained for
          compatibility with the historical implementation.

* Menu:

* Examples: Examples<5>.
* Deprecated functions and variables::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/tempfile.py


File: python.info,  Node: Examples<5>,  Next: Deprecated functions and variables,  Up: tempfile — Generate temporary files and directories

5.11.5.1 Examples
.................

Here are some examples of typical usage of the *note tempfile: e6.
module:

     >>> import tempfile

     # create a temporary file and write some data to it
     >>> fp = tempfile.TemporaryFile()
     >>> fp.write(b'Hello world!')
     # read data from file
     >>> fp.seek(0)
     >>> fp.read()
     b'Hello world!'
     # close the file, it will be removed
     >>> fp.close()

     # create a temporary file using a context manager
     >>> with tempfile.TemporaryFile() as fp:
     ...     fp.write(b'Hello world!')
     ...     fp.seek(0)
     ...     fp.read()
     b'Hello world!'
     >>>
     # file is now closed and removed

     # create a temporary file using a context manager
     # close the file, use the name to open the file again
     >>> with tempfile.NamedTemporaryFile(delete_on_close=False) as fp:
     ...     fp.write(b'Hello world!')
     ...     fp.close()
     ... # the file is closed, but not removed
     ... # open the file again by using its name
     ...     with open(fp.name, mode='rb') as f:
     ...         f.read()
     b'Hello world!'
     >>>
     # file is now removed

     # create a temporary directory using the context manager
     >>> with tempfile.TemporaryDirectory() as tmpdirname:
     ...     print('created temporary directory', tmpdirname)
     >>>
     # directory and contents have been removed


File: python.info,  Node: Deprecated functions and variables,  Prev: Examples<5>,  Up: tempfile — Generate temporary files and directories

5.11.5.2 Deprecated functions and variables
...........................................

A historical way to create temporary files was to first generate a file
name with the *note mktemp(): 1c18. function and then create a file
using this name.  Unfortunately this is not secure, because a different
process may create a file with this name in the time between the call to
*note mktemp(): 1c18. and the subsequent attempt to create the file by
the first process.  The solution is to combine the two steps and create
the file immediately.  This approach is used by *note mkstemp(): 2cb0.
and the other functions described above.

 -- Funzione: tempfile.mktemp (suffix='', prefix='tmp', dir=None)

     Deprecato dalla versione 2.3: Use *note mkstemp(): 2cb0. instead.

     Return an absolute pathname of a file that did not exist at the
     time the call is made.  The 'prefix', 'suffix', and 'dir' arguments
     are similar to those of *note mkstemp(): 2cb0, except that bytes
     file names, ‘suffix=None’ and ‘prefix=None’ are not supported.

          Avvertimento: Use of this function may introduce a security
          hole in your program.  By the time you get around to doing
          anything with the file name it returns, someone else may have
          beaten you to the punch.  *note mktemp(): 1c18. usage can be
          replaced easily with *note NamedTemporaryFile(): 6ee, passing
          it the ‘delete=False’ parameter:

               >>> f = NamedTemporaryFile(delete=False)
               >>> f.name
               '/tmp/tmptjujjt'
               >>> f.write(b"Hello World!\n")
               13
               >>> f.close()
               >>> os.unlink(f.name)
               >>> os.path.exists(f.name)
               False


File: python.info,  Node: glob — Unix style pathname pattern expansion,  Next: fnmatch — Unix filename pattern matching,  Prev: tempfile — Generate temporary files and directories,  Up: File and Directory Access

5.11.6 ‘glob’ — Unix style pathname pattern expansion
-----------------------------------------------------

'Source code:' Lib/glob.py(1)

__________________________________________________________________

The ‘glob’ module finds pathnames using pattern matching rules similar
to the Unix shell.  No tilde expansion is done, but ‘*’, ‘?’, and
character ranges expressed with ‘[]’ will be correctly matched.  This is
done by using the *note os.scandir(): c56. and *note fnmatch.fnmatch():
1c3c. functions in concert, and not by actually invoking a subshell.

     Nota: The pathnames are returned in no particular order.  If you
     need a specific order, sort the results.

Files beginning with a dot (‘.’) can only be matched by patterns that
also start with a dot, unlike *note fnmatch.fnmatch(): 1c3c. or *note
pathlib.Path.glob(): 538.  For tilde and shell variable expansion, use
*note os.path.expanduser(): c0b. and *note os.path.expandvars(): 15e0.

For a literal match, wrap the meta-characters in brackets.  For example,
‘'[?]'’ matches the character ‘'?'’.

The ‘glob’ module defines the following functions:

 -- Funzione: glob.glob (pathname, *, root_dir=None, dir_fd=None,
          recursive=False, include_hidden=False)

     Return a possibly empty list of path names that match 'pathname',
     which must be a string containing a path specification.  'pathname'
     can be either absolute (like ‘/usr/src/Python-1.5/Makefile’) or
     relative (like ‘../../Tools/*/*.gif’), and can contain shell-style
     wildcards.  Broken symlinks are included in the results (as in the
     shell).  Whether or not the results are sorted depends on the file
     system.  If a file that satisfies conditions is removed or added
     during the call of this function, whether a path name for that file
     will be included is unspecified.

     If 'root_dir' is not ‘None’, it should be a *note path-like object:
     5a1. specifying the root directory for searching.  It has the same
     effect on ‘glob()’ as changing the current directory before calling
     it.  If 'pathname' is relative, the result will contain paths
     relative to 'root_dir'.

     This function can support *note paths relative to directory
     descriptors: 12f2. with the 'dir_fd' parameter.

     If 'recursive' is true, the pattern «‘**’» will match any files and
     zero or more directories, subdirectories and symbolic links to
     directories.  If the pattern is followed by an *note os.sep: 87b.
     or *note os.altsep: 87c. then files will not match.

     If 'include_hidden' is true, «‘**’» pattern will match hidden
     directories.

     Raises an *note auditing event: 1c56. ‘glob.glob’ with arguments
     ‘pathname’, ‘recursive’.

     Raises an *note auditing event: 1c56. ‘glob.glob/2’ with arguments
     ‘pathname’, ‘recursive’, ‘root_dir’, ‘dir_fd’.

          Nota: Using the «‘**’» pattern in large directory trees may
          consume an inordinate amount of time.

          Nota: This function may return duplicate path names if
          'pathname' contains multiple «‘**’» patterns and 'recursive'
          is true.

     Cambiato nella versione 3.5: Support for recursive globs using
     «‘**’».

     Cambiato nella versione 3.10: Added the 'root_dir' and 'dir_fd'
     parameters.

     Cambiato nella versione 3.11: Added the 'include_hidden' parameter.

 -- Funzione: glob.iglob (pathname, *, root_dir=None, dir_fd=None,
          recursive=False, include_hidden=False)

     Return an *note iterator: 4c9. which yields the same values as
     *note glob(): 68. without actually storing them all simultaneously.

     Raises an *note auditing event: 1c56. ‘glob.glob’ with arguments
     ‘pathname’, ‘recursive’.

     Raises an *note auditing event: 1c56. ‘glob.glob/2’ with arguments
     ‘pathname’, ‘recursive’, ‘root_dir’, ‘dir_fd’.

          Nota: This function may return duplicate path names if
          'pathname' contains multiple «‘**’» patterns and 'recursive'
          is true.

     Cambiato nella versione 3.5: Support for recursive globs using
     «‘**’».

     Cambiato nella versione 3.10: Added the 'root_dir' and 'dir_fd'
     parameters.

     Cambiato nella versione 3.11: Added the 'include_hidden' parameter.

 -- Funzione: glob.escape (pathname)

     Escape all special characters (‘'?'’, ‘'*'’ and ‘'['’).  This is
     useful if you want to match an arbitrary literal string that may
     have special characters in it.  Special characters in drive/UNC
     sharepoints are not escaped, e.g.  on Windows ‘escape('//?/c:/Quo
     vadis?.txt')’ returns ‘'//?/c:/Quo vadis[?].txt'’.

     Added in version 3.4.

 -- Funzione: glob.translate (pathname, *, recursive=False,
          include_hidden=False, seps=None)

     Convert the given path specification to a regular expression for
     use with *note re.match(): 1435.  The path specification can
     contain shell-style wildcards.

     For example:

          >>> import glob, re
          >>>
          >>> regex = glob.translate('**/*.txt', recursive=True, include_hidden=True)
          >>> regex
          '(?s:(?:.+/)?[^/]*\\.txt)\\z'
          >>> reobj = re.compile(regex)
          >>> reobj.match('foo/bar/baz.txt')
          <re.Match object; span=(0, 15), match='foo/bar/baz.txt'>

     Path separators and segments are meaningful to this function,
     unlike *note fnmatch.translate(): 1837.  By default wildcards do
     not match path separators, and ‘*’ pattern segments match precisely
     one path segment.

     If 'recursive' is true, the pattern segment «‘**’» will match any
     number of path segments.

     If 'include_hidden' is true, wildcards can match path segments that
     start with a dot (‘.’).

     A sequence of path separators may be supplied to the 'seps'
     argument.  If not given, *note os.sep: 87b. and *note altsep: 87c.
     (if available) are used.

     Vedi anche
     ..........

     *note pathlib.PurePath.full_match(): 536. and *note
     pathlib.Path.glob(): 538. methods, which call this function to
     implement pattern matching and globbing.

     Added in version 3.13.

* Menu:

* Examples: Examples<6>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/glob.py


File: python.info,  Node: Examples<6>,  Up: glob — Unix style pathname pattern expansion

5.11.6.1 Examples
.................

Consider a directory containing the following files: ‘1.gif’, ‘2.txt’,
‘card.gif’ and a subdirectory ‘sub’ which contains only the file
‘3.txt’.  *note glob(): 68. will produce the following results.  Notice
how any leading components of the path are preserved.

     >>> import glob
     >>> glob.glob('./[0-9].*')
     ['./1.gif', './2.txt']
     >>> glob.glob('*.gif')
     ['1.gif', 'card.gif']
     >>> glob.glob('?.gif')
     ['1.gif']
     >>> glob.glob('**/*.txt', recursive=True)
     ['2.txt', 'sub/3.txt']
     >>> glob.glob('./**/', recursive=True)
     ['./', './sub/']

If the directory contains files starting with ‘.’ they won’t be matched
by default.  For example, consider a directory containing ‘card.gif’ and
‘.card.gif’:

     >>> import glob
     >>> glob.glob('*.gif')
     ['card.gif']
     >>> glob.glob('.c*')
     ['.card.gif']

Vedi anche
..........

The *note fnmatch: 60. module offers shell-style filename (not path)
expansion.

Vedi anche
..........

The *note pathlib: a8. module offers high-level path objects.


File: python.info,  Node: fnmatch — Unix filename pattern matching,  Next: linecache — Random access to text lines,  Prev: glob — Unix style pathname pattern expansion,  Up: File and Directory Access

5.11.7 ‘fnmatch’ — Unix filename pattern matching
-------------------------------------------------

'Source code:' Lib/fnmatch.py(1)

__________________________________________________________________

This module provides support for Unix shell-style wildcards, which are
'not' the same as regular expressions (which are documented in the *note
re: be. module).  The special characters used in shell-style wildcards
are:

Pattern          Meaning
                 
----------------------------------------------------------
                 
‘*’              matches everything
                 
                 
‘?’              matches any single character
                 
                 
‘[seq]’          matches any character in 'seq'
                 
                 
‘[!seq]’         matches any character not in 'seq'
                 

For a literal match, wrap the meta-characters in brackets.  For example,
‘'[?]'’ matches the character ‘'?'’.

Note that the filename separator (‘'/'’ on Unix) is 'not' special to
this module.  See module *note glob: 68. for pathname expansion (*note
glob: 68. uses *note filter(): 1c3e. to match pathname segments).
Similarly, filenames starting with a period are not special for this
module, and are matched by the ‘*’ and ‘?’ patterns.

Unless stated otherwise, «filename string» and «pattern string» either
refer to *note str: 169. or ‘ISO-8859-1’ encoded *note bytes: 192.
objects.  Note that the functions documented below do not allow to mix a
‘bytes’ pattern with a ‘str’ filename, and vice-versa.

Finally, note that *note functools.lru_cache(): be4. with a 'maxsize' of
32768 is used to cache the (typed) compiled regex patterns in the
following functions: *note fnmatch(): 60, *note fnmatchcase(): 1c3d,
*note filter(): 1c3e, *note filterfalse(): 211.

 -- Funzione: fnmatch.fnmatch (name, pat)

     Test whether the filename string 'name' matches the pattern string
     'pat', returning ‘True’ or ‘False’.  Both parameters are
     case-normalized using *note os.path.normcase(): 2c3c.  *note
     fnmatchcase(): 1c3d. can be used to perform a case-sensitive
     comparison, regardless of whether that’s standard for the operating
     system.

     This example will print all file names in the current directory
     with the extension ‘.txt’:

          import fnmatch
          import os

          for file in os.listdir('.'):
              if fnmatch.fnmatch(file, '*.txt'):
                  print(file)

 -- Funzione: fnmatch.fnmatchcase (name, pat)

     Test whether the filename string 'name' matches the pattern string
     'pat', returning ‘True’ or ‘False’; the comparison is
     case-sensitive and does not apply *note os.path.normcase(): 2c3c.

 -- Funzione: fnmatch.filter (names, pat)

     Construct a list from those elements of the *note iterable: 142f.
     of filename strings 'names' that match the pattern string 'pat'.
     It is the same as ‘[n for n in names if fnmatch(n, pat)]’, but
     implemented more efficiently.

 -- Funzione: fnmatch.filterfalse (names, pat)

     Construct a list from those elements of the *note iterable: 142f.
     of filename strings 'names' that do not match the pattern string
     'pat'.  It is the same as ‘[n for n in names if not fnmatch(n,
     pat)]’, but implemented more efficiently.

     Added in version 3.14.

 -- Funzione: fnmatch.translate (pat)

     Return the shell-style pattern 'pat' converted to a regular
     expression for using with *note re.match(): 1435.  The pattern is
     expected to be a *note str: 169.

     Example:

          >>> import fnmatch, re
          >>>
          >>> regex = fnmatch.translate('*.txt')
          >>> regex
          '(?s:.*\\.txt)\\z'
          >>> reobj = re.compile(regex)
          >>> reobj.match('foobar.txt')
          <re.Match object; span=(0, 10), match='foobar.txt'>

Vedi anche
..........

Module *note glob: 68.

     Unix shell-style path expansion.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/fnmatch.py


File: python.info,  Node: linecache — Random access to text lines,  Next: shutil — High-level file operations,  Prev: fnmatch — Unix filename pattern matching,  Up: File and Directory Access

5.11.8 ‘linecache’ — Random access to text lines
------------------------------------------------

'Source code:' Lib/linecache.py(1)

__________________________________________________________________

The *note linecache: 89. module allows one to get any line from a Python
source file, while attempting to optimize internally, using a cache, the
common case where many lines are read from a single file.  This is used
by the *note traceback: 104. module to retrieve source lines for
inclusion in the formatted traceback.

The *note tokenize.open(): 2cc5. function is used to open files.  This
function uses *note tokenize.detect_encoding(): 17a0. to get the
encoding of the file; in the absence of an encoding token, the file
encoding defaults to UTF-8.

The *note linecache: 89. module defines the following functions:

 -- Funzione: linecache.getline (filename, lineno, module_globals=None)

     Get line 'lineno' from file named 'filename'.  This function will
     never raise an exception — it will return ‘''’ on errors (the
     terminating newline character will be included for lines that are
     found).

     If 'filename' indicates a frozen module (starting with ‘'<frozen
     '’), the function will attempt to get the real file name from
     ‘module_globals['__file__']’ if 'module_globals' is not ‘None’.

     If a file named 'filename' is not found, the function first checks
     for a PEP 302(2) ‘__loader__’ in 'module_globals'.  If there is
     such a loader and it defines a ‘get_source’ method, then that
     determines the source lines (if ‘get_source()’ returns ‘None’, then
     ‘''’ is returned).  Finally, if 'filename' is a relative filename,
     it is looked up relative to the entries in the module search path,
     ‘sys.path’.

     Cambiato nella versione 3.14: Support 'filename' of frozen modules.

 -- Funzione: linecache.clearcache ()

     Clear the cache.  Use this function if you no longer need lines
     from files previously read using *note getline(): 240.

 -- Funzione: linecache.checkcache (filename=None)

     Check the cache for validity.  Use this function if files in the
     cache may have changed on disk, and you require the updated
     version.  If 'filename' is omitted, it will check all the entries
     in the cache.

 -- Funzione: linecache.lazycache (filename, module_globals)

     Capture enough detail about a non-file-based module to permit
     getting its lines later via *note getline(): 240. even if
     'module_globals' is ‘None’ in the later call.  This avoids doing
     I/O until a line is actually needed, without having to carry the
     module globals around indefinitely.

     Added in version 3.5.

Example:

     >>> import linecache
     >>> linecache.getline(linecache.__file__, 8)
     'import sys\n'

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/linecache.py

   (2) https://peps.python.org/pep-0302/


File: python.info,  Node: shutil — High-level file operations,  Prev: linecache — Random access to text lines,  Up: File and Directory Access

5.11.9 ‘shutil’ — High-level file operations
--------------------------------------------

'Source code:' Lib/shutil.py(1)

__________________________________________________________________

The *note shutil: ca. module offers a number of high-level operations on
files and collections of files.  In particular, functions are provided
which support file copying and removal.  For operations on individual
files, see also the *note os: a5. module.

     Avvertimento: Even the higher-level file copying functions (*note
     shutil.copy(): c51, *note shutil.copy2(): c52.) cannot copy all
     file metadata.

     On POSIX platforms, this means that file owner and group are lost
     as well as ACLs.  On Mac OS, the resource fork and other metadata
     are not used.  This means that resources will be lost and file type
     and creator codes will not be correct.  On Windows, file owners,
     ACLs and alternate data streams are not copied.

* Menu:

* Directory and files operations::
* Archiving operations::
* Querying the size of the output terminal::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/shutil.py


File: python.info,  Node: Directory and files operations,  Next: Archiving operations,  Up: shutil — High-level file operations

5.11.9.1 Directory and files operations
.......................................

 -- Funzione: shutil.copyfileobj (fsrc, fdst[, length])

     Copy the contents of the *note file-like object: 13cb. 'fsrc' to
     the file-like object 'fdst'.  The integer 'length', if given, is
     the buffer size.  In particular, a negative 'length' value means to
     copy the data without looping over the source data in chunks; by
     default the data is read in chunks to avoid uncontrolled memory
     consumption.  Note that if the current file position of the 'fsrc'
     object is not 0, only the contents from the current file position
     to the end of the file will be copied.

     *note copyfileobj(): c54. will 'not' guarantee that the destination
     stream has been flushed on completion of the copy.  If you want to
     read from the destination at the completion of the copy operation
     (for example, reading the contents of a temporary file that has
     been copied from a HTTP stream), you must ensure that you have
     called *note flush(): 2ccc. or *note close(): 507. on the file-like
     object before attempting to read the destination file.

 -- Funzione: shutil.copyfile (src, dst, *, follow_symlinks=True)

     Copy the contents (no metadata) of the file named 'src' to a file
     named 'dst' and return 'dst' in the most efficient way possible.
     'src' and 'dst' are *note path-like objects: 5a1. or path names
     given as strings.

     'dst' must be the complete target file name; look at *note copy():
     c51. for a copy that accepts a target directory path.  If 'src' and
     'dst' specify the same file, *note SameFileError: 11a0. is raised.

     The destination location must be writable; otherwise, an *note
     OSError: 2c0. exception will be raised.  If 'dst' already exists,
     it will be replaced.  Special files such as character or block
     devices and pipes cannot be copied with this function.

     If 'follow_symlinks' is false and 'src' is a symbolic link, a new
     symbolic link will be created instead of copying the file 'src'
     points to.

     Raises an *note auditing event: 1c56. ‘shutil.copyfile’ with
     arguments ‘src’, ‘dst’.

     Cambiato nella versione 3.3: *note IOError: 1255. used to be raised
     instead of *note OSError: 2c0.  Added 'follow_symlinks' argument.
     Now returns 'dst'.

     Cambiato nella versione 3.4: Raise *note SameFileError: 11a0.
     instead of *note Error: 119f.  Since the former is a subclass of
     the latter, this change is backward compatible.

     Cambiato nella versione 3.8: Platform-specific fast-copy syscalls
     may be used internally in order to copy the file more efficiently.
     See *note Platform-dependent efficient copy operations: c55.
     section.

 -- Eccezione: shutil.SpecialFileError

     This exception is raised when *note copyfile(): c50. or *note
     copytree(): c20. attempt to copy a named pipe.

     Added in version 2.7.

 -- Eccezione: shutil.SameFileError

     This exception is raised if source and destination in *note
     copyfile(): c50. are the same file.

     Added in version 3.4.

 -- Funzione: shutil.copymode (src, dst, *, follow_symlinks=True)

     Copy the permission bits from 'src' to 'dst'.  The file contents,
     owner, and group are unaffected.  'src' and 'dst' are *note
     path-like objects: 5a1. or path names given as strings.  If
     'follow_symlinks' is false, and both 'src' and 'dst' are symbolic
     links, *note copymode(): 1a0c. will attempt to modify the mode of
     'dst' itself (rather than the file it points to).  This
     functionality is not available on every platform; please see *note
     copystat(): 1336. for more information.  If *note copymode(): 1a0c.
     cannot modify symbolic links on the local platform, and it is asked
     to do so, it will do nothing and return.

     Raises an *note auditing event: 1c56. ‘shutil.copymode’ with
     arguments ‘src’, ‘dst’.

     Cambiato nella versione 3.3: Added 'follow_symlinks' argument.

 -- Funzione: shutil.copystat (src, dst, *, follow_symlinks=True)

     Copy the permission bits, last access time, last modification time,
     and flags from 'src' to 'dst'.  On Linux, *note copystat(): 1336.
     also copies the «extended attributes» where possible.  The file
     contents, owner, and group are unaffected.  'src' and 'dst' are
     *note path-like objects: 5a1. or path names given as strings.

     If 'follow_symlinks' is false, and 'src' and 'dst' both refer to
     symbolic links, *note copystat(): 1336. will operate on the
     symbolic links themselves rather than the files the symbolic links
     refer to—reading the information from the 'src' symbolic link, and
     writing the information to the 'dst' symbolic link.

          Nota: Not all platforms provide the ability to examine and
          modify symbolic links.  Python itself can tell you what
          functionality is locally available.

             * If ‘os.chmod in os.supports_follow_symlinks’ is ‘True’,
               *note copystat(): 1336. can modify the permission bits of
               a symbolic link.

             * If ‘os.utime in os.supports_follow_symlinks’ is ‘True’,
               *note copystat(): 1336. can modify the last access and
               modification times of a symbolic link.

             * If ‘os.chflags in os.supports_follow_symlinks’ is ‘True’,
               *note copystat(): 1336. can modify the flags of a
               symbolic link.  (‘os.chflags’ is not available on all
               platforms.)

          On platforms where some or all of this functionality is
          unavailable, when asked to modify a symbolic link, *note
          copystat(): 1336. will copy everything it can.  *note
          copystat(): 1336. never returns failure.

          Please see *note os.supports_follow_symlinks: 1300. for more
          information.

     Raises an *note auditing event: 1c56. ‘shutil.copystat’ with
     arguments ‘src’, ‘dst’.

     Cambiato nella versione 3.3: Added 'follow_symlinks' argument and
     support for Linux extended attributes.

 -- Funzione: shutil.copy (src, dst, *, follow_symlinks=True)

     Copies the file 'src' to the file or directory 'dst'.  'src' and
     'dst' should be *note path-like objects: 5a1. or strings.  If 'dst'
     specifies a directory, the file will be copied into 'dst' using the
     base filename from 'src'.  If 'dst' specifies a file that already
     exists, it will be replaced.  Returns the path to the newly created
     file.

     If 'follow_symlinks' is false, and 'src' is a symbolic link, 'dst'
     will be created as a symbolic link.  If 'follow_symlinks' is true
     and 'src' is a symbolic link, 'dst' will be a copy of the file
     'src' refers to.

     *note copy(): c51. copies the file data and the file’s permission
     mode (see *note os.chmod(): 52a.).  Other metadata, like the file’s
     creation and modification times, is not preserved.  To preserve all
     file metadata from the original, use *note copy2(): c52. instead.

     Raises an *note auditing event: 1c56. ‘shutil.copyfile’ with
     arguments ‘src’, ‘dst’.

     Raises an *note auditing event: 1c56. ‘shutil.copymode’ with
     arguments ‘src’, ‘dst’.

     Cambiato nella versione 3.3: Added 'follow_symlinks' argument.  Now
     returns path to the newly created file.

     Cambiato nella versione 3.8: Platform-specific fast-copy syscalls
     may be used internally in order to copy the file more efficiently.
     See *note Platform-dependent efficient copy operations: c55.
     section.

 -- Funzione: shutil.copy2 (src, dst, *, follow_symlinks=True)

     Identical to *note copy(): c51. except that *note copy2(): c52.
     also attempts to preserve file metadata.

     When 'follow_symlinks' is false, and 'src' is a symbolic link,
     *note copy2(): c52. attempts to copy all metadata from the 'src'
     symbolic link to the newly created 'dst' symbolic link.  However,
     this functionality is not available on all platforms.  On platforms
     where some or all of this functionality is unavailable, *note
     copy2(): c52. will preserve all the metadata it can; *note copy2():
     c52. never raises an exception because it cannot preserve file
     metadata.

     *note copy2(): c52. uses *note copystat(): 1336. to copy the file
     metadata.  Please see *note copystat(): 1336. for more information
     about platform support for modifying symbolic link metadata.

     Raises an *note auditing event: 1c56. ‘shutil.copyfile’ with
     arguments ‘src’, ‘dst’.

     Raises an *note auditing event: 1c56. ‘shutil.copystat’ with
     arguments ‘src’, ‘dst’.

     Cambiato nella versione 3.3: Added 'follow_symlinks' argument, try
     to copy extended file system attributes too (currently Linux only).
     Now returns path to the newly created file.

     Cambiato nella versione 3.8: Platform-specific fast-copy syscalls
     may be used internally in order to copy the file more efficiently.
     See *note Platform-dependent efficient copy operations: c55.
     section.

 -- Funzione: shutil.ignore_patterns (*patterns)

     This factory function creates a function that can be used as a
     callable for *note copytree(): c20.'s 'ignore' argument, ignoring
     files and directories that match one of the glob-style 'patterns'
     provided.  See the example below.

 -- Funzione: shutil.copytree (src, dst, symlinks=False, ignore=None,
          copy_function=copy2, ignore_dangling_symlinks=False,
          dirs_exist_ok=False)

     Recursively copy an entire directory tree rooted at 'src' to a
     directory named 'dst' and return the destination directory.  All
     intermediate directories needed to contain 'dst' will also be
     created by default.

     Permissions and times of directories are copied with *note
     copystat(): 1336, individual files are copied using *note copy2():
     c52.

     If 'symlinks' is true, symbolic links in the source tree are
     represented as symbolic links in the new tree and the metadata of
     the original links will be copied as far as the platform allows; if
     false or omitted, the contents and metadata of the linked files are
     copied to the new tree.

     When 'symlinks' is false, if the file pointed to by the symlink
     doesn’t exist, an exception will be added in the list of errors
     raised in an *note Error: 119f. exception at the end of the copy
     process.  You can set the optional 'ignore_dangling_symlinks' flag
     to true if you want to silence this exception.  Notice that this
     option has no effect on platforms that don’t support *note
     os.symlink(): 12fc.

     If 'ignore' is given, it must be a callable that will receive as
     its arguments the directory being visited by *note copytree(): c20,
     and a list of its contents, as returned by *note os.listdir():
     1302.  Since *note copytree(): c20. is called recursively, the
     'ignore' callable will be called once for each directory that is
     copied.  The callable must return a sequence of directory and file
     names relative to the current directory (i.e.  a subset of the
     items in its second argument); these names will then be ignored in
     the copy process.  *note ignore_patterns(): 2ccd. can be used to
     create such a callable that ignores names based on glob-style
     patterns.

     If exception(s) occur, an *note Error: 119f. is raised with a list
     of reasons.

     If 'copy_function' is given, it must be a callable that will be
     used to copy each file.  It will be called with the source path and
     the destination path as arguments.  By default, *note copy2(): c52.
     is used, but any function that supports the same signature (like
     *note copy(): c51.) can be used.

     If 'dirs_exist_ok' is false (the default) and 'dst' already exists,
     a *note FileExistsError: 1222. is raised.  If 'dirs_exist_ok' is
     true, the copying operation will continue if it encounters existing
     directories, and files within the 'dst' tree will be overwritten by
     corresponding files from the 'src' tree.

     Raises an *note auditing event: 1c56. ‘shutil.copytree’ with
     arguments ‘src’, ‘dst’.

     Cambiato nella versione 3.2: Added the 'copy_function' argument to
     be able to provide a custom copy function.  Added the
     'ignore_dangling_symlinks' argument to silence dangling symlinks
     errors when 'symlinks' is false.

     Cambiato nella versione 3.3: Copy metadata when 'symlinks' is
     false.  Now returns 'dst'.

     Cambiato nella versione 3.8: Platform-specific fast-copy syscalls
     may be used internally in order to copy the file more efficiently.
     See *note Platform-dependent efficient copy operations: c55.
     section.

     Cambiato nella versione 3.8: Added the 'dirs_exist_ok' parameter.

 -- Funzione: shutil.rmtree (path, ignore_errors=False, onerror=None, *,
          onexc=None, dir_fd=None)

     Delete an entire directory tree; 'path' must point to a directory
     (but not a symbolic link to a directory).  If 'ignore_errors' is
     true, errors resulting from failed removals will be ignored; if
     false or omitted, such errors are handled by calling a handler
     specified by 'onexc' or 'onerror' or, if both are omitted,
     exceptions are propagated to the caller.

     This function can support *note paths relative to directory
     descriptors: 12f2.

          Nota: On platforms that support the necessary fd-based
          functions a symlink attack resistant version of *note
          rmtree(): 356. is used by default.  On other platforms, the
          *note rmtree(): 356. implementation is susceptible to a
          symlink attack: given proper timing and circumstances,
          attackers can manipulate symlinks on the filesystem to delete
          files they wouldn’t be able to access otherwise.  Applications
          can use the *note rmtree.avoids_symlink_attacks: 2cce.
          function attribute to determine which case applies.

     If 'onexc' is provided, it must be a callable that accepts three
     parameters: 'function', 'path', and 'excinfo'.

     The first parameter, 'function', is the function which raised the
     exception; it depends on the platform and implementation.  The
     second parameter, 'path', will be the path name passed to
     'function'.  The third parameter, 'excinfo', is the exception that
     was raised.  Exceptions raised by 'onexc' will not be caught.

     The deprecated 'onerror' is similar to 'onexc', except that the
     third parameter it receives is the tuple returned from *note
     sys.exc_info(): 89b.

     Vedi anche
     ..........

     *note rmtree example: 2ccf. for an example of handling the removal
     of a directory tree that contains read-only files.

     Raises an *note auditing event: 1c56. ‘shutil.rmtree’ with
     arguments ‘path’, ‘dir_fd’.

     Cambiato nella versione 3.3: Added a symlink attack resistant
     version that is used automatically if platform supports fd-based
     functions.

     Cambiato nella versione 3.8: On Windows, will no longer delete the
     contents of a directory junction before removing the junction.

     Cambiato nella versione 3.11: Added the 'dir_fd' parameter.

     Cambiato nella versione 3.12: Added the 'onexc' parameter,
     deprecated 'onerror'.

     Cambiato nella versione 3.13: ‘rmtree()’ now ignores *note
     FileNotFoundError: 264. exceptions for all but the top-level path.
     Exceptions other than *note OSError: 2c0. and subclasses of
     ‘OSError’ are now always propagated to the caller.

      -- Attributo: rmtree.avoids_symlink_attacks

          Indicates whether the current platform and implementation
          provides a symlink attack resistant version of *note rmtree():
          356.  Currently this is only true for platforms supporting
          fd-based directory access functions.

          Added in version 3.3.

 -- Funzione: shutil.move (src, dst, copy_function=copy2)

     Recursively move a file or directory ('src') to another location
     and return the destination.

     If 'dst' is an existing directory or a symlink to a directory, then
     'src' is moved inside that directory.  The destination path in that
     directory must not already exist.

     If 'dst' already exists but is not a directory, it may be
     overwritten depending on *note os.rename(): 12f9. semantics.

     If the destination is on the current filesystem, then *note
     os.rename(): 12f9. is used.  Otherwise, 'src' is copied to the
     destination using 'copy_function' and then removed.  In case of
     symlinks, a new symlink pointing to the target of 'src' will be
     created as the destination and 'src' will be removed.

     If 'copy_function' is given, it must be a callable that takes two
     arguments, 'src' and the destination, and will be used to copy
     'src' to the destination if *note os.rename(): 12f9. cannot be
     used.  If the source is a directory, *note copytree(): c20. is
     called, passing it the 'copy_function'.  The default
     'copy_function' is *note copy2(): c52.  Using *note copy(): c51. as
     the 'copy_function' allows the move to succeed when it is not
     possible to also copy the metadata, at the expense of not copying
     any of the metadata.

     Raises an *note auditing event: 1c56. ‘shutil.move’ with arguments
     ‘src’, ‘dst’.

     Cambiato nella versione 3.3: Added explicit symlink handling for
     foreign filesystems, thus adapting it to the behavior of GNU’s
     ‘mv’.  Now returns 'dst'.

     Cambiato nella versione 3.5: Added the 'copy_function' keyword
     argument.

     Cambiato nella versione 3.8: Platform-specific fast-copy syscalls
     may be used internally in order to copy the file more efficiently.
     See *note Platform-dependent efficient copy operations: c55.
     section.

     Cambiato nella versione 3.9: Accepts a *note path-like object: 5a1.
     for both 'src' and 'dst'.

 -- Funzione: shutil.disk_usage (path)

     Return disk usage statistics about the given path as a *note named
     tuple: 85f. with the attributes 'total', 'used' and 'free', which
     are the amount of total, used and free space, in bytes.  'path' may
     be a file or a directory.

          Nota: On Unix filesystems, 'path' must point to a path within
          a 'mounted' filesystem partition.  On those platforms, CPython
          doesn’t attempt to retrieve disk usage information from
          non-mounted filesystems.

     Added in version 3.3.

     Cambiato nella versione 3.8: On Windows, 'path' can now be a file
     or directory.

     *note Availability: 2128.: Unix, Windows.

 -- Funzione: shutil.chown (path, user=None, group=None, *, dir_fd=None,
          follow_symlinks=True)

     Change owner 'user' and/or 'group' of the given 'path'.

     'user' can be a system user name or a uid; the same applies to
     'group'.  At least one argument is required.

     See also *note os.chown(): 12f6, the underlying function.

     Raises an *note auditing event: 1c56. ‘shutil.chown’ with arguments
     ‘path’, ‘user’, ‘group’.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

     Cambiato nella versione 3.13: Added 'dir_fd' and 'follow_symlinks'
     parameters.

 -- Funzione: shutil.which (cmd, mode=os.F_OK | os.X_OK, path=None)

     Return the path to an executable which would be run if the given
     'cmd' was called.  If no 'cmd' would be called, return ‘None’.

     'mode' is a permission mask passed to *note os.access(): 12f4, by
     default determining if the file exists and is executable.

     'path' is a «‘PATH’ string» specifying the directories to look in,
     delimited by *note os.pathsep: 211d.  When no 'path' is specified,
     the ‘PATH’ environment variable is read from *note os.environ: 259,
     falling back to *note os.defpath: 1dcc. if it is not set.

     If 'cmd' contains a directory component, ‘which()’ only checks the
     specified path directly and does not search the directories listed
     in 'path' or in the system’s ‘PATH’ environment variable.

     On Windows, the current directory is prepended to the 'path' if
     'mode' does not include ‘os.X_OK’.  When the 'mode' does include
     ‘os.X_OK’, the Windows API ‘NeedCurrentDirectoryForExePathW’ will
     be consulted to determine if the current directory should be
     prepended to 'path'.  To avoid consulting the current working
     directory for executables: set the environment variable
     ‘NoDefaultCurrentDirectoryInExePath’.

     Also on Windows, the ‘PATHEXT’ environment variable is used to
     resolve commands that may not already include an extension.  For
     example, if you call ‘shutil.which("python")’, *note which(): 6dc.
     will search ‘PATHEXT’ to know that it should look for ‘python.exe’
     within the 'path' directories.  For example, on Windows:

          >>> shutil.which("python")
          'C:\\Python33\\python.EXE'

     This is also applied when 'cmd' is a path that contains a directory
     component:

          >>> shutil.which("C:\\Python33\\python")
          'C:\\Python33\\python.EXE'

     Added in version 3.3.

     Cambiato nella versione 3.8: The *note bytes: 192. type is now
     accepted.  If 'cmd' type is *note bytes: 192, the result type is
     also *note bytes: 192.

     Cambiato nella versione 3.12: On Windows, the current directory is
     no longer prepended to the search path if 'mode' includes ‘os.X_OK’
     and WinAPI ‘NeedCurrentDirectoryForExePathW(cmd)’ is false, else
     the current directory is prepended even if it is already in the
     search path; ‘PATHEXT’ is used now even when 'cmd' includes a
     directory component or ends with an extension that is in ‘PATHEXT’;
     and filenames that have no extension can now be found.

 -- Eccezione: shutil.Error

     This exception collects exceptions that are raised during a
     multi-file operation.  For *note copytree(): c20, the exception
     argument is a list of 3-tuples ('srcname', 'dstname', 'exception').

* Menu:

* Platform-dependent efficient copy operations::
* copytree example::
* rmtree example::


File: python.info,  Node: Platform-dependent efficient copy operations,  Next: copytree example,  Up: Directory and files operations

5.11.9.2 Platform-dependent efficient copy operations
.....................................................

Starting from Python 3.8, all functions involving a file copy (*note
copyfile(): c50, *note copy(): c51, *note copy2(): c52, *note
copytree(): c20, and *note move(): c53.) may use platform-specific
«fast-copy» syscalls in order to copy the file more efficiently (see
bpo-33671(1)).  «fast-copy» means that the copying operation occurs
within the kernel, avoiding the use of userspace buffers in Python as in
«‘outfd.write(infd.read())’».

On macOS fcopyfile(2) is used to copy the file content (not metadata).

On Linux *note os.copy_file_range(): 189c. or *note os.sendfile(): d07.
is used.

On Solaris *note os.sendfile(): d07. is used.

On Windows *note shutil.copyfile(): c50. uses a bigger default buffer
size (1 MiB instead of 64 KiB) and a *note memoryview(): 165.-based
variant of *note shutil.copyfileobj(): c54. is used.

If the fast-copy operation fails and no data was written in the
destination file then shutil will silently fallback on using less
efficient *note copyfileobj(): c54. function internally.

Cambiato nella versione 3.8.

Cambiato nella versione 3.14: Solaris now uses *note os.sendfile(): d07.

Cambiato nella versione 3.14: Copy-on-write or server-side copy may be
used internally via *note os.copy_file_range(): 189c. on supported Linux
filesystems.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33671

   (2) http://www.manpagez.com/man/3/copyfile/


File: python.info,  Node: copytree example,  Next: rmtree example,  Prev: Platform-dependent efficient copy operations,  Up: Directory and files operations

5.11.9.3 copytree example
.........................

An example that uses the *note ignore_patterns(): 2ccd. helper:

     from shutil import copytree, ignore_patterns

     copytree(source, destination, ignore=ignore_patterns('*.pyc', 'tmp*'))

This will copy everything except ‘.pyc’ files and files or directories
whose name starts with ‘tmp’.

Another example that uses the 'ignore' argument to add a logging call:

     from shutil import copytree
     import logging

     def _logpath(path, names):
         logging.info('Working in %s', path)
         return []   # nothing will be ignored

     copytree(source, destination, ignore=_logpath)


File: python.info,  Node: rmtree example,  Prev: copytree example,  Up: Directory and files operations

5.11.9.4 rmtree example
.......................

This example shows how to remove a directory tree on Windows where some
of the files have their read-only bit set.  It uses the onexc callback
to clear the readonly bit and reattempt the remove.  Any subsequent
failure will propagate.

     import os, stat
     import shutil

     def remove_readonly(func, path, _):
         "Clear the readonly bit and reattempt the removal"
         os.chmod(path, stat.S_IWRITE)
         func(path)

     shutil.rmtree(directory, onexc=remove_readonly)


File: python.info,  Node: Archiving operations,  Next: Querying the size of the output terminal,  Prev: Directory and files operations,  Up: shutil — High-level file operations

5.11.9.5 Archiving operations
.............................

Added in version 3.2.

Cambiato nella versione 3.5: Added support for the 'xztar' format.

High-level utilities to create and read compressed and archived files
are also provided.  They rely on the *note zipfile: 137. and *note
tarfile: e4. modules.

 -- Funzione: shutil.make_archive (base_name, format[, root_dir[,
          base_dir[, verbose[, dry_run[, owner[, group[, logger]]]]]]])

     Create an archive file (such as zip or tar) and return its name.

     'base_name' is the name of the file to create, including the path,
     minus any format-specific extension.

     'format' is the archive format: one of «zip» (if the *note zlib:
     139. module is available), «tar», «gztar» (if the *note zlib: 139.
     module is available), «bztar» (if the *note bz2: 14. module is
     available), «xztar» (if the *note lzma: 8e. module is available),
     or «zstdtar» (if the *note compression.zstd: 23. module is
     available).

     'root_dir' is a directory that will be the root directory of the
     archive, all paths in the archive will be relative to it; for
     example, we typically chdir into 'root_dir' before creating the
     archive.

     'base_dir' is the directory where we start archiving from; i.e.
     'base_dir' will be the common prefix of all files and directories
     in the archive.  'base_dir' must be given relative to 'root_dir'.
     See *note Archiving example with base_dir: 2cd5. for how to use
     'base_dir' and 'root_dir' together.

     'root_dir' and 'base_dir' both default to the current directory.

     If 'dry_run' is true, no archive is created, but the operations
     that would be executed are logged to 'logger'.

     'owner' and 'group' are used when creating a tar archive.  By
     default, uses the current owner and group.

     'logger' must be an object compatible with PEP 282(1), usually an
     instance of *note logging.Logger: d48.

     The 'verbose' argument is unused and deprecated.

     Raises an *note auditing event: 1c56. ‘shutil.make_archive’ with
     arguments ‘base_name’, ‘format’, ‘root_dir’, ‘base_dir’.

          Nota: This function is not thread-safe when custom archivers
          registered with *note register_archive_format(): 2cd6. do not
          support the 'root_dir' argument.  In this case it temporarily
          changes the current working directory of the process to
          'root_dir' to perform archiving.

     Cambiato nella versione 3.8: The modern pax (POSIX.1-2001) format
     is now used instead of the legacy GNU format for archives created
     with ‘format="tar"’.

     Cambiato nella versione 3.10.6: This function is now made
     thread-safe during creation of standard ‘.zip’ and tar archives.

 -- Funzione: shutil.get_archive_formats ()

     Return a list of supported formats for archiving.  Each element of
     the returned sequence is a tuple ‘(name, description)’.

     By default *note shutil: ca. provides these formats:

        - 'zip': ZIP file (if the *note zlib: 139. module is available).

        - 'tar': Uncompressed tar file.  Uses POSIX.1-2001 pax format
          for new archives.

        - 'gztar': gzip’ed tar-file (if the *note zlib: 139. module is
          available).

        - 'bztar': bzip2’ed tar-file (if the *note bz2: 14. module is
          available).

        - 'xztar': xz’ed tar-file (if the *note lzma: 8e. module is
          available).

        - 'zstdtar': Zstandard compressed tar-file (if the *note
          compression.zstd: 23. module is available).

     You can register new formats or provide your own archiver for any
     existing formats, by using *note register_archive_format(): 2cd6.

 -- Funzione: shutil.register_archive_format (name, function[,
          extra_args[, description]])

     Register an archiver for the format 'name'.

     'function' is the callable that will be used to unpack archives.
     The callable will receive the 'base_name' of the file to create,
     followed by the 'base_dir' (which defaults to *note os.curdir:
     2c3d.) to start archiving from.  Further arguments are passed as
     keyword arguments: 'owner', 'group', 'dry_run' and 'logger' (as
     passed in *note make_archive(): 6db.).

     If 'function' has the custom attribute ‘function.supports_root_dir’
     set to ‘True’, the 'root_dir' argument is passed as a keyword
     argument.  Otherwise the current working directory of the process
     is temporarily changed to 'root_dir' before calling 'function'.  In
     this case *note make_archive(): 6db. is not thread-safe.

     If given, 'extra_args' is a sequence of ‘(name, value)’ pairs that
     will be used as extra keywords arguments when the archiver callable
     is used.

     'description' is used by *note get_archive_formats(): 2cd7. which
     returns the list of archivers.  Defaults to an empty string.

     Cambiato nella versione 3.12: Added support for functions
     supporting the 'root_dir' argument.

 -- Funzione: shutil.unregister_archive_format (name)

     Remove the archive format 'name' from the list of supported
     formats.

 -- Funzione: shutil.unpack_archive (filename[, extract_dir[, format[,
          filter]]])

     Unpack an archive.  'filename' is the full path of the archive.

     'extract_dir' is the name of the target directory where the archive
     is unpacked.  If not provided, the current working directory is
     used.

     'format' is the archive format: one of «zip», «tar», «gztar»,
     «bztar», «xztar», or «zstdtar».  Or any other format registered
     with *note register_unpack_format(): 2cd9.  If not provided, *note
     unpack_archive(): 697. will use the archive file name extension and
     see if an unpacker was registered for that extension.  In case none
     is found, a *note ValueError: 2ec. is raised.

     The keyword-only 'filter' argument is passed to the underlying
     unpacking function.  For zip files, 'filter' is not accepted.  For
     tar files, it is recommended to use ‘'data'’ (default since Python
     3.14), unless using features specific to tar and UNIX-like
     filesystems.  (See *note Extraction filters: 698. for details.)

     Raises an *note auditing event: 1c56. ‘shutil.unpack_archive’ with
     arguments ‘filename’, ‘extract_dir’, ‘format’.

          Avvertimento: Never extract archives from untrusted sources
          without prior inspection.  It is possible that files are
          created outside of the path specified in the 'extract_dir'
          argument, e.g.  members that have absolute filenames starting
          with «/» or filenames with two dots «..».

          Since Python 3.14, the defaults for both built-in formats (zip
          and tar files) will prevent the most dangerous of such
          security issues, but will not prevent 'all' unintended
          behavior.  Read the *note Hints for further verification:
          2cda. section for tar-specific details.

     Cambiato nella versione 3.7: Accepts a *note path-like object: 5a1.
     for 'filename' and 'extract_dir'.

     Cambiato nella versione 3.12: Added the 'filter' argument.

 -- Funzione: shutil.register_unpack_format (name, extensions,
          function[, extra_args[, description]])

     Registers an unpack format.  'name' is the name of the format and
     'extensions' is a list of extensions corresponding to the format,
     like ‘.zip’ for Zip files.

     'function' is the callable that will be used to unpack archives.
     The callable will receive:

        - the path of the archive, as a positional argument;

        - the directory the archive must be extracted to, as a
          positional argument;

        - possibly a 'filter' keyword argument, if it was given to *note
          unpack_archive(): 697.;

        - additional keyword arguments, specified by 'extra_args' as a
          sequence of ‘(name, value)’ tuples.

     'description' can be provided to describe the format, and will be
     returned by the *note get_unpack_formats(): 2cdb. function.

 -- Funzione: shutil.unregister_unpack_format (name)

     Unregister an unpack format.  'name' is the name of the format.

 -- Funzione: shutil.get_unpack_formats ()

     Return a list of all registered formats for unpacking.  Each
     element of the returned sequence is a tuple ‘(name, extensions,
     description)’.

     By default *note shutil: ca. provides these formats:

        - 'zip': ZIP file (unpacking compressed files works only if the
          corresponding module is available).

        - 'tar': uncompressed tar file.

        - 'gztar': gzip’ed tar-file (if the *note zlib: 139. module is
          available).

        - 'bztar': bzip2’ed tar-file (if the *note bz2: 14. module is
          available).

        - 'xztar': xz’ed tar-file (if the *note lzma: 8e. module is
          available).

        - 'zstdtar': Zstandard compressed tar-file (if the *note
          compression.zstd: 23. module is available).

     You can register new formats or provide your own unpacker for any
     existing formats, by using *note register_unpack_format(): 2cd9.

* Menu:

* Archiving example::
* Archiving example with base_dir::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0282/


File: python.info,  Node: Archiving example,  Next: Archiving example with base_dir,  Up: Archiving operations

5.11.9.6 Archiving example
..........................

In this example, we create a gzip’ed tar-file archive containing all
files found in the ‘.ssh’ directory of the user:

     >>> from shutil import make_archive
     >>> import os
     >>> archive_name = os.path.expanduser(os.path.join('~', 'myarchive'))
     >>> root_dir = os.path.expanduser(os.path.join('~', '.ssh'))
     >>> make_archive(archive_name, 'gztar', root_dir)
     '/Users/tarek/myarchive.tar.gz'

The resulting archive contains:

     $ tar -tzvf /Users/tarek/myarchive.tar.gz
     drwx------ tarek/staff       0 2010-02-01 16:23:40 ./
     -rw-r--r-- tarek/staff     609 2008-06-09 13:26:54 ./authorized_keys
     -rwxr-xr-x tarek/staff      65 2008-06-09 13:26:54 ./config
     -rwx------ tarek/staff     668 2008-06-09 13:26:54 ./id_dsa
     -rwxr-xr-x tarek/staff     609 2008-06-09 13:26:54 ./id_dsa.pub
     -rw------- tarek/staff    1675 2008-06-09 13:26:54 ./id_rsa
     -rw-r--r-- tarek/staff     397 2008-06-09 13:26:54 ./id_rsa.pub
     -rw-r--r-- tarek/staff   37192 2010-02-06 18:23:10 ./known_hosts


File: python.info,  Node: Archiving example with base_dir,  Prev: Archiving example,  Up: Archiving operations

5.11.9.7 Archiving example with 'base_dir'
..........................................

In this example, similar to the *note one above: 2cde, we show how to
use *note make_archive(): 6db, but this time with the usage of
'base_dir'.  We now have the following directory structure:

     $ tree tmp
     tmp
     └── root
         └── structure
             ├── content
                 └── please_add.txt
             └── do_not_add.txt

In the final archive, ‘please_add.txt’ should be included, but
‘do_not_add.txt’ should not.  Therefore we use the following:

     >>> from shutil import make_archive
     >>> import os
     >>> archive_name = os.path.expanduser(os.path.join('~', 'myarchive'))
     >>> make_archive(
     ...     archive_name,
     ...     'tar',
     ...     root_dir='tmp/root',
     ...     base_dir='structure/content',
     ... )
     '/Users/tarek/myarchive.tar'

Listing the files in the resulting archive gives us:

     $ python -m tarfile -l /Users/tarek/myarchive.tar
     structure/content/
     structure/content/please_add.txt


File: python.info,  Node: Querying the size of the output terminal,  Prev: Archiving operations,  Up: shutil — High-level file operations

5.11.9.8 Querying the size of the output terminal
.................................................

 -- Funzione: shutil.get_terminal_size (fallback=(columns, lines))

     Get the size of the terminal window.

     For each of the two dimensions, the environment variable, ‘COLUMNS’
     and ‘LINES’ respectively, is checked.  If the variable is defined
     and the value is a positive integer, it is used.

     When ‘COLUMNS’ or ‘LINES’ is not defined, which is the common case,
     the terminal connected to *note sys.__stdout__: 2ce1. is queried by
     invoking *note os.get_terminal_size(): 130a.

     If the terminal size cannot be successfully queried, either because
     the system doesn’t support querying, or because we are not
     connected to a terminal, the value given in ‘fallback’ parameter is
     used.  ‘fallback’ defaults to ‘(80, 24)’ which is the default size
     used by many terminal emulators.

     The value returned is a named tuple of type *note os.terminal_size:
     2ce2.

     See also: The Single UNIX Specification, Version 2, Other
     Environment Variables(1).

     Added in version 3.3.

     Cambiato nella versione 3.11: The ‘fallback’ values are also used
     if *note os.get_terminal_size(): 130a. returns zeroes.

Vedi anche
..........

Module *note os: a5.

     Operating system interfaces, including functions to work with files
     at a lower level than Python *note file objects: 13cb.

Module *note io: 83.

     Python’s built-in I/O library, including both abstract classes and
     some concrete classes such as file I/O.

Built-in function *note open(): 316.

     The standard way to open files for reading and writing with Python.

   ---------- Footnotes ----------

   (1) 
https://pubs.opengroup.org/onlinepubs/7908799/xbd/envvar.html#tag_002_003


File: python.info,  Node: Data Persistence,  Next: Data Compression and Archiving,  Prev: File and Directory Access,  Up: The Python Standard Library

5.12 Data Persistence
=====================

The modules described in this chapter support storing Python data in a
persistent form on disk.  The *note pickle: ab. and *note marshal: 91.
modules can turn many Python data types into a stream of bytes and then
recreate the objects from the bytes.  The various DBM-related modules
support a family of hash-based file formats that store a mapping of
strings to other strings.

The list of modules described in this chapter is:

* Menu:

* pickle — Python object serialization::
* copyreg — Register pickle support functions::
* shelve — Python object persistence::
* marshal — Internal Python object serialization::
* dbm — Interfaces to Unix «databases»::
* sqlite3 — DB-API 2.0 interface for SQLite databases: sqlite3 — DB-API 2 0 interface for SQLite databases.


File: python.info,  Node: pickle — Python object serialization,  Next: copyreg — Register pickle support functions,  Up: Data Persistence

5.12.1 ‘pickle’ — Python object serialization
---------------------------------------------

'Source code:' Lib/pickle.py(1)

__________________________________________________________________

The *note pickle: ab. module implements binary protocols for serializing
and de-serializing a Python object structure.  '«Pickling»' is the
process whereby a Python object hierarchy is converted into a byte
stream, and '«unpickling»' is the inverse operation, whereby a byte
stream (from a *note binary file: 2058. or *note bytes-like object:
193.) is converted back into an object hierarchy.  Pickling (and
unpickling) is alternatively known as «serialization», «marshalling,»
(2) or «flattening»; however, to avoid confusion, the terms used here
are «pickling» and «unpickling».

     Avvertimento: The ‘pickle’ module 'is not secure'.  Only unpickle
     data you trust.

     It is possible to construct malicious pickle data which will
     'execute arbitrary code during unpickling'.  Never unpickle data
     that could have come from an untrusted source, or that could have
     been tampered with.

     Consider signing data with *note hmac: 6e. if you need to ensure
     that it has not been tampered with.

     Safer serialization formats such as *note json: 86. may be more
     appropriate if you are processing untrusted data.  See *note
     Comparison with json: 2ce9.

* Menu:

* Relationship to other Python modules::
* Data stream format::
* Module Interface::
* What can be pickled and unpickled?::
* Pickling Class Instances::
* Custom Reduction for Types, Functions, and Other Objects: Custom Reduction for Types Functions and Other Objects.
* Out-of-band Buffers::
* Restricting Globals::
* Performance: Performance<2>.
* Examples: Examples<7>.
* Command-line interface::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/pickle.py

   (2) Don’t confuse this with the *note marshal: 91. module


File: python.info,  Node: Relationship to other Python modules,  Next: Data stream format,  Up: pickle — Python object serialization

5.12.1.1 Relationship to other Python modules
.............................................

* Menu:

* Comparison with marshal::
* Comparison with json::


File: python.info,  Node: Comparison with marshal,  Next: Comparison with json,  Up: Relationship to other Python modules

5.12.1.2 Comparison with ‘marshal’
..................................

Python has a more primitive serialization module called *note marshal:
91, but in general *note pickle: ab. should always be the preferred way
to serialize Python objects.  *note marshal: 91. exists primarily to
support Python’s ‘.pyc’ files.

The *note pickle: ab. module differs from *note marshal: 91. in several
significant ways:

   * *note marshal: 91. cannot be used to serialize user-defined classes
     and their instances.  *note pickle: ab. can save and restore class
     instances transparently, however the class definition must be
     importable and live in the same module as when the object was
     stored.

   * The *note marshal: 91. serialization format is not guaranteed to be
     portable across Python versions.  Because its primary job in life
     is to support ‘.pyc’ files, the Python implementers reserve the
     right to change the serialization format in non-backwards
     compatible ways should the need arise.  The *note pickle: ab.
     serialization format is guaranteed to be backwards compatible
     across Python releases provided a compatible pickle protocol is
     chosen and pickling and unpickling code deals with Python 2 to
     Python 3 type differences if your data is crossing that unique
     breaking change language boundary.


File: python.info,  Node: Comparison with json,  Prev: Comparison with marshal,  Up: Relationship to other Python modules

5.12.1.3 Comparison with ‘json’
...............................

There are fundamental differences between the pickle protocols and JSON
(JavaScript Object Notation)(1):

   * JSON is a text serialization format (it outputs unicode text,
     although most of the time it is then encoded to ‘utf-8’), while
     pickle is a binary serialization format;

   * JSON is human-readable, while pickle is not;

   * JSON is interoperable and widely used outside of the Python
     ecosystem, while pickle is Python-specific;

   * JSON, by default, can only represent a subset of the Python
     built-in types, and no custom classes; pickle can represent an
     extremely large number of Python types (many of them automatically,
     by clever usage of Python’s introspection facilities; complex cases
     can be tackled by implementing *note specific object APIs: 2ced.);

   * Unlike pickle, deserializing untrusted JSON does not in itself
     create an arbitrary code execution vulnerability.

Vedi anche
..........

The *note json: 86. module: a standard library module allowing JSON
serialization and deserialization.

   ---------- Footnotes ----------

   (1) https://json.org


File: python.info,  Node: Data stream format,  Next: Module Interface,  Prev: Relationship to other Python modules,  Up: pickle — Python object serialization

5.12.1.4 Data stream format
...........................

The data format used by *note pickle: ab. is Python-specific.  This has
the advantage that there are no restrictions imposed by external
standards such as JSON (which can’t represent pointer sharing); however
it means that non-Python programs may not be able to reconstruct pickled
Python objects.

By default, the *note pickle: ab. data format uses a relatively compact
binary representation.  If you need optimal size characteristics, you
can efficiently *note compress: 2cef. pickled data.

The module *note pickletools: ac. contains tools for analyzing data
streams generated by *note pickle: ab.  *note pickletools: ac. source
code has extensive comments about opcodes used by pickle protocols.

There are currently 6 different protocols which can be used for
pickling.  The higher the protocol used, the more recent the version of
Python needed to read the pickle produced.

   * Protocol version 0 is the original «human-readable» protocol and is
     backwards compatible with earlier versions of Python.

   * Protocol version 1 is an old binary format which is also compatible
     with earlier versions of Python.

   * Protocol version 2 was introduced in Python 2.3.  It provides much
     more efficient pickling of *note new-style classes: 2cf0.  Refer to
     PEP 307(1) for information about improvements brought by protocol
     2.

   * Protocol version 3 was added in Python 3.0.  It has explicit
     support for *note bytes: 192. objects and cannot be unpickled by
     Python 2.x.  This was the default protocol in Python 3.0–3.7.

   * Protocol version 4 was added in Python 3.4.  It adds support for
     very large objects, pickling more kinds of objects, and some data
     format optimizations.  This was the default protocol in Python
     3.8–3.13.  Refer to PEP 3154(2) for information about improvements
     brought by protocol 4.

   * Protocol version 5 was added in Python 3.8.  It adds support for
     out-of-band data and speedup for in-band data.  It is the default
     protocol starting with Python 3.14.  Refer to PEP 574(3) for
     information about improvements brought by protocol 5.

     Nota: Serialization is a more primitive notion than persistence;
     although *note pickle: ab. reads and writes file objects, it does
     not handle the issue of naming persistent objects, nor the (even
     more complicated) issue of concurrent access to persistent objects.
     The *note pickle: ab. module can transform a complex object into a
     byte stream and it can transform the byte stream into an object
     with the same internal structure.  Perhaps the most obvious thing
     to do with these byte streams is to write them onto a file, but it
     is also conceivable to send them across a network or store them in
     a database.  The *note shelve: c8. module provides a simple
     interface to pickle and unpickle objects on DBM-style database
     files.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0307/

   (2) https://peps.python.org/pep-3154/

   (3) https://peps.python.org/pep-0574/


File: python.info,  Node: Module Interface,  Next: What can be pickled and unpickled?,  Prev: Data stream format,  Up: pickle — Python object serialization

5.12.1.5 Module Interface
.........................

To serialize an object hierarchy, you simply call the *note dumps():
16ab. function.  Similarly, to de-serialize a data stream, you call the
*note loads(): f0f. function.  However, if you want more control over
serialization and de-serialization, you can create a *note Pickler: c15.
or an *note Unpickler: 175e. object, respectively.

The *note pickle: ab. module provides the following constants:

 -- Dati: pickle.HIGHEST_PROTOCOL

     An integer, the highest *note protocol version: 27b. available.
     This value can be passed as a 'protocol' value to functions *note
     dump(): 2cf2. and *note dumps(): 16ab. as well as the *note
     Pickler: c15. constructor.

 -- Dati: pickle.DEFAULT_PROTOCOL

     An integer, the default *note protocol version: 27b. used for
     pickling.  May be less than *note HIGHEST_PROTOCOL: 16ac.
     Currently the default protocol is 5, introduced in Python 3.8 and
     incompatible with previous versions.  This version introduces
     support for out-of-band buffers, where PEP 3118(1)-compatible data
     can be transmitted separately from the main pickle stream.

     Cambiato nella versione 3.0: The default protocol is 3.

     Cambiato nella versione 3.8: The default protocol is 4.

     Cambiato nella versione 3.14: The default protocol is 5.

The *note pickle: ab. module provides the following functions to make
the pickling process more convenient:

 -- Funzione: pickle.dump (obj, file, protocol=None, *,
          fix_imports=True, buffer_callback=None)

     Write the pickled representation of the object 'obj' to the open
     *note file object: 13cb. 'file'.  This is equivalent to
     ‘Pickler(file, protocol).dump(obj)’.

     Arguments 'file', 'protocol', 'fix_imports' and 'buffer_callback'
     have the same meaning as in the *note Pickler: c15. constructor.

     Cambiato nella versione 3.8: The 'buffer_callback' argument was
     added.

 -- Funzione: pickle.dumps (obj, protocol=None, *, fix_imports=True,
          buffer_callback=None)

     Return the pickled representation of the object 'obj' as a *note
     bytes: 192. object, instead of writing it to a file.

     Arguments 'protocol', 'fix_imports' and 'buffer_callback' have the
     same meaning as in the *note Pickler: c15. constructor.

     Cambiato nella versione 3.8: The 'buffer_callback' argument was
     added.

 -- Funzione: pickle.load (file, *, fix_imports=True, encoding='ASCII',
          errors='strict', buffers=None)

     Read the pickled representation of an object from the open *note
     file object: 13cb. 'file' and return the reconstituted object
     hierarchy specified therein.  This is equivalent to
     ‘Unpickler(file).load()’.

     The protocol version of the pickle is detected automatically, so no
     protocol argument is needed.  Bytes past the pickled representation
     of the object are ignored.

     Arguments 'file', 'fix_imports', 'encoding', 'errors', 'strict' and
     'buffers' have the same meaning as in the *note Unpickler: 175e.
     constructor.

     Cambiato nella versione 3.8: The 'buffers' argument was added.

 -- Funzione: pickle.loads (data, /, *, fix_imports=True,
          encoding='ASCII', errors='strict', buffers=None)

     Return the reconstituted object hierarchy of the pickled
     representation 'data' of an object.  'data' must be a *note
     bytes-like object: 193.

     The protocol version of the pickle is detected automatically, so no
     protocol argument is needed.  Bytes past the pickled representation
     of the object are ignored.

     Arguments 'fix_imports', 'encoding', 'errors', 'strict' and
     'buffers' have the same meaning as in the *note Unpickler: 175e.
     constructor.

     Cambiato nella versione 3.8: The 'buffers' argument was added.

The *note pickle: ab. module defines three exceptions:

 -- Eccezione: pickle.PickleError

     Common base class for the other pickling exceptions.  It inherits
     from *note Exception: bcf.

 -- Eccezione: pickle.PicklingError

     Error raised when an unpicklable object is encountered by *note
     Pickler: c15.  It inherits from *note PickleError: 2cf3.

     Refer to *note What can be pickled and unpickled?: 2cf4. to learn
     what kinds of objects can be pickled.

 -- Eccezione: pickle.UnpicklingError

     Error raised when there is a problem unpickling an object, such as
     a data corruption or a security violation.  It inherits from *note
     PickleError: 2cf3.

     Note that other exceptions may also be raised during unpickling,
     including (but not necessarily limited to) AttributeError,
     EOFError, ImportError, and IndexError.

The *note pickle: ab. module exports three classes, *note Pickler: c15,
*note Unpickler: 175e. and *note PickleBuffer: 1762.:

 -- Classe: pickle.Pickler (file, protocol=None, *, fix_imports=True,
          buffer_callback=None)

     This takes a binary file for writing a pickle data stream.

     The optional 'protocol' argument, an integer, tells the pickler to
     use the given protocol; supported protocols are 0 to *note
     HIGHEST_PROTOCOL: 16ac.  If not specified, the default is *note
     DEFAULT_PROTOCOL: a31.  If a negative number is specified, *note
     HIGHEST_PROTOCOL: 16ac. is selected.

     The 'file' argument must have a write() method that accepts a
     single bytes argument.  It can thus be an on-disk file opened for
     binary writing, an *note io.BytesIO: 10a6. instance, or any other
     custom object that meets this interface.

     If 'fix_imports' is true and 'protocol' is less than 3, pickle will
     try to map the new Python 3 names to the old module names used in
     Python 2, so that the pickle data stream is readable with Python 2.

     If 'buffer_callback' is ‘None’ (the default), buffer views are
     serialized into 'file' as part of the pickle stream.

     If 'buffer_callback' is not ‘None’, then it can be called any
     number of times with a buffer view.  If the callback returns a
     false value (such as ‘None’), the given buffer is *note
     out-of-band: 2cf6.; otherwise the buffer is serialized in-band,
     i.e.  inside the pickle stream.

     It is an error if 'buffer_callback' is not ‘None’ and 'protocol' is
     ‘None’ or smaller than 5.

     Cambiato nella versione 3.8: The 'buffer_callback' argument was
     added.

      -- Metodo: dump (obj)

          Write the pickled representation of 'obj' to the open file
          object given in the constructor.

      -- Metodo: persistent_id (obj)

          Do nothing by default.  This exists so a subclass can override
          it.

          If *note persistent_id(): 18f4. returns ‘None’, 'obj' is
          pickled as usual.  Any other value causes *note Pickler: c15.
          to emit the returned value as a persistent ID for 'obj'.  The
          meaning of this persistent ID should be defined by *note
          Unpickler.persistent_load(): 18fc.  Note that the value
          returned by *note persistent_id(): 18f4. cannot itself have a
          persistent ID.

          See *note Persistence of External Objects: 2cf7. for details
          and examples of uses.

          Cambiato nella versione 3.13: Add the default implementation
          of this method in the C implementation of ‘Pickler’.

      -- Attributo: dispatch_table

          A pickler object’s dispatch table is a registry of 'reduction
          functions' of the kind which can be declared using *note
          copyreg.pickle(): 2cf8.  It is a mapping whose keys are
          classes and whose values are reduction functions.  A reduction
          function takes a single argument of the associated class and
          should conform to the same interface as a *note __reduce__():
          bc8. method.

          By default, a pickler object will not have a *note
          dispatch_table: 132a. attribute, and it will instead use the
          global dispatch table managed by the *note copyreg: 2a.
          module.  However, to customize the pickling for a specific
          pickler object one can set the *note dispatch_table: 132a.
          attribute to a dict-like object.  Alternatively, if a subclass
          of *note Pickler: c15. has a *note dispatch_table: 132a.
          attribute then this will be used as the default dispatch table
          for instances of that class.

          See *note Dispatch Tables: 2cf9. for usage examples.

          Added in version 3.3.

      -- Metodo: reducer_override (obj)

          Special reducer that can be defined in *note Pickler: c15.
          subclasses.  This method has priority over any reducer in the
          *note dispatch_table: 132a.  It should conform to the same
          interface as a *note __reduce__(): bc8. method, and can
          optionally return *note NotImplemented: 1a2. to fallback on
          *note dispatch_table: 132a.-registered reducers to pickle
          ‘obj’.

          For a detailed example, see *note Custom Reduction for Types,
          Functions, and Other Objects: 2cfa.

          Added in version 3.8.

      -- Attributo: fast

          Deprecated.  Enable fast mode if set to a true value.  The
          fast mode disables the usage of memo, therefore speeding the
          pickling process by not generating superfluous PUT opcodes.
          It should not be used with self-referential objects, doing
          otherwise will cause *note Pickler: c15. to recurse
          infinitely.

          Use *note pickletools.optimize(): 2cfc. if you need more
          compact pickles.

      -- Metodo: clear_memo ()

          Clears the pickler’s «memo».

          The memo is the data structure that remembers which objects
          the pickler has already seen, so that shared or recursive
          objects are pickled by reference and not by value.  This
          method is useful when re-using picklers.

 -- Classe: pickle.Unpickler (file, *, fix_imports=True,
          encoding='ASCII', errors='strict', buffers=None)

     This takes a binary file for reading a pickle data stream.

     The protocol version of the pickle is detected automatically, so no
     protocol argument is needed.

     The argument 'file' must have three methods, a read() method that
     takes an integer argument, a readinto() method that takes a buffer
     argument and a readline() method that requires no arguments, as in
     the *note io.BufferedIOBase: 8a4. interface.  Thus 'file' can be an
     on-disk file opened for binary reading, an *note io.BytesIO: 10a6.
     object, or any other custom object that meets this interface.

     The optional arguments 'fix_imports', 'encoding' and 'errors' are
     used to control compatibility support for pickle stream generated
     by Python 2.  If 'fix_imports' is true, pickle will try to map the
     old Python 2 names to the new names used in Python 3.  The
     'encoding' and 'errors' tell pickle how to decode 8-bit string
     instances pickled by Python 2; these default to “ASCII” and
     “strict”, respectively.  The 'encoding' can be “bytes” to read
     these 8-bit string instances as bytes objects.  Using
     ‘encoding='latin1'’ is required for unpickling NumPy arrays and
     instances of *note datetime: 4e3, *note date: 1fa. and *note time:
     1fb. pickled by Python 2.

     If 'buffers' is ‘None’ (the default), then all data necessary for
     deserialization must be contained in the pickle stream.  This means
     that the 'buffer_callback' argument was ‘None’ when a *note
     Pickler: c15. was instantiated (or when *note dump(): 2cf2. or
     *note dumps(): 16ab. was called).

     If 'buffers' is not ‘None’, it should be an iterable of
     buffer-enabled objects that is consumed each time the pickle stream
     references an *note out-of-band: 2cf6. buffer view.  Such buffers
     have been given in order to the 'buffer_callback' of a Pickler
     object.

     Cambiato nella versione 3.8: The 'buffers' argument was added.

      -- Metodo: load ()

          Read the pickled representation of an object from the open
          file object given in the constructor, and return the
          reconstituted object hierarchy specified therein.  Bytes past
          the pickled representation of the object are ignored.

      -- Metodo: persistent_load (pid)

          Raise an *note UnpicklingError: 2cf5. by default.

          If defined, *note persistent_load(): 18fc. should return the
          object specified by the persistent ID 'pid'.  If an invalid
          persistent ID is encountered, an *note UnpicklingError: 2cf5.
          should be raised.

          See *note Persistence of External Objects: 2cf7. for details
          and examples of uses.

          Cambiato nella versione 3.13: Add the default implementation
          of this method in the C implementation of ‘Unpickler’.

      -- Metodo: find_class (module, name)

          Import 'module' if necessary and return the object called
          'name' from it, where the 'module' and 'name' arguments are
          *note str: 169. objects.  Note, unlike its name suggests,
          *note find_class(): 2cff. is also used for finding functions.

          Subclasses may override this to gain control over what type of
          objects and how they can be loaded, potentially reducing
          security risks.  Refer to *note Restricting Globals: 2d00. for
          details.

          Raises an *note auditing event: 1c56. ‘pickle.find_class’ with
          arguments ‘module’, ‘name’.

 -- Classe: pickle.PickleBuffer (buffer)

     A wrapper for a buffer representing picklable data.  'buffer' must
     be a *note buffer-providing: 260. object, such as a *note
     bytes-like object: 193. or a N-dimensional array.

     *note PickleBuffer: 1762. is itself a buffer provider, therefore it
     is possible to pass it to other APIs expecting a buffer-providing
     object, such as *note memoryview: 165.

     *note PickleBuffer: 1762. objects can only be serialized using
     pickle protocol 5 or higher.  They are eligible for *note
     out-of-band serialization: 2cf6.

     Added in version 3.8.

      -- Metodo: raw ()

          Return a *note memoryview: 165. of the memory area underlying
          this buffer.  The returned object is a one-dimensional,
          C-contiguous memoryview with format ‘B’ (unsigned bytes).
          *note BufferError: 177f. is raised if the buffer is neither C-
          nor Fortran-contiguous.

      -- Metodo: release ()

          Release the underlying buffer exposed by the PickleBuffer
          object.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3118/


File: python.info,  Node: What can be pickled and unpickled?,  Next: Pickling Class Instances,  Prev: Module Interface,  Up: pickle — Python object serialization

5.12.1.6 What can be pickled and unpickled?
...........................................

The following types can be pickled:

   * built-in constants (‘None’, ‘True’, ‘False’, ‘Ellipsis’, and *note
     NotImplemented: 1a2.);

   * integers, floating-point numbers, complex numbers;

   * strings, bytes, bytearrays;

   * tuples, lists, sets, and dictionaries containing only picklable
     objects;

   * functions (built-in and user-defined) accessible from the top level
     of a module (using *note def: 1661, not *note lambda: 14a5.);

   * classes accessible from the top level of a module;

   * instances of such classes whose the result of calling *note
     __getstate__(): 7f2. is picklable (see section *note Pickling Class
     Instances: 2ced. for details).

Attempts to pickle unpicklable objects will raise the *note
PicklingError: 192a. exception; when this happens, an unspecified number
of bytes may have already been written to the underlying file.  Trying
to pickle a highly recursive data structure may exceed the maximum
recursion depth, a *note RecursionError: f6a. will be raised in this
case.  You can carefully raise this limit with *note
sys.setrecursionlimit(): 6eb.

Note that functions (built-in and user-defined) are pickled by fully
*note qualified name: 1d0c, not by value.  (1)  This means that only the
function name is pickled, along with the name of the containing module
and classes.  Neither the function’s code, nor any of its function
attributes are pickled.  Thus the defining module must be importable in
the unpickling environment, and the module must contain the named
object, otherwise an exception will be raised.  (2)

Similarly, classes are pickled by fully qualified name, so the same
restrictions in the unpickling environment apply.  Note that none of the
class’s code or data is pickled, so in the following example the class
attribute ‘attr’ is not restored in the unpickling environment:

     class Foo:
         attr = 'A class attribute'

     picklestring = pickle.dumps(Foo)

These restrictions are why picklable functions and classes must be
defined at the top level of a module.

Similarly, when class instances are pickled, their class’s code and data
are not pickled along with them.  Only the instance data are pickled.
This is done on purpose, so you can fix bugs in a class or add methods
to the class and still load objects that were created with an earlier
version of the class.  If you plan to have long-lived objects that will
see many versions of a class, it may be worthwhile to put a version
number in the objects so that suitable conversions can be made by the
class’s *note __setstate__(): bc9. method.

   ---------- Footnotes ----------

   (1) This is why *note lambda: 14a5. functions cannot be pickled: all
‘lambda’ functions share the same name: ‘<lambda>’.

   (2) The exception raised will likely be an *note ImportError: 65b. or
an *note AttributeError: 5f0. but it could be something else.


File: python.info,  Node: Pickling Class Instances,  Next: Custom Reduction for Types Functions and Other Objects,  Prev: What can be pickled and unpickled?,  Up: pickle — Python object serialization

5.12.1.7 Pickling Class Instances
.................................

In this section, we describe the general mechanisms available to you to
define, customize, and control how class instances are pickled and
unpickled.

In most cases, no additional code is needed to make instances picklable.
By default, pickle will retrieve the class and the attributes of an
instance via introspection.  When a class instance is unpickled, its
*note __init__(): 8c0. method is usually 'not' invoked.  The default
behaviour first creates an uninitialized instance and then restores the
saved attributes.  The following code shows an implementation of this
behaviour:

     def save(obj):
         return (obj.__class__, obj.__dict__)

     def restore(cls, attributes):
         obj = cls.__new__(cls)
         obj.__dict__.update(attributes)
         return obj

Classes can alter the default behaviour by providing one or several
special methods:

 -- Metodo: object.__getnewargs_ex__ ()

     In protocols 2 and newer, classes that implements the *note
     __getnewargs_ex__(): 2d05. method can dictate the values passed to
     the *note __new__(): 7a1. method upon unpickling.  The method must
     return a pair ‘(args, kwargs)’ where 'args' is a tuple of
     positional arguments and 'kwargs' a dictionary of named arguments
     for constructing the object.  Those will be passed to the *note
     __new__(): 7a1. method upon unpickling.

     You should implement this method if the *note __new__(): 7a1.
     method of your class requires keyword-only arguments.  Otherwise,
     it is recommended for compatibility to implement *note
     __getnewargs__(): fd6.

     Cambiato nella versione 3.6: *note __getnewargs_ex__(): 2d05. is
     now used in protocols 2 and 3.

 -- Metodo: object.__getnewargs__ ()

     This method serves a similar purpose as *note __getnewargs_ex__():
     2d05, but supports only positional arguments.  It must return a
     tuple of arguments ‘args’ which will be passed to the *note
     __new__(): 7a1. method upon unpickling.

     *note __getnewargs__(): fd6. will not be called if *note
     __getnewargs_ex__(): 2d05. is defined.

     Cambiato nella versione 3.6: Before Python 3.6, *note
     __getnewargs__(): fd6. was called instead of *note
     __getnewargs_ex__(): 2d05. in protocols 2 and 3.

 -- Metodo: object.__getstate__ ()

     Classes can further influence how their instances are pickled by
     overriding the method *note __getstate__(): 7f2.  It is called and
     the returned object is pickled as the contents for the instance,
     instead of a default state.  There are several cases:

        * For a class that has no instance *note __dict__: 77e. and no
          *note __slots__: 16f2, the default state is ‘None’.

        * For a class that has an instance *note __dict__: 77e. and no
          *note __slots__: 16f2, the default state is ‘self.__dict__’.

        * For a class that has an instance *note __dict__: 77e. and
          *note __slots__: 16f2, the default state is a tuple consisting
          of two dictionaries: ‘self.__dict__’, and a dictionary mapping
          slot names to slot values.  Only slots that have a value are
          included in the latter.

        * For a class that has *note __slots__: 16f2. and no instance
          *note __dict__: 77e, the default state is a tuple whose first
          item is ‘None’ and whose second item is a dictionary mapping
          slot names to slot values described in the previous bullet.

     Cambiato nella versione 3.11: Added the default implementation of
     the ‘__getstate__()’ method in the *note object: c80. class.

 -- Metodo: object.__setstate__ (state)

     Upon unpickling, if the class defines *note __setstate__(): bc9, it
     is called with the unpickled state.  In that case, there is no
     requirement for the state object to be a dictionary.  Otherwise,
     the pickled state must be a dictionary and its items are assigned
     to the new instance’s dictionary.

          Nota: If *note __reduce__(): bc8. returns a state with value
          ‘None’ at pickling, the *note __setstate__(): bc9. method will
          not be called upon unpickling.

Refer to the section *note Handling Stateful Objects: 2d06. for more
information about how to use the methods *note __getstate__(): 7f2. and
*note __setstate__(): bc9.

     Nota: At unpickling time, some methods like *note __getattr__():
     6fb, *note __getattribute__(): dcd, or *note __setattr__(): 2362.
     may be called upon the instance.  In case those methods rely on
     some internal invariant being true, the type should implement *note
     __new__(): 7a1. to establish such an invariant, as *note
     __init__(): 8c0. is not called when unpickling an instance.

As we shall see, pickle does not use directly the methods described
above.  In fact, these methods are part of the copy protocol which
implements the *note __reduce__(): bc8. special method.  The copy
protocol provides a unified interface for retrieving the data necessary
for pickling and copying objects.  (1)

Although powerful, implementing *note __reduce__(): bc8. directly in
your classes is error prone.  For this reason, class designers should
use the high-level interface (i.e., *note __getnewargs_ex__(): 2d05,
*note __getstate__(): 7f2. and *note __setstate__(): bc9.) whenever
possible.  We will show, however, cases where using ‘__reduce__()’ is
the only option or leads to more efficient pickling or both.

 -- Metodo: object.__reduce__ ()

     The interface is currently defined as follows.  The *note
     __reduce__(): bc8. method takes no argument and shall return either
     a string or preferably a tuple (the returned object is often
     referred to as the «reduce value»).

     If a string is returned, the string should be interpreted as the
     name of a global variable.  It should be the object’s local name
     relative to its module; the pickle module searches the module
     namespace to determine the object’s module.  This behaviour is
     typically useful for singletons.

     When a tuple is returned, it must be between two and six items
     long.  Optional items can either be omitted, or ‘None’ can be
     provided as their value.  The semantics of each item are in order:

        * A callable object that will be called to create the initial
          version of the object.

        * A tuple of arguments for the callable object.  An empty tuple
          must be given if the callable does not accept any argument.

        * Optionally, the object’s state, which will be passed to the
          object’s *note __setstate__(): bc9. method as previously
          described.  If the object has no such method then, the value
          must be a dictionary and it will be added to the object’s
          *note __dict__: 77e. attribute.

        * Optionally, an iterator (and not a sequence) yielding
          successive items.  These items will be appended to the object
          either using ‘obj.append(item)’ or, in batch, using
          ‘obj.extend(list_of_items)’.  This is primarily used for list
          subclasses, but may be used by other classes as long as they
          have *note append(): 23bc. and *note extend(): 23bf. methods
          with the appropriate signature.  (Whether ‘append()’ or
          ‘extend()’ is used depends on which pickle protocol version is
          used as well as the number of items to append, so both must be
          supported.)

        * Optionally, an iterator (not a sequence) yielding successive
          key-value pairs.  These items will be stored to the object
          using ‘obj[key] = value’.  This is primarily used for
          dictionary subclasses, but may be used by other classes as
          long as they implement *note __setitem__(): 14d3.

        * Optionally, a callable with a ‘(obj, state)’ signature.  This
          callable allows the user to programmatically control the
          state-updating behavior of a specific object, instead of using
          ‘obj’’s static *note __setstate__(): bc9. method.  If not
          ‘None’, this callable will have priority over ‘obj’’s *note
          __setstate__(): bc9.

          Added in version 3.8: The optional sixth tuple item, ‘(obj,
          state)’, was added.

 -- Metodo: object.__reduce_ex__ (protocol)

     Alternatively, a *note __reduce_ex__(): 1953. method may be
     defined.  The only difference is this method should take a single
     integer argument, the protocol version.  When defined, pickle will
     prefer it over the *note __reduce__(): bc8. method.  In addition,
     *note __reduce__(): bc8. automatically becomes a synonym for the
     extended version.  The main use for this method is to provide
     backwards-compatible reduce values for older Python releases.

* Menu:

* Persistence of External Objects::
* Dispatch Tables::
* Handling Stateful Objects::

   ---------- Footnotes ----------

   (1) The *note copy: 29. module uses this protocol for shallow and
deep copying operations.


File: python.info,  Node: Persistence of External Objects,  Next: Dispatch Tables,  Up: Pickling Class Instances

5.12.1.8 Persistence of External Objects
........................................

For the benefit of object persistence, the *note pickle: ab. module
supports the notion of a reference to an object outside the pickled data
stream.  Such objects are referenced by a persistent ID, which should be
either a string of alphanumeric characters (for protocol 0) (1) or just
an arbitrary object (for any newer protocol).

The resolution of such persistent IDs is not defined by the *note
pickle: ab. module; it will delegate this resolution to the user-defined
methods on the pickler and unpickler, *note persistent_id(): 18f4. and
*note persistent_load(): 18fc. respectively.

To pickle objects that have an external persistent ID, the pickler must
have a custom *note persistent_id(): 18f4. method that takes an object
as an argument and returns either ‘None’ or the persistent ID for that
object.  When ‘None’ is returned, the pickler simply pickles the object
as normal.  When a persistent ID string is returned, the pickler will
pickle that object, along with a marker so that the unpickler will
recognize it as a persistent ID.

To unpickle external objects, the unpickler must have a custom *note
persistent_load(): 18fc. method that takes a persistent ID object and
returns the referenced object.

Here is a comprehensive example presenting how persistent ID can be used
to pickle external objects by reference.

     # Simple example presenting how persistent ID can be used to pickle
     # external objects by reference.

     import pickle
     import sqlite3
     from collections import namedtuple

     # Simple class representing a record in our database.
     MemoRecord = namedtuple("MemoRecord", "key, task")

     class DBPickler(pickle.Pickler):

         def persistent_id(self, obj):
             # Instead of pickling MemoRecord as a regular class instance, we emit a
             # persistent ID.
             if isinstance(obj, MemoRecord):
                 # Here, our persistent ID is simply a tuple, containing a tag and a
                 # key, which refers to a specific record in the database.
                 return ("MemoRecord", obj.key)
             else:
                 # If obj does not have a persistent ID, return None. This means obj
                 # needs to be pickled as usual.
                 return None


     class DBUnpickler(pickle.Unpickler):

         def __init__(self, file, connection):
             super().__init__(file)
             self.connection = connection

         def persistent_load(self, pid):
             # This method is invoked whenever a persistent ID is encountered.
             # Here, pid is the tuple returned by DBPickler.
             cursor = self.connection.cursor()
             type_tag, key_id = pid
             if type_tag == "MemoRecord":
                 # Fetch the referenced record from the database and return it.
                 cursor.execute("SELECT * FROM memos WHERE key=?", (str(key_id),))
                 key, task = cursor.fetchone()
                 return MemoRecord(key, task)
             else:
                 # Always raises an error if you cannot return the correct object.
                 # Otherwise, the unpickler will think None is the object referenced
                 # by the persistent ID.
                 raise pickle.UnpicklingError("unsupported persistent object")


     def main():
         import io
         import pprint

         # Initialize and populate our database.
         conn = sqlite3.connect(":memory:")
         cursor = conn.cursor()
         cursor.execute("CREATE TABLE memos(key INTEGER PRIMARY KEY, task TEXT)")
         tasks = (
             'give food to fish',
             'prepare group meeting',
             'fight with a zebra',
             )
         for task in tasks:
             cursor.execute("INSERT INTO memos VALUES(NULL, ?)", (task,))

         # Fetch the records to be pickled.
         cursor.execute("SELECT * FROM memos")
         memos = [MemoRecord(key, task) for key, task in cursor]
         # Save the records using our custom DBPickler.
         file = io.BytesIO()
         DBPickler(file).dump(memos)

         print("Pickled records:")
         pprint.pprint(memos)

         # Update a record, just for good measure.
         cursor.execute("UPDATE memos SET task='learn italian' WHERE key=1")

         # Load the records from the pickle data stream.
         file.seek(0)
         memos = DBUnpickler(file, conn).load()

         print("Unpickled records:")
         pprint.pprint(memos)


     if __name__ == '__main__':
         main()

   ---------- Footnotes ----------

   (1) The limitation on alphanumeric characters is due to the fact that
persistent IDs in protocol 0 are delimited by the newline character.
Therefore if any kind of newline characters occurs in persistent IDs,
the resulting pickled data will become unreadable.


File: python.info,  Node: Dispatch Tables,  Next: Handling Stateful Objects,  Prev: Persistence of External Objects,  Up: Pickling Class Instances

5.12.1.9 Dispatch Tables
........................

If one wants to customize pickling of some classes without disturbing
any other code which depends on pickling, then one can create a pickler
with a private dispatch table.

The global dispatch table managed by the *note copyreg: 2a. module is
available as ‘copyreg.dispatch_table’.  Therefore, one may choose to use
a modified copy of ‘copyreg.dispatch_table’ as a private dispatch table.

For example

     f = io.BytesIO()
     p = pickle.Pickler(f)
     p.dispatch_table = copyreg.dispatch_table.copy()
     p.dispatch_table[SomeClass] = reduce_SomeClass

creates an instance of *note pickle.Pickler: c15. with a private
dispatch table which handles the ‘SomeClass’ class specially.
Alternatively, the code

     class MyPickler(pickle.Pickler):
         dispatch_table = copyreg.dispatch_table.copy()
         dispatch_table[SomeClass] = reduce_SomeClass
     f = io.BytesIO()
     p = MyPickler(f)

does the same but all instances of ‘MyPickler’ will by default share the
private dispatch table.  On the other hand, the code

     copyreg.pickle(SomeClass, reduce_SomeClass)
     f = io.BytesIO()
     p = pickle.Pickler(f)

modifies the global dispatch table shared by all users of the *note
copyreg: 2a. module.


File: python.info,  Node: Handling Stateful Objects,  Prev: Dispatch Tables,  Up: Pickling Class Instances

5.12.1.10 Handling Stateful Objects
...................................

Here’s an example that shows how to modify pickling behavior for a
class.  The ‘TextReader’ class below opens a text file, and returns the
line number and line contents each time its ‘readline()’ method is
called.  If a ‘TextReader’ instance is pickled, all attributes 'except'
the file object member are saved.  When the instance is unpickled, the
file is reopened, and reading resumes from the last location.  The
‘__setstate__()’ and ‘__getstate__()’ methods are used to implement this
behavior.

     class TextReader:
         """Print and number lines in a text file."""

         def __init__(self, filename):
             self.filename = filename
             self.file = open(filename)
             self.lineno = 0

         def readline(self):
             self.lineno += 1
             line = self.file.readline()
             if not line:
                 return None
             if line.endswith('\n'):
                 line = line[:-1]
             return "%i: %s" % (self.lineno, line)

         def __getstate__(self):
             # Copy the object's state from self.__dict__ which contains
             # all our instance attributes. Always use the dict.copy()
             # method to avoid modifying the original state.
             state = self.__dict__.copy()
             # Remove the unpicklable entries.
             del state['file']
             return state

         def __setstate__(self, state):
             # Restore instance attributes (i.e., filename and lineno).
             self.__dict__.update(state)
             # Restore the previously opened file's state. To do so, we need to
             # reopen it and read from it until the line count is restored.
             file = open(self.filename)
             for _ in range(self.lineno):
                 file.readline()
             # Finally, save the file.
             self.file = file

A sample usage might be something like this:

     >>> reader = TextReader("hello.txt")
     >>> reader.readline()
     '1: Hello world!'
     >>> reader.readline()
     '2: I am line number two.'
     >>> new_reader = pickle.loads(pickle.dumps(reader))
     >>> new_reader.readline()
     '3: Goodbye!'


File: python.info,  Node: Custom Reduction for Types Functions and Other Objects,  Next: Out-of-band Buffers,  Prev: Pickling Class Instances,  Up: pickle — Python object serialization

5.12.1.11 Custom Reduction for Types, Functions, and Other Objects
..................................................................

Added in version 3.8.

Sometimes, *note dispatch_table: 132a. may not be flexible enough.  In
particular we may want to customize pickling based on another criterion
than the object’s type, or we may want to customize the pickling of
functions and classes.

For those cases, it is possible to subclass from the *note Pickler: c15.
class and implement a *note reducer_override(): c16. method.  This
method can return an arbitrary reduction tuple (see *note __reduce__():
bc8.).  It can alternatively return *note NotImplemented: 1a2. to
fallback to the traditional behavior.

If both the *note dispatch_table: 132a. and *note reducer_override():
c16. are defined, then *note reducer_override(): c16. method takes
priority.

     Nota: For performance reasons, *note reducer_override(): c16. may
     not be called for the following objects: ‘None’, ‘True’, ‘False’,
     and exact instances of *note int: 19b, *note float: 196, *note
     bytes: 192, *note str: 169, *note dict: 183, *note set: 184, *note
     frozenset: 7f3, *note list: 24d. and *note tuple: 614.

Here is a simple example where we allow pickling and reconstructing a
given class:

     import io
     import pickle

     class MyClass:
         my_attribute = 1

     class MyPickler(pickle.Pickler):
         def reducer_override(self, obj):
             """Custom reducer for MyClass."""
             if getattr(obj, "__name__", None) == "MyClass":
                 return type, (obj.__name__, obj.__bases__,
                               {'my_attribute': obj.my_attribute})
             else:
                 # For any other object, fallback to usual reduction
                 return NotImplemented

     f = io.BytesIO()
     p = MyPickler(f)
     p.dump(MyClass)

     del MyClass

     unpickled_class = pickle.loads(f.getvalue())

     assert isinstance(unpickled_class, type)
     assert unpickled_class.__name__ == "MyClass"
     assert unpickled_class.my_attribute == 1


File: python.info,  Node: Out-of-band Buffers,  Next: Restricting Globals,  Prev: Custom Reduction for Types Functions and Other Objects,  Up: pickle — Python object serialization

5.12.1.12 Out-of-band Buffers
.............................

Added in version 3.8.

In some contexts, the *note pickle: ab. module is used to transfer
massive amounts of data.  Therefore, it can be important to minimize the
number of memory copies, to preserve performance and resource
consumption.  However, normal operation of the *note pickle: ab. module,
as it transforms a graph-like structure of objects into a sequential
stream of bytes, intrinsically involves copying data to and from the
pickle stream.

This constraint can be eschewed if both the 'provider' (the
implementation of the object types to be transferred) and the 'consumer'
(the implementation of the communications system) support the
out-of-band transfer facilities provided by pickle protocol 5 and
higher.

* Menu:

* Provider API::
* Consumer API::
* Example: Example<4>.


File: python.info,  Node: Provider API,  Next: Consumer API,  Up: Out-of-band Buffers

5.12.1.13 Provider API
......................

The large data objects to be pickled must implement a *note
__reduce_ex__(): 1953. method specialized for protocol 5 and higher,
which returns a *note PickleBuffer: 1762. instance (instead of e.g.  a
*note bytes: 192. object) for any large data.

A *note PickleBuffer: 1762. object 'signals' that the underlying buffer
is eligible for out-of-band data transfer.  Those objects remain
compatible with normal usage of the *note pickle: ab. module.  However,
consumers can also opt-in to tell *note pickle: ab. that they will
handle those buffers by themselves.


File: python.info,  Node: Consumer API,  Next: Example<4>,  Prev: Provider API,  Up: Out-of-band Buffers

5.12.1.14 Consumer API
......................

A communications system can enable custom handling of the *note
PickleBuffer: 1762. objects generated when serializing an object graph.

On the sending side, it needs to pass a 'buffer_callback' argument to
*note Pickler: c15. (or to the *note dump(): 2cf2. or *note dumps():
16ab. function), which will be called with each *note PickleBuffer:
1762. generated while pickling the object graph.  Buffers accumulated by
the 'buffer_callback' will not see their data copied into the pickle
stream, only a cheap marker will be inserted.

On the receiving side, it needs to pass a 'buffers' argument to *note
Unpickler: 175e. (or to the *note load(): f0e. or *note loads(): f0f.
function), which is an iterable of the buffers which were passed to
'buffer_callback'.  That iterable should produce buffers in the same
order as they were passed to 'buffer_callback'.  Those buffers will
provide the data expected by the reconstructors of the objects whose
pickling produced the original *note PickleBuffer: 1762. objects.

Between the sending side and the receiving side, the communications
system is free to implement its own transfer mechanism for out-of-band
buffers.  Potential optimizations include the use of shared memory or
datatype-dependent compression.


File: python.info,  Node: Example<4>,  Prev: Consumer API,  Up: Out-of-band Buffers

5.12.1.15 Example
.................

Here is a trivial example where we implement a *note bytearray: 344.
subclass able to participate in out-of-band buffer pickling:

     class ZeroCopyByteArray(bytearray):

         def __reduce_ex__(self, protocol):
             if protocol >= 5:
                 return type(self)._reconstruct, (PickleBuffer(self),), None
             else:
                 # PickleBuffer is forbidden with pickle protocols <= 4.
                 return type(self)._reconstruct, (bytearray(self),)

         @classmethod
         def _reconstruct(cls, obj):
             with memoryview(obj) as m:
                 # Get a handle over the original buffer object
                 obj = m.obj
                 if type(obj) is cls:
                     # Original buffer object is a ZeroCopyByteArray, return it
                     # as-is.
                     return obj
                 else:
                     return cls(obj)

The reconstructor (the ‘_reconstruct’ class method) returns the buffer’s
providing object if it has the right type.  This is an easy way to
simulate zero-copy behaviour on this toy example.

On the consumer side, we can pickle those objects the usual way, which
when unserialized will give us a copy of the original object:

     b = ZeroCopyByteArray(b"abc")
     data = pickle.dumps(b, protocol=5)
     new_b = pickle.loads(data)
     print(b == new_b)  # True
     print(b is new_b)  # False: a copy was made

But if we pass a 'buffer_callback' and then give back the accumulated
buffers when unserializing, we are able to get back the original object:

     b = ZeroCopyByteArray(b"abc")
     buffers = []
     data = pickle.dumps(b, protocol=5, buffer_callback=buffers.append)
     new_b = pickle.loads(data, buffers=buffers)
     print(b == new_b)  # True
     print(b is new_b)  # True: no copy was made

This example is limited by the fact that *note bytearray: 344. allocates
its own memory: you cannot create a *note bytearray: 344. instance that
is backed by another object’s memory.  However, third-party datatypes
such as NumPy arrays do not have this limitation, and allow use of
zero-copy pickling (or making as few copies as possible) when
transferring between distinct processes or systems.

Vedi anche
..........

PEP 574(1) – Pickle protocol 5 with out-of-band data

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0574/


File: python.info,  Node: Restricting Globals,  Next: Performance<2>,  Prev: Out-of-band Buffers,  Up: pickle — Python object serialization

5.12.1.16 Restricting Globals
.............................

By default, unpickling will import any class or function that it finds
in the pickle data.  For many applications, this behaviour is
unacceptable as it permits the unpickler to import and invoke arbitrary
code.  Just consider what this hand-crafted pickle data stream does when
loaded:

     >>> import pickle
     >>> pickle.loads(b"cos\nsystem\n(S'echo hello world'\ntR.")
     hello world
     0

In this example, the unpickler imports the *note os.system(): 1664.
function and then apply the string argument «echo hello world».
Although this example is inoffensive, it is not difficult to imagine one
that could damage your system.

For this reason, you may want to control what gets unpickled by
customizing *note Unpickler.find_class(): 2cff.  Unlike its name
suggests, *note Unpickler.find_class(): 2cff. is called whenever a
global (i.e., a class or a function) is requested.  Thus it is possible
to either completely forbid globals or restrict them to a safe subset.

Here is an example of an unpickler allowing only few safe classes from
the *note builtins: 13. module to be loaded:

     import builtins
     import io
     import pickle

     safe_builtins = {
         'range',
         'complex',
         'set',
         'frozenset',
         'slice',
     }

     class RestrictedUnpickler(pickle.Unpickler):

         def find_class(self, module, name):
             # Only allow safe classes from builtins.
             if module == "builtins" and name in safe_builtins:
                 return getattr(builtins, name)
             # Forbid everything else.
             raise pickle.UnpicklingError("global '%s.%s' is forbidden" %
                                          (module, name))

     def restricted_loads(s):
         """Helper function analogous to pickle.loads()."""
         return RestrictedUnpickler(io.BytesIO(s)).load()

A sample usage of our unpickler working as intended:

     >>> restricted_loads(pickle.dumps([1, 2, range(15)]))
     [1, 2, range(0, 15)]
     >>> restricted_loads(b"cos\nsystem\n(S'echo hello world'\ntR.")
     Traceback (most recent call last):
       ...
     pickle.UnpicklingError: global 'os.system' is forbidden
     >>> restricted_loads(b'cbuiltins\neval\n'
     ...                  b'(S\'getattr(__import__("os"), "system")'
     ...                  b'("echo hello world")\'\ntR.')
     Traceback (most recent call last):
       ...
     pickle.UnpicklingError: global 'builtins.eval' is forbidden

As our examples shows, you have to be careful with what you allow to be
unpickled.  Therefore if security is a concern, you may want to consider
alternatives such as the marshalling API in *note xmlrpc.client: 134. or
third-party solutions.


File: python.info,  Node: Performance<2>,  Next: Examples<7>,  Prev: Restricting Globals,  Up: pickle — Python object serialization

5.12.1.17 Performance
.....................

Recent versions of the pickle protocol (from protocol 2 and upwards)
feature efficient binary encodings for several common features and
built-in types.  Also, the *note pickle: ab. module has a transparent
optimizer written in C.


File: python.info,  Node: Examples<7>,  Next: Command-line interface,  Prev: Performance<2>,  Up: pickle — Python object serialization

5.12.1.18 Examples
..................

For the simplest code, use the *note dump(): 2cf2. and *note load():
f0e. functions.

     import pickle

     # An arbitrary collection of objects supported by pickle.
     data = {
         'a': [1, 2.0, 3+4j],
         'b': ("character string", b"byte string"),
         'c': {None, True, False}
     }

     with open('data.pickle', 'wb') as f:
         # Pickle the 'data' dictionary using the highest protocol available.
         pickle.dump(data, f, pickle.HIGHEST_PROTOCOL)

The following example reads the resulting pickled data.

     import pickle

     with open('data.pickle', 'rb') as f:
         # The protocol version used is detected automatically, so we do not
         # have to specify it.
         data = pickle.load(f)


File: python.info,  Node: Command-line interface,  Prev: Examples<7>,  Up: pickle — Python object serialization

5.12.1.19 Command-line interface
................................

The *note pickle: ab. module can be invoked as a script from the command
line, it will display contents of the pickle files.  However, when the
pickle file that you want to examine comes from an untrusted source, ‘-m
pickletools’ is a safer option because it does not execute pickle
bytecode, see *note pickletools CLI usage: 2d15.

     python -m pickle pickle_file [pickle_file ...]

The following option is accepted:

 -- Option: pickle_file

     A pickle file to read, or ‘-’ to indicate reading from standard
     input.

Vedi anche
..........

Module *note copyreg: 2a.

     Pickle interface constructor registration for extension types.

Module *note pickletools: ac.

     Tools for working with and analyzing pickled data.

Module *note shelve: c8.

     Indexed databases of objects; uses *note pickle: ab.

Module *note copy: 29.

     Shallow and deep object copying.

Module *note marshal: 91.

     High-performance serialization of built-in types.


File: python.info,  Node: copyreg — Register pickle support functions,  Next: shelve — Python object persistence,  Prev: pickle — Python object serialization,  Up: Data Persistence

5.12.2 ‘copyreg’ — Register ‘pickle’ support functions
------------------------------------------------------

'Source code:' Lib/copyreg.py(1)

__________________________________________________________________

The *note copyreg: 2a. module offers a way to define functions used
while pickling specific objects.  The *note pickle: ab. and *note copy:
29. modules use those functions when pickling/copying those objects.
The module provides configuration information about object constructors
which are not classes.  Such constructors may be factory functions or
class instances.

 -- Funzione: copyreg.constructor (object)

     Declares 'object' to be a valid constructor.  If 'object' is not
     callable (and hence not valid as a constructor), raises *note
     TypeError: 198.

 -- Funzione: copyreg.pickle (type, function, constructor_ob=None)

     Declares that 'function' should be used as a «reduction» function
     for objects of type 'type'.  'function' must return either a string
     or a tuple containing between two and six elements.  See the *note
     dispatch_table: 132a. for more details on the interface of
     'function'.

     The 'constructor_ob' parameter is a legacy feature and is now
     ignored, but if passed it must be a callable.

     Note that the *note dispatch_table: 132a. attribute of a pickler
     object or subclass of *note pickle.Pickler: c15. can also be used
     for declaring reduction functions.

* Menu:

* Example: Example<5>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/copyreg.py


File: python.info,  Node: Example<5>,  Up: copyreg — Register pickle support functions

5.12.2.1 Example
................

The example below would like to show how to register a pickle function
and how it will be used:

     >>> import copyreg, copy, pickle
     >>> class C:
     ...     def __init__(self, a):
     ...         self.a = a
     ...
     >>> def pickle_c(c):
     ...     print("pickling a C instance...")
     ...     return C, (c.a,)
     ...
     >>> copyreg.pickle(C, pickle_c)
     >>> c = C(1)
     >>> d = copy.copy(c)
     pickling a C instance...
     >>> p = pickle.dumps(c)
     pickling a C instance...


File: python.info,  Node: shelve — Python object persistence,  Next: marshal — Internal Python object serialization,  Prev: copyreg — Register pickle support functions,  Up: Data Persistence

5.12.3 ‘shelve’ — Python object persistence
-------------------------------------------

'Source code:' Lib/shelve.py(1)

__________________________________________________________________

A «shelf» is a persistent, dictionary-like object.  The difference with
«dbm» databases is that the values (not the keys!)  in a shelf can be
essentially arbitrary Python objects — anything that the *note pickle:
ab. module can handle.  This includes most class instances, recursive
data types, and objects containing lots of shared sub-objects.  The keys
are ordinary strings.

 -- Funzione: shelve.open (filename, flag='c', protocol=None,
          writeback=False)

     Open a persistent dictionary.  The filename specified is the base
     filename for the underlying database.  As a side-effect, an
     extension may be added to the filename and more than one file may
     be created.  By default, the underlying database file is opened for
     reading and writing.  The optional 'flag' parameter has the same
     interpretation as the 'flag' parameter of *note dbm.open(): 112e.

     By default, pickles created with *note pickle.DEFAULT_PROTOCOL:
     a31. are used to serialize values.  The version of the pickle
     protocol can be specified with the 'protocol' parameter.

     Because of Python semantics, a shelf cannot know when a mutable
     persistent-dictionary entry is modified.  By default modified
     objects are written 'only' when assigned to the shelf (see *note
     Example: 2d1f.).  If the optional 'writeback' parameter is set to
     ‘True’, all entries accessed are also cached in memory, and written
     back on *note sync(): 2d20. and *note close(): 2d21.; this can make
     it handier to mutate mutable entries in the persistent dictionary,
     but, if many entries are accessed, it can consume vast amounts of
     memory for the cache, and it can make the close operation very slow
     since all accessed entries are written back (there is no way to
     determine which accessed entries are mutable, nor which ones were
     actually mutated).

     Cambiato nella versione 3.10: *note pickle.DEFAULT_PROTOCOL: a31.
     is now used as the default pickle protocol.

     Cambiato nella versione 3.11: Accepts *note path-like object: 5a1.
     for filename.

          Nota: Do not rely on the shelf being closed automatically;
          always call *note close(): 2d21. explicitly when you don’t
          need it any more, or use *note shelve.open(): 1a59. as a
          context manager:

               with shelve.open('spam') as db:
                   db['eggs'] = 'eggs'
     Avvertimento: Because the *note shelve: c8. module is backed by
     *note pickle: ab, it is insecure to load a shelf from an untrusted
     source.  Like with pickle, loading a shelf can execute arbitrary
     code.

Shelf objects support most of methods and operations supported by
dictionaries (except copying, constructors and operators ‘|’ and ‘|=’).
This eases the transition from dictionary based scripts to those
requiring persistent storage.

Two additional methods are supported:

 -- Metodo: Shelf.sync ()

     Write back all entries in the cache if the shelf was opened with
     'writeback' set to *note True: e09.  Also empty the cache and
     synchronize the persistent dictionary on disk, if feasible.  This
     is called automatically when the shelf is closed with *note
     close(): 2d21.

 -- Metodo: Shelf.close ()

     Synchronize and close the persistent 'dict' object.  Operations on
     a closed shelf will fail with a *note ValueError: 2ec.

Vedi anche
..........

Persistent dictionary recipe(2) with widely supported storage formats
and having the speed of native dictionaries.

* Menu:

* Restrictions::
* Example: Example<6>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/shelve.py

   (2) 
https://code.activestate.com/recipes/576642-persistent-dict-with-multiple-standard-file-format/


File: python.info,  Node: Restrictions,  Next: Example<6>,  Up: shelve — Python object persistence

5.12.3.1 Restrictions
.....................

   * The choice of which database package will be used (such as *note
     dbm.ndbm: 38. or *note dbm.gnu: 37.) depends on which interface is
     available.  Therefore it is not safe to open the database directly
     using *note dbm: 35.  The database is also (unfortunately) subject
     to the limitations of *note dbm: 35, if it is used — this means
     that (the pickled representation of) the objects stored in the
     database should be fairly small, and in rare cases key collisions
     may cause the database to refuse updates.

   * The *note shelve: c8. module does not support 'concurrent'
     read/write access to shelved objects.  (Multiple simultaneous read
     accesses are safe.)  When a program has a shelf open for writing,
     no other program should have it open for reading or writing.  Unix
     file locking can be used to solve this, but this differs across
     Unix versions and requires knowledge about the database
     implementation used.

   * On macOS *note dbm.ndbm: 38. can silently corrupt the database file
     on updates, which can cause hard crashes when trying to read from
     the database.

 -- Classe: shelve.Shelf (dict, protocol=None, writeback=False,
          keyencoding='utf-8')

     A subclass of *note collections.abc.MutableMapping: 12b4. which
     stores pickled values in the 'dict' object.

     By default, pickles created with *note pickle.DEFAULT_PROTOCOL:
     a31. are used to serialize values.  The version of the pickle
     protocol can be specified with the 'protocol' parameter.  See the
     *note pickle: ab. documentation for a discussion of the pickle
     protocols.

     If the 'writeback' parameter is ‘True’, the object will hold a
     cache of all entries accessed and write them back to the 'dict' at
     sync and close times.  This allows natural operations on mutable
     entries, but can consume much more memory and make sync and close
     take a long time.

     The 'keyencoding' parameter is the encoding used to encode keys
     before they are used with the underlying dict.

     A *note Shelf: 119d. object can also be used as a context manager,
     in which case it will be automatically closed when the *note with:
     186. block ends.

     Cambiato nella versione 3.2: Added the 'keyencoding' parameter;
     previously, keys were always encoded in UTF-8.

     Cambiato nella versione 3.4: Added context manager support.

     Cambiato nella versione 3.10: *note pickle.DEFAULT_PROTOCOL: a31.
     is now used as the default pickle protocol.

 -- Classe: shelve.BsdDbShelf (dict, protocol=None, writeback=False,
          keyencoding='utf-8')

     A subclass of *note Shelf: 119d. which exposes ‘first()’, ‘next()’,
     ‘previous()’, ‘last()’ and ‘set_location()’ methods.  These are
     available in the third-party ‘bsddb’ module from pybsddb(1) but not
     in other database modules.  The 'dict' object passed to the
     constructor must support those methods.  This is generally
     accomplished by calling one of ‘bsddb.hashopen()’, ‘bsddb.btopen()’
     or ‘bsddb.rnopen()’.  The optional 'protocol', 'writeback', and
     'keyencoding' parameters have the same interpretation as for the
     *note Shelf: 119d. class.

 -- Classe: shelve.DbfilenameShelf (filename, flag='c', protocol=None,
          writeback=False)

     A subclass of *note Shelf: 119d. which accepts a 'filename' instead
     of a dict-like object.  The underlying file will be opened using
     *note dbm.open(): 112e.  By default, the file will be created and
     opened for both read and write.  The optional 'flag' parameter has
     the same interpretation as for the *note open(): 1a59. function.
     The optional 'protocol' and 'writeback' parameters have the same
     interpretation as for the *note Shelf: 119d. class.

   ---------- Footnotes ----------

   (1) https://www.jcea.es/programacion/pybsddb.htm


File: python.info,  Node: Example<6>,  Prev: Restrictions,  Up: shelve — Python object persistence

5.12.3.2 Example
................

To summarize the interface (‘key’ is a string, ‘data’ is an arbitrary
object):

     import shelve

     d = shelve.open(filename)  # open -- file may get suffix added by low-level
                                # library

     d[key] = data              # store data at key (overwrites old data if
                                # using an existing key)
     data = d[key]              # retrieve a COPY of data at key (raise KeyError
                                # if no such key)
     del d[key]                 # delete data stored at key (raises KeyError
                                # if no such key)

     flag = key in d            # true if the key exists
     klist = list(d.keys())     # a list of all existing keys (slow!)

     # as d was opened WITHOUT writeback=True, beware:
     d['xx'] = [0, 1, 2]        # this works as expected, but...
     d['xx'].append(3)          # *this doesn't!* -- d['xx'] is STILL [0, 1, 2]!

     # having opened d without writeback=True, you need to code carefully:
     temp = d['xx']             # extracts the copy
     temp.append(5)             # mutates the copy
     d['xx'] = temp             # stores the copy right back, to persist it

     # or, d=shelve.open(filename,writeback=True) would let you just code
     # d['xx'].append(5) and have it work as expected, BUT it would also
     # consume more memory and make the d.close() operation slower.

     d.close()                  # close it

Vedi anche
..........

Module *note dbm: 35.

     Generic interface to ‘dbm’-style databases.

Module *note pickle: ab.

     Object serialization used by *note shelve: c8.


File: python.info,  Node: marshal — Internal Python object serialization,  Next: dbm — Interfaces to Unix «databases»,  Prev: shelve — Python object persistence,  Up: Data Persistence

5.12.4 ‘marshal’ — Internal Python object serialization
-------------------------------------------------------

__________________________________________________________________

This module contains functions that can read and write Python values in
a binary format.  The format is specific to Python, but independent of
machine architecture issues (e.g., you can write a Python value to a
file on a PC, transport the file to a Mac, and read it back there).
Details of the format are undocumented on purpose; it may change between
Python versions (although it rarely does).  (1)

This is not a general «persistence» module.  For general persistence and
transfer of Python objects through RPC calls, see the modules *note
pickle: ab. and *note shelve: c8.  The *note marshal: 91. module exists
mainly to support reading and writing the «pseudo-compiled» code for
Python modules of ‘.pyc’ files.  Therefore, the Python maintainers
reserve the right to modify the marshal format in backward incompatible
ways should the need arise.  The format of code objects is not
compatible between Python versions, even if the version of the format is
the same.  De-serializing a code object in the incorrect Python version
has undefined behavior.  If you’re serializing and de-serializing Python
objects, use the *note pickle: ab. module instead – the performance is
comparable, version independence is guaranteed, and pickle supports a
substantially wider range of objects than marshal.

     Avvertimento: The *note marshal: 91. module is not intended to be
     secure against erroneous or maliciously constructed data.  Never
     unmarshal data received from an untrusted or unauthenticated
     source.

There are functions that read/write files as well as functions operating
on bytes-like objects.

Not all Python object types are supported; in general, only objects
whose value is independent from a particular invocation of Python can be
written and read by this module.  The following types are supported:

   * Numeric types: *note int: 19b, *note bool: 3c3, *note float: 196,
     *note complex: 197.

   * Strings (*note str: 169.) and *note bytes: 192.  *note Bytes-like
     objects: 193. like *note bytearray: 344. are marshalled as ‘bytes’.

   * Containers: *note tuple: 614, *note list: 24d, *note set: 184,
     *note frozenset: 7f3, and (since *note version: 2d28. 5), *note
     slice: 695.  It should be understood that these are supported only
     if the values contained therein are themselves supported.
     Recursive containers are supported since *note version: 2d28. 3.

   * The singletons *note None: 886, *note Ellipsis: 2311. and *note
     StopIteration: df7.

   * *note code: 1b. objects, if 'allow_code' is true.  See note above
     about version dependence.

Cambiato nella versione 3.4:

   * Added format version 3, which supports marshalling recursive lists,
     sets and dictionaries.

   * Added format version 4, which supports efficient representations of
     short strings.

Cambiato nella versione 3.14: Added format version 5, which allows
marshalling slices.

The module defines these functions:

 -- Funzione: marshal.dump (value, file, version=version, /, *,
          allow_code=True)

     Write the value on the open file.  The value must be a supported
     type.  The file must be a writeable *note binary file: 2058.

     If the value has (or contains an object that has) an unsupported
     type, a *note ValueError: 2ec. exception is raised — but garbage
     data will also be written to the file.  The object will not be
     properly read back by *note load(): 1dde.  *note Code objects: 4e7.
     are only supported if 'allow_code' is true.

     The 'version' argument indicates the data format that ‘dump’ should
     use (see below).

     Raises an *note auditing event: 1c56. ‘marshal.dumps’ with
     arguments ‘value’, ‘version’.

     Cambiato nella versione 3.13: Added the 'allow_code' parameter.

 -- Funzione: marshal.load (file, /, *, allow_code=True)

     Read one value from the open file and return it.  If no valid value
     is read (e.g.  because the data has a different Python version’s
     incompatible marshal format), raise *note EOFError: 14e1, *note
     ValueError: 2ec. or *note TypeError: 198.  *note Code objects: 4e7.
     are only supported if 'allow_code' is true.  The file must be a
     readable *note binary file: 2058.

     Raises an *note auditing event: 1c56. ‘marshal.load’ with no
     arguments.

          Nota: If an object containing an unsupported type was
          marshalled with *note dump(): 2d29, *note load(): 1dde. will
          substitute ‘None’ for the unmarshallable type.

     Cambiato nella versione 3.10: This call used to raise a
     ‘code.__new__’ audit event for each code object.  Now it raises a
     single ‘marshal.load’ event for the entire load operation.

     Cambiato nella versione 3.13: Added the 'allow_code' parameter.

 -- Funzione: marshal.dumps (value, version=version, /, *,
          allow_code=True)

     Return the bytes object that would be written to a file by
     ‘dump(value, file)’.  The value must be a supported type.  Raise a
     *note ValueError: 2ec. exception if value has (or contains an
     object that has) an unsupported type.  *note Code objects: 4e7. are
     only supported if 'allow_code' is true.

     The 'version' argument indicates the data format that ‘dumps’
     should use (see below).

     Raises an *note auditing event: 1c56. ‘marshal.dumps’ with
     arguments ‘value’, ‘version’.

     Cambiato nella versione 3.13: Added the 'allow_code' parameter.

 -- Funzione: marshal.loads (bytes, /, *, allow_code=True)

     Convert the *note bytes-like object: 193. to a value.  If no valid
     value is found, raise *note EOFError: 14e1, *note ValueError: 2ec.
     or *note TypeError: 198.  *note Code objects: 4e7. are only
     supported if 'allow_code' is true.  Extra bytes in the input are
     ignored.

     Raises an *note auditing event: 1c56. ‘marshal.loads’ with argument
     ‘bytes’.

     Cambiato nella versione 3.10: This call used to raise a
     ‘code.__new__’ audit event for each code object.  Now it raises a
     single ‘marshal.loads’ event for the entire load operation.

     Cambiato nella versione 3.13: Added the 'allow_code' parameter.

In addition, the following constants are defined:

 -- Dati: marshal.version

     Indicates the format that the module uses.  Version 0 is the
     historical first version; subsequent versions add new features.
     Generally, a new version becomes the default when it is introduced.

     Version     Available since     New features
                                     
     -----------------------------------------------------------------------------------------
                                     
     1           Python 2.4          Sharing interned strings
                                     
                                     
     2           Python 2.5          Binary representation of floats
                                     
                                     
     3           Python 3.4          Support for object instancing and recursion
                                     
                                     
     4           Python 3.4          Efficient representation of short strings
                                     
                                     
     5           Python 3.14         Support for *note slice: 695. objects
                                     

   ---------- Footnotes ----------

   (1) The name of this module stems from a bit of terminology used by
the designers of Modula-3 (amongst others), who use the term
«marshalling» for shipping of data around in a self-contained form.
Strictly speaking, «to marshal» means to convert some data from internal
to external form (in an RPC buffer for instance) and «unmarshalling» for
the reverse process.


File: python.info,  Node: dbm — Interfaces to Unix «databases»,  Next: sqlite3 — DB-API 2 0 interface for SQLite databases,  Prev: marshal — Internal Python object serialization,  Up: Data Persistence

5.12.5 ‘dbm’ — Interfaces to Unix «databases»
---------------------------------------------

'Source code:' Lib/dbm/__init__.py(1)

__________________________________________________________________

*note dbm: 35. is a generic interface to variants of the DBM database:

   * *note dbm.sqlite3: 39.

   * *note dbm.gnu: 37.

   * *note dbm.ndbm: 38.

If none of these modules are installed, the slow-but-simple
implementation in module *note dbm.dumb: 36. will be used.  There is a
third party interface(2) to the Oracle Berkeley DB.

 -- Eccezione: dbm.error

     A tuple containing the exceptions that can be raised by each of the
     supported modules, with a unique exception also named *note
     dbm.error: 2d2e. as the first item — the latter is used when *note
     dbm.error: 2d2e. is raised.

 -- Funzione: dbm.whichdb (filename)

     This function attempts to guess which of the several simple
     database modules available — *note dbm.sqlite3: 39, *note dbm.gnu:
     37, *note dbm.ndbm: 38, or *note dbm.dumb: 36. — should be used to
     open a given file.

     Return one of the following values:

        * ‘None’ if the file can’t be opened because it’s unreadable or
          doesn’t exist

        * the empty string (‘''’) if the file’s format can’t be guessed

        * a string containing the required module name, such as
          ‘'dbm.ndbm'’ or ‘'dbm.gnu'’

     Cambiato nella versione 3.11: 'filename' accepts a *note path-like
     object: 5a1.

 -- Funzione: dbm.open (file, flag='r', mode=0o666)

     Open a database and return the corresponding database object.


     Parametri:

        * ‘file’ (*note path-like object: 5a1.) – The database file to
          open.

          If the database file already exists, the *note whichdb():
          2d2f. function is used to determine its type and the
          appropriate module is used; if it does not exist, the first
          submodule listed above that can be imported is used.

        * ‘flag’ (*note str: 169.) –

             * ‘'r'’ (default): Open existing database for reading only.

             * ‘'w'’: Open existing database for reading and writing.

             * ‘'c'’: Open database for reading and writing, creating it
               if it doesn’t exist.

             * ‘'n'’: Always create a new, empty database, open for
               reading and writing.

        * ‘mode’ (*note int: 19b.) – The Unix file access mode of the
          file (default: octal ‘0o666’), used only when the database has
          to be created.

     Cambiato nella versione 3.11: 'file' accepts a *note path-like
     object: 5a1.

The object returned by *note open(): 112e. supports the basic
functionality of mutable *note mappings: 13c3.; keys and their
corresponding values can be stored, retrieved, and deleted, and
iteration, the *note in: 34b. operator and methods ‘keys()’, ‘get()’,
‘setdefault()’ and ‘clear()’ are available.  The ‘keys()’ method returns
a list instead of a view object.  The ‘setdefault()’ method requires two
arguments.

Key and values are always stored as *note bytes: 192.  This means that
when strings are used they are implicitly converted to the default
encoding before being stored.

These objects also support being used in a *note with: 186. statement,
which will automatically close them when done.

Cambiato nella versione 3.2: ‘get()’ and ‘setdefault()’ methods are now
available for all *note dbm: 35. backends.

Cambiato nella versione 3.4: Added native support for the context
management protocol to the objects returned by *note open(): 112e.

Cambiato nella versione 3.8: Deleting a key from a read-only database
raises a database module specific exception instead of *note KeyError:
5e7.

Cambiato nella versione 3.13: ‘clear()’ methods are now available for
all *note dbm: 35. backends.

The following example records some hostnames and a corresponding title,
and then prints out the contents of the database:

     import dbm

     # Open database, creating it if necessary.
     with dbm.open('cache', 'c') as db:

         # Record some values
         db[b'hello'] = b'there'
         db['www.python.org'] = 'Python Website'
         db['www.cnn.com'] = 'Cable News Network'

         # Note that the keys are considered bytes now.
         assert db[b'www.python.org'] == b'Python Website'
         # Notice how the value is now in bytes.
         assert db['www.cnn.com'] == b'Cable News Network'

         # Often-used methods of the dict interface work too.
         print(db.get('python.org', b'not present'))

         # Storing a non-string key or value will raise an exception (most
         # likely a TypeError).
         db['www.yahoo.com'] = 4

     # db is automatically closed when leaving the with statement.

Vedi anche
..........

Module *note shelve: c8.

     Persistence module which stores non-string data.

The individual submodules are described in the following sections.

* Menu:

* dbm.sqlite3 — SQLite backend for dbm: dbm sqlite3 — SQLite backend for dbm.
* dbm.gnu — GNU database manager: dbm gnu — GNU database manager.
* dbm.ndbm — New Database Manager: dbm ndbm — New Database Manager.
* dbm.dumb — Portable DBM implementation: dbm dumb — Portable DBM implementation.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/dbm/__init__.py

   (2) https://www.jcea.es/programacion/pybsddb.htm


File: python.info,  Node: dbm sqlite3 — SQLite backend for dbm,  Next: dbm gnu — GNU database manager,  Up: dbm — Interfaces to Unix «databases»

5.12.5.1 ‘dbm.sqlite3’ — SQLite backend for dbm
...............................................

Added in version 3.13.

'Source code:' Lib/dbm/sqlite3.py(1)

__________________________________________________________________

This module uses the standard library *note sqlite3: d4. module to
provide an SQLite backend for the *note dbm: 35. module.  The files
created by *note dbm.sqlite3: 39. can thus be opened by *note sqlite3:
d4, or any other SQLite browser, including the SQLite CLI.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

 -- Funzione: dbm.sqlite3.open (filename, /, flag='r', mode=0o666)

     Open an SQLite database.


     Parametri:

        * ‘filename’ (*note path-like object: 5a1.) – The path to the
          database to be opened.

        * ‘flag’ (*note str: 169.) –

             * ‘'r'’ (default): Open existing database for reading only.

             * ‘'w'’: Open existing database for reading and writing.

             * ‘'c'’: Open database for reading and writing, creating it
               if it doesn’t exist.

             * ‘'n'’: Always create a new, empty database, open for
               reading and writing.

        * ‘mode’ – The Unix file access mode of the file (default: octal
          ‘0o666’), used only when the database has to be created.

     The returned database object behaves similar to a mutable *note
     mapping: 13c3, but the ‘keys()’ method returns a list, and the
     ‘setdefault()’ method requires two arguments.  It also supports a
     «closing» context manager via the *note with: 186. keyword.

     The following method is also provided:

      -- Metodo: sqlite3.close ()

          Close the SQLite database.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/dbm/sqlite3.py


File: python.info,  Node: dbm gnu — GNU database manager,  Next: dbm ndbm — New Database Manager,  Prev: dbm sqlite3 — SQLite backend for dbm,  Up: dbm — Interfaces to Unix «databases»

5.12.5.2 ‘dbm.gnu’ — GNU database manager
.........................................

'Source code:' Lib/dbm/gnu.py(1)

__________________________________________________________________

The *note dbm.gnu: 37. module provides an interface to the GDBM (GNU
dbm) library, similar to the *note dbm.ndbm: 38. module, but with
additional functionality like crash tolerance.

     Nota: The file formats created by *note dbm.gnu: 37. and *note
     dbm.ndbm: 38. are incompatible and can not be used interchangeably.

*note Availability: 2128.: not Android, not iOS, not WASI.

This module is not supported on *note mobile platforms: 2245. or *note
WebAssembly platforms: 1b52.

 -- Eccezione: dbm.gnu.error

     Raised on *note dbm.gnu: 37.-specific errors, such as I/O errors.
     *note KeyError: 5e7. is raised for general mapping errors like
     specifying an incorrect key.

 -- Dati: dbm.gnu.open_flags

     A string of characters the 'flag' parameter of *note open(): 1e08.
     supports.

 -- Funzione: dbm.gnu.open (filename, flag='r', mode=0o666, /)

     Open a GDBM database and return a ‘gdbm’ object.


     Parametri:

        * ‘filename’ (*note path-like object: 5a1.) – The database file
          to open.

        * ‘flag’ (*note str: 169.) –

             * ‘'r'’ (default): Open existing database for reading only.

             * ‘'w'’: Open existing database for reading and writing.

             * ‘'c'’: Open database for reading and writing, creating it
               if it doesn’t exist.

             * ‘'n'’: Always create a new, empty database, open for
               reading and writing.

          The following additional characters may be appended to control
          how the database is opened:

             * ‘'f'’: Open the database in fast mode.  Writes to the
               database will not be synchronized.

             * ‘'s'’: Synchronized mode.  Changes to the database will
               be written immediately to the file.

             * ‘'u'’: Do not lock database.

          Not all flags are valid for all versions of GDBM. See the
          *note open_flags: 2d34. member for a list of supported flag
          characters.

        * ‘mode’ (*note int: 19b.) – The Unix file access mode of the
          file (default: octal ‘0o666’), used only when the database has
          to be created.


     Solleva: *note error: c93. – If an invalid 'flag' argument is
     passed.

     Cambiato nella versione 3.11: 'filename' accepts a *note path-like
     object: 5a1.

     ‘gdbm’ objects behave similar to mutable *note mappings: 13c3, but
     methods ‘items()’, ‘values()’, ‘pop()’, ‘popitem()’, and ‘update()’
     are not supported, the ‘keys()’ method returns a list, and the
     ‘setdefault()’ method requires two arguments.  It also supports a
     «closing» context manager via the *note with: 186. keyword.

     Cambiato nella versione 3.2: Added the ‘get()’ and ‘setdefault()’
     methods.

     Cambiato nella versione 3.13: Added the ‘clear()’ method.

     The following methods are also provided:

      -- Metodo: gdbm.close ()

          Close the GDBM database.

      -- Metodo: gdbm.firstkey ()

          It’s possible to loop over every key in the database using
          this method and the *note nextkey(): 2d37. method.  The
          traversal is ordered by GDBM’s internal hash values, and won’t
          be sorted by the key values.  This method returns the starting
          key.

      -- Metodo: gdbm.nextkey (key)

          Returns the key that follows 'key' in the traversal.  The
          following code prints every key in the database ‘db’, without
          having to create a list in memory that contains them all:

               k = db.firstkey()
               while k is not None:
                   print(k)
                   k = db.nextkey(k)

      -- Metodo: gdbm.reorganize ()

          If you have carried out a lot of deletions and would like to
          shrink the space used by the GDBM file, this routine will
          reorganize the database.  ‘gdbm’ objects will not shorten the
          length of a database file except by using this reorganization;
          otherwise, deleted file space will be kept and reused as new
          (key, value) pairs are added.

      -- Metodo: gdbm.sync ()

          When the database has been opened in fast mode, this method
          forces any unwritten data to be written to the disk.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/dbm/gnu.py


File: python.info,  Node: dbm ndbm — New Database Manager,  Next: dbm dumb — Portable DBM implementation,  Prev: dbm gnu — GNU database manager,  Up: dbm — Interfaces to Unix «databases»

5.12.5.3 ‘dbm.ndbm’ — New Database Manager
..........................................

'Source code:' Lib/dbm/ndbm.py(1)

__________________________________________________________________

The *note dbm.ndbm: 38. module provides an interface to the NDBM (New
Database Manager) library.  This module can be used with the «classic»
NDBM interface or the GDBM compatibility interface.

     Nota: The file formats created by *note dbm.gnu: 37. and *note
     dbm.ndbm: 38. are incompatible and can not be used interchangeably.

     Avvertimento: The NDBM library shipped as part of macOS has an
     undocumented limitation on the size of values, which can result in
     corrupted database files when storing values larger than this
     limit.  Reading such corrupted files can result in a hard crash
     (segmentation fault).

*note Availability: 2128.: not Android, not iOS, not WASI.

This module is not supported on *note mobile platforms: 2245. or *note
WebAssembly platforms: 1b52.

 -- Eccezione: dbm.ndbm.error

     Raised on *note dbm.ndbm: 38.-specific errors, such as I/O errors.
     *note KeyError: 5e7. is raised for general mapping errors like
     specifying an incorrect key.

 -- Dati: dbm.ndbm.library

     Name of the NDBM implementation library used.

 -- Funzione: dbm.ndbm.open (filename, flag='r', mode=0o666, /)

     Open an NDBM database and return an ‘ndbm’ object.


     Parametri:

        * ‘filename’ (*note path-like object: 5a1.) – The basename of
          the database file (without the ‘.dir’ or ‘.pag’ extensions).

        * ‘flag’ (*note str: 169.) –

             * ‘'r'’ (default): Open existing database for reading only.

             * ‘'w'’: Open existing database for reading and writing.

             * ‘'c'’: Open database for reading and writing, creating it
               if it doesn’t exist.

             * ‘'n'’: Always create a new, empty database, open for
               reading and writing.

        * ‘mode’ (*note int: 19b.) – The Unix file access mode of the
          file (default: octal ‘0o666’), used only when the database has
          to be created.

     Cambiato nella versione 3.11: Accepts *note path-like object: 5a1.
     for filename.

     ‘ndbm’ objects behave similar to mutable *note mappings: 13c3, but
     methods ‘items()’, ‘values()’, ‘pop()’, ‘popitem()’, and ‘update()’
     are not supported, the ‘keys()’ method returns a list, and the
     ‘setdefault()’ method requires two arguments.  It also supports a
     «closing» context manager via the *note with: 186. keyword.

     Cambiato nella versione 3.2: Added the ‘get()’ and ‘setdefault()’
     methods.

     Cambiato nella versione 3.13: Added the ‘clear()’ method.

     The following method is also provided:

      -- Metodo: ndbm.close ()

          Close the NDBM database.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/dbm/ndbm.py


File: python.info,  Node: dbm dumb — Portable DBM implementation,  Prev: dbm ndbm — New Database Manager,  Up: dbm — Interfaces to Unix «databases»

5.12.5.4 ‘dbm.dumb’ — Portable DBM implementation
.................................................

'Source code:' Lib/dbm/dumb.py(1)

     Nota: The *note dbm.dumb: 36. module is intended as a last resort
     fallback for the *note dbm: 35. module when a more robust module is
     not available.  The *note dbm.dumb: 36. module is not written for
     speed and is not nearly as heavily used as the other database
     modules.

__________________________________________________________________

The *note dbm.dumb: 36. module provides a persistent *note dict:
183.-like interface which is written entirely in Python.  Unlike other
*note dbm: 35. backends, such as *note dbm.gnu: 37, no external library
is required.

The ‘dbm.dumb’ module defines the following:

 -- Eccezione: dbm.dumb.error

     Raised on *note dbm.dumb: 36.-specific errors, such as I/O errors.
     *note KeyError: 5e7. is raised for general mapping errors like
     specifying an incorrect key.

 -- Funzione: dbm.dumb.open (filename, flag='c', mode=0o666)

     Open a ‘dbm.dumb’ database.


     Parametri:

        * ‘filename’ – The basename of the database file (without
          extensions).  A new database creates the following files:

             - ‘`filename'.dat’

             - ‘`filename'.dir’

        * ‘flag’ (*note str: 169.) –

             * ‘'r'’: Open existing database for reading only.

             * ‘'w'’: Open existing database for reading and writing.

             * ‘'c'’ (default): Open database for reading and writing,
               creating it if it doesn’t exist.

             * ‘'n'’: Always create a new, empty database, open for
               reading and writing.

        * ‘mode’ (*note int: 19b.) – The Unix file access mode of the
          file (default: octal ‘0o666’), used only when the database has
          to be created.

          Avvertimento: It is possible to crash the Python interpreter
          when loading a database with a sufficiently large/complex
          entry due to stack depth limitations in Python’s AST compiler.

     Cambiato nella versione 3.5: *note open(): c8f. always creates a
     new database when 'flag' is ‘'n'’.

     Cambiato nella versione 3.8: A database opened read-only if 'flag'
     is ‘'r'’.  A database is not created if it does not exist if 'flag'
     is ‘'r'’ or ‘'w'’.

     Cambiato nella versione 3.11: 'filename' accepts a *note path-like
     object: 5a1.

     The returned database object behaves similar to a mutable *note
     mapping: 13c3, but the ‘keys()’ and ‘items()’ methods return lists,
     and the ‘setdefault()’ method requires two arguments.  It also
     supports a «closing» context manager via the *note with: 186.
     keyword.

     The following methods are also provided:

      -- Metodo: dumbdbm.close ()

          Close the database.

      -- Metodo: dumbdbm.sync ()

          Synchronize the on-disk directory and data files.  This method
          is called by the *note shelve.Shelf.sync(): 2d20. method.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/dbm/dumb.py


File: python.info,  Node: sqlite3 — DB-API 2 0 interface for SQLite databases,  Prev: dbm — Interfaces to Unix «databases»,  Up: Data Persistence

5.12.6 ‘sqlite3’ — DB-API 2.0 interface for SQLite databases
------------------------------------------------------------

'Source code:' Lib/sqlite3/(1)

SQLite is a C library that provides a lightweight disk-based database
that doesn’t require a separate server process and allows accessing the
database using a nonstandard variant of the SQL query language.  Some
applications can use SQLite for internal data storage.  It’s also
possible to prototype an application using SQLite and then port the code
to a larger database such as PostgreSQL or Oracle.

The ‘sqlite3’ module was written by Gerhard Häring.  It provides an SQL
interface compliant with the DB-API 2.0 specification described by PEP
249(2), and requires the third-party SQLite(3) library.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

This document includes four main sections:

   * *note Tutorial: 2d44. teaches how to use the ‘sqlite3’ module.

   * *note Reference: 2d45. describes the classes and functions this
     module defines.

   * *note How-to guides: 2d46. details how to handle specific tasks.

   * *note Explanation: 2d47. provides in-depth background on
     transaction control.

Vedi anche
..........

‘https://www.sqlite.org’

     The SQLite web page; the documentation describes the syntax and the
     available data types for the supported SQL dialect.

‘https://www.w3schools.com/sql/’

     Tutorial, reference and examples for learning SQL syntax.

PEP 249(4) - Database API Specification 2.0

     PEP written by Marc-André Lemburg.

* Menu:

* Tutorial::
* Reference::
* How-to guides::
* Explanation::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/sqlite3/

   (2) https://peps.python.org/pep-0249/

   (3) https://sqlite.org/

   (4) https://peps.python.org/pep-0249/


File: python.info,  Node: Tutorial,  Next: Reference,  Up: sqlite3 — DB-API 2 0 interface for SQLite databases

5.12.6.1 Tutorial
.................

In this tutorial, you will create a database of Monty Python movies
using basic ‘sqlite3’ functionality.  It assumes a fundamental
understanding of database concepts, including cursors(1) and
transactions(2).

First, we need to create a new database and open a database connection
to allow ‘sqlite3’ to work with it.  Call *note sqlite3.connect(): 5a6.
to create a connection to the database ‘tutorial.db’ in the current
working directory, implicitly creating it if it does not exist:

     import sqlite3
     con = sqlite3.connect("tutorial.db")

The returned *note Connection: 54e. object ‘con’ represents the
connection to the on-disk database.

In order to execute SQL statements and fetch results from SQL queries,
we will need to use a database cursor.  Call *note con.cursor(): 2d49.
to create the *note Cursor: 2d4a.:

     cur = con.cursor()

Now that we’ve got a database connection and a cursor, we can create a
database table ‘movie’ with columns for title, release year, and review
score.  For simplicity, we can just use column names in the table
declaration – thanks to the flexible typing(3) feature of SQLite,
specifying the data types is optional.  Execute the ‘CREATE TABLE’
statement by calling *note cur.execute(...): 5b0.:

     cur.execute("CREATE TABLE movie(title, year, score)")

We can verify that the new table has been created by querying the
‘sqlite_master’ table built-in to SQLite, which should now contain an
entry for the ‘movie’ table definition (see The Schema Table(4) for
details).  Execute that query by calling *note cur.execute(...): 5b0,
assign the result to ‘res’, and call *note res.fetchone(): 2d4b. to
fetch the resulting row:

     >>> res = cur.execute("SELECT name FROM sqlite_master")
     >>> res.fetchone()
     ('movie',)

We can see that the table has been created, as the query returns a *note
tuple: 614. containing the table’s name.  If we query ‘sqlite_master’
for a non-existent table ‘spam’, ‘res.fetchone()’ will return ‘None’:

     >>> res = cur.execute("SELECT name FROM sqlite_master WHERE name='spam'")
     >>> res.fetchone() is None
     True

Now, add two rows of data supplied as SQL literals by executing an
‘INSERT’ statement, once again by calling *note cur.execute(...): 5b0.:

     cur.execute("""
         INSERT INTO movie VALUES
             ('Monty Python and the Holy Grail', 1975, 8.2),
             ('And Now for Something Completely Different', 1971, 7.5)
     """)

The ‘INSERT’ statement implicitly opens a transaction, which needs to be
committed before changes are saved in the database (see *note
Transaction control: 2d4c. for details).  Call *note con.commit(): 2d4d.
on the connection object to commit the transaction:

     con.commit()

We can verify that the data was inserted correctly by executing a
‘SELECT’ query.  Use the now-familiar *note cur.execute(...): 5b0. to
assign the result to ‘res’, and call *note res.fetchall(): 2d4e. to
return all resulting rows:

     >>> res = cur.execute("SELECT score FROM movie")
     >>> res.fetchall()
     [(8.2,), (7.5,)]

The result is a *note list: 24d. of two ‘tuple’s, one per row, each
containing that row’s ‘score’ value.

Now, insert three more rows by calling *note cur.executemany(...): 5b1.:

     data = [
         ("Monty Python Live at the Hollywood Bowl", 1982, 7.9),
         ("Monty Python's The Meaning of Life", 1983, 7.5),
         ("Monty Python's Life of Brian", 1979, 8.0),
     ]
     cur.executemany("INSERT INTO movie VALUES(?, ?, ?)", data)
     con.commit()  # Remember to commit the transaction after executing INSERT.

Notice that ‘?’ placeholders are used to bind ‘data’ to the query.
Always use placeholders instead of *note string formatting: 2044. to
bind Python values to SQL statements, to avoid SQL injection attacks(5)
(see *note How to use placeholders to bind values in SQL queries: 5b2.
for more details).

We can verify that the new rows were inserted by executing a ‘SELECT’
query, this time iterating over the results of the query:

     >>> for row in cur.execute("SELECT year, title FROM movie ORDER BY year"):
     ...     print(row)
     (1971, 'And Now for Something Completely Different')
     (1975, 'Monty Python and the Holy Grail')
     (1979, "Monty Python's Life of Brian")
     (1982, 'Monty Python Live at the Hollywood Bowl')
     (1983, "Monty Python's The Meaning of Life")

Each row is a two-item *note tuple: 614. of ‘(year, title)’, matching
the columns selected in the query.

Finally, verify that the database has been written to disk by calling
*note con.close(): 54f. to close the existing connection, opening a new
one, creating a new cursor, then querying the database:

     >>> con.close()
     >>> new_con = sqlite3.connect("tutorial.db")
     >>> new_cur = new_con.cursor()
     >>> res = new_cur.execute("SELECT title, year FROM movie ORDER BY score DESC")
     >>> title, year = res.fetchone()
     >>> print(f'The highest scoring Monty Python movie is {title!r}, released in {year}')
     The highest scoring Monty Python movie is 'Monty Python and the Holy Grail', released in 1975
     >>> new_con.close()

You’ve now created an SQLite database using the ‘sqlite3’ module,
inserted data and retrieved values from it in multiple ways.

Vedi anche
..........

   * *note How-to guides: 2d46. for further reading:

        * *note How to use placeholders to bind values in SQL queries:
          5b2.

        * *note How to adapt custom Python types to SQLite values: 2d4f.

        * *note How to convert SQLite values to custom Python types:
          2d50.

        * *note How to use the connection context manager: 1b54.

        * *note How to create and use row factories: 2d51.

   * *note Explanation: 2d47. for in-depth background on transaction
     control.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Cursor_(databases)

   (2) https://en.wikipedia.org/wiki/Database_transaction

   (3) https://www.sqlite.org/flextypegood.html

   (4) https://www.sqlite.org/schematab.html

   (5) https://en.wikipedia.org/wiki/SQL_injection


File: python.info,  Node: Reference,  Next: How-to guides,  Prev: Tutorial,  Up: sqlite3 — DB-API 2 0 interface for SQLite databases

5.12.6.2 Reference
..................

* Menu:

* Module functions::
* Module constants::
* Connection objects::
* Cursor objects::
* Row objects::
* Blob objects::
* PrepareProtocol objects::
* Exceptions: Exceptions<6>.
* SQLite and Python types::
* Default adapters and converters (deprecated): Default adapters and converters deprecated.
* Command-line interface: Command-line interface<2>.


File: python.info,  Node: Module functions,  Next: Module constants,  Up: Reference

5.12.6.3 Module functions
.........................

 -- Funzione: sqlite3.connect (database, timeout=5.0, detect_types=0,
          isolation_level='DEFERRED', check_same_thread=True,
          factory=sqlite3.Connection, cached_statements=128, uri=False,
          *, autocommit=sqlite3.LEGACY_TRANSACTION_CONTROL)

     Open a connection to an SQLite database.


     Parametri:

        * ‘database’ (*note path-like object: 5a1.) – The path to the
          database file to be opened.  You can pass ‘":memory:"’ to
          create an SQLite database existing only in memory(1), and open
          a connection to it.

        * ‘timeout’ (*note float: 196.) – How many seconds the
          connection should wait before raising an *note
          OperationalError: 1c3a. when a table is locked.  If another
          connection opens a transaction to modify a table, that table
          will be locked until the transaction is committed.  Default
          five seconds.

        * ‘detect_types’ (*note int: 19b.) – Control whether and how
          data types not *note natively supported by SQLite: 2d56. are
          looked up to be converted to Python types, using the
          converters registered with *note register_converter(): 2d57.
          Set it to any combination (using ‘|’, bitwise or) of *note
          PARSE_DECLTYPES: 2d58. and *note PARSE_COLNAMES: 2d59. to
          enable this.  Column names takes precedence over declared
          types if both flags are set.  By default (‘0’), type detection
          is disabled.

        * ‘isolation_level’ (*note str: 169.‘ | ’‘None’) – Control
          legacy transaction handling behaviour.  See *note
          Connection.isolation_level: 2d5a. and *note Transaction
          control via the isolation_level attribute: 2d5b. for more
          information.  Can be ‘"DEFERRED"’ (default), ‘"EXCLUSIVE"’ or
          ‘"IMMEDIATE"’; or ‘None’ to disable opening transactions
          implicitly.  Has no effect unless *note Connection.autocommit:
          6de. is set to *note LEGACY_TRANSACTION_CONTROL: 2d5c. (the
          default).

        * ‘check_same_thread’ (*note bool: 3c3.) – If ‘True’ (default),
          *note ProgrammingError: 305. will be raised if the database
          connection is used by a thread other than the one that created
          it.  If ‘False’, the connection may be accessed in multiple
          threads; write operations may need to be serialized by the
          user to avoid data corruption.  See *note threadsafety: 88d.
          for more information.

        * ‘factory’ (*note Connection: 54e.) – A custom subclass of
          *note Connection: 54e. to create the connection with, if not
          the default *note Connection: 54e. class.

        * ‘cached_statements’ (*note int: 19b.) – The number of
          statements that ‘sqlite3’ should internally cache for this
          connection, to avoid parsing overhead.  By default, 128
          statements.

        * ‘uri’ (*note bool: 3c3.) – If set to ‘True’, 'database' is
          interpreted as a URI (Uniform Resource Identifier) with a file
          path and an optional query string.  The scheme part 'must' be
          ‘"file:"’, and the path can be relative or absolute.  The
          query string allows passing parameters to SQLite, enabling
          various *note How to work with SQLite URIs: 2d5d.

        * ‘autocommit’ (*note bool: 3c3.) – Control PEP 249(2)
          transaction handling behaviour.  See *note
          Connection.autocommit: 6de. and *note Transaction control via
          the autocommit attribute: 6df. for more information.
          'autocommit' currently defaults to *note
          LEGACY_TRANSACTION_CONTROL: 2d5c.  The default will change to
          ‘False’ in a future Python release.


     Tipo di ritorno: *note Connection: 54e.

     Raises an *note auditing event: 1c56. ‘sqlite3.connect’ with
     argument ‘database’.

     Raises an *note auditing event: 1c56. ‘sqlite3.connect/handle’ with
     argument ‘connection_handle’.

     Cambiato nella versione 3.4: Added the 'uri' parameter.

     Cambiato nella versione 3.7: 'database' can now also be a *note
     path-like object: 5a1, not only a string.

     Cambiato nella versione 3.10: Added the ‘sqlite3.connect/handle’
     auditing event.

     Cambiato nella versione 3.12: Added the 'autocommit' parameter.

     Cambiato nella versione 3.13: Positional use of the parameters
     'timeout', 'detect_types', 'isolation_level', 'check_same_thread',
     'factory', 'cached_statements', and 'uri' is deprecated.  They will
     become keyword-only parameters in Python 3.15.

 -- Funzione: sqlite3.complete_statement (statement)

     Return ‘True’ if the string 'statement' appears to contain one or
     more complete SQL statements.  No syntactic verification or parsing
     of any kind is performed, other than checking that there are no
     unclosed string literals and the statement is terminated by a
     semicolon.

     For example:

          >>> sqlite3.complete_statement("SELECT foo FROM bar;")
          True
          >>> sqlite3.complete_statement("SELECT foo")
          False

     This function may be useful during command-line input to determine
     if the entered text seems to form a complete SQL statement, or if
     additional input is needed before calling *note execute(): 5b0.

     See ‘runsource()’ in Lib/sqlite3/__main__.py(3) for real-world use.

 -- Funzione: sqlite3.enable_callback_tracebacks (flag, /)

     Enable or disable callback tracebacks.  By default you will not get
     any tracebacks in user-defined functions, aggregates, converters,
     authorizer callbacks etc.  If you want to debug them, you can call
     this function with 'flag' set to ‘True’.  Afterwards, you will get
     tracebacks from callbacks on *note sys.stderr: b35.  Use ‘False’ to
     disable the feature again.

          Nota: Errors in user-defined function callbacks are logged as
          unraisable exceptions.  Use an *note unraisable hook handler:
          508. for introspection of the failed callback.

 -- Funzione: sqlite3.register_adapter (type, adapter, /)

     Register an 'adapter' *note callable: 2d61. to adapt the Python
     type 'type' into an SQLite type.  The adapter is called with a
     Python object of type 'type' as its sole argument, and must return
     a value of a *note type that SQLite natively understands: 2d56.

 -- Funzione: sqlite3.register_converter (typename, converter, /)

     Register the 'converter' *note callable: 2d61. to convert SQLite
     objects of type 'typename' into a Python object of a specific type.
     The converter is invoked for all SQLite values of type 'typename';
     it is passed a *note bytes: 192. object and should return an object
     of the desired Python type.  Consult the parameter 'detect_types'
     of *note connect(): 5a6. for information regarding how type
     detection works.

     Note: 'typename' and the name of the type in your query are matched
     case-insensitively.

   ---------- Footnotes ----------

   (1) https://sqlite.org/inmemorydb.html

   (2) https://peps.python.org/pep-0249/

   (3) 
https://github.com/python/cpython/tree/3.14/Lib/sqlite3/__main__.py


File: python.info,  Node: Module constants,  Next: Connection objects,  Prev: Module functions,  Up: Reference

5.12.6.4 Module constants
.........................

 -- Dati: sqlite3.LEGACY_TRANSACTION_CONTROL

     Set *note autocommit: 6de. to this constant to select old style
     (pre-Python 3.12) transaction control behaviour.  See *note
     Transaction control via the isolation_level attribute: 2d5b. for
     more information.

 -- Dati: sqlite3.PARSE_DECLTYPES

     Pass this flag value to the 'detect_types' parameter of *note
     connect(): 5a6. to look up a converter function using the declared
     types for each column.  The types are declared when the database
     table is created.  ‘sqlite3’ will look up a converter function
     using the first word of the declared type as the converter
     dictionary key.  For example:

          CREATE TABLE test(
             i integer primary key,  ! will look up a converter named "integer"
             p point,                ! will look up a converter named "point"
             n number(10)            ! will look up a converter named "number"
           )

     This flag may be combined with *note PARSE_COLNAMES: 2d59. using
     the ‘|’ (bitwise or) operator.

          Nota: Generated fields (for example ‘MAX(p)’) are returned as
          *note str: 169.  Use ‘PARSE_COLNAMES’ to enforce types for
          such queries.

 -- Dati: sqlite3.PARSE_COLNAMES

     Pass this flag value to the 'detect_types' parameter of *note
     connect(): 5a6. to look up a converter function by using the type
     name, parsed from the query column name, as the converter
     dictionary key.  The query column name must be wrapped in double
     quotes (‘"’) and the type name must be wrapped in square brackets
     (‘[]’).

          SELECT MAX(p) as "p [point]" FROM test;  ! will look up converter "point"

     This flag may be combined with *note PARSE_DECLTYPES: 2d58. using
     the ‘|’ (bitwise or) operator.

 -- Dati: sqlite3.SQLITE_OK
 -- Dati: sqlite3.SQLITE_DENY
 -- Dati: sqlite3.SQLITE_IGNORE

     Flags that should be returned by the 'authorizer_callback' *note
     callable: 2d61. passed to *note Connection.set_authorizer(): 5a9,
     to indicate whether:

        * Access is allowed (‘SQLITE_OK’),

        * The SQL statement should be aborted with an error
          (‘SQLITE_DENY’)

        * The column should be treated as a ‘NULL’ value
          (‘SQLITE_IGNORE’)

 -- Dati: sqlite3.apilevel

     String constant stating the supported DB-API level.  Required by
     the DB-API. Hard-coded to ‘"2.0"’.

 -- Dati: sqlite3.paramstyle

     String constant stating the type of parameter marker formatting
     expected by the ‘sqlite3’ module.  Required by the DB-API.
     Hard-coded to ‘"qmark"’.

          Nota: The ‘named’ DB-API parameter style is also supported.

 -- Dati: sqlite3.sqlite_version

     Version number of the runtime SQLite library as a *note string:
     169.

 -- Dati: sqlite3.sqlite_version_info

     Version number of the runtime SQLite library as a *note tuple: 614.
     of *note integers: 19b.

 -- Dati: sqlite3.threadsafety

     Integer constant required by the DB-API 2.0, stating the level of
     thread safety the ‘sqlite3’ module supports.  This attribute is set
     based on the default threading mode(1) the underlying SQLite
     library is compiled with.  The SQLite threading modes are:

       1. 'Single-thread': In this mode, all mutexes are disabled and
          SQLite is unsafe to use in more than a single thread at once.

       2. 'Multi-thread': In this mode, SQLite can be safely used by
          multiple threads provided that no single database connection
          is used simultaneously in two or more threads.

       3. 'Serialized': In serialized mode, SQLite can be safely used by
          multiple threads with no restriction.

     The mappings from SQLite threading modes to DB-API 2.0 threadsafety
     levels are as follows:

     SQLite threading       threadsafety(2)            SQLITE_THREADSAFE(3)       DB-API 2.0 meaning
     mode                                                                         

     -----------------------------------------------------------------------------------------------------------------
                                                                                  
     single-thread          0                          0                          Threads may not share the module
                                                                                  
                                                                                  
     multi-thread           1                          2                          Threads may share the module, but
                                                                                  not connections
                                                                                  
                                                                                  
     serialized             3                          1                          Threads may share the module,
                                                                                  connections and cursors
                                                                                  

     Cambiato nella versione 3.11: Set 'threadsafety' dynamically
     instead of hard-coding it to ‘1’.

 -- Dati: sqlite3.SQLITE_DBCONFIG_DEFENSIVE
 -- Dati: sqlite3.SQLITE_DBCONFIG_DQS_DDL
 -- Dati: sqlite3.SQLITE_DBCONFIG_DQS_DML
 -- Dati: sqlite3.SQLITE_DBCONFIG_ENABLE_FKEY
 -- Dati: sqlite3.SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER
 -- Dati: sqlite3.SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION
 -- Dati: sqlite3.SQLITE_DBCONFIG_ENABLE_QPSG
 -- Dati: sqlite3.SQLITE_DBCONFIG_ENABLE_TRIGGER
 -- Dati: sqlite3.SQLITE_DBCONFIG_ENABLE_VIEW
 -- Dati: sqlite3.SQLITE_DBCONFIG_LEGACY_ALTER_TABLE
 -- Dati: sqlite3.SQLITE_DBCONFIG_LEGACY_FILE_FORMAT
 -- Dati: sqlite3.SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE
 -- Dati: sqlite3.SQLITE_DBCONFIG_RESET_DATABASE
 -- Dati: sqlite3.SQLITE_DBCONFIG_TRIGGER_EQP
 -- Dati: sqlite3.SQLITE_DBCONFIG_TRUSTED_SCHEMA
 -- Dati: sqlite3.SQLITE_DBCONFIG_WRITABLE_SCHEMA

     These constants are used for the *note Connection.setconfig(): 6e2.
     and *note getconfig(): 6e1. methods.

     The availability of these constants varies depending on the version
     of SQLite Python was compiled with.

     Added in version 3.12.

     Vedi anche
     ..........

     ‘https://www.sqlite.org/c3ref/c_dbconfig_defensive.html’

          SQLite docs: Database Connection Configuration Options

Deprecated since version 3.12, removed in version 3.14: The ‘version’
and ‘version_info’ constants.

   ---------- Footnotes ----------

   (1) https://sqlite.org/threadsafe.html

   (2) https://peps.python.org/pep-0249/#threadsafety

   (3) https://sqlite.org/compile.html#threadsafe


File: python.info,  Node: Connection objects,  Next: Cursor objects,  Prev: Module constants,  Up: Reference

5.12.6.5 Connection objects
...........................

 -- Classe: sqlite3.Connection

     Each open SQLite database is represented by a ‘Connection’ object,
     which is created using *note sqlite3.connect(): 5a6.  Their main
     purpose is creating *note Cursor: 2d4a. objects, and *note
     Transaction control: 2d4c.

     Vedi anche
     ..........

        * *note How to use connection shortcut methods: 2d7c.

        * *note How to use the connection context manager: 1b54.

     Cambiato nella versione 3.13: A *note ResourceWarning: 54d. is
     emitted if *note close(): 54f. is not called before a ‘Connection’
     object is deleted.

     An SQLite database connection has the following attributes and
     methods:

      -- Metodo: cursor (factory=Cursor)

          Create and return a *note Cursor: 2d4a. object.  The cursor
          method accepts a single optional parameter 'factory'.  If
          supplied, this must be a *note callable: 2d61. returning an
          instance of *note Cursor: 2d4a. or its subclasses.

      -- Metodo: blobopen (table, column, rowid, /, *, readonly=False,
               name='main')

          Open a *note Blob: 893. handle to an existing BLOB (Binary
          Large OBject).


          Parametri:

             * ‘table’ (*note str: 169.) – The name of the table where
               the blob is located.

             * ‘column’ (*note str: 169.) – The name of the column where
               the blob is located.

             * ‘rowid’ (*note int: 19b.) – The row id where the blob is
               located.

             * ‘readonly’ (*note bool: 3c3.) – Set to ‘True’ if the blob
               should be opened without write permissions.  Defaults to
               ‘False’.

             * ‘name’ (*note str: 169.) – The name of the database where
               the blob is located.  Defaults to ‘"main"’.


          Solleva: *note OperationalError: 1c3a. – When trying to open a
          blob in a ‘WITHOUT ROWID’ table.


          Tipo di ritorno: *note Blob: 893.

               Nota: The blob size cannot be changed using the *note
               Blob: 893. class.  Use the SQL function ‘zeroblob’ to
               create a blob with a fixed size.

          Added in version 3.11.

      -- Metodo: commit ()

          Commit any pending transaction to the database.  If *note
          autocommit: 6de. is ‘True’, or there is no open transaction,
          this method does nothing.  If ‘autocommit’ is ‘False’, a new
          transaction is implicitly opened if a pending transaction was
          committed by this method.

      -- Metodo: rollback ()

          Roll back to the start of any pending transaction.  If *note
          autocommit: 6de. is ‘True’, or there is no open transaction,
          this method does nothing.  If ‘autocommit’ is ‘False’, a new
          transaction is implicitly opened if a pending transaction was
          rolled back by this method.

      -- Metodo: close ()

          Close the database connection.  If *note autocommit: 6de. is
          ‘False’, any pending transaction is implicitly rolled back.
          If ‘autocommit’ is ‘True’ or *note LEGACY_TRANSACTION_CONTROL:
          2d5c, no implicit transaction control is executed.  Make sure
          to *note commit(): 2d4d. before closing to avoid losing
          pending changes.

      -- Metodo: execute (sql, parameters=(), /)

          Create a new *note Cursor: 2d4a. object and call *note
          execute(): 5b0. on it with the given 'sql' and 'parameters'.
          Return the new cursor object.

      -- Metodo: executemany (sql, parameters, /)

          Create a new *note Cursor: 2d4a. object and call *note
          executemany(): 5b1. on it with the given 'sql' and
          'parameters'.  Return the new cursor object.

      -- Metodo: executescript (sql_script, /)

          Create a new *note Cursor: 2d4a. object and call *note
          executescript(): 2d81. on it with the given 'sql_script'.
          Return the new cursor object.

      -- Metodo: create_function (name, narg, func, *,
               deterministic=False)

          Create or remove a user-defined SQL function.


          Parametri:

             * ‘name’ (*note str: 169.) – The name of the SQL function.

             * ‘narg’ (*note int: 19b.) – The number of arguments the
               SQL function can accept.  If ‘-1’, it may take any number
               of arguments.

             * ‘func’ (*note callback: 2d82. | None) – A *note callable:
               2d61. that is called when the SQL function is invoked.
               The callable must return *note a type natively supported
               by SQLite: 2d56.  Set to ‘None’ to remove an existing SQL
               function.

             * ‘deterministic’ (*note bool: 3c3.) – If ‘True’, the
               created SQL function is marked as deterministic(1), which
               allows SQLite to perform additional optimizations.

          Cambiato nella versione 3.8: Added the 'deterministic'
          parameter.

          Example:

               >>> import hashlib
               >>> def md5sum(t):
               ...     return hashlib.md5(t).hexdigest()
               >>> con = sqlite3.connect(":memory:")
               >>> con.create_function("md5", 1, md5sum)
               >>> for row in con.execute("SELECT md5(?)", (b"foo",)):
               ...     print(row)
               ('acbd18db4cc2f85cedef654fccc4a4d8',)
               >>> con.close()

          Cambiato nella versione 3.13: Passing 'name', 'narg', and
          'func' as keyword arguments is deprecated.  These parameters
          will become positional-only in Python 3.15.

      -- Metodo: create_aggregate (name, n_arg, aggregate_class)

          Create or remove a user-defined SQL aggregate function.


          Parametri:

             * ‘name’ (*note str: 169.) – The name of the SQL aggregate
               function.

             * ‘n_arg’ (*note int: 19b.) – The number of arguments the
               SQL aggregate function can accept.  If ‘-1’, it may take
               any number of arguments.

             * ‘aggregate_class’ (*note class: 1ce5. | None) – A class
               must implement the following methods:

                  * ‘step()’: Add a row to the aggregate.

                  * ‘finalize()’: Return the final result of the
                    aggregate as *note a type natively supported by
                    SQLite: 2d56.

               The number of arguments that the ‘step()’ method must
               accept is controlled by 'n_arg'.

               Set to ‘None’ to remove an existing SQL aggregate
               function.

          Example:

               class MySum:
                   def __init__(self):
                       self.count = 0

                   def step(self, value):
                       self.count += value

                   def finalize(self):
                       return self.count

               con = sqlite3.connect(":memory:")
               con.create_aggregate("mysum", 1, MySum)
               cur = con.execute("CREATE TABLE test(i)")
               cur.execute("INSERT INTO test(i) VALUES(1)")
               cur.execute("INSERT INTO test(i) VALUES(2)")
               cur.execute("SELECT mysum(i) FROM test")
               print(cur.fetchone()[0])

               con.close()

          Cambiato nella versione 3.13: Passing 'name', 'n_arg', and
          'aggregate_class' as keyword arguments is deprecated.  These
          parameters will become positional-only in Python 3.15.

      -- Metodo: create_window_function (name, num_params,
               aggregate_class, /)

          Create or remove a user-defined aggregate window function.


          Parametri:

             * ‘name’ (*note str: 169.) – The name of the SQL aggregate
               window function to create or remove.

             * ‘num_params’ (*note int: 19b.) – The number of arguments
               the SQL aggregate window function can accept.  If ‘-1’,
               it may take any number of arguments.

             * ‘aggregate_class’ (*note class: 1ce5. | None) – A class
               that must implement the following methods:

                  * ‘step()’: Add a row to the current window.

                  * ‘value()’: Return the current value of the
                    aggregate.

                  * ‘inverse()’: Remove a row from the current window.

                  * ‘finalize()’: Return the final result of the
                    aggregate as *note a type natively supported by
                    SQLite: 2d56.

               The number of arguments that the ‘step()’ and ‘value()’
               methods must accept is controlled by 'num_params'.

               Set to ‘None’ to remove an existing SQL aggregate window
               function.


          Solleva: *note NotSupportedError: 2d83. – If used with a
          version of SQLite older than 3.25.0, which does not support
          aggregate window functions.

          Added in version 3.11.

          Example:

               # Example taken from https://www.sqlite.org/windowfunctions.html#udfwinfunc
               class WindowSumInt:
                   def __init__(self):
                       self.count = 0

                   def step(self, value):
                       """Add a row to the current window."""
                       self.count += value

                   def value(self):
                       """Return the current value of the aggregate."""
                       return self.count

                   def inverse(self, value):
                       """Remove a row from the current window."""
                       self.count -= value

                   def finalize(self):
                       """Return the final value of the aggregate.

                       Any clean-up actions should be placed here.
                       """
                       return self.count


               con = sqlite3.connect(":memory:")
               cur = con.execute("CREATE TABLE test(x, y)")
               values = [
                   ("a", 4),
                   ("b", 5),
                   ("c", 3),
                   ("d", 8),
                   ("e", 1),
               ]
               cur.executemany("INSERT INTO test VALUES(?, ?)", values)
               con.create_window_function("sumint", 1, WindowSumInt)
               cur.execute("""
                   SELECT x, sumint(y) OVER (
                       ORDER BY x ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING
                   ) AS sum_y
                   FROM test ORDER BY x
               """)
               print(cur.fetchall())
               con.close()

      -- Metodo: create_collation (name, callable, /)

          Create a collation named 'name' using the collating function
          'callable'.  'callable' is passed two *note string: 169.
          arguments, and it should return an *note integer: 19b.:

             * ‘1’ if the first is ordered higher than the second

             * ‘-1’ if the first is ordered lower than the second

             * ‘0’ if they are ordered equal

          The following example shows a reverse sorting collation:

               def collate_reverse(string1, string2):
                   if string1 == string2:
                       return 0
                   elif string1 < string2:
                       return 1
                   else:
                       return -1

               con = sqlite3.connect(":memory:")
               con.create_collation("reverse", collate_reverse)

               cur = con.execute("CREATE TABLE test(x)")
               cur.executemany("INSERT INTO test(x) VALUES(?)", [("a",), ("b",)])
               cur.execute("SELECT x FROM test ORDER BY x COLLATE reverse")
               for row in cur:
                   print(row)
               con.close()

          Remove a collation function by setting 'callable' to ‘None’.

          Cambiato nella versione 3.11: The collation name can contain
          any Unicode character.  Earlier, only ASCII characters were
          allowed.

      -- Metodo: interrupt ()

          Call this method from a different thread to abort any queries
          that might be executing on the connection.  Aborted queries
          will raise an *note OperationalError: 1c3a.

      -- Metodo: set_authorizer (authorizer_callback)

          Register *note callable: 2d61. 'authorizer_callback' to be
          invoked for each attempt to access a column of a table in the
          database.  The callback should return one of *note SQLITE_OK:
          2d64, *note SQLITE_DENY: 2d65, or *note SQLITE_IGNORE: 2d66.
          to signal how access to the column should be handled by the
          underlying SQLite library.

          The first argument to the callback signifies what kind of
          operation is to be authorized.  The second and third argument
          will be arguments or ‘None’ depending on the first argument.
          The 4th argument is the name of the database («main», «temp»,
          etc.)  if applicable.  The 5th argument is the name of the
          inner-most trigger or view that is responsible for the access
          attempt or ‘None’ if this access attempt is directly from
          input SQL code.

          Please consult the SQLite documentation about the possible
          values for the first argument and the meaning of the second
          and third argument depending on the first one.  All necessary
          constants are available in the ‘sqlite3’ module.

          Passing ‘None’ as 'authorizer_callback' will disable the
          authorizer.

          Cambiato nella versione 3.11: Added support for disabling the
          authorizer using ‘None’.

          Cambiato nella versione 3.13: Passing 'authorizer_callback' as
          a keyword argument is deprecated.  The parameter will become
          positional-only in Python 3.15.

      -- Metodo: set_progress_handler (progress_handler, n)

          Register *note callable: 2d61. 'progress_handler' to be
          invoked for every 'n' instructions of the SQLite virtual
          machine.  This is useful if you want to get called from SQLite
          during long-running operations, for example to update a GUI.

          If you want to clear any previously installed progress
          handler, call the method with ‘None’ for 'progress_handler'.

          Returning a non-zero value from the handler function will
          terminate the currently executing query and cause it to raise
          a *note DatabaseError: 2d85. exception.

          Cambiato nella versione 3.13: Passing 'progress_handler' as a
          keyword argument is deprecated.  The parameter will become
          positional-only in Python 3.15.

      -- Metodo: set_trace_callback (trace_callback)

          Register *note callable: 2d61. 'trace_callback' to be invoked
          for each SQL statement that is actually executed by the SQLite
          backend.

          The only argument passed to the callback is the statement (as
          *note str: 169.) that is being executed.  The return value of
          the callback is ignored.  Note that the backend does not only
          run statements passed to the *note Cursor.execute(): 5b0.
          methods.  Other sources include the *note transaction
          management: 2d4c. of the ‘sqlite3’ module and the execution of
          triggers defined in the current database.

          Passing ‘None’ as 'trace_callback' will disable the trace
          callback.

               Nota: Exceptions raised in the trace callback are not
               propagated.  As a development and debugging aid, use
               *note enable_callback_tracebacks(): 2d5f. to enable
               printing tracebacks from exceptions raised in the trace
               callback.

          Added in version 3.3.

          Cambiato nella versione 3.13: Passing 'trace_callback' as a
          keyword argument is deprecated.  The parameter will become
          positional-only in Python 3.15.

      -- Metodo: enable_load_extension (enabled, /)

          Enable the SQLite engine to load SQLite extensions from shared
          libraries if 'enabled' is ‘True’; else, disallow loading
          SQLite extensions.  SQLite extensions can define new
          functions, aggregates or whole new virtual table
          implementations.  One well-known extension is the
          fulltext-search extension distributed with SQLite.

               Nota: The ‘sqlite3’ module is not built with loadable
               extension support by default, because some platforms
               (notably macOS) have SQLite libraries which are compiled
               without this feature.  To get loadable extension support,
               you must pass the *note
               -enable-loadable-sqlite-extensions: 214b. option to
               ‘configure’.

          Raises an *note auditing event: 1c56.
          ‘sqlite3.enable_load_extension’ with arguments ‘connection’,
          ‘enabled’.

          Added in version 3.2.

          Cambiato nella versione 3.10: Added the
          ‘sqlite3.enable_load_extension’ auditing event.

               con.enable_load_extension(True)

               # Load the fulltext search extension
               con.execute("select load_extension('./fts3.so')")

               # alternatively you can load the extension using an API call:
               # con.load_extension("./fts3.so")

               # disable extension loading again
               con.enable_load_extension(False)

               # example from SQLite wiki
               con.execute("CREATE VIRTUAL TABLE recipe USING fts3(name, ingredients)")
               con.executescript("""
                   INSERT INTO recipe (name, ingredients) VALUES('broccoli stew', 'broccoli peppers cheese tomatoes');
                   INSERT INTO recipe (name, ingredients) VALUES('pumpkin stew', 'pumpkin onions garlic celery');
                   INSERT INTO recipe (name, ingredients) VALUES('broccoli pie', 'broccoli cheese onions flour');
                   INSERT INTO recipe (name, ingredients) VALUES('pumpkin pie', 'pumpkin sugar flour butter');
                   """)
               for row in con.execute("SELECT rowid, name, ingredients FROM recipe WHERE name MATCH 'pie'"):
                   print(row)

      -- Metodo: load_extension (path, /, *, entrypoint=None)

          Load an SQLite extension from a shared library.  Enable
          extension loading with *note enable_load_extension(): a41.
          before calling this method.


          Parametri:

             * ‘path’ (*note str: 169.) – The path to the SQLite
               extension.

             * ‘entrypoint’ (*note str: 169.‘ | ’‘None’) – Entry point
               name.  If ‘None’ (the default), SQLite will come up with
               an entry point name of its own; see the SQLite docs
               Loading an Extension(2) for details.

          Raises an *note auditing event: 1c56. ‘sqlite3.load_extension’
          with arguments ‘connection’, ‘path’.

          Added in version 3.2.

          Cambiato nella versione 3.10: Added the
          ‘sqlite3.load_extension’ auditing event.

          Cambiato nella versione 3.12: Added the 'entrypoint'
          parameter.

      -- Metodo: iterdump (*, filter=None)

          Return an *note iterator: 4c9. to dump the database as SQL
          source code.  Useful when saving an in-memory database for
          later restoration.  Similar to the ‘.dump’ command in the
          ‘sqlite3’ shell.


          Parametri: ‘filter’ (*note str: 169.‘ | ’‘None’) – An optional
          ‘LIKE’ pattern for database objects to dump, e.g.  ‘prefix_%’.
          If ‘None’ (the default), all database objects will be
          included.

          Example:

               # Convert file example.db to SQL dump file dump.sql
               con = sqlite3.connect('example.db')
               with open('dump.sql', 'w') as f:
                   for line in con.iterdump():
                       f.write('%s\n' % line)
               con.close()

          Vedi anche
          ..........

          *note How to handle non-UTF-8 text encodings: 2d86.

          Cambiato nella versione 3.13: Added the 'filter' parameter.

      -- Metodo: backup (target, *, pages=-1, progress=None,
               name='main', sleep=0.250)

          Create a backup of an SQLite database.

          Works even if the database is being accessed by other clients
          or concurrently by the same connection.


          Parametri:

             * ‘target’ (*note Connection: 54e.) – The database
               connection to save the backup to.

             * ‘pages’ (*note int: 19b.) – The number of pages to copy
               at a time.  If equal to or less than ‘0’, the entire
               database is copied in a single step.  Defaults to ‘-1’.

             * ‘progress’ (*note callback: 2d82. | None) – If set to a
               *note callable: 2d61, it is invoked with three integer
               arguments for every backup iteration: the 'status' of the
               last iteration, the 'remaining' number of pages still to
               be copied, and the 'total' number of pages.  Defaults to
               ‘None’.

             * ‘name’ (*note str: 169.) – The name of the database to
               back up.  Either ‘"main"’ (the default) for the main
               database, ‘"temp"’ for the temporary database, or the
               name of a custom database as attached using the ‘ATTACH
               DATABASE’ SQL statement.

             * ‘sleep’ (*note float: 196.) – The number of seconds to
               sleep between successive attempts to back up remaining
               pages.

          Example 1, copy an existing database into another:

               def progress(status, remaining, total):
                   print(f'Copied {total-remaining} of {total} pages...')

               src = sqlite3.connect('example.db')
               dst = sqlite3.connect('backup.db')
               with dst:
                   src.backup(dst, pages=1, progress=progress)
               dst.close()
               src.close()

          Example 2, copy an existing database into a transient copy:

               src = sqlite3.connect('example.db')
               dst = sqlite3.connect(':memory:')
               src.backup(dst)
               dst.close()
               src.close()

          Added in version 3.7.

          Vedi anche
          ..........

          *note How to handle non-UTF-8 text encodings: 2d86.

      -- Metodo: getlimit (category, /)

          Get a connection runtime limit.


          Parametri: ‘category’ (*note int: 19b.) – The SQLite limit
          category(3) to be queried.


          Tipo di ritorno: *note int: 19b.


          Solleva: *note ProgrammingError: 305. – If 'category' is not
          recognised by the underlying SQLite library.

          Example, query the maximum length of an SQL statement for
          *note Connection: 54e. ‘con’ (the default is 1000000000):

               >>> con.getlimit(sqlite3.SQLITE_LIMIT_SQL_LENGTH)
               1000000000

          Added in version 3.11.

      -- Metodo: setlimit (category, limit, /)

          Set a connection runtime limit.  Attempts to increase a limit
          above its hard upper bound are silently truncated to the hard
          upper bound.  Regardless of whether or not the limit was
          changed, the prior value of the limit is returned.


          Parametri:

             * ‘category’ (*note int: 19b.) – The SQLite limit
               category(4) to be set.

             * ‘limit’ (*note int: 19b.) – The value of the new limit.
               If negative, the current limit is unchanged.


          Tipo di ritorno: *note int: 19b.


          Solleva: *note ProgrammingError: 305. – If 'category' is not
          recognised by the underlying SQLite library.

          Example, limit the number of attached databases to 1 for *note
          Connection: 54e. ‘con’ (the default limit is 10):

               >>> con.setlimit(sqlite3.SQLITE_LIMIT_ATTACHED, 1)
               10
               >>> con.getlimit(sqlite3.SQLITE_LIMIT_ATTACHED)
               1

          Added in version 3.11.

      -- Metodo: getconfig (op, /)

          Query a boolean connection configuration option.


          Parametri: ‘op’ (*note int: 19b.) – A *note SQLITE_DBCONFIG
          code: 2d69.


          Tipo di ritorno: *note bool: 3c3.

          Added in version 3.12.

      -- Metodo: setconfig (op, enable=True, /)

          Set a boolean connection configuration option.


          Parametri:

             * ‘op’ (*note int: 19b.) – A *note SQLITE_DBCONFIG code:
               2d69.

             * ‘enable’ (*note bool: 3c3.) – ‘True’ if the configuration
               option should be enabled (default); ‘False’ if it should
               be disabled.

          Added in version 3.12.

      -- Metodo: serialize (*, name='main')

          Serialize a database into a *note bytes: 192. object.  For an
          ordinary on-disk database file, the serialization is just a
          copy of the disk file.  For an in-memory database or a «temp»
          database, the serialization is the same sequence of bytes
          which would be written to disk if that database were backed up
          to disk.


          Parametri: ‘name’ (*note str: 169.) – The database name to be
          serialized.  Defaults to ‘"main"’.


          Tipo di ritorno: *note bytes: 192.

               Nota: This method is only available if the underlying
               SQLite library has the serialize API.

          Added in version 3.11.

      -- Metodo: deserialize (data, /, *, name='main')

          Deserialize a *note serialized: 88f. database into a *note
          Connection: 54e.  This method causes the database connection
          to disconnect from database 'name', and reopen 'name' as an
          in-memory database based on the serialization contained in
          'data'.


          Parametri:

             * ‘data’ (*note bytes: 192.) – A serialized database.

             * ‘name’ (*note str: 169.) – The database name to
               deserialize into.  Defaults to ‘"main"’.


          Solleva:

             * *note OperationalError: 1c3a. – If the database
               connection is currently involved in a read transaction or
               a backup operation.

             * *note DatabaseError: 2d85. – If 'data' does not contain a
               valid SQLite database.

             * *note OverflowError: a83. – If *note len(data): 841. is
               larger than ‘2**63 - 1’.

               Nota: This method is only available if the underlying
               SQLite library has the deserialize API.

          Added in version 3.11.

      -- Attributo: autocommit

          This attribute controls PEP 249(5)-compliant transaction
          behaviour.  ‘autocommit’ has three allowed values:

             * ‘False’: Select PEP 249(6)-compliant transaction
               behaviour, implying that ‘sqlite3’ ensures a transaction
               is always open.  Use *note commit(): 2d4d. and *note
               rollback(): 2d7d. to close transactions.

               This is the recommended value of ‘autocommit’.

             * ‘True’: Use SQLite’s autocommit mode(7).  *note commit():
               2d4d. and *note rollback(): 2d7d. have no effect in this
               mode.

             * *note LEGACY_TRANSACTION_CONTROL: 2d5c.: Pre-Python 3.12
               (non- PEP 249(8)-compliant) transaction control.  See
               *note isolation_level: 2d5a. for more details.

               This is currently the default value of ‘autocommit’.

          Changing ‘autocommit’ to ‘False’ will open a new transaction,
          and changing it to ‘True’ will commit any pending transaction.

          See *note Transaction control via the autocommit attribute:
          6df. for more details.

               Nota: The *note isolation_level: 2d5a. attribute has no
               effect unless *note autocommit: 6de. is *note
               LEGACY_TRANSACTION_CONTROL: 2d5c.

          Added in version 3.12.

      -- Attributo: in_transaction

          This read-only attribute corresponds to the low-level SQLite
          autocommit mode(9).

          ‘True’ if a transaction is active (there are uncommitted
          changes), ‘False’ otherwise.

          Added in version 3.2.

      -- Attributo: isolation_level

          Controls the *note legacy transaction handling mode: 2d5b. of
          ‘sqlite3’.  If set to ‘None’, transactions are never
          implicitly opened.  If set to one of ‘"DEFERRED"’,
          ‘"IMMEDIATE"’, or ‘"EXCLUSIVE"’, corresponding to the
          underlying SQLite transaction behaviour(10), *note implicit
          transaction management: 2d5b. is performed.

          If not overridden by the 'isolation_level' parameter of *note
          connect(): 5a6, the default is ‘""’, which is an alias for
          ‘"DEFERRED"’.

               Nota: Using *note autocommit: 6de. to control transaction
               handling is recommended over using ‘isolation_level’.
               ‘isolation_level’ has no effect unless *note autocommit:
               6de. is set to *note LEGACY_TRANSACTION_CONTROL: 2d5c.
               (the default).

      -- Attributo: row_factory

          The initial *note row_factory: 2d88. for *note Cursor: 2d4a.
          objects created from this connection.  Assigning to this
          attribute does not affect the ‘row_factory’ of existing
          cursors belonging to this connection, only new ones.  Is
          ‘None’ by default, meaning each row is returned as a *note
          tuple: 614.

          See *note How to create and use row factories: 2d51. for more
          details.

      -- Attributo: text_factory

          A *note callable: 2d61. that accepts a *note bytes: 192.
          parameter and returns a text representation of it.  The
          callable is invoked for SQLite values with the ‘TEXT’ data
          type.  By default, this attribute is set to *note str: 169.

          See *note How to handle non-UTF-8 text encodings: 2d86. for
          more details.

      -- Attributo: total_changes

          Return the total number of database rows that have been
          modified, inserted, or deleted since the database connection
          was opened.

   ---------- Footnotes ----------

   (1) https://sqlite.org/deterministic.html

   (2) https://www.sqlite.org/loadext.html#loading_an_extension

   (3) https://www.sqlite.org/c3ref/c_limit_attached.html

   (4) https://www.sqlite.org/c3ref/c_limit_attached.html

   (5) https://peps.python.org/pep-0249/

   (6) https://peps.python.org/pep-0249/

   (7) 
https://www.sqlite.org/lang_transaction.html#implicit_versus_explicit_transactions

   (8) https://peps.python.org/pep-0249/

   (9) 
https://www.sqlite.org/lang_transaction.html#implicit_versus_explicit_transactions

   (10) 
https://www.sqlite.org/lang_transaction.html#deferred_immediate_and_exclusive_transactions


File: python.info,  Node: Cursor objects,  Next: Row objects,  Prev: Connection objects,  Up: Reference

5.12.6.6 Cursor objects
.......................

     A ‘Cursor’ object represents a database cursor(1) which is used to
     execute SQL statements, and manage the context of a fetch
     operation.  Cursors are created using *note Connection.cursor():
     2d49, or by using any of the *note connection shortcut methods:
     2d7c.

     Cursor objects are *note iterators: 4c9, meaning that if you *note
     execute(): 5b0. a ‘SELECT’ query, you can simply iterate over the
     cursor to fetch the resulting rows:

          for row in cur.execute("SELECT t FROM data"):
              print(row)

 -- Classe: sqlite3.Cursor

     A *note Cursor: 2d4a. instance has the following attributes and
     methods.

      -- Metodo: execute (sql, parameters=(), /)

          Execute a single SQL statement, optionally binding Python
          values using *note placeholders: 5b2.


          Parametri:

             * ‘sql’ (*note str: 169.) – A single SQL statement.

             * ‘parameters’ (*note dict: 183. | *note sequence: 717.) –
               Python values to bind to placeholders in 'sql'.  A ‘dict’
               if named placeholders are used.  A sequence if unnamed
               placeholders are used.  See *note How to use placeholders
               to bind values in SQL queries: 5b2.


          Solleva: *note ProgrammingError: 305. – When 'sql' contains
          more than one SQL statement.  When *note named placeholders:
          5b2. are used and 'parameters' is a sequence instead of a
          *note dict: 183.

          If *note autocommit: 6de. is *note LEGACY_TRANSACTION_CONTROL:
          2d5c, *note isolation_level: 2d5a. is not ‘None’, 'sql' is an
          ‘INSERT’, ‘UPDATE’, ‘DELETE’, or ‘REPLACE’ statement, and
          there is no open transaction, a transaction is implicitly
          opened before executing 'sql'.

          Cambiato nella versione 3.14: *note ProgrammingError: 305. is
          emitted if *note named placeholders: 5b2. are used and
          'parameters' is a sequence instead of a *note dict: 183.

          Use *note executescript(): 2d81. to execute multiple SQL
          statements.

      -- Metodo: executemany (sql, parameters, /)

          For every item in 'parameters', repeatedly execute the *note
          parameterized: 5b2. DML (Data Manipulation Language) SQL
          statement 'sql'.

          Uses the same implicit transaction handling as *note
          execute(): 5b0.


          Parametri:

             * ‘sql’ (*note str: 169.) – A single SQL DML statement.

             * ‘parameters’ (*note iterable: 142f.) – An iterable of
               parameters to bind with the placeholders in 'sql'.  See
               *note How to use placeholders to bind values in SQL
               queries: 5b2.


          Solleva: *note ProgrammingError: 305. – When 'sql' contains
          more than one SQL statement or is not a DML statement, When
          *note named placeholders: 5b2. are used and the items in
          'parameters' are sequences instead of *note dict: 183.s.

          Example:

               rows = [
                   ("row1",),
                   ("row2",),
               ]
               # cur is an sqlite3.Cursor object
               cur.executemany("INSERT INTO data VALUES(?)", rows)

               Nota: Any resulting rows are discarded, including DML
               statements with RETURNING clauses(2).

          Cambiato nella versione 3.14: *note ProgrammingError: 305. is
          emitted if *note named placeholders: 5b2. are used and the
          items in 'parameters' are sequences instead of *note dict:
          183.s.

      -- Metodo: executescript (sql_script, /)

          Execute the SQL statements in 'sql_script'.  If the *note
          autocommit: 6de. is *note LEGACY_TRANSACTION_CONTROL: 2d5c.
          and there is a pending transaction, an implicit ‘COMMIT’
          statement is executed first.  No other implicit transaction
          control is performed; any transaction control must be added to
          'sql_script'.

          'sql_script' must be a *note string: 169.

          Example:

               # cur is an sqlite3.Cursor object
               cur.executescript("""
                   BEGIN;
                   CREATE TABLE person(firstname, lastname, age);
                   CREATE TABLE book(title, author, published);
                   CREATE TABLE publisher(name, address);
                   COMMIT;
               """)

      -- Metodo: fetchone ()

          If *note row_factory: 2d88. is ‘None’, return the next row
          query result set as a *note tuple: 614.  Else, pass it to the
          row factory and return its result.  Return ‘None’ if no more
          data is available.

      -- Metodo: fetchmany (size=cursor.arraysize)

          Return the next set of rows of a query result as a *note list:
          24d.  Return an empty list if no more rows are available.

          The number of rows to fetch per call is specified by the
          'size' parameter.  If 'size' is not given, *note arraysize:
          1790. determines the number of rows to be fetched.  If fewer
          than 'size' rows are available, as many rows as are available
          are returned.

          Note there are performance considerations involved with the
          'size' parameter.  For optimal performance, it is usually best
          to use the arraysize attribute.  If the 'size' parameter is
          used, then it is best for it to retain the same value from one
          *note fetchmany(): 178f. call to the next.

          Cambiato nella versione 3.14.1: Negative 'size' values are
          rejected by raising *note ValueError: 2ec.

      -- Metodo: fetchall ()

          Return all (remaining) rows of a query result as a *note list:
          24d.  Return an empty list if no rows are available.  Note
          that the *note arraysize: 1790. attribute can affect the
          performance of this operation.

      -- Metodo: close ()

          Close the cursor now (rather than whenever ‘__del__’ is
          called).

          The cursor will be unusable from this point forward; a *note
          ProgrammingError: 305. exception will be raised if any
          operation is attempted with the cursor.

      -- Metodo: setinputsizes (sizes, /)

          Required by the DB-API. Does nothing in ‘sqlite3’.

      -- Metodo: setoutputsize (size, column=None, /)

          Required by the DB-API. Does nothing in ‘sqlite3’.

      -- Attributo: arraysize

          Read/write attribute that controls the number of rows returned
          by *note fetchmany(): 178f.  The default value is 1 which
          means a single row would be fetched per call.

          Cambiato nella versione 3.14.1: Negative values are rejected
          by raising *note ValueError: 2ec.

      -- Attributo: connection

          Read-only attribute that provides the SQLite database *note
          Connection: 54e. belonging to the cursor.  A *note Cursor:
          2d4a. object created by calling *note con.cursor(): 2d49. will
          have a *note connection: 2d90. attribute that refers to 'con':

               >>> con = sqlite3.connect(":memory:")
               >>> cur = con.cursor()
               >>> cur.connection == con
               True
               >>> con.close()

      -- Attributo: description

          Read-only attribute that provides the column names of the last
          query.  To remain compatible with the Python DB API, it
          returns a 7-tuple for each column where the last six items of
          each tuple are ‘None’.

          It is set for ‘SELECT’ statements without any matching rows as
          well.

      -- Attributo: lastrowid

          Read-only attribute that provides the row id of the last
          inserted row.  It is only updated after successful ‘INSERT’ or
          ‘REPLACE’ statements using the *note execute(): 5b0. method.
          For other statements, after *note executemany(): 5b1. or *note
          executescript(): 2d81, or if the insertion failed, the value
          of ‘lastrowid’ is left unchanged.  The initial value of
          ‘lastrowid’ is ‘None’.

               Nota: Inserts into ‘WITHOUT ROWID’ tables are not
               recorded.

          Cambiato nella versione 3.6: Added support for the ‘REPLACE’
          statement.

      -- Attributo: rowcount

          Read-only attribute that provides the number of modified rows
          for ‘INSERT’, ‘UPDATE’, ‘DELETE’, and ‘REPLACE’ statements; is
          ‘-1’ for other statements, including CTE (Common Table
          Expression) queries.  It is only updated by the *note
          execute(): 5b0. and *note executemany(): 5b1. methods, after
          the statement has run to completion.  This means that any
          resulting rows must be fetched in order for ‘rowcount’ to be
          updated.

      -- Attributo: row_factory

          Control how a row fetched from this ‘Cursor’ is represented.
          If ‘None’, a row is represented as a *note tuple: 614.  Can be
          set to the included *note sqlite3.Row: 1073.; or a *note
          callable: 2d61. that accepts two arguments, a *note Cursor:
          2d4a. object and the ‘tuple’ of row values, and returns a
          custom object representing an SQLite row.

          Defaults to what *note Connection.row_factory: 198d. was set
          to when the ‘Cursor’ was created.  Assigning to this attribute
          does not affect *note Connection.row_factory: 198d. of the
          parent connection.

          See *note How to create and use row factories: 2d51. for more
          details.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Cursor_(databases)

   (2) https://www.sqlite.org/lang_returning.html


File: python.info,  Node: Row objects,  Next: Blob objects,  Prev: Cursor objects,  Up: Reference

5.12.6.7 Row objects
....................

 -- Classe: sqlite3.Row

     A ‘Row’ instance serves as a highly optimized *note row_factory:
     198d. for *note Connection: 54e. objects.  It supports iteration,
     equality testing, *note len(): 841, and *note mapping: 13c3. access
     by column name and index.

     Two ‘Row’ objects compare equal if they have identical column names
     and values.

     See *note How to create and use row factories: 2d51. for more
     details.

      -- Metodo: keys ()

          Return a *note list: 24d. of column names as *note strings:
          169.  Immediately after a query, it is the first member of
          each tuple in *note Cursor.description: 1893.

     Cambiato nella versione 3.5: Added support of slicing.


File: python.info,  Node: Blob objects,  Next: PrepareProtocol objects,  Prev: Row objects,  Up: Reference

5.12.6.8 Blob objects
.....................

 -- Classe: sqlite3.Blob

     Added in version 3.11.

     A *note Blob: 893. instance is a *note file-like object: 1794. that
     can read and write data in an SQLite BLOB.  Call *note len(blob):
     841. to get the size (number of bytes) of the blob.  Use indices
     and *note slices: 25ba. for direct access to the blob data.

     Use the *note Blob: 893. as a *note context manager: 1e1. to ensure
     that the blob handle is closed after use.

          con = sqlite3.connect(":memory:")
          con.execute("CREATE TABLE test(blob_col blob)")
          con.execute("INSERT INTO test(blob_col) VALUES(zeroblob(13))")

          # Write to our blob, using two write operations:
          with con.blobopen("test", "blob_col", 1) as blob:
              blob.write(b"hello, ")
              blob.write(b"world.")
              # Modify the first and last bytes of our blob
              blob[0] = ord("H")
              blob[-1] = ord("!")

          # Read the contents of our blob
          with con.blobopen("test", "blob_col", 1) as blob:
              greeting = blob.read()

          print(greeting)  # outputs "b'Hello, world!'"
          con.close()

      -- Metodo: close ()

          Close the blob.

          The blob will be unusable from this point onward.  An *note
          Error: 1c0d. (or subclass) exception will be raised if any
          further operation is attempted with the blob.

      -- Metodo: read (length=-1, /)

          Read 'length' bytes of data from the blob at the current
          offset position.  If the end of the blob is reached, the data
          up to EOF (End of File) will be returned.  When 'length' is
          not specified, or is negative, *note read(): 2d98. will read
          until the end of the blob.

      -- Metodo: write (data, /)

          Write 'data' to the blob at the current offset.  This function
          cannot change the blob length.  Writing beyond the end of the
          blob will raise *note ValueError: 2ec.

      -- Metodo: tell ()

          Return the current access position of the blob.

      -- Metodo: seek (offset, origin=os.SEEK_SET, /)

          Set the current access position of the blob to 'offset'.  The
          'origin' argument defaults to *note os.SEEK_SET: 1495.
          (absolute blob positioning).  Other values for 'origin' are
          *note os.SEEK_CUR: 1496. (seek relative to the current
          position) and *note os.SEEK_END: 1497. (seek relative to the
          blob’s end).


File: python.info,  Node: PrepareProtocol objects,  Next: Exceptions<6>,  Prev: Blob objects,  Up: Reference

5.12.6.9 PrepareProtocol objects
................................

 -- Classe: sqlite3.PrepareProtocol

     The PrepareProtocol type’s single purpose is to act as a PEP 246(1)
     style adaption protocol for objects that can *note adapt
     themselves: 2d9d. to *note native SQLite types: 2d56.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0246/


File: python.info,  Node: Exceptions<6>,  Next: SQLite and Python types,  Prev: PrepareProtocol objects,  Up: Reference

5.12.6.10 Exceptions
....................

The exception hierarchy is defined by the DB-API 2.0 ( PEP 249(1)).

 -- Eccezione: sqlite3.Warning

     This exception is not currently raised by the ‘sqlite3’ module, but
     may be raised by applications using ‘sqlite3’, for example if a
     user-defined function truncates data while inserting.  ‘Warning’ is
     a subclass of *note Exception: bcf.

 -- Eccezione: sqlite3.Error

     The base class of the other exceptions in this module.  Use this to
     catch all errors with one single *note except: 1ab. statement.
     ‘Error’ is a subclass of *note Exception: bcf.

     If the exception originated from within the SQLite library, the
     following two attributes are added to the exception:

      -- Attributo: sqlite_errorcode

          The numeric error code from the SQLite API(2)

          Added in version 3.11.

      -- Attributo: sqlite_errorname

          The symbolic name of the numeric error code from the SQLite
          API(3)

          Added in version 3.11.

 -- Eccezione: sqlite3.InterfaceError

     Exception raised for misuse of the low-level SQLite C API. In other
     words, if this exception is raised, it probably indicates a bug in
     the ‘sqlite3’ module.  ‘InterfaceError’ is a subclass of *note
     Error: 1c0d.

 -- Eccezione: sqlite3.DatabaseError

     Exception raised for errors that are related to the database.  This
     serves as the base exception for several types of database errors.
     It is only raised implicitly through the specialised subclasses.
     ‘DatabaseError’ is a subclass of *note Error: 1c0d.

 -- Eccezione: sqlite3.DataError

     Exception raised for errors caused by problems with the processed
     data, like numeric values out of range, and strings which are too
     long.  ‘DataError’ is a subclass of *note DatabaseError: 2d85.

 -- Eccezione: sqlite3.OperationalError

     Exception raised for errors that are related to the database’s
     operation, and not necessarily under the control of the programmer.
     For example, the database path is not found, or a transaction could
     not be processed.  ‘OperationalError’ is a subclass of *note
     DatabaseError: 2d85.

 -- Eccezione: sqlite3.IntegrityError

     Exception raised when the relational integrity of the database is
     affected, e.g.  a foreign key check fails.  It is a subclass of
     *note DatabaseError: 2d85.

 -- Eccezione: sqlite3.InternalError

     Exception raised when SQLite encounters an internal error.  If this
     is raised, it may indicate that there is a problem with the runtime
     SQLite library.  ‘InternalError’ is a subclass of *note
     DatabaseError: 2d85.

 -- Eccezione: sqlite3.ProgrammingError

     Exception raised for ‘sqlite3’ API programming errors, for example
     supplying the wrong number of bindings to a query, or trying to
     operate on a closed *note Connection: 54e.  ‘ProgrammingError’ is a
     subclass of *note DatabaseError: 2d85.

 -- Eccezione: sqlite3.NotSupportedError

     Exception raised in case a method or database API is not supported
     by the underlying SQLite library.  For example, setting
     'deterministic' to ‘True’ in *note create_function(): 5a7, if the
     underlying SQLite library does not support deterministic functions.
     ‘NotSupportedError’ is a subclass of *note DatabaseError: 2d85.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0249/

   (2) https://sqlite.org/rescode.html

   (3) https://sqlite.org/rescode.html


File: python.info,  Node: SQLite and Python types,  Next: Default adapters and converters deprecated,  Prev: Exceptions<6>,  Up: Reference

5.12.6.11 SQLite and Python types
.................................

SQLite natively supports the following types: ‘NULL’, ‘INTEGER’, ‘REAL’,
‘TEXT’, ‘BLOB’.

The following Python types can thus be sent to SQLite without any
problem:

Python type                         SQLite type
                                    
------------------------------------------------------
                                    
‘None’                              ‘NULL’
                                    
                                    
*note int: 19b.                     ‘INTEGER’
                                    
                                    
*note float: 196.                   ‘REAL’
                                    
                                    
*note str: 169.                     ‘TEXT’
                                    
                                    
*note bytes: 192.                   ‘BLOB’
                                    

This is how SQLite types are converted to Python types by default:

SQLite type       Python type
                  
---------------------------------------------------------------------
                  
‘NULL’            ‘None’
                  
                  
‘INTEGER’         *note int: 19b.
                  
                  
‘REAL’            *note float: 196.
                  
                  
‘TEXT’            depends on *note text_factory: 2d89,
                  *note str: 169. by default
                  
                  
‘BLOB’            *note bytes: 192.
                  

The type system of the ‘sqlite3’ module is extensible in two ways: you
can store additional Python types in an SQLite database via *note object
adapters: 2d4f, and you can let the ‘sqlite3’ module convert SQLite
types to Python types via *note converters: 2d50.


File: python.info,  Node: Default adapters and converters deprecated,  Next: Command-line interface<2>,  Prev: SQLite and Python types,  Up: Reference

5.12.6.12 Default adapters and converters (deprecated)
......................................................

     Nota: The default adapters and converters are deprecated as of
     Python 3.12.  Instead, use the *note Adapter and converter recipes:
     716. and tailor them to your needs.

The deprecated default adapters and converters consist of:

   * An adapter for *note datetime.date: 1fa. objects to *note strings:
     169. in ISO 8601(1) format.

   * An adapter for *note datetime.datetime: 4e3. objects to strings in
     ISO 8601 format.

   * A converter for *note declared: 2d50. «date» types to *note
     datetime.date: 1fa. objects.

   * A converter for declared «timestamp» types to *note
     datetime.datetime: 4e3. objects.  Fractional parts will be
     truncated to 6 digits (microsecond precision).

     Nota: The default «timestamp» converter ignores UTC offsets in the
     database and always returns a naive *note datetime.datetime: 4e3.
     object.  To preserve UTC offsets in timestamps, either leave
     converters disabled, or register an offset-aware converter with
     *note register_converter(): 2d57.

Deprecato dalla versione 3.12.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/ISO_8601


File: python.info,  Node: Command-line interface<2>,  Prev: Default adapters and converters deprecated,  Up: Reference

5.12.6.13 Command-line interface
................................

The ‘sqlite3’ module can be invoked as a script, using the interpreter’s
*note -m: 23c. switch, in order to provide a simple SQLite shell.  The
argument signature is as follows:

     python -m sqlite3 [-h] [-v] [filename] [sql]

Type ‘.quit’ or CTRL-D to exit the shell.

 -- Option: -h, --help

     Print CLI help.

 -- Option: -v, --version

     Print underlying SQLite library version.

Added in version 3.12.


File: python.info,  Node: How-to guides,  Next: Explanation,  Prev: Reference,  Up: sqlite3 — DB-API 2 0 interface for SQLite databases

5.12.6.14 How-to guides
.......................

* Menu:

* How to use placeholders to bind values in SQL queries::
* How to adapt custom Python types to SQLite values::
* How to convert SQLite values to custom Python types::
* Adapter and converter recipes::
* How to use connection shortcut methods::
* How to use the connection context manager::
* How to work with SQLite URIs::
* How to create and use row factories::
* How to handle non-UTF-8 text encodings::


File: python.info,  Node: How to use placeholders to bind values in SQL queries,  Next: How to adapt custom Python types to SQLite values,  Up: How-to guides

5.12.6.15 How to use placeholders to bind values in SQL queries
...............................................................

SQL operations usually need to use values from Python variables.
However, beware of using Python’s string operations to assemble queries,
as they are vulnerable to SQL injection attacks(1).  For example, an
attacker can simply close the single quote and inject ‘OR TRUE’ to
select all rows:

     >>> # Never do this -- insecure!
     >>> symbol = input()
     ' OR TRUE; --
     >>> sql = "SELECT * FROM stocks WHERE symbol = '%s'" % symbol
     >>> print(sql)
     SELECT * FROM stocks WHERE symbol = '' OR TRUE; --'
     >>> cur.execute(sql)

Instead, use the DB-API’s parameter substitution.  To insert a variable
into a query string, use a placeholder in the string, and substitute the
actual values into the query by providing them as a *note tuple: 614. of
values to the second argument of the cursor’s *note execute(): 5b0.
method.

An SQL statement may use one of two kinds of placeholders: question
marks (qmark style) or named placeholders (named style).  For the qmark
style, 'parameters' must be a *note sequence: 717. whose length must
match the number of placeholders, or a *note ProgrammingError: 305. is
raised.  For the named style, 'parameters' must be an instance of a
*note dict: 183. (or a subclass), which must contain keys for all named
parameters; any extra items are ignored.  Here’s an example of both
styles:

     con = sqlite3.connect(":memory:")
     cur = con.execute("CREATE TABLE lang(name, first_appeared)")

     # This is the named style used with executemany():
     data = (
         {"name": "C", "year": 1972},
         {"name": "Fortran", "year": 1957},
         {"name": "Python", "year": 1991},
         {"name": "Go", "year": 2009},
     )
     cur.executemany("INSERT INTO lang VALUES(:name, :year)", data)

     # This is the qmark style used in a SELECT query:
     params = (1972,)
     cur.execute("SELECT * FROM lang WHERE first_appeared = ?", params)
     print(cur.fetchall())
     con.close()

     Nota: PEP 249(2) numeric placeholders are 'not' supported.  If
     used, they will be interpreted as named placeholders.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/SQL_injection

   (2) https://peps.python.org/pep-0249/


File: python.info,  Node: How to adapt custom Python types to SQLite values,  Next: How to convert SQLite values to custom Python types,  Prev: How to use placeholders to bind values in SQL queries,  Up: How-to guides

5.12.6.16 How to adapt custom Python types to SQLite values
...........................................................

SQLite supports only a limited set of data types natively.  To store
custom Python types in SQLite databases, 'adapt' them to one of the
*note Python types SQLite natively understands: 2d56.

There are two ways to adapt Python objects to SQLite types: letting your
object adapt itself, or using an 'adapter callable'.  The latter will
take precedence above the former.  For a library that exports a custom
type, it may make sense to enable that type to adapt itself.  As an
application developer, it may make more sense to take direct control by
registering custom adapter functions.

* Menu:

* How to write adaptable objects::
* How to register adapter callables::


File: python.info,  Node: How to write adaptable objects,  Next: How to register adapter callables,  Up: How to adapt custom Python types to SQLite values

5.12.6.17 How to write adaptable objects
........................................

Suppose we have a ‘Point’ class that represents a pair of coordinates,
‘x’ and ‘y’, in a Cartesian coordinate system.  The coordinate pair will
be stored as a text string in the database, using a semicolon to
separate the coordinates.  This can be implemented by adding a
‘__conform__(self, protocol)’ method which returns the adapted value.
The object passed to 'protocol' will be of type *note PrepareProtocol:
1b53.

     class Point:
         def __init__(self, x, y):
             self.x, self.y = x, y

         def __conform__(self, protocol):
             if protocol is sqlite3.PrepareProtocol:
                 return f"{self.x};{self.y}"

     con = sqlite3.connect(":memory:")
     cur = con.cursor()

     cur.execute("SELECT ?", (Point(4.0, -3.2),))
     print(cur.fetchone()[0])
     con.close()


File: python.info,  Node: How to register adapter callables,  Prev: How to write adaptable objects,  Up: How to adapt custom Python types to SQLite values

5.12.6.18 How to register adapter callables
...........................................

The other possibility is to create a function that converts the Python
object to an SQLite-compatible type.  This function can then be
registered using *note register_adapter(): 2d60.

     class Point:
         def __init__(self, x, y):
             self.x, self.y = x, y

     def adapt_point(point):
         return f"{point.x};{point.y}"

     sqlite3.register_adapter(Point, adapt_point)

     con = sqlite3.connect(":memory:")
     cur = con.cursor()

     cur.execute("SELECT ?", (Point(1.0, 2.5),))
     print(cur.fetchone()[0])
     con.close()


File: python.info,  Node: How to convert SQLite values to custom Python types,  Next: Adapter and converter recipes,  Prev: How to adapt custom Python types to SQLite values,  Up: How-to guides

5.12.6.19 How to convert SQLite values to custom Python types
.............................................................

Writing an adapter lets you convert 'from' custom Python types 'to'
SQLite values.  To be able to convert 'from' SQLite values 'to' custom
Python types, we use 'converters'.

Let’s go back to the ‘Point’ class.  We stored the x and y coordinates
separated via semicolons as strings in SQLite.

First, we’ll define a converter function that accepts the string as a
parameter and constructs a ‘Point’ object from it.

     Nota: Converter functions are 'always' passed a *note bytes: 192.
     object, no matter the underlying SQLite data type.

     def convert_point(s):
         x, y = map(float, s.split(b";"))
         return Point(x, y)

We now need to tell ‘sqlite3’ when it should convert a given SQLite
value.  This is done when connecting to a database, using the
'detect_types' parameter of *note connect(): 5a6.  There are three
options:

   * Implicit: set 'detect_types' to *note PARSE_DECLTYPES: 2d58.

   * Explicit: set 'detect_types' to *note PARSE_COLNAMES: 2d59.

   * Both: set 'detect_types' to ‘sqlite3.PARSE_DECLTYPES |
     sqlite3.PARSE_COLNAMES’.  Column names take precedence over
     declared types.

The following example illustrates the implicit and explicit approaches:

     class Point:
         def __init__(self, x, y):
             self.x, self.y = x, y

         def __repr__(self):
             return f"Point({self.x}, {self.y})"

     def adapt_point(point):
         return f"{point.x};{point.y}"

     def convert_point(s):
         x, y = list(map(float, s.split(b";")))
         return Point(x, y)

     # Register the adapter and converter
     sqlite3.register_adapter(Point, adapt_point)
     sqlite3.register_converter("point", convert_point)

     # 1) Parse using declared types
     p = Point(4.0, -3.2)
     con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_DECLTYPES)
     cur = con.execute("CREATE TABLE test(p point)")

     cur.execute("INSERT INTO test(p) VALUES(?)", (p,))
     cur.execute("SELECT p FROM test")
     print("with declared types:", cur.fetchone()[0])
     cur.close()
     con.close()

     # 2) Parse using column names
     con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_COLNAMES)
     cur = con.execute("CREATE TABLE test(p)")

     cur.execute("INSERT INTO test(p) VALUES(?)", (p,))
     cur.execute('SELECT p AS "p [point]" FROM test')
     print("with column names:", cur.fetchone()[0])
     cur.close()
     con.close()


File: python.info,  Node: Adapter and converter recipes,  Next: How to use connection shortcut methods,  Prev: How to convert SQLite values to custom Python types,  Up: How-to guides

5.12.6.20 Adapter and converter recipes
.......................................

This section shows recipes for common adapters and converters.

     import datetime
     import sqlite3

     def adapt_date_iso(val):
         """Adapt datetime.date to ISO 8601 date."""
         return val.isoformat()

     def adapt_datetime_iso(val):
         """Adapt datetime.datetime to timezone-naive ISO 8601 date."""
         return val.replace(tzinfo=None).isoformat()

     def adapt_datetime_epoch(val):
         """Adapt datetime.datetime to Unix timestamp."""
         return int(val.timestamp())

     sqlite3.register_adapter(datetime.date, adapt_date_iso)
     sqlite3.register_adapter(datetime.datetime, adapt_datetime_iso)
     sqlite3.register_adapter(datetime.datetime, adapt_datetime_epoch)

     def convert_date(val):
         """Convert ISO 8601 date to datetime.date object."""
         return datetime.date.fromisoformat(val.decode())

     def convert_datetime(val):
         """Convert ISO 8601 datetime to datetime.datetime object."""
         return datetime.datetime.fromisoformat(val.decode())

     def convert_timestamp(val):
         """Convert Unix epoch timestamp to datetime.datetime object."""
         return datetime.datetime.fromtimestamp(int(val))

     sqlite3.register_converter("date", convert_date)
     sqlite3.register_converter("datetime", convert_datetime)
     sqlite3.register_converter("timestamp", convert_timestamp)


File: python.info,  Node: How to use connection shortcut methods,  Next: How to use the connection context manager,  Prev: Adapter and converter recipes,  Up: How-to guides

5.12.6.21 How to use connection shortcut methods
................................................

Using the *note execute(): 2d7e, *note executemany(): 2d7f, and *note
executescript(): 2d80. methods of the *note Connection: 54e. class, your
code can be written more concisely because you don’t have to create the
(often superfluous) *note Cursor: 2d4a. objects explicitly.  Instead,
the *note Cursor: 2d4a. objects are created implicitly and these
shortcut methods return the cursor objects.  This way, you can execute a
‘SELECT’ statement and iterate over it directly using only a single call
on the *note Connection: 54e. object.

     # Create and fill the table.
     con = sqlite3.connect(":memory:")
     con.execute("CREATE TABLE lang(name, first_appeared)")
     data = [
         ("C++", 1985),
         ("Objective-C", 1984),
     ]
     con.executemany("INSERT INTO lang(name, first_appeared) VALUES(?, ?)", data)

     # Print the table contents
     for row in con.execute("SELECT name, first_appeared FROM lang"):
         print(row)

     print("I just deleted", con.execute("DELETE FROM lang").rowcount, "rows")

     # close() is not a shortcut method and it's not called automatically;
     # the connection object should be closed manually
     con.close()


File: python.info,  Node: How to use the connection context manager,  Next: How to work with SQLite URIs,  Prev: How to use connection shortcut methods,  Up: How-to guides

5.12.6.22 How to use the connection context manager
...................................................

A *note Connection: 54e. object can be used as a context manager that
automatically commits or rolls back open transactions when leaving the
body of the context manager.  If the body of the *note with: 186.
statement finishes without exceptions, the transaction is committed.  If
this commit fails, or if the body of the ‘with’ statement raises an
uncaught exception, the transaction is rolled back.  If *note
autocommit: 6de. is ‘False’, a new transaction is implicitly opened
after committing or rolling back.

If there is no open transaction upon leaving the body of the ‘with’
statement, or if *note autocommit: 6de. is ‘True’, the context manager
does nothing.

     Nota: The context manager neither implicitly opens a new
     transaction nor closes the connection.  If you need a closing
     context manager, consider using *note contextlib.closing(): 1591.

     con = sqlite3.connect(":memory:")
     con.execute("CREATE TABLE lang(id INTEGER PRIMARY KEY, name VARCHAR UNIQUE)")

     # Successful, con.commit() is called automatically afterwards
     with con:
         con.execute("INSERT INTO lang(name) VALUES(?)", ("Python",))

     # con.rollback() is called after the with block finishes with an exception,
     # the exception is still raised and must be caught
     try:
         with con:
             con.execute("INSERT INTO lang(name) VALUES(?)", ("Python",))
     except sqlite3.IntegrityError:
         print("couldn't add Python twice")

     # Connection object used as context manager only commits or rollbacks transactions,
     # so the connection object should be closed manually
     con.close()


File: python.info,  Node: How to work with SQLite URIs,  Next: How to create and use row factories,  Prev: How to use the connection context manager,  Up: How-to guides

5.12.6.23 How to work with SQLite URIs
......................................

Some useful URI tricks include:

   * Open a database in read-only mode:

     >>> con = sqlite3.connect("file:tutorial.db?mode=ro", uri=True)
     >>> con.execute("CREATE TABLE readonly(data)")
     Traceback (most recent call last):
     OperationalError: attempt to write a readonly database
     >>> con.close()

   * Do not implicitly create a new database file if it does not already
     exist; will raise *note OperationalError: 1c3a. if unable to create
     a new file:

     >>> con = sqlite3.connect("file:nosuchdb.db?mode=rw", uri=True)
     Traceback (most recent call last):
     OperationalError: unable to open database file

   * Create a shared named in-memory database:

     db = "file:mem1?mode=memory&cache=shared"
     con1 = sqlite3.connect(db, uri=True)
     con2 = sqlite3.connect(db, uri=True)
     with con1:
         con1.execute("CREATE TABLE shared(data)")
         con1.execute("INSERT INTO shared VALUES(28)")
     res = con2.execute("SELECT data FROM shared")
     assert res.fetchone() == (28,)

     con1.close()
     con2.close()

More information about this feature, including a list of parameters, can
be found in the SQLite URI documentation(1).

   ---------- Footnotes ----------

   (1) https://www.sqlite.org/uri.html


File: python.info,  Node: How to create and use row factories,  Next: How to handle non-UTF-8 text encodings,  Prev: How to work with SQLite URIs,  Up: How-to guides

5.12.6.24 How to create and use row factories
.............................................

By default, ‘sqlite3’ represents each row as a *note tuple: 614.  If a
‘tuple’ does not suit your needs, you can use the *note sqlite3.Row:
1073. class or a custom *note row_factory: 2d88.

While ‘row_factory’ exists as an attribute both on the *note Cursor:
2d4a. and the *note Connection: 54e, it is recommended to set *note
Connection.row_factory: 198d, so all cursors created from the connection
will use the same row factory.

‘Row’ provides indexed and case-insensitive named access to columns,
with minimal memory overhead and performance impact over a ‘tuple’.  To
use ‘Row’ as a row factory, assign it to the ‘row_factory’ attribute:

     >>> con = sqlite3.connect(":memory:")
     >>> con.row_factory = sqlite3.Row

Queries now return ‘Row’ objects:

     >>> res = con.execute("SELECT 'Earth' AS name, 6378 AS radius")
     >>> row = res.fetchone()
     >>> row.keys()
     ['name', 'radius']
     >>> row[0]         # Access by index.
     'Earth'
     >>> row["name"]    # Access by name.
     'Earth'
     >>> row["RADIUS"]  # Column names are case-insensitive.
     6378
     >>> con.close()

     Nota: The ‘FROM’ clause can be omitted in the ‘SELECT’ statement,
     as in the above example.  In such cases, SQLite returns a single
     row with columns defined by expressions, e.g.  literals, with the
     given aliases ‘expr AS alias’.

You can create a custom *note row_factory: 2d88. that returns each row
as a *note dict: 183, with column names mapped to values:

     def dict_factory(cursor, row):
         fields = [column[0] for column in cursor.description]
         return {key: value for key, value in zip(fields, row)}

Using it, queries now return a ‘dict’ instead of a ‘tuple’:

     >>> con = sqlite3.connect(":memory:")
     >>> con.row_factory = dict_factory
     >>> for row in con.execute("SELECT 1 AS a, 2 AS b"):
     ...     print(row)
     {'a': 1, 'b': 2}
     >>> con.close()

The following row factory returns a *note named tuple: 85f.:

     from collections import namedtuple

     def namedtuple_factory(cursor, row):
         fields = [column[0] for column in cursor.description]
         cls = namedtuple("Row", fields)
         return cls._make(row)

‘namedtuple_factory()’ can be used as follows:

     >>> con = sqlite3.connect(":memory:")
     >>> con.row_factory = namedtuple_factory
     >>> cur = con.execute("SELECT 1 AS a, 2 AS b")
     >>> row = cur.fetchone()
     >>> row
     Row(a=1, b=2)
     >>> row[0]  # Indexed access.
     1
     >>> row.b   # Attribute access.
     2
     >>> con.close()

With some adjustments, the above recipe can be adapted to use a *note
dataclass: 4e2, or any other custom class, instead of a *note
namedtuple: 4e1.


File: python.info,  Node: How to handle non-UTF-8 text encodings,  Prev: How to create and use row factories,  Up: How-to guides

5.12.6.25 How to handle non-UTF-8 text encodings
................................................

By default, ‘sqlite3’ uses *note str: 169. to adapt SQLite values with
the ‘TEXT’ data type.  This works well for UTF-8 encoded text, but it
might fail for other encodings and invalid UTF-8.  You can use a custom
*note text_factory: 2d89. to handle such cases.

Because of SQLite’s flexible typing(1), it is not uncommon to encounter
table columns with the ‘TEXT’ data type containing non-UTF-8 encodings,
or even arbitrary data.  To demonstrate, let’s assume we have a database
with ISO-8859-2 (Latin-2) encoded text, for example a table of
Czech-English dictionary entries.  Assuming we now have a *note
Connection: 54e. instance ‘con’ connected to this database, we can
decode the Latin-2 encoded text using this *note text_factory: 2d89.:

     con.text_factory = lambda data: str(data, encoding="latin2")

For invalid UTF-8 or arbitrary data in stored in ‘TEXT’ table columns,
you can use the following technique, borrowed from the *note Unicode
HOWTO: 14ac.:

     con.text_factory = lambda data: str(data, errors="surrogateescape")

     Nota: The ‘sqlite3’ module API does not support strings containing
     surrogates.

Vedi anche
..........

*note Unicode HOWTO: 14ac.

   ---------- Footnotes ----------

   (1) https://www.sqlite.org/flextypegood.html


File: python.info,  Node: Explanation,  Prev: How-to guides,  Up: sqlite3 — DB-API 2 0 interface for SQLite databases

5.12.6.26 Explanation
.....................

* Menu:

* Transaction control::


File: python.info,  Node: Transaction control,  Up: Explanation

5.12.6.27 Transaction control
.............................

‘sqlite3’ offers multiple methods of controlling whether, when and how
database transactions are opened and closed.  *note Transaction control
via the autocommit attribute: 6df. is recommended, while *note
Transaction control via the isolation_level attribute: 2d5b. retains the
pre-Python 3.12 behaviour.

* Menu:

* Transaction control via the autocommit attribute::
* Transaction control via the isolation_level attribute::


File: python.info,  Node: Transaction control via the autocommit attribute,  Next: Transaction control via the isolation_level attribute,  Up: Transaction control

5.12.6.28 Transaction control via the ‘autocommit’ attribute
............................................................

The recommended way of controlling transaction behaviour is through the
*note Connection.autocommit: 6de. attribute, which should preferably be
set using the 'autocommit' parameter of *note connect(): 5a6.

It is suggested to set 'autocommit' to ‘False’, which implies PEP
249(1)-compliant transaction control.  This means:

   * ‘sqlite3’ ensures that a transaction is always open, so *note
     connect(): 5a6, *note Connection.commit(): 2d4d, and *note
     Connection.rollback(): 2d7d. will implicitly open a new transaction
     (immediately after closing the pending one, for the latter two).
     ‘sqlite3’ uses ‘BEGIN DEFERRED’ statements when opening
     transactions.

   * Transactions should be committed explicitly using ‘commit()’.

   * Transactions should be rolled back explicitly using ‘rollback()’.

   * An implicit rollback is performed if the database is *note close():
     54f.-ed with pending changes.

Set 'autocommit' to ‘True’ to enable SQLite’s autocommit mode(2).  In
this mode, *note Connection.commit(): 2d4d. and *note
Connection.rollback(): 2d7d. have no effect.  Note that SQLite’s
autocommit mode is distinct from the PEP 249(3)-compliant *note
Connection.autocommit: 6de. attribute; use *note
Connection.in_transaction: 2d87. to query the low-level SQLite
autocommit mode.

Set 'autocommit' to *note LEGACY_TRANSACTION_CONTROL: 2d5c. to leave
transaction control behaviour to the *note Connection.isolation_level:
2d5a. attribute.  See *note Transaction control via the isolation_level
attribute: 2d5b. for more information.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0249/

   (2) 
https://www.sqlite.org/lang_transaction.html#implicit_versus_explicit_transactions

   (3) https://peps.python.org/pep-0249/


File: python.info,  Node: Transaction control via the isolation_level attribute,  Prev: Transaction control via the autocommit attribute,  Up: Transaction control

5.12.6.29 Transaction control via the ‘isolation_level’ attribute
.................................................................

     Nota: The recommended way of controlling transactions is via the
     *note autocommit: 6de. attribute.  See *note Transaction control
     via the autocommit attribute: 6df.

If *note Connection.autocommit: 6de. is set to *note
LEGACY_TRANSACTION_CONTROL: 2d5c. (the default), transaction behaviour
is controlled using the *note Connection.isolation_level: 2d5a.
attribute.  Otherwise, ‘isolation_level’ has no effect.

If the connection attribute *note isolation_level: 2d5a. is not ‘None’,
new transactions are implicitly opened before *note execute(): 5b0. and
*note executemany(): 5b1. executes ‘INSERT’, ‘UPDATE’, ‘DELETE’, or
‘REPLACE’ statements; for other statements, no implicit transaction
handling is performed.  Use the *note commit(): 2d4d. and *note
rollback(): 2d7d. methods to respectively commit and roll back pending
transactions.  You can choose the underlying SQLite transaction
behaviour(1) — that is, whether and what type of ‘BEGIN’ statements
‘sqlite3’ implicitly executes – via the *note isolation_level: 2d5a.
attribute.

If *note isolation_level: 2d5a. is set to ‘None’, no transactions are
implicitly opened at all.  This leaves the underlying SQLite library in
autocommit mode(2), but also allows the user to perform their own
transaction handling using explicit SQL statements.  The underlying
SQLite library autocommit mode can be queried using the *note
in_transaction: 2d87. attribute.

The *note executescript(): 2d81. method implicitly commits any pending
transaction before execution of the given SQL script, regardless of the
value of *note isolation_level: 2d5a.

Cambiato nella versione 3.6: ‘sqlite3’ used to implicitly commit an open
transaction before DDL statements.  This is no longer the case.

Cambiato nella versione 3.12: The recommended way of controlling
transactions is now via the *note autocommit: 6de. attribute.

   ---------- Footnotes ----------

   (1) 
https://www.sqlite.org/lang_transaction.html#deferred_immediate_and_exclusive_transactions

   (2) 
https://www.sqlite.org/lang_transaction.html#implicit_versus_explicit_transactions


File: python.info,  Node: Data Compression and Archiving,  Next: File Formats,  Prev: Data Persistence,  Up: The Python Standard Library

5.13 Data Compression and Archiving
===================================

The modules described in this chapter support data compression with the
zlib, gzip, bzip2, lzma, and zstd algorithms, and the creation of ZIP-
and tar-format archives.  See also *note Archiving operations: 1420.
provided by the *note shutil: ca. module.

* Menu:

* The compression package::
* compression.zstd — Compression compatible with the Zstandard format: compression zstd — Compression compatible with the Zstandard format.
* zlib — Compression compatible with gzip::
* gzip — Support for gzip files::
* bz2 — Support for bzip2 compression::
* lzma — Compression using the LZMA algorithm::
* zipfile — Work with ZIP archives::
* tarfile — Read and write tar archive files::


File: python.info,  Node: The compression package,  Next: compression zstd — Compression compatible with the Zstandard format,  Up: Data Compression and Archiving

5.13.1 The ‘compression’ package
--------------------------------

Added in version 3.14.

The ‘compression’ package contains the canonical compression modules
containing interfaces to several different compression algorithms.  Some
of these modules have historically been available as separate modules;
those will continue to be available under their original names for
compatibility reasons, and will not be removed without a deprecation
cycle.  The use of modules in ‘compression’ is encouraged where
practical.

   * ‘compression.bz2’ – Re-exports *note bz2: 14.

   * ‘compression.gzip’ – Re-exports *note gzip: 6b.

   * ‘compression.lzma’ – Re-exports *note lzma: 8e.

   * ‘compression.zlib’ – Re-exports *note zlib: 139.

   * *note compression.zstd: 23. – Wrapper for the Zstandard compression
     library


File: python.info,  Node: compression zstd — Compression compatible with the Zstandard format,  Next: zlib — Compression compatible with gzip,  Prev: The compression package,  Up: Data Compression and Archiving

5.13.2 ‘compression.zstd’ — Compression compatible with the Zstandard format
----------------------------------------------------------------------------

Added in version 3.14.

'Source code:' Lib/compression/zstd/__init__.py(1)

__________________________________________________________________

This module provides classes and functions for compressing and
decompressing data using the Zstandard (or 'zstd') compression
algorithm.  The zstd manual(2) describes Zstandard as «a fast lossless
compression algorithm, targeting real-time compression scenarios at
zlib-level and better compression ratios.» Also included is a file
interface that supports reading and writing the contents of ‘.zst’ files
created by the ‘zstd’ utility, as well as raw zstd compressed streams.

The ‘compression.zstd’ module contains:

   * The *note open(): 2dc2. function and *note ZstdFile: 2dc3. class
     for reading and writing compressed files.

   * The *note ZstdCompressor: 2dc4. and *note ZstdDecompressor: 2dc5.
     classes for incremental (de)compression.

   * The *note compress(): 2dc6. and *note decompress(): 2dc7. functions
     for one-shot (de)compression.

   * The *note train_dict(): 2dc8. and *note finalize_dict(): 2dc9.
     functions and the *note ZstdDict: 2dca. class to train and manage
     Zstandard dictionaries.

   * The *note CompressionParameter: 2dcb, *note DecompressionParameter:
     2dcc, and *note Strategy: 2dcd. classes for setting advanced
     (de)compression parameters.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

* Menu:

* Exceptions: Exceptions<7>.
* Reading and writing compressed files::
* Compressing and decompressing data in memory::
* Zstandard dictionaries::
* Advanced parameter control::
* Miscellaneous: Miscellaneous<2>.
* Examples: Examples<8>.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/compression/zstd/__init__.py

   (2) https://facebook.github.io/zstd/doc/api_manual_latest.html


File: python.info,  Node: Exceptions<7>,  Next: Reading and writing compressed files,  Up: compression zstd — Compression compatible with the Zstandard format

5.13.2.1 Exceptions
...................

 -- Eccezione: compression.zstd.ZstdError

     This exception is raised when an error occurs during compression or
     decompression, or while initializing the (de)compressor state.


File: python.info,  Node: Reading and writing compressed files,  Next: Compressing and decompressing data in memory,  Prev: Exceptions<7>,  Up: compression zstd — Compression compatible with the Zstandard format

5.13.2.2 Reading and writing compressed files
.............................................

 -- Funzione: compression.zstd.open (file, /, mode='rb', *, level=None,
          options=None, zstd_dict=None, encoding=None, errors=None,
          newline=None)

     Open a Zstandard-compressed file in binary or text mode, returning
     a *note file object: 13cb.

     The 'file' argument can be either a file name (given as a *note
     str: 169, *note bytes: 192. or *note path-like: 5a1. object), in
     which case the named file is opened, or it can be an existing file
     object to read from or write to.

     The mode argument can be either ‘'rb'’ for reading (default),
     ‘'wb'’ for overwriting, ‘'ab'’ for appending, or ‘'xb'’ for
     exclusive creation.  These can equivalently be given as ‘'r'’,
     ‘'w'’, ‘'a'’, and ‘'x'’ respectively.  You may also open in text
     mode with ‘'rt'’, ‘'wt'’, ‘'at'’, and ‘'xt'’ respectively.

     When reading, the 'options' argument can be a dictionary providing
     advanced decompression parameters; see *note
     DecompressionParameter: 2dcc. for detailed information about
     supported parameters.  The 'zstd_dict' argument is a *note
     ZstdDict: 2dca. instance to be used during decompression.  When
     reading, if the 'level' argument is not None, a ‘TypeError’ will be
     raised.

     When writing, the 'options' argument can be a dictionary providing
     advanced compression parameters; see *note CompressionParameter:
     2dcb. for detailed information about supported parameters.  The
     'level' argument is the compression level to use when writing
     compressed data.  Only one of 'level' or 'options' may be non-None.
     The 'zstd_dict' argument is a *note ZstdDict: 2dca. instance to be
     used during compression.

     In binary mode, this function is equivalent to the *note ZstdFile:
     2dc3. constructor: ‘ZstdFile(file, mode, ...)’.  In this case, the
     'encoding', 'errors', and 'newline' parameters must not be
     provided.

     In text mode, a *note ZstdFile: 2dc3. object is created, and
     wrapped in an *note io.TextIOWrapper: 9c0. instance with the
     specified encoding, error handling behavior, and line endings.

 -- Classe: compression.zstd.ZstdFile (file, /, mode='rb', *,
          level=None, options=None, zstd_dict=None)

     Open a Zstandard-compressed file in binary mode.

     A *note ZstdFile: 2dc3. can wrap an already-open *note file object:
     13cb, or operate directly on a named file.  The 'file' argument
     specifies either the file object to wrap, or the name of the file
     to open (as a *note str: 169, *note bytes: 192. or *note path-like:
     5a1. object).  If wrapping an existing file object, the wrapped
     file will not be closed when the *note ZstdFile: 2dc3. is closed.

     The 'mode' argument can be either ‘'rb'’ for reading (default),
     ‘'wb'’ for overwriting, ‘'xb'’ for exclusive creation, or ‘'ab'’
     for appending.  These can equivalently be given as ‘'r'’, ‘'w'’,
     ‘'x'’ and ‘'a'’ respectively.

     If 'file' is a file object (rather than an actual file name), a
     mode of ‘'w'’ does not truncate the file, and is instead equivalent
     to ‘'a'’.

     When reading, the 'options' argument can be a dictionary providing
     advanced decompression parameters; see *note
     DecompressionParameter: 2dcc. for detailed information about
     supported parameters.  The 'zstd_dict' argument is a *note
     ZstdDict: 2dca. instance to be used during decompression.  When
     reading, if the 'level' argument is not None, a ‘TypeError’ will be
     raised.

     When writing, the 'options' argument can be a dictionary providing
     advanced compression parameters; see *note CompressionParameter:
     2dcb. for detailed information about supported parameters.  The
     'level' argument is the compression level to use when writing
     compressed data.  Only one of 'level' or 'options' may be passed.
     The 'zstd_dict' argument is a *note ZstdDict: 2dca. instance to be
     used during compression.

     ‘ZstdFile’ supports all the members specified by *note
     io.BufferedIOBase: 8a4, except for *note detach(): 2dd1. and *note
     truncate(): 1518.  Iteration and the *note with: 186. statement are
     supported.

     The following method and attributes are also provided:

      -- Metodo: peek (size=-1)

          Return buffered data without advancing the file position.  At
          least one byte of data will be returned, unless EOF has been
          reached.  The exact number of bytes returned is unspecified
          (the 'size' argument is ignored).

               Nota: While calling *note peek(): 2dd2. does not change
               the file position of the *note ZstdFile: 2dc3, it may
               change the position of the underlying file object (for
               example, if the *note ZstdFile: 2dc3. was constructed by
               passing a file object for 'file').

      -- Attributo: mode

          ‘'rb'’ for reading and ‘'wb'’ for writing.

      -- Attributo: name

          The name of the Zstandard file.  Equivalent to the *note name:
          2dd5. attribute of the underlying *note file object: 13cb.


File: python.info,  Node: Compressing and decompressing data in memory,  Next: Zstandard dictionaries,  Prev: Reading and writing compressed files,  Up: compression zstd — Compression compatible with the Zstandard format

5.13.2.3 Compressing and decompressing data in memory
.....................................................

 -- Funzione: compression.zstd.compress (data, level=None, options=None,
          zstd_dict=None)

     Compress 'data' (a *note bytes-like object: 193.), returning the
     compressed data as a *note bytes: 192. object.

     The 'level' argument is an integer controlling the level of
     compression.  'level' is an alternative to setting *note
     CompressionParameter.compression_level: 2dd7. in 'options'.  Use
     *note bounds(): 2dd8. on *note compression_level: 2dd7. to get the
     values that can be passed for 'level'.  If advanced compression
     options are needed, the 'level' argument must be omitted and in the
     'options' dictionary the ‘CompressionParameter.compression_level’
     parameter should be set.

     The 'options' argument is a Python dictionary containing advanced
     compression parameters.  The valid keys and values for compression
     parameters are documented as part of the *note
     CompressionParameter: 2dcb. documentation.

     The 'zstd_dict' argument is an instance of *note ZstdDict: 2dca.
     containing trained data to improve compression efficiency.  The
     function *note train_dict(): 2dc8. can be used to generate a
     Zstandard dictionary.

 -- Funzione: compression.zstd.decompress (data, zstd_dict=None,
          options=None)

     Decompress 'data' (a *note bytes-like object: 193.), returning the
     uncompressed data as a *note bytes: 192. object.

     The 'options' argument is a Python dictionary containing advanced
     decompression parameters.  The valid keys and values for
     compression parameters are documented as part of the *note
     DecompressionParameter: 2dcc. documentation.

     The 'zstd_dict' argument is an instance of *note ZstdDict: 2dca.
     containing trained data used during compression.  This must be the
     same Zstandard dictionary used during compression.

     If 'data' is the concatenation of multiple distinct compressed
     frames, decompress all of these frames, and return the
     concatenation of the results.

 -- Classe: compression.zstd.ZstdCompressor (level=None, options=None,
          zstd_dict=None)

     Create a compressor object, which can be used to compress data
     incrementally.

     For a more convenient way of compressing a single chunk of data,
     see the module-level function *note compress(): 2dc6.

     The 'level' argument is an integer controlling the level of
     compression.  'level' is an alternative to setting *note
     CompressionParameter.compression_level: 2dd7. in 'options'.  Use
     *note bounds(): 2dd8. on *note compression_level: 2dd7. to get the
     values that can be passed for 'level'.  If advanced compression
     options are needed, the 'level' argument must be omitted and in the
     'options' dictionary the ‘CompressionParameter.compression_level’
     parameter should be set.

     The 'options' argument is a Python dictionary containing advanced
     compression parameters.  The valid keys and values for compression
     parameters are documented as part of the *note
     CompressionParameter: 2dcb. documentation.

     The 'zstd_dict' argument is an optional instance of *note ZstdDict:
     2dca. containing trained data to improve compression efficiency.
     The function *note train_dict(): 2dc8. can be used to generate a
     Zstandard dictionary.

      -- Metodo: compress (data, mode=ZstdCompressor.CONTINUE)

          Compress 'data' (a *note bytes-like object: 193.), returning a
          *note bytes: 192. object with compressed data if possible, or
          otherwise an empty ‘bytes’ object.  Some of 'data' may be
          buffered internally, for use in later calls to ‘compress()’
          and *note flush(): 2dda.  The returned data should be
          concatenated with the output of any previous calls to *note
          compress(): 2dd9.

          The 'mode' argument is a *note ZstdCompressor: 2dc4.
          attribute, either *note CONTINUE: 2ddb, *note FLUSH_BLOCK:
          2ddc, or *note FLUSH_FRAME: 2ddd.

          When all data has been provided to the compressor, call the
          *note flush(): 2dda. method to finish the compression process.
          If *note compress(): 2dd9. is called with 'mode' set to *note
          FLUSH_FRAME: 2ddd, *note flush(): 2dda. should not be called,
          as it would write out a new empty frame.

      -- Metodo: flush (mode=ZstdCompressor.FLUSH_FRAME)

          Finish the compression process, returning a *note bytes: 192.
          object containing any data stored in the compressor’s internal
          buffers.

          The 'mode' argument is a *note ZstdCompressor: 2dc4.
          attribute, either *note FLUSH_BLOCK: 2ddc, or *note
          FLUSH_FRAME: 2ddd.

      -- Metodo: set_pledged_input_size (size)

          Specify the amount of uncompressed data 'size' that will be
          provided for the next frame.  'size' will be written into the
          frame header of the next frame unless *note
          CompressionParameter.content_size_flag: 2ddf. is ‘False’ or
          ‘0’.  A size of ‘0’ means that the frame is empty.  If 'size'
          is ‘None’, the frame header will omit the frame size.  Frames
          that include the uncompressed data size require less memory to
          decompress, especially at higher compression levels.

          If *note last_mode: 2de0. is not *note FLUSH_FRAME: 2ddd, a
          *note ValueError: 2ec. is raised as the compressor is not at
          the start of a frame.  If the pledged size does not match the
          actual size of data provided to *note compress(): 2dd9, future
          calls to ‘compress()’ or *note flush(): 2dda. may raise *note
          ZstdError: 2dcf. and the last chunk of data may be lost.

          After *note flush(): 2dda. or *note compress(): 2dd9. are
          called with mode *note FLUSH_FRAME: 2ddd, the next frame will
          not include the frame size into the header unless
          ‘set_pledged_input_size()’ is called again.

      -- Attributo: CONTINUE

          Collect more data for compression, which may or may not
          generate output immediately.  This mode optimizes the
          compression ratio by maximizing the amount of data per block
          and frame.

      -- Attributo: FLUSH_BLOCK

          Complete and write a block to the data stream.  The data
          returned so far can be immediately decompressed.  Past data
          can still be referenced in future blocks generated by calls to
          *note compress(): 2dd9, improving compression.

      -- Attributo: FLUSH_FRAME

          Complete and write out a frame.  Future data provided to *note
          compress(): 2dd9. will be written into a new frame and
          'cannot' reference past data.

      -- Attributo: last_mode

          The last mode passed to either *note compress(): 2dd9. or
          *note flush(): 2dda.  The value can be one of *note CONTINUE:
          2ddb, *note FLUSH_BLOCK: 2ddc, or *note FLUSH_FRAME: 2ddd.
          The initial value is *note FLUSH_FRAME: 2ddd, signifying that
          the compressor is at the start of a new frame.

 -- Classe: compression.zstd.ZstdDecompressor (zstd_dict=None,
          options=None)

     Create a decompressor object, which can be used to decompress data
     incrementally.

     For a more convenient way of decompressing an entire compressed
     stream at once, see the module-level function *note decompress():
     2dc7.

     The 'options' argument is a Python dictionary containing advanced
     decompression parameters.  The valid keys and values for
     compression parameters are documented as part of the *note
     DecompressionParameter: 2dcc. documentation.

     The 'zstd_dict' argument is an instance of *note ZstdDict: 2dca.
     containing trained data used during compression.  This must be the
     same Zstandard dictionary used during compression.

          Nota: This class does not transparently handle inputs
          containing multiple compressed frames, unlike the *note
          decompress(): 2dc7. function and *note ZstdFile: 2dc3. class.
          To decompress a multi-frame input, you should use *note
          decompress(): 2dc7, *note ZstdFile: 2dc3. if working with a
          *note file object: 13cb, or multiple ‘ZstdDecompressor’
          instances.

      -- Metodo: decompress (data, max_length=-1)

          Decompress 'data' (a *note bytes-like object: 193.), returning
          uncompressed data as bytes.  Some of 'data' may be buffered
          internally, for use in later calls to ‘decompress()’.  The
          returned data should be concatenated with the output of any
          previous calls to ‘decompress()’.

          If 'max_length' is non-negative, the method returns at most
          'max_length' bytes of decompressed data.  If this limit is
          reached and further output can be produced, the *note
          needs_input: 2de2. attribute will be set to ‘False’.  In this
          case, the next call to *note decompress(): 2de1. may provide
          'data' as ‘b''’ to obtain more of the output.

          If all of the input data was decompressed and returned (either
          because this was less than 'max_length' bytes, or because
          'max_length' was negative), the *note needs_input: 2de2.
          attribute will be set to ‘True’.

          Attempting to decompress data after the end of a frame will
          raise a *note ZstdError: 2dcf.  Any data found after the end
          of the frame is ignored and saved in the *note unused_data:
          2de3. attribute.

      -- Attributo: eof

          ‘True’ if the end-of-stream marker has been reached.

      -- Attributo: unused_data

          Data found after the end of the compressed stream.

          Before the end of the stream is reached, this will be ‘b''’.

      -- Attributo: needs_input

          ‘False’ if the *note decompress(): 2de1. method can provide
          more decompressed data before requiring new compressed input.


File: python.info,  Node: Zstandard dictionaries,  Next: Advanced parameter control,  Prev: Compressing and decompressing data in memory,  Up: compression zstd — Compression compatible with the Zstandard format

5.13.2.4 Zstandard dictionaries
...............................

 -- Funzione: compression.zstd.train_dict (samples, dict_size)

     Train a Zstandard dictionary, returning a *note ZstdDict: 2dca.
     instance.  Zstandard dictionaries enable more efficient compression
     of smaller sizes of data, which is traditionally difficult to
     compress due to less repetition.  If you are compressing multiple
     similar groups of data (such as similar files), Zstandard
     dictionaries can improve compression ratios and speed
     significantly.

     The 'samples' argument (an iterable of *note bytes: 192. objects),
     is the population of samples used to train the Zstandard
     dictionary.

     The 'dict_size' argument, an integer, is the maximum size (in
     bytes) the Zstandard dictionary should be.  The Zstandard
     documentation suggests an absolute maximum of no more than 100 KB,
     but the maximum can often be smaller depending on the data.  Larger
     dictionaries generally slow down compression, but improve
     compression ratios.  Smaller dictionaries lead to faster
     compression, but reduce the compression ratio.

 -- Funzione: compression.zstd.finalize_dict (zstd_dict, /, samples,
          dict_size, level)

     An advanced function for converting a «raw content» Zstandard
     dictionary into a regular Zstandard dictionary.  «Raw content»
     dictionaries are a sequence of bytes that do not need to follow the
     structure of a normal Zstandard dictionary.

     The 'zstd_dict' argument is a *note ZstdDict: 2dca. instance with
     the *note dict_content: 2de6. containing the raw dictionary
     contents.

     The 'samples' argument (an iterable of *note bytes: 192. objects),
     contains sample data for generating the Zstandard dictionary.

     The 'dict_size' argument, an integer, is the maximum size (in
     bytes) the Zstandard dictionary should be.  See *note train_dict():
     2dc8. for suggestions on the maximum dictionary size.

     The 'level' argument (an integer) is the compression level expected
     to be passed to the compressors using this dictionary.  The
     dictionary information varies for each compression level, so tuning
     for the proper compression level can make compression more
     efficient.

 -- Classe: compression.zstd.ZstdDict (dict_content, /, *, is_raw=False)

     A wrapper around Zstandard dictionaries.  Dictionaries can be used
     to improve the compression of many small chunks of data.  Use *note
     train_dict(): 2dc8. if you need to train a new dictionary from
     sample data.

     The 'dict_content' argument (a *note bytes-like object: 193.), is
     the already trained dictionary information.

     The 'is_raw' argument, a boolean, is an advanced parameter
     controlling the meaning of 'dict_content'.  ‘True’ means
     'dict_content' is a «raw content» dictionary, without any format
     restrictions.  ‘False’ means 'dict_content' is an ordinary
     Zstandard dictionary, created from Zstandard functions, for
     example, *note train_dict(): 2dc8. or the external ‘zstd’ CLI.

     When passing a ‘ZstdDict’ to a function, the ‘as_digested_dict’ and
     ‘as_undigested_dict’ attributes can control how the dictionary is
     loaded by passing them as the ‘zstd_dict’ argument, for example,
     ‘compress(data, zstd_dict=zd.as_digested_dict)’.  Digesting a
     dictionary is a costly operation that occurs when loading a
     Zstandard dictionary.  When making multiple calls to compression or
     decompression, passing a digested dictionary will reduce the
     overhead of loading the dictionary.

          Difference for compression

                         Digested           Undigested
                         dictionary         dictionary
                                            
          -------------------------------------------------
                                            
          Advanced       ‘window_log’,      None
          parameters     ‘hash_log’,        
          of the         ‘chain_log’,
          compressor     ‘search_log’,
          which may be   ‘min_match’,
          overridden     ‘target_length’,
          by the         ‘strategy’,
          dictionary’s   ‘enable_long_distance_matching’,
          parameters     ‘ldm_hash_log’,
                         ‘ldm_min_match’,
                         ‘ldm_bucket_size_log’,
                         ‘ldm_hash_rate_log’,
                         and some
                         non-public
                         parameters.
                         
                                            
          ‘ZstdDict’     Yes.  It’s         No.  If you
          internally     faster when        wish to load
          caches the     loading a          an
          dictionary     digested           undigested
                         dictionary again   dictionary
                         with the same      multiple
                         compression        times,
                         level.             consider
                                            reusing a
                                            compressor
                                            object.
                                            

     If passing a ‘ZstdDict’ without any attribute, an undigested
     dictionary is passed by default when compressing and a digested
     dictionary is generated if necessary and passed by default when
     decompressing.

           -- Attributo: dict_content

               The content of the Zstandard dictionary, a ‘bytes’
               object.  It’s the same as the 'dict_content' argument in
               the ‘__init__’ method.  It can be used with other
               programs, such as the ‘zstd’ CLI program.

           -- Attributo: dict_id

               Identifier of the Zstandard dictionary, a non-negative
               int value.

               Non-zero means the dictionary is ordinary, created by
               Zstandard functions and following the Zstandard format.

               ‘0’ means a «raw content» dictionary, free of any format
               restriction, used for advanced users.

                    Nota: The meaning of ‘0’ for ‘ZstdDict.dict_id’ is
                    different from the ‘dictionary_id’ attribute to the
                    *note get_frame_info(): 2de8. function.

           -- Attributo: as_digested_dict

               Load as a digested dictionary.

           -- Attributo: as_undigested_dict

               Load as an undigested dictionary.


File: python.info,  Node: Advanced parameter control,  Next: Miscellaneous<2>,  Prev: Zstandard dictionaries,  Up: compression zstd — Compression compatible with the Zstandard format

5.13.2.5 Advanced parameter control
...................................

 -- Classe: compression.zstd.CompressionParameter

     An *note IntEnum: edd. containing the advanced compression
     parameter keys that can be used when compressing data.

     The *note bounds(): 2dd8. method can be used on any attribute to
     get the valid values for that parameter.

     Parameters are optional; any omitted parameter will have it’s value
     selected automatically.

     Example getting the lower and upper bound of *note
     compression_level: 2dd7.:

          lower, upper = CompressionParameter.compression_level.bounds()

     Example setting the *note window_log: 2dec. to the maximum size:

          _lower, upper = CompressionParameter.window_log.bounds()
          options = {CompressionParameter.window_log: upper}
          compress(b'venezuelan beaver cheese', options=options)

      -- Metodo: bounds ()

          Return the tuple of int bounds, ‘(lower, upper)’, of a
          compression parameter.  This method should be called on the
          attribute you wish to retrieve the bounds of.  For example, to
          get the valid values for *note compression_level: 2dd7, one
          may check the result of
          ‘CompressionParameter.compression_level.bounds()’.

          Both the lower and upper bounds are inclusive.

      -- Attributo: compression_level

          A high-level means of setting other compression parameters
          that affect the speed and ratio of compressing data.

          Regular compression levels are greater than ‘0’.  Values
          greater than ‘20’ are considered «ultra» compression and
          require more memory than other levels.  Negative values can be
          used to trade off faster compression for worse compression
          ratios.

          Setting the level to zero uses *note
          COMPRESSION_LEVEL_DEFAULT: 2ded.

      -- Attributo: window_log

          Maximum allowed back-reference distance the compressor can use
          when compressing data, expressed as power of two, ‘1 <<
          window_log’ bytes.  This parameter greatly influences the
          memory usage of compression.  Higher values require more
          memory but gain better compression values.

          A value of zero causes the value to be selected automatically.

      -- Attributo: hash_log

          Size of the initial probe table, as a power of two.  The
          resulting memory usage is ‘1 << (hash_log+2)’ bytes.  Larger
          tables improve compression ratio of strategies <= *note dfast:
          2def, and improve compression speed of strategies > *note
          dfast: 2def.

          A value of zero causes the value to be selected automatically.

      -- Attributo: chain_log

          Size of the multi-probe search table, as a power of two.  The
          resulting memory usage is ‘1 << (chain_log+2)’ bytes.  Larger
          tables result in better and slower compression.  This
          parameter has no effect for the *note fast: 2df1. strategy.
          It’s still useful when using *note dfast: 2def. strategy, in
          which case it defines a secondary probe table.

          A value of zero causes the value to be selected automatically.

      -- Attributo: search_log

          Number of search attempts, as a power of two.  More attempts
          result in better and slower compression.  This parameter is
          useless for *note fast: 2df1. and *note dfast: 2def.
          strategies.

          A value of zero causes the value to be selected automatically.

      -- Attributo: min_match

          Minimum size of searched matches.  Larger values increase
          compression and decompression speed, but decrease ratio.  Note
          that Zstandard can still find matches of smaller size, it just
          tweaks its search algorithm to look for this size and larger.
          For all strategies < *note btopt: 2df4, the effective minimum
          is ‘4’; for all strategies > *note fast: 2df1, the effective
          maximum is ‘6’.

          A value of zero causes the value to be selected automatically.

      -- Attributo: target_length

          The impact of this field depends on the selected *note
          Strategy: 2dcd.

          For strategies *note btopt: 2df4, *note btultra: 2df6. and
          *note btultra2: 2df7, the value is the length of a match
          considered «good enough» to stop searching.  Larger values
          make compression ratios better, but compresses slower.

          For strategy *note fast: 2df1, it is the distance between
          match sampling.  Larger values make compression faster, but
          with a worse compression ratio.

          A value of zero causes the value to be selected automatically.

      -- Attributo: strategy

          The higher the value of selected strategy, the more complex
          the compression technique used by zstd, resulting in higher
          compression ratios but slower compression.

          Vedi anche
          ..........

          *note Strategy: 2dcd.

      -- Attributo: enable_long_distance_matching

          Long distance matching can be used to improve compression for
          large inputs by finding large matches at greater distances.
          It increases memory usage and window size.

          ‘True’ or ‘1’ enable long distance matching while ‘False’ or
          ‘0’ disable it.

          Enabling this parameter increases default *note window_log:
          2dec. to 128 MiB except when expressly set to a different
          value.  This setting is enabled by default if ‘window_log’ >=
          128 MiB and the compression strategy >= *note btopt: 2df4.
          (compression level 16+).

      -- Attributo: ldm_hash_log

          Size of the table for long distance matching, as a power of
          two.  Larger values increase memory usage and compression
          ratio, but decrease compression speed.

          A value of zero causes the value to be selected automatically.

      -- Attributo: ldm_min_match

          Minimum match size for long distance matcher.  Larger or too
          small values can often decrease the compression ratio.

          A value of zero causes the value to be selected automatically.

      -- Attributo: ldm_bucket_size_log

          Log size of each bucket in the long distance matcher hash
          table for collision resolution.  Larger values improve
          collision resolution but decrease compression speed.

          A value of zero causes the value to be selected automatically.

      -- Attributo: ldm_hash_rate_log

          Frequency of inserting/looking up entries into the long
          distance matcher hash table.  Larger values improve
          compression speed.  Deviating far from the default value will
          likely result in a compression ratio decrease.

          A value of zero causes the value to be selected automatically.

      -- Attributo: content_size_flag

          Write the size of the data to be compressed into the Zstandard
          frame header when known prior to compressing.

          This flag only takes effect under the following scenarios:

             * Calling *note compress(): 2dc6. for one-shot compression

             * Providing all of the data to be compressed in the frame
               in a single *note ZstdCompressor.compress(): 2dd9. call,
               with the *note ZstdCompressor.FLUSH_FRAME: 2ddd. mode.

             * Calling *note ZstdCompressor.set_pledged_input_size():
               2dde. with the exact amount of data that will be provided
               to the compressor prior to any calls to *note
               ZstdCompressor.compress(): 2dd9. for the current frame.
               ‘ZstdCompressor.set_pledged_input_size()’ must be called
               for each new frame.

          All other compression calls may not write the size information
          into the frame header.

          ‘True’ or ‘1’ enable the content size flag while ‘False’ or
          ‘0’ disable it.

      -- Attributo: checksum_flag

          A four-byte checksum using XXHash64 of the uncompressed
          content is written at the end of each frame.  Zstandard’s
          decompression code verifies the checksum.  If there is a
          mismatch a *note ZstdError: 2dcf. exception is raised.

          ‘True’ or ‘1’ enable checksum generation while ‘False’ or ‘0’
          disable it.

      -- Attributo: dict_id_flag

          When compressing with a *note ZstdDict: 2dca, the dictionary’s
          ID is written into the frame header.

          ‘True’ or ‘1’ enable storing the dictionary ID while ‘False’
          or ‘0’ disable it.

      -- Attributo: nb_workers

          Select how many threads will be spawned to compress in
          parallel.  When ‘nb_workers’ > 0, enables multi-threaded
          compression, a value of ‘1’ means «one-thread multi-threaded
          mode».  More workers improve speed, but also increase memory
          usage and slightly reduce compression ratio.

          A value of zero disables multi-threading.

      -- Attributo: job_size

          Size of a compression job, in bytes.  This value is enforced
          only when *note nb_workers: 2e00. >= 1.  Each compression job
          is completed in parallel, so this value can indirectly impact
          the number of active threads.

          A value of zero causes the value to be selected automatically.

      -- Attributo: overlap_log

          Sets how much data is reloaded from previous jobs (threads)
          for new jobs to be used by the look behind window during
          compression.  This value is only used when *note nb_workers:
          2e00. >= 1.  Acceptable values vary from 0 to 9.

                  * 0 means dynamically set the overlap amount

                  * 1 means no overlap

                  * 9 means use a full window size from the previous job

          Each increment halves/doubles the overlap size.  «8» means an
          overlap of ‘window_size/2’, «7» means an overlap of
          ‘window_size/4’, etc.

 -- Classe: compression.zstd.DecompressionParameter

     An *note IntEnum: edd. containing the advanced decompression
     parameter keys that can be used when decompressing data.
     Parameters are optional; any omitted parameter will have it’s value
     selected automatically.

     The *note bounds(): 2e03. method can be used on any attribute to
     get the valid values for that parameter.

     Example setting the *note window_log_max: 2e04. to the maximum
     size:

          data = compress(b'Some very long buffer of bytes...')

          _lower, upper = DecompressionParameter.window_log_max.bounds()

          options = {DecompressionParameter.window_log_max: upper}
          decompress(data, options=options)

      -- Metodo: bounds ()

          Return the tuple of int bounds, ‘(lower, upper)’, of a
          decompression parameter.  This method should be called on the
          attribute you wish to retrieve the bounds of.

          Both the lower and upper bounds are inclusive.

      -- Attributo: window_log_max

          The base-two logarithm of the maximum size of the window used
          during decompression.  This can be useful to limit the amount
          of memory used when decompressing data.  A larger maximum
          window size leads to faster decompression.

          A value of zero causes the value to be selected automatically.

 -- Classe: compression.zstd.Strategy

     An *note IntEnum: edd. containing strategies for compression.
     Higher-numbered strategies correspond to more complex and slower
     compression.

          Nota: The values of attributes of ‘Strategy’ are not
          necessarily stable across zstd versions.  Only the ordering of
          the attributes may be relied upon.  The attributes are listed
          below in order.

     The following strategies are available:

      -- Attributo: fast

      -- Attributo: dfast

      -- Attributo: greedy

      -- Attributo: lazy

      -- Attributo: lazy2

      -- Attributo: btlazy2

      -- Attributo: btopt

      -- Attributo: btultra

      -- Attributo: btultra2


File: python.info,  Node: Miscellaneous<2>,  Next: Examples<8>,  Prev: Advanced parameter control,  Up: compression zstd — Compression compatible with the Zstandard format

5.13.2.6 Miscellaneous
......................

 -- Funzione: compression.zstd.get_frame_info (frame_buffer)

     Retrieve a *note FrameInfo: 2e0a. object containing metadata about
     a Zstandard frame.  Frames contain metadata related to the
     compressed data they hold.

 -- Classe: compression.zstd.FrameInfo

     Metadata related to a Zstandard frame.

      -- Attributo: decompressed_size

          The size of the decompressed contents of the frame.

      -- Attributo: dictionary_id

          An integer representing the Zstandard dictionary ID needed for
          decompressing the frame.  ‘0’ means the dictionary ID was not
          recorded in the frame header.  This may mean that a Zstandard
          dictionary is not needed, or that the ID of a required
          dictionary was not recorded.

 -- Attributo: compression.zstd.COMPRESSION_LEVEL_DEFAULT

     The default compression level for Zstandard: ‘3’.

 -- Attributo: compression.zstd.zstd_version_info

     Version number of the runtime zstd library as a tuple of integers
     (major, minor, release).


File: python.info,  Node: Examples<8>,  Prev: Miscellaneous<2>,  Up: compression zstd — Compression compatible with the Zstandard format

5.13.2.7 Examples
.................

Reading in a compressed file:

     from compression import zstd

     with zstd.open("file.zst") as f:
         file_content = f.read()

Creating a compressed file:

     from compression import zstd

     data = b"Insert Data Here"
     with zstd.open("file.zst", "w") as f:
         f.write(data)

Compressing data in memory:

     from compression import zstd

     data_in = b"Insert Data Here"
     data_out = zstd.compress(data_in)

Incremental compression:

     from compression import zstd

     comp = zstd.ZstdCompressor()
     out1 = comp.compress(b"Some data\n")
     out2 = comp.compress(b"Another piece of data\n")
     out3 = comp.compress(b"Even more data\n")
     out4 = comp.flush()
     # Concatenate all the partial results:
     result = b"".join([out1, out2, out3, out4])

Writing compressed data to an already-open file:

     from compression import zstd

     with open("myfile", "wb") as f:
         f.write(b"This data will not be compressed\n")
         with zstd.open(f, "w") as zstf:
             zstf.write(b"This *will* be compressed\n")
         f.write(b"Not compressed\n")

Creating a compressed file using compression parameters:

     from compression import zstd

     options = {
        zstd.CompressionParameter.checksum_flag: 1
     }
     with zstd.open("file.zst", "w", options=options) as f:
         f.write(b"Mind if I squeeze in?")


File: python.info,  Node: zlib — Compression compatible with gzip,  Next: gzip — Support for gzip files,  Prev: compression zstd — Compression compatible with the Zstandard format,  Up: Data Compression and Archiving

5.13.3 ‘zlib’ — Compression compatible with ‘gzip’
--------------------------------------------------

__________________________________________________________________

For applications that require data compression, the functions in this
module allow compression and decompression, using the zlib library(1).

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

zlib’s functions have many options and often need to be used in a
particular order.  This documentation doesn’t attempt to cover all of
the permutations; consult the zlib manual(2) for authoritative
information.

For reading and writing ‘.gz’ files see the *note gzip: 6b. module.

The available exception and functions in this module are:

 -- Eccezione: zlib.error

     Exception raised on compression and decompression errors.

 -- Funzione: zlib.adler32 (data[, value])

     Computes an Adler-32 checksum of 'data'.  (An Adler-32 checksum is
     almost as reliable as a CRC32 but can be computed much more
     quickly.)  The result is an unsigned 32-bit integer.  If 'value' is
     present, it is used as the starting value of the checksum;
     otherwise, a default value of 1 is used.  Passing in 'value' allows
     computing a running checksum over the concatenation of several
     inputs.  The algorithm is not cryptographically strong, and should
     not be used for authentication or digital signatures.  Since the
     algorithm is designed for use as a checksum algorithm, it is not
     suitable for use as a general hash algorithm.

     Cambiato nella versione 3.0: The result is always unsigned.

 -- Funzione: zlib.compress (data, /, level=Z_DEFAULT_COMPRESSION,
          wbits=MAX_WBITS)

     Compresses the bytes in 'data', returning a bytes object containing
     compressed data.  'level' is an integer from ‘0’ to ‘9’ or ‘-1’
     controlling the level of compression; See *note Z_BEST_SPEED: 2e13.
     (‘1’), *note Z_BEST_COMPRESSION: 2e14. (‘9’), *note
     Z_NO_COMPRESSION: 2e15. (‘0’), and the default, *note
     Z_DEFAULT_COMPRESSION: 2e16. (‘-1’) for more information about
     these values.  The 'wbits' argument controls the size of the
     history buffer (or the «window size») used when compressing data,
     and whether a header and trailer is included in the output.  It can
     take several ranges of values, defaulting to ‘15’ (*note MAX_WBITS:
     2e18.):

        * +9 to +15: The base-two logarithm of the window size, which
          therefore ranges between 512 and 32768.  Larger values produce
          better compression at the expense of greater memory usage.
          The resulting output will include a zlib-specific header and
          trailer.

        * −9 to −15: Uses the absolute value of 'wbits' as the window
          size logarithm, while producing a raw output stream with no
          header or trailing checksum.

        * +25 to +31 = 16 + (9 to 15): Uses the low 4 bits of the value
          as the window size logarithm, while including a basic ‘gzip’
          header and trailing checksum in the output.

     Raises the *note error: 2e12. exception if any error occurs.

     Cambiato nella versione 3.6: 'level' can now be used as a keyword
     parameter.

     Cambiato nella versione 3.11: The 'wbits' parameter is now
     available to set window bits and compression type.

 -- Funzione: zlib.compressobj (level=Z_DEFAULT_COMPRESSION,
          method=DEFLATED, wbits=MAX_WBITS, memLevel=DEF_MEM_LEVEL,
          strategy=Z_DEFAULT_STRATEGY[, zdict])

     Returns a compression object, to be used for compressing data
     streams that won’t fit into memory at once.

     'level' is the compression level – an integer from ‘0’ to ‘9’ or
     ‘-1’.  See *note Z_BEST_SPEED: 2e13. (‘1’), *note
     Z_BEST_COMPRESSION: 2e14. (‘9’), *note Z_NO_COMPRESSION: 2e15.
     (‘0’), and the default, *note Z_DEFAULT_COMPRESSION: 2e16. (‘-1’)
     for more information about these values.

     'method' is the compression algorithm.  Currently, the only
     supported value is *note DEFLATED: 2e1a.

     The 'wbits' parameter controls the size of the history buffer (or
     the «window size»), and what header and trailer format will be
     used.  It has the same meaning as *note described for compress():
     2e17.

     The 'memLevel' argument controls the amount of memory used for the
     internal compression state.  Valid values range from ‘1’ to ‘9’.
     Higher values use more memory, but are faster and produce smaller
     output.

     'strategy' is used to tune the compression algorithm.  Possible
     values are *note Z_DEFAULT_STRATEGY: 2e1b, *note Z_FILTERED: 2e1c,
     *note Z_HUFFMAN_ONLY: 2e1d, *note Z_RLE: 2e1e. and *note Z_FIXED:
     2e1f.

     'zdict' is a predefined compression dictionary.  This is a sequence
     of bytes (such as a *note bytes: 192. object) containing
     subsequences that are expected to occur frequently in the data that
     is to be compressed.  Those subsequences that are expected to be
     most common should come at the end of the dictionary.

     Cambiato nella versione 3.3: Added the 'zdict' parameter and
     keyword argument support.

 -- Funzione: zlib.crc32 (data[, value])

     Computes a CRC (Cyclic Redundancy Check) checksum of 'data'.  The
     result is an unsigned 32-bit integer.  If 'value' is present, it is
     used as the starting value of the checksum; otherwise, a default
     value of 0 is used.  Passing in 'value' allows computing a running
     checksum over the concatenation of several inputs.  The algorithm
     is not cryptographically strong, and should not be used for
     authentication or digital signatures.  Since the algorithm is
     designed for use as a checksum algorithm, it is not suitable for
     use as a general hash algorithm.

     Cambiato nella versione 3.0: The result is always unsigned.

 -- Funzione: zlib.decompress (data, /, wbits=MAX_WBITS,
          bufsize=DEF_BUF_SIZE)

     Decompresses the bytes in 'data', returning a bytes object
     containing the uncompressed data.  The 'wbits' parameter depends on
     the format of 'data', and is discussed further below.  If 'bufsize'
     is given, it is used as the initial size of the output buffer.
     Raises the *note error: 2e12. exception if any error occurs.  The
     'wbits' parameter controls the size of the history buffer (or
     «window size»), and what header and trailer format is expected.  It
     is similar to the parameter for *note compressobj(): 2e19, but
     accepts more ranges of values:

        * +8 to +15: The base-two logarithm of the window size.  The
          input must include a zlib header and trailer.

        * 0: Automatically determine the window size from the zlib
          header.  Only supported since zlib 1.2.3.5.

        * −8 to −15: Uses the absolute value of 'wbits' as the window
          size logarithm.  The input must be a raw stream with no header
          or trailer.

        * +24 to +31 = 16 + (8 to 15): Uses the low 4 bits of the value
          as the window size logarithm.  The input must include a gzip
          header and trailer.

        * +40 to +47 = 32 + (8 to 15): Uses the low 4 bits of the value
          as the window size logarithm, and automatically accepts either
          the zlib or gzip format.

     When decompressing a stream, the window size must not be smaller
     than the size originally used to compress the stream; using a
     too-small value may result in an *note error: 2e12. exception.  The
     default 'wbits' value corresponds to the largest window size and
     requires a zlib header and trailer to be included.

     'bufsize' is the initial size of the buffer used to hold
     decompressed data.  If more space is required, the buffer size will
     be increased as needed, so you don’t have to get this value exactly
     right; tuning it will only save a few calls to ‘malloc()’.

     Cambiato nella versione 3.6: 'wbits' and 'bufsize' can be used as
     keyword arguments.

 -- Funzione: zlib.decompressobj (wbits=MAX_WBITS[, zdict])

     Returns a decompression object, to be used for decompressing data
     streams that won’t fit into memory at once.

     The 'wbits' parameter controls the size of the history buffer (or
     the «window size»), and what header and trailer format is expected.
     It has the same meaning as *note described for decompress(): 2e20.

     The 'zdict' parameter specifies a predefined compression
     dictionary.  If provided, this must be the same dictionary as was
     used by the compressor that produced the data that is to be
     decompressed.

          Nota: If 'zdict' is a mutable object (such as a *note
          bytearray: 344.), you must not modify its contents between the
          call to *note decompressobj(): 2e21. and the first call to the
          decompressor’s ‘decompress()’ method.

     Cambiato nella versione 3.3: Added the 'zdict' parameter.

Compression objects support the following methods:

 -- Metodo: Compress.compress (data)

     Compress 'data', returning a bytes object containing compressed
     data for at least part of the data in 'data'.  This data should be
     concatenated to the output produced by any preceding calls to the
     *note compress(): 850. method.  Some input may be kept in internal
     buffers for later processing.

 -- Metodo: Compress.flush ([mode])

     All pending input is processed, and a bytes object containing the
     remaining compressed output is returned.  'mode' can be selected
     from the constants *note Z_NO_FLUSH: 2e24, *note Z_PARTIAL_FLUSH:
     2e25, *note Z_SYNC_FLUSH: 2e26, *note Z_FULL_FLUSH: 2e27, *note
     Z_BLOCK: 2e28, or *note Z_FINISH: 2e29, defaulting to *note
     Z_FINISH: 2e29.  Except *note Z_FINISH: 2e29, all constants allow
     compressing further bytestrings of data, while *note Z_FINISH:
     2e29. finishes the compressed stream and prevents compressing any
     more data.  After calling *note flush(): 2e23. with 'mode' set to
     *note Z_FINISH: 2e29, the *note compress(): 850. method cannot be
     called again; the only realistic action is to delete the object.

 -- Metodo: Compress.copy ()

     Returns a copy of the compression object.  This can be used to
     efficiently compress a set of data that share a common initial
     prefix.

Cambiato nella versione 3.8: Added *note copy.copy(): 758. and *note
copy.deepcopy(): d67. support to compression objects.

Decompression objects support the following methods and attributes:

 -- Attributo: Decompress.unused_data

     A bytes object which contains any bytes past the end of the
     compressed data.  That is, this remains ‘b""’ until the last byte
     that contains compression data is available.  If the whole
     bytestring turned out to contain compressed data, this is ‘b""’, an
     empty bytes object.

 -- Attributo: Decompress.unconsumed_tail

     A bytes object that contains any data that was not consumed by the
     last *note decompress(): f0b. call because it exceeded the limit
     for the uncompressed data buffer.  This data has not yet been seen
     by the zlib machinery, so you must feed it (possibly with further
     data concatenated to it) back to a subsequent *note decompress():
     f0b. method call in order to get correct output.

 -- Attributo: Decompress.eof

     A boolean indicating whether the end of the compressed data stream
     has been reached.

     This makes it possible to distinguish between a properly formed
     compressed stream, and an incomplete or truncated one.

     Added in version 3.3.

 -- Metodo: Decompress.decompress (data, max_length=0)

     Decompress 'data', returning a bytes object containing the
     uncompressed data corresponding to at least part of the data in
     'string'.  This data should be concatenated to the output produced
     by any preceding calls to the *note decompress(): f0b. method.
     Some of the input data may be preserved in internal buffers for
     later processing.

     If the optional parameter 'max_length' is non-zero then the return
     value will be no longer than 'max_length'.  This may mean that not
     all of the compressed input can be processed; and unconsumed data
     will be stored in the attribute *note unconsumed_tail: 2e2c.  This
     bytestring must be passed to a subsequent call to *note
     decompress(): f0b. if decompression is to continue.  If
     'max_length' is zero then the whole input is decompressed, and
     *note unconsumed_tail: 2e2c. is empty.

     Cambiato nella versione 3.6: 'max_length' can be used as a keyword
     argument.

 -- Metodo: Decompress.flush ([length])

     All pending input is processed, and a bytes object containing the
     remaining uncompressed output is returned.  After calling *note
     flush(): 2e2e, the *note decompress(): f0b. method cannot be called
     again; the only realistic action is to delete the object.

     The optional parameter 'length' sets the initial size of the output
     buffer.

 -- Metodo: Decompress.copy ()

     Returns a copy of the decompression object.  This can be used to
     save the state of the decompressor midway through the data stream
     in order to speed up random seeks into the stream at a future
     point.

Cambiato nella versione 3.8: Added *note copy.copy(): 758. and *note
copy.deepcopy(): d67. support to decompression objects.

The following constants are available to configure compression and
decompression behavior:

 -- Dati: zlib.DEFLATED

     The deflate compression method.

 -- Dati: zlib.MAX_WBITS

     The maximum window size, expressed as a power of 2.  For example,
     if ‘MAX_WBITS’ is ‘15’ it results in a window size of ‘32 KiB’.

 -- Dati: zlib.DEF_MEM_LEVEL

     The default memory level for compression objects.

 -- Dati: zlib.DEF_BUF_SIZE

     The default buffer size for decompression operations.

 -- Dati: zlib.Z_NO_COMPRESSION

     Compression level ‘0’; no compression.

     Added in version 3.6.

 -- Dati: zlib.Z_BEST_SPEED

     Compression level ‘1’; fastest and produces the least compression.

 -- Dati: zlib.Z_BEST_COMPRESSION

     Compression level ‘9’; slowest and produces the most compression.

 -- Dati: zlib.Z_DEFAULT_COMPRESSION

     Default compression level (‘-1’); a compromise between speed and
     compression.  Currently equivalent to compression level ‘6’.

 -- Dati: zlib.Z_DEFAULT_STRATEGY

     Default compression strategy, for normal data.

 -- Dati: zlib.Z_FILTERED

     Compression strategy for data produced by a filter (or predictor).

 -- Dati: zlib.Z_HUFFMAN_ONLY

     Compression strategy that forces Huffman coding only.

 -- Dati: zlib.Z_RLE

     Compression strategy that limits match distances to one (run-length
     encoding).

     This constant is only available if Python was compiled with zlib
     1.2.0.1 or greater.

     Added in version 3.6.

 -- Dati: zlib.Z_FIXED

     Compression strategy that prevents the use of dynamic Huffman
     codes.

     This constant is only available if Python was compiled with zlib
     1.2.2.2 or greater.

     Added in version 3.6.

 -- Dati: zlib.Z_NO_FLUSH

     Flush mode ‘0’.  No special flushing behavior.

     Added in version 3.6.

 -- Dati: zlib.Z_PARTIAL_FLUSH

     Flush mode ‘1’.  Flush as much output as possible.

 -- Dati: zlib.Z_SYNC_FLUSH

     Flush mode ‘2’.  All output is flushed and the output is aligned to
     a byte boundary.

 -- Dati: zlib.Z_FULL_FLUSH

     Flush mode ‘3’.  All output is flushed and the compression state is
     reset.

 -- Dati: zlib.Z_FINISH

     Flush mode ‘4’.  All pending input is processed, no more input is
     expected.

 -- Dati: zlib.Z_BLOCK

     Flush mode ‘5’.  A deflate block is completed and emitted.

     This constant is only available if Python was compiled with zlib
     1.2.2.2 or greater.

     Added in version 3.6.

 -- Dati: zlib.Z_TREES

     Flush mode ‘6’, for inflate operations.  Instructs inflate to
     return when it gets to the next deflate block boundary.

     This constant is only available if Python was compiled with zlib
     1.2.3.4 or greater.

     Added in version 3.6.

Information about the version of the zlib library in use is available
through the following constants:

 -- Dati: zlib.ZLIB_VERSION

     The version string of the zlib library that was used for building
     the module.  This may be different from the zlib library actually
     used at runtime, which is available as *note ZLIB_RUNTIME_VERSION:
     1376.

 -- Dati: zlib.ZLIB_RUNTIME_VERSION

     The version string of the zlib library actually loaded by the
     interpreter.

     Added in version 3.3.

 -- Dati: zlib.ZLIBNG_VERSION

     The version string of the zlib-ng library that was used for
     building the module if zlib-ng was used.  When present, the *note
     ZLIB_VERSION: 2e33. and *note ZLIB_RUNTIME_VERSION: 1376. constants
     reflect the version of the zlib API provided by zlib-ng.

     If zlib-ng was not used to build the module, this constant will be
     absent.

     Added in version 3.14.

Vedi anche
..........

Module *note gzip: 6b.

     Reading and writing ‘gzip’-format files.

‘https://www.zlib.net’

     The zlib library home page.

‘https://www.zlib.net/manual.html’

     The zlib manual explains the semantics and usage of the library’s
     many functions.

In case gzip (de)compression is a bottleneck, the python-isal(3) package
speeds up (de)compression with a mostly compatible API.

   ---------- Footnotes ----------

   (1) https://www.zlib.net

   (2) https://www.zlib.net/manual.html

   (3) https://github.com/pycompression/python-isal


File: python.info,  Node: gzip — Support for gzip files,  Next: bz2 — Support for bzip2 compression,  Prev: zlib — Compression compatible with gzip,  Up: Data Compression and Archiving

5.13.4 ‘gzip’ — Support for ‘gzip’ files
----------------------------------------

'Source code:' Lib/gzip.py(1)

__________________________________________________________________

This module provides a simple interface to compress and decompress files
just like the GNU programs ‘gzip’ and ‘gunzip’ would.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

The data compression is provided by the *note zlib: 139. module.

The *note gzip: 6b. module provides the *note GzipFile: 65c. class, as
well as the *note open(): 2e38, *note compress(): 84f. and *note
decompress(): 1415. convenience functions.  The *note GzipFile: 65c.
class reads and writes ‘gzip’-format files, automatically compressing or
decompressing the data so that it looks like an ordinary *note file
object: 13cb.

Note that additional file formats which can be decompressed by the
‘gzip’ and ‘gunzip’ programs, such as those produced by ‘compress’ and
‘pack’, are not supported by this module.

The module defines the following items:

 -- Funzione: gzip.open (filename, mode='rb', compresslevel=9,
          encoding=None, errors=None, newline=None)

     Open a gzip-compressed file in binary or text mode, returning a
     *note file object: 13cb.

     The 'filename' argument can be an actual filename (a *note str:
     169. or *note bytes: 192. object), or an existing file object to
     read from or write to.

     The 'mode' argument can be any of ‘'r'’, ‘'rb'’, ‘'a'’, ‘'ab'’,
     ‘'w'’, ‘'wb'’, ‘'x'’ or ‘'xb'’ for binary mode, or ‘'rt'’, ‘'at'’,
     ‘'wt'’, or ‘'xt'’ for text mode.  The default is ‘'rb'’.

     The 'compresslevel' argument is an integer from 0 to 9, as for the
     *note GzipFile: 65c. constructor.

     For binary mode, this function is equivalent to the *note GzipFile:
     65c. constructor: ‘GzipFile(filename, mode, compresslevel)’.  In
     this case, the 'encoding', 'errors' and 'newline' arguments must
     not be provided.

     For text mode, a *note GzipFile: 65c. object is created, and
     wrapped in an *note io.TextIOWrapper: 9c0. instance with the
     specified encoding, error handling behavior, and line ending(s).

     Cambiato nella versione 3.3: Added support for 'filename' being a
     file object, support for text mode, and the 'encoding', 'errors'
     and 'newline' arguments.

     Cambiato nella versione 3.4: Added support for the ‘'x'’, ‘'xb'’
     and ‘'xt'’ modes.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Eccezione: gzip.BadGzipFile

     An exception raised for invalid gzip files.  It inherits from *note
     OSError: 2c0.  *note EOFError: 14e1. and *note zlib.error: 2e12.
     can also be raised for invalid gzip files.

     Added in version 3.8.

 -- Classe: gzip.GzipFile (filename=None, mode=None, compresslevel=9,
          fileobj=None, mtime=None)

     Constructor for the *note GzipFile: 65c. class, which simulates
     most of the methods of a *note file object: 13cb, with the
     exception of the *note truncate(): 1518. method.  At least one of
     'fileobj' and 'filename' must be given a non-trivial value.

     The new class instance is based on 'fileobj', which can be a
     regular file, an *note io.BytesIO: 10a6. object, or any other
     object which simulates a file.  It defaults to ‘None’, in which
     case 'filename' is opened to provide a file object.

     When 'fileobj' is not ‘None’, the 'filename' argument is only used
     to be included in the ‘gzip’ file header, which may include the
     original filename of the uncompressed file.  It defaults to the
     filename of 'fileobj', if discernible; otherwise, it defaults to
     the empty string, and in this case the original filename is not
     included in the header.

     The 'mode' argument can be any of ‘'r'’, ‘'rb'’, ‘'a'’, ‘'ab'’,
     ‘'w'’, ‘'wb'’, ‘'x'’, or ‘'xb'’, depending on whether the file will
     be read or written.  The default is the mode of 'fileobj' if
     discernible; otherwise, the default is ‘'rb'’.  In future Python
     releases the mode of 'fileobj' will not be used.  It is better to
     always specify 'mode' for writing.

     Note that the file is always opened in binary mode.  To open a
     compressed file in text mode, use *note open(): 2e38. (or wrap your
     *note GzipFile: 65c. with an *note io.TextIOWrapper: 9c0.).

     The 'compresslevel' argument is an integer from ‘0’ to ‘9’
     controlling the level of compression; ‘1’ is fastest and produces
     the least compression, and ‘9’ is slowest and produces the most
     compression.  ‘0’ is no compression.  The default is ‘9’.

     The optional 'mtime' argument is the timestamp requested by gzip.
     The time is in Unix format, i.e., seconds since 00:00:00 UTC,
     January 1, 1970.  If 'mtime' is omitted or ‘None’, the current time
     is used.  Use 'mtime' = 0 to generate a compressed stream that does
     not depend on creation time.

     See below for the *note mtime: 2e39. attribute that is set when
     decompressing.

     Calling a *note GzipFile: 65c. object’s ‘close()’ method does not
     close 'fileobj', since you might wish to append more material after
     the compressed data.  This also allows you to pass an *note
     io.BytesIO: 10a6. object opened for writing as 'fileobj', and
     retrieve the resulting memory buffer using the *note io.BytesIO:
     10a6. object’s *note getvalue(): 2e3a. method.

     *note GzipFile: 65c. supports the *note io.BufferedIOBase: 8a4.
     interface, including iteration and the *note with: 186. statement.
     Only the *note truncate(): 1518. method isn’t implemented.

     *note GzipFile: 65c. also provides the following method and
     attribute:

      -- Metodo: peek (n)

          Read 'n' uncompressed bytes without advancing the file
          position.  The number of bytes returned may be more or less
          than requested.

               Nota: While calling *note peek(): 1414. does not change
               the file position of the *note GzipFile: 65c, it may
               change the position of the underlying file object (e.g.
               if the *note GzipFile: 65c. was constructed with the
               'fileobj' parameter).

          Added in version 3.2.

      -- Attributo: mode

          ‘'rb'’ for reading and ‘'wb'’ for writing.

          Cambiato nella versione 3.13: In previous versions it was an
          integer ‘1’ or ‘2’.

      -- Attributo: mtime

          When decompressing, this attribute is set to the last
          timestamp in the most recently read header.  It is an integer,
          holding the number of seconds since the Unix epoch (00:00:00
          UTC, January 1, 1970).  The initial value before reading any
          headers is ‘None’.

      -- Attributo: name

          The path to the gzip file on disk, as a *note str: 169. or
          *note bytes: 192.  Equivalent to the output of *note
          os.fspath(): e4f. on the original input path, with no other
          normalization, resolution or expansion.

     Cambiato nella versione 3.1: Support for the *note with: 186.
     statement was added, along with the 'mtime' constructor argument
     and *note mtime: 2e39. attribute.

     Cambiato nella versione 3.2: Support for zero-padded and unseekable
     files was added.

     Cambiato nella versione 3.3: The *note io.BufferedIOBase.read1():
     2e3c. method is now implemented.

     Cambiato nella versione 3.4: Added support for the ‘'x'’ and ‘'xb'’
     modes.

     Cambiato nella versione 3.5: Added support for writing arbitrary
     *note bytes-like objects: 193.  The *note read(): 1530. method now
     accepts an argument of ‘None’.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Deprecato dalla versione 3.9: Opening *note GzipFile: 65c. for
     writing without specifying the 'mode' argument is deprecated.

     Cambiato nella versione 3.12: Remove the ‘filename’ attribute, use
     the *note name: 732. attribute instead.

 -- Funzione: gzip.compress (data, compresslevel=9, *, mtime=0)

     Compress the 'data', returning a *note bytes: 192. object
     containing the compressed data.  'compresslevel' and 'mtime' have
     the same meaning as in the *note GzipFile: 65c. constructor above,
     but 'mtime' defaults to 0 for reproducible output.

     Added in version 3.2.

     Cambiato nella versione 3.8: Added the 'mtime' parameter for
     reproducible output.

     Cambiato nella versione 3.11: Speed is improved by compressing all
     data at once instead of in a streamed fashion.  Calls with 'mtime'
     set to ‘0’ are delegated to *note zlib.compress(): 850. for better
     speed.  In this situation the output may contain a gzip header «OS»
     byte value other than 255 «unknown» as supplied by the underlying
     zlib implementation.

     Cambiato nella versione 3.13: The gzip header OS byte is guaranteed
     to be set to 255 when this function is used as was the case in 3.10
     and earlier.

     Cambiato nella versione 3.14: The 'mtime' parameter now defaults to
     0 for reproducible output.  For the previous behaviour of using the
     current time, pass ‘None’ to 'mtime'.

 -- Funzione: gzip.decompress (data)

     Decompress the 'data', returning a *note bytes: 192. object
     containing the uncompressed data.  This function is capable of
     decompressing multi-member gzip data (multiple gzip blocks
     concatenated together).  When the data is certain to contain only
     one member the *note zlib.decompress(): f0b. function with 'wbits'
     set to 31 is faster.

     Added in version 3.2.

     Cambiato nella versione 3.11: Speed is improved by decompressing
     members at once in memory instead of in a streamed fashion.

* Menu:

* Examples of usage::
* Command-line interface: Command-line interface<3>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/gzip.py


File: python.info,  Node: Examples of usage,  Next: Command-line interface<3>,  Up: gzip — Support for gzip files

5.13.4.1 Examples of usage
..........................

Example of how to read a compressed file:

     import gzip
     with gzip.open('/home/joe/file.txt.gz', 'rb') as f:
         file_content = f.read()

Example of how to create a compressed GZIP file:

     import gzip
     content = b"Lots of content here"
     with gzip.open('/home/joe/file.txt.gz', 'wb') as f:
         f.write(content)

Example of how to GZIP compress an existing file:

     import gzip
     import shutil
     with open('/home/joe/file.txt', 'rb') as f_in:
         with gzip.open('/home/joe/file.txt.gz', 'wb') as f_out:
             shutil.copyfileobj(f_in, f_out)

Example of how to GZIP compress a binary string:

     import gzip
     s_in = b"Lots of content here"
     s_out = gzip.compress(s_in)

Vedi anche
..........

Module *note zlib: 139.

     The basic data compression module needed to support the ‘gzip’ file
     format.

In case gzip (de)compression is a bottleneck, the python-isal(1) package
speeds up (de)compression with a mostly compatible API.

   ---------- Footnotes ----------

   (1) https://github.com/pycompression/python-isal


File: python.info,  Node: Command-line interface<3>,  Prev: Examples of usage,  Up: gzip — Support for gzip files

5.13.4.2 Command-line interface
...............................

The *note gzip: 6b. module provides a simple command line interface to
compress or decompress files.

Once executed the *note gzip: 6b. module keeps the input file(s).

Cambiato nella versione 3.8: Add a new command line interface with a
usage.  By default, when you will execute the CLI, the default
compression level is 6.

* Menu:

* Command-line options::


File: python.info,  Node: Command-line options,  Up: Command-line interface<3>

5.13.4.3 Command-line options
.............................

 -- Option: file

     If 'file' is not specified, read from *note sys.stdin: 760.

 -- Option: --fast

     Indicates the fastest compression method (less compression).

 -- Option: --best

     Indicates the slowest compression method (best compression).

 -- Option: -d, --decompress

     Decompress the given file.

 -- Option: -h, --help

     Show the help message.


File: python.info,  Node: bz2 — Support for bzip2 compression,  Next: lzma — Compression using the LZMA algorithm,  Prev: gzip — Support for gzip files,  Up: Data Compression and Archiving

5.13.5 ‘bz2’ — Support for ‘bzip2’ compression
----------------------------------------------

'Source code:' Lib/bz2.py(1)

__________________________________________________________________

This module provides a comprehensive interface for compressing and
decompressing data using the bzip2 compression algorithm.

The *note bz2: 14. module contains:

   * The *note open(): 1295. function and *note BZ2File: a68. class for
     reading and writing compressed files.

   * The *note BZ2Compressor: 1ab6. and *note BZ2Decompressor: 1ab4.
     classes for incremental (de)compression.

   * The *note compress(): 2861. and *note decompress(): 1296. functions
     for one-shot (de)compression.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

* Menu:

* (De)compression of files: De compression of files.
* Incremental (de)compression: Incremental de compression.
* One-shot (de)compression: One-shot de compression.
* Examples of usage: Examples of usage<2>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/bz2.py


File: python.info,  Node: De compression of files,  Next: Incremental de compression,  Up: bz2 — Support for bzip2 compression

5.13.5.1 (De)compression of files
.................................

 -- Funzione: bz2.open (filename, mode='rb', compresslevel=9,
          encoding=None, errors=None, newline=None)

     Open a bzip2-compressed file in binary or text mode, returning a
     *note file object: 13cb.

     As with the constructor for *note BZ2File: a68, the 'filename'
     argument can be an actual filename (a *note str: 169. or *note
     bytes: 192. object), or an existing file object to read from or
     write to.

     The 'mode' argument can be any of ‘'r'’, ‘'rb'’, ‘'w'’, ‘'wb'’,
     ‘'x'’, ‘'xb'’, ‘'a'’ or ‘'ab'’ for binary mode, or ‘'rt'’, ‘'wt'’,
     ‘'xt'’, or ‘'at'’ for text mode.  The default is ‘'rb'’.

     The 'compresslevel' argument is an integer from 1 to 9, as for the
     *note BZ2File: a68. constructor.

     For binary mode, this function is equivalent to the *note BZ2File:
     a68. constructor: ‘BZ2File(filename, mode,
     compresslevel=compresslevel)’.  In this case, the 'encoding',
     'errors' and 'newline' arguments must not be provided.

     For text mode, a *note BZ2File: a68. object is created, and wrapped
     in an *note io.TextIOWrapper: 9c0. instance with the specified
     encoding, error handling behavior, and line ending(s).

     Added in version 3.3.

     Cambiato nella versione 3.4: The ‘'x'’ (exclusive creation) mode
     was added.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Classe: bz2.BZ2File (filename, mode='r', *, compresslevel=9)

     Open a bzip2-compressed file in binary mode.

     If 'filename' is a *note str: 169. or *note bytes: 192. object,
     open the named file directly.  Otherwise, 'filename' should be a
     *note file object: 13cb, which will be used to read or write the
     compressed data.

     The 'mode' argument can be either ‘'r'’ for reading (default),
     ‘'w'’ for overwriting, ‘'x'’ for exclusive creation, or ‘'a'’ for
     appending.  These can equivalently be given as ‘'rb'’, ‘'wb'’,
     ‘'xb'’ and ‘'ab'’ respectively.

     If 'filename' is a file object (rather than an actual file name), a
     mode of ‘'w'’ does not truncate the file, and is instead equivalent
     to ‘'a'’.

     If 'mode' is ‘'w'’ or ‘'a'’, 'compresslevel' can be an integer
     between ‘1’ and ‘9’ specifying the level of compression: ‘1’
     produces the least compression, and ‘9’ (default) produces the most
     compression.

     If 'mode' is ‘'r'’, the input file may be the concatenation of
     multiple compressed streams.

     *note BZ2File: a68. provides all of the members specified by the
     *note io.BufferedIOBase: 8a4, except for *note detach(): 2dd1. and
     *note truncate(): 1518.  Iteration and the *note with: 186.
     statement are supported.

     *note BZ2File: a68. also provides the following methods and
     attributes:

      -- Metodo: peek ([n])

          Return buffered data without advancing the file position.  At
          least one byte of data will be returned (unless at EOF). The
          exact number of bytes returned is unspecified.

               Nota: While calling *note peek(): 2e4d. does not change
               the file position of the *note BZ2File: a68, it may
               change the position of the underlying file object (e.g.
               if the *note BZ2File: a68. was constructed by passing a
               file object for 'filename').

          Added in version 3.3.

      -- Metodo: fileno ()

          Return the file descriptor for the underlying file.

          Added in version 3.3.

      -- Metodo: readable ()

          Return whether the file was opened for reading.

          Added in version 3.3.

      -- Metodo: seekable ()

          Return whether the file supports seeking.

          Added in version 3.3.

      -- Metodo: writable ()

          Return whether the file was opened for writing.

          Added in version 3.3.

      -- Metodo: read1 (size=-1)

          Read up to 'size' uncompressed bytes, while trying to avoid
          making multiple reads from the underlying stream.  Reads up to
          a buffer’s worth of data if size is negative.

          Returns ‘b''’ if the file is at EOF.

          Added in version 3.3.

      -- Metodo: readinto (b)

          Read bytes into 'b'.

          Returns the number of bytes read (0 for EOF).

          Added in version 3.3.

      -- Attributo: mode

          ‘'rb'’ for reading and ‘'wb'’ for writing.

          Added in version 3.13.

      -- Attributo: name

          The bzip2 file name.  Equivalent to the *note name: 2dd5.
          attribute of the underlying *note file object: 13cb.

          Added in version 3.13.

     Cambiato nella versione 3.1: Support for the *note with: 186.
     statement was added.

     Cambiato nella versione 3.3: Support was added for 'filename' being
     a *note file object: 13cb. instead of an actual filename.

     The ‘'a'’ (append) mode was added, along with support for reading
     multi-stream files.

     Cambiato nella versione 3.4: The ‘'x'’ (exclusive creation) mode
     was added.

     Cambiato nella versione 3.5: The *note read(): 1530. method now
     accepts an argument of ‘None’.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.9: The 'buffering' parameter has been
     removed.  It was ignored and deprecated since Python 3.0.  Pass an
     open file object to control how the file is opened.

     The 'compresslevel' parameter became keyword-only.

     Cambiato nella versione 3.10: This class is thread unsafe in the
     face of multiple simultaneous readers or writers, just like its
     equivalent classes in *note gzip: 6b. and *note lzma: 8e. have
     always been.


File: python.info,  Node: Incremental de compression,  Next: One-shot de compression,  Prev: De compression of files,  Up: bz2 — Support for bzip2 compression

5.13.5.2 Incremental (de)compression
....................................

 -- Classe: bz2.BZ2Compressor (compresslevel=9)

     Create a new compressor object.  This object may be used to
     compress data incrementally.  For one-shot compression, use the
     *note compress(): 2861. function instead.

     'compresslevel', if given, must be an integer between ‘1’ and ‘9’.
     The default is ‘9’.

      -- Metodo: compress (data)

          Provide data to the compressor object.  Returns a chunk of
          compressed data if possible, or an empty byte string
          otherwise.

          When you have finished providing data to the compressor, call
          the *note flush(): 2e58. method to finish the compression
          process.

      -- Metodo: flush ()

          Finish the compression process.  Returns the compressed data
          left in internal buffers.

          The compressor object may not be used after this method has
          been called.

 -- Classe: bz2.BZ2Decompressor

     Create a new decompressor object.  This object may be used to
     decompress data incrementally.  For one-shot compression, use the
     *note decompress(): 1296. function instead.

          Nota: This class does not transparently handle inputs
          containing multiple compressed streams, unlike *note
          decompress(): 1296. and *note BZ2File: a68.  If you need to
          decompress a multi-stream input with *note BZ2Decompressor:
          1ab4, you must use a new decompressor for each stream.

      -- Metodo: decompress (data, max_length=-1)

          Decompress 'data' (a *note bytes-like object: 193.), returning
          uncompressed data as bytes.  Some of 'data' may be buffered
          internally, for use in later calls to *note decompress():
          1296.  The returned data should be concatenated with the
          output of any previous calls to *note decompress(): 1296.

          If 'max_length' is nonnegative, returns at most 'max_length'
          bytes of decompressed data.  If this limit is reached and
          further output can be produced, the *note needs_input: 2e59.
          attribute will be set to ‘False’.  In this case, the next call
          to *note decompress(): fcc. may provide 'data' as ‘b''’ to
          obtain more of the output.

          If all of the input data was decompressed and returned (either
          because this was less than 'max_length' bytes, or because
          'max_length' was negative), the *note needs_input: 2e59.
          attribute will be set to ‘True’.

          Attempting to decompress data after the end of stream is
          reached raises an *note EOFError: 14e1.  Any data found after
          the end of the stream is ignored and saved in the *note
          unused_data: 2e5a. attribute.

          Cambiato nella versione 3.5: Added the 'max_length' parameter.

      -- Attributo: eof

          ‘True’ if the end-of-stream marker has been reached.

          Added in version 3.3.

      -- Attributo: unused_data

          Data found after the end of the compressed stream.

          If this attribute is accessed before the end of the stream has
          been reached, its value will be ‘b''’.

      -- Attributo: needs_input

          ‘False’ if the *note decompress(): fcc. method can provide
          more decompressed data before requiring new uncompressed
          input.

          Added in version 3.5.


File: python.info,  Node: One-shot de compression,  Next: Examples of usage<2>,  Prev: Incremental de compression,  Up: bz2 — Support for bzip2 compression

5.13.5.3 One-shot (de)compression
.................................

 -- Funzione: bz2.compress (data, compresslevel=9)

     Compress 'data', a *note bytes-like object: 193.

     'compresslevel', if given, must be an integer between ‘1’ and ‘9’.
     The default is ‘9’.

     For incremental compression, use a *note BZ2Compressor: 1ab6.
     instead.

 -- Funzione: bz2.decompress (data)

     Decompress 'data', a *note bytes-like object: 193.

     If 'data' is the concatenation of multiple compressed streams,
     decompress all of the streams.

     For incremental decompression, use a *note BZ2Decompressor: 1ab4.
     instead.

     Cambiato nella versione 3.3: Support for multi-stream inputs was
     added.


File: python.info,  Node: Examples of usage<2>,  Prev: One-shot de compression,  Up: bz2 — Support for bzip2 compression

5.13.5.4 Examples of usage
..........................

Below are some examples of typical usage of the *note bz2: 14. module.

Using *note compress(): 2861. and *note decompress(): 1296. to
demonstrate round-trip compression:

     >>> import bz2
     >>> data = b"""\
     ... Donec rhoncus quis sapien sit amet molestie. Fusce scelerisque vel augue
     ... nec ullamcorper. Nam rutrum pretium placerat. Aliquam vel tristique lorem,
     ... sit amet cursus ante. In interdum laoreet mi, sit amet ultrices purus
     ... pulvinar a. Nam gravida euismod magna, non varius justo tincidunt feugiat.
     ... Aliquam pharetra lacus non risus vehicula rutrum. Maecenas aliquam leo
     ... felis. Pellentesque semper nunc sit amet nibh ullamcorper, ac elementum
     ... dolor luctus. Curabitur lacinia mi ornare consectetur vestibulum."""
     >>> c = bz2.compress(data)
     >>> len(data) / len(c)  # Data compression ratio
     1.513595166163142
     >>> d = bz2.decompress(c)
     >>> data == d  # Check equality to original object after round-trip
     True

Using *note BZ2Compressor: 1ab6. for incremental compression:

     >>> import bz2
     >>> def gen_data(chunks=10, chunksize=1000):
     ...     """Yield incremental blocks of chunksize bytes."""
     ...     for _ in range(chunks):
     ...         yield b"z" * chunksize
     ...
     >>> comp = bz2.BZ2Compressor()
     >>> out = b""
     >>> for chunk in gen_data():
     ...     # Provide data to the compressor object
     ...     out = out + comp.compress(chunk)
     ...
     >>> # Finish the compression process.  Call this once you have
     >>> # finished providing data to the compressor.
     >>> out = out + comp.flush()

The example above uses a very «nonrandom» stream of data (a stream of
‘b"z"’ chunks).  Random data tends to compress poorly, while ordered,
repetitive data usually yields a high compression ratio.

Writing and reading a bzip2-compressed file in binary mode:

     >>> import bz2
     >>> data = b"""\
     ... Donec rhoncus quis sapien sit amet molestie. Fusce scelerisque vel augue
     ... nec ullamcorper. Nam rutrum pretium placerat. Aliquam vel tristique lorem,
     ... sit amet cursus ante. In interdum laoreet mi, sit amet ultrices purus
     ... pulvinar a. Nam gravida euismod magna, non varius justo tincidunt feugiat.
     ... Aliquam pharetra lacus non risus vehicula rutrum. Maecenas aliquam leo
     ... felis. Pellentesque semper nunc sit amet nibh ullamcorper, ac elementum
     ... dolor luctus. Curabitur lacinia mi ornare consectetur vestibulum."""
     >>> with bz2.open("myfile.bz2", "wb") as f:
     ...     # Write compressed data to file
     ...     unused = f.write(data)
     ...
     >>> with bz2.open("myfile.bz2", "rb") as f:
     ...     # Decompress data from file
     ...     content = f.read()
     ...
     >>> content == data  # Check equality to original object after round-trip
     True


File: python.info,  Node: lzma — Compression using the LZMA algorithm,  Next: zipfile — Work with ZIP archives,  Prev: bz2 — Support for bzip2 compression,  Up: Data Compression and Archiving

5.13.6 ‘lzma’ — Compression using the LZMA algorithm
----------------------------------------------------

Added in version 3.3.

'Source code:' Lib/lzma.py(1)

__________________________________________________________________

This module provides classes and convenience functions for compressing
and decompressing data using the LZMA compression algorithm.  Also
included is a file interface supporting the ‘.xz’ and legacy ‘.lzma’
file formats used by the ‘xz’ utility, as well as raw compressed
streams.

The interface provided by this module is very similar to that of the
*note bz2: 14. module.  Note that *note LZMAFile: 120e. and *note
bz2.BZ2File: a68. are 'not' thread-safe, so if you need to use a single
*note LZMAFile: 120e. instance from multiple threads, it is necessary to
protect it with a lock.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

 -- Eccezione: lzma.LZMAError

     This exception is raised when an error occurs during compression or
     decompression, or while initializing the compressor/decompressor
     state.

* Menu:

* Reading and writing compressed files: Reading and writing compressed files<2>.
* Compressing and decompressing data in memory: Compressing and decompressing data in memory<2>.
* Miscellaneous: Miscellaneous<3>.
* Specifying custom filter chains::
* Examples: Examples<9>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/lzma.py


File: python.info,  Node: Reading and writing compressed files<2>,  Next: Compressing and decompressing data in memory<2>,  Up: lzma — Compression using the LZMA algorithm

5.13.6.1 Reading and writing compressed files
.............................................

 -- Funzione: lzma.open (filename, mode='rb', *, format=None, check=-1,
          preset=None, filters=None, encoding=None, errors=None,
          newline=None)

     Open an LZMA-compressed file in binary or text mode, returning a
     *note file object: 13cb.

     The 'filename' argument can be either an actual file name (given as
     a *note str: 169, *note bytes: 192. or *note path-like: 5a1.
     object), in which case the named file is opened, or it can be an
     existing file object to read from or write to.

     The 'mode' argument can be any of ‘"r"’, ‘"rb"’, ‘"w"’, ‘"wb"’,
     ‘"x"’, ‘"xb"’, ‘"a"’ or ‘"ab"’ for binary mode, or ‘"rt"’, ‘"wt"’,
     ‘"xt"’, or ‘"at"’ for text mode.  The default is ‘"rb"’.

     When opening a file for reading, the 'format' and 'filters'
     arguments have the same meanings as for *note LZMADecompressor:
     1ab3.  In this case, the 'check' and 'preset' arguments should not
     be used.

     When opening a file for writing, the 'format', 'check', 'preset'
     and 'filters' arguments have the same meanings as for *note
     LZMACompressor: 1ab5.

     For binary mode, this function is equivalent to the *note LZMAFile:
     120e. constructor: ‘LZMAFile(filename, mode, ...)’.  In this case,
     the 'encoding', 'errors' and 'newline' arguments must not be
     provided.

     For text mode, a *note LZMAFile: 120e. object is created, and
     wrapped in an *note io.TextIOWrapper: 9c0. instance with the
     specified encoding, error handling behavior, and line ending(s).

     Cambiato nella versione 3.4: Added support for the ‘"x"’, ‘"xb"’
     and ‘"xt"’ modes.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Classe: lzma.LZMAFile (filename=None, mode='r', *, format=None,
          check=-1, preset=None, filters=None)

     Open an LZMA-compressed file in binary mode.

     An *note LZMAFile: 120e. can wrap an already-open *note file
     object: 13cb, or operate directly on a named file.  The 'filename'
     argument specifies either the file object to wrap, or the name of
     the file to open (as a *note str: 169, *note bytes: 192. or *note
     path-like: 5a1. object).  When wrapping an existing file object,
     the wrapped file will not be closed when the *note LZMAFile: 120e.
     is closed.

     The 'mode' argument can be either ‘"r"’ for reading (default),
     ‘"w"’ for overwriting, ‘"x"’ for exclusive creation, or ‘"a"’ for
     appending.  These can equivalently be given as ‘"rb"’, ‘"wb"’,
     ‘"xb"’ and ‘"ab"’ respectively.

     If 'filename' is a file object (rather than an actual file name), a
     mode of ‘"w"’ does not truncate the file, and is instead equivalent
     to ‘"a"’.

     When opening a file for reading, the input file may be the
     concatenation of multiple separate compressed streams.  These are
     transparently decoded as a single logical stream.

     When opening a file for reading, the 'format' and 'filters'
     arguments have the same meanings as for *note LZMADecompressor:
     1ab3.  In this case, the 'check' and 'preset' arguments should not
     be used.

     When opening a file for writing, the 'format', 'check', 'preset'
     and 'filters' arguments have the same meanings as for *note
     LZMACompressor: 1ab5.

     *note LZMAFile: 120e. supports all the members specified by *note
     io.BufferedIOBase: 8a4, except for *note detach(): 2dd1. and *note
     truncate(): 1518.  Iteration and the *note with: 186. statement are
     supported.

     The following method and attributes are also provided:

      -- Metodo: peek (size=-1)

          Return buffered data without advancing the file position.  At
          least one byte of data will be returned, unless EOF has been
          reached.  The exact number of bytes returned is unspecified
          (the 'size' argument is ignored).

               Nota: While calling *note peek(): 2e65. does not change
               the file position of the *note LZMAFile: 120e, it may
               change the position of the underlying file object (e.g.
               if the *note LZMAFile: 120e. was constructed by passing a
               file object for 'filename').

      -- Attributo: mode

          ‘'rb'’ for reading and ‘'wb'’ for writing.

          Added in version 3.13.

      -- Attributo: name

          The lzma file name.  Equivalent to the *note name: 2dd5.
          attribute of the underlying *note file object: 13cb.

          Added in version 3.13.

     Cambiato nella versione 3.4: Added support for the ‘"x"’ and ‘"xb"’
     modes.

     Cambiato nella versione 3.5: The *note read(): 1530. method now
     accepts an argument of ‘None’.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.


File: python.info,  Node: Compressing and decompressing data in memory<2>,  Next: Miscellaneous<3>,  Prev: Reading and writing compressed files<2>,  Up: lzma — Compression using the LZMA algorithm

5.13.6.2 Compressing and decompressing data in memory
.....................................................

 -- Classe: lzma.LZMACompressor (format=FORMAT_XZ, check=-1,
          preset=None, filters=None)

     Create a compressor object, which can be used to compress data
     incrementally.

     For a more convenient way of compressing a single chunk of data,
     see *note compress(): 2e69.

     The 'format' argument specifies what container format should be
     used.  Possible values are:

        * 
          ‘FORMAT_XZ’: The ‘.xz’ container format.

               This is the default format.

        * 
          ‘FORMAT_ALONE’: The legacy ‘.lzma’ container format.

               This format is more limited than ‘.xz’ – it does not
               support integrity checks or multiple filters.

        * 
          ‘FORMAT_RAW’: A raw data stream, not using any container format.

               This format specifier does not support integrity checks,
               and requires that you always specify a custom filter
               chain (for both compression and decompression).
               Additionally, data compressed in this manner cannot be
               decompressed using ‘FORMAT_AUTO’ (see *note
               LZMADecompressor: 1ab3.).

     The 'check' argument specifies the type of integrity check to
     include in the compressed data.  This check is used when
     decompressing, to ensure that the data has not been corrupted.
     Possible values are:

        * ‘CHECK_NONE’: No integrity check.  This is the default (and
          the only acceptable value) for ‘FORMAT_ALONE’ and
          ‘FORMAT_RAW’.

        * ‘CHECK_CRC32’: 32-bit Cyclic Redundancy Check.

        * ‘CHECK_CRC64’: 64-bit Cyclic Redundancy Check.  This is the
          default for ‘FORMAT_XZ’.

        * ‘CHECK_SHA256’: 256-bit Secure Hash Algorithm.

     If the specified check is not supported, an *note LZMAError: 2e62.
     is raised.

     The compression settings can be specified either as a preset
     compression level (with the 'preset' argument), or in detail as a
     custom filter chain (with the 'filters' argument).

     The 'preset' argument (if provided) should be an integer between
     ‘0’ and ‘9’ (inclusive), optionally OR-ed with the constant
     ‘PRESET_EXTREME’.  If neither 'preset' nor 'filters' are given, the
     default behavior is to use ‘PRESET_DEFAULT’ (preset level ‘6’).
     Higher presets produce smaller output, but make the compression
     process slower.

          Nota: In addition to being more CPU-intensive, compression
          with higher presets also requires much more memory (and
          produces output that needs more memory to decompress).  With
          preset ‘9’ for example, the overhead for an *note
          LZMACompressor: 1ab5. object can be as high as 800 MiB. For
          this reason, it is generally best to stick with the default
          preset.

     The 'filters' argument (if provided) should be a filter chain
     specifier.  See *note Specifying custom filter chains: 2e6a. for
     details.

      -- Metodo: compress (data)

          Compress 'data' (a *note bytes: 192. object), returning a
          *note bytes: 192. object containing compressed data for at
          least part of the input.  Some of 'data' may be buffered
          internally, for use in later calls to *note compress(): 2e69.
          and *note flush(): 2e6c.  The returned data should be
          concatenated with the output of any previous calls to *note
          compress(): 2e69.

      -- Metodo: flush ()

          Finish the compression process, returning a *note bytes: 192.
          object containing any data stored in the compressor’s internal
          buffers.

          The compressor cannot be used after this method has been
          called.

 -- Classe: lzma.LZMADecompressor (format=FORMAT_AUTO, memlimit=None,
          filters=None)

     Create a decompressor object, which can be used to decompress data
     incrementally.

     For a more convenient way of decompressing an entire compressed
     stream at once, see *note decompress(): 2e6d.

     The 'format' argument specifies the container format that should be
     used.  The default is ‘FORMAT_AUTO’, which can decompress both
     ‘.xz’ and ‘.lzma’ files.  Other possible values are ‘FORMAT_XZ’,
     ‘FORMAT_ALONE’, and ‘FORMAT_RAW’.

     The 'memlimit' argument specifies a limit (in bytes) on the amount
     of memory that the decompressor can use.  When this argument is
     used, decompression will fail with an *note LZMAError: 2e62. if it
     is not possible to decompress the input within the given memory
     limit.

     The 'filters' argument specifies the filter chain that was used to
     create the stream being decompressed.  This argument is required if
     'format' is ‘FORMAT_RAW’, but should not be used for other formats.
     See *note Specifying custom filter chains: 2e6a. for more
     information about filter chains.

          Nota: This class does not transparently handle inputs
          containing multiple compressed streams, unlike *note
          decompress(): 2e6d. and *note LZMAFile: 120e.  To decompress a
          multi-stream input with *note LZMADecompressor: 1ab3, you must
          create a new decompressor for each stream.

      -- Metodo: decompress (data, max_length=-1)

          Decompress 'data' (a *note bytes-like object: 193.), returning
          uncompressed data as bytes.  Some of 'data' may be buffered
          internally, for use in later calls to *note decompress():
          2e6d.  The returned data should be concatenated with the
          output of any previous calls to *note decompress(): 2e6d.

          If 'max_length' is nonnegative, returns at most 'max_length'
          bytes of decompressed data.  If this limit is reached and
          further output can be produced, the *note needs_input: 2e6e.
          attribute will be set to ‘False’.  In this case, the next call
          to *note decompress(): 1030. may provide 'data' as ‘b''’ to
          obtain more of the output.

          If all of the input data was decompressed and returned (either
          because this was less than 'max_length' bytes, or because
          'max_length' was negative), the *note needs_input: 2e6e.
          attribute will be set to ‘True’.

          Attempting to decompress data after the end of stream is
          reached raises an *note EOFError: 14e1.  Any data found after
          the end of the stream is ignored and saved in the *note
          unused_data: 2e6f. attribute.

          Cambiato nella versione 3.5: Added the 'max_length' parameter.

      -- Attributo: check

          The ID of the integrity check used by the input stream.  This
          may be ‘CHECK_UNKNOWN’ until enough of the input has been
          decoded to determine what integrity check it uses.

      -- Attributo: eof

          ‘True’ if the end-of-stream marker has been reached.

      -- Attributo: unused_data

          Data found after the end of the compressed stream.

          Before the end of the stream is reached, this will be ‘b""’.

      -- Attributo: needs_input

          ‘False’ if the *note decompress(): 1030. method can provide
          more decompressed data before requiring new uncompressed
          input.

          Added in version 3.5.

 -- Funzione: lzma.compress (data, format=FORMAT_XZ, check=-1,
          preset=None, filters=None)

     Compress 'data' (a *note bytes: 192. object), returning the
     compressed data as a *note bytes: 192. object.

     See *note LZMACompressor: 1ab5. above for a description of the
     'format', 'check', 'preset' and 'filters' arguments.

 -- Funzione: lzma.decompress (data, format=FORMAT_AUTO, memlimit=None,
          filters=None)

     Decompress 'data' (a *note bytes: 192. object), returning the
     uncompressed data as a *note bytes: 192. object.

     If 'data' is the concatenation of multiple distinct compressed
     streams, decompress all of these streams, and return the
     concatenation of the results.

     See *note LZMADecompressor: 1ab3. above for a description of the
     'format', 'memlimit' and 'filters' arguments.


File: python.info,  Node: Miscellaneous<3>,  Next: Specifying custom filter chains,  Prev: Compressing and decompressing data in memory<2>,  Up: lzma — Compression using the LZMA algorithm

5.13.6.3 Miscellaneous
......................

 -- Funzione: lzma.is_check_supported (check)

     Return ‘True’ if the given integrity check is supported on this
     system.

     ‘CHECK_NONE’ and ‘CHECK_CRC32’ are always supported.  ‘CHECK_CRC64’
     and ‘CHECK_SHA256’ may be unavailable if you are using a version of
     ‘liblzma’ that was compiled with a limited feature set.


File: python.info,  Node: Specifying custom filter chains,  Next: Examples<9>,  Prev: Miscellaneous<3>,  Up: lzma — Compression using the LZMA algorithm

5.13.6.4 Specifying custom filter chains
........................................

A filter chain specifier is a sequence of dictionaries, where each
dictionary contains the ID and options for a single filter.  Each
dictionary must contain the key ‘"id"’, and may contain additional keys
to specify filter-dependent options.  Valid filter IDs are as follows:

   * Compression filters:

        * ‘FILTER_LZMA1’ (for use with ‘FORMAT_ALONE’)

        * ‘FILTER_LZMA2’ (for use with ‘FORMAT_XZ’ and ‘FORMAT_RAW’)

   * Delta filter:

        * ‘FILTER_DELTA’

   * Branch-Call-Jump (BCJ) filters:

        * ‘FILTER_X86’

        * ‘FILTER_IA64’

        * ‘FILTER_ARM’

        * ‘FILTER_ARMTHUMB’

        * ‘FILTER_POWERPC’

        * ‘FILTER_SPARC’

A filter chain can consist of up to 4 filters, and cannot be empty.  The
last filter in the chain must be a compression filter, and any other
filters must be delta or BCJ filters.

Compression filters support the following options (specified as
additional entries in the dictionary representing the filter):

   * ‘preset’: A compression preset to use as a source of default values
     for options that are not specified explicitly.

   * ‘dict_size’: Dictionary size in bytes.  This should be between 4
     KiB and 1.5 GiB (inclusive).

   * ‘lc’: Number of literal context bits.

   * ‘lp’: Number of literal position bits.  The sum ‘lc + lp’ must be
     at most 4.

   * ‘pb’: Number of position bits; must be at most 4.

   * ‘mode’: ‘MODE_FAST’ or ‘MODE_NORMAL’.

   * ‘nice_len’: What should be considered a «nice length» for a match.
     This should be 273 or less.

   * ‘mf’: What match finder to use – ‘MF_HC3’, ‘MF_HC4’, ‘MF_BT2’,
     ‘MF_BT3’, or ‘MF_BT4’.

   * ‘depth’: Maximum search depth used by match finder.  0 (default)
     means to select automatically based on other filter options.

The delta filter stores the differences between bytes, producing more
repetitive input for the compressor in certain circumstances.  It
supports one option, ‘dist’.  This indicates the distance between bytes
to be subtracted.  The default is 1, i.e.  take the differences between
adjacent bytes.

The BCJ filters are intended to be applied to machine code.  They
convert relative branches, calls and jumps in the code to use absolute
addressing, with the aim of increasing the redundancy that can be
exploited by the compressor.  These filters support one option,
‘start_offset’.  This specifies the address that should be mapped to the
beginning of the input data.  The default is 0.


File: python.info,  Node: Examples<9>,  Prev: Specifying custom filter chains,  Up: lzma — Compression using the LZMA algorithm

5.13.6.5 Examples
.................

Reading in a compressed file:

     import lzma
     with lzma.open("file.xz") as f:
         file_content = f.read()

Creating a compressed file:

     import lzma
     data = b"Insert Data Here"
     with lzma.open("file.xz", "w") as f:
         f.write(data)

Compressing data in memory:

     import lzma
     data_in = b"Insert Data Here"
     data_out = lzma.compress(data_in)

Incremental compression:

     import lzma
     lzc = lzma.LZMACompressor()
     out1 = lzc.compress(b"Some data\n")
     out2 = lzc.compress(b"Another piece of data\n")
     out3 = lzc.compress(b"Even more data\n")
     out4 = lzc.flush()
     # Concatenate all the partial results:
     result = b"".join([out1, out2, out3, out4])

Writing compressed data to an already-open file:

     import lzma
     with open("file.xz", "wb") as f:
         f.write(b"This data will not be compressed\n")
         with lzma.open(f, "w") as lzf:
             lzf.write(b"This *will* be compressed\n")
         f.write(b"Not compressed\n")

Creating a compressed file using a custom filter chain:

     import lzma
     my_filters = [
         {"id": lzma.FILTER_DELTA, "dist": 5},
         {"id": lzma.FILTER_LZMA2, "preset": 7 | lzma.PRESET_EXTREME},
     ]
     with lzma.open("file.xz", "w", filters=my_filters) as f:
         f.write(b"blah blah blah")


File: python.info,  Node: zipfile — Work with ZIP archives,  Next: tarfile — Read and write tar archive files,  Prev: lzma — Compression using the LZMA algorithm,  Up: Data Compression and Archiving

5.13.7 ‘zipfile’ — Work with ZIP archives
-----------------------------------------

'Source code:' Lib/zipfile/(1)

__________________________________________________________________

The ZIP file format is a common archive and compression standard.  This
module provides tools to create, read, write, append, and list a ZIP
file.  Any advanced use of this module will require an understanding of
the format, as defined in PKZIP Application Note(2).

This module does not handle multipart ZIP files.  It can handle ZIP
files that use the ZIP64 extensions (that is ZIP files that are more
than 4 GiB in size).  It supports decryption of encrypted files in ZIP
archives, but it cannot create an encrypted file.  Decryption is
extremely slow as it is implemented in native Python rather than C.

Handling compressed archives requires *note optional modules: 2143. such
as *note zlib: 139, *note bz2: 14, *note lzma: 8e, and *note
compression.zstd: 23.  If any of them are missing from your copy of
CPython, look for documentation from your distributor (that is, whoever
provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

The module defines the following items:

 -- Eccezione: zipfile.BadZipFile

     The error raised for bad ZIP files.

     Added in version 3.2.

 -- Eccezione: zipfile.BadZipfile

     Alias of *note BadZipFile: 1b50, for compatibility with older
     Python versions.

     Deprecato dalla versione 3.2.

 -- Eccezione: zipfile.LargeZipFile

     The error raised when a ZIP file would require ZIP64 functionality
     but that has not been enabled.

 -- Classe: zipfile.ZipFile

     The class for reading and writing ZIP files.  See section *note
     ZipFile objects: 2e7b. for constructor details.

 -- Classe: zipfile.Path

     Class that implements a subset of the interface provided by *note
     pathlib.Path: 266, including the full *note
     importlib.resources.abc.Traversable: 2fa. interface.

     Added in version 3.8.

 -- Classe: zipfile.PyZipFile

     Class for creating ZIP archives containing Python libraries.

 -- Classe: zipfile.ZipInfo (filename='NoName', date_time=(1980, 1, 1,
          0, 0, 0))

     Class used to represent information about a member of an archive.
     Instances of this class are returned by the *note getinfo(): 2e7c.
     and *note infolist(): 2e7d. methods of *note ZipFile: 8d4. objects.
     Most users of the *note zipfile: 137. module will not need to
     create these, but only use those created by this module.
     'filename' should be the full name of the archive member, and
     'date_time' should be a tuple containing six fields which describe
     the time of the last modification to the file; the fields are
     described in section *note ZipInfo objects: 2e7e.

     Cambiato nella versione 3.13: A public ‘compress_level’ attribute
     has been added to expose the formerly protected ‘_compresslevel’.
     The older protected name continues to work as a property for
     backwards compatibility.

      -- Metodo: _for_archive (archive)

          Resolve the date_time, compression attributes, and external
          attributes to suitable defaults as used by *note
          ZipFile.writestr(): 2cc.

          Returns self for chaining.

          Added in version 3.14.

 -- Funzione: zipfile.is_zipfile (filename)

     Returns ‘True’ if 'filename' is a valid ZIP file based on its magic
     number, otherwise returns ‘False’.  'filename' may be a file or
     file-like object too.

     Cambiato nella versione 3.1: Support for file and file-like
     objects.

 -- Dati: zipfile.ZIP_STORED

     The numeric constant for an uncompressed archive member.

 -- Dati: zipfile.ZIP_DEFLATED

     The numeric constant for the usual ZIP compression method.  This
     requires the *note zlib: 139. module.

 -- Dati: zipfile.ZIP_BZIP2

     The numeric constant for the BZIP2 compression method.  This
     requires the *note bz2: 14. module.

     Added in version 3.3.

 -- Dati: zipfile.ZIP_LZMA

     The numeric constant for the LZMA compression method.  This
     requires the *note lzma: 8e. module.

     Added in version 3.3.

 -- Dati: zipfile.ZIP_ZSTANDARD

     The numeric constant for Zstandard compression.  This requires the
     *note compression.zstd: 23. module.

          Nota: In APPNOTE 6.3.7, the method ID ‘20’ was assigned to
          Zstandard compression.  This was changed in APPNOTE 6.3.8 to
          method ID ‘93’ to avoid conflicts, with method ID ‘20’ being
          deprecated.  For compatibility, the ‘zipfile’ module reads
          both method IDs but will only write data with method ID ‘93’.

     Added in version 3.14.

     Nota: The ZIP file format specification has included support for
     bzip2 compression since 2001, for LZMA compression since 2006, and
     Zstandard compression since 2020.  However, some tools (including
     older Python releases) do not support these compression methods,
     and may either refuse to process the ZIP file altogether, or fail
     to extract individual files.

Vedi anche
..........

PKZIP Application Note(3)

     Documentation on the ZIP file format by Phil Katz, the creator of
     the format and algorithms used.

Info-ZIP Home Page(4)

     Information about the Info-ZIP project’s ZIP archive programs and
     development libraries.

* Menu:

* ZipFile objects::
* Path objects::
* PyZipFile objects::
* ZipInfo objects::
* Command-line interface: Command-line interface<4>.
* Decompression pitfalls::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/zipfile/

   (2) https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT

   (3) https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT

   (4) https://infozip.sourceforge.net/


File: python.info,  Node: ZipFile objects,  Next: Path objects,  Up: zipfile — Work with ZIP archives

5.13.7.1 ZipFile objects
........................

 -- Classe: zipfile.ZipFile (file, mode='r', compression=ZIP_STORED,
          allowZip64=True, compresslevel=None, *,
          strict_timestamps=True, metadata_encoding=None)

     Open a ZIP file, where 'file' can be a path to a file (a string), a
     file-like object or a *note path-like object: 5a1.

     The 'mode' parameter should be ‘'r'’ to read an existing file,
     ‘'w'’ to truncate and write a new file, ‘'a'’ to append to an
     existing file, or ‘'x'’ to exclusively create and write a new file.
     If 'mode' is ‘'x'’ and 'file' refers to an existing file, a *note
     FileExistsError: 1222. will be raised.  If 'mode' is ‘'a'’ and
     'file' refers to an existing ZIP file, then additional files are
     added to it.  If 'file' does not refer to a ZIP file, then a new
     ZIP archive is appended to the file.  This is meant for adding a
     ZIP archive to another file (such as ‘python.exe’).  If 'mode' is
     ‘'a'’ and the file does not exist at all, it is created.  If 'mode'
     is ‘'r'’ or ‘'a'’, the file should be seekable.

     'compression' is the ZIP compression method to use when writing the
     archive, and should be *note ZIP_STORED: 2e7f, *note ZIP_DEFLATED:
     2e80, *note ZIP_BZIP2: 2e81, *note ZIP_LZMA: 2e82, or *note
     ZIP_ZSTANDARD: 2e83.; unrecognized values will cause *note
     NotImplementedError: 36b. to be raised.  If *note ZIP_DEFLATED:
     2e80, *note ZIP_BZIP2: 2e81, *note ZIP_LZMA: 2e82, or *note
     ZIP_ZSTANDARD: 2e83. is specified but the corresponding module
     (*note zlib: 139, *note bz2: 14, *note lzma: 8e, or *note
     compression.zstd: 23.) is not available, *note RuntimeError: 244.
     is raised.  The default is *note ZIP_STORED: 2e7f.

     If 'allowZip64' is ‘True’ (the default) zipfile will create ZIP
     files that use the ZIP64 extensions when the zipfile is larger than
     4 GiB. If it is ‘false’ *note zipfile: 137. will raise an exception
     when the ZIP file would require ZIP64 extensions.

     The 'compresslevel' parameter controls the compression level to use
     when writing files to the archive.  When using *note ZIP_STORED:
     2e7f. or *note ZIP_LZMA: 2e82. it has no effect.  When using *note
     ZIP_DEFLATED: 2e80. integers ‘0’ through ‘9’ are accepted (see
     *note zlib: 2e19. for more information).  When using *note
     ZIP_BZIP2: 2e81. integers ‘1’ through ‘9’ are accepted (see *note
     bz2: a68. for more information).  When using *note ZIP_ZSTANDARD:
     2e83. integers ‘-131072’ through ‘22’ are commonly accepted (see
     *note CompressionParameter.compression_level: 2dd7. for more on
     retrieving valid values and their meaning).

     The 'strict_timestamps' argument, when set to ‘False’, allows to
     zip files older than 1980-01-01 at the cost of setting the
     timestamp to 1980-01-01.  Similar behavior occurs with files newer
     than 2107-12-31, the timestamp is also set to the limit.

     When mode is ‘'r'’, 'metadata_encoding' may be set to the name of a
     codec, which will be used to decode metadata such as the names of
     members and ZIP comments.

     If the file is created with mode ‘'w'’, ‘'x'’ or ‘'a'’ and then
     *note closed: 2e85. without adding any files to the archive, the
     appropriate ZIP structures for an empty archive will be written to
     the file.

     ZipFile is also a context manager and therefore supports the *note
     with: 186. statement.  In the example, 'myzip' is closed after the
     ‘with’ statement’s suite is finished—even if an exception occurs:

          with ZipFile('spam.zip', 'w') as myzip:
              myzip.write('eggs.txt')

          Nota: 'metadata_encoding' is an instance-wide setting for the
          ZipFile.  It is not possible to set this on a per-member
          basis.

          This attribute is a workaround for legacy implementations
          which produce archives with names in the current locale
          encoding or code page (mostly on Windows).  According to the
          .ZIP standard, the encoding of metadata may be specified to be
          either IBM code page (default) or UTF-8 by a flag in the
          archive header.  That flag takes precedence over
          'metadata_encoding', which is a Python-specific extension.

     Cambiato nella versione 3.2: Added the ability to use *note
     ZipFile: 8d4. as a context manager.

     Cambiato nella versione 3.3: Added support for *note bzip2: 14. and
     *note lzma: 8e. compression.

     Cambiato nella versione 3.4: ZIP64 extensions are enabled by
     default.

     Cambiato nella versione 3.5: Added support for writing to
     unseekable streams.  Added support for the ‘'x'’ mode.

     Cambiato nella versione 3.6: Previously, a plain *note
     RuntimeError: 244. was raised for unrecognized compression values.

     Cambiato nella versione 3.6.2: The 'file' parameter accepts a *note
     path-like object: 5a1.

     Cambiato nella versione 3.7: Add the 'compresslevel' parameter.

     Cambiato nella versione 3.8: The 'strict_timestamps' keyword-only
     parameter.

     Cambiato nella versione 3.11: Added support for specifying member
     name encoding for reading metadata in the zipfile’s directory and
     file headers.

 -- Metodo: ZipFile.close ()

     Close the archive file.  You must call *note close(): 2e85. before
     exiting your program or essential records will not be written.

 -- Metodo: ZipFile.getinfo (name)

     Return a *note ZipInfo: 2cb. object with information about the
     archive member 'name'.  Calling *note getinfo(): 2e7c. for a name
     not currently contained in the archive will raise a *note KeyError:
     5e7.

 -- Metodo: ZipFile.infolist ()

     Return a list containing a *note ZipInfo: 2cb. object for each
     member of the archive.  The objects are in the same order as their
     entries in the actual ZIP file on disk if an existing archive was
     opened.

 -- Metodo: ZipFile.namelist ()

     Return a list of archive members by name.

 -- Metodo: ZipFile.open (name, mode='r', pwd=None, *,
          force_zip64=False)

     Access a member of the archive as a binary file-like object.
     'name' can be either the name of a file within the archive or a
     *note ZipInfo: 2cb. object.  The 'mode' parameter, if included,
     must be ‘'r'’ (the default) or ‘'w'’.  'pwd' is the password used
     to decrypt encrypted ZIP files as a *note bytes: 192. object.

     *note open(): 65d. is also a context manager and therefore supports
     the *note with: 186. statement:

          with ZipFile('spam.zip') as myzip:
              with myzip.open('eggs.txt') as myfile:
                  print(myfile.read())

     With 'mode' ‘'r'’ the file-like object (‘ZipExtFile’) is read-only
     and provides the following methods: *note read(): 1530, *note
     readline(): 1531, *note readlines(): 2784, *note seek(): 1494,
     *note tell(): 15b4, *note __iter__(): 2094, *note __next__(): 14d5.
     These objects can operate independently of the ZipFile.

     With ‘mode='w'’, a writable file handle is returned, which supports
     the *note write(): ed9. method.  While a writable file handle is
     open, attempting to read or write other files in the ZIP file will
     raise a *note ValueError: 2ec.

     In both cases the file-like object has also attributes ‘name’,
     which is equivalent to the name of a file within the archive, and
     ‘mode’, which is ‘'rb'’ or ‘'wb'’ depending on the input mode.

     When writing a file, if the file size is not known in advance but
     may exceed 2 GiB, pass ‘force_zip64=True’ to ensure that the header
     format is capable of supporting large files.  If the file size is
     known in advance, construct a *note ZipInfo: 2cb. object with *note
     file_size: 2e87. set, and use that as the 'name' parameter.

          Nota: The *note open(): 65d, *note read(): 2e88. and *note
          extract(): 2e89. methods can take a filename or a *note
          ZipInfo: 2cb. object.  You will appreciate this when trying to
          read a ZIP file that contains members with duplicate names.

     Cambiato nella versione 3.6: Removed support of ‘mode='U'’.  Use
     *note io.TextIOWrapper: 9c0. for reading compressed text files in
     *note universal newlines: f37. mode.

     Cambiato nella versione 3.6: *note ZipFile.open(): 65d. can now be
     used to write files into the archive with the ‘mode='w'’ option.

     Cambiato nella versione 3.6: Calling *note open(): 65d. on a closed
     ZipFile will raise a *note ValueError: 2ec.  Previously, a *note
     RuntimeError: 244. was raised.

     Cambiato nella versione 3.13: Added attributes ‘name’ and ‘mode’
     for the writeable file-like object.  The value of the ‘mode’
     attribute for the readable file-like object was changed from ‘'r'’
     to ‘'rb'’.

 -- Metodo: ZipFile.extract (member, path=None, pwd=None)

     Extract a member from the archive to the current working directory;
     'member' must be its full name or a *note ZipInfo: 2cb. object.
     Its file information is extracted as accurately as possible.
     'path' specifies a different directory to extract to.  'member' can
     be a filename or a *note ZipInfo: 2cb. object.  'pwd' is the
     password used for encrypted files as a *note bytes: 192. object.

     Returns the normalized path created (a directory or new file).

          Nota: If a member filename is an absolute path, a drive/UNC
          sharepoint and leading (back)slashes will be stripped, e.g.:
          ‘///foo/bar’ becomes ‘foo/bar’ on Unix, and ‘C:\foo\bar’
          becomes ‘foo\bar’ on Windows.  And all ‘".."’ components in a
          member filename will be removed, e.g.: ‘../../foo../../ba..r’
          becomes ‘foo../ba..r’.  On Windows illegal characters (‘:’,
          ‘<’, ‘>’, ‘|’, ‘"’, ‘?’, and ‘*’) replaced by underscore
          (‘_’).

     Cambiato nella versione 3.6: Calling *note extract(): 2e89. on a
     closed ZipFile will raise a *note ValueError: 2ec.  Previously, a
     *note RuntimeError: 244. was raised.

     Cambiato nella versione 3.6.2: The 'path' parameter accepts a *note
     path-like object: 5a1.

 -- Metodo: ZipFile.extractall (path=None, members=None, pwd=None)

     Extract all members from the archive to the current working
     directory.  'path' specifies a different directory to extract to.
     'members' is optional and must be a subset of the list returned by
     *note namelist(): 2e86.  'pwd' is the password used for encrypted
     files as a *note bytes: 192. object.

          Avvertimento: Never extract archives from untrusted sources
          without prior inspection.  It is possible that files are
          created outside of 'path', e.g.  members that have absolute
          filenames starting with ‘"/"’ or filenames with two dots
          ‘".."’.  This module attempts to prevent that.  See *note
          extract(): 2e89. note.

     Cambiato nella versione 3.6: Calling *note extractall(): 2e8a. on a
     closed ZipFile will raise a *note ValueError: 2ec.  Previously, a
     *note RuntimeError: 244. was raised.

     Cambiato nella versione 3.6.2: The 'path' parameter accepts a *note
     path-like object: 5a1.

 -- Metodo: ZipFile.printdir ()

     Print a table of contents for the archive to ‘sys.stdout’.

 -- Metodo: ZipFile.setpassword (pwd)

     Set 'pwd' (a *note bytes: 192. object) as default password to
     extract encrypted files.

 -- Metodo: ZipFile.read (name, pwd=None)

     Return the bytes of the file 'name' in the archive.  'name' is the
     name of the file in the archive, or a *note ZipInfo: 2cb. object.
     The archive must be open for read or append.  'pwd' is the password
     used for encrypted files as a *note bytes: 192. object and, if
     specified, overrides the default password set with *note
     setpassword(): 2e8c.  Calling *note read(): 2e88. on a ZipFile that
     uses a compression method other than *note ZIP_STORED: 2e7f, *note
     ZIP_DEFLATED: 2e80, *note ZIP_BZIP2: 2e81, *note ZIP_LZMA: 2e82, or
     *note ZIP_ZSTANDARD: 2e83. will raise a *note NotImplementedError:
     36b.  An error will also be raised if the corresponding compression
     module is not available.

     Cambiato nella versione 3.6: Calling *note read(): 2e88. on a
     closed ZipFile will raise a *note ValueError: 2ec.  Previously, a
     *note RuntimeError: 244. was raised.

 -- Metodo: ZipFile.testzip ()

     Read all the files in the archive and check their CRC’s and file
     headers.  Return the name of the first bad file, or else return
     ‘None’.

     Cambiato nella versione 3.6: Calling *note testzip(): 2e8d. on a
     closed ZipFile will raise a *note ValueError: 2ec.  Previously, a
     *note RuntimeError: 244. was raised.

 -- Metodo: ZipFile.write (filename, arcname=None, compress_type=None,
          compresslevel=None)

     Write the file named 'filename' to the archive, giving it the
     archive name 'arcname' (by default, this will be the same as
     'filename', but without a drive letter and with leading path
     separators removed).  If given, 'compress_type' overrides the value
     given for the 'compression' parameter to the constructor for the
     new entry.  Similarly, 'compresslevel' will override the
     constructor if given.  The archive must be open with mode ‘'w'’,
     ‘'x'’ or ‘'a'’.

          Nota: The ZIP file standard historically did not specify a
          metadata encoding, but strongly recommended CP437 (the
          original IBM PC encoding) for interoperability.  Recent
          versions allow use of UTF-8 (only).  In this module, UTF-8
          will automatically be used to write the member names if they
          contain any non-ASCII characters.  It is not possible to write
          member names in any encoding other than ASCII or UTF-8.

          Nota: Archive names should be relative to the archive root,
          that is, they should not start with a path separator.

          Nota: If ‘arcname’ (or ‘filename’, if ‘arcname’ is not given)
          contains a null byte, the name of the file in the archive will
          be truncated at the null byte.

          Nota: A leading slash in the filename may lead to the archive
          being impossible to open in some zip programs on Windows
          systems.

     Cambiato nella versione 3.6: Calling *note write(): f4b. on a
     ZipFile created with mode ‘'r'’ or a closed ZipFile will raise a
     *note ValueError: 2ec.  Previously, a *note RuntimeError: 244. was
     raised.

 -- Metodo: ZipFile.writestr (zinfo_or_arcname, data,
          compress_type=None, compresslevel=None)

     Write a file into the archive.  The contents is 'data', which may
     be either a *note str: 169. or a *note bytes: 192. instance; if it
     is a *note str: 169, it is encoded as UTF-8 first.
     'zinfo_or_arcname' is either the file name it will be given in the
     archive, or a *note ZipInfo: 2cb. instance.  If it’s an instance,
     at least the filename, date, and time must be given.  If it’s a
     name, the date and time is set to the current date and time.  The
     archive must be opened with mode ‘'w'’, ‘'x'’ or ‘'a'’.

     If given, 'compress_type' overrides the value given for the
     'compression' parameter to the constructor for the new entry, or in
     the 'zinfo_or_arcname' (if that is a *note ZipInfo: 2cb. instance).
     Similarly, 'compresslevel' will override the constructor if given.

          Nota: When passing a *note ZipInfo: 2cb. instance as the
          'zinfo_or_arcname' parameter, the compression method used will
          be that specified in the 'compress_type' member of the given
          *note ZipInfo: 2cb. instance.  By default, the *note ZipInfo:
          2cb. constructor sets this member to *note ZIP_STORED: 2e7f.

     Cambiato nella versione 3.2: The 'compress_type' argument.

     Cambiato nella versione 3.6: Calling *note writestr(): 2cc. on a
     ZipFile created with mode ‘'r'’ or a closed ZipFile will raise a
     *note ValueError: 2ec.  Previously, a *note RuntimeError: 244. was
     raised.

 -- Metodo: ZipFile.mkdir (zinfo_or_directory, mode=511)

     Create a directory inside the archive.  If 'zinfo_or_directory' is
     a string, a directory is created inside the archive with the mode
     that is specified in the 'mode' argument.  If, however,
     'zinfo_or_directory' is a *note ZipInfo: 2cb. instance then the
     'mode' argument is ignored.

     The archive must be opened with mode ‘'w'’, ‘'x'’ or ‘'a'’.

     Added in version 3.11.

The following data attributes are also available:

 -- Attributo: ZipFile.filename

     Name of the ZIP file.

 -- Attributo: ZipFile.debug

     The level of debug output to use.  This may be set from ‘0’ (the
     default, no output) to ‘3’ (the most output).  Debugging
     information is written to ‘sys.stdout’.

 -- Attributo: ZipFile.comment

     The comment associated with the ZIP file as a *note bytes: 192.
     object.  If assigning a comment to a *note ZipFile: 8d4. instance
     created with mode ‘'w'’, ‘'x'’ or ‘'a'’, it should be no longer
     than 65535 bytes.  Comments longer than this will be truncated.


File: python.info,  Node: Path objects,  Next: PyZipFile objects,  Prev: ZipFile objects,  Up: zipfile — Work with ZIP archives

5.13.7.2 Path objects
.....................

 -- Classe: zipfile.Path (root, at='')

     Construct a Path object from a ‘root’ zipfile (which may be a *note
     ZipFile: 8d4. instance or ‘file’ suitable for passing to the *note
     ZipFile: 8d4. constructor).

     ‘at’ specifies the location of this Path within the zipfile, e.g.
     “dir/file.txt”, “dir/”, or “”.  Defaults to the empty string,
     indicating the root.

          Nota: The *note Path: 8d9. class does not sanitize filenames
          within the ZIP archive.  Unlike the *note ZipFile.extract():
          2e89. and *note ZipFile.extractall(): 2e8a. methods, it is the
          caller’s responsibility to validate or sanitize filenames to
          prevent path traversal vulnerabilities (e.g., filenames
          containing «..» or absolute paths).  When handling untrusted
          archives, consider resolving filenames using *note
          os.path.abspath(): 1522. and checking against the target
          directory with *note os.path.commonpath(): 103f.

Path objects expose the following features of *note pathlib.Path: 266.
objects:

Path objects are traversable using the ‘/’ operator or ‘joinpath’.

 -- Attributo: Path.name

     The final path component.

 -- Metodo: Path.open (mode='r', *, pwd, **)

     Invoke *note ZipFile.open(): 65d. on the current path.  Allows
     opening for read or write, text or binary through supported modes:
     “r”, “w”, “rb”, “wb”.  Positional and keyword arguments are passed
     through to *note io.TextIOWrapper: 9c0. when opened as text and
     ignored otherwise.  ‘pwd’ is the ‘pwd’ parameter to *note
     ZipFile.open(): 65d.

     Cambiato nella versione 3.9: Added support for text and binary
     modes for open.  Default mode is now text.

     Cambiato nella versione 3.11.2: The ‘encoding’ parameter can be
     supplied as a positional argument without causing a *note
     TypeError: 198.  As it could in 3.9.  Code needing to be compatible
     with unpatched 3.10 and 3.11 versions must pass all *note
     io.TextIOWrapper: 9c0. arguments, ‘encoding’ included, as keywords.

 -- Metodo: Path.iterdir ()

     Enumerate the children of the current directory.

 -- Metodo: Path.is_dir ()

     Return ‘True’ if the current context references a directory.

 -- Metodo: Path.is_file ()

     Return ‘True’ if the current context references a file.

 -- Metodo: Path.is_symlink ()

     Return ‘True’ if the current context references a symbolic link.

     Added in version 3.12.

     Cambiato nella versione 3.13: Previously, ‘is_symlink’ would
     unconditionally return ‘False’.

 -- Metodo: Path.exists ()

     Return ‘True’ if the current context references a file or directory
     in the zip file.

 -- Dati: Path.suffix

     The last dot-separated portion of the final component, if any.
     This is commonly called the file extension.

     Added in version 3.11: Added *note Path.suffix: 8d7. property.

 -- Dati: Path.stem

     The final path component, without its suffix.

     Added in version 3.11: Added *note Path.stem: 8d6. property.

 -- Dati: Path.suffixes

     A list of the path’s suffixes, commonly called file extensions.

     Added in version 3.11: Added *note Path.suffixes: 8d8. property.

 -- Metodo: Path.read_text (*, **)

     Read the current file as unicode text.  Positional and keyword
     arguments are passed through to *note io.TextIOWrapper: 9c0.
     (except ‘buffer’, which is implied by the context).

     Cambiato nella versione 3.11.2: The ‘encoding’ parameter can be
     supplied as a positional argument without causing a *note
     TypeError: 198.  As it could in 3.9.  Code needing to be compatible
     with unpatched 3.10 and 3.11 versions must pass all *note
     io.TextIOWrapper: 9c0. arguments, ‘encoding’ included, as keywords.

 -- Metodo: Path.read_bytes ()

     Read the current file as bytes.

 -- Metodo: Path.joinpath (*other)

     Return a new Path object with each of the 'other' arguments joined.
     The following are equivalent:

          >>> Path(...).joinpath('child').joinpath('grandchild')
          >>> Path(...).joinpath('child', 'grandchild')
          >>> Path(...) / 'child' / 'grandchild'

     Cambiato nella versione 3.10: Prior to 3.10, ‘joinpath’ was
     undocumented and accepted exactly one parameter.

The zipp(1) project provides backports of the latest path object
functionality to older Pythons.  Use ‘zipp.Path’ in place of
‘zipfile.Path’ for early access to changes.

   ---------- Footnotes ----------

   (1) https://pypi.org/project/zipp/


File: python.info,  Node: PyZipFile objects,  Next: ZipInfo objects,  Prev: Path objects,  Up: zipfile — Work with ZIP archives

5.13.7.3 PyZipFile objects
..........................

The *note PyZipFile: 11fb. constructor takes the same parameters as the
*note ZipFile: 8d4. constructor, and one additional parameter,
'optimize'.

 -- Classe: zipfile.PyZipFile (file, mode='r', compression=ZIP_STORED,
          allowZip64=True, optimize=-1)

     Cambiato nella versione 3.2: Added the 'optimize' parameter.

     Cambiato nella versione 3.4: ZIP64 extensions are enabled by
     default.

     Instances have one method in addition to those of *note ZipFile:
     8d4. objects:

      -- Metodo: writepy (pathname, basename='', filterfunc=None)

          Search for files ‘*.py’ and add the corresponding file to the
          archive.

          If the 'optimize' parameter to *note PyZipFile: 11fb. was not
          given or ‘-1’, the corresponding file is a ‘*.pyc’ file,
          compiling if necessary.

          If the 'optimize' parameter to *note PyZipFile: 11fb. was ‘0’,
          ‘1’ or ‘2’, only files with that optimization level (see *note
          compile(): 4b2.) are added to the archive, compiling if
          necessary.

          If 'pathname' is a file, the filename must end with ‘.py’, and
          just the (corresponding ‘*.pyc’) file is added at the top
          level (no path information).  If 'pathname' is a file that
          does not end with ‘.py’, a *note RuntimeError: 244. will be
          raised.  If it is a directory, and the directory is not a
          package directory, then all the files ‘*.pyc’ are added at the
          top level.  If the directory is a package directory, then all
          ‘*.pyc’ are added under the package name as a file path, and
          if any subdirectories are package directories, all of these
          are added recursively in sorted order.

          'basename' is intended for internal use only.

          'filterfunc', if given, must be a function taking a single
          string argument.  It will be passed each path (including each
          individual full file path) before it is added to the archive.
          If 'filterfunc' returns a false value, the path will not be
          added, and if it is a directory its contents will be ignored.
          For example, if our test files are all either in ‘test’
          directories or start with the string ‘test_’, we can use a
          'filterfunc' to exclude them:

               >>> zf = PyZipFile('myprog.zip')
               >>> def notests(s):
               ...     fn = os.path.basename(s)
               ...     return (not (fn == 'test' or fn.startswith('test_')))
               ...
               >>> zf.writepy('myprog', filterfunc=notests)

          The *note writepy(): 11fa. method makes archives with file
          names like this:

               string.pyc                   # Top level name
               test/__init__.pyc            # Package directory
               test/testall.pyc             # Module test.testall
               test/bogus/__init__.pyc      # Subpackage directory
               test/bogus/myfile.pyc        # Submodule test.bogus.myfile

          Cambiato nella versione 3.4: Added the 'filterfunc' parameter.

          Cambiato nella versione 3.6.2: The 'pathname' parameter
          accepts a *note path-like object: 5a1.

          Cambiato nella versione 3.7: Recursion sorts directory
          entries.


File: python.info,  Node: ZipInfo objects,  Next: Command-line interface<4>,  Prev: PyZipFile objects,  Up: zipfile — Work with ZIP archives

5.13.7.4 ZipInfo objects
........................

Instances of the *note ZipInfo: 2cb. class are returned by the *note
getinfo(): 2e7c. and *note infolist(): 2e7d. methods of *note ZipFile:
8d4. objects.  Each object stores information about a single member of
the ZIP archive.

There is one classmethod to make a *note ZipInfo: 2cb. instance for a
filesystem file:

 -- Metodo: classmethod ZipInfo.from_file (filename, arcname=None, *,
          strict_timestamps=True)

     Construct a *note ZipInfo: 2cb. instance for a file on the
     filesystem, in preparation for adding it to a zip file.

     'filename' should be the path to a file or directory on the
     filesystem.

     If 'arcname' is specified, it is used as the name within the
     archive.  If 'arcname' is not specified, the name will be the same
     as 'filename', but with any drive letter and leading path
     separators removed.

     The 'strict_timestamps' argument, when set to ‘False’, allows to
     zip files older than 1980-01-01 at the cost of setting the
     timestamp to 1980-01-01.  Similar behavior occurs with files newer
     than 2107-12-31, the timestamp is also set to the limit.

     Added in version 3.6.

     Cambiato nella versione 3.6.2: The 'filename' parameter accepts a
     *note path-like object: 5a1.

     Cambiato nella versione 3.8: Added the 'strict_timestamps'
     keyword-only parameter.

Instances have the following methods and attributes:

 -- Metodo: ZipInfo.is_dir ()

     Return ‘True’ if this archive member is a directory.

     This uses the entry’s name: directories should always end with ‘/’.

     Added in version 3.6.

 -- Attributo: ZipInfo.filename

     Name of the file in the archive.

 -- Attributo: ZipInfo.date_time

     The time and date of the last modification to the archive member.
     This is a tuple of six values representing the «last [modified]
     file time» and «last [modified] file date» fields from the ZIP
     file’s central directory.

     The tuple contains:

     Index       Value
                 
     -------------------------------------------
                 
     ‘0’         Year (>= 1980)
                 
                 
     ‘1’         Month (one-based)
                 
                 
     ‘2’         Day of month (one-based)
                 
                 
     ‘3’         Hours (zero-based)
                 
                 
     ‘4’         Minutes (zero-based)
                 
                 
     ‘5’         Seconds (zero-based)
                 

          Nota: The ZIP format supports multiple timestamp fields in
          different locations (central directory, extra fields for
          NTFS/UNIX systems, etc.).  This attribute specifically returns
          the timestamp from the central directory.  The central
          directory timestamp format in ZIP files does not support
          timestamps before 1980.  While some extra field formats (such
          as UNIX timestamps) can represent earlier dates, this
          attribute only returns the central directory timestamp.

          The central directory timestamp is interpreted as representing
          local time, rather than UTC time, to match the behavior of
          other zip tools.

 -- Attributo: ZipInfo.compress_type

     Type of compression for the archive member.

 -- Attributo: ZipInfo.comment

     Comment for the individual archive member as a *note bytes: 192.
     object.

 -- Attributo: ZipInfo.extra

     Expansion field data.  The PKZIP Application Note(1) contains some
     comments on the internal structure of the data contained in this
     *note bytes: 192. object.

 -- Attributo: ZipInfo.create_system

     System which created ZIP archive.

 -- Attributo: ZipInfo.create_version

     PKZIP version which created ZIP archive.

 -- Attributo: ZipInfo.extract_version

     PKZIP version needed to extract archive.

 -- Attributo: ZipInfo.reserved

     Must be zero.

 -- Attributo: ZipInfo.flag_bits

     ZIP flag bits.

 -- Attributo: ZipInfo.volume

     Volume number of file header.

 -- Attributo: ZipInfo.internal_attr

     Internal attributes.

 -- Attributo: ZipInfo.external_attr

     External file attributes.

 -- Attributo: ZipInfo.header_offset

     Byte offset to the file header.

 -- Attributo: ZipInfo.CRC

     CRC-32 of the uncompressed file.

 -- Attributo: ZipInfo.compress_size

     Size of the compressed data.

 -- Attributo: ZipInfo.file_size

     Size of the uncompressed file.

   ---------- Footnotes ----------

   (1) https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT


File: python.info,  Node: Command-line interface<4>,  Next: Decompression pitfalls,  Prev: ZipInfo objects,  Up: zipfile — Work with ZIP archives

5.13.7.5 Command-line interface
...............................

The *note zipfile: 137. module provides a simple command-line interface
to interact with ZIP archives.

If you want to create a new ZIP archive, specify its name after the
*note -c: 2eb0. option and then list the filename(s) that should be
included:

     $ python -m zipfile -c monty.zip spam.txt eggs.txt

Passing a directory is also acceptable:

     $ python -m zipfile -c monty.zip life-of-brian_1979/

If you want to extract a ZIP archive into the specified directory, use
the *note -e: 2eb1. option:

     $ python -m zipfile -e monty.zip target-dir/

For a list of the files in a ZIP archive, use the *note -l: 2eb2.
option:

     $ python -m zipfile -l monty.zip

* Menu:

* Command-line options: Command-line options<2>.


File: python.info,  Node: Command-line options<2>,  Up: Command-line interface<4>

5.13.7.6 Command-line options
.............................

 -- Option: -l <zipfile>
 -- Option: --list <zipfile>

     List files in a zipfile.

 -- Option: -c <zipfile> <source1> ... <sourceN>
 -- Option: --create <zipfile> <source1> ... <sourceN>

     Create zipfile from source files.

 -- Option: -e <zipfile> <output_dir>
 -- Option: --extract <zipfile> <output_dir>

     Extract zipfile into target directory.

 -- Option: -t <zipfile>
 -- Option: --test <zipfile>

     Test whether the zipfile is valid or not.

 -- Option: --metadata-encoding <encoding>

     Specify encoding of member names for *note -l: 2eb2, *note -e:
     2eb1. and *note -t: 2eb7.

     Added in version 3.11.


File: python.info,  Node: Decompression pitfalls,  Prev: Command-line interface<4>,  Up: zipfile — Work with ZIP archives

5.13.7.7 Decompression pitfalls
...............................

The extraction in zipfile module might fail due to some pitfalls listed
below.

* Menu:

* From file itself::
* File system limitations::
* Resources limitations::
* Interruption::
* Default behaviors of extraction::


File: python.info,  Node: From file itself,  Next: File system limitations,  Up: Decompression pitfalls

5.13.7.8 From file itself
.........................

Decompression may fail due to incorrect password / CRC checksum / ZIP
format or unsupported compression method / decryption.


File: python.info,  Node: File system limitations,  Next: Resources limitations,  Prev: From file itself,  Up: Decompression pitfalls

5.13.7.9 File system limitations
................................

Exceeding limitations on different file systems can cause decompression
failed.  Such as allowable characters in the directory entries, length
of the file name, length of the pathname, size of a single file, and
number of files, etc.


File: python.info,  Node: Resources limitations,  Next: Interruption,  Prev: File system limitations,  Up: Decompression pitfalls

5.13.7.10 Resources limitations
...............................

The lack of memory or disk volume would lead to decompression failed.
For example, decompression bombs (aka ZIP bomb(1)) apply to zipfile
library that can cause disk volume exhaustion.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Zip_bomb


File: python.info,  Node: Interruption,  Next: Default behaviors of extraction,  Prev: Resources limitations,  Up: Decompression pitfalls

5.13.7.11 Interruption
......................

Interruption during the decompression, such as pressing control-C or
killing the decompression process may result in incomplete decompression
of the archive.


File: python.info,  Node: Default behaviors of extraction,  Prev: Interruption,  Up: Decompression pitfalls

5.13.7.12 Default behaviors of extraction
.........................................

Not knowing the default extraction behaviors can cause unexpected
decompression results.  For example, when extracting the same archive
twice, it overwrites files without asking.


File: python.info,  Node: tarfile — Read and write tar archive files,  Prev: zipfile — Work with ZIP archives,  Up: Data Compression and Archiving

5.13.8 ‘tarfile’ — Read and write tar archive files
---------------------------------------------------

'Source code:' Lib/tarfile.py(1)

__________________________________________________________________

The *note tarfile: e4. module makes it possible to read and write tar
archives, including those using gzip, bz2 and lzma compression.  Use the
*note zipfile: 137. module to read or write ‘.zip’ files, or the
higher-level functions in *note shutil: 1420.

Some facts and figures:

   * reads and writes *note gzip: 6b, *note bz2: 14, *note
     compression.zstd: 23, and *note lzma: 8e. compressed archives if
     the respective modules are available.

     If any of these *note optional modules: 2143. are missing from your
     copy of CPython, look for documentation from your distributor (that
     is, whoever provided Python to you).  If you are the distributor,
     see *note Requirements for optional modules: 2141.

   * read/write support for the POSIX.1-1988 (ustar) format.

   * read/write support for the GNU tar format including 'longname' and
     'longlink' extensions, read-only support for all variants of the
     'sparse' extension including restoration of sparse files.

   * read/write support for the POSIX.1-2001 (pax) format.

   * handles directories, regular files, hardlinks, symbolic links,
     fifos, character devices and block devices and is able to acquire
     and restore file information like timestamp, access permissions and
     owner.

Cambiato nella versione 3.3: Added support for *note lzma: 8e.
compression.

Cambiato nella versione 3.12: Archives are extracted using a *note
filter: 698, which makes it possible to either limit
surprising/dangerous features, or to acknowledge that they are expected
and the archive is fully trusted.

Cambiato nella versione 3.14: Set the default extraction filter to *note
data: 29a, which disallows some dangerous features such as links to
absolute paths or paths outside of the destination.  Previously, the
filter strategy was equivalent to *note fully_trusted: 2ec4.

Cambiato nella versione 3.14: Added support for Zstandard compression
using *note compression.zstd: 23.

 -- Funzione: tarfile.open (name=None, mode='r', fileobj=None,
          bufsize=10240, **kwargs)

     Return a *note TarFile: 1418. object for the pathname 'name'.  For
     detailed information on *note TarFile: 1418. objects and the
     keyword arguments that are allowed, see *note TarFile Objects:
     2ec5.

     'mode' has to be a string of the form ‘'filemode[:compression]'’,
     it defaults to ‘'r'’.  Here is a full list of mode combinations:

     mode                   action
                            
     -------------------------------------------------------------------------
                            
     ‘'r'’ or ‘'r:*'’       Open for reading with transparent compression
                            (recommended).
                            
                            
     ‘'r:'’                 Open for reading exclusively without
                            compression.
                            
                            
     ‘'r:gz'’               Open for reading with gzip compression.
                            
                            
     ‘'r:bz2'’              Open for reading with bzip2 compression.
                            
                            
     ‘'r:xz'’               Open for reading with lzma compression.
                            
                            
     ‘'r:zst'’              Open for reading with Zstandard compression.
                            
                            
     ‘'x'’ or ‘'x:'’        Create a tarfile exclusively without
                            compression.  Raise a
                            *note FileExistsError: 1222. exception if it
                            already exists.
                            
                            
     ‘'x:gz'’               Create a tarfile with gzip compression.  Raise
                            a *note FileExistsError: 1222. exception if it
                            already exists.
                            
                            
     ‘'x:bz2'’              Create a tarfile with bzip2 compression.  Raise
                            a *note FileExistsError: 1222. exception if it
                            already exists.
                            
                            
     ‘'x:xz'’               Create a tarfile with lzma compression.  Raise
                            a *note FileExistsError: 1222. exception if it
                            already exists.
                            
                            
     ‘'x:zst'’              Create a tarfile with Zstandard compression.
                            Raise a *note FileExistsError: 1222. exception
                            if it already exists.
                            
                            
     ‘'a'’ or ‘'a:'’        Open for appending with no compression.  The
                            file is created if it does not exist.
                            
                            
     ‘'w'’ or ‘'w:'’        Open for uncompressed writing.
                            
                            
     ‘'w:gz'’               Open for gzip compressed writing.
                            
                            
     ‘'w:bz2'’              Open for bzip2 compressed writing.
                            
                            
     ‘'w:xz'’               Open for lzma compressed writing.
                            
                            
     ‘'w:zst'’              Open for Zstandard compressed writing.
                            

     Note that ‘'a:gz'’, ‘'a:bz2'’ or ‘'a:xz'’ is not possible.  If
     'mode' is not suitable to open a certain (compressed) file for
     reading, *note ReadError: 1c37. is raised.  Use 'mode' ‘'r'’ to
     avoid this.  If a compression method is not supported, *note
     CompressionError: 2ec6. is raised.

     If 'fileobj' is specified, it is used as an alternative to a *note
     file object: 13cb. opened in binary mode for 'name'.  It is
     supposed to be at position 0.

     For modes ‘'w:gz'’, ‘'x:gz'’, ‘'w|gz'’, ‘'w:bz2'’, ‘'x:bz2'’,
     ‘'w|bz2'’, *note tarfile.open(): 1079. accepts the keyword argument
     'compresslevel' (default ‘9’) to specify the compression level of
     the file.

     For modes ‘'w:xz'’, ‘'x:xz'’ and ‘'w|xz'’, *note tarfile.open():
     1079. accepts the keyword argument 'preset' to specify the
     compression level of the file.

     For modes ‘'w:zst'’, ‘'x:zst'’ and ‘'w|zst'’, *note tarfile.open():
     1079. accepts the keyword argument 'level' to specify the
     compression level of the file.  The keyword argument 'options' may
     also be passed, providing advanced Zstandard compression parameters
     described by *note CompressionParameter: 2dcb.  The keyword
     argument 'zstd_dict' can be passed to provide a *note ZstdDict:
     2dca, a Zstandard dictionary used to improve compression of smaller
     amounts of data.

     For special purposes, there is a second format for 'mode':
     ‘'filemode|[compression]'’.  *note tarfile.open(): 1079. will
     return a *note TarFile: 1418. object that processes its data as a
     stream of blocks.  No random seeking will be done on the file.  If
     given, 'fileobj' may be any object that has a *note read(): 101f.
     or *note write(): 15b3. method (depending on the 'mode') that works
     with bytes.  'bufsize' specifies the blocksize and defaults to ‘20
     * 512’ bytes.  Use this variant in combination with e.g.
     ‘sys.stdin.buffer’, a socket *note file object: 13cb. or a tape
     device.  However, such a *note TarFile: 1418. object is limited in
     that it does not allow random access, see *note Examples: 2ec7.
     The currently possible modes:

     Mode              Action
                       
     -------------------------------------------------------------------
                       
     ‘'r|*'’           Open a 'stream' of tar blocks for reading with
                       transparent compression.
                       
                       
     ‘'r|'’            Open a 'stream' of uncompressed tar blocks for
                       reading.
                       
                       
     ‘'r|gz'’          Open a gzip compressed 'stream' for reading.
                       
                       
     ‘'r|bz2'’         Open a bzip2 compressed 'stream' for reading.
                       
                       
     ‘'r|xz'’          Open an lzma compressed 'stream' for reading.
                       
                       
     ‘'r|zst'’         Open a Zstandard compressed 'stream' for
                       reading.
                       
                       
     ‘'w|'’            Open an uncompressed 'stream' for writing.
                       
                       
     ‘'w|gz'’          Open a gzip compressed 'stream' for writing.
                       
                       
     ‘'w|bz2'’         Open a bzip2 compressed 'stream' for writing.
                       
                       
     ‘'w|xz'’          Open an lzma compressed 'stream' for writing.
                       
                       
     ‘'w|zst'’         Open a Zstandard compressed 'stream' for
                       writing.
                       

     Cambiato nella versione 3.5: The ‘'x'’ (exclusive creation) mode
     was added.

     Cambiato nella versione 3.6: The 'name' parameter accepts a *note
     path-like object: 5a1.

     Cambiato nella versione 3.12: The 'compresslevel' keyword argument
     also works for streams.

     Cambiato nella versione 3.14: The 'preset' keyword argument also
     works for streams.

 -- Classe: tarfile.TarFile

     Class for reading and writing tar archives.  Do not use this class
     directly: use *note tarfile.open(): 1079. instead.  See *note
     TarFile Objects: 2ec5.

 -- Funzione: tarfile.is_tarfile (name)

     Return *note True: e09. if 'name' is a tar archive file, that the
     *note tarfile: e4. module can read.  'name' may be a *note str:
     169, file, or file-like object.

     Cambiato nella versione 3.9: Support for file and file-like
     objects.

The *note tarfile: e4. module defines the following exceptions:

 -- Eccezione: tarfile.TarError

     Base class for all *note tarfile: e4. exceptions.

 -- Eccezione: tarfile.ReadError

     Is raised when a tar archive is opened, that either cannot be
     handled by the *note tarfile: e4. module or is somehow invalid.

 -- Eccezione: tarfile.CompressionError

     Is raised when a compression method is not supported or when the
     data cannot be decoded properly.

 -- Eccezione: tarfile.StreamError

     Is raised for the limitations that are typical for stream-like
     *note TarFile: 1418. objects.

 -- Eccezione: tarfile.ExtractError

     Is raised for 'non-fatal' errors when using *note
     TarFile.extract(): 29c, but only if *note TarFile.errorlevel:
     29e.‘== 2’.

 -- Eccezione: tarfile.HeaderError

     Is raised by *note TarInfo.frombuf(): 2ecc. if the buffer it gets
     is invalid.

 -- Eccezione: tarfile.FilterError

     Base class for members *note refused: 2ece. by filters.

      -- Attributo: tarinfo

          Information about the member that the filter refused to
          extract, as *note TarInfo: 2ed0.

 -- Eccezione: tarfile.AbsolutePathError

     Raised to refuse extracting a member with an absolute path.

 -- Eccezione: tarfile.OutsideDestinationError

     Raised to refuse extracting a member outside the destination
     directory.

 -- Eccezione: tarfile.SpecialFileError

     Raised to refuse extracting a special file (e.g.  a device or
     pipe).

 -- Eccezione: tarfile.AbsoluteLinkError

     Raised to refuse extracting a symbolic link with an absolute path.

 -- Eccezione: tarfile.LinkOutsideDestinationError

     Raised to refuse extracting a symbolic link pointing outside the
     destination directory.

 -- Eccezione: tarfile.LinkFallbackError

     Raised to refuse emulating a link (hard or symbolic) by extracting
     another archive member, when that member would be rejected by the
     filter location.  The exception that was raised to reject the
     replacement member is available as ‘BaseException.__context__’.

     Added in version 3.14.

The following constants are available at the module level:

 -- Dati: tarfile.ENCODING

     The default character encoding: ‘'utf-8'’ on Windows, the value
     returned by *note sys.getfilesystemencoding(): e55. otherwise.

 -- Dati: tarfile.REGTYPE
 -- Dati: tarfile.AREGTYPE

     A regular file *note type: 2ed9.

 -- Dati: tarfile.LNKTYPE

     A link (inside tarfile) *note type: 2ed9.

 -- Dati: tarfile.SYMTYPE

     A symbolic link *note type: 2ed9.

 -- Dati: tarfile.CHRTYPE

     A character special device *note type: 2ed9.

 -- Dati: tarfile.BLKTYPE

     A block special device *note type: 2ed9.

 -- Dati: tarfile.DIRTYPE

     A directory *note type: 2ed9.

 -- Dati: tarfile.FIFOTYPE

     A FIFO special device *note type: 2ed9.

 -- Dati: tarfile.CONTTYPE

     A contiguous file *note type: 2ed9.

 -- Dati: tarfile.GNUTYPE_LONGNAME

     A GNU tar longname *note type: 2ed9.

 -- Dati: tarfile.GNUTYPE_LONGLINK

     A GNU tar longlink *note type: 2ed9.

 -- Dati: tarfile.GNUTYPE_SPARSE

     A GNU tar sparse file *note type: 2ed9.

Each of the following constants defines a tar archive format that the
*note tarfile: e4. module is able to create.  See section *note
Supported tar formats: 2ee4. for details.

 -- Dati: tarfile.USTAR_FORMAT

     POSIX.1-1988 (ustar) format.

 -- Dati: tarfile.GNU_FORMAT

     GNU tar format.

 -- Dati: tarfile.PAX_FORMAT

     POSIX.1-2001 (pax) format.

 -- Dati: tarfile.DEFAULT_FORMAT

     The default format for creating archives.  This is currently *note
     PAX_FORMAT: 2ee7.

     Cambiato nella versione 3.8: The default format for new archives
     was changed to *note PAX_FORMAT: 2ee7. from *note GNU_FORMAT: 2ee6.

Vedi anche
..........

Module *note zipfile: 137.

     Documentation of the *note zipfile: 137. standard module.

*note Archiving operations: 1420.

     Documentation of the higher-level archiving facilities provided by
     the standard *note shutil: ca. module.

GNU tar manual, Basic Tar Format(2)

     Documentation for tar archive files, including GNU tar extensions.

* Menu:

* TarFile Objects::
* TarInfo Objects::
* Extraction filters::
* Command-Line Interface::
* Examples: Examples<10>.
* Supported tar formats::
* Unicode issues::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/tarfile.py

   (2) https://www.gnu.org/software/tar/manual/html_node/Standard.html


File: python.info,  Node: TarFile Objects,  Next: TarInfo Objects,  Up: tarfile — Read and write tar archive files

5.13.8.1 TarFile Objects
........................

The *note TarFile: 1418. object provides an interface to a tar archive.
A tar archive is a sequence of blocks.  An archive member (a stored
file) is made up of a header block followed by data blocks.  It is
possible to store a file in a tar archive several times.  Each archive
member is represented by a *note TarInfo: 1419. object, see *note
TarInfo Objects: 2ed0. for details.

A *note TarFile: 1418. object can be used as a context manager in a
*note with: 186. statement.  It will automatically be closed when the
block is completed.  Please note that in the event of an exception an
archive opened for writing will not be finalized; only the internally
used file object will be closed.  See the *note Examples: 2ec7. section
for a use case.

Added in version 3.2: Added support for the context management protocol.

 -- Classe: tarfile.TarFile (name=None, mode='r', fileobj=None,
          format=DEFAULT_FORMAT, tarinfo=TarInfo, dereference=False,
          ignore_zeros=False, encoding=ENCODING,
          errors='surrogateescape', pax_headers=None, debug=0,
          errorlevel=1, stream=False)

     All following arguments are optional and can be accessed as
     instance attributes as well.

     'name' is the pathname of the archive.  'name' may be a *note
     path-like object: 5a1.  It can be omitted if 'fileobj' is given.
     In this case, the file object’s ‘name’ attribute is used if it
     exists.

     'mode' is either ‘'r'’ to read from an existing archive, ‘'a'’ to
     append data to an existing file, ‘'w'’ to create a new file
     overwriting an existing one, or ‘'x'’ to create a new file only if
     it does not already exist.

     If 'fileobj' is given, it is used for reading or writing data.  If
     it can be determined, 'mode' is overridden by 'fileobj'’s mode.
     'fileobj' will be used from position 0.

          Nota: 'fileobj' is not closed, when *note TarFile: 1418. is
          closed.

     'format' controls the archive format for writing.  It must be one
     of the constants *note USTAR_FORMAT: 2ee5, *note GNU_FORMAT: 2ee6.
     or *note PAX_FORMAT: 2ee7. that are defined at module level.  When
     reading, format will be automatically detected, even if different
     formats are present in a single archive.

     The 'tarinfo' argument can be used to replace the default *note
     TarInfo: 1419. class with a different one.

     If 'dereference' is *note False: d2d, add symbolic and hard links
     to the archive.  If it is *note True: e09, add the content of the
     target files to the archive.  This has no effect on systems that do
     not support symbolic links.

     If 'ignore_zeros' is *note False: d2d, treat an empty block as the
     end of the archive.  If it is *note True: e09, skip empty (and
     invalid) blocks and try to get as many members as possible.  This
     is only useful for reading concatenated or damaged archives.

     'debug' can be set from ‘0’ (no debug messages) up to ‘3’ (all
     debug messages).  The messages are written to ‘sys.stderr’.

     'errorlevel' controls how extraction errors are handled, see *note
     the corresponding attribute: 29e.

     The 'encoding' and 'errors' arguments define the character encoding
     to be used for reading or writing the archive and how conversion
     errors are going to be handled.  The default settings will work for
     most users.  See section *note Unicode issues: 2eea. for in-depth
     information.

     The 'pax_headers' argument is an optional dictionary of strings
     which will be added as a pax global header if 'format' is *note
     PAX_FORMAT: 2ee7.

     If 'stream' is set to *note True: e09. then while reading the
     archive info about files in the archive are not cached, saving
     memory.

     Cambiato nella versione 3.2: Use ‘'surrogateescape'’ as the default
     for the 'errors' argument.

     Cambiato nella versione 3.5: The ‘'x'’ (exclusive creation) mode
     was added.

     Cambiato nella versione 3.6: The 'name' parameter accepts a *note
     path-like object: 5a1.

     Cambiato nella versione 3.13: Add the 'stream' parameter.

 -- Metodo: classmethod TarFile.open (...)

     Alternative constructor.  The *note tarfile.open(): 1079. function
     is actually a shortcut to this classmethod.

 -- Metodo: TarFile.getmember (name)

     Return a *note TarInfo: 1419. object for member 'name'.  If 'name'
     can not be found in the archive, *note KeyError: 5e7. is raised.

          Nota: If a member occurs more than once in the archive, its
          last occurrence is assumed to be the most up-to-date version.

 -- Metodo: TarFile.getmembers ()

     Return the members of the archive as a list of *note TarInfo: 1419.
     objects.  The list has the same order as the members in the
     archive.

 -- Metodo: TarFile.getnames ()

     Return the members as a list of their names.  It has the same order
     as the list returned by *note getmembers(): 107b.

 -- Metodo: TarFile.list (verbose=True, *, members=None)

     Print a table of contents to ‘sys.stdout’.  If 'verbose' is *note
     False: d2d, only the names of the members are printed.  If it is
     *note True: e09, output similar to that of ‘ls -l’ is produced.  If
     optional 'members' is given, it must be a subset of the list
     returned by *note getmembers(): 107b.

     Cambiato nella versione 3.5: Added the 'members' parameter.

 -- Metodo: TarFile.next ()

     Return the next member of the archive as a *note TarInfo: 1419.
     object, when *note TarFile: 1418. is opened for reading.  Return
     *note None: 886. if there is no more available.

 -- Metodo: TarFile.extractall (path='.', members=None, *,
          numeric_owner=False, filter=None)

     Extract all members from the archive to the current working
     directory or directory 'path'.  If optional 'members' is given, it
     must be a subset of the list returned by *note getmembers(): 107b.
     Directory information like owner, modification time and permissions
     are set after all members have been extracted.  This is done to
     work around two problems: A directory’s modification time is reset
     each time a file is created in it.  And, if a directory’s
     permissions do not allow writing, extracting files to it will fail.

     If 'numeric_owner' is *note True: e09, the uid and gid numbers from
     the tarfile are used to set the owner/group for the extracted
     files.  Otherwise, the named values from the tarfile are used.

     The 'filter' argument specifies how ‘members’ are modified or
     rejected before extraction.  See *note Extraction filters: 698. for
     details.  It is recommended to set this explicitly only if specific
     'tar' features are required, or as ‘filter='data'’ to support
     Python versions with a less secure default (3.13 and lower).

          Avvertimento: Never extract archives from untrusted sources
          without prior inspection.

          Since Python 3.14, the default (*note data: 29a.) will prevent
          the most dangerous security issues.  However, it will not
          prevent 'all' unintended or insecure behavior.  Read the *note
          Extraction filters: 698. section for details.

     Cambiato nella versione 3.5: Added the 'numeric_owner' parameter.

     Cambiato nella versione 3.6: The 'path' parameter accepts a *note
     path-like object: 5a1.

     Cambiato nella versione 3.12: Added the 'filter' parameter.

     Cambiato nella versione 3.14: The 'filter' parameter now defaults
     to ‘'data'’.

 -- Metodo: TarFile.extract (member, path='', set_attrs=True, *,
          numeric_owner=False, filter=None)

     Extract a member from the archive to the current working directory,
     using its full name.  Its file information is extracted as
     accurately as possible.  'member' may be a filename or a *note
     TarInfo: 1419. object.  You can specify a different directory using
     'path'.  'path' may be a *note path-like object: 5a1.  File
     attributes (owner, mtime, mode) are set unless 'set_attrs' is
     false.

     The 'numeric_owner' and 'filter' arguments are the same as for
     *note extractall(): 29b.

          Nota: The *note extract(): 29c. method does not take care of
          several extraction issues.  In most cases you should consider
          using the *note extractall(): 29b. method.

          Avvertimento: Never extract archives from untrusted sources
          without prior inspection.  See the warning for *note
          extractall(): 29b. for details.

     Cambiato nella versione 3.2: Added the 'set_attrs' parameter.

     Cambiato nella versione 3.5: Added the 'numeric_owner' parameter.

     Cambiato nella versione 3.6: The 'path' parameter accepts a *note
     path-like object: 5a1.

     Cambiato nella versione 3.12: Added the 'filter' parameter.

 -- Metodo: TarFile.extractfile (member)

     Extract a member from the archive as a file object.  'member' may
     be a filename or a *note TarInfo: 1419. object.  If 'member' is a
     regular file or a link, an *note io.BufferedReader: 1416. object is
     returned.  For all other existing members, *note None: 886. is
     returned.  If 'member' does not appear in the archive, *note
     KeyError: 5e7. is raised.

     Cambiato nella versione 3.3: Return an *note io.BufferedReader:
     1416. object.

     Cambiato nella versione 3.13: The returned *note io.BufferedReader:
     1416. object has the ‘mode’ attribute which is always equal to
     ‘'rb'’.

 -- Attributo: TarFile.errorlevel: *note int: 19b.

     If 'errorlevel' is ‘0’, errors are ignored when using *note
     TarFile.extract(): 29c. and *note TarFile.extractall(): 29b.
     Nevertheless, they appear as error messages in the debug output
     when 'debug' is greater than 0.  If ‘1’ (the default), all 'fatal'
     errors are raised as *note OSError: 2c0. or *note FilterError:
     2ecd. exceptions.  If ‘2’, all 'non-fatal' errors are raised as
     *note TarError: 2ec8. exceptions as well.

     Some exceptions, e.g.  ones caused by wrong argument types or data
     corruption, are always raised.

     Custom *note extraction filters: 698. should raise *note
     FilterError: 2ecd. for 'fatal' errors and *note ExtractError: 2eca.
     for 'non-fatal' ones.

     Note that when an exception is raised, the archive may be partially
     extracted.  It is the user’s responsibility to clean up.

 -- Attributo: TarFile.extraction_filter

     Added in version 3.12.

     The *note extraction filter: 698. used as a default for the
     'filter' argument of *note extract(): 29c. and *note extractall():
     29b.

     The attribute may be ‘None’ or a callable.  String names are not
     allowed for this attribute, unlike the 'filter' argument to *note
     extract(): 29c.

     If ‘extraction_filter’ is ‘None’ (the default), extraction methods
     will use the *note data: 29a. filter by default.

     The attribute may be set on instances or overridden in subclasses.
     It also is possible to set it on the ‘TarFile’ class itself to set
     a global default, although, since it affects all uses of 'tarfile',
     it is best practice to only do so in top-level applications or
     *note site configuration: cc.  To set a global default this way, a
     filter function needs to be wrapped in *note staticmethod(): 453.
     to prevent injection of a ‘self’ argument.

     Cambiato nella versione 3.14: The default filter is set to *note
     data: 29a, which disallows some dangerous features such as links to
     absolute paths or paths outside of the destination.  Previously,
     the default was equivalent to *note fully_trusted: 2ec4.

 -- Metodo: TarFile.add (name, arcname=None, recursive=True, *,
          filter=None)

     Add the file 'name' to the archive.  'name' may be any type of file
     (directory, fifo, symbolic link, etc.).  If given, 'arcname'
     specifies an alternative name for the file in the archive.
     Directories are added recursively by default.  This can be avoided
     by setting 'recursive' to *note False: d2d.  Recursion adds entries
     in sorted order.  If 'filter' is given, it should be a function
     that takes a *note TarInfo: 1419. object argument and returns the
     changed *note TarInfo: 1419. object.  If it instead returns *note
     None: 886. the *note TarInfo: 1419. object will be excluded from
     the archive.  See *note Examples: 2ec7. for an example.

     Cambiato nella versione 3.2: Added the 'filter' parameter.

     Cambiato nella versione 3.7: Recursion adds entries in sorted
     order.

 -- Metodo: TarFile.addfile (tarinfo, fileobj=None)

     Add the *note TarInfo: 1419. object 'tarinfo' to the archive.  If
     'tarinfo' represents a non zero-size regular file, the 'fileobj'
     argument should be a *note binary file: 2058, and ‘tarinfo.size’
     bytes are read from it and added to the archive.  You can create
     *note TarInfo: 1419. objects directly, or by using *note
     gettarinfo(): 2eef.

     Cambiato nella versione 3.13: 'fileobj' must be given for
     non-zero-sized regular files.

 -- Metodo: TarFile.gettarinfo (name=None, arcname=None, fileobj=None)

     Create a *note TarInfo: 1419. object from the result of *note
     os.stat(): 26d. or equivalent on an existing file.  The file is
     either named by 'name', or specified as a *note file object: 13cb.
     'fileobj' with a file descriptor.  'name' may be a *note path-like
     object: 5a1.  If given, 'arcname' specifies an alternative name for
     the file in the archive, otherwise, the name is taken from
     'fileobj'’s *note name: 2dd5. attribute, or the 'name' argument.
     The name should be a text string.

     You can modify some of the *note TarInfo: 1419.’s attributes before
     you add it using *note addfile(): 198f.  If the file object is not
     an ordinary file object positioned at the beginning of the file,
     attributes such as *note size: 2ef0. may need modifying.  This is
     the case for objects such as *note GzipFile: 65c.  The *note name:
     2ef1. may also be modified, in which case 'arcname' could be a
     dummy string.

     Cambiato nella versione 3.6: The 'name' parameter accepts a *note
     path-like object: 5a1.

 -- Metodo: TarFile.close ()

     Close the *note TarFile: 1418.  In write mode, two finishing zero
     blocks are appended to the archive.

 -- Attributo: TarFile.pax_headers: *note dict: 183.

     A dictionary containing key-value pairs of pax global headers.


File: python.info,  Node: TarInfo Objects,  Next: Extraction filters,  Prev: TarFile Objects,  Up: tarfile — Read and write tar archive files

5.13.8.2 TarInfo Objects
........................

A *note TarInfo: 1419. object represents one member in a *note TarFile:
1418.  Aside from storing all required attributes of a file (like file
type, size, time, permissions, owner etc.), it provides some useful
methods to determine its type.  It does 'not' contain the file’s data
itself.

*note TarInfo: 1419. objects are returned by *note TarFile: 1418.’s
methods *note getmember(): 1bd8, *note getmembers(): 107b. and *note
gettarinfo(): 2eef.

Modifying the objects returned by *note getmember(): 1bd8. or *note
getmembers(): 107b. will affect all subsequent operations on the
archive.  For cases where this is unwanted, you can use *note
copy.copy(): 29. or call the *note replace(): 2ef5. method to create a
modified copy in one step.

Several attributes can be set to ‘None’ to indicate that a piece of
metadata is unused or unknown.  Different *note TarInfo: 1419. methods
handle ‘None’ differently:

   - The *note extract(): 29c. or *note extractall(): 29b. methods will
     ignore the corresponding metadata, leaving it set to a default.

   - *note addfile(): 198f. will fail.

   - *note list(): 107a. will print a placeholder string.

 -- Classe: tarfile.TarInfo (name='')

     Create a *note TarInfo: 1419. object.

 -- Metodo: classmethod TarInfo.frombuf (buf, encoding, errors)

     Create and return a *note TarInfo: 1419. object from string buffer
     'buf'.

     Raises *note HeaderError: 2ecb. if the buffer is invalid.

 -- Metodo: classmethod TarInfo.fromtarfile (tarfile)

     Read the next member from the *note TarFile: 1418. object 'tarfile'
     and return it as a *note TarInfo: 1419. object.

 -- Metodo: TarInfo.tobuf (format=DEFAULT_FORMAT, encoding=ENCODING,
          errors='surrogateescape')

     Create a string buffer from a *note TarInfo: 1419. object.  For
     information on the arguments see the constructor of the *note
     TarFile: 1418. class.

     Cambiato nella versione 3.2: Use ‘'surrogateescape'’ as the default
     for the 'errors' argument.

A ‘TarInfo’ object has the following public data attributes:

 -- Attributo: TarInfo.name: *note str: 169.

     Name of the archive member.

 -- Attributo: TarInfo.size: *note int: 19b.

     Size in bytes.

 -- Attributo: TarInfo.mtime: *note int: 19b. | *note float: 196.

     Time of last modification in seconds since the *note epoch: 2ef9,
     as in *note os.stat_result.st_mtime: 2efa.

     Cambiato nella versione 3.12: Can be set to ‘None’ for *note
     extract(): 29c. and *note extractall(): 29b, causing extraction to
     skip applying this attribute.

 -- Attributo: TarInfo.mode: *note int: 19b.

     Permission bits, as for *note os.chmod(): 52a.

     Cambiato nella versione 3.12: Can be set to ‘None’ for *note
     extract(): 29c. and *note extractall(): 29b, causing extraction to
     skip applying this attribute.

 -- Attributo: TarInfo.type

     File type.  'type' is usually one of these constants: *note
     REGTYPE: 2ed7, *note AREGTYPE: 2ed8, *note LNKTYPE: 2eda, *note
     SYMTYPE: 2edb, *note DIRTYPE: 2ede, *note FIFOTYPE: 2edf, *note
     CONTTYPE: 2ee0, *note CHRTYPE: 2edc, *note BLKTYPE: 2edd, *note
     GNUTYPE_SPARSE: 2ee3.  To determine the type of a *note TarInfo:
     1419. object more conveniently, use the ‘is*()’ methods below.

 -- Attributo: TarInfo.linkname: *note str: 169.

     Name of the target file name, which is only present in *note
     TarInfo: 1419. objects of type *note LNKTYPE: 2eda. and *note
     SYMTYPE: 2edb.

     For symbolic links (‘SYMTYPE’), the 'linkname' is relative to the
     directory that contains the link.  For hard links (‘LNKTYPE’), the
     'linkname' is relative to the root of the archive.

 -- Attributo: TarInfo.uid: *note int: 19b.

     User ID of the user who originally stored this member.

     Cambiato nella versione 3.12: Can be set to ‘None’ for *note
     extract(): 29c. and *note extractall(): 29b, causing extraction to
     skip applying this attribute.

 -- Attributo: TarInfo.gid: *note int: 19b.

     Group ID of the user who originally stored this member.

     Cambiato nella versione 3.12: Can be set to ‘None’ for *note
     extract(): 29c. and *note extractall(): 29b, causing extraction to
     skip applying this attribute.

 -- Attributo: TarInfo.uname: *note str: 169.

     User name.

     Cambiato nella versione 3.12: Can be set to ‘None’ for *note
     extract(): 29c. and *note extractall(): 29b, causing extraction to
     skip applying this attribute.

 -- Attributo: TarInfo.gname: *note str: 169.

     Group name.

     Cambiato nella versione 3.12: Can be set to ‘None’ for *note
     extract(): 29c. and *note extractall(): 29b, causing extraction to
     skip applying this attribute.

 -- Attributo: TarInfo.chksum: *note int: 19b.

     Header checksum.

 -- Attributo: TarInfo.devmajor: *note int: 19b.

     Device major number.

 -- Attributo: TarInfo.devminor: *note int: 19b.

     Device minor number.

 -- Attributo: TarInfo.offset: *note int: 19b.

     The tar header starts here.

 -- Attributo: TarInfo.offset_data: *note int: 19b.

     The file’s data starts here.

 -- Attributo: TarInfo.sparse

     Sparse member information.

 -- Attributo: TarInfo.pax_headers: *note dict: 183.

     A dictionary containing key-value pairs of an associated pax
     extended header.

 -- Metodo: TarInfo.replace (name=..., mtime=..., mode=...,
          linkname=..., uid=..., gid=..., uname=..., gname=...,
          deep=True)

     Added in version 3.12.

     Return a 'new' copy of the ‘TarInfo’ object with the given
     attributes changed.  For example, to return a ‘TarInfo’ with the
     group name set to ‘'staff'’, use:

          new_tarinfo = old_tarinfo.replace(gname='staff')

     By default, a deep copy is made.  If 'deep' is false, the copy is
     shallow, i.e.  ‘pax_headers’ and any custom attributes are shared
     with the original ‘TarInfo’ object.

A *note TarInfo: 1419. object also provides some convenient query
methods:

 -- Metodo: TarInfo.isfile ()

     Return *note True: e09. if the *note TarInfo: 1419. object is a
     regular file.

 -- Metodo: TarInfo.isreg ()

     Same as *note isfile(): 2f08.

 -- Metodo: TarInfo.isdir ()

     Return *note True: e09. if it is a directory.

 -- Metodo: TarInfo.issym ()

     Return *note True: e09. if it is a symbolic link.

 -- Metodo: TarInfo.islnk ()

     Return *note True: e09. if it is a hard link.

 -- Metodo: TarInfo.ischr ()

     Return *note True: e09. if it is a character device.

 -- Metodo: TarInfo.isblk ()

     Return *note True: e09. if it is a block device.

 -- Metodo: TarInfo.isfifo ()

     Return *note True: e09. if it is a FIFO.

 -- Metodo: TarInfo.isdev ()

     Return *note True: e09. if it is one of character device, block
     device or FIFO.


File: python.info,  Node: Extraction filters,  Next: Command-Line Interface,  Prev: TarInfo Objects,  Up: tarfile — Read and write tar archive files

5.13.8.3 Extraction filters
...........................

Added in version 3.12.

The 'tar' format is designed to capture all details of a UNIX-like
filesystem, which makes it very powerful.  Unfortunately, the features
make it easy to create tar files that have unintended – and possibly
malicious – effects when extracted.  For example, extracting a tar file
can overwrite arbitrary files in various ways (e.g.  by using absolute
paths, ‘..’ path components, or symlinks that affect later members).

In most cases, the full functionality is not needed.  Therefore,
'tarfile' supports extraction filters: a mechanism to limit
functionality, and thus mitigate some of the security issues.

     Avvertimento: None of the available filters blocks 'all' dangerous
     archive features.  Never extract archives from untrusted sources
     without prior inspection.  See also *note Hints for further
     verification: 2cda.

Vedi anche
..........

PEP 706(1)

     Contains further motivation and rationale behind the design.

The 'filter' argument to *note TarFile.extract(): 29c. or *note
extractall(): 29b. can be:

   * the string ‘'fully_trusted'’: Honor all metadata as specified in
     the archive.  Should be used if the user trusts the archive
     completely, or implements their own complex verification.

   * the string ‘'tar'’: Honor most 'tar'-specific features (i.e.
     features of UNIX-like filesystems), but block features that are
     very likely to be surprising or malicious.  See *note tar_filter():
     2f12. for details.

   * the string ‘'data'’: Ignore or block most features specific to
     UNIX-like filesystems.  Intended for extracting cross-platform data
     archives.  See *note data_filter(): 29a. for details.

   * ‘None’ (default): Use *note TarFile.extraction_filter: 2eee.

     If that is also ‘None’ (the default), the ‘'data'’ filter will be
     used.

          Cambiato nella versione 3.14: The default filter is set to
          *note data: 29a.  Previously, the default was equivalent to
          *note fully_trusted: 2ec4.

   * A callable which will be called for each extracted member with a
     *note TarInfo: 2ed0. describing the member and the destination path
     to where the archive is extracted (i.e.  the same path is used for
     all members):

          filter(member: TarInfo, path: str, /) -> TarInfo | None

     The callable is called just before each member is extracted, so it
     can take the current state of the disk into account.  It can:

        - return a *note TarInfo: 1419. object which will be used
          instead of the metadata in the archive, or

        - return ‘None’, in which case the member will be skipped, or

        - raise an exception to abort the operation or skip the member,
          depending on *note errorlevel: 29e.  Note that when extraction
          is aborted, *note extractall(): 29b. may leave the archive
          partially extracted.  It does not attempt to clean up.

* Menu:

* Default named filters::
* Filter errors::
* Hints for further verification::
* Supporting older Python versions::
* Stateful extraction filter example::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0706/


File: python.info,  Node: Default named filters,  Next: Filter errors,  Up: Extraction filters

5.13.8.4 Default named filters
..............................

The pre-defined, named filters are available as functions, so they can
be reused in custom filters:

 -- Funzione: tarfile.fully_trusted_filter (member, path)

     Return 'member' unchanged.

     This implements the ‘'fully_trusted'’ filter.

 -- Funzione: tarfile.tar_filter (member, path)

     Implements the ‘'tar'’ filter.

        - Strip leading slashes (‘/’ and *note os.sep: 87b.) from
          filenames.

        - *note Refuse: 2ece. to extract files with absolute paths (in
          case the name is absolute even after stripping slashes, e.g.
          ‘C:/foo’ on Windows).  This raises *note AbsolutePathError:
          2ed1.

        - *note Refuse: 2ece. to extract files whose absolute path
          (after following symlinks) would end up outside the
          destination.  This raises *note OutsideDestinationError: 2ed2.

        - Clear high mode bits (setuid, setgid, sticky) and group/other
          write bits (*note S_IWGRP: 2c66. | *note S_IWOTH: 2c69.).

     Return the modified ‘TarInfo’ member.

 -- Funzione: tarfile.data_filter (member, path)

     Implements the ‘'data'’ filter.  In addition to what ‘tar_filter’
     does:

        - Normalize link targets (*note TarInfo.linkname: 2efc.) using
          *note os.path.normpath(): 1521.  Note that this removes
          internal ‘..’ components, which may change the meaning of the
          link if the path in ‘TarInfo.linkname’ traverses symbolic
          links.

        - *note Refuse: 2ece. to extract links (hard or soft) that link
          to absolute paths, or ones that link outside the destination.

          This raises *note AbsoluteLinkError: 2ed4. or *note
          LinkOutsideDestinationError: 2ed5.

          Note that such files are refused even on platforms that do not
          support symbolic links.

        - *note Refuse: 2ece. to extract device files (including pipes).
          This raises *note SpecialFileError: 2ed3.

        - For regular files, including hard links:

             - Set the owner read and write permissions (*note S_IRUSR:
               2c61. | *note S_IWUSR: 2c62.).

             - Remove the group & other executable permission (*note
               S_IXGRP: 2c5d. | *note S_IXOTH: 2c6a.) if the owner
               doesn’t have it (*note S_IXUSR: 2c63.).

        - For other files (directories), set ‘mode’ to ‘None’, so that
          extraction methods skip applying permission bits.

        - Set user and group info (‘uid’, ‘gid’, ‘uname’, ‘gname’) to
          ‘None’, so that extraction methods skip setting it.

     Return the modified ‘TarInfo’ member.

     Note that this filter does not block 'all' dangerous archive
     features.  See *note Hints for further verification: 2cda. for
     details.

     Cambiato nella versione 3.14: Link targets are now normalized.


File: python.info,  Node: Filter errors,  Next: Hints for further verification,  Prev: Default named filters,  Up: Extraction filters

5.13.8.5 Filter errors
......................

When a filter refuses to extract a file, it will raise an appropriate
exception, a subclass of *note FilterError: 2ecd.  This will abort the
extraction if *note TarFile.errorlevel: 29e. is 1 or more.  With
‘errorlevel=0’ the error will be logged and the member will be skipped,
but extraction will continue.


File: python.info,  Node: Hints for further verification,  Next: Supporting older Python versions,  Prev: Filter errors,  Up: Extraction filters

5.13.8.6 Hints for further verification
.......................................

Even with ‘filter='data'’, 'tarfile' is not suited for extracting
untrusted files without prior inspection.  Among other issues, the
pre-defined filters do not prevent denial-of-service attacks.  Users
should do additional checks.

Here is an incomplete list of things to consider:

   * Extract to a *note new temporary directory: 52e. to prevent e.g.
     exploiting pre-existing links, and to make it easier to clean up
     after a failed extraction.

   * Disallow symbolic links if you do not need the functionality.

   * When working with untrusted data, use external (e.g.  OS-level)
     limits on disk, memory and CPU usage.

   * Check filenames against an allow-list of characters (to filter out
     control characters, confusables, foreign path separators, and so
     on).

   * Check that filenames have expected extensions (discouraging files
     that execute when you “click on them”, or extension-less files like
     Windows special device names).

   * Limit the number of extracted files, total size of extracted data,
     filename length (including symlink length), and size of individual
     files.

   * Check for files that would be shadowed on case-insensitive
     filesystems.

Also note that:

   * Tar files may contain multiple versions of the same file.  Later
     ones are expected to overwrite any earlier ones.  This feature is
     crucial to allow updating tape archives, but can be abused
     maliciously.

   * 'tarfile' does not protect against issues with “live” data, e.g.
     an attacker tinkering with the destination (or source) directory
     while extraction (or archiving) is in progress.


File: python.info,  Node: Supporting older Python versions,  Next: Stateful extraction filter example,  Prev: Hints for further verification,  Up: Extraction filters

5.13.8.7 Supporting older Python versions
.........................................

Extraction filters were added to Python 3.12, but may be backported to
older versions as security updates.  To check whether the feature is
available, use e.g.  ‘hasattr(tarfile, 'data_filter')’ rather than
checking the Python version.

The following examples show how to support Python versions with and
without the feature.  Note that setting ‘extraction_filter’ will affect
any subsequent operations.

   * Fully trusted archive:

          my_tarfile.extraction_filter = (lambda member, path: member)
          my_tarfile.extractall()

   * Use the ‘'data'’ filter if available, but revert to Python 3.11
     behavior (‘'fully_trusted'’) if this feature is not available:

          my_tarfile.extraction_filter = getattr(tarfile, 'data_filter',
                                                 (lambda member, path: member))
          my_tarfile.extractall()

   * Use the ‘'data'’ filter; 'fail' if it is not available:

          my_tarfile.extractall(filter=tarfile.data_filter)

     or:

          my_tarfile.extraction_filter = tarfile.data_filter
          my_tarfile.extractall()

   * Use the ‘'data'’ filter; 'warn' if it is not available:

          if hasattr(tarfile, 'data_filter'):
              my_tarfile.extractall(filter='data')
          else:
              # remove this when no longer needed
              warn_the_user('Extracting may be unsafe; consider updating Python')
              my_tarfile.extractall()


File: python.info,  Node: Stateful extraction filter example,  Prev: Supporting older Python versions,  Up: Extraction filters

5.13.8.8 Stateful extraction filter example
...........................................

While 'tarfile'’s extraction methods take a simple 'filter' callable,
custom filters may be more complex objects with an internal state.  It
may be useful to write these as context managers, to be used like this:

     with StatefulFilter() as filter_func:
         tar.extractall(path, filter=filter_func)

Such a filter can be written as, for example:

     class StatefulFilter:
         def __init__(self):
             self.file_count = 0

         def __enter__(self):
             return self

         def __call__(self, member, path):
             self.file_count += 1
             return member

         def __exit__(self, *exc_info):
             print(f'{self.file_count} files extracted')


File: python.info,  Node: Command-Line Interface,  Next: Examples<10>,  Prev: Extraction filters,  Up: tarfile — Read and write tar archive files

5.13.8.9 Command-Line Interface
...............................

Added in version 3.4.

The *note tarfile: e4. module provides a simple command-line interface
to interact with tar archives.

If you want to create a new tar archive, specify its name after the
*note -c: 2f19. option and then list the filename(s) that should be
included:

     $ python -m tarfile -c monty.tar  spam.txt eggs.txt

Passing a directory is also acceptable:

     $ python -m tarfile -c monty.tar life-of-brian_1979/

If you want to extract a tar archive into the current directory, use the
*note -e: 2f1a. option:

     $ python -m tarfile -e monty.tar

You can also extract a tar archive into a different directory by passing
the directory’s name:

     $ python -m tarfile -e monty.tar  other-dir/

For a list of the files in a tar archive, use the *note -l: 2f1b.
option:

     $ python -m tarfile -l monty.tar

* Menu:

* Command-line options: Command-line options<3>.


File: python.info,  Node: Command-line options<3>,  Up: Command-Line Interface

5.13.8.10 Command-line options
..............................

 -- Option: -l <tarfile>
 -- Option: --list <tarfile>

     List files in a tarfile.

 -- Option: -c <tarfile> <source1> ... <sourceN>
 -- Option: --create <tarfile> <source1> ... <sourceN>

     Create tarfile from source files.

 -- Option: -e <tarfile> [<output_dir>]
 -- Option: --extract <tarfile> [<output_dir>]

     Extract tarfile into the current directory if 'output_dir' is not
     specified.

 -- Option: -t <tarfile>
 -- Option: --test <tarfile>

     Test whether the tarfile is valid or not.

 -- Option: -v, --verbose

     Verbose output.

 -- Option: --filter <filtername>

     Specifies the 'filter' for ‘--extract’.  See *note Extraction
     filters: 698. for details.  Only string names are accepted (that
     is, ‘fully_trusted’, ‘tar’, and ‘data’).


File: python.info,  Node: Examples<10>,  Next: Supported tar formats,  Prev: Command-Line Interface,  Up: tarfile — Read and write tar archive files

5.13.8.11 Examples
..................

* Menu:

* Reading examples::
* Writing examples::


File: python.info,  Node: Reading examples,  Next: Writing examples,  Up: Examples<10>

5.13.8.12 Reading examples
..........................

How to extract an entire tar archive to the current working directory:

     import tarfile
     tar = tarfile.open("sample.tar.gz")
     tar.extractall(filter='data')
     tar.close()

How to extract a subset of a tar archive with *note
TarFile.extractall(): 29b. using a generator function instead of a list:

     import os
     import tarfile

     def py_files(members):
         for tarinfo in members:
             if os.path.splitext(tarinfo.name)[1] == ".py":
                 yield tarinfo

     tar = tarfile.open("sample.tar.gz")
     tar.extractall(members=py_files(tar))
     tar.close()

How to read a gzip compressed tar archive and display some member
information:

     import tarfile
     tar = tarfile.open("sample.tar.gz", "r:gz")
     for tarinfo in tar:
         print(tarinfo.name, "is", tarinfo.size, "bytes in size and is ", end="")
         if tarinfo.isreg():
             print("a regular file.")
         elif tarinfo.isdir():
             print("a directory.")
         else:
             print("something else.")
     tar.close()


File: python.info,  Node: Writing examples,  Prev: Reading examples,  Up: Examples<10>

5.13.8.13 Writing examples
..........................

How to create an uncompressed tar archive from a list of filenames:

     import tarfile
     tar = tarfile.open("sample.tar", "w")
     for name in ["foo", "bar", "quux"]:
         tar.add(name)
     tar.close()

The same example using the *note with: 186. statement:

     import tarfile
     with tarfile.open("sample.tar", "w") as tar:
         for name in ["foo", "bar", "quux"]:
             tar.add(name)

How to create and write an archive to stdout using *note
sys.stdout.buffer: ccf. in the 'fileobj' parameter in *note
TarFile.add(): df0.:

     import sys
     import tarfile
     with tarfile.open("sample.tar.gz", "w|gz", fileobj=sys.stdout.buffer) as tar:
         for name in ["foo", "bar", "quux"]:
             tar.add(name)

How to create an archive and reset the user information using the
'filter' parameter in *note TarFile.add(): df0.:

     import tarfile
     def reset(tarinfo):
         tarinfo.uid = tarinfo.gid = 0
         tarinfo.uname = tarinfo.gname = "root"
         return tarinfo
     tar = tarfile.open("sample.tar.gz", "w:gz")
     tar.add("foo", filter=reset)
     tar.close()


File: python.info,  Node: Supported tar formats,  Next: Unicode issues,  Prev: Examples<10>,  Up: tarfile — Read and write tar archive files

5.13.8.14 Supported tar formats
...............................

There are three tar formats that can be created with the *note tarfile:
e4. module:

   * The POSIX.1-1988 ustar format (*note USTAR_FORMAT: 2ee5.).  It
     supports filenames up to a length of at best 256 characters and
     linknames up to 100 characters.  The maximum file size is 8 GiB.
     This is an old and limited but widely supported format.

   * The GNU tar format (*note GNU_FORMAT: 2ee6.).  It supports long
     filenames and linknames, files bigger than 8 GiB and sparse files.
     It is the de facto standard on GNU/Linux systems.  *note tarfile:
     e4. fully supports the GNU tar extensions for long names, sparse
     file support is read-only.

   * The POSIX.1-2001 pax format (*note PAX_FORMAT: 2ee7.).  It is the
     most flexible format with virtually no limits.  It supports long
     filenames and linknames, large files and stores pathnames in a
     portable way.  Modern tar implementations, including GNU tar,
     bsdtar/libarchive and star, fully support extended 'pax' features;
     some old or unmaintained libraries may not, but should treat 'pax'
     archives as if they were in the universally supported 'ustar'
     format.  It is the current default format for new archives.

     It extends the existing 'ustar' format with extra headers for
     information that cannot be stored otherwise.  There are two
     flavours of pax headers: Extended headers only affect the
     subsequent file header, global headers are valid for the complete
     archive and affect all following files.  All the data in a pax
     header is encoded in 'UTF-8' for portability reasons.

There are some more variants of the tar format which can be read, but
not created:

   * The ancient V7 format.  This is the first tar format from Unix
     Seventh Edition, storing only regular files and directories.  Names
     must not be longer than 100 characters, there is no user/group name
     information.  Some archives have miscalculated header checksums in
     case of fields with non-ASCII characters.

   * The SunOS tar extended format.  This format is a variant of the
     POSIX.1-2001 pax format, but is not compatible.


File: python.info,  Node: Unicode issues,  Prev: Supported tar formats,  Up: tarfile — Read and write tar archive files

5.13.8.15 Unicode issues
........................

The tar format was originally conceived to make backups on tape drives
with the main focus on preserving file system information.  Nowadays tar
archives are commonly used for file distribution and exchanging archives
over networks.  One problem of the original format (which is the basis
of all other formats) is that there is no concept of supporting
different character encodings.  For example, an ordinary tar archive
created on a 'UTF-8' system cannot be read correctly on a 'Latin-1'
system if it contains non-'ASCII' characters.  Textual metadata (like
filenames, linknames, user/group names) will appear damaged.
Unfortunately, there is no way to autodetect the encoding of an archive.
The pax format was designed to solve this problem.  It stores non-ASCII
metadata using the universal character encoding 'UTF-8'.

The details of character conversion in *note tarfile: e4. are controlled
by the 'encoding' and 'errors' keyword arguments of the *note TarFile:
1418. class.

'encoding' defines the character encoding to use for the metadata in the
archive.  The default value is *note sys.getfilesystemencoding(): e55.
or ‘'ascii'’ as a fallback.  Depending on whether the archive is read or
written, the metadata must be either decoded or encoded.  If 'encoding'
is not set appropriately, this conversion may fail.

The 'errors' argument defines how characters are treated that cannot be
converted.  Possible values are listed in section *note Error Handlers:
1b57.  The default scheme is ‘'surrogateescape'’ which Python also uses
for its file system calls, see *note File Names, Command Line Arguments,
and Environment Variables: 2f2a.

For *note PAX_FORMAT: 2ee7. archives (the default), 'encoding' is
generally not needed because all the metadata is stored using 'UTF-8'.
'encoding' is only used in the rare cases when binary pax headers are
decoded or when strings with surrogate characters are stored.


File: python.info,  Node: File Formats,  Next: Cryptographic Services,  Prev: Data Compression and Archiving,  Up: The Python Standard Library

5.14 File Formats
=================

The modules described in this chapter parse various miscellaneous file
formats that aren’t markup languages and are not related to e-mail.

* Menu:

* csv — CSV File Reading and Writing::
* configparser — Configuration file parser::
* tomllib — Parse TOML files::
* netrc — netrc file processing::
* plistlib — Generate and parse Apple .plist files: plistlib — Generate and parse Apple plist files.


File: python.info,  Node: csv — CSV File Reading and Writing,  Next: configparser — Configuration file parser,  Up: File Formats

5.14.1 ‘csv’ — CSV File Reading and Writing
-------------------------------------------

'Source code:' Lib/csv.py(1)

__________________________________________________________________

The so-called CSV (Comma Separated Values) format is the most common
import and export format for spreadsheets and databases.  CSV format was
used for many years prior to attempts to describe the format in a
standardized way in RFC 4180(2).  The lack of a well-defined standard
means that subtle differences often exist in the data produced and
consumed by different applications.  These differences can make it
annoying to process CSV files from multiple sources.  Still, while the
delimiters and quoting characters vary, the overall format is similar
enough that it is possible to write a single module which can
efficiently manipulate such data, hiding the details of reading and
writing the data from the programmer.

The *note csv: 2d. module implements classes to read and write tabular
data in CSV format.  It allows programmers to say, «write this data in
the format preferred by Excel,» or «read data from this file which was
generated by Excel,» without knowing the precise details of the CSV
format used by Excel.  Programmers can also describe the CSV formats
understood by other applications or define their own special-purpose CSV
formats.

The *note csv: 2d. module’s *note reader: 6af. and *note writer: 6b0.
objects read and write sequences.  Programmers can also read and write
data in dictionary form using the *note DictReader: bda. and *note
DictWriter: 1406. classes.

Vedi anche
..........

PEP 305(3) - CSV File API

     The Python Enhancement Proposal which proposed this addition to
     Python.

* Menu:

* Module Contents: Module Contents<3>.
* Dialects and Formatting Parameters::
* Reader Objects::
* Writer Objects::
* Examples: Examples<11>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/csv.py

   (2) https://datatracker.ietf.org/doc/html/rfc4180.html

   (3) https://peps.python.org/pep-0305/


File: python.info,  Node: Module Contents<3>,  Next: Dialects and Formatting Parameters,  Up: csv — CSV File Reading and Writing

5.14.1.1 Module Contents
........................

The *note csv: 2d. module defines the following functions:

 -- Funzione: csv.reader (csvfile, /, dialect='excel', **fmtparams)

     Return a *note reader object: 2f33. that will process lines from
     the given 'csvfile'.  A csvfile must be an iterable of strings,
     each in the reader’s defined csv format.  A csvfile is most
     commonly a file-like object or list.  If 'csvfile' is a file
     object, it should be opened with ‘newline=''’.  (1)  An optional
     'dialect' parameter can be given which is used to define a set of
     parameters specific to a particular CSV dialect.  It may be an
     instance of a subclass of the *note Dialect: 180f. class or one of
     the strings returned by the *note list_dialects(): 1b7c. function.
     The other optional 'fmtparams' keyword arguments can be given to
     override individual formatting parameters in the current dialect.
     For full details about the dialect and formatting parameters, see
     section *note Dialects and Formatting Parameters: 2f34.

     Each row read from the csv file is returned as a list of strings.
     No automatic data type conversion is performed unless the *note
     QUOTE_NONNUMERIC: 192f. format option is specified (in which case
     unquoted fields are transformed into floats).

     A short usage example:

          >>> import csv
          >>> with open('eggs.csv', newline='') as csvfile:
          ...     spamreader = csv.reader(csvfile, delimiter=' ', quotechar='|')
          ...     for row in spamreader:
          ...         print(', '.join(row))
          Spam, Spam, Spam, Spam, Spam, Baked Beans
          Spam, Lovely Spam, Wonderful Spam

 -- Funzione: csv.writer (csvfile, /, dialect='excel', **fmtparams)

     Return a writer object responsible for converting the user’s data
     into delimited strings on the given file-like object.  'csvfile'
     can be any object with a *note write(): 2045. method.  If 'csvfile'
     is a file object, it should be opened with ‘newline=''’ (2).  An
     optional 'dialect' parameter can be given which is used to define a
     set of parameters specific to a particular CSV dialect.  It may be
     an instance of a subclass of the *note Dialect: 180f. class or one
     of the strings returned by the *note list_dialects(): 1b7c.
     function.  The other optional 'fmtparams' keyword arguments can be
     given to override individual formatting parameters in the current
     dialect.  For full details about dialects and formatting
     parameters, see the *note Dialects and Formatting Parameters: 2f34.
     section.  To make it as easy as possible to interface with modules
     which implement the DB API, the value *note None: 886. is written
     as the empty string.  While this isn’t a reversible transformation,
     it makes it easier to dump SQL NULL data values to CSV files
     without preprocessing the data returned from a ‘cursor.fetch*’
     call.  All other non-string data are stringified with *note str():
     169. before being written.

     A short usage example:

          import csv
          with open('eggs.csv', 'w', newline='') as csvfile:
              spamwriter = csv.writer(csvfile, delimiter=' ',
                                      quotechar='|', quoting=csv.QUOTE_MINIMAL)
              spamwriter.writerow(['Spam'] * 5 + ['Baked Beans'])
              spamwriter.writerow(['Spam', 'Lovely Spam', 'Wonderful Spam'])

 -- Funzione: csv.register_dialect (name, /, dialect='excel',
          **fmtparams)

     Associate 'dialect' with 'name'.  'name' must be a string.  The
     dialect can be specified either by passing a sub-class of *note
     Dialect: 180f, or by 'fmtparams' keyword arguments, or both, with
     keyword arguments overriding parameters of the dialect.  For full
     details about dialects and formatting parameters, see section *note
     Dialects and Formatting Parameters: 2f34.

 -- Funzione: csv.unregister_dialect (name)

     Delete the dialect associated with 'name' from the dialect
     registry.  An *note Error: 2f35. is raised if 'name' is not a
     registered dialect name.

 -- Funzione: csv.get_dialect (name)

     Return the dialect associated with 'name'.  An *note Error: 2f35.
     is raised if 'name' is not a registered dialect name.  This
     function returns an immutable *note Dialect: 180f.

 -- Funzione: csv.list_dialects ()

     Return the names of all registered dialects.

 -- Funzione: csv.field_size_limit ()

 -- Funzione: csv.field_size_limit (new_limit)

     Returns the current maximum field size allowed by the parser.  If
     'new_limit' is given, this becomes the new limit.

The *note csv: 2d. module defines the following classes:

 -- Classe: csv.DictReader (f, fieldnames=None, restkey=None,
          restval=None, dialect='excel', *args, **kwds)

     Create an object that operates like a regular reader but maps the
     information in each row to a *note dict: 183. whose keys are given
     by the optional 'fieldnames' parameter.

     The 'fieldnames' parameter is a *note sequence: 717.  If
     'fieldnames' is omitted, the values in the first row of file 'f'
     will be used as the fieldnames and will be omitted from the
     results.  If 'fieldnames' is provided, they will be used and the
     first row will be included in the results.  Regardless of how the
     fieldnames are determined, the dictionary preserves their original
     ordering.

     If a row has more fields than fieldnames, the remaining data is put
     in a list and stored with the fieldname specified by 'restkey'
     (which defaults to ‘None’).  If a non-blank row has fewer fields
     than fieldnames, the missing values are filled-in with the value of
     'restval' (which defaults to ‘None’).

     All other optional or keyword arguments are passed to the
     underlying *note reader: 6af. instance.

     If the argument passed to 'fieldnames' is an iterator, it will be
     coerced to a *note list: 24d.

     Cambiato nella versione 3.6: Returned rows are now of type
     ‘OrderedDict’.

     Cambiato nella versione 3.8: Returned rows are now of type *note
     dict: 183.

     A short usage example:

          >>> import csv
          >>> with open('names.csv', newline='') as csvfile:
          ...     reader = csv.DictReader(csvfile)
          ...     for row in reader:
          ...         print(row['first_name'], row['last_name'])
          ...
          Eric Idle
          John Cleese

          >>> print(row)
          {'first_name': 'John', 'last_name': 'Cleese'}

 -- Classe: csv.DictWriter (f, fieldnames, restval='',
          extrasaction='raise', dialect='excel', *args, **kwds)

     Create an object which operates like a regular writer but maps
     dictionaries onto output rows.  The 'fieldnames' parameter is a
     *note sequence: 1f. of keys that identify the order in which values
     in the dictionary passed to the *note writerow(): feb. method are
     written to file 'f'.  The optional 'restval' parameter specifies
     the value to be written if the dictionary is missing a key in
     'fieldnames'.  If the dictionary passed to the *note writerow():
     feb. method contains a key not found in 'fieldnames', the optional
     'extrasaction' parameter indicates what action to take.  If it is
     set to ‘'raise'’, the default value, a *note ValueError: 2ec. is
     raised.  If it is set to ‘'ignore'’, extra values in the dictionary
     are ignored.  Any other optional or keyword arguments are passed to
     the underlying *note writer: 6b0. instance.

     Note that unlike the *note DictReader: bda. class, the 'fieldnames'
     parameter of the *note DictWriter: 1406. class is not optional.

     If the argument passed to 'fieldnames' is an iterator, it will be
     coerced to a *note list: 24d.

     A short usage example:

          import csv

          with open('names.csv', 'w', newline='') as csvfile:
              fieldnames = ['first_name', 'last_name']
              writer = csv.DictWriter(csvfile, fieldnames=fieldnames)

              writer.writeheader()
              writer.writerow({'first_name': 'Baked', 'last_name': 'Beans'})
              writer.writerow({'first_name': 'Lovely', 'last_name': 'Spam'})
              writer.writerow({'first_name': 'Wonderful', 'last_name': 'Spam'})

 -- Classe: csv.Dialect

     The *note Dialect: 180f. class is a container class whose
     attributes contain information for how to handle doublequotes,
     whitespace, delimiters, etc.  Due to the lack of a strict CSV
     specification, different applications produce subtly different CSV
     data.  *note Dialect: 180f. instances define how *note reader: 6af.
     and *note writer: 6b0. instances behave.

     All available *note Dialect: 180f. names are returned by *note
     list_dialects(): 1b7c, and they can be registered with specific
     *note reader: 6af. and *note writer: 6b0. classes through their
     initializer (‘__init__’) functions like this:

          import csv

          with open('students.csv', 'w', newline='') as csvfile:
              writer = csv.writer(csvfile, dialect='unix')

 -- Classe: csv.excel

     The *note excel: 2f36. class defines the usual properties of an
     Excel-generated CSV file.  It is registered with the dialect name
     ‘'excel'’.

 -- Classe: csv.excel_tab

     The *note excel_tab: 2f37. class defines the usual properties of an
     Excel-generated TAB-delimited file.  It is registered with the
     dialect name ‘'excel-tab'’.

 -- Classe: csv.unix_dialect

     The *note unix_dialect: 1405. class defines the usual properties of
     a CSV file generated on UNIX systems, i.e.  using ‘'\n'’ as line
     terminator and quoting all fields.  It is registered with the
     dialect name ‘'unix'’.

     Added in version 3.2.

 -- Classe: csv.Sniffer

     The *note Sniffer: 2f38. class is used to deduce the format of a
     CSV file.

     The *note Sniffer: 2f38. class provides two methods:

      -- Metodo: sniff (sample, delimiters=None)

          Analyze the given 'sample' and return a *note Dialect: 180f.
          subclass reflecting the parameters found.  If the optional
          'delimiters' parameter is given, it is interpreted as a string
          containing possible valid delimiter characters.

      -- Metodo: has_header (sample)

          Analyze the sample text (presumed to be in CSV format) and
          return *note True: e09. if the first row appears to be a
          series of column headers.  Inspecting each column, one of two
          key criteria will be considered to estimate if the sample
          contains a header:

             - the second through n-th rows contain numeric values

             - the second through n-th rows contain strings where at
               least one value’s length differs from that of the
               putative header of that column.

          Twenty-one rows after the header are sampled; if more than
          half of the columns + rows meet the criteria, *note True: e09.
          is returned.

          Nota: This method is a rough heuristic and may produce both
          false positives and negatives.

An example for *note Sniffer: 2f38. use:

     with open('example.csv', newline='') as csvfile:
         dialect = csv.Sniffer().sniff(csvfile.read(1024))
         csvfile.seek(0)
         reader = csv.reader(csvfile, dialect)
         # ... process CSV file contents here ...
The *note csv: 2d. module defines the following constants:

 -- Dati: csv.QUOTE_ALL

     Instructs *note writer: 6b0. objects to quote all fields.

 -- Dati: csv.QUOTE_MINIMAL

     Instructs *note writer: 6b0. objects to only quote those fields
     which contain special characters such as 'delimiter', 'quotechar',
     ‘'\r'’, ‘'\n'’ or any of the characters in 'lineterminator'.

 -- Dati: csv.QUOTE_NONNUMERIC

     Instructs *note writer: 6b0. objects to quote all non-numeric
     fields.

     Instructs *note reader: 6af. objects to convert all non-quoted
     fields to type *note float: 196.

          Nota: Some numeric types, such as *note bool: 3c3, *note
          Fraction: 213, or *note IntEnum: edd, have a string
          representation that cannot be converted to *note float: 196.
          They cannot be read in the *note QUOTE_NONNUMERIC: 192f. and
          *note QUOTE_STRINGS: 6ae. modes.

 -- Dati: csv.QUOTE_NONE

     Instructs *note writer: 6b0. objects to never quote fields.  When
     the current 'delimiter', 'quotechar', 'escapechar', ‘'\r'’, ‘'\n'’
     or any of the characters in 'lineterminator' occurs in output data
     it is preceded by the current 'escapechar' character.  If
     'escapechar' is not set, the writer will raise *note Error: 2f35.
     if any characters that require escaping are encountered.  Set
     'quotechar' to ‘None’ to prevent its escaping.

     Instructs *note reader: 6af. objects to perform no special
     processing of quote characters.

 -- Dati: csv.QUOTE_NOTNULL

     Instructs *note writer: 6b0. objects to quote all fields which are
     not ‘None’.  This is similar to *note QUOTE_ALL: 2f3b, except that
     if a field value is ‘None’ an empty (unquoted) string is written.

     Instructs *note reader: 6af. objects to interpret an empty
     (unquoted) field as ‘None’ and to otherwise behave as *note
     QUOTE_ALL: 2f3b.

     Added in version 3.12.

 -- Dati: csv.QUOTE_STRINGS

     Instructs *note writer: 6b0. objects to always place quotes around
     fields which are strings.  This is similar to *note
     QUOTE_NONNUMERIC: 192f, except that if a field value is ‘None’ an
     empty (unquoted) string is written.

     Instructs *note reader: 6af. objects to interpret an empty
     (unquoted) string as ‘None’ and to otherwise behave as *note
     QUOTE_NONNUMERIC: 192f.

     Added in version 3.12.

The *note csv: 2d. module defines the following exception:

 -- Eccezione: csv.Error

     Raised by any of the functions when an error is detected.

   ---------- Footnotes ----------

   (1) If ‘newline=''’ is not specified, newlines embedded inside quoted
fields will not be interpreted correctly, and on platforms that use
‘\r\n’ line endings on write an extra ‘\r’ will be added.  It should
always be safe to specify ‘newline=''’, since the csv module does its
own (*note universal: f37.) newline handling.

   (2) If ‘newline=''’ is not specified, newlines embedded inside quoted
fields will not be interpreted correctly, and on platforms that use
‘\r\n’ line endings on write an extra ‘\r’ will be added.  It should
always be safe to specify ‘newline=''’, since the csv module does its
own (*note universal: f37.) newline handling.


File: python.info,  Node: Dialects and Formatting Parameters,  Next: Reader Objects,  Prev: Module Contents<3>,  Up: csv — CSV File Reading and Writing

5.14.1.2 Dialects and Formatting Parameters
...........................................

To make it easier to specify the format of input and output records,
specific formatting parameters are grouped together into dialects.  A
dialect is a subclass of the *note Dialect: 180f. class containing
various attributes describing the format of the CSV file.  When creating
*note reader: 6af. or *note writer: 6b0. objects, the programmer can
specify a string or a subclass of the *note Dialect: 180f. class as the
dialect parameter.  In addition to, or instead of, the 'dialect'
parameter, the programmer can also specify individual formatting
parameters, which have the same names as the attributes defined below
for the *note Dialect: 180f. class.

Dialects support the following attributes:

 -- Attributo: Dialect.delimiter

     A one-character string used to separate fields.  It defaults to
     ‘','’.

 -- Attributo: Dialect.doublequote

     Controls how instances of 'quotechar' appearing inside a field
     should themselves be quoted.  When *note True: e09, the character
     is doubled.  When *note False: d2d, the 'escapechar' is used as a
     prefix to the 'quotechar'.  It defaults to *note True: e09.

     On output, if 'doublequote' is *note False: d2d. and no
     'escapechar' is set, *note Error: 2f35. is raised if a 'quotechar'
     is found in a field.

 -- Attributo: Dialect.escapechar

     A one-character string used by the writer to escape characters that
     require escaping:

             * the 'delimiter', the 'quotechar', ‘'\r'’, ‘'\n'’ and any
               of the characters in 'lineterminator' are escaped if
               'quoting' is set to *note QUOTE_NONE: 2f3d.;

             * the 'quotechar' is escaped if 'doublequote' is *note
               False: d2d.;

             * the 'escapechar' itself.

     On reading, the 'escapechar' removes any special meaning from the
     following character.  It defaults to *note None: 886, which
     disables escaping.

     Cambiato nella versione 3.11: An empty 'escapechar' is not allowed.

 -- Attributo: Dialect.lineterminator

     The string used to terminate lines produced by the *note writer:
     6b0.  It defaults to ‘'\r\n'’.

          Nota: The *note reader: 6af. is hard-coded to recognise either
          ‘'\r'’ or ‘'\n'’ as end-of-line, and ignores 'lineterminator'.
          This behavior may change in the future.

 -- Attributo: Dialect.quotechar

     A one-character string used to quote fields containing special
     characters, such as the 'delimiter' or the 'quotechar', or which
     contain new-line characters (‘'\r'’, ‘'\n'’ or any of the
     characters in 'lineterminator').  It defaults to ‘'"'’.  Can be set
     to ‘None’ to prevent escaping ‘'"'’ if 'quoting' is set to *note
     QUOTE_NONE: 2f3d.

     Cambiato nella versione 3.11: An empty 'quotechar' is not allowed.

 -- Attributo: Dialect.quoting

     Controls when quotes should be generated by the writer and
     recognised by the reader.  It can take on any of the *note QUOTE_*
     constants: 2f3a. and defaults to *note QUOTE_MINIMAL: 2f3c. if
     'quotechar' is not ‘None’, and *note QUOTE_NONE: 2f3d. otherwise.

 -- Attributo: Dialect.skipinitialspace

     When *note True: e09, spaces immediately following the 'delimiter'
     are ignored.  The default is *note False: d2d.  When combining
     ‘delimiter=' '’ with ‘skipinitialspace=True’, unquoted empty fields
     are not allowed.

 -- Attributo: Dialect.strict

     When ‘True’, raise exception *note Error: 2f35. on bad CSV input.
     The default is ‘False’.


File: python.info,  Node: Reader Objects,  Next: Writer Objects,  Prev: Dialects and Formatting Parameters,  Up: csv — CSV File Reading and Writing

5.14.1.3 Reader Objects
.......................

Reader objects (*note DictReader: bda. instances and objects returned by
the *note reader(): 6af. function) have the following public methods:

 -- Metodo: csvreader.__next__ ()

     Return the next row of the reader’s iterable object as a list (if
     the object was returned from *note reader(): 6af.) or a dict (if it
     is a *note DictReader: bda. instance), parsed according to the
     current *note Dialect: 180f.  Usually you should call this as
     ‘next(reader)’.

Reader objects have the following public attributes:

 -- Attributo: csvreader.dialect

     A read-only description of the dialect in use by the parser.

 -- Attributo: csvreader.line_num

     The number of lines read from the source iterator.  This is not the
     same as the number of records returned, as records can span
     multiple lines.

DictReader objects have the following public attribute:

 -- Attributo: DictReader.fieldnames

     If not passed as a parameter when creating the object, this
     attribute is initialized upon first access or when the first record
     is read from the file.


File: python.info,  Node: Writer Objects,  Next: Examples<11>,  Prev: Reader Objects,  Up: csv — CSV File Reading and Writing

5.14.1.4 Writer Objects
.......................

*note writer: 6b0. objects (*note DictWriter: 1406. instances and
objects returned by the *note writer(): 6b0. function) have the
following public methods.  A 'row' must be an iterable of strings or
numbers for *note writer: 6b0. objects and a dictionary mapping
fieldnames to strings or numbers (by passing them through *note str():
169. first) for *note DictWriter: 1406. objects.  Note that complex
numbers are written out surrounded by parens.  This may cause some
problems for other programs which read CSV files (assuming they support
complex numbers at all).

 -- Metodo: csvwriter.writerow (row, /)

     Write the 'row' parameter to the writer’s file object, formatted
     according to the current *note Dialect: 180f.  Return the return
     value of the call to the 'write' method of the underlying file
     object.

     Cambiato nella versione 3.5: Added support of arbitrary iterables.

 -- Metodo: csvwriter.writerows (rows, /)

     Write all elements in 'rows' (an iterable of 'row' objects as
     described above) to the writer’s file object, formatted according
     to the current dialect.

Writer objects have the following public attribute:

 -- Attributo: csvwriter.dialect

     A read-only description of the dialect in use by the writer.

DictWriter objects have the following public method:

 -- Metodo: DictWriter.writeheader ()

     Write a row with the field names (as specified in the constructor)
     to the writer’s file object, formatted according to the current
     dialect.  Return the return value of the *note
     csvwriter.writerow(): feb. call used internally.

     Added in version 3.2.

     Cambiato nella versione 3.8: *note writeheader(): 1407. now also
     returns the value returned by the *note csvwriter.writerow(): feb.
     method it uses internally.


File: python.info,  Node: Examples<11>,  Prev: Writer Objects,  Up: csv — CSV File Reading and Writing

5.14.1.5 Examples
.................

The simplest example of reading a CSV file:

     import csv
     with open('some.csv', newline='') as f:
         reader = csv.reader(f)
         for row in reader:
             print(row)

Reading a file with an alternate format:

     import csv
     with open('passwd', newline='') as f:
         reader = csv.reader(f, delimiter=':', quoting=csv.QUOTE_NONE)
         for row in reader:
             print(row)

The corresponding simplest possible writing example is:

     import csv
     with open('some.csv', 'w', newline='') as f:
         writer = csv.writer(f)
         writer.writerows(someiterable)

Since *note open(): 316. is used to open a CSV file for reading, the
file will by default be decoded into unicode using the system default
encoding (see *note locale.getencoding(): 329.).  To decode a file using
a different encoding, use the ‘encoding’ argument of open:

     import csv
     with open('some.csv', newline='', encoding='utf-8') as f:
         reader = csv.reader(f)
         for row in reader:
             print(row)

The same applies to writing in something other than the system default
encoding: specify the encoding argument when opening the output file.

Registering a new dialect:

     import csv
     csv.register_dialect('unixpwd', delimiter=':', quoting=csv.QUOTE_NONE)
     with open('passwd', newline='') as f:
         reader = csv.reader(f, 'unixpwd')

A slightly more advanced use of the reader — catching and reporting
errors:

     import csv, sys
     filename = 'some.csv'
     with open(filename, newline='') as f:
         reader = csv.reader(f)
         try:
             for row in reader:
                 print(row)
         except csv.Error as e:
             sys.exit(f'file {filename}, line {reader.line_num}: {e}')

And while the module doesn’t directly support parsing strings, it can
easily be done:

     import csv
     for row in csv.reader(['one,two,three']):
         print(row)


File: python.info,  Node: configparser — Configuration file parser,  Next: tomllib — Parse TOML files,  Prev: csv — CSV File Reading and Writing,  Up: File Formats

5.14.2 ‘configparser’ — Configuration file parser
-------------------------------------------------

'Source code:' Lib/configparser.py(1)

__________________________________________________________________

This module provides the *note ConfigParser: 4df. class which implements
a basic configuration language which provides a structure similar to
what’s found in Microsoft Windows INI files.  You can use this to write
Python programs which can be customized by end users easily.

     Nota: This library does 'not' interpret or write the value-type
     prefixes used in the Windows Registry extended version of INI
     syntax.

Vedi anche
..........

Module *note tomllib: 102.

     TOML is a well-specified format for application configuration
     files.  It is specifically designed to be an improved version of
     INI.

Module *note shlex: c9.

     Support for creating Unix shell-like mini-languages which can also
     be used for application configuration files.

Module *note json: 86.

     The ‘json’ module implements a subset of JavaScript syntax which is
     sometimes used for configuration, but does not support comments.

* Menu:

* Quick Start::
* Supported Datatypes::
* Fallback Values::
* Supported INI File Structure::
* Unnamed Sections::
* Interpolation of values::
* Mapping Protocol Access::
* Customizing Parser Behaviour::
* Legacy API Examples::
* ConfigParser Objects::
* RawConfigParser Objects::
* Exceptions: Exceptions<8>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/configparser.py


File: python.info,  Node: Quick Start,  Next: Supported Datatypes,  Up: configparser — Configuration file parser

5.14.2.1 Quick Start
....................

Let’s take a very basic configuration file that looks like this:

     [DEFAULT]
     ServerAliveInterval = 45
     Compression = yes
     CompressionLevel = 9
     ForwardX11 = yes

     [forge.example]
     User = hg

     [topsecret.server.example]
     Port = 50022
     ForwardX11 = no

The structure of INI files is described *note in the following section:
2f55.  Essentially, the file consists of sections, each of which
contains keys with values.  *note configparser: 26. classes can read and
write such files.  Let’s start by creating the above configuration file
programmatically.

     >>> import configparser
     >>> config = configparser.ConfigParser()
     >>> config['DEFAULT'] = {'ServerAliveInterval': '45',
     ...                      'Compression': 'yes',
     ...                      'CompressionLevel': '9'}
     >>> config['forge.example'] = {}
     >>> config['forge.example']['User'] = 'hg'
     >>> config['topsecret.server.example'] = {}
     >>> topsecret = config['topsecret.server.example']
     >>> topsecret['Port'] = '50022'     # mutates the parser
     >>> topsecret['ForwardX11'] = 'no'  # same here
     >>> config['DEFAULT']['ForwardX11'] = 'yes'
     >>> with open('example.ini', 'w') as configfile:
     ...   config.write(configfile)
     ...

As you can see, we can treat a config parser much like a dictionary.
There are differences, *note outlined later: 2f56, but the behavior is
very close to what you would expect from a dictionary.

Now that we have created and saved a configuration file, let’s read it
back and explore the data it holds.

     >>> config = configparser.ConfigParser()
     >>> config.sections()
     []
     >>> config.read('example.ini')
     ['example.ini']
     >>> config.sections()
     ['forge.example', 'topsecret.server.example']
     >>> 'forge.example' in config
     True
     >>> 'python.org' in config
     False
     >>> config['forge.example']['User']
     'hg'
     >>> config['DEFAULT']['Compression']
     'yes'
     >>> topsecret = config['topsecret.server.example']
     >>> topsecret['ForwardX11']
     'no'
     >>> topsecret['Port']
     '50022'
     >>> for key in config['forge.example']:
     ...     print(key)
     user
     compressionlevel
     serveraliveinterval
     compression
     forwardx11
     >>> config['forge.example']['ForwardX11']
     'yes'

As we can see above, the API is pretty straightforward.  The only bit of
magic involves the ‘DEFAULT’ section which provides default values for
all other sections (1).  Note also that keys in sections are
case-insensitive and stored in lowercase (2).

It is possible to read several configurations into a single *note
ConfigParser: 4df, where the most recently added configuration has the
highest priority.  Any conflicting keys are taken from the more recent
configuration while the previously existing keys are retained.  The
example below reads in an ‘override.ini’ file, which will override any
conflicting keys from the ‘example.ini’ file.

     [DEFAULT]
     ServerAliveInterval = -1

     >>> config_override = configparser.ConfigParser()
     >>> config_override['DEFAULT'] = {'ServerAliveInterval': '-1'}
     >>> with open('override.ini', 'w') as configfile:
     ...     config_override.write(configfile)
     ...
     >>> config_override = configparser.ConfigParser()
     >>> config_override.read(['example.ini', 'override.ini'])
     ['example.ini', 'override.ini']
     >>> print(config_override.get('DEFAULT', 'ServerAliveInterval'))
     -1

This behaviour is equivalent to a *note ConfigParser.read(): 166f. call
with several files passed to the 'filenames' parameter.

   ---------- Footnotes ----------

   (1) Config parsers allow for heavy customization.  If you are
interested in changing the behaviour outlined by the footnote reference,
consult the *note Customizing Parser Behaviour: 2f57. section.

   (2) Config parsers allow for heavy customization.  If you are
interested in changing the behaviour outlined by the footnote reference,
consult the *note Customizing Parser Behaviour: 2f57. section.


File: python.info,  Node: Supported Datatypes,  Next: Fallback Values,  Prev: Quick Start,  Up: configparser — Configuration file parser

5.14.2.2 Supported Datatypes
............................

Config parsers do not guess datatypes of values in configuration files,
always storing them internally as strings.  This means that if you need
other datatypes, you should convert on your own:

     >>> int(topsecret['Port'])
     50022
     >>> float(topsecret['CompressionLevel'])
     9.0

Since this task is so common, config parsers provide a range of handy
getter methods to handle integers, floats and booleans.  The last one is
the most interesting because simply passing the value to ‘bool()’ would
do no good since ‘bool('False')’ is still ‘True’.  This is why config
parsers also provide *note getboolean(): 2f59.  This method is
case-insensitive and recognizes Boolean values from ‘'yes'’/‘'no'’,
‘'on'’/‘'off'’, ‘'true'’/‘'false'’ and ‘'1'’/‘'0'’ (1).  For example:

     >>> topsecret.getboolean('ForwardX11')
     False
     >>> config['forge.example'].getboolean('ForwardX11')
     True
     >>> config.getboolean('forge.example', 'Compression')
     True

Apart from *note getboolean(): 2f59, config parsers also provide
equivalent *note getint(): 2f5a. and *note getfloat(): 2f5b. methods.
You can register your own converters and customize the provided ones.
(2)

   ---------- Footnotes ----------

   (1) Config parsers allow for heavy customization.  If you are
interested in changing the behaviour outlined by the footnote reference,
consult the *note Customizing Parser Behaviour: 2f57. section.

   (2) Config parsers allow for heavy customization.  If you are
interested in changing the behaviour outlined by the footnote reference,
consult the *note Customizing Parser Behaviour: 2f57. section.


File: python.info,  Node: Fallback Values,  Next: Supported INI File Structure,  Prev: Supported Datatypes,  Up: configparser — Configuration file parser

5.14.2.3 Fallback Values
........................

As with a dictionary, you can use a section’s *note get(): 1473. method
to provide fallback values:

     >>> topsecret.get('Port')
     '50022'
     >>> topsecret.get('CompressionLevel')
     '9'
     >>> topsecret.get('Cipher')
     >>> topsecret.get('Cipher', '3des-cbc')
     '3des-cbc'

Please note that default values have precedence over fallback values.
For instance, in our example the ‘'CompressionLevel'’ key was specified
only in the ‘'DEFAULT'’ section.  If we try to get it from the section
‘'topsecret.server.example'’, we will always get the default, even if we
specify a fallback:

     >>> topsecret.get('CompressionLevel', '3')
     '9'

One more thing to be aware of is that the parser-level *note get():
1473. method provides a custom, more complex interface, maintained for
backwards compatibility.  When using this method, a fallback value can
be provided via the ‘fallback’ keyword-only argument:

     >>> config.get('forge.example', 'monster',
     ...            fallback='No such things as monsters')
     'No such things as monsters'

The same ‘fallback’ argument can be used with the *note getint(): 2f5a,
*note getfloat(): 2f5b. and *note getboolean(): 2f59. methods, for
example:

     >>> 'BatchMode' in topsecret
     False
     >>> topsecret.getboolean('BatchMode', fallback=True)
     True
     >>> config['DEFAULT']['BatchMode'] = 'no'
     >>> topsecret.getboolean('BatchMode', fallback=True)
     False


File: python.info,  Node: Supported INI File Structure,  Next: Unnamed Sections,  Prev: Fallback Values,  Up: configparser — Configuration file parser

5.14.2.4 Supported INI File Structure
.....................................

A configuration file consists of sections, each led by a ‘[section]’
header, followed by key/value entries separated by a specific string
(‘=’ or ‘:’ by default (1)).  By default, section names are case
sensitive but keys are not (2).  Leading and trailing whitespace is
removed from keys and values.  Values can be omitted if the parser is
configured to allow it (3), in which case the key/value delimiter may
also be left out.  Values can also span multiple lines, as long as they
are indented deeper than the first line of the value.  Depending on the
parser’s mode, blank lines may be treated as parts of multiline values
or ignored.

By default, a valid section name can be any string that does not contain
“\n”.  To change this, see *note ConfigParser.SECTCRE: 2f5d.

The first section name may be omitted if the parser is configured to
allow an unnamed top level section with ‘allow_unnamed_section=True’.
In this case, the keys/values may be retrieved by *note UNNAMED_SECTION:
1772. as in ‘config[UNNAMED_SECTION]’.

Configuration files may include comments, prefixed by specific
characters (‘#’ and ‘;’ by default (4)).  Comments may appear on their
own on an otherwise empty line, possibly indented.  (5)

For example:

     [Simple Values]
     key=value
     spaces in keys=allowed
     spaces in values=allowed as well
     spaces around the delimiter = obviously
     you can also use : to delimit keys from values

     [All Values Are Strings]
     values like this: 1000000
     or this: 3.14159265359
     are they treated as numbers? : no
     integers, floats and booleans are held as: strings
     can use the API to get converted values directly: true

     [Multiline Values]
     chorus: I'm a lumberjack, and I'm okay
         I sleep all night and I work all day

     [No Values]
     key_without_value
     empty string value here =

     [You can use comments]
     # like this
     ; or this

     # By default only in an empty line.
     # Inline comments can be harmful because they prevent users
     # from using the delimiting characters as parts of values.
     # That being said, this can be customized.

         [Sections Can Be Indented]
             can_values_be_as_well = True
             does_that_mean_anything_special = False
             purpose = formatting for readability
             multiline_values = are
                 handled just fine as
                 long as they are indented
                 deeper than the first line
                 of a value
             # Did I mention we can indent comments, too?

   ---------- Footnotes ----------

   (1) Config parsers allow for heavy customization.  If you are
interested in changing the behaviour outlined by the footnote reference,
consult the *note Customizing Parser Behaviour: 2f57. section.

   (2) Config parsers allow for heavy customization.  If you are
interested in changing the behaviour outlined by the footnote reference,
consult the *note Customizing Parser Behaviour: 2f57. section.

   (3) Config parsers allow for heavy customization.  If you are
interested in changing the behaviour outlined by the footnote reference,
consult the *note Customizing Parser Behaviour: 2f57. section.

   (4) Config parsers allow for heavy customization.  If you are
interested in changing the behaviour outlined by the footnote reference,
consult the *note Customizing Parser Behaviour: 2f57. section.

   (5) Config parsers allow for heavy customization.  If you are
interested in changing the behaviour outlined by the footnote reference,
consult the *note Customizing Parser Behaviour: 2f57. section.


File: python.info,  Node: Unnamed Sections,  Next: Interpolation of values,  Prev: Supported INI File Structure,  Up: configparser — Configuration file parser

5.14.2.5 Unnamed Sections
.........................

The name of the first section (or unique) may be omitted and values
retrieved by the *note UNNAMED_SECTION: 1772. attribute.

     >>> config = """
     ... option = value
     ...
     ... [  Section 2  ]
     ... another = val
     ... """
     >>> unnamed = configparser.ConfigParser(allow_unnamed_section=True)
     >>> unnamed.read_string(config)
     >>> unnamed.get(configparser.UNNAMED_SECTION, 'option')
     'value'


File: python.info,  Node: Interpolation of values,  Next: Mapping Protocol Access,  Prev: Unnamed Sections,  Up: configparser — Configuration file parser

5.14.2.6 Interpolation of values
................................

On top of the core functionality, *note ConfigParser: 4df. supports
interpolation.  This means values can be preprocessed before returning
them from ‘get()’ calls.

 -- Classe: configparser.BasicInterpolation

     The default implementation used by *note ConfigParser: 4df.  It
     enables values to contain format strings which refer to other
     values in the same section, or values in the special default
     section (1).  Additional default values can be provided on
     initialization.

     For example:

          [Paths]
          home_dir: /Users
          my_dir: %(home_dir)s/lumberjack
          my_pictures: %(my_dir)s/Pictures

          [Escape]
          # use a %% to escape the % sign (% is the only character that needs to be escaped):
          gain: 80%%

     In the example above, *note ConfigParser: 4df. with 'interpolation'
     set to ‘BasicInterpolation()’ would resolve ‘%(home_dir)s’ to the
     value of ‘home_dir’ (‘/Users’ in this case).  ‘%(my_dir)s’ in
     effect would resolve to ‘/Users/lumberjack’.  All interpolations
     are done on demand so keys used in the chain of references do not
     have to be specified in any specific order in the configuration
     file.

     With ‘interpolation’ set to ‘None’, the parser would simply return
     ‘%(my_dir)s/Pictures’ as the value of ‘my_pictures’ and
     ‘%(home_dir)s/lumberjack’ as the value of ‘my_dir’.

 -- Classe: configparser.ExtendedInterpolation

     An alternative handler for interpolation which implements a more
     advanced syntax, used for instance in ‘zc.buildout’.  Extended
     interpolation is using ‘${section:option}’ to denote a value from a
     foreign section.  Interpolation can span multiple levels.  For
     convenience, if the ‘section:’ part is omitted, interpolation
     defaults to the current section (and possibly the default values
     from the special section).

     For example, the configuration specified above with basic
     interpolation, would look like this with extended interpolation:

          [Paths]
          home_dir: /Users
          my_dir: ${home_dir}/lumberjack
          my_pictures: ${my_dir}/Pictures

          [Escape]
          # use a $$ to escape the $ sign ($ is the only character that needs to be escaped):
          cost: $$80

     Values from other sections can be fetched as well:

          [Common]
          home_dir: /Users
          library_dir: /Library
          system_dir: /System
          macports_dir: /opt/local

          [Frameworks]
          Python: 3.2
          path: ${Common:system_dir}/Library/Frameworks/

          [Arthur]
          nickname: Two Sheds
          last_name: Jackson
          my_dir: ${Common:home_dir}/twosheds
          my_pictures: ${my_dir}/Pictures
          python_dir: ${Frameworks:path}/Python/Versions/${Frameworks:Python}

   ---------- Footnotes ----------

   (1) Config parsers allow for heavy customization.  If you are
interested in changing the behaviour outlined by the footnote reference,
consult the *note Customizing Parser Behaviour: 2f57. section.


File: python.info,  Node: Mapping Protocol Access,  Next: Customizing Parser Behaviour,  Prev: Interpolation of values,  Up: configparser — Configuration file parser

5.14.2.7 Mapping Protocol Access
................................

Added in version 3.2.

Mapping protocol access is a generic name for functionality that enables
using custom objects as if they were dictionaries.  In case of *note
configparser: 26, the mapping interface implementation is using the
‘parser['section']['option']’ notation.

‘parser['section']’ in particular returns a proxy for the section’s data
in the parser.  This means that the values are not copied but they are
taken from the original parser on demand.  What’s even more important is
that when values are changed on a section proxy, they are actually
mutated in the original parser.

*note configparser: 26. objects behave as close to actual dictionaries
as possible.  The mapping interface is complete and adheres to the *note
MutableMapping: 12b4. ABC. However, there are a few differences that
should be taken into account:

   * By default, all keys in sections are accessible in a
     case-insensitive manner (1).  E.g.  ‘for option in
     parser["section"]’ yields only ‘optionxform’’ed option key names.
     This means lowercased keys by default.  At the same time, for a
     section that holds the key ‘'a'’, both expressions return ‘True’:

          "a" in parser["section"]
          "A" in parser["section"]

   * All sections include ‘DEFAULTSECT’ values as well which means that
     ‘.clear()’ on a section may not leave the section visibly empty.
     This is because default values cannot be deleted from the section
     (because technically they are not there).  If they are overridden
     in the section, deleting causes the default value to be visible
     again.  Trying to delete a default value causes a *note KeyError:
     5e7.

   * ‘DEFAULTSECT’ cannot be removed from the parser:

        * trying to delete it raises *note ValueError: 2ec,

        * ‘parser.clear()’ leaves it intact,

        * ‘parser.popitem()’ never returns it.

   * ‘parser.get(section, option, **kwargs)’ - the second argument is
     'not' a fallback value.  Note however that the section-level
     ‘get()’ methods are compatible both with the mapping protocol and
     the classic configparser API.

   * ‘parser.items()’ is compatible with the mapping protocol (returns a
     list of 'section_name', 'section_proxy' pairs including the
     DEFAULTSECT). However, this method can also be invoked with
     arguments: ‘parser.items(section, raw, vars)’.  The latter call
     returns a list of 'option', 'value' pairs for a specified
     ‘section’, with all interpolations expanded (unless ‘raw=True’ is
     provided).

The mapping protocol is implemented on top of the existing legacy API so
that subclasses overriding the original interface still should have
mappings working as expected.

   ---------- Footnotes ----------

   (1) Config parsers allow for heavy customization.  If you are
interested in changing the behaviour outlined by the footnote reference,
consult the *note Customizing Parser Behaviour: 2f57. section.


File: python.info,  Node: Customizing Parser Behaviour,  Next: Legacy API Examples,  Prev: Mapping Protocol Access,  Up: configparser — Configuration file parser

5.14.2.8 Customizing Parser Behaviour
.....................................

There are nearly as many INI format variants as there are applications
using it.  *note configparser: 26. goes a long way to provide support
for the largest sensible set of INI styles available.  The default
functionality is mainly dictated by historical background and it’s very
likely that you will want to customize some of the features.

The most common way to change the way a specific config parser works is
to use the ‘__init__()’ options:

   * 'defaults', default value: ‘None’

     This option accepts a dictionary of key-value pairs which will be
     initially put in the ‘DEFAULT’ section.  This makes for an elegant
     way to support concise configuration files that don’t specify
     values which are the same as the documented default.

     Hint: if you want to specify default values for a specific section,
     use *note read_dict(): 2f61. before you read the actual file.

   * 'dict_type', default value: *note dict: 183.

     This option has a major impact on how the mapping protocol will
     behave and how the written configuration files look.  With the
     standard dictionary, every section is stored in the order they were
     added to the parser.  Same goes for options within sections.

     An alternative dictionary type can be used for example to sort
     sections and options on write-back.

     Please note: there are ways to add a set of key-value pairs in a
     single operation.  When you use a regular dictionary in those
     operations, the order of the keys will be ordered.  For example:

          >>> parser = configparser.ConfigParser()
          >>> parser.read_dict({'section1': {'key1': 'value1',
          ...                                'key2': 'value2',
          ...                                'key3': 'value3'},
          ...                   'section2': {'keyA': 'valueA',
          ...                                'keyB': 'valueB',
          ...                                'keyC': 'valueC'},
          ...                   'section3': {'foo': 'x',
          ...                                'bar': 'y',
          ...                                'baz': 'z'}
          ... })
          >>> parser.sections()
          ['section1', 'section2', 'section3']
          >>> [option for option in parser['section3']]
          ['foo', 'bar', 'baz']

   * 'allow_no_value', default value: ‘False’

     Some configuration files are known to include settings without
     values, but which otherwise conform to the syntax supported by
     *note configparser: 26.  The 'allow_no_value' parameter to the
     constructor can be used to indicate that such values should be
     accepted:

          >>> import configparser

          >>> sample_config = """
          ... [mysqld]
          ...   user = mysql
          ...   pid-file = /var/run/mysqld/mysqld.pid
          ...   skip-external-locking
          ...   old_passwords = 1
          ...   skip-bdb
          ...   # we don't need ACID today
          ...   skip-innodb
          ... """
          >>> config = configparser.ConfigParser(allow_no_value=True)
          >>> config.read_string(sample_config)

          >>> # Settings with values are treated as before:
          >>> config["mysqld"]["user"]
          'mysql'

          >>> # Settings without values provide None:
          >>> config["mysqld"]["skip-bdb"]

          >>> # Settings which aren't specified still raise an error:
          >>> config["mysqld"]["does-not-exist"]
          Traceback (most recent call last):
            ...
          KeyError: 'does-not-exist'

   * 'delimiters', default value: ‘('=', ':')’

     Delimiters are substrings that delimit keys from values within a
     section.  The first occurrence of a delimiting substring on a line
     is considered a delimiter.  This means values (but not keys) can
     contain the delimiters.

     See also the 'space_around_delimiters' argument to *note
     ConfigParser.write(): 1de.

   * 'comment_prefixes', default value: ‘('#', ';')’

   * 'inline_comment_prefixes', default value: ‘None’

     Comment prefixes are strings that indicate the start of a valid
     comment within a config file.  'comment_prefixes' are used only on
     otherwise empty lines (optionally indented) whereas
     'inline_comment_prefixes' can be used after every valid value (e.g.
     section names, options and empty lines as well).  By default inline
     comments are disabled and ‘'#'’ and ‘';'’ are used as prefixes for
     whole line comments.

     Cambiato nella versione 3.2: In previous versions of *note
     configparser: 26. behaviour matched ‘comment_prefixes=('#',';')’
     and ‘inline_comment_prefixes=(';',)’.

     Please note that config parsers don’t support escaping of comment
     prefixes so using 'inline_comment_prefixes' may prevent users from
     specifying option values with characters used as comment prefixes.
     When in doubt, avoid setting 'inline_comment_prefixes'.  In any
     circumstances, the only way of storing comment prefix characters at
     the beginning of a line in multiline values is to interpolate the
     prefix, for example:

          >>> from configparser import ConfigParser, ExtendedInterpolation
          >>> parser = ConfigParser(interpolation=ExtendedInterpolation())
          >>> # the default BasicInterpolation could be used as well
          >>> parser.read_string("""
          ... [DEFAULT]
          ... hash = #
          ...
          ... [hashes]
          ... shebang =
          ...   ${hash}!/usr/bin/env python
          ...   ${hash} -*- coding: utf-8 -*-
          ...
          ... extensions =
          ...   enabled_extension
          ...   another_extension
          ...   #disabled_by_comment
          ...   yet_another_extension
          ...
          ... interpolation not necessary = if # is not at line start
          ... even in multiline values = line #1
          ...   line #2
          ...   line #3
          ... """)
          >>> print(parser['hashes']['shebang'])

          #!/usr/bin/env python
          # -*- coding: utf-8 -*-
          >>> print(parser['hashes']['extensions'])

          enabled_extension
          another_extension
          yet_another_extension
          >>> print(parser['hashes']['interpolation not necessary'])
          if # is not at line start
          >>> print(parser['hashes']['even in multiline values'])
          line #1
          line #2
          line #3

   * 'strict', default value: ‘True’

     When set to ‘True’, the parser will not allow for any section or
     option duplicates while reading from a single source (using *note
     read_file(): 72b, *note read_string(): 2f62. or *note read_dict():
     2f61.).  It is recommended to use strict parsers in new
     applications.

     Cambiato nella versione 3.2: In previous versions of *note
     configparser: 26. behaviour matched ‘strict=False’.

   * 'empty_lines_in_values', default value: ‘True’

     In config parsers, values can span multiple lines as long as they
     are indented more than the key that holds them.  By default parsers
     also let empty lines to be parts of values.  At the same time, keys
     can be arbitrarily indented themselves to improve readability.  In
     consequence, when configuration files get big and complex, it is
     easy for the user to lose track of the file structure.  Take for
     instance:

          [Section]
          key = multiline
            value with a gotcha

           this = is still a part of the multiline value of 'key'

     This can be especially problematic for the user to see if she’s
     using a proportional font to edit the file.  That is why when your
     application does not need values with empty lines, you should
     consider disallowing them.  This will make empty lines split keys
     every time.  In the example above, it would produce two keys, ‘key’
     and ‘this’.

   * 'default_section', default value: ‘configparser.DEFAULTSECT’ (that
     is: ‘"DEFAULT"’)

     The convention of allowing a special section of default values for
     other sections or interpolation purposes is a powerful concept of
     this library, letting users create complex declarative
     configurations.  This section is normally called ‘"DEFAULT"’ but
     this can be customized to point to any other valid section name.
     Some typical values include: ‘"general"’ or ‘"common"’.  The name
     provided is used for recognizing default sections when reading from
     any source and is used when writing configuration back to a file.
     Its current value can be retrieved using the
     ‘parser_instance.default_section’ attribute and may be modified at
     runtime (i.e.  to convert files from one format to another).

   * 'interpolation', default value: ‘configparser.BasicInterpolation’

     Interpolation behaviour may be customized by providing a custom
     handler through the 'interpolation' argument.  ‘None’ can be used
     to turn off interpolation completely, ‘ExtendedInterpolation()’
     provides a more advanced variant inspired by ‘zc.buildout’.  More
     on the subject in the *note dedicated documentation section: 2f60.
     *note RawConfigParser: 1166. has a default value of ‘None’.

   * 'converters', default value: not set

     Config parsers provide option value getters that perform type
     conversion.  By default *note getint(): 2f5a, *note getfloat():
     2f5b, and *note getboolean(): 2f59. are implemented.  Should other
     getters be desirable, users may define them in a subclass or pass a
     dictionary where each key is a name of the converter and each value
     is a callable implementing said conversion.  For instance, passing
     ‘{'decimal': decimal.Decimal}’ would add ‘getdecimal()’ on both the
     parser object and all section proxies.  In other words, it will be
     possible to write both ‘parser_instance.getdecimal('section',
     'key', fallback=0)’ and
     ‘parser_instance['section'].getdecimal('key', 0)’.

     If the converter needs to access the state of the parser, it can be
     implemented as a method on a config parser subclass.  If the name
     of this method starts with ‘get’, it will be available on all
     section proxies, in the dict-compatible form (see the
     ‘getdecimal()’ example above).

More advanced customization may be achieved by overriding default values
of these parser attributes.  The defaults are defined on the classes, so
they may be overridden by subclasses or by attribute assignment.

 -- Attributo: ConfigParser.BOOLEAN_STATES

     By default when using *note getboolean(): 2f59, config parsers
     consider the following values ‘True’: ‘'1'’, ‘'yes'’, ‘'true'’,
     ‘'on'’ and the following values ‘False’: ‘'0'’, ‘'no'’, ‘'false'’,
     ‘'off'’.  You can override this by specifying a custom dictionary
     of strings and their Boolean outcomes.  For example:

          >>> custom = configparser.ConfigParser()
          >>> custom['section1'] = {'funky': 'nope'}
          >>> custom['section1'].getboolean('funky')
          Traceback (most recent call last):
          ...
          ValueError: Not a boolean: nope
          >>> custom.BOOLEAN_STATES = {'sure': True, 'nope': False}
          >>> custom['section1'].getboolean('funky')
          False

     Other typical Boolean pairs include ‘accept’/‘reject’ or
     ‘enabled’/‘disabled’.

 -- Metodo: ConfigParser.optionxform (option)

     This method transforms option names on every read, get, or set
     operation.  The default converts the name to lowercase.  This also
     means that when a configuration file gets written, all keys will be
     lowercase.  Override this method if that’s unsuitable.  For
     example:

          >>> config = """
          ... [Section1]
          ... Key = Value
          ...
          ... [Section2]
          ... AnotherKey = Value
          ... """
          >>> typical = configparser.ConfigParser()
          >>> typical.read_string(config)
          >>> list(typical['Section1'].keys())
          ['key']
          >>> list(typical['Section2'].keys())
          ['anotherkey']
          >>> custom = configparser.RawConfigParser()
          >>> custom.optionxform = lambda option: option
          >>> custom.read_string(config)
          >>> list(custom['Section1'].keys())
          ['Key']
          >>> list(custom['Section2'].keys())
          ['AnotherKey']

          Nota: The optionxform function transforms option names to a
          canonical form.  This should be an idempotent function: if the
          name is already in canonical form, it should be returned
          unchanged.

 -- Attributo: ConfigParser.SECTCRE

     A compiled regular expression used to parse section headers.  The
     default matches ‘[section]’ to the name ‘"section"’.  Whitespace is
     considered part of the section name, thus ‘[ larch ]’ will be read
     as a section of name ‘" larch "’.  Override this attribute if
     that’s unsuitable.  For example:

          >>> import re
          >>> config = """
          ... [Section 1]
          ... option = value
          ...
          ... [  Section 2  ]
          ... another = val
          ... """
          >>> typical = configparser.ConfigParser()
          >>> typical.read_string(config)
          >>> typical.sections()
          ['Section 1', '  Section 2  ']
          >>> custom = configparser.ConfigParser()
          >>> custom.SECTCRE = re.compile(r"\[ *(?P<header>[^]]+?) *\]")
          >>> custom.read_string(config)
          >>> custom.sections()
          ['Section 1', 'Section 2']

          Nota: While ConfigParser objects also use an ‘OPTCRE’
          attribute for recognizing option lines, it’s not recommended
          to override it because that would interfere with constructor
          options 'allow_no_value' and 'delimiters'.


File: python.info,  Node: Legacy API Examples,  Next: ConfigParser Objects,  Prev: Customizing Parser Behaviour,  Up: configparser — Configuration file parser

5.14.2.9 Legacy API Examples
............................

Mainly because of backwards compatibility concerns, *note configparser:
26. provides also a legacy API with explicit ‘get’/‘set’ methods.  While
there are valid use cases for the methods outlined below, mapping
protocol access is preferred for new projects.  The legacy API is at
times more advanced, low-level and downright counterintuitive.

An example of writing to a configuration file:

     import configparser

     config = configparser.RawConfigParser()

     # Please note that using RawConfigParser's set functions, you can assign
     # non-string values to keys internally, but will receive an error when
     # attempting to write to a file or when you get it in non-raw mode. Setting
     # values using the mapping protocol or ConfigParser's set() does not allow
     # such assignments to take place.
     config.add_section('Section1')
     config.set('Section1', 'an_int', '15')
     config.set('Section1', 'a_bool', 'true')
     config.set('Section1', 'a_float', '3.1415')
     config.set('Section1', 'baz', 'fun')
     config.set('Section1', 'bar', 'Python')
     config.set('Section1', 'foo', '%(bar)s is %(baz)s!')

     # Writing our configuration file to 'example.cfg'
     with open('example.cfg', 'w') as configfile:
         config.write(configfile)

An example of reading the configuration file again:

     import configparser

     config = configparser.RawConfigParser()
     config.read('example.cfg')

     # getfloat() raises an exception if the value is not a float
     # getint() and getboolean() also do this for their respective types
     a_float = config.getfloat('Section1', 'a_float')
     an_int = config.getint('Section1', 'an_int')
     print(a_float + an_int)

     # Notice that the next output does not interpolate '%(bar)s' or '%(baz)s'.
     # This is because we are using a RawConfigParser().
     if config.getboolean('Section1', 'a_bool'):
         print(config.get('Section1', 'foo'))

To get interpolation, use *note ConfigParser: 4df.:

     import configparser

     cfg = configparser.ConfigParser()
     cfg.read('example.cfg')

     # Set the optional *raw* argument of get() to True if you wish to disable
     # interpolation in a single get operation.
     print(cfg.get('Section1', 'foo', raw=False))  # -> "Python is fun!"
     print(cfg.get('Section1', 'foo', raw=True))   # -> "%(bar)s is %(baz)s!"

     # The optional *vars* argument is a dict with members that will take
     # precedence in interpolation.
     print(cfg.get('Section1', 'foo', vars={'bar': 'Documentation',
                                            'baz': 'evil'}))

     # The optional *fallback* argument can be used to provide a fallback value
     print(cfg.get('Section1', 'foo'))
           # -> "Python is fun!"

     print(cfg.get('Section1', 'foo', fallback='Monty is not.'))
           # -> "Python is fun!"

     print(cfg.get('Section1', 'monster', fallback='No such things as monsters.'))
           # -> "No such things as monsters."

     # A bare print(cfg.get('Section1', 'monster')) would raise NoOptionError
     # but we can also use:

     print(cfg.get('Section1', 'monster', fallback=None))
           # -> None

Default values are available in both types of ConfigParsers.  They are
used in interpolation if an option used is not defined elsewhere.

     import configparser

     # New instance with 'bar' and 'baz' defaulting to 'Life' and 'hard' each
     config = configparser.ConfigParser({'bar': 'Life', 'baz': 'hard'})
     config.read('example.cfg')

     print(config.get('Section1', 'foo'))     # -> "Python is fun!"
     config.remove_option('Section1', 'bar')
     config.remove_option('Section1', 'baz')
     print(config.get('Section1', 'foo'))     # -> "Life is hard!"


File: python.info,  Node: ConfigParser Objects,  Next: RawConfigParser Objects,  Prev: Legacy API Examples,  Up: configparser — Configuration file parser

5.14.2.10 ConfigParser Objects
..............................

 -- Classe: configparser.ConfigParser (defaults=None, dict_type=dict,
          allow_no_value=False, *, delimiters=('=', ':'),
          comment_prefixes=('#', ';'), inline_comment_prefixes=None,
          strict=True, empty_lines_in_values=True,
          default_section=configparser.DEFAULTSECT,
          interpolation=BasicInterpolation(), converters={},
          allow_unnamed_section=False)

     The main configuration parser.  When 'defaults' is given, it is
     initialized into the dictionary of intrinsic defaults.  When
     'dict_type' is given, it will be used to create the dictionary
     objects for the list of sections, for the options within a section,
     and for the default values.

     When 'delimiters' is given, it is used as the set of substrings
     that divide keys from values.  When 'comment_prefixes' is given, it
     will be used as the set of substrings that prefix comments in
     otherwise empty lines.  Comments can be indented.  When
     'inline_comment_prefixes' is given, it will be used as the set of
     substrings that prefix comments in non-empty lines.

     When 'strict' is ‘True’ (the default), the parser won’t allow for
     any section or option duplicates while reading from a single source
     (file, string or dictionary), raising *note DuplicateSectionError:
     1476. or *note DuplicateOptionError: 1477.  When
     'empty_lines_in_values' is ‘False’ (default: ‘True’), each empty
     line marks the end of an option.  Otherwise, internal empty lines
     of a multiline option are kept as part of the value.  When
     'allow_no_value' is ‘True’ (default: ‘False’), options without
     values are accepted; the value held for these is ‘None’ and they
     are serialized without the trailing delimiter.

     When 'default_section' is given, it specifies the name for the
     special section holding default values for other sections and
     interpolation purposes (normally named ‘"DEFAULT"’).  This value
     can be retrieved and changed at runtime using the ‘default_section’
     instance attribute.  This won’t re-evaluate an already parsed
     config file, but will be used when writing parsed settings to a new
     config file.

     Interpolation behaviour may be customized by providing a custom
     handler through the 'interpolation' argument.  ‘None’ can be used
     to turn off interpolation completely, ‘ExtendedInterpolation()’
     provides a more advanced variant inspired by ‘zc.buildout’.  More
     on the subject in the *note dedicated documentation section: 2f60.

     All option names used in interpolation will be passed through the
     *note optionxform(): 2f67. method just like any other option name
     reference.  For example, using the default implementation of *note
     optionxform(): 2f67. (which converts option names to lower case),
     the values ‘foo %(bar)s’ and ‘foo %(BAR)s’ are equivalent.

     When 'converters' is given, it should be a dictionary where each
     key represents the name of a type converter and each value is a
     callable implementing the conversion from string to the desired
     datatype.  Every converter gets its own corresponding ‘get*()’
     method on the parser object and section proxies.

     When 'allow_unnamed_section' is ‘True’ (default: ‘False’), the
     first section name can be omitted.  See the *note "Unnamed
     Sections" section: 2f5f.

     It is possible to read several configurations into a single *note
     ConfigParser: 4df, where the most recently added configuration has
     the highest priority.  Any conflicting keys are taken from the more
     recent configuration while the previously existing keys are
     retained.  The example below reads in an ‘override.ini’ file, which
     will override any conflicting keys from the ‘example.ini’ file.

          [DEFAULT]
          ServerAliveInterval = -1

          >>> config_override = configparser.ConfigParser()
          >>> config_override['DEFAULT'] = {'ServerAliveInterval': '-1'}
          >>> with open('override.ini', 'w') as configfile:
          ...     config_override.write(configfile)
          ...
          >>> config_override = configparser.ConfigParser()
          >>> config_override.read(['example.ini', 'override.ini'])
          ['example.ini', 'override.ini']
          >>> print(config_override.get('DEFAULT', 'ServerAliveInterval'))
          -1

     Cambiato nella versione 3.1: The default 'dict_type' is *note
     collections.OrderedDict: 7f4.

     Cambiato nella versione 3.2: 'allow_no_value', 'delimiters',
     'comment_prefixes', 'strict', 'empty_lines_in_values',
     'default_section' and 'interpolation' were added.

     Cambiato nella versione 3.5: The 'converters' argument was added.

     Cambiato nella versione 3.7: The 'defaults' argument is read with
     *note read_dict(): 2f61, providing consistent behavior across the
     parser: non-string keys and values are implicitly converted to
     strings.

     Cambiato nella versione 3.8: The default 'dict_type' is *note dict:
     183, since it now preserves insertion order.

     Cambiato nella versione 3.13: Raise a *note
     MultilineContinuationError: 2f68. when 'allow_no_value' is ‘True’,
     and a key without a value is continued with an indented line.

     Cambiato nella versione 3.13: The 'allow_unnamed_section' argument
     was added.

      -- Metodo: defaults ()

          Return a dictionary containing the instance-wide defaults.

      -- Metodo: sections ()

          Return a list of the sections available; the 'default section'
          is not included in the list.

      -- Metodo: add_section (section)

          Add a section named 'section' to the instance.  If a section
          by the given name already exists, *note DuplicateSectionError:
          1476. is raised.  If the 'default section' name is passed,
          *note ValueError: 2ec. is raised.  The name of the section
          must be a string; if not, *note TypeError: 198. is raised.

          Cambiato nella versione 3.2: Non-string section names raise
          *note TypeError: 198.

      -- Metodo: has_section (section)

          Indicates whether the named 'section' is present in the
          configuration.  The 'default section' is not acknowledged.

      -- Metodo: options (section)

          Return a list of options available in the specified 'section'.

      -- Metodo: has_option (section, option)

          If the given 'section' exists, and contains the given
          'option', return *note True: e09.; otherwise return *note
          False: d2d.  If the specified 'section' is *note None: 886. or
          an empty string, DEFAULT is assumed.

      -- Metodo: read (filenames, encoding=None)

          Attempt to read and parse an iterable of filenames, returning
          a list of filenames which were successfully parsed.

          If 'filenames' is a string, a *note bytes: 192. object or a
          *note path-like object: 5a1, it is treated as a single
          filename.  If a file named in 'filenames' cannot be opened,
          that file will be ignored.  This is designed so that you can
          specify an iterable of potential configuration file locations
          (for example, the current directory, the user’s home
          directory, and some system-wide directory), and all existing
          configuration files in the iterable will be read.

          If none of the named files exist, the *note ConfigParser: 4df.
          instance will contain an empty dataset.  An application which
          requires initial values to be loaded from a file should load
          the required file or files using *note read_file(): 72b.
          before calling *note read(): 166f. for any optional files:

               import configparser, os

               config = configparser.ConfigParser()
               config.read_file(open('defaults.cfg'))
               config.read(['site.cfg', os.path.expanduser('~/.myapp.cfg')],
                           encoding='cp1250')

          Cambiato nella versione 3.2: Added the 'encoding' parameter.
          Previously, all files were read using the default encoding for
          *note open(): 316.

          Cambiato nella versione 3.6.1: The 'filenames' parameter
          accepts a *note path-like object: 5a1.

          Cambiato nella versione 3.7: The 'filenames' parameter accepts
          a *note bytes: 192. object.

      -- Metodo: read_file (f, source=None)

          Read and parse configuration data from 'f' which must be an
          iterable yielding Unicode strings (for example files opened in
          text mode).

          Optional argument 'source' specifies the name of the file
          being read.  If not given and 'f' has a ‘name’ attribute, that
          is used for 'source'; the default is ‘'<???>'’.

          Added in version 3.2: Replaces ‘readfp()’.

      -- Metodo: read_string (string, source='<string>')

          Parse configuration data from a string.

          Optional argument 'source' specifies a context-specific name
          of the string passed.  If not given, ‘'<string>'’ is used.
          This should commonly be a filesystem path or a URL.

          Added in version 3.2.

      -- Metodo: read_dict (dictionary, source='<dict>')

          Load configuration from any object that provides a dict-like
          ‘items()’ method.  Keys are section names, values are
          dictionaries with keys and values that should be present in
          the section.  If the used dictionary type preserves order,
          sections and their keys will be added in order.  Values are
          automatically converted to strings.

          Optional argument 'source' specifies a context-specific name
          of the dictionary passed.  If not given, ‘<dict>’ is used.

          This method can be used to copy state between parsers.

          Added in version 3.2.

      -- Metodo: get (section, option, *, raw=False, vars=None[,
               fallback])

          Get an 'option' value for the named 'section'.  If 'vars' is
          provided, it must be a dictionary.  The 'option' is looked up
          in 'vars' (if provided), 'section', and in 'DEFAULTSECT' in
          that order.  If the key is not found and 'fallback' is
          provided, it is used as a fallback value.  ‘None’ can be
          provided as a 'fallback' value.

          All the ‘'%'’ interpolations are expanded in the return
          values, unless the 'raw' argument is true.  Values for
          interpolation keys are looked up in the same manner as the
          option.

          Cambiato nella versione 3.2: Arguments 'raw', 'vars' and
          'fallback' are keyword only to protect users from trying to
          use the third argument as the 'fallback' fallback (especially
          when using the mapping protocol).

      -- Metodo: getint (section, option, *, raw=False, vars=None[,
               fallback])

          A convenience method which coerces the 'option' in the
          specified 'section' to an integer.  See *note get(): 1473. for
          explanation of 'raw', 'vars' and 'fallback'.

      -- Metodo: getfloat (section, option, *, raw=False, vars=None[,
               fallback])

          A convenience method which coerces the 'option' in the
          specified 'section' to a floating-point number.  See *note
          get(): 1473. for explanation of 'raw', 'vars' and 'fallback'.

      -- Metodo: getboolean (section, option, *, raw=False, vars=None[,
               fallback])

          A convenience method which coerces the 'option' in the
          specified 'section' to a Boolean value.  Note that the
          accepted values for the option are ‘'1'’, ‘'yes'’, ‘'true'’,
          and ‘'on'’, which cause this method to return ‘True’, and
          ‘'0'’, ‘'no'’, ‘'false'’, and ‘'off'’, which cause it to
          return ‘False’.  These string values are checked in a
          case-insensitive manner.  Any other value will cause it to
          raise *note ValueError: 2ec.  See *note get(): 1473. for
          explanation of 'raw', 'vars' and 'fallback'.

      -- Metodo: items (raw=False, vars=None)

      -- Metodo: items (section, raw=False, vars=None)

          When 'section' is not given, return a list of 'section_name',
          'section_proxy' pairs, including DEFAULTSECT.

          Otherwise, return a list of 'name', 'value' pairs for the
          options in the given 'section'.  Optional arguments have the
          same meaning as for the *note get(): 1473. method.

          Cambiato nella versione 3.8: Items present in 'vars' no longer
          appear in the result.  The previous behaviour mixed actual
          parser options with variables provided for interpolation.

      -- Metodo: set (section, option, value)

          If the given section exists, set the given option to the
          specified value; otherwise raise *note NoSectionError: 2f6f.
          'option' and 'value' must be strings; if not, *note TypeError:
          198. is raised.

      -- Metodo: write (fileobject, space_around_delimiters=True)

          Write a representation of the configuration to the specified
          *note file object: 13cb, which must be opened in text mode
          (accepting strings).  This representation can be parsed by a
          future *note read(): 166f. call.  If 'space_around_delimiters'
          is true, delimiters between keys and values are surrounded by
          spaces.

          Cambiato nella versione 3.14: Raises InvalidWriteError if this
          would write a representation which cannot be accurately parsed
          by a future *note read(): 166f. call from this parser.

          Nota: Comments in the original configuration file are not
          preserved when writing the configuration back.  What is
          considered a comment, depends on the given values for
          'comment_prefix' and 'inline_comment_prefix'.

      -- Metodo: remove_option (section, option)

          Remove the specified 'option' from the specified 'section'.
          If the section does not exist, raise *note NoSectionError:
          2f6f.  If the option existed to be removed, return *note True:
          e09.; otherwise return *note False: d2d.

      -- Metodo: remove_section (section)

          Remove the specified 'section' from the configuration.  If the
          section in fact existed, return ‘True’.  Otherwise return
          ‘False’.

      -- Metodo: optionxform (option)

          Transforms the option name 'option' as found in an input file
          or as passed in by client code to the form that should be used
          in the internal structures.  The default implementation
          returns a lower-case version of 'option'; subclasses may
          override this or client code can set an attribute of this name
          on instances to affect this behavior.

          You don’t need to subclass the parser to use this method, you
          can also set it on an instance, to a function that takes a
          string argument and returns a string.  Setting it to ‘str’,
          for example, would make option names case sensitive:

               cfgparser = ConfigParser()
               cfgparser.optionxform = str

          Note that when reading configuration files, whitespace around
          the option names is stripped before *note optionxform(): 2f67.
          is called.

 -- Dati: configparser.UNNAMED_SECTION

     A special object representing a section name used to reference the
     unnamed section (see *note Unnamed Sections: 2f5f.).

 -- Dati: configparser.MAX_INTERPOLATION_DEPTH

     The maximum depth for recursive interpolation for *note get():
     1473. when the 'raw' parameter is false.  This is relevant only
     when the default 'interpolation' is used.


File: python.info,  Node: RawConfigParser Objects,  Next: Exceptions<8>,  Prev: ConfigParser Objects,  Up: configparser — Configuration file parser

5.14.2.11 RawConfigParser Objects
.................................

 -- Classe: configparser.RawConfigParser (defaults=None, dict_type=dict,
          allow_no_value=False, *, delimiters=('=', ':'),
          comment_prefixes=('#', ';'), inline_comment_prefixes=None,
          strict=True, empty_lines_in_values=True,
          default_section=configparser.DEFAULTSECT,
          interpolation=BasicInterpolation(), converters={},
          allow_unnamed_section=False)

     Legacy variant of the *note ConfigParser: 4df.  It has
     interpolation disabled by default and allows for non-string section
     names, option names, and values via its unsafe ‘add_section’ and
     ‘set’ methods, as well as the legacy ‘defaults=’ keyword argument
     handling.

     Cambiato nella versione 3.2: 'allow_no_value', 'delimiters',
     'comment_prefixes', 'strict', 'empty_lines_in_values',
     'default_section' and 'interpolation' were added.

     Cambiato nella versione 3.5: The 'converters' argument was added.

     Cambiato nella versione 3.8: The default 'dict_type' is *note dict:
     183, since it now preserves insertion order.

     Cambiato nella versione 3.13: The 'allow_unnamed_section' argument
     was added.

          Nota: Consider using *note ConfigParser: 4df. instead which
          checks types of the values to be stored internally.  If you
          don’t want interpolation, you can use
          ‘ConfigParser(interpolation=None)’.

      -- Metodo: add_section (section)

          Add a section named 'section' or *note UNNAMED_SECTION: 1772.
          to the instance.

          If the given section already exists, *note
          DuplicateSectionError: 1476. is raised.  If the 'default
          section' name is passed, *note ValueError: 2ec. is raised.  If
          *note UNNAMED_SECTION: 1772. is passed and support is
          disabled, *note UnnamedSectionDisabledError: 2f76. is raised.

          Type of 'section' is not checked which lets users create
          non-string named sections.  This behaviour is unsupported and
          may cause internal errors.

     Cambiato nella versione 3.14: Added support for *note
     UNNAMED_SECTION: 1772.

      -- Metodo: set (section, option, value)

          If the given section exists, set the given option to the
          specified value; otherwise raise *note NoSectionError: 2f6f.
          While it is possible to use *note RawConfigParser: 1166. (or
          *note ConfigParser: 4df. with 'raw' parameters set to true)
          for 'internal' storage of non-string values, full
          functionality (including interpolation and output to files)
          can only be achieved using string values.

          This method lets users assign non-string values to keys
          internally.  This behaviour is unsupported and will cause
          errors when attempting to write to a file or get it in non-raw
          mode.  'Use the mapping protocol API' which does not allow
          such assignments to take place.


File: python.info,  Node: Exceptions<8>,  Prev: RawConfigParser Objects,  Up: configparser — Configuration file parser

5.14.2.12 Exceptions
....................

 -- Eccezione: configparser.Error

     Base class for all other *note configparser: 26. exceptions.

 -- Eccezione: configparser.NoSectionError

     Exception raised when a specified section is not found.

 -- Eccezione: configparser.DuplicateSectionError

     Exception raised if *note add_section(): 1475. is called with the
     name of a section that is already present or in strict parsers when
     a section if found more than once in a single input file, string or
     dictionary.

     Cambiato nella versione 3.2: Added the optional 'source' and
     'lineno' attributes and parameters to ‘__init__()’.

 -- Eccezione: configparser.DuplicateOptionError

     Exception raised by strict parsers if a single option appears twice
     during reading from a single file, string or dictionary.  This
     catches misspellings and case sensitivity-related errors, e.g.  a
     dictionary may have two keys representing the same case-insensitive
     configuration key.

 -- Eccezione: configparser.NoOptionError

     Exception raised when a specified option is not found in the
     specified section.

 -- Eccezione: configparser.InterpolationError

     Base class for exceptions raised when problems occur performing
     string interpolation.

 -- Eccezione: configparser.InterpolationDepthError

     Exception raised when string interpolation cannot be completed
     because the number of iterations exceeds *note
     MAX_INTERPOLATION_DEPTH: 2f72.  Subclass of *note
     InterpolationError: 2f7b.

 -- Eccezione: configparser.InterpolationMissingOptionError

     Exception raised when an option referenced from a value does not
     exist.  Subclass of *note InterpolationError: 2f7b.

 -- Eccezione: configparser.InterpolationSyntaxError

     Exception raised when the source text into which substitutions are
     made does not conform to the required syntax.  Subclass of *note
     InterpolationError: 2f7b.

 -- Eccezione: configparser.MissingSectionHeaderError

     Exception raised when attempting to parse a file which has no
     section headers.

 -- Eccezione: configparser.ParsingError

     Exception raised when errors occur attempting to parse a file.

     Cambiato nella versione 3.12: The ‘filename’ attribute and
     ‘__init__()’ constructor argument were removed.  They have been
     available using the name ‘source’ since 3.2.

 -- Eccezione: configparser.MultilineContinuationError

     Exception raised when a key without a corresponding value is
     continued with an indented line.

     Added in version 3.13.

 -- Eccezione: configparser.UnnamedSectionDisabledError

     Exception raised when attempting to use the *note UNNAMED_SECTION:
     1772. without enabling it.

          Added in version 3.14.

 -- Eccezione: configparser.InvalidWriteError

     Exception raised when an attempted *note ConfigParser.write(): 1de.
     would not be parsed accurately with a future *note
     ConfigParser.read(): 166f. call.

     Ex: Writing a key beginning with the *note ConfigParser.SECTCRE:
     2f5d. pattern would parse as a section header when read.
     Attempting to write this will raise this exception.

     Added in version 3.14.


File: python.info,  Node: tomllib — Parse TOML files,  Next: netrc — netrc file processing,  Prev: configparser — Configuration file parser,  Up: File Formats

5.14.3 ‘tomllib’ — Parse TOML files
-----------------------------------

Added in version 3.11.

'Source code:' Lib/tomllib(1)

__________________________________________________________________

This module provides an interface for parsing TOML 1.0.0 (Tom’s Obvious
Minimal Language, https://toml.io(2)).  This module does not support
writing TOML.

Vedi anche
..........

The Tomli-W package(3) is a TOML writer that can be used in conjunction
with this module, providing a write API familiar to users of the
standard library *note marshal: 91. and *note pickle: ab. modules.

Vedi anche
..........

The TOML Kit package(4) is a style-preserving TOML library with both
read and write capability.  It is a recommended replacement for this
module for editing already existing TOML files.

This module defines the following functions:

 -- Funzione: tomllib.load (fp, /, *, parse_float=float)

     Read a TOML file.  The first argument should be a readable and
     binary file object.  Return a *note dict: 183.  Convert TOML types
     to Python using this *note conversion table: 2f84.

     'parse_float' will be called with the string of every TOML float to
     be decoded.  By default, this is equivalent to ‘float(num_str)’.
     This can be used to use another datatype or parser for TOML floats
     (e.g.  *note decimal.Decimal: 1fe.).  The callable must not return
     a *note dict: 183. or a *note list: 24d, else a *note ValueError:
     2ec. is raised.

     A *note TOMLDecodeError: 18f5. will be raised on an invalid TOML
     document.

 -- Funzione: tomllib.loads (s, /, *, parse_float=float)

     Load TOML from a *note str: 169. object.  Return a *note dict: 183.
     Convert TOML types to Python using this *note conversion table:
     2f84.  The 'parse_float' argument has the same meaning as in *note
     load(): 2f83.

     A *note TOMLDecodeError: 18f5. will be raised on an invalid TOML
     document.

The following exceptions are available:

 -- Eccezione: tomllib.TOMLDecodeError (msg, doc, pos)

     Subclass of *note ValueError: 2ec. with the following additional
     attributes:

      -- Attributo: msg

          The unformatted error message.

      -- Attributo: doc

          The TOML document being parsed.

      -- Attributo: pos

          The index of 'doc' where parsing failed.

      -- Attributo: lineno

          The line corresponding to 'pos'.

      -- Attributo: colno

          The column corresponding to 'pos'.

     Cambiato nella versione 3.14: Added the 'msg', 'doc' and 'pos'
     parameters.  Added the *note msg: 2f85, *note doc: 2f86, *note pos:
     2f87, *note lineno: 2f88. and *note colno: 2f89. attributes.

     Deprecato dalla versione 3.14: Passing free-form positional
     arguments is deprecated.

* Menu:

* Examples: Examples<12>.
* Conversion Table::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/tomllib

   (2) https://toml.io/en/

   (3) https://pypi.org/project/tomli-w/

   (4) https://pypi.org/project/tomlkit/


File: python.info,  Node: Examples<12>,  Next: Conversion Table,  Up: tomllib — Parse TOML files

5.14.3.1 Examples
.................

Parsing a TOML file:

     import tomllib

     with open("pyproject.toml", "rb") as f:
         data = tomllib.load(f)

Parsing a TOML string:

     import tomllib

     toml_str = """
     python-version = "3.11.0"
     python-implementation = "CPython"
     """

     data = tomllib.loads(toml_str)


File: python.info,  Node: Conversion Table,  Prev: Examples<12>,  Up: tomllib — Parse TOML files

5.14.3.2 Conversion Table
.........................

TOML                   Python
                       
------------------------------------------------------------------------------------------------------------------
                       
TOML document          dict
                       
                       
string                 str
                       
                       
integer                int
                       
                       
float                  float (configurable with 'parse_float')
                       
                       
boolean                bool
                       
                       
offset date-time       datetime.datetime (‘tzinfo’ attribute set to an instance of ‘datetime.timezone’)
                       
                       
local date-time        datetime.datetime (‘tzinfo’ attribute set to ‘None’)
                       
                       
local date             datetime.date
                       
                       
local time             datetime.time
                       
                       
array                  list
                       
                       
table                  dict
                       
                       
inline table           dict
                       
                       
array of tables        list of dicts
                       


File: python.info,  Node: netrc — netrc file processing,  Next: plistlib — Generate and parse Apple plist files,  Prev: tomllib — Parse TOML files,  Up: File Formats

5.14.4 ‘netrc’ — netrc file processing
--------------------------------------

'Source code:' Lib/netrc.py(1)

__________________________________________________________________

The *note netrc: 1c61. class parses and encapsulates the netrc file
format used by the Unix ‘ftp’ program and other FTP clients.

 -- Classe: netrc.netrc ([file])

     A *note netrc: 1c61. instance or subclass instance encapsulates
     data from a netrc file.  The initialization argument, if present,
     specifies the file to parse.  If no argument is given, the file
     ‘.netrc’ in the user’s home directory – as determined by *note
     os.path.expanduser(): c0b. – will be read.  Otherwise, a *note
     FileNotFoundError: 264. exception will be raised.  Parse errors
     will raise *note NetrcParseError: 2f8f. with diagnostic information
     including the file name, line number, and terminating token.

     If no argument is specified on a POSIX system, the presence of
     passwords in the ‘.netrc’ file will raise a *note NetrcParseError:
     2f8f. if the file ownership or permissions are insecure (owned by a
     user other than the user running the process, or accessible for
     read or write by any other user).  This implements security
     behavior equivalent to that of ftp and other programs that use
     ‘.netrc’.  Such security checks are not available on platforms that
     do not support *note os.getuid(): 17ff.

     Cambiato nella versione 3.4: Added the POSIX permission check.

     Cambiato nella versione 3.7: *note os.path.expanduser(): c0b. is
     used to find the location of the ‘.netrc’ file when 'file' is not
     passed as argument.

     Cambiato nella versione 3.10: *note netrc: 9f. try UTF-8 encoding
     before using locale specific encoding.  The entry in the netrc file
     no longer needs to contain all tokens.  The missing tokens” value
     default to an empty string.  All the tokens and their values now
     can contain arbitrary characters, like whitespace and non-ASCII
     characters.  If the login name is anonymous, it won’t trigger the
     security check.

 -- Eccezione: netrc.NetrcParseError

     Exception raised by the *note netrc: 1c61. class when syntactical
     errors are encountered in source text.  Instances of this exception
     provide three interesting attributes:

      -- Attributo: msg

          Textual explanation of the error.

      -- Attributo: filename

          The name of the source file.

      -- Attributo: lineno

          The line number on which the error was found.

* Menu:

* netrc Objects::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/netrc.py


File: python.info,  Node: netrc Objects,  Up: netrc — netrc file processing

5.14.4.1 netrc Objects
......................

A *note netrc: 1c61. instance has the following methods:

 -- Metodo: netrc.authenticators (host)

     Return a 3-tuple ‘(login, account, password)’ of authenticators for
     'host'.  If the netrc file did not contain an entry for the given
     host, return the tuple associated with the “default” entry.  If
     neither matching host nor default entry is available, return
     ‘None’.

 -- Metodo: netrc.__repr__ ()

     Dump the class data as a string in the format of a netrc file.
     (This discards comments and may reorder the entries.)

Instances of *note netrc: 1c61. have public instance variables:

 -- Attributo: netrc.hosts

     Dictionary mapping host names to ‘(login, account, password)’
     tuples.  The “default” entry, if any, is represented as a
     pseudo-host by that name.

 -- Attributo: netrc.macros

     Dictionary mapping macro names to string lists.


File: python.info,  Node: plistlib — Generate and parse Apple plist files,  Prev: netrc — netrc file processing,  Up: File Formats

5.14.5 ‘plistlib’ — Generate and parse Apple ‘.plist’ files
-----------------------------------------------------------

'Source code:' Lib/plistlib.py(1)

__________________________________________________________________

This module provides an interface for reading and writing the «property
list» files used by Apple, primarily on macOS and iOS. This module
supports both binary and XML plist files.

The property list (‘.plist’) file format is a simple serialization
supporting basic object types, like dictionaries, lists, numbers and
strings.  Usually the top level object is a dictionary.

To write out and to parse a plist file, use the *note dump(): b4c. and
*note load(): b4a. functions.

To work with plist data in bytes or string objects, use *note dumps():
b4d. and *note loads(): b4b.

Values can be strings, integers, floats, booleans, tuples, lists,
dictionaries (but only with string keys), *note bytes: 192, *note
bytearray: 344. or *note datetime.datetime: 4e3. objects.

Cambiato nella versione 3.4: New API, old API deprecated.  Support for
binary format plists added.

Cambiato nella versione 3.8: Support added for reading and writing *note
UID: c18. tokens in binary plists as used by NSKeyedArchiver and
NSKeyedUnarchiver.

Cambiato nella versione 3.9: Old API removed.

Vedi anche
..........

PList manual page(2)

     Apple’s documentation of the file format.

This module defines the following functions:

 -- Funzione: plistlib.load (fp, *, fmt=None, dict_type=dict,
          aware_datetime=False)

     Read a plist file.  'fp' should be a readable and binary file
     object.  Return the unpacked root object (which usually is a
     dictionary).

     The 'fmt' is the format of the file and the following values are
     valid:

        * *note None: 886.: Autodetect the file format

        * *note FMT_XML: 117b.: XML file format

        * *note FMT_BINARY: 117c.: Binary plist format

     The 'dict_type' is the type used for dictionaries that are read
     from the plist file.

     When 'aware_datetime' is true, fields with type ‘datetime.datetime’
     will be created as *note aware object: 287d, with ‘tzinfo’ as *note
     datetime.UTC: 714.

     XML data for the *note FMT_XML: 117b. format is parsed using the
     Expat parser from *note xml.parsers.expat: 12c. – see its
     documentation for possible exceptions on ill-formed XML. Unknown
     elements will simply be ignored by the plist parser.

     The parser raises *note InvalidFileException: 1ce2. when the file
     cannot be parsed.

     Added in version 3.4.

     Cambiato nella versione 3.13: The keyword-only parameter
     'aware_datetime' has been added.

 -- Funzione: plistlib.loads (data, *, fmt=None, dict_type=dict,
          aware_datetime=False)

     Load a plist from a bytes or string object.  See *note load(): b4a.
     for an explanation of the keyword arguments.

     Added in version 3.4.

     Cambiato nella versione 3.13: 'data' can be a string when 'fmt'
     equals *note FMT_XML: 117b.

 -- Funzione: plistlib.dump (value, fp, *, fmt=FMT_XML, sort_keys=True,
          skipkeys=False, aware_datetime=False)

     Write 'value' to a plist file.  'fp' should be a writable, binary
     file object.

     The 'fmt' argument specifies the format of the plist file and can
     be one of the following values:

        * *note FMT_XML: 117b.: XML formatted plist file

        * *note FMT_BINARY: 117c.: Binary formatted plist file

     When 'sort_keys' is true (the default) the keys for dictionaries
     will be written to the plist in sorted order, otherwise they will
     be written in the iteration order of the dictionary.

     When 'skipkeys' is false (the default) the function raises *note
     TypeError: 198. when a key of a dictionary is not a string,
     otherwise such keys are skipped.

     When 'aware_datetime' is true and any field with type
     ‘datetime.datetime’ is set as an *note aware object: 287d, it will
     convert to UTC timezone before writing it.

     A *note TypeError: 198. will be raised if the object is of an
     unsupported type or a container that contains objects of
     unsupported types.

     An *note OverflowError: a83. will be raised for integer values that
     cannot be represented in (binary) plist files.

     Added in version 3.4.

     Cambiato nella versione 3.13: The keyword-only parameter
     'aware_datetime' has been added.

 -- Funzione: plistlib.dumps (value, *, fmt=FMT_XML, sort_keys=True,
          skipkeys=False, aware_datetime=False)

     Return 'value' as a plist-formatted bytes object.  See the
     documentation for *note dump(): b4c. for an explanation of the
     keyword arguments of this function.

     Added in version 3.4.

The following classes are available:

 -- Classe: plistlib.UID (data)

     Wraps an *note int: 19b.  This is used when reading or writing
     NSKeyedArchiver encoded data, which contains UID (see PList
     manual).

      -- Attributo: data

          Int value of the UID. It must be in the range ‘0 <= data <
          2**64’.

     Added in version 3.8.

The following constants are available:

 -- Dati: plistlib.FMT_XML

     The XML format for plist files.

     Added in version 3.4.

 -- Dati: plistlib.FMT_BINARY

     The binary format for plist files

     Added in version 3.4.

The module defines the following exceptions:

 -- Eccezione: plistlib.InvalidFileException

     Raised when a file cannot be parsed.

     Added in version 3.4.

* Menu:

* Examples: Examples<13>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/plistlib.py

   (2) 
https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/PropertyLists/


File: python.info,  Node: Examples<13>,  Up: plistlib — Generate and parse Apple plist files

5.14.5.1 Examples
.................

Generating a plist:

     import datetime
     import plistlib

     pl = dict(
         aString = "Doodah",
         aList = ["A", "B", 12, 32.1, [1, 2, 3]],
         aFloat = 0.1,
         anInt = 728,
         aDict = dict(
             anotherString = "<hello & hi there!>",
             aThirdString = "M\xe4ssig, Ma\xdf",
             aTrueValue = True,
             aFalseValue = False,
         ),
         someData = b"<binary gunk>",
         someMoreData = b"<lots of binary gunk>" * 10,
         aDate = datetime.datetime.now()
     )
     print(plistlib.dumps(pl).decode())

Parsing a plist:

     import plistlib

     plist = b"""<plist version="1.0">
     <dict>
         <key>foo</key>
         <string>bar</string>
     </dict>
     </plist>"""
     pl = plistlib.loads(plist)
     print(pl["foo"])


File: python.info,  Node: Cryptographic Services,  Next: Generic Operating System Services,  Prev: File Formats,  Up: The Python Standard Library

5.15 Cryptographic Services
===========================

The modules described in this chapter implement various algorithms of a
cryptographic nature.  They are available at the discretion of the
installation.  Here’s an overview:

* Menu:

* hashlib — Secure hashes and message digests::
* hmac — Keyed-Hashing for Message Authentication::
* secrets — Generate secure random numbers for managing secrets::


File: python.info,  Node: hashlib — Secure hashes and message digests,  Next: hmac — Keyed-Hashing for Message Authentication,  Up: Cryptographic Services

5.15.1 ‘hashlib’ — Secure hashes and message digests
----------------------------------------------------

'Source code:' Lib/hashlib.py(1)

__________________________________________________________________

This module implements a common interface to many different hash
algorithms.  Included are the FIPS secure hash algorithms SHA224,
SHA256, SHA384, SHA512, (defined in the FIPS 180-4 standard(2)), the
SHA-3 series (defined in the FIPS 202 standard(3)) as well as the legacy
algorithms SHA1 (formerly part of FIPS(4)) and the MD5 algorithm
(defined in internet RFC 1321(5)).

     Nota: If you want the adler32 or crc32 hash functions, they are
     available in the *note zlib: 139. module.

* Menu:

* Hash algorithms::
* Usage::
* Constructors::
* Attributes::
* Hash Objects::
* SHAKE variable length digests::
* File hashing::
* Key derivation::
* BLAKE2::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/hashlib.py

   (2) https://csrc.nist.gov/pubs/fips/180-4/upd1/final

   (3) https://csrc.nist.gov/pubs/fips/202/final

   (4) https://csrc.nist.gov/news/2023/decision-to-revise-fips-180-4

   (5) https://datatracker.ietf.org/doc/html/rfc1321.html


File: python.info,  Node: Hash algorithms,  Next: Usage,  Up: hashlib — Secure hashes and message digests

5.15.1.1 Hash algorithms
........................

There is one constructor method named for each type of 'hash'.  All
return a hash object with the same simple interface.  For example: use
*note sha256(): 1896. to create a SHA-256 hash object.  You can now feed
this object with *note bytes-like objects: 193. (normally *note bytes:
192.) using the *note update: 2fa6. method.  At any point you can ask it
for the 'digest' of the concatenation of the data fed to it so far using
the *note digest(): 2fa7. or *note hexdigest(): 2fa8. methods.

To allow multithreading, the Python *note GIL: 164. is released while
computing a hash supplied more than 2047 bytes of data at once in its
constructor or *note .update: 2fa6. method.

Constructors for hash algorithms that are always present in this module
are *note sha1(): 2fa9, *note sha224(): 2faa, *note sha256(): 1896,
*note sha384(): 2fab, *note sha512(): 2fac, *note sha3_224(): ea2, *note
sha3_256(): ea3, *note sha3_384(): ea4, *note sha3_512(): ea5, *note
shake_128(): ea6, *note shake_256(): ea7, *note blake2b(): 853, and
*note blake2s(): 854.  *note md5(): 180b. is normally available as well,
though it may be missing or blocked if you are using a rare «FIPS
compliant» build of Python.  These correspond to *note
algorithms_guaranteed: 157b.

Additional algorithms may also be available if your Python
distribution’s *note hashlib: 6c. was linked against a build of OpenSSL
that provides others.  Others 'are not guaranteed available' on all
installations and will only be accessible by name via *note new(): 1d16.
See *note algorithms_available: 157c.

     Avvertimento: Some algorithms have known hash collision weaknesses
     (including MD5 and SHA1).  Refer to Attacks on cryptographic hash
     algorithms(1) and the *note hashlib-seealso: 2fad. section at the
     end of this document.

Added in version 3.6: SHA3 (Keccak) and SHAKE constructors *note
sha3_224(): ea2, *note sha3_256(): ea3, *note sha3_384(): ea4, *note
sha3_512(): ea5, *note shake_128(): ea6, *note shake_256(): ea7. were
added.  *note blake2b(): 853. and *note blake2s(): 854. were added.

Cambiato nella versione 3.9: All hashlib constructors take a
keyword-only argument 'usedforsecurity' with default value ‘True’.  A
false value allows the use of insecure and blocked hashing algorithms in
restricted environments.  ‘False’ indicates that the hashing algorithm
is not used in a security context, e.g.  as a non-cryptographic one-way
compression function.

Cambiato nella versione 3.9: Hashlib now uses SHA3 and SHAKE from
OpenSSL if it provides it.

Cambiato nella versione 3.12: For any of the MD5, SHA1, SHA2, or SHA3
algorithms that the linked OpenSSL does not provide we fall back to a
verified implementation from the HACL* project(2).

   ---------- Footnotes ----------

   (1) 
https://en.wikipedia.org/wiki/Cryptographic_hash_function#Attacks_on_cryptographic_hash_algorithms

   (2) https://github.com/hacl-star/hacl-star


File: python.info,  Node: Usage,  Next: Constructors,  Prev: Hash algorithms,  Up: hashlib — Secure hashes and message digests

5.15.1.2 Usage
..............

To obtain the digest of the byte string ‘b"Nobody inspects the spammish
repetition"’:

     >>> import hashlib
     >>> m = hashlib.sha256()
     >>> m.update(b"Nobody inspects")
     >>> m.update(b" the spammish repetition")
     >>> m.digest()
     b'\x03\x1e\xdd}Ae\x15\x93\xc5\xfe\\\x00o\xa5u+7\xfd\xdf\xf7\xbcN\x84:\xa6\xaf\x0c\x95\x0fK\x94\x06'
     >>> m.hexdigest()
     '031edd7d41651593c5fe5c006fa5752b37fddff7bc4e843aa6af0c950f4b9406'

More condensed:

     >>> hashlib.sha256(b"Nobody inspects the spammish repetition").hexdigest()
     '031edd7d41651593c5fe5c006fa5752b37fddff7bc4e843aa6af0c950f4b9406'


File: python.info,  Node: Constructors,  Next: Attributes,  Prev: Usage,  Up: hashlib — Secure hashes and message digests

5.15.1.3 Constructors
.....................

 -- Funzione: hashlib.new (name[, data], *, usedforsecurity=True)

     Is a generic constructor that takes the string 'name' of the
     desired algorithm as its first parameter.  It also exists to allow
     access to the above listed hashes as well as any other algorithms
     that your OpenSSL library may offer.

Using *note new(): 1d16. with an algorithm name:

     >>> h = hashlib.new('sha256')
     >>> h.update(b"Nobody inspects the spammish repetition")
     >>> h.hexdigest()
     '031edd7d41651593c5fe5c006fa5752b37fddff7bc4e843aa6af0c950f4b9406'

 -- Funzione: hashlib.md5 ([data], *, usedforsecurity=True)

 -- Funzione: hashlib.sha1 ([data], *, usedforsecurity=True)

 -- Funzione: hashlib.sha224 ([data], *, usedforsecurity=True)

 -- Funzione: hashlib.sha256 ([data], *, usedforsecurity=True)

 -- Funzione: hashlib.sha384 ([data], *, usedforsecurity=True)

 -- Funzione: hashlib.sha512 ([data], *, usedforsecurity=True)

 -- Funzione: hashlib.sha3_224 ([data], *, usedforsecurity=True)

 -- Funzione: hashlib.sha3_256 ([data], *, usedforsecurity=True)

 -- Funzione: hashlib.sha3_384 ([data], *, usedforsecurity=True)

 -- Funzione: hashlib.sha3_512 ([data], *, usedforsecurity=True)

Named constructors such as these are faster than passing an algorithm
name to *note new(): 1d16.


File: python.info,  Node: Attributes,  Next: Hash Objects,  Prev: Constructors,  Up: hashlib — Secure hashes and message digests

5.15.1.4 Attributes
...................

Hashlib provides the following constant module attributes:

 -- Dati: hashlib.algorithms_guaranteed

     A set containing the names of the hash algorithms guaranteed to be
     supported by this module on all platforms.  Note that “md5” is in
     this list despite some upstream vendors offering an odd «FIPS
     compliant» Python build that excludes it.

     Added in version 3.2.

 -- Dati: hashlib.algorithms_available

     A set containing the names of the hash algorithms that are
     available in the running Python interpreter.  These names will be
     recognized when passed to *note new(): 1d16.  *note
     algorithms_guaranteed: 157b. will always be a subset.  The same
     algorithm may appear multiple times in this set under different
     names (thanks to OpenSSL).

     Added in version 3.2.


File: python.info,  Node: Hash Objects,  Next: SHAKE variable length digests,  Prev: Attributes,  Up: hashlib — Secure hashes and message digests

5.15.1.5 Hash Objects
.....................

The following values are provided as constant attributes of the hash
objects returned by the constructors:

 -- Dati: hash.digest_size

     The size of the resulting hash in bytes.

 -- Dati: hash.block_size

     The internal block size of the hash algorithm in bytes.

A hash object has the following attributes:

 -- Attributo: hash.name

     The canonical name of this hash, always lowercase and always
     suitable as a parameter to *note new(): 1d16. to create another
     hash of this type.

     Cambiato nella versione 3.4: The name attribute has been present in
     CPython since its inception, but until Python 3.4 was not formally
     specified, so may not exist on some platforms.

A hash object has the following methods:

 -- Metodo: hash.update (data)

     Update the hash object with the *note bytes-like object: 193.
     Repeated calls are equivalent to a single call with the
     concatenation of all the arguments: ‘m.update(a); m.update(b)’ is
     equivalent to ‘m.update(a+b)’.

 -- Metodo: hash.digest ()

     Return the digest of the data passed to the *note update(): 2fa6.
     method so far.  This is a bytes object of size *note digest_size:
     2fb3. which may contain bytes in the whole range from 0 to 255.

 -- Metodo: hash.hexdigest ()

     Like *note digest(): 2fa7. except the digest is returned as a
     string object of double length, containing only hexadecimal digits.
     This may be used to exchange the value safely in email or other
     non-binary environments.

 -- Metodo: hash.copy ()

     Return a copy («clone») of the hash object.  This can be used to
     efficiently compute the digests of data sharing a common initial
     substring.


File: python.info,  Node: SHAKE variable length digests,  Next: File hashing,  Prev: Hash Objects,  Up: hashlib — Secure hashes and message digests

5.15.1.6 SHAKE variable length digests
......................................

 -- Funzione: hashlib.shake_128 ([data], *, usedforsecurity=True)

 -- Funzione: hashlib.shake_256 ([data], *, usedforsecurity=True)

The *note shake_128(): ea6. and *note shake_256(): ea7. algorithms
provide variable length digests with length_in_bits//2 up to 128 or 256
bits of security.  As such, their digest methods require a length.
Maximum length is not limited by the SHAKE algorithm.

 -- Metodo: shake.digest (length)

     Return the digest of the data passed to the *note update(): 2fa6.
     method so far.  This is a bytes object of size 'length' which may
     contain bytes in the whole range from 0 to 255.

 -- Metodo: shake.hexdigest (length)

     Like *note digest(): 1e02. except the digest is returned as a
     string object of double length, containing only hexadecimal digits.
     This may be used to exchange the value in email or other non-binary
     environments.

Example use:

     >>> h = hashlib.shake_256(b'Nobody inspects the spammish repetition')
     >>> h.hexdigest(20)
     '44709d6fcb83d92a76dcb0b668c98e1b1d3dafe7'


File: python.info,  Node: File hashing,  Next: Key derivation,  Prev: SHAKE variable length digests,  Up: hashlib — Secure hashes and message digests

5.15.1.7 File hashing
.....................

The hashlib module provides a helper function for efficient hashing of a
file or file-like object.

 -- Funzione: hashlib.file_digest (fileobj, digest, /)

     Return a digest object that has been updated with contents of file
     object.

     'fileobj' must be a file-like object opened for reading in binary
     mode.  It accepts file objects from builtin *note open(): 316,
     *note BytesIO: 10a6. instances, SocketIO objects from *note
     socket.socket.makefile(): 13a7, and similar.  'fileobj' must be
     opened in blocking mode, otherwise a *note BlockingIOError: 235.
     may be raised.

     The function may bypass Python’s I/O and use the file descriptor
     from *note fileno(): 1795. directly.  'fileobj' must be assumed to
     be in an unknown state after this function returns or raises.  It
     is up to the caller to close 'fileobj'.

     'digest' must either be a hash algorithm name as a 'str', a hash
     constructor, or a callable that returns a hash object.

     Example:

          >>> import io, hashlib, hmac
          >>> with open("library/hashlib.rst", "rb") as f:
          ...     digest = hashlib.file_digest(f, "sha256")
          ...
          >>> digest.hexdigest()
          '...'

          >>> buf = io.BytesIO(b"somedata")
          >>> mac1 = hmac.HMAC(b"key", digestmod=hashlib.sha512)
          >>> digest = hashlib.file_digest(buf, lambda: mac1)

          >>> digest is mac1
          True
          >>> mac2 = hmac.HMAC(b"key", b"somedata", digestmod=hashlib.sha512)
          >>> mac1.digest() == mac2.digest()
          True

     Added in version 3.11.

     Cambiato nella versione 3.14: Now raises a *note BlockingIOError:
     235. if the file is opened in non-blocking mode.  Previously,
     spurious null bytes were added to the digest.


File: python.info,  Node: Key derivation,  Next: BLAKE2,  Prev: File hashing,  Up: hashlib — Secure hashes and message digests

5.15.1.8 Key derivation
.......................

Key derivation and key stretching algorithms are designed for secure
password hashing.  Naive algorithms such as ‘sha1(password)’ are not
resistant against brute-force attacks.  A good password hashing function
must be tunable, slow, and include a salt(1).

 -- Funzione: hashlib.pbkdf2_hmac (hash_name, password, salt,
          iterations, dklen=None)

     The function provides PKCS#5 password-based key derivation function
     2.  It uses HMAC as pseudorandom function.

     The string 'hash_name' is the desired name of the hash digest
     algorithm for HMAC, e.g.  “sha1” or “sha256”.  'password' and
     'salt' are interpreted as buffers of bytes.  Applications and
     libraries should limit 'password' to a sensible length (e.g.
     1024).  'salt' should be about 16 or more bytes from a proper
     source, e.g.  *note os.urandom(): 747.

     The number of 'iterations' should be chosen based on the hash
     algorithm and computing power.  As of 2022, hundreds of thousands
     of iterations of SHA-256 are suggested.  For rationale as to why
     and how to choose what is best for your application, read 'Appendix
     A.2.2' of NIST-SP-800-132(2).  The answers on the stackexchange
     pbkdf2 iterations question(3) explain in detail.

     'dklen' is the length of the derived key in bytes.  If 'dklen' is
     ‘None’ then the digest size of the hash algorithm 'hash_name' is
     used, e.g.  64 for SHA-512.

          >>> from hashlib import pbkdf2_hmac
          >>> our_app_iters = 500_000  # Application specific, read above.
          >>> dk = pbkdf2_hmac('sha256', b'password', b'bad salt' * 2, our_app_iters)
          >>> dk.hex()
          '15530bba69924174860db778f2c6f8104d3aaf9d26241840c8c4a641c8d000a9'

     Function only available when Python is compiled with OpenSSL.

     Added in version 3.4.

     Cambiato nella versione 3.12: Function now only available when
     Python is built with OpenSSL. The slow pure Python implementation
     has been removed.

 -- Funzione: hashlib.scrypt (password, *, salt, n, r, p, maxmem=0,
          dklen=64)

     The function provides scrypt password-based key derivation function
     as defined in RFC 7914(4).

     'password' and 'salt' must be *note bytes-like objects: 193.
     Applications and libraries should limit 'password' to a sensible
     length (e.g.  1024).  'salt' should be about 16 or more bytes from
     a proper source, e.g.  *note os.urandom(): 747.

     'n' is the CPU/Memory cost factor, 'r' the block size, 'p'
     parallelization factor and 'maxmem' limits memory (OpenSSL 1.1.0
     defaults to 32 MiB). 'dklen' is the length of the derived key in
     bytes.

     Added in version 3.6.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Salt_%28cryptography%29

   (2) 
https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-132.pdf

   (3) 
https://security.stackexchange.com/questions/3959/recommended-of-iterations-when-using-pbkdf2-sha256/

   (4) https://datatracker.ietf.org/doc/html/rfc7914.html


File: python.info,  Node: BLAKE2,  Prev: Key derivation,  Up: hashlib — Secure hashes and message digests

5.15.1.9 BLAKE2
...............

BLAKE2(1) is a cryptographic hash function defined in RFC 7693(2) that
comes in two flavors:

   * 'BLAKE2b', optimized for 64-bit platforms and produces digests of
     any size between 1 and 64 bytes,

   * 'BLAKE2s', optimized for 8- to 32-bit platforms and produces
     digests of any size between 1 and 32 bytes.

BLAKE2 supports 'keyed mode' (a faster and simpler replacement for
HMAC(3)), 'salted hashing', 'personalization', and 'tree hashing'.

Hash objects from this module follow the API of standard library’s *note
hashlib: 6c. objects.

* Menu:

* Creating hash objects::
* Constants: Constants<5>.
* Examples: Examples<14>.
* Credits::

   ---------- Footnotes ----------

   (1) https://www.blake2.net

   (2) https://datatracker.ietf.org/doc/html/rfc7693.html

   (3) 
https://en.wikipedia.org/wiki/Hash-based_message_authentication_code


File: python.info,  Node: Creating hash objects,  Next: Constants<5>,  Up: BLAKE2

5.15.1.10 Creating hash objects
...............................

New hash objects are created by calling constructor functions:

 -- Funzione: hashlib.blake2b (data=b'', *, digest_size=64, key=b'',
          salt=b'', person=b'', fanout=1, depth=1, leaf_size=0,
          node_offset=0, node_depth=0, inner_size=0, last_node=False,
          usedforsecurity=True)

 -- Funzione: hashlib.blake2s (data=b'', *, digest_size=32, key=b'',
          salt=b'', person=b'', fanout=1, depth=1, leaf_size=0,
          node_offset=0, node_depth=0, inner_size=0, last_node=False,
          usedforsecurity=True)

These functions return the corresponding hash objects for calculating
BLAKE2b or BLAKE2s.  They optionally take these general parameters:

   * 'data': initial chunk of data to hash, which must be *note
     bytes-like object: 193.  It can be passed only as positional
     argument.

   * 'digest_size': size of output digest in bytes.

   * 'key': key for keyed hashing (up to 64 bytes for BLAKE2b, up to 32
     bytes for BLAKE2s).

   * 'salt': salt for randomized hashing (up to 16 bytes for BLAKE2b, up
     to 8 bytes for BLAKE2s).

   * 'person': personalization string (up to 16 bytes for BLAKE2b, up to
     8 bytes for BLAKE2s).

The following table shows limits for general parameters (in bytes):

Hash        digest_size     len(key)     len(salt)     len(person)
                                                       
-----------------------------------------------------------------------
                                                       
BLAKE2b     64              64           16            16
                                                       
                                                       
BLAKE2s     32              32           8             8
                                                       

     Nota: BLAKE2 specification defines constant lengths for salt and
     personalization parameters, however, for convenience, this
     implementation accepts byte strings of any size up to the specified
     length.  If the length of the parameter is less than specified, it
     is padded with zeros, thus, for example, ‘b'salt'’ and
     ‘b'salt\x00'’ is the same value.  (This is not the case for 'key'.)

These sizes are available as module *note constants: 2fbc. described
below.

Constructor functions also accept the following tree hashing parameters:

   * 'fanout': fanout (0 to 255, 0 if unlimited, 1 in sequential mode).

   * 'depth': maximal depth of tree (1 to 255, 255 if unlimited, 1 in
     sequential mode).

   * 'leaf_size': maximal byte length of leaf (0 to ‘2**32-1’, 0 if
     unlimited or in sequential mode).

   * 'node_offset': node offset (0 to ‘2**64-1’ for BLAKE2b, 0 to
     ‘2**48-1’ for BLAKE2s, 0 for the first, leftmost, leaf, or in
     sequential mode).

   * 'node_depth': node depth (0 to 255, 0 for leaves, or in sequential
     mode).

   * 'inner_size': inner digest size (0 to 64 for BLAKE2b, 0 to 32 for
     BLAKE2s, 0 in sequential mode).

   * 'last_node': boolean indicating whether the processed node is the
     last one (‘False’ for sequential mode).

[image src="python-figures/hashlib-blake2-tree.png" alt="Explanation of tree mode parameters."]


Figure
See section 2.10 in BLAKE2 specification(1) for comprehensive review of
tree hashing.

   ---------- Footnotes ----------

   (1) https://www.blake2.net/blake2_20130129.pdf


File: python.info,  Node: Constants<5>,  Next: Examples<14>,  Prev: Creating hash objects,  Up: BLAKE2

5.15.1.11 Constants
...................

 -- Dati: blake2b.SALT_SIZE

 -- Dati: blake2s.SALT_SIZE

Salt length (maximum length accepted by constructors).

 -- Dati: blake2b.PERSON_SIZE

 -- Dati: blake2s.PERSON_SIZE

Personalization string length (maximum length accepted by constructors).

 -- Dati: blake2b.MAX_KEY_SIZE

 -- Dati: blake2s.MAX_KEY_SIZE

Maximum key size.

 -- Dati: blake2b.MAX_DIGEST_SIZE

 -- Dati: blake2s.MAX_DIGEST_SIZE

Maximum digest size that the hash function can output.


File: python.info,  Node: Examples<14>,  Next: Credits,  Prev: Constants<5>,  Up: BLAKE2

5.15.1.12 Examples
..................

* Menu:

* Simple hashing::
* Using different digest sizes::
* Keyed hashing::
* Randomized hashing::
* Personalization::
* Tree mode::


File: python.info,  Node: Simple hashing,  Next: Using different digest sizes,  Up: Examples<14>

5.15.1.13 Simple hashing
........................

To calculate hash of some data, you should first construct a hash object
by calling the appropriate constructor function (*note blake2b(): 853.
or *note blake2s(): 854.), then update it with the data by calling *note
update(): 2fa6. on the object, and, finally, get the digest out of the
object by calling *note digest(): 2fa7. (or *note hexdigest(): 2fa8. for
hex-encoded string).

     >>> from hashlib import blake2b
     >>> h = blake2b()
     >>> h.update(b'Hello world')
     >>> h.hexdigest()
     '6ff843ba685842aa82031d3f53c48b66326df7639a63d128974c5c14f31a0f33343a8c65551134ed1ae0f2b0dd2bb495dc81039e3eeb0aa1bb0388bbeac29183'

As a shortcut, you can pass the first chunk of data to update directly
to the constructor as the positional argument:

     >>> from hashlib import blake2b
     >>> blake2b(b'Hello world').hexdigest()
     '6ff843ba685842aa82031d3f53c48b66326df7639a63d128974c5c14f31a0f33343a8c65551134ed1ae0f2b0dd2bb495dc81039e3eeb0aa1bb0388bbeac29183'

You can call *note hash.update(): 2fa6. as many times as you need to
iteratively update the hash:

     >>> from hashlib import blake2b
     >>> items = [b'Hello', b' ', b'world']
     >>> h = blake2b()
     >>> for item in items:
     ...     h.update(item)
     ...
     >>> h.hexdigest()
     '6ff843ba685842aa82031d3f53c48b66326df7639a63d128974c5c14f31a0f33343a8c65551134ed1ae0f2b0dd2bb495dc81039e3eeb0aa1bb0388bbeac29183'


File: python.info,  Node: Using different digest sizes,  Next: Keyed hashing,  Prev: Simple hashing,  Up: Examples<14>

5.15.1.14 Using different digest sizes
......................................

BLAKE2 has configurable size of digests up to 64 bytes for BLAKE2b and
up to 32 bytes for BLAKE2s.  For example, to replace SHA-1 with BLAKE2b
without changing the size of output, we can tell BLAKE2b to produce
20-byte digests:

     >>> from hashlib import blake2b
     >>> h = blake2b(digest_size=20)
     >>> h.update(b'Replacing SHA1 with the more secure function')
     >>> h.hexdigest()
     'd24f26cf8de66472d58d4e1b1774b4c9158b1f4c'
     >>> h.digest_size
     20
     >>> len(h.digest())
     20

Hash objects with different digest sizes have completely different
outputs (shorter hashes are 'not' prefixes of longer hashes); BLAKE2b
and BLAKE2s produce different outputs even if the output length is the
same:

     >>> from hashlib import blake2b, blake2s
     >>> blake2b(digest_size=10).hexdigest()
     '6fa1d8fcfd719046d762'
     >>> blake2b(digest_size=11).hexdigest()
     'eb6ec15daf9546254f0809'
     >>> blake2s(digest_size=10).hexdigest()
     '1bf21a98c78a1c376ae9'
     >>> blake2s(digest_size=11).hexdigest()
     '567004bf96e4a25773ebf4'


File: python.info,  Node: Keyed hashing,  Next: Randomized hashing,  Prev: Using different digest sizes,  Up: Examples<14>

5.15.1.15 Keyed hashing
.......................

Keyed hashing can be used for authentication as a faster and simpler
replacement for Hash-based message authentication code(1) (HMAC). BLAKE2
can be securely used in prefix-MAC mode thanks to the
indifferentiability property inherited from BLAKE.

This example shows how to get a (hex-encoded) 128-bit authentication
code for message ‘b'message data'’ with key ‘b'pseudorandom key'’:

     >>> from hashlib import blake2b
     >>> h = blake2b(key=b'pseudorandom key', digest_size=16)
     >>> h.update(b'message data')
     >>> h.hexdigest()
     '3d363ff7401e02026f4a4687d4863ced'

As a practical example, a web application can symmetrically sign cookies
sent to users and later verify them to make sure they weren’t tampered
with:

     >>> from hashlib import blake2b
     >>> from hmac import compare_digest
     >>>
     >>> SECRET_KEY = b'pseudorandomly generated server secret key'
     >>> AUTH_SIZE = 16
     >>>
     >>> def sign(cookie):
     ...     h = blake2b(digest_size=AUTH_SIZE, key=SECRET_KEY)
     ...     h.update(cookie)
     ...     return h.hexdigest().encode('utf-8')
     >>>
     >>> def verify(cookie, sig):
     ...     good_sig = sign(cookie)
     ...     return compare_digest(good_sig, sig)
     >>>
     >>> cookie = b'user-alice'
     >>> sig = sign(cookie)
     >>> print("{0},{1}".format(cookie.decode('utf-8'), sig))
     user-alice,b'43b3c982cf697e0c5ab22172d1ca7421'
     >>> verify(cookie, sig)
     True
     >>> verify(b'user-bob', sig)
     False
     >>> verify(cookie, b'0102030405060708090a0b0c0d0e0f00')
     False

Even though there’s a native keyed hashing mode, BLAKE2 can, of course,
be used in HMAC construction with *note hmac: 6e. module:

     >>> import hmac, hashlib
     >>> m = hmac.new(b'secret key', digestmod=hashlib.blake2s)
     >>> m.update(b'message')
     >>> m.hexdigest()
     'e3c8102868d28b5ff85fc35dda07329970d1a01e273c37481326fe0c861c8142'

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/HMAC


File: python.info,  Node: Randomized hashing,  Next: Personalization,  Prev: Keyed hashing,  Up: Examples<14>

5.15.1.16 Randomized hashing
............................

By setting 'salt' parameter users can introduce randomization to the
hash function.  Randomized hashing is useful for protecting against
collision attacks on the hash function used in digital signatures.

     Randomized hashing is designed for situations where one party, the
     message preparer, generates all or part of a message to be signed
     by a second party, the message signer.  If the message preparer is
     able to find cryptographic hash function collisions (i.e., two
     messages producing the same hash value), then they might prepare
     meaningful versions of the message that would produce the same hash
     value and digital signature, but with different results (e.g.,
     transferring $1,000,000 to an account, rather than $10).
     Cryptographic hash functions have been designed with collision
     resistance as a major goal, but the current concentration on
     attacking cryptographic hash functions may result in a given
     cryptographic hash function providing less collision resistance
     than expected.  Randomized hashing offers the signer additional
     protection by reducing the likelihood that a preparer can generate
     two or more messages that ultimately yield the same hash value
     during the digital signature generation process — even if it is
     practical to find collisions for the hash function.  However, the
     use of randomized hashing may reduce the amount of security
     provided by a digital signature when all portions of the message
     are prepared by the signer.

     (NIST SP-800-106 "Randomized Hashing for Digital Signatures"(1))

In BLAKE2 the salt is processed as a one-time input to the hash function
during initialization, rather than as an input to each compression
function.

     Avvertimento: 'Salted hashing' (or just hashing) with BLAKE2 or any
     other general-purpose cryptographic hash function, such as SHA-256,
     is not suitable for hashing passwords.  See BLAKE2 FAQ(2) for more
     information.

     >>> import os
     >>> from hashlib import blake2b
     >>> msg = b'some message'
     >>> # Calculate the first hash with a random salt.
     >>> salt1 = os.urandom(blake2b.SALT_SIZE)
     >>> h1 = blake2b(salt=salt1)
     >>> h1.update(msg)
     >>> # Calculate the second hash with a different random salt.
     >>> salt2 = os.urandom(blake2b.SALT_SIZE)
     >>> h2 = blake2b(salt=salt2)
     >>> h2.update(msg)
     >>> # The digests are different.
     >>> h1.digest() != h2.digest()
     True

   ---------- Footnotes ----------

   (1) https://csrc.nist.gov/pubs/sp/800/106/final

   (2) https://www.blake2.net/#qa


File: python.info,  Node: Personalization,  Next: Tree mode,  Prev: Randomized hashing,  Up: Examples<14>

5.15.1.17 Personalization
.........................

Sometimes it is useful to force hash function to produce different
digests for the same input for different purposes.  Quoting the authors
of the Skein hash function:

     We recommend that all application designers seriously consider
     doing this; we have seen many protocols where a hash that is
     computed in one part of the protocol can be used in an entirely
     different part because two hash computations were done on similar
     or related data, and the attacker can force the application to make
     the hash inputs the same.  Personalizing each hash function used in
     the protocol summarily stops this type of attack.

     (The Skein Hash Function Family(1), p.  21)

BLAKE2 can be personalized by passing bytes to the 'person' argument:

     >>> from hashlib import blake2b
     >>> FILES_HASH_PERSON = b'MyApp Files Hash'
     >>> BLOCK_HASH_PERSON = b'MyApp Block Hash'
     >>> h = blake2b(digest_size=32, person=FILES_HASH_PERSON)
     >>> h.update(b'the same content')
     >>> h.hexdigest()
     '20d9cd024d4fb086aae819a1432dd2466de12947831b75c5a30cf2676095d3b4'
     >>> h = blake2b(digest_size=32, person=BLOCK_HASH_PERSON)
     >>> h.update(b'the same content')
     >>> h.hexdigest()
     'cf68fb5761b9c44e7878bfb2c4c9aea52264a80b75005e65619778de59f383a3'

Personalization together with the keyed mode can also be used to derive
different keys from a single one.

     >>> from hashlib import blake2s
     >>> from base64 import b64decode, b64encode
     >>> orig_key = b64decode(b'Rm5EPJai72qcK3RGBpW3vPNfZy5OZothY+kHY6h21KM=')
     >>> enc_key = blake2s(key=orig_key, person=b'kEncrypt').digest()
     >>> mac_key = blake2s(key=orig_key, person=b'kMAC').digest()
     >>> print(b64encode(enc_key).decode('utf-8'))
     rbPb15S/Z9t+agffno5wuhB77VbRi6F9Iv2qIxU7WHw=
     >>> print(b64encode(mac_key).decode('utf-8'))
     G9GtHFE1YluXY1zWPlYk1e/nWfu0WSEb0KRcjhDeP/o=

   ---------- Footnotes ----------

   (1) https://www.schneier.com/wp-content/uploads/2016/02/skein.pdf


File: python.info,  Node: Tree mode,  Prev: Personalization,  Up: Examples<14>

5.15.1.18 Tree mode
...................

Here’s an example of hashing a minimal tree with two leaf nodes:

       10
      /  \
     00  01

This example uses 64-byte internal digests, and returns the 32-byte
final digest:

     >>> from hashlib import blake2b
     >>>
     >>> FANOUT = 2
     >>> DEPTH = 2
     >>> LEAF_SIZE = 4096
     >>> INNER_SIZE = 64
     >>>
     >>> buf = bytearray(6000)
     >>>
     >>> # Left leaf
     ... h00 = blake2b(buf[0:LEAF_SIZE], fanout=FANOUT, depth=DEPTH,
     ...               leaf_size=LEAF_SIZE, inner_size=INNER_SIZE,
     ...               node_offset=0, node_depth=0, last_node=False)
     >>> # Right leaf
     ... h01 = blake2b(buf[LEAF_SIZE:], fanout=FANOUT, depth=DEPTH,
     ...               leaf_size=LEAF_SIZE, inner_size=INNER_SIZE,
     ...               node_offset=1, node_depth=0, last_node=True)
     >>> # Root node
     ... h10 = blake2b(digest_size=32, fanout=FANOUT, depth=DEPTH,
     ...               leaf_size=LEAF_SIZE, inner_size=INNER_SIZE,
     ...               node_offset=0, node_depth=1, last_node=True)
     >>> h10.update(h00.digest())
     >>> h10.update(h01.digest())
     >>> h10.hexdigest()
     '3ad2a9b37c6070e374c7a8c508fe20ca86b6ed54e286e93a0318e95e881db5aa'


File: python.info,  Node: Credits,  Prev: Examples<14>,  Up: BLAKE2

5.15.1.19 Credits
.................

BLAKE2(1) was designed by 'Jean-Philippe Aumasson', 'Samuel Neves',
'Zooko Wilcox-O’Hearn', and 'Christian Winnerlein' based on SHA-3(2)
finalist BLAKE(3) created by 'Jean-Philippe Aumasson', 'Luca Henzen',
'Willi Meier', and 'Raphael C.-W. Phan'.

It uses core algorithm from ChaCha(4) cipher designed by 'Daniel J.
Bernstein'.

The stdlib implementation is based on pyblake2(5) module.  It was
written by 'Dmitry Chestnykh' based on C implementation written by
'Samuel Neves'.  The documentation was copied from pyblake2(6) and
written by 'Dmitry Chestnykh'.

The C code was partly rewritten for Python by 'Christian Heimes'.

The following public domain dedication applies for both C hash function
implementation, extension code, and this documentation:

     To the extent possible under law, the author(s) have dedicated all
     copyright and related and neighboring rights to this software to
     the public domain worldwide.  This software is distributed without
     any warranty.

     You should have received a copy of the CC0 Public Domain Dedication
     along with this software.  If not, see
     ‘https://creativecommons.org/publicdomain/zero/1.0/’.

The following people have helped with development or contributed their
changes to the project and the public domain according to the Creative
Commons Public Domain Dedication 1.0 Universal:

   * 'Alexandr Sokolovskiy'

Vedi anche
..........

Module *note hmac: 6e.

     A module to generate message authentication codes using hashes.

Module *note base64: f.

     Another way to encode binary hashes for non-binary environments.

‘https://nvlpubs.nist.gov/nistpubs/fips/nist.fips.180-4.pdf’

     The FIPS 180-4 publication on Secure Hash Algorithms.

‘https://csrc.nist.gov/pubs/fips/202/final’

     The FIPS 202 publication on the SHA-3 Standard.

‘https://www.blake2.net/’

     Official BLAKE2 website.

‘https://en.wikipedia.org/wiki/Cryptographic_hash_function’

     Wikipedia article with information on which algorithms have known
     issues and what that means regarding their use.

‘https://www.ietf.org/rfc/rfc8018.txt’

     PKCS #5: Password-Based Cryptography Specification Version 2.1

‘https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-132.pdf’

     NIST Recommendation for Password-Based Key Derivation.

   ---------- Footnotes ----------

   (1) https://www.blake2.net

   (2) https://en.wikipedia.org/wiki/Secure_Hash_Algorithms

   (3) 
https://web.archive.org/web/20200918190133/https://131002.net/blake/

   (4) https://cr.yp.to/chacha.html

   (5) https://pythonhosted.org/pyblake2/

   (6) https://pythonhosted.org/pyblake2/


File: python.info,  Node: hmac — Keyed-Hashing for Message Authentication,  Next: secrets — Generate secure random numbers for managing secrets,  Prev: hashlib — Secure hashes and message digests,  Up: Cryptographic Services

5.15.2 ‘hmac’ — Keyed-Hashing for Message Authentication
--------------------------------------------------------

'Source code:' Lib/hmac.py(1)

__________________________________________________________________

This module implements the HMAC algorithm as described by RFC 2104(2).
The interface allows to use any hash function with a 'fixed' digest
size.  In particular, extendable output functions such as SHAKE-128 or
SHAKE-256 cannot be used with HMAC.

 -- Funzione: hmac.new (key, msg=None, digestmod)

     Return a new hmac object.  'key' is a bytes or bytearray object
     giving the secret key.  If 'msg' is present, the method call
     ‘update(msg)’ is made.  'digestmod' is the digest name, digest
     constructor or module for the HMAC object to use.  It may be any
     name suitable to *note hashlib.new(): 1d16.  Despite its argument
     position, it is required.

     Cambiato nella versione 3.4: Parameter 'key' can be a bytes or
     bytearray object.  Parameter 'msg' can be of any type supported by
     *note hashlib: 6c.  Parameter 'digestmod' can be the name of a hash
     algorithm.

     Cambiato nella versione 3.8: The 'digestmod' argument is now
     required.  Pass it as a keyword argument to avoid awkwardness when
     you do not have an initial 'msg'.

 -- Funzione: hmac.digest (key, msg, digest)

     Return digest of 'msg' for given secret 'key' and 'digest'.  The
     function is equivalent to ‘HMAC(key, msg, digest).digest()’, but
     uses an optimized C or inline implementation, which is faster for
     messages that fit into memory.  The parameters 'key', 'msg', and
     'digest' have the same meaning as in *note new(): c98.

     CPython implementation detail, the optimized C implementation is
     only used when 'digest' is a string and name of a digest algorithm,
     which is supported by OpenSSL.

     Added in version 3.7.

 -- Classe: hmac.HMAC

     An HMAC object has the following methods:

 -- Metodo: HMAC.update (msg)

     Update the hmac object with 'msg'.  Repeated calls are equivalent
     to a single call with the concatenation of all the arguments:
     ‘m.update(a); m.update(b)’ is equivalent to ‘m.update(a + b)’.

     Cambiato nella versione 3.4: Parameter 'msg' can be of any type
     supported by *note hashlib: 6c.

 -- Metodo: HMAC.digest ()

     Return the digest of the bytes passed to the *note update(): 114b.
     method so far.  This bytes object will be the same length as the
     'digest_size' of the digest given to the constructor.  It may
     contain non-ASCII bytes, including NUL bytes.

          Avvertimento: When comparing the output of *note digest():
          d34. to an externally supplied digest during a verification
          routine, it is recommended to use the *note compare_digest():
          12d1. function instead of the ‘==’ operator to reduce the
          vulnerability to timing attacks.

 -- Metodo: HMAC.hexdigest ()

     Like *note digest(): d34. except the digest is returned as a string
     twice the length containing only hexadecimal digits.  This may be
     used to exchange the value safely in email or other non-binary
     environments.

          Avvertimento: When comparing the output of *note hexdigest():
          2fd1. to an externally supplied digest during a verification
          routine, it is recommended to use the *note compare_digest():
          12d1. function instead of the ‘==’ operator to reduce the
          vulnerability to timing attacks.

 -- Metodo: HMAC.copy ()

     Return a copy («clone») of the hmac object.  This can be used to
     efficiently compute the digests of strings that share a common
     initial substring.

A hash object has the following attributes:

 -- Attributo: HMAC.digest_size

     The size of the resulting HMAC digest in bytes.

 -- Attributo: HMAC.block_size

     The internal block size of the hash algorithm in bytes.

     Added in version 3.4.

 -- Attributo: HMAC.name

     The canonical name of this HMAC, always lowercase, e.g.
     ‘hmac-md5’.

     Added in version 3.4.

Cambiato nella versione 3.10: Removed the undocumented attributes
‘HMAC.digest_cons’, ‘HMAC.inner’, and ‘HMAC.outer’.

This module also provides the following helper function:

 -- Funzione: hmac.compare_digest (a, b)

     Return ‘a == b’.  This function uses an approach designed to
     prevent timing analysis by avoiding content-based short circuiting
     behaviour, making it appropriate for cryptography.  'a' and 'b'
     must both be of the same type: either *note str: 169. (ASCII only,
     as e.g.  returned by *note HMAC.hexdigest(): 2fd1.), or a *note
     bytes-like object: 193.

          Nota: If 'a' and 'b' are of different lengths, or if an error
          occurs, a timing attack could theoretically reveal information
          about the types and lengths of 'a' and 'b'—but not their
          values.

     Added in version 3.3.

     Cambiato nella versione 3.10: The function uses OpenSSL’s
     ‘CRYPTO_memcmp()’ internally when available.

Vedi anche
..........

Module *note hashlib: 6c.

     The Python module providing secure hash functions.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/hmac.py

   (2) https://datatracker.ietf.org/doc/html/rfc2104.html


File: python.info,  Node: secrets — Generate secure random numbers for managing secrets,  Prev: hmac — Keyed-Hashing for Message Authentication,  Up: Cryptographic Services

5.15.3 ‘secrets’ — Generate secure random numbers for managing secrets
----------------------------------------------------------------------

Added in version 3.6.

'Source code:' Lib/secrets.py(1)

__________________________________________________________________

The *note secrets: c5. module is used for generating cryptographically
strong random numbers suitable for managing data such as passwords,
account authentication, security tokens, and related secrets.

In particular, *note secrets: c5. should be used in preference to the
default pseudo-random number generator in the *note random: bd. module,
which is designed for modelling and simulation, not security or
cryptography.

Vedi anche
..........

PEP 506(2)

* Menu:

* Random numbers::
* Generating tokens::
* Other functions::
* Recipes and best practices::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/secrets.py

   (2) https://peps.python.org/pep-0506/


File: python.info,  Node: Random numbers,  Next: Generating tokens,  Up: secrets — Generate secure random numbers for managing secrets

5.15.3.1 Random numbers
.......................

The *note secrets: c5. module provides access to the most secure source
of randomness that your operating system provides.

 -- Classe: secrets.SystemRandom

     A class for generating random numbers using the highest-quality
     sources provided by the operating system.  See *note
     random.SystemRandom: 2b3d. for additional details.

 -- Funzione: secrets.choice (seq)

     Return a randomly chosen element from a non-empty sequence.

 -- Funzione: secrets.randbelow (exclusive_upper_bound)

     Return a random int in the range [0, 'exclusive_upper_bound').

 -- Funzione: secrets.randbits (k)

     Return a non-negative int with 'k' random bits.


File: python.info,  Node: Generating tokens,  Next: Other functions,  Prev: Random numbers,  Up: secrets — Generate secure random numbers for managing secrets

5.15.3.2 Generating tokens
..........................

The *note secrets: c5. module provides functions for generating secure
tokens, suitable for applications such as password resets, hard-to-guess
URLs, and similar.

 -- Funzione: secrets.token_bytes ([nbytes=None])

     Return a random byte string containing 'nbytes' number of bytes.
     If 'nbytes' is ‘None’ or not supplied, a reasonable default is
     used.

          >>> token_bytes(16)
          b'\xebr\x17D*t\xae\xd4\xe3S\xb6\xe2\xebP1\x8b'

 -- Funzione: secrets.token_hex ([nbytes=None])

     Return a random text string, in hexadecimal.  The string has
     'nbytes' random bytes, each byte converted to two hex digits.  If
     'nbytes' is ‘None’ or not supplied, a reasonable default is used.

          >>> token_hex(16)
          'f9bf78b9a18ce6d46a0cd2b0b86df9da'

 -- Funzione: secrets.token_urlsafe ([nbytes=None])

     Return a random URL-safe text string, containing 'nbytes' random
     bytes.  The text is Base64 encoded, so on average each byte results
     in approximately 1.3 characters.  If 'nbytes' is ‘None’ or not
     supplied, a reasonable default is used.

          >>> token_urlsafe(16)
          'Drmhze6EPcv0fN_81Bj-nA'

* Menu:

* How many bytes should tokens use?::


File: python.info,  Node: How many bytes should tokens use?,  Up: Generating tokens

5.15.3.3 How many bytes should tokens use?
..........................................

To be secure against brute-force attacks(1), tokens need to have
sufficient randomness.  Unfortunately, what is considered sufficient
will necessarily increase as computers get more powerful and able to
make more guesses in a shorter period.  As of 2015, it is believed that
32 bytes (256 bits) of randomness is sufficient for the typical use-case
expected for the *note secrets: c5. module.

For those who want to manage their own token length, you can explicitly
specify how much randomness is used for tokens by giving an *note int:
19b. argument to the various ‘token_*’ functions.  That argument is
taken as the number of bytes of randomness to use.

Otherwise, if no argument is provided, or if the argument is ‘None’, the
‘token_*’ functions will use a reasonable default instead.

     Nota: That default is subject to change at any time, including
     during maintenance releases.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Brute-force_attack


File: python.info,  Node: Other functions,  Next: Recipes and best practices,  Prev: Generating tokens,  Up: secrets — Generate secure random numbers for managing secrets

5.15.3.4 Other functions
........................

 -- Funzione: secrets.compare_digest (a, b)

     Return ‘True’ if strings or *note bytes-like objects: 193. 'a' and
     'b' are equal, otherwise ‘False’, using a «constant-time compare»
     to reduce the risk of timing attacks(1).  See *note
     hmac.compare_digest(): 12d1. for additional details.

   ---------- Footnotes ----------

   (1) https://codahale.com/a-lesson-in-timing-attacks/


File: python.info,  Node: Recipes and best practices,  Prev: Other functions,  Up: secrets — Generate secure random numbers for managing secrets

5.15.3.5 Recipes and best practices
...................................

This section shows recipes and best practices for using *note secrets:
c5. to manage a basic level of security.

Generate an eight-character alphanumeric password:

     import string
     import secrets
     alphabet = string.ascii_letters + string.digits
     password = ''.join(secrets.choice(alphabet) for i in range(8))

     Nota: Applications should not store passwords in a recoverable
     format(1), whether plain text or encrypted.  They should be salted
     and hashed using a cryptographically strong one-way (irreversible)
     hash function.

Generate a ten-character alphanumeric password with at least one
lowercase character, at least one uppercase character, and at least
three digits:

     import string
     import secrets
     alphabet = string.ascii_letters + string.digits
     while True:
         password = ''.join(secrets.choice(alphabet) for i in range(10))
         if (any(c.islower() for c in password)
                 and any(c.isupper() for c in password)
                 and sum(c.isdigit() for c in password) >= 3):
             break

Generate an XKCD-style passphrase(2):

     import secrets
     # On standard Linux systems, use a convenient dictionary file.
     # Other platforms may need to provide their own word-list.
     with open('/usr/share/dict/words') as f:
         words = [word.strip() for word in f]
         password = ' '.join(secrets.choice(words) for i in range(4))

Generate a hard-to-guess temporary URL containing a security token
suitable for password recovery applications:

     import secrets
     url = 'https://example.com/reset=' + secrets.token_urlsafe()

   ---------- Footnotes ----------

   (1) https://cwe.mitre.org/data/definitions/257.html

   (2) https://xkcd.com/936/


File: python.info,  Node: Generic Operating System Services,  Next: Command-line interface libraries,  Prev: Cryptographic Services,  Up: The Python Standard Library

5.16 Generic Operating System Services
======================================

The modules described in this chapter provide interfaces to operating
system features that are available on (almost) all operating systems,
such as files and a clock.  The interfaces are generally modeled after
the Unix or C interfaces, but they are available on most other systems
as well.  Here’s an overview:

* Menu:

* os — Miscellaneous operating system interfaces::
* io — Core tools for working with streams::
* time — Time access and conversions::
* logging — Logging facility for Python::
* logging.config — Logging configuration: logging config — Logging configuration.
* logging.handlers — Logging handlers: logging handlers — Logging handlers.
* platform — Access to underlying platform’s identifying data::
* errno — Standard errno system symbols::
* ctypes — A foreign function library for Python::


File: python.info,  Node: os — Miscellaneous operating system interfaces,  Next: io — Core tools for working with streams,  Up: Generic Operating System Services

5.16.1 ‘os’ — Miscellaneous operating system interfaces
-------------------------------------------------------

'Source code:' Lib/os.py(1)

__________________________________________________________________

This module provides a portable way of using operating system dependent
functionality.  If you just want to read or write a file see *note
open(): 316, if you want to manipulate paths, see the *note os.path: a6.
module, and if you want to read all the lines in all the files on the
command line see the *note fileinput: 5f. module.  For creating
temporary files and directories see the *note tempfile: e6. module, and
for high-level file and directory handling see the *note shutil: ca.
module.

Notes on the availability of these functions:

   * The design of all built-in operating system dependent modules of
     Python is such that as long as the same functionality is available,
     it uses the same interface; for example, the function
     ‘os.stat(path)’ returns stat information about 'path' in the same
     format (which happens to have originated with the POSIX interface).

   * Extensions peculiar to a particular operating system are also
     available through the *note os: a5. module, but using them is of
     course a threat to portability.

   * All functions accepting path or file names accept both bytes and
     string objects, and result in an object of the same type, if a path
     or file name is returned.

   * On VxWorks, os.popen, os.fork, os.execv and os.spawn*p* are not
     supported.

   * On WebAssembly platforms, Android and iOS, large parts of the *note
     os: a5. module are not available or behave differently.  APIs
     related to processes (e.g.  *note fork(): 4b6, *note execve():
     1301.) and resources (e.g.  *note nice(): 1309.) are not available.
     Others like *note getuid(): 17ff. and *note getpid(): 2fe6. are
     emulated or stubs.  WebAssembly platforms also lack support for
     signals (e.g.  *note kill(): 156f, *note wait(): f9a.).

     Nota: All functions in this module raise *note OSError: 2c0. (or
     subclasses thereof) in the case of invalid or inaccessible file
     names and paths, or other arguments that have the correct type, but
     are not accepted by the operating system.

 -- Eccezione: os.error

     An alias for the built-in *note OSError: 2c0. exception.

 -- Dati: os.name

     The name of the operating system dependent module imported.  The
     following names have currently been registered: ‘'posix'’, ‘'nt'’,
     ‘'java'’.

     Vedi anche
     ..........

     *note sys.platform: 291. has a finer granularity.  *note
     os.uname(): 131e. gives system-dependent version information.

     The *note platform: af. module provides detailed checks for the
     system’s identity.

* Menu:

* File Names, Command Line Arguments, and Environment Variables: File Names Command Line Arguments and Environment Variables.
* Python UTF-8 Mode::
* Process Parameters::
* File Object Creation::
* File Descriptor Operations::
* Files and Directories::
* Process Management::
* Interface to the scheduler::
* Miscellaneous System Information::
* Random numbers: Random numbers<2>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/os.py


File: python.info,  Node: File Names Command Line Arguments and Environment Variables,  Next: Python UTF-8 Mode,  Up: os — Miscellaneous operating system interfaces

5.16.1.1 File Names, Command Line Arguments, and Environment Variables
......................................................................

In Python, file names, command line arguments, and environment variables
are represented using the string type.  On some systems, decoding these
strings to and from bytes is necessary before passing them to the
operating system.  Python uses the *note filesystem encoding and error
handler: 75e. to perform this conversion (see *note
sys.getfilesystemencoding(): e55.).

The *note filesystem encoding and error handler: 75e. are configured at
Python startup by the *note PyConfig_Read(): 994. function: see *note
filesystem_encoding: 41b. and *note filesystem_errors: 41c. members of
*note PyConfig: 3f7.

Cambiato nella versione 3.1: On some systems, conversion using the file
system encoding may fail.  In this case, Python uses the *note
surrogateescape encoding error handler: 2837, which means that
undecodable bytes are replaced by a Unicode character U+DC'xx' on
decoding, and these are again translated to the original byte on
encoding.

The *note file system encoding: 75e. must guarantee to successfully
decode all bytes below 128.  If the file system encoding fails to
provide this guarantee, API functions can raise *note UnicodeError: 462.

See also the *note locale encoding: 54b.


File: python.info,  Node: Python UTF-8 Mode,  Next: Process Parameters,  Prev: File Names Command Line Arguments and Environment Variables,  Up: os — Miscellaneous operating system interfaces

5.16.1.2 Python UTF-8 Mode
..........................

Added in version 3.7: See PEP 540(1) for more details.

The Python UTF-8 Mode ignores the *note locale encoding: 54b. and forces
the usage of the UTF-8 encoding:

   * Use UTF-8 as the *note filesystem encoding: 75e.

   * *note sys.getfilesystemencoding(): e55. returns ‘'utf-8'’.

   * *note locale.getpreferredencoding(): 75d. returns ‘'utf-8'’ (the
     'do_setlocale' argument has no effect).

   * *note sys.stdin: 760, *note sys.stdout: ccf, and *note sys.stderr:
     b35. all use UTF-8 as their text encoding, with the
     ‘surrogateescape’ *note error handler: 1b57. being enabled for
     *note sys.stdin: 760. and *note sys.stdout: ccf. (*note sys.stderr:
     b35. continues to use ‘backslashreplace’ as it does in the default
     locale-aware mode)

   * On Unix, *note os.device_encoding(): 1c1d. returns ‘'utf-8'’ rather
     than the device encoding.

Note that the standard stream settings in UTF-8 mode can be overridden
by *note PYTHONIOENCODING: 120c. (just as they can be in the default
locale-aware mode).

As a consequence of the changes in those lower level APIs, other higher
level APIs also exhibit different default behaviours:

   * Command line arguments, environment variables and filenames are
     decoded to text using the UTF-8 encoding.

   * *note os.fsdecode(): e50. and *note os.fsencode(): e51. use the
     UTF-8 encoding.

   * *note open(): 316, *note io.open(): 741, and *note codecs.open():
     315. use the UTF-8 encoding by default.  However, they still use
     the strict error handler by default so that attempting to open a
     binary file in text mode is likely to raise an exception rather
     than producing nonsense data.

The *note Python UTF-8 Mode: 867. is enabled if the LC_CTYPE locale is
‘C’ or ‘POSIX’ at Python startup (see the *note PyConfig_Read(): 994.
function).

It can be enabled or disabled using the *note -X utf8: 16f. command line
option and the *note PYTHONUTF8: cd1. environment variable.

If the *note PYTHONUTF8: cd1. environment variable is not set at all,
then the interpreter defaults to using the current locale settings,
'unless' the current locale is identified as a legacy ASCII-based locale
(as described for *note PYTHONCOERCECLOCALE: cce.), and locale coercion
is either disabled or fails.  In such legacy locales, the interpreter
will default to enabling UTF-8 mode unless explicitly instructed not to
do so.

The Python UTF-8 Mode can only be enabled at the Python startup.  Its
value can be read from *note sys.flags.utf8_mode: 89d.

See also the *note UTF-8 mode on Windows: 2206. and the *note filesystem
encoding and error handler: 75e.

Vedi anche
..........

PEP 686(2)

     Python 3.15 will make *note Python UTF-8 Mode: 867. default.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0540/

   (2) https://peps.python.org/pep-0686/


File: python.info,  Node: Process Parameters,  Next: File Object Creation,  Prev: Python UTF-8 Mode,  Up: os — Miscellaneous operating system interfaces

5.16.1.3 Process Parameters
...........................

These functions and data items provide information and operate on the
current process and user.

 -- Funzione: os.ctermid ()

     Return the filename corresponding to the controlling terminal of
     the process.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.environ

     A *note mapping: 13c3. object where keys and values are strings
     that represent the process environment.  For example,
     ‘environ['HOME']’ is the pathname of your home directory (on some
     platforms), and is equivalent to ‘getenv("HOME")’ in C.

     This mapping is captured the first time the *note os: a5. module is
     imported, typically during Python startup as part of processing
     ‘site.py’.  Changes to the environment made after this time are not
     reflected in *note os.environ: 259, except for changes made by
     modifying *note os.environ: 259. directly.

     This mapping may be used to modify the environment as well as query
     the environment.  *note putenv(): 25b. will be called automatically
     when the mapping is modified.

     On Unix, keys and values use *note sys.getfilesystemencoding():
     e55. and ‘'surrogateescape'’ error handler.  Use *note environb:
     25a. if you would like to use a different encoding.

     On Windows, the keys are converted to uppercase.  This also applies
     when getting, setting, or deleting an item.  For example,
     ‘environ['monty'] = 'python'’ maps the key ‘'MONTY'’ to the value
     ‘'python'’.

          Nota: Calling *note putenv(): 25b. directly does not change
          *note os.environ: 259, so it’s better to modify *note
          os.environ: 259.

          Nota: On some platforms, including FreeBSD and macOS, setting
          ‘environ’ may cause memory leaks.  Refer to the system
          documentation for ‘putenv()’.

     You can delete items in this mapping to unset environment
     variables.  *note unsetenv(): 25c. will be called automatically
     when an item is deleted from *note os.environ: 259, and when one of
     the ‘pop()’ or ‘clear()’ methods is called.

     Vedi anche
     ..........

     The *note os.reload_environ(): 258. function.

     Cambiato nella versione 3.9: Updated to support PEP 584(1)’s merge
     (‘|’) and update (‘|=’) operators.

 -- Dati: os.environb

     Bytes version of *note environ: 259.: a *note mapping: 13c3. object
     where both keys and values are *note bytes: 192. objects
     representing the process environment.  *note environ: 259. and
     *note environb: 25a. are synchronized (modifying *note environb:
     25a. updates *note environ: 259, and vice versa).

     *note environb: 25a. is only available if *note
     supports_bytes_environ: 141d. is ‘True’.

     Added in version 3.2.

     Cambiato nella versione 3.9: Updated to support PEP 584(2)’s merge
     (‘|’) and update (‘|=’) operators.

 -- Funzione: os.reload_environ ()

     The *note os.environ: 259. and *note os.environb: 25a. mappings are
     a cache of environment variables at the time that Python started.
     As such, changes to the current process environment are not
     reflected if made outside Python, or by *note os.putenv(): 25b. or
     *note os.unsetenv(): 25c.  Use ‘os.reload_environ()’ to update
     *note os.environ: 259. and *note os.environb: 25a. with any such
     changes to the current process environment.

          Avvertimento: This function is not thread-safe.  Calling it
          while the environment is being modified in an other thread is
          an undefined behavior.  Reading from *note os.environ: 259. or
          *note os.environb: 25a, or calling *note os.getenv(): 2fee.
          while reloading, may return an empty result.

     Added in version 3.14.

 -- Funzione: os.chdir (path)

 -- Funzione: os.fchdir (fd)

 -- Funzione: os.getcwd ()

     These functions are described in *note Files and Directories: 2fef.

 -- Funzione: os.fsencode (filename)

     Encode *note path-like: 5a1. 'filename' to the *note filesystem
     encoding and error handler: 75e.; return *note bytes: 192.
     unchanged.

     *note fsdecode(): e50. is the reverse function.

     Added in version 3.2.

     Cambiato nella versione 3.6: Support added to accept objects
     implementing the *note os.PathLike: e4d. interface.

 -- Funzione: os.fsdecode (filename)

     Decode the *note path-like: 5a1. 'filename' from the *note
     filesystem encoding and error handler: 75e.; return *note str: 169.
     unchanged.

     *note fsencode(): e51. is the reverse function.

     Added in version 3.2.

     Cambiato nella versione 3.6: Support added to accept objects
     implementing the *note os.PathLike: e4d. interface.

 -- Funzione: os.fspath (path)

     Return the file system representation of the path.

     If *note str: 169. or *note bytes: 192. is passed in, it is
     returned unchanged.  Otherwise *note __fspath__(): e4e. is called
     and its value is returned as long as it is a *note str: 169. or
     *note bytes: 192. object.  In all other cases, *note TypeError:
     198. is raised.

     Added in version 3.6.

 -- Classe: os.PathLike

     An *note abstract base class: 13be. for objects representing a file
     system path, e.g.  *note pathlib.PurePath: 6ce.

     Added in version 3.6.

      -- Metodo: abstractmethod __fspath__ ()

          Return the file system path representation of the object.

          The method should only return a *note str: 169. or *note
          bytes: 192. object, with the preference being for *note str:
          169.

 -- Funzione: os.getenv (key, default=None)

     Return the value of the environment variable 'key' as a string if
     it exists, or 'default' if it doesn’t.  'key' is a string.  Note
     that since *note getenv(): 2fee. uses *note os.environ: 259, the
     mapping of *note getenv(): 2fee. is similarly also captured on
     import, and the function may not reflect future environment
     changes.

     On Unix, keys and values are decoded with *note
     sys.getfilesystemencoding(): e55. and ‘'surrogateescape'’ error
     handler.  Use *note os.getenvb(): 141e. if you would like to use a
     different encoding.

     *note Availability: 2128.: Unix, Windows.

 -- Funzione: os.getenvb (key, default=None)

     Return the value of the environment variable 'key' as bytes if it
     exists, or 'default' if it doesn’t.  'key' must be bytes.  Note
     that since *note getenvb(): 141e. uses *note os.environb: 25a, the
     mapping of *note getenvb(): 141e. is similarly also captured on
     import, and the function may not reflect future environment
     changes.

     *note getenvb(): 141e. is only available if *note
     supports_bytes_environ: 141d. is ‘True’.

     *note Availability: 2128.: Unix.

     Added in version 3.2.

 -- Funzione: os.get_exec_path (env=None)

     Returns the list of directories that will be searched for a named
     executable, similar to a shell, when launching a process.  'env',
     when specified, should be an environment variable dictionary to
     lookup the PATH in.  By default, when 'env' is ‘None’, *note
     environ: 259. is used.

     Added in version 3.2.

 -- Funzione: os.getegid ()

     Return the effective group id of the current process.  This
     corresponds to the «set id» bit on the file being executed in the
     current process.

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.geteuid ()

     Return the current process’s effective user id.

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.getgid ()

     Return the real group id of the current process.

     *note Availability: 2128.: Unix.

     The function is a stub on WASI, see *note WebAssembly platforms:
     1b52. for more information.

 -- Funzione: os.getgrouplist (user, group, /)

     Return list of group ids that 'user' belongs to.  If 'group' is not
     in the list, it is included; typically, 'group' is specified as the
     group ID field from the password record for 'user', because that
     group ID will otherwise be potentially omitted.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.3.

 -- Funzione: os.getgroups ()

     Return list of supplemental group ids associated with the current
     process.

     *note Availability: 2128.: Unix, not WASI.

          Nota: On macOS, *note getgroups(): 2ff3. behavior differs
          somewhat from other Unix platforms.  If the Python interpreter
          was built with a deployment target of ‘10.5’ or earlier, *note
          getgroups(): 2ff3. returns the list of effective group ids
          associated with the current user process; this list is limited
          to a system-defined number of entries, typically 16, and may
          be modified by calls to *note setgroups(): 2ff4. if suitably
          privileged.  If built with a deployment target greater than
          ‘10.5’, *note getgroups(): 2ff3. returns the current group
          access list for the user associated with the effective user id
          of the process; the group access list may change over the
          lifetime of the process, it is not affected by calls to *note
          setgroups(): 2ff4, and its length is not limited to 16.  The
          deployment target value, ‘MACOSX_DEPLOYMENT_TARGET’, can be
          obtained with *note sysconfig.get_config_var(): 174.

 -- Funzione: os.getlogin ()

     Return the name of the user logged in on the controlling terminal
     of the process.  For most purposes, it is more useful to use *note
     getpass.getuser(): 65a. since the latter checks the environment
     variables ‘LOGNAME’ or ‘USERNAME’ to find out who the user is, and
     falls back to ‘pwd.getpwuid(os.getuid())[0]’ to get the login name
     of the current real user id.

     *note Availability: 2128.: Unix, Windows, not WASI.

 -- Funzione: os.getpgid (pid)

     Return the process group id of the process with process id 'pid'.
     If 'pid' is 0, the process group id of the current process is
     returned.

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.getpgrp ()

     Return the id of the current process group.

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.getpid ()

     Return the current process id.

     The function is a stub on WASI, see *note WebAssembly platforms:
     1b52. for more information.

 -- Funzione: os.getppid ()

     Return the parent’s process id.  When the parent process has
     exited, on Unix the id returned is the one of the init process (1),
     on Windows it is still the same id, which may be already reused by
     another process.

     *note Availability: 2128.: Unix, Windows, not WASI.

     Cambiato nella versione 3.2: Added support for Windows.

 -- Funzione: os.getpriority (which, who)

     Get program scheduling priority.  The value 'which' is one of *note
     PRIO_PROCESS: 2ff7, *note PRIO_PGRP: 2ff8, or *note PRIO_USER:
     2ff9, and 'who' is interpreted relative to 'which' (a process
     identifier for *note PRIO_PROCESS: 2ff7, process group identifier
     for *note PRIO_PGRP: 2ff8, and a user ID for *note PRIO_USER:
     2ff9.).  A zero value for 'who' denotes (respectively) the calling
     process, the process group of the calling process, or the real user
     ID of the calling process.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.3.

 -- Dati: os.PRIO_PROCESS
 -- Dati: os.PRIO_PGRP
 -- Dati: os.PRIO_USER

     Parameters for the *note getpriority(): 1307. and *note
     setpriority(): 1308. functions.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.3.

 -- Dati: os.PRIO_DARWIN_THREAD
 -- Dati: os.PRIO_DARWIN_PROCESS
 -- Dati: os.PRIO_DARWIN_BG
 -- Dati: os.PRIO_DARWIN_NONUI

     Parameters for the *note getpriority(): 1307. and *note
     setpriority(): 1308. functions.

     *note Availability: 2128.: macOS

     Added in version 3.12.

 -- Funzione: os.getresuid ()

     Return a tuple (ruid, euid, suid) denoting the current process’s
     real, effective, and saved user ids.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.2.

 -- Funzione: os.getresgid ()

     Return a tuple (rgid, egid, sgid) denoting the current process’s
     real, effective, and saved group ids.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.2.

 -- Funzione: os.getuid ()

     Return the current process’s real user id.

     *note Availability: 2128.: Unix.

     The function is a stub on WASI, see *note WebAssembly platforms:
     1b52. for more information.

 -- Funzione: os.initgroups (username, gid, /)

     Call the system ‘initgroups()’ to initialize the group access list
     with all of the groups of which the specified username is a member,
     plus the specified group id.

     *note Availability: 2128.: Unix, not WASI, not Android.

     Added in version 3.2.

 -- Funzione: os.putenv (key, value, /)

     Set the environment variable named 'key' to the string 'value'.
     Such changes to the environment affect subprocesses started with
     *note os.system(): 1664, *note popen(): 31a. or *note fork(): 4b6.
     and *note execv(): 2ffe.

     Assignments to items in *note os.environ: 259. are automatically
     translated into corresponding calls to *note putenv(): 25b.;
     however, calls to *note putenv(): 25b. don’t update *note
     os.environ: 259, so it is actually preferable to assign to items of
     *note os.environ: 259.  This also applies to *note getenv(): 2fee.
     and *note getenvb(): 141e, which respectively use *note os.environ:
     259. and *note os.environb: 25a. in their implementations.

     See also the *note os.reload_environ(): 258. function.

          Nota: On some platforms, including FreeBSD and macOS, setting
          ‘environ’ may cause memory leaks.  Refer to the system
          documentation for ‘putenv()’.

     Raises an *note auditing event: 1c56. ‘os.putenv’ with arguments
     ‘key’, ‘value’.

     Cambiato nella versione 3.9: The function is now always available.

 -- Funzione: os.setegid (egid, /)

     Set the current process’s effective group id.

     *note Availability: 2128.: Unix, not WASI, not Android.

 -- Funzione: os.seteuid (euid, /)

     Set the current process’s effective user id.

     *note Availability: 2128.: Unix, not WASI, not Android.

 -- Funzione: os.setgid (gid, /)

     Set the current process” group id.

     *note Availability: 2128.: Unix, not WASI, not Android.

 -- Funzione: os.setgroups (groups, /)

     Set the list of supplemental group ids associated with the current
     process to 'groups'.  'groups' must be a sequence, and each element
     must be an integer identifying a group.  This operation is
     typically available only to the superuser.

     *note Availability: 2128.: Unix, not WASI.

          Nota: On macOS, the length of 'groups' may not exceed the
          system-defined maximum number of effective group ids,
          typically 16.  See the documentation for *note getgroups():
          2ff3. for cases where it may not return the same group list
          set by calling setgroups().

 -- Funzione: os.setns (fd, nstype=0)

     Reassociate the current thread with a Linux namespace.  See the
     ‘setns(2)(3)’ and ‘namespaces(7)(4)’ man pages for more details.

     If 'fd' refers to a ‘/proc/`pid'/ns/’ link, ‘setns()’ reassociates
     the calling thread with the namespace associated with that link,
     and 'nstype' may be set to one of the *note CLONE_NEW* constants:
     3002. to impose constraints on the operation (‘0’ means no
     constraints).

     Since Linux 5.8, 'fd' may refer to a PID file descriptor obtained
     from *note pidfd_open(): 6a5.  In this case, ‘setns()’ reassociates
     the calling thread into one or more of the same namespaces as the
     thread referred to by 'fd'.  This is subject to any constraints
     imposed by 'nstype', which is a bit mask combining one or more of
     the *note CLONE_NEW* constants: 3002, e.g.  ‘setns(fd,
     os.CLONE_NEWUTS | os.CLONE_NEWPID)’.  The caller’s memberships in
     unspecified namespaces are left unchanged.

     'fd' can be any object with a *note fileno(): 1795. method, or a
     raw file descriptor.

     This example reassociates the thread with the ‘init’ process’s
     network namespace:

          fd = os.open("/proc/1/ns/net", os.O_RDONLY)
          os.setns(fd, os.CLONE_NEWNET)
          os.close(fd)

     *note Availability: 2128.: Linux >= 3.0 with glibc >= 2.14.

     Added in version 3.12.

     Vedi anche
     ..........

     The *note unshare(): 1b2a. function.

 -- Funzione: os.setpgrp ()

     Call the system call ‘setpgrp()’ or ‘setpgrp(0, 0)’ depending on
     which version is implemented (if any).  See the Unix manual for the
     semantics.

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.setpgid (pid, pgrp, /)

     Call the system call ‘setpgid()’ to set the process group id of the
     process with id 'pid' to the process group with id 'pgrp'.  See the
     Unix manual for the semantics.

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.setpriority (which, who, priority)

     Set program scheduling priority.  The value 'which' is one of *note
     PRIO_PROCESS: 2ff7, *note PRIO_PGRP: 2ff8, or *note PRIO_USER:
     2ff9, and 'who' is interpreted relative to 'which' (a process
     identifier for *note PRIO_PROCESS: 2ff7, process group identifier
     for *note PRIO_PGRP: 2ff8, and a user ID for *note PRIO_USER:
     2ff9.).  A zero value for 'who' denotes (respectively) the calling
     process, the process group of the calling process, or the real user
     ID of the calling process.  'priority' is a value in the range -20
     to 19.  The default priority is 0; lower priorities cause more
     favorable scheduling.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.3.

 -- Funzione: os.setregid (rgid, egid, /)

     Set the current process’s real and effective group ids.

     *note Availability: 2128.: Unix, not WASI, not Android.

 -- Funzione: os.setresgid (rgid, egid, sgid, /)

     Set the current process’s real, effective, and saved group ids.

     *note Availability: 2128.: Unix, not WASI, not Android.

     Added in version 3.2.

 -- Funzione: os.setresuid (ruid, euid, suid, /)

     Set the current process’s real, effective, and saved user ids.

     *note Availability: 2128.: Unix, not WASI, not Android.

     Added in version 3.2.

 -- Funzione: os.setreuid (ruid, euid, /)

     Set the current process’s real and effective user ids.

     *note Availability: 2128.: Unix, not WASI, not Android.

 -- Funzione: os.getsid (pid, /)

     Call the system call ‘getsid()’.  See the Unix manual for the
     semantics.

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.setsid ()

     Call the system call ‘setsid()’.  See the Unix manual for the
     semantics.

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.setuid (uid, /)

     Set the current process’s user id.

     *note Availability: 2128.: Unix, not WASI, not Android.

 -- Funzione: os.strerror (code, /)

     Return the error message corresponding to the error code in 'code'.
     On platforms where ‘strerror()’ returns ‘NULL’ when given an
     unknown error number, *note ValueError: 2ec. is raised.

 -- Dati: os.supports_bytes_environ

     ‘True’ if the native OS type of the environment is bytes (eg.
     ‘False’ on Windows).

     Added in version 3.2.

 -- Funzione: os.umask (mask, /)

     Set the current numeric umask and return the previous umask.

     The function is a stub on WASI, see *note WebAssembly platforms:
     1b52. for more information.

 -- Funzione: os.uname ()

     Returns information identifying the current operating system.  The
     return value is an object with five attributes:

        * ‘sysname’ - operating system name

        * ‘nodename’ - name of machine on network
          (implementation-defined)

        * ‘release’ - operating system release

        * ‘version’ - operating system version

        * ‘machine’ - hardware identifier

     For backwards compatibility, this object is also iterable, behaving
     like a five-tuple containing ‘sysname’, ‘nodename’, ‘release’,
     ‘version’, and ‘machine’ in that order.

     Some systems truncate ‘nodename’ to 8 characters or to the leading
     component; a better way to get the hostname is *note
     socket.gethostname(): 300b. or even
     ‘socket.gethostbyaddr(socket.gethostname())’.

     On macOS, iOS and Android, this returns the 'kernel' name and
     version (i.e., ‘'Darwin'’ on macOS and iOS; ‘'Linux'’ on Android).
     *note platform.uname(): 1dfb. can be used to get the user-facing
     operating system name and version on iOS and Android.

     *note Availability: 2128.: Unix.

     Cambiato nella versione 3.3: Return type changed from a tuple to a
     tuple-like object with named attributes.

 -- Funzione: os.unsetenv (key, /)

     Unset (delete) the environment variable named 'key'.  Such changes
     to the environment affect subprocesses started with *note
     os.system(): 1664, *note popen(): 31a. or *note fork(): 4b6. and
     *note execv(): 2ffe.

     Deletion of items in *note os.environ: 259. is automatically
     translated into a corresponding call to *note unsetenv(): 25c.;
     however, calls to *note unsetenv(): 25c. don’t update *note
     os.environ: 259, so it is actually preferable to delete items of
     *note os.environ: 259.

     See also the *note os.reload_environ(): 258. function.

     Raises an *note auditing event: 1c56. ‘os.unsetenv’ with argument
     ‘key’.

     Cambiato nella versione 3.9: The function is now always available
     and is also available on Windows.

 -- Funzione: os.unshare (flags)

     Disassociate parts of the process execution context, and move them
     into a newly created namespace.  See the ‘unshare(2)(5)’ man page
     for more details.  The 'flags' argument is a bit mask, combining
     zero or more of the *note CLONE_* constants: 3002, that specifies
     which parts of the execution context should be unshared from their
     existing associations and moved to a new namespace.  If the 'flags'
     argument is ‘0’, no changes are made to the calling process’s
     execution context.

     *note Availability: 2128.: Linux >= 2.6.16.

     Added in version 3.12.

     Vedi anche
     ..........

     The *note setns(): 1b29. function.

Flags to the *note unshare(): 1b2a. function, if the implementation
supports them.  See ‘unshare(2)(6)’ in the Linux manual for their exact
effect and availability.

 -- Dati: os.CLONE_FILES
 -- Dati: os.CLONE_FS
 -- Dati: os.CLONE_NEWCGROUP
 -- Dati: os.CLONE_NEWIPC
 -- Dati: os.CLONE_NEWNET
 -- Dati: os.CLONE_NEWNS
 -- Dati: os.CLONE_NEWPID
 -- Dati: os.CLONE_NEWTIME
 -- Dati: os.CLONE_NEWUSER
 -- Dati: os.CLONE_NEWUTS
 -- Dati: os.CLONE_SIGHAND
 -- Dati: os.CLONE_SYSVSEM
 -- Dati: os.CLONE_THREAD
 -- Dati: os.CLONE_VM

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0584/

   (2) https://peps.python.org/pep-0584/

   (3) https://manpages.debian.org/setns(2)

   (4) https://manpages.debian.org/namespaces(7)

   (5) https://manpages.debian.org/unshare(2)

   (6) https://manpages.debian.org/unshare(2)


File: python.info,  Node: File Object Creation,  Next: File Descriptor Operations,  Prev: Process Parameters,  Up: os — Miscellaneous operating system interfaces

5.16.1.4 File Object Creation
.............................

These functions create new *note file objects: 13cb.  (See also *note
open(): f94. for opening file descriptors.)

 -- Funzione: os.fdopen (fd, *args, **kwargs)

     Return an open file object connected to the file descriptor 'fd'.
     This is an alias of the *note open(): 316. built-in function and
     accepts the same arguments.  The only difference is that the first
     argument of *note fdopen(): 2367. must always be an integer.


File: python.info,  Node: File Descriptor Operations,  Next: Files and Directories,  Prev: File Object Creation,  Up: os — Miscellaneous operating system interfaces

5.16.1.5 File Descriptor Operations
...................................

These functions operate on I/O streams referenced using file
descriptors.

File descriptors are small integers corresponding to a file that has
been opened by the current process.  For example, standard input is
usually file descriptor 0, standard output is 1, and standard error is
2.  Further files opened by a process will then be assigned 3, 4, 5, and
so forth.  The name «file descriptor» is slightly deceptive; on Unix
platforms, sockets and pipes are also referenced by file descriptors.

The *note fileno(): 1795. method can be used to obtain the file
descriptor associated with a *note file object: 13cb. when required.
Note that using the file descriptor directly will bypass the file object
methods, ignoring aspects such as internal buffering of data.

 -- Funzione: os.close (fd)

     Close file descriptor 'fd'.

          Nota: This function is intended for low-level I/O and must be
          applied to a file descriptor as returned by *note os.open():
          f94. or *note pipe(): 1b4c.  To close a «file object» returned
          by the built-in function *note open(): 316. or by *note
          popen(): 31a. or *note fdopen(): 2367, use its *note close():
          507. method.

 -- Funzione: os.closerange (fd_low, fd_high, /)

     Close all file descriptors from 'fd_low' (inclusive) to 'fd_high'
     (exclusive), ignoring errors.  Equivalent to (but much faster
     than):

          for fd in range(fd_low, fd_high):
              try:
                  os.close(fd)
              except OSError:
                  pass

 -- Funzione: os.copy_file_range (src, dst, count, offset_src=None,
          offset_dst=None)

     Copy 'count' bytes from file descriptor 'src', starting from offset
     'offset_src', to file descriptor 'dst', starting from offset
     'offset_dst'.  If 'offset_src' is ‘None’, then 'src' is read from
     the current position; respectively for 'offset_dst'.

     In Linux kernel older than 5.3, the files pointed to by 'src' and
     'dst' must reside in the same filesystem, otherwise an *note
     OSError: 2c0. is raised with *note errno: 179b. set to *note
     errno.EXDEV: 301f.

     This copy is done without the additional cost of transferring data
     from the kernel to user space and then back into the kernel.
     Additionally, some filesystems could implement extra optimizations,
     such as the use of reflinks (i.e., two or more inodes that share
     pointers to the same copy-on-write disk blocks; supported file
     systems include btrfs and XFS) and server-side copy (in the case of
     NFS).

     The function copies bytes between two file descriptors.  Text
     options, like the encoding and the line ending, are ignored.

     The return value is the amount of bytes copied.  This could be less
     than the amount requested.

          Nota: On Linux, *note os.copy_file_range(): 189c. should not
          be used for copying a range of a pseudo file from a special
          filesystem like procfs and sysfs.  It will always copy no
          bytes and return 0 as if the file was empty because of a known
          Linux kernel issue.

     *note Availability: 2128.: Linux >= 4.5 with glibc >= 2.27.

     Added in version 3.8.

 -- Funzione: os.device_encoding (fd)

     Return a string describing the encoding of the device associated
     with 'fd' if it is connected to a terminal; else return *note None:
     886.

     On Unix, if the *note Python UTF-8 Mode: 867. is enabled, return
     ‘'UTF-8'’ rather than the device encoding.

     Cambiato nella versione 3.10: On Unix, the function now implements
     the Python UTF-8 Mode.

 -- Funzione: os.dup (fd, /)

     Return a duplicate of file descriptor 'fd'.  The new file
     descriptor is *note non-inheritable: 10fe.

     On Windows, when duplicating a standard stream (0: stdin, 1:
     stdout, 2: stderr), the new file descriptor is *note inheritable:
     10fe.

     *note Availability: 2128.: not WASI.

     Cambiato nella versione 3.4: The new file descriptor is now
     non-inheritable.

 -- Funzione: os.dup2 (fd, fd2, inheritable=True)

     Duplicate file descriptor 'fd' to 'fd2', closing the latter first
     if necessary.  Return 'fd2'.  The new file descriptor is *note
     inheritable: 10fe. by default or non-inheritable if 'inheritable'
     is ‘False’.

     *note Availability: 2128.: not WASI.

     Cambiato nella versione 3.4: Add the optional 'inheritable'
     parameter.

     Cambiato nella versione 3.7: Return 'fd2' on success.  Previously,
     ‘None’ was always returned.

 -- Funzione: os.fchmod (fd, mode)

     Change the mode of the file given by 'fd' to the numeric 'mode'.
     See the docs for *note chmod(): 52a. for possible values of 'mode'.
     As of Python 3.3, this is equivalent to ‘os.chmod(fd, mode)’.

     Raises an *note auditing event: 1c56. ‘os.chmod’ with arguments
     ‘path’, ‘mode’, ‘dir_fd’.

     *note Availability: 2128.: Unix, Windows.

     The function is limited on WASI, see *note WebAssembly platforms:
     1b52. for more information.

     Cambiato nella versione 3.13: Added support on Windows.

 -- Funzione: os.fchown (fd, uid, gid)

     Change the owner and group id of the file given by 'fd' to the
     numeric 'uid' and 'gid'.  To leave one of the ids unchanged, set it
     to -1.  See *note chown(): 12f6.  As of Python 3.3, this is
     equivalent to ‘os.chown(fd, uid, gid)’.

     Raises an *note auditing event: 1c56. ‘os.chown’ with arguments
     ‘path’, ‘uid’, ‘gid’, ‘dir_fd’.

     *note Availability: 2128.: Unix.

     The function is limited on WASI, see *note WebAssembly platforms:
     1b52. for more information.

 -- Funzione: os.fdatasync (fd)

     Force write of file with filedescriptor 'fd' to disk.  Does not
     force update of metadata.

     *note Availability: 2128.: Unix.

          Nota: This function is not available on MacOS.

 -- Funzione: os.fpathconf (fd, name, /)

     Return system configuration information relevant to an open file.
     'name' specifies the configuration value to retrieve; it may be a
     string which is the name of a defined system value; these names are
     specified in a number of standards (POSIX.1, Unix 95, Unix 98, and
     others).  Some platforms define additional names as well.  The
     names known to the host operating system are given in the
     ‘pathconf_names’ dictionary.  For configuration variables not
     included in that mapping, passing an integer for 'name' is also
     accepted.

     If 'name' is a string and is not known, *note ValueError: 2ec. is
     raised.  If a specific value for 'name' is not supported by the
     host system, even if it is included in ‘pathconf_names’, an *note
     OSError: 2c0. is raised with *note errno.EINVAL: 1dba. for the
     error number.

     As of Python 3.3, this is equivalent to ‘os.pathconf(fd, name)’.

     *note Availability: 2128.: Unix.

 -- Funzione: os.fstat (fd)

     Get the status of the file descriptor 'fd'.  Return a *note
     stat_result: 16c8. object.

     As of Python 3.3, this is equivalent to ‘os.stat(fd)’.

     Vedi anche
     ..........

     The *note stat(): 26d. function.

 -- Funzione: os.fstatvfs (fd, /)

     Return information about the filesystem containing the file
     associated with file descriptor 'fd', like *note statvfs(): 1304.
     As of Python 3.3, this is equivalent to ‘os.statvfs(fd)’.

     *note Availability: 2128.: Unix.

 -- Funzione: os.fsync (fd)

     Force write of file with filedescriptor 'fd' to disk.  On Unix,
     this calls the native ‘fsync()’ function; on Windows, the MS
     ‘_commit()’ function.

     If you’re starting with a buffered Python *note file object: 13cb.
     'f', first do ‘f.flush()’, and then do ‘os.fsync(f.fileno())’, to
     ensure that all internal buffers associated with 'f' are written to
     disk.

     *note Availability: 2128.: Unix, Windows.

 -- Funzione: os.ftruncate (fd, length, /)

     Truncate the file corresponding to file descriptor 'fd', so that it
     is at most 'length' bytes in size.  As of Python 3.3, this is
     equivalent to ‘os.truncate(fd, length)’.

     Raises an *note auditing event: 1c56. ‘os.truncate’ with arguments
     ‘fd’, ‘length’.

     *note Availability: 2128.: Unix, Windows.

     Cambiato nella versione 3.5: Added support for Windows

 -- Funzione: os.get_blocking (fd, /)

     Get the blocking mode of the file descriptor: ‘False’ if the *note
     O_NONBLOCK: 103d. flag is set, ‘True’ if the flag is cleared.

     See also *note set_blocking(): 103c. and *note
     socket.socket.setblocking(): 3021.

     *note Availability: 2128.: Unix, Windows.

     The function is limited on WASI, see *note WebAssembly platforms:
     1b52. for more information.

     On Windows, this function is limited to pipes.

     Added in version 3.5.

     Cambiato nella versione 3.12: Added support for pipes on Windows.

 -- Funzione: os.grantpt (fd, /)

     Grant access to the slave pseudo-terminal device associated with
     the master pseudo-terminal device to which the file descriptor 'fd'
     refers.  The file descriptor 'fd' is not closed upon failure.

     Calls the C standard library function ‘grantpt()’.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.13.

 -- Funzione: os.isatty (fd, /)

     Return ‘True’ if the file descriptor 'fd' is open and connected to
     a tty(-like) device, else ‘False’.

 -- Funzione: os.lockf (fd, cmd, len, /)

     Apply, test or remove a POSIX lock on an open file descriptor.
     'fd' is an open file descriptor.  'cmd' specifies the command to
     use - one of *note F_LOCK: 3022, *note F_TLOCK: 3023, *note
     F_ULOCK: 3024. or *note F_TEST: 3025.  'len' specifies the section
     of the file to lock.

     Raises an *note auditing event: 1c56. ‘os.lockf’ with arguments
     ‘fd’, ‘cmd’, ‘len’.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Dati: os.F_LOCK
 -- Dati: os.F_TLOCK
 -- Dati: os.F_ULOCK
 -- Dati: os.F_TEST

     Flags that specify what action *note lockf(): 131b. will take.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Funzione: os.login_tty (fd, /)

     Prepare the tty of which fd is a file descriptor for a new login
     session.  Make the calling process a session leader; make the tty
     the controlling tty, the stdin, the stdout, and the stderr of the
     calling process; close fd.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.11.

 -- Funzione: os.lseek (fd, pos, whence, /)

     Set the current position of file descriptor 'fd' to position 'pos',
     modified by 'whence', and return the new position in bytes relative
     to the start of the file.  Valid values for 'whence' are:

        * *note SEEK_SET: 1495. or ‘0’ – set 'pos' relative to the
          beginning of the file

        * *note SEEK_CUR: 1496. or ‘1’ – set 'pos' relative to the
          current file position

        * *note SEEK_END: 1497. or ‘2’ – set 'pos' relative to the end
          of the file

        * *note SEEK_HOLE: 3026. – set 'pos' to the next data location,
          relative to 'pos'

        * *note SEEK_DATA: 3027. – set 'pos' to the next data hole,
          relative to 'pos'

     Cambiato nella versione 3.3: Add support for ‘SEEK_HOLE’ and
     ‘SEEK_DATA’.

 -- Dati: os.SEEK_SET
 -- Dati: os.SEEK_CUR
 -- Dati: os.SEEK_END

     Parameters to the *note lseek(): 131f. function and the *note
     seek(): 1494. method on *note file-like objects: 13cb, for whence
     to adjust the file position indicator.

     *note SEEK_SET: 1495.

          Adjust the file position relative to the beginning of the
          file.

     *note SEEK_CUR: 1496.

          Adjust the file position relative to the current file
          position.

     *note SEEK_END: 1497.

          Adjust the file position relative to the end of the file.

     Their values are 0, 1, and 2, respectively.

 -- Dati: os.SEEK_HOLE
 -- Dati: os.SEEK_DATA

     Parameters to the *note lseek(): 131f. function and the *note
     seek(): 1494. method on *note file-like objects: 13cb, for seeking
     file data and holes on sparsely allocated files.

     ‘SEEK_DATA’

          Adjust the file offset to the next location containing data,
          relative to the seek position.

     ‘SEEK_HOLE’

          Adjust the file offset to the next location containing a hole,
          relative to the seek position.  A hole is defined as a
          sequence of zeros.

          Nota: These operations only make sense for filesystems that
          support them.

     *note Availability: 2128.: Linux >= 3.1, macOS, Unix

     Added in version 3.3.

 -- Funzione: os.open (path, flags, mode=0o777, *, dir_fd=None)

     Open the file 'path' and set various flags according to 'flags' and
     possibly its mode according to 'mode'.  When computing 'mode', the
     current umask value is first masked out.  Return the file
     descriptor for the newly opened file.  The new file descriptor is
     *note non-inheritable: 10fe.

     For a description of the flag and mode values, see the C run-time
     documentation; flag constants (like *note O_RDONLY: 3028. and *note
     O_WRONLY: 3029.) are defined in the *note os: a5. module.  In
     particular, on Windows adding *note O_BINARY: 302a. is needed to
     open files in binary mode.

     This function can support *note paths relative to directory
     descriptors: 12f2. with the 'dir_fd' parameter.

     Raises an *note auditing event: 1c56. ‘open’ with arguments ‘path’,
     ‘mode’, ‘flags’.

     Cambiato nella versione 3.4: The new file descriptor is now
     non-inheritable.

          Nota: This function is intended for low-level I/O. For normal
          usage, use the built-in function *note open(): 316, which
          returns a *note file object: 13cb. with ‘read()’ and ‘write()’
          methods (and many more).  To wrap a file descriptor in a file
          object, use *note fdopen(): 2367.

     Cambiato nella versione 3.3: Added the 'dir_fd' parameter.

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the function now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(1) for the
     rationale).

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

The following constants are options for the 'flags' parameter to the
*note open(): f94. function.  They can be combined using the bitwise OR
operator ‘|’.  Some of them are not available on all platforms.  For
descriptions of their availability and use, consult the ‘open(2)(2)’
manual page on Unix or the MSDN(3) on Windows.

 -- Dati: os.O_RDONLY
 -- Dati: os.O_WRONLY
 -- Dati: os.O_RDWR
 -- Dati: os.O_APPEND
 -- Dati: os.O_CREAT
 -- Dati: os.O_EXCL
 -- Dati: os.O_TRUNC

     The above constants are available on Unix and Windows.

 -- Dati: os.O_DSYNC
 -- Dati: os.O_RSYNC
 -- Dati: os.O_SYNC
 -- Dati: os.O_NDELAY
 -- Dati: os.O_NONBLOCK
 -- Dati: os.O_NOCTTY
 -- Dati: os.O_CLOEXEC

     The above constants are only available on Unix.

     Cambiato nella versione 3.3: Add *note O_CLOEXEC: 127e. constant.

 -- Dati: os.O_BINARY
 -- Dati: os.O_NOINHERIT
 -- Dati: os.O_SHORT_LIVED
 -- Dati: os.O_TEMPORARY
 -- Dati: os.O_RANDOM
 -- Dati: os.O_SEQUENTIAL
 -- Dati: os.O_TEXT

     The above constants are only available on Windows.

 -- Dati: os.O_EVTONLY
 -- Dati: os.O_FSYNC
 -- Dati: os.O_SYMLINK
 -- Dati: os.O_NOFOLLOW_ANY

     The above constants are only available on macOS.

     Cambiato nella versione 3.10: Add *note O_EVTONLY: a1d, *note
     O_FSYNC: a1e, *note O_SYMLINK: a1f. and *note O_NOFOLLOW_ANY: a20.
     constants.

 -- Dati: os.O_ASYNC
 -- Dati: os.O_DIRECT
 -- Dati: os.O_DIRECTORY
 -- Dati: os.O_NOFOLLOW
 -- Dati: os.O_NOATIME
 -- Dati: os.O_PATH
 -- Dati: os.O_TMPFILE
 -- Dati: os.O_SHLOCK
 -- Dati: os.O_EXLOCK

     The above constants are extensions and not present if they are not
     defined by the C library.

     Cambiato nella versione 3.4: Add *note O_PATH: 1174. on systems
     that support it.  Add *note O_TMPFILE: 1175, only available on
     Linux Kernel 3.11 or newer.

 -- Funzione: os.openpty ()

     Open a new pseudo-terminal pair.  Return a pair of file descriptors
     ‘(master, slave)’ for the pty and the tty, respectively.  The new
     file descriptors are *note non-inheritable: 10fe.  For a (slightly)
     more portable approach, use the *note pty: b6. module.

     *note Availability: 2128.: Unix, not WASI.

     Cambiato nella versione 3.4: The new file descriptors are now
     non-inheritable.

 -- Funzione: os.pipe ()

     Create a pipe.  Return a pair of file descriptors ‘(r, w)’ usable
     for reading and writing, respectively.  The new file descriptor is
     *note non-inheritable: 10fe.

     *note Availability: 2128.: Unix, Windows.

     Cambiato nella versione 3.4: The new file descriptors are now
     non-inheritable.

 -- Funzione: os.pipe2 (flags, /)

     Create a pipe with 'flags' set atomically.  'flags' can be
     constructed by ORing together one or more of these values: *note
     O_NONBLOCK: 103d, *note O_CLOEXEC: 127e.  Return a pair of file
     descriptors ‘(r, w)’ usable for reading and writing, respectively.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.3.

 -- Funzione: os.posix_fallocate (fd, offset, len, /)

     Ensures that enough disk space is allocated for the file specified
     by 'fd' starting from 'offset' and continuing for 'len' bytes.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Funzione: os.posix_fadvise (fd, offset, len, advice, /)

     Announces an intention to access data in a specific pattern thus
     allowing the kernel to make optimizations.  The advice applies to
     the region of the file specified by 'fd' starting at 'offset' and
     continuing for 'len' bytes.  'advice' is one of *note
     POSIX_FADV_NORMAL: 3040, *note POSIX_FADV_SEQUENTIAL: 3041, *note
     POSIX_FADV_RANDOM: 3042, *note POSIX_FADV_NOREUSE: 3043, *note
     POSIX_FADV_WILLNEED: 3044. or *note POSIX_FADV_DONTNEED: 3045.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Dati: os.POSIX_FADV_NORMAL
 -- Dati: os.POSIX_FADV_SEQUENTIAL
 -- Dati: os.POSIX_FADV_RANDOM
 -- Dati: os.POSIX_FADV_NOREUSE
 -- Dati: os.POSIX_FADV_WILLNEED
 -- Dati: os.POSIX_FADV_DONTNEED

     Flags that can be used in 'advice' in *note posix_fadvise(): f95.
     that specify the access pattern that is likely to be used.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Funzione: os.pread (fd, n, offset, /)

     Read at most 'n' bytes from file descriptor 'fd' at a position of
     'offset', leaving the file offset unchanged.

     Return a bytestring containing the bytes read.  If the end of the
     file referred to by 'fd' has been reached, an empty bytes object is
     returned.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Funzione: os.posix_openpt (oflag, /)

     Open and return a file descriptor for a master pseudo-terminal
     device.

     Calls the C standard library function ‘posix_openpt()’.  The
     'oflag' argument is used to set file status flags and file access
     modes as specified in the manual page of ‘posix_openpt()’ of your
     system.

     The returned file descriptor is *note non-inheritable: 10fe.  If
     the value *note O_CLOEXEC: 127e. is available on the system, it is
     added to 'oflag'.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.13.

 -- Funzione: os.preadv (fd, buffers, offset, flags=0, /)

     Read from a file descriptor 'fd' at a position of 'offset' into
     mutable *note bytes-like objects: 193. 'buffers', leaving the file
     offset unchanged.  Transfer data into each buffer until it is full
     and then move on to the next buffer in the sequence to hold the
     rest of the data.

     The flags argument contains a bitwise OR of zero or more of the
     following flags:

        - *note RWF_HIPRI: 3046.

        - *note RWF_NOWAIT: 3047.

     Return the total number of bytes actually read which can be less
     than the total capacity of all the objects.

     The operating system may set a limit (*note sysconf(): 18d5. value
     ‘'SC_IOV_MAX'’) on the number of buffers that can be used.

     Combine the functionality of *note os.readv(): d57. and *note
     os.pread(): d58.

     *note Availability: 2128.: Linux >= 2.6.30, FreeBSD >= 6.0, OpenBSD
     >= 2.7, AIX >= 7.1.

     Using flags requires Linux >= 4.6.

     Added in version 3.7.

 -- Dati: os.RWF_NOWAIT

     Do not wait for data which is not immediately available.  If this
     flag is specified, the system call will return instantly if it
     would have to read data from the backing storage or wait for a
     lock.

     If some data was successfully read, it will return the number of
     bytes read.  If no bytes were read, it will return ‘-1’ and set
     errno to *note errno.EAGAIN: 26e0.

     *note Availability: 2128.: Linux >= 4.14.

     Added in version 3.7.

 -- Dati: os.RWF_HIPRI

     High priority read/write.  Allows block-based filesystems to use
     polling of the device, which provides lower latency, but may use
     additional resources.

     Currently, on Linux, this feature is usable only on a file
     descriptor opened using the *note O_DIRECT: 303b. flag.

     *note Availability: 2128.: Linux >= 4.6.

     Added in version 3.7.

 -- Funzione: os.ptsname (fd, /)

     Return the name of the slave pseudo-terminal device associated with
     the master pseudo-terminal device to which the file descriptor 'fd'
     refers.  The file descriptor 'fd' is not closed upon failure.

     Calls the reentrant C standard library function ‘ptsname_r()’ if it
     is available; otherwise, the C standard library function
     ‘ptsname()’, which is not guaranteed to be thread-safe, is called.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.13.

 -- Funzione: os.pwrite (fd, str, offset, /)

     Write the bytestring in 'str' to file descriptor 'fd' at position
     of 'offset', leaving the file offset unchanged.

     Return the number of bytes actually written.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Funzione: os.pwritev (fd, buffers, offset, flags=0, /)

     Write the 'buffers' contents to file descriptor 'fd' at an offset
     'offset', leaving the file offset unchanged.  'buffers' must be a
     sequence of *note bytes-like objects: 193.  Buffers are processed
     in array order.  Entire contents of the first buffer is written
     before proceeding to the second, and so on.

     The flags argument contains a bitwise OR of zero or more of the
     following flags:

        - *note RWF_DSYNC: 3048.

        - *note RWF_SYNC: 3049.

        - *note RWF_APPEND: 1d15.

     Return the total number of bytes actually written.

     The operating system may set a limit (*note sysconf(): 18d5. value
     ‘'SC_IOV_MAX'’) on the number of buffers that can be used.

     Combine the functionality of *note os.writev(): d5a. and *note
     os.pwrite(): d5b.

     *note Availability: 2128.: Linux >= 2.6.30, FreeBSD >= 6.0, OpenBSD
     >= 2.7, AIX >= 7.1.

     Using flags requires Linux >= 4.6.

     Added in version 3.7.

 -- Dati: os.RWF_DSYNC

     Provide a per-write equivalent of the *note O_DSYNC: 302f. *note
     os.open(): f94. flag.  This flag effect applies only to the data
     range written by the system call.

     *note Availability: 2128.: Linux >= 4.7.

     Added in version 3.7.

 -- Dati: os.RWF_SYNC

     Provide a per-write equivalent of the *note O_SYNC: 3031. *note
     os.open(): f94. flag.  This flag effect applies only to the data
     range written by the system call.

     *note Availability: 2128.: Linux >= 4.7.

     Added in version 3.7.

 -- Dati: os.RWF_APPEND

     Provide a per-write equivalent of the *note O_APPEND: 302c. *note
     os.open(): f94. flag.  This flag is meaningful only for *note
     os.pwritev(): d59, and its effect applies only to the data range
     written by the system call.  The 'offset' argument does not affect
     the write operation; the data is always appended to the end of the
     file.  However, if the 'offset' argument is ‘-1’, the current file
     'offset' is updated.

     *note Availability: 2128.: Linux >= 4.16.

     Added in version 3.10.

 -- Funzione: os.read (fd, n, /)

     Read at most 'n' bytes from file descriptor 'fd'.

     Return a bytestring containing the bytes read.  If the end of the
     file referred to by 'fd' has been reached, an empty bytes object is
     returned.

          Nota: This function is intended for low-level I/O and must be
          applied to a file descriptor as returned by *note os.open():
          f94. or *note pipe(): 1b4c.  To read a «file object» returned
          by the built-in function *note open(): 316. or by *note
          popen(): 31a. or *note fdopen(): 2367, or *note sys.stdin:
          760, use its ‘read()’ or ‘readline()’ methods.

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the function now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(4) for the
     rationale).

 -- Funzione: os.readinto (fd, buffer, /)

     Read from a file descriptor 'fd' into a mutable *note buffer
     object: 260. 'buffer'.

     The 'buffer' should be mutable and *note bytes-like: 193.  On
     success, returns the number of bytes read.  Less bytes may be read
     than the size of the buffer.  The underlying system call will be
     retried when interrupted by a signal, unless the signal handler
     raises an exception.  Other errors will not be retried and an error
     will be raised.

     Returns 0 if 'fd' is at end of file or if the provided 'buffer' has
     length 0 (which can be used to check for errors without reading
     data).  Never returns negative.

          Nota: This function is intended for low-level I/O and must be
          applied to a file descriptor as returned by *note os.open():
          f94. or *note os.pipe(): 1b4c.  To read a «file object»
          returned by the built-in function *note open(): 316, or *note
          sys.stdin: 760, use its member functions, for example *note
          io.BufferedIOBase.readinto(): 187d, *note
          io.BufferedIOBase.read(): 1530, or *note io.TextIOBase.read():
          2056.

     Added in version 3.14.

 -- Funzione: os.sendfile (out_fd, in_fd, offset, count)

 -- Funzione: os.sendfile (out_fd, in_fd, offset, count, headers=(),
          trailers=(), flags=0)

     Copy 'count' bytes from file descriptor 'in_fd' to file descriptor
     'out_fd' starting at 'offset'.  Return the number of bytes sent.
     When EOF is reached return ‘0’.

     The first function notation is supported by all platforms that
     define *note sendfile(): d07.

     On Linux, if 'offset' is given as ‘None’, the bytes are read from
     the current position of 'in_fd' and the position of 'in_fd' is
     updated.

     The second case may be used on macOS and FreeBSD where 'headers'
     and 'trailers' are arbitrary sequences of buffers that are written
     before and after the data from 'in_fd' is written.  It returns the
     same as the first case.

     On macOS and FreeBSD, a value of ‘0’ for 'count' specifies to send
     until the end of 'in_fd' is reached.

     All platforms support sockets as 'out_fd' file descriptor, and some
     platforms allow other types (e.g.  regular file, pipe) as well.

     Cross-platform applications should not use 'headers', 'trailers'
     and 'flags' arguments.

     *note Availability: 2128.: Unix, not WASI.

          Nota: For a higher-level wrapper of *note sendfile(): d07, see
          *note socket.socket.sendfile(): 105f.

     Added in version 3.3.

     Cambiato nella versione 3.9: Parameters 'out' and 'in' was renamed
     to 'out_fd' and 'in_fd'.

 -- Dati: os.SF_NODISKIO
 -- Dati: os.SF_MNOWAIT
 -- Dati: os.SF_SYNC

     Parameters to the *note sendfile(): d07. function, if the
     implementation supports them.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.3.

 -- Dati: os.SF_NOCACHE

     Parameter to the *note sendfile(): d07. function, if the
     implementation supports it.  The data won’t be cached in the
     virtual memory and will be freed afterwards.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.11.

 -- Funzione: os.set_blocking (fd, blocking, /)

     Set the blocking mode of the specified file descriptor.  Set the
     *note O_NONBLOCK: 103d. flag if blocking is ‘False’, clear the flag
     otherwise.

     See also *note get_blocking(): 103b. and *note
     socket.socket.setblocking(): 3021.

     *note Availability: 2128.: Unix, Windows.

     The function is limited on WASI, see *note WebAssembly platforms:
     1b52. for more information.

     On Windows, this function is limited to pipes.

     Added in version 3.5.

     Cambiato nella versione 3.12: Added support for pipes on Windows.

 -- Funzione: os.splice (src, dst, count, offset_src=None,
          offset_dst=None, flags=0)

     Transfer 'count' bytes from file descriptor 'src', starting from
     offset 'offset_src', to file descriptor 'dst', starting from offset
     'offset_dst'.

     The splicing behaviour can be modified by specifying a 'flags'
     value.  Any of the following variables may used, combined using
     bitwise OR (the ‘|’ operator):

        * If *note SPLICE_F_MOVE: 304e. is specified, the kernel is
          asked to move pages instead of copying, but pages may still be
          copied if the kernel cannot move the pages from the pipe.

        * If *note SPLICE_F_NONBLOCK: 304f. is specified, the kernel is
          asked to not block on I/O. This makes the splice pipe
          operations nonblocking, but splice may nevertheless block
          because the spliced file descriptors may block.

        * If *note SPLICE_F_MORE: 3050. is specified, it hints to the
          kernel that more data will be coming in a subsequent splice.

     At least one of the file descriptors must refer to a pipe.  If
     'offset_src' is ‘None’, then 'src' is read from the current
     position; respectively for 'offset_dst'.  The offset associated to
     the file descriptor that refers to a pipe must be ‘None’.  The
     files pointed to by 'src' and 'dst' must reside in the same
     filesystem, otherwise an *note OSError: 2c0. is raised with *note
     errno: 179b. set to *note errno.EXDEV: 301f.

     This copy is done without the additional cost of transferring data
     from the kernel to user space and then back into the kernel.
     Additionally, some filesystems could implement extra optimizations.
     The copy is done as if both files are opened as binary.

     Upon successful completion, returns the number of bytes spliced to
     or from the pipe.  A return value of 0 means end of input.  If
     'src' refers to a pipe, then this means that there was no data to
     transfer, and it would not make sense to block because there are no
     writers connected to the write end of the pipe.

     Vedi anche
     ..........

     The ‘splice(2)(5)’ man page.

     *note Availability: 2128.: Linux >= 2.6.17 with glibc >= 2.5

     Added in version 3.10.

 -- Dati: os.SPLICE_F_MOVE
 -- Dati: os.SPLICE_F_NONBLOCK
 -- Dati: os.SPLICE_F_MORE

     Added in version 3.10.

 -- Funzione: os.readv (fd, buffers, /)

     Read from a file descriptor 'fd' into a number of mutable *note
     bytes-like objects: 193. 'buffers'.  Transfer data into each buffer
     until it is full and then move on to the next buffer in the
     sequence to hold the rest of the data.

     Return the total number of bytes actually read which can be less
     than the total capacity of all the objects.

     The operating system may set a limit (*note sysconf(): 18d5. value
     ‘'SC_IOV_MAX'’) on the number of buffers that can be used.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Funzione: os.tcgetpgrp (fd, /)

     Return the process group associated with the terminal given by 'fd'
     (an open file descriptor as returned by *note os.open(): f94.).

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.tcsetpgrp (fd, pg, /)

     Set the process group associated with the terminal given by 'fd'
     (an open file descriptor as returned by *note os.open(): f94.) to
     'pg'.

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.ttyname (fd, /)

     Return a string which specifies the terminal device associated with
     file descriptor 'fd'.  If 'fd' is not associated with a terminal
     device, an exception is raised.

     *note Availability: 2128.: Unix.

 -- Funzione: os.unlockpt (fd, /)

     Unlock the slave pseudo-terminal device associated with the master
     pseudo-terminal device to which the file descriptor 'fd' refers.
     The file descriptor 'fd' is not closed upon failure.

     Calls the C standard library function ‘unlockpt()’.

     *note Availability: 2128.: Unix, not WASI.

     Added in version 3.13.

 -- Funzione: os.write (fd, str, /)

     Write the bytestring in 'str' to file descriptor 'fd'.

     Return the number of bytes actually written.

          Nota: This function is intended for low-level I/O and must be
          applied to a file descriptor as returned by *note os.open():
          f94. or *note pipe(): 1b4c.  To write a «file object» returned
          by the built-in function *note open(): 316. or by *note
          popen(): 31a. or *note fdopen(): 2367, or *note sys.stdout:
          ccf. or *note sys.stderr: b35, use its ‘write()’ method.

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the function now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(6) for the
     rationale).

 -- Funzione: os.writev (fd, buffers, /)

     Write the contents of 'buffers' to file descriptor 'fd'.  'buffers'
     must be a sequence of *note bytes-like objects: 193.  Buffers are
     processed in array order.  Entire contents of the first buffer is
     written before proceeding to the second, and so on.

     Returns the total number of bytes actually written.

     The operating system may set a limit (*note sysconf(): 18d5. value
     ‘'SC_IOV_MAX'’) on the number of buffers that can be used.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

* Menu:

* Querying the size of a terminal::
* Inheritance of File Descriptors::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0475/

   (2) https://manpages.debian.org/open(2)

   (3) https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx

   (4) https://peps.python.org/pep-0475/

   (5) https://manpages.debian.org/splice(2)

   (6) https://peps.python.org/pep-0475/


File: python.info,  Node: Querying the size of a terminal,  Next: Inheritance of File Descriptors,  Up: File Descriptor Operations

5.16.1.6 Querying the size of a terminal
........................................

Added in version 3.3.

 -- Funzione: os.get_terminal_size (fd=STDOUT_FILENO, /)

     Return the size of the terminal window as ‘(columns, lines)’, tuple
     of type *note terminal_size: 2ce2.

     The optional argument ‘fd’ (default ‘STDOUT_FILENO’, or standard
     output) specifies which file descriptor should be queried.

     If the file descriptor is not connected to a terminal, an *note
     OSError: 2c0. is raised.

     *note shutil.get_terminal_size(): 130b. is the high-level function
     which should normally be used, ‘os.get_terminal_size’ is the
     low-level implementation.

     *note Availability: 2128.: Unix, Windows.

 -- Classe: os.terminal_size

     A subclass of tuple, holding ‘(columns, lines)’ of the terminal
     window size.

      -- Attributo: columns

          Width of the terminal window in characters.

      -- Attributo: lines

          Height of the terminal window in characters.


File: python.info,  Node: Inheritance of File Descriptors,  Prev: Querying the size of a terminal,  Up: File Descriptor Operations

5.16.1.7 Inheritance of File Descriptors
........................................

Added in version 3.4.

A file descriptor has an «inheritable» flag which indicates if the file
descriptor can be inherited by child processes.  Since Python 3.4, file
descriptors created by Python are non-inheritable by default.

On UNIX, non-inheritable file descriptors are closed in child processes
at the execution of a new program, other file descriptors are inherited.
Note that non-inheritable file descriptors are still 'inherited' by
child processes on *note os.fork(): 4b6.

On Windows, non-inheritable handles and file descriptors are closed in
child processes, except for standard streams (file descriptors 0, 1 and
2: stdin, stdout and stderr), which are always inherited.  Using *note
spawn*: 31b. functions, all inheritable handles and all inheritable file
descriptors are inherited.  Using the *note subprocess: dc. module, all
file descriptors except standard streams are closed, and inheritable
handles are only inherited if the 'close_fds' parameter is ‘False’.

On WebAssembly platforms, the file descriptor cannot be modified.

 -- Funzione: os.get_inheritable (fd, /)

     Get the «inheritable» flag of the specified file descriptor (a
     boolean).

 -- Funzione: os.set_inheritable (fd, inheritable, /)

     Set the «inheritable» flag of the specified file descriptor.

 -- Funzione: os.get_handle_inheritable (handle, /)

     Get the «inheritable» flag of the specified handle (a boolean).

     *note Availability: 2128.: Windows.

 -- Funzione: os.set_handle_inheritable (handle, inheritable, /)

     Set the «inheritable» flag of the specified handle.

     *note Availability: 2128.: Windows.


File: python.info,  Node: Files and Directories,  Next: Process Management,  Prev: File Descriptor Operations,  Up: os — Miscellaneous operating system interfaces

5.16.1.8 Files and Directories
..............................

On some Unix platforms, many of these functions support one or more of
these features:

   * 'specifying a file descriptor:' Normally the 'path' argument
     provided to functions in the *note os: a5. module must be a string
     specifying a file path.  However, some functions now alternatively
     accept an open file descriptor for their 'path' argument.  The
     function will then operate on the file referred to by the
     descriptor.  For POSIX systems, Python will call the variant of the
     function prefixed with ‘f’ (e.g.  call ‘fchdir’ instead of
     ‘chdir’).

     You can check whether or not 'path' can be specified as a file
     descriptor for a particular function on your platform using *note
     os.supports_fd: 1305.  If this functionality is unavailable, using
     it will raise a *note NotImplementedError: 36b.

     If the function also supports 'dir_fd' or 'follow_symlinks'
     arguments, it’s an error to specify one of those when supplying
     'path' as a file descriptor.

   * 'paths relative to directory descriptors:' If 'dir_fd' is not
     ‘None’, it should be a file descriptor referring to a directory,
     and the path to operate on should be relative; path will then be
     relative to that directory.  If the path is absolute, 'dir_fd' is
     ignored.  For POSIX systems, Python will call the variant of the
     function with an ‘at’ suffix and possibly prefixed with ‘f’ (e.g.
     call ‘faccessat’ instead of ‘access’).

     You can check whether or not 'dir_fd' is supported for a particular
     function on your platform using *note os.supports_dir_fd: 12ff.  If
     it’s unavailable, using it will raise a *note NotImplementedError:
     36b.

   * 'not following symlinks:' If 'follow_symlinks' is ‘False’, and the
     last element of the path to operate on is a symbolic link, the
     function will operate on the symbolic link itself rather than the
     file pointed to by the link.  For POSIX systems, Python will call
     the ‘l...’ variant of the function.

     You can check whether or not 'follow_symlinks' is supported for a
     particular function on your platform using *note
     os.supports_follow_symlinks: 1300.  If it’s unavailable, using it
     will raise a *note NotImplementedError: 36b.

 -- Funzione: os.access (path, mode, *, dir_fd=None,
          effective_ids=False, follow_symlinks=True)

     Use the real uid/gid to test for access to 'path'.  Note that most
     operations will use the effective uid/gid, therefore this routine
     can be used in a suid/sgid environment to test if the invoking user
     has the specified access to 'path'.  'mode' should be *note F_OK:
     305a. to test the existence of 'path', or it can be the inclusive
     OR of one or more of *note R_OK: 305b, *note W_OK: 305c, and *note
     X_OK: 305d. to test permissions.  Return *note True: e09. if access
     is allowed, *note False: d2d. if not.  See the Unix man page
     ‘access(2)(1)’ for more information.

     This function can support specifying *note paths relative to
     directory descriptors: 12f2. and *note not following symlinks:
     12f3.

     If 'effective_ids' is ‘True’, *note access(): 12f4. will perform
     its access checks using the effective uid/gid instead of the real
     uid/gid.  'effective_ids' may not be supported on your platform;
     you can check whether or not it is available using *note
     os.supports_effective_ids: 1306.  If it is unavailable, using it
     will raise a *note NotImplementedError: 36b.

          Nota: Using *note access(): 12f4. to check if a user is
          authorized to e.g.  open a file before actually doing so using
          *note open(): 316. creates a security hole, because the user
          might exploit the short time interval between checking and
          opening the file to manipulate it.  It’s preferable to use
          *note EAFP: 305e. techniques.  For example:

               if os.access("myfile", os.R_OK):
                   with open("myfile") as fp:
                       return fp.read()
               return "some default data"

          is better written as:

               try:
                   fp = open("myfile")
               except PermissionError:
                   return "some default data"
               else:
                   with fp:
                       return fp.read()

          Nota: I/O operations may fail even when *note access(): 12f4.
          indicates that they would succeed, particularly for operations
          on network filesystems which may have permissions semantics
          beyond the usual POSIX permission-bit model.

     Cambiato nella versione 3.3: Added the 'dir_fd', 'effective_ids',
     and 'follow_symlinks' parameters.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Dati: os.F_OK
 -- Dati: os.R_OK
 -- Dati: os.W_OK
 -- Dati: os.X_OK

     Values to pass as the 'mode' parameter of *note access(): 12f4. to
     test the existence, readability, writability and executability of
     'path', respectively.

 -- Funzione: os.chdir (path)

     Change the current working directory to 'path'.

     This function can support *note specifying a file descriptor: d55.
     The descriptor must refer to an opened directory, not an open file.

     This function can raise *note OSError: 2c0. and subclasses such as
     *note FileNotFoundError: 264, *note PermissionError: f40, and *note
     NotADirectoryError: 125c.

     Raises an *note auditing event: 1c56. ‘os.chdir’ with argument
     ‘path’.

     Cambiato nella versione 3.3: Added support for specifying 'path' as
     a file descriptor on some platforms.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.chflags (path, flags, *, follow_symlinks=True)

     Set the flags of 'path' to the numeric 'flags'.  'flags' may take a
     combination (bitwise OR) of the following values (as defined in the
     *note stat: d6. module):

        * *note stat.UF_NODUMP: 2c6f.

        * *note stat.UF_IMMUTABLE: 2c70.

        * *note stat.UF_APPEND: 2c71.

        * *note stat.UF_OPAQUE: 2c72.

        * *note stat.UF_NOUNLINK: 2c73.

        * *note stat.UF_COMPRESSED: 2c74.

        * *note stat.UF_HIDDEN: 2c77.

        * *note stat.SF_ARCHIVED: 2c7b.

        * *note stat.SF_IMMUTABLE: 2c7c.

        * *note stat.SF_APPEND: 2c7d.

        * *note stat.SF_NOUNLINK: 2c7f.

        * *note stat.SF_SNAPSHOT: 2c80.

     This function can support *note not following symlinks: 12f3.

     Raises an *note auditing event: 1c56. ‘os.chflags’ with arguments
     ‘path’, ‘flags’.

     *note Availability: 2128.: Unix, not WASI.

     Cambiato nella versione 3.3: Added the 'follow_symlinks' parameter.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.chmod (path, mode, *, dir_fd=None,
          follow_symlinks=True)

     Change the mode of 'path' to the numeric 'mode'.  'mode' may take
     one of the following values (as defined in the *note stat: d6.
     module) or bitwise ORed combinations of them:

        * *note stat.S_ISUID: 2c5b.

        * *note stat.S_ISGID: 2c5c.

        * *note stat.S_ENFMT: 2c5e.

        * *note stat.S_ISVTX: 2c5f.

        * *note stat.S_IREAD: 2c6b.

        * *note stat.S_IWRITE: 2c6c.

        * *note stat.S_IEXEC: 2c6d.

        * *note stat.S_IRWXU: 2c60.

        * *note stat.S_IRUSR: 2c61.

        * *note stat.S_IWUSR: 2c62.

        * *note stat.S_IXUSR: 2c63.

        * *note stat.S_IRWXG: 2c64.

        * *note stat.S_IRGRP: 2c65.

        * *note stat.S_IWGRP: 2c66.

        * *note stat.S_IXGRP: 2c5d.

        * *note stat.S_IRWXO: 2c67.

        * *note stat.S_IROTH: 2c68.

        * *note stat.S_IWOTH: 2c69.

        * *note stat.S_IXOTH: 2c6a.

     This function can support *note specifying a file descriptor: d55,
     *note paths relative to directory descriptors: 12f2. and *note not
     following symlinks: 12f3.

          Nota: Although Windows supports *note chmod(): 52a, you can
          only set the file’s read-only flag with it (via the
          ‘stat.S_IWRITE’ and ‘stat.S_IREAD’ constants or a
          corresponding integer value).  All other bits are ignored.
          The default value of 'follow_symlinks' is ‘False’ on Windows.

          The function is limited on WASI, see *note WebAssembly
          platforms: 1b52. for more information.

     Raises an *note auditing event: 1c56. ‘os.chmod’ with arguments
     ‘path’, ‘mode’, ‘dir_fd’.

     Cambiato nella versione 3.3: Added support for specifying 'path' as
     an open file descriptor, and the 'dir_fd' and 'follow_symlinks'
     arguments.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.13: Added support for a file descriptor
     and the 'follow_symlinks' argument on Windows.

 -- Funzione: os.chown (path, uid, gid, *, dir_fd=None,
          follow_symlinks=True)

     Change the owner and group id of 'path' to the numeric 'uid' and
     'gid'.  To leave one of the ids unchanged, set it to -1.

     This function can support *note specifying a file descriptor: d55,
     *note paths relative to directory descriptors: 12f2. and *note not
     following symlinks: 12f3.

     See *note shutil.chown(): 549. for a higher-level function that
     accepts names in addition to numeric ids.

     Raises an *note auditing event: 1c56. ‘os.chown’ with arguments
     ‘path’, ‘uid’, ‘gid’, ‘dir_fd’.

     *note Availability: 2128.: Unix.

     The function is limited on WASI, see *note WebAssembly platforms:
     1b52. for more information.

     Cambiato nella versione 3.3: Added support for specifying 'path' as
     an open file descriptor, and the 'dir_fd' and 'follow_symlinks'
     arguments.

     Cambiato nella versione 3.6: Supports a *note path-like object:
     5a1.

 -- Funzione: os.chroot (path)

     Change the root directory of the current process to 'path'.

     *note Availability: 2128.: Unix, not WASI, not Android.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.fchdir (fd)

     Change the current working directory to the directory represented
     by the file descriptor 'fd'.  The descriptor must refer to an
     opened directory, not an open file.  As of Python 3.3, this is
     equivalent to ‘os.chdir(fd)’.

     Raises an *note auditing event: 1c56. ‘os.chdir’ with argument
     ‘path’.

     *note Availability: 2128.: Unix.

 -- Funzione: os.getcwd ()

     Return a string representing the current working directory.

 -- Funzione: os.getcwdb ()

     Return a bytestring representing the current working directory.

     Cambiato nella versione 3.8: The function now uses the UTF-8
     encoding on Windows, rather than the ANSI code page: see PEP 529(2)
     for the rationale.  The function is no longer deprecated on
     Windows.

 -- Funzione: os.lchflags (path, flags)

     Set the flags of 'path' to the numeric 'flags', like *note
     chflags(): 12f5, but do not follow symbolic links.  As of Python
     3.3, this is equivalent to ‘os.chflags(path, flags,
     follow_symlinks=False)’.

     Raises an *note auditing event: 1c56. ‘os.chflags’ with arguments
     ‘path’, ‘flags’.

     *note Availability: 2128.: Unix, not WASI.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.lchmod (path, mode)

     Change the mode of 'path' to the numeric 'mode'.  If path is a
     symlink, this affects the symlink rather than the target.  See the
     docs for *note chmod(): 52a. for possible values of 'mode'.  As of
     Python 3.3, this is equivalent to ‘os.chmod(path, mode,
     follow_symlinks=False)’.

     ‘lchmod()’ is not part of POSIX, but Unix implementations may have
     it if changing the mode of symbolic links is supported.

     Raises an *note auditing event: 1c56. ‘os.chmod’ with arguments
     ‘path’, ‘mode’, ‘dir_fd’.

     *note Availability: 2128.: Unix, Windows, not Linux, FreeBSD >=
     1.3, NetBSD >= 1.3, not OpenBSD

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.13: Added support on Windows.

 -- Funzione: os.lchown (path, uid, gid)

     Change the owner and group id of 'path' to the numeric 'uid' and
     'gid'.  This function will not follow symbolic links.  As of Python
     3.3, this is equivalent to ‘os.chown(path, uid, gid,
     follow_symlinks=False)’.

     Raises an *note auditing event: 1c56. ‘os.chown’ with arguments
     ‘path’, ‘uid’, ‘gid’, ‘dir_fd’.

     *note Availability: 2128.: Unix.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.link (src, dst, *, src_dir_fd=None, dst_dir_fd=None,
          follow_symlinks=True)

     Create a hard link pointing to 'src' named 'dst'.

     This function can support specifying 'src_dir_fd' and/or
     'dst_dir_fd' to supply *note paths relative to directory
     descriptors: 12f2, and *note not following symlinks: 12f3.  The
     default value of 'follow_symlinks' is ‘False’ on Windows.

     Raises an *note auditing event: 1c56. ‘os.link’ with arguments
     ‘src’, ‘dst’, ‘src_dir_fd’, ‘dst_dir_fd’.

     *note Availability: 2128.: Unix, Windows.

     Cambiato nella versione 3.2: Added Windows support.

     Cambiato nella versione 3.3: Added the 'src_dir_fd', 'dst_dir_fd',
     and 'follow_symlinks' parameters.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.
     for 'src' and 'dst'.

 -- Funzione: os.listdir (path='.')

     Return a list containing the names of the entries in the directory
     given by 'path'.  The list is in arbitrary order, and does not
     include the special entries ‘'.'’ and ‘'..'’ even if they are
     present in the directory.  If a file is removed from or added to
     the directory during the call of this function, whether a name for
     that file be included is unspecified.

     'path' may be a *note path-like object: 5a1.  If 'path' is of type
     ‘bytes’ (directly or indirectly through the *note PathLike: e4d.
     interface), the filenames returned will also be of type ‘bytes’; in
     all other circumstances, they will be of type ‘str’.

     This function can also support *note specifying a file descriptor:
     d55.; the file descriptor must refer to a directory.

     Raises an *note auditing event: 1c56. ‘os.listdir’ with argument
     ‘path’.

          Nota: To encode ‘str’ filenames to ‘bytes’, use *note
          fsencode(): e51.

     Vedi anche
     ..........

     The *note scandir(): c56. function returns directory entries along
     with file attribute information, giving better performance for many
     common use cases.

     Cambiato nella versione 3.2: The 'path' parameter became optional.

     Cambiato nella versione 3.3: Added support for specifying 'path' as
     an open file descriptor.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.listdrives ()

     Return a list containing the names of drives on a Windows system.

     A drive name typically looks like ‘'C:\\'’.  Not every drive name
     will be associated with a volume, and some may be inaccessible for
     a variety of reasons, including permissions, network connectivity
     or missing media.  This function does not test for access.

     May raise *note OSError: 2c0. if an error occurs collecting the
     drive names.

     Raises an *note auditing event: 1c56. ‘os.listdrives’ with no
     arguments.

     *note Availability: 2128.: Windows

     Added in version 3.12.

 -- Funzione: os.listmounts (volume)

     Return a list containing the mount points for a volume on a Windows
     system.

     'volume' must be represented as a GUID path, like those returned by
     *note os.listvolumes(): 6c7.  Volumes may be mounted in multiple
     locations or not at all.  In the latter case, the list will be
     empty.  Mount points that are not associated with a volume will not
     be returned by this function.

     The mount points return by this function will be absolute paths,
     and may be longer than the drive name.

     Raises *note OSError: 2c0. if the volume is not recognized or if an
     error occurs collecting the paths.

     Raises an *note auditing event: 1c56. ‘os.listmounts’ with argument
     ‘volume’.

     *note Availability: 2128.: Windows

     Added in version 3.12.

 -- Funzione: os.listvolumes ()

     Return a list containing the volumes in the system.

     Volumes are typically represented as a GUID path that looks like
     ‘\\?\Volume{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}\’.  Files can
     usually be accessed through a GUID path, permissions allowing.
     However, users are generally not familiar with them, and so the
     recommended use of this function is to retrieve mount points using
     *note os.listmounts(): 6c8.

     May raise *note OSError: 2c0. if an error occurs collecting the
     volumes.

     Raises an *note auditing event: 1c56. ‘os.listvolumes’ with no
     arguments.

     *note Availability: 2128.: Windows

     Added in version 3.12.

 -- Funzione: os.lstat (path, *, dir_fd=None)

     Perform the equivalent of an ‘lstat()’ system call on the given
     path.  Similar to *note stat(): 26d, but does not follow symbolic
     links.  Return a *note stat_result: 16c8. object.

     On platforms that do not support symbolic links, this is an alias
     for *note stat(): 26d.

     As of Python 3.3, this is equivalent to ‘os.stat(path,
     dir_fd=dir_fd, follow_symlinks=False)’.

     This function can also support *note paths relative to directory
     descriptors: 12f2.

     Vedi anche
     ..........

     The *note stat(): 26d. function.

     Cambiato nella versione 3.2: Added support for Windows 6.0 (Vista)
     symbolic links.

     Cambiato nella versione 3.3: Added the 'dir_fd' parameter.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.8: On Windows, now opens reparse points
     that represent another path (name surrogates), including symbolic
     links and directory junctions.  Other kinds of reparse points are
     resolved by the operating system as for *note stat(): 26d.

 -- Funzione: os.mkdir (path, mode=0o777, *, dir_fd=None)

     Create a directory named 'path' with numeric mode 'mode'.

     If the directory already exists, *note FileExistsError: 1222. is
     raised.  If a parent directory in the path does not exist, *note
     FileNotFoundError: 264. is raised.  On some systems, 'mode' is
     ignored.  Where it is used, the current umask value is first masked
     out.  If bits other than the last 9 (i.e.  the last 3 digits of the
     octal representation of the 'mode') are set, their meaning is
     platform-dependent.  On some platforms, they are ignored and you
     should call *note chmod(): 52a. explicitly to set them.

     On Windows, a 'mode' of ‘0o700’ is specifically handled to apply
     access control to the new directory such that only the current user
     and administrators have access.  Other values of 'mode' are
     ignored.

     This function can also support *note paths relative to directory
     descriptors: 12f2.

     It is also possible to create temporary directories; see the *note
     tempfile: e6. module’s *note tempfile.mkdtemp(): 52e. function.

     Raises an *note auditing event: 1c56. ‘os.mkdir’ with arguments
     ‘path’, ‘mode’, ‘dir_fd’.

     Cambiato nella versione 3.3: Added the 'dir_fd' parameter.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.13: Windows now handles a 'mode' of
     ‘0o700’.

 -- Funzione: os.makedirs (name, mode=0o777, exist_ok=False)

     Recursive directory creation function.  Like *note mkdir(): 52c,
     but makes all intermediate-level directories needed to contain the
     leaf directory.

     The 'mode' parameter is passed to *note mkdir(): 52c. for creating
     the leaf directory; see *note the mkdir() description: 3061. for
     how it is interpreted.  To set the file permission bits of any
     newly created parent directories you can set the umask before
     invoking *note makedirs(): 52d.  The file permission bits of
     existing parent directories are not changed.

     If 'exist_ok' is ‘False’ (the default), a *note FileExistsError:
     1222. is raised if the target directory already exists.

          Nota: *note makedirs(): 52d. will become confused if the path
          elements to create include *note pardir: 3062. (eg.  «..» on
          UNIX systems).

     This function handles UNC paths correctly.

     Raises an *note auditing event: 1c56. ‘os.mkdir’ with arguments
     ‘path’, ‘mode’, ‘dir_fd’.

     Cambiato nella versione 3.2: Added the 'exist_ok' parameter.

     Cambiato nella versione 3.4.1: Before Python 3.4.1, if 'exist_ok'
     was ‘True’ and the directory existed, *note makedirs(): 52d. would
     still raise an error if 'mode' did not match the mode of the
     existing directory.  Since this behavior was impossible to
     implement safely, it was removed in Python 3.4.1.  See
     bpo-21082(3).

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.7: The 'mode' argument no longer affects
     the file permission bits of newly created intermediate-level
     directories.

 -- Funzione: os.mkfifo (path, mode=0o666, *, dir_fd=None)

     Create a FIFO (a named pipe) named 'path' with numeric mode 'mode'.
     The current umask value is first masked out from the mode.

     This function can also support *note paths relative to directory
     descriptors: 12f2.

     FIFOs are pipes that can be accessed like regular files.  FIFOs
     exist until they are deleted (for example with *note os.unlink():
     12fd.).  Generally, FIFOs are used as rendezvous between «client»
     and «server» type processes: the server opens the FIFO for reading,
     and the client opens it for writing.  Note that *note mkfifo():
     f92. doesn’t open the FIFO — it just creates the rendezvous point.

     *note Availability: 2128.: Unix, not WASI.

     Cambiato nella versione 3.3: Added the 'dir_fd' parameter.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.mknod (path, mode=0o600, device=0, *, dir_fd=None)

     Create a filesystem node (file, device special file or named pipe)
     named 'path'.  'mode' specifies both the permissions to use and the
     type of node to be created, being combined (bitwise OR) with one of
     ‘stat.S_IFREG’, ‘stat.S_IFCHR’, ‘stat.S_IFBLK’, and ‘stat.S_IFIFO’
     (those constants are available in *note stat: d6.).  For
     ‘stat.S_IFCHR’ and ‘stat.S_IFBLK’, 'device' defines the newly
     created device special file (probably using *note os.makedev():
     1948.), otherwise it is ignored.

     This function can also support *note paths relative to directory
     descriptors: 12f2.

     *note Availability: 2128.: Unix, not WASI.

     Cambiato nella versione 3.3: Added the 'dir_fd' parameter.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.major (device, /)

     Extract the device major number from a raw device number (usually
     the ‘st_dev’ or ‘st_rdev’ field from ‘stat’).

 -- Funzione: os.minor (device, /)

     Extract the device minor number from a raw device number (usually
     the ‘st_dev’ or ‘st_rdev’ field from ‘stat’).

 -- Funzione: os.makedev (major, minor, /)

     Compose a raw device number from the major and minor device
     numbers.

 -- Funzione: os.pathconf (path, name)

     Return system configuration information relevant to a named file.
     'name' specifies the configuration value to retrieve; it may be a
     string which is the name of a defined system value; these names are
     specified in a number of standards (POSIX.1, Unix 95, Unix 98, and
     others).  Some platforms define additional names as well.  The
     names known to the host operating system are given in the
     ‘pathconf_names’ dictionary.  For configuration variables not
     included in that mapping, passing an integer for 'name' is also
     accepted.

     If 'name' is a string and is not known, *note ValueError: 2ec. is
     raised.  If a specific value for 'name' is not supported by the
     host system, even if it is included in ‘pathconf_names’, an *note
     OSError: 2c0. is raised with *note errno.EINVAL: 1dba. for the
     error number.

     This function can support *note specifying a file descriptor: d55.

     *note Availability: 2128.: Unix.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Dati: os.pathconf_names

     Dictionary mapping names accepted by *note pathconf(): 1303. and
     *note fpathconf(): 3020. to the integer values defined for those
     names by the host operating system.  This can be used to determine
     the set of names known to the system.

     *note Availability: 2128.: Unix.

 -- Funzione: os.readlink (path, *, dir_fd=None)

     Return a string representing the path to which the symbolic link
     points.  The result may be either an absolute or relative pathname;
     if it is relative, it may be converted to an absolute pathname
     using ‘os.path.join(os.path.dirname(path), result)’.

     If the 'path' is a string object (directly or indirectly through a
     *note PathLike: e4d. interface), the result will also be a string
     object, and the call may raise a UnicodeDecodeError.  If the 'path'
     is a bytes object (direct or indirectly), the result will be a
     bytes object.

     This function can also support *note paths relative to directory
     descriptors: 12f2.

     When trying to resolve a path that may contain links, use *note
     realpath(): 262. to properly handle recursion and platform
     differences.

     *note Availability: 2128.: Unix, Windows.

     Cambiato nella versione 3.2: Added support for Windows 6.0 (Vista)
     symbolic links.

     Cambiato nella versione 3.3: Added the 'dir_fd' parameter.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.
     on Unix.

     Cambiato nella versione 3.8: Accepts a *note path-like object: 5a1.
     and a bytes object on Windows.

     Added support for directory junctions, and changed to return the
     substitution path (which typically includes ‘\\?\’ prefix) rather
     than the optional «print name» field that was previously returned.

 -- Funzione: os.remove (path, *, dir_fd=None)

     Remove (delete) the file 'path'.  If 'path' is a directory, an
     *note OSError: 2c0. is raised.  Use *note rmdir(): 12fb. to remove
     directories.  If the file does not exist, a *note
     FileNotFoundError: 264. is raised.

     This function can support *note paths relative to directory
     descriptors: 12f2.

     On Windows, attempting to remove a file that is in use causes an
     exception to be raised; on Unix, the directory entry is removed but
     the storage allocated to the file is not made available until the
     original file is no longer in use.

     This function is semantically identical to *note unlink(): 12fd.

     Raises an *note auditing event: 1c56. ‘os.remove’ with arguments
     ‘path’, ‘dir_fd’.

     Cambiato nella versione 3.3: Added the 'dir_fd' parameter.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.removedirs (name)

     Remove directories recursively.  Works like *note rmdir(): 12fb.
     except that, if the leaf directory is successfully removed, *note
     removedirs(): 3064. tries to successively remove every parent
     directory mentioned in 'path' until an error is raised (which is
     ignored, because it generally means that a parent directory is not
     empty).  For example, ‘os.removedirs('foo/bar/baz')’ will first
     remove the directory ‘'foo/bar/baz'’, and then remove ‘'foo/bar'’
     and ‘'foo'’ if they are empty.  Raises *note OSError: 2c0. if the
     leaf directory could not be successfully removed.

     Raises an *note auditing event: 1c56. ‘os.remove’ with arguments
     ‘path’, ‘dir_fd’.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.rename (src, dst, *, src_dir_fd=None, dst_dir_fd=None)

     Rename the file or directory 'src' to 'dst'.  If 'dst' exists, the
     operation will fail with an *note OSError: 2c0. subclass in a
     number of cases:

     On Windows, if 'dst' exists a *note FileExistsError: 1222. is
     always raised.  The operation may fail if 'src' and 'dst' are on
     different filesystems.  Use *note shutil.move(): c53. to support
     moves to a different filesystem.

     On Unix, if 'src' is a file and 'dst' is a directory or vice-versa,
     an *note IsADirectoryError: 125b. or a *note NotADirectoryError:
     125c. will be raised respectively.  If both are directories and
     'dst' is empty, 'dst' will be silently replaced.  If 'dst' is a
     non-empty directory, an *note OSError: 2c0. is raised.  If both are
     files, 'dst' will be replaced silently if the user has permission.
     The operation may fail on some Unix flavors if 'src' and 'dst' are
     on different filesystems.  If successful, the renaming will be an
     atomic operation (this is a POSIX requirement).

     This function can support specifying 'src_dir_fd' and/or
     'dst_dir_fd' to supply *note paths relative to directory
     descriptors: 12f2.

     If you want cross-platform overwriting of the destination, use
     *note replace(): 12fa.

     Raises an *note auditing event: 1c56. ‘os.rename’ with arguments
     ‘src’, ‘dst’, ‘src_dir_fd’, ‘dst_dir_fd’.

     Cambiato nella versione 3.3: Added the 'src_dir_fd' and
     'dst_dir_fd' parameters.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.
     for 'src' and 'dst'.

 -- Funzione: os.renames (old, new)

     Recursive directory or file renaming function.  Works like *note
     rename(): 12f9, except creation of any intermediate directories
     needed to make the new pathname good is attempted first.  After the
     rename, directories corresponding to rightmost path segments of the
     old name will be pruned away using *note removedirs(): 3064.

          Nota: This function can fail with the new directory structure
          made if you lack permissions needed to remove the leaf
          directory or file.

     Raises an *note auditing event: 1c56. ‘os.rename’ with arguments
     ‘src’, ‘dst’, ‘src_dir_fd’, ‘dst_dir_fd’.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.
     for 'old' and 'new'.

 -- Funzione: os.replace (src, dst, *, src_dir_fd=None, dst_dir_fd=None)

     Rename the file or directory 'src' to 'dst'.  If 'dst' is a
     non-empty directory, *note OSError: 2c0. will be raised.  If 'dst'
     exists and is a file, it will be replaced silently if the user has
     permission.  The operation may fail if 'src' and 'dst' are on
     different filesystems.  If successful, the renaming will be an
     atomic operation (this is a POSIX requirement).

     This function can support specifying 'src_dir_fd' and/or
     'dst_dir_fd' to supply *note paths relative to directory
     descriptors: 12f2.

     Raises an *note auditing event: 1c56. ‘os.rename’ with arguments
     ‘src’, ‘dst’, ‘src_dir_fd’, ‘dst_dir_fd’.

     Added in version 3.3.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.
     for 'src' and 'dst'.

 -- Funzione: os.rmdir (path, *, dir_fd=None)

     Remove (delete) the directory 'path'.  If the directory does not
     exist or is not empty, a *note FileNotFoundError: 264. or an *note
     OSError: 2c0. is raised respectively.  In order to remove whole
     directory trees, *note shutil.rmtree(): 356. can be used.

     This function can support *note paths relative to directory
     descriptors: 12f2.

     Raises an *note auditing event: 1c56. ‘os.rmdir’ with arguments
     ‘path’, ‘dir_fd’.

     Cambiato nella versione 3.3: Added the 'dir_fd' parameter.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.scandir (path='.')

     Return an iterator of *note os.DirEntry: 6c4. objects corresponding
     to the entries in the directory given by 'path'.  The entries are
     yielded in arbitrary order, and the special entries ‘'.'’ and
     ‘'..'’ are not included.  If a file is removed from or added to the
     directory after creating the iterator, whether an entry for that
     file be included is unspecified.

     Using *note scandir(): c56. instead of *note listdir(): 1302. can
     significantly increase the performance of code that also needs file
     type or file attribute information, because *note os.DirEntry: 6c4.
     objects expose this information if the operating system provides it
     when scanning a directory.  All *note os.DirEntry: 6c4. methods may
     perform a system call, but *note is_dir(): 3066. and *note
     is_file(): f86. usually only require a system call for symbolic
     links; *note os.DirEntry.stat(): 1a53. always requires a system
     call on Unix but only requires one for symbolic links on Windows.

     'path' may be a *note path-like object: 5a1.  If 'path' is of type
     ‘bytes’ (directly or indirectly through the *note PathLike: e4d.
     interface), the type of the *note name: 3067. and *note path: 19e0.
     attributes of each *note os.DirEntry: 6c4. will be ‘bytes’; in all
     other circumstances, they will be of type ‘str’.

     This function can also support *note specifying a file descriptor:
     d55.; the file descriptor must refer to a directory.

     Raises an *note auditing event: 1c56. ‘os.scandir’ with argument
     ‘path’.

     The *note scandir(): c56. iterator supports the *note context
     manager: 1e1. protocol and has the following method:

      -- Metodo: scandir.close ()

          Close the iterator and free acquired resources.

          This is called automatically when the iterator is exhausted or
          garbage collected, or when an error happens during iterating.
          However it is advisable to call it explicitly or use the *note
          with: 186. statement.

          Added in version 3.6.

     The following example shows a simple use of *note scandir(): c56.
     to display all the files (excluding directories) in the given
     'path' that don’t start with ‘'.'’.  The ‘entry.is_file()’ call
     will generally not make an additional system call:

          with os.scandir(path) as it:
              for entry in it:
                  if not entry.name.startswith('.') and entry.is_file():
                      print(entry.name)

          Nota: On Unix-based systems, *note scandir(): c56. uses the
          system’s opendir()(4) and readdir()(5) functions.  On Windows,
          it uses the Win32 FindFirstFileW(6) and FindNextFileW(7)
          functions.

     Added in version 3.5.

     Cambiato nella versione 3.6: Added support for the *note context
     manager: 1e1. protocol and the *note close(): eba. method.  If a
     *note scandir(): c56. iterator is neither exhausted nor explicitly
     closed a *note ResourceWarning: 54d. will be emitted in its
     destructor.

     The function accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.7: Added support for *note file
     descriptors: d55. on Unix.

 -- Classe: os.DirEntry

     Object yielded by *note scandir(): c56. to expose the file path and
     other file attributes of a directory entry.

     *note scandir(): c56. will provide as much of this information as
     possible without making additional system calls.  When a ‘stat()’
     or ‘lstat()’ system call is made, the ‘os.DirEntry’ object will
     cache the result.

     ‘os.DirEntry’ instances are not intended to be stored in long-lived
     data structures; if you know the file metadata has changed or if a
     long time has elapsed since calling *note scandir(): c56, call
     ‘os.stat(entry.path)’ to fetch up-to-date information.

     Because the ‘os.DirEntry’ methods can make operating system calls,
     they may also raise *note OSError: 2c0.  If you need very
     fine-grained control over errors, you can catch *note OSError: 2c0.
     when calling one of the ‘os.DirEntry’ methods and handle as
     appropriate.

     To be directly usable as a *note path-like object: 5a1,
     ‘os.DirEntry’ implements the *note PathLike: e4d. interface.

     Attributes and methods on a ‘os.DirEntry’ instance are as follows:

      -- Attributo: name

          The entry’s base filename, relative to the *note scandir():
          c56. 'path' argument.

          The *note name: 2fe8. attribute will be ‘bytes’ if the *note
          scandir(): c56. 'path' argument is of type ‘bytes’ and ‘str’
          otherwise.  Use *note fsdecode(): e50. to decode byte
          filenames.

      -- Attributo: path

          The entry’s full path name: equivalent to
          ‘os.path.join(scandir_path, entry.name)’ where 'scandir_path'
          is the *note scandir(): c56. 'path' argument.  The path is
          only absolute if the *note scandir(): c56. 'path' argument was
          absolute.  If the *note scandir(): c56. 'path' argument was a
          *note file descriptor: d55, the *note path: a6. attribute is
          the same as the *note name: 2fe8. attribute.

          The *note path: a6. attribute will be ‘bytes’ if the *note
          scandir(): c56. 'path' argument is of type ‘bytes’ and ‘str’
          otherwise.  Use *note fsdecode(): e50. to decode byte
          filenames.

      -- Metodo: inode ()

          Return the inode number of the entry.

          The result is cached on the ‘os.DirEntry’ object.  Use
          ‘os.stat(entry.path, follow_symlinks=False).st_ino’ to fetch
          up-to-date information.

          On the first, uncached call, a system call is required on
          Windows but not on Unix.

      -- Metodo: is_dir (*, follow_symlinks=True)

          Return ‘True’ if this entry is a directory or a symbolic link
          pointing to a directory; return ‘False’ if the entry is or
          points to any other kind of file, or if it doesn’t exist
          anymore.

          If 'follow_symlinks' is ‘False’, return ‘True’ only if this
          entry is a directory (without following symlinks); return
          ‘False’ if the entry is any other kind of file or if it
          doesn’t exist anymore.

          The result is cached on the ‘os.DirEntry’ object, with a
          separate cache for 'follow_symlinks' ‘True’ and ‘False’.  Call
          *note os.stat(): 26d. along with *note stat.S_ISDIR(): 2c42.
          to fetch up-to-date information.

          On the first, uncached call, no system call is required in
          most cases.  Specifically, for non-symlinks, neither Windows
          or Unix require a system call, except on certain Unix file
          systems, such as network file systems, that return
          ‘dirent.d_type == DT_UNKNOWN’.  If the entry is a symlink, a
          system call will be required to follow the symlink unless
          'follow_symlinks' is ‘False’.

          This method can raise *note OSError: 2c0, such as *note
          PermissionError: f40, but *note FileNotFoundError: 264. is
          caught and not raised.

      -- Metodo: is_file (*, follow_symlinks=True)

          Return ‘True’ if this entry is a file or a symbolic link
          pointing to a file; return ‘False’ if the entry is or points
          to a directory or other non-file entry, or if it doesn’t exist
          anymore.

          If 'follow_symlinks' is ‘False’, return ‘True’ only if this
          entry is a file (without following symlinks); return ‘False’
          if the entry is a directory or other non-file entry, or if it
          doesn’t exist anymore.

          The result is cached on the ‘os.DirEntry’ object.  Caching,
          system calls made, and exceptions raised are as per *note
          is_dir(): 3066.

      -- Metodo: is_symlink ()

          Return ‘True’ if this entry is a symbolic link (even if
          broken); return ‘False’ if the entry points to a directory or
          any kind of file, or if it doesn’t exist anymore.

          The result is cached on the ‘os.DirEntry’ object.  Call *note
          os.path.islink(): c03. to fetch up-to-date information.

          On the first, uncached call, no system call is required in
          most cases.  Specifically, neither Windows or Unix require a
          system call, except on certain Unix file systems, such as
          network file systems, that return ‘dirent.d_type ==
          DT_UNKNOWN’.

          This method can raise *note OSError: 2c0, such as *note
          PermissionError: f40, but *note FileNotFoundError: 264. is
          caught and not raised.

      -- Metodo: is_junction ()

          Return ‘True’ if this entry is a junction (even if broken);
          return ‘False’ if the entry points to a regular directory, any
          kind of file, a symlink, or if it doesn’t exist anymore.

          The result is cached on the ‘os.DirEntry’ object.  Call *note
          os.path.isjunction(): 6cb. to fetch up-to-date information.

          Added in version 3.12.

      -- Metodo: stat (*, follow_symlinks=True)

          Return a *note stat_result: 16c8. object for this entry.  This
          method follows symbolic links by default; to stat a symbolic
          link add the ‘follow_symlinks=False’ argument.

          On Unix, this method always requires a system call.  On
          Windows, it only requires a system call if 'follow_symlinks'
          is ‘True’ and the entry is a reparse point (for example, a
          symbolic link or directory junction).

          On Windows, the ‘st_ino’, ‘st_dev’ and ‘st_nlink’ attributes
          of the *note stat_result: 16c8. are always set to zero.  Call
          *note os.stat(): 26d. to get these attributes.

          The result is cached on the ‘os.DirEntry’ object, with a
          separate cache for 'follow_symlinks' ‘True’ and ‘False’.  Call
          *note os.stat(): 26d. to fetch up-to-date information.

     Note that there is a nice correspondence between several attributes
     and methods of ‘os.DirEntry’ and of *note pathlib.Path: 266.  In
     particular, the ‘name’ attribute has the same meaning, as do the
     ‘is_dir()’, ‘is_file()’, ‘is_symlink()’, ‘is_junction()’, and
     ‘stat()’ methods.

     Added in version 3.5.

     Cambiato nella versione 3.6: Added support for the *note PathLike:
     e4d. interface.  Added support for *note bytes: 192. paths on
     Windows.

     Cambiato nella versione 3.12: The ‘st_ctime’ attribute of a stat
     result is deprecated on Windows.  The file creation time is
     properly available as ‘st_birthtime’, and in the future ‘st_ctime’
     may be changed to return zero or the metadata change time, if
     available.

 -- Funzione: os.stat (path, *, dir_fd=None, follow_symlinks=True)

     Get the status of a file or a file descriptor.  Perform the
     equivalent of a ‘stat()’ system call on the given path.  'path' may
     be specified as either a string or bytes – directly or indirectly
     through the *note PathLike: e4d. interface – or as an open file
     descriptor.  Return a *note stat_result: 16c8. object.

     This function normally follows symlinks; to stat a symlink add the
     argument ‘follow_symlinks=False’, or use *note lstat(): 6c9.

     This function can support *note specifying a file descriptor: d55.
     and *note not following symlinks: 12f3.

     On Windows, passing ‘follow_symlinks=False’ will disable following
     all name-surrogate reparse points, which includes symlinks and
     directory junctions.  Other types of reparse points that do not
     resemble links or that the operating system is unable to follow
     will be opened directly.  When following a chain of multiple links,
     this may result in the original link being returned instead of the
     non-link that prevented full traversal.  To obtain stat results for
     the final path in this case, use the *note os.path.realpath(): 262.
     function to resolve the path name as far as possible and call *note
     lstat(): 6c9. on the result.  This does not apply to dangling
     symlinks or junction points, which will raise the usual exceptions.

     Example:

          >>> import os
          >>> statinfo = os.stat('somefile.txt')
          >>> statinfo
          os.stat_result(st_mode=33188, st_ino=7876932, st_dev=234881026,
          st_nlink=1, st_uid=501, st_gid=501, st_size=264, st_atime=1297230295,
          st_mtime=1297230027, st_ctime=1297230027)
          >>> statinfo.st_size
          264

     Vedi anche
     ..........

     *note fstat(): f8e. and *note lstat(): 6c9. functions.

     Cambiato nella versione 3.3: Added the 'dir_fd' and
     'follow_symlinks' parameters, specifying a file descriptor instead
     of a path.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.8: On Windows, all reparse points that
     can be resolved by the operating system are now followed, and
     passing ‘follow_symlinks=False’ disables following all name
     surrogate reparse points.  If the operating system reaches a
     reparse point that it is not able to follow, 'stat' now returns the
     information for the original path as if ‘follow_symlinks=False’ had
     been specified instead of raising an error.

 -- Classe: os.stat_result

     Object whose attributes correspond roughly to the members of the
     ‘stat’ structure.  It is used for the result of *note os.stat():
     26d, *note os.fstat(): f8e. and *note os.lstat(): 6c9.

     Attributes:

      -- Attributo: st_mode

          File mode: file type and file mode bits (permissions).

      -- Attributo: st_ino

          Platform dependent, but if non-zero, uniquely identifies the
          file for a given value of ‘st_dev’.  Typically:

             * the inode number on Unix,

             * the file index(8) on Windows

      -- Attributo: st_dev

          Identifier of the device on which this file resides.

      -- Attributo: st_nlink

          Number of hard links.

      -- Attributo: st_uid

          User identifier of the file owner.

      -- Attributo: st_gid

          Group identifier of the file owner.

      -- Attributo: st_size

          Size of the file in bytes, if it is a regular file or a
          symbolic link.  The size of a symbolic link is the length of
          the pathname it contains, without a terminating null byte.

     Timestamps:

      -- Attributo: st_atime

          Time of most recent access expressed in seconds.

      -- Attributo: st_mtime

          Time of most recent content modification expressed in seconds.

      -- Attributo: st_ctime

          Time of most recent metadata change expressed in seconds.

          Cambiato nella versione 3.12: ‘st_ctime’ is deprecated on
          Windows.  Use ‘st_birthtime’ for the file creation time.  In
          the future, ‘st_ctime’ will contain the time of the most
          recent metadata change, as for other platforms.

      -- Attributo: st_atime_ns

          Time of most recent access expressed in nanoseconds as an
          integer.

          Added in version 3.3.

      -- Attributo: st_mtime_ns

          Time of most recent content modification expressed in
          nanoseconds as an integer.

          Added in version 3.3.

      -- Attributo: st_ctime_ns

          Time of most recent metadata change expressed in nanoseconds
          as an integer.

          Added in version 3.3.

          Cambiato nella versione 3.12: ‘st_ctime_ns’ is deprecated on
          Windows.  Use ‘st_birthtime_ns’ for the file creation time.
          In the future, ‘st_ctime’ will contain the time of the most
          recent metadata change, as for other platforms.

      -- Attributo: st_birthtime

          Time of file creation expressed in seconds.  This attribute is
          not always available, and may raise *note AttributeError: 5f0.

          Cambiato nella versione 3.12: ‘st_birthtime’ is now available
          on Windows.

      -- Attributo: st_birthtime_ns

          Time of file creation expressed in nanoseconds as an integer.
          This attribute is not always available, and may raise *note
          AttributeError: 5f0.

          Added in version 3.12.

          Nota: The exact meaning and resolution of the *note st_atime:
          306f, *note st_mtime: 2efa, *note st_ctime: 3070. and *note
          st_birthtime: 3074. attributes depend on the operating system
          and the file system.  For example, on Windows systems using
          the FAT32 file systems, *note st_mtime: 2efa. has 2-second
          resolution, and *note st_atime: 306f. has only 1-day
          resolution.  See your operating system documentation for
          details.

          Similarly, although *note st_atime_ns: 3071, *note
          st_mtime_ns: 3072, *note st_ctime_ns: 3073. and *note
          st_birthtime_ns: 3075. are always expressed in nanoseconds,
          many systems do not provide nanosecond precision.  On systems
          that do provide nanosecond precision, the floating-point
          object used to store *note st_atime: 306f, *note st_mtime:
          2efa, *note st_ctime: 3070. and *note st_birthtime: 3074.
          cannot preserve all of it, and as such will be slightly
          inexact.  If you need the exact timestamps you should always
          use *note st_atime_ns: 3071, *note st_mtime_ns: 3072, *note
          st_ctime_ns: 3073. and *note st_birthtime_ns: 3075.

     On some Unix systems (such as Linux), the following attributes may
     also be available:

      -- Attributo: st_blocks

          Number of 512-byte blocks allocated for file.  This may be
          smaller than *note st_size: 306e./512 when the file has holes.

      -- Attributo: st_blksize

          «Preferred» blocksize for efficient file system I/O. Writing
          to a file in smaller chunks may cause an inefficient
          read-modify-rewrite.

      -- Attributo: st_rdev

          Type of device if an inode device.

      -- Attributo: st_flags

          User defined flags for file.

     On other Unix systems (such as FreeBSD), the following attributes
     may be available (but may be only filled out if root tries to use
     them):

      -- Attributo: st_gen

          File generation number.

     On Solaris and derivatives, the following attributes may also be
     available:

      -- Attributo: st_fstype

          String that uniquely identifies the type of the filesystem
          that contains the file.

     On macOS systems, the following attributes may also be available:

      -- Attributo: st_rsize

          Real size of the file.

      -- Attributo: st_creator

          Creator of the file.

      -- Attributo: st_type

          File type.

     On Windows systems, the following attributes are also available:

      -- Attributo: st_file_attributes

          Windows file attributes: ‘dwFileAttributes’ member of the
          ‘BY_HANDLE_FILE_INFORMATION’ structure returned by
          ‘GetFileInformationByHandle()’.  See the ‘FILE_ATTRIBUTE_*
          <stat.FILE_ATTRIBUTE_ARCHIVE>’ constants in the *note stat:
          d6. module.

          Added in version 3.5.

      -- Attributo: st_reparse_tag

          When *note st_file_attributes: 103a. has the *note
          FILE_ATTRIBUTE_REPARSE_POINT: 2c8f. set, this field contains
          the tag identifying the type of reparse point.  See the *note
          IO_REPARSE_TAG_*: 2c94. constants in the *note stat: d6.
          module.

     The standard module *note stat: d6. defines functions and constants
     that are useful for extracting information from a ‘stat’ structure.
     (On Windows, some items are filled with dummy values.)

     For backward compatibility, a *note stat_result: 16c8. instance is
     also accessible as a tuple of at least 10 integers giving the most
     important (and portable) members of the ‘stat’ structure, in the
     order *note st_mode: c01, *note st_ino: 3069, *note st_dev: 306a,
     *note st_nlink: 306b, *note st_uid: 306c, *note st_gid: 306d, *note
     st_size: 306e, *note st_atime: 306f, *note st_mtime: 2efa, *note
     st_ctime: 3070.  More items may be added at the end by some
     implementations.  For compatibility with older Python versions,
     accessing *note stat_result: 16c8. as a tuple always returns
     integers.

     Cambiato nella versione 3.5: Windows now returns the file index as
     *note st_ino: 3069. when available.

     Cambiato nella versione 3.7: Added the *note st_fstype: d5d. member
     to Solaris/derivatives.

     Cambiato nella versione 3.8: Added the *note st_reparse_tag: c02.
     member on Windows.

     Cambiato nella versione 3.8: On Windows, the *note st_mode: c01.
     member now identifies special files as ‘S_IFCHR’, ‘S_IFIFO’ or
     ‘S_IFBLK’ as appropriate.

     Cambiato nella versione 3.12: On Windows, *note st_ctime: 3070. is
     deprecated.  Eventually, it will contain the last metadata change
     time, for consistency with other platforms, but for now still
     contains creation time.  Use *note st_birthtime: 3074. for the
     creation time.

     On Windows, *note st_ino: 3069. may now be up to 128 bits,
     depending on the file system.  Previously it would not be above 64
     bits, and larger file identifiers would be arbitrarily packed.

     On Windows, *note st_rdev: 17a7. no longer returns a value.
     Previously it would contain the same as *note st_dev: 306a, which
     was incorrect.

     Added the *note st_birthtime: 3074. member on Windows.

 -- Funzione: os.statvfs (path)

     Perform a ‘statvfs()’ system call on the given path.  The return
     value is an object whose attributes describe the filesystem on the
     given path, and correspond to the members of the ‘statvfs’
     structure, namely: ‘f_bsize’, ‘f_frsize’, ‘f_blocks’, ‘f_bfree’,
     ‘f_bavail’, ‘f_files’, ‘f_ffree’, ‘f_favail’, ‘f_flag’,
     ‘f_namemax’, ‘f_fsid’.

     Two module-level constants are defined for the ‘f_flag’ attribute’s
     bit-flags: if ‘ST_RDONLY’ is set, the filesystem is mounted
     read-only, and if ‘ST_NOSUID’ is set, the semantics of
     setuid/setgid bits are disabled or not supported.

     Additional module-level constants are defined for GNU/glibc based
     systems.  These are ‘ST_NODEV’ (disallow access to device special
     files), ‘ST_NOEXEC’ (disallow program execution), ‘ST_SYNCHRONOUS’
     (writes are synced at once), ‘ST_MANDLOCK’ (allow mandatory locks
     on an FS), ‘ST_WRITE’ (write on file/directory/symlink),
     ‘ST_APPEND’ (append-only file), ‘ST_IMMUTABLE’ (immutable file),
     ‘ST_NOATIME’ (do not update access times), ‘ST_NODIRATIME’ (do not
     update directory access times), ‘ST_RELATIME’ (update atime
     relative to mtime/ctime).

     This function can support *note specifying a file descriptor: d55.

     *note Availability: 2128.: Unix.

     Cambiato nella versione 3.2: The ‘ST_RDONLY’ and ‘ST_NOSUID’
     constants were added.

     Cambiato nella versione 3.3: Added support for specifying 'path' as
     an open file descriptor.

     Cambiato nella versione 3.4: The ‘ST_NODEV’, ‘ST_NOEXEC’,
     ‘ST_SYNCHRONOUS’, ‘ST_MANDLOCK’, ‘ST_WRITE’, ‘ST_APPEND’,
     ‘ST_IMMUTABLE’, ‘ST_NOATIME’, ‘ST_NODIRATIME’, and ‘ST_RELATIME’
     constants were added.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.7: Added the ‘f_fsid’ attribute.

 -- Dati: os.supports_dir_fd

     A *note set: 184. object indicating which functions in the *note
     os: a5. module accept an open file descriptor for their 'dir_fd'
     parameter.  Different platforms provide different features, and the
     underlying functionality Python uses to implement the 'dir_fd'
     parameter is not available on all platforms Python supports.  For
     consistency’s sake, functions that may support 'dir_fd' always
     allow specifying the parameter, but will throw an exception if the
     functionality is used when it’s not locally available.  (Specifying
     ‘None’ for 'dir_fd' is always supported on all platforms.)

     To check whether a particular function accepts an open file
     descriptor for its 'dir_fd' parameter, use the ‘in’ operator on
     ‘supports_dir_fd’.  As an example, this expression evaluates to
     ‘True’ if *note os.stat(): 26d. accepts open file descriptors for
     'dir_fd' on the local platform:

          os.stat in os.supports_dir_fd

     Currently 'dir_fd' parameters only work on Unix platforms; none of
     them work on Windows.

     Added in version 3.3.

 -- Dati: os.supports_effective_ids

     A *note set: 184. object indicating whether *note os.access():
     12f4. permits specifying ‘True’ for its 'effective_ids' parameter
     on the local platform.  (Specifying ‘False’ for 'effective_ids' is
     always supported on all platforms.)  If the local platform supports
     it, the collection will contain *note os.access(): 12f4.; otherwise
     it will be empty.

     This expression evaluates to ‘True’ if *note os.access(): 12f4.
     supports ‘effective_ids=True’ on the local platform:

          os.access in os.supports_effective_ids

     Currently 'effective_ids' is only supported on Unix platforms; it
     does not work on Windows.

     Added in version 3.3.

 -- Dati: os.supports_fd

     A *note set: 184. object indicating which functions in the *note
     os: a5. module permit specifying their 'path' parameter as an open
     file descriptor on the local platform.  Different platforms provide
     different features, and the underlying functionality Python uses to
     accept open file descriptors as 'path' arguments is not available
     on all platforms Python supports.

     To determine whether a particular function permits specifying an
     open file descriptor for its 'path' parameter, use the ‘in’
     operator on ‘supports_fd’.  As an example, this expression
     evaluates to ‘True’ if *note os.chdir(): 822. accepts open file
     descriptors for 'path' on your local platform:

          os.chdir in os.supports_fd

     Added in version 3.3.

 -- Dati: os.supports_follow_symlinks

     A *note set: 184. object indicating which functions in the *note
     os: a5. module accept ‘False’ for their 'follow_symlinks' parameter
     on the local platform.  Different platforms provide different
     features, and the underlying functionality Python uses to implement
     'follow_symlinks' is not available on all platforms Python
     supports.  For consistency’s sake, functions that may support
     'follow_symlinks' always allow specifying the parameter, but will
     throw an exception if the functionality is used when it’s not
     locally available.  (Specifying ‘True’ for 'follow_symlinks' is
     always supported on all platforms.)

     To check whether a particular function accepts ‘False’ for its
     'follow_symlinks' parameter, use the ‘in’ operator on
     ‘supports_follow_symlinks’.  As an example, this expression
     evaluates to ‘True’ if you may specify ‘follow_symlinks=False’ when
     calling *note os.stat(): 26d. on the local platform:

          os.stat in os.supports_follow_symlinks

     Added in version 3.3.

 -- Funzione: os.symlink (src, dst, target_is_directory=False, *,
          dir_fd=None)

     Create a symbolic link pointing to 'src' named 'dst'.

     The 'src' parameter refers to the target of the link (the file or
     directory being linked to), and 'dst' is the name of the link being
     created.

     On Windows, a symlink represents either a file or a directory, and
     does not morph to the target dynamically.  If the target is
     present, the type of the symlink will be created to match.
     Otherwise, the symlink will be created as a directory if
     'target_is_directory' is ‘True’ or a file symlink (the default)
     otherwise.  On non-Windows platforms, 'target_is_directory' is
     ignored.

     This function can support *note paths relative to directory
     descriptors: 12f2.

          Nota: On newer versions of Windows 10, unprivileged accounts
          can create symlinks if Developer Mode is enabled.  When
          Developer Mode is not available/enabled, the
          'SeCreateSymbolicLinkPrivilege' privilege is required, or the
          process must be run as an administrator.

          *note OSError: 2c0. is raised when the function is called by
          an unprivileged user.

     Raises an *note auditing event: 1c56. ‘os.symlink’ with arguments
     ‘src’, ‘dst’, ‘dir_fd’.

     *note Availability: 2128.: Unix, Windows.

     The function is limited on WASI, see *note WebAssembly platforms:
     1b52. for more information.

     Cambiato nella versione 3.2: Added support for Windows 6.0 (Vista)
     symbolic links.

     Cambiato nella versione 3.3: Added the 'dir_fd' parameter, and now
     allow 'target_is_directory' on non-Windows platforms.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.
     for 'src' and 'dst'.

     Cambiato nella versione 3.8: Added support for unelevated symlinks
     on Windows with Developer Mode.

 -- Funzione: os.sync ()

     Force write of everything to disk.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Funzione: os.truncate (path, length)

     Truncate the file corresponding to 'path', so that it is at most
     'length' bytes in size.

     This function can support *note specifying a file descriptor: d55.

     Raises an *note auditing event: 1c56. ‘os.truncate’ with arguments
     ‘path’, ‘length’.

     *note Availability: 2128.: Unix, Windows.

     Added in version 3.3.

     Cambiato nella versione 3.5: Added support for Windows

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.unlink (path, *, dir_fd=None)

     Remove (delete) the file 'path'.  This function is semantically
     identical to *note remove(): 12f8.; the ‘unlink’ name is its
     traditional Unix name.  Please see the documentation for *note
     remove(): 12f8. for further information.

     Raises an *note auditing event: 1c56. ‘os.remove’ with arguments
     ‘path’, ‘dir_fd’.

     Cambiato nella versione 3.3: Added the 'dir_fd' parameter.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.utime (path, times=None, *[, ns], dir_fd=None,
          follow_symlinks=True)

     Set the access and modified times of the file specified by 'path'.

     *note utime(): 12fe. takes two optional parameters, 'times' and
     'ns'.  These specify the times set on 'path' and are used as
     follows:

        - If 'ns' is specified, it must be a 2-tuple of the form
          ‘(atime_ns, mtime_ns)’ where each member is an int expressing
          nanoseconds.

        - If 'times' is not ‘None’, it must be a 2-tuple of the form
          ‘(atime, mtime)’ where each member is an int or float
          expressing seconds.

        - If 'times' is ‘None’ and 'ns' is unspecified, this is
          equivalent to specifying ‘ns=(atime_ns, mtime_ns)’ where both
          times are the current time.

     It is an error to specify tuples for both 'times' and 'ns'.

     Note that the exact times you set here may not be returned by a
     subsequent *note stat(): 26d. call, depending on the resolution
     with which your operating system records access and modification
     times; see *note stat(): 26d.  The best way to preserve exact times
     is to use the 'st_atime_ns' and 'st_mtime_ns' fields from the *note
     os.stat(): 26d. result object with the 'ns' parameter to *note
     utime(): 12fe.

     This function can support *note specifying a file descriptor: d55,
     *note paths relative to directory descriptors: 12f2. and *note not
     following symlinks: 12f3.

     Raises an *note auditing event: 1c56. ‘os.utime’ with arguments
     ‘path’, ‘times’, ‘ns’, ‘dir_fd’.

     Cambiato nella versione 3.3: Added support for specifying 'path' as
     an open file descriptor, and the 'dir_fd', 'follow_symlinks', and
     'ns' parameters.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.walk (top, topdown=True, onerror=None,
          followlinks=False)

     Generate the file names in a directory tree by walking the tree
     either top-down or bottom-up.  For each directory in the tree
     rooted at directory 'top' (including 'top' itself), it yields a
     3-tuple ‘(dirpath, dirnames, filenames)’.

     'dirpath' is a string, the path to the directory.  'dirnames' is a
     list of the names of the subdirectories in 'dirpath' (including
     symlinks to directories, and excluding ‘'.'’ and ‘'..'’).
     'filenames' is a list of the names of the non-directory files in
     'dirpath'.  Note that the names in the lists contain no path
     components.  To get a full path (which begins with 'top') to a file
     or directory in 'dirpath', do ‘os.path.join(dirpath, name)’.
     Whether or not the lists are sorted depends on the file system.  If
     a file is removed from or added to the 'dirpath' directory during
     generating the lists, whether a name for that file be included is
     unspecified.

     If optional argument 'topdown' is ‘True’ or not specified, the
     triple for a directory is generated before the triples for any of
     its subdirectories (directories are generated top-down).  If
     'topdown' is ‘False’, the triple for a directory is generated after
     the triples for all of its subdirectories (directories are
     generated bottom-up).  No matter the value of 'topdown', the list
     of subdirectories is retrieved before the tuples for the directory
     and its subdirectories are generated.

     When 'topdown' is ‘True’, the caller can modify the 'dirnames' list
     in-place (perhaps using *note del: 1b07. or slice assignment), and
     *note walk(): 6d1. will only recurse into the subdirectories whose
     names remain in 'dirnames'; this can be used to prune the search,
     impose a specific order of visiting, or even to inform *note
     walk(): 6d1. about directories the caller creates or renames before
     it resumes *note walk(): 6d1. again.  Modifying 'dirnames' when
     'topdown' is ‘False’ has no effect on the behavior of the walk,
     because in bottom-up mode the directories in 'dirnames' are
     generated before 'dirpath' itself is generated.

     By default, errors from the *note scandir(): c56. call are ignored.
     If optional argument 'onerror' is specified, it should be a
     function; it will be called with one argument, an *note OSError:
     2c0. instance.  It can report the error to continue with the walk,
     or raise the exception to abort the walk.  Note that the filename
     is available as the ‘filename’ attribute of the exception object.

     By default, *note walk(): 6d1. will not walk down into symbolic
     links that resolve to directories.  Set 'followlinks' to ‘True’ to
     visit directories pointed to by symlinks, on systems that support
     them.

          Nota: Be aware that setting 'followlinks' to ‘True’ can lead
          to infinite recursion if a link points to a parent directory
          of itself.  *note walk(): 6d1. does not keep track of the
          directories it visited already.

          Nota: If you pass a relative pathname, don’t change the
          current working directory between resumptions of *note walk():
          6d1.  *note walk(): 6d1. never changes the current directory,
          and assumes that its caller doesn’t either.

     This example displays the number of bytes taken by non-directory
     files in each directory under the starting directory, except that
     it doesn’t look under any ‘__pycache__’ subdirectory:

          import os
          from os.path import join, getsize
          for root, dirs, files in os.walk('python/Lib/xml'):
              print(root, "consumes", end=" ")
              print(sum(getsize(join(root, name)) for name in files), end=" ")
              print("bytes in", len(files), "non-directory files")
              if '__pycache__' in dirs:
                  dirs.remove('__pycache__')  # don't visit __pycache__ directories

     In the next example (simple implementation of *note
     shutil.rmtree(): 356.), walking the tree bottom-up is essential,
     *note rmdir(): 12fb. doesn’t allow deleting a directory before the
     directory is empty:

          # Delete everything reachable from the directory named in "top",
          # assuming there are no symbolic links.
          # CAUTION:  This is dangerous!  For example, if top == '/', it
          # could delete all your disk files.
          import os
          for root, dirs, files in os.walk(top, topdown=False):
              for name in files:
                  os.remove(os.path.join(root, name))
              for name in dirs:
                  os.rmdir(os.path.join(root, name))
          os.rmdir(top)

     Raises an *note auditing event: 1c56. ‘os.walk’ with arguments
     ‘top’, ‘topdown’, ‘onerror’, ‘followlinks’.

     Cambiato nella versione 3.5: This function now calls *note
     os.scandir(): c56. instead of *note os.listdir(): 1302, making it
     faster by reducing the number of calls to *note os.stat(): 26d.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.fwalk (top='.', topdown=True, onerror=None, *,
          follow_symlinks=False, dir_fd=None)

     This behaves exactly like *note walk(): 6d1, except that it yields
     a 4-tuple ‘(dirpath, dirnames, filenames, dirfd)’, and it supports
     ‘dir_fd’.

     'dirpath', 'dirnames' and 'filenames' are identical to *note
     walk(): 6d1. output, and 'dirfd' is a file descriptor referring to
     the directory 'dirpath'.

     This function always supports *note paths relative to directory
     descriptors: 12f2. and *note not following symlinks: 12f3.  Note
     however that, unlike other functions, the *note fwalk(): d54.
     default value for 'follow_symlinks' is ‘False’.

          Nota: Since *note fwalk(): d54. yields file descriptors, those
          are only valid until the next iteration step, so you should
          duplicate them (e.g.  with *note dup(): 1daa.) if you want to
          keep them longer.

     This example displays the number of bytes taken by non-directory
     files in each directory under the starting directory, except that
     it doesn’t look under any ‘__pycache__’ subdirectory:

          import os
          for root, dirs, files, rootfd in os.fwalk('python/Lib/xml'):
              print(root, "consumes", end=" ")
              print(sum([os.stat(name, dir_fd=rootfd).st_size for name in files]),
                    end=" ")
              print("bytes in", len(files), "non-directory files")
              if '__pycache__' in dirs:
                  dirs.remove('__pycache__')  # don't visit __pycache__ directories

     In the next example, walking the tree bottom-up is essential: *note
     rmdir(): 12fb. doesn’t allow deleting a directory before the
     directory is empty:

          # Delete everything reachable from the directory named in "top",
          # assuming there are no symbolic links.
          # CAUTION:  This is dangerous!  For example, if top == '/', it
          # could delete all your disk files.
          import os
          for root, dirs, files, rootfd in os.fwalk(top, topdown=False):
              for name in files:
                  os.unlink(name, dir_fd=rootfd)
              for name in dirs:
                  os.rmdir(name, dir_fd=rootfd)

     Raises an *note auditing event: 1c56. ‘os.fwalk’ with arguments
     ‘top’, ‘topdown’, ‘onerror’, ‘follow_symlinks’, ‘dir_fd’.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.7: Added support for *note bytes: 192.
     paths.

 -- Funzione: os.memfd_create (name[, flags=os.MFD_CLOEXEC])

     Create an anonymous file and return a file descriptor that refers
     to it.  'flags' must be one of the ‘os.MFD_*’ constants available
     on the system (or a bitwise ORed combination of them).  By default,
     the new file descriptor is *note non-inheritable: 10fe.

     The name supplied in 'name' is used as a filename and will be
     displayed as the target of the corresponding symbolic link in the
     directory ‘/proc/self/fd/’.  The displayed name is always prefixed
     with ‘memfd:’ and serves only for debugging purposes.  Names do not
     affect the behavior of the file descriptor, and as such multiple
     files can have the same name without any side effects.

     *note Availability: 2128.: Linux >= 3.17 with glibc >= 2.27.

     Added in version 3.8.

 -- Dati: os.MFD_CLOEXEC
 -- Dati: os.MFD_ALLOW_SEALING
 -- Dati: os.MFD_HUGETLB
 -- Dati: os.MFD_HUGE_SHIFT
 -- Dati: os.MFD_HUGE_MASK
 -- Dati: os.MFD_HUGE_64KB
 -- Dati: os.MFD_HUGE_512KB
 -- Dati: os.MFD_HUGE_1MB
 -- Dati: os.MFD_HUGE_2MB
 -- Dati: os.MFD_HUGE_8MB
 -- Dati: os.MFD_HUGE_16MB
 -- Dati: os.MFD_HUGE_32MB
 -- Dati: os.MFD_HUGE_256MB
 -- Dati: os.MFD_HUGE_512MB
 -- Dati: os.MFD_HUGE_1GB
 -- Dati: os.MFD_HUGE_2GB
 -- Dati: os.MFD_HUGE_16GB

     These flags can be passed to *note memfd_create(): c00.

     *note Availability: 2128.: Linux >= 3.17 with glibc >= 2.27

     The ‘MFD_HUGE*’ flags are only available since Linux 4.14.

     Added in version 3.8.

 -- Funzione: os.eventfd (initval[, flags=os.EFD_CLOEXEC])

     Create and return an event file descriptor.  The file descriptors
     supports raw *note read(): f97. and *note write(): f9d. with a
     buffer size of 8, *note select(): fa2, *note poll(): 308e. and
     similar.  See man page ‘eventfd(2)(9)’ for more information.  By
     default, the new file descriptor is *note non-inheritable: 10fe.

     'initval' is the initial value of the event counter.  The initial
     value must be a 32 bit unsigned integer.  Please note that the
     initial value is limited to a 32 bit unsigned int although the
     event counter is an unsigned 64 bit integer with a maximum value of
     2^64-2.

     'flags' can be constructed from *note EFD_CLOEXEC: 1b40, *note
     EFD_NONBLOCK: 1b41, and *note EFD_SEMAPHORE: 1b42.

     If *note EFD_SEMAPHORE: 1b42. is specified and the event counter is
     non-zero, *note eventfd_read(): 308f. returns 1 and decrements the
     counter by one.

     If *note EFD_SEMAPHORE: 1b42. is not specified and the event
     counter is non-zero, *note eventfd_read(): 308f. returns the
     current event counter value and resets the counter to zero.

     If the event counter is zero and *note EFD_NONBLOCK: 1b41. is not
     specified, *note eventfd_read(): 308f. blocks.

     *note eventfd_write(): 3090. increments the event counter.  Write
     blocks if the write operation would increment the counter to a
     value larger than 2^64-2.

     Example:

          import os

          # semaphore with start value '1'
          fd = os.eventfd(1, os.EFD_SEMAPHORE | os.EFD_CLOEXEC)
          try:
              # acquire semaphore
              v = os.eventfd_read(fd)
              try:
                  do_work()
              finally:
                  # release semaphore
                  os.eventfd_write(fd, v)
          finally:
              os.close(fd)

     *note Availability: 2128.: Linux >= 2.6.27 with glibc >= 2.8

     Added in version 3.10.

 -- Funzione: os.eventfd_read (fd)

     Read value from an *note eventfd(): a1b. file descriptor and return
     a 64 bit unsigned int.  The function does not verify that 'fd' is
     an *note eventfd(): a1b.

     *note Availability: 2128.: Linux >= 2.6.27

     Added in version 3.10.

 -- Funzione: os.eventfd_write (fd, value)

     Add value to an *note eventfd(): a1b. file descriptor.  'value'
     must be a 64 bit unsigned int.  The function does not verify that
     'fd' is an *note eventfd(): a1b.

     *note Availability: 2128.: Linux >= 2.6.27

     Added in version 3.10.

 -- Dati: os.EFD_CLOEXEC

     Set close-on-exec flag for new *note eventfd(): a1b. file
     descriptor.

     *note Availability: 2128.: Linux >= 2.6.27

     Added in version 3.10.

 -- Dati: os.EFD_NONBLOCK

     Set *note O_NONBLOCK: 103d. status flag for new *note eventfd():
     a1b. file descriptor.

     *note Availability: 2128.: Linux >= 2.6.27

     Added in version 3.10.

 -- Dati: os.EFD_SEMAPHORE

     Provide semaphore-like semantics for reads from an *note eventfd():
     a1b. file descriptor.  On read the internal counter is decremented
     by one.

     *note Availability: 2128.: Linux >= 2.6.30

     Added in version 3.10.

* Menu:

* Timer File Descriptors::
* Linux extended attributes::

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/access(2)

   (2) https://peps.python.org/pep-0529/

   (3) https://bugs.python.org/issue?@action=redirect&bpo=21082

   (4) 
https://pubs.opengroup.org/onlinepubs/009695399/functions/opendir.html

   (5) 
https://pubs.opengroup.org/onlinepubs/009695399/functions/readdir_r.html

   (6) 
https://msdn.microsoft.com/en-us/library/windows/desktop/aa364418(v=vs.85).aspx

   (7) 
https://msdn.microsoft.com/en-us/library/windows/desktop/aa364428(v=vs.85).aspx

   (8) https://msdn.microsoft.com/en-us/library/aa363788

   (9) https://manpages.debian.org/eventfd(2)


File: python.info,  Node: Timer File Descriptors,  Next: Linux extended attributes,  Up: Files and Directories

5.16.1.9 Timer File Descriptors
...............................

Added in version 3.13.

These functions provide support for Linux’s 'timer file descriptor' API.
Naturally, they are all only available on Linux.

 -- Funzione: os.timerfd_create (clockid, /, *, flags=0)

     Create and return a timer file descriptor ('timerfd').

     The file descriptor returned by *note timerfd_create(): 520.
     supports:

        - *note read(): f97.

        - *note select(): fa2.

        - *note poll(): 308e.

     The file descriptor’s *note read(): f97. method can be called with
     a buffer size of 8.  If the timer has already expired one or more
     times, *note read(): f97. returns the number of expirations with
     the host’s endianness, which may be converted to an *note int: 19b.
     by ‘int.from_bytes(x, byteorder=sys.byteorder)’.

     *note select(): fa2. and *note poll(): 308e. can be used to wait
     until timer expires and the file descriptor is readable.

     'clockid' must be a valid *note clock ID: 3092, as defined in the
     *note time: f4. module:

        - *note time.CLOCK_REALTIME: 8aa.

        - *note time.CLOCK_MONOTONIC: 8a9.

        - *note time.CLOCK_BOOTTIME: d89. (Since Linux 3.15 for
          timerfd_create)

     If 'clockid' is *note time.CLOCK_REALTIME: 8aa, a settable
     system-wide real-time clock is used.  If system clock is changed,
     timer setting need to be updated.  To cancel timer when system
     clock is changed, see *note TFD_TIMER_CANCEL_ON_SET: 528.

     If 'clockid' is *note time.CLOCK_MONOTONIC: 8a9, a non-settable
     monotonically increasing clock is used.  Even if the system clock
     is changed, the timer setting will not be affected.

     If 'clockid' is *note time.CLOCK_BOOTTIME: d89, same as *note
     time.CLOCK_MONOTONIC: 8a9. except it includes any time that the
     system is suspended.

     The file descriptor’s behaviour can be modified by specifying a
     'flags' value.  Any of the following variables may used, combined
     using bitwise OR (the ‘|’ operator):

        - *note TFD_NONBLOCK: 525.

        - *note TFD_CLOEXEC: 526.

     If *note TFD_NONBLOCK: 525. is not set as a flag, *note read():
     f97. blocks until the timer expires.  If it is set as a flag, *note
     read(): f97. doesn’t block, but If there hasn’t been an expiration
     since the last call to read, *note read(): f97. raises *note
     OSError: 2c0. with ‘errno’ is set to *note errno.EAGAIN: 26e0.

     *note TFD_CLOEXEC: 526. is always set by Python automatically.

     The file descriptor must be closed with *note os.close(): d6d. when
     it is no longer needed, or else the file descriptor will be leaked.

     Vedi anche
     ..........

     The ‘timerfd_create(2)(1)’ man page.

     *note Availability: 2128.: Linux >= 2.6.27 with glibc >= 2.8

     Added in version 3.13.

 -- Funzione: os.timerfd_settime (fd, /, *, flags=flags, initial=0.0,
          interval=0.0)

     Alter a timer file descriptor’s internal timer.  This function
     operates the same interval timer as *note timerfd_settime_ns():
     522.

     'fd' must be a valid timer file descriptor.

     The timer’s behaviour can be modified by specifying a 'flags'
     value.  Any of the following variables may used, combined using
     bitwise OR (the ‘|’ operator):

        - *note TFD_TIMER_ABSTIME: 527.

        - *note TFD_TIMER_CANCEL_ON_SET: 528.

     The timer is disabled by setting 'initial' to zero (‘0’).  If
     'initial' is equal to or greater than zero, the timer is enabled.
     If 'initial' is less than zero, it raises an *note OSError: 2c0.
     exception with ‘errno’ set to *note errno.EINVAL: 1dba.

     By default the timer will fire when 'initial' seconds have elapsed.
     (If 'initial' is zero, timer will fire immediately.)

     However, if the *note TFD_TIMER_ABSTIME: 527. flag is set, the
     timer will fire when the timer’s clock (set by 'clockid' in *note
     timerfd_create(): 520.) reaches 'initial' seconds.

     The timer’s interval is set by the 'interval' *note float: 196.  If
     'interval' is zero, the timer only fires once, on the initial
     expiration.  If 'interval' is greater than zero, the timer fires
     every time 'interval' seconds have elapsed since the previous
     expiration.  If 'interval' is less than zero, it raises *note
     OSError: 2c0. with ‘errno’ set to *note errno.EINVAL: 1dba.

     If the *note TFD_TIMER_CANCEL_ON_SET: 528. flag is set along with
     *note TFD_TIMER_ABSTIME: 527. and the clock for this timer is *note
     time.CLOCK_REALTIME: 8aa, the timer is marked as cancelable if the
     real-time clock is changed discontinuously.  Reading the descriptor
     is aborted with the error ECANCELED.

     Linux manages system clock as UTC. A daylight-savings time
     transition is done by changing time offset only and doesn’t cause
     discontinuous system clock change.

     Discontinuous system clock change will be caused by the following
     events:

        - ‘settimeofday’

        - ‘clock_settime’

        - set the system date and time by ‘date’ command

     Return a two-item tuple of (‘next_expiration’, ‘interval’) from the
     previous timer state, before this function executed.

     Vedi anche
     ..........

     ‘timerfd_create(2)(2)’, ‘timerfd_settime(2)(3)’,
     ‘settimeofday(2)(4)’, ‘clock_settime(2)(5)’, and ‘date(1)(6)’.

     *note Availability: 2128.: Linux >= 2.6.27 with glibc >= 2.8

     Added in version 3.13.

 -- Funzione: os.timerfd_settime_ns (fd, /, *, flags=0, initial=0,
          interval=0)

     Similar to *note timerfd_settime(): 521, but use time as
     nanoseconds.  This function operates the same interval timer as
     *note timerfd_settime(): 521.

     *note Availability: 2128.: Linux >= 2.6.27 with glibc >= 2.8

     Added in version 3.13.

 -- Funzione: os.timerfd_gettime (fd, /)

     Return a two-item tuple of floats (‘next_expiration’, ‘interval’).

     ‘next_expiration’ denotes the relative time until next the timer
     next fires, regardless of if the *note TFD_TIMER_ABSTIME: 527. flag
     is set.

     ‘interval’ denotes the timer’s interval.  If zero, the timer will
     only fire once, after ‘next_expiration’ seconds have elapsed.

     Vedi anche
     ..........

     ‘timerfd_gettime(2)(7)’

     *note Availability: 2128.: Linux >= 2.6.27 with glibc >= 2.8

     Added in version 3.13.

 -- Funzione: os.timerfd_gettime_ns (fd, /)

     Similar to *note timerfd_gettime(): 523, but return time as
     nanoseconds.

     *note Availability: 2128.: Linux >= 2.6.27 with glibc >= 2.8

     Added in version 3.13.

 -- Dati: os.TFD_NONBLOCK

     A flag for the *note timerfd_create(): 520. function, which sets
     the *note O_NONBLOCK: 103d. status flag for the new timer file
     descriptor.  If *note TFD_NONBLOCK: 525. is not set as a flag,
     *note read(): f97. blocks.

     *note Availability: 2128.: Linux >= 2.6.27 with glibc >= 2.8

     Added in version 3.13.

 -- Dati: os.TFD_CLOEXEC

     A flag for the *note timerfd_create(): 520. function, If *note
     TFD_CLOEXEC: 526. is set as a flag, set close-on-exec flag for new
     file descriptor.

     *note Availability: 2128.: Linux >= 2.6.27 with glibc >= 2.8

     Added in version 3.13.

 -- Dati: os.TFD_TIMER_ABSTIME

     A flag for the *note timerfd_settime(): 521. and *note
     timerfd_settime_ns(): 522. functions.  If this flag is set,
     'initial' is interpreted as an absolute value on the timer’s clock
     (in UTC seconds or nanoseconds since the Unix Epoch).

     *note Availability: 2128.: Linux >= 2.6.27 with glibc >= 2.8

     Added in version 3.13.

 -- Dati: os.TFD_TIMER_CANCEL_ON_SET

     A flag for the *note timerfd_settime(): 521. and *note
     timerfd_settime_ns(): 522. functions along with *note
     TFD_TIMER_ABSTIME: 527.  The timer is cancelled when the time of
     the underlying clock changes discontinuously.

     *note Availability: 2128.: Linux >= 2.6.27 with glibc >= 2.8

     Added in version 3.13.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/timerfd_create(2)

   (2) https://manpages.debian.org/timerfd_create(2)

   (3) https://manpages.debian.org/timerfd_settime(2)

   (4) https://manpages.debian.org/settimeofday(2)

   (5) https://manpages.debian.org/clock_settime(2)

   (6) https://manpages.debian.org/date(1)

   (7) https://manpages.debian.org/timerfd_gettime(2)


File: python.info,  Node: Linux extended attributes,  Prev: Timer File Descriptors,  Up: Files and Directories

5.16.1.10 Linux extended attributes
...................................

Added in version 3.3.

These functions are all available on Linux only.

 -- Funzione: os.getxattr (path, attribute, *, follow_symlinks=True)

     Return the value of the extended filesystem attribute 'attribute'
     for 'path'.  'attribute' can be bytes or str (directly or
     indirectly through the *note PathLike: e4d. interface).  If it is
     str, it is encoded with the filesystem encoding.

     This function can support *note specifying a file descriptor: d55.
     and *note not following symlinks: 12f3.

     Raises an *note auditing event: 1c56. ‘os.getxattr’ with arguments
     ‘path’, ‘attribute’.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.
     for 'path' and 'attribute'.

 -- Funzione: os.listxattr (path=None, *, follow_symlinks=True)

     Return a list of the extended filesystem attributes on 'path'.  The
     attributes in the list are represented as strings decoded with the
     filesystem encoding.  If 'path' is ‘None’, *note listxattr(): 130d.
     will examine the current directory.

     This function can support *note specifying a file descriptor: d55.
     and *note not following symlinks: 12f3.

     Raises an *note auditing event: 1c56. ‘os.listxattr’ with argument
     ‘path’.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os.removexattr (path, attribute, *, follow_symlinks=True)

     Removes the extended filesystem attribute 'attribute' from 'path'.
     'attribute' should be bytes or str (directly or indirectly through
     the *note PathLike: e4d. interface).  If it is a string, it is
     encoded with the *note filesystem encoding and error handler: 75e.

     This function can support *note specifying a file descriptor: d55.
     and *note not following symlinks: 12f3.

     Raises an *note auditing event: 1c56. ‘os.removexattr’ with
     arguments ‘path’, ‘attribute’.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.
     for 'path' and 'attribute'.

 -- Funzione: os.setxattr (path, attribute, value, flags=0, *,
          follow_symlinks=True)

     Set the extended filesystem attribute 'attribute' on 'path' to
     'value'.  'attribute' must be a bytes or str with no embedded NULs
     (directly or indirectly through the *note PathLike: e4d.
     interface).  If it is a str, it is encoded with the *note
     filesystem encoding and error handler: 75e.  'flags' may be *note
     XATTR_REPLACE: 3094. or *note XATTR_CREATE: 3095.  If *note
     XATTR_REPLACE: 3094. is given and the attribute does not exist,
     ‘ENODATA’ will be raised.  If *note XATTR_CREATE: 3095. is given
     and the attribute already exists, the attribute will not be created
     and ‘EEXISTS’ will be raised.

     This function can support *note specifying a file descriptor: d55.
     and *note not following symlinks: 12f3.

          Nota: A bug in Linux kernel versions less than 2.6.39 caused
          the flags argument to be ignored on some filesystems.

     Raises an *note auditing event: 1c56. ‘os.setxattr’ with arguments
     ‘path’, ‘attribute’, ‘value’, ‘flags’.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.
     for 'path' and 'attribute'.

 -- Dati: os.XATTR_SIZE_MAX

     The maximum size the value of an extended attribute can be.
     Currently, this is 64 KiB on Linux.

 -- Dati: os.XATTR_CREATE

     This is a possible value for the flags argument in *note
     setxattr(): 130f.  It indicates the operation must create an
     attribute.

 -- Dati: os.XATTR_REPLACE

     This is a possible value for the flags argument in *note
     setxattr(): 130f.  It indicates the operation must replace an
     existing attribute.


File: python.info,  Node: Process Management,  Next: Interface to the scheduler,  Prev: Files and Directories,  Up: os — Miscellaneous operating system interfaces

5.16.1.11 Process Management
............................

These functions may be used to create and manage processes.

The various *note exec*: 3099. functions take a list of arguments for
the new program loaded into the process.  In each case, the first of
these arguments is passed to the new program as its own name rather than
as an argument a user may have typed on a command line.  For the C
programmer, this is the ‘argv[0]’ passed to a program’s ‘main()’.  For
example, ‘os.execv('/bin/echo', ['foo', 'bar'])’ will only print ‘bar’
on standard output; ‘foo’ will seem to be ignored.

 -- Funzione: os.abort ()

     Generate a ‘SIGABRT’ signal to the current process.  On Unix, the
     default behavior is to produce a core dump; on Windows, the process
     immediately returns an exit code of ‘3’.  Be aware that calling
     this function will not call the Python signal handler registered
     for ‘SIGABRT’ with *note signal.signal(): 133c.

 -- Funzione: os.add_dll_directory (path)

     Add a path to the DLL search path.

     This search path is used when resolving dependencies for imported
     extension modules (the module itself is resolved through *note
     sys.path: 3e4.), and also by *note ctypes: 2e.

     Remove the directory by calling 'close()' on the returned object or
     using it in a *note with: 186. statement.

     See the Microsoft documentation(1) for more information about how
     DLLs are loaded.

     Raises an *note auditing event: 1c56. ‘os.add_dll_directory’ with
     argument ‘path’.

     *note Availability: 2128.: Windows.

     Added in version 3.8: Previous versions of CPython would resolve
     DLLs using the default behavior for the current process.  This led
     to inconsistencies, such as only sometimes searching ‘PATH’ or the
     current working directory, and OS functions such as
     ‘AddDllDirectory’ having no effect.

     In 3.8, the two primary ways DLLs are loaded now explicitly
     override the process-wide behavior to ensure consistency.  See the
     *note porting notes: c97. for information on updating libraries.

 -- Funzione: os.execl (path, arg0, arg1, ...)
 -- Funzione: os.execle (path, arg0, arg1, ..., env)
 -- Funzione: os.execlp (file, arg0, arg1, ...)
 -- Funzione: os.execlpe (file, arg0, arg1, ..., env)
 -- Funzione: os.execv (path, args)
 -- Funzione: os.execve (path, args, env)
 -- Funzione: os.execvp (file, args)
 -- Funzione: os.execvpe (file, args, env)

     These functions all execute a new program, replacing the current
     process; they do not return.  On Unix, the new executable is loaded
     into the current process, and will have the same process id as the
     caller.  Errors will be reported as *note OSError: 2c0. exceptions.

     The current process is replaced immediately.  Open file objects and
     descriptors are not flushed, so if there may be data buffered on
     these open files, you should flush them using ‘sys.stdout.flush()’
     or *note os.fsync(): f90. before calling an *note exec*: 3099.
     function.

     The «l» and «v» variants of the *note exec*: 3099. functions differ
     in how command-line arguments are passed.  The «l» variants are
     perhaps the easiest to work with if the number of parameters is
     fixed when the code is written; the individual parameters simply
     become additional parameters to the ‘execl*()’ functions.  The «v»
     variants are good when the number of parameters is variable, with
     the arguments being passed in a list or tuple as the 'args'
     parameter.  In either case, the arguments to the child process
     should start with the name of the command being run, but this is
     not enforced.

     The variants which include a «p» near the end (*note execlp():
     309c, *note execlpe(): 309d, *note execvp(): 309e, and *note
     execvpe(): 309f.) will use the ‘PATH’ environment variable to
     locate the program 'file'.  When the environment is being replaced
     (using one of the *note exec*e: 3099. variants, discussed in the
     next paragraph), the new environment is used as the source of the
     ‘PATH’ variable.  The other variants, *note execl(): 3099, *note
     execle(): 309b, *note execv(): 2ffe, and *note execve(): 1301, will
     not use the ‘PATH’ variable to locate the executable; 'path' must
     contain an appropriate absolute or relative path.  Relative paths
     must include at least one slash, even on Windows, as plain names
     will not be resolved.

     For *note execle(): 309b, *note execlpe(): 309d, *note execve():
     1301, and *note execvpe(): 309f. (note that these all end in «e»),
     the 'env' parameter must be a mapping which is used to define the
     environment variables for the new process (these are used instead
     of the current process” environment); the functions *note execl():
     3099, *note execlp(): 309c, *note execv(): 2ffe, and *note
     execvp(): 309e. all cause the new process to inherit the
     environment of the current process.

     For *note execve(): 1301. on some platforms, 'path' may also be
     specified as an open file descriptor.  This functionality may not
     be supported on your platform; you can check whether or not it is
     available using *note os.supports_fd: 1305.  If it is unavailable,
     using it will raise a *note NotImplementedError: 36b.

     Raises an *note auditing event: 1c56. ‘os.exec’ with arguments
     ‘path’, ‘args’, ‘env’.

     *note Availability: 2128.: Unix, Windows, not WASI, not Android,
     not iOS.

     Cambiato nella versione 3.3: Added support for specifying 'path' as
     an open file descriptor for *note execve(): 1301.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: os._exit (n)

     Exit the process with status 'n', without calling cleanup handlers,
     flushing stdio buffers, etc.

          Nota: The standard way to exit is *note sys.exit(n): 277.
          ‘_exit()’ should normally only be used in the child process
          after a *note fork(): 4b6.

The following exit codes are defined and can be used with *note _exit():
26dc, although they are not required.  These are typically used for
system programs written in Python, such as a mail server’s external
command delivery program.

     Nota: Some of these may not be available on all Unix platforms,
     since there is some variation.  These constants are defined where
     they are defined by the underlying platform.

 -- Dati: os.EX_OK

     Exit code that means no error occurred.  May be taken from the
     defined value of ‘EXIT_SUCCESS’ on some platforms.  Generally has a
     value of zero.

     *note Availability: 2128.: Unix, Windows.

 -- Dati: os.EX_USAGE

     Exit code that means the command was used incorrectly, such as when
     the wrong number of arguments are given.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_DATAERR

     Exit code that means the input data was incorrect.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_NOINPUT

     Exit code that means an input file did not exist or was not
     readable.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_NOUSER

     Exit code that means a specified user did not exist.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_NOHOST

     Exit code that means a specified host did not exist.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_UNAVAILABLE

     Exit code that means that a required service is unavailable.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_SOFTWARE

     Exit code that means an internal software error was detected.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_OSERR

     Exit code that means an operating system error was detected, such
     as the inability to fork or create a pipe.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_OSFILE

     Exit code that means some system file did not exist, could not be
     opened, or had some other kind of error.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_CANTCREAT

     Exit code that means a user specified output file could not be
     created.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_IOERR

     Exit code that means that an error occurred while doing I/O on some
     file.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_TEMPFAIL

     Exit code that means a temporary failure occurred.  This indicates
     something that may not really be an error, such as a network
     connection that couldn’t be made during a retryable operation.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_PROTOCOL

     Exit code that means that a protocol exchange was illegal, invalid,
     or not understood.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_NOPERM

     Exit code that means that there were insufficient permissions to
     perform the operation (but not intended for file system problems).

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_CONFIG

     Exit code that means that some kind of configuration error
     occurred.

     *note Availability: 2128.: Unix, not WASI.

 -- Dati: os.EX_NOTFOUND

     Exit code that means something like «an entry was not found».

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.fork ()

     Fork a child process.  Return ‘0’ in the child and the child’s
     process id in the parent.  If an error occurs *note OSError: 2c0.
     is raised.

     Note that some platforms including FreeBSD <= 6.3 and Cygwin have
     known issues when using ‘fork()’ from a thread.

     Raises an *note auditing event: 1c56. ‘os.fork’ with no arguments.

          Avvertimento: If you use TLS sockets in an application calling
          ‘fork()’, see the warning in the *note ssl: d5. documentation.

          Avvertimento: On macOS the use of this function is unsafe when
          mixed with using higher-level system APIs, and that includes
          using *note urllib.request: 111.

     Cambiato nella versione 3.8: Calling ‘fork()’ in a subinterpreter
     is no longer supported (*note RuntimeError: 244. is raised).

     Cambiato nella versione 3.12: If Python is able to detect that your
     process has multiple threads, *note os.fork(): 4b6. now raises a
     *note DeprecationWarning: 1a3.

     We chose to surface this as a warning, when detectable, to better
     inform developers of a design problem that the POSIX platform
     specifically notes as not supported.  Even in code that 'appears'
     to work, it has never been safe to mix threading with *note
     os.fork(): 4b6. on POSIX platforms.  The CPython runtime itself has
     always made API calls that are not safe for use in the child
     process when threads existed in the parent (such as ‘malloc’ and
     ‘free’).

     Users of macOS or users of libc or malloc implementations other
     than those typically found in glibc to date are among those already
     more likely to experience deadlocks running such code.

     See this discussion on fork being incompatible with threads(2) for
     technical details of why we’re surfacing this longstanding platform
     compatibility problem to developers.

     *note Availability: 2128.: POSIX, not WASI, not Android, not iOS.

 -- Funzione: os.forkpty ()

     Fork a child process, using a new pseudo-terminal as the child’s
     controlling terminal.  Return a pair of ‘(pid, fd)’, where 'pid' is
     ‘0’ in the child, the new child’s process id in the parent, and
     'fd' is the file descriptor of the master end of the
     pseudo-terminal.  For a more portable approach, use the *note pty:
     b6. module.  If an error occurs *note OSError: 2c0. is raised.

     Raises an *note auditing event: 1c56. ‘os.forkpty’ with no
     arguments.

          Avvertimento: On macOS the use of this function is unsafe when
          mixed with using higher-level system APIs, and that includes
          using *note urllib.request: 111.

     Cambiato nella versione 3.8: Calling ‘forkpty()’ in a
     subinterpreter is no longer supported (*note RuntimeError: 244. is
     raised).

     Cambiato nella versione 3.12: If Python is able to detect that your
     process has multiple threads, this now raises a *note
     DeprecationWarning: 1a3.  See the longer explanation on *note
     os.fork(): 4b6.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Funzione: os.kill (pid, sig, /)

     Send signal 'sig' to the process 'pid'.  Constants for the specific
     signals available on the host platform are defined in the *note
     signal: cb. module.

     Windows: The *note signal.CTRL_C_EVENT: 1570. and *note
     signal.CTRL_BREAK_EVENT: 1571. signals are special signals which
     can only be sent to console processes which share a common console
     window, e.g., some subprocesses.  Any other value for 'sig' will
     cause the process to be unconditionally killed by the
     TerminateProcess API, and the exit code will be set to 'sig'.

     See also *note signal.pthread_kill(): 1339.

     Raises an *note auditing event: 1c56. ‘os.kill’ with arguments
     ‘pid’, ‘sig’.

     *note Availability: 2128.: Unix, Windows, not WASI, not iOS.

     Cambiato nella versione 3.2: Added Windows support.

 -- Funzione: os.killpg (pgid, sig, /)

     Send the signal 'sig' to the process group 'pgid'.

     Raises an *note auditing event: 1c56. ‘os.killpg’ with arguments
     ‘pgid’, ‘sig’.

     *note Availability: 2128.: Unix, not WASI, not iOS.

 -- Funzione: os.nice (increment, /)

     Add 'increment' to the process’s «niceness».  Return the new
     niceness.

     *note Availability: 2128.: Unix, not WASI.

 -- Funzione: os.pidfd_open (pid, flags=0)

     Return a file descriptor referring to the process 'pid' with
     'flags' set.  This descriptor can be used to perform process
     management without races and signals.

     See the ‘pidfd_open(2)(3)’ man page for more details.

     *note Availability: 2128.: Linux >= 5.3, Android >= *note
     build-time: d85. API level 31

     Added in version 3.9.

      -- Dati: os.PIDFD_NONBLOCK

          This flag indicates that the file descriptor will be
          non-blocking.  If the process referred to by the file
          descriptor has not yet terminated, then an attempt to wait on
          the file descriptor using ‘waitid(2)(4)’ will immediately
          return the error *note EAGAIN: 26e0. rather than blocking.

     *note Availability: 2128.: Linux >= 5.10

     Added in version 3.12.

 -- Funzione: os.plock (op, /)

     Lock program segments into memory.  The value of 'op' (defined in
     ‘<sys/lock.h>’) determines which segments are locked.

     *note Availability: 2128.: Unix, not WASI, not iOS.

 -- Funzione: os.popen (cmd, mode='r', buffering=-1)

     Open a pipe to or from command 'cmd'.  The return value is an open
     file object connected to the pipe, which can be read or written
     depending on whether 'mode' is ‘'r'’ (default) or ‘'w'’.  The
     'buffering' argument have the same meaning as the corresponding
     argument to the built-in *note open(): 316. function.  The returned
     file object reads or writes text strings rather than bytes.

     The ‘close’ method returns *note None: 886. if the subprocess
     exited successfully, or the subprocess’s return code if there was
     an error.  On POSIX systems, if the return code is positive it
     represents the return value of the process left-shifted by one
     byte.  If the return code is negative, the process was terminated
     by the signal given by the negated value of the return code.  (For
     example, the return value might be ‘- signal.SIGKILL’ if the
     subprocess was killed.)  On Windows systems, the return value
     contains the signed integer return code from the child process.

     On Unix, *note waitstatus_to_exitcode(): b19. can be used to
     convert the ‘close’ method result (exit status) into an exit code
     if it is not ‘None’.  On Windows, the ‘close’ method result is
     directly the exit code (or ‘None’).

     This is implemented using *note subprocess.Popen: 4b8.; see that
     class’s documentation for more powerful ways to manage and
     communicate with subprocesses.

     *note Availability: 2128.: not WASI, not Android, not iOS.

          Nota: The *note Python UTF-8 Mode: 867. affects encodings used
          for 'cmd' and pipe contents.

          *note popen(): 31a. is a simple wrapper around *note
          subprocess.Popen: 4b8.  Use *note subprocess.Popen: 4b8. or
          *note subprocess.run(): d81. to control options like
          encodings.

     Deprecato dalla versione 3.14: The function is *note soft
     deprecated: 23d. and should no longer be used to write new code.
     The *note subprocess: dc. module is recommended instead.

 -- Funzione: os.posix_spawn (path, argv, env, *, file_actions=None,
          setpgroup=None, resetids=False, setsid=False, setsigmask=(),
          setsigdef=(), scheduler=None)

     Wraps the ‘posix_spawn()’ C library API for use from Python.

     Most users should use *note subprocess.run(): d81. instead of *note
     posix_spawn(): 52f.

     The positional-only arguments 'path', 'args', and 'env' are similar
     to *note execve(): 1301.  'env' is allowed to be ‘None’, in which
     case current process” environment is used.

     The 'path' parameter is the path to the executable file.  The
     'path' should contain a directory.  Use *note posix_spawnp(): 1df9.
     to pass an executable file without directory.

     The 'file_actions' argument may be a sequence of tuples describing
     actions to take on specific file descriptors in the child process
     between the C library implementation’s ‘fork()’ and ‘exec()’ steps.
     The first item in each tuple must be one of the three type
     indicator listed below describing the remaining tuple elements:

      -- Dati: os.POSIX_SPAWN_OPEN

          (‘os.POSIX_SPAWN_OPEN’, 'fd', 'path', 'flags', 'mode')

          Performs ‘os.dup2(os.open(path, flags, mode), fd)’.

      -- Dati: os.POSIX_SPAWN_CLOSE

          (‘os.POSIX_SPAWN_CLOSE’, 'fd')

          Performs ‘os.close(fd)’.

      -- Dati: os.POSIX_SPAWN_DUP2

          (‘os.POSIX_SPAWN_DUP2’, 'fd', 'new_fd')

          Performs ‘os.dup2(fd, new_fd)’.

      -- Dati: os.POSIX_SPAWN_CLOSEFROM

          (‘os.POSIX_SPAWN_CLOSEFROM’, 'fd')

          Performs ‘os.closerange(fd, INF)’.

     These tuples correspond to the C library
     ‘posix_spawn_file_actions_addopen()’,
     ‘posix_spawn_file_actions_addclose()’,
     ‘posix_spawn_file_actions_adddup2()’, and
     ‘posix_spawn_file_actions_addclosefrom_np()’ API calls used to
     prepare for the ‘posix_spawn()’ call itself.

     The 'setpgroup' argument will set the process group of the child to
     the value specified.  If the value specified is 0, the child’s
     process group ID will be made the same as its process ID. If the
     value of 'setpgroup' is not set, the child will inherit the
     parent’s process group ID. This argument corresponds to the C
     library ‘POSIX_SPAWN_SETPGROUP’ flag.

     If the 'resetids' argument is ‘True’ it will reset the effective
     UID and GID of the child to the real UID and GID of the parent
     process.  If the argument is ‘False’, then the child retains the
     effective UID and GID of the parent.  In either case, if the
     set-user-ID and set-group-ID permission bits are enabled on the
     executable file, their effect will override the setting of the
     effective UID and GID. This argument corresponds to the C library
     ‘POSIX_SPAWN_RESETIDS’ flag.

     If the 'setsid' argument is ‘True’, it will create a new session ID
     for ‘posix_spawn’.  'setsid' requires ‘POSIX_SPAWN_SETSID’ or
     ‘POSIX_SPAWN_SETSID_NP’ flag.  Otherwise, *note
     NotImplementedError: 36b. is raised.

     The 'setsigmask' argument will set the signal mask to the signal
     set specified.  If the parameter is not used, then the child
     inherits the parent’s signal mask.  This argument corresponds to
     the C library ‘POSIX_SPAWN_SETSIGMASK’ flag.

     The 'sigdef' argument will reset the disposition of all signals in
     the set specified.  This argument corresponds to the C library
     ‘POSIX_SPAWN_SETSIGDEF’ flag.

     The 'scheduler' argument must be a tuple containing the (optional)
     scheduler policy and an instance of *note sched_param: 18f8. with
     the scheduler parameters.  A value of ‘None’ in the place of the
     scheduler policy indicates that is not being provided.  This
     argument is a combination of the C library
     ‘POSIX_SPAWN_SETSCHEDPARAM’ and ‘POSIX_SPAWN_SETSCHEDULER’ flags.

     Raises an *note auditing event: 1c56. ‘os.posix_spawn’ with
     arguments ‘path’, ‘argv’, ‘env’.

     Added in version 3.8.

     Cambiato nella versione 3.13: 'env' parameter accepts ‘None’.
     ‘os.POSIX_SPAWN_CLOSEFROM’ is available on platforms where
     ‘posix_spawn_file_actions_addclosefrom_np()’ exists.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Funzione: os.posix_spawnp (path, argv, env, *, file_actions=None,
          setpgroup=None, resetids=False, setsid=False, setsigmask=(),
          setsigdef=(), scheduler=None)

     Wraps the ‘posix_spawnp()’ C library API for use from Python.

     Similar to *note posix_spawn(): 52f. except that the system
     searches for the 'executable' file in the list of directories
     specified by the ‘PATH’ environment variable (in the same way as
     for ‘execvp(3)’).

     Raises an *note auditing event: 1c56. ‘os.posix_spawn’ with
     arguments ‘path’, ‘argv’, ‘env’.

     Added in version 3.8.

     *note Availability: 2128.: POSIX, not WASI, not Android, not iOS.

     See *note posix_spawn(): 52f. documentation.

 -- Funzione: os.register_at_fork (*, before=None, after_in_parent=None,
          after_in_child=None)

     Register callables to be executed when a new child process is
     forked using *note os.fork(): 4b6. or similar process cloning APIs.
     The parameters are optional and keyword-only.  Each specifies a
     different call point.

        * 'before' is a function called before forking a child process.

        * 'after_in_parent' is a function called from the parent process
          after forking a child process.

        * 'after_in_child' is a function called from the child process.

     These calls are only made if control is expected to return to the
     Python interpreter.  A typical *note subprocess: dc. launch will
     not trigger them as the child is not going to re-enter the
     interpreter.

     Functions registered for execution before forking are called in
     reverse registration order.  Functions registered for execution
     after forking (either in the parent or in the child) are called in
     registration order.

     Note that ‘fork()’ calls made by third-party C code may not call
     those functions, unless it explicitly calls *note
     PyOS_BeforeFork(): dba, *note PyOS_AfterFork_Parent(): dbb. and
     *note PyOS_AfterFork_Child(): 430.

     There is no way to unregister a function.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

     Added in version 3.7.

 -- Funzione: os.spawnl (mode, path, ...)
 -- Funzione: os.spawnle (mode, path, ..., env)
 -- Funzione: os.spawnlp (mode, file, ...)
 -- Funzione: os.spawnlpe (mode, file, ..., env)
 -- Funzione: os.spawnv (mode, path, args)
 -- Funzione: os.spawnve (mode, path, args, env)
 -- Funzione: os.spawnvp (mode, file, args)
 -- Funzione: os.spawnvpe (mode, file, args, env)

     Execute the program 'path' in a new process.

     (Note that the *note subprocess: dc. module provides more powerful
     facilities for spawning new processes and retrieving their results;
     using that module is preferable to using these functions.  Check
     especially the *note Replacing Older Functions with the subprocess
     Module: 1390. section.)

     If 'mode' is *note P_NOWAIT: 30bc, this function returns the
     process id of the new process; if 'mode' is *note P_WAIT: 30bd,
     returns the process’s exit code if it exits normally, or ‘-signal’,
     where 'signal' is the signal that killed the process.  On Windows,
     the process id will actually be the process handle, so can be used
     with the *note waitpid(): f9c. function.

     Note on VxWorks, this function doesn’t return ‘-signal’ when the
     new process is killed.  Instead it raises OSError exception.

     The «l» and «v» variants of the *note spawn*: 31b. functions differ
     in how command-line arguments are passed.  The «l» variants are
     perhaps the easiest to work with if the number of parameters is
     fixed when the code is written; the individual parameters simply
     become additional parameters to the ‘spawnl*()’ functions.  The «v»
     variants are good when the number of parameters is variable, with
     the arguments being passed in a list or tuple as the 'args'
     parameter.  In either case, the arguments to the child process must
     start with the name of the command being run.

     The variants which include a second «p» near the end (*note
     spawnlp(): 30b6, *note spawnlpe(): 30b7, *note spawnvp(): 30ba, and
     *note spawnvpe(): 30bb.) will use the ‘PATH’ environment variable
     to locate the program 'file'.  When the environment is being
     replaced (using one of the *note spawn*e: 31b. variants, discussed
     in the next paragraph), the new environment is used as the source
     of the ‘PATH’ variable.  The other variants, *note spawnl(): 31b,
     *note spawnle(): 30b5, *note spawnv(): 30b8, and *note spawnve():
     30b9, will not use the ‘PATH’ variable to locate the executable;
     'path' must contain an appropriate absolute or relative path.

     For *note spawnle(): 30b5, *note spawnlpe(): 30b7, *note spawnve():
     30b9, and *note spawnvpe(): 30bb. (note that these all end in «e»),
     the 'env' parameter must be a mapping which is used to define the
     environment variables for the new process (they are used instead of
     the current process” environment); the functions *note spawnl():
     31b, *note spawnlp(): 30b6, *note spawnv(): 30b8, and *note
     spawnvp(): 30ba. all cause the new process to inherit the
     environment of the current process.  Note that keys and values in
     the 'env' dictionary must be strings; invalid keys or values will
     cause the function to fail, with a return value of ‘127’.

     As an example, the following calls to *note spawnlp(): 30b6. and
     *note spawnvpe(): 30bb. are equivalent:

          import os
          os.spawnlp(os.P_WAIT, 'cp', 'cp', 'index.html', '/dev/null')

          L = ['cp', 'index.html', '/dev/null']
          os.spawnvpe(os.P_WAIT, 'cp', L, os.environ)

     Raises an *note auditing event: 1c56. ‘os.spawn’ with arguments
     ‘mode’, ‘path’, ‘args’, ‘env’.

     *note Availability: 2128.: Unix, Windows, not WASI, not Android,
     not iOS.

     *note spawnlp(): 30b6, *note spawnlpe(): 30b7, *note spawnvp():
     30ba. and *note spawnvpe(): 30bb. are not available on Windows.
     *note spawnle(): 30b5. and *note spawnve(): 30b9. are not
     thread-safe on Windows; we advise you to use the *note subprocess:
     dc. module instead.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Deprecato dalla versione 3.14: These functions are *note soft
     deprecated: 23d. and should no longer be used to write new code.
     The *note subprocess: dc. module is recommended instead.

 -- Dati: os.P_NOWAIT
 -- Dati: os.P_NOWAITO

     Possible values for the 'mode' parameter to the *note spawn*: 31b.
     family of functions.  If either of these values is given, the *note
     spawn*: 31b. functions will return as soon as the new process has
     been created, with the process id as the return value.

     *note Availability: 2128.: Unix, Windows.

 -- Dati: os.P_WAIT

     Possible value for the 'mode' parameter to the *note spawn*: 31b.
     family of functions.  If this is given as 'mode', the *note spawn*:
     31b. functions will not return until the new process has run to
     completion and will return the exit code of the process the run is
     successful, or ‘-signal’ if a signal kills the process.

     *note Availability: 2128.: Unix, Windows.

 -- Dati: os.P_DETACH
 -- Dati: os.P_OVERLAY

     Possible values for the 'mode' parameter to the *note spawn*: 31b.
     family of functions.  These are less portable than those listed
     above.  *note P_DETACH: 30bf. is similar to *note P_NOWAIT: 30bc,
     but the new process is detached from the console of the calling
     process.  If *note P_OVERLAY: 30c0. is used, the current process
     will be replaced; the *note spawn*: 31b. function will not return.

     *note Availability: 2128.: Windows.

 -- Funzione: os.startfile (path[, operation][, arguments][, cwd][,
          show_cmd])

     Start a file with its associated application.

     When 'operation' is not specified, this acts like double-clicking
     the file in Windows Explorer, or giving the file name as an
     argument to the ‘start’ command from the interactive command shell:
     the file is opened with whatever application (if any) its extension
     is associated.

     When another 'operation' is given, it must be a «command verb» that
     specifies what should be done with the file.  Common verbs
     documented by Microsoft are ‘'open'’, ‘'print'’ and ‘'edit'’ (to be
     used on files) as well as ‘'explore'’ and ‘'find'’ (to be used on
     directories).

     When launching an application, specify 'arguments' to be passed as
     a single string.  This argument may have no effect when using this
     function to launch a document.

     The default working directory is inherited, but may be overridden
     by the 'cwd' argument.  This should be an absolute path.  A
     relative 'path' will be resolved against this argument.

     Use 'show_cmd' to override the default window style.  Whether this
     has any effect will depend on the application being launched.
     Values are integers as supported by the Win32 ‘ShellExecute()’
     function.

     *note startfile(): 1c6b. returns as soon as the associated
     application is launched.  There is no option to wait for the
     application to close, and no way to retrieve the application’s exit
     status.  The 'path' parameter is relative to the current directory
     or 'cwd'.  If you want to use an absolute path, make sure the first
     character is not a slash (‘'/'’) Use *note pathlib: a8. or the
     *note os.path.normpath(): 1521. function to ensure that paths are
     properly encoded for Win32.

     To reduce interpreter startup overhead, the Win32 ‘ShellExecute()’
     function is not resolved until this function is first called.  If
     the function cannot be resolved, *note NotImplementedError: 36b.
     will be raised.

     Raises an *note auditing event: 1c56. ‘os.startfile’ with arguments
     ‘path’, ‘operation’.

     Raises an *note auditing event: 1c56. ‘os.startfile/2’ with
     arguments ‘path’, ‘operation’, ‘arguments’, ‘cwd’, ‘show_cmd’.

     *note Availability: 2128.: Windows.

     Cambiato nella versione 3.10: Added the 'arguments', 'cwd' and
     'show_cmd' arguments, and the ‘os.startfile/2’ audit event.

 -- Funzione: os.system (command)

     Execute the command (a string) in a subshell.  This is implemented
     by calling the Standard C function ‘system()’, and has the same
     limitations.  Changes to *note sys.stdin: 760, etc.  are not
     reflected in the environment of the executed command.  If 'command'
     generates any output, it will be sent to the interpreter standard
     output stream.  The C standard does not specify the meaning of the
     return value of the C function, so the return value of the Python
     function is system-dependent.

     On Unix, the return value is the exit status of the process encoded
     in the format specified for *note wait(): f9a.

     On Windows, the return value is that returned by the system shell
     after running 'command'.  The shell is given by the Windows
     environment variable ‘COMSPEC’: it is usually ‘cmd.exe’, which
     returns the exit status of the command run; on systems using a
     non-native shell, consult your shell documentation.

     The *note subprocess: dc. module provides more powerful facilities
     for spawning new processes and retrieving their results; using that
     module is recommended to using this function.  See the *note
     Replacing Older Functions with the subprocess Module: 1390. section
     in the *note subprocess: dc. documentation for some helpful
     recipes.

     On Unix, *note waitstatus_to_exitcode(): b19. can be used to
     convert the result (exit status) into an exit code.  On Windows,
     the result is directly the exit code.

     Raises an *note auditing event: 1c56. ‘os.system’ with argument
     ‘command’.

     *note Availability: 2128.: Unix, Windows, not WASI, not Android,
     not iOS.

 -- Funzione: os.times ()

     Returns the current global process times.  The return value is an
     object with five attributes:

        * ‘user’ - user time

        * ‘system’ - system time

        * ‘children_user’ - user time of all child processes

        * ‘children_system’ - system time of all child processes

        * ‘elapsed’ - elapsed real time since a fixed point in the past

     For backwards compatibility, this object also behaves like a
     five-tuple containing ‘user’, ‘system’, ‘children_user’,
     ‘children_system’, and ‘elapsed’ in that order.

     See the Unix manual page ‘times(2)(5)’ and times(3)(6) manual page
     on Unix or the GetProcessTimes MSDN(7) on Windows.  On Windows,
     only ‘user’ and ‘system’ are known; the other attributes are zero.

     *note Availability: 2128.: Unix, Windows.

     Cambiato nella versione 3.3: Return type changed from a tuple to a
     tuple-like object with named attributes.

 -- Funzione: os.wait ()

     Wait for completion of a child process, and return a tuple
     containing its pid and exit status indication: a 16-bit number,
     whose low byte is the signal number that killed the process, and
     whose high byte is the exit status (if the signal number is zero);
     the high bit of the low byte is set if a core file was produced.

     If there are no children that could be waited for, *note
     ChildProcessError: 125a. is raised.

     *note waitstatus_to_exitcode(): b19. can be used to convert the
     exit status into an exit code.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

     Vedi anche
     ..........

     The other ‘wait*()’ functions documented below can be used to wait
     for the completion of a specific child process and have more
     options.  *note waitpid(): f9c. is the only one also available on
     Windows.

 -- Funzione: os.waitid (idtype, id, options, /)

     Wait for the completion of a child process.

     'idtype' can be *note P_PID: 30c1, *note P_PGID: 30c2, *note P_ALL:
     30c3, or (on Linux) *note P_PIDFD: b18.  The interpretation of 'id'
     depends on it; see their individual descriptions.

     'options' is an OR combination of flags.  At least one of *note
     WEXITED: 30c4, *note WSTOPPED: 30c5. or *note WCONTINUED: 30c6. is
     required; *note WNOHANG: 30c7. and *note WNOWAIT: 30c8. are
     additional optional flags.

     The return value is an object representing the data contained in
     the ‘siginfo_t’ structure with the following attributes:

        * ‘si_pid’ (process ID)

        * ‘si_uid’ (real user ID of the child)

        * ‘si_signo’ (always *note SIGCHLD: 30c9.)

        * ‘si_status’ (the exit status or signal number, depending on
          ‘si_code’)

        * ‘si_code’ (see *note CLD_EXITED: 30ca. for possible values)

     If *note WNOHANG: 30c7. is specified and there are no matching
     children in the requested state, ‘None’ is returned.  Otherwise, if
     there are no matching children that could be waited for, *note
     ChildProcessError: 125a. is raised.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

     Added in version 3.3.

     Cambiato nella versione 3.13: This function is now available on
     macOS as well.

 -- Funzione: os.waitpid (pid, options, /)

     The details of this function differ on Unix and Windows.

     On Unix: Wait for completion of a child process given by process id
     'pid', and return a tuple containing its process id and exit status
     indication (encoded as for *note wait(): f9a.).  The semantics of
     the call are affected by the value of the integer 'options', which
     should be ‘0’ for normal operation.

     If 'pid' is greater than ‘0’, *note waitpid(): f9c. requests status
     information for that specific process.  If 'pid' is ‘0’, the
     request is for the status of any child in the process group of the
     current process.  If 'pid' is ‘-1’, the request pertains to any
     child of the current process.  If 'pid' is less than ‘-1’, status
     is requested for any process in the process group ‘-pid’ (the
     absolute value of 'pid').

     'options' is an OR combination of flags.  If it contains *note
     WNOHANG: 30c7. and there are no matching children in the requested
     state, ‘(0, 0)’ is returned.  Otherwise, if there are no matching
     children that could be waited for, *note ChildProcessError: 125a.
     is raised.  Other options that can be used are *note WUNTRACED:
     30cb. and *note WCONTINUED: 30c6.

     On Windows: Wait for completion of a process given by process
     handle 'pid', and return a tuple containing 'pid', and its exit
     status shifted left by 8 bits (shifting makes cross-platform use of
     the function easier).  A 'pid' less than or equal to ‘0’ has no
     special meaning on Windows, and raises an exception.  The value of
     integer 'options' has no effect.  'pid' can refer to any process
     whose id is known, not necessarily a child process.  The *note
     spawn*: 31b. functions called with *note P_NOWAIT: 30bc. return
     suitable process handles.

     *note waitstatus_to_exitcode(): b19. can be used to convert the
     exit status into an exit code.

     *note Availability: 2128.: Unix, Windows, not WASI, not Android,
     not iOS.

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the function now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(8) for the
     rationale).

 -- Funzione: os.wait3 (options)

     Similar to *note waitpid(): f9c, except no process id argument is
     given and a 3-element tuple containing the child’s process id, exit
     status indication, and resource usage information is returned.
     Refer to *note resource.getrusage(): 1638. for details on resource
     usage information.  The 'options' argument is the same as that
     provided to *note waitpid(): f9c. and *note wait4(): f99.

     *note waitstatus_to_exitcode(): b19. can be used to convert the
     exit status into an exitcode.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Funzione: os.wait4 (pid, options)

     Similar to *note waitpid(): f9c, except a 3-element tuple,
     containing the child’s process id, exit status indication, and
     resource usage information is returned.  Refer to *note
     resource.getrusage(): 1638. for details on resource usage
     information.  The arguments to *note wait4(): f99. are the same as
     those provided to *note waitpid(): f9c.

     *note waitstatus_to_exitcode(): b19. can be used to convert the
     exit status into an exitcode.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Dati: os.P_PID
 -- Dati: os.P_PGID
 -- Dati: os.P_ALL
 -- Dati: os.P_PIDFD

     These are the possible values for 'idtype' in *note waitid(): f9b.
     They affect how 'id' is interpreted:

        * ‘P_PID’ - wait for the child whose PID is 'id'.

        * ‘P_PGID’ - wait for any child whose progress group ID is 'id'.

        * ‘P_ALL’ - wait for any child; 'id' is ignored.

        * ‘P_PIDFD’ - wait for the child identified by the file
          descriptor 'id' (a process file descriptor created with *note
          pidfd_open(): 6a5.).

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

          Nota: ‘P_PIDFD’ is only available on Linux >= 5.4.

     Added in version 3.3.

     Added in version 3.9: The ‘P_PIDFD’ constant.

 -- Dati: os.WCONTINUED

     This 'options' flag for *note waitpid(): f9c, *note wait3(): f98,
     *note wait4(): f99, and *note waitid(): f9b. causes child processes
     to be reported if they have been continued from a job control stop
     since they were last reported.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Dati: os.WEXITED

     This 'options' flag for *note waitid(): f9b. causes child processes
     that have terminated to be reported.

     The other ‘wait*’ functions always report children that have
     terminated, so this option is not available for them.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

     Added in version 3.3.

 -- Dati: os.WSTOPPED

     This 'options' flag for *note waitid(): f9b. causes child processes
     that have been stopped by the delivery of a signal to be reported.

     This option is not available for the other ‘wait*’ functions.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

     Added in version 3.3.

 -- Dati: os.WUNTRACED

     This 'options' flag for *note waitpid(): f9c, *note wait3(): f98,
     and *note wait4(): f99. causes child processes to also be reported
     if they have been stopped but their current state has not been
     reported since they were stopped.

     This option is not available for *note waitid(): f9b.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Dati: os.WNOHANG

     This 'options' flag causes *note waitpid(): f9c, *note wait3():
     f98, *note wait4(): f99, and *note waitid(): f9b. to return right
     away if no child process status is available immediately.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Dati: os.WNOWAIT

     This 'options' flag causes *note waitid(): f9b. to leave the child
     in a waitable state, so that a later ‘wait*()’ call can be used to
     retrieve the child status information again.

     This option is not available for the other ‘wait*’ functions.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Dati: os.CLD_EXITED
 -- Dati: os.CLD_KILLED
 -- Dati: os.CLD_DUMPED
 -- Dati: os.CLD_TRAPPED
 -- Dati: os.CLD_STOPPED
 -- Dati: os.CLD_CONTINUED

     These are the possible values for ‘si_code’ in the result returned
     by *note waitid(): f9b.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

     Added in version 3.3.

     Cambiato nella versione 3.9: Added *note CLD_KILLED: b16. and *note
     CLD_STOPPED: b17. values.

 -- Funzione: os.waitstatus_to_exitcode (status)

     Convert a wait status to an exit code.

     On Unix:

        * If the process exited normally (if ‘WIFEXITED(status)’ is
          true), return the process exit status (return
          ‘WEXITSTATUS(status)’): result greater than or equal to 0.

        * If the process was terminated by a signal (if
          ‘WIFSIGNALED(status)’ is true), return ‘-signum’ where
          'signum' is the number of the signal that caused the process
          to terminate (return ‘-WTERMSIG(status)’): result less than 0.

        * Otherwise, raise a *note ValueError: 2ec.

     On Windows, return 'status' shifted right by 8 bits.

     On Unix, if the process is being traced or if *note waitpid(): f9c.
     was called with *note WUNTRACED: 30cb. option, the caller must
     first check if ‘WIFSTOPPED(status)’ is true.  This function must
     not be called if ‘WIFSTOPPED(status)’ is true.

     Vedi anche
     ..........

     *note WIFEXITED(): 30cf, *note WEXITSTATUS(): 30d0, *note
     WIFSIGNALED(): 30d1, *note WTERMSIG(): 30d2, *note WIFSTOPPED():
     30d3, *note WSTOPSIG(): 30d4. functions.

     *note Availability: 2128.: Unix, Windows, not WASI, not Android,
     not iOS.

     Added in version 3.9.

The following functions take a process status code as returned by *note
system(): 1664, *note wait(): f9a, or *note waitpid(): f9c. as a
parameter.  They may be used to determine the disposition of a process.

 -- Funzione: os.WCOREDUMP (status, /)

     Return ‘True’ if a core dump was generated for the process,
     otherwise return ‘False’.

     This function should be employed only if *note WIFSIGNALED(): 30d1.
     is true.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Funzione: os.WIFCONTINUED (status)

     Return ‘True’ if a stopped child has been resumed by delivery of
     *note SIGCONT: 30d7. (if the process has been continued from a job
     control stop), otherwise return ‘False’.

     See *note WCONTINUED: 30c6. option.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Funzione: os.WIFSTOPPED (status)

     Return ‘True’ if the process was stopped by delivery of a signal,
     otherwise return ‘False’.

     *note WIFSTOPPED(): 30d3. only returns ‘True’ if the *note
     waitpid(): f9c. call was done using *note WUNTRACED: 30cb. option
     or when the process is being traced (see ‘ptrace(2)(9)’).

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Funzione: os.WIFSIGNALED (status)

     Return ‘True’ if the process was terminated by a signal, otherwise
     return ‘False’.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Funzione: os.WIFEXITED (status)

     Return ‘True’ if the process exited terminated normally, that is,
     by calling ‘exit()’ or ‘_exit()’, or by returning from ‘main()’;
     otherwise return ‘False’.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Funzione: os.WEXITSTATUS (status)

     Return the process exit status.

     This function should be employed only if *note WIFEXITED(): 30cf.
     is true.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Funzione: os.WSTOPSIG (status)

     Return the signal which caused the process to stop.

     This function should be employed only if *note WIFSTOPPED(): 30d3.
     is true.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

 -- Funzione: os.WTERMSIG (status)

     Return the number of the signal that caused the process to
     terminate.

     This function should be employed only if *note WIFSIGNALED(): 30d1.
     is true.

     *note Availability: 2128.: Unix, not WASI, not Android, not iOS.

   ---------- Footnotes ----------

   (1) https://msdn.microsoft.com/44228cf2-6306-466c-8f16-f513cd3ba8b5

   (2) https://discuss.python.org/t/33555

   (3) https://manpages.debian.org/pidfd_open(2)

   (4) https://manpages.debian.org/waitid(2)

   (5) https://manpages.debian.org/times(2)

   (6) https://man.freebsd.org/cgi/man.cgi?time(3)

   (7) 
https://docs.microsoft.com/windows/win32/api/processthreadsapi/nf-processthreadsapi-getprocesstimes

   (8) https://peps.python.org/pep-0475/

   (9) https://manpages.debian.org/ptrace(2)


File: python.info,  Node: Interface to the scheduler,  Next: Miscellaneous System Information,  Prev: Process Management,  Up: os — Miscellaneous operating system interfaces

5.16.1.12 Interface to the scheduler
....................................

These functions control how a process is allocated CPU time by the
operating system.  They are only available on some Unix platforms.  For
more detailed information, consult your Unix manpages.

Added in version 3.3.

The following scheduling policies are exposed if they are supported by
the operating system.

 -- Dati: os.SCHED_OTHER

     The default scheduling policy.

 -- Dati: os.SCHED_BATCH

     Scheduling policy for CPU-intensive processes that tries to
     preserve interactivity on the rest of the computer.

 -- Dati: os.SCHED_DEADLINE

     Scheduling policy for tasks with deadline constraints.

     Added in version 3.14.

 -- Dati: os.SCHED_IDLE

     Scheduling policy for extremely low priority background tasks.

 -- Dati: os.SCHED_NORMAL

     Alias for *note SCHED_OTHER: 30da.

     Added in version 3.14.

 -- Dati: os.SCHED_SPORADIC

     Scheduling policy for sporadic server programs.

 -- Dati: os.SCHED_FIFO

     A First In First Out scheduling policy.

 -- Dati: os.SCHED_RR

     A round-robin scheduling policy.

 -- Dati: os.SCHED_RESET_ON_FORK

     This flag can be OR’ed with any other scheduling policy.  When a
     process with this flag set forks, its child’s scheduling policy and
     priority are reset to the default.

 -- Classe: os.sched_param (sched_priority)

     This class represents tunable scheduling parameters used in *note
     sched_setparam(): 1317, *note sched_setscheduler(): 1318, and *note
     sched_getparam(): 1313.  It is immutable.

     At the moment, there is only one possible parameter:

      -- Attributo: sched_priority

          The scheduling priority for a scheduling policy.

 -- Funzione: os.sched_get_priority_min (policy)

     Get the minimum priority value for 'policy'.  'policy' is one of
     the scheduling policy constants above.

 -- Funzione: os.sched_get_priority_max (policy)

     Get the maximum priority value for 'policy'.  'policy' is one of
     the scheduling policy constants above.

 -- Funzione: os.sched_setscheduler (pid, policy, param, /)

     Set the scheduling policy for the process with PID 'pid'.  A 'pid'
     of 0 means the calling process.  'policy' is one of the scheduling
     policy constants above.  'param' is a *note sched_param: 18f8.
     instance.

 -- Funzione: os.sched_getscheduler (pid, /)

     Return the scheduling policy for the process with PID 'pid'.  A
     'pid' of 0 means the calling process.  The result is one of the
     scheduling policy constants above.

 -- Funzione: os.sched_setparam (pid, param, /)

     Set the scheduling parameters for the process with PID 'pid'.  A
     'pid' of 0 means the calling process.  'param' is a *note
     sched_param: 18f8. instance.

 -- Funzione: os.sched_getparam (pid, /)

     Return the scheduling parameters as a *note sched_param: 18f8.
     instance for the process with PID 'pid'.  A 'pid' of 0 means the
     calling process.

 -- Funzione: os.sched_rr_get_interval (pid, /)

     Return the round-robin quantum in seconds for the process with PID
     'pid'.  A 'pid' of 0 means the calling process.

 -- Funzione: os.sched_yield ()

     Voluntarily relinquish the CPU. See ‘sched_yield(2)(1)’ for
     details.

 -- Funzione: os.sched_setaffinity (pid, mask, /)

     Restrict the process with PID 'pid' (or the current process if
     zero) to a set of CPUs.  'mask' is an iterable of integers
     representing the set of CPUs to which the process should be
     restricted.

 -- Funzione: os.sched_getaffinity (pid, /)

     Return the set of CPUs the process with PID 'pid' is restricted to.

     If 'pid' is zero, return the set of CPUs the calling thread of the
     current process is restricted to.

     See also the *note process_cpu_count(): 4db. function.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/sched_yield(2)


File: python.info,  Node: Miscellaneous System Information,  Next: Random numbers<2>,  Prev: Interface to the scheduler,  Up: os — Miscellaneous operating system interfaces

5.16.1.13 Miscellaneous System Information
..........................................

 -- Funzione: os.confstr (name, /)

     Return string-valued system configuration values.  'name' specifies
     the configuration value to retrieve; it may be a string which is
     the name of a defined system value; these names are specified in a
     number of standards (POSIX, Unix 95, Unix 98, and others).  Some
     platforms define additional names as well.  The names known to the
     host operating system are given as the keys of the ‘confstr_names’
     dictionary.  For configuration variables not included in that
     mapping, passing an integer for 'name' is also accepted.

     If the configuration value specified by 'name' isn’t defined,
     ‘None’ is returned.

     If 'name' is a string and is not known, *note ValueError: 2ec. is
     raised.  If a specific value for 'name' is not supported by the
     host system, even if it is included in ‘confstr_names’, an *note
     OSError: 2c0. is raised with *note errno.EINVAL: 1dba. for the
     error number.

     *note Availability: 2128.: Unix.

 -- Dati: os.confstr_names

     Dictionary mapping names accepted by *note confstr(): 18d4. to the
     integer values defined for those names by the host operating
     system.  This can be used to determine the set of names known to
     the system.

     *note Availability: 2128.: Unix.

 -- Funzione: os.cpu_count ()

     Return the number of logical CPUs in the 'system'.  Returns ‘None’
     if undetermined.

     The *note process_cpu_count(): 4db. function can be used to get the
     number of logical CPUs usable by the calling thread of the 'current
     process'.

     Added in version 3.4.

     Cambiato nella versione 3.13: If *note -X cpu_count: 16f. is given
     or *note PYTHON_CPU_COUNT: 51f. is set, *note cpu_count(): 4dc.
     returns the override value 'n'.

 -- Funzione: os.getloadavg ()

     Return the number of processes in the system run queue averaged
     over the last 1, 5, and 15 minutes or raises *note OSError: 2c0. if
     the load average was unobtainable.

     *note Availability: 2128.: Unix.

 -- Funzione: os.process_cpu_count ()

     Get the number of logical CPUs usable by the calling thread of the
     'current process'.  Returns ‘None’ if undetermined.  It can be less
     than *note cpu_count(): 4dc. depending on the CPU affinity.

     The *note cpu_count(): 4dc. function can be used to get the number
     of logical CPUs in the 'system'.

     If *note -X cpu_count: 16f. is given or *note PYTHON_CPU_COUNT:
     51f. is set, *note process_cpu_count(): 4db. returns the override
     value 'n'.

     See also the *note sched_getaffinity(): 1312. function.

     Added in version 3.13.

 -- Funzione: os.sysconf (name, /)

     Return integer-valued system configuration values.  If the
     configuration value specified by 'name' isn’t defined, ‘-1’ is
     returned.  The comments regarding the 'name' parameter for *note
     confstr(): 18d4. apply here as well; the dictionary that provides
     information on the known names is given by ‘sysconf_names’.

     *note Availability: 2128.: Unix.

 -- Dati: os.sysconf_names

     Dictionary mapping names accepted by *note sysconf(): 18d5. to the
     integer values defined for those names by the host operating
     system.  This can be used to determine the set of names known to
     the system.

     *note Availability: 2128.: Unix.

     Cambiato nella versione 3.11: Add ‘'SC_MINSIGSTKSZ'’ name.

The following data values are used to support path manipulation
operations.  These are defined for all platforms.

Higher-level operations on pathnames are defined in the *note os.path:
a6. module.

 -- Dati: os.curdir

     The constant string used by the operating system to refer to the
     current directory.  This is ‘'.'’ for Windows and POSIX. Also
     available via *note os.path: a6.

 -- Dati: os.pardir

     The constant string used by the operating system to refer to the
     parent directory.  This is ‘'..'’ for Windows and POSIX. Also
     available via *note os.path: a6.

 -- Dati: os.sep

     The character used by the operating system to separate pathname
     components.  This is ‘'/'’ for POSIX and ‘'\\'’ for Windows.  Note
     that knowing this is not sufficient to be able to parse or
     concatenate pathnames — use *note os.path.split(): 2c37. and *note
     os.path.join(): 1991. — but it is occasionally useful.  Also
     available via *note os.path: a6.

 -- Dati: os.altsep

     An alternative character used by the operating system to separate
     pathname components, or ‘None’ if only one separator character
     exists.  This is set to ‘'/'’ on Windows systems where ‘sep’ is a
     backslash.  Also available via *note os.path: a6.

 -- Dati: os.extsep

     The character which separates the base filename from the extension;
     for example, the ‘'.'’ in ‘os.py’.  Also available via *note
     os.path: a6.

 -- Dati: os.pathsep

     The character conventionally used by the operating system to
     separate search path components (as in ‘PATH’), such as ‘':'’ for
     POSIX or ‘';'’ for Windows.  Also available via *note os.path: a6.

 -- Dati: os.defpath

     The default search path used by *note exec*p*: 3099. and *note
     spawn*p*: 31b. if the environment doesn’t have a ‘'PATH'’ key.
     Also available via *note os.path: a6.

 -- Dati: os.linesep

     The string used to separate (or, rather, terminate) lines on the
     current platform.  This may be a single character, such as ‘'\n'’
     for POSIX, or multiple characters, for example, ‘'\r\n'’ for
     Windows.  Do not use 'os.linesep' as a line terminator when writing
     files opened in text mode (the default); use a single ‘'\n'’
     instead, on all platforms.

 -- Dati: os.devnull

     The file path of the null device.  For example: ‘'/dev/null'’ for
     POSIX, ‘'nul'’ for Windows.  Also available via *note os.path: a6.

 -- Dati: os.RTLD_LAZY
 -- Dati: os.RTLD_NOW
 -- Dati: os.RTLD_GLOBAL
 -- Dati: os.RTLD_LOCAL
 -- Dati: os.RTLD_NODELETE
 -- Dati: os.RTLD_NOLOAD
 -- Dati: os.RTLD_DEEPBIND

     Flags for use with the *note setdlopenflags(): 1327. and *note
     getdlopenflags(): 1715. functions.  See the Unix manual page
     ‘dlopen(3)(1)’ for what the different flags mean.

     Added in version 3.3.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/dlopen(3)


File: python.info,  Node: Random numbers<2>,  Prev: Miscellaneous System Information,  Up: os — Miscellaneous operating system interfaces

5.16.1.14 Random numbers
........................

 -- Funzione: os.getrandom (size, flags=0)

     Get up to 'size' random bytes.  The function can return less bytes
     than requested.

     These bytes can be used to seed user-space random number generators
     or for cryptographic purposes.

     ‘getrandom()’ relies on entropy gathered from device drivers and
     other sources of environmental noise.  Unnecessarily reading large
     quantities of data will have a negative impact on other users of
     the ‘/dev/random’ and ‘/dev/urandom’ devices.

     The flags argument is a bit mask that can contain zero or more of
     the following values ORed together: *note os.GRND_RANDOM: 30e8. and
     *note GRND_NONBLOCK: 30e9.

     See also the Linux getrandom() manual page(1).

     *note Availability: 2128.: Linux >= 3.17.

     Added in version 3.6.

 -- Funzione: os.urandom (size, /)

     Return a bytestring of 'size' random bytes suitable for
     cryptographic use.

     This function returns random bytes from an OS-specific randomness
     source.  The returned data should be unpredictable enough for
     cryptographic applications, though its exact quality depends on the
     OS implementation.

     On Linux, if the ‘getrandom()’ syscall is available, it is used in
     blocking mode: block until the system urandom entropy pool is
     initialized (128 bits of entropy are collected by the kernel).  See
     the PEP 524(2) for the rationale.  On Linux, the *note getrandom():
     ebb. function can be used to get random bytes in non-blocking mode
     (using the *note GRND_NONBLOCK: 30e9. flag) or to poll until the
     system urandom entropy pool is initialized.

     On a Unix-like system, random bytes are read from the
     ‘/dev/urandom’ device.  If the ‘/dev/urandom’ device is not
     available or not readable, the *note NotImplementedError: 36b.
     exception is raised.

     On Windows, it will use ‘BCryptGenRandom()’.

     Vedi anche
     ..........

     The *note secrets: c5. module provides higher level functions.  For
     an easy-to-use interface to the random number generator provided by
     your platform, please see *note random.SystemRandom: 2b3d.

     Cambiato nella versione 3.5: On Linux 3.17 and newer, the
     ‘getrandom()’ syscall is now used when available.  On OpenBSD 5.6
     and newer, the C ‘getentropy()’ function is now used.  These
     functions avoid the usage of an internal file descriptor.

     Cambiato nella versione 3.5.2: On Linux, if the ‘getrandom()’
     syscall blocks (the urandom entropy pool is not initialized yet),
     fall back on reading ‘/dev/urandom’.

     Cambiato nella versione 3.6: On Linux, ‘getrandom()’ is now used in
     blocking mode to increase the security.

     Cambiato nella versione 3.11: On Windows, ‘BCryptGenRandom()’ is
     used instead of ‘CryptGenRandom()’ which is deprecated.

 -- Dati: os.GRND_NONBLOCK

     By default, when reading from ‘/dev/random’, *note getrandom():
     ebb. blocks if no random bytes are available, and when reading from
     ‘/dev/urandom’, it blocks if the entropy pool has not yet been
     initialized.

     If the *note GRND_NONBLOCK: 30e9. flag is set, then *note
     getrandom(): ebb. does not block in these cases, but instead
     immediately raises *note BlockingIOError: 235.

     Added in version 3.6.

 -- Dati: os.GRND_RANDOM

     If this bit is set, then random bytes are drawn from the
     ‘/dev/random’ pool instead of the ‘/dev/urandom’ pool.

     Added in version 3.6.

   ---------- Footnotes ----------

   (1) https://man7.org/linux/man-pages/man2/getrandom.2.html

   (2) https://peps.python.org/pep-0524/


File: python.info,  Node: io — Core tools for working with streams,  Next: time — Time access and conversions,  Prev: os — Miscellaneous operating system interfaces,  Up: Generic Operating System Services

5.16.2 ‘io’ — Core tools for working with streams
-------------------------------------------------

'Source code:' Lib/io.py(1)

__________________________________________________________________

* Menu:

* Overview: Overview<2>.
* Text Encoding::
* High-level Module Interface::
* Class hierarchy::
* Static Typing::
* Performance: Performance<3>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/io.py


File: python.info,  Node: Overview<2>,  Next: Text Encoding,  Up: io — Core tools for working with streams

5.16.2.1 Overview
.................

The *note io: 83. module provides Python’s main facilities for dealing
with various types of I/O. There are three main types of I/O: 'text
I/O', 'binary I/O' and 'raw I/O'. These are generic categories, and
various backing stores can be used for each of them.  A concrete object
belonging to any of these categories is called a *note file object:
13cb.  Other common terms are 'stream' and 'file-like object'.

Independent of its category, each concrete stream object will also have
various capabilities: it can be read-only, write-only, or read-write.
It can also allow arbitrary random access (seeking forwards or backwards
to any location), or only sequential access (for example in the case of
a socket or pipe).

All streams are careful about the type of data you give to them.  For
example giving a *note str: 169. object to the ‘write()’ method of a
binary stream will raise a *note TypeError: 198.  So will giving a *note
bytes: 192. object to the ‘write()’ method of a text stream.

Cambiato nella versione 3.3: Operations that used to raise *note
IOError: 1255. now raise *note OSError: 2c0, since *note IOError: 1255.
is now an alias of *note OSError: 2c0.

* Menu:

* Text I/O::
* Binary I/O::
* Raw I/O::


File: python.info,  Node: Text I/O,  Next: Binary I/O,  Up: Overview<2>

5.16.2.2 Text I/O
.................

Text I/O expects and produces *note str: 169. objects.  This means that
whenever the backing store is natively made of bytes (such as in the
case of a file), encoding and decoding of data is made transparently as
well as optional translation of platform-specific newline characters.

The easiest way to create a text stream is with *note open(): 316,
optionally specifying an encoding:

     f = open("myfile.txt", "r", encoding="utf-8")

In-memory text streams are also available as *note StringIO: 112b.
objects:

     f = io.StringIO("some initial text data")

     Nota: When working with a non-blocking stream, be aware that read
     operations on text I/O objects might raise a *note BlockingIOError:
     235. if the stream cannot perform the operation immediately.

The text stream API is described in detail in the documentation of *note
TextIOBase: 8a5.


File: python.info,  Node: Binary I/O,  Next: Raw I/O,  Prev: Text I/O,  Up: Overview<2>

5.16.2.3 Binary I/O
...................

Binary I/O (also called 'buffered I/O') expects *note bytes-like
objects: 193. and produces *note bytes: 192. objects.  No encoding,
decoding, or newline translation is performed.  This category of streams
can be used for all kinds of non-text data, and also when manual control
over the handling of text data is desired.

The easiest way to create a binary stream is with *note open(): 316.
with ‘'b'’ in the mode string:

     f = open("myfile.jpg", "rb")

In-memory binary streams are also available as *note BytesIO: 10a6.
objects:

     f = io.BytesIO(b"some initial binary data: \x00\x01")

The binary stream API is described in detail in the docs of *note
BufferedIOBase: 8a4.

Other library modules may provide additional ways to create text or
binary streams.  See *note socket.socket.makefile(): 13a7. for example.


File: python.info,  Node: Raw I/O,  Prev: Binary I/O,  Up: Overview<2>

5.16.2.4 Raw I/O
................

Raw I/O (also called 'unbuffered I/O') is generally used as a low-level
building-block for binary and text streams; it is rarely useful to
directly manipulate a raw stream from user code.  Nevertheless, you can
create a raw stream by opening a file in binary mode with buffering
disabled:

     f = open("myfile.jpg", "rb", buffering=0)

The raw stream API is described in detail in the docs of *note
RawIOBase: 12d8.


File: python.info,  Node: Text Encoding,  Next: High-level Module Interface,  Prev: Overview<2>,  Up: io — Core tools for working with streams

5.16.2.5 Text Encoding
......................

The default encoding of *note TextIOWrapper: 9c0. and *note open(): 316.
is locale-specific (*note locale.getencoding(): 329.).

However, many developers forget to specify the encoding when opening
text files encoded in UTF-8 (e.g.  JSON, TOML, Markdown, etc…) since
most Unix platforms use UTF-8 locale by default.  This causes bugs
because the locale encoding is not UTF-8 for most Windows users.  For
example:

     # May not work on Windows when non-ASCII characters in the file.
     with open("README.md") as f:
         long_description = f.read()

Accordingly, it is highly recommended that you specify the encoding
explicitly when opening text files.  If you want to use UTF-8, pass
‘encoding="utf-8"’.  To use the current locale encoding,
‘encoding="locale"’ is supported since Python 3.10.

Vedi anche
..........

*note Python UTF-8 Mode: 867.

     Python UTF-8 Mode can be used to change the default encoding to
     UTF-8 from locale-specific encoding.

PEP 686(1)

     Python 3.15 will make *note Python UTF-8 Mode: 867. default.

* Menu:

* Opt-in EncodingWarning::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0686/


File: python.info,  Node: Opt-in EncodingWarning,  Up: Text Encoding

5.16.2.6 Opt-in EncodingWarning
...............................

Added in version 3.10: See PEP 597(1) for more details.

To find where the default locale encoding is used, you can enable the
*note -X warn_default_encoding: 16f. command line option or set the
*note PYTHONWARNDEFAULTENCODING: 9c1. environment variable, which will
emit an *note EncodingWarning: 2117. when the default encoding is used.

If you are providing an API that uses *note open(): 316. or *note
TextIOWrapper: 9c0. and passes ‘encoding=None’ as a parameter, you can
use *note text_encoding(): 1a24. so that callers of the API will emit an
*note EncodingWarning: 2117. if they don’t pass an ‘encoding’.  However,
please consider using UTF-8 by default (i.e.  ‘encoding="utf-8"’) for
new APIs.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0597/


File: python.info,  Node: High-level Module Interface,  Next: Class hierarchy,  Prev: Text Encoding,  Up: io — Core tools for working with streams

5.16.2.7 High-level Module Interface
....................................

 -- Dati: io.DEFAULT_BUFFER_SIZE

     An int containing the default buffer size used by the module’s
     buffered I/O classes.  *note open(): 316. uses the file’s blksize
     (as obtained by *note os.stat(): 26d.) if possible.

 -- Funzione: io.open (file, mode='r', buffering=-1, encoding=None,
          errors=None, newline=None, closefd=True, opener=None)

     This is an alias for the builtin *note open(): 316. function.

     This function raises an *note auditing event: 1c56. ‘open’ with
     arguments 'path', 'mode' and 'flags'.  The 'mode' and 'flags'
     arguments may have been modified or inferred from the original
     call.

 -- Funzione: io.open_code (path)

     Opens the provided file with mode ‘'rb'’.  This function should be
     used when the intent is to treat the contents as executable code.

     'path' should be a *note str: 169. and an absolute path.

     The behavior of this function may be overridden by an earlier call
     to the *note PyFile_SetOpenCodeHook(): 1a82.  However, assuming
     that 'path' is a *note str: 169. and an absolute path,
     ‘open_code(path)’ should always behave the same as ‘open(path,
     'rb')’.  Overriding the behavior is intended for additional
     validation or preprocessing of the file.

     Added in version 3.8.

 -- Funzione: io.text_encoding (encoding, stacklevel=2, /)

     This is a helper function for callables that use *note open(): 316.
     or *note TextIOWrapper: 9c0. and have an ‘encoding=None’ parameter.

     This function returns 'encoding' if it is not ‘None’.  Otherwise,
     it returns ‘"locale"’ or ‘"utf-8"’ depending on *note UTF-8 Mode:
     867.

     This function emits an *note EncodingWarning: 2117. if *note
     sys.flags.warn_default_encoding: 89d. is true and 'encoding' is
     ‘None’.  'stacklevel' specifies where the warning is emitted.  For
     example:

          def read_text(path, encoding=None):
              encoding = io.text_encoding(encoding)  # stacklevel=2
              with open(path, encoding) as f:
                  return f.read()

     In this example, an *note EncodingWarning: 2117. is emitted for the
     caller of ‘read_text()’.

     See *note Text Encoding: 9c2. for more information.

     Added in version 3.10.

     Cambiato nella versione 3.11: *note text_encoding(): 1a24. returns
     «utf-8» when UTF-8 mode is enabled and 'encoding' is ‘None’.

 -- Eccezione: io.BlockingIOError

     This is a compatibility alias for the builtin *note
     BlockingIOError: 235. exception.

 -- Eccezione: io.UnsupportedOperation

     An exception inheriting *note OSError: 2c0. and *note ValueError:
     2ec. that is raised when an unsupported operation is called on a
     stream.

Vedi anche
..........

*note sys: df.

     contains the standard IO streams: *note sys.stdin: 760, *note
     sys.stdout: ccf, and *note sys.stderr: b35.


File: python.info,  Node: Class hierarchy,  Next: Static Typing,  Prev: High-level Module Interface,  Up: io — Core tools for working with streams

5.16.2.8 Class hierarchy
........................

The implementation of I/O streams is organized as a hierarchy of
classes.  First *note abstract base classes: 13be. (ABCs), which are
used to specify the various categories of streams, then concrete classes
providing the standard stream implementations.

     Nota: The abstract base classes also provide default
     implementations of some methods in order to help implementation of
     concrete stream classes.  For example, *note BufferedIOBase: 8a4.
     provides unoptimized implementations of ‘readinto()’ and
     ‘readline()’.

At the top of the I/O hierarchy is the abstract base class *note IOBase:
506.  It defines the basic interface to a stream.  Note, however, that
there is no separation between reading and writing to streams;
implementations are allowed to raise *note UnsupportedOperation: 1d67.
if they do not support a given operation.

The *note RawIOBase: 12d8. ABC extends *note IOBase: 506.  It deals with
the reading and writing of bytes to a stream.  *note FileIO: 1517.
subclasses *note RawIOBase: 12d8. to provide an interface to files in
the machine’s file system.

The *note BufferedIOBase: 8a4. ABC extends *note IOBase: 506.  It deals
with buffering on a raw binary stream (*note RawIOBase: 12d8.).  Its
subclasses, *note BufferedWriter: 15b9, *note BufferedReader: 1416, and
*note BufferedRWPair: 15bb. buffer raw binary streams that are writable,
readable, and both readable and writable, respectively.  *note
BufferedRandom: 15ba. provides a buffered interface to seekable streams.
Another *note BufferedIOBase: 8a4. subclass, *note BytesIO: 10a6, is a
stream of in-memory bytes.

The *note TextIOBase: 8a5. ABC extends *note IOBase: 506.  It deals with
streams whose bytes represent text, and handles encoding and decoding to
and from strings.  *note TextIOWrapper: 9c0, which extends *note
TextIOBase: 8a5, is a buffered text interface to a buffered raw stream
(*note BufferedIOBase: 8a4.).  Finally, *note StringIO: 112b. is an
in-memory stream for text.

Argument names are not part of the specification, and only the arguments
of *note open(): 316. are intended to be used as keyword arguments.

The following table summarizes the ABCs provided by the *note io: 83.
module:

ABC                           Inherits               Stub Methods                 Mixin Methods and Properties
                                                                                  
-----------------------------------------------------------------------------------------------------------------------------------------
                                                                                  
*note IOBase: 506.                                   ‘fileno’, ‘seek’, and        ‘close’, ‘closed’, ‘__enter__’, ‘__exit__’, ‘flush’,
                                                     ‘truncate’                   ‘isatty’, ‘__iter__’, ‘__next__’, ‘readable’,
                                                                                  ‘readline’, ‘readlines’, ‘seekable’, ‘tell’,
                                                                                  ‘writable’, and ‘writelines’
                                                                                  
                                                                                  
*note RawIOBase: 12d8.        *note IOBase: 506.     ‘readinto’ and ‘write’       Inherited *note IOBase: 506. methods, ‘read’, and
                                                                                  ‘readall’
                                                                                  
                                                                                  
*note BufferedIOBase: 8a4.    *note IOBase: 506.     ‘detach’, ‘read’, ‘read1’,   Inherited *note IOBase: 506. methods, ‘readinto’,
                                                     and ‘write’                  and ‘readinto1’
                                                                                  
                                                                                  
*note TextIOBase: 8a5.        *note IOBase: 506.     ‘detach’, ‘read’,            Inherited *note IOBase: 506. methods, ‘encoding’,
                                                     ‘readline’, and ‘write’      ‘errors’, and ‘newlines’
                                                                                  

* Menu:

* I/O Base Classes::
* Raw File I/O::
* Buffered Streams::
* Text I/O: Text I/O<2>.


File: python.info,  Node: I/O Base Classes,  Next: Raw File I/O,  Up: Class hierarchy

5.16.2.9 I/O Base Classes
.........................

 -- Classe: io.IOBase

     The abstract base class for all I/O classes.

     This class provides empty abstract implementations for many methods
     that derived classes can override selectively; the default
     implementations represent a file that cannot be read, written or
     seeked.

     Even though *note IOBase: 506. does not declare ‘read()’ or
     ‘write()’ because their signatures will vary, implementations and
     clients should consider those methods part of the interface.  Also,
     implementations may raise a *note ValueError: 2ec. (or *note
     UnsupportedOperation: 1d67.) when operations they do not support
     are called.

     The basic type used for binary data read from or written to a file
     is *note bytes: 192.  Other *note bytes-like objects: 193. are
     accepted as method arguments too.  Text I/O classes work with *note
     str: 169. data.

     Note that calling any method (even inquiries) on a closed stream is
     undefined.  Implementations may raise *note ValueError: 2ec. in
     this case.

     *note IOBase: 506. (and its subclasses) supports the iterator
     protocol, meaning that an *note IOBase: 506. object can be iterated
     over yielding the lines in a stream.  Lines are defined slightly
     differently depending on whether the stream is a binary stream
     (yielding bytes), or a text stream (yielding character strings).
     See *note readline(): 1531. below.

     *note IOBase: 506. is also a context manager and therefore supports
     the *note with: 186. statement.  In this example, 'file' is closed
     after the ‘with’ statement’s suite is finished—even if an exception
     occurs:

          with open('spam.txt', 'w') as file:
              file.write('Spam and eggs!')

     *note IOBase: 506. provides these data attributes and methods:

      -- Metodo: close ()

          Flush and close this stream.  This method has no effect if the
          file is already closed.  Once the file is closed, any
          operation on the file (e.g.  reading or writing) will raise a
          *note ValueError: 2ec.

          As a convenience, it is allowed to call this method more than
          once; only the first call, however, will have an effect.

      -- Attributo: closed

          ‘True’ if the stream is closed.

      -- Metodo: fileno ()

          Return the underlying file descriptor (an integer) of the
          stream if it exists.  An *note OSError: 2c0. is raised if the
          IO object does not use a file descriptor.

      -- Metodo: flush ()

          Flush the write buffers of the stream if applicable.  This
          does nothing for read-only and non-blocking streams.

      -- Metodo: isatty ()

          Return ‘True’ if the stream is interactive (i.e., connected to
          a terminal/tty device).

      -- Metodo: readable ()

          Return ‘True’ if the stream can be read from.  If ‘False’,
          ‘read()’ will raise *note OSError: 2c0.

      -- Metodo: readline (size=-1, /)

          Read and return one line from the stream.  If 'size' is
          specified, at most 'size' bytes will be read.

          The line terminator is always ‘b'\n'’ for binary files; for
          text files, the 'newline' argument to *note open(): 316. can
          be used to select the line terminator(s) recognized.

      -- Metodo: readlines (hint=-1, /)

          Read and return a list of lines from the stream.  'hint' can
          be specified to control the number of lines read: no more
          lines will be read if the total size (in bytes/characters) of
          all lines so far exceeds 'hint'.

          'hint' values of ‘0’ or less, as well as ‘None’, are treated
          as no hint.

          Note that it’s already possible to iterate on file objects
          using ‘for line in file: ...’ without calling
          ‘file.readlines()’.

      -- Metodo: seek (offset, whence=os.SEEK_SET, /)

          Change the stream position to the given byte 'offset',
          interpreted relative to the position indicated by 'whence',
          and return the new absolute position.  Values for 'whence'
          are:

             * *note os.SEEK_SET: 1495. or ‘0’ – start of the stream
               (the default); 'offset' should be zero or positive

             * *note os.SEEK_CUR: 1496. or ‘1’ – current stream
               position; 'offset' may be negative

             * *note os.SEEK_END: 1497. or ‘2’ – end of the stream;
               'offset' is usually negative

          Added in version 3.1: The ‘SEEK_*’ constants.

          Added in version 3.3: Some operating systems could support
          additional values, like *note os.SEEK_HOLE: 3026. or *note
          os.SEEK_DATA: 3027.  The valid values for a file could depend
          on it being open in text or binary mode.

      -- Metodo: seekable ()

          Return ‘True’ if the stream supports random access.  If
          ‘False’, *note seek(): 1494, *note tell(): 15b4. and *note
          truncate(): 1518. will raise *note OSError: 2c0.

      -- Metodo: tell ()

          Return the current stream position.

      -- Metodo: truncate (size=None, /)

          Resize the stream to the given 'size' in bytes (or the current
          position if 'size' is not specified).  The current stream
          position isn’t changed.  This resizing can extend or reduce
          the current file size.  In case of extension, the contents of
          the new file area depend on the platform (on most systems,
          additional bytes are zero-filled).  The new file size is
          returned.

          Cambiato nella versione 3.5: Windows will now zero-fill files
          when extending.

      -- Metodo: writable ()

          Return ‘True’ if the stream supports writing.  If ‘False’,
          ‘write()’ and *note truncate(): 1518. will raise *note
          OSError: 2c0.

      -- Metodo: writelines (lines, /)

          Write a list of lines to the stream.  Line separators are not
          added, so it is usual for each of the lines provided to have a
          line separator at the end.

      -- Metodo: __del__ ()

          Prepare for object destruction.  *note IOBase: 506. provides a
          default implementation of this method that calls the
          instance’s *note close(): 507. method.

 -- Classe: io.RawIOBase

     Base class for raw binary streams.  It inherits from *note IOBase:
     506.

     Raw binary streams typically provide low-level access to an
     underlying OS device or API, and do not try to encapsulate it in
     high-level primitives (this functionality is done at a higher-level
     in buffered binary streams and text streams, described later in
     this page).

     *note RawIOBase: 12d8. provides these methods in addition to those
     from *note IOBase: 506.:

      -- Metodo: read (size=-1, /)

          Read up to 'size' bytes from the object and return them.  As a
          convenience, if 'size' is unspecified or -1, all bytes until
          EOF are returned.  Otherwise, only one system call is ever
          made.  Fewer than 'size' bytes may be returned if the
          operating system call returns fewer than 'size' bytes.

          If 0 bytes are returned, and 'size' was not 0, this indicates
          end of file.  If the object is in non-blocking mode and no
          bytes are available, ‘None’ is returned.

          The default implementation defers to *note readall(): 30f8.
          and *note readinto(): 1020.

      -- Metodo: readall ()

          Read and return all the bytes from the stream until EOF, using
          multiple calls to the stream if necessary.

      -- Metodo: readinto (b, /)

          Read bytes into a pre-allocated, writable *note bytes-like
          object: 193. 'b', and return the number of bytes read.  For
          example, 'b' might be a *note bytearray: 344.  If the object
          is in non-blocking mode and no bytes are available, ‘None’ is
          returned.

      -- Metodo: write (b, /)

          Write the given *note bytes-like object: 193, 'b', to the
          underlying raw stream, and return the number of bytes written.
          This can be less than the length of 'b' in bytes, depending on
          specifics of the underlying raw stream, and especially if it
          is in non-blocking mode.  ‘None’ is returned if the raw stream
          is set not to block and no single byte could be readily
          written to it.  The caller may release or mutate 'b' after
          this method returns, so the implementation should only access
          'b' during the method call.

 -- Classe: io.BufferedIOBase

     Base class for binary streams that support some kind of buffering.
     It inherits from *note IOBase: 506.

     The main difference with *note RawIOBase: 12d8. is that methods
     *note read(): 1530, *note readinto(): 187d. and *note write(): ed9.
     will try (respectively) to read as much input as requested or to
     emit all provided data.

     In addition, if the underlying raw stream is in non-blocking mode,
     when the system returns would block *note write(): ed9. will raise
     *note BlockingIOError: 235. with *note
     BlockingIOError.characters_written: 26e4. and *note read(): 1530.
     will return data read so far or ‘None’ if no data is available.

     Besides, the *note read(): 1530. method does not have a default
     implementation that defers to *note readinto(): 187d.

     A typical *note BufferedIOBase: 8a4. implementation should not
     inherit from a *note RawIOBase: 12d8. implementation, but wrap one,
     like *note BufferedWriter: 15b9. and *note BufferedReader: 1416.
     do.

     *note BufferedIOBase: 8a4. provides or overrides these data
     attributes and methods in addition to those from *note IOBase:
     506.:

      -- Attributo: raw

          The underlying raw stream (a *note RawIOBase: 12d8. instance)
          that *note BufferedIOBase: 8a4. deals with.  This is not part
          of the *note BufferedIOBase: 8a4. API and may not exist on
          some implementations.

      -- Metodo: detach ()

          Separate the underlying raw stream from the buffer and return
          it.

          After the raw stream has been detached, the buffer is in an
          unusable state.

          Some buffers, like *note BytesIO: 10a6, do not have the
          concept of a single raw stream to return from this method.
          They raise *note UnsupportedOperation: 1d67.

          Added in version 3.1.

      -- Metodo: read (size=-1, /)

          Read and return up to 'size' bytes.  If the argument is
          omitted, ‘None’, or negative read as much as possible.

          Fewer bytes may be returned than requested.  An empty *note
          bytes: 192. object is returned if the stream is already at
          EOF.  More than one read may be made and calls may be retried
          if specific errors are encountered, see *note os.read(): f97.
          and PEP 475(1) for more details.  Less than size bytes being
          returned does not imply that EOF is imminent.

          When reading as much as possible the default implementation
          will use ‘raw.readall’ if available (which should implement
          *note RawIOBase.readall(): 30f8.), otherwise will read in a
          loop until read returns ‘None’, an empty *note bytes: 192, or
          a non-retryable error.  For most streams this is to EOF, but
          for non-blocking streams more data may become available.

               Nota: When the underlying raw stream is non-blocking,
               implementations may either raise *note BlockingIOError:
               235. or return ‘None’ if no data is available.  *note io:
               83. implementations return ‘None’.

      -- Metodo: read1 (size=-1, /)

          Read and return up to 'size' bytes, calling *note readinto():
          1020. which may retry if *note EINTR: f89. is encountered per
          PEP 475(2).  If 'size' is ‘-1’ or not provided, the
          implementation will choose an arbitrary value for 'size'.

               Nota: When the underlying raw stream is non-blocking,
               implementations may either raise *note BlockingIOError:
               235. or return ‘None’ if no data is available.  *note io:
               83. implementations return ‘None’.

      -- Metodo: readinto (b, /)

          Read bytes into a pre-allocated, writable *note bytes-like
          object: 193. 'b' and return the number of bytes read.  For
          example, 'b' might be a *note bytearray: 344.

          Like *note read(): 1530, multiple reads may be issued to the
          underlying raw stream, unless the latter is interactive.

          A *note BlockingIOError: 235. is raised if the underlying raw
          stream is in non blocking-mode, and has no data available at
          the moment.

      -- Metodo: readinto1 (b, /)

          Read bytes into a pre-allocated, writable *note bytes-like
          object: 193. 'b', using at most one call to the underlying raw
          stream’s *note read(): 101f. (or *note readinto(): 1020.)
          method.  Return the number of bytes read.

          A *note BlockingIOError: 235. is raised if the underlying raw
          stream is in non blocking-mode, and has no data available at
          the moment.

          Added in version 3.5.

      -- Metodo: write (b, /)

          Write the given *note bytes-like object: 193, 'b', and return
          the number of bytes written (always equal to the length of 'b'
          in bytes, since if the write fails an *note OSError: 2c0. will
          be raised).  Depending on the actual implementation, these
          bytes may be readily written to the underlying stream, or held
          in a buffer for performance and latency reasons.

          When in non-blocking mode, a *note BlockingIOError: 235. is
          raised if the data needed to be written to the raw stream but
          it couldn’t accept all the data without blocking.

          The caller may release or mutate 'b' after this method
          returns, so the implementation should only access 'b' during
          the method call.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0475/

   (2) https://peps.python.org/pep-0475/


File: python.info,  Node: Raw File I/O,  Next: Buffered Streams,  Prev: I/O Base Classes,  Up: Class hierarchy

5.16.2.10 Raw File I/O
......................

 -- Classe: io.FileIO (name, mode='r', closefd=True, opener=None)

     A raw binary stream representing an OS-level file containing bytes
     data.  It inherits from *note RawIOBase: 12d8.

     The 'name' can be one of two things:

        * a character string or *note bytes: 192. object representing
          the path to the file which will be opened.  In this case
          closefd must be ‘True’ (the default) otherwise an error will
          be raised.

        * an integer representing the number of an existing OS-level
          file descriptor to which the resulting *note FileIO: 1517.
          object will give access.  When the FileIO object is closed
          this fd will be closed as well, unless 'closefd' is set to
          ‘False’.

     The 'mode' can be ‘'r'’, ‘'w'’, ‘'x'’ or ‘'a'’ for reading
     (default), writing, exclusive creation or appending.  The file will
     be created if it doesn’t exist when opened for writing or
     appending; it will be truncated when opened for writing.  *note
     FileExistsError: 1222. will be raised if it already exists when
     opened for creating.  Opening a file for creating implies writing,
     so this mode behaves in a similar way to ‘'w'’.  Add a ‘'+'’ to the
     mode to allow simultaneous reading and writing.

     The *note read(): 101f. (when called with a positive argument),
     *note readinto(): 1020. and *note write(): 15b3. methods on this
     class will only make one system call.

     A custom opener can be used by passing a callable as 'opener'.  The
     underlying file descriptor for the file object is then obtained by
     calling 'opener' with ('name', 'flags').  'opener' must return an
     open file descriptor (passing *note os.open: f94. as 'opener'
     results in functionality similar to passing ‘None’).

     The newly created file is *note non-inheritable: 10fe.

     See the *note open(): 316. built-in function for examples on using
     the 'opener' parameter.

     Cambiato nella versione 3.3: The 'opener' parameter was added.  The
     ‘'x'’ mode was added.

     Cambiato nella versione 3.4: The file is now non-inheritable.

     *note FileIO: 1517. provides these data attributes in addition to
     those from *note RawIOBase: 12d8. and *note IOBase: 506.:

      -- Attributo: mode

          The mode as given in the constructor.

      -- Attributo: name

          The file name.  This is the file descriptor of the file when
          no name is given in the constructor.


File: python.info,  Node: Buffered Streams,  Next: Text I/O<2>,  Prev: Raw File I/O,  Up: Class hierarchy

5.16.2.11 Buffered Streams
..........................

Buffered I/O streams provide a higher-level interface to an I/O device
than raw I/O does.

 -- Classe: io.BytesIO (initial_bytes=b'')

     A binary stream using an in-memory bytes buffer.  It inherits from
     *note BufferedIOBase: 8a4.  The buffer is discarded when the *note
     close(): 507. method is called.

     The optional argument 'initial_bytes' is a *note bytes-like object:
     193. that contains initial data.

     *note BytesIO: 10a6. provides or overrides these methods in
     addition to those from *note BufferedIOBase: 8a4. and *note IOBase:
     506.:

      -- Metodo: getbuffer ()

          Return a readable and writable view over the contents of the
          buffer without copying them.  Also, mutating the view will
          transparently update the contents of the buffer:

               >>> b = io.BytesIO(b"abcdef")
               >>> view = b.getbuffer()
               >>> view[2:4] = b"56"
               >>> b.getvalue()
               b'ab56ef'

               Nota: As long as the view exists, the *note BytesIO:
               10a6. object cannot be resized or closed.

          Added in version 3.2.

      -- Metodo: getvalue ()

          Return *note bytes: 192. containing the entire contents of the
          buffer.

      -- Metodo: read1 (size=-1, /)

          In *note BytesIO: 10a6, this is the same as *note read():
          1530.

          Cambiato nella versione 3.7: The 'size' argument is now
          optional.

      -- Metodo: readinto1 (b, /)

          In *note BytesIO: 10a6, this is the same as *note readinto():
          187d.

          Added in version 3.5.

 -- Classe: io.BufferedReader (raw, buffer_size=DEFAULT_BUFFER_SIZE)

     A buffered binary stream providing higher-level access to a
     readable, non seekable *note RawIOBase: 12d8. raw binary stream.
     It inherits from *note BufferedIOBase: 8a4.

     When reading data from this object, a larger amount of data may be
     requested from the underlying raw stream, and kept in an internal
     buffer.  The buffered data can then be returned directly on
     subsequent reads.

     The constructor creates a *note BufferedReader: 1416. for the given
     readable 'raw' stream and 'buffer_size'.  If 'buffer_size' is
     omitted, *note DEFAULT_BUFFER_SIZE: 1a25. is used.

     *note BufferedReader: 1416. provides or overrides these methods in
     addition to those from *note BufferedIOBase: 8a4. and *note IOBase:
     506.:

      -- Metodo: peek (size=0, /)

          Return bytes from the stream without advancing the position.
          The number of bytes returned may be less or more than
          requested.  If the underlying raw stream is non-blocking and
          the operation would block, returns empty bytes.

      -- Metodo: read (size=-1, /)

          In *note BufferedReader: 1416. this is the same as *note
          io.BufferedIOBase.read(): 1530.

      -- Metodo: read1 (size=-1, /)

          In *note BufferedReader: 1416. this is the same as *note
          io.BufferedIOBase.read1(): 2e3c.

          Cambiato nella versione 3.7: The 'size' argument is now
          optional.

 -- Classe: io.BufferedWriter (raw, buffer_size=DEFAULT_BUFFER_SIZE)

     A buffered binary stream providing higher-level access to a
     writeable, non seekable *note RawIOBase: 12d8. raw binary stream.
     It inherits from *note BufferedIOBase: 8a4.

     When writing to this object, data is normally placed into an
     internal buffer.  The buffer will be written out to the underlying
     *note RawIOBase: 12d8. object under various conditions, including:

        * when the buffer gets too small for all pending data;

        * when *note flush(): 3101. is called;

        * when a *note seek(): 1494. is requested (for *note
          BufferedRandom: 15ba. objects);

        * when the *note BufferedWriter: 15b9. object is closed or
          destroyed.

     The constructor creates a *note BufferedWriter: 15b9. for the given
     writeable 'raw' stream.  If the 'buffer_size' is not given, it
     defaults to *note DEFAULT_BUFFER_SIZE: 1a25.

     *note BufferedWriter: 15b9. provides or overrides these methods in
     addition to those from *note BufferedIOBase: 8a4. and *note IOBase:
     506.:

      -- Metodo: flush ()

          Force bytes held in the buffer into the raw stream.  A *note
          BlockingIOError: 235. should be raised if the raw stream
          blocks.

      -- Metodo: write (b, /)

          Write the *note bytes-like object: 193, 'b', and return the
          number of bytes written.  When in non-blocking mode, a *note
          BlockingIOError: 235. with *note
          BlockingIOError.characters_written: 26e4. set is raised if the
          buffer needs to be written out but the raw stream blocks.

 -- Classe: io.BufferedRandom (raw, buffer_size=DEFAULT_BUFFER_SIZE)

     A buffered binary stream providing higher-level access to a
     seekable *note RawIOBase: 12d8. raw binary stream.  It inherits
     from *note BufferedReader: 1416. and *note BufferedWriter: 15b9.

     The constructor creates a reader and writer for a seekable raw
     stream, given in the first argument.  If the 'buffer_size' is
     omitted it defaults to *note DEFAULT_BUFFER_SIZE: 1a25.

     *note BufferedRandom: 15ba. is capable of anything *note
     BufferedReader: 1416. or *note BufferedWriter: 15b9. can do.  In
     addition, *note seek(): 1494. and *note tell(): 15b4. are
     guaranteed to be implemented.

 -- Classe: io.BufferedRWPair (reader, writer,
          buffer_size=DEFAULT_BUFFER_SIZE, /)

     A buffered binary stream providing higher-level access to two non
     seekable *note RawIOBase: 12d8. raw binary streams—one readable,
     the other writeable.  It inherits from *note BufferedIOBase: 8a4.

     'reader' and 'writer' are *note RawIOBase: 12d8. objects that are
     readable and writeable respectively.  If the 'buffer_size' is
     omitted it defaults to *note DEFAULT_BUFFER_SIZE: 1a25.

     *note BufferedRWPair: 15bb. implements all of *note BufferedIOBase:
     8a4.'s methods except for *note detach(): 2dd1, which raises *note
     UnsupportedOperation: 1d67.

          Avvertimento: *note BufferedRWPair: 15bb. does not attempt to
          synchronize accesses to its underlying raw streams.  You
          should not pass it the same object as reader and writer; use
          *note BufferedRandom: 15ba. instead.


File: python.info,  Node: Text I/O<2>,  Prev: Buffered Streams,  Up: Class hierarchy

5.16.2.12 Text I/O
..................

 -- Classe: io.TextIOBase

     Base class for text streams.  This class provides a character and
     line based interface to stream I/O. It inherits from *note IOBase:
     506.

     *note TextIOBase: 8a5. provides or overrides these data attributes
     and methods in addition to those from *note IOBase: 506.:

      -- Attributo: encoding

          The name of the encoding used to decode the stream’s bytes
          into strings, and to encode strings into bytes.

      -- Attributo: errors

          The error setting of the decoder or encoder.

      -- Attributo: newlines

          A string, a tuple of strings, or ‘None’, indicating the
          newlines translated so far.  Depending on the implementation
          and the initial constructor flags, this may not be available.

      -- Attributo: buffer

          The underlying binary buffer (a *note BufferedIOBase: 8a4. or
          *note RawIOBase: 12d8. instance) that *note TextIOBase: 8a5.
          deals with.  This is not part of the *note TextIOBase: 8a5.
          API and may not exist in some implementations.

      -- Metodo: detach ()

          Separate the underlying binary buffer from the *note
          TextIOBase: 8a5. and return it.

          After the underlying buffer has been detached, the *note
          TextIOBase: 8a5. is in an unusable state.

          Some *note TextIOBase: 8a5. implementations, like *note
          StringIO: 112b, may not have the concept of an underlying
          buffer and calling this method will raise *note
          UnsupportedOperation: 1d67.

          Added in version 3.1.

      -- Metodo: read (size=-1, /)

          Read and return at most 'size' characters from the stream as a
          single *note str: 169.  If 'size' is negative or ‘None’, reads
          until EOF.

      -- Metodo: readline (size=-1, /)

          Read until newline or EOF and return a single *note str: 169.
          If the stream is already at EOF, an empty string is returned.

          If 'size' is specified, at most 'size' characters will be
          read.

      -- Metodo: seek (offset, whence=SEEK_SET, /)

          Change the stream position to the given 'offset'.  Behaviour
          depends on the 'whence' parameter.  The default value for
          'whence' is ‘SEEK_SET’.

             * ‘SEEK_SET’ or ‘0’: seek from the start of the stream (the
               default); 'offset' must either be a number returned by
               *note TextIOBase.tell(): 3107, or zero.  Any other
               'offset' value produces undefined behaviour.

             * ‘SEEK_CUR’ or ‘1’: «seek» to the current position;
               'offset' must be zero, which is a no-operation (all other
               values are unsupported).

             * ‘SEEK_END’ or ‘2’: seek to the end of the stream;
               'offset' must be zero (all other values are unsupported).

          Return the new absolute position as an opaque number.

          Added in version 3.1: The ‘SEEK_*’ constants.

      -- Metodo: tell ()

          Return the current stream position as an opaque number.  The
          number does not usually represent a number of bytes in the
          underlying binary storage.

      -- Metodo: write (s, /)

          Write the string 's' to the stream and return the number of
          characters written.

 -- Classe: io.TextIOWrapper (buffer, encoding=None, errors=None,
          newline=None, line_buffering=False, write_through=False)

     A buffered text stream providing higher-level access to a *note
     BufferedIOBase: 8a4. buffered binary stream.  It inherits from
     *note TextIOBase: 8a5.

     'encoding' gives the name of the encoding that the stream will be
     decoded or encoded with.  In *note UTF-8 Mode: 867, this defaults
     to UTF-8.  Otherwise, it defaults to *note locale.getencoding():
     329.  ‘encoding="locale"’ can be used to specify the current
     locale’s encoding explicitly.  See *note Text Encoding: 9c2. for
     more information.

     'errors' is an optional string that specifies how encoding and
     decoding errors are to be handled.  Pass ‘'strict'’ to raise a
     *note ValueError: 2ec. exception if there is an encoding error (the
     default of ‘None’ has the same effect), or pass ‘'ignore'’ to
     ignore errors.  (Note that ignoring encoding errors can lead to
     data loss.)  ‘'replace'’ causes a replacement marker (such as
     ‘'?'’) to be inserted where there is malformed data.
     ‘'backslashreplace'’ causes malformed data to be replaced by a
     backslashed escape sequence.  When writing, ‘'xmlcharrefreplace'’
     (replace with the appropriate XML character reference) or
     ‘'namereplace'’ (replace with ‘\N{...}’ escape sequences) can be
     used.  Any other error handling name that has been registered with
     *note codecs.register_error(): 16a2. is also valid.

     'newline' controls how line endings are handled.  It can be ‘None’,
     ‘''’, ‘'\n'’, ‘'\r'’, and ‘'\r\n'’.  It works as follows:

        * When reading input from the stream, if 'newline' is ‘None’,
          *note universal newlines: f37. mode is enabled.  Lines in the
          input can end in ‘'\n'’, ‘'\r'’, or ‘'\r\n'’, and these are
          translated into ‘'\n'’ before being returned to the caller.
          If 'newline' is ‘''’, universal newlines mode is enabled, but
          line endings are returned to the caller untranslated.  If
          'newline' has any of the other legal values, input lines are
          only terminated by the given string, and the line ending is
          returned to the caller untranslated.

        * When writing output to the stream, if 'newline' is ‘None’, any
          ‘'\n'’ characters written are translated to the system default
          line separator, *note os.linesep: 25b8.  If 'newline' is ‘''’
          or ‘'\n'’, no translation takes place.  If 'newline' is any of
          the other legal values, any ‘'\n'’ characters written are
          translated to the given string.

     If 'line_buffering' is ‘True’, *note flush(): 2ccc. is implied when
     a call to write contains a newline character or a carriage return.

     If 'write_through' is ‘True’, calls to *note write(): ed9. are
     guaranteed not to be buffered: any data written on the *note
     TextIOWrapper: 9c0. object is immediately handled to its underlying
     binary 'buffer'.

     Cambiato nella versione 3.3: The 'write_through' argument has been
     added.

     Cambiato nella versione 3.3: The default 'encoding' is now
     ‘locale.getpreferredencoding(False)’ instead of
     ‘locale.getpreferredencoding()’.  Don’t change temporary the locale
     encoding using *note locale.setlocale(): 328, use the current
     locale encoding instead of the user preferred encoding.

     Cambiato nella versione 3.10: The 'encoding' argument now supports
     the ‘"locale"’ dummy encoding name.

          Nota: When the underlying raw stream is non-blocking, a *note
          BlockingIOError: 235. may be raised if a read operation cannot
          be completed immediately.

     *note TextIOWrapper: 9c0. provides these data attributes and
     methods in addition to those from *note TextIOBase: 8a5. and *note
     IOBase: 506.:

      -- Attributo: line_buffering

          Whether line buffering is enabled.

      -- Attributo: write_through

          Whether writes are passed immediately to the underlying binary
          buffer.

          Added in version 3.7.

      -- Metodo: reconfigure (*, encoding=None, errors=None,
               newline=None, line_buffering=None, write_through=None)

          Reconfigure this text stream using new settings for
          'encoding', 'errors', 'newline', 'line_buffering' and
          'write_through'.

          Parameters not specified keep current settings, except
          ‘errors='strict'’ is used when 'encoding' is specified but
          'errors' is not specified.

          It is not possible to change the encoding or newline if some
          data has already been read from the stream.  On the other
          hand, changing encoding after write is possible.

          This method does an implicit stream flush before setting the
          new parameters.

          Added in version 3.7.

          Cambiato nella versione 3.11: The method supports
          ‘encoding="locale"’ option.

      -- Metodo: seek (cookie, whence=os.SEEK_SET, /)

          Set the stream position.  Return the new stream position as an
          *note int: 19b.

          Four operations are supported, given by the following argument
          combinations:

             * ‘seek(0, SEEK_SET)’: Rewind to the start of the stream.

             * ‘seek(cookie, SEEK_SET)’: Restore a previous position;
               'cookie' 'must be' a number returned by *note tell():
               1799.

             * ‘seek(0, SEEK_END)’: Fast-forward to the end of the
               stream.

             * ‘seek(0, SEEK_CUR)’: Leave the current stream position
               unchanged.

          Any other argument combinations are invalid, and may raise
          exceptions.

          Vedi anche
          ..........

          *note os.SEEK_SET: 1495, *note os.SEEK_CUR: 1496, and *note
          os.SEEK_END: 1497.

      -- Metodo: tell ()

          Return the stream position as an opaque number.  The return
          value of ‘tell()’ can be given as input to *note seek(): 310a,
          to restore a previous stream position.

 -- Classe: io.StringIO (initial_value='', newline='\n')

     A text stream using an in-memory text buffer.  It inherits from
     *note TextIOBase: 8a5.

     The text buffer is discarded when the *note close(): 507. method is
     called.

     The initial value of the buffer can be set by providing
     'initial_value'.  If newline translation is enabled, newlines will
     be encoded as if by *note write(): 2045.  The stream is positioned
     at the start of the buffer which emulates opening an existing file
     in a ‘w+’ mode, making it ready for an immediate write from the
     beginning or for a write that would overwrite the initial value.
     To emulate opening a file in an ‘a+’ mode ready for appending, use
     ‘f.seek(0, io.SEEK_END)’ to reposition the stream at the end of the
     buffer.

     The 'newline' argument works like that of *note TextIOWrapper: 9c0,
     except that when writing output to the stream, if 'newline' is
     ‘None’, newlines are written as ‘\n’ on all platforms.

     *note StringIO: 112b. provides this method in addition to those
     from *note TextIOBase: 8a5. and *note IOBase: 506.:

      -- Metodo: getvalue ()

          Return a *note str: 169. containing the entire contents of the
          buffer.  Newlines are decoded as if by *note read(): 2056,
          although the stream position is not changed.

     Example usage:

          import io

          output = io.StringIO()
          output.write('First line.\n')
          print('Second line.', file=output)

          # Retrieve file contents -- this will be
          # 'First line.\nSecond line.\n'
          contents = output.getvalue()

          # Close object and discard memory buffer --
          # .getvalue() will now raise an exception.
          output.close()

 -- Classe: io.IncrementalNewlineDecoder

     A helper codec that decodes newlines for *note universal newlines:
     f37. mode.  It inherits from *note codecs.IncrementalDecoder: 281b.


File: python.info,  Node: Static Typing,  Next: Performance<3>,  Prev: Class hierarchy,  Up: io — Core tools for working with streams

5.16.2.13 Static Typing
.......................

The following protocols can be used for annotating function and method
arguments for simple stream reading or writing operations.  They are
decorated with *note @typing.runtime_checkable: 675.

 -- Classe: io.Reader [T]

     Generic protocol for reading from a file or other input stream.
     ‘T’ will usually be *note str: 169. or *note bytes: 192, but can be
     any type that is read from the stream.

     Added in version 3.14.

      -- Metodo: read ()

      -- Metodo: read (size, /)

          Read data from the input stream and return it.  If 'size' is
          specified, it should be an integer, and at most 'size' items
          (bytes/characters) will be read.

     For example:

          def read_it(reader: Reader[str]):
              data = reader.read(11)
              assert isinstance(data, str)

 -- Classe: io.Writer [T]

     Generic protocol for writing to a file or other output stream.  ‘T’
     will usually be *note str: 169. or *note bytes: 192, but can be any
     type that can be written to the stream.

     Added in version 3.14.

      -- Metodo: write (data, /)

          Write 'data' to the output stream and return the number of
          items (bytes/characters) written.

     For example:

          def write_binary(writer: Writer[bytes]):
              writer.write(b"Hello world!\n")

See *note ABCs and Protocols for working with I/O: 310f. for other I/O
related protocols and classes that can be used for static type checking.


File: python.info,  Node: Performance<3>,  Prev: Static Typing,  Up: io — Core tools for working with streams

5.16.2.14 Performance
.....................

This section discusses the performance of the provided concrete I/O
implementations.

* Menu:

* Binary I/O: Binary I/O<2>.
* Text I/O: Text I/O<3>.
* Multi-threading: Multi-threading<3>.
* Reentrancy::


File: python.info,  Node: Binary I/O<2>,  Next: Text I/O<3>,  Up: Performance<3>

5.16.2.15 Binary I/O
....................

By reading and writing only large chunks of data even when the user asks
for a single byte, buffered I/O hides any inefficiency in calling and
executing the operating system’s unbuffered I/O routines.  The gain
depends on the OS and the kind of I/O which is performed.  For example,
on some modern OSes such as Linux, unbuffered disk I/O can be as fast as
buffered I/O. The bottom line, however, is that buffered I/O offers
predictable performance regardless of the platform and the backing
device.  Therefore, it is almost always preferable to use buffered I/O
rather than unbuffered I/O for binary data.


File: python.info,  Node: Text I/O<3>,  Next: Multi-threading<3>,  Prev: Binary I/O<2>,  Up: Performance<3>

5.16.2.16 Text I/O
..................

Text I/O over a binary storage (such as a file) is significantly slower
than binary I/O over the same storage, because it requires conversions
between unicode and binary data using a character codec.  This can
become noticeable handling huge amounts of text data like large log
files.  Also, *note tell(): 3107. and *note seek(): 3106. are both quite
slow due to the reconstruction algorithm used.

*note StringIO: 112b, however, is a native in-memory unicode container
and will exhibit similar speed to *note BytesIO: 10a6.


File: python.info,  Node: Multi-threading<3>,  Next: Reentrancy,  Prev: Text I/O<3>,  Up: Performance<3>

5.16.2.17 Multi-threading
.........................

*note FileIO: 1517. objects are thread-safe to the extent that the
operating system calls (such as ‘read(2)(1)’ under Unix) they wrap are
thread-safe too.

Binary buffered objects (instances of *note BufferedReader: 1416, *note
BufferedWriter: 15b9, *note BufferedRandom: 15ba. and *note
BufferedRWPair: 15bb.) protect their internal structures using a lock;
it is therefore safe to call them from multiple threads at once.

*note TextIOWrapper: 9c0. objects are not thread-safe.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/read(2)


File: python.info,  Node: Reentrancy,  Prev: Multi-threading<3>,  Up: Performance<3>

5.16.2.18 Reentrancy
....................

Binary buffered objects (instances of *note BufferedReader: 1416, *note
BufferedWriter: 15b9, *note BufferedRandom: 15ba. and *note
BufferedRWPair: 15bb.) are not reentrant.  While reentrant calls will
not happen in normal situations, they can arise from doing I/O in a
*note signal: cb. handler.  If a thread tries to re-enter a buffered
object which it is already accessing, a *note RuntimeError: 244. is
raised.  Note this doesn’t prohibit a different thread from entering the
buffered object.

The above implicitly extends to text files, since the *note open(): 316.
function will wrap a buffered object inside a *note TextIOWrapper: 9c0.
This includes standard streams and therefore affects the built-in *note
print(): 1177. function as well.


File: python.info,  Node: time — Time access and conversions,  Next: logging — Logging facility for Python,  Prev: io — Core tools for working with streams,  Up: Generic Operating System Services

5.16.3 ‘time’ — Time access and conversions
-------------------------------------------

__________________________________________________________________

This module provides various time-related functions.  For related
functionality, see also the *note datetime: 34. and *note calendar: 15.
modules.

Although this module is always available, not all functions are
available on all platforms.  Most of the functions defined in this
module call platform C library functions with the same name.  It may
sometimes be helpful to consult the platform documentation, because the
semantics of these functions varies among platforms.

An explanation of some terminology and conventions is in order.

   * The 'epoch' is the point where the time starts, the return value of
     ‘time.gmtime(0)’.  It is January 1, 1970, 00:00:00 (UTC) on all
     platforms.

   * The term 'seconds since the epoch' refers to the total number of
     elapsed seconds since the epoch, typically excluding leap
     seconds(1).  Leap seconds are excluded from this total on all
     POSIX-compliant platforms.

   * The functions in this module may not handle dates and times before
     the *note epoch: 2ef9. or far in the future.  The cut-off point in
     the future is determined by the C library; for 32-bit systems, it
     is typically in 2038.

   * Function *note strptime(): 1634. can parse 2-digit years when given
     ‘%y’ format code.  When 2-digit years are parsed, they are
     converted according to the POSIX and ISO C standards: values 69–99
     are mapped to 1969–1999, and values 0–68 are mapped to 2000–2068.

   * UTC is Coordinated Universal Time(2) and superseded Greenwich Mean
     Time(3) or GMT as the basis of international timekeeping.  The
     acronym UTC is not a mistake but conforms to an earlier,
     language-agnostic naming scheme for time standards such as UT0,
     UT1, and UT2.

   * DST is Daylight Saving Time, an adjustment of the timezone by
     (usually) one hour during part of the year.  DST rules are magic
     (determined by local law) and can change from year to year.  The C
     library has a table containing the local rules (often it is read
     from a system file for flexibility) and is the only source of True
     Wisdom in this respect.

   * The precision of the various real-time functions may be less than
     suggested by the units in which their value or argument is
     expressed.  E.g.  on most Unix systems, the clock «ticks» only 50
     or 100 times a second.

   * On the other hand, the precision of *note time(): 55d. and *note
     sleep(): 8ad. is better than their Unix equivalents: times are
     expressed as floating-point numbers, *note time(): 55d. returns the
     most accurate time available (using Unix ‘gettimeofday()’ where
     available), and *note sleep(): 8ad. will accept a time with a
     nonzero fraction (Unix ‘select()’ is used to implement this, where
     available).

   * The time value as returned by *note gmtime(): 13c8, *note
     localtime(): 1700, and *note strptime(): 1634, and accepted by
     *note asctime(): 13ef, *note mktime(): 13f0. and *note strftime():
     13f1, is a sequence of 9 integers.  The return values of *note
     gmtime(): 13c8, *note localtime(): 1700, and *note strptime():
     1634. also offer attribute names for individual fields.

     See *note struct_time: ee8. for a description of these objects.

     Cambiato nella versione 3.3: The *note struct_time: ee8. type was
     extended to provide the *note tm_gmtoff: 3118. and *note tm_zone:
     3119. attributes when platform supports corresponding ‘struct tm’
     members.

     Cambiato nella versione 3.6: The *note struct_time: ee8. attributes
     *note tm_gmtoff: 3118. and *note tm_zone: 3119. are now available
     on all platforms.

   * Use the following functions to convert between time
     representations:

     From                          To                            Use
                                                                 
     ------------------------------------------------------------------------------------------
                                                                 
     seconds since the epoch       *note struct_time: ee8. in    *note gmtime(): 13c8.
                                   UTC                           
                                   
                                                                 
     seconds since the epoch       *note struct_time: ee8. in    *note localtime(): 1700.
                                   local time                    
                                   
                                                                 
     *note struct_time: ee8. in    seconds since the epoch       *note calendar.timegm(): 292c.
     UTC                                                         

     *note struct_time: ee8. in    seconds since the epoch       *note mktime(): 13f0.
     local time                                                  

* Menu:

* Functions: Functions<4>.
* Clock ID Constants::
* Timezone Constants::

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Leap_second

   (2) https://en.wikipedia.org/wiki/Coordinated_Universal_Time

   (3) https://en.wikipedia.org/wiki/Greenwich_Mean_Time


File: python.info,  Node: Functions<4>,  Next: Clock ID Constants,  Up: time — Time access and conversions

5.16.3.1 Functions
..................

 -- Funzione: time.asctime ([t])

     Convert a tuple or *note struct_time: ee8. representing a time as
     returned by *note gmtime(): 13c8. or *note localtime(): 1700. to a
     string of the following form: ‘'Sun Jun 20 23:21:05 1993'’.  The
     day field is two characters long and is space padded if the day is
     a single digit, e.g.: ‘'Wed Jun 9 04:26:40 1993'’.

     If 't' is not provided, the current time as returned by *note
     localtime(): 1700. is used.  Locale information is not used by
     *note asctime(): 13ef.

          Nota: Unlike the C function of the same name, *note asctime():
          13ef. does not add a trailing newline.

 -- Funzione: time.pthread_getcpuclockid (thread_id)

     Return the 'clk_id' of the thread-specific CPU-time clock for the
     specified 'thread_id'.

     Use *note threading.get_ident(): 1362. or the *note ident: 311c.
     attribute of *note threading.Thread: 176. objects to get a suitable
     value for 'thread_id'.

          Avvertimento: Passing an invalid or expired 'thread_id' may
          result in undefined behavior, such as segmentation fault.

     *note Availability: 2128.: Unix

     See the man page for ‘pthread_getcpuclockid(3)(1)’ for further
     information.

     Added in version 3.7.

 -- Funzione: time.clock_getres (clk_id)

     Return the resolution (precision) of the specified clock 'clk_id'.
     Refer to *note Clock ID Constants: 3092. for a list of accepted
     values for 'clk_id'.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Funzione: time.clock_gettime (clk_id) -> float

     Return the time of the specified clock 'clk_id'.  Refer to *note
     Clock ID Constants: 3092. for a list of accepted values for
     'clk_id'.

     Use *note clock_gettime_ns(): cdd. to avoid the precision loss
     caused by the *note float: 196. type.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Funzione: time.clock_gettime_ns (clk_id) -> int

     Similar to *note clock_gettime(): 1366. but return time as
     nanoseconds.

     *note Availability: 2128.: Unix.

     Added in version 3.7.

 -- Funzione: time.clock_settime (clk_id, time: float)

     Set the time of the specified clock 'clk_id'.  Currently, *note
     CLOCK_REALTIME: 8aa. is the only accepted value for 'clk_id'.

     Use *note clock_settime_ns(): cde. to avoid the precision loss
     caused by the *note float: 196. type.

     *note Availability: 2128.: Unix, not Android, not iOS.

     Added in version 3.3.

 -- Funzione: time.clock_settime_ns (clk_id, time: int)

     Similar to *note clock_settime(): 1367. but set time with
     nanoseconds.

     *note Availability: 2128.: Unix, not Android, not iOS.

     Added in version 3.7.

 -- Funzione: time.ctime ([secs])

     Convert a time expressed in seconds since the *note epoch: 2ef9. to
     a string of a form: ‘'Sun Jun 20 23:21:05 1993'’ representing local
     time.  The day field is two characters long and is space padded if
     the day is a single digit, e.g.: ‘'Wed Jun 9 04:26:40 1993'’.

     If 'secs' is not provided or *note None: 886, the current time as
     returned by *note time(): 55d. is used.  ‘ctime(secs)’ is
     equivalent to ‘asctime(localtime(secs))’.  Locale information is
     not used by *note ctime(): 28a9.

 -- Funzione: time.get_clock_info (name)

     Get information on the specified clock as a namespace object.
     Supported clock names and the corresponding functions to read their
     value are:

        * ‘'monotonic'’: *note time.monotonic(): 55c.

        * ‘'perf_counter'’: *note time.perf_counter(): c7c.

        * ‘'process_time'’: *note time.process_time(): c7d.

        * ‘'thread_time'’: *note time.thread_time(): b32.

        * ‘'time'’: *note time.time(): 55d.

     The result has the following attributes:

        - 'adjustable': ‘True’ if the clock can be set to jump forward
          or backward in time, ‘False’ otherwise.  Does not refer to
          gradual NTP rate adjustments.

        - 'implementation': The name of the underlying C function used
          to get the clock value.  Refer to *note Clock ID Constants:
          3092. for possible values.

        - 'monotonic': ‘True’ if the clock cannot go backward, ‘False’
          otherwise

        - 'resolution': The resolution of the clock in seconds (*note
          float: 196.)

     Added in version 3.3.

 -- Funzione: time.gmtime ([secs])

     Convert a time expressed in seconds since the *note epoch: 2ef9. to
     a *note struct_time: ee8. in UTC in which the dst flag is always
     zero.  If 'secs' is not provided or *note None: 886, the current
     time as returned by *note time(): 55d. is used.  Fractions of a
     second are ignored.  See above for a description of the *note
     struct_time: ee8. object.  See *note calendar.timegm(): 292c. for
     the inverse of this function.

 -- Funzione: time.localtime ([secs])

     Like *note gmtime(): 13c8. but converts to local time.  If 'secs'
     is not provided or *note None: 886, the current time as returned by
     *note time(): 55d. is used.  The dst flag is set to ‘1’ when DST
     applies to the given time.

     *note localtime(): 1700. may raise *note OverflowError: a83, if the
     timestamp is outside the range of values supported by the platform
     C ‘localtime()’ or ‘gmtime()’ functions, and *note OSError: 2c0. on
     ‘localtime()’ or ‘gmtime()’ failure.  It’s common for this to be
     restricted to years between 1970 and 2038.

 -- Funzione: time.mktime (t)

     This is the inverse function of *note localtime(): 1700.  Its
     argument is the *note struct_time: ee8. or full 9-tuple (since the
     dst flag is needed; use ‘-1’ as the dst flag if it is unknown)
     which expresses the time in 'local' time, not UTC. It returns a
     floating-point number, for compatibility with *note time(): 55d.
     If the input value cannot be represented as a valid time, either
     *note OverflowError: a83. or *note ValueError: 2ec. will be raised
     (which depends on whether the invalid value is caught by Python or
     the underlying C libraries).  The earliest date for which it can
     generate a time is platform-dependent.

 -- Funzione: time.monotonic () -> float

     Return the value (in fractional seconds) of a monotonic clock, i.e.
     a clock that cannot go backwards.  The clock is not affected by
     system clock updates.  The reference point of the returned value is
     undefined, so that only the difference between the results of two
     calls is valid.

     Clock:

        * On Windows, call ‘QueryPerformanceCounter()’ and
          ‘QueryPerformanceFrequency()’.

        * On macOS, call ‘mach_absolute_time()’ and
          ‘mach_timebase_info()’.

        * On HP-UX, call ‘gethrtime()’.

        * Call ‘clock_gettime(CLOCK_HIGHRES)’ if available.

        * Otherwise, call ‘clock_gettime(CLOCK_MONOTONIC)’.

     Use *note monotonic_ns(): cdf. to avoid the precision loss caused
     by the *note float: 196. type.

     Added in version 3.3.

     Cambiato nella versione 3.5: The function is now always available
     and the clock is now the same for all processes.

     Cambiato nella versione 3.10: On macOS, the clock is now the same
     for all processes.

 -- Funzione: time.monotonic_ns () -> int

     Similar to *note monotonic(): 55c, but return time as nanoseconds.

     Added in version 3.7.

 -- Funzione: time.perf_counter () -> float

     Return the value (in fractional seconds) of a performance counter,
     i.e.  a clock with the highest available resolution to measure a
     short duration.  It does include time elapsed during sleep.  The
     clock is the same for all processes.  The reference point of the
     returned value is undefined, so that only the difference between
     the results of two calls is valid.

     'Dettaglio dell’implementazione di CPython:' On CPython, use the
     same clock as *note time.monotonic(): 55c. and is a monotonic
     clock, i.e.  a clock that cannot go backwards.

     Use *note perf_counter_ns(): ce0. to avoid the precision loss
     caused by the *note float: 196. type.

     Added in version 3.3.

     Cambiato nella versione 3.10: On Windows, the clock is now the same
     for all processes.

     Cambiato nella versione 3.13: Use the same clock as *note
     time.monotonic(): 55c.

 -- Funzione: time.perf_counter_ns () -> int

     Similar to *note perf_counter(): c7c, but return time as
     nanoseconds.

     Added in version 3.7.

 -- Funzione: time.process_time () -> float

     Return the value (in fractional seconds) of the sum of the system
     and user CPU time of the current process.  It does not include time
     elapsed during sleep.  It is process-wide by definition.  The
     reference point of the returned value is undefined, so that only
     the difference between the results of two calls is valid.

     Use *note process_time_ns(): ce1. to avoid the precision loss
     caused by the *note float: 196. type.

     Added in version 3.3.

 -- Funzione: time.process_time_ns () -> int

     Similar to *note process_time(): c7d. but return time as
     nanoseconds.

     Added in version 3.7.

 -- Funzione: time.sleep (secs)

     Suspend execution of the calling thread for the given number of
     seconds.  The argument may be a floating-point number to indicate a
     more precise sleep time.

     If the sleep is interrupted by a signal and no exception is raised
     by the signal handler, the sleep is restarted with a recomputed
     timeout.

     The suspension time may be longer than requested by an arbitrary
     amount, because of the scheduling of other activity in the system.

     Windows implementation
     ......................

     On Windows, if 'secs' is zero, the thread relinquishes the
     remainder of its time slice to any other thread that is ready to
     run.  If there are no other threads ready to run, the function
     returns immediately, and the thread continues execution.  On
     Windows 10 and newer the implementation uses a high-resolution
     timer(2) which provides resolution of 100 nanoseconds.  If 'secs'
     is zero, ‘Sleep(0)’ is used.

     Unix implementation
     ...................

        * Use ‘clock_nanosleep()’ if available (resolution: 1
          nanosecond);

        * Or use ‘nanosleep()’ if available (resolution: 1 nanosecond);

        * Or use ‘select()’ (resolution: 1 microsecond).

          Nota: To emulate a «no-op», use *note pass: 17e. instead of
          ‘time.sleep(0)’.

          To voluntarily relinquish the CPU, specify a real-time *note
          scheduling policy: 30d9. and use *note os.sched_yield(): 1319.
          instead.

     Raises an *note auditing event: 1c56. ‘time.sleep’ with argument
     ‘secs’.

     Cambiato nella versione 3.5: The function now sleeps at least
     'secs' even if the sleep is interrupted by a signal, except if the
     signal handler raises an exception (see PEP 475(3) for the
     rationale).

     Cambiato nella versione 3.11: On Unix, the ‘clock_nanosleep()’ and
     ‘nanosleep()’ functions are now used if available.  On Windows, a
     waitable timer is now used.

     Cambiato nella versione 3.13: Raises an auditing event.

 -- Funzione: time.strftime (format[, t])

     Convert a tuple or *note struct_time: ee8. representing a time as
     returned by *note gmtime(): 13c8. or *note localtime(): 1700. to a
     string as specified by the 'format' argument.  If 't' is not
     provided, the current time as returned by *note localtime(): 1700.
     is used.  'format' must be a string.  *note ValueError: 2ec. is
     raised if any field in 't' is outside of the allowed range.

     0 is a legal argument for any position in the time tuple; if it is
     normally illegal the value is forced to a correct one.

     The following directives can be embedded in the 'format' string.
     They are shown without the optional field width and precision
     specification, and are replaced by the indicated characters in the
     *note strftime(): 13f1. result:

     Directive       Meaning                                              Notes
                                                                          
     ---------------------------------------------------------------------------------
                                                                          
     ‘%a’            Locale’s abbreviated weekday name.
                     
                                                                          
     ‘%A’            Locale’s full weekday name.
                     
                                                                          
     ‘%b’            Locale’s abbreviated month name.
                     
                                                                          
     ‘%B’            Locale’s full month name.
                     
                                                                          
     ‘%c’            Locale’s appropriate date and time representation.
                     
                                                                          
     ‘%d’            Day of the month as a decimal number [01,31].
                     
                                                                          
     ‘%f’            Microseconds as a decimal number                     (1)
                                                                          
                          [000000,999999].
                     
                                                                          
     ‘%H’            Hour (24-hour clock) as a decimal number [00,23].
                     
                                                                          
     ‘%I’            Hour (12-hour clock) as a decimal number [01,12].
                     
                                                                          
     ‘%j’            Day of the year as a decimal number [001,366].
                     
                                                                          
     ‘%m’            Month as a decimal number [01,12].
                     
                                                                          
     ‘%M’            Minute as a decimal number [00,59].
                     
                                                                          
     ‘%p’            Locale’s equivalent of either AM or PM.              (2)
                                                                          
                                                                          
     ‘%S’            Second as a decimal number [00,61].                  (3)
                                                                          
                                                                          
     ‘%U’            Week number of the year (Sunday as the first day     (4)
                     of the week) as a decimal number [00,53].  All       
                     days in a new year preceding the first Sunday are
                     considered to be in week 0.
                     
                                                                          
     ‘%u’            Day of the week (Monday is 1; Sunday is 7) as a
                     decimal number [1, 7].
                     
                                                                          
     ‘%w’            Weekday as a decimal number [0(Sunday),6].
                     
                                                                          
     ‘%W’            Week number of the year (Monday as the first day     (4)
                     of the week) as a decimal number [00,53].  All       
                     days in a new year preceding the first Monday are
                     considered to be in week 0.
                     
                                                                          
     ‘%x’            Locale’s appropriate date representation.
                     
                                                                          
     ‘%X’            Locale’s appropriate time representation.
                     
                                                                          
     ‘%y’            Year without century as a decimal number [00,99].
                     
                                                                          
     ‘%Y’            Year with century as a decimal number.
                     
                                                                          
     ‘%z’            Time zone offset indicating a positive or negative
                     time difference from UTC/GMT of the form +HHMM or
                     -HHMM, where H represents decimal hour digits and
                     M represents decimal minute digits [-23:59,
                     +23:59].  (4)
                     
                                                                          
     ‘%Z’            Time zone name (no characters if no time zone
                     exists).  Deprecated.  (5)
                     
                                                                          
     ‘%G’            ISO 8601 year (similar to ‘%Y’ but follows the
                     rules for the ISO 8601 calendar year).  The year
                     starts with the week that contains the first
                     Thursday of the calendar year.
                     
                                                                          
     ‘%V’            ISO 8601 week number (as a decimal number
                     [01,53]).  The first week of the year is the one
                     that contains the first Thursday of the year.
                     Weeks start on Monday.
                     
                                                                          
     ‘%%’            A literal ‘'%'’ character.
                     

     Notes:

       1. The ‘%f’ format directive only applies to *note strptime():
          1634, not to *note strftime(): 13f1.  However, see also *note
          datetime.datetime.strptime(): 1938. and *note
          datetime.datetime.strftime(): e90. where the ‘%f’ format
          directive *note applies to microseconds: 287b.

       2. When used with the *note strptime(): 1634. function, the ‘%p’
          directive only affects the output hour field if the ‘%I’
          directive is used to parse the hour.

       3. The range really is ‘0’ to ‘61’; value ‘60’ is valid in
          timestamps representing leap seconds(6) and value ‘61’ is
          supported for historical reasons.

       4. When used with the *note strptime(): 1634. function, ‘%U’ and
          ‘%W’ are only used in calculations when the day of the week
          and the year are specified.

     Here is an example, a format for dates compatible with that
     specified in the RFC 5322(7) Internet email standard.  (8)

          >>> from time import gmtime, strftime
          >>> strftime("%a, %d %b %Y %H:%M:%S +0000", gmtime())
          'Thu, 28 Jun 2001 14:17:15 +0000'

     Additional directives may be supported on certain platforms, but
     only the ones listed here have a meaning standardized by ANSI C. To
     see the full set of format codes supported on your platform,
     consult the ‘strftime(3)(9)’ documentation.

     On some platforms, an optional field width and precision
     specification can immediately follow the initial ‘'%'’ of a
     directive in the following order; this is also not portable.  The
     field width is normally 2 except for ‘%j’ where it is 3.

 -- Funzione: time.strptime (string[, format])

     Parse a string representing a time according to a format.  The
     return value is a *note struct_time: ee8. as returned by *note
     gmtime(): 13c8. or *note localtime(): 1700.

     The 'format' parameter uses the same directives as those used by
     *note strftime(): 13f1.; it defaults to ‘"%a %b %d %H:%M:%S %Y"’
     which matches the formatting returned by *note ctime(): 28a9.  If
     'string' cannot be parsed according to 'format', or if it has
     excess data after parsing, *note ValueError: 2ec. is raised.  The
     default values used to fill in any missing data when more accurate
     values cannot be inferred are ‘(1900, 1, 1, 0, 0, 0, 0, 1, -1)’.
     Both 'string' and 'format' must be strings.

     For example:

          >>> import time
          >>> time.strptime("30 Nov 00", "%d %b %y")
          time.struct_time(tm_year=2000, tm_mon=11, tm_mday=30, tm_hour=0, tm_min=0,
                           tm_sec=0, tm_wday=3, tm_yday=335, tm_isdst=-1)

     Support for the ‘%Z’ directive is based on the values contained in
     ‘tzname’ and whether ‘daylight’ is true.  Because of this, it is
     platform-specific except for recognizing UTC and GMT which are
     always known (and are considered to be non-daylight savings
     timezones).

     Only the directives specified in the documentation are supported.
     Because ‘strftime()’ is implemented per platform it can sometimes
     offer more directives than those listed.  But ‘strptime()’ is
     independent of any platform and thus does not necessarily support
     all directives available that are not documented as supported.

 -- Classe: time.struct_time

     The type of the time value sequence returned by *note gmtime():
     13c8, *note localtime(): 1700, and *note strptime(): 1634.  It is
     an object with a *note named tuple: 85f. interface: values can be
     accessed by index and by attribute name.  The following values are
     present:

     Index                                 Attribute                             Values
                                                                                 
                                                                                 
     0                                      -- Attributo: tm_year                (for example, 1993)
                                                                                 
                                                                                 
     1                                      -- Attributo: tm_mon                 range [1, 12]
                                                                                 
                                                                                 
     2                                      -- Attributo: tm_mday                range [1, 31]
                                                                                 
                                                                                 
     3                                      -- Attributo: tm_hour                range [0, 23]
                                                                                 
                                                                                 
     4                                      -- Attributo: tm_min                 range [0, 59]
                                                                                 
                                                                                 
     5                                      -- Attributo: tm_sec                 range [0, 61]; see
                                                                                 *note Note (2): 311d. in
                                                                                 *note strftime(): 13f1.
                                                                                 
                                                                                 
     6                                      -- Attributo: tm_wday                range [0, 6]; Monday is 0
                                                                                 
                                                                                 
     7                                      -- Attributo: tm_yday                range [1, 366]
                                                                                 
                                                                                 
     8                                      -- Attributo: tm_isdst               0, 1 or -1; see below
                                                                                 
                                                                                 
     N/A                                    -- Attributo: tm_zone                abbreviation of timezone name
                                                                                 
                                                                                 
     N/A                                    -- Attributo: tm_gmtoff              offset east of UTC in seconds
                                                                                 

     Note that unlike the C structure, the month value is a range of [1,
     12], not [0, 11].

     In calls to *note mktime(): 13f0, *note tm_isdst: 28ba. may be set
     to 1 when daylight savings time is in effect, and 0 when it is not.
     A value of -1 indicates that this is not known, and will usually
     result in the correct state being filled in.

     When a tuple with an incorrect length is passed to a function
     expecting a *note struct_time: ee8, or having elements of the wrong
     type, a *note TypeError: 198. is raised.

 -- Funzione: time.time () -> float

     Return the time in seconds since the *note epoch: 2ef9. as a
     floating-point number.  The handling of leap seconds(10) is
     platform dependent.  On Windows and most Unix systems, the leap
     seconds are not counted towards the time in seconds since the *note
     epoch: 2ef9.  This is commonly referred to as Unix time(11).

     Note that even though the time is always returned as a
     floating-point number, not all systems provide time with a better
     precision than 1 second.  While this function normally returns
     non-decreasing values, it can return a lower value than a previous
     call if the system clock has been set back between the two calls.

     The number returned by *note time(): 55d. may be converted into a
     more common time format (i.e.  year, month, day, hour, etc…) in UTC
     by passing it to *note gmtime(): 13c8. function or in local time by
     passing it to the *note localtime(): 1700. function.  In both cases
     a *note struct_time: ee8. object is returned, from which the
     components of the calendar date may be accessed as attributes.

     Clock:

        * On Windows, call ‘GetSystemTimePreciseAsFileTime()’.

        * Call ‘clock_gettime(CLOCK_REALTIME)’ if available.

        * Otherwise, call ‘gettimeofday()’.

     Use *note time_ns(): ce2. to avoid the precision loss caused by the
     *note float: 196. type.

Cambiato nella versione 3.13: On Windows, calls
‘GetSystemTimePreciseAsFileTime()’ instead of
‘GetSystemTimeAsFileTime()’.

 -- Funzione: time.time_ns () -> int

     Similar to *note time(): 55d. but returns time as an integer number
     of nanoseconds since the *note epoch: 2ef9.

     Added in version 3.7.

 -- Funzione: time.thread_time () -> float

     Return the value (in fractional seconds) of the sum of the system
     and user CPU time of the current thread.  It does not include time
     elapsed during sleep.  It is thread-specific by definition.  The
     reference point of the returned value is undefined, so that only
     the difference between the results of two calls in the same thread
     is valid.

     Use *note thread_time_ns(): d8c. to avoid the precision loss caused
     by the *note float: 196. type.

     *note Availability: 2128.: Linux, Unix, Windows.

     Unix systems supporting ‘CLOCK_THREAD_CPUTIME_ID’.

     Added in version 3.7.

 -- Funzione: time.thread_time_ns () -> int

     Similar to *note thread_time(): b32. but return time as
     nanoseconds.

     Added in version 3.7.

 -- Funzione: time.tzset ()

     Reset the time conversion rules used by the library routines.  The
     environment variable ‘TZ’ specifies how this is done.  It will also
     set the variables ‘tzname’ (from the ‘TZ’ environment variable),
     ‘timezone’ (non-DST seconds West of UTC), ‘altzone’ (DST seconds
     west of UTC) and ‘daylight’ (to 0 if this timezone does not have
     any daylight saving time rules, or to nonzero if there is a time,
     past, present or future when daylight saving time applies).

     *note Availability: 2128.: Unix.

          Nota: Although in many cases, changing the ‘TZ’ environment
          variable may affect the output of functions like *note
          localtime(): 1700. without calling *note tzset(): 3125, this
          behavior should not be relied on.

          The ‘TZ’ environment variable should contain no whitespace.

     The standard format of the ‘TZ’ environment variable is (whitespace
     added for clarity):

          std offset [dst [offset [,start[/time], end[/time]]]]

     Where the components are:

     ‘std’ and ‘dst’

          Three or more alphanumerics giving the timezone abbreviations.
          These will be propagated into time.tzname

     ‘offset’

          The offset has the form: ‘± hh[:mm[:ss]]’.  This indicates the
          value added the local time to arrive at UTC. If preceded by a
          “-”, the timezone is east of the Prime Meridian; otherwise, it
          is west.  If no offset follows dst, summer time is assumed to
          be one hour ahead of standard time.

     ‘start[/time], end[/time]’

          Indicates when to change to and back from DST. The format of
          the start and end dates are one of the following:

          ‘JN’

               The Julian day 'n' (1 <= 'n' <= 365).  Leap days are not
               counted, so in all years February 28 is day 59 and March
               1 is day 60.

          ‘N’

               The zero-based Julian day (0 <= 'n' <= 365).  Leap days
               are counted, and it is possible to refer to February 29.

          ‘MM.N.D’

               The 'd'’th day (0 <= 'd' <= 6) of week 'n' of month 'm'
               of the year (1 <= 'n' <= 5, 1 <= 'm' <= 12, where week 5
               means «the last 'd' day in month 'm'» which may occur in
               either the fourth or the fifth week).  Week 1 is the
               first week in which the 'd'’th day occurs.  Day zero is a
               Sunday.

          ‘time’ has the same format as ‘offset’ except that no leading
          sign (“-” or “+”) is allowed.  The default, if time is not
          given, is 02:00:00.

          >>> os.environ['TZ'] = 'EST+05EDT,M4.1.0,M10.5.0'
          >>> time.tzset()
          >>> time.strftime('%X %x %Z')
          '02:07:36 05/08/03 EDT'
          >>> os.environ['TZ'] = 'AEST-10AEDT-11,M10.5.0,M3.5.0'
          >>> time.tzset()
          >>> time.strftime('%X %x %Z')
          '16:08:12 05/08/03 AEST'

     On many Unix systems (including *BSD, Linux, Solaris, and Darwin),
     it is more convenient to use the system’s zoneinfo
     (‘tzfile(5)(12)’) database to specify the timezone rules.  To do
     this, set the ‘TZ’ environment variable to the path of the required
     timezone datafile, relative to the root of the systems “zoneinfo”
     timezone database, usually located at ‘/usr/share/zoneinfo’.  For
     example, ‘'US/Eastern'’, ‘'Australia/Melbourne'’, ‘'Egypt'’ or
     ‘'Europe/Amsterdam'’.

          >>> os.environ['TZ'] = 'US/Eastern'
          >>> time.tzset()
          >>> time.tzname
          ('EST', 'EDT')
          >>> os.environ['TZ'] = 'Egypt'
          >>> time.tzset()
          >>> time.tzname
          ('EET', 'EEST')

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/pthread_getcpuclockid(3)

   (2) 
https://learn.microsoft.com/windows/win32/api/synchapi/nf-synchapi-createwaitabletimerexw

   (3) https://peps.python.org/pep-0475/

   (4) The use of ‘%Z’ is now deprecated, but the ‘%z’ escape that
expands to the preferred hour/minute offset is not supported by all ANSI
C libraries.  Also, a strict reading of the original 1982 RFC 822
(https://datatracker.ietf.org/doc/html/rfc822.html) standard calls for a
two-digit year (‘%y’ rather than ‘%Y’), but practice moved to 4-digit
years long before the year 2000.  After that, RFC 822
(https://datatracker.ietf.org/doc/html/rfc822.html) became obsolete and
the 4-digit year has been first recommended by RFC 1123
(https://datatracker.ietf.org/doc/html/rfc1123.html) and then mandated
by RFC 2822 (https://datatracker.ietf.org/doc/html/rfc2822.html), with
RFC 5322 (https://datatracker.ietf.org/doc/html/rfc5322.html) continuing
this requirement.

   (5) The use of ‘%Z’ is now deprecated, but the ‘%z’ escape that
expands to the preferred hour/minute offset is not supported by all ANSI
C libraries.  Also, a strict reading of the original 1982 RFC 822
(https://datatracker.ietf.org/doc/html/rfc822.html) standard calls for a
two-digit year (‘%y’ rather than ‘%Y’), but practice moved to 4-digit
years long before the year 2000.  After that, RFC 822
(https://datatracker.ietf.org/doc/html/rfc822.html) became obsolete and
the 4-digit year has been first recommended by RFC 1123
(https://datatracker.ietf.org/doc/html/rfc1123.html) and then mandated
by RFC 2822 (https://datatracker.ietf.org/doc/html/rfc2822.html), with
RFC 5322 (https://datatracker.ietf.org/doc/html/rfc5322.html) continuing
this requirement.

   (6) https://en.wikipedia.org/wiki/Leap_second

   (7) https://datatracker.ietf.org/doc/html/rfc5322.html

   (8) The use of ‘%Z’ is now deprecated, but the ‘%z’ escape that
expands to the preferred hour/minute offset is not supported by all ANSI
C libraries.  Also, a strict reading of the original 1982 RFC 822
(https://datatracker.ietf.org/doc/html/rfc822.html) standard calls for a
two-digit year (‘%y’ rather than ‘%Y’), but practice moved to 4-digit
years long before the year 2000.  After that, RFC 822
(https://datatracker.ietf.org/doc/html/rfc822.html) became obsolete and
the 4-digit year has been first recommended by RFC 1123
(https://datatracker.ietf.org/doc/html/rfc1123.html) and then mandated
by RFC 2822 (https://datatracker.ietf.org/doc/html/rfc2822.html), with
RFC 5322 (https://datatracker.ietf.org/doc/html/rfc5322.html) continuing
this requirement.

   (9) https://manpages.debian.org/strftime(3)

   (10) https://en.wikipedia.org/wiki/Leap_second

   (11) https://en.wikipedia.org/wiki/Unix_time

   (12) https://manpages.debian.org/tzfile(5)


File: python.info,  Node: Clock ID Constants,  Next: Timezone Constants,  Prev: Functions<4>,  Up: time — Time access and conversions

5.16.3.2 Clock ID Constants
...........................

These constants are used as parameters for *note clock_getres(): 1365.
and *note clock_gettime(): 1366.

 -- Dati: time.CLOCK_BOOTTIME

     Identical to *note CLOCK_MONOTONIC: 8a9, except it also includes
     any time that the system is suspended.

     This allows applications to get a suspend-aware monotonic clock
     without having to deal with the complications of *note
     CLOCK_REALTIME: 8aa, which may have discontinuities if the time is
     changed using ‘settimeofday()’ or similar.

     *note Availability: 2128.: Linux >= 2.6.39.

     Added in version 3.7.

 -- Dati: time.CLOCK_HIGHRES

     The Solaris OS has a ‘CLOCK_HIGHRES’ timer that attempts to use an
     optimal hardware source, and may give close to nanosecond
     resolution.  ‘CLOCK_HIGHRES’ is the nonadjustable, high-resolution
     clock.

     *note Availability: 2128.: Solaris.

     Added in version 3.3.

 -- Dati: time.CLOCK_MONOTONIC

     Clock that cannot be set and represents monotonic time since some
     unspecified starting point.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Dati: time.CLOCK_MONOTONIC_RAW

     Similar to *note CLOCK_MONOTONIC: 8a9, but provides access to a raw
     hardware-based time that is not subject to NTP adjustments.

     *note Availability: 2128.: Linux >= 2.6.28, macOS >= 10.12.

     Added in version 3.3.

 -- Dati: time.CLOCK_MONOTONIC_RAW_APPROX

     Similar to *note CLOCK_MONOTONIC_RAW: 3128, but reads a value
     cached by the system at context switch and hence has less accuracy.

     *note Availability: 2128.: macOS >= 10.12.

     Added in version 3.13.

 -- Dati: time.CLOCK_PROCESS_CPUTIME_ID

     High-resolution per-process timer from the CPU.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Dati: time.CLOCK_PROF

     High-resolution per-process timer from the CPU.

     *note Availability: 2128.: FreeBSD, NetBSD >= 7, OpenBSD.

     Added in version 3.7.

 -- Dati: time.CLOCK_TAI

     International Atomic Time(1)

     The system must have a current leap second table in order for this
     to give the correct answer.  PTP or NTP software can maintain a
     leap second table.

     *note Availability: 2128.: Linux.

     Added in version 3.9.

 -- Dati: time.CLOCK_THREAD_CPUTIME_ID

     Thread-specific CPU-time clock.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

 -- Dati: time.CLOCK_UPTIME

     Time whose absolute value is the time the system has been running
     and not suspended, providing accurate uptime measurement, both
     absolute and interval.

     *note Availability: 2128.: FreeBSD, OpenBSD >= 5.5.

     Added in version 3.7.

 -- Dati: time.CLOCK_UPTIME_RAW

     Clock that increments monotonically, tracking the time since an
     arbitrary point, unaffected by frequency or time adjustments and
     not incremented while the system is asleep.

     *note Availability: 2128.: macOS >= 10.12.

     Added in version 3.8.

 -- Dati: time.CLOCK_UPTIME_RAW_APPROX

     Like *note CLOCK_UPTIME_RAW: c39, but the value is cached by the
     system at context switches and therefore has less accuracy.

     *note Availability: 2128.: macOS >= 10.12.

     Added in version 3.13.

The following constant is the only parameter that can be sent to *note
clock_settime(): 1367.

 -- Dati: time.CLOCK_REALTIME

     Real-time clock.  Setting this clock requires appropriate
     privileges.  The clock is the same for all processes.

     *note Availability: 2128.: Unix.

     Added in version 3.3.

   ---------- Footnotes ----------

   (1) 
https://www.nist.gov/pml/time-and-frequency-division/how-utcnist-related-coordinated-universal-time-utc-international


File: python.info,  Node: Timezone Constants,  Prev: Clock ID Constants,  Up: time — Time access and conversions

5.16.3.3 Timezone Constants
...........................

 -- Dati: time.altzone

     The offset of the local DST timezone, in seconds west of UTC, if
     one is defined.  This is negative if the local DST timezone is east
     of UTC (as in Western Europe, including the UK). Only use this if
     ‘daylight’ is nonzero.  See note below.

 -- Dati: time.daylight

     Nonzero if a DST timezone is defined.  See note below.

 -- Dati: time.timezone

     The offset of the local (non-DST) timezone, in seconds west of UTC
     (negative in most of Western Europe, positive in the US, zero in
     the UK). See note below.

 -- Dati: time.tzname

     A tuple of two strings: the first is the name of the local non-DST
     timezone, the second is the name of the local DST timezone.  If no
     DST timezone is defined, the second string should not be used.  See
     note below.

     Nota: For the above Timezone constants (*note altzone: 312f, *note
     daylight: 3130, *note timezone: 3131, and *note tzname: 3132.), the
     value is determined by the timezone rules in effect at module load
     time or the last time *note tzset(): 3125. is called and may be
     incorrect for times in the past.  It is recommended to use the
     *note tm_gmtoff: 3118. and *note tm_zone: 3119. results from *note
     localtime(): 1700. to obtain timezone information.

Vedi anche
..........

Module *note datetime: 34.

     More object-oriented interface to dates and times.

Module *note locale: 8a.

     Internationalization services.  The locale setting affects the
     interpretation of many format specifiers in *note strftime(): 13f1.
     and *note strptime(): 1634.

Module *note calendar: 15.

     General calendar-related functions.  *note timegm(): 292c. is the
     inverse of *note gmtime(): 13c8. from this module.


File: python.info,  Node: logging — Logging facility for Python,  Next: logging config — Logging configuration,  Prev: time — Time access and conversions,  Up: Generic Operating System Services

5.16.4 ‘logging’ — Logging facility for Python
----------------------------------------------

'Source code:' Lib/logging/__init__.py(1)

Important
.........

This page contains the API reference information.  For tutorial
information and discussion of more advanced topics, see

   * *note Basic Tutorial: 13fd.

   * *note Advanced Tutorial: 13fe.

   * *note Logging Cookbook: 13ff.

__________________________________________________________________

This module defines functions and classes which implement a flexible
event logging system for applications and libraries.

The key benefit of having the logging API provided by a standard library
module is that all Python modules can participate in logging, so your
application log can include your own messages integrated with messages
from third-party modules.

Here’s a simple example of idiomatic usage:

     # myapp.py
     import logging
     import mylib
     logger = logging.getLogger(__name__)

     def main():
         logging.basicConfig(filename='myapp.log', level=logging.INFO)
         logger.info('Started')
         mylib.do_something()
         logger.info('Finished')

     if __name__ == '__main__':
         main()

     # mylib.py
     import logging
     logger = logging.getLogger(__name__)

     def do_something():
         logger.info('Doing something')

If you run 'myapp.py', you should see this in 'myapp.log':

     INFO:__main__:Started
     INFO:mylib:Doing something
     INFO:__main__:Finished

The key feature of this idiomatic usage is that the majority of code is
simply creating a module level logger with ‘getLogger(__name__)’, and
using that logger to do any needed logging.  This is concise, while
allowing downstream code fine-grained control if needed.  Logged
messages to the module-level logger get forwarded to handlers of loggers
in higher-level modules, all the way up to the highest-level logger
known as the root logger; this approach is known as hierarchical
logging.

For logging to be useful, it needs to be configured: setting the levels
and destinations for each logger, potentially changing how specific
modules log, often based on command-line arguments or application
configuration.  In most cases, like the one above, only the root logger
needs to be so configured, since all the lower level loggers at module
level eventually forward their messages to its handlers.  *note
basicConfig(): bf5. provides a quick way to configure the root logger
that handles many use cases.

The module provides a lot of functionality and flexibility.  If you are
unfamiliar with logging, the best way to get to grips with it is to view
the tutorials ('see the links above and on the right').

The basic classes defined by the module, together with their attributes
and methods, are listed in the sections below.

   * Loggers expose the interface that application code directly uses.

   * Handlers send the log records (created by loggers) to the
     appropriate destination.

   * Filters provide a finer grained facility for determining which log
     records to output.

   * Formatters specify the layout of log records in the final output.

* Menu:

* Logger Objects::
* Logging Levels::
* Handler Objects::
* Formatter Objects::
* Filter Objects::
* LogRecord Objects::
* LogRecord attributes::
* LoggerAdapter Objects::
* Thread Safety::
* Module-Level Functions::
* Module-Level Attributes::
* Integration with the warnings module::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/logging/__init__.py


File: python.info,  Node: Logger Objects,  Next: Logging Levels,  Up: logging — Logging facility for Python

5.16.4.1 Logger Objects
.......................

Loggers have the following attributes and methods.  Note that Loggers
should 'NEVER' be instantiated directly, but always through the
module-level function ‘logging.getLogger(name)’.  Multiple calls to
*note getLogger(): b5b. with the same name will always return a
reference to the same Logger object.

The ‘name’ is potentially a period-separated hierarchical value, like
‘foo.bar.baz’ (though it could also be just plain ‘foo’, for example).
Loggers that are further down in the hierarchical list are children of
loggers higher up in the list.  For example, given a logger with a name
of ‘foo’, loggers with names of ‘foo.bar’, ‘foo.bar.baz’, and ‘foo.bam’
are all descendants of ‘foo’.  In addition, all loggers are descendants
of the root logger.  The logger name hierarchy is analogous to the
Python package hierarchy, and identical to it if you organise your
loggers on a per-module basis using the recommended construction
‘logging.getLogger(__name__)’.  That’s because in a module, ‘__name__’
is the module’s name in the Python package namespace.

 -- Classe: logging.Logger

      -- Attributo: name

          This is the logger’s name, and is the value that was passed to
          *note getLogger(): b5b. to obtain the logger.

               Nota: This attribute should be treated as read-only.

      -- Attributo: level

          The threshold of this logger, as set by the *note setLevel():
          169a. method.

               Nota: Do not set this attribute directly - always use
               *note setLevel(): 169a, which has checks for the level
               passed to it.

      -- Attributo: parent

          The parent logger of this logger.  It may change based on
          later instantiation of loggers which are higher up in the
          namespace hierarchy.

               Nota: This value should be treated as read-only.

      -- Attributo: propagate

          If this attribute evaluates to true, events logged to this
          logger will be passed to the handlers of higher level
          (ancestor) loggers, in addition to any handlers attached to
          this logger.  Messages are passed directly to the ancestor
          loggers” handlers - neither the level nor filters of the
          ancestor loggers in question are considered.

          If this evaluates to false, logging messages are not passed to
          the handlers of ancestor loggers.

          Spelling it out with an example: If the propagate attribute of
          the logger named ‘A.B.C’ evaluates to true, any event logged
          to ‘A.B.C’ via a method call such as
          ‘logging.getLogger('A.B.C').error(...)’ will [subject to
          passing that logger’s level and filter settings] be passed in
          turn to any handlers attached to loggers named ‘A.B’, ‘A’ and
          the root logger, after first being passed to any handlers
          attached to ‘A.B.C’.  If any logger in the chain ‘A.B.C’,
          ‘A.B’, ‘A’ has its ‘propagate’ attribute set to false, then
          that is the last logger whose handlers are offered the event
          to handle, and propagation stops at that point.

          The constructor sets this attribute to ‘True’.

               Nota: If you attach a handler to a logger 'and' one or
               more of its ancestors, it may emit the same record
               multiple times.  In general, you should not need to
               attach a handler to more than one logger - if you just
               attach it to the appropriate logger which is highest in
               the logger hierarchy, then it will see all events logged
               by all descendant loggers, provided that their propagate
               setting is left set to ‘True’.  A common scenario is to
               attach handlers only to the root logger, and to let
               propagation take care of the rest.

      -- Attributo: handlers

          The list of handlers directly attached to this logger
          instance.

               Nota: This attribute should be treated as read-only; it
               is normally changed via the *note addHandler(): 313c. and
               *note removeHandler(): 313d. methods, which use locks to
               ensure thread-safe operation.

      -- Attributo: disabled

          This attribute disables handling of any events.  It is set to
          ‘False’ in the initializer, and only changed by logging
          configuration code.

               Nota: This attribute should be treated as read-only.

      -- Metodo: setLevel (level)

          Sets the threshold for this logger to 'level'.  Logging
          messages which are less severe than 'level' will be ignored;
          logging messages which have severity 'level' or higher will be
          emitted by whichever handler or handlers service this logger,
          unless a handler’s level has been set to a higher severity
          level than 'level'.

          When a logger is created, the level is set to *note NOTSET:
          313f. (which causes all messages to be processed when the
          logger is the root logger, or delegation to the parent when
          the logger is a non-root logger).  Note that the root logger
          is created with level *note WARNING: 20c9.

          The term “delegation to the parent” means that if a logger has
          a level of NOTSET, its chain of ancestor loggers is traversed
          until either an ancestor with a level other than NOTSET is
          found, or the root is reached.

          If an ancestor is found with a level other than NOTSET, then
          that ancestor’s level is treated as the effective level of the
          logger where the ancestor search began, and is used to
          determine how a logging event is handled.

          If the root is reached, and it has a level of NOTSET, then all
          messages will be processed.  Otherwise, the root’s level will
          be used as the effective level.

          See *note Logging Levels: 86b. for a list of levels.

          Cambiato nella versione 3.2: The 'level' parameter now accepts
          a string representation of the level such as “INFO” as an
          alternative to the integer constants such as *note INFO: 20c8.
          Note, however, that levels are internally stored as integers,
          and methods such as e.g.  *note getEffectiveLevel(): 3140. and
          *note isEnabledFor(): 14fe. will return/expect to be passed
          integers.

      -- Metodo: isEnabledFor (level)

          Indicates if a message of severity 'level' would be processed
          by this logger.  This method checks first the module-level
          level set by ‘logging.disable(level)’ and then the logger’s
          effective level as determined by *note getEffectiveLevel():
          3140.

      -- Metodo: getEffectiveLevel ()

          Indicates the effective level for this logger.  If a value
          other than *note NOTSET: 313f. has been set using *note
          setLevel(): 169a, it is returned.  Otherwise, the hierarchy is
          traversed towards the root until a value other than *note
          NOTSET: 313f. is found, and that value is returned.  The value
          returned is an integer, typically one of *note logging.DEBUG:
          20c7, *note logging.INFO: 20c8. etc.

      -- Metodo: getChild (suffix)

          Returns a logger which is a descendant to this logger, as
          determined by the suffix.  Thus,
          ‘logging.getLogger('abc').getChild('def.ghi')’ would return
          the same logger as would be returned by
          ‘logging.getLogger('abc.def.ghi')’.  This is a convenience
          method, useful when the parent logger is named using e.g.
          ‘__name__’ rather than a literal string.

          Added in version 3.2.

      -- Metodo: getChildren ()

          Returns a set of loggers which are immediate children of this
          logger.  So for example ‘logging.getLogger().getChildren()’
          might return a set containing loggers named ‘foo’ and ‘bar’,
          but a logger named ‘foo.bar’ wouldn’t be included in the set.
          Likewise, ‘logging.getLogger('foo').getChildren()’ might
          return a set including a logger named ‘foo.bar’, but it
          wouldn’t include one named ‘foo.bar.baz’.

          Added in version 3.12.

      -- Metodo: debug (msg, *args, **kwargs)

          Logs a message with level *note DEBUG: 20c7. on this logger.
          The 'msg' is the message format string, and the 'args' are the
          arguments which are merged into 'msg' using the string
          formatting operator.  (Note that this means that you can use
          keywords in the format string, together with a single
          dictionary argument.)  No % formatting operation is performed
          on 'msg' when no 'args' are supplied.

          There are four keyword arguments in 'kwargs' which are
          inspected: 'exc_info', 'stack_info', 'stacklevel' and 'extra'.

          If 'exc_info' does not evaluate as false, it causes exception
          information to be added to the logging message.  If an
          exception tuple (in the format returned by *note
          sys.exc_info(): 89b.) or an exception instance is provided, it
          is used; otherwise, *note sys.exc_info(): 89b. is called to
          get the exception information.

          The second optional keyword argument is 'stack_info', which
          defaults to ‘False’.  If true, stack information is added to
          the logging message, including the actual logging call.  Note
          that this is not the same stack information as that displayed
          through specifying 'exc_info': The former is stack frames from
          the bottom of the stack up to the logging call in the current
          thread, whereas the latter is information about stack frames
          which have been unwound, following an exception, while
          searching for exception handlers.

          You can specify 'stack_info' independently of 'exc_info', e.g.
          to just show how you got to a certain point in your code, even
          when no exceptions were raised.  The stack frames are printed
          following a header line which says:

               Stack (most recent call last):

          This mimics the ‘Traceback (most recent call last):’ which is
          used when displaying exception frames.

          The third optional keyword argument is 'stacklevel', which
          defaults to ‘1’.  If greater than 1, the corresponding number
          of stack frames are skipped when computing the line number and
          function name set in the *note LogRecord: 11e8. created for
          the logging event.  This can be used in logging helpers so
          that the function name, filename and line number recorded are
          not the information for the helper function/method, but rather
          its caller.  The name of this parameter mirrors the equivalent
          one in the *note warnings: 118. module.

          The fourth keyword argument is 'extra' which can be used to
          pass a dictionary which is used to populate the *note
          __dict__: 77e. of the *note LogRecord: 11e8. created for the
          logging event with user-defined attributes.  These custom
          attributes can then be used as you like.  For example, they
          could be incorporated into logged messages.  For example:

               FORMAT = '%(asctime)s %(clientip)-15s %(user)-8s %(message)s'
               logging.basicConfig(format=FORMAT)
               d = {'clientip': '192.168.0.1', 'user': 'fbloggs'}
               logger = logging.getLogger('tcpserver')
               logger.warning('Protocol problem: %s', 'connection reset', extra=d)

          would print something like

               2006-02-08 22:20:02,165 192.168.0.1 fbloggs  Protocol problem: connection reset

          The keys in the dictionary passed in 'extra' should not clash
          with the keys used by the logging system.  (See the section on
          *note LogRecord attributes: 3141. for more information on
          which keys are used by the logging system.)

          If you choose to use these attributes in logged messages, you
          need to exercise some care.  In the above example, for
          instance, the *note Formatter: 169e. has been set up with a
          format string which expects “clientip” and “user” in the
          attribute dictionary of the *note LogRecord: 11e8.  If these
          are missing, the message will not be logged because a string
          formatting exception will occur.  So in this case, you always
          need to pass the 'extra' dictionary with these keys.

          While this might be annoying, this feature is intended for use
          in specialized circumstances, such as multi-threaded servers
          where the same code executes in many contexts, and interesting
          conditions which arise are dependent on this context (such as
          remote client IP address and authenticated user name, in the
          above example).  In such circumstances, it is likely that
          specialized *note Formatter: 169e.s would be used with
          particular *note Handler: 169d.s.

          If no handler is attached to this logger (or any of its
          ancestors, taking into account the relevant *note
          Logger.propagate: 169c. attributes), the message will be sent
          to the handler set on *note lastResort: 1402.

          Cambiato nella versione 3.2: The 'stack_info' parameter was
          added.

          Cambiato nella versione 3.5: The 'exc_info' parameter can now
          accept exception instances.

          Cambiato nella versione 3.8: The 'stacklevel' parameter was
          added.

      -- Metodo: info (msg, *args, **kwargs)

          Logs a message with level *note INFO: 20c8. on this logger.
          The arguments are interpreted as for *note debug(): 3143.

      -- Metodo: warning (msg, *args, **kwargs)

          Logs a message with level *note WARNING: 20c9. on this logger.
          The arguments are interpreted as for *note debug(): 3143.

               Nota: There is an obsolete method ‘warn’ which is
               functionally identical to ‘warning’.  As ‘warn’ is
               deprecated, please do not use it - use ‘warning’ instead.

      -- Metodo: error (msg, *args, **kwargs)

          Logs a message with level *note ERROR: 20ca. on this logger.
          The arguments are interpreted as for *note debug(): 3143.

      -- Metodo: critical (msg, *args, **kwargs)

          Logs a message with level *note CRITICAL: 20cb. on this
          logger.  The arguments are interpreted as for *note debug():
          3143.

      -- Metodo: log (level, msg, *args, **kwargs)

          Logs a message with integer level 'level' on this logger.  The
          other arguments are interpreted as for *note debug(): 3143.

      -- Metodo: exception (msg, *args, **kwargs)

          Logs a message with level *note ERROR: 20ca. on this logger.
          The arguments are interpreted as for *note debug(): 3143.
          Exception info is added to the logging message.  This method
          should only be called from an exception handler.

      -- Metodo: addFilter (filter)

          Adds the specified filter 'filter' to this logger.

      -- Metodo: removeFilter (filter)

          Removes the specified filter 'filter' from this logger.

      -- Metodo: filter (record)

          Apply this logger’s filters to the record and return ‘True’ if
          the record is to be processed.  The filters are consulted in
          turn, until one of them returns a false value.  If none of
          them return a false value, the record will be processed
          (passed to handlers).  If one returns a false value, no
          further processing of the record occurs.

      -- Metodo: addHandler (hdlr)

          Adds the specified handler 'hdlr' to this logger.

      -- Metodo: removeHandler (hdlr)

          Removes the specified handler 'hdlr' from this logger.

      -- Metodo: findCaller (stack_info=False, stacklevel=1)

          Finds the caller’s source filename and line number.  Returns
          the filename, line number, function name and stack information
          as a 4-element tuple.  The stack information is returned as
          ‘None’ unless 'stack_info' is ‘True’.

          The 'stacklevel' parameter is passed from code calling the
          *note debug(): 3143. and other APIs.  If greater than 1, the
          excess is used to skip stack frames before determining the
          values to be returned.  This will generally be useful when
          calling logging APIs from helper/wrapper code, so that the
          information in the event log refers not to the helper/wrapper
          code, but to the code that calls it.

      -- Metodo: handle (record)

          Handles a record by passing it to all handlers associated with
          this logger and its ancestors (until a false value of
          'propagate' is found).  This method is used for unpickled
          records received from a socket, as well as those created
          locally.  Logger-level filtering is applied using *note
          filter(): 3147.

      -- Metodo: makeRecord (name, level, fn, lno, msg, args, exc_info,
               func=None, extra=None, sinfo=None)

          This is a factory method which can be overridden in subclasses
          to create specialized *note LogRecord: 11e8. instances.

      -- Metodo: hasHandlers ()

          Checks to see if this logger has any handlers configured.
          This is done by looking for handlers in this logger and its
          parents in the logger hierarchy.  Returns ‘True’ if a handler
          was found, else ‘False’.  The method stops searching up the
          hierarchy whenever a logger with the “propagate” attribute set
          to false is found - that will be the last logger which is
          checked for the existence of handlers.

          Added in version 3.2.

     Cambiato nella versione 3.7: Loggers can now be pickled and
     unpickled.


File: python.info,  Node: Logging Levels,  Next: Handler Objects,  Prev: Logger Objects,  Up: logging — Logging facility for Python

5.16.4.2 Logging Levels
.......................

The numeric values of logging levels are given in the following table.
These are primarily of interest if you want to define your own levels,
and need them to have specific values relative to the predefined levels.
If you define a level with the same numeric value, it overwrites the
predefined value; the predefined name is lost.

Level                       Numeric value       What it means / When to use it
                                                
------------------------------------------------------------------------------------------
                                                
 -- Dati: logging.NOTSET    0                   When set on a logger, indicates that
                                                ancestor loggers are to be consulted to
                                                determine the effective level.  If that
                                                still resolves to ‘NOTSET’, then all
                                                events are logged.  When set on a
                                                handler, all events are handled.
                                                
                                                
 -- Dati: logging.DEBUG     10                  Detailed information, typically only of
                                                interest to a developer trying to
                                                diagnose a problem.
                                                
                                                
 -- Dati: logging.INFO      20                  Confirmation that things are working as
                                                expected.
                                                
                                                
 -- Dati: logging.WARNING   30                  An indication that something unexpected
                                                happened, or that a problem might occur
                                                in the near future (e.g.  “disk space
                                                low”).  The software is still working
                                                as expected.
                                                
                                                
 -- Dati: logging.ERROR     40                  Due to a more serious problem, the
                                                software has not been able to perform
                                                some function.
                                                
                                                
 -- Dati:                   50                  A serious error, indicating that the
          logging.CRITICAL                      program itself may be unable to
                                                continue running.
                                                


File: python.info,  Node: Handler Objects,  Next: Formatter Objects,  Prev: Logging Levels,  Up: logging — Logging facility for Python

5.16.4.3 Handler Objects
........................

Handlers have the following attributes and methods.  Note that *note
Handler: 169d. is never instantiated directly; this class acts as a base
for more useful subclasses.  However, the ‘__init__()’ method in
subclasses needs to call *note Handler.__init__(): 314f.

 -- Classe: logging.Handler

      -- Metodo: __init__ (level=NOTSET)

          Initializes the *note Handler: 169d. instance by setting its
          level, setting the list of filters to the empty list and
          creating a lock (using *note createLock(): 3150.) for
          serializing access to an I/O mechanism.

      -- Metodo: createLock ()

          Initializes a thread lock which can be used to serialize
          access to underlying I/O functionality which may not be
          threadsafe.

      -- Metodo: acquire ()

          Acquires the thread lock created with *note createLock():
          3150.

      -- Metodo: release ()

          Releases the thread lock acquired with *note acquire(): 3151.

      -- Metodo: setLevel (level)

          Sets the threshold for this handler to 'level'.  Logging
          messages which are less severe than 'level' will be ignored.
          When a handler is created, the level is set to *note NOTSET:
          313f. (which causes all messages to be processed).

          See *note Logging Levels: 86b. for a list of levels.

          Cambiato nella versione 3.2: The 'level' parameter now accepts
          a string representation of the level such as “INFO” as an
          alternative to the integer constants such as *note INFO: 20c8.

      -- Metodo: setFormatter (fmt)

          Sets the formatter for this handler to 'fmt'.  The 'fmt'
          argument must be a *note Formatter: 169e. instance or ‘None’.

      -- Metodo: addFilter (filter)

          Adds the specified filter 'filter' to this handler.

      -- Metodo: removeFilter (filter)

          Removes the specified filter 'filter' from this handler.

      -- Metodo: filter (record)

          Apply this handler’s filters to the record and return ‘True’
          if the record is to be processed.  The filters are consulted
          in turn, until one of them returns a false value.  If none of
          them return a false value, the record will be emitted.  If one
          returns a false value, the handler will not emit the record.

      -- Metodo: flush ()

          Ensure all logging output has been flushed.  This version does
          nothing and is intended to be implemented by subclasses.

      -- Metodo: close ()

          Tidy up any resources used by the handler.  This version does
          no output but removes the handler from an internal map of
          handlers, which is used for handler lookup by name.

          Subclasses should ensure that this gets called from overridden
          *note close(): 3159. methods.

      -- Metodo: handle (record)

          Conditionally emits the specified logging record, depending on
          filters which may have been added to the handler.  Wraps the
          actual emission of the record with acquisition/release of the
          I/O thread lock.

      -- Metodo: handleError (record)

          This method should be called from handlers when an exception
          is encountered during an *note emit(): 315c. call.  If the
          module-level attribute *note raiseExceptions: 1401. is
          ‘False’, exceptions get silently ignored.  This is what is
          mostly wanted for a logging system - most users will not care
          about errors in the logging system, they are more interested
          in application errors.  You could, however, replace this with
          a custom handler if you wish.  The specified record is the one
          which was being processed when the exception occurred.  (The
          default value of *note raiseExceptions: 1401. is ‘True’, as
          that is more useful during development).

      -- Metodo: format (record)

          Do formatting for a record - if a formatter is set, use it.
          Otherwise, use the default formatter for the module.

      -- Metodo: emit (record)

          Do whatever it takes to actually log the specified logging
          record.  This version is intended to be implemented by
          subclasses and so raises a *note NotImplementedError: 36b.

               Avvertimento: This method is called after a handler-level
               lock is acquired, which is released after this method
               returns.  When you override this method, note that you
               should be careful when calling anything that invokes
               other parts of the logging API which might do locking,
               because that might result in a deadlock.  Specifically:

                  * Logging configuration APIs acquire the module-level
                    lock, and then individual handler-level locks as
                    those handlers are configured.

                  * Many logging APIs lock the module-level lock.  If
                    such an API is called from this method, it could
                    cause a deadlock if a configuration call is made on
                    another thread, because that thread will try to
                    acquire the module-level lock 'before' the
                    handler-level lock, whereas this thread tries to
                    acquire the module-level lock 'after' the
                    handler-level lock (because in this method, the
                    handler-level lock has already been acquired).

For a list of handlers included as standard, see *note logging.handlers:
8d.


File: python.info,  Node: Formatter Objects,  Next: Filter Objects,  Prev: Handler Objects,  Up: logging — Logging facility for Python

5.16.4.4 Formatter Objects
..........................

 -- Classe: logging.Formatter (fmt=None, datefmt=None, style='%',
          validate=True, *, defaults=None)

     Responsible for converting a *note LogRecord: 11e8. to an output
     string to be interpreted by a human or external system.


     Parametri:

        * ‘fmt’ (*note str: 169.) – A format string in the given 'style'
          for the logged output as a whole.  The possible mapping keys
          are drawn from the *note LogRecord: 11e8. object’s *note
          LogRecord attributes: 3141.  If not specified, ‘'%(message)s'’
          is used, which is just the logged message.

        * ‘datefmt’ (*note str: 169.) – A format string for the
          date/time portion of the logged output.  If not specified, the
          default described in *note formatTime(): 3160. is used.

        * ‘style’ (*note str: 169.) – Can be one of ‘'%'’, ‘'{'’ or
          ‘'$'’ and determines how the format string will be merged with
          its data: using one of *note Formattazione delle stringhe in
          stile printf: 8dc. (‘%’), *note str.format(): 834. (‘{’) or
          *note string.Template: 898. (‘$’).  This only applies to 'fmt'
          (e.g.  ‘'%(message)s'’ versus ‘'{message}'’), not to the
          actual log messages passed to the logging methods.  However,
          there are *note other ways: 3161. to use ‘{’- and
          ‘$’-formatting for log messages.

        * ‘validate’ (*note bool: 3c3.) – If ‘True’ (the default),
          incorrect or mismatched 'fmt' and 'style' will raise a *note
          ValueError: 2ec.; for example, ‘logging.Formatter('%(asctime)s
          - %(message)s', style='{')’.

        * ‘defaults’ (*note dict: 183.‘[’*note str: 169.‘, ’‘Any’‘]’) –
          A dictionary with default values to use in custom fields.  For
          example, ‘logging.Formatter('%(ip)s %(message)s',
          defaults={"ip": None})’

     Cambiato nella versione 3.2: Added the 'style' parameter.

     Cambiato nella versione 3.8: Added the 'validate' parameter.

     Cambiato nella versione 3.10: Added the 'defaults' parameter.

      -- Metodo: format (record)

          The record’s attribute dictionary is used as the operand to a
          string formatting operation.  Returns the resulting string.
          Before formatting the dictionary, a couple of preparatory
          steps are carried out.  The 'message' attribute of the record
          is computed using 'msg' % 'args'.  If the formatting string
          contains ‘'(asctime)'’, *note formatTime(): 3160. is called to
          format the event time.  If there is exception information, it
          is formatted using *note formatException(): 3163. and appended
          to the message.  Note that the formatted exception information
          is cached in attribute 'exc_text'.  This is useful because the
          exception information can be pickled and sent across the wire,
          but you should be careful if you have more than one *note
          Formatter: 169e. subclass which customizes the formatting of
          exception information.  In this case, you will have to clear
          the cached value (by setting the 'exc_text' attribute to
          ‘None’) after a formatter has done its formatting, so that the
          next formatter to handle the event doesn’t use the cached
          value, but recalculates it afresh.

          If stack information is available, it’s appended after the
          exception information, using *note formatStack(): 3164. to
          transform it if necessary.

      -- Metodo: formatTime (record, datefmt=None)

          This method should be called from *note format(): 199. by a
          formatter which wants to make use of a formatted time.  This
          method can be overridden in formatters to provide for any
          specific requirement, but the basic behavior is as follows: if
          'datefmt' (a string) is specified, it is used with *note
          time.strftime(): 13f1. to format the creation time of the
          record.  Otherwise, the format “%Y-%m-%d %H:%M:%S,uuu” is
          used, where the uuu part is a millisecond value and the other
          letters are as per the *note time.strftime(): 13f1.
          documentation.  An example time in this format is ‘2003-01-23
          00:29:50,411’.  The resulting string is returned.

          This function uses a user-configurable function to convert the
          creation time to a tuple.  By default, *note time.localtime():
          1700. is used; to change this for a particular formatter
          instance, set the ‘converter’ attribute to a function with the
          same signature as *note time.localtime(): 1700. or *note
          time.gmtime(): 13c8.  To change it for all formatters, for
          example if you want all logging times to be shown in GMT, set
          the ‘converter’ attribute in the ‘Formatter’ class.

          Cambiato nella versione 3.3: Previously, the default format
          was hard-coded as in this example: ‘2010-09-06 22:38:15,292’
          where the part before the comma is handled by a strptime
          format string (‘'%Y-%m-%d %H:%M:%S'’), and the part after the
          comma is a millisecond value.  Because strptime does not have
          a format placeholder for milliseconds, the millisecond value
          is appended using another format string, ‘'%s,%03d'’ — and
          both of these format strings have been hardcoded into this
          method.  With the change, these strings are defined as
          class-level attributes which can be overridden at the instance
          level when desired.  The names of the attributes are
          ‘default_time_format’ (for the strptime format string) and
          ‘default_msec_format’ (for appending the millisecond value).

          Cambiato nella versione 3.9: The ‘default_msec_format’ can be
          ‘None’.

      -- Metodo: formatException (exc_info)

          Formats the specified exception information (a standard
          exception tuple as returned by *note sys.exc_info(): 89b.) as
          a string.  This default implementation just uses *note
          traceback.print_exception(): a51.  The resulting string is
          returned.

      -- Metodo: formatStack (stack_info)

          Formats the specified stack information (a string as returned
          by *note traceback.print_stack(): 1088, but with the last
          newline removed) as a string.  This default implementation
          just returns the input value.

 -- Classe: logging.BufferingFormatter (linefmt=None)

     A base formatter class suitable for subclassing when you want to
     format a number of records.  You can pass a *note Formatter: 169e.
     instance which you want to use to format each line (that
     corresponds to a single record).  If not specified, the default
     formatter (which just outputs the event message) is used as the
     line formatter.

      -- Metodo: formatHeader (records)

          Return a header for a list of 'records'.  The base
          implementation just returns the empty string.  You will need
          to override this method if you want specific behaviour, e.g.
          to show the count of records, a title or a separator line.

      -- Metodo: formatFooter (records)

          Return a footer for a list of 'records'.  The base
          implementation just returns the empty string.  You will need
          to override this method if you want specific behaviour, e.g.
          to show the count of records or a separator line.

      -- Metodo: format (records)

          Return formatted text for a list of 'records'.  The base
          implementation just returns the empty string if there are no
          records; otherwise, it returns the concatenation of the
          header, each record formatted with the line formatter, and the
          footer.


File: python.info,  Node: Filter Objects,  Next: LogRecord Objects,  Prev: Formatter Objects,  Up: logging — Logging facility for Python

5.16.4.5 Filter Objects
.......................

‘Filters’ can be used by ‘Handlers’ and ‘Loggers’ for more sophisticated
filtering than is provided by levels.  The base filter class only allows
events which are below a certain point in the logger hierarchy.  For
example, a filter initialized with “A.B” will allow events logged by
loggers “A.B”, “A.B.C”, “A.B.C.D”, “A.B.D” etc.  but not “A.BB”, “B.A.B”
etc.  If initialized with the empty string, all events are passed.

 -- Classe: logging.Filter (name='')

     Returns an instance of the *note Filter: 1403. class.  If 'name' is
     specified, it names a logger which, together with its children,
     will have its events allowed through the filter.  If 'name' is the
     empty string, allows every event.

      -- Metodo: filter (record)

          Is the specified record to be logged?  Returns false for no,
          true for yes.  Filters can either modify log records in-place
          or return a completely different record instance which will
          replace the original log record in any future processing of
          the event.

Note that filters attached to handlers are consulted before an event is
emitted by the handler, whereas filters attached to loggers are
consulted whenever an event is logged (using *note debug(): 3143, *note
info(): 316c, etc.), before sending an event to handlers.  This means
that events which have been generated by descendant loggers will not be
filtered by a logger’s filter setting, unless the filter has also been
applied to those descendant loggers.

You don’t actually need to subclass ‘Filter’: you can pass any instance
which has a ‘filter’ method with the same semantics.

Cambiato nella versione 3.2: You don’t need to create specialized
‘Filter’ classes, or use other classes with a ‘filter’ method: you can
use a function (or other callable) as a filter.  The filtering logic
will check to see if the filter object has a ‘filter’ attribute: if it
does, it’s assumed to be a ‘Filter’ and its *note filter(): 316b. method
is called.  Otherwise, it’s assumed to be a callable and called with the
record as the single parameter.  The returned value should conform to
that returned by *note filter(): 316b.

Cambiato nella versione 3.12: You can now return a *note LogRecord:
11e8. instance from filters to replace the log record rather than
modifying it in place.  This allows filters attached to a *note Handler:
169d. to modify the log record before it is emitted, without having side
effects on other handlers.

Although filters are used primarily to filter records based on more
sophisticated criteria than levels, they get to see every record which
is processed by the handler or logger they’re attached to: this can be
useful if you want to do things like counting how many records were
processed by a particular logger or handler, or adding, changing or
removing attributes in the *note LogRecord: 11e8. being processed.
Obviously changing the LogRecord needs to be done with some care, but it
does allow the injection of contextual information into logs (see *note
Using Filters to impart contextual information: 316d.).


File: python.info,  Node: LogRecord Objects,  Next: LogRecord attributes,  Prev: Filter Objects,  Up: logging — Logging facility for Python

5.16.4.6 LogRecord Objects
..........................

*note LogRecord: 11e8. instances are created automatically by the *note
Logger: d48. every time something is logged, and can be created manually
via *note makeLogRecord(): 3170. (for example, from a pickled event
received over the wire).

 -- Classe: logging.LogRecord (name, level, pathname, lineno, msg, args,
          exc_info, func=None, sinfo=None)

     Contains all the information pertinent to the event being logged.

     The primary information is passed in 'msg' and 'args', which are
     combined using ‘msg % args’ to create the ‘message’ attribute of
     the record.


     Parametri:

        * ‘name’ (*note str: 169.) – The name of the logger used to log
          the event represented by this ‘LogRecord’.  Note that the
          logger name in the ‘LogRecord’ will always have this value,
          even though it may be emitted by a handler attached to a
          different (ancestor) logger.

        * ‘level’ (*note int: 19b.) – The *note numeric level: 86b. of
          the logging event (such as ‘10’ for ‘DEBUG’, ‘20’ for ‘INFO’,
          etc).  Note that this is converted to 'two' attributes of the
          LogRecord: ‘levelno’ for the numeric value and ‘levelname’ for
          the corresponding level name.

        * ‘pathname’ (*note str: 169.) – The full string path of the
          source file where the logging call was made.

        * ‘lineno’ (*note int: 19b.) – The line number in the source
          file where the logging call was made.

        * ‘msg’ (*note Any: 8bc.) – The event description message, which
          can be a %-format string with placeholders for variable data,
          or an arbitrary object (see *note Using arbitrary objects as
          messages: 3171.).

        * ‘args’ (*note tuple: 614.‘ | ’*note dict: 183.‘[’*note str:
          169.‘, ’*note Any: 8bc.‘]’) – Variable data to merge into the
          'msg' argument to obtain the event description.

        * ‘exc_info’ (*note tuple: 614.‘[’*note type: f46.‘[’*note
          BaseException: 7d8.‘]’‘, ’*note BaseException: 7d8.‘, ’*note
          types.TracebackType: cec.‘] ’‘| ’‘None’) – An exception tuple
          with the current exception information, as returned by *note
          sys.exc_info(): 89b, or ‘None’ if no exception information is
          available.

        * ‘func’ (*note str: 169.‘ | ’‘None’) – The name of the function
          or method from which the logging call was invoked.

        * ‘sinfo’ (*note str: 169.‘ | ’‘None’) – A text string
          representing stack information from the base of the stack in
          the current thread, up to the logging call.

      -- Metodo: getMessage ()

          Returns the message for this *note LogRecord: 11e8. instance
          after merging any user-supplied arguments with the message.
          If the user-supplied message argument to the logging call is
          not a string, *note str(): 169. is called on it to convert it
          to a string.  This allows use of user-defined classes as
          messages, whose ‘__str__’ method can return the actual format
          string to be used.

     Cambiato nella versione 3.2: The creation of a *note LogRecord:
     11e8. has been made more configurable by providing a factory which
     is used to create the record.  The factory can be set using *note
     getLogRecordFactory(): 3173. and *note setLogRecordFactory(): 3174.
     (see this for the factory’s signature).

     This functionality can be used to inject your own values into a
     *note LogRecord: 11e8. at creation time.  You can use the following
     pattern:

          old_factory = logging.getLogRecordFactory()

          def record_factory(*args, **kwargs):
              record = old_factory(*args, **kwargs)
              record.custom_attribute = 0xdecafbad
              return record

          logging.setLogRecordFactory(record_factory)

     With this pattern, multiple factories could be chained, and as long
     as they don’t overwrite each other’s attributes or unintentionally
     overwrite the standard attributes listed above, there should be no
     surprises.


File: python.info,  Node: LogRecord attributes,  Next: LoggerAdapter Objects,  Prev: LogRecord Objects,  Up: logging — Logging facility for Python

5.16.4.7 LogRecord attributes
.............................

The LogRecord has a number of attributes, most of which are derived from
the parameters to the constructor.  (Note that the names do not always
correspond exactly between the LogRecord constructor parameters and the
LogRecord attributes.)  These attributes can be used to merge data from
the record into the format string.  The following table lists (in
alphabetical order) the attribute names, their meanings and the
corresponding placeholder in a %-style format string.

If you are using {}-formatting (*note str.format(): 834.), you can use
‘{attrname}’ as the placeholder in the format string.  If you are using
$-formatting (*note string.Template: 898.), use the form ‘${attrname}’.
In both cases, of course, replace ‘attrname’ with the actual attribute
name you want to use.

In the case of {}-formatting, you can specify formatting flags by
placing them after the attribute name, separated from it with a colon.
For example: a placeholder of ‘{msecs:03.0f}’ would format a millisecond
value of ‘4’ as ‘004’.  Refer to the *note str.format(): 834.
documentation for full details on the options available to you.

Attribute name       Format                        Description
                                                   
-------------------------------------------------------------------------------------------------------
                                                   
args                 You shouldn’t need to         The tuple of arguments merged into ‘msg’ to
                     format this yourself.         produce ‘message’, or a dict whose values are
                                                   used for the merge (when there is only one
                                                   argument, and it is a dictionary).
                                                   
                                                   
asctime              ‘%(asctime)s’                 Human-readable time when the
                                                   *note LogRecord: 11e8. was created.  By default
                                                   this is of the form “2003-07-08 16:49:45,896”
                                                   (the numbers after the comma are millisecond
                                                   portion of the time).
                                                   
                                                   
created              ‘%(created)f’                 Time when the *note LogRecord: 11e8. was created
                                                   (as returned by *note time.time_ns(): ce2. /
                                                   1e9).
                                                   
                                                   
exc_info             You shouldn’t need to         Exception tuple (à la ‘sys.exc_info’) or, if no
                     format this yourself.         exception has occurred, ‘None’.
                                                   
                                                   
exc_text             You shouldn’t need to         Exception information formatted as a string.
                     format this yourself.         This is set when *note Formatter.format(): 3162.
                                                   is invoked, or ‘None’ if no exception has
                                                   occurred.
                                                   
                                                   
filename             ‘%(filename)s’                Filename portion of ‘pathname’.
                                                   
                                                   
funcName             ‘%(funcName)s’                Name of function containing the logging call.
                                                   
                                                   
levelname            ‘%(levelname)s’               Text logging level for the message (‘'DEBUG'’,
                                                   ‘'INFO'’, ‘'WARNING'’, ‘'ERROR'’, ‘'CRITICAL'’).
                                                   
                                                   
levelno              ‘%(levelno)s’                 Numeric logging level for the message
                                                   (*note DEBUG: 20c7, *note INFO: 20c8,
                                                   *note WARNING: 20c9, *note ERROR: 20ca,
                                                   *note CRITICAL: 20cb.).
                                                   
                                                   
lineno               ‘%(lineno)d’                  Source line number where the logging call was
                                                   issued (if available).
                                                   
                                                   
message              ‘%(message)s’                 The logged message, computed as ‘msg % args’.
                                                   This is set when *note Formatter.format(): 3162.
                                                   is invoked.
                                                   
                                                   
module               ‘%(module)s’                  Module (name portion of ‘filename’).
                                                   
                                                   
msecs                ‘%(msecs)d’                   Millisecond portion of the time when the
                                                   *note LogRecord: 11e8. was created.
                                                   
                                                   
msg                  You shouldn’t need to         The format string passed in the original logging
                     format this yourself.         call.  Merged with ‘args’ to produce ‘message’,
                                                   or an arbitrary object (see
                                                   *note Using arbitrary objects as messages: 3171.).
                                                   
                                                   
name                 ‘%(name)s’                    Name of the logger used to log the call.
                                                   
                                                   
pathname             ‘%(pathname)s’                Full pathname of the source file where the
                                                   logging call was issued (if available).
                                                   
                                                   
process              ‘%(process)d’                 Process ID (if available).
                                                   
                                                   
processName          ‘%(processName)s’             Process name (if available).
                                                   
                                                   
relativeCreated      ‘%(relativeCreated)d’         Time in milliseconds when the LogRecord was
                                                   created, relative to the time the logging module
                                                   was loaded.
                                                   
                                                   
stack_info           You shouldn’t need to         Stack frame information (where available) from
                     format this yourself.         the bottom of the stack in the current thread, up
                                                   to and including the stack frame of the logging
                                                   call which resulted in the creation of this
                                                   record.
                                                   
                                                   
thread               ‘%(thread)d’                  Thread ID (if available).
                                                   
                                                   
threadName           ‘%(threadName)s’              Thread name (if available).
                                                   
                                                   
taskName             ‘%(taskName)s’                *note asyncio.Task: 1c7. name (if available).
                                                   

Cambiato nella versione 3.1: 'processName' was added.

Cambiato nella versione 3.12: 'taskName' was added.


File: python.info,  Node: LoggerAdapter Objects,  Next: Thread Safety,  Prev: LogRecord attributes,  Up: logging — Logging facility for Python

5.16.4.8 LoggerAdapter Objects
..............................

*note LoggerAdapter: 14fd. instances are used to conveniently pass
contextual information into logging calls.  For a usage example, see the
section on *note adding contextual information to your logging output:
3178.

 -- Classe: logging.LoggerAdapter (logger, extra=None,
          merge_extra=False)

     Returns an instance of *note LoggerAdapter: 14fd. initialized with
     an underlying *note Logger: d48. instance, an optional dict-like
     object ('extra'), and an optional boolean ('merge_extra')
     indicating whether or not the 'extra' argument of individual log
     calls should be merged with the *note LoggerAdapter: 14fd. extra.
     The default behavior is to ignore the 'extra' argument of
     individual log calls and only use the one of the *note
     LoggerAdapter: 14fd. instance

      -- Metodo: process (msg, kwargs)

          Modifies the message and/or keyword arguments passed to a
          logging call in order to insert contextual information.  This
          implementation takes the object passed as 'extra' to the
          constructor and adds it to 'kwargs' using key “extra”.  The
          return value is a ('msg', 'kwargs') tuple which has the
          (possibly modified) versions of the arguments passed in.

      -- Attributo: manager

          Delegates to the underlying ‘manager’ on 'logger'.

      -- Attributo: _log

          Delegates to the underlying ‘_log()’ method on 'logger'.

     In addition to the above, *note LoggerAdapter: 14fd. supports the
     following methods of *note Logger: d48.: *note debug(): 102d, *note
     info(): 3142, *note warning(): 1a5c, *note error(): 3144, *note
     exception(): 102b, *note critical(): 102c, *note log(): 102a, *note
     isEnabledFor(): 14fe, *note getEffectiveLevel(): 3140, *note
     setLevel(): 169a. and *note hasHandlers(): 314b.  These methods
     have the same signatures as their counterparts in *note Logger:
     d48, so you can use the two types of instances interchangeably.

     Cambiato nella versione 3.2: The *note isEnabledFor(): 14fe, *note
     getEffectiveLevel(): 3140, *note setLevel(): 169a. and *note
     hasHandlers(): 314b. methods were added to *note LoggerAdapter:
     14fd.  These methods delegate to the underlying logger.

     Cambiato nella versione 3.6: Attribute ‘manager’ and method
     ‘_log()’ were added, which delegate to the underlying logger and
     allow adapters to be nested.

     Cambiato nella versione 3.10: The 'extra' argument is now optional.

     Cambiato nella versione 3.13: The 'merge_extra' parameter was
     added.


File: python.info,  Node: Thread Safety,  Next: Module-Level Functions,  Prev: LoggerAdapter Objects,  Up: logging — Logging facility for Python

5.16.4.9 Thread Safety
......................

The logging module is intended to be thread-safe without any special
work needing to be done by its clients.  It achieves this through using
threading locks; there is one lock to serialize access to the module’s
shared data, and each handler also creates a lock to serialize access to
its underlying I/O.

If you are implementing asynchronous signal handlers using the *note
signal: cb. module, you may not be able to use logging from within such
handlers.  This is because lock implementations in the *note threading:
f3. module are not always re-entrant, and so cannot be invoked from such
signal handlers.


File: python.info,  Node: Module-Level Functions,  Next: Module-Level Attributes,  Prev: Thread Safety,  Up: logging — Logging facility for Python

5.16.4.10 Module-Level Functions
................................

In addition to the classes described above, there are a number of
module-level functions.

 -- Funzione: logging.getLogger (name=None)

     Return a logger with the specified name or, if name is ‘None’,
     return the root logger of the hierarchy.  If specified, the name is
     typically a dot-separated hierarchical name like '“a”', '“a.b”' or
     '“a.b.c.d”'.  Choice of these names is entirely up to the developer
     who is using logging, though it is recommended that ‘__name__’ be
     used unless you have a specific reason for not doing that, as
     mentioned in *note Logger Objects: 3136.

     All calls to this function with a given name return the same logger
     instance.  This means that logger instances never need to be passed
     between different parts of an application.

 -- Funzione: logging.getLoggerClass ()

     Return either the standard *note Logger: d48. class, or the last
     class passed to *note setLoggerClass(): 317f.  This function may be
     called from within a new class definition, to ensure that
     installing a customized *note Logger: d48. class will not undo
     customizations already applied by other code.  For example:

          class MyLogger(logging.getLoggerClass()):
              # ... override behaviour here

 -- Funzione: logging.getLogRecordFactory ()

     Return a callable which is used to create a *note LogRecord: 11e8.

     Added in version 3.2: This function has been provided, along with
     *note setLogRecordFactory(): 3174, to allow developers more control
     over how the *note LogRecord: 11e8. representing a logging event is
     constructed.

     See *note setLogRecordFactory(): 3174. for more information about
     the how the factory is called.

 -- Funzione: logging.debug (msg, *args, **kwargs)

     This is a convenience function that calls *note Logger.debug():
     102d, on the root logger.  The handling of the arguments is in
     every way identical to what is described in that method.

     The only difference is that if the root logger has no handlers,
     then *note basicConfig(): bf5. is called, prior to calling ‘debug’
     on the root logger.

     For very short scripts or quick demonstrations of ‘logging’
     facilities, ‘debug’ and the other module-level functions may be
     convenient.  However, most programs will want to carefully and
     explicitly control the logging configuration, and should therefore
     prefer creating a module-level logger and calling *note
     Logger.debug(): 102d. (or other level-specific methods) on it, as
     described at the beginning of this documentation.

 -- Funzione: logging.info (msg, *args, **kwargs)

     Logs a message with level *note INFO: 20c8. on the root logger.
     The arguments and behavior are otherwise the same as for *note
     debug(): 3143.

 -- Funzione: logging.warning (msg, *args, **kwargs)

     Logs a message with level *note WARNING: 20c9. on the root logger.
     The arguments and behavior are otherwise the same as for *note
     debug(): 3143.

          Nota: There is an obsolete function ‘warn’ which is
          functionally identical to ‘warning’.  As ‘warn’ is deprecated,
          please do not use it - use ‘warning’ instead.

 -- Funzione: logging.error (msg, *args, **kwargs)

     Logs a message with level *note ERROR: 20ca. on the root logger.
     The arguments and behavior are otherwise the same as for *note
     debug(): 3143.

 -- Funzione: logging.critical (msg, *args, **kwargs)

     Logs a message with level *note CRITICAL: 20cb. on the root logger.
     The arguments and behavior are otherwise the same as for *note
     debug(): 3143.

 -- Funzione: logging.exception (msg, *args, **kwargs)

     Logs a message with level *note ERROR: 20ca. on the root logger.
     The arguments and behavior are otherwise the same as for *note
     debug(): 3143.  Exception info is added to the logging message.
     This function should only be called from an exception handler.

 -- Funzione: logging.log (level, msg, *args, **kwargs)

     Logs a message with level 'level' on the root logger.  The
     arguments and behavior are otherwise the same as for *note debug():
     3143.

 -- Funzione: logging.disable (level=CRITICAL)

     Provides an overriding level 'level' for all loggers which takes
     precedence over the logger’s own level.  When the need arises to
     temporarily throttle logging output down across the whole
     application, this function can be useful.  Its effect is to disable
     all logging calls of severity 'level' and below, so that if you
     call it with a value of INFO, then all INFO and DEBUG events would
     be discarded, whereas those of severity WARNING and above would be
     processed according to the logger’s effective level.  If
     ‘logging.disable(logging.NOTSET)’ is called, it effectively removes
     this overriding level, so that logging output again depends on the
     effective levels of individual loggers.

     Note that if you have defined any custom logging level higher than
     ‘CRITICAL’ (this is not recommended), you won’t be able to rely on
     the default value for the 'level' parameter, but will have to
     explicitly supply a suitable value.

     Cambiato nella versione 3.7: The 'level' parameter was defaulted to
     level ‘CRITICAL’.  See bpo-28524(1) for more information about this
     change.

 -- Funzione: logging.addLevelName (level, levelName)

     Associates level 'level' with text 'levelName' in an internal
     dictionary, which is used to map numeric levels to a textual
     representation, for example when a *note Formatter: 169e. formats a
     message.  This function can also be used to define your own levels.
     The only constraints are that all levels used must be registered
     using this function, levels should be positive integers and they
     should increase in increasing order of severity.

          Nota: If you are thinking of defining your own levels, please
          see the section on *note Custom Levels: 3185.

 -- Funzione: logging.getLevelNamesMapping ()

     Returns a mapping from level names to their corresponding logging
     levels.  For example, the string «CRITICAL» maps to *note CRITICAL:
     20cb.  The returned mapping is copied from an internal mapping on
     each call to this function.

     Added in version 3.11.

 -- Funzione: logging.getLevelName (level)

     Returns the textual or numeric representation of logging level
     'level'.

     If 'level' is one of the predefined levels *note CRITICAL: 20cb,
     *note ERROR: 20ca, *note WARNING: 20c9, *note INFO: 20c8. or *note
     DEBUG: 20c7. then you get the corresponding string.  If you have
     associated levels with names using *note addLevelName(): 3184. then
     the name you have associated with 'level' is returned.  If a
     numeric value corresponding to one of the defined levels is passed
     in, the corresponding string representation is returned.

     The 'level' parameter also accepts a string representation of the
     level such as “INFO”.  In such cases, this functions returns the
     corresponding numeric value of the level.

     If no matching numeric or string value is passed in, the string
     “Level %s” % level is returned.

          Nota: Levels are internally integers (as they need to be
          compared in the logging logic).  This function is used to
          convert between an integer level and the level name displayed
          in the formatted log output by means of the ‘%(levelname)s’
          format specifier (see *note LogRecord attributes: 3141.), and
          vice versa.

     Cambiato nella versione 3.4: In Python versions earlier than 3.4,
     this function could also be passed a text level, and would return
     the corresponding numeric value of the level.  This undocumented
     behaviour was considered a mistake, and was removed in Python 3.4,
     but reinstated in 3.4.2 due to retain backward compatibility.

 -- Funzione: logging.getHandlerByName (name)

     Returns a handler with the specified 'name', or ‘None’ if there is
     no handler with that name.

     Added in version 3.12.

 -- Funzione: logging.getHandlerNames ()

     Returns an immutable set of all known handler names.

     Added in version 3.12.

 -- Funzione: logging.makeLogRecord (attrdict)

     Creates and returns a new *note LogRecord: 11e8. instance whose
     attributes are defined by 'attrdict'.  This function is useful for
     taking a pickled *note LogRecord: 11e8. attribute dictionary, sent
     over a socket, and reconstituting it as a *note LogRecord: 11e8.
     instance at the receiving end.

 -- Funzione: logging.basicConfig (**kwargs)

     Does basic configuration for the logging system by creating a *note
     StreamHandler: 1400. with a default *note Formatter: 169e. and
     adding it to the root logger.  The functions *note debug(): 3143,
     *note info(): 316c, *note warning(): 354, *note error(): 3180. and
     *note critical(): 3181. will call *note basicConfig(): bf5.
     automatically if no handlers are defined for the root logger.

     This function does nothing if the root logger already has handlers
     configured, unless the keyword argument 'force' is set to ‘True’.

          Nota: This function should be called from the main thread
          before other threads are started.  In versions of Python prior
          to 2.7.1 and 3.2, if this function is called from multiple
          threads, it is possible (in rare circumstances) that a handler
          will be added to the root logger more than once, leading to
          unexpected results such as messages being duplicated in the
          log.

     The following keyword arguments are supported.

     Format             Description
                        
     ---------------------------------------------------------------------
                        
     'filename'         Specifies that a *note FileHandler: 1c3b. be
                        created, using the specified filename, rather
                        than a *note StreamHandler: 1400.
                        
                        
     'filemode'         If 'filename' is specified, open the file in
                        this *note mode: 25b5.  Defaults to ‘'a'’.
                        
                        
     'format'           Use the specified format string for the
                        handler.  Defaults to attributes ‘levelname’,
                        ‘name’ and ‘message’ separated by colons.
                        
                        
     'datefmt'          Use the specified date/time format, as accepted
                        by *note time.strftime(): 13f1.
                        
                        
     'style'            If 'format' is specified, use this style for
                        the format string.  One of ‘'%'’, ‘'{'’ or
                        ‘'$'’ for *note printf-style: 8dc,
                        *note str.format(): 834. or
                        *note string.Template: 898. respectively.
                        Defaults to ‘'%'’.
                        
                        
     'level'            Set the root logger level to the specified
                        *note level: 86b.
                        
                        
     'stream'           Use the specified stream to initialize the
                        *note StreamHandler: 1400.  Note that this
                        argument is incompatible with 'filename' - if
                        both are present, a ‘ValueError’ is raised.
                        
                        
     'handlers'         If specified, this should be an iterable of
                        already created handlers to add to the root
                        logger.  Any handlers which don’t already have
                        a formatter set will be assigned the default
                        formatter created in this function.  Note that
                        this argument is incompatible with 'filename'
                        or 'stream' - if both are present, a
                        ‘ValueError’ is raised.
                        
                        
     'force'            If this keyword argument is specified as true,
                        any existing handlers attached to the root
                        logger are removed and closed, before carrying
                        out the configuration as specified by the other
                        arguments.
                        
                        
     'encoding'         If this keyword argument is specified along
                        with 'filename', its value is used when the
                        *note FileHandler: 1c3b. is created, and thus
                        used when opening the output file.
                        
                        
     'errors'           If this keyword argument is specified along
                        with 'filename', its value is used when the
                        *note FileHandler: 1c3b. is created, and thus
                        used when opening the output file.  If not
                        specified, the value “backslashreplace” is
                        used.  Note that if ‘None’ is specified, it
                        will be passed as such to *note open(): 316,
                        which means that it will be treated the same as
                        passing “errors”.
                        

     Cambiato nella versione 3.2: The 'style' argument was added.

     Cambiato nella versione 3.3: The 'handlers' argument was added.
     Additional checks were added to catch situations where incompatible
     arguments are specified (e.g.  'handlers' together with 'stream' or
     'filename', or 'stream' together with 'filename').

     Cambiato nella versione 3.8: The 'force' argument was added.

     Cambiato nella versione 3.9: The 'encoding' and 'errors' arguments
     were added.

 -- Funzione: logging.shutdown ()

     Informs the logging system to perform an orderly shutdown by
     flushing and closing all handlers.  This should be called at
     application exit and no further use of the logging system should be
     made after this call.

     When the logging module is imported, it registers this function as
     an exit handler (see *note atexit: d.), so normally there’s no need
     to do that manually.

 -- Funzione: logging.setLoggerClass (klass)

     Tells the logging system to use the class 'klass' when
     instantiating a logger.  The class should define ‘__init__()’ such
     that only a name argument is required, and the ‘__init__()’ should
     call ‘Logger.__init__()’.  This function is typically called before
     any loggers are instantiated by applications which need to use
     custom logger behavior.  After this call, as at any other time, do
     not instantiate loggers directly using the subclass: continue to
     use the *note logging.getLogger(): b5b. API to get your loggers.

 -- Funzione: logging.setLogRecordFactory (factory)

     Set a callable which is used to create a *note LogRecord: 11e8.


     Parametri: ‘factory’ – The factory callable to be used to
     instantiate a log record.

     Added in version 3.2: This function has been provided, along with
     *note getLogRecordFactory(): 3173, to allow developers more control
     over how the *note LogRecord: 11e8. representing a logging event is
     constructed.

     The factory has the following signature:

     ‘factory(name, level, fn, lno, msg, args, exc_info, func=None,
     sinfo=None, **kwargs)’


          name: The logger name.


          level: The logging level (numeric).


          fn: The full pathname of the file where the logging call was
          made.


          lno: The line number in the file where the logging call was
          made.


          msg: The logging message.


          args: The arguments for the logging message.


          exc_info: An exception tuple, or ‘None’.


          func: The name of the function or method which invoked the
          logging call.


          sinfo: A stack traceback such as is provided by *note
          traceback.print_stack(): 1088, showing the call hierarchy.


          kwargs: Additional keyword arguments.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=28524


File: python.info,  Node: Module-Level Attributes,  Next: Integration with the warnings module,  Prev: Module-Level Functions,  Up: logging — Logging facility for Python

5.16.4.11 Module-Level Attributes
.................................

 -- Dati: logging.lastResort

     A «handler of last resort» is available through this attribute.
     This is a *note StreamHandler: 1400. writing to ‘sys.stderr’ with a
     level of ‘WARNING’, and is used to handle logging events in the
     absence of any logging configuration.  The end result is to just
     print the message to ‘sys.stderr’.  This replaces the earlier error
     message saying that «no handlers could be found for logger XYZ».
     If you need the earlier behaviour for some reason, ‘lastResort’ can
     be set to ‘None’.

     Added in version 3.2.

 -- Dati: logging.raiseExceptions

     Used to see if exceptions during handling should be propagated.

     Default: ‘True’.

     If *note raiseExceptions: 1401. is ‘False’, exceptions get silently
     ignored.  This is what is mostly wanted for a logging system - most
     users will not care about errors in the logging system, they are
     more interested in application errors.


File: python.info,  Node: Integration with the warnings module,  Prev: Module-Level Attributes,  Up: logging — Logging facility for Python

5.16.4.12 Integration with the warnings module
..............................................

The *note captureWarnings(): 318a. function can be used to integrate
*note logging: 8b. with the *note warnings: 118. module.

 -- Funzione: logging.captureWarnings (capture)

     This function is used to turn the capture of warnings by logging on
     and off.

     If 'capture' is ‘True’, warnings issued by the *note warnings: 118.
     module will be redirected to the logging system.  Specifically, a
     warning will be formatted using *note warnings.formatwarning():
     1de0. and the resulting string logged to a logger named
     ‘'py.warnings'’ with a severity of *note WARNING: 20c9.

     If 'capture' is ‘False’, the redirection of warnings to the logging
     system will stop, and warnings will be redirected to their original
     destinations (i.e.  those in effect before ‘captureWarnings(True)’
     was called).

Vedi anche
..........

Module *note logging.config: 8c.

     Configuration API for the logging module.

Module *note logging.handlers: 8d.

     Useful handlers included with the logging module.

PEP 282(1) - A Logging System

     The proposal which described this feature for inclusion in the
     Python standard library.

Original Python logging package(2)

     This is the original source for the *note logging: 8b. package.
     The version of the package available from this site is suitable for
     use with Python 1.5.2, 2.1.x and 2.2.x, which do not include the
     *note logging: 8b. package in the standard library.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0282/

   (2) https://old.red-dove.com/python_logging.html


File: python.info,  Node: logging config — Logging configuration,  Next: logging handlers — Logging handlers,  Prev: logging — Logging facility for Python,  Up: Generic Operating System Services

5.16.5 ‘logging.config’ — Logging configuration
-----------------------------------------------

'Source code:' Lib/logging/config.py(1)

Important
.........

This page contains only reference information.  For tutorials, please
see

   * *note Basic Tutorial: 13fd.

   * *note Advanced Tutorial: 13fe.

   * *note Logging Cookbook: 13ff.

__________________________________________________________________

This section describes the API for configuring the logging module.

* Menu:

* Configuration functions::
* Security considerations::
* Configuration dictionary schema::
* Configuration file format::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/logging/config.py


File: python.info,  Node: Configuration functions,  Next: Security considerations,  Up: logging config — Logging configuration

5.16.5.1 Configuration functions
................................

The following functions configure the logging module.  They are located
in the *note logging.config: 8c. module.  Their use is optional — you
can configure the logging module using these functions or by making
calls to the main API (defined in *note logging: 8b. itself) and
defining handlers which are declared either in *note logging: 8b. or
*note logging.handlers: 8d.

 -- Funzione: logging.config.dictConfig (config)

     Takes the logging configuration from a dictionary.  The contents of
     this dictionary are described in *note Configuration dictionary
     schema: 318f. below.

     If an error is encountered during configuration, this function will
     raise a *note ValueError: 2ec, *note TypeError: 198, *note
     AttributeError: 5f0. or *note ImportError: 65b. with a suitably
     descriptive message.  The following is a (possibly incomplete) list
     of conditions which will raise an error:

        * A ‘level’ which is not a string or which is a string not
          corresponding to an actual logging level.

        * A ‘propagate’ value which is not a boolean.

        * An id which does not have a corresponding destination.

        * A non-existent handler id found during an incremental call.

        * An invalid logger name.

        * Inability to resolve to an internal or external object.

     Parsing is performed by the ‘DictConfigurator’ class, whose
     constructor is passed the dictionary used for configuration, and
     has a ‘configure()’ method.  The *note logging.config: 8c. module
     has a callable attribute ‘dictConfigClass’ which is initially set
     to ‘DictConfigurator’.  You can replace the value of
     ‘dictConfigClass’ with a suitable implementation of your own.

     *note dictConfig(): 13b8. calls ‘dictConfigClass’ passing the
     specified dictionary, and then calls the ‘configure()’ method on
     the returned object to put the configuration into effect:

          def dictConfig(config):
              dictConfigClass(config).configure()

     For example, a subclass of ‘DictConfigurator’ could call
     ‘DictConfigurator.__init__()’ in its own ‘__init__()’, then set up
     custom prefixes which would be usable in the subsequent
     ‘configure()’ call.  ‘dictConfigClass’ would be bound to this new
     subclass, and then *note dictConfig(): 13b8. could be called
     exactly as in the default, uncustomized state.

     Added in version 3.2.

 -- Funzione: logging.config.fileConfig (fname, defaults=None,
          disable_existing_loggers=True, encoding=None)

     Reads the logging configuration from a *note configparser:
     26.-format file.  The format of the file should be as described in
     *note Configuration file format: 3190.  This function can be called
     several times from an application, allowing an end user to select
     from various pre-canned configurations (if the developer provides a
     mechanism to present the choices and load the chosen
     configuration).

     It will raise *note FileNotFoundError: 264. if the file doesn’t
     exist and *note RuntimeError: 244. if the file is invalid or empty.


     Parametri:

        * ‘fname’ – A filename, or a file-like object, or an instance
          derived from *note RawConfigParser: 1166.  If a
          ‘RawConfigParser’-derived instance is passed, it is used as
          is.  Otherwise, a *note ConfigParser: 4df. is instantiated,
          and the configuration read by it from the object passed in
          ‘fname’.  If that has a *note readline(): bf. method, it is
          assumed to be a file-like object and read using *note
          read_file(): 72b.; otherwise, it is assumed to be a filename
          and passed to *note read(): 166f.

        * ‘defaults’ – Defaults to be passed to the ‘ConfigParser’ can
          be specified in this argument.

        * ‘disable_existing_loggers’ – If specified as ‘False’, loggers
          which exist when this call is made are left enabled.  The
          default is ‘True’ because this enables old behaviour in a
          backward-compatible way.  This behaviour is to disable any
          existing non-root loggers unless they or their ancestors are
          explicitly named in the logging configuration.

        * ‘encoding’ – The encoding used to open file when 'fname' is
          filename.

     Cambiato nella versione 3.4: An instance of a subclass of *note
     RawConfigParser: 1166. is now accepted as a value for ‘fname’.
     This facilitates:

             * Use of a configuration file where logging configuration
               is just part of the overall application configuration.

             * Use of a configuration read from a file, and then
               modified by the using application (e.g.  based on
               command-line parameters or other aspects of the runtime
               environment) before being passed to ‘fileConfig’.

     Cambiato nella versione 3.10: Added the 'encoding' parameter.

     Cambiato nella versione 3.12: An exception will be thrown if the
     provided file doesn’t exist or is invalid or empty.

 -- Funzione: logging.config.listen (port=DEFAULT_LOGGING_CONFIG_PORT,
          verify=None)

     Starts up a socket server on the specified port, and listens for
     new configurations.  If no port is specified, the module’s default
     ‘DEFAULT_LOGGING_CONFIG_PORT’ is used.  Logging configurations will
     be sent as a file suitable for processing by *note dictConfig():
     13b8. or *note fileConfig(): d4a.  Returns a *note Thread: 176.
     instance on which you can call *note start(): 178. to start the
     server, and which you can *note join(): 13ec. when appropriate.  To
     stop the server, call *note stopListening(): 3191.

     The ‘verify’ argument, if specified, should be a callable which
     should verify whether bytes received across the socket are valid
     and should be processed.  This could be done by encrypting and/or
     signing what is sent across the socket, such that the ‘verify’
     callable can perform signature verification and/or decryption.  The
     ‘verify’ callable is called with a single argument - the bytes
     received across the socket - and should return the bytes to be
     processed, or ‘None’ to indicate that the bytes should be
     discarded.  The returned bytes could be the same as the passed in
     bytes (e.g.  when only verification is done), or they could be
     completely different (perhaps if decryption were performed).

     To send a configuration to the socket, read in the configuration
     file and send it to the socket as a sequence of bytes preceded by a
     four-byte length string packed in binary using ‘struct.pack('>L',
     n)’.
          Nota: Because portions of the configuration are passed through
          *note eval(): 4a4, use of this function may open its users to
          a security risk.  While the function only binds to a socket on
          ‘localhost’, and so does not accept connections from remote
          machines, there are scenarios where untrusted code could be
          run under the account of the process which calls *note
          listen(): 1167.  Specifically, if the process calling *note
          listen(): 1167. runs on a multi-user machine where users
          cannot trust each other, then a malicious user could arrange
          to run essentially arbitrary code in a victim user’s process,
          simply by connecting to the victim’s *note listen(): 1167.
          socket and sending a configuration which runs whatever code
          the attacker wants to have executed in the victim’s process.
          This is especially easy to do if the default port is used, but
          not hard even if a different port is used.  To avoid the risk
          of this happening, use the ‘verify’ argument to *note
          listen(): 1167. to prevent unrecognised configurations from
          being applied.

     Cambiato nella versione 3.4: The ‘verify’ argument was added.

          Nota: If you want to send configurations to the listener which
          don’t disable existing loggers, you will need to use a JSON
          format for the configuration, which will use *note
          dictConfig(): 13b8. for configuration.  This method allows you
          to specify ‘disable_existing_loggers’ as ‘False’ in the
          configuration you send.

 -- Funzione: logging.config.stopListening ()

     Stops the listening server which was created with a call to *note
     listen(): 1167.  This is typically called before calling ‘join()’
     on the return value from *note listen(): 1167.


File: python.info,  Node: Security considerations,  Next: Configuration dictionary schema,  Prev: Configuration functions,  Up: logging config — Logging configuration

5.16.5.2 Security considerations
................................

The logging configuration functionality tries to offer convenience, and
in part this is done by offering the ability to convert text in
configuration files into Python objects used in logging configuration -
for example, as described in *note User-defined objects: 3194.  However,
these same mechanisms (importing callables from user-defined modules and
calling them with parameters from the configuration) could be used to
invoke any code you like, and for this reason you should treat
configuration files from untrusted sources with 'extreme caution' and
satisfy yourself that nothing bad can happen if you load them, before
actually loading them.


File: python.info,  Node: Configuration dictionary schema,  Next: Configuration file format,  Prev: Security considerations,  Up: logging config — Logging configuration

5.16.5.3 Configuration dictionary schema
........................................

Describing a logging configuration requires listing the various objects
to create and the connections between them; for example, you may create
a handler named “console” and then say that the logger named “startup”
will send its messages to the “console” handler.  These objects aren’t
limited to those provided by the *note logging: 8b. module because you
might write your own formatter or handler class.  The parameters to
these classes may also need to include external objects such as
‘sys.stderr’.  The syntax for describing these objects and connections
is defined in *note Object connections: 3196. below.

* Menu:

* Dictionary Schema Details::
* Incremental Configuration::
* Object connections::
* User-defined objects::
* Handler configuration order::
* Access to external objects::
* Access to internal objects::
* Import resolution and custom importers::
* Configuring QueueHandler and QueueListener::


File: python.info,  Node: Dictionary Schema Details,  Next: Incremental Configuration,  Up: Configuration dictionary schema

5.16.5.4 Dictionary Schema Details
..................................

The dictionary passed to *note dictConfig(): 13b8. must contain the
following keys:

   * 'version' - to be set to an integer value representing the schema
     version.  The only valid value at present is 1, but having this key
     allows the schema to evolve while still preserving backwards
     compatibility.

All other keys are optional, but if present they will be interpreted as
described below.  In all cases below where a “configuring dict” is
mentioned, it will be checked for the special ‘'()'’ key to see if a
custom instantiation is required.  If so, the mechanism described in
*note User-defined objects: 3194. below is used to create an instance;
otherwise, the context is used to determine what to instantiate.

   * 'formatters' - the corresponding value will be a dict in which each
     key is a formatter id and each value is a dict describing how to
     configure the corresponding *note Formatter: 169e. instance.

     The configuring dict is searched for the following optional keys
     which correspond to the arguments passed to create a *note
     Formatter: 169e. object:

        * ‘format’

        * ‘datefmt’

        * ‘style’

        * ‘validate’ (since version >=3.8)

        * ‘defaults’ (since version >=3.12)

     An optional ‘class’ key indicates the name of the formatter’s class
     (as a dotted module and class name).  The instantiation arguments
     are as for *note Formatter: 169e, thus this key is most useful for
     instantiating a customised subclass of *note Formatter: 169e.  For
     example, the alternative class might present exception tracebacks
     in an expanded or condensed format.  If your formatter requires
     different or extra configuration keys, you should use *note
     User-defined objects: 3194.

   * 'filters' - the corresponding value will be a dict in which each
     key is a filter id and each value is a dict describing how to
     configure the corresponding Filter instance.

     The configuring dict is searched for the key ‘name’ (defaulting to
     the empty string) and this is used to construct a *note
     logging.Filter: 1403. instance.

   * 'handlers' - the corresponding value will be a dict in which each
     key is a handler id and each value is a dict describing how to
     configure the corresponding Handler instance.

     The configuring dict is searched for the following keys:

        * ‘class’ (mandatory).  This is the fully qualified name of the
          handler class.

        * ‘level’ (optional).  The level of the handler.

        * ‘formatter’ (optional).  The id of the formatter for this
          handler.

        * ‘filters’ (optional).  A list of ids of the filters for this
          handler.

          Cambiato nella versione 3.11: ‘filters’ can take filter
          instances in addition to ids.

     All 'other' keys are passed through as keyword arguments to the
     handler’s constructor.  For example, given the snippet:

          handlers:
            console:
              class : logging.StreamHandler
              formatter: brief
              level   : INFO
              filters: [allow_foo]
              stream  : ext://sys.stdout
            file:
              class : logging.handlers.RotatingFileHandler
              formatter: precise
              filename: logconfig.log
              maxBytes: 1024
              backupCount: 3

     the handler with id ‘console’ is instantiated as a *note
     logging.StreamHandler: 1400, using ‘sys.stdout’ as the underlying
     stream.  The handler with id ‘file’ is instantiated as a *note
     logging.handlers.RotatingFileHandler: 1929. with the keyword
     arguments ‘filename='logconfig.log', maxBytes=1024, backupCount=3’.

   * 'loggers' - the corresponding value will be a dict in which each
     key is a logger name and each value is a dict describing how to
     configure the corresponding Logger instance.

     The configuring dict is searched for the following keys:

        * ‘level’ (optional).  The level of the logger.

        * ‘propagate’ (optional).  The propagation setting of the
          logger.

        * ‘filters’ (optional).  A list of ids of the filters for this
          logger.

          Cambiato nella versione 3.11: ‘filters’ can take filter
          instances in addition to ids.

        * ‘handlers’ (optional).  A list of ids of the handlers for this
          logger.

     The specified loggers will be configured according to the level,
     propagation, filters and handlers specified.

   * 'root' - this will be the configuration for the root logger.
     Processing of the configuration will be as for any logger, except
     that the ‘propagate’ setting will not be applicable.

   * 'incremental' - whether the configuration is to be interpreted as
     incremental to the existing configuration.  This value defaults to
     ‘False’, which means that the specified configuration replaces the
     existing configuration with the same semantics as used by the
     existing *note fileConfig(): d4a. API.

     If the specified value is ‘True’, the configuration is processed as
     described in the section on *note Incremental Configuration: 3199.

   * 'disable_existing_loggers' - whether any existing non-root loggers
     are to be disabled.  This setting mirrors the parameter of the same
     name in *note fileConfig(): d4a.  If absent, this parameter
     defaults to ‘True’.  This value is ignored if 'incremental' is
     ‘True’.


File: python.info,  Node: Incremental Configuration,  Next: Object connections,  Prev: Dictionary Schema Details,  Up: Configuration dictionary schema

5.16.5.5 Incremental Configuration
..................................

It is difficult to provide complete flexibility for incremental
configuration.  For example, because objects such as filters and
formatters are anonymous, once a configuration is set up, it is not
possible to refer to such anonymous objects when augmenting a
configuration.

Furthermore, there is not a compelling case for arbitrarily altering the
object graph of loggers, handlers, filters, formatters at run-time, once
a configuration is set up; the verbosity of loggers and handlers can be
controlled just by setting levels (and, in the case of loggers,
propagation flags).  Changing the object graph arbitrarily in a safe way
is problematic in a multi-threaded environment; while not impossible,
the benefits are not worth the complexity it adds to the implementation.

Thus, when the ‘incremental’ key of a configuration dict is present and
is ‘True’, the system will completely ignore any ‘formatters’ and
‘filters’ entries, and process only the ‘level’ settings in the
‘handlers’ entries, and the ‘level’ and ‘propagate’ settings in the
‘loggers’ and ‘root’ entries.

Using a value in the configuration dict lets configurations to be sent
over the wire as pickled dicts to a socket listener.  Thus, the logging
verbosity of a long-running application can be altered over time with no
need to stop and restart the application.


File: python.info,  Node: Object connections,  Next: User-defined objects,  Prev: Incremental Configuration,  Up: Configuration dictionary schema

5.16.5.6 Object connections
...........................

The schema describes a set of logging objects - loggers, handlers,
formatters, filters - which are connected to each other in an object
graph.  Thus, the schema needs to represent connections between the
objects.  For example, say that, once configured, a particular logger
has attached to it a particular handler.  For the purposes of this
discussion, we can say that the logger represents the source, and the
handler the destination, of a connection between the two.  Of course in
the configured objects this is represented by the logger holding a
reference to the handler.  In the configuration dict, this is done by
giving each destination object an id which identifies it unambiguously,
and then using the id in the source object’s configuration to indicate
that a connection exists between the source and the destination object
with that id.

So, for example, consider the following YAML snippet:

     formatters:
       brief:
         # configuration for formatter with id 'brief' goes here
       precise:
         # configuration for formatter with id 'precise' goes here
     handlers:
       h1: #This is an id
        # configuration of handler with id 'h1' goes here
        formatter: brief
       h2: #This is another id
        # configuration of handler with id 'h2' goes here
        formatter: precise
     loggers:
       foo.bar.baz:
         # other configuration for logger 'foo.bar.baz'
         handlers: [h1, h2]

(Note: YAML used here because it’s a little more readable than the
equivalent Python source form for the dictionary.)

The ids for loggers are the logger names which would be used
programmatically to obtain a reference to those loggers, e.g.
‘foo.bar.baz’.  The ids for Formatters and Filters can be any string
value (such as ‘brief’, ‘precise’ above) and they are transient, in that
they are only meaningful for processing the configuration dictionary and
used to determine connections between objects, and are not persisted
anywhere when the configuration call is complete.

The above snippet indicates that logger named ‘foo.bar.baz’ should have
two handlers attached to it, which are described by the handler ids ‘h1’
and ‘h2’.  The formatter for ‘h1’ is that described by id ‘brief’, and
the formatter for ‘h2’ is that described by id ‘precise’.


File: python.info,  Node: User-defined objects,  Next: Handler configuration order,  Prev: Object connections,  Up: Configuration dictionary schema

5.16.5.7 User-defined objects
.............................

The schema supports user-defined objects for handlers, filters and
formatters.  (Loggers do not need to have different types for different
instances, so there is no support in this configuration schema for
user-defined logger classes.)

Objects to be configured are described by dictionaries which detail
their configuration.  In some places, the logging system will be able to
infer from the context how an object is to be instantiated, but when a
user-defined object is to be instantiated, the system will not know how
to do this.  In order to provide complete flexibility for user-defined
object instantiation, the user needs to provide a “factory” - a callable
which is called with a configuration dictionary and which returns the
instantiated object.  This is signalled by an absolute import path to
the factory being made available under the special key ‘'()'’.  Here’s a
concrete example:

     formatters:
       brief:
         format: '%(message)s'
       default:
         format: '%(asctime)s %(levelname)-8s %(name)-15s %(message)s'
         datefmt: '%Y-%m-%d %H:%M:%S'
       custom:
           (): my.package.customFormatterFactory
           bar: baz
           spam: 99.9
           answer: 42

The above YAML snippet defines three formatters.  The first, with id
‘brief’, is a standard *note logging.Formatter: 169e. instance with the
specified format string.  The second, with id ‘default’, has a longer
format and also defines the time format explicitly, and will result in a
*note logging.Formatter: 169e. initialized with those two format
strings.  Shown in Python source form, the ‘brief’ and ‘default’
formatters have configuration sub-dictionaries:

     {
       'format' : '%(message)s'
     }

and:

     {
       'format' : '%(asctime)s %(levelname)-8s %(name)-15s %(message)s',
       'datefmt' : '%Y-%m-%d %H:%M:%S'
     }

respectively, and as these dictionaries do not contain the special key
‘'()'’, the instantiation is inferred from the context: as a result,
standard *note logging.Formatter: 169e. instances are created.  The
configuration sub-dictionary for the third formatter, with id ‘custom’,
is:

     {
       '()' : 'my.package.customFormatterFactory',
       'bar' : 'baz',
       'spam' : 99.9,
       'answer' : 42
     }

and this contains the special key ‘'()'’, which means that user-defined
instantiation is wanted.  In this case, the specified factory callable
will be used.  If it is an actual callable it will be used directly -
otherwise, if you specify a string (as in the example) the actual
callable will be located using normal import mechanisms.  The callable
will be called with the 'remaining' items in the configuration
sub-dictionary as keyword arguments.  In the above example, the
formatter with id ‘custom’ will be assumed to be returned by the call:

     my.package.customFormatterFactory(bar='baz', spam=99.9, answer=42)

     Avvertimento: The values for keys such as ‘bar’, ‘spam’ and
     ‘answer’ in the above example should not be configuration
     dictionaries or references such as ‘cfg://foo’ or ‘ext://bar’,
     because they will not be processed by the configuration machinery,
     but passed to the callable as-is.

The key ‘'()'’ has been used as the special key because it is not a
valid keyword parameter name, and so will not clash with the names of
the keyword arguments used in the call.  The ‘'()'’ also serves as a
mnemonic that the corresponding value is a callable.

Cambiato nella versione 3.11: The ‘filters’ member of ‘handlers’ and
‘loggers’ can take filter instances in addition to ids.

You can also specify a special key ‘'.'’ whose value is a mapping of
attribute names to values.  If found, the specified attributes will be
set on the user-defined object before it is returned.  Thus, with the
following configuration:

     {
       '()' : 'my.package.customFormatterFactory',
       'bar' : 'baz',
       'spam' : 99.9,
       'answer' : 42,
       '.' {
         'foo': 'bar',
         'baz': 'bozz'
       }
     }

the returned formatter will have attribute ‘foo’ set to ‘'bar'’ and
attribute ‘baz’ set to ‘'bozz'’.

     Avvertimento: The values for attributes such as ‘foo’ and ‘baz’ in
     the above example should not be configuration dictionaries or
     references such as ‘cfg://foo’ or ‘ext://bar’, because they will
     not be processed by the configuration machinery, but set as
     attribute values as-is.


File: python.info,  Node: Handler configuration order,  Next: Access to external objects,  Prev: User-defined objects,  Up: Configuration dictionary schema

5.16.5.8 Handler configuration order
....................................

Handlers are configured in alphabetical order of their keys, and a
configured handler replaces the configuration dictionary in (a working
copy of) the ‘handlers’ dictionary in the schema.  If you use a
construct such as ‘cfg://handlers.foo’, then initially ‘handlers['foo']’
points to the configuration dictionary for the handler named ‘foo’, and
later (once that handler has been configured) it points to the
configured handler instance.  Thus, ‘cfg://handlers.foo’ could resolve
to either a dictionary or a handler instance.  In general, it is wise to
name handlers in a way such that dependent handlers are configured
'after' any handlers they depend on; that allows something like
‘cfg://handlers.foo’ to be used in configuring a handler that depends on
handler ‘foo’.  If that dependent handler were named ‘bar’, problems
would result, because the configuration of ‘bar’ would be attempted
before that of ‘foo’, and ‘foo’ would not yet have been configured.
However, if the dependent handler were named ‘foobar’, it would be
configured after ‘foo’, with the result that ‘cfg://handlers.foo’ would
resolve to configured handler ‘foo’, and not its configuration
dictionary.


File: python.info,  Node: Access to external objects,  Next: Access to internal objects,  Prev: Handler configuration order,  Up: Configuration dictionary schema

5.16.5.9 Access to external objects
...................................

There are times where a configuration needs to refer to objects external
to the configuration, for example ‘sys.stderr’.  If the configuration
dict is constructed using Python code, this is straightforward, but a
problem arises when the configuration is provided via a text file (e.g.
JSON, YAML). In a text file, there is no standard way to distinguish
‘sys.stderr’ from the literal string ‘'sys.stderr'’.  To facilitate this
distinction, the configuration system looks for certain special prefixes
in string values and treat them specially.  For example, if the literal
string ‘'ext://sys.stderr'’ is provided as a value in the configuration,
then the ‘ext://’ will be stripped off and the remainder of the value
processed using normal import mechanisms.

The handling of such prefixes is done in a way analogous to protocol
handling: there is a generic mechanism to look for prefixes which match
the regular expression ‘^(?P<prefix>[a-z]+)://(?P<suffix>.*)$’ whereby,
if the ‘prefix’ is recognised, the ‘suffix’ is processed in a
prefix-dependent manner and the result of the processing replaces the
string value.  If the prefix is not recognised, then the string value
will be left as-is.


File: python.info,  Node: Access to internal objects,  Next: Import resolution and custom importers,  Prev: Access to external objects,  Up: Configuration dictionary schema

5.16.5.10 Access to internal objects
....................................

As well as external objects, there is sometimes also a need to refer to
objects in the configuration.  This will be done implicitly by the
configuration system for things that it knows about.  For example, the
string value ‘'DEBUG'’ for a ‘level’ in a logger or handler will
automatically be converted to the value ‘logging.DEBUG’, and the
‘handlers’, ‘filters’ and ‘formatter’ entries will take an object id and
resolve to the appropriate destination object.

However, a more generic mechanism is needed for user-defined objects
which are not known to the *note logging: 8b. module.  For example,
consider *note logging.handlers.MemoryHandler: 31a3, which takes a
‘target’ argument which is another handler to delegate to.  Since the
system already knows about this class, then in the configuration, the
given ‘target’ just needs to be the object id of the relevant target
handler, and the system will resolve to the handler from the id.  If,
however, a user defines a ‘my.package.MyHandler’ which has an
‘alternate’ handler, the configuration system would not know that the
‘alternate’ referred to a handler.  To cater for this, a generic
resolution system allows the user to specify:

     handlers:
       file:
         # configuration of file handler goes here

       custom:
         (): my.package.MyHandler
         alternate: cfg://handlers.file

The literal string ‘'cfg://handlers.file'’ will be resolved in an
analogous way to strings with the ‘ext://’ prefix, but looking in the
configuration itself rather than the import namespace.  The mechanism
allows access by dot or by index, in a similar way to that provided by
‘str.format’.  Thus, given the following snippet:

     handlers:
       email:
         class: logging.handlers.SMTPHandler
         mailhost: localhost
         fromaddr: my_app@domain.tld
         toaddrs:
           - support_team@domain.tld
           - dev_team@domain.tld
         subject: Houston, we have a problem.

in the configuration, the string ‘'cfg://handlers'’ would resolve to the
dict with key ‘handlers’, the string ‘'cfg://handlers.email’ would
resolve to the dict with key ‘email’ in the ‘handlers’ dict, and so on.
The string ‘'cfg://handlers.email.toaddrs[1]’ would resolve to
‘'dev_team@domain.tld'’ and the string
‘'cfg://handlers.email.toaddrs[0]'’ would resolve to the value
‘'support_team@domain.tld'’.  The ‘subject’ value could be accessed
using either ‘'cfg://handlers.email.subject'’ or, equivalently,
‘'cfg://handlers.email[subject]'’.  The latter form only needs to be
used if the key contains spaces or non-alphanumeric characters.  Please
note that the characters ‘[’ and ‘]’ are not allowed in the keys.  If an
index value consists only of decimal digits, access will be attempted
using the corresponding integer value, falling back to the string value
if needed.

Given a string ‘cfg://handlers.myhandler.mykey.123’, this will resolve
to ‘config_dict['handlers']['myhandler']['mykey']['123']’.  If the
string is specified as ‘cfg://handlers.myhandler.mykey[123]’, the system
will attempt to retrieve the value from
‘config_dict['handlers']['myhandler']['mykey'][123]’, and fall back to
‘config_dict['handlers']['myhandler']['mykey']['123']’ if that fails.


File: python.info,  Node: Import resolution and custom importers,  Next: Configuring QueueHandler and QueueListener,  Prev: Access to internal objects,  Up: Configuration dictionary schema

5.16.5.11 Import resolution and custom importers
................................................

Import resolution, by default, uses the builtin *note __import__(): ad3.
function to do its importing.  You may want to replace this with your
own importing mechanism: if so, you can replace the ‘importer’ attribute
of the ‘DictConfigurator’ or its superclass, the ‘BaseConfigurator’
class.  However, you need to be careful because of the way functions are
accessed from classes via descriptors.  If you are using a Python
callable to do your imports, and you want to define it at class level
rather than instance level, you need to wrap it with *note
staticmethod(): 453.  For example:

     from importlib import import_module
     from logging.config import BaseConfigurator

     BaseConfigurator.importer = staticmethod(import_module)

You don’t need to wrap with *note staticmethod(): 453. if you’re setting
the import callable on a configurator 'instance'.


File: python.info,  Node: Configuring QueueHandler and QueueListener,  Prev: Import resolution and custom importers,  Up: Configuration dictionary schema

5.16.5.12 Configuring QueueHandler and QueueListener
....................................................

If you want to configure a *note QueueHandler: 1b49, noting that this is
normally used in conjunction with a *note QueueListener: 242, you can
configure both together.  After the configuration, the ‘QueueListener’
instance will be available as the *note listener: 31a7. attribute of the
created handler, and that in turn will be available to you using *note
getHandlerByName(): 1b4a. and passing the name you have used for the
‘QueueHandler’ in your configuration.  The dictionary schema for
configuring the pair is shown in the example YAML snippet below.

     handlers:
       qhand:
         class: logging.handlers.QueueHandler
         queue: my.module.queue_factory
         listener: my.package.CustomListener
         handlers:
           - hand_name_1
           - hand_name_2
           ...

The ‘queue’ and ‘listener’ keys are optional.

If the ‘queue’ key is present, the corresponding value can be one of the
following:

   * An object implementing the *note Queue.put_nowait: 31a8. and *note
     Queue.get: 31a9. public API. For instance, this may be an actual
     instance of *note queue.Queue: 159c. or a subclass thereof, or a
     proxy obtained by *note
     multiprocessing.managers.SyncManager.Queue(): 31aa.

     This is of course only possible if you are constructing or
     modifying the configuration dictionary in code.

   * A string that resolves to a callable which, when called with no
     arguments, returns the queue instance to use.  That callable could
     be a *note queue.Queue: 159c. subclass or a function which returns
     a suitable queue instance, such as ‘my.module.queue_factory()’.

   * A dict with a ‘'()'’ key which is constructed in the usual way as
     discussed in *note User-defined objects: 3194.  The result of this
     construction should be a *note queue.Queue: 159c. instance.

If the ‘queue’ key is absent, a standard unbounded *note queue.Queue:
159c. instance is created and used.

If the ‘listener’ key is present, the corresponding value can be one of
the following:

   * A subclass of *note logging.handlers.QueueListener: 242.  This is
     of course only possible if you are constructing or modifying the
     configuration dictionary in code.

   * A string which resolves to a class which is a subclass of
     ‘QueueListener’, such as ‘'my.package.CustomListener'’.

   * A dict with a ‘'()'’ key which is constructed in the usual way as
     discussed in *note User-defined objects: 3194.  The result of this
     construction should be a callable with the same signature as the
     ‘QueueListener’ initializer.

If the ‘listener’ key is absent, *note logging.handlers.QueueListener:
242. is used.

The values under the ‘handlers’ key are the names of other handlers in
the configuration (not shown in the above snippet) which will be passed
to the queue listener.

Any custom queue handler and listener classes will need to be defined
with the same initialization signatures as *note QueueHandler: 1b49. and
*note QueueListener: 242.

Added in version 3.12.


File: python.info,  Node: Configuration file format,  Prev: Configuration dictionary schema,  Up: logging config — Logging configuration

5.16.5.13 Configuration file format
...................................

The configuration file format understood by *note fileConfig(): d4a. is
based on *note configparser: 26. functionality.  The file must contain
sections called ‘[loggers]’, ‘[handlers]’ and ‘[formatters]’ which
identify by name the entities of each type which are defined in the
file.  For each such entity, there is a separate section which
identifies how that entity is configured.  Thus, for a logger named
‘log01’ in the ‘[loggers]’ section, the relevant configuration details
are held in a section ‘[logger_log01]’.  Similarly, a handler called
‘hand01’ in the ‘[handlers]’ section will have its configuration held in
a section called ‘[handler_hand01]’, while a formatter called ‘form01’
in the ‘[formatters]’ section will have its configuration specified in a
section called ‘[formatter_form01]’.  The root logger configuration must
be specified in a section called ‘[logger_root]’.

     Nota: The *note fileConfig(): d4a. API is older than the *note
     dictConfig(): 13b8. API and does not provide functionality to cover
     certain aspects of logging.  For example, you cannot configure
     *note Filter: 1403. objects, which provide for filtering of
     messages beyond simple integer levels, using *note fileConfig():
     d4a.  If you need to have instances of *note Filter: 1403. in your
     logging configuration, you will need to use *note dictConfig():
     13b8.  Note that future enhancements to configuration functionality
     will be added to *note dictConfig(): 13b8, so it’s worth
     considering transitioning to this newer API when it’s convenient to
     do so.

Examples of these sections in the file are given below.

     [loggers]
     keys=root,log02,log03,log04,log05,log06,log07

     [handlers]
     keys=hand01,hand02,hand03,hand04,hand05,hand06,hand07,hand08,hand09

     [formatters]
     keys=form01,form02,form03,form04,form05,form06,form07,form08,form09

The root logger must specify a level and a list of handlers.  An example
of a root logger section is given below.

     [logger_root]
     level=NOTSET
     handlers=hand01

The ‘level’ entry can be one of ‘DEBUG, INFO, WARNING, ERROR, CRITICAL’
or ‘NOTSET’.  For the root logger only, ‘NOTSET’ means that all messages
will be logged.  Level values are *note evaluated: 25a9. in the context
of the ‘logging’ package’s namespace.

The ‘handlers’ entry is a comma-separated list of handler names, which
must appear in the ‘[handlers]’ section.  These names must appear in the
‘[handlers]’ section and have corresponding sections in the
configuration file.

For loggers other than the root logger, some additional information is
required.  This is illustrated by the following example.

     [logger_parser]
     level=DEBUG
     handlers=hand01
     propagate=1
     qualname=compiler.parser

The ‘level’ and ‘handlers’ entries are interpreted as for the root
logger, except that if a non-root logger’s level is specified as
‘NOTSET’, the system consults loggers higher up the hierarchy to
determine the effective level of the logger.  The ‘propagate’ entry is
set to 1 to indicate that messages must propagate to handlers higher up
the logger hierarchy from this logger, or 0 to indicate that messages
are 'not' propagated to handlers up the hierarchy.  The ‘qualname’ entry
is the hierarchical channel name of the logger, that is to say the name
used by the application to get the logger.

Sections which specify handler configuration are exemplified by the
following.

     [handler_hand01]
     class=StreamHandler
     level=NOTSET
     formatter=form01
     args=(sys.stdout,)

The ‘class’ entry indicates the handler’s class (as determined by *note
eval(): 4a4. in the ‘logging’ package’s namespace).  The ‘level’ is
interpreted as for loggers, and ‘NOTSET’ is taken to mean “log
everything”.

The ‘formatter’ entry indicates the key name of the formatter for this
handler.  If blank, a default formatter (‘logging._defaultFormatter’) is
used.  If a name is specified, it must appear in the ‘[formatters]’
section and have a corresponding section in the configuration file.

The ‘args’ entry, when *note evaluated: 25a9. in the context of the
‘logging’ package’s namespace, is the list of arguments to the
constructor for the handler class.  Refer to the constructors for the
relevant handlers, or to the examples below, to see how typical entries
are constructed.  If not provided, it defaults to ‘()’.

The optional ‘kwargs’ entry, when *note evaluated: 25a9. in the context
of the ‘logging’ package’s namespace, is the keyword argument dict to
the constructor for the handler class.  If not provided, it defaults to
‘{}’.

     [handler_hand02]
     class=FileHandler
     level=DEBUG
     formatter=form02
     args=('python.log', 'w')

     [handler_hand03]
     class=handlers.SocketHandler
     level=INFO
     formatter=form03
     args=('localhost', handlers.DEFAULT_TCP_LOGGING_PORT)

     [handler_hand04]
     class=handlers.DatagramHandler
     level=WARN
     formatter=form04
     args=('localhost', handlers.DEFAULT_UDP_LOGGING_PORT)

     [handler_hand05]
     class=handlers.SysLogHandler
     level=ERROR
     formatter=form05
     args=(('localhost', handlers.SYSLOG_UDP_PORT), handlers.SysLogHandler.LOG_USER)

     [handler_hand06]
     class=handlers.NTEventLogHandler
     level=CRITICAL
     formatter=form06
     args=('Python Application', '', 'Application')

     [handler_hand07]
     class=handlers.SMTPHandler
     level=WARN
     formatter=form07
     args=('localhost', 'from@abc', ['user1@abc', 'user2@xyz'], 'Logger Subject')
     kwargs={'timeout': 10.0}

     [handler_hand08]
     class=handlers.MemoryHandler
     level=NOTSET
     formatter=form08
     target=
     args=(10, ERROR)

     [handler_hand09]
     class=handlers.HTTPHandler
     level=NOTSET
     formatter=form09
     args=('localhost:9022', '/log', 'GET')
     kwargs={'secure': True}

Sections which specify formatter configuration are typified by the
following.

     [formatter_form01]
     format=F1 %(asctime)s %(levelname)s %(message)s %(customfield)s
     datefmt=
     style=%
     validate=True
     defaults={'customfield': 'defaultvalue'}
     class=logging.Formatter

The arguments for the formatter configuration are the same as the keys
in the dictionary schema *note formatters section: 3198.

The ‘defaults’ entry, when *note evaluated: 25a9. in the context of the
‘logging’ package’s namespace, is a dictionary of default values for
custom formatting fields.  If not provided, it defaults to ‘None’.

     Nota: Due to the use of *note eval(): 4a4. as described above,
     there are potential security risks which result from using the
     *note listen(): 1167. to send and receive configurations via
     sockets.  The risks are limited to where multiple users with no
     mutual trust run code on the same machine; see the *note listen():
     1167. documentation for more information.

Vedi anche
..........

Module *note logging: 8b.

     API reference for the logging module.

Module *note logging.handlers: 8d.

     Useful handlers included with the logging module.


File: python.info,  Node: logging handlers — Logging handlers,  Next: platform — Access to underlying platform’s identifying data,  Prev: logging config — Logging configuration,  Up: Generic Operating System Services

5.16.6 ‘logging.handlers’ — Logging handlers
--------------------------------------------

'Source code:' Lib/logging/handlers.py(1)

Important
.........

This page contains only reference information.  For tutorials, please
see

   * *note Basic Tutorial: 13fd.

   * *note Advanced Tutorial: 13fe.

   * *note Logging Cookbook: 13ff.

__________________________________________________________________

The following useful handlers are provided in the package.  Note that
three of the handlers (*note StreamHandler: 1400, *note FileHandler:
1c3b. and *note NullHandler: 148c.) are actually defined in the *note
logging: 8b. module itself, but have been documented here along with the
other handlers.

* Menu:

* StreamHandler::
* FileHandler::
* NullHandler::
* WatchedFileHandler::
* BaseRotatingHandler::
* RotatingFileHandler::
* TimedRotatingFileHandler::
* SocketHandler::
* DatagramHandler::
* SysLogHandler::
* NTEventLogHandler::
* SMTPHandler::
* MemoryHandler::
* HTTPHandler::
* QueueHandler::
* QueueListener::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/logging/handlers.py


File: python.info,  Node: StreamHandler,  Next: FileHandler,  Up: logging handlers — Logging handlers

5.16.6.1 StreamHandler
......................

The *note StreamHandler: 1400. class, located in the core *note logging:
8b. package, sends logging output to streams such as 'sys.stdout',
'sys.stderr' or any file-like object (or, more precisely, any object
which supports ‘write()’ and ‘flush()’ methods).

 -- Classe: logging.StreamHandler (stream=None)

     Returns a new instance of the *note StreamHandler: 1400. class.  If
     'stream' is specified, the instance will use it for logging output;
     otherwise, 'sys.stderr' will be used.

      -- Metodo: emit (record)

          If a formatter is specified, it is used to format the record.
          The record is then written to the stream followed by *note
          terminator: 31b2.  If exception information is present, it is
          formatted using *note traceback.print_exception(): a51. and
          appended to the stream.

      -- Metodo: flush ()

          Flushes the stream by calling its *note flush(): 31b3. method.
          Note that the ‘close()’ method is inherited from *note
          Handler: 169d. and so does no output, so an explicit *note
          flush(): 31b3. call may be needed at times.

      -- Metodo: setStream (stream)

          Sets the instance’s stream to the specified value, if it is
          different.  The old stream is flushed before the new stream is
          set.


          Parametri: ‘stream’ – The stream that the handler should use.


          Ritorna: the old stream, if the stream was changed, or ‘None’
          if it wasn’t.

          Added in version 3.7.

      -- Attributo: terminator

          String used as the terminator when writing a formatted record
          to a stream.  Default value is ‘'\n'’.

          If you don’t want a newline termination, you can set the
          handler instance’s ‘terminator’ attribute to the empty string.

          In earlier versions, the terminator was hardcoded as ‘'\n'’.

          Added in version 3.2.


File: python.info,  Node: FileHandler,  Next: NullHandler,  Prev: StreamHandler,  Up: logging handlers — Logging handlers

5.16.6.2 FileHandler
....................

The *note FileHandler: 1c3b. class, located in the core *note logging:
8b. package, sends logging output to a disk file.  It inherits the
output functionality from *note StreamHandler: 1400.

 -- Classe: logging.FileHandler (filename, mode='a', encoding=None,
          delay=False, errors=None)

     Returns a new instance of the *note FileHandler: 1c3b. class.  The
     specified file is opened and used as the stream for logging.  If
     'mode' is not specified, ‘'a'’ is used.  If 'encoding' is not
     ‘None’, it is used to open the file with that encoding.  If 'delay'
     is true, then file opening is deferred until the first call to
     *note emit(): 31b6.  By default, the file grows indefinitely.  If
     'errors' is specified, it’s used to determine how encoding errors
     are handled.

     Cambiato nella versione 3.6: As well as string values, *note Path:
     266. objects are also accepted for the 'filename' argument.

     Cambiato nella versione 3.9: The 'errors' parameter was added.

      -- Metodo: close ()

          Closes the file.

      -- Metodo: emit (record)

          Outputs the record to the file.

          Note that if the file was closed due to logging shutdown at
          exit and the file mode is “w”, the record will not be emitted
          (see bpo-42378(1)).

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=42378


File: python.info,  Node: NullHandler,  Next: WatchedFileHandler,  Prev: FileHandler,  Up: logging handlers — Logging handlers

5.16.6.3 NullHandler
....................

Added in version 3.1.

The *note NullHandler: 148c. class, located in the core *note logging:
8b. package, does not do any formatting or output.  It is essentially a
“no-op” handler for use by library developers.

 -- Classe: logging.NullHandler

     Returns a new instance of the *note NullHandler: 148c. class.

      -- Metodo: emit (record)

          This method does nothing.

      -- Metodo: handle (record)

          This method does nothing.

      -- Metodo: createLock ()

          This method returns ‘None’ for the lock, since there is no
          underlying I/O to which access needs to be serialized.

See *note Configuring Logging for a Library: 31bd. for more information
on how to use *note NullHandler: 148c.


File: python.info,  Node: WatchedFileHandler,  Next: BaseRotatingHandler,  Prev: NullHandler,  Up: logging handlers — Logging handlers

5.16.6.4 WatchedFileHandler
...........................

The *note WatchedFileHandler: 31c0. class, located in the *note
logging.handlers: 8d. module, is a ‘FileHandler’ which watches the file
it is logging to.  If the file changes, it is closed and reopened using
the file name.

A file change can happen because of usage of programs such as
'newsyslog' and 'logrotate' which perform log file rotation.  This
handler, intended for use under Unix/Linux, watches the file to see if
it has changed since the last emit.  (A file is deemed to have changed
if its device or inode have changed.)  If the file has changed, the old
file stream is closed, and the file opened to get a new stream.

This handler is not appropriate for use under Windows, because under
Windows open log files cannot be moved or renamed - logging opens the
files with exclusive locks - and so there is no need for such a handler.
Furthermore, 'ST_INO' is not supported under Windows; *note stat(): 26d.
always returns zero for this value.

 -- Classe: logging.handlers.WatchedFileHandler (filename, mode='a',
          encoding=None, delay=False, errors=None)

     Returns a new instance of the *note WatchedFileHandler: 31c0.
     class.  The specified file is opened and used as the stream for
     logging.  If 'mode' is not specified, ‘'a'’ is used.  If 'encoding'
     is not ‘None’, it is used to open the file with that encoding.  If
     'delay' is true, then file opening is deferred until the first call
     to *note emit(): 31c1.  By default, the file grows indefinitely.
     If 'errors' is provided, it determines how encoding errors are
     handled.

     Cambiato nella versione 3.6: As well as string values, *note Path:
     266. objects are also accepted for the 'filename' argument.

     Cambiato nella versione 3.9: The 'errors' parameter was added.

      -- Metodo: reopenIfNeeded ()

          Checks to see if the file has changed.  If it has, the
          existing stream is flushed and closed and the file opened
          again, typically as a precursor to outputting the record to
          the file.

          Added in version 3.6.

      -- Metodo: emit (record)

          Outputs the record to the file, but first calls *note
          reopenIfNeeded(): eb6. to reopen the file if it has changed.


File: python.info,  Node: BaseRotatingHandler,  Next: RotatingFileHandler,  Prev: WatchedFileHandler,  Up: logging handlers — Logging handlers

5.16.6.5 BaseRotatingHandler
............................

The *note BaseRotatingHandler: 31c4. class, located in the *note
logging.handlers: 8d. module, is the base class for the rotating file
handlers, *note RotatingFileHandler: 1929. and *note
TimedRotatingFileHandler: 1163.  You should not need to instantiate this
class, but it has attributes and methods you may need to override.

 -- Classe: logging.handlers.BaseRotatingHandler (filename, mode,
          encoding=None, delay=False, errors=None)

     The parameters are as for ‘FileHandler’.  The attributes are:

      -- Attributo: namer

          If this attribute is set to a callable, the *note
          rotation_filename(): 31c6. method delegates to this callable.
          The parameters passed to the callable are those passed to
          *note rotation_filename(): 31c6.

               Nota: The namer function is called quite a few times
               during rollover, so it should be as simple and as fast as
               possible.  It should also return the same output every
               time for a given input, otherwise the rollover behaviour
               may not work as expected.

               It’s also worth noting that care should be taken when
               using a namer to preserve certain attributes in the
               filename which are used during rotation.  For example,
               *note RotatingFileHandler: 1929. expects to have a set of
               log files whose names contain successive integers, so
               that rotation works as expected, and *note
               TimedRotatingFileHandler: 1163. deletes old log files
               (based on the ‘backupCount’ parameter passed to the
               handler’s initializer) by determining the oldest files to
               delete.  For this to happen, the filenames should be
               sortable using the date/time portion of the filename, and
               a namer needs to respect this.  (If a namer is wanted
               that doesn’t respect this scheme, it will need to be used
               in a subclass of *note TimedRotatingFileHandler: 1163.
               which overrides the *note getFilesToDelete(): 31c7.
               method to fit in with the custom naming scheme.)

          Added in version 3.3.

      -- Attributo: rotator

          If this attribute is set to a callable, the *note rotate():
          31c9. method delegates to this callable.  The parameters
          passed to the callable are those passed to *note rotate():
          31c9.

          Added in version 3.3.

      -- Metodo: rotation_filename (default_name)

          Modify the filename of a log file when rotating.

          This is provided so that a custom filename can be provided.

          The default implementation calls the “namer” attribute of the
          handler, if it’s callable, passing the default name to it.  If
          the attribute isn’t callable (the default is ‘None’), the name
          is returned unchanged.


          Parametri: ‘default_name’ – The default name for the log file.

          Added in version 3.3.

      -- Metodo: rotate (source, dest)

          When rotating, rotate the current log.

          The default implementation calls the “rotator” attribute of
          the handler, if it’s callable, passing the source and dest
          arguments to it.  If the attribute isn’t callable (the default
          is ‘None’), the source is simply renamed to the destination.


          Parametri:

             * ‘source’ – The source filename.  This is normally the
               base filename, e.g.  “test.log”.

             * ‘dest’ – The destination filename.  This is normally what
               the source is rotated to, e.g.  “test.log.1”.

          Added in version 3.3.

The reason the attributes exist is to save you having to subclass - you
can use the same callables for instances of *note RotatingFileHandler:
1929. and *note TimedRotatingFileHandler: 1163.  If either the namer or
rotator callable raises an exception, this will be handled in the same
way as any other exception during an ‘emit()’ call, i.e.  via the
‘handleError()’ method of the handler.

If you need to make more significant changes to rotation processing, you
can override the methods.

For an example, see *note Using a rotator and namer to customize log
rotation processing: 31ca.


File: python.info,  Node: RotatingFileHandler,  Next: TimedRotatingFileHandler,  Prev: BaseRotatingHandler,  Up: logging handlers — Logging handlers

5.16.6.6 RotatingFileHandler
............................

The *note RotatingFileHandler: 1929. class, located in the *note
logging.handlers: 8d. module, supports rotation of disk log files.

 -- Classe: logging.handlers.RotatingFileHandler (filename, mode='a',
          maxBytes=0, backupCount=0, encoding=None, delay=False,
          errors=None)

     Returns a new instance of the *note RotatingFileHandler: 1929.
     class.  The specified file is opened and used as the stream for
     logging.  If 'mode' is not specified, ‘'a'’ is used.  If 'encoding'
     is not ‘None’, it is used to open the file with that encoding.  If
     'delay' is true, then file opening is deferred until the first call
     to *note emit(): 31cd.  By default, the file grows indefinitely.
     If 'errors' is provided, it determines how encoding errors are
     handled.

     You can use the 'maxBytes' and 'backupCount' values to allow the
     file to 'rollover' at a predetermined size.  When the size is about
     to be exceeded, the file is closed and a new file is silently
     opened for output.  Rollover occurs whenever the current log file
     is nearly 'maxBytes' in length; but if either of 'maxBytes' or
     'backupCount' is zero, rollover never occurs, so you generally want
     to set 'backupCount' to at least 1, and have a non-zero 'maxBytes'.
     When 'backupCount' is non-zero, the system will save old log files
     by appending the extensions “.1”, “.2” etc., to the filename.  For
     example, with a 'backupCount' of 5 and a base file name of
     ‘app.log’, you would get ‘app.log’, ‘app.log.1’, ‘app.log.2’, up to
     ‘app.log.5’.  The file being written to is always ‘app.log’.  When
     this file is filled, it is closed and renamed to ‘app.log.1’, and
     if files ‘app.log.1’, ‘app.log.2’, etc.  exist, then they are
     renamed to ‘app.log.2’, ‘app.log.3’ etc.  respectively.

     Cambiato nella versione 3.6: As well as string values, *note Path:
     266. objects are also accepted for the 'filename' argument.

     Cambiato nella versione 3.9: The 'errors' parameter was added.

      -- Metodo: doRollover ()

          Does a rollover, as described above.

      -- Metodo: emit (record)

          Outputs the record to the file, catering for rollover as
          described previously.

      -- Metodo: shouldRollover (record)

          See if the supplied record would cause the file to exceed the
          configured size limit.


File: python.info,  Node: TimedRotatingFileHandler,  Next: SocketHandler,  Prev: RotatingFileHandler,  Up: logging handlers — Logging handlers

5.16.6.7 TimedRotatingFileHandler
.................................

The *note TimedRotatingFileHandler: 1163. class, located in the *note
logging.handlers: 8d. module, supports rotation of disk log files at
certain timed intervals.

 -- Classe: logging.handlers.TimedRotatingFileHandler (filename,
          when='h', interval=1, backupCount=0, encoding=None,
          delay=False, utc=False, atTime=None, errors=None)

     Returns a new instance of the *note TimedRotatingFileHandler: 1163.
     class.  The specified file is opened and used as the stream for
     logging.  On rotating it also sets the filename suffix.  Rotating
     happens based on the product of 'when' and 'interval'.

     You can use the 'when' to specify the type of 'interval'.  The list
     of possible values is below.  Note that they are not case
     sensitive.

     Value                Type of interval                 If/how 'atTime' is used
                                                           
     ------------------------------------------------------------------------------------
                                                           
     ‘'S'’                Seconds                          Ignored
                                                           
                                                           
     ‘'M'’                Minutes                          Ignored
                                                           
                                                           
     ‘'H'’                Hours                            Ignored
                                                           
                                                           
     ‘'D'’                Days                             Ignored
                                                           
                                                           
     ‘'W0'-'W6'’          Weekday (0=Monday)               Used to compute initial
                                                           rollover time
                                                           
                                                           
     ‘'midnight'’         Roll over at midnight, if        Used to compute initial
                          'atTime' not specified, else     rollover time
                          at time 'atTime'                 
                          

     When using weekday-based rotation, specify “W0” for Monday, “W1”
     for Tuesday, and so on up to “W6” for Sunday.  In this case, the
     value passed for 'interval' isn’t used.

     The system will save old log files by appending extensions to the
     filename.  The extensions are date-and-time based, using the
     strftime format ‘%Y-%m-%d_%H-%M-%S’ or a leading portion thereof,
     depending on the rollover interval.

     When computing the next rollover time for the first time (when the
     handler is created), the last modification time of an existing log
     file, or else the current time, is used to compute when the next
     rotation will occur.

     If the 'utc' argument is true, times in UTC will be used; otherwise
     local time is used.

     If 'backupCount' is nonzero, at most 'backupCount' files will be
     kept, and if more would be created when rollover occurs, the oldest
     one is deleted.  The deletion logic uses the interval to determine
     which files to delete, so changing the interval may leave old files
     lying around.

     If 'delay' is true, then file opening is deferred until the first
     call to *note emit(): 31d2.

     If 'atTime' is not ‘None’, it must be a ‘datetime.time’ instance
     which specifies the time of day when rollover occurs, for the cases
     where rollover is set to happen «at midnight» or «on a particular
     weekday».  Note that in these cases, the 'atTime' value is
     effectively used to compute the 'initial' rollover, and subsequent
     rollovers would be calculated via the normal interval calculation.

     If 'errors' is specified, it’s used to determine how encoding
     errors are handled.

          Nota: Calculation of the initial rollover time is done when
          the handler is initialised.  Calculation of subsequent
          rollover times is done only when rollover occurs, and rollover
          occurs only when emitting output.  If this is not kept in
          mind, it might lead to some confusion.  For example, if an
          interval of «every minute» is set, that does not mean you will
          always see log files with times (in the filename) separated by
          a minute; if, during application execution, logging output is
          generated more frequently than once a minute, 'then' you can
          expect to see log files with times separated by a minute.  If,
          on the other hand, logging messages are only output once every
          five minutes (say), then there will be gaps in the file times
          corresponding to the minutes where no output (and hence no
          rollover) occurred.

     Cambiato nella versione 3.4: 'atTime' parameter was added.

     Cambiato nella versione 3.6: As well as string values, *note Path:
     266. objects are also accepted for the 'filename' argument.

     Cambiato nella versione 3.9: The 'errors' parameter was added.

      -- Metodo: doRollover ()

          Does a rollover, as described above.

      -- Metodo: emit (record)

          Outputs the record to the file, catering for rollover as
          described above.

      -- Metodo: getFilesToDelete ()

          Returns a list of filenames which should be deleted as part of
          rollover.  These are the absolute paths of the oldest backup
          log files written by the handler.

      -- Metodo: shouldRollover (record)

          See if enough time has passed for a rollover to occur and if
          it has, compute the next rollover time.


File: python.info,  Node: SocketHandler,  Next: DatagramHandler,  Prev: TimedRotatingFileHandler,  Up: logging handlers — Logging handlers

5.16.6.8 SocketHandler
......................

The *note SocketHandler: 1164. class, located in the *note
logging.handlers: 8d. module, sends logging output to a network socket.
The base class uses a TCP socket.

 -- Classe: logging.handlers.SocketHandler (host, port)

     Returns a new instance of the *note SocketHandler: 1164. class
     intended to communicate with a remote machine whose address is
     given by 'host' and 'port'.

     Cambiato nella versione 3.4: If ‘port’ is specified as ‘None’, a
     Unix domain socket is created using the value in ‘host’ -
     otherwise, a TCP socket is created.

      -- Metodo: close ()

          Closes the socket.

      -- Metodo: emit ()

          Pickles the record’s attribute dictionary and writes it to the
          socket in binary format.  If there is an error with the
          socket, silently drops the packet.  If the connection was
          previously lost, re-establishes the connection.  To unpickle
          the record at the receiving end into a *note LogRecord: 11e8,
          use the *note makeLogRecord(): 3170. function.

      -- Metodo: handleError ()

          Handles an error which has occurred during *note emit(): 31d8.
          The most likely cause is a lost connection.  Closes the socket
          so that we can retry on the next event.

      -- Metodo: makeSocket ()

          This is a factory method which allows subclasses to define the
          precise type of socket they want.  The default implementation
          creates a TCP socket (*note socket.SOCK_STREAM: 14fb.).

      -- Metodo: makePickle (record)

          Pickles the record’s attribute dictionary in binary format
          with a length prefix, and returns it ready for transmission
          across the socket.  The details of this operation are
          equivalent to:

               data = pickle.dumps(record_attr_dict, 1)
               datalen = struct.pack('>L', len(data))
               return datalen + data

          Note that pickles aren’t completely secure.  If you are
          concerned about security, you may want to override this method
          to implement a more secure mechanism.  For example, you can
          sign pickles using HMAC and then verify them on the receiving
          end, or alternatively you can disable unpickling of global
          objects on the receiving end.

      -- Metodo: send (packet)

          Send a pickled byte-string 'packet' to the socket.  The format
          of the sent byte-string is as described in the documentation
          for *note makePickle(): 31db.

          This function allows for partial sends, which can happen when
          the network is busy.

      -- Metodo: createSocket ()

          Tries to create a socket; on failure, uses an exponential
          back-off algorithm.  On initial failure, the handler will drop
          the message it was trying to send.  When subsequent messages
          are handled by the same instance, it will not try connecting
          until some time has passed.  The default parameters are such
          that the initial delay is one second, and if after that delay
          the connection still can’t be made, the handler will double
          the delay each time up to a maximum of 30 seconds.

          This behaviour is controlled by the following handler
          attributes:

             * ‘retryStart’ (initial delay, defaulting to 1.0 seconds).

             * ‘retryFactor’ (multiplier, defaulting to 2.0).

             * ‘retryMax’ (maximum delay, defaulting to 30.0 seconds).

          This means that if the remote listener starts up 'after' the
          handler has been used, you could lose messages (since the
          handler won’t even attempt a connection until the delay has
          elapsed, but just silently drop messages during the delay
          period).


File: python.info,  Node: DatagramHandler,  Next: SysLogHandler,  Prev: SocketHandler,  Up: logging handlers — Logging handlers

5.16.6.9 DatagramHandler
........................

The *note DatagramHandler: 1165. class, located in the *note
logging.handlers: 8d. module, inherits from *note SocketHandler: 1164.
to support sending logging messages over UDP sockets.

 -- Classe: logging.handlers.DatagramHandler (host, port)

     Returns a new instance of the *note DatagramHandler: 1165. class
     intended to communicate with a remote machine whose address is
     given by 'host' and 'port'.

          Nota: As UDP is not a streaming protocol, there is no
          persistent connection between an instance of this handler and
          'host'.  For this reason, when using a network socket, a DNS
          lookup might have to be made each time an event is logged,
          which can introduce some latency into the system.  If this
          affects you, you can do a lookup yourself and initialize this
          handler using the looked-up IP address rather than the
          hostname.

     Cambiato nella versione 3.4: If ‘port’ is specified as ‘None’, a
     Unix domain socket is created using the value in ‘host’ -
     otherwise, a UDP socket is created.

      -- Metodo: emit ()

          Pickles the record’s attribute dictionary and writes it to the
          socket in binary format.  If there is an error with the
          socket, silently drops the packet.  To unpickle the record at
          the receiving end into a *note LogRecord: 11e8, use the *note
          makeLogRecord(): 3170. function.

      -- Metodo: makeSocket ()

          The factory method of *note SocketHandler: 1164. is here
          overridden to create a UDP socket (*note socket.SOCK_DGRAM:
          14fa.).

      -- Metodo: send (s)

          Send a pickled byte-string to a socket.  The format of the
          sent byte-string is as described in the documentation for
          *note SocketHandler.makePickle(): 31db.


File: python.info,  Node: SysLogHandler,  Next: NTEventLogHandler,  Prev: DatagramHandler,  Up: logging handlers — Logging handlers

5.16.6.10 SysLogHandler
.......................

The *note SysLogHandler: 86d. class, located in the *note
logging.handlers: 8d. module, supports sending logging messages to a
remote or local Unix syslog.

 -- Classe: logging.handlers.SysLogHandler (address=('localhost',
          SYSLOG_UDP_PORT), facility=LOG_USER,
          socktype=socket.SOCK_DGRAM, timeout=None)

     Returns a new instance of the *note SysLogHandler: 86d. class
     intended to communicate with a remote Unix machine whose address is
     given by 'address' in the form of a ‘(host, port)’ tuple.  If
     'address' is not specified, ‘('localhost', 514)’ is used.  The
     address is used to open a socket.  An alternative to providing a
     ‘(host, port)’ tuple is providing an address as a string, for
     example “/dev/log”.  In this case, a Unix domain socket is used to
     send the message to the syslog.  If 'facility' is not specified,
     ‘LOG_USER’ is used.  The type of socket opened depends on the
     'socktype' argument, which defaults to *note socket.SOCK_DGRAM:
     14fa. and thus opens a UDP socket.  To open a TCP socket (for use
     with the newer syslog daemons such as rsyslog), specify a value of
     *note socket.SOCK_STREAM: 14fb.  If 'timeout' is specified, it sets
     a timeout (in seconds) for the socket operations.  This can help
     prevent the program from hanging indefinitely if the syslog server
     is unreachable.  By default, 'timeout' is ‘None’, meaning no
     timeout is applied.

     Note that if your server is not listening on UDP port 514, *note
     SysLogHandler: 86d. may appear not to work.  In that case, check
     what address you should be using for a domain socket - it’s system
     dependent.  For example, on Linux it’s usually “/dev/log” but on
     OS/X it’s “/var/run/syslog”.  You’ll need to check your platform
     and use the appropriate address (you may need to do this check at
     runtime if your application needs to run on several platforms).  On
     Windows, you pretty much have to use the UDP option.

          Nota: On macOS 12.x (Monterey), Apple has changed the
          behaviour of their syslog daemon - it no longer listens on a
          domain socket.  Therefore, you cannot expect *note
          SysLogHandler: 86d. to work on this system.

          See gh-91070(1) for more information.

     Cambiato nella versione 3.2: 'socktype' was added.

     Cambiato nella versione 3.14: 'timeout' was added.

      -- Metodo: close ()

          Closes the socket to the remote host.

      -- Metodo: createSocket ()

          Tries to create a socket and, if it’s not a datagram socket,
          connect it to the other end.  This method is called during
          handler initialization, but it’s not regarded as an error if
          the other end isn’t listening at this point - the method will
          be called again when emitting an event, if there is no socket
          at that point.

          Added in version 3.11.

      -- Metodo: emit (record)

          The record is formatted, and then sent to the syslog server.
          If exception information is present, it is 'not' sent to the
          server.

          Cambiato nella versione 3.2.1: (See: bpo-12168(2).)  In
          earlier versions, the message sent to the syslog daemons was
          always terminated with a NUL byte, because early versions of
          these daemons expected a NUL terminated message - even though
          it’s not in the relevant specification ( RFC 5424(3)).  More
          recent versions of these daemons don’t expect the NUL byte but
          strip it off if it’s there, and even more recent daemons
          (which adhere more closely to RFC 5424) pass the NUL byte on
          as part of the message.

          To enable easier handling of syslog messages in the face of
          all these differing daemon behaviours, the appending of the
          NUL byte has been made configurable, through the use of a
          class-level attribute, ‘append_nul’.  This defaults to ‘True’
          (preserving the existing behaviour) but can be set to ‘False’
          on a ‘SysLogHandler’ instance in order for that instance to
          'not' append the NUL terminator.

          Cambiato nella versione 3.3: (See: bpo-12419(4).)  In earlier
          versions, there was no facility for an «ident» or «tag» prefix
          to identify the source of the message.  This can now be
          specified using a class-level attribute, defaulting to ‘""’ to
          preserve existing behaviour, but which can be overridden on a
          ‘SysLogHandler’ instance in order for that instance to prepend
          the ident to every message handled.  Note that the provided
          ident must be text, not bytes, and is prepended to the message
          exactly as is.

      -- Metodo: encodePriority (facility, priority)

          Encodes the facility and priority into an integer.  You can
          pass in strings or integers - if strings are passed, internal
          mapping dictionaries are used to convert them to integers.

          The symbolic ‘LOG_’ values are defined in *note SysLogHandler:
          86d. and mirror the values defined in the ‘sys/syslog.h’
          header file.

          'Priorities'

          Name (string)                  Symbolic value
                                         
          ---------------------------------------------------
                                         
          ‘alert’                        LOG_ALERT
                                         
                                         
          ‘crit’ or ‘critical’           LOG_CRIT
                                         
                                         
          ‘debug’                        LOG_DEBUG
                                         
                                         
          ‘emerg’ or ‘panic’             LOG_EMERG
                                         
                                         
          ‘err’ or ‘error’               LOG_ERR
                                         
                                         
          ‘info’                         LOG_INFO
                                         
                                         
          ‘notice’                       LOG_NOTICE
                                         
                                         
          ‘warn’ or ‘warning’            LOG_WARNING
                                         

          'Facilities'

          Name (string)       Symbolic value
                              
          ----------------------------------------
                              
          ‘auth’              LOG_AUTH
                              
                              
          ‘authpriv’          LOG_AUTHPRIV
                              
                              
          ‘cron’              LOG_CRON
                              
                              
          ‘daemon’            LOG_DAEMON
                              
                              
          ‘ftp’               LOG_FTP
                              
                              
          ‘kern’              LOG_KERN
                              
                              
          ‘lpr’               LOG_LPR
                              
                              
          ‘mail’              LOG_MAIL
                              
                              
          ‘news’              LOG_NEWS
                              
                              
          ‘syslog’            LOG_SYSLOG
                              
                              
          ‘user’              LOG_USER
                              
                              
          ‘uucp’              LOG_UUCP
                              
                              
          ‘local0’            LOG_LOCAL0
                              
                              
          ‘local1’            LOG_LOCAL1
                              
                              
          ‘local2’            LOG_LOCAL2
                              
                              
          ‘local3’            LOG_LOCAL3
                              
                              
          ‘local4’            LOG_LOCAL4
                              
                              
          ‘local5’            LOG_LOCAL5
                              
                              
          ‘local6’            LOG_LOCAL6
                              
                              
          ‘local7’            LOG_LOCAL7
                              

      -- Metodo: mapPriority (levelname)

          Maps a logging level name to a syslog priority name.  You may
          need to override this if you are using custom levels, or if
          the default algorithm is not suitable for your needs.  The
          default algorithm maps ‘DEBUG’, ‘INFO’, ‘WARNING’, ‘ERROR’ and
          ‘CRITICAL’ to the equivalent syslog names, and all other level
          names to “warning”.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91070

   (2) https://bugs.python.org/issue?@action=redirect&bpo=12168

   (3) https://datatracker.ietf.org/doc/html/rfc5424.html

   (4) https://bugs.python.org/issue?@action=redirect&bpo=12419


File: python.info,  Node: NTEventLogHandler,  Next: SMTPHandler,  Prev: SysLogHandler,  Up: logging handlers — Logging handlers

5.16.6.11 NTEventLogHandler
...........................

The *note NTEventLogHandler: 31ea. class, located in the *note
logging.handlers: 8d. module, supports sending logging messages to a
local Windows NT, Windows 2000 or Windows XP event log.  Before you can
use it, you need Mark Hammond’s Win32 extensions for Python installed.

 -- Classe: logging.handlers.NTEventLogHandler (appname, dllname=None,
          logtype='Application')

     Returns a new instance of the *note NTEventLogHandler: 31ea. class.
     The 'appname' is used to define the application name as it appears
     in the event log.  An appropriate registry entry is created using
     this name.  The 'dllname' should give the fully qualified pathname
     of a .dll or .exe which contains message definitions to hold in the
     log (if not specified, ‘'win32service.pyd'’ is used - this is
     installed with the Win32 extensions and contains some basic
     placeholder message definitions.  Note that use of these
     placeholders will make your event logs big, as the entire message
     source is held in the log.  If you want slimmer logs, you have to
     pass in the name of your own .dll or .exe which contains the
     message definitions you want to use in the event log).  The
     'logtype' is one of ‘'Application'’, ‘'System'’ or ‘'Security'’,
     and defaults to ‘'Application'’.

      -- Metodo: close ()

          At this point, you can remove the application name from the
          registry as a source of event log entries.  However, if you do
          this, you will not be able to see the events as you intended
          in the Event Log Viewer - it needs to be able to access the
          registry to get the .dll name.  The current version does not
          do this.

      -- Metodo: emit (record)

          Determines the message ID, event category and event type, and
          then logs the message in the NT event log.

      -- Metodo: getEventCategory (record)

          Returns the event category for the record.  Override this if
          you want to specify your own categories.  This version returns
          0.

      -- Metodo: getEventType (record)

          Returns the event type for the record.  Override this if you
          want to specify your own types.  This version does a mapping
          using the handler’s typemap attribute, which is set up in
          ‘__init__()’ to a dictionary which contains mappings for
          ‘DEBUG’, ‘INFO’, ‘WARNING’, ‘ERROR’ and ‘CRITICAL’.  If you
          are using your own levels, you will either need to override
          this method or place a suitable dictionary in the handler’s
          'typemap' attribute.

      -- Metodo: getMessageID (record)

          Returns the message ID for the record.  If you are using your
          own messages, you could do this by having the 'msg' passed to
          the logger being an ID rather than a format string.  Then, in
          here, you could use a dictionary lookup to get the message ID.
          This version returns 1, which is the base message ID in
          ‘win32service.pyd’.


File: python.info,  Node: SMTPHandler,  Next: MemoryHandler,  Prev: NTEventLogHandler,  Up: logging handlers — Logging handlers

5.16.6.12 SMTPHandler
.....................

The *note SMTPHandler: 189a. class, located in the *note
logging.handlers: 8d. module, supports sending logging messages to an
email address via SMTP.

 -- Classe: logging.handlers.SMTPHandler (mailhost, fromaddr, toaddrs,
          subject, credentials=None, secure=None, timeout=1.0)

     Returns a new instance of the *note SMTPHandler: 189a. class.  The
     instance is initialized with the from and to addresses and subject
     line of the email.  The 'toaddrs' should be a list of strings.  To
     specify a non-standard SMTP port, use the (host, port) tuple format
     for the 'mailhost' argument.  If you use a string, the standard
     SMTP port is used.  If your SMTP server requires authentication,
     you can specify a (username, password) tuple for the 'credentials'
     argument.

     To specify the use of a secure protocol (TLS), pass in a tuple to
     the 'secure' argument.  This will only be used when authentication
     credentials are supplied.  The tuple should be either an empty
     tuple, or a single-value tuple with the name of a keyfile, or a
     2-value tuple with the names of the keyfile and certificate file.
     (This tuple is passed to the *note smtplib.SMTP.starttls(): 1340.
     method.)

     A timeout can be specified for communication with the SMTP server
     using the 'timeout' argument.

     Cambiato nella versione 3.3: Added the 'timeout' parameter.

      -- Metodo: emit (record)

          Formats the record and sends it to the specified addressees.

      -- Metodo: getSubject (record)

          If you want to specify a subject line which is
          record-dependent, override this method.


File: python.info,  Node: MemoryHandler,  Next: HTTPHandler,  Prev: SMTPHandler,  Up: logging handlers — Logging handlers

5.16.6.13 MemoryHandler
.......................

The *note MemoryHandler: 31a3. class, located in the *note
logging.handlers: 8d. module, supports buffering of logging records in
memory, periodically flushing them to a 'target' handler.  Flushing
occurs whenever the buffer is full, or when an event of a certain
severity or greater is seen.

*note MemoryHandler: 31a3. is a subclass of the more general *note
BufferingHandler: 31f6, which is an abstract class.  This buffers
logging records in memory.  Whenever each record is added to the buffer,
a check is made by calling ‘shouldFlush()’ to see if the buffer should
be flushed.  If it should, then ‘flush()’ is expected to do the
flushing.

 -- Classe: logging.handlers.BufferingHandler (capacity)

     Initializes the handler with a buffer of the specified capacity.
     Here, 'capacity' means the number of logging records buffered.

      -- Metodo: emit (record)

          Append the record to the buffer.  If *note shouldFlush():
          31f8. returns true, call *note flush(): 31f9. to process the
          buffer.

      -- Metodo: flush ()

          For a *note BufferingHandler: 31f6. instance, flushing means
          that it sets the buffer to an empty list.  This method can be
          overwritten to implement more useful flushing behavior.

      -- Metodo: shouldFlush (record)

          Return ‘True’ if the buffer is up to capacity.  This method
          can be overridden to implement custom flushing strategies.

 -- Classe: logging.handlers.MemoryHandler (capacity, flushLevel=ERROR,
          target=None, flushOnClose=True)

     Returns a new instance of the *note MemoryHandler: 31a3. class.
     The instance is initialized with a buffer size of 'capacity'
     (number of records buffered).  If 'flushLevel' is not specified,
     ‘ERROR’ is used.  If no 'target' is specified, the target will need
     to be set using *note setTarget(): 31fa. before this handler does
     anything useful.  If 'flushOnClose' is specified as ‘False’, then
     the buffer is 'not' flushed when the handler is closed.  If not
     specified or specified as ‘True’, the previous behaviour of
     flushing the buffer will occur when the handler is closed.

     Cambiato nella versione 3.6: The 'flushOnClose' parameter was
     added.

      -- Metodo: close ()

          Calls *note flush(): 31fc, sets the target to ‘None’ and
          clears the buffer.

      -- Metodo: flush ()

          For a *note MemoryHandler: 31a3. instance, flushing means just
          sending the buffered records to the target, if there is one.
          The buffer is also cleared when buffered records are sent to
          the target.  Override if you want different behavior.

      -- Metodo: setTarget (target)

          Sets the target handler for this handler.

      -- Metodo: shouldFlush (record)

          Checks for buffer full or a record at the 'flushLevel' or
          higher.


File: python.info,  Node: HTTPHandler,  Next: QueueHandler,  Prev: MemoryHandler,  Up: logging handlers — Logging handlers

5.16.6.14 HTTPHandler
.....................

The *note HTTPHandler: 102e. class, located in the *note
logging.handlers: 8d. module, supports sending logging messages to a web
server, using either ‘GET’ or ‘POST’ semantics.

 -- Classe: logging.handlers.HTTPHandler (host, url, method='GET',
          secure=False, credentials=None, context=None)

     Returns a new instance of the *note HTTPHandler: 102e. class.  The
     'host' can be of the form ‘host:port’, should you need to use a
     specific port number.  If no 'method' is specified, ‘GET’ is used.
     If 'secure' is true, a HTTPS connection will be used.  The
     'context' parameter may be set to a *note ssl.SSLContext: 357.
     instance to configure the SSL settings used for the HTTPS
     connection.  If 'credentials' is specified, it should be a 2-tuple
     consisting of userid and password, which will be placed in a HTTP
     “Authorization” header using Basic authentication.  If you specify
     credentials, you should also specify secure=True so that your
     userid and password are not passed in cleartext across the wire.

     Cambiato nella versione 3.5: The 'context' parameter was added.

      -- Metodo: mapLogRecord (record)

          Provides a dictionary, based on ‘record’, which is to be
          URL-encoded and sent to the web server.  The default
          implementation just returns ‘record.__dict__’.  This method
          can be overridden if e.g.  only a subset of *note LogRecord:
          11e8. is to be sent to the web server, or if more specific
          customization of what’s sent to the server is required.

      -- Metodo: emit (record)

          Sends the record to the web server as a URL-encoded
          dictionary.  The *note mapLogRecord(): 3200. method is used to
          convert the record to the dictionary to be sent.

          Nota: Since preparing a record for sending it to a web server
          is not the same as a generic formatting operation, using *note
          setFormatter(): 3154. to specify a *note Formatter: 169e. for
          a *note HTTPHandler: 102e. has no effect.  Instead of calling
          *note format(): 315d, this handler calls *note mapLogRecord():
          3200. and then *note urllib.parse.urlencode(): 1097. to encode
          the dictionary in a form suitable for sending to a web server.


File: python.info,  Node: QueueHandler,  Next: QueueListener,  Prev: HTTPHandler,  Up: logging handlers — Logging handlers

5.16.6.15 QueueHandler
......................

Added in version 3.2.

The *note QueueHandler: 1b49. class, located in the *note
logging.handlers: 8d. module, supports sending logging messages to a
queue, such as those implemented in the *note queue: bb. or *note
multiprocessing: 98. modules.

Along with the *note QueueListener: 242. class, *note QueueHandler:
1b49. can be used to let handlers do their work on a separate thread
from the one which does the logging.  This is important in web
applications and also other service applications where threads servicing
clients need to respond as quickly as possible, while any potentially
slow operations (such as sending an email via *note SMTPHandler: 189a.)
are done on a separate thread.

 -- Classe: logging.handlers.QueueHandler (queue)

     Returns a new instance of the *note QueueHandler: 1b49. class.  The
     instance is initialized with the queue to send messages to.  The
     'queue' can be any queue-like object; it’s used as-is by the *note
     enqueue(): 3204. method, which needs to know how to send messages
     to it.  The queue is not 'required' to have the task tracking API,
     which means that you can use *note SimpleQueue: d63. instances for
     'queue'.

          Nota: If you are using *note multiprocessing: 98, you should
          avoid using *note SimpleQueue: d63. and instead use *note
          multiprocessing.Queue: 1b71.

          Avvertimento: The *note multiprocessing: 98. module uses an
          internal logger created and accessed via *note get_logger():
          3205.  *note multiprocessing.Queue: 1b71. will log ‘DEBUG’
          level messages upon items being queued.  If those log messages
          are processed by a *note QueueHandler: 1b49. using the same
          *note multiprocessing.Queue: 1b71. instance, it will cause a
          deadlock or infinite recursion.

      -- Metodo: emit (record)

          Enqueues the result of preparing the LogRecord.  Should an
          exception occur (e.g.  because a bounded queue has filled up),
          the *note handleError(): 315b. method is called to handle the
          error.  This can result in the record silently being dropped
          (if *note logging.raiseExceptions: 1401. is ‘False’) or a
          message printed to ‘sys.stderr’ (if *note
          logging.raiseExceptions: 1401. is ‘True’).

      -- Metodo: prepare (record)

          Prepares a record for queuing.  The object returned by this
          method is enqueued.

          The base implementation formats the record to merge the
          message, arguments, exception and stack information, if
          present.  It also removes unpickleable items from the record
          in-place.  Specifically, it overwrites the record’s ‘msg’ and
          ‘message’ attributes with the merged message (obtained by
          calling the handler’s *note format(): 199. method), and sets
          the ‘args’, ‘exc_info’ and ‘exc_text’ attributes to ‘None’.

          You might want to override this method if you want to convert
          the record to a dict or JSON string, or send a modified copy
          of the record while leaving the original intact.

               Nota: The base implementation formats the message with
               arguments, sets the ‘message’ and ‘msg’ attributes to the
               formatted message and sets the ‘args’ and ‘exc_text’
               attributes to ‘None’ to allow pickling and to prevent
               further attempts at formatting.  This means that a
               handler on the *note QueueListener: 242. side won’t have
               the information to do custom formatting, e.g.  of
               exceptions.  You may wish to subclass ‘QueueHandler’ and
               override this method to e.g.  avoid setting ‘exc_text’ to
               ‘None’.  Note that the ‘message’ / ‘msg’ / ‘args’ changes
               are related to ensuring the record is pickleable, and you
               might or might not be able to avoid doing that depending
               on whether your ‘args’ are pickleable.  (Note that you
               may have to consider not only your own code but also code
               in any libraries that you use.)

      -- Metodo: enqueue (record)

          Enqueues the record on the queue using ‘put_nowait()’; you may
          want to override this if you want to use blocking behaviour,
          or a timeout, or a customized queue implementation.

      -- Attributo: listener

          When created via configuration using *note dictConfig(): 13b8,
          this attribute will contain a *note QueueListener: 242.
          instance for use with this handler.  Otherwise, it will be
          ‘None’.

          Added in version 3.12.


File: python.info,  Node: QueueListener,  Prev: QueueHandler,  Up: logging handlers — Logging handlers

5.16.6.16 QueueListener
.......................

Added in version 3.2.

The *note QueueListener: 242. class, located in the *note
logging.handlers: 8d. module, supports receiving logging messages from a
queue, such as those implemented in the *note queue: bb. or *note
multiprocessing: 98. modules.  The messages are received from a queue in
an internal thread and passed, on the same thread, to one or more
handlers for processing.  While *note QueueListener: 242. is not itself
a handler, it is documented here because it works hand-in-hand with
*note QueueHandler: 1b49.

Along with the *note QueueHandler: 1b49. class, *note QueueListener:
242. can be used to let handlers do their work on a separate thread from
the one which does the logging.  This is important in web applications
and also other service applications where threads servicing clients need
to respond as quickly as possible, while any potentially slow operations
(such as sending an email via *note SMTPHandler: 189a.) are done on a
separate thread.

 -- Classe: logging.handlers.QueueListener (queue, *handlers,
          respect_handler_level=False)

     Returns a new instance of the *note QueueListener: 242. class.  The
     instance is initialized with the queue to send messages to and a
     list of handlers which will handle entries placed on the queue.
     The queue can be any queue-like object; it’s passed as-is to the
     *note dequeue(): 320a. method, which needs to know how to get
     messages from it.  The queue is not 'required' to have the task
     tracking API (though it’s used if available), which means that you
     can use *note SimpleQueue: d63. instances for 'queue'.

          Nota: If you are using *note multiprocessing: 98, you should
          avoid using *note SimpleQueue: d63. and instead use *note
          multiprocessing.Queue: 1b71.

     If ‘respect_handler_level’ is ‘True’, a handler’s level is
     respected (compared with the level for the message) when deciding
     whether to pass messages to that handler; otherwise, the behaviour
     is as in previous Python versions - to always pass each message to
     each handler.

     Cambiato nella versione 3.5: The ‘respect_handler_level’ argument
     was added.

     Cambiato nella versione 3.14: *note QueueListener: 242. can now be
     used as a context manager via *note with: 186.  When entering the
     context, the listener is started.  When exiting the context, the
     listener is stopped.  *note __enter__(): 268b. returns the *note
     QueueListener: 242. object.

      -- Metodo: dequeue (block)

          Dequeues a record and return it, optionally blocking.

          The base implementation uses ‘get()’.  You may want to
          override this method if you want to use timeouts or work with
          custom queue implementations.

      -- Metodo: prepare (record)

          Prepare a record for handling.

          This implementation just returns the passed-in record.  You
          may want to override this method if you need to do any custom
          marshalling or manipulation of the record before passing it to
          the handlers.

      -- Metodo: handle (record)

          Handle a record.

          This just loops through the handlers offering them the record
          to handle.  The actual object passed to the handlers is that
          which is returned from *note prepare(): 320b.

      -- Metodo: start ()

          Starts the listener.

          This starts up a background thread to monitor the queue for
          LogRecords to process.

          Cambiato nella versione 3.14: Raises *note RuntimeError: 244.
          if called and the listener is already running.

      -- Metodo: stop ()

          Stops the listener.

          This asks the thread to terminate, and then waits for it to do
          so.  Note that if you don’t call this before your application
          exits, there may be some records still left on the queue,
          which won’t be processed.

      -- Metodo: enqueue_sentinel ()

          Writes a sentinel to the queue to tell the listener to quit.
          This implementation uses ‘put_nowait()’.  You may want to
          override this method if you want to use timeouts or work with
          custom queue implementations.

          Added in version 3.3.

Vedi anche
..........

Module *note logging: 8b.

     API reference for the logging module.

Module *note logging.config: 8c.

     Configuration API for the logging module.


File: python.info,  Node: platform — Access to underlying platform’s identifying data,  Next: errno — Standard errno system symbols,  Prev: logging handlers — Logging handlers,  Up: Generic Operating System Services

5.16.7 ‘platform’ — Access to underlying platform’s identifying data
--------------------------------------------------------------------

'Source code:' Lib/platform.py(1)

__________________________________________________________________

     Nota: Specific platforms listed alphabetically, with Linux included
     in the Unix section.

* Menu:

* Cross platform::
* Java platform::
* Windows platform::
* macOS platform::
* iOS platform::
* Unix platforms::
* Linux platforms::
* Android platform::
* Command-line usage: Command-line usage<3>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/platform.py


File: python.info,  Node: Cross platform,  Next: Java platform,  Up: platform — Access to underlying platform’s identifying data

5.16.7.1 Cross platform
.......................

 -- Funzione: platform.architecture (executable=sys.executable, bits='',
          linkage='')

     Queries the given executable (defaults to the Python interpreter
     binary) for various architecture information.

     Returns a tuple ‘(bits, linkage)’ which contain information about
     the bit architecture and the linkage format used for the
     executable.  Both values are returned as strings.

     Values that cannot be determined are returned as given by the
     parameter presets.  If bits is given as ‘''’, the ‘sizeof(pointer)’
     (or ‘sizeof(long)’ on Python version < 1.5.2) is used as indicator
     for the supported pointer size.

     The function relies on the system’s ‘file’ command to do the actual
     work.  This is available on most if not all Unix platforms and some
     non-Unix platforms and then only if the executable points to the
     Python interpreter.  Reasonable defaults are used when the above
     needs are not met.

          Nota: On macOS (and perhaps other platforms), executable files
          may be universal files containing multiple architectures.

          To get at the «64-bitness» of the current interpreter, it is
          more reliable to query the *note sys.maxsize: 13cd. attribute:

               is_64bits = sys.maxsize > 2**32

 -- Funzione: platform.machine ()

     Returns the machine type, e.g.  ‘'AMD64'’.  An empty string is
     returned if the value cannot be determined.

     The output is platform-dependent and may differ in casing and
     naming conventions.

 -- Funzione: platform.node ()

     Returns the computer’s network name (may not be fully qualified!).
     An empty string is returned if the value cannot be determined.

 -- Funzione: platform.platform (aliased=False, terse=False)

     Returns a single string identifying the underlying platform with as
     much useful information as possible.

     The output is intended to be 'human readable' rather than machine
     parseable.  It may look different on different platforms and this
     is intended.

     If 'aliased' is true, the function will use aliases for various
     platforms that report system names which differ from their common
     names, for example SunOS will be reported as Solaris.  The *note
     system_alias(): 3215. function is used to implement this.

     Setting 'terse' to true causes the function to return only the
     absolute minimum information needed to identify the platform.

     Cambiato nella versione 3.8: On macOS, the function now uses *note
     mac_ver(): 1dfd, if it returns a non-empty release string, to get
     the macOS version rather than the darwin version.

 -- Funzione: platform.processor ()

     Returns the (real) processor name, e.g.  ‘'amdk6'’.

     An empty string is returned if the value cannot be determined.
     Note that many platforms do not provide this information or simply
     return the same value as for *note machine(): 3213.  NetBSD does
     this.

 -- Funzione: platform.python_build ()

     Returns a tuple ‘(buildno, builddate)’ stating the Python build
     number and date as strings.

 -- Funzione: platform.python_compiler ()

     Returns a string identifying the compiler used for compiling
     Python.

 -- Funzione: platform.python_branch ()

     Returns a string identifying the Python implementation SCM branch.

 -- Funzione: platform.python_implementation ()

     Returns a string identifying the Python implementation.  Possible
     return values are: “CPython”, “IronPython”, “Jython”, “PyPy”.

 -- Funzione: platform.python_revision ()

     Returns a string identifying the Python implementation SCM
     revision.

 -- Funzione: platform.python_version ()

     Returns the Python version as string ‘'major.minor.patchlevel'’.

     Note that unlike the Python ‘sys.version’, the returned value will
     always include the patchlevel (it defaults to 0).

 -- Funzione: platform.python_version_tuple ()

     Returns the Python version as tuple ‘(major, minor, patchlevel)’ of
     strings.

     Note that unlike the Python ‘sys.version’, the returned value will
     always include the patchlevel (it defaults to ‘'0'’).

 -- Funzione: platform.release ()

     Returns the system’s release, e.g.  ‘'2.2.0'’ or ‘'NT'’.  An empty
     string is returned if the value cannot be determined.

 -- Funzione: platform.system ()

     Returns the system/OS name, such as ‘'Linux'’, ‘'Darwin'’,
     ‘'Java'’, ‘'Windows'’.  An empty string is returned if the value
     cannot be determined.

     On iOS and Android, this returns the user-facing OS name (i.e,
     ‘'iOS’, ‘'iPadOS'’ or ‘'Android'’).  To obtain the kernel name
     (‘'Darwin'’ or ‘'Linux'’), use *note os.uname(): 131e.

 -- Funzione: platform.system_alias (system, release, version)

     Returns ‘(system, release, version)’ aliased to common marketing
     names used for some systems.  It also does some reordering of the
     information in some cases where it would otherwise cause confusion.

 -- Funzione: platform.version ()

     Returns the system’s release version, e.g.  ‘'#3 on degas'’.  An
     empty string is returned if the value cannot be determined.

     On iOS and Android, this is the user-facing OS version.  To obtain
     the Darwin or Linux kernel version, use *note os.uname(): 131e.

 -- Funzione: platform.uname ()

     Fairly portable uname interface.  Returns a *note namedtuple():
     4e1. containing six attributes: *note system: 2250, *note node:
     3214, *note release: 321e, *note version: 321f, *note machine:
     3213, and *note processor: 3216.

     *note processor: 3216. is resolved late, on demand.

     Note: the first two attribute names differ from the names presented
     by *note os.uname(): 131e, where they are named ‘sysname’ and
     ‘nodename’.

     Entries which cannot be determined are set to ‘''’.

     Cambiato nella versione 3.3: Result changed from a tuple to a *note
     namedtuple(): 4e1.

     Cambiato nella versione 3.9: *note processor: 3216. is resolved
     late instead of immediately.

 -- Funzione: platform.invalidate_caches ()

     Clear out the internal cache of information, such as the *note
     uname(): 1dfb.  This is typically useful when the platform’s *note
     node(): 3214. is changed by an external process and one needs to
     retrieve the updated value.

     Added in version 3.14.


File: python.info,  Node: Java platform,  Next: Windows platform,  Prev: Cross platform,  Up: platform — Access to underlying platform’s identifying data

5.16.7.2 Java platform
......................

 -- Funzione: platform.java_ver (release='', vendor='', vminfo=('', '',
          ''), osinfo=('', '', ''))

     Version interface for Jython.

     Returns a tuple ‘(release, vendor, vminfo, osinfo)’ with 'vminfo'
     being a tuple ‘(vm_name, vm_release, vm_vendor)’ and 'osinfo' being
     a tuple ‘(os_name, os_version, os_arch)’.  Values which cannot be
     determined are set to the defaults given as parameters (which all
     default to ‘''’).

     Deprecated since version 3.13, will be removed in version 3.15: It
     was largely untested, had a confusing API, and was only useful for
     Jython support.


File: python.info,  Node: Windows platform,  Next: macOS platform,  Prev: Java platform,  Up: platform — Access to underlying platform’s identifying data

5.16.7.3 Windows platform
.........................

 -- Funzione: platform.win32_ver (release='', version='', csd='',
          ptype='')

     Get additional version information from the Windows Registry and
     return a tuple ‘(release, version, csd, ptype)’ referring to OS
     release, version number, CSD level (service pack) and OS type
     (multi/single processor).  Values which cannot be determined are
     set to the defaults given as parameters (which all default to an
     empty string).

     As a hint: 'ptype' is ‘'Uniprocessor Free'’ on single processor NT
     machines and ‘'Multiprocessor Free'’ on multi processor machines.
     The ‘'Free'’ refers to the OS version being free of debugging code.
     It could also state ‘'Checked'’ which means the OS version uses
     debugging code, i.e.  code that checks arguments, ranges, etc.

 -- Funzione: platform.win32_edition ()

     Returns a string representing the current Windows edition, or
     ‘None’ if the value cannot be determined.  Possible values include
     but are not limited to ‘'Enterprise'’, ‘'IoTUAP'’,
     ‘'ServerStandard'’, and ‘'nanoserver'’.

     Added in version 3.8.

 -- Funzione: platform.win32_is_iot ()

     Return ‘True’ if the Windows edition returned by *note
     win32_edition(): 3222. is recognized as an IoT edition.

     Added in version 3.8.


File: python.info,  Node: macOS platform,  Next: iOS platform,  Prev: Windows platform,  Up: platform — Access to underlying platform’s identifying data

5.16.7.4 macOS platform
.......................

 -- Funzione: platform.mac_ver (release='', versioninfo=('', '', ''),
          machine='')

     Get macOS version information and return it as tuple ‘(release,
     versioninfo, machine)’ with 'versioninfo' being a tuple ‘(version,
     dev_stage, non_release_version)’.

     Entries which cannot be determined are set to ‘''’.  All tuple
     entries are strings.


File: python.info,  Node: iOS platform,  Next: Unix platforms,  Prev: macOS platform,  Up: platform — Access to underlying platform’s identifying data

5.16.7.5 iOS platform
.....................

 -- Funzione: platform.ios_ver (system='', release='', model='',
          is_simulator=False)

     Get iOS version information and return it as a *note namedtuple():
     4e1. with the following attributes:

        * ‘system’ is the OS name; either ‘'iOS'’ or ‘'iPadOS'’.

        * ‘release’ is the iOS version number as a string (e.g.,
          ‘'17.2'’).

        * ‘model’ is the device model identifier; this will be a string
          like ‘'iPhone13,2'’ for a physical device, or ‘'iPhone'’ on a
          simulator.

        * ‘is_simulator’ is a boolean describing if the app is running
          on a simulator or a physical device.

     Entries which cannot be determined are set to the defaults given as
     parameters.


File: python.info,  Node: Unix platforms,  Next: Linux platforms,  Prev: iOS platform,  Up: platform — Access to underlying platform’s identifying data

5.16.7.6 Unix platforms
.......................

 -- Funzione: platform.libc_ver (executable=sys.executable, lib='',
          version='', chunksize=16384)

     Tries to determine the libc version against which the file
     executable (defaults to the Python interpreter) is linked.  Returns
     a tuple of strings ‘(lib, version)’ which default to the given
     parameters in case the lookup fails.

     Note that this function has intimate knowledge of how different
     libc versions add symbols to the executable is probably only usable
     for executables compiled using ‘gcc’.

     The file is read and scanned in chunks of 'chunksize' bytes.


File: python.info,  Node: Linux platforms,  Next: Android platform,  Prev: Unix platforms,  Up: platform — Access to underlying platform’s identifying data

5.16.7.7 Linux platforms
........................

 -- Funzione: platform.freedesktop_os_release ()

     Get operating system identification from ‘os-release’ file and
     return it as a dict.  The ‘os-release’ file is a freedesktop.org
     standard(1) and is available in most Linux distributions.  A
     noticeable exception is Android and Android-based distributions.

     Raises *note OSError: 2c0. or subclass when neither
     ‘/etc/os-release’ nor ‘/usr/lib/os-release’ can be read.

     On success, the function returns a dictionary where keys and values
     are strings.  Values have their special characters like ‘"’ and ‘$’
     unquoted.  The fields ‘NAME’, ‘ID’, and ‘PRETTY_NAME’ are always
     defined according to the standard.  All other fields are optional.
     Vendors may include additional fields.

     Note that fields like ‘NAME’, ‘VERSION’, and ‘VARIANT’ are strings
     suitable for presentation to users.  Programs should use fields
     like ‘ID’, ‘ID_LIKE’, ‘VERSION_ID’, or ‘VARIANT_ID’ to identify
     Linux distributions.

     Example:

          def get_like_distro():
              info = platform.freedesktop_os_release()
              ids = [info["ID"]]
              if "ID_LIKE" in info:
                  # ids are space separated and ordered by precedence
                  ids.extend(info["ID_LIKE"].split())
              return ids

     Added in version 3.10.

   ---------- Footnotes ----------

   (1) https://www.freedesktop.org/software/systemd/man/os-release.html


File: python.info,  Node: Android platform,  Next: Command-line usage<3>,  Prev: Linux platforms,  Up: platform — Access to underlying platform’s identifying data

5.16.7.8 Android platform
.........................

 -- Funzione: platform.android_ver (release='', api_level=0,
          manufacturer='', model='', device='', is_emulator=False)

     Get Android device information.  Returns a *note namedtuple(): 4e1.
     with the following attributes.  Values which cannot be determined
     are set to the defaults given as parameters.

        * ‘release’ - Android version, as a string (e.g.  ‘"14"’).

        * ‘api_level’ - API level of the running device, as an integer
          (e.g.  ‘34’ for Android 14).  To get the API level which
          Python was built against, see *note sys.getandroidapilevel():
          d85.

        * ‘manufacturer’ - Manufacturer name(1).

        * ‘model’ - Model name(2) – typically the marketing name or
          model number.

        * ‘device’ - Device name(3) – typically the model number or a
          codename.

        * ‘is_emulator’ - ‘True’ if the device is an emulator; ‘False’
          if it’s a physical device.

     Google maintains a list of known model and device names(4).

     Added in version 3.13.

   ---------- Footnotes ----------

   (1) 
https://developer.android.com/reference/android/os/Build#MANUFACTURER

   (2) https://developer.android.com/reference/android/os/Build#MODEL

   (3) https://developer.android.com/reference/android/os/Build#DEVICE

   (4) https://storage.googleapis.com/play_public/supported_devices.html


File: python.info,  Node: Command-line usage<3>,  Prev: Android platform,  Up: platform — Access to underlying platform’s identifying data

5.16.7.9 Command-line usage
...........................

*note platform: af. can also be invoked directly using the *note -m:
23c. switch of the interpreter:

     python -m platform [--terse] [--nonaliased] [{nonaliased,terse} ...]

The following options are accepted:

 -- Option: --terse

     Print terse information about the platform.  This is equivalent to
     calling *note platform.platform(): 1aae. with the 'terse' argument
     set to ‘True’.

 -- Option: --nonaliased

     Print platform information without system/OS name aliasing.  This
     is equivalent to calling *note platform.platform(): 1aae. with the
     'aliased' argument set to ‘True’.

You can also pass one or more positional arguments (‘terse’,
‘nonaliased’) to explicitly control the output format.  These behave
similarly to their corresponding options.


File: python.info,  Node: errno — Standard errno system symbols,  Next: ctypes — A foreign function library for Python,  Prev: platform — Access to underlying platform’s identifying data,  Up: Generic Operating System Services

5.16.8 ‘errno’ — Standard errno system symbols
----------------------------------------------

__________________________________________________________________

This module makes available standard ‘errno’ system symbols.  The value
of each symbol is the corresponding integer value.  The names and
descriptions are borrowed from ‘linux/include/errno.h’, which should be
all-inclusive.

 -- Dati: errno.errorcode

     Dictionary providing a mapping from the errno value to the string
     name in the underlying system.  For instance,
     ‘errno.errorcode[errno.EPERM]’ maps to ‘'EPERM'’.

To translate a numeric error code to an error message, use *note
os.strerror(): 3009.

Of the following list, symbols that are not used on the current platform
are not defined by the module.  The specific list of defined symbols is
available as ‘errno.errorcode.keys()’.  Symbols available can include:

 -- Dati: errno.EPERM

     Operation not permitted.  This error is mapped to the exception
     *note PermissionError: f40.

 -- Dati: errno.ENOENT

     No such file or directory.  This error is mapped to the exception
     *note FileNotFoundError: 264.

 -- Dati: errno.ESRCH

     No such process.  This error is mapped to the exception *note
     ProcessLookupError: 125d.

 -- Dati: errno.EINTR

     Interrupted system call.  This error is mapped to the exception
     *note InterruptedError: f8a.

 -- Dati: errno.EIO

     I/O error

 -- Dati: errno.ENXIO

     No such device or address

 -- Dati: errno.E2BIG

     Arg list too long

 -- Dati: errno.ENOEXEC

     Exec format error

 -- Dati: errno.EBADF

     Bad file number

 -- Dati: errno.ECHILD

     No child processes.  This error is mapped to the exception *note
     ChildProcessError: 125a.

 -- Dati: errno.EAGAIN

     Try again.  This error is mapped to the exception *note
     BlockingIOError: 235.

 -- Dati: errno.ENOMEM

     Out of memory

 -- Dati: errno.EACCES

     Permission denied.  This error is mapped to the exception *note
     PermissionError: f40.

 -- Dati: errno.EFAULT

     Bad address

 -- Dati: errno.ENOTBLK

     Block device required

 -- Dati: errno.EBUSY

     Device or resource busy

 -- Dati: errno.EEXIST

     File exists.  This error is mapped to the exception *note
     FileExistsError: 1222.

 -- Dati: errno.EXDEV

     Cross-device link

 -- Dati: errno.ENODEV

     No such device

 -- Dati: errno.ENOTDIR

     Not a directory.  This error is mapped to the exception *note
     NotADirectoryError: 125c.

 -- Dati: errno.EISDIR

     Is a directory.  This error is mapped to the exception *note
     IsADirectoryError: 125b.

 -- Dati: errno.EINVAL

     Invalid argument

 -- Dati: errno.ENFILE

     File table overflow

 -- Dati: errno.EMFILE

     Too many open files

 -- Dati: errno.ENOTTY

     Not a typewriter

 -- Dati: errno.ETXTBSY

     Text file busy

 -- Dati: errno.EFBIG

     File too large

 -- Dati: errno.ENOSPC

     No space left on device

 -- Dati: errno.ESPIPE

     Illegal seek

 -- Dati: errno.EROFS

     Read-only file system

 -- Dati: errno.EMLINK

     Too many links

 -- Dati: errno.EPIPE

     Broken pipe.  This error is mapped to the exception *note
     BrokenPipeError: 125e.

 -- Dati: errno.EDOM

     Math argument out of domain of func

 -- Dati: errno.ERANGE

     Math result not representable

 -- Dati: errno.EDEADLK

     Resource deadlock would occur

 -- Dati: errno.ENAMETOOLONG

     File name too long

 -- Dati: errno.ENOLCK

     No record locks available

 -- Dati: errno.ENOSYS

     Function not implemented

 -- Dati: errno.ENOTEMPTY

     Directory not empty

 -- Dati: errno.ELOOP

     Too many symbolic links encountered

 -- Dati: errno.EWOULDBLOCK

     Operation would block.  This error is mapped to the exception *note
     BlockingIOError: 235.

 -- Dati: errno.ENOMSG

     No message of desired type

 -- Dati: errno.EIDRM

     Identifier removed

 -- Dati: errno.ECHRNG

     Channel number out of range

 -- Dati: errno.EL2NSYNC

     Level 2 not synchronized

 -- Dati: errno.EL3HLT

     Level 3 halted

 -- Dati: errno.EL3RST

     Level 3 reset

 -- Dati: errno.ELNRNG

     Link number out of range

 -- Dati: errno.EUNATCH

     Protocol driver not attached

 -- Dati: errno.ENOCSI

     No CSI structure available

 -- Dati: errno.EL2HLT

     Level 2 halted

 -- Dati: errno.EBADE

     Invalid exchange

 -- Dati: errno.EBADR

     Invalid request descriptor

 -- Dati: errno.EXFULL

     Exchange full

 -- Dati: errno.ENOANO

     No anode

 -- Dati: errno.EBADRQC

     Invalid request code

 -- Dati: errno.EBADSLT

     Invalid slot

 -- Dati: errno.EDEADLOCK

     File locking deadlock error

 -- Dati: errno.EBFONT

     Bad font file format

 -- Dati: errno.ENOSTR

     Device not a stream

 -- Dati: errno.ENODATA

     No data available

 -- Dati: errno.ETIME

     Timer expired

 -- Dati: errno.ENOSR

     Out of streams resources

 -- Dati: errno.ENONET

     Machine is not on the network

 -- Dati: errno.ENOPKG

     Package not installed

 -- Dati: errno.EREMOTE

     Object is remote

 -- Dati: errno.ENOLINK

     Link has been severed

 -- Dati: errno.EADV

     Advertise error

 -- Dati: errno.ESRMNT

     Srmount error

 -- Dati: errno.ECOMM

     Communication error on send

 -- Dati: errno.EPROTO

     Protocol error

 -- Dati: errno.EMULTIHOP

     Multihop attempted

 -- Dati: errno.EDOTDOT

     RFS specific error

 -- Dati: errno.EBADMSG

     Not a data message

 -- Dati: errno.EOVERFLOW

     Value too large for defined data type

 -- Dati: errno.ENOTUNIQ

     Name not unique on network

 -- Dati: errno.EBADFD

     File descriptor in bad state

 -- Dati: errno.EREMCHG

     Remote address changed

 -- Dati: errno.ELIBACC

     Can not access a needed shared library

 -- Dati: errno.ELIBBAD

     Accessing a corrupted shared library

 -- Dati: errno.ELIBSCN

     .lib section in a.out corrupted

 -- Dati: errno.ELIBMAX

     Attempting to link in too many shared libraries

 -- Dati: errno.ELIBEXEC

     Cannot exec a shared library directly

 -- Dati: errno.EILSEQ

     Illegal byte sequence

 -- Dati: errno.ERESTART

     Interrupted system call should be restarted

 -- Dati: errno.ESTRPIPE

     Streams pipe error

 -- Dati: errno.EUSERS

     Too many users

 -- Dati: errno.ENOTSOCK

     Socket operation on non-socket

 -- Dati: errno.EDESTADDRREQ

     Destination address required

 -- Dati: errno.EMSGSIZE

     Message too long

 -- Dati: errno.EPROTOTYPE

     Protocol wrong type for socket

 -- Dati: errno.ENOPROTOOPT

     Protocol not available

 -- Dati: errno.EPROTONOSUPPORT

     Protocol not supported

 -- Dati: errno.ESOCKTNOSUPPORT

     Socket type not supported

 -- Dati: errno.EOPNOTSUPP

     Operation not supported on transport endpoint

 -- Dati: errno.ENOTSUP

     Operation not supported

     Added in version 3.2.

 -- Dati: errno.EPFNOSUPPORT

     Protocol family not supported

 -- Dati: errno.EAFNOSUPPORT

     Address family not supported by protocol

 -- Dati: errno.EADDRINUSE

     Address already in use

 -- Dati: errno.EADDRNOTAVAIL

     Cannot assign requested address

 -- Dati: errno.ENETDOWN

     Network is down

 -- Dati: errno.ENETUNREACH

     Network is unreachable

 -- Dati: errno.ENETRESET

     Network dropped connection because of reset

 -- Dati: errno.ECONNABORTED

     Software caused connection abort.  This error is mapped to the
     exception *note ConnectionAbortedError: 125f.

 -- Dati: errno.ECONNRESET

     Connection reset by peer.  This error is mapped to the exception
     *note ConnectionResetError: 1261.

 -- Dati: errno.ENOBUFS

     No buffer space available

 -- Dati: errno.EISCONN

     Transport endpoint is already connected

 -- Dati: errno.ENOTCONN

     Transport endpoint is not connected

 -- Dati: errno.ESHUTDOWN

     Cannot send after transport endpoint shutdown.  This error is
     mapped to the exception *note BrokenPipeError: 125e.

 -- Dati: errno.ETOOMANYREFS

     Too many references: cannot splice

 -- Dati: errno.ETIMEDOUT

     Connection timed out.  This error is mapped to the exception *note
     TimeoutError: a38.

 -- Dati: errno.ECONNREFUSED

     Connection refused.  This error is mapped to the exception *note
     ConnectionRefusedError: 1260.

 -- Dati: errno.EHOSTDOWN

     Host is down

 -- Dati: errno.EHOSTUNREACH

     No route to host

 -- Dati: errno.EHWPOISON

     Memory page has hardware error.

     Added in version 3.14.

 -- Dati: errno.EALREADY

     Operation already in progress.  This error is mapped to the
     exception *note BlockingIOError: 235.

 -- Dati: errno.EINPROGRESS

     Operation now in progress.  This error is mapped to the exception
     *note BlockingIOError: 235.

 -- Dati: errno.ESTALE

     Stale NFS file handle

 -- Dati: errno.EUCLEAN

     Structure needs cleaning

 -- Dati: errno.ENOTNAM

     Not a XENIX named type file

 -- Dati: errno.ENAVAIL

     No XENIX semaphores available

 -- Dati: errno.EISNAM

     Is a named type file

 -- Dati: errno.EREMOTEIO

     Remote I/O error

 -- Dati: errno.EDQUOT

     Quota exceeded

 -- Dati: errno.EQFULL

     Interface output queue is full

     Added in version 3.11.

 -- Dati: errno.ENOMEDIUM

     No medium found

 -- Dati: errno.EMEDIUMTYPE

     Wrong medium type

 -- Dati: errno.ENOKEY

     Required key not available

 -- Dati: errno.EKEYEXPIRED

     Key has expired

 -- Dati: errno.EKEYREVOKED

     Key has been revoked

 -- Dati: errno.EKEYREJECTED

     Key was rejected by service

 -- Dati: errno.ERFKILL

     Operation not possible due to RF-kill

 -- Dati: errno.ELOCKUNMAPPED

     Locked lock was unmapped

 -- Dati: errno.ENOTACTIVE

     Facility is not active

 -- Dati: errno.EAUTH

     Authentication error

     Added in version 3.2.

 -- Dati: errno.EBADARCH

     Bad CPU type in executable

     Added in version 3.2.

 -- Dati: errno.EBADEXEC

     Bad executable (or shared library)

     Added in version 3.2.

 -- Dati: errno.EBADMACHO

     Malformed Mach-o file

     Added in version 3.2.

 -- Dati: errno.EDEVERR

     Device error

     Added in version 3.2.

 -- Dati: errno.EFTYPE

     Inappropriate file type or format

     Added in version 3.2.

 -- Dati: errno.ENEEDAUTH

     Need authenticator

     Added in version 3.2.

 -- Dati: errno.ENOATTR

     Attribute not found

     Added in version 3.2.

 -- Dati: errno.ENOPOLICY

     Policy not found

     Added in version 3.2.

 -- Dati: errno.EPROCLIM

     Too many processes

     Added in version 3.2.

 -- Dati: errno.EPROCUNAVAIL

     Bad procedure for program

     Added in version 3.2.

 -- Dati: errno.EPROGMISMATCH

     Program version wrong

     Added in version 3.2.

 -- Dati: errno.EPROGUNAVAIL

     RPC prog.  not avail

     Added in version 3.2.

 -- Dati: errno.EPWROFF

     Device power is off

     Added in version 3.2.

 -- Dati: errno.EBADRPC

     RPC struct is bad

     Added in version 3.2.

 -- Dati: errno.ERPCMISMATCH

     RPC version wrong

     Added in version 3.2.

 -- Dati: errno.ESHLIBVERS

     Shared library version mismatch

     Added in version 3.2.

 -- Dati: errno.ENOTCAPABLE

     Capabilities insufficient.  This error is mapped to the exception
     *note PermissionError: f40.

     *note Availability: 2128.: WASI, FreeBSD

     Added in version 3.11.1.

 -- Dati: errno.ECANCELED

     Operation canceled

     Added in version 3.2.

 -- Dati: errno.EOWNERDEAD

     Owner died

     Added in version 3.2.

 -- Dati: errno.ENOTRECOVERABLE

     State not recoverable

     Added in version 3.2.


File: python.info,  Node: ctypes — A foreign function library for Python,  Prev: errno — Standard errno system symbols,  Up: Generic Operating System Services

5.16.9 ‘ctypes’ — A foreign function library for Python
-------------------------------------------------------

'Source code:' Lib/ctypes(1)

__________________________________________________________________

*note ctypes: 2e. is a foreign function library for Python.  It provides
C compatible data types, and allows calling functions in DLLs or shared
libraries.  It can be used to wrap these libraries in pure Python.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

* Menu:

* ctypes tutorial::
* ctypes reference::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/ctypes


File: python.info,  Node: ctypes tutorial,  Next: ctypes reference,  Up: ctypes — A foreign function library for Python

5.16.9.1 ctypes tutorial
........................

Note: The code samples in this tutorial use *note doctest: 3e. to make
sure that they actually work.  Since some code samples behave
differently under Linux, Windows, or macOS, they contain doctest
directives in comments.

Note: Some code samples reference the ctypes *note c_int: 32b5. type.
On platforms where ‘sizeof(long) == sizeof(int)’ it is an alias to *note
c_long: 32b6.  So, you should not be confused if *note c_long: 32b6. is
printed if you would expect *note c_int: 32b5. — they are actually the
same type.

* Menu:

* Loading dynamic link libraries::
* Accessing functions from loaded dlls::
* Calling functions::
* Fundamental data types::
* Calling functions, continued: Calling functions continued.
* Calling variadic functions::
* Calling functions with your own custom data types::
* Specifying the required argument types (function prototypes): Specifying the required argument types function prototypes.
* Return types::
* Passing pointers (or; passing parameters by reference): Passing pointers or passing parameters by reference.
* Structures and unions::
* Structure/union layout, alignment and byte order: Structure/union layout alignment and byte order.
* Bit fields in structures and unions::
* Arrays::
* Pointers::
* Thread safety without the GIL::
* Type conversions::
* Incomplete Types::
* Callback functions::
* Accessing values exported from dlls::
* Surprises::
* Variable-sized data types::


File: python.info,  Node: Loading dynamic link libraries,  Next: Accessing functions from loaded dlls,  Up: ctypes tutorial

5.16.9.2 Loading dynamic link libraries
.......................................

*note ctypes: 2e. exports the 'cdll', and on Windows 'windll' and
'oledll' objects, for loading dynamic link libraries.

You load libraries by accessing them as attributes of these objects.
'cdll' loads libraries which export functions using the standard ‘cdecl’
calling convention, while 'windll' libraries call functions using the
‘stdcall’ calling convention.  'oledll' also uses the ‘stdcall’ calling
convention, and assumes the functions return a Windows ‘HRESULT’ error
code.  The error code is used to automatically raise an *note OSError:
2c0. exception when the function call fails.

Cambiato nella versione 3.3: Windows errors used to raise *note
WindowsError: 1257, which is now an alias of *note OSError: 2c0.

Here are some examples for Windows.  Note that ‘msvcrt’ is the MS
standard C library containing most standard C functions, and uses the
‘cdecl’ calling convention:

     >>> from ctypes import *
     >>> print(windll.kernel32)
     <WinDLL 'kernel32', handle ... at ...>
     >>> print(cdll.msvcrt)
     <CDLL 'msvcrt', handle ... at ...>
     >>> libc = cdll.msvcrt
     >>>

Windows appends the usual ‘.dll’ file suffix automatically.

     Nota: Accessing the standard C library through ‘cdll.msvcrt’ will
     use an outdated version of the library that may be incompatible
     with the one being used by Python.  Where possible, use native
     Python functionality, or else import and use the ‘msvcrt’ module.

On Linux, it is required to specify the filename 'including' the
extension to load a library, so attribute access can not be used to load
libraries.  Either the *note LoadLibrary(): 32b9. method of the dll
loaders should be used, or you should load the library by creating an
instance of CDLL by calling the constructor:

     >>> cdll.LoadLibrary("libc.so.6")
     <CDLL 'libc.so.6', handle ... at ...>
     >>> libc = CDLL("libc.so.6")
     >>> libc
     <CDLL 'libc.so.6', handle ... at ...>
     >>>


File: python.info,  Node: Accessing functions from loaded dlls,  Next: Calling functions,  Prev: Loading dynamic link libraries,  Up: ctypes tutorial

5.16.9.3 Accessing functions from loaded dlls
.............................................

Functions are accessed as attributes of dll objects:

     >>> libc.printf
     <_FuncPtr object at 0x...>
     >>> print(windll.kernel32.GetModuleHandleA)
     <_FuncPtr object at 0x...>
     >>> print(windll.kernel32.MyOwnFunction)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
       File "ctypes.py", line 239, in __getattr__
         func = _StdcallFuncPtr(name, self)
     AttributeError: function 'MyOwnFunction' not found
     >>>

Note that win32 system dlls like ‘kernel32’ and ‘user32’ often export
ANSI as well as UNICODE versions of a function.  The UNICODE version is
exported with a ‘W’ appended to the name, while the ANSI version is
exported with an ‘A’ appended to the name.  The win32 ‘GetModuleHandle’
function, which returns a 'module handle' for a given module name, has
the following C prototype, and a macro is used to expose one of them as
‘GetModuleHandle’ depending on whether UNICODE is defined or not:

     /* ANSI version */
     HMODULE GetModuleHandleA(LPCSTR lpModuleName);
     /* UNICODE version */
     HMODULE GetModuleHandleW(LPCWSTR lpModuleName);

'windll' does not try to select one of them by magic, you must access
the version you need by specifying ‘GetModuleHandleA’ or
‘GetModuleHandleW’ explicitly, and then call it with bytes or string
objects respectively.

Sometimes, dlls export functions with names which aren’t valid Python
identifiers, like ‘"??2@YAPAXI@Z"’.  In this case you have to use *note
getattr(): dcc. to retrieve the function:

     >>> getattr(cdll.msvcrt, "??2@YAPAXI@Z")
     <_FuncPtr object at 0x...>
     >>>

On Windows, some dlls export functions not by name but by ordinal.
These functions can be accessed by indexing the dll object with the
ordinal number:

     >>> cdll.kernel32[1]
     <_FuncPtr object at 0x...>
     >>> cdll.kernel32[0]
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
       File "ctypes.py", line 310, in __getitem__
         func = _StdcallFuncPtr(name, self)
     AttributeError: function ordinal 0 not found
     >>>


File: python.info,  Node: Calling functions,  Next: Fundamental data types,  Prev: Accessing functions from loaded dlls,  Up: ctypes tutorial

5.16.9.4 Calling functions
..........................

You can call these functions like any other Python callable.  This
example uses the ‘rand()’ function, which takes no arguments and returns
a pseudo-random integer:

     >>> print(libc.rand())
     1804289383

On Windows, you can call the ‘GetModuleHandleA()’ function, which
returns a win32 module handle (passing ‘None’ as single argument to call
it with a ‘NULL’ pointer):

     >>> print(hex(windll.kernel32.GetModuleHandleA(None)))
     0x1d000000
     >>>

*note ValueError: 2ec. is raised when you call an ‘stdcall’ function
with the ‘cdecl’ calling convention, or vice versa:

     >>> cdll.kernel32.GetModuleHandleA(None)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     ValueError: Procedure probably called with not enough arguments (4 bytes missing)
     >>>

     >>> windll.msvcrt.printf(b"spam")
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     ValueError: Procedure probably called with too many arguments (4 bytes in excess)
     >>>

To find out the correct calling convention you have to look into the C
header file or the documentation for the function you want to call.

On Windows, *note ctypes: 2e. uses win32 structured exception handling
to prevent crashes from general protection faults when functions are
called with invalid argument values:

     >>> windll.kernel32.GetModuleHandleA(32)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     OSError: exception: access violation reading 0x00000020
     >>>

There are, however, enough ways to crash Python with *note ctypes: 2e,
so you should be careful anyway.  The *note faulthandler: 5c. module can
be helpful in debugging crashes (e.g.  from segmentation faults produced
by erroneous C library calls).

‘None’, integers, bytes objects and (unicode) strings are the only
native Python objects that can directly be used as parameters in these
function calls.  ‘None’ is passed as a C ‘NULL’ pointer, bytes objects
and strings are passed as pointer to the memory block that contains
their data (char* or wchar_t*).  Python integers are passed as the
platform’s default C int type, their value is masked to fit into the C
type.

Before we move on calling functions with other parameter types, we have
to learn more about *note ctypes: 2e. data types.


File: python.info,  Node: Fundamental data types,  Next: Calling functions continued,  Prev: Calling functions,  Up: ctypes tutorial

5.16.9.5 Fundamental data types
...............................

*note ctypes: 2e. defines a number of primitive C compatible data types:

ctypes type                C type                                         Python type
                                                                          
-----------------------------------------------------------------------------------------------------------
                                                                          
*note c_bool: 32c0.        _Bool                                          bool (1)
                                                                          
                                                                          
*note c_char: 32c1.        char                                           1-character bytes object
                                                                          
                                                                          
*note c_wchar: 32c2.       ‘wchar_t’                                      1-character string
                                                                          
                                                                          
*note c_byte: 1ac8.        char                                           int
                                                                          
                                                                          
*note c_ubyte: 1ac9.       unsigned char                                  int
                                                                          
                                                                          
*note c_short: 32c3.       short                                          int
                                                                          
                                                                          
*note c_ushort: 32c4.      unsigned short                                 int
                                                                          
                                                                          
*note c_int: 32b5.         int                                            int
                                                                          
                                                                          
*note c_int8: 32c5.        ‘int8_t’                                       int
                                                                          
                                                                          
*note c_int16: 32c6.       ‘int16_t’                                      int
                                                                          
                                                                          
*note c_int32: 32c7.       ‘int32_t’                                      int
                                                                          
                                                                          
*note c_int64: 32c8.       ‘int64_t’                                      int
                                                                          
                                                                          
*note c_uint: 32c9.        unsigned int                                   int
                                                                          
                                                                          
*note c_uint8: 32ca.       ‘uint8_t’                                      int
                                                                          
                                                                          
*note c_uint16: 32cb.      ‘uint16_t’                                     int
                                                                          
                                                                          
*note c_uint32: 32cc.      ‘uint32_t’                                     int
                                                                          
                                                                          
*note c_uint64: 32cd.      ‘uint64_t’                                     int
                                                                          
                                                                          
*note c_long: 32b6.        long                                           int
                                                                          
                                                                          
*note c_ulong: 32ce.       unsigned long                                  int
                                                                          
                                                                          
*note c_longlong: 32cf.    __int64 or long long                           int
                                                                          
                                                                          
*note c_ulonglong: 32d0.   unsigned __int64 or unsigned long long         int
                                                                          
                                                                          
*note c_size_t: 32d1.      ‘size_t’                                       int
                                                                          
                                                                          
*note c_ssize_t: 1444.     ‘ssize_t’ or *note Py_ssize_t: c57.            int
                                                                          
                                                                          
*note c_time_t: 1b4b.      ‘time_t’                                       int
                                                                          
                                                                          
*note c_float: 32d2.       float                                          float
                                                                          
                                                                          
*note c_double: 1ca0.      double                                         float
                                                                          
                                                                          
*note c_longdouble: 1ca1.  long double                                    float
                                                                          
                                                                          
*note c_char_p: 1a3f.      char* (NUL terminated)                         bytes object or ‘None’
                                                                          
                                                                          
*note c_wchar_p: 1a40.     wchar_t* (NUL terminated)                      string or ‘None’
                                                                          
                                                                          
*note c_void_p: 1a41.      void*                                          int or ‘None’
                                                                          

  1. The constructor accepts any object with a truth value.

Additionally, if IEC 60559 compatible complex arithmetic (Annex G) is
supported in both C and ‘libffi’, the following complex types are
available:

ctypes type                            C type                                Python type
                                                                             
---------------------------------------------------------------------------------------------------
                                                                             
*note c_float_complex: 1ed.            float complex                         complex
                                                                             
                                                                             
*note c_double_complex: 1ee.           double complex                        complex
                                                                             
                                                                             
*note c_longdouble_complex: 1ef.       long double complex                   complex
                                                                             

All these types can be created by calling them with an optional
initializer of the correct type and value:

     >>> c_int()
     c_long(0)
     >>> c_wchar_p("Hello, World")
     c_wchar_p(140018365411392)
     >>> c_ushort(-3)
     c_ushort(65533)
     >>>

Since these types are mutable, their value can also be changed
afterwards:

     >>> i = c_int(42)
     >>> print(i)
     c_long(42)
     >>> print(i.value)
     42
     >>> i.value = -99
     >>> print(i.value)
     -99
     >>>

Assigning a new value to instances of the pointer types *note c_char_p:
1a3f, *note c_wchar_p: 1a40, and *note c_void_p: 1a41. changes the
'memory location' they point to, 'not the contents' of the memory block
(of course not, because Python string objects are immutable):

     >>> s = "Hello, World"
     >>> c_s = c_wchar_p(s)
     >>> print(c_s)
     c_wchar_p(139966785747344)
     >>> print(c_s.value)
     Hello World
     >>> c_s.value = "Hi, there"
     >>> print(c_s)              # the memory location has changed
     c_wchar_p(139966783348904)
     >>> print(c_s.value)
     Hi, there
     >>> print(s)                # first object is unchanged
     Hello, World
     >>>

You should be careful, however, not to pass them to functions expecting
pointers to mutable memory.  If you need mutable memory blocks, ctypes
has a *note create_string_buffer(): 32d3. function which creates these
in various ways.  The current memory block contents can be accessed (or
changed) with the ‘raw’ property; if you want to access it as NUL
terminated string, use the ‘value’ property:

     >>> from ctypes import *
     >>> p = create_string_buffer(3)            # create a 3 byte buffer, initialized to NUL bytes
     >>> print(sizeof(p), repr(p.raw))
     3 b'\x00\x00\x00'
     >>> p = create_string_buffer(b"Hello")     # create a buffer containing a NUL terminated string
     >>> print(sizeof(p), repr(p.raw))
     6 b'Hello\x00'
     >>> print(repr(p.value))
     b'Hello'
     >>> p = create_string_buffer(b"Hello", 10) # create a 10 byte buffer
     >>> print(sizeof(p), repr(p.raw))
     10 b'Hello\x00\x00\x00\x00\x00'
     >>> p.value = b"Hi"
     >>> print(sizeof(p), repr(p.raw))
     10 b'Hi\x00lo\x00\x00\x00\x00\x00'
     >>>

The *note create_string_buffer(): 32d3. function replaces the old
‘c_buffer()’ function (which is still available as an alias).  To create
a mutable memory block containing unicode characters of the C type
‘wchar_t’, use the *note create_unicode_buffer(): 1d9c. function.


File: python.info,  Node: Calling functions continued,  Next: Calling variadic functions,  Prev: Fundamental data types,  Up: ctypes tutorial

5.16.9.6 Calling functions, continued
.....................................

Note that printf prints to the real standard output channel, 'not' to
*note sys.stdout: ccf, so these examples will only work at the console
prompt, not from within 'IDLE' or 'PythonWin':

     >>> printf = libc.printf
     >>> printf(b"Hello, %s\n", b"World!")
     Hello, World!
     14
     >>> printf(b"Hello, %S\n", "World!")
     Hello, World!
     14
     >>> printf(b"%d bottles of beer\n", 42)
     42 bottles of beer
     19
     >>> printf(b"%f bottles of beer\n", 42.5)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     ctypes.ArgumentError: argument 2: TypeError: Don't know how to convert parameter 2
     >>>

As has been mentioned before, all Python types except integers, strings,
and bytes objects have to be wrapped in their corresponding *note
ctypes: 2e. type, so that they can be converted to the required C data
type:

     >>> printf(b"An int %d, a double %f\n", 1234, c_double(3.14))
     An int 1234, a double 3.140000
     31
     >>>


File: python.info,  Node: Calling variadic functions,  Next: Calling functions with your own custom data types,  Prev: Calling functions continued,  Up: ctypes tutorial

5.16.9.7 Calling variadic functions
...................................

On a lot of platforms calling variadic functions through ctypes is
exactly the same as calling functions with a fixed number of parameters.
On some platforms, and in particular ARM64 for Apple Platforms, the
calling convention for variadic functions is different than that for
regular functions.

On those platforms it is required to specify the *note argtypes: 17a9.
attribute for the regular, non-variadic, function arguments:

     libc.printf.argtypes = [ctypes.c_char_p]

Because specifying the attribute does not inhibit portability it is
advised to always specify *note argtypes: 17a9. for all variadic
functions.


File: python.info,  Node: Calling functions with your own custom data types,  Next: Specifying the required argument types function prototypes,  Prev: Calling variadic functions,  Up: ctypes tutorial

5.16.9.8 Calling functions with your own custom data types
..........................................................

You can also customize *note ctypes: 2e. argument conversion to allow
instances of your own classes be used as function arguments.  *note
ctypes: 2e. looks for an ‘_as_parameter_’ attribute and uses this as the
function argument.  The attribute must be an integer, string, bytes, a
*note ctypes: 2e. instance, or an object with an ‘_as_parameter_’
attribute:

     >>> class Bottles:
     ...     def __init__(self, number):
     ...         self._as_parameter_ = number
     ...
     >>> bottles = Bottles(42)
     >>> printf(b"%d bottles of beer\n", bottles)
     42 bottles of beer
     19
     >>>

If you don’t want to store the instance’s data in the ‘_as_parameter_’
instance variable, you could define a *note property: 4b4. which makes
the attribute available on request.


File: python.info,  Node: Specifying the required argument types function prototypes,  Next: Return types,  Prev: Calling functions with your own custom data types,  Up: ctypes tutorial

5.16.9.9 Specifying the required argument types (function prototypes)
.....................................................................

It is possible to specify the required argument types of functions
exported from DLLs by setting the *note argtypes: 17a9. attribute.

*note argtypes: 17a9. must be a sequence of C data types (the ‘printf()’
function is probably not a good example here, because it takes a
variable number and different types of parameters depending on the
format string, on the other hand this is quite handy to experiment with
this feature):

     >>> printf.argtypes = [c_char_p, c_char_p, c_int, c_double]
     >>> printf(b"String '%s', Int %d, Double %f\n", b"Hi", 10, 2.2)
     String 'Hi', Int 10, Double 2.200000
     37
     >>>

Specifying a format protects against incompatible argument types (just
as a prototype for a C function), and tries to convert the arguments to
valid types:

     >>> printf(b"%d %d %d", 1, 2, 3)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     ctypes.ArgumentError: argument 2: TypeError: 'int' object cannot be interpreted as ctypes.c_char_p
     >>> printf(b"%s %d %f\n", b"X", 2, 3)
     X 2 3.000000
     13
     >>>

If you have defined your own classes which you pass to function calls,
you have to implement a *note from_param(): 32dc. class method for them
to be able to use them in the *note argtypes: 17a9. sequence.  The *note
from_param(): 32dc. class method receives the Python object passed to
the function call, it should do a typecheck or whatever is needed to
make sure this object is acceptable, and then return the object itself,
its ‘_as_parameter_’ attribute, or whatever you want to pass as the C
function argument in this case.  Again, the result should be an integer,
string, bytes, a *note ctypes: 2e. instance, or an object with an
‘_as_parameter_’ attribute.


File: python.info,  Node: Return types,  Next: Passing pointers or passing parameters by reference,  Prev: Specifying the required argument types function prototypes,  Up: ctypes tutorial

5.16.9.10 Return types
......................

By default functions are assumed to return the C int type.  Other return
types can be specified by setting the *note restype: 32df. attribute of
the function object.

The C prototype of ‘time()’ is ‘time_t time(time_t *)’.  Because
‘time_t’ might be of a different type than the default return type int,
you should specify the ‘restype’ attribute:

     >>> libc.time.restype = c_time_t

The argument types can be specified using *note argtypes: 17a9.:

     >>> libc.time.argtypes = (POINTER(c_time_t),)

To call the function with a ‘NULL’ pointer as first argument, use
‘None’:

     >>> print(libc.time(None))
     1150640792

Here is a more advanced example, it uses the ‘strchr()’ function, which
expects a string pointer and a char, and returns a pointer to a string:

     >>> strchr = libc.strchr
     >>> strchr(b"abcdef", ord("d"))
     8059983
     >>> strchr.restype = c_char_p    # c_char_p is a pointer to a string
     >>> strchr(b"abcdef", ord("d"))
     b'def'
     >>> print(strchr(b"abcdef", ord("x")))
     None
     >>>

If you want to avoid the *note ord("x"): 2323. calls above, you can set
the *note argtypes: 17a9. attribute, and the second argument will be
converted from a single character Python bytes object into a C char:

     >>> strchr.restype = c_char_p
     >>> strchr.argtypes = [c_char_p, c_char]
     >>> strchr(b"abcdef", b"d")
     b'def'
     >>> strchr(b"abcdef", b"def")
     Traceback (most recent call last):
     ctypes.ArgumentError: argument 2: TypeError: one character bytes, bytearray or integer expected
     >>> print(strchr(b"abcdef", b"x"))
     None
     >>> strchr(b"abcdef", b"d")
     b'def'
     >>>

You can also use a callable Python object (a function or a class for
example) as the *note restype: 32df. attribute, if the foreign function
returns an integer.  The callable will be called with the 'integer' the
C function returns, and the result of this call will be used as the
result of your function call.  This is useful to check for error return
values and automatically raise an exception:

     >>> GetModuleHandle = windll.kernel32.GetModuleHandleA
     >>> def ValidHandle(value):
     ...     if value == 0:
     ...         raise WinError()
     ...     return value
     ...
     >>>
     >>> GetModuleHandle.restype = ValidHandle
     >>> GetModuleHandle(None)
     486539264
     >>> GetModuleHandle("something silly")
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
       File "<stdin>", line 3, in ValidHandle
     OSError: [Errno 126] The specified module could not be found.
     >>>

‘WinError’ is a function which will call Windows ‘FormatMessage()’ api
to get the string representation of an error code, and 'returns' an
exception.  ‘WinError’ takes an optional error code parameter, if no one
is used, it calls *note GetLastError(): 32e0. to retrieve it.

Please note that a much more powerful error checking mechanism is
available through the *note errcheck: 32e1. attribute; see the reference
manual for details.


File: python.info,  Node: Passing pointers or passing parameters by reference,  Next: Structures and unions,  Prev: Return types,  Up: ctypes tutorial

5.16.9.11 Passing pointers (or: passing parameters by reference)
................................................................

Sometimes a C api function expects a 'pointer' to a data type as
parameter, probably to write into the corresponding location, or if the
data is too large to be passed by value.  This is also known as 'passing
parameters by reference'.

*note ctypes: 2e. exports the *note byref(): 32e4. function which is
used to pass parameters by reference.  The same effect can be achieved
with the *note pointer(): 1a3e. function, although *note pointer():
1a3e. does a lot more work since it constructs a real pointer object, so
it is faster to use *note byref(): 32e4. if you don’t need the pointer
object in Python itself:

     >>> i = c_int()
     >>> f = c_float()
     >>> s = create_string_buffer(b'\000' * 32)
     >>> print(i.value, f.value, repr(s.value))
     0 0.0 b''
     >>> libc.sscanf(b"1 3.14 Hello", b"%d %f %s",
     ...             byref(i), byref(f), s)
     3
     >>> print(i.value, f.value, repr(s.value))
     1 3.1400001049 b'Hello'
     >>>


File: python.info,  Node: Structures and unions,  Next: Structure/union layout alignment and byte order,  Prev: Passing pointers or passing parameters by reference,  Up: ctypes tutorial

5.16.9.12 Structures and unions
...............................

Structures and unions must derive from the *note Structure: 1e5. and
*note Union: 1e6. base classes which are defined in the *note ctypes:
2e. module.  Each subclass must define a *note _fields_: 191e.
attribute.  ‘_fields_’ must be a list of '2-tuples', containing a 'field
name' and a 'field type'.

The field type must be a *note ctypes: 2e. type like *note c_int: 32b5,
or any other derived *note ctypes: 2e. type: structure, union, array,
pointer.

Here is a simple example of a POINT structure, which contains two
integers named 'x' and 'y', and also shows how to initialize a structure
in the constructor:

     >>> from ctypes import *
     >>> class POINT(Structure):
     ...     _fields_ = [("x", c_int),
     ...                 ("y", c_int)]
     ...
     >>> point = POINT(10, 20)
     >>> print(point.x, point.y)
     10 20
     >>> point = POINT(y=5)
     >>> print(point.x, point.y)
     0 5
     >>> POINT(1, 2, 3)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: too many initializers
     >>>

You can, however, build much more complicated structures.  A structure
can itself contain other structures by using a structure as a field
type.

Here is a RECT structure which contains two POINTs named 'upperleft' and
'lowerright':

     >>> class RECT(Structure):
     ...     _fields_ = [("upperleft", POINT),
     ...                 ("lowerright", POINT)]
     ...
     >>> rc = RECT(point)
     >>> print(rc.upperleft.x, rc.upperleft.y)
     0 5
     >>> print(rc.lowerright.x, rc.lowerright.y)
     0 0
     >>>

Nested structures can also be initialized in the constructor in several
ways:

     >>> r = RECT(POINT(1, 2), POINT(3, 4))
     >>> r = RECT((1, 2), (3, 4))

Field *note descriptor: 1869.s can be retrieved from the 'class', they
are useful for debugging because they can provide useful information.
See *note CField: 1e8.:

     >>> POINT.x
     <ctypes.CField 'x' type=c_int, ofs=0, size=4>
     >>> POINT.y
     <ctypes.CField 'y' type=c_int, ofs=4, size=4>
     >>>
     Avvertimento: *note ctypes: 2e. does not support passing unions or
     structures with bit-fields to functions by value.  While this may
     work on 32-bit x86, it’s not guaranteed by the library to work in
     the general case.  Unions and structures with bit-fields should
     always be passed to functions by pointer.


File: python.info,  Node: Structure/union layout alignment and byte order,  Next: Bit fields in structures and unions,  Prev: Structures and unions,  Up: ctypes tutorial

5.16.9.13 Structure/union layout, alignment and byte order
..........................................................

By default, Structure and Union fields are laid out in the same way the
C compiler does it.  It is possible to override this behavior entirely
by specifying a *note _layout_: 1e7. class attribute in the subclass
definition; see the attribute documentation for details.

It is possible to specify the maximum alignment for the fields and/or
for the structure itself by setting the class attributes *note _pack_:
317. and/or *note _align_: 4e9, respectively.  See the attribute
documentation for details.

*note ctypes: 2e. uses the native byte order for Structures and Unions.
To build structures with non-native byte order, you can use one of the
*note BigEndianStructure: 32e9, *note LittleEndianStructure: 32ea, *note
BigEndianUnion: 1b9f, and *note LittleEndianUnion: 1ba0. base classes.
These classes cannot contain pointer fields.


File: python.info,  Node: Bit fields in structures and unions,  Next: Arrays,  Prev: Structure/union layout alignment and byte order,  Up: ctypes tutorial

5.16.9.14 Bit fields in structures and unions
.............................................

It is possible to create structures and unions containing bit fields.
Bit fields are only possible for integer fields, the bit width is
specified as the third item in the *note _fields_: 191e. tuples:

     >>> class Int(Structure):
     ...     _fields_ = [("first_16", c_int, 16),
     ...                 ("second_16", c_int, 16)]
     ...
     >>> print(Int.first_16)
     <ctypes.CField 'first_16' type=c_int, ofs=0, bit_size=16, bit_offset=0>
     >>> print(Int.second_16)
     <ctypes.CField 'second_16' type=c_int, ofs=0, bit_size=16, bit_offset=16>

It is important to note that bit field allocation and layout in memory
are not defined as a C standard; their implementation is
compiler-specific.  By default, Python will attempt to match the
behavior of a «native» compiler for the current platform.  See the *note
_layout_: 1e7. attribute for details on the default behavior and how to
change it.


File: python.info,  Node: Arrays,  Next: Pointers,  Prev: Bit fields in structures and unions,  Up: ctypes tutorial

5.16.9.15 Arrays
................

Arrays are sequences, containing a fixed number of instances of the same
type.

The recommended way to create array types is by multiplying a data type
with a positive integer:

     TenPointsArrayType = POINT * 10

Here is an example of a somewhat artificial data type, a structure
containing 4 POINTs among other stuff:

     >>> from ctypes import *
     >>> class POINT(Structure):
     ...     _fields_ = ("x", c_int), ("y", c_int)
     ...
     >>> class MyStruct(Structure):
     ...     _fields_ = [("a", c_int),
     ...                 ("b", c_float),
     ...                 ("point_array", POINT * 4)]
     >>>
     >>> print(len(MyStruct().point_array))
     4
     >>>

Instances are created in the usual way, by calling the class:

     arr = TenPointsArrayType()
     for pt in arr:
         print(pt.x, pt.y)

The above code print a series of ‘0 0’ lines, because the array contents
is initialized to zeros.

Initializers of the correct type can also be specified:

     >>> from ctypes import *
     >>> TenIntegers = c_int * 10
     >>> ii = TenIntegers(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
     >>> print(ii)
     <c_long_Array_10 object at 0x...>
     >>> for i in ii: print(i, end=" ")
     ...
     1 2 3 4 5 6 7 8 9 10
     >>>


File: python.info,  Node: Pointers,  Next: Thread safety without the GIL,  Prev: Arrays,  Up: ctypes tutorial

5.16.9.16 Pointers
..................

Pointer instances are created by calling the *note pointer(): 1a3e.
function on a *note ctypes: 2e. type:

     >>> from ctypes import *
     >>> i = c_int(42)
     >>> pi = pointer(i)
     >>>

Pointer instances have a *note contents: 32f0. attribute which returns
the object to which the pointer points, the ‘i’ object above:

     >>> pi.contents
     c_long(42)
     >>>

Note that *note ctypes: 2e. does not have OOR (original object return),
it constructs a new, equivalent object each time you retrieve an
attribute:

     >>> pi.contents is i
     False
     >>> pi.contents is pi.contents
     False
     >>>

Assigning another *note c_int: 32b5. instance to the pointer’s contents
attribute would cause the pointer to point to the memory location where
this is stored:

     >>> i = c_int(99)
     >>> pi.contents = i
     >>> pi.contents
     c_long(99)
     >>>

Pointer instances can also be indexed with integers:

     >>> pi[0]
     99
     >>>

Assigning to an integer index changes the pointed to value:

     >>> print(i)
     c_long(99)
     >>> pi[0] = 22
     >>> print(i)
     c_long(22)
     >>>

It is also possible to use indexes different from 0, but you must know
what you’re doing, just as in C: You can access or change arbitrary
memory locations.  Generally you only use this feature if you receive a
pointer from a C function, and you 'know' that the pointer actually
points to an array instead of a single item.

Behind the scenes, the *note pointer(): 1a3e. function does more than
simply create pointer instances, it has to create pointer 'types' first.
This is done with the *note POINTER(): 1f1. function, which accepts any
*note ctypes: 2e. type, and returns a new type:

     >>> PI = POINTER(c_int)
     >>> PI
     <class 'ctypes.LP_c_long'>
     >>> PI(42)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: expected c_long instead of int
     >>> PI(c_int(42))
     <ctypes.LP_c_long object at 0x...>
     >>>

Calling the pointer type without an argument creates a ‘NULL’ pointer.
‘NULL’ pointers have a ‘False’ boolean value:

     >>> null_ptr = POINTER(c_int)()
     >>> print(bool(null_ptr))
     False
     >>>

*note ctypes: 2e. checks for ‘NULL’ when dereferencing pointers (but
dereferencing invalid non-‘NULL’ pointers would crash Python):

     >>> null_ptr[0]
     Traceback (most recent call last):
         ....
     ValueError: NULL pointer access
     >>>

     >>> null_ptr[0] = 1234
     Traceback (most recent call last):
         ....
     ValueError: NULL pointer access
     >>>


File: python.info,  Node: Thread safety without the GIL,  Next: Type conversions,  Prev: Pointers,  Up: ctypes tutorial

5.16.9.17 Thread safety without the GIL
.......................................

From Python 3.13 onward, the *note GIL: 164. can be disabled on *note
free threaded: 1f4. builds.  In ctypes, reads and writes to a single
object concurrently is safe, but not across multiple objects:

          >>> number = c_int(42)
          >>> pointer_a = pointer(number)
          >>> pointer_b = pointer(number)

In the above, it’s only safe for one object to read and write to the
address at once if the GIL is disabled.  So, ‘pointer_a’ can be shared
and written to across multiple threads, but only if ‘pointer_b’ is not
also attempting to do the same.  If this is an issue, consider using a
*note threading.Lock: 19dc. to synchronize access to memory:

          >>> import threading
          >>> lock = threading.Lock()
          >>> # Thread 1
          >>> with lock:
          ...    pointer_a.contents = 24
          >>> # Thread 2
          >>> with lock:
          ...    pointer_b.contents = 42


File: python.info,  Node: Type conversions,  Next: Incomplete Types,  Prev: Thread safety without the GIL,  Up: ctypes tutorial

5.16.9.18 Type conversions
..........................

Usually, ctypes does strict type checking.  This means, if you have
‘POINTER(c_int)’ in the *note argtypes: 17a9. list of a function or as
the type of a member field in a structure definition, only instances of
exactly the same type are accepted.  There are some exceptions to this
rule, where ctypes accepts other objects.  For example, you can pass
compatible array instances instead of pointer types.  So, for
‘POINTER(c_int)’, ctypes accepts an array of c_int:

     >>> class Bar(Structure):
     ...     _fields_ = [("count", c_int), ("values", POINTER(c_int))]
     ...
     >>> bar = Bar()
     >>> bar.values = (c_int * 3)(1, 2, 3)
     >>> bar.count = 3
     >>> for i in range(bar.count):
     ...     print(bar.values[i])
     ...
     1
     2
     3
     >>>

In addition, if a function argument is explicitly declared to be a
pointer type (such as ‘POINTER(c_int)’) in *note argtypes: 17a9, an
object of the pointed type (‘c_int’ in this case) can be passed to the
function.  ctypes will apply the required *note byref(): 32e4.
conversion in this case automatically.

To set a POINTER type field to ‘NULL’, you can assign ‘None’:

     >>> bar.values = None
     >>>

Sometimes you have instances of incompatible types.  In C, you can cast
one type into another type.  *note ctypes: 2e. provides a *note cast():
32f5. function which can be used in the same way.  The ‘Bar’ structure
defined above accepts ‘POINTER(c_int)’ pointers or *note c_int: 32b5.
arrays for its ‘values’ field, but not instances of other types:

     >>> bar.values = (c_byte * 4)()
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: incompatible types, c_byte_Array_4 instance instead of LP_c_long instance
     >>>

For these cases, the *note cast(): 32f5. function is handy.

The *note cast(): 32f5. function can be used to cast a ctypes instance
into a pointer to a different ctypes data type.  *note cast(): 32f5.
takes two parameters, a ctypes object that is or can be converted to a
pointer of some kind, and a ctypes pointer type.  It returns an instance
of the second argument, which references the same memory block as the
first argument:

     >>> a = (c_byte * 4)()
     >>> cast(a, POINTER(c_int))
     <ctypes.LP_c_long object at ...>
     >>>

So, *note cast(): 32f5. can be used to assign to the ‘values’ field of
‘Bar’ the structure:

     >>> bar = Bar()
     >>> bar.values = cast((c_byte * 4)(), POINTER(c_int))
     >>> print(bar.values[0])
     0
     >>>


File: python.info,  Node: Incomplete Types,  Next: Callback functions,  Prev: Type conversions,  Up: ctypes tutorial

5.16.9.19 Incomplete Types
..........................

'Incomplete Types' are structures, unions or arrays whose members are
not yet specified.  In C, they are specified by forward declarations,
which are defined later:

     struct cell; /* forward declaration */

     struct cell {
         char *name;
         struct cell *next;
     };

The straightforward translation into ctypes code would be this, but it
does not work:

     >>> class cell(Structure):
     ...     _fields_ = [("name", c_char_p),
     ...                 ("next", POINTER(cell))]
     ...
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
       File "<stdin>", line 2, in cell
     NameError: name 'cell' is not defined
     >>>

because the new ‘class cell’ is not available in the class statement
itself.  In *note ctypes: 2e, we can define the ‘cell’ class and set the
*note _fields_: 191e. attribute later, after the class statement:

     >>> from ctypes import *
     >>> class cell(Structure):
     ...     pass
     ...
     >>> cell._fields_ = [("name", c_char_p),
     ...                  ("next", POINTER(cell))]
     >>>

Let’s try it.  We create two instances of ‘cell’, and let them point to
each other, and finally follow the pointer chain a few times:

     >>> c1 = cell()
     >>> c1.name = b"foo"
     >>> c2 = cell()
     >>> c2.name = b"bar"
     >>> c1.next = pointer(c2)
     >>> c2.next = pointer(c1)
     >>> p = c1
     >>> for i in range(8):
     ...     print(p.name, end=" ")
     ...     p = p.next[0]
     ...
     foo bar foo bar foo bar foo bar
     >>>


File: python.info,  Node: Callback functions,  Next: Accessing values exported from dlls,  Prev: Incomplete Types,  Up: ctypes tutorial

5.16.9.20 Callback functions
............................

*note ctypes: 2e. allows creating C callable function pointers from
Python callables.  These are sometimes called 'callback functions'.

First, you must create a class for the callback function.  The class
knows the calling convention, the return type, and the number and types
of arguments this function will receive.

The *note CFUNCTYPE(): 32f9. factory function creates types for callback
functions using the ‘cdecl’ calling convention.  On Windows, the *note
WINFUNCTYPE(): 32fa. factory function creates types for callback
functions using the ‘stdcall’ calling convention.

Both of these factory functions are called with the result type as first
argument, and the callback functions expected argument types as the
remaining arguments.

I will present an example here which uses the standard C library’s
‘qsort()’ function, that is used to sort items with the help of a
callback function.  ‘qsort()’ will be used to sort an array of integers:

     >>> IntArray5 = c_int * 5
     >>> ia = IntArray5(5, 1, 7, 33, 99)
     >>> qsort = libc.qsort
     >>> qsort.restype = None
     >>>

‘qsort()’ must be called with a pointer to the data to sort, the number
of items in the data array, the size of one item, and a pointer to the
comparison function, the callback.  The callback will then be called
with two pointers to items, and it must return a negative integer if the
first item is smaller than the second, a zero if they are equal, and a
positive integer otherwise.

So our callback function receives pointers to integers, and must return
an integer.  First we create the ‘type’ for the callback function:

     >>> CMPFUNC = CFUNCTYPE(c_int, POINTER(c_int), POINTER(c_int))
     >>>

To get started, here is a simple callback that shows the values it gets
passed:

     >>> def py_cmp_func(a, b):
     ...     print("py_cmp_func", a[0], b[0])
     ...     return 0
     ...
     >>> cmp_func = CMPFUNC(py_cmp_func)
     >>>

The result:

     >>> qsort(ia, len(ia), sizeof(c_int), cmp_func)
     py_cmp_func 5 1
     py_cmp_func 33 99
     py_cmp_func 7 33
     py_cmp_func 5 7
     py_cmp_func 1 7
     >>>

Now we can actually compare the two items and return a useful result:

     >>> def py_cmp_func(a, b):
     ...     print("py_cmp_func", a[0], b[0])
     ...     return a[0] - b[0]
     ...
     >>>
     >>> qsort(ia, len(ia), sizeof(c_int), CMPFUNC(py_cmp_func))
     py_cmp_func 5 1
     py_cmp_func 33 99
     py_cmp_func 7 33
     py_cmp_func 1 7
     py_cmp_func 5 7
     >>>

As we can easily check, our array is sorted now:

     >>> for i in ia: print(i, end=" ")
     ...
     1 5 7 33 99
     >>>

The function factories can be used as decorator factories, so we may as
well write:

     >>> @CFUNCTYPE(c_int, POINTER(c_int), POINTER(c_int))
     ... def py_cmp_func(a, b):
     ...     print("py_cmp_func", a[0], b[0])
     ...     return a[0] - b[0]
     ...
     >>> qsort(ia, len(ia), sizeof(c_int), py_cmp_func)
     py_cmp_func 5 1
     py_cmp_func 33 99
     py_cmp_func 7 33
     py_cmp_func 1 7
     py_cmp_func 5 7
     >>>

     Nota: Make sure you keep references to *note CFUNCTYPE(): 32f9.
     objects as long as they are used from C code.  *note ctypes: 2e.
     doesn’t, and if you don’t, they may be garbage collected, crashing
     your program when a callback is made.

     Also, note that if the callback function is called in a thread
     created outside of Python’s control (e.g.  by the foreign code that
     calls the callback), ctypes creates a new dummy Python thread on
     every invocation.  This behavior is correct for most purposes, but
     it means that values stored with *note threading.local: 1847. will
     'not' survive across different callbacks, even when those calls are
     made from the same C thread.


File: python.info,  Node: Accessing values exported from dlls,  Next: Surprises,  Prev: Callback functions,  Up: ctypes tutorial

5.16.9.21 Accessing values exported from dlls
.............................................

Some shared libraries not only export functions, they also export
variables.  An example in the Python library itself is the *note
Py_Version: 381, Python runtime version number encoded in a single
constant integer.

*note ctypes: 2e. can access values like this with the *note in_dll():
32fd. class methods of the type.  'pythonapi' is a predefined symbol
giving access to the Python C api:

     >>> version = ctypes.c_int.in_dll(ctypes.pythonapi, "Py_Version")
     >>> print(hex(version.value))
     0x30c00a0

An extended example which also demonstrates the use of pointers accesses
the *note PyImport_FrozenModules: 32fe. pointer exported by Python.

Quoting the docs for that value:

     This pointer is initialized to point to an array of *note _frozen:
     97a. records, terminated by one whose members are all ‘NULL’ or
     zero.  When a frozen module is imported, it is searched in this
     table.  Third-party code could play tricks with this to provide a
     dynamically created collection of frozen modules.

So manipulating this pointer could even prove useful.  To restrict the
example size, we show only how this table can be read with *note ctypes:
2e.:

     >>> from ctypes import *
     >>>
     >>> class struct_frozen(Structure):
     ...     _fields_ = [("name", c_char_p),
     ...                 ("code", POINTER(c_ubyte)),
     ...                 ("size", c_int),
     ...                 ("get_code", POINTER(c_ubyte)),  # Function pointer
     ...                ]
     ...
     >>>

We have defined the *note _frozen: 97a. data type, so we can get the
pointer to the table:

     >>> FrozenTable = POINTER(struct_frozen)
     >>> table = FrozenTable.in_dll(pythonapi, "_PyImport_FrozenBootstrap")
     >>>

Since ‘table’ is a ‘pointer’ to the array of ‘struct_frozen’ records, we
can iterate over it, but we just have to make sure that our loop
terminates, because pointers have no size.  Sooner or later it would
probably crash with an access violation or whatever, so it’s better to
break out of the loop when we hit the ‘NULL’ entry:

     >>> for item in table:
     ...     if item.name is None:
     ...         break
     ...     print(item.name.decode("ascii"), item.size)
     ...
     _frozen_importlib 31764
     _frozen_importlib_external 41499
     zipimport 12345
     >>>

The fact that standard Python has a frozen module and a frozen package
(indicated by the negative ‘size’ member) is not well known, it is only
used for testing.  Try it out with ‘import __hello__’ for example.


File: python.info,  Node: Surprises,  Next: Variable-sized data types,  Prev: Accessing values exported from dlls,  Up: ctypes tutorial

5.16.9.22 Surprises
...................

There are some edges in *note ctypes: 2e. where you might expect
something other than what actually happens.

Consider the following example:

     >>> from ctypes import *
     >>> class POINT(Structure):
     ...     _fields_ = ("x", c_int), ("y", c_int)
     ...
     >>> class RECT(Structure):
     ...     _fields_ = ("a", POINT), ("b", POINT)
     ...
     >>> p1 = POINT(1, 2)
     >>> p2 = POINT(3, 4)
     >>> rc = RECT(p1, p2)
     >>> print(rc.a.x, rc.a.y, rc.b.x, rc.b.y)
     1 2 3 4
     >>> # now swap the two points
     >>> rc.a, rc.b = rc.b, rc.a
     >>> print(rc.a.x, rc.a.y, rc.b.x, rc.b.y)
     3 4 3 4
     >>>

Hm.  We certainly expected the last statement to print ‘3 4 1 2’.  What
happened?  Here are the steps of the ‘rc.a, rc.b = rc.b, rc.a’ line
above:

     >>> temp0, temp1 = rc.b, rc.a
     >>> rc.a = temp0
     >>> rc.b = temp1
     >>>

Note that ‘temp0’ and ‘temp1’ are objects still using the internal
buffer of the ‘rc’ object above.  So executing ‘rc.a = temp0’ copies the
buffer contents of ‘temp0’ into ‘rc’ “s buffer.  This, in turn, changes
the contents of ‘temp1’.  So, the last assignment ‘rc.b = temp1’,
doesn’t have the expected effect.

Keep in mind that retrieving sub-objects from Structure, Unions, and
Arrays doesn’t 'copy' the sub-object, instead it retrieves a wrapper
object accessing the root-object’s underlying buffer.

Another example that may behave differently from what one would expect
is this:

     >>> s = c_char_p()
     >>> s.value = b"abc def ghi"
     >>> s.value
     b'abc def ghi'
     >>> s.value is s.value
     False
     >>>

     Nota: Objects instantiated from *note c_char_p: 1a3f. can only have
     their value set to bytes or integers.

Why is it printing ‘False’?  ctypes instances are objects containing a
memory block plus some *note descriptor: 1869.s accessing the contents
of the memory.  Storing a Python object in the memory block does not
store the object itself, instead the ‘contents’ of the object is stored.
Accessing the contents again constructs a new Python object each time!


File: python.info,  Node: Variable-sized data types,  Prev: Surprises,  Up: ctypes tutorial

5.16.9.23 Variable-sized data types
...................................

*note ctypes: 2e. provides some support for variable-sized arrays and
structures.

The *note resize(): 3303. function can be used to resize the memory
buffer of an existing ctypes object.  The function takes the object as
first argument, and the requested size in bytes as the second argument.
The memory block cannot be made smaller than the natural memory block
specified by the objects type, a *note ValueError: 2ec. is raised if
this is tried:

     >>> short_array = (c_short * 4)()
     >>> print(sizeof(short_array))
     8
     >>> resize(short_array, 4)
     Traceback (most recent call last):
         ...
     ValueError: minimum size is 8
     >>> resize(short_array, 32)
     >>> sizeof(short_array)
     32
     >>> sizeof(type(short_array))
     8
     >>>

This is nice and fine, but how would one access the additional elements
contained in this array?  Since the type still only knows about 4
elements, we get errors accessing other elements:

     >>> short_array[:]
     [0, 0, 0, 0]
     >>> short_array[7]
     Traceback (most recent call last):
         ...
     IndexError: invalid index
     >>>

Another way to use variable-sized data types with *note ctypes: 2e. is
to use the dynamic nature of Python, and (re-)define the data type after
the required size is already known, on a case by case basis.


File: python.info,  Node: ctypes reference,  Prev: ctypes tutorial,  Up: ctypes — A foreign function library for Python

5.16.9.24 ctypes reference
..........................

* Menu:

* Finding shared libraries::
* Listing loaded shared libraries::
* Loading shared libraries::
* Foreign functions::
* Function prototypes::
* Utility functions::
* Data types::
* Fundamental data types: Fundamental data types<2>.
* Structured data types::
* Arrays and pointers::
* Exceptions: Exceptions<9>.


File: python.info,  Node: Finding shared libraries,  Next: Listing loaded shared libraries,  Up: ctypes reference

5.16.9.25 Finding shared libraries
..................................

When programming in a compiled language, shared libraries are accessed
when compiling/linking a program, and when the program is run.

The purpose of the *note find_library(): f47. function is to locate a
library in a way similar to what the compiler or runtime loader does (on
platforms with several versions of a shared library the most recent
should be loaded), while the ctypes library loaders act like when a
program is run, and call the runtime loader directly.

The ‘ctypes.util’ module provides a function which can help to determine
the library to load.

 -- Dati: ctypes.util.find_library (name)

     Try to find a library and return a pathname.  'name' is the library
     name without any prefix like 'lib', suffix like ‘.so’, ‘.dylib’ or
     version number (this is the form used for the posix linker option
     ‘-l’).  If no library can be found, returns ‘None’.

The exact functionality is system dependent.

On Linux, *note find_library(): f47. tries to run external programs
(‘/sbin/ldconfig’, ‘gcc’, ‘objdump’ and ‘ld’) to find the library file.
It returns the filename of the library file.

Note that if the output of these programs does not correspond to the
dynamic linker used by Python, the result of this function may be
misleading.

Cambiato nella versione 3.6: On Linux, the value of the environment
variable ‘LD_LIBRARY_PATH’ is used when searching for libraries, if a
library cannot be found by any other means.

Here are some examples:

     >>> from ctypes.util import find_library
     >>> find_library("m")
     'libm.so.6'
     >>> find_library("c")
     'libc.so.6'
     >>> find_library("bz2")
     'libbz2.so.1.0'
     >>>

On macOS and Android, *note find_library(): f47. uses the system’s
standard naming schemes and paths to locate the library, and returns a
full pathname if successful:

     >>> from ctypes.util import find_library
     >>> find_library("c")
     '/usr/lib/libc.dylib'
     >>> find_library("m")
     '/usr/lib/libm.dylib'
     >>> find_library("bz2")
     '/usr/lib/libbz2.dylib'
     >>> find_library("AGL")
     '/System/Library/Frameworks/AGL.framework/AGL'
     >>>

On Windows, *note find_library(): f47. searches along the system search
path, and returns the full pathname, but since there is no predefined
naming scheme a call like ‘find_library("c")’ will fail and return
‘None’.

If wrapping a shared library with *note ctypes: 2e, it 'may' be better
to determine the shared library name at development time, and hardcode
that into the wrapper module instead of using *note find_library(): f47.
to locate the library at runtime.


File: python.info,  Node: Listing loaded shared libraries,  Next: Loading shared libraries,  Prev: Finding shared libraries,  Up: ctypes reference

5.16.9.26 Listing loaded shared libraries
.........................................

When writing code that relies on code loaded from shared libraries, it
can be useful to know which shared libraries have already been loaded
into the current process.

The ‘ctypes.util’ module provides the *note dllist(): 1f0. function,
which calls the different APIs provided by the various platforms to help
determine which shared libraries have already been loaded into the
current process.

The exact output of this function will be system dependent.  On most
platforms, the first entry of this list represents the current process
itself, which may be an empty string.  For example, on glibc-based
Linux, the return may look like:

     >>> from ctypes.util import dllist
     >>> dllist()
     ['', 'linux-vdso.so.1', '/lib/x86_64-linux-gnu/libm.so.6', '/lib/x86_64-linux-gnu/libc.so.6', ... ]


File: python.info,  Node: Loading shared libraries,  Next: Foreign functions,  Prev: Listing loaded shared libraries,  Up: ctypes reference

5.16.9.27 Loading shared libraries
..................................

There are several ways to load shared libraries into the Python process.
One way is to instantiate one of the following classes:

 -- Classe: ctypes.CDLL (name, mode=DEFAULT_MODE, handle=None,
          use_errno=False, use_last_error=False, winmode=None)

     Instances of this class represent loaded shared libraries.
     Functions in these libraries use the standard C calling convention,
     and are assumed to return int.

     On Windows creating a *note CDLL: bde. instance may fail even if
     the DLL name exists.  When a dependent DLL of the loaded DLL is not
     found, a *note OSError: 2c0. error is raised with the message
     '«[WinError 126] The specified module could not be found».'  This
     error message does not contain the name of the missing DLL because
     the Windows API does not return this information making this error
     hard to diagnose.  To resolve this error and determine which DLL is
     not found, you need to find the list of dependent DLLs and
     determine which one is not found using Windows debugging and
     tracing tools.

     Cambiato nella versione 3.12: The 'name' parameter can now be a
     *note path-like object: 5a1.

Vedi anche
..........

Microsoft DUMPBIN tool(1) – A tool to find DLL dependents.

 -- Classe: ctypes.OleDLL (name, mode=DEFAULT_MODE, handle=None,
          use_errno=False, use_last_error=False, winmode=None)

     Instances of this class represent loaded shared libraries,
     functions in these libraries use the ‘stdcall’ calling convention,
     and are assumed to return the windows specific *note HRESULT: 330c.
     code.  *note HRESULT: 330c. values contain information specifying
     whether the function call failed or succeeded, together with
     additional error code.  If the return value signals a failure, an
     *note OSError: 2c0. is automatically raised.

     *note Availability: 2128.: Windows

     Cambiato nella versione 3.3: *note WindowsError: 1257. used to be
     raised, which is now an alias of *note OSError: 2c0.

     Cambiato nella versione 3.12: The 'name' parameter can now be a
     *note path-like object: 5a1.

 -- Classe: ctypes.WinDLL (name, mode=DEFAULT_MODE, handle=None,
          use_errno=False, use_last_error=False, winmode=None)

     Instances of this class represent loaded shared libraries,
     functions in these libraries use the ‘stdcall’ calling convention,
     and are assumed to return int by default.

     *note Availability: 2128.: Windows

     Cambiato nella versione 3.12: The 'name' parameter can now be a
     *note path-like object: 5a1.

The Python *note global interpreter lock: 474. is released before
calling any function exported by these libraries, and reacquired
afterwards.

 -- Classe: ctypes.PyDLL (name, mode=DEFAULT_MODE, handle=None)

     Instances of this class behave like *note CDLL: bde. instances,
     except that the Python GIL is 'not' released during the function
     call, and after the function execution the Python error flag is
     checked.  If the error flag is set, a Python exception is raised.

     Thus, this is only useful to call Python C api functions directly.

     Cambiato nella versione 3.12: The 'name' parameter can now be a
     *note path-like object: 5a1.

All these classes can be instantiated by calling them with at least one
argument, the pathname of the shared library.  If you have an existing
handle to an already loaded shared library, it can be passed as the
‘handle’ named parameter, otherwise the underlying platform’s ‘dlopen()’
or ‘LoadLibrary()’ function is used to load the library into the
process, and to get a handle to it.

The 'mode' parameter can be used to specify how the library is loaded.
For details, consult the ‘dlopen(3)(2)’ manpage.  On Windows, 'mode' is
ignored.  On posix systems, RTLD_NOW is always added, and is not
configurable.

The 'use_errno' parameter, when set to true, enables a ctypes mechanism
that allows accessing the system *note errno: 5b. error number in a safe
way.  *note ctypes: 2e. maintains a thread-local copy of the system’s
*note errno: 5b. variable; if you call foreign functions created with
‘use_errno=True’ then the *note errno: 5b. value before the function
call is swapped with the ctypes private copy, the same happens
immediately after the function call.

The function *note ctypes.get_errno(): 330d. returns the value of the
ctypes private copy, and the function *note ctypes.set_errno(): 330e.
changes the ctypes private copy to a new value and returns the former
value.

The 'use_last_error' parameter, when set to true, enables the same
mechanism for the Windows error code which is managed by the *note
GetLastError(): 32e0. and ‘SetLastError()’ Windows API functions; *note
ctypes.get_last_error(): 330f. and *note ctypes.set_last_error(): 3310.
are used to request and change the ctypes private copy of the windows
error code.

The 'winmode' parameter is used on Windows to specify how the library is
loaded (since 'mode' is ignored).  It takes any value that is valid for
the Win32 API ‘LoadLibraryEx’ flags parameter.  When omitted, the
default is to use the flags that result in the most secure DLL load,
which avoids issues such as DLL hijacking.  Passing the full path to the
DLL is the safest way to ensure the correct library and dependencies are
loaded.

Cambiato nella versione 3.8: Added 'winmode' parameter.

 -- Dati: ctypes.RTLD_GLOBAL

     Flag to use as 'mode' parameter.  On platforms where this flag is
     not available, it is defined as the integer zero.

 -- Dati: ctypes.RTLD_LOCAL

     Flag to use as 'mode' parameter.  On platforms where this is not
     available, it is the same as 'RTLD_GLOBAL'.

 -- Dati: ctypes.DEFAULT_MODE

     The default mode which is used to load shared libraries.  On OSX
     10.3, this is 'RTLD_GLOBAL', otherwise it is the same as
     'RTLD_LOCAL'.

Instances of these classes have no public methods.  Functions exported
by the shared library can be accessed as attributes or by index.  Please
note that accessing the function through an attribute caches the result
and therefore accessing it repeatedly returns the same object each time.
On the other hand, accessing it through an index returns a new object
each time:

     >>> from ctypes import CDLL
     >>> libc = CDLL("libc.so.6")  # On Linux
     >>> libc.time == libc.time
     True
     >>> libc['time'] == libc['time']
     False

The following public attributes are available, their name starts with an
underscore to not clash with exported function names:

 -- Attributo: PyDLL._handle

     The system handle used to access the library.

 -- Attributo: PyDLL._name

     The name of the library passed in the constructor.

Shared libraries can also be loaded by using one of the prefabricated
objects, which are instances of the *note LibraryLoader: 3313. class,
either by calling the *note LoadLibrary(): 32b9. method, or by
retrieving the library as attribute of the loader instance.

 -- Classe: ctypes.LibraryLoader (dlltype)

     Class which loads shared libraries.  'dlltype' should be one of the
     *note CDLL: bde, *note PyDLL: 1acc, *note WinDLL: 1acb, or *note
     OleDLL: 1aca. types.

     ‘__getattr__()’ has special behavior: It allows loading a shared
     library by accessing it as attribute of a library loader instance.
     The result is cached, so repeated attribute accesses return the
     same library each time.

      -- Metodo: LoadLibrary (name)

          Load a shared library into the process and return it.  This
          method always returns a new instance of the library.

These prefabricated library loaders are available:

 -- Dati: ctypes.cdll

     Creates *note CDLL: bde. instances.

 -- Dati: ctypes.windll

     Creates *note WinDLL: 1acb. instances.

     *note Availability: 2128.: Windows

 -- Dati: ctypes.oledll

     Creates *note OleDLL: 1aca. instances.

     *note Availability: 2128.: Windows

 -- Dati: ctypes.pydll

     Creates *note PyDLL: 1acc. instances.

For accessing the C Python api directly, a ready-to-use Python shared
library object is available:

 -- Dati: ctypes.pythonapi

     An instance of *note PyDLL: 1acc. that exposes Python C API
     functions as attributes.  Note that all these functions are assumed
     to return C int, which is of course not always the truth, so you
     have to assign the correct ‘restype’ attribute to use these
     functions.

Loading a library through any of these objects raises an *note auditing
event: 1c56. ‘ctypes.dlopen’ with string argument ‘name’, the name used
to load the library.

Accessing a function on a loaded library raises an auditing event
‘ctypes.dlsym’ with arguments ‘library’ (the library object) and ‘name’
(the symbol’s name as a string or integer).

In cases when only the library handle is available rather than the
object, accessing a function raises an auditing event
‘ctypes.dlsym/handle’ with arguments ‘handle’ (the raw library handle)
and ‘name’.

   ---------- Footnotes ----------

   (1) https://docs.microsoft.com/cpp/build/reference/dependents

   (2) https://manpages.debian.org/dlopen(3)


File: python.info,  Node: Foreign functions,  Next: Function prototypes,  Prev: Loading shared libraries,  Up: ctypes reference

5.16.9.28 Foreign functions
...........................

As explained in the previous section, foreign functions can be accessed
as attributes of loaded shared libraries.  The function objects created
in this way by default accept any number of arguments, accept any ctypes
data instances as arguments, and return the default result type
specified by the library loader.

They are instances of a private local class ‘_FuncPtr’ (not exposed in
‘ctypes’) which inherits from the private *note _CFuncPtr: 18ba. class:

     >>> import ctypes
     >>> lib = ctypes.CDLL(None)
     >>> issubclass(lib._FuncPtr, ctypes._CFuncPtr)
     True
     >>> lib._FuncPtr is ctypes._CFuncPtr
     False

 -- Classe: ctypes._CFuncPtr

     Base class for C callable foreign functions.

     Instances of foreign functions are also C compatible data types;
     they represent C function pointers.

     This behavior can be customized by assigning to special attributes
     of the foreign function object.

      -- Attributo: restype

          Assign a ctypes type to specify the result type of the foreign
          function.  Use ‘None’ for void, a function not returning
          anything.

          It is possible to assign a callable Python object that is not
          a ctypes type, in this case the function is assumed to return
          a C int, and the callable will be called with this integer,
          allowing further processing or error checking.  Using this is
          deprecated, for more flexible post processing or error
          checking use a ctypes data type as ‘restype’ and assign a
          callable to the *note errcheck: 32e1. attribute.

      -- Attributo: argtypes

          Assign a tuple of ctypes types to specify the argument types
          that the function accepts.  Functions using the ‘stdcall’
          calling convention can only be called with the same number of
          arguments as the length of this tuple; functions using the C
          calling convention accept additional, unspecified arguments as
          well.

          When a foreign function is called, each actual argument is
          passed to the *note from_param(): 32dc. class method of the
          items in the *note argtypes: 17a9. tuple, this method allows
          adapting the actual argument to an object that the foreign
          function accepts.  For example, a *note c_char_p: 1a3f. item
          in the *note argtypes: 17a9. tuple will convert a string
          passed as argument into a bytes object using ctypes conversion
          rules.

          New: It is now possible to put items in argtypes which are not
          ctypes types, but each item must have a *note from_param():
          32dc. method which returns a value usable as argument
          (integer, string, ctypes instance).  This allows defining
          adapters that can adapt custom objects as function parameters.

      -- Attributo: errcheck

          Assign a Python function or another callable to this
          attribute.  The callable will be called with three or more
          arguments:

           -- Funzione: callable (result, func, arguments)

               'result' is what the foreign function returns, as
               specified by the ‘restype’ attribute.

               'func' is the foreign function object itself, this allows
               reusing the same callable object to check or post process
               the results of several functions.

               'arguments' is a tuple containing the parameters
               originally passed to the function call, this allows
               specializing the behavior on the arguments used.

          The object that this function returns will be returned from
          the foreign function call, but it can also check the result
          value and raise an exception if the foreign function call
          failed.

On Windows, when a foreign function call raises a system exception (for
example, due to an access violation), it will be captured and replaced
with a suitable Python exception.  Further, an auditing event
‘ctypes.set_exception’ with argument ‘code’ will be raised, allowing an
audit hook to replace the exception with its own.

Some ways to invoke foreign function calls as well as some of the
functions in this module may raise an auditing event
‘ctypes.call_function’ with arguments ‘function pointer’ and
‘arguments’.


File: python.info,  Node: Function prototypes,  Next: Utility functions,  Prev: Foreign functions,  Up: ctypes reference

5.16.9.29 Function prototypes
.............................

Foreign functions can also be created by instantiating function
prototypes.  Function prototypes are similar to function prototypes in
C; they describe a function (return type, argument types, calling
convention) without defining an implementation.  The factory functions
must be called with the desired result type and the argument types of
the function, and can be used as decorator factories, and as such, be
applied to functions through the ‘@wrapper’ syntax.  See *note Callback
functions: 32f8. for examples.

 -- Funzione: ctypes.CFUNCTYPE (restype, *argtypes, use_errno=False,
          use_last_error=False)

     The returned function prototype creates functions that use the
     standard C calling convention.  The function will release the GIL
     during the call.  If 'use_errno' is set to true, the ctypes private
     copy of the system *note errno: 5b. variable is exchanged with the
     real *note errno: 5b. value before and after the call;
     'use_last_error' does the same for the Windows error code.

 -- Funzione: ctypes.WINFUNCTYPE (restype, *argtypes, use_errno=False,
          use_last_error=False)

     The returned function prototype creates functions that use the
     ‘stdcall’ calling convention.  The function will release the GIL
     during the call.  'use_errno' and 'use_last_error' have the same
     meaning as above.

     *note Availability: 2128.: Windows

 -- Funzione: ctypes.PYFUNCTYPE (restype, *argtypes)

     The returned function prototype creates functions that use the
     Python calling convention.  The function will 'not' release the GIL
     during the call.

Function prototypes created by these factory functions can be
instantiated in different ways, depending on the type and number of the
parameters in the call:

 -- Funzione: prototype (address)

     Returns a foreign function at the specified address which must be
     an integer.

 -- Funzione: prototype (callable)

     Create a C callable function (a callback function) from a Python
     'callable'.

 -- Funzione: prototype (func_spec[, paramflags])

     Returns a foreign function exported by a shared library.
     'func_spec' must be a 2-tuple ‘(name_or_ordinal, library)’.  The
     first item is the name of the exported function as string, or the
     ordinal of the exported function as small integer.  The second item
     is the shared library instance.

 -- Funzione: prototype (vtbl_index, name[, paramflags[, iid]])

     Returns a foreign function that will call a COM method.
     'vtbl_index' is the index into the virtual function table, a small
     non-negative integer.  'name' is name of the COM method.  'iid' is
     an optional pointer to the interface identifier which is used in
     extended error reporting.

     If 'iid' is not specified, an *note OSError: 2c0. is raised if the
     COM method call fails.  If 'iid' is specified, a *note COMError:
     1e9. is raised instead.

     COM methods use a special calling convention: They require a
     pointer to the COM interface as first argument, in addition to
     those parameters that are specified in the ‘argtypes’ tuple.

     *note Availability: 2128.: Windows

The optional 'paramflags' parameter creates foreign function wrappers
with much more functionality than the features described above.

'paramflags' must be a tuple of the same length as *note argtypes: 17a9.

Each item in this tuple contains further information about a parameter,
it must be a tuple containing one, two, or three items.

The first item is an integer containing a combination of direction flags
for the parameter:

     1

          Specifies an input parameter to the function.

     2

          Output parameter.  The foreign function fills in a value.

     4

          Input parameter which defaults to the integer zero.

The optional second item is the parameter name as string.  If this is
specified, the foreign function can be called with named parameters.

The optional third item is the default value for this parameter.

The following example demonstrates how to wrap the Windows ‘MessageBoxW’
function so that it supports default parameters and named arguments.
The C declaration from the windows header file is this:

     WINUSERAPI int WINAPI
     MessageBoxW(
         HWND hWnd,
         LPCWSTR lpText,
         LPCWSTR lpCaption,
         UINT uType);

Here is the wrapping with *note ctypes: 2e.:

     >>> from ctypes import c_int, WINFUNCTYPE, windll
     >>> from ctypes.wintypes import HWND, LPCWSTR, UINT
     >>> prototype = WINFUNCTYPE(c_int, HWND, LPCWSTR, LPCWSTR, UINT)
     >>> paramflags = (1, "hwnd", 0), (1, "text", "Hi"), (1, "caption", "Hello from ctypes"), (1, "flags", 0)
     >>> MessageBox = prototype(("MessageBoxW", windll.user32), paramflags)

The ‘MessageBox’ foreign function can now be called in these ways:

     >>> MessageBox()
     >>> MessageBox(text="Spam, spam, spam")
     >>> MessageBox(flags=2, text="foo bar")

A second example demonstrates output parameters.  The win32
‘GetWindowRect’ function retrieves the dimensions of a specified window
by copying them into ‘RECT’ structure that the caller has to supply.
Here is the C declaration:

     WINUSERAPI BOOL WINAPI
     GetWindowRect(
          HWND hWnd,
          LPRECT lpRect);

Here is the wrapping with *note ctypes: 2e.:

     >>> from ctypes import POINTER, WINFUNCTYPE, windll, WinError
     >>> from ctypes.wintypes import BOOL, HWND, RECT
     >>> prototype = WINFUNCTYPE(BOOL, HWND, POINTER(RECT))
     >>> paramflags = (1, "hwnd"), (2, "lprect")
     >>> GetWindowRect = prototype(("GetWindowRect", windll.user32), paramflags)
     >>>

Functions with output parameters will automatically return the output
parameter value if there is a single one, or a tuple containing the
output parameter values when there are more than one, so the
GetWindowRect function now returns a RECT instance, when called.

Output parameters can be combined with the *note errcheck: 32e1.
protocol to do further output processing and error checking.  The win32
‘GetWindowRect’ api function returns a ‘BOOL’ to signal success or
failure, so this function could do the error checking, and raises an
exception when the api call failed:

     >>> def errcheck(result, func, args):
     ...     if not result:
     ...         raise WinError()
     ...     return args
     ...
     >>> GetWindowRect.errcheck = errcheck
     >>>

If the *note errcheck: 32e1. function returns the argument tuple it
receives unchanged, *note ctypes: 2e. continues the normal processing it
does on the output parameters.  If you want to return a tuple of window
coordinates instead of a ‘RECT’ instance, you can retrieve the fields in
the function and return them instead, the normal processing will no
longer take place:

     >>> def errcheck(result, func, args):
     ...     if not result:
     ...         raise WinError()
     ...     rc = args[1]
     ...     return rc.left, rc.top, rc.bottom, rc.right
     ...
     >>> GetWindowRect.errcheck = errcheck
     >>>


File: python.info,  Node: Utility functions,  Next: Data types,  Prev: Function prototypes,  Up: ctypes reference

5.16.9.30 Utility functions
...........................

 -- Funzione: ctypes.addressof (obj)

     Returns the address of the memory buffer as integer.  'obj' must be
     an instance of a ctypes type.

     Raises an *note auditing event: 1c56. ‘ctypes.addressof’ with
     argument ‘obj’.

 -- Funzione: ctypes.alignment (obj_or_type)

     Returns the alignment requirements of a ctypes type.  'obj_or_type'
     must be a ctypes type or instance.

 -- Funzione: ctypes.byref (obj[, offset])

     Returns a light-weight pointer to 'obj', which must be an instance
     of a ctypes type.  'offset' defaults to zero, and must be an
     integer that will be added to the internal pointer value.

     ‘byref(obj, offset)’ corresponds to this C code:

          (((char *)&obj) + offset)

     The returned object can only be used as a foreign function call
     parameter.  It behaves similar to ‘pointer(obj)’, but the
     construction is a lot faster.

 -- Funzione: ctypes.CopyComPointer (src, dst)

     Copies a COM pointer from 'src' to 'dst' and returns the Windows
     specific ‘HRESULT’ value.

     If 'src' is not ‘NULL’, its ‘AddRef’ method is called, incrementing
     the reference count.

     In contrast, the reference count of 'dst' will not be decremented
     before assigning the new value.  Unless 'dst' is ‘NULL’, the caller
     is responsible for decrementing the reference count by calling its
     ‘Release’ method when necessary.

     *note Availability: 2128.: Windows

     Added in version 3.14.

 -- Funzione: ctypes.cast (obj, type)

     This function is similar to the cast operator in C. It returns a
     new instance of 'type' which points to the same memory block as
     'obj'.  'type' must be a pointer type, and 'obj' must be an object
     that can be interpreted as a pointer.

 -- Funzione: ctypes.create_string_buffer (init, size=None)

 -- Funzione: ctypes.create_string_buffer (size)

     This function creates a mutable character buffer.  The returned
     object is a ctypes array of *note c_char: 32c1.

     If 'size' is given (and not ‘None’), it must be an *note int: 19b.
     It specifies the size of the returned array.

     If the 'init' argument is given, it must be *note bytes: 192.  It
     is used to initialize the array items.  Bytes not initialized this
     way are set to zero (NUL).

     If 'size' is not given (or if it is ‘None’), the buffer is made one
     element larger than 'init', effectively adding a NUL terminator.

     If both arguments are given, 'size' must not be less than
     ‘len(init)’.

          Avvertimento: If 'size' is equal to ‘len(init)’, a NUL
          terminator is not added.  Do not treat such a buffer as a C
          string.

     For example:

          >>> bytes(create_string_buffer(2))
          b'\x00\x00'
          >>> bytes(create_string_buffer(b'ab'))
          b'ab\x00'
          >>> bytes(create_string_buffer(b'ab', 2))
          b'ab'
          >>> bytes(create_string_buffer(b'ab', 4))
          b'ab\x00\x00'
          >>> bytes(create_string_buffer(b'abcdef', 2))
          Traceback (most recent call last):
             ...
          ValueError: byte string too long

     Raises an *note auditing event: 1c56. ‘ctypes.create_string_buffer’
     with arguments ‘init’, ‘size’.

 -- Funzione: ctypes.create_unicode_buffer (init, size=None)

 -- Funzione: ctypes.create_unicode_buffer (size)

     This function creates a mutable unicode character buffer.  The
     returned object is a ctypes array of *note c_wchar: 32c2.

     The function takes the same arguments as *note
     create_string_buffer(): 32d3. except 'init' must be a string and
     'size' counts *note c_wchar: 32c2.

     Raises an *note auditing event: 1c56.
     ‘ctypes.create_unicode_buffer’ with arguments ‘init’, ‘size’.

 -- Funzione: ctypes.DllCanUnloadNow ()

     This function is a hook which allows implementing in-process COM
     servers with ctypes.  It is called from the DllCanUnloadNow
     function that the _ctypes extension dll exports.

     *note Availability: 2128.: Windows

 -- Funzione: ctypes.DllGetClassObject ()

     This function is a hook which allows implementing in-process COM
     servers with ctypes.  It is called from the DllGetClassObject
     function that the ‘_ctypes’ extension dll exports.

     *note Availability: 2128.: Windows

 -- Funzione: ctypes.util.find_library (name)

     Try to find a library and return a pathname.  'name' is the library
     name without any prefix like ‘lib’, suffix like ‘.so’, ‘.dylib’ or
     version number (this is the form used for the posix linker option
     ‘-l’).  If no library can be found, returns ‘None’.

     The exact functionality is system dependent.

     See *note Finding shared libraries: 3306. for complete
     documentation.

 -- Funzione: ctypes.util.find_msvcrt ()

     Returns the filename of the VC runtime library used by Python, and
     by the extension modules.  If the name of the library cannot be
     determined, ‘None’ is returned.

     If you need to free memory, for example, allocated by an extension
     module with a call to the ‘free(void *)’, it is important that you
     use the function in the same library that allocated the memory.

     *note Availability: 2128.: Windows

 -- Funzione: ctypes.util.dllist ()

     Try to provide a list of paths of the shared libraries loaded into
     the current process.  These paths are not normalized or processed
     in any way.  The function can raise *note OSError: 2c0. if the
     underlying platform APIs fail.  The exact functionality is system
     dependent.

     On most platforms, the first element of the list represents the
     current executable file.  It may be an empty string.

     *note Availability: 2128.: Windows, macOS, iOS, glibc, BSD libc,
     musl

     Added in version 3.14.

 -- Funzione: ctypes.FormatError ([code])

     Returns a textual description of the error code 'code'.  If no
     error code is specified, the last error code is used by calling the
     Windows API function *note GetLastError(): 32e0.

     *note Availability: 2128.: Windows

 -- Funzione: ctypes.GetLastError ()

     Returns the last error code set by Windows in the calling thread.
     This function calls the Windows ‘GetLastError()’ function directly,
     it does not return the ctypes-private copy of the error code.

     *note Availability: 2128.: Windows

 -- Funzione: ctypes.get_errno ()

     Returns the current value of the ctypes-private copy of the system
     *note errno: 5b. variable in the calling thread.

     Raises an *note auditing event: 1c56. ‘ctypes.get_errno’ with no
     arguments.

 -- Funzione: ctypes.get_last_error ()

     Returns the current value of the ctypes-private copy of the system
     ‘LastError’ variable in the calling thread.

     *note Availability: 2128.: Windows

     Raises an *note auditing event: 1c56. ‘ctypes.get_last_error’ with
     no arguments.

 -- Funzione: ctypes.memmove (dst, src, count)

     Same as the standard C memmove library function: copies 'count'
     bytes from 'src' to 'dst'.  'dst' and 'src' must be integers or
     ctypes instances that can be converted to pointers.

 -- Funzione: ctypes.memset (dst, c, count)

     Same as the standard C memset library function: fills the memory
     block at address 'dst' with 'count' bytes of value 'c'.  'dst' must
     be an integer specifying an address, or a ctypes instance.

 -- Funzione: ctypes.POINTER (type, /)

     Create or return a ctypes pointer type.  Pointer types are cached
     and reused internally, so calling this function repeatedly is
     cheap.  'type' must be a ctypes type.

     'Dettaglio dell’implementazione di CPython:' The resulting pointer
     type is cached in the ‘__pointer_type__’ attribute of 'type'.  It
     is possible to set this attribute before the first call to
     ‘POINTER’ in order to set a custom pointer type.  However, doing
     this is discouraged: manually creating a suitable pointer type is
     difficult without relying on implementation details that may change
     in future Python versions.

 -- Funzione: ctypes.pointer (obj, /)

     Create a new pointer instance, pointing to 'obj'.  The returned
     object is of the type ‘POINTER(type(obj))’.

     Note: If you just want to pass a pointer to an object to a foreign
     function call, you should use ‘byref(obj)’ which is much faster.

 -- Funzione: ctypes.resize (obj, size)

     This function resizes the internal memory buffer of 'obj', which
     must be an instance of a ctypes type.  It is not possible to make
     the buffer smaller than the native size of the objects type, as
     given by ‘sizeof(type(obj))’, but it is possible to enlarge the
     buffer.

 -- Funzione: ctypes.set_errno (value)

     Set the current value of the ctypes-private copy of the system
     *note errno: 5b. variable in the calling thread to 'value' and
     return the previous value.

     Raises an *note auditing event: 1c56. ‘ctypes.set_errno’ with
     argument ‘errno’.

 -- Funzione: ctypes.set_last_error (value)

     Sets the current value of the ctypes-private copy of the system
     ‘LastError’ variable in the calling thread to 'value' and return
     the previous value.

     *note Availability: 2128.: Windows

     Raises an *note auditing event: 1c56. ‘ctypes.set_last_error’ with
     argument ‘error’.

 -- Funzione: ctypes.sizeof (obj_or_type)

     Returns the size in bytes of a ctypes type or instance memory
     buffer.  Does the same as the C ‘sizeof’ operator.

 -- Funzione: ctypes.string_at (ptr, size=-1)

     Return the byte string at 'void *ptr'.  If 'size' is specified, it
     is used as size, otherwise the string is assumed to be
     zero-terminated.

     Raises an *note auditing event: 1c56. ‘ctypes.string_at’ with
     arguments ‘ptr’, ‘size’.

 -- Funzione: ctypes.WinError (code=None, descr=None)

     Creates an instance of *note OSError: 2c0.  If 'code' is not
     specified, *note GetLastError(): 32e0. is called to determine the
     error code.  If 'descr' is not specified, *note FormatError():
     3320. is called to get a textual description of the error.

     *note Availability: 2128.: Windows

     Cambiato nella versione 3.3: An instance of *note WindowsError:
     1257. used to be created, which is now an alias of *note OSError:
     2c0.

 -- Funzione: ctypes.wstring_at (ptr, size=-1)

     Return the wide-character string at 'void *ptr'.  If 'size' is
     specified, it is used as the number of characters of the string,
     otherwise the string is assumed to be zero-terminated.

     Raises an *note auditing event: 1c56. ‘ctypes.wstring_at’ with
     arguments ‘ptr’, ‘size’.

 -- Funzione: ctypes.memoryview_at (ptr, size, readonly=False)

     Return a *note memoryview: 165. object of length 'size' that
     references memory starting at 'void *ptr'.

     If 'readonly' is true, the returned ‘memoryview’ object can not be
     used to modify the underlying memory.  (Changes made by other means
     will still be reflected in the returned object.)

     This function is similar to *note string_at(): 1ec. with the key
     difference of not making a copy of the specified memory.  It is a
     semantically equivalent (but more efficient) alternative to
     ‘memoryview((c_byte * size).from_address(ptr))’.  (While *note
     from_address(): 3326. only takes integers, 'ptr' can also be given
     as a *note ctypes.POINTER: 1f1. or a *note byref(): 32e4. object.)

     Raises an *note auditing event: 1c56. ‘ctypes.memoryview_at’ with
     arguments ‘address’, ‘size’, ‘readonly’.

     Added in version 3.14.


File: python.info,  Node: Data types,  Next: Fundamental data types<2>,  Prev: Utility functions,  Up: ctypes reference

5.16.9.31 Data types
....................

 -- Classe: ctypes._CData

     This non-public class is the common base class of all ctypes data
     types.  Among other things, all ctypes type instances contain a
     memory block that hold C compatible data; the address of the memory
     block is returned by the *note addressof(): 331b. helper function.
     Another instance variable is exposed as *note _objects: 332a.; this
     contains other Python objects that need to be kept alive in case
     the memory block contains pointers.

     Common methods of ctypes data types, these are all class methods
     (to be exact, they are methods of the *note metaclass: 23b6.):

      -- Metodo: from_buffer (source[, offset])

          This method returns a ctypes instance that shares the buffer
          of the 'source' object.  The 'source' object must support the
          writeable buffer interface.  The optional 'offset' parameter
          specifies an offset into the source buffer in bytes; the
          default is zero.  If the source buffer is not large enough a
          *note ValueError: 2ec. is raised.

          Raises an *note auditing event: 1c56. ‘ctypes.cdata/buffer’
          with arguments ‘pointer’, ‘size’, ‘offset’.

      -- Metodo: from_buffer_copy (source[, offset])

          This method creates a ctypes instance, copying the buffer from
          the 'source' object buffer which must be readable.  The
          optional 'offset' parameter specifies an offset into the
          source buffer in bytes; the default is zero.  If the source
          buffer is not large enough a *note ValueError: 2ec. is raised.

          Raises an *note auditing event: 1c56. ‘ctypes.cdata/buffer’
          with arguments ‘pointer’, ‘size’, ‘offset’.

      -- Metodo: from_address (address)

          This method returns a ctypes type instance using the memory
          specified by 'address' which must be an integer.

          This method, and others that indirectly call this method,
          raises an *note auditing event: 1c56. ‘ctypes.cdata’ with
          argument ‘address’.

      -- Metodo: from_param (obj)

          This method adapts 'obj' to a ctypes type.  It is called with
          the actual object used in a foreign function call when the
          type is present in the foreign function’s *note argtypes:
          17a9. tuple; it must return an object that can be used as a
          function call parameter.

          All ctypes data types have a default implementation of this
          classmethod that normally returns 'obj' if that is an instance
          of the type.  Some types accept other objects as well.

      -- Metodo: in_dll (library, name)

          This method returns a ctypes type instance exported by a
          shared library.  'name' is the name of the symbol that exports
          the data, 'library' is the loaded shared library.

     Common class variables of ctypes data types:

      -- Attributo: __pointer_type__

          The pointer type that was created by calling *note POINTER():
          1f1. for corresponding ctypes data type.  If a pointer type
          was not yet created, the attribute is missing.

          Added in version 3.14.

     Common instance variables of ctypes data types:

      -- Attributo: _b_base_

          Sometimes ctypes data instances do not own the memory block
          they contain, instead they share part of the memory block of a
          base object.  The *note _b_base_: 332d. read-only member is
          the root ctypes object that owns the memory block.

      -- Attributo: _b_needsfree_

          This read-only variable is true when the ctypes data instance
          has allocated the memory block itself, false otherwise.

      -- Attributo: _objects

          This member is either ‘None’ or a dictionary containing Python
          objects that need to be kept alive so that the memory block
          contents is kept valid.  This object is only exposed for
          debugging; never modify the contents of this dictionary.


File: python.info,  Node: Fundamental data types<2>,  Next: Structured data types,  Prev: Data types,  Up: ctypes reference

5.16.9.32 Fundamental data types
................................

 -- Classe: ctypes._SimpleCData

     This non-public class is the base class of all fundamental ctypes
     data types.  It is mentioned here because it contains the common
     attributes of the fundamental ctypes data types.  *note
     _SimpleCData: 3331. is a subclass of *note _CData: 3329, so it
     inherits their methods and attributes.  ctypes data types that are
     not and do not contain pointers can now be pickled.

     Instances have a single attribute:

      -- Attributo: value

          This attribute contains the actual value of the instance.  For
          integer and pointer types, it is an integer, for character
          types, it is a single character bytes object or string, for
          character pointer types it is a Python bytes object or string.

          When the ‘value’ attribute is retrieved from a ctypes
          instance, usually a new object is returned each time.  *note
          ctypes: 2e. does 'not' implement original object return,
          always a new object is constructed.  The same is true for all
          other ctypes object instances.

Fundamental data types, when returned as foreign function call results,
or, for example, by retrieving structure field members or array items,
are transparently converted to native Python types.  In other words, if
a foreign function has a *note restype: 32df. of *note c_char_p: 1a3f,
you will always receive a Python bytes object, 'not' a *note c_char_p:
1a3f. instance.

Subclasses of fundamental data types do 'not' inherit this behavior.
So, if a foreign functions ‘restype’ is a subclass of *note c_void_p:
1a41, you will receive an instance of this subclass from the function
call.  Of course, you can get the value of the pointer by accessing the
‘value’ attribute.

These are the fundamental ctypes data types:

 -- Classe: ctypes.c_byte

     Represents the C signed char datatype, and interprets the value as
     small integer.  The constructor accepts an optional integer
     initializer; no overflow checking is done.

 -- Classe: ctypes.c_char

     Represents the C char datatype, and interprets the value as a
     single character.  The constructor accepts an optional string
     initializer, the length of the string must be exactly one
     character.

 -- Classe: ctypes.c_char_p

     Represents the C char* datatype when it points to a zero-terminated
     string.  For a general character pointer that may also point to
     binary data, ‘POINTER(c_char)’ must be used.  The constructor
     accepts an integer address, or a bytes object.

 -- Classe: ctypes.c_double

     Represents the C double datatype.  The constructor accepts an
     optional float initializer.

 -- Classe: ctypes.c_longdouble

     Represents the C long double datatype.  The constructor accepts an
     optional float initializer.  On platforms where ‘sizeof(long
     double) == sizeof(double)’ it is an alias to *note c_double: 1ca0.

 -- Classe: ctypes.c_float

     Represents the C float datatype.  The constructor accepts an
     optional float initializer.

 -- Classe: ctypes.c_double_complex

     Represents the C double complex datatype, if available.  The
     constructor accepts an optional *note complex: 197. initializer.

     Added in version 3.14.

 -- Classe: ctypes.c_float_complex

     Represents the C float complex datatype, if available.  The
     constructor accepts an optional *note complex: 197. initializer.

     Added in version 3.14.

 -- Classe: ctypes.c_longdouble_complex

     Represents the C long double complex datatype, if available.  The
     constructor accepts an optional *note complex: 197. initializer.

     Added in version 3.14.

 -- Classe: ctypes.c_int

     Represents the C signed int datatype.  The constructor accepts an
     optional integer initializer; no overflow checking is done.  On
     platforms where ‘sizeof(int) == sizeof(long)’ it is an alias to
     *note c_long: 32b6.

 -- Classe: ctypes.c_int8

     Represents the C 8-bit signed int datatype.  It is an alias for
     *note c_byte: 1ac8.

 -- Classe: ctypes.c_int16

     Represents the C 16-bit signed int datatype.  Usually an alias for
     *note c_short: 32c3.

 -- Classe: ctypes.c_int32

     Represents the C 32-bit signed int datatype.  Usually an alias for
     *note c_int: 32b5.

 -- Classe: ctypes.c_int64

     Represents the C 64-bit signed int datatype.  Usually an alias for
     *note c_longlong: 32cf.

 -- Classe: ctypes.c_long

     Represents the C signed long datatype.  The constructor accepts an
     optional integer initializer; no overflow checking is done.

 -- Classe: ctypes.c_longlong

     Represents the C signed long long datatype.  The constructor
     accepts an optional integer initializer; no overflow checking is
     done.

 -- Classe: ctypes.c_short

     Represents the C signed short datatype.  The constructor accepts an
     optional integer initializer; no overflow checking is done.

 -- Classe: ctypes.c_size_t

     Represents the C ‘size_t’ datatype.

 -- Classe: ctypes.c_ssize_t

     Represents the C ‘ssize_t’ datatype.

     Added in version 3.2.

 -- Classe: ctypes.c_time_t

     Represents the C ‘time_t’ datatype.

     Added in version 3.12.

 -- Classe: ctypes.c_ubyte

     Represents the C unsigned char datatype, it interprets the value as
     small integer.  The constructor accepts an optional integer
     initializer; no overflow checking is done.

 -- Classe: ctypes.c_uint

     Represents the C unsigned int datatype.  The constructor accepts an
     optional integer initializer; no overflow checking is done.  On
     platforms where ‘sizeof(int) == sizeof(long)’ it is an alias for
     *note c_ulong: 32ce.

 -- Classe: ctypes.c_uint8

     Represents the C 8-bit unsigned int datatype.  It is an alias for
     *note c_ubyte: 1ac9.

 -- Classe: ctypes.c_uint16

     Represents the C 16-bit unsigned int datatype.  Usually an alias
     for *note c_ushort: 32c4.

 -- Classe: ctypes.c_uint32

     Represents the C 32-bit unsigned int datatype.  Usually an alias
     for *note c_uint: 32c9.

 -- Classe: ctypes.c_uint64

     Represents the C 64-bit unsigned int datatype.  Usually an alias
     for *note c_ulonglong: 32d0.

 -- Classe: ctypes.c_ulong

     Represents the C unsigned long datatype.  The constructor accepts
     an optional integer initializer; no overflow checking is done.

 -- Classe: ctypes.c_ulonglong

     Represents the C unsigned long long datatype.  The constructor
     accepts an optional integer initializer; no overflow checking is
     done.

 -- Classe: ctypes.c_ushort

     Represents the C unsigned short datatype.  The constructor accepts
     an optional integer initializer; no overflow checking is done.

 -- Classe: ctypes.c_void_p

     Represents the C void* type.  The value is represented as integer.
     The constructor accepts an optional integer initializer.

 -- Classe: ctypes.c_wchar

     Represents the C ‘wchar_t’ datatype, and interprets the value as a
     single character unicode string.  The constructor accepts an
     optional string initializer, the length of the string must be
     exactly one character.

 -- Classe: ctypes.c_wchar_p

     Represents the C wchar_t* datatype, which must be a pointer to a
     zero-terminated wide character string.  The constructor accepts an
     integer address, or a string.

 -- Classe: ctypes.c_bool

     Represent the C bool datatype (more accurately, _Bool from C99).
     Its value can be ‘True’ or ‘False’, and the constructor accepts any
     object that has a truth value.

 -- Classe: ctypes.HRESULT

     Represents a ‘HRESULT’ value, which contains success or error
     information for a function or method call.

     *note Availability: 2128.: Windows

 -- Classe: ctypes.py_object

     Represents the C *note PyObject: 5df.* datatype.  Calling this
     without an argument creates a ‘NULL’ *note PyObject: 5df.* pointer.

     Cambiato nella versione 3.14: ‘py_object’ is now a *note generic
     type: 1a1.

The ‘ctypes.wintypes’ module provides quite some other Windows specific
data types, for example ‘HWND’, ‘WPARAM’, or ‘DWORD’.  Some useful
structures like ‘MSG’ or ‘RECT’ are also defined.


File: python.info,  Node: Structured data types,  Next: Arrays and pointers,  Prev: Fundamental data types<2>,  Up: ctypes reference

5.16.9.33 Structured data types
...............................

 -- Classe: ctypes.Union (*args, **kw)

     Abstract base class for unions in native byte order.

     Unions share common attributes and behavior with structures; see
     *note Structure: 1e5. documentation for details.

 -- Classe: ctypes.BigEndianUnion (*args, **kw)

     Abstract base class for unions in 'big endian' byte order.

     Added in version 3.11.

 -- Classe: ctypes.LittleEndianUnion (*args, **kw)

     Abstract base class for unions in 'little endian' byte order.

     Added in version 3.11.

 -- Classe: ctypes.BigEndianStructure (*args, **kw)

     Abstract base class for structures in 'big endian' byte order.

 -- Classe: ctypes.LittleEndianStructure (*args, **kw)

     Abstract base class for structures in 'little endian' byte order.

Structures and unions with non-native byte order cannot contain pointer
type fields, or any other data types containing pointer type fields.

 -- Classe: ctypes.Structure (*args, **kw)

     Abstract base class for structures in 'native' byte order.

     Concrete structure and union types must be created by subclassing
     one of these types, and at least define a *note _fields_: 191e.
     class variable.  *note ctypes: 2e. will create *note descriptor:
     1869.s which allow reading and writing the fields by direct
     attribute accesses.  These are the

      -- Attributo: _fields_

          A sequence defining the structure fields.  The items must be
          2-tuples or 3-tuples.  The first item is the name of the
          field, the second item specifies the type of the field; it can
          be any ctypes data type.

          For integer type fields like *note c_int: 32b5, a third
          optional item can be given.  It must be a small positive
          integer defining the bit width of the field.

          Field names must be unique within one structure or union.
          This is not checked, only one field can be accessed when names
          are repeated.

          It is possible to define the *note _fields_: 191e. class
          variable 'after' the class statement that defines the
          Structure subclass, this allows creating data types that
          directly or indirectly reference themselves:

               class List(Structure):
                   pass
               List._fields_ = [("pnext", POINTER(List)),
                                ...
                               ]

          The ‘_fields_’ class variable can only be set once.  Later
          assignments will raise an *note AttributeError: 5f0.

          Additionally, the ‘_fields_’ class variable must be defined
          before the structure or union type is first used: an instance
          or subclass is created, *note sizeof(): 3323. is called on it,
          and so on.  Later assignments to ‘_fields_’ will raise an
          *note AttributeError: 5f0.  If ‘_fields_’ has not been set
          before such use, the structure or union will have no own
          fields, as if ‘_fields_’ was empty.

          Sub-subclasses of structure types inherit the fields of the
          base class plus the *note _fields_: 191e. defined in the
          sub-subclass, if any.

      -- Attributo: _pack_

          An optional small integer that allows overriding the alignment
          of structure fields in the instance.

          This is only implemented for the MSVC-compatible memory layout
          (see *note _layout_: 1e7.).

          Setting ‘_pack_’ to 0 is the same as not setting it at all.
          Otherwise, the value must be a positive power of two.  The
          effect is equivalent to ‘#pragma pack(N)’ in C, except *note
          ctypes: 2e. may allow larger 'n' than what the compiler
          accepts.

          ‘_pack_’ must already be defined when *note _fields_: 191e. is
          assigned, otherwise it will have no effect.

          Deprecated since version 3.14, will be removed in version
          3.19: For historical reasons, if ‘_pack_’ is non-zero, the
          MSVC-compatible layout will be used by default.  On
          non-Windows platforms, this default is deprecated and is
          slated to become an error in Python 3.19.  If it is intended,
          set *note _layout_: 1e7. to ‘'ms'’ explicitly.

      -- Attributo: _align_

          An optional small integer that allows increasing the alignment
          of the structure when being packed or unpacked to/from memory.

          The value must not be negative.  The effect is equivalent to
          ‘__attribute__((aligned(N)))’ on GCC or ‘#pragma align(N)’ on
          MSVC, except *note ctypes: 2e. may allow values that the
          compiler would reject.

          ‘_align_’ can only 'increase' a structure’s alignment
          requirements.  Setting it to 0 or 1 has no effect.

          Using values that are not powers of two is discouraged and may
          lead to surprising behavior.

          ‘_align_’ must already be defined when *note _fields_: 191e.
          is assigned, otherwise it will have no effect.

          Added in version 3.13.

      -- Attributo: _layout_

          An optional string naming the struct/union layout.  It can
          currently be set to:

             - ‘"ms"’: the layout used by the Microsoft compiler (MSVC).
               On GCC and Clang, this layout can be selected with
               ‘__attribute__((ms_struct))’.

             - ‘"gcc-sysv"’: the layout used by GCC with the System V or
               “SysV-like” data model, as used on Linux and macOS. With
               this layout, *note _pack_: 317. must be unset or zero.

          If not set explicitly, ‘ctypes’ will use a default that
          matches the platform conventions.  This default may change in
          future Python releases (for example, when a new platform gains
          official support, or when a difference between similar
          platforms is found).  Currently the default will be:

             - On Windows: ‘"ms"’

             - When *note _pack_: 317. is specified: ‘"ms"’.  (This is
               deprecated; see *note _pack_: 317. documentation.)

             - Otherwise: ‘"gcc-sysv"’

          ‘_layout_’ must already be defined when *note _fields_: 191e.
          is assigned, otherwise it will have no effect.

          Added in version 3.14.

      -- Attributo: _anonymous_

          An optional sequence that lists the names of unnamed
          (anonymous) fields.  *note _anonymous_: 3335. must be already
          defined when *note _fields_: 191e. is assigned, otherwise it
          will have no effect.

          The fields listed in this variable must be structure or union
          type fields.  *note ctypes: 2e. will create descriptors in the
          structure type that allows accessing the nested fields
          directly, without the need to create the structure or union
          field.

          Here is an example type (Windows):

               class _U(Union):
                   _fields_ = [("lptdesc", POINTER(TYPEDESC)),
                               ("lpadesc", POINTER(ARRAYDESC)),
                               ("hreftype", HREFTYPE)]

               class TYPEDESC(Structure):
                   _anonymous_ = ("u",)
                   _fields_ = [("u", _U),
                               ("vt", VARTYPE)]

          The ‘TYPEDESC’ structure describes a COM data type, the ‘vt’
          field specifies which one of the union fields is valid.  Since
          the ‘u’ field is defined as anonymous field, it is now
          possible to access the members directly off the TYPEDESC
          instance.  ‘td.lptdesc’ and ‘td.u.lptdesc’ are equivalent, but
          the former is faster since it does not need to create a
          temporary union instance:

               td = TYPEDESC()
               td.vt = VT_PTR
               td.lptdesc = POINTER(some_type)
               td.u.lptdesc = POINTER(some_type)

     It is possible to define sub-subclasses of structures, they inherit
     the fields of the base class.  If the subclass definition has a
     separate *note _fields_: 191e. variable, the fields specified in
     this are appended to the fields of the base class.

     Structure and union constructors accept both positional and keyword
     arguments.  Positional arguments are used to initialize member
     fields in the same order as they are appear in *note _fields_:
     191e.  Keyword arguments in the constructor are interpreted as
     attribute assignments, so they will initialize *note _fields_:
     191e. with the same name, or create new attributes for names not
     present in *note _fields_: 191e.

 -- Classe: ctypes.CField (*args, **kw)

     Descriptor for fields of a *note Structure: 1e5. and *note Union:
     1e6.  For example:

          >>> class Color(Structure):
          ...     _fields_ = (
          ...         ('red', c_uint8),
          ...         ('green', c_uint8),
          ...         ('blue', c_uint8),
          ...         ('intense', c_bool, 1),
          ...         ('blinking', c_bool, 1),
          ...    )
          ...
          >>> Color.red
          <ctypes.CField 'red' type=c_ubyte, ofs=0, size=1>
          >>> Color.green.type
          <class 'ctypes.c_ubyte'>
          >>> Color.blue.byte_offset
          2
          >>> Color.intense
          <ctypes.CField 'intense' type=c_bool, ofs=3, bit_size=1, bit_offset=0>
          >>> Color.blinking.bit_offset
          1

     All attributes are read-only.

     ‘CField’ objects are created via *note _fields_: 191e.; do not
     instantiate the class directly.

     Added in version 3.14: Previously, descriptors only had ‘offset’
     and ‘size’ attributes and a readable string representation; the
     ‘CField’ class was not available directly.

      -- Attributo: name

          Name of the field, as a string.

      -- Attributo: type

          Type of the field, as a *note ctypes class: 3327.

      -- Attributo: offset
      -- Attributo: byte_offset

          Offset of the field, in bytes.

          For bitfields, this is the offset of the underlying
          byte-aligned 'storage unit'; see *note bit_offset: 333a.

      -- Attributo: byte_size

          Size of the field, in bytes.

          For bitfields, this is the size of the underlying 'storage
          unit'.  Typically, it has the same size as the bitfield’s
          type.

      -- Attributo: size

          For non-bitfields, equivalent to *note byte_size: 333b.

          For bitfields, this contains a backwards-compatible bit-packed
          value that combines *note bit_size: 333d. and *note
          bit_offset: 333a.  Prefer using the explicit attributes
          instead.

      -- Attributo: is_bitfield

          True if this is a bitfield.

      -- Attributo: bit_offset
      -- Attributo: bit_size

          The location of a bitfield within its 'storage unit', that is,
          within *note byte_size: 333b. bytes of memory starting at
          *note byte_offset: 3339.

          To get the field’s value, read the storage unit as an integer,
          *note shift left: 24a5. by ‘bit_offset’ and take the
          ‘bit_size’ least significant bits.

          For non-bitfields, ‘bit_offset’ is zero and ‘bit_size’ is
          equal to ‘byte_size * 8’.

      -- Attributo: is_anonymous

          True if this field is anonymous, that is, it contains nested
          sub-fields that should be merged into a containing structure
          or union.


File: python.info,  Node: Arrays and pointers,  Next: Exceptions<9>,  Prev: Structured data types,  Up: ctypes reference

5.16.9.34 Arrays and pointers
.............................

 -- Classe: ctypes.Array (*args)

     Abstract base class for arrays.

     The recommended way to create concrete array types is by
     multiplying any *note ctypes: 2e. data type with a non-negative
     integer.  Alternatively, you can subclass this type and define
     *note _length_: 3342. and *note _type_: 3343. class variables.
     Array elements can be read and written using standard subscript and
     slice accesses; for slice reads, the resulting object is 'not'
     itself an *note Array: 1df4.

      -- Attributo: _length_

          A positive integer specifying the number of elements in the
          array.  Out-of-range subscripts result in an *note IndexError:
          173c.  Will be returned by *note len(): 841.

      -- Attributo: _type_

          Specifies the type of each element in the array.

     Array subclass constructors accept positional arguments, used to
     initialize the elements in order.

 -- Funzione: ctypes.ARRAY (type, length)

     Create an array.  Equivalent to ‘type * length’, where 'type' is a
     *note ctypes: 2e. data type and 'length' an integer.

     This function is *note soft deprecated: 23d. in favor of
     multiplication.  There are no plans to remove it.

 -- Classe: ctypes._Pointer

     Private, abstract base class for pointers.

     Concrete pointer types are created by calling *note POINTER(): 1f1.
     with the type that will be pointed to; this is done automatically
     by *note pointer(): 1a3e.

     If a pointer points to an array, its elements can be read and
     written using standard subscript and slice accesses.  Pointer
     objects have no size, so *note len(): 841. will raise *note
     TypeError: 198.  Negative subscripts will read from the memory
     'before' the pointer (as in C), and out-of-range subscripts will
     probably crash with an access violation (if you’re lucky).

      -- Attributo: _type_

          Specifies the type pointed to.

      -- Attributo: contents

          Returns the object to which to pointer points.  Assigning to
          this attribute changes the pointer to point to the assigned
          object.


File: python.info,  Node: Exceptions<9>,  Prev: Arrays and pointers,  Up: ctypes reference

5.16.9.35 Exceptions
....................

 -- Eccezione: ctypes.ArgumentError

     This exception is raised when a foreign function call cannot
     convert one of the passed arguments.

 -- Eccezione: ctypes.COMError (hresult, text, details)

     This exception is raised when a COM method call failed.

      -- Attributo: hresult

          The integer value representing the error code.

      -- Attributo: text

          The error message.

      -- Attributo: details

          The 5-tuple ‘(descr, source, helpfile, helpcontext, progid)’.

          'descr' is the textual description.  'source' is the
          language-dependent ‘ProgID’ for the class or application that
          raised the error.  'helpfile' is the path of the help file.
          'helpcontext' is the help context identifier.  'progid' is the
          ‘ProgID’ of the interface that defined the error.

     *note Availability: 2128.: Windows

     Added in version 3.14.


File: python.info,  Node: Command-line interface libraries,  Next: Concurrent Execution,  Prev: Generic Operating System Services,  Up: The Python Standard Library

5.17 Command-line interface libraries
=====================================

The modules described in this chapter assist with implementing command
line and terminal interfaces for applications.

Here’s an overview:

* Menu:

* argparse — Parser for command-line options, arguments and subcommands: argparse — Parser for command-line options arguments and subcommands.
* optparse — Parser for command line options::
* getpass — Portable password input::
* fileinput — Iterate over lines from multiple input streams::
* curses — Terminal handling for character-cell displays::
* curses.textpad — Text input widget for curses programs: curses textpad — Text input widget for curses programs.
* curses.ascii — Utilities for ASCII characters: curses ascii — Utilities for ASCII characters.
* curses.panel — A panel stack extension for curses: curses panel — A panel stack extension for curses.
* cmd — Support for line-oriented command interpreters::


File: python.info,  Node: argparse — Parser for command-line options arguments and subcommands,  Next: optparse — Parser for command line options,  Up: Command-line interface libraries

5.17.1 ‘argparse’ — Parser for command-line options, arguments and subcommands
------------------------------------------------------------------------------

Added in version 3.2.

'Source code:' Lib/argparse.py(1)

     Nota: While *note argparse: 7. is the default recommended standard
     library module for implementing basic command line applications,
     authors with more exacting requirements for exactly how their
     command line applications behave may find it doesn’t provide the
     necessary level of control.  Refer to *note Choosing an argument
     parsing library: 3351. for alternatives to consider when ‘argparse’
     doesn’t support behaviors that the application requires (such as
     entirely disabling support for interspersed options and positional
     arguments, or accepting option parameter values that start with ‘-’
     even when they correspond to another defined option).

__________________________________________________________________

Tutorial
........

This page contains the API reference information.  For a more gentle
introduction to Python command-line parsing, have a look at the *note
argparse tutorial: 3352.

The ‘argparse’ module makes it easy to write user-friendly command-line
interfaces.  The program defines what arguments it requires, and
‘argparse’ will figure out how to parse those out of *note sys.argv:
146c.  The ‘argparse’ module also automatically generates help and usage
messages.  The module will also issue errors when users give the program
invalid arguments.

The ‘argparse’ module’s support for command-line interfaces is built
around an instance of *note argparse.ArgumentParser: 1bd.  It is a
container for argument specifications and has options that apply to the
parser as whole:

     parser = argparse.ArgumentParser(
                         prog='ProgramName',
                         description='What the program does',
                         epilog='Text at the bottom of help')

The *note ArgumentParser.add_argument(): 4bd. method attaches individual
argument specifications to the parser.  It supports positional
arguments, options that accept values, and on/off flags:

     parser.add_argument('filename')           # positional argument
     parser.add_argument('-c', '--count')      # option that takes a value
     parser.add_argument('-v', '--verbose',
                         action='store_true')  # on/off flag

The *note ArgumentParser.parse_args(): 3353. method runs the parser and
places the extracted data in a *note argparse.Namespace: 3354. object:

     args = parser.parse_args()
     print(args.filename, args.count, args.verbose)

     Nota: If you’re looking for a guide about how to upgrade *note
     optparse: a4. code to ‘argparse’, see *note Upgrading Optparse
     Code: 13b6.

* Menu:

* ArgumentParser objects::
* The add_argument() method: The add_argument method.
* The parse_args() method: The parse_args method.
* Other utilities::
* Exceptions: Exceptions<10>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/argparse.py


File: python.info,  Node: ArgumentParser objects,  Next: The add_argument method,  Up: argparse — Parser for command-line options arguments and subcommands

5.17.1.1 ArgumentParser objects
...............................

 -- Classe: argparse.ArgumentParser (prog=None, usage=None,
          description=None, epilog=None, parents=[],
          formatter_class=argparse.HelpFormatter, prefix_chars='-',
          fromfile_prefix_chars=None, argument_default=None,
          conflict_handler='error', add_help=True, allow_abbrev=True,
          exit_on_error=True, *, suggest_on_error=False, color=True)

     Create a new *note ArgumentParser: 1bd. object.  All parameters
     should be passed as keyword arguments.  Each parameter has its own
     more detailed description below, but in short they are:

        * *note prog: 1bc. - The name of the program (default: generated
          from the ‘__main__’ module attributes and ‘sys.argv[0]’)

        * *note usage: 3356. - The string describing the program usage
          (default: generated from arguments added to parser)

        * *note description: 3357. - Text to display before the argument
          help (by default, no text)

        * *note epilog: 3358. - Text to display after the argument help
          (by default, no text)

        * *note parents: 3359. - A list of *note ArgumentParser: 1bd.
          objects whose arguments should also be included

        * *note formatter_class: 335a. - A class for customizing the
          help output

        * *note prefix_chars: 335b. - The set of characters that prefix
          optional arguments (default: “-“)

        * *note fromfile_prefix_chars: 335c. - The set of characters
          that prefix files from which additional arguments should be
          read (default: ‘None’)

        * *note argument_default: 335d. - The global default value for
          arguments (default: ‘None’)

        * *note conflict_handler: 335e. - The strategy for resolving
          conflicting optionals (usually unnecessary)

        * *note add_help: 335f. - Add a ‘-h/--help’ option to the parser
          (default: ‘True’)

        * *note allow_abbrev: fc1. - Allows long options to be
          abbreviated if the abbreviation is unambiguous (default:
          ‘True’)

        * *note exit_on_error: 3360. - Determines whether or not
          ‘ArgumentParser’ exits with error info when an error occurs.
          (default: ‘True’)

        * *note suggest_on_error: 3361. - Enables suggestions for
          mistyped argument choices and subparser names (default:
          ‘False’)

        * *note color: 3362. - Allow color output (default: ‘True’)

     Cambiato nella versione 3.5: 'allow_abbrev' parameter was added.

     Cambiato nella versione 3.8: In previous versions, 'allow_abbrev'
     also disabled grouping of short flags such as ‘-vv’ to mean ‘-v
     -v’.

     Cambiato nella versione 3.9: 'exit_on_error' parameter was added.

     Cambiato nella versione 3.14: 'suggest_on_error' and 'color'
     parameters were added.

The following sections describe how each of these are used.

* Menu:

* prog::
* usage::
* description::
* epilog::
* parents::
* formatter_class::
* prefix_chars::
* fromfile_prefix_chars::
* argument_default::
* allow_abbrev::
* conflict_handler::
* add_help::
* exit_on_error::
* suggest_on_error::
* color::


File: python.info,  Node: prog,  Next: usage,  Up: ArgumentParser objects

5.17.1.2 prog
.............

By default, *note ArgumentParser: 1bd. calculates the name of the
program to display in help messages depending on the way the Python
interpreter was run:

   * The *note base name: 2c2e. of ‘sys.argv[0]’ if a file was passed as
     argument.

   * The Python interpreter name followed by ‘sys.argv[0]’ if a
     directory or a zipfile was passed as argument.

   * The Python interpreter name followed by ‘-m’ followed by the module
     or package name if the *note -m: 23c. option was used.

This default is almost always desirable because it will make the help
messages match the string that was used to invoke the program on the
command line.  However, to change this default behavior, another value
can be supplied using the ‘prog=’ argument to *note ArgumentParser:
1bd.:

     >>> parser = argparse.ArgumentParser(prog='myprogram')
     >>> parser.print_help()
     usage: myprogram [-h]

     options:
      -h, --help  show this help message and exit

Note that the program name, whether determined from ‘sys.argv[0]’, from
the ‘__main__’ module attributes or from the ‘prog=’ argument, is
available to help messages using the ‘%(prog)s’ format specifier.

     >>> parser = argparse.ArgumentParser(prog='myprogram')
     >>> parser.add_argument('--foo', help='foo of the %(prog)s program')
     >>> parser.print_help()
     usage: myprogram [-h] [--foo FOO]

     options:
      -h, --help  show this help message and exit
      --foo FOO   foo of the myprogram program

Cambiato nella versione 3.14: The default ‘prog’ value now reflects how
‘__main__’ was actually executed, rather than always being
‘os.path.basename(sys.argv[0])’.


File: python.info,  Node: usage,  Next: description,  Prev: prog,  Up: ArgumentParser objects

5.17.1.3 usage
..............

By default, *note ArgumentParser: 1bd. calculates the usage message from
the arguments it contains.  The default message can be overridden with
the ‘usage=’ keyword argument:

     >>> parser = argparse.ArgumentParser(prog='PROG', usage='%(prog)s [options]')
     >>> parser.add_argument('--foo', nargs='?', help='foo help')
     >>> parser.add_argument('bar', nargs='+', help='bar help')
     >>> parser.print_help()
     usage: PROG [options]

     positional arguments:
      bar          bar help

     options:
      -h, --help   show this help message and exit
      --foo [FOO]  foo help

The ‘%(prog)s’ format specifier is available to fill in the program name
in your usage messages.

When a custom usage message is specified for the main parser, you may
also want to consider passing the ‘prog’ argument to *note
add_subparsers(): e13. or the ‘prog’ and the ‘usage’ arguments to
‘add_parser()’, to ensure consistent command prefixes and usage
information across subparsers.


File: python.info,  Node: description,  Next: epilog,  Prev: usage,  Up: ArgumentParser objects

5.17.1.4 description
....................

Most calls to the *note ArgumentParser: 1bd. constructor will use the
‘description=’ keyword argument.  This argument gives a brief
description of what the program does and how it works.  In help
messages, the description is displayed between the command-line usage
string and the help messages for the various arguments.

By default, the description will be line-wrapped so that it fits within
the given space.  To change this behavior, see the *note
formatter_class: 335a. argument.


File: python.info,  Node: epilog,  Next: parents,  Prev: description,  Up: ArgumentParser objects

5.17.1.5 epilog
...............

Some programs like to display additional description of the program
after the description of the arguments.  Such text can be specified
using the ‘epilog=’ argument to *note ArgumentParser: 1bd.:

     >>> parser = argparse.ArgumentParser(
     ...     description='A foo that bars',
     ...     epilog="And that's how you'd foo a bar")
     >>> parser.print_help()
     usage: argparse.py [-h]

     A foo that bars

     options:
      -h, --help  show this help message and exit

     And that's how you'd foo a bar

As with the *note description: 3357. argument, the ‘epilog=’ text is by
default line-wrapped, but this behavior can be adjusted with the *note
formatter_class: 335a. argument to *note ArgumentParser: 1bd.


File: python.info,  Node: parents,  Next: formatter_class,  Prev: epilog,  Up: ArgumentParser objects

5.17.1.6 parents
................

Sometimes, several parsers share a common set of arguments.  Rather than
repeating the definitions of these arguments, a single parser with all
the shared arguments and passed to ‘parents=’ argument to *note
ArgumentParser: 1bd. can be used.  The ‘parents=’ argument takes a list
of *note ArgumentParser: 1bd. objects, collects all the positional and
optional actions from them, and adds these actions to the *note
ArgumentParser: 1bd. object being constructed:

     >>> parent_parser = argparse.ArgumentParser(add_help=False)
     >>> parent_parser.add_argument('--parent', type=int)

     >>> foo_parser = argparse.ArgumentParser(parents=[parent_parser])
     >>> foo_parser.add_argument('foo')
     >>> foo_parser.parse_args(['--parent', '2', 'XXX'])
     Namespace(foo='XXX', parent=2)

     >>> bar_parser = argparse.ArgumentParser(parents=[parent_parser])
     >>> bar_parser.add_argument('--bar')
     >>> bar_parser.parse_args(['--bar', 'YYY'])
     Namespace(bar='YYY', parent=None)

Note that most parent parsers will specify ‘add_help=False’.  Otherwise,
the *note ArgumentParser: 1bd. will see two ‘-h/--help’ options (one in
the parent and one in the child) and raise an error.

     Nota: You must fully initialize the parsers before passing them via
     ‘parents=’.  If you change the parent parsers after the child
     parser, those changes will not be reflected in the child.


File: python.info,  Node: formatter_class,  Next: prefix_chars,  Prev: parents,  Up: ArgumentParser objects

5.17.1.7 formatter_class
........................

*note ArgumentParser: 1bd. objects allow the help formatting to be
customized by specifying an alternate formatting class.  Currently,
there are four such classes:

 -- Classe: argparse.RawDescriptionHelpFormatter
 -- Classe: argparse.RawTextHelpFormatter
 -- Classe: argparse.ArgumentDefaultsHelpFormatter
 -- Classe: argparse.MetavarTypeHelpFormatter

*note RawDescriptionHelpFormatter: 3366. and *note RawTextHelpFormatter:
3367. give more control over how textual descriptions are displayed.  By
default, *note ArgumentParser: 1bd. objects line-wrap the *note
description: 3357. and *note epilog: 3358. texts in command-line help
messages:

     >>> parser = argparse.ArgumentParser(
     ...     prog='PROG',
     ...     description='''this description
     ...         was indented weird
     ...             but that is okay''',
     ...     epilog='''
     ...             likewise for this epilog whose whitespace will
     ...         be cleaned up and whose words will be wrapped
     ...         across a couple lines''')
     >>> parser.print_help()
     usage: PROG [-h]

     this description was indented weird but that is okay

     options:
      -h, --help  show this help message and exit

     likewise for this epilog whose whitespace will be cleaned up and whose words
     will be wrapped across a couple lines

Passing *note RawDescriptionHelpFormatter: 3366. as ‘formatter_class=’
indicates that *note description: 3357. and *note epilog: 3358. are
already correctly formatted and should not be line-wrapped:

     >>> parser = argparse.ArgumentParser(
     ...     prog='PROG',
     ...     formatter_class=argparse.RawDescriptionHelpFormatter,
     ...     description=textwrap.dedent('''\
     ...         Please do not mess up this text!
     ...         --------------------------------
     ...             I have indented it
     ...             exactly the way
     ...             I want it
     ...         '''))
     >>> parser.print_help()
     usage: PROG [-h]

     Please do not mess up this text!
     --------------------------------
        I have indented it
        exactly the way
        I want it

     options:
      -h, --help  show this help message and exit

*note RawTextHelpFormatter: 3367. maintains whitespace for all sorts of
help text, including argument descriptions.  However, multiple newlines
are replaced with one.  If you wish to preserve multiple blank lines,
add spaces between the newlines.

*note ArgumentDefaultsHelpFormatter: 1c38. automatically adds
information about default values to each of the argument help messages:

     >>> parser = argparse.ArgumentParser(
     ...     prog='PROG',
     ...     formatter_class=argparse.ArgumentDefaultsHelpFormatter)
     >>> parser.add_argument('--foo', type=int, default=42, help='FOO!')
     >>> parser.add_argument('bar', nargs='*', default=[1, 2, 3], help='BAR!')
     >>> parser.print_help()
     usage: PROG [-h] [--foo FOO] [bar ...]

     positional arguments:
      bar         BAR! (default: [1, 2, 3])

     options:
      -h, --help  show this help message and exit
      --foo FOO   FOO! (default: 42)

*note MetavarTypeHelpFormatter: 3368. uses the name of the *note type:
3369. argument for each argument as the display name for its values
(rather than using the *note dest: 336a. as the regular formatter does):

     >>> parser = argparse.ArgumentParser(
     ...     prog='PROG',
     ...     formatter_class=argparse.MetavarTypeHelpFormatter)
     >>> parser.add_argument('--foo', type=int)
     >>> parser.add_argument('bar', type=float)
     >>> parser.print_help()
     usage: PROG [-h] [--foo int] float

     positional arguments:
       float

     options:
       -h, --help  show this help message and exit
       --foo int


File: python.info,  Node: prefix_chars,  Next: fromfile_prefix_chars,  Prev: formatter_class,  Up: ArgumentParser objects

5.17.1.8 prefix_chars
.....................

Most command-line options will use ‘-’ as the prefix, e.g.  ‘-f/--foo’.
Parsers that need to support different or additional prefix characters,
e.g.  for options like ‘+f’ or ‘/foo’, may specify them using the
‘prefix_chars=’ argument to the *note ArgumentParser: 1bd. constructor:

     >>> parser = argparse.ArgumentParser(prog='PROG', prefix_chars='-+')
     >>> parser.add_argument('+f')
     >>> parser.add_argument('++bar')
     >>> parser.parse_args('+f X ++bar Y'.split())
     Namespace(bar='Y', f='X')

The ‘prefix_chars=’ argument defaults to ‘'-'’.  Supplying a set of
characters that does not include ‘-’ will cause ‘-f/--foo’ options to be
disallowed.


File: python.info,  Node: fromfile_prefix_chars,  Next: argument_default,  Prev: prefix_chars,  Up: ArgumentParser objects

5.17.1.9 fromfile_prefix_chars
..............................

Sometimes, when dealing with a particularly long argument list, it may
make sense to keep the list of arguments in a file rather than typing it
out at the command line.  If the ‘fromfile_prefix_chars=’ argument is
given to the *note ArgumentParser: 1bd. constructor, then arguments that
start with any of the specified characters will be treated as files, and
will be replaced by the arguments they contain.  For example:

     >>> with open('args.txt', 'w', encoding=sys.getfilesystemencoding()) as fp:
     ...     fp.write('-f\nbar')
     ...
     >>> parser = argparse.ArgumentParser(fromfile_prefix_chars='@')
     >>> parser.add_argument('-f')
     >>> parser.parse_args(['-f', 'foo', '@args.txt'])
     Namespace(f='bar')

Arguments read from a file must be one per line by default (but see also
*note convert_arg_line_to_args(): 336b.) and are treated as if they were
in the same place as the original file referencing argument on the
command line.  So in the example above, the expression ‘['-f', 'foo',
'@args.txt']’ is considered equivalent to the expression ‘['-f', 'foo',
'-f', 'bar']’.

     Nota: Empty lines are treated as empty strings (‘''’), which are
     allowed as values but not as arguments.  Empty lines that are read
     as arguments will result in an «unrecognized arguments» error.

*note ArgumentParser: 1bd. uses *note filesystem encoding and error
handler: 75e. to read the file containing arguments.

The ‘fromfile_prefix_chars=’ argument defaults to ‘None’, meaning that
arguments will never be treated as file references.

Cambiato nella versione 3.12: *note ArgumentParser: 1bd. changed
encoding and errors to read arguments files from default (e.g.  *note
locale.getpreferredencoding(False): 75d. and ‘"strict"’) to the *note
filesystem encoding and error handler: 75e.  Arguments file should be
encoded in UTF-8 instead of ANSI Codepage on Windows.


File: python.info,  Node: argument_default,  Next: allow_abbrev,  Prev: fromfile_prefix_chars,  Up: ArgumentParser objects

5.17.1.10 argument_default
..........................

Generally, argument defaults are specified either by passing a default
to *note add_argument(): 4bd. or by calling the *note set_defaults():
336c. methods with a specific set of name-value pairs.  Sometimes
however, it may be useful to specify a single parser-wide default for
arguments.  This can be accomplished by passing the ‘argument_default=’
keyword argument to *note ArgumentParser: 1bd.  For example, to globally
suppress attribute creation on *note parse_args(): 3353. calls, we
supply ‘argument_default=SUPPRESS’:

     >>> parser = argparse.ArgumentParser(argument_default=argparse.SUPPRESS)
     >>> parser.add_argument('--foo')
     >>> parser.add_argument('bar', nargs='?')
     >>> parser.parse_args(['--foo', '1', 'BAR'])
     Namespace(bar='BAR', foo='1')
     >>> parser.parse_args([])
     Namespace()


File: python.info,  Node: allow_abbrev,  Next: conflict_handler,  Prev: argument_default,  Up: ArgumentParser objects

5.17.1.11 allow_abbrev
......................

Normally, when you pass an argument list to the *note parse_args():
3353. method of an *note ArgumentParser: 1bd, it *note recognizes
abbreviations: fc0. of long options.

This feature can be disabled by setting ‘allow_abbrev’ to ‘False’:

     >>> parser = argparse.ArgumentParser(prog='PROG', allow_abbrev=False)
     >>> parser.add_argument('--foobar', action='store_true')
     >>> parser.add_argument('--foonley', action='store_false')
     >>> parser.parse_args(['--foon'])
     usage: PROG [-h] [--foobar] [--foonley]
     PROG: error: unrecognized arguments: --foon

Added in version 3.5.


File: python.info,  Node: conflict_handler,  Next: add_help,  Prev: allow_abbrev,  Up: ArgumentParser objects

5.17.1.12 conflict_handler
..........................

*note ArgumentParser: 1bd. objects do not allow two actions with the
same option string.  By default, *note ArgumentParser: 1bd. objects
raise an exception if an attempt is made to create an argument with an
option string that is already in use:

     >>> parser = argparse.ArgumentParser(prog='PROG')
     >>> parser.add_argument('-f', '--foo', help='old foo help')
     >>> parser.add_argument('--foo', help='new foo help')
     Traceback (most recent call last):
      ..
     ArgumentError: argument --foo: conflicting option string(s): --foo

Sometimes (e.g.  when using *note parents: 3359.) it may be useful to
simply override any older arguments with the same option string.  To get
this behavior, the value ‘'resolve'’ can be supplied to the
‘conflict_handler=’ argument of *note ArgumentParser: 1bd.:

     >>> parser = argparse.ArgumentParser(prog='PROG', conflict_handler='resolve')
     >>> parser.add_argument('-f', '--foo', help='old foo help')
     >>> parser.add_argument('--foo', help='new foo help')
     >>> parser.print_help()
     usage: PROG [-h] [-f FOO] [--foo FOO]

     options:
      -h, --help  show this help message and exit
      -f FOO      old foo help
      --foo FOO   new foo help

Note that *note ArgumentParser: 1bd. objects only remove an action if
all of its option strings are overridden.  So, in the example above, the
old ‘-f/--foo’ action is retained as the ‘-f’ action, because only the
‘--foo’ option string was overridden.


File: python.info,  Node: add_help,  Next: exit_on_error,  Prev: conflict_handler,  Up: ArgumentParser objects

5.17.1.13 add_help
..................

By default, *note ArgumentParser: 1bd. objects add an option which
simply displays the parser’s help message.  If ‘-h’ or ‘--help’ is
supplied at the command line, the ‘ArgumentParser’ help will be printed.

Occasionally, it may be useful to disable the addition of this help
option.  This can be achieved by passing ‘False’ as the ‘add_help=’
argument to *note ArgumentParser: 1bd.:

     >>> parser = argparse.ArgumentParser(prog='PROG', add_help=False)
     >>> parser.add_argument('--foo', help='foo help')
     >>> parser.print_help()
     usage: PROG [--foo FOO]

     options:
      --foo FOO  foo help

The help option is typically ‘-h/--help’.  The exception to this is if
the ‘prefix_chars=’ is specified and does not include ‘-’, in which case
‘-h’ and ‘--help’ are not valid options.  In this case, the first
character in ‘prefix_chars’ is used to prefix the help options:

     >>> parser = argparse.ArgumentParser(prog='PROG', prefix_chars='+/')
     >>> parser.print_help()
     usage: PROG [+h]

     options:
       +h, ++help  show this help message and exit


File: python.info,  Node: exit_on_error,  Next: suggest_on_error,  Prev: add_help,  Up: ArgumentParser objects

5.17.1.14 exit_on_error
.......................

Normally, when you pass an invalid argument list to the *note
parse_args(): 3353. method of an *note ArgumentParser: 1bd, it will
print a 'message' to *note sys.stderr: b35. and exit with a status code
of 2.

If the user would like to catch errors manually, the feature can be
enabled by setting ‘exit_on_error’ to ‘False’:

     >>> parser = argparse.ArgumentParser(exit_on_error=False)
     >>> parser.add_argument('--integers', type=int)
     _StoreAction(option_strings=['--integers'], dest='integers', nargs=None, const=None, default=None, type=<class 'int'>, choices=None, help=None, metavar=None)
     >>> try:
     ...     parser.parse_args('--integers a'.split())
     ... except argparse.ArgumentError:
     ...     print('Catching an argumentError')
     ...
     Catching an argumentError

Added in version 3.9.


File: python.info,  Node: suggest_on_error,  Next: color,  Prev: exit_on_error,  Up: ArgumentParser objects

5.17.1.15 suggest_on_error
..........................

By default, when a user passes an invalid argument choice or subparser
name, *note ArgumentParser: 1bd. will exit with error info and list the
permissible argument choices (if specified) or subparser names as part
of the error message.

If the user would like to enable suggestions for mistyped argument
choices and subparser names, the feature can be enabled by setting
‘suggest_on_error’ to ‘True’.  Note that this only applies for arguments
when the choices specified are strings:

     >>> parser = argparse.ArgumentParser(description='Process some integers.',
                                          suggest_on_error=True)
     >>> parser.add_argument('--action', choices=['sum', 'max'])
     >>> parser.add_argument('integers', metavar='N', type=int, nargs='+',
     ...                     help='an integer for the accumulator')
     >>> parser.parse_args(['--action', 'sumn', 1, 2, 3])
     tester.py: error: argument --action: invalid choice: 'sumn', maybe you meant 'sum'? (choose from 'sum', 'max')

If you’re writing code that needs to be compatible with older Python
versions and want to opportunistically use ‘suggest_on_error’ when it’s
available, you can set it as an attribute after initializing the parser
instead of using the keyword argument:

     >>> parser = argparse.ArgumentParser(description='Process some integers.')
     >>> parser.suggest_on_error = True

Added in version 3.14.


File: python.info,  Node: color,  Prev: suggest_on_error,  Up: ArgumentParser objects

5.17.1.16 color
...............

By default, the help message is printed in color using ANSI escape
sequences(1).  If you want plain text help messages, you can disable
this *note in your local environment: 1b7, or in the argument parser
itself by setting ‘color’ to ‘False’:

     >>> parser = argparse.ArgumentParser(description='Process some integers.',
     ...                                  color=False)
     >>> parser.add_argument('--action', choices=['sum', 'max'])
     >>> parser.add_argument('integers', metavar='N', type=int, nargs='+',
     ...                     help='an integer for the accumulator')
     >>> parser.parse_args(['--help'])

Note that when ‘color=True’, colored output depends on both environment
variables and terminal capabilities.  However, if ‘color=False’, colored
output is always disabled, even if environment variables like
‘FORCE_COLOR’ are set.

     Nota: Error messages will include color codes when redirecting
     stderr to a file.  To avoid this, set the NO_COLOR(2) or *note
     PYTHON_COLORS: 476. environment variable (for example, ‘NO_COLOR=1
     python script.py 2> errors.txt’).

Added in version 3.14.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/ANSI_escape_code

   (2) https://no-color.org/


File: python.info,  Node: The add_argument method,  Next: The parse_args method,  Prev: ArgumentParser objects,  Up: argparse — Parser for command-line options arguments and subcommands

5.17.1.17 The add_argument() method
...................................

 -- Metodo: ArgumentParser.add_argument (name or flags..., *[, action][,
          nargs][, const][, default][, type][, choices][, required][,
          help][, metavar][, dest][, deprecated])

     Define how a single command-line argument should be parsed.  Each
     parameter has its own more detailed description below, but in short
     they are:

        * *note name or flags: 336f. - Either a name or a list of option
          strings, e.g.  ‘'foo'’ or ‘'-f', '--foo'’.

        * *note action: 1913. - The basic type of action to be taken
          when this argument is encountered at the command line.

        * *note nargs: 1919. - The number of command-line arguments that
          should be consumed.

        * *note const: 191b. - A constant value required by some *note
          action: 1913. and *note nargs: 1919. selections.

        * *note default: 191a. - The value produced if the argument is
          absent from the command line and if it is absent from the
          namespace object.

        * *note type: 3369. - The type to which the command-line
          argument should be converted.

        * *note choices: 1915. - A sequence of the allowable values for
          the argument.

        * *note required: 3370. - Whether or not the command-line option
          may be omitted (optionals only).

        * *note help: 3371. - A brief description of what the argument
          does.

        * *note metavar: 3372. - A name for the argument in usage
          messages.

        * *note dest: 336a. - The name of the attribute to be added to
          the object returned by *note parse_args(): 3353.

        * *note deprecated: 3373. - Whether or not use of the argument
          is deprecated.

The following sections describe how each of these are used.

* Menu:

* name or flags::
* action::
* nargs::
* const::
* default::
* type::
* choices::
* required::
* help::
* metavar::
* dest::
* deprecated::
* Action classes::


File: python.info,  Node: name or flags,  Next: action,  Up: The add_argument method

5.17.1.18 name or flags
.......................

The *note add_argument(): 4bd. method must know whether an optional
argument, like ‘-f’ or ‘--foo’, or a positional argument, like a list of
filenames, is expected.  The first arguments passed to *note
add_argument(): 4bd. must therefore be either a series of flags, or a
simple argument name.

For example, an optional argument could be created like:

     >>> parser.add_argument('-f', '--foo')

while a positional argument could be created like:

     >>> parser.add_argument('bar')

When *note parse_args(): 3353. is called, optional arguments will be
identified by the ‘-’ prefix, and the remaining arguments will be
assumed to be positional:

     >>> parser = argparse.ArgumentParser(prog='PROG')
     >>> parser.add_argument('-f', '--foo')
     >>> parser.add_argument('bar')
     >>> parser.parse_args(['BAR'])
     Namespace(bar='BAR', foo=None)
     >>> parser.parse_args(['BAR', '--foo', 'FOO'])
     Namespace(bar='BAR', foo='FOO')
     >>> parser.parse_args(['--foo', 'FOO'])
     usage: PROG [-h] [-f FOO] bar
     PROG: error: the following arguments are required: bar

By default, ‘argparse’ automatically handles the internal naming and
display names of arguments, simplifying the process without requiring
additional configuration.  As such, you do not need to specify the *note
dest: 336a. and *note metavar: 3372. parameters.  The *note dest: 336a.
parameter defaults to the argument name with underscores ‘_’ replacing
hyphens ‘-’ .  The *note metavar: 3372. parameter defaults to the
upper-cased name.  For example:

     >>> parser = argparse.ArgumentParser(prog='PROG')
     >>> parser.add_argument('--foo-bar')
     >>> parser.parse_args(['--foo-bar', 'FOO-BAR'])
     Namespace(foo_bar='FOO-BAR')
     >>> parser.print_help()
     usage:  [-h] [--foo-bar FOO-BAR]

     optional arguments:
      -h, --help  show this help message and exit
      --foo-bar FOO-BAR


File: python.info,  Node: action,  Next: nargs,  Prev: name or flags,  Up: The add_argument method

5.17.1.19 action
................

*note ArgumentParser: 1bd. objects associate command-line arguments with
actions.  These actions can do just about anything with the command-line
arguments associated with them, though most actions simply add an
attribute to the object returned by *note parse_args(): 3353.  The
‘action’ keyword argument specifies how the command-line arguments
should be handled.  The supplied actions are:

   * ‘'store'’ - This just stores the argument’s value.  This is the
     default action.

   * ‘'store_const'’ - This stores the value specified by the *note
     const: 191b. keyword argument; note that the *note const: 191b.
     keyword argument defaults to ‘None’.  The ‘'store_const'’ action is
     most commonly used with optional arguments that specify some sort
     of flag.  For example:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo', action='store_const', const=42)
          >>> parser.parse_args(['--foo'])
          Namespace(foo=42)

   * ‘'store_true'’ and ‘'store_false'’ - These are special cases of
     ‘'store_const'’ that respectively store the values ‘True’ and
     ‘False’ with default values of ‘False’ and ‘True’:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo', action='store_true')
          >>> parser.add_argument('--bar', action='store_false')
          >>> parser.add_argument('--baz', action='store_false')
          >>> parser.parse_args('--foo --bar'.split())
          Namespace(foo=True, bar=False, baz=True)

   * ‘'append'’ - This appends each argument value to a list.  It is
     useful for allowing an option to be specified multiple times.  If
     the default value is a non-empty list, the parsed value will start
     with the default list’s elements and any values from the command
     line will be appended after those default values.  Example usage:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo', action='append', default=['0'])
          >>> parser.parse_args('--foo 1 --foo 2'.split())
          Namespace(foo=['0', '1', '2'])

   * ‘'append_const'’ - This appends the value specified by the *note
     const: 191b. keyword argument to a list; note that the *note const:
     191b. keyword argument defaults to ‘None’.  The ‘'append_const'’
     action is typically useful when multiple arguments need to store
     constants to the same list.  For example:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--str', dest='types', action='append_const', const=str)
          >>> parser.add_argument('--int', dest='types', action='append_const', const=int)
          >>> parser.parse_args('--str --int'.split())
          Namespace(types=[<class 'str'>, <class 'int'>])

   * ‘'extend'’ - This appends each item from a multi-value argument to
     a list.  The ‘'extend'’ action is typically used with the *note
     nargs: 1919. keyword argument value ‘'+'’ or ‘'*'’.  Note that when
     *note nargs: 1919. is ‘None’ (the default) or ‘'?'’, each character
     of the argument string will be appended to the list.  Example
     usage:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument("--foo", action="extend", nargs="+", type=str)
          >>> parser.parse_args(["--foo", "f1", "--foo", "f2", "f3", "f4"])
          Namespace(foo=['f1', 'f2', 'f3', 'f4'])

     Added in version 3.8.

   * ‘'count'’ - This counts the number of times an argument occurs.
     For example, this is useful for increasing verbosity levels:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--verbose', '-v', action='count', default=0)
          >>> parser.parse_args(['-vvv'])
          Namespace(verbose=3)

     Note, the 'default' will be ‘None’ unless explicitly set to '0'.

   * ‘'help'’ - This prints a complete help message for all the options
     in the current parser and then exits.  By default a help action is
     automatically added to the parser.  See *note ArgumentParser: 1bd.
     for details of how the output is created.

   * ‘'version'’ - This expects a ‘version=’ keyword argument in the
     *note add_argument(): 4bd. call, and prints version information and
     exits when invoked:

          >>> import argparse
          >>> parser = argparse.ArgumentParser(prog='PROG')
          >>> parser.add_argument('--version', action='version', version='%(prog)s 2.0')
          >>> parser.parse_args(['--version'])
          PROG 2.0

You may also specify an arbitrary action by passing an *note Action:
1b74. subclass (e.g.  *note BooleanOptionalAction: 1bda.) or other
object that implements the same interface.  Only actions that consume
command-line arguments (e.g.  ‘'store'’, ‘'append'’, ‘'extend'’, or
custom actions with non-zero ‘nargs’) can be used with positional
arguments.

The recommended way to create a custom action is to extend *note Action:
1b74, overriding the ‘__call__()’ method and optionally the ‘__init__()’
and ‘format_usage()’ methods.  You can also register custom actions
using the *note register(): 3376. method and reference them by their
registered name.

An example of a custom action:

     >>> class FooAction(argparse.Action):
     ...     def __init__(self, option_strings, dest, nargs=None, **kwargs):
     ...         if nargs is not None:
     ...             raise ValueError("nargs not allowed")
     ...         super().__init__(option_strings, dest, **kwargs)
     ...     def __call__(self, parser, namespace, values, option_string=None):
     ...         print('%r %r %r' % (namespace, values, option_string))
     ...         setattr(namespace, self.dest, values)
     ...
     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('--foo', action=FooAction)
     >>> parser.add_argument('bar', action=FooAction)
     >>> args = parser.parse_args('1 --foo 2'.split())
     Namespace(bar=None, foo=None) '1' None
     Namespace(bar='1', foo=None) '2' '--foo'
     >>> args
     Namespace(bar='1', foo='2')

For more details, see *note Action: 1b74.


File: python.info,  Node: nargs,  Next: const,  Prev: action,  Up: The add_argument method

5.17.1.20 nargs
...............

*note ArgumentParser: 1bd. objects usually associate a single
command-line argument with a single action to be taken.  The ‘nargs’
keyword argument associates a different number of command-line arguments
with a single action.  See also *note Specifying ambiguous arguments:
3378.  The supported values are:

   * ‘N’ (an integer).  ‘N’ arguments from the command line will be
     gathered together into a list.  For example:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo', nargs=2)
          >>> parser.add_argument('bar', nargs=1)
          >>> parser.parse_args('c --foo a b'.split())
          Namespace(bar=['c'], foo=['a', 'b'])

     Note that ‘nargs=1’ produces a list of one item.  This is different
     from the default, in which the item is produced by itself.

   * ‘'?'’.  One argument will be consumed from the command line if
     possible, and produced as a single item.  If no command-line
     argument is present, the value from *note default: 191a. will be
     produced.  Note that for optional arguments, there is an additional
     case - the option string is present but not followed by a
     command-line argument.  In this case the value from *note const:
     191b. will be produced.  Some examples to illustrate this:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo', nargs='?', const='c', default='d')
          >>> parser.add_argument('bar', nargs='?', default='d')
          >>> parser.parse_args(['XX', '--foo', 'YY'])
          Namespace(bar='XX', foo='YY')
          >>> parser.parse_args(['XX', '--foo'])
          Namespace(bar='XX', foo='c')
          >>> parser.parse_args([])
          Namespace(bar='d', foo='d')

     One of the more common uses of ‘nargs='?'’ is to allow optional
     input and output files:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('infile', nargs='?')
          >>> parser.add_argument('outfile', nargs='?')
          >>> parser.parse_args(['input.txt', 'output.txt'])
          Namespace(infile='input.txt', outfile='output.txt')
          >>> parser.parse_args(['input.txt'])
          Namespace(infile='input.txt', outfile=None)
          >>> parser.parse_args([])
          Namespace(infile=None, outfile=None)

   * ‘'*'’.  All command-line arguments present are gathered into a
     list.  Note that it generally doesn’t make much sense to have more
     than one positional argument with ‘nargs='*'’, but multiple
     optional arguments with ‘nargs='*'’ is possible.  For example:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo', nargs='*')
          >>> parser.add_argument('--bar', nargs='*')
          >>> parser.add_argument('baz', nargs='*')
          >>> parser.parse_args('a b --foo x y --bar 1 2'.split())
          Namespace(bar=['1', '2'], baz=['a', 'b'], foo=['x', 'y'])

   * ‘'+'’.  Just like ‘'*'’, all command-line arguments present are
     gathered into a list.  Additionally, an error message will be
     generated if there wasn’t at least one command-line argument
     present.  For example:

          >>> parser = argparse.ArgumentParser(prog='PROG')
          >>> parser.add_argument('foo', nargs='+')
          >>> parser.parse_args(['a', 'b'])
          Namespace(foo=['a', 'b'])
          >>> parser.parse_args([])
          usage: PROG [-h] foo [foo ...]
          PROG: error: the following arguments are required: foo

If the ‘nargs’ keyword argument is not provided, the number of arguments
consumed is determined by the *note action: 1913.  Generally this means
a single command-line argument will be consumed and a single item (not a
list) will be produced.  Actions that do not consume command-line
arguments (e.g.  ‘'store_const'’) set ‘nargs=0’.


File: python.info,  Node: const,  Next: default,  Prev: nargs,  Up: The add_argument method

5.17.1.21 const
...............

The ‘const’ argument of *note add_argument(): 4bd. is used to hold
constant values that are not read from the command line but are required
for the various *note ArgumentParser: 1bd. actions.  The two most common
uses of it are:

   * When *note add_argument(): 4bd. is called with
     ‘action='store_const'’ or ‘action='append_const'’.  These actions
     add the ‘const’ value to one of the attributes of the object
     returned by *note parse_args(): 3353.  See the *note action: 1913.
     description for examples.  If ‘const’ is not provided to *note
     add_argument(): 4bd, it will receive a default value of ‘None’.

   * When *note add_argument(): 4bd. is called with option strings (like
     ‘-f’ or ‘--foo’) and ‘nargs='?'’.  This creates an optional
     argument that can be followed by zero or one command-line
     arguments.  When parsing the command line, if the option string is
     encountered with no command-line argument following it, the value
     from ‘const’ will be used.  See the *note nargs: 1919. description
     for examples.

Cambiato nella versione 3.11: ‘const=None’ by default, including when
‘action='append_const'’ or ‘action='store_const'’.


File: python.info,  Node: default,  Next: type,  Prev: const,  Up: The add_argument method

5.17.1.22 default
.................

All optional arguments and some positional arguments may be omitted at
the command line.  The ‘default’ keyword argument of *note
add_argument(): 4bd, whose value defaults to ‘None’, specifies what
value should be used if the command-line argument is not present.  For
optional arguments, the ‘default’ value is used when the option string
was not present at the command line:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('--foo', default=42)
     >>> parser.parse_args(['--foo', '2'])
     Namespace(foo='2')
     >>> parser.parse_args([])
     Namespace(foo=42)

If the target namespace already has an attribute set, the action
'default' will not overwrite it:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('--foo', default=42)
     >>> parser.parse_args([], namespace=argparse.Namespace(foo=101))
     Namespace(foo=101)

If the ‘default’ value is a string, the parser parses the value as if it
were a command-line argument.  In particular, the parser applies any
*note type: 3369. conversion argument, if provided, before setting the
attribute on the *note Namespace: 3354. return value.  Otherwise, the
parser uses the value as is:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('--length', default='10', type=int)
     >>> parser.add_argument('--width', default=10.5, type=int)
     >>> parser.parse_args()
     Namespace(length=10, width=10.5)

For positional arguments with *note nargs: 1919. equal to ‘?’ or ‘*’,
the ‘default’ value is used when no command-line argument was present:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('foo', nargs='?', default=42)
     >>> parser.parse_args(['a'])
     Namespace(foo='a')
     >>> parser.parse_args([])
     Namespace(foo=42)

For *note required: 3370. arguments, the ‘default’ value is ignored.
For example, this applies to positional arguments with *note nargs:
1919. values other than ‘?’ or ‘*’, or optional arguments marked as
‘required=True’.

Providing ‘default=argparse.SUPPRESS’ causes no attribute to be added if
the command-line argument was not present:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('--foo', default=argparse.SUPPRESS)
     >>> parser.parse_args([])
     Namespace()
     >>> parser.parse_args(['--foo', '1'])
     Namespace(foo='1')


File: python.info,  Node: type,  Next: choices,  Prev: default,  Up: The add_argument method

5.17.1.23 type
..............

By default, the parser reads command-line arguments in as simple
strings.  However, quite often the command-line string should instead be
interpreted as another type, such as a *note float: 196. or *note int:
19b.  The ‘type’ keyword for *note add_argument(): 4bd. allows any
necessary type-checking and type conversions to be performed.

If the *note type: 3369. keyword is used with the *note default: 191a.
keyword, the type converter is only applied if the default is a string.

The argument to ‘type’ can be a callable that accepts a single string or
the name of a registered type (see *note register(): 3376.) If the
function raises *note ArgumentTypeError: 337c, *note TypeError: 198, or
*note ValueError: 2ec, the exception is caught and a nicely formatted
error message is displayed.  Other exception types are not handled.

Common built-in types and functions can be used as type converters:

     import argparse
     import pathlib

     parser = argparse.ArgumentParser()
     parser.add_argument('count', type=int)
     parser.add_argument('distance', type=float)
     parser.add_argument('street', type=ascii)
     parser.add_argument('code_point', type=ord)
     parser.add_argument('datapath', type=pathlib.Path)

User defined functions can be used as well:

     >>> def hyphenated(string):
     ...     return '-'.join([word[:4] for word in string.casefold().split()])
     ...
     >>> parser = argparse.ArgumentParser()
     >>> _ = parser.add_argument('short_title', type=hyphenated)
     >>> parser.parse_args(['"The Tale of Two Cities"'])
     Namespace(short_title='"the-tale-of-two-citi')

The *note bool(): 3c3. function is not recommended as a type converter.
All it does is convert empty strings to ‘False’ and non-empty strings to
‘True’.  This is usually not what is desired.

In general, the ‘type’ keyword is a convenience that should only be used
for simple conversions that can only raise one of the three supported
exceptions.  Anything with more interesting error-handling or resource
management should be done downstream after the arguments are parsed.

For example, JSON or YAML conversions have complex error cases that
require better reporting than can be given by the ‘type’ keyword.  A
*note JSONDecodeError: 1024. would not be well formatted and a *note
FileNotFoundError: 264. exception would not be handled at all.

Even *note FileType: 30c. has its limitations for use with the ‘type’
keyword.  If one argument uses *note FileType: 30c. and then a
subsequent argument fails, an error is reported but the file is not
automatically closed.  In this case, it would be better to wait until
after the parser has run and then use the *note with: 186.-statement to
manage the files.

For type checkers that simply check against a fixed set of values,
consider using the *note choices: 1915. keyword instead.


File: python.info,  Node: choices,  Next: required,  Prev: type,  Up: The add_argument method

5.17.1.24 choices
.................

Some command-line arguments should be selected from a restricted set of
values.  These can be handled by passing a sequence object as the
'choices' keyword argument to *note add_argument(): 4bd.  When the
command line is parsed, argument values will be checked, and an error
message will be displayed if the argument was not one of the acceptable
values:

     >>> parser = argparse.ArgumentParser(prog='game.py')
     >>> parser.add_argument('move', choices=['rock', 'paper', 'scissors'])
     >>> parser.parse_args(['rock'])
     Namespace(move='rock')
     >>> parser.parse_args(['fire'])
     usage: game.py [-h] {rock,paper,scissors}
     game.py: error: argument move: invalid choice: 'fire' (choose from 'rock',
     'paper', 'scissors')

Any sequence can be passed as the 'choices' value, so *note list: 24d.
objects, *note tuple: 614. objects, and custom sequences are all
supported.

Use of *note enum.Enum: 843. is not recommended because it is difficult
to control its appearance in usage, help, and error messages.

Note that 'choices' are checked after any *note type: 3369. conversions
have been performed, so objects in 'choices' should match the *note
type: 3369. specified.  This can make 'choices' appear unfamiliar in
usage, help, or error messages.

To keep 'choices' user-friendly, consider a custom type wrapper that
converts and formats values, or omit *note type: 3369. and handle
conversion in your application code.

Formatted choices override the default 'metavar' which is normally
derived from 'dest'.  This is usually what you want because the user
never sees the 'dest' parameter.  If this display isn’t desirable
(perhaps because there are many choices), just specify an explicit *note
metavar: 3372.


File: python.info,  Node: required,  Next: help,  Prev: choices,  Up: The add_argument method

5.17.1.25 required
..................

In general, the ‘argparse’ module assumes that flags like ‘-f’ and
‘--bar’ indicate 'optional' arguments, which can always be omitted at
the command line.  To make an option 'required', ‘True’ can be specified
for the ‘required=’ keyword argument to *note add_argument(): 4bd.:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('--foo', required=True)
     >>> parser.parse_args(['--foo', 'BAR'])
     Namespace(foo='BAR')
     >>> parser.parse_args([])
     usage: [-h] --foo FOO
     : error: the following arguments are required: --foo

As the example shows, if an option is marked as ‘required’, *note
parse_args(): 3353. will report an error if that option is not present
at the command line.

     Nota: Required options are generally considered bad form because
     users expect 'options' to be 'optional', and thus they should be
     avoided when possible.


File: python.info,  Node: help,  Next: metavar,  Prev: required,  Up: The add_argument method

5.17.1.26 help
..............

The ‘help’ value is a string containing a brief description of the
argument.  When a user requests help (usually by using ‘-h’ or ‘--help’
at the command line), these ‘help’ descriptions will be displayed with
each argument.

The ‘help’ strings can include various format specifiers to avoid
repetition of things like the program name or the argument *note
default: 191a.  The available specifiers include the program name,
‘%(prog)s’ and most keyword arguments to *note add_argument(): 4bd, e.g.
‘%(default)s’, ‘%(type)s’, etc.:

     >>> parser = argparse.ArgumentParser(prog='frobble')
     >>> parser.add_argument('bar', nargs='?', type=int, default=42,
     ...                     help='the bar to %(prog)s (default: %(default)s)')
     >>> parser.print_help()
     usage: frobble [-h] [bar]

     positional arguments:
      bar     the bar to frobble (default: 42)

     options:
      -h, --help  show this help message and exit

As the help string supports %-formatting, if you want a literal ‘%’ to
appear in the help string, you must escape it as ‘%%’.

‘argparse’ supports silencing the help entry for certain options, by
setting the ‘help’ value to ‘argparse.SUPPRESS’:

     >>> parser = argparse.ArgumentParser(prog='frobble')
     >>> parser.add_argument('--foo', help=argparse.SUPPRESS)
     >>> parser.print_help()
     usage: frobble [-h]

     options:
       -h, --help  show this help message and exit


File: python.info,  Node: metavar,  Next: dest,  Prev: help,  Up: The add_argument method

5.17.1.27 metavar
.................

When *note ArgumentParser: 1bd. generates help messages, it needs some
way to refer to each expected argument.  By default, ‘ArgumentParser’
objects use the *note dest: 336a. value as the «name» of each object.
By default, for positional argument actions, the *note dest: 336a. value
is used directly, and for optional argument actions, the *note dest:
336a. value is uppercased.  So, a single positional argument with
‘dest='bar'’ will be referred to as ‘bar’.  A single optional argument
‘--foo’ that should be followed by a single command-line argument will
be referred to as ‘FOO’.  An example:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('--foo')
     >>> parser.add_argument('bar')
     >>> parser.parse_args('X --foo Y'.split())
     Namespace(bar='X', foo='Y')
     >>> parser.print_help()
     usage:  [-h] [--foo FOO] bar

     positional arguments:
      bar

     options:
      -h, --help  show this help message and exit
      --foo FOO

An alternative name can be specified with ‘metavar’:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('--foo', metavar='YYY')
     >>> parser.add_argument('bar', metavar='XXX')
     >>> parser.parse_args('X --foo Y'.split())
     Namespace(bar='X', foo='Y')
     >>> parser.print_help()
     usage:  [-h] [--foo YYY] XXX

     positional arguments:
      XXX

     options:
      -h, --help  show this help message and exit
      --foo YYY

Note that ‘metavar’ only changes the 'displayed' name - the name of the
attribute on the *note parse_args(): 3353. object is still determined by
the *note dest: 336a. value.

Different values of ‘nargs’ may cause the metavar to be used multiple
times.  Providing a tuple to ‘metavar’ specifies a different display for
each of the arguments:

     >>> parser = argparse.ArgumentParser(prog='PROG')
     >>> parser.add_argument('-x', nargs=2)
     >>> parser.add_argument('--foo', nargs=2, metavar=('bar', 'baz'))
     >>> parser.print_help()
     usage: PROG [-h] [-x X X] [--foo bar baz]

     options:
      -h, --help     show this help message and exit
      -x X X
      --foo bar baz


File: python.info,  Node: dest,  Next: deprecated,  Prev: metavar,  Up: The add_argument method

5.17.1.28 dest
..............

Most *note ArgumentParser: 1bd. actions add some value as an attribute
of the object returned by *note parse_args(): 3353.  The name of this
attribute is determined by the ‘dest’ keyword argument of *note
add_argument(): 4bd.  For positional argument actions, ‘dest’ is
normally supplied as the first argument to *note add_argument(): 4bd.:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('bar')
     >>> parser.parse_args(['XXX'])
     Namespace(bar='XXX')

For optional argument actions, the value of ‘dest’ is normally inferred
from the option strings.  *note ArgumentParser: 1bd. generates the value
of ‘dest’ by taking the first long option string and stripping away the
initial ‘--’ string.  If no long option strings were supplied, ‘dest’
will be derived from the first short option string by stripping the
initial ‘-’ character.  Any internal ‘-’ characters will be converted to
‘_’ characters to make sure the string is a valid attribute name.  The
examples below illustrate this behavior:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('-f', '--foo-bar', '--foo')
     >>> parser.add_argument('-x', '-y')
     >>> parser.parse_args('-f 1 -x 2'.split())
     Namespace(foo_bar='1', x='2')
     >>> parser.parse_args('--foo 1 -y 2'.split())
     Namespace(foo_bar='1', x='2')

‘dest’ allows a custom attribute name to be provided:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument('--foo', dest='bar')
     >>> parser.parse_args('--foo XXX'.split())
     Namespace(bar='XXX')


File: python.info,  Node: deprecated,  Next: Action classes,  Prev: dest,  Up: The add_argument method

5.17.1.29 deprecated
....................

During a project’s lifetime, some arguments may need to be removed from
the command line.  Before removing them, you should inform your users
that the arguments are deprecated and will be removed.  The ‘deprecated’
keyword argument of *note add_argument(): 4bd, which defaults to
‘False’, specifies if the argument is deprecated and will be removed in
the future.  For arguments, if ‘deprecated’ is ‘True’, then a warning
will be printed to *note sys.stderr: b35. when the argument is used:

     >>> import argparse
     >>> parser = argparse.ArgumentParser(prog='snake.py')
     >>> parser.add_argument('--legs', default=0, type=int, deprecated=True)
     >>> parser.parse_args([])
     Namespace(legs=0)
     >>> parser.parse_args(['--legs', '4'])
     snake.py: warning: option '--legs' is deprecated
     Namespace(legs=4)

Added in version 3.13.


File: python.info,  Node: Action classes,  Prev: deprecated,  Up: The add_argument method

5.17.1.30 Action classes
........................

‘Action’ classes implement the Action API, a callable which returns a
callable which processes arguments from the command-line.  Any object
which follows this API may be passed as the ‘action’ parameter to *note
add_argument(): 4bd.

 -- Classe: argparse.Action (option_strings, dest, nargs=None,
          const=None, default=None, type=None, choices=None,
          required=False, help=None, metavar=None)

     ‘Action’ objects are used by an *note ArgumentParser: 1bd. to
     represent the information needed to parse a single argument from
     one or more strings from the command line.  The ‘Action’ class must
     accept the two positional arguments plus any keyword arguments
     passed to *note ArgumentParser.add_argument(): 4bd. except for the
     ‘action’ itself.

     Instances of ‘Action’ (or return value of any callable to the
     ‘action’ parameter) should have attributes ‘dest’,
     ‘option_strings’, ‘default’, ‘type’, ‘required’, ‘help’, etc.
     defined.  The easiest way to ensure these attributes are defined is
     to call ‘Action.__init__()’.

      -- Metodo: __call__ (parser, namespace, values,
               option_string=None)

          ‘Action’ instances should be callable, so subclasses must
          override the ‘__call__()’ method, which should accept four
          parameters:

             * 'parser' - The *note ArgumentParser: 1bd. object which
               contains this action.

             * 'namespace' - The *note Namespace: 3354. object that will
               be returned by *note parse_args(): 3353.  Most actions
               add an attribute to this object using *note setattr():
               259a.

             * 'values' - The associated command-line arguments, with
               any type conversions applied.  Type conversions are
               specified with the *note type: 3369. keyword argument to
               *note add_argument(): 4bd.

             * 'option_string' - The option string that was used to
               invoke this action.  The ‘option_string’ argument is
               optional, and will be absent if the action is associated
               with a positional argument.

          The ‘__call__()’ method may perform arbitrary actions, but
          will typically set attributes on the ‘namespace’ based on
          ‘dest’ and ‘values’.

      -- Metodo: format_usage ()

          ‘Action’ subclasses can define a ‘format_usage()’ method that
          takes no argument and return a string which will be used when
          printing the usage of the program.  If such method is not
          provided, a sensible default will be used.

 -- Classe: argparse.BooleanOptionalAction

     A subclass of *note Action: 1b74. for handling boolean flags with
     positive and negative options.  Adding a single argument such as
     ‘--foo’ automatically creates both ‘--foo’ and ‘--no-foo’ options,
     storing ‘True’ and ‘False’ respectively:

          >>> import argparse
          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo', action=argparse.BooleanOptionalAction)
          >>> parser.parse_args(['--no-foo'])
          Namespace(foo=False)

     Added in version 3.9.


File: python.info,  Node: The parse_args method,  Next: Other utilities,  Prev: The add_argument method,  Up: argparse — Parser for command-line options arguments and subcommands

5.17.1.31 The parse_args() method
.................................

 -- Metodo: ArgumentParser.parse_args (args=None, namespace=None)

     Convert argument strings to objects and assign them as attributes
     of the namespace.  Return the populated namespace.

     Previous calls to *note add_argument(): 4bd. determine exactly what
     objects are created and how they are assigned.  See the
     documentation for ‘add_argument()’ for details.

        * *note args: 3387. - List of strings to parse.  The default is
          taken from *note sys.argv: 146c.

        * *note namespace: 3388. - An object to take the attributes.
          The default is a new empty *note Namespace: 3354. object.

* Menu:

* Option value syntax::
* Invalid arguments::
* Arguments containing -::
* Argument abbreviations (prefix matching): Argument abbreviations prefix matching.
* Beyond sys.argv: Beyond sys argv.
* The Namespace object::


File: python.info,  Node: Option value syntax,  Next: Invalid arguments,  Up: The parse_args method

5.17.1.32 Option value syntax
.............................

The *note parse_args(): 3353. method supports several ways of specifying
the value of an option (if it takes one).  In the simplest case, the
option and its value are passed as two separate arguments:

     >>> parser = argparse.ArgumentParser(prog='PROG')
     >>> parser.add_argument('-x')
     >>> parser.add_argument('--foo')
     >>> parser.parse_args(['-x', 'X'])
     Namespace(foo=None, x='X')
     >>> parser.parse_args(['--foo', 'FOO'])
     Namespace(foo='FOO', x=None)

For long options (options with names longer than a single character),
the option and value can also be passed as a single command-line
argument, using ‘=’ to separate them:

     >>> parser.parse_args(['--foo=FOO'])
     Namespace(foo='FOO', x=None)

For short options (options only one character long), the option and its
value can be concatenated:

     >>> parser.parse_args(['-xX'])
     Namespace(foo=None, x='X')

Several short options can be joined together, using only a single ‘-’
prefix, as long as only the last option (or none of them) requires a
value:

     >>> parser = argparse.ArgumentParser(prog='PROG')
     >>> parser.add_argument('-x', action='store_true')
     >>> parser.add_argument('-y', action='store_true')
     >>> parser.add_argument('-z')
     >>> parser.parse_args(['-xyzZ'])
     Namespace(x=True, y=True, z='Z')


File: python.info,  Node: Invalid arguments,  Next: Arguments containing -,  Prev: Option value syntax,  Up: The parse_args method

5.17.1.33 Invalid arguments
...........................

While parsing the command line, *note parse_args(): 3353. checks for a
variety of errors, including ambiguous options, invalid types, invalid
options, wrong number of positional arguments, etc.  When it encounters
such an error, it exits and prints the error along with a usage message:

     >>> parser = argparse.ArgumentParser(prog='PROG')
     >>> parser.add_argument('--foo', type=int)
     >>> parser.add_argument('bar', nargs='?')

     >>> # invalid type
     >>> parser.parse_args(['--foo', 'spam'])
     usage: PROG [-h] [--foo FOO] [bar]
     PROG: error: argument --foo: invalid int value: 'spam'

     >>> # invalid option
     >>> parser.parse_args(['--bar'])
     usage: PROG [-h] [--foo FOO] [bar]
     PROG: error: no such option: --bar

     >>> # wrong number of arguments
     >>> parser.parse_args(['spam', 'badger'])
     usage: PROG [-h] [--foo FOO] [bar]
     PROG: error: extra arguments found: badger


File: python.info,  Node: Arguments containing -,  Next: Argument abbreviations prefix matching,  Prev: Invalid arguments,  Up: The parse_args method

5.17.1.34 Arguments containing ‘-’
..................................

The *note parse_args(): 3353. method attempts to give errors whenever
the user has clearly made a mistake, but some situations are inherently
ambiguous.  For example, the command-line argument ‘-1’ could either be
an attempt to specify an option or an attempt to provide a positional
argument.  The *note parse_args(): 3353. method is cautious here:
positional arguments may only begin with ‘-’ if they look like negative
numbers and there are no options in the parser that look like negative
numbers:

     >>> parser = argparse.ArgumentParser(prog='PROG')
     >>> parser.add_argument('-x')
     >>> parser.add_argument('foo', nargs='?')

     >>> # no negative number options, so -1 is a positional argument
     >>> parser.parse_args(['-x', '-1'])
     Namespace(foo=None, x='-1')

     >>> # no negative number options, so -1 and -5 are positional arguments
     >>> parser.parse_args(['-x', '-1', '-5'])
     Namespace(foo='-5', x='-1')

     >>> parser = argparse.ArgumentParser(prog='PROG')
     >>> parser.add_argument('-1', dest='one')
     >>> parser.add_argument('foo', nargs='?')

     >>> # negative number options present, so -1 is an option
     >>> parser.parse_args(['-1', 'X'])
     Namespace(foo=None, one='X')

     >>> # negative number options present, so -2 is an option
     >>> parser.parse_args(['-2'])
     usage: PROG [-h] [-1 ONE] [foo]
     PROG: error: no such option: -2

     >>> # negative number options present, so both -1s are options
     >>> parser.parse_args(['-1', '-1'])
     usage: PROG [-h] [-1 ONE] [foo]
     PROG: error: argument -1: expected one argument

If you have positional arguments that must begin with ‘-’ and don’t look
like negative numbers, you can insert the pseudo-argument ‘'--'’ which
tells *note parse_args(): 3353. that everything after that is a
positional argument:

     >>> parser.parse_args(['--', '-f'])
     Namespace(foo='-f', one=None)

See also *note the argparse howto on ambiguous arguments: 3378. for more
details.


File: python.info,  Node: Argument abbreviations prefix matching,  Next: Beyond sys argv,  Prev: Arguments containing -,  Up: The parse_args method

5.17.1.35 Argument abbreviations (prefix matching)
..................................................

The *note parse_args(): 3353. method *note by default: fc1. allows long
options to be abbreviated to a prefix, if the abbreviation is
unambiguous (the prefix matches a unique option):

     >>> parser = argparse.ArgumentParser(prog='PROG')
     >>> parser.add_argument('-bacon')
     >>> parser.add_argument('-badger')
     >>> parser.parse_args('-bac MMM'.split())
     Namespace(bacon='MMM', badger=None)
     >>> parser.parse_args('-bad WOOD'.split())
     Namespace(bacon=None, badger='WOOD')
     >>> parser.parse_args('-ba BA'.split())
     usage: PROG [-h] [-bacon BACON] [-badger BADGER]
     PROG: error: ambiguous option: -ba could match -badger, -bacon

An error is produced for arguments that could produce more than one
options.  This feature can be disabled by setting *note allow_abbrev:
fc1. to ‘False’.


File: python.info,  Node: Beyond sys argv,  Next: The Namespace object,  Prev: Argument abbreviations prefix matching,  Up: The parse_args method

5.17.1.36 Beyond ‘sys.argv’
...........................

Sometimes it may be useful to have an *note ArgumentParser: 1bd. parse
arguments other than those of *note sys.argv: 146c.  This can be
accomplished by passing a list of strings to *note parse_args(): 3353.
This is useful for testing at the interactive prompt:

     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument(
     ...     'integers', metavar='int', type=int, choices=range(10),
     ...     nargs='+', help='an integer in the range 0..9')
     >>> parser.add_argument(
     ...     '--sum', dest='accumulate', action='store_const', const=sum,
     ...     default=max, help='sum the integers (default: find the max)')
     >>> parser.parse_args(['1', '2', '3', '4'])
     Namespace(accumulate=<built-in function max>, integers=[1, 2, 3, 4])
     >>> parser.parse_args(['1', '2', '3', '4', '--sum'])
     Namespace(accumulate=<built-in function sum>, integers=[1, 2, 3, 4])


File: python.info,  Node: The Namespace object,  Prev: Beyond sys argv,  Up: The parse_args method

5.17.1.37 The Namespace object
..............................

 -- Classe: argparse.Namespace

     Simple class used by default by *note parse_args(): 3353. to create
     an object holding attributes and return it.

     This class is deliberately simple, just an *note object: c80.
     subclass with a readable string representation.  If you prefer to
     have dict-like view of the attributes, you can use the standard
     Python idiom, *note vars(): 1e0b.:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo')
          >>> args = parser.parse_args(['--foo', 'BAR'])
          >>> vars(args)
          {'foo': 'BAR'}

     It may also be useful to have an *note ArgumentParser: 1bd. assign
     attributes to an already existing object, rather than a new *note
     Namespace: 3354. object.  This can be achieved by specifying the
     ‘namespace=’ keyword argument:

          >>> class C:
          ...     pass
          ...
          >>> c = C()
          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo')
          >>> parser.parse_args(args=['--foo', 'BAR'], namespace=c)
          >>> c.foo
          'BAR'


File: python.info,  Node: Other utilities,  Next: Exceptions<10>,  Prev: The parse_args method,  Up: argparse — Parser for command-line options arguments and subcommands

5.17.1.38 Other utilities
.........................

* Menu:

* Subcommands::
* FileType objects::
* Argument groups::
* Mutual exclusion::
* Parser defaults::
* Printing help::
* Partial parsing::
* Customizing file parsing::
* Exiting methods::
* Intermixed parsing::
* Registering custom types or actions::


File: python.info,  Node: Subcommands,  Next: FileType objects,  Up: Other utilities

5.17.1.39 Subcommands
.....................

 -- Metodo: ArgumentParser.add_subparsers (*[, title][, description][,
          prog][, parser_class][, action][, dest][, required][, help][,
          metavar])

     Many programs split up their functionality into a number of
     subcommands, for example, the ‘svn’ program can invoke subcommands
     like ‘svn checkout’, ‘svn update’, and ‘svn commit’.  Splitting up
     functionality this way can be a particularly good idea when a
     program performs several different functions which require
     different kinds of command-line arguments.  *note ArgumentParser:
     1bd. supports the creation of such subcommands with the
     ‘add_subparsers()’ method.  The ‘add_subparsers()’ method is
     normally called with no arguments and returns a special action
     object.  This object has a single method, ‘add_parser()’, which
     takes a command name and any ‘ArgumentParser’ constructor
     arguments, and returns an ‘ArgumentParser’ object that can be
     modified as usual.

     Description of parameters:

        * 'title' - title for the sub-parser group in help output; by
          default «subcommands» if description is provided, otherwise
          uses title for positional arguments

        * 'description' - description for the sub-parser group in help
          output, by default ‘None’

        * 'prog' - usage information that will be displayed with
          subcommand help, by default the name of the program and any
          positional arguments before the subparser argument

        * 'parser_class' - class which will be used to create sub-parser
          instances, by default the class of the current parser (e.g.
          *note ArgumentParser: 1bd.)

        * *note action: 1913. - the basic type of action to be taken
          when this argument is encountered at the command line

        * *note dest: 336a. - name of the attribute under which
          subcommand name will be stored; by default ‘None’ and no value
          is stored

        * *note required: 3370. - Whether or not a subcommand must be
          provided, by default ‘False’ (added in 3.7)

        * *note help: 3371. - help for sub-parser group in help output,
          by default ‘None’

        * *note metavar: 3372. - string presenting available subcommands
          in help; by default it is ‘None’ and presents subcommands in
          form {cmd1, cmd2, ..}

     Some example usage:

          >>> # create the top-level parser
          >>> parser = argparse.ArgumentParser(prog='PROG')
          >>> parser.add_argument('--foo', action='store_true', help='foo help')
          >>> subparsers = parser.add_subparsers(help='subcommand help')
          >>>
          >>> # create the parser for the "a" command
          >>> parser_a = subparsers.add_parser('a', help='a help')
          >>> parser_a.add_argument('bar', type=int, help='bar help')
          >>>
          >>> # create the parser for the "b" command
          >>> parser_b = subparsers.add_parser('b', help='b help')
          >>> parser_b.add_argument('--baz', choices=('X', 'Y', 'Z'), help='baz help')
          >>>
          >>> # parse some argument lists
          >>> parser.parse_args(['a', '12'])
          Namespace(bar=12, foo=False)
          >>> parser.parse_args(['--foo', 'b', '--baz', 'Z'])
          Namespace(baz='Z', foo=True)

     Note that the object returned by *note parse_args(): 3353. will
     only contain attributes for the main parser and the subparser that
     was selected by the command line (and not any other subparsers).
     So in the example above, when the ‘a’ command is specified, only
     the ‘foo’ and ‘bar’ attributes are present, and when the ‘b’
     command is specified, only the ‘foo’ and ‘baz’ attributes are
     present.

     Similarly, when a help message is requested from a subparser, only
     the help for that particular parser will be printed.  The help
     message will not include parent parser or sibling parser messages.
     (A help message for each subparser command, however, can be given
     by supplying the ‘help=’ argument to ‘add_parser()’ as above.)

          >>> parser.parse_args(['--help'])
          usage: PROG [-h] [--foo] {a,b} ...

          positional arguments:
            {a,b}   subcommand help
              a     a help
              b     b help

          options:
            -h, --help  show this help message and exit
            --foo   foo help

          >>> parser.parse_args(['a', '--help'])
          usage: PROG a [-h] bar

          positional arguments:
            bar     bar help

          options:
            -h, --help  show this help message and exit

          >>> parser.parse_args(['b', '--help'])
          usage: PROG b [-h] [--baz {X,Y,Z}]

          options:
            -h, --help     show this help message and exit
            --baz {X,Y,Z}  baz help

     The *note add_subparsers(): e13. method also supports ‘title’ and
     ‘description’ keyword arguments.  When either is present, the
     subparser’s commands will appear in their own group in the help
     output.  For example:

          >>> parser = argparse.ArgumentParser()
          >>> subparsers = parser.add_subparsers(title='subcommands',
          ...                                    description='valid subcommands',
          ...                                    help='additional help')
          >>> subparsers.add_parser('foo')
          >>> subparsers.add_parser('bar')
          >>> parser.parse_args(['-h'])
          usage:  [-h] {foo,bar} ...

          options:
            -h, --help  show this help message and exit

          subcommands:
            valid subcommands

            {foo,bar}   additional help

     Furthermore, ‘add_parser()’ supports an additional 'aliases'
     argument, which allows multiple strings to refer to the same
     subparser.  This example, like ‘svn’, aliases ‘co’ as a shorthand
     for ‘checkout’:

          >>> parser = argparse.ArgumentParser()
          >>> subparsers = parser.add_subparsers()
          >>> checkout = subparsers.add_parser('checkout', aliases=['co'])
          >>> checkout.add_argument('foo')
          >>> parser.parse_args(['co', 'bar'])
          Namespace(foo='bar')

     ‘add_parser()’ supports also an additional 'deprecated' argument,
     which allows to deprecate the subparser.

          >>> import argparse
          >>> parser = argparse.ArgumentParser(prog='chicken.py')
          >>> subparsers = parser.add_subparsers()
          >>> run = subparsers.add_parser('run')
          >>> fly = subparsers.add_parser('fly', deprecated=True)
          >>> parser.parse_args(['fly'])
          chicken.py: warning: command 'fly' is deprecated
          Namespace()

     Added in version 3.13.

     One particularly effective way of handling subcommands is to
     combine the use of the *note add_subparsers(): e13. method with
     calls to *note set_defaults(): 336c. so that each subparser knows
     which Python function it should execute.  For example:

          >>> # subcommand functions
          >>> def foo(args):
          ...     print(args.x * args.y)
          ...
          >>> def bar(args):
          ...     print('((%s))' % args.z)
          ...
          >>> # create the top-level parser
          >>> parser = argparse.ArgumentParser()
          >>> subparsers = parser.add_subparsers(required=True)
          >>>
          >>> # create the parser for the "foo" command
          >>> parser_foo = subparsers.add_parser('foo')
          >>> parser_foo.add_argument('-x', type=int, default=1)
          >>> parser_foo.add_argument('y', type=float)
          >>> parser_foo.set_defaults(func=foo)
          >>>
          >>> # create the parser for the "bar" command
          >>> parser_bar = subparsers.add_parser('bar')
          >>> parser_bar.add_argument('z')
          >>> parser_bar.set_defaults(func=bar)
          >>>
          >>> # parse the args and call whatever function was selected
          >>> args = parser.parse_args('foo 1 -x 2'.split())
          >>> args.func(args)
          2.0
          >>>
          >>> # parse the args and call whatever function was selected
          >>> args = parser.parse_args('bar XYZYX'.split())
          >>> args.func(args)
          ((XYZYX))

     This way, you can let *note parse_args(): 3353. do the job of
     calling the appropriate function after argument parsing is
     complete.  Associating functions with actions like this is
     typically the easiest way to handle the different actions for each
     of your subparsers.  However, if it is necessary to check the name
     of the subparser that was invoked, the ‘dest’ keyword argument to
     the *note add_subparsers(): e13. call will work:

          >>> parser = argparse.ArgumentParser()
          >>> subparsers = parser.add_subparsers(dest='subparser_name')
          >>> subparser1 = subparsers.add_parser('1')
          >>> subparser1.add_argument('-x')
          >>> subparser2 = subparsers.add_parser('2')
          >>> subparser2.add_argument('y')
          >>> parser.parse_args(['2', 'frobble'])
          Namespace(subparser_name='2', y='frobble')

     Cambiato nella versione 3.7: New 'required' keyword-only parameter.

     Cambiato nella versione 3.14: Subparser’s 'prog' is no longer
     affected by a custom usage message in the main parser.


File: python.info,  Node: FileType objects,  Next: Argument groups,  Prev: Subcommands,  Up: Other utilities

5.17.1.40 FileType objects
..........................

 -- Classe: argparse.FileType (mode='r', bufsize=-1, encoding=None,
          errors=None)

     The *note FileType: 30c. factory creates objects that can be passed
     to the type argument of *note ArgumentParser.add_argument(): 4bd.
     Arguments that have *note FileType: 30c. objects as their type will
     open command-line arguments as files with the requested modes,
     buffer sizes, encodings and error handling (see the *note open():
     316. function for more details):

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--raw', type=argparse.FileType('wb', 0))
          >>> parser.add_argument('out', type=argparse.FileType('w', encoding='UTF-8'))
          >>> parser.parse_args(['--raw', 'raw.dat', 'file.txt'])
          Namespace(out=<_io.TextIOWrapper name='file.txt' mode='w' encoding='UTF-8'>, raw=<_io.FileIO name='raw.dat' mode='wb'>)

     FileType objects understand the pseudo-argument ‘'-'’ and
     automatically convert this into *note sys.stdin: 760. for readable
     *note FileType: 30c. objects and *note sys.stdout: ccf. for
     writable *note FileType: 30c. objects:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('infile', type=argparse.FileType('r'))
          >>> parser.parse_args(['-'])
          Namespace(infile=<_io.TextIOWrapper name='<stdin>' encoding='UTF-8'>)

          Nota: If one argument uses 'FileType' and then a subsequent
          argument fails, an error is reported but the file is not
          automatically closed.  This can also clobber the output files.
          In this case, it would be better to wait until after the
          parser has run and then use the *note with: 186.-statement to
          manage the files.

     Cambiato nella versione 3.4: Added the 'encodings' and 'errors'
     parameters.

     Deprecato dalla versione 3.14.


File: python.info,  Node: Argument groups,  Next: Mutual exclusion,  Prev: FileType objects,  Up: Other utilities

5.17.1.41 Argument groups
.........................

 -- Metodo: ArgumentParser.add_argument_group (title=None,
          description=None, *[, argument_default][, conflict_handler])

     By default, *note ArgumentParser: 1bd. groups command-line
     arguments into «positional arguments» and «options» when displaying
     help messages.  When there is a better conceptual grouping of
     arguments than this default one, appropriate groups can be created
     using the ‘add_argument_group()’ method:

          >>> parser = argparse.ArgumentParser(prog='PROG', add_help=False)
          >>> group = parser.add_argument_group('group')
          >>> group.add_argument('--foo', help='foo help')
          >>> group.add_argument('bar', help='bar help')
          >>> parser.print_help()
          usage: PROG [--foo FOO] bar

          group:
            bar    bar help
            --foo FOO  foo help

     The *note add_argument_group(): 2eb. method returns an argument
     group object which has an *note add_argument(): 4bd. method just
     like a regular *note ArgumentParser: 1bd.  When an argument is
     added to the group, the parser treats it just like a normal
     argument, but displays the argument in a separate group for help
     messages.  The ‘add_argument_group()’ method accepts 'title' and
     'description' arguments which can be used to customize this
     display:

          >>> parser = argparse.ArgumentParser(prog='PROG', add_help=False)
          >>> group1 = parser.add_argument_group('group1', 'group1 description')
          >>> group1.add_argument('foo', help='foo help')
          >>> group2 = parser.add_argument_group('group2', 'group2 description')
          >>> group2.add_argument('--bar', help='bar help')
          >>> parser.print_help()
          usage: PROG [--bar BAR] foo

          group1:
            group1 description

            foo    foo help

          group2:
            group2 description

            --bar BAR  bar help

     The optional, keyword-only parameters *note argument_default: 335d.
     and *note conflict_handler: 335e. allow for finer-grained control
     of the behavior of the argument group.  These parameters have the
     same meaning as in the *note ArgumentParser: 1bd. constructor, but
     apply specifically to the argument group rather than the entire
     parser.

     Note that any arguments not in your user-defined groups will end up
     back in the usual «positional arguments» and «optional arguments»
     sections.

     Deprecated since version 3.11, removed in version 3.14: Calling
     *note add_argument_group(): 2eb. on an argument group now raises an
     exception.  This nesting was never supported, often failed to work
     correctly, and was unintentionally exposed through inheritance.

     Deprecato dalla versione 3.14: Passing *note prefix_chars: 335b. to
     *note add_argument_group(): 2eb. is now deprecated.


File: python.info,  Node: Mutual exclusion,  Next: Parser defaults,  Prev: Argument groups,  Up: Other utilities

5.17.1.42 Mutual exclusion
..........................

 -- Metodo: ArgumentParser.add_mutually_exclusive_group (required=False)

     Create a mutually exclusive group.  ‘argparse’ will make sure that
     only one of the arguments in the mutually exclusive group was
     present on the command line:

          >>> parser = argparse.ArgumentParser(prog='PROG')
          >>> group = parser.add_mutually_exclusive_group()
          >>> group.add_argument('--foo', action='store_true')
          >>> group.add_argument('--bar', action='store_false')
          >>> parser.parse_args(['--foo'])
          Namespace(bar=True, foo=True)
          >>> parser.parse_args(['--bar'])
          Namespace(bar=False, foo=False)
          >>> parser.parse_args(['--foo', '--bar'])
          usage: PROG [-h] [--foo | --bar]
          PROG: error: argument --bar: not allowed with argument --foo

     The *note add_mutually_exclusive_group(): 2ed. method also accepts
     a 'required' argument, to indicate that at least one of the
     mutually exclusive arguments is required:

          >>> parser = argparse.ArgumentParser(prog='PROG')
          >>> group = parser.add_mutually_exclusive_group(required=True)
          >>> group.add_argument('--foo', action='store_true')
          >>> group.add_argument('--bar', action='store_false')
          >>> parser.parse_args([])
          usage: PROG [-h] (--foo | --bar)
          PROG: error: one of the arguments --foo --bar is required

     Note that currently mutually exclusive argument groups do not
     support the 'title' and 'description' arguments of *note
     add_argument_group(): 2eb.  However, a mutually exclusive group can
     be added to an argument group that has a title and description.
     For example:

          >>> parser = argparse.ArgumentParser(prog='PROG')
          >>> group = parser.add_argument_group('Group title', 'Group description')
          >>> exclusive_group = group.add_mutually_exclusive_group(required=True)
          >>> exclusive_group.add_argument('--foo', help='foo help')
          >>> exclusive_group.add_argument('--bar', help='bar help')
          >>> parser.print_help()
          usage: PROG [-h] (--foo FOO | --bar BAR)

          options:
            -h, --help  show this help message and exit

          Group title:
            Group description

            --foo FOO   foo help
            --bar BAR   bar help

     Deprecated since version 3.11, removed in version 3.14: Calling
     *note add_argument_group(): 2eb. or *note
     add_mutually_exclusive_group(): 2ed. on a mutually exclusive group
     now raises an exception.  This nesting was never supported, often
     failed to work correctly, and was unintentionally exposed through
     inheritance.


File: python.info,  Node: Parser defaults,  Next: Printing help,  Prev: Mutual exclusion,  Up: Other utilities

5.17.1.43 Parser defaults
.........................

 -- Metodo: ArgumentParser.set_defaults (**kwargs)

     Most of the time, the attributes of the object returned by *note
     parse_args(): 3353. will be fully determined by inspecting the
     command-line arguments and the argument actions.  *note
     set_defaults(): 336c. allows some additional attributes that are
     determined without any inspection of the command line to be added:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('foo', type=int)
          >>> parser.set_defaults(bar=42, baz='badger')
          >>> parser.parse_args(['736'])
          Namespace(bar=42, baz='badger', foo=736)

     Note that defaults can be set at both the parser level using *note
     set_defaults(): 336c. and at the argument level using *note
     add_argument(): 4bd.  If both are called for the same argument, the
     last default set for an argument is used:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo', default='bar')
          >>> parser.set_defaults(foo='spam')
          >>> parser.parse_args([])
          Namespace(foo='spam')

     Parser-level defaults can be particularly useful when working with
     multiple parsers.  See the *note add_subparsers(): e13. method for
     an example of this type.

 -- Metodo: ArgumentParser.get_default (dest)

     Get the default value for a namespace attribute, as set by either
     *note add_argument(): 4bd. or by *note set_defaults(): 336c.:

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo', default='badger')
          >>> parser.get_default('foo')
          'badger'


File: python.info,  Node: Printing help,  Next: Partial parsing,  Prev: Parser defaults,  Up: Other utilities

5.17.1.44 Printing help
.......................

In most typical applications, *note parse_args(): 3353. will take care
of formatting and printing any usage or error messages.  However,
several formatting methods are available:

 -- Metodo: ArgumentParser.print_usage (file=None)

     Print a brief description of how the *note ArgumentParser: 1bd.
     should be invoked on the command line.  If 'file' is ‘None’, *note
     sys.stdout: ccf. is assumed.

 -- Metodo: ArgumentParser.print_help (file=None)

     Print a help message, including the program usage and information
     about the arguments registered with the *note ArgumentParser: 1bd.
     If 'file' is ‘None’, *note sys.stdout: ccf. is assumed.

There are also variants of these methods that simply return a string
instead of printing it:

 -- Metodo: ArgumentParser.format_usage ()

     Return a string containing a brief description of how the *note
     ArgumentParser: 1bd. should be invoked on the command line.

 -- Metodo: ArgumentParser.format_help ()

     Return a string containing a help message, including the program
     usage and information about the arguments registered with the *note
     ArgumentParser: 1bd.


File: python.info,  Node: Partial parsing,  Next: Customizing file parsing,  Prev: Printing help,  Up: Other utilities

5.17.1.45 Partial parsing
.........................

 -- Metodo: ArgumentParser.parse_known_args (args=None, namespace=None)

     Sometimes a script only needs to handle a specific set of
     command-line arguments, leaving any unrecognized arguments for
     another script or program.  In these cases, the *note
     parse_known_args(): 339b. method can be useful.

     This method works similarly to *note parse_args(): 3353, but it
     does not raise an error for extra, unrecognized arguments.
     Instead, it parses the known arguments and returns a two item tuple
     that contains the populated namespace and the list of any
     unrecognized arguments.

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo', action='store_true')
          >>> parser.add_argument('bar')
          >>> parser.parse_known_args(['--foo', '--badger', 'BAR', 'spam'])
          (Namespace(bar='BAR', foo=True), ['--badger', 'spam'])

     Avvertimento: *note Prefix matching: fc0. rules apply to *note
     parse_known_args(): 339b.  The parser may consume an option even if
     it’s just a prefix of one of its known options, instead of leaving
     it in the remaining arguments list.


File: python.info,  Node: Customizing file parsing,  Next: Exiting methods,  Prev: Partial parsing,  Up: Other utilities

5.17.1.46 Customizing file parsing
..................................

 -- Metodo: ArgumentParser.convert_arg_line_to_args (arg_line)

     Arguments that are read from a file (see the
     'fromfile_prefix_chars' keyword argument to the *note
     ArgumentParser: 1bd. constructor) are read one argument per line.
     *note convert_arg_line_to_args(): 336b. can be overridden for
     fancier reading.

     This method takes a single argument 'arg_line' which is a string
     read from the argument file.  It returns a list of arguments parsed
     from this string.  The method is called once per line read from the
     argument file, in order.

     A useful override of this method is one that treats each
     space-separated word as an argument.  The following example
     demonstrates how to do this:

          class MyArgumentParser(argparse.ArgumentParser):
              def convert_arg_line_to_args(self, arg_line):
                  return arg_line.split()


File: python.info,  Node: Exiting methods,  Next: Intermixed parsing,  Prev: Customizing file parsing,  Up: Other utilities

5.17.1.47 Exiting methods
.........................

 -- Metodo: ArgumentParser.exit (status=0, message=None)

     This method terminates the program, exiting with the specified
     'status' and, if given, it prints a 'message' to *note sys.stderr:
     b35. before that.  The user can override this method to handle
     these steps differently:

          class ErrorCatchingArgumentParser(argparse.ArgumentParser):
              def exit(self, status=0, message=None):
                  if status:
                      raise Exception(f'Exiting because of an error: {message}')
                  exit(status)

 -- Metodo: ArgumentParser.error (message)

     This method prints a usage message, including the 'message', to
     *note sys.stderr: b35. and terminates the program with a status
     code of 2.


File: python.info,  Node: Intermixed parsing,  Next: Registering custom types or actions,  Prev: Exiting methods,  Up: Other utilities

5.17.1.48 Intermixed parsing
............................

 -- Metodo: ArgumentParser.parse_intermixed_args (args=None,
          namespace=None)

 -- Metodo: ArgumentParser.parse_known_intermixed_args (args=None,
          namespace=None)

     A number of Unix commands allow the user to intermix optional
     arguments with positional arguments.  The *note
     parse_intermixed_args(): cf9. and *note
     parse_known_intermixed_args(): 33a1. methods support this parsing
     style.

     These parsers do not support all the ‘argparse’ features, and will
     raise exceptions if unsupported features are used.  In particular,
     subparsers, and mutually exclusive groups that include both
     optionals and positionals are not supported.

     The following example shows the difference between *note
     parse_known_args(): 339b. and *note parse_intermixed_args(): cf9.:
     the former returns ‘['2', '3']’ as unparsed arguments, while the
     latter collects all the positionals into ‘rest’.

          >>> parser = argparse.ArgumentParser()
          >>> parser.add_argument('--foo')
          >>> parser.add_argument('cmd')
          >>> parser.add_argument('rest', nargs='*', type=int)
          >>> parser.parse_known_args('doit 1 --foo bar 2 3'.split())
          (Namespace(cmd='doit', foo='bar', rest=[1]), ['2', '3'])
          >>> parser.parse_intermixed_args('doit 1 --foo bar 2 3'.split())
          Namespace(cmd='doit', foo='bar', rest=[1, 2, 3])

     *note parse_known_intermixed_args(): 33a1. returns a two item tuple
     containing the populated namespace and the list of remaining
     argument strings.  *note parse_intermixed_args(): cf9. raises an
     error if there are any remaining unparsed argument strings.

     Added in version 3.7.


File: python.info,  Node: Registering custom types or actions,  Prev: Intermixed parsing,  Up: Other utilities

5.17.1.49 Registering custom types or actions
.............................................

 -- Metodo: ArgumentParser.register (registry_name, value, object)

     Sometimes it’s desirable to use a custom string in error messages
     to provide more user-friendly output.  In these cases, ‘register()’
     can be used to register custom actions or types with a parser and
     allow you to reference the type by their registered name instead of
     their callable name.

     The ‘register()’ method accepts three arguments - a
     'registry_name', specifying the internal registry where the object
     will be stored (e.g., ‘action’, ‘type’), 'value', which is the key
     under which the object will be registered, and object, the callable
     to be registered.

     The following example shows how to register a custom type with a
     parser:

          >>> import argparse
          >>> parser = argparse.ArgumentParser()
          >>> parser.register('type', 'hexadecimal integer', lambda s: int(s, 16))
          >>> parser.add_argument('--foo', type='hexadecimal integer')
          _StoreAction(option_strings=['--foo'], dest='foo', nargs=None, const=None, default=None, type='hexadecimal integer', choices=None, required=False, help=None, metavar=None, deprecated=False)
          >>> parser.parse_args(['--foo', '0xFA'])
          Namespace(foo=250)
          >>> parser.parse_args(['--foo', '1.2'])
          usage: PROG [-h] [--foo FOO]
          PROG: error: argument --foo: invalid 'hexadecimal integer' value: '1.2'


File: python.info,  Node: Exceptions<10>,  Prev: Other utilities,  Up: argparse — Parser for command-line options arguments and subcommands

5.17.1.50 Exceptions
....................

 -- Eccezione: argparse.ArgumentError

     An error from creating or using an argument (optional or
     positional).

     The string value of this exception is the message, augmented with
     information about the argument that caused it.

 -- Eccezione: argparse.ArgumentTypeError

     Raised when something goes wrong converting a command line string
     to a type.

Guides and Tutorials
....................

* Menu:

* Argparse Tutorial::
* Migrating optparse code to argparse::


File: python.info,  Node: Argparse Tutorial,  Next: Migrating optparse code to argparse,  Up: Exceptions<10>

5.17.1.51 Argparse Tutorial
...........................


author: Tshepang Mbambo

This tutorial is intended to be a gentle introduction to *note argparse:
7, the recommended command-line parsing module in the Python standard
library.

     Nota: The standard library includes two other libraries directly
     related to command-line parameter processing: the lower level *note
     optparse: a4. module (which may require more code to configure for
     a given application, but also allows an application to request
     behaviors that ‘argparse’ doesn’t support), and the very low level
     *note getopt: 65. (which specifically serves as an equivalent to
     the ‘getopt()’ family of functions available to C programmers).
     While neither of those modules is covered directly in this guide,
     many of the core concepts in ‘argparse’ first originated in
     ‘optparse’, so some aspects of this tutorial will also be relevant
     to ‘optparse’ users.

* Menu:

* Concepts::
* The basics::
* Introducing Positional arguments::
* Introducing Optional arguments::
* Combining Positional and Optional arguments::
* Getting a little more advanced::
* How to translate the argparse output::
* Custom type converters::
* Conclusion::


File: python.info,  Node: Concepts,  Next: The basics,  Up: Argparse Tutorial

5.17.1.52 Concepts
..................

Let’s show the sort of functionality that we are going to explore in
this introductory tutorial by making use of the ‘ls’ command:

     $ ls
     cpython  devguide  prog.py  pypy  rm-unused-function.patch
     $ ls pypy
     ctypes_configure  demo  dotviewer  include  lib_pypy  lib-python ...
     $ ls -l
     total 20
     drwxr-xr-x 19 wena wena 4096 Feb 18 18:51 cpython
     drwxr-xr-x  4 wena wena 4096 Feb  8 12:04 devguide
     -rwxr-xr-x  1 wena wena  535 Feb 19 00:05 prog.py
     drwxr-xr-x 14 wena wena 4096 Feb  7 00:59 pypy
     -rw-r--r--  1 wena wena  741 Feb 18 01:01 rm-unused-function.patch
     $ ls --help
     Usage: ls [OPTION]... [FILE]...
     List information about the FILEs (the current directory by default).
     Sort entries alphabetically if none of -cftuvSUX nor --sort is specified.
     ...

A few concepts we can learn from the four commands:

   * The ‘ls’ command is useful when run without any options at all.  It
     defaults to displaying the contents of the current directory.

   * If we want beyond what it provides by default, we tell it a bit
     more.  In this case, we want it to display a different directory,
     ‘pypy’.  What we did is specify what is known as a positional
     argument.  It’s named so because the program should know what to do
     with the value, solely based on where it appears on the command
     line.  This concept is more relevant to a command like ‘cp’, whose
     most basic usage is ‘cp SRC DEST’.  The first position is 'what you
     want copied,' and the second position is 'where you want it copied
     to'.

   * Now, say we want to change behaviour of the program.  In our
     example, we display more info for each file instead of just showing
     the file names.  The ‘-l’ in that case is known as an optional
     argument.

   * That’s a snippet of the help text.  It’s very useful in that you
     can come across a program you have never used before, and can
     figure out how it works simply by reading its help text.


File: python.info,  Node: The basics,  Next: Introducing Positional arguments,  Prev: Concepts,  Up: Argparse Tutorial

5.17.1.53 The basics
....................

Let us start with a very simple example which does (almost) nothing:

     import argparse
     parser = argparse.ArgumentParser()
     parser.parse_args()

Following is a result of running the code:

     $ python prog.py
     $ python prog.py --help
     usage: prog.py [-h]

     options:
       -h, --help  show this help message and exit
     $ python prog.py --verbose
     usage: prog.py [-h]
     prog.py: error: unrecognized arguments: --verbose
     $ python prog.py foo
     usage: prog.py [-h]
     prog.py: error: unrecognized arguments: foo

Here is what is happening:

   * Running the script without any options results in nothing displayed
     to stdout.  Not so useful.

   * The second one starts to display the usefulness of the *note
     argparse: 7. module.  We have done almost nothing, but already we
     get a nice help message.

   * The ‘--help’ option, which can also be shortened to ‘-h’, is the
     only option we get for free (i.e.  no need to specify it).
     Specifying anything else results in an error.  But even then, we do
     get a useful usage message, also for free.


File: python.info,  Node: Introducing Positional arguments,  Next: Introducing Optional arguments,  Prev: The basics,  Up: Argparse Tutorial

5.17.1.54 Introducing Positional arguments
..........................................

An example:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("echo")
     args = parser.parse_args()
     print(args.echo)

And running the code:

     $ python prog.py
     usage: prog.py [-h] echo
     prog.py: error: the following arguments are required: echo
     $ python prog.py --help
     usage: prog.py [-h] echo

     positional arguments:
       echo

     options:
       -h, --help  show this help message and exit
     $ python prog.py foo
     foo

Here is what’s happening:

   * We’ve added the *note add_argument(): 4bd. method, which is what we
     use to specify which command-line options the program is willing to
     accept.  In this case, I’ve named it ‘echo’ so that it’s in line
     with its function.

   * Calling our program now requires us to specify an option.

   * The *note parse_args(): 3353. method actually returns some data
     from the options specified, in this case, ‘echo’.

   * The variable is some form of “magic” that *note argparse: 7.
     performs for free (i.e.  no need to specify which variable that
     value is stored in).  You will also notice that its name matches
     the string argument given to the method, ‘echo’.

Note however that, although the help display looks nice and all, it
currently is not as helpful as it can be.  For example we see that we
got ‘echo’ as a positional argument, but we don’t know what it does,
other than by guessing or by reading the source code.  So, let’s make it
a bit more useful:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("echo", help="echo the string you use here")
     args = parser.parse_args()
     print(args.echo)

And we get:

     $ python prog.py -h
     usage: prog.py [-h] echo

     positional arguments:
       echo        echo the string you use here

     options:
       -h, --help  show this help message and exit

Now, how about doing something even more useful:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("square", help="display a square of a given number")
     args = parser.parse_args()
     print(args.square**2)

Following is a result of running the code:

     $ python prog.py 4
     Traceback (most recent call last):
       File "prog.py", line 5, in <module>
         print(args.square**2)
     TypeError: unsupported operand type(s) for ** or pow(): 'str' and 'int'

That didn’t go so well.  That’s because *note argparse: 7. treats the
options we give it as strings, unless we tell it otherwise.  So, let’s
tell *note argparse: 7. to treat that input as an integer:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("square", help="display a square of a given number",
                         type=int)
     args = parser.parse_args()
     print(args.square**2)

Following is a result of running the code:

     $ python prog.py 4
     16
     $ python prog.py four
     usage: prog.py [-h] square
     prog.py: error: argument square: invalid int value: 'four'

That went well.  The program now even helpfully quits on bad illegal
input before proceeding.


File: python.info,  Node: Introducing Optional arguments,  Next: Combining Positional and Optional arguments,  Prev: Introducing Positional arguments,  Up: Argparse Tutorial

5.17.1.55 Introducing Optional arguments
........................................

So far we have been playing with positional arguments.  Let us have a
look on how to add optional ones:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("--verbosity", help="increase output verbosity")
     args = parser.parse_args()
     if args.verbosity:
         print("verbosity turned on")

And the output:

     $ python prog.py --verbosity 1
     verbosity turned on
     $ python prog.py
     $ python prog.py --help
     usage: prog.py [-h] [--verbosity VERBOSITY]

     options:
       -h, --help            show this help message and exit
       --verbosity VERBOSITY
                             increase output verbosity
     $ python prog.py --verbosity
     usage: prog.py [-h] [--verbosity VERBOSITY]
     prog.py: error: argument --verbosity: expected one argument

Here is what is happening:

   * The program is written so as to display something when
     ‘--verbosity’ is specified and display nothing when not.

   * To show that the option is actually optional, there is no error
     when running the program without it.  Note that by default, if an
     optional argument isn’t used, the relevant variable, in this case
     ‘args.verbosity’, is given ‘None’ as a value, which is the reason
     it fails the truth test of the *note if: 181. statement.

   * The help message is a bit different.

   * When using the ‘--verbosity’ option, one must also specify some
     value, any value.

The above example accepts arbitrary integer values for ‘--verbosity’,
but for our simple program, only two values are actually useful, ‘True’
or ‘False’.  Let’s modify the code accordingly:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("--verbose", help="increase output verbosity",
                         action="store_true")
     args = parser.parse_args()
     if args.verbose:
         print("verbosity turned on")

And the output:

     $ python prog.py --verbose
     verbosity turned on
     $ python prog.py --verbose 1
     usage: prog.py [-h] [--verbose]
     prog.py: error: unrecognized arguments: 1
     $ python prog.py --help
     usage: prog.py [-h] [--verbose]

     options:
       -h, --help  show this help message and exit
       --verbose   increase output verbosity

Here is what is happening:

   * The option is now more of a flag than something that requires a
     value.  We even changed the name of the option to match that idea.
     Note that we now specify a new keyword, ‘action’, and give it the
     value ‘"store_true"’.  This means that, if the option is specified,
     assign the value ‘True’ to ‘args.verbose’.  Not specifying it
     implies ‘False’.

   * It complains when you specify a value, in true spirit of what flags
     actually are.

   * Notice the different help text.

* Menu:

* Short options::


File: python.info,  Node: Short options,  Up: Introducing Optional arguments

5.17.1.56 Short options
.......................

If you are familiar with command line usage, you will notice that I
haven’t yet touched on the topic of short versions of the options.  It’s
quite simple:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("-v", "--verbose", help="increase output verbosity",
                         action="store_true")
     args = parser.parse_args()
     if args.verbose:
         print("verbosity turned on")

And here goes:

     $ python prog.py -v
     verbosity turned on
     $ python prog.py --help
     usage: prog.py [-h] [-v]

     options:
       -h, --help     show this help message and exit
       -v, --verbose  increase output verbosity

Note that the new ability is also reflected in the help text.


File: python.info,  Node: Combining Positional and Optional arguments,  Next: Getting a little more advanced,  Prev: Introducing Optional arguments,  Up: Argparse Tutorial

5.17.1.57 Combining Positional and Optional arguments
.....................................................

Our program keeps growing in complexity:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("square", type=int,
                         help="display a square of a given number")
     parser.add_argument("-v", "--verbose", action="store_true",
                         help="increase output verbosity")
     args = parser.parse_args()
     answer = args.square**2
     if args.verbose:
         print(f"the square of {args.square} equals {answer}")
     else:
         print(answer)

And now the output:

     $ python prog.py
     usage: prog.py [-h] [-v] square
     prog.py: error: the following arguments are required: square
     $ python prog.py 4
     16
     $ python prog.py 4 --verbose
     the square of 4 equals 16
     $ python prog.py --verbose 4
     the square of 4 equals 16

   * We’ve brought back a positional argument, hence the complaint.

   * Note that the order does not matter.

How about we give this program of ours back the ability to have multiple
verbosity values, and actually get to use them:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("square", type=int,
                         help="display a square of a given number")
     parser.add_argument("-v", "--verbosity", type=int,
                         help="increase output verbosity")
     args = parser.parse_args()
     answer = args.square**2
     if args.verbosity == 2:
         print(f"the square of {args.square} equals {answer}")
     elif args.verbosity == 1:
         print(f"{args.square}^2 == {answer}")
     else:
         print(answer)

And the output:

     $ python prog.py 4
     16
     $ python prog.py 4 -v
     usage: prog.py [-h] [-v VERBOSITY] square
     prog.py: error: argument -v/--verbosity: expected one argument
     $ python prog.py 4 -v 1
     4^2 == 16
     $ python prog.py 4 -v 2
     the square of 4 equals 16
     $ python prog.py 4 -v 3
     16

These all look good except the last one, which exposes a bug in our
program.  Let’s fix it by restricting the values the ‘--verbosity’
option can accept:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("square", type=int,
                         help="display a square of a given number")
     parser.add_argument("-v", "--verbosity", type=int, choices=[0, 1, 2],
                         help="increase output verbosity")
     args = parser.parse_args()
     answer = args.square**2
     if args.verbosity == 2:
         print(f"the square of {args.square} equals {answer}")
     elif args.verbosity == 1:
         print(f"{args.square}^2 == {answer}")
     else:
         print(answer)

And the output:

     $ python prog.py 4 -v 3
     usage: prog.py [-h] [-v {0,1,2}] square
     prog.py: error: argument -v/--verbosity: invalid choice: 3 (choose from 0, 1, 2)
     $ python prog.py 4 -h
     usage: prog.py [-h] [-v {0,1,2}] square

     positional arguments:
       square                display a square of a given number

     options:
       -h, --help            show this help message and exit
       -v, --verbosity {0,1,2}
                             increase output verbosity

Note that the change also reflects both in the error message as well as
the help string.

Now, let’s use a different approach of playing with verbosity, which is
pretty common.  It also matches the way the CPython executable handles
its own verbosity argument (check the output of ‘python --help’):

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("square", type=int,
                         help="display the square of a given number")
     parser.add_argument("-v", "--verbosity", action="count",
                         help="increase output verbosity")
     args = parser.parse_args()
     answer = args.square**2
     if args.verbosity == 2:
         print(f"the square of {args.square} equals {answer}")
     elif args.verbosity == 1:
         print(f"{args.square}^2 == {answer}")
     else:
         print(answer)

We have introduced another action, «count», to count the number of
occurrences of specific options.

     $ python prog.py 4
     16
     $ python prog.py 4 -v
     4^2 == 16
     $ python prog.py 4 -vv
     the square of 4 equals 16
     $ python prog.py 4 --verbosity --verbosity
     the square of 4 equals 16
     $ python prog.py 4 -v 1
     usage: prog.py [-h] [-v] square
     prog.py: error: unrecognized arguments: 1
     $ python prog.py 4 -h
     usage: prog.py [-h] [-v] square

     positional arguments:
       square           display a square of a given number

     options:
       -h, --help       show this help message and exit
       -v, --verbosity  increase output verbosity
     $ python prog.py 4 -vvv
     16

   * Yes, it’s now more of a flag (similar to ‘action="store_true"’) in
     the previous version of our script.  That should explain the
     complaint.

   * It also behaves similar to «store_true» action.

   * Now here’s a demonstration of what the «count» action gives.
     You’ve probably seen this sort of usage before.

   * And if you don’t specify the ‘-v’ flag, that flag is considered to
     have ‘None’ value.

   * As should be expected, specifying the long form of the flag, we
     should get the same output.

   * Sadly, our help output isn’t very informative on the new ability
     our script has acquired, but that can always be fixed by improving
     the documentation for our script (e.g.  via the ‘help’ keyword
     argument).

   * That last output exposes a bug in our program.

Let’s fix:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("square", type=int,
                         help="display a square of a given number")
     parser.add_argument("-v", "--verbosity", action="count",
                         help="increase output verbosity")
     args = parser.parse_args()
     answer = args.square**2

     # bugfix: replace == with >=
     if args.verbosity >= 2:
         print(f"the square of {args.square} equals {answer}")
     elif args.verbosity >= 1:
         print(f"{args.square}^2 == {answer}")
     else:
         print(answer)

And this is what it gives:

     $ python prog.py 4 -vvv
     the square of 4 equals 16
     $ python prog.py 4 -vvvv
     the square of 4 equals 16
     $ python prog.py 4
     Traceback (most recent call last):
       File "prog.py", line 11, in <module>
         if args.verbosity >= 2:
     TypeError: '>=' not supported between instances of 'NoneType' and 'int'

   * First output went well, and fixes the bug we had before.  That is,
     we want any value >= 2 to be as verbose as possible.

   * Third output not so good.

Let’s fix that bug:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("square", type=int,
                         help="display a square of a given number")
     parser.add_argument("-v", "--verbosity", action="count", default=0,
                         help="increase output verbosity")
     args = parser.parse_args()
     answer = args.square**2
     if args.verbosity >= 2:
         print(f"the square of {args.square} equals {answer}")
     elif args.verbosity >= 1:
         print(f"{args.square}^2 == {answer}")
     else:
         print(answer)

We’ve just introduced yet another keyword, ‘default’.  We’ve set it to
‘0’ in order to make it comparable to the other int values.  Remember
that by default, if an optional argument isn’t specified, it gets the
‘None’ value, and that cannot be compared to an int value (hence the
*note TypeError: 198. exception).

And:

     $ python prog.py 4
     16

You can go quite far just with what we’ve learned so far, and we have
only scratched the surface.  The *note argparse: 7. module is very
powerful, and we’ll explore a bit more of it before we end this
tutorial.


File: python.info,  Node: Getting a little more advanced,  Next: How to translate the argparse output,  Prev: Combining Positional and Optional arguments,  Up: Argparse Tutorial

5.17.1.58 Getting a little more advanced
........................................

What if we wanted to expand our tiny program to perform other powers,
not just squares:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("x", type=int, help="the base")
     parser.add_argument("y", type=int, help="the exponent")
     parser.add_argument("-v", "--verbosity", action="count", default=0)
     args = parser.parse_args()
     answer = args.x**args.y
     if args.verbosity >= 2:
         print(f"{args.x} to the power {args.y} equals {answer}")
     elif args.verbosity >= 1:
         print(f"{args.x}^{args.y} == {answer}")
     else:
         print(answer)

Output:

     $ python prog.py
     usage: prog.py [-h] [-v] x y
     prog.py: error: the following arguments are required: x, y
     $ python prog.py -h
     usage: prog.py [-h] [-v] x y

     positional arguments:
       x                the base
       y                the exponent

     options:
       -h, --help       show this help message and exit
       -v, --verbosity
     $ python prog.py 4 2 -v
     4^2 == 16

Notice that so far we’ve been using verbosity level to 'change' the text
that gets displayed.  The following example instead uses verbosity level
to display 'more' text instead:

     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument("x", type=int, help="the base")
     parser.add_argument("y", type=int, help="the exponent")
     parser.add_argument("-v", "--verbosity", action="count", default=0)
     args = parser.parse_args()
     answer = args.x**args.y
     if args.verbosity >= 2:
         print(f"Running '{__file__}'")
     if args.verbosity >= 1:
         print(f"{args.x}^{args.y} == ", end="")
     print(answer)

Output:

     $ python prog.py 4 2
     16
     $ python prog.py 4 2 -v
     4^2 == 16
     $ python prog.py 4 2 -vv
     Running 'prog.py'
     4^2 == 16

* Menu:

* Specifying ambiguous arguments::
* Conflicting options::


File: python.info,  Node: Specifying ambiguous arguments,  Next: Conflicting options,  Up: Getting a little more advanced

5.17.1.59 Specifying ambiguous arguments
........................................

When there is ambiguity in deciding whether an argument is positional or
for an argument, ‘--’ can be used to tell *note parse_args(): 3353. that
everything after that is a positional argument:

     >>> parser = argparse.ArgumentParser(prog='PROG')
     >>> parser.add_argument('-n', nargs='+')
     >>> parser.add_argument('args', nargs='*')

     >>> # ambiguous, so parse_args assumes it's an option
     >>> parser.parse_args(['-f'])
     usage: PROG [-h] [-n N [N ...]] [args ...]
     PROG: error: unrecognized arguments: -f

     >>> parser.parse_args(['--', '-f'])
     Namespace(args=['-f'], n=None)

     >>> # ambiguous, so the -n option greedily accepts arguments
     >>> parser.parse_args(['-n', '1', '2', '3'])
     Namespace(args=[], n=['1', '2', '3'])

     >>> parser.parse_args(['-n', '1', '--', '2', '3'])
     Namespace(args=['2', '3'], n=['1'])


File: python.info,  Node: Conflicting options,  Prev: Specifying ambiguous arguments,  Up: Getting a little more advanced

5.17.1.60 Conflicting options
.............................

So far, we have been working with two methods of an *note
argparse.ArgumentParser: 1bd. instance.  Let’s introduce a third one,
*note add_mutually_exclusive_group(): 2ed.  It allows for us to specify
options that conflict with each other.  Let’s also change the rest of
the program so that the new functionality makes more sense: we’ll
introduce the ‘--quiet’ option, which will be the opposite of the
‘--verbose’ one:

     import argparse

     parser = argparse.ArgumentParser()
     group = parser.add_mutually_exclusive_group()
     group.add_argument("-v", "--verbose", action="store_true")
     group.add_argument("-q", "--quiet", action="store_true")
     parser.add_argument("x", type=int, help="the base")
     parser.add_argument("y", type=int, help="the exponent")
     args = parser.parse_args()
     answer = args.x**args.y

     if args.quiet:
         print(answer)
     elif args.verbose:
         print(f"{args.x} to the power {args.y} equals {answer}")
     else:
         print(f"{args.x}^{args.y} == {answer}")

Our program is now simpler, and we’ve lost some functionality for the
sake of demonstration.  Anyways, here’s the output:

     $ python prog.py 4 2
     4^2 == 16
     $ python prog.py 4 2 -q
     16
     $ python prog.py 4 2 -v
     4 to the power 2 equals 16
     $ python prog.py 4 2 -vq
     usage: prog.py [-h] [-v | -q] x y
     prog.py: error: argument -q/--quiet: not allowed with argument -v/--verbose
     $ python prog.py 4 2 -v --quiet
     usage: prog.py [-h] [-v | -q] x y
     prog.py: error: argument -q/--quiet: not allowed with argument -v/--verbose

That should be easy to follow.  I’ve added that last output so you can
see the sort of flexibility you get, i.e.  mixing long form options with
short form ones.

Before we conclude, you probably want to tell your users the main
purpose of your program, just in case they don’t know:

     import argparse

     parser = argparse.ArgumentParser(description="calculate X to the power of Y")
     group = parser.add_mutually_exclusive_group()
     group.add_argument("-v", "--verbose", action="store_true")
     group.add_argument("-q", "--quiet", action="store_true")
     parser.add_argument("x", type=int, help="the base")
     parser.add_argument("y", type=int, help="the exponent")
     args = parser.parse_args()
     answer = args.x**args.y

     if args.quiet:
         print(answer)
     elif args.verbose:
         print(f"{args.x} to the power {args.y} equals {answer}")
     else:
         print(f"{args.x}^{args.y} == {answer}")

Note that slight difference in the usage text.  Note the ‘[-v | -q]’,
which tells us that we can either use ‘-v’ or ‘-q’, but not both at the
same time:

     $ python prog.py --help
     usage: prog.py [-h] [-v | -q] x y

     calculate X to the power of Y

     positional arguments:
       x              the base
       y              the exponent

     options:
       -h, --help     show this help message and exit
       -v, --verbose
       -q, --quiet


File: python.info,  Node: How to translate the argparse output,  Next: Custom type converters,  Prev: Getting a little more advanced,  Up: Argparse Tutorial

5.17.1.61 How to translate the argparse output
..............................................

The output of the *note argparse: 7. module such as its help text and
error messages are all made translatable using the *note gettext: 67.
module.  This allows applications to easily localize messages produced
by *note argparse: 7.  See also *note Internationalizing your programs
and modules: 33b1.

For instance, in this *note argparse: 7. output:

     $ python prog.py --help
     usage: prog.py [-h] [-v | -q] x y

     calculate X to the power of Y

     positional arguments:
       x              the base
       y              the exponent

     options:
       -h, --help     show this help message and exit
       -v, --verbose
       -q, --quiet

The strings ‘usage:’, ‘positional arguments:’, ‘options:’ and ‘show this
help message and exit’ are all translatable.

In order to translate these strings, they must first be extracted into a
‘.po’ file.  For example, using Babel(1), run this command:

     $ pybabel extract -o messages.po /usr/lib/python3.12/argparse.py

This command will extract all translatable strings from the *note
argparse: 7. module and output them into a file named ‘messages.po’.
This command assumes that your Python installation is in ‘/usr/lib’.

You can find out the location of the *note argparse: 7. module on your
system using this script:

     import argparse
     print(argparse.__file__)

Once the messages in the ‘.po’ file are translated and the translations
are installed using *note gettext: 67, *note argparse: 7. will be able
to display the translated messages.

To translate your own strings in the *note argparse: 7. output, use
*note gettext: 67.

   ---------- Footnotes ----------

   (1) https://babel.pocoo.org/


File: python.info,  Node: Custom type converters,  Next: Conclusion,  Prev: How to translate the argparse output,  Up: Argparse Tutorial

5.17.1.62 Custom type converters
................................

The *note argparse: 7. module allows you to specify custom type
converters for your command-line arguments.  This allows you to modify
user input before it’s stored in the *note argparse.Namespace: 3354.
This can be useful when you need to pre-process the input before it is
used in your program.

When using a custom type converter, you can use any callable that takes
a single string argument (the argument value) and returns the converted
value.  However, if you need to handle more complex scenarios, you can
use a custom action class with the 'action' parameter instead.

For example, let’s say you want to handle arguments with different
prefixes and process them accordingly:

     import argparse

     parser = argparse.ArgumentParser(prefix_chars='-+')

     parser.add_argument('-a', metavar='<value>', action='append',
                         type=lambda x: ('-', x))
     parser.add_argument('+a', metavar='<value>', action='append',
                         type=lambda x: ('+', x))

     args = parser.parse_args()
     print(args)

Output:

     $ python prog.py -a value1 +a value2
     Namespace(a=[('-', 'value1'), ('+', 'value2')])

In this example, we:

   * Created a parser with custom prefix characters using the
     ‘prefix_chars’ parameter.

   * Defined two arguments, ‘-a’ and ‘+a’, which used the ‘type’
     parameter to create custom type converters to store the value in a
     tuple with the prefix.

Without the custom type converters, the arguments would have treated the
‘-a’ and ‘+a’ as the same argument, which would have been undesirable.
By using custom type converters, we were able to differentiate between
the two arguments.


File: python.info,  Node: Conclusion,  Prev: Custom type converters,  Up: Argparse Tutorial

5.17.1.63 Conclusion
....................

The *note argparse: 7. module offers a lot more than shown here.  Its
docs are quite detailed and thorough, and full of examples.  Having gone
through this tutorial, you should easily digest them without feeling
overwhelmed.


File: python.info,  Node: Migrating optparse code to argparse,  Prev: Argparse Tutorial,  Up: Exceptions<10>

5.17.1.64 Migrating ‘optparse’ code to ‘argparse’
.................................................

The *note argparse: 7. module offers several higher level features not
natively provided by the *note optparse: a4. module, including:

   * Handling positional arguments.

   * Supporting subcommands.

   * Allowing alternative option prefixes like ‘+’ and ‘/’.

   * Handling zero-or-more and one-or-more style arguments.

   * Producing more informative usage messages.

   * Providing a much simpler interface for custom ‘type’ and ‘action’.

Originally, the *note argparse: 7. module attempted to maintain
compatibility with *note optparse: a4.  However, the fundamental design
differences between supporting declarative command line option
processing (while leaving positional argument processing to application
code), and supporting both named options and positional arguments in the
declarative interface mean that the API has diverged from that of
‘optparse’ over time.

As described in *note Choosing an argument parsing library: 3351,
applications that are currently using *note optparse: a4. and are happy
with the way it works can just continue to use ‘optparse’.

Application developers that are considering migrating should also review
the list of intrinsic behavioural differences described in that section
before deciding whether or not migration is desirable.

For applications that do choose to migrate from *note optparse: a4. to
*note argparse: 7, the following suggestions should be helpful:

   * Replace all *note optparse.OptionParser.add_option(): 33b8. calls
     with *note ArgumentParser.add_argument(): 4bd. calls.

   * Replace ‘(options, args) = parser.parse_args()’ with ‘args =
     parser.parse_args()’ and add additional *note
     ArgumentParser.add_argument(): 4bd. calls for the positional
     arguments.  Keep in mind that what was previously called ‘options’,
     now in the *note argparse: 7. context is called ‘args’.

   * Replace *note optparse.OptionParser.disable_interspersed_args():
     33b9. by using *note parse_intermixed_args(): cf9. instead of *note
     parse_args(): 3353.

   * Replace callback actions and the ‘callback_*’ keyword arguments
     with ‘type’ or ‘action’ arguments.

   * Replace string names for ‘type’ keyword arguments with the
     corresponding type objects (e.g.  int, float, complex, etc).

   * Replace *note optparse.Values: 33ba. with *note Namespace: 3354.
     and *note optparse.OptionError: 33bb. and *note
     optparse.OptionValueError: 33bc. with *note ArgumentError: 33a4.

   * Replace strings with implicit arguments such as ‘%default’ or
     ‘%prog’ with the standard Python syntax to use dictionaries to
     format strings, that is, ‘%(default)s’ and ‘%(prog)s’.

   * Replace the OptionParser constructor ‘version’ argument with a call
     to ‘parser.add_argument('--version', action='version',
     version='<the version>')’.


File: python.info,  Node: optparse — Parser for command line options,  Next: getpass — Portable password input,  Prev: argparse — Parser for command-line options arguments and subcommands,  Up: Command-line interface libraries

5.17.2 ‘optparse’ — Parser for command line options
---------------------------------------------------

'Source code:' Lib/optparse.py(1)

__________________________________________________________________

* Menu:

* Choosing an argument parsing library::
* Introduction: Introduction<6>.
* Background::
* Tutorial: Tutorial<2>.
* Reference Guide::
* Option Callbacks::
* Extending optparse::
* Exceptions: Exceptions<11>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/optparse.py


File: python.info,  Node: Choosing an argument parsing library,  Next: Introduction<6>,  Up: optparse — Parser for command line options

5.17.2.1 Choosing an argument parsing library
.............................................

The standard library includes three argument parsing libraries:

   * *note getopt: 65.: a module that closely mirrors the procedural C
     ‘getopt’ API. Included in the standard library since before the
     initial Python 1.0 release.

   * *note optparse: a4.: a declarative replacement for ‘getopt’ that
     provides equivalent functionality without requiring each
     application to implement its own procedural option parsing logic.
     Included in the standard library since the Python 2.3 release.

   * *note argparse: 7.: a more opinionated alternative to ‘optparse’
     that provides more functionality by default, at the expense of
     reduced application flexibility in controlling exactly how
     arguments are processed.  Included in the standard library since
     the Python 2.7 and Python 3.2 releases.

In the absence of more specific argument parsing design constraints,
*note argparse: 7. is the recommended choice for implementing command
line applications, as it offers the highest level of baseline
functionality with the least application level code.

*note getopt: 65. is retained almost entirely for backwards
compatibility reasons.  However, it also serves a niche use case as a
tool for prototyping and testing command line argument handling in
‘getopt’-based C applications.

*note optparse: a4. should be considered as an alternative to *note
argparse: 7. in the following cases:

   * an application is already using *note optparse: a4. and doesn’t
     want to risk the subtle behavioural changes that may arise when
     migrating to *note argparse: 7.

   * the application requires additional control over the way options
     and positional parameters are interleaved on the command line
     (including the ability to disable the interleaving feature
     completely)

   * the application requires additional control over the incremental
     parsing of command line elements (while ‘argparse’ does support
     this, the exact way it works in practice is undesirable for some
     use cases)

   * the application requires additional control over the handling of
     options which accept parameter values that may start with ‘-’ (such
     as delegated options to be passed to invoked subprocesses)

   * the application requires some other command line parameter
     processing behavior which ‘argparse’ does not support, but which
     can be implemented in terms of the lower level interface offered by
     ‘optparse’

These considerations also mean that *note optparse: a4. is likely to
provide a better foundation for library authors writing third party
command line argument processing libraries.

As a concrete example, consider the following two command line argument
parsing configurations, the first using ‘optparse’, and the second using
‘argparse’:

     import optparse

     if __name__ == '__main__':
         parser = optparse.OptionParser()
         parser.add_option('-o', '--output')
         parser.add_option('-v', dest='verbose', action='store_true')
         opts, args = parser.parse_args()
         process(args, output=opts.output, verbose=opts.verbose)

     import argparse

     if __name__ == '__main__':
         parser = argparse.ArgumentParser()
         parser.add_argument('-o', '--output')
         parser.add_argument('-v', dest='verbose', action='store_true')
         parser.add_argument('rest', nargs='*')
         args = parser.parse_args()
         process(args.rest, output=args.output, verbose=args.verbose)

The most obvious difference is that in the ‘optparse’ version, the
non-option arguments are processed separately by the application after
the option processing is complete.  In the ‘argparse’ version,
positional arguments are declared and processed in the same way as the
named options.

However, the ‘argparse’ version will also handle some parameter
combination differently from the way the ‘optparse’ version would handle
them.  For example (amongst other differences):

   * supplying ‘-o -v’ gives ‘output="-v"’ and ‘verbose=False’ when
     using ‘optparse’, but a usage error with ‘argparse’ (complaining
     that no value has been supplied for ‘-o/--output’, since ‘-v’ is
     interpreted as meaning the verbosity flag)

   * similarly, supplying ‘-o --’ gives ‘output="--"’ and ‘args=()’ when
     using ‘optparse’, but a usage error with ‘argparse’ (also
     complaining that no value has been supplied for ‘-o/--output’,
     since ‘--’ is interpreted as terminating the option processing and
     treating all remaining values as positional arguments)

   * supplying ‘-o=foo’ gives ‘output="=foo"’ when using ‘optparse’, but
     gives ‘output="foo"’ with ‘argparse’ (since ‘=’ is special cased as
     an alternative separator for option parameter values)

Whether these differing behaviors in the ‘argparse’ version are
considered desirable or a problem will depend on the specific command
line application use case.

Vedi anche
..........

click(1) is a third party argument processing library (originally based
on ‘optparse’), which allows command line applications to be developed
as a set of decorated command implementation functions.

Other third party libraries, such as typer(2) or msgspec-click(3), allow
command line interfaces to be specified in ways that more effectively
integrate with static checking of Python type annotations.

   ---------- Footnotes ----------

   (1) https://pypi.org/project/click/

   (2) https://pypi.org/project/typer/

   (3) https://pypi.org/project/msgspec-click/


File: python.info,  Node: Introduction<6>,  Next: Background,  Prev: Choosing an argument parsing library,  Up: optparse — Parser for command line options

5.17.2.2 Introduction
.....................

*note optparse: a4. is a more convenient, flexible, and powerful library
for parsing command-line options than the minimalist *note getopt: 65.
module.  *note optparse: a4. uses a more declarative style of
command-line parsing: you create an instance of *note OptionParser:
16d4, populate it with options, and parse the command line.  *note
optparse: a4. allows users to specify options in the conventional
GNU/POSIX syntax, and additionally generates usage and help messages for
you.

Here’s an example of using *note optparse: a4. in a simple script:

     from optparse import OptionParser
     ...
     parser = OptionParser()
     parser.add_option("-f", "--file", dest="filename",
                       help="write report to FILE", metavar="FILE")
     parser.add_option("-q", "--quiet",
                       action="store_false", dest="verbose", default=True,
                       help="don't print status messages to stdout")

     (options, args) = parser.parse_args()

With these few lines of code, users of your script can now do the «usual
thing» on the command-line, for example:

     <yourscript> --file=outfile -q

As it parses the command line, *note optparse: a4. sets attributes of
the ‘options’ object returned by *note parse_args(): 16d5. based on
user-supplied command-line values.  When *note parse_args(): 16d5.
returns from parsing this command line, ‘options.filename’ will be
‘"outfile"’ and ‘options.verbose’ will be ‘False’.  *note optparse: a4.
supports both long and short options, allows short options to be merged
together, and allows options to be associated with their arguments in a
variety of ways.  Thus, the following command lines are all equivalent
to the above example:

     <yourscript> -f outfile --quiet
     <yourscript> --quiet --file outfile
     <yourscript> -q -foutfile
     <yourscript> -qfoutfile

Additionally, users can run one of the following

     <yourscript> -h
     <yourscript> --help

and *note optparse: a4. will print out a brief summary of your script’s
options:

     Usage: <yourscript> [options]

     Options:
       -h, --help            show this help message and exit
       -f FILE, --file=FILE  write report to FILE
       -q, --quiet           don't print status messages to stdout

where the value of 'yourscript' is determined at runtime (normally from
‘sys.argv[0]’).


File: python.info,  Node: Background,  Next: Tutorial<2>,  Prev: Introduction<6>,  Up: optparse — Parser for command line options

5.17.2.3 Background
...................

*note optparse: a4. was explicitly designed to encourage the creation of
programs with straightforward command-line interfaces that follow the
conventions established by the ‘getopt()’ family of functions available
to C developers.  To that end, it supports only the most common
command-line syntax and semantics conventionally used under Unix.  If
you are unfamiliar with these conventions, reading this section will
allow you to acquaint yourself with them.

* Menu:

* Terminology::
* What are options for?::
* What are positional arguments for?::


File: python.info,  Node: Terminology,  Next: What are options for?,  Up: Background

5.17.2.4 Terminology
....................

argument

     a string entered on the command-line, and passed by the shell to
     ‘execl()’ or ‘execv()’.  In Python, arguments are elements of
     ‘sys.argv[1:]’ (‘sys.argv[0]’ is the name of the program being
     executed).  Unix shells also use the term «word».

     It is occasionally desirable to substitute an argument list other
     than ‘sys.argv[1:]’, so you should read «argument» as «an element
     of ‘sys.argv[1:]’, or of some other list provided as a substitute
     for ‘sys.argv[1:]’».

option

     an argument used to supply extra information to guide or customize
     the execution of a program.  There are many different syntaxes for
     options; the traditional Unix syntax is a hyphen («-») followed by
     a single letter, e.g.  ‘-x’ or ‘-F’.  Also, traditional Unix syntax
     allows multiple options to be merged into a single argument, e.g.
     ‘-x -F’ is equivalent to ‘-xF’.  The GNU project introduced ‘--’
     followed by a series of hyphen-separated words, e.g.  ‘--file’ or
     ‘--dry-run’.  These are the only two option syntaxes provided by
     *note optparse: a4.

     Some other option syntaxes that the world has seen include:

        * a hyphen followed by a few letters, e.g.  ‘-pf’ (this is 'not'
          the same as multiple options merged into a single argument)

        * a hyphen followed by a whole word, e.g.  ‘-file’ (this is
          technically equivalent to the previous syntax, but they aren’t
          usually seen in the same program)

        * a plus sign followed by a single letter, or a few letters, or
          a word, e.g.  ‘+f’, ‘+rgb’

        * a slash followed by a letter, or a few letters, or a word,
          e.g.  ‘/f’, ‘/file’

     These option syntaxes are not supported by *note optparse: a4, and
     they never will be.  This is deliberate: the first three are
     non-standard on any environment, and the last only makes sense if
     you’re exclusively targeting Windows or certain legacy platforms
     (e.g.  VMS, MS-DOS).

option argument

     an argument that follows an option, is closely associated with that
     option, and is consumed from the argument list when that option is.
     With *note optparse: a4, option arguments may either be in a
     separate argument from their option:

          -f foo
          --file foo

     or included in the same argument:

          -ffoo
          --file=foo

     Typically, a given option either takes an argument or it doesn’t.
     Lots of people want an «optional option arguments» feature, meaning
     that some options will take an argument if they see it, and won’t
     if they don’t.  This is somewhat controversial, because it makes
     parsing ambiguous: if ‘-a’ takes an optional argument and ‘-b’ is
     another option entirely, how do we interpret ‘-ab’?  Because of
     this ambiguity, *note optparse: a4. does not support this feature.

positional argument

     something leftover in the argument list after options have been
     parsed, i.e.  after options and their arguments have been parsed
     and removed from the argument list.

required option

     an option that must be supplied on the command-line; note that the
     phrase «required option» is self-contradictory in English.  *note
     optparse: a4. doesn’t prevent you from implementing required
     options, but doesn’t give you much help at it either.

For example, consider this hypothetical command-line:

     prog -v --report report.txt foo bar

‘-v’ and ‘--report’ are both options.  Assuming that ‘--report’ takes
one argument, ‘report.txt’ is an option argument.  ‘foo’ and ‘bar’ are
positional arguments.


File: python.info,  Node: What are options for?,  Next: What are positional arguments for?,  Prev: Terminology,  Up: Background

5.17.2.5 What are options for?
..............................

Options are used to provide extra information to tune or customize the
execution of a program.  In case it wasn’t clear, options are usually
'optional'.  A program should be able to run just fine with no options
whatsoever.  (Pick a random program from the Unix or GNU toolsets.  Can
it run without any options at all and still make sense?  The main
exceptions are ‘find’, ‘tar’, and ‘dd’—all of which are mutant oddballs
that have been rightly criticized for their non-standard syntax and
confusing interfaces.)

Lots of people want their programs to have «required options».  Think
about it.  If it’s required, then it’s 'not optional'!  If there is a
piece of information that your program absolutely requires in order to
run successfully, that’s what positional arguments are for.

As an example of good command-line interface design, consider the humble
‘cp’ utility, for copying files.  It doesn’t make much sense to try to
copy files without supplying a destination and at least one source.
Hence, ‘cp’ fails if you run it with no arguments.  However, it has a
flexible, useful syntax that does not require any options at all:

     cp SOURCE DEST
     cp SOURCE ... DEST-DIR

You can get pretty far with just that.  Most ‘cp’ implementations
provide a bunch of options to tweak exactly how the files are copied:
you can preserve mode and modification time, avoid following symlinks,
ask before clobbering existing files, etc.  But none of this distracts
from the core mission of ‘cp’, which is to copy either one file to
another, or several files to another directory.


File: python.info,  Node: What are positional arguments for?,  Prev: What are options for?,  Up: Background

5.17.2.6 What are positional arguments for?
...........................................

Positional arguments are for those pieces of information that your
program absolutely, positively requires to run.

A good user interface should have as few absolute requirements as
possible.  If your program requires 17 distinct pieces of information in
order to run successfully, it doesn’t much matter 'how' you get that
information from the user—most people will give up and walk away before
they successfully run the program.  This applies whether the user
interface is a command-line, a configuration file, or a GUI: if you make
that many demands on your users, most of them will simply give up.

In short, try to minimize the amount of information that users are
absolutely required to supply—use sensible defaults whenever possible.
Of course, you also want to make your programs reasonably flexible.
That’s what options are for.  Again, it doesn’t matter if they are
entries in a config file, widgets in the «Preferences» dialog of a GUI,
or command-line options—the more options you implement, the more
flexible your program is, and the more complicated its implementation
becomes.  Too much flexibility has drawbacks as well, of course; too
many options can overwhelm users and make your code much harder to
maintain.


File: python.info,  Node: Tutorial<2>,  Next: Reference Guide,  Prev: Background,  Up: optparse — Parser for command line options

5.17.2.7 Tutorial
.................

While *note optparse: a4. is quite flexible and powerful, it’s also
straightforward to use in most cases.  This section covers the code
patterns that are common to any *note optparse: a4.-based program.

First, you need to import the OptionParser class; then, early in the
main program, create an OptionParser instance:

     from optparse import OptionParser
     ...
     parser = OptionParser()

Then you can start defining options.  The basic syntax is:

     parser.add_option(opt_str, ...,
                       attr=value, ...)

Each option has one or more option strings, such as ‘-f’ or ‘--file’,
and several option attributes that tell *note optparse: a4. what to
expect and what to do when it encounters that option on the command
line.

Typically, each option will have one short option string and one long
option string, e.g.:

     parser.add_option("-f", "--file", ...)

You’re free to define as many short option strings and as many long
option strings as you like (including zero), as long as there is at
least one option string overall.

The option strings passed to *note OptionParser.add_option(): 33b8. are
effectively labels for the option defined by that call.  For brevity, we
will frequently refer to 'encountering an option' on the command line;
in reality, *note optparse: a4. encounters 'option strings' and looks up
options from them.

Once all of your options are defined, instruct *note optparse: a4. to
parse your program’s command line:

     (options, args) = parser.parse_args()

(If you like, you can pass a custom argument list to *note parse_args():
16d5, but that’s rarely necessary: by default it uses ‘sys.argv[1:]’.)

*note parse_args(): 16d5. returns two values:

   * ‘options’, an object containing values for all of your options—e.g.
     if ‘--file’ takes a single string argument, then ‘options.file’
     will be the filename supplied by the user, or ‘None’ if the user
     did not supply that option

   * ‘args’, the list of positional arguments leftover after parsing
     options

This tutorial section only covers the four most important option
attributes: *note action: 33cc, *note type: 33cd, *note dest: 33ce.
(destination), and *note help: 33cf.  Of these, *note action: 33cc. is
the most fundamental.

* Menu:

* Understanding option actions::
* The store action::
* Handling boolean (flag) options: Handling boolean flag options.
* Other actions::
* Default values::
* Generating help::
* Printing a version string::
* How optparse handles errors::
* Putting it all together::


File: python.info,  Node: Understanding option actions,  Next: The store action,  Up: Tutorial<2>

5.17.2.8 Understanding option actions
.....................................

Actions tell *note optparse: a4. what to do when it encounters an option
on the command line.  There is a fixed set of actions hard-coded into
*note optparse: a4.; adding new actions is an advanced topic covered in
section *note Extending optparse: 33d2.  Most actions tell *note
optparse: a4. to store a value in some variable—for example, take a
string from the command line and store it in an attribute of ‘options’.

If you don’t specify an option action, *note optparse: a4. defaults to
‘store’.


File: python.info,  Node: The store action,  Next: Handling boolean flag options,  Prev: Understanding option actions,  Up: Tutorial<2>

5.17.2.9 The store action
.........................

The most common option action is ‘store’, which tells *note optparse:
a4. to take the next argument (or the remainder of the current
argument), ensure that it is of the correct type, and store it to your
chosen destination.

For example:

     parser.add_option("-f", "--file",
                       action="store", type="string", dest="filename")

Now let’s make up a fake command line and ask *note optparse: a4. to
parse it:

     args = ["-f", "foo.txt"]
     (options, args) = parser.parse_args(args)

When *note optparse: a4. sees the option string ‘-f’, it consumes the
next argument, ‘foo.txt’, and stores it in ‘options.filename’.  So,
after this call to *note parse_args(): 16d5, ‘options.filename’ is
‘"foo.txt"’.

Some other option types supported by *note optparse: a4. are ‘int’ and
‘float’.  Here’s an option that expects an integer argument:

     parser.add_option("-n", type="int", dest="num")

Note that this option has no long option string, which is perfectly
acceptable.  Also, there’s no explicit action, since the default is
‘store’.

Let’s parse another fake command-line.  This time, we’ll jam the option
argument right up against the option: since ‘-n42’ (one argument) is
equivalent to ‘-n 42’ (two arguments), the code

     (options, args) = parser.parse_args(["-n42"])
     print(options.num)

will print ‘42’.

If you don’t specify a type, *note optparse: a4. assumes ‘string’.
Combined with the fact that the default action is ‘store’, that means
our first example can be a lot shorter:

     parser.add_option("-f", "--file", dest="filename")

If you don’t supply a destination, *note optparse: a4. figures out a
sensible default from the option strings: if the first long option
string is ‘--foo-bar’, then the default destination is ‘foo_bar’.  If
there are no long option strings, *note optparse: a4. looks at the first
short option string: the default destination for ‘-f’ is ‘f’.

*note optparse: a4. also includes the built-in ‘complex’ type.  Adding
types is covered in section *note Extending optparse: 33d2.


File: python.info,  Node: Handling boolean flag options,  Next: Other actions,  Prev: The store action,  Up: Tutorial<2>

5.17.2.10 Handling boolean (flag) options
.........................................

Flag options—set a variable to true or false when a particular option is
seen—are quite common.  *note optparse: a4. supports them with two
separate actions, ‘store_true’ and ‘store_false’.  For example, you
might have a ‘verbose’ flag that is turned on with ‘-v’ and off with
‘-q’:

     parser.add_option("-v", action="store_true", dest="verbose")
     parser.add_option("-q", action="store_false", dest="verbose")

Here we have two different options with the same destination, which is
perfectly OK. (It just means you have to be a bit careful when setting
default values—see below.)

When *note optparse: a4. encounters ‘-v’ on the command line, it sets
‘options.verbose’ to ‘True’; when it encounters ‘-q’, ‘options.verbose’
is set to ‘False’.


File: python.info,  Node: Other actions,  Next: Default values,  Prev: Handling boolean flag options,  Up: Tutorial<2>

5.17.2.11 Other actions
.......................

Some other actions supported by *note optparse: a4. are:

‘"store_const"’

     store a constant value, pre-set via *note Option.const: 33d9.

‘"append"’

     append this option’s argument to a list

‘"count"’

     increment a counter by one

‘"callback"’

     call a specified function

These are covered in section *note Reference Guide: 33da, and section
*note Option Callbacks: 33db.


File: python.info,  Node: Default values,  Next: Generating help,  Prev: Other actions,  Up: Tutorial<2>

5.17.2.12 Default values
........................

All of the above examples involve setting some variable (the
«destination») when certain command-line options are seen.  What happens
if those options are never seen?  Since we didn’t supply any defaults,
they are all set to ‘None’.  This is usually fine, but sometimes you
want more control.  *note optparse: a4. lets you supply a default value
for each destination, which is assigned before the command line is
parsed.

First, consider the verbose/quiet example.  If we want *note optparse:
a4. to set ‘verbose’ to ‘True’ unless ‘-q’ is seen, then we can do this:

     parser.add_option("-v", action="store_true", dest="verbose", default=True)
     parser.add_option("-q", action="store_false", dest="verbose")

Since default values apply to the 'destination' rather than to any
particular option, and these two options happen to have the same
destination, this is exactly equivalent:

     parser.add_option("-v", action="store_true", dest="verbose")
     parser.add_option("-q", action="store_false", dest="verbose", default=True)

Consider this:

     parser.add_option("-v", action="store_true", dest="verbose", default=False)
     parser.add_option("-q", action="store_false", dest="verbose", default=True)

Again, the default value for ‘verbose’ will be ‘True’: the last default
value supplied for any particular destination is the one that counts.

A clearer way to specify default values is the ‘set_defaults()’ method
of OptionParser, which you can call at any time before calling *note
parse_args(): 16d5.:

     parser.set_defaults(verbose=True)
     parser.add_option(...)
     (options, args) = parser.parse_args()

As before, the last value specified for a given option destination is
the one that counts.  For clarity, try to use one method or the other of
setting default values, not both.


File: python.info,  Node: Generating help,  Next: Printing a version string,  Prev: Default values,  Up: Tutorial<2>

5.17.2.13 Generating help
.........................

*note optparse: a4.’s ability to generate help and usage text
automatically is useful for creating user-friendly command-line
interfaces.  All you have to do is supply a *note help: 33cf. value for
each option, and optionally a short usage message for your whole
program.  Here’s an OptionParser populated with user-friendly
(documented) options:

     usage = "usage: %prog [options] arg1 arg2"
     parser = OptionParser(usage=usage)
     parser.add_option("-v", "--verbose",
                       action="store_true", dest="verbose", default=True,
                       help="make lots of noise [default]")
     parser.add_option("-q", "--quiet",
                       action="store_false", dest="verbose",
                       help="be vewwy quiet (I'm hunting wabbits)")
     parser.add_option("-f", "--filename",
                       metavar="FILE", help="write output to FILE")
     parser.add_option("-m", "--mode",
                       default="intermediate",
                       help="interaction mode: novice, intermediate, "
                            "or expert [default: %default]")

If *note optparse: a4. encounters either ‘-h’ or ‘--help’ on the
command-line, or if you just call ‘parser.print_help()’, it prints the
following to standard output:

     Usage: <yourscript> [options] arg1 arg2

     Options:
       -h, --help            show this help message and exit
       -v, --verbose         make lots of noise [default]
       -q, --quiet           be vewwy quiet (I'm hunting wabbits)
       -f FILE, --filename=FILE
                             write output to FILE
       -m MODE, --mode=MODE  interaction mode: novice, intermediate, or
                             expert [default: intermediate]

(If the help output is triggered by a help option, *note optparse: a4.
exits after printing the help text.)

There’s a lot going on here to help *note optparse: a4. generate the
best possible help message:

   * the script defines its own usage message:

          usage = "usage: %prog [options] arg1 arg2"

     *note optparse: a4. expands ‘%prog’ in the usage string to the name
     of the current program, i.e.  ‘os.path.basename(sys.argv[0])’.  The
     expanded string is then printed before the detailed option help.

     If you don’t supply a usage string, *note optparse: a4. uses a
     bland but sensible default: ‘"Usage: %prog [options]"’, which is
     fine if your script doesn’t take any positional arguments.

   * every option defines a help string, and doesn’t worry about
     line-wrapping—*note optparse: a4. takes care of wrapping lines and
     making the help output look good.

   * options that take a value indicate this fact in their automatically
     generated help message, e.g.  for the «mode» option:

          -m MODE, --mode=MODE

     Here, «MODE» is called the meta-variable: it stands for the
     argument that the user is expected to supply to ‘-m’/‘--mode’.  By
     default, *note optparse: a4. converts the destination variable name
     to uppercase and uses that for the meta-variable.  Sometimes,
     that’s not what you want—for example, the ‘--filename’ option
     explicitly sets ‘metavar="FILE"’, resulting in this automatically
     generated option description:

          -f FILE, --filename=FILE

     This is important for more than just saving space, though: the
     manually written help text uses the meta-variable ‘FILE’ to clue
     the user in that there’s a connection between the semi-formal
     syntax ‘-f FILE’ and the informal semantic description «write
     output to FILE».  This is a simple but effective way to make your
     help text a lot clearer and more useful for end users.

   * options that have a default value can include ‘%default’ in the
     help string—*note optparse: a4. will replace it with *note str():
     169. of the option’s default value.  If an option has no default
     value (or the default value is ‘None’), ‘%default’ expands to
     ‘none’.

* Menu:

* Grouping Options::


File: python.info,  Node: Grouping Options,  Up: Generating help

5.17.2.14 Grouping Options
..........................

When dealing with many options, it is convenient to group these options
for better help output.  An *note OptionParser: 16d4. can contain
several option groups, each of which can contain several options.

An option group is obtained using the class *note OptionGroup: 33e1.:

 -- Classe: optparse.OptionGroup (parser, title, description=None)

     where

        * parser is the *note OptionParser: 16d4. instance the group
          will be inserted in to

        * title is the group title

        * description, optional, is a long description of the group

*note OptionGroup: 33e1. inherits from ‘OptionContainer’ (like *note
OptionParser: 16d4.) and so the ‘add_option()’ method can be used to add
an option to the group.

Once all the options are declared, using the *note OptionParser: 16d4.
method ‘add_option_group()’ the group is added to the previously defined
parser.

Continuing with the parser defined in the previous section, adding an
*note OptionGroup: 33e1. to a parser is easy:

     group = OptionGroup(parser, "Dangerous Options",
                         "Caution: use these options at your own risk.  "
                         "It is believed that some of them bite.")
     group.add_option("-g", action="store_true", help="Group option.")
     parser.add_option_group(group)

This would result in the following help output:

     Usage: <yourscript> [options] arg1 arg2

     Options:
       -h, --help            show this help message and exit
       -v, --verbose         make lots of noise [default]
       -q, --quiet           be vewwy quiet (I'm hunting wabbits)
       -f FILE, --filename=FILE
                             write output to FILE
       -m MODE, --mode=MODE  interaction mode: novice, intermediate, or
                             expert [default: intermediate]

       Dangerous Options:
         Caution: use these options at your own risk.  It is believed that some
         of them bite.

         -g                  Group option.

A bit more complete example might involve using more than one group:
still extending the previous example:

     group = OptionGroup(parser, "Dangerous Options",
                         "Caution: use these options at your own risk.  "
                         "It is believed that some of them bite.")
     group.add_option("-g", action="store_true", help="Group option.")
     parser.add_option_group(group)

     group = OptionGroup(parser, "Debug Options")
     group.add_option("-d", "--debug", action="store_true",
                      help="Print debug information")
     group.add_option("-s", "--sql", action="store_true",
                      help="Print all SQL statements executed")
     group.add_option("-e", action="store_true", help="Print every action done")
     parser.add_option_group(group)

that results in the following output:

     Usage: <yourscript> [options] arg1 arg2

     Options:
       -h, --help            show this help message and exit
       -v, --verbose         make lots of noise [default]
       -q, --quiet           be vewwy quiet (I'm hunting wabbits)
       -f FILE, --filename=FILE
                             write output to FILE
       -m MODE, --mode=MODE  interaction mode: novice, intermediate, or expert
                             [default: intermediate]

       Dangerous Options:
         Caution: use these options at your own risk.  It is believed that some
         of them bite.

         -g                  Group option.

       Debug Options:
         -d, --debug         Print debug information
         -s, --sql           Print all SQL statements executed
         -e                  Print every action done

Another interesting method, in particular when working programmatically
with option groups is:

 -- Metodo: OptionParser.get_option_group (opt_str)

     Return the *note OptionGroup: 33e1. to which the short or long
     option string 'opt_str' (e.g.  ‘'-o'’ or ‘'--option'’) belongs.  If
     there’s no such *note OptionGroup: 33e1, return ‘None’.


File: python.info,  Node: Printing a version string,  Next: How optparse handles errors,  Prev: Generating help,  Up: Tutorial<2>

5.17.2.15 Printing a version string
...................................

Similar to the brief usage string, *note optparse: a4. can also print a
version string for your program.  You have to supply the string as the
‘version’ argument to OptionParser:

     parser = OptionParser(usage="%prog [-f] [-q]", version="%prog 1.0")

‘%prog’ is expanded just like it is in ‘usage’.  Apart from that,
‘version’ can contain anything you like.  When you supply it, *note
optparse: a4. automatically adds a ‘--version’ option to your parser.
If it encounters this option on the command line, it expands your
‘version’ string (by replacing ‘%prog’), prints it to stdout, and exits.

For example, if your script is called ‘/usr/bin/foo’:

     $ /usr/bin/foo --version
     foo 1.0

The following two methods can be used to print and get the ‘version’
string:

 -- Metodo: OptionParser.print_version (file=None)

     Print the version message for the current program (‘self.version’)
     to 'file' (default stdout).  As with *note print_usage(): 33e6, any
     occurrence of ‘%prog’ in ‘self.version’ is replaced with the name
     of the current program.  Does nothing if ‘self.version’ is empty or
     undefined.

 -- Metodo: OptionParser.get_version ()

     Same as *note print_version(): 33e5. but returns the version string
     instead of printing it.


File: python.info,  Node: How optparse handles errors,  Next: Putting it all together,  Prev: Printing a version string,  Up: Tutorial<2>

5.17.2.16 How ‘optparse’ handles errors
.......................................

There are two broad classes of errors that *note optparse: a4. has to
worry about: programmer errors and user errors.  Programmer errors are
usually erroneous calls to *note OptionParser.add_option(): 33b8, e.g.
invalid option strings, unknown option attributes, missing option
attributes, etc.  These are dealt with in the usual way: raise an
exception (either *note optparse.OptionError: 33bb. or *note TypeError:
198.) and let the program crash.

Handling user errors is much more important, since they are guaranteed
to happen no matter how stable your code is.  *note optparse: a4. can
automatically detect some user errors, such as bad option arguments
(passing ‘-n 4x’ where ‘-n’ takes an integer argument), missing
arguments (‘-n’ at the end of the command line, where ‘-n’ takes an
argument of any type).  Also, you can call ‘OptionParser.error()’ to
signal an application-defined error condition:

     (options, args) = parser.parse_args()
     ...
     if options.a and options.b:
         parser.error("options -a and -b are mutually exclusive")

In either case, *note optparse: a4. handles the error the same way: it
prints the program’s usage message and an error message to standard
error and exits with error status 2.

Consider the first example above, where the user passes ‘4x’ to an
option that takes an integer:

     $ /usr/bin/foo -n 4x
     Usage: foo [options]

     foo: error: option -n: invalid integer value: '4x'

Or, where the user fails to pass a value at all:

     $ /usr/bin/foo -n
     Usage: foo [options]

     foo: error: -n option requires an argument

*note optparse: a4.-generated error messages take care always to mention
the option involved in the error; be sure to do the same when calling
‘OptionParser.error()’ from your application code.

If *note optparse: a4.’s default error-handling behaviour does not suit
your needs, you’ll need to subclass OptionParser and override its
‘exit()’ and/or ‘error()’ methods.


File: python.info,  Node: Putting it all together,  Prev: How optparse handles errors,  Up: Tutorial<2>

5.17.2.17 Putting it all together
.................................

Here’s what *note optparse: a4.-based scripts usually look like:

     from optparse import OptionParser
     ...
     def main():
         usage = "usage: %prog [options] arg"
         parser = OptionParser(usage)
         parser.add_option("-f", "--file", dest="filename",
                           help="read data from FILENAME")
         parser.add_option("-v", "--verbose",
                           action="store_true", dest="verbose")
         parser.add_option("-q", "--quiet",
                           action="store_false", dest="verbose")
         ...
         (options, args) = parser.parse_args()
         if len(args) != 1:
             parser.error("incorrect number of arguments")
         if options.verbose:
             print("reading %s..." % options.filename)
         ...

     if __name__ == "__main__":
         main()


File: python.info,  Node: Reference Guide,  Next: Option Callbacks,  Prev: Tutorial<2>,  Up: optparse — Parser for command line options

5.17.2.18 Reference Guide
.........................

* Menu:

* Creating the parser::
* Populating the parser::
* Defining options::
* Option attributes::
* Standard option actions::
* Standard option types::
* Parsing arguments::
* Querying and manipulating your option parser::
* Conflicts between options::
* Cleanup::
* Other methods::


File: python.info,  Node: Creating the parser,  Next: Populating the parser,  Up: Reference Guide

5.17.2.19 Creating the parser
.............................

The first step in using *note optparse: a4. is to create an OptionParser
instance.

 -- Classe: optparse.OptionParser (...)

     The OptionParser constructor has no required arguments, but a
     number of optional keyword arguments.  You should always pass them
     as keyword arguments, i.e.  do not rely on the order in which the
     arguments are declared.

     ‘usage’ (default: ‘"%prog [options]"’)

          The usage summary to print when your program is run
          incorrectly or with a help option.  When *note optparse: a4.
          prints the usage string, it expands ‘%prog’ to
          ‘os.path.basename(sys.argv[0])’ (or to ‘prog’ if you passed
          that keyword argument).  To suppress a usage message, pass the
          special value ‘optparse.SUPPRESS_USAGE’.

     ‘option_list’ (default: ‘[]’)

          A list of Option objects to populate the parser with.  The
          options in ‘option_list’ are added after any options in
          ‘standard_option_list’ (a class attribute that may be set by
          OptionParser subclasses), but before any version or help
          options.  Deprecated; use *note add_option(): 33b8. after
          creating the parser instead.

     ‘option_class’ (default: optparse.Option)

          Class to use when adding options to the parser in *note
          add_option(): 33b8.

     ‘version’ (default: ‘None’)

          A version string to print when the user supplies a version
          option.  If you supply a true value for ‘version’, *note
          optparse: a4. automatically adds a version option with the
          single option string ‘--version’.  The substring ‘%prog’ is
          expanded the same as for ‘usage’.

     ‘conflict_handler’ (default: ‘"error"’)

          Specifies what to do when options with conflicting option
          strings are added to the parser; see section *note Conflicts
          between options: 33ef.

     ‘description’ (default: ‘None’)

          A paragraph of text giving a brief overview of your program.
          *note optparse: a4. reformats this paragraph to fit the
          current terminal width and prints it when the user requests
          help (after ‘usage’, but before the list of options).

     ‘formatter’ (default: a new ‘IndentedHelpFormatter’)

          An instance of optparse.HelpFormatter that will be used for
          printing help text.  *note optparse: a4. provides two concrete
          classes for this purpose: IndentedHelpFormatter and
          TitledHelpFormatter.

     ‘add_help_option’ (default: ‘True’)

          If true, *note optparse: a4. will add a help option (with
          option strings ‘-h’ and ‘--help’) to the parser.

     ‘prog’

          The string to use when expanding ‘%prog’ in ‘usage’ and
          ‘version’ instead of ‘os.path.basename(sys.argv[0])’.

     ‘epilog’ (default: ‘None’)

          A paragraph of help text to print after the option help.


File: python.info,  Node: Populating the parser,  Next: Defining options,  Prev: Creating the parser,  Up: Reference Guide

5.17.2.20 Populating the parser
...............................

There are several ways to populate the parser with options.  The
preferred way is by using *note OptionParser.add_option(): 33b8, as
shown in section *note Tutorial: 33ca.  ‘add_option()’ can be called in
one of two ways:

   * pass it an Option instance (as returned by ‘make_option()’)

   * pass it any combination of positional and keyword arguments that
     are acceptable to ‘make_option()’ (i.e., to the Option
     constructor), and it will create the Option instance for you

The other alternative is to pass a list of pre-constructed Option
instances to the OptionParser constructor, as in:

     option_list = [
         make_option("-f", "--filename",
                     action="store", type="string", dest="filename"),
         make_option("-q", "--quiet",
                     action="store_false", dest="verbose"),
         ]
     parser = OptionParser(option_list=option_list)

(‘make_option()’ is a factory function for creating Option instances;
currently it is an alias for the Option constructor.  A future version
of *note optparse: a4. may split Option into several classes, and
‘make_option()’ will pick the right class to instantiate.  Do not
instantiate Option directly.)


File: python.info,  Node: Defining options,  Next: Option attributes,  Prev: Populating the parser,  Up: Reference Guide

5.17.2.21 Defining options
..........................

Each Option instance represents a set of synonymous command-line option
strings, e.g.  ‘-f’ and ‘--file’.  You can specify any number of short
or long option strings, but you must specify at least one overall option
string.

The canonical way to create an *note Option: 33f4. instance is with the
‘add_option()’ method of *note OptionParser: 16d4.

 -- Metodo: OptionParser.add_option (option)

 -- Metodo: OptionParser.add_option (*opt_str, attr=value, ...)

     To define an option with only a short option string:

          parser.add_option("-f", attr=value, ...)

     And to define an option with only a long option string:

          parser.add_option("--foo", attr=value, ...)

     The keyword arguments define attributes of the new Option object.
     The most important option attribute is *note action: 33cc, and it
     largely determines which other attributes are relevant or required.
     If you pass irrelevant option attributes, or fail to pass required
     ones, *note optparse: a4. raises an *note OptionError: 33bb.
     exception explaining your mistake.

     An option’s 'action' determines what *note optparse: a4. does when
     it encounters this option on the command-line.  The standard option
     actions hard-coded into *note optparse: a4. are:

     ‘"store"’

          store this option’s argument (default)

     ‘"store_const"’

          store a constant value, pre-set via *note Option.const: 33d9.

     ‘"store_true"’

          store ‘True’

     ‘"store_false"’

          store ‘False’

     ‘"append"’

          append this option’s argument to a list

     ‘"append_const"’

          append a constant value to a list, pre-set via *note
          Option.const: 33d9.

     ‘"count"’

          increment a counter by one

     ‘"callback"’

          call a specified function

     ‘"help"’

          print a usage message including all options and the
          documentation for them

     (If you don’t supply an action, the default is ‘"store"’.  For this
     action, you may also supply *note type: 33cd. and *note dest: 33ce.
     option attributes; see *note Standard option actions: 33f5.)

As you can see, most actions involve storing or updating a value
somewhere.  *note optparse: a4. always creates a special object for
this, conventionally called ‘options’, which is an instance of *note
optparse.Values: 33ba.

 -- Classe: optparse.Values

     An object holding parsed argument names and values as attributes.
     Normally created by calling when calling *note
     OptionParser.parse_args(): 16d5, and can be overridden by a custom
     subclass passed to the 'values' argument of *note
     OptionParser.parse_args(): 16d5. (as described in *note Parsing
     arguments: 33f6.).

Option arguments (and various other values) are stored as attributes of
this object, according to the *note dest: 33ce. (destination) option
attribute.

For example, when you call

     parser.parse_args()

one of the first things *note optparse: a4. does is create the ‘options’
object:

     options = Values()

If one of the options in this parser is defined with

     parser.add_option("-f", "--file", action="store", type="string", dest="filename")

and the command-line being parsed includes any of the following:

     -ffoo
     -f foo
     --file=foo
     --file foo

then *note optparse: a4, on seeing this option, will do the equivalent
of

     options.filename = "foo"

The *note type: 33cd. and *note dest: 33ce. option attributes are almost
as important as *note action: 33cc, but *note action: 33cc. is the only
one that makes sense for 'all' options.


File: python.info,  Node: Option attributes,  Next: Standard option actions,  Prev: Defining options,  Up: Reference Guide

5.17.2.22 Option attributes
...........................

 -- Classe: optparse.Option

     A single command line argument, with various attributes passed by
     keyword to the constructor.  Normally created with *note
     OptionParser.add_option(): 33b8. rather than directly, and can be
     overridden by a custom class via the 'option_class' argument to
     *note OptionParser: 16d4.

The following option attributes may be passed as keyword arguments to
*note OptionParser.add_option(): 33b8.  If you pass an option attribute
that is not relevant to a particular option, or fail to pass a required
option attribute, *note optparse: a4. raises *note OptionError: 33bb.

 -- Attributo: Option.action

     (default: ‘"store"’)

     Determines *note optparse: a4.’s behaviour when this option is seen
     on the command line; the available options are documented *note
     here: 33f5.

 -- Attributo: Option.type

     (default: ‘"string"’)

     The argument type expected by this option (e.g., ‘"string"’ or
     ‘"int"’); the available option types are documented *note here:
     33f9.

 -- Attributo: Option.dest

     (default: derived from option strings)

     If the option’s action implies writing or modifying a value
     somewhere, this tells *note optparse: a4. where to write it: *note
     dest: 33ce. names an attribute of the ‘options’ object that *note
     optparse: a4. builds as it parses the command line.

 -- Attributo: Option.default

     The value to use for this option’s destination if the option is not
     seen on the command line.  See also *note
     OptionParser.set_defaults(): 33fb.

 -- Attributo: Option.nargs

     (default: 1)

     How many arguments of type *note type: 33cd. should be consumed
     when this option is seen.  If > 1, *note optparse: a4. will store a
     tuple of values to *note dest: 33ce.

 -- Attributo: Option.const

     For actions that store a constant value, the constant value to
     store.

 -- Attributo: Option.choices

     For options of type ‘"choice"’, the list of strings the user may
     choose from.

 -- Attributo: Option.callback

     For options with action ‘"callback"’, the callable to call when
     this option is seen.  See section *note Option Callbacks: 33db. for
     detail on the arguments passed to the callable.

 -- Attributo: Option.callback_args
 -- Attributo: Option.callback_kwargs

     Additional positional and keyword arguments to pass to ‘callback’
     after the four standard callback arguments.

 -- Attributo: Option.help

     Help text to print for this option when listing all available
     options after the user supplies a *note help: 33cf. option (such as
     ‘--help’).  If no help text is supplied, the option will be listed
     without help text.  To hide this option, use the special value
     ‘optparse.SUPPRESS_HELP’.

 -- Attributo: Option.metavar

     (default: derived from option strings)

     Stand-in for the option argument(s) to use when printing help text.
     See section *note Tutorial: 33ca. for an example.


File: python.info,  Node: Standard option actions,  Next: Standard option types,  Prev: Option attributes,  Up: Reference Guide

5.17.2.23 Standard option actions
.................................

The various option actions all have slightly different requirements and
effects.  Most actions have several relevant option attributes which you
may specify to guide *note optparse: a4.’s behaviour; a few have
required attributes, which you must specify for any option using that
action.

   * ‘"store"’ [relevant: *note type: 33cd, *note dest: 33ce, *note
     nargs: 33fc, *note choices: 33fd.]

     The option must be followed by an argument, which is converted to a
     value according to *note type: 33cd. and stored in *note dest:
     33ce.  If *note nargs: 33fc. > 1, multiple arguments will be
     consumed from the command line; all will be converted according to
     *note type: 33cd. and stored to *note dest: 33ce. as a tuple.  See
     the *note Standard option types: 33f9. section.

     If *note choices: 33fd. is supplied (a list or tuple of strings),
     the type defaults to ‘"choice"’.

     If *note type: 33cd. is not supplied, it defaults to ‘"string"’.

     If *note dest: 33ce. is not supplied, *note optparse: a4. derives a
     destination from the first long option string (e.g., ‘--foo-bar’
     implies ‘foo_bar’).  If there are no long option strings, *note
     optparse: a4. derives a destination from the first short option
     string (e.g., ‘-f’ implies ‘f’).

     Example:

          parser.add_option("-f")
          parser.add_option("-p", type="float", nargs=3, dest="point")

     As it parses the command line

          -f foo.txt -p 1 -3.5 4 -fbar.txt

     *note optparse: a4. will set

          options.f = "foo.txt"
          options.point = (1.0, -3.5, 4.0)
          options.f = "bar.txt"

   * ‘"store_const"’ [required: *note const: 33d9.; relevant: *note
     dest: 33ce.]

     The value *note const: 33d9. is stored in *note dest: 33ce.

     Example:

          parser.add_option("-q", "--quiet",
                            action="store_const", const=0, dest="verbose")
          parser.add_option("-v", "--verbose",
                            action="store_const", const=1, dest="verbose")
          parser.add_option("--noisy",
                            action="store_const", const=2, dest="verbose")

     If ‘--noisy’ is seen, *note optparse: a4. will set

          options.verbose = 2

   * ‘"store_true"’ [relevant: *note dest: 33ce.]

     A special case of ‘"store_const"’ that stores ‘True’ to *note dest:
     33ce.

   * ‘"store_false"’ [relevant: *note dest: 33ce.]

     Like ‘"store_true"’, but stores ‘False’.

     Example:

          parser.add_option("--clobber", action="store_true", dest="clobber")
          parser.add_option("--no-clobber", action="store_false", dest="clobber")

   * ‘"append"’ [relevant: *note type: 33cd, *note dest: 33ce, *note
     nargs: 33fc, *note choices: 33fd.]

     The option must be followed by an argument, which is appended to
     the list in *note dest: 33ce.  If no default value for *note dest:
     33ce. is supplied, an empty list is automatically created when
     *note optparse: a4. first encounters this option on the
     command-line.  If *note nargs: 33fc. > 1, multiple arguments are
     consumed, and a tuple of length *note nargs: 33fc. is appended to
     *note dest: 33ce.

     The defaults for *note type: 33cd. and *note dest: 33ce. are the
     same as for the ‘"store"’ action.

     Example:

          parser.add_option("-t", "--tracks", action="append", type="int")

     If ‘-t3’ is seen on the command-line, *note optparse: a4. does the
     equivalent of:

          options.tracks = []
          options.tracks.append(int("3"))

     If, a little later on, ‘--tracks=4’ is seen, it does:

          options.tracks.append(int("4"))

     The ‘append’ action calls the ‘append’ method on the current value
     of the option.  This means that any default value specified must
     have an ‘append’ method.  It also means that if the default value
     is non-empty, the default elements will be present in the parsed
     value for the option, with any values from the command line
     appended after those default values:

          >>> parser.add_option("--files", action="append", default=['~/.mypkg/defaults'])
          >>> opts, args = parser.parse_args(['--files', 'overrides.mypkg'])
          >>> opts.files
          ['~/.mypkg/defaults', 'overrides.mypkg']

   * ‘"append_const"’ [required: *note const: 33d9.; relevant: *note
     dest: 33ce.]

     Like ‘"store_const"’, but the value *note const: 33d9. is appended
     to *note dest: 33ce.; as with ‘"append"’, *note dest: 33ce.
     defaults to ‘None’, and an empty list is automatically created the
     first time the option is encountered.

   * ‘"count"’ [relevant: *note dest: 33ce.]

     Increment the integer stored at *note dest: 33ce.  If no default
     value is supplied, *note dest: 33ce. is set to zero before being
     incremented the first time.

     Example:

          parser.add_option("-v", action="count", dest="verbosity")

     The first time ‘-v’ is seen on the command line, *note optparse:
     a4. does the equivalent of:

          options.verbosity = 0
          options.verbosity += 1

     Every subsequent occurrence of ‘-v’ results in

          options.verbosity += 1

   * ‘"callback"’ [required: *note callback: 33fe.; relevant: *note
     type: 33cd, *note nargs: 33fc, *note callback_args: 33ff, *note
     callback_kwargs: 3400.]

     Call the function specified by *note callback: 33fe, which is
     called as

          func(option, opt_str, value, parser, *args, **kwargs)

     See section *note Option Callbacks: 33db. for more detail.

   * ‘"help"’

     Prints a complete help message for all the options in the current
     option parser.  The help message is constructed from the ‘usage’
     string passed to OptionParser’s constructor and the *note help:
     33cf. string passed to every option.

     If no *note help: 33cf. string is supplied for an option, it will
     still be listed in the help message.  To omit an option entirely,
     use the special value ‘optparse.SUPPRESS_HELP’.

     *note optparse: a4. automatically adds a *note help: 33cf. option
     to all OptionParsers, so you do not normally need to create one.

     Example:

          from optparse import OptionParser, SUPPRESS_HELP

          # usually, a help option is added automatically, but that can
          # be suppressed using the add_help_option argument
          parser = OptionParser(add_help_option=False)

          parser.add_option("-h", "--help", action="help")
          parser.add_option("-v", action="store_true", dest="verbose",
                            help="Be moderately verbose")
          parser.add_option("--file", dest="filename",
                            help="Input file to read data from")
          parser.add_option("--secret", help=SUPPRESS_HELP)

     If *note optparse: a4. sees either ‘-h’ or ‘--help’ on the command
     line, it will print something like the following help message to
     stdout (assuming ‘sys.argv[0]’ is ‘"foo.py"’):

          Usage: foo.py [options]

          Options:
            -h, --help        Show this help message and exit
            -v                Be moderately verbose
            --file=FILENAME   Input file to read data from

     After printing the help message, *note optparse: a4. terminates
     your process with ‘sys.exit(0)’.

   * ‘"version"’

     Prints the version number supplied to the OptionParser to stdout
     and exits.  The version number is actually formatted and printed by
     the ‘print_version()’ method of OptionParser.  Generally only
     relevant if the ‘version’ argument is supplied to the OptionParser
     constructor.  As with *note help: 33cf. options, you will rarely
     create ‘version’ options, since *note optparse: a4. automatically
     adds them when needed.


File: python.info,  Node: Standard option types,  Next: Parsing arguments,  Prev: Standard option actions,  Up: Reference Guide

5.17.2.24 Standard option types
...............................

*note optparse: a4. has five built-in option types: ‘"string"’, ‘"int"’,
‘"choice"’, ‘"float"’ and ‘"complex"’.  If you need to add new option
types, see section *note Extending optparse: 33d2.

Arguments to string options are not checked or converted in any way: the
text on the command line is stored in the destination (or passed to the
callback) as-is.

Integer arguments (type ‘"int"’) are parsed as follows:

   * if the number starts with ‘0x’, it is parsed as a hexadecimal
     number

   * if the number starts with ‘0’, it is parsed as an octal number

   * if the number starts with ‘0b’, it is parsed as a binary number

   * otherwise, the number is parsed as a decimal number

The conversion is done by calling *note int(): 19b. with the appropriate
base (2, 8, 10, or 16).  If this fails, so will *note optparse: a4,
although with a more useful error message.

‘"float"’ and ‘"complex"’ option arguments are converted directly with
*note float(): 196. and *note complex(): 197, with similar
error-handling.

‘"choice"’ options are a subtype of ‘"string"’ options.  The *note
choices: 33fd. option attribute (a sequence of strings) defines the set
of allowed option arguments.  ‘optparse.check_choice()’ compares
user-supplied option arguments against this master list and raises *note
OptionValueError: 33bc. if an invalid string is given.


File: python.info,  Node: Parsing arguments,  Next: Querying and manipulating your option parser,  Prev: Standard option types,  Up: Reference Guide

5.17.2.25 Parsing arguments
...........................

The whole point of creating and populating an OptionParser is to call
its *note parse_args(): 16d5. method.

 -- Metodo: OptionParser.parse_args (args=None, values=None)

     Parse the command-line options found in 'args'.

     The input parameters are

     ‘args’

          the list of arguments to process (default: ‘sys.argv[1:]’)

     ‘values’

          a *note Values: 33ba. object to store option arguments in
          (default: a new instance of *note Values: 33ba.) – if you give
          an existing object, the option defaults will not be
          initialized on it

     and the return value is a pair ‘(options, args)’ where

     ‘options’

          the same object that was passed in as 'values', or the
          ‘optparse.Values’ instance created by *note optparse: a4.

     ‘args’

          the leftover positional arguments after all options have been
          processed

The most common usage is to supply neither keyword argument.  If you
supply ‘values’, it will be modified with repeated *note setattr():
259a. calls (roughly one for every option argument stored to an option
destination) and returned by *note parse_args(): 16d5.

If *note parse_args(): 16d5. encounters any errors in the argument list,
it calls the OptionParser’s ‘error()’ method with an appropriate
end-user error message.  This ultimately terminates your process with an
exit status of 2 (the traditional Unix exit status for command-line
errors).


File: python.info,  Node: Querying and manipulating your option parser,  Next: Conflicts between options,  Prev: Parsing arguments,  Up: Reference Guide

5.17.2.26 Querying and manipulating your option parser
......................................................

The default behavior of the option parser can be customized slightly,
and you can also poke around your option parser and see what’s there.
OptionParser provides several methods to help you out:

 -- Metodo: OptionParser.disable_interspersed_args ()

     Set parsing to stop on the first non-option.  For example, if ‘-a’
     and ‘-b’ are both simple options that take no arguments, *note
     optparse: a4. normally accepts this syntax:

          prog -a arg1 -b arg2

     and treats it as equivalent to

          prog -a -b arg1 arg2

     To disable this feature, call *note disable_interspersed_args():
     33b9.  This restores traditional Unix syntax, where option parsing
     stops with the first non-option argument.

     Use this if you have a command processor which runs another command
     which has options of its own and you want to make sure these
     options don’t get confused.  For example, each command might have a
     different set of options.

 -- Metodo: OptionParser.enable_interspersed_args ()

     Set parsing to not stop on the first non-option, allowing
     interspersing switches with command arguments.  This is the default
     behavior.

 -- Metodo: OptionParser.get_option (opt_str)

     Returns the Option instance with the option string 'opt_str', or
     ‘None’ if no options have that option string.

 -- Metodo: OptionParser.has_option (opt_str)

     Return ‘True’ if the OptionParser has an option with option string
     'opt_str' (e.g., ‘-q’ or ‘--verbose’).

 -- Metodo: OptionParser.remove_option (opt_str)

     If the *note OptionParser: 16d4. has an option corresponding to
     'opt_str', that option is removed.  If that option provided any
     other option strings, all of those option strings become invalid.
     If 'opt_str' does not occur in any option belonging to this *note
     OptionParser: 16d4, raises *note ValueError: 2ec.


File: python.info,  Node: Conflicts between options,  Next: Cleanup,  Prev: Querying and manipulating your option parser,  Up: Reference Guide

5.17.2.27 Conflicts between options
...................................

If you’re not careful, it’s easy to define options with conflicting
option strings:

     parser.add_option("-n", "--dry-run", ...)
     ...
     parser.add_option("-n", "--noisy", ...)

(This is particularly true if you’ve defined your own OptionParser
subclass with some standard options.)

Every time you add an option, *note optparse: a4. checks for conflicts
with existing options.  If it finds any, it invokes the current
conflict-handling mechanism.  You can set the conflict-handling
mechanism either in the constructor:

     parser = OptionParser(..., conflict_handler=handler)

or with a separate call:

     parser.set_conflict_handler(handler)

The available conflict handlers are:

     ‘"error"’ (default)

          assume option conflicts are a programming error and raise
          *note OptionConflictError: 340c.

     ‘"resolve"’

          resolve option conflicts intelligently (see below)

As an example, let’s define an *note OptionParser: 16d4. that resolves
conflicts intelligently and add conflicting options to it:

     parser = OptionParser(conflict_handler="resolve")
     parser.add_option("-n", "--dry-run", ..., help="do no harm")
     parser.add_option("-n", "--noisy", ..., help="be noisy")

At this point, *note optparse: a4. detects that a previously added
option is already using the ‘-n’ option string.  Since
‘conflict_handler’ is ‘"resolve"’, it resolves the situation by removing
‘-n’ from the earlier option’s list of option strings.  Now ‘--dry-run’
is the only way for the user to activate that option.  If the user asks
for help, the help message will reflect that:

     Options:
       --dry-run     do no harm
       ...
       -n, --noisy   be noisy

It’s possible to whittle away the option strings for a previously added
option until there are none left, and the user has no way of invoking
that option from the command-line.  In that case, *note optparse: a4.
removes that option completely, so it doesn’t show up in help text or
anywhere else.  Carrying on with our existing OptionParser:

     parser.add_option("--dry-run", ..., help="new dry-run option")

At this point, the original ‘-n’/‘--dry-run’ option is no longer
accessible, so *note optparse: a4. removes it, leaving this help text:

     Options:
       ...
       -n, --noisy   be noisy
       --dry-run     new dry-run option


File: python.info,  Node: Cleanup,  Next: Other methods,  Prev: Conflicts between options,  Up: Reference Guide

5.17.2.28 Cleanup
.................

OptionParser instances have several cyclic references.  This should not
be a problem for Python’s garbage collector, but you may wish to break
the cyclic references explicitly by calling ‘destroy()’ on your
OptionParser once you are done with it.  This is particularly useful in
long-running applications where large object graphs are reachable from
your OptionParser.


File: python.info,  Node: Other methods,  Prev: Cleanup,  Up: Reference Guide

5.17.2.29 Other methods
.......................

OptionParser supports several other public methods:

 -- Metodo: OptionParser.set_usage (usage)

     Set the usage string according to the rules described above for the
     ‘usage’ constructor keyword argument.  Passing ‘None’ sets the
     default usage string; use ‘optparse.SUPPRESS_USAGE’ to suppress a
     usage message.

 -- Metodo: OptionParser.print_usage (file=None)

     Print the usage message for the current program (‘self.usage’) to
     'file' (default stdout).  Any occurrence of the string ‘%prog’ in
     ‘self.usage’ is replaced with the name of the current program.
     Does nothing if ‘self.usage’ is empty or not defined.

 -- Metodo: OptionParser.get_usage ()

     Same as *note print_usage(): 33e6. but returns the usage string
     instead of printing it.

 -- Metodo: OptionParser.set_defaults (dest=value, ...)

     Set default values for several option destinations at once.  Using
     *note set_defaults(): 33fb. is the preferred way to set default
     values for options, since multiple options can share the same
     destination.  For example, if several «mode» options all set the
     same destination, any one of them can set the default, and the last
     one wins:

          parser.add_option("--advanced", action="store_const",
                            dest="mode", const="advanced",
                            default="novice")    # overridden below
          parser.add_option("--novice", action="store_const",
                            dest="mode", const="novice",
                            default="advanced")  # overrides above setting

     To avoid this confusion, use *note set_defaults(): 33fb.:

          parser.set_defaults(mode="advanced")
          parser.add_option("--advanced", action="store_const",
                            dest="mode", const="advanced")
          parser.add_option("--novice", action="store_const",
                            dest="mode", const="novice")


File: python.info,  Node: Option Callbacks,  Next: Extending optparse,  Prev: Reference Guide,  Up: optparse — Parser for command line options

5.17.2.30 Option Callbacks
..........................

When *note optparse: a4.’s built-in actions and types aren’t quite
enough for your needs, you have two choices: extend *note optparse: a4.
or define a callback option.  Extending *note optparse: a4. is more
general, but overkill for a lot of simple cases.  Quite often a simple
callback is all you need.

There are two steps to defining a callback option:

   * define the option itself using the ‘"callback"’ action

   * write the callback; this is a function (or method) that takes at
     least four arguments, as described below

* Menu:

* Defining a callback option::
* How callbacks are called::
* Raising errors in a callback::
* Callback example 1; trivial callback: Callback example 1 trivial callback.
* Callback example 2; check option order: Callback example 2 check option order.
* Callback example 3; check option order (generalized): Callback example 3 check option order generalized.
* Callback example 4; check arbitrary condition: Callback example 4 check arbitrary condition.
* Callback example 5; fixed arguments: Callback example 5 fixed arguments.
* Callback example 6; variable arguments: Callback example 6 variable arguments.


File: python.info,  Node: Defining a callback option,  Next: How callbacks are called,  Up: Option Callbacks

5.17.2.31 Defining a callback option
....................................

As always, the easiest way to define a callback option is by using the
*note OptionParser.add_option(): 33b8. method.  Apart from *note action:
33cc, the only option attribute you must specify is ‘callback’, the
function to call:

     parser.add_option("-c", action="callback", callback=my_callback)

‘callback’ is a function (or other callable object), so you must have
already defined ‘my_callback()’ when you create this callback option.
In this simple case, *note optparse: a4. doesn’t even know if ‘-c’ takes
any arguments, which usually means that the option takes no
arguments—the mere presence of ‘-c’ on the command-line is all it needs
to know.  In some circumstances, though, you might want your callback to
consume an arbitrary number of command-line arguments.  This is where
writing callbacks gets tricky; it’s covered later in this section.

*note optparse: a4. always passes four particular arguments to your
callback, and it will only pass additional arguments if you specify them
via *note callback_args: 33ff. and *note callback_kwargs: 3400.  Thus,
the minimal callback function signature is:

     def my_callback(option, opt, value, parser):

The four arguments to a callback are described below.

There are several other option attributes that you can supply when you
define a callback option:

*note type: 33cd.

     has its usual meaning: as with the ‘"store"’ or ‘"append"’ actions,
     it instructs *note optparse: a4. to consume one argument and
     convert it to *note type: 33cd.  Rather than storing the converted
     value(s) anywhere, though, *note optparse: a4. passes it to your
     callback function.

*note nargs: 33fc.

     also has its usual meaning: if it is supplied and > 1, *note
     optparse: a4. will consume *note nargs: 33fc. arguments, each of
     which must be convertible to *note type: 33cd.  It then passes a
     tuple of converted values to your callback.

*note callback_args: 33ff.

     a tuple of extra positional arguments to pass to the callback

*note callback_kwargs: 3400.

     a dictionary of extra keyword arguments to pass to the callback


File: python.info,  Node: How callbacks are called,  Next: Raising errors in a callback,  Prev: Defining a callback option,  Up: Option Callbacks

5.17.2.32 How callbacks are called
..................................

All callbacks are called as follows:

     func(option, opt_str, value, parser, *args, **kwargs)

where

‘option’

     is the Option instance that’s calling the callback

‘opt_str’

     is the option string seen on the command-line that’s triggering the
     callback.  (If an abbreviated long option was used, ‘opt_str’ will
     be the full, canonical option string—e.g.  if the user puts ‘--foo’
     on the command-line as an abbreviation for ‘--foobar’, then
     ‘opt_str’ will be ‘"--foobar"’.)

‘value’

     is the argument to this option seen on the command-line.  *note
     optparse: a4. will only expect an argument if *note type: 33cd. is
     set; the type of ‘value’ will be the type implied by the option’s
     type.  If *note type: 33cd. for this option is ‘None’ (no argument
     expected), then ‘value’ will be ‘None’.  If *note nargs: 33fc. > 1,
     ‘value’ will be a tuple of values of the appropriate type.

‘parser’

     is the OptionParser instance driving the whole thing, mainly useful
     because you can access some other interesting data through its
     instance attributes:

     ‘parser.largs’

          the current list of leftover arguments, ie.  arguments that
          have been consumed but are neither options nor option
          arguments.  Feel free to modify ‘parser.largs’, e.g.  by
          adding more arguments to it.  (This list will become ‘args’,
          the second return value of *note parse_args(): 16d5.)

     ‘parser.rargs’

          the current list of remaining arguments, ie.  with ‘opt_str’
          and ‘value’ (if applicable) removed, and only the arguments
          following them still there.  Feel free to modify
          ‘parser.rargs’, e.g.  by consuming more arguments.

     ‘parser.values’

          the object where option values are by default stored (an
          instance of optparse.OptionValues).  This lets callbacks use
          the same mechanism as the rest of *note optparse: a4. for
          storing option values; you don’t need to mess around with
          globals or closures.  You can also access or modify the
          value(s) of any options already encountered on the
          command-line.

‘args’

     is a tuple of arbitrary positional arguments supplied via the *note
     callback_args: 33ff. option attribute.

‘kwargs’

     is a dictionary of arbitrary keyword arguments supplied via *note
     callback_kwargs: 3400.


File: python.info,  Node: Raising errors in a callback,  Next: Callback example 1 trivial callback,  Prev: How callbacks are called,  Up: Option Callbacks

5.17.2.33 Raising errors in a callback
......................................

The callback function should raise *note OptionValueError: 33bc. if
there are any problems with the option or its argument(s).  *note
optparse: a4. catches this and terminates the program, printing the
error message you supply to stderr.  Your message should be clear,
concise, accurate, and mention the option at fault.  Otherwise, the user
will have a hard time figuring out what they did wrong.


File: python.info,  Node: Callback example 1 trivial callback,  Next: Callback example 2 check option order,  Prev: Raising errors in a callback,  Up: Option Callbacks

5.17.2.34 Callback example 1: trivial callback
..............................................

Here’s an example of a callback option that takes no arguments, and
simply records that the option was seen:

     def record_foo_seen(option, opt_str, value, parser):
         parser.values.saw_foo = True

     parser.add_option("--foo", action="callback", callback=record_foo_seen)

Of course, you could do that with the ‘"store_true"’ action.


File: python.info,  Node: Callback example 2 check option order,  Next: Callback example 3 check option order generalized,  Prev: Callback example 1 trivial callback,  Up: Option Callbacks

5.17.2.35 Callback example 2: check option order
................................................

Here’s a slightly more interesting example: record the fact that ‘-a’ is
seen, but blow up if it comes after ‘-b’ in the command-line.

     def check_order(option, opt_str, value, parser):
         if parser.values.b:
             raise OptionValueError("can't use -a after -b")
         parser.values.a = 1
     ...
     parser.add_option("-a", action="callback", callback=check_order)
     parser.add_option("-b", action="store_true", dest="b")


File: python.info,  Node: Callback example 3 check option order generalized,  Next: Callback example 4 check arbitrary condition,  Prev: Callback example 2 check option order,  Up: Option Callbacks

5.17.2.36 Callback example 3: check option order (generalized)
..............................................................

If you want to reuse this callback for several similar options (set a
flag, but blow up if ‘-b’ has already been seen), it needs a bit of
work: the error message and the flag that it sets must be generalized.

     def check_order(option, opt_str, value, parser):
         if parser.values.b:
             raise OptionValueError("can't use %s after -b" % opt_str)
         setattr(parser.values, option.dest, 1)
     ...
     parser.add_option("-a", action="callback", callback=check_order, dest='a')
     parser.add_option("-b", action="store_true", dest="b")
     parser.add_option("-c", action="callback", callback=check_order, dest='c')


File: python.info,  Node: Callback example 4 check arbitrary condition,  Next: Callback example 5 fixed arguments,  Prev: Callback example 3 check option order generalized,  Up: Option Callbacks

5.17.2.37 Callback example 4: check arbitrary condition
.......................................................

Of course, you could put any condition in there—you’re not limited to
checking the values of already-defined options.  For example, if you
have options that should not be called when the moon is full, all you
have to do is this:

     def check_moon(option, opt_str, value, parser):
         if is_moon_full():
             raise OptionValueError("%s option invalid when moon is full"
                                    % opt_str)
         setattr(parser.values, option.dest, 1)
     ...
     parser.add_option("--foo",
                       action="callback", callback=check_moon, dest="foo")

(The definition of ‘is_moon_full()’ is left as an exercise for the
reader.)


File: python.info,  Node: Callback example 5 fixed arguments,  Next: Callback example 6 variable arguments,  Prev: Callback example 4 check arbitrary condition,  Up: Option Callbacks

5.17.2.38 Callback example 5: fixed arguments
.............................................

Things get slightly more interesting when you define callback options
that take a fixed number of arguments.  Specifying that a callback
option takes arguments is similar to defining a ‘"store"’ or ‘"append"’
option: if you define *note type: 33cd, then the option takes one
argument that must be convertible to that type; if you further define
*note nargs: 33fc, then the option takes *note nargs: 33fc. arguments.

Here’s an example that just emulates the standard ‘"store"’ action:

     def store_value(option, opt_str, value, parser):
         setattr(parser.values, option.dest, value)
     ...
     parser.add_option("--foo",
                       action="callback", callback=store_value,
                       type="int", nargs=3, dest="foo")

Note that *note optparse: a4. takes care of consuming 3 arguments and
converting them to integers for you; all you have to do is store them.
(Or whatever; obviously you don’t need a callback for this example.)


File: python.info,  Node: Callback example 6 variable arguments,  Prev: Callback example 5 fixed arguments,  Up: Option Callbacks

5.17.2.39 Callback example 6: variable arguments
................................................

Things get hairy when you want an option to take a variable number of
arguments.  For this case, you must write a callback, as *note optparse:
a4. doesn’t provide any built-in capabilities for it.  And you have to
deal with certain intricacies of conventional Unix command-line parsing
that *note optparse: a4. normally handles for you.  In particular,
callbacks should implement the conventional rules for bare ‘--’ and ‘-’
arguments:

   * either ‘--’ or ‘-’ can be option arguments

   * bare ‘--’ (if not the argument to some option): halt command-line
     processing and discard the ‘--’

   * bare ‘-’ (if not the argument to some option): halt command-line
     processing but keep the ‘-’ (append it to ‘parser.largs’)

If you want an option that takes a variable number of arguments, there
are several subtle, tricky issues to worry about.  The exact
implementation you choose will be based on which trade-offs you’re
willing to make for your application (which is why *note optparse: a4.
doesn’t support this sort of thing directly).

Nevertheless, here’s a stab at a callback for an option with variable
arguments:

     def vararg_callback(option, opt_str, value, parser):
         assert value is None
         value = []

         def floatable(str):
             try:
                 float(str)
                 return True
             except ValueError:
                 return False

         for arg in parser.rargs:
             # stop on --foo like options
             if arg[:2] == "--" and len(arg) > 2:
                 break
             # stop on -a, but not on -3 or -3.0
             if arg[:1] == "-" and len(arg) > 1 and not floatable(arg):
                 break
             value.append(arg)

         del parser.rargs[:len(value)]
         setattr(parser.values, option.dest, value)

     ...
     parser.add_option("-c", "--callback", dest="vararg_attr",
                       action="callback", callback=vararg_callback)


File: python.info,  Node: Extending optparse,  Next: Exceptions<11>,  Prev: Option Callbacks,  Up: optparse — Parser for command line options

5.17.2.40 Extending ‘optparse’
..............................

Since the two major controlling factors in how *note optparse: a4.
interprets command-line options are the action and type of each option,
the most likely direction of extension is to add new actions and new
types.

* Menu:

* Adding new types::
* Adding new actions::


File: python.info,  Node: Adding new types,  Next: Adding new actions,  Up: Extending optparse

5.17.2.41 Adding new types
..........................

To add new types, you need to define your own subclass of *note
optparse: a4.’s *note Option: 33f4. class.  This class has a couple of
attributes that define *note optparse: a4.’s types: *note TYPES: 3429.
and *note TYPE_CHECKER: 342a.

 -- Attributo: Option.TYPES

     A tuple of type names; in your subclass, simply define a new tuple
     *note TYPES: 3429. that builds on the standard one.

 -- Attributo: Option.TYPE_CHECKER

     A dictionary mapping type names to type-checking functions.  A
     type-checking function has the following signature:

          def check_mytype(option, opt, value)

     where ‘option’ is an *note Option: 33f4. instance, ‘opt’ is an
     option string (e.g., ‘-f’), and ‘value’ is the string from the
     command line that must be checked and converted to your desired
     type.  ‘check_mytype()’ should return an object of the hypothetical
     type ‘mytype’.  The value returned by a type-checking function will
     wind up in the OptionValues instance returned by *note
     OptionParser.parse_args(): 16d5, or be passed to a callback as the
     ‘value’ parameter.

     Your type-checking function should raise *note OptionValueError:
     33bc. if it encounters any problems.  *note OptionValueError: 33bc.
     takes a single string argument, which is passed as-is to *note
     OptionParser: 16d4.’s ‘error()’ method, which in turn prepends the
     program name and the string ‘"error:"’ and prints everything to
     stderr before terminating the process.

Here’s a silly example that demonstrates adding a ‘"complex"’ option
type to parse Python-style complex numbers on the command line.  (This
is even sillier than it used to be, because *note optparse: a4. 1.3
added built-in support for complex numbers, but never mind.)

First, the necessary imports:

     from copy import copy
     from optparse import Option, OptionValueError

You need to define your type-checker first, since it’s referred to later
(in the *note TYPE_CHECKER: 342a. class attribute of your Option
subclass):

     def check_complex(option, opt, value):
         try:
             return complex(value)
         except ValueError:
             raise OptionValueError(
                 "option %s: invalid complex value: %r" % (opt, value))

Finally, the Option subclass:

     class MyOption (Option):
         TYPES = Option.TYPES + ("complex",)
         TYPE_CHECKER = copy(Option.TYPE_CHECKER)
         TYPE_CHECKER["complex"] = check_complex

(If we didn’t make a *note copy(): 29. of *note Option.TYPE_CHECKER:
342a, we would end up modifying the *note TYPE_CHECKER: 342a. attribute
of *note optparse: a4.’s Option class.  This being Python, nothing stops
you from doing that except good manners and common sense.)

That’s it!  Now you can write a script that uses the new option type
just like any other *note optparse: a4.-based script, except you have to
instruct your OptionParser to use MyOption instead of Option:

     parser = OptionParser(option_class=MyOption)
     parser.add_option("-c", type="complex")

Alternately, you can build your own option list and pass it to
OptionParser; if you don’t use ‘add_option()’ in the above way, you
don’t need to tell OptionParser which option class to use:

     option_list = [MyOption("-c", action="store", type="complex", dest="c")]
     parser = OptionParser(option_list=option_list)


File: python.info,  Node: Adding new actions,  Prev: Adding new types,  Up: Extending optparse

5.17.2.42 Adding new actions
............................

Adding new actions is a bit trickier, because you have to understand
that *note optparse: a4. has a couple of classifications for actions:

«store» actions

     actions that result in *note optparse: a4. storing a value to an
     attribute of the current OptionValues instance; these options
     require a *note dest: 33ce. attribute to be supplied to the Option
     constructor.

«typed» actions

     actions that take a value from the command line and expect it to be
     of a certain type; or rather, a string that can be converted to a
     certain type.  These options require a *note type: 33cd. attribute
     to the Option constructor.

These are overlapping sets: some default «store» actions are ‘"store"’,
‘"store_const"’, ‘"append"’, and ‘"count"’, while the default «typed»
actions are ‘"store"’, ‘"append"’, and ‘"callback"’.

When you add an action, you need to categorize it by listing it in at
least one of the following class attributes of Option (all are lists of
strings):

 -- Attributo: Option.ACTIONS

     All actions must be listed in ACTIONS.

 -- Attributo: Option.STORE_ACTIONS

     «store» actions are additionally listed here.

 -- Attributo: Option.TYPED_ACTIONS

     «typed» actions are additionally listed here.

 -- Attributo: Option.ALWAYS_TYPED_ACTIONS

     Actions that always take a type (i.e.  whose options always take a
     value) are additionally listed here.  The only effect of this is
     that *note optparse: a4. assigns the default type, ‘"string"’, to
     options with no explicit type whose action is listed in *note
     ALWAYS_TYPED_ACTIONS: 3430.

In order to actually implement your new action, you must override
Option’s ‘take_action()’ method and add a case that recognizes your
action.

For example, let’s add an ‘"extend"’ action.  This is similar to the
standard ‘"append"’ action, but instead of taking a single value from
the command-line and appending it to an existing list, ‘"extend"’ will
take multiple values in a single comma-delimited string, and extend an
existing list with them.  That is, if ‘--names’ is an ‘"extend"’ option
of type ‘"string"’, the command line

     --names=foo,bar --names blah --names ding,dong

would result in a list

     ["foo", "bar", "blah", "ding", "dong"]

Again we define a subclass of Option:

     class MyOption(Option):

         ACTIONS = Option.ACTIONS + ("extend",)
         STORE_ACTIONS = Option.STORE_ACTIONS + ("extend",)
         TYPED_ACTIONS = Option.TYPED_ACTIONS + ("extend",)
         ALWAYS_TYPED_ACTIONS = Option.ALWAYS_TYPED_ACTIONS + ("extend",)

         def take_action(self, action, dest, opt, value, values, parser):
             if action == "extend":
                 lvalue = value.split(",")
                 values.ensure_value(dest, []).extend(lvalue)
             else:
                 Option.take_action(
                     self, action, dest, opt, value, values, parser)

Features of note:

   * ‘"extend"’ both expects a value on the command-line and stores that
     value somewhere, so it goes in both *note STORE_ACTIONS: 342e. and
     *note TYPED_ACTIONS: 342f.

   * to ensure that *note optparse: a4. assigns the default type of
     ‘"string"’ to ‘"extend"’ actions, we put the ‘"extend"’ action in
     *note ALWAYS_TYPED_ACTIONS: 3430. as well.

   * ‘MyOption.take_action()’ implements just this one new action, and
     passes control back to ‘Option.take_action()’ for the standard
     *note optparse: a4. actions.

   * ‘values’ is an instance of the optparse_parser.Values class, which
     provides the very useful ‘ensure_value()’ method.  ‘ensure_value()’
     is essentially *note getattr(): dcc. with a safety valve; it is
     called as

          values.ensure_value(attr, value)

     If the ‘attr’ attribute of ‘values’ doesn’t exist or is ‘None’,
     then ensure_value() first sets it to ‘value’, and then returns
     ‘value’.  This is very handy for actions like ‘"extend"’,
     ‘"append"’, and ‘"count"’, all of which accumulate data in a
     variable and expect that variable to be of a certain type (a list
     for the first two, an integer for the latter).  Using
     ‘ensure_value()’ means that scripts using your action don’t have to
     worry about setting a default value for the option destinations in
     question; they can just leave the default as ‘None’ and
     ‘ensure_value()’ will take care of getting it right when it’s
     needed.


File: python.info,  Node: Exceptions<11>,  Prev: Extending optparse,  Up: optparse — Parser for command line options

5.17.2.43 Exceptions
....................

 -- Eccezione: optparse.OptionError

     Raised if an *note Option: 33f4. instance is created with invalid
     or inconsistent arguments.

 -- Eccezione: optparse.OptionConflictError

     Raised if conflicting options are added to an *note OptionParser:
     16d4.

 -- Eccezione: optparse.OptionValueError

     Raised if an invalid option value is encountered on the command
     line.

 -- Eccezione: optparse.BadOptionError

     Raised if an invalid option is passed on the command line.

 -- Eccezione: optparse.AmbiguousOptionError

     Raised if an ambiguous option is passed on the command line.


File: python.info,  Node: getpass — Portable password input,  Next: fileinput — Iterate over lines from multiple input streams,  Prev: optparse — Parser for command line options,  Up: Command-line interface libraries

5.17.3 ‘getpass’ — Portable password input
------------------------------------------

'Source code:' Lib/getpass.py(1)

__________________________________________________________________

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

The *note getpass: 66. module provides two functions:

 -- Funzione: getpass.getpass (prompt='Password: ', stream=None, *,
          echo_char=None)

     Prompt the user for a password without echoing.  The user is
     prompted using the string 'prompt', which defaults to ‘'Password:
     '’.  On Unix, the prompt is written to the file-like object
     'stream' using the replace error handler if needed.  'stream'
     defaults to the controlling terminal (‘/dev/tty’) or if that is
     unavailable to ‘sys.stderr’ (this argument is ignored on Windows).

     The 'echo_char' argument controls how user input is displayed while
     typing.  If 'echo_char' is ‘None’ (default), input remains hidden.
     Otherwise, 'echo_char' must be a single printable ASCII character
     and each typed character is replaced by it.  For example,
     ‘echo_char='*'’ will display asterisks instead of the actual input.

     If echo free input is unavailable getpass() falls back to printing
     a warning message to 'stream' and reading from ‘sys.stdin’ and
     issuing a *note GetPassWarning: 3437.

          Nota: If you call getpass from within IDLE, the input may be
          done in the terminal you launched IDLE from rather than the
          idle window itself.

          Nota: On Unix systems, when 'echo_char' is set, the terminal
          will be configured to operate in ‘noncanonical mode(2)’.  In
          particular, this means that line editing shortcuts such as
          ‘Ctrl’+‘U’ will not work and may insert unexpected characters
          into the input.

     Cambiato nella versione 3.14: Added the 'echo_char' parameter for
     keyboard feedback.

 -- Eccezione: getpass.GetPassWarning

     A *note UserWarning: 26f6. subclass issued when password input may
     be echoed.

 -- Funzione: getpass.getuser ()

     Return the «login name» of the user.

     This function checks the environment variables ‘LOGNAME’, ‘USER’,
     ‘LNAME’ and ‘USERNAME’, in order, and returns the value of the
     first one which is set to a non-empty string.  If none are set, the
     login name from the password database is returned on systems which
     support the *note pwd: b7. module, otherwise, an *note OSError:
     2c0. is raised.

     In general, this function should be preferred over *note
     os.getlogin(): 180a.

     Cambiato nella versione 3.13: Previously, various exceptions beyond
     just *note OSError: 2c0. were raised.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/getpass.py

   (2) 
https://manpages.debian.org/termios(3)#Canonical_and_noncanonical_mode


File: python.info,  Node: fileinput — Iterate over lines from multiple input streams,  Next: curses — Terminal handling for character-cell displays,  Prev: getpass — Portable password input,  Up: Command-line interface libraries

5.17.4 ‘fileinput’ — Iterate over lines from multiple input streams
-------------------------------------------------------------------

'Source code:' Lib/fileinput.py(1)

__________________________________________________________________

This module implements a helper class and functions to quickly write a
loop over standard input or a list of files.  If you just want to read
or write one file see *note open(): 316.

The typical use is:

     import fileinput
     for line in fileinput.input(encoding="utf-8"):
         process(line)

This iterates over the lines of all files listed in ‘sys.argv[1:]’,
defaulting to ‘sys.stdin’ if the list is empty.  If a filename is ‘'-'’,
it is also replaced by ‘sys.stdin’ and the optional arguments 'mode' and
'openhook' are ignored.  To specify an alternative list of filenames,
pass it as the first argument to *note input(): a02.  A single file name
is also allowed.

All files are opened in text mode by default, but you can override this
by specifying the 'mode' parameter in the call to *note input(): a02. or
*note FileInput: 941.  If an I/O error occurs during opening or reading
a file, *note OSError: 2c0. is raised.

Cambiato nella versione 3.3: *note IOError: 1255. used to be raised; it
is now an alias of *note OSError: 2c0.

If ‘sys.stdin’ is used more than once, the second and further use will
return no lines, except perhaps for interactive use, or if it has been
explicitly reset (e.g.  using ‘sys.stdin.seek(0)’).

Empty files are opened and immediately closed; the only time their
presence in the list of filenames is noticeable at all is when the last
file opened is empty.

Lines are returned with any newlines intact, which means that the last
line in a file may not have one.

You can control how files are opened by providing an opening hook via
the 'openhook' parameter to *note fileinput.input(): a02. or *note
FileInput(): 941.  The hook must be a function that takes two arguments,
'filename' and 'mode', and returns an accordingly opened file-like
object.  If 'encoding' and/or 'errors' are specified, they will be
passed to the hook as additional keyword arguments.  This module
provides a *note hook_compressed(): a03. to support compressed files.

The following function is the primary interface of this module:

 -- Funzione: fileinput.input (files=None, inplace=False, backup='', *,
          mode='r', openhook=None, encoding=None, errors=None)

     Create an instance of the *note FileInput: 941. class.  The
     instance will be used as global state for the functions of this
     module, and is also returned to use during iteration.  The
     parameters to this function will be passed along to the constructor
     of the *note FileInput: 941. class.

     The *note FileInput: 941. instance can be used as a context manager
     in the *note with: 186. statement.  In this example, 'input' is
     closed after the ‘with’ statement is exited, even if an exception
     occurs:

          with fileinput.input(files=('spam.txt', 'eggs.txt'), encoding="utf-8") as f:
              for line in f:
                  process(line)

     Cambiato nella versione 3.2: Can be used as a context manager.

     Cambiato nella versione 3.8: The keyword parameters 'mode' and
     'openhook' are now keyword-only.

     Cambiato nella versione 3.10: The keyword-only parameter 'encoding'
     and 'errors' are added.

The following functions use the global state created by *note
fileinput.input(): a02.; if there is no active state, *note
RuntimeError: 244. is raised.

 -- Funzione: fileinput.filename ()

     Return the name of the file currently being read.  Before the first
     line has been read, returns ‘None’.

 -- Funzione: fileinput.fileno ()

     Return the integer «file descriptor» for the current file.  When no
     file is opened (before the first line and between files), returns
     ‘-1’.

 -- Funzione: fileinput.lineno ()

     Return the cumulative line number of the line that has just been
     read.  Before the first line has been read, returns ‘0’.  After the
     last line of the last file has been read, returns the line number
     of that line.

 -- Funzione: fileinput.filelineno ()

     Return the line number in the current file.  Before the first line
     has been read, returns ‘0’.  After the last line of the last file
     has been read, returns the line number of that line within the
     file.

 -- Funzione: fileinput.isfirstline ()

     Return ‘True’ if the line just read is the first line of its file,
     otherwise return ‘False’.

 -- Funzione: fileinput.isstdin ()

     Return ‘True’ if the last line was read from ‘sys.stdin’, otherwise
     return ‘False’.

 -- Funzione: fileinput.nextfile ()

     Close the current file so that the next iteration will read the
     first line from the next file (if any); lines not read from the
     file will not count towards the cumulative line count.  The
     filename is not changed until after the first line of the next file
     has been read.  Before the first line has been read, this function
     has no effect; it cannot be used to skip the first file.  After the
     last line of the last file has been read, this function has no
     effect.

 -- Funzione: fileinput.close ()

     Close the sequence.

The class which implements the sequence behavior provided by the module
is available for subclassing as well:

 -- Classe: fileinput.FileInput (files=None, inplace=False, backup='',
          *, mode='r', openhook=None, encoding=None, errors=None)

     Class *note FileInput: 941. is the implementation; its methods
     *note filename(): 343b, *note fileno(): 1635, *note lineno(): 343c,
     *note filelineno(): 343d, *note isfirstline(): 343e, *note
     isstdin(): 343f, *note nextfile(): 3440. and *note close(): 3441.
     correspond to the functions of the same name in the module.  In
     addition it is *note iterable: 142f. and has a *note readline():
     2090. method which returns the next input line.  The sequence must
     be accessed in strictly sequential order; random access and *note
     readline(): 2090. cannot be mixed.

     With 'mode' you can specify which file mode will be passed to *note
     open(): 316.  It must be one of ‘'r'’ and ‘'rb'’.

     The 'openhook', when given, must be a function that takes two
     arguments, 'filename' and 'mode', and returns an accordingly opened
     file-like object.  You cannot use 'inplace' and 'openhook'
     together.

     You can specify 'encoding' and 'errors' that is passed to *note
     open(): 316. or 'openhook'.

     A *note FileInput: 941. instance can be used as a context manager
     in the *note with: 186. statement.  In this example, 'input' is
     closed after the ‘with’ statement is exited, even if an exception
     occurs:

          with FileInput(files=('spam.txt', 'eggs.txt')) as input:
              process(input)

     Cambiato nella versione 3.2: Can be used as a context manager.

     Cambiato nella versione 3.8: The keyword parameter 'mode' and
     'openhook' are now keyword-only.

     Cambiato nella versione 3.10: The keyword-only parameter 'encoding'
     and 'errors' are added.

     Cambiato nella versione 3.11: The ‘'rU'’ and ‘'U'’ modes and the
     ‘__getitem__()’ method have been removed.

'Optional in-place filtering:' if the keyword argument ‘inplace=True’ is
passed to *note fileinput.input(): a02. or to the *note FileInput: 941.
constructor, the file is moved to a backup file and standard output is
directed to the input file (if a file of the same name as the backup
file already exists, it will be replaced silently).  This makes it
possible to write a filter that rewrites its input file in place.  If
the 'backup' parameter is given (typically as ‘backup='.<some
extension>'’), it specifies the extension for the backup file, and the
backup file remains around; by default, the extension is ‘'.bak'’ and it
is deleted when the output file is closed.  In-place filtering is
disabled when standard input is read.

The two following opening hooks are provided by this module:

 -- Funzione: fileinput.hook_compressed (filename, mode, *,
          encoding=None, errors=None)

     Transparently opens files compressed with gzip and bzip2
     (recognized by the extensions ‘'.gz'’ and ‘'.bz2'’) using the *note
     gzip: 6b. and *note bz2: 14. modules.  If the filename extension is
     not ‘'.gz'’ or ‘'.bz2'’, the file is opened normally (ie, using
     *note open(): 316. without any decompression).

     The 'encoding' and 'errors' values are passed to *note
     io.TextIOWrapper: 9c0. for compressed files and open for normal
     files.

     Usage example: ‘fi =
     fileinput.FileInput(openhook=fileinput.hook_compressed,
     encoding="utf-8")’

     Cambiato nella versione 3.10: The keyword-only parameter 'encoding'
     and 'errors' are added.

 -- Funzione: fileinput.hook_encoded (encoding, errors=None)

     Returns a hook which opens each file with *note open(): 316, using
     the given 'encoding' and 'errors' to read the file.

     Usage example: ‘fi =
     fileinput.FileInput(openhook=fileinput.hook_encoded("utf-8",
     "surrogateescape"))’

     Cambiato nella versione 3.6: Added the optional 'errors' parameter.

     Deprecato dalla versione 3.10: This function is deprecated since
     *note fileinput.input(): a02. and *note FileInput: 941. now have
     'encoding' and 'errors' parameters.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/fileinput.py


File: python.info,  Node: curses — Terminal handling for character-cell displays,  Next: curses textpad — Text input widget for curses programs,  Prev: fileinput — Iterate over lines from multiple input streams,  Up: Command-line interface libraries

5.17.5 ‘curses’ — Terminal handling for character-cell displays
---------------------------------------------------------------

'Source code:' Lib/curses(1)

__________________________________________________________________

The *note curses: 2f. module provides an interface to the curses
library, the de-facto standard for portable advanced terminal handling.

While curses is most widely used in the Unix environment, versions are
available for Windows, DOS, and possibly other systems as well.  This
extension module is designed to match the API of ncurses, an open-source
curses library hosted on Linux and the BSD variants of Unix.

*note Availability: 2128.: not Android, not iOS, not WASI.

This module is not supported on *note mobile platforms: 2245. or *note
WebAssembly platforms: 1b52.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

     Nota: Whenever the documentation mentions a 'character' it can be
     specified as an integer, a one-character Unicode string or a
     one-byte byte string.

     Whenever the documentation mentions a 'character string' it can be
     specified as a Unicode string or a byte string.

Vedi anche
..........

Module *note curses.ascii: 30.

     Utilities for working with ASCII characters, regardless of your
     locale settings.

Module *note curses.panel: 31.

     A panel stack extension that adds depth to curses windows.

Module *note curses.textpad: 32.

     Editable text widget for curses supporting ‘Emacs’-like bindings.

*note Curses Programming with Python: 3445.

     Tutorial material on using curses with Python, by Andrew Kuchling
     and Eric Raymond.

* Menu:

* Functions: Functions<5>.
* Window Objects::
* Constants: Constants<6>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/curses


File: python.info,  Node: Functions<5>,  Next: Window Objects,  Up: curses — Terminal handling for character-cell displays

5.17.5.1 Functions
..................

The module *note curses: 2f. defines the following exception:

 -- Eccezione: curses.error

     Exception raised when a curses library function returns an error.

     Nota: Whenever 'x' or 'y' arguments to a function or a method are
     optional, they default to the current cursor location.  Whenever
     'attr' is optional, it defaults to *note A_NORMAL: 3449.

The module *note curses: 2f. defines the following functions:

 -- Funzione: curses.assume_default_colors (fg, bg, /)

     Allow use of default values for colors on terminals supporting this
     feature.  Use this to support transparency in your application.

        * Assign terminal default foreground/background colors to color
          number ‘-1’.  So ‘init_pair(x, COLOR_RED, -1)’ will initialize
          pair 'x' as red on default background and ‘init_pair(x, -1,
          COLOR_BLUE)’ will initialize pair 'x' as default foreground on
          blue.

        * Change the definition of the color-pair ‘0’ to ‘(fg, bg)’.

     Added in version 3.14.

 -- Funzione: curses.baudrate ()

     Return the output speed of the terminal in bits per second.  On
     software terminal emulators it will have a fixed high value.
     Included for historical reasons; in former times, it was used to
     write output loops for time delays and occasionally to change
     interfaces depending on the line speed.

 -- Funzione: curses.beep ()

     Emit a short attention sound.

 -- Funzione: curses.can_change_color ()

     Return ‘True’ or ‘False’, depending on whether the programmer can
     change the colors displayed by the terminal.

 -- Funzione: curses.cbreak ()

     Enter cbreak mode.  In cbreak mode (sometimes called «rare» mode)
     normal tty line buffering is turned off and characters are
     available to be read one by one.  However, unlike raw mode, special
     characters (interrupt, quit, suspend, and flow control) retain
     their effects on the tty driver and calling program.  Calling first
     *note raw(): 344e. then *note cbreak(): 344d. leaves the terminal
     in cbreak mode.

 -- Funzione: curses.color_content (color_number)

     Return the intensity of the red, green, and blue (RGB) components
     in the color 'color_number', which must be between ‘0’ and ‘COLORS
     - 1’.  Return a 3-tuple, containing the R,G,B values for the given
     color, which will be between ‘0’ (no component) and ‘1000’ (maximum
     amount of component).

 -- Funzione: curses.color_pair (pair_number)

     Return the attribute value for displaying text in the specified
     color pair.  Only the first 256 color pairs are supported.  This
     attribute value can be combined with *note A_STANDOUT: 3450, *note
     A_REVERSE: 3451, and the other ‘A_*’ attributes.  *note
     pair_number(): 3452. is the counterpart to this function.

 -- Funzione: curses.curs_set (visibility)

     Set the cursor state.  'visibility' can be set to ‘0’, ‘1’, or ‘2’,
     for invisible, normal, or very visible.  If the terminal supports
     the visibility requested, return the previous cursor state;
     otherwise raise an exception.  On many terminals, the «visible»
     mode is an underline cursor and the «very visible» mode is a block
     cursor.

 -- Funzione: curses.def_prog_mode ()

     Save the current terminal mode as the «program» mode, the mode when
     the running program is using curses.  (Its counterpart is the
     «shell» mode, for when the program is not in curses.)  Subsequent
     calls to *note reset_prog_mode(): 3455. will restore this mode.

 -- Funzione: curses.def_shell_mode ()

     Save the current terminal mode as the «shell» mode, the mode when
     the running program is not using curses.  (Its counterpart is the
     «program» mode, when the program is using curses capabilities.)
     Subsequent calls to *note reset_shell_mode(): 3457. will restore
     this mode.

 -- Funzione: curses.delay_output (ms)

     Insert an 'ms' millisecond pause in output.

 -- Funzione: curses.doupdate ()

     Update the physical screen.  The curses library keeps two data
     structures, one representing the current physical screen contents
     and a virtual screen representing the desired next state.  The
     *note doupdate(): 3459. ground updates the physical screen to match
     the virtual screen.

     The virtual screen may be updated by a *note noutrefresh(): 345a.
     call after write operations such as *note addstr(): 345b. have been
     performed on a window.  The normal *note refresh(): 345c. call is
     simply ‘noutrefresh()’ followed by ‘doupdate()’; if you have to
     update multiple windows, you can speed performance and perhaps
     reduce screen flicker by issuing ‘noutrefresh()’ calls on all
     windows, followed by a single ‘doupdate()’.

 -- Funzione: curses.echo ()

     Enter echo mode.  In echo mode, each character input is echoed to
     the screen as it is entered.

 -- Funzione: curses.endwin ()

     De-initialize the library, and return terminal to normal status.

 -- Funzione: curses.erasechar ()

     Return the user’s current erase character as a one-byte bytes
     object.  Under Unix operating systems this is a property of the
     controlling tty of the curses program, and is not set by the curses
     library itself.

 -- Funzione: curses.filter ()

     The *note filter(): 3460. routine, if used, must be called before
     *note initscr(): 18f7. is called.  The effect is that, during those
     calls, ‘LINES’ is set to ‘1’; the capabilities ‘clear’, ‘cup’,
     ‘cud’, ‘cud1’, ‘cuu1’, ‘cuu’, ‘vpa’ are disabled; and the ‘home’
     string is set to the value of ‘cr’.  The effect is that the cursor
     is confined to the current line, and so are screen updates.  This
     may be used for enabling character-at-a-time line editing without
     touching the rest of the screen.

 -- Funzione: curses.flash ()

     Flash the screen.  That is, change it to reverse-video and then
     change it back in a short interval.  Some people prefer such as
     “visible bell” to the audible attention signal produced by *note
     beep(): 344b.

 -- Funzione: curses.flushinp ()

     Flush all input buffers.  This throws away any typeahead that has
     been typed by the user and has not yet been processed by the
     program.

 -- Funzione: curses.getmouse ()

     After *note getch(): 180d. returns *note KEY_MOUSE: 3464. to signal
     a mouse event, this method should be called to retrieve the queued
     mouse event, represented as a 5-tuple ‘(id, x, y, z, bstate)’.
     'id' is an ID value used to distinguish multiple devices, and 'x',
     'y', 'z' are the event’s coordinates.  ('z' is currently unused.)
     'bstate' is an integer value whose bits will be set to indicate the
     type of event, and will be the bitwise OR of one or more of the
     following constants, where 'n' is the button number from 1 to 5:
     *note BUTTONn_PRESSED: 3465, *note BUTTONn_RELEASED: 3466, *note
     BUTTONn_CLICKED: 3467, *note BUTTONn_DOUBLE_CLICKED: 3468, *note
     BUTTONn_TRIPLE_CLICKED: 3469, *note BUTTON_SHIFT: 346a, *note
     BUTTON_CTRL: 346b, *note BUTTON_ALT: 346c.

     Cambiato nella versione 3.10: The ‘BUTTON5_*’ constants are now
     exposed if they are provided by the underlying curses library.

 -- Funzione: curses.getsyx ()

     Return the current coordinates of the virtual screen cursor as a
     tuple ‘(y, x)’.  If *note leaveok: 346e. is currently ‘True’, then
     return ‘(-1, -1)’.

 -- Funzione: curses.getwin (file)

     Read window related data stored in the file by an earlier *note
     window.putwin(): 3470. call.  The routine then creates and
     initializes a new window using that data, returning the new window
     object.

 -- Funzione: curses.has_colors ()

     Return ‘True’ if the terminal can display colors; otherwise, return
     ‘False’.

 -- Funzione: curses.has_extended_color_support ()

     Return ‘True’ if the module supports extended colors; otherwise,
     return ‘False’.  Extended color support allows more than 256 color
     pairs for terminals that support more than 16 colors (e.g.
     xterm-256color).

     Extended color support requires ncurses version 6.1 or later.

     Added in version 3.10.

 -- Funzione: curses.has_ic ()

     Return ‘True’ if the terminal has insert- and delete-character
     capabilities.  This function is included for historical reasons
     only, as all modern software terminal emulators have such
     capabilities.

 -- Funzione: curses.has_il ()

     Return ‘True’ if the terminal has insert- and delete-line
     capabilities, or can simulate them using scrolling regions.  This
     function is included for historical reasons only, as all modern
     software terminal emulators have such capabilities.

 -- Funzione: curses.has_key (ch)

     Take a key value 'ch', and return ‘True’ if the current terminal
     type recognizes a key with that value.

 -- Funzione: curses.halfdelay (tenths)

     Used for half-delay mode, which is similar to cbreak mode in that
     characters typed by the user are immediately available to the
     program.  However, after blocking for 'tenths' tenths of seconds,
     raise an exception if nothing has been typed.  The value of
     'tenths' must be a number between ‘1’ and ‘255’.  Use *note
     nocbreak(): 3476. to leave half-delay mode.

 -- Funzione: curses.init_color (color_number, r, g, b)

     Change the definition of a color, taking the number of the color to
     be changed followed by three RGB values (for the amounts of red,
     green, and blue components).  The value of 'color_number' must be
     between ‘0’ and ‘COLORS - 1’.  Each of 'r', 'g', 'b', must be a
     value between ‘0’ and ‘1000’.  When *note init_color(): 9f5. is
     used, all occurrences of that color on the screen immediately
     change to the new definition.  This function is a no-op on most
     terminals; it is active only if *note can_change_color(): 344c.
     returns ‘True’.

 -- Funzione: curses.init_pair (pair_number, fg, bg)

     Change the definition of a color-pair.  It takes three arguments:
     the number of the color-pair to be changed, the foreground color
     number, and the background color number.  The value of
     'pair_number' must be between ‘1’ and ‘COLOR_PAIRS - 1’ (the ‘0’
     color pair can only be changed by *note use_default_colors(): 1f7.
     and *note assume_default_colors(): 1f6.).  The value of 'fg' and
     'bg' arguments must be between ‘0’ and ‘COLORS - 1’, or, after
     calling ‘use_default_colors()’ or ‘assume_default_colors()’, ‘-1’.
     If the color-pair was previously initialized, the screen is
     refreshed and all occurrences of that color-pair are changed to the
     new definition.

 -- Funzione: curses.initscr ()

     Initialize the library.  Return a *note window: 1971. object which
     represents the whole screen.

          Nota: If there is an error opening the terminal, the
          underlying curses library may cause the interpreter to exit.

 -- Funzione: curses.is_term_resized (nlines, ncols)

     Return ‘True’ if *note resize_term(): 1918. would modify the window
     structure, ‘False’ otherwise.

 -- Funzione: curses.isendwin ()

     Return ‘True’ if *note endwin(): 345e. has been called (that is,
     the curses library has been deinitialized).

 -- Funzione: curses.keyname (k)

     Return the name of the key numbered 'k' as a bytes object.  The
     name of a key generating printable ASCII character is the key’s
     character.  The name of a control-key combination is a two-byte
     bytes object consisting of a caret (‘b'^'’) followed by the
     corresponding printable ASCII character.  The name of an alt-key
     combination (128–255) is a bytes object consisting of the prefix
     ‘b'M-'’ followed by the name of the corresponding ASCII character.

 -- Funzione: curses.killchar ()

     Return the user’s current line kill character as a one-byte bytes
     object.  Under Unix operating systems this is a property of the
     controlling tty of the curses program, and is not set by the curses
     library itself.

 -- Funzione: curses.longname ()

     Return a bytes object containing the terminfo long name field
     describing the current terminal.  The maximum length of a verbose
     description is 128 characters.  It is defined only after the call
     to *note initscr(): 18f7.

 -- Funzione: curses.meta (flag)

     If 'flag' is ‘True’, allow 8-bit characters to be input.  If 'flag'
     is ‘False’, allow only 7-bit chars.

 -- Funzione: curses.mouseinterval (interval)

     Set the maximum time in milliseconds that can elapse between press
     and release events in order for them to be recognized as a click,
     and return the previous interval value.  The default value is 200
     milliseconds, or one fifth of a second.

 -- Funzione: curses.mousemask (mousemask)

     Set the mouse events to be reported, and return a tuple
     ‘(availmask, oldmask)’.  'availmask' indicates which of the
     specified mouse events can be reported; on complete failure it
     returns ‘0’.  'oldmask' is the previous value of the given window’s
     mouse event mask.  If this function is never called, no mouse
     events are ever reported.

 -- Funzione: curses.napms (ms)

     Sleep for 'ms' milliseconds.

 -- Funzione: curses.newpad (nlines, ncols)

     Create and return a pointer to a new pad data structure with the
     given number of lines and columns.  Return a pad as a window
     object.

     A pad is like a window, except that it is not restricted by the
     screen size, and is not necessarily associated with a particular
     part of the screen.  Pads can be used when a large window is
     needed, and only a part of the window will be on the screen at one
     time.  Automatic refreshes of pads (such as from scrolling or
     echoing of input) do not occur.  The *note refresh(): 345c. and
     *note noutrefresh(): 345a. methods of a pad require 6 arguments to
     specify the part of the pad to be displayed and the location on the
     screen to be used for the display.  The arguments are 'pminrow',
     'pmincol', 'sminrow', 'smincol', 'smaxrow', 'smaxcol'; the 'p'
     arguments refer to the upper left corner of the pad region to be
     displayed and the 's' arguments define a clipping box on the screen
     within which the pad region is to be displayed.

 -- Funzione: curses.newwin (nlines, ncols)

 -- Funzione: curses.newwin (nlines, ncols, begin_y, begin_x)

     Return a new *note window: 1971, whose left-upper corner is at
     ‘(begin_y, begin_x)’, and whose height/width is 'nlines'/'ncols'.

     By default, the window will extend from the specified position to
     the lower right corner of the screen.

 -- Funzione: curses.nl ()

     Enter newline mode.  This mode translates the return key into
     newline on input, and translates newline into return and line-feed
     on output.  Newline mode is initially on.

 -- Funzione: curses.nocbreak ()

     Leave cbreak mode.  Return to normal «cooked» mode with line
     buffering.

 -- Funzione: curses.noecho ()

     Leave echo mode.  Echoing of input characters is turned off.

 -- Funzione: curses.nonl ()

     Leave newline mode.  Disable translation of return into newline on
     input, and disable low-level translation of newline into
     newline/return on output (but this does not change the behavior of
     ‘addch('\n')’, which always does the equivalent of return and line
     feed on the virtual screen).  With translation off, curses can
     sometimes speed up vertical motion a little; also, it will be able
     to detect the return key on input.

 -- Funzione: curses.noqiflush ()

     When the ‘noqiflush()’ routine is used, normal flush of input and
     output queues associated with the ‘INTR’, ‘QUIT’ and ‘SUSP’
     characters will not be done.  You may want to call ‘noqiflush()’ in
     a signal handler if you want output to continue as though the
     interrupt had not occurred, after the handler exits.

 -- Funzione: curses.noraw ()

     Leave raw mode.  Return to normal «cooked» mode with line
     buffering.

 -- Funzione: curses.pair_content (pair_number)

     Return a tuple ‘(fg, bg)’ containing the colors for the requested
     color pair.  The value of 'pair_number' must be between ‘0’ and
     ‘COLOR_PAIRS - 1’.

 -- Funzione: curses.pair_number (attr)

     Return the number of the color-pair set by the attribute value
     'attr'.  *note color_pair(): 344f. is the counterpart to this
     function.

 -- Funzione: curses.putp (str)

     Equivalent to ‘tputs(str, 1, putchar)’; emit the value of a
     specified terminfo capability for the current terminal.  Note that
     the output of *note putp(): 3486. always goes to standard output.

 -- Funzione: curses.qiflush ([flag])

     If 'flag' is ‘False’, the effect is the same as calling *note
     noqiflush(): 3484.  If 'flag' is ‘True’, or no argument is
     provided, the queues will be flushed when these control characters
     are read.

 -- Funzione: curses.raw ()

     Enter raw mode.  In raw mode, normal line buffering and processing
     of interrupt, quit, suspend, and flow control keys are turned off;
     characters are presented to curses input functions one by one.

 -- Funzione: curses.reset_prog_mode ()

     Restore the terminal to «program» mode, as previously saved by
     *note def_prog_mode(): 3454.

 -- Funzione: curses.reset_shell_mode ()

     Restore the terminal to «shell» mode, as previously saved by *note
     def_shell_mode(): 3456.

 -- Funzione: curses.resetty ()

     Restore the state of the terminal modes to what it was at the last
     call to *note savetty(): 3489.

 -- Funzione: curses.resize_term (nlines, ncols)

     Backend function used by *note resizeterm(): 1917, performing most
     of the work; when resizing the windows, *note resize_term(): 1918.
     blank-fills the areas that are extended.  The calling application
     should fill in these areas with appropriate data.  The
     ‘resize_term()’ function attempts to resize all windows.  However,
     due to the calling convention of pads, it is not possible to resize
     these without additional interaction with the application.

 -- Funzione: curses.resizeterm (nlines, ncols)

     Resize the standard and current windows to the specified
     dimensions, and adjusts other bookkeeping data used by the curses
     library that record the window dimensions (in particular the
     SIGWINCH handler).

 -- Funzione: curses.savetty ()

     Save the current state of the terminal modes in a buffer, usable by
     *note resetty(): 3488.

 -- Funzione: curses.get_escdelay ()

     Retrieves the value set by *note set_escdelay(): aef.

     Added in version 3.9.

 -- Funzione: curses.set_escdelay (ms)

     Sets the number of milliseconds to wait after reading an escape
     character, to distinguish between an individual escape character
     entered on the keyboard from escape sequences sent by cursor and
     function keys.

     Added in version 3.9.

 -- Funzione: curses.get_tabsize ()

     Retrieves the value set by *note set_tabsize(): af1.

     Added in version 3.9.

 -- Funzione: curses.set_tabsize (size)

     Sets the number of columns used by the curses library when
     converting a tab character to spaces as it adds the tab to a
     window.

     Added in version 3.9.

 -- Funzione: curses.setsyx (y, x)

     Set the virtual screen cursor to 'y', 'x'.  If 'y' and 'x' are both
     ‘-1’, then *note leaveok: 346e. is set ‘True’.

 -- Funzione: curses.setupterm (term=None, fd=-1)

     Initialize the terminal.  'term' is a string giving the terminal
     name, or ‘None’; if omitted or ‘None’, the value of the ‘TERM’
     environment variable will be used.  'fd' is the file descriptor to
     which any initialization sequences will be sent; if not supplied or
     ‘-1’, the file descriptor for ‘sys.stdout’ will be used.

 -- Funzione: curses.start_color ()

     Must be called if the programmer wants to use colors, and before
     any other color manipulation routine is called.  It is good
     practice to call this routine right after *note initscr(): 18f7.

     *note start_color(): 348c. initializes eight basic colors (black,
     red, green, yellow, blue, magenta, cyan, and white), and two global
     variables in the *note curses: 2f. module, *note COLORS: 348d. and
     *note COLOR_PAIRS: 348e, containing the maximum number of colors
     and color-pairs the terminal can support.  It also restores the
     colors on the terminal to the values they had when the terminal was
     just turned on.

 -- Funzione: curses.termattrs ()

     Return a logical OR of all video attributes supported by the
     terminal.  This information is useful when a curses program needs
     complete control over the appearance of the screen.

 -- Funzione: curses.termname ()

     Return the value of the environment variable ‘TERM’, as a bytes
     object, truncated to 14 characters.

 -- Funzione: curses.tigetflag (capname)

     Return the value of the Boolean capability corresponding to the
     terminfo capability name 'capname' as an integer.  Return the value
     ‘-1’ if 'capname' is not a Boolean capability, or ‘0’ if it is
     canceled or absent from the terminal description.

 -- Funzione: curses.tigetnum (capname)

     Return the value of the numeric capability corresponding to the
     terminfo capability name 'capname' as an integer.  Return the value
     ‘-2’ if 'capname' is not a numeric capability, or ‘-1’ if it is
     canceled or absent from the terminal description.

 -- Funzione: curses.tigetstr (capname)

     Return the value of the string capability corresponding to the
     terminfo capability name 'capname' as a bytes object.  Return
     ‘None’ if 'capname' is not a terminfo «string capability», or is
     canceled or absent from the terminal description.

 -- Funzione: curses.tparm (str[, ...])

     Instantiate the bytes object 'str' with the supplied parameters,
     where 'str' should be a parameterized string obtained from the
     terminfo database.  E.g.  ‘tparm(tigetstr("cup"), 5, 3)’ could
     result in ‘b'\033[6;4H'’, the exact result depending on terminal
     type.

 -- Funzione: curses.typeahead (fd)

     Specify that the file descriptor 'fd' be used for typeahead
     checking.  If 'fd' is ‘-1’, then no typeahead checking is done.

     The curses library does «line-breakout optimization» by looking for
     typeahead periodically while updating the screen.  If input is
     found, and it is coming from a tty, the current update is postponed
     until refresh or doupdate is called again, allowing faster response
     to commands typed in advance.  This function allows specifying a
     different file descriptor for typeahead checking.

 -- Funzione: curses.unctrl (ch)

     Return a bytes object which is a printable representation of the
     character 'ch'.  Control characters are represented as a caret
     followed by the character, for example as ‘b'^C'’.  Printing
     characters are left as they are.

 -- Funzione: curses.ungetch (ch)

     Push 'ch' so the next *note getch(): 180d. will return it.

          Nota: Only one 'ch' can be pushed before ‘getch()’ is called.

 -- Funzione: curses.update_lines_cols ()

     Update the *note LINES: fee. and *note COLS: fef. module variables.
     Useful for detecting manual screen resize.

     Added in version 3.5.

 -- Funzione: curses.unget_wch (ch)

     Push 'ch' so the next *note get_wch(): 129f. will return it.

          Nota: Only one 'ch' can be pushed before ‘get_wch()’ is
          called.

     Added in version 3.3.

 -- Funzione: curses.ungetmouse (id, x, y, z, bstate)

     Push a *note KEY_MOUSE: 3464. event onto the input queue,
     associating the given state data with it.

 -- Funzione: curses.use_env (flag)

     If used, this function should be called before *note initscr():
     18f7. or newterm are called.  When 'flag' is ‘False’, the values of
     lines and columns specified in the terminfo database will be used,
     even if environment variables ‘LINES’ and ‘COLUMNS’ (used by
     default) are set, or if curses is running in a window (in which
     case default behavior would be to use the window size if ‘LINES’
     and ‘COLUMNS’ are not set).

 -- Funzione: curses.use_default_colors ()

     Equivalent to ‘assume_default_colors(-1, -1)’.

 -- Funzione: curses.wrapper (func, /, *args, **kwargs)

     Initialize curses and call another callable object, 'func', which
     should be the rest of your curses-using application.  If the
     application raises an exception, this function will restore the
     terminal to a sane state before re-raising the exception and
     generating a traceback.  The callable object 'func' is then passed
     the main window “stdscr” as its first argument, followed by any
     other arguments passed to ‘wrapper()’.  Before calling 'func',
     ‘wrapper()’ turns on cbreak mode, turns off echo, enables the
     terminal keypad, and initializes colors if the terminal has color
     support.  On exit (whether normally or by exception) it restores
     cooked mode, turns on echo, and disables the terminal keypad.


File: python.info,  Node: Window Objects,  Next: Constants<6>,  Prev: Functions<5>,  Up: curses — Terminal handling for character-cell displays

5.17.5.2 Window Objects
.......................

 -- Classe: curses.window

     Window objects, as returned by *note initscr(): 18f7. and *note
     newwin(): 3480. above, have the following methods and attributes:

 -- Metodo: window.addch (ch[, attr])

 -- Metodo: window.addch (y, x, ch[, attr])

     Paint character 'ch' at ‘(y, x)’ with attributes 'attr',
     overwriting any character previously painted at that location.  By
     default, the character position and attributes are the current
     settings for the window object.

          Nota: Writing outside the window, subwindow, or pad raises a
          *note curses.error: 3448.  Attempting to write to the lower
          right corner of a window, subwindow, or pad will cause an
          exception to be raised after the character is printed.

 -- Metodo: window.addnstr (str, n[, attr])

 -- Metodo: window.addnstr (y, x, str, n[, attr])

     Paint at most 'n' characters of the character string 'str' at ‘(y,
     x)’ with attributes 'attr', overwriting anything previously on the
     display.

 -- Metodo: window.addstr (str[, attr])

 -- Metodo: window.addstr (y, x, str[, attr])

     Paint the character string 'str' at ‘(y, x)’ with attributes
     'attr', overwriting anything previously on the display.

          Nota: 
             * Writing outside the window, subwindow, or pad raises
               *note curses.error: 3448.  Attempting to write to the
               lower right corner of a window, subwindow, or pad will
               cause an exception to be raised after the string is
               printed.

             * A bug in ncurses(1), the backend for this Python module,
               can cause SegFaults when resizing windows.  This is fixed
               in ncurses-6.1-20190511.  If you are stuck with an
               earlier ncurses, you can avoid triggering this if you do
               not call *note addstr(): 345b. with a 'str' that has
               embedded newlines.  Instead, call *note addstr(): 345b.
               separately for each line.

 -- Metodo: window.attroff (attr)

     Remove attribute 'attr' from the «background» set applied to all
     writes to the current window.

 -- Metodo: window.attron (attr)

     Add attribute 'attr' to the «background» set applied to all writes
     to the current window.

 -- Metodo: window.attrset (attr)

     Set the «background» set of attributes to 'attr'.  This set is
     initially ‘0’ (no attributes).

 -- Metodo: window.bkgd (ch[, attr])

     Set the background property of the window to the character 'ch',
     with attributes 'attr'.  The change is then applied to every
     character position in that window:

        * The attribute of every character in the window is changed to
          the new background attribute.

        * Wherever the former background character appears, it is
          changed to the new background character.

 -- Metodo: window.bkgdset (ch[, attr])

     Set the window’s background.  A window’s background consists of a
     character and any combination of attributes.  The attribute part of
     the background is combined (OR’ed) with all non-blank characters
     that are written into the window.  Both the character and attribute
     parts of the background are combined with the blank characters.
     The background becomes a property of the character and moves with
     the character through any scrolling and insert/delete
     line/character operations.

 -- Metodo: window.border ([ls[, rs[, ts[, bs[, tl[, tr[, bl[,
          br]]]]]]]])

     Draw a border around the edges of the window.  Each parameter
     specifies the character to use for a specific part of the border;
     see the table below for more details.

          Nota: A ‘0’ value for any parameter will cause the default
          character to be used for that parameter.  Keyword parameters
          can 'not' be used.  The defaults are listed in this table:

     Parameter       Description               Default value
                                               
     ----------------------------------------------------------------------
                                               
     'ls'            Left side                 *note ACS_VLINE: 34a3.
                                               
                                               
     'rs'            Right side                *note ACS_VLINE: 34a3.
                                               
                                               
     'ts'            Top                       *note ACS_HLINE: 34a4.
                                               
                                               
     'bs'            Bottom                    *note ACS_HLINE: 34a4.
                                               
                                               
     'tl'            Upper-left corner         *note ACS_ULCORNER: 34a5.
                                               
                                               
     'tr'            Upper-right corner        *note ACS_URCORNER: 34a6.
                                               
                                               
     'bl'            Bottom-left corner        *note ACS_LLCORNER: 34a7.
                                               
                                               
     'br'            Bottom-right corner       *note ACS_LRCORNER: 34a8.
                                               

 -- Metodo: window.box ([vertch, horch])

     Similar to *note border(): 34a2, but both 'ls' and 'rs' are
     'vertch' and both 'ts' and 'bs' are 'horch'.  The default corner
     characters are always used by this function.

 -- Metodo: window.chgat (attr)

 -- Metodo: window.chgat (num, attr)

 -- Metodo: window.chgat (y, x, attr)

 -- Metodo: window.chgat (y, x, num, attr)

     Set the attributes of 'num' characters at the current cursor
     position, or at position ‘(y, x)’ if supplied.  If 'num' is not
     given or is ‘-1’, the attribute will be set on all the characters
     to the end of the line.  This function moves cursor to position
     ‘(y, x)’ if supplied.  The changed line will be touched using the
     *note touchline(): 34ab. method so that the contents will be
     redisplayed by the next window refresh.

 -- Metodo: window.clear ()

     Like *note erase(): 34ad, but also cause the whole window to be
     repainted upon next call to *note refresh(): 345c.

 -- Metodo: window.clearok (flag)

     If 'flag' is ‘True’, the next call to *note refresh(): 345c. will
     clear the window completely.

 -- Metodo: window.clrtobot ()

     Erase from cursor to the end of the window: all lines below the
     cursor are deleted, and then the equivalent of *note clrtoeol():
     34b0. is performed.

 -- Metodo: window.clrtoeol ()

     Erase from cursor to the end of the line.

 -- Metodo: window.cursyncup ()

     Update the current cursor position of all the ancestors of the
     window to reflect the current cursor position of the window.

 -- Metodo: window.delch ([y, x])

     Delete any character at ‘(y, x)’.

 -- Metodo: window.deleteln ()

     Delete the line under the cursor.  All following lines are moved up
     by one line.

 -- Metodo: window.derwin (begin_y, begin_x)

 -- Metodo: window.derwin (nlines, ncols, begin_y, begin_x)

     An abbreviation for «derive window», *note derwin(): 34b4. is the
     same as calling *note subwin(): 34b5, except that 'begin_y' and
     'begin_x' are relative to the origin of the window, rather than
     relative to the entire screen.  Return a window object for the
     derived window.

 -- Metodo: window.echochar (ch[, attr])

     Add character 'ch' with attribute 'attr', and immediately call
     *note refresh(): 345c. on the window.

 -- Metodo: window.enclose (y, x)

     Test whether the given pair of screen-relative character-cell
     coordinates are enclosed by the given window, returning ‘True’ or
     ‘False’.  It is useful for determining what subset of the screen
     windows enclose the location of a mouse event.

     Cambiato nella versione 3.10: Previously it returned ‘1’ or ‘0’
     instead of ‘True’ or ‘False’.

 -- Attributo: window.encoding

     Encoding used to encode method arguments (Unicode strings and
     characters).  The encoding attribute is inherited from the parent
     window when a subwindow is created, for example with *note
     window.subwin(): 34b5.  By default, current locale encoding is used
     (see *note locale.getencoding(): 329.).

     Added in version 3.3.

 -- Metodo: window.erase ()

     Clear the window.

 -- Metodo: window.getbegyx ()

     Return a tuple ‘(y, x)’ of coordinates of upper-left corner.

 -- Metodo: window.getbkgd ()

     Return the given window’s current background character/attribute
     pair.

 -- Metodo: window.getch ([y, x])

     Get a character.  Note that the integer returned does 'not' have to
     be in ASCII range: function keys, keypad keys and so on are
     represented by numbers higher than 255.  In no-delay mode, return
     ‘-1’ if there is no input, otherwise wait until a key is pressed.

 -- Metodo: window.get_wch ([y, x])

     Get a wide character.  Return a character for most keys, or an
     integer for function keys, keypad keys, and other special keys.  In
     no-delay mode, raise an exception if there is no input.

     Added in version 3.3.

 -- Metodo: window.getkey ([y, x])

     Get a character, returning a string instead of an integer, as *note
     getch(): 180d. does.  Function keys, keypad keys and other special
     keys return a multibyte string containing the key name.  In
     no-delay mode, raise an exception if there is no input.

 -- Metodo: window.getmaxyx ()

     Return a tuple ‘(y, x)’ of the height and width of the window.

 -- Metodo: window.getparyx ()

     Return the beginning coordinates of this window relative to its
     parent window as a tuple ‘(y, x)’.  Return ‘(-1, -1)’ if this
     window has no parent.

 -- Metodo: window.getstr ()

 -- Metodo: window.getstr (n)

 -- Metodo: window.getstr (y, x)

 -- Metodo: window.getstr (y, x, n)

     Read a bytes object from the user, with primitive line editing
     capacity.  The maximum value for 'n' is 2047.

     Cambiato nella versione 3.14: The maximum value for 'n' was
     increased from 1023 to 2047.

 -- Metodo: window.getyx ()

     Return a tuple ‘(y, x)’ of current cursor position relative to the
     window’s upper-left corner.

 -- Metodo: window.hline (ch, n)

 -- Metodo: window.hline (y, x, ch, n)

     Display a horizontal line starting at ‘(y, x)’ with length 'n'
     consisting of the character 'ch'.

 -- Metodo: window.idcok (flag)

     If 'flag' is ‘False’, curses no longer considers using the hardware
     insert/delete character feature of the terminal; if 'flag' is
     ‘True’, use of character insertion and deletion is enabled.  When
     curses is first initialized, use of character insert/delete is
     enabled by default.

 -- Metodo: window.idlok (flag)

     If 'flag' is ‘True’, *note curses: 2f. will try and use hardware
     line editing facilities.  Otherwise, line insertion/deletion are
     disabled.

 -- Metodo: window.immedok (flag)

     If 'flag' is ‘True’, any change in the window image automatically
     causes the window to be refreshed; you no longer have to call *note
     refresh(): 345c. yourself.  However, it may degrade performance
     considerably, due to repeated calls to wrefresh.  This option is
     disabled by default.

 -- Metodo: window.inch ([y, x])

     Return the character at the given position in the window.  The
     bottom 8 bits are the character proper, and upper bits are the
     attributes.

 -- Metodo: window.insch (ch[, attr])

 -- Metodo: window.insch (y, x, ch[, attr])

     Paint character 'ch' at ‘(y, x)’ with attributes 'attr', moving the
     line from position 'x' right by one character.

 -- Metodo: window.insdelln (nlines)

     Insert 'nlines' lines into the specified window above the current
     line.  The 'nlines' bottom lines are lost.  For negative 'nlines',
     delete 'nlines' lines starting with the one under the cursor, and
     move the remaining lines up.  The bottom 'nlines' lines are
     cleared.  The current cursor position remains the same.

 -- Metodo: window.insertln ()

     Insert a blank line under the cursor.  All following lines are
     moved down by one line.

 -- Metodo: window.insnstr (str, n[, attr])

 -- Metodo: window.insnstr (y, x, str, n[, attr])

     Insert a character string (as many characters as will fit on the
     line) before the character under the cursor, up to 'n' characters.
     If 'n' is zero or negative, the entire string is inserted.  All
     characters to the right of the cursor are shifted right, with the
     rightmost characters on the line being lost.  The cursor position
     does not change (after moving to 'y', 'x', if specified).

 -- Metodo: window.insstr (str[, attr])

 -- Metodo: window.insstr (y, x, str[, attr])

     Insert a character string (as many characters as will fit on the
     line) before the character under the cursor.  All characters to the
     right of the cursor are shifted right, with the rightmost
     characters on the line being lost.  The cursor position does not
     change (after moving to 'y', 'x', if specified).

 -- Metodo: window.instr ([n])

 -- Metodo: window.instr (y, x[, n])

     Return a bytes object of characters, extracted from the window
     starting at the current cursor position, or at 'y', 'x' if
     specified.  Attributes are stripped from the characters.  If 'n' is
     specified, *note instr(): 1825. returns a string at most 'n'
     characters long (exclusive of the trailing NUL). The maximum value
     for 'n' is 2047.

     Cambiato nella versione 3.14: The maximum value for 'n' was
     increased from 1023 to 2047.

 -- Metodo: window.is_linetouched (line)

     Return ‘True’ if the specified line was modified since the last
     call to *note refresh(): 345c.; otherwise return ‘False’.  Raise a
     *note curses.error: 3448. exception if 'line' is not valid for the
     given window.

 -- Metodo: window.is_wintouched ()

     Return ‘True’ if the specified window was modified since the last
     call to *note refresh(): 345c.; otherwise return ‘False’.

 -- Metodo: window.keypad (flag)

     If 'flag' is ‘True’, escape sequences generated by some keys
     (keypad, function keys) will be interpreted by *note curses: 2f.
     If 'flag' is ‘False’, escape sequences will be left as is in the
     input stream.

 -- Metodo: window.leaveok (flag)

     If 'flag' is ‘True’, cursor is left where it is on update, instead
     of being at «cursor position.» This reduces cursor movement where
     possible.  If possible the cursor will be made invisible.

     If 'flag' is ‘False’, cursor will always be at «cursor position»
     after an update.

 -- Metodo: window.move (new_y, new_x)

     Move cursor to ‘(new_y, new_x)’.

 -- Metodo: window.mvderwin (y, x)

     Move the window inside its parent window.  The screen-relative
     parameters of the window are not changed.  This routine is used to
     display different parts of the parent window at the same physical
     position on the screen.

 -- Metodo: window.mvwin (new_y, new_x)

     Move the window so its upper-left corner is at ‘(new_y, new_x)’.

 -- Metodo: window.nodelay (flag)

     If 'flag' is ‘True’, *note getch(): 180d. will be non-blocking.

 -- Metodo: window.notimeout (flag)

     If 'flag' is ‘True’, escape sequences will not be timed out.

     If 'flag' is ‘False’, after a few milliseconds, an escape sequence
     will not be interpreted, and will be left in the input stream as
     is.

 -- Metodo: window.noutrefresh ()

     Mark for refresh but wait.  This function updates the data
     structure representing the desired state of the window, but does
     not force an update of the physical screen.  To accomplish that,
     call *note doupdate(): 3459.

 -- Metodo: window.overlay (destwin[, sminrow, smincol, dminrow,
          dmincol, dmaxrow, dmaxcol])

     Overlay the window on top of 'destwin'.  The windows need not be
     the same size, only the overlapping region is copied.  This copy is
     non-destructive, which means that the current background character
     does not overwrite the old contents of 'destwin'.

     To get fine-grained control over the copied region, the second form
     of *note overlay(): 34cf. can be used.  'sminrow' and 'smincol' are
     the upper-left coordinates of the source window, and the other
     variables mark a rectangle in the destination window.

 -- Metodo: window.overwrite (destwin[, sminrow, smincol, dminrow,
          dmincol, dmaxrow, dmaxcol])

     Overwrite the window on top of 'destwin'.  The windows need not be
     the same size, in which case only the overlapping region is copied.
     This copy is destructive, which means that the current background
     character overwrites the old contents of 'destwin'.

     To get fine-grained control over the copied region, the second form
     of *note overwrite(): 34d0. can be used.  'sminrow' and 'smincol'
     are the upper-left coordinates of the source window, the other
     variables mark a rectangle in the destination window.

 -- Metodo: window.putwin (file)

     Write all data associated with the window into the provided file
     object.  This information can be later retrieved using the *note
     getwin(): 346f. function.

 -- Metodo: window.redrawln (beg, num)

     Indicate that the 'num' screen lines, starting at line 'beg', are
     corrupted and should be completely redrawn on the next *note
     refresh(): 345c. call.

 -- Metodo: window.redrawwin ()

     Touch the entire window, causing it to be completely redrawn on the
     next *note refresh(): 345c. call.

 -- Metodo: window.refresh ([pminrow, pmincol, sminrow, smincol,
          smaxrow, smaxcol])

     Update the display immediately (sync actual screen with previous
     drawing/deleting methods).

     The 6 optional arguments can only be specified when the window is a
     pad created with *note newpad(): 347f.  The additional parameters
     are needed to indicate what part of the pad and screen are
     involved.  'pminrow' and 'pmincol' specify the upper left-hand
     corner of the rectangle to be displayed in the pad.  'sminrow',
     'smincol', 'smaxrow', and 'smaxcol' specify the edges of the
     rectangle to be displayed on the screen.  The lower right-hand
     corner of the rectangle to be displayed in the pad is calculated
     from the screen coordinates, since the rectangles must be the same
     size.  Both rectangles must be entirely contained within their
     respective structures.  Negative values of 'pminrow', 'pmincol',
     'sminrow', or 'smincol' are treated as if they were zero.

 -- Metodo: window.resize (nlines, ncols)

     Reallocate storage for a curses window to adjust its dimensions to
     the specified values.  If either dimension is larger than the
     current values, the window’s data is filled with blanks that have
     the current background rendition (as set by *note bkgdset(): 34a1.)
     merged into them.

 -- Metodo: window.scroll ([lines=1])

     Scroll the screen or scrolling region upward by 'lines' lines.

 -- Metodo: window.scrollok (flag)

     Control what happens when the cursor of a window is moved off the
     edge of the window or scrolling region, either as a result of a
     newline action on the bottom line, or typing the last character of
     the last line.  If 'flag' is ‘False’, the cursor is left on the
     bottom line.  If 'flag' is ‘True’, the window is scrolled up one
     line.  Note that in order to get the physical scrolling effect on
     the terminal, it is also necessary to call *note idlok(): 34bf.

 -- Metodo: window.setscrreg (top, bottom)

     Set the scrolling region from line 'top' to line 'bottom'.  All
     scrolling actions will take place in this region.

 -- Metodo: window.standend ()

     Turn off the standout attribute.  On some terminals this has the
     side effect of turning off all attributes.

 -- Metodo: window.standout ()

     Turn on attribute 'A_STANDOUT'.

 -- Metodo: window.subpad (begin_y, begin_x)

 -- Metodo: window.subpad (nlines, ncols, begin_y, begin_x)

     Return a sub-window, whose upper-left corner is at ‘(begin_y,
     begin_x)’, and whose width/height is 'ncols'/'nlines'.

 -- Metodo: window.subwin (begin_y, begin_x)

 -- Metodo: window.subwin (nlines, ncols, begin_y, begin_x)

     Return a sub-window, whose upper-left corner is at ‘(begin_y,
     begin_x)’, and whose width/height is 'ncols'/'nlines'.

     By default, the sub-window will extend from the specified position
     to the lower right corner of the window.

 -- Metodo: window.syncdown ()

     Touch each location in the window that has been touched in any of
     its ancestor windows.  This routine is called by *note refresh():
     345c, so it should almost never be necessary to call it manually.

 -- Metodo: window.syncok (flag)

     If 'flag' is ‘True’, then *note syncup(): 34dc. is called
     automatically whenever there is a change in the window.

 -- Metodo: window.syncup ()

     Touch all locations in ancestors of the window that have been
     changed in the window.

 -- Metodo: window.timeout (delay)

     Set blocking or non-blocking read behavior for the window.  If
     'delay' is negative, blocking read is used (which will wait
     indefinitely for input).  If 'delay' is zero, then non-blocking
     read is used, and *note getch(): 180d. will return ‘-1’ if no input
     is waiting.  If 'delay' is positive, then *note getch(): 180d. will
     block for 'delay' milliseconds, and return ‘-1’ if there is still
     no input at the end of that time.

 -- Metodo: window.touchline (start, count[, changed])

     Pretend 'count' lines have been changed, starting with line
     'start'.  If 'changed' is supplied, it specifies whether the
     affected lines are marked as having been changed ('changed'‘=True’)
     or unchanged ('changed'‘=False’).

 -- Metodo: window.touchwin ()

     Pretend the whole window has been changed, for purposes of drawing
     optimizations.

 -- Metodo: window.untouchwin ()

     Mark all lines in the window as unchanged since the last call to
     *note refresh(): 345c.

 -- Metodo: window.vline (ch, n[, attr])

 -- Metodo: window.vline (y, x, ch, n[, attr])

     Display a vertical line starting at ‘(y, x)’ with length 'n'
     consisting of the character 'ch' with attributes 'attr'.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue35924


File: python.info,  Node: Constants<6>,  Prev: Window Objects,  Up: curses — Terminal handling for character-cell displays

5.17.5.3 Constants
..................

The *note curses: 2f. module defines the following data members:

 -- Dati: curses.ERR

     Some curses routines that return an integer, such as *note getch():
     180d, return *note ERR: 34e1. upon failure.

 -- Dati: curses.OK

     Some curses routines that return an integer, such as *note napms():
     18f6, return *note OK: 34e2. upon success.

 -- Dati: curses.version

     A bytes object representing the current version of the module.

 -- Dati: curses.ncurses_version

     A named tuple containing the three components of the ncurses
     library version: 'major', 'minor', and 'patch'.  All values are
     integers.  The components can also be accessed by name, so
     ‘curses.ncurses_version[0]’ is equivalent to
     ‘curses.ncurses_version.major’ and so on.

     Availability: if the ncurses library is used.

     Added in version 3.8.

 -- Dati: curses.COLORS

     The maximum number of colors the terminal can support.  It is
     defined only after the call to *note start_color(): 348c.

 -- Dati: curses.COLOR_PAIRS

     The maximum number of color pairs the terminal can support.  It is
     defined only after the call to *note start_color(): 348c.

 -- Dati: curses.COLS

     The width of the screen, i.e., the number of columns.  It is
     defined only after the call to *note initscr(): 18f7.  Updated by
     *note update_lines_cols(): fed, *note resizeterm(): 1917. and *note
     resize_term(): 1918.

 -- Dati: curses.LINES

     The height of the screen, i.e., the number of lines.  It is defined
     only after the call to *note initscr(): 18f7.  Updated by *note
     update_lines_cols(): fed, *note resizeterm(): 1917. and *note
     resize_term(): 1918.

Some constants are available to specify character cell attributes.  The
exact constants available are system dependent.

Attribute                    Meaning
                             
-----------------------------------------------------------------
                             
 -- Dati:                    Alternate character set mode
          curses.A_ALTCHARSET

 -- Dati: curses.A_BLINK     Blink mode
                             
                             
 -- Dati: curses.A_BOLD      Bold mode
                             
                             
 -- Dati: curses.A_DIM       Dim mode
                             
                             
 -- Dati: curses.A_INVIS     Invisible or blank mode
                             
                             
 -- Dati: curses.A_ITALIC    Italic mode
                             
                             
 -- Dati: curses.A_NORMAL    Normal attribute
                             
                             
 -- Dati: curses.A_PROTECT   Protected mode
                             
                             
 -- Dati: curses.A_REVERSE   Reverse background and foreground
                             colors
                             
                             
 -- Dati:                    Standout mode
          curses.A_STANDOUT  

 -- Dati:                    Underline mode
          curses.A_UNDERLINE 

 -- Dati:                    Horizontal highlight
          curses.A_HORIZONTAL

 -- Dati: curses.A_LEFT      Left highlight
                             
                             
 -- Dati: curses.A_LOW       Low highlight
                             
                             
 -- Dati: curses.A_RIGHT     Right highlight
                             
                             
 -- Dati: curses.A_TOP       Top highlight
                             
                             
 -- Dati:                    Vertical highlight
          curses.A_VERTICAL  

Added in version 3.7: ‘A_ITALIC’ was added.

Several constants are available to extract corresponding attributes
returned by some methods.

Bit-mask                      Meaning
                              
------------------------------------------------------------------
                              
 -- Dati:                     Bit-mask to extract attributes
          curses.A_ATTRIBUTES 

 -- Dati: curses.A_CHARTEXT   Bit-mask to extract a character
                              
                              
 -- Dati: curses.A_COLOR      Bit-mask to extract color-pair
                              field information
                              

Keys are referred to by integer constants with names starting with
‘KEY_’.  The exact keycaps available are system dependent.

Key constant                  Key
                              
-------------------------------------------------------------------------------
                              
 -- Dati: curses.KEY_MIN      Minimum key value
                              
                              
 -- Dati: curses.KEY_BREAK    Break key (unreliable)
                              
                              
 -- Dati: curses.KEY_DOWN     Down-arrow
                              
                              
 -- Dati: curses.KEY_UP       Up-arrow
                              
                              
 -- Dati: curses.KEY_LEFT     Left-arrow
                              
                              
 -- Dati: curses.KEY_RIGHT    Right-arrow
                              
                              
 -- Dati: curses.KEY_HOME     Home key (upward+left arrow)
                              
                              
 -- Dati:                     Backspace (unreliable)
          curses.KEY_BACKSPACE

 -- Dati: curses.KEY_F0       Function keys.  Up to 64 function keys are
                              supported.
                              
                              
 -- Dati: curses.KEY_Fn       Value of function key 'n'
                              
                              
 -- Dati: curses.KEY_DL       Delete line
                              
                              
 -- Dati: curses.KEY_IL       Insert line
                              
                              
 -- Dati: curses.KEY_DC       Delete character
                              
                              
 -- Dati: curses.KEY_IC       Insert char or enter insert mode
                              
                              
 -- Dati: curses.KEY_EIC      Exit insert char mode
                              
                              
 -- Dati: curses.KEY_CLEAR    Clear screen
                              
                              
 -- Dati: curses.KEY_EOS      Clear to end of screen
                              
                              
 -- Dati: curses.KEY_EOL      Clear to end of line
                              
                              
 -- Dati: curses.KEY_SF       Scroll 1 line forward
                              
                              
 -- Dati: curses.KEY_SR       Scroll 1 line backward (reverse)
                              
                              
 -- Dati: curses.KEY_NPAGE    Next page
                              
                              
 -- Dati: curses.KEY_PPAGE    Previous page
                              
                              
 -- Dati: curses.KEY_STAB     Set tab
                              
                              
 -- Dati: curses.KEY_CTAB     Clear tab
                              
                              
 -- Dati: curses.KEY_CATAB    Clear all tabs
                              
                              
 -- Dati: curses.KEY_ENTER    Enter or send (unreliable)
                              
                              
 -- Dati: curses.KEY_SRESET   Soft (partial) reset (unreliable)
                              
                              
 -- Dati: curses.KEY_RESET    Reset or hard reset (unreliable)
                              
                              
 -- Dati: curses.KEY_PRINT    Print
                              
                              
 -- Dati: curses.KEY_LL       Home down or bottom (lower left)
                              
                              
 -- Dati: curses.KEY_A1       Upper left of keypad
                              
                              
 -- Dati: curses.KEY_A3       Upper right of keypad
                              
                              
 -- Dati: curses.KEY_B2       Center of keypad
                              
                              
 -- Dati: curses.KEY_C1       Lower left of keypad
                              
                              
 -- Dati: curses.KEY_C3       Lower right of keypad
                              
                              
 -- Dati: curses.KEY_BTAB     Back tab
                              
                              
 -- Dati: curses.KEY_BEG      Beg (beginning)
                              
                              
 -- Dati: curses.KEY_CANCEL   Cancel
                              
                              
 -- Dati: curses.KEY_CLOSE    Close
                              
                              
 -- Dati:                     Cmd (command)
          curses.KEY_COMMAND  

 -- Dati: curses.KEY_COPY     Copy
                              
                              
 -- Dati: curses.KEY_CREATE   Create
                              
                              
 -- Dati: curses.KEY_END      End
                              
                              
 -- Dati: curses.KEY_EXIT     Exit
                              
                              
 -- Dati: curses.KEY_FIND     Find
                              
                              
 -- Dati: curses.KEY_HELP     Help
                              
                              
 -- Dati: curses.KEY_MARK     Mark
                              
                              
 -- Dati:                     Message
          curses.KEY_MESSAGE  

 -- Dati: curses.KEY_MOVE     Move
                              
                              
 -- Dati: curses.KEY_NEXT     Next
                              
                              
 -- Dati: curses.KEY_OPEN     Open
                              
                              
 -- Dati:                     Options
          curses.KEY_OPTIONS  

 -- Dati:                     Prev (previous)
          curses.KEY_PREVIOUS 

 -- Dati: curses.KEY_REDO     Redo
                              
                              
 -- Dati:                     Ref (reference)
          curses.KEY_REFERENCE

 -- Dati:                     Refresh
          curses.KEY_REFRESH  

 -- Dati:                     Replace
          curses.KEY_REPLACE  

 -- Dati:                     Restart
          curses.KEY_RESTART  

 -- Dati: curses.KEY_RESUME   Resume
                              
                              
 -- Dati: curses.KEY_SAVE     Save
                              
                              
 -- Dati: curses.KEY_SBEG     Shifted Beg (beginning)
                              
                              
 -- Dati:                     Shifted Cancel
          curses.KEY_SCANCEL  

 -- Dati:                     Shifted Command
          curses.KEY_SCOMMAND 

 -- Dati: curses.KEY_SCOPY    Shifted Copy
                              
                              
 -- Dati:                     Shifted Create
          curses.KEY_SCREATE  

 -- Dati: curses.KEY_SDC      Shifted Delete char
                              
                              
 -- Dati: curses.KEY_SDL      Shifted Delete line
                              
                              
 -- Dati: curses.KEY_SELECT   Select
                              
                              
 -- Dati: curses.KEY_SEND     Shifted End
                              
                              
 -- Dati: curses.KEY_SEOL     Shifted Clear line
                              
                              
 -- Dati: curses.KEY_SEXIT    Shifted Exit
                              
                              
 -- Dati: curses.KEY_SFIND    Shifted Find
                              
                              
 -- Dati: curses.KEY_SHELP    Shifted Help
                              
                              
 -- Dati: curses.KEY_SHOME    Shifted Home
                              
                              
 -- Dati: curses.KEY_SIC      Shifted Input
                              
                              
 -- Dati: curses.KEY_SLEFT    Shifted Left arrow
                              
                              
 -- Dati:                     Shifted Message
          curses.KEY_SMESSAGE 

 -- Dati: curses.KEY_SMOVE    Shifted Move
                              
                              
 -- Dati: curses.KEY_SNEXT    Shifted Next
                              
                              
 -- Dati:                     Shifted Options
          curses.KEY_SOPTIONS 

 -- Dati:                     Shifted Prev
          curses.KEY_SPREVIOUS

 -- Dati: curses.KEY_SPRINT   Shifted Print
                              
                              
 -- Dati: curses.KEY_SREDO    Shifted Redo
                              
                              
 -- Dati:                     Shifted Replace
          curses.KEY_SREPLACE 

 -- Dati: curses.KEY_SRIGHT   Shifted Right arrow
                              
                              
 -- Dati: curses.KEY_SRSUME   Shifted Resume
                              
                              
 -- Dati: curses.KEY_SSAVE    Shifted Save
                              
                              
 -- Dati:                     Shifted Suspend
          curses.KEY_SSUSPEND 

 -- Dati: curses.KEY_SUNDO    Shifted Undo
                              
                              
 -- Dati:                     Suspend
          curses.KEY_SUSPEND  

 -- Dati: curses.KEY_UNDO     Undo
                              
                              
 -- Dati: curses.KEY_MOUSE    Mouse event has occurred
                              
                              
 -- Dati: curses.KEY_RESIZE   Terminal resize event
                              
                              
 -- Dati: curses.KEY_MAX      Maximum key value
                              

On VT100s and their software emulations, such as X terminal emulators,
there are normally at least four function keys (*note KEY_F1: 34fe,
*note KEY_F2: 34fe, *note KEY_F3: 34fe, *note KEY_F4: 34fe.) available,
and the arrow keys mapped to *note KEY_UP: 34f8, *note KEY_DOWN: 34f7,
*note KEY_LEFT: 34f9. and *note KEY_RIGHT: 34fa. in the obvious way.  If
your machine has a PC keyboard, it is safe to expect arrow keys and
twelve function keys (older PC keyboards may have only ten function
keys); also, the following keypad mappings are standard:

Keycap                 Constant
                       
---------------------------------------
                       
‘Insert’               KEY_IC
                       
                       
‘Delete’               KEY_DC
                       
                       
‘Home’                 KEY_HOME
                       
                       
‘End’                  KEY_END
                       
                       
‘Page Up’              KEY_PPAGE
                       
                       
‘Page Down’            KEY_NPAGE
                       

The following table lists characters from the alternate character set.
These are inherited from the VT100 terminal, and will generally be
available on software emulations such as X terminals.  When there is no
graphic available, curses falls back on a crude printable ASCII
approximation.

     Nota: These are available only after *note initscr(): 18f7. has
     been called.

ACS code                     Meaning
                             
----------------------------------------------------------------------------
                             
 -- Dati: curses.ACS_BBSS    alternate name for upper right corner
                             
                             
 -- Dati: curses.ACS_BLOCK   solid square block
                             
                             
 -- Dati: curses.ACS_BOARD   board of squares
                             
                             
 -- Dati: curses.ACS_BSBS    alternate name for horizontal line
                             
                             
 -- Dati: curses.ACS_BSSB    alternate name for upper left corner
                             
                             
 -- Dati: curses.ACS_BSSS    alternate name for top tee
                             
                             
 -- Dati: curses.ACS_BTEE    bottom tee
                             
                             
 -- Dati:                    bullet
          curses.ACS_BULLET  

 -- Dati:                    checker board (stipple)
          curses.ACS_CKBOARD 

 -- Dati:                    arrow pointing down
          curses.ACS_DARROW  

 -- Dati:                    degree symbol
          curses.ACS_DEGREE  

 -- Dati:                    diamond
          curses.ACS_DIAMOND 

 -- Dati:                    greater-than-or-equal-to
          curses.ACS_GEQUAL  

 -- Dati: curses.ACS_HLINE   horizontal line
                             
                             
 -- Dati:                    lantern symbol
          curses.ACS_LANTERN 

 -- Dati:                    left arrow
          curses.ACS_LARROW  

 -- Dati:                    less-than-or-equal-to
          curses.ACS_LEQUAL  

 -- Dati:                    lower left-hand corner
          curses.ACS_LLCORNER

 -- Dati:                    lower right-hand corner
          curses.ACS_LRCORNER

 -- Dati: curses.ACS_LTEE    left tee
                             
                             
 -- Dati:                    not-equal sign
          curses.ACS_NEQUAL  

 -- Dati: curses.ACS_PI      letter pi
                             
                             
 -- Dati:                    plus-or-minus sign
          curses.ACS_PLMINUS 

 -- Dati: curses.ACS_PLUS    big plus sign
                             
                             
 -- Dati:                    right arrow
          curses.ACS_RARROW  

 -- Dati: curses.ACS_RTEE    right tee
                             
                             
 -- Dati: curses.ACS_S1      scan line 1
                             
                             
 -- Dati: curses.ACS_S3      scan line 3
                             
                             
 -- Dati: curses.ACS_S7      scan line 7
                             
                             
 -- Dati: curses.ACS_S9      scan line 9
                             
                             
 -- Dati: curses.ACS_SBBS    alternate name for lower right corner
                             
                             
 -- Dati: curses.ACS_SBSB    alternate name for vertical line
                             
                             
 -- Dati: curses.ACS_SBSS    alternate name for right tee
                             
                             
 -- Dati: curses.ACS_SSBB    alternate name for lower left corner
                             
                             
 -- Dati: curses.ACS_SSBS    alternate name for bottom tee
                             
                             
 -- Dati: curses.ACS_SSSB    alternate name for left tee
                             
                             
 -- Dati: curses.ACS_SSSS    alternate name for crossover or big plus
                             
                             
 -- Dati:                    pound sterling
          curses.ACS_STERLING

 -- Dati: curses.ACS_TTEE    top tee
                             
                             
 -- Dati:                    up arrow
          curses.ACS_UARROW  

 -- Dati:                    upper left corner
          curses.ACS_ULCORNER

 -- Dati:                    upper right corner
          curses.ACS_URCORNER

 -- Dati: curses.ACS_VLINE   vertical line
                             

The following table lists mouse button constants used by *note
getmouse(): 3463.:

Mouse button constant                  Meaning
                                       
-----------------------------------------------------------------------------------------
                                       
 -- Dati: curses.BUTTONn_PRESSED       Mouse button 'n' pressed
                                       
                                       
 -- Dati: curses.BUTTONn_RELEASED      Mouse button 'n' released
                                       
                                       
 -- Dati: curses.BUTTONn_CLICKED       Mouse button 'n' clicked
                                       
                                       
 -- Dati:                              Mouse button 'n' double clicked
          curses.BUTTONn_DOUBLE_CLICKED

 -- Dati:                              Mouse button 'n' triple clicked
          curses.BUTTONn_TRIPLE_CLICKED

 -- Dati: curses.BUTTON_SHIFT          Shift was down during button state change
                                       
                                       
 -- Dati: curses.BUTTON_CTRL           Control was down during button state change
                                       
                                       
 -- Dati: curses.BUTTON_ALT            Control was down during button state change
                                       

Cambiato nella versione 3.10: The ‘BUTTON5_*’ constants are now exposed
if they are provided by the underlying curses library.

The following table lists the predefined colors:

Constant                      Color
                              
---------------------------------------------------------------
                              
 -- Dati:                     Black
          curses.COLOR_BLACK  

 -- Dati: curses.COLOR_BLUE   Blue
                              
                              
 -- Dati: curses.COLOR_CYAN   Cyan (light greenish blue)
                              
                              
 -- Dati:                     Green
          curses.COLOR_GREEN  

 -- Dati:                     Magenta (purplish red)
          curses.COLOR_MAGENTA

 -- Dati: curses.COLOR_RED    Red
                              
                              
 -- Dati:                     White
          curses.COLOR_WHITE  

 -- Dati:                     Yellow
          curses.COLOR_YELLOW 


File: python.info,  Node: curses textpad — Text input widget for curses programs,  Next: curses ascii — Utilities for ASCII characters,  Prev: curses — Terminal handling for character-cell displays,  Up: Command-line interface libraries

5.17.6 ‘curses.textpad’ — Text input widget for curses programs
---------------------------------------------------------------

The *note curses.textpad: 32. module provides a *note Textbox: 3581.
class that handles elementary text editing in a curses window,
supporting a set of keybindings resembling those of Emacs (thus, also of
Netscape Navigator, BBedit 6.x, FrameMaker, and many other programs).
The module also provides a rectangle-drawing function useful for framing
text boxes or for other purposes.

The module *note curses.textpad: 32. defines the following function:

 -- Funzione: curses.textpad.rectangle (win, uly, ulx, lry, lrx)

     Draw a rectangle.  The first argument must be a window object; the
     remaining arguments are coordinates relative to that window.  The
     second and third arguments are the y and x coordinates of the upper
     left hand corner of the rectangle to be drawn; the fourth and fifth
     arguments are the y and x coordinates of the lower right hand
     corner.  The rectangle will be drawn using VT100/IBM PC forms
     characters on terminals that make this possible (including xterm
     and most other software terminal emulators).  Otherwise it will be
     drawn with ASCII dashes, vertical bars, and plus signs.

* Menu:

* Textbox objects::


File: python.info,  Node: Textbox objects,  Up: curses textpad — Text input widget for curses programs

5.17.6.1 Textbox objects
........................

You can instantiate a *note Textbox: 3581. object as follows:

 -- Classe: curses.textpad.Textbox (win)

     Return a textbox widget object.  The 'win' argument should be a
     curses *note window: 1971. object in which the textbox is to be
     contained.  The edit cursor of the textbox is initially located at
     the upper left hand corner of the containing window, with
     coordinates ‘(0, 0)’.  The instance’s *note stripspaces: 3585. flag
     is initially on.

     *note Textbox: 3581. objects have the following methods:

      -- Metodo: edit ([validator])

          This is the entry point you will normally use.  It accepts
          editing keystrokes until one of the termination keystrokes is
          entered.  If 'validator' is supplied, it must be a function.
          It will be called for each keystroke entered with the
          keystroke as a parameter; command dispatch is done on the
          result.  This method returns the window contents as a string;
          whether blanks in the window are included is affected by the
          *note stripspaces: 3585. attribute.

      -- Metodo: do_command (ch)

          Process a single command keystroke.  Here are the supported
          special keystrokes:

          Keystroke              Action
                                 
          -----------------------------------------------------------------------
                                 
          ‘Control’-‘A’          Go to left edge of window.
                                 
                                 
          ‘Control’-‘B’          Cursor left, wrapping to previous line if
                                 appropriate.
                                 
                                 
          ‘Control’-‘D’          Delete character under cursor.
                                 
                                 
          ‘Control’-‘E’          Go to right edge (stripspaces off) or end of
                                 line (stripspaces on).
                                 
                                 
          ‘Control’-‘F’          Cursor right, wrapping to next line when
                                 appropriate.
                                 
                                 
          ‘Control’-‘G’          Terminate, returning the window contents.
                                 
                                 
          ‘Control’-‘H’          Delete character backward.
                                 
                                 
          ‘Control’-‘J’          Terminate if the window is 1 line, otherwise
                                 insert newline.
                                 
                                 
          ‘Control’-‘K’          If line is blank, delete it, otherwise clear
                                 to end of line.
                                 
                                 
          ‘Control’-‘L’          Refresh screen.
                                 
                                 
          ‘Control’-‘N’          Cursor down; move down one line.
                                 
                                 
          ‘Control’-‘O’          Insert a blank line at cursor location.
                                 
                                 
          ‘Control’-‘P’          Cursor up; move up one line.
                                 

          Move operations do nothing if the cursor is at an edge where
          the movement is not possible.  The following synonyms are
          supported where possible:

          Constant                             Keystroke
                                               
          ------------------------------------------------------------
                                               
          *note KEY_LEFT: 34f9.                ‘Control’-‘B’
                                               
                                               
          *note KEY_RIGHT: 34fa.               ‘Control’-‘F’
                                               
                                               
          *note KEY_UP: 34f8.                  ‘Control’-‘P’
                                               
                                               
          *note KEY_DOWN: 34f7.                ‘Control’-‘N’
                                               
                                               
          *note KEY_BACKSPACE: 34fc.           ‘Control’-‘h’
                                               

          All other keystrokes are treated as a command to insert the
          given character and move right (with line wrapping).

      -- Metodo: gather ()

          Return the window contents as a string; whether blanks in the
          window are included is affected by the *note stripspaces:
          3585. member.

      -- Attributo: stripspaces

          This attribute is a flag which controls the interpretation of
          blanks in the window.  When it is on, trailing blanks on each
          line are ignored; any cursor motion that would land the cursor
          on a trailing blank goes to the end of that line instead, and
          trailing blanks are stripped when the window contents are
          gathered.


File: python.info,  Node: curses ascii — Utilities for ASCII characters,  Next: curses panel — A panel stack extension for curses,  Prev: curses textpad — Text input widget for curses programs,  Up: Command-line interface libraries

5.17.7 ‘curses.ascii’ — Utilities for ASCII characters
------------------------------------------------------

'Source code:' Lib/curses/ascii.py(1)

__________________________________________________________________

The *note curses.ascii: 30. module supplies name constants for ASCII
characters and functions to test membership in various ASCII character
classes.  The constants supplied are names for control characters as
follows:

Name                Meaning
                    
-----------------------------------------------------------------------
                    
 -- Dati:
          curses.ascii.NUL

 -- Dati:           Start of heading, console interrupt
          curses.ascii.SOH

 -- Dati:           Start of text
          curses.ascii.STX

 -- Dati:           End of text
          curses.ascii.ETX

 -- Dati:           End of transmission
          curses.ascii.EOT

 -- Dati:           Enquiry, goes with *note ACK: 3592. flow control
          curses.ascii.ENQ

 -- Dati:           Acknowledgement
          curses.ascii.ACK

 -- Dati:           Bell
          curses.ascii.BEL

 -- Dati:           Backspace
          curses.ascii.BS

 -- Dati:           Tab
          curses.ascii.TAB

 -- Dati:           Alias for *note TAB: 3595.: «Horizontal tab»
          curses.ascii.HT

 -- Dati:           Line feed
          curses.ascii.LF

 -- Dati:           Alias for *note LF: 3597.: «New line»
          curses.ascii.NL

 -- Dati:           Vertical tab
          curses.ascii.VT

 -- Dati:           Form feed
          curses.ascii.FF

 -- Dati:           Carriage return
          curses.ascii.CR

 -- Dati:           Shift-out, begin alternate character set
          curses.ascii.SO

 -- Dati:           Shift-in, resume default character set
          curses.ascii.SI

 -- Dati:           Data-link escape
          curses.ascii.DLE

 -- Dati:           XON, for flow control
          curses.ascii.DC1

 -- Dati:           Device control 2, block-mode flow control
          curses.ascii.DC2

 -- Dati:           XOFF, for flow control
          curses.ascii.DC3

 -- Dati:           Device control 4
          curses.ascii.DC4

 -- Dati:           Negative acknowledgement
          curses.ascii.NAK

 -- Dati:           Synchronous idle
          curses.ascii.SYN

 -- Dati:           End transmission block
          curses.ascii.ETB

 -- Dati:           Cancel
          curses.ascii.CAN

 -- Dati:           End of medium
          curses.ascii.EM

 -- Dati:           Substitute
          curses.ascii.SUB

 -- Dati:           Escape
          curses.ascii.ESC

 -- Dati:           File separator
          curses.ascii.FS

 -- Dati:           Group separator
          curses.ascii.GS

 -- Dati:           Record separator, block-mode terminator
          curses.ascii.RS

 -- Dati:           Unit separator
          curses.ascii.US

 -- Dati:           Space
          curses.ascii.SP

 -- Dati:           Delete
          curses.ascii.DEL

Note that many of these have little practical significance in modern
usage.  The mnemonics derive from teleprinter conventions that predate
digital computers.

The module supplies the following functions, patterned on those in the
standard C library:

 -- Funzione: curses.ascii.isalnum (c)

     Checks for an ASCII alphanumeric character; it is equivalent to
     ‘isalpha(c) or isdigit(c)’.

 -- Funzione: curses.ascii.isalpha (c)

     Checks for an ASCII alphabetic character; it is equivalent to
     ‘isupper(c) or islower(c)’.

 -- Funzione: curses.ascii.isascii (c)

     Checks for a character value that fits in the 7-bit ASCII set.

 -- Funzione: curses.ascii.isblank (c)

     Checks for an ASCII whitespace character; space or horizontal tab.

 -- Funzione: curses.ascii.iscntrl (c)

     Checks for an ASCII control character (in the range 0x00 to 0x1f or
     0x7f).

 -- Funzione: curses.ascii.isdigit (c)

     Checks for an ASCII decimal digit, ‘'0'’ through ‘'9'’.  This is
     equivalent to ‘c in string.digits’.

 -- Funzione: curses.ascii.isgraph (c)

     Checks for ASCII any printable character except space.

 -- Funzione: curses.ascii.islower (c)

     Checks for an ASCII lower-case character.

 -- Funzione: curses.ascii.isprint (c)

     Checks for any ASCII printable character including space.

 -- Funzione: curses.ascii.ispunct (c)

     Checks for any printable ASCII character which is not a space or an
     alphanumeric character.

 -- Funzione: curses.ascii.isspace (c)

     Checks for ASCII white-space characters; space, line feed, carriage
     return, form feed, horizontal tab, vertical tab.

 -- Funzione: curses.ascii.isupper (c)

     Checks for an ASCII uppercase letter.

 -- Funzione: curses.ascii.isxdigit (c)

     Checks for an ASCII hexadecimal digit.  This is equivalent to ‘c in
     string.hexdigits’.

 -- Funzione: curses.ascii.isctrl (c)

     Checks for an ASCII control character (ordinal values 0 to 31).

 -- Funzione: curses.ascii.ismeta (c)

     Checks for a non-ASCII character (ordinal values 0x80 and above).

These functions accept either integers or single-character strings; when
the argument is a string, it is first converted using the built-in
function *note ord(): 2323.

Note that all these functions check ordinal bit values derived from the
character of the string you pass in; they do not actually know anything
about the host machine’s character encoding.

The following two functions take either a single-character string or
integer byte value; they return a value of the same type.

 -- Funzione: curses.ascii.ascii (c)

     Return the ASCII value corresponding to the low 7 bits of 'c'.

 -- Funzione: curses.ascii.ctrl (c)

     Return the control character corresponding to the given character
     (the character bit value is bitwise-anded with 0x1f).

 -- Funzione: curses.ascii.alt (c)

     Return the 8-bit character corresponding to the given ASCII
     character (the character bit value is bitwise-ored with 0x80).

The following function takes either a single-character string or integer
value; it returns a string.

 -- Funzione: curses.ascii.unctrl (c)

     Return a string representation of the ASCII character 'c'.  If 'c'
     is printable, this string is the character itself.  If the
     character is a control character (0x00–0x1f) the string consists of
     a caret (‘'^'’) followed by the corresponding uppercase letter.  If
     the character is an ASCII delete (0x7f) the string is ‘'^?'’.  If
     the character has its meta bit (0x80) set, the meta bit is
     stripped, the preceding rules applied, and ‘'!'’ prepended to the
     result.

 -- Dati: curses.ascii.controlnames

     A 33-element string array that contains the ASCII mnemonics for the
     thirty-two ASCII control characters from 0 (NUL) to 0x1f (US), in
     order, plus the mnemonic ‘SP’ for the space character.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/curses/ascii.py


File: python.info,  Node: curses panel — A panel stack extension for curses,  Next: cmd — Support for line-oriented command interpreters,  Prev: curses ascii — Utilities for ASCII characters,  Up: Command-line interface libraries

5.17.8 ‘curses.panel’ — A panel stack extension for curses
----------------------------------------------------------

__________________________________________________________________

Panels are windows with the added feature of depth, so they can be
stacked on top of each other, and only the visible portions of each
window will be displayed.  Panels can be added, moved up or down in the
stack, and removed.

* Menu:

* Functions: Functions<6>.
* Panel Objects::


File: python.info,  Node: Functions<6>,  Next: Panel Objects,  Up: curses panel — A panel stack extension for curses

5.17.8.1 Functions
..................

The module *note curses.panel: 31. defines the following functions:

 -- Funzione: curses.panel.bottom_panel ()

     Returns the bottom panel in the panel stack.

 -- Funzione: curses.panel.new_panel (win)

     Returns a panel object, associating it with the given window 'win'.
     Be aware that you need to keep the returned panel object referenced
     explicitly.  If you don’t, the panel object is garbage collected
     and removed from the panel stack.

 -- Funzione: curses.panel.top_panel ()

     Returns the top panel in the panel stack.

 -- Funzione: curses.panel.update_panels ()

     Updates the virtual screen after changes in the panel stack.  This
     does not call *note curses.doupdate(): 3459, so you’ll have to do
     this yourself.


File: python.info,  Node: Panel Objects,  Prev: Functions<6>,  Up: curses panel — A panel stack extension for curses

5.17.8.2 Panel Objects
......................

Panel objects, as returned by *note new_panel(): 35ca. above, are
windows with a stacking order.  There’s always a window associated with
a panel which determines the content, while the panel methods are
responsible for the window’s depth in the panel stack.

Panel objects have the following methods:

 -- Metodo: Panel.above ()

     Returns the panel above the current panel.

 -- Metodo: Panel.below ()

     Returns the panel below the current panel.

 -- Metodo: Panel.bottom ()

     Push the panel to the bottom of the stack.

 -- Metodo: Panel.hidden ()

     Returns ‘True’ if the panel is hidden (not visible), ‘False’
     otherwise.

 -- Metodo: Panel.hide ()

     Hide the panel.  This does not delete the object, it just makes the
     window on screen invisible.

 -- Metodo: Panel.move (y, x)

     Move the panel to the screen coordinates ‘(y, x)’.

 -- Metodo: Panel.replace (win)

     Change the window associated with the panel to the window 'win'.

 -- Metodo: Panel.set_userptr (obj)

     Set the panel’s user pointer to 'obj'.  This is used to associate
     an arbitrary piece of data with the panel, and can be any Python
     object.

 -- Metodo: Panel.show ()

     Display the panel (which might have been hidden).

 -- Metodo: Panel.top ()

     Push panel to the top of the stack.

 -- Metodo: Panel.userptr ()

     Returns the user pointer for the panel.  This might be any Python
     object.

 -- Metodo: Panel.window ()

     Returns the window object associated with the panel.


File: python.info,  Node: cmd — Support for line-oriented command interpreters,  Prev: curses panel — A panel stack extension for curses,  Up: Command-line interface libraries

5.17.9 ‘cmd’ — Support for line-oriented command interpreters
-------------------------------------------------------------

'Source code:' Lib/cmd.py(1)

__________________________________________________________________

The *note Cmd: 1836. class provides a simple framework for writing
line-oriented command interpreters.  These are often useful for test
harnesses, administrative tools, and prototypes that will later be
wrapped in a more sophisticated interface.

 -- Classe: cmd.Cmd (completekey='tab', stdin=None, stdout=None)

     A *note Cmd: 1836. instance or subclass instance is a line-oriented
     interpreter framework.  There is no good reason to instantiate
     *note Cmd: 1836. itself; rather, it’s useful as a superclass of an
     interpreter class you define yourself in order to inherit *note
     Cmd: 1836.’s methods and encapsulate action methods.

     The optional argument 'completekey' is the *note readline: bf. name
     of a completion key; it defaults to ‘Tab’.  If 'completekey' is not
     *note None: 886. and *note readline: bf. is available, command
     completion is done automatically.

     The default, ‘'tab'’, is treated specially, so that it refers to
     the ‘Tab’ key on every *note readline.backend: 1a0f.  Specifically,
     if *note readline.backend: 1a0f. is ‘editline’, ‘Cmd’ will use
     ‘'^I'’ instead of ‘'tab'’.  Note that other values are not treated
     this way, and might only work with a specific backend.

     The optional arguments 'stdin' and 'stdout' specify the input and
     output file objects that the Cmd instance or subclass instance will
     use for input and output.  If not specified, they will default to
     *note sys.stdin: 760. and *note sys.stdout: ccf.

     If you want a given 'stdin' to be used, make sure to set the
     instance’s *note use_rawinput: 35de. attribute to ‘False’,
     otherwise 'stdin' will be ignored.

     Cambiato nella versione 3.13: ‘completekey='tab'’ is replaced by
     ‘'^I'’ for ‘editline’.

* Menu:

* Cmd Objects::
* Cmd Example::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/cmd.py


File: python.info,  Node: Cmd Objects,  Next: Cmd Example,  Up: cmd — Support for line-oriented command interpreters

5.17.9.1 Cmd Objects
....................

A *note Cmd: 1836. instance has the following methods:

 -- Metodo: Cmd.cmdloop (intro=None)

     Repeatedly issue a prompt, accept input, parse an initial prefix
     off the received input, and dispatch to action methods, passing
     them the remainder of the line as argument.

     The optional argument is a banner or intro string to be issued
     before the first prompt (this overrides the *note intro: 35e2.
     class attribute).

     If the *note readline: bf. module is loaded, input will
     automatically inherit ‘bash’-like history-list editing (e.g.
     ‘Control’-‘P’ scrolls back to the last command, ‘Control’-‘N’
     forward to the next one, ‘Control’-‘F’ moves the cursor to the
     right non-destructively, ‘Control’-‘B’ moves the cursor to the left
     non-destructively, etc.).

     An end-of-file on input is passed back as the string ‘'EOF'’.

     An interpreter instance will recognize a command name ‘foo’ if and
     only if it has a method ‘do_foo()’.  As a special case, a line
     beginning with the character ‘'?'’ is dispatched to the method
     *note do_help(): 1a13.  As another special case, a line beginning
     with the character ‘'!'’ is dispatched to the method ‘do_shell()’
     (if such a method is defined).

     This method will return when the *note postcmd(): 35e3. method
     returns a true value.  The 'stop' argument to *note postcmd():
     35e3. is the return value from the command’s corresponding ‘do_*()’
     method.

     If completion is enabled, completing commands will be done
     automatically, and completing of commands args is done by calling
     ‘complete_foo()’ with arguments 'text', 'line', 'begidx', and
     'endidx'.  'text' is the string prefix we are attempting to match:
     all returned matches must begin with it.  'line' is the current
     input line with leading whitespace removed, 'begidx' and 'endidx'
     are the beginning and ending indexes of the prefix text, which
     could be used to provide different completion depending upon which
     position the argument is in.

 -- Metodo: Cmd.do_help (arg)

     All subclasses of *note Cmd: 1836. inherit a predefined
     ‘do_help()’.  This method, called with an argument ‘'bar'’, invokes
     the corresponding method ‘help_bar()’, and if that is not present,
     prints the docstring of ‘do_bar()’, if available.  With no
     argument, ‘do_help()’ lists all available help topics (that is, all
     commands with corresponding ‘help_*()’ methods or commands that
     have docstrings), and also lists any undocumented commands.

 -- Metodo: Cmd.onecmd (str)

     Interpret the argument as though it had been typed in response to
     the prompt.  This may be overridden, but should not normally need
     to be; see the *note precmd(): 35e5. and *note postcmd(): 35e3.
     methods for useful execution hooks.  The return value is a flag
     indicating whether interpretation of commands by the interpreter
     should stop.  If there is a ‘do_*()’ method for the command 'str',
     the return value of that method is returned, otherwise the return
     value from the *note default(): 35e6. method is returned.

 -- Metodo: Cmd.emptyline ()

     Method called when an empty line is entered in response to the
     prompt.  If this method is not overridden, it repeats the last
     nonempty command entered.

 -- Metodo: Cmd.default (line)

     Method called on an input line when the command prefix is not
     recognized.  If this method is not overridden, it prints an error
     message and returns.

 -- Metodo: Cmd.completedefault (text, line, begidx, endidx)

     Method called to complete an input line when no command-specific
     ‘complete_*()’ method is available.  By default, it returns an
     empty list.

 -- Metodo: Cmd.columnize (list, displaywidth=80)

     Method called to display a list of strings as a compact set of
     columns.  Each column is only as wide as necessary.  Columns are
     separated by two spaces for readability.

 -- Metodo: Cmd.precmd (line)

     Hook method executed just before the command line 'line' is
     interpreted, but after the input prompt is generated and issued.
     This method is a stub in *note Cmd: 1836.; it exists to be
     overridden by subclasses.  The return value is used as the command
     which will be executed by the *note onecmd(): 35e4. method; the
     *note precmd(): 35e5. implementation may re-write the command or
     simply return 'line' unchanged.

 -- Metodo: Cmd.postcmd (stop, line)

     Hook method executed just after a command dispatch is finished.
     This method is a stub in *note Cmd: 1836.; it exists to be
     overridden by subclasses.  'line' is the command line which was
     executed, and 'stop' is a flag which indicates whether execution
     will be terminated after the call to *note postcmd(): 35e3.; this
     will be the return value of the *note onecmd(): 35e4. method.  The
     return value of this method will be used as the new value for the
     internal flag which corresponds to 'stop'; returning false will
     cause interpretation to continue.

 -- Metodo: Cmd.preloop ()

     Hook method executed once when *note cmdloop(): 35e1. is called.
     This method is a stub in *note Cmd: 1836.; it exists to be
     overridden by subclasses.

 -- Metodo: Cmd.postloop ()

     Hook method executed once when *note cmdloop(): 35e1. is about to
     return.  This method is a stub in *note Cmd: 1836.; it exists to be
     overridden by subclasses.

Instances of *note Cmd: 1836. subclasses have some public instance
variables:

 -- Attributo: Cmd.prompt

     The prompt issued to solicit input.

 -- Attributo: Cmd.identchars

     The string of characters accepted for the command prefix.

 -- Attributo: Cmd.lastcmd

     The last nonempty command prefix seen.

 -- Attributo: Cmd.cmdqueue

     A list of queued input lines.  The cmdqueue list is checked in
     *note cmdloop(): 35e1. when new input is needed; if it is nonempty,
     its elements will be processed in order, as if entered at the
     prompt.

 -- Attributo: Cmd.intro

     A string to issue as an intro or banner.  May be overridden by
     giving the *note cmdloop(): 35e1. method an argument.

 -- Attributo: Cmd.doc_header

     The header to issue if the help output has a section for documented
     commands.

 -- Attributo: Cmd.misc_header

     The header to issue if the help output has a section for
     miscellaneous help topics (that is, there are ‘help_*()’ methods
     without corresponding ‘do_*()’ methods).

 -- Attributo: Cmd.undoc_header

     The header to issue if the help output has a section for
     undocumented commands (that is, there are ‘do_*()’ methods without
     corresponding ‘help_*()’ methods).

 -- Attributo: Cmd.ruler

     The character used to draw separator lines under the help-message
     headers.  If empty, no ruler line is drawn.  It defaults to ‘'='’.

 -- Attributo: Cmd.use_rawinput

     A flag, defaulting to true.  If true, *note cmdloop(): 35e1. uses
     *note input(): 14e0. to display a prompt and read the next command;
     if false, *note sys.stdout.write(): ccf. and *note
     sys.stdin.readline(): 760. are used.  (This means that by importing
     *note readline: bf, on systems that support it, the interpreter
     will automatically support ‘Emacs’-like line editing and
     command-history keystrokes.)


File: python.info,  Node: Cmd Example,  Prev: Cmd Objects,  Up: cmd — Support for line-oriented command interpreters

5.17.9.2 Cmd Example
....................

The *note cmd: 1a. module is mainly useful for building custom shells
that let a user work with a program interactively.

This section presents a simple example of how to build a shell around a
few of the commands in the *note turtle: 107. module.

Basic turtle commands such as *note forward(): 35f5. are added to a
*note Cmd: 1836. subclass with method named ‘do_forward()’.  The
argument is converted to a number and dispatched to the turtle module.
The docstring is used in the help utility provided by the shell.

The example also includes a basic record and playback facility
implemented with the *note precmd(): 35e5. method which is responsible
for converting the input to lowercase and writing the commands to a
file.  The ‘do_playback()’ method reads the file and adds the recorded
commands to the *note cmdqueue: 35ee. for immediate playback:

     import cmd, sys
     from turtle import *

     class TurtleShell(cmd.Cmd):
         intro = 'Welcome to the turtle shell.   Type help or ? to list commands.\n'
         prompt = '(turtle) '
         file = None

         # ----- basic turtle commands -----
         def do_forward(self, arg):
             'Move the turtle forward by the specified distance:  FORWARD 10'
             forward(*parse(arg))
         def do_right(self, arg):
             'Turn turtle right by given number of degrees:  RIGHT 20'
             right(*parse(arg))
         def do_left(self, arg):
             'Turn turtle left by given number of degrees:  LEFT 90'
             left(*parse(arg))
         def do_goto(self, arg):
             'Move turtle to an absolute position with changing orientation.  GOTO 100 200'
             goto(*parse(arg))
         def do_home(self, arg):
             'Return turtle to the home position:  HOME'
             home()
         def do_circle(self, arg):
             'Draw circle with given radius an options extent and steps:  CIRCLE 50'
             circle(*parse(arg))
         def do_position(self, arg):
             'Print the current turtle position:  POSITION'
             print('Current position is %d %d\n' % position())
         def do_heading(self, arg):
             'Print the current turtle heading in degrees:  HEADING'
             print('Current heading is %d\n' % (heading(),))
         def do_color(self, arg):
             'Set the color:  COLOR BLUE'
             color(arg.lower())
         def do_undo(self, arg):
             'Undo (repeatedly) the last turtle action(s):  UNDO'
         def do_reset(self, arg):
             'Clear the screen and return turtle to center:  RESET'
             reset()
         def do_bye(self, arg):
             'Stop recording, close the turtle window, and exit:  BYE'
             print('Thank you for using Turtle')
             self.close()
             bye()
             return True

         # ----- record and playback -----
         def do_record(self, arg):
             'Save future commands to filename:  RECORD rose.cmd'
             self.file = open(arg, 'w')
         def do_playback(self, arg):
             'Playback commands from a file:  PLAYBACK rose.cmd'
             self.close()
             with open(arg) as f:
                 self.cmdqueue.extend(f.read().splitlines())
         def precmd(self, line):
             line = line.lower()
             if self.file and 'playback' not in line:
                 print(line, file=self.file)
             return line
         def close(self):
             if self.file:
                 self.file.close()
                 self.file = None

     def parse(arg):
         'Convert a series of zero or more numbers to an argument tuple'
         return tuple(map(int, arg.split()))

     if __name__ == '__main__':
         TurtleShell().cmdloop()

Here is a sample session with the turtle shell showing the help
functions, using blank lines to repeat commands, and the simple record
and playback facility:

     Welcome to the turtle shell.   Type help or ? to list commands.

     (turtle) ?

     Documented commands (type help <topic>):
     ========================================
     bye     color    goto     home  playback  record  right
     circle  forward  heading  left  position  reset   undo

     (turtle) help forward
     Move the turtle forward by the specified distance:  FORWARD 10
     (turtle) record spiral.cmd
     (turtle) position
     Current position is 0 0

     (turtle) heading
     Current heading is 0

     (turtle) reset
     (turtle) circle 20
     (turtle) right 30
     (turtle) circle 40
     (turtle) right 30
     (turtle) circle 60
     (turtle) right 30
     (turtle) circle 80
     (turtle) right 30
     (turtle) circle 100
     (turtle) right 30
     (turtle) circle 120
     (turtle) right 30
     (turtle) circle 120
     (turtle) heading
     Current heading is 180

     (turtle) forward 100
     (turtle)
     (turtle) right 90
     (turtle) forward 100
     (turtle)
     (turtle) right 90
     (turtle) forward 400
     (turtle) right 90
     (turtle) forward 500
     (turtle) right 90
     (turtle) forward 400
     (turtle) right 90
     (turtle) forward 300
     (turtle) playback spiral.cmd
     Current position is 0 0

     Current heading is 0

     Current heading is 180

     (turtle) bye
     Thank you for using Turtle


File: python.info,  Node: Concurrent Execution,  Next: Networking and Interprocess Communication,  Prev: Command-line interface libraries,  Up: The Python Standard Library

5.18 Concurrent Execution
=========================

The modules described in this chapter provide support for concurrent
execution of code.  The appropriate choice of tool will depend on the
task to be executed (CPU bound vs IO bound) and preferred style of
development (event driven cooperative multitasking vs preemptive
multitasking).  Here’s an overview:

* Menu:

* threading — Thread-based parallelism::
* multiprocessing — Process-based parallelism::
* multiprocessing.shared_memory — Shared memory for direct access across processes: multiprocessing shared_memory — Shared memory for direct access across processes.
* The concurrent package::
* concurrent.futures — Launching parallel tasks: concurrent futures — Launching parallel tasks.
* concurrent.interpreters — Multiple interpreters in the same process: concurrent interpreters — Multiple interpreters in the same process.
* subprocess — Subprocess management::
* sched — Event scheduler::
* queue — A synchronized queue class::
* contextvars — Context Variables::
* _thread — Low-level threading API::


File: python.info,  Node: threading — Thread-based parallelism,  Next: multiprocessing — Process-based parallelism,  Up: Concurrent Execution

5.18.1 ‘threading’ — Thread-based parallelism
---------------------------------------------

'Source code:' Lib/threading.py(1)

__________________________________________________________________

This module constructs higher-level threading interfaces on top of the
lower level *note _thread: 2. module.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

* Menu:

* Introduction: Introduction<7>.
* GIL and performance considerations::
* Reference: Reference<2>.
* Using locks, conditions, and semaphores in the with statement: Using locks conditions and semaphores in the with statement.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/threading.py


File: python.info,  Node: Introduction<7>,  Next: GIL and performance considerations,  Up: threading — Thread-based parallelism

5.18.1.1 Introduction
.....................

The ‘threading’ module provides a way to run multiple threads(1)
(smaller units of a process) concurrently within a single process.  It
allows for the creation and management of threads, making it possible to
execute tasks in parallel, sharing memory space.  Threads are
particularly useful when tasks are I/O bound, such as file operations or
making network requests, where much of the time is spent waiting for
external resources.

A typical use case for ‘threading’ includes managing a pool of worker
threads that can process multiple tasks concurrently.  Here’s a basic
example of creating and starting threads using *note Thread: 176.:

     import threading
     import time

     def crawl(link, delay=3):
         print(f"crawl started for {link}")
         time.sleep(delay)  # Blocking I/O (simulating a network request)
         print(f"crawl ended for {link}")

     links = [
         "https://python.org",
         "https://docs.python.org",
         "https://peps.python.org",
     ]

     # Start threads for each link
     threads = []
     for link in links:
         # Using `args` to pass positional arguments and `kwargs` for keyword arguments
         t = threading.Thread(target=crawl, args=(link,), kwargs={"delay": 2})
         threads.append(t)

     # Start each thread
     for t in threads:
         t.start()

     # Wait for all threads to finish
     for t in threads:
         t.join()

Cambiato nella versione 3.7: This module used to be optional, it is now
always available.

Vedi anche
..........

*note concurrent.futures.ThreadPoolExecutor: 94a. offers a higher level
interface to push tasks to a background thread without blocking
execution of the calling thread, while still being able to retrieve
their results when needed.

*note queue: bb. provides a thread-safe interface for exchanging data
between running threads.

*note asyncio: b. offers an alternative approach to achieving task level
concurrency without requiring the use of multiple operating system
threads.

     Nota: In the Python 2.x series, this module contained ‘camelCase’
     names for some methods and functions.  These are deprecated as of
     Python 3.10, but they are still supported for compatibility with
     Python 2.5 and lower.

'Dettaglio dell’implementazione di CPython:' In CPython, due to the
*note Global Interpreter Lock: 474, only one thread can execute Python
code at once (even though certain performance-oriented libraries might
overcome this limitation).  If you want your application to make better
use of the computational resources of multi-core machines, you are
advised to use *note multiprocessing: 98. or *note
concurrent.futures.ProcessPoolExecutor: 1d6.  However, threading is
still an appropriate model if you want to run multiple I/O-bound tasks
simultaneously.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Thread_(computing)


File: python.info,  Node: GIL and performance considerations,  Next: Reference<2>,  Prev: Introduction<7>,  Up: threading — Thread-based parallelism

5.18.1.2 GIL and performance considerations
...........................................

Unlike the *note multiprocessing: 98. module, which uses separate
processes to bypass the *note global interpreter lock: 474. (GIL), the
threading module operates within a single process, meaning that all
threads share the same memory space.  However, the GIL limits the
performance gains of threading when it comes to CPU-bound tasks, as only
one thread can execute Python bytecode at a time.  Despite this, threads
remain a useful tool for achieving concurrency in many scenarios.

As of Python 3.13, *note free-threaded: 1f4. builds can disable the GIL,
enabling true parallel execution of threads, but this feature is not
available by default (see PEP 703(1)).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0703/


File: python.info,  Node: Reference<2>,  Next: Using locks conditions and semaphores in the with statement,  Prev: GIL and performance considerations,  Up: threading — Thread-based parallelism

5.18.1.3 Reference
..................

This module defines the following functions:

 -- Funzione: threading.active_count ()

     Return the number of *note Thread: 176. objects currently alive.
     The returned count is equal to the length of the list returned by
     *note enumerate(): 1c42.

     The function ‘activeCount’ is a deprecated alias for this function.

 -- Funzione: threading.current_thread ()

     Return the current *note Thread: 176. object, corresponding to the
     caller’s thread of control.  If the caller’s thread of control was
     not created through the ‘threading’ module, a dummy thread object
     with limited functionality is returned.

     The function ‘currentThread’ is a deprecated alias for this
     function.

 -- Funzione: threading.excepthook (args, /)

     Handle uncaught exception raised by *note Thread.run(): c33.

     The 'args' argument has the following attributes:

        * 'exc_type': Exception type.

        * 'exc_value': Exception value, can be ‘None’.

        * 'exc_traceback': Exception traceback, can be ‘None’.

        * 'thread': Thread which raised the exception, can be ‘None’.

     If 'exc_type' is *note SystemExit: f3e, the exception is silently
     ignored.  Otherwise, the exception is printed out on *note
     sys.stderr: b35.

     If this function raises an exception, *note sys.excepthook(): a0e.
     is called to handle it.

     *note threading.excepthook(): a4d. can be overridden to control how
     uncaught exceptions raised by *note Thread.run(): c33. are handled.

     Storing 'exc_value' using a custom hook can create a reference
     cycle.  It should be cleared explicitly to break the reference
     cycle when the exception is no longer needed.

     Storing 'thread' using a custom hook can resurrect it if it is set
     to an object which is being finalized.  Avoid storing 'thread'
     after the custom hook completes to avoid resurrecting objects.

     Vedi anche
     ..........

     *note sys.excepthook(): a0e. handles uncaught exceptions.

     Added in version 3.8.

 -- Dati: threading.__excepthook__

     Holds the original value of *note threading.excepthook(): a4d.  It
     is saved so that the original value can be restored in case they
     happen to get replaced with broken or alternative objects.

     Added in version 3.10.

 -- Funzione: threading.get_ident ()

     Return the “thread identifier” of the current thread.  This is a
     nonzero integer.  Its value has no direct meaning; it is intended
     as a magic cookie to be used e.g.  to index a dictionary of
     thread-specific data.  Thread identifiers may be recycled when a
     thread exits and another thread is created.

     Added in version 3.3.

 -- Funzione: threading.get_native_id ()

     Return the native integral Thread ID of the current thread assigned
     by the kernel.  This is a non-negative integer.  Its value may be
     used to uniquely identify this particular thread system-wide (until
     the thread terminates, after which the value may be recycled by the
     OS).

     *note Availability: 2128.: Windows, FreeBSD, Linux, macOS, OpenBSD,
     NetBSD, AIX, DragonFlyBSD, GNU/kFreeBSD.

     Added in version 3.8.

     Cambiato nella versione 3.13: Added support for GNU/kFreeBSD.

 -- Funzione: threading.enumerate ()

     Return a list of all *note Thread: 176. objects currently active.
     The list includes daemonic threads and dummy thread objects created
     by *note current_thread(): 35e.  It excludes terminated threads and
     threads that have not yet been started.  However, the main thread
     is always part of the result, even when terminated.

 -- Funzione: threading.main_thread ()

     Return the main *note Thread: 176. object.  In normal conditions,
     the main thread is the thread from which the Python interpreter was
     started.

     Added in version 3.4.

 -- Funzione: threading.settrace (func)

     Set a trace function for all threads started from the ‘threading’
     module.  The 'func' will be passed to *note sys.settrace(): 2e1.
     for each thread, before its *note run(): c33. method is called.

 -- Funzione: threading.settrace_all_threads (func)

     Set a trace function for all threads started from the ‘threading’
     module and all Python threads that are currently executing.

     The 'func' will be passed to *note sys.settrace(): 2e1. for each
     thread, before its *note run(): c33. method is called.

     Added in version 3.12.

 -- Funzione: threading.gettrace ()

     Get the trace function as set by *note settrace(): a4a.

     Added in version 3.10.

 -- Funzione: threading.setprofile (func)

     Set a profile function for all threads started from the ‘threading’
     module.  The 'func' will be passed to *note sys.setprofile(): 1705.
     for each thread, before its *note run(): c33. method is called.

 -- Funzione: threading.setprofile_all_threads (func)

     Set a profile function for all threads started from the ‘threading’
     module and all Python threads that are currently executing.

     The 'func' will be passed to *note sys.setprofile(): 1705. for each
     thread, before its *note run(): c33. method is called.

     Added in version 3.12.

 -- Funzione: threading.getprofile ()

     Get the profiler function as set by *note setprofile(): a4b.

     Added in version 3.10.

 -- Funzione: threading.stack_size ([size])

     Return the thread stack size used when creating new threads.  The
     optional 'size' argument specifies the stack size to be used for
     subsequently created threads, and must be 0 (use platform or
     configured default) or a positive integer value of at least 32,768
     (32 KiB). If 'size' is not specified, 0 is used.  If changing the
     thread stack size is unsupported, a *note RuntimeError: 244. is
     raised.  If the specified stack size is invalid, a *note
     ValueError: 2ec. is raised and the stack size is unmodified.  32
     KiB is currently the minimum supported stack size value to
     guarantee sufficient stack space for the interpreter itself.  Note
     that some platforms may have particular restrictions on values for
     the stack size, such as requiring a minimum stack size > 32 KiB or
     requiring allocation in multiples of the system memory page size -
     platform documentation should be referred to for more information
     (4 KiB pages are common; using multiples of 4096 for the stack size
     is the suggested approach in the absence of more specific
     information).

     *note Availability: 2128.: Windows, pthreads.

     Unix platforms with POSIX threads support.

This module also defines the following constant:

 -- Dati: threading.TIMEOUT_MAX

     The maximum value allowed for the 'timeout' parameter of blocking
     functions (*note Lock.acquire(): 8a8, *note RLock.acquire(): 107d,
     *note Condition.wait(): 1c4e, etc.).  Specifying a timeout greater
     than this value will raise an *note OverflowError: a83.

     Added in version 3.2.

This module defines a number of classes, which are detailed in the
sections below.

The design of this module is loosely based on Java’s threading model.
However, where Java makes locks and condition variables basic behavior
of every object, they are separate objects in Python.  Python’s *note
Thread: 176. class supports a subset of the behavior of Java’s Thread
class; currently, there are no priorities, no thread groups, and threads
cannot be destroyed, stopped, suspended, resumed, or interrupted.  The
static methods of Java’s Thread class, when implemented, are mapped to
module-level functions.

All of the methods described below are executed atomically.

* Menu:

* Thread-local data::
* Thread objects::
* Lock objects::
* RLock objects::
* Condition objects::
* Semaphore objects::
* Semaphore example::
* Event objects::
* Timer objects::
* Barrier objects::


File: python.info,  Node: Thread-local data,  Next: Thread objects,  Up: Reference<2>

5.18.1.4 Thread-local data
..........................

Thread-local data is data whose values are thread specific.  If you have
data that you want to be local to a thread, create a *note local: 1847.
object and use its attributes:

     >>> mydata = local()
     >>> mydata.number = 42
     >>> mydata.number
     42

You can also access the *note local: 1847.-object’s dictionary:

     >>> mydata.__dict__
     {'number': 42}
     >>> mydata.__dict__.setdefault('widgets', [])
     []
     >>> mydata.widgets
     []

If we access the data in a different thread:

     >>> log = []
     >>> def f():
     ...     items = sorted(mydata.__dict__.items())
     ...     log.append(items)
     ...     mydata.number = 11
     ...     log.append(mydata.number)

     >>> import threading
     >>> thread = threading.Thread(target=f)
     >>> thread.start()
     >>> thread.join()
     >>> log
     [[], 11]

we get different data.  Furthermore, changes made in the other thread
don’t affect data seen in this thread:

     >>> mydata.number
     42

Of course, values you get from a *note local: 1847. object, including
their *note __dict__: 77e. attribute, are for whatever thread was
current at the time the attribute was read.  For that reason, you
generally don’t want to save these values across threads, as they apply
only to the thread they came from.

You can create custom *note local: 1847. objects by subclassing the
*note local: 1847. class:

     >>> class MyLocal(local):
     ...     number = 2
     ...     def __init__(self, /, **kw):
     ...         self.__dict__.update(kw)
     ...     def squared(self):
     ...         return self.number ** 2

This can be useful to support default values, methods and
initialization.  Note that if you define an *note __init__(): 8c0.
method, it will be called each time the *note local: 1847. object is
used in a separate thread.  This is necessary to initialize each
thread’s dictionary.

Now if we create a *note local: 1847. object:

     >>> mydata = MyLocal(color='red')

we have a default number:

     >>> mydata.number
     2

an initial color:

     >>> mydata.color
     'red'
     >>> del mydata.color

And a method that operates on the data:

     >>> mydata.squared()
     4

As before, we can access the data in a separate thread:

     >>> log = []
     >>> thread = threading.Thread(target=f)
     >>> thread.start()
     >>> thread.join()
     >>> log
     [[('color', 'red')], 11]

without affecting this thread’s data:

     >>> mydata.number
     2
     >>> mydata.color
     Traceback (most recent call last):
     ...
     AttributeError: 'MyLocal' object has no attribute 'color'

Note that subclasses can define *note __slots__: 7f8, but they are not
thread local.  They are shared across threads:

     >>> class MyLocal(local):
     ...     __slots__ = 'number'

     >>> mydata = MyLocal()
     >>> mydata.number = 42
     >>> mydata.color = 'red'

So, the separate thread:

     >>> thread = threading.Thread(target=f)
     >>> thread.start()
     >>> thread.join()

affects what we see:

     >>> mydata.number
     11

 -- Classe: threading.local

     A class that represents thread-local data.


File: python.info,  Node: Thread objects,  Next: Lock objects,  Prev: Thread-local data,  Up: Reference<2>

5.18.1.5 Thread objects
.......................

The *note Thread: 176. class represents an activity that is run in a
separate thread of control.  There are two ways to specify the activity:
by passing a callable object to the constructor, or by overriding the
*note run(): c33. method in a subclass.  No other methods (except for
the constructor) should be overridden in a subclass.  In other words,
'only' override the ‘__init__()’ and *note run(): c33. methods of this
class.

Once a thread object is created, its activity must be started by calling
the thread’s *note start(): 178. method.  This invokes the *note run():
c33. method in a separate thread of control.

Once the thread’s activity is started, the thread is considered “alive”.
It stops being alive when its *note run(): c33. method terminates –
either normally, or by raising an unhandled exception.  The *note
is_alive(): b48. method tests whether the thread is alive.

Other threads can call a thread’s *note join(): 13ec. method.  This
blocks the calling thread until the thread whose *note join(): 13ec.
method is called is terminated.

A thread has a name.  The name can be passed to the constructor, and
read or changed through the *note name: 2a0. attribute.

If the *note run(): c33. method raises an exception, *note
threading.excepthook(): a4d. is called to handle it.  By default, *note
threading.excepthook(): a4d. ignores silently *note SystemExit: f3e.

A thread can be flagged as a «daemon thread».  The significance of this
flag is that the entire Python program exits when only daemon threads
are left.  The initial value is inherited from the creating thread.  The
flag can be set through the *note daemon: 35c. property or the 'daemon'
constructor argument.

     Nota: Daemon threads are abruptly stopped at shutdown.  Their
     resources (such as open files, database transactions, etc.)  may
     not be released properly.  If you want your threads to stop
     gracefully, make them non-daemonic and use a suitable signalling
     mechanism such as an *note Event: 1360.

There is a «main thread» object; this corresponds to the initial thread
of control in the Python program.  It is not a daemon thread.

There is the possibility that «dummy thread objects» are created.  These
are thread objects corresponding to «alien threads», which are threads
of control started outside the threading module, such as directly from C
code.  Dummy thread objects have limited functionality; they are always
considered alive and daemonic, and cannot be *note joined: 3604.  They
are never deleted, since it is impossible to detect the termination of
alien threads.

 -- Classe: threading.Thread (group=None, target=None, name=None,
          args=(), kwargs={}, *, daemon=None, context=None)

     This constructor should always be called with keyword arguments.
     Arguments are:

     'group' should be ‘None’; reserved for future extension when a
     ‘ThreadGroup’ class is implemented.

     'target' is the callable object to be invoked by the *note run():
     c33. method.  Defaults to ‘None’, meaning nothing is called.

     'name' is the thread name.  By default, a unique name is
     constructed of the form «Thread-'N'» where 'N' is a small decimal
     number, or «Thread-'N' (target)» where «target» is
     ‘target.__name__’ if the 'target' argument is specified.

     'args' is a list or tuple of arguments for the target invocation.
     Defaults to ‘()’.

     'kwargs' is a dictionary of keyword arguments for the target
     invocation.  Defaults to ‘{}’.

     If not ‘None’, 'daemon' explicitly sets whether the thread is
     daemonic.  If ‘None’ (the default), the daemonic property is
     inherited from the current thread.

     'context' is the *note Context: 177. value to use when starting the
     thread.  The default value is ‘None’ which indicates that the *note
     sys.flags.thread_inherit_context: 175. flag controls the behaviour.
     If the flag is true, threads will start with a copy of the context
     of the caller of *note start(): 178.  If false, they will start
     with an empty context.  To explicitly start with an empty context,
     pass a new instance of *note Context(): 177.  To explicitly start
     with a copy of the current context, pass the value from *note
     copy_context(): 3605.  The flag defaults true on free-threaded
     builds and false otherwise.

     If the subclass overrides the constructor, it must make sure to
     invoke the base class constructor (‘Thread.__init__()’) before
     doing anything else to the thread.

     Cambiato nella versione 3.3: Added the 'daemon' parameter.

     Cambiato nella versione 3.10: Use the 'target' name if 'name'
     argument is omitted.

     Cambiato nella versione 3.14: Added the 'context' parameter.

      -- Metodo: start ()

          Start the thread’s activity.

          It must be called at most once per thread object.  It arranges
          for the object’s *note run(): c33. method to be invoked in a
          separate thread of control.

          This method will raise a *note RuntimeError: 244. if called
          more than once on the same thread object.

          If supported, set the operating system thread name to *note
          threading.Thread.name: 2a0.  The name can be truncated
          depending on the operating system thread name limits.

          Cambiato nella versione 3.14: Set the operating system thread
          name.

      -- Metodo: run ()

          Method representing the thread’s activity.

          You may override this method in a subclass.  The standard
          *note run(): c33. method invokes the callable object passed to
          the object’s constructor as the 'target' argument, if any,
          with positional and keyword arguments taken from the 'args'
          and 'kwargs' arguments, respectively.

          Using list or tuple as the 'args' argument which passed to the
          *note Thread: 176. could achieve the same effect.

          Example:

               >>> from threading import Thread
               >>> t = Thread(target=print, args=[1])
               >>> t.run()
               1
               >>> t = Thread(target=print, args=(1,))
               >>> t.run()
               1

      -- Metodo: join (timeout=None)

          Wait until the thread terminates.  This blocks the calling
          thread until the thread whose *note join(): 13ec. method is
          called terminates – either normally or through an unhandled
          exception – or until the optional timeout occurs.

          When the 'timeout' argument is present and not ‘None’, it
          should be a floating-point number specifying a timeout for the
          operation in seconds (or fractions thereof).  As *note join():
          13ec. always returns ‘None’, you must call *note is_alive():
          b48. after *note join(): 13ec. to decide whether a timeout
          happened – if the thread is still alive, the *note join():
          13ec. call timed out.

          When the 'timeout' argument is not present or ‘None’, the
          operation will block until the thread terminates.

          A thread can be joined many times.

          *note join(): 13ec. raises a *note RuntimeError: 244. if an
          attempt is made to join the current thread as that would cause
          a deadlock.  It is also an error to *note join(): 13ec. a
          thread before it has been started and attempts to do so raise
          the same exception.

          If an attempt is made to join a running daemonic thread in
          late stages of *note Python finalization: 47a. ‘join()’ raises
          a *note PythonFinalizationError: 479.

          Cambiato nella versione 3.14: May raise *note
          PythonFinalizationError: 479.

      -- Attributo: name

          A string used for identification purposes only.  It has no
          semantics.  Multiple threads may be given the same name.  The
          initial name is set by the constructor.

          On some platforms, the thread name is set at the operating
          system level when the thread starts, so that it is visible in
          task managers.  This name may be truncated to fit in a
          system-specific limit (for example, 15 bytes on Linux or 63
          bytes on macOS).

          Changes to 'name' are only reflected at the OS level when the
          currently running thread is renamed.  (Setting the 'name'
          attribute of a different thread only updates the Python Thread
          object.)

      -- Metodo: getName ()
      -- Metodo: setName ()

          Deprecated getter/setter API for *note name: 2a0.; use it
          directly as a property instead.

          Deprecato dalla versione 3.10.

      -- Attributo: ident

          The “thread identifier” of this thread or ‘None’ if the thread
          has not been started.  This is a nonzero integer.  See the
          *note get_ident(): 1362. function.  Thread identifiers may be
          recycled when a thread exits and another thread is created.
          The identifier is available even after the thread has exited.

      -- Attributo: native_id

          The Thread ID (‘TID’) of this thread, as assigned by the OS
          (kernel).  This is a non-negative integer, or ‘None’ if the
          thread has not been started.  See the *note get_native_id():
          c34. function.  This value may be used to uniquely identify
          this particular thread system-wide (until the thread
          terminates, after which the value may be recycled by the OS).

               Nota: Similar to Process IDs, Thread IDs are only valid
               (guaranteed unique system-wide) from the time the thread
               is created until the thread has been terminated.

          *note Availability: 2128.: Windows, FreeBSD, Linux, macOS,
          OpenBSD, NetBSD, AIX, DragonFlyBSD.

          Added in version 3.8.

      -- Metodo: is_alive ()

          Return whether the thread is alive.

          This method returns ‘True’ just before the *note run(): c33.
          method starts until just after the *note run(): c33. method
          terminates.  The module function *note enumerate(): 1c42.
          returns a list of all alive threads.

      -- Attributo: daemon

          A boolean value indicating whether this thread is a daemon
          thread (‘True’) or not (‘False’).  This must be set before
          *note start(): 178. is called, otherwise *note RuntimeError:
          244. is raised.  Its initial value is inherited from the
          creating thread; the main thread is not a daemon thread and
          therefore all threads created in the main thread default to
          *note daemon: 35c. = ‘False’.

          The entire Python program exits when no alive non-daemon
          threads are left.

      -- Metodo: isDaemon ()
      -- Metodo: setDaemon ()

          Deprecated getter/setter API for *note daemon: 35c.; use it
          directly as a property instead.

          Deprecato dalla versione 3.10.


File: python.info,  Node: Lock objects,  Next: RLock objects,  Prev: Thread objects,  Up: Reference<2>

5.18.1.6 Lock objects
.....................

A primitive lock is a synchronization primitive that is not owned by a
particular thread when locked.  In Python, it is currently the lowest
level synchronization primitive available, implemented directly by the
*note _thread: 2. extension module.

A primitive lock is in one of two states, «locked» or «unlocked».  It is
created in the unlocked state.  It has two basic methods, *note
acquire(): 8a8. and *note release(): 14ca.  When the state is unlocked,
*note acquire(): 8a8. changes the state to locked and returns
immediately.  When the state is locked, *note acquire(): 8a8. blocks
until a call to *note release(): 14ca. in another thread changes it to
unlocked, then the *note acquire(): 8a8. call resets it to locked and
returns.  The *note release(): 14ca. method should only be called in the
locked state; it changes the state to unlocked and returns immediately.
If an attempt is made to release an unlocked lock, a *note RuntimeError:
244. will be raised.

Locks also support the *note context management protocol: 360a.

When more than one thread is blocked in *note acquire(): 8a8. waiting
for the state to turn to unlocked, only one thread proceeds when a *note
release(): 14ca. call resets the state to unlocked; which one of the
waiting threads proceeds is not defined, and may vary across
implementations.

All methods are executed atomically.

 -- Classe: threading.Lock

     The class implementing primitive lock objects.  Once a thread has
     acquired a lock, subsequent attempts to acquire it block, until it
     is released; any thread may release it.

     Cambiato nella versione 3.13: ‘Lock’ is now a class.  In earlier
     Pythons, ‘Lock’ was a factory function which returned an instance
     of the underlying private lock type.

      -- Metodo: acquire (blocking=True, timeout=-1)

          Acquire a lock, blocking or non-blocking.

          When invoked with the 'blocking' argument set to ‘True’ (the
          default), block until the lock is unlocked, then set it to
          locked and return ‘True’.

          When invoked with the 'blocking' argument set to ‘False’, do
          not block.  If a call with 'blocking' set to ‘True’ would
          block, return ‘False’ immediately; otherwise, set the lock to
          locked and return ‘True’.

          When invoked with the floating-point 'timeout' argument set to
          a positive value, block for at most the number of seconds
          specified by 'timeout' and as long as the lock cannot be
          acquired.  A 'timeout' argument of ‘-1’ specifies an unbounded
          wait.  It is forbidden to specify a 'timeout' when 'blocking'
          is ‘False’.

          The return value is ‘True’ if the lock is acquired
          successfully, ‘False’ if not (for example if the 'timeout'
          expired).

          Cambiato nella versione 3.2: The 'timeout' parameter is new.

          Cambiato nella versione 3.2: Lock acquisition can now be
          interrupted by signals on POSIX if the underlying threading
          implementation supports it.

          Cambiato nella versione 3.14: Lock acquisition can now be
          interrupted by signals on Windows.

      -- Metodo: release ()

          Release a lock.  This can be called from any thread, not only
          the thread which has acquired the lock.

          When the lock is locked, reset it to unlocked, and return.  If
          any other threads are blocked waiting for the lock to become
          unlocked, allow exactly one of them to proceed.

          When invoked on an unlocked lock, a *note RuntimeError: 244.
          is raised.

          There is no return value.

      -- Metodo: locked ()

          Return ‘True’ if the lock is acquired.


File: python.info,  Node: RLock objects,  Next: Condition objects,  Prev: Lock objects,  Up: Reference<2>

5.18.1.7 RLock objects
......................

A reentrant lock is a synchronization primitive that may be acquired
multiple times by the same thread.  Internally, it uses the concepts of
«owning thread» and «recursion level» in addition to the locked/unlocked
state used by primitive locks.  In the locked state, some thread owns
the lock; in the unlocked state, no thread owns it.

Threads call a lock’s *note acquire(): 107d. method to lock it, and its
*note release(): 14ca. method to unlock it.

     Nota: Reentrant locks support the *note context management
     protocol: 360a, so it is recommended to use *note with: 186.
     instead of manually calling *note acquire(): 107d. and *note
     release(): 360e. to handle acquiring and releasing the lock for a
     block of code.

RLock’s *note acquire(): 107d./*note release(): 360e. call pairs may be
nested, unlike Lock’s *note acquire(): 8a8./*note release(): 14ca.  Only
the final *note release(): 360e. (the *note release(): 14ca. of the
outermost pair) resets the lock to an unlocked state and allows another
thread blocked in *note acquire(): 107d. to proceed.

*note acquire(): 107d./*note release(): 360e. must be used in pairs:
each acquire must have a release in the thread that has acquired the
lock.  Failing to call release as many times the lock has been acquired
can lead to deadlock.

 -- Classe: threading.RLock

     This class implements reentrant lock objects.  A reentrant lock
     must be released by the thread that acquired it.  Once a thread has
     acquired a reentrant lock, the same thread may acquire it again
     without blocking; the thread must release it once for each time it
     has acquired it.

     Note that ‘RLock’ is actually a factory function which returns an
     instance of the most efficient version of the concrete RLock class
     that is supported by the platform.

      -- Metodo: acquire (blocking=True, timeout=-1)

          Acquire a lock, blocking or non-blocking.

          Vedi anche
          ..........

          *note Using RLock as a context manager: 360a.

               Recommended over manual ‘acquire()’ and *note release():
               360e. calls whenever practical.

          When invoked with the 'blocking' argument set to ‘True’ (the
          default):

                  * If no thread owns the lock, acquire the lock and
                    return immediately.

                  * If another thread owns the lock, block until we are
                    able to acquire lock, or 'timeout', if set to a
                    positive float value.

                  * If the same thread owns the lock, acquire the lock
                    again, and return immediately.  This is the
                    difference between *note Lock: 19dc. and ‘RLock’;
                    *note Lock: 19dc. handles this case the same as the
                    previous, blocking until the lock can be acquired.

          When invoked with the 'blocking' argument set to ‘False’:

                  * If no thread owns the lock, acquire the lock and
                    return immediately.

                  * If another thread owns the lock, return immediately.

                  * If the same thread owns the lock, acquire the lock
                    again and return immediately.

          In all cases, if the thread was able to acquire the lock,
          return ‘True’.  If the thread was unable to acquire the lock
          (i.e.  if not blocking or the timeout was reached) return
          ‘False’.

          If called multiple times, failing to call *note release():
          360e. as many times may lead to deadlock.  Consider using
          ‘RLock’ as a context manager rather than calling
          acquire/release directly.

          Cambiato nella versione 3.2: The 'timeout' parameter is new.

      -- Metodo: release ()

          Release a lock, decrementing the recursion level.  If after
          the decrement it is zero, reset the lock to unlocked (not
          owned by any thread), and if any other threads are blocked
          waiting for the lock to become unlocked, allow exactly one of
          them to proceed.  If after the decrement the recursion level
          is still nonzero, the lock remains locked and owned by the
          calling thread.

          Only call this method when the calling thread owns the lock.
          A *note RuntimeError: 244. is raised if this method is called
          when the lock is not acquired.

          There is no return value.

      -- Metodo: locked ()

          Return a boolean indicating whether this object is locked
          right now.

          Added in version 3.14.


File: python.info,  Node: Condition objects,  Next: Semaphore objects,  Prev: RLock objects,  Up: Reference<2>

5.18.1.8 Condition objects
..........................

A condition variable is always associated with some kind of lock; this
can be passed in or one will be created by default.  Passing one in is
useful when several condition variables must share the same lock.  The
lock is part of the condition object: you don’t have to track it
separately.

A condition variable obeys the *note context management protocol: 360a.:
using the ‘with’ statement acquires the associated lock for the duration
of the enclosed block.  The *note acquire(): 3611. and *note release():
3612. methods also call the corresponding methods of the associated
lock.

Other methods must be called with the associated lock held.  The *note
wait(): 1c4e. method releases the lock, and then blocks until another
thread awakens it by calling *note notify(): 1b4e. or *note
notify_all(): 359.  Once awakened, *note wait(): 1c4e. re-acquires the
lock and returns.  It is also possible to specify a timeout.

The *note notify(): 1b4e. method wakes up one of the threads waiting for
the condition variable, if any are waiting.  The *note notify_all():
359. method wakes up all threads waiting for the condition variable.

Note: the *note notify(): 1b4e. and *note notify_all(): 359. methods
don’t release the lock; this means that the thread or threads awakened
will not return from their *note wait(): 1c4e. call immediately, but
only when the thread that called *note notify(): 1b4e. or *note
notify_all(): 359. finally relinquishes ownership of the lock.

The typical programming style using condition variables uses the lock to
synchronize access to some shared state; threads that are interested in
a particular change of state call *note wait(): 1c4e. repeatedly until
they see the desired state, while threads that modify the state call
*note notify(): 1b4e. or *note notify_all(): 359. when they change the
state in such a way that it could possibly be a desired state for one of
the waiters.  For example, the following code is a generic
producer-consumer situation with unlimited buffer capacity:

     # Consume one item
     with cv:
         while not an_item_is_available():
             cv.wait()
         get_an_available_item()

     # Produce one item
     with cv:
         make_an_item_available()
         cv.notify()

The ‘while’ loop checking for the application’s condition is necessary
because *note wait(): 1c4e. can return after an arbitrary long time, and
the condition which prompted the *note notify(): 1b4e. call may no
longer hold true.  This is inherent to multi-threaded programming.  The
*note wait_for(): 3613. method can be used to automate the condition
checking, and eases the computation of timeouts:

     # Consume an item
     with cv:
         cv.wait_for(an_item_is_available)
         get_an_available_item()

To choose between *note notify(): 1b4e. and *note notify_all(): 359,
consider whether one state change can be interesting for only one or
several waiting threads.  E.g.  in a typical producer-consumer
situation, adding one item to the buffer only needs to wake up one
consumer thread.

 -- Classe: threading.Condition (lock=None)

     This class implements condition variable objects.  A condition
     variable allows one or more threads to wait until they are notified
     by another thread.

     If the 'lock' argument is given and not ‘None’, it must be a *note
     Lock: 19dc. or *note RLock: 32e. object, and it is used as the
     underlying lock.  Otherwise, a new *note RLock: 32e. object is
     created and used as the underlying lock.

     Cambiato nella versione 3.3: changed from a factory function to a
     class.

      -- Metodo: acquire (*args)

          Acquire the underlying lock.  This method calls the
          corresponding method on the underlying lock; the return value
          is whatever that method returns.

      -- Metodo: release ()

          Release the underlying lock.  This method calls the
          corresponding method on the underlying lock; there is no
          return value.

      -- Metodo: locked ()

          Return a boolean indicating whether this object is locked
          right now.

          Added in version 3.14.

      -- Metodo: wait (timeout=None)

          Wait until notified or until a timeout occurs.  If the calling
          thread has not acquired the lock when this method is called, a
          *note RuntimeError: 244. is raised.

          This method releases the underlying lock, and then blocks
          until it is awakened by a *note notify(): 1b4e. or *note
          notify_all(): 359. call for the same condition variable in
          another thread, or until the optional timeout occurs.  Once
          awakened or timed out, it re-acquires the lock and returns.

          When the 'timeout' argument is present and not ‘None’, it
          should be a floating-point number specifying a timeout for the
          operation in seconds (or fractions thereof).

          When the underlying lock is an *note RLock: 32e, it is not
          released using its *note release(): 3612. method, since this
          may not actually unlock the lock when it was acquired multiple
          times recursively.  Instead, an internal interface of the
          *note RLock: 32e. class is used, which really unlocks it even
          when it has been recursively acquired several times.  Another
          internal interface is then used to restore the recursion level
          when the lock is reacquired.

          The return value is ‘True’ unless a given 'timeout' expired,
          in which case it is ‘False’.

          Cambiato nella versione 3.2: Previously, the method always
          returned ‘None’.

      -- Metodo: wait_for (predicate, timeout=None)

          Wait until a condition evaluates to true.  'predicate' should
          be a callable which result will be interpreted as a boolean
          value.  A 'timeout' may be provided giving the maximum time to
          wait.

          This utility method may call *note wait(): 1c4e. repeatedly
          until the predicate is satisfied, or until a timeout occurs.
          The return value is the last return value of the predicate and
          will evaluate to ‘False’ if the method timed out.

          Ignoring the timeout feature, calling this method is roughly
          equivalent to writing:

               while not predicate():
                   cv.wait()

          Therefore, the same rules apply as with *note wait(): 1c4e.:
          The lock must be held when called and is re-acquired on
          return.  The predicate is evaluated with the lock held.

          Added in version 3.2.

      -- Metodo: notify (n=1)

          By default, wake up one thread waiting on this condition, if
          any.  If the calling thread has not acquired the lock when
          this method is called, a *note RuntimeError: 244. is raised.

          This method wakes up at most 'n' of the threads waiting for
          the condition variable; it is a no-op if no threads are
          waiting.

          The current implementation wakes up exactly 'n' threads, if at
          least 'n' threads are waiting.  However, it’s not safe to rely
          on this behavior.  A future, optimized implementation may
          occasionally wake up more than 'n' threads.

          Note: an awakened thread does not actually return from its
          *note wait(): 1c4e. call until it can reacquire the lock.
          Since *note notify(): 1b4e. does not release the lock, its
          caller should.

      -- Metodo: notify_all ()

          Wake up all threads waiting on this condition.  This method
          acts like *note notify(): 1b4e, but wakes up all waiting
          threads instead of one.  If the calling thread has not
          acquired the lock when this method is called, a *note
          RuntimeError: 244. is raised.

          The method ‘notifyAll’ is a deprecated alias for this method.


File: python.info,  Node: Semaphore objects,  Next: Semaphore example,  Prev: Condition objects,  Up: Reference<2>

5.18.1.9 Semaphore objects
..........................

This is one of the oldest synchronization primitives in the history of
computer science, invented by the early Dutch computer scientist Edsger
W. Dijkstra (he used the names ‘P()’ and ‘V()’ instead of *note
acquire(): 145b. and *note release(): 3617.).

A semaphore manages an internal counter which is decremented by each
*note acquire(): 145b. call and incremented by each *note release():
3617. call.  The counter can never go below zero; when *note acquire():
145b. finds that it is zero, it blocks, waiting until some other thread
calls *note release(): 3617.

Semaphores also support the *note context management protocol: 360a.

 -- Classe: threading.Semaphore (value=1)

     This class implements semaphore objects.  A semaphore manages an
     atomic counter representing the number of *note release(): 3617.
     calls minus the number of *note acquire(): 145b. calls, plus an
     initial value.  The *note acquire(): 145b. method blocks if
     necessary until it can return without making the counter negative.
     If not given, 'value' defaults to 1.

     The optional argument gives the initial 'value' for the internal
     counter; it defaults to ‘1’.  If the 'value' given is less than 0,
     *note ValueError: 2ec. is raised.

     Cambiato nella versione 3.3: changed from a factory function to a
     class.

      -- Metodo: acquire (blocking=True, timeout=None)

          Acquire a semaphore.

          When invoked without arguments:

             * If the internal counter is larger than zero on entry,
               decrement it by one and return ‘True’ immediately.

             * If the internal counter is zero on entry, block until
               awoken by a call to *note release(): 3617.  Once awoken
               (and the counter is greater than 0), decrement the
               counter by 1 and return ‘True’.  Exactly one thread will
               be awoken by each call to *note release(): 3617.  The
               order in which threads are awoken should not be relied
               on.

          When invoked with 'blocking' set to ‘False’, do not block.  If
          a call without an argument would block, return ‘False’
          immediately; otherwise, do the same thing as when called
          without arguments, and return ‘True’.

          When invoked with a 'timeout' other than ‘None’, it will block
          for at most 'timeout' seconds.  If acquire does not complete
          successfully in that interval, return ‘False’.  Return ‘True’
          otherwise.

          Cambiato nella versione 3.2: The 'timeout' parameter is new.

      -- Metodo: release (n=1)

          Release a semaphore, incrementing the internal counter by 'n'.
          When it was zero on entry and other threads are waiting for it
          to become larger than zero again, wake up 'n' of those
          threads.

          Cambiato nella versione 3.9: Added the 'n' parameter to
          release multiple waiting threads at once.

 -- Classe: threading.BoundedSemaphore (value=1)

     Class implementing bounded semaphore objects.  A bounded semaphore
     checks to make sure its current value doesn’t exceed its initial
     value.  If it does, *note ValueError: 2ec. is raised.  In most
     situations semaphores are used to guard resources with limited
     capacity.  If the semaphore is released too many times it’s a sign
     of a bug.  If not given, 'value' defaults to 1.

     Cambiato nella versione 3.3: changed from a factory function to a
     class.


File: python.info,  Node: Semaphore example,  Next: Event objects,  Prev: Semaphore objects,  Up: Reference<2>

5.18.1.10 ‘Semaphore’ example
.............................

Semaphores are often used to guard resources with limited capacity, for
example, a database server.  In any situation where the size of the
resource is fixed, you should use a bounded semaphore.  Before spawning
any worker threads, your main thread would initialize the semaphore:

     maxconnections = 5
     # ...
     pool_sema = BoundedSemaphore(value=maxconnections)

Once spawned, worker threads call the semaphore’s acquire and release
methods when they need to connect to the server:

     with pool_sema:
         conn = connectdb()
         try:
             # ... use connection ...
         finally:
             conn.close()

The use of a bounded semaphore reduces the chance that a programming
error which causes the semaphore to be released more than it’s acquired
will go undetected.


File: python.info,  Node: Event objects,  Next: Timer objects,  Prev: Semaphore example,  Up: Reference<2>

5.18.1.11 Event objects
.......................

This is one of the simplest mechanisms for communication between
threads: one thread signals an event and other threads wait for it.

An event object manages an internal flag that can be set to true with
the *note set(): 361c. method and reset to false with the *note clear():
361d. method.  The *note wait(): 152e. method blocks until the flag is
true.

 -- Classe: threading.Event

     Class implementing event objects.  An event manages a flag that can
     be set to true with the *note set(): 361c. method and reset to
     false with the *note clear(): 361d. method.  The *note wait():
     152e. method blocks until the flag is true.  The flag is initially
     false.

     Cambiato nella versione 3.3: changed from a factory function to a
     class.

      -- Metodo: is_set ()

          Return ‘True’ if and only if the internal flag is true.

          The method ‘isSet’ is a deprecated alias for this method.

      -- Metodo: set ()

          Set the internal flag to true.  All threads waiting for it to
          become true are awakened.  Threads that call *note wait():
          152e. once the flag is true will not block at all.

      -- Metodo: clear ()

          Reset the internal flag to false.  Subsequently, threads
          calling *note wait(): 152e. will block until *note set():
          361c. is called to set the internal flag to true again.

      -- Metodo: wait (timeout=None)

          Block as long as the internal flag is false and the timeout,
          if given, has not expired.  The return value represents the
          reason that this blocking method returned; ‘True’ if returning
          because the internal flag is set to true, or ‘False’ if a
          timeout is given and the internal flag did not become true
          within the given wait time.

          When the timeout argument is present and not ‘None’, it should
          be a floating-point number specifying a timeout for the
          operation in seconds, or fractions thereof.

          Cambiato nella versione 3.1: Previously, the method always
          returned ‘None’.


File: python.info,  Node: Timer objects,  Next: Barrier objects,  Prev: Event objects,  Up: Reference<2>

5.18.1.12 Timer objects
.......................

This class represents an action that should be run only after a certain
amount of time has passed — a timer.  *note Timer: 1361. is a subclass
of *note Thread: 176. and as such also functions as an example of
creating custom threads.

Timers are started, as with threads, by calling their *note Timer.start:
178. method.  The timer can be stopped (before its action has begun) by
calling the *note cancel(): 3620. method.  The interval the timer will
wait before executing its action may not be exactly the same as the
interval specified by the user.

For example:

     def hello():
         print("hello, world")

     t = Timer(30.0, hello)
     t.start()  # after 30 seconds, "hello, world" will be printed

 -- Classe: threading.Timer (interval, function, args=None, kwargs=None)

     Create a timer that will run 'function' with arguments 'args' and
     keyword arguments 'kwargs', after 'interval' seconds have passed.
     If 'args' is ‘None’ (the default) then an empty list will be used.
     If 'kwargs' is ‘None’ (the default) then an empty dict will be
     used.

     Cambiato nella versione 3.3: changed from a factory function to a
     class.

      -- Metodo: cancel ()

          Stop the timer, and cancel the execution of the timer’s
          action.  This will only work if the timer is still in its
          waiting stage.


File: python.info,  Node: Barrier objects,  Prev: Timer objects,  Up: Reference<2>

5.18.1.13 Barrier objects
.........................

Added in version 3.2.

This class provides a simple synchronization primitive for use by a
fixed number of threads that need to wait for each other.  Each of the
threads tries to pass the barrier by calling the *note wait(): 3622.
method and will block until all of the threads have made their *note
wait(): 3622. calls.  At this point, the threads are released
simultaneously.

The barrier can be reused any number of times for the same number of
threads.

As an example, here is a simple way to synchronize a client and server
thread:

     b = Barrier(2, timeout=5)

     def server():
         start_server()
         b.wait()
         while True:
             connection = accept_connection()
             process_server_connection(connection)

     def client():
         b.wait()
         while True:
             connection = make_connection()
             process_client_connection(connection)

 -- Classe: threading.Barrier (parties, action=None, timeout=None)

     Create a barrier object for 'parties' number of threads.  An
     'action', when provided, is a callable to be called by one of the
     threads when they are released.  'timeout' is the default timeout
     value if none is specified for the *note wait(): 3622. method.

      -- Metodo: wait (timeout=None)

          Pass the barrier.  When all the threads party to the barrier
          have called this function, they are all released
          simultaneously.  If a 'timeout' is provided, it is used in
          preference to any that was supplied to the class constructor.

          The return value is an integer in the range 0 to 'parties' –
          1, different for each thread.  This can be used to select a
          thread to do some special housekeeping, e.g.:

               i = barrier.wait()
               if i == 0:
                   # Only one thread needs to print this
                   print("passed the barrier")

          If an 'action' was provided to the constructor, one of the
          threads will have called it prior to being released.  Should
          this call raise an error, the barrier is put into the broken
          state.

          If the call times out, the barrier is put into the broken
          state.

          This method may raise a *note BrokenBarrierError: 13ed.
          exception if the barrier is broken or reset while a thread is
          waiting.

      -- Metodo: reset ()

          Return the barrier to the default, empty state.  Any threads
          waiting on it will receive the *note BrokenBarrierError: 13ed.
          exception.

          Note that using this function may require some external
          synchronization if there are other threads whose state is
          unknown.  If a barrier is broken it may be better to just
          leave it and create a new one.

      -- Metodo: abort ()

          Put the barrier into a broken state.  This causes any active
          or future calls to *note wait(): 3622. to fail with the *note
          BrokenBarrierError: 13ed.  Use this for example if one of the
          threads needs to abort, to avoid deadlocking the application.

          It may be preferable to simply create the barrier with a
          sensible 'timeout' value to automatically guard against one of
          the threads going awry.

      -- Attributo: parties

          The number of threads required to pass the barrier.

      -- Attributo: n_waiting

          The number of threads currently waiting in the barrier.

      -- Attributo: broken

          A boolean that is ‘True’ if the barrier is in the broken
          state.

 -- Eccezione: threading.BrokenBarrierError

     This exception, a subclass of *note RuntimeError: 244, is raised
     when the *note Barrier: 13eb. object is reset or broken.


File: python.info,  Node: Using locks conditions and semaphores in the with statement,  Prev: Reference<2>,  Up: threading — Thread-based parallelism

5.18.1.14 Using locks, conditions, and semaphores in the ‘with’ statement
.........................................................................

All of the objects provided by this module that have ‘acquire’ and
‘release’ methods can be used as context managers for a *note with: 186.
statement.  The ‘acquire’ method will be called when the block is
entered, and ‘release’ will be called when the block is exited.  Hence,
the following snippet:

     with some_lock:
         # do something...

is equivalent to:

     some_lock.acquire()
     try:
         # do something...
     finally:
         some_lock.release()

Currently, *note Lock: 19dc, *note RLock: 32e, *note Condition: 135d,
*note Semaphore: 135e, and *note BoundedSemaphore: 135f. objects may be
used as *note with: 186. statement context managers.


File: python.info,  Node: multiprocessing — Process-based parallelism,  Next: multiprocessing shared_memory — Shared memory for direct access across processes,  Prev: threading — Thread-based parallelism,  Up: Concurrent Execution

5.18.2 ‘multiprocessing’ — Process-based parallelism
----------------------------------------------------

'Source code:' Lib/multiprocessing/(1)

__________________________________________________________________

*note Availability: 2128.: not Android, not iOS, not WASI.

This module is not supported on *note mobile platforms: 2245. or *note
WebAssembly platforms: 1b52.

* Menu:

* Introduction: Introduction<8>.
* Reference: Reference<3>.
* Programming guidelines::
* Examples: Examples<15>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/multiprocessing/


File: python.info,  Node: Introduction<8>,  Next: Reference<3>,  Up: multiprocessing — Process-based parallelism

5.18.2.1 Introduction
.....................

*note multiprocessing: 98. is a package that supports spawning processes
using an API similar to the *note threading: f3. module.  The *note
multiprocessing: 98. package offers both local and remote concurrency,
effectively side-stepping the *note Global Interpreter Lock: 474. by
using subprocesses instead of threads.  Due to this, the *note
multiprocessing: 98. module allows the programmer to fully leverage
multiple processors on a given machine.  It runs on both POSIX and
Windows.

The *note multiprocessing: 98. module also introduces the *note Pool:
116d. object which offers a convenient means of parallelizing the
execution of a function across multiple input values, distributing the
input data across processes (data parallelism).  The following example
demonstrates the common practice of defining such functions in a module
so that child processes can successfully import that module.  This basic
example of data parallelism using *note Pool: 116d,

     from multiprocessing import Pool

     def f(x):
         return x*x

     if __name__ == '__main__':
         with Pool(5) as p:
             print(p.map(f, [1, 2, 3]))

will print to standard output

     [1, 4, 9]

The *note multiprocessing: 98. module also introduces APIs which do not
have analogs in the *note threading: f3. module, like the ability to
*note terminate: 183f, *note interrupt: 251. or *note kill: d51. a
running process.

Vedi anche
..........

*note concurrent.futures.ProcessPoolExecutor: 1d6. offers a higher level
interface to push tasks to a background process without blocking
execution of the calling process.  Compared to using the *note Pool:
116d. interface directly, the *note concurrent.futures: 24. API more
readily allows the submission of work to the underlying process pool to
be separated from waiting for the results.

* Menu:

* The Process class::
* Contexts and start methods::
* Exchanging objects between processes::
* Synchronization between processes::
* Sharing state between processes::
* Using a pool of workers::


File: python.info,  Node: The Process class,  Next: Contexts and start methods,  Up: Introduction<8>

5.18.2.2 The ‘Process’ class
............................

In *note multiprocessing: 98, processes are spawned by creating a *note
Process: 252. object and then calling its *note start(): 1599. method.
*note Process: 252. follows the API of *note threading.Thread: 176.  A
trivial example of a multiprocess program is

     from multiprocessing import Process

     def f(name):
         print('hello', name)

     if __name__ == '__main__':
         p = Process(target=f, args=('bob',))
         p.start()
         p.join()

To show the individual process IDs involved, here is an expanded
example:

     from multiprocessing import Process
     import os

     def info(title):
         print(title)
         print('module name:', __name__)
         print('parent process:', os.getppid())
         print('process id:', os.getpid())

     def f(name):
         info('function f')
         print('hello', name)

     if __name__ == '__main__':
         info('main line')
         p = Process(target=f, args=('bob',))
         p.start()
         p.join()

For an explanation of why the ‘if __name__ == '__main__'’ part is
necessary, see *note Programming guidelines: 362e.

The arguments to *note Process: 252. usually need to be unpickleable
from within the child process.  If you tried typing the above example
directly into a REPL it could lead to an *note AttributeError: 5f0. in
the child process trying to locate the 'f' function in the ‘__main__’
module.


File: python.info,  Node: Contexts and start methods,  Next: Exchanging objects between processes,  Prev: The Process class,  Up: Introduction<8>

5.18.2.3 Contexts and start methods
...................................

Depending on the platform, *note multiprocessing: 98. supports three
ways to start a process.  These 'start methods' are

     'spawn'

          The parent process starts a fresh Python interpreter process.
          The child process will only inherit those resources necessary
          to run the process object’s *note run(): 3630. method.  In
          particular, unnecessary file descriptors and handles from the
          parent process will not be inherited.  Starting a process
          using this method is rather slow compared to using 'fork' or
          'forkserver'.

          Available on POSIX and Windows platforms.  The default on
          Windows and macOS.

     'fork'

          The parent process uses *note os.fork(): 4b6. to fork the
          Python interpreter.  The child process, when it begins, is
          effectively identical to the parent process.  All resources of
          the parent are inherited by the child process.  Note that
          safely forking a multithreaded process is problematic.

          Available on POSIX systems.

          Cambiato nella versione 3.14: This is no longer the default
          start method on any platform.  Code that requires 'fork' must
          explicitly specify that via *note get_context(): 24a. or *note
          set_start_method(): 24b.

          Cambiato nella versione 3.12: If Python is able to detect that
          your process has multiple threads, the *note os.fork(): 4b6.
          function that this start method calls internally will raise a
          *note DeprecationWarning: 1a3.  Use a different start method.
          See the *note os.fork(): 4b6. documentation for further
          explanation.

     'forkserver'

          When the program starts and selects the 'forkserver' start
          method, a server process is spawned.  From then on, whenever a
          new process is needed, the parent process connects to the
          server and requests that it fork a new process.  The fork
          server process is single threaded unless system libraries or
          preloaded imports spawn threads as a side-effect so it is
          generally safe for it to use *note os.fork(): 4b6.  No
          unnecessary resources are inherited.

          Available on POSIX platforms which support passing file
          descriptors over Unix pipes such as Linux.  The default on
          those.

          Cambiato nella versione 3.14: This became the default start
          method on POSIX platforms.

Cambiato nella versione 3.4: 'spawn' added on all POSIX platforms, and
'forkserver' added for some POSIX platforms.  Child processes no longer
inherit all of the parents inheritable handles on Windows.

Cambiato nella versione 3.8: On macOS, the 'spawn' start method is now
the default.  The 'fork' start method should be considered unsafe as it
can lead to crashes of the subprocess as macOS system libraries may
start threads.  See bpo-33725(1).

Cambiato nella versione 3.14: On POSIX platforms the default start
method was changed from 'fork' to 'forkserver' to retain the performance
but avoid common multithreaded process incompatibilities.  See
gh-84559(2).

On POSIX using the 'spawn' or 'forkserver' start methods will also start
a 'resource tracker' process which tracks the unlinked named system
resources (such as named semaphores or *note SharedMemory: 19c0.
objects) created by processes of the program.  When all processes have
exited the resource tracker unlinks any remaining tracked object.
Usually there should be none, but if a process was killed by a signal
there may be some «leaked» resources.  (Neither leaked semaphores nor
shared memory segments will be automatically unlinked until the next
reboot.  This is problematic for both objects because the system allows
only a limited number of named semaphores, and shared memory segments
occupy some space in the main memory.)

To select a start method you use the *note set_start_method(): 24b. in
the ‘if __name__ == '__main__'’ clause of the main module.  For example:

     import multiprocessing as mp

     def foo(q):
         q.put('hello')

     if __name__ == '__main__':
         mp.set_start_method('spawn')
         q = mp.Queue()
         p = mp.Process(target=foo, args=(q,))
         p.start()
         print(q.get())
         p.join()

*note set_start_method(): 24b. should not be used more than once in the
program.

Alternatively, you can use *note get_context(): 24a. to obtain a context
object.  Context objects have the same API as the multiprocessing
module, and allow one to use multiple start methods in the same program.

     import multiprocessing as mp

     def foo(q):
         q.put('hello')

     if __name__ == '__main__':
         ctx = mp.get_context('spawn')
         q = ctx.Queue()
         p = ctx.Process(target=foo, args=(q,))
         p.start()
         print(q.get())
         p.join()

Note that objects related to one context may not be compatible with
processes for a different context.  In particular, locks created using
the 'fork' context cannot be passed to processes started using the
'spawn' or 'forkserver' start methods.

Libraries using *note multiprocessing: 98. or *note ProcessPoolExecutor:
1d6. should be designed to allow their users to provide their own
multiprocessing context.  Using a specific context of your own within a
library can lead to incompatibilities with the rest of the library
user’s application.  Always document if your library requires a specific
start method.

     Avvertimento: The ‘'spawn'’ and ‘'forkserver'’ start methods
     generally cannot be used with «frozen» executables (i.e., binaries
     produced by packages like 'PyInstaller' and 'cx_Freeze') on POSIX
     systems.  The ‘'fork'’ start method may work if code does not use
     threads.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33725

   (2) https://github.com/python/cpython/issues/84559


File: python.info,  Node: Exchanging objects between processes,  Next: Synchronization between processes,  Prev: Contexts and start methods,  Up: Introduction<8>

5.18.2.4 Exchanging objects between processes
.............................................

*note multiprocessing: 98. supports two types of communication channel
between processes:

'Queues'

     The *note Queue: 1b71. class is a near clone of *note queue.Queue:
     159c.  For example:

          from multiprocessing import Process, Queue

          def f(q):
              q.put([42, None, 'hello'])

          if __name__ == '__main__':
              q = Queue()
              p = Process(target=f, args=(q,))
              p.start()
              print(q.get())    # prints "[42, None, 'hello']"
              p.join()

     Queues are thread and process safe.  Any object put into a *note
     multiprocessing: 98. queue will be serialized.

'Pipes'

     The *note Pipe(): 3632. function returns a pair of connection
     objects connected by a pipe which by default is duplex (two-way).
     For example:

          from multiprocessing import Process, Pipe

          def f(conn):
              conn.send([42, None, 'hello'])
              conn.close()

          if __name__ == '__main__':
              parent_conn, child_conn = Pipe()
              p = Process(target=f, args=(child_conn,))
              p.start()
              print(parent_conn.recv())   # prints "[42, None, 'hello']"
              p.join()

     The two connection objects returned by *note Pipe(): 3632.
     represent the two ends of the pipe.  Each connection object has
     ‘send()’ and ‘recv()’ methods (among others).  Note that data in a
     pipe may become corrupted if two processes (or threads) try to read
     from or write to the 'same' end of the pipe at the same time.  Of
     course there is no risk of corruption from processes using
     different ends of the pipe at the same time.

     The ‘send()’ method serializes the object and ‘recv()’ re-creates
     the object.


File: python.info,  Node: Synchronization between processes,  Next: Sharing state between processes,  Prev: Exchanging objects between processes,  Up: Introduction<8>

5.18.2.5 Synchronization between processes
..........................................

*note multiprocessing: 98. contains equivalents of all the
synchronization primitives from *note threading: f3.  For instance one
can use a lock to ensure that only one process prints to standard output
at a time:

     from multiprocessing import Process, Lock

     def f(l, i):
         l.acquire()
         try:
             print('hello world', i)
         finally:
             l.release()

     if __name__ == '__main__':
         lock = Lock()

         for num in range(10):
             Process(target=f, args=(lock, num)).start()

Without using the lock output from the different processes is liable to
get all mixed up.


File: python.info,  Node: Sharing state between processes,  Next: Using a pool of workers,  Prev: Synchronization between processes,  Up: Introduction<8>

5.18.2.6 Sharing state between processes
........................................

As mentioned above, when doing concurrent programming it is usually best
to avoid using shared state as far as possible.  This is particularly
true when using multiple processes.

However, if you really do need to use some shared data then *note
multiprocessing: 98. provides a couple of ways of doing so.

'Shared memory'

     Data can be stored in a shared memory map using *note Value: 3635.
     or *note Array: 3636.  For example, the following code

          from multiprocessing import Process, Value, Array

          def f(n, a):
              n.value = 3.1415927
              for i in range(len(a)):
                  a[i] = -a[i]

          if __name__ == '__main__':
              num = Value('d', 0.0)
              arr = Array('i', range(10))

              p = Process(target=f, args=(num, arr))
              p.start()
              p.join()

              print(num.value)
              print(arr[:])

     will print

          3.1415927
          [0, -1, -2, -3, -4, -5, -6, -7, -8, -9]

     The ‘'d'’ and ‘'i'’ arguments used when creating ‘num’ and ‘arr’
     are typecodes of the kind used by the *note array: 8. module: ‘'d'’
     indicates a double precision float and ‘'i'’ indicates a signed
     integer.  These shared objects will be process and thread-safe.

     For more flexibility in using shared memory one can use the *note
     multiprocessing.sharedctypes: 9e. module which supports the
     creation of arbitrary ctypes objects allocated from shared memory.

'Server process'

     A manager object returned by *note Manager(): 250. controls a
     server process which holds Python objects and allows other
     processes to manipulate them using proxies.

     A manager returned by *note Manager(): 250. will support types
     *note list: 24d, *note dict: 183, *note set: 184, *note Namespace:
     3637, *note Lock: 183b, *note RLock: 183c, *note Semaphore: 3638,
     *note BoundedSemaphore: 3639, *note Condition: 363a, *note Event:
     1bee, *note Barrier: 363b, *note Queue: 1b71, *note Value: 3635.
     and *note Array: 3636.  For example,

          from multiprocessing import Process, Manager

          def f(d, l, s):
              d[1] = '1'
              d['2'] = 2
              d[0.25] = None
              l.reverse()
              s.add('a')
              s.add('b')

          if __name__ == '__main__':
              with Manager() as manager:
                  d = manager.dict()
                  l = manager.list(range(10))
                  s = manager.set()

                  p = Process(target=f, args=(d, l, s))
                  p.start()
                  p.join()

                  print(d)
                  print(l)
                  print(s)

     will print

          {0.25: None, 1: '1', '2': 2}
          [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
          {'a', 'b'}

     Server process managers are more flexible than using shared memory
     objects because they can be made to support arbitrary object types.
     Also, a single manager can be shared by processes on different
     computers over a network.  They are, however, slower than using
     shared memory.


File: python.info,  Node: Using a pool of workers,  Prev: Sharing state between processes,  Up: Introduction<8>

5.18.2.7 Using a pool of workers
................................

The *note Pool: 116d. class represents a pool of worker processes.  It
has methods which allows tasks to be offloaded to the worker processes
in a few different ways.

For example:

     from multiprocessing import Pool, TimeoutError
     import time
     import os

     def f(x):
         return x*x

     if __name__ == '__main__':
         # start 4 worker processes
         with Pool(processes=4) as pool:

             # print "[0, 1, 4,..., 81]"
             print(pool.map(f, range(10)))

             # print same numbers in arbitrary order
             for i in pool.imap_unordered(f, range(10)):
                 print(i)

             # evaluate "f(20)" asynchronously
             res = pool.apply_async(f, (20,))      # runs in *only* one process
             print(res.get(timeout=1))             # prints "400"

             # evaluate "os.getpid()" asynchronously
             res = pool.apply_async(os.getpid, ()) # runs in *only* one process
             print(res.get(timeout=1))             # prints the PID of that process

             # launching multiple evaluations asynchronously *may* use more processes
             multiple_results = [pool.apply_async(os.getpid, ()) for i in range(4)]
             print([res.get(timeout=1) for res in multiple_results])

             # make a single worker sleep for 10 seconds
             res = pool.apply_async(time.sleep, (10,))
             try:
                 print(res.get(timeout=1))
             except TimeoutError:
                 print("We lacked patience and got a multiprocessing.TimeoutError")

             print("For the moment, the pool remains available for more work")

         # exiting the 'with'-block has stopped the pool
         print("Now the pool is closed and no longer available")

Note that the methods of a pool should only ever be used by the process
which created it.

     Nota: Functionality within this package requires that the
     ‘__main__’ module be importable by the children.  This is covered
     in *note Programming guidelines: 362e. however it is worth pointing
     out here.  This means that some examples, such as the *note
     multiprocessing.pool.Pool: 116d. examples will not work in the
     interactive interpreter.  For example:

          >>> from multiprocessing import Pool
          >>> p = Pool(5)
          >>> def f(x):
          ...     return x*x
          ...
          >>> with p:
          ...     p.map(f, [1,2,3])
          Process PoolWorker-1:
          Process PoolWorker-2:
          Process PoolWorker-3:
          Traceback (most recent call last):
          Traceback (most recent call last):
          Traceback (most recent call last):
          AttributeError: Can't get attribute 'f' on <module '__main__' (<class '_frozen_importlib.BuiltinImporter'>)>
          AttributeError: Can't get attribute 'f' on <module '__main__' (<class '_frozen_importlib.BuiltinImporter'>)>
          AttributeError: Can't get attribute 'f' on <module '__main__' (<class '_frozen_importlib.BuiltinImporter'>)>

     (If you try this it will actually output three full tracebacks
     interleaved in a semi-random fashion, and then you may have to stop
     the parent process somehow.)


File: python.info,  Node: Reference<3>,  Next: Programming guidelines,  Prev: Introduction<8>,  Up: multiprocessing — Process-based parallelism

5.18.2.8 Reference
..................

The *note multiprocessing: 98. package mostly replicates the API of the
*note threading: f3. module.

* Menu:

* Global start method::
* Process and exceptions::
* Pipes and Queues::
* Miscellaneous: Miscellaneous<4>.
* Connection Objects::
* Synchronization primitives::
* Shared ctypes Objects::
* Managers::
* Proxy Objects::
* Process Pools::
* Listeners and Clients::
* Authentication keys::
* Logging: Logging<2>.
* The multiprocessing.dummy module: The multiprocessing dummy module.


File: python.info,  Node: Global start method,  Next: Process and exceptions,  Up: Reference<3>

5.18.2.9 Global start method
............................

Python supports several ways to create and initialize a process.  The
global start method sets the default mechanism for creating a process.

Several multiprocessing functions and methods that may also instantiate
certain objects will implicitly set the global start method to the
system’s default, if it hasn’t been set already.  The global start
method can only be set once.  If you need to change the start method
from the system default, you must proactively set the global start
method before calling functions or methods, or creating these objects.


File: python.info,  Node: Process and exceptions,  Next: Pipes and Queues,  Prev: Global start method,  Up: Reference<3>

5.18.2.10 ‘Process’ and exceptions
..................................

 -- Classe: multiprocessing.Process (group=None, target=None, name=None,
          args=(), kwargs={}, *, daemon=None)

     Process objects represent activity that is run in a separate
     process.  The *note Process: 252. class has equivalents of all the
     methods of *note threading.Thread: 176.

     The constructor should always be called with keyword arguments.
     'group' should always be ‘None’; it exists solely for compatibility
     with *note threading.Thread: 176.  'target' is the callable object
     to be invoked by the *note run(): 3630. method.  It defaults to
     ‘None’, meaning nothing is called.  'name' is the process name (see
     *note name: 3641. for more details).  'args' is the argument tuple
     for the target invocation.  'kwargs' is a dictionary of keyword
     arguments for the target invocation.  If provided, the keyword-only
     'daemon' argument sets the process *note daemon: 3642. flag to
     ‘True’ or ‘False’.  If ‘None’ (the default), this flag will be
     inherited from the creating process.

     By default, no arguments are passed to 'target'.  The 'args'
     argument, which defaults to ‘()’, can be used to specify a list or
     tuple of the arguments to pass to 'target'.

     If a subclass overrides the constructor, it must make sure it
     invokes the base class constructor (‘super().__init__()’) before
     doing anything else to the process.

          Nota: In general, all arguments to *note Process: 252. must be
          picklable.  This is frequently observed when trying to create
          a *note Process: 252. or use a *note
          concurrent.futures.ProcessPoolExecutor: 1d6. from a REPL with
          a locally defined 'target' function.

          Passing a callable object defined in the current REPL session
          causes the child process to die via an uncaught *note
          AttributeError: 5f0. exception when starting as 'target' must
          have been defined within an importable module in order to be
          loaded during unpickling.

          Example of this uncatchable error from the child:

               >>> import multiprocessing as mp
               >>> def knigit():
               ...     print("Ni!")
               ...
               >>> process = mp.Process(target=knigit)
               >>> process.start()
               >>> Traceback (most recent call last):
                 File ".../multiprocessing/spawn.py", line ..., in spawn_main
                 File ".../multiprocessing/spawn.py", line ..., in _main
               AttributeError: module '__main__' has no attribute 'knigit'
               >>> process
               <SpawnProcess name='SpawnProcess-1' pid=379473 parent=378707 stopped exitcode=1>

          See *note The spawn and forkserver start methods: 3643.  While
          this restriction is not true if using the ‘"fork"’ start
          method, as of Python ‘3.14’ that is no longer the default on
          any platform.  See *note Contexts and start methods: 1d5.  See
          also gh-132898(1).

     Cambiato nella versione 3.3: Added the 'daemon' parameter.

      -- Metodo: run ()

          Method representing the process’s activity.

          You may override this method in a subclass.  The standard
          *note run(): 3630. method invokes the callable object passed
          to the object’s constructor as the target argument, if any,
          with sequential and keyword arguments taken from the 'args'
          and 'kwargs' arguments, respectively.

          Using a list or tuple as the 'args' argument passed to *note
          Process: 252. achieves the same effect.

          Example:

               >>> from multiprocessing import Process
               >>> p = Process(target=print, args=[1])
               >>> p.run()
               1
               >>> p = Process(target=print, args=(1,))
               >>> p.run()
               1

      -- Metodo: start ()

          Start the process’s activity.

          This must be called at most once per process object.  It
          arranges for the object’s *note run(): 3630. method to be
          invoked in a separate process.

      -- Metodo: join ([timeout])

          If the optional argument 'timeout' is ‘None’ (the default),
          the method blocks until the process whose *note join(): 159b.
          method is called terminates.  If 'timeout' is a positive
          number, it blocks at most 'timeout' seconds.  Note that the
          method returns ‘None’ if its process terminates or if the
          method times out.  Check the process’s *note exitcode: 3644.
          to determine if it terminated.

          A process can be joined many times.

          A process cannot join itself because this would cause a
          deadlock.  It is an error to attempt to join a process before
          it has been started.

      -- Attributo: name

          The process’s name.  The name is a string used for
          identification purposes only.  It has no semantics.  Multiple
          processes may be given the same name.

          The initial name is set by the constructor.  If no explicit
          name is provided to the constructor, a name of the form
          “Process-N[1]:N[2]:…:N[k]” is constructed, where each N[k] is
          the N-th child of its parent.

      -- Metodo: is_alive ()

          Return whether the process is alive.

          Roughly, a process object is alive from the moment the *note
          start(): 1599. method returns until the child process
          terminates.

      -- Attributo: daemon

          The process’s daemon flag, a Boolean value.  This must be set
          before *note start(): 1599. is called.

          The initial value is inherited from the creating process.

          When a process exits, it attempts to terminate all of its
          daemonic child processes.

          Note that a daemonic process is not allowed to create child
          processes.  Otherwise a daemonic process would leave its
          children orphaned if it gets terminated when its parent
          process exits.  Additionally, these are 'not' Unix daemons or
          services, they are normal processes that will be terminated
          (and not joined) if non-daemonic processes have exited.

     In addition to the *note threading.Thread: 176. API, *note Process:
     252. objects also support the following attributes and methods:

      -- Attributo: pid

          Return the process ID. Before the process is spawned, this
          will be ‘None’.

      -- Attributo: exitcode

          The child’s exit code.  This will be ‘None’ if the process has
          not yet terminated.

          If the child’s *note run(): 3630. method returned normally,
          the exit code will be 0.  If it terminated via *note
          sys.exit(): 277. with an integer argument 'N', the exit code
          will be 'N'.

          If the child terminated due to an exception not caught within
          *note run(): 3630, the exit code will be 1.  If it was
          terminated by signal 'N', the exit code will be the negative
          value '-N'.

      -- Attributo: authkey

          The process’s authentication key (a byte string).

          When *note multiprocessing: 98. is initialized the main
          process is assigned a random string using *note os.urandom():
          747.

          When a *note Process: 252. object is created, it will inherit
          the authentication key of its parent process, although this
          may be changed by setting *note authkey: 3646. to another byte
          string.

          See *note Authentication keys: 3647.

      -- Attributo: sentinel

          A numeric handle of a system object which will become «ready»
          when the process ends.

          You can use this value if you want to wait on several events
          at once using *note multiprocessing.connection.wait(): 12e7.
          Otherwise calling *note join(): 159b. is simpler.

          On Windows, this is an OS handle usable with the
          ‘WaitForSingleObject’ and ‘WaitForMultipleObjects’ family of
          API calls.  On POSIX, this is a file descriptor usable with
          primitives from the *note select: c6. module.

          Added in version 3.3.

      -- Metodo: interrupt ()

          Terminate the process.  Works on POSIX using the *note SIGINT:
          253. signal.  Behavior on Windows is undefined.

          By default, this terminates the child process by raising *note
          KeyboardInterrupt: bc7.  This behavior can be altered by
          setting the respective signal handler in the child process
          *note signal.signal(): 133c. for *note SIGINT: 253.

          Note: if the child process catches and discards *note
          KeyboardInterrupt: bc7, the process will not be terminated.

          Note: the default behavior will also set *note exitcode: 3644.
          to ‘1’ as if an uncaught exception was raised in the child
          process.  To have a different *note exitcode: 3644. you may
          simply catch *note KeyboardInterrupt: bc7. and call
          ‘exit(your_code)’.

          Added in version 3.14.

      -- Metodo: terminate ()

          Terminate the process.  On POSIX this is done using the *note
          SIGTERM: 15e6. signal; on Windows ‘TerminateProcess()’ is
          used.  Note that exit handlers and finally clauses, etc., will
          not be executed.

          Note that descendant processes of the process will 'not' be
          terminated – they will simply become orphaned.

               Avvertimento: If this method is used when the associated
               process is using a pipe or queue then the pipe or queue
               is liable to become corrupted and may become unusable by
               other process.  Similarly, if the process has acquired a
               lock or semaphore etc.  then terminating it is liable to
               cause other processes to deadlock.

      -- Metodo: kill ()

          Same as *note terminate(): 183f. but using the ‘SIGKILL’
          signal on POSIX.

          Added in version 3.7.

      -- Metodo: close ()

          Close the *note Process: 252. object, releasing all resources
          associated with it.  *note ValueError: 2ec. is raised if the
          underlying process is still running.  Once *note close(): d50.
          returns successfully, most other methods and attributes of the
          *note Process: 252. object will raise *note ValueError: 2ec.

          Added in version 3.7.

     Note that the *note start(): 1599, *note join(): 159b, *note
     is_alive(): 159a, *note terminate(): 183f. and *note exitcode:
     3644. methods should only be called by the process that created the
     process object.

     Example usage of some of the methods of *note Process: 252.:

          >>> import multiprocessing, time, signal
          >>> mp_context = multiprocessing.get_context('spawn')
          >>> p = mp_context.Process(target=time.sleep, args=(1000,))
          >>> print(p, p.is_alive())
          <...Process ... initial> False
          >>> p.start()
          >>> print(p, p.is_alive())
          <...Process ... started> True
          >>> p.terminate()
          >>> time.sleep(0.1)
          >>> print(p, p.is_alive())
          <...Process ... stopped exitcode=-SIGTERM> False
          >>> p.exitcode == -signal.SIGTERM
          True

 -- Eccezione: multiprocessing.ProcessError

     The base class of all *note multiprocessing: 98. exceptions.

 -- Eccezione: multiprocessing.BufferTooShort

     Exception raised by ‘Connection.recv_bytes_into()’ when the
     supplied buffer object is too small for the message read.

     If ‘e’ is an instance of *note BufferTooShort: 3649. then
     ‘e.args[0]’ will give the message as a byte string.

 -- Eccezione: multiprocessing.AuthenticationError

     Raised when there is an authentication error.

 -- Eccezione: multiprocessing.TimeoutError

     Raised by methods with a timeout when the timeout expires.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/132898


File: python.info,  Node: Pipes and Queues,  Next: Miscellaneous<4>,  Prev: Process and exceptions,  Up: Reference<3>

5.18.2.11 Pipes and Queues
..........................

When using multiple processes, one generally uses message passing for
communication between processes and avoids having to use any
synchronization primitives like locks.

For passing messages one can use *note Pipe(): 3632. (for a connection
between two processes) or a queue (which allows multiple producers and
consumers).

The *note Queue: 1b71, *note SimpleQueue: b12. and *note JoinableQueue:
364d. types are multi-producer, multi-consumer FIFO queues modelled on
the *note queue.Queue: 159c. class in the standard library.  They differ
in that *note Queue: 1b71. lacks the *note task_done(): 364e. and *note
join(): 364f. methods introduced into Python 2.5’s *note queue.Queue:
159c. class.

If you use *note JoinableQueue: 364d. then you 'must' call *note
JoinableQueue.task_done(): 3650. for each task removed from the queue or
else the semaphore used to count the number of unfinished tasks may
eventually overflow, raising an exception.

One difference from other Python queue implementations, is that *note
multiprocessing: 98. queues serializes all objects that are put into
them using *note pickle: ab.  The object returned by the get method is a
re-created object that does not share memory with the original object.

Note that one can also create a shared queue by using a manager object –
see *note Managers: 3651.

     Nota: *note multiprocessing: 98. uses the usual *note queue.Empty:
     3652. and *note queue.Full: 3653. exceptions to signal a timeout.
     They are not available in the *note multiprocessing: 98. namespace
     so you need to import them from *note queue: bb.

     Nota: When an object is put on a queue, the object is pickled and a
     background thread later flushes the pickled data to an underlying
     pipe.  This has some consequences which are a little surprising,
     but should not cause any practical difficulties – if they really
     bother you then you can instead use a queue created with a *note
     manager: 3651.

       1. After putting an object on an empty queue there may be an
          infinitesimal delay before the queue’s *note empty(): 1950.
          method returns *note False: d2d. and *note get_nowait(): 3654.
          can return without raising *note queue.Empty: 3652.

       2. If multiple processes are enqueuing objects, it is possible
          for the objects to be received at the other end out-of-order.
          However, objects enqueued by the same process will always be
          in the expected order with respect to each other.

     Avvertimento: If a process is killed using *note
     Process.terminate(): 183f. or *note os.kill(): 156f. while it is
     trying to use a *note Queue: 1b71, then the data in the queue is
     likely to become corrupted.  This may cause any other process to
     get an exception when it tries to use the queue later on.

     Avvertimento: As mentioned above, if a child process has put items
     on a queue (and it has not used *note
     JoinableQueue.cancel_join_thread: 3655.), then that process will
     not terminate until all buffered items have been flushed to the
     pipe.

     This means that if you try joining that process you may get a
     deadlock unless you are sure that all items which have been put on
     the queue have been consumed.  Similarly, if the child process is
     non-daemonic then the parent process may hang on exit when it tries
     to join all its non-daemonic children.

     Note that a queue created using a manager does not have this issue.
     See *note Programming guidelines: 362e.

For an example of the usage of queues for interprocess communication see
*note Examples: 3656.

 -- Funzione: multiprocessing.Pipe (duplex=True)

     Returns a pair ‘(conn1, conn2)’ of *note Connection: 12e8. objects
     representing the ends of a pipe.

     If 'duplex' is ‘True’ (the default) then the pipe is bidirectional.
     If 'duplex' is ‘False’ then the pipe is unidirectional: ‘conn1’ can
     only be used for receiving messages and ‘conn2’ can only be used
     for sending messages.

     The ‘send()’ method serializes the object using *note pickle: ab.
     and the ‘recv()’ re-creates the object.

 -- Classe: multiprocessing.Queue ([maxsize])

     Returns a process shared queue implemented using a pipe and a few
     locks/semaphores.  When a process first puts an item on the queue a
     feeder thread is started which transfers objects from a buffer into
     the pipe.

     Instantiating this class may set the global start method.  See
     *note Global start method: 363e. for more details.

     The usual *note queue.Empty: 3652. and *note queue.Full: 3653.
     exceptions from the standard library’s *note queue: bb. module are
     raised to signal timeouts.

     *note Queue: 1b71. implements all the methods of *note queue.Queue:
     159c. except for *note task_done(): 364e. and *note join(): 364f.

      -- Metodo: qsize ()

          Return the approximate size of the queue.  Because of
          multithreading/multiprocessing semantics, this number is not
          reliable.

          Note that this may raise *note NotImplementedError: 36b. on
          platforms like macOS where ‘sem_getvalue()’ is not
          implemented.

      -- Metodo: empty ()

          Return ‘True’ if the queue is empty, ‘False’ otherwise.
          Because of multithreading/multiprocessing semantics, this is
          not reliable.

          May raise an *note OSError: 2c0. on closed queues.  (not
          guaranteed)

      -- Metodo: full ()

          Return ‘True’ if the queue is full, ‘False’ otherwise.
          Because of multithreading/multiprocessing semantics, this is
          not reliable.

      -- Metodo: put (obj[, block[, timeout]])

          Put obj into the queue.  If the optional argument 'block' is
          ‘True’ (the default) and 'timeout' is ‘None’ (the default),
          block if necessary until a free slot is available.  If
          'timeout' is a positive number, it blocks at most 'timeout'
          seconds and raises the *note queue.Full: 3653. exception if no
          free slot was available within that time.  Otherwise ('block'
          is ‘False’), put an item on the queue if a free slot is
          immediately available, else raise the *note queue.Full: 3653.
          exception ('timeout' is ignored in that case).

          Cambiato nella versione 3.8: If the queue is closed, *note
          ValueError: 2ec. is raised instead of *note AssertionError:
          8b9.

      -- Metodo: put_nowait (obj)

          Equivalent to ‘put(obj, False)’.

      -- Metodo: get ([block[, timeout]])

          Remove and return an item from the queue.  If optional args
          'block' is ‘True’ (the default) and 'timeout' is ‘None’ (the
          default), block if necessary until an item is available.  If
          'timeout' is a positive number, it blocks at most 'timeout'
          seconds and raises the *note queue.Empty: 3652. exception if
          no item was available within that time.  Otherwise (block is
          ‘False’), return an item if one is immediately available, else
          raise the *note queue.Empty: 3652. exception ('timeout' is
          ignored in that case).

          Cambiato nella versione 3.8: If the queue is closed, *note
          ValueError: 2ec. is raised instead of *note OSError: 2c0.

      -- Metodo: get_nowait ()

          Equivalent to ‘get(False)’.

     *note multiprocessing.Queue: 1b71. has a few additional methods not
     found in *note queue.Queue: 159c.  These methods are usually
     unnecessary for most code:

      -- Metodo: close ()

          Close the queue: release internal resources.

          A queue must not be used anymore after it is closed.  For
          example, *note get(): 1e06, *note put(): 1e05. and *note
          empty(): 1950. methods must no longer be called.

          The background thread will quit once it has flushed all
          buffered data to the pipe.  This is called automatically when
          the queue is garbage collected.

      -- Metodo: join_thread ()

          Join the background thread.  This can only be used after *note
          close(): 1b72. has been called.  It blocks until the
          background thread exits, ensuring that all data in the buffer
          has been flushed to the pipe.

          By default if a process is not the creator of the queue then
          on exit it will attempt to join the queue’s background thread.
          The process can call *note cancel_join_thread(): 3655. to make
          *note join_thread(): 365a. do nothing.

      -- Metodo: cancel_join_thread ()

          Prevent *note join_thread(): 365a. from blocking.  In
          particular, this prevents the background thread from being
          joined automatically when the process exits – see *note
          join_thread(): 365a.

          A better name for this method might be
          ‘allow_exit_without_flush()’.  It is likely to cause enqueued
          data to be lost, and you almost certainly will not need to use
          it.  It is really only there if you need the current process
          to exit immediately without waiting to flush enqueued data to
          the underlying pipe, and you don’t care about lost data.

          Nota: This class’s functionality requires a functioning shared
          semaphore implementation on the host operating system.
          Without one, the functionality in this class will be disabled,
          and attempts to instantiate a *note Queue: 1b71. will result
          in an *note ImportError: 65b.  See bpo-3770(1) for additional
          information.  The same holds true for any of the specialized
          queue types listed below.

 -- Classe: multiprocessing.SimpleQueue

     It is a simplified *note Queue: 1b71. type, very close to a locked
     *note Pipe: 3632.

     Instantiating this class may set the global start method.  See
     *note Global start method: 363e. for more details.

      -- Metodo: close ()

          Close the queue: release internal resources.

          A queue must not be used anymore after it is closed.  For
          example, *note get(): 365b, *note put(): 365c. and *note
          empty(): 1951. methods must no longer be called.

          Added in version 3.9.

      -- Metodo: empty ()

          Return ‘True’ if the queue is empty, ‘False’ otherwise.

          Always raises an *note OSError: 2c0. if the SimpleQueue is
          closed.

      -- Metodo: get ()

          Remove and return an item from the queue.

      -- Metodo: put (item)

          Put 'item' into the queue.

 -- Classe: multiprocessing.JoinableQueue ([maxsize])

     *note JoinableQueue: 364d, a *note Queue: 1b71. subclass, is a
     queue which additionally has *note task_done(): 3650. and *note
     join(): 365d. methods.

     Instantiating this class may set the global start method.  See
     *note Global start method: 363e. for more details.

      -- Metodo: task_done ()

          Indicate that a formerly enqueued task is complete.  Used by
          queue consumers.  For each *note get(): 1e06. used to fetch a
          task, a subsequent call to *note task_done(): 3650. tells the
          queue that the processing on the task is complete.

          If a *note join(): 364f. is currently blocking, it will resume
          when all items have been processed (meaning that a *note
          task_done(): 3650. call was received for every item that had
          been *note put(): 1e05. into the queue).

          Raises a *note ValueError: 2ec. if called more times than
          there were items placed in the queue.

      -- Metodo: join ()

          Block until all items in the queue have been gotten and
          processed.

          The count of unfinished tasks goes up whenever an item is
          added to the queue.  The count goes down whenever a consumer
          calls *note task_done(): 3650. to indicate that the item was
          retrieved and all work on it is complete.  When the count of
          unfinished tasks drops to zero, *note join(): 364f. unblocks.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=3770


File: python.info,  Node: Miscellaneous<4>,  Next: Connection Objects,  Prev: Pipes and Queues,  Up: Reference<3>

5.18.2.12 Miscellaneous
.......................

 -- Funzione: multiprocessing.active_children ()

     Return list of all live children of the current process.

     Calling this has the side effect of «joining» any processes which
     have already finished.

 -- Funzione: multiprocessing.cpu_count ()

     Return the number of CPUs in the system.

     This number is not equivalent to the number of CPUs the current
     process can use.  The number of usable CPUs can be obtained with
     *note os.process_cpu_count(): 4db. (or
     ‘len(os.sched_getaffinity(0))’).

     When the number of CPUs cannot be determined a *note
     NotImplementedError: 36b. is raised.

     Vedi anche
     ..........

     *note os.cpu_count(): 4dc. *note os.process_cpu_count(): 4db.

     Cambiato nella versione 3.13: The return value can also be
     overridden using the *note -X cpu_count: 16f. flag or *note
     PYTHON_CPU_COUNT: 51f. as this is merely a wrapper around the *note
     os: a5. cpu count APIs.

 -- Funzione: multiprocessing.current_process ()

     Return the *note Process: 252. object corresponding to the current
     process.

     An analogue of *note threading.current_thread(): 35e.

 -- Funzione: multiprocessing.parent_process ()

     Return the *note Process: 252. object corresponding to the parent
     process of the *note current_process(): 3660.  For the main
     process, ‘parent_process’ will be ‘None’.

     Added in version 3.8.

 -- Funzione: multiprocessing.freeze_support ()

     Add support for when a program which uses *note multiprocessing:
     98. has been frozen to produce an executable.  (Has been tested
     with 'py2exe', 'PyInstaller' and 'cx_Freeze'.)

     One needs to call this function straight after the ‘if __name__ ==
     '__main__'’ line of the main module.  For example:

          from multiprocessing import Process, freeze_support

          def f():
              print('hello world!')

          if __name__ == '__main__':
              freeze_support()
              Process(target=f).start()

     If the ‘freeze_support()’ line is omitted then trying to run the
     frozen executable will raise *note RuntimeError: 244.

     Calling ‘freeze_support()’ has no effect when the start method is
     not 'spawn'.  In addition, if the module is being run normally by
     the Python interpreter (the program has not been frozen), then
     ‘freeze_support()’ has no effect.

 -- Funzione: multiprocessing.get_all_start_methods ()

     Returns a list of the supported start methods, the first of which
     is the default.  The possible start methods are ‘'fork'’, ‘'spawn'’
     and ‘'forkserver'’.  Not all platforms support all methods.  See
     *note Contexts and start methods: 1d5.

     Added in version 3.4.

 -- Funzione: multiprocessing.get_context (method=None)

     Return a context object which has the same attributes as the *note
     multiprocessing: 98. module.

     If 'method' is ‘None’ then the default context is returned.  Note
     that if the global start method has not been set, this will set it
     to the system default See *note Global start method: 363e. for more
     details.  Otherwise 'method' should be ‘'fork'’, ‘'spawn'’,
     ‘'forkserver'’.  *note ValueError: 2ec. is raised if the specified
     start method is not available.  See *note Contexts and start
     methods: 1d5.

     Added in version 3.4.

 -- Funzione: multiprocessing.get_start_method (allow_none=False)

     Return the name of start method used for starting processes.

     If the global start method is not set and 'allow_none' is ‘False’,
     the global start method is set to the default, and its name is
     returned.  See *note Global start method: 363e. for more details.

     The return value can be ‘'fork'’, ‘'spawn'’, ‘'forkserver'’ or
     ‘None’.  See *note Contexts and start methods: 1d5.

     Added in version 3.4.

     Cambiato nella versione 3.8: On macOS, the 'spawn' start method is
     now the default.  The 'fork' start method should be considered
     unsafe as it can lead to crashes of the subprocess.  See
     bpo-33725(1).

 -- Funzione: multiprocessing.set_executable (executable)

     Set the path of the Python interpreter to use when starting a child
     process.  (By default *note sys.executable: 3ed. is used).
     Embedders will probably need to do some thing like

          set_executable(os.path.join(sys.exec_prefix, 'pythonw.exe'))

     before they can create child processes.

     Cambiato nella versione 3.4: Now supported on POSIX when the
     ‘'spawn'’ start method is used.

     Cambiato nella versione 3.11: Accepts a *note path-like object:
     5a1.

 -- Funzione: multiprocessing.set_forkserver_preload (module_names)

     Set a list of module names for the forkserver main process to
     attempt to import so that their already imported state is inherited
     by forked processes.  Any *note ImportError: 65b. when doing so is
     silently ignored.  This can be used as a performance enhancement to
     avoid repeated work in every process.

     For this to work, it must be called before the forkserver process
     has been launched (before creating a ‘Pool’ or starting a *note
     Process: 252.).

     Only meaningful when using the ‘'forkserver'’ start method.  See
     *note Contexts and start methods: 1d5.

     Added in version 3.4.

 -- Funzione: multiprocessing.set_start_method (method, force=False)

     Set the method which should be used to start child processes.  The
     'method' argument can be ‘'fork'’, ‘'spawn'’ or ‘'forkserver'’.
     Raises *note RuntimeError: 244. if the start method has already
     been set and 'force' is not ‘True’.  If 'method' is ‘None’ and
     'force' is ‘True’ then the start method is set to ‘None’.  If
     'method' is ‘None’ and 'force' is ‘False’ then the context is set
     to the default context.

     Note that this should be called at most once, and it should be
     protected inside the ‘if __name__ == '__main__'’ clause of the main
     module.

     See *note Contexts and start methods: 1d5.

     Added in version 3.4.

     Nota: *note multiprocessing: 98. contains no analogues of *note
     threading.active_count(): 35f, *note threading.enumerate(): 1c42,
     *note threading.settrace(): a4a, *note threading.setprofile(): a4b,
     *note threading.Timer: 1361, or *note threading.local: 1847.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33725


File: python.info,  Node: Connection Objects,  Next: Synchronization primitives,  Prev: Miscellaneous<4>,  Up: Reference<3>

5.18.2.13 Connection Objects
............................

Connection objects allow the sending and receiving of picklable objects
or strings.  They can be thought of as message oriented connected
sockets.

Connection objects are usually created using *note Pipe: 3632. – see
also *note Listeners and Clients: 3663.

 -- Classe: multiprocessing.connection.Connection

      -- Metodo: send (obj)

          Send an object to the other end of the connection which should
          be read using *note recv(): 3665.

          The object must be picklable.  Very large pickles
          (approximately 32 MiB+, though it depends on the OS) may raise
          a *note ValueError: 2ec. exception.

      -- Metodo: recv ()

          Return an object sent from the other end of the connection
          using *note send(): 3664.  Blocks until there is something to
          receive.  Raises *note EOFError: 14e1. if there is nothing
          left to receive and the other end was closed.

      -- Metodo: fileno ()

          Return the file descriptor or handle used by the connection.

      -- Metodo: close ()

          Close the connection.

          This is called automatically when the connection is garbage
          collected.

      -- Metodo: poll ([timeout])

          Return whether there is any data available to be read.

          If 'timeout' is not specified then it will return immediately.
          If 'timeout' is a number then this specifies the maximum time
          in seconds to block.  If 'timeout' is ‘None’ then an infinite
          timeout is used.

          Note that multiple connection objects may be polled at once by
          using *note multiprocessing.connection.wait(): 12e7.

      -- Metodo: send_bytes (buffer[, offset[, size]])

          Send byte data from a *note bytes-like object: 193. as a
          complete message.

          If 'offset' is given then data is read from that position in
          'buffer'.  If 'size' is given then that many bytes will be
          read from buffer.  Very large buffers (approximately 32 MiB+,
          though it depends on the OS) may raise a *note ValueError:
          2ec. exception

      -- Metodo: recv_bytes ([maxlength])

          Return a complete message of byte data sent from the other end
          of the connection as a string.  Blocks until there is
          something to receive.  Raises *note EOFError: 14e1. if there
          is nothing left to receive and the other end has closed.

          If 'maxlength' is specified and the message is longer than
          'maxlength' then *note OSError: 2c0. is raised and the
          connection will no longer be readable.

          Cambiato nella versione 3.3: This function used to raise *note
          IOError: 1255, which is now an alias of *note OSError: 2c0.

      -- Metodo: recv_bytes_into (buffer[, offset])

          Read into 'buffer' a complete message of byte data sent from
          the other end of the connection and return the number of bytes
          in the message.  Blocks until there is something to receive.
          Raises *note EOFError: 14e1. if there is nothing left to
          receive and the other end was closed.

          'buffer' must be a writable *note bytes-like object: 193.  If
          'offset' is given then the message will be written into the
          buffer from that position.  Offset must be a non-negative
          integer less than the length of 'buffer' (in bytes).

          If the buffer is too short then a ‘BufferTooShort’ exception
          is raised and the complete message is available as ‘e.args[0]’
          where ‘e’ is the exception instance.

     Cambiato nella versione 3.3: Connection objects themselves can now
     be transferred between processes using *note Connection.send():
     3664. and *note Connection.recv(): 3665.

     Connection objects also now support the context management protocol
     – see *note Tipi di gestori di contesti: 23f0.  *note __enter__():
     268b. returns the connection object, and *note __exit__(): 268c.
     calls *note close(): 3667.

For example:

     >>> from multiprocessing import Pipe
     >>> a, b = Pipe()
     >>> a.send([1, 'hello', None])
     >>> b.recv()
     [1, 'hello', None]
     >>> b.send_bytes(b'thank you')
     >>> a.recv_bytes()
     b'thank you'
     >>> import array
     >>> arr1 = array.array('i', range(5))
     >>> arr2 = array.array('i', [0] * 10)
     >>> a.send_bytes(arr1)
     >>> count = b.recv_bytes_into(arr2)
     >>> assert count == len(arr1) * arr1.itemsize
     >>> arr2
     array('i', [0, 1, 2, 3, 4, 0, 0, 0, 0, 0])
     Avvertimento: The *note Connection.recv(): 3665. method
     automatically unpickles the data it receives, which can be a
     security risk unless you can trust the process which sent the
     message.

     Therefore, unless the connection object was produced using ‘Pipe()’
     you should only use the *note recv(): 3665. and *note send(): 3664.
     methods after performing some sort of authentication.  See *note
     Authentication keys: 3647.

     Avvertimento: If a process is killed while it is trying to read or
     write to a pipe then the data in the pipe is likely to become
     corrupted, because it may become impossible to be sure where the
     message boundaries lie.


File: python.info,  Node: Synchronization primitives,  Next: Shared ctypes Objects,  Prev: Connection Objects,  Up: Reference<3>

5.18.2.14 Synchronization primitives
....................................

Generally synchronization primitives are not as necessary in a
multiprocess program as they are in a multithreaded program.  See the
documentation for *note threading: f3. module.

Note that one can also create synchronization primitives by using a
manager object – see *note Managers: 3651.

 -- Classe: multiprocessing.Barrier (parties[, action[, timeout]])

     A barrier object: a clone of *note threading.Barrier: 13eb.

     Instantiating this class may set the global start method.  See
     *note Global start method: 363e. for more details.

     Added in version 3.3.

 -- Classe: multiprocessing.BoundedSemaphore ([value])

     A bounded semaphore object: a close analog of *note
     threading.BoundedSemaphore: 135f.

     Instantiating this class may set the global start method.  See
     *note Global start method: 363e. for more details.

     A solitary difference from its close analog exists: its ‘acquire’
     method’s first argument is named 'block', as is consistent with
     *note Lock.acquire(): 366e.

      -- Metodo: locked ()

          Return a boolean indicating whether this object is locked
          right now.

          Added in version 3.14.

          Nota: On macOS, this is indistinguishable from *note
          Semaphore: 3638. because ‘sem_getvalue()’ is not implemented
          on that platform.

 -- Classe: multiprocessing.Condition ([lock])

     A condition variable: an alias for *note threading.Condition: 135d.

     If 'lock' is specified then it should be a *note Lock: 183b. or
     *note RLock: 183c. object from *note multiprocessing: 98.

     Instantiating this class may set the global start method.  See
     *note Global start method: 363e. for more details.

     Cambiato nella versione 3.3: The *note wait_for(): 3613. method was
     added.

 -- Classe: multiprocessing.Event

     A clone of *note threading.Event: 1360.

     Instantiating this class may set the global start method.  See
     *note Global start method: 363e. for more details.

 -- Classe: multiprocessing.Lock

     A non-recursive lock object: a close analog of *note
     threading.Lock: 19dc.  Once a process or thread has acquired a
     lock, subsequent attempts to acquire it from any process or thread
     will block until it is released; any process or thread may release
     it.  The concepts and behaviors of *note threading.Lock: 19dc. as
     it applies to threads are replicated here in *note
     multiprocessing.Lock: 183b. as it applies to either processes or
     threads, except as noted.

     Note that *note Lock: 183b. is actually a factory function which
     returns an instance of ‘multiprocessing.synchronize.Lock’
     initialized with a default context.

     Instantiating this class may set the global start method.  See
     *note Global start method: 363e. for more details.

     *note Lock: 183b. supports the *note context manager: 1e1. protocol
     and thus may be used in *note with: 186. statements.

      -- Metodo: acquire (block=True, timeout=None)

          Acquire a lock, blocking or non-blocking.

          With the 'block' argument set to ‘True’ (the default), the
          method call will block until the lock is in an unlocked state,
          then set it to locked and return ‘True’.  Note that the name
          of this first argument differs from that in *note
          threading.Lock.acquire(): 8a8.

          With the 'block' argument set to ‘False’, the method call does
          not block.  If the lock is currently in a locked state, return
          ‘False’; otherwise set the lock to a locked state and return
          ‘True’.

          When invoked with a positive, floating-point value for
          'timeout', block for at most the number of seconds specified
          by 'timeout' as long as the lock can not be acquired.
          Invocations with a negative value for 'timeout' are equivalent
          to a 'timeout' of zero.  Invocations with a 'timeout' value of
          ‘None’ (the default) set the timeout period to infinite.  Note
          that the treatment of negative or ‘None’ values for 'timeout'
          differs from the implemented behavior in *note
          threading.Lock.acquire(): 8a8.  The 'timeout' argument has no
          practical implications if the 'block' argument is set to
          ‘False’ and is thus ignored.  Returns ‘True’ if the lock has
          been acquired or ‘False’ if the timeout period has elapsed.

      -- Metodo: release ()

          Release a lock.  This can be called from any process or
          thread, not only the process or thread which originally
          acquired the lock.

          Behavior is the same as in *note threading.Lock.release():
          14ca. except that when invoked on an unlocked lock, a *note
          ValueError: 2ec. is raised.

      -- Metodo: locked ()

          Return a boolean indicating whether this object is locked
          right now.

          Added in version 3.14.

 -- Classe: multiprocessing.RLock

     A recursive lock object: a close analog of *note threading.RLock:
     32e.  A recursive lock must be released by the process or thread
     that acquired it.  Once a process or thread has acquired a
     recursive lock, the same process or thread may acquire it again
     without blocking; that process or thread must release it once for
     each time it has been acquired.

     Note that *note RLock: 183c. is actually a factory function which
     returns an instance of ‘multiprocessing.synchronize.RLock’
     initialized with a default context.

     Instantiating this class may set the global start method.  See
     *note Global start method: 363e. for more details.

     *note RLock: 183c. supports the *note context manager: 1e1.
     protocol and thus may be used in *note with: 186. statements.

      -- Metodo: acquire (block=True, timeout=None)

          Acquire a lock, blocking or non-blocking.

          When invoked with the 'block' argument set to ‘True’, block
          until the lock is in an unlocked state (not owned by any
          process or thread) unless the lock is already owned by the
          current process or thread.  The current process or thread then
          takes ownership of the lock (if it does not already have
          ownership) and the recursion level inside the lock increments
          by one, resulting in a return value of ‘True’.  Note that
          there are several differences in this first argument’s
          behavior compared to the implementation of *note
          threading.RLock.acquire(): 107d, starting with the name of the
          argument itself.

          When invoked with the 'block' argument set to ‘False’, do not
          block.  If the lock has already been acquired (and thus is
          owned) by another process or thread, the current process or
          thread does not take ownership and the recursion level within
          the lock is not changed, resulting in a return value of
          ‘False’.  If the lock is in an unlocked state, the current
          process or thread takes ownership and the recursion level is
          incremented, resulting in a return value of ‘True’.

          Use and behaviors of the 'timeout' argument are the same as in
          *note Lock.acquire(): 366e.  Note that some of these behaviors
          of 'timeout' differ from the implemented behaviors in *note
          threading.RLock.acquire(): 107d.

      -- Metodo: release ()

          Release a lock, decrementing the recursion level.  If after
          the decrement the recursion level is zero, reset the lock to
          unlocked (not owned by any process or thread) and if any other
          processes or threads are blocked waiting for the lock to
          become unlocked, allow exactly one of them to proceed.  If
          after the decrement the recursion level is still nonzero, the
          lock remains locked and owned by the calling process or
          thread.

          Only call this method when the calling process or thread owns
          the lock.  An *note AssertionError: 8b9. is raised if this
          method is called by a process or thread other than the owner
          or if the lock is in an unlocked (unowned) state.  Note that
          the type of exception raised in this situation differs from
          the implemented behavior in *note threading.RLock.release():
          360e.

      -- Metodo: locked ()

          Return a boolean indicating whether this object is locked
          right now.

          Added in version 3.14.

 -- Classe: multiprocessing.Semaphore ([value])

     A semaphore object: a close analog of *note threading.Semaphore:
     135e.

     Instantiating this class may set the global start method.  See
     *note Global start method: 363e. for more details.

     A solitary difference from its close analog exists: its ‘acquire’
     method’s first argument is named 'block', as is consistent with
     *note Lock.acquire(): 366e.

      -- Metodo: get_value ()

          Return the current value of semaphore.

          Note that this may raise *note NotImplementedError: 36b. on
          platforms like macOS where ‘sem_getvalue()’ is not
          implemented.

      -- Metodo: locked ()

          Return a boolean indicating whether this object is locked
          right now.

          Added in version 3.14.

     Nota: On macOS, ‘sem_timedwait’ is unsupported, so calling
     ‘acquire()’ with a timeout will emulate that function’s behavior
     using a sleeping loop.

     Nota: Some of this package’s functionality requires a functioning
     shared semaphore implementation on the host operating system.
     Without one, the ‘multiprocessing.synchronize’ module will be
     disabled, and attempts to import it will result in an *note
     ImportError: 65b.  See bpo-3770(1) for additional information.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=3770


File: python.info,  Node: Shared ctypes Objects,  Next: Managers,  Prev: Synchronization primitives,  Up: Reference<3>

5.18.2.15 Shared ‘ctypes’ Objects
.................................

It is possible to create shared objects using shared memory which can be
inherited by child processes.

 -- Funzione: multiprocessing.Value (typecode_or_type, *args, lock=True)

     Return a *note ctypes: 2e. object allocated from shared memory.  By
     default the return value is actually a synchronized wrapper for the
     object.  The object itself can be accessed via the 'value'
     attribute of a *note Value: 3635.

     'typecode_or_type' determines the type of the returned object: it
     is either a ctypes type or a one character typecode of the kind
     used by the *note array: 8. module.  '*args' is passed on to the
     constructor for the type.

     If 'lock' is ‘True’ (the default) then a new recursive lock object
     is created to synchronize access to the value.  If 'lock' is a
     *note Lock: 183b. or *note RLock: 183c. object then that will be
     used to synchronize access to the value.  If 'lock' is ‘False’ then
     access to the returned object will not be automatically protected
     by a lock, so it will not necessarily be «process-safe».

     Operations like ‘+=’ which involve a read and write are not atomic.
     So if, for instance, you want to atomically increment a shared
     value it is insufficient to just do

          counter.value += 1

     Assuming the associated lock is recursive (which it is by default)
     you can instead do

          with counter.get_lock():
              counter.value += 1

     Note that 'lock' is a keyword-only argument.

 -- Funzione: multiprocessing.Array (typecode_or_type,
          size_or_initializer, *, lock=True)

     Return a ctypes array allocated from shared memory.  By default the
     return value is actually a synchronized wrapper for the array.

     'typecode_or_type' determines the type of the elements of the
     returned array: it is either a *note ctypes type: 32be. or a one
     character typecode of the kind used by the *note array: 8. module
     with the exception of ‘'w'’, which is not supported.  In addition,
     the ‘'c'’ typecode is an alias for *note ctypes.c_char: 32c1.  If
     'size_or_initializer' is an integer, then it determines the length
     of the array, and the array will be initially zeroed.  Otherwise,
     'size_or_initializer' is a sequence which is used to initialize the
     array and whose length determines the length of the array.

     If 'lock' is ‘True’ (the default) then a new lock object is created
     to synchronize access to the value.  If 'lock' is a *note Lock:
     183b. or *note RLock: 183c. object then that will be used to
     synchronize access to the value.  If 'lock' is ‘False’ then access
     to the returned object will not be automatically protected by a
     lock, so it will not necessarily be «process-safe».

     Note that 'lock' is a keyword only argument.

     Note that an array of *note ctypes.c_char: 32c1. has 'value' and
     'raw' attributes which allow one to use it to store and retrieve
     strings.

* Menu:

* The multiprocessing.sharedctypes module: The multiprocessing sharedctypes module.


File: python.info,  Node: The multiprocessing sharedctypes module,  Up: Shared ctypes Objects

5.18.2.16 The ‘multiprocessing.sharedctypes’ module
...................................................

The *note multiprocessing.sharedctypes: 9e. module provides functions
for allocating *note ctypes: 2e. objects from shared memory which can be
inherited by child processes.

     Nota: Although it is possible to store a pointer in shared memory
     remember that this will refer to a location in the address space of
     a specific process.  However, the pointer is quite likely to be
     invalid in the context of a second process and trying to
     dereference the pointer from the second process may cause a crash.

 -- Funzione: multiprocessing.sharedctypes.RawArray (typecode_or_type,
          size_or_initializer)

     Return a ctypes array allocated from shared memory.

     'typecode_or_type' determines the type of the elements of the
     returned array: it is either a ctypes type or a one character
     typecode of the kind used by the *note array: 8. module.  If
     'size_or_initializer' is an integer then it determines the length
     of the array, and the array will be initially zeroed.  Otherwise
     'size_or_initializer' is a sequence which is used to initialize the
     array and whose length determines the length of the array.

     Note that setting and getting an element is potentially non-atomic
     – use *note Array(): 3678. instead to make sure that access is
     automatically synchronized using a lock.

 -- Funzione: multiprocessing.sharedctypes.RawValue (typecode_or_type,
          *args)

     Return a ctypes object allocated from shared memory.

     'typecode_or_type' determines the type of the returned object: it
     is either a ctypes type or a one character typecode of the kind
     used by the *note array: 8. module.  '*args' is passed on to the
     constructor for the type.

     Note that setting and getting the value is potentially non-atomic –
     use *note Value(): 367a. instead to make sure that access is
     automatically synchronized using a lock.

     Note that an array of *note ctypes.c_char: 32c1. has ‘value’ and
     ‘raw’ attributes which allow one to use it to store and retrieve
     strings – see documentation for *note ctypes: 2e.

 -- Funzione: multiprocessing.sharedctypes.Array (typecode_or_type,
          size_or_initializer, *, lock=True, ctx=None)

     The same as *note RawArray(): 3677. except that depending on the
     value of 'lock' a process-safe synchronization wrapper may be
     returned instead of a raw ctypes array.

     If 'lock' is ‘True’ (the default) then a new lock object is created
     to synchronize access to the value.  If 'lock' is a *note Lock:
     183b. or *note RLock: 183c. object then that will be used to
     synchronize access to the value.  If 'lock' is ‘False’ then access
     to the returned object will not be automatically protected by a
     lock, so it will not necessarily be «process-safe».

     'ctx' is a context object, or ‘None’ (use the current context).  If
     ‘None’, calling this may set the global start method.  See *note
     Global start method: 363e. for more details.

     Note that 'lock' and 'ctx' are keyword-only parameters.

 -- Funzione: multiprocessing.sharedctypes.Value (typecode_or_type,
          *args, lock=True, ctx=None)

     The same as *note RawValue(): 3679. except that depending on the
     value of 'lock' a process-safe synchronization wrapper may be
     returned instead of a raw ctypes object.

     If 'lock' is ‘True’ (the default) then a new lock object is created
     to synchronize access to the value.  If 'lock' is a *note Lock:
     183b. or *note RLock: 183c. object then that will be used to
     synchronize access to the value.  If 'lock' is ‘False’ then access
     to the returned object will not be automatically protected by a
     lock, so it will not necessarily be «process-safe».

     'ctx' is a context object, or ‘None’ (use the current context).  If
     ‘None’, calling this may set the global start method.  See *note
     Global start method: 363e. for more details.

     Note that 'lock' and 'ctx' are keyword-only parameters.

 -- Funzione: multiprocessing.sharedctypes.copy (obj)

     Return a ctypes object allocated from shared memory which is a copy
     of the ctypes object 'obj'.

 -- Funzione: multiprocessing.sharedctypes.synchronized (obj, lock=None,
          ctx=None)

     Return a process-safe wrapper object for a ctypes object which uses
     'lock' to synchronize access.  If 'lock' is ‘None’ (the default)
     then a *note multiprocessing.RLock: 183c. object is created
     automatically.

     'ctx' is a context object, or ‘None’ (use the current context).  If
     ‘None’, calling this may set the global start method.  See *note
     Global start method: 363e. for more details.

     A synchronized wrapper will have two methods in addition to those
     of the object it wraps: ‘get_obj()’ returns the wrapped object and
     ‘get_lock()’ returns the lock object used for synchronization.

     Note that accessing the ctypes object through the wrapper can be a
     lot slower than accessing the raw ctypes object.

     Cambiato nella versione 3.5: Synchronized objects support the *note
     context manager: 1e1. protocol.

The table below compares the syntax for creating shared ctypes objects
from shared memory with the normal ctypes syntax.  (In the table
‘MyStruct’ is some subclass of *note ctypes.Structure: 1e5.)

ctypes                   sharedctypes using type        sharedctypes using typecode
                                                        
----------------------------------------------------------------------------------------
                                                        
c_double(2.4)            RawValue(c_double, 2.4)        RawValue(“d”, 2.4)
                                                        
                                                        
MyStruct(4, 6)           RawValue(MyStruct, 4, 6)
                         
                                                        
(c_short * 7)()          RawArray(c_short, 7)           RawArray(“h”, 7)
                                                        
                                                        
(c_int * 3)(9, 2, 8)     RawArray(c_int, (9, 2, 8))     RawArray(“i”, (9, 2, 8))
                                                        

Below is an example where a number of ctypes objects are modified by a
child process:

     from multiprocessing import Process, Lock
     from multiprocessing.sharedctypes import Value, Array
     from ctypes import Structure, c_double

     class Point(Structure):
         _fields_ = [('x', c_double), ('y', c_double)]

     def modify(n, x, s, A):
         n.value **= 2
         x.value **= 2
         s.value = s.value.upper()
         for a in A:
             a.x **= 2
             a.y **= 2

     if __name__ == '__main__':
         lock = Lock()

         n = Value('i', 7)
         x = Value(c_double, 1.0/3.0, lock=False)
         s = Array('c', b'hello world', lock=lock)
         A = Array(Point, [(1.875,-6.25), (-5.75,2.0), (2.375,9.5)], lock=lock)

         p = Process(target=modify, args=(n, x, s, A))
         p.start()
         p.join()

         print(n.value)
         print(x.value)
         print(s.value)
         print([(a.x, a.y) for a in A])

The results printed are

     49
     0.1111111111111111
     HELLO WORLD
     [(3.515625, 39.0625), (33.0625, 4.0), (5.640625, 90.25)]


File: python.info,  Node: Managers,  Next: Proxy Objects,  Prev: Shared ctypes Objects,  Up: Reference<3>

5.18.2.17 Managers
..................

Managers provide a way to create data which can be shared between
different processes, including sharing over a network between processes
running on different machines.  A manager object controls a server
process which manages 'shared objects'.  Other processes can access the
shared objects by using proxies.

 -- Funzione: multiprocessing.Manager ()

     Returns a started *note SyncManager: 187c. object which can be used
     for sharing objects between processes.  The returned manager object
     corresponds to a spawned child process and has methods which will
     create shared objects and return corresponding proxies.

Manager processes will be shutdown as soon as they are garbage collected
or their parent process exits.  The manager classes are defined in the
*note multiprocessing.managers: 9b. module:

 -- Classe: multiprocessing.managers.BaseManager (address=None,
          authkey=None, serializer='pickle', ctx=None, *,
          shutdown_timeout=1.0)

     Create a BaseManager object.

     Once created one should call *note start(): 367e. or
     ‘get_server().serve_forever()’ to ensure that the manager object
     refers to a started manager process.

     'address' is the address on which the manager process listens for
     new connections.  If 'address' is ‘None’ then an arbitrary one is
     chosen.

     'authkey' is the authentication key which will be used to check the
     validity of incoming connections to the server process.  If
     'authkey' is ‘None’ then ‘current_process().authkey’ is used.
     Otherwise 'authkey' is used and it must be a byte string.

     'serializer' must be ‘'pickle'’ (use *note pickle: ab.
     serialization) or ‘'xmlrpclib'’ (use *note xmlrpc.client: 134.
     serialization).

     'ctx' is a context object, or ‘None’ (use the current context).  If
     ‘None’, calling this may set the global start method.  See *note
     Global start method: 363e. for more details.

     'shutdown_timeout' is a timeout in seconds used to wait until the
     process used by the manager completes in the *note shutdown():
     367f. method.  If the shutdown times out, the process is
     terminated.  If terminating the process also times out, the process
     is killed.

     Cambiato nella versione 3.11: Added the 'shutdown_timeout'
     parameter.

      -- Metodo: start ([initializer[, initargs]])

          Start a subprocess to start the manager.  If 'initializer' is
          not ‘None’ then the subprocess will call
          ‘initializer(*initargs)’ when it starts.

      -- Metodo: get_server ()

          Returns a ‘Server’ object which represents the actual server
          under the control of the Manager.  The ‘Server’ object
          supports the ‘serve_forever()’ method:

               >>> from multiprocessing.managers import BaseManager
               >>> manager = BaseManager(address=('', 50000), authkey=b'abc')
               >>> server = manager.get_server()
               >>> server.serve_forever()

          ‘Server’ additionally has an *note address: 3681. attribute.

      -- Metodo: connect ()

          Connect a local manager object to a remote manager process:

               >>> from multiprocessing.managers import BaseManager
               >>> m = BaseManager(address=('127.0.0.1', 50000), authkey=b'abc')
               >>> m.connect()

      -- Metodo: shutdown ()

          Stop the process used by the manager.  This is only available
          if *note start(): 367e. has been used to start the server
          process.

          This can be called multiple times.

      -- Metodo: register (typeid[, callable[, proxytype[, exposed[,
               method_to_typeid[, create_method]]]]])

          A classmethod which can be used for registering a type or
          callable with the manager class.

          'typeid' is a «type identifier» which is used to identify a
          particular type of shared object.  This must be a string.

          'callable' is a callable used for creating objects for this
          type identifier.  If a manager instance will be connected to
          the server using the *note connect(): 3682. method, or if the
          'create_method' argument is ‘False’ then this can be left as
          ‘None’.

          'proxytype' is a subclass of *note BaseProxy: 3684. which is
          used to create proxies for shared objects with this 'typeid'.
          If ‘None’ then a proxy class is created automatically.

          'exposed' is used to specify a sequence of method names which
          proxies for this typeid should be allowed to access using
          *note BaseProxy._callmethod(): 3685.  (If 'exposed' is ‘None’
          then ‘proxytype._exposed_’ is used instead if it exists.)  In
          the case where no exposed list is specified, all «public
          methods» of the shared object will be accessible.  (Here a
          «public method» means any attribute which has a *note
          __call__(): 77b. method and whose name does not begin with
          ‘'_'’.)

          'method_to_typeid' is a mapping used to specify the return
          type of those exposed methods which should return a proxy.  It
          maps method names to typeid strings.  (If 'method_to_typeid'
          is ‘None’ then ‘proxytype._method_to_typeid_’ is used instead
          if it exists.)  If a method’s name is not a key of this
          mapping or if the mapping is ‘None’ then the object returned
          by the method will be copied by value.

          'create_method' determines whether a method should be created
          with name 'typeid' which can be used to tell the server
          process to create a new shared object and return a proxy for
          it.  By default it is ‘True’.

     *note BaseManager: 367d. instances also have one read-only
     property:

      -- Attributo: address

          The address used by the manager.

     Cambiato nella versione 3.3: Manager objects support the context
     management protocol – see *note Tipi di gestori di contesti: 23f0.
     *note __enter__(): 268b. starts the server process (if it has not
     already started) and then returns the manager object.  *note
     __exit__(): 268c. calls *note shutdown(): 367f.

     In previous versions *note __enter__(): 268b. did not start the
     manager’s server process if it was not already started.

 -- Classe: multiprocessing.managers.SyncManager

     A subclass of *note BaseManager: 367d. which can be used for the
     synchronization of processes.  Objects of this type are returned by
     *note multiprocessing.Manager(): 250.

     Its methods create and return *note Proxy Objects: 24c. for a
     number of commonly used data types to be synchronized across
     processes.  This notably includes shared lists and dictionaries.

      -- Metodo: Barrier (parties[, action[, timeout]])

          Create a shared *note threading.Barrier: 13eb. object and
          return a proxy for it.

          Added in version 3.3.

      -- Metodo: BoundedSemaphore ([value])

          Create a shared *note threading.BoundedSemaphore: 135f. object
          and return a proxy for it.

      -- Metodo: Condition ([lock])

          Create a shared *note threading.Condition: 135d. object and
          return a proxy for it.

          If 'lock' is supplied then it should be a proxy for a *note
          threading.Lock: 19dc. or *note threading.RLock: 32e. object.

          Cambiato nella versione 3.3: The *note wait_for(): 3613.
          method was added.

      -- Metodo: Event ()

          Create a shared *note threading.Event: 1360. object and return
          a proxy for it.

      -- Metodo: Lock ()

          Create a shared *note threading.Lock: 19dc. object and return
          a proxy for it.

      -- Metodo: Namespace ()

          Create a shared *note Namespace: 3637. object and return a
          proxy for it.

      -- Metodo: Queue ([maxsize])

          Create a shared *note queue.Queue: 159c. object and return a
          proxy for it.

      -- Metodo: RLock ()

          Create a shared *note threading.RLock: 32e. object and return
          a proxy for it.

      -- Metodo: Semaphore ([value])

          Create a shared *note threading.Semaphore: 135e. object and
          return a proxy for it.

      -- Metodo: Array (typecode, sequence)

          Create an array and return a proxy for it.

      -- Metodo: Value (typecode, value)

          Create an object with a writable ‘value’ attribute and return
          a proxy for it.

      -- Metodo: dict ()

      -- Metodo: dict (mapping)

      -- Metodo: dict (sequence)

          Create a shared *note dict: 183. object and return a proxy for
          it.

      -- Metodo: list ()

      -- Metodo: list (sequence)

          Create a shared *note list: 24d. object and return a proxy for
          it.

      -- Metodo: set ()

      -- Metodo: set (sequence)

      -- Metodo: set (mapping)

          Create a shared *note set: 184. object and return a proxy for
          it.

          Added in version 3.14: *note set: 184. support was added.

     Cambiato nella versione 3.6: Shared objects are capable of being
     nested.  For example, a shared container object such as a shared
     list can contain other shared objects which will all be managed and
     synchronized by the *note SyncManager: 187c.

 -- Classe: multiprocessing.managers.Namespace

     A type that can register with *note SyncManager: 187c.

     A namespace object has no public methods, but does have writable
     attributes.  Its representation shows the values of its attributes.

     However, when using a proxy for a namespace object, an attribute
     beginning with ‘'_'’ will be an attribute of the proxy and not an
     attribute of the referent:

          >>> mp_context = multiprocessing.get_context('spawn')
          >>> manager = mp_context.Manager()
          >>> Global = manager.Namespace()
          >>> Global.x = 10
          >>> Global.y = 'hello'
          >>> Global._z = 12.3    # this is an attribute of the proxy
          >>> print(Global)
          Namespace(x=10, y='hello')

* Menu:

* Customized managers::
* Using a remote manager::


File: python.info,  Node: Customized managers,  Next: Using a remote manager,  Up: Managers

5.18.2.18 Customized managers
.............................

To create one’s own manager, one creates a subclass of *note
BaseManager: 367d. and uses the *note register(): 3683. classmethod to
register new types or callables with the manager class.  For example:

     from multiprocessing.managers import BaseManager

     class MathsClass:
         def add(self, x, y):
             return x + y
         def mul(self, x, y):
             return x * y

     class MyManager(BaseManager):
         pass

     MyManager.register('Maths', MathsClass)

     if __name__ == '__main__':
         with MyManager() as manager:
             maths = manager.Maths()
             print(maths.add(4, 3))         # prints 7
             print(maths.mul(7, 8))         # prints 56


File: python.info,  Node: Using a remote manager,  Prev: Customized managers,  Up: Managers

5.18.2.19 Using a remote manager
................................

It is possible to run a manager server on one machine and have clients
use it from other machines (assuming that the firewalls involved allow
it).

Running the following commands creates a server for a single shared
queue which remote clients can access:

     >>> from multiprocessing.managers import BaseManager
     >>> from queue import Queue
     >>> queue = Queue()
     >>> class QueueManager(BaseManager): pass
     >>> QueueManager.register('get_queue', callable=lambda:queue)
     >>> m = QueueManager(address=('', 50000), authkey=b'abracadabra')
     >>> s = m.get_server()
     >>> s.serve_forever()

One client can access the server as follows:

     >>> from multiprocessing.managers import BaseManager
     >>> class QueueManager(BaseManager): pass
     >>> QueueManager.register('get_queue')
     >>> m = QueueManager(address=('foo.bar.org', 50000), authkey=b'abracadabra')
     >>> m.connect()
     >>> queue = m.get_queue()
     >>> queue.put('hello')

Another client can also use it:

     >>> from multiprocessing.managers import BaseManager
     >>> class QueueManager(BaseManager): pass
     >>> QueueManager.register('get_queue')
     >>> m = QueueManager(address=('foo.bar.org', 50000), authkey=b'abracadabra')
     >>> m.connect()
     >>> queue = m.get_queue()
     >>> queue.get()
     'hello'

Local processes can also access that queue, using the code from above on
the client to access it remotely:

     >>> from multiprocessing import Process, Queue
     >>> from multiprocessing.managers import BaseManager
     >>> class Worker(Process):
     ...     def __init__(self, q):
     ...         self.q = q
     ...         super().__init__()
     ...     def run(self):
     ...         self.q.put('local hello')
     ...
     >>> queue = Queue()
     >>> w = Worker(queue)
     >>> w.start()
     >>> class QueueManager(BaseManager): pass
     ...
     >>> QueueManager.register('get_queue', callable=lambda: queue)
     >>> m = QueueManager(address=('', 50000), authkey=b'abracadabra')
     >>> s = m.get_server()
     >>> s.serve_forever()


File: python.info,  Node: Proxy Objects,  Next: Process Pools,  Prev: Managers,  Up: Reference<3>

5.18.2.20 Proxy Objects
.......................

A proxy is an object which 'refers' to a shared object which lives
(presumably) in a different process.  The shared object is said to be
the 'referent' of the proxy.  Multiple proxy objects may have the same
referent.

A proxy object has methods which invoke corresponding methods of its
referent (although not every method of the referent will necessarily be
available through the proxy).  In this way, a proxy can be used just
like its referent can:

     >>> mp_context = multiprocessing.get_context('spawn')
     >>> manager = mp_context.Manager()
     >>> l = manager.list([i*i for i in range(10)])
     >>> print(l)
     [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
     >>> print(repr(l))
     <ListProxy object, typeid 'list' at 0x...>
     >>> l[4]
     16
     >>> l[2:5]
     [4, 9, 16]

Notice that applying *note str(): 169. to a proxy will return the
representation of the referent, whereas applying *note repr(): 1c1. will
return the representation of the proxy.

An important feature of proxy objects is that they are picklable so they
can be passed between processes.  As such, a referent can contain *note
Proxy Objects: 24c.  This permits nesting of these managed lists, dicts,
and other *note Proxy Objects: 24c.:

     >>> a = manager.list()
     >>> b = manager.list()
     >>> a.append(b)         # referent of a now contains referent of b
     >>> print(a, b)
     [<ListProxy object, typeid 'list' at ...>] []
     >>> b.append('hello')
     >>> print(a[0], b)
     ['hello'] ['hello']

Similarly, dict and list proxies may be nested inside one another:

     >>> l_outer = manager.list([ manager.dict() for i in range(2) ])
     >>> d_first_inner = l_outer[0]
     >>> d_first_inner['a'] = 1
     >>> d_first_inner['b'] = 2
     >>> l_outer[1]['c'] = 3
     >>> l_outer[1]['z'] = 26
     >>> print(l_outer[0])
     {'a': 1, 'b': 2}
     >>> print(l_outer[1])
     {'c': 3, 'z': 26}

If standard (non-proxy) *note list: 24d. or *note dict: 183. objects are
contained in a referent, modifications to those mutable values will not
be propagated through the manager because the proxy has no way of
knowing when the values contained within are modified.  However, storing
a value in a container proxy (which triggers a ‘__setitem__’ on the
proxy object) does propagate through the manager and so to effectively
modify such an item, one could re-assign the modified value to the
container proxy:

     # create a list proxy and append a mutable object (a dictionary)
     lproxy = manager.list()
     lproxy.append({})
     # now mutate the dictionary
     d = lproxy[0]
     d['a'] = 1
     d['b'] = 2
     # at this point, the changes to d are not yet synced, but by
     # updating the dictionary, the proxy is notified of the change
     lproxy[0] = d

This approach is perhaps less convenient than employing nested *note
Proxy Objects: 24c. for most use cases but also demonstrates a level of
control over the synchronization.

     Nota: The proxy types in *note multiprocessing: 98. do nothing to
     support comparisons by value.  So, for instance, we have:

          >>> manager.list([1,2,3]) == [1,2,3]
          False

     One should just use a copy of the referent instead when making
     comparisons.

 -- Classe: multiprocessing.managers.BaseProxy

     Proxy objects are instances of subclasses of *note BaseProxy: 3684.

      -- Metodo: _callmethod (methodname[, args[, kwds]])

          Call and return the result of a method of the proxy’s
          referent.

          If ‘proxy’ is a proxy whose referent is ‘obj’ then the
          expression

               proxy._callmethod(methodname, args, kwds)

          will evaluate the expression

               getattr(obj, methodname)(*args, **kwds)

          in the manager’s process.

          The returned value will be a copy of the result of the call or
          a proxy to a new shared object – see documentation for the
          'method_to_typeid' argument of *note BaseManager.register():
          3683.

          If an exception is raised by the call, then is re-raised by
          *note _callmethod(): 3685.  If some other exception is raised
          in the manager’s process then this is converted into a
          ‘RemoteError’ exception and is raised by *note _callmethod():
          3685.

          Note in particular that an exception will be raised if
          'methodname' has not been 'exposed'.

          An example of the usage of *note _callmethod(): 3685.:

               >>> l = manager.list(range(10))
               >>> l._callmethod('__len__')
               10
               >>> l._callmethod('__getitem__', (slice(2, 7),)) # equivalent to l[2:7]
               [2, 3, 4, 5, 6]
               >>> l._callmethod('__getitem__', (20,))          # equivalent to l[20]
               Traceback (most recent call last):
               ...
               IndexError: list index out of range

      -- Metodo: _getvalue ()

          Return a copy of the referent.

          If the referent is unpicklable then this will raise an
          exception.

      -- Metodo: __repr__ ()

          Return a representation of the proxy object.

      -- Metodo: __str__ ()

          Return the representation of the referent.

* Menu:

* Cleanup: Cleanup<2>.


File: python.info,  Node: Cleanup<2>,  Up: Proxy Objects

5.18.2.21 Cleanup
.................

A proxy object uses a weakref callback so that when it gets garbage
collected it deregisters itself from the manager which owns its
referent.

A shared object gets deleted from the manager process when there are no
longer any proxies referring to it.


File: python.info,  Node: Process Pools,  Next: Listeners and Clients,  Prev: Proxy Objects,  Up: Reference<3>

5.18.2.22 Process Pools
.......................

One can create a pool of processes which will carry out tasks submitted
to it with the *note Pool: 116d. class.

 -- Classe: multiprocessing.pool.Pool ([processes[, initializer[,
          initargs[, maxtasksperchild[, context]]]]])

     A process pool object which controls a pool of worker processes to
     which jobs can be submitted.  It supports asynchronous results with
     timeouts and callbacks and has a parallel map implementation.

     'processes' is the number of worker processes to use.  If
     'processes' is ‘None’ then the number returned by *note
     os.process_cpu_count(): 4db. is used.

     If 'initializer' is not ‘None’ then each worker process will call
     ‘initializer(*initargs)’ when it starts.

     'maxtasksperchild' is the number of tasks a worker process can
     complete before it will exit and be replaced with a fresh worker
     process, to enable unused resources to be freed.  The default
     'maxtasksperchild' is ‘None’, which means worker processes will
     live as long as the pool.

     'context' can be used to specify the context used for starting the
     worker processes.  Usually a pool is created using the function
     ‘multiprocessing.Pool()’ or the *note Pool(): 116d. method of a
     context object.  In both cases 'context' is set appropriately.  If
     ‘None’, calling this function will have the side effect of setting
     the current global start method if it has not been set already.
     See the ‘get_context()’ function.

     Note that the methods of the pool object should only be called by
     the process which created the pool.

          Avvertimento: *note multiprocessing.pool: 9c. objects have
          internal resources that need to be properly managed (like any
          other resource) by using the pool as a context manager or by
          calling *note close(): 3697. and *note terminate(): 3698.
          manually.  Failure to do this can lead to the process hanging
          on finalization.

          Note that it is 'not correct' to rely on the garbage collector
          to destroy the pool as CPython does not assure that the
          finalizer of the pool will be called (see *note
          object.__del__(): 11ff. for more information).

     Cambiato nella versione 3.2: Added the 'maxtasksperchild'
     parameter.

     Cambiato nella versione 3.4: Added the 'context' parameter.

     Cambiato nella versione 3.13: 'processes' uses *note
     os.process_cpu_count(): 4db. by default, instead of *note
     os.cpu_count(): 4dc.

          Nota: Worker processes within a *note Pool: 116d. typically
          live for the complete duration of the Pool’s work queue.  A
          frequent pattern found in other systems (such as Apache,
          mod_wsgi, etc) to free resources held by workers is to allow a
          worker within a pool to complete only a set amount of work
          before being exiting, being cleaned up and a new process
          spawned to replace the old one.  The 'maxtasksperchild'
          argument to the *note Pool: 116d. exposes this ability to the
          end user.

      -- Metodo: apply (func[, args[, kwds]])

          Call 'func' with arguments 'args' and keyword arguments
          'kwds'.  It blocks until the result is ready.  Given this
          blocks, *note apply_async(): 159e. is better suited for
          performing work in parallel.  Additionally, 'func' is only
          executed in one of the workers of the pool.

      -- Metodo: apply_async (func[, args[, kwds[, callback[,
               error_callback]]]])

          A variant of the *note apply(): 159d. method which returns a
          *note AsyncResult: 3699. object.

          If 'callback' is specified then it should be a callable which
          accepts a single argument.  When the result becomes ready
          'callback' is applied to it, that is unless the call failed,
          in which case the 'error_callback' is applied instead.

          If 'error_callback' is specified then it should be a callable
          which accepts a single argument.  If the target function
          fails, then the 'error_callback' is called with the exception
          instance.

          Callbacks should complete immediately since otherwise the
          thread which handles the results will get blocked.

      -- Metodo: map (func, iterable[, chunksize])

          A parallel equivalent of the *note map(): 19f. built-in
          function (it supports only one 'iterable' argument though, for
          multiple iterables see *note starmap(): 12ea.).  It blocks
          until the result is ready.

          This method chops the iterable into a number of chunks which
          it submits to the process pool as separate tasks.  The
          (approximate) size of these chunks can be specified by setting
          'chunksize' to a positive integer.

          Note that it may cause high memory usage for very long
          iterables.  Consider using *note imap(): 369a. or *note
          imap_unordered(): 369b. with explicit 'chunksize' option for
          better efficiency.

      -- Metodo: map_async (func, iterable[, chunksize[, callback[,
               error_callback]]])

          A variant of the *note map(): 12ed. method which returns a
          *note AsyncResult: 3699. object.

          If 'callback' is specified then it should be a callable which
          accepts a single argument.  When the result becomes ready
          'callback' is applied to it, that is unless the call failed,
          in which case the 'error_callback' is applied instead.

          If 'error_callback' is specified then it should be a callable
          which accepts a single argument.  If the target function
          fails, then the 'error_callback' is called with the exception
          instance.

          Callbacks should complete immediately since otherwise the
          thread which handles the results will get blocked.

      -- Metodo: imap (func, iterable[, chunksize])

          A lazier version of *note map(): 12ed.

          The 'chunksize' argument is the same as the one used by the
          *note map(): 12ed. method.  For very long iterables using a
          large value for 'chunksize' can make the job complete 'much'
          faster than using the default value of ‘1’.

          Also if 'chunksize' is ‘1’ then the ‘next()’ method of the
          iterator returned by the *note imap(): 369a. method has an
          optional 'timeout' parameter: ‘next(timeout)’ will raise *note
          multiprocessing.TimeoutError: 364b. if the result cannot be
          returned within 'timeout' seconds.

      -- Metodo: imap_unordered (func, iterable[, chunksize])

          The same as *note imap(): 369a. except that the ordering of
          the results from the returned iterator should be considered
          arbitrary.  (Only when there is only one worker process is the
          order guaranteed to be «correct».)

      -- Metodo: starmap (func, iterable[, chunksize])

          Like *note map(): 12ed. except that the elements of the
          'iterable' are expected to be iterables that are unpacked as
          arguments.

          Hence an 'iterable' of ‘[(1,2), (3, 4)]’ results in
          ‘[func(1,2), func(3,4)]’.

          Added in version 3.3.

      -- Metodo: starmap_async (func, iterable[, chunksize[, callback[,
               error_callback]]])

          A combination of *note starmap(): 12ea. and *note map_async():
          12ee. that iterates over 'iterable' of iterables and calls
          'func' with the iterables unpacked.  Returns a result object.

          Added in version 3.3.

      -- Metodo: close ()

          Prevents any more tasks from being submitted to the pool.
          Once all the tasks have been completed the worker processes
          will exit.

      -- Metodo: terminate ()

          Stops the worker processes immediately without completing
          outstanding work.  When the pool object is garbage collected
          *note terminate(): 3698. will be called immediately.

      -- Metodo: join ()

          Wait for the worker processes to exit.  One must call *note
          close(): 3697. or *note terminate(): 3698. before using *note
          join(): 369c.

     Cambiato nella versione 3.3: Pool objects now support the context
     management protocol – see *note Tipi di gestori di contesti: 23f0.
     *note __enter__(): 268b. returns the pool object, and *note
     __exit__(): 268c. calls *note terminate(): 3698.

 -- Classe: multiprocessing.pool.AsyncResult

     The class of the result returned by *note Pool.apply_async(): 159e.
     and *note Pool.map_async(): 12ee.

      -- Metodo: get ([timeout])

          Return the result when it arrives.  If 'timeout' is not ‘None’
          and the result does not arrive within 'timeout' seconds then
          *note multiprocessing.TimeoutError: 364b. is raised.  If the
          remote call raised an exception then that exception will be
          reraised by *note get(): 369d.

      -- Metodo: wait ([timeout])

          Wait until the result is available or until 'timeout' seconds
          pass.

      -- Metodo: ready ()

          Return whether the call has completed.

      -- Metodo: successful ()

          Return whether the call completed without raising an
          exception.  Will raise *note ValueError: 2ec. if the result is
          not ready.

          Cambiato nella versione 3.7: If the result is not ready, *note
          ValueError: 2ec. is raised instead of *note AssertionError:
          8b9.

The following example demonstrates the use of a pool:

     from multiprocessing import Pool
     import time

     def f(x):
         return x*x

     if __name__ == '__main__':
         with Pool(processes=4) as pool:         # start 4 worker processes
             result = pool.apply_async(f, (10,)) # evaluate "f(10)" asynchronously in a single process
             print(result.get(timeout=1))        # prints "100" unless your computer is *very* slow

             print(pool.map(f, range(10)))       # prints "[0, 1, 4,..., 81]"

             it = pool.imap(f, range(10))
             print(next(it))                     # prints "0"
             print(next(it))                     # prints "1"
             print(it.next(timeout=1))           # prints "4" unless your computer is *very* slow

             result = pool.apply_async(time.sleep, (10,))
             print(result.get(timeout=1))        # raises multiprocessing.TimeoutError


File: python.info,  Node: Listeners and Clients,  Next: Authentication keys,  Prev: Process Pools,  Up: Reference<3>

5.18.2.23 Listeners and Clients
...............................

Usually message passing between processes is done using queues or by
using *note Connection: 12e8. objects returned by *note Pipe(): 3632.

However, the *note multiprocessing.connection: 99. module allows some
extra flexibility.  It basically gives a high level message oriented API
for dealing with sockets or Windows named pipes.  It also has support
for 'digest authentication' using the *note hmac: 6e. module, and for
polling multiple connections at the same time.

 -- Funzione: multiprocessing.connection.deliver_challenge (connection,
          authkey)

     Send a randomly generated message to the other end of the
     connection and wait for a reply.

     If the reply matches the digest of the message using 'authkey' as
     the key then a welcome message is sent to the other end of the
     connection.  Otherwise *note AuthenticationError: 364a. is raised.

 -- Funzione: multiprocessing.connection.answer_challenge (connection,
          authkey)

     Receive a message, calculate the digest of the message using
     'authkey' as the key, and then send the digest back.

     If a welcome message is not received, then *note
     AuthenticationError: 364a. is raised.

 -- Funzione: multiprocessing.connection.Client (address[, family[,
          authkey]])

     Attempt to set up a connection to the listener which is using
     address 'address', returning a *note Connection: 12e8.

     The type of the connection is determined by 'family' argument, but
     this can generally be omitted since it can usually be inferred from
     the format of 'address'.  (See *note Address Formats: 36a5.)

     If 'authkey' is given and not ‘None’, it should be a byte string
     and will be used as the secret key for an HMAC-based authentication
     challenge.  No authentication is done if 'authkey' is ‘None’.
     *note AuthenticationError: 364a. is raised if authentication fails.
     See *note Authentication keys: 3647.

 -- Classe: multiprocessing.connection.Listener ([address[, family[,
          backlog[, authkey]]]])

     A wrapper for a bound socket or Windows named pipe which is
     “listening” for connections.

     'address' is the address to be used by the bound socket or named
     pipe of the listener object.

          Nota: If an address of “0.0.0.0” is used, the address will not
          be a connectable end point on Windows.  If you require a
          connectable end-point, you should use “127.0.0.1”.

     'family' is the type of socket (or named pipe) to use.  This can be
     one of the strings ‘'AF_INET'’ (for a TCP socket), ‘'AF_UNIX'’ (for
     a Unix domain socket) or ‘'AF_PIPE'’ (for a Windows named pipe).
     Of these only the first is guaranteed to be available.  If 'family'
     is ‘None’ then the family is inferred from the format of 'address'.
     If 'address' is also ‘None’ then a default is chosen.  This default
     is the family which is assumed to be the fastest available.  See
     *note Address Formats: 36a5.  Note that if 'family' is ‘'AF_UNIX'’
     and address is ‘None’ then the socket will be created in a private
     temporary directory created using *note tempfile.mkstemp(): 2cb0.

     If the listener object uses a socket then 'backlog' (1 by default)
     is passed to the *note listen(): 1060. method of the socket once it
     has been bound.

     If 'authkey' is given and not ‘None’, it should be a byte string
     and will be used as the secret key for an HMAC-based authentication
     challenge.  No authentication is done if 'authkey' is ‘None’.
     *note AuthenticationError: 364a. is raised if authentication fails.
     See *note Authentication keys: 3647.

      -- Metodo: accept ()

          Accept a connection on the bound socket or named pipe of the
          listener object and return a *note Connection: 12e8. object.
          If authentication is attempted and fails, then *note
          AuthenticationError: 364a. is raised.

      -- Metodo: close ()

          Close the bound socket or named pipe of the listener object.
          This is called automatically when the listener is garbage
          collected.  However it is advisable to call it explicitly.

     Listener objects have the following read-only properties:

      -- Attributo: address

          The address which is being used by the Listener object.

      -- Attributo: last_accepted

          The address from which the last accepted connection came.  If
          this is unavailable then it is ‘None’.

     Cambiato nella versione 3.3: Listener objects now support the
     context management protocol – see *note Tipi di gestori di
     contesti: 23f0.  *note __enter__(): 268b. returns the listener
     object, and *note __exit__(): 268c. calls *note close(): 36a6.

 -- Funzione: multiprocessing.connection.wait (object_list,
          timeout=None)

     Wait till an object in 'object_list' is ready.  Returns the list of
     those objects in 'object_list' which are ready.  If 'timeout' is a
     float then the call blocks for at most that many seconds.  If
     'timeout' is ‘None’ then it will block for an unlimited period.  A
     negative timeout is equivalent to a zero timeout.

     For both POSIX and Windows, an object can appear in 'object_list'
     if it is

        * a readable *note Connection: 12e8. object;

        * a connected and readable *note socket.socket: fa3. object; or

        * the *note sentinel: 12e9. attribute of a *note Process: 252.
          object.

     A connection or socket object is ready when there is data available
     to be read from it, or the other end has been closed.

     'POSIX': ‘wait(object_list, timeout)’ almost equivalent
     ‘select.select(object_list, [], [], timeout)’.  The difference is
     that, if *note select.select(): fa2. is interrupted by a signal, it
     can raise *note OSError: 2c0. with an error number of ‘EINTR’,
     whereas *note wait(): 12e7. will not.

     'Windows': An item in 'object_list' must either be an integer
     handle which is waitable (according to the definition used by the
     documentation of the Win32 function ‘WaitForMultipleObjects()’) or
     it can be an object with a *note fileno(): 1795. method which
     returns a socket handle or pipe handle.  (Note that pipe handles
     and socket handles are 'not' waitable handles.)

     Added in version 3.3.

'Examples'

The following server code creates a listener which uses ‘'secret
password'’ as an authentication key.  It then waits for a connection and
sends some data to the client:

     from multiprocessing.connection import Listener
     from array import array

     address = ('localhost', 6000)     # family is deduced to be 'AF_INET'

     with Listener(address, authkey=b'secret password') as listener:
         with listener.accept() as conn:
             print('connection accepted from', listener.last_accepted)

             conn.send([2.25, None, 'junk', float])

             conn.send_bytes(b'hello')

             conn.send_bytes(array('i', [42, 1729]))

The following code connects to the server and receives some data from
the server:

     from multiprocessing.connection import Client
     from array import array

     address = ('localhost', 6000)

     with Client(address, authkey=b'secret password') as conn:
         print(conn.recv())                  # => [2.25, None, 'junk', float]

         print(conn.recv_bytes())            # => 'hello'

         arr = array('i', [0, 0, 0, 0, 0])
         print(conn.recv_bytes_into(arr))    # => 8
         print(arr)                          # => array('i', [42, 1729, 0, 0, 0])

The following code uses *note wait(): 12e7. to wait for messages from
multiple processes at once:

     from multiprocessing import Process, Pipe, current_process
     from multiprocessing.connection import wait

     def foo(w):
         for i in range(10):
             w.send((i, current_process().name))
         w.close()

     if __name__ == '__main__':
         readers = []

         for i in range(4):
             r, w = Pipe(duplex=False)
             readers.append(r)
             p = Process(target=foo, args=(w,))
             p.start()
             # We close the writable end of the pipe now to be sure that
             # p is the only process which owns a handle for it.  This
             # ensures that when p closes its handle for the writable end,
             # wait() will promptly report the readable end as being ready.
             w.close()

         while readers:
             for r in wait(readers):
                 try:
                     msg = r.recv()
                 except EOFError:
                     readers.remove(r)
                 else:
                     print(msg)

* Menu:

* Address Formats::


File: python.info,  Node: Address Formats,  Up: Listeners and Clients

5.18.2.24 Address Formats
.........................

   * An ‘'AF_INET'’ address is a tuple of the form ‘(hostname, port)’
     where 'hostname' is a string and 'port' is an integer.

   * An ‘'AF_UNIX'’ address is a string representing a filename on the
     filesystem.

   * An ‘'AF_PIPE'’ address is a string of the form
     ‘r'\\.\pipe\PIPENAME'’.  To use *note Client(): 36a4. to connect to
     a named pipe on a remote computer called 'ServerName' one should
     use an address of the form ‘r'\\SERVERNAME\pipe\PIPENAME'’ instead.

Note that any string beginning with two backslashes is assumed by
default to be an ‘'AF_PIPE'’ address rather than an ‘'AF_UNIX'’ address.


File: python.info,  Node: Authentication keys,  Next: Logging<2>,  Prev: Listeners and Clients,  Up: Reference<3>

5.18.2.25 Authentication keys
.............................

When one uses *note Connection.recv: 3665, the data received is
automatically unpickled.  Unfortunately unpickling data from an
untrusted source is a security risk.  Therefore *note Listener: 1a0b.
and *note Client(): 36a4. use the *note hmac: 6e. module to provide
digest authentication.

An authentication key is a byte string which can be thought of as a
password: once a connection is established both ends will demand proof
that the other knows the authentication key.  (Demonstrating that both
ends are using the same key does 'not' involve sending the key over the
connection.)

If authentication is requested but no authentication key is specified
then the return value of ‘current_process().authkey’ is used (see *note
Process: 252.).  This value will be automatically inherited by any *note
Process: 252. object that the current process creates.  This means that
(by default) all processes of a multi-process program will share a
single authentication key which can be used when setting up connections
between themselves.

Suitable authentication keys can also be generated by using *note
os.urandom(): 747.


File: python.info,  Node: Logging<2>,  Next: The multiprocessing dummy module,  Prev: Authentication keys,  Up: Reference<3>

5.18.2.26 Logging
.................

Some support for logging is available.  Note, however, that the *note
logging: 8b. package does not use process shared locks so it is possible
(depending on the handler type) for messages from different processes to
get mixed up.

 -- Funzione: multiprocessing.get_logger ()

     Returns the logger used by *note multiprocessing: 98.  If
     necessary, a new one will be created.

     When first created the logger has level *note logging.NOTSET: 313f.
     and no default handler.  Messages sent to this logger will not by
     default propagate to the root logger.

     Note that on Windows child processes will only inherit the level of
     the parent process’s logger – any other customization of the logger
     will not be inherited.

 -- Funzione: multiprocessing.log_to_stderr (level=None)

     This function performs a call to *note get_logger(): 3205. but in
     addition to returning the logger created by get_logger, it adds a
     handler which sends output to *note sys.stderr: b35. using format
     ‘'[%(levelname)s/%(processName)s] %(message)s'’.  You can modify
     ‘levelname’ of the logger by passing a ‘level’ argument.

Below is an example session with logging turned on:

     >>> import multiprocessing, logging
     >>> logger = multiprocessing.log_to_stderr()
     >>> logger.setLevel(logging.INFO)
     >>> logger.warning('doomed')
     [WARNING/MainProcess] doomed
     >>> m = multiprocessing.Manager()
     [INFO/SyncManager-...] child process calling self.run()
     [INFO/SyncManager-...] created temp directory /.../pymp-...
     [INFO/SyncManager-...] manager serving at '/.../listener-...'
     >>> del m
     [INFO/MainProcess] sending shutdown message to manager
     [INFO/SyncManager-...] manager exiting with exitcode 0

For a full table of logging levels, see the *note logging: 8b. module.


File: python.info,  Node: The multiprocessing dummy module,  Prev: Logging<2>,  Up: Reference<3>

5.18.2.27 The ‘multiprocessing.dummy’ module
............................................

*note multiprocessing.dummy: 9a. replicates the API of *note
multiprocessing: 98. but is no more than a wrapper around the *note
threading: f3. module.

In particular, the ‘Pool’ function provided by *note
multiprocessing.dummy: 9a. returns an instance of *note ThreadPool:
1cbc, which is a subclass of *note Pool: 116d. that supports all the
same method calls but uses a pool of worker threads rather than worker
processes.

 -- Classe: multiprocessing.pool.ThreadPool ([processes[, initializer[,
          initargs]]])

     A thread pool object which controls a pool of worker threads to
     which jobs can be submitted.  *note ThreadPool: 1cbc. instances are
     fully interface compatible with *note Pool: 116d. instances, and
     their resources must also be properly managed, either by using the
     pool as a context manager or by calling *note close(): 3697. and
     *note terminate(): 3698. manually.

     'processes' is the number of worker threads to use.  If 'processes'
     is ‘None’ then the number returned by *note os.process_cpu_count():
     4db. is used.

     If 'initializer' is not ‘None’ then each worker process will call
     ‘initializer(*initargs)’ when it starts.

     Unlike *note Pool: 116d, 'maxtasksperchild' and 'context' cannot be
     provided.

          Nota: A *note ThreadPool: 1cbc. shares the same interface as
          *note Pool: 116d, which is designed around a pool of processes
          and predates the introduction of the *note concurrent.futures:
          24. module.  As such, it inherits some operations that don’t
          make sense for a pool backed by threads, and it has its own
          type for representing the status of asynchronous jobs, *note
          AsyncResult: 3699, that is not understood by any other
          libraries.

          Users should generally prefer to use *note
          concurrent.futures.ThreadPoolExecutor: 94a, which has a
          simpler interface that was designed around threads from the
          start, and which returns *note concurrent.futures.Future:
          13ba. instances that are compatible with many other libraries,
          including *note asyncio: b.


File: python.info,  Node: Programming guidelines,  Next: Examples<15>,  Prev: Reference<3>,  Up: multiprocessing — Process-based parallelism

5.18.2.28 Programming guidelines
................................

There are certain guidelines and idioms which should be adhered to when
using *note multiprocessing: 98.

* Menu:

* All start methods::
* The spawn and forkserver start methods::


File: python.info,  Node: All start methods,  Next: The spawn and forkserver start methods,  Up: Programming guidelines

5.18.2.29 All start methods
...........................

The following applies to all start methods.

Avoid shared state

     As far as possible one should try to avoid shifting large amounts
     of data between processes.

     It is probably best to stick to using queues or pipes for
     communication between processes rather than using the lower level
     synchronization primitives.

Picklability

     Ensure that the arguments to the methods of proxies are picklable.

Thread safety of proxies

     Do not use a proxy object from more than one thread unless you
     protect it with a lock.

     (There is never a problem with different processes using the 'same'
     proxy.)

Joining zombie processes

     On POSIX when a process finishes but has not been joined it becomes
     a zombie.  There should never be very many because each time a new
     process starts (or *note active_children(): 365f. is called) all
     completed processes which have not yet been joined will be joined.
     Also calling a finished process’s *note Process.is_alive: 159a.
     will join the process.  Even so it is probably good practice to
     explicitly join all the processes that you start.

Better to inherit than pickle/unpickle

     When using the 'spawn' or 'forkserver' start methods many types
     from *note multiprocessing: 98. need to be picklable so that child
     processes can use them.  However, one should generally avoid
     sending shared objects to other processes using pipes or queues.
     Instead you should arrange the program so that a process which
     needs access to a shared resource created elsewhere can inherit it
     from an ancestor process.

Avoid terminating processes

     Using the *note Process.terminate: 183f. method to stop a process
     is liable to cause any shared resources (such as locks, semaphores,
     pipes and queues) currently being used by the process to become
     broken or unavailable to other processes.

     Therefore it is probably best to only consider using *note
     Process.terminate: 183f. on processes which never use any shared
     resources.

Joining processes that use queues

     Bear in mind that a process that has put items in a queue will wait
     before terminating until all the buffered items are fed by the
     «feeder» thread to the underlying pipe.  (The child process can
     call the *note Queue.cancel_join_thread: 3655. method of the queue
     to avoid this behaviour.)

     This means that whenever you use a queue you need to make sure that
     all items which have been put on the queue will eventually be
     removed before the process is joined.  Otherwise you cannot be sure
     that processes which have put items on the queue will terminate.
     Remember also that non-daemonic processes will be joined
     automatically.

     An example which will deadlock is the following:

          from multiprocessing import Process, Queue

          def f(q):
              q.put('X' * 1000000)

          if __name__ == '__main__':
              queue = Queue()
              p = Process(target=f, args=(queue,))
              p.start()
              p.join()                    # this deadlocks
              obj = queue.get()

     A fix here would be to swap the last two lines (or simply remove
     the ‘p.join()’ line).

Explicitly pass resources to child processes

     On POSIX using the 'fork' start method, a child process can make
     use of a shared resource created in a parent process using a global
     resource.  However, it is better to pass the object as an argument
     to the constructor for the child process.

     Apart from making the code (potentially) compatible with Windows
     and the other start methods this also ensures that as long as the
     child process is still alive the object will not be garbage
     collected in the parent process.  This might be important if some
     resource is freed when the object is garbage collected in the
     parent process.

     So for instance

          from multiprocessing import Process, Lock

          def f():
              ... do something using "lock" ...

          if __name__ == '__main__':
              lock = Lock()
              for i in range(10):
                  Process(target=f).start()

     should be rewritten as

          from multiprocessing import Process, Lock

          def f(l):
              ... do something using "l" ...

          if __name__ == '__main__':
              lock = Lock()
              for i in range(10):
                  Process(target=f, args=(lock,)).start()

Beware of replacing *note sys.stdin: 760. with a «file like object»

     *note multiprocessing: 98. originally unconditionally called:

          os.close(sys.stdin.fileno())

     in the ‘multiprocessing.Process._bootstrap()’ method — this
     resulted in issues with processes-in-processes.  This has been
     changed to:

          sys.stdin.close()
          sys.stdin = open(os.open(os.devnull, os.O_RDONLY), closefd=False)

     Which solves the fundamental issue of processes colliding with each
     other resulting in a bad file descriptor error, but introduces a
     potential danger to applications which replace *note sys.stdin():
     760. with a «file-like object» with output buffering.  This danger
     is that if multiple processes call *note close(): 507. on this
     file-like object, it could result in the same data being flushed to
     the object multiple times, resulting in corruption.

     If you write a file-like object and implement your own caching, you
     can make it fork-safe by storing the pid whenever you append to the
     cache, and discarding the cache when the pid changes.  For example:

          @property
          def cache(self):
              pid = os.getpid()
              if pid != self._pid:
                  self._pid = pid
                  self._cache = []
              return self._cache

     For more information, see bpo-5155(1), bpo-5313(2) and bpo-5331(3)

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=5155

   (2) https://bugs.python.org/issue?@action=redirect&bpo=5313

   (3) https://bugs.python.org/issue?@action=redirect&bpo=5331


File: python.info,  Node: The spawn and forkserver start methods,  Prev: All start methods,  Up: Programming guidelines

5.18.2.30 The 'spawn' and 'forkserver' start methods
....................................................

There are a few extra restrictions which don’t apply to the 'fork' start
method.

More picklability

     Ensure that all arguments to *note Process: 252. are picklable.
     Also, if you subclass ‘Process.__init__’, you must make sure that
     instances will be picklable when the *note Process.start: 1599.
     method is called.

Global variables

     Bear in mind that if code run in a child process tries to access a
     global variable, then the value it sees (if any) may not be the
     same as the value in the parent process at the time that *note
     Process.start: 1599. was called.

     However, global variables which are just module level constants
     cause no problems.
Safe importing of main module

     Make sure that the main module can be safely imported by a new
     Python interpreter without causing unintended side effects (such as
     starting a new process).

     For example, using the 'spawn' or 'forkserver' start method running
     the following module would fail with a *note RuntimeError: 244.:

          from multiprocessing import Process

          def foo():
              print('hello')

          p = Process(target=foo)
          p.start()

     Instead one should protect the «entry point» of the program by
     using ‘if __name__ == '__main__':’ as follows:

          from multiprocessing import Process, freeze_support, set_start_method

          def foo():
              print('hello')

          if __name__ == '__main__':
              freeze_support()
              set_start_method('spawn')
              p = Process(target=foo)
              p.start()

     (The ‘freeze_support()’ line can be omitted if the program will be
     run normally instead of frozen.)

     This allows the newly spawned Python interpreter to safely import
     the module and then run the module’s ‘foo()’ function.

     Similar restrictions apply if a pool or manager is created in the
     main module.


File: python.info,  Node: Examples<15>,  Prev: Programming guidelines,  Up: multiprocessing — Process-based parallelism

5.18.2.31 Examples
..................

Demonstration of how to create and use customized managers and proxies:

     from multiprocessing import freeze_support
     from multiprocessing.managers import BaseManager, BaseProxy
     import operator

     ##

     class Foo:
         def f(self):
             print('you called Foo.f()')
         def g(self):
             print('you called Foo.g()')
         def _h(self):
             print('you called Foo._h()')

     # A simple generator function
     def baz():
         for i in range(10):
             yield i*i

     # Proxy type for generator objects
     class GeneratorProxy(BaseProxy):
         _exposed_ = ['__next__']
         def __iter__(self):
             return self
         def __next__(self):
             return self._callmethod('__next__')

     # Function to return the operator module
     def get_operator_module():
         return operator

     ##

     class MyManager(BaseManager):
         pass

     # register the Foo class; make `f()` and `g()` accessible via proxy
     MyManager.register('Foo1', Foo)

     # register the Foo class; make `g()` and `_h()` accessible via proxy
     MyManager.register('Foo2', Foo, exposed=('g', '_h'))

     # register the generator function baz; use `GeneratorProxy` to make proxies
     MyManager.register('baz', baz, proxytype=GeneratorProxy)

     # register get_operator_module(); make public functions accessible via proxy
     MyManager.register('operator', get_operator_module)

     ##

     def test():
         manager = MyManager()
         manager.start()

         print('-' * 20)

         f1 = manager.Foo1()
         f1.f()
         f1.g()
         assert not hasattr(f1, '_h')
         assert sorted(f1._exposed_) == sorted(['f', 'g'])

         print('-' * 20)

         f2 = manager.Foo2()
         f2.g()
         f2._h()
         assert not hasattr(f2, 'f')
         assert sorted(f2._exposed_) == sorted(['g', '_h'])

         print('-' * 20)

         it = manager.baz()
         for i in it:
             print('<%d>' % i, end=' ')
         print()

         print('-' * 20)

         op = manager.operator()
         print('op.add(23, 45) =', op.add(23, 45))
         print('op.pow(2, 94) =', op.pow(2, 94))
         print('op._exposed_ =', op._exposed_)

     ##

     if __name__ == '__main__':
         freeze_support()
         test()

Using *note Pool: 116d.:

     import multiprocessing
     import time
     import random
     import sys

     #
     # Functions used by test code
     #

     def calculate(func, args):
         result = func(*args)
         return '%s says that %s%s = %s' % (
             multiprocessing.current_process().name,
             func.__name__, args, result
             )

     def calculatestar(args):
         return calculate(*args)

     def mul(a, b):
         time.sleep(0.5 * random.random())
         return a * b

     def plus(a, b):
         time.sleep(0.5 * random.random())
         return a + b

     def f(x):
         return 1.0 / (x - 5.0)

     def pow3(x):
         return x ** 3

     def noop(x):
         pass

     #
     # Test code
     #

     def test():
         PROCESSES = 4
         print('Creating pool with %d processes\n' % PROCESSES)

         with multiprocessing.Pool(PROCESSES) as pool:
             #
             # Tests
             #

             TASKS = [(mul, (i, 7)) for i in range(10)] + \
                     [(plus, (i, 8)) for i in range(10)]

             results = [pool.apply_async(calculate, t) for t in TASKS]
             imap_it = pool.imap(calculatestar, TASKS)
             imap_unordered_it = pool.imap_unordered(calculatestar, TASKS)

             print('Ordered results using pool.apply_async():')
             for r in results:
                 print('\t', r.get())
             print()

             print('Ordered results using pool.imap():')
             for x in imap_it:
                 print('\t', x)
             print()

             print('Unordered results using pool.imap_unordered():')
             for x in imap_unordered_it:
                 print('\t', x)
             print()

             print('Ordered results using pool.map() --- will block till complete:')
             for x in pool.map(calculatestar, TASKS):
                 print('\t', x)
             print()

             #
             # Test error handling
             #

             print('Testing error handling:')

             try:
                 print(pool.apply(f, (5,)))
             except ZeroDivisionError:
                 print('\tGot ZeroDivisionError as expected from pool.apply()')
             else:
                 raise AssertionError('expected ZeroDivisionError')

             try:
                 print(pool.map(f, list(range(10))))
             except ZeroDivisionError:
                 print('\tGot ZeroDivisionError as expected from pool.map()')
             else:
                 raise AssertionError('expected ZeroDivisionError')

             try:
                 print(list(pool.imap(f, list(range(10)))))
             except ZeroDivisionError:
                 print('\tGot ZeroDivisionError as expected from list(pool.imap())')
             else:
                 raise AssertionError('expected ZeroDivisionError')

             it = pool.imap(f, list(range(10)))
             for i in range(10):
                 try:
                     x = next(it)
                 except ZeroDivisionError:
                     if i == 5:
                         pass
                 except StopIteration:
                     break
                 else:
                     if i == 5:
                         raise AssertionError('expected ZeroDivisionError')

             assert i == 9
             print('\tGot ZeroDivisionError as expected from IMapIterator.next()')
             print()

             #
             # Testing timeouts
             #

             print('Testing ApplyResult.get() with timeout:', end=' ')
             res = pool.apply_async(calculate, TASKS[0])
             while 1:
                 sys.stdout.flush()
                 try:
                     sys.stdout.write('\n\t%s' % res.get(0.02))
                     break
                 except multiprocessing.TimeoutError:
                     sys.stdout.write('.')
             print()
             print()

             print('Testing IMapIterator.next() with timeout:', end=' ')
             it = pool.imap(calculatestar, TASKS)
             while 1:
                 sys.stdout.flush()
                 try:
                     sys.stdout.write('\n\t%s' % it.next(0.02))
                 except StopIteration:
                     break
                 except multiprocessing.TimeoutError:
                     sys.stdout.write('.')
             print()
             print()


     if __name__ == '__main__':
         multiprocessing.freeze_support()
         test()

An example showing how to use queues to feed tasks to a collection of
worker processes and collect the results:

     import time
     import random

     from multiprocessing import Process, Queue, current_process, freeze_support

     #
     # Function run by worker processes
     #

     def worker(input, output):
         for func, args in iter(input.get, 'STOP'):
             result = calculate(func, args)
             output.put(result)

     #
     # Function used to calculate result
     #

     def calculate(func, args):
         result = func(*args)
         return '%s says that %s%s = %s' % \
             (current_process().name, func.__name__, args, result)

     #
     # Functions referenced by tasks
     #

     def mul(a, b):
         time.sleep(0.5*random.random())
         return a * b

     def plus(a, b):
         time.sleep(0.5*random.random())
         return a + b

     #
     #
     #

     def test():
         NUMBER_OF_PROCESSES = 4
         TASKS1 = [(mul, (i, 7)) for i in range(20)]
         TASKS2 = [(plus, (i, 8)) for i in range(10)]

         # Create queues
         task_queue = Queue()
         done_queue = Queue()

         # Submit tasks
         for task in TASKS1:
             task_queue.put(task)

         # Start worker processes
         for i in range(NUMBER_OF_PROCESSES):
             Process(target=worker, args=(task_queue, done_queue)).start()

         # Get and print results
         print('Unordered results:')
         for i in range(len(TASKS1)):
             print('\t', done_queue.get())

         # Add more tasks using `put()`
         for task in TASKS2:
             task_queue.put(task)

         # Get and print some more results
         for i in range(len(TASKS2)):
             print('\t', done_queue.get())

         # Tell child processes to stop
         for i in range(NUMBER_OF_PROCESSES):
             task_queue.put('STOP')


     if __name__ == '__main__':
         freeze_support()
         test()


File: python.info,  Node: multiprocessing shared_memory — Shared memory for direct access across processes,  Next: The concurrent package,  Prev: multiprocessing — Process-based parallelism,  Up: Concurrent Execution

5.18.3 ‘multiprocessing.shared_memory’ — Shared memory for direct access across processes
-----------------------------------------------------------------------------------------

'Source code:' Lib/multiprocessing/shared_memory.py(1)

Added in version 3.8.

__________________________________________________________________

This module provides a class, *note SharedMemory: 19c0, for the
allocation and management of shared memory to be accessed by one or more
processes on a multicore or symmetric multiprocessor (SMP) machine.  To
assist with the life-cycle management of shared memory especially across
distinct processes, a *note BaseManager: 367d. subclass, *note
SharedMemoryManager: 36b6, is also provided in the *note
multiprocessing.managers: 9b. module.

In this module, shared memory refers to «POSIX style» shared memory
blocks (though is not necessarily implemented explicitly as such) and
does not refer to «distributed shared memory».  This style of shared
memory permits distinct processes to potentially read and write to a
common (or shared) region of volatile memory.  Processes are
conventionally limited to only have access to their own process memory
space but shared memory permits the sharing of data between processes,
avoiding the need to instead send messages between processes containing
that data.  Sharing data directly via memory can provide significant
performance benefits compared to sharing data via disk or socket or
other communications requiring the serialization/deserialization and
copying of data.

 -- Classe: multiprocessing.shared_memory.SharedMemory (name=None,
          create=False, size=0, *, track=True)

     Create an instance of the ‘SharedMemory’ class for either creating
     a new shared memory block or attaching to an existing shared memory
     block.  Each shared memory block is assigned a unique name.  In
     this way, one process can create a shared memory block with a
     particular name and a different process can attach to that same
     shared memory block using that same name.

     As a resource for sharing data across processes, shared memory
     blocks may outlive the original process that created them.  When
     one process no longer needs access to a shared memory block that
     might still be needed by other processes, the *note close(): 36b7.
     method should be called.  When a shared memory block is no longer
     needed by any process, the *note unlink(): 36b8. method should be
     called to ensure proper cleanup.


     Parametri:

        * ‘name’ (*note str: 169.‘ | ’‘None’) – The unique name for the
          requested shared memory, specified as a string.  When creating
          a new shared memory block, if ‘None’ (the default) is supplied
          for the name, a novel name will be generated.

        * ‘create’ (*note bool: 3c3.) – Control whether a new shared
          memory block is created (‘True’) or an existing shared memory
          block is attached (‘False’).

        * ‘size’ (*note int: 19b.) – The requested number of bytes when
          creating a new shared memory block.  Because some platforms
          choose to allocate chunks of memory based upon that platform’s
          memory page size, the exact size of the shared memory block
          may be larger or equal to the size requested.  When attaching
          to an existing shared memory block, the 'size' parameter is
          ignored.

        * ‘track’ (*note bool: 3c3.) – When ‘True’, register the shared
          memory block with a resource tracker process on platforms
          where the OS does not do this automatically.  The resource
          tracker ensures proper cleanup of the shared memory even if
          all other processes with access to the memory exit without
          doing so.  Python processes created from a common ancestor
          using *note multiprocessing: 98. facilities share a single
          resource tracker process, and the lifetime of shared memory
          segments is handled automatically among these processes.
          Python processes created in any other way will receive their
          own resource tracker when accessing shared memory with 'track'
          enabled.  This will cause the shared memory to be deleted by
          the resource tracker of the first process that terminates.  To
          avoid this issue, users of *note subprocess: dc. or standalone
          Python processes should set 'track' to ‘False’ when there is
          already another process in place that does the bookkeeping.
          'track' is ignored on Windows, which has its own tracking and
          automatically deletes shared memory when all handles to it
          have been closed.

     Cambiato nella versione 3.13: Added the 'track' parameter.

      -- Metodo: close ()

          Close the file descriptor/handle to the shared memory from
          this instance.  *note close(): 36b7. should be called once
          access to the shared memory block from this instance is no
          longer needed.  Depending on operating system, the underlying
          memory may or may not be freed even if all handles to it have
          been closed.  To ensure proper cleanup, use the *note
          unlink(): 36b8. method.

      -- Metodo: unlink ()

          Delete the underlying shared memory block.  This should be
          called only once per shared memory block regardless of the
          number of handles to it, even in other processes.  *note
          unlink(): 36b8. and *note close(): 36b7. can be called in any
          order, but trying to access data inside a shared memory block
          after *note unlink(): 36b8. may result in memory access
          errors, depending on platform.

          This method has no effect on Windows, where the only way to
          delete a shared memory block is to close all handles.

      -- Attributo: buf

          A memoryview of contents of the shared memory block.

      -- Attributo: name

          Read-only access to the unique name of the shared memory
          block.

      -- Attributo: size

          Read-only access to size in bytes of the shared memory block.

The following example demonstrates low-level use of *note SharedMemory:
19c0. instances:

     >>> from multiprocessing import shared_memory
     >>> shm_a = shared_memory.SharedMemory(create=True, size=10)
     >>> type(shm_a.buf)
     <class 'memoryview'>
     >>> buffer = shm_a.buf
     >>> len(buffer)
     10
     >>> buffer[:4] = bytearray([22, 33, 44, 55])  # Modify multiple at once
     >>> buffer[4] = 100                           # Modify single byte at a time
     >>> # Attach to an existing shared memory block
     >>> shm_b = shared_memory.SharedMemory(shm_a.name)
     >>> import array
     >>> array.array('b', shm_b.buf[:5])  # Copy the data into a new array.array
     array('b', [22, 33, 44, 55, 100])
     >>> shm_b.buf[:5] = b'howdy'  # Modify via shm_b using bytes
     >>> bytes(shm_a.buf[:5])      # Access via shm_a
     b'howdy'
     >>> shm_b.close()   # Close each SharedMemory instance
     >>> shm_a.close()
     >>> shm_a.unlink()  # Call unlink only once to release the shared memory

The following example demonstrates a practical use of the *note
SharedMemory: 19c0. class with NumPy arrays(2), accessing the same
‘numpy.ndarray’ from two distinct Python shells:

     >>> # In the first Python interactive shell
     >>> import numpy as np
     >>> a = np.array([1, 1, 2, 3, 5, 8])  # Start with an existing NumPy array
     >>> from multiprocessing import shared_memory
     >>> shm = shared_memory.SharedMemory(create=True, size=a.nbytes)
     >>> # Now create a NumPy array backed by shared memory
     >>> b = np.ndarray(a.shape, dtype=a.dtype, buffer=shm.buf)
     >>> b[:] = a[:]  # Copy the original data into shared memory
     >>> b
     array([1, 1, 2, 3, 5, 8])
     >>> type(b)
     <class 'numpy.ndarray'>
     >>> type(a)
     <class 'numpy.ndarray'>
     >>> shm.name  # We did not specify a name so one was chosen for us
     'psm_21467_46075'

     >>> # In either the same shell or a new Python shell on the same machine
     >>> import numpy as np
     >>> from multiprocessing import shared_memory
     >>> # Attach to the existing shared memory block
     >>> existing_shm = shared_memory.SharedMemory(name='psm_21467_46075')
     >>> # Note that a.shape is (6,) and a.dtype is np.int64 in this example
     >>> c = np.ndarray((6,), dtype=np.int64, buffer=existing_shm.buf)
     >>> c
     array([1, 1, 2, 3, 5, 8])
     >>> c[-1] = 888
     >>> c
     array([  1,   1,   2,   3,   5, 888])

     >>> # Back in the first Python interactive shell, b reflects this change
     >>> b
     array([  1,   1,   2,   3,   5, 888])

     >>> # Clean up from within the second Python shell
     >>> del c  # Unnecessary; merely emphasizing the array is no longer used
     >>> existing_shm.close()

     >>> # Clean up from within the first Python shell
     >>> del b  # Unnecessary; merely emphasizing the array is no longer used
     >>> shm.close()
     >>> shm.unlink()  # Free and release the shared memory block at the very end

 -- Classe: multiprocessing.managers.SharedMemoryManager ([address[,
          authkey]])

     A subclass of *note multiprocessing.managers.BaseManager: 367d.
     which can be used for the management of shared memory blocks across
     processes.

     A call to *note start(): 367e. on a ‘SharedMemoryManager’ instance
     causes a new process to be started.  This new process’s sole
     purpose is to manage the life cycle of all shared memory blocks
     created through it.  To trigger the release of all shared memory
     blocks managed by that process, call *note shutdown(): 367f. on the
     instance.  This triggers a *note unlink(): 36b8. call on all of the
     *note SharedMemory: 36bc. objects managed by that process and then
     stops the process itself.  By creating ‘SharedMemory’ instances
     through a ‘SharedMemoryManager’, we avoid the need to manually
     track and trigger the freeing of shared memory resources.

     This class provides methods for creating and returning *note
     SharedMemory: 36bc. instances and for creating a list-like object
     (*note ShareableList: 36bd.) backed by shared memory.

     Refer to *note BaseManager: 367d. for a description of the
     inherited 'address' and 'authkey' optional input arguments and how
     they may be used to connect to an existing ‘SharedMemoryManager’
     service from other processes.

      -- Metodo: SharedMemory (size)

          Create and return a new *note SharedMemory: 36bc. object with
          the specified 'size' in bytes.

      -- Metodo: ShareableList (sequence)

          Create and return a new *note ShareableList: 36bd. object,
          initialized by the values from the input 'sequence'.

The following example demonstrates the basic mechanisms of a *note
SharedMemoryManager: 36b6.:

     >>> from multiprocessing.managers import SharedMemoryManager
     >>> smm = SharedMemoryManager()
     >>> smm.start()  # Start the process that manages the shared memory blocks
     >>> sl = smm.ShareableList(range(4))
     >>> sl
     ShareableList([0, 1, 2, 3], name='psm_6572_7512')
     >>> raw_shm = smm.SharedMemory(size=128)
     >>> another_sl = smm.ShareableList('alpha')
     >>> another_sl
     ShareableList(['a', 'l', 'p', 'h', 'a'], name='psm_6572_12221')
     >>> smm.shutdown()  # Calls unlink() on sl, raw_shm, and another_sl

The following example depicts a potentially more convenient pattern for
using *note SharedMemoryManager: 36b6. objects via the *note with: 186.
statement to ensure that all shared memory blocks are released after
they are no longer needed:

     >>> with SharedMemoryManager() as smm:
     ...     sl = smm.ShareableList(range(2000))
     ...     # Divide the work among two processes, storing partial results in sl
     ...     p1 = Process(target=do_work, args=(sl, 0, 1000))
     ...     p2 = Process(target=do_work, args=(sl, 1000, 2000))
     ...     p1.start()
     ...     p2.start()  # A multiprocessing.Pool might be more efficient
     ...     p1.join()
     ...     p2.join()   # Wait for all work to complete in both processes
     ...     total_result = sum(sl)  # Consolidate the partial results now in sl

When using a *note SharedMemoryManager: 36b6. in a *note with: 186.
statement, the shared memory blocks created using that manager are all
released when the ‘with’ statement’s code block finishes execution.

 -- Classe: multiprocessing.shared_memory.ShareableList (sequence=None,
          *, name=None)

     Provide a mutable list-like object where all values stored within
     are stored in a shared memory block.  This constrains storable
     values to the following built-in data types:

        * *note int: 19b. (signed 64-bit)

        * *note float: 196.

        * *note bool: 3c3.

        * *note str: 169. (less than 10M bytes each when encoded as
          UTF-8)

        * *note bytes: 192. (less than 10M bytes each)

        * ‘None’

     It also notably differs from the built-in *note list: 24d. type in
     that these lists can not change their overall length (i.e.  no
     ‘append()’, ‘insert()’, etc.)  and do not support the dynamic
     creation of new ‘ShareableList’ instances via slicing.

     'sequence' is used in populating a new ‘ShareableList’ full of
     values.  Set to ‘None’ to instead attach to an already existing
     ‘ShareableList’ by its unique shared memory name.

     'name' is the unique name for the requested shared memory, as
     described in the definition for *note SharedMemory: 19c0.  When
     attaching to an existing ‘ShareableList’, specify its shared memory
     block’s unique name while leaving 'sequence' set to ‘None’.

          Nota: A known issue exists for *note bytes: 192. and *note
          str: 169. values.  If they end with ‘\x00’ nul bytes or
          characters, those may be 'silently stripped' when fetching
          them by index from the ‘ShareableList’.  This
          ‘.rstrip(b'\x00')’ behavior is considered a bug and may go
          away in the future.  See gh-106939(3).

     For applications where rstripping of trailing nulls is a problem,
     work around it by always unconditionally appending an extra non-0
     byte to the end of such values when storing and unconditionally
     removing it when fetching:

          >>> from multiprocessing import shared_memory
          >>> nul_bug_demo = shared_memory.ShareableList(['?\x00', b'\x03\x02\x01\x00\x00\x00'])
          >>> nul_bug_demo[0]
          '?'
          >>> nul_bug_demo[1]
          b'\x03\x02\x01'
          >>> nul_bug_demo.shm.unlink()
          >>> padded = shared_memory.ShareableList(['?\x00\x07', b'\x03\x02\x01\x00\x00\x00\x07'])
          >>> padded[0][:-1]
          '?\x00'
          >>> padded[1][:-1]
          b'\x03\x02\x01\x00\x00\x00'
          >>> padded.shm.unlink()

      -- Metodo: count (value)

          Return the number of occurrences of 'value'.

      -- Metodo: index (value)

          Return first index position of 'value'.  Raise *note
          ValueError: 2ec. if 'value' is not present.

      -- Attributo: format

          Read-only attribute containing the *note struct: db. packing
          format used by all currently stored values.

      -- Attributo: shm

          The *note SharedMemory: 19c0. instance where the values are
          stored.

The following example demonstrates basic use of a *note ShareableList:
1d40. instance:

     >>> from multiprocessing import shared_memory
     >>> a = shared_memory.ShareableList(['howdy', b'HoWdY', -273.154, 100, None, True, 42])
     >>> [ type(entry) for entry in a ]
     [<class 'str'>, <class 'bytes'>, <class 'float'>, <class 'int'>, <class 'NoneType'>, <class 'bool'>, <class 'int'>]
     >>> a[2]
     -273.154
     >>> a[2] = -78.5
     >>> a[2]
     -78.5
     >>> a[2] = 'dry ice'  # Changing data types is supported as well
     >>> a[2]
     'dry ice'
     >>> a[2] = 'larger than previously allocated storage space'
     Traceback (most recent call last):
       ...
     ValueError: exceeds available storage for existing str
     >>> a[2]
     'dry ice'
     >>> len(a)
     7
     >>> a.index(42)
     6
     >>> a.count(b'howdy')
     0
     >>> a.count(b'HoWdY')
     1
     >>> a.shm.close()
     >>> a.shm.unlink()
     >>> del a  # Use of a ShareableList after call to unlink() is unsupported

The following example depicts how one, two, or many processes may access
the same *note ShareableList: 1d40. by supplying the name of the shared
memory block behind it:

     >>> b = shared_memory.ShareableList(range(5))         # In a first process
     >>> c = shared_memory.ShareableList(name=b.shm.name)  # In a second process
     >>> c
     ShareableList([0, 1, 2, 3, 4], name='...')
     >>> c[-1] = -999
     >>> b[-1]
     -999
     >>> b.shm.close()
     >>> c.shm.close()
     >>> c.shm.unlink()

The following examples demonstrates that *note ShareableList: 1d40. (and
underlying *note SharedMemory: 19c0.) objects can be pickled and
unpickled if needed.  Note, that it will still be the same shared
object.  This happens, because the deserialized object has the same
unique name and is just attached to an existing object with the same
name (if the object is still alive):

     >>> import pickle
     >>> from multiprocessing import shared_memory
     >>> sl = shared_memory.ShareableList(range(10))
     >>> list(sl)
     [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

     >>> deserialized_sl = pickle.loads(pickle.dumps(sl))
     >>> list(deserialized_sl)
     [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

     >>> sl[0] = -1
     >>> deserialized_sl[1] = -2
     >>> list(sl)
     [-1, -2, 2, 3, 4, 5, 6, 7, 8, 9]
     >>> list(deserialized_sl)
     [-1, -2, 2, 3, 4, 5, 6, 7, 8, 9]

     >>> sl.shm.close()
     >>> sl.shm.unlink()

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/multiprocessing/shared_memory.py

   (2) https://numpy.org/

   (3) https://github.com/python/cpython/issues/106939


File: python.info,  Node: The concurrent package,  Next: concurrent futures — Launching parallel tasks,  Prev: multiprocessing shared_memory — Shared memory for direct access across processes,  Up: Concurrent Execution

5.18.4 The ‘concurrent’ package
-------------------------------

This package contains the following modules:

   * *note concurrent.futures: 24. – Launching parallel tasks

   * *note concurrent.interpreters: 25. – Multiple interpreters in the
     same process


File: python.info,  Node: concurrent futures — Launching parallel tasks,  Next: concurrent interpreters — Multiple interpreters in the same process,  Prev: The concurrent package,  Up: Concurrent Execution

5.18.5 ‘concurrent.futures’ — Launching parallel tasks
------------------------------------------------------

Added in version 3.2.

'Source code:' Lib/concurrent/futures/thread.py(1),
Lib/concurrent/futures/process.py(2), and
Lib/concurrent/futures/interpreter.py(3)

__________________________________________________________________

The *note concurrent.futures: 24. module provides a high-level interface
for asynchronously executing callables.

The asynchronous execution can be performed with threads, using *note
ThreadPoolExecutor: 94a. or *note InterpreterPoolExecutor: 1d2, or
separate processes, using *note ProcessPoolExecutor: 1d6.  Each
implements the same interface, which is defined by the abstract *note
Executor: 36c8. class.

*note concurrent.futures.Future: 13ba. must not be confused with *note
asyncio.Future: dc8, which is designed for use with *note asyncio: b.
tasks and coroutines.  See the *note asyncio’s Future: 36c9.
documentation for a detailed comparison of the two.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

* Menu:

* Executor Objects::
* ThreadPoolExecutor::
* InterpreterPoolExecutor::
* ProcessPoolExecutor::
* Future Objects::
* Module Functions::
* Exception classes::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/concurrent/futures/thread.py

   (2) 
https://github.com/python/cpython/tree/3.14/Lib/concurrent/futures/process.py

   (3) 
https://github.com/python/cpython/tree/3.14/Lib/concurrent/futures/interpreter.py


File: python.info,  Node: Executor Objects,  Next: ThreadPoolExecutor,  Up: concurrent futures — Launching parallel tasks

5.18.5.1 Executor Objects
.........................

 -- Classe: concurrent.futures.Executor

     An abstract class that provides methods to execute calls
     asynchronously.  It should not be used directly, but through its
     concrete subclasses.

      -- Metodo: submit (fn, /, *args, **kwargs)

          Schedules the callable, 'fn', to be executed as ‘fn(*args,
          **kwargs)’ and returns a *note Future: 13ba. object
          representing the execution of the callable.

               with ThreadPoolExecutor(max_workers=1) as executor:
                   future = executor.submit(pow, 323, 1235)
                   print(future.result())

      -- Metodo: map (fn, *iterables, timeout=None, chunksize=1,
               buffersize=None)

          Similar to *note map(fn, *iterables): 19f. except:

             * The 'iterables' are collected immediately rather than
               lazily, unless a 'buffersize' is specified to limit the
               number of submitted tasks whose results have not yet been
               yielded.  If the buffer is full, iteration over the
               'iterables' pauses until a result is yielded from the
               buffer.

             * 'fn' is executed asynchronously and several calls to 'fn'
               may be made concurrently.

          The returned iterator raises a *note TimeoutError: a38. if
          *note __next__(): 14d5. is called and the result isn’t
          available after 'timeout' seconds from the original call to
          *note Executor.map(): 1dc.  'timeout' can be an int or a
          float.  If 'timeout' is not specified or ‘None’, there is no
          limit to the wait time.

          If a 'fn' call raises an exception, then that exception will
          be raised when its value is retrieved from the iterator.

          When using *note ProcessPoolExecutor: 1d6, this method chops
          'iterables' into a number of chunks which it submits to the
          pool as separate tasks.  The (approximate) size of these
          chunks can be specified by setting 'chunksize' to a positive
          integer.  For very long iterables, using a large value for
          'chunksize' can significantly improve performance compared to
          the default size of 1.  With *note ThreadPoolExecutor: 94a.
          and *note InterpreterPoolExecutor: 1d2, 'chunksize' has no
          effect.

          Cambiato nella versione 3.5: Added the 'chunksize' parameter.

          Cambiato nella versione 3.14: Added the 'buffersize'
          parameter.

      -- Metodo: shutdown (wait=True, *, cancel_futures=False)

          Signal the executor that it should free any resources that it
          is using when the currently pending futures are done
          executing.  Calls to *note Executor.submit(): c77. and *note
          Executor.map(): 1dc. made after shutdown will raise *note
          RuntimeError: 244.

          If 'wait' is ‘True’ then this method will not return until all
          the pending futures are done executing and the resources
          associated with the executor have been freed.  If 'wait' is
          ‘False’ then this method will return immediately and the
          resources associated with the executor will be freed when all
          pending futures are done executing.  Regardless of the value
          of 'wait', the entire Python program will not exit until all
          pending futures are done executing.

          If 'cancel_futures' is ‘True’, this method will cancel all
          pending futures that the executor has not started running.
          Any futures that are completed or running won’t be cancelled,
          regardless of the value of 'cancel_futures'.

          If both 'cancel_futures' and 'wait' are ‘True’, all futures
          that the executor has started running will be completed prior
          to this method returning.  The remaining futures are
          cancelled.

          You can avoid having to call this method explicitly if you use
          the executor as a *note context manager: 1e1. via the *note
          with: 186. statement, which will shutdown the *note Executor:
          36c8. (waiting as if *note Executor.shutdown(): aec. were
          called with 'wait' set to ‘True’):

               import shutil
               with ThreadPoolExecutor(max_workers=4) as e:
                   e.submit(shutil.copy, 'src1.txt', 'dest1.txt')
                   e.submit(shutil.copy, 'src2.txt', 'dest2.txt')
                   e.submit(shutil.copy, 'src3.txt', 'dest3.txt')
                   e.submit(shutil.copy, 'src4.txt', 'dest4.txt')

          Cambiato nella versione 3.9: Added 'cancel_futures'.


File: python.info,  Node: ThreadPoolExecutor,  Next: InterpreterPoolExecutor,  Prev: Executor Objects,  Up: concurrent futures — Launching parallel tasks

5.18.5.2 ThreadPoolExecutor
...........................

*note ThreadPoolExecutor: 94a. is an *note Executor: 36c8. subclass that
uses a pool of threads to execute calls asynchronously.

Deadlocks can occur when the callable associated with a *note Future:
13ba. waits on the results of another *note Future: 13ba.  For example:

     import time
     def wait_on_b():
         time.sleep(5)
         print(b.result())  # b will never complete because it is waiting on a.
         return 5

     def wait_on_a():
         time.sleep(5)
         print(a.result())  # a will never complete because it is waiting on b.
         return 6


     executor = ThreadPoolExecutor(max_workers=2)
     a = executor.submit(wait_on_b)
     b = executor.submit(wait_on_a)

And:

     def wait_on_future():
         f = executor.submit(pow, 5, 2)
         # This will never complete because there is only one worker thread and
         # it is executing this function.
         print(f.result())

     executor = ThreadPoolExecutor(max_workers=1)
     executor.submit(wait_on_future)

 -- Classe: concurrent.futures.ThreadPoolExecutor (max_workers=None,
          thread_name_prefix='', initializer=None, initargs=())

     An *note Executor: 36c8. subclass that uses a pool of at most
     'max_workers' threads to execute calls asynchronously.

     All threads enqueued to ‘ThreadPoolExecutor’ will be joined before
     the interpreter can exit.  Note that the exit handler which does
     this is executed 'before' any exit handlers added using ‘atexit’.
     This means exceptions in the main thread must be caught and handled
     in order to signal threads to exit gracefully.  For this reason, it
     is recommended that ‘ThreadPoolExecutor’ not be used for
     long-running tasks.

     'initializer' is an optional callable that is called at the start
     of each worker thread; 'initargs' is a tuple of arguments passed to
     the initializer.  Should 'initializer' raise an exception, all
     currently pending jobs will raise a *note BrokenThreadPool: 36cc,
     as well as any attempt to submit more jobs to the pool.

     Cambiato nella versione 3.5: If 'max_workers' is ‘None’ or not
     given, it will default to the number of processors on the machine,
     multiplied by ‘5’, assuming that *note ThreadPoolExecutor: 94a. is
     often used to overlap I/O instead of CPU work and the number of
     workers should be higher than the number of workers for *note
     ProcessPoolExecutor: 1d6.

     Cambiato nella versione 3.6: Added the 'thread_name_prefix'
     parameter to allow users to control the *note threading.Thread:
     176. names for worker threads created by the pool for easier
     debugging.

     Cambiato nella versione 3.7: Added the 'initializer' and 'initargs'
     arguments.

     Cambiato nella versione 3.8: Default value of 'max_workers' is
     changed to ‘min(32, os.cpu_count() + 4)’.  This default value
     preserves at least 5 workers for I/O bound tasks.  It utilizes at
     most 32 CPU cores for CPU bound tasks which release the GIL. And it
     avoids using very large resources implicitly on many-core machines.

     ThreadPoolExecutor now reuses idle worker threads before starting
     'max_workers' worker threads too.

     Cambiato nella versione 3.13: Default value of 'max_workers' is
     changed to ‘min(32, (os.process_cpu_count() or 1) + 4)’.

* Menu:

* ThreadPoolExecutor Example::


File: python.info,  Node: ThreadPoolExecutor Example,  Up: ThreadPoolExecutor

5.18.5.3 ThreadPoolExecutor Example
...................................

     import concurrent.futures
     import urllib.request

     URLS = ['http://www.foxnews.com/',
             'http://www.cnn.com/',
             'http://europe.wsj.com/',
             'http://www.bbc.co.uk/',
             'http://nonexistent-subdomain.python.org/']

     # Retrieve a single page and report the URL and contents
     def load_url(url, timeout):
         with urllib.request.urlopen(url, timeout=timeout) as conn:
             return conn.read()

     # We can use a with statement to ensure threads are cleaned up promptly
     with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:
         # Start the load operations and mark each future with its URL
         future_to_url = {executor.submit(load_url, url, 60): url for url in URLS}
         for future in concurrent.futures.as_completed(future_to_url):
             url = future_to_url[future]
             try:
                 data = future.result()
             except Exception as exc:
                 print('%r generated an exception: %s' % (url, exc))
             else:
                 print('%r page is %d bytes' % (url, len(data)))


File: python.info,  Node: InterpreterPoolExecutor,  Next: ProcessPoolExecutor,  Prev: ThreadPoolExecutor,  Up: concurrent futures — Launching parallel tasks

5.18.5.4 InterpreterPoolExecutor
................................

Added in version 3.14.

The *note InterpreterPoolExecutor: 1d2. class uses a pool of
interpreters to execute calls asynchronously.  It is a *note
ThreadPoolExecutor: 94a. subclass, which means each worker is running in
its own thread.  The difference here is that each worker has its own
interpreter, and runs each task using that interpreter.

The biggest benefit to using interpreters instead of only threads is
true multi-core parallelism.  Each interpreter has its own *note Global
Interpreter Lock: 474, so code running in one interpreter can run on one
CPU core, while code in another interpreter runs unblocked on a
different core.

The tradeoff is that writing concurrent code for use with multiple
interpreters can take extra effort.  However, this is because it forces
you to be deliberate about how and when interpreters interact, and to be
explicit about what data is shared between interpreters.  This results
in several benefits that help balance the extra effort, including true
multi-core parallelism, For example, code written this way can make it
easier to reason about concurrency.  Another major benefit is that you
don’t have to deal with several of the big pain points of using threads,
like race conditions.

Each worker’s interpreter is isolated from all the other interpreters.
«Isolated» means each interpreter has its own runtime state and operates
completely independently.  For example, if you redirect *note
sys.stdout: ccf. in one interpreter, it will not be automatically
redirected to any other interpreter.  If you import a module in one
interpreter, it is not automatically imported in any other.  You would
need to import the module separately in interpreter where you need it.
In fact, each module imported in an interpreter is a completely separate
object from the same module in a different interpreter, including *note
sys: df, *note builtins: 13, and even ‘__main__’.

Isolation means a mutable object, or other data, cannot be used by more
than one interpreter at the same time.  That effectively means
interpreters cannot actually share such objects or data.  Instead, each
interpreter must have its own copy, and you will have to synchronize any
changes between the copies manually.  Immutable objects and data, like
the builtin singletons, strings, and tuples of immutable objects, don’t
have these limitations.

Communicating and synchronizing between interpreters is most effectively
done using dedicated tools, like those proposed in PEP 734(1).  One less
efficient alternative is to serialize with *note pickle: ab. and then
send the bytes over a shared *note socket: d1. or *note pipe: 1b4c.

 -- Classe: concurrent.futures.InterpreterPoolExecutor
          (max_workers=None, thread_name_prefix='', initializer=None,
          initargs=())

     A *note ThreadPoolExecutor: 94a. subclass that executes calls
     asynchronously using a pool of at most 'max_workers' threads.  Each
     thread runs tasks in its own interpreter.  The worker interpreters
     are isolated from each other, which means each has its own runtime
     state and that they can’t share any mutable objects or other data.
     Each interpreter has its own *note Global Interpreter Lock: 474,
     which means code run with this executor has true multi-core
     parallelism.

     The optional 'initializer' and 'initargs' arguments have the same
     meaning as for ‘ThreadPoolExecutor’: the initializer is run when
     each worker is created, though in this case it is run in the
     worker’s interpreter.  The executor serializes the 'initializer'
     and 'initargs' using *note pickle: ab. when sending them to the
     worker’s interpreter.

          Nota: The executor may replace uncaught exceptions from
          'initializer' with *note ExecutionFailed: 36cf.

     Other caveats from parent *note ThreadPoolExecutor: 94a. apply
     here.

*note submit(): c77. and *note map(): 1dc. work like normal, except the
worker serializes the callable and arguments using *note pickle: ab.
when sending them to its interpreter.  The worker likewise serializes
the return value when sending it back.

When a worker’s current task raises an uncaught exception, the worker
always tries to preserve the exception as-is.  If that is successful
then it also sets the ‘__cause__’ to a corresponding *note
ExecutionFailed: 36cf. instance, which contains a summary of the
original exception.  In the uncommon case that the worker is not able to
preserve the original as-is then it directly preserves the corresponding
*note ExecutionFailed: 36cf. instance instead.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0734/


File: python.info,  Node: ProcessPoolExecutor,  Next: Future Objects,  Prev: InterpreterPoolExecutor,  Up: concurrent futures — Launching parallel tasks

5.18.5.5 ProcessPoolExecutor
............................

The *note ProcessPoolExecutor: 1d6. class is an *note Executor: 36c8.
subclass that uses a pool of processes to execute calls asynchronously.
*note ProcessPoolExecutor: 1d6. uses the *note multiprocessing: 98.
module, which allows it to side-step the *note Global Interpreter Lock:
474. but also means that only picklable objects can be executed and
returned.

The ‘__main__’ module must be importable by worker subprocesses.  This
means that *note ProcessPoolExecutor: 1d6. will not work in the
interactive interpreter.

Calling *note Executor: 36c8. or *note Future: 13ba. methods from a
callable submitted to a *note ProcessPoolExecutor: 1d6. will result in
deadlock.

Note that the restrictions on functions and arguments needing to
picklable as per *note multiprocessing.Process: 252. apply when using
*note submit(): c77. and *note map(): 1dc. on a *note
ProcessPoolExecutor: 1d6.  A function defined in a REPL or a lambda
should not be expected to work.

 -- Classe: concurrent.futures.ProcessPoolExecutor (max_workers=None,
          mp_context=None, initializer=None, initargs=(),
          max_tasks_per_child=None)

     An *note Executor: 36c8. subclass that executes calls
     asynchronously using a pool of at most 'max_workers' processes.  If
     'max_workers' is ‘None’ or not given, it will default to *note
     os.process_cpu_count(): 4db.  If 'max_workers' is less than or
     equal to ‘0’, then a *note ValueError: 2ec. will be raised.  On
     Windows, 'max_workers' must be less than or equal to ‘61’.  If it
     is not then *note ValueError: 2ec. will be raised.  If
     'max_workers' is ‘None’, then the default chosen will be at most
     ‘61’, even if more processors are available.  'mp_context' can be a
     *note multiprocessing: 98. context or ‘None’.  It will be used to
     launch the workers.  If 'mp_context' is ‘None’ or not given, the
     default *note multiprocessing: 98. context is used.  See *note
     Contexts and start methods: 1d5.

     'initializer' is an optional callable that is called at the start
     of each worker process; 'initargs' is a tuple of arguments passed
     to the initializer.  Should 'initializer' raise an exception, all
     currently pending jobs will raise a *note BrokenProcessPool: 36d1,
     as well as any attempt to submit more jobs to the pool.

     'max_tasks_per_child' is an optional argument that specifies the
     maximum number of tasks a single process can execute before it will
     exit and be replaced with a fresh worker process.  By default
     'max_tasks_per_child' is ‘None’ which means worker processes will
     live as long as the pool.  When a max is specified, the «spawn»
     multiprocessing start method will be used by default in absence of
     a 'mp_context' parameter.  This feature is incompatible with the
     «fork» start method.

          Nota: Bugs have been reported when using the
          'max_tasks_per_child' feature that can result in the *note
          ProcessPoolExecutor: 1d6. hanging in some circumstances.
          Follow its eventual resolution in gh-115634(1).

     Cambiato nella versione 3.3: When one of the worker processes
     terminates abruptly, a *note BrokenProcessPool: 36d1. error is now
     raised.  Previously, behaviour was undefined but operations on the
     executor or its futures would often freeze or deadlock.

     Cambiato nella versione 3.7: The 'mp_context' argument was added to
     allow users to control the start_method for worker processes
     created by the pool.

     Added the 'initializer' and 'initargs' arguments.

     Cambiato nella versione 3.11: The 'max_tasks_per_child' argument
     was added to allow users to control the lifetime of workers in the
     pool.

     Cambiato nella versione 3.12: On POSIX systems, if your application
     has multiple threads and the *note multiprocessing: 98. context
     uses the ‘"fork"’ start method: The *note os.fork(): 4b6. function
     called internally to spawn workers may raise a *note
     DeprecationWarning: 1a3.  Pass a 'mp_context' configured to use a
     different start method.  See the *note os.fork(): 4b6.
     documentation for further explanation.

     Cambiato nella versione 3.13: 'max_workers' uses *note
     os.process_cpu_count(): 4db. by default, instead of *note
     os.cpu_count(): 4dc.

     Cambiato nella versione 3.14: The default process start method (see
     *note Contexts and start methods: 1d5.) changed away from 'fork'.
     If you require the 'fork' start method for *note
     ProcessPoolExecutor: 1d6. you must explicitly pass
     ‘mp_context=multiprocessing.get_context("fork")’.

      -- Metodo: terminate_workers ()

          Attempt to terminate all living worker processes immediately
          by calling *note Process.terminate: 183f. on each of them.
          Internally, it will also call *note Executor.shutdown(): aec.
          to ensure that all other resources associated with the
          executor are freed.

          After calling this method the caller should no longer submit
          tasks to the executor.

          Added in version 3.14.

      -- Metodo: kill_workers ()

          Attempt to kill all living worker processes immediately by
          calling *note Process.kill: d51. on each of them.  Internally,
          it will also call *note Executor.shutdown(): aec. to ensure
          that all other resources associated with the executor are
          freed.

          After calling this method the caller should no longer submit
          tasks to the executor.

          Added in version 3.14.

* Menu:

* ProcessPoolExecutor Example::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/115634


File: python.info,  Node: ProcessPoolExecutor Example,  Up: ProcessPoolExecutor

5.18.5.6 ProcessPoolExecutor Example
....................................

     import concurrent.futures
     import math

     PRIMES = [
         112272535095293,
         112582705942171,
         112272535095293,
         115280095190773,
         115797848077099,
         1099726899285419]

     def is_prime(n):
         if n < 2:
             return False
         if n == 2:
             return True
         if n % 2 == 0:
             return False

         sqrt_n = int(math.floor(math.sqrt(n)))
         for i in range(3, sqrt_n + 1, 2):
             if n % i == 0:
                 return False
         return True

     def main():
         with concurrent.futures.ProcessPoolExecutor() as executor:
             for number, prime in zip(PRIMES, executor.map(is_prime, PRIMES)):
                 print('%d is prime: %s' % (number, prime))

     if __name__ == '__main__':
         main()


File: python.info,  Node: Future Objects,  Next: Module Functions,  Prev: ProcessPoolExecutor,  Up: concurrent futures — Launching parallel tasks

5.18.5.7 Future Objects
.......................

The *note Future: 13ba. class encapsulates the asynchronous execution of
a callable.  *note Future: 13ba. instances are created by *note
Executor.submit(): c77.

 -- Classe: concurrent.futures.Future

     Encapsulates the asynchronous execution of a callable.  *note
     Future: 13ba. instances are created by *note Executor.submit():
     c77. and should not be created directly except for testing.

      -- Metodo: cancel ()

          Attempt to cancel the call.  If the call is currently being
          executed or finished running and cannot be cancelled then the
          method will return ‘False’, otherwise the call will be
          cancelled and the method will return ‘True’.

      -- Metodo: cancelled ()

          Return ‘True’ if the call was successfully cancelled.

      -- Metodo: running ()

          Return ‘True’ if the call is currently being executed and
          cannot be cancelled.

      -- Metodo: done ()

          Return ‘True’ if the call was successfully cancelled or
          finished running.

      -- Metodo: result (timeout=None)

          Return the value returned by the call.  If the call hasn’t yet
          completed then this method will wait up to 'timeout' seconds.
          If the call hasn’t completed in 'timeout' seconds, then a
          *note TimeoutError: a38. will be raised.  'timeout' can be an
          int or float.  If 'timeout' is not specified or ‘None’, there
          is no limit to the wait time.

          If the future is cancelled before completing then *note
          CancelledError: bd0. will be raised.

          If the call raised an exception, this method will raise the
          same exception.

      -- Metodo: exception (timeout=None)

          Return the exception raised by the call.  If the call hasn’t
          yet completed then this method will wait up to 'timeout'
          seconds.  If the call hasn’t completed in 'timeout' seconds,
          then a *note TimeoutError: a38. will be raised.  'timeout' can
          be an int or float.  If 'timeout' is not specified or ‘None’,
          there is no limit to the wait time.

          If the future is cancelled before completing then *note
          CancelledError: bd0. will be raised.

          If the call completed without raising, ‘None’ is returned.

      -- Metodo: add_done_callback (fn)

          Attaches the callable 'fn' to the future.  'fn' will be
          called, with the future as its only argument, when the future
          is cancelled or finishes running.

          Added callables are called in the order that they were added
          and are always called in a thread belonging to the process
          that added them.  If the callable raises an *note Exception:
          bcf. subclass, it will be logged and ignored.  If the callable
          raises a *note BaseException: 7d8. subclass, the behavior is
          undefined.

          If the future has already completed or been cancelled, 'fn'
          will be called immediately.

     The following *note Future: 13ba. methods are meant for use in unit
     tests and *note Executor: 36c8. implementations.

      -- Metodo: set_running_or_notify_cancel ()

          This method should only be called by *note Executor: 36c8.
          implementations before executing the work associated with the
          *note Future: 13ba. and by unit tests.

          If the method returns ‘False’ then the *note Future: 13ba. was
          cancelled, i.e.  *note Future.cancel(): 36d4. was called and
          returned ‘True’.  Any threads waiting on the *note Future:
          13ba. completing (i.e.  through *note as_completed(): 19af. or
          *note wait(): 1bed.) will be woken up.

          If the method returns ‘True’ then the *note Future: 13ba. was
          not cancelled and has been put in the running state, i.e.
          calls to *note Future.running(): 36d6. will return ‘True’.

          This method can only be called once and cannot be called after
          *note Future.set_result(): 36dc. or *note
          Future.set_exception(): 36dd. have been called.

      -- Metodo: set_result (result)

          Sets the result of the work associated with the *note Future:
          13ba. to 'result'.

          This method should only be used by *note Executor: 36c8.
          implementations and unit tests.

          Cambiato nella versione 3.8: This method raises *note
          concurrent.futures.InvalidStateError: 1939. if the *note
          Future: 13ba. is already done.

      -- Metodo: set_exception (exception)

          Sets the result of the work associated with the *note Future:
          13ba. to the *note Exception: bcf. 'exception'.

          This method should only be used by *note Executor: 36c8.
          implementations and unit tests.

          Cambiato nella versione 3.8: This method raises *note
          concurrent.futures.InvalidStateError: 1939. if the *note
          Future: 13ba. is already done.


File: python.info,  Node: Module Functions,  Next: Exception classes,  Prev: Future Objects,  Up: concurrent futures — Launching parallel tasks

5.18.5.8 Module Functions
.........................

 -- Funzione: concurrent.futures.wait (fs, timeout=None,
          return_when=ALL_COMPLETED)

     Wait for the *note Future: 13ba. instances (possibly created by
     different *note Executor: 36c8. instances) given by 'fs' to
     complete.  Duplicate futures given to 'fs' are removed and will be
     returned only once.  Returns a named 2-tuple of sets.  The first
     set, named ‘done’, contains the futures that completed (finished or
     cancelled futures) before the wait completed.  The second set,
     named ‘not_done’, contains the futures that did not complete
     (pending or running futures).

     'timeout' can be used to control the maximum number of seconds to
     wait before returning.  'timeout' can be an int or float.  If
     'timeout' is not specified or ‘None’, there is no limit to the wait
     time.

     'return_when' indicates when this function should return.  It must
     be one of the following constants:

     Constant                                               Description
                                                            
     --------------------------------------------------------------------------------------------------------------
                                                            
      -- Dati: concurrent.futures.FIRST_COMPLETED           The function will return when any future finishes or
                                                            is cancelled.
                                                            
                                                            
      -- Dati: concurrent.futures.FIRST_EXCEPTION           The function will return when any future finishes by
                                                            raising an exception.  If no future raises an
                                                            exception then it is equivalent to
                                                            *note ALL_COMPLETED: 36e1.
                                                            
                                                            
      -- Dati: concurrent.futures.ALL_COMPLETED             The function will return when all futures finish or
                                                            are cancelled.
                                                            

 -- Funzione: concurrent.futures.as_completed (fs, timeout=None)

     Returns an iterator over the *note Future: 13ba. instances
     (possibly created by different *note Executor: 36c8. instances)
     given by 'fs' that yields futures as they complete (finished or
     cancelled futures).  Any futures given by 'fs' that are duplicated
     will be returned once.  Any futures that completed before *note
     as_completed(): 19af. is called will be yielded first.  The
     returned iterator raises a *note TimeoutError: a38. if *note
     __next__(): 14d5. is called and the result isn’t available after
     'timeout' seconds from the original call to *note as_completed():
     19af.  'timeout' can be an int or float.  If 'timeout' is not
     specified or ‘None’, there is no limit to the wait time.

Vedi anche
..........

PEP 3148(1) – futures - execute computations asynchronously

     The proposal which described this feature for inclusion in the
     Python standard library.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3148/


File: python.info,  Node: Exception classes,  Prev: Module Functions,  Up: concurrent futures — Launching parallel tasks

5.18.5.9 Exception classes
..........................

 -- Eccezione: concurrent.futures.CancelledError

     Raised when a future is cancelled.

 -- Eccezione: concurrent.futures.TimeoutError

     A deprecated alias of *note TimeoutError: a38, raised when a future
     operation exceeds the given timeout.

     Cambiato nella versione 3.11: This class was made an alias of *note
     TimeoutError: a38.

 -- Eccezione: concurrent.futures.BrokenExecutor

     Derived from *note RuntimeError: 244, this exception class is
     raised when an executor is broken for some reason, and cannot be
     used to submit or execute new tasks.

     Added in version 3.7.

 -- Eccezione: concurrent.futures.InvalidStateError

     Raised when an operation is performed on a future that is not
     allowed in the current state.

     Added in version 3.8.

 -- Eccezione: concurrent.futures.thread.BrokenThreadPool

     Derived from *note BrokenExecutor: 36e4, this exception class is
     raised when one of the workers of a *note ThreadPoolExecutor: 94a.
     has failed initializing.

     Added in version 3.7.

 -- Eccezione: concurrent.futures.interpreter.BrokenInterpreterPool

     Derived from *note BrokenThreadPool: 36cc, this exception class is
     raised when one of the workers of a *note InterpreterPoolExecutor:
     1d2. has failed initializing.

     Added in version 3.14.

 -- Eccezione: concurrent.futures.process.BrokenProcessPool

     Derived from *note BrokenExecutor: 36e4. (formerly *note
     RuntimeError: 244.), this exception class is raised when one of the
     workers of a *note ProcessPoolExecutor: 1d6. has terminated in a
     non-clean fashion (for example, if it was killed from the outside).

     Added in version 3.3.


File: python.info,  Node: concurrent interpreters — Multiple interpreters in the same process,  Next: subprocess — Subprocess management,  Prev: concurrent futures — Launching parallel tasks,  Up: Concurrent Execution

5.18.6 ‘concurrent.interpreters’ — Multiple interpreters in the same process
----------------------------------------------------------------------------

Added in version 3.14.

'Source code:' Lib/concurrent/interpreters(1)

__________________________________________________________________

The ‘concurrent.interpreters’ module constructs higher-level interfaces
on top of the lower level ‘_interpreters’ module.

The module is primarily meant to provide a basic API for managing
interpreters (AKA «subinterpreters») and running things in them.
Running mostly involves switching to an interpreter (in the current
thread) and calling a function in that execution context.

For concurrency, interpreters themselves (and this module) don’t provide
much more than isolation, which on its own isn’t useful.  Actual
concurrency is available separately through *note threads: f3. See *note
below: 36e9.

Vedi anche
..........

*note InterpreterPoolExecutor: 1d2.

     Combines threads with interpreters in a familiar interface.

*note Isolating Extension Modules: 166.

     How to update an extension module to support multiple interpreters.

PEP 554(2)

PEP 734(3)

PEP 684(4)

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

* Menu:

* Key details::
* Introduction: Introduction<9>.
* Reference: Reference<4>.
* Basic usage::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/concurrent/interpreters

   (2) https://peps.python.org/pep-0554/

   (3) https://peps.python.org/pep-0734/

   (4) https://peps.python.org/pep-0684/


File: python.info,  Node: Key details,  Next: Introduction<9>,  Up: concurrent interpreters — Multiple interpreters in the same process

5.18.6.1 Key details
....................

Before we dive in further, there are a small number of details to keep
in mind about using multiple interpreters:

   * *note isolated: 36eb., by default

   * no implicit threads

   * not all PyPI packages support use in multiple interpreters yet


File: python.info,  Node: Introduction<9>,  Next: Reference<4>,  Prev: Key details,  Up: concurrent interpreters — Multiple interpreters in the same process

5.18.6.2 Introduction
.....................

An «interpreter» is effectively the execution context of the Python
runtime.  It contains all of the state the runtime needs to execute a
program.  This includes things like the import state and builtins.
(Each thread, even if there’s only the main thread, has some extra
runtime state, in addition to the current interpreter, related to the
current exception and the bytecode eval loop.)

The concept and functionality of the interpreter have been a part of
Python since version 2.2, but the feature was only available through the
C-API and not well known, and the *note isolation: 36eb. was relatively
incomplete until version 3.12.

* Menu:

* Multiple Interpreters and Isolation::
* Running in an Interpreter::
* Concurrency and Parallelism::
* Communication Between Interpreters::
* «Sharing» Objects::


File: python.info,  Node: Multiple Interpreters and Isolation,  Next: Running in an Interpreter,  Up: Introduction<9>

5.18.6.3 Multiple Interpreters and Isolation
............................................

A Python implementation may support using multiple interpreters in the
same process.  CPython has this support.  Each interpreter is
effectively isolated from the others (with a limited number of carefully
managed process-global exceptions to the rule).

That isolation is primarily useful as a strong separation between
distinct logical components of a program, where you want to have careful
control of how those components interact.

     Nota: Interpreters in the same process can technically never be
     strictly isolated from one another since there are few restrictions
     on memory access within the same process.  The Python runtime makes
     a best effort at isolation but extension modules may easily violate
     that.  Therefore, do not use multiple interpreters in
     security-sensitive situations, where they shouldn’t have access to
     each other’s data.


File: python.info,  Node: Running in an Interpreter,  Next: Concurrency and Parallelism,  Prev: Multiple Interpreters and Isolation,  Up: Introduction<9>

5.18.6.4 Running in an Interpreter
..................................

Running in a different interpreter involves switching to it in the
current thread and then calling some function.  The runtime will execute
the function using the current interpreter’s state.  The
‘concurrent.interpreters’ module provides a basic API for creating and
managing interpreters, as well as the switch-and-call operation.

No other threads are automatically started for the operation.  There is
*note a helper: 36f0.for that though.  There is another dedicated helper
for calling the builtin *note exec(): 4a3. in an interpreter.

When *note exec(): 4a3. (or *note eval(): 4a4.) are called in an
interpreter, they run using the interpreter’s ‘__main__’ module as the
«globals» namespace.  The same is true for functions that aren’t
associated with any module.  This is the same as how scripts invoked
from the command-line run in the ‘__main__’ module.


File: python.info,  Node: Concurrency and Parallelism,  Next: Communication Between Interpreters,  Prev: Running in an Interpreter,  Up: Introduction<9>

5.18.6.5 Concurrency and Parallelism
....................................

As noted earlier, interpreters do not provide any concurrency on their
own.  They strictly represent the isolated execution context the runtime
will use 'in the current thread'.  That isolation makes them similar to
processes, but they still enjoy in-process efficiency, like threads.

All that said, interpreters do naturally support certain flavors of
concurrency.  There’s a powerful side effect of that isolation.  It
enables a different approach to concurrency than you can take with async
or threads.  It’s a similar concurrency model to CSP or the actor model,
a model which is relatively easy to reason about.

You can take advantage of that concurrency model in a single thread,
switching back and forth between interpreters, Stackless-style.
However, this model is more useful when you combine interpreters with
multiple threads.  This mostly involves starting a new thread, where you
switch to another interpreter and run what you want there.

Each actual thread in Python, even if you’re only running in the main
thread, has its own 'current' execution context.  Multiple threads can
use the same interpreter or different ones.

At a high level, you can think of the combination of threads and
interpreters as threads with opt-in sharing.

As a significant bonus, interpreters are sufficiently isolated that they
do not share the *note GIL: 164, which means combining threads with
multiple interpreters enables full multi-core parallelism.  (This has
been the case since Python 3.12.)


File: python.info,  Node: Communication Between Interpreters,  Next: «Sharing» Objects,  Prev: Concurrency and Parallelism,  Up: Introduction<9>

5.18.6.6 Communication Between Interpreters
...........................................

In practice, multiple interpreters are useful only if we have a way to
communicate between them.  This usually involves some form of message
passing, but can even mean sharing data in some carefully managed way.

With this in mind, the ‘concurrent.interpreters’ module provides a *note
queue.Queue: 159c. implementation, available through *note
create_queue(): 36f3.


File: python.info,  Node: «Sharing» Objects,  Prev: Communication Between Interpreters,  Up: Introduction<9>

5.18.6.7 «Sharing» Objects
..........................

Any data actually shared between interpreters loses the thread-safety
provided by the *note GIL: 164.  There are various options for dealing
with this in extension modules.  However, from Python code the lack of
thread-safety means objects can’t actually be shared, with a few
exceptions.  Instead, a copy must be created, which means mutable
objects won’t stay in sync.

By default, most objects are copied with *note pickle: ab. when they are
passed to another interpreter.  Nearly all of the immutable builtin
objects are either directly shared or copied efficiently.  For example:

   * *note None: 886.

   * *note bool: 3c3. (*note True: e09. and *note False: d2d.)

   * *note bytes: 192.

   * *note str: 169.

   * *note int: 19b.

   * *note float: 196.

   * *note tuple: 614. (of similarly supported objects)

There is a small number of Python types that actually share mutable data
between interpreters:

   * *note memoryview: 165.

   * *note Queue: 36f6.


File: python.info,  Node: Reference<4>,  Next: Basic usage,  Prev: Introduction<9>,  Up: concurrent interpreters — Multiple interpreters in the same process

5.18.6.8 Reference
..................

This module defines the following functions:

 -- Funzione: concurrent.interpreters.list_all ()

     Return a *note list: 24d. of *note Interpreter: 36f9. objects, one
     for each existing interpreter.

 -- Funzione: concurrent.interpreters.get_current ()

     Return an *note Interpreter: 36f9. object for the currently running
     interpreter.

 -- Funzione: concurrent.interpreters.get_main ()

     Return an *note Interpreter: 36f9. object for the main interpreter.
     This is the interpreter the runtime created to run the *note REPL:
     492. or the script given at the command-line.  It is usually the
     only one.

 -- Funzione: concurrent.interpreters.create ()

     Initialize a new (idle) Python interpreter and return a *note
     Interpreter: 36f9. object for it.

 -- Funzione: concurrent.interpreters.create_queue ()

     Initialize a new cross-interpreter queue and return a *note Queue:
     36f6. object for it.

* Menu:

* Interpreter objects::
* Exceptions: Exceptions<12>.
* Communicating Between Interpreters::


File: python.info,  Node: Interpreter objects,  Next: Exceptions<12>,  Up: Reference<4>

5.18.6.9 Interpreter objects
............................

 -- Classe: concurrent.interpreters.Interpreter (id)

     A single interpreter in the current process.

     Generally, *note Interpreter: 36f9. shouldn’t be called directly.
     Instead, use *note create(): 17a4. or one of the other module
     functions.

      -- Attributo: id

          (read-only)

          The underlying interpreter’s ID.

      -- Attributo: whence

          (read-only)

          A string describing where the interpreter came from.

      -- Metodo: is_running ()

          Return ‘True’ if the interpreter is currently executing code
          in its ‘__main__’ module and ‘False’ otherwise.

      -- Metodo: close ()

          Finalize and destroy the interpreter.

      -- Metodo: prepare_main (ns=None, **kwargs)

          Bind objects in the interpreter’s ‘__main__’ module.

          Some objects are actually shared and some are copied
          efficiently, but most are copied via *note pickle: ab.  See
          *note «Sharing» Objects: 36f4.

      -- Metodo: exec (code, /, dedent=True)

          Run the given source code in the interpreter (in the current
          thread).

      -- Metodo: call (callable, /, *args, **kwargs)

          Return the result of calling running the given function in the
          interpreter (in the current thread).

      -- Metodo: call_in_thread (callable, /, *args, **kwargs)

          Run the given function in the interpreter (in a new thread).


File: python.info,  Node: Exceptions<12>,  Next: Communicating Between Interpreters,  Prev: Interpreter objects,  Up: Reference<4>

5.18.6.10 Exceptions
....................

 -- Eccezione: concurrent.interpreters.InterpreterError

     This exception, a subclass of *note Exception: bcf, is raised when
     an interpreter-related error happens.

 -- Eccezione: concurrent.interpreters.InterpreterNotFoundError

     This exception, a subclass of *note InterpreterError: 3705, is
     raised when the targeted interpreter no longer exists.

 -- Eccezione: concurrent.interpreters.ExecutionFailed

     This exception, a subclass of *note InterpreterError: 3705, is
     raised when the running code raised an uncaught exception.

      -- Attributo: excinfo

          A basic snapshot of the exception raised in the other
          interpreter.

 -- Eccezione: concurrent.interpreters.NotShareableError

     This exception, a subclass of *note TypeError: 198, is raised when
     an object cannot be sent to another interpreter.


File: python.info,  Node: Communicating Between Interpreters,  Prev: Exceptions<12>,  Up: Reference<4>

5.18.6.11 Communicating Between Interpreters
............................................

 -- Classe: concurrent.interpreters.Queue (id)

     A wrapper around a low-level, cross-interpreter queue, which
     implements the *note queue.Queue: 159c. interface.  The underlying
     queue can only be created through *note create_queue(): 36f3.

     Some objects are actually shared and some are copied efficiently,
     but most are copied via *note pickle: ab.  See *note «Sharing»
     Objects: 36f4.

      -- Attributo: id

          (read-only)

          The queue’s ID.

 -- Eccezione: concurrent.interpreters.QueueEmptyError

     This exception, a subclass of *note queue.Empty: 3652, is raised
     from ‘Queue.get()’ and ‘Queue.get_nowait()’ when the queue is
     empty.

 -- Eccezione: concurrent.interpreters.QueueFullError

     This exception, a subclass of *note queue.Full: 3653, is raised
     from ‘Queue.put()’ and ‘Queue.put_nowait()’ when the queue is full.


File: python.info,  Node: Basic usage,  Prev: Reference<4>,  Up: concurrent interpreters — Multiple interpreters in the same process

5.18.6.12 Basic usage
.....................

Creating an interpreter and running code in it:

     from concurrent import interpreters

     interp = interpreters.create()

     # Run in the current OS thread.

     interp.exec('print("spam!")')

     interp.exec("""if True:
         print('spam!')
         """)

     from textwrap import dedent
     interp.exec(dedent("""
         print('spam!')
         """))

     def run(arg):
         return arg

     res = interp.call(run, 'spam!')
     print(res)

     def run():
         print('spam!')

     interp.call(run)

     # Run in new OS thread.

     t = interp.call_in_thread(run)
     t.join()


File: python.info,  Node: subprocess — Subprocess management,  Next: sched — Event scheduler,  Prev: concurrent interpreters — Multiple interpreters in the same process,  Up: Concurrent Execution

5.18.7 ‘subprocess’ — Subprocess management
-------------------------------------------

'Source code:' Lib/subprocess.py(1)

__________________________________________________________________

The *note subprocess: dc. module allows you to spawn new processes,
connect to their input/output/error pipes, and obtain their return
codes.  This module intends to replace several older modules and
functions:

     os.system
     os.spawn*

Information about how the *note subprocess: dc. module can be used to
replace these modules and functions can be found in the following
sections.

Vedi anche
..........

PEP 324(2) – PEP proposing the subprocess module

*note Availability: 2128.: not Android, not iOS, not WASI.

This module is not supported on *note mobile platforms: 2245. or *note
WebAssembly platforms: 1b52.

* Menu:

* Using the subprocess Module::
* Security Considerations::
* Popen Objects::
* Windows Popen Helpers::
* Older high-level API::
* Replacing Older Functions with the subprocess Module::
* Legacy Shell Invocation Functions::
* Notes: Notes<2>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/subprocess.py

   (2) https://peps.python.org/pep-0324/


File: python.info,  Node: Using the subprocess Module,  Next: Security Considerations,  Up: subprocess — Subprocess management

5.18.7.1 Using the ‘subprocess’ Module
......................................

The recommended approach to invoking subprocesses is to use the *note
run(): d81. function for all use cases it can handle.  For more advanced
use cases, the underlying *note Popen: 4b8. interface can be used
directly.

 -- Funzione: subprocess.run (args, *, stdin=None, input=None,
          stdout=None, stderr=None, capture_output=False, shell=False,
          cwd=None, timeout=None, check=False, encoding=None,
          errors=None, text=None, env=None, universal_newlines=None,
          **other_popen_kwargs)

     Run the command described by 'args'.  Wait for command to complete,
     then return a *note CompletedProcess: 1075. instance.

     The arguments shown above are merely the most common ones,
     described below in *note Frequently Used Arguments: 3712. (hence
     the use of keyword-only notation in the abbreviated signature).
     The full function signature is largely the same as that of the
     *note Popen: 4b8. constructor - most of the arguments to this
     function are passed through to that interface.  ('timeout',
     'input', 'check', and 'capture_output' are not.)

     If 'capture_output' is true, stdout and stderr will be captured.
     When used, the internal *note Popen: 4b8. object is automatically
     created with 'stdout' and 'stderr' both set to *note PIPE: d82.
     The 'stdout' and 'stderr' arguments may not be supplied at the same
     time as 'capture_output'.  If you wish to capture and combine both
     streams into one, set 'stdout' to *note PIPE: d82. and 'stderr' to
     *note STDOUT: 3713, instead of using 'capture_output'.

     A 'timeout' may be specified in seconds, it is internally passed on
     to *note Popen.communicate(): 1792.  If the timeout expires, the
     child process will be killed and waited for.  The *note
     TimeoutExpired: 1793. exception will be re-raised after the child
     process has terminated.  The initial process creation itself cannot
     be interrupted on many platform APIs so you are not guaranteed to
     see a timeout exception until at least after however long process
     creation takes.

     The 'input' argument is passed to *note Popen.communicate(): 1792.
     and thus to the subprocess’s stdin.  If used it must be a byte
     sequence, or a string if 'encoding' or 'errors' is specified or
     'text' is true.  When used, the internal *note Popen: 4b8. object
     is automatically created with 'stdin' set to *note PIPE: d82, and
     the 'stdin' argument may not be used as well.

     If 'check' is true, and the process exits with a non-zero exit
     code, a *note CalledProcessError: 152c. exception will be raised.
     Attributes of that exception hold the arguments, the exit code, and
     stdout and stderr if they were captured.

     If 'encoding' or 'errors' are specified, or 'text' is true, file
     objects for stdin, stdout and stderr are opened in text mode using
     the specified 'encoding' and 'errors' or the *note
     io.TextIOWrapper: 9c0. default.  The 'universal_newlines' argument
     is equivalent to 'text' and is provided for backwards
     compatibility.  By default, file objects are opened in binary mode.

     If 'env' is not ‘None’, it must be a mapping that defines the
     environment variables for the new process; these are used instead
     of the default behavior of inheriting the current process”
     environment.  It is passed directly to *note Popen: 4b8.  This
     mapping can be str to str on any platform or bytes to bytes on
     POSIX platforms much like *note os.environ: 259. or *note
     os.environb: 25a.

     Examples:

          >>> subprocess.run(["ls", "-l"])  # doesn't capture output
          CompletedProcess(args=['ls', '-l'], returncode=0)

          >>> subprocess.run("exit 1", shell=True, check=True)
          Traceback (most recent call last):
            ...
          subprocess.CalledProcessError: Command 'exit 1' returned non-zero exit status 1

          >>> subprocess.run(["ls", "-l", "/dev/null"], capture_output=True)
          CompletedProcess(args=['ls', '-l', '/dev/null'], returncode=0,
          stdout=b'crw-rw-rw- 1 root root 1, 3 Jan 23 16:23 /dev/null\n', stderr=b'')

     Added in version 3.5.

     Cambiato nella versione 3.6: Added 'encoding' and 'errors'
     parameters

     Cambiato nella versione 3.7: Added the 'text' parameter, as a more
     understandable alias of 'universal_newlines'.  Added the
     'capture_output' parameter.

     Cambiato nella versione 3.12: Changed Windows shell search order
     for ‘shell=True’.  The current directory and ‘%PATH%’ are replaced
     with ‘%COMSPEC%’ and ‘%SystemRoot%\System32\cmd.exe’.  As a result,
     dropping a malicious program named ‘cmd.exe’ into a current
     directory no longer works.

 -- Classe: subprocess.CompletedProcess

     The return value from *note run(): d81, representing a process that
     has finished.

      -- Attributo: args

          The arguments used to launch the process.  This may be a list
          or a string.

      -- Attributo: returncode

          Exit status of the child process.  Typically, an exit status
          of 0 indicates that it ran successfully.

          A negative value ‘-N’ indicates that the child was terminated
          by signal ‘N’ (POSIX only).

      -- Attributo: stdout

          Captured stdout from the child process.  A bytes sequence, or
          a string if *note run(): d81. was called with an encoding,
          errors, or text=True.  ‘None’ if stdout was not captured.

          If you ran the process with ‘stderr=subprocess.STDOUT’, stdout
          and stderr will be combined in this attribute, and *note
          stderr: 3717. will be ‘None’.

      -- Attributo: stderr

          Captured stderr from the child process.  A bytes sequence, or
          a string if *note run(): d81. was called with an encoding,
          errors, or text=True.  ‘None’ if stderr was not captured.

      -- Metodo: check_returncode ()

          If *note returncode: 3715. is non-zero, raise a *note
          CalledProcessError: 152c.

     Added in version 3.5.

 -- Dati: subprocess.DEVNULL

     Special value that can be used as the 'stdin', 'stdout' or 'stderr'
     argument to *note Popen: 4b8. and indicates that the special file
     *note os.devnull: 1dfc. will be used.

     Added in version 3.3.

 -- Dati: subprocess.PIPE

     Special value that can be used as the 'stdin', 'stdout' or 'stderr'
     argument to *note Popen: 4b8. and indicates that a pipe to the
     standard stream should be opened.  Most useful with *note
     Popen.communicate(): 1792.

 -- Dati: subprocess.STDOUT

     Special value that can be used as the 'stderr' argument to *note
     Popen: 4b8. and indicates that standard error should go into the
     same handle as standard output.

 -- Eccezione: subprocess.SubprocessError

     Base class for all other exceptions from this module.

     Added in version 3.3.

 -- Eccezione: subprocess.TimeoutExpired

     Subclass of *note SubprocessError: 3719, raised when a timeout
     expires while waiting for a child process.

      -- Attributo: cmd

          Command that was used to spawn the child process.

      -- Attributo: timeout

          Timeout in seconds.

      -- Attributo: output

          Output of the child process if it was captured by *note run():
          d81. or *note check_output(): 11c4.  Otherwise, ‘None’.  This
          is always *note bytes: 192. when any output was captured
          regardless of the ‘text=True’ setting.  It may remain ‘None’
          instead of ‘b''’ when no output was observed.

      -- Attributo: stdout

          Alias for output, for symmetry with *note stderr: 371e.

      -- Attributo: stderr

          Stderr output of the child process if it was captured by *note
          run(): d81.  Otherwise, ‘None’.  This is always *note bytes:
          192. when stderr output was captured regardless of the
          ‘text=True’ setting.  It may remain ‘None’ instead of ‘b''’
          when no stderr output was observed.

     Added in version 3.3.

     Cambiato nella versione 3.5: 'stdout' and 'stderr' attributes added

 -- Eccezione: subprocess.CalledProcessError

     Subclass of *note SubprocessError: 3719, raised when a process run
     by *note check_call(): 371f, *note check_output(): 11c4, or *note
     run(): d81. (with ‘check=True’) returns a non-zero exit status.

      -- Attributo: returncode

          Exit status of the child process.  If the process exited due
          to a signal, this will be the negative signal number.

      -- Attributo: cmd

          Command that was used to spawn the child process.

      -- Attributo: output

          Output of the child process if it was captured by *note run():
          d81. or *note check_output(): 11c4.  Otherwise, ‘None’.

      -- Attributo: stdout

          Alias for output, for symmetry with *note stderr: 3724.

      -- Attributo: stderr

          Stderr output of the child process if it was captured by *note
          run(): d81.  Otherwise, ‘None’.

     Cambiato nella versione 3.5: 'stdout' and 'stderr' attributes added

* Menu:

* Frequently Used Arguments::
* Popen Constructor::
* Exceptions: Exceptions<13>.


File: python.info,  Node: Frequently Used Arguments,  Next: Popen Constructor,  Up: Using the subprocess Module

5.18.7.2 Frequently Used Arguments
..................................

To support a wide variety of use cases, the *note Popen: 4b8.
constructor (and the convenience functions) accept a large number of
optional arguments.  For most typical use cases, many of these arguments
can be safely left at their default values.  The arguments that are most
commonly needed are:

     'args' is required for all calls and should be a string, or a
     sequence of program arguments.  Providing a sequence of arguments
     is generally preferred, as it allows the module to take care of any
     required escaping and quoting of arguments (e.g.  to permit spaces
     in file names).  If passing a single string, either 'shell' must be
     *note True: e09. (see below) or else the string must simply name
     the program to be executed without specifying any arguments.

     'stdin', 'stdout' and 'stderr' specify the executed program’s
     standard input, standard output and standard error file handles,
     respectively.  Valid values are ‘None’, *note PIPE: d82, *note
     DEVNULL: 1356, an existing file descriptor (a positive integer),
     and an existing *note file object: 13cb. with a valid file
     descriptor.  With the default settings of ‘None’, no redirection
     will occur.  *note PIPE: d82. indicates that a new pipe to the
     child should be created.  *note DEVNULL: 1356. indicates that the
     special file *note os.devnull: 1dfc. will be used.  Additionally,
     'stderr' can be *note STDOUT: 3713, which indicates that the stderr
     data from the child process should be captured into the same file
     handle as for 'stdout'.

     If 'encoding' or 'errors' are specified, or 'text' (also known as
     'universal_newlines') is true, the file objects 'stdin', 'stdout'
     and 'stderr' will be opened in text mode using the 'encoding' and
     'errors' specified in the call or the defaults for *note
     io.TextIOWrapper: 9c0.

     For 'stdin', line ending characters ‘'\n'’ in the input will be
     converted to the default line separator *note os.linesep: 25b8.
     For 'stdout' and 'stderr', all line endings in the output will be
     converted to ‘'\n'’.  For more information see the documentation of
     the *note io.TextIOWrapper: 9c0. class when the 'newline' argument
     to its constructor is ‘None’.

     If text mode is not used, 'stdin', 'stdout' and 'stderr' will be
     opened as binary streams.  No encoding or line ending conversion is
     performed.

     Cambiato nella versione 3.6: Added the 'encoding' and 'errors'
     parameters.

     Cambiato nella versione 3.7: Added the 'text' parameter as an alias
     for 'universal_newlines'.

          Nota: The newlines attribute of the file objects *note
          Popen.stdin: 3726, *note Popen.stdout: 3727. and *note
          Popen.stderr: 3728. are not updated by the *note
          Popen.communicate(): 1792. method.

     If 'shell' is ‘True’, the specified command will be executed
     through the shell.  This can be useful if you are using Python
     primarily for the enhanced control flow it offers over most system
     shells and still want convenient access to other shell features
     such as shell pipes, filename wildcards, environment variable
     expansion, and expansion of ‘~’ to a user’s home directory.
     However, note that Python itself offers implementations of many
     shell-like features (in particular, *note glob: 68, *note fnmatch:
     60, *note os.walk(): 6d1, *note os.path.expandvars(): 15e0, *note
     os.path.expanduser(): c0b, and *note shutil: ca.).

     Cambiato nella versione 3.3: When 'universal_newlines' is ‘True’,
     the class uses the encoding *note
     locale.getpreferredencoding(False): 75d. instead of
     ‘locale.getpreferredencoding()’.  See the *note io.TextIOWrapper:
     9c0. class for more information on this change.

          Nota: Read the *note Security Considerations: 3729. section
          before using ‘shell=True’.

These options, along with all of the other options, are described in
more detail in the *note Popen: 4b8. constructor documentation.


File: python.info,  Node: Popen Constructor,  Next: Exceptions<13>,  Prev: Frequently Used Arguments,  Up: Using the subprocess Module

5.18.7.3 Popen Constructor
..........................

The underlying process creation and management in this module is handled
by the *note Popen: 4b8. class.  It offers a lot of flexibility so that
developers are able to handle the less common cases not covered by the
convenience functions.

 -- Classe: subprocess.Popen (args, bufsize=-1, executable=None,
          stdin=None, stdout=None, stderr=None, preexec_fn=None,
          close_fds=True, shell=False, cwd=None, env=None,
          universal_newlines=None, startupinfo=None, creationflags=0,
          restore_signals=True, start_new_session=False, pass_fds=(), *,
          group=None, extra_groups=None, user=None, umask=-1,
          encoding=None, errors=None, text=None, pipesize=-1,
          process_group=None)

     Execute a child program in a new process.  On POSIX, the class uses
     *note os.execvpe(): 309f.-like behavior to execute the child
     program.  On Windows, the class uses the Windows ‘CreateProcess()’
     function.  The arguments to *note Popen: 4b8. are as follows.

     'args' should be a sequence of program arguments or else a single
     string or *note path-like object: 5a1.  By default, the program to
     execute is the first item in 'args' if 'args' is a sequence.  If
     'args' is a string, the interpretation is platform-dependent and
     described below.  See the 'shell' and 'executable' arguments for
     additional differences from the default behavior.  Unless otherwise
     stated, it is recommended to pass 'args' as a sequence.

          Avvertimento: For maximum reliability, use a fully qualified
          path for the executable.  To search for an unqualified name on
          ‘PATH’, use *note shutil.which(): 6dc.  On all platforms,
          passing *note sys.executable: 3ed. is the recommended way to
          launch the current Python interpreter again, and use the ‘-m’
          command-line format to launch an installed module.

          Resolving the path of 'executable' (or the first item of
          'args') is platform dependent.  For POSIX, see *note
          os.execvpe(): 309f, and note that when resolving or searching
          for the executable path, 'cwd' overrides the current working
          directory and 'env' can override the ‘PATH’ environment
          variable.  For Windows, see the documentation of the
          ‘lpApplicationName’ and ‘lpCommandLine’ parameters of WinAPI
          ‘CreateProcess’, and note that when resolving or searching for
          the executable path with ‘shell=False’, 'cwd' does not
          override the current working directory and 'env' cannot
          override the ‘PATH’ environment variable.  Using a full path
          avoids all of these variations.

     An example of passing some arguments to an external program as a
     sequence is:

          Popen(["/usr/bin/git", "commit", "-m", "Fixes a bug."])

     On POSIX, if 'args' is a string, the string is interpreted as the
     name or path of the program to execute.  However, this can only be
     done if not passing arguments to the program.

          Nota: It may not be obvious how to break a shell command into
          a sequence of arguments, especially in complex cases.  *note
          shlex.split(): 75f. can illustrate how to determine the
          correct tokenization for 'args':

               >>> import shlex, subprocess
               >>> command_line = input()
               /bin/vikings -input eggs.txt -output "spam spam.txt" -cmd "echo '$MONEY'"
               >>> args = shlex.split(command_line)
               >>> print(args)
               ['/bin/vikings', '-input', 'eggs.txt', '-output', 'spam spam.txt', '-cmd', "echo '$MONEY'"]
               >>> p = subprocess.Popen(args) # Success!

          Note in particular that options (such as '-input') and
          arguments (such as 'eggs.txt') that are separated by
          whitespace in the shell go in separate list elements, while
          arguments that need quoting or backslash escaping when used in
          the shell (such as filenames containing spaces or the 'echo'
          command shown above) are single list elements.

     On Windows, if 'args' is a sequence, it will be converted to a
     string in a manner described in *note Converting an argument
     sequence to a string on Windows: 372b.  This is because the
     underlying ‘CreateProcess()’ operates on strings.

     Cambiato nella versione 3.6: 'args' parameter accepts a *note
     path-like object: 5a1. if 'shell' is ‘False’ and a sequence
     containing path-like objects on POSIX.

     Cambiato nella versione 3.8: 'args' parameter accepts a *note
     path-like object: 5a1. if 'shell' is ‘False’ and a sequence
     containing bytes and path-like objects on Windows.

     The 'shell' argument (which defaults to ‘False’) specifies whether
     to use the shell as the program to execute.  If 'shell' is ‘True’,
     it is recommended to pass 'args' as a string rather than as a
     sequence.

     On POSIX with ‘shell=True’, the shell defaults to ‘/bin/sh’.  If
     'args' is a string, the string specifies the command to execute
     through the shell.  This means that the string must be formatted
     exactly as it would be when typed at the shell prompt.  This
     includes, for example, quoting or backslash escaping filenames with
     spaces in them.  If 'args' is a sequence, the first item specifies
     the command string, and any additional items will be treated as
     additional arguments to the shell itself.  That is to say, *note
     Popen: 4b8. does the equivalent of:

          Popen(['/bin/sh', '-c', args[0], args[1], ...])

     On Windows with ‘shell=True’, the ‘COMSPEC’ environment variable
     specifies the default shell.  The only time you need to specify
     ‘shell=True’ on Windows is when the command you wish to execute is
     built into the shell (e.g.  ‘dir’ or ‘copy’).  You do not need
     ‘shell=True’ to run a batch file or console-based executable.

          Nota: Read the *note Security Considerations: 3729. section
          before using ‘shell=True’.

     'bufsize' will be supplied as the corresponding argument to the
     *note open(): 316. function when creating the stdin/stdout/stderr
     pipe file objects:

        - ‘0’ means unbuffered (read and write are one system call and
          can return short)

        - ‘1’ means line buffered (only usable if ‘text=True’ or
          ‘universal_newlines=True’)

        - any other positive value means use a buffer of approximately
          that size

        - negative bufsize (the default) means the system default of
          io.DEFAULT_BUFFER_SIZE will be used.

     Cambiato nella versione 3.3.1: 'bufsize' now defaults to -1 to
     enable buffering by default to match the behavior that most code
     expects.  In versions prior to Python 3.2.4 and 3.3.1 it
     incorrectly defaulted to ‘0’ which was unbuffered and allowed short
     reads.  This was unintentional and did not match the behavior of
     Python 2 as most code expected.

     The 'executable' argument specifies a replacement program to
     execute.  It is very seldom needed.  When ‘shell=False’,
     'executable' replaces the program to execute specified by 'args'.
     However, the original 'args' is still passed to the program.  Most
     programs treat the program specified by 'args' as the command name,
     which can then be different from the program actually executed.  On
     POSIX, the 'args' name becomes the display name for the executable
     in utilities such as ‘ps’.  If ‘shell=True’, on POSIX the
     'executable' argument specifies a replacement shell for the default
     ‘/bin/sh’.

     Cambiato nella versione 3.6: 'executable' parameter accepts a *note
     path-like object: 5a1. on POSIX.

     Cambiato nella versione 3.8: 'executable' parameter accepts a bytes
     and *note path-like object: 5a1. on Windows.

     Cambiato nella versione 3.12: Changed Windows shell search order
     for ‘shell=True’.  The current directory and ‘%PATH%’ are replaced
     with ‘%COMSPEC%’ and ‘%SystemRoot%\System32\cmd.exe’.  As a result,
     dropping a malicious program named ‘cmd.exe’ into a current
     directory no longer works.

     'stdin', 'stdout' and 'stderr' specify the executed program’s
     standard input, standard output and standard error file handles,
     respectively.  Valid values are ‘None’, *note PIPE: d82, *note
     DEVNULL: 1356, an existing file descriptor (a positive integer),
     and an existing *note file object: 13cb. with a valid file
     descriptor.  With the default settings of ‘None’, no redirection
     will occur.  *note PIPE: d82. indicates that a new pipe to the
     child should be created.  *note DEVNULL: 1356. indicates that the
     special file *note os.devnull: 1dfc. will be used.  Additionally,
     'stderr' can be *note STDOUT: 3713, which indicates that the stderr
     data from the applications should be captured into the same file
     handle as for 'stdout'.

     If 'preexec_fn' is set to a callable object, this object will be
     called in the child process just before the child is executed.
     (POSIX only)

          Avvertimento: The 'preexec_fn' parameter is NOT SAFE to use in
          the presence of threads in your application.  The child
          process could deadlock before exec is called.

          Nota: If you need to modify the environment for the child use
          the 'env' parameter rather than doing it in a 'preexec_fn'.
          The 'start_new_session' and 'process_group' parameters should
          take the place of code using 'preexec_fn' to call *note
          os.setsid(): 1da2. or *note os.setpgid(): 3004. in the child.

     Cambiato nella versione 3.8: The 'preexec_fn' parameter is no
     longer supported in subinterpreters.  The use of the parameter in a
     subinterpreter raises *note RuntimeError: 244.  The new restriction
     may affect applications that are deployed in mod_wsgi, uWSGI, and
     other embedded environments.

     If 'close_fds' is true, all file descriptors except ‘0’, ‘1’ and
     ‘2’ will be closed before the child process is executed.  Otherwise
     when 'close_fds' is false, file descriptors obey their inheritable
     flag as described in *note Inheritance of File Descriptors: 10fe.

     On Windows, if 'close_fds' is true then no handles will be
     inherited by the child process unless explicitly passed in the
     ‘handle_list’ element of *note STARTUPINFO.lpAttributeList: e0a, or
     by standard handle redirection.

     Cambiato nella versione 3.2: The default for 'close_fds' was
     changed from *note False: d2d. to what is described above.

     Cambiato nella versione 3.7: On Windows the default for 'close_fds'
     was changed from *note False: d2d. to *note True: e09. when
     redirecting the standard handles.  It’s now possible to set
     'close_fds' to *note True: e09. when redirecting the standard
     handles.

     'pass_fds' is an optional sequence of file descriptors to keep open
     between the parent and child.  Providing any 'pass_fds' forces
     'close_fds' to be *note True: e09.  (POSIX only)

     Cambiato nella versione 3.2: The 'pass_fds' parameter was added.

     If 'cwd' is not ‘None’, the function changes the working directory
     to 'cwd' before executing the child.  'cwd' can be a string, bytes
     or *note path-like: 5a1. object.  On POSIX, the function looks for
     'executable' (or for the first item in 'args') relative to 'cwd' if
     the executable path is a relative path.

     Cambiato nella versione 3.6: 'cwd' parameter accepts a *note
     path-like object: 5a1. on POSIX.

     Cambiato nella versione 3.7: 'cwd' parameter accepts a *note
     path-like object: 5a1. on Windows.

     Cambiato nella versione 3.8: 'cwd' parameter accepts a bytes object
     on Windows.

     If 'restore_signals' is true (the default) all signals that Python
     has set to SIG_IGN are restored to SIG_DFL in the child process
     before the exec.  Currently this includes the SIGPIPE, SIGXFZ and
     SIGXFSZ signals.  (POSIX only)

     Cambiato nella versione 3.2: 'restore_signals' was added.

     If 'start_new_session' is true the ‘setsid()’ system call will be
     made in the child process prior to the execution of the subprocess.

     *note Availability: 2128.: POSIX

     Cambiato nella versione 3.2: 'start_new_session' was added.

     If 'process_group' is a non-negative integer, the ‘setpgid(0,
     value)’ system call will be made in the child process prior to the
     execution of the subprocess.

     *note Availability: 2128.: POSIX

     Cambiato nella versione 3.11: 'process_group' was added.

     If 'group' is not ‘None’, the setregid() system call will be made
     in the child process prior to the execution of the subprocess.  If
     the provided value is a string, it will be looked up via *note
     grp.getgrnam(): 372c. and the value in ‘gr_gid’ will be used.  If
     the value is an integer, it will be passed verbatim.  (POSIX only)

     *note Availability: 2128.: POSIX

     Added in version 3.9.

     If 'extra_groups' is not ‘None’, the setgroups() system call will
     be made in the child process prior to the execution of the
     subprocess.  Strings provided in 'extra_groups' will be looked up
     via *note grp.getgrnam(): 372c. and the values in ‘gr_gid’ will be
     used.  Integer values will be passed verbatim.  (POSIX only)

     *note Availability: 2128.: POSIX

     Added in version 3.9.

     If 'user' is not ‘None’, the setreuid() system call will be made in
     the child process prior to the execution of the subprocess.  If the
     provided value is a string, it will be looked up via *note
     pwd.getpwnam(): 372d. and the value in ‘pw_uid’ will be used.  If
     the value is an integer, it will be passed verbatim.  (POSIX only)

     *note Availability: 2128.: POSIX

     Added in version 3.9.

     If 'umask' is not negative, the umask() system call will be made in
     the child process prior to the execution of the subprocess.

     *note Availability: 2128.: POSIX

     Added in version 3.9.

     If 'env' is not ‘None’, it must be a mapping that defines the
     environment variables for the new process; these are used instead
     of the default behavior of inheriting the current process”
     environment.  This mapping can be str to str on any platform or
     bytes to bytes on POSIX platforms much like *note os.environ: 259.
     or *note os.environb: 25a.

          Nota: If specified, 'env' must provide any variables required
          for the program to execute.  On Windows, in order to run a
          side-by-side assembly(1) the specified 'env' 'must' include a
          valid ‘%SystemRoot%’.

     If 'encoding' or 'errors' are specified, or 'text' is true, the
     file objects 'stdin', 'stdout' and 'stderr' are opened in text mode
     with the specified 'encoding' and 'errors', as described above in
     *note Frequently Used Arguments: 3712.  The 'universal_newlines'
     argument is equivalent to 'text' and is provided for backwards
     compatibility.  By default, file objects are opened in binary mode.

     Added in version 3.6: 'encoding' and 'errors' were added.

     Added in version 3.7: 'text' was added as a more readable alias for
     'universal_newlines'.

     If given, 'startupinfo' will be a *note STARTUPINFO: 372e. object,
     which is passed to the underlying ‘CreateProcess’ function.

     If given, 'creationflags', can be one or more of the following
     flags:

        * *note CREATE_NEW_CONSOLE: 372f.

        * *note CREATE_NEW_PROCESS_GROUP: 3730.

        * *note ABOVE_NORMAL_PRIORITY_CLASS: 3731.

        * *note BELOW_NORMAL_PRIORITY_CLASS: 3732.

        * *note HIGH_PRIORITY_CLASS: 3733.

        * *note IDLE_PRIORITY_CLASS: 3734.

        * *note NORMAL_PRIORITY_CLASS: 3735.

        * *note REALTIME_PRIORITY_CLASS: 3736.

        * *note CREATE_NO_WINDOW: 3737.

        * *note DETACHED_PROCESS: 3738.

        * *note CREATE_DEFAULT_ERROR_MODE: 3739.

        * *note CREATE_BREAKAWAY_FROM_JOB: 373a.

     'pipesize' can be used to change the size of the pipe when *note
     PIPE: d82. is used for 'stdin', 'stdout' or 'stderr'.  The size of
     the pipe is only changed on platforms that support this (only Linux
     at this time of writing).  Other platforms will ignore this
     parameter.

     Cambiato nella versione 3.10: Added the 'pipesize' parameter.

     Popen objects are supported as context managers via the *note with:
     186. statement: on exit, standard file descriptors are closed, and
     the process is waited for.

          with Popen(["ifconfig"], stdout=PIPE) as proc:
              log.write(proc.stdout.read())

     Popen and the other functions in this module that use it raise an
     *note auditing event: 1c56. ‘subprocess.Popen’ with arguments
     ‘executable’, ‘args’, ‘cwd’, and ‘env’.  The value for ‘args’ may
     be a single string or a list of strings, depending on platform.

     Cambiato nella versione 3.2: Added context manager support.

     Cambiato nella versione 3.6: Popen destructor now emits a *note
     ResourceWarning: 54d. warning if the child process is still
     running.

     Cambiato nella versione 3.8: Popen can use *note os.posix_spawn():
     52f. in some cases for better performance.  On Windows Subsystem
     for Linux and QEMU User Emulation, Popen constructor using *note
     os.posix_spawn(): 52f. no longer raise an exception on errors like
     missing program, but the child process fails with a non-zero *note
     returncode: c85.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Side-by-Side_Assembly


File: python.info,  Node: Exceptions<13>,  Prev: Popen Constructor,  Up: Using the subprocess Module

5.18.7.4 Exceptions
...................

Exceptions raised in the child process, before the new program has
started to execute, will be re-raised in the parent.

The most common exception raised is *note OSError: 2c0.  This occurs,
for example, when trying to execute a non-existent file.  Applications
should prepare for *note OSError: 2c0. exceptions.  Note that, when
‘shell=True’, *note OSError: 2c0. will be raised by the child only if
the selected shell itself was not found.  To determine if the shell
failed to find the requested application, it is necessary to check the
return code or output from the subprocess.

A *note ValueError: 2ec. will be raised if *note Popen: 4b8. is called
with invalid arguments.

*note check_call(): 371f. and *note check_output(): 11c4. will raise
*note CalledProcessError: 152c. if the called process returns a non-zero
return code.

All of the functions and methods that accept a 'timeout' parameter, such
as *note run(): d81. and *note Popen.communicate(): 1792. will raise
*note TimeoutExpired: 1793. if the timeout expires before the process
exits.

Exceptions defined in this module all inherit from *note
SubprocessError: 3719.

Added in version 3.3: The *note SubprocessError: 3719. base class was
added.


File: python.info,  Node: Security Considerations,  Next: Popen Objects,  Prev: Using the subprocess Module,  Up: subprocess — Subprocess management

5.18.7.5 Security Considerations
................................

Unlike some other popen functions, this library will not implicitly
choose to call a system shell.  This means that all characters,
including shell metacharacters, can safely be passed to child processes.
If the shell is invoked explicitly, via ‘shell=True’, it is the
application’s responsibility to ensure that all whitespace and
metacharacters are quoted appropriately to avoid shell injection(1)
vulnerabilities.  On *note some platforms: 373d, it is possible to use
*note shlex.quote(): 582. for this escaping.

On Windows, batch files (‘*.bat’ or ‘*.cmd’) may be launched by the
operating system in a system shell regardless of the arguments passed to
this library.  This could result in arguments being parsed according to
shell rules, but without any escaping added by Python.  If you are
intentionally launching a batch file with arguments from untrusted
sources, consider passing ‘shell=True’ to allow Python to escape special
characters.  See gh-114539(2) for additional discussion.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Shell_injection#Shell_injection

   (2) https://github.com/python/cpython/issues/114539


File: python.info,  Node: Popen Objects,  Next: Windows Popen Helpers,  Prev: Security Considerations,  Up: subprocess — Subprocess management

5.18.7.6 Popen Objects
......................

Instances of the *note Popen: 4b8. class have the following methods:

 -- Metodo: Popen.poll ()

     Check if child process has terminated.  Set and return *note
     returncode: c85. attribute.  Otherwise, returns ‘None’.

 -- Metodo: Popen.wait (timeout=None)

     Wait for child process to terminate.  Set and return *note
     returncode: c85. attribute.

     If the process does not terminate after 'timeout' seconds, raise a
     *note TimeoutExpired: 1793. exception.  It is safe to catch this
     exception and retry the wait.

          Nota: This will deadlock when using ‘stdout=PIPE’ or
          ‘stderr=PIPE’ and the child process generates enough output to
          a pipe such that it blocks waiting for the OS pipe buffer to
          accept more data.  Use *note Popen.communicate(): 1792. when
          using pipes to avoid that.

          Nota: When the ‘timeout’ parameter is not ‘None’, then (on
          POSIX) the function is implemented using a busy loop
          (non-blocking call and short sleeps).  Use the *note asyncio:
          b. module for an asynchronous wait: see *note
          asyncio.create_subprocess_exec: c6d.

     Cambiato nella versione 3.3: 'timeout' was added.

 -- Metodo: Popen.communicate (input=None, timeout=None)

     Interact with process: Send data to stdin.  Read data from stdout
     and stderr, until end-of-file is reached.  Wait for process to
     terminate and set the *note returncode: c85. attribute.  The
     optional 'input' argument should be data to be sent to the child
     process, or ‘None’, if no data should be sent to the child.  If
     streams were opened in text mode, 'input' must be a string.
     Otherwise, it must be bytes.

     *note communicate(): 1792. returns a tuple ‘(stdout_data,
     stderr_data)’.  The data will be strings if streams were opened in
     text mode; otherwise, bytes.

     Note that if you want to send data to the process’s stdin, you need
     to create the Popen object with ‘stdin=PIPE’.  Similarly, to get
     anything other than ‘None’ in the result tuple, you need to give
     ‘stdout=PIPE’ and/or ‘stderr=PIPE’ too.

     If the process does not terminate after 'timeout' seconds, a *note
     TimeoutExpired: 1793. exception will be raised.  Catching this
     exception and retrying communication will not lose any output.
     Supplying 'input' to a subsequent post-timeout *note communicate():
     1792. call is in undefined behavior and may become an error in the
     future.

     The child process is not killed if the timeout expires, so in order
     to cleanup properly a well-behaved application should kill the
     child process and finish communication:

          proc = subprocess.Popen(...)
          try:
              outs, errs = proc.communicate(timeout=15)
          except TimeoutExpired:
              proc.kill()
              outs, errs = proc.communicate()

     After a call to *note communicate(): 1792. raises *note
     TimeoutExpired: 1793, do not call *note wait(): ee2.  Use an
     additional *note communicate(): 1792. call to finish handling pipes
     and populate the *note returncode: c85. attribute.

          Nota: The data read is buffered in memory, so do not use this
          method if the data size is large or unlimited.

     Cambiato nella versione 3.3: 'timeout' was added.

 -- Metodo: Popen.send_signal (signal)

     Sends the signal 'signal' to the child.

     Do nothing if the process completed.

          Nota: On Windows, SIGTERM is an alias for *note terminate():
          15e3.  CTRL_C_EVENT and CTRL_BREAK_EVENT can be sent to
          processes started with a 'creationflags' parameter which
          includes ‘CREATE_NEW_PROCESS_GROUP’.

 -- Metodo: Popen.terminate ()

     Stop the child.  On POSIX OSs the method sends *note SIGTERM: 15e6.
     to the child.  On Windows the Win32 API function
     ‘TerminateProcess()’ is called to stop the child.

 -- Metodo: Popen.kill ()

     Kills the child.  On POSIX OSs the function sends SIGKILL to the
     child.  On Windows *note kill(): 15e4. is an alias for *note
     terminate(): 15e3.

The following attributes are also set by the class for you to access.
Reassigning them to new values is unsupported:

 -- Attributo: Popen.args

     The 'args' argument as it was passed to *note Popen: 4b8. – a
     sequence of program arguments or else a single string.

     Added in version 3.3.

 -- Attributo: Popen.stdin

     If the 'stdin' argument was *note PIPE: d82, this attribute is a
     writeable stream object as returned by *note open(): 316.  If the
     'encoding' or 'errors' arguments were specified or the 'text' or
     'universal_newlines' argument was ‘True’, the stream is a text
     stream, otherwise it is a byte stream.  If the 'stdin' argument was
     not *note PIPE: d82, this attribute is ‘None’.

 -- Attributo: Popen.stdout

     If the 'stdout' argument was *note PIPE: d82, this attribute is a
     readable stream object as returned by *note open(): 316.  Reading
     from the stream provides output from the child process.  If the
     'encoding' or 'errors' arguments were specified or the 'text' or
     'universal_newlines' argument was ‘True’, the stream is a text
     stream, otherwise it is a byte stream.  If the 'stdout' argument
     was not *note PIPE: d82, this attribute is ‘None’.

 -- Attributo: Popen.stderr

     If the 'stderr' argument was *note PIPE: d82, this attribute is a
     readable stream object as returned by *note open(): 316.  Reading
     from the stream provides error output from the child process.  If
     the 'encoding' or 'errors' arguments were specified or the 'text'
     or 'universal_newlines' argument was ‘True’, the stream is a text
     stream, otherwise it is a byte stream.  If the 'stderr' argument
     was not *note PIPE: d82, this attribute is ‘None’.

     Avvertimento: Use *note communicate(): 1792. rather than *note
     .stdin.write: 3726, *note .stdout.read: 3727. or *note
     .stderr.read: 3728. to avoid deadlocks due to any of the other OS
     pipe buffers filling up and blocking the child process.

 -- Attributo: Popen.pid

     The process ID of the child process.

     Note that if you set the 'shell' argument to ‘True’, this is the
     process ID of the spawned shell.

 -- Attributo: Popen.returncode

     The child return code.  Initially ‘None’, *note returncode: c85. is
     set by a call to the *note poll(): 373f, *note wait(): ee2, or
     *note communicate(): 1792. methods if they detect that the process
     has terminated.

     A ‘None’ value indicates that the process hadn’t yet terminated at
     the time of the last method call.

     A negative value ‘-N’ indicates that the child was terminated by
     signal ‘N’ (POSIX only).


File: python.info,  Node: Windows Popen Helpers,  Next: Older high-level API,  Prev: Popen Objects,  Up: subprocess — Subprocess management

5.18.7.7 Windows Popen Helpers
..............................

The *note STARTUPINFO: 372e. class and following constants are only
available on Windows.

 -- Classe: subprocess.STARTUPINFO (*, dwFlags=0, hStdInput=None,
          hStdOutput=None, hStdError=None, wShowWindow=0,
          lpAttributeList=None)

     Partial support of the Windows STARTUPINFO(1) structure is used for
     *note Popen: 4b8. creation.  The following attributes can be set by
     passing them as keyword-only arguments.

     Cambiato nella versione 3.7: Keyword-only argument support was
     added.

      -- Attributo: dwFlags

          A bit field that determines whether certain *note STARTUPINFO:
          372e. attributes are used when the process creates a window.

               si = subprocess.STARTUPINFO()
               si.dwFlags = subprocess.STARTF_USESTDHANDLES | subprocess.STARTF_USESHOWWINDOW

      -- Attributo: hStdInput

          If *note dwFlags: 3743. specifies *note STARTF_USESTDHANDLES:
          3745, this attribute is the standard input handle for the
          process.  If *note STARTF_USESTDHANDLES: 3745. is not
          specified, the default for standard input is the keyboard
          buffer.

      -- Attributo: hStdOutput

          If *note dwFlags: 3743. specifies *note STARTF_USESTDHANDLES:
          3745, this attribute is the standard output handle for the
          process.  Otherwise, this attribute is ignored and the default
          for standard output is the console window’s buffer.

      -- Attributo: hStdError

          If *note dwFlags: 3743. specifies *note STARTF_USESTDHANDLES:
          3745, this attribute is the standard error handle for the
          process.  Otherwise, this attribute is ignored and the default
          for standard error is the console window’s buffer.

      -- Attributo: wShowWindow

          If *note dwFlags: 3743. specifies *note STARTF_USESHOWWINDOW:
          3749, this attribute can be any of the values that can be
          specified in the ‘nCmdShow’ parameter for the ShowWindow(2)
          function, except for ‘SW_SHOWDEFAULT’.  Otherwise, this
          attribute is ignored.

          *note SW_HIDE: 374a. is provided for this attribute.  It is
          used when *note Popen: 4b8. is called with ‘shell=True’.

      -- Attributo: lpAttributeList

          A dictionary of additional attributes for process creation as
          given in ‘STARTUPINFOEX’, see UpdateProcThreadAttribute(3).

          Supported attributes:

          'handle_list'

               Sequence of handles that will be inherited.  'close_fds'
               must be true if non-empty.

               The handles must be temporarily made inheritable by *note
               os.set_handle_inheritable(): 1102. when passed to the
               *note Popen: 4b8. constructor, else *note OSError: 2c0.
               will be raised with Windows error
               ‘ERROR_INVALID_PARAMETER’ (87).

                    Avvertimento: In a multithreaded process, use
                    caution to avoid leaking handles that are marked
                    inheritable when combining this feature with
                    concurrent calls to other process creation functions
                    that inherit all handles such as *note os.system():
                    1664.  This also applies to standard handle
                    redirection, which temporarily creates inheritable
                    handles.

          Added in version 3.7.

* Menu:

* Windows Constants::

   ---------- Footnotes ----------

   (1) https://msdn.microsoft.com/en-us/library/ms686331(v=vs.85).aspx

   (2) https://msdn.microsoft.com/en-us/library/ms633548(v=vs.85).aspx

   (3) 
https://msdn.microsoft.com/en-us/library/windows/desktop/ms686880(v=vs.85).aspx


File: python.info,  Node: Windows Constants,  Up: Windows Popen Helpers

5.18.7.8 Windows Constants
..........................

The *note subprocess: dc. module exposes the following constants.

 -- Dati: subprocess.STD_INPUT_HANDLE

     The standard input device.  Initially, this is the console input
     buffer, ‘CONIN$’.

 -- Dati: subprocess.STD_OUTPUT_HANDLE

     The standard output device.  Initially, this is the active console
     screen buffer, ‘CONOUT$’.

 -- Dati: subprocess.STD_ERROR_HANDLE

     The standard error device.  Initially, this is the active console
     screen buffer, ‘CONOUT$’.

 -- Dati: subprocess.SW_HIDE

     Hides the window.  Another window will be activated.

 -- Dati: subprocess.STARTF_USESTDHANDLES

     Specifies that the *note STARTUPINFO.hStdInput: 3744, *note
     STARTUPINFO.hStdOutput: 3746, and *note STARTUPINFO.hStdError:
     3747. attributes contain additional information.

 -- Dati: subprocess.STARTF_USESHOWWINDOW

     Specifies that the *note STARTUPINFO.wShowWindow: 3748. attribute
     contains additional information.

 -- Dati: subprocess.STARTF_FORCEONFEEDBACK

     A *note STARTUPINFO.dwFlags: 3743. parameter to specify that the
     'Working in Background' mouse cursor will be displayed while a
     process is launching.  This is the default behavior for GUI
     processes.

     Added in version 3.13.

 -- Dati: subprocess.STARTF_FORCEOFFFEEDBACK

     A *note STARTUPINFO.dwFlags: 3743. parameter to specify that the
     mouse cursor will not be changed when launching a process.

     Added in version 3.13.

 -- Dati: subprocess.CREATE_NEW_CONSOLE

     The new process has a new console, instead of inheriting its
     parent’s console (the default).

 -- Dati: subprocess.CREATE_NEW_PROCESS_GROUP

     A *note Popen: 4b8. ‘creationflags’ parameter to specify that a new
     process group will be created.  This flag is necessary for using
     *note os.kill(): 156f. on the subprocess.

     This flag is ignored if *note CREATE_NEW_CONSOLE: 372f. is
     specified.

 -- Dati: subprocess.ABOVE_NORMAL_PRIORITY_CLASS

     A *note Popen: 4b8. ‘creationflags’ parameter to specify that a new
     process will have an above average priority.

     Added in version 3.7.

 -- Dati: subprocess.BELOW_NORMAL_PRIORITY_CLASS

     A *note Popen: 4b8. ‘creationflags’ parameter to specify that a new
     process will have a below average priority.

     Added in version 3.7.

 -- Dati: subprocess.HIGH_PRIORITY_CLASS

     A *note Popen: 4b8. ‘creationflags’ parameter to specify that a new
     process will have a high priority.

     Added in version 3.7.

 -- Dati: subprocess.IDLE_PRIORITY_CLASS

     A *note Popen: 4b8. ‘creationflags’ parameter to specify that a new
     process will have an idle (lowest) priority.

     Added in version 3.7.

 -- Dati: subprocess.NORMAL_PRIORITY_CLASS

     A *note Popen: 4b8. ‘creationflags’ parameter to specify that a new
     process will have a normal priority.  (default)

     Added in version 3.7.

 -- Dati: subprocess.REALTIME_PRIORITY_CLASS

     A *note Popen: 4b8. ‘creationflags’ parameter to specify that a new
     process will have realtime priority.  You should almost never use
     REALTIME_PRIORITY_CLASS, because this interrupts system threads
     that manage mouse input, keyboard input, and background disk
     flushing.  This class can be appropriate for applications that
     «talk» directly to hardware or that perform brief tasks that should
     have limited interruptions.

     Added in version 3.7.

 -- Dati: subprocess.CREATE_NO_WINDOW

     A *note Popen: 4b8. ‘creationflags’ parameter to specify that a new
     process will not create a window.

     Added in version 3.7.

 -- Dati: subprocess.DETACHED_PROCESS

     A *note Popen: 4b8. ‘creationflags’ parameter to specify that a new
     process will not inherit its parent’s console.  This value cannot
     be used with CREATE_NEW_CONSOLE.

     Added in version 3.7.

 -- Dati: subprocess.CREATE_DEFAULT_ERROR_MODE

     A *note Popen: 4b8. ‘creationflags’ parameter to specify that a new
     process does not inherit the error mode of the calling process.
     Instead, the new process gets the default error mode.  This feature
     is particularly useful for multithreaded shell applications that
     run with hard errors disabled.

     Added in version 3.7.

 -- Dati: subprocess.CREATE_BREAKAWAY_FROM_JOB

     A *note Popen: 4b8. ‘creationflags’ parameter to specify that a new
     process is not associated with the job.

     Added in version 3.7.


File: python.info,  Node: Older high-level API,  Next: Replacing Older Functions with the subprocess Module,  Prev: Windows Popen Helpers,  Up: subprocess — Subprocess management

5.18.7.9 Older high-level API
.............................

Prior to Python 3.5, these three functions comprised the high level API
to subprocess.  You can now use *note run(): d81. in many cases, but
lots of existing code calls these functions.

 -- Funzione: subprocess.call (args, *, stdin=None, stdout=None,
          stderr=None, shell=False, cwd=None, timeout=None,
          **other_popen_kwargs)

     Run the command described by 'args'.  Wait for command to complete,
     then return the *note returncode: c85. attribute.

     Code needing to capture stdout or stderr should use *note run():
     d81. instead:

          run(...).returncode

     To suppress stdout or stderr, supply a value of *note DEVNULL:
     1356.

     The arguments shown above are merely some common ones.  The full
     function signature is the same as that of the *note Popen: 4b8.
     constructor - this function passes all supplied arguments other
     than 'timeout' directly through to that interface.

          Nota: Do not use ‘stdout=PIPE’ or ‘stderr=PIPE’ with this
          function.  The child process will block if it generates enough
          output to a pipe to fill up the OS pipe buffer as the pipes
          are not being read from.

     Cambiato nella versione 3.3: 'timeout' was added.

     Cambiato nella versione 3.12: Changed Windows shell search order
     for ‘shell=True’.  The current directory and ‘%PATH%’ are replaced
     with ‘%COMSPEC%’ and ‘%SystemRoot%\System32\cmd.exe’.  As a result,
     dropping a malicious program named ‘cmd.exe’ into a current
     directory no longer works.

 -- Funzione: subprocess.check_call (args, *, stdin=None, stdout=None,
          stderr=None, shell=False, cwd=None, timeout=None,
          **other_popen_kwargs)

     Run command with arguments.  Wait for command to complete.  If the
     return code was zero then return, otherwise raise *note
     CalledProcessError: 152c.  The *note CalledProcessError: 152c.
     object will have the return code in the *note returncode: 3720.
     attribute.  If *note check_call(): 371f. was unable to start the
     process it will propagate the exception that was raised.

     Code needing to capture stdout or stderr should use *note run():
     d81. instead:

          run(..., check=True)

     To suppress stdout or stderr, supply a value of *note DEVNULL:
     1356.

     The arguments shown above are merely some common ones.  The full
     function signature is the same as that of the *note Popen: 4b8.
     constructor - this function passes all supplied arguments other
     than 'timeout' directly through to that interface.

          Nota: Do not use ‘stdout=PIPE’ or ‘stderr=PIPE’ with this
          function.  The child process will block if it generates enough
          output to a pipe to fill up the OS pipe buffer as the pipes
          are not being read from.

     Cambiato nella versione 3.3: 'timeout' was added.

     Cambiato nella versione 3.12: Changed Windows shell search order
     for ‘shell=True’.  The current directory and ‘%PATH%’ are replaced
     with ‘%COMSPEC%’ and ‘%SystemRoot%\System32\cmd.exe’.  As a result,
     dropping a malicious program named ‘cmd.exe’ into a current
     directory no longer works.

 -- Funzione: subprocess.check_output (args, *, stdin=None, stderr=None,
          shell=False, cwd=None, encoding=None, errors=None,
          universal_newlines=None, timeout=None, text=None,
          **other_popen_kwargs)

     Run command with arguments and return its output.

     If the return code was non-zero it raises a *note
     CalledProcessError: 152c.  The *note CalledProcessError: 152c.
     object will have the return code in the *note returncode: 3720.
     attribute and any output in the *note output: 3722. attribute.

     This is equivalent to:

          run(..., check=True, stdout=PIPE).stdout

     The arguments shown above are merely some common ones.  The full
     function signature is largely the same as that of *note run(): d81.
     - most arguments are passed directly through to that interface.
     One API deviation from *note run(): d81. behavior exists: passing
     ‘input=None’ will behave the same as ‘input=b''’ (or ‘input=''’,
     depending on other arguments) rather than using the parent’s
     standard input file handle.

     By default, this function will return the data as encoded bytes.
     The actual encoding of the output data may depend on the command
     being invoked, so the decoding to text will often need to be
     handled at the application level.

     This behaviour may be overridden by setting 'text', 'encoding',
     'errors', or 'universal_newlines' to ‘True’ as described in *note
     Frequently Used Arguments: 3712. and *note run(): d81.

     To also capture standard error in the result, use
     ‘stderr=subprocess.STDOUT’:

          >>> subprocess.check_output(
          ...     "ls non_existent_file; exit 0",
          ...     stderr=subprocess.STDOUT,
          ...     shell=True)
          'ls: non_existent_file: No such file or directory\n'

     Added in version 3.1.

     Cambiato nella versione 3.3: 'timeout' was added.

     Cambiato nella versione 3.4: Support for the 'input' keyword
     argument was added.

     Cambiato nella versione 3.6: 'encoding' and 'errors' were added.
     See *note run(): d81. for details.

     Added in version 3.7: 'text' was added as a more readable alias for
     'universal_newlines'.

     Cambiato nella versione 3.12: Changed Windows shell search order
     for ‘shell=True’.  The current directory and ‘%PATH%’ are replaced
     with ‘%COMSPEC%’ and ‘%SystemRoot%\System32\cmd.exe’.  As a result,
     dropping a malicious program named ‘cmd.exe’ into a current
     directory no longer works.


File: python.info,  Node: Replacing Older Functions with the subprocess Module,  Next: Legacy Shell Invocation Functions,  Prev: Older high-level API,  Up: subprocess — Subprocess management

5.18.7.10 Replacing Older Functions with the ‘subprocess’ Module
................................................................

In this section, «a becomes b» means that b can be used as a replacement
for a.

     Nota: All «a» functions in this section fail (more or less)
     silently if the executed program cannot be found; the «b»
     replacements raise *note OSError: 2c0. instead.

     In addition, the replacements using *note check_output(): 11c4.
     will fail with a *note CalledProcessError: 152c. if the requested
     operation produces a non-zero return code.  The output is still
     available as the *note output: 3722. attribute of the raised
     exception.

In the following examples, we assume that the relevant functions have
already been imported from the *note subprocess: dc. module.

* Menu:

* Replacing /bin/sh shell command substitution::
* Replacing shell pipeline::
* Replacing os.system(): Replacing os system.
* Replacing the os.spawn family: Replacing the os spawn family.
* Replacing os.popen(): Replacing os popen.


File: python.info,  Node: Replacing /bin/sh shell command substitution,  Next: Replacing shell pipeline,  Up: Replacing Older Functions with the subprocess Module

5.18.7.11 Replacing ‘/bin/sh’ shell command substitution
........................................................

     output=$(mycmd myarg)

becomes:

     output = check_output(["mycmd", "myarg"])


File: python.info,  Node: Replacing shell pipeline,  Next: Replacing os system,  Prev: Replacing /bin/sh shell command substitution,  Up: Replacing Older Functions with the subprocess Module

5.18.7.12 Replacing shell pipeline
..................................

     output=$(dmesg | grep hda)

becomes:

     p1 = Popen(["dmesg"], stdout=PIPE)
     p2 = Popen(["grep", "hda"], stdin=p1.stdout, stdout=PIPE)
     p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
     output = p2.communicate()[0]

The ‘p1.stdout.close()’ call after starting the p2 is important in order
for p1 to receive a SIGPIPE if p2 exits before p1.

Alternatively, for trusted input, the shell’s own pipeline support may
still be used directly:

     output=$(dmesg | grep hda)

becomes:

     output = check_output("dmesg | grep hda", shell=True)


File: python.info,  Node: Replacing os system,  Next: Replacing the os spawn family,  Prev: Replacing shell pipeline,  Up: Replacing Older Functions with the subprocess Module

5.18.7.13 Replacing ‘os.system()’
.................................

     sts = os.system("mycmd" + " myarg")
     # becomes
     retcode = call("mycmd" + " myarg", shell=True)

Notes:

   * Calling the program through the shell is usually not required.

   * The *note call(): d83. return value is encoded differently to that
     of *note os.system(): 1664.

   * The *note os.system(): 1664. function ignores SIGINT and SIGQUIT
     signals while the command is running, but the caller must do this
     separately when using the *note subprocess: dc. module.

A more realistic example would look like this:

     try:
         retcode = call("mycmd" + " myarg", shell=True)
         if retcode < 0:
             print("Child was terminated by signal", -retcode, file=sys.stderr)
         else:
             print("Child returned", retcode, file=sys.stderr)
     except OSError as e:
         print("Execution failed:", e, file=sys.stderr)


File: python.info,  Node: Replacing the os spawn family,  Next: Replacing os popen,  Prev: Replacing os system,  Up: Replacing Older Functions with the subprocess Module

5.18.7.14 Replacing the ‘os.spawn’ family
.........................................

P_NOWAIT example:

     pid = os.spawnlp(os.P_NOWAIT, "/bin/mycmd", "mycmd", "myarg")
     ==>
     pid = Popen(["/bin/mycmd", "myarg"]).pid

P_WAIT example:

     retcode = os.spawnlp(os.P_WAIT, "/bin/mycmd", "mycmd", "myarg")
     ==>
     retcode = call(["/bin/mycmd", "myarg"])

Vector example:

     os.spawnvp(os.P_NOWAIT, path, args)
     ==>
     Popen([path] + args[1:])

Environment example:

     os.spawnlpe(os.P_NOWAIT, "/bin/mycmd", "mycmd", "myarg", env)
     ==>
     Popen(["/bin/mycmd", "myarg"], env={"PATH": "/usr/bin"})


File: python.info,  Node: Replacing os popen,  Prev: Replacing the os spawn family,  Up: Replacing Older Functions with the subprocess Module

5.18.7.15 Replacing ‘os.popen()’
................................

Return code handling translates as follows:

     pipe = os.popen(cmd, 'w')
     ...
     rc = pipe.close()
     if rc is not None and rc >> 8:
         print("There were some errors")
     ==>
     process = Popen(cmd, stdin=PIPE)
     ...
     process.stdin.close()
     if process.wait() != 0:
         print("There were some errors")


File: python.info,  Node: Legacy Shell Invocation Functions,  Next: Notes<2>,  Prev: Replacing Older Functions with the subprocess Module,  Up: subprocess — Subprocess management

5.18.7.16 Legacy Shell Invocation Functions
...........................................

This module also provides the following legacy functions from the 2.x
‘commands’ module.  These operations implicitly invoke the system shell
and none of the guarantees described above regarding security and
exception handling consistency are valid for these functions.

 -- Funzione: subprocess.getstatusoutput (cmd, *, encoding=None,
          errors=None)

     Return ‘(exitcode, output)’ of executing 'cmd' in a shell.

     Execute the string 'cmd' in a shell with *note check_output():
     11c4. and return a 2-tuple ‘(exitcode, output)’.  'encoding' and
     'errors' are used to decode output; see the notes on *note
     Frequently Used Arguments: 3712. for more details.

     A trailing newline is stripped from the output.  The exit code for
     the command can be interpreted as the return code of subprocess.
     Example:

          >>> subprocess.getstatusoutput('ls /bin/ls')
          (0, '/bin/ls')
          >>> subprocess.getstatusoutput('cat /bin/junk')
          (1, 'cat: /bin/junk: No such file or directory')
          >>> subprocess.getstatusoutput('/bin/junk')
          (127, 'sh: /bin/junk: not found')
          >>> subprocess.getstatusoutput('/bin/kill $$')
          (-15, '')

     *note Availability: 2128.: Unix, Windows.

     Cambiato nella versione 3.3.4: Windows support was added.

     The function now returns (exitcode, output) instead of (status,
     output) as it did in Python 3.3.3 and earlier.  exitcode has the
     same value as *note returncode: c85.

     Cambiato nella versione 3.11: Added the 'encoding' and 'errors'
     parameters.

 -- Funzione: subprocess.getoutput (cmd, *, encoding=None, errors=None)

     Return output (stdout and stderr) of executing 'cmd' in a shell.

     Like *note getstatusoutput(): 11c6, except the exit code is ignored
     and the return value is a string containing the command’s output.
     Example:

          >>> subprocess.getoutput('ls /bin/ls')
          '/bin/ls'

     *note Availability: 2128.: Unix, Windows.

     Cambiato nella versione 3.3.4: Windows support added

     Cambiato nella versione 3.11: Added the 'encoding' and 'errors'
     parameters.


File: python.info,  Node: Notes<2>,  Prev: Legacy Shell Invocation Functions,  Up: subprocess — Subprocess management

5.18.7.17 Notes
...............

* Menu:

* Timeout Behavior::
* Converting an argument sequence to a string on Windows::
* Disable use of posix_spawn(): Disable use of posix_spawn.


File: python.info,  Node: Timeout Behavior,  Next: Converting an argument sequence to a string on Windows,  Up: Notes<2>

5.18.7.18 Timeout Behavior
..........................

When using the ‘timeout’ parameter in functions like *note run(): d81,
*note Popen.wait(): ee2, or *note Popen.communicate(): 1792, users
should be aware of the following behaviors:

  1. 'Process Creation Delay': The initial process creation itself
     cannot be interrupted on many platform APIs.  This means that even
     when specifying a timeout, you are not guaranteed to see a timeout
     exception until at least after however long process creation takes.

  2. 'Extremely Small Timeout Values': Setting very small timeout values
     (such as a few milliseconds) may result in almost immediate *note
     TimeoutExpired: 1793. exceptions because process creation and
     system scheduling inherently require time.


File: python.info,  Node: Converting an argument sequence to a string on Windows,  Next: Disable use of posix_spawn,  Prev: Timeout Behavior,  Up: Notes<2>

5.18.7.19 Converting an argument sequence to a string on Windows
................................................................

On Windows, an 'args' sequence is converted to a string that can be
parsed using the following rules (which correspond to the rules used by
the MS C runtime):

  1. Arguments are delimited by white space, which is either a space or
     a tab.

  2. A string surrounded by double quotation marks is interpreted as a
     single argument, regardless of white space contained within.  A
     quoted string can be embedded in an argument.

  3. A double quotation mark preceded by a backslash is interpreted as a
     literal double quotation mark.

  4. Backslashes are interpreted literally, unless they immediately
     precede a double quotation mark.

  5. If backslashes immediately precede a double quotation mark, every
     pair of backslashes is interpreted as a literal backslash.  If the
     number of backslashes is odd, the last backslash escapes the next
     double quotation mark as described in rule 3.

Vedi anche
..........

*note shlex: c9.

     Module which provides function to parse and escape command lines.


File: python.info,  Node: Disable use of posix_spawn,  Prev: Converting an argument sequence to a string on Windows,  Up: Notes<2>

5.18.7.20 Disable use of ‘posix_spawn()’
........................................

On Linux, *note subprocess: dc. defaults to using the ‘vfork()’ system
call internally when it is safe to do so rather than ‘fork()’.  This
greatly improves performance.

     subprocess._USE_POSIX_SPAWN = False  # See CPython issue gh-NNNNNN.

It is safe to set this to false on any Python version.  It will have no
effect on older or newer versions where unsupported.  Do not assume the
attribute is available to read.  Despite the name, a true value does not
indicate the corresponding function will be used, only that it may be.

Please file issues any time you have to use these private knobs with a
way to reproduce the issue you were seeing.  Link to that issue from a
comment in your code.

Added in version 3.8: ‘_USE_POSIX_SPAWN’


File: python.info,  Node: sched — Event scheduler,  Next: queue — A synchronized queue class,  Prev: subprocess — Subprocess management,  Up: Concurrent Execution

5.18.8 ‘sched’ — Event scheduler
--------------------------------

'Source code:' Lib/sched.py(1)

__________________________________________________________________

The *note sched: c4. module defines a class which implements a general
purpose event scheduler:

 -- Classe: sched.scheduler (timefunc=time.monotonic,
          delayfunc=time.sleep)

     The *note scheduler: 132f. class defines a generic interface to
     scheduling events.  It needs two functions to actually deal with
     the «outside world» — 'timefunc' should be callable without
     arguments, and return a number (the «time», in any units
     whatsoever).  The 'delayfunc' function should be callable with one
     argument, compatible with the output of 'timefunc', and should
     delay that many time units.  'delayfunc' will also be called with
     the argument ‘0’ after each event is run to allow other threads an
     opportunity to run in multi-threaded applications.

     Cambiato nella versione 3.3: 'timefunc' and 'delayfunc' parameters
     are optional.

     Cambiato nella versione 3.3: *note scheduler: 132f. class can be
     safely used in multi-threaded environments.

Example:

     >>> import sched, time
     >>> s = sched.scheduler(time.time, time.sleep)
     >>> def print_time(a='default'):
     ...     print("From print_time", time.time(), a)
     ...
     >>> def print_some_times():
     ...     print(time.time())
     ...     s.enter(10, 1, print_time)
     ...     s.enter(5, 2, print_time, argument=('positional',))
     ...     # despite having higher priority, 'keyword' runs after 'positional' as enter() is relative
     ...     s.enter(5, 1, print_time, kwargs={'a': 'keyword'})
     ...     s.enterabs(1_650_000_000, 10, print_time, argument=("first enterabs",))
     ...     s.enterabs(1_650_000_000, 5, print_time, argument=("second enterabs",))
     ...     s.run()
     ...     print(time.time())
     ...
     >>> print_some_times()
     1652342830.3640375
     From print_time 1652342830.3642538 second enterabs
     From print_time 1652342830.3643398 first enterabs
     From print_time 1652342835.3694863 positional
     From print_time 1652342835.3696074 keyword
     From print_time 1652342840.369612 default
     1652342840.3697174

* Menu:

* Scheduler Objects::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/sched.py


File: python.info,  Node: Scheduler Objects,  Up: sched — Event scheduler

5.18.8.1 Scheduler Objects
..........................

*note scheduler: 132f. instances have the following methods and
attributes:

 -- Metodo: scheduler.enterabs (time, priority, action, argument=(),
          kwargs={})

     Schedule a new event.  The 'time' argument should be a numeric type
     compatible with the return value of the 'timefunc' function passed
     to the constructor.  Events scheduled for the same 'time' will be
     executed in the order of their 'priority'.  A lower number
     represents a higher priority.

     Executing the event means executing ‘action(*argument, **kwargs)’.
     'argument' is a sequence holding the positional arguments for
     'action'.  'kwargs' is a dictionary holding the keyword arguments
     for 'action'.

     Return value is an event which may be used for later cancellation
     of the event (see *note cancel(): 1ce3.).

     Cambiato nella versione 3.3: 'argument' parameter is optional.

     Cambiato nella versione 3.3: 'kwargs' parameter was added.

 -- Metodo: scheduler.enter (delay, priority, action, argument=(),
          kwargs={})

     Schedule an event for 'delay' more time units.  Other than the
     relative time, the other arguments, the effect and the return value
     are the same as those for *note enterabs(): 1331.

     Cambiato nella versione 3.3: 'argument' parameter is optional.

     Cambiato nella versione 3.3: 'kwargs' parameter was added.

 -- Metodo: scheduler.cancel (event)

     Remove the event from the queue.  If 'event' is not an event
     currently in the queue, this method will raise a *note ValueError:
     2ec.

 -- Metodo: scheduler.empty ()

     Return ‘True’ if the event queue is empty.

 -- Metodo: scheduler.run (blocking=True)

     Run all scheduled events.  This method will wait (using the
     'delayfunc' function passed to the constructor) for the next event,
     then execute it and so on until there are no more scheduled events.

     If 'blocking' is false executes the scheduled events due to expire
     soonest (if any) and then return the deadline of the next scheduled
     call in the scheduler (if any).

     Either 'action' or 'delayfunc' can raise an exception.  In either
     case, the scheduler will maintain a consistent state and propagate
     the exception.  If an exception is raised by 'action', the event
     will not be attempted in future calls to *note run(): 132e.

     If a sequence of events takes longer to run than the time available
     before the next event, the scheduler will simply fall behind.  No
     events will be dropped; the calling code is responsible for
     canceling events which are no longer pertinent.

     Cambiato nella versione 3.3: 'blocking' parameter was added.

 -- Attributo: scheduler.queue

     Read-only attribute returning a list of upcoming events in the
     order they will be run.  Each event is shown as a *note named
     tuple: 85f. with the following fields: time, priority, action,
     argument, kwargs.


File: python.info,  Node: queue — A synchronized queue class,  Next: contextvars — Context Variables,  Prev: sched — Event scheduler,  Up: Concurrent Execution

5.18.9 ‘queue’ — A synchronized queue class
-------------------------------------------

'Source code:' Lib/queue.py(1)

__________________________________________________________________

The *note queue: bb. module implements multi-producer, multi-consumer
queues.  It is especially useful in threaded programming when
information must be exchanged safely between multiple threads.  The
*note Queue: 159c. class in this module implements all the required
locking semantics.

The module implements three types of queue, which differ only in the
order in which the entries are retrieved.  In a FIFO queue, the first
tasks added are the first retrieved.  In a LIFO queue, the most recently
added entry is the first retrieved (operating like a stack).  With a
priority queue, the entries are kept sorted (using the *note heapq: 6d.
module) and the lowest valued entry is retrieved first.

Internally, those three types of queues use locks to temporarily block
competing threads; however, they are not designed to handle reentrancy
within a thread.

In addition, the module implements a «simple» FIFO queue type, *note
SimpleQueue: d63, whose specific implementation provides additional
guarantees in exchange for the smaller functionality.

The *note queue: bb. module defines the following classes and
exceptions:

 -- Classe: queue.Queue (maxsize=0)

     Constructor for a FIFO queue.  'maxsize' is an integer that sets
     the upperbound limit on the number of items that can be placed in
     the queue.  Insertion will block once this size has been reached,
     until queue items are consumed.  If 'maxsize' is less than or equal
     to zero, the queue size is infinite.

 -- Classe: queue.LifoQueue (maxsize=0)

     Constructor for a LIFO queue.  'maxsize' is an integer that sets
     the upperbound limit on the number of items that can be placed in
     the queue.  Insertion will block once this size has been reached,
     until queue items are consumed.  If 'maxsize' is less than or equal
     to zero, the queue size is infinite.

 -- Classe: queue.PriorityQueue (maxsize=0)

     Constructor for a priority queue.  'maxsize' is an integer that
     sets the upperbound limit on the number of items that can be placed
     in the queue.  Insertion will block once this size has been
     reached, until queue items are consumed.  If 'maxsize' is less than
     or equal to zero, the queue size is infinite.

     The lowest valued entries are retrieved first (the lowest valued
     entry is the one that would be returned by ‘min(entries)’).  A
     typical pattern for entries is a tuple in the form:
     ‘(priority_number, data)’.

     If the 'data' elements are not comparable, the data can be wrapped
     in a class that ignores the data item and only compares the
     priority number:

          from dataclasses import dataclass, field
          from typing import Any

          @dataclass(order=True)
          class PrioritizedItem:
              priority: int
              item: Any=field(compare=False)

 -- Classe: queue.SimpleQueue

     Constructor for an unbounded FIFO queue.  Simple queues lack
     advanced functionality such as task tracking.

     Added in version 3.7.

 -- Eccezione: queue.Empty

     Exception raised when non-blocking *note get(): 31a9. (or *note
     get_nowait(): 376a.) is called on a *note Queue: 159c. object which
     is empty.

 -- Eccezione: queue.Full

     Exception raised when non-blocking *note put(): 376b. (or *note
     put_nowait(): 31a8.) is called on a *note Queue: 159c. object which
     is full.

 -- Eccezione: queue.ShutDown

     Exception raised when *note put(): 376b. or *note get(): 31a9. is
     called on a *note Queue: 159c. object which has been shut down.

     Added in version 3.13.

* Menu:

* Queue Objects::
* SimpleQueue Objects::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/queue.py


File: python.info,  Node: Queue Objects,  Next: SimpleQueue Objects,  Up: queue — A synchronized queue class

5.18.9.1 Queue Objects
......................

Queue objects (*note Queue: 159c, *note LifoQueue: 2699, or *note
PriorityQueue: 269a.) provide the public methods described below.

 -- Metodo: Queue.qsize ()

     Return the approximate size of the queue.  Note, qsize() > 0
     doesn’t guarantee that a subsequent get() will not block, nor will
     qsize() < maxsize guarantee that put() will not block.

 -- Metodo: Queue.empty ()

     Return ‘True’ if the queue is empty, ‘False’ otherwise.  If empty()
     returns ‘True’ it doesn’t guarantee that a subsequent call to put()
     will not block.  Similarly, if empty() returns ‘False’ it doesn’t
     guarantee that a subsequent call to get() will not block.

 -- Metodo: Queue.full ()

     Return ‘True’ if the queue is full, ‘False’ otherwise.  If full()
     returns ‘True’ it doesn’t guarantee that a subsequent call to get()
     will not block.  Similarly, if full() returns ‘False’ it doesn’t
     guarantee that a subsequent call to put() will not block.

 -- Metodo: Queue.put (item, block=True, timeout=None)

     Put 'item' into the queue.  If optional args 'block' is true and
     'timeout' is ‘None’ (the default), block if necessary until a free
     slot is available.  If 'timeout' is a positive number, it blocks at
     most 'timeout' seconds and raises the *note Full: 3653. exception
     if no free slot was available within that time.  Otherwise ('block'
     is false), put an item on the queue if a free slot is immediately
     available, else raise the *note Full: 3653. exception ('timeout' is
     ignored in that case).

     Raises *note ShutDown: 544. if the queue has been shut down.

 -- Metodo: Queue.put_nowait (item)

     Equivalent to ‘put(item, block=False)’.

 -- Metodo: Queue.get (block=True, timeout=None)

     Remove and return an item from the queue.  If optional args 'block'
     is true and 'timeout' is ‘None’ (the default), block if necessary
     until an item is available.  If 'timeout' is a positive number, it
     blocks at most 'timeout' seconds and raises the *note Empty: 3652.
     exception if no item was available within that time.  Otherwise
     ('block' is false), return an item if one is immediately available,
     else raise the *note Empty: 3652. exception ('timeout' is ignored
     in that case).

     Prior to 3.0 on POSIX systems, and for all versions on Windows, if
     'block' is true and 'timeout' is ‘None’, this operation goes into
     an uninterruptible wait on an underlying lock.  This means that no
     exceptions can occur, and in particular a SIGINT will not trigger a
     *note KeyboardInterrupt: bc7.

     Raises *note ShutDown: 544. if the queue has been shut down and is
     empty, or if the queue has been shut down immediately.

 -- Metodo: Queue.get_nowait ()

     Equivalent to ‘get(False)’.

Two methods are offered to support tracking whether enqueued tasks have
been fully processed by daemon consumer threads.

 -- Metodo: Queue.task_done ()

     Indicate that a formerly enqueued task is complete.  Used by queue
     consumer threads.  For each *note get(): 31a9. used to fetch a
     task, a subsequent call to *note task_done(): 364e. tells the queue
     that the processing on the task is complete.

     If a *note join(): 364f. is currently blocking, it will resume when
     all items have been processed (meaning that a *note task_done():
     364e. call was received for every item that had been *note put():
     376b. into the queue).

     Raises a *note ValueError: 2ec. if called more times than there
     were items placed in the queue.

 -- Metodo: Queue.join ()

     Blocks until all items in the queue have been gotten and processed.

     The count of unfinished tasks goes up whenever an item is added to
     the queue.  The count goes down whenever a consumer thread calls
     *note task_done(): 364e. to indicate that the item was retrieved
     and all work on it is complete.  When the count of unfinished tasks
     drops to zero, *note join(): 364f. unblocks.

* Menu:

* Waiting for task completion::
* Terminating queues::


File: python.info,  Node: Waiting for task completion,  Next: Terminating queues,  Up: Queue Objects

5.18.9.2 Waiting for task completion
....................................

Example of how to wait for enqueued tasks to be completed:

     import threading
     import queue

     q = queue.Queue()

     def worker():
         while True:
             item = q.get()
             print(f'Working on {item}')
             print(f'Finished {item}')
             q.task_done()

     # Turn-on the worker thread.
     threading.Thread(target=worker, daemon=True).start()

     # Send thirty task requests to the worker.
     for item in range(30):
         q.put(item)

     # Block until all tasks are done.
     q.join()
     print('All work completed')


File: python.info,  Node: Terminating queues,  Prev: Waiting for task completion,  Up: Queue Objects

5.18.9.3 Terminating queues
...........................

When no longer needed, *note Queue: 159c. objects can be wound down
until empty or terminated immediately with a hard shutdown.

 -- Metodo: Queue.shutdown (immediate=False)

     Put a *note Queue: 159c. instance into a shutdown mode.

     The queue can no longer grow.  Future calls to *note put(): 376b.
     raise *note ShutDown: 544.  Currently blocked callers of *note
     put(): 376b. will be unblocked and will raise *note ShutDown: 544.
     in the formerly blocked thread.

     If 'immediate' is false (the default), the queue can be wound down
     normally with *note get(): 31a9. calls to extract tasks that have
     already been loaded.

     And if *note task_done(): 364e. is called for each remaining task,
     a pending *note join(): 364f. will be unblocked normally.

     Once the queue is empty, future calls to *note get(): 31a9. will
     raise *note ShutDown: 544.

     If 'immediate' is true, the queue is terminated immediately.  The
     queue is drained to be completely empty and the count of unfinished
     tasks is reduced by the number of tasks drained.  If unfinished
     tasks is zero, callers of *note join(): 364f. are unblocked.  Also,
     blocked callers of *note get(): 31a9. are unblocked and will raise
     *note ShutDown: 544. because the queue is empty.

     Use caution when using *note join(): 364f. with 'immediate' set to
     true.  This unblocks the join even when no work has been done on
     the tasks, violating the usual invariant for joining a queue.

     Added in version 3.13.


File: python.info,  Node: SimpleQueue Objects,  Prev: Queue Objects,  Up: queue — A synchronized queue class

5.18.9.4 SimpleQueue Objects
............................

*note SimpleQueue: d63. objects provide the public methods described
below.

 -- Metodo: SimpleQueue.qsize ()

     Return the approximate size of the queue.  Note, qsize() > 0
     doesn’t guarantee that a subsequent get() will not block.

 -- Metodo: SimpleQueue.empty ()

     Return ‘True’ if the queue is empty, ‘False’ otherwise.  If empty()
     returns ‘False’ it doesn’t guarantee that a subsequent call to
     get() will not block.

 -- Metodo: SimpleQueue.put (item, block=True, timeout=None)

     Put 'item' into the queue.  The method never blocks and always
     succeeds (except for potential low-level errors such as failure to
     allocate memory).  The optional args 'block' and 'timeout' are
     ignored and only provided for compatibility with *note Queue.put():
     376b.

     'Dettaglio dell’implementazione di CPython:' This method has a C
     implementation which is reentrant.  That is, a ‘put()’ or ‘get()’
     call can be interrupted by another ‘put()’ call in the same thread
     without deadlocking or corrupting internal state inside the queue.
     This makes it appropriate for use in destructors such as ‘__del__’
     methods or *note weakref: 11a. callbacks.

 -- Metodo: SimpleQueue.put_nowait (item)

     Equivalent to ‘put(item, block=False)’, provided for compatibility
     with *note Queue.put_nowait(): 31a8.

 -- Metodo: SimpleQueue.get (block=True, timeout=None)

     Remove and return an item from the queue.  If optional args 'block'
     is true and 'timeout' is ‘None’ (the default), block if necessary
     until an item is available.  If 'timeout' is a positive number, it
     blocks at most 'timeout' seconds and raises the *note Empty: 3652.
     exception if no item was available within that time.  Otherwise
     ('block' is false), return an item if one is immediately available,
     else raise the *note Empty: 3652. exception ('timeout' is ignored
     in that case).

 -- Metodo: SimpleQueue.get_nowait ()

     Equivalent to ‘get(False)’.

Vedi anche
..........

Class *note multiprocessing.Queue: 1b71.

     A queue class for use in a multi-processing (rather than
     multi-threading) context.

*note collections.deque: 7f5. is an alternative implementation of
unbounded queues with fast atomic *note append(): 2960. and *note
popleft(): 2966. operations that do not require locking and also support
indexing.


File: python.info,  Node: contextvars — Context Variables,  Next: _thread — Low-level threading API,  Prev: queue — A synchronized queue class,  Up: Concurrent Execution

5.18.10 ‘contextvars’ — Context Variables
-----------------------------------------

__________________________________________________________________

This module provides APIs to manage, store, and access context-local
state.  The *note ContextVar: 185d. class is used to declare and work
with 'Context Variables'.  The *note copy_context(): 3605. function and
the *note Context: 177. class should be used to manage the current
context in asynchronous frameworks.

Context managers that have state should use Context Variables instead of
*note threading.local(): 1847. to prevent their state from bleeding to
other code unexpectedly, when used in concurrent code.

See also PEP 567(1) for additional details.

Added in version 3.7.

* Menu:

* Context Variables::
* Manual Context Management::
* asyncio support::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0567/


File: python.info,  Node: Context Variables,  Next: Manual Context Management,  Up: contextvars — Context Variables

5.18.10.1 Context Variables
...........................

 -- Classe: contextvars.ContextVar (name[, *, default])

     This class is used to declare a new Context Variable, e.g.:

          var: ContextVar[int] = ContextVar('var', default=42)

     The required 'name' parameter is used for introspection and debug
     purposes.

     The optional keyword-only 'default' parameter is returned by *note
     ContextVar.get(): 377e. when no value for the variable is found in
     the current context.

     'Important:' Context Variables should be created at the top module
     level and never in closures.  *note Context: 177. objects hold
     strong references to context variables which prevents context
     variables from being properly garbage collected.

      -- Attributo: name

          The name of the variable.  This is a read-only property.

          Added in version 3.7.1.

      -- Metodo: get ([default])

          Return a value for the context variable for the current
          context.

          If there is no value for the variable in the current context,
          the method will:

             * return the value of the 'default' argument of the method,
               if provided; or

             * return the default value for the context variable, if it
               was created with one; or

             * raise a *note LookupError: 2633.

      -- Metodo: set (value)

          Call to set a new value for the context variable in the
          current context.

          The required 'value' argument is the new value for the context
          variable.

          Returns a *note Token: 1e2. object that can be used to restore
          the variable to its previous value via the *note
          ContextVar.reset(): 3780. method.

          For convenience, the token object can be used as a context
          manager to avoid calling *note ContextVar.reset(): 3780.
          manually:

               var = ContextVar('var', default='default value')

               with var.set('new value'):
                   assert var.get() == 'new value'

               assert var.get() == 'default value'

          It is a shorthand for:

               var = ContextVar('var', default='default value')

               token = var.set('new value')
               try:
                   assert var.get() == 'new value'
               finally:
                   var.reset(token)

               assert var.get() == 'default value'

          Added in version 3.14: Added support for using tokens as
          context managers.

      -- Metodo: reset (token)

          Reset the context variable to the value it had before the
          *note ContextVar.set(): 177a. that created the 'token' was
          used.

          For example:

               var = ContextVar('var')

               token = var.set('new value')
               # code that uses 'var'; var.get() returns 'new value'.
               var.reset(token)

               # After the reset call the var has no value again, so
               # var.get() would raise a LookupError.

          The same 'token' cannot be used twice.

 -- Classe: contextvars.Token

     'Token' objects are returned by the *note ContextVar.set(): 177a.
     method.  They can be passed to the *note ContextVar.reset(): 3780.
     method to revert the value of the variable to what it was before
     the corresponding 'set'.  A single token cannot reset a context
     variable more than once.

     Tokens support the *note context manager protocol: 23ee. to
     automatically reset context variables.  See *note ContextVar.set():
     177a.

     Added in version 3.14: Added support for usage as a context
     manager.

      -- Attributo: var

          A read-only property.  Points to the *note ContextVar: 185d.
          object that created the token.

      -- Attributo: old_value

          A read-only property.  Set to the value the variable had
          before the *note ContextVar.set(): 177a. method call that
          created the token.  It points to *note Token.MISSING: 17e1. if
          the variable was not set before the call.

      -- Attributo: MISSING

          A marker object used by *note Token.old_value: 3782.


File: python.info,  Node: Manual Context Management,  Next: asyncio support,  Prev: Context Variables,  Up: contextvars — Context Variables

5.18.10.2 Manual Context Management
...................................

 -- Funzione: contextvars.copy_context ()

     Returns a copy of the current *note Context: 177. object.

     The following snippet gets a copy of the current context and prints
     all variables and their values that are set in it:

          ctx: Context = copy_context()
          print(list(ctx.items()))

     The function has an 'O'(1) complexity, i.e.  works equally fast for
     contexts with a few context variables and for contexts that have a
     lot of them.

 -- Classe: contextvars.Context

     A mapping of *note ContextVars: 185d. to their values.

     ‘Context()’ creates an empty context with no values in it.  To get
     a copy of the current context use the *note copy_context(): 3605.
     function.

     Each thread has its own effective stack of ‘Context’ objects.  The
     *note current context: 194c. is the ‘Context’ object at the top of
     the current thread’s stack.  All ‘Context’ objects in the stacks
     are considered to be 'entered'.

     'Entering' a context, which can be done by calling its *note run():
     1933. method, makes the context the current context by pushing it
     onto the top of the current thread’s context stack.

     'Exiting' from the current context, which can be done by returning
     from the callback passed to the *note run(): 1933. method, restores
     the current context to what it was before the context was entered
     by popping the context off the top of the context stack.

     Since each thread has its own context stack, *note ContextVar:
     185d. objects behave in a similar fashion to *note
     threading.local(): 1847. when values are assigned in different
     threads.

     Attempting to enter an already entered context, including contexts
     entered in other threads, raises a *note RuntimeError: 244.

     After exiting a context, it can later be re-entered (from any
     thread).

     Any changes to *note ContextVar: 185d. values via the *note
     ContextVar.set(): 177a. method are recorded in the current context.
     The *note ContextVar.get(): 377e. method returns the value
     associated with the current context.  Exiting a context effectively
     reverts any changes made to context variables while the context was
     entered (if needed, the values can be restored by re-entering the
     context).

     Context implements the *note collections.abc.Mapping: ac9.
     interface.

      -- Metodo: run (callable, *args, **kwargs)

          Enters the Context, executes ‘callable(*args, **kwargs)’, then
          exits the Context.  Returns 'callable'’s return value, or
          propagates an exception if one occurred.

          Example:

               import contextvars

               var = contextvars.ContextVar('var')
               var.set('spam')
               print(var.get())  # 'spam'

               ctx = contextvars.copy_context()

               def main():
                   # 'var' was set to 'spam' before
                   # calling 'copy_context()' and 'ctx.run(main)', so:
                   print(var.get())  # 'spam'
                   print(ctx[var])  # 'spam'

                   var.set('ham')

                   # Now, after setting 'var' to 'ham':
                   print(var.get())  # 'ham'
                   print(ctx[var])  # 'ham'

               # Any changes that the 'main' function makes to 'var'
               # will be contained in 'ctx'.
               ctx.run(main)

               # The 'main()' function was run in the 'ctx' context,
               # so changes to 'var' are contained in it:
               print(ctx[var])  # 'ham'

               # However, outside of 'ctx', 'var' is still set to 'spam':
               print(var.get())  # 'spam'

      -- Metodo: copy ()

          Return a shallow copy of the context object.

      -- Describe: var in context

          Return ‘True’ if the 'context' has a value for 'var' set;
          return ‘False’ otherwise.

      -- Describe: context[var]

          Return the value of the 'var' *note ContextVar: 185d.
          variable.  If the variable is not set in the context object, a
          *note KeyError: 5e7. is raised.

      -- Metodo: get (var[, default])

          Return the value for 'var' if 'var' has the value in the
          context object.  Return 'default' otherwise.  If 'default' is
          not given, return ‘None’.

      -- Describe: iter(context)

          Return an iterator over the variables stored in the context
          object.

      -- Describe: len(proxy)

          Return the number of variables set in the context object.

      -- Metodo: keys ()

          Return a list of all variables in the context object.

      -- Metodo: values ()

          Return a list of all variables” values in the context object.

      -- Metodo: items ()

          Return a list of 2-tuples containing all variables and their
          values in the context object.


File: python.info,  Node: asyncio support,  Prev: Manual Context Management,  Up: contextvars — Context Variables

5.18.10.3 asyncio support
.........................

Context variables are natively supported in *note asyncio: b. and are
ready to be used without any extra configuration.  For example, here is
a simple echo server, that uses a context variable to make the address
of a remote client available in the Task that handles that client:

     import asyncio
     import contextvars

     client_addr_var = contextvars.ContextVar('client_addr')

     def render_goodbye():
         # The address of the currently handled client can be accessed
         # without passing it explicitly to this function.

         client_addr = client_addr_var.get()
         return f'Good bye, client @ {client_addr}\r\n'.encode()

     async def handle_request(reader, writer):
         addr = writer.transport.get_extra_info('socket').getpeername()
         client_addr_var.set(addr)

         # In any code that we call is now possible to get
         # client's address by calling 'client_addr_var.get()'.

         while True:
             line = await reader.readline()
             print(line)
             if not line.strip():
                 break

         writer.write(b'HTTP/1.1 200 OK\r\n')  # status line
         writer.write(b'\r\n')  # headers
         writer.write(render_goodbye())  # body
         writer.close()

     async def main():
         srv = await asyncio.start_server(
             handle_request, '127.0.0.1', 8081)

         async with srv:
             await srv.serve_forever()

     asyncio.run(main())

     # To test it you can use telnet or curl:
     #     telnet 127.0.0.1 8081
     #     curl 127.0.0.1:8081

The following are support modules for some of the above services:


File: python.info,  Node: _thread — Low-level threading API,  Prev: contextvars — Context Variables,  Up: Concurrent Execution

5.18.11 ‘_thread’ — Low-level threading API
-------------------------------------------

__________________________________________________________________

This module provides low-level primitives for working with multiple
threads (also called 'light-weight processes' or 'tasks') — multiple
threads of control sharing their global data space.  For
synchronization, simple locks (also called 'mutexes' or 'binary
semaphores') are provided.  The *note threading: f3. module provides an
easier to use and higher-level threading API built on top of this
module.

Cambiato nella versione 3.7: This module used to be optional, it is now
always available.

This module defines the following constants and functions:

 -- Eccezione: _thread.error

     Raised on thread-specific errors.

     Cambiato nella versione 3.3: This is now a synonym of the built-in
     *note RuntimeError: 244.

 -- Dati: _thread.LockType

     This is the type of lock objects.

 -- Funzione: _thread.start_new_thread (function, args[, kwargs])

     Start a new thread and return its identifier.  The thread executes
     the function 'function' with the argument list 'args' (which must
     be a tuple).  The optional 'kwargs' argument specifies a dictionary
     of keyword arguments.

     When the function returns, the thread silently exits.

     When the function terminates with an unhandled exception, *note
     sys.unraisablehook(): 508. is called to handle the exception.  The
     'object' attribute of the hook argument is 'function'.  By default,
     a stack trace is printed and then the thread exits (but other
     threads continue to run).

     When the function raises a *note SystemExit: f3e. exception, it is
     silently ignored.

     Raises an *note auditing event: 1c56. ‘_thread.start_new_thread’
     with arguments ‘function’, ‘args’, ‘kwargs’.

     Cambiato nella versione 3.8: *note sys.unraisablehook(): 508. is
     now used to handle unhandled exceptions.

 -- Funzione: _thread.interrupt_main (signum=signal.SIGINT, /)

     Simulate the effect of a signal arriving in the main thread.  A
     thread can use this function to interrupt the main thread, though
     there is no guarantee that the interruption will happen
     immediately.

     If given, 'signum' is the number of the signal to simulate.  If
     'signum' is not given, *note signal.SIGINT: 253. is simulated.

     If the given signal isn’t handled by Python (it was set to *note
     signal.SIG_DFL: 1b9a. or *note signal.SIG_IGN: 1b99.), this
     function does nothing.

     Cambiato nella versione 3.10: The 'signum' argument is added to
     customize the signal number.

          Nota: This does not emit the corresponding signal but
          schedules a call to the associated handler (if it exists).  If
          you want to truly emit the signal, use *note
          signal.raise_signal(): 1b77.

 -- Funzione: _thread.exit ()

     Raise the *note SystemExit: f3e. exception.  When not caught, this
     will cause the thread to exit silently.

 -- Funzione: _thread.allocate_lock ()

     Return a new lock object.  Methods of locks are described below.
     The lock is initially unlocked.

 -- Funzione: _thread.get_ident ()

     Return the “thread identifier” of the current thread.  This is a
     nonzero integer.  Its value has no direct meaning; it is intended
     as a magic cookie to be used e.g.  to index a dictionary of
     thread-specific data.  Thread identifiers may be recycled when a
     thread exits and another thread is created.

 -- Funzione: _thread.get_native_id ()

     Return the native integral Thread ID of the current thread assigned
     by the kernel.  This is a non-negative integer.  Its value may be
     used to uniquely identify this particular thread system-wide (until
     the thread terminates, after which the value may be recycled by the
     OS).

     *note Availability: 2128.: Windows, FreeBSD, Linux, macOS, OpenBSD,
     NetBSD, AIX, DragonFlyBSD, GNU/kFreeBSD.

     Added in version 3.8.

     Cambiato nella versione 3.13: Added support for GNU/kFreeBSD.

 -- Funzione: _thread.stack_size ([size])

     Return the thread stack size used when creating new threads.  The
     optional 'size' argument specifies the stack size to be used for
     subsequently created threads, and must be 0 (use platform or
     configured default) or a positive integer value of at least 32,768
     (32 KiB). If 'size' is not specified, 0 is used.  If changing the
     thread stack size is unsupported, a *note RuntimeError: 244. is
     raised.  If the specified stack size is invalid, a *note
     ValueError: 2ec. is raised and the stack size is unmodified.  32
     KiB is currently the minimum supported stack size value to
     guarantee sufficient stack space for the interpreter itself.  Note
     that some platforms may have particular restrictions on values for
     the stack size, such as requiring a minimum stack size > 32 KiB or
     requiring allocation in multiples of the system memory page size -
     platform documentation should be referred to for more information
     (4 KiB pages are common; using multiples of 4096 for the stack size
     is the suggested approach in the absence of more specific
     information).

     *note Availability: 2128.: Windows, pthreads.

     Unix platforms with POSIX threads support.

 -- Dati: _thread.TIMEOUT_MAX

     The maximum value allowed for the 'timeout' parameter of *note
     Lock.acquire: 8a8.  Specifying a timeout greater than this value
     will raise an *note OverflowError: a83.

     Added in version 3.2.

Lock objects have the following methods:

 -- Metodo: lock.acquire (blocking=True, timeout=-1)

     Without any optional argument, this method acquires the lock
     unconditionally, if necessary waiting until it is released by
     another thread (only one thread at a time can acquire a lock —
     that’s their reason for existence).

     If the 'blocking' argument is present, the action depends on its
     value: if it is false, the lock is only acquired if it can be
     acquired immediately without waiting, while if it is true, the lock
     is acquired unconditionally as above.

     If the floating-point 'timeout' argument is present and positive,
     it specifies the maximum wait time in seconds before returning.  A
     negative 'timeout' argument specifies an unbounded wait.  You
     cannot specify a 'timeout' if 'blocking' is false.

     The return value is ‘True’ if the lock is acquired successfully,
     ‘False’ if not.

     Cambiato nella versione 3.2: The 'timeout' parameter is new.

     Cambiato nella versione 3.2: Lock acquires can now be interrupted
     by signals on POSIX.

     Cambiato nella versione 3.14: Lock acquires can now be interrupted
     by signals on Windows.

 -- Metodo: lock.release ()

     Releases the lock.  The lock must have been acquired earlier, but
     not necessarily by the same thread.

 -- Metodo: lock.locked ()

     Return the status of the lock: ‘True’ if it has been acquired by
     some thread, ‘False’ if not.

In addition to these methods, lock objects can also be used via the
*note with: 186. statement, e.g.:

     import _thread

     a_lock = _thread.allocate_lock()

     with a_lock:
         print("a_lock is locked while this executes")

'Caveats:'

   * Interrupts always go to the main thread (the *note
     KeyboardInterrupt: bc7. exception will be received by that thread.)

   * Calling *note sys.exit(): 277. or raising the *note SystemExit:
     f3e. exception is equivalent to calling *note _thread.exit(): 378f.

   * When the main thread exits, it is system defined whether the other
     threads survive.  On most systems, they are killed without
     executing *note try: 8f9. … *note finally: 1b0. clauses or
     executing object destructors.


File: python.info,  Node: Networking and Interprocess Communication,  Next: Internet Data Handling,  Prev: Concurrent Execution,  Up: The Python Standard Library

5.19 Networking and Interprocess Communication
==============================================

The modules described in this chapter provide mechanisms for networking
and inter-processes communication.

Some modules only work for two processes that are on the same machine,
e.g.  *note signal: cb. and *note mmap: 94.  Other modules support
networking protocols that two or more processes can use to communicate
across machines.

The list of modules described in this chapter is:

* Menu:

* asyncio — Asynchronous I/O::
* socket — Low-level networking interface::
* ssl — TLS/SSL wrapper for socket objects::
* select — Waiting for I/O completion::
* selectors — High-level I/O multiplexing::
* signal — Set handlers for asynchronous events::
* mmap — Memory-mapped file support::


File: python.info,  Node: asyncio — Asynchronous I/O,  Next: socket — Low-level networking interface,  Up: Networking and Interprocess Communication

5.19.1 ‘asyncio’ — Asynchronous I/O
-----------------------------------

__________________________________________________________________

Hello World!
............

     import asyncio

     async def main():
         print('Hello ...')
         await asyncio.sleep(1)
         print('... World!')

     asyncio.run(main())

asyncio is a library to write 'concurrent' code using the 'async/await'
syntax.

asyncio is used as a foundation for multiple Python asynchronous
frameworks that provide high-performance network and web-servers,
database connection libraries, distributed task queues, etc.

asyncio is often a perfect fit for IO-bound and high-level 'structured'
network code.

Vedi anche
..........

*note A Conceptual Overview of asyncio: 379d.

     Explanation of the fundamentals of asyncio.

asyncio provides a set of 'high-level' APIs to:

   * *note run Python coroutines: 379e. concurrently and have full
     control over their execution;

   * perform *note network IO and IPC: 379f.;

   * control *note subprocesses: 37a0.;

   * distribute tasks via *note queues: 37a1.;

   * *note synchronize: 37a2. concurrent code;

Additionally, there are 'low-level' APIs for 'library and framework
developers' to:

   * create and manage *note event loops: f78, which provide
     asynchronous APIs for *note networking: 37a3, running *note
     subprocesses: 37a4, handling *note OS signals: 37a5, etc;

   * implement efficient protocols using *note transports: 37a6.;

   * *note bridge: 37a7. callback-based libraries and code with
     async/await syntax.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

asyncio REPL
............

You can experiment with an ‘asyncio’ concurrent context in the *note
REPL: 492.:

     $ python -m asyncio
     asyncio REPL ...
     Use "await" directly instead of "asyncio.run()".
     Type "help", "copyright", "credits" or "license" for more information.
     >>> import asyncio
     >>> await asyncio.sleep(10, result='hello')
     'hello'

This REPL provides limited compatibility with *note PYTHON_BASIC_REPL:
1b6.  It is recommended that the default REPL is used for full
functionality and the latest features.

Raises an *note auditing event: 1c56. ‘cpython.run_stdin’ with no
arguments.

Cambiato nella versione 3.12.5: (also 3.11.10, 3.10.15, 3.9.20, and
3.8.20) Emits audit events.

Cambiato nella versione 3.13: Uses PyREPL if possible, in which case
*note PYTHONSTARTUP: 1b8. is also executed.  Emits audit events.

Reference
.........

* Menu:

* Runners::
* Coroutines and Tasks::
* Streams::
* Synchronization Primitives::
* Subprocesses::
* Queues::
* Exceptions: Exceptions<15>.
* Call Graph Introspection::
* Event Loop::
* Futures::
* Transports and Protocols::
* Policies::
* Platform Support::
* Extending::
* High-level API Index::
* Low-level API Index::
* Developing with asyncio::


File: python.info,  Node: Runners,  Next: Coroutines and Tasks,  Up: asyncio — Asynchronous I/O

5.19.1.1 Runners
................

'Source code:' Lib/asyncio/runners.py(1)

This section outlines high-level asyncio primitives to run asyncio code.

They are built on top of an *note event loop: f78. with the aim to
simplify async code usage for common wide-spread scenarios.

* Menu:

* Running an asyncio Program::
* Runner context manager::
* Handling Keyboard Interruption::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/runners.py


File: python.info,  Node: Running an asyncio Program,  Next: Runner context manager,  Up: Runners

5.19.1.2 Running an asyncio Program
...................................

 -- Funzione: asyncio.run (coro, *, debug=None, loop_factory=None)

     Execute 'coro' in an asyncio event loop and return the result.

     The argument can be any awaitable object.

     This function runs the awaitable, taking care of managing the
     asyncio event loop, 'finalizing asynchronous generators', and
     closing the executor.

     This function cannot be called when another asyncio event loop is
     running in the same thread.

     If 'debug' is ‘True’, the event loop will be run in debug mode.
     ‘False’ disables debug mode explicitly.  ‘None’ is used to respect
     the global *note Debug Mode: 2123. settings.

     If 'loop_factory' is not ‘None’, it is used to create a new event
     loop; otherwise *note asyncio.new_event_loop(): 37ac. is used.  The
     loop is closed at the end.  This function should be used as a main
     entry point for asyncio programs, and should ideally only be called
     once.  It is recommended to use 'loop_factory' to configure the
     event loop instead of policies.  Passing *note asyncio.EventLoop:
     1a4f. allows running asyncio without the policy system.

     The executor is given a timeout duration of 5 minutes to shutdown.
     If the executor hasn’t finished within that duration, a warning is
     emitted and the executor is closed.

     Example:

          async def main():
              await asyncio.sleep(1)
              print('hello')

          asyncio.run(main())

     Added in version 3.7.

     Cambiato nella versione 3.9: Updated to use *note
     loop.shutdown_default_executor(): ae6.

     Cambiato nella versione 3.10: 'debug' is ‘None’ by default to
     respect the global debug mode settings.

     Cambiato nella versione 3.12: Added 'loop_factory' parameter.

     Cambiato nella versione 3.14: 'coro' can be any awaitable object.

          Nota: The ‘asyncio’ policy system is deprecated and will be
          removed in Python 3.16; from there on, an explicit
          'loop_factory' is needed to configure the event loop.


File: python.info,  Node: Runner context manager,  Next: Handling Keyboard Interruption,  Prev: Running an asyncio Program,  Up: Runners

5.19.1.3 Runner context manager
...............................

 -- Classe: asyncio.Runner (*, debug=None, loop_factory=None)

     A context manager that simplifies 'multiple' async function calls
     in the same context.

     Sometimes several top-level async functions should be called in the
     same *note event loop: f78. and *note contextvars.Context: 177.

     If 'debug' is ‘True’, the event loop will be run in debug mode.
     ‘False’ disables debug mode explicitly.  ‘None’ is used to respect
     the global *note Debug Mode: 2123. settings.

     'loop_factory' could be used for overriding the loop creation.  It
     is the responsibility of the 'loop_factory' to set the created loop
     as the current one.  By default *note asyncio.new_event_loop():
     37ac. is used and set as current event loop with *note
     asyncio.set_event_loop(): 1b3d. if 'loop_factory' is ‘None’.

     Basically, *note asyncio.run(): 2f3. example can be rewritten with
     the runner usage:

          async def main():
              await asyncio.sleep(1)
              print('hello')

          with asyncio.Runner() as runner:
              runner.run(main())

     Added in version 3.11.

      -- Metodo: run (coro, *, context=None)

          Execute 'coro' in the embedded event loop.

          The argument can be any awaitable object.

          If the argument is a coroutine, it is wrapped in a Task.

          An optional keyword-only 'context' argument allows specifying
          a custom *note contextvars.Context: 177. for the code to run
          in.  The runner’s default context is used if context is
          ‘None’.

          Returns the awaitable’s result or raises an exception.

          This function cannot be called when another asyncio event loop
          is running in the same thread.

          Cambiato nella versione 3.14: 'coro' can be any awaitable
          object.

      -- Metodo: close ()

          Close the runner.

          Finalize asynchronous generators, shutdown default executor,
          close the event loop and release embedded *note
          contextvars.Context: 177.

      -- Metodo: get_loop ()

          Return the event loop associated with the runner instance.

          Nota: *note Runner: 2f5. uses the lazy initialization
          strategy, its constructor doesn’t initialize underlying
          low-level structures.

          Embedded 'loop' and 'context' are created at the *note with:
          186. body entering or the first call of *note run(): 2f3. or
          *note get_loop(): 37af.


File: python.info,  Node: Handling Keyboard Interruption,  Prev: Runner context manager,  Up: Runners

5.19.1.4 Handling Keyboard Interruption
.......................................

Added in version 3.11.

When *note signal.SIGINT: 253. is raised by ‘Ctrl’-‘C’, *note
KeyboardInterrupt: bc7. exception is raised in the main thread by
default.  However this doesn’t work with *note asyncio: b. because it
can interrupt asyncio internals and can hang the program from exiting.

To mitigate this issue, *note asyncio: b. handles *note signal.SIGINT:
253. as follows:

  1. *note asyncio.Runner.run(): 1935. installs a custom *note
     signal.SIGINT: 253. handler before any user code is executed and
     removes it when exiting from the function.

  2. The *note Runner: 2f5. creates the main task for the passed
     coroutine for its execution.

  3. When *note signal.SIGINT: 253. is raised by ‘Ctrl’-‘C’, the custom
     signal handler cancels the main task by calling *note
     asyncio.Task.cancel(): 4d4. which raises *note
     asyncio.CancelledError: 4d5. inside the main task.  This causes the
     Python stack to unwind, ‘try/except’ and ‘try/finally’ blocks can
     be used for resource cleanup.  After the main task is cancelled,
     *note asyncio.Runner.run(): 1935. raises *note KeyboardInterrupt:
     bc7.

  4. A user could write a tight loop which cannot be interrupted by
     *note asyncio.Task.cancel(): 4d4, in which case the second
     following ‘Ctrl’-‘C’ immediately raises the *note
     KeyboardInterrupt: bc7. without cancelling the main task.


File: python.info,  Node: Coroutines and Tasks,  Next: Streams,  Prev: Runners,  Up: asyncio — Asynchronous I/O

5.19.1.5 Coroutines and Tasks
.............................

This section outlines high-level asyncio APIs to work with coroutines
and Tasks.

* Menu:

* Coroutines: Coroutines<3>.
* Awaitables::
* Creating Tasks::
* Task Cancellation::
* Task Groups::
* Sleeping::
* Running Tasks Concurrently::
* Eager Task Factory::
* Shielding From Cancellation::
* Timeouts::
* Waiting Primitives::
* Running in Threads::
* Scheduling From Other Threads::
* Introspection::
* Task Object::


File: python.info,  Node: Coroutines<3>,  Next: Awaitables,  Up: Coroutines and Tasks

5.19.1.6 Coroutines
...................

'Source code:' Lib/asyncio/coroutines.py(1)

__________________________________________________________________

*note Coroutines: 6ba. declared with the async/await syntax is the
preferred way of writing asyncio applications.  For example, the
following snippet of code prints «hello», waits 1 second, and then
prints «world»:

     >>> import asyncio

     >>> async def main():
     ...     print('hello')
     ...     await asyncio.sleep(1)
     ...     print('world')

     >>> asyncio.run(main())
     hello
     world

Note that simply calling a coroutine will not schedule it to be
executed:

     >>> main()
     <coroutine object main at 0x1053bb7c8>

To actually run a coroutine, asyncio provides the following mechanisms:

   * The *note asyncio.run(): 2f3. function to run the top-level entry
     point «main()» function (see the above example.)

   * Awaiting on a coroutine.  The following snippet of code will print
     «hello» after waiting for 1 second, and then print «world» after
     waiting for 'another' 2 seconds:

          import asyncio
          import time

          async def say_after(delay, what):
              await asyncio.sleep(delay)
              print(what)

          async def main():
              print(f"started at {time.strftime('%X')}")

              await say_after(1, 'hello')
              await say_after(2, 'world')

              print(f"finished at {time.strftime('%X')}")

          asyncio.run(main())

     Expected output:

          started at 17:13:52
          hello
          world
          finished at 17:13:55

   * The *note asyncio.create_task(): 1c9. function to run coroutines
     concurrently as asyncio *note Tasks: 1c7.

     Let’s modify the above example and run two ‘say_after’ coroutines
     'concurrently':

          async def main():
              task1 = asyncio.create_task(
                  say_after(1, 'hello'))

              task2 = asyncio.create_task(
                  say_after(2, 'world'))

              print(f"started at {time.strftime('%X')}")

              # Wait until both tasks are completed (should take
              # around 2 seconds.)
              await task1
              await task2

              print(f"finished at {time.strftime('%X')}")

     Note that expected output now shows that the snippet runs 1 second
     faster than before:

          started at 17:14:32
          hello
          world
          finished at 17:14:34

   * The *note asyncio.TaskGroup: 4d2. class provides a more modern
     alternative to *note create_task(): 1c9.  Using this API, the last
     example becomes:

          async def main():
              async with asyncio.TaskGroup() as tg:
                  task1 = tg.create_task(
                      say_after(1, 'hello'))

                  task2 = tg.create_task(
                      say_after(2, 'world'))

                  print(f"started at {time.strftime('%X')}")

              # The await is implicit when the context manager exits.

              print(f"finished at {time.strftime('%X')}")

     The timing and output should be the same as for the previous
     version.

     Added in version 3.11: *note asyncio.TaskGroup: 4d2.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/coroutines.py


File: python.info,  Node: Awaitables,  Next: Creating Tasks,  Prev: Coroutines<3>,  Up: Coroutines and Tasks

5.19.1.7 Awaitables
...................

We say that an object is an 'awaitable' object if it can be used in an
*note await: 18d. expression.  Many asyncio APIs are designed to accept
awaitables.

There are three main types of 'awaitable' objects: 'coroutines',
'Tasks', and 'Futures'.

Coroutines
..........

Python coroutines are 'awaitables' and therefore can be awaited from
other coroutines:

     import asyncio

     async def nested():
         return 42

     async def main():
         # Nothing happens if we just call "nested()".
         # A coroutine object is created but not awaited,
         # so it *won't run at all*.
         nested()  # will raise a "RuntimeWarning".

         # Let's do it differently now and await it:
         print(await nested())  # will print "42".

     asyncio.run(main())

     Importante: In this documentation the term «coroutine» can be used
     for two closely related concepts:

        * a 'coroutine function': an *note async def: 7ee. function;

        * a 'coroutine object': an object returned by calling a
          'coroutine function'.

Tasks
.....

'Tasks' are used to schedule coroutines 'concurrently'.

When a coroutine is wrapped into a 'Task' with functions like *note
asyncio.create_task(): 1c9. the coroutine is automatically scheduled to
run soon:

     import asyncio

     async def nested():
         return 42

     async def main():
         # Schedule nested() to run soon concurrently
         # with "main()".
         task = asyncio.create_task(nested())

         # "task" can now be used to cancel "nested()", or
         # can simply be awaited to wait until it is complete:
         await task

     asyncio.run(main())

Futures
.......

A *note Future: dc8. is a special 'low-level' awaitable object that
represents an 'eventual result' of an asynchronous operation.

When a Future object is 'awaited' it means that the coroutine will wait
until the Future is resolved in some other place.

Future objects in asyncio are needed to allow callback-based code to be
used with async/await.

Normally 'there is no need' to create Future objects at the application
level code.

Future objects, sometimes exposed by libraries and some asyncio APIs,
can be awaited:

     async def main():
         await function_that_returns_a_future_object()

         # this is also valid:
         await asyncio.gather(
             function_that_returns_a_future_object(),
             some_python_coroutine()
         )

A good example of a low-level function that returns a Future object is
*note loop.run_in_executor(): ae8.


File: python.info,  Node: Creating Tasks,  Next: Task Cancellation,  Prev: Awaitables,  Up: Coroutines and Tasks

5.19.1.8 Creating Tasks
.......................

'Source code:' Lib/asyncio/tasks.py(1)

__________________________________________________________________

 -- Funzione: asyncio.create_task (coro, *, name=None, context=None,
          eager_start=None, **kwargs)

     Wrap the 'coro' *note coroutine: 379e. into a *note Task: 1c7. and
     schedule its execution.  Return the Task object.

     The full function signature is largely the same as that of the
     *note Task: 1c7. constructor (or factory) - all of the keyword
     arguments to this function are passed through to that interface.

     An optional keyword-only 'context' argument allows specifying a
     custom *note contextvars.Context: 177. for the 'coro' to run in.
     The current context copy is created when no 'context' is provided.

     An optional keyword-only 'eager_start' argument allows specifying
     if the task should execute eagerly during the call to create_task,
     or be scheduled later.  If 'eager_start' is not passed the mode set
     by *note loop.set_task_factory(): 1c8. will be used.

     The task is executed in the loop returned by *note
     get_running_loop(): d03, *note RuntimeError: 244. is raised if
     there is no running loop in current thread.

          Nota: *note asyncio.TaskGroup.create_task(): 1cb. is a new
          alternative leveraging structural concurrency; it allows for
          waiting for a group of related tasks with strong safety
          guarantees.

          Importante: Save a reference to the result of this function,
          to avoid a task disappearing mid-execution.  The event loop
          only keeps weak references to tasks.  A task that isn’t
          referenced elsewhere may get garbage collected at any time,
          even before it’s done.  For reliable «fire-and-forget»
          background tasks, gather them in a collection:

               background_tasks = set()

               for i in range(10):
                   task = asyncio.create_task(some_coro(param=i))

                   # Add task to the set. This creates a strong reference.
                   background_tasks.add(task)

                   # To prevent keeping references to finished tasks forever,
                   # make each task remove its own reference from the set after
                   # completion:
                   task.add_done_callback(background_tasks.discard)

     Added in version 3.7.

     Cambiato nella versione 3.8: Added the 'name' parameter.

     Cambiato nella versione 3.11: Added the 'context' parameter.

     Cambiato nella versione 3.14: Added the 'eager_start' parameter by
     passing on all 'kwargs'.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/asyncio/tasks.py


File: python.info,  Node: Task Cancellation,  Next: Task Groups,  Prev: Creating Tasks,  Up: Coroutines and Tasks

5.19.1.9 Task Cancellation
..........................

Tasks can easily and safely be cancelled.  When a task is cancelled,
*note asyncio.CancelledError: 4d5. will be raised in the task at the
next opportunity.

It is recommended that coroutines use ‘try/finally’ blocks to robustly
perform clean-up logic.  In case *note asyncio.CancelledError: 4d5. is
explicitly caught, it should generally be propagated when clean-up is
complete.  *note asyncio.CancelledError: 4d5. directly subclasses *note
BaseException: 7d8. so most code will not need to be aware of it.

The asyncio components that enable structured concurrency, like *note
asyncio.TaskGroup: 4d2. and *note asyncio.timeout(): 815, are
implemented using cancellation internally and might misbehave if a
coroutine swallows *note asyncio.CancelledError: 4d5.  Similarly, user
code should not generally call *note uncancel: 4d7.  However, in cases
when suppressing *note asyncio.CancelledError: 4d5. is truly desired, it
is necessary to also call ‘uncancel()’ to completely remove the
cancellation state.


File: python.info,  Node: Task Groups,  Next: Sleeping,  Prev: Task Cancellation,  Up: Coroutines and Tasks

5.19.1.10 Task Groups
.....................

Task groups combine a task creation API with a convenient and reliable
way to wait for all tasks in the group to finish.

 -- Classe: asyncio.TaskGroup

     An *note asynchronous context manager: 813. holding a group of
     tasks.  Tasks can be added to the group using *note create_task():
     1c9.  All tasks are awaited when the context manager exits.

     Added in version 3.11.

      -- Metodo: create_task (coro, *, name=None, context=None,
               eager_start=None, **kwargs)

          Create a task in this task group.  The signature matches that
          of *note asyncio.create_task(): 1c9.  If the task group is
          inactive (e.g.  not yet entered, already finished, or in the
          process of shutting down), we will close the given ‘coro’.

          Cambiato nella versione 3.13: Close the given coroutine if the
          task group is not active.

          Cambiato nella versione 3.14: Passes on all 'kwargs' to *note
          loop.create_task(): 1ca.

Example:

     async def main():
         async with asyncio.TaskGroup() as tg:
             task1 = tg.create_task(some_coro(...))
             task2 = tg.create_task(another_coro(...))
         print(f"Both tasks have completed now: {task1.result()}, {task2.result()}")

The ‘async with’ statement will wait for all tasks in the group to
finish.  While waiting, new tasks may still be added to the group (for
example, by passing ‘tg’ into one of the coroutines and calling
‘tg.create_task()’ in that coroutine).  Once the last task has finished
and the ‘async with’ block is exited, no new tasks may be added to the
group.

The first time any of the tasks belonging to the group fails with an
exception other than *note asyncio.CancelledError: 4d5, the remaining
tasks in the group are cancelled.  No further tasks can then be added to
the group.  At this point, if the body of the ‘async with’ statement is
still active (i.e., *note __aexit__(): 1989. hasn’t been called yet),
the task directly containing the ‘async with’ statement is also
cancelled.  The resulting *note asyncio.CancelledError: 4d5. will
interrupt an ‘await’, but it will not bubble out of the containing
‘async with’ statement.

Once all tasks have finished, if any tasks have failed with an exception
other than *note asyncio.CancelledError: 4d5, those exceptions are
combined in an *note ExceptionGroup: 4d3. or *note BaseExceptionGroup:
566. (as appropriate; see their documentation) which is then raised.

Two base exceptions are treated specially: If any task fails with *note
KeyboardInterrupt: bc7. or *note SystemExit: f3e, the task group still
cancels the remaining tasks and waits for them, but then the initial
*note KeyboardInterrupt: bc7. or *note SystemExit: f3e. is re-raised
instead of *note ExceptionGroup: 4d3. or *note BaseExceptionGroup: 566.

If the body of the ‘async with’ statement exits with an exception (so
*note __aexit__(): 1989. is called with an exception set), this is
treated the same as if one of the tasks failed: the remaining tasks are
cancelled and then waited for, and non-cancellation exceptions are
grouped into an exception group and raised.  The exception passed into
*note __aexit__(): 1989, unless it is *note asyncio.CancelledError: 4d5,
is also included in the exception group.  The same special case is made
for *note KeyboardInterrupt: bc7. and *note SystemExit: f3e. as in the
previous paragraph.

Task groups are careful not to mix up the internal cancellation used to
«wake up» their *note __aexit__(): 1989. with cancellation requests for
the task in which they are running made by other parties.  In
particular, when one task group is syntactically nested in another, and
both experience an exception in one of their child tasks simultaneously,
the inner task group will process its exceptions, and then the outer
task group will receive another cancellation and process its own
exceptions.

In the case where a task group is cancelled externally and also must
raise an *note ExceptionGroup: 4d3, it will call the parent task’s *note
cancel(): 4d4. method.  This ensures that a *note
asyncio.CancelledError: 4d5. will be raised at the next *note await:
18d, so the cancellation is not lost.

Task groups preserve the cancellation count reported by *note
asyncio.Task.cancelling(): 4d6.

Cambiato nella versione 3.13: Improved handling of simultaneous internal
and external cancellations and correct preservation of cancellation
counts.

* Menu:

* Terminating a Task Group::


File: python.info,  Node: Terminating a Task Group,  Up: Task Groups

5.19.1.11 Terminating a Task Group
..................................

While terminating a task group is not natively supported by the standard
library, termination can be achieved by adding an exception-raising task
to the task group and ignoring the raised exception:

     import asyncio
     from asyncio import TaskGroup

     class TerminateTaskGroup(Exception):
         """Exception raised to terminate a task group."""

     async def force_terminate_task_group():
         """Used to force termination of a task group."""
         raise TerminateTaskGroup()

     async def job(task_id, sleep_time):
         print(f'Task {task_id}: start')
         await asyncio.sleep(sleep_time)
         print(f'Task {task_id}: done')

     async def main():
         try:
             async with TaskGroup() as group:
                 # spawn some tasks
                 group.create_task(job(1, 0.5))
                 group.create_task(job(2, 1.5))
                 # sleep for 1 second
                 await asyncio.sleep(1)
                 # add an exception-raising task to force the group to terminate
                 group.create_task(force_terminate_task_group())
         except* TerminateTaskGroup:
             pass

     asyncio.run(main())

Expected output:

     Task 1: start
     Task 2: start
     Task 1: done


File: python.info,  Node: Sleeping,  Next: Running Tasks Concurrently,  Prev: Task Groups,  Up: Coroutines and Tasks

5.19.1.12 Sleeping
..................

 -- Funzione: async asyncio.sleep (delay, result=None)

     Block for 'delay' seconds.

     If 'result' is provided, it is returned to the caller when the
     coroutine completes.

     ‘sleep()’ always suspends the current task, allowing other tasks to
     run.

     Setting the delay to 0 provides an optimized path to allow other
     tasks to run.  This can be used by long-running functions to avoid
     blocking the event loop for the full duration of the function call.
     Example of coroutine displaying the current date every second for 5
     seconds:

          import asyncio
          import datetime

          async def display_date():
              loop = asyncio.get_running_loop()
              end_time = loop.time() + 5.0
              while True:
                  print(datetime.datetime.now())
                  if (loop.time() + 1.0) >= end_time:
                      break
                  await asyncio.sleep(1)

          asyncio.run(display_date())

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Cambiato nella versione 3.13: Raises *note ValueError: 2ec. if
     'delay' is *note nan: 874.


File: python.info,  Node: Running Tasks Concurrently,  Next: Eager Task Factory,  Prev: Sleeping,  Up: Coroutines and Tasks

5.19.1.13 Running Tasks Concurrently
....................................

 -- Funzione: awaitable asyncio.gather (*aws, return_exceptions=False)

     Run *note awaitable objects: 37b5. in the 'aws' sequence
     'concurrently'.

     If any awaitable in 'aws' is a coroutine, it is automatically
     scheduled as a Task.

     If all awaitables are completed successfully, the result is an
     aggregate list of returned values.  The order of result values
     corresponds to the order of awaitables in 'aws'.

     If 'return_exceptions' is ‘False’ (default), the first raised
     exception is immediately propagated to the task that awaits on
     ‘gather()’.  Other awaitables in the 'aws' sequence 'won’t be
     cancelled' and will continue to run.

     If 'return_exceptions' is ‘True’, exceptions are treated the same
     as successful results, and aggregated in the result list.

     If ‘gather()’ is 'cancelled', all submitted awaitables (that have
     not completed yet) are also 'cancelled'.

     If any Task or Future from the 'aws' sequence is 'cancelled', it is
     treated as if it raised *note CancelledError: 4d5. – the ‘gather()’
     call is 'not' cancelled in this case.  This is to prevent the
     cancellation of one submitted Task/Future to cause other
     Tasks/Futures to be cancelled.

          Nota: A new alternative to create and run tasks concurrently
          and wait for their completion is *note asyncio.TaskGroup: 4d2.
          'TaskGroup' provides stronger safety guarantees than 'gather'
          for scheduling a nesting of subtasks: if a task (or a subtask,
          a task scheduled by a task) raises an exception, 'TaskGroup'
          will, while 'gather' will not, cancel the remaining scheduled
          tasks).
     Example:

          import asyncio

          async def factorial(name, number):
              f = 1
              for i in range(2, number + 1):
                  print(f"Task {name}: Compute factorial({number}), currently i={i}...")
                  await asyncio.sleep(1)
                  f *= i
              print(f"Task {name}: factorial({number}) = {f}")
              return f

          async def main():
              # Schedule three calls *concurrently*:
              L = await asyncio.gather(
                  factorial("A", 2),
                  factorial("B", 3),
                  factorial("C", 4),
              )
              print(L)

          asyncio.run(main())

          # Expected output:
          #
          #     Task A: Compute factorial(2), currently i=2...
          #     Task B: Compute factorial(3), currently i=2...
          #     Task C: Compute factorial(4), currently i=2...
          #     Task A: factorial(2) = 2
          #     Task B: Compute factorial(3), currently i=3...
          #     Task C: Compute factorial(4), currently i=3...
          #     Task B: factorial(3) = 6
          #     Task C: Compute factorial(4), currently i=4...
          #     Task C: factorial(4) = 24
          #     [2, 6, 24]

          Nota: If 'return_exceptions' is false, cancelling gather()
          after it has been marked done won’t cancel any submitted
          awaitables.  For instance, gather can be marked done after
          propagating an exception to the caller, therefore, calling
          ‘gather.cancel()’ after catching an exception (raised by one
          of the awaitables) from gather won’t cancel any other
          awaitables.

     Cambiato nella versione 3.7: If the 'gather' itself is cancelled,
     the cancellation is propagated regardless of 'return_exceptions'.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Deprecato dalla versione 3.10: Deprecation warning is emitted if no
     positional arguments are provided or not all positional arguments
     are Future-like objects and there is no running event loop.


File: python.info,  Node: Eager Task Factory,  Next: Shielding From Cancellation,  Prev: Running Tasks Concurrently,  Up: Coroutines and Tasks

5.19.1.14 Eager Task Factory
............................

 -- Funzione: asyncio.eager_task_factory (loop, coro, *, name=None,
          context=None)

     A task factory for eager task execution.

     When using this factory (via *note
     loop.set_task_factory(asyncio.eager_task_factory): 1c8.),
     coroutines begin execution synchronously during *note Task: 1c7.
     construction.  Tasks are only scheduled on the event loop if they
     block.  This can be a performance improvement as the overhead of
     loop scheduling is avoided for coroutines that complete
     synchronously.

     A common example where this is beneficial is coroutines which
     employ caching or memoization to avoid actual I/O when possible.

          Nota: Immediate execution of the coroutine is a semantic
          change.  If the coroutine returns or raises, the task is never
          scheduled to the event loop.  If the coroutine execution
          blocks, the task is scheduled to the event loop.  This change
          may introduce behavior changes to existing applications.  For
          example, the application’s task execution order is likely to
          change.

     Added in version 3.12.

 -- Funzione: asyncio.create_eager_task_factory
          (custom_task_constructor)

     Create an eager task factory, similar to *note
     eager_task_factory(): 6a3, using the provided
     'custom_task_constructor' when creating a new task instead of the
     default *note Task: 1c7.

     'custom_task_constructor' must be a 'callable' with the signature
     matching the signature of *note Task.__init__: 1c7.  The callable
     must return a *note asyncio.Task: 1c7.-compatible object.

     This function returns a 'callable' intended to be used as a task
     factory of an event loop via *note loop.set_task_factory(factory):
     1c8.).

     Added in version 3.12.


File: python.info,  Node: Shielding From Cancellation,  Next: Timeouts,  Prev: Eager Task Factory,  Up: Coroutines and Tasks

5.19.1.15 Shielding From Cancellation
.....................................

 -- Funzione: awaitable asyncio.shield (aw)

     Protect an *note awaitable object: 37b5. from being *note
     cancelled: 4d4.

     If 'aw' is a coroutine it is automatically scheduled as a Task.

     The statement:

          task = asyncio.create_task(something())
          res = await shield(task)

     is equivalent to:

          res = await something()

     'except' that if the coroutine containing it is cancelled, the Task
     running in ‘something()’ is not cancelled.  From the point of view
     of ‘something()’, the cancellation did not happen.  Although its
     caller is still cancelled, so the «await» expression still raises a
     *note CancelledError: 4d5.

     If ‘something()’ is cancelled by other means (i.e.  from within
     itself) that would also cancel ‘shield()’.

     If it is desired to completely ignore cancellation (not
     recommended) the ‘shield()’ function should be combined with a
     try/except clause, as follows:

          task = asyncio.create_task(something())
          try:
              res = await shield(task)
          except CancelledError:
              res = None

          Importante: Save a reference to tasks passed to this function,
          to avoid a task disappearing mid-execution.  The event loop
          only keeps weak references to tasks.  A task that isn’t
          referenced elsewhere may get garbage collected at any time,
          even before it’s done.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Deprecato dalla versione 3.10: Deprecation warning is emitted if
     'aw' is not Future-like object and there is no running event loop.


File: python.info,  Node: Timeouts,  Next: Waiting Primitives,  Prev: Shielding From Cancellation,  Up: Coroutines and Tasks

5.19.1.16 Timeouts
..................

 -- Funzione: asyncio.timeout (delay)

     Return an *note asynchronous context manager: 813. that can be used
     to limit the amount of time spent waiting on something.

     'delay' can either be ‘None’, or a float/int number of seconds to
     wait.  If 'delay' is ‘None’, no time limit will be applied; this
     can be useful if the delay is unknown when the context manager is
     created.

     In either case, the context manager can be rescheduled after
     creation using *note Timeout.reschedule(): 37c4.

     Example:

          async def main():
              async with asyncio.timeout(10):
                  await long_running_task()

     If ‘long_running_task’ takes more than 10 seconds to complete, the
     context manager will cancel the current task and handle the
     resulting *note asyncio.CancelledError: 4d5. internally,
     transforming it into a *note TimeoutError: a38. which can be caught
     and handled.

          Nota: The *note asyncio.timeout(): 815. context manager is
          what transforms the *note asyncio.CancelledError: 4d5. into a
          *note TimeoutError: a38, which means the *note TimeoutError:
          a38. can only be caught 'outside' of the context manager.

     Example of catching *note TimeoutError: a38.:

          async def main():
              try:
                  async with asyncio.timeout(10):
                      await long_running_task()
              except TimeoutError:
                  print("The long operation timed out, but we've handled it.")

              print("This statement will run regardless.")

     The context manager produced by *note asyncio.timeout(): 815. can
     be rescheduled to a different deadline and inspected.

      -- Classe: asyncio.Timeout (when)

          An *note asynchronous context manager: 813. for cancelling
          overdue coroutines.

          ‘when’ should be an absolute time at which the context should
          time out, as measured by the event loop’s clock:

             - If ‘when’ is ‘None’, the timeout will never trigger.

             - If ‘when < loop.time()’, the timeout will trigger on the
               next iteration of the event loop.

                -- Metodo: when () -> float | None

                    Return the current deadline, or ‘None’ if the
                    current deadline is not set.

                -- Metodo: reschedule (when: float | None)

                    Reschedule the timeout.

                -- Metodo: expired () -> bool

                    Return whether the context manager has exceeded its
                    deadline (expired).

     Example:

          async def main():
              try:
                  # We do not know the timeout when starting, so we pass ``None``.
                  async with asyncio.timeout(None) as cm:
                      # We know the timeout now, so we reschedule it.
                      new_deadline = get_running_loop().time() + 10
                      cm.reschedule(new_deadline)

                      await long_running_task()
              except TimeoutError:
                  pass

              if cm.expired():
                  print("Looks like we haven't finished on time.")

     Timeout context managers can be safely nested.

     Added in version 3.11.

 -- Funzione: asyncio.timeout_at (when)

     Similar to *note asyncio.timeout(): 815, except 'when' is the
     absolute time to stop waiting, or ‘None’.

     Example:

          async def main():
              loop = get_running_loop()
              deadline = loop.time() + 20
              try:
                  async with asyncio.timeout_at(deadline):
                      await long_running_task()
              except TimeoutError:
                  print("The long operation timed out, but we've handled it.")

              print("This statement will run regardless.")

     Added in version 3.11.

 -- Funzione: async asyncio.wait_for (aw, timeout)

     Wait for the 'aw' *note awaitable: 37b5. to complete with a
     timeout.

     If 'aw' is a coroutine it is automatically scheduled as a Task.

     'timeout' can either be ‘None’ or a float or int number of seconds
     to wait for.  If 'timeout' is ‘None’, block until the future
     completes.

     If a timeout occurs, it cancels the task and raises *note
     TimeoutError: a38.

     To avoid the task *note cancellation: 4d4, wrap it in *note
     shield(): c67.

     The function will wait until the future is actually cancelled, so
     the total wait time may exceed the 'timeout'.  If an exception
     happens during cancellation, it is propagated.

     If the wait is cancelled, the future 'aw' is also cancelled.
     Example:

          async def eternity():
              # Sleep for one hour
              await asyncio.sleep(3600)
              print('yay!')

          async def main():
              # Wait for at most 1 second
              try:
                  await asyncio.wait_for(eternity(), timeout=1.0)
              except TimeoutError:
                  print('timeout!')

          asyncio.run(main())

          # Expected output:
          #
          #     timeout!

     Cambiato nella versione 3.7: When 'aw' is cancelled due to a
     timeout, ‘wait_for’ waits for 'aw' to be cancelled.  Previously, it
     raised *note TimeoutError: a38. immediately.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Cambiato nella versione 3.11: Raises *note TimeoutError: a38.
     instead of *note asyncio.TimeoutError: 1a9d.


File: python.info,  Node: Waiting Primitives,  Next: Running in Threads,  Prev: Timeouts,  Up: Coroutines and Tasks

5.19.1.17 Waiting Primitives
............................

 -- Funzione: async asyncio.wait (aws, *, timeout=None,
          return_when=ALL_COMPLETED)

     Run *note Future: dc8. and *note Task: 1c7. instances in the 'aws'
     iterable concurrently and block until the condition specified by
     'return_when'.

     The 'aws' iterable must not be empty.

     Returns two sets of Tasks/Futures: ‘(done, pending)’.

     Usage:

          done, pending = await asyncio.wait(aws)

     'timeout' (a float or int), if specified, can be used to control
     the maximum number of seconds to wait before returning.

     Note that this function does not raise *note TimeoutError: a38.
     Futures or Tasks that aren’t done when the timeout occurs are
     simply returned in the second set.

     'return_when' indicates when this function should return.  It must
     be one of the following constants:

     Constant                                               Description
                                                            
     --------------------------------------------------------------------------------------------------------------
                                                            
      -- Dati: asyncio.FIRST_COMPLETED                      The function will return when any future finishes or
                                                            is cancelled.
                                                            
                                                            
      -- Dati: asyncio.FIRST_EXCEPTION                      The function will return when any future finishes by
                                                            raising an exception.  If no future raises an
                                                            exception then it is equivalent to
                                                            *note ALL_COMPLETED: 37cb.
                                                            
                                                            
      -- Dati: asyncio.ALL_COMPLETED                        The function will return when all futures finish or
                                                            are cancelled.
                                                            

     Unlike *note wait_for(): 816, ‘wait()’ does not cancel the futures
     when a timeout occurs.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Cambiato nella versione 3.11: Passing coroutine objects to ‘wait()’
     directly is forbidden.

     Cambiato nella versione 3.12: Added support for generators yielding
     tasks.

 -- Funzione: asyncio.as_completed (aws, *, timeout=None)

     Run *note awaitable objects: 37b5. in the 'aws' iterable
     concurrently.  The returned object can be iterated to obtain the
     results of the awaitables as they finish.

     The object returned by ‘as_completed()’ can be iterated as an *note
     asynchronous iterator: 4c8. or a plain *note iterator: 4c9.  When
     asynchronous iteration is used, the originally-supplied awaitables
     are yielded if they are tasks or futures.  This makes it easy to
     correlate previously-scheduled tasks with their results.  Example:

          ipv4_connect = create_task(open_connection("127.0.0.1", 80))
          ipv6_connect = create_task(open_connection("::1", 80))
          tasks = [ipv4_connect, ipv6_connect]

          async for earliest_connect in as_completed(tasks):
              # earliest_connect is done. The result can be obtained by
              # awaiting it or calling earliest_connect.result()
              reader, writer = await earliest_connect

              if earliest_connect is ipv6_connect:
                  print("IPv6 connection established.")
              else:
                  print("IPv4 connection established.")

     During asynchronous iteration, implicitly-created tasks will be
     yielded for supplied awaitables that aren’t tasks or futures.

     When used as a plain iterator, each iteration yields a new
     coroutine that returns the result or raises the exception of the
     next completed awaitable.  This pattern is compatible with Python
     versions older than 3.13:

          ipv4_connect = create_task(open_connection("127.0.0.1", 80))
          ipv6_connect = create_task(open_connection("::1", 80))
          tasks = [ipv4_connect, ipv6_connect]

          for next_connect in as_completed(tasks):
              # next_connect is not one of the original task objects. It must be
              # awaited to obtain the result value or raise the exception of the
              # awaitable that finishes next.
              reader, writer = await next_connect

     A *note TimeoutError: a38. is raised if the timeout occurs before
     all awaitables are done.  This is raised by the ‘async for’ loop
     during asynchronous iteration or by the coroutines yielded during
     plain iteration.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Deprecato dalla versione 3.10: Deprecation warning is emitted if
     not all awaitable objects in the 'aws' iterable are Future-like
     objects and there is no running event loop.

     Cambiato nella versione 3.12: Added support for generators yielding
     tasks.

     Cambiato nella versione 3.13: The result can now be used as either
     an *note asynchronous iterator: 4c8. or as a plain *note iterator:
     4c9. (previously it was only a plain iterator).


File: python.info,  Node: Running in Threads,  Next: Scheduling From Other Threads,  Prev: Waiting Primitives,  Up: Coroutines and Tasks

5.19.1.18 Running in Threads
............................

 -- Funzione: async asyncio.to_thread (func, /, *args, **kwargs)

     Asynchronously run function 'func' in a separate thread.

     Any *args and **kwargs supplied for this function are directly
     passed to 'func'.  Also, the current *note contextvars.Context:
     177. is propagated, allowing context variables from the event loop
     thread to be accessed in the separate thread.

     Return a coroutine that can be awaited to get the eventual result
     of 'func'.

     This coroutine function is primarily intended to be used for
     executing IO-bound functions/methods that would otherwise block the
     event loop if they were run in the main thread.  For example:

          def blocking_io():
              print(f"start blocking_io at {time.strftime('%X')}")
              # Note that time.sleep() can be replaced with any blocking
              # IO-bound operation, such as file operations.
              time.sleep(1)
              print(f"blocking_io complete at {time.strftime('%X')}")

          async def main():
              print(f"started main at {time.strftime('%X')}")

              await asyncio.gather(
                  asyncio.to_thread(blocking_io),
                  asyncio.sleep(1))

              print(f"finished main at {time.strftime('%X')}")


          asyncio.run(main())

          # Expected output:
          #
          # started main at 19:50:53
          # start blocking_io at 19:50:53
          # blocking_io complete at 19:50:54
          # finished main at 19:50:54

     Directly calling ‘blocking_io()’ in any coroutine would block the
     event loop for its duration, resulting in an additional 1 second of
     run time.  Instead, by using ‘asyncio.to_thread()’, we can run it
     in a separate thread without blocking the event loop.

          Nota: Due to the *note GIL: 164, ‘asyncio.to_thread()’ can
          typically only be used to make IO-bound functions
          non-blocking.  However, for extension modules that release the
          GIL or alternative Python implementations that don’t have one,
          ‘asyncio.to_thread()’ can also be used for CPU-bound
          functions.

     Added in version 3.9.


File: python.info,  Node: Scheduling From Other Threads,  Next: Introspection,  Prev: Running in Threads,  Up: Coroutines and Tasks

5.19.1.19 Scheduling From Other Threads
.......................................

 -- Funzione: asyncio.run_coroutine_threadsafe (coro, loop)

     Submit a coroutine to the given event loop.  Thread-safe.

     Return a *note concurrent.futures.Future: 13ba. to wait for the
     result from another OS thread.

     This function is meant to be called from a different OS thread than
     the one where the event loop is running.  Example:

          def in_thread(loop: asyncio.AbstractEventLoop) -> None:
              # Run some blocking IO
              pathlib.Path("example.txt").write_text("hello world", encoding="utf8")

              # Create a coroutine
              coro = asyncio.sleep(1, result=3)

              # Submit the coroutine to a given loop
              future = asyncio.run_coroutine_threadsafe(coro, loop)

              # Wait for the result with an optional timeout argument
              assert future.result(timeout=2) == 3

          async def amain() -> None:
              # Get the running loop
              loop = asyncio.get_running_loop()

              # Run something in a thread
              await asyncio.to_thread(in_thread, loop)

     It’s also possible to run the other way around.  Example:

          @contextlib.contextmanager
          def loop_in_thread() -> Generator[asyncio.AbstractEventLoop]:
              loop_fut = concurrent.futures.Future[asyncio.AbstractEventLoop]()
              stop_event = asyncio.Event()

              async def main() -> None:
                  loop_fut.set_result(asyncio.get_running_loop())
                  await stop_event.wait()

              with concurrent.futures.ThreadPoolExecutor(1) as tpe:
                  complete_fut = tpe.submit(asyncio.run, main())
                  for fut in concurrent.futures.as_completed((loop_fut, complete_fut)):
                      if fut is loop_fut:
                          loop = loop_fut.result()
                          try:
                              yield loop
                          finally:
                              loop.call_soon_threadsafe(stop_event.set)
                      else:
                          fut.result()

          # Create a loop in another thread
          with loop_in_thread() as loop:
              # Create a coroutine
              coro = asyncio.sleep(1, result=3)

              # Submit the coroutine to a given loop
              future = asyncio.run_coroutine_threadsafe(coro, loop)

              # Wait for the result with an optional timeout argument
              assert future.result(timeout=2) == 3

     If an exception is raised in the coroutine, the returned Future
     will be notified.  It can also be used to cancel the task in the
     event loop:

          try:
              result = future.result(timeout)
          except TimeoutError:
              print('The coroutine took too long, cancelling the task...')
              future.cancel()
          except Exception as exc:
              print(f'The coroutine raised an exception: {exc!r}')
          else:
              print(f'The coroutine returned: {result!r}')

     See the *note concurrency and multithreading: 37ce. section of the
     documentation.

     Unlike other asyncio functions this function requires the 'loop'
     argument to be passed explicitly.

     Added in version 3.5.1.


File: python.info,  Node: Introspection,  Next: Task Object,  Prev: Scheduling From Other Threads,  Up: Coroutines and Tasks

5.19.1.20 Introspection
.......................

 -- Funzione: asyncio.current_task (loop=None)

     Return the currently running *note Task: 1c7. instance, or ‘None’
     if no task is running.

     If 'loop' is ‘None’ *note get_running_loop(): d03. is used to get
     the current loop.

     Added in version 3.7.

 -- Funzione: asyncio.all_tasks (loop=None)

     Return a set of not yet finished *note Task: 1c7. objects run by
     the loop.

     If 'loop' is ‘None’, *note get_running_loop(): d03. is used for
     getting current loop.

     Added in version 3.7.

 -- Funzione: asyncio.iscoroutine (obj)

     Return ‘True’ if 'obj' is a coroutine object.

     Added in version 3.4.


File: python.info,  Node: Task Object,  Prev: Introspection,  Up: Coroutines and Tasks

5.19.1.21 Task Object
.....................

 -- Classe: asyncio.Task (coro, *, loop=None, name=None, context=None,
          eager_start=False)

     A *note Future-like: dc8. object that runs a Python *note
     coroutine: 379e.  Not thread-safe.

     Tasks are used to run coroutines in event loops.  If a coroutine
     awaits on a Future, the Task suspends the execution of the
     coroutine and waits for the completion of the Future.  When the
     Future is 'done', the execution of the wrapped coroutine resumes.

     Event loops use cooperative scheduling: an event loop runs one Task
     at a time.  While a Task awaits for the completion of a Future, the
     event loop runs other Tasks, callbacks, or performs IO operations.

     Use the high-level *note asyncio.create_task(): 1c9. function to
     create Tasks, or the low-level *note loop.create_task(): 1ca. or
     *note ensure_future(): e73. functions.  Manual instantiation of
     Tasks is discouraged.

     To cancel a running Task use the *note cancel(): 4d4. method.
     Calling it will cause the Task to throw a *note CancelledError:
     4d5. exception into the wrapped coroutine.  If a coroutine is
     awaiting on a Future object during cancellation, the Future object
     will be cancelled.

     *note cancelled(): 37d2. can be used to check if the Task was
     cancelled.  The method returns ‘True’ if the wrapped coroutine did
     not suppress the *note CancelledError: 4d5. exception and was
     actually cancelled.

     *note asyncio.Task: 1c7. inherits from *note Future: dc8. all of
     its APIs except *note Future.set_result(): 37d3. and *note
     Future.set_exception(): e7a.

     An optional keyword-only 'context' argument allows specifying a
     custom *note contextvars.Context: 177. for the 'coro' to run in.
     If no 'context' is provided, the Task copies the current context
     and later runs its coroutine in the copied context.

     An optional keyword-only 'eager_start' argument allows eagerly
     starting the execution of the *note asyncio.Task: 1c7. at task
     creation time.  If set to ‘True’ and the event loop is running, the
     task will start executing the coroutine immediately, until the
     first time the coroutine blocks.  If the coroutine returns or
     raises without blocking, the task will be finished eagerly and will
     skip scheduling to the event loop.

     Cambiato nella versione 3.7: Added support for the *note
     contextvars: 28. module.

     Cambiato nella versione 3.8: Added the 'name' parameter.

     Deprecato dalla versione 3.10: Deprecation warning is emitted if
     'loop' is not specified and there is no running event loop.

     Cambiato nella versione 3.11: Added the 'context' parameter.

     Cambiato nella versione 3.12: Added the 'eager_start' parameter.

      -- Metodo: done ()

          Return ‘True’ if the Task is 'done'.

          A Task is 'done' when the wrapped coroutine either returned a
          value, raised an exception, or the Task was cancelled.

      -- Metodo: result ()

          Return the result of the Task.

          If the Task is 'done', the result of the wrapped coroutine is
          returned (or if the coroutine raised an exception, that
          exception is re-raised.)

          If the Task has been 'cancelled', this method raises a *note
          CancelledError: 4d5. exception.

          If the Task’s result isn’t yet available, this method raises
          an *note InvalidStateError: 37d6. exception.

      -- Metodo: exception ()

          Return the exception of the Task.

          If the wrapped coroutine raised an exception that exception is
          returned.  If the wrapped coroutine returned normally this
          method returns ‘None’.

          If the Task has been 'cancelled', this method raises a *note
          CancelledError: 4d5. exception.

          If the Task isn’t 'done' yet, this method raises an *note
          InvalidStateError: 37d6. exception.

      -- Metodo: add_done_callback (callback, *, context=None)

          Add a callback to be run when the Task is 'done'.

          This method should only be used in low-level callback-based
          code.

          See the documentation of *note Future.add_done_callback():
          d00. for more details.

      -- Metodo: remove_done_callback (callback)

          Remove 'callback' from the callbacks list.

          This method should only be used in low-level callback-based
          code.

          See the documentation of *note Future.remove_done_callback():
          18f9. for more details.

      -- Metodo: get_stack (*, limit=None)

          Return the list of stack frames for this Task.

          If the wrapped coroutine is not done, this returns the stack
          where it is suspended.  If the coroutine has completed
          successfully or was cancelled, this returns an empty list.  If
          the coroutine was terminated by an exception, this returns the
          list of traceback frames.

          The frames are always ordered from oldest to newest.

          Only one stack frame is returned for a suspended coroutine.

          The optional 'limit' argument sets the maximum number of
          frames to return; by default all available frames are
          returned.  The ordering of the returned list differs depending
          on whether a stack or a traceback is returned: the newest
          frames of a stack are returned, but the oldest frames of a
          traceback are returned.  (This matches the behavior of the
          traceback module.)

      -- Metodo: print_stack (*, limit=None, file=None)

          Print the stack or traceback for this Task.

          This produces output similar to that of the traceback module
          for the frames retrieved by *note get_stack(): 37da.

          The 'limit' argument is passed to *note get_stack(): 37da.
          directly.

          The 'file' argument is an I/O stream to which the output is
          written; by default output is written to *note sys.stdout:
          ccf.

      -- Metodo: get_coro ()

          Return the coroutine object wrapped by the *note Task: 1c7.

               Nota: This will return ‘None’ for Tasks which have
               already completed eagerly.  See the *note Eager Task
               Factory: 37c0.

          Added in version 3.8.

          Cambiato nella versione 3.12: Newly added eager task execution
          means result may be ‘None’.

      -- Metodo: get_context ()

          Return the *note contextvars.Context: 177. object associated
          with the task.

          Added in version 3.12.

      -- Metodo: get_name ()

          Return the name of the Task.

          If no name has been explicitly assigned to the Task, the
          default asyncio Task implementation generates a default name
          during instantiation.

          Added in version 3.8.

      -- Metodo: set_name (value)

          Set the name of the Task.

          The 'value' argument can be any object, which is then
          converted to a string.

          In the default Task implementation, the name will be visible
          in the *note repr(): 1c1. output of a task object.

          Added in version 3.8.

      -- Metodo: cancel (msg=None)

          Request the Task to be cancelled.

          If the Task is already 'done' or 'cancelled', return ‘False’,
          otherwise, return ‘True’.

          The method arranges for a *note CancelledError: 4d5. exception
          to be thrown into the wrapped coroutine on the next cycle of
          the event loop.

          The coroutine then has a chance to clean up or even deny the
          request by suppressing the exception with a *note try: 8f9. …
          … ‘except CancelledError’ … *note finally: 1b0. block.
          Therefore, unlike *note Future.cancel(): 1b91, *note
          Task.cancel(): 4d4. does not guarantee that the Task will be
          cancelled, although suppressing cancellation completely is not
          common and is actively discouraged.  Should the coroutine
          nevertheless decide to suppress the cancellation, it needs to
          call *note Task.uncancel(): 4d7. in addition to catching the
          exception.

          Cambiato nella versione 3.9: Added the 'msg' parameter.

          Cambiato nella versione 3.11: The ‘msg’ parameter is
          propagated from cancelled task to its awaiter.

          The following example illustrates how coroutines can intercept
          the cancellation request:

               async def cancel_me():
                   print('cancel_me(): before sleep')

                   try:
                       # Wait for 1 hour
                       await asyncio.sleep(3600)
                   except asyncio.CancelledError:
                       print('cancel_me(): cancel sleep')
                       raise
                   finally:
                       print('cancel_me(): after sleep')

               async def main():
                   # Create a "cancel_me" Task
                   task = asyncio.create_task(cancel_me())

                   # Wait for 1 second
                   await asyncio.sleep(1)

                   task.cancel()
                   try:
                       await task
                   except asyncio.CancelledError:
                       print("main(): cancel_me is cancelled now")

               asyncio.run(main())

               # Expected output:
               #
               #     cancel_me(): before sleep
               #     cancel_me(): cancel sleep
               #     cancel_me(): after sleep
               #     main(): cancel_me is cancelled now

      -- Metodo: cancelled ()

          Return ‘True’ if the Task is 'cancelled'.

          The Task is 'cancelled' when the cancellation was requested
          with *note cancel(): 4d4. and the wrapped coroutine propagated
          the *note CancelledError: 4d5. exception thrown into it.

      -- Metodo: uncancel ()

          Decrement the count of cancellation requests to this Task.

          Returns the remaining number of cancellation requests.

          Note that once execution of a cancelled task completed,
          further calls to *note uncancel(): 4d7. are ineffective.

          Added in version 3.11.

          This method is used by asyncio’s internals and isn’t expected
          to be used by end-user code.  In particular, if a Task gets
          successfully uncancelled, this allows for elements of
          structured concurrency like *note Task Groups: 37ba. and *note
          asyncio.timeout(): 815. to continue running, isolating
          cancellation to the respective structured block.  For example:

               async def make_request_with_timeout():
                   try:
                       async with asyncio.timeout(1):
                           # Structured block affected by the timeout:
                           await make_request()
                           await make_another_request()
                   except TimeoutError:
                       log("There was a timeout")
                   # Outer code not affected by the timeout:
                   await unrelated_code()

          While the block with ‘make_request()’ and
          ‘make_another_request()’ might get cancelled due to the
          timeout, ‘unrelated_code()’ should continue running even in
          case of the timeout.  This is implemented with *note
          uncancel(): 4d7.  *note TaskGroup: 4d2. context managers use
          *note uncancel(): 4d7. in a similar fashion.

          If end-user code is, for some reason, suppressing cancellation
          by catching *note CancelledError: 4d5, it needs to call this
          method to remove the cancellation state.

          When this method decrements the cancellation count to zero,
          the method checks if a previous *note cancel(): 4d4. call had
          arranged for *note CancelledError: 4d5. to be thrown into the
          task.  If it hasn’t been thrown yet, that arrangement will be
          rescinded (by resetting the internal ‘_must_cancel’ flag).

     Cambiato nella versione 3.13: Changed to rescind pending
     cancellation requests upon reaching zero.

      -- Metodo: cancelling ()

          Return the number of pending cancellation requests to this
          Task, i.e., the number of calls to *note cancel(): 4d4. less
          the number of *note uncancel(): 4d7. calls.

          Note that if this number is greater than zero but the Task is
          still executing, *note cancelled(): 37d2. will still return
          ‘False’.  This is because this number can be lowered by
          calling *note uncancel(): 4d7, which can lead to the task not
          being cancelled after all if the cancellation requests go down
          to zero.

          This method is used by asyncio’s internals and isn’t expected
          to be used by end-user code.  See *note uncancel(): 4d7. for
          more details.

          Added in version 3.11.


File: python.info,  Node: Streams,  Next: Synchronization Primitives,  Prev: Coroutines and Tasks,  Up: asyncio — Asynchronous I/O

5.19.1.22 Streams
.................

'Source code:' Lib/asyncio/streams.py(1)

__________________________________________________________________

Streams are high-level async/await-ready primitives to work with network
connections.  Streams allow sending and receiving data without using
callbacks or low-level protocols and transports.  Here is an example of
a TCP echo client written using asyncio streams:

     import asyncio

     async def tcp_echo_client(message):
         reader, writer = await asyncio.open_connection(
             '127.0.0.1', 8888)

         print(f'Send: {message!r}')
         writer.write(message.encode())
         await writer.drain()

         data = await reader.read(100)
         print(f'Received: {data.decode()!r}')

         print('Close the connection')
         writer.close()
         await writer.wait_closed()

     asyncio.run(tcp_echo_client('Hello World!'))

See also the *note Examples: 37e1. section below.

Stream Functions
................

The following top-level asyncio functions can be used to create and work
with streams:

 -- Funzione: async asyncio.open_connection (host=None, port=None, *,
          limit=None, ssl=None, family=0, proto=0, flags=0, sock=None,
          local_addr=None, server_hostname=None,
          ssl_handshake_timeout=None, ssl_shutdown_timeout=None,
          happy_eyeballs_delay=None, interleave=None)

     Establish a network connection and return a pair of ‘(reader,
     writer)’ objects.

     The returned 'reader' and 'writer' objects are instances of *note
     StreamReader: 1c65. and *note StreamWriter: 1a58. classes.

     'limit' determines the buffer size limit used by the returned *note
     StreamReader: 1c65. instance.  By default the 'limit' is set to 64
     KiB.

     The rest of the arguments are passed directly to *note
     loop.create_connection(): 819.

          Nota: The 'sock' argument transfers ownership of the socket to
          the *note StreamWriter: 1a58. created.  To close the socket,
          call its *note close(): 37e2. method.

     Cambiato nella versione 3.7: Added the 'ssl_handshake_timeout'
     parameter.

     Cambiato nella versione 3.8: Added the 'happy_eyeballs_delay' and
     'interleave' parameters.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Cambiato nella versione 3.11: Added the 'ssl_shutdown_timeout'
     parameter.

 -- Funzione: async asyncio.start_server (client_connected_cb,
          host=None, port=None, *, limit=None, family=socket.AF_UNSPEC,
          flags=socket.AI_PASSIVE, sock=None, backlog=100, ssl=None,
          reuse_address=None, reuse_port=None, keep_alive=None,
          ssl_handshake_timeout=None, ssl_shutdown_timeout=None,
          start_serving=True)

     Start a socket server.

     The 'client_connected_cb' callback is called whenever a new client
     connection is established.  It receives a ‘(reader, writer)’ pair
     as two arguments, instances of the *note StreamReader: 1c65. and
     *note StreamWriter: 1a58. classes.

     'client_connected_cb' can be a plain callable or a *note coroutine
     function: 379e.; if it is a coroutine function, it will be
     automatically scheduled as a *note Task: 1c7.

     'limit' determines the buffer size limit used by the returned *note
     StreamReader: 1c65. instance.  By default the 'limit' is set to 64
     KiB.

     The rest of the arguments are passed directly to *note
     loop.create_server(): d0b.

          Nota: The 'sock' argument transfers ownership of the socket to
          the server created.  To close the socket, call the server’s
          *note close(): 37e3. method.

     Cambiato nella versione 3.7: Added the 'ssl_handshake_timeout' and
     'start_serving' parameters.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Cambiato nella versione 3.11: Added the 'ssl_shutdown_timeout'
     parameter.

     Cambiato nella versione 3.13: Added the 'keep_alive' parameter.

Unix Sockets
............

 -- Funzione: async asyncio.open_unix_connection (path=None, *,
          limit=None, ssl=None, sock=None, server_hostname=None,
          ssl_handshake_timeout=None, ssl_shutdown_timeout=None)

     Establish a Unix socket connection and return a pair of ‘(reader,
     writer)’.

     Similar to *note open_connection(): d10. but operates on Unix
     sockets.

     See also the documentation of *note loop.create_unix_connection():
     37e5.

          Nota: The 'sock' argument transfers ownership of the socket to
          the *note StreamWriter: 1a58. created.  To close the socket,
          call its *note close(): 37e2. method.

     *note Availability: 2128.: Unix.

     Cambiato nella versione 3.7: Added the 'ssl_handshake_timeout'
     parameter.  The 'path' parameter can now be a *note path-like
     object: 5a1.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Cambiato nella versione 3.11: Added the 'ssl_shutdown_timeout'
     parameter.

 -- Funzione: async asyncio.start_unix_server (client_connected_cb,
          path=None, *, limit=None, sock=None, backlog=100, ssl=None,
          ssl_handshake_timeout=None, ssl_shutdown_timeout=None,
          start_serving=True, cleanup_socket=True)

     Start a Unix socket server.

     Similar to *note start_server(): d11. but works with Unix sockets.

     If 'cleanup_socket' is true then the Unix socket will automatically
     be removed from the filesystem when the server is closed, unless
     the socket has been replaced after the server has been created.

     See also the documentation of *note loop.create_unix_server(): 4cb.

          Nota: The 'sock' argument transfers ownership of the socket to
          the server created.  To close the socket, call the server’s
          *note close(): 37e3. method.

     *note Availability: 2128.: Unix.

     Cambiato nella versione 3.7: Added the 'ssl_handshake_timeout' and
     'start_serving' parameters.  The 'path' parameter can now be a
     *note path-like object: 5a1.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Cambiato nella versione 3.11: Added the 'ssl_shutdown_timeout'
     parameter.

     Cambiato nella versione 3.13: Added the 'cleanup_socket' parameter.

* Menu:

* StreamReader::
* StreamWriter::
* Examples: Examples<16>.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/streams.py


File: python.info,  Node: StreamReader,  Next: StreamWriter,  Up: Streams

5.19.1.23 StreamReader
......................

 -- Classe: asyncio.StreamReader

     Represents a reader object that provides APIs to read data from the
     IO stream.  As an *note asynchronous iterable: f76, the object
     supports the *note async for: ca3. statement.

     It is not recommended to instantiate 'StreamReader' objects
     directly; use *note open_connection(): d10. and *note
     start_server(): d11. instead.

      -- Metodo: feed_eof ()

          Acknowledge the EOF.

      -- Metodo: async read (n=-1)

          Read up to 'n' bytes from the stream.

          If 'n' is not provided or set to ‘-1’, read until EOF, then
          return all read *note bytes: 192.  If EOF was received and the
          internal buffer is empty, return an empty ‘bytes’ object.

          If 'n' is ‘0’, return an empty ‘bytes’ object immediately.

          If 'n' is positive, return at most 'n' available ‘bytes’ as
          soon as at least 1 byte is available in the internal buffer.
          If EOF is received before any byte is read, return an empty
          ‘bytes’ object.

      -- Metodo: async readline ()

          Read one line, where «line» is a sequence of bytes ending with
          ‘\n’.

          If EOF is received and ‘\n’ was not found, the method returns
          partially read data.

          If EOF is received and the internal buffer is empty, return an
          empty ‘bytes’ object.

      -- Metodo: async readexactly (n)

          Read exactly 'n' bytes.

          Raise an *note IncompleteReadError: 1cd0. if EOF is reached
          before 'n' can be read.  Use the *note
          IncompleteReadError.partial: 37eb. attribute to get the
          partially read data.

      -- Metodo: async readuntil (separator=b'\n')

          Read data from the stream until 'separator' is found.

          On success, the data and separator will be removed from the
          internal buffer (consumed).  Returned data will include the
          separator at the end.

          If the amount of data read exceeds the configured stream
          limit, a *note LimitOverrunError: 37ec. exception is raised,
          and the data is left in the internal buffer and can be read
          again.

          If EOF is reached before the complete separator is found, an
          *note IncompleteReadError: 1cd0. exception is raised, and the
          internal buffer is reset.  The *note
          IncompleteReadError.partial: 37eb. attribute may contain a
          portion of the separator.

          The 'separator' may also be a tuple of separators.  In this
          case the return value will be the shortest possible that has
          any separator as the suffix.  For the purposes of *note
          LimitOverrunError: 37ec, the shortest possible separator is
          considered to be the one that matched.

          Added in version 3.5.2.

          Cambiato nella versione 3.13: The 'separator' parameter may
          now be a *note tuple: 614. of separators.

      -- Metodo: at_eof ()

          Return ‘True’ if the buffer is empty and *note feed_eof():
          37e8. was called.


File: python.info,  Node: StreamWriter,  Next: Examples<16>,  Prev: StreamReader,  Up: Streams

5.19.1.24 StreamWriter
......................

 -- Classe: asyncio.StreamWriter

     Represents a writer object that provides APIs to write data to the
     IO stream.

     It is not recommended to instantiate 'StreamWriter' objects
     directly; use *note open_connection(): d10. and *note
     start_server(): d11. instead.

      -- Metodo: write (data)

          The method attempts to write the 'data' to the underlying
          socket immediately.  If that fails, the data is queued in an
          internal write buffer until it can be sent.

          The 'data' buffer should be a bytes, bytearray, or
          C-contiguous one-dimensional memoryview object.

          The method should be used along with the ‘drain()’ method:

               stream.write(data)
               await stream.drain()

      -- Metodo: writelines (data)

          The method writes a list (or any iterable) of bytes to the
          underlying socket immediately.  If that fails, the data is
          queued in an internal write buffer until it can be sent.

          The method should be used along with the ‘drain()’ method:

               stream.writelines(lines)
               await stream.drain()

      -- Metodo: close ()

          The method closes the stream and the underlying socket.

          The method should be used, though not mandatory, along with
          the ‘wait_closed()’ method:

               stream.close()
               await stream.wait_closed()

      -- Metodo: can_write_eof ()

          Return ‘True’ if the underlying transport supports the *note
          write_eof(): 37f2. method, ‘False’ otherwise.

      -- Metodo: write_eof ()

          Close the write end of the stream after the buffered write
          data is flushed.

      -- Attributo: transport

          Return the underlying asyncio transport.

      -- Metodo: get_extra_info (name, default=None)

          Access optional transport information; see *note
          BaseTransport.get_extra_info(): c95. for details.

      -- Metodo: async drain ()

          Wait until it is appropriate to resume writing to the stream.
          Example:

               writer.write(data)
               await writer.drain()

          This is a flow control method that interacts with the
          underlying IO write buffer.  When the size of the buffer
          reaches the high watermark, 'drain()' blocks until the size of
          the buffer is drained down to the low watermark and writing
          can be resumed.  When there is nothing to wait for, the *note
          drain(): 1b11. returns immediately.

      -- Metodo: async start_tls (sslcontext, *, server_hostname=None,
               ssl_handshake_timeout=None, ssl_shutdown_timeout=None)

          Upgrade an existing stream-based connection to TLS.

          Parameters:

             * 'sslcontext': a configured instance of *note SSLContext:
               357.

             * 'server_hostname': sets or overrides the host name that
               the target server’s certificate will be matched against.

             * 'ssl_handshake_timeout' is the time in seconds to wait
               for the TLS handshake to complete before aborting the
               connection.  ‘60.0’ seconds if ‘None’ (default).

             * 'ssl_shutdown_timeout' is the time in seconds to wait for
               the SSL shutdown to complete before aborting the
               connection.  ‘30.0’ seconds if ‘None’ (default).

          Added in version 3.11.

          Cambiato nella versione 3.12: Added the 'ssl_shutdown_timeout'
          parameter.

      -- Metodo: is_closing ()

          Return ‘True’ if the stream is closed or in the process of
          being closed.

          Added in version 3.7.

      -- Metodo: async wait_closed ()

          Wait until the stream is closed.

          Should be called after *note close(): 37e2. to wait until the
          underlying connection is closed, ensuring that all data has
          been flushed before e.g.  exiting the program.

          Added in version 3.7.


File: python.info,  Node: Examples<16>,  Prev: StreamWriter,  Up: Streams

5.19.1.25 Examples
..................

* Menu:

* TCP echo client using streams::
* TCP echo server using streams::
* Get HTTP headers::
* Register an open socket to wait for data using streams::


File: python.info,  Node: TCP echo client using streams,  Next: TCP echo server using streams,  Up: Examples<16>

5.19.1.26 TCP echo client using streams
.......................................

TCP echo client using the *note asyncio.open_connection(): d10.
function:

     import asyncio

     async def tcp_echo_client(message):
         reader, writer = await asyncio.open_connection(
             '127.0.0.1', 8888)

         print(f'Send: {message!r}')
         writer.write(message.encode())
         await writer.drain()

         data = await reader.read(100)
         print(f'Received: {data.decode()!r}')

         print('Close the connection')
         writer.close()
         await writer.wait_closed()

     asyncio.run(tcp_echo_client('Hello World!'))

Vedi anche
..........

The *note TCP echo client protocol: 37f7. example uses the low-level
*note loop.create_connection(): 819. method.


File: python.info,  Node: TCP echo server using streams,  Next: Get HTTP headers,  Prev: TCP echo client using streams,  Up: Examples<16>

5.19.1.27 TCP echo server using streams
.......................................

TCP echo server using the *note asyncio.start_server(): d11. function:

     import asyncio

     async def handle_echo(reader, writer):
         data = await reader.read(100)
         message = data.decode()
         addr = writer.get_extra_info('peername')

         print(f"Received {message!r} from {addr!r}")

         print(f"Send: {message!r}")
         writer.write(data)
         await writer.drain()

         print("Close the connection")
         writer.close()
         await writer.wait_closed()

     async def main():
         server = await asyncio.start_server(
             handle_echo, '127.0.0.1', 8888)

         addrs = ', '.join(str(sock.getsockname()) for sock in server.sockets)
         print(f'Serving on {addrs}')

         async with server:
             await server.serve_forever()

     asyncio.run(main())

Vedi anche
..........

The *note TCP echo server protocol: 37fa. example uses the *note
loop.create_server(): d0b. method.


File: python.info,  Node: Get HTTP headers,  Next: Register an open socket to wait for data using streams,  Prev: TCP echo server using streams,  Up: Examples<16>

5.19.1.28 Get HTTP headers
..........................

Simple example querying HTTP headers of the URL passed on the command
line:

     import asyncio
     import urllib.parse
     import sys

     async def print_http_headers(url):
         url = urllib.parse.urlsplit(url)
         if url.scheme == 'https':
             reader, writer = await asyncio.open_connection(
                 url.hostname, 443, ssl=True)
         else:
             reader, writer = await asyncio.open_connection(
                 url.hostname, 80)

         query = (
             f"HEAD {url.path or '/'} HTTP/1.0\r\n"
             f"Host: {url.hostname}\r\n"
             f"\r\n"
         )

         writer.write(query.encode('latin-1'))
         while True:
             line = await reader.readline()
             if not line:
                 break

             line = line.decode('latin1').rstrip()
             if line:
                 print(f'HTTP header> {line}')

         # Ignore the body, close the socket
         writer.close()
         await writer.wait_closed()

     url = sys.argv[1]
     asyncio.run(print_http_headers(url))

Usage:

     python example.py http://example.com/path/page.html

or with HTTPS:

     python example.py https://example.com/path/page.html


File: python.info,  Node: Register an open socket to wait for data using streams,  Prev: Get HTTP headers,  Up: Examples<16>

5.19.1.29 Register an open socket to wait for data using streams
................................................................

Coroutine waiting until a socket receives data using the *note
open_connection(): d10. function:

     import asyncio
     import socket

     async def wait_for_data():
         # Get a reference to the current event loop because
         # we want to access low-level APIs.
         loop = asyncio.get_running_loop()

         # Create a pair of connected sockets.
         rsock, wsock = socket.socketpair()

         # Register the open socket to wait for data.
         reader, writer = await asyncio.open_connection(sock=rsock)

         # Simulate the reception of data from the network
         loop.call_soon(wsock.send, 'abc'.encode())

         # Wait for data
         data = await reader.read(100)

         # Got data, we are done: close the socket
         print("Received:", data.decode())
         writer.close()
         await writer.wait_closed()

         # Close the second socket
         wsock.close()

     asyncio.run(wait_for_data())

Vedi anche
..........

The *note register an open socket to wait for data using a protocol:
37fe. example uses a low-level protocol and the *note
loop.create_connection(): 819. method.

The *note watch a file descriptor for read events: 37ff. example uses
the low-level *note loop.add_reader(): 3800. method to watch a file
descriptor.


File: python.info,  Node: Synchronization Primitives,  Next: Subprocesses,  Prev: Streams,  Up: asyncio — Asynchronous I/O

5.19.1.30 Synchronization Primitives
....................................

'Source code:' Lib/asyncio/locks.py(1)

__________________________________________________________________

asyncio synchronization primitives are designed to be similar to those
of the *note threading: f3. module with two important caveats:

   * asyncio primitives are not thread-safe, therefore they should not
     be used for OS thread synchronization (use *note threading: f3. for
     that);

   * methods of these synchronization primitives do not accept the
     'timeout' argument; use the *note asyncio.wait_for(): 816. function
     to perform operations with timeouts.

asyncio has the following basic synchronization primitives:

   * *note Lock: c68.

   * *note Event: 2f4.

   * *note Condition: c69.

   * *note Semaphore: c6a.

   * *note BoundedSemaphore: c6b.

   * *note Barrier: 817.

__________________________________________________________________

* Menu:

* Lock::
* Event::
* Condition::
* Semaphore::
* BoundedSemaphore::
* Barrier::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/asyncio/locks.py


File: python.info,  Node: Lock,  Next: Event,  Up: Synchronization Primitives

5.19.1.31 Lock
..............

 -- Classe: asyncio.Lock

     Implements a mutex lock for asyncio tasks.  Not thread-safe.

     An asyncio lock can be used to guarantee exclusive access to a
     shared resource.

     The preferred way to use a Lock is an *note async with: 185.
     statement:

          lock = asyncio.Lock()

          # ... later
          async with lock:
              # access shared state

     which is equivalent to:

          lock = asyncio.Lock()

          # ... later
          await lock.acquire()
          try:
              # access shared state
          finally:
              lock.release()

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

      -- Metodo: async acquire ()

          Acquire the lock.

          This method waits until the lock is 'unlocked', sets it to
          'locked' and returns ‘True’.

          When more than one coroutine is blocked in *note acquire():
          3805. waiting for the lock to be unlocked, only one coroutine
          eventually proceeds.

          Acquiring a lock is 'fair': the coroutine that proceeds will
          be the first coroutine that started waiting on the lock.

      -- Metodo: release ()

          Release the lock.

          When the lock is 'locked', reset it to 'unlocked' and return.

          If the lock is 'unlocked', a *note RuntimeError: 244. is
          raised.

      -- Metodo: locked ()

          Return ‘True’ if the lock is 'locked'.


File: python.info,  Node: Event,  Next: Condition,  Prev: Lock,  Up: Synchronization Primitives

5.19.1.32 Event
...............

 -- Classe: asyncio.Event

     An event object.  Not thread-safe.

     An asyncio event can be used to notify multiple asyncio tasks that
     some event has happened.

     An Event object manages an internal flag that can be set to 'true'
     with the *note set(): 3809. method and reset to 'false' with the
     *note clear(): 380a. method.  The *note wait(): 380b. method blocks
     until the flag is set to 'true'.  The flag is set to 'false'
     initially.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Example:

          async def waiter(event):
              print('waiting for it ...')
              await event.wait()
              print('... got it!')

          async def main():
              # Create an Event object.
              event = asyncio.Event()

              # Spawn a Task to wait until 'event' is set.
              waiter_task = asyncio.create_task(waiter(event))

              # Sleep for 1 second and set the event.
              await asyncio.sleep(1)
              event.set()

              # Wait until the waiter task is finished.
              await waiter_task

          asyncio.run(main())

      -- Metodo: async wait ()

          Wait until the event is set.

          If the event is set, return ‘True’ immediately.  Otherwise
          block until another task calls *note set(): 3809.

      -- Metodo: set ()

          Set the event.

          All tasks waiting for event to be set will be immediately
          awakened.

      -- Metodo: clear ()

          Clear (unset) the event.

          Subsequent tasks awaiting on *note wait(): 380b. will now
          block until the *note set(): 3809. method is called again.

      -- Metodo: is_set ()

          Return ‘True’ if the event is set.


File: python.info,  Node: Condition,  Next: Semaphore,  Prev: Event,  Up: Synchronization Primitives

5.19.1.33 Condition
...................

 -- Classe: asyncio.Condition (lock=None)

     A Condition object.  Not thread-safe.

     An asyncio condition primitive can be used by a task to wait for
     some event to happen and then get exclusive access to a shared
     resource.

     In essence, a Condition object combines the functionality of an
     *note Event: 2f4. and a *note Lock: c68.  It is possible to have
     multiple Condition objects share one Lock, which allows
     coordinating exclusive access to a shared resource between
     different tasks interested in particular states of that shared
     resource.

     The optional 'lock' argument must be a *note Lock: c68. object or
     ‘None’.  In the latter case a new Lock object is created
     automatically.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     The preferred way to use a Condition is an *note async with: 185.
     statement:

          cond = asyncio.Condition()

          # ... later
          async with cond:
              await cond.wait()

     which is equivalent to:

          cond = asyncio.Condition()

          # ... later
          await cond.acquire()
          try:
              await cond.wait()
          finally:
              cond.release()

      -- Metodo: async acquire ()

          Acquire the underlying lock.

          This method waits until the underlying lock is 'unlocked',
          sets it to 'locked' and returns ‘True’.

      -- Metodo: notify (n=1)

          Wake up 'n' tasks (1 by default) waiting on this condition.
          If fewer than 'n' tasks are waiting they are all awakened.

          The lock must be acquired before this method is called and
          released shortly after.  If called with an 'unlocked' lock a
          *note RuntimeError: 244. error is raised.

      -- Metodo: locked ()

          Return ‘True’ if the underlying lock is acquired.

      -- Metodo: notify_all ()

          Wake up all tasks waiting on this condition.

          This method acts like *note notify(): 19df, but wakes up all
          waiting tasks.

          The lock must be acquired before this method is called and
          released shortly after.  If called with an 'unlocked' lock a
          *note RuntimeError: 244. error is raised.

      -- Metodo: release ()

          Release the underlying lock.

          When invoked on an unlocked lock, a *note RuntimeError: 244.
          is raised.

      -- Metodo: async wait ()

          Wait until notified.

          If the calling task has not acquired the lock when this method
          is called, a *note RuntimeError: 244. is raised.

          This method releases the underlying lock, and then blocks
          until it is awakened by a *note notify(): 19df. or *note
          notify_all(): 3811. call.  Once awakened, the Condition
          re-acquires its lock and this method returns ‘True’.

          Note that a task 'may' return from this call spuriously, which
          is why the caller should always re-check the state and be
          prepared to *note wait(): 1a08. again.  For this reason, you
          may prefer to use *note wait_for(): 3813. instead.

      -- Metodo: async wait_for (predicate)

          Wait until a predicate becomes 'true'.

          The predicate must be a callable which result will be
          interpreted as a boolean value.  The method will repeatedly
          *note wait(): 1a08. until the predicate evaluates to 'true'.
          The final value is the return value.


File: python.info,  Node: Semaphore,  Next: BoundedSemaphore,  Prev: Condition,  Up: Synchronization Primitives

5.19.1.34 Semaphore
...................

 -- Classe: asyncio.Semaphore (value=1)

     A Semaphore object.  Not thread-safe.

     A semaphore manages an internal counter which is decremented by
     each *note acquire(): 1a09. call and incremented by each *note
     release(): 3815. call.  The counter can never go below zero; when
     *note acquire(): 1a09. finds that it is zero, it blocks, waiting
     until some task calls *note release(): 3815.

     The optional 'value' argument gives the initial value for the
     internal counter (‘1’ by default).  If the given value is less than
     ‘0’ a *note ValueError: 2ec. is raised.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     The preferred way to use a Semaphore is an *note async with: 185.
     statement:

          sem = asyncio.Semaphore(10)

          # ... later
          async with sem:
              # work with shared resource

     which is equivalent to:

          sem = asyncio.Semaphore(10)

          # ... later
          await sem.acquire()
          try:
              # work with shared resource
          finally:
              sem.release()

      -- Metodo: async acquire ()

          Acquire a semaphore.

          If the internal counter is greater than zero, decrement it by
          one and return ‘True’ immediately.  If it is zero, wait until
          a *note release(): 3815. is called and return ‘True’.

      -- Metodo: locked ()

          Returns ‘True’ if semaphore can not be acquired immediately.

      -- Metodo: release ()

          Release a semaphore, incrementing the internal counter by one.
          Can wake up a task waiting to acquire the semaphore.

          Unlike *note BoundedSemaphore: c6b, *note Semaphore: c6a.
          allows making more ‘release()’ calls than ‘acquire()’ calls.


File: python.info,  Node: BoundedSemaphore,  Next: Barrier,  Prev: Semaphore,  Up: Synchronization Primitives

5.19.1.35 BoundedSemaphore
..........................

 -- Classe: asyncio.BoundedSemaphore (value=1)

     A bounded semaphore object.  Not thread-safe.

     Bounded Semaphore is a version of *note Semaphore: c6a. that raises
     a *note ValueError: 2ec. in *note release(): 3815. if it increases
     the internal counter above the initial 'value'.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.


File: python.info,  Node: Barrier,  Prev: BoundedSemaphore,  Up: Synchronization Primitives

5.19.1.36 Barrier
.................

 -- Classe: asyncio.Barrier (parties)

     A barrier object.  Not thread-safe.

     A barrier is a simple synchronization primitive that allows to
     block until 'parties' number of tasks are waiting on it.  Tasks can
     wait on the *note wait(): 3819. method and would be blocked until
     the specified number of tasks end up waiting on *note wait(): 3819.
     At that point all of the waiting tasks would unblock
     simultaneously.

     *note async with: 185. can be used as an alternative to awaiting on
     *note wait(): 3819.

     The barrier can be reused any number of times.  Example:

          async def example_barrier():
             # barrier with 3 parties
             b = asyncio.Barrier(3)

             # create 2 new waiting tasks
             asyncio.create_task(b.wait())
             asyncio.create_task(b.wait())

             await asyncio.sleep(0)
             print(b)

             # The third .wait() call passes the barrier
             await b.wait()
             print(b)
             print("barrier passed")

             await asyncio.sleep(0)
             print(b)

          asyncio.run(example_barrier())

     Result of this example is:

          <asyncio.locks.Barrier object at 0x... [filling, waiters:2/3]>
          <asyncio.locks.Barrier object at 0x... [draining, waiters:0/3]>
          barrier passed
          <asyncio.locks.Barrier object at 0x... [filling, waiters:0/3]>

     Added in version 3.11.

      -- Metodo: async wait ()

          Pass the barrier.  When all the tasks party to the barrier
          have called this function, they are all unblocked
          simultaneously.

          When a waiting or blocked task in the barrier is cancelled,
          this task exits the barrier which stays in the same state.  If
          the state of the barrier is «filling», the number of waiting
          task decreases by 1.

          The return value is an integer in the range of 0 to
          ‘parties-1’, different for each task.  This can be used to
          select a task to do some special housekeeping, e.g.:

               ...
               async with barrier as position:
                  if position == 0:
                     # Only one task prints this
                     print('End of *draining phase*')

          This method may raise a *note BrokenBarrierError: 818.
          exception if the barrier is broken or reset while a task is
          waiting.  It could raise a *note CancelledError: 4d5. if a
          task is cancelled.

      -- Metodo: async reset ()

          Return the barrier to the default, empty state.  Any tasks
          waiting on it will receive the *note BrokenBarrierError: 818.
          exception.

          If a barrier is broken it may be better to just leave it and
          create a new one.

      -- Metodo: async abort ()

          Put the barrier into a broken state.  This causes any active
          or future calls to *note wait(): 3819. to fail with the *note
          BrokenBarrierError: 818.  Use this for example if one of the
          tasks needs to abort, to avoid infinite waiting tasks.

      -- Attributo: parties

          The number of tasks required to pass the barrier.

      -- Attributo: n_waiting

          The number of tasks currently waiting in the barrier while
          filling.

      -- Attributo: broken

          A boolean that is ‘True’ if the barrier is in the broken
          state.

 -- Eccezione: asyncio.BrokenBarrierError

     This exception, a subclass of *note RuntimeError: 244, is raised
     when the *note Barrier: 817. object is reset or broken.

__________________________________________________________________

Cambiato nella versione 3.9: Acquiring a lock using ‘await lock’ or
‘yield from lock’ and/or *note with: 186. statement (‘with await lock’,
‘with (yield from lock)’) was removed.  Use ‘async with lock’ instead.


File: python.info,  Node: Subprocesses,  Next: Queues,  Prev: Synchronization Primitives,  Up: asyncio — Asynchronous I/O

5.19.1.37 Subprocesses
......................

'Source code:' Lib/asyncio/subprocess.py(1),
Lib/asyncio/base_subprocess.py(2)

__________________________________________________________________

This section describes high-level async/await asyncio APIs to create and
manage subprocesses.  Here’s an example of how asyncio can run a shell
command and obtain its result:

     import asyncio

     async def run(cmd):
         proc = await asyncio.create_subprocess_shell(
             cmd,
             stdout=asyncio.subprocess.PIPE,
             stderr=asyncio.subprocess.PIPE)

         stdout, stderr = await proc.communicate()

         print(f'[{cmd!r} exited with {proc.returncode}]')
         if stdout:
             print(f'[stdout]\n{stdout.decode()}')
         if stderr:
             print(f'[stderr]\n{stderr.decode()}')

     asyncio.run(run('ls /zzz'))

will print:

     ['ls /zzz' exited with 1]
     [stderr]
     ls: /zzz: No such file or directory

Because all asyncio subprocess functions are asynchronous and asyncio
provides many tools to work with such functions, it is easy to execute
and monitor multiple subprocesses in parallel.  It is indeed trivial to
modify the above example to run several commands simultaneously:

     async def main():
         await asyncio.gather(
             run('ls /zzz'),
             run('sleep 1; echo "hello"'))

     asyncio.run(main())

See also the *note Examples: 3824. subsection.

* Menu:

* Creating Subprocesses::
* Constants: Constants<7>.
* Interacting with Subprocesses::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/subprocess.py

   (2) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/base_subprocess.py


File: python.info,  Node: Creating Subprocesses,  Next: Constants<7>,  Up: Subprocesses

5.19.1.38 Creating Subprocesses
...............................

 -- Funzione: async asyncio.create_subprocess_exec (program, *args,
          stdin=None, stdout=None, stderr=None, limit=None, **kwds)

     Create a subprocess.

     The 'limit' argument sets the buffer limit for *note StreamReader:
     1c65. wrappers for *note stdout: 3826. and *note stderr: 3827. (if
     *note subprocess.PIPE: d82. is passed to 'stdout' and 'stderr'
     arguments).

     Return a *note Process: 3828. instance.

     See the documentation of *note loop.subprocess_exec(): 3829. for
     other parameters.

     If the process object is garbage collected while the process is
     still running, the child process will be killed.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

 -- Funzione: async asyncio.create_subprocess_shell (cmd, stdin=None,
          stdout=None, stderr=None, limit=None, **kwds)

     Run the 'cmd' shell command.

     The 'limit' argument sets the buffer limit for *note StreamReader:
     1c65. wrappers for *note stdout: 3826. and *note stderr: 3827. (if
     *note subprocess.PIPE: d82. is passed to 'stdout' and 'stderr'
     arguments).

     Return a *note Process: 3828. instance.

     See the documentation of *note loop.subprocess_shell(): 382a. for
     other parameters.

     If the process object is garbage collected while the process is
     still running, the child process will be killed.

          Importante: It is the application’s responsibility to ensure
          that all whitespace and special characters are quoted
          appropriately to avoid shell injection(1) vulnerabilities.
          The *note shlex.quote(): 582. function can be used to properly
          escape whitespace and special shell characters in strings that
          are going to be used to construct shell commands.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     Nota: Subprocesses are available for Windows if a *note
     ProactorEventLoop: 81e. is used.  See *note Subprocess Support on
     Windows: 382b. for details.

Vedi anche
..........

asyncio also has the following 'low-level' APIs to work with
subprocesses: *note loop.subprocess_exec(): 3829, *note
loop.subprocess_shell(): 382a, *note loop.connect_read_pipe(): 382c,
*note loop.connect_write_pipe(): 382d, as well as the *note Subprocess
Transports: 382e. and *note Subprocess Protocols: 382f.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Shell_injection#Shell_injection


File: python.info,  Node: Constants<7>,  Next: Interacting with Subprocesses,  Prev: Creating Subprocesses,  Up: Subprocesses

5.19.1.39 Constants
...................

 -- Dati: asyncio.subprocess.PIPE

     Can be passed to the 'stdin', 'stdout' or 'stderr' parameters.

     If 'PIPE' is passed to 'stdin' argument, the *note Process.stdin:
     3832. attribute will point to a *note StreamWriter: 1a58. instance.

     If 'PIPE' is passed to 'stdout' or 'stderr' arguments, the *note
     Process.stdout: 3826. and *note Process.stderr: 3827. attributes
     will point to *note StreamReader: 1c65. instances.

 -- Dati: asyncio.subprocess.STDOUT

     Special value that can be used as the 'stderr' argument and
     indicates that standard error should be redirected into standard
     output.

 -- Dati: asyncio.subprocess.DEVNULL

     Special value that can be used as the 'stdin', 'stdout' or 'stderr'
     argument to process creation functions.  It indicates that the
     special file *note os.devnull: 1dfc. will be used for the
     corresponding subprocess stream.


File: python.info,  Node: Interacting with Subprocesses,  Prev: Constants<7>,  Up: Subprocesses

5.19.1.40 Interacting with Subprocesses
.......................................

Both *note create_subprocess_exec(): c6d. and *note
create_subprocess_shell(): c6e. functions return instances of the
'Process' class.  'Process' is a high-level wrapper that allows
communicating with subprocesses and watching for their completion.

 -- Classe: asyncio.subprocess.Process

     An object that wraps OS processes created by the *note
     create_subprocess_exec(): c6d. and *note create_subprocess_shell():
     c6e. functions.

     This class is designed to have a similar API to the *note
     subprocess.Popen: 4b8. class, but there are some notable
     differences:

        * unlike Popen, Process instances do not have an equivalent to
          the *note poll(): 373f. method;

        * the *note communicate(): 1a87. and *note wait(): 3836. methods
          don’t have a 'timeout' parameter: use the *note wait_for():
          816. function;

        * the *note Process.wait(): 3836. method is asynchronous,
          whereas *note subprocess.Popen.wait(): ee2. method is
          implemented as a blocking busy loop;

        * the 'universal_newlines' parameter is not supported.

     This class is *note not thread safe: 37ce.

     See also the *note Subprocess and Threads: 3837. section.

      -- Metodo: async wait ()

          Wait for the child process to terminate.

          Set and return the *note returncode: 3838. attribute.

               Nota: This method can deadlock when using ‘stdout=PIPE’
               or ‘stderr=PIPE’ and the child process generates so much
               output that it blocks waiting for the OS pipe buffer to
               accept more data.  Use the *note communicate(): 1a87.
               method when using pipes to avoid this condition.

      -- Metodo: async communicate (input=None)

          Interact with process:

            1. send data to 'stdin' (if 'input' is not ‘None’);

            2. closes 'stdin';

            3. read data from 'stdout' and 'stderr', until EOF is
               reached;

            4. wait for process to terminate.

          The optional 'input' argument is the data (*note bytes: 192.
          object) that will be sent to the child process.

          Return a tuple ‘(stdout_data, stderr_data)’.

          If either *note BrokenPipeError: 125e. or *note
          ConnectionResetError: 1261. exception is raised when writing
          'input' into 'stdin', the exception is ignored.  This
          condition occurs when the process exits before all data are
          written into 'stdin'.

          If it is desired to send data to the process” 'stdin', the
          process needs to be created with ‘stdin=PIPE’.  Similarly, to
          get anything other than ‘None’ in the result tuple, the
          process has to be created with ‘stdout=PIPE’ and/or
          ‘stderr=PIPE’ arguments.

          Note, that the data read is buffered in memory, so do not use
          this method if the data size is large or unlimited.

          Cambiato nella versione 3.12: 'stdin' gets closed when
          ‘input=None’ too.

      -- Metodo: send_signal (signal)

          Sends the signal 'signal' to the child process.

               Nota: On Windows, *note SIGTERM: 15e6. is an alias for
               *note terminate(): 3839.  ‘CTRL_C_EVENT’ and
               ‘CTRL_BREAK_EVENT’ can be sent to processes started with
               a 'creationflags' parameter which includes
               ‘CREATE_NEW_PROCESS_GROUP’.

      -- Metodo: terminate ()

          Stop the child process.

          On POSIX systems this method sends *note SIGTERM: 15e6. to the
          child process.

          On Windows the Win32 API function ‘TerminateProcess()’ is
          called to stop the child process.

      -- Metodo: kill ()

          Kill the child process.

          On POSIX systems this method sends *note SIGKILL: d52. to the
          child process.

          On Windows this method is an alias for *note terminate():
          3839.

      -- Attributo: stdin

          Standard input stream (*note StreamWriter: 1a58.) or ‘None’ if
          the process was created with ‘stdin=None’.

      -- Attributo: stdout

          Standard output stream (*note StreamReader: 1c65.) or ‘None’
          if the process was created with ‘stdout=None’.

      -- Attributo: stderr

          Standard error stream (*note StreamReader: 1c65.) or ‘None’ if
          the process was created with ‘stderr=None’.

          Avvertimento: Use the *note communicate(): 1a87. method rather
          than *note process.stdin.write(): 3832, *note await
          process.stdout.read(): 3826. or *note await
          process.stderr.read(): 3827.  This avoids deadlocks due to
          streams pausing reading or writing and blocking the child
          process.

      -- Attributo: pid

          Process identification number (PID).

          Note that for processes created by the *note
          create_subprocess_shell(): c6e. function, this attribute is
          the PID of the spawned shell.

      -- Attributo: returncode

          Return code of the process when it exits.

          A ‘None’ value indicates that the process has not terminated
          yet.

          A negative value ‘-N’ indicates that the child was terminated
          by signal ‘N’ (POSIX only).

* Menu:

* Subprocess and Threads::
* Examples: Examples<17>.


File: python.info,  Node: Subprocess and Threads,  Next: Examples<17>,  Up: Interacting with Subprocesses

5.19.1.41 Subprocess and Threads
................................

Standard asyncio event loop supports running subprocesses from different
threads by default.

On Windows subprocesses are provided by *note ProactorEventLoop: 81e.
only (default), *note SelectorEventLoop: 314. has no subprocess support.

Note that alternative event loop implementations might have own
limitations; please refer to their documentation.

Vedi anche
..........

The *note Concurrency and multithreading in asyncio: 37ce. section.


File: python.info,  Node: Examples<17>,  Prev: Subprocess and Threads,  Up: Interacting with Subprocesses

5.19.1.42 Examples
..................

An example using the *note Process: 3828. class to control a subprocess
and the *note StreamReader: 1c65. class to read from its standard
output.  The subprocess is created by the *note
create_subprocess_exec(): c6d. function:

     import asyncio
     import sys

     async def get_date():
         code = 'import datetime; print(datetime.datetime.now())'

         # Create the subprocess; redirect the standard output
         # into a pipe.
         proc = await asyncio.create_subprocess_exec(
             sys.executable, '-c', code,
             stdout=asyncio.subprocess.PIPE)

         # Read one line of output.
         data = await proc.stdout.readline()
         line = data.decode('ascii').rstrip()

         # Wait for the subprocess exit.
         await proc.wait()
         return line

     date = asyncio.run(get_date())
     print(f"Current date: {date}")

See also the *note same example: 383e. written using low-level APIs.


File: python.info,  Node: Queues,  Next: Exceptions<15>,  Prev: Subprocesses,  Up: asyncio — Asynchronous I/O

5.19.1.43 Queues
................

'Source code:' Lib/asyncio/queues.py(1)

__________________________________________________________________

asyncio queues are designed to be similar to classes of the *note queue:
bb. module.  Although asyncio queues are not thread-safe, they are
designed to be used specifically in async/await code.

Note that methods of asyncio queues don’t have a 'timeout' parameter;
use *note asyncio.wait_for(): 816. function to do queue operations with
a timeout.

See also the *note Examples: 3842. section below.

* Menu:

* Queue::
* Priority Queue::
* LIFO Queue::
* Exceptions: Exceptions<14>.
* Examples: Examples<18>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/asyncio/queues.py


File: python.info,  Node: Queue,  Next: Priority Queue,  Up: Queues

5.19.1.44 Queue
...............

 -- Classe: asyncio.Queue (maxsize=0)

     A first in, first out (FIFO) queue.

     If 'maxsize' is less than or equal to zero, the queue size is
     infinite.  If it is an integer greater than ‘0’, then ‘await put()’
     blocks when the queue reaches 'maxsize' until an item is removed by
     *note get(): 3844.

     Unlike the standard library threading *note queue: bb, the size of
     the queue is always known and can be returned by calling the *note
     qsize(): 3845. method.

     Cambiato nella versione 3.10: Removed the 'loop' parameter.

     This class is *note not thread safe: 37ce.

      -- Attributo: maxsize

          Number of items allowed in the queue.

      -- Metodo: empty ()

          Return ‘True’ if the queue is empty, ‘False’ otherwise.

      -- Metodo: full ()

          Return ‘True’ if there are *note maxsize: 3846. items in the
          queue.

          If the queue was initialized with ‘maxsize=0’ (the default),
          then *note full(): 3848. never returns ‘True’.

      -- Metodo: async get ()

          Remove and return an item from the queue.  If queue is empty,
          wait until an item is available.

          Raises *note QueueShutDown: 4ce. if the queue has been shut
          down and is empty, or if the queue has been shut down
          immediately.

      -- Metodo: get_nowait ()

          Return an item if one is immediately available, else raise
          *note QueueEmpty: 384a.

      -- Metodo: async join ()

          Block until all items in the queue have been received and
          processed.

          The count of unfinished tasks goes up whenever an item is
          added to the queue.  The count goes down whenever a consumer
          coroutine calls *note task_done(): fc9. to indicate that the
          item was retrieved and all work on it is complete.  When the
          count of unfinished tasks drops to zero, *note join(): fc8.
          unblocks.

      -- Metodo: async put (item)

          Put an item into the queue.  If the queue is full, wait until
          a free slot is available before adding the item.

          Raises *note QueueShutDown: 4ce. if the queue has been shut
          down.

      -- Metodo: put_nowait (item)

          Put an item into the queue without blocking.

          If no free slot is immediately available, raise *note
          QueueFull: 384d.

      -- Metodo: qsize ()

          Return the number of items in the queue.

      -- Metodo: shutdown (immediate=False)

          Put a *note Queue: c6c. instance into a shutdown mode.

          The queue can no longer grow.  Future calls to *note put():
          384b. raise *note QueueShutDown: 4ce.  Currently blocked
          callers of *note put(): 384b. will be unblocked and will raise
          *note QueueShutDown: 4ce. in the formerly awaiting task.

          If 'immediate' is false (the default), the queue can be wound
          down normally with *note get(): 3844. calls to extract tasks
          that have already been loaded.

          And if *note task_done(): fc9. is called for each remaining
          task, a pending *note join(): fc8. will be unblocked normally.

          Once the queue is empty, future calls to *note get(): 3844.
          will raise *note QueueShutDown: 4ce.

          If 'immediate' is true, the queue is terminated immediately.
          The queue is drained to be completely empty and the count of
          unfinished tasks is reduced by the number of tasks drained.
          If unfinished tasks is zero, callers of *note join(): fc8. are
          unblocked.  Also, blocked callers of *note get(): 3844. are
          unblocked and will raise *note QueueShutDown: 4ce. because the
          queue is empty.

          Use caution when using *note join(): fc8. with 'immediate' set
          to true.  This unblocks the join even when no work has been
          done on the tasks, violating the usual invariant for joining a
          queue.

          Added in version 3.13.

      -- Metodo: task_done ()

          Indicate that a formerly enqueued work item is complete.

          Used by queue consumers.  For each *note get(): 3844. used to
          fetch a work item, a subsequent call to *note task_done():
          fc9. tells the queue that the processing on the work item is
          complete.

          If a *note join(): fc8. is currently blocking, it will resume
          when all items have been processed (meaning that a *note
          task_done(): fc9. call was received for every item that had
          been *note put(): 384b. into the queue).

          Raises *note ValueError: 2ec. if called more times than there
          were items placed in the queue.


File: python.info,  Node: Priority Queue,  Next: LIFO Queue,  Prev: Queue,  Up: Queues

5.19.1.45 Priority Queue
........................

 -- Classe: asyncio.PriorityQueue

     A variant of *note Queue: c6c.; retrieves entries in priority order
     (lowest first).

     Entries are typically tuples of the form ‘(priority_number, data)’.


File: python.info,  Node: LIFO Queue,  Next: Exceptions<14>,  Prev: Priority Queue,  Up: Queues

5.19.1.46 LIFO Queue
....................

 -- Classe: asyncio.LifoQueue

     A variant of *note Queue: c6c. that retrieves most recently added
     entries first (last in, first out).


File: python.info,  Node: Exceptions<14>,  Next: Examples<18>,  Prev: LIFO Queue,  Up: Queues

5.19.1.47 Exceptions
....................

 -- Eccezione: asyncio.QueueEmpty

     This exception is raised when the *note get_nowait(): 3849. method
     is called on an empty queue.

 -- Eccezione: asyncio.QueueFull

     Exception raised when the *note put_nowait(): 384c. method is
     called on a queue that has reached its 'maxsize'.

 -- Eccezione: asyncio.QueueShutDown

     Exception raised when *note put(): 384b. or *note get(): 3844. is
     called on a queue which has been shut down.

     Added in version 3.13.


File: python.info,  Node: Examples<18>,  Prev: Exceptions<14>,  Up: Queues

5.19.1.48 Examples
..................

Queues can be used to distribute workload between several concurrent
tasks:

     import asyncio
     import random
     import time


     async def worker(name, queue):
         while True:
             # Get a "work item" out of the queue.
             sleep_for = await queue.get()

             # Sleep for the "sleep_for" seconds.
             await asyncio.sleep(sleep_for)

             # Notify the queue that the "work item" has been processed.
             queue.task_done()

             print(f'{name} has slept for {sleep_for:.2f} seconds')


     async def main():
         # Create a queue that we will use to store our "workload".
         queue = asyncio.Queue()

         # Generate random timings and put them into the queue.
         total_sleep_time = 0
         for _ in range(20):
             sleep_for = random.uniform(0.05, 1.0)
             total_sleep_time += sleep_for
             queue.put_nowait(sleep_for)

         # Create three worker tasks to process the queue concurrently.
         tasks = []
         for i in range(3):
             task = asyncio.create_task(worker(f'worker-{i}', queue))
             tasks.append(task)

         # Wait until the queue is fully processed.
         started_at = time.monotonic()
         await queue.join()
         total_slept_for = time.monotonic() - started_at

         # Cancel our worker tasks.
         for task in tasks:
             task.cancel()
         # Wait until all worker tasks are cancelled.
         await asyncio.gather(*tasks, return_exceptions=True)

         print('====')
         print(f'3 workers slept in parallel for {total_slept_for:.2f} seconds')
         print(f'total expected sleep time: {total_sleep_time:.2f} seconds')


     asyncio.run(main())


File: python.info,  Node: Exceptions<15>,  Next: Call Graph Introspection,  Prev: Queues,  Up: asyncio — Asynchronous I/O

5.19.1.49 Exceptions
....................

'Source code:' Lib/asyncio/exceptions.py(1)

__________________________________________________________________

 -- Eccezione: asyncio.TimeoutError

     A deprecated alias of *note TimeoutError: a38, raised when the
     operation has exceeded the given deadline.

     Cambiato nella versione 3.11: This class was made an alias of *note
     TimeoutError: a38.

 -- Eccezione: asyncio.CancelledError

     The operation has been cancelled.

     This exception can be caught to perform custom operations when
     asyncio Tasks are cancelled.  In almost all situations the
     exception must be re-raised.

     Cambiato nella versione 3.8: *note CancelledError: 4d5. is now a
     subclass of *note BaseException: 7d8. rather than *note Exception:
     bcf.

 -- Eccezione: asyncio.InvalidStateError

     Invalid internal state of *note Task: 1c7. or *note Future: dc8.

     Can be raised in situations like setting a result value for a
     'Future' object that already has a result value set.

 -- Eccezione: asyncio.SendfileNotAvailableError

     The «sendfile» syscall is not available for the given socket or
     file type.

     A subclass of *note RuntimeError: 244.

 -- Eccezione: asyncio.IncompleteReadError

     The requested read operation did not complete fully.

     Raised by the *note asyncio stream APIs: 379f.

     This exception is a subclass of *note EOFError: 14e1.

      -- Attributo: expected

          The total number (*note int: 19b.) of expected bytes.

      -- Attributo: partial

          A string of *note bytes: 192. read before the end of stream
          was reached.

 -- Eccezione: asyncio.LimitOverrunError

     Reached the buffer size limit while looking for a separator.

     Raised by the *note asyncio stream APIs: 379f.

      -- Attributo: consumed

          The total number of to be consumed bytes.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/exceptions.py


File: python.info,  Node: Call Graph Introspection,  Next: Event Loop,  Prev: Exceptions<15>,  Up: asyncio — Asynchronous I/O

5.19.1.50 Call Graph Introspection
..................................

'Source code:' Lib/asyncio/graph.py(1)

__________________________________________________________________

asyncio has powerful runtime call graph introspection utilities to trace
the entire call graph of a running 'coroutine' or 'task', or a suspended
'future'.  These utilities and the underlying machinery can be used from
within a Python program or by external profilers and debuggers.

Added in version 3.14.

 -- Funzione: asyncio.print_call_graph (future=None, /, *, file=None,
          depth=1, limit=None)

     Print the async call graph for the current task or the provided
     *note Task: 1c7. or *note Future: dc8.

     This function prints entries starting from the top frame and going
     down towards the invocation point.

     The function receives an optional 'future' argument.  If not
     passed, the current running task will be used.

     If the function is called on 'the current task', the optional
     keyword-only 'depth' argument can be used to skip the specified
     number of frames from top of the stack.

     If the optional keyword-only 'limit' argument is provided, each
     call stack in the resulting graph is truncated to include at most
     ‘abs(limit)’ entries.  If 'limit' is positive, the entries left are
     the closest to the invocation point.  If 'limit' is negative, the
     topmost entries are left.  If 'limit' is omitted or ‘None’, all
     entries are present.  If 'limit' is ‘0’, the call stack is not
     printed at all, only «awaited by» information is printed.

     If 'file' is omitted or ‘None’, the function will print to *note
     sys.stdout: ccf.

     'Example:'

     The following Python code:

          import asyncio

          async def test():
              asyncio.print_call_graph()

          async def main():
              async with asyncio.TaskGroup() as g:
                  g.create_task(test(), name='test')

          asyncio.run(main())

     will print:

          * Task(name='test', id=0x1039f0fe0)
          + Call stack:
          |   File 't2.py', line 4, in async test()
          + Awaited by:
             * Task(name='Task-1', id=0x103a5e060)
                + Call stack:
                |   File 'taskgroups.py', line 107, in async TaskGroup.__aexit__()
                |   File 't2.py', line 7, in async main()

 -- Funzione: asyncio.format_call_graph (future=None, /, *, depth=1,
          limit=None)

     Like *note print_call_graph(): 1cd, but returns a string.  If
     'future' is ‘None’ and there’s no current task, the function
     returns an empty string.

 -- Funzione: asyncio.capture_call_graph (future=None, /, *, depth=1,
          limit=None)

     Capture the async call graph for the current task or the provided
     *note Task: 1c7. or *note Future: dc8.

     The function receives an optional 'future' argument.  If not
     passed, the current running task will be used.  If there’s no
     current task, the function returns ‘None’.

     If the function is called on 'the current task', the optional
     keyword-only 'depth' argument can be used to skip the specified
     number of frames from top of the stack.

     Returns a ‘FutureCallGraph’ data class object:

        * ‘FutureCallGraph(future, call_stack, awaited_by)’

               Where 'future' is a reference to a *note Future: dc8. or
               a *note Task: 1c7. (or their subclasses.)

               ‘call_stack’ is a tuple of ‘FrameCallGraphEntry’ objects.

               ‘awaited_by’ is a tuple of ‘FutureCallGraph’ objects.

        * ‘FrameCallGraphEntry(frame)’

               Where 'frame' is a frame object of a regular Python
               function in the call stack.

* Menu:

* Low level utility functions::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/asyncio/graph.py


File: python.info,  Node: Low level utility functions,  Up: Call Graph Introspection

5.19.1.51 Low level utility functions
.....................................

To introspect an async call graph asyncio requires cooperation from
control flow structures, such as *note shield(): c67. or *note
TaskGroup: 4d2.  Any time an intermediate *note Future: dc8. object with
low-level APIs like *note Future.add_done_callback(): d00. is involved,
the following two functions should be used to inform asyncio about how
exactly such intermediate future objects are connected with the tasks
they wrap or control.

 -- Funzione: asyncio.future_add_to_awaited_by (future, waiter, /)

     Record that 'future' is awaited on by 'waiter'.

     Both 'future' and 'waiter' must be instances of *note Future: dc8.
     or *note Task: 1c7. or their subclasses, otherwise the call would
     have no effect.

     A call to ‘future_add_to_awaited_by()’ must be followed by an
     eventual call to the *note future_discard_from_awaited_by(): 3862.
     function with the same arguments.

 -- Funzione: asyncio.future_discard_from_awaited_by (future, waiter, /)

     Record that 'future' is no longer awaited on by 'waiter'.

     Both 'future' and 'waiter' must be instances of *note Future: dc8.
     or *note Task: 1c7. or their subclasses, otherwise the call would
     have no effect.


File: python.info,  Node: Event Loop,  Next: Futures,  Prev: Call Graph Introspection,  Up: asyncio — Asynchronous I/O

5.19.1.52 Event Loop
....................

'Source code:' Lib/asyncio/events.py(1), Lib/asyncio/base_events.py(2)

__________________________________________________________________

Preface
.......

The event loop is the core of every asyncio application.  Event loops
run asynchronous tasks and callbacks, perform network IO operations, and
run subprocesses.

Application developers should typically use the high-level asyncio
functions, such as *note asyncio.run(): 2f3, and should rarely need to
reference the loop object or call its methods.  This section is intended
mostly for authors of lower-level code, libraries, and frameworks, who
need finer control over the event loop behavior.

Obtaining the Event Loop
........................

The following low-level functions can be used to get, set, or create an
event loop:

 -- Funzione: asyncio.get_running_loop ()

     Return the running event loop in the current OS thread.

     Raise a *note RuntimeError: 244. if there is no running event loop.

     This function can only be called from a coroutine or a callback.

     Added in version 3.7.

 -- Funzione: asyncio.get_event_loop ()

     Get the current event loop.

     When called from a coroutine or a callback (e.g.  scheduled with
     call_soon or similar API), this function will always return the
     running event loop.

     If there is no running event loop set, the function will return the
     result of the ‘get_event_loop_policy().get_event_loop()’ call.

     Because this function has rather complex behavior (especially when
     custom event loop policies are in use), using the *note
     get_running_loop(): d03. function is preferred to *note
     get_event_loop(): 2f2. in coroutines and callbacks.

     As noted above, consider using the higher-level *note
     asyncio.run(): 2f3. function, instead of using these lower level
     functions to manually create and close an event loop.

     Cambiato nella versione 3.14: Raises a *note RuntimeError: 244. if
     there is no current event loop.

          Nota: The ‘asyncio’ policy system is deprecated and will be
          removed in Python 3.16; from there on, this function will
          return the current running event loop if present else it will
          return the loop set by *note set_event_loop(): 1b3d.

 -- Funzione: asyncio.set_event_loop (loop)

     Set 'loop' as the current event loop for the current OS thread.

 -- Funzione: asyncio.new_event_loop ()

     Create and return a new event loop object.

Note that the behaviour of *note get_event_loop(): 2f2, *note
set_event_loop(): 1b3d, and *note new_event_loop(): 37ac. functions can
be altered by *note setting a custom event loop policy: 3866.

Contents
........

This documentation page contains the following sections:

   * The *note Event Loop Methods: 3867. section is the reference
     documentation of the event loop APIs;

   * The *note Callback Handles: 3868. section documents the *note
     Handle: 1e6c. and *note TimerHandle: 1ac5. instances which are
     returned from scheduling methods such as *note loop.call_soon():
     cfc. and *note loop.call_later(): cfe.;

   * The *note Server Objects: 3869. section documents types returned
     from event loop methods like *note loop.create_server(): d0b.;

   * The *note Event Loop Implementations: 386a. section documents the
     *note SelectorEventLoop: 314. and *note ProactorEventLoop: 81e.
     classes;

   * The *note Examples: 386b. section showcases how to work with some
     event loop APIs.

* Menu:

* Event Loop Methods::
* Callback Handles::
* Server Objects::
* Event Loop Implementations::
* Examples: Examples<19>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/asyncio/events.py

   (2) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/base_events.py


File: python.info,  Node: Event Loop Methods,  Next: Callback Handles,  Up: Event Loop

5.19.1.53 Event Loop Methods
............................

Event loops have 'low-level' APIs for the following:

* Menu:

* Running and stopping the loop::
* Scheduling callbacks::
* Scheduling delayed callbacks::
* Creating Futures and Tasks::
* Opening network connections::
* Creating network servers::
* Transferring files::
* TLS Upgrade::
* Watching file descriptors::
* Working with socket objects directly::
* DNS::
* Working with pipes::
* Unix signals::
* Executing code in thread or process pools::
* Error Handling API::
* Enabling debug mode::
* Running Subprocesses::


File: python.info,  Node: Running and stopping the loop,  Next: Scheduling callbacks,  Up: Event Loop Methods

5.19.1.54 Running and stopping the loop
.......................................

 -- Metodo: loop.run_until_complete (future)

     Run until the 'future' (an instance of *note Future: dc8.) has
     completed.

     If the argument is a *note coroutine object: 379e. it is implicitly
     scheduled to run as a *note asyncio.Task: 1c7.

     Return the Future’s result or raise its exception.

 -- Metodo: loop.run_forever ()

     Run the event loop until *note stop(): e79. is called.

     If *note stop(): e79. is called before *note run_forever(): 386e.
     is called, the loop will poll the I/O selector once with a timeout
     of zero, run all callbacks scheduled in response to I/O events (and
     those that were already scheduled), and then exit.

     If *note stop(): e79. is called while *note run_forever(): 386e. is
     running, the loop will run the current batch of callbacks and then
     exit.  Note that new callbacks scheduled by callbacks will not run
     in this case; instead, they will run the next time *note
     run_forever(): 386e. or *note run_until_complete(): e74. is called.

 -- Metodo: loop.stop ()

     Stop the event loop.

 -- Metodo: loop.is_running ()

     Return ‘True’ if the event loop is currently running.

 -- Metodo: loop.is_closed ()

     Return ‘True’ if the event loop was closed.

 -- Metodo: loop.close ()

     Close the event loop.

     The loop must not be running when this function is called.  Any
     pending callbacks will be discarded.

     This method clears all queues and shuts down the executor, but does
     not wait for the executor to finish.

     This method is idempotent and irreversible.  No other methods
     should be called after the event loop is closed.

 -- Metodo: async loop.shutdown_asyncgens ()

     Schedule all currently open *note asynchronous generator: 2476.
     objects to close with an *note aclose(): ad7. call.  After calling
     this method, the event loop will issue a warning if a new
     asynchronous generator is iterated.  This should be used to
     reliably finalize all scheduled asynchronous generators.

     Note that there is no need to call this function when *note
     asyncio.run(): 2f3. is used.

     Example:

          try:
              loop.run_forever()
          finally:
              loop.run_until_complete(loop.shutdown_asyncgens())
              loop.close()

     Added in version 3.6.

 -- Metodo: async loop.shutdown_default_executor (timeout=None)

     Schedule the closure of the default executor and wait for it to
     join all of the threads in the *note ThreadPoolExecutor: 94a.  Once
     this method has been called, using the default executor with *note
     loop.run_in_executor(): ae8. will raise a *note RuntimeError: 244.

     The 'timeout' parameter specifies the amount of time (in *note
     float: 196. seconds) the executor will be given to finish joining.
     With the default, ‘None’, the executor is allowed an unlimited
     amount of time.

     If the 'timeout' is reached, a *note RuntimeWarning: 4d8. is
     emitted and the default executor is terminated without waiting for
     its threads to finish joining.

          Nota: Do not call this method when using *note asyncio.run():
          2f3, as the latter handles default executor shutdown
          automatically.

     Added in version 3.9.

     Cambiato nella versione 3.12: Added the 'timeout' parameter.


File: python.info,  Node: Scheduling callbacks,  Next: Scheduling delayed callbacks,  Prev: Running and stopping the loop,  Up: Event Loop Methods

5.19.1.55 Scheduling callbacks
..............................

 -- Metodo: loop.call_soon (callback, *args, context=None)

     Schedule the 'callback' *note callback: 2d82. to be called with
     'args' arguments at the next iteration of the event loop.

     Return an instance of *note asyncio.Handle: 1e6c, which can be used
     later to cancel the callback.

     Callbacks are called in the order in which they are registered.
     Each callback will be called exactly once.

     The optional keyword-only 'context' argument specifies a custom
     *note contextvars.Context: 177. for the 'callback' to run in.
     Callbacks use the current context when no 'context' is provided.

     Unlike *note call_soon_threadsafe(): cfd, this method is not
     thread-safe.

 -- Metodo: loop.call_soon_threadsafe (callback, *args, context=None)

     A thread-safe variant of *note call_soon(): cfc.  When scheduling
     callbacks from another thread, this function 'must' be used, since
     *note call_soon(): cfc. is not thread-safe.

     This function is safe to be called from a reentrant context or
     signal handler, however, it is not safe or fruitful to use the
     returned handle in such contexts.

     Raises *note RuntimeError: 244. if called on a loop that’s been
     closed.  This can happen on a secondary thread when the main
     application is shutting down.

     See the *note concurrency and multithreading: 37ce. section of the
     documentation.

     Cambiato nella versione 3.7: The 'context' keyword-only parameter
     was added.  See PEP 567(1) for more details.

     Nota: Most *note asyncio: b. scheduling functions don’t allow
     passing keyword arguments.  To do that, use *note
     functools.partial(): 217.:

          # will schedule "print("Hello", flush=True)"
          loop.call_soon(
              functools.partial(print, "Hello", flush=True))

     Using partial objects is usually more convenient than using
     lambdas, as asyncio can render partial objects better in debug and
     error messages.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0567/


File: python.info,  Node: Scheduling delayed callbacks,  Next: Creating Futures and Tasks,  Prev: Scheduling callbacks,  Up: Event Loop Methods

5.19.1.56 Scheduling delayed callbacks
......................................

Event loop provides mechanisms to schedule callback functions to be
called at some point in the future.  Event loop uses monotonic clocks to
track time.

 -- Metodo: loop.call_later (delay, callback, *args, context=None)

     Schedule 'callback' to be called after the given 'delay' number of
     seconds (can be either an int or a float).

     An instance of *note asyncio.TimerHandle: 1ac5. is returned which
     can be used to cancel the callback.

     'callback' will be called exactly once.  If two callbacks are
     scheduled for exactly the same time, the order in which they are
     called is undefined.

     The optional positional 'args' will be passed to the callback when
     it is called.  If you want the callback to be called with keyword
     arguments use *note functools.partial(): 217.

     An optional keyword-only 'context' argument allows specifying a
     custom *note contextvars.Context: 177. for the 'callback' to run
     in.  The current context is used when no 'context' is provided.

          Nota: For performance, callbacks scheduled with *note
          loop.call_later(): cfe. may run up to one clock-resolution
          early (see ‘time.get_clock_info('monotonic').resolution’).

     Cambiato nella versione 3.7: The 'context' keyword-only parameter
     was added.  See PEP 567(1) for more details.

     Cambiato nella versione 3.8: In Python 3.7 and earlier with the
     default event loop implementation, the 'delay' could not exceed one
     day.  This has been fixed in Python 3.8.

 -- Metodo: loop.call_at (when, callback, *args, context=None)

     Schedule 'callback' to be called at the given absolute timestamp
     'when' (an int or a float), using the same time reference as *note
     loop.time(): 3875.

     This method’s behavior is the same as *note call_later(): cfe.

     An instance of *note asyncio.TimerHandle: 1ac5. is returned which
     can be used to cancel the callback.

          Nota: For performance, callbacks scheduled with *note
          loop.call_at(): cff. may run up to one clock-resolution early
          (see ‘time.get_clock_info('monotonic').resolution’).

     Cambiato nella versione 3.7: The 'context' keyword-only parameter
     was added.  See PEP 567(2) for more details.

     Cambiato nella versione 3.8: In Python 3.7 and earlier with the
     default event loop implementation, the difference between 'when'
     and the current time could not exceed one day.  This has been fixed
     in Python 3.8.

 -- Metodo: loop.time ()

     Return the current time, as a *note float: 196. value, according to
     the event loop’s internal monotonic clock.

     Nota: 
     Cambiato nella versione 3.8: In Python 3.7 and earlier timeouts
     (relative 'delay' or absolute 'when') should not exceed one day.
     This has been fixed in Python 3.8.

Vedi anche
..........

The *note asyncio.sleep(): c66. function.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0567/

   (2) https://peps.python.org/pep-0567/


File: python.info,  Node: Creating Futures and Tasks,  Next: Opening network connections,  Prev: Scheduling delayed callbacks,  Up: Event Loop Methods

5.19.1.57 Creating Futures and Tasks
....................................

 -- Metodo: loop.create_future ()

     Create an *note asyncio.Future: dc8. object attached to the event
     loop.

     This is the preferred way to create Futures in asyncio.  This lets
     third-party event loops provide alternative implementations of the
     Future object (with better performance or instrumentation).

     Added in version 3.5.2.

 -- Metodo: loop.create_task (coro, *, name=None, context=None,
          eager_start=None, **kwargs)

     Schedule the execution of *note coroutine: 379e. 'coro'.  Return a
     *note Task: 1c7. object.

     Third-party event loops can use their own subclass of *note Task:
     1c7. for interoperability.  In this case, the result type is a
     subclass of *note Task: 1c7.

     The full function signature is largely the same as that of the
     *note Task: 1c7. constructor (or factory) - all of the keyword
     arguments to this function are passed through to that interface.

     If the 'name' argument is provided and not ‘None’, it is set as the
     name of the task using *note Task.set_name(): bd2.

     An optional keyword-only 'context' argument allows specifying a
     custom *note contextvars.Context: 177. for the 'coro' to run in.
     The current context copy is created when no 'context' is provided.

     An optional keyword-only 'eager_start' argument allows specifying
     if the task should execute eagerly during the call to create_task,
     or be scheduled later.  If 'eager_start' is not passed the mode set
     by *note loop.set_task_factory(): 1c8. will be used.

     Cambiato nella versione 3.8: Added the 'name' parameter.

     Cambiato nella versione 3.11: Added the 'context' parameter.

     Cambiato nella versione 3.13.3: Added ‘kwargs’ which passes on
     arbitrary extra parameters, including ‘name’ and ‘context’.

     Cambiato nella versione 3.13.4: Rolled back the change that passes
     on 'name' and 'context' (if it is None), while still passing on
     other arbitrary keyword arguments (to avoid breaking backwards
     compatibility with 3.13.3).

     Cambiato nella versione 3.14: All 'kwargs' are now passed on.  The
     'eager_start' parameter works with eager task factories.

 -- Metodo: loop.set_task_factory (factory)

     Set a task factory that will be used by *note loop.create_task():
     1ca.

     If 'factory' is ‘None’ the default task factory will be set.
     Otherwise, 'factory' must be a 'callable' with the signature
     matching ‘(loop, coro, **kwargs)’, where 'loop' is a reference to
     the active event loop, and 'coro' is a coroutine object.  The
     callable must pass on all 'kwargs', and return a *note
     asyncio.Task: 1c7.-compatible object.

     Cambiato nella versione 3.13.3: Required that all 'kwargs' are
     passed on to *note asyncio.Task: 1c7.

     Cambiato nella versione 3.13.4: 'name' is no longer passed to task
     factories.  'context' is no longer passed to task factories if it
     is ‘None’.

     Cambiato nella versione 3.14: 'name' and 'context' are now
     unconditionally passed on to task factories again.

 -- Metodo: loop.get_task_factory ()

     Return a task factory or ‘None’ if the default one is in use.


File: python.info,  Node: Opening network connections,  Next: Creating network servers,  Prev: Creating Futures and Tasks,  Up: Event Loop Methods

5.19.1.58 Opening network connections
.....................................

 -- Metodo: async loop.create_connection (protocol_factory, host=None,
          port=None, *, ssl=None, family=0, proto=0, flags=0, sock=None,
          local_addr=None, server_hostname=None,
          ssl_handshake_timeout=None, ssl_shutdown_timeout=None,
          happy_eyeballs_delay=None, interleave=None, all_errors=False)

     Open a streaming transport connection to a given address specified
     by 'host' and 'port'.

     The socket family can be either *note AF_INET: 1b95. or *note
     AF_INET6: 1b96. depending on 'host' (or the 'family' argument, if
     provided).

     The socket type will be *note SOCK_STREAM: 14fb.

     'protocol_factory' must be a callable returning an *note asyncio
     protocol: 3878. implementation.

     This method will try to establish the connection in the background.
     When successful, it returns a ‘(transport, protocol)’ pair.

     The chronological synopsis of the underlying operation is as
     follows:

       1. The connection is established and a *note transport: 3879. is
          created for it.

       2. 'protocol_factory' is called without arguments and is expected
          to return a *note protocol: 3878. instance.

       3. The protocol instance is coupled with the transport by calling
          its *note connection_made(): 387a. method.

       4. A ‘(transport, protocol)’ tuple is returned on success.

     The created transport is an implementation-dependent bidirectional
     stream.

     Other arguments:

        * 'ssl': if given and not false, a SSL/TLS transport is created
          (by default a plain TCP transport is created).  If 'ssl' is a
          *note ssl.SSLContext: 357. object, this context is used to
          create the transport; if 'ssl' is *note True: e09, a default
          context returned from *note ssl.create_default_context(): 480.
          is used.

          Vedi anche
          ..........

          *note SSL/TLS security considerations: 387b.

        * 'server_hostname' sets or overrides the hostname that the
          target server’s certificate will be matched against.  Should
          only be passed if 'ssl' is not ‘None’.  By default the value
          of the 'host' argument is used.  If 'host' is empty, there is
          no default and you must pass a value for 'server_hostname'.
          If 'server_hostname' is an empty string, hostname matching is
          disabled (which is a serious security risk, allowing for
          potential man-in-the-middle attacks).

        * 'family', 'proto', 'flags' are the optional address family,
          protocol and flags to be passed through to getaddrinfo() for
          'host' resolution.  If given, these should all be integers
          from the corresponding *note socket: d1. module constants.

        * 'happy_eyeballs_delay', if given, enables Happy Eyeballs for
          this connection.  It should be a floating-point number
          representing the amount of time in seconds to wait for a
          connection attempt to complete, before starting the next
          attempt in parallel.  This is the «Connection Attempt Delay»
          as defined in RFC 8305(1).  A sensible default value
          recommended by the RFC is ‘0.25’ (250 milliseconds).

        * 'interleave' controls address reordering when a host name
          resolves to multiple IP addresses.  If ‘0’ or unspecified, no
          reordering is done, and addresses are tried in the order
          returned by *note getaddrinfo(): e10.  If a positive integer
          is specified, the addresses are interleaved by address family,
          and the given integer is interpreted as «First Address Family
          Count» as defined in RFC 8305(2).  The default is ‘0’ if
          'happy_eyeballs_delay' is not specified, and ‘1’ if it is.

        * 'sock', if given, should be an existing, already connected
          *note socket.socket: fa3. object to be used by the transport.
          If 'sock' is given, none of 'host', 'port', 'family', 'proto',
          'flags', 'happy_eyeballs_delay', 'interleave' and 'local_addr'
          should be specified.

               Nota: The 'sock' argument transfers ownership of the
               socket to the transport created.  To close the socket,
               call the transport’s *note close(): 387c. method.

        * 'local_addr', if given, is a ‘(local_host, local_port)’ tuple
          used to bind the socket locally.  The 'local_host' and
          'local_port' are looked up using ‘getaddrinfo()’, similarly to
          'host' and 'port'.

        * 'ssl_handshake_timeout' is (for a TLS connection) the time in
          seconds to wait for the TLS handshake to complete before
          aborting the connection.  ‘60.0’ seconds if ‘None’ (default).

        * 'ssl_shutdown_timeout' is the time in seconds to wait for the
          SSL shutdown to complete before aborting the connection.
          ‘30.0’ seconds if ‘None’ (default).

        * 'all_errors' determines what exceptions are raised when a
          connection cannot be created.  By default, only a single
          ‘Exception’ is raised: the first exception if there is only
          one or all errors have same message, or a single ‘OSError’
          with the error messages combined.  When ‘all_errors’ is
          ‘True’, an ‘ExceptionGroup’ will be raised containing all
          exceptions (even if there is only one).

     Cambiato nella versione 3.5: Added support for SSL/TLS in *note
     ProactorEventLoop: 81e.

     Cambiato nella versione 3.6: The socket option *note
     socket.TCP_NODELAY: d6e. is set by default for all TCP connections.

     Cambiato nella versione 3.7: Added the 'ssl_handshake_timeout'
     parameter.

     Cambiato nella versione 3.8: Added the 'happy_eyeballs_delay' and
     'interleave' parameters.

     Happy Eyeballs Algorithm: Success with Dual-Stack Hosts.  When a
     server’s IPv4 path and protocol are working, but the server’s IPv6
     path and protocol are not working, a dual-stack client application
     experiences significant connection delay compared to an IPv4-only
     client.  This is undesirable because it causes the dual-stack
     client to have a worse user experience.  This document specifies
     requirements for algorithms that reduce this user-visible delay and
     provides an algorithm.

     For more information:
     ‘https://datatracker.ietf.org/doc/html/rfc6555’

     Cambiato nella versione 3.11: Added the 'ssl_shutdown_timeout'
     parameter.

     Cambiato nella versione 3.12: 'all_errors' was added.

     Vedi anche
     ..........

     The *note open_connection(): d10. function is a high-level
     alternative API. It returns a pair of (*note StreamReader: 1c65,
     *note StreamWriter: 1a58.) that can be used directly in async/await
     code.

 -- Metodo: async loop.create_datagram_endpoint (protocol_factory,
          local_addr=None, remote_addr=None, *, family=0, proto=0,
          flags=0, reuse_port=None, allow_broadcast=None, sock=None)

     Create a datagram connection.

     The socket family can be either *note AF_INET: 1b95, *note
     AF_INET6: 1b96, or *note AF_UNIX: 1b98, depending on 'host' (or the
     'family' argument, if provided).

     The socket type will be *note SOCK_DGRAM: 14fa.

     'protocol_factory' must be a callable returning a *note protocol:
     3878. implementation.

     A tuple of ‘(transport, protocol)’ is returned on success.

     Other arguments:

        * 'local_addr', if given, is a ‘(local_host, local_port)’ tuple
          used to bind the socket locally.  The 'local_host' and
          'local_port' are looked up using *note getaddrinfo(): e10.

               Nota: On Windows, when using the proactor event loop with
               ‘local_addr=None’, an *note OSError: 2c0. with
               ‘errno.WSAEINVAL’ will be raised when running it.

        * 'remote_addr', if given, is a ‘(remote_host, remote_port)’
          tuple used to connect the socket to a remote address.  The
          'remote_host' and 'remote_port' are looked up using *note
          getaddrinfo(): e10.

        * 'family', 'proto', 'flags' are the optional address family,
          protocol and flags to be passed through to *note
          getaddrinfo(): e10. for 'host' resolution.  If given, these
          should all be integers from the corresponding *note socket:
          d1. module constants.

        * 'reuse_port' tells the kernel to allow this endpoint to be
          bound to the same port as other existing endpoints are bound
          to, so long as they all set this flag when being created.
          This option is not supported on Windows and some Unixes.  If
          the *note socket.SO_REUSEPORT: d6e. constant is not defined
          then this capability is unsupported.

        * 'allow_broadcast' tells the kernel to allow this endpoint to
          send messages to the broadcast address.

        * 'sock' can optionally be specified in order to use a
          preexisting, already connected, *note socket.socket: fa3.
          object to be used by the transport.  If specified,
          'local_addr' and 'remote_addr' should be omitted (must be
          *note None: 886.).

               Nota: The 'sock' argument transfers ownership of the
               socket to the transport created.  To close the socket,
               call the transport’s *note close(): 387c. method.

     See *note UDP echo client protocol: 387d. and *note UDP echo server
     protocol: 387e. examples.

     Cambiato nella versione 3.4.4: The 'family', 'proto', 'flags',
     'reuse_address', 'reuse_port', 'allow_broadcast', and 'sock'
     parameters were added.

     Cambiato nella versione 3.8: Added support for Windows.

     Cambiato nella versione 3.8.1: The 'reuse_address' parameter is no
     longer supported, as using *note socket.SO_REUSEADDR: d6e. poses a
     significant security concern for UDP. Explicitly passing
     ‘reuse_address=True’ will raise an exception.

     When multiple processes with differing UIDs assign sockets to an
     identical UDP socket address with ‘SO_REUSEADDR’, incoming packets
     can become randomly distributed among the sockets.

     For supported platforms, 'reuse_port' can be used as a replacement
     for similar functionality.  With 'reuse_port', *note
     socket.SO_REUSEPORT: d6e. is used instead, which specifically
     prevents processes with differing UIDs from assigning sockets to
     the same socket address.

     Cambiato nella versione 3.11: The 'reuse_address' parameter,
     disabled since Python 3.8.1, 3.7.6 and 3.6.10, has been entirely
     removed.

 -- Metodo: async loop.create_unix_connection (protocol_factory,
          path=None, *, ssl=None, sock=None, server_hostname=None,
          ssl_handshake_timeout=None, ssl_shutdown_timeout=None)

     Create a Unix connection.

     The socket family will be *note AF_UNIX: 1b98.; socket type will be
     *note SOCK_STREAM: 14fb.

     A tuple of ‘(transport, protocol)’ is returned on success.

     'path' is the name of a Unix domain socket and is required, unless
     a 'sock' parameter is specified.  Abstract Unix sockets, *note str:
     169, *note bytes: 192, and *note Path: 266. paths are supported.

     See the documentation of the *note loop.create_connection(): 819.
     method for information about arguments to this method.

     *note Availability: 2128.: Unix.

     Cambiato nella versione 3.7: Added the 'ssl_handshake_timeout'
     parameter.  The 'path' parameter can now be a *note path-like
     object: 5a1.

     Cambiato nella versione 3.11: Added the 'ssl_shutdown_timeout'
     parameter.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc8305.html

   (2) https://datatracker.ietf.org/doc/html/rfc8305.html


File: python.info,  Node: Creating network servers,  Next: Transferring files,  Prev: Opening network connections,  Up: Event Loop Methods

5.19.1.59 Creating network servers
..................................

 -- Metodo: async loop.create_server (protocol_factory, host=None,
          port=None, *, family=socket.AF_UNSPEC,
          flags=socket.AI_PASSIVE, sock=None, backlog=100, ssl=None,
          reuse_address=None, reuse_port=None, keep_alive=None,
          ssl_handshake_timeout=None, ssl_shutdown_timeout=None,
          start_serving=True)

     Create a TCP server (socket type *note SOCK_STREAM: 14fb.)
     listening on 'port' of the 'host' address.

     Returns a *note Server: d0a. object.

     Arguments:

        * 'protocol_factory' must be a callable returning a *note
          protocol: 3878. implementation.

        * The 'host' parameter can be set to several types which
          determine where the server would be listening:

             - If 'host' is a string, the TCP server is bound to a
               single network interface specified by 'host'.

             - If 'host' is a sequence of strings, the TCP server is
               bound to all network interfaces specified by the
               sequence.

             - If 'host' is an empty string or ‘None’, all interfaces
               are assumed and a list of multiple sockets will be
               returned (most likely one for IPv4 and another one for
               IPv6).

        * The 'port' parameter can be set to specify which port the
          server should listen on.  If ‘0’ or ‘None’ (the default), a
          random unused port will be selected (note that if 'host'
          resolves to multiple network interfaces, a different random
          port will be selected for each interface).

        * 'family' can be set to either *note socket.AF_INET: 1b95. or
          *note AF_INET6: 1b96. to force the socket to use IPv4 or IPv6.
          If not set, the 'family' will be determined from host name
          (defaults to *note AF_UNSPEC: 3880.).

        * 'flags' is a bitmask for *note getaddrinfo(): e10.

        * 'sock' can optionally be specified in order to use a
          preexisting socket object.  If specified, 'host' and 'port'
          must not be specified.

               Nota: The 'sock' argument transfers ownership of the
               socket to the server created.  To close the socket, call
               the server’s *note close(): 37e3. method.

        * 'backlog' is the maximum number of queued connections passed
          to *note listen(): 1060. (defaults to 100).

        * 'ssl' can be set to an *note SSLContext: 357. instance to
          enable TLS over the accepted connections.

        * 'reuse_address' tells the kernel to reuse a local socket in
          ‘TIME_WAIT’ state, without waiting for its natural timeout to
          expire.  If not specified will automatically be set to ‘True’
          on Unix.

        * 'reuse_port' tells the kernel to allow this endpoint to be
          bound to the same port as other existing endpoints are bound
          to, so long as they all set this flag when being created.
          This option is not supported on Windows.

        * 'keep_alive' set to ‘True’ keeps connections active by
          enabling the periodic transmission of messages.

     Cambiato nella versione 3.13: Added the 'keep_alive' parameter.

        * 'ssl_handshake_timeout' is (for a TLS server) the time in
          seconds to wait for the TLS handshake to complete before
          aborting the connection.  ‘60.0’ seconds if ‘None’ (default).

        * 'ssl_shutdown_timeout' is the time in seconds to wait for the
          SSL shutdown to complete before aborting the connection.
          ‘30.0’ seconds if ‘None’ (default).

        * 'start_serving' set to ‘True’ (the default) causes the created
          server to start accepting connections immediately.  When set
          to ‘False’, the user should await on *note
          Server.start_serving(): d0c. or *note Server.serve_forever():
          d0d. to make the server to start accepting connections.

     Cambiato nella versione 3.5: Added support for SSL/TLS in *note
     ProactorEventLoop: 81e.

     Cambiato nella versione 3.5.1: The 'host' parameter can be a
     sequence of strings.

     Cambiato nella versione 3.6: Added 'ssl_handshake_timeout' and
     'start_serving' parameters.  The socket option *note
     socket.TCP_NODELAY: d6e. is set by default for all TCP connections.

     Cambiato nella versione 3.11: Added the 'ssl_shutdown_timeout'
     parameter.

     Vedi anche
     ..........

     The *note start_server(): d11. function is a higher-level
     alternative API that returns a pair of *note StreamReader: 1c65.
     and *note StreamWriter: 1a58. that can be used in an async/await
     code.

 -- Metodo: async loop.create_unix_server (protocol_factory, path=None,
          *, sock=None, backlog=100, ssl=None,
          ssl_handshake_timeout=None, ssl_shutdown_timeout=None,
          start_serving=True, cleanup_socket=True)

     Similar to *note loop.create_server(): d0b. but works with the
     *note AF_UNIX: 1b98. socket family.

     'path' is the name of a Unix domain socket, and is required, unless
     a 'sock' argument is provided.  Abstract Unix sockets, *note str:
     169, *note bytes: 192, and *note Path: 266. paths are supported.

     If 'cleanup_socket' is true then the Unix socket will automatically
     be removed from the filesystem when the server is closed, unless
     the socket has been replaced after the server has been created.

     See the documentation of the *note loop.create_server(): d0b.
     method for information about arguments to this method.

     *note Availability: 2128.: Unix.

     Cambiato nella versione 3.7: Added the 'ssl_handshake_timeout' and
     'start_serving' parameters.  The 'path' parameter can now be a
     *note Path: 266. object.

     Cambiato nella versione 3.11: Added the 'ssl_shutdown_timeout'
     parameter.

     Cambiato nella versione 3.13: Added the 'cleanup_socket' parameter.

 -- Metodo: async loop.connect_accepted_socket (protocol_factory, sock,
          *, ssl=None, ssl_handshake_timeout=None,
          ssl_shutdown_timeout=None)

     Wrap an already accepted connection into a transport/protocol pair.

     This method can be used by servers that accept connections outside
     of asyncio but that use asyncio to handle them.

     Parameters:

        * 'protocol_factory' must be a callable returning a *note
          protocol: 3878. implementation.

        * 'sock' is a preexisting socket object returned from *note
          socket.accept: fa4.

               Nota: The 'sock' argument transfers ownership of the
               socket to the transport created.  To close the socket,
               call the transport’s *note close(): 387c. method.

        * 'ssl' can be set to an *note SSLContext: 357. to enable SSL
          over the accepted connections.

        * 'ssl_handshake_timeout' is (for an SSL connection) the time in
          seconds to wait for the SSL handshake to complete before
          aborting the connection.  ‘60.0’ seconds if ‘None’ (default).

        * 'ssl_shutdown_timeout' is the time in seconds to wait for the
          SSL shutdown to complete before aborting the connection.
          ‘30.0’ seconds if ‘None’ (default).

     Returns a ‘(transport, protocol)’ pair.

     Added in version 3.5.3.

     Cambiato nella versione 3.7: Added the 'ssl_handshake_timeout'
     parameter.

     Cambiato nella versione 3.11: Added the 'ssl_shutdown_timeout'
     parameter.


File: python.info,  Node: Transferring files,  Next: TLS Upgrade,  Prev: Creating network servers,  Up: Event Loop Methods

5.19.1.60 Transferring files
............................

 -- Metodo: async loop.sendfile (transport, file, offset=0, count=None,
          *, fallback=True)

     Send a 'file' over a 'transport'.  Return the total number of bytes
     sent.

     The method uses high-performance *note os.sendfile(): d07. if
     available.

     'file' must be a regular file object opened in binary mode.

     'offset' tells from where to start reading the file.  If specified,
     'count' is the total number of bytes to transmit as opposed to
     sending the file until EOF is reached.  File position is always
     updated, even when this method raises an error, and *note
     file.tell(): 15b4. can be used to obtain the actual number of bytes
     sent.

     'fallback' set to ‘True’ makes asyncio to manually read and send
     the file when the platform does not support the sendfile system
     call (e.g.  Windows or SSL socket on Unix).

     Raise *note SendfileNotAvailableError: 3858. if the system does not
     support the 'sendfile' syscall and 'fallback' is ‘False’.

     Added in version 3.7.


File: python.info,  Node: TLS Upgrade,  Next: Watching file descriptors,  Prev: Transferring files,  Up: Event Loop Methods

5.19.1.61 TLS Upgrade
.....................

 -- Metodo: async loop.start_tls (transport, protocol, sslcontext, *,
          server_side=False, server_hostname=None,
          ssl_handshake_timeout=None, ssl_shutdown_timeout=None)

     Upgrade an existing transport-based connection to TLS.

     Create a TLS coder/decoder instance and insert it between the
     'transport' and the 'protocol'.  The coder/decoder implements both
     'transport'-facing protocol and 'protocol'-facing transport.

     Return the created two-interface instance.  After 'await', the
     'protocol' must stop using the original 'transport' and communicate
     with the returned object only because the coder caches
     'protocol'-side data and sporadically exchanges extra TLS session
     packets with 'transport'.

     In some situations (e.g.  when the passed transport is already
     closing) this may return ‘None’.

     Parameters:

        * 'transport' and 'protocol' instances that methods like *note
          create_server(): d0b. and *note create_connection(): 819.
          return.

        * 'sslcontext': a configured instance of *note SSLContext: 357.

        * 'server_side' pass ‘True’ when a server-side connection is
          being upgraded (like the one created by *note create_server():
          d0b.).

        * 'server_hostname': sets or overrides the host name that the
          target server’s certificate will be matched against.

        * 'ssl_handshake_timeout' is (for a TLS connection) the time in
          seconds to wait for the TLS handshake to complete before
          aborting the connection.  ‘60.0’ seconds if ‘None’ (default).

        * 'ssl_shutdown_timeout' is the time in seconds to wait for the
          SSL shutdown to complete before aborting the connection.
          ‘30.0’ seconds if ‘None’ (default).

     Added in version 3.7.

     Cambiato nella versione 3.11: Added the 'ssl_shutdown_timeout'
     parameter.


File: python.info,  Node: Watching file descriptors,  Next: Working with socket objects directly,  Prev: TLS Upgrade,  Up: Event Loop Methods

5.19.1.62 Watching file descriptors
...................................

 -- Metodo: loop.add_reader (fd, callback, *args)

     Start monitoring the 'fd' file descriptor for read availability and
     invoke 'callback' with the specified arguments once 'fd' is
     available for reading.

     Any preexisting callback registered for 'fd' is cancelled and
     replaced by 'callback'.

 -- Metodo: loop.remove_reader (fd)

     Stop monitoring the 'fd' file descriptor for read availability.
     Returns ‘True’ if 'fd' was previously being monitored for reads.

 -- Metodo: loop.add_writer (fd, callback, *args)

     Start monitoring the 'fd' file descriptor for write availability
     and invoke 'callback' with the specified arguments once 'fd' is
     available for writing.

     Any preexisting callback registered for 'fd' is cancelled and
     replaced by 'callback'.

     Use *note functools.partial(): 217. *note to pass keyword
     arguments: 3872. to 'callback'.

 -- Metodo: loop.remove_writer (fd)

     Stop monitoring the 'fd' file descriptor for write availability.
     Returns ‘True’ if 'fd' was previously being monitored for writes.

See also *note Platform Support: 3888. section for some limitations of
these methods.


File: python.info,  Node: Working with socket objects directly,  Next: DNS,  Prev: Watching file descriptors,  Up: Event Loop Methods

5.19.1.63 Working with socket objects directly
..............................................

In general, protocol implementations that use transport-based APIs such
as *note loop.create_connection(): 819. and *note loop.create_server():
d0b. are faster than implementations that work with sockets directly.
However, there are some use cases when performance is not critical, and
working with *note socket: fa3. objects directly is more convenient.

 -- Metodo: async loop.sock_recv (sock, nbytes)

     Receive up to 'nbytes' from 'sock'.  Asynchronous version of *note
     socket.recv(): fa6.

     Return the received data as a bytes object.

     'sock' must be a non-blocking socket.

     Cambiato nella versione 3.7: Even though this method was always
     documented as a coroutine method, releases before Python 3.7
     returned a *note Future: dc8.  Since Python 3.7 this is an ‘async
     def’ method.

 -- Metodo: async loop.sock_recv_into (sock, buf)

     Receive data from 'sock' into the 'buf' buffer.  Modeled after the
     blocking *note socket.recv_into(): 1525. method.

     Return the number of bytes written to the buffer.

     'sock' must be a non-blocking socket.

     Added in version 3.7.

 -- Metodo: async loop.sock_recvfrom (sock, bufsize)

     Receive a datagram of up to 'bufsize' from 'sock'.  Asynchronous
     version of *note socket.recvfrom(): fa7.

     Return a tuple of (received data, remote address).

     'sock' must be a non-blocking socket.

     Added in version 3.11.

 -- Metodo: async loop.sock_recvfrom_into (sock, buf, nbytes=0)

     Receive a datagram of up to 'nbytes' from 'sock' into 'buf'.
     Asynchronous version of *note socket.recvfrom_into(): 1526.

     Return a tuple of (number of bytes received, remote address).

     'sock' must be a non-blocking socket.

     Added in version 3.11.

 -- Metodo: async loop.sock_sendall (sock, data)

     Send 'data' to the 'sock' socket.  Asynchronous version of *note
     socket.sendall(): faa.

     This method continues to send to the socket until either all data
     in 'data' has been sent or an error occurs.  ‘None’ is returned on
     success.  On error, an exception is raised.  Additionally, there is
     no way to determine how much data, if any, was successfully
     processed by the receiving end of the connection.

     'sock' must be a non-blocking socket.

     Cambiato nella versione 3.7: Even though the method was always
     documented as a coroutine method, before Python 3.7 it returned a
     *note Future: dc8.  Since Python 3.7, this is an ‘async def’
     method.

 -- Metodo: async loop.sock_sendto (sock, data, address)

     Send a datagram from 'sock' to 'address'.  Asynchronous version of
     *note socket.sendto(): fab.

     Return the number of bytes sent.

     'sock' must be a non-blocking socket.

     Added in version 3.11.

 -- Metodo: async loop.sock_connect (sock, address)

     Connect 'sock' to a remote socket at 'address'.

     Asynchronous version of *note socket.connect(): fa5.

     'sock' must be a non-blocking socket.

     Cambiato nella versione 3.5.2: ‘address’ no longer needs to be
     resolved.  ‘sock_connect’ will try to check if the 'address' is
     already resolved by calling *note socket.inet_pton(): b5d.  If not,
     *note loop.getaddrinfo(): e10. will be used to resolve the
     'address'.

     Vedi anche
     ..........

     *note loop.create_connection(): 819. and *note
     asyncio.open_connection(): d10.

 -- Metodo: async loop.sock_accept (sock)

     Accept a connection.  Modeled after the blocking *note
     socket.accept(): fa4. method.

     The socket must be bound to an address and listening for
     connections.  The return value is a pair ‘(conn, address)’ where
     'conn' is a 'new' socket object usable to send and receive data on
     the connection, and 'address' is the address bound to the socket on
     the other end of the connection.

     'sock' must be a non-blocking socket.

     Cambiato nella versione 3.7: Even though the method was always
     documented as a coroutine method, before Python 3.7 it returned a
     *note Future: dc8.  Since Python 3.7, this is an ‘async def’
     method.

     Vedi anche
     ..........

     *note loop.create_server(): d0b. and *note start_server(): d11.

 -- Metodo: async loop.sock_sendfile (sock, file, offset=0, count=None,
          *, fallback=True)

     Send a file using high-performance *note os.sendfile: d07. if
     possible.  Return the total number of bytes sent.

     Asynchronous version of *note socket.sendfile(): 105f.

     'sock' must be a non-blocking *note socket.SOCK_STREAM: 14fb. *note
     socket: fa3.

     'file' must be a regular file object open in binary mode.

     'offset' tells from where to start reading the file.  If specified,
     'count' is the total number of bytes to transmit as opposed to
     sending the file until EOF is reached.  File position is always
     updated, even when this method raises an error, and *note
     file.tell(): 15b4. can be used to obtain the actual number of bytes
     sent.

     'fallback', when set to ‘True’, makes asyncio manually read and
     send the file when the platform does not support the sendfile
     syscall (e.g.  Windows or SSL socket on Unix).

     Raise *note SendfileNotAvailableError: 3858. if the system does not
     support 'sendfile' syscall and 'fallback' is ‘False’.

     'sock' must be a non-blocking socket.

     Added in version 3.7.


File: python.info,  Node: DNS,  Next: Working with pipes,  Prev: Working with socket objects directly,  Up: Event Loop Methods

5.19.1.64 DNS
.............

 -- Metodo: async loop.getaddrinfo (host, port, *, family=0, type=0,
          proto=0, flags=0)

     Asynchronous version of *note socket.getaddrinfo(): 1aab.

 -- Metodo: async loop.getnameinfo (sockaddr, flags=0)

     Asynchronous version of *note socket.getnameinfo(): 1a22.

     Nota: Both 'getaddrinfo' and 'getnameinfo' internally utilize their
     synchronous versions through the loop’s default thread pool
     executor.  When this executor is saturated, these methods may
     experience delays, which higher-level networking libraries may
     report as increased timeouts.  To mitigate this, consider using a
     custom executor for other user tasks, or setting a default executor
     with a larger number of workers.

Cambiato nella versione 3.7: Both 'getaddrinfo' and 'getnameinfo'
methods were always documented to return a coroutine, but prior to
Python 3.7 they were, in fact, returning *note asyncio.Future: dc8.
objects.  Starting with Python 3.7 both methods are coroutines.


File: python.info,  Node: Working with pipes,  Next: Unix signals,  Prev: DNS,  Up: Event Loop Methods

5.19.1.65 Working with pipes
............................

 -- Metodo: async loop.connect_read_pipe (protocol_factory, pipe)

     Register the read end of 'pipe' in the event loop.

     'protocol_factory' must be a callable returning an *note asyncio
     protocol: 3878. implementation.

     'pipe' is a *note file-like object: 13cb.

     Return pair ‘(transport, protocol)’, where 'transport' supports the
     *note ReadTransport: 388c. interface and 'protocol' is an object
     instantiated by the 'protocol_factory'.

     With *note SelectorEventLoop: 314. event loop, the 'pipe' is set to
     non-blocking mode.

 -- Metodo: async loop.connect_write_pipe (protocol_factory, pipe)

     Register the write end of 'pipe' in the event loop.

     'protocol_factory' must be a callable returning an *note asyncio
     protocol: 3878. implementation.

     'pipe' is *note file-like object: 13cb.

     Return pair ‘(transport, protocol)’, where 'transport' supports
     *note WriteTransport: 388d. interface and 'protocol' is an object
     instantiated by the 'protocol_factory'.

     With *note SelectorEventLoop: 314. event loop, the 'pipe' is set to
     non-blocking mode.

     Nota: *note SelectorEventLoop: 314. does not support the above
     methods on Windows.  Use *note ProactorEventLoop: 81e. instead for
     Windows.

Vedi anche
..........

The *note loop.subprocess_exec(): 3829. and *note
loop.subprocess_shell(): 382a. methods.


File: python.info,  Node: Unix signals,  Next: Executing code in thread or process pools,  Prev: Working with pipes,  Up: Event Loop Methods

5.19.1.66 Unix signals
......................

 -- Metodo: loop.add_signal_handler (signum, callback, *args)

     Set 'callback' as the handler for the 'signum' signal.

     The callback will be invoked by 'loop', along with other queued
     callbacks and runnable coroutines of that event loop.  Unlike
     signal handlers registered using *note signal.signal(): 133c, a
     callback registered with this function is allowed to interact with
     the event loop.

     Raise *note ValueError: 2ec. if the signal number is invalid or
     uncatchable.  Raise *note RuntimeError: 244. if there is a problem
     setting up the handler.

     Use *note functools.partial(): 217. *note to pass keyword
     arguments: 3872. to 'callback'.

     Like *note signal.signal(): 133c, this function must be invoked in
     the main thread.

 -- Metodo: loop.remove_signal_handler (sig)

     Remove the handler for the 'sig' signal.

     Return ‘True’ if the signal handler was removed, or ‘False’ if no
     handler was set for the given signal.

     *note Availability: 2128.: Unix.

Vedi anche
..........

The *note signal: cb. module.


File: python.info,  Node: Executing code in thread or process pools,  Next: Error Handling API,  Prev: Unix signals,  Up: Event Loop Methods

5.19.1.67 Executing code in thread or process pools
...................................................

 -- Metodo: awaitable loop.run_in_executor (executor, func, *args)

     Arrange for 'func' to be called in the specified executor.

     The 'executor' argument should be an *note
     concurrent.futures.Executor: 36c8. instance.  The default executor
     is used if 'executor' is ‘None’.  The default executor can be set
     by *note loop.set_default_executor(): 94b, otherwise, a *note
     concurrent.futures.ThreadPoolExecutor: 94a. will be
     lazy-initialized and used by *note run_in_executor(): ae8. if
     needed.

     Example:

          import asyncio
          import concurrent.futures

          def blocking_io():
              # File operations (such as logging) can block the
              # event loop: run them in a thread pool.
              with open('/dev/urandom', 'rb') as f:
                  return f.read(100)

          def cpu_bound():
              # CPU-bound operations will block the event loop:
              # in general it is preferable to run them in a
              # process pool.
              return sum(i * i for i in range(10 ** 7))

          async def main():
              loop = asyncio.get_running_loop()

              ## Options:

              # 1. Run in the default loop's executor:
              result = await loop.run_in_executor(
                  None, blocking_io)
              print('default thread pool', result)

              # 2. Run in a custom thread pool:
              with concurrent.futures.ThreadPoolExecutor() as pool:
                  result = await loop.run_in_executor(
                      pool, blocking_io)
                  print('custom thread pool', result)

              # 3. Run in a custom process pool:
              with concurrent.futures.ProcessPoolExecutor() as pool:
                  result = await loop.run_in_executor(
                      pool, cpu_bound)
                  print('custom process pool', result)

              # 4. Run in a custom interpreter pool:
              with concurrent.futures.InterpreterPoolExecutor() as pool:
                  result = await loop.run_in_executor(
                      pool, cpu_bound)
                  print('custom interpreter pool', result)

          if __name__ == '__main__':
              asyncio.run(main())

     Note that the entry point guard (‘if __name__ == '__main__'’) is
     required for option 3 due to the peculiarities of *note
     multiprocessing: 98, which is used by *note ProcessPoolExecutor:
     1d6.  See *note Safe importing of main module: 36b1.

     This method returns a *note asyncio.Future: dc8. object.

     Use *note functools.partial(): 217. *note to pass keyword
     arguments: 3872. to 'func'.

     Cambiato nella versione 3.5.3: *note loop.run_in_executor(): ae8.
     no longer configures the ‘max_workers’ of the thread pool executor
     it creates, instead leaving it up to the thread pool executor
     (*note ThreadPoolExecutor: 94a.) to set the default.

 -- Metodo: loop.set_default_executor (executor)

     Set 'executor' as the default executor used by *note
     run_in_executor(): ae8.  'executor' must be an instance of *note
     ThreadPoolExecutor: 94a, which includes *note
     InterpreterPoolExecutor: 1d2.

     Cambiato nella versione 3.11: 'executor' must be an instance of
     *note ThreadPoolExecutor: 94a.


File: python.info,  Node: Error Handling API,  Next: Enabling debug mode,  Prev: Executing code in thread or process pools,  Up: Event Loop Methods

5.19.1.68 Error Handling API
............................

Allows customizing how exceptions are handled in the event loop.

 -- Metodo: loop.set_exception_handler (handler)

     Set 'handler' as the new event loop exception handler.

     If 'handler' is ‘None’, the default exception handler will be set.
     Otherwise, 'handler' must be a callable with the signature matching
     ‘(loop, context)’, where ‘loop’ is a reference to the active event
     loop, and ‘context’ is a ‘dict’ object containing the details of
     the exception (see *note call_exception_handler(): 3894.
     documentation for details about context).

     If the handler is called on behalf of a *note Task: 1c7. or *note
     Handle: 1e6c, it is run in the *note contextvars.Context: 177. of
     that task or callback handle.

     Cambiato nella versione 3.12: The handler may be called in the
     *note Context: 177. of the task or handle where the exception
     originated.

 -- Metodo: loop.get_exception_handler ()

     Return the current exception handler, or ‘None’ if no custom
     exception handler was set.

     Added in version 3.5.2.

 -- Metodo: loop.default_exception_handler (context)

     Default exception handler.

     This is called when an exception occurs and no exception handler is
     set.  This can be called by a custom exception handler that wants
     to defer to the default handler behavior.

     'context' parameter has the same meaning as in *note
     call_exception_handler(): 3894.

 -- Metodo: loop.call_exception_handler (context)

     Call the current event loop exception handler.

     'context' is a ‘dict’ object containing the following keys (new
     keys may be introduced in future Python versions):

        * “message”: Error message;

        * “exception” (optional): Exception object;

        * “future” (optional): *note asyncio.Future: dc8. instance;

        * “task” (optional): *note asyncio.Task: 1c7. instance;

        * “handle” (optional): *note asyncio.Handle: 1e6c. instance;

        * “protocol” (optional): *note Protocol: 3878. instance;

        * “transport” (optional): *note Transport: 3879. instance;

        * “socket” (optional): *note socket.socket: fa3. instance;

        * “source_traceback” (optional): Traceback of the source;

        * “handle_traceback” (optional): Traceback of the handle;

        * 
          “asyncgen” (optional): Asynchronous generator that caused

               the exception.

          Nota: This method should not be overloaded in subclassed event
          loops.  For custom exception handling, use the *note
          set_exception_handler(): 3893. method.


File: python.info,  Node: Enabling debug mode,  Next: Running Subprocesses,  Prev: Error Handling API,  Up: Event Loop Methods

5.19.1.69 Enabling debug mode
.............................

 -- Metodo: loop.get_debug ()

     Get the debug mode (*note bool: 3c3.) of the event loop.

     The default value is ‘True’ if the environment variable *note
     PYTHONASYNCIODEBUG: 2122. is set to a non-empty string, ‘False’
     otherwise.

 -- Metodo: loop.set_debug (enabled: bool)

     Set the debug mode of the event loop.

     Cambiato nella versione 3.7: The new *note Python Development Mode:
     509. can now also be used to enable the debug mode.

 -- Attributo: loop.slow_callback_duration

     This attribute can be used to set the minimum execution duration in
     seconds that is considered «slow».  When debug mode is enabled,
     «slow» callbacks are logged.

     Default value is 100 milliseconds.

Vedi anche
..........

The *note debug mode of asyncio: 2123.


File: python.info,  Node: Running Subprocesses,  Prev: Enabling debug mode,  Up: Event Loop Methods

5.19.1.70 Running Subprocesses
..............................

Methods described in this subsections are low-level.  In regular
async/await code consider using the high-level *note
asyncio.create_subprocess_shell(): c6e. and *note
asyncio.create_subprocess_exec(): c6d. convenience functions instead.

     Nota: On Windows, the default event loop *note ProactorEventLoop:
     81e. supports subprocesses, whereas *note SelectorEventLoop: 314.
     does not.  See *note Subprocess Support on Windows: 382b. for
     details.

 -- Metodo: async loop.subprocess_exec (protocol_factory, *args,
          stdin=subprocess.PIPE, stdout=subprocess.PIPE,
          stderr=subprocess.PIPE, **kwargs)

     Create a subprocess from one or more string arguments specified by
     'args'.

     'args' must be a list of strings represented by:

        * *note str: 169.;

        * or *note bytes: 192, encoded to the *note filesystem encoding:
          2c1b.

     The first string specifies the program executable, and the
     remaining strings specify the arguments.  Together, string
     arguments form the ‘argv’ of the program.

     This is similar to the standard library *note subprocess.Popen:
     4b8. class called with ‘shell=False’ and the list of strings passed
     as the first argument; however, where *note Popen: 4b8. takes a
     single argument which is list of strings, 'subprocess_exec' takes
     multiple string arguments.

     The 'protocol_factory' must be a callable returning a subclass of
     the *note asyncio.SubprocessProtocol: 3899. class.

     Other parameters:

        * 'stdin' can be any of these:

             * a file-like object

             * an existing file descriptor (a positive integer), for
               example those created with *note os.pipe(): 1b4c.

             * the *note subprocess.PIPE: d82. constant (default) which
               will create a new pipe and connect it,

             * the value ‘None’ which will make the subprocess inherit
               the file descriptor from this process

             * the *note subprocess.DEVNULL: 1356. constant which
               indicates that the special *note os.devnull: 1dfc. file
               will be used

        * 'stdout' can be any of these:

             * a file-like object

             * the *note subprocess.PIPE: d82. constant (default) which
               will create a new pipe and connect it,

             * the value ‘None’ which will make the subprocess inherit
               the file descriptor from this process

             * the *note subprocess.DEVNULL: 1356. constant which
               indicates that the special *note os.devnull: 1dfc. file
               will be used

        * 'stderr' can be any of these:

             * a file-like object

             * the *note subprocess.PIPE: d82. constant (default) which
               will create a new pipe and connect it,

             * the value ‘None’ which will make the subprocess inherit
               the file descriptor from this process

             * the *note subprocess.DEVNULL: 1356. constant which
               indicates that the special *note os.devnull: 1dfc. file
               will be used

             * the *note subprocess.STDOUT: 3713. constant which will
               connect the standard error stream to the process”
               standard output stream

        * All other keyword arguments are passed to *note
          subprocess.Popen: 4b8. without interpretation, except for
          'bufsize', 'universal_newlines', 'shell', 'text', 'encoding'
          and 'errors', which should not be specified at all.

          The ‘asyncio’ subprocess API does not support decoding the
          streams as text.  *note bytes.decode(): ad5. can be used to
          convert the bytes returned from the stream to text.

     If a file-like object passed as 'stdin', 'stdout' or 'stderr'
     represents a pipe, then the other side of this pipe should be
     registered with *note connect_write_pipe(): 382d. or *note
     connect_read_pipe(): 382c. for use with the event loop.

     See the constructor of the *note subprocess.Popen: 4b8. class for
     documentation on other arguments.

     Returns a pair of ‘(transport, protocol)’, where 'transport'
     conforms to the *note asyncio.SubprocessTransport: 389a. base class
     and 'protocol' is an object instantiated by the 'protocol_factory'.

     If the transport is closed or is garbage collected, the child
     process is killed if it is still running.

 -- Metodo: async loop.subprocess_shell (protocol_factory, cmd, *,
          stdin=subprocess.PIPE, stdout=subprocess.PIPE,
          stderr=subprocess.PIPE, **kwargs)

     Create a subprocess from 'cmd', which can be a *note str: 169. or a
     *note bytes: 192. string encoded to the *note filesystem encoding:
     2c1b, using the platform’s «shell» syntax.

     This is similar to the standard library *note subprocess.Popen:
     4b8. class called with ‘shell=True’.

     The 'protocol_factory' must be a callable returning a subclass of
     the *note SubprocessProtocol: 3899. class.

     See *note subprocess_exec(): 3829. for more details about the
     remaining arguments.

     Returns a pair of ‘(transport, protocol)’, where 'transport'
     conforms to the *note SubprocessTransport: 389a. base class and
     'protocol' is an object instantiated by the 'protocol_factory'.

     If the transport is closed or is garbage collected, the child
     process is killed if it is still running.

     Nota: It is the application’s responsibility to ensure that all
     whitespace and special characters are quoted appropriately to avoid
     shell injection(1) vulnerabilities.  The *note shlex.quote(): 582.
     function can be used to properly escape whitespace and special
     characters in strings that are going to be used to construct shell
     commands.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Shell_injection#Shell_injection


File: python.info,  Node: Callback Handles,  Next: Server Objects,  Prev: Event Loop Methods,  Up: Event Loop

5.19.1.71 Callback Handles
..........................

 -- Classe: asyncio.Handle

     A callback wrapper object returned by *note loop.call_soon(): cfc,
     *note loop.call_soon_threadsafe(): cfd.

      -- Metodo: get_context ()

          Return the *note contextvars.Context: 177. object associated
          with the handle.

          Added in version 3.12.

      -- Metodo: cancel ()

          Cancel the callback.  If the callback has already been
          canceled or executed, this method has no effect.

      -- Metodo: cancelled ()

          Return ‘True’ if the callback was cancelled.

          Added in version 3.7.

 -- Classe: asyncio.TimerHandle

     A callback wrapper object returned by *note loop.call_later(): cfe,
     and *note loop.call_at(): cff.

     This class is a subclass of *note Handle: 1e6c.

      -- Metodo: when ()

          Return a scheduled callback time as *note float: 196. seconds.

          The time is an absolute timestamp, using the same time
          reference as *note loop.time(): 3875.

          Added in version 3.7.


File: python.info,  Node: Server Objects,  Next: Event Loop Implementations,  Prev: Callback Handles,  Up: Event Loop

5.19.1.72 Server Objects
........................

Server objects are created by *note loop.create_server(): d0b, *note
loop.create_unix_server(): 4cb, *note start_server(): d11, and *note
start_unix_server(): 37e6. functions.

Do not instantiate the *note Server: d0a. class directly.

 -- Classe: asyncio.Server

     'Server' objects are asynchronous context managers.  When used in
     an ‘async with’ statement, it’s guaranteed that the Server object
     is closed and not accepting new connections when the ‘async with’
     statement is completed:

          srv = await loop.create_server(...)

          async with srv:
              # some code

          # At this point, srv is closed and no longer accepts new connections.

     Cambiato nella versione 3.7: Server object is an asynchronous
     context manager since Python 3.7.

     Cambiato nella versione 3.11: This class was exposed publicly as
     ‘asyncio.Server’ in Python 3.9.11, 3.10.3 and 3.11.

      -- Metodo: close ()

          Stop serving: close listening sockets and set the *note
          sockets: e12. attribute to ‘None’.

          The sockets that represent existing incoming client
          connections are left open.

          The server is closed asynchronously; use the *note
          wait_closed(): 1a27. coroutine to wait until the server is
          closed (and no more connections are active).

      -- Metodo: close_clients ()

          Close all existing incoming client connections.

          Calls *note close(): 387c. on all associated transports.

          *note close(): 37e3. should be called before *note
          close_clients(): 4cf. when closing the server to avoid races
          with new clients connecting.

          Added in version 3.13.

      -- Metodo: abort_clients ()

          Close all existing incoming client connections immediately,
          without waiting for pending operations to complete.

          Calls *note abort(): 389d. on all associated transports.

          *note close(): 37e3. should be called before *note
          abort_clients(): 4d0. when closing the server to avoid races
          with new clients connecting.

          Added in version 3.13.

      -- Metodo: get_loop ()

          Return the event loop associated with the server object.

          Added in version 3.7.

      -- Metodo: async start_serving ()

          Start accepting connections.

          This method is idempotent, so it can be called when the server
          is already serving.

          The 'start_serving' keyword-only parameter to *note
          loop.create_server(): d0b. and *note asyncio.start_server():
          d11. allows creating a Server object that is not accepting
          connections initially.  In this case ‘Server.start_serving()’,
          or *note Server.serve_forever(): d0d. can be used to make the
          Server start accepting connections.

          Added in version 3.7.

      -- Metodo: async serve_forever ()

          Start accepting connections until the coroutine is cancelled.
          Cancellation of ‘serve_forever’ task causes the server to be
          closed.

          This method can be called if the server is already accepting
          connections.  Only one ‘serve_forever’ task can exist per one
          'Server' object.

          Example:

               async def client_connected(reader, writer):
                   # Communicate with the client with
                   # reader/writer streams.  For example:
                   await reader.readline()

               async def main(host, port):
                   srv = await asyncio.start_server(
                       client_connected, host, port)
                   await srv.serve_forever()

               asyncio.run(main('127.0.0.1', 0))

          Added in version 3.7.

      -- Metodo: is_serving ()

          Return ‘True’ if the server is accepting new connections.

          Added in version 3.7.

      -- Metodo: async wait_closed ()

          Wait until the *note close(): 37e3. method completes and all
          active connections have finished.

      -- Attributo: sockets

          List of socket-like objects, ‘asyncio.trsock.TransportSocket’,
          which the server is listening on.

          Cambiato nella versione 3.7: Prior to Python 3.7
          ‘Server.sockets’ used to return an internal list of server
          sockets directly.  In 3.7 a copy of that list is returned.


File: python.info,  Node: Event Loop Implementations,  Next: Examples<19>,  Prev: Server Objects,  Up: Event Loop

5.19.1.73 Event Loop Implementations
....................................

asyncio ships with two different event loop implementations: *note
SelectorEventLoop: 314. and *note ProactorEventLoop: 81e.

By default asyncio is configured to use *note EventLoop: 1a4f.

 -- Classe: asyncio.SelectorEventLoop

     A subclass of *note AbstractEventLoop: b5a. based on the *note
     selectors: c7. module.

     Uses the most efficient 'selector' available for the given
     platform.  It is also possible to manually configure the exact
     selector implementation to be used:

          import asyncio
          import selectors

          async def main():
             ...

          loop_factory = lambda: asyncio.SelectorEventLoop(selectors.SelectSelector())
          asyncio.run(main(), loop_factory=loop_factory)

     *note Availability: 2128.: Unix, Windows.

 -- Classe: asyncio.ProactorEventLoop

     A subclass of *note AbstractEventLoop: b5a. for Windows that uses
     «I/O Completion Ports» (IOCP).

     *note Availability: 2128.: Windows.

     Vedi anche
     ..........

     MSDN documentation on I/O Completion Ports(1).

 -- Classe: asyncio.EventLoop

          An alias to the most efficient available subclass of *note
          AbstractEventLoop: b5a. for the given platform.

          It is an alias to *note SelectorEventLoop: 314. on Unix and
          *note ProactorEventLoop: 81e. on Windows.

     Added in version 3.13.

 -- Classe: asyncio.AbstractEventLoop

     Abstract base class for asyncio-compliant event loops.

     The *note Event Loop Methods: 386c. section lists all methods that
     an alternative implementation of ‘AbstractEventLoop’ should have
     defined.

   ---------- Footnotes ----------

   (1) 
https://learn.microsoft.com/windows/win32/fileio/i-o-completion-ports


File: python.info,  Node: Examples<19>,  Prev: Event Loop Implementations,  Up: Event Loop

5.19.1.74 Examples
..................

Note that all examples in this section 'purposefully' show how to use
the low-level event loop APIs, such as *note loop.run_forever(): 386e.
and *note loop.call_soon(): cfc.  Modern asyncio applications rarely
need to be written this way; consider using the high-level functions
like *note asyncio.run(): 2f3.

* Menu:

* Hello World with call_soon(): Hello World with call_soon.
* Display the current date with call_later(): Display the current date with call_later.
* Watch a file descriptor for read events::
* Set signal handlers for SIGINT and SIGTERM::


File: python.info,  Node: Hello World with call_soon,  Next: Display the current date with call_later,  Up: Examples<19>

5.19.1.75 Hello World with call_soon()
......................................

An example using the *note loop.call_soon(): cfc. method to schedule a
callback.  The callback displays ‘"Hello World"’ and then stops the
event loop:

     import asyncio

     def hello_world(loop):
         """A callback to print 'Hello World' and stop the event loop"""
         print('Hello World')
         loop.stop()

     loop = asyncio.new_event_loop()

     # Schedule a call to hello_world()
     loop.call_soon(hello_world, loop)

     # Blocking call interrupted by loop.stop()
     try:
         loop.run_forever()
     finally:
         loop.close()

Vedi anche
..........

A similar *note Hello World: 379e. example created with a coroutine and
the *note run(): 2f3. function.


File: python.info,  Node: Display the current date with call_later,  Next: Watch a file descriptor for read events,  Prev: Hello World with call_soon,  Up: Examples<19>

5.19.1.76 Display the current date with call_later()
....................................................

An example of a callback displaying the current date every second.  The
callback uses the *note loop.call_later(): cfe. method to reschedule
itself after 5 seconds, and then stops the event loop:

     import asyncio
     import datetime

     def display_date(end_time, loop):
         print(datetime.datetime.now())
         if (loop.time() + 1.0) < end_time:
             loop.call_later(1, display_date, end_time, loop)
         else:
             loop.stop()

     loop = asyncio.new_event_loop()

     # Schedule the first call to display_date()
     end_time = loop.time() + 5.0
     loop.call_soon(display_date, end_time, loop)

     # Blocking call interrupted by loop.stop()
     try:
         loop.run_forever()
     finally:
         loop.close()

Vedi anche
..........

A similar *note current date: 37bd. example created with a coroutine and
the *note run(): 2f3. function.


File: python.info,  Node: Watch a file descriptor for read events,  Next: Set signal handlers for SIGINT and SIGTERM,  Prev: Display the current date with call_later,  Up: Examples<19>

5.19.1.77 Watch a file descriptor for read events
.................................................

Wait until a file descriptor received some data using the *note
loop.add_reader(): 3800. method and then close the event loop:

     import asyncio
     from socket import socketpair

     # Create a pair of connected file descriptors
     rsock, wsock = socketpair()

     loop = asyncio.new_event_loop()

     def reader():
         data = rsock.recv(100)
         print("Received:", data.decode())

         # We are done: unregister the file descriptor
         loop.remove_reader(rsock)

         # Stop the event loop
         loop.stop()

     # Register the file descriptor for read event
     loop.add_reader(rsock, reader)

     # Simulate the reception of data from the network
     loop.call_soon(wsock.send, 'abc'.encode())

     try:
         # Run the event loop
         loop.run_forever()
     finally:
         # We are done. Close sockets and the event loop.
         rsock.close()
         wsock.close()
         loop.close()

Vedi anche
..........

   * A similar *note example: 37fe. using transports, protocols, and the
     *note loop.create_connection(): 819. method.

   * Another similar *note example: 37fc. using the high-level *note
     asyncio.open_connection(): d10. function and streams.


File: python.info,  Node: Set signal handlers for SIGINT and SIGTERM,  Prev: Watch a file descriptor for read events,  Up: Examples<19>

5.19.1.78 Set signal handlers for SIGINT and SIGTERM
....................................................

(This ‘signals’ example only works on Unix.)

Register handlers for signals *note SIGINT: 253. and *note SIGTERM:
15e6. using the *note loop.add_signal_handler(): 388f. method:

     import asyncio
     import functools
     import os
     import signal

     def ask_exit(signame, loop):
         print("got signal %s: exit" % signame)
         loop.stop()

     async def main():
         loop = asyncio.get_running_loop()

         for signame in {'SIGINT', 'SIGTERM'}:
             loop.add_signal_handler(
                 getattr(signal, signame),
                 functools.partial(ask_exit, signame, loop))

         await asyncio.sleep(3600)

     print("Event loop running for 1 hour, press Ctrl+C to interrupt.")
     print(f"pid {os.getpid()}: send SIGINT or SIGTERM to exit.")

     asyncio.run(main())


File: python.info,  Node: Futures,  Next: Transports and Protocols,  Prev: Event Loop,  Up: asyncio — Asynchronous I/O

5.19.1.79 Futures
.................

'Source code:' Lib/asyncio/futures.py(1), Lib/asyncio/base_futures.py(2)

__________________________________________________________________

'Future' objects are used to bridge 'low-level callback-based code' with
high-level async/await code.

* Menu:

* Future Functions::
* Future Object::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/futures.py

   (2) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/base_futures.py


File: python.info,  Node: Future Functions,  Next: Future Object,  Up: Futures

5.19.1.80 Future Functions
..........................

 -- Funzione: asyncio.isfuture (obj)

     Return ‘True’ if 'obj' is either of:

        * an instance of *note asyncio.Future: dc8,

        * an instance of *note asyncio.Task: 1c7,

        * a Future-like object with a ‘_asyncio_future_blocking’
          attribute.

     Added in version 3.5.

 -- Funzione: asyncio.ensure_future (obj, *, loop=None)

     Return:

        * 'obj' argument as is, if 'obj' is a *note Future: dc8, a *note
          Task: 1c7, or a Future-like object (*note isfuture(): 38aa. is
          used for the test.)

        * a *note Task: 1c7. object wrapping 'obj', if 'obj' is a
          coroutine (*note iscoroutine(): 6a7. is used for the test); in
          this case the coroutine will be scheduled by
          ‘ensure_future()’.

        * a *note Task: 1c7. object that would await on 'obj', if 'obj'
          is an awaitable (*note inspect.isawaitable(): 101a. is used
          for the test.)

     If 'obj' is neither of the above a *note TypeError: 198. is raised.

          Importante: Save a reference to the result of this function,
          to avoid a task disappearing mid-execution.

          See also the *note create_task(): 1c9. function which is the
          preferred way for creating new tasks or use *note
          asyncio.TaskGroup: 4d2. which keeps reference to the task
          internally.

     Cambiato nella versione 3.5.1: The function accepts any *note
     awaitable: 4ca. object.

     Deprecato dalla versione 3.10: Deprecation warning is emitted if
     'obj' is not a Future-like object and 'loop' is not specified and
     there is no running event loop.

 -- Funzione: asyncio.wrap_future (future, *, loop=None)

     Wrap a *note concurrent.futures.Future: 13ba. object in a *note
     asyncio.Future: dc8. object.

     Deprecato dalla versione 3.10: Deprecation warning is emitted if
     'future' is not a Future-like object and 'loop' is not specified
     and there is no running event loop.


File: python.info,  Node: Future Object,  Prev: Future Functions,  Up: Futures

5.19.1.81 Future Object
.......................

 -- Classe: asyncio.Future (*, loop=None)

     A Future represents an eventual result of an asynchronous
     operation.  Not thread-safe.

     Future is an *note awaitable: 4ca. object.  Coroutines can await on
     Future objects until they either have a result or an exception set,
     or until they are cancelled.  A Future can be awaited multiple
     times and the result is same.

     Typically Futures are used to enable low-level callback-based code
     (e.g.  in protocols implemented using asyncio *note transports:
     37a6.) to interoperate with high-level async/await code.

     The rule of thumb is to never expose Future objects in user-facing
     APIs, and the recommended way to create a Future object is to call
     *note loop.create_future(): e76.  This way alternative event loop
     implementations can inject their own optimized implementations of a
     Future object.

     Cambiato nella versione 3.7: Added support for the *note
     contextvars: 28. module.

     Deprecato dalla versione 3.10: Deprecation warning is emitted if
     'loop' is not specified and there is no running event loop.

      -- Metodo: result ()

          Return the result of the Future.

          If the Future is 'done' and has a result set by the *note
          set_result(): 37d3. method, the result value is returned.

          If the Future is 'done' and has an exception set by the *note
          set_exception(): e7a. method, this method raises the
          exception.

          If the Future has been 'cancelled', this method raises a *note
          CancelledError: 4d5. exception.

          If the Future’s result isn’t yet available, this method raises
          an *note InvalidStateError: 37d6. exception.

      -- Metodo: set_result (result)

          Mark the Future as 'done' and set its result.

          Raises an *note InvalidStateError: 37d6. error if the Future
          is already 'done'.

      -- Metodo: set_exception (exception)

          Mark the Future as 'done' and set an exception.

          Raises an *note InvalidStateError: 37d6. error if the Future
          is already 'done'.

      -- Metodo: done ()

          Return ‘True’ if the Future is 'done'.

          A Future is 'done' if it was 'cancelled' or if it has a result
          or an exception set with *note set_result(): 37d3. or *note
          set_exception(): e7a. calls.

      -- Metodo: cancelled ()

          Return ‘True’ if the Future was 'cancelled'.

          The method is usually used to check if a Future is not
          'cancelled' before setting a result or an exception for it:

               if not fut.cancelled():
                   fut.set_result(42)

      -- Metodo: add_done_callback (callback, *, context=None)

          Add a callback to be run when the Future is 'done'.

          The 'callback' is called with the Future object as its only
          argument.

          If the Future is already 'done' when this method is called,
          the callback is scheduled with *note loop.call_soon(): cfc.

          An optional keyword-only 'context' argument allows specifying
          a custom *note contextvars.Context: 177. for the 'callback' to
          run in.  The current context is used when no 'context' is
          provided.

          *note functools.partial(): 217. can be used to pass parameters
          to the callback, e.g.:

               # Call 'print("Future:", fut)' when "fut" is done.
               fut.add_done_callback(
                   functools.partial(print, "Future:"))

          Cambiato nella versione 3.7: The 'context' keyword-only
          parameter was added.  See PEP 567(1) for more details.

      -- Metodo: remove_done_callback (callback)

          Remove 'callback' from the callbacks list.

          Returns the number of callbacks removed, which is typically 1,
          unless a callback was added more than once.

      -- Metodo: cancel (msg=None)

          Cancel the Future and schedule callbacks.

          If the Future is already 'done' or 'cancelled', return
          ‘False’.  Otherwise, change the Future’s state to 'cancelled',
          schedule the callbacks, and return ‘True’.

          Cambiato nella versione 3.9: Added the 'msg' parameter.

      -- Metodo: exception ()

          Return the exception that was set on this Future.

          The exception (or ‘None’ if no exception was set) is returned
          only if the Future is 'done'.

          If the Future has been 'cancelled', this method raises a *note
          CancelledError: 4d5. exception.

          If the Future isn’t 'done' yet, this method raises an *note
          InvalidStateError: 37d6. exception.

      -- Metodo: get_loop ()

          Return the event loop the Future object is bound to.

          Added in version 3.7.

This example creates a Future object, creates and schedules an
asynchronous Task to set result for the Future, and waits until the
Future has a result:

     async def set_after(fut, delay, value):
         # Sleep for *delay* seconds.
         await asyncio.sleep(delay)

         # Set *value* as a result of *fut* Future.
         fut.set_result(value)

     async def main():
         # Get the current event loop.
         loop = asyncio.get_running_loop()

         # Create a new Future object.
         fut = loop.create_future()

         # Run "set_after()" coroutine in a parallel Task.
         # We are using the low-level "loop.create_task()" API here because
         # we already have a reference to the event loop at hand.
         # Otherwise we could have just used "asyncio.create_task()".
         loop.create_task(
             set_after(fut, 1, '... world'))

         print('hello ...')

         # Wait until *fut* has a result (1 second) and print it.
         print(await fut)

     asyncio.run(main())

     Importante: The Future object was designed to mimic *note
     concurrent.futures.Future: 13ba.  Key differences include:

        - unlike asyncio Futures, *note concurrent.futures.Future: 13ba.
          instances cannot be awaited.

        - *note asyncio.Future.result(): 38ad. and *note
          asyncio.Future.exception(): 38b0. do not accept the 'timeout'
          argument.

        - *note asyncio.Future.result(): 38ad. and *note
          asyncio.Future.exception(): 38b0. raise an *note
          InvalidStateError: 37d6. exception when the Future is not
          'done'.

        - Callbacks registered with *note
          asyncio.Future.add_done_callback(): d00. are not called
          immediately.  They are scheduled with *note loop.call_soon():
          cfc. instead.

        - asyncio Future is not compatible with the *note
          concurrent.futures.wait(): 1bed. and *note
          concurrent.futures.as_completed(): 19af. functions.

        - *note asyncio.Future.cancel(): 1b91. accepts an optional ‘msg’
          argument, but *note concurrent.futures.Future.cancel(): 36d4.
          does not.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0567/


File: python.info,  Node: Transports and Protocols,  Next: Policies,  Prev: Futures,  Up: asyncio — Asynchronous I/O

5.19.1.82 Transports and Protocols
..................................

Preface
.......

Transports and Protocols are used by the 'low-level' event loop APIs
such as *note loop.create_connection(): 819.  They use callback-based
programming style and enable high-performance implementations of network
or IPC protocols (e.g.  HTTP).

Essentially, transports and protocols should only be used in libraries
and frameworks and never in high-level asyncio applications.

This documentation page covers both *note Transports: 38b5. and *note
Protocols: 38b6.

Introduction
............

At the highest level, the transport is concerned with 'how' bytes are
transmitted, while the protocol determines 'which' bytes to transmit
(and to some extent when).

A different way of saying the same thing: a transport is an abstraction
for a socket (or similar I/O endpoint) while a protocol is an
abstraction for an application, from the transport’s point of view.

Yet another view is the transport and protocol interfaces together
define an abstract interface for using network I/O and interprocess I/O.

There is always a 1:1 relationship between transport and protocol
objects: the protocol calls transport methods to send data, while the
transport calls protocol methods to pass it data that has been received.

Most of connection oriented event loop methods (such as *note
loop.create_connection(): 819.) usually accept a 'protocol_factory'
argument used to create a 'Protocol' object for an accepted connection,
represented by a 'Transport' object.  Such methods usually return a
tuple of ‘(transport, protocol)’.

Contents
........

This documentation page contains the following sections:

   * The *note Transports: 38b5. section documents asyncio *note
     BaseTransport: 38b7, *note ReadTransport: 388c, *note
     WriteTransport: 388d, *note Transport: 38b8, *note
     DatagramTransport: 1b0f, and *note SubprocessTransport: 389a.
     classes.

   * The *note Protocols: 38b6. section documents asyncio *note
     BaseProtocol: 38b9, *note Protocol: 38ba, *note BufferedProtocol:
     c96, *note DatagramProtocol: 8df, and *note SubprocessProtocol:
     3899. classes.

   * The *note Examples: 38bb. section showcases how to work with
     transports, protocols, and low-level event loop APIs.

* Menu:

* Transports::
* Protocols: Protocols<2>.
* Examples: Examples<20>.


File: python.info,  Node: Transports,  Next: Protocols<2>,  Up: Transports and Protocols

5.19.1.83 Transports
....................

'Source code:' Lib/asyncio/transports.py(1)

__________________________________________________________________

Transports are classes provided by *note asyncio: b. in order to
abstract various kinds of communication channels.

Transport objects are always instantiated by an *note asyncio event
loop: f78.

asyncio implements transports for TCP, UDP, SSL, and subprocess pipes.
The methods available on a transport depend on the transport’s kind.

The transport classes are *note not thread safe: 37ce.

* Menu:

* Transports Hierarchy::
* Base Transport::
* Read-only Transports::
* Write-only Transports::
* Datagram Transports::
* Subprocess Transports::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/transports.py


File: python.info,  Node: Transports Hierarchy,  Next: Base Transport,  Up: Transports

5.19.1.84 Transports Hierarchy
..............................

 -- Classe: asyncio.BaseTransport

     Base class for all transports.  Contains methods that all asyncio
     transports share.

 -- Classe: asyncio.WriteTransport (BaseTransport)

     A base transport for write-only connections.

     Instances of the 'WriteTransport' class are returned from the *note
     loop.connect_write_pipe(): 382d. event loop method and are also
     used by subprocess-related methods like *note
     loop.subprocess_exec(): 3829.

 -- Classe: asyncio.ReadTransport (BaseTransport)

     A base transport for read-only connections.

     Instances of the 'ReadTransport' class are returned from the *note
     loop.connect_read_pipe(): 382c. event loop method and are also used
     by subprocess-related methods like *note loop.subprocess_exec():
     3829.

 -- Classe: asyncio.Transport (WriteTransport, ReadTransport)

     Interface representing a bidirectional transport, such as a TCP
     connection.

     The user does not instantiate a transport directly; they call a
     utility function, passing it a protocol factory and other
     information necessary to create the transport and protocol.

     Instances of the 'Transport' class are returned from or used by
     event loop methods like *note loop.create_connection(): 819, *note
     loop.create_unix_connection(): 37e5, *note loop.create_server():
     d0b, *note loop.sendfile(): 3882, etc.

 -- Classe: asyncio.DatagramTransport (BaseTransport)

     A transport for datagram (UDP) connections.

     Instances of the 'DatagramTransport' class are returned from the
     *note loop.create_datagram_endpoint(): 93d. event loop method.

 -- Classe: asyncio.SubprocessTransport (BaseTransport)

     An abstraction to represent a connection between a parent and its
     child OS process.

     Instances of the 'SubprocessTransport' class are returned from
     event loop methods *note loop.subprocess_shell(): 382a. and *note
     loop.subprocess_exec(): 3829.


File: python.info,  Node: Base Transport,  Next: Read-only Transports,  Prev: Transports Hierarchy,  Up: Transports

5.19.1.85 Base Transport
........................

 -- Metodo: BaseTransport.close ()

     Close the transport.

     If the transport has a buffer for outgoing data, buffered data will
     be flushed asynchronously.  No more data will be received.  After
     all buffered data is flushed, the protocol’s *note
     protocol.connection_lost(): 38be. method will be called with *note
     None: 886. as its argument.  The transport should not be used once
     it is closed.

 -- Metodo: BaseTransport.is_closing ()

     Return ‘True’ if the transport is closing or is closed.

 -- Metodo: BaseTransport.get_extra_info (name, default=None)

     Return information about the transport or underlying resources it
     uses.

     'name' is a string representing the piece of transport-specific
     information to get.

     'default' is the value to return if the information is not
     available, or if the transport does not support querying it with
     the given third-party event loop implementation or on the current
     platform.

     For example, the following code attempts to get the underlying
     socket object of the transport:

          sock = transport.get_extra_info('socket')
          if sock is not None:
              print(sock.getsockopt(...))

     Categories of information that can be queried on some transports:

        * socket:

             - ‘'peername'’: the remote address to which the socket is
               connected, result of *note socket.socket.getpeername():
               38bf. (‘None’ on error)

             - ‘'socket'’: *note socket.socket: fa3. instance

             - ‘'sockname'’: the socket’s own address, result of *note
               socket.socket.getsockname(): 284.

        * SSL socket:

             - ‘'compression'’: the compression algorithm being used as
               a string, or ‘None’ if the connection isn’t compressed;
               result of *note ssl.SSLSocket.compression(): 134d.

             - ‘'cipher'’: a three-value tuple containing the name of
               the cipher being used, the version of the SSL protocol
               that defines its use, and the number of secret bits being
               used; result of *note ssl.SSLSocket.cipher(): 38c0.

             - ‘'peercert'’: peer certificate; result of *note
               ssl.SSLSocket.getpeercert(): 11ba.

             - ‘'sslcontext'’: *note ssl.SSLContext: 357. instance

             - ‘'ssl_object'’: *note ssl.SSLObject: d7c. or *note
               ssl.SSLSocket: ae9. instance

        * pipe:

             - ‘'pipe'’: pipe object

        * subprocess:

             - ‘'subprocess'’: *note subprocess.Popen: 4b8. instance

 -- Metodo: BaseTransport.set_protocol (protocol)

     Set a new protocol.

     Switching protocol should only be done when both protocols are
     documented to support the switch.

 -- Metodo: BaseTransport.get_protocol ()

     Return the current protocol.


File: python.info,  Node: Read-only Transports,  Next: Write-only Transports,  Prev: Base Transport,  Up: Transports

5.19.1.86 Read-only Transports
..............................

 -- Metodo: ReadTransport.is_reading ()

     Return ‘True’ if the transport is receiving new data.

     Added in version 3.7.

 -- Metodo: ReadTransport.pause_reading ()

     Pause the receiving end of the transport.  No data will be passed
     to the protocol’s *note protocol.data_received(): 1aea. method
     until *note resume_reading(): d14. is called.

     Cambiato nella versione 3.7: The method is idempotent, i.e.  it can
     be called when the transport is already paused or closed.

 -- Metodo: ReadTransport.resume_reading ()

     Resume the receiving end.  The protocol’s *note
     protocol.data_received(): 1aea. method will be called once again if
     some data is available for reading.

     Cambiato nella versione 3.7: The method is idempotent, i.e.  it can
     be called when the transport is already reading.


File: python.info,  Node: Write-only Transports,  Next: Datagram Transports,  Prev: Read-only Transports,  Up: Transports

5.19.1.87 Write-only Transports
...............................

 -- Metodo: WriteTransport.abort ()

     Close the transport immediately, without waiting for pending
     operations to complete.  Buffered data will be lost.  No more data
     will be received.  The protocol’s *note protocol.connection_lost():
     38be. method will eventually be called with *note None: 886. as its
     argument.

 -- Metodo: WriteTransport.can_write_eof ()

     Return *note True: e09. if the transport supports *note
     write_eof(): 38c6, *note False: d2d. if not.

 -- Metodo: WriteTransport.get_write_buffer_size ()

     Return the current size of the output buffer used by the transport.

 -- Metodo: WriteTransport.get_write_buffer_limits ()

     Get the 'high' and 'low' watermarks for write flow control.  Return
     a tuple ‘(low, high)’ where 'low' and 'high' are positive number of
     bytes.

     Use *note set_write_buffer_limits(): 38c8. to set the limits.

     Added in version 3.4.2.

 -- Metodo: WriteTransport.set_write_buffer_limits (high=None, low=None)

     Set the 'high' and 'low' watermarks for write flow control.

     These two values (measured in number of bytes) control when the
     protocol’s *note protocol.pause_writing(): 38c9. and *note
     protocol.resume_writing(): 38ca. methods are called.  If specified,
     the low watermark must be less than or equal to the high watermark.
     Neither 'high' nor 'low' can be negative.

     *note pause_writing(): 38c9. is called when the buffer size becomes
     greater than or equal to the 'high' value.  If writing has been
     paused, *note resume_writing(): 38ca. is called when the buffer
     size becomes less than or equal to the 'low' value.

     The defaults are implementation-specific.  If only the high
     watermark is given, the low watermark defaults to an
     implementation-specific value less than or equal to the high
     watermark.  Setting 'high' to zero forces 'low' to zero as well,
     and causes *note pause_writing(): 38c9. to be called whenever the
     buffer becomes non-empty.  Setting 'low' to zero causes *note
     resume_writing(): 38ca. to be called only once the buffer is empty.
     Use of zero for either limit is generally sub-optimal as it reduces
     opportunities for doing I/O and computation concurrently.

     Use *note get_write_buffer_limits(): fc6. to get the limits.

 -- Metodo: WriteTransport.write (data)

     Write some 'data' bytes to the transport.

     This method does not block; it buffers the data and arranges for it
     to be sent out asynchronously.

 -- Metodo: WriteTransport.writelines (list_of_data)

     Write a list (or any iterable) of data bytes to the transport.
     This is functionally equivalent to calling *note write(): 17b2. on
     each element yielded by the iterable, but may be implemented more
     efficiently.

 -- Metodo: WriteTransport.write_eof ()

     Close the write end of the transport after flushing all buffered
     data.  Data may still be received.

     This method can raise *note NotImplementedError: 36b. if the
     transport (e.g.  SSL) doesn’t support half-closed connections.


File: python.info,  Node: Datagram Transports,  Next: Subprocess Transports,  Prev: Write-only Transports,  Up: Transports

5.19.1.88 Datagram Transports
.............................

 -- Metodo: DatagramTransport.sendto (data, addr=None)

     Send the 'data' bytes to the remote peer given by 'addr' (a
     transport-dependent target address).  If 'addr' is *note None: 886,
     the data is sent to the target address given on transport creation.

     This method does not block; it buffers the data and arranges for it
     to be sent out asynchronously.

     Cambiato nella versione 3.13: This method can be called with an
     empty bytes object to send a zero-length datagram.  The buffer size
     calculation used for flow control is also updated to account for
     the datagram header.

 -- Metodo: DatagramTransport.abort ()

     Close the transport immediately, without waiting for pending
     operations to complete.  Buffered data will be lost.  No more data
     will be received.  The protocol’s *note protocol.connection_lost():
     38be. method will eventually be called with *note None: 886. as its
     argument.


File: python.info,  Node: Subprocess Transports,  Prev: Datagram Transports,  Up: Transports

5.19.1.89 Subprocess Transports
...............................

 -- Metodo: SubprocessTransport.get_pid ()

     Return the subprocess process id as an integer.

 -- Metodo: SubprocessTransport.get_pipe_transport (fd)

     Return the transport for the communication pipe corresponding to
     the integer file descriptor 'fd':

        * ‘0’: writable streaming transport of the standard input
          ('stdin'), or *note None: 886. if the subprocess was not
          created with ‘stdin=PIPE’

        * ‘1’: readable streaming transport of the standard output
          ('stdout'), or *note None: 886. if the subprocess was not
          created with ‘stdout=PIPE’

        * ‘2’: readable streaming transport of the standard error
          ('stderr'), or *note None: 886. if the subprocess was not
          created with ‘stderr=PIPE’

        * other 'fd': *note None: 886.

 -- Metodo: SubprocessTransport.get_returncode ()

     Return the subprocess return code as an integer or *note None: 886.
     if it hasn’t returned, which is similar to the *note
     subprocess.Popen.returncode: c85. attribute.

 -- Metodo: SubprocessTransport.kill ()

     Kill the subprocess.

     On POSIX systems, the function sends SIGKILL to the subprocess.  On
     Windows, this method is an alias for *note terminate(): 38d2.

     See also *note subprocess.Popen.kill(): 15e4.

 -- Metodo: SubprocessTransport.send_signal (signal)

     Send the 'signal' number to the subprocess, as in *note
     subprocess.Popen.send_signal(): 15e5.

 -- Metodo: SubprocessTransport.terminate ()

     Stop the subprocess.

     On POSIX systems, this method sends *note SIGTERM: 15e6. to the
     subprocess.  On Windows, the Windows API function
     ‘TerminateProcess()’ is called to stop the subprocess.

     See also *note subprocess.Popen.terminate(): 15e3.

 -- Metodo: SubprocessTransport.close ()

     Kill the subprocess by calling the *note kill(): 38d1. method.

     If the subprocess hasn’t returned yet, and close transports of
     'stdin', 'stdout', and 'stderr' pipes.


File: python.info,  Node: Protocols<2>,  Next: Examples<20>,  Prev: Transports,  Up: Transports and Protocols

5.19.1.90 Protocols
...................

'Source code:' Lib/asyncio/protocols.py(1)

__________________________________________________________________

asyncio provides a set of abstract base classes that should be used to
implement network protocols.  Those classes are meant to be used
together with *note transports: 3879.

Subclasses of abstract base protocol classes may implement some or all
methods.  All these methods are callbacks: they are called by transports
on certain events, for example when some data is received.  A base
protocol method should be called by the corresponding transport.

* Menu:

* Base Protocols::
* Base Protocol::
* Streaming Protocols::
* Buffered Streaming Protocols::
* Datagram Protocols::
* Subprocess Protocols::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/protocols.py


File: python.info,  Node: Base Protocols,  Next: Base Protocol,  Up: Protocols<2>

5.19.1.91 Base Protocols
........................

 -- Classe: asyncio.BaseProtocol

     Base protocol with methods that all protocols share.

 -- Classe: asyncio.Protocol (BaseProtocol)

     The base class for implementing streaming protocols (TCP, Unix
     sockets, etc).

 -- Classe: asyncio.BufferedProtocol (BaseProtocol)

     A base class for implementing streaming protocols with manual
     control of the receive buffer.

 -- Classe: asyncio.DatagramProtocol (BaseProtocol)

     The base class for implementing datagram (UDP) protocols.

 -- Classe: asyncio.SubprocessProtocol (BaseProtocol)

     The base class for implementing protocols communicating with child
     processes (unidirectional pipes).


File: python.info,  Node: Base Protocol,  Next: Streaming Protocols,  Prev: Base Protocols,  Up: Protocols<2>

5.19.1.92 Base Protocol
.......................

All asyncio protocols can implement Base Protocol callbacks.

Connection Callbacks
....................

Connection callbacks are called on all protocols, exactly once per a
successful connection.  All other protocol callbacks can only be called
between those two methods.

 -- Metodo: BaseProtocol.connection_made (transport)

     Called when a connection is made.

     The 'transport' argument is the transport representing the
     connection.  The protocol is responsible for storing the reference
     to its transport.

 -- Metodo: BaseProtocol.connection_lost (exc)

     Called when the connection is lost or closed.

     The argument is either an exception object or *note None: 886.  The
     latter means a regular EOF is received, or the connection was
     aborted or closed by this side of the connection.

Flow Control Callbacks
......................

Flow control callbacks can be called by transports to pause or resume
writing performed by the protocol.

See the documentation of the *note set_write_buffer_limits(): 38c8.
method for more details.

 -- Metodo: BaseProtocol.pause_writing ()

     Called when the transport’s buffer goes over the high watermark.

 -- Metodo: BaseProtocol.resume_writing ()

     Called when the transport’s buffer drains below the low watermark.

If the buffer size equals the high watermark, *note pause_writing():
38c9. is not called: the buffer size must go strictly over.

Conversely, *note resume_writing(): 38ca. is called when the buffer size
is equal or lower than the low watermark.  These end conditions are
important to ensure that things go as expected when either mark is zero.


File: python.info,  Node: Streaming Protocols,  Next: Buffered Streaming Protocols,  Prev: Base Protocol,  Up: Protocols<2>

5.19.1.93 Streaming Protocols
.............................

Event methods, such as *note loop.create_server(): d0b, *note
loop.create_unix_server(): 4cb, *note loop.create_connection(): 819,
*note loop.create_unix_connection(): 37e5, *note
loop.connect_accepted_socket(): 9e0, *note loop.connect_read_pipe():
382c, and *note loop.connect_write_pipe(): 382d. accept factories that
return streaming protocols.

 -- Metodo: Protocol.data_received (data)

     Called when some data is received.  'data' is a non-empty bytes
     object containing the incoming data.

     Whether the data is buffered, chunked or reassembled depends on the
     transport.  In general, you shouldn’t rely on specific semantics
     and instead make your parsing generic and flexible.  However, data
     is always received in the correct order.

     The method can be called an arbitrary number of times while a
     connection is open.

     However, *note protocol.eof_received(): 38d8. is called at most
     once.  Once ‘eof_received()’ is called, ‘data_received()’ is not
     called anymore.

 -- Metodo: Protocol.eof_received ()

     Called when the other end signals it won’t send any more data (for
     example by calling *note transport.write_eof(): 38c6, if the other
     end also uses asyncio).

     This method may return a false value (including ‘None’), in which
     case the transport will close itself.  Conversely, if this method
     returns a true value, the protocol used determines whether to close
     the transport.  Since the default implementation returns ‘None’, it
     implicitly closes the connection.

     Some transports, including SSL, don’t support half-closed
     connections, in which case returning true from this method will
     result in the connection being closed.

State machine:

     start -> connection_made
         [-> data_received]*
         [-> eof_received]?
     -> connection_lost -> end


File: python.info,  Node: Buffered Streaming Protocols,  Next: Datagram Protocols,  Prev: Streaming Protocols,  Up: Protocols<2>

5.19.1.94 Buffered Streaming Protocols
......................................

Added in version 3.7.

Buffered Protocols can be used with any event loop method that supports
*note Streaming Protocols: 38d7.

‘BufferedProtocol’ implementations allow explicit manual allocation and
control of the receive buffer.  Event loops can then use the buffer
provided by the protocol to avoid unnecessary data copies.  This can
result in noticeable performance improvement for protocols that receive
big amounts of data.  Sophisticated protocol implementations can
significantly reduce the number of buffer allocations.

The following callbacks are called on *note BufferedProtocol: c96.
instances:

 -- Metodo: BufferedProtocol.get_buffer (sizehint)

     Called to allocate a new receive buffer.

     'sizehint' is the recommended minimum size for the returned buffer.
     It is acceptable to return smaller or larger buffers than what
     'sizehint' suggests.  When set to -1, the buffer size can be
     arbitrary.  It is an error to return a buffer with a zero size.

     ‘get_buffer()’ must return an object implementing the *note buffer
     protocol: 260.

 -- Metodo: BufferedProtocol.buffer_updated (nbytes)

     Called when the buffer was updated with the received data.

     'nbytes' is the total number of bytes that were written to the
     buffer.

 -- Metodo: BufferedProtocol.eof_received ()

     See the documentation of the *note protocol.eof_received(): 38d8.
     method.

*note get_buffer(): 38da. can be called an arbitrary number of times
during a connection.  However, *note protocol.eof_received(): 38d8. is
called at most once and, if called, *note get_buffer(): 38da. and *note
buffer_updated(): 38db. won’t be called after it.

State machine:

     start -> connection_made
         [-> get_buffer
             [-> buffer_updated]?
         ]*
         [-> eof_received]?
     -> connection_lost -> end


File: python.info,  Node: Datagram Protocols,  Next: Subprocess Protocols,  Prev: Buffered Streaming Protocols,  Up: Protocols<2>

5.19.1.95 Datagram Protocols
............................

Datagram Protocol instances should be constructed by protocol factories
passed to the *note loop.create_datagram_endpoint(): 93d. method.

 -- Metodo: DatagramProtocol.datagram_received (data, addr)

     Called when a datagram is received.  'data' is a bytes object
     containing the incoming data.  'addr' is the address of the peer
     sending the data; the exact format depends on the transport.

 -- Metodo: DatagramProtocol.error_received (exc)

     Called when a previous send or receive operation raises an *note
     OSError: 2c0.  'exc' is the *note OSError: 2c0. instance.

     This method is called in rare conditions, when the transport (e.g.
     UDP) detects that a datagram could not be delivered to its
     recipient.  In many conditions though, undeliverable datagrams will
     be silently dropped.

     Nota: On BSD systems (macOS, FreeBSD, etc.)  flow control is not
     supported for datagram protocols, because there is no reliable way
     to detect send failures caused by writing too many packets.

     The socket always appears “ready” and excess packets are dropped.
     An *note OSError: 2c0. with ‘errno’ set to *note errno.ENOBUFS:
     1b59. may or may not be raised; if it is raised, it will be
     reported to *note DatagramProtocol.error_received(): 38df. but
     otherwise ignored.


File: python.info,  Node: Subprocess Protocols,  Prev: Datagram Protocols,  Up: Protocols<2>

5.19.1.96 Subprocess Protocols
..............................

Subprocess Protocol instances should be constructed by protocol
factories passed to the *note loop.subprocess_exec(): 3829. and *note
loop.subprocess_shell(): 382a. methods.

 -- Metodo: SubprocessProtocol.pipe_data_received (fd, data)

     Called when the child process writes data into its stdout or stderr
     pipe.

     'fd' is the integer file descriptor of the pipe.

     'data' is a non-empty bytes object containing the received data.

 -- Metodo: SubprocessProtocol.pipe_connection_lost (fd, exc)

     Called when one of the pipes communicating with the child process
     is closed.

     'fd' is the integer file descriptor that was closed.

 -- Metodo: SubprocessProtocol.process_exited ()

     Called when the child process has exited.

     It can be called before *note pipe_data_received(): 1b38. and *note
     pipe_connection_lost(): 38e1. methods.


File: python.info,  Node: Examples<20>,  Prev: Protocols<2>,  Up: Transports and Protocols

5.19.1.97 Examples
..................

* Menu:

* TCP Echo Server::
* TCP Echo Client::
* UDP Echo Server::
* UDP Echo Client::
* Connecting Existing Sockets::
* loop.subprocess_exec() and SubprocessProtocol: loop subprocess_exec and SubprocessProtocol.


File: python.info,  Node: TCP Echo Server,  Next: TCP Echo Client,  Up: Examples<20>

5.19.1.98 TCP Echo Server
.........................

Create a TCP echo server using the *note loop.create_server(): d0b.
method, send back received data, and close the connection:

     import asyncio


     class EchoServerProtocol(asyncio.Protocol):
         def connection_made(self, transport):
             peername = transport.get_extra_info('peername')
             print('Connection from {}'.format(peername))
             self.transport = transport

         def data_received(self, data):
             message = data.decode()
             print('Data received: {!r}'.format(message))

             print('Send: {!r}'.format(message))
             self.transport.write(data)

             print('Close the client socket')
             self.transport.close()


     async def main():
         # Get a reference to the event loop as we plan to use
         # low-level APIs.
         loop = asyncio.get_running_loop()

         server = await loop.create_server(
             EchoServerProtocol,
             '127.0.0.1', 8888)

         async with server:
             await server.serve_forever()


     asyncio.run(main())

Vedi anche
..........

The *note TCP echo server using streams: 37f8. example uses the
high-level *note asyncio.start_server(): d11. function.


File: python.info,  Node: TCP Echo Client,  Next: UDP Echo Server,  Prev: TCP Echo Server,  Up: Examples<20>

5.19.1.99 TCP Echo Client
.........................

A TCP echo client using the *note loop.create_connection(): 819. method,
sends data, and waits until the connection is closed:

     import asyncio


     class EchoClientProtocol(asyncio.Protocol):
         def __init__(self, message, on_con_lost):
             self.message = message
             self.on_con_lost = on_con_lost

         def connection_made(self, transport):
             transport.write(self.message.encode())
             print('Data sent: {!r}'.format(self.message))

         def data_received(self, data):
             print('Data received: {!r}'.format(data.decode()))

         def connection_lost(self, exc):
             print('The server closed the connection')
             self.on_con_lost.set_result(True)


     async def main():
         # Get a reference to the event loop as we plan to use
         # low-level APIs.
         loop = asyncio.get_running_loop()

         on_con_lost = loop.create_future()
         message = 'Hello World!'

         transport, protocol = await loop.create_connection(
             lambda: EchoClientProtocol(message, on_con_lost),
             '127.0.0.1', 8888)

         # Wait until the protocol signals that the connection
         # is lost and close the transport.
         try:
             await on_con_lost
         finally:
             transport.close()


     asyncio.run(main())

Vedi anche
..........

The *note TCP echo client using streams: 37f5. example uses the
high-level *note asyncio.open_connection(): d10. function.


File: python.info,  Node: UDP Echo Server,  Next: UDP Echo Client,  Prev: TCP Echo Client,  Up: Examples<20>

5.19.1.100 UDP Echo Server
..........................

A UDP echo server, using the *note loop.create_datagram_endpoint(): 93d.
method, sends back received data:

     import asyncio


     class EchoServerProtocol:
         def connection_made(self, transport):
             self.transport = transport

         def datagram_received(self, data, addr):
             message = data.decode()
             print('Received %r from %s' % (message, addr))
             print('Send %r to %s' % (message, addr))
             self.transport.sendto(data, addr)


     async def main():
         print("Starting UDP server")

         # Get a reference to the event loop as we plan to use
         # low-level APIs.
         loop = asyncio.get_running_loop()

         # One protocol instance will be created to serve all
         # client requests.
         transport, protocol = await loop.create_datagram_endpoint(
             EchoServerProtocol,
             local_addr=('127.0.0.1', 9999))

         try:
             await asyncio.sleep(3600)  # Serve for 1 hour.
         finally:
             transport.close()


     asyncio.run(main())


File: python.info,  Node: UDP Echo Client,  Next: Connecting Existing Sockets,  Prev: UDP Echo Server,  Up: Examples<20>

5.19.1.101 UDP Echo Client
..........................

A UDP echo client, using the *note loop.create_datagram_endpoint(): 93d.
method, sends data and closes the transport when it receives the answer:

     import asyncio


     class EchoClientProtocol:
         def __init__(self, message, on_con_lost):
             self.message = message
             self.on_con_lost = on_con_lost
             self.transport = None

         def connection_made(self, transport):
             self.transport = transport
             print('Send:', self.message)
             self.transport.sendto(self.message.encode())

         def datagram_received(self, data, addr):
             print("Received:", data.decode())

             print("Close the socket")
             self.transport.close()

         def error_received(self, exc):
             print('Error received:', exc)

         def connection_lost(self, exc):
             print("Connection closed")
             self.on_con_lost.set_result(True)


     async def main():
         # Get a reference to the event loop as we plan to use
         # low-level APIs.
         loop = asyncio.get_running_loop()

         on_con_lost = loop.create_future()
         message = "Hello World!"

         transport, protocol = await loop.create_datagram_endpoint(
             lambda: EchoClientProtocol(message, on_con_lost),
             remote_addr=('127.0.0.1', 9999))

         try:
             await on_con_lost
         finally:
             transport.close()


     asyncio.run(main())


File: python.info,  Node: Connecting Existing Sockets,  Next: loop subprocess_exec and SubprocessProtocol,  Prev: UDP Echo Client,  Up: Examples<20>

5.19.1.102 Connecting Existing Sockets
......................................

Wait until a socket receives data using the *note
loop.create_connection(): 819. method with a protocol:

     import asyncio
     import socket


     class MyProtocol(asyncio.Protocol):

         def __init__(self, on_con_lost):
             self.transport = None
             self.on_con_lost = on_con_lost

         def connection_made(self, transport):
             self.transport = transport

         def data_received(self, data):
             print("Received:", data.decode())

             # We are done: close the transport;
             # connection_lost() will be called automatically.
             self.transport.close()

         def connection_lost(self, exc):
             # The socket has been closed
             self.on_con_lost.set_result(True)


     async def main():
         # Get a reference to the event loop as we plan to use
         # low-level APIs.
         loop = asyncio.get_running_loop()
         on_con_lost = loop.create_future()

         # Create a pair of connected sockets
         rsock, wsock = socket.socketpair()

         # Register the socket to wait for data.
         transport, protocol = await loop.create_connection(
             lambda: MyProtocol(on_con_lost), sock=rsock)

         # Simulate the reception of data from the network.
         loop.call_soon(wsock.send, 'abc'.encode())

         try:
             await protocol.on_con_lost
         finally:
             transport.close()
             wsock.close()

     asyncio.run(main())

Vedi anche
..........

The *note watch a file descriptor for read events: 37ff. example uses
the low-level *note loop.add_reader(): 3800. method to register an FD.

The *note register an open socket to wait for data using streams: 37fc.
example uses high-level streams created by the *note open_connection():
d10. function in a coroutine.


File: python.info,  Node: loop subprocess_exec and SubprocessProtocol,  Prev: Connecting Existing Sockets,  Up: Examples<20>

5.19.1.103 loop.subprocess_exec() and SubprocessProtocol
........................................................

An example of a subprocess protocol used to get the output of a
subprocess and to wait for the subprocess exit.

The subprocess is created by the *note loop.subprocess_exec(): 3829.
method:

     import asyncio
     import sys

     class DateProtocol(asyncio.SubprocessProtocol):
         def __init__(self, exit_future):
             self.exit_future = exit_future
             self.output = bytearray()
             self.pipe_closed = False
             self.exited = False

         def pipe_connection_lost(self, fd, exc):
             self.pipe_closed = True
             self.check_for_exit()

         def pipe_data_received(self, fd, data):
             self.output.extend(data)

         def process_exited(self):
             self.exited = True
             # process_exited() method can be called before
             # pipe_connection_lost() method: wait until both methods are
             # called.
             self.check_for_exit()

         def check_for_exit(self):
             if self.pipe_closed and self.exited:
                 self.exit_future.set_result(True)

     async def get_date():
         # Get a reference to the event loop as we plan to use
         # low-level APIs.
         loop = asyncio.get_running_loop()

         code = 'import datetime; print(datetime.datetime.now())'
         exit_future = asyncio.Future(loop=loop)

         # Create the subprocess controlled by DateProtocol;
         # redirect the standard output into a pipe.
         transport, protocol = await loop.subprocess_exec(
             lambda: DateProtocol(exit_future),
             sys.executable, '-c', code,
             stdin=None, stderr=None)

         # Wait for the subprocess exit using the process_exited()
         # method of the protocol.
         await exit_future

         # Close the stdout pipe.
         transport.close()

         # Read the output which was collected by the
         # pipe_data_received() method of the protocol.
         data = bytes(protocol.output)
         return data.decode('ascii').rstrip()

     date = asyncio.run(get_date())
     print(f"Current date: {date}")

See also the *note same example: 383d. written using high-level APIs.


File: python.info,  Node: Policies,  Next: Platform Support,  Prev: Transports and Protocols,  Up: asyncio — Asynchronous I/O

5.19.1.104 Policies
...................

     Avvertimento: Policies are deprecated and will be removed in Python
     3.16.  Users are encouraged to use the *note asyncio.run(): 2f3.
     function or the *note asyncio.Runner: 2f5. with 'loop_factory' to
     use the desired loop implementation.

An event loop policy is a global object used to get and set the current
*note event loop: f78, as well as create new event loops.  The default
policy can be *note replaced: 38eb. with *note built-in alternatives:
38ec. to use different event loop implementations, or substituted by a
*note custom policy: 38ed. that can override these behaviors.

The *note policy object: 38ee. gets and sets a separate event loop per
'context'.  This is per-thread by default, though custom policies could
define 'context' differently.

Custom event loop policies can control the behavior of *note
get_event_loop(): 2f2, *note set_event_loop(): 1b3d, and *note
new_event_loop(): 37ac.

Policy objects should implement the APIs defined in the *note
AbstractEventLoopPolicy: 30e. abstract base class.

* Menu:

* Getting and Setting the Policy::
* Policy Objects::
* Custom Policies::


File: python.info,  Node: Getting and Setting the Policy,  Next: Policy Objects,  Up: Policies

5.19.1.105 Getting and Setting the Policy
.........................................

The following functions can be used to get and set the policy for the
current process:

 -- Funzione: asyncio.get_event_loop_policy ()

     Return the current process-wide policy.

     Deprecato dalla versione 3.14: The *note get_event_loop_policy():
     312. function is deprecated and will be removed in Python 3.16.

 -- Funzione: asyncio.set_event_loop_policy (policy)

     Set the current process-wide policy to 'policy'.

     If 'policy' is set to ‘None’, the default policy is restored.

     Deprecato dalla versione 3.14: The *note set_event_loop_policy():
     313. function is deprecated and will be removed in Python 3.16.


File: python.info,  Node: Policy Objects,  Next: Custom Policies,  Prev: Getting and Setting the Policy,  Up: Policies

5.19.1.106 Policy Objects
.........................

The abstract event loop policy base class is defined as follows:

 -- Classe: asyncio.AbstractEventLoopPolicy

     An abstract base class for asyncio policies.

      -- Metodo: get_event_loop ()

          Get the event loop for the current context.

          Return an event loop object implementing the *note
          AbstractEventLoop: b5a. interface.

          This method should never return ‘None’.

          Cambiato nella versione 3.6.

      -- Metodo: set_event_loop (loop)

          Set the event loop for the current context to 'loop'.

      -- Metodo: new_event_loop ()

          Create and return a new event loop object.

          This method should never return ‘None’.

     Deprecato dalla versione 3.14: The *note AbstractEventLoopPolicy:
     30e. class is deprecated and will be removed in Python 3.16.

asyncio ships with the following built-in policies:

 -- Classe: asyncio.DefaultEventLoopPolicy

     The default asyncio policy.  Uses *note SelectorEventLoop: 314. on
     Unix and *note ProactorEventLoop: 81e. on Windows.

     There is no need to install the default policy manually.  asyncio
     is configured to use the default policy automatically.

     Cambiato nella versione 3.8: On Windows, *note ProactorEventLoop:
     81e. is now used by default.

     Cambiato nella versione 3.14: The *note get_event_loop(): 2f2.
     method of the default asyncio policy now raises a *note
     RuntimeError: 244. if there is no set event loop.

     Deprecato dalla versione 3.14: The *note DefaultEventLoopPolicy:
     30f. class is deprecated and will be removed in Python 3.16.

 -- Classe: asyncio.WindowsSelectorEventLoopPolicy

     An alternative event loop policy that uses the *note
     SelectorEventLoop: 314. event loop implementation.

     *note Availability: 2128.: Windows.

     Deprecato dalla versione 3.14: The *note
     WindowsSelectorEventLoopPolicy: 310. class is deprecated and will
     be removed in Python 3.16.

 -- Classe: asyncio.WindowsProactorEventLoopPolicy

     An alternative event loop policy that uses the *note
     ProactorEventLoop: 81e. event loop implementation.

     *note Availability: 2128.: Windows.

     Deprecato dalla versione 3.14: The *note
     WindowsProactorEventLoopPolicy: 311. class is deprecated and will
     be removed in Python 3.16.


File: python.info,  Node: Custom Policies,  Prev: Policy Objects,  Up: Policies

5.19.1.107 Custom Policies
..........................

To implement a new event loop policy, it is recommended to subclass
*note DefaultEventLoopPolicy: 30f. and override the methods for which
custom behavior is wanted, e.g.:

     class MyEventLoopPolicy(asyncio.DefaultEventLoopPolicy):

         def get_event_loop(self):
             """Get the event loop.

             This may be None or an instance of EventLoop.
             """
             loop = super().get_event_loop()
             # Do something with loop ...
             return loop

     asyncio.set_event_loop_policy(MyEventLoopPolicy())


File: python.info,  Node: Platform Support,  Next: Extending,  Prev: Policies,  Up: asyncio — Asynchronous I/O

5.19.1.108 Platform Support
...........................

The *note asyncio: b. module is designed to be portable, but some
platforms have subtle differences and limitations due to the platforms”
underlying architecture and capabilities.

* Menu:

* All Platforms::
* Windows: Windows<83>.
* macOS: macOS<51>.


File: python.info,  Node: All Platforms,  Next: Windows<83>,  Up: Platform Support

5.19.1.109 All Platforms
........................

   * *note loop.add_reader(): 3800. and *note loop.add_writer(): 3886.
     cannot be used to monitor file I/O.


File: python.info,  Node: Windows<83>,  Next: macOS<51>,  Prev: All Platforms,  Up: Platform Support

5.19.1.110 Windows
..................

'Source code:' Lib/asyncio/proactor_events.py(1),
Lib/asyncio/windows_events.py(2), Lib/asyncio/windows_utils.py(3)

__________________________________________________________________

Cambiato nella versione 3.8: On Windows, *note ProactorEventLoop: 81e.
is now the default event loop.

All event loops on Windows do not support the following methods:

   * *note loop.create_unix_connection(): 37e5. and *note
     loop.create_unix_server(): 4cb. are not supported.  The *note
     socket.AF_UNIX: 1b98. socket family is specific to Unix.

   * *note loop.add_signal_handler(): 388f. and *note
     loop.remove_signal_handler(): 3890. are not supported.

*note SelectorEventLoop: 314. has the following limitations:

   * *note SelectSelector: 38fa. is used to wait on socket events: it
     supports sockets and is limited to 512 sockets.

   * *note loop.add_reader(): 3800. and *note loop.add_writer(): 3886.
     only accept socket handles (e.g.  pipe file descriptors are not
     supported).

   * Pipes are not supported, so the *note loop.connect_read_pipe():
     382c. and *note loop.connect_write_pipe(): 382d. methods are not
     implemented.

   * *note Subprocesses: 37a0. are not supported, i.e.  *note
     loop.subprocess_exec(): 3829. and *note loop.subprocess_shell():
     382a. methods are not implemented.

*note ProactorEventLoop: 81e. has the following limitations:

   * The *note loop.add_reader(): 3800. and *note loop.add_writer():
     3886. methods are not supported.

The resolution of the monotonic clock on Windows is usually around 15.6
milliseconds.  The best resolution is 0.5 milliseconds.  The resolution
depends on the hardware (availability of HPET(4)) and on the Windows
configuration.

* Menu:

* Subprocess Support on Windows::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/proactor_events.py

   (2) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/windows_events.py

   (3) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/windows_utils.py

   (4) https://en.wikipedia.org/wiki/High_Precision_Event_Timer


File: python.info,  Node: Subprocess Support on Windows,  Up: Windows<83>

5.19.1.111 Subprocess Support on Windows
........................................

On Windows, the default event loop *note ProactorEventLoop: 81e.
supports subprocesses, whereas *note SelectorEventLoop: 314. does not.


File: python.info,  Node: macOS<51>,  Prev: Windows<83>,  Up: Platform Support

5.19.1.112 macOS
................

Modern macOS versions are fully supported.

macOS <= 10.8
.............

On macOS 10.6, 10.7 and 10.8, the default event loop uses *note
selectors.KqueueSelector: 38fd, which does not support character devices
on these versions.  The *note SelectorEventLoop: 314. can be manually
configured to use *note SelectSelector: 38fa. or *note PollSelector:
dd3. to support character devices on these older versions of macOS.
Example:

     import asyncio
     import selectors

     selector = selectors.SelectSelector()
     loop = asyncio.SelectorEventLoop(selector)
     asyncio.set_event_loop(loop)


File: python.info,  Node: Extending,  Next: High-level API Index,  Prev: Platform Support,  Up: asyncio — Asynchronous I/O

5.19.1.113 Extending
....................

The main direction for *note asyncio: b. extending is writing custom
'event loop' classes.  Asyncio has helpers that could be used to
simplify this task.

     Nota: Third-parties should reuse existing asyncio code with
     caution, a new Python version is free to break backward
     compatibility in 'internal' part of API.

* Menu:

* Writing a Custom Event Loop::
* Future and Task private constructors::
* Task lifetime support::


File: python.info,  Node: Writing a Custom Event Loop,  Next: Future and Task private constructors,  Up: Extending

5.19.1.114 Writing a Custom Event Loop
......................................

*note asyncio.AbstractEventLoop: b5a. declares very many methods.
Implementing all them from scratch is a tedious job.

A loop can get many common methods implementation for free by inheriting
from ‘asyncio.BaseEventLoop’.

In turn, the successor should implement a bunch of 'private' methods
declared but not implemented in ‘asyncio.BaseEventLoop’.

For example, ‘loop.create_connection()’ checks arguments, resolves DNS
addresses, and calls ‘loop._make_socket_transport()’ that should be
implemented by inherited class.  The ‘_make_socket_transport()’ method
is not documented and is considered as an 'internal' API.


File: python.info,  Node: Future and Task private constructors,  Next: Task lifetime support,  Prev: Writing a Custom Event Loop,  Up: Extending

5.19.1.115 Future and Task private constructors
...............................................

*note asyncio.Future: dc8. and *note asyncio.Task: 1c7. should be never
created directly, please use corresponding *note loop.create_future():
e76. and *note loop.create_task(): 1ca, or *note asyncio.create_task():
1c9. factories instead.

However, third-party 'event loops' may 'reuse' built-in future and task
implementations for the sake of getting a complex and highly optimized
code for free.

For this purpose the following, 'private' constructors are listed:

 -- Metodo: Future.__init__ (*, loop=None)

     Create a built-in future instance.

     'loop' is an optional event loop instance.

 -- Metodo: Task.__init__ (coro, *, loop=None, name=None, context=None)

     Create a built-in task instance.

     'loop' is an optional event loop instance.  The rest of arguments
     are described in *note loop.create_task(): 1ca. description.

     Cambiato nella versione 3.11: 'context' argument is added.


File: python.info,  Node: Task lifetime support,  Prev: Future and Task private constructors,  Up: Extending

5.19.1.116 Task lifetime support
................................

A third party task implementation should call the following functions to
keep a task visible by *note asyncio.all_tasks(): b51. and *note
asyncio.current_task(): 6a6.:

 -- Funzione: asyncio._register_task (task)

     Register a new 'task' as managed by 'asyncio'.

     Call the function from a task constructor.

 -- Funzione: asyncio._unregister_task (task)

     Unregister a 'task' from 'asyncio' internal structures.

     The function should be called when a task is about to finish.

 -- Funzione: asyncio._enter_task (loop, task)

     Switch the current task to the 'task' argument.

     Call the function just before executing a portion of embedded
     'coroutine' (*note coroutine.send(): 23fc. or *note
     coroutine.throw(): 71c.).

 -- Funzione: asyncio._leave_task (loop, task)

     Switch the current task back from 'task' to ‘None’.

     Call the function just after *note coroutine.send(): 23fc. or *note
     coroutine.throw(): 71c. execution.


File: python.info,  Node: High-level API Index,  Next: Low-level API Index,  Prev: Extending,  Up: asyncio — Asynchronous I/O

5.19.1.117 High-level API Index
...............................

This page lists all high-level async/await enabled asyncio APIs.

* Menu:

* Tasks::
* Queues: Queues<2>.
* Subprocesses: Subprocesses<2>.
* Streams: Streams<2>.
* Synchronization::
* Exceptions: Exceptions<16>.


File: python.info,  Node: Tasks,  Next: Queues<2>,  Up: High-level API Index

5.19.1.118 Tasks
................

Utilities to run asyncio programs, create Tasks, and await on multiple
things with timeouts.

*note run(): 2f3.                                      Create event loop, run a coroutine, close the loop.
                                                       
                                                       
*note Runner: 2f5.                                     A context manager that simplifies multiple async
                                                       function calls.
                                                       
                                                       
*note Task: 1c7.                                       Task object.
                                                       
                                                       
*note TaskGroup: 4d2.                                  A context manager that holds a group of tasks.
                                                       Provides a convenient and reliable way to wait for
                                                       all tasks in the group to finish.
                                                       
                                                       
*note create_task(): 1c9.                              Start an asyncio Task, then returns it.
                                                       
                                                       
*note current_task(): 6a6.                             Return the current Task.
                                                       
                                                       
*note all_tasks(): b51.                                Return all tasks that are not yet finished for an
                                                       event loop.
                                                       
                                                       
‘await’ *note sleep(): c66.                            Sleep for a number of seconds.
                                                       
                                                       
‘await’ *note gather(): 814.                           Schedule and wait for things concurrently.
                                                       
                                                       
‘await’ *note wait_for(): 816.                         Run with a timeout.
                                                       
                                                       
‘await’ *note shield(): c67.                           Shield from cancellation.
                                                       
                                                       
‘await’ *note wait(): 6a8.                             Monitor for completion.
                                                       
                                                       
*note timeout(): 815.                                  Run with a timeout.  Useful in cases when ‘wait_for’
                                                       is not suitable.
                                                       
                                                       
*note to_thread(): ae7.                                Asynchronously run a function in a separate OS
                                                       thread.
                                                       
                                                       
*note run_coroutine_threadsafe(): a84.                 Schedule a coroutine from another OS thread.
                                                       
                                                       
‘for in’ *note as_completed(): 4c7.                    Monitor for completion with a ‘for’ loop.
                                                       

Examples
........

   * *note Using asyncio.gather() to run things in parallel: 37bf.

   * *note Using asyncio.wait_for() to enforce a timeout: 37c7.

   * *note Cancellation: 37dc.

   * *note Using asyncio.sleep(): 37bd.

   * See also the main *note Tasks documentation page: 379e.


File: python.info,  Node: Queues<2>,  Next: Subprocesses<2>,  Prev: Tasks,  Up: High-level API Index

5.19.1.119 Queues
.................

Queues should be used to distribute work amongst multiple asyncio Tasks,
implement connection pools, and pub/sub patterns.

*note Queue: c6c.                                      A FIFO queue.
                                                       
                                                       
*note PriorityQueue: 384f.                             A priority queue.
                                                       
                                                       
*note LifoQueue: 3851.                                 A LIFO queue.
                                                       

Examples
........

   * *note Using asyncio.Queue to distribute workload between several
     Tasks: 3853.

   * See also the *note Queues documentation page: 37a1.


File: python.info,  Node: Subprocesses<2>,  Next: Streams<2>,  Prev: Queues<2>,  Up: High-level API Index

5.19.1.120 Subprocesses
.......................

Utilities to spawn subprocesses and run shell commands.

‘await’ *note create_subprocess_exec(): c6d.           Create a subprocess.
                                                       
                                                       
‘await’ *note create_subprocess_shell(): c6e.          Run a shell command.
                                                       

Examples
........

   * *note Executing a shell command: 3823.

   * See also the *note subprocess APIs: 37a0. documentation.


File: python.info,  Node: Streams<2>,  Next: Synchronization,  Prev: Subprocesses<2>,  Up: High-level API Index

5.19.1.121 Streams
..................

High-level APIs to work with network IO.

‘await’ *note open_connection(): d10.                  Establish a TCP connection.
                                                       
                                                       
‘await’ *note open_unix_connection(): 37e4.            Establish a Unix socket connection.
                                                       
                                                       
‘await’ *note start_server(): d11.                     Start a TCP server.
                                                       
                                                       
‘await’ *note start_unix_server(): 37e6.               Start a Unix socket server.
                                                       
                                                       
*note StreamReader: 1c65.                              High-level async/await object to receive network
                                                       data.
                                                       
                                                       
*note StreamWriter: 1a58.                              High-level async/await object to send network data.
                                                       

Examples
........

   * *note Example TCP client: 37e0.

   * See also the *note streams APIs: 379f. documentation.


File: python.info,  Node: Synchronization,  Next: Exceptions<16>,  Prev: Streams<2>,  Up: High-level API Index

5.19.1.122 Synchronization
..........................

Threading-like synchronization primitives that can be used in Tasks.

*note Lock: c68.                                       A mutex lock.
                                                       
                                                       
*note Event: 2f4.                                      An event object.
                                                       
                                                       
*note Condition: c69.                                  A condition object.
                                                       
                                                       
*note Semaphore: c6a.                                  A semaphore.
                                                       
                                                       
*note BoundedSemaphore: c6b.                           A bounded semaphore.
                                                       
                                                       
*note Barrier: 817.                                    A barrier object.
                                                       

Examples
........

   * *note Using asyncio.Event: 380c.

   * *note Using asyncio.Barrier: 381a.

   * See also the documentation of asyncio *note synchronization
     primitives: 37a2.


File: python.info,  Node: Exceptions<16>,  Prev: Synchronization,  Up: High-level API Index

5.19.1.123 Exceptions
.....................

*note asyncio.CancelledError: 4d5.                     Raised when a Task is cancelled.  See also
                                                       *note Task.cancel(): 4d4.
                                                       
                                                       
*note asyncio.BrokenBarrierError: 818.                 Raised when a Barrier is broken.  See also
                                                       *note Barrier.wait(): 3819.
                                                       

Examples
........

   * *note Handling CancelledError to run code on cancellation request:
     37dc.

   * See also the full list of *note asyncio-specific exceptions: 3855.


File: python.info,  Node: Low-level API Index,  Next: Developing with asyncio,  Prev: High-level API Index,  Up: asyncio — Asynchronous I/O

5.19.1.124 Low-level API Index
..............................

This page lists all low-level asyncio APIs.

* Menu:

* Obtaining the Event Loop::
* Event Loop Methods: Event Loop Methods<2>.
* Transports: Transports<2>.
* Protocols: Protocols<3>.
* Event Loop Policies::


File: python.info,  Node: Obtaining the Event Loop,  Next: Event Loop Methods<2>,  Up: Low-level API Index

5.19.1.125 Obtaining the Event Loop
...................................

*note asyncio.get_running_loop(): d03.                 The 'preferred' function to get the running event
                                                       loop.
                                                       
                                                       
*note asyncio.get_event_loop(): 2f2.                   Get an event loop instance (running or current via
                                                       the current policy).
                                                       
                                                       
*note asyncio.set_event_loop(): 1b3d.                  Set the event loop as current via the current
                                                       policy.
                                                       
                                                       
*note asyncio.new_event_loop(): 37ac.                  Create a new event loop.
                                                       

Examples
........

   * *note Using asyncio.get_running_loop(): 38b1.


File: python.info,  Node: Event Loop Methods<2>,  Next: Transports<2>,  Prev: Obtaining the Event Loop,  Up: Low-level API Index

5.19.1.126 Event Loop Methods
.............................

See also the main documentation section about the *note Event Loop
Methods: 386c.

Lifecycle
.........

*note loop.run_until_complete(): e74.                  Run a Future/Task/awaitable until complete.
                                                       
                                                       
*note loop.run_forever(): 386e.                        Run the event loop forever.
                                                       
                                                       
*note loop.stop(): e79.                                Stop the event loop.
                                                       
                                                       
*note loop.close(): 3870.                              Close the event loop.
                                                       
                                                       
*note loop.is_running(): 386f.                         Return ‘True’ if the event loop is running.
                                                       
                                                       
*note loop.is_closed(): fc5.                           Return ‘True’ if the event loop is closed.
                                                       
                                                       
‘await’ *note loop.shutdown_asyncgens(): e7b.          Close asynchronous generators.
                                                       

Debugging
.........

*note loop.set_debug(): fc3.                           Enable or disable the debug mode.
                                                       
                                                       
*note loop.get_debug(): fc4.                           Get the current debug mode.
                                                       

Scheduling Callbacks
....................

*note loop.call_soon(): cfc.                           Invoke a callback soon.
                                                       
                                                       
*note loop.call_soon_threadsafe(): cfd.                A thread-safe variant of
                                                       *note loop.call_soon(): cfc.
                                                       
                                                       
*note loop.call_later(): cfe.                          Invoke a callback 'after' the given time.
                                                       
                                                       
*note loop.call_at(): cff.                             Invoke a callback 'at' the given time.
                                                       

Thread/Interpreter/Process Pool
...............................

‘await’ *note loop.run_in_executor(): ae8.             Run a CPU-bound or other blocking function in a
                                                       *note concurrent.futures: 24. executor.
                                                       
                                                       
*note loop.set_default_executor(): 94b.                Set the default executor for
                                                       *note loop.run_in_executor(): ae8.
                                                       

Tasks and Futures
.................

*note loop.create_future(): e76.                       Create a *note Future: dc8. object.
                                                       
                                                       
*note loop.create_task(): 1ca.                         Schedule coroutine as a *note Task: 1c7.
                                                       
                                                       
*note loop.set_task_factory(): 1c8.                    Set a factory used by *note loop.create_task(): 1ca.
                                                       to create *note Tasks: 1c7.
                                                       
                                                       
*note loop.get_task_factory(): fc7.                    Get the factory *note loop.create_task(): 1ca. uses
                                                       to create *note Tasks: 1c7.
                                                       

DNS
...

‘await’ *note loop.getaddrinfo(): e10.                 Asynchronous version of
                                                       *note socket.getaddrinfo(): 1aab.
                                                       
                                                       
‘await’ *note loop.getnameinfo(): e11.                 Asynchronous version of
                                                       *note socket.getnameinfo(): 1a22.
                                                       

Networking and IPC
..................

‘await’ *note loop.create_connection(): 819.           Open a TCP connection.
                                                       
                                                       
‘await’ *note loop.create_server(): d0b.               Create a TCP server.
                                                       
                                                       
‘await’ *note loop.create_unix_connection(): 37e5.     Open a Unix socket connection.
                                                       
                                                       
‘await’ *note loop.create_unix_server(): 4cb.          Create a Unix socket server.
                                                       
                                                       
‘await’ *note loop.connect_accepted_socket(): 9e0.     Wrap a *note socket: fa3. into a ‘(transport,
                                                       protocol)’ pair.
                                                       
                                                       
‘await’ *note loop.create_datagram_endpoint(): 93d.    Open a datagram (UDP) connection.
                                                       
                                                       
‘await’ *note loop.sendfile(): 3882.                   Send a file over a transport.
                                                       
                                                       
‘await’ *note loop.start_tls(): d01.                   Upgrade an existing connection to TLS.
                                                       
                                                       
‘await’ *note loop.connect_read_pipe(): 382c.          Wrap a read end of a pipe into a ‘(transport,
                                                       protocol)’ pair.
                                                       
                                                       
‘await’ *note loop.connect_write_pipe(): 382d.         Wrap a write end of a pipe into a ‘(transport,
                                                       protocol)’ pair.
                                                       

Sockets
.......

‘await’ *note loop.sock_recv(): e0d.                   Receive data from the *note socket: fa3.
                                                       
                                                       
‘await’ *note loop.sock_recv_into(): d02.              Receive data from the *note socket: fa3. into a
                                                       buffer.
                                                       
                                                       
‘await’ *note loop.sock_recvfrom(): 81c.               Receive a datagram from the *note socket: fa3.
                                                       
                                                       
‘await’ *note loop.sock_recvfrom_into(): 81d.          Receive a datagram from the *note socket: fa3. into
                                                       a buffer.
                                                       
                                                       
‘await’ *note loop.sock_sendall(): e0e.                Send data to the *note socket: fa3.
                                                       
                                                       
‘await’ *note loop.sock_sendto(): 81b.                 Send a datagram via the *note socket: fa3. to the
                                                       given address.
                                                       
                                                       
‘await’ *note loop.sock_connect(): fca.                Connect the *note socket: fa3.
                                                       
                                                       
‘await’ *note loop.sock_accept(): e0f.                 Accept a *note socket: fa3. connection.
                                                       
                                                       
‘await’ *note loop.sock_sendfile(): d06.               Send a file over the *note socket: fa3.
                                                       
                                                       
*note loop.add_reader(): 3800.                         Start watching a file descriptor for read
                                                       availability.
                                                       
                                                       
*note loop.remove_reader(): 3885.                      Stop watching a file descriptor for read
                                                       availability.
                                                       
                                                       
*note loop.add_writer(): 3886.                         Start watching a file descriptor for write
                                                       availability.
                                                       
                                                       
*note loop.remove_writer(): 3887.                      Stop watching a file descriptor for write
                                                       availability.
                                                       

Unix Signals
............

*note loop.add_signal_handler(): 388f.                 Add a handler for a *note signal: cb.
                                                       
                                                       
*note loop.remove_signal_handler(): 3890.              Remove a handler for a *note signal: cb.
                                                       

Subprocesses
............

*note loop.subprocess_exec(): 3829.                    Spawn a subprocess.
                                                       
                                                       
*note loop.subprocess_shell(): 382a.                   Spawn a subprocess from a shell command.
                                                       

Error Handling
..............

*note loop.call_exception_handler(): 3894.             Call the exception handler.
                                                       
                                                       
*note loop.set_exception_handler(): 3893.              Set a new exception handler.
                                                       
                                                       
*note loop.get_exception_handler(): e77.               Get the current exception handler.
                                                       
                                                       
*note loop.default_exception_handler(): 3895.          The default exception handler implementation.
                                                       

Examples
........

   * *note Using asyncio.new_event_loop() and loop.run_forever(): 38a0.

   * *note Using loop.call_later(): 38a2.

   * Using ‘loop.create_connection()’ to implement *note an echo-client:
     37f7.

   * Using ‘loop.create_connection()’ to *note connect a socket: 37fe.

   * *note Using add_reader() to watch an FD for read events: 37ff.

   * *note Using loop.add_signal_handler(): 38a5.

   * *note Using loop.subprocess_exec(): 383e.


File: python.info,  Node: Transports<2>,  Next: Protocols<3>,  Prev: Event Loop Methods<2>,  Up: Low-level API Index

5.19.1.127 Transports
.....................

All transports implement the following methods:

*note transport.close(): 387c.                         Close the transport.
                                                       
                                                       
*note transport.is_closing(): e75.                     Return ‘True’ if the transport is closing or is
                                                       closed.
                                                       
                                                       
*note transport.get_extra_info(): c95.                 Request for information about the transport.
                                                       
                                                       
*note transport.set_protocol(): 38c1.                  Set a new protocol.
                                                       
                                                       
*note transport.get_protocol(): 38c2.                  Return the current protocol.
                                                       

Transports that can receive data (TCP and Unix connections, pipes, etc).
Returned from methods like *note loop.create_connection(): 819, *note
loop.create_unix_connection(): 37e5, *note loop.connect_read_pipe():
382c, etc:

Read Transports
...............

*note transport.is_reading(): d13.                     Return ‘True’ if the transport is receiving.
                                                       
                                                       
*note transport.pause_reading(): d15.                  Pause receiving.
                                                       
                                                       
*note transport.resume_reading(): d14.                 Resume receiving.
                                                       

Transports that can Send data (TCP and Unix connections, pipes, etc).
Returned from methods like *note loop.create_connection(): 819, *note
loop.create_unix_connection(): 37e5, *note loop.connect_write_pipe():
382d, etc:

Write Transports
................

*note transport.write(): 17b2.                         Write data to the transport.
                                                       
                                                       
*note transport.writelines(): 17b1.                    Write buffers to the transport.
                                                       
                                                       
*note transport.can_write_eof(): 38c5.                 Return *note True: e09. if the transport supports
                                                       sending EOF.
                                                       
                                                       
*note transport.write_eof(): 38c6.                     Close and send EOF after flushing buffered data.
                                                       
                                                       
*note transport.abort(): 389d.                         Close the transport immediately.
                                                       
                                                       
*note transport.get_write_buffer_size(): 38c7.         Return the current size of the output buffer.
                                                       
                                                       
*note transport.get_write_buffer_limits(): fc6.        Return high and low water marks for write flow
                                                       control.
                                                       
                                                       
*note transport.set_write_buffer_limits(): 38c8.       Set new high and low water marks for write flow
                                                       control.
                                                       

Transports returned by *note loop.create_datagram_endpoint(): 93d.:

Datagram Transports
...................

*note transport.sendto(): 4cc.                         Send data to the remote peer.
                                                       
                                                       
*note transport.abort(): 38cc.                         Close the transport immediately.
                                                       

Low-level transport abstraction over subprocesses.  Returned by *note
loop.subprocess_exec(): 3829. and *note loop.subprocess_shell(): 382a.:

Subprocess Transports
.....................

*note transport.get_pid(): 38ce.                       Return the subprocess process id.
                                                       
                                                       
*note transport.get_pipe_transport(): 38cf.            Return the transport for the requested communication
                                                       pipe ('stdin', 'stdout', or 'stderr').
                                                       
                                                       
*note transport.get_returncode(): 38d0.                Return the subprocess return code.
                                                       
                                                       
*note transport.kill(): 38d1.                          Kill the subprocess.
                                                       
                                                       
*note transport.send_signal(): 38d3.                   Send a signal to the subprocess.
                                                       
                                                       
*note transport.terminate(): 38d2.                     Stop the subprocess.
                                                       
                                                       
*note transport.close(): 38d4.                         Kill the subprocess and close all pipes.
                                                       


File: python.info,  Node: Protocols<3>,  Next: Event Loop Policies,  Prev: Transports<2>,  Up: Low-level API Index

5.19.1.128 Protocols
....................

Protocol classes can implement the following 'callback methods':

‘callback’ *note connection_made(): 387a.              Called when a connection is made.
                                                       
                                                       
‘callback’ *note connection_lost(): 38be.              Called when the connection is lost or closed.
                                                       
                                                       
‘callback’ *note pause_writing(): 38c9.                Called when the transport’s buffer goes over the
                                                       high water mark.
                                                       
                                                       
‘callback’ *note resume_writing(): 38ca.               Called when the transport’s buffer drains below the
                                                       low water mark.
                                                       

Streaming Protocols (TCP, Unix Sockets, Pipes)
..............................................

‘callback’ *note data_received(): 1aea.                Called when some data is received.
                                                       
                                                       
‘callback’ *note eof_received(): 38d8.                 Called when an EOF is received.
                                                       

Buffered Streaming Protocols
............................

‘callback’ *note get_buffer(): 38da.                   Called to allocate a new receive buffer.
                                                       
                                                       
‘callback’ *note buffer_updated(): 38db.               Called when the buffer was updated with the received
                                                       data.
                                                       
                                                       
‘callback’ *note eof_received(): 38dc.                 Called when an EOF is received.
                                                       

Datagram Protocols
..................

‘callback’ *note datagram_received(): 38de.            Called when a datagram is received.
                                                       
                                                       
‘callback’ *note error_received(): 38df.               Called when a previous send or receive operation
                                                       raises an *note OSError: 2c0.
                                                       

Subprocess Protocols
....................

‘callback’ *note pipe_data_received(): 1b38.           Called when the child process writes data into its
                                                       'stdout' or 'stderr' pipe.
                                                       
                                                       
‘callback’ *note pipe_connection_lost(): 38e1.         Called when one of the pipes communicating with the
                                                       child process is closed.
                                                       
                                                       
‘callback’ *note process_exited(): 1b37.               Called when the child process has exited.  It can be
                                                       called before *note pipe_data_received(): 1b38. and
                                                       *note pipe_connection_lost(): 38e1. methods.
                                                       


File: python.info,  Node: Event Loop Policies,  Prev: Protocols<3>,  Up: Low-level API Index

5.19.1.129 Event Loop Policies
..............................

Policies is a low-level mechanism to alter the behavior of functions
like *note asyncio.get_event_loop(): 2f2.  See also the main *note
policies section: 3866. for more details.

Accessing Policies
..................

*note asyncio.get_event_loop_policy(): 312.            Return the current process-wide policy.
                                                       
                                                       
*note asyncio.set_event_loop_policy(): 313.            Set a new process-wide policy.
                                                       
                                                       
*note AbstractEventLoopPolicy: 30e.                    Base class for policy objects.
                                                       


File: python.info,  Node: Developing with asyncio,  Prev: Low-level API Index,  Up: asyncio — Asynchronous I/O

5.19.1.130 Developing with asyncio
..................................

Asynchronous programming is different from classic «sequential»
programming.

This page lists common mistakes and traps and explains how to avoid
them.

* Menu:

* Debug Mode::
* Concurrency and Multithreading::
* Running Blocking Code::
* Logging: Logging<3>.
* Detect never-awaited coroutines::
* Detect never-retrieved exceptions::


File: python.info,  Node: Debug Mode,  Next: Concurrency and Multithreading,  Up: Developing with asyncio

5.19.1.131 Debug Mode
.....................

By default asyncio runs in production mode.  In order to ease the
development asyncio has a 'debug mode'.

There are several ways to enable asyncio debug mode:

   * Setting the *note PYTHONASYNCIODEBUG: 2122. environment variable to
     ‘1’.

   * Using the *note Python Development Mode: 509.

   * Passing ‘debug=True’ to *note asyncio.run(): 2f3.

   * Calling *note loop.set_debug(): fc3.

In addition to enabling the debug mode, consider also:

   * setting the log level of the *note asyncio logger: 391f. to *note
     logging.DEBUG: 20c7, for example the following snippet of code can
     be run at startup of the application:

          logging.basicConfig(level=logging.DEBUG)

   * configuring the *note warnings: 118. module to display *note
     ResourceWarning: 54d. warnings.  One way of doing that is by using
     the *note -W: ac7. ‘default’ command line option.

When the debug mode is enabled:

   * Many non-threadsafe asyncio APIs (such as *note loop.call_soon():
     cfc. and *note loop.call_at(): cff. methods) raise an exception if
     they are called from a wrong thread.

   * The execution time of the I/O selector is logged if it takes too
     long to perform an I/O operation.

   * Callbacks taking longer than 100 milliseconds are logged.  The
     *note loop.slow_callback_duration: 3897. attribute can be used to
     set the minimum execution duration in seconds that is considered
     «slow».


File: python.info,  Node: Concurrency and Multithreading,  Next: Running Blocking Code,  Prev: Debug Mode,  Up: Developing with asyncio

5.19.1.132 Concurrency and Multithreading
.........................................

An event loop runs in a thread (typically the main thread) and executes
all callbacks and Tasks in its thread.  While a Task is running in the
event loop, no other Tasks can run in the same thread.  When a Task
executes an ‘await’ expression, the running Task gets suspended, and the
event loop executes the next Task.

To schedule a *note callback: 2d82. from another OS thread, the *note
loop.call_soon_threadsafe(): cfd. method should be used.  Example:

     loop.call_soon_threadsafe(callback, *args)

Almost all asyncio objects are not thread safe, which is typically not a
problem unless there is code that works with them from outside of a Task
or a callback.  If there’s a need for such code to call a low-level
asyncio API, the *note loop.call_soon_threadsafe(): cfd. method should
be used, e.g.:

     loop.call_soon_threadsafe(fut.cancel)

To schedule a coroutine object from a different OS thread, the *note
run_coroutine_threadsafe(): a84. function should be used.  It returns a
*note concurrent.futures.Future: 13ba. to access the result:

     async def coro_func():
          return await asyncio.sleep(1, 42)

     # Later in another OS thread:

     future = asyncio.run_coroutine_threadsafe(coro_func(), loop)
     # Wait for the result:
     result = future.result()

To handle signals the event loop must be run in the main thread.

The *note loop.run_in_executor(): ae8. method can be used with a *note
concurrent.futures.ThreadPoolExecutor: 94a. or *note
InterpreterPoolExecutor: 1d2. to execute blocking code in a different OS
thread without blocking the OS thread that the event loop runs in.

There is currently no way to schedule coroutines or callbacks directly
from a different process (such as one started with *note
multiprocessing: 98.).  The *note Event Loop Methods: 386c. section
lists APIs that can read from pipes and watch file descriptors without
blocking the event loop.  In addition, asyncio’s *note Subprocess: 37a0.
APIs provide a way to start a process and communicate with it from the
event loop.  Lastly, the aforementioned *note loop.run_in_executor():
ae8. method can also be used with a *note
concurrent.futures.ProcessPoolExecutor: 1d6. to execute code in a
different process.


File: python.info,  Node: Running Blocking Code,  Next: Logging<3>,  Prev: Concurrency and Multithreading,  Up: Developing with asyncio

5.19.1.133 Running Blocking Code
................................

Blocking (CPU-bound) code should not be called directly.  For example,
if a function performs a CPU-intensive calculation for 1 second, all
concurrent asyncio Tasks and IO operations would be delayed by 1 second.

An executor can be used to run a task in a different thread, including
in a different interpreter, or even in a different process to avoid
blocking the OS thread with the event loop.  See the *note
loop.run_in_executor(): ae8. method for more details.


File: python.info,  Node: Logging<3>,  Next: Detect never-awaited coroutines,  Prev: Running Blocking Code,  Up: Developing with asyncio

5.19.1.134 Logging
..................

asyncio uses the *note logging: 8b. module and all logging is performed
via the ‘"asyncio"’ logger.

The default log level is *note logging.INFO: 20c8, which can be easily
adjusted:

     logging.getLogger("asyncio").setLevel(logging.WARNING)

Network logging can block the event loop.  It is recommended to use a
separate thread for handling logs or use non-blocking IO. For example,
see *note Dealing with handlers that block: 3924.


File: python.info,  Node: Detect never-awaited coroutines,  Next: Detect never-retrieved exceptions,  Prev: Logging<3>,  Up: Developing with asyncio

5.19.1.135 Detect never-awaited coroutines
..........................................

When a coroutine function is called, but not awaited (e.g.  ‘coro()’
instead of ‘await coro()’) or the coroutine is not scheduled with *note
asyncio.create_task(): 1c9, asyncio will emit a *note RuntimeWarning:
4d8.:

     import asyncio

     async def test():
         print("never scheduled")

     async def main():
         test()

     asyncio.run(main())

Output:

     test.py:7: RuntimeWarning: coroutine 'test' was never awaited
       test()

Output in debug mode:

     test.py:7: RuntimeWarning: coroutine 'test' was never awaited
     Coroutine created at (most recent call last)
       File "../t.py", line 9, in <module>
         asyncio.run(main(), debug=True)

       < .. >

       File "../t.py", line 7, in main
         test()
       test()

The usual fix is to either await the coroutine or call the *note
asyncio.create_task(): 1c9. function:

     async def main():
         await test()


File: python.info,  Node: Detect never-retrieved exceptions,  Prev: Detect never-awaited coroutines,  Up: Developing with asyncio

5.19.1.136 Detect never-retrieved exceptions
............................................

If a *note Future.set_exception(): e7a. is called but the Future object
is never awaited on, the exception would never be propagated to the user
code.  In this case, asyncio would emit a log message when the Future
object is garbage collected.

Example of an unhandled exception:

     import asyncio

     async def bug():
         raise Exception("not consumed")

     async def main():
         asyncio.create_task(bug())

     asyncio.run(main())

Output:

     Task exception was never retrieved
     future: <Task finished coro=<bug() done, defined at test.py:3>
       exception=Exception('not consumed')>

     Traceback (most recent call last):
       File "test.py", line 4, in bug
         raise Exception("not consumed")
     Exception: not consumed

*note Enable the debug mode: 2123. to get the traceback where the task
was created:

     asyncio.run(main(), debug=True)

Output in debug mode:

     Task exception was never retrieved
     future: <Task finished coro=<bug() done, defined at test.py:3>
         exception=Exception('not consumed') created at asyncio/tasks.py:321>

     source_traceback: Object created at (most recent call last):
       File "../t.py", line 9, in <module>
         asyncio.run(main(), debug=True)

     < .. >

     Traceback (most recent call last):
       File "../t.py", line 4, in bug
         raise Exception("not consumed")
     Exception: not consumed

     Nota: The source code for asyncio can be found in Lib/asyncio/(1).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/asyncio/


File: python.info,  Node: socket — Low-level networking interface,  Next: ssl — TLS/SSL wrapper for socket objects,  Prev: asyncio — Asynchronous I/O,  Up: Networking and Interprocess Communication

5.19.2 ‘socket’ — Low-level networking interface
------------------------------------------------

'Source code:' Lib/socket.py(1)

__________________________________________________________________

This module provides access to the BSD 'socket' interface.  It is
available on all modern Unix systems, Windows, MacOS, and probably
additional platforms.

     Nota: Some behavior may be platform dependent, since calls are made
     to the operating system socket APIs.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

The Python interface is a straightforward transliteration of the Unix
system call and library interface for sockets to Python’s
object-oriented style: the *note socket(): fa3. function returns a
'socket object' whose methods implement the various socket system calls.
Parameter types are somewhat higher-level than in the C interface: as
with ‘read()’ and ‘write()’ operations on Python files, buffer
allocation on receive operations is automatic, and buffer length is
implicit on send operations.

Vedi anche
..........

Module *note socketserver: d2.

     Classes that simplify writing network servers.

Module *note ssl: d5.

     A TLS/SSL wrapper for socket objects.

* Menu:

* Socket families::
* Module contents::
* Socket Objects::
* Notes on socket timeouts::
* Example: Example<7>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/socket.py


File: python.info,  Node: Socket families,  Next: Module contents,  Up: socket — Low-level networking interface

5.19.2.1 Socket families
........................

Depending on the system and the build options, various socket families
are supported by this module.

The address format required by a particular socket object is
automatically selected based on the address family specified when the
socket object was created.  Socket addresses are represented as follows:

   - The address of an *note AF_UNIX: 1b98. socket bound to a file
     system node is represented as a string, using the file system
     encoding and the ‘'surrogateescape'’ error handler (see PEP
     383(1)).  An address in Linux’s abstract namespace is returned as a
     *note bytes-like object: 193. with an initial null byte; note that
     sockets in this namespace can communicate with normal file system
     sockets, so programs intended to run on Linux may need to deal with
     both types of address.  A string or bytes-like object can be used
     for either type of address when passing it as an argument.

     Cambiato nella versione 3.3: Previously, *note AF_UNIX: 1b98.
     socket paths were assumed to use UTF-8 encoding.

     Cambiato nella versione 3.5: Writable *note bytes-like object: 193.
     is now accepted.

   - A pair ‘(host, port)’ is used for the *note AF_INET: 1b95. address
     family, where 'host' is a string representing either a hostname in
     internet domain notation like ‘'daring.cwi.nl'’ or an IPv4 address
     like ‘'100.50.200.5'’, and 'port' is an integer.

        - For IPv4 addresses, two special forms are accepted instead of
          a host address: ‘''’ represents ‘INADDR_ANY’, which is used to
          bind to all interfaces, and the string ‘'<broadcast>'’
          represents ‘INADDR_BROADCAST’.  This behavior is not
          compatible with IPv6, therefore, you may want to avoid these
          if you intend to support IPv6 with your Python programs.

   - For *note AF_INET6: 1b96. address family, a four-tuple ‘(host,
     port, flowinfo, scope_id)’ is used, where 'flowinfo' and 'scope_id'
     represent the ‘sin6_flowinfo’ and ‘sin6_scope_id’ members in
     ‘struct sockaddr_in6’ in C. For *note socket: d1. module methods,
     'flowinfo' and 'scope_id' can be omitted just for backward
     compatibility.  Note, however, omission of 'scope_id' can cause
     problems in manipulating scoped IPv6 addresses.

     Cambiato nella versione 3.7: For multicast addresses (with
     'scope_id' meaningful) 'address' may not contain ‘%scope_id’ (or
     ‘zone id’) part.  This information is superfluous and may be safely
     omitted (recommended).

   - ‘AF_NETLINK’ sockets are represented as pairs ‘(pid, groups)’.

   - Linux-only support for TIPC is available using the ‘AF_TIPC’
     address family.  TIPC is an open, non-IP based networked protocol
     designed for use in clustered computer environments.  Addresses are
     represented by a tuple, and the fields depend on the address type.
     The general tuple form is ‘(addr_type, v1, v2, v3 [, scope])’,
     where:

        - 'addr_type' is one of ‘TIPC_ADDR_NAMESEQ’, ‘TIPC_ADDR_NAME’,
          or ‘TIPC_ADDR_ID’.

        - 'scope' is one of ‘TIPC_ZONE_SCOPE’, ‘TIPC_CLUSTER_SCOPE’, and
          ‘TIPC_NODE_SCOPE’.

        - If 'addr_type' is ‘TIPC_ADDR_NAME’, then 'v1' is the server
          type, 'v2' is the port identifier, and 'v3' should be 0.

          If 'addr_type' is ‘TIPC_ADDR_NAMESEQ’, then 'v1' is the server
          type, 'v2' is the lower port number, and 'v3' is the upper
          port number.

          If 'addr_type' is ‘TIPC_ADDR_ID’, then 'v1' is the node, 'v2'
          is the reference, and 'v3' should be set to 0.

   - A tuple ‘(interface, )’ is used for the *note AF_CAN: 392d. address
     family, where 'interface' is a string representing a network
     interface name like ‘'can0'’.  The network interface name ‘''’ can
     be used to receive packets from all network interfaces of this
     family.

        - *note CAN_ISOTP: 392e. protocol require a tuple ‘(interface,
          rx_addr, tx_addr)’ where both additional parameters are
          unsigned long integer that represent a CAN identifier
          (standard or extended).

        - *note CAN_J1939: b2e. protocol require a tuple ‘(interface,
          name, pgn, addr)’ where additional parameters are 64-bit
          unsigned integer representing the ECU name, a 32-bit unsigned
          integer representing the Parameter Group Number (PGN), and an
          8-bit integer representing the address.

   - A string or a tuple ‘(id, unit)’ is used for the ‘SYSPROTO_CONTROL’
     protocol of the ‘PF_SYSTEM’ family.  The string is the name of a
     kernel control using a dynamically assigned ID. The tuple can be
     used if ID and unit number of the kernel control are known or if a
     registered ID is used.

     Added in version 3.3.

   - *note AF_BLUETOOTH: 1b97. supports the following protocols and
     address formats:

        - *note BTPROTO_L2CAP: 283. accepts a tuple ‘(bdaddr, psm[,
          cid[, bdaddr_type]])’ where:

             - ‘bdaddr’ is a string specifying the Bluetooth address.

             - ‘psm’ is an integer specifying the Protocol/Service
               Multiplexer.

             - ‘cid’ is an optional integer specifying the Channel
               Identifier.  If not given, defaults to zero.

             - ‘bdaddr_type’ is an optional integer specifying the
               address type; one of *note BDADDR_BREDR: 392f. (default),
               *note BDADDR_LE_PUBLIC: 3930, *note BDADDR_LE_RANDOM:
               3931.

          Cambiato nella versione 3.14: Added ‘cid’ and ‘bdaddr_type’
          fields.

        - *note BTPROTO_RFCOMM: 3932. accepts ‘(bdaddr, channel)’ where
          ‘bdaddr’ is the Bluetooth address as a string and ‘channel’ is
          an integer.

        - *note BTPROTO_HCI: 281. accepts a format that depends on your
          OS.

             - On Linux it accepts an integer ‘device_id’ or a tuple
               ‘(device_id, [channel])’ where ‘device_id’ specifies the
               number of the Bluetooth device, and ‘channel’ is an
               optional integer specifying the HCI channel (*note
               HCI_CHANNEL_RAW: 3933. by default).

             - On FreeBSD, NetBSD and DragonFly BSD it accepts ‘bdaddr’
               where ‘bdaddr’ is the Bluetooth address as a string.

          Cambiato nella versione 3.2: NetBSD and DragonFlyBSD support
          added.

          Cambiato nella versione 3.13.3: FreeBSD support added.

          Cambiato nella versione 3.14: Added ‘channel’ field.
          ‘device_id’ not packed in a tuple is now accepted.

        - *note BTPROTO_SCO: 282. accepts ‘bdaddr’ where ‘bdaddr’ is the
          Bluetooth address as a string or a *note bytes: 192. object.
          (ex.  ‘'12:23:34:45:56:67'’ or ‘b'12:23:34:45:56:67'’)

          Cambiato nella versione 3.14: FreeBSD support added.

   - *note AF_ALG: ed4. is a Linux-only socket based interface to Kernel
     cryptography.  An algorithm socket is configured with a tuple of
     two to four elements ‘(type, name [, feat [, mask]])’, where:

        - 'type' is the algorithm type as string, e.g.  ‘aead’, ‘hash’,
          ‘skcipher’ or ‘rng’.

        - 'name' is the algorithm name and operation mode as string,
          e.g.  ‘sha256’, ‘hmac(sha256)’, ‘cbc(aes)’ or
          ‘drbg_nopr_ctr_aes256’.

        - 'feat' and 'mask' are unsigned 32bit integers.

     *note Availability: 2128.: Linux >= 2.6.38.

     Some algorithm types require more recent Kernels.

     Added in version 3.6.

   - *note AF_VSOCK: d6f. allows communication between virtual machines
     and their hosts.  The sockets are represented as a ‘(CID, port)’
     tuple where the context ID or CID and port are integers.

     *note Availability: 2128.: Linux >= 3.9

     See ‘vsock(7)(2)’

     Added in version 3.7.

   - *note AF_PACKET: 3934. is a low-level interface directly to network
     devices.  The addresses are represented by the tuple ‘(ifname,
     proto[, pkttype[, hatype[, addr]]])’ where:

        - 'ifname' - String specifying the device name.

        - 'proto' - The Ethernet protocol number.  May be *note
          ETH_P_ALL: 1b0b. to capture all protocols, one of the *note
          ETHERTYPE_* constants: 1b0c. or any other Ethernet protocol
          number.

        - 'pkttype' - Optional integer specifying the packet type:

             - ‘PACKET_HOST’ (the default) - Packet addressed to the
               local host.

             - ‘PACKET_BROADCAST’ - Physical-layer broadcast packet.

             - ‘PACKET_MULTICAST’ - Packet sent to a physical-layer
               multicast address.

             - ‘PACKET_OTHERHOST’ - Packet to some other host that has
               been caught by a device driver in promiscuous mode.

             - ‘PACKET_OUTGOING’ - Packet originating from the local
               host that is looped back to a packet socket.

        - 'hatype' - Optional integer specifying the ARP hardware
          address type.

        - 'addr' - Optional bytes-like object specifying the hardware
          physical address, whose interpretation depends on the device.

     *note Availability: 2128.: Linux >= 2.2.

   - *note AF_QIPCRTR: 3935. is a Linux-only socket based interface for
     communicating with services running on co-processors in Qualcomm
     platforms.  The address family is represented as a ‘(node, port)’
     tuple where the 'node' and 'port' are non-negative integers.

     *note Availability: 2128.: Linux >= 4.7.

     Added in version 3.8.

   - ‘IPPROTO_UDPLITE’ is a variant of UDP which allows you to specify
     what portion of a packet is covered with the checksum.  It adds two
     socket options that you can change.
     ‘self.setsockopt(IPPROTO_UDPLITE, UDPLITE_SEND_CSCOV, length)’ will
     change what portion of outgoing packets are covered by the checksum
     and ‘self.setsockopt(IPPROTO_UDPLITE, UDPLITE_RECV_CSCOV, length)’
     will filter out packets which cover too little of their data.  In
     both cases ‘length’ should be in ‘range(8, 2**16, 8)’.

     Such a socket should be constructed with ‘socket(AF_INET,
     SOCK_DGRAM, IPPROTO_UDPLITE)’ for IPv4 or ‘socket(AF_INET6,
     SOCK_DGRAM, IPPROTO_UDPLITE)’ for IPv6.

     *note Availability: 2128.: Linux >= 2.6.20, FreeBSD >= 10.1

     Added in version 3.9.

   - *note AF_HYPERV: 3936. is a Windows-only socket based interface for
     communicating with Hyper-V hosts and guests.  The address family is
     represented as a ‘(vm_id, service_id)’ tuple where the ‘vm_id’ and
     ‘service_id’ are UUID strings.

     The ‘vm_id’ is the virtual machine identifier or a set of known
     VMID values if the target is not a specific virtual machine.  Known
     VMID constants defined on ‘socket’ are:

        - ‘HV_GUID_ZERO’

        - ‘HV_GUID_BROADCAST’

        - ‘HV_GUID_WILDCARD’ - Used to bind on itself and accept
          connections from all partitions.

        - ‘HV_GUID_CHILDREN’ - Used to bind on itself and accept
          connection from child partitions.

        - ‘HV_GUID_LOOPBACK’ - Used as a target to itself.

        - ‘HV_GUID_PARENT’ - When used as a bind accepts connection from
          the parent partition.  When used as an address target it will
          connect to the parent partition.

     The ‘service_id’ is the service identifier of the registered
     service.

     Added in version 3.12.

If you use a hostname in the 'host' portion of IPv4/v6 socket address,
the program may show a nondeterministic behavior, as Python uses the
first address returned from the DNS resolution.  The socket address will
be resolved differently into an actual IPv4/v6 address, depending on the
results from DNS resolution and/or the host configuration.  For
deterministic behavior use a numeric address in 'host' portion.

All errors raise exceptions.  The normal exceptions for invalid argument
types and out-of-memory conditions can be raised.  Errors related to
socket or address semantics raise *note OSError: 2c0. or one of its
subclasses.

Non-blocking mode is supported through *note setblocking(): 3021.  A
generalization of this based on timeouts is supported through *note
settimeout(): 3937.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0383/

   (2) https://manpages.debian.org/vsock(7)


File: python.info,  Node: Module contents,  Next: Socket Objects,  Prev: Socket families,  Up: socket — Low-level networking interface

5.19.2.2 Module contents
........................

The module *note socket: d1. exports the following elements.

* Menu:

* Exceptions: Exceptions<17>.
* Constants: Constants<8>.
* Functions: Functions<7>.


File: python.info,  Node: Exceptions<17>,  Next: Constants<8>,  Up: Module contents

5.19.2.3 Exceptions
...................

 -- Eccezione: socket.error

     A deprecated alias of *note OSError: 2c0.

     Cambiato nella versione 3.3: Following PEP 3151(1), this class was
     made an alias of *note OSError: 2c0.

 -- Eccezione: socket.herror

     A subclass of *note OSError: 2c0, this exception is raised for
     address-related errors, i.e.  for functions that use 'h_errno' in
     the POSIX C API, including *note gethostbyname_ex(): 1c6d. and
     *note gethostbyaddr(): 1c6c.  The accompanying value is a pair
     ‘(h_errno, string)’ representing an error returned by a library
     call.  'h_errno' is a numeric value, while 'string' represents the
     description of 'h_errno', as returned by the ‘hstrerror()’ C
     function.

     Cambiato nella versione 3.3: This class was made a subclass of
     *note OSError: 2c0.

 -- Eccezione: socket.gaierror

     A subclass of *note OSError: 2c0, this exception is raised for
     address-related errors by *note getaddrinfo(): 1aab. and *note
     getnameinfo(): 1a22.  The accompanying value is a pair ‘(error,
     string)’ representing an error returned by a library call.
     'string' represents the description of 'error', as returned by the
     ‘gai_strerror()’ C function.  The numeric 'error' value will match
     one of the ‘EAI_*’ constants defined in this module.

     Cambiato nella versione 3.3: This class was made a subclass of
     *note OSError: 2c0.

 -- Eccezione: socket.timeout

     A deprecated alias of *note TimeoutError: a38.

     A subclass of *note OSError: 2c0, this exception is raised when a
     timeout occurs on a socket which has had timeouts enabled via a
     prior call to *note settimeout(): 3937. (or implicitly through
     *note setdefaulttimeout(): 393b.).  The accompanying value is a
     string whose value is currently always «timed out».

     Cambiato nella versione 3.3: This class was made a subclass of
     *note OSError: 2c0.

     Cambiato nella versione 3.10: This class was made an alias of *note
     TimeoutError: a38.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3151/


File: python.info,  Node: Constants<8>,  Next: Functions<7>,  Prev: Exceptions<17>,  Up: Module contents

5.19.2.4 Constants
..................

The AF_* and SOCK_* constants are now ‘AddressFamily’ and ‘SocketKind’
*note IntEnum: edd. collections.

Added in version 3.4.

 -- Dati: socket.AF_UNIX
 -- Dati: socket.AF_INET
 -- Dati: socket.AF_INET6

     These constants represent the address (and protocol) families, used
     for the first argument to *note socket(): fa3.  If the *note
     AF_UNIX: 1b98. constant is not defined then this protocol is
     unsupported.  More constants may be available depending on the
     system.

 -- Dati: socket.AF_UNSPEC

     *note AF_UNSPEC: 3880. means that *note getaddrinfo(): 1aab. should
     return socket addresses for any address family (either IPv4, IPv6,
     or any other) that can be used.

 -- Dati: socket.SOCK_STREAM
 -- Dati: socket.SOCK_DGRAM
 -- Dati: socket.SOCK_RAW
 -- Dati: socket.SOCK_RDM
 -- Dati: socket.SOCK_SEQPACKET

     These constants represent the socket types, used for the second
     argument to *note socket(): fa3.  More constants may be available
     depending on the system.  (Only *note SOCK_STREAM: 14fb. and *note
     SOCK_DGRAM: 14fa. appear to be generally useful.)

 -- Dati: socket.SOCK_CLOEXEC
 -- Dati: socket.SOCK_NONBLOCK

     These two constants, if defined, can be combined with the socket
     types and allow you to set some flags atomically (thus avoiding
     possible race conditions and the need for separate calls).

     Vedi anche
     ..........

     Secure File Descriptor Handling(1) for a more thorough explanation.

     *note Availability: 2128.: Linux >= 2.6.27.

     Added in version 3.2.

 -- Dati: SO_*
 -- Dati: socket.SOMAXCONN

 -- Dati: MSG_*

 -- Dati: SOL_*

 -- Dati: SCM_*

 -- Dati: IPPROTO_*

 -- Dati: IPPORT_*

 -- Dati: INADDR_*

 -- Dati: IP_*

 -- Dati: IPV6_*

 -- Dati: EAI_*

 -- Dati: AI_*

 -- Dati: NI_*

 -- Dati: TCP_*

     Many constants of these forms, documented in the Unix documentation
     on sockets and/or the IP protocol, are also defined in the socket
     module.  They are generally used in arguments to the *note
     setsockopt(): ed3. and *note getsockopt(): ed2. methods of socket
     objects.  In most cases, only those symbols that are defined in the
     Unix header files are defined; for a few symbols, default values
     are provided.

     Cambiato nella versione 3.6: ‘SO_DOMAIN’, ‘SO_PROTOCOL’,
     ‘SO_PEERSEC’, ‘SO_PASSSEC’, ‘TCP_USER_TIMEOUT’, ‘TCP_CONGESTION’
     were added.

     Cambiato nella versione 3.6.5: Added support for ‘TCP_FASTOPEN’,
     ‘TCP_KEEPCNT’ on Windows platforms when available.

     Cambiato nella versione 3.7: ‘TCP_NOTSENT_LOWAT’ was added.

     Added support for ‘TCP_KEEPIDLE’, ‘TCP_KEEPINTVL’ on Windows
     platforms when available.

     Cambiato nella versione 3.10: ‘IP_RECVTOS’ was added.  Added
     ‘TCP_KEEPALIVE’.  On MacOS this constant can be used in the same
     way that ‘TCP_KEEPIDLE’ is used on Linux.

     Cambiato nella versione 3.11: Added ‘TCP_CONNECTION_INFO’.  On
     MacOS this constant can be used in the same way that ‘TCP_INFO’ is
     used on Linux and BSD.

     Cambiato nella versione 3.12: Added ‘SO_RTABLE’ and
     ‘SO_USER_COOKIE’.  On OpenBSD and FreeBSD respectively those
     constants can be used in the same way that ‘SO_MARK’ is used on
     Linux.  Also added missing TCP socket options from Linux:
     ‘TCP_MD5SIG’, ‘TCP_THIN_LINEAR_TIMEOUTS’, ‘TCP_THIN_DUPACK’,
     ‘TCP_REPAIR’, ‘TCP_REPAIR_QUEUE’, ‘TCP_QUEUE_SEQ’,
     ‘TCP_REPAIR_OPTIONS’, ‘TCP_TIMESTAMP’, ‘TCP_CC_INFO’,
     ‘TCP_SAVE_SYN’, ‘TCP_SAVED_SYN’, ‘TCP_REPAIR_WINDOW’,
     ‘TCP_FASTOPEN_CONNECT’, ‘TCP_ULP’, ‘TCP_MD5SIG_EXT’,
     ‘TCP_FASTOPEN_KEY’, ‘TCP_FASTOPEN_NO_COOKIE’,
     ‘TCP_ZEROCOPY_RECEIVE’, ‘TCP_INQ’, ‘TCP_TX_DELAY’.  Added
     ‘IP_PKTINFO’, ‘IP_UNBLOCK_SOURCE’, ‘IP_BLOCK_SOURCE’,
     ‘IP_ADD_SOURCE_MEMBERSHIP’, ‘IP_DROP_SOURCE_MEMBERSHIP’.

     Cambiato nella versione 3.13: Added ‘SO_BINDTOIFINDEX’.  On Linux
     this constant can be used in the same way that ‘SO_BINDTODEVICE’ is
     used, but with the index of a network interface instead of its
     name.

     Cambiato nella versione 3.14: Added missing ‘IP_FREEBIND’,
     ‘IP_RECVERR’, ‘IPV6_RECVERR’, ‘IP_RECVTTL’, and
     ‘IP_RECVORIGDSTADDR’ on Linux.

     Cambiato nella versione 3.14: Added support for ‘TCP_QUICKACK’ on
     Windows platforms when available.

 -- Dati: socket.AF_CAN
 -- Dati: socket.PF_CAN

 -- Dati: SOL_CAN_*

 -- Dati: CAN_*

     Many constants of these forms, documented in the Linux
     documentation, are also defined in the socket module.

     *note Availability: 2128.: Linux >= 2.6.25, NetBSD >= 8.

     Added in version 3.3.

     Cambiato nella versione 3.11: NetBSD support was added.

     Cambiato nella versione 3.14: Restored missing ‘CAN_RAW_ERR_FILTER’
     on Linux.

 -- Dati: socket.CAN_BCM

 -- Dati: CAN_BCM_*

     CAN_BCM, in the CAN protocol family, is the broadcast manager (BCM)
     protocol.  Broadcast manager constants, documented in the Linux
     documentation, are also defined in the socket module.

     *note Availability: 2128.: Linux >= 2.6.25.

          Nota: The ‘CAN_BCM_CAN_FD_FRAME’ flag is only available on
          Linux >= 4.8.

     Added in version 3.4.

 -- Dati: socket.CAN_RAW_FD_FRAMES

     Enables CAN FD support in a CAN_RAW socket.  This is disabled by
     default.  This allows your application to send both CAN and CAN FD
     frames; however, you must accept both CAN and CAN FD frames when
     reading from the socket.

     This constant is documented in the Linux documentation.

     *note Availability: 2128.: Linux >= 3.6.

     Added in version 3.5.

 -- Dati: socket.CAN_RAW_JOIN_FILTERS

     Joins the applied CAN filters such that only CAN frames that match
     all given CAN filters are passed to user space.

     This constant is documented in the Linux documentation.

     *note Availability: 2128.: Linux >= 4.1.

     Added in version 3.9.

 -- Dati: socket.CAN_ISOTP

     CAN_ISOTP, in the CAN protocol family, is the ISO-TP (ISO 15765-2)
     protocol.  ISO-TP constants, documented in the Linux documentation.

     *note Availability: 2128.: Linux >= 2.6.25.

     Added in version 3.7.

 -- Dati: socket.CAN_J1939

     CAN_J1939, in the CAN protocol family, is the SAE J1939 protocol.
     J1939 constants, documented in the Linux documentation.

     *note Availability: 2128.: Linux >= 5.4.

     Added in version 3.9.

 -- Dati: socket.AF_DIVERT
 -- Dati: socket.PF_DIVERT

     These two constants, documented in the FreeBSD divert(4) manual
     page, are also defined in the socket module.

     *note Availability: 2128.: FreeBSD >= 14.0.

     Added in version 3.12.

 -- Dati: socket.AF_PACKET
 -- Dati: socket.PF_PACKET

 -- Dati: PACKET_*

     Many constants of these forms, documented in the Linux
     documentation, are also defined in the socket module.

     *note Availability: 2128.: Linux >= 2.2.

 -- Dati: socket.ETH_P_ALL

     ‘ETH_P_ALL’ can be used in the *note socket: fa3. constructor as
     'proto' for the *note AF_PACKET: 3934. family in order to capture
     every packet, regardless of protocol.

     For more information, see the ‘packet(7)(2)’ manpage.

     *note Availability: 2128.: Linux.

     Added in version 3.12.

 -- Dati: socket.AF_RDS
 -- Dati: socket.PF_RDS
 -- Dati: socket.SOL_RDS

 -- Dati: RDS_*

     Many constants of these forms, documented in the Linux
     documentation, are also defined in the socket module.

     *note Availability: 2128.: Linux >= 2.6.30.

     Added in version 3.3.

 -- Dati: socket.SIO_RCVALL
 -- Dati: socket.SIO_KEEPALIVE_VALS
 -- Dati: socket.SIO_LOOPBACK_FAST_PATH

 -- Dati: RCVALL_*

     Constants for Windows” WSAIoctl().  The constants are used as
     arguments to the *note ioctl(): ed0. method of socket objects.

     Cambiato nella versione 3.6: ‘SIO_LOOPBACK_FAST_PATH’ was added.

 -- Dati: TIPC_*

     TIPC related constants, matching the ones exported by the C socket
     API. See the TIPC documentation for more information.

 -- Dati: socket.AF_ALG
 -- Dati: socket.SOL_ALG

 -- Dati: ALG_*

     Constants for Linux Kernel cryptography.

     *note Availability: 2128.: Linux >= 2.6.38.

     Added in version 3.6.

 -- Dati: socket.AF_VSOCK
 -- Dati: socket.IOCTL_VM_SOCKETS_GET_LOCAL_CID

 -- Dati: VMADDR*

 -- Dati: SO_VM*

     Constants for Linux host/guest communication.

     *note Availability: 2128.: Linux >= 4.8.

     Added in version 3.7.

 -- Dati: socket.AF_LINK

     *note Availability: 2128.: BSD, macOS.

     Added in version 3.4.

 -- Dati: socket.has_ipv6

     This constant contains a boolean value which indicates if IPv6 is
     supported on this platform.

 -- Dati: socket.AF_BLUETOOTH
 -- Dati: socket.BTPROTO_L2CAP
 -- Dati: socket.BTPROTO_RFCOMM
 -- Dati: socket.BTPROTO_HCI
 -- Dati: socket.BTPROTO_SCO

     Integer constants for use with Bluetooth addresses.

 -- Dati: socket.BDADDR_ANY
 -- Dati: socket.BDADDR_LOCAL

     These are string constants containing Bluetooth addresses with
     special meanings.  For example, *note BDADDR_ANY: 394c. can be used
     to indicate any address when specifying the binding socket with
     *note BTPROTO_RFCOMM: 3932.

 -- Dati: socket.BDADDR_BREDR
 -- Dati: socket.BDADDR_LE_PUBLIC
 -- Dati: socket.BDADDR_LE_RANDOM

     These constants describe the Bluetooth address type when binding or
     connecting a *note BTPROTO_L2CAP: 283. socket.

     *note Availability: 2128.: Linux, FreeBSD

     Added in version 3.14.

 -- Dati: socket.SOL_RFCOMM
 -- Dati: socket.SOL_L2CAP
 -- Dati: socket.SOL_HCI
 -- Dati: socket.SOL_SCO
 -- Dati: socket.SOL_BLUETOOTH

     Used in the level argument to the *note setsockopt(): ed3. and
     *note getsockopt(): ed2. methods of Bluetooth socket objects.

     *note SOL_BLUETOOTH: 3952. is only available on Linux.  Other
     constants are available if the corresponding protocol is supported.

 -- Dati: SO_L2CAP_*
 -- Dati: socket.L2CAP_LM

 -- Dati: L2CAP_LM_*

 -- Dati: SO_RFCOMM_*

 -- Dati: RFCOMM_LM_*

 -- Dati: SO_SCO_*

 -- Dati: SO_BTH_*

 -- Dati: BT_*

     Used in the option name and value argument to the *note
     setsockopt(): ed3. and *note getsockopt(): ed2. methods of
     Bluetooth socket objects.

     ‘BT_*’ and *note L2CAP_LM: 3953. are only available on Linux.
     ‘SO_BTH_*’ are only available on Windows.  Other constants may be
     available on Linux and various BSD platforms.

     Added in version 3.14.

 -- Dati: socket.HCI_FILTER
 -- Dati: socket.HCI_TIME_STAMP
 -- Dati: socket.HCI_DATA_DIR
 -- Dati: socket.SO_HCI_EVT_FILTER
 -- Dati: socket.SO_HCI_PKT_FILTER

     Option names for use with *note BTPROTO_HCI: 281.  Availability and
     format of the option values depend on platform.

     Cambiato nella versione 3.14: Added ‘SO_HCI_EVT_FILTER’ and
     ‘SO_HCI_PKT_FILTER’ on NetBSD and DragonFly BSD. Added
     ‘HCI_DATA_DIR’ on FreeBSD, NetBSD and DragonFly BSD.

 -- Dati: socket.HCI_DEV_NONE

     The ‘device_id’ value used to create an HCI socket that isn’t
     specific to a single Bluetooth adapter.

     *note Availability: 2128.: Linux

     Added in version 3.14.

 -- Dati: socket.HCI_CHANNEL_RAW
 -- Dati: socket.HCI_CHANNEL_USER
 -- Dati: socket.HCI_CHANNEL_MONITOR
 -- Dati: socket.HCI_CHANNEL_CONTROL
 -- Dati: socket.HCI_CHANNEL_LOGGING

     Possible values for ‘channel’ field in the *note BTPROTO_HCI: 281.
     address.

     *note Availability: 2128.: Linux

     Added in version 3.14.

 -- Dati: socket.AF_QIPCRTR

     Constant for Qualcomm’s IPC router protocol, used to communicate
     with service providing remote processors.

     *note Availability: 2128.: Linux >= 4.7.

 -- Dati: socket.SCM_CREDS2
 -- Dati: socket.LOCAL_CREDS
 -- Dati: socket.LOCAL_CREDS_PERSISTENT

     LOCAL_CREDS and LOCAL_CREDS_PERSISTENT can be used with SOCK_DGRAM,
     SOCK_STREAM sockets, equivalent to Linux/DragonFlyBSD SO_PASSCRED,
     while LOCAL_CREDS sends the credentials at first read,
     LOCAL_CREDS_PERSISTENT sends for each read, SCM_CREDS2 must be then
     used for the latter for the message type.

     Added in version 3.11.

     *note Availability: 2128.: FreeBSD.

 -- Dati: socket.SO_INCOMING_CPU

     Constant to optimize CPU locality, to be used in conjunction with
     ‘SO_REUSEPORT’.

     Added in version 3.11.

     *note Availability: 2128.: Linux >= 3.9

 -- Dati: socket.SO_REUSEPORT_LB

          Constant to enable duplicate address and port bindings with
          load balancing.

     Added in version 3.14.

     *note Availability: 2128.: FreeBSD >= 12.0

 -- Dati: socket.AF_HYPERV
 -- Dati: socket.HV_PROTOCOL_RAW
 -- Dati: socket.HVSOCKET_CONNECT_TIMEOUT
 -- Dati: socket.HVSOCKET_CONNECT_TIMEOUT_MAX
 -- Dati: socket.HVSOCKET_CONNECTED_SUSPEND
 -- Dati: socket.HVSOCKET_ADDRESS_FLAG_PASSTHRU
 -- Dati: socket.HV_GUID_ZERO
 -- Dati: socket.HV_GUID_WILDCARD
 -- Dati: socket.HV_GUID_BROADCAST
 -- Dati: socket.HV_GUID_CHILDREN
 -- Dati: socket.HV_GUID_LOOPBACK
 -- Dati: socket.HV_GUID_PARENT

     Constants for Windows Hyper-V sockets for host/guest
     communications.

     *note Availability: 2128.: Windows.

     Added in version 3.12.

 -- Dati: socket.ETHERTYPE_ARP
 -- Dati: socket.ETHERTYPE_IP
 -- Dati: socket.ETHERTYPE_IPV6
 -- Dati: socket.ETHERTYPE_VLAN

     IEEE 802.3 protocol number(3).  constants.

     *note Availability: 2128.: Linux, FreeBSD, macOS.

     Added in version 3.12.

 -- Dati: socket.SHUT_RD
 -- Dati: socket.SHUT_WR
 -- Dati: socket.SHUT_RDWR

     These constants are used by the *note shutdown(): 3974. method of
     socket objects.

     *note Availability: 2128.: not WASI.

   ---------- Footnotes ----------

   (1) https://udrepper.livejournal.com/20407.html

   (2) https://manpages.debian.org/packet(7)

   (3) 
https://www.iana.org/assignments/ieee-802-numbers/ieee-802-numbers.txt


File: python.info,  Node: Functions<7>,  Prev: Constants<8>,  Up: Module contents

5.19.2.5 Functions
..................

* Menu:

* Creating sockets::
* Other functions: Other functions<2>.


File: python.info,  Node: Creating sockets,  Next: Other functions<2>,  Up: Functions<7>

5.19.2.6 Creating sockets
.........................

The following functions all create *note socket objects: 3977.

 -- Classe: socket.socket (family=AF_INET, type=SOCK_STREAM, proto=0,
          fileno=None)

     Create a new socket using the given address family, socket type and
     protocol number.  The address family should be *note AF_INET: 1b95.
     (the default), *note AF_INET6: 1b96, *note AF_UNIX: 1b98, *note
     AF_CAN: 392d, *note AF_PACKET: 3934, or *note AF_RDS: 3944.  The
     socket type should be *note SOCK_STREAM: 14fb. (the default), *note
     SOCK_DGRAM: 14fa, *note SOCK_RAW: 393d. or perhaps one of the other
     ‘SOCK_’ constants.  The protocol number is usually zero and may be
     omitted or in the case where the address family is *note AF_CAN:
     392d. the protocol should be one of ‘CAN_RAW’, *note CAN_BCM: 11a5,
     *note CAN_ISOTP: 392e. or *note CAN_J1939: b2e.

     If 'fileno' is specified, the values for 'family', 'type', and
     'proto' are auto-detected from the specified file descriptor.
     Auto-detection can be overruled by calling the function with
     explicit 'family', 'type', or 'proto' arguments.  This only affects
     how Python represents e.g.  the return value of *note
     socket.getpeername(): 38bf. but not the actual OS resource.  Unlike
     *note socket.fromfd(): 3978, 'fileno' will return the same socket
     and not a duplicate.  This may help close a detached socket using
     *note socket.close(): d6c.

     The newly created socket is *note non-inheritable: 10fe.

     Raises an *note auditing event: 1c56. ‘socket.__new__’ with
     arguments ‘self’, ‘family’, ‘type’, ‘protocol’.

     Cambiato nella versione 3.3: The AF_CAN family was added.  The
     AF_RDS family was added.

     Cambiato nella versione 3.4: The CAN_BCM protocol was added.

     Cambiato nella versione 3.4: The returned socket is now
     non-inheritable.

     Cambiato nella versione 3.7: The CAN_ISOTP protocol was added.

     Cambiato nella versione 3.7: When *note SOCK_NONBLOCK: e06. or
     *note SOCK_CLOEXEC: e07. bit flags are applied to 'type' they are
     cleared, and *note socket.type: e08. will not reflect them.  They
     are still passed to the underlying system ‘socket()’ call.
     Therefore,

          sock = socket.socket(
              socket.AF_INET,
              socket.SOCK_STREAM | socket.SOCK_NONBLOCK)

     will still create a non-blocking socket on OSes that support
     ‘SOCK_NONBLOCK’, but ‘sock.type’ will be set to
     ‘socket.SOCK_STREAM’.

     Cambiato nella versione 3.9: The CAN_J1939 protocol was added.

     Cambiato nella versione 3.10: The IPPROTO_MPTCP protocol was added.

 -- Funzione: socket.socketpair ([family[, type[, proto]]])

     Build a pair of connected socket objects using the given address
     family, socket type, and protocol number.  Address family, socket
     type, and protocol number are as for the *note socket(): fa3.
     function above.  The default family is *note AF_UNIX: 1b98. if
     defined on the platform; otherwise, the default is *note AF_INET:
     1b95.

     The newly created sockets are *note non-inheritable: 10fe.

     Cambiato nella versione 3.2: The returned socket objects now
     support the whole socket API, rather than a subset.

     Cambiato nella versione 3.4: The returned sockets are now
     non-inheritable.

     Cambiato nella versione 3.5: Windows support added.

 -- Funzione: socket.create_connection (address, timeout=GLOBAL_DEFAULT,
          source_address=None, *, all_errors=False)

     Connect to a TCP service listening on the internet 'address' (a
     2-tuple ‘(host, port)’), and return the socket object.  This is a
     higher-level function than *note socket.connect(): fa5.: if 'host'
     is a non-numeric hostname, it will try to resolve it for both *note
     AF_INET: 1b95. and *note AF_INET6: 1b96, and then try to connect to
     all possible addresses in turn until a connection succeeds.  This
     makes it easy to write clients that are compatible to both IPv4 and
     IPv6.

     Passing the optional 'timeout' parameter will set the timeout on
     the socket instance before attempting to connect.  If no 'timeout'
     is supplied, the global default timeout setting returned by *note
     getdefaulttimeout(): 3979. is used.

     If supplied, 'source_address' must be a 2-tuple ‘(host, port)’ for
     the socket to bind to as its source address before connecting.  If
     host or port are “” or 0 respectively the OS default behavior will
     be used.

     When a connection cannot be created, an exception is raised.  By
     default, it is the exception from the last address in the list.  If
     'all_errors' is ‘True’, it is an *note ExceptionGroup: 4d3.
     containing the errors of all attempts.

     Cambiato nella versione 3.2: 'source_address' was added.

     Cambiato nella versione 3.11: 'all_errors' was added.

 -- Funzione: socket.create_server (address, *, family=AF_INET,
          backlog=None, reuse_port=False, dualstack_ipv6=False)

     Convenience function which creates a TCP socket bound to 'address'
     (a 2-tuple ‘(host, port)’) and returns the socket object.

     'family' should be either *note AF_INET: 1b95. or *note AF_INET6:
     1b96.  'backlog' is the queue size passed to *note socket.listen():
     1060.; if not specified , a default reasonable value is chosen.
     'reuse_port' dictates whether to set the ‘SO_REUSEPORT’ socket
     option.

     If 'dualstack_ipv6' is true, 'family' is *note AF_INET6: 1b96. and
     the platform supports it the socket will be able to accept both
     IPv4 and IPv6 connections, else it will raise *note ValueError:
     2ec.  Most POSIX platforms and Windows are supposed to support this
     functionality.  When this functionality is enabled the address
     returned by *note socket.getpeername(): 38bf. when an IPv4
     connection occurs will be an IPv6 address represented as an
     IPv4-mapped IPv6 address.  If 'dualstack_ipv6' is false it will
     explicitly disable this functionality on platforms that enable it
     by default (e.g.  Linux).  This parameter can be used in
     conjunction with *note has_dualstack_ipv6(): c23.:

          import socket

          addr = ("", 8080)  # all interfaces, port 8080
          if socket.has_dualstack_ipv6():
              s = socket.create_server(addr, family=socket.AF_INET6, dualstack_ipv6=True)
          else:
              s = socket.create_server(addr)

          Nota: On POSIX platforms the ‘SO_REUSEADDR’ socket option is
          set in order to immediately reuse previous sockets which were
          bound on the same 'address' and remained in TIME_WAIT state.

     Added in version 3.8.

 -- Funzione: socket.has_dualstack_ipv6 ()

     Return ‘True’ if the platform supports creating a TCP socket which
     can handle both IPv4 and IPv6 connections.

     Added in version 3.8.

 -- Funzione: socket.fromfd (fd, family, type, proto=0)

     Duplicate the file descriptor 'fd' (an integer as returned by a
     file object’s *note fileno(): 1795. method) and build a socket
     object from the result.  Address family, socket type and protocol
     number are as for the *note socket(): fa3. function above.  The
     file descriptor should refer to a socket, but this is not checked —
     subsequent operations on the object may fail if the file descriptor
     is invalid.  This function is rarely needed, but can be used to get
     or set socket options on a socket passed to a program as standard
     input or output (such as a server started by the Unix inet daemon).
     The socket is assumed to be in blocking mode.

     The newly created socket is *note non-inheritable: 10fe.

     Cambiato nella versione 3.4: The returned socket is now
     non-inheritable.

 -- Funzione: socket.fromshare (data)

     Instantiate a socket from data obtained from the *note
     socket.share(): e04. method.  The socket is assumed to be in
     blocking mode.

     *note Availability: 2128.: Windows.

     Added in version 3.3.

 -- Dati: socket.SocketType

     This is a Python type object that represents the socket object
     type.  It is the same as ‘type(socket(...))’.


File: python.info,  Node: Other functions<2>,  Prev: Creating sockets,  Up: Functions<7>

5.19.2.7 Other functions
........................

The *note socket: d1. module also offers various network-related
services:

 -- Funzione: socket.close (fd)

     Close a socket file descriptor.  This is like *note os.close():
     d6d, but for sockets.  On some platforms (most noticeable Windows)
     *note os.close(): d6d. does not work for socket file descriptors.

     Added in version 3.7.

 -- Funzione: socket.getaddrinfo (host, port, family=AF_UNSPEC, type=0,
          proto=0, flags=0)

     This function wraps the C function ‘getaddrinfo’ of the underlying
     system.

     Translate the 'host'/'port' argument into a sequence of 5-tuples
     that contain all the necessary arguments for creating a socket
     connected to that service.  'host' is a domain name, a string
     representation of an IPv4/v6 address or ‘None’.  'port' is a string
     service name such as ‘'http'’, a numeric port number or ‘None’.  By
     passing ‘None’ as the value of 'host' and 'port', you can pass
     ‘NULL’ to the underlying C API.

     The 'family', 'type' and 'proto' arguments can be optionally
     specified in order to provide options and limit the list of
     addresses returned.  Pass their default values (*note AF_UNSPEC:
     3880, 0, and 0, respectively) to not limit the results.  See the
     note below for details.

     The 'flags' argument can be one or several of the ‘AI_*’ constants,
     and will influence how results are computed and returned.  For
     example, ‘AI_NUMERICHOST’ will disable domain name resolution and
     will raise an error if 'host' is a domain name.

     The function returns a list of 5-tuples with the following
     structure:

     ‘(family, type, proto, canonname, sockaddr)’

     In these tuples, 'family', 'type', 'proto' are all integers and are
     meant to be passed to the *note socket(): fa3. function.
     'canonname' will be a string representing the canonical name of the
     'host' if ‘AI_CANONNAME’ is part of the 'flags' argument; else
     'canonname' will be empty.  'sockaddr' is a tuple describing a
     socket address, whose format depends on the returned 'family' (a
     ‘(address, port)’ 2-tuple for *note AF_INET: 1b95, a ‘(address,
     port, flowinfo, scope_id)’ 4-tuple for *note AF_INET6: 1b96.), and
     is meant to be passed to the *note socket.connect(): fa5. method.

          Nota: If you intend to use results from ‘getaddrinfo()’ to
          create a socket (rather than, for example, retrieve
          'canonname'), consider limiting the results by 'type' (e.g.
          *note SOCK_STREAM: 14fb. or *note SOCK_DGRAM: 14fa.) and/or
          'proto' (e.g.  ‘IPPROTO_TCP’ or ‘IPPROTO_UDP’) that your
          application can handle.

          The behavior with default values of 'family', 'type', 'proto'
          and 'flags' is system-specific.

          Many systems (for example, most Linux configurations) will
          return a sorted list of all matching addresses.  These
          addresses should generally be tried in order until a
          connection succeeds (possibly tried in parallel, for example,
          using a Happy Eyeballs(1) algorithm).  In these cases,
          limiting the 'type' and/or 'proto' can help eliminate
          unsuccessful or unusable connection attempts.

          Some systems will, however, only return a single address.
          (For example, this was reported on Solaris and AIX
          configurations.)  On these systems, limiting the 'type' and/or
          'proto' helps ensure that this address is usable.

     Raises an *note auditing event: 1c56. ‘socket.getaddrinfo’ with
     arguments ‘host’, ‘port’, ‘family’, ‘type’, ‘protocol’.

     The following example fetches address information for a
     hypothetical TCP connection to ‘example.org’ on port 80 (results
     may differ on your system if IPv6 isn’t enabled):

          >>> socket.getaddrinfo("example.org", 80, proto=socket.IPPROTO_TCP)
          [(socket.AF_INET6, socket.SOCK_STREAM,
           6, '', ('2606:2800:220:1:248:1893:25c8:1946', 80, 0, 0)),
           (socket.AF_INET, socket.SOCK_STREAM,
           6, '', ('93.184.216.34', 80))]

     Cambiato nella versione 3.2: parameters can now be passed using
     keyword arguments.

     Cambiato nella versione 3.7: for IPv6 multicast addresses, string
     representing an address will not contain ‘%scope_id’ part.

 -- Funzione: socket.getfqdn ([name])

     Return a fully qualified domain name for 'name'.  If 'name' is
     omitted or empty, it is interpreted as the local host.  To find the
     fully qualified name, the hostname returned by *note
     gethostbyaddr(): 1c6c. is checked, followed by aliases for the
     host, if available.  The first name which includes a period is
     selected.  In case no fully qualified domain name is available and
     'name' was provided, it is returned unchanged.  If 'name' was empty
     or equal to ‘'0.0.0.0'’, the hostname from *note gethostname():
     300b. is returned.

 -- Funzione: socket.gethostbyname (hostname)

     Translate a host name to IPv4 address format.  The IPv4 address is
     returned as a string, such as ‘'100.50.200.5'’.  If the host name
     is an IPv4 address itself it is returned unchanged.  See *note
     gethostbyname_ex(): 1c6d. for a more complete interface.  *note
     gethostbyname(): 397c. does not support IPv6 name resolution, and
     *note getaddrinfo(): 1aab. should be used instead for IPv4/v6 dual
     stack support.

     Raises an *note auditing event: 1c56. ‘socket.gethostbyname’ with
     argument ‘hostname’.

     *note Availability: 2128.: not WASI.

 -- Funzione: socket.gethostbyname_ex (hostname)

     Translate a host name to IPv4 address format, extended interface.
     Return a 3-tuple ‘(hostname, aliaslist, ipaddrlist)’ where
     'hostname' is the host’s primary host name, 'aliaslist' is a
     (possibly empty) list of alternative host names for the same
     address, and 'ipaddrlist' is a list of IPv4 addresses for the same
     interface on the same host (often but not always a single address).
     *note gethostbyname_ex(): 1c6d. does not support IPv6 name
     resolution, and *note getaddrinfo(): 1aab. should be used instead
     for IPv4/v6 dual stack support.

     Raises an *note auditing event: 1c56. ‘socket.gethostbyname’ with
     argument ‘hostname’.

     *note Availability: 2128.: not WASI.

 -- Funzione: socket.gethostname ()

     Return a string containing the hostname of the machine where the
     Python interpreter is currently executing.

     Raises an *note auditing event: 1c56. ‘socket.gethostname’ with no
     arguments.

     Note: *note gethostname(): 300b. doesn’t always return the fully
     qualified domain name; use *note getfqdn(): 1ad5. for that.

     *note Availability: 2128.: not WASI.

 -- Funzione: socket.gethostbyaddr (ip_address)

     Return a 3-tuple ‘(hostname, aliaslist, ipaddrlist)’ where
     'hostname' is the primary host name responding to the given
     'ip_address', 'aliaslist' is a (possibly empty) list of alternative
     host names for the same address, and 'ipaddrlist' is a list of
     IPv4/v6 addresses for the same interface on the same host (most
     likely containing only a single address).  To find the fully
     qualified domain name, use the function *note getfqdn(): 1ad5.
     *note gethostbyaddr(): 1c6c. supports both IPv4 and IPv6.

     Raises an *note auditing event: 1c56. ‘socket.gethostbyaddr’ with
     argument ‘ip_address’.

     *note Availability: 2128.: not WASI.

 -- Funzione: socket.getnameinfo (sockaddr, flags)

     Translate a socket address 'sockaddr' into a 2-tuple ‘(host,
     port)’.  Depending on the settings of 'flags', the result can
     contain a fully qualified domain name or numeric address
     representation in 'host'.  Similarly, 'port' can contain a string
     port name or a numeric port number.

     For IPv6 addresses, ‘%scope_id’ is appended to the host part if
     'sockaddr' contains meaningful 'scope_id'.  Usually this happens
     for multicast addresses.

     For more information about 'flags' you can consult
     ‘getnameinfo(3)(2)’.

     Raises an *note auditing event: 1c56. ‘socket.getnameinfo’ with
     argument ‘sockaddr’.

     *note Availability: 2128.: not WASI.

 -- Funzione: socket.getprotobyname (protocolname)

     Translate an internet protocol name (for example, ‘'icmp'’) to a
     constant suitable for passing as the (optional) third argument to
     the *note socket(): fa3. function.  This is usually only needed for
     sockets opened in «raw» mode (*note SOCK_RAW: 393d.); for the
     normal socket modes, the correct protocol is chosen automatically
     if the protocol is omitted or zero.

     *note Availability: 2128.: not WASI.

 -- Funzione: socket.getservbyname (servicename[, protocolname])

     Translate an internet service name and protocol name to a port
     number for that service.  The optional protocol name, if given,
     should be ‘'tcp'’ or ‘'udp'’, otherwise any protocol will match.

     Raises an *note auditing event: 1c56. ‘socket.getservbyname’ with
     arguments ‘servicename’, ‘protocolname’.

     *note Availability: 2128.: not WASI.

 -- Funzione: socket.getservbyport (port[, protocolname])

     Translate an internet port number and protocol name to a service
     name for that service.  The optional protocol name, if given,
     should be ‘'tcp'’ or ‘'udp'’, otherwise any protocol will match.

     Raises an *note auditing event: 1c56. ‘socket.getservbyport’ with
     arguments ‘port’, ‘protocolname’.

     *note Availability: 2128.: not WASI.

 -- Funzione: socket.ntohl (x)

     Convert 32-bit positive integers from network to host byte order.
     On machines where the host byte order is the same as network byte
     order, this is a no-op; otherwise, it performs a 4-byte swap
     operation.

 -- Funzione: socket.ntohs (x)

     Convert 16-bit positive integers from network to host byte order.
     On machines where the host byte order is the same as network byte
     order, this is a no-op; otherwise, it performs a 2-byte swap
     operation.

     Cambiato nella versione 3.10: Raises *note OverflowError: a83. if
     'x' does not fit in a 16-bit unsigned integer.

 -- Funzione: socket.htonl (x)

     Convert 32-bit positive integers from host to network byte order.
     On machines where the host byte order is the same as network byte
     order, this is a no-op; otherwise, it performs a 4-byte swap
     operation.

 -- Funzione: socket.htons (x)

     Convert 16-bit positive integers from host to network byte order.
     On machines where the host byte order is the same as network byte
     order, this is a no-op; otherwise, it performs a 2-byte swap
     operation.

     Cambiato nella versione 3.10: Raises *note OverflowError: a83. if
     'x' does not fit in a 16-bit unsigned integer.

 -- Funzione: socket.inet_aton (ip_string)

     Convert an IPv4 address from dotted-quad string format (for
     example, “123.45.67.89”) to 32-bit packed binary format, as a bytes
     object four characters in length.  This is useful when conversing
     with a program that uses the standard C library and needs objects
     of type ‘in_addr’, which is the C type for the 32-bit packed binary
     this function returns.

     *note inet_aton(): b5c. also accepts strings with less than three
     dots; see the Unix manual page ‘inet(3)(3)’ for details.

     If the IPv4 address string passed to this function is invalid,
     *note OSError: 2c0. will be raised.  Note that exactly what is
     valid depends on the underlying C implementation of ‘inet_aton()’.

     *note inet_aton(): b5c. does not support IPv6, and *note
     inet_pton(): b5d. should be used instead for IPv4/v6 dual stack
     support.

 -- Funzione: socket.inet_ntoa (packed_ip)

     Convert a 32-bit packed IPv4 address (a *note bytes-like object:
     193. four bytes in length) to its standard dotted-quad string
     representation (for example, “123.45.67.89”).  This is useful when
     conversing with a program that uses the standard C library and
     needs objects of type ‘in_addr’, which is the C type for the 32-bit
     packed binary data this function takes as an argument.

     If the byte sequence passed to this function is not exactly 4 bytes
     in length, *note OSError: 2c0. will be raised.  *note inet_ntoa():
     3982. does not support IPv6, and *note inet_ntop(): 11a7. should be
     used instead for IPv4/v6 dual stack support.

     Cambiato nella versione 3.5: Writable *note bytes-like object: 193.
     is now accepted.

 -- Funzione: socket.inet_pton (address_family, ip_string)

     Convert an IP address from its family-specific string format to a
     packed, binary format.  *note inet_pton(): b5d. is useful when a
     library or network protocol calls for an object of type ‘in_addr’
     (similar to *note inet_aton(): b5c.) or ‘in6_addr’.

     Supported values for 'address_family' are currently *note AF_INET:
     1b95. and *note AF_INET6: 1b96.  If the IP address string
     'ip_string' is invalid, *note OSError: 2c0. will be raised.  Note
     that exactly what is valid depends on both the value of
     'address_family' and the underlying implementation of
     ‘inet_pton()’.

     *note Availability: 2128.: Unix, Windows.

     Cambiato nella versione 3.4: Windows support added

 -- Funzione: socket.inet_ntop (address_family, packed_ip)

     Convert a packed IP address (a *note bytes-like object: 193. of
     some number of bytes) to its standard, family-specific string
     representation (for example, ‘'7.10.0.5'’ or ‘'5aef:2b::8'’).
     *note inet_ntop(): 11a7. is useful when a library or network
     protocol returns an object of type ‘in_addr’ (similar to *note
     inet_ntoa(): 3982.) or ‘in6_addr’.

     Supported values for 'address_family' are currently *note AF_INET:
     1b95. and *note AF_INET6: 1b96.  If the bytes object 'packed_ip' is
     not the correct length for the specified address family, *note
     ValueError: 2ec. will be raised.  *note OSError: 2c0. is raised for
     errors from the call to *note inet_ntop(): 11a7.

     *note Availability: 2128.: Unix, Windows.

     Cambiato nella versione 3.4: Windows support added

     Cambiato nella versione 3.5: Writable *note bytes-like object: 193.
     is now accepted.

 -- Funzione: socket.CMSG_LEN (length)

     Return the total length, without trailing padding, of an ancillary
     data item with associated data of the given 'length'.  This value
     can often be used as the buffer size for *note recvmsg(): fa8. to
     receive a single item of ancillary data, but RFC 3542(4) requires
     portable applications to use *note CMSG_SPACE(): 1dff. and thus
     include space for padding, even when the item will be the last in
     the buffer.  Raises *note OverflowError: a83. if 'length' is
     outside the permissible range of values.

     *note Availability: 2128.: Unix, not WASI.

     Most Unix platforms.

     Added in version 3.3.

 -- Funzione: socket.CMSG_SPACE (length)

     Return the buffer size needed for *note recvmsg(): fa8. to receive
     an ancillary data item with associated data of the given 'length',
     along with any trailing padding.  The buffer space needed to
     receive multiple items is the sum of the *note CMSG_SPACE(): 1dff.
     values for their associated data lengths.  Raises *note
     OverflowError: a83. if 'length' is outside the permissible range of
     values.

     Note that some systems might support ancillary data without
     providing this function.  Also note that setting the buffer size
     using the results of this function may not precisely limit the
     amount of ancillary data that can be received, since additional
     data may be able to fit into the padding area.

     *note Availability: 2128.: Unix, not WASI.

     most Unix platforms.

     Added in version 3.3.

 -- Funzione: socket.getdefaulttimeout ()

     Return the default timeout in seconds (float) for new socket
     objects.  A value of ‘None’ indicates that new socket objects have
     no timeout.  When the socket module is first imported, the default
     is ‘None’.

 -- Funzione: socket.setdefaulttimeout (timeout)

     Set the default timeout in seconds (float) for new socket objects.
     When the socket module is first imported, the default is ‘None’.
     See *note settimeout(): 3937. for possible values and their
     respective meanings.

 -- Funzione: socket.sethostname (name)

     Set the machine’s hostname to 'name'.  This will raise an *note
     OSError: 2c0. if you don’t have enough rights.

     Raises an *note auditing event: 1c56. ‘socket.sethostname’ with
     argument ‘name’.

     *note Availability: 2128.: Unix, not Android.

     Added in version 3.3.

 -- Funzione: socket.if_nameindex ()

     Return a list of network interface information (index int, name
     string) tuples.  *note OSError: 2c0. if the system call fails.

     *note Availability: 2128.: Unix, Windows, not WASI.

     Added in version 3.3.

     Cambiato nella versione 3.8: Windows support was added.

          Nota: On Windows network interfaces have different names in
          different contexts (all names are examples):

             * UUID: ‘{FB605B73-AAC2-49A6-9A2F-25416AEA0573}’

             * name: ‘ethernet_32770’

             * friendly name: ‘vEthernet (nat)’

             * description: ‘Hyper-V Virtual Ethernet Adapter’

          This function returns names of the second form from the list,
          ‘ethernet_32770’ in this example case.

 -- Funzione: socket.if_nametoindex (if_name)

     Return a network interface index number corresponding to an
     interface name.  *note OSError: 2c0. if no interface with the given
     name exists.

     *note Availability: 2128.: Unix, Windows, not WASI.

     Added in version 3.3.

     Cambiato nella versione 3.8: Windows support was added.

     Vedi anche
     ..........

     «Interface name» is a name as documented in *note if_nameindex():
     c24.

 -- Funzione: socket.if_indextoname (if_index)

     Return a network interface name corresponding to an interface index
     number.  *note OSError: 2c0. if no interface with the given index
     exists.

     *note Availability: 2128.: Unix, Windows, not WASI.

     Added in version 3.3.

     Cambiato nella versione 3.8: Windows support was added.

     Vedi anche
     ..........

     «Interface name» is a name as documented in *note if_nameindex():
     c24.

 -- Funzione: socket.send_fds (sock, buffers, fds[, flags[, address]])

     Send the list of file descriptors 'fds' over an *note AF_UNIX:
     1b98. socket 'sock'.  The 'fds' parameter is a sequence of file
     descriptors.  Consult *note sendmsg(): 6a2. for the documentation
     of these parameters.

     *note Availability: 2128.: Unix, not WASI.

     Unix platforms supporting *note sendmsg(): 6a2. and ‘SCM_RIGHTS’
     mechanism.

     Added in version 3.9.

 -- Funzione: socket.recv_fds (sock, bufsize, maxfds[, flags])

     Receive up to 'maxfds' file descriptors from an *note AF_UNIX:
     1b98. socket 'sock'.  Return ‘(msg, list(fds), flags, addr)’.
     Consult *note recvmsg(): fa8. for the documentation of these
     parameters.

     *note Availability: 2128.: Unix, not WASI.

     Unix platforms supporting *note recvmsg(): fa8. and ‘SCM_RIGHTS’
     mechanism.

     Added in version 3.9.

          Nota: Any truncated integers at the end of the list of file
          descriptors.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Happy_Eyeballs

   (2) https://manpages.debian.org/getnameinfo(3)

   (3) https://manpages.debian.org/inet(3)

   (4) https://datatracker.ietf.org/doc/html/rfc3542.html


File: python.info,  Node: Socket Objects,  Next: Notes on socket timeouts,  Prev: Module contents,  Up: socket — Low-level networking interface

5.19.2.8 Socket Objects
.......................

Socket objects have the following methods.  Except for *note makefile():
13a7, these correspond to Unix system calls applicable to sockets.

Cambiato nella versione 3.2: Support for the *note context manager: 1e1.
protocol was added.  Exiting the context manager is equivalent to
calling *note close(): d6c.

 -- Metodo: socket.accept ()

     Accept a connection.  The socket must be bound to an address and
     listening for connections.  The return value is a pair ‘(conn,
     address)’ where 'conn' is a 'new' socket object usable to send and
     receive data on the connection, and 'address' is the address bound
     to the socket on the other end of the connection.

     The newly created socket is *note non-inheritable: 10fe.

     Cambiato nella versione 3.4: The socket is now non-inheritable.

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the method now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(1) for the
     rationale).

 -- Metodo: socket.bind (address)

     Bind the socket to 'address'.  The socket must not already be
     bound.  (The format of 'address' depends on the address family —
     see above.)

     Raises an *note auditing event: 1c56. ‘socket.bind’ with arguments
     ‘self’, ‘address’.

     *note Availability: 2128.: not WASI.

 -- Metodo: socket.close ()

     Mark the socket closed.  The underlying system resource (e.g.  a
     file descriptor) is also closed when all file objects from *note
     makefile(): 13a7. are closed.  Once that happens, all future
     operations on the socket object will fail.  The remote end will
     receive no more data (after queued data is flushed).

     Sockets are automatically closed when they are garbage-collected,
     but it is recommended to *note close(): d6c. them explicitly, or to
     use a *note with: 186. statement around them.

     Cambiato nella versione 3.6: *note OSError: 2c0. is now raised if
     an error occurs when the underlying ‘close()’ call is made.

          Nota: *note close(): d6c. releases the resource associated
          with a connection but does not necessarily close the
          connection immediately.  If you want to close the connection
          in a timely fashion, call *note shutdown(): 3974. before *note
          close(): d6c.

 -- Metodo: socket.connect (address)

     Connect to a remote socket at 'address'.  (The format of 'address'
     depends on the address family — see above.)

     If the connection is interrupted by a signal, the method waits
     until the connection completes, or raise a *note TimeoutError: a38.
     on timeout, if the signal handler doesn’t raise an exception and
     the socket is blocking or has a timeout.  For non-blocking sockets,
     the method raises an *note InterruptedError: f8a. exception if the
     connection is interrupted by a signal (or the exception raised by
     the signal handler).

     Raises an *note auditing event: 1c56. ‘socket.connect’ with
     arguments ‘self’, ‘address’.

     Cambiato nella versione 3.5: The method now waits until the
     connection completes instead of raising an *note InterruptedError:
     f8a. exception if the connection is interrupted by a signal, the
     signal handler doesn’t raise an exception and the socket is
     blocking or has a timeout (see the PEP 475(2) for the rationale).

     *note Availability: 2128.: not WASI.

 -- Metodo: socket.connect_ex (address)

     Like ‘connect(address)’, but return an error indicator instead of
     raising an exception for errors returned by the C-level ‘connect()’
     call (other problems, such as «host not found,» can still raise
     exceptions).  The error indicator is ‘0’ if the operation
     succeeded, otherwise the value of the ‘errno’ variable.  This is
     useful to support, for example, asynchronous connects.

     Raises an *note auditing event: 1c56. ‘socket.connect’ with
     arguments ‘self’, ‘address’.

     *note Availability: 2128.: not WASI.

 -- Metodo: socket.detach ()

     Put the socket object into closed state without actually closing
     the underlying file descriptor.  The file descriptor is returned,
     and can be reused for other purposes.

     Added in version 3.2.

 -- Metodo: socket.dup ()

     Duplicate the socket.

     The newly created socket is *note non-inheritable: 10fe.

     Cambiato nella versione 3.4: The socket is now non-inheritable.

     *note Availability: 2128.: not WASI.

 -- Metodo: socket.fileno ()

     Return the socket’s file descriptor (a small integer), or -1 on
     failure.  This is useful with *note select.select(): fa2.

     Under Windows the small integer returned by this method cannot be
     used where a file descriptor can be used (such as *note
     os.fdopen(): 2367.).  Unix does not have this limitation.

 -- Metodo: socket.get_inheritable ()

     Get the *note inheritable flag: 10fe. of the socket’s file
     descriptor or socket’s handle: ‘True’ if the socket can be
     inherited in child processes, ‘False’ if it cannot.

     Added in version 3.4.

 -- Metodo: socket.getpeername ()

     Return the remote address to which the socket is connected.  This
     is useful to find out the port number of a remote IPv4/v6 socket,
     for instance.  (The format of the address returned depends on the
     address family — see above.)  On some systems this function is not
     supported.

 -- Metodo: socket.getsockname ()

     Return the socket’s own address.  This is useful to find out the
     port number of an IPv4/v6 socket, for instance.  (The format of the
     address returned depends on the address family — see above.)

 -- Metodo: socket.getsockopt (level, optname[, buflen])

     Return the value of the given socket option (see the Unix man page
     ‘getsockopt(2)(3)’).  The needed symbolic constants (*note SO_*
     etc.: d6e.) are defined in this module.  If 'buflen' is absent, an
     integer option is assumed and its integer value is returned by the
     function.  If 'buflen' is present, it specifies the maximum length
     of the buffer used to receive the option in, and this buffer is
     returned as a bytes object.  It is up to the caller to decode the
     contents of the buffer (see the optional built-in module *note
     struct: db. for a way to decode C structures encoded as byte
     strings).

     *note Availability: 2128.: not WASI.

 -- Metodo: socket.getblocking ()

     Return ‘True’ if socket is in blocking mode, ‘False’ if in
     non-blocking.

     This is equivalent to checking ‘socket.gettimeout() != 0’.

     Added in version 3.7.

 -- Metodo: socket.gettimeout ()

     Return the timeout in seconds (float) associated with socket
     operations, or ‘None’ if no timeout is set.  This reflects the last
     call to *note setblocking(): 3021. or *note settimeout(): 3937.

 -- Metodo: socket.ioctl (control, option)

     The *note ioctl(): ed0. method is a limited interface to the
     WSAIoctl system interface.  Please refer to the Win32
     documentation(4) for more information.

     On other platforms, the generic *note fcntl.fcntl(): 1839. and
     *note fcntl.ioctl(): 1682. functions may be used; they accept a
     socket object as their first argument.

     Currently only the following control codes are supported:
     ‘SIO_RCVALL’, ‘SIO_KEEPALIVE_VALS’, and ‘SIO_LOOPBACK_FAST_PATH’.

     *note Availability: 2128.: Windows

     Cambiato nella versione 3.6: ‘SIO_LOOPBACK_FAST_PATH’ was added.

 -- Metodo: socket.listen ([backlog])

     Enable a server to accept connections.  If 'backlog' is specified,
     it must be at least 0 (if it is lower, it is set to 0); it
     specifies the number of unaccepted connections that the system will
     allow before refusing new connections.  If not specified, a default
     reasonable value is chosen.

     *note Availability: 2128.: not WASI.

     Cambiato nella versione 3.5: The 'backlog' parameter is now
     optional.

 -- Metodo: socket.makefile (mode='r', buffering=None, *, encoding=None,
          errors=None, newline=None)

     Return a *note file object: 13cb. associated with the socket.  The
     exact returned type depends on the arguments given to *note
     makefile(): 13a7.  These arguments are interpreted the same way as
     by the built-in *note open(): 316. function, except the only
     supported 'mode' values are ‘'r'’ (default), ‘'w'’, ‘'b'’, or a
     combination of those.

     The socket must be in blocking mode; it can have a timeout, but the
     file object’s internal buffer may end up in an inconsistent state
     if a timeout occurs.

     Closing the file object returned by *note makefile(): 13a7. won’t
     close the original socket unless all other file objects have been
     closed and *note socket.close(): d6c. has been called on the socket
     object.

          Nota: On Windows, the file-like object created by *note
          makefile(): 13a7. cannot be used where a file object with a
          file descriptor is expected, such as the stream arguments of
          *note subprocess.Popen(): 4b8.

 -- Metodo: socket.recv (bufsize[, flags])

     Receive data from the socket.  The return value is a bytes object
     representing the data received.  The maximum amount of data to be
     received at once is specified by 'bufsize'.  A returned empty bytes
     object indicates that the client has disconnected.  See the Unix
     manual page ‘recv(2)(5)’ for the meaning of the optional argument
     'flags'; it defaults to zero.

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the method now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(6) for the
     rationale).

 -- Metodo: socket.recvfrom (bufsize[, flags])

     Receive data from the socket.  The return value is a pair ‘(bytes,
     address)’ where 'bytes' is a bytes object representing the data
     received and 'address' is the address of the socket sending the
     data.  See the Unix manual page ‘recv(2)(7)’ for the meaning of the
     optional argument 'flags'; it defaults to zero.  (The format of
     'address' depends on the address family — see above.)

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the method now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(8) for the
     rationale).

     Cambiato nella versione 3.7: For multicast IPv6 address, first item
     of 'address' does not contain ‘%scope_id’ part anymore.  In order
     to get full IPv6 address use *note getnameinfo(): 1a22.

 -- Metodo: socket.recvmsg (bufsize[, ancbufsize[, flags]])

     Receive normal data (up to 'bufsize' bytes) and ancillary data from
     the socket.  The 'ancbufsize' argument sets the size in bytes of
     the internal buffer used to receive the ancillary data; it defaults
     to 0, meaning that no ancillary data will be received.  Appropriate
     buffer sizes for ancillary data can be calculated using *note
     CMSG_SPACE(): 1dff. or *note CMSG_LEN(): 1e00, and items which do
     not fit into the buffer might be truncated or discarded.  The
     'flags' argument defaults to 0 and has the same meaning as for
     *note recv(): fa6.

     The return value is a 4-tuple: ‘(data, ancdata, msg_flags,
     address)’.  The 'data' item is a *note bytes: 192. object holding
     the non-ancillary data received.  The 'ancdata' item is a list of
     zero or more tuples ‘(cmsg_level, cmsg_type, cmsg_data)’
     representing the ancillary data (control messages) received:
     'cmsg_level' and 'cmsg_type' are integers specifying the protocol
     level and protocol-specific type respectively, and 'cmsg_data' is a
     *note bytes: 192. object holding the associated data.  The
     'msg_flags' item is the bitwise OR of various flags indicating
     conditions on the received message; see your system documentation
     for details.  If the receiving socket is unconnected, 'address' is
     the address of the sending socket, if available; otherwise, its
     value is unspecified.

     On some systems, *note sendmsg(): 6a2. and *note recvmsg(): fa8.
     can be used to pass file descriptors between processes over an
     *note AF_UNIX: 1b98. socket.  When this facility is used (it is
     often restricted to *note SOCK_STREAM: 14fb. sockets), *note
     recvmsg(): fa8. will return, in its ancillary data, items of the
     form ‘(socket.SOL_SOCKET, socket.SCM_RIGHTS, fds)’, where 'fds' is
     a *note bytes: 192. object representing the new file descriptors as
     a binary array of the native C int type.  If *note recvmsg(): fa8.
     raises an exception after the system call returns, it will first
     attempt to close any file descriptors received via this mechanism.

     Some systems do not indicate the truncated length of ancillary data
     items which have been only partially received.  If an item appears
     to extend beyond the end of the buffer, *note recvmsg(): fa8. will
     issue a *note RuntimeWarning: 4d8, and will return the part of it
     which is inside the buffer provided it has not been truncated
     before the start of its associated data.

     On systems which support the ‘SCM_RIGHTS’ mechanism, the following
     function will receive up to 'maxfds' file descriptors, returning
     the message data and a list containing the descriptors (while
     ignoring unexpected conditions such as unrelated control messages
     being received).  See also *note sendmsg(): 6a2.

          import socket, array

          def recv_fds(sock, msglen, maxfds):
              fds = array.array("i")   # Array of ints
              msg, ancdata, flags, addr = sock.recvmsg(msglen, socket.CMSG_LEN(maxfds * fds.itemsize))
              for cmsg_level, cmsg_type, cmsg_data in ancdata:
                  if cmsg_level == socket.SOL_SOCKET and cmsg_type == socket.SCM_RIGHTS:
                      # Append data, ignoring any truncated integers at the end.
                      fds.frombytes(cmsg_data[:len(cmsg_data) - (len(cmsg_data) % fds.itemsize)])
              return msg, list(fds)

     *note Availability: 2128.: Unix.

     Most Unix platforms.

     Added in version 3.3.

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the method now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(9) for the
     rationale).

 -- Metodo: socket.recvmsg_into (buffers[, ancbufsize[, flags]])

     Receive normal data and ancillary data from the socket, behaving as
     *note recvmsg(): fa8. would, but scatter the non-ancillary data
     into a series of buffers instead of returning a new bytes object.
     The 'buffers' argument must be an iterable of objects that export
     writable buffers (e.g.  *note bytearray: 344. objects); these will
     be filled with successive chunks of the non-ancillary data until it
     has all been written or there are no more buffers.  The operating
     system may set a limit (*note sysconf(): 18d5. value ‘SC_IOV_MAX’)
     on the number of buffers that can be used.  The 'ancbufsize' and
     'flags' arguments have the same meaning as for *note recvmsg():
     fa8.

     The return value is a 4-tuple: ‘(nbytes, ancdata, msg_flags,
     address)’, where 'nbytes' is the total number of bytes of
     non-ancillary data written into the buffers, and 'ancdata',
     'msg_flags' and 'address' are the same as for *note recvmsg(): fa8.

     Example:

          >>> import socket
          >>> s1, s2 = socket.socketpair()
          >>> b1 = bytearray(b'----')
          >>> b2 = bytearray(b'0123456789')
          >>> b3 = bytearray(b'--------------')
          >>> s1.send(b'Mary had a little lamb')
          22
          >>> s2.recvmsg_into([b1, memoryview(b2)[2:9], b3])
          (22, [], 0, None)
          >>> [b1, b2, b3]
          [bytearray(b'Mary'), bytearray(b'01 had a 9'), bytearray(b'little lamb---')]

     *note Availability: 2128.: Unix.

     Most Unix platforms.

     Added in version 3.3.

 -- Metodo: socket.recvfrom_into (buffer[, nbytes[, flags]])

     Receive data from the socket, writing it into 'buffer' instead of
     creating a new bytestring.  The return value is a pair ‘(nbytes,
     address)’ where 'nbytes' is the number of bytes received and
     'address' is the address of the socket sending the data.  See the
     Unix manual page ‘recv(2)(10)’ for the meaning of the optional
     argument 'flags'; it defaults to zero.  (The format of 'address'
     depends on the address family — see above.)

 -- Metodo: socket.recv_into (buffer[, nbytes[, flags]])

     Receive up to 'nbytes' bytes from the socket, storing the data into
     a buffer rather than creating a new bytestring.  If 'nbytes' is not
     specified (or 0), receive up to the size available in the given
     buffer.  Returns the number of bytes received.  See the Unix manual
     page ‘recv(2)(11)’ for the meaning of the optional argument
     'flags'; it defaults to zero.

 -- Metodo: socket.send (bytes[, flags])

     Send data to the socket.  The socket must be connected to a remote
     socket.  The optional 'flags' argument has the same meaning as for
     *note recv(): fa6. above.  Returns the number of bytes sent.
     Applications are responsible for checking that all data has been
     sent; if only some of the data was transmitted, the application
     needs to attempt delivery of the remaining data.  For further
     information on this topic, consult the *note Socket Programming
     HOWTO: 3987.

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the method now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(12) for the
     rationale).

 -- Metodo: socket.sendall (bytes[, flags])

     Send data to the socket.  The socket must be connected to a remote
     socket.  The optional 'flags' argument has the same meaning as for
     *note recv(): fa6. above.  Unlike *note send(): fa9, this method
     continues to send data from 'bytes' until either all data has been
     sent or an error occurs.  ‘None’ is returned on success.  On error,
     an exception is raised, and there is no way to determine how much
     data, if any, was successfully sent.

     Cambiato nella versione 3.5: The socket timeout is no longer reset
     each time data is sent successfully.  The socket timeout is now the
     maximum total duration to send all data.

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the method now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(13) for the
     rationale).

 -- Metodo: socket.sendto (bytes, address)

 -- Metodo: socket.sendto (bytes, flags, address)

     Send data to the socket.  The socket should not be connected to a
     remote socket, since the destination socket is specified by
     'address'.  The optional 'flags' argument has the same meaning as
     for *note recv(): fa6. above.  Return the number of bytes sent.
     (The format of 'address' depends on the address family — see
     above.)

     Raises an *note auditing event: 1c56. ‘socket.sendto’ with
     arguments ‘self’, ‘address’.

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the method now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(14) for the
     rationale).

 -- Metodo: socket.sendmsg (buffers[, ancdata[, flags[, address]]])

     Send normal and ancillary data to the socket, gathering the
     non-ancillary data from a series of buffers and concatenating it
     into a single message.  The 'buffers' argument specifies the
     non-ancillary data as an iterable of *note bytes-like objects: 193.
     (e.g.  *note bytes: 192. objects); the operating system may set a
     limit (*note sysconf(): 18d5. value ‘SC_IOV_MAX’) on the number of
     buffers that can be used.  The 'ancdata' argument specifies the
     ancillary data (control messages) as an iterable of zero or more
     tuples ‘(cmsg_level, cmsg_type, cmsg_data)’, where 'cmsg_level' and
     'cmsg_type' are integers specifying the protocol level and
     protocol-specific type respectively, and 'cmsg_data' is a
     bytes-like object holding the associated data.  Note that some
     systems (in particular, systems without *note CMSG_SPACE(): 1dff.)
     might support sending only one control message per call.  The
     'flags' argument defaults to 0 and has the same meaning as for
     *note send(): fa9.  If 'address' is supplied and not ‘None’, it
     sets a destination address for the message.  The return value is
     the number of bytes of non-ancillary data sent.

     The following function sends the list of file descriptors 'fds'
     over an *note AF_UNIX: 1b98. socket, on systems which support the
     ‘SCM_RIGHTS’ mechanism.  See also *note recvmsg(): fa8.

          import socket, array

          def send_fds(sock, msg, fds):
              return sock.sendmsg([msg], [(socket.SOL_SOCKET, socket.SCM_RIGHTS, array.array("i", fds))])

     *note Availability: 2128.: Unix, not WASI.

     Most Unix platforms.

     Raises an *note auditing event: 1c56. ‘socket.sendmsg’ with
     arguments ‘self’, ‘address’.

     Added in version 3.3.

     Cambiato nella versione 3.5: If the system call is interrupted and
     the signal handler does not raise an exception, the method now
     retries the system call instead of raising an *note
     InterruptedError: f8a. exception (see PEP 475(15) for the
     rationale).

 -- Metodo: socket.sendmsg_afalg ([msg], *, op[, iv[, assoclen[,
          flags]]])

     Specialized version of *note sendmsg(): 6a2. for *note AF_ALG: ed4.
     socket.  Set mode, IV, AEAD associated data length and flags for
     *note AF_ALG: ed4. socket.

     *note Availability: 2128.: Linux >= 2.6.38.

     Added in version 3.6.

 -- Metodo: socket.sendfile (file, offset=0, count=None)

     Send a file until EOF is reached by using high-performance *note
     os.sendfile: d07. and return the total number of bytes which were
     sent.  'file' must be a regular file object opened in binary mode.
     If *note os.sendfile: d07. is not available (e.g.  Windows) or
     'file' is not a regular file *note send(): fa9. will be used
     instead.  'offset' tells from where to start reading the file.  If
     specified, 'count' is the total number of bytes to transmit as
     opposed to sending the file until EOF is reached.  File position is
     updated on return or also in case of error in which case *note
     file.tell(): 15b4. can be used to figure out the number of bytes
     which were sent.  The socket must be of *note SOCK_STREAM: 14fb.
     type.  Non-blocking sockets are not supported.

     Added in version 3.5.

 -- Metodo: socket.set_inheritable (inheritable)

     Set the *note inheritable flag: 10fe. of the socket’s file
     descriptor or socket’s handle.

     Added in version 3.4.

 -- Metodo: socket.setblocking (flag)

     Set blocking or non-blocking mode of the socket: if 'flag' is
     false, the socket is set to non-blocking, else to blocking mode.

     This method is a shorthand for certain *note settimeout(): 3937.
     calls:

        * ‘sock.setblocking(True)’ is equivalent to
          ‘sock.settimeout(None)’

        * ‘sock.setblocking(False)’ is equivalent to
          ‘sock.settimeout(0.0)’

     Cambiato nella versione 3.7: The method no longer applies *note
     SOCK_NONBLOCK: e06. flag on *note socket.type: e08.

 -- Metodo: socket.settimeout (value)

     Set a timeout on blocking socket operations.  The 'value' argument
     can be a nonnegative floating-point number expressing seconds, or
     ‘None’.  If a non-zero value is given, subsequent socket operations
     will raise a *note timeout: a37. exception if the timeout period
     'value' has elapsed before the operation has completed.  If zero is
     given, the socket is put in non-blocking mode.  If ‘None’ is given,
     the socket is put in blocking mode.

     For further information, please consult the *note notes on socket
     timeouts: 3988.

     Cambiato nella versione 3.7: The method no longer toggles *note
     SOCK_NONBLOCK: e06. flag on *note socket.type: e08.

 -- Metodo: socket.setsockopt (level, optname, value: int | Buffer)

 -- Metodo: socket.setsockopt (level, optname, None, optlen: int)

     Set the value of the given socket option (see the Unix manual page
     ‘setsockopt(2)(16)’).  The needed symbolic constants are defined in
     this module (SO_* etc.  <socket-unix-constants>).  The value can be
     an integer, ‘None’ or a *note bytes-like object: 193. representing
     a buffer.  In the later case it is up to the caller to ensure that
     the bytestring contains the proper bits (see the optional built-in
     module *note struct: db. for a way to encode C structures as
     bytestrings).  When 'value' is set to ‘None’, 'optlen' argument is
     required.  It’s equivalent to call ‘setsockopt()’ C function with
     ‘optval=NULL’ and ‘optlen=optlen’.

     Cambiato nella versione 3.5: Writable *note bytes-like object: 193.
     is now accepted.

     Cambiato nella versione 3.6: setsockopt(level, optname, None,
     optlen: int) form added.

     *note Availability: 2128.: not WASI.

 -- Metodo: socket.shutdown (how)

     Shut down one or both halves of the connection.  If 'how' is *note
     SHUT_RD: 3971, further receives are disallowed.  If 'how' is *note
     SHUT_WR: 3972, further sends are disallowed.  If 'how' is *note
     SHUT_RDWR: 3973, further sends and receives are disallowed.

     *note Availability: 2128.: not WASI.

 -- Metodo: socket.share (process_id)

     Duplicate a socket and prepare it for sharing with a target
     process.  The target process must be provided with 'process_id'.
     The resulting bytes object can then be passed to the target process
     using some form of interprocess communication and the socket can be
     recreated there using *note fromshare(): e03.  Once this method has
     been called, it is safe to close the socket since the operating
     system has already duplicated it for the target process.

     *note Availability: 2128.: Windows.

     Added in version 3.3.

Note that there are no methods ‘read()’ or ‘write()’; use *note recv():
fa6. and *note send(): fa9. without 'flags' argument instead.

Socket objects also have these (read-only) attributes that correspond to
the values given to the *note socket: fa3. constructor.

 -- Attributo: socket.family

     The socket family.

 -- Attributo: socket.type

     The socket type.

 -- Attributo: socket.proto

     The socket protocol.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0475/

   (2) https://peps.python.org/pep-0475/

   (3) https://manpages.debian.org/getsockopt(2)

   (4) https://msdn.microsoft.com/en-us/library/ms741621%28VS.85%29.aspx

   (5) https://manpages.debian.org/recv(2)

   (6) https://peps.python.org/pep-0475/

   (7) https://manpages.debian.org/recv(2)

   (8) https://peps.python.org/pep-0475/

   (9) https://peps.python.org/pep-0475/

   (10) https://manpages.debian.org/recv(2)

   (11) https://manpages.debian.org/recv(2)

   (12) https://peps.python.org/pep-0475/

   (13) https://peps.python.org/pep-0475/

   (14) https://peps.python.org/pep-0475/

   (15) https://peps.python.org/pep-0475/

   (16) https://manpages.debian.org/setsockopt(2)


File: python.info,  Node: Notes on socket timeouts,  Next: Example<7>,  Prev: Socket Objects,  Up: socket — Low-level networking interface

5.19.2.9 Notes on socket timeouts
.................................

A socket object can be in one of three modes: blocking, non-blocking, or
timeout.  Sockets are by default always created in blocking mode, but
this can be changed by calling *note setdefaulttimeout(): 393b.

   * In 'blocking mode', operations block until complete or the system
     returns an error (such as connection timed out).

   * In 'non-blocking mode', operations fail (with an error that is
     unfortunately system-dependent) if they cannot be completed
     immediately: functions from the *note select: c6. module can be
     used to know when and whether a socket is available for reading or
     writing.

   * In 'timeout mode', operations fail if they cannot be completed
     within the timeout specified for the socket (they raise a *note
     timeout: a37. exception) or if the system returns an error.

     Nota: At the operating system level, sockets in 'timeout mode' are
     internally set in non-blocking mode.  Also, the blocking and
     timeout modes are shared between file descriptors and socket
     objects that refer to the same network endpoint.  This
     implementation detail can have visible consequences if e.g.  you
     decide to use the *note fileno(): 3985. of a socket.

* Menu:

* Timeouts and the connect method::
* Timeouts and the accept method::


File: python.info,  Node: Timeouts and the connect method,  Next: Timeouts and the accept method,  Up: Notes on socket timeouts

5.19.2.10 Timeouts and the ‘connect’ method
...........................................

The *note connect(): fa5. operation is also subject to the timeout
setting, and in general it is recommended to call *note settimeout():
3937. before calling *note connect(): fa5. or pass a timeout parameter
to *note create_connection(): 883.  However, the system network stack
may also return a connection timeout error of its own regardless of any
Python socket timeout setting.


File: python.info,  Node: Timeouts and the accept method,  Prev: Timeouts and the connect method,  Up: Notes on socket timeouts

5.19.2.11 Timeouts and the ‘accept’ method
..........................................

If *note getdefaulttimeout(): 3979. is not *note None: 886, sockets
returned by the *note accept(): fa4. method inherit that timeout.
Otherwise, the behaviour depends on settings of the listening socket:

   * if the listening socket is in 'blocking mode' or in 'timeout mode',
     the socket returned by *note accept(): fa4. is in 'blocking mode';

   * if the listening socket is in 'non-blocking mode', whether the
     socket returned by *note accept(): fa4. is in blocking or
     non-blocking mode is operating system-dependent.  If you want to
     ensure cross-platform behaviour, it is recommended you manually
     override this setting.


File: python.info,  Node: Example<7>,  Prev: Notes on socket timeouts,  Up: socket — Low-level networking interface

5.19.2.12 Example
.................

Here are four minimal example programs using the TCP/IP protocol: a
server that echoes all data that it receives back (servicing only one
client), and a client using it.  Note that a server must perform the
sequence *note socket(): fa3, *note bind(): 1741, *note listen(): 1060,
*note accept(): fa4. (possibly repeating the *note accept(): fa4. to
service more than one client), while a client only needs the sequence
*note socket(): fa3, *note connect(): fa5.  Also note that the server
does not *note sendall(): faa./*note recv(): fa6. on the socket it is
listening on but on the new socket returned by *note accept(): fa4.

The first two examples support IPv4 only.

     # Echo server program
     import socket

     HOST = ''                 # Symbolic name meaning all available interfaces
     PORT = 50007              # Arbitrary non-privileged port
     with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
         s.bind((HOST, PORT))
         s.listen(1)
         conn, addr = s.accept()
         with conn:
             print('Connected by', addr)
             while True:
                 data = conn.recv(1024)
                 if not data: break
                 conn.sendall(data)

     # Echo client program
     import socket

     HOST = 'daring.cwi.nl'    # The remote host
     PORT = 50007              # The same port as used by the server
     with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
         s.connect((HOST, PORT))
         s.sendall(b'Hello, world')
         data = s.recv(1024)
     print('Received', repr(data))

The next two examples are identical to the above two, but support both
IPv4 and IPv6.  The server side will listen to the first address family
available (it should listen to both instead).  On most of IPv6-ready
systems, IPv6 will take precedence and the server may not accept IPv4
traffic.  The client side will try to connect to all the addresses
returned as a result of the name resolution, and sends traffic to the
first one connected successfully.

     # Echo server program
     import socket
     import sys

     HOST = None               # Symbolic name meaning all available interfaces
     PORT = 50007              # Arbitrary non-privileged port
     s = None
     for res in socket.getaddrinfo(HOST, PORT, socket.AF_UNSPEC,
                                   socket.SOCK_STREAM, 0, socket.AI_PASSIVE):
         af, socktype, proto, canonname, sa = res
         try:
             s = socket.socket(af, socktype, proto)
         except OSError as msg:
             s = None
             continue
         try:
             s.bind(sa)
             s.listen(1)
         except OSError as msg:
             s.close()
             s = None
             continue
         break
     if s is None:
         print('could not open socket')
         sys.exit(1)
     conn, addr = s.accept()
     with conn:
         print('Connected by', addr)
         while True:
             data = conn.recv(1024)
             if not data: break
             conn.send(data)

     # Echo client program
     import socket
     import sys

     HOST = 'daring.cwi.nl'    # The remote host
     PORT = 50007              # The same port as used by the server
     s = None
     for res in socket.getaddrinfo(HOST, PORT, socket.AF_UNSPEC, socket.SOCK_STREAM):
         af, socktype, proto, canonname, sa = res
         try:
             s = socket.socket(af, socktype, proto)
         except OSError as msg:
             s = None
             continue
         try:
             s.connect(sa)
         except OSError as msg:
             s.close()
             s = None
             continue
         break
     if s is None:
         print('could not open socket')
         sys.exit(1)
     with s:
         s.sendall(b'Hello, world')
         data = s.recv(1024)
     print('Received', repr(data))

The next example shows how to write a very simple network sniffer with
raw sockets on Windows.  The example requires administrator privileges
to modify the interface:

     import socket

     # the public network interface
     HOST = socket.gethostbyname(socket.gethostname())

     # create a raw socket and bind it to the public interface
     s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_IP)
     s.bind((HOST, 0))

     # Include IP headers
     s.setsockopt(socket.IPPROTO_IP, socket.IP_HDRINCL, 1)

     # receive all packets
     s.ioctl(socket.SIO_RCVALL, socket.RCVALL_ON)

     # receive a packet
     print(s.recvfrom(65565))

     # disabled promiscuous mode
     s.ioctl(socket.SIO_RCVALL, socket.RCVALL_OFF)

The next example shows how to use the socket interface to communicate to
a CAN network using the raw socket protocol.  To use CAN with the
broadcast manager protocol instead, open a socket with:

     socket.socket(socket.AF_CAN, socket.SOCK_DGRAM, socket.CAN_BCM)

After binding (‘CAN_RAW’) or connecting (*note CAN_BCM: 11a5.) the
socket, you can use the *note socket.send(): fa9. and *note
socket.recv(): fa6. operations (and their counterparts) on the socket
object as usual.

This last example might require special privileges:

     import socket
     import struct


     # CAN frame packing/unpacking (see 'struct can_frame' in <linux/can.h>)

     can_frame_fmt = "=IB3x8s"
     can_frame_size = struct.calcsize(can_frame_fmt)

     def build_can_frame(can_id, data):
         can_dlc = len(data)
         data = data.ljust(8, b'\x00')
         return struct.pack(can_frame_fmt, can_id, can_dlc, data)

     def dissect_can_frame(frame):
         can_id, can_dlc, data = struct.unpack(can_frame_fmt, frame)
         return (can_id, can_dlc, data[:can_dlc])


     # create a raw socket and bind it to the 'vcan0' interface
     s = socket.socket(socket.AF_CAN, socket.SOCK_RAW, socket.CAN_RAW)
     s.bind(('vcan0',))

     while True:
         cf, addr = s.recvfrom(can_frame_size)

         print('Received: can_id=%x, can_dlc=%x, data=%s' % dissect_can_frame(cf))

         try:
             s.send(cf)
         except OSError:
             print('Error sending CAN frame')

         try:
             s.send(build_can_frame(0x01, b'\x01\x02\x03'))
         except OSError:
             print('Error sending CAN frame')

Running an example several times with too small delay between
executions, could lead to this error:

     OSError: [Errno 98] Address already in use

This is because the previous execution has left the socket in a
‘TIME_WAIT’ state, and can’t be immediately reused.

There is a *note socket: d1. flag to set, in order to prevent this,
‘socket.SO_REUSEADDR’:

     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
     s.bind((HOST, PORT))

the ‘SO_REUSEADDR’ flag tells the kernel to reuse a local socket in
‘TIME_WAIT’ state, without waiting for its natural timeout to expire.

Vedi anche
..........

For an introduction to socket programming (in C), see the following
papers:

   - 'An Introductory 4.3BSD Interprocess Communication Tutorial', by
     Stuart Sechrest

   - 'An Advanced 4.3BSD Interprocess Communication Tutorial', by Samuel
     J. Leffler et al,

both in the UNIX Programmer’s Manual, Supplementary Documents 1
(sections PS1:7 and PS1:8).  The platform-specific reference material
for the various socket-related system calls are also a valuable source
of information on the details of socket semantics.  For Unix, refer to
the manual pages; for Windows, see the WinSock (or Winsock 2)
specification.  For IPv6-ready APIs, readers may want to refer to RFC
3493(1) titled Basic Socket Interface Extensions for IPv6.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc3493.html


File: python.info,  Node: ssl — TLS/SSL wrapper for socket objects,  Next: select — Waiting for I/O completion,  Prev: socket — Low-level networking interface,  Up: Networking and Interprocess Communication

5.19.3 ‘ssl’ — TLS/SSL wrapper for socket objects
-------------------------------------------------

'Source code:' Lib/ssl.py(1)

__________________________________________________________________

This module provides access to Transport Layer Security (often known as
«Secure Sockets Layer») encryption and peer authentication facilities
for network sockets, both client-side and server-side.  This module uses
the OpenSSL library.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

     Nota: Some behavior may be platform dependent, since calls are made
     to the operating system socket APIs.  The installed version of
     OpenSSL may also cause variations in behavior.  For example,
     TLSv1.3 comes with OpenSSL version 1.1.1.

     Avvertimento: Don’t use this module without reading the *note
     Security considerations: 387b.  Doing so may lead to a false sense
     of security, as the default settings of the ssl module are not
     necessarily appropriate for your application.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

This section documents the objects and functions in the ‘ssl’ module;
for more general information about TLS, SSL, and certificates, the
reader is referred to the documents in the «See Also» section at the
bottom.

This module provides a class, *note ssl.SSLSocket: ae9, which is derived
from the *note socket.socket: fa3. type, and provides a socket-like
wrapper that also encrypts and decrypts the data going over the socket
with SSL. It supports additional methods such as ‘getpeercert()’, which
retrieves the certificate of the other side of the connection,
‘cipher()’, which retrieves the cipher being used for the secure
connection or ‘get_verified_chain()’, ‘get_unverified_chain()’ which
retrieves certificate chain.

For more sophisticated applications, the *note ssl.SSLContext: 357.
class helps manage settings and certificates, which can then be
inherited by SSL sockets created through the *note
SSLContext.wrap_socket(): 749. method.

Cambiato nella versione 3.5.3: Updated to support linking with OpenSSL
1.1.0

Cambiato nella versione 3.6: OpenSSL 0.9.8, 1.0.0 and 1.0.1 are
deprecated and no longer supported.  In the future the ssl module will
require at least OpenSSL 1.0.2 or 1.1.0.

Cambiato nella versione 3.10: PEP 644(2) has been implemented.  The ssl
module requires OpenSSL 1.1.1 or newer.

Use of deprecated constants and functions result in deprecation
warnings.

* Menu:

* Functions, Constants, and Exceptions: Functions Constants and Exceptions.
* SSL Sockets::
* SSL Contexts::
* Certificates::
* Examples: Examples<21>.
* Notes on non-blocking sockets::
* Memory BIO Support: Memory BIO Support<2>.
* SSL session::
* Security considerations: Security considerations<2>.
* TLS 1.3: TLS 1 3.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/ssl.py

   (2) https://peps.python.org/pep-0644/


File: python.info,  Node: Functions Constants and Exceptions,  Next: SSL Sockets,  Up: ssl — TLS/SSL wrapper for socket objects

5.19.3.1 Functions, Constants, and Exceptions
.............................................

* Menu:

* Socket creation::
* Context creation::
* Exceptions: Exceptions<18>.
* Random generation::
* Certificate handling::
* Constants: Constants<9>.


File: python.info,  Node: Socket creation,  Next: Context creation,  Up: Functions Constants and Exceptions

5.19.3.2 Socket creation
........................

Instances of *note SSLSocket: ae9. must be created using the *note
SSLContext.wrap_socket(): 749. method.  The helper function *note
create_default_context(): 480. returns a new context with secure default
settings.

Client socket example with default context and IPv4/IPv6 dual stack:

     import socket
     import ssl

     hostname = 'www.python.org'
     context = ssl.create_default_context()

     with socket.create_connection((hostname, 443)) as sock:
         with context.wrap_socket(sock, server_hostname=hostname) as ssock:
             print(ssock.version())

Client socket example with custom context and IPv4:

     hostname = 'www.python.org'
     # PROTOCOL_TLS_CLIENT requires valid cert chain and hostname
     context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
     context.load_verify_locations('path/to/cabundle.pem')

     with socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0) as sock:
         with context.wrap_socket(sock, server_hostname=hostname) as ssock:
             print(ssock.version())

Server socket example listening on localhost IPv4:

     context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
     context.load_cert_chain('/path/to/certchain.pem', '/path/to/private.key')

     with socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0) as sock:
         sock.bind(('127.0.0.1', 8443))
         sock.listen(5)
         with context.wrap_socket(sock, server_side=True) as ssock:
             conn, addr = ssock.accept()
             ...


File: python.info,  Node: Context creation,  Next: Exceptions<18>,  Prev: Socket creation,  Up: Functions Constants and Exceptions

5.19.3.3 Context creation
.........................

A convenience function helps create *note SSLContext: 357. objects for
common purposes.

 -- Funzione: ssl.create_default_context (purpose=Purpose.SERVER_AUTH,
          *, cafile=None, capath=None, cadata=None)

     Return a new *note SSLContext: 357. object with default settings
     for the given 'purpose'.  The settings are chosen by the *note ssl:
     d5. module, and usually represent a higher security level than when
     calling the *note SSLContext: 357. constructor directly.

     'cafile', 'capath', 'cadata' represent optional CA certificates to
     trust for certificate verification, as in *note
     SSLContext.load_verify_locations(): 10f0.  If all three are *note
     None: 886, this function can choose to trust the system’s default
     CA certificates instead.

     The settings are: *note PROTOCOL_TLS_CLIENT: a74. or *note
     PROTOCOL_TLS_SERVER: a75, *note OP_NO_SSLv2: a3c, and *note
     OP_NO_SSLv3: a3d. with high encryption cipher suites without RC4
     and without unauthenticated cipher suites.  Passing *note
     SERVER_AUTH: 11b5. as 'purpose' sets *note verify_mode: 3996. to
     *note CERT_REQUIRED: 3997. and either loads CA certificates (when
     at least one of 'cafile', 'capath' or 'cadata' is given) or uses
     *note SSLContext.load_default_certs(): 11b4. to load default CA
     certificates.

     When *note keylog_filename: 3998. is supported and the environment
     variable ‘SSLKEYLOGFILE’ is set, *note create_default_context():
     480. enables key logging.

     The default settings for this context include *note
     VERIFY_X509_PARTIAL_CHAIN: 481. and *note VERIFY_X509_STRICT: 482.
     These make the underlying OpenSSL implementation behave more like a
     conforming implementation of RFC 5280(1), in exchange for a small
     amount of incompatibility with older X.509 certificates.

          Nota: The protocol, options, cipher and other settings may
          change to more restrictive values anytime without prior
          deprecation.  The values represent a fair balance between
          compatibility and security.

          If your application needs specific settings, you should create
          a *note SSLContext: 357. and apply the settings yourself.

          Nota: If you find that when certain older clients or servers
          attempt to connect with a *note SSLContext: 357. created by
          this function that they get an error stating «Protocol or
          cipher suite mismatch», it may be that they only support
          SSL3.0 which this function excludes using the *note
          OP_NO_SSLv3: a3d.  SSL3.0 is widely considered to be
          completely broken(2).  If you still wish to continue to use
          this function but still allow SSL 3.0 connections you can
          re-enable them using:

               ctx = ssl.create_default_context(Purpose.CLIENT_AUTH)
               ctx.options &= ~ssl.OP_NO_SSLv3

          Nota: This context enables *note VERIFY_X509_STRICT: 482. by
          default, which may reject pre- RFC 5280(3) or malformed
          certificates that the underlying OpenSSL implementation
          otherwise would accept.  While disabling this is not
          recommended, you can do so using:

               ctx = ssl.create_default_context()
               ctx.verify_flags &= ~ssl.VERIFY_X509_STRICT

     Added in version 3.4.

     Cambiato nella versione 3.4.4: RC4 was dropped from the default
     cipher string.

     Cambiato nella versione 3.6: ChaCha20/Poly1305 was added to the
     default cipher string.

     3DES was dropped from the default cipher string.

     Cambiato nella versione 3.8: Support for key logging to
     ‘SSLKEYLOGFILE’ was added.

     Cambiato nella versione 3.10: The context now uses *note
     PROTOCOL_TLS_CLIENT: a74. or *note PROTOCOL_TLS_SERVER: a75.
     protocol instead of generic *note PROTOCOL_TLS: 3999.

     Cambiato nella versione 3.13: The context now uses *note
     VERIFY_X509_PARTIAL_CHAIN: 481. and *note VERIFY_X509_STRICT: 482.
     in its default verify flags.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc5280.html

   (2) https://en.wikipedia.org/wiki/POODLE

   (3) https://datatracker.ietf.org/doc/html/rfc5280.html


File: python.info,  Node: Exceptions<18>,  Next: Random generation,  Prev: Context creation,  Up: Functions Constants and Exceptions

5.19.3.4 Exceptions
...................

 -- Eccezione: ssl.SSLError

     Raised to signal an error from the underlying SSL implementation
     (currently provided by the OpenSSL library).  This signifies some
     problem in the higher-level encryption and authentication layer
     that’s superimposed on the underlying network connection.  This
     error is a subtype of *note OSError: 2c0.  The error code and
     message of *note SSLError: 1481. instances are provided by the
     OpenSSL library.

     Cambiato nella versione 3.3: *note SSLError: 1481. used to be a
     subtype of *note socket.error: 1258.

      -- Attributo: library

          A string mnemonic designating the OpenSSL submodule in which
          the error occurred, such as ‘SSL’, ‘PEM’ or ‘X509’.  The range
          of possible values depends on the OpenSSL version.

          Added in version 3.3.

      -- Attributo: reason

          A string mnemonic designating the reason this error occurred,
          for example ‘CERTIFICATE_VERIFY_FAILED’.  The range of
          possible values depends on the OpenSSL version.

          Added in version 3.3.

 -- Eccezione: ssl.SSLZeroReturnError

     A subclass of *note SSLError: 1481. raised when trying to read or
     write and the SSL connection has been closed cleanly.  Note that
     this doesn’t mean that the underlying transport (read TCP) has been
     closed.

     Added in version 3.3.

 -- Eccezione: ssl.SSLWantReadError

     A subclass of *note SSLError: 1481. raised by a *note non-blocking
     SSL socket: 399c. when trying to read or write data, but more data
     needs to be received on the underlying TCP transport before the
     request can be fulfilled.

     Added in version 3.3.

 -- Eccezione: ssl.SSLWantWriteError

     A subclass of *note SSLError: 1481. raised by a *note non-blocking
     SSL socket: 399c. when trying to read or write data, but more data
     needs to be sent on the underlying TCP transport before the request
     can be fulfilled.

     Added in version 3.3.

 -- Eccezione: ssl.SSLSyscallError

     A subclass of *note SSLError: 1481. raised when a system error was
     encountered while trying to fulfill an operation on a SSL socket.
     Unfortunately, there is no easy way to inspect the original errno
     number.

     Added in version 3.3.

 -- Eccezione: ssl.SSLEOFError

     A subclass of *note SSLError: 1481. raised when the SSL connection
     has been terminated abruptly.  Generally, you shouldn’t try to
     reuse the underlying transport when this error is encountered.

     Added in version 3.3.

 -- Eccezione: ssl.SSLCertVerificationError

     A subclass of *note SSLError: 1481. raised when certificate
     validation has failed.

     Added in version 3.7.

      -- Attributo: verify_code

          A numeric error number that denotes the verification error.

      -- Attributo: verify_message

          A human readable string of the verification error.

 -- Eccezione: ssl.CertificateError

     An alias for *note SSLCertVerificationError: d77.

     Cambiato nella versione 3.7: The exception is now an alias for
     *note SSLCertVerificationError: d77.


File: python.info,  Node: Random generation,  Next: Certificate handling,  Prev: Exceptions<18>,  Up: Functions Constants and Exceptions

5.19.3.5 Random generation
..........................

 -- Funzione: ssl.RAND_bytes (num, /)

     Return 'num' cryptographically strong pseudo-random bytes.  Raises
     an *note SSLError: 1481. if the PRNG has not been seeded with
     enough data or if the operation is not supported by the current
     RAND method.  *note RAND_status(): 1c66. can be used to check the
     status of the PRNG and *note RAND_add(): 39a2. can be used to seed
     the PRNG.

     For almost all applications *note os.urandom(): 747. is preferable.

     Read the Wikipedia article, Cryptographically secure pseudorandom
     number generator (CSPRNG)(1), to get the requirements of a
     cryptographically strong generator.

     Added in version 3.3.

 -- Funzione: ssl.RAND_status ()

     Return ‘True’ if the SSL pseudo-random number generator has been
     seeded with “enough” randomness, and ‘False’ otherwise.  You can
     use ‘ssl.RAND_egd()’ and *note ssl.RAND_add(): 39a2. to increase
     the randomness of the pseudo-random number generator.

 -- Funzione: ssl.RAND_add (bytes, entropy, /)

     Mix the given 'bytes' into the SSL pseudo-random number generator.
     The parameter 'entropy' (a float) is a lower bound on the entropy
     contained in string (so you can always use ‘0.0’).  See RFC 1750(2)
     for more information on sources of entropy.

     Cambiato nella versione 3.5: Writable *note bytes-like object: 193.
     is now accepted.

   ---------- Footnotes ----------

   (1) 
https://en.wikipedia.org/wiki/Cryptographically_secure_pseudorandom_number_generator

   (2) https://datatracker.ietf.org/doc/html/rfc1750.html


File: python.info,  Node: Certificate handling,  Next: Constants<9>,  Prev: Random generation,  Up: Functions Constants and Exceptions

5.19.3.6 Certificate handling
.............................

 -- Funzione: ssl.cert_time_to_seconds (cert_time)

     Return the time in seconds since the Epoch, given the ‘cert_time’
     string representing the «notBefore» or «notAfter» date from a
     certificate in ‘"%b %d %H:%M:%S %Y %Z"’ strptime format (C locale).

     Here’s an example:

          >>> import ssl
          >>> timestamp = ssl.cert_time_to_seconds("Jan  5 09:34:43 2018 GMT")
          >>> timestamp
          1515144883
          >>> from datetime import datetime
          >>> print(datetime.utcfromtimestamp(timestamp))
          2018-01-05 09:34:43

     «notBefore» or «notAfter» dates must use GMT ( RFC 5280(1)).

     Cambiato nella versione 3.5: Interpret the input time as a time in
     UTC as specified by “GMT” timezone in the input string.  Local
     timezone was used previously.  Return an integer (no fractions of a
     second in the input format)

 -- Funzione: ssl.get_server_certificate (addr,
          ssl_version=PROTOCOL_TLS_CLIENT, ca_certs=None[, timeout])

     Given the address ‘addr’ of an SSL-protected server, as a
     ('hostname', 'port-number') pair, fetches the server’s certificate,
     and returns it as a PEM-encoded string.  If ‘ssl_version’ is
     specified, uses that version of the SSL protocol to attempt to
     connect to the server.  If 'ca_certs' is specified, it should be a
     file containing a list of root certificates, the same format as
     used for the 'cafile' parameter in *note
     SSLContext.load_verify_locations(): 10f0.  The call will attempt to
     validate the server certificate against that set of root
     certificates, and will fail if the validation attempt fails.  A
     timeout can be specified with the ‘timeout’ parameter.

     Cambiato nella versione 3.3: This function is now IPv6-compatible.

     Cambiato nella versione 3.5: The default 'ssl_version' is changed
     from *note PROTOCOL_SSLv3: 39a4. to *note PROTOCOL_TLS: 3999. for
     maximum compatibility with modern servers.

     Cambiato nella versione 3.10: The 'timeout' parameter was added.

 -- Funzione: ssl.DER_cert_to_PEM_cert (der_cert_bytes)

     Given a certificate as a DER-encoded blob of bytes, returns a
     PEM-encoded string version of the same certificate.

 -- Funzione: ssl.PEM_cert_to_DER_cert (pem_cert_string)

     Given a certificate as an ASCII PEM string, returns a DER-encoded
     sequence of bytes for that same certificate.

 -- Funzione: ssl.get_default_verify_paths ()

     Returns a named tuple with paths to OpenSSL’s default cafile and
     capath.  The paths are the same as used by *note
     SSLContext.set_default_verify_paths(): 11ad.  The return value is a
     *note named tuple: 85f. ‘DefaultVerifyPaths’:

        * ‘cafile’ - resolved path to cafile or ‘None’ if the file
          doesn’t exist,

        * ‘capath’ - resolved path to capath or ‘None’ if the directory
          doesn’t exist,

        * ‘openssl_cafile_env’ - OpenSSL’s environment key that points
          to a cafile,

        * ‘openssl_cafile’ - hard coded path to a cafile,

        * ‘openssl_capath_env’ - OpenSSL’s environment key that points
          to a capath,

        * ‘openssl_capath’ - hard coded path to a capath directory

     Added in version 3.4.

 -- Funzione: ssl.enum_certificates (store_name)

     Retrieve certificates from Windows” system cert store.
     'store_name' may be one of ‘CA’, ‘ROOT’ or ‘MY’.  Windows may
     provide additional cert stores, too.

     The function returns a list of (cert_bytes, encoding_type, trust)
     tuples.  The encoding_type specifies the encoding of cert_bytes.
     It is either ‘x509_asn’ for X.509 ASN.1 data or ‘pkcs_7_asn’ for
     PKCS#7 ASN.1 data.  Trust specifies the purpose of the certificate
     as a set of OIDS or exactly ‘True’ if the certificate is
     trustworthy for all purposes.

     Example:

          >>> ssl.enum_certificates("CA")
          [(b'data...', 'x509_asn', {'1.3.6.1.5.5.7.3.1', '1.3.6.1.5.5.7.3.2'}),
           (b'data...', 'x509_asn', True)]

     *note Availability: 2128.: Windows.

     Added in version 3.4.

 -- Funzione: ssl.enum_crls (store_name)

     Retrieve CRLs from Windows” system cert store.  'store_name' may be
     one of ‘CA’, ‘ROOT’ or ‘MY’.  Windows may provide additional cert
     stores, too.

     The function returns a list of (cert_bytes, encoding_type, trust)
     tuples.  The encoding_type specifies the encoding of cert_bytes.
     It is either ‘x509_asn’ for X.509 ASN.1 data or ‘pkcs_7_asn’ for
     PKCS#7 ASN.1 data.

     *note Availability: 2128.: Windows.

     Added in version 3.4.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc5280.html


File: python.info,  Node: Constants<9>,  Prev: Certificate handling,  Up: Functions Constants and Exceptions

5.19.3.7 Constants
..................

     All constants are now *note enum.IntEnum: edd. or *note
     enum.IntFlag: e9c. collections.

     Added in version 3.6.

 -- Dati: ssl.CERT_NONE

     Possible value for *note SSLContext.verify_mode: 3996.  Except for
     *note PROTOCOL_TLS_CLIENT: a74, it is the default mode.  With
     client-side sockets, just about any cert is accepted.  Validation
     errors, such as untrusted or expired cert, are ignored and do not
     abort the TLS/SSL handshake.

     In server mode, no certificate is requested from the client, so the
     client does not send any for client cert authentication.

     See the discussion of *note Security considerations: 387b. below.

 -- Dati: ssl.CERT_OPTIONAL

     Possible value for *note SSLContext.verify_mode: 3996.  In client
     mode, *note CERT_OPTIONAL: 39a9. has the same meaning as *note
     CERT_REQUIRED: 3997.  It is recommended to use *note CERT_REQUIRED:
     3997. for client-side sockets instead.

     In server mode, a client certificate request is sent to the client.
     The client may either ignore the request or send a certificate in
     order perform TLS client cert authentication.  If the client
     chooses to send a certificate, it is verified.  Any verification
     error immediately aborts the TLS handshake.

     Use of this setting requires a valid set of CA certificates to be
     passed to *note SSLContext.load_verify_locations(): 10f0.

 -- Dati: ssl.CERT_REQUIRED

     Possible value for *note SSLContext.verify_mode: 3996.  In this
     mode, certificates are required from the other side of the socket
     connection; an *note SSLError: 1481. will be raised if no
     certificate is provided, or if its validation fails.  This mode is
     'not' sufficient to verify a certificate in client mode as it does
     not match hostnames.  *note check_hostname: 39aa. must be enabled
     as well to verify the authenticity of a cert.  *note
     PROTOCOL_TLS_CLIENT: a74. uses *note CERT_REQUIRED: 3997. and
     enables *note check_hostname: 39aa. by default.

     With server socket, this mode provides mandatory TLS client cert
     authentication.  A client certificate request is sent to the client
     and the client must provide a valid and trusted certificate.

     Use of this setting requires a valid set of CA certificates to be
     passed to *note SSLContext.load_verify_locations(): 10f0.

 -- Classe: ssl.VerifyMode

     *note enum.IntEnum: edd. collection of CERT_* constants.

     Added in version 3.6.

 -- Dati: ssl.VERIFY_DEFAULT

     Possible value for *note SSLContext.verify_flags: 11b0.  In this
     mode, certificate revocation lists (CRLs) are not checked.  By
     default OpenSSL does neither require nor verify CRLs.

     Added in version 3.4.

 -- Dati: ssl.VERIFY_CRL_CHECK_LEAF

     Possible value for *note SSLContext.verify_flags: 11b0.  In this
     mode, only the peer cert is checked but none of the intermediate CA
     certificates.  The mode requires a valid CRL that is signed by the
     peer cert’s issuer (its direct ancestor CA). If no proper CRL has
     been loaded with *note SSLContext.load_verify_locations: 10f0,
     validation will fail.

     Added in version 3.4.

 -- Dati: ssl.VERIFY_CRL_CHECK_CHAIN

     Possible value for *note SSLContext.verify_flags: 11b0.  In this
     mode, CRLs of all certificates in the peer cert chain are checked.

     Added in version 3.4.

 -- Dati: ssl.VERIFY_X509_STRICT

     Possible value for *note SSLContext.verify_flags: 11b0. to disable
     workarounds for broken X.509 certificates.

     Added in version 3.4.

 -- Dati: ssl.VERIFY_ALLOW_PROXY_CERTS

     Possible value for *note SSLContext.verify_flags: 11b0. to enables
     proxy certificate verification.

     Added in version 3.10.

 -- Dati: ssl.VERIFY_X509_TRUSTED_FIRST

     Possible value for *note SSLContext.verify_flags: 11b0.  It
     instructs OpenSSL to prefer trusted certificates when building the
     trust chain to validate a certificate.  This flag is enabled by
     default.

     Added in version 3.4.4.

 -- Dati: ssl.VERIFY_X509_PARTIAL_CHAIN

     Possible value for *note SSLContext.verify_flags: 11b0.  It
     instructs OpenSSL to accept intermediate CAs in the trust store to
     be treated as trust-anchors, in the same way as the self-signed
     root CA certificates.  This makes it possible to trust certificates
     issued by an intermediate CA without having to trust its ancestor
     root CA.

     Added in version 3.10.

 -- Classe: ssl.VerifyFlags

     *note enum.IntFlag: e9c. collection of VERIFY_* constants.

     Added in version 3.6.

 -- Dati: ssl.PROTOCOL_TLS

     Selects the highest protocol version that both the client and
     server support.  Despite the name, this option can select both
     «SSL» and «TLS» protocols.

     Added in version 3.6.

     Deprecato dalla versione 3.10: TLS clients and servers require
     different default settings for secure communication.  The generic
     TLS protocol constant is deprecated in favor of *note
     PROTOCOL_TLS_CLIENT: a74. and *note PROTOCOL_TLS_SERVER: a75.

 -- Dati: ssl.PROTOCOL_TLS_CLIENT

     Auto-negotiate the highest protocol version that both the client
     and server support, and configure the context client-side
     connections.  The protocol enables *note CERT_REQUIRED: 3997. and
     *note check_hostname: 39aa. by default.

     Added in version 3.6.

 -- Dati: ssl.PROTOCOL_TLS_SERVER

     Auto-negotiate the highest protocol version that both the client
     and server support, and configure the context server-side
     connections.

     Added in version 3.6.

 -- Dati: ssl.PROTOCOL_SSLv23

     Alias for *note PROTOCOL_TLS: 3999.

     Deprecato dalla versione 3.6: Use *note PROTOCOL_TLS: 3999.
     instead.

 -- Dati: ssl.PROTOCOL_SSLv3

     Selects SSL version 3 as the channel encryption protocol.

     This protocol is not available if OpenSSL is compiled with the
     ‘no-ssl3’ option.

          Avvertimento: SSL version 3 is insecure.  Its use is highly
          discouraged.

     Deprecato dalla versione 3.6: OpenSSL has deprecated all version
     specific protocols.  Use the default protocol *note
     PROTOCOL_TLS_SERVER: a75. or *note PROTOCOL_TLS_CLIENT: a74. with
     *note SSLContext.minimum_version: a72. and *note
     SSLContext.maximum_version: a73. instead.

 -- Dati: ssl.PROTOCOL_TLSv1

     Selects TLS version 1.0 as the channel encryption protocol.

     Deprecato dalla versione 3.6: OpenSSL has deprecated all version
     specific protocols.

 -- Dati: ssl.PROTOCOL_TLSv1_1

     Selects TLS version 1.1 as the channel encryption protocol.
     Available only with openssl version 1.0.1+.

     Added in version 3.4.

     Deprecato dalla versione 3.6: OpenSSL has deprecated all version
     specific protocols.

 -- Dati: ssl.PROTOCOL_TLSv1_2

     Selects TLS version 1.2 as the channel encryption protocol.
     Available only with openssl version 1.0.1+.

     Added in version 3.4.

     Deprecato dalla versione 3.6: OpenSSL has deprecated all version
     specific protocols.

 -- Dati: ssl.OP_ALL

     Enables workarounds for various bugs present in other SSL
     implementations.  This option is set by default.  It does not
     necessarily set the same flags as OpenSSL’s ‘SSL_OP_ALL’ constant.

     Added in version 3.2.

 -- Dati: ssl.OP_NO_SSLv2

     Prevents an SSLv2 connection.  This option is only applicable in
     conjunction with *note PROTOCOL_TLS: 3999.  It prevents the peers
     from choosing SSLv2 as the protocol version.

     Added in version 3.2.

     Deprecato dalla versione 3.6: SSLv2 is deprecated

 -- Dati: ssl.OP_NO_SSLv3

     Prevents an SSLv3 connection.  This option is only applicable in
     conjunction with *note PROTOCOL_TLS: 3999.  It prevents the peers
     from choosing SSLv3 as the protocol version.

     Added in version 3.2.

     Deprecato dalla versione 3.6: SSLv3 is deprecated

 -- Dati: ssl.OP_NO_TLSv1

     Prevents a TLSv1 connection.  This option is only applicable in
     conjunction with *note PROTOCOL_TLS: 3999.  It prevents the peers
     from choosing TLSv1 as the protocol version.

     Added in version 3.2.

     Deprecato dalla versione 3.7: The option is deprecated since
     OpenSSL 1.1.0, use the new *note SSLContext.minimum_version: a72.
     and *note SSLContext.maximum_version: a73. instead.

 -- Dati: ssl.OP_NO_TLSv1_1

     Prevents a TLSv1.1 connection.  This option is only applicable in
     conjunction with *note PROTOCOL_TLS: 3999.  It prevents the peers
     from choosing TLSv1.1 as the protocol version.  Available only with
     openssl version 1.0.1+.

     Added in version 3.4.

     Deprecato dalla versione 3.7: The option is deprecated since
     OpenSSL 1.1.0.

 -- Dati: ssl.OP_NO_TLSv1_2

     Prevents a TLSv1.2 connection.  This option is only applicable in
     conjunction with *note PROTOCOL_TLS: 3999.  It prevents the peers
     from choosing TLSv1.2 as the protocol version.  Available only with
     openssl version 1.0.1+.

     Added in version 3.4.

     Deprecato dalla versione 3.7: The option is deprecated since
     OpenSSL 1.1.0.

 -- Dati: ssl.OP_NO_TLSv1_3

     Prevents a TLSv1.3 connection.  This option is only applicable in
     conjunction with *note PROTOCOL_TLS: 3999.  It prevents the peers
     from choosing TLSv1.3 as the protocol version.  TLS 1.3 is
     available with OpenSSL 1.1.1 or later.  When Python has been
     compiled against an older version of OpenSSL, the flag defaults to
     '0'.

     Added in version 3.6.3.

     Deprecato dalla versione 3.7: The option is deprecated since
     OpenSSL 1.1.0.  It was added to 2.7.15 and 3.6.3 for backwards
     compatibility with OpenSSL 1.0.2.

 -- Dati: ssl.OP_NO_RENEGOTIATION

     Disable all renegotiation in TLSv1.2 and earlier.  Do not send
     HelloRequest messages, and ignore renegotiation requests via
     ClientHello.

     This option is only available with OpenSSL 1.1.0h and later.

     Added in version 3.7.

 -- Dati: ssl.OP_CIPHER_SERVER_PREFERENCE

     Use the server’s cipher ordering preference, rather than the
     client’s.  This option has no effect on client sockets and SSLv2
     server sockets.

     Added in version 3.3.

 -- Dati: ssl.OP_SINGLE_DH_USE

     Prevents reuse of the same DH key for distinct SSL sessions.  This
     improves forward secrecy but requires more computational resources.
     This option only applies to server sockets.

     Added in version 3.3.

 -- Dati: ssl.OP_SINGLE_ECDH_USE

     Prevents reuse of the same ECDH key for distinct SSL sessions.
     This improves forward secrecy but requires more computational
     resources.  This option only applies to server sockets.

     Added in version 3.3.

 -- Dati: ssl.OP_ENABLE_MIDDLEBOX_COMPAT

     Send dummy Change Cipher Spec (CCS) messages in TLS 1.3 handshake
     to make a TLS 1.3 connection look more like a TLS 1.2 connection.

     This option is only available with OpenSSL 1.1.1 and later.

     Added in version 3.8.

 -- Dati: ssl.OP_NO_COMPRESSION

     Disable compression on the SSL channel.  This is useful if the
     application protocol supports its own compression scheme.

     Added in version 3.3.

 -- Classe: ssl.Options

     *note enum.IntFlag: e9c. collection of OP_* constants.

 -- Dati: ssl.OP_NO_TICKET

     Prevent client side from requesting a session ticket.

     Added in version 3.6.

 -- Dati: ssl.OP_IGNORE_UNEXPECTED_EOF

     Ignore unexpected shutdown of TLS connections.

     This option is only available with OpenSSL 3.0.0 and later.

     Added in version 3.10.

 -- Dati: ssl.OP_ENABLE_KTLS

     Enable the use of the kernel TLS. To benefit from the feature,
     OpenSSL must have been compiled with support for it, and the
     negotiated cipher suites and extensions must be supported by it (a
     list of supported ones may vary by platform and kernel version).

     Note that with enabled kernel TLS some cryptographic operations are
     performed by the kernel directly and not via any available OpenSSL
     Providers.  This might be undesirable if, for example, the
     application requires all cryptographic operations to be performed
     by the FIPS provider.

     This option is only available with OpenSSL 3.0.0 and later.

     Added in version 3.12.

 -- Dati: ssl.OP_LEGACY_SERVER_CONNECT

     Allow legacy insecure renegotiation between OpenSSL and unpatched
     servers only.

     Added in version 3.12.

 -- Dati: ssl.HAS_ALPN

     Whether the OpenSSL library has built-in support for the
     'Application-Layer Protocol Negotiation' TLS extension as described
     in RFC 7301(1).

     Added in version 3.5.

 -- Dati: ssl.HAS_NEVER_CHECK_COMMON_NAME

     Whether the OpenSSL library has built-in support not checking
     subject common name and *note
     SSLContext.hostname_checks_common_name: d78. is writeable.

     Added in version 3.7.

 -- Dati: ssl.HAS_ECDH

     Whether the OpenSSL library has built-in support for the Elliptic
     Curve-based Diffie-Hellman key exchange.  This should be true
     unless the feature was explicitly disabled by the distributor.

     Added in version 3.3.

 -- Dati: ssl.HAS_SNI

     Whether the OpenSSL library has built-in support for the 'Server
     Name Indication' extension (as defined in RFC 6066(2)).

     Added in version 3.2.

 -- Dati: ssl.HAS_NPN

     Whether the OpenSSL library has built-in support for the 'Next
     Protocol Negotiation' as described in the Application Layer
     Protocol Negotiation(3).  When true, you can use the *note
     SSLContext.set_npn_protocols(): 358. method to advertise which
     protocols you want to support.

     Added in version 3.3.

 -- Dati: ssl.HAS_SSLv2

     Whether the OpenSSL library has built-in support for the SSL 2.0
     protocol.

     Added in version 3.7.

 -- Dati: ssl.HAS_SSLv3

     Whether the OpenSSL library has built-in support for the SSL 3.0
     protocol.

     Added in version 3.7.

 -- Dati: ssl.HAS_TLSv1

     Whether the OpenSSL library has built-in support for the TLS 1.0
     protocol.

     Added in version 3.7.

 -- Dati: ssl.HAS_TLSv1_1

     Whether the OpenSSL library has built-in support for the TLS 1.1
     protocol.

     Added in version 3.7.

 -- Dati: ssl.HAS_TLSv1_2

     Whether the OpenSSL library has built-in support for the TLS 1.2
     protocol.

     Added in version 3.7.

 -- Dati: ssl.HAS_TLSv1_3

     Whether the OpenSSL library has built-in support for the TLS 1.3
     protocol.

     Added in version 3.7.

 -- Dati: ssl.HAS_PSK

     Whether the OpenSSL library has built-in support for TLS-PSK.

     Added in version 3.13.

 -- Dati: ssl.HAS_PHA

     Whether the OpenSSL library has built-in support for TLS-PHA.

     Added in version 3.14.

 -- Dati: ssl.CHANNEL_BINDING_TYPES

     List of supported TLS channel binding types.  Strings in this list
     can be used as arguments to *note SSLSocket.get_channel_binding():
     134c.

     Added in version 3.3.

 -- Dati: ssl.OPENSSL_VERSION

     The version string of the OpenSSL library loaded by the
     interpreter:

          >>> ssl.OPENSSL_VERSION
          'OpenSSL 1.0.2k  26 Jan 2017'

     Added in version 3.2.

 -- Dati: ssl.OPENSSL_VERSION_INFO

     A tuple of five integers representing version information about the
     OpenSSL library:

          >>> ssl.OPENSSL_VERSION_INFO
          (1, 0, 2, 11, 15)

     Added in version 3.2.

 -- Dati: ssl.OPENSSL_VERSION_NUMBER

     The raw version number of the OpenSSL library, as a single integer:

          >>> ssl.OPENSSL_VERSION_NUMBER
          268443839
          >>> hex(ssl.OPENSSL_VERSION_NUMBER)
          '0x100020bf'

     Added in version 3.2.

 -- Dati: ssl.ALERT_DESCRIPTION_HANDSHAKE_FAILURE
 -- Dati: ssl.ALERT_DESCRIPTION_INTERNAL_ERROR

 -- Dati: ALERT_DESCRIPTION_*

     Alert Descriptions from RFC 5246(4) and others.  The IANA TLS Alert
     Registry(5) contains this list and references to the RFCs where
     their meaning is defined.

     Used as the return value of the callback function in *note
     SSLContext.set_servername_callback(): 11b9.

     Added in version 3.4.

 -- Classe: ssl.AlertDescription

     *note enum.IntEnum: edd. collection of ALERT_DESCRIPTION_*
     constants.

     Added in version 3.6.

 -- Dati: Purpose.SERVER_AUTH

     Option for *note create_default_context(): 480. and *note
     SSLContext.load_default_certs(): 11b4.  This value indicates that
     the context may be used to authenticate web servers (therefore, it
     will be used to create client-side sockets).

     Added in version 3.4.

 -- Dati: Purpose.CLIENT_AUTH

     Option for *note create_default_context(): 480. and *note
     SSLContext.load_default_certs(): 11b4.  This value indicates that
     the context may be used to authenticate web clients (therefore, it
     will be used to create server-side sockets).

     Added in version 3.4.

 -- Classe: ssl.SSLErrorNumber

     *note enum.IntEnum: edd. collection of SSL_ERROR_* constants.

     Added in version 3.6.

 -- Classe: ssl.TLSVersion

     *note enum.IntEnum: edd. collection of SSL and TLS versions for
     *note SSLContext.maximum_version: a73. and *note
     SSLContext.minimum_version: a72.

     Added in version 3.7.

 -- Attributo: TLSVersion.MINIMUM_SUPPORTED

 -- Attributo: TLSVersion.MAXIMUM_SUPPORTED

     The minimum or maximum supported SSL or TLS version.  These are
     magic constants.  Their values don’t reflect the lowest and highest
     available TLS/SSL versions.

 -- Attributo: TLSVersion.SSLv3

 -- Attributo: TLSVersion.TLSv1

 -- Attributo: TLSVersion.TLSv1_1

 -- Attributo: TLSVersion.TLSv1_2

 -- Attributo: TLSVersion.TLSv1_3

     SSL 3.0 to TLS 1.3.

     Deprecato dalla versione 3.10: All *note TLSVersion: 39c9. members
     except *note TLSVersion.TLSv1_2: 39cf. and *note
     TLSVersion.TLSv1_3: 39d0. are deprecated.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc7301.html

   (2) https://datatracker.ietf.org/doc/html/rfc6066.html

   (3) 
https://en.wikipedia.org/wiki/Application-Layer_Protocol_Negotiation

   (4) https://datatracker.ietf.org/doc/html/rfc5246.html

   (5) 
https://www.iana.org/assignments/tls-parameters/tls-parameters.xml#tls-parameters-6


File: python.info,  Node: SSL Sockets,  Next: SSL Contexts,  Prev: Functions Constants and Exceptions,  Up: ssl — TLS/SSL wrapper for socket objects

5.19.3.8 SSL Sockets
....................

 -- Classe: ssl.SSLSocket (socket.socket)

     SSL sockets provide the following methods of *note Socket Objects:
     3977.:

        - *note accept(): fa4.

        - *note bind(): 1741.

        - *note close(): f41.

        - *note connect(): fa5.

        - *note detach(): 1424.

        - *note fileno(): 3985.

        - *note getpeername(): 38bf, *note getsockname(): 284.

        - *note getsockopt(): ed2, *note setsockopt(): ed3.

        - *note gettimeout(): 3986, *note settimeout(): 3937, *note
          setblocking(): 3021.

        - *note listen(): 1060.

        - *note makefile(): 13a7.

        - *note recv(): fa6, *note recv_into(): 1525. (but passing a
          non-zero ‘flags’ argument is not allowed)

        - *note send(): fa9, *note sendall(): faa. (with the same
          limitation)

        - *note sendfile(): 105f. (but *note os.sendfile: d07. will be
          used for plain-text sockets only, else *note send(): fa9. will
          be used)

        - *note shutdown(): 3974.

     However, since the SSL (and TLS) protocol has its own framing atop
     of TCP, the SSL sockets abstraction can, in certain respects,
     diverge from the specification of normal, OS-level sockets.  See
     especially the *note notes on non-blocking sockets: 399c.

     Instances of *note SSLSocket: ae9. must be created using the *note
     SSLContext.wrap_socket(): 749. method.

     Cambiato nella versione 3.5: The ‘sendfile()’ method was added.

     Cambiato nella versione 3.5: The ‘shutdown()’ does not reset the
     socket timeout each time bytes are received or sent.  The socket
     timeout is now the maximum total duration of the shutdown.

     Deprecato dalla versione 3.6: It is deprecated to create a *note
     SSLSocket: ae9. instance directly, use *note
     SSLContext.wrap_socket(): 749. to wrap a socket.

     Cambiato nella versione 3.7: *note SSLSocket: ae9. instances must
     to created with *note wrap_socket(): 749.  In earlier versions, it
     was possible to create instances directly.  This was never
     documented or officially supported.

     Cambiato nella versione 3.10: Python now uses ‘SSL_read_ex’ and
     ‘SSL_write_ex’ internally.  The functions support reading and
     writing of data larger than 2 GB. Writing zero-length data no
     longer fails with a protocol violation error.

SSL sockets also have the following additional methods and attributes:

 -- Metodo: SSLSocket.read (len=1024, buffer=None)

     Read up to 'len' bytes of data from the SSL socket and return the
     result as a ‘bytes’ instance.  If 'buffer' is specified, then read
     into the buffer instead, and return the number of bytes read.

     Raise *note SSLWantReadError: 106b. or *note SSLWantWriteError:
     106c. if the socket is *note non-blocking: 399c. and the read would
     block.

     As at any time a re-negotiation is possible, a call to *note
     read(): 1070. can also cause write operations.

     Cambiato nella versione 3.5: The socket timeout is no longer reset
     each time bytes are received or sent.  The socket timeout is now
     the maximum total duration to read up to 'len' bytes.

     Deprecato dalla versione 3.6: Use ‘recv()’ instead of *note read():
     1070.

 -- Metodo: SSLSocket.write (data)

     Write 'data' to the SSL socket and return the number of bytes
     written.  The 'data' argument must be an object supporting the
     buffer interface.

     Raise *note SSLWantReadError: 106b. or *note SSLWantWriteError:
     106c. if the socket is *note non-blocking: 399c. and the write
     would block.

     As at any time a re-negotiation is possible, a call to *note
     write(): 1071. can also cause read operations.

     Cambiato nella versione 3.5: The socket timeout is no longer reset
     each time bytes are received or sent.  The socket timeout is now
     the maximum total duration to write 'data'.

     Deprecato dalla versione 3.6: Use ‘send()’ instead of *note
     write(): 1071.

     Nota: The *note read(): 1070. and *note write(): 1071. methods are
     the low-level methods that read and write unencrypted,
     application-level data and decrypt/encrypt it to encrypted,
     wire-level data.  These methods require an active SSL connection,
     i.e.  the handshake was completed and *note SSLSocket.unwrap():
     39d2. was not called.

     Normally you should use the socket API methods like *note recv():
     fa6. and *note send(): fa9. instead of these methods.

 -- Metodo: SSLSocket.do_handshake (block=False)

     Perform the SSL setup handshake.

     If 'block' is true and the timeout obtained by *note gettimeout():
     3986. is zero, the socket is set in blocking mode until the
     handshake is performed.

     Cambiato nella versione 3.4: The handshake method also performs
     ‘match_hostname()’ when the *note check_hostname: 39aa. attribute
     of the socket’s *note context: 39d3. is true.

     Cambiato nella versione 3.5: The socket timeout is no longer reset
     each time bytes are received or sent.  The socket timeout is now
     the maximum total duration of the handshake.

     Cambiato nella versione 3.7: Hostname or IP address is matched by
     OpenSSL during handshake.  The function ‘match_hostname()’ is no
     longer used.  In case OpenSSL refuses a hostname or IP address, the
     handshake is aborted early and a TLS alert message is sent to the
     peer.

 -- Metodo: SSLSocket.getpeercert (binary_form=False)

     If there is no certificate for the peer on the other end of the
     connection, return ‘None’.  If the SSL handshake hasn’t been done
     yet, raise *note ValueError: 2ec.

     If the ‘binary_form’ parameter is *note False: d2d, and a
     certificate was received from the peer, this method returns a *note
     dict: 183. instance.  If the certificate was not validated, the
     dict is empty.  If the certificate was validated, it returns a dict
     with several keys, amongst them ‘subject’ (the principal for which
     the certificate was issued) and ‘issuer’ (the principal issuing the
     certificate).  If a certificate contains an instance of the
     'Subject Alternative Name' extension (see RFC 3280(1)), there will
     also be a ‘subjectAltName’ key in the dictionary.

     The ‘subject’ and ‘issuer’ fields are tuples containing the
     sequence of relative distinguished names (RDNs) given in the
     certificate’s data structure for the respective fields, and each
     RDN is a sequence of name-value pairs.  Here is a real-world
     example:

          {'issuer': ((('countryName', 'IL'),),
                      (('organizationName', 'StartCom Ltd.'),),
                      (('organizationalUnitName',
                        'Secure Digital Certificate Signing'),),
                      (('commonName',
                        'StartCom Class 2 Primary Intermediate Server CA'),)),
           'notAfter': 'Nov 22 08:15:19 2013 GMT',
           'notBefore': 'Nov 21 03:09:52 2011 GMT',
           'serialNumber': '95F0',
           'subject': ((('description', '571208-SLe257oHY9fVQ07Z'),),
                       (('countryName', 'US'),),
                       (('stateOrProvinceName', 'California'),),
                       (('localityName', 'San Francisco'),),
                       (('organizationName', 'Electronic Frontier Foundation, Inc.'),),
                       (('commonName', '*.eff.org'),),
                       (('emailAddress', 'hostmaster@eff.org'),)),
           'subjectAltName': (('DNS', '*.eff.org'), ('DNS', 'eff.org')),
           'version': 3}

     If the ‘binary_form’ parameter is *note True: e09, and a
     certificate was provided, this method returns the DER-encoded form
     of the entire certificate as a sequence of bytes, or *note None:
     886. if the peer did not provide a certificate.  Whether the peer
     provides a certificate depends on the SSL socket’s role:

        * for a client SSL socket, the server will always provide a
          certificate, regardless of whether validation was required;

        * for a server SSL socket, the client will only provide a
          certificate when requested by the server; therefore *note
          getpeercert(): 11ba. will return *note None: 886. if you used
          *note CERT_NONE: 39a8. (rather than *note CERT_OPTIONAL: 39a9.
          or *note CERT_REQUIRED: 3997.).

     See also *note SSLContext.check_hostname: 39aa.

     Cambiato nella versione 3.2: The returned dictionary includes
     additional items such as ‘issuer’ and ‘notBefore’.

     Cambiato nella versione 3.4: *note ValueError: 2ec. is raised when
     the handshake isn’t done.  The returned dictionary includes
     additional X509v3 extension items such as ‘crlDistributionPoints’,
     ‘caIssuers’ and ‘OCSP’ URIs.

     Cambiato nella versione 3.9: IPv6 address strings no longer have a
     trailing new line.

 -- Metodo: SSLSocket.get_verified_chain ()

     Returns verified certificate chain provided by the other end of the
     SSL channel as a list of DER-encoded bytes.  If certificate
     verification was disabled method acts the same as *note
     get_unverified_chain(): 1945.

     Added in version 3.13.

 -- Metodo: SSLSocket.get_unverified_chain ()

     Returns raw certificate chain provided by the other end of the SSL
     channel as a list of DER-encoded bytes.

     Added in version 3.13.

 -- Metodo: SSLSocket.cipher ()

     Returns a three-value tuple containing the name of the cipher being
     used, the version of the SSL protocol that defines its use, and the
     number of secret bits being used.  If no connection has been
     established, returns ‘None’.

 -- Metodo: SSLSocket.shared_ciphers ()

     Return the list of ciphers available in both the client and server.
     Each entry of the returned list is a three-value tuple containing
     the name of the cipher, the version of the SSL protocol that
     defines its use, and the number of secret bits the cipher uses.
     *note shared_ciphers(): 106e. returns ‘None’ if no connection has
     been established or the socket is a client socket.

     Added in version 3.5.

 -- Metodo: SSLSocket.compression ()

     Return the compression algorithm being used as a string, or ‘None’
     if the connection isn’t compressed.

     If the higher-level protocol supports its own compression
     mechanism, you can use *note OP_NO_COMPRESSION: 134e. to disable
     SSL-level compression.

     Added in version 3.3.

 -- Metodo: SSLSocket.get_channel_binding (cb_type='tls-unique')

     Get channel binding data for current connection, as a bytes object.
     Returns ‘None’ if not connected or the handshake has not been
     completed.

     The 'cb_type' parameter allow selection of the desired channel
     binding type.  Valid channel binding types are listed in the *note
     CHANNEL_BINDING_TYPES: 39c4. list.  Currently only the “tls-unique”
     channel binding, defined by RFC 5929(2), is supported.  *note
     ValueError: 2ec. will be raised if an unsupported channel binding
     type is requested.

     Added in version 3.3.

 -- Metodo: SSLSocket.selected_alpn_protocol ()

     Return the protocol that was selected during the TLS handshake.  If
     *note SSLContext.set_alpn_protocols(): 1066. was not called, if the
     other party does not support ALPN, if this socket does not support
     any of the client’s proposed protocols, or if the handshake has not
     happened yet, ‘None’ is returned.

     Added in version 3.5.

 -- Metodo: SSLSocket.selected_npn_protocol ()

     Return the higher-level protocol that was selected during the
     TLS/SSL handshake.  If *note SSLContext.set_npn_protocols(): 358.
     was not called, or if the other party does not support NPN, or if
     the handshake has not yet happened, this will return ‘None’.

     Added in version 3.3.

     Deprecato dalla versione 3.10: NPN has been superseded by ALPN

 -- Metodo: SSLSocket.unwrap ()

     Performs the SSL shutdown handshake, which removes the TLS layer
     from the underlying socket, and returns the underlying socket
     object.  This can be used to go from encrypted operation over a
     connection to unencrypted.  The returned socket should always be
     used for further communication with the other side of the
     connection, rather than the original socket.

 -- Metodo: SSLSocket.verify_client_post_handshake ()

     Requests post-handshake authentication (PHA) from a TLS 1.3 client.
     PHA can only be initiated for a TLS 1.3 connection from a
     server-side socket, after the initial TLS handshake and with PHA
     enabled on both sides, see *note SSLContext.post_handshake_auth:
     c28.

     The method does not perform a cert exchange immediately.  The
     server-side sends a CertificateRequest during the next write event
     and expects the client to respond with a certificate on the next
     read event.

     If any precondition isn’t met (e.g.  not TLS 1.3, PHA not enabled),
     an *note SSLError: 1481. is raised.

          Nota: Only available with OpenSSL 1.1.1 and TLS 1.3 enabled.
          Without TLS 1.3 support, the method raises *note
          NotImplementedError: 36b.

     Added in version 3.8.

 -- Metodo: SSLSocket.version ()

     Return the actual SSL protocol version negotiated by the connection
     as a string, or ‘None’ if no secure connection is established.  As
     of this writing, possible return values include ‘"SSLv2"’,
     ‘"SSLv3"’, ‘"TLSv1"’, ‘"TLSv1.1"’ and ‘"TLSv1.2"’.  Recent OpenSSL
     versions may define more return values.

     Added in version 3.5.

 -- Metodo: SSLSocket.pending ()

     Returns the number of already decrypted bytes available for read,
     pending on the connection.

 -- Attributo: SSLSocket.context

     The *note SSLContext: 357. object this SSL socket is tied to.

     Added in version 3.2.

 -- Attributo: SSLSocket.server_side

     A boolean which is ‘True’ for server-side sockets and ‘False’ for
     client-side sockets.

     Added in version 3.2.

 -- Attributo: SSLSocket.server_hostname

     Hostname of the server: *note str: 169. type, or ‘None’ for
     server-side socket or if the hostname was not specified in the
     constructor.

     Added in version 3.2.

     Cambiato nella versione 3.7: The attribute is now always ASCII
     text.  When ‘server_hostname’ is an internationalized domain name
     (IDN), this attribute now stores the A-label form
     (‘"xn--pythn-mua.org"’), rather than the U-label form
     (‘"pythön.org"’).

 -- Attributo: SSLSocket.session

     The *note SSLSession: edb. for this SSL connection.  The session is
     available for client and server side sockets after the TLS
     handshake has been performed.  For client sockets the session can
     be set before *note do_handshake(): 106f. has been called to reuse
     a session.

     Added in version 3.6.

 -- Attributo: SSLSocket.session_reused

     Added in version 3.6.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc3280.html

   (2) https://datatracker.ietf.org/doc/html/rfc5929.html


File: python.info,  Node: SSL Contexts,  Next: Certificates,  Prev: SSL Sockets,  Up: ssl — TLS/SSL wrapper for socket objects

5.19.3.9 SSL Contexts
.....................

Added in version 3.2.

An SSL context holds various data longer-lived than single SSL
connections, such as SSL configuration options, certificate(s) and
private key(s).  It also manages a cache of SSL sessions for server-side
sockets, in order to speed up repeated connections from the same
clients.

 -- Classe: ssl.SSLContext (protocol=None)

     Create a new SSL context.  You may pass 'protocol' which must be
     one of the ‘PROTOCOL_*’ constants defined in this module.  The
     parameter specifies which version of the SSL protocol to use.
     Typically, the server chooses a particular protocol version, and
     the client must adapt to the server’s choice.  Most of the versions
     are not interoperable with the other versions.  If not specified,
     the default is *note PROTOCOL_TLS: 3999.; it provides the most
     compatibility with other versions.

     Here’s a table showing which versions in a client (down the side)
     can connect to which versions in a server (along the top):

     'client' / 'server'          'SSLv2'          'SSLv3'          'TLS' (1)         'TLSv1'       'TLSv1.1'       'TLSv1.2'
                                                                                                                    
                                                                                                                    
     'SSLv2'                      yes              no               no (2)            no            no              no
                                                                                                                    
                                                                                                                    
     'SSLv3'                      no               yes              no (3)            no            no              no
                                                                                                                    
                                                                                                                    
     'TLS' ('SSLv23') (4)         no (5)           no (6)           yes               yes           yes             yes
                                                                                                                    
                                                                                                                    
     'TLSv1'                      no               no               yes               yes           no              no
                                                                                                                    
                                                                                                                    
     'TLSv1.1'                    no               no               yes               no            yes             no
                                                                                                                    
                                                                                                                    
     'TLSv1.2'                    no               no               yes               no            no              yes
                                                                                                                    

     Vedi anche
     ..........

     *note create_default_context(): 480. lets the *note ssl: d5. module
     choose security settings for a given purpose.

     Cambiato nella versione 3.6: The context is created with secure
     default values.  The options *note OP_NO_COMPRESSION: 134e, *note
     OP_CIPHER_SERVER_PREFERENCE: 1351, *note OP_SINGLE_DH_USE: 39b5,
     *note OP_SINGLE_ECDH_USE: 39b6, *note OP_NO_SSLv2: a3c, and *note
     OP_NO_SSLv3: a3d. (except for *note PROTOCOL_SSLv3: 39a4.) are set
     by default.  The initial cipher suite list contains only ‘HIGH’
     ciphers, no ‘NULL’ ciphers and no ‘MD5’ ciphers.

     Deprecato dalla versione 3.10: *note SSLContext: 357. without
     protocol argument is deprecated.  The context class will either
     require *note PROTOCOL_TLS_CLIENT: a74. or *note
     PROTOCOL_TLS_SERVER: a75. protocol in the future.

     Cambiato nella versione 3.10: The default cipher suites now include
     only secure AES and ChaCha20 ciphers with forward secrecy and
     security level 2.  RSA and DH keys with less than 2048 bits and ECC
     keys with less than 224 bits are prohibited.  *note PROTOCOL_TLS:
     3999, *note PROTOCOL_TLS_CLIENT: a74, and *note
     PROTOCOL_TLS_SERVER: a75. use TLS 1.2 as minimum TLS version.

          Nota: *note SSLContext: 357. only supports limited mutation
          once it has been used by a connection.  Adding new
          certificates to the internal trust store is allowed, but
          changing ciphers, verification settings, or mTLS certificates
          may result in surprising behavior.

          Nota: *note SSLContext: 357. is designed to be shared and used
          by multiple connections.  Thus, it is thread-safe as long as
          it is not reconfigured after being used by a connection.

*note SSLContext: 357. objects have the following methods and
attributes:

 -- Metodo: SSLContext.cert_store_stats ()

     Get statistics about quantities of loaded X.509 certificates, count
     of X.509 certificates flagged as CA certificates and certificate
     revocation lists as dictionary.

     Example for a context with one CA cert and one other cert:

          >>> context.cert_store_stats()
          {'crl': 0, 'x509_ca': 1, 'x509': 2}

     Added in version 3.4.

 -- Metodo: SSLContext.load_cert_chain (certfile, keyfile=None,
          password=None)

     Load a private key and the corresponding certificate.  The
     'certfile' string must be the path to a single file in PEM format
     containing the certificate as well as any number of CA certificates
     needed to establish the certificate’s authenticity.  The 'keyfile'
     string, if present, must point to a file containing the private
     key.  Otherwise the private key will be taken from 'certfile' as
     well.  See the discussion of *note Certificates: 39d8. for more
     information on how the certificate is stored in the 'certfile'.

     The 'password' argument may be a function to call to get the
     password for decrypting the private key.  It will only be called if
     the private key is encrypted and a password is necessary.  It will
     be called with no arguments, and it should return a string, bytes,
     or bytearray.  If the return value is a string it will be encoded
     as UTF-8 before using it to decrypt the key.  Alternatively a
     string, bytes, or bytearray value may be supplied directly as the
     'password' argument.  It will be ignored if the private key is not
     encrypted and no password is needed.

     If the 'password' argument is not specified and a password is
     required, OpenSSL’s built-in password prompting mechanism will be
     used to interactively prompt the user for a password.

     An *note SSLError: 1481. is raised if the private key doesn’t match
     with the certificate.

     Cambiato nella versione 3.3: New optional argument 'password'.

 -- Metodo: SSLContext.load_default_certs (purpose=Purpose.SERVER_AUTH)

     Load a set of default «certification authority» (CA) certificates
     from default locations.  On Windows it loads CA certs from the ‘CA’
     and ‘ROOT’ system stores.  On all systems it calls *note
     SSLContext.set_default_verify_paths(): 11ad.  In the future the
     method may load CA certificates from other locations, too.

     The 'purpose' flag specifies what kind of CA certificates are
     loaded.  The default settings *note Purpose.SERVER_AUTH: 11b5.
     loads certificates, that are flagged and trusted for TLS web server
     authentication (client side sockets).  *note Purpose.CLIENT_AUTH:
     11b6. loads CA certificates for client certificate verification on
     the server side.

     Added in version 3.4.

 -- Metodo: SSLContext.load_verify_locations (cafile=None, capath=None,
          cadata=None)

     Load a set of «certification authority» (CA) certificates used to
     validate other peers” certificates when *note verify_mode: 3996. is
     other than *note CERT_NONE: 39a8.  At least one of 'cafile' or
     'capath' must be specified.

     This method can also load certification revocation lists (CRLs) in
     PEM or DER format.  In order to make use of CRLs, *note
     SSLContext.verify_flags: 11b0. must be configured properly.

     The 'cafile' string, if present, is the path to a file of
     concatenated CA certificates in PEM format.  See the discussion of
     *note Certificates: 39d8. for more information about how to arrange
     the certificates in this file.

     The 'capath' string, if present, is the path to a directory
     containing several CA certificates in PEM format, following an
     OpenSSL specific layout(7).

     The 'cadata' object, if present, is either an ASCII string of one
     or more PEM-encoded certificates or a *note bytes-like object: 193.
     of DER-encoded certificates.  Like with 'capath' extra lines around
     PEM-encoded certificates are ignored but at least one certificate
     must be present.

     Cambiato nella versione 3.4: New optional argument 'cadata'

 -- Metodo: SSLContext.get_ca_certs (binary_form=False)

     Get a list of loaded «certification authority» (CA) certificates.
     If the ‘binary_form’ parameter is *note False: d2d. each list entry
     is a dict like the output of *note SSLSocket.getpeercert(): 11ba.
     Otherwise the method returns a list of DER-encoded certificates.
     The returned list does not contain certificates from 'capath'
     unless a certificate was requested and loaded by a SSL connection.

          Nota: Certificates in a capath directory aren’t loaded unless
          they have been used at least once.

     Added in version 3.4.

 -- Metodo: SSLContext.get_ciphers ()

     Get a list of enabled ciphers.  The list is in order of cipher
     priority.  See *note SSLContext.set_ciphers(): 39d9.

     Example:

          >>> ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
          >>> ctx.set_ciphers('ECDHE+AESGCM:!ECDSA')
          >>> ctx.get_ciphers()
          [{'aead': True,
            'alg_bits': 256,
            'auth': 'auth-rsa',
            'description': 'ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  '
                           'Enc=AESGCM(256) Mac=AEAD',
            'digest': None,
            'id': 50380848,
            'kea': 'kx-ecdhe',
            'name': 'ECDHE-RSA-AES256-GCM-SHA384',
            'protocol': 'TLSv1.2',
            'strength_bits': 256,
            'symmetric': 'aes-256-gcm'},
           {'aead': True,
            'alg_bits': 128,
            'auth': 'auth-rsa',
            'description': 'ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  '
                           'Enc=AESGCM(128) Mac=AEAD',
            'digest': None,
            'id': 50380847,
            'kea': 'kx-ecdhe',
            'name': 'ECDHE-RSA-AES128-GCM-SHA256',
            'protocol': 'TLSv1.2',
            'strength_bits': 128,
            'symmetric': 'aes-128-gcm'}]

     Added in version 3.6.

 -- Metodo: SSLContext.set_default_verify_paths ()

     Load a set of default «certification authority» (CA) certificates
     from a filesystem path defined when building the OpenSSL library.
     Unfortunately, there’s no easy way to know whether this method
     succeeds: no error is returned if no certificates are to be found.
     When the OpenSSL library is provided as part of the operating
     system, though, it is likely to be configured properly.

 -- Metodo: SSLContext.set_ciphers (ciphers, /)

     Set the available ciphers for sockets created with this context.
     It should be a string in the OpenSSL cipher list format(8).  If no
     cipher can be selected (because compile-time options or other
     configuration forbids use of all the specified ciphers), an *note
     SSLError: 1481. will be raised.

          Nota: when connected, the *note SSLSocket.cipher(): 38c0.
          method of SSL sockets will give the currently selected cipher.

          TLS 1.3 cipher suites cannot be disabled with *note
          set_ciphers(): 39d9.

 -- Metodo: SSLContext.set_alpn_protocols (alpn_protocols)

     Specify which protocols the socket should advertise during the
     SSL/TLS handshake.  It should be a list of ASCII strings, like
     ‘['http/1.1', 'spdy/2']’, ordered by preference.  The selection of
     a protocol will happen during the handshake, and will play out
     according to RFC 7301(9).  After a successful handshake, the *note
     SSLSocket.selected_alpn_protocol(): 1067. method will return the
     agreed-upon protocol.

     This method will raise *note NotImplementedError: 36b. if *note
     HAS_ALPN: 1068. is ‘False’.

     Added in version 3.5.

 -- Metodo: SSLContext.set_npn_protocols (npn_protocols)

     Specify which protocols the socket should advertise during the
     SSL/TLS handshake.  It should be a list of strings, like
     ‘['http/1.1', 'spdy/2']’, ordered by preference.  The selection of
     a protocol will happen during the handshake, and will play out
     according to the Application Layer Protocol Negotiation(10).  After
     a successful handshake, the *note
     SSLSocket.selected_npn_protocol(): a76. method will return the
     agreed-upon protocol.

     This method will raise *note NotImplementedError: 36b. if *note
     HAS_NPN: 39bd. is ‘False’.

     Added in version 3.3.

     Deprecato dalla versione 3.10: NPN has been superseded by ALPN

 -- Attributo: SSLContext.sni_callback

     Register a callback function that will be called after the TLS
     Client Hello handshake message has been received by the SSL/TLS
     server when the TLS client specifies a server name indication.  The
     server name indication mechanism is specified in RFC 6066(11)
     section 3 - Server Name Indication.

     Only one callback can be set per ‘SSLContext’.  If 'sni_callback'
     is set to ‘None’ then the callback is disabled.  Calling this
     function a subsequent time will disable the previously registered
     callback.

     The callback function will be called with three arguments; the
     first being the *note ssl.SSLSocket: ae9, the second is a string
     that represents the server name that the client is intending to
     communicate (or *note None: 886. if the TLS Client Hello does not
     contain a server name) and the third argument is the original *note
     SSLContext: 357.  The server name argument is text.  For
     internationalized domain name, the server name is an IDN A-label
     (‘"xn--pythn-mua.org"’).

     A typical use of this callback is to change the *note
     ssl.SSLSocket: ae9.’s *note SSLSocket.context: 39d3. attribute to a
     new object of type *note SSLContext: 357. representing a
     certificate chain that matches the server name.

     Due to the early negotiation phase of the TLS connection, only
     limited methods and attributes are usable like *note
     SSLSocket.selected_alpn_protocol(): 1067. and *note
     SSLSocket.context: 39d3.  The *note SSLSocket.getpeercert(): 11ba,
     *note SSLSocket.get_verified_chain(): 1944, *note
     SSLSocket.get_unverified_chain(): 1945. *note SSLSocket.cipher():
     38c0. and *note SSLSocket.compression(): 134d. methods require that
     the TLS connection has progressed beyond the TLS Client Hello and
     therefore will not return meaningful values nor can they be called
     safely.

     The 'sni_callback' function must return ‘None’ to allow the TLS
     negotiation to continue.  If a TLS failure is required, a constant
     *note ALERT_DESCRIPTION_*: 39c6. can be returned.  Other return
     values will result in a TLS fatal error with *note
     ALERT_DESCRIPTION_INTERNAL_ERROR: 39c6.

     If an exception is raised from the 'sni_callback' function the TLS
     connection will terminate with a fatal TLS alert message *note
     ALERT_DESCRIPTION_HANDSHAKE_FAILURE: 39c5.

     This method will raise *note NotImplementedError: 36b. if the
     OpenSSL library had OPENSSL_NO_TLSEXT defined when it was built.

     Added in version 3.7.

 -- Metodo: SSLContext.set_servername_callback (server_name_callback)

     This is a legacy API retained for backwards compatibility.  When
     possible, you should use *note sni_callback: 1c77. instead.  The
     given 'server_name_callback' is similar to 'sni_callback', except
     that when the server hostname is an IDN-encoded internationalized
     domain name, the 'server_name_callback' receives a decoded U-label
     (‘"pythön.org"’).

     If there is a decoding error on the server name, the TLS connection
     will terminate with an *note ALERT_DESCRIPTION_INTERNAL_ERROR:
     39c6. fatal TLS alert message to the client.

     Added in version 3.4.

 -- Metodo: SSLContext.load_dh_params (dhfile, /)

     Load the key generation parameters for Diffie-Hellman (DH) key
     exchange.  Using DH key exchange improves forward secrecy at the
     expense of computational resources (both on the server and on the
     client).  The 'dhfile' parameter should be the path to a file
     containing DH parameters in PEM format.

     This setting doesn’t apply to client sockets.  You can also use the
     *note OP_SINGLE_DH_USE: 39b5. option to further improve security.

     Added in version 3.3.

 -- Metodo: SSLContext.set_ecdh_curve (curve_name, /)

     Set the curve name for Elliptic Curve-based Diffie-Hellman (ECDH)
     key exchange.  ECDH is significantly faster than regular DH while
     arguably as secure.  The 'curve_name' parameter should be a string
     describing a well-known elliptic curve, for example ‘prime256v1’
     for a widely supported curve.

     This setting doesn’t apply to client sockets.  You can also use the
     *note OP_SINGLE_ECDH_USE: 39b6. option to further improve security.

     This method is not available if *note HAS_ECDH: 39bb. is ‘False’.

     Added in version 3.3.

     Vedi anche
     ..........

     SSL/TLS & Perfect Forward Secrecy(12)

          Vincent Bernat.

 -- Metodo: SSLContext.wrap_socket (sock, server_side=False,
          do_handshake_on_connect=True, suppress_ragged_eofs=True,
          server_hostname=None, session=None)

     Wrap an existing Python socket 'sock' and return an instance of
     *note SSLContext.sslsocket_class: 39da. (default *note SSLSocket:
     ae9.).  The returned SSL socket is tied to the context, its
     settings and certificates.  'sock' must be a *note SOCK_STREAM:
     14fb. socket; other socket types are unsupported.

     The parameter ‘server_side’ is a boolean which identifies whether
     server-side or client-side behavior is desired from this socket.

     For client-side sockets, the context construction is lazy; if the
     underlying socket isn’t connected yet, the context construction
     will be performed after ‘connect()’ is called on the socket.  For
     server-side sockets, if the socket has no remote peer, it is
     assumed to be a listening socket, and the server-side SSL wrapping
     is automatically performed on client connections accepted via the
     ‘accept()’ method.  The method may raise *note SSLError: 1481.

     On client connections, the optional parameter 'server_hostname'
     specifies the hostname of the service which we are connecting to.
     This allows a single server to host multiple SSL-based services
     with distinct certificates, quite similarly to HTTP virtual hosts.
     Specifying 'server_hostname' will raise a *note ValueError: 2ec. if
     'server_side' is true.

     The parameter ‘do_handshake_on_connect’ specifies whether to do the
     SSL handshake automatically after doing a ‘socket.connect()’, or
     whether the application program will call it explicitly, by
     invoking the *note SSLSocket.do_handshake(): 106f. method.  Calling
     *note SSLSocket.do_handshake(): 106f. explicitly gives the program
     control over the blocking behavior of the socket I/O involved in
     the handshake.

     The parameter ‘suppress_ragged_eofs’ specifies how the
     ‘SSLSocket.recv()’ method should signal unexpected EOF from the
     other end of the connection.  If specified as *note True: e09. (the
     default), it returns a normal EOF (an empty bytes object) in
     response to unexpected EOF errors raised from the underlying
     socket; if *note False: d2d, it will raise the exceptions back to
     the caller.

     'session', see *note session: 1925.

     To wrap an *note SSLSocket: ae9. in another *note SSLSocket: ae9,
     use *note SSLContext.wrap_bio(): d7d.

     Cambiato nella versione 3.5: Always allow a server_hostname to be
     passed, even if OpenSSL does not have SNI.

     Cambiato nella versione 3.6: 'session' argument was added.

     Cambiato nella versione 3.7: The method returns an instance of
     *note SSLContext.sslsocket_class: 39da. instead of hard-coded *note
     SSLSocket: ae9.

 -- Attributo: SSLContext.sslsocket_class

     The return type of *note SSLContext.wrap_socket(): 749, defaults to
     *note SSLSocket: ae9.  The attribute can be assigned to on
     instances of *note SSLContext: 357. in order to return a custom
     subclass of *note SSLSocket: ae9.

     Added in version 3.7.

 -- Metodo: SSLContext.wrap_bio (incoming, outgoing, server_side=False,
          server_hostname=None, session=None)

     Wrap the BIO objects 'incoming' and 'outgoing' and return an
     instance of *note SSLContext.sslobject_class: 39db. (default *note
     SSLObject: d7c.).  The SSL routines will read input data from the
     incoming BIO and write data to the outgoing BIO.

     The 'server_side', 'server_hostname' and 'session' parameters have
     the same meaning as in *note SSLContext.wrap_socket(): 749.

     Cambiato nella versione 3.6: 'session' argument was added.

     Cambiato nella versione 3.7: The method returns an instance of
     *note SSLContext.sslobject_class: 39db. instead of hard-coded *note
     SSLObject: d7c.

 -- Attributo: SSLContext.sslobject_class

     The return type of *note SSLContext.wrap_bio(): d7d, defaults to
     *note SSLObject: d7c.  The attribute can be overridden on instance
     of class in order to return a custom subclass of *note SSLObject:
     d7c.

     Added in version 3.7.

 -- Metodo: SSLContext.session_stats ()

     Get statistics about the SSL sessions created or managed by this
     context.  A dictionary is returned which maps the names of each
     piece of information(13) to their numeric values.  For example,
     here is the total number of hits and misses in the session cache
     since the context was created:

          >>> stats = context.session_stats()
          >>> stats['hits'], stats['misses']
          (0, 0)

 -- Attributo: SSLContext.check_hostname

     Whether to match the peer cert’s hostname in *note
     SSLSocket.do_handshake(): 106f.  The context’s *note verify_mode:
     3996. must be set to *note CERT_OPTIONAL: 39a9. or *note
     CERT_REQUIRED: 3997, and you must pass 'server_hostname' to *note
     wrap_socket(): 749. in order to match the hostname.  Enabling
     hostname checking automatically sets *note verify_mode: 3996. from
     *note CERT_NONE: 39a8. to *note CERT_REQUIRED: 3997.  It cannot be
     set back to *note CERT_NONE: 39a8. as long as hostname checking is
     enabled.  The *note PROTOCOL_TLS_CLIENT: a74. protocol enables
     hostname checking by default.  With other protocols, hostname
     checking must be enabled explicitly.

     Example:

          import socket, ssl

          context = ssl.SSLContext(ssl.PROTOCOL_TLSv1_2)
          context.verify_mode = ssl.CERT_REQUIRED
          context.check_hostname = True
          context.load_default_certs()

          s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
          ssl_sock = context.wrap_socket(s, server_hostname='www.verisign.com')
          ssl_sock.connect(('www.verisign.com', 443))

     Added in version 3.4.

     Cambiato nella versione 3.7: *note verify_mode: 3996. is now
     automatically changed to *note CERT_REQUIRED: 3997. when hostname
     checking is enabled and *note verify_mode: 3996. is *note
     CERT_NONE: 39a8.  Previously the same operation would have failed
     with a *note ValueError: 2ec.

 -- Attributo: SSLContext.keylog_filename

     Write TLS keys to a keylog file, whenever key material is generated
     or received.  The keylog file is designed for debugging purposes
     only.  The file format is specified by NSS and used by many traffic
     analyzers such as Wireshark.  The log file is opened in append-only
     mode.  Writes are synchronized between threads, but not between
     processes.

     Added in version 3.8.

 -- Attributo: SSLContext.maximum_version

     A *note TLSVersion: 39c9. enum member representing the highest
     supported TLS version.  The value defaults to *note
     TLSVersion.MAXIMUM_SUPPORTED: 39cb.  The attribute is read-only for
     protocols other than *note PROTOCOL_TLS: 3999, *note
     PROTOCOL_TLS_CLIENT: a74, and *note PROTOCOL_TLS_SERVER: a75.

     The attributes *note maximum_version: a73, *note minimum_version:
     a72. and *note SSLContext.options: a3b. all affect the supported
     SSL and TLS versions of the context.  The implementation does not
     prevent invalid combination.  For example a context with *note
     OP_NO_TLSv1_2: 39b3. in *note options: a3b. and *note
     maximum_version: a73. set to *note TLSVersion.TLSv1_2: 39cf. will
     not be able to establish a TLS 1.2 connection.

     Added in version 3.7.

 -- Attributo: SSLContext.minimum_version

     Like *note SSLContext.maximum_version: a73. except it is the lowest
     supported version or *note TLSVersion.MINIMUM_SUPPORTED: 39ca.

     Added in version 3.7.

 -- Attributo: SSLContext.num_tickets

     Control the number of TLS 1.3 session tickets of a *note
     PROTOCOL_TLS_SERVER: a75. context.  The setting has no impact on
     TLS 1.0 to 1.2 connections.

     Added in version 3.8.

 -- Attributo: SSLContext.options

     An integer representing the set of SSL options enabled on this
     context.  The default value is *note OP_ALL: 39b0, but you can
     specify other options such as *note OP_NO_SSLv2: a3c. by ORing them
     together.

     Cambiato nella versione 3.6: *note SSLContext.options: a3b. returns
     *note Options: 39b8. flags:

          >>> ssl.create_default_context().options
          <Options.OP_ALL|OP_NO_SSLv3|OP_NO_SSLv2|OP_NO_COMPRESSION: 2197947391>

     Deprecato dalla versione 3.7: All ‘OP_NO_SSL*’ and ‘OP_NO_TLS*’
     options have been deprecated since Python 3.7.  Use *note
     SSLContext.minimum_version: a72. and *note
     SSLContext.maximum_version: a73. instead.

 -- Attributo: SSLContext.post_handshake_auth

     Enable TLS 1.3 post-handshake client authentication.
     Post-handshake auth is disabled by default and a server can only
     request a TLS client certificate during the initial handshake.
     When enabled, a server may request a TLS client certificate at any
     time after the handshake.

     When enabled on client-side sockets, the client signals the server
     that it supports post-handshake authentication.

     When enabled on server-side sockets, *note SSLContext.verify_mode:
     3996. must be set to *note CERT_OPTIONAL: 39a9. or *note
     CERT_REQUIRED: 3997, too.  The actual client cert exchange is
     delayed until *note SSLSocket.verify_client_post_handshake(): c29.
     is called and some I/O is performed.

     Added in version 3.8.

 -- Attributo: SSLContext.protocol

     The protocol version chosen when constructing the context.  This
     attribute is read-only.

 -- Attributo: SSLContext.hostname_checks_common_name

     Whether *note check_hostname: 39aa. falls back to verify the cert’s
     subject common name in the absence of a subject alternative name
     extension (default: true).

     Added in version 3.7.

     Cambiato nella versione 3.10: The flag had no effect with OpenSSL
     before version 1.1.1l.  Python 3.8.9, 3.9.3, and 3.10 include
     workarounds for previous versions.

 -- Attributo: SSLContext.security_level

     An integer representing the security level(14) for the context.
     This attribute is read-only.

     Added in version 3.10.

 -- Attributo: SSLContext.verify_flags

     The flags for certificate verification operations.  You can set
     flags like *note VERIFY_CRL_CHECK_LEAF: 11b2. by ORing them
     together.  By default OpenSSL does neither require nor verify
     certificate revocation lists (CRLs).

     Added in version 3.4.

     Cambiato nella versione 3.6: *note SSLContext.verify_flags: 11b0.
     returns *note VerifyFlags: 39ad. flags:

          >>> ssl.create_default_context().verify_flags
          <VerifyFlags.VERIFY_X509_TRUSTED_FIRST: 32768>

 -- Attributo: SSLContext.verify_mode

     Whether to try to verify other peers” certificates and how to
     behave if verification fails.  This attribute must be one of *note
     CERT_NONE: 39a8, *note CERT_OPTIONAL: 39a9. or *note CERT_REQUIRED:
     3997.

     Cambiato nella versione 3.6: *note SSLContext.verify_mode: 3996.
     returns *note VerifyMode: 39ab. enum:

          >>> ssl.create_default_context().verify_mode
          <VerifyMode.CERT_REQUIRED: 2>

 -- Metodo: SSLContext.set_psk_client_callback (callback)

     Enables TLS-PSK (pre-shared key) authentication on a client-side
     connection.

     In general, certificate based authentication should be preferred
     over this method.

     The parameter ‘callback’ is a callable object with the signature:
     ‘def callback(hint: str | None) -> tuple[str | None, bytes]’.  The
     ‘hint’ parameter is an optional identity hint sent by the server.
     The return value is a tuple in the form (client-identity, psk).
     Client-identity is an optional string which may be used by the
     server to select a corresponding PSK for the client.  The string
     must be less than or equal to ‘256’ octets when UTF-8 encoded.  PSK
     is a *note bytes-like object: 193. representing the pre-shared key.
     Return a zero length PSK to reject the connection.

     Setting ‘callback’ to *note None: 886. removes any existing
     callback.

          Nota: When using TLS 1.3:

             - the ‘hint’ parameter is always *note None: 886.

             - client-identity must be a non-empty string.

     Example usage:

          context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
          context.check_hostname = False
          context.verify_mode = ssl.CERT_NONE
          context.maximum_version = ssl.TLSVersion.TLSv1_2
          context.set_ciphers('PSK')

          # A simple lambda:
          psk = bytes.fromhex('c0ffee')
          context.set_psk_client_callback(lambda hint: (None, psk))

          # A table using the hint from the server:
          psk_table = { 'ServerId_1': bytes.fromhex('c0ffee'),
                        'ServerId_2': bytes.fromhex('facade')
          }
          def callback(hint):
              return 'ClientId_1', psk_table.get(hint, b'')
          context.set_psk_client_callback(callback)

     This method will raise *note NotImplementedError: 36b. if *note
     HAS_PSK: 39c3. is ‘False’.

     Added in version 3.13.

 -- Metodo: SSLContext.set_psk_server_callback (callback,
          identity_hint=None)

     Enables TLS-PSK (pre-shared key) authentication on a server-side
     connection.

     In general, certificate based authentication should be preferred
     over this method.

     The parameter ‘callback’ is a callable object with the signature:
     ‘def callback(identity: str | None) -> bytes’.  The ‘identity’
     parameter is an optional identity sent by the client which can be
     used to select a corresponding PSK. The return value is a *note
     bytes-like object: 193. representing the pre-shared key.  Return a
     zero length PSK to reject the connection.

     Setting ‘callback’ to *note None: 886. removes any existing
     callback.

     The parameter ‘identity_hint’ is an optional identity hint string
     sent to the client.  The string must be less than or equal to ‘256’
     octets when UTF-8 encoded.

          Nota: When using TLS 1.3 the ‘identity_hint’ parameter is not
          sent to the client.

     Example usage:

          context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
          context.maximum_version = ssl.TLSVersion.TLSv1_2
          context.set_ciphers('PSK')

          # A simple lambda:
          psk = bytes.fromhex('c0ffee')
          context.set_psk_server_callback(lambda identity: psk)

          # A table using the identity of the client:
          psk_table = { 'ClientId_1': bytes.fromhex('c0ffee'),
                        'ClientId_2': bytes.fromhex('facade')
          }
          def callback(identity):
              return psk_table.get(identity, b'')
          context.set_psk_server_callback(callback, 'ServerId_1')

     This method will raise *note NotImplementedError: 36b. if *note
     HAS_PSK: 39c3. is ‘False’.

     Added in version 3.13.

   ---------- Footnotes ----------

   (1) TLS 1.3 protocol will be available with *note PROTOCOL_TLS: 3999.
in OpenSSL >= 1.1.1.  There is no dedicated PROTOCOL constant for just
TLS 1.3.

   (2) *note SSLContext: 357. disables SSLv2 with *note OP_NO_SSLv2:
a3c. by default.

   (3) *note SSLContext: 357. disables SSLv3 with *note OP_NO_SSLv3:
a3d. by default.

   (4) TLS 1.3 protocol will be available with *note PROTOCOL_TLS: 3999.
in OpenSSL >= 1.1.1.  There is no dedicated PROTOCOL constant for just
TLS 1.3.

   (5) *note SSLContext: 357. disables SSLv2 with *note OP_NO_SSLv2:
a3c. by default.

   (6) *note SSLContext: 357. disables SSLv3 with *note OP_NO_SSLv3:
a3d. by default.

   (7) 
https://docs.openssl.org/master/man3/SSL_CTX_load_verify_locations/

   (8) https://docs.openssl.org/master/man1/ciphers/

   (9) https://datatracker.ietf.org/doc/html/rfc7301.html

   (10) 
https://en.wikipedia.org/wiki/Application-Layer_Protocol_Negotiation

   (11) https://datatracker.ietf.org/doc/html/rfc6066.html

   (12) 
https://vincent.bernat.ch/en/blog/2011-ssl-perfect-forward-secrecy

   (13) https://docs.openssl.org/1.1.1/man3/SSL_CTX_sess_number/

   (14) https://docs.openssl.org/master/man3/SSL_CTX_get_security_level/


File: python.info,  Node: Certificates,  Next: Examples<21>,  Prev: SSL Contexts,  Up: ssl — TLS/SSL wrapper for socket objects

5.19.3.10 Certificates
......................

Certificates in general are part of a public-key / private-key system.
In this system, each 'principal', (which may be a machine, or a person,
or an organization) is assigned a unique two-part encryption key.  One
part of the key is public, and is called the 'public key'; the other
part is kept secret, and is called the 'private key'.  The two parts are
related, in that if you encrypt a message with one of the parts, you can
decrypt it with the other part, and 'only' with the other part.

A certificate contains information about two principals.  It contains
the name of a 'subject', and the subject’s public key.  It also contains
a statement by a second principal, the 'issuer', that the subject is who
they claim to be, and that this is indeed the subject’s public key.  The
issuer’s statement is signed with the issuer’s private key, which only
the issuer knows.  However, anyone can verify the issuer’s statement by
finding the issuer’s public key, decrypting the statement with it, and
comparing it to the other information in the certificate.  The
certificate also contains information about the time period over which
it is valid.  This is expressed as two fields, called «notBefore» and
«notAfter».

In the Python use of certificates, a client or server can use a
certificate to prove who they are.  The other side of a network
connection can also be required to produce a certificate, and that
certificate can be validated to the satisfaction of the client or server
that requires such validation.  The connection attempt can be set to
raise an exception if the validation fails.  Validation is done
automatically, by the underlying OpenSSL framework; the application need
not concern itself with its mechanics.  But the application does usually
need to provide sets of certificates to allow this process to take
place.

Python uses files to contain certificates.  They should be formatted as
«PEM» (see RFC 1422(1)), which is a base-64 encoded form wrapped with a
header line and a footer line:

     -----BEGIN CERTIFICATE-----
     ... (certificate in base64 PEM encoding) ...
     -----END CERTIFICATE-----

* Menu:

* Certificate chains::
* CA certificates::
* Combined key and certificate::
* Self-signed certificates::

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc1422.html


File: python.info,  Node: Certificate chains,  Next: CA certificates,  Up: Certificates

5.19.3.11 Certificate chains
............................

The Python files which contain certificates can contain a sequence of
certificates, sometimes called a 'certificate chain'.  This chain should
start with the specific certificate for the principal who «is» the
client or server, and then the certificate for the issuer of that
certificate, and then the certificate for the issuer of 'that'
certificate, and so on up the chain till you get to a certificate which
is 'self-signed', that is, a certificate which has the same subject and
issuer, sometimes called a 'root certificate'.  The certificates should
just be concatenated together in the certificate file.  For example,
suppose we had a three certificate chain, from our server certificate to
the certificate of the certification authority that signed our server
certificate, to the root certificate of the agency which issued the
certification authority’s certificate:

     -----BEGIN CERTIFICATE-----
     ... (certificate for your server)...
     -----END CERTIFICATE-----
     -----BEGIN CERTIFICATE-----
     ... (the certificate for the CA)...
     -----END CERTIFICATE-----
     -----BEGIN CERTIFICATE-----
     ... (the root certificate for the CA's issuer)...
     -----END CERTIFICATE-----


File: python.info,  Node: CA certificates,  Next: Combined key and certificate,  Prev: Certificate chains,  Up: Certificates

5.19.3.12 CA certificates
.........................

If you are going to require validation of the other side of the
connection’s certificate, you need to provide a «CA certs» file, filled
with the certificate chains for each issuer you are willing to trust.
Again, this file just contains these chains concatenated together.  For
validation, Python will use the first chain it finds in the file which
matches.  The platform’s certificates file can be used by calling *note
SSLContext.load_default_certs(): 11b4, this is done automatically with
*note create_default_context(): 480.


File: python.info,  Node: Combined key and certificate,  Next: Self-signed certificates,  Prev: CA certificates,  Up: Certificates

5.19.3.13 Combined key and certificate
......................................

Often the private key is stored in the same file as the certificate; in
this case, only the ‘certfile’ parameter to *note
SSLContext.load_cert_chain(): 598. needs to be passed.  If the private
key is stored with the certificate, it should come before the first
certificate in the certificate chain:

     -----BEGIN RSA PRIVATE KEY-----
     ... (private key in base64 encoding) ...
     -----END RSA PRIVATE KEY-----
     -----BEGIN CERTIFICATE-----
     ... (certificate in base64 PEM encoding) ...
     -----END CERTIFICATE-----


File: python.info,  Node: Self-signed certificates,  Prev: Combined key and certificate,  Up: Certificates

5.19.3.14 Self-signed certificates
..................................

If you are going to create a server that provides SSL-encrypted
connection services, you will need to acquire a certificate for that
service.  There are many ways of acquiring appropriate certificates,
such as buying one from a certification authority.  Another common
practice is to generate a self-signed certificate.  The simplest way to
do this is with the OpenSSL package, using something like the following:

     % openssl req -new -x509 -days 365 -nodes -out cert.pem -keyout cert.pem
     Generating a 1024 bit RSA private key
     .......++++++
     .............................++++++
     writing new private key to 'cert.pem'
     -----
     You are about to be asked to enter information that will be incorporated
     into your certificate request.
     What you are about to enter is what is called a Distinguished Name or a DN.
     There are quite a few fields but you can leave some blank
     For some fields there will be a default value,
     If you enter '.', the field will be left blank.
     -----
     Country Name (2 letter code) [AU]:US
     State or Province Name (full name) [Some-State]:MyState
     Locality Name (eg, city) []:Some City
     Organization Name (eg, company) [Internet Widgits Pty Ltd]:My Organization, Inc.
     Organizational Unit Name (eg, section) []:My Group
     Common Name (eg, YOUR name) []:myserver.mygroup.myorganization.com
     Email Address []:ops@myserver.mygroup.myorganization.com
     %

The disadvantage of a self-signed certificate is that it is its own root
certificate, and no one else will have it in their cache of known (and
trusted) root certificates.


File: python.info,  Node: Examples<21>,  Next: Notes on non-blocking sockets,  Prev: Certificates,  Up: ssl — TLS/SSL wrapper for socket objects

5.19.3.15 Examples
..................

* Menu:

* Testing for SSL support::
* Client-side operation::
* Server-side operation::


File: python.info,  Node: Testing for SSL support,  Next: Client-side operation,  Up: Examples<21>

5.19.3.16 Testing for SSL support
.................................

To test for the presence of SSL support in a Python installation, user
code should use the following idiom:

     try:
         import ssl
     except ImportError:
         pass
     else:
         ...  # do something that requires SSL support


File: python.info,  Node: Client-side operation,  Next: Server-side operation,  Prev: Testing for SSL support,  Up: Examples<21>

5.19.3.17 Client-side operation
...............................

This example creates a SSL context with the recommended security
settings for client sockets, including automatic certificate
verification:

     >>> context = ssl.create_default_context()

If you prefer to tune security settings yourself, you might create a
context from scratch (but beware that you might not get the settings
right):

     >>> context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
     >>> context.load_verify_locations("/etc/ssl/certs/ca-bundle.crt")

(this snippet assumes your operating system places a bundle of all CA
certificates in ‘/etc/ssl/certs/ca-bundle.crt’; if not, you’ll get an
error and have to adjust the location)

The *note PROTOCOL_TLS_CLIENT: a74. protocol configures the context for
cert validation and hostname verification.  *note verify_mode: 3996. is
set to *note CERT_REQUIRED: 3997. and *note check_hostname: 39aa. is set
to ‘True’.  All other protocols create SSL contexts with insecure
defaults.

When you use the context to connect to a server, *note CERT_REQUIRED:
3997. and *note check_hostname: 39aa. validate the server certificate:
it ensures that the server certificate was signed with one of the CA
certificates, checks the signature for correctness, and verifies other
properties like validity and identity of the hostname:

     >>> conn = context.wrap_socket(socket.socket(socket.AF_INET),
     ...                            server_hostname="www.python.org")
     >>> conn.connect(("www.python.org", 443))

You may then fetch the certificate:

     >>> cert = conn.getpeercert()

Visual inspection shows that the certificate does identify the desired
service (that is, the HTTPS host ‘www.python.org’):

     >>> pprint.pprint(cert)
     {'OCSP': ('http://ocsp.digicert.com',),
      'caIssuers': ('http://cacerts.digicert.com/DigiCertSHA2ExtendedValidationServerCA.crt',),
      'crlDistributionPoints': ('http://crl3.digicert.com/sha2-ev-server-g1.crl',
                                'http://crl4.digicert.com/sha2-ev-server-g1.crl'),
      'issuer': ((('countryName', 'US'),),
                 (('organizationName', 'DigiCert Inc'),),
                 (('organizationalUnitName', 'www.digicert.com'),),
                 (('commonName', 'DigiCert SHA2 Extended Validation Server CA'),)),
      'notAfter': 'Sep  9 12:00:00 2016 GMT',
      'notBefore': 'Sep  5 00:00:00 2014 GMT',
      'serialNumber': '01BB6F00122B177F36CAB49CEA8B6B26',
      'subject': ((('businessCategory', 'Private Organization'),),
                  (('1.3.6.1.4.1.311.60.2.1.3', 'US'),),
                  (('1.3.6.1.4.1.311.60.2.1.2', 'Delaware'),),
                  (('serialNumber', '3359300'),),
                  (('streetAddress', '16 Allen Rd'),),
                  (('postalCode', '03894-4801'),),
                  (('countryName', 'US'),),
                  (('stateOrProvinceName', 'NH'),),
                  (('localityName', 'Wolfeboro'),),
                  (('organizationName', 'Python Software Foundation'),),
                  (('commonName', 'www.python.org'),)),
      'subjectAltName': (('DNS', 'www.python.org'),
                         ('DNS', 'python.org'),
                         ('DNS', 'pypi.org'),
                         ('DNS', 'docs.python.org'),
                         ('DNS', 'testpypi.org'),
                         ('DNS', 'bugs.python.org'),
                         ('DNS', 'wiki.python.org'),
                         ('DNS', 'hg.python.org'),
                         ('DNS', 'mail.python.org'),
                         ('DNS', 'packaging.python.org'),
                         ('DNS', 'pythonhosted.org'),
                         ('DNS', 'www.pythonhosted.org'),
                         ('DNS', 'test.pythonhosted.org'),
                         ('DNS', 'us.pycon.org'),
                         ('DNS', 'id.python.org')),
      'version': 3}

Now the SSL channel is established and the certificate verified, you can
proceed to talk with the server:

     >>> conn.sendall(b"HEAD / HTTP/1.0\r\nHost: linuxfr.org\r\n\r\n")
     >>> pprint.pprint(conn.recv(1024).split(b"\r\n"))
     [b'HTTP/1.1 200 OK',
      b'Date: Sat, 18 Oct 2014 18:27:20 GMT',
      b'Server: nginx',
      b'Content-Type: text/html; charset=utf-8',
      b'X-Frame-Options: SAMEORIGIN',
      b'Content-Length: 45679',
      b'Accept-Ranges: bytes',
      b'Via: 1.1 varnish',
      b'Age: 2188',
      b'X-Served-By: cache-lcy1134-LCY',
      b'X-Cache: HIT',
      b'X-Cache-Hits: 11',
      b'Vary: Cookie',
      b'Strict-Transport-Security: max-age=63072000; includeSubDomains',
      b'Connection: close',
      b'',
      b'']

See the discussion of *note Security considerations: 387b. below.


File: python.info,  Node: Server-side operation,  Prev: Client-side operation,  Up: Examples<21>

5.19.3.18 Server-side operation
...............................

For server operation, typically you’ll need to have a server
certificate, and private key, each in a file.  You’ll first create a
context holding the key and the certificate, so that clients can check
your authenticity.  Then you’ll open a socket, bind it to a port, call
‘listen()’ on it, and start waiting for clients to connect:

     import socket, ssl

     context = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)
     context.load_cert_chain(certfile="mycertfile", keyfile="mykeyfile")

     bindsocket = socket.socket()
     bindsocket.bind(('myaddr.example.com', 10023))
     bindsocket.listen(5)

When a client connects, you’ll call ‘accept()’ on the socket to get the
new socket from the other end, and use the context’s *note
SSLContext.wrap_socket(): 749. method to create a server-side SSL socket
for the connection:

     while True:
         newsocket, fromaddr = bindsocket.accept()
         connstream = context.wrap_socket(newsocket, server_side=True)
         try:
             deal_with_client(connstream)
         finally:
             connstream.shutdown(socket.SHUT_RDWR)
             connstream.close()

Then you’ll read data from the ‘connstream’ and do something with it
till you are finished with the client (or the client is finished with
you):

     def deal_with_client(connstream):
         data = connstream.recv(1024)
         # empty data means the client is finished with us
         while data:
             if not do_something(connstream, data):
                 # we'll assume do_something returns False
                 # when we're finished with client
                 break
             data = connstream.recv(1024)
         # finished with client

And go back to listening for new client connections (of course, a real
server would probably handle each client connection in a separate
thread, or put the sockets in *note non-blocking mode: 399c. and use an
event loop).


File: python.info,  Node: Notes on non-blocking sockets,  Next: Memory BIO Support<2>,  Prev: Examples<21>,  Up: ssl — TLS/SSL wrapper for socket objects

5.19.3.19 Notes on non-blocking sockets
.......................................

SSL sockets behave slightly different than regular sockets in
non-blocking mode.  When working with non-blocking sockets, there are
thus several things you need to be aware of:

   - Most *note SSLSocket: ae9. methods will raise either *note
     SSLWantWriteError: 106c. or *note SSLWantReadError: 106b. instead
     of *note BlockingIOError: 235. if an I/O operation would block.
     *note SSLWantReadError: 106b. will be raised if a read operation on
     the underlying socket is necessary, and *note SSLWantWriteError:
     106c. for a write operation on the underlying socket.  Note that
     attempts to 'write' to an SSL socket may require 'reading' from the
     underlying socket first, and attempts to 'read' from the SSL socket
     may require a prior 'write' to the underlying socket.

     Cambiato nella versione 3.5: In earlier Python versions, the
     ‘SSLSocket.send()’ method returned zero instead of raising *note
     SSLWantWriteError: 106c. or *note SSLWantReadError: 106b.

   - Calling *note select(): fa2. tells you that the OS-level socket can
     be read from (or written to), but it does not imply that there is
     sufficient data at the upper SSL layer.  For example, only part of
     an SSL frame might have arrived.  Therefore, you must be ready to
     handle ‘SSLSocket.recv()’ and ‘SSLSocket.send()’ failures, and
     retry after another call to *note select(): fa2.

   - Conversely, since the SSL layer has its own framing, a SSL socket
     may still have data available for reading without *note select():
     fa2. being aware of it.  Therefore, you should first call
     ‘SSLSocket.recv()’ to drain any potentially available data, and
     then only block on a *note select(): fa2. call if still necessary.

     (of course, similar provisions apply when using other primitives
     such as *note poll(): 308e, or those in the *note selectors: c7.
     module)

   - The SSL handshake itself will be non-blocking: the *note
     SSLSocket.do_handshake(): 106f. method has to be retried until it
     returns successfully.  Here is a synopsis using *note select():
     fa2. to wait for the socket’s readiness:

          while True:
              try:
                  sock.do_handshake()
                  break
              except ssl.SSLWantReadError:
                  select.select([sock], [], [])
              except ssl.SSLWantWriteError:
                  select.select([], [sock], [])

Vedi anche
..........

The *note asyncio: b. module supports *note non-blocking SSL sockets:
399c. and provides a higher level *note Streams API: 379f.  It polls for
events using the *note selectors: c7. module and handles *note
SSLWantWriteError: 106c, *note SSLWantReadError: 106b. and *note
BlockingIOError: 235. exceptions.  It runs the SSL handshake
asynchronously as well.


File: python.info,  Node: Memory BIO Support<2>,  Next: SSL session,  Prev: Notes on non-blocking sockets,  Up: ssl — TLS/SSL wrapper for socket objects

5.19.3.20 Memory BIO Support
............................

Added in version 3.5.

Ever since the SSL module was introduced in Python 2.6, the *note
SSLSocket: ae9. class has provided two related but distinct areas of
functionality:

   - SSL protocol handling

   - Network IO

The network IO API is identical to that provided by *note socket.socket:
fa3, from which *note SSLSocket: ae9. also inherits.  This allows an SSL
socket to be used as a drop-in replacement for a regular socket, making
it very easy to add SSL support to an existing application.

Combining SSL protocol handling and network IO usually works well, but
there are some cases where it doesn’t.  An example is async IO
frameworks that want to use a different IO multiplexing model than the
«select/poll on a file descriptor» (readiness based) model that is
assumed by *note socket.socket: fa3. and by the internal OpenSSL socket
IO routines.  This is mostly relevant for platforms like Windows where
this model is not efficient.  For this purpose, a reduced scope variant
of *note SSLSocket: ae9. called *note SSLObject: d7c. is provided.

 -- Classe: ssl.SSLObject

     A reduced-scope variant of *note SSLSocket: ae9. representing an
     SSL protocol instance that does not contain any network IO methods.
     This class is typically used by framework authors that want to
     implement asynchronous IO for SSL through memory buffers.

     This class implements an interface on top of a low-level SSL object
     as implemented by OpenSSL. This object captures the state of an SSL
     connection but does not provide any network IO itself.  IO needs to
     be performed through separate «BIO» objects which are OpenSSL’s IO
     abstraction layer.

     This class has no public constructor.  An *note SSLObject: d7c.
     instance must be created using the *note wrap_bio(): d7d. method.
     This method will create the *note SSLObject: d7c. instance and bind
     it to a pair of BIOs.  The 'incoming' BIO is used to pass data from
     Python to the SSL protocol instance, while the 'outgoing' BIO is
     used to pass data the other way around.

     The following methods are available:

        - *note context: 39d3.

        - *note server_side: 39d5.

        - *note server_hostname: d7a.

        - *note session: 1925.

        - *note session_reused: 39d6.

        - *note read(): 1070.

        - *note write(): 1071.

        - *note getpeercert(): 11ba.

        - *note get_verified_chain(): 1944.

        - *note get_unverified_chain(): 1945.

        - *note selected_alpn_protocol(): 1067.

        - *note selected_npn_protocol(): a76.

        - *note cipher(): 38c0.

        - *note shared_ciphers(): 106e.

        - *note compression(): 134d.

        - *note pending(): 39d4.

        - *note do_handshake(): 106f.

        - *note verify_client_post_handshake(): c29.

        - *note unwrap(): 39d2.

        - *note get_channel_binding(): 134c.

        - *note version(): 106a.

     When compared to *note SSLSocket: ae9, this object lacks the
     following features:

        - Any form of network IO; ‘recv()’ and ‘send()’ read and write
          only to the underlying *note MemoryBIO: 1064. buffers.

        - There is no 'do_handshake_on_connect' machinery.  You must
          always manually call *note do_handshake(): 106f. to start the
          handshake.

        - There is no handling of 'suppress_ragged_eofs'.  All
          end-of-file conditions that are in violation of the protocol
          are reported via the *note SSLEOFError: 1aa0. exception.

        - The method *note unwrap(): 39d2. call does not return
          anything, unlike for an SSL socket where it returns the
          underlying socket.

        - The 'server_name_callback' callback passed to *note
          SSLContext.set_servername_callback(): 11b9. will get an *note
          SSLObject: d7c. instance instead of a *note SSLSocket: ae9.
          instance as its first parameter.

     Some notes related to the use of *note SSLObject: d7c.:

        - All IO on an *note SSLObject: d7c. is *note non-blocking:
          399c.  This means that for example *note read(): 1070. will
          raise an *note SSLWantReadError: 106b. if it needs more data
          than the incoming BIO has available.

     Cambiato nella versione 3.7: *note SSLObject: d7c. instances must
     be created with *note wrap_bio(): d7d.  In earlier versions, it was
     possible to create instances directly.  This was never documented
     or officially supported.

An SSLObject communicates with the outside world using memory buffers.
The class *note MemoryBIO: 1064. provides a memory buffer that can be
used for this purpose.  It wraps an OpenSSL memory BIO (Basic IO)
object:

 -- Classe: ssl.MemoryBIO

     A memory buffer that can be used to pass data between Python and an
     SSL protocol instance.

      -- Attributo: pending

          Return the number of bytes currently in the memory buffer.

      -- Attributo: eof

          A boolean indicating whether the memory BIO is current at the
          end-of-file position.

      -- Metodo: read (n=-1, /)

          Read up to 'n' bytes from the memory buffer.  If 'n' is not
          specified or negative, all bytes are returned.

      -- Metodo: write (buf, /)

          Write the bytes from 'buf' to the memory BIO. The 'buf'
          argument must be an object supporting the buffer protocol.

          The return value is the number of bytes written, which is
          always equal to the length of 'buf'.

      -- Metodo: write_eof ()

          Write an EOF marker to the memory BIO. After this method has
          been called, it is illegal to call *note write(): 39f0.  The
          attribute *note eof: 39ee. will become true after all data
          currently in the buffer has been read.


File: python.info,  Node: SSL session,  Next: Security considerations<2>,  Prev: Memory BIO Support<2>,  Up: ssl — TLS/SSL wrapper for socket objects

5.19.3.21 SSL session
.....................

Added in version 3.6.

 -- Classe: ssl.SSLSession

     Session object used by *note session: 1925.

      -- Attributo: id

      -- Attributo: time

      -- Attributo: timeout

      -- Attributo: ticket_lifetime_hint

      -- Attributo: has_ticket


File: python.info,  Node: Security considerations<2>,  Next: TLS 1 3,  Prev: SSL session,  Up: ssl — TLS/SSL wrapper for socket objects

5.19.3.22 Security considerations
.................................

* Menu:

* Best defaults::
* Manual settings::
* Multi-processing::


File: python.info,  Node: Best defaults,  Next: Manual settings,  Up: Security considerations<2>

5.19.3.23 Best defaults
.......................

For 'client use', if you don’t have any special requirements for your
security policy, it is highly recommended that you use the *note
create_default_context(): 480. function to create your SSL context.  It
will load the system’s trusted CA certificates, enable certificate
validation and hostname checking, and try to choose reasonably secure
protocol and cipher settings.

For example, here is how you would use the *note smtplib.SMTP: b29.
class to create a trusted, secure connection to a SMTP server:

     >>> import ssl, smtplib
     >>> smtp = smtplib.SMTP("mail.python.org", port=587)
     >>> context = ssl.create_default_context()
     >>> smtp.starttls(context=context)
     (220, b'2.0.0 Ready to start TLS')

If a client certificate is needed for the connection, it can be added
with *note SSLContext.load_cert_chain(): 598.

By contrast, if you create the SSL context by calling the *note
SSLContext: 357. constructor yourself, it will not have certificate
validation nor hostname checking enabled by default.  If you do so,
please read the paragraphs below to achieve a good security level.


File: python.info,  Node: Manual settings,  Next: Multi-processing,  Prev: Best defaults,  Up: Security considerations<2>

5.19.3.24 Manual settings
.........................

* Menu:

* Verifying certificates::
* Protocol versions::
* Cipher selection::


File: python.info,  Node: Verifying certificates,  Next: Protocol versions,  Up: Manual settings

5.19.3.25 Verifying certificates
................................

When calling the *note SSLContext: 357. constructor directly, *note
CERT_NONE: 39a8. is the default.  Since it does not authenticate the
other peer, it can be insecure, especially in client mode where most of
the time you would like to ensure the authenticity of the server you’re
talking to.  Therefore, when in client mode, it is highly recommended to
use *note CERT_REQUIRED: 3997.  However, it is in itself not sufficient;
you also have to check that the server certificate, which can be
obtained by calling *note SSLSocket.getpeercert(): 11ba, matches the
desired service.  For many protocols and applications, the service can
be identified by the hostname.  This common check is automatically
performed when *note SSLContext.check_hostname: 39aa. is enabled.

Cambiato nella versione 3.7: Hostname matchings is now performed by
OpenSSL. Python no longer uses ‘match_hostname()’.

In server mode, if you want to authenticate your clients using the SSL
layer (rather than using a higher-level authentication mechanism),
you’ll also have to specify *note CERT_REQUIRED: 3997. and similarly
check the client certificate.


File: python.info,  Node: Protocol versions,  Next: Cipher selection,  Prev: Verifying certificates,  Up: Manual settings

5.19.3.26 Protocol versions
...........................

SSL versions 2 and 3 are considered insecure and are therefore dangerous
to use.  If you want maximum compatibility between clients and servers,
it is recommended to use *note PROTOCOL_TLS_CLIENT: a74. or *note
PROTOCOL_TLS_SERVER: a75. as the protocol version.  SSLv2 and SSLv3 are
disabled by default.

     >>> client_context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
     >>> client_context.minimum_version = ssl.TLSVersion.TLSv1_3
     >>> client_context.maximum_version = ssl.TLSVersion.TLSv1_3

The SSL context created above will only allow TLSv1.3 and later (if
supported by your system) connections to a server.  *note
PROTOCOL_TLS_CLIENT: a74. implies certificate validation and hostname
checks by default.  You have to load certificates into the context.


File: python.info,  Node: Cipher selection,  Prev: Protocol versions,  Up: Manual settings

5.19.3.27 Cipher selection
..........................

If you have advanced security requirements, fine-tuning of the ciphers
enabled when negotiating a SSL session is possible through the *note
SSLContext.set_ciphers(): 39d9. method.  Starting from Python 3.2.3, the
ssl module disables certain weak ciphers by default, but you may want to
further restrict the cipher choice.  Be sure to read OpenSSL’s
documentation about the cipher list format(1).  If you want to check
which ciphers are enabled by a given cipher list, use *note
SSLContext.get_ciphers(): edc. or the ‘openssl ciphers’ command on your
system.

   ---------- Footnotes ----------

   (1) https://docs.openssl.org/1.1.1/man1/ciphers/#cipher-list-format


File: python.info,  Node: Multi-processing,  Prev: Manual settings,  Up: Security considerations<2>

5.19.3.28 Multi-processing
..........................

If using this module as part of a multi-processed application (using,
for example the *note multiprocessing: 98. or *note concurrent.futures:
24. modules), be aware that OpenSSL’s internal random number generator
does not properly handle forked processes.  Applications must change the
PRNG state of the parent process if they use any SSL feature with *note
os.fork(): 4b6.  Any successful call of *note RAND_add(): 39a2. or *note
RAND_bytes(): 748. is sufficient.


File: python.info,  Node: TLS 1 3,  Prev: Security considerations<2>,  Up: ssl — TLS/SSL wrapper for socket objects

5.19.3.29 TLS 1.3
.................

Added in version 3.7.

The TLS 1.3 protocol behaves slightly differently than previous version
of TLS/SSL. Some new TLS 1.3 features are not yet available.

   - TLS 1.3 uses a disjunct set of cipher suites.  All AES-GCM and
     ChaCha20 cipher suites are enabled by default.  The method *note
     SSLContext.set_ciphers(): 39d9. cannot enable or disable any TLS
     1.3 ciphers yet, but *note SSLContext.get_ciphers(): edc. returns
     them.

   - Session tickets are no longer sent as part of the initial handshake
     and are handled differently.  *note SSLSocket.session: 1925. and
     *note SSLSession: edb. are not compatible with TLS 1.3.

   - Client-side certificates are also no longer verified during the
     initial handshake.  A server can request a certificate at any time.
     Clients process certificate requests while they send or receive
     application data from the server.

   - TLS 1.3 features like early data, deferred TLS client cert request,
     signature algorithm configuration, and rekeying are not supported
     yet.

Vedi anche
..........

Class *note socket.socket: fa3.

     Documentation of underlying *note socket: d1. class

SSL/TLS Strong Encryption: An Introduction(1)

     Intro from the Apache HTTP Server documentation

RFC 1422: Privacy Enhancement for Internet Electronic Mail: Part II: Certificate-Based Key Management(2)

     Steve Kent

RFC 4086: Randomness Requirements for Security(3)

     Donald E. Eastlake, Jeffrey I. Schiller, Steve Crocker

RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile(4)

     David Cooper et al.

RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2(5)

     Tim Dierks and Eric Rescorla.

RFC 6066: Transport Layer Security (TLS) Extensions(6)

     Donald E. Eastlake

IANA TLS: Transport Layer Security (TLS) Parameters(7)

     IANA

RFC 7525: Recommendations for Secure Use of Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS)(8)

     IETF

Mozilla's Server Side TLS recommendations(9)

     Mozilla

   ---------- Footnotes ----------

   (1) https://httpd.apache.org/docs/trunk/en/ssl/ssl_intro.html

   (2) https://datatracker.ietf.org/doc/html/rfc1422.html

   (3) https://datatracker.ietf.org/doc/html/rfc4086.html

   (4) https://datatracker.ietf.org/doc/html/rfc5280.html

   (5) https://datatracker.ietf.org/doc/html/rfc5246.html

   (6) https://datatracker.ietf.org/doc/html/rfc6066.html

   (7) 
https://www.iana.org/assignments/tls-parameters/tls-parameters.xml

   (8) https://datatracker.ietf.org/doc/html/rfc7525.html

   (9) https://wiki.mozilla.org/Security/Server_Side_TLS


File: python.info,  Node: select — Waiting for I/O completion,  Next: selectors — High-level I/O multiplexing,  Prev: ssl — TLS/SSL wrapper for socket objects,  Up: Networking and Interprocess Communication

5.19.4 ‘select’ — Waiting for I/O completion
--------------------------------------------

__________________________________________________________________

This module provides access to the ‘select()’ and ‘poll()’ functions
available in most operating systems, ‘devpoll()’ available on Solaris
and derivatives, ‘epoll()’ available on Linux 2.5+ and ‘kqueue()’
available on most BSD. Note that on Windows, it only works for sockets;
on other operating systems, it also works for other file types (in
particular, on Unix, it works on pipes).  It cannot be used on regular
files to determine whether a file has grown since it was last read.

     Nota: The *note selectors: c7. module allows high-level and
     efficient I/O multiplexing, built upon the *note select: c6. module
     primitives.  Users are encouraged to use the *note selectors: c7.
     module instead, unless they want precise control over the OS-level
     primitives used.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

The module defines the following:

 -- Eccezione: select.error

     A deprecated alias of *note OSError: 2c0.

     Cambiato nella versione 3.3: Following PEP 3151(1), this class was
     made an alias of *note OSError: 2c0.

 -- Funzione: select.devpoll ()

     (Only supported on Solaris and derivatives.)  Returns a ‘/dev/poll’
     polling object; see section *note /dev/poll Polling Objects: 3a03.
     below for the methods supported by devpoll objects.

     ‘devpoll()’ objects are linked to the number of file descriptors
     allowed at the time of instantiation.  If your program reduces this
     value, ‘devpoll()’ will fail.  If your program increases this
     value, ‘devpoll()’ may return an incomplete list of active file
     descriptors.

     The new file descriptor is *note non-inheritable: 10fe.

     Added in version 3.3.

     Cambiato nella versione 3.4: The new file descriptor is now
     non-inheritable.

 -- Funzione: select.epoll (sizehint=-1, flags=0)

     (Only supported on Linux 2.5.44 and newer.)  Return an edge polling
     object, which can be used as Edge or Level Triggered interface for
     I/O events.

     'sizehint' informs epoll about the expected number of events to be
     registered.  It must be positive, or ‘-1’ to use the default.  It
     is only used on older systems where ‘epoll_create1()’ is not
     available; otherwise it has no effect (though its value is still
     checked).

     'flags' is deprecated and completely ignored.  However, when
     supplied, its value must be ‘0’ or ‘select.EPOLL_CLOEXEC’,
     otherwise ‘OSError’ is raised.

     See the *note Edge and Level Trigger Polling (epoll) Objects: 3a04.
     section below for the methods supported by epolling objects.

     ‘epoll’ objects support the context management protocol: when used
     in a *note with: 186. statement, the new file descriptor is
     automatically closed at the end of the block.

     The new file descriptor is *note non-inheritable: 10fe.

     Cambiato nella versione 3.3: Added the 'flags' parameter.

     Cambiato nella versione 3.4: Support for the *note with: 186.
     statement was added.  The new file descriptor is now
     non-inheritable.

     Deprecato dalla versione 3.4: The 'flags' parameter.
     ‘select.EPOLL_CLOEXEC’ is used by default now.  Use *note
     os.set_inheritable(): 1100. to make the file descriptor
     inheritable.

 -- Funzione: select.poll ()

     (Not supported by all operating systems.)  Returns a polling
     object, which supports registering and unregistering file
     descriptors, and then polling them for I/O events; see section
     *note Polling Objects: 3a05. below for the methods supported by
     polling objects.

 -- Funzione: select.kqueue ()

     (Only supported on BSD.) Returns a kernel queue object; see section
     *note Kqueue Objects: 3a06. below for the methods supported by
     kqueue objects.

     The new file descriptor is *note non-inheritable: 10fe.

     Cambiato nella versione 3.4: The new file descriptor is now
     non-inheritable.

 -- Funzione: select.kevent (ident, filter=KQ_FILTER_READ,
          flags=KQ_EV_ADD, fflags=0, data=0, udata=0)

     (Only supported on BSD.) Returns a kernel event object; see section
     *note Kevent Objects: 3a08. below for the methods supported by
     kevent objects.

 -- Funzione: select.select (rlist, wlist, xlist, timeout=None)

     This is a straightforward interface to the Unix ‘select()’ system
     call.  The first three arguments are iterables of “waitable
     objects”: either integers representing file descriptors or objects
     with a parameterless method named *note fileno(): 1795. returning
     such an integer:

        * 'rlist': wait until ready for reading

        * 'wlist': wait until ready for writing

        * 'xlist': wait for an «exceptional condition» (see the manual
          page for what your system considers such a condition)

     Empty iterables are allowed, but acceptance of three empty
     iterables is platform-dependent.  (It is known to work on Unix but
     not on Windows.)  The optional 'timeout' argument specifies a
     time-out as a floating-point number in seconds.  When the 'timeout'
     argument is omitted or ‘None’, the function blocks until at least
     one file descriptor is ready.  A time-out value of zero specifies a
     poll and never blocks.

     The return value is a triple of lists of objects that are ready:
     subsets of the first three arguments.  When the time-out is reached
     without a file descriptor becoming ready, three empty lists are
     returned.

     Among the acceptable object types in the iterables are Python *note
     file objects: 13cb. (e.g.  ‘sys.stdin’, or objects returned by
     *note open(): 316. or *note os.popen(): 31a.), socket objects
     returned by *note socket.socket(): fa3.  You may also define a
     'wrapper' class yourself, as long as it has an appropriate *note
     fileno(): 1795. method (that really returns a file descriptor, not
     just a random integer).

          Nota: 
          File objects on Windows are not acceptable, but sockets are.
          On Windows, the underlying ‘select()’ function is provided by
          the WinSock library, and does not handle file descriptors that
          don’t originate from WinSock.

     Cambiato nella versione 3.5: The function is now retried with a
     recomputed timeout when interrupted by a signal, except if the
     signal handler raises an exception (see PEP 475(2) for the
     rationale), instead of raising *note InterruptedError: f8a.

 -- Dati: select.PIPE_BUF

     The minimum number of bytes which can be written without blocking
     to a pipe when the pipe has been reported as ready for writing by
     *note select(): fa2, ‘poll()’ or another interface in this module.
     This doesn’t apply to other kind of file-like objects such as
     sockets.

     This value is guaranteed by POSIX to be at least 512.

     *note Availability: 2128.: Unix

     Added in version 3.2.

* Menu:

* /dev/poll Polling Objects::
* Edge and Level Trigger Polling (epoll) Objects: Edge and Level Trigger Polling epoll Objects.
* Polling Objects::
* Kqueue Objects::
* Kevent Objects::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3151/

   (2) https://peps.python.org/pep-0475/


File: python.info,  Node: /dev/poll Polling Objects,  Next: Edge and Level Trigger Polling epoll Objects,  Up: select — Waiting for I/O completion

5.19.4.1 ‘/dev/poll’ Polling Objects
....................................

Solaris and derivatives have ‘/dev/poll’.  While ‘select()’ is
'O'('highest file descriptor') and ‘poll()’ is 'O'('number of file
descriptors'), ‘/dev/poll’ is 'O'('active file descriptors').

‘/dev/poll’ behaviour is very close to the standard ‘poll()’ object.

 -- Metodo: devpoll.close ()

     Close the file descriptor of the polling object.

     Added in version 3.4.

 -- Attributo: devpoll.closed

     ‘True’ if the polling object is closed.

     Added in version 3.4.

 -- Metodo: devpoll.fileno ()

     Return the file descriptor number of the polling object.

     Added in version 3.4.

 -- Metodo: devpoll.register (fd[, eventmask])

     Register a file descriptor with the polling object.  Future calls
     to the *note poll(): 308e. method will then check whether the file
     descriptor has any pending I/O events.  'fd' can be either an
     integer, or an object with a *note fileno(): 1795. method that
     returns an integer.  File objects implement ‘fileno()’, so they can
     also be used as the argument.

     'eventmask' is an optional bitmask describing the type of events
     you want to check for.  The constants are the same that with
     ‘poll()’ object.  The default value is a combination of the
     constants ‘POLLIN’, ‘POLLPRI’, and ‘POLLOUT’.

          Avvertimento: Registering a file descriptor that’s already
          registered is not an error, but the result is undefined.  The
          appropriate action is to unregister or modify it first.  This
          is an important difference compared with ‘poll()’.

 -- Metodo: devpoll.modify (fd[, eventmask])

     This method does an *note unregister(): 3a0c. followed by a *note
     register(): 3a0a.  It is (a bit) more efficient that doing the same
     explicitly.

 -- Metodo: devpoll.unregister (fd)

     Remove a file descriptor being tracked by a polling object.  Just
     like the *note register(): 3a0a. method, 'fd' can be an integer or
     an object with a *note fileno(): 1795. method that returns an
     integer.

     Attempting to remove a file descriptor that was never registered is
     safely ignored.

 -- Metodo: devpoll.poll ([timeout])

     Polls the set of registered file descriptors, and returns a
     possibly empty list containing ‘(fd, event)’ 2-tuples for the
     descriptors that have events or errors to report.  'fd' is the file
     descriptor, and 'event' is a bitmask with bits set for the reported
     events for that descriptor — ‘POLLIN’ for waiting input, ‘POLLOUT’
     to indicate that the descriptor can be written to, and so forth.
     An empty list indicates that the call timed out and no file
     descriptors had any events to report.  If 'timeout' is given, it
     specifies the length of time in milliseconds which the system will
     wait for events before returning.  If 'timeout' is omitted, -1, or
     *note None: 886, the call will block until there is an event for
     this poll object.

     Cambiato nella versione 3.5: The function is now retried with a
     recomputed timeout when interrupted by a signal, except if the
     signal handler raises an exception (see PEP 475(1) for the
     rationale), instead of raising *note InterruptedError: f8a.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0475/


File: python.info,  Node: Edge and Level Trigger Polling epoll Objects,  Next: Polling Objects,  Prev: /dev/poll Polling Objects,  Up: select — Waiting for I/O completion

5.19.4.2 Edge and Level Trigger Polling (epoll) Objects
.......................................................

     ‘https://linux.die.net/man/4/epoll’

     'eventmask'

     Constant                      Meaning
                                   
     ----------------------------------------------------------------------------------
                                   
     ‘EPOLLIN’                     Available for read
                                   
                                   
     ‘EPOLLOUT’                    Available for write
                                   
                                   
     ‘EPOLLPRI’                    Urgent data for read
                                   
                                   
     ‘EPOLLERR’                    Error condition happened on the assoc.  fd
                                   
                                   
     ‘EPOLLHUP’                    Hang up happened on the assoc.  fd
                                   
                                   
     ‘EPOLLET’                     Set Edge Trigger behavior, the default is Level
                                   Trigger behavior
                                   
                                   
     ‘EPOLLONESHOT’                Set one-shot behavior.  After one event is pulled
                                   out, the fd is internally disabled
                                   
                                   
     ‘EPOLLEXCLUSIVE’              Wake only one epoll object when the associated fd
                                   has an event.  The default (if this flag is not
                                   set) is to wake all epoll objects polling on a
                                   fd.
                                   
                                   
     ‘EPOLLRDHUP’                  Stream socket peer closed connection or shut down
                                   writing half of connection.
                                   
                                   
     ‘EPOLLRDNORM’                 Equivalent to ‘EPOLLIN’
                                   
                                   
     ‘EPOLLRDBAND’                 Priority data band can be read.
                                   
                                   
     ‘EPOLLWRNORM’                 Equivalent to ‘EPOLLOUT’
                                   
                                   
     ‘EPOLLWRBAND’                 Priority data may be written.
                                   
                                   
     ‘EPOLLMSG’                    Ignored.
                                   
                                   
     ‘EPOLLWAKEUP’                 Prevents sleep during event waiting.
                                   

     Added in version 3.6: ‘EPOLLEXCLUSIVE’ was added.  It’s only
     supported by Linux Kernel 4.5 or later.

     Added in version 3.14: ‘EPOLLWAKEUP’ was added.  It’s only
     supported by Linux Kernel 3.5 or later.

 -- Metodo: epoll.close ()

     Close the control file descriptor of the epoll object.

 -- Attributo: epoll.closed

     ‘True’ if the epoll object is closed.

 -- Metodo: epoll.fileno ()

     Return the file descriptor number of the control fd.

 -- Metodo: epoll.fromfd (fd)

     Create an epoll object from a given file descriptor.

 -- Metodo: epoll.register (fd[, eventmask])

     Register a fd descriptor with the epoll object.

 -- Metodo: epoll.modify (fd, eventmask)

     Modify a registered file descriptor.

 -- Metodo: epoll.unregister (fd)

     Remove a registered file descriptor from the epoll object.

     Cambiato nella versione 3.9: The method no longer ignores the *note
     EBADF: b56. error.

 -- Metodo: epoll.poll (timeout=None, maxevents=-1)

     Wait for events.  timeout in seconds (float)

     Cambiato nella versione 3.5: The function is now retried with a
     recomputed timeout when interrupted by a signal, except if the
     signal handler raises an exception (see PEP 475(1) for the
     rationale), instead of raising *note InterruptedError: f8a.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0475/


File: python.info,  Node: Polling Objects,  Next: Kqueue Objects,  Prev: Edge and Level Trigger Polling epoll Objects,  Up: select — Waiting for I/O completion

5.19.4.3 Polling Objects
........................

The ‘poll()’ system call, supported on most Unix systems, provides
better scalability for network servers that service many, many clients
at the same time.  ‘poll()’ scales better because the system call only
requires listing the file descriptors of interest, while ‘select()’
builds a bitmap, turns on bits for the fds of interest, and then
afterward the whole bitmap has to be linearly scanned again.  ‘select()’
is 'O'('highest file descriptor'), while ‘poll()’ is 'O'('number of file
descriptors').

 -- Metodo: poll.register (fd[, eventmask])

     Register a file descriptor with the polling object.  Future calls
     to the *note poll(): 308e. method will then check whether the file
     descriptor has any pending I/O events.  'fd' can be either an
     integer, or an object with a *note fileno(): 1795. method that
     returns an integer.  File objects implement ‘fileno()’, so they can
     also be used as the argument.

     'eventmask' is an optional bitmask describing the type of events
     you want to check for, and can be a combination of the constants
     ‘POLLIN’, ‘POLLPRI’, and ‘POLLOUT’, described in the table below.
     If not specified, the default value used will check for all 3 types
     of events.

     Constant                Meaning
                             
     -----------------------------------------------------------------------
                             
     ‘POLLIN’                There is data to read
                             
                             
     ‘POLLPRI’               There is urgent data to read
                             
                             
     ‘POLLOUT’               Ready for output: writing will not block
                             
                             
     ‘POLLERR’               Error condition of some sort
                             
                             
     ‘POLLHUP’               Hung up
                             
                             
     ‘POLLRDHUP’             Stream socket peer closed connection, or
                             shut down writing half of connection
                             
                             
     ‘POLLNVAL’              Invalid request: descriptor not open
                             

     Registering a file descriptor that’s already registered is not an
     error, and has the same effect as registering the descriptor
     exactly once.

 -- Metodo: poll.modify (fd, eventmask)

     Modifies an already registered fd.  This has the same effect as
     ‘register(fd, eventmask)’.  Attempting to modify a file descriptor
     that was never registered causes an *note OSError: 2c0. exception
     with errno ‘ENOENT’ to be raised.

 -- Metodo: poll.unregister (fd)

     Remove a file descriptor being tracked by a polling object.  Just
     like the *note register(): 3a14. method, 'fd' can be an integer or
     an object with a *note fileno(): 1795. method that returns an
     integer.

     Attempting to remove a file descriptor that was never registered
     causes a *note KeyError: 5e7. exception to be raised.

 -- Metodo: poll.poll ([timeout])

     Polls the set of registered file descriptors, and returns a
     possibly empty list containing ‘(fd, event)’ 2-tuples for the
     descriptors that have events or errors to report.  'fd' is the file
     descriptor, and 'event' is a bitmask with bits set for the reported
     events for that descriptor — ‘POLLIN’ for waiting input, ‘POLLOUT’
     to indicate that the descriptor can be written to, and so forth.
     An empty list indicates that the call timed out and no file
     descriptors had any events to report.  If 'timeout' is given, it
     specifies the length of time in milliseconds which the system will
     wait for events before returning.  If 'timeout' is omitted,
     negative, or *note None: 886, the call will block until there is an
     event for this poll object.

     Cambiato nella versione 3.5: The function is now retried with a
     recomputed timeout when interrupted by a signal, except if the
     signal handler raises an exception (see PEP 475(1) for the
     rationale), instead of raising *note InterruptedError: f8a.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0475/


File: python.info,  Node: Kqueue Objects,  Next: Kevent Objects,  Prev: Polling Objects,  Up: select — Waiting for I/O completion

5.19.4.4 Kqueue Objects
.......................

 -- Metodo: kqueue.close ()

     Close the control file descriptor of the kqueue object.

 -- Attributo: kqueue.closed

     ‘True’ if the kqueue object is closed.

 -- Metodo: kqueue.fileno ()

     Return the file descriptor number of the control fd.

 -- Metodo: kqueue.fromfd (fd)

     Create a kqueue object from a given file descriptor.

 -- Metodo: kqueue.control (changelist, max_events[, timeout]) ->
          eventlist

     Low level interface to kevent

        - changelist must be an iterable of kevent objects or ‘None’

        - max_events must be 0 or a positive integer

        - timeout in seconds (floats possible); the default is ‘None’,
          to wait forever

     Cambiato nella versione 3.5: The function is now retried with a
     recomputed timeout when interrupted by a signal, except if the
     signal handler raises an exception (see PEP 475(1) for the
     rationale), instead of raising *note InterruptedError: f8a.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0475/


File: python.info,  Node: Kevent Objects,  Prev: Kqueue Objects,  Up: select — Waiting for I/O completion

5.19.4.5 Kevent Objects
.......................

‘https://man.freebsd.org/cgi/man.cgi?query=kqueue&sektion=2’

 -- Attributo: kevent.ident

     Value used to identify the event.  The interpretation depends on
     the filter but it’s usually the file descriptor.  In the
     constructor ident can either be an int or an object with a *note
     fileno(): 1795. method.  kevent stores the integer internally.

 -- Attributo: kevent.filter

     Name of the kernel filter.

     Constant                        Meaning
                                     
     ----------------------------------------------------------------------------------
                                     
     ‘KQ_FILTER_READ’                Takes a descriptor and returns whenever there
                                     is data available to read
                                     
                                     
     ‘KQ_FILTER_WRITE’               Takes a descriptor and returns whenever there
                                     is data available to write
                                     
                                     
     ‘KQ_FILTER_AIO’                 AIO requests
                                     
                                     
     ‘KQ_FILTER_VNODE’               Returns when one or more of the requested
                                     events watched in 'fflag' occurs
                                     
                                     
     ‘KQ_FILTER_PROC’                Watch for events on a process id
                                     
                                     
     ‘KQ_FILTER_NETDEV’              Watch for events on a network device [not
                                     available on macOS]
                                     
                                     
     ‘KQ_FILTER_SIGNAL’              Returns whenever the watched signal is
                                     delivered to the process
                                     
                                     
     ‘KQ_FILTER_TIMER’               Establishes an arbitrary timer
                                     

 -- Attributo: kevent.flags

     Filter action.

     Constant                        Meaning
                                     
     ----------------------------------------------------------------------------------
                                     
     ‘KQ_EV_ADD’                     Adds or modifies an event
                                     
                                     
     ‘KQ_EV_DELETE’                  Removes an event from the queue
                                     
                                     
     ‘KQ_EV_ENABLE’                  Permitscontrol() to returns the event
                                     
                                     
     ‘KQ_EV_DISABLE’                 Disablesevent
                                     
                                     
     ‘KQ_EV_ONESHOT’                 Removes event after first occurrence
                                     
                                     
     ‘KQ_EV_CLEAR’                   Reset the state after an event is retrieved
                                     
                                     
     ‘KQ_EV_SYSFLAGS’                internal event
                                     
                                     
     ‘KQ_EV_FLAG1’                   internal event
                                     
                                     
     ‘KQ_EV_EOF’                     Filter specific EOF condition
                                     
                                     
     ‘KQ_EV_ERROR’                   See return values
                                     

 -- Attributo: kevent.fflags

     Filter specific flags.

     ‘KQ_FILTER_READ’ and ‘KQ_FILTER_WRITE’ filter flags:

     Constant                         Meaning
                                      
     ----------------------------------------------------------------------------------
                                      
     ‘KQ_NOTE_LOWAT’                  low water mark of a socket buffer
                                      

     ‘KQ_FILTER_VNODE’ filter flags:

     Constant                         Meaning
                                      
     ----------------------------------------------------------------------------------
                                      
     ‘KQ_NOTE_DELETE’                 'unlink()' was called
                                      
                                      
     ‘KQ_NOTE_WRITE’                  a write occurred
                                      
                                      
     ‘KQ_NOTE_EXTEND’                 the file was extended
                                      
                                      
     ‘KQ_NOTE_ATTRIB’                 an attribute was changed
                                      
                                      
     ‘KQ_NOTE_LINK’                   the link count has changed
                                      
                                      
     ‘KQ_NOTE_RENAME’                 the file was renamed
                                      
                                      
     ‘KQ_NOTE_REVOKE’                 access to the file was revoked
                                      

     ‘KQ_FILTER_PROC’ filter flags:

     Constant                         Meaning
                                      
     ----------------------------------------------------------------------------------
                                      
     ‘KQ_NOTE_EXIT’                   the process has exited
                                      
                                      
     ‘KQ_NOTE_FORK’                   the process has called 'fork()'
                                      
                                      
     ‘KQ_NOTE_EXEC’                   the process has executed a new process
                                      
                                      
     ‘KQ_NOTE_PCTRLMASK’              internal filter flag
                                      
                                      
     ‘KQ_NOTE_PDATAMASK’              internal filter flag
                                      
                                      
     ‘KQ_NOTE_TRACK’                  follow a process across 'fork()'
                                      
                                      
     ‘KQ_NOTE_CHILD’                  returned on the child process for 'NOTE_TRACK'
                                      
                                      
     ‘KQ_NOTE_TRACKERR’               unable to attach to a child
                                      

     ‘KQ_FILTER_NETDEV’ filter flags (not available on macOS):

     Constant                         Meaning
                                      
     ----------------------------------------------------------------------------------
                                      
     ‘KQ_NOTE_LINKUP’                 link is up
                                      
                                      
     ‘KQ_NOTE_LINKDOWN’               link is down
                                      
                                      
     ‘KQ_NOTE_LINKINV’                link state is invalid
                                      

 -- Attributo: kevent.data

     Filter specific data.

 -- Attributo: kevent.udata

     User defined value.


File: python.info,  Node: selectors — High-level I/O multiplexing,  Next: signal — Set handlers for asynchronous events,  Prev: select — Waiting for I/O completion,  Up: Networking and Interprocess Communication

5.19.5 ‘selectors’ — High-level I/O multiplexing
------------------------------------------------

Added in version 3.4.

'Source code:' Lib/selectors.py(1)

__________________________________________________________________

* Menu:

* Introduction: Introduction<10>.
* Classes: Classes<3>.
* Examples: Examples<22>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/selectors.py


File: python.info,  Node: Introduction<10>,  Next: Classes<3>,  Up: selectors — High-level I/O multiplexing

5.19.5.1 Introduction
.....................

This module allows high-level and efficient I/O multiplexing, built upon
the *note select: c6. module primitives.  Users are encouraged to use
this module instead, unless they want precise control over the OS-level
primitives used.

It defines a *note BaseSelector: 3a27. abstract base class, along with
several concrete implementations (*note KqueueSelector: 38fd, *note
EpollSelector: dd2.…), that can be used to wait for I/O readiness
notification on multiple file objects.  In the following, «file object»
refers to any object with a *note fileno(): 1795. method, or a raw file
descriptor.  See *note file object: 13cb.

*note DefaultSelector: 3a28. is an alias to the most efficient
implementation available on the current platform: this should be the
default choice for most users.

     Nota: The type of file objects supported depends on the platform:
     on Windows, sockets are supported, but not pipes, whereas on Unix,
     both are supported (some other types may be supported as well, such
     as fifos or special file devices).

Vedi anche
..........

*note select: c6.

     Low-level I/O multiplexing module.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.


File: python.info,  Node: Classes<3>,  Next: Examples<22>,  Prev: Introduction<10>,  Up: selectors — High-level I/O multiplexing

5.19.5.2 Classes
................

Classes hierarchy:

     BaseSelector
     +-- SelectSelector
     +-- PollSelector
     +-- EpollSelector
     +-- DevpollSelector
     +-- KqueueSelector

In the following, 'events' is a bitwise mask indicating which I/O events
should be waited for on a given file object.  It can be a combination of
the modules constants below:

     Constant                    Meaning
                                 
     --------------------------------------------------------------------------------
                                 
      -- Dati:                   Available for read
               selectors.EVENT_READ

      -- Dati:                   Available for write
               selectors.EVENT_WRITE

 -- Classe: selectors.SelectorKey

     A *note SelectorKey: 3a2c. is a *note namedtuple: 4e1. used to
     associate a file object to its underlying file descriptor, selected
     event mask and attached data.  It is returned by several *note
     BaseSelector: 3a27. methods.

      -- Attributo: fileobj

          File object registered.

      -- Attributo: fd

          Underlying file descriptor.

      -- Attributo: events

          Events that must be waited for on this file object.

      -- Attributo: data

          Optional opaque data associated to this file object: for
          example, this could be used to store a per-client session ID.

 -- Classe: selectors.BaseSelector

     A *note BaseSelector: 3a27. is used to wait for I/O event readiness
     on multiple file objects.  It supports file stream registration,
     unregistration, and a method to wait for I/O events on those
     streams, with an optional timeout.  It’s an abstract base class, so
     cannot be instantiated.  Use *note DefaultSelector: 3a28. instead,
     or one of *note SelectSelector: 38fa, *note KqueueSelector: 38fd.
     etc.  if you want to specifically use an implementation, and your
     platform supports it.  *note BaseSelector: 3a27. and its concrete
     implementations support the *note context manager: 1e1. protocol.

      -- Metodo: abstractmethod register (fileobj, events, data=None)

          Register a file object for selection, monitoring it for I/O
          events.

          'fileobj' is the file object to monitor.  It may either be an
          integer file descriptor or an object with a ‘fileno()’ method.
          'events' is a bitwise mask of events to monitor.  'data' is an
          opaque object.

          This returns a new *note SelectorKey: 3a2c. instance, or
          raises a *note ValueError: 2ec. in case of invalid event mask
          or file descriptor, or *note KeyError: 5e7. if the file object
          is already registered.

      -- Metodo: abstractmethod unregister (fileobj)

          Unregister a file object from selection, removing it from
          monitoring.  A file object shall be unregistered prior to
          being closed.

          'fileobj' must be a file object previously registered.

          This returns the associated *note SelectorKey: 3a2c. instance,
          or raises a *note KeyError: 5e7. if 'fileobj' is not
          registered.  It will raise *note ValueError: 2ec. if 'fileobj'
          is invalid (e.g.  it has no ‘fileno()’ method or its
          ‘fileno()’ method has an invalid return value).

      -- Metodo: modify (fileobj, events, data=None)

          Change a registered file object’s monitored events or attached
          data.

          This is equivalent to ‘BaseSelector.unregister(fileobj)’
          followed by ‘BaseSelector.register(fileobj, events, data)’,
          except that it can be implemented more efficiently.

          This returns a new *note SelectorKey: 3a2c. instance, or
          raises a *note ValueError: 2ec. in case of invalid event mask
          or file descriptor, or *note KeyError: 5e7. if the file object
          is not registered.

      -- Metodo: abstractmethod select (timeout=None)

          Wait until some registered file objects become ready, or the
          timeout expires.

          If ‘timeout > 0’, this specifies the maximum wait time, in
          seconds.  If ‘timeout <= 0’, the call won’t block, and will
          report the currently ready file objects.  If 'timeout' is
          ‘None’, the call will block until a monitored file object
          becomes ready.

          This returns a list of ‘(key, events)’ tuples, one for each
          ready file object.

          'key' is the *note SelectorKey: 3a2c. instance corresponding
          to a ready file object.  'events' is a bitmask of events ready
          on this file object.

               Nota: This method can return before any file object
               becomes ready or the timeout has elapsed if the current
               process receives a signal: in this case, an empty list
               will be returned.

          Cambiato nella versione 3.5: The selector is now retried with
          a recomputed timeout when interrupted by a signal if the
          signal handler did not raise an exception (see PEP 475(1) for
          the rationale), instead of returning an empty list of events
          before the timeout.

      -- Metodo: close ()

          Close the selector.

          This must be called to make sure that any underlying resource
          is freed.  The selector shall not be used once it has been
          closed.

      -- Metodo: get_key (fileobj)

          Return the key associated with a registered file object.

          This returns the *note SelectorKey: 3a2c. instance associated
          to this file object, or raises *note KeyError: 5e7. if the
          file object is not registered.

      -- Metodo: abstractmethod get_map ()

          Return a mapping of file objects to selector keys.

          This returns a *note Mapping: ac9. instance mapping registered
          file objects to their associated *note SelectorKey: 3a2c.
          instance.

 -- Classe: selectors.DefaultSelector

     The default selector class, using the most efficient implementation
     available on the current platform.  This should be the default
     choice for most users.

 -- Classe: selectors.SelectSelector

     *note select.select(): fa2.-based selector.

 -- Classe: selectors.PollSelector

     *note select.poll(): 308e.-based selector.

 -- Classe: selectors.EpollSelector

     *note select.epoll(): 1196.-based selector.

      -- Metodo: fileno ()

          This returns the file descriptor used by the underlying *note
          select.epoll(): 1196. object.

 -- Classe: selectors.DevpollSelector

     *note select.devpoll(): 1198.-based selector.

      -- Metodo: fileno ()

          This returns the file descriptor used by the underlying *note
          select.devpoll(): 1198. object.

     Added in version 3.5.

 -- Classe: selectors.KqueueSelector

     *note select.kqueue(): 1a2b.-based selector.

      -- Metodo: fileno ()

          This returns the file descriptor used by the underlying *note
          select.kqueue(): 1a2b. object.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0475/


File: python.info,  Node: Examples<22>,  Prev: Classes<3>,  Up: selectors — High-level I/O multiplexing

5.19.5.3 Examples
.................

Here is a simple echo server implementation:

     import selectors
     import socket

     sel = selectors.DefaultSelector()

     def accept(sock, mask):
         conn, addr = sock.accept()  # Should be ready
         print('accepted', conn, 'from', addr)
         conn.setblocking(False)
         sel.register(conn, selectors.EVENT_READ, read)

     def read(conn, mask):
         data = conn.recv(1000)  # Should be ready
         if data:
             print('echoing', repr(data), 'to', conn)
             conn.send(data)  # Hope it won't block
         else:
             print('closing', conn)
             sel.unregister(conn)
             conn.close()

     sock = socket.socket()
     sock.bind(('localhost', 1234))
     sock.listen(100)
     sock.setblocking(False)
     sel.register(sock, selectors.EVENT_READ, accept)

     while True:
         events = sel.select()
         for key, mask in events:
             callback = key.data
             callback(key.fileobj, mask)


File: python.info,  Node: signal — Set handlers for asynchronous events,  Next: mmap — Memory-mapped file support,  Prev: selectors — High-level I/O multiplexing,  Up: Networking and Interprocess Communication

5.19.6 ‘signal’ — Set handlers for asynchronous events
------------------------------------------------------

'Source code:' Lib/signal.py(1)

__________________________________________________________________

This module provides mechanisms to use signal handlers in Python.

* Menu:

* General rules::
* Module contents: Module contents<2>.
* Examples: Examples<23>.
* Note on SIGPIPE::
* Note on Signal Handlers and Exceptions::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/signal.py


File: python.info,  Node: General rules,  Next: Module contents<2>,  Up: signal — Set handlers for asynchronous events

5.19.6.1 General rules
......................

The *note signal.signal(): 133c. function allows defining custom
handlers to be executed when a signal is received.  A small number of
default handlers are installed: *note SIGPIPE: 3a3f. is ignored (so
write errors on pipes and sockets can be reported as ordinary Python
exceptions) and *note SIGINT: 253. is translated into a *note
KeyboardInterrupt: bc7. exception if the parent process has not changed
it.

A handler for a particular signal, once set, remains installed until it
is explicitly reset (Python emulates the BSD style interface regardless
of the underlying implementation), with the exception of the handler for
*note SIGCHLD: 30c9, which follows the underlying implementation.

On WebAssembly platforms, signals are emulated and therefore behave
differently.  Several functions and signals are not available on these
platforms.

* Menu:

* Execution of Python signal handlers::
* Signals and threads::


File: python.info,  Node: Execution of Python signal handlers,  Next: Signals and threads,  Up: General rules

5.19.6.2 Execution of Python signal handlers
............................................

A Python signal handler does not get executed inside the low-level (C)
signal handler.  Instead, the low-level signal handler sets a flag which
tells the *note virtual machine: 3a41. to execute the corresponding
Python signal handler at a later point(for example at the next *note
bytecode: 4ab. instruction).  This has consequences:

   * It makes little sense to catch synchronous errors like *note
     SIGFPE: 1283. or *note SIGSEGV: 1282. that are caused by an invalid
     operation in C code.  Python will return from the signal handler to
     the C code, which is likely to raise the same signal again, causing
     Python to apparently hang.  From Python 3.3 onwards, you can use
     the *note faulthandler: 5c. module to report on synchronous errors.

   * A long-running calculation implemented purely in C (such as regular
     expression matching on a large body of text) may run uninterrupted
     for an arbitrary amount of time, regardless of any signals
     received.  The Python signal handlers will be called when the
     calculation finishes.

   * If the handler raises an exception, it will be raised «out of thin
     air» in the main thread.  See the *note note below: 26cf. for a
     discussion.


File: python.info,  Node: Signals and threads,  Prev: Execution of Python signal handlers,  Up: General rules

5.19.6.3 Signals and threads
............................

Python signal handlers are always executed in the main Python thread of
the main interpreter, even if the signal was received in another thread.
This means that signals can’t be used as a means of inter-thread
communication.  You can use the synchronization primitives from the
*note threading: f3. module instead.

Besides, only the main thread of the main interpreter is allowed to set
a new signal handler.


File: python.info,  Node: Module contents<2>,  Next: Examples<23>,  Prev: General rules,  Up: signal — Set handlers for asynchronous events

5.19.6.4 Module contents
........................

Cambiato nella versione 3.5: signal (SIG*), handler (*note SIG_DFL:
1b9a, *note SIG_IGN: 1b99.) and sigmask (*note SIG_BLOCK: 3a45, *note
SIG_UNBLOCK: 3a46, *note SIG_SETMASK: 3a47.) related constants listed
below were turned into *note enums: edd. (*note Signals: 3a48, *note
Handlers: 3a49. and *note Sigmasks: 3a4a. respectively).  *note
getsignal(): 1a0d, *note pthread_sigmask(): 1338, *note sigpending():
133a. and *note sigwait(): 133b. functions return human-readable *note
enums: edd. as *note Signals: 3a48. objects.

The signal module defines three enums:

 -- Classe: signal.Signals

     *note enum.IntEnum: edd. collection of SIG* constants and the
     CTRL_* constants.

     Added in version 3.5.

 -- Classe: signal.Handlers

     *note enum.IntEnum: edd. collection the constants *note SIG_DFL:
     1b9a. and *note SIG_IGN: 1b99.

     Added in version 3.5.

 -- Classe: signal.Sigmasks

     *note enum.IntEnum: edd. collection the constants *note SIG_BLOCK:
     3a45, *note SIG_UNBLOCK: 3a46. and *note SIG_SETMASK: 3a47.

     *note Availability: 2128.: Unix.

     See the man page ‘sigprocmask(2)(1)’ and ‘pthread_sigmask(3)(2)’
     for further information.

     Added in version 3.5.

The variables defined in the *note signal: cb. module are:

 -- Dati: signal.SIG_DFL

     This is one of two standard signal handling options; it will simply
     perform the default function for the signal.  For example, on most
     systems the default action for *note SIGQUIT: 3a4b. is to dump core
     and exit, while the default action for *note SIGCHLD: 30c9. is to
     simply ignore it.

 -- Dati: signal.SIG_IGN

     This is another standard signal handler, which will simply ignore
     the given signal.

 -- Dati: signal.SIGABRT

     Abort signal from ‘abort(3)(3)’.

 -- Dati: signal.SIGALRM

     Timer signal from ‘alarm(2)(4)’.

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGBREAK

     Interrupt from keyboard (CTRL + BREAK).

     *note Availability: 2128.: Windows.

 -- Dati: signal.SIGBUS

     Bus error (bad memory access).

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGCHLD

     Child process stopped or terminated.

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGCLD

     Alias to *note SIGCHLD: 30c9.

     *note Availability: 2128.: not macOS.

 -- Dati: signal.SIGCONT

     Continue the process if it is currently stopped

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGFPE

     Floating-point exception.  For example, division by zero.

     Vedi anche
     ..........

     *note ZeroDivisionError: b41. is raised when the second argument of
     a division or modulo operation is zero.

 -- Dati: signal.SIGHUP

     Hangup detected on controlling terminal or death of controlling
     process.

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGILL

     Illegal instruction.

 -- Dati: signal.SIGINT

     Interrupt from keyboard (CTRL + C).

     Default action is to raise *note KeyboardInterrupt: bc7.

 -- Dati: signal.SIGKILL

     Kill signal.

     It cannot be caught, blocked, or ignored.

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGPIPE

     Broken pipe: write to pipe with no readers.

     Default action is to ignore the signal.

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGPROF

     Profiling timer expired.

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGQUIT

     Terminal quit signal.

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGSEGV

     Segmentation fault: invalid memory reference.

 -- Dati: signal.SIGSTOP

     Stop executing (cannot be caught or ignored).

 -- Dati: signal.SIGSTKFLT

     Stack fault on coprocessor.  The Linux kernel does not raise this
     signal: it can only be raised in user space.

     *note Availability: 2128.: Linux.

     On architectures where the signal is available.  See the man page
     ‘signal(7)(5)’ for further information.

     Added in version 3.11.

 -- Dati: signal.SIGTERM

     Termination signal.

 -- Dati: signal.SIGUSR1

     User-defined signal 1.

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGUSR2

     User-defined signal 2.

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGVTALRM

     Virtual timer expired.

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGWINCH

     Window resize signal.

     *note Availability: 2128.: Unix.

 -- Dati: signal.SIGXCPU

     CPU time limit exceeded.

     *note Availability: 2128.: Unix.

 -- Dati: SIG*

     All the signal numbers are defined symbolically.  For example, the
     hangup signal is defined as *note signal.SIGHUP: 3a4f.; the
     variable names are identical to the names used in C programs, as
     found in ‘<signal.h>’.  The Unix man page for “‘signal’” lists the
     existing signals (on some systems this is ‘signal(2)(6)’, on others
     the list is in ‘signal(7)(7)’).  Note that not all systems define
     the same set of signal names; only those names defined by the
     system are defined by this module.

 -- Dati: signal.CTRL_C_EVENT

     The signal corresponding to the ‘Ctrl’+‘C’ keystroke event.  This
     signal can only be used with *note os.kill(): 156f.

     *note Availability: 2128.: Windows.

     Added in version 3.2.

 -- Dati: signal.CTRL_BREAK_EVENT

     The signal corresponding to the ‘Ctrl’+‘Break’ keystroke event.
     This signal can only be used with *note os.kill(): 156f.

     *note Availability: 2128.: Windows.

     Added in version 3.2.

 -- Dati: signal.NSIG

     One more than the number of the highest signal number.  Use *note
     valid_signals(): 3a57. to get valid signal numbers.

 -- Dati: signal.ITIMER_REAL

     Decrements interval timer in real time, and delivers *note SIGALRM:
     3a4c. upon expiration.

 -- Dati: signal.ITIMER_VIRTUAL

     Decrements interval timer only when the process is executing, and
     delivers SIGVTALRM upon expiration.

 -- Dati: signal.ITIMER_PROF

     Decrements interval timer both when the process executes and when
     the system is executing on behalf of the process.  Coupled with
     ITIMER_VIRTUAL, this timer is usually used to profile the time
     spent by the application in user and kernel space.  SIGPROF is
     delivered upon expiration.

 -- Dati: signal.SIG_BLOCK

     A possible value for the 'how' parameter to *note
     pthread_sigmask(): 1338. indicating that signals are to be blocked.

     Added in version 3.3.

 -- Dati: signal.SIG_UNBLOCK

     A possible value for the 'how' parameter to *note
     pthread_sigmask(): 1338. indicating that signals are to be
     unblocked.

     Added in version 3.3.

 -- Dati: signal.SIG_SETMASK

     A possible value for the 'how' parameter to *note
     pthread_sigmask(): 1338. indicating that the signal mask is to be
     replaced.

     Added in version 3.3.

The *note signal: cb. module defines one exception:

 -- Eccezione: signal.ItimerError

     Raised to signal an error from the underlying *note setitimer():
     3a5c. or *note getitimer(): 3a5d. implementation.  Expect this
     error if an invalid interval timer or a negative time is passed to
     *note setitimer(): 3a5c.  This error is a subtype of *note OSError:
     2c0.

     Added in version 3.3: This error used to be a subtype of *note
     IOError: 1255, which is now an alias of *note OSError: 2c0.

The *note signal: cb. module defines the following functions:

 -- Funzione: signal.alarm (time)

     If 'time' is non-zero, this function requests that a *note SIGALRM:
     3a4c. signal be sent to the process in 'time' seconds.  Any
     previously scheduled alarm is canceled (only one alarm can be
     scheduled at any time).  The returned value is then the number of
     seconds before any previously set alarm was to have been delivered.
     If 'time' is zero, no alarm is scheduled, and any scheduled alarm
     is canceled.  If the return value is zero, no alarm is currently
     scheduled.

     *note Availability: 2128.: Unix.

     See the man page ‘alarm(2)(8)’ for further information.

 -- Funzione: signal.getsignal (signalnum)

     Return the current signal handler for the signal 'signalnum'.  The
     returned value may be a callable Python object, or one of the
     special values *note signal.SIG_IGN: 1b99, *note signal.SIG_DFL:
     1b9a. or *note None: 886.  Here, *note signal.SIG_IGN: 1b99. means
     that the signal was previously ignored, *note signal.SIG_DFL: 1b9a.
     means that the default way of handling the signal was previously in
     use, and ‘None’ means that the previous signal handler was not
     installed from Python.

 -- Funzione: signal.strsignal (signalnum)

     Returns the description of signal 'signalnum', such as «Interrupt»
     for *note SIGINT: 253.  Returns *note None: 886. if 'signalnum' has
     no description.  Raises *note ValueError: 2ec. if 'signalnum' is
     invalid.

     Added in version 3.8.

 -- Funzione: signal.valid_signals ()

     Return the set of valid signal numbers on this platform.  This can
     be less than ‘range(1, NSIG)’ if some signals are reserved by the
     system for internal use.

     Added in version 3.8.

 -- Funzione: signal.pause ()

     Cause the process to sleep until a signal is received; the
     appropriate handler will then be called.  Returns nothing.

     *note Availability: 2128.: Unix.

     See the man page ‘signal(2)(9)’ for further information.

     See also *note sigwait(): 133b, *note sigwaitinfo(): fad, *note
     sigtimedwait(): fac. and *note sigpending(): 133a.

 -- Funzione: signal.raise_signal (signum)

     Sends a signal to the calling process.  Returns nothing.

     Added in version 3.8.

 -- Funzione: signal.pidfd_send_signal (pidfd, sig, siginfo=None,
          flags=0)

     Send signal 'sig' to the process referred to by file descriptor
     'pidfd'.  Python does not currently support the 'siginfo'
     parameter; it must be ‘None’.  The 'flags' argument is provided for
     future extensions; no flag values are currently defined.

     See the ‘pidfd_send_signal(2)(10)’ man page for more information.

     *note Availability: 2128.: Linux >= 5.1, Android >= *note
     build-time: d85. API level 31

     Added in version 3.9.

 -- Funzione: signal.pthread_kill (thread_id, signalnum)

     Send the signal 'signalnum' to the thread 'thread_id', another
     thread in the same process as the caller.  The target thread can be
     executing any code (Python or not).  However, if the target thread
     is executing the Python interpreter, the Python signal handlers
     will be *note executed by the main thread of the main interpreter:
     3a43.  Therefore, the only point of sending a signal to a
     particular Python thread would be to force a running system call to
     fail with *note InterruptedError: f8a.

     Use *note threading.get_ident(): 1362. or the *note ident: 311c.
     attribute of *note threading.Thread: 176. objects to get a suitable
     value for 'thread_id'.

     If 'signalnum' is 0, then no signal is sent, but error checking is
     still performed; this can be used to check if the target thread is
     still running.

     Raises an *note auditing event: 1c56. ‘signal.pthread_kill’ with
     arguments ‘thread_id’, ‘signalnum’.

     *note Availability: 2128.: Unix.

     See the man page ‘pthread_kill(3)(11)’ for further information.

     See also *note os.kill(): 156f.

     Added in version 3.3.

 -- Funzione: signal.pthread_sigmask (how, mask)

     Fetch and/or change the signal mask of the calling thread.  The
     signal mask is the set of signals whose delivery is currently
     blocked for the caller.  Return the old signal mask as a set of
     signals.

     The behavior of the call is dependent on the value of 'how', as
     follows.

        * *note SIG_BLOCK: 3a45.: The set of blocked signals is the
          union of the current set and the 'mask' argument.

        * *note SIG_UNBLOCK: 3a46.: The signals in 'mask' are removed
          from the current set of blocked signals.  It is permissible to
          attempt to unblock a signal which is not blocked.

        * *note SIG_SETMASK: 3a47.: The set of blocked signals is set to
          the 'mask' argument.

     'mask' is a set of signal numbers (e.g.  {*note signal.SIGINT: 253,
     *note signal.SIGTERM: 15e6.}).  Use *note valid_signals(): 3a57.
     for a full mask including all signals.

     For example, ‘signal.pthread_sigmask(signal.SIG_BLOCK, [])’ reads
     the signal mask of the calling thread.

     *note SIGKILL: d52. and *note SIGSTOP: 3a51. cannot be blocked.

     *note Availability: 2128.: Unix.

     See the man page ‘sigprocmask(2)(12)’ and ‘pthread_sigmask(3)(13)’
     for further information.

     See also *note pause(): 3a5f, *note sigpending(): 133a. and *note
     sigwait(): 133b.

     Added in version 3.3.

 -- Funzione: signal.setitimer (which, seconds, interval=0.0)

     Sets given interval timer (one of *note signal.ITIMER_REAL: 3a58,
     *note signal.ITIMER_VIRTUAL: 3a59. or *note signal.ITIMER_PROF:
     3a5a.) specified by 'which' to fire after 'seconds' (float is
     accepted, different from *note alarm(): 3a5e.) and after that every
     'interval' seconds (if 'interval' is non-zero).  The interval timer
     specified by 'which' can be cleared by setting 'seconds' to zero.

     When an interval timer fires, a signal is sent to the process.  The
     signal sent is dependent on the timer being used; *note
     signal.ITIMER_REAL: 3a58. will deliver *note SIGALRM: 3a4c, *note
     signal.ITIMER_VIRTUAL: 3a59. sends *note SIGVTALRM: 3a54, and *note
     signal.ITIMER_PROF: 3a5a. will deliver *note SIGPROF: 3a50.

     The old values are returned as a tuple: (delay, interval).

     Attempting to pass an invalid interval timer will cause an *note
     ItimerError: 3a5b.

     *note Availability: 2128.: Unix.

 -- Funzione: signal.getitimer (which)

     Returns current value of a given interval timer specified by
     'which'.

     *note Availability: 2128.: Unix.

 -- Funzione: signal.set_wakeup_fd (fd, *, warn_on_full_buffer=True)

     Set the wakeup file descriptor to 'fd'.  When a signal your program
     has registered a signal handler for is received, the signal number
     is written as a single byte into the fd.  If you haven’t registered
     a signal handler for the signals you care about, then nothing will
     be written to the wakeup fd.  This can be used by a library to
     wakeup a poll or select call, allowing the signal to be fully
     processed.

     The old wakeup fd is returned (or -1 if file descriptor wakeup was
     not enabled).  If 'fd' is -1, file descriptor wakeup is disabled.
     If not -1, 'fd' must be non-blocking.  It is up to the library to
     remove any bytes from 'fd' before calling poll or select again.

     When threads are enabled, this function can only be called from
     *note the main thread of the main interpreter: 3a43.; attempting to
     call it from other threads will cause a *note ValueError: 2ec.
     exception to be raised.

     There are two common ways to use this function.  In both
     approaches, you use the fd to wake up when a signal arrives, but
     then they differ in how they determine 'which' signal or signals
     have arrived.

     In the first approach, we read the data out of the fd’s buffer, and
     the byte values give you the signal numbers.  This is simple, but
     in rare cases it can run into a problem: generally the fd will have
     a limited amount of buffer space, and if too many signals arrive
     too quickly, then the buffer may become full, and some signals may
     be lost.  If you use this approach, then you should set
     ‘warn_on_full_buffer=True’, which will at least cause a warning to
     be printed to stderr when signals are lost.

     In the second approach, we use the wakeup fd 'only' for wakeups,
     and ignore the actual byte values.  In this case, all we care about
     is whether the fd’s buffer is empty or non-empty; a full buffer
     doesn’t indicate a problem at all.  If you use this approach, then
     you should set ‘warn_on_full_buffer=False’, so that your users are
     not confused by spurious warning messages.

     Cambiato nella versione 3.5: On Windows, the function now also
     supports socket handles.

     Cambiato nella versione 3.7: Added ‘warn_on_full_buffer’ parameter.

 -- Funzione: signal.siginterrupt (signalnum, flag)

     Change system call restart behaviour: if 'flag' is *note False:
     d2d, system calls will be restarted when interrupted by signal
     'signalnum', otherwise system calls will be interrupted.  Returns
     nothing.

     *note Availability: 2128.: Unix.

     See the man page ‘siginterrupt(3)(14)’ for further information.

     Note that installing a signal handler with *note signal(): cb. will
     reset the restart behaviour to interruptible by implicitly calling
     ‘siginterrupt()’ with a true 'flag' value for the given signal.

 -- Funzione: signal.signal (signalnum, handler)

     Set the handler for signal 'signalnum' to the function 'handler'.
     'handler' can be a callable Python object taking two arguments (see
     below), or one of the special values *note signal.SIG_IGN: 1b99. or
     *note signal.SIG_DFL: 1b9a.  The previous signal handler will be
     returned (see the description of *note getsignal(): 1a0d. above).
     (See the Unix man page ‘signal(2)(15)’ for further information.)

     When threads are enabled, this function can only be called from
     *note the main thread of the main interpreter: 3a43.; attempting to
     call it from other threads will cause a *note ValueError: 2ec.
     exception to be raised.

     The 'handler' is called with two arguments: the signal number and
     the current stack frame (‘None’ or a frame object; for a
     description of frame objects, see the *note description in the type
     hierarchy: 8f0. or see the attribute descriptions in the *note
     inspect: 82. module).

     On Windows, *note signal(): cb. can only be called with *note
     SIGABRT: 1284, *note SIGFPE: 1283, *note SIGILL: 1286, *note
     SIGINT: 253, *note SIGSEGV: 1282, *note SIGTERM: 15e6, or *note
     SIGBREAK: 3a4d.  A *note ValueError: 2ec. will be raised in any
     other case.  Note that not all systems define the same set of
     signal names; an *note AttributeError: 5f0. will be raised if a
     signal name is not defined as ‘SIG*’ module level constant.

 -- Funzione: signal.sigpending ()

     Examine the set of signals that are pending for delivery to the
     calling thread (i.e., the signals which have been raised while
     blocked).  Return the set of the pending signals.

     *note Availability: 2128.: Unix.

     See the man page ‘sigpending(2)(16)’ for further information.

     See also *note pause(): 3a5f, *note pthread_sigmask(): 1338. and
     *note sigwait(): 133b.

     Added in version 3.3.

 -- Funzione: signal.sigwait (sigset)

     Suspend execution of the calling thread until the delivery of one
     of the signals specified in the signal set 'sigset'.  The function
     accepts the signal (removes it from the pending list of signals),
     and returns the signal number.

     *note Availability: 2128.: Unix.

     See the man page ‘sigwait(3)(17)’ for further information.

     See also *note pause(): 3a5f, *note pthread_sigmask(): 1338, *note
     sigpending(): 133a, *note sigwaitinfo(): fad. and *note
     sigtimedwait(): fac.

     Added in version 3.3.

 -- Funzione: signal.sigwaitinfo (sigset)

     Suspend execution of the calling thread until the delivery of one
     of the signals specified in the signal set 'sigset'.  The function
     accepts the signal and removes it from the pending list of signals.
     If one of the signals in 'sigset' is already pending for the
     calling thread, the function will return immediately with
     information about that signal.  The signal handler is not called
     for the delivered signal.  The function raises an *note
     InterruptedError: f8a. if it is interrupted by a signal that is not
     in 'sigset'.

     The return value is an object representing the data contained in
     the ‘siginfo_t’ structure, namely: ‘si_signo’, ‘si_code’,
     ‘si_errno’, ‘si_pid’, ‘si_uid’, ‘si_status’, ‘si_band’.

     *note Availability: 2128.: Unix.

     See the man page ‘sigwaitinfo(2)(18)’ for further information.

     See also *note pause(): 3a5f, *note sigwait(): 133b. and *note
     sigtimedwait(): fac.

     Added in version 3.3.

     Cambiato nella versione 3.5: The function is now retried if
     interrupted by a signal not in 'sigset' and the signal handler does
     not raise an exception (see PEP 475(19) for the rationale).

 -- Funzione: signal.sigtimedwait (sigset, timeout)

     Like *note sigwaitinfo(): fad, but takes an additional 'timeout'
     argument specifying a timeout.  If 'timeout' is specified as ‘0’, a
     poll is performed.  Returns *note None: 886. if a timeout occurs.

     *note Availability: 2128.: Unix.

     See the man page ‘sigtimedwait(2)(20)’ for further information.

     See also *note pause(): 3a5f, *note sigwait(): 133b. and *note
     sigwaitinfo(): fad.

     Added in version 3.3.

     Cambiato nella versione 3.5: The function is now retried with the
     recomputed 'timeout' if interrupted by a signal not in 'sigset' and
     the signal handler does not raise an exception (see PEP 475(21) for
     the rationale).

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/sigprocmask(2)

   (2) https://manpages.debian.org/pthread_sigmask(3)

   (3) https://manpages.debian.org/abort(3)

   (4) https://manpages.debian.org/alarm(2)

   (5) https://manpages.debian.org/signal(7)

   (6) https://manpages.debian.org/signal(2)

   (7) https://manpages.debian.org/signal(7)

   (8) https://manpages.debian.org/alarm(2)

   (9) https://manpages.debian.org/signal(2)

   (10) https://manpages.debian.org/pidfd_send_signal(2)

   (11) https://manpages.debian.org/pthread_kill(3)

   (12) https://manpages.debian.org/sigprocmask(2)

   (13) https://manpages.debian.org/pthread_sigmask(3)

   (14) https://manpages.debian.org/siginterrupt(3)

   (15) https://manpages.debian.org/signal(2)

   (16) https://manpages.debian.org/sigpending(2)

   (17) https://manpages.debian.org/sigwait(3)

   (18) https://manpages.debian.org/sigwaitinfo(2)

   (19) https://peps.python.org/pep-0475/

   (20) https://manpages.debian.org/sigtimedwait(2)

   (21) https://peps.python.org/pep-0475/


File: python.info,  Node: Examples<23>,  Next: Note on SIGPIPE,  Prev: Module contents<2>,  Up: signal — Set handlers for asynchronous events

5.19.6.5 Examples
.................

Here is a minimal example program.  It uses the *note alarm(): 3a5e.
function to limit the time spent waiting to open a file; this is useful
if the file is for a serial device that may not be turned on, which
would normally cause the *note os.open(): f94. to hang indefinitely.
The solution is to set a 5-second alarm before opening the file; if the
operation takes too long, the alarm signal will be sent, and the handler
raises an exception.

     import signal, os

     def handler(signum, frame):
         signame = signal.Signals(signum).name
         print(f'Signal handler called with signal {signame} ({signum})')
         raise OSError("Couldn't open device!")

     # Set the signal handler and a 5-second alarm
     signal.signal(signal.SIGALRM, handler)
     signal.alarm(5)

     # This open() may hang indefinitely
     fd = os.open('/dev/ttyS0', os.O_RDWR)

     signal.alarm(0)          # Disable the alarm


File: python.info,  Node: Note on SIGPIPE,  Next: Note on Signal Handlers and Exceptions,  Prev: Examples<23>,  Up: signal — Set handlers for asynchronous events

5.19.6.6 Note on SIGPIPE
........................

Piping output of your program to tools like ‘head(1)(1)’ will cause a
*note SIGPIPE: 3a3f. signal to be sent to your process when the receiver
of its standard output closes early.  This results in an exception like
‘BrokenPipeError: [Errno 32] Broken pipe’.  To handle this case, wrap
your entry point to catch this exception as follows:

     import os
     import sys

     def main():
         try:
             # simulate large output (your code replaces this loop)
             for x in range(10000):
                 print("y")
             # flush output here to force SIGPIPE to be triggered
             # while inside this try block.
             sys.stdout.flush()
         except BrokenPipeError:
             # Python flushes standard streams on exit; redirect remaining output
             # to devnull to avoid another BrokenPipeError at shutdown
             devnull = os.open(os.devnull, os.O_WRONLY)
             os.dup2(devnull, sys.stdout.fileno())
             sys.exit(1)  # Python exits with error code 1 on EPIPE

     if __name__ == '__main__':
         main()

Do not set *note SIGPIPE: 3a3f.’s disposition to *note SIG_DFL: 1b9a. in
order to avoid *note BrokenPipeError: 125e.  Doing that would cause your
program to exit unexpectedly whenever any socket connection is
interrupted while your program is still writing to it.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/head(1)


File: python.info,  Node: Note on Signal Handlers and Exceptions,  Prev: Note on SIGPIPE,  Up: signal — Set handlers for asynchronous events

5.19.6.7 Note on Signal Handlers and Exceptions
...............................................

If a signal handler raises an exception, the exception will be
propagated to the main thread and may be raised after any *note
bytecode: 4ab. instruction.  Most notably, a *note KeyboardInterrupt:
bc7. may appear at any point during execution.  Most Python code,
including the standard library, cannot be made robust against this, and
so a *note KeyboardInterrupt: bc7. (or any other exception resulting
from a signal handler) may on rare occasions put the program in an
unexpected state.

To illustrate this issue, consider the following code:

     class SpamContext:
         def __init__(self):
             self.lock = threading.Lock()

         def __enter__(self):
             # If KeyboardInterrupt occurs here, everything is fine
             self.lock.acquire()
             # If KeyboardInterrupt occurs here, __exit__ will not be called
             ...
             # KeyboardInterrupt could occur just before the function returns

         def __exit__(self, exc_type, exc_val, exc_tb):
             ...
             self.lock.release()

For many programs, especially those that merely want to exit on *note
KeyboardInterrupt: bc7, this is not a problem, but applications that are
complex or require high reliability should avoid raising exceptions from
signal handlers.  They should also avoid catching *note
KeyboardInterrupt: bc7. as a means of gracefully shutting down.
Instead, they should install their own *note SIGINT: 253. handler.
Below is an example of an HTTP server that avoids *note
KeyboardInterrupt: bc7.:

     import signal
     import socket
     from selectors import DefaultSelector, EVENT_READ
     from http.server import HTTPServer, SimpleHTTPRequestHandler

     interrupt_read, interrupt_write = socket.socketpair()

     def handler(signum, frame):
         print('Signal handler called with signal', signum)
         interrupt_write.send(b'\0')
     signal.signal(signal.SIGINT, handler)

     def serve_forever(httpd):
         sel = DefaultSelector()
         sel.register(interrupt_read, EVENT_READ)
         sel.register(httpd, EVENT_READ)

         while True:
             for key, _ in sel.select():
                 if key.fileobj == interrupt_read:
                     interrupt_read.recv(1)
                     return
                 if key.fileobj == httpd:
                     httpd.handle_request()

     print("Serving on port 8000")
     httpd = HTTPServer(('', 8000), SimpleHTTPRequestHandler)
     serve_forever(httpd)
     print("Shutdown...")


File: python.info,  Node: mmap — Memory-mapped file support,  Prev: signal — Set handlers for asynchronous events,  Up: Networking and Interprocess Communication

5.19.7 ‘mmap’ — Memory-mapped file support
------------------------------------------

__________________________________________________________________

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

Memory-mapped file objects behave like both *note bytearray: 344. and
like *note file objects: 13cb.  You can use mmap objects in most places
where *note bytearray: 344. are expected; for example, you can use the
*note re: be. module to search through a memory-mapped file.  You can
also change a single byte by doing ‘obj[index] = 97’, or change a
subsequence by assigning to a slice: ‘obj[i1:i2] = b'...'’.  You can
also read and write data starting at the current file position, and
‘seek()’ through the file to different positions.

A memory-mapped file is created by the *note mmap: 51a. constructor,
which is different on Unix and on Windows.  In either case you must
provide a file descriptor for a file opened for update.  If you wish to
map an existing Python file object, use its *note fileno(): 1795. method
to obtain the correct value for the 'fileno' parameter.  Otherwise, you
can open the file using the *note os.open(): f94. function, which
returns a file descriptor directly (the file still needs to be closed
when done).

     Nota: If you want to create a memory-mapping for a writable,
     buffered file, you should *note flush(): 2ccc. the file first.
     This is necessary to ensure that local modifications to the buffers
     are actually available to the mapping.

For both the Unix and Windows versions of the constructor, 'access' may
be specified as an optional keyword parameter.  'access' accepts one of
four values: ‘ACCESS_READ’, ‘ACCESS_WRITE’, or ‘ACCESS_COPY’ to specify
read-only, write-through or copy-on-write memory respectively, or
‘ACCESS_DEFAULT’ to defer to 'prot'.  'access' can be used on both Unix
and Windows.  If 'access' is not specified, Windows mmap returns a
write-through mapping.  The initial memory values for all three access
types are taken from the specified file.  Assignment to an ‘ACCESS_READ’
memory map raises a *note TypeError: 198. exception.  Assignment to an
‘ACCESS_WRITE’ memory map affects both memory and the underlying file.
Assignment to an ‘ACCESS_COPY’ memory map affects memory but does not
update the underlying file.

Cambiato nella versione 3.7: Added ‘ACCESS_DEFAULT’ constant.

To map anonymous memory, -1 should be passed as the fileno along with
the length.

 -- Classe: mmap.mmap (fileno, length, tagname=None,
          access=ACCESS_DEFAULT, offset=0)

     '(Windows version)' Maps 'length' bytes from the file specified by
     the file handle 'fileno', and creates a mmap object.  If 'length'
     is larger than the current size of the file, the file is extended
     to contain 'length' bytes.  If 'length' is ‘0’, the maximum length
     of the map is the current size of the file, except that if the file
     is empty Windows raises an exception (you cannot create an empty
     mapping on Windows).

     'tagname', if specified and not ‘None’, is a string giving a tag
     name for the mapping.  Windows allows you to have many different
     mappings against the same file.  If you specify the name of an
     existing tag, that tag is opened, otherwise a new tag of this name
     is created.  If this parameter is omitted or ‘None’, the mapping is
     created without a name.  Avoiding the use of the 'tagname'
     parameter will assist in keeping your code portable between Unix
     and Windows.

     'offset' may be specified as a non-negative integer offset.  mmap
     references will be relative to the offset from the beginning of the
     file.  'offset' defaults to 0.  'offset' must be a multiple of the
     ‘ALLOCATIONGRANULARITY’.

     Raises an *note auditing event: 1c56. ‘mmap.__new__’ with arguments
     ‘fileno’, ‘length’, ‘access’, ‘offset’.

 -- Classe: mmap.mmap (fileno, length, flags=MAP_SHARED, prot=PROT_WRITE
          | PROT_READ, access=ACCESS_DEFAULT, offset=0, *, trackfd=True)

     '(Unix version)' Maps 'length' bytes from the file specified by the
     file descriptor 'fileno', and returns a mmap object.  If 'length'
     is ‘0’, the maximum length of the map will be the current size of
     the file when *note mmap: 51a. is called.

     'flags' specifies the nature of the mapping.  *note MAP_PRIVATE:
     3a67. creates a private copy-on-write mapping, so changes to the
     contents of the mmap object will be private to this process, and
     *note MAP_SHARED: 3a68. creates a mapping that’s shared with all
     other processes mapping the same areas of the file.  The default
     value is *note MAP_SHARED: 3a68.  Some systems have additional
     possible flags with the full list specified in *note MAP_*
     constants: 3a69.

     'prot', if specified, gives the desired memory protection; the two
     most useful values are ‘PROT_READ’ and ‘PROT_WRITE’, to specify
     that the pages may be read or written.  'prot' defaults to
     ‘PROT_READ | PROT_WRITE’.

     'access' may be specified in lieu of 'flags' and 'prot' as an
     optional keyword parameter.  It is an error to specify both
     'flags', 'prot' and 'access'.  See the description of 'access'
     above for information on how to use this parameter.

     'offset' may be specified as a non-negative integer offset.  mmap
     references will be relative to the offset from the beginning of the
     file.  'offset' defaults to 0.  'offset' must be a multiple of
     ‘ALLOCATIONGRANULARITY’ which is equal to ‘PAGESIZE’ on Unix
     systems.

     If 'trackfd' is ‘False’, the file descriptor specified by 'fileno'
     will not be duplicated, and the resulting ‘mmap’ object will not be
     associated with the map’s underlying file.  This means that the
     *note size(): 3a6a. and *note resize(): 3a6b. methods will fail.
     This mode is useful to limit the number of open file descriptors.

     To ensure validity of the created memory mapping the file specified
     by the descriptor 'fileno' is internally automatically synchronized
     with the physical backing store on macOS.

     Cambiato nella versione 3.13: The 'trackfd' parameter was added.

     This example shows a simple way of using *note mmap: 51a.:

          import mmap

          # write a simple example file
          with open("hello.txt", "wb") as f:
              f.write(b"Hello Python!\n")

          with open("hello.txt", "r+b") as f:
              # memory-map the file, size 0 means whole file
              mm = mmap.mmap(f.fileno(), 0)
              # read content via standard file methods
              print(mm.readline())  # prints b"Hello Python!\n"
              # read content via slice notation
              print(mm[:5])  # prints b"Hello"
              # update content using slice notation;
              # note that new content must have same size
              mm[6:] = b" world!\n"
              # ... and read again using standard file methods
              mm.seek(0)
              print(mm.readline())  # prints b"Hello  world!\n"
              # close the map
              mm.close()

     *note mmap: 51a. can also be used as a context manager in a *note
     with: 186. statement:

          import mmap

          with mmap.mmap(-1, 13) as mm:
              mm.write(b"Hello world!")

     Added in version 3.2: Context manager support.

     The next example demonstrates how to create an anonymous map and
     exchange data between the parent and child processes:

          import mmap
          import os

          mm = mmap.mmap(-1, 13)
          mm.write(b"Hello world!")

          pid = os.fork()

          if pid == 0:  # In a child process
              mm.seek(0)
              print(mm.readline())

              mm.close()

     Raises an *note auditing event: 1c56. ‘mmap.__new__’ with arguments
     ‘fileno’, ‘length’, ‘access’, ‘offset’.

     Memory-mapped file objects support the following methods:

      -- Metodo: close ()

          Closes the mmap.  Subsequent calls to other methods of the
          object will result in a ValueError exception being raised.
          This will not close the open file.

      -- Attributo: closed

          ‘True’ if the file is closed.

          Added in version 3.2.

      -- Metodo: find (sub[, start[, end]])

          Returns the lowest index in the object where the subsequence
          'sub' is found, such that 'sub' is contained in the range
          ['start', 'end'].  Optional arguments 'start' and 'end' are
          interpreted as in slice notation.  Returns ‘-1’ on failure.

          Cambiato nella versione 3.5: Writable *note bytes-like object:
          193. is now accepted.

      -- Metodo: flush ()

      -- Metodo: flush (offset, size, /)

          Flushes changes made to the in-memory copy of a file back to
          disk.  Without use of this call there is no guarantee that
          changes are written back before the object is destroyed.  If
          'offset' and 'size' are specified, only changes to the given
          range of bytes will be flushed to disk; otherwise, the whole
          extent of the mapping is flushed.  'offset' must be a multiple
          of the ‘PAGESIZE’ or ‘ALLOCATIONGRANULARITY’.

          ‘None’ is returned to indicate success.  An exception is
          raised when the call failed.

          Cambiato nella versione 3.8: Previously, a nonzero value was
          returned on success; zero was returned on error under Windows.
          A zero value was returned on success; an exception was raised
          on error under Unix.

      -- Metodo: madvise (option[, start[, length]])

          Send advice 'option' to the kernel about the memory region
          beginning at 'start' and extending 'length' bytes.  'option'
          must be one of the *note MADV_* constants: 3a6f. available on
          the system.  If 'start' and 'length' are omitted, the entire
          mapping is spanned.  On some systems (including Linux),
          'start' must be a multiple of the ‘PAGESIZE’.

          Availability: Systems with the ‘madvise()’ system call.

          Added in version 3.8.

      -- Metodo: move (dest, src, count)

          Copy the 'count' bytes starting at offset 'src' to the
          destination index 'dest'.  If the mmap was created with
          ‘ACCESS_READ’, then calls to move will raise a *note
          TypeError: 198. exception.

      -- Metodo: read ([n])

          Return a *note bytes: 192. containing up to 'n' bytes starting
          from the current file position.  If the argument is omitted,
          ‘None’ or negative, return all bytes from the current file
          position to the end of the mapping.  The file position is
          updated to point after the bytes that were returned.

          Cambiato nella versione 3.3: Argument can be omitted or
          ‘None’.

      -- Metodo: read_byte ()

          Returns a byte at the current file position as an integer, and
          advances the file position by 1.

      -- Metodo: readline ()

          Returns a single line, starting at the current file position
          and up to the next newline.  The file position is updated to
          point after the bytes that were returned.

      -- Metodo: resize (newsize)

          Resizes the map and the underlying file, if any.

          Resizing a map created with 'access' of ‘ACCESS_READ’ or
          ‘ACCESS_COPY’, will raise a *note TypeError: 198. exception.
          Resizing a map created with 'trackfd' set to ‘False’, will
          raise a *note ValueError: 2ec. exception.

          'On Windows': Resizing the map will raise an *note OSError:
          2c0. if there are other maps against the same named file.
          Resizing an anonymous map (ie against the pagefile) will
          silently create a new map with the original data copied over
          up to the length of the new size.

          Cambiato nella versione 3.11: Correctly fails if attempting to
          resize when another map is held Allows resize against an
          anonymous map on Windows

      -- Metodo: rfind (sub[, start[, end]])

          Returns the highest index in the object where the subsequence
          'sub' is found, such that 'sub' is contained in the range
          ['start', 'end'].  Optional arguments 'start' and 'end' are
          interpreted as in slice notation.  Returns ‘-1’ on failure.

          Cambiato nella versione 3.5: Writable *note bytes-like object:
          193. is now accepted.

      -- Metodo: seek (pos[, whence])

          Set the file’s current position.  'whence' argument is
          optional and defaults to ‘os.SEEK_SET’ or ‘0’ (absolute file
          positioning); other values are ‘os.SEEK_CUR’ or ‘1’ (seek
          relative to the current position) and ‘os.SEEK_END’ or ‘2’
          (seek relative to the file’s end).

          Cambiato nella versione 3.13: Return the new absolute position
          instead of ‘None’.

      -- Metodo: seekable ()

          Return whether the file supports seeking, and the return value
          is always ‘True’.

          Added in version 3.13.

      -- Metodo: size ()

          Return the length of the file, which can be larger than the
          size of the memory-mapped area.

      -- Metodo: tell ()

          Returns the current position of the file pointer.

      -- Metodo: write (bytes)

          Write the bytes in 'bytes' into memory at the current position
          of the file pointer and return the number of bytes written
          (never less than ‘len(bytes)’, since if the write fails, a
          *note ValueError: 2ec. will be raised).  The file position is
          updated to point after the bytes that were written.  If the
          mmap was created with ‘ACCESS_READ’, then writing to it will
          raise a *note TypeError: 198. exception.

          Cambiato nella versione 3.5: Writable *note bytes-like object:
          193. is now accepted.

          Cambiato nella versione 3.6: The number of bytes written is
          now returned.

      -- Metodo: write_byte (byte)

          Write the integer 'byte' into memory at the current position
          of the file pointer; the file position is advanced by ‘1’.  If
          the mmap was created with ‘ACCESS_READ’, then writing to it
          will raise a *note TypeError: 198. exception.

* Menu:

* MADV_* Constants::
* MAP_* Constants::


File: python.info,  Node: MADV_* Constants,  Next: MAP_* Constants,  Up: mmap — Memory-mapped file support

5.19.7.1 MADV_* Constants
.........................

 -- Dati: mmap.MADV_NORMAL
 -- Dati: mmap.MADV_RANDOM
 -- Dati: mmap.MADV_SEQUENTIAL
 -- Dati: mmap.MADV_WILLNEED
 -- Dati: mmap.MADV_DONTNEED
 -- Dati: mmap.MADV_REMOVE
 -- Dati: mmap.MADV_DONTFORK
 -- Dati: mmap.MADV_DOFORK
 -- Dati: mmap.MADV_HWPOISON
 -- Dati: mmap.MADV_MERGEABLE
 -- Dati: mmap.MADV_UNMERGEABLE
 -- Dati: mmap.MADV_SOFT_OFFLINE
 -- Dati: mmap.MADV_HUGEPAGE
 -- Dati: mmap.MADV_NOHUGEPAGE
 -- Dati: mmap.MADV_DONTDUMP
 -- Dati: mmap.MADV_DODUMP
 -- Dati: mmap.MADV_FREE
 -- Dati: mmap.MADV_NOSYNC
 -- Dati: mmap.MADV_AUTOSYNC
 -- Dati: mmap.MADV_NOCORE
 -- Dati: mmap.MADV_CORE
 -- Dati: mmap.MADV_PROTECT
 -- Dati: mmap.MADV_FREE_REUSABLE
 -- Dati: mmap.MADV_FREE_REUSE

     These options can be passed to *note mmap.madvise(): bfd.  Not
     every option will be present on every system.

     Availability: Systems with the madvise() system call.

     Added in version 3.8.


File: python.info,  Node: MAP_* Constants,  Prev: MADV_* Constants,  Up: mmap — Memory-mapped file support

5.19.7.2 MAP_* Constants
........................

 -- Dati: mmap.MAP_SHARED
 -- Dati: mmap.MAP_PRIVATE
 -- Dati: mmap.MAP_32BIT
 -- Dati: mmap.MAP_ALIGNED_SUPER
 -- Dati: mmap.MAP_ANON
 -- Dati: mmap.MAP_ANONYMOUS
 -- Dati: mmap.MAP_CONCEAL
 -- Dati: mmap.MAP_DENYWRITE
 -- Dati: mmap.MAP_EXECUTABLE
 -- Dati: mmap.MAP_HASSEMAPHORE
 -- Dati: mmap.MAP_JIT
 -- Dati: mmap.MAP_NOCACHE
 -- Dati: mmap.MAP_NOEXTEND
 -- Dati: mmap.MAP_NORESERVE
 -- Dati: mmap.MAP_POPULATE
 -- Dati: mmap.MAP_RESILIENT_CODESIGN
 -- Dati: mmap.MAP_RESILIENT_MEDIA
 -- Dati: mmap.MAP_STACK
 -- Dati: mmap.MAP_TPRO
 -- Dati: mmap.MAP_TRANSLATED_ALLOW_EXECUTE
 -- Dati: mmap.MAP_UNIX03

     These are the various flags that can be passed to *note
     mmap.mmap(): 51a.  *note MAP_ALIGNED_SUPER: 1aaf. is only available
     at FreeBSD and *note MAP_CONCEAL: 1ab0. is only available at
     OpenBSD. Note that some options might not be present on some
     systems.

     Cambiato nella versione 3.10: Added *note MAP_POPULATE: 1d17.
     constant.

     Added in version 3.11: Added *note MAP_STACK: 3a94. constant.

     Added in version 3.12: Added *note MAP_ALIGNED_SUPER: 1aaf. and
     *note MAP_CONCEAL: 1ab0. constants.

     Added in version 3.13: Added *note MAP_32BIT: 1a04, *note
     MAP_HASSEMAPHORE: 19ff, *note MAP_JIT: 1a01, *note MAP_NOCACHE:
     1a00, *note MAP_NOEXTEND: 19fe, *note MAP_NORESERVE: 19fd, *note
     MAP_RESILIENT_CODESIGN: 1a02, *note MAP_RESILIENT_MEDIA: 1a03,
     *note MAP_TPRO: 1a07, *note MAP_TRANSLATED_ALLOW_EXECUTE: 1a05, and
     *note MAP_UNIX03: 1a06. constants.


File: python.info,  Node: Internet Data Handling,  Next: Structured Markup Processing Tools,  Prev: Networking and Interprocess Communication,  Up: The Python Standard Library

5.20 Internet Data Handling
===========================

This chapter describes modules which support handling data formats
commonly used on the internet.

* Menu:

* email — An email and MIME handling package::
* json — JSON encoder and decoder::
* mailbox — Manipulate mailboxes in various formats::
* mimetypes — Map filenames to MIME types::
* base64 — Base16, Base32, Base64, Base85 Data Encodings: base64 — Base16 Base32 Base64 Base85 Data Encodings.
* binascii — Convert between binary and ASCII::
* quopri — Encode and decode MIME quoted-printable data::


File: python.info,  Node: email — An email and MIME handling package,  Next: json — JSON encoder and decoder,  Up: Internet Data Handling

5.20.1 ‘email’ — An email and MIME handling package
---------------------------------------------------

'Source code:' Lib/email/__init__.py(1)

__________________________________________________________________

The *note email: 3f. package is a library for managing email messages.
It is specifically 'not' designed to do any sending of email messages to
SMTP ( RFC 2821(2)), NNTP, or other servers; those are functions of
modules such as *note smtplib: cf.  The *note email: 3f. package
attempts to be as RFC-compliant as possible, supporting RFC 5322(3) and
RFC 6532(4), as well as such MIME-related RFCs as RFC 2045(5), RFC
2046(6), RFC 2047(7), RFC 2183(8), and RFC 2231(9).

The overall structure of the email package can be divided into three
major components, plus a fourth component that controls the behavior of
the other components.

The central component of the package is an «object model» that
represents email messages.  An application interacts with the package
primarily through the object model interface defined in the *note
message: 48. sub-module.  The application can use this API to ask
questions about an existing email, to construct a new email, or to add
or remove email subcomponents that themselves use the same object model
interface.  That is, following the nature of email messages and their
MIME subcomponents, the email object model is a tree structure of
objects that all provide the *note EmailMessage: 580. API.

The other two major components of the package are the *note parser: 52.
and the *note generator: 44.  The parser takes the serialized version of
an email message (a stream of bytes) and converts it into a tree of
*note EmailMessage: 580. objects.  The generator takes an *note
EmailMessage: 580. and turns it back into a serialized byte stream.
(The parser and generator also handle streams of text characters, but
this usage is discouraged as it is too easy to end up with messages that
are not valid in one way or another.)

The control component is the *note policy: 53. module.  Every *note
EmailMessage: 580, every *note generator: 44, and every *note parser:
52. has an associated *note policy: 53. object that controls its
behavior.  Usually an application only needs to specify the policy when
an *note EmailMessage: 580. is created, either by directly instantiating
an *note EmailMessage: 580. to create a new email, or by parsing an
input stream using a *note parser: 52.  But the policy can be changed
when the message is serialized using a *note generator: 44.  This
allows, for example, a generic email message to be parsed from disk, but
to serialize it using standard SMTP settings when sending it to an email
server.

The email package does its best to hide the details of the various
governing RFCs from the application.  Conceptually the application
should be able to treat the email message as a structured tree of
unicode text and binary attachments, without having to worry about how
these are represented when serialized.  In practice, however, it is
often necessary to be aware of at least some of the rules governing MIME
messages and their structure, specifically the names and nature of the
MIME «content types» and how they identify multipart documents.  For the
most part this knowledge should only be required for more complex
applications, and even then it should only be the high level structure
in question, and not the details of how those structures are
represented.  Since MIME content types are used widely in modern
internet software (not just email), this will be a familiar concept to
many programmers.

The following sections describe the functionality of the *note email:
3f. package.  We start with the *note message: 48. object model, which
is the primary interface an application will use, and follow that with
the *note parser: 52. and *note generator: 44. components.  Then we
cover the *note policy: 53. controls, which completes the treatment of
the main components of the library.

The next three sections cover the exceptions the package may raise and
the defects (non-compliance with the RFCs) that the *note parser: 52.
may detect.  Then we cover the *note headerregistry: 46. and the *note
contentmanager: 41. sub-components, which provide tools for doing more
detailed manipulation of headers and payloads, respectively.  Both of
these components contain features relevant to consuming and producing
non-trivial messages, but also document their extensibility APIs, which
will be of interest to advanced applications.

Following those is a set of examples of using the fundamental parts of
the APIs covered in the preceding sections.

The foregoing represent the modern (unicode friendly) API of the email
package.  The remaining sections, starting with the *note Message: 581.
class, cover the legacy *note compat32: e99. API that deals much more
directly with the details of how email messages are represented.  The
*note compat32: e99. API does 'not' hide the details of the RFCs from
the application, but for applications that need to operate at that
level, they can be useful tools.  This documentation is also relevant
for applications that are still using the *note compat32: e99. API for
backward compatibility reasons.

Cambiato nella versione 3.6: Docs reorganized and rewritten to promote
the new *note EmailMessage: 580./*note EmailPolicy: 12bf. API.

Contents of the *note email: 3f. package documentation:

* Menu:

* email.message; Representing an email message: email message Representing an email message.
* email.parser; Parsing email messages: email parser Parsing email messages.
* email.generator; Generating MIME documents: email generator Generating MIME documents.
* email.policy; Policy Objects: email policy Policy Objects.
* email.errors; Exception and Defect classes: email errors Exception and Defect classes.
* email.headerregistry; Custom Header Objects: email headerregistry Custom Header Objects.
* email.contentmanager; Managing MIME Content: email contentmanager Managing MIME Content.
* email; Examples: email Examples.
* email.message.Message; Representing an email message using the compat32 API: email message Message Representing an email message using the compat32 API.
* email.mime; Creating email and MIME objects from scratch: email mime Creating email and MIME objects from scratch.
* email.header; Internationalized headers: email header Internationalized headers.
* email.charset; Representing character sets: email charset Representing character sets.
* email.encoders; Encoders: email encoders Encoders.
* email.utils; Miscellaneous utilities: email utils Miscellaneous utilities.
* email.iterators; Iterators: email iterators Iterators.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/email/__init__.py

   (2) https://datatracker.ietf.org/doc/html/rfc2821.html

   (3) https://datatracker.ietf.org/doc/html/rfc5322.html

   (4) https://datatracker.ietf.org/doc/html/rfc6532.html

   (5) https://datatracker.ietf.org/doc/html/rfc2045.html

   (6) https://datatracker.ietf.org/doc/html/rfc2046.html

   (7) https://datatracker.ietf.org/doc/html/rfc2047.html

   (8) https://datatracker.ietf.org/doc/html/rfc2183.html

   (9) https://datatracker.ietf.org/doc/html/rfc2231.html


File: python.info,  Node: email message Representing an email message,  Next: email parser Parsing email messages,  Up: email — An email and MIME handling package

5.20.1.1 ‘email.message’: Representing an email message
.......................................................

'Source code:' Lib/email/message.py(1)

__________________________________________________________________

Added in version 3.6: (2)

The central class in the *note email: 3f. package is the *note
EmailMessage: 580. class, imported from the *note email.message: 48.
module.  It is the base class for the *note email: 3f. object model.
*note EmailMessage: 580. provides the core functionality for setting and
querying header fields, for accessing message bodies, and for creating
or modifying structured messages.

An email message consists of 'headers' and a 'payload' (which is also
referred to as the 'content').  Headers are RFC 5322(3) or RFC 6532(4)
style field names and values, where the field name and value are
separated by a colon.  The colon is not part of either the field name or
the field value.  The payload may be a simple text message, or a binary
object, or a structured sequence of sub-messages each with their own set
of headers and their own payload.  The latter type of payload is
indicated by the message having a MIME type such as ‘multipart/*’ or
‘message/rfc822’.

The conceptual model provided by an *note EmailMessage: 580. object is
that of an ordered dictionary of headers coupled with a 'payload' that
represents the RFC 5322(5) body of the message, which might be a list of
sub-‘EmailMessage’ objects.  In addition to the normal dictionary
methods for accessing the header names and values, there are methods for
accessing specialized information from the headers (for example the MIME
content type), for operating on the payload, for generating a serialized
version of the message, and for recursively walking over the object
tree.

The *note EmailMessage: 580. dictionary-like interface is indexed by the
header names, which must be ASCII values.  The values of the dictionary
are strings with some extra methods.  Headers are stored and returned in
case-preserving form, but field names are matched case-insensitively.
The keys are ordered, but unlike a real dict, there can be duplicates.
Additional methods are provided for working with headers that have
duplicate keys.

The 'payload' is either a string or bytes object, in the case of simple
message objects, or a list of *note EmailMessage: 580. objects, for MIME
container documents such as ‘multipart/*’ and ‘message/rfc822’ message
objects.

 -- Classe: email.message.EmailMessage (policy=default)

     If 'policy' is specified use the rules it specifies to update and
     serialize the representation of the message.  If 'policy' is not
     set, use the *note default: 176d. policy, which follows the rules
     of the email RFCs except for line endings (instead of the RFC
     mandated ‘\r\n’, it uses the Python standard ‘\n’ line endings).
     For more information see the *note policy: 53. documentation.  (6)

      -- Metodo: as_string (unixfrom=False, maxheaderlen=None,
               policy=None)

          Return the entire message flattened as a string.  When
          optional 'unixfrom' is true, the envelope header is included
          in the returned string.  'unixfrom' defaults to ‘False’.  For
          backward compatibility with the base *note Message: 581. class
          'maxheaderlen' is accepted, but defaults to ‘None’, which
          means that by default the line length is controlled by the
          *note max_line_length: 3a9f. of the policy.  The 'policy'
          argument may be used to override the default policy obtained
          from the message instance.  This can be used to control some
          of the formatting produced by the method, since the specified
          'policy' will be passed to the *note Generator: 13d6.

          Flattening the message may trigger changes to the *note
          EmailMessage: 580. if defaults need to be filled in to
          complete the transformation to a string (for example, MIME
          boundaries may be generated or modified).

          Note that this method is provided as a convenience and may not
          be the most useful way to serialize messages in your
          application, especially if you are dealing with multiple
          messages.  See *note email.generator.Generator: 13d6. for a
          more flexible API for serializing messages.  Note also that
          this method is restricted to producing messages serialized as
          «7 bit clean» when *note utf8: ffb. is ‘False’, which is the
          default.

          Cambiato nella versione 3.6: the default behavior when
          'maxheaderlen' is not specified was changed from defaulting to
          0 to defaulting to the value of 'max_line_length' from the
          policy.

      -- Metodo: __str__ ()

          Equivalent to
          ‘as_string(policy=self.policy.clone(utf8=True))’.  Allows
          ‘str(msg)’ to produce a string containing the serialized
          message in a readable format.

          Cambiato nella versione 3.4: the method was changed to use
          ‘utf8=True’, thus producing an RFC 6531(7)-like message
          representation, instead of being a direct alias for *note
          as_string(): 3a9e.

      -- Metodo: as_bytes (unixfrom=False, policy=None)

          Return the entire message flattened as a bytes object.  When
          optional 'unixfrom' is true, the envelope header is included
          in the returned string.  'unixfrom' defaults to ‘False’.  The
          'policy' argument may be used to override the default policy
          obtained from the message instance.  This can be used to
          control some of the formatting produced by the method, since
          the specified 'policy' will be passed to the *note
          BytesGenerator: 13d7.

          Flattening the message may trigger changes to the *note
          EmailMessage: 580. if defaults need to be filled in to
          complete the transformation to a string (for example, MIME
          boundaries may be generated or modified).

          Note that this method is provided as a convenience and may not
          be the most useful way to serialize messages in your
          application, especially if you are dealing with multiple
          messages.  See *note email.generator.BytesGenerator: 13d7. for
          a more flexible API for serializing messages.

      -- Metodo: __bytes__ ()

          Equivalent to *note as_bytes(): 3aa1.  Allows ‘bytes(msg)’ to
          produce a bytes object containing the serialized message.

      -- Metodo: is_multipart ()

          Return ‘True’ if the message’s payload is a list of sub-*note
          EmailMessage: 580. objects, otherwise return ‘False’.  When
          *note is_multipart(): 3aa3. returns ‘False’, the payload
          should be a string object (which might be a CTE encoded binary
          payload).  Note that *note is_multipart(): 3aa3. returning
          ‘True’ does not necessarily mean that
          «msg.get_content_maintype() == “multipart”» will return the
          ‘True’.  For example, ‘is_multipart’ will return ‘True’ when
          the *note EmailMessage: 580. is of type ‘message/rfc822’.

      -- Metodo: set_unixfrom (unixfrom)

          Set the message’s envelope header to 'unixfrom', which should
          be a string.  (See *note mboxMessage: 3aa5. for a brief
          description of this header.)

      -- Metodo: get_unixfrom ()

          Return the message’s envelope header.  Defaults to ‘None’ if
          the envelope header was never set.

     The following methods implement the mapping-like interface for
     accessing the message’s headers.  Note that there are some semantic
     differences between these methods and a normal mapping (i.e.
     dictionary) interface.  For example, in a dictionary there are no
     duplicate keys, but here there may be duplicate message headers.
     Also, in dictionaries there is no guaranteed order to the keys
     returned by *note keys(): 3aa7, but in an *note EmailMessage: 580.
     object, headers are always returned in the order they appeared in
     the original message, or in which they were added to the message
     later.  Any header deleted and then re-added is always appended to
     the end of the header list.

     These semantic differences are intentional and are biased toward
     convenience in the most common use cases.

     Note that in all cases, any envelope header present in the message
     is not included in the mapping interface.

      -- Metodo: __len__ ()

          Return the total number of headers, including duplicates.

      -- Metodo: __contains__ (name)

          Return ‘True’ if the message object has a field named 'name'.
          Matching is done without regard to case and 'name' does not
          include the trailing colon.  Used for the ‘in’ operator.  For
          example:

               if 'message-id' in myMessage:
                  print('Message-ID:', myMessage['message-id'])

      -- Metodo: __getitem__ (name)

          Return the value of the named header field.  'name' does not
          include the colon field separator.  If the header is missing,
          ‘None’ is returned; a *note KeyError: 5e7. is never raised.

          Note that if the named field appears more than once in the
          message’s headers, exactly which of those field values will be
          returned is undefined.  Use the *note get_all(): 3aab. method
          to get the values of all the extant headers named 'name'.

          Using the standard (non-‘compat32’) policies, the returned
          value is an instance of a subclass of *note
          email.headerregistry.BaseHeader: 3aac.

      -- Metodo: __setitem__ (name, val)

          Add a header to the message with field name 'name' and value
          'val'.  The field is appended to the end of the message’s
          existing headers.

          Note that this does 'not' overwrite or delete any existing
          header with the same name.  If you want to ensure that the new
          header is the only one present in the message with field name
          'name', delete the field first, e.g.:

               del msg['subject']
               msg['subject'] = 'Python roolz!'

          If the *note policy: 53. defines certain headers to be unique
          (as the standard policies do), this method may raise a *note
          ValueError: 2ec. when an attempt is made to assign a value to
          such a header when one already exists.  This behavior is
          intentional for consistency’s sake, but do not depend on it as
          we may choose to make such assignments do an automatic
          deletion of the existing header in the future.

      -- Metodo: __delitem__ (name)

          Delete all occurrences of the field with name 'name' from the
          message’s headers.  No exception is raised if the named field
          isn’t present in the headers.

      -- Metodo: keys ()

          Return a list of all the message’s header field names.

      -- Metodo: values ()

          Return a list of all the message’s field values.

      -- Metodo: items ()

          Return a list of 2-tuples containing all the message’s field
          headers and values.

      -- Metodo: get (name, failobj=None)

          Return the value of the named header field.  This is identical
          to *note __getitem__(): 588. except that optional 'failobj' is
          returned if the named header is missing ('failobj' defaults to
          ‘None’).

     Here are some additional useful header related methods:

      -- Metodo: get_all (name, failobj=None)

          Return a list of all the values for the field named 'name'.
          If there are no such named headers in the message, 'failobj'
          is returned (defaults to ‘None’).

      -- Metodo: add_header (_name, _value, **_params)

          Extended header setting.  This method is similar to *note
          __setitem__(): 3aad. except that additional header parameters
          can be provided as keyword arguments.  '_name' is the header
          field to add and '_value' is the 'primary' value for the
          header.

          For each item in the keyword argument dictionary '_params',
          the key is taken as the parameter name, with underscores
          converted to dashes (since dashes are illegal in Python
          identifiers).  Normally, the parameter will be added as
          ‘key="value"’ unless the value is ‘None’, in which case only
          the key will be added.

          If the value contains non-ASCII characters, the charset and
          language may be explicitly controlled by specifying the value
          as a three tuple in the format ‘(CHARSET, LANGUAGE, VALUE)’,
          where ‘CHARSET’ is a string naming the charset to be used to
          encode the value, ‘LANGUAGE’ can usually be set to ‘None’ or
          the empty string (see RFC 2231(8) for other possibilities),
          and ‘VALUE’ is the string value containing non-ASCII code
          points.  If a three tuple is not passed and the value contains
          non-ASCII characters, it is automatically encoded in RFC
          2231(9) format using a ‘CHARSET’ of ‘utf-8’ and a ‘LANGUAGE’
          of ‘None’.

          Here is an example:

               msg.add_header('Content-Disposition', 'attachment', filename='bud.gif')

          This will add a header that looks like

               Content-Disposition: attachment; filename="bud.gif"

          An example of the extended interface with non-ASCII
          characters:

               msg.add_header('Content-Disposition', 'attachment',
                              filename=('iso-8859-1', '', 'Fußballer.ppt'))

      -- Metodo: replace_header (_name, _value)

          Replace a header.  Replace the first header found in the
          message that matches '_name', retaining header order and field
          name case of the original header.  If no matching header is
          found, raise a *note KeyError: 5e7.

      -- Metodo: get_content_type ()

          Return the message’s content type, coerced to lower case of
          the form ‘maintype/subtype’.  If there is no ‘Content-Type’
          header in the message return the value returned by *note
          get_default_type(): 3ab5.  If the ‘Content-Type’ header is
          invalid, return ‘text/plain’.

          (According to RFC 2045(10), messages always have a default
          type, *note get_content_type(): 3ab4. will always return a
          value.  RFC 2045(11) defines a message’s default type to be
          ‘text/plain’ unless it appears inside a ‘multipart/digest’
          container, in which case it would be ‘message/rfc822’.  If the
          ‘Content-Type’ header has an invalid type specification, RFC
          2045(12) mandates that the default type be ‘text/plain’.)

      -- Metodo: get_content_maintype ()

          Return the message’s main content type.  This is the
          ‘maintype’ part of the string returned by *note
          get_content_type(): 3ab4.

      -- Metodo: get_content_subtype ()

          Return the message’s sub-content type.  This is the ‘subtype’
          part of the string returned by *note get_content_type(): 3ab4.

      -- Metodo: get_default_type ()

          Return the default content type.  Most messages have a default
          content type of ‘text/plain’, except for messages that are
          subparts of ‘multipart/digest’ containers.  Such subparts have
          a default content type of ‘message/rfc822’.

      -- Metodo: set_default_type (ctype)

          Set the default content type.  'ctype' should either be
          ‘text/plain’ or ‘message/rfc822’, although this is not
          enforced.  The default content type is not stored in the
          ‘Content-Type’ header, so it only affects the return value of
          the ‘get_content_type’ methods when no ‘Content-Type’ header
          is present in the message.

      -- Metodo: set_param (param, value, header='Content-Type',
               requote=True, charset=None, language='', replace=False)

          Set a parameter in the ‘Content-Type’ header.  If the
          parameter already exists in the header, replace its value with
          'value'.  When 'header' is ‘Content-Type’ (the default) and
          the header does not yet exist in the message, add it, set its
          value to ‘text/plain’, and append the new parameter value.
          Optional 'header' specifies an alternative header to
          ‘Content-Type’.

          If the value contains non-ASCII characters, the charset and
          language may be explicitly specified using the optional
          'charset' and 'language' parameters.  Optional 'language'
          specifies the RFC 2231(13) language, defaulting to the empty
          string.  Both 'charset' and 'language' should be strings.  The
          default is to use the ‘utf8’ 'charset' and ‘None’ for the
          'language'.

          If 'replace' is ‘False’ (the default) the header is moved to
          the end of the list of headers.  If 'replace' is ‘True’, the
          header will be updated in place.

          Use of the 'requote' parameter with *note EmailMessage: 580.
          objects is deprecated.

          Note that existing parameter values of headers may be accessed
          through the *note params: 3aba. attribute of the header value
          (for example, ‘msg['Content-Type'].params['charset']’).

          Cambiato nella versione 3.4: ‘replace’ keyword was added.

      -- Metodo: del_param (param, header='content-type', requote=True)

          Remove the given parameter completely from the ‘Content-Type’
          header.  The header will be re-written in place without the
          parameter or its value.  Optional 'header' specifies an
          alternative to ‘Content-Type’.

          Use of the 'requote' parameter with *note EmailMessage: 580.
          objects is deprecated.

      -- Metodo: get_filename (failobj=None)

          Return the value of the ‘filename’ parameter of the
          ‘Content-Disposition’ header of the message.  If the header
          does not have a ‘filename’ parameter, this method falls back
          to looking for the ‘name’ parameter on the ‘Content-Type’
          header.  If neither is found, or the header is missing, then
          'failobj' is returned.  The returned string will always be
          unquoted as per *note email.utils.unquote(): 3abd.

      -- Metodo: get_boundary (failobj=None)

          Return the value of the ‘boundary’ parameter of the
          ‘Content-Type’ header of the message, or 'failobj' if either
          the header is missing, or has no ‘boundary’ parameter.  The
          returned string will always be unquoted as per *note
          email.utils.unquote(): 3abd.

      -- Metodo: set_boundary (boundary)

          Set the ‘boundary’ parameter of the ‘Content-Type’ header to
          'boundary'.  *note set_boundary(): 3abf. will always quote
          'boundary' if necessary.  A *note HeaderParseError: 3ac0. is
          raised if the message object has no ‘Content-Type’ header.

          Note that using this method is subtly different from deleting
          the old ‘Content-Type’ header and adding a new one with the
          new boundary via *note add_header(): 3ab2, because *note
          set_boundary(): 3abf. preserves the order of the
          ‘Content-Type’ header in the list of headers.

      -- Metodo: get_content_charset (failobj=None)

          Return the ‘charset’ parameter of the ‘Content-Type’ header,
          coerced to lower case.  If there is no ‘Content-Type’ header,
          or if that header has no ‘charset’ parameter, 'failobj' is
          returned.

      -- Metodo: get_charsets (failobj=None)

          Return a list containing the character set names in the
          message.  If the message is a ‘multipart’, then the list will
          contain one element for each subpart in the payload,
          otherwise, it will be a list of length 1.

          Each item in the list will be a string which is the value of
          the ‘charset’ parameter in the ‘Content-Type’ header for the
          represented subpart.  If the subpart has no ‘Content-Type’
          header, no ‘charset’ parameter, or is not of the ‘text’ main
          MIME type, then that item in the returned list will be
          'failobj'.

      -- Metodo: is_attachment ()

          Return ‘True’ if there is a ‘Content-Disposition’ header and
          its (case insensitive) value is ‘attachment’, ‘False’
          otherwise.

          Cambiato nella versione 3.4.2: is_attachment is now a method
          instead of a property, for consistency with *note
          is_multipart(): 3ac4.

      -- Metodo: get_content_disposition ()

          Return the lowercased value (without parameters) of the
          message’s ‘Content-Disposition’ header if it has one, or
          ‘None’.  The possible values for this method are 'inline',
          'attachment' or ‘None’ if the message follows RFC 2183(14).

          Added in version 3.5.

     The following methods relate to interrogating and manipulating the
     content (payload) of the message.

      -- Metodo: walk ()

          The *note walk(): 3ac6. method is an all-purpose generator
          which can be used to iterate over all the parts and subparts
          of a message object tree, in depth-first traversal order.  You
          will typically use *note walk(): 3ac6. as the iterator in a
          ‘for’ loop; each iteration returns the next subpart.

          Here’s an example that prints the MIME type of every part of a
          multipart message structure:

               >>> for part in msg.walk():
               ...     print(part.get_content_type())
               multipart/report
               text/plain
               message/delivery-status
               text/plain
               text/plain
               message/rfc822
               text/plain

          ‘walk’ iterates over the subparts of any part where *note
          is_multipart(): 3aa3. returns ‘True’, even though
          ‘msg.get_content_maintype() == 'multipart'’ may return
          ‘False’.  We can see this in our example by making use of the
          ‘_structure’ debug helper function:

               >>> from email.iterators import _structure
               >>> for part in msg.walk():
               ...     print(part.get_content_maintype() == 'multipart',
               ...           part.is_multipart())
               True True
               False False
               False True
               False False
               False False
               False True
               False False
               >>> _structure(msg)
               multipart/report
                   text/plain
                   message/delivery-status
                       text/plain
                       text/plain
                   message/rfc822
                       text/plain

          Here the ‘message’ parts are not ‘multiparts’, but they do
          contain subparts.  ‘is_multipart()’ returns ‘True’ and ‘walk’
          descends into the subparts.

      -- Metodo: get_body (preferencelist=('related', 'html', 'plain'))

          Return the MIME part that is the best candidate to be the
          «body» of the message.

          'preferencelist' must be a sequence of strings from the set
          ‘related’, ‘html’, and ‘plain’, and indicates the order of
          preference for the content type of the part returned.

          Start looking for candidate matches with the object on which
          the ‘get_body’ method is called.

          If ‘related’ is not included in 'preferencelist', consider the
          root part (or subpart of the root part) of any related
          encountered as a candidate if the (sub-)part matches a
          preference.

          When encountering a ‘multipart/related’, check the ‘start’
          parameter and if a part with a matching ‘Content-ID’ is found,
          consider only it when looking for candidate matches.
          Otherwise consider only the first (default root) part of the
          ‘multipart/related’.

          If a part has a ‘Content-Disposition’ header, only consider
          the part a candidate match if the value of the header is
          ‘inline’.

          If none of the candidates matches any of the preferences in
          'preferencelist', return ‘None’.

          Notes: (1) For most applications the only 'preferencelist'
          combinations that really make sense are ‘('plain',)’,
          ‘('html', 'plain')’, and the default ‘('related', 'html',
          'plain')’.  (2) Because matching starts with the object on
          which ‘get_body’ is called, calling ‘get_body’ on a
          ‘multipart/related’ will return the object itself unless
          'preferencelist' has a non-default value.  (3) Messages (or
          message parts) that do not specify a ‘Content-Type’ or whose
          ‘Content-Type’ header is invalid will be treated as if they
          are of type ‘text/plain’, which may occasionally cause
          ‘get_body’ to return unexpected results.

      -- Metodo: iter_attachments ()

          Return an iterator over all of the immediate sub-parts of the
          message that are not candidate «body» parts.  That is, skip
          the first occurrence of each of ‘text/plain’, ‘text/html’,
          ‘multipart/related’, or ‘multipart/alternative’ (unless they
          are explicitly marked as attachments via ‘Content-Disposition:
          attachment’), and return all remaining parts.  When applied
          directly to a ‘multipart/related’, return an iterator over the
          all the related parts except the root part (ie: the part
          pointed to by the ‘start’ parameter, or the first part if
          there is no ‘start’ parameter or the ‘start’ parameter doesn’t
          match the ‘Content-ID’ of any of the parts).  When applied
          directly to a ‘multipart/alternative’ or a non-‘multipart’,
          return an empty iterator.

      -- Metodo: iter_parts ()

          Return an iterator over all of the immediate sub-parts of the
          message, which will be empty for a non-‘multipart’.  (See also
          *note walk(): 3ac6.)

      -- Metodo: get_content (*args, content_manager=None, **kw)

          Call the *note get_content(): 3acb. method of the
          'content_manager', passing self as the message object, and
          passing along any other arguments or keywords as additional
          arguments.  If 'content_manager' is not specified, use the
          ‘content_manager’ specified by the current *note policy: 53.

      -- Metodo: set_content (*args, content_manager=None, **kw)

          Call the *note set_content(): 3acc. method of the
          'content_manager', passing self as the message object, and
          passing along any other arguments or keywords as additional
          arguments.  If 'content_manager' is not specified, use the
          ‘content_manager’ specified by the current *note policy: 53.

      -- Metodo: make_related (boundary=None)

          Convert a non-‘multipart’ message into a ‘multipart/related’
          message, moving any existing ‘Content-’ headers and payload
          into a (new) first part of the ‘multipart’.  If 'boundary' is
          specified, use it as the boundary string in the multipart,
          otherwise leave the boundary to be automatically created when
          it is needed (for example, when the message is serialized).

      -- Metodo: make_alternative (boundary=None)

          Convert a non-‘multipart’ or a ‘multipart/related’ into a
          ‘multipart/alternative’, moving any existing ‘Content-’
          headers and payload into a (new) first part of the
          ‘multipart’.  If 'boundary' is specified, use it as the
          boundary string in the multipart, otherwise leave the boundary
          to be automatically created when it is needed (for example,
          when the message is serialized).

      -- Metodo: make_mixed (boundary=None)

          Convert a non-‘multipart’, a ‘multipart/related’, or a
          ‘multipart-alternative’ into a ‘multipart/mixed’, moving any
          existing ‘Content-’ headers and payload into a (new) first
          part of the ‘multipart’.  If 'boundary' is specified, use it
          as the boundary string in the multipart, otherwise leave the
          boundary to be automatically created when it is needed (for
          example, when the message is serialized).

      -- Metodo: add_related (*args, content_manager=None, **kw)

          If the message is a ‘multipart/related’, create a new message
          object, pass all of the arguments to its *note set_content():
          1c45. method, and *note attach(): 3ad1. it to the ‘multipart’.
          If the message is a non-‘multipart’, call *note
          make_related(): 3acd. and then proceed as above.  If the
          message is any other type of ‘multipart’, raise a *note
          TypeError: 198.  If 'content_manager' is not specified, use
          the ‘content_manager’ specified by the current *note policy:
          53.  If the added part has no ‘Content-Disposition’ header,
          add one with the value ‘inline’.

      -- Metodo: add_alternative (*args, content_manager=None, **kw)

          If the message is a ‘multipart/alternative’, create a new
          message object, pass all of the arguments to its *note
          set_content(): 1c45. method, and *note attach(): 3ad1. it to
          the ‘multipart’.  If the message is a non-‘multipart’ or
          ‘multipart/related’, call *note make_alternative(): 3ace. and
          then proceed as above.  If the message is any other type of
          ‘multipart’, raise a *note TypeError: 198.  If
          'content_manager' is not specified, use the ‘content_manager’
          specified by the current *note policy: 53.

      -- Metodo: add_attachment (*args, content_manager=None, **kw)

          If the message is a ‘multipart/mixed’, create a new message
          object, pass all of the arguments to its *note set_content():
          1c45. method, and *note attach(): 3ad1. it to the ‘multipart’.
          If the message is a non-‘multipart’, ‘multipart/related’, or
          ‘multipart/alternative’, call *note make_mixed(): 3acf. and
          then proceed as above.  If 'content_manager' is not specified,
          use the ‘content_manager’ specified by the current *note
          policy: 53.  If the added part has no ‘Content-Disposition’
          header, add one with the value ‘attachment’.  This method can
          be used both for explicit attachments (‘Content-Disposition:
          attachment’) and ‘inline’ attachments (‘Content-Disposition:
          inline’), by passing appropriate options to the
          ‘content_manager’.

      -- Metodo: clear ()

          Remove the payload and all of the headers.

      -- Metodo: clear_content ()

          Remove the payload and all of the ‘!Content-’ headers, leaving
          all other headers intact and in their original order.

     *note EmailMessage: 580. objects have the following instance
     attributes:

      -- Attributo: preamble

          The format of a MIME document allows for some text between the
          blank line following the headers, and the first multipart
          boundary string.  Normally, this text is never visible in a
          MIME-aware mail reader because it falls outside the standard
          MIME armor.  However, when viewing the raw text of the
          message, or when viewing the message in a non-MIME aware
          reader, this text can become visible.

          The 'preamble' attribute contains this leading extra-armor
          text for MIME documents.  When the *note Parser: 13a5.
          discovers some text after the headers but before the first
          boundary string, it assigns this text to the message’s
          'preamble' attribute.  When the *note Generator: 13d6. is
          writing out the plain text representation of a MIME message,
          and it finds the message has a 'preamble' attribute, it will
          write this text in the area between the headers and the first
          boundary.  See *note email.parser: 52. and *note
          email.generator: 44. for details.

          Note that if the message object has no preamble, the
          'preamble' attribute will be ‘None’.

      -- Attributo: epilogue

          The 'epilogue' attribute acts the same way as the 'preamble'
          attribute, except that it contains text that appears between
          the last boundary and the end of the message.  As with the
          *note preamble: 3ad6, if there is no epilog text this
          attribute will be ‘None’.

      -- Attributo: defects

          The 'defects' attribute contains a list of all the problems
          found when parsing this message.  See *note email.errors: 43.
          for a detailed description of the possible parsing defects.

 -- Classe: email.message.MIMEPart (policy=default)

     This class represents a subpart of a MIME message.  It is identical
     to *note EmailMessage: 580, except that no ‘MIME-Version’ headers
     are added when *note set_content(): 1c45. is called, since
     sub-parts do not need their own ‘MIME-Version’ headers.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/email/message.py

   (2) Originally added in 3.4 as a *note provisional module: 1244.
Docs for legacy message class moved to *note email.message.Message;
Representing an email message using the compat32 API: 3a9d.

   (3) https://datatracker.ietf.org/doc/html/rfc5322.html

   (4) https://datatracker.ietf.org/doc/html/rfc6532.html

   (5) https://datatracker.ietf.org/doc/html/rfc5322.html

   (6) The *note EmailMessage: 580. class requires a policy that
provides a ‘content_manager’ attribute for content management methods
like ‘set_content()’ and ‘get_content()’ to work.  The legacy *note
compat32: e99. policy does not support these methods and should not be
used with *note EmailMessage: 580.

   (7) https://datatracker.ietf.org/doc/html/rfc6531.html

   (8) https://datatracker.ietf.org/doc/html/rfc2231.html

   (9) https://datatracker.ietf.org/doc/html/rfc2231.html

   (10) https://datatracker.ietf.org/doc/html/rfc2045.html

   (11) https://datatracker.ietf.org/doc/html/rfc2045.html

   (12) https://datatracker.ietf.org/doc/html/rfc2045.html

   (13) https://datatracker.ietf.org/doc/html/rfc2231.html

   (14) https://datatracker.ietf.org/doc/html/rfc2183.html


File: python.info,  Node: email parser Parsing email messages,  Next: email generator Generating MIME documents,  Prev: email message Representing an email message,  Up: email — An email and MIME handling package

5.20.1.2 ‘email.parser’: Parsing email messages
...............................................

'Source code:' Lib/email/parser.py(1)

__________________________________________________________________

Message object structures can be created in one of two ways: they can be
created from whole cloth by creating an *note EmailMessage: 580. object,
adding headers using the dictionary interface, and adding payload(s)
using *note set_content(): 1c45. and related methods, or they can be
created by parsing a serialized representation of the email message.

The *note email: 3f. package provides a standard parser that understands
most email document structures, including MIME documents.  You can pass
the parser a bytes, string or file object, and the parser will return to
you the root *note EmailMessage: 580. instance of the object structure.
For simple, non-MIME messages the payload of this root object will
likely be a string containing the text of the message.  For MIME
messages, the root object will return ‘True’ from its *note
is_multipart(): 3aa3. method, and the subparts can be accessed via the
payload manipulation methods, such as *note get_body(): 3ac7, *note
iter_parts(): 3ac9, and *note walk(): 3ac6.

There are actually two parser interfaces available for use, the *note
Parser: 13a5. API and the incremental *note FeedParser: 176c. API. The
*note Parser: 13a5. API is most useful if you have the entire text of
the message in memory, or if the entire message lives in a file on the
file system.  *note FeedParser: 176c. is more appropriate when you are
reading the message from a stream which might block waiting for more
input (such as reading an email message from a socket).  The *note
FeedParser: 176c. can consume and parse the message incrementally, and
only returns the root object when you close the parser.

Note that the parser can be extended in limited ways, and of course you
can implement your own parser completely from scratch.  All of the logic
that connects the *note email: 3f. package’s bundled parser and the
*note EmailMessage: 580. class is embodied in the *note Policy: 12bb.
class, so a custom parser can create message object trees any way it
finds necessary by implementing custom versions of the appropriate
‘Policy’ methods.

* Menu:

* FeedParser API::
* Parser API::
* Additional notes::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/email/parser.py


File: python.info,  Node: FeedParser API,  Next: Parser API,  Up: email parser Parsing email messages

5.20.1.3 FeedParser API
.......................

The *note BytesFeedParser: 13d3, imported from the ‘email.feedparser’
module, provides an API that is conducive to incremental parsing of
email messages, such as would be necessary when reading the text of an
email message from a source that can block (such as a socket).  The
*note BytesFeedParser: 13d3. can of course be used to parse an email
message fully contained in a *note bytes-like object: 193, string, or
file, but the *note BytesParser: 13d4. API may be more convenient for
such use cases.  The semantics and results of the two parser APIs are
identical.

The *note BytesFeedParser: 13d3.’s API is simple; you create an
instance, feed it a bunch of bytes until there’s no more to feed it,
then close the parser to retrieve the root message object.  The *note
BytesFeedParser: 13d3. is extremely accurate when parsing
standards-compliant messages, and it does a very good job of parsing
non-compliant messages, providing information about how a message was
deemed broken.  It will populate a message object’s *note defects: 3ad8.
attribute with a list of any problems it found in a message.  See the
*note email.errors: 43. module for the list of defects that it can find.

Here is the API for the *note BytesFeedParser: 13d3.:

 -- Classe: email.parser.BytesFeedParser (_factory=None, *,
          policy=policy.compat32)

     Create a *note BytesFeedParser: 13d3. instance.  Optional
     '_factory' is a no-argument callable; if not specified use the
     *note message_factory: e98. from the 'policy'.  Call '_factory'
     whenever a new message object is needed.

     If 'policy' is specified use the rules it specifies to update the
     representation of the message.  If 'policy' is not set, use the
     *note compat32: 12bc. policy, which maintains backward
     compatibility with the Python 3.2 version of the email package and
     provides *note Message: 581. as the default factory.  All other
     policies provide *note EmailMessage: 580. as the default
     '_factory'.  For more information on what else 'policy' controls,
     see the *note policy: 53. documentation.

     Note: 'The policy keyword should always be specified'; The default
     will change to *note email.policy.default: 176d. in a future
     version of Python.

     Added in version 3.2.

     Cambiato nella versione 3.3: Added the 'policy' keyword.

     Cambiato nella versione 3.6: '_factory' defaults to the policy
     ‘message_factory’.

      -- Metodo: feed (data)

          Feed the parser some more data.  'data' should be a *note
          bytes-like object: 193. containing one or more lines.  The
          lines can be partial and the parser will stitch such partial
          lines together properly.  The lines can have any of the three
          common line endings: carriage return, newline, or carriage
          return and newline (they can even be mixed).

      -- Metodo: close ()

          Complete the parsing of all previously fed data and return the
          root message object.  It is undefined what happens if *note
          feed(): 3add. is called after this method has been called.

 -- Classe: email.parser.FeedParser (_factory=None, *,
          policy=policy.compat32)

     Works like *note BytesFeedParser: 13d3. except that the input to
     the *note feed(): 3add. method must be a string.  This is of
     limited utility, since the only way for such a message to be valid
     is for it to contain only ASCII text or, if *note utf8: ffb. is
     ‘True’, no binary attachments.

     Cambiato nella versione 3.3: Added the 'policy' keyword.


File: python.info,  Node: Parser API,  Next: Additional notes,  Prev: FeedParser API,  Up: email parser Parsing email messages

5.20.1.4 Parser API
...................

The *note BytesParser: 13d4. class, imported from the *note
email.parser: 52. module, provides an API that can be used to parse a
message when the complete contents of the message are available in a
*note bytes-like object: 193. or file.  The *note email.parser: 52.
module also provides *note Parser: 13a5. for parsing strings, and
header-only parsers, *note BytesHeaderParser: 12c3. and *note
HeaderParser: 12c4, which can be used if you’re only interested in the
headers of the message.  *note BytesHeaderParser: 12c3. and *note
HeaderParser: 12c4. can be much faster in these situations, since they
do not attempt to parse the message body, instead setting the payload to
the raw body.

 -- Classe: email.parser.BytesParser (_class=None, *,
          policy=policy.compat32)

     Create a *note BytesParser: 13d4. instance.  The '_class' and
     'policy' arguments have the same meaning and semantics as the
     '_factory' and 'policy' arguments of *note BytesFeedParser: 13d3.

     Note: 'The policy keyword should always be specified'; The default
     will change to *note email.policy.default: 176d. in a future
     version of Python.

     Cambiato nella versione 3.3: Removed the 'strict' argument that was
     deprecated in 2.4.  Added the 'policy' keyword.

     Cambiato nella versione 3.6: '_class' defaults to the policy
     ‘message_factory’.

      -- Metodo: parse (fp, headersonly=False)

          Read all the data from the binary file-like object 'fp', parse
          the resulting bytes, and return the message object.  'fp' must
          support both the *note readline(): 1531. and the ‘read()’
          methods.

          The bytes contained in 'fp' must be formatted as a block of
          RFC 5322(1) (or, if *note utf8: ffb. is ‘True’, RFC 6532(2))
          style headers and header continuation lines, optionally
          preceded by an envelope header.  The header block is
          terminated either by the end of the data or by a blank line.
          Following the header block is the body of the message (which
          may contain MIME-encoded subparts, including subparts with a
          ‘Content-Transfer-Encoding’ of ‘8bit’).

          Optional 'headersonly' is a flag specifying whether to stop
          parsing after reading the headers or not.  The default is
          ‘False’, meaning it parses the entire contents of the file.

      -- Metodo: parsebytes (bytes, headersonly=False)

          Similar to the *note parse(): 3ae0. method, except it takes a
          *note bytes-like object: 193. instead of a file-like object.
          Calling this method on a *note bytes-like object: 193. is
          equivalent to wrapping 'bytes' in a *note BytesIO: 10a6.
          instance first and calling *note parse(): 3ae0.

          Optional 'headersonly' is as with the *note parse(): 3ae0.
          method.

     Added in version 3.2.

 -- Classe: email.parser.BytesHeaderParser (_class=None, *,
          policy=policy.compat32)

     Exactly like *note BytesParser: 13d4, except that 'headersonly'
     defaults to ‘True’.

     Added in version 3.3.

 -- Classe: email.parser.Parser (_class=None, *, policy=policy.compat32)

     This class is parallel to *note BytesParser: 13d4, but handles
     string input.

     Cambiato nella versione 3.3: Removed the 'strict' argument.  Added
     the 'policy' keyword.

     Cambiato nella versione 3.6: '_class' defaults to the policy
     ‘message_factory’.

      -- Metodo: parse (fp, headersonly=False)

          Read all the data from the text-mode file-like object 'fp',
          parse the resulting text, and return the root message object.
          'fp' must support both the *note readline(): 2090. and the
          *note read(): 2056. methods on file-like objects.

          Other than the text mode requirement, this method operates
          like *note BytesParser.parse(): 3ae0.

      -- Metodo: parsestr (text, headersonly=False)

          Similar to the *note parse(): 3ae2. method, except it takes a
          string object instead of a file-like object.  Calling this
          method on a string is equivalent to wrapping 'text' in a *note
          StringIO: 112b. instance first and calling *note parse():
          3ae2.

          Optional 'headersonly' is as with the *note parse(): 3ae2.
          method.

 -- Classe: email.parser.HeaderParser (_class=None, *,
          policy=policy.compat32)

     Exactly like *note Parser: 13a5, except that 'headersonly' defaults
     to ‘True’.

Since creating a message object structure from a string or a file object
is such a common task, four functions are provided as a convenience.
They are available in the top-level *note email: 3f. package namespace.

 -- Funzione: email.message_from_bytes (s, _class=None, *,
          policy=policy.compat32)

     Return a message object structure from a *note bytes-like object:
     193.  This is equivalent to ‘BytesParser().parsebytes(s)’.
     Optional '_class' and 'policy' are interpreted as with the *note
     BytesParser: 13d4. class constructor.

     Added in version 3.2.

     Cambiato nella versione 3.3: Removed the 'strict' argument.  Added
     the 'policy' keyword.

 -- Funzione: email.message_from_binary_file (fp, _class=None, *,
          policy=policy.compat32)

     Return a message object structure tree from an open binary *note
     file object: 13cb.  This is equivalent to
     ‘BytesParser().parse(fp)’.  '_class' and 'policy' are interpreted
     as with the *note BytesParser: 13d4. class constructor.

     Added in version 3.2.

     Cambiato nella versione 3.3: Removed the 'strict' argument.  Added
     the 'policy' keyword.

 -- Funzione: email.message_from_string (s, _class=None, *,
          policy=policy.compat32)

     Return a message object structure from a string.  This is
     equivalent to ‘Parser().parsestr(s)’.  '_class' and 'policy' are
     interpreted as with the *note Parser: 13a5. class constructor.

     Cambiato nella versione 3.3: Removed the 'strict' argument.  Added
     the 'policy' keyword.

 -- Funzione: email.message_from_file (fp, _class=None, *,
          policy=policy.compat32)

     Return a message object structure tree from an open *note file
     object: 13cb.  This is equivalent to ‘Parser().parse(fp)’.
     '_class' and 'policy' are interpreted as with the *note Parser:
     13a5. class constructor.

     Cambiato nella versione 3.3: Removed the 'strict' argument.  Added
     the 'policy' keyword.

     Cambiato nella versione 3.6: '_class' defaults to the policy
     ‘message_factory’.

Here’s an example of how you might use *note message_from_bytes(): 13d1.
at an interactive Python prompt:

     >>> import email
     >>> msg = email.message_from_bytes(myBytes)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc5322.html

   (2) https://datatracker.ietf.org/doc/html/rfc6532.html


File: python.info,  Node: Additional notes,  Prev: Parser API,  Up: email parser Parsing email messages

5.20.1.5 Additional notes
.........................

Here are some notes on the parsing semantics:

   * Most non-‘multipart’ type messages are parsed as a single message
     object with a string payload.  These objects will return ‘False’
     for *note is_multipart(): 3aa3, and *note iter_parts(): 3ac9. will
     yield an empty list.

   * All ‘multipart’ type messages will be parsed as a container message
     object with a list of sub-message objects for their payload.  The
     outer container message will return ‘True’ for *note
     is_multipart(): 3aa3, and *note iter_parts(): 3ac9. will yield a
     list of subparts.

   * Most messages with a content type of ‘message/*’ (such as
     ‘message/delivery-status’ and ‘message/rfc822’) will also be parsed
     as container object containing a list payload of length 1.  Their
     *note is_multipart(): 3aa3. method will return ‘True’.  The single
     element yielded by *note iter_parts(): 3ac9. will be a sub-message
     object.

   * Some non-standards-compliant messages may not be internally
     consistent about their ‘multipart’-edness.  Such messages may have
     a ‘Content-Type’ header of type ‘multipart’, but their *note
     is_multipart(): 3aa3. method may return ‘False’.  If such messages
     were parsed with the *note FeedParser: 176c, they will have an
     instance of the *note MultipartInvariantViolationDefect: 3ae7.
     class in their 'defects' attribute list.  See *note email.errors:
     43. for details.


File: python.info,  Node: email generator Generating MIME documents,  Next: email policy Policy Objects,  Prev: email parser Parsing email messages,  Up: email — An email and MIME handling package

5.20.1.6 ‘email.generator’: Generating MIME documents
.....................................................

'Source code:' Lib/email/generator.py(1)

__________________________________________________________________

One of the most common tasks is to generate the flat (serialized)
version of the email message represented by a message object structure.
You will need to do this if you want to send your message via *note
smtplib.SMTP.sendmail(): 105b, or print the message on the console.
Taking a message object structure and producing a serialized
representation is the job of the generator classes.

As with the *note email.parser: 52. module, you aren’t limited to the
functionality of the bundled generator; you could write one from scratch
yourself.  However the bundled generator knows how to generate most
email in a standards-compliant way, should handle MIME and non-MIME
email messages just fine, and is designed so that the bytes-oriented
parsing and generation operations are inverses, assuming the same
non-transforming *note policy: 53. is used for both.  That is, parsing
the serialized byte stream via the *note BytesParser: 13d4. class and
then regenerating the serialized byte stream using *note BytesGenerator:
13d7. should produce output identical to the input (2).  (On the other
hand, using the generator on an *note EmailMessage: 580. constructed by
program may result in changes to the *note EmailMessage: 580. object as
defaults are filled in.)

The *note Generator: 13d6. class can be used to flatten a message into a
text (as opposed to binary) serialized representation, but since Unicode
cannot represent binary data directly, the message is of necessity
transformed into something that contains only ASCII characters, using
the standard email RFC Content Transfer Encoding techniques for encoding
email messages for transport over channels that are not «8 bit clean».

To accommodate reproducible processing of SMIME-signed messages *note
Generator: 13d6. disables header folding for message parts of type
‘multipart/signed’ and all subparts.

 -- Classe: email.generator.BytesGenerator (outfp, mangle_from_=None,
          maxheaderlen=None, *, policy=None)

     Return a *note BytesGenerator: 13d7. object that will write any
     message provided to the *note flatten(): 3aec. method, or any
     surrogateescape encoded text provided to the *note write(): 3aed.
     method, to the *note file-like object: 1794. 'outfp'.  'outfp' must
     support a ‘write’ method that accepts binary data.

     If optional 'mangle_from_' is ‘True’, put a ‘>’ character in front
     of any line in the body that starts with the exact string ‘"From
     "’, that is ‘From’ followed by a space at the beginning of a line.
     'mangle_from_' defaults to the value of the *note mangle_from_:
     ff9. setting of the 'policy' (which is ‘True’ for the *note
     compat32: e99. policy and ‘False’ for all others).  'mangle_from_'
     is intended for use when messages are stored in Unix mbox format
     (see *note mailbox: 8f. and WHY THE CONTENT-LENGTH FORMAT IS
     BAD(3)).

     If 'maxheaderlen' is not ‘None’, refold any header lines that are
     longer than 'maxheaderlen', or if ‘0’, do not rewrap any headers.
     If 'manheaderlen' is ‘None’ (the default), wrap headers and other
     message lines according to the 'policy' settings.

     If 'policy' is specified, use that policy to control message
     generation.  If 'policy' is ‘None’ (the default), use the policy
     associated with the *note Message: 581. or *note EmailMessage: 580.
     object passed to ‘flatten’ to control the message generation.  See
     *note email.policy: 53. for details on what 'policy' controls.

     Added in version 3.2.

     Cambiato nella versione 3.3: Added the 'policy' keyword.

     Cambiato nella versione 3.6: The default behavior of the
     'mangle_from_' and 'maxheaderlen' parameters is to follow the
     policy.

      -- Metodo: flatten (msg, unixfrom=False, linesep=None)

          Print the textual representation of the message object
          structure rooted at 'msg' to the output file specified when
          the *note BytesGenerator: 13d7. instance was created.

          If the *note policy: 53. option *note cte_type: 3aee. is
          ‘8bit’ (the default), copy any headers in the original parsed
          message that have not been modified to the output with any
          bytes with the high bit set reproduced as in the original, and
          preserve the non-ASCII ‘Content-Transfer-Encoding’ of any body
          parts that have them.  If ‘cte_type’ is ‘7bit’, convert the
          bytes with the high bit set as needed using an
          ASCII-compatible ‘Content-Transfer-Encoding’.  That is,
          transform parts with non-ASCII ‘Content-Transfer-Encoding’
          (‘Content-Transfer-Encoding: 8bit’) to an ASCII compatible
          ‘Content-Transfer-Encoding’, and encode RFC-invalid non-ASCII
          bytes in headers using the MIME ‘unknown-8bit’ character set,
          thus rendering them RFC-compliant.

          If 'unixfrom' is ‘True’, print the envelope header delimiter
          used by the Unix mailbox format (see *note mailbox: 8f.)
          before the first of the RFC 5322(4) headers of the root
          message object.  If the root object has no envelope header,
          craft a standard one.  The default is ‘False’.  Note that for
          subparts, no envelope header is ever printed.

          If 'linesep' is not ‘None’, use it as the separator character
          between all the lines of the flattened message.  If 'linesep'
          is ‘None’ (the default), use the value specified in the
          'policy'.

      -- Metodo: clone (fp)

          Return an independent clone of this *note BytesGenerator:
          13d7. instance with the exact same option settings, and 'fp'
          as the new 'outfp'.

      -- Metodo: write (s)

          Encode 's' using the ‘ASCII’ codec and the ‘surrogateescape’
          error handler, and pass it to the 'write' method of the
          'outfp' passed to the *note BytesGenerator: 13d7.’s
          constructor.

As a convenience, *note EmailMessage: 580. provides the methods *note
as_bytes(): 3aa1. and ‘bytes(aMessage)’ (a.k.a.  *note __bytes__():
3aa2.), which simplify the generation of a serialized binary
representation of a message object.  For more detail, see *note
email.message: 48.

Because strings cannot represent binary data, the *note Generator: 13d6.
class must convert any binary data in any message it flattens to an
ASCII compatible format, by converting them to an ASCII compatible
‘Content-Transfer_Encoding’.  Using the terminology of the email RFCs,
you can think of this as *note Generator: 13d6. serializing to an I/O
stream that is not «8 bit clean».  In other words, most applications
will want to be using *note BytesGenerator: 13d7, and not *note
Generator: 13d6.

 -- Classe: email.generator.Generator (outfp, mangle_from_=None,
          maxheaderlen=None, *, policy=None)

     Return a *note Generator: 13d6. object that will write any message
     provided to the *note flatten(): 3af0. method, or any text provided
     to the *note write(): 3af1. method, to the *note file-like object:
     1794. 'outfp'.  'outfp' must support a ‘write’ method that accepts
     string data.

     If optional 'mangle_from_' is ‘True’, put a ‘>’ character in front
     of any line in the body that starts with the exact string ‘"From
     "’, that is ‘From’ followed by a space at the beginning of a line.
     'mangle_from_' defaults to the value of the *note mangle_from_:
     ff9. setting of the 'policy' (which is ‘True’ for the *note
     compat32: e99. policy and ‘False’ for all others).  'mangle_from_'
     is intended for use when messages are stored in Unix mbox format
     (see *note mailbox: 8f. and WHY THE CONTENT-LENGTH FORMAT IS
     BAD(5)).

     If 'maxheaderlen' is not ‘None’, refold any header lines that are
     longer than 'maxheaderlen', or if ‘0’, do not rewrap any headers.
     If 'manheaderlen' is ‘None’ (the default), wrap headers and other
     message lines according to the 'policy' settings.

     If 'policy' is specified, use that policy to control message
     generation.  If 'policy' is ‘None’ (the default), use the policy
     associated with the *note Message: 581. or *note EmailMessage: 580.
     object passed to ‘flatten’ to control the message generation.  See
     *note email.policy: 53. for details on what 'policy' controls.

     Cambiato nella versione 3.3: Added the 'policy' keyword.

     Cambiato nella versione 3.6: The default behavior of the
     'mangle_from_' and 'maxheaderlen' parameters is to follow the
     policy.

      -- Metodo: flatten (msg, unixfrom=False, linesep=None)

          Print the textual representation of the message object
          structure rooted at 'msg' to the output file specified when
          the *note Generator: 13d6. instance was created.

          If the *note policy: 53. option *note cte_type: 3aee. is
          ‘8bit’, generate the message as if the option were set to
          ‘7bit’.  (This is required because strings cannot represent
          non-ASCII bytes.)  Convert any bytes with the high bit set as
          needed using an ASCII-compatible ‘Content-Transfer-Encoding’.
          That is, transform parts with non-ASCII
          ‘Content-Transfer-Encoding’ (‘Content-Transfer-Encoding:
          8bit’) to an ASCII compatible ‘Content-Transfer-Encoding’, and
          encode RFC-invalid non-ASCII bytes in headers using the MIME
          ‘unknown-8bit’ character set, thus rendering them
          RFC-compliant.

          If 'unixfrom' is ‘True’, print the envelope header delimiter
          used by the Unix mailbox format (see *note mailbox: 8f.)
          before the first of the RFC 5322(6) headers of the root
          message object.  If the root object has no envelope header,
          craft a standard one.  The default is ‘False’.  Note that for
          subparts, no envelope header is ever printed.

          If 'linesep' is not ‘None’, use it as the separator character
          between all the lines of the flattened message.  If 'linesep'
          is ‘None’ (the default), use the value specified in the
          'policy'.

          Cambiato nella versione 3.2: Added support for re-encoding
          ‘8bit’ message bodies, and the 'linesep' argument.

      -- Metodo: clone (fp)

          Return an independent clone of this *note Generator: 13d6.
          instance with the exact same options, and 'fp' as the new
          'outfp'.

      -- Metodo: write (s)

          Write 's' to the 'write' method of the 'outfp' passed to the
          *note Generator: 13d6.’s constructor.  This provides just
          enough file-like API for *note Generator: 13d6. instances to
          be used in the *note print(): 1177. function.

As a convenience, *note EmailMessage: 580. provides the methods *note
as_string(): 3a9e. and ‘str(aMessage)’ (a.k.a.  *note __str__(): 3aa0.),
which simplify the generation of a formatted string representation of a
message object.  For more detail, see *note email.message: 48.

The *note email.generator: 44. module also provides a derived class,
*note DecodedGenerator: e97, which is like the *note Generator: 13d6.
base class, except that non-‘text’ parts are not serialized, but are
instead represented in the output stream by a string derived from a
template filled in with information about the part.

 -- Classe: email.generator.DecodedGenerator (outfp, mangle_from_=None,
          maxheaderlen=None, fmt=None, *, policy=None)

     Act like *note Generator: 13d6, except that for any subpart of the
     message passed to *note Generator.flatten(): 3af0, if the subpart
     is of main type ‘text’, print the decoded payload of the subpart,
     and if the main type is not ‘text’, instead of printing it fill in
     the string 'fmt' using information from the part and print the
     resulting filled-in string.

     To fill in 'fmt', execute ‘fmt % part_info’, where ‘part_info’ is a
     dictionary composed of the following keys and values:

        * ‘type’ – Full MIME type of the non-‘text’ part

        * ‘maintype’ – Main MIME type of the non-‘text’ part

        * ‘subtype’ – Sub-MIME type of the non-‘text’ part

        * ‘filename’ – Filename of the non-‘text’ part

        * ‘description’ – Description associated with the non-‘text’
          part

        * ‘encoding’ – Content transfer encoding of the non-‘text’ part

     If 'fmt' is ‘None’, use the following default 'fmt':

          «[Non-text (%(type)s) part of message omitted, filename
          %(filename)s]»

     Optional '_mangle_from_' and 'maxheaderlen' are as with the *note
     Generator: 13d6. base class.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/email/generator.py

   (2) This statement assumes that you use the appropriate setting for
‘unixfrom’, and that there are no *note email.policy: 53. settings
calling for automatic adjustments (for example, *note refold_source:
3aeb. must be ‘none’, which is 'not' the default).  It is also not 100%
true, since if the message does not conform to the RFC standards
occasionally information about the exact original text is lost during
parsing error recovery.  It is a goal to fix these latter edge cases
when possible.

   (3) https://www.jwz.org/doc/content-length.html

   (4) https://datatracker.ietf.org/doc/html/rfc5322.html

   (5) https://www.jwz.org/doc/content-length.html

   (6) https://datatracker.ietf.org/doc/html/rfc5322.html


File: python.info,  Node: email policy Policy Objects,  Next: email errors Exception and Defect classes,  Prev: email generator Generating MIME documents,  Up: email — An email and MIME handling package

5.20.1.7 ‘email.policy’: Policy Objects
.......................................

Added in version 3.3.

'Source code:' Lib/email/policy.py(1)

__________________________________________________________________

The *note email: 3f. package’s prime focus is the handling of email
messages as described by the various email and MIME RFCs.  However, the
general format of email messages (a block of header fields each
consisting of a name followed by a colon followed by a value, the whole
block followed by a blank line and an arbitrary “body”), is a format
that has found utility outside of the realm of email.  Some of these
uses conform fairly closely to the main email RFCs, some do not.  Even
when working with email, there are times when it is desirable to break
strict compliance with the RFCs, such as generating emails that
interoperate with email servers that do not themselves follow the
standards, or that implement extensions you want to use in ways that
violate the standards.

Policy objects give the email package the flexibility to handle all
these disparate use cases.

A *note Policy: 12bb. object encapsulates a set of attributes and
methods that control the behavior of various components of the email
package during use.  *note Policy: 12bb. instances can be passed to
various classes and methods in the email package to alter the default
behavior.  The settable values and their defaults are described below.

There is a default policy used by all classes in the email package.  For
all of the *note parser: 52. classes and the related convenience
functions, and for the *note Message: 581. class, this is the *note
Compat32: 12bc. policy, via its corresponding pre-defined instance *note
compat32: e99.  This policy provides for complete backward compatibility
(in some cases, including bug compatibility) with the pre-Python3.3
version of the email package.

This default value for the 'policy' keyword to *note EmailMessage: 580.
is the *note EmailPolicy: 12bf. policy, via its pre-defined instance
*note default: 176d.

When a *note Message: 581. or *note EmailMessage: 580. object is
created, it acquires a policy.  If the message is created by a *note
parser: 52, a policy passed to the parser will be the policy used by the
message it creates.  If the message is created by the program, then the
policy can be specified when it is created.  When a message is passed to
a *note generator: 44, the generator uses the policy from the message by
default, but you can also pass a specific policy to the generator that
will override the one stored on the message object.

The default value for the 'policy' keyword for the *note email.parser:
52. classes and the parser convenience functions 'will be changing' in a
future version of Python.  Therefore you should 'always specify
explicitly which policy you want to use' when calling any of the classes
and functions described in the *note parser: 52. module.

The first part of this documentation covers the features of *note
Policy: 12bb, an *note abstract base class: 13be. that defines the
features that are common to all policy objects, including *note
compat32: e99.  This includes certain hook methods that are called
internally by the email package, which a custom policy could override to
obtain different behavior.  The second part describes the concrete
classes *note EmailPolicy: 12bf. and *note Compat32: 12bc, which
implement the hooks that provide the standard behavior and the backward
compatible behavior and features, respectively.

*note Policy: 12bb. instances are immutable, but they can be cloned,
accepting the same keyword arguments as the class constructor and
returning a new *note Policy: 12bb. instance that is a copy of the
original but with the specified attributes values changed.

As an example, the following code could be used to read an email message
from a file on disk and pass it to the system ‘sendmail’ program on a
Unix system:

     >>> from email import message_from_binary_file
     >>> from email.generator import BytesGenerator
     >>> from email import policy
     >>> from subprocess import Popen, PIPE
     >>> with open('mymsg.txt', 'rb') as f:
     ...     msg = message_from_binary_file(f, policy=policy.default)
     ...
     >>> p = Popen(['sendmail', msg['To'].addresses[0]], stdin=PIPE)
     >>> g = BytesGenerator(p.stdin, policy=msg.policy.clone(linesep='\r\n'))
     >>> g.flatten(msg)
     >>> p.stdin.close()
     >>> rc = p.wait()

Here we are telling *note BytesGenerator: 13d7. to use the RFC correct
line separator characters when creating the binary string to feed into
‘sendmail's’ ‘stdin’, where the default policy would use ‘\n’ line
separators.

Some email package methods accept a 'policy' keyword argument, allowing
the policy to be overridden for that method.  For example, the following
code uses the *note as_bytes(): 1139. method of the 'msg' object from
the previous example and writes the message to a file using the native
line separators for the platform on which it is running:

     >>> import os
     >>> with open('converted.txt', 'wb') as f:
     ...     f.write(msg.as_bytes(policy=msg.policy.clone(linesep=os.linesep)))
     17

Policy objects can also be combined using the addition operator,
producing a policy object whose settings are a combination of the
non-default values of the summed objects:

     >>> compat_SMTP = policy.compat32.clone(linesep='\r\n')
     >>> compat_strict = policy.compat32.clone(raise_on_defect=True)
     >>> compat_strict_SMTP = compat_SMTP + compat_strict

This operation is not commutative; that is, the order in which the
objects are added matters.  To illustrate:

     >>> policy100 = policy.compat32.clone(max_line_length=100)
     >>> policy80 = policy.compat32.clone(max_line_length=80)
     >>> apolicy = policy100 + policy80
     >>> apolicy.max_line_length
     80
     >>> apolicy = policy80 + policy100
     >>> apolicy.max_line_length
     100

 -- Classe: email.policy.Policy (**kw)

     This is the *note abstract base class: 13be. for all policy
     classes.  It provides default implementations for a couple of
     trivial methods, as well as the implementation of the immutability
     property, the *note clone(): 12bd. method, and the constructor
     semantics.

     The constructor of a policy class can be passed various keyword
     arguments.  The arguments that may be specified are any non-method
     properties on this class, plus any additional non-method properties
     on the concrete class.  A value specified in the constructor will
     override the default value for the corresponding attribute.

     This class defines the following properties, and thus values for
     the following may be passed in the constructor of any policy class:

      -- Attributo: max_line_length

          The maximum length of any line in the serialized output, not
          counting the end of line character(s).  Default is 78, per RFC
          5322(2).  A value of ‘0’ or *note None: 886. indicates that no
          line wrapping should be done at all.

      -- Attributo: linesep

          The string to be used to terminate lines in serialized output.
          The default is ‘\n’ because that’s the internal end-of-line
          discipline used by Python, though ‘\r\n’ is required by the
          RFCs.

      -- Attributo: cte_type

          Controls the type of Content Transfer Encodings that may be or
          are required to be used.  The possible values are:

          ‘7bit’       all data must be «7 bit clean» (ASCII-only).  This means that
                       where necessary data will be encoded using either
                       quoted-printable or base64 encoding.
                       
                       
          ‘8bit’       data is not constrained to be 7 bit clean.  Data in headers is
                       still required to be ASCII-only and so will be encoded (see
                       *note fold_binary(): 3af7. and *note utf8: ffb. below for
                       exceptions), but body parts may use the ‘8bit’ CTE.
                       

          A ‘cte_type’ value of ‘8bit’ only works with ‘BytesGenerator’,
          not ‘Generator’, because strings cannot contain binary data.
          If a ‘Generator’ is operating under a policy that specifies
          ‘cte_type=8bit’, it will act as if ‘cte_type’ is ‘7bit’.

      -- Attributo: raise_on_defect

          If *note True: e09, any defects encountered will be raised as
          errors.  If *note False: d2d. (the default), defects will be
          passed to the *note register_defect(): 3af9. method.

      -- Attributo: mangle_from_

          If *note True: e09, lines starting with '«From «' in the body
          are escaped by putting a ‘>’ in front of them.  This parameter
          is used when the message is being serialized by a generator.
          Default: *note False: d2d.

          Added in version 3.5.

      -- Attributo: message_factory

          A factory function for constructing a new empty message
          object.  Used by the parser when building messages.  Defaults
          to ‘None’, in which case *note Message: 581. is used.

          Added in version 3.6.

      -- Attributo: verify_generated_headers

          If ‘True’ (the default), the generator will raise *note
          HeaderWriteError: 3afa. instead of writing a header that is
          improperly folded or delimited, such that it would be parsed
          as multiple headers or joined with adjacent data.  Such
          headers can be generated by custom header classes or bugs in
          the ‘email’ module.

          As it’s a security feature, this defaults to ‘True’ even in
          the *note Compat32: 12bc. policy.  For backwards compatible,
          but unsafe, behavior, it must be set to ‘False’ explicitly.

          Added in version 3.13.

     The following *note Policy: 12bb. method is intended to be called
     by code using the email library to create policy instances with
     custom settings:

      -- Metodo: clone (**kw)

          Return a new *note Policy: 12bb. instance whose attributes
          have the same values as the current instance, except where
          those attributes are given new values by the keyword
          arguments.

     The remaining *note Policy: 12bb. methods are called by the email
     package code, and are not intended to be called by an application
     using the email package.  A custom policy must implement all of
     these methods.

      -- Metodo: handle_defect (obj, defect)

          Handle a 'defect' found on 'obj'.  When the email package
          calls this method, 'defect' will always be a subclass of *note
          MessageDefect: 3afc.

          The default implementation checks the *note raise_on_defect:
          3af8. flag.  If it is ‘True’, 'defect' is raised as an
          exception.  If it is ‘False’ (the default), 'obj' and 'defect'
          are passed to *note register_defect(): 3af9.

      -- Metodo: register_defect (obj, defect)

          Register a 'defect' on 'obj'.  In the email package, 'defect'
          will always be a subclass of *note MessageDefect: 3afc.

          The default implementation calls the ‘append’ method of the
          ‘defects’ attribute of 'obj'.  When the email package calls
          *note handle_defect: 3afb, 'obj' will normally have a
          ‘defects’ attribute that has an ‘append’ method.  Custom
          object types used with the email package (for example, custom
          ‘Message’ objects) should also provide such an attribute,
          otherwise defects in parsed messages will raise unexpected
          errors.

      -- Metodo: header_max_count (name)

          Return the maximum allowed number of headers named 'name'.

          Called when a header is added to an *note EmailMessage: 580.
          or *note Message: 581. object.  If the returned value is not
          ‘0’ or ‘None’, and there are already a number of headers with
          the name 'name' greater than or equal to the value returned, a
          *note ValueError: 2ec. is raised.

          Because the default behavior of ‘Message.__setitem__’ is to
          append the value to the list of headers, it is easy to create
          duplicate headers without realizing it.  This method allows
          certain headers to be limited in the number of instances of
          that header that may be added to a ‘Message’ programmatically.
          (The limit is not observed by the parser, which will
          faithfully produce as many headers as exist in the message
          being parsed.)

          The default implementation returns ‘None’ for all header
          names.

      -- Metodo: header_source_parse (sourcelines)

          The email package calls this method with a list of strings,
          each string ending with the line separation characters found
          in the source being parsed.  The first line includes the field
          header name and separator.  All whitespace in the source is
          preserved.  The method should return the ‘(name, value)’ tuple
          that is to be stored in the ‘Message’ to represent the parsed
          header.

          If an implementation wishes to retain compatibility with the
          existing email package policies, 'name' should be the case
          preserved name (all characters up to the “‘:’” separator),
          while 'value' should be the unfolded value (all line separator
          characters removed, but whitespace kept intact), stripped of
          leading whitespace.

          'sourcelines' may contain surrogateescaped binary data.

          There is no default implementation

      -- Metodo: header_store_parse (name, value)

          The email package calls this method with the name and value
          provided by the application program when the application
          program is modifying a ‘Message’ programmatically (as opposed
          to a ‘Message’ created by a parser).  The method should return
          the ‘(name, value)’ tuple that is to be stored in the
          ‘Message’ to represent the header.

          If an implementation wishes to retain compatibility with the
          existing email package policies, the 'name' and 'value' should
          be strings or string subclasses that do not change the content
          of the passed in arguments.

          There is no default implementation

      -- Metodo: header_fetch_parse (name, value)

          The email package calls this method with the 'name' and
          'value' currently stored in the ‘Message’ when that header is
          requested by the application program, and whatever the method
          returns is what is passed back to the application as the value
          of the header being retrieved.  Note that there may be more
          than one header with the same name stored in the ‘Message’;
          the method is passed the specific name and value of the header
          destined to be returned to the application.

          'value' may contain surrogateescaped binary data.  There
          should be no surrogateescaped binary data in the value
          returned by the method.

          There is no default implementation

      -- Metodo: fold (name, value)

          The email package calls this method with the 'name' and
          'value' currently stored in the ‘Message’ for a given header.
          The method should return a string that represents that header
          «folded» correctly (according to the policy settings) by
          composing the 'name' with the 'value' and inserting *note
          linesep: 3af6. characters at the appropriate places.  See RFC
          5322(3) for a discussion of the rules for folding email
          headers.

          'value' may contain surrogateescaped binary data.  There
          should be no surrogateescaped binary data in the string
          returned by the method.

      -- Metodo: fold_binary (name, value)

          The same as *note fold(): 3b01, except that the returned value
          should be a bytes object rather than a string.

          'value' may contain surrogateescaped binary data.  These could
          be converted back into binary data in the returned bytes
          object.

 -- Classe: email.policy.EmailPolicy (**kw)

     This concrete *note Policy: 12bb. provides behavior that is
     intended to be fully compliant with the current email RFCs.  These
     include (but are not limited to) RFC 5322(4), RFC 2047(5), and the
     current MIME RFCs.

     This policy adds new header parsing and folding algorithms.
     Instead of simple strings, headers are ‘str’ subclasses with
     attributes that depend on the type of the field.  The parsing and
     folding algorithm fully implement RFC 2047(6) and RFC 5322(7).

     The default value for the *note message_factory: e98. attribute is
     *note EmailMessage: 580.

     In addition to the settable attributes listed above that apply to
     all policies, this policy adds the following additional attributes:

     Added in version 3.6: (8)

      -- Attributo: utf8

          If ‘False’, follow RFC 5322(9), supporting non-ASCII
          characters in headers by encoding them as «encoded words».  If
          ‘True’, follow RFC 6532(10) and use ‘utf-8’ encoding for
          headers.  Messages formatted in this way may be passed to SMTP
          servers that support the ‘SMTPUTF8’ extension ( RFC 6531(11)).

      -- Attributo: refold_source

          If the value for a header in the ‘Message’ object originated
          from a *note parser: 52. (as opposed to being set by a
          program), this attribute indicates whether or not a generator
          should refold that value when transforming the message back
          into serialized form.  The possible values are:

          ‘none’       all source values use original folding
                       
                       
          ‘long’       source values that have any line that is longer than
                       ‘max_line_length’ will be refolded
                       
                       
          ‘all’        all values are refolded.
                       

          The default is ‘long’.

      -- Attributo: header_factory

          A callable that takes two arguments, ‘name’ and ‘value’, where
          ‘name’ is a header field name and ‘value’ is an unfolded
          header field value, and returns a string subclass that
          represents that header.  A default ‘header_factory’ (see *note
          headerregistry: 46.) is provided that supports custom parsing
          for the various address and date RFC 5322(12) header field
          types, and the major MIME header field stypes.  Support for
          additional custom parsing will be added in the future.

      -- Attributo: content_manager

          An object with at least two methods: get_content and
          set_content.  When the *note get_content(): 3aca. or *note
          set_content(): 1c45. method of an *note EmailMessage: 580.
          object is called, it calls the corresponding method of this
          object, passing it the message object as its first argument,
          and any arguments or keywords that were passed to it as
          additional arguments.  By default ‘content_manager’ is set to
          *note raw_data_manager: 3b03.

          Added in version 3.4.

     The class provides the following concrete implementations of the
     abstract methods of *note Policy: 12bb.:

      -- Metodo: header_max_count (name)

          Returns the value of the *note max_count: 3b05. attribute of
          the specialized class used to represent the header with the
          given name.

      -- Metodo: header_source_parse (sourcelines)

          The name is parsed as everything up to the “‘:’” and returned
          unmodified.  The value is determined by stripping leading
          whitespace off the remainder of the first line, joining all
          subsequent lines together, and stripping any trailing carriage
          return or linefeed characters.

      -- Metodo: header_store_parse (name, value)

          The name is returned unchanged.  If the input value has a
          ‘name’ attribute and it matches 'name' ignoring case, the
          value is returned unchanged.  Otherwise the 'name' and 'value'
          are passed to ‘header_factory’, and the resulting header
          object is returned as the value.  In this case a ‘ValueError’
          is raised if the input value contains CR or LF characters.

      -- Metodo: header_fetch_parse (name, value)

          If the value has a ‘name’ attribute, it is returned to
          unmodified.  Otherwise the 'name', and the 'value' with any CR
          or LF characters removed, are passed to the ‘header_factory’,
          and the resulting header object is returned.  Any
          surrogateescaped bytes get turned into the unicode
          unknown-character glyph.

      -- Metodo: fold (name, value)

          Header folding is controlled by the *note refold_source: 3aeb.
          policy setting.  A value is considered to be a “source value”
          if and only if it does not have a ‘name’ attribute (having a
          ‘name’ attribute means it is a header object of some sort).
          If a source value needs to be refolded according to the
          policy, it is converted into a header object by passing the
          'name' and the 'value' with any CR and LF characters removed
          to the ‘header_factory’.  Folding of a header object is done
          by calling its ‘fold’ method with the current policy.

          Source values are split into lines using *note splitlines():
          145e.  If the value is not to be refolded, the lines are
          rejoined using the ‘linesep’ from the policy and returned.
          The exception is lines containing non-ascii binary data.  In
          that case the value is refolded regardless of the
          ‘refold_source’ setting, which causes the binary data to be
          CTE encoded using the ‘unknown-8bit’ charset.

      -- Metodo: fold_binary (name, value)

          The same as *note fold(): 19da. if *note cte_type: 3aee. is
          ‘7bit’, except that the returned value is bytes.

          If *note cte_type: 3aee. is ‘8bit’, non-ASCII binary data is
          converted back into bytes.  Headers with binary data are not
          refolded, regardless of the ‘refold_header’ setting, since
          there is no way to know whether the binary data consists of
          single byte characters or multibyte characters.

The following instances of *note EmailPolicy: 12bf. provide defaults
suitable for specific application domains.  Note that in the future the
behavior of these instances (in particular the ‘HTTP’ instance) may be
adjusted to conform even more closely to the RFCs relevant to their
domains.

 -- Dati: email.policy.default

     An instance of ‘EmailPolicy’ with all defaults unchanged.  This
     policy uses the standard Python ‘\n’ line endings rather than the
     RFC-correct ‘\r\n’.

 -- Dati: email.policy.SMTP

     Suitable for serializing messages in conformance with the email
     RFCs.  Like ‘default’, but with ‘linesep’ set to ‘\r\n’, which is
     RFC compliant.

 -- Dati: email.policy.SMTPUTF8

     The same as ‘SMTP’ except that *note utf8: ffb. is ‘True’.  Useful
     for serializing messages to a message store without using encoded
     words in the headers.  Should only be used for SMTP transmission if
     the sender or recipient addresses have non-ASCII characters (the
     *note smtplib.SMTP.send_message(): 105c. method handles this
     automatically).

 -- Dati: email.policy.HTTP

     Suitable for serializing headers with for use in HTTP traffic.
     Like ‘SMTP’ except that ‘max_line_length’ is set to ‘None’
     (unlimited).

 -- Dati: email.policy.strict

     Convenience instance.  The same as ‘default’ except that
     ‘raise_on_defect’ is set to ‘True’.  This allows any policy to be
     made strict by writing:

          somepolicy + policy.strict

With all of these *note EmailPolicies: 12bf, the effective API of the
email package is changed from the Python 3.2 API in the following ways:

   * Setting a header on a *note Message: 581. results in that header
     being parsed and a header object created.

   * Fetching a header value from a *note Message: 581. results in that
     header being parsed and a header object created and returned.

   * Any header object, or any header that is refolded due to the policy
     settings, is folded using an algorithm that fully implements the
     RFC folding algorithms, including knowing where encoded words are
     required and allowed.

From the application view, this means that any header obtained through
the *note EmailMessage: 580. is a header object with extra attributes,
whose string value is the fully decoded unicode value of the header.
Likewise, a header may be assigned a new value, or a new header created,
using a unicode string, and the policy will take care of converting the
unicode string into the correct RFC encoded form.

The header objects and their attributes are described in *note
headerregistry: 46.

 -- Classe: email.policy.Compat32 (**kw)

     This concrete *note Policy: 12bb. is the backward compatibility
     policy.  It replicates the behavior of the email package in Python
     3.2.  The *note policy: 53. module also defines an instance of this
     class, *note compat32: e99, that is used as the default policy.
     Thus the default behavior of the email package is to maintain
     compatibility with Python 3.2.

     The following attributes have values that are different from the
     *note Policy: 12bb. default:

      -- Attributo: mangle_from_

          The default is ‘True’.

     The class provides the following concrete implementations of the
     abstract methods of *note Policy: 12bb.:

      -- Metodo: header_source_parse (sourcelines)

          The name is parsed as everything up to the “‘:’” and returned
          unmodified.  The value is determined by stripping leading
          whitespace off the remainder of the first line, joining all
          subsequent lines together, and stripping any trailing carriage
          return or linefeed characters.

      -- Metodo: header_store_parse (name, value)

          The name and value are returned unmodified.

      -- Metodo: header_fetch_parse (name, value)

          If the value contains binary data, it is converted into a
          *note Header: 1c46. object using the ‘unknown-8bit’ charset.
          Otherwise it is returned unmodified.

      -- Metodo: fold (name, value)

          Headers are folded using the *note Header: 1c46. folding
          algorithm, which preserves existing line breaks in the value,
          and wraps each resulting line to the ‘max_line_length’.
          Non-ASCII binary data are CTE encoded using the ‘unknown-8bit’
          charset.

      -- Metodo: fold_binary (name, value)

          Headers are folded using the *note Header: 1c46. folding
          algorithm, which preserves existing line breaks in the value,
          and wraps each resulting line to the ‘max_line_length’.  If
          ‘cte_type’ is ‘7bit’, non-ascii binary data is CTE encoded
          using the ‘unknown-8bit’ charset.  Otherwise the original
          source header is used, with its existing line breaks and any
          (RFC invalid) binary data it may contain.

 -- Dati: email.policy.compat32

     An instance of *note Compat32: 12bc, providing backward
     compatibility with the behavior of the email package in Python 3.2.

          Nota: The *note compat32: e99. policy should not be used as a
          policy for *note EmailMessage: 580. objects, and should only
          be used to serialize messages that were created using the
          *note compat32: e99. policy.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/email/policy.py

   (2) https://datatracker.ietf.org/doc/html/rfc5322.html

   (3) https://datatracker.ietf.org/doc/html/rfc5322.html

   (4) https://datatracker.ietf.org/doc/html/rfc5322.html

   (5) https://datatracker.ietf.org/doc/html/rfc2047.html

   (6) https://datatracker.ietf.org/doc/html/rfc2047.html

   (7) https://datatracker.ietf.org/doc/html/rfc5322.html

   (8) Originally added in 3.3 as a *note provisional feature: 1244.

   (9) https://datatracker.ietf.org/doc/html/rfc5322.html

   (10) https://datatracker.ietf.org/doc/html/rfc6532.html

   (11) https://datatracker.ietf.org/doc/html/rfc6531.html

   (12) https://datatracker.ietf.org/doc/html/rfc5322.html


File: python.info,  Node: email errors Exception and Defect classes,  Next: email headerregistry Custom Header Objects,  Prev: email policy Policy Objects,  Up: email — An email and MIME handling package

5.20.1.8 ‘email.errors’: Exception and Defect classes
.....................................................

'Source code:' Lib/email/errors.py(1)

__________________________________________________________________

The following exception classes are defined in the *note email.errors:
43. module:

 -- Eccezione: email.errors.MessageError

     This is the base class for all exceptions that the *note email: 3f.
     package can raise.  It is derived from the standard *note
     Exception: bcf. class and defines no additional methods.

 -- Eccezione: email.errors.MessageParseError

     This is the base class for exceptions raised by the *note Parser:
     13a5. class.  It is derived from *note MessageError: 3b15.  This
     class is also used internally by the parser used by *note
     headerregistry: 46.

 -- Eccezione: email.errors.HeaderParseError

     Raised under some error conditions when parsing the RFC 5322(2)
     headers of a message, this class is derived from *note
     MessageParseError: 3b16.  The *note set_boundary(): 3abf. method
     will raise this error if the content type is unknown when the
     method is called.  *note Header: 1c46. may raise this error for
     certain base64 decoding errors, and when an attempt is made to
     create a header that appears to contain an embedded header (that
     is, there is what is supposed to be a continuation line that has no
     leading whitespace and looks like a header).

 -- Eccezione: email.errors.BoundaryError

     Deprecated and no longer used.

 -- Eccezione: email.errors.MultipartConversionError

     Raised if the *note attach(): 3ad1. method is called on an instance
     of a class derived from *note MIMENonMultipart: 3b19. (e.g.  *note
     MIMEImage: 3b1a.).  *note MultipartConversionError: 3b18. multiply
     inherits from *note MessageError: 3b15. and the built-in *note
     TypeError: 198.

 -- Eccezione: email.errors.HeaderWriteError

     Raised when an error occurs when the *note generator: 44. outputs
     headers.

 -- Eccezione: email.errors.MessageDefect

     This is the base class for all defects found when parsing email
     messages.  It is derived from *note ValueError: 2ec.

 -- Eccezione: email.errors.HeaderDefect

     This is the base class for all defects found when parsing email
     headers.  It is derived from *note MessageDefect: 3afc.

Here is the list of the defects that the *note FeedParser: 176c. can
find while parsing messages.  Note that the defects are added to the
message where the problem was found, so for example, if a message nested
inside a ‘multipart/alternative’ had a malformed header, that nested
message object would have a defect, but the containing messages would
not.

All defect classes are subclassed from *note email.errors.MessageDefect:
3afc.

 -- Eccezione: email.errors.NoBoundaryInMultipartDefect

     A message claimed to be a multipart, but had no ‘boundary’
     parameter.

 -- Eccezione: email.errors.StartBoundaryNotFoundDefect

     The start boundary claimed in the ‘Content-Type’ header was never
     found.

 -- Eccezione: email.errors.CloseBoundaryNotFoundDefect

     A start boundary was found, but no corresponding close boundary was
     ever found.

     Added in version 3.3.

 -- Eccezione: email.errors.FirstHeaderLineIsContinuationDefect

     The message had a continuation line as its first header line.

 -- Eccezione: email.errors.MisplacedEnvelopeHeaderDefect

     A «Unix From» header was found in the middle of a header block.

 -- Eccezione: email.errors.MissingHeaderBodySeparatorDefect

     A line was found while parsing headers that had no leading white
     space but contained no “:”.  Parsing continues assuming that the
     line represents the first line of the body.

     Added in version 3.3.

 -- Eccezione: email.errors.MalformedHeaderDefect

     A header was found that was missing a colon, or was otherwise
     malformed.

     Deprecato dalla versione 3.3: This defect has not been used for
     several Python versions.

 -- Eccezione: email.errors.MultipartInvariantViolationDefect

     A message claimed to be a ‘multipart’, but no subparts were found.
     Note that when a message has this defect, its *note is_multipart():
     3ac4. method may return ‘False’ even though its content type claims
     to be ‘multipart’.

 -- Eccezione: email.errors.InvalidBase64PaddingDefect

     When decoding a block of base64 encoded bytes, the padding was not
     correct.  Enough padding is added to perform the decode, but the
     resulting decoded bytes may be invalid.

 -- Eccezione: email.errors.InvalidBase64CharactersDefect

     When decoding a block of base64 encoded bytes, characters outside
     the base64 alphabet were encountered.  The characters are ignored,
     but the resulting decoded bytes may be invalid.

 -- Eccezione: email.errors.InvalidBase64LengthDefect

     When decoding a block of base64 encoded bytes, the number of
     non-padding base64 characters was invalid (1 more than a multiple
     of 4).  The encoded block was kept as-is.

 -- Eccezione: email.errors.InvalidDateDefect

     When decoding an invalid or unparsable date field.  The original
     value is kept as-is.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/email/errors.py

   (2) https://datatracker.ietf.org/doc/html/rfc5322.html


File: python.info,  Node: email headerregistry Custom Header Objects,  Next: email contentmanager Managing MIME Content,  Prev: email errors Exception and Defect classes,  Up: email — An email and MIME handling package

5.20.1.9 ‘email.headerregistry’: Custom Header Objects
......................................................

'Source code:' Lib/email/headerregistry.py(1)

__________________________________________________________________

Added in version 3.6: (2)

Headers are represented by customized subclasses of *note str: 169.  The
particular class used to represent a given header is determined by the
*note header_factory: 3b02. of the *note policy: 53. in effect when the
headers are created.  This section documents the particular
‘header_factory’ implemented by the email package for handling RFC
5322(3) compliant email messages, which not only provides customized
header objects for various header types, but also provides an extension
mechanism for applications to add their own custom header types.

When using any of the policy objects derived from *note EmailPolicy:
12bf, all headers are produced by *note HeaderRegistry: 3b2a. and have
*note BaseHeader: 3aac. as their last base class.  Each header class has
an additional base class that is determined by the type of the header.
For example, many headers have the class *note UnstructuredHeader: 3b2b.
as their other base class.  The specialized second class for a header is
determined by the name of the header, using a lookup table stored in the
*note HeaderRegistry: 3b2a.  All of this is managed transparently for
the typical application program, but interfaces are provided for
modifying the default behavior for use by more complex applications.

The sections below first document the header base classes and their
attributes, followed by the API for modifying the behavior of *note
HeaderRegistry: 3b2a, and finally the support classes used to represent
the data parsed from structured headers.

 -- Classe: email.headerregistry.BaseHeader (name, value)

     'name' and 'value' are passed to ‘BaseHeader’ from the *note
     header_factory: 3b02. call.  The string value of any header object
     is the 'value' fully decoded to unicode.

     This base class defines the following read-only properties:

      -- Attributo: name

          The name of the header (the portion of the field before the
          “:”).  This is exactly the value passed in the *note
          header_factory: 3b02. call for 'name'; that is, case is
          preserved.

      -- Attributo: defects

          A tuple of *note HeaderDefect: 3b1b. instances reporting any
          RFC compliance problems found during parsing.  The email
          package tries to be complete about detecting compliance
          issues.  See the *note errors: 43. module for a discussion of
          the types of defects that may be reported.

      -- Attributo: max_count

          The maximum number of headers of this type that can have the
          same ‘name’.  A value of ‘None’ means unlimited.  The
          ‘BaseHeader’ value for this attribute is ‘None’; it is
          expected that specialized header classes will override this
          value as needed.

     ‘BaseHeader’ also provides the following method, which is called by
     the email library code and should not in general be called by
     application programs:

      -- Metodo: fold (*, policy)

          Return a string containing *note linesep: 3af6. characters as
          required to correctly fold the header according to 'policy'.
          A *note cte_type: 3aee. of ‘8bit’ will be treated as if it
          were ‘7bit’, since headers may not contain arbitrary binary
          data.  If *note utf8: ffb. is ‘False’, non-ASCII data will be
          RFC 2047(4) encoded.

     ‘BaseHeader’ by itself cannot be used to create a header object.
     It defines a protocol that each specialized header cooperates with
     in order to produce the header object.  Specifically, ‘BaseHeader’
     requires that the specialized class provide a *note classmethod():
     48f. named ‘parse’.  This method is called as follows:

          parse(string, kwds)

     ‘kwds’ is a dictionary containing one pre-initialized key,
     ‘defects’.  ‘defects’ is an empty list.  The parse method should
     append any detected defects to this list.  On return, the ‘kwds’
     dictionary 'must' contain values for at least the keys ‘decoded’
     and ‘defects’.  ‘decoded’ should be the string value for the header
     (that is, the header value fully decoded to unicode).  The parse
     method should assume that 'string' may contain
     content-transfer-encoded parts, but should correctly handle all
     valid unicode characters as well so that it can parse un-encoded
     header values.

     ‘BaseHeader’’s ‘__new__’ then creates the header instance, and
     calls its ‘init’ method.  The specialized class only needs to
     provide an ‘init’ method if it wishes to set additional attributes
     beyond those provided by ‘BaseHeader’ itself.  Such an ‘init’
     method should look like this:

          def init(self, /, *args, **kw):
              self._myattr = kw.pop('myattr')
              super().init(*args, **kw)

     That is, anything extra that the specialized class puts in to the
     ‘kwds’ dictionary should be removed and handled, and the remaining
     contents of ‘kw’ (and ‘args’) passed to the ‘BaseHeader’ ‘init’
     method.

 -- Classe: email.headerregistry.UnstructuredHeader

     An «unstructured» header is the default type of header in RFC
     5322(5).  Any header that does not have a specified syntax is
     treated as unstructured.  The classic example of an unstructured
     header is the ‘Subject’ header.

     In RFC 5322(6), an unstructured header is a run of arbitrary text
     in the ASCII character set.  RFC 2047(7), however, has an RFC
     5322(8) compatible mechanism for encoding non-ASCII text as ASCII
     characters within a header value.  When a 'value' containing
     encoded words is passed to the constructor, the
     ‘UnstructuredHeader’ parser converts such encoded words into
     unicode, following the RFC 2047(9) rules for unstructured text.
     The parser uses heuristics to attempt to decode certain
     non-compliant encoded words.  Defects are registered in such cases,
     as well as defects for issues such as invalid characters within the
     encoded words or the non-encoded text.

     This header type provides no additional attributes.

 -- Classe: email.headerregistry.DateHeader

     RFC 5322(10) specifies a very specific format for dates within
     email headers.  The ‘DateHeader’ parser recognizes that date
     format, as well as recognizing a number of variant forms that are
     sometimes found «in the wild».

     This header type provides the following additional attributes:

      -- Attributo: datetime

          If the header value can be recognized as a valid date of one
          form or another, this attribute will contain a *note datetime:
          4e3. instance representing that date.  If the timezone of the
          input date is specified as ‘-0000’ (indicating it is in UTC
          but contains no information about the source timezone), then
          *note datetime: 3b30. will be a naive *note datetime: 4e3.  If
          a specific timezone offset is found (including ‘+0000’), then
          *note datetime: 3b30. will contain an aware ‘datetime’ that
          uses *note datetime.timezone: 12c7. to record the timezone
          offset.

     The ‘decoded’ value of the header is determined by formatting the
     ‘datetime’ according to the RFC 5322(11) rules; that is, it is set
     to:

          email.utils.format_datetime(self.datetime)

     When creating a ‘DateHeader’, 'value' may be *note datetime: 4e3.
     instance.  This means, for example, that the following code is
     valid and does what one would expect:

          msg['Date'] = datetime(2011, 7, 15, 21)

     Because this is a naive ‘datetime’ it will be interpreted as a UTC
     timestamp, and the resulting value will have a timezone of ‘-0000’.
     Much more useful is to use the *note localtime(): 2f7. function
     from the *note utils: 54. module:

          msg['Date'] = utils.localtime()

     This example sets the date header to the current time and date
     using the current timezone offset.

 -- Classe: email.headerregistry.AddressHeader

     Address headers are one of the most complex structured header
     types.  The ‘AddressHeader’ class provides a generic interface to
     any address header.

     This header type provides the following additional attributes:

      -- Attributo: groups

          A tuple of *note Group: 3b33. objects encoding the addresses
          and groups found in the header value.  Addresses that are not
          part of a group are represented in this list as single-address
          ‘Groups’ whose *note display_name: 3b34. is ‘None’.

      -- Attributo: addresses

          A tuple of *note Address: 3b36. objects encoding all of the
          individual addresses from the header value.  If the header
          value contains any groups, the individual addresses from the
          group are included in the list at the point where the group
          occurs in the value (that is, the list of addresses is
          «flattened» into a one dimensional list).

     The ‘decoded’ value of the header will have all encoded words
     decoded to unicode.  *note idna: 56. encoded domain names are also
     decoded to unicode.  The ‘decoded’ value is set by *note joining:
     2631. the *note str: 169. value of the elements of the ‘groups’
     attribute with ‘', '’.

     A list of *note Address: 3b36. and *note Group: 3b33. objects in
     any combination may be used to set the value of an address header.
     ‘Group’ objects whose ‘display_name’ is ‘None’ will be interpreted
     as single addresses, which allows an address list to be copied with
     groups intact by using the list obtained from the ‘groups’
     attribute of the source header.

 -- Classe: email.headerregistry.SingleAddressHeader

     A subclass of *note AddressHeader: 3b31. that adds one additional
     attribute:

      -- Attributo: address

          The single address encoded by the header value.  If the header
          value actually contains more than one address (which would be
          a violation of the RFC under the default *note policy: 53.),
          accessing this attribute will result in a *note ValueError:
          2ec.

Many of the above classes also have a ‘Unique’ variant (for example,
‘UniqueUnstructuredHeader’).  The only difference is that in the
‘Unique’ variant, *note max_count: 3b05. is set to 1.

 -- Classe: email.headerregistry.MIMEVersionHeader

     There is really only one valid value for the ‘MIME-Version’ header,
     and that is ‘1.0’.  For future proofing, this header class supports
     other valid version numbers.  If a version number has a valid value
     per RFC 2045(12), then the header object will have non-‘None’
     values for the following attributes:

      -- Attributo: version

          The version number as a string, with any whitespace and/or
          comments removed.

      -- Attributo: major

          The major version number as an integer

      -- Attributo: minor

          The minor version number as an integer

 -- Classe: email.headerregistry.ParameterizedMIMEHeader

     MIME headers all start with the prefix “Content-”.  Each specific
     header has a certain value, described under the class for that
     header.  Some can also take a list of supplemental parameters,
     which have a common format.  This class serves as a base for all
     the MIME headers that take parameters.

      -- Attributo: params

          A dictionary mapping parameter names to parameter values.

 -- Classe: email.headerregistry.ContentTypeHeader

     A *note ParameterizedMIMEHeader: 3b3d. class that handles the
     ‘Content-Type’ header.

      -- Attributo: content_type

          The content type string, in the form ‘maintype/subtype’.

      -- Attributo: maintype

      -- Attributo: subtype

 -- Classe: email.headerregistry.ContentDispositionHeader

     A *note ParameterizedMIMEHeader: 3b3d. class that handles the
     ‘Content-Disposition’ header.

      -- Attributo: content_disposition

          ‘inline’ and ‘attachment’ are the only valid values in common
          use.

 -- Classe: email.headerregistry.ContentTransferEncodingHeader

     Handles the ‘Content-Transfer-Encoding’ header.

      -- Attributo: cte

          Valid values are ‘7bit’, ‘8bit’, ‘base64’, and
          ‘quoted-printable’.  See RFC 2045(13) for more information.

 -- Classe: email.headerregistry.HeaderRegistry (base_class=BaseHeader,
          default_class=UnstructuredHeader, use_default_map=True)

     This is the factory used by *note EmailPolicy: 12bf. by default.
     ‘HeaderRegistry’ builds the class used to create a header instance
     dynamically, using 'base_class' and a specialized class retrieved
     from a registry that it holds.  When a given header name does not
     appear in the registry, the class specified by 'default_class' is
     used as the specialized class.  When 'use_default_map' is ‘True’
     (the default), the standard mapping of header names to classes is
     copied in to the registry during initialization.  'base_class' is
     always the last class in the generated class’s *note __bases__:
     16b3. list.

     The default mappings are:


          subject: UniqueUnstructuredHeader


          date: UniqueDateHeader


          resent-date: DateHeader


          orig-date: UniqueDateHeader


          sender: UniqueSingleAddressHeader


          resent-sender: SingleAddressHeader


          to: UniqueAddressHeader


          resent-to: AddressHeader


          cc: UniqueAddressHeader


          resent-cc: AddressHeader


          bcc: UniqueAddressHeader


          resent-bcc: AddressHeader


          from: UniqueAddressHeader


          resent-from: AddressHeader


          reply-to: UniqueAddressHeader


          mime-version: MIMEVersionHeader


          content-type: ContentTypeHeader


          content-disposition: ContentDispositionHeader


          content-transfer-encoding: ContentTransferEncodingHeader


          message-id: MessageIDHeader

     ‘HeaderRegistry’ has the following methods:

      -- Metodo: map_to_type (self, name, cls)

          'name' is the name of the header to be mapped.  It will be
          converted to lower case in the registry.  'cls' is the
          specialized class to be used, along with 'base_class', to
          create the class used to instantiate headers that match
          'name'.

      -- Metodo: __getitem__ (name)

          Construct and return a class to handle creating a 'name'
          header.

      -- Metodo: __call__ (name, value)

          Retrieves the specialized header associated with 'name' from
          the registry (using 'default_class' if 'name' does not appear
          in the registry) and composes it with 'base_class' to produce
          a class, calls the constructed class’s constructor, passing it
          the same argument list, and finally returns the class instance
          created thereby.

The following classes are the classes used to represent data parsed from
structured headers and can, in general, be used by an application
program to construct structured values to assign to specific headers.

 -- Classe: email.headerregistry.Address (display_name='', username='',
          domain='', addr_spec=None)

     The class used to represent an email address.  The general form of
     an address is:

          [display_name] <username@domain>

     or:

          username@domain

     where each part must conform to specific syntax rules spelled out
     in RFC 5322(14).

     As a convenience 'addr_spec' can be specified instead of 'username'
     and 'domain', in which case 'username' and 'domain' will be parsed
     from the 'addr_spec'.  An 'addr_spec' must be a properly RFC quoted
     string; if it is not ‘Address’ will raise an error.  Unicode
     characters are allowed and will be property encoded when
     serialized.  However, per the RFCs, unicode is 'not' allowed in the
     username portion of the address.

      -- Attributo: display_name

          The display name portion of the address, if any, with all
          quoting removed.  If the address does not have a display name,
          this attribute will be an empty string.

      -- Attributo: username

          The ‘username’ portion of the address, with all quoting
          removed.

      -- Attributo: domain

          The ‘domain’ portion of the address.

      -- Attributo: addr_spec

          The ‘username@domain’ portion of the address, correctly quoted
          for use as a bare address (the second form shown above).  This
          attribute is not mutable.

      -- Metodo: __str__ ()

          The ‘str’ value of the object is the address quoted according
          to RFC 5322(15) rules, but with no Content Transfer Encoding
          of any non-ASCII characters.

     To support SMTP ( RFC 5321(16)), ‘Address’ handles one special
     case: if ‘username’ and ‘domain’ are both the empty string (or
     ‘None’), then the string value of the ‘Address’ is ‘<>’.

 -- Classe: email.headerregistry.Group (display_name=None,
          addresses=None)

     The class used to represent an address group.  The general form of
     an address group is:

          display_name: [address-list];

     As a convenience for processing lists of addresses that consist of
     a mixture of groups and single addresses, a ‘Group’ may also be
     used to represent single addresses that are not part of a group by
     setting 'display_name' to ‘None’ and providing a list of the single
     address as 'addresses'.

      -- Attributo: display_name

          The ‘display_name’ of the group.  If it is ‘None’ and there is
          exactly one ‘Address’ in ‘addresses’, then the ‘Group’
          represents a single address that is not in a group.

      -- Attributo: addresses

          A possibly empty tuple of *note Address: 3b36. objects
          representing the addresses in the group.

      -- Metodo: __str__ ()

          The ‘str’ value of a ‘Group’ is formatted according to RFC
          5322(17), but with no Content Transfer Encoding of any
          non-ASCII characters.  If ‘display_name’ is none and there is
          a single ‘Address’ in the ‘addresses’ list, the ‘str’ value
          will be the same as the ‘str’ of that single ‘Address’.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/email/headerregistry.py

   (2) Originally added in 3.3 as a *note provisional module: 1244.

   (3) https://datatracker.ietf.org/doc/html/rfc5322.html

   (4) https://datatracker.ietf.org/doc/html/rfc2047.html

   (5) https://datatracker.ietf.org/doc/html/rfc5322.html

   (6) https://datatracker.ietf.org/doc/html/rfc5322.html

   (7) https://datatracker.ietf.org/doc/html/rfc2047.html

   (8) https://datatracker.ietf.org/doc/html/rfc5322.html

   (9) https://datatracker.ietf.org/doc/html/rfc2047.html

   (10) https://datatracker.ietf.org/doc/html/rfc5322.html

   (11) https://datatracker.ietf.org/doc/html/rfc5322.html

   (12) https://datatracker.ietf.org/doc/html/rfc2045.html

   (13) https://datatracker.ietf.org/doc/html/rfc2045.html

   (14) https://datatracker.ietf.org/doc/html/rfc5322.html

   (15) https://datatracker.ietf.org/doc/html/rfc5322.html

   (16) https://datatracker.ietf.org/doc/html/rfc5321.html

   (17) https://datatracker.ietf.org/doc/html/rfc5322.html


File: python.info,  Node: email contentmanager Managing MIME Content,  Next: email Examples,  Prev: email headerregistry Custom Header Objects,  Up: email — An email and MIME handling package

5.20.1.10 ‘email.contentmanager’: Managing MIME Content
.......................................................

'Source code:' Lib/email/contentmanager.py(1)

__________________________________________________________________

Added in version 3.6: (2)

 -- Classe: email.contentmanager.ContentManager

     Base class for content managers.  Provides the standard registry
     mechanisms to register converters between MIME content and other
     representations, as well as the ‘get_content’ and ‘set_content’
     dispatch methods.

      -- Metodo: get_content (msg, *args, **kw)

          Look up a handler function based on the ‘mimetype’ of 'msg'
          (see next paragraph), call it, passing through all arguments,
          and return the result of the call.  The expectation is that
          the handler will extract the payload from 'msg' and return an
          object that encodes information about the extracted data.

          To find the handler, look for the following keys in the
          registry, stopping with the first one found:

             * the string representing the full MIME type
               (‘maintype/subtype’)

             * the string representing the ‘maintype’

             * the empty string

          If none of these keys produce a handler, raise a *note
          KeyError: 5e7. for the full MIME type.

      -- Metodo: set_content (msg, obj, *args, **kw)

          If the ‘maintype’ is ‘multipart’, raise a *note TypeError:
          198.; otherwise look up a handler function based on the type
          of 'obj' (see next paragraph), call *note clear_content():
          3ad5. on the 'msg', and call the handler function, passing
          through all arguments.  The expectation is that the handler
          will transform and store 'obj' into 'msg', possibly making
          other changes to 'msg' as well, such as adding various MIME
          headers to encode information needed to interpret the stored
          data.

          To find the handler, obtain the type of 'obj' (‘typ =
          type(obj)’), and look for the following keys in the registry,
          stopping with the first one found:

             * the type itself (‘typ’)

             * the type’s fully qualified name (‘typ.__module__ + '.' +
               typ.__qualname__’).

             * the type’s *note qualname: 235a. (‘typ.__qualname__’)

             * the type’s *note name: 16b2. (‘typ.__name__’).

          If none of the above match, repeat all of the checks above for
          each of the types in the *note MRO: 18c5. (*note typ.__mro__:
          235e.).  Finally, if no other key yields a handler, check for
          a handler for the key ‘None’.  If there is no handler for
          ‘None’, raise a *note KeyError: 5e7. for the fully qualified
          name of the type.

          Also add a ‘MIME-Version’ header if one is not present (see
          also *note MIMEPart: 113c.).

      -- Metodo: add_get_handler (key, handler)

          Record the function 'handler' as the handler for 'key'.  For
          the possible values of 'key', see *note get_content(): 3b55.

      -- Metodo: add_set_handler (typekey, handler)

          Record 'handler' as the function to call when an object of a
          type matching 'typekey' is passed to *note set_content():
          3b57.  For the possible values of 'typekey', see *note
          set_content(): 3b57.

* Menu:

* Content Manager Instances::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/email/contentmanager.py

   (2) Originally added in 3.4 as a *note provisional module: 1244.


File: python.info,  Node: Content Manager Instances,  Up: email contentmanager Managing MIME Content

5.20.1.11 Content Manager Instances
...................................

Currently the email package provides only one concrete content manager,
*note raw_data_manager: 3b03, although more may be added in the future.
*note raw_data_manager: 3b03. is the *note content_manager: 113d.
provided by *note EmailPolicy: 12bf. and its derivatives.

 -- Dati: email.contentmanager.raw_data_manager

     This content manager provides only a minimum interface beyond that
     provided by *note Message: 581. itself: it deals only with text,
     raw byte strings, and *note Message: 581. objects.  Nevertheless,
     it provides significant advantages compared to the base API:
     ‘get_content’ on a text part will return a unicode string without
     the application needing to manually decode it, ‘set_content’
     provides a rich set of options for controlling the headers added to
     a part and controlling the content transfer encoding, and it
     enables the use of the various ‘add_’ methods, thereby simplifying
     the creation of multipart messages.

      -- Metodo: email.contentmanager.get_content (msg,
               errors='replace')

          Return the payload of the part as either a string (for ‘text’
          parts), an *note EmailMessage: 580. object (for
          ‘message/rfc822’ parts), or a ‘bytes’ object (for all other
          non-multipart types).  Raise a *note KeyError: 5e7. if called
          on a ‘multipart’.  If the part is a ‘text’ part and 'errors'
          is specified, use it as the error handler when decoding the
          payload to unicode.  The default error handler is ‘replace’.

      -- Metodo: email.contentmanager.set_content (msg, <'str'>,
               subtype="plain", charset='utf-8', cte=None,
               disposition=None, filename=None, cid=None, params=None,
               headers=None)

      -- Metodo: email.contentmanager.set_content (msg, <'bytes'>,
               maintype, subtype, cte="base64", disposition=None,
               filename=None, cid=None, params=None, headers=None)

      -- Metodo: email.contentmanager.set_content (msg,
               <'EmailMessage'>, cte=None, disposition=None,
               filename=None, cid=None, params=None, headers=None)

          Add headers and payload to 'msg':

          Add a ‘Content-Type’ header with a ‘maintype/subtype’ value.

             * For ‘str’, set the MIME ‘maintype’ to ‘text’, and set the
               subtype to 'subtype' if it is specified, or ‘plain’ if it
               is not.

             * For ‘bytes’, use the specified 'maintype' and 'subtype',
               or raise a *note TypeError: 198. if they are not
               specified.

             * For *note EmailMessage: 580. objects, set the maintype to
               ‘message’, and set the subtype to 'subtype' if it is
               specified or ‘rfc822’ if it is not.  If 'subtype' is
               ‘partial’, raise an error (‘bytes’ objects must be used
               to construct ‘message/partial’ parts).

          If 'charset' is provided (which is valid only for ‘str’),
          encode the string to bytes using the specified character set.
          The default is ‘utf-8’.  If the specified 'charset' is a known
          alias for a standard MIME charset name, use the standard
          charset instead.

          If 'cte' is set, encode the payload using the specified
          content transfer encoding, and set the
          ‘Content-Transfer-Encoding’ header to that value.  Possible
          values for 'cte' are ‘quoted-printable’, ‘base64’, ‘7bit’,
          ‘8bit’, and ‘binary’.  If the input cannot be encoded in the
          specified encoding (for example, specifying a 'cte' of ‘7bit’
          for an input that contains non-ASCII values), raise a *note
          ValueError: 2ec.

             * For ‘str’ objects, if 'cte' is not set use heuristics to
               determine the most compact encoding.  Prior to encoding,
               *note str.splitlines(): 145e. is used to normalize all
               line boundaries, ensuring that each line of the payload
               is terminated by the current policy’s *note linesep:
               3af6. property (even if the original string did not end
               with one).

             * For ‘bytes’ objects, 'cte' is taken to be base64 if not
               set, and the aforementioned newline translation is not
               performed.

             * For *note EmailMessage: 580, per RFC 2046(1), raise an
               error if a 'cte' of ‘quoted-printable’ or ‘base64’ is
               requested for 'subtype' ‘rfc822’, and for any 'cte' other
               than ‘7bit’ for 'subtype' ‘external-body’.  For
               ‘message/rfc822’, use ‘8bit’ if 'cte' is not specified.
               For all other values of 'subtype', use ‘7bit’.

               Nota: A 'cte' of ‘binary’ does not actually work
               correctly yet.  The ‘EmailMessage’ object as modified by
               ‘set_content’ is correct, but *note BytesGenerator: 13d7.
               does not serialize it correctly.

          If 'disposition' is set, use it as the value of the
          ‘Content-Disposition’ header.  If not specified, and
          'filename' is specified, add the header with the value
          ‘attachment’.  If 'disposition' is not specified and
          'filename' is also not specified, do not add the header.  The
          only valid values for 'disposition' are ‘attachment’ and
          ‘inline’.

          If 'filename' is specified, use it as the value of the
          ‘filename’ parameter of the ‘Content-Disposition’ header.

          If 'cid' is specified, add a ‘Content-ID’ header with 'cid' as
          its value.

          If 'params' is specified, iterate its ‘items’ method and use
          the resulting ‘(key, value)’ pairs to set additional
          parameters on the ‘Content-Type’ header.

          If 'headers' is specified and is a list of strings of the form
          ‘headername: headervalue’ or a list of ‘header’ objects
          (distinguished from strings by having a ‘name’ attribute), add
          the headers to 'msg'.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2046.html


File: python.info,  Node: email Examples,  Next: email message Message Representing an email message using the compat32 API,  Prev: email contentmanager Managing MIME Content,  Up: email — An email and MIME handling package

5.20.1.12 ‘email’: Examples
...........................

Here are a few examples of how to use the *note email: 3f. package to
read, write, and send simple email messages, as well as more complex
MIME messages.

First, let’s see how to create and send a simple text message (both the
text content and the addresses may contain unicode characters):

     # Import smtplib for the actual sending function
     import smtplib

     # Import the email modules we'll need
     from email.message import EmailMessage

     # Open the plain text file whose name is in textfile for reading.
     with open(textfile) as fp:
         # Create a text/plain message
         msg = EmailMessage()
         msg.set_content(fp.read())

     # me == the sender's email address
     # you == the recipient's email address
     msg['Subject'] = f'The contents of {textfile}'
     msg['From'] = me
     msg['To'] = you

     # Send the message via our own SMTP server.
     s = smtplib.SMTP('localhost')
     s.send_message(msg)
     s.quit()

Parsing RFC 822(1) headers can easily be done by the using the classes
from the *note parser: 52. module:

     # Import the email modules we'll need
     #from email.parser import BytesParser
     from email.parser import Parser
     from email.policy import default

     # If the e-mail headers are in a file, uncomment these two lines:
     # with open(messagefile, 'rb') as fp:
     #     headers = BytesParser(policy=default).parse(fp)

     #  Or for parsing headers in a string (this is an uncommon operation), use:
     headers = Parser(policy=default).parsestr(
             'From: Foo Bar <user@example.com>\n'
             'To: <someone_else@example.com>\n'
             'Subject: Test message\n'
             '\n'
             'Body would go here\n')

     #  Now the header items can be accessed as a dictionary:
     print('To: {}'.format(headers['to']))
     print('From: {}'.format(headers['from']))
     print('Subject: {}'.format(headers['subject']))

     # You can also access the parts of the addresses:
     print('Recipient username: {}'.format(headers['to'].addresses[0].username))
     print('Sender name: {}'.format(headers['from'].addresses[0].display_name))

Here’s an example of how to send a MIME message containing a bunch of
family pictures that may be residing in a directory:

     # Import smtplib for the actual sending function.
     import smtplib

     # Here are the email package modules we'll need.
     from email.message import EmailMessage

     # Create the container email message.
     msg = EmailMessage()
     msg['Subject'] = 'Our family reunion'
     # me == the sender's email address
     # family = the list of all recipients' email addresses
     msg['From'] = me
     msg['To'] = ', '.join(family)
     msg.preamble = 'You will not see this in a MIME-aware mail reader.\n'

     # Open the files in binary mode.  You can also omit the subtype
     # if you want MIMEImage to guess it.
     for file in pngfiles:
         with open(file, 'rb') as fp:
             img_data = fp.read()
         msg.add_attachment(img_data, maintype='image',
                                      subtype='png')

     # Send the email via our own SMTP server.
     with smtplib.SMTP('localhost') as s:
         s.send_message(msg)

Here’s an example of how to send the entire contents of a directory as
an email message: (2)

     #!/usr/bin/env python3

     """Send the contents of a directory as a MIME message."""

     import os
     import smtplib
     # For guessing MIME type based on file name extension
     import mimetypes

     from argparse import ArgumentParser

     from email.message import EmailMessage
     from email.policy import SMTP


     def main():
         parser = ArgumentParser(description="""\
     Send the contents of a directory as a MIME message.
     Unless the -o option is given, the email is sent by forwarding to your local
     SMTP server, which then does the normal delivery process.  Your local machine
     must be running an SMTP server.
     """)
         parser.add_argument('-d', '--directory',
                             help="""Mail the contents of the specified directory,
                             otherwise use the current directory.  Only the regular
                             files in the directory are sent, and we don't recurse to
                             subdirectories.""")
         parser.add_argument('-o', '--output',
                             metavar='FILE',
                             help="""Print the composed message to FILE instead of
                             sending the message to the SMTP server.""")
         parser.add_argument('-s', '--sender', required=True,
                             help='The value of the From: header (required)')
         parser.add_argument('-r', '--recipient', required=True,
                             action='append', metavar='RECIPIENT',
                             default=[], dest='recipients',
                             help='A To: header value (at least one required)')
         args = parser.parse_args()
         directory = args.directory
         if not directory:
             directory = '.'
         # Create the message
         msg = EmailMessage()
         msg['Subject'] = f'Contents of directory {os.path.abspath(directory)}'
         msg['To'] = ', '.join(args.recipients)
         msg['From'] = args.sender
         msg.preamble = 'You will not see this in a MIME-aware mail reader.\n'

         for filename in os.listdir(directory):
             path = os.path.join(directory, filename)
             if not os.path.isfile(path):
                 continue
             # Guess the content type based on the file's extension.  Encoding
             # will be ignored, although we should check for simple things like
             # gzip'd or compressed files.
             ctype, encoding = mimetypes.guess_file_type(path)
             if ctype is None or encoding is not None:
                 # No guess could be made, or the file is encoded (compressed), so
                 # use a generic bag-of-bits type.
                 ctype = 'application/octet-stream'
             maintype, subtype = ctype.split('/', 1)
             with open(path, 'rb') as fp:
                 msg.add_attachment(fp.read(),
                                    maintype=maintype,
                                    subtype=subtype,
                                    filename=filename)
         # Now send or store the message
         if args.output:
             with open(args.output, 'wb') as fp:
                 fp.write(msg.as_bytes(policy=SMTP))
         else:
             with smtplib.SMTP('localhost') as s:
                 s.send_message(msg)


     if __name__ == '__main__':
         main()

Here’s an example of how to unpack a MIME message like the one above,
into a directory of files:

     #!/usr/bin/env python3

     """Unpack a MIME message into a directory of files."""

     import os
     import email
     import mimetypes

     from email.policy import default

     from argparse import ArgumentParser


     def main():
         parser = ArgumentParser(description="""\
     Unpack a MIME message into a directory of files.
     """)
         parser.add_argument('-d', '--directory', required=True,
                             help="""Unpack the MIME message into the named
                             directory, which will be created if it doesn't already
                             exist.""")
         parser.add_argument('msgfile')
         args = parser.parse_args()

         with open(args.msgfile, 'rb') as fp:
             msg = email.message_from_binary_file(fp, policy=default)

         try:
             os.mkdir(args.directory)
         except FileExistsError:
             pass

         counter = 1
         for part in msg.walk():
             # multipart/* are just containers
             if part.get_content_maintype() == 'multipart':
                 continue
             # Applications should really sanitize the given filename so that an
             # email message can't be used to overwrite important files
             filename = part.get_filename()
             if not filename:
                 ext = mimetypes.guess_extension(part.get_content_type())
                 if not ext:
                     # Use a generic bag-of-bits extension
                     ext = '.bin'
                 filename = f'part-{counter:03d}{ext}'
             counter += 1
             with open(os.path.join(args.directory, filename), 'wb') as fp:
                 fp.write(part.get_payload(decode=True))


     if __name__ == '__main__':
         main()

Here’s an example of how to create an HTML message with an alternative
plain text version.  To make things a bit more interesting, we include a
related image in the html part, and we save a copy of what we are going
to send to disk, as well as sending it.

     #!/usr/bin/env python3

     import smtplib

     from email.message import EmailMessage
     from email.headerregistry import Address
     from email.utils import make_msgid

     # Create the base text message.
     msg = EmailMessage()
     msg['Subject'] = "Pourquoi pas des asperges pour ce midi ?"
     msg['From'] = Address("Pepé Le Pew", "pepe", "example.com")
     msg['To'] = (Address("Penelope Pussycat", "penelope", "example.com"),
                  Address("Fabrette Pussycat", "fabrette", "example.com"))
     msg.set_content("""\
     Salut!

     Cette recette [1] sera sûrement un très bon repas.

     [1] http://www.yummly.com/recipe/Roasted-Asparagus-Epicurious-203718

     --Pepé
     """)

     # Add the html version.  This converts the message into a multipart/alternative
     # container, with the original text message as the first part and the new html
     # message as the second part.
     asparagus_cid = make_msgid()
     msg.add_alternative("""\
     <html>
       <head></head>
       <body>
         <p>Salut!</p>
         <p>Cette
             <a href="http://www.yummly.com/recipe/Roasted-Asparagus-Epicurious-203718">
                 recette
             </a> sera sûrement un très bon repas.
         </p>
         <img src="cid:{asparagus_cid}">
       </body>
     </html>
     """.format(asparagus_cid=asparagus_cid[1:-1]), subtype='html')
     # note that we needed to peel the <> off the msgid for use in the html.

     # Now add the related image to the html part.
     with open("roasted-asparagus.jpg", 'rb') as img:
         msg.get_payload()[1].add_related(img.read(), 'image', 'jpeg',
                                          cid=asparagus_cid)

     # Make a local copy of what we are going to send.
     with open('outgoing.msg', 'wb') as f:
         f.write(bytes(msg))

     # Send the message via local SMTP server.
     with smtplib.SMTP('localhost') as s:
         s.send_message(msg)

If we were sent the message from the last example, here is one way we
could process it:

     import os
     import sys
     import tempfile
     import mimetypes
     import webbrowser

     # Import the email modules we'll need
     from email import policy
     from email.parser import BytesParser


     def magic_html_parser(html_text, partfiles):
         """Return safety-sanitized html linked to partfiles.

         Rewrite the href="cid:...." attributes to point to the filenames in partfiles.
         Though not trivial, this should be possible using html.parser.
         """
         raise NotImplementedError("Add the magic needed")


     # In a real program you'd get the filename from the arguments.
     with open('outgoing.msg', 'rb') as fp:
         msg = BytesParser(policy=policy.default).parse(fp)

     # Now the header items can be accessed as a dictionary, and any non-ASCII will
     # be converted to unicode:
     print('To:', msg['to'])
     print('From:', msg['from'])
     print('Subject:', msg['subject'])

     # If we want to print a preview of the message content, we can extract whatever
     # the least formatted payload is and print the first three lines.  Of course,
     # if the message has no plain text part printing the first three lines of html
     # is probably useless, but this is just a conceptual example.
     simplest = msg.get_body(preferencelist=('plain', 'html'))
     print()
     print(''.join(simplest.get_content().splitlines(keepends=True)[:3]))

     ans = input("View full message?")
     if ans.lower()[0] == 'n':
         sys.exit()

     # We can extract the richest alternative in order to display it:
     richest = msg.get_body()
     partfiles = {}
     if richest['content-type'].maintype == 'text':
         if richest['content-type'].subtype == 'plain':
             for line in richest.get_content().splitlines():
                 print(line)
             sys.exit()
         elif richest['content-type'].subtype == 'html':
             body = richest
         else:
             print("Don't know how to display {}".format(richest.get_content_type()))
             sys.exit()
     elif richest['content-type'].content_type == 'multipart/related':
         body = richest.get_body(preferencelist=('html'))
         for part in richest.iter_attachments():
             fn = part.get_filename()
             if fn:
                 extension = os.path.splitext(part.get_filename())[1]
             else:
                 extension = mimetypes.guess_extension(part.get_content_type())
             with tempfile.NamedTemporaryFile(suffix=extension, delete=False) as f:
                 f.write(part.get_content())
                 # again strip the <> to go from email form of cid to html form.
                 partfiles[part['content-id'][1:-1]] = f.name
     else:
         print("Don't know how to display {}".format(richest.get_content_type()))
         sys.exit()
     with tempfile.NamedTemporaryFile(mode='w', delete=False) as f:
         f.write(magic_html_parser(body.get_content(), partfiles))
     webbrowser.open(f.name)
     os.remove(f.name)
     for fn in partfiles.values():
         os.remove(fn)

     # Of course, there are lots of email messages that could break this simple
     # minded program, but it will handle the most common ones.

Up to the prompt, the output from the above is:

     To: Penelope Pussycat <penelope@example.com>, Fabrette Pussycat <fabrette@example.com>
     From: Pepé Le Pew <pepe@example.com>
     Subject: Pourquoi pas des asperges pour ce midi ?

     Salut!

     Cette recette [1] sera sûrement un très bon repas.

Legacy API:

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc822.html

   (2) Thanks to Matthew Dixon Cowles for the original inspiration and
examples.


File: python.info,  Node: email message Message Representing an email message using the compat32 API,  Next: email mime Creating email and MIME objects from scratch,  Prev: email Examples,  Up: email — An email and MIME handling package

5.20.1.13 ‘email.message.Message’: Representing an email message using the ‘compat32’ API
.........................................................................................

The *note Message: 581. class is very similar to the *note EmailMessage:
580. class, without the methods added by that class, and with the
default behavior of certain other methods being slightly different.  We
also document here some methods that, while supported by the *note
EmailMessage: 580. class, are not recommended unless you are dealing
with legacy code.

The philosophy and structure of the two classes is otherwise the same.

This document describes the behavior under the default (for *note
Message: 581.) policy *note Compat32: 12bc.  If you are going to use
another policy, you should be using the *note EmailMessage: 580. class
instead.

An email message consists of 'headers' and a 'payload'.  Headers must be
RFC 5322(1) style names and values, where the field name and value are
separated by a colon.  The colon is not part of either the field name or
the field value.  The payload may be a simple text message, or a binary
object, or a structured sequence of sub-messages each with their own set
of headers and their own payload.  The latter type of payload is
indicated by the message having a MIME type such as ‘multipart/*’ or
‘message/rfc822’.

The conceptual model provided by a *note Message: 581. object is that of
an ordered dictionary of headers with additional methods for accessing
both specialized information from the headers, for accessing the
payload, for generating a serialized version of the message, and for
recursively walking over the object tree.  Note that duplicate headers
are supported but special methods must be used to access them.

The *note Message: 581. pseudo-dictionary is indexed by the header
names, which must be ASCII values.  The values of the dictionary are
strings that are supposed to contain only ASCII characters; there is
some special handling for non-ASCII input, but it doesn’t always produce
the correct results.  Headers are stored and returned in case-preserving
form, but field names are matched case-insensitively.  There may also be
a single envelope header, also known as the 'Unix-From' header or the
‘From_’ header.  The 'payload' is either a string or bytes, in the case
of simple message objects, or a list of *note Message: 581. objects, for
MIME container documents (e.g.  ‘multipart/*’ and ‘message/rfc822’).

Here are the methods of the *note Message: 581. class:

 -- Classe: email.message.Message (policy=compat32)

     If 'policy' is specified (it must be an instance of a *note policy:
     53. class) use the rules it specifies to update and serialize the
     representation of the message.  If 'policy' is not set, use the
     *note compat32: 12bc. policy, which maintains backward
     compatibility with the Python 3.2 version of the email package.
     For more information see the *note policy: 53. documentation.

     Cambiato nella versione 3.3: The 'policy' keyword argument was
     added.

      -- Metodo: as_string (unixfrom=False, maxheaderlen=0, policy=None)

          Return the entire message flattened as a string.  When
          optional 'unixfrom' is true, the envelope header is included
          in the returned string.  'unixfrom' defaults to ‘False’.  For
          backward compatibility reasons, 'maxheaderlen' defaults to
          ‘0’, so if you want a different value you must override it
          explicitly (the value specified for 'max_line_length' in the
          policy will be ignored by this method).  The 'policy' argument
          may be used to override the default policy obtained from the
          message instance.  This can be used to control some of the
          formatting produced by the method, since the specified
          'policy' will be passed to the ‘Generator’.

          Flattening the message may trigger changes to the *note
          Message: 581. if defaults need to be filled in to complete the
          transformation to a string (for example, MIME boundaries may
          be generated or modified).

          Note that this method is provided as a convenience and may not
          always format the message the way you want.  For example, by
          default it does not do the mangling of lines that begin with
          ‘From’ that is required by the Unix mbox format.  For more
          flexibility, instantiate a *note Generator: 13d6. instance and
          use its *note flatten(): 3af0. method directly.  For example:

               from io import StringIO
               from email.generator import Generator
               fp = StringIO()
               g = Generator(fp, mangle_from_=True, maxheaderlen=60)
               g.flatten(msg)
               text = fp.getvalue()

          If the message object contains binary data that is not encoded
          according to RFC standards, the non-compliant data will be
          replaced by unicode «unknown character» code points.  (See
          also *note as_bytes(): 1139. and *note BytesGenerator: 13d7.)

          Cambiato nella versione 3.4: the 'policy' keyword argument was
          added.

      -- Metodo: __str__ ()

          Equivalent to *note as_string(): 1138.  Allows ‘str(msg)’ to
          produce a string containing the formatted message.

      -- Metodo: as_bytes (unixfrom=False, policy=None)

          Return the entire message flattened as a bytes object.  When
          optional 'unixfrom' is true, the envelope header is included
          in the returned string.  'unixfrom' defaults to ‘False’.  The
          'policy' argument may be used to override the default policy
          obtained from the message instance.  This can be used to
          control some of the formatting produced by the method, since
          the specified 'policy' will be passed to the ‘BytesGenerator’.

          Flattening the message may trigger changes to the *note
          Message: 581. if defaults need to be filled in to complete the
          transformation to a string (for example, MIME boundaries may
          be generated or modified).

          Note that this method is provided as a convenience and may not
          always format the message the way you want.  For example, by
          default it does not do the mangling of lines that begin with
          ‘From’ that is required by the Unix mbox format.  For more
          flexibility, instantiate a *note BytesGenerator: 13d7.
          instance and use its *note flatten(): 3aec. method directly.
          For example:

               from io import BytesIO
               from email.generator import BytesGenerator
               fp = BytesIO()
               g = BytesGenerator(fp, mangle_from_=True, maxheaderlen=60)
               g.flatten(msg)
               text = fp.getvalue()

          Added in version 3.4.

      -- Metodo: __bytes__ ()

          Equivalent to *note as_bytes(): 1139.  Allows ‘bytes(msg)’ to
          produce a bytes object containing the formatted message.

          Added in version 3.4.

      -- Metodo: is_multipart ()

          Return ‘True’ if the message’s payload is a list of sub-*note
          Message: 581. objects, otherwise return ‘False’.  When *note
          is_multipart(): 3ac4. returns ‘False’, the payload should be a
          string object (which might be a CTE encoded binary payload).
          (Note that *note is_multipart(): 3ac4. returning ‘True’ does
          not necessarily mean that «msg.get_content_maintype() ==
          “multipart”» will return the ‘True’.  For example,
          ‘is_multipart’ will return ‘True’ when the *note Message: 581.
          is of type ‘message/rfc822’.)

      -- Metodo: set_unixfrom (unixfrom)

          Set the message’s envelope header to 'unixfrom', which should
          be a string.

      -- Metodo: get_unixfrom ()

          Return the message’s envelope header.  Defaults to ‘None’ if
          the envelope header was never set.

      -- Metodo: attach (payload)

          Add the given 'payload' to the current payload, which must be
          ‘None’ or a list of *note Message: 581. objects before the
          call.  After the call, the payload will always be a list of
          *note Message: 581. objects.  If you want to set the payload
          to a scalar object (e.g.  a string), use *note set_payload():
          3b62. instead.

          This is a legacy method.  On the *note EmailMessage: 580.
          class its functionality is replaced by *note set_content():
          1c45. and the related ‘make’ and ‘add’ methods.

      -- Metodo: get_payload (i=None, decode=False)

          Return the current payload, which will be a list of *note
          Message: 581. objects when *note is_multipart(): 3ac4. is
          ‘True’, or a string when *note is_multipart(): 3ac4. is
          ‘False’.  If the payload is a list and you mutate the list
          object, you modify the message’s payload in place.

          With optional argument 'i', *note get_payload(): 13d5. will
          return the 'i'-th element of the payload, counting from zero,
          if *note is_multipart(): 3ac4. is ‘True’.  An *note
          IndexError: 173c. will be raised if 'i' is less than 0 or
          greater than or equal to the number of items in the payload.
          If the payload is a string (i.e.  *note is_multipart(): 3ac4.
          is ‘False’) and 'i' is given, a *note TypeError: 198. is
          raised.

          Optional 'decode' is a flag indicating whether the payload
          should be decoded or not, according to the
          ‘Content-Transfer-Encoding’ header.  When ‘True’ and the
          message is not a multipart, the payload will be decoded if
          this header’s value is ‘quoted-printable’ or ‘base64’.  If
          some other encoding is used, or ‘Content-Transfer-Encoding’
          header is missing, the payload is returned as-is (undecoded).
          In all cases the returned value is binary data.  If the
          message is a multipart and the 'decode' flag is ‘True’, then
          ‘None’ is returned.  If the payload is base64 and it was not
          perfectly formed (missing padding, characters outside the
          base64 alphabet), then an appropriate defect will be added to
          the message’s defect property (*note
          InvalidBase64PaddingDefect: 3b23. or *note
          InvalidBase64CharactersDefect: 3b24, respectively).

          When 'decode' is ‘False’ (the default) the body is returned as
          a string without decoding the ‘Content-Transfer-Encoding’.
          However, for a ‘Content-Transfer-Encoding’ of 8bit, an attempt
          is made to decode the original bytes using the ‘charset’
          specified by the ‘Content-Type’ header, using the ‘replace’
          error handler.  If no ‘charset’ is specified, or if the
          ‘charset’ given is not recognized by the email package, the
          body is decoded using the default ASCII charset.

          This is a legacy method.  On the *note EmailMessage: 580.
          class its functionality is replaced by *note get_content():
          3aca. and *note iter_parts(): 3ac9.

      -- Metodo: set_payload (payload, charset=None)

          Set the entire message object’s payload to 'payload'.  It is
          the client’s responsibility to ensure the payload invariants.
          Optional 'charset' sets the message’s default character set;
          see *note set_charset(): 3b63. for details.

          This is a legacy method.  On the *note EmailMessage: 580.
          class its functionality is replaced by *note set_content():
          1c45.

      -- Metodo: set_charset (charset)

          Set the character set of the payload to 'charset', which can
          either be a *note Charset: ffd. instance (see *note
          email.charset: 40.), a string naming a character set, or
          ‘None’.  If it is a string, it will be converted to a *note
          Charset: ffd. instance.  If 'charset' is ‘None’, the ‘charset’
          parameter will be removed from the ‘Content-Type’ header (the
          message will not be otherwise modified).  Anything else will
          generate a *note TypeError: 198.

          If there is no existing ‘MIME-Version’ header one will be
          added.  If there is no existing ‘Content-Type’ header, one
          will be added with a value of ‘text/plain’.  Whether the
          ‘Content-Type’ header already exists or not, its ‘charset’
          parameter will be set to 'charset.output_charset'.  If
          'charset.input_charset' and 'charset.output_charset' differ,
          the payload will be re-encoded to the 'output_charset'.  If
          there is no existing ‘Content-Transfer-Encoding’ header, then
          the payload will be transfer-encoded, if needed, using the
          specified *note Charset: ffd, and a header with the
          appropriate value will be added.  If a
          ‘Content-Transfer-Encoding’ header already exists, the payload
          is assumed to already be correctly encoded using that
          ‘Content-Transfer-Encoding’ and is not modified.

          This is a legacy method.  On the *note EmailMessage: 580.
          class its functionality is replaced by the 'charset' parameter
          of the *note email.message.EmailMessage.set_content(): 1c45.
          method.

      -- Metodo: get_charset ()

          Return the *note Charset: ffd. instance associated with the
          message’s payload.

          This is a legacy method.  On the *note EmailMessage: 580.
          class it always returns ‘None’.

     The following methods implement a mapping-like interface for
     accessing the message’s RFC 2822(2) headers.  Note that there are
     some semantic differences between these methods and a normal
     mapping (i.e.  dictionary) interface.  For example, in a dictionary
     there are no duplicate keys, but here there may be duplicate
     message headers.  Also, in dictionaries there is no guaranteed
     order to the keys returned by *note keys(): 3b65, but in a *note
     Message: 581. object, headers are always returned in the order they
     appeared in the original message, or were added to the message
     later.  Any header deleted and then re-added are always appended to
     the end of the header list.

     These semantic differences are intentional and are biased toward
     maximal convenience.

     Note that in all cases, any envelope header present in the message
     is not included in the mapping interface.

     In a model generated from bytes, any header values that (in
     contravention of the RFCs) contain non-ASCII bytes will, when
     retrieved through this interface, be represented as *note Header:
     1c46. objects with a charset of ‘unknown-8bit’.

      -- Metodo: __len__ ()

          Return the total number of headers, including duplicates.

      -- Metodo: __contains__ (name)

          Return ‘True’ if the message object has a field named 'name'.
          Matching is done case-insensitively and 'name' should not
          include the trailing colon.  Used for the ‘in’ operator, e.g.:

               if 'message-id' in myMessage:
                  print('Message-ID:', myMessage['message-id'])

      -- Metodo: __getitem__ (name)

          Return the value of the named header field.  'name' should not
          include the colon field separator.  If the header is missing,
          ‘None’ is returned; a *note KeyError: 5e7. is never raised.

          Note that if the named field appears more than once in the
          message’s headers, exactly which of those field values will be
          returned is undefined.  Use the *note get_all(): 3b68. method
          to get the values of all the extant named headers.

      -- Metodo: __setitem__ (name, val)

          Add a header to the message with field name 'name' and value
          'val'.  The field is appended to the end of the message’s
          existing fields.

          Note that this does 'not' overwrite or delete any existing
          header with the same name.  If you want to ensure that the new
          header is the only one present in the message with field name
          'name', delete the field first, e.g.:

               del msg['subject']
               msg['subject'] = 'Python roolz!'

      -- Metodo: __delitem__ (name)

          Delete all occurrences of the field with name 'name' from the
          message’s headers.  No exception is raised if the named field
          isn’t present in the headers.

      -- Metodo: keys ()

          Return a list of all the message’s header field names.

      -- Metodo: values ()

          Return a list of all the message’s field values.

      -- Metodo: items ()

          Return a list of 2-tuples containing all the message’s field
          headers and values.

      -- Metodo: get (name, failobj=None)

          Return the value of the named header field.  This is identical
          to *note __getitem__(): 588. except that optional 'failobj' is
          returned if the named header is missing (defaults to ‘None’).

     Here are some additional useful methods:

      -- Metodo: get_all (name, failobj=None)

          Return a list of all the values for the field named 'name'.
          If there are no such named headers in the message, 'failobj'
          is returned (defaults to ‘None’).

      -- Metodo: add_header (_name, _value, **_params)

          Extended header setting.  This method is similar to *note
          __setitem__(): 1865. except that additional header parameters
          can be provided as keyword arguments.  '_name' is the header
          field to add and '_value' is the 'primary' value for the
          header.

          For each item in the keyword argument dictionary '_params',
          the key is taken as the parameter name, with underscores
          converted to dashes (since dashes are illegal in Python
          identifiers).  Normally, the parameter will be added as
          ‘key="value"’ unless the value is ‘None’, in which case only
          the key will be added.  If the value contains non-ASCII
          characters, it can be specified as a three tuple in the format
          ‘(CHARSET, LANGUAGE, VALUE)’, where ‘CHARSET’ is a string
          naming the charset to be used to encode the value, ‘LANGUAGE’
          can usually be set to ‘None’ or the empty string (see RFC
          2231(3) for other possibilities), and ‘VALUE’ is the string
          value containing non-ASCII code points.  If a three tuple is
          not passed and the value contains non-ASCII characters, it is
          automatically encoded in RFC 2231(4) format using a ‘CHARSET’
          of ‘utf-8’ and a ‘LANGUAGE’ of ‘None’.

          Here’s an example:

               msg.add_header('Content-Disposition', 'attachment', filename='bud.gif')

          This will add a header that looks like

               Content-Disposition: attachment; filename="bud.gif"

          An example with non-ASCII characters:

               msg.add_header('Content-Disposition', 'attachment',
                              filename=('iso-8859-1', '', 'Fußballer.ppt'))

          Which produces

               Content-Disposition: attachment; filename*="iso-8859-1''Fu%DFballer.ppt"

      -- Metodo: replace_header (_name, _value)

          Replace a header.  Replace the first header found in the
          message that matches '_name', retaining header order and field
          name case.  If no matching header was found, a *note KeyError:
          5e7. is raised.

      -- Metodo: get_content_type ()

          Return the message’s content type.  The returned string is
          coerced to lower case of the form ‘maintype/subtype’.  If
          there was no ‘Content-Type’ header in the message the default
          type as given by *note get_default_type(): 3b6f. will be
          returned.  Since according to RFC 2045(5), messages always
          have a default type, *note get_content_type(): 3b6e. will
          always return a value.

          RFC 2045(6) defines a message’s default type to be
          ‘text/plain’ unless it appears inside a ‘multipart/digest’
          container, in which case it would be ‘message/rfc822’.  If the
          ‘Content-Type’ header has an invalid type specification, RFC
          2045(7) mandates that the default type be ‘text/plain’.

      -- Metodo: get_content_maintype ()

          Return the message’s main content type.  This is the
          ‘maintype’ part of the string returned by *note
          get_content_type(): 3b6e.

      -- Metodo: get_content_subtype ()

          Return the message’s sub-content type.  This is the ‘subtype’
          part of the string returned by *note get_content_type(): 3b6e.

      -- Metodo: get_default_type ()

          Return the default content type.  Most messages have a default
          content type of ‘text/plain’, except for messages that are
          subparts of ‘multipart/digest’ containers.  Such subparts have
          a default content type of ‘message/rfc822’.

      -- Metodo: set_default_type (ctype)

          Set the default content type.  'ctype' should either be
          ‘text/plain’ or ‘message/rfc822’, although this is not
          enforced.  The default content type is not stored in the
          ‘Content-Type’ header.

      -- Metodo: get_params (failobj=None, header='content-type',
               unquote=True)

          Return the message’s ‘Content-Type’ parameters, as a list.
          The elements of the returned list are 2-tuples of key/value
          pairs, as split on the ‘'='’ sign.  The left hand side of the
          ‘'='’ is the key, while the right hand side is the value.  If
          there is no ‘'='’ sign in the parameter the value is the empty
          string, otherwise the value is as described in *note
          get_param(): 3b74. and is unquoted if optional 'unquote' is
          ‘True’ (the default).

          Optional 'failobj' is the object to return if there is no
          ‘Content-Type’ header.  Optional 'header' is the header to
          search instead of ‘Content-Type’.

          This is a legacy method.  On the *note EmailMessage: 580.
          class its functionality is replaced by the 'params' property
          of the individual header objects returned by the header access
          methods.

      -- Metodo: get_param (param, failobj=None, header='content-type',
               unquote=True)

          Return the value of the ‘Content-Type’ header’s parameter
          'param' as a string.  If the message has no ‘Content-Type’
          header or if there is no such parameter, then 'failobj' is
          returned (defaults to ‘None’).

          Optional 'header' if given, specifies the message header to
          use instead of ‘Content-Type’.

          Parameter keys are always compared case insensitively.  The
          return value can either be a string, or a 3-tuple if the
          parameter was RFC 2231(8) encoded.  When it’s a 3-tuple, the
          elements of the value are of the form ‘(CHARSET, LANGUAGE,
          VALUE)’.  Note that both ‘CHARSET’ and ‘LANGUAGE’ can be
          ‘None’, in which case you should consider ‘VALUE’ to be
          encoded in the ‘us-ascii’ charset.  You can usually ignore
          ‘LANGUAGE’.

          If your application doesn’t care whether the parameter was
          encoded as in RFC 2231(9), you can collapse the parameter
          value by calling *note email.utils.collapse_rfc2231_value():
          3b75, passing in the return value from *note get_param():
          3b74.  This will return a suitably decoded Unicode string when
          the value is a tuple, or the original string unquoted if it
          isn’t.  For example:

               rawparam = msg.get_param('foo')
               param = email.utils.collapse_rfc2231_value(rawparam)

          In any case, the parameter value (either the returned string,
          or the ‘VALUE’ item in the 3-tuple) is always unquoted, unless
          'unquote' is set to ‘False’.

          This is a legacy method.  On the *note EmailMessage: 580.
          class its functionality is replaced by the 'params' property
          of the individual header objects returned by the header access
          methods.

      -- Metodo: set_param (param, value, header='Content-Type',
               requote=True, charset=None, language='', replace=False)

          Set a parameter in the ‘Content-Type’ header.  If the
          parameter already exists in the header, its value will be
          replaced with 'value'.  If the ‘Content-Type’ header as not
          yet been defined for this message, it will be set to
          ‘text/plain’ and the new parameter value will be appended as
          per RFC 2045(10).

          Optional 'header' specifies an alternative header to
          ‘Content-Type’, and all parameters will be quoted as necessary
          unless optional 'requote' is ‘False’ (the default is ‘True’).

          If optional 'charset' is specified, the parameter will be
          encoded according to RFC 2231(11).  Optional 'language'
          specifies the RFC 2231 language, defaulting to the empty
          string.  Both 'charset' and 'language' should be strings.

          If 'replace' is ‘False’ (the default) the header is moved to
          the end of the list of headers.  If 'replace' is ‘True’, the
          header will be updated in place.

          Cambiato nella versione 3.4: ‘replace’ keyword was added.

      -- Metodo: del_param (param, header='content-type', requote=True)

          Remove the given parameter completely from the ‘Content-Type’
          header.  The header will be re-written in place without the
          parameter or its value.  All values will be quoted as
          necessary unless 'requote' is ‘False’ (the default is ‘True’).
          Optional 'header' specifies an alternative to ‘Content-Type’.

      -- Metodo: set_type (type, header='Content-Type', requote=True)

          Set the main type and subtype for the ‘Content-Type’ header.
          'type' must be a string in the form ‘maintype/subtype’,
          otherwise a *note ValueError: 2ec. is raised.

          This method replaces the ‘Content-Type’ header, keeping all
          the parameters in place.  If 'requote' is ‘False’, this leaves
          the existing header’s quoting as is, otherwise the parameters
          will be quoted (the default).

          An alternative header can be specified in the 'header'
          argument.  When the ‘Content-Type’ header is set a
          ‘MIME-Version’ header is also added.

          This is a legacy method.  On the *note EmailMessage: 580.
          class its functionality is replaced by the ‘make_’ and ‘add_’
          methods.

      -- Metodo: get_filename (failobj=None)

          Return the value of the ‘filename’ parameter of the
          ‘Content-Disposition’ header of the message.  If the header
          does not have a ‘filename’ parameter, this method falls back
          to looking for the ‘name’ parameter on the ‘Content-Type’
          header.  If neither is found, or the header is missing, then
          'failobj' is returned.  The returned string will always be
          unquoted as per *note email.utils.unquote(): 3abd.

      -- Metodo: get_boundary (failobj=None)

          Return the value of the ‘boundary’ parameter of the
          ‘Content-Type’ header of the message, or 'failobj' if either
          the header is missing, or has no ‘boundary’ parameter.  The
          returned string will always be unquoted as per *note
          email.utils.unquote(): 3abd.

      -- Metodo: set_boundary (boundary)

          Set the ‘boundary’ parameter of the ‘Content-Type’ header to
          'boundary'.  *note set_boundary(): 3b7a. will always quote
          'boundary' if necessary.  A *note HeaderParseError: 3ac0. is
          raised if the message object has no ‘Content-Type’ header.

          Note that using this method is subtly different than deleting
          the old ‘Content-Type’ header and adding a new one with the
          new boundary via *note add_header(): 1866, because *note
          set_boundary(): 3b7a. preserves the order of the
          ‘Content-Type’ header in the list of headers.  However, it
          does 'not' preserve any continuation lines which may have been
          present in the original ‘Content-Type’ header.

      -- Metodo: get_content_charset (failobj=None)

          Return the ‘charset’ parameter of the ‘Content-Type’ header,
          coerced to lower case.  If there is no ‘Content-Type’ header,
          or if that header has no ‘charset’ parameter, 'failobj' is
          returned.

          Note that this method differs from *note get_charset(): 3b64.
          which returns the *note Charset: ffd. instance for the default
          encoding of the message body.

      -- Metodo: get_charsets (failobj=None)

          Return a list containing the character set names in the
          message.  If the message is a ‘multipart’, then the list will
          contain one element for each subpart in the payload,
          otherwise, it will be a list of length 1.

          Each item in the list will be a string which is the value of
          the ‘charset’ parameter in the ‘Content-Type’ header for the
          represented subpart.  However, if the subpart has no
          ‘Content-Type’ header, no ‘charset’ parameter, or is not of
          the ‘text’ main MIME type, then that item in the returned list
          will be 'failobj'.

      -- Metodo: get_content_disposition ()

          Return the lowercased value (without parameters) of the
          message’s ‘Content-Disposition’ header if it has one, or
          ‘None’.  The possible values for this method are 'inline',
          'attachment' or ‘None’ if the message follows RFC 2183(12).

          Added in version 3.5.

      -- Metodo: walk ()

          The *note walk(): 3b7d. method is an all-purpose generator
          which can be used to iterate over all the parts and subparts
          of a message object tree, in depth-first traversal order.  You
          will typically use *note walk(): 3b7d. as the iterator in a
          ‘for’ loop; each iteration returns the next subpart.

          Here’s an example that prints the MIME type of every part of a
          multipart message structure:

               >>> for part in msg.walk():
               ...     print(part.get_content_type())
               multipart/report
               text/plain
               message/delivery-status
               text/plain
               text/plain
               message/rfc822
               text/plain

          ‘walk’ iterates over the subparts of any part where *note
          is_multipart(): 3ac4. returns ‘True’, even though
          ‘msg.get_content_maintype() == 'multipart'’ may return
          ‘False’.  We can see this in our example by making use of the
          ‘_structure’ debug helper function:

               >>> for part in msg.walk():
               ...     print(part.get_content_maintype() == 'multipart',
               ...           part.is_multipart())
               True True
               False False
               False True
               False False
               False False
               False True
               False False
               >>> _structure(msg)
               multipart/report
                   text/plain
                   message/delivery-status
                       text/plain
                       text/plain
                   message/rfc822
                       text/plain

          Here the ‘message’ parts are not ‘multiparts’, but they do
          contain subparts.  ‘is_multipart()’ returns ‘True’ and ‘walk’
          descends into the subparts.

     *note Message: 581. objects can also optionally contain two
     instance attributes, which can be used when generating the plain
     text of a MIME message.

      -- Attributo: preamble

          The format of a MIME document allows for some text between the
          blank line following the headers, and the first multipart
          boundary string.  Normally, this text is never visible in a
          MIME-aware mail reader because it falls outside the standard
          MIME armor.  However, when viewing the raw text of the
          message, or when viewing the message in a non-MIME aware
          reader, this text can become visible.

          The 'preamble' attribute contains this leading extra-armor
          text for MIME documents.  When the *note Parser: 13a5.
          discovers some text after the headers but before the first
          boundary string, it assigns this text to the message’s
          'preamble' attribute.  When the *note Generator: 13d6. is
          writing out the plain text representation of a MIME message,
          and it finds the message has a 'preamble' attribute, it will
          write this text in the area between the headers and the first
          boundary.  See *note email.parser: 52. and *note
          email.generator: 44. for details.

          Note that if the message object has no preamble, the
          'preamble' attribute will be ‘None’.

      -- Attributo: epilogue

          The 'epilogue' attribute acts the same way as the 'preamble'
          attribute, except that it contains text that appears between
          the last boundary and the end of the message.

          You do not need to set the epilogue to the empty string in
          order for the *note Generator: 13d6. to print a newline at the
          end of the file.

      -- Attributo: defects

          The 'defects' attribute contains a list of all the problems
          found when parsing this message.  See *note email.errors: 43.
          for a detailed description of the possible parsing defects.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc5322.html

   (2) https://datatracker.ietf.org/doc/html/rfc2822.html

   (3) https://datatracker.ietf.org/doc/html/rfc2231.html

   (4) https://datatracker.ietf.org/doc/html/rfc2231.html

   (5) https://datatracker.ietf.org/doc/html/rfc2045.html

   (6) https://datatracker.ietf.org/doc/html/rfc2045.html

   (7) https://datatracker.ietf.org/doc/html/rfc2045.html

   (8) https://datatracker.ietf.org/doc/html/rfc2231.html

   (9) https://datatracker.ietf.org/doc/html/rfc2231.html

   (10) https://datatracker.ietf.org/doc/html/rfc2045.html

   (11) https://datatracker.ietf.org/doc/html/rfc2231.html

   (12) https://datatracker.ietf.org/doc/html/rfc2183.html


File: python.info,  Node: email mime Creating email and MIME objects from scratch,  Next: email header Internationalized headers,  Prev: email message Message Representing an email message using the compat32 API,  Up: email — An email and MIME handling package

5.20.1.14 ‘email.mime’: Creating email and MIME objects from scratch
....................................................................

'Source code:' Lib/email/mime/(1)

__________________________________________________________________

This module is part of the legacy (‘Compat32’) email API. Its
functionality is partially replaced by the *note contentmanager: 41. in
the new API, but in certain applications these classes may still be
useful, even in non-legacy code.

Ordinarily, you get a message object structure by passing a file or some
text to a parser, which parses the text and returns the root message
object.  However you can also build a complete message structure from
scratch, or even individual *note Message: 581. objects by hand.  In
fact, you can also take an existing structure and add new *note Message:
581. objects, move them around, etc.  This makes a very convenient
interface for slicing-and-dicing MIME messages.

You can create a new object structure by creating *note Message: 581.
instances, adding attachments and all the appropriate headers manually.
For MIME messages though, the *note email: 3f. package provides some
convenient subclasses to make things easier.

Here are the classes:

 -- Classe: email.mime.base.MIMEBase (_maintype, _subtype, *,
          policy=compat32, **_params)

     Module: *note email.mime.base: 4c.

     This is the base class for all the MIME-specific subclasses of
     *note Message: 581.  Ordinarily you won’t create instances
     specifically of *note MIMEBase: 3b84, although you could.  *note
     MIMEBase: 3b84. is provided primarily as a convenient base class
     for more specific MIME-aware subclasses.

     '_maintype' is the ‘Content-Type’ major type (e.g.  ‘text’ or
     ‘image’), and '_subtype' is the ‘Content-Type’ minor type (e.g.
     ‘plain’ or ‘gif’).  '_params' is a parameter key/value dictionary
     and is passed directly to *note Message.add_header: 1866.

     If 'policy' is specified, (defaults to the *note compat32: 12bc.
     policy) it will be passed to *note Message: 581.

     The *note MIMEBase: 3b84. class always adds a ‘Content-Type’ header
     (based on '_maintype', '_subtype', and '_params'), and a
     ‘MIME-Version’ header (always set to ‘1.0’).

     Cambiato nella versione 3.6: Added 'policy' keyword-only parameter.

 -- Classe: email.mime.nonmultipart.MIMENonMultipart

     Module: *note email.mime.nonmultipart: 50.

     A subclass of *note MIMEBase: 3b84, this is an intermediate base
     class for MIME messages that are not ‘multipart’.  The primary
     purpose of this class is to prevent the use of the *note attach():
     3ad1. method, which only makes sense for ‘multipart’ messages.  If
     *note attach(): 3ad1. is called, a *note MultipartConversionError:
     3b18. exception is raised.

 -- Classe: email.mime.multipart.MIMEMultipart (_subtype='mixed',
          boundary=None, _subparts=None, *, policy=compat32, **_params)

     Module: *note email.mime.multipart: 4f.

     A subclass of *note MIMEBase: 3b84, this is an intermediate base
     class for MIME messages that are ‘multipart’.  Optional '_subtype'
     defaults to ‘mixed’, but can be used to specify the subtype of the
     message.  A ‘Content-Type’ header of ‘multipart/_subtype’ will be
     added to the message object.  A ‘MIME-Version’ header will also be
     added.

     Optional 'boundary' is the multipart boundary string.  When ‘None’
     (the default), the boundary is calculated when needed (for example,
     when the message is serialized).

     '_subparts' is a sequence of initial subparts for the payload.  It
     must be possible to convert this sequence to a list.  You can
     always attach new subparts to the message by using the *note
     Message.attach: 3ad1. method.

     Optional 'policy' argument defaults to *note compat32: 12bc.

     Additional parameters for the ‘Content-Type’ header are taken from
     the keyword arguments, or passed into the '_params' argument, which
     is a keyword dictionary.

     Cambiato nella versione 3.6: Added 'policy' keyword-only parameter.

 -- Classe: email.mime.application.MIMEApplication (_data,
          _subtype='octet-stream',
          _encoder=email.encoders.encode_base64, *, policy=compat32,
          **_params)

     Module: *note email.mime.application: 4a.

     A subclass of *note MIMENonMultipart: 3b19, the *note
     MIMEApplication: 3b86. class is used to represent MIME message
     objects of major type ‘application’.  '_data' contains the bytes
     for the raw application data.  Optional '_subtype' specifies the
     MIME subtype and defaults to ‘octet-stream’.

     Optional '_encoder' is a callable (i.e.  function) which will
     perform the actual encoding of the data for transport.  This
     callable takes one argument, which is the *note MIMEApplication:
     3b86. instance.  It should use *note get_payload(): 13d5. and *note
     set_payload(): 3b62. to change the payload to encoded form.  It
     should also add any ‘Content-Transfer-Encoding’ or other headers to
     the message object as necessary.  The default encoding is base64.
     See the *note email.encoders: 42. module for a list of the built-in
     encoders.

     Optional 'policy' argument defaults to *note compat32: 12bc.

     '_params' are passed straight through to the base class
     constructor.

     Cambiato nella versione 3.6: Added 'policy' keyword-only parameter.

 -- Classe: email.mime.audio.MIMEAudio (_audiodata, _subtype=None,
          _encoder=email.encoders.encode_base64, *, policy=compat32,
          **_params)

     Module: *note email.mime.audio: 4b.

     A subclass of *note MIMENonMultipart: 3b19, the *note MIMEAudio:
     3b87. class is used to create MIME message objects of major type
     ‘audio’.  '_audiodata' contains the bytes for the raw audio data.
     If this data can be decoded as au, wav, aiff, or aifc, then the
     subtype will be automatically included in the ‘Content-Type’
     header.  Otherwise you can explicitly specify the audio subtype via
     the '_subtype' argument.  If the minor type could not be guessed
     and '_subtype' was not given, then *note TypeError: 198. is raised.

     Optional '_encoder' is a callable (i.e.  function) which will
     perform the actual encoding of the audio data for transport.  This
     callable takes one argument, which is the *note MIMEAudio: 3b87.
     instance.  It should use *note get_payload(): 13d5. and *note
     set_payload(): 3b62. to change the payload to encoded form.  It
     should also add any ‘Content-Transfer-Encoding’ or other headers to
     the message object as necessary.  The default encoding is base64.
     See the *note email.encoders: 42. module for a list of the built-in
     encoders.

     Optional 'policy' argument defaults to *note compat32: 12bc.

     '_params' are passed straight through to the base class
     constructor.

     Cambiato nella versione 3.6: Added 'policy' keyword-only parameter.

 -- Classe: email.mime.image.MIMEImage (_imagedata, _subtype=None,
          _encoder=email.encoders.encode_base64, *, policy=compat32,
          **_params)

     Module: *note email.mime.image: 4d.

     A subclass of *note MIMENonMultipart: 3b19, the *note MIMEImage:
     3b1a. class is used to create MIME message objects of major type
     ‘image’.  '_imagedata' contains the bytes for the raw image data.
     If this data type can be detected (jpeg, png, gif, tiff, rgb, pbm,
     pgm, ppm, rast, xbm, bmp, webp, and exr attempted), then the
     subtype will be automatically included in the ‘Content-Type’
     header.  Otherwise you can explicitly specify the image subtype via
     the '_subtype' argument.  If the minor type could not be guessed
     and '_subtype' was not given, then *note TypeError: 198. is raised.

     Optional '_encoder' is a callable (i.e.  function) which will
     perform the actual encoding of the image data for transport.  This
     callable takes one argument, which is the *note MIMEImage: 3b1a.
     instance.  It should use *note get_payload(): 13d5. and *note
     set_payload(): 3b62. to change the payload to encoded form.  It
     should also add any ‘Content-Transfer-Encoding’ or other headers to
     the message object as necessary.  The default encoding is base64.
     See the *note email.encoders: 42. module for a list of the built-in
     encoders.

     Optional 'policy' argument defaults to *note compat32: 12bc.

     '_params' are passed straight through to the *note MIMEBase: 3b84.
     constructor.

     Cambiato nella versione 3.6: Added 'policy' keyword-only parameter.

 -- Classe: email.mime.message.MIMEMessage (_msg, _subtype='rfc822', *,
          policy=compat32)

     Module: *note email.mime.message: 4e.

     A subclass of *note MIMENonMultipart: 3b19, the *note MIMEMessage:
     3b88. class is used to create MIME objects of main type ‘message’.
     '_msg' is used as the payload, and must be an instance of class
     *note Message: 581. (or a subclass thereof), otherwise a *note
     TypeError: 198. is raised.

     Optional '_subtype' sets the subtype of the message; it defaults to
     ‘rfc822’.

     Optional 'policy' argument defaults to *note compat32: 12bc.

     Cambiato nella versione 3.6: Added 'policy' keyword-only parameter.

 -- Classe: email.mime.text.MIMEText (_text, _subtype='plain',
          _charset=None, *, policy=compat32)

     Module: *note email.mime.text: 51.

     A subclass of *note MIMENonMultipart: 3b19, the *note MIMEText:
     ffc. class is used to create MIME objects of major type ‘text’.
     '_text' is the string for the payload.  '_subtype' is the minor
     type and defaults to ‘plain’.  '_charset' is the character set of
     the text and is passed as an argument to the *note
     MIMENonMultipart: 3b19. constructor; it defaults to ‘us-ascii’ if
     the string contains only ‘ascii’ code points, and ‘utf-8’
     otherwise.  The '_charset' parameter accepts either a string or a
     *note Charset: ffd. instance.

     Unless the '_charset' argument is explicitly set to ‘None’, the
     MIMEText object created will have both a ‘Content-Type’ header with
     a ‘charset’ parameter, and a ‘Content-Transfer-Encoding’ header.
     This means that a subsequent ‘set_payload’ call will not result in
     an encoded payload, even if a charset is passed in the
     ‘set_payload’ command.  You can «reset» this behavior by deleting
     the ‘Content-Transfer-Encoding’ header, after which a ‘set_payload’
     call will automatically encode the new payload (and add a new
     ‘Content-Transfer-Encoding’ header).

     Optional 'policy' argument defaults to *note compat32: 12bc.

     Cambiato nella versione 3.5: '_charset' also accepts *note Charset:
     ffd. instances.

     Cambiato nella versione 3.6: Added 'policy' keyword-only parameter.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/email/mime/


File: python.info,  Node: email header Internationalized headers,  Next: email charset Representing character sets,  Prev: email mime Creating email and MIME objects from scratch,  Up: email — An email and MIME handling package

5.20.1.15 ‘email.header’: Internationalized headers
...................................................

'Source code:' Lib/email/header.py(1)

__________________________________________________________________

This module is part of the legacy (‘Compat32’) email API. In the current
API encoding and decoding of headers is handled transparently by the
dictionary-like API of the *note EmailMessage: 580. class.  In addition
to uses in legacy code, this module can be useful in applications that
need to completely control the character sets used when encoding
headers.

The remaining text in this section is the original documentation of the
module.

RFC 2822(2) is the base standard that describes the format of email
messages.  It derives from the older RFC 822(3) standard which came into
widespread use at a time when most email was composed of ASCII
characters only.  RFC 2822(4) is a specification written assuming email
contains only 7-bit ASCII characters.

Of course, as email has been deployed worldwide, it has become
internationalized, such that language specific character sets can now be
used in email messages.  The base standard still requires email messages
to be transferred using only 7-bit ASCII characters, so a slew of RFCs
have been written describing how to encode email containing non-ASCII
characters into RFC 2822(5)-compliant format.  These RFCs include RFC
2045(6), RFC 2046(7), RFC 2047(8), and RFC 2231(9).  The *note email:
3f. package supports these standards in its *note email.header: 45. and
*note email.charset: 40. modules.

If you want to include non-ASCII characters in your email headers, say
in the ‘Subject’ or ‘To’ fields, you should use the *note Header: 1c46.
class and assign the field in the *note Message: 581. object to an
instance of *note Header: 1c46. instead of using a string for the header
value.  Import the *note Header: 1c46. class from the *note
email.header: 45. module.  For example:

     >>> from email.message import Message
     >>> from email.header import Header
     >>> msg = Message()
     >>> h = Header('p\xf6stal', 'iso-8859-1')
     >>> msg['Subject'] = h
     >>> msg.as_string()
     'Subject: =?iso-8859-1?q?p=F6stal?=\n\n'

Notice here how we wanted the ‘Subject’ field to contain a non-ASCII
character?  We did this by creating a *note Header: 1c46. instance and
passing in the character set that the byte string was encoded in.  When
the subsequent *note Message: 581. instance was flattened, the ‘Subject’
field was properly RFC 2047(10) encoded.  MIME-aware mail readers would
show this header using the embedded ISO-8859-1 character.

Here is the *note Header: 1c46. class description:

 -- Classe: email.header.Header (s=None, charset=None, maxlinelen=None,
          header_name=None, continuation_ws=' ', errors='strict')

     Create a MIME-compliant header that can contain strings in
     different character sets.

     Optional 's' is the initial header value.  If ‘None’ (the default),
     the initial header value is not set.  You can later append to the
     header with *note append(): 3b8c. method calls.  's' may be an
     instance of *note bytes: 192. or *note str: 169, but see the *note
     append(): 3b8c. documentation for semantics.

     Optional 'charset' serves two purposes: it has the same meaning as
     the 'charset' argument to the *note append(): 3b8c. method.  It
     also sets the default character set for all subsequent *note
     append(): 3b8c. calls that omit the 'charset' argument.  If
     'charset' is not provided in the constructor (the default), the
     ‘us-ascii’ character set is used both as 's'’s initial charset and
     as the default for subsequent *note append(): 3b8c. calls.

     The maximum line length can be specified explicitly via
     'maxlinelen'.  For splitting the first line to a shorter value (to
     account for the field header which isn’t included in 's', e.g.
     ‘Subject’) pass in the name of the field in 'header_name'.  The
     default 'maxlinelen' is 78, and the default value for 'header_name'
     is ‘None’, meaning it is not taken into account for the first line
     of a long, split header.

     Optional 'continuation_ws' must be RFC 2822(11)-compliant folding
     whitespace, and is usually either a space or a hard tab character.
     This character will be prepended to continuation lines.
     'continuation_ws' defaults to a single space character.

     Optional 'errors' is passed straight through to the *note append():
     3b8c. method.

      -- Metodo: append (s, charset=None, errors='strict')

          Append the string 's' to the MIME header.

          Optional 'charset', if given, should be a *note Charset: ffd.
          instance (see *note email.charset: 40.) or the name of a
          character set, which will be converted to a *note Charset:
          ffd. instance.  A value of ‘None’ (the default) means that the
          'charset' given in the constructor is used.

          's' may be an instance of *note bytes: 192. or *note str: 169.
          If it is an instance of *note bytes: 192, then 'charset' is
          the encoding of that byte string, and a *note UnicodeError:
          462. will be raised if the string cannot be decoded with that
          character set.

          If 's' is an instance of *note str: 169, then 'charset' is a
          hint specifying the character set of the characters in the
          string.

          In either case, when producing an RFC 2822(12)-compliant
          header using RFC 2047(13) rules, the string will be encoded
          using the output codec of the charset.  If the string cannot
          be encoded using the output codec, a UnicodeError will be
          raised.

          Optional 'errors' is passed as the errors argument to the
          decode call if 's' is a byte string.

      -- Metodo: encode (splitchars=';, \t', maxlinelen=None,
               linesep='\n')

          Encode a message header into an RFC-compliant format, possibly
          wrapping long lines and encapsulating non-ASCII parts in
          base64 or quoted-printable encodings.

          Optional 'splitchars' is a string containing characters which
          should be given extra weight by the splitting algorithm during
          normal header wrapping.  This is in very rough support of RFC
          2822(14)'s “higher level syntactic breaks”: split points
          preceded by a splitchar are preferred during line splitting,
          with the characters preferred in the order in which they
          appear in the string.  Space and tab may be included in the
          string to indicate whether preference should be given to one
          over the other as a split point when other split chars do not
          appear in the line being split.  Splitchars does not affect
          RFC 2047(15) encoded lines.

          'maxlinelen', if given, overrides the instance’s value for the
          maximum line length.

          'linesep' specifies the characters used to separate the lines
          of the folded header.  It defaults to the most useful value
          for Python application code (‘\n’), but ‘\r\n’ can be
          specified in order to produce headers with RFC-compliant line
          separators.

          Cambiato nella versione 3.2: Added the 'linesep' argument.

     The *note Header: 1c46. class also provides a number of methods to
     support standard operators and built-in functions.

      -- Metodo: __str__ ()

          Returns an approximation of the *note Header: 1c46. as a
          string, using an unlimited line length.  All pieces are
          converted to unicode using the specified encoding and joined
          together appropriately.  Any pieces with a charset of
          ‘'unknown-8bit'’ are decoded as ASCII using the ‘'replace'’
          error handler.

          Cambiato nella versione 3.2: Added handling for the
          ‘'unknown-8bit'’ charset.

      -- Metodo: __eq__ (other)

          This method allows you to compare two *note Header: 1c46.
          instances for equality.

      -- Metodo: __ne__ (other)

          This method allows you to compare two *note Header: 1c46.
          instances for inequality.

The *note email.header: 45. module also provides the following
convenient functions.

 -- Funzione: email.header.decode_header (header)

     Decode a message header value without converting the character set.
     The header value is in 'header'.

     For historical reasons, this function may return either:

       1. A list of pairs containing each of the decoded parts of the
          header, ‘(decoded_bytes, charset)’, where 'decoded_bytes' is
          always an instance of *note bytes: 192, and 'charset' is
          either:

                  - A lower case string containing the name of the
                    character set specified.

                  - ‘None’ for non-encoded parts of the header.

       2. A list of length 1 containing a pair ‘(string, None)’, where
          'string' is always an instance of *note str: 169.

     An *note email.errors.HeaderParseError: 3ac0. may be raised when
     certain decoding errors occur (e.g.  a base64 decoding exception).

     Here are examples:

          >>> from email.header import decode_header
          >>> decode_header('=?iso-8859-1?q?p=F6stal?=')
          [(b'p\xf6stal', 'iso-8859-1')]
          >>> decode_header('unencoded_string')
          [('unencoded_string', None)]
          >>> decode_header('bar =?utf-8?B?ZsOzbw==?=')
          [(b'bar ', None), (b'f\xc3\xb3o', 'utf-8')]

          Nota: This function exists for backwards compatibility only.
          For new code, we recommend using *note
          email.headerregistry.HeaderRegistry: 3b2a.

 -- Funzione: email.header.make_header (decoded_seq, maxlinelen=None,
          header_name=None, continuation_ws=' ')

     Create a *note Header: 1c46. instance from a sequence of pairs as
     returned by *note decode_header(): 12c0.

     *note decode_header(): 12c0. takes a header value string and
     returns a sequence of pairs of the format ‘(decoded_string,
     charset)’ where 'charset' is the name of the character set.

     This function takes one of those sequence of pairs and returns a
     *note Header: 1c46. instance.  Optional 'maxlinelen',
     'header_name', and 'continuation_ws' are as in the *note Header:
     1c46. constructor.

          Nota: This function exists for backwards compatibility only,
          and is not recommended for use in new code.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/email/header.py

   (2) https://datatracker.ietf.org/doc/html/rfc2822.html

   (3) https://datatracker.ietf.org/doc/html/rfc822.html

   (4) https://datatracker.ietf.org/doc/html/rfc2822.html

   (5) https://datatracker.ietf.org/doc/html/rfc2822.html

   (6) https://datatracker.ietf.org/doc/html/rfc2045.html

   (7) https://datatracker.ietf.org/doc/html/rfc2046.html

   (8) https://datatracker.ietf.org/doc/html/rfc2047.html

   (9) https://datatracker.ietf.org/doc/html/rfc2231.html

   (10) https://datatracker.ietf.org/doc/html/rfc2047.html

   (11) https://datatracker.ietf.org/doc/html/rfc2822.html

   (12) https://datatracker.ietf.org/doc/html/rfc2822.html

   (13) https://datatracker.ietf.org/doc/html/rfc2047.html

   (14) https://datatracker.ietf.org/doc/html/rfc2822.html

   (15) https://datatracker.ietf.org/doc/html/rfc2047.html


File: python.info,  Node: email charset Representing character sets,  Next: email encoders Encoders,  Prev: email header Internationalized headers,  Up: email — An email and MIME handling package

5.20.1.16 ‘email.charset’: Representing character sets
......................................................

'Source code:' Lib/email/charset.py(1)

__________________________________________________________________

This module is part of the legacy (‘Compat32’) email API. In the new API
only the aliases table is used.

The remaining text in this section is the original documentation of the
module.

This module provides a class *note Charset: ffd. for representing
character sets and character set conversions in email messages, as well
as a character set registry and several convenience methods for
manipulating this registry.  Instances of *note Charset: ffd. are used
in several other modules within the *note email: 3f. package.

Import this class from the *note email.charset: 40. module.

 -- Classe: email.charset.Charset (input_charset=DEFAULT_CHARSET)

     Map character sets to their email properties.

     This class provides information about the requirements imposed on
     email for a specific character set.  It also provides convenience
     routines for converting between character sets, given the
     availability of the applicable codecs.  Given a character set, it
     will do its best to provide information on how to use that
     character set in an email message in an RFC-compliant way.

     Certain character sets must be encoded with quoted-printable or
     base64 when used in email headers or bodies.  Certain character
     sets must be converted outright, and are not allowed in email.

     Optional 'input_charset' is as described below; it is always
     coerced to lower case.  After being alias normalized it is also
     used as a lookup into the registry of character sets to find out
     the header encoding, body encoding, and output conversion codec to
     be used for the character set.  For example, if 'input_charset' is
     ‘iso-8859-1’, then headers and bodies will be encoded using
     quoted-printable and no output conversion codec is necessary.  If
     'input_charset' is ‘euc-jp’, then headers will be encoded with
     base64, bodies will not be encoded, but output text will be
     converted from the ‘euc-jp’ character set to the ‘iso-2022-jp’
     character set.

     *note Charset: ffd. instances have the following data attributes:

      -- Attributo: input_charset

          The initial character set specified.  Common aliases are
          converted to their 'official' email names (e.g.  ‘latin_1’ is
          converted to ‘iso-8859-1’).  Defaults to 7-bit ‘us-ascii’.

      -- Attributo: header_encoding

          If the character set must be encoded before it can be used in
          an email header, this attribute will be set to ‘charset.QP’
          (for quoted-printable), ‘charset.BASE64’ (for base64
          encoding), or ‘charset.SHORTEST’ for the shortest of QP or
          BASE64 encoding.  Otherwise, it will be ‘None’.

      -- Attributo: body_encoding

          Same as 'header_encoding', but describes the encoding for the
          mail message’s body, which indeed may be different than the
          header encoding.  ‘charset.SHORTEST’ is not allowed for
          'body_encoding'.

      -- Attributo: output_charset

          Some character sets must be converted before they can be used
          in email headers or bodies.  If the 'input_charset' is one of
          them, this attribute will contain the name of the character
          set output will be converted to.  Otherwise, it will be
          ‘None’.

      -- Attributo: input_codec

          The name of the Python codec used to convert the
          'input_charset' to Unicode.  If no conversion codec is
          necessary, this attribute will be ‘None’.

      -- Attributo: output_codec

          The name of the Python codec used to convert Unicode to the
          'output_charset'.  If no conversion codec is necessary, this
          attribute will have the same value as the 'input_codec'.

     *note Charset: ffd. instances also have the following methods:

      -- Metodo: get_body_encoding ()

          Return the content transfer encoding used for body encoding.

          This is either the string ‘quoted-printable’ or ‘base64’
          depending on the encoding used, or it is a function, in which
          case you should call the function with a single argument, the
          Message object being encoded.  The function should then set
          the ‘Content-Transfer-Encoding’ header itself to whatever is
          appropriate.

          Returns the string ‘quoted-printable’ if 'body_encoding' is
          ‘QP’, returns the string ‘base64’ if 'body_encoding' is
          ‘BASE64’, and returns the string ‘7bit’ otherwise.

      -- Metodo: get_output_charset ()

          Return the output character set.

          This is the 'output_charset' attribute if that is not ‘None’,
          otherwise it is 'input_charset'.

      -- Metodo: header_encode (string)

          Header-encode the string 'string'.

          The type of encoding (base64 or quoted-printable) will be
          based on the 'header_encoding' attribute.

      -- Metodo: header_encode_lines (string, maxlengths)

          Header-encode a 'string' by converting it first to bytes.

          This is similar to *note header_encode(): 3b9c. except that
          the string is fit into maximum line lengths as given by the
          argument 'maxlengths', which must be an iterator: each element
          returned from this iterator will provide the next maximum line
          length.

      -- Metodo: body_encode (string)

          Body-encode the string 'string'.

          The type of encoding (base64 or quoted-printable) will be
          based on the 'body_encoding' attribute.

     The *note Charset: ffd. class also provides a number of methods to
     support standard operations and built-in functions.

      -- Metodo: __str__ ()

          Returns 'input_charset' as a string coerced to lower case.
          ‘__repr__()’ is an alias for ‘__str__()’.

      -- Metodo: __eq__ (other)

          This method allows you to compare two *note Charset: ffd.
          instances for equality.

      -- Metodo: __ne__ (other)

          This method allows you to compare two *note Charset: ffd.
          instances for inequality.

The *note email.charset: 40. module also provides the following
functions for adding new entries to the global character set, alias, and
codec registries:

 -- Funzione: email.charset.add_charset (charset, header_enc=None,
          body_enc=None, output_charset=None)

     Add character properties to the global registry.

     'charset' is the input character set, and must be the canonical
     name of a character set.

     Optional 'header_enc' and 'body_enc' is either ‘charset.QP’ for
     quoted-printable, ‘charset.BASE64’ for base64 encoding,
     ‘charset.SHORTEST’ for the shortest of quoted-printable or base64
     encoding, or ‘None’ for no encoding.  ‘SHORTEST’ is only valid for
     'header_enc'.  The default is ‘None’ for no encoding.

     Optional 'output_charset' is the character set that the output
     should be in.  Conversions will proceed from input charset, to
     Unicode, to the output charset when the method ‘Charset.convert()’
     is called.  The default is to output in the same character set as
     the input.

     Both 'input_charset' and 'output_charset' must have Unicode codec
     entries in the module’s character set-to-codec mapping; use *note
     add_codec(): 3ba3. to add codecs the module does not know about.
     See the *note codecs: 1c. module’s documentation for more
     information.

     The global character set registry is kept in the module global
     dictionary ‘CHARSETS’.

 -- Funzione: email.charset.add_alias (alias, canonical)

     Add a character set alias.  'alias' is the alias name, e.g.
     ‘latin-1’.  'canonical' is the character set’s canonical name, e.g.
     ‘iso-8859-1’.

     The global charset alias registry is kept in the module global
     dictionary ‘ALIASES’.

 -- Funzione: email.charset.add_codec (charset, codecname)

     Add a codec that map characters in the given character set to and
     from Unicode.

     'charset' is the canonical name of a character set.  'codecname' is
     the name of a Python codec, as appropriate for the second argument
     to the *note str: 169.’s *note encode(): ad4. method.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/email/charset.py


File: python.info,  Node: email encoders Encoders,  Next: email utils Miscellaneous utilities,  Prev: email charset Representing character sets,  Up: email — An email and MIME handling package

5.20.1.17 ‘email.encoders’: Encoders
....................................

'Source code:' Lib/email/encoders.py(1)

__________________________________________________________________

This module is part of the legacy (‘Compat32’) email API. In the new API
the functionality is provided by the 'cte' parameter of the *note
set_content(): 1c45. method.

This module is deprecated in Python 3.  The functions provided here
should not be called explicitly since the *note MIMEText: ffc. class
sets the content type and CTE header using the '_subtype' and '_charset'
values passed during the instantiation of that class.

The remaining text in this section is the original documentation of the
module.

When creating *note Message: 581. objects from scratch, you often need
to encode the payloads for transport through compliant mail servers.
This is especially true for ‘image/*’ and ‘text/*’ type messages
containing binary data.

The *note email: 3f. package provides some convenient encoders in its
*note encoders: 42. module.  These encoders are actually used by the
*note MIMEAudio: 3b87. and *note MIMEImage: 3b1a. class constructors to
provide default encodings.  All encoder functions take exactly one
argument, the message object to encode.  They usually extract the
payload, encode it, and reset the payload to this newly encoded value.
They should also set the ‘Content-Transfer-Encoding’ header as
appropriate.

Note that these functions are not meaningful for a multipart message.
They must be applied to individual subparts instead, and will raise a
*note TypeError: 198. if passed a message whose type is multipart.

Here are the encoding functions provided:

 -- Funzione: email.encoders.encode_quopri (msg)

     Encodes the payload into quoted-printable form and sets the
     ‘Content-Transfer-Encoding’ header to ‘quoted-printable’ (2).  This
     is a good encoding to use when most of your payload is normal
     printable data, but contains a few unprintable characters.

 -- Funzione: email.encoders.encode_base64 (msg)

     Encodes the payload into base64 form and sets the
     ‘Content-Transfer-Encoding’ header to ‘base64’.  This is a good
     encoding to use when most of your payload is unprintable data since
     it is a more compact form than quoted-printable.  The drawback of
     base64 encoding is that it renders the text non-human readable.

 -- Funzione: email.encoders.encode_7or8bit (msg)

     This doesn’t actually modify the message’s payload, but it does set
     the ‘Content-Transfer-Encoding’ header to either ‘7bit’ or ‘8bit’
     as appropriate, based on the payload data.

 -- Funzione: email.encoders.encode_noop (msg)

     This does nothing; it doesn’t even set the
     ‘Content-Transfer-Encoding’ header.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/email/encoders.py

   (2) Note that encoding with *note encode_quopri(): 3ba8. also encodes
all tabs and space characters in the data.


File: python.info,  Node: email utils Miscellaneous utilities,  Next: email iterators Iterators,  Prev: email encoders Encoders,  Up: email — An email and MIME handling package

5.20.1.18 ‘email.utils’: Miscellaneous utilities
................................................

'Source code:' Lib/email/utils.py(1)

__________________________________________________________________

There are a couple of useful utilities provided in the *note
email.utils: 54. module:

 -- Funzione: email.utils.localtime (dt=None)

     Return local time as an aware datetime object.  If called without
     arguments, return current time.  Otherwise 'dt' argument should be
     a *note datetime: 4e3. instance, and it is converted to the local
     time zone according to the system time zone database.  If 'dt' is
     naive (that is, ‘dt.tzinfo’ is ‘None’), it is assumed to be in
     local time.

     Added in version 3.3.

     Deprecated since version 3.12, removed in version 3.14: The 'isdst'
     parameter.

 -- Funzione: email.utils.make_msgid (idstring=None, domain=None)

     Returns a string suitable for an RFC 2822(2)-compliant ‘Message-ID’
     header.  Optional 'idstring' if given, is a string used to
     strengthen the uniqueness of the message id.  Optional 'domain' if
     given provides the portion of the msgid after the “@”.  The default
     is the local hostname.  It is not normally necessary to override
     this default, but may be useful certain cases, such as a
     constructing distributed system that uses a consistent domain name
     across multiple hosts.

     Cambiato nella versione 3.2: Added the 'domain' keyword.

The remaining functions are part of the legacy (‘Compat32’) email API.
There is no need to directly use these with the new API, since the
parsing and formatting they provide is done automatically by the header
parsing machinery of the new API.

 -- Funzione: email.utils.quote (str)

     Return a new string with backslashes in 'str' replaced by two
     backslashes, and double quotes replaced by backslash-double quote.

 -- Funzione: email.utils.unquote (str)

     Return a new string which is an 'unquoted' version of 'str'.  If
     'str' ends and begins with double quotes, they are stripped off.
     Likewise if 'str' ends and begins with angle brackets, they are
     stripped off.

 -- Funzione: email.utils.parseaddr (address, *, strict=True)

     Parse address – which should be the value of some
     address-containing field such as ‘To’ or ‘Cc’ – into its
     constituent 'realname' and 'email address' parts.  Returns a tuple
     of that information, unless the parse fails, in which case a
     2-tuple of ‘('', '')’ is returned.

     If 'strict' is true, use a strict parser which rejects malformed
     inputs.

     Cambiato nella versione 3.13: Add 'strict' optional parameter and
     reject malformed inputs by default.

 -- Funzione: email.utils.formataddr (pair, charset='utf-8')

     The inverse of *note parseaddr(): 4f5, this takes a 2-tuple of the
     form ‘(realname, email_address)’ and returns the string value
     suitable for a ‘To’ or ‘Cc’ header.  If the first element of 'pair'
     is false, then the second element is returned unmodified.

     Optional 'charset' is the character set that will be used in the
     RFC 2047(3) encoding of the ‘realname’ if the ‘realname’ contains
     non-ASCII characters.  Can be an instance of *note str: 169. or a
     *note Charset: ffd.  Defaults to ‘utf-8’.

     Cambiato nella versione 3.3: Added the 'charset' option.

 -- Funzione: email.utils.getaddresses (fieldvalues, *, strict=True)

     This method returns a list of 2-tuples of the form returned by
     ‘parseaddr()’.  'fieldvalues' is a sequence of header field values
     as might be returned by *note Message.get_all: 3b68.

     If 'strict' is true, use a strict parser which rejects malformed
     inputs.

     Here’s a simple example that gets all the recipients of a message:

          from email.utils import getaddresses

          tos = msg.get_all('to', [])
          ccs = msg.get_all('cc', [])
          resent_tos = msg.get_all('resent-to', [])
          resent_ccs = msg.get_all('resent-cc', [])
          all_recipients = getaddresses(tos + ccs + resent_tos + resent_ccs)

     Cambiato nella versione 3.13: Add 'strict' optional parameter and
     reject malformed inputs by default.

 -- Funzione: email.utils.parsedate (date)

     Attempts to parse a date according to the rules in RFC 2822(4).
     however, some mailers don’t follow that format as specified, so
     *note parsedate(): 3bb1. tries to guess correctly in such cases.
     'date' is a string containing an RFC 2822(5) date, such as ‘"Mon,
     20 Nov 1995 19:12:08 -0500"’.  If it succeeds in parsing the date,
     *note parsedate(): 3bb1. returns a 9-tuple that can be passed
     directly to *note time.mktime(): 13f0.; otherwise ‘None’ will be
     returned.  Note that indexes 6, 7, and 8 of the result tuple are
     not usable.

 -- Funzione: email.utils.parsedate_tz (date)

     Performs the same function as *note parsedate(): 3bb1, but returns
     either ‘None’ or a 10-tuple; the first 9 elements make up a tuple
     that can be passed directly to *note time.mktime(): 13f0, and the
     tenth is the offset of the date’s timezone from UTC (which is the
     official term for Greenwich Mean Time) (6).  If the input string
     has no timezone, the last element of the tuple returned is ‘0’,
     which represents UTC. Note that indexes 6, 7, and 8 of the result
     tuple are not usable.

 -- Funzione: email.utils.parsedate_to_datetime (date)

     The inverse of *note format_datetime(): 12c5.  Performs the same
     function as *note parsedate(): 3bb1, but on success returns a *note
     datetime: 4e3.; otherwise ‘ValueError’ is raised if 'date' contains
     an invalid value such as an hour greater than 23 or a timezone
     offset not between -24 and 24 hours.  If the input date has a
     timezone of ‘-0000’, the ‘datetime’ will be a naive ‘datetime’, and
     if the date is conforming to the RFCs it will represent a time in
     UTC but with no indication of the actual source timezone of the
     message the date comes from.  If the input date has any other valid
     timezone offset, the ‘datetime’ will be an aware ‘datetime’ with
     the corresponding a *note timezone: 12c7. *note tzinfo: 7f7.

     Added in version 3.3.

 -- Funzione: email.utils.mktime_tz (tuple)

     Turn a 10-tuple as returned by *note parsedate_tz(): 1c0b. into a
     UTC timestamp (seconds since the Epoch).  If the timezone item in
     the tuple is ‘None’, assume local time.

 -- Funzione: email.utils.formatdate (timeval=None, localtime=False,
          usegmt=False)

     Returns a date string as per RFC 2822(7), e.g.:

          Fri, 09 Nov 2001 01:08:47 -0000

     Optional 'timeval' if given is a floating-point time value as
     accepted by *note time.gmtime(): 13c8. and *note time.localtime():
     1700, otherwise the current time is used.

     Optional 'localtime' is a flag that when ‘True’, interprets
     'timeval', and returns a date relative to the local timezone
     instead of UTC, properly taking daylight savings time into account.
     The default is ‘False’ meaning UTC is used.

     Optional 'usegmt' is a flag that when ‘True’, outputs a date string
     with the timezone as an ascii string ‘GMT’, rather than a numeric
     ‘-0000’.  This is needed for some protocols (such as HTTP). This
     only applies when 'localtime' is ‘False’.  The default is ‘False’.

 -- Funzione: email.utils.format_datetime (dt, usegmt=False)

     Like ‘formatdate’, but the input is a *note datetime: 34. instance.
     If it is a naive datetime, it is assumed to be «UTC with no
     information about the source timezone», and the conventional
     ‘-0000’ is used for the timezone.  If it is an aware ‘datetime’,
     then the numeric timezone offset is used.  If it is an aware
     timezone with offset zero, then 'usegmt' may be set to ‘True’, in
     which case the string ‘GMT’ is used instead of the numeric timezone
     offset.  This provides a way to generate standards conformant HTTP
     date headers.

     Added in version 3.3.

 -- Funzione: email.utils.decode_rfc2231 (s)

     Decode the string 's' according to RFC 2231(8).

 -- Funzione: email.utils.encode_rfc2231 (s, charset=None,
          language=None)

     Encode the string 's' according to RFC 2231(9).  Optional 'charset'
     and 'language', if given is the character set name and language
     name to use.  If neither is given, 's' is returned as-is.  If
     'charset' is given but 'language' is not, the string is encoded
     using the empty string for 'language'.

 -- Funzione: email.utils.collapse_rfc2231_value (value,
          errors='replace', fallback_charset='us-ascii')

     When a header parameter is encoded in RFC 2231(10) format, *note
     Message.get_param: 3b74. may return a 3-tuple containing the
     character set, language, and value.  *note
     collapse_rfc2231_value(): 3b75. turns this into a unicode string.
     Optional 'errors' is passed to the 'errors' argument of *note str:
     169.’s *note encode(): ad4. method; it defaults to ‘'replace'’.
     Optional 'fallback_charset' specifies the character set to use if
     the one in the RFC 2231(11) header is not known by Python; it
     defaults to ‘'us-ascii'’.

     For convenience, if the 'value' passed to *note
     collapse_rfc2231_value(): 3b75. is not a tuple, it should be a
     string and it is returned unquoted.

 -- Funzione: email.utils.decode_params (params)

     Decode parameters list according to RFC 2231(12).  'params' is a
     sequence of 2-tuples containing elements of the form
     ‘(content-type, string-value)’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/email/utils.py

   (2) https://datatracker.ietf.org/doc/html/rfc2822.html

   (3) https://datatracker.ietf.org/doc/html/rfc2047.html

   (4) https://datatracker.ietf.org/doc/html/rfc2822.html

   (5) https://datatracker.ietf.org/doc/html/rfc2822.html

   (6) Note that the sign of the timezone offset is the opposite of the
sign of the ‘time.timezone’ variable for the same timezone; the latter
variable follows the POSIX standard while this module follows RFC 2822
(https://datatracker.ietf.org/doc/html/rfc2822.html).

   (7) https://datatracker.ietf.org/doc/html/rfc2822.html

   (8) https://datatracker.ietf.org/doc/html/rfc2231.html

   (9) https://datatracker.ietf.org/doc/html/rfc2231.html

   (10) https://datatracker.ietf.org/doc/html/rfc2231.html

   (11) https://datatracker.ietf.org/doc/html/rfc2231.html

   (12) https://datatracker.ietf.org/doc/html/rfc2231.html


File: python.info,  Node: email iterators Iterators,  Prev: email utils Miscellaneous utilities,  Up: email — An email and MIME handling package

5.20.1.19 ‘email.iterators’: Iterators
......................................

'Source code:' Lib/email/iterators.py(1)

__________________________________________________________________

Iterating over a message object tree is fairly easy with the *note
Message.walk: 3b7d. method.  The *note email.iterators: 47. module
provides some useful higher level iterations over message object trees.

 -- Funzione: email.iterators.body_line_iterator (msg, decode=False)

     This iterates over all the payloads in all the subparts of 'msg',
     returning the string payloads line-by-line.  It skips over all the
     subpart headers, and it skips over any subpart with a payload that
     isn’t a Python string.  This is somewhat equivalent to reading the
     flat text representation of the message from a file using *note
     readline(): 2090, skipping over all the intervening headers.

     Optional 'decode' is passed through to *note Message.get_payload:
     13d5.

 -- Funzione: email.iterators.typed_subpart_iterator (msg,
          maintype='text', subtype=None)

     This iterates over all the subparts of 'msg', returning only those
     subparts that match the MIME type specified by 'maintype' and
     'subtype'.

     Note that 'subtype' is optional; if omitted, then subpart MIME type
     matching is done only with the main type.  'maintype' is optional
     too; it defaults to ‘text’.

     Thus, by default *note typed_subpart_iterator(): 3bb9. returns each
     subpart that has a MIME type of ‘text/*’.

The following function has been added as a useful debugging tool.  It
should 'not' be considered part of the supported public interface for
the package.

 -- Funzione: email.iterators._structure (msg, fp=None, level=0,
          include_default=False)

     Prints an indented representation of the content types of the
     message object structure.  For example:

          >>> msg = email.message_from_file(somefile)
          >>> _structure(msg)
          multipart/mixed
              text/plain
              text/plain
              multipart/digest
                  message/rfc822
                      text/plain
                  message/rfc822
                      text/plain
                  message/rfc822
                      text/plain
                  message/rfc822
                      text/plain
                  message/rfc822
                      text/plain
              text/plain

     Optional 'fp' is a file-like object to print the output to.  It
     must be suitable for Python’s *note print(): 1177. function.
     'level' is used internally.  'include_default', if true, prints the
     default type as well.

Vedi anche
..........

Module *note smtplib: cf.

     SMTP (Simple Mail Transport Protocol) client

Module *note poplib: b1.

     POP (Post Office Protocol) client

Module *note imaplib: 78.

     IMAP (Internet Message Access Protocol) client

Module *note mailbox: 8f.

     Tools for creating, reading, and managing collections of messages
     on disk using a variety standard formats.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/email/iterators.py


File: python.info,  Node: json — JSON encoder and decoder,  Next: mailbox — Manipulate mailboxes in various formats,  Prev: email — An email and MIME handling package,  Up: Internet Data Handling

5.20.2 ‘json’ — JSON encoder and decoder
----------------------------------------

'Source code:' Lib/json/__init__.py(1)

__________________________________________________________________

JSON (JavaScript Object Notation)(2), specified by RFC 7159(3) (which
obsoletes RFC 4627(4)) and by ECMA-404(5), is a lightweight data
interchange format inspired by JavaScript(6) object literal syntax
(although it is not a strict subset of JavaScript (7) ).

     Nota: The term «object» in the context of JSON processing in Python
     can be ambiguous.  All values in Python are objects.  In JSON, an
     object refers to any data wrapped in curly braces, similar to a
     Python dictionary.

     Avvertimento: Be cautious when parsing JSON data from untrusted
     sources.  A malicious JSON string may cause the decoder to consume
     considerable CPU and memory resources.  Limiting the size of data
     to be parsed is recommended.

This module exposes an API familiar to users of the standard library
*note marshal: 91. and *note pickle: ab. modules.

Encoding basic Python object hierarchies:

     >>> import json
     >>> json.dumps(['foo', {'bar': ('baz', None, 1.0, 2)}])
     '["foo", {"bar": ["baz", null, 1.0, 2]}]'
     >>> print(json.dumps("\"foo\bar"))
     "\"foo\bar"
     >>> print(json.dumps('\u1234'))
     "\u1234"
     >>> print(json.dumps('\\'))
     "\\"
     >>> print(json.dumps({"c": 0, "b": 0, "a": 0}, sort_keys=True))
     {"a": 0, "b": 0, "c": 0}
     >>> from io import StringIO
     >>> io = StringIO()
     >>> json.dump(['streaming API'], io)
     >>> io.getvalue()
     '["streaming API"]'

Compact encoding:

     >>> import json
     >>> json.dumps([1, 2, 3, {'4': 5, '6': 7}], separators=(',', ':'))
     '[1,2,3,{"4":5,"6":7}]'

Pretty printing:

     >>> import json
     >>> print(json.dumps({'6': 7, '4': 5}, sort_keys=True, indent=4))
     {
         "4": 5,
         "6": 7
     }

Customizing JSON object encoding:

     >>> import json
     >>> def custom_json(obj):
     ...     if isinstance(obj, complex):
     ...         return {'__complex__': True, 'real': obj.real, 'imag': obj.imag}
     ...     raise TypeError(f'Cannot serialize object of {type(obj)}')
     ...
     >>> json.dumps(1 + 2j, default=custom_json)
     '{"__complex__": true, "real": 1.0, "imag": 2.0}'

Decoding JSON:

     >>> import json
     >>> json.loads('["foo", {"bar":["baz", null, 1.0, 2]}]')
     ['foo', {'bar': ['baz', None, 1.0, 2]}]
     >>> json.loads('"\\"foo\\bar"')
     '"foo\x08ar'
     >>> from io import StringIO
     >>> io = StringIO('["streaming API"]')
     >>> json.load(io)
     ['streaming API']

Customizing JSON object decoding:

     >>> import json
     >>> def as_complex(dct):
     ...     if '__complex__' in dct:
     ...         return complex(dct['real'], dct['imag'])
     ...     return dct
     ...
     >>> json.loads('{"__complex__": true, "real": 1, "imag": 2}',
     ...     object_hook=as_complex)
     (1+2j)
     >>> import decimal
     >>> json.loads('1.1', parse_float=decimal.Decimal)
     Decimal('1.1')

Extending *note JSONEncoder: f44.:

     >>> import json
     >>> class ComplexEncoder(json.JSONEncoder):
     ...     def default(self, obj):
     ...         if isinstance(obj, complex):
     ...             return [obj.real, obj.imag]
     ...         # Let the base class default method raise the TypeError
     ...         return super().default(obj)
     ...
     >>> json.dumps(2 + 1j, cls=ComplexEncoder)
     '[2.0, 1.0]'
     >>> ComplexEncoder().encode(2 + 1j)
     '[2.0, 1.0]'
     >>> list(ComplexEncoder().iterencode(2 + 1j))
     ['[2.0', ', 1.0', ']']

Using *note json: 86. from the shell to validate and pretty-print:

     $ echo '{"json":"obj"}' | python -m json
     {
         "json": "obj"
     }
     $ echo '{1.2:3.4}' | python -m json
     Expecting property name enclosed in double quotes: line 1 column 2 (char 1)

See *note Command-line interface: 23e. for detailed documentation.

     Nota: JSON is a subset of YAML(8) 1.2.  The JSON produced by this
     module’s default settings (in particular, the default 'separators'
     value) is also a subset of YAML 1.0 and 1.1.  This module can thus
     also be used as a YAML serializer.

     Nota: This module’s encoders and decoders preserve input and output
     order by default.  Order is only lost if the underlying containers
     are unordered.

* Menu:

* Basic Usage::
* Encoders and Decoders::
* Exceptions: Exceptions<19>.
* Standard Compliance and Interoperability::
* Command-line interface: Command-line interface<5>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/json/__init__.py

   (2) https://json.org

   (3) https://datatracker.ietf.org/doc/html/rfc7159.html

   (4) https://datatracker.ietf.org/doc/html/rfc4627.html

   (5) 
https://ecma-international.org/publications-and-standards/standards/ecma-404/

   (6) https://en.wikipedia.org/wiki/JavaScript

   (7) As noted in the errata for RFC 7159
(https://www.rfc-editor.org/errata_search.php?rfc=7159), JSON permits
literal U+2028 (LINE SEPARATOR) and U+2029 (PARAGRAPH SEPARATOR)
characters in strings, whereas JavaScript (as of ECMAScript Edition 5.1)
does not.

   (8) https://yaml.org/


File: python.info,  Node: Basic Usage,  Next: Encoders and Decoders,  Up: json — JSON encoder and decoder

5.20.2.1 Basic Usage
....................

 -- Funzione: json.dump (obj, fp, *, skipkeys=False, ensure_ascii=True,
          check_circular=True, allow_nan=True, cls=None, indent=None,
          separators=None, default=None, sort_keys=False, **kw)

     Serialize 'obj' as a JSON formatted stream to 'fp' (a
     ‘.write()’-supporting *note file-like object: 1794.) using this
     *note Python-to-JSON conversion table: 3bbf.

          Nota: Unlike *note pickle: ab. and *note marshal: 91, JSON is
          not a framed protocol, so trying to serialize multiple objects
          with repeated calls to *note dump(): f42. using the same 'fp'
          will result in an invalid JSON file.


     Parametri:

        * ‘obj’ (*note object: c80.) – The Python object to be
          serialized.

        * ‘fp’ (*note file-like object: 1794.) – The file-like object
          'obj' will be serialized to.  The ‘json’ module always
          produces *note str: 169. objects, not *note bytes: 192.
          objects, therefore ‘fp.write()’ must support *note str: 169.
          input.

        * ‘skipkeys’ (*note bool: 3c3.) – If ‘True’, keys that are not
          of a basic type (*note str: 169, *note int: 19b, *note float:
          196, *note bool: 3c3, ‘None’) will be skipped instead of
          raising a *note TypeError: 198.  Default ‘False’.

        * ‘ensure_ascii’ (*note bool: 3c3.) – If ‘True’ (the default),
          the output is guaranteed to have all incoming non-ASCII and
          non-printable characters escaped.  If ‘False’, all characters
          will be outputted as-is, except for the characters that must
          be escaped: quotation mark, reverse solidus, and the control
          characters U+0000 through U+001F.

        * ‘check_circular’ (*note bool: 3c3.) – If ‘False’, the circular
          reference check for container types is skipped and a circular
          reference will result in a *note RecursionError: f6a. (or
          worse).  Default ‘True’.

        * ‘allow_nan’ (*note bool: 3c3.) – If ‘False’, serialization of
          out-of-range *note float: 196. values (‘nan’, ‘inf’, ‘-inf’)
          will result in a *note ValueError: 2ec, in strict compliance
          with the JSON specification.  If ‘True’ (the default), their
          JavaScript equivalents (‘NaN’, ‘Infinity’, ‘-Infinity’) are
          used.

        * ‘cls’ (a *note JSONEncoder: f44. subclass) – If set, a custom
          JSON encoder with the *note default(): 3bc0. method
          overridden, for serializing into custom datatypes.  If ‘None’
          (the default), ‘JSONEncoder’ is used.

        * ‘indent’ (*note int: 19b.‘ | ’*note str: 169.‘ | ’‘None’) – If
          a positive integer or string, JSON array elements and object
          members will be pretty-printed with that indent level.  A
          positive integer indents that many spaces per level; a string
          (such as ‘"\t"’) is used to indent each level.  If zero,
          negative, or ‘""’ (the empty string), only newlines are
          inserted.  If ‘None’ (the default), the most compact
          representation is used.

        * ‘separators’ (*note tuple: 614.‘ | ’‘None’) – A two-tuple:
          ‘(item_separator, key_separator)’.  If ‘None’ (the default),
          'separators' defaults to ‘(', ', ': ')’ if 'indent' is ‘None’,
          and ‘(',', ': ')’ otherwise.  For the most compact JSON,
          specify ‘(',', ':')’ to eliminate whitespace.

        * ‘default’ (*note callable: 2d61. | None) – A function that is
          called for objects that can’t otherwise be serialized.  It
          should return a JSON encodable version of the object or raise
          a *note TypeError: 198.  If ‘None’ (the default), ‘TypeError’
          is raised.

        * ‘sort_keys’ (*note bool: 3c3.) – If ‘True’, dictionaries will
          be outputted sorted by key.  Default ‘False’.

     Cambiato nella versione 3.2: Allow strings for 'indent' in addition
     to integers.

     Cambiato nella versione 3.4: Use ‘(',', ': ')’ as default if
     'indent' is not ‘None’.

     Cambiato nella versione 3.6: All optional parameters are now *note
     keyword-only: 5a5.

 -- Funzione: json.dumps (obj, *, skipkeys=False, ensure_ascii=True,
          check_circular=True, allow_nan=True, cls=None, indent=None,
          separators=None, default=None, sort_keys=False, **kw)

     Serialize 'obj' to a JSON formatted *note str: 169. using this
     *note conversion table: 3bbf.  The arguments have the same meaning
     as in *note dump(): f42.

          Nota: Keys in key/value pairs of JSON are always of the type
          *note str: 169.  When a dictionary is converted into JSON, all
          the keys of the dictionary are coerced to strings.  As a
          result of this, if a dictionary is converted into JSON and
          then back into a dictionary, the dictionary may not equal the
          original one.  That is, ‘loads(dumps(x)) != x’ if x has
          non-string keys.

 -- Funzione: json.load (fp, *, cls=None, object_hook=None,
          parse_float=None, parse_int=None, parse_constant=None,
          object_pairs_hook=None, **kw)

     Deserialize 'fp' to a Python object using the *note JSON-to-Python
     conversion table: 3bc1.


     Parametri:

        * ‘fp’ (*note file-like object: 1794.) – A ‘.read()’-supporting
          *note text file: 2057. or *note binary file: 2058. containing
          the JSON document to be deserialized.

        * ‘cls’ (a *note JSONDecoder: f45. subclass) – If set, a custom
          JSON decoder.  Additional keyword arguments to ‘load()’ will
          be passed to the constructor of 'cls'.  If ‘None’ (the
          default), ‘JSONDecoder’ is used.

        * ‘object_hook’ (*note callable: 2d61. | None) – If set, a
          function that is called with the result of any JSON object
          literal decoded (a *note dict: 183.).  The return value of
          this function will be used instead of the *note dict: 183.
          This feature can be used to implement custom decoders, for
          example JSON-RPC(1) class hinting.  Default ‘None’.

        * ‘object_pairs_hook’ (*note callable: 2d61. | None) – If set, a
          function that is called with the result of any JSON object
          literal decoded with an ordered list of pairs.  The return
          value of this function will be used instead of the *note dict:
          183.  This feature can be used to implement custom decoders.
          If 'object_hook' is also set, 'object_pairs_hook' takes
          priority.  Default ‘None’.

        * ‘parse_float’ (*note callable: 2d61. | None) – If set, a
          function that is called with the string of every JSON float to
          be decoded.  If ‘None’ (the default), it is equivalent to
          ‘float(num_str)’.  This can be used to parse JSON floats into
          custom datatypes, for example *note decimal.Decimal: 1fe.

        * ‘parse_int’ (*note callable: 2d61. | None) – If set, a
          function that is called with the string of every JSON int to
          be decoded.  If ‘None’ (the default), it is equivalent to
          ‘int(num_str)’.  This can be used to parse JSON integers into
          custom datatypes, for example *note float: 196.

        * ‘parse_constant’ (*note callable: 2d61. | None) – If set, a
          function that is called with one of the following strings:
          ‘'-Infinity'’, ‘'Infinity'’, or ‘'NaN'’.  This can be used to
          raise an exception if invalid JSON numbers are encountered.
          Default ‘None’.


     Solleva:

        * *note JSONDecodeError: 1024. – When the data being
          deserialized is not a valid JSON document.

        * *note UnicodeDecodeError: c0a. – When the data being
          deserialized does not contain UTF-8, UTF-16 or UTF-32 encoded
          data.

     Cambiato nella versione 3.1:

        * Added the optional 'object_pairs_hook' parameter.

        * 'parse_constant' doesn’t get called on “null”, “true”, “false”
          anymore.

     Cambiato nella versione 3.6:

        * All optional parameters are now *note keyword-only: 5a5.

        * 'fp' can now be a *note binary file: 2058.  The input encoding
          should be UTF-8, UTF-16 or UTF-32.

     Cambiato nella versione 3.11: The default 'parse_int' of *note
     int(): 19b. now limits the maximum length of the integer string via
     the interpreter’s *note integer string conversion length
     limitation: 80c. to help avoid denial of service attacks.

 -- Funzione: json.loads (s, *, cls=None, object_hook=None,
          parse_float=None, parse_int=None, parse_constant=None,
          object_pairs_hook=None, **kw)

     Identical to *note load(): eb4, but instead of a file-like object,
     deserialize 's' (a *note str: 169, *note bytes: 192. or *note
     bytearray: 344. instance containing a JSON document) to a Python
     object using this *note conversion table: 3bc1.

     Cambiato nella versione 3.6: 's' can now be of type *note bytes:
     192. or *note bytearray: 344.  The input encoding should be UTF-8,
     UTF-16 or UTF-32.

     Cambiato nella versione 3.9: The keyword argument 'encoding' has
     been removed.

   ---------- Footnotes ----------

   (1) https://www.jsonrpc.org


File: python.info,  Node: Encoders and Decoders,  Next: Exceptions<19>,  Prev: Basic Usage,  Up: json — JSON encoder and decoder

5.20.2.2 Encoders and Decoders
..............................

 -- Classe: json.JSONDecoder (*, object_hook=None, parse_float=None,
          parse_int=None, parse_constant=None, strict=True,
          object_pairs_hook=None)

     Simple JSON decoder.

     Performs the following translations in decoding by default:

     JSON                Python
                         
     --------------------------------------------
                         
     object              dict
                         
                         
     array               list
                         
                         
     string              str
                         
                         
     number (int)        int
                         
                         
     number (real)       float
                         
                         
     true                True
                         
                         
     false               False
                         
                         
     null                None
                         

     It also understands ‘NaN’, ‘Infinity’, and ‘-Infinity’ as their
     corresponding ‘float’ values, which is outside the JSON spec.

     'object_hook' is an optional function that will be called with the
     result of every JSON object decoded and its return value will be
     used in place of the given *note dict: 183.  This can be used to
     provide custom deserializations (e.g.  to support JSON-RPC(1) class
     hinting).

     'object_pairs_hook' is an optional function that will be called
     with the result of every JSON object decoded with an ordered list
     of pairs.  The return value of 'object_pairs_hook' will be used
     instead of the *note dict: 183.  This feature can be used to
     implement custom decoders.  If 'object_hook' is also defined, the
     'object_pairs_hook' takes priority.

     Cambiato nella versione 3.1: Added support for 'object_pairs_hook'.

     'parse_float' is an optional function that will be called with the
     string of every JSON float to be decoded.  By default, this is
     equivalent to ‘float(num_str)’.  This can be used to use another
     datatype or parser for JSON floats (e.g.  *note decimal.Decimal:
     1fe.).

     'parse_int' is an optional function that will be called with the
     string of every JSON int to be decoded.  By default, this is
     equivalent to ‘int(num_str)’.  This can be used to use another
     datatype or parser for JSON integers (e.g.  *note float: 196.).

     'parse_constant' is an optional function that will be called with
     one of the following strings: ‘'-Infinity'’, ‘'Infinity'’, ‘'NaN'’.
     This can be used to raise an exception if invalid JSON numbers are
     encountered.

     If 'strict' is false (‘True’ is the default), then control
     characters will be allowed inside strings.  Control characters in
     this context are those with character codes in the 0–31 range,
     including ‘'\t'’ (tab), ‘'\n'’, ‘'\r'’ and ‘'\0'’.

     If the data being deserialized is not a valid JSON document, a
     *note JSONDecodeError: 1024. will be raised.

     Cambiato nella versione 3.6: All parameters are now *note
     keyword-only: 5a5.

      -- Metodo: decode (s)

          Return the Python representation of 's' (a *note str: 169.
          instance containing a JSON document).

          *note JSONDecodeError: 1024. will be raised if the given JSON
          document is not valid.

      -- Metodo: raw_decode (s)

          Decode a JSON document from 's' (a *note str: 169. beginning
          with a JSON document) and return a 2-tuple of the Python
          representation and the index in 's' where the document ended.

          This can be used to decode a JSON document from a string that
          may have extraneous data at the end.

 -- Classe: json.JSONEncoder (*, skipkeys=False, ensure_ascii=True,
          check_circular=True, allow_nan=True, sort_keys=False,
          indent=None, separators=None, default=None)

     Extensible JSON encoder for Python data structures.

     Supports the following objects and types by default:

     Python                                       JSON
                                                  
     -----------------------------------------------------------------
                                                  
     dict                                         object
                                                  
                                                  
     list, tuple                                  array
                                                  
                                                  
     str                                          string
                                                  
                                                  
     int, float, int- & float-derived Enums       number
                                                  
                                                  
     True                                         true
                                                  
                                                  
     False                                        false
                                                  
                                                  
     None                                         null
                                                  

     Cambiato nella versione 3.4: Added support for int- and
     float-derived Enum classes.

     To extend this to recognize other objects, subclass and implement a
     *note default(): 3bc0. method with another method that returns a
     serializable object for ‘o’ if possible, otherwise it should call
     the superclass implementation (to raise *note TypeError: 198.).

     If 'skipkeys' is false (the default), a *note TypeError: 198. will
     be raised when trying to encode keys that are not *note str: 169,
     *note int: 19b, *note float: 196, *note bool: 3c3. or ‘None’.  If
     'skipkeys' is true, such items are simply skipped.

     If 'ensure_ascii' is true (the default), the output is guaranteed
     to have all incoming non-ASCII and non-printable characters
     escaped.  If 'ensure_ascii' is false, all characters will be output
     as-is, except for the characters that must be escaped: quotation
     mark, reverse solidus, and the control characters U+0000 through
     U+001F.

     If 'check_circular' is true (the default), then lists, dicts, and
     custom encoded objects will be checked for circular references
     during encoding to prevent an infinite recursion (which would cause
     a *note RecursionError: f6a.).  Otherwise, no such check takes
     place.

     If 'allow_nan' is true (the default), then ‘NaN’, ‘Infinity’, and
     ‘-Infinity’ will be encoded as such.  This behavior is not JSON
     specification compliant, but is consistent with most JavaScript
     based encoders and decoders.  Otherwise, it will be a *note
     ValueError: 2ec. to encode such floats.

     If 'sort_keys' is true (default: ‘False’), then the output of
     dictionaries will be sorted by key; this is useful for regression
     tests to ensure that JSON serializations can be compared on a
     day-to-day basis.

     If 'indent' is a non-negative integer or string, then JSON array
     elements and object members will be pretty-printed with that indent
     level.  An indent level of 0, negative, or ‘""’ will only insert
     newlines.  ‘None’ (the default) selects the most compact
     representation.  Using a positive integer indent indents that many
     spaces per level.  If 'indent' is a string (such as ‘"\t"’), that
     string is used to indent each level.

     Cambiato nella versione 3.2: Allow strings for 'indent' in addition
     to integers.

     If specified, 'separators' should be an ‘(item_separator,
     key_separator)’ tuple.  The default is ‘(', ', ': ')’ if 'indent'
     is ‘None’ and ‘(',', ': ')’ otherwise.  To get the most compact
     JSON representation, you should specify ‘(',', ':')’ to eliminate
     whitespace.

     Cambiato nella versione 3.4: Use ‘(',', ': ')’ as default if
     'indent' is not ‘None’.

     If specified, 'default' should be a function that gets called for
     objects that can’t otherwise be serialized.  It should return a
     JSON encodable version of the object or raise a *note TypeError:
     198.  If not specified, *note TypeError: 198. is raised.

     Cambiato nella versione 3.6: All parameters are now *note
     keyword-only: 5a5.

      -- Metodo: default (o)

          Implement this method in a subclass such that it returns a
          serializable object for 'o', or calls the base implementation
          (to raise a *note TypeError: 198.).

          For example, to support arbitrary iterators, you could
          implement *note default(): 3bc0. like this:

               def default(self, o):
                  try:
                      iterable = iter(o)
                  except TypeError:
                      pass
                  else:
                      return list(iterable)
                  # Let the base class default method raise the TypeError
                  return super().default(o)

      -- Metodo: encode (o)

          Return a JSON string representation of a Python data
          structure, 'o'.  For example:

               >>> json.JSONEncoder().encode({"foo": ["bar", "baz"]})
               '{"foo": ["bar", "baz"]}'

      -- Metodo: iterencode (o)

          Encode the given object, 'o', and yield each string
          representation as available.  For example:

               for chunk in json.JSONEncoder().iterencode(bigobject):
                   mysocket.write(chunk)

   ---------- Footnotes ----------

   (1) https://www.jsonrpc.org


File: python.info,  Node: Exceptions<19>,  Next: Standard Compliance and Interoperability,  Prev: Encoders and Decoders,  Up: json — JSON encoder and decoder

5.20.2.3 Exceptions
...................

 -- Eccezione: json.JSONDecodeError (msg, doc, pos)

     Subclass of *note ValueError: 2ec. with the following additional
     attributes:

      -- Attributo: msg

          The unformatted error message.

      -- Attributo: doc

          The JSON document being parsed.

      -- Attributo: pos

          The start index of 'doc' where parsing failed.

      -- Attributo: lineno

          The line corresponding to 'pos'.

      -- Attributo: colno

          The column corresponding to 'pos'.

     Added in version 3.5.


File: python.info,  Node: Standard Compliance and Interoperability,  Next: Command-line interface<5>,  Prev: Exceptions<19>,  Up: json — JSON encoder and decoder

5.20.2.4 Standard Compliance and Interoperability
.................................................

The JSON format is specified by RFC 7159(1) and by ECMA-404(2).  This
section details this module’s level of compliance with the RFC. For
simplicity, *note JSONEncoder: f44. and *note JSONDecoder: f45.
subclasses, and parameters other than those explicitly mentioned, are
not considered.

This module does not comply with the RFC in a strict fashion,
implementing some extensions that are valid JavaScript but not valid
JSON. In particular:

   - Infinite and NaN number values are accepted and output;

   - Repeated names within an object are accepted, and only the value of
     the last name-value pair is used.

Since the RFC permits RFC-compliant parsers to accept input texts that
are not RFC-compliant, this module’s deserializer is technically
RFC-compliant under default settings.

* Menu:

* Character Encodings::
* Infinite and NaN Number Values::
* Repeated Names Within an Object::
* Top-level Non-Object, Non-Array Values: Top-level Non-Object Non-Array Values.
* Implementation Limitations::

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc7159.html

   (2) 
https://ecma-international.org/publications-and-standards/standards/ecma-404/


File: python.info,  Node: Character Encodings,  Next: Infinite and NaN Number Values,  Up: Standard Compliance and Interoperability

5.20.2.5 Character Encodings
............................

The RFC requires that JSON be represented using either UTF-8, UTF-16, or
UTF-32, with UTF-8 being the recommended default for maximum
interoperability.

As permitted, though not required, by the RFC, this module’s serializer
sets 'ensure_ascii=True' by default, thus escaping the output so that
the resulting strings only contain printable ASCII characters.

Other than the 'ensure_ascii' parameter, this module is defined strictly
in terms of conversion between Python objects and *note Unicode strings:
169, and thus does not otherwise directly address the issue of character
encodings.

The RFC prohibits adding a byte order mark (BOM) to the start of a JSON
text, and this module’s serializer does not add a BOM to its output.
The RFC permits, but does not require, JSON deserializers to ignore an
initial BOM in their input.  This module’s deserializer raises a *note
ValueError: 2ec. when an initial BOM is present.

The RFC does not explicitly forbid JSON strings which contain byte
sequences that don’t correspond to valid Unicode characters (e.g.
unpaired UTF-16 surrogates), but it does note that they may cause
interoperability problems.  By default, this module accepts and outputs
(when present in the original *note str: 169.) code points for such
sequences.


File: python.info,  Node: Infinite and NaN Number Values,  Next: Repeated Names Within an Object,  Prev: Character Encodings,  Up: Standard Compliance and Interoperability

5.20.2.6 Infinite and NaN Number Values
.......................................

The RFC does not permit the representation of infinite or NaN number
values.  Despite that, by default, this module accepts and outputs
‘Infinity’, ‘-Infinity’, and ‘NaN’ as if they were valid JSON number
literal values:

     >>> # Neither of these calls raises an exception, but the results are not valid JSON
     >>> json.dumps(float('-inf'))
     '-Infinity'
     >>> json.dumps(float('nan'))
     'NaN'
     >>> # Same when deserializing
     >>> json.loads('-Infinity')
     -inf
     >>> json.loads('NaN')
     nan

In the serializer, the 'allow_nan' parameter can be used to alter this
behavior.  In the deserializer, the 'parse_constant' parameter can be
used to alter this behavior.


File: python.info,  Node: Repeated Names Within an Object,  Next: Top-level Non-Object Non-Array Values,  Prev: Infinite and NaN Number Values,  Up: Standard Compliance and Interoperability

5.20.2.7 Repeated Names Within an Object
........................................

The RFC specifies that the names within a JSON object should be unique,
but does not mandate how repeated names in JSON objects should be
handled.  By default, this module does not raise an exception; instead,
it ignores all but the last name-value pair for a given name:

     >>> weird_json = '{"x": 1, "x": 2, "x": 3}'
     >>> json.loads(weird_json)
     {'x': 3}

The 'object_pairs_hook' parameter can be used to alter this behavior.


File: python.info,  Node: Top-level Non-Object Non-Array Values,  Next: Implementation Limitations,  Prev: Repeated Names Within an Object,  Up: Standard Compliance and Interoperability

5.20.2.8 Top-level Non-Object, Non-Array Values
...............................................

The old version of JSON specified by the obsolete RFC 4627(1) required
that the top-level value of a JSON text must be either a JSON object or
array (Python *note dict: 183. or *note list: 24d.), and could not be a
JSON null, boolean, number, or string value.  RFC 7159(2) removed that
restriction, and this module does not and has never implemented that
restriction in either its serializer or its deserializer.

Regardless, for maximum interoperability, you may wish to voluntarily
adhere to the restriction yourself.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc4627.html

   (2) https://datatracker.ietf.org/doc/html/rfc7159.html


File: python.info,  Node: Implementation Limitations,  Prev: Top-level Non-Object Non-Array Values,  Up: Standard Compliance and Interoperability

5.20.2.9 Implementation Limitations
...................................

Some JSON deserializer implementations may set limits on:

   * the size of accepted JSON texts

   * the maximum level of nesting of JSON objects and arrays

   * the range and precision of JSON numbers

   * the content and maximum length of JSON strings

This module does not impose any such limits beyond those of the relevant
Python datatypes themselves or the Python interpreter itself.

When serializing to JSON, beware any such limitations in applications
that may consume your JSON. In particular, it is common for JSON numbers
to be deserialized into IEEE 754 double precision numbers and thus
subject to that representation’s range and precision limitations.  This
is especially relevant when serializing Python *note int: 19b. values of
extremely large magnitude, or when serializing instances of «exotic»
numerical types such as *note decimal.Decimal: 1fe.


File: python.info,  Node: Command-line interface<5>,  Prev: Standard Compliance and Interoperability,  Up: json — JSON encoder and decoder

5.20.2.10 Command-line interface
................................

'Source code:' Lib/json/tool.py(1)

__________________________________________________________________

The *note json: 86. module can be invoked as a script via ‘python -m
json’ to validate and pretty-print JSON objects.  The *note json.tool:
87. submodule implements this interface.

If the optional ‘infile’ and ‘outfile’ arguments are not specified,
*note sys.stdin: 760. and *note sys.stdout: ccf. will be used
respectively:

     $ echo '{"json": "obj"}' | python -m json
     {
         "json": "obj"
     }
     $ echo '{1.2:3.4}' | python -m json
     Expecting property name enclosed in double quotes: line 1 column 2 (char 1)

Cambiato nella versione 3.5: The output is now in the same order as the
input.  Use the *note -sort-keys: 3bd4. option to sort the output of
dictionaries alphabetically by key.

Cambiato nella versione 3.14: The *note json: 86. module may now be
directly executed as ‘python -m json’.  For backwards compatibility,
invoking the CLI as ‘python -m json.tool’ remains supported.

* Menu:

* Command-line options: Command-line options<4>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/json/tool.py


File: python.info,  Node: Command-line options<4>,  Up: Command-line interface<5>

5.20.2.11 Command-line options
..............................

 -- Option: infile

     The JSON file to be validated or pretty-printed:

          $ python -m json mp_films.json
          [
              {
                  "title": "And Now for Something Completely Different",
                  "year": 1971
              },
              {
                  "title": "Monty Python and the Holy Grail",
                  "year": 1975
              }
          ]

     If 'infile' is not specified, read from *note sys.stdin: 760.

 -- Option: outfile

     Write the output of the 'infile' to the given 'outfile'.
     Otherwise, write it to *note sys.stdout: ccf.

 -- Option: --sort-keys

     Sort the output of dictionaries alphabetically by key.

     Added in version 3.5.

 -- Option: --no-ensure-ascii

     Disable escaping of non-ascii characters, see *note json.dumps():
     f43. for more information.

     Added in version 3.9.

 -- Option: --json-lines

     Parse every input line as separate JSON object.

     Added in version 3.8.

 -- Option: --indent, --tab, --no-indent, --compact

     Mutually exclusive options for whitespace control.

     Added in version 3.9.

 -- Option: -h, --help

     Show the help message.


File: python.info,  Node: mailbox — Manipulate mailboxes in various formats,  Next: mimetypes — Map filenames to MIME types,  Prev: json — JSON encoder and decoder,  Up: Internet Data Handling

5.20.3 ‘mailbox’ — Manipulate mailboxes in various formats
----------------------------------------------------------

'Source code:' Lib/mailbox.py(1)

__________________________________________________________________

This module defines two classes, *note Mailbox: 1454. and *note Message:
1458, for accessing and manipulating on-disk mailboxes and the messages
they contain.  ‘Mailbox’ offers a dictionary-like mapping from keys to
messages.  ‘Message’ extends the *note email.message: 48. module’s *note
Message: 581. class with format-specific state and behavior.  Supported
mailbox formats are Maildir, mbox, MH, Babyl, and MMDF.

Vedi anche
..........

Module *note email: 3f.

     Represent and manipulate messages.

* Menu:

* Mailbox objects::
* Message objects::
* Exceptions: Exceptions<20>.
* Examples: Examples<24>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/mailbox.py


File: python.info,  Node: Mailbox objects,  Next: Message objects,  Up: mailbox — Manipulate mailboxes in various formats

5.20.3.1 ‘Mailbox’ objects
..........................

 -- Classe: mailbox.Mailbox

     A mailbox, which may be inspected and modified.

     The ‘Mailbox’ class defines an interface and is not intended to be
     instantiated.  Instead, format-specific subclasses should inherit
     from ‘Mailbox’ and your code should instantiate a particular
     subclass.

     The ‘Mailbox’ interface is dictionary-like, with small keys
     corresponding to messages.  Keys are issued by the ‘Mailbox’
     instance with which they will be used and are only meaningful to
     that ‘Mailbox’ instance.  A key continues to identify a message
     even if the corresponding message is modified, such as by replacing
     it with another message.

     Messages may be added to a ‘Mailbox’ instance using the set-like
     method *note add(): 1453. and removed using a ‘del’ statement or
     the set-like methods *note remove(): 3be5. and *note discard():
     3be6.

     ‘Mailbox’ interface semantics differ from dictionary semantics in
     some noteworthy ways.  Each time a message is requested, a new
     representation (typically a *note Message: 1458. instance) is
     generated based upon the current state of the mailbox.  Similarly,
     when a message is added to a ‘Mailbox’ instance, the provided
     message representation’s contents are copied.  In neither case is a
     reference to the message representation kept by the ‘Mailbox’
     instance.

     The default ‘Mailbox’ *note iterator: 4c9. iterates over message
     representations, not keys as the default *note dictionary: 183.
     iterator does.  Moreover, modification of a mailbox during
     iteration is safe and well-defined.  Messages added to the mailbox
     after an iterator is created will not be seen by the iterator.
     Messages removed from the mailbox before the iterator yields them
     will be silently skipped, though using a key from an iterator may
     result in a *note KeyError: 5e7. exception if the corresponding
     message is subsequently removed.

          Avvertimento: Be very cautious when modifying mailboxes that
          might be simultaneously changed by some other process.  The
          safest mailbox format to use for such tasks is *note Maildir:
          65e.; try to avoid using single-file formats such as *note
          mbox: 19e3. for concurrent writing.  If you’re modifying a
          mailbox, you 'must' lock it by calling the *note lock(): 3be7.
          and *note unlock(): 3be8. methods 'before' reading any
          messages in the file or making any changes by adding or
          deleting a message.  Failing to lock the mailbox runs the risk
          of losing messages or corrupting the entire mailbox.

     ‘Mailbox’ instances have the following methods:

      -- Metodo: add (message)

          Add 'message' to the mailbox and return the key that has been
          assigned to it.

          Parameter 'message' may be a *note Message: 1458. instance, an
          *note email.message.Message: 581. instance, a string, a byte
          string, or a file-like object (which should be open in binary
          mode).  If 'message' is an instance of the appropriate
          format-specific *note Message: 1458. subclass (e.g., if it’s
          an *note mboxMessage: 3aa5. instance and this is an *note
          mbox: 19e3. instance), its format-specific information is
          used.  Otherwise, reasonable defaults for format-specific
          information are used.

          Cambiato nella versione 3.2: Support for binary input was
          added.

      -- Metodo: remove (key)
      -- Metodo: __delitem__ (key)
      -- Metodo: discard (key)

          Delete the message corresponding to 'key' from the mailbox.

          If no such message exists, a *note KeyError: 5e7. exception is
          raised if the method was called as *note remove(): 3be5. or
          *note __delitem__(): 3be9. but no exception is raised if the
          method was called as *note discard(): 3be6.  The behavior of
          *note discard(): 3be6. may be preferred if the underlying
          mailbox format supports concurrent modification by other
          processes.

      -- Metodo: __setitem__ (key, message)

          Replace the message corresponding to 'key' with 'message'.
          Raise a *note KeyError: 5e7. exception if no message already
          corresponds to 'key'.

          As with *note add(): 1453, parameter 'message' may be a *note
          Message: 1458. instance, an *note email.message.Message: 581.
          instance, a string, a byte string, or a file-like object
          (which should be open in binary mode).  If 'message' is an
          instance of the appropriate format-specific *note Message:
          1458. subclass (e.g., if it’s an *note mboxMessage: 3aa5.
          instance and this is an *note mbox: 19e3. instance), its
          format-specific information is used.  Otherwise, the
          format-specific information of the message that currently
          corresponds to 'key' is left unchanged.

      -- Metodo: iterkeys ()

          Return an *note iterator: 4c9. over all keys

      -- Metodo: keys ()

          The same as *note iterkeys(): 3beb, except that a *note list:
          24d. is returned rather than an *note iterator: 4c9.

      -- Metodo: itervalues ()
      -- Metodo: __iter__ ()

          Return an *note iterator: 4c9. over representations of all
          messages.  The messages are represented as instances of the
          appropriate format-specific *note Message: 1458. subclass
          unless a custom message factory was specified when the
          ‘Mailbox’ instance was initialized.

               Nota: The behavior of *note __iter__(): 3bee. is unlike
               that of dictionaries, which iterate over keys.

      -- Metodo: values ()

          The same as *note itervalues(): 3bed, except that a *note
          list: 24d. is returned rather than an *note iterator: 4c9.

      -- Metodo: iteritems ()

          Return an *note iterator: 4c9. over ('key', 'message') pairs,
          where 'key' is a key and 'message' is a message
          representation.  The messages are represented as instances of
          the appropriate format-specific *note Message: 1458. subclass
          unless a custom message factory was specified when the
          ‘Mailbox’ instance was initialized.

      -- Metodo: items ()

          The same as *note iteritems(): 3bf0, except that a *note list:
          24d. of pairs is returned rather than an *note iterator: 4c9.
          of pairs.

      -- Metodo: get (key, default=None)
      -- Metodo: __getitem__ (key)

          Return a representation of the message corresponding to 'key'.
          If no such message exists, 'default' is returned if the method
          was called as *note get(): 3bf2. and a *note KeyError: 5e7.
          exception is raised if the method was called as
          ‘__getitem__()’.  The message is represented as an instance of
          the appropriate format-specific *note Message: 1458. subclass
          unless a custom message factory was specified when the
          ‘Mailbox’ instance was initialized.

      -- Metodo: get_message (key)

          Return a representation of the message corresponding to 'key'
          as an instance of the appropriate format-specific *note
          Message: 1458. subclass, or raise a *note KeyError: 5e7.
          exception if no such message exists.

      -- Metodo: get_bytes (key)

          Return a byte representation of the message corresponding to
          'key', or raise a *note KeyError: 5e7. exception if no such
          message exists.

          Added in version 3.2.

      -- Metodo: get_string (key)

          Return a string representation of the message corresponding to
          'key', or raise a *note KeyError: 5e7. exception if no such
          message exists.  The message is processed through *note
          email.message.Message: 581. to convert it to a 7bit clean
          representation.

      -- Metodo: get_file (key)

          Return a *note file-like: 1794. representation of the message
          corresponding to 'key', or raise a *note KeyError: 5e7.
          exception if no such message exists.  The file-like object
          behaves as if open in binary mode.  This file should be closed
          once it is no longer needed.

          Cambiato nella versione 3.2: The file object really is a *note
          binary file: 2058.; previously it was incorrectly returned in
          text mode.  Also, the *note file-like object: 1794. now
          supports the *note context manager: 1e1. protocol: you can use
          a *note with: 186. statement to automatically close it.

               Nota: Unlike other representations of messages, *note
               file-like: 1794. representations are not necessarily
               independent of the ‘Mailbox’ instance that created them
               or of the underlying mailbox.  More specific
               documentation is provided by each subclass.

      -- Metodo: __contains__ (key)

          Return ‘True’ if 'key' corresponds to a message, ‘False’
          otherwise.

      -- Metodo: __len__ ()

          Return a count of messages in the mailbox.

      -- Metodo: clear ()

          Delete all messages from the mailbox.

      -- Metodo: pop (key, default=None)

          Return a representation of the message corresponding to 'key'
          and delete the message.  If no such message exists, return
          'default'.  The message is represented as an instance of the
          appropriate format-specific *note Message: 1458. subclass
          unless a custom message factory was specified when the
          ‘Mailbox’ instance was initialized.

      -- Metodo: popitem ()

          Return an arbitrary ('key', 'message') pair, where 'key' is a
          key and 'message' is a message representation, and delete the
          corresponding message.  If the mailbox is empty, raise a *note
          KeyError: 5e7. exception.  The message is represented as an
          instance of the appropriate format-specific *note Message:
          1458. subclass unless a custom message factory was specified
          when the ‘Mailbox’ instance was initialized.

      -- Metodo: update (arg)

          Parameter 'arg' should be a 'key'-to-'message' mapping or an
          iterable of ('key', 'message') pairs.  Updates the mailbox so
          that, for each given 'key' and 'message', the message
          corresponding to 'key' is set to 'message' as if by using
          *note __setitem__(): 3bea.  As with *note __setitem__(): 3bea,
          each 'key' must already correspond to a message in the mailbox
          or else a *note KeyError: 5e7. exception will be raised, so in
          general it is incorrect for 'arg' to be a ‘Mailbox’ instance.

               Nota: Unlike with dictionaries, keyword arguments are not
               supported.

      -- Metodo: flush ()

          Write any pending changes to the filesystem.  For some *note
          Mailbox: 1454. subclasses, changes are always written
          immediately and ‘flush()’ does nothing, but you should still
          make a habit of calling this method.

      -- Metodo: lock ()

          Acquire an exclusive advisory lock on the mailbox so that
          other processes know not to modify it.  An *note
          ExternalClashError: 3bfb. is raised if the lock is not
          available.  The particular locking mechanisms used depend upon
          the mailbox format.  You should 'always' lock the mailbox
          before making any modifications to its contents.

      -- Metodo: unlock ()

          Release the lock on the mailbox, if any.

      -- Metodo: close ()

          Flush the mailbox, unlock it if necessary, and close any open
          files.  For some ‘Mailbox’ subclasses, this method does
          nothing.

* Menu:

* Maildir objects::
* mbox objects::
* MH objects::
* Babyl objects::
* MMDF objects::


File: python.info,  Node: Maildir objects,  Next: mbox objects,  Up: Mailbox objects

5.20.3.2 ‘Maildir’ objects
..........................

 -- Classe: mailbox.Maildir (dirname, factory=None, create=True)

     A subclass of *note Mailbox: 1454. for mailboxes in Maildir format.
     Parameter 'factory' is a callable object that accepts a file-like
     message representation (which behaves as if opened in binary mode)
     and returns a custom representation.  If 'factory' is ‘None’, *note
     MaildirMessage: 3bff. is used as the default message
     representation.  If 'create' is ‘True’, the mailbox is created if
     it does not exist.

     If 'create' is ‘True’ and the 'dirname' path exists, it will be
     treated as an existing maildir without attempting to verify its
     directory layout.

     It is for historical reasons that 'dirname' is named as such rather
     than 'path'.

     Maildir is a directory-based mailbox format invented for the qmail
     mail transfer agent and now widely supported by other programs.
     Messages in a Maildir mailbox are stored in separate files within a
     common directory structure.  This design allows Maildir mailboxes
     to be accessed and modified by multiple unrelated programs without
     data corruption, so file locking is unnecessary.

     Maildir mailboxes contain three subdirectories, namely: ‘tmp’,
     ‘new’, and ‘cur’.  Messages are created momentarily in the ‘tmp’
     subdirectory and then moved to the ‘new’ subdirectory to finalize
     delivery.  A mail user agent may subsequently move the message to
     the ‘cur’ subdirectory and store information about the state of the
     message in a special «info» section appended to its file name.

     Folders of the style introduced by the Courier mail transfer agent
     are also supported.  Any subdirectory of the main mailbox is
     considered a folder if ‘'.'’ is the first character in its name.
     Folder names are represented by ‘Maildir’ without the leading
     ‘'.'’.  Each folder is itself a Maildir mailbox but should not
     contain other folders.  Instead, a logical nesting is indicated
     using ‘'.'’ to delimit levels, e.g., «Archived.2005.07».

      -- Attributo: colon

          The Maildir specification requires the use of a colon (‘':'’)
          in certain message file names.  However, some operating
          systems do not permit this character in file names, If you
          wish to use a Maildir-like format on such an operating system,
          you should specify another character to use instead.  The
          exclamation point (‘'!'’) is a popular choice.  For example:

               import mailbox
               mailbox.Maildir.colon = '!'

          The ‘colon’ attribute may also be set on a per-instance basis.

     Cambiato nella versione 3.13: *note Maildir: 65e. now ignores files
     with a leading dot.

     ‘Maildir’ instances have all of the methods of *note Mailbox: 1454.
     in addition to the following:

      -- Metodo: list_folders ()

          Return a list of the names of all folders.

      -- Metodo: get_folder (folder)

          Return a ‘Maildir’ instance representing the folder whose name
          is 'folder'.  A *note NoSuchMailboxError: 3c03. exception is
          raised if the folder does not exist.

      -- Metodo: add_folder (folder)

          Create a folder whose name is 'folder' and return a ‘Maildir’
          instance representing it.

      -- Metodo: remove_folder (folder)

          Delete the folder whose name is 'folder'.  If the folder
          contains any messages, a *note NotEmptyError: 3c06. exception
          will be raised and the folder will not be deleted.

      -- Metodo: clean ()

          Delete temporary files from the mailbox that have not been
          accessed in the last 36 hours.  The Maildir specification says
          that mail-reading programs should do this occasionally.

      -- Metodo: get_flags (key)

          Return as a string the flags that are set on the message
          corresponding to 'key'.  This is the same as
          ‘get_message(key).get_flags()’ but much faster, because it
          does not open the message file.  Use this method when
          iterating over the keys to determine which messages are
          interesting to get.

          If you do have a *note MaildirMessage: 3bff. object, use its
          *note get_flags(): 3c08. method instead, because changes made
          by the message’s *note set_flags(): 3c09, *note add_flag():
          3c0a. and *note remove_flag(): 3c0b. methods are not reflected
          here until the mailbox’s *note __setitem__(): 3c0c. method is
          called.

          Added in version 3.13.

      -- Metodo: set_flags (key, flags)

          On the message corresponding to 'key', set the flags specified
          by 'flags' and unset all others.  Calling
          ‘some_mailbox.set_flags(key, flags)’ is similar to

               one_message = some_mailbox.get_message(key)
               one_message.set_flags(flags)
               some_mailbox[key] = one_message

          but faster, because it does not open the message file.

          If you do have a *note MaildirMessage: 3bff. object, use its
          *note set_flags(): 3c09. method instead, because changes made
          with this mailbox method will not be visible to the message
          object’s method, *note get_flags(): 3c08.

          Added in version 3.13.

      -- Metodo: add_flag (key, flag)

          On the message corresponding to 'key', set the flags specified
          by 'flag' without changing other flags.  To add more than one
          flag at a time, 'flag' may be a string of more than one
          character.

          Considerations for using this method versus the message
          object’s *note add_flag(): 3c0a. method are similar to those
          for *note set_flags(): 1a2f.; see the discussion there.

          Added in version 3.13.

      -- Metodo: remove_flag (key, flag)

          On the message corresponding to 'key', unset the flags
          specified by 'flag' without changing other flags.  To remove
          more than one flag at a time, 'flag' may be a string of more
          than one character.

          Considerations for using this method versus the message
          object’s *note remove_flag(): 3c0b. method are similar to
          those for *note set_flags(): 1a2f.; see the discussion there.

          Added in version 3.13.

      -- Metodo: get_info (key)

          Return a string containing the info for the message
          corresponding to 'key'.  This is the same as
          ‘get_message(key).get_info()’ but much faster, because it does
          not open the message file.  Use this method when iterating
          over the keys to determine which messages are interesting to
          get.

          If you do have a *note MaildirMessage: 3bff. object, use its
          *note get_info(): 3c0d. method instead, because changes made
          by the message’s *note set_info(): 3c0e. method are not
          reflected here until the mailbox’s *note __setitem__(): 3c0c.
          method is called.

          Added in version 3.13.

      -- Metodo: set_info (key, info)

          Set the info of the message corresponding to 'key' to 'info'.
          Calling ‘some_mailbox.set_info(key, flags)’ is similar to

               one_message = some_mailbox.get_message(key)
               one_message.set_info(info)
               some_mailbox[key] = one_message

          but faster, because it does not open the message file.

          If you do have a *note MaildirMessage: 3bff. object, use its
          *note set_info(): 3c0e. method instead, because changes made
          with this mailbox method will not be visible to the message
          object’s method, *note get_info(): 3c0d.

          Added in version 3.13.

     Some *note Mailbox: 1454. methods implemented by ‘Maildir’ deserve
     special remarks:

      -- Metodo: add (message)
      -- Metodo: __setitem__ (key, message)
      -- Metodo: update (arg)

               Avvertimento: These methods generate unique file names
               based upon the current process ID. When using multiple
               threads, undetected name clashes may occur and cause
               corruption of the mailbox unless threads are coordinated
               to avoid using these methods to manipulate the same
               mailbox simultaneously.

      -- Metodo: flush ()

          All changes to Maildir mailboxes are immediately applied, so
          this method does nothing.

      -- Metodo: lock ()
      -- Metodo: unlock ()

          Maildir mailboxes do not support (or require) locking, so
          these methods do nothing.

      -- Metodo: close ()

          ‘Maildir’ instances do not keep any open files and the
          underlying mailboxes do not support locking, so this method
          does nothing.

      -- Metodo: get_file (key)

          Depending upon the host platform, it may not be possible to
          modify or remove the underlying message while the returned
          file remains open.

Vedi anche
..........

maildir man page from Courier(1)

     A specification of the format.  Describes a common extension for
     supporting folders.

Using maildir format(2)

     Notes on Maildir by its inventor.  Includes an updated
     name-creation scheme and details on «info» semantics.

   ---------- Footnotes ----------

   (1) https://www.courier-mta.org/maildir.html

   (2) https://cr.yp.to/proto/maildir.html


File: python.info,  Node: mbox objects,  Next: MH objects,  Prev: Maildir objects,  Up: Mailbox objects

5.20.3.3 ‘mbox’ objects
.......................

 -- Classe: mailbox.mbox (path, factory=None, create=True)

     A subclass of *note Mailbox: 1454. for mailboxes in mbox format.
     Parameter 'factory' is a callable object that accepts a file-like
     message representation (which behaves as if opened in binary mode)
     and returns a custom representation.  If 'factory' is ‘None’, *note
     mboxMessage: 3aa5. is used as the default message representation.
     If 'create' is ‘True’, the mailbox is created if it does not exist.

     The mbox format is the classic format for storing mail on Unix
     systems.  All messages in an mbox mailbox are stored in a single
     file with the beginning of each message indicated by a line whose
     first five characters are «From «.

     Several variations of the mbox format exist to address perceived
     shortcomings in the original.  In the interest of compatibility,
     ‘mbox’ implements the original format, which is sometimes referred
     to as 'mboxo'.  This means that the ‘Content-Length’ header, if
     present, is ignored and that any occurrences of «From « at the
     beginning of a line in a message body are transformed to «>From «
     when storing the message, although occurrences of «>From « are not
     transformed to «From « when reading the message.

     Some *note Mailbox: 1454. methods implemented by ‘mbox’ deserve
     special remarks:

      -- Metodo: get_bytes (key, from_=False)

          Note: This method has an extra parameter ('from_') compared
          with other classes.  The first line of an mbox file entry is
          the Unix «From « line.  If 'from_' is False, the first line of
          the file is dropped.

      -- Metodo: get_file (key, from_=False)

          Using the file after calling *note flush(): 19a9. or *note
          close(): 3bfc. on the ‘mbox’ instance may yield unpredictable
          results or raise an exception.

          Note: This method has an extra parameter ('from_') compared
          with other classes.  The first line of an mbox file entry is
          the Unix «From « line.  If 'from_' is False, the first line of
          the file is dropped.

      -- Metodo: get_string (key, from_=False)

          Note: This method has an extra parameter ('from_') compared
          with other classes.  The first line of an mbox file entry is
          the Unix «From « line.  If 'from_' is False, the first line of
          the file is dropped.

      -- Metodo: lock ()
      -- Metodo: unlock ()

          Three locking mechanisms are used—dot locking and, if
          available, the ‘flock()’ and ‘lockf()’ system calls.

Vedi anche
..........

mbox man page from tin(1)

     A specification of the format, with details on locking.

Configuring Netscape Mail on Unix: Why The Content-Length Format is Bad(2)

     An argument for using the original mbox format rather than a
     variation.

"mbox" is a family of several mutually incompatible mailbox formats(3)

     A history of mbox variations.

   ---------- Footnotes ----------

   (1) http://www.tin.org/bin/man.cgi?section=5&topic=mbox

   (2) https://www.jwz.org/doc/content-length.html

   (3) 
https://www.loc.gov/preservation/digital/formats/fdd/fdd000383.shtml


File: python.info,  Node: MH objects,  Next: Babyl objects,  Prev: mbox objects,  Up: Mailbox objects

5.20.3.4 ‘MH’ objects
.....................

 -- Classe: mailbox.MH (path, factory=None, create=True)

     A subclass of *note Mailbox: 1454. for mailboxes in MH format.
     Parameter 'factory' is a callable object that accepts a file-like
     message representation (which behaves as if opened in binary mode)
     and returns a custom representation.  If 'factory' is ‘None’, *note
     MHMessage: 3c1f. is used as the default message representation.  If
     'create' is ‘True’, the mailbox is created if it does not exist.

     MH is a directory-based mailbox format invented for the MH Message
     Handling System, a mail user agent.  Each message in an MH mailbox
     resides in its own file.  An MH mailbox may contain other MH
     mailboxes (called 'folders') in addition to messages.  Folders may
     be nested indefinitely.  MH mailboxes also support 'sequences',
     which are named lists used to logically group messages without
     moving them to sub-folders.  Sequences are defined in a file called
     ‘.mh_sequences’ in each folder.

     The ‘MH’ class manipulates MH mailboxes, but it does not attempt to
     emulate all of ‘mh’’s behaviors.  In particular, it does not modify
     and is not affected by the ‘context’ or ‘.mh_profile’ files that
     are used by ‘mh’ to store its state and configuration.

     ‘MH’ instances have all of the methods of *note Mailbox: 1454. in
     addition to the following:

     Cambiato nella versione 3.13: Supported folders that don’t contain
     a ‘.mh_sequences’ file.

      -- Metodo: list_folders ()

          Return a list of the names of all folders.

      -- Metodo: get_folder (folder)

          Return an ‘MH’ instance representing the folder whose name is
          'folder'.  A *note NoSuchMailboxError: 3c03. exception is
          raised if the folder does not exist.

      -- Metodo: add_folder (folder)

          Create a folder whose name is 'folder' and return an ‘MH’
          instance representing it.

      -- Metodo: remove_folder (folder)

          Delete the folder whose name is 'folder'.  If the folder
          contains any messages, a *note NotEmptyError: 3c06. exception
          will be raised and the folder will not be deleted.

      -- Metodo: get_sequences ()

          Return a dictionary of sequence names mapped to key lists.  If
          there are no sequences, the empty dictionary is returned.

      -- Metodo: set_sequences (sequences)

          Re-define the sequences that exist in the mailbox based upon
          'sequences', a dictionary of names mapped to key lists, like
          returned by *note get_sequences(): 3c24.

      -- Metodo: pack ()

          Rename messages in the mailbox as necessary to eliminate gaps
          in numbering.  Entries in the sequences list are updated
          correspondingly.

               Nota: Already-issued keys are invalidated by this
               operation and should not be subsequently used.

     Some *note Mailbox: 1454. methods implemented by ‘MH’ deserve
     special remarks:

      -- Metodo: remove (key)
      -- Metodo: __delitem__ (key)
      -- Metodo: discard (key)

          These methods immediately delete the message.  The MH
          convention of marking a message for deletion by prepending a
          comma to its name is not used.

      -- Metodo: lock ()
      -- Metodo: unlock ()

          Three locking mechanisms are used—dot locking and, if
          available, the ‘flock()’ and ‘lockf()’ system calls.  For MH
          mailboxes, locking the mailbox means locking the
          ‘.mh_sequences’ file and, only for the duration of any
          operations that affect them, locking individual message files.

      -- Metodo: get_file (key)

          Depending upon the host platform, it may not be possible to
          remove the underlying message while the returned file remains
          open.

      -- Metodo: flush ()

          All changes to MH mailboxes are immediately applied, so this
          method does nothing.

      -- Metodo: close ()

          ‘MH’ instances do not keep any open files, so this method is
          equivalent to *note unlock(): 3c2b.

Vedi anche
..........

nmh - Message Handling System(1)

     Home page of ‘nmh’, an updated version of the original ‘mh’.

MH & nmh: Email for Users & Programmers(2)

     A GPL-licensed book on ‘mh’ and ‘nmh’, with some information on the
     mailbox format.

   ---------- Footnotes ----------

   (1) https://www.nongnu.org/nmh/

   (2) https://rand-mh.sourceforge.io/book/


File: python.info,  Node: Babyl objects,  Next: MMDF objects,  Prev: MH objects,  Up: Mailbox objects

5.20.3.5 ‘Babyl’ objects
........................

 -- Classe: mailbox.Babyl (path, factory=None, create=True)

     A subclass of *note Mailbox: 1454. for mailboxes in Babyl format.
     Parameter 'factory' is a callable object that accepts a file-like
     message representation (which behaves as if opened in binary mode)
     and returns a custom representation.  If 'factory' is ‘None’, *note
     BabylMessage: 3c32. is used as the default message representation.
     If 'create' is ‘True’, the mailbox is created if it does not exist.

     Babyl is a single-file mailbox format used by the Rmail mail user
     agent included with Emacs.  The beginning of a message is indicated
     by a line containing the two characters Control-Underscore
     (‘'\037'’) and Control-L (‘'\014'’).  The end of a message is
     indicated by the start of the next message or, in the case of the
     last message, a line containing a Control-Underscore (‘'\037'’)
     character.

     Messages in a Babyl mailbox have two sets of headers, original
     headers and so-called visible headers.  Visible headers are
     typically a subset of the original headers that have been
     reformatted or abridged to be more attractive.  Each message in a
     Babyl mailbox also has an accompanying list of 'labels', or short
     strings that record extra information about the message, and a list
     of all user-defined labels found in the mailbox is kept in the
     Babyl options section.

     ‘Babyl’ instances have all of the methods of *note Mailbox: 1454.
     in addition to the following:

      -- Metodo: get_labels ()

          Return a list of the names of all user-defined labels used in
          the mailbox.

               Nota: The actual messages are inspected to determine
               which labels exist in the mailbox rather than consulting
               the list of labels in the Babyl options section, but the
               Babyl section is updated whenever the mailbox is
               modified.

     Some *note Mailbox: 1454. methods implemented by ‘Babyl’ deserve
     special remarks:

      -- Metodo: get_file (key)

          In Babyl mailboxes, the headers of a message are not stored
          contiguously with the body of the message.  To generate a
          file-like representation, the headers and body are copied
          together into an *note io.BytesIO: 10a6. instance, which has
          an API identical to that of a file.  As a result, the
          file-like object is truly independent of the underlying
          mailbox but does not save memory compared to a string
          representation.

      -- Metodo: lock ()
      -- Metodo: unlock ()

          Three locking mechanisms are used—dot locking and, if
          available, the ‘flock()’ and ‘lockf()’ system calls.

Vedi anche
..........

Format of Version 5 Babyl Files(1)

     A specification of the Babyl format.

Reading Mail with Rmail(2)

     The Rmail manual, with some information on Babyl semantics.

   ---------- Footnotes ----------

   (1) https://quimby.gnus.org/notes/BABYL

   (2) 
https://www.gnu.org/software/emacs/manual/html_node/emacs/Rmail.html


File: python.info,  Node: MMDF objects,  Prev: Babyl objects,  Up: Mailbox objects

5.20.3.6 ‘MMDF’ objects
.......................

 -- Classe: mailbox.MMDF (path, factory=None, create=True)

     A subclass of *note Mailbox: 1454. for mailboxes in MMDF format.
     Parameter 'factory' is a callable object that accepts a file-like
     message representation (which behaves as if opened in binary mode)
     and returns a custom representation.  If 'factory' is ‘None’, *note
     MMDFMessage: 3c39. is used as the default message representation.
     If 'create' is ‘True’, the mailbox is created if it does not exist.

     MMDF is a single-file mailbox format invented for the Multichannel
     Memorandum Distribution Facility, a mail transfer agent.  Each
     message is in the same form as an mbox message but is bracketed
     before and after by lines containing four Control-A (‘'\001'’)
     characters.  As with the mbox format, the beginning of each message
     is indicated by a line whose first five characters are «From «, but
     additional occurrences of «From « are not transformed to «>From «
     when storing messages because the extra message separator lines
     prevent mistaking such occurrences for the starts of subsequent
     messages.

     Some *note Mailbox: 1454. methods implemented by ‘MMDF’ deserve
     special remarks:

      -- Metodo: get_bytes (key, from_=False)

          Note: This method has an extra parameter ('from_') compared
          with other classes.  The first line of an mbox file entry is
          the Unix «From « line.  If 'from_' is False, the first line of
          the file is dropped.

      -- Metodo: get_file (key, from_=False)

          Using the file after calling *note flush(): 19a9. or *note
          close(): 3bfc. on the ‘MMDF’ instance may yield unpredictable
          results or raise an exception.

          Note: This method has an extra parameter ('from_') compared
          with other classes.  The first line of an mbox file entry is
          the Unix «From « line.  If 'from_' is False, the first line of
          the file is dropped.

      -- Metodo: lock ()
      -- Metodo: unlock ()

          Three locking mechanisms are used—dot locking and, if
          available, the ‘flock()’ and ‘lockf()’ system calls.

Vedi anche
..........

mmdf man page from tin(1)

     A specification of MMDF format from the documentation of tin, a
     newsreader.

MMDF(2)

     A Wikipedia article describing the Multichannel Memorandum
     Distribution Facility.

   ---------- Footnotes ----------

   (1) http://www.tin.org/bin/man.cgi?section=5&topic=mmdf

   (2) https://en.wikipedia.org/wiki/MMDF


File: python.info,  Node: Message objects,  Next: Exceptions<20>,  Prev: Mailbox objects,  Up: mailbox — Manipulate mailboxes in various formats

5.20.3.7 ‘Message’ objects
..........................

 -- Classe: mailbox.Message (message=None)

     A subclass of the *note email.message: 48. module’s *note Message:
     581.  Subclasses of ‘mailbox.Message’ add mailbox-format-specific
     state and behavior.

     If 'message' is omitted, the new instance is created in a default,
     empty state.  If 'message' is an *note email.message.Message: 581.
     instance, its contents are copied; furthermore, any format-specific
     information is converted insofar as possible if 'message' is a
     ‘Message’ instance.  If 'message' is a string, a byte string, or a
     file, it should contain an RFC 5322(1)-compliant message, which is
     read and parsed.  Files should be open in binary mode, but text
     mode files are accepted for backward compatibility.

     The format-specific state and behaviors offered by subclasses vary,
     but in general it is only the properties that are not specific to a
     particular mailbox that are supported (although presumably the
     properties are specific to a particular mailbox format).  For
     example, file offsets for single-file mailbox formats and file
     names for directory-based mailbox formats are not retained, because
     they are only applicable to the original mailbox.  But state such
     as whether a message has been read by the user or marked as
     important is retained, because it applies to the message itself.

     There is no requirement that ‘Message’ instances be used to
     represent messages retrieved using *note Mailbox: 1454. instances.
     In some situations, the time and memory required to generate
     ‘Message’ representations might not be acceptable.  For such
     situations, ‘Mailbox’ instances also offer string and file-like
     representations, and a custom message factory may be specified when
     a ‘Mailbox’ instance is initialized.

* Menu:

* MaildirMessage objects::
* mboxMessage objects::
* MHMessage objects::
* BabylMessage objects::
* MMDFMessage objects::

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc5322.html


File: python.info,  Node: MaildirMessage objects,  Next: mboxMessage objects,  Up: Message objects

5.20.3.8 ‘MaildirMessage’ objects
.................................

 -- Classe: mailbox.MaildirMessage (message=None)

     A message with Maildir-specific behaviors.  Parameter 'message' has
     the same meaning as with the *note Message: 1458. constructor.

     Typically, a mail user agent application moves all of the messages
     in the ‘new’ subdirectory to the ‘cur’ subdirectory after the first
     time the user opens and closes the mailbox, recording that the
     messages are old whether or not they’ve actually been read.  Each
     message in ‘cur’ has an «info» section added to its file name to
     store information about its state.  (Some mail readers may also add
     an «info» section to messages in ‘new’.)  The «info» section may
     take one of two forms: it may contain «2,» followed by a list of
     standardized flags (e.g., «2,FR») or it may contain «1,» followed
     by so-called experimental information.  Standard flags for Maildir
     messages are as follows:

     Flag       Meaning       Explanation
                              
     --------------------------------------------------------------
                              
     D          Draft         Under composition
                              
                              
     F          Flagged       Marked as important
                              
                              
     P          Passed        Forwarded, resent, or bounced
                              
                              
     R          Replied       Replied to
                              
                              
     S          Seen          Read
                              
                              
     T          Trashed       Marked for subsequent deletion
                              

     ‘MaildirMessage’ instances offer the following methods:

      -- Metodo: get_subdir ()

          Return either «new» (if the message should be stored in the
          ‘new’ subdirectory) or «cur» (if the message should be stored
          in the ‘cur’ subdirectory).

               Nota: A message is typically moved from ‘new’ to ‘cur’
               after its mailbox has been accessed, whether or not the
               message has been read.  A message ‘msg’ has been read if
               ‘"S" in msg.get_flags()’ is ‘True’.

      -- Metodo: set_subdir (subdir)

          Set the subdirectory the message should be stored in.
          Parameter 'subdir' must be either «new» or «cur».

      -- Metodo: get_flags ()

          Return a string specifying the flags that are currently set.
          If the message complies with the standard Maildir format, the
          result is the concatenation in alphabetical order of zero or
          one occurrence of each of ‘'D'’, ‘'F'’, ‘'P'’, ‘'R'’, ‘'S'’,
          and ‘'T'’.  The empty string is returned if no flags are set
          or if «info» contains experimental semantics.

      -- Metodo: set_flags (flags)

          Set the flags specified by 'flags' and unset all others.

      -- Metodo: add_flag (flag)

          Set the flag(s) specified by 'flag' without changing other
          flags.  To add more than one flag at a time, 'flag' may be a
          string of more than one character.  The current «info» is
          overwritten whether or not it contains experimental
          information rather than flags.

      -- Metodo: remove_flag (flag)

          Unset the flag(s) specified by 'flag' without changing other
          flags.  To remove more than one flag at a time, 'flag' maybe a
          string of more than one character.  If «info» contains
          experimental information rather than flags, the current «info»
          is not modified.

      -- Metodo: get_date ()

          Return the delivery date of the message as a floating-point
          number representing seconds since the epoch.

      -- Metodo: set_date (date)

          Set the delivery date of the message to 'date', a
          floating-point number representing seconds since the epoch.

      -- Metodo: get_info ()

          Return a string containing the «info» for a message.  This is
          useful for accessing and modifying «info» that is experimental
          (i.e., not a list of flags).

      -- Metodo: set_info (info)

          Set «info» to 'info', which should be a string.

When a ‘MaildirMessage’ instance is created based upon an *note
mboxMessage: 3aa5. or *note MMDFMessage: 3c39. instance, the ‘Status’
and ‘X-Status’ headers are omitted and the following conversions take
place:

Resulting state          *note mboxMessage: 3aa5. or
                         *note MMDFMessage: 3c39. state
                         
----------------------------------------------------------------------------
                         
«cur» subdirectory       O flag
                         
                         
F flag                   F flag
                         
                         
R flag                   A flag
                         
                         
S flag                   R flag
                         
                         
T flag                   D flag
                         

When a ‘MaildirMessage’ instance is created based upon an *note
MHMessage: 3c1f. instance, the following conversions take place:

Resulting state                     *note MHMessage: 3c1f. state
                                    
-------------------------------------------------------------------
                                    
«cur» subdirectory                  «unseen» sequence
                                    
                                    
«cur» subdirectory and S flag       no «unseen» sequence
                                    
                                    
F flag                              «flagged» sequence
                                    
                                    
R flag                              «replied» sequence
                                    

When a ‘MaildirMessage’ instance is created based upon a *note
BabylMessage: 3c32. instance, the following conversions take place:

Resulting state                     *note BabylMessage: 3c32. state
                                    
------------------------------------------------------------------------
                                    
«cur» subdirectory                  «unseen» label
                                    
                                    
«cur» subdirectory and S flag       no «unseen» label
                                    
                                    
P flag                              «forwarded» or «resent» label
                                    
                                    
R flag                              «answered» label
                                    
                                    
T flag                              «deleted» label
                                    


File: python.info,  Node: mboxMessage objects,  Next: MHMessage objects,  Prev: MaildirMessage objects,  Up: Message objects

5.20.3.9 ‘mboxMessage’ objects
..............................

 -- Classe: mailbox.mboxMessage (message=None)

     A message with mbox-specific behaviors.  Parameter 'message' has
     the same meaning as with the *note Message: 1458. constructor.

     Messages in an mbox mailbox are stored together in a single file.
     The sender’s envelope address and the time of delivery are
     typically stored in a line beginning with «From « that is used to
     indicate the start of a message, though there is considerable
     variation in the exact format of this data among mbox
     implementations.  Flags that indicate the state of the message,
     such as whether it has been read or marked as important, are
     typically stored in ‘Status’ and ‘X-Status’ headers.

     Conventional flags for mbox messages are as follows:

     Flag       Meaning        Explanation
                               
     ---------------------------------------------------------------
                               
     R          Read           Read
                               
                               
     O          Old            Previously detected by MUA
                               
                               
     D          Deleted        Marked for subsequent deletion
                               
                               
     F          Flagged        Marked as important
                               
                               
     A          Answered       Replied to
                               

     The «R» and «O» flags are stored in the ‘Status’ header, and the
     «D», «F», and «A» flags are stored in the ‘X-Status’ header.  The
     flags and headers typically appear in the order mentioned.

     ‘mboxMessage’ instances offer the following methods:

      -- Metodo: get_from ()

          Return a string representing the «From « line that marks the
          start of the message in an mbox mailbox.  The leading «From «
          and the trailing newline are excluded.

      -- Metodo: set_from (from_, time_=None)

          Set the «From « line to 'from_', which should be specified
          without a leading «From « or trailing newline.  For
          convenience, 'time_' may be specified and will be formatted
          appropriately and appended to 'from_'.  If 'time_' is
          specified, it should be a *note time.struct_time: ee8.
          instance, a tuple suitable for passing to *note
          time.strftime(): 13f1, or ‘True’ (to use *note time.gmtime():
          13c8.).

      -- Metodo: get_flags ()

          Return a string specifying the flags that are currently set.
          If the message complies with the conventional format, the
          result is the concatenation in the following order of zero or
          one occurrence of each of ‘'R'’, ‘'O'’, ‘'D'’, ‘'F'’, and
          ‘'A'’.

      -- Metodo: set_flags (flags)

          Set the flags specified by 'flags' and unset all others.
          Parameter 'flags' should be the concatenation in any order of
          zero or more occurrences of each of ‘'R'’, ‘'O'’, ‘'D'’,
          ‘'F'’, and ‘'A'’.

      -- Metodo: add_flag (flag)

          Set the flag(s) specified by 'flag' without changing other
          flags.  To add more than one flag at a time, 'flag' may be a
          string of more than one character.

      -- Metodo: remove_flag (flag)

          Unset the flag(s) specified by 'flag' without changing other
          flags.  To remove more than one flag at a time, 'flag' maybe a
          string of more than one character.

When an ‘mboxMessage’ instance is created based upon a *note
MaildirMessage: 3bff. instance, a «From « line is generated based upon
the *note MaildirMessage: 3bff. instance’s delivery date, and the
following conversions take place:

Resulting state       *note MaildirMessage: 3bff. state
                      
----------------------------------------------------------
                      
R flag                S flag
                      
                      
O flag                «cur» subdirectory
                      
                      
D flag                T flag
                      
                      
F flag                F flag
                      
                      
A flag                R flag
                      

When an ‘mboxMessage’ instance is created based upon an *note MHMessage:
3c1f. instance, the following conversions take place:

Resulting state         *note MHMessage: 3c1f. state
                        
-------------------------------------------------------
                        
R flag and O flag       no «unseen» sequence
                        
                        
O flag                  «unseen» sequence
                        
                        
F flag                  «flagged» sequence
                        
                        
A flag                  «replied» sequence
                        

When an ‘mboxMessage’ instance is created based upon a *note
BabylMessage: 3c32. instance, the following conversions take place:

Resulting state         *note BabylMessage: 3c32. state
                        
----------------------------------------------------------
                        
R flag and O flag       no «unseen» label
                        
                        
O flag                  «unseen» label
                        
                        
D flag                  «deleted» label
                        
                        
A flag                  «answered» label
                        

When a ‘mboxMessage’ instance is created based upon an *note
MMDFMessage: 3c39. instance, the «From « line is copied and all flags
directly correspond:

Resulting state       *note MMDFMessage: 3c39. state
                      
-------------------------------------------------------
                      
R flag                R flag
                      
                      
O flag                O flag
                      
                      
D flag                D flag
                      
                      
F flag                F flag
                      
                      
A flag                A flag
                      


File: python.info,  Node: MHMessage objects,  Next: BabylMessage objects,  Prev: mboxMessage objects,  Up: Message objects

5.20.3.10 ‘MHMessage’ objects
.............................

 -- Classe: mailbox.MHMessage (message=None)

     A message with MH-specific behaviors.  Parameter 'message' has the
     same meaning as with the *note Message: 1458. constructor.

     MH messages do not support marks or flags in the traditional sense,
     but they do support sequences, which are logical groupings of
     arbitrary messages.  Some mail reading programs (although not the
     standard ‘mh’ and ‘nmh’) use sequences in much the same way flags
     are used with other formats, as follows:

     Sequence       Explanation
                    
     --------------------------------------------------------------
                    
     unseen         Not read, but previously detected by MUA
                    
                    
     replied        Replied to
                    
                    
     flagged        Marked as important
                    

     ‘MHMessage’ instances offer the following methods:

      -- Metodo: get_sequences ()

          Return a list of the names of sequences that include this
          message.

      -- Metodo: set_sequences (sequences)

          Set the list of sequences that include this message.

      -- Metodo: add_sequence (sequence)

          Add 'sequence' to the list of sequences that include this
          message.

      -- Metodo: remove_sequence (sequence)

          Remove 'sequence' from the list of sequences that include this
          message.

When an ‘MHMessage’ instance is created based upon a *note
MaildirMessage: 3bff. instance, the following conversions take place:

Resulting state          *note MaildirMessage: 3bff. state
                         
-------------------------------------------------------------
                         
«unseen» sequence        no S flag
                         
                         
«replied» sequence       R flag
                         
                         
«flagged» sequence       F flag
                         

When an ‘MHMessage’ instance is created based upon an *note mboxMessage:
3aa5. or *note MMDFMessage: 3c39. instance, the ‘Status’ and ‘X-Status’
headers are omitted and the following conversions take place:

Resulting state          *note mboxMessage: 3aa5. or
                         *note MMDFMessage: 3c39. state
                         
----------------------------------------------------------------------------
                         
«unseen» sequence        no R flag
                         
                         
«replied» sequence       A flag
                         
                         
«flagged» sequence       F flag
                         

When an ‘MHMessage’ instance is created based upon a *note BabylMessage:
3c32. instance, the following conversions take place:

Resulting state          *note BabylMessage: 3c32. state
                         
-----------------------------------------------------------
                         
«unseen» sequence        «unseen» label
                         
                         
«replied» sequence       «answered» label
                         


File: python.info,  Node: BabylMessage objects,  Next: MMDFMessage objects,  Prev: MHMessage objects,  Up: Message objects

5.20.3.11 ‘BabylMessage’ objects
................................

 -- Classe: mailbox.BabylMessage (message=None)

     A message with Babyl-specific behaviors.  Parameter 'message' has
     the same meaning as with the *note Message: 1458. constructor.

     Certain message labels, called 'attributes', are defined by
     convention to have special meanings.  The attributes are as
     follows:

     Label           Explanation
                     
     ---------------------------------------------------------------
                     
     unseen          Not read, but previously detected by MUA
                     
                     
     deleted         Marked for subsequent deletion
                     
                     
     filed           Copied to another file or mailbox
                     
                     
     answered        Replied to
                     
                     
     forwarded       Forwarded
                     
                     
     edited          Modified by the user
                     
                     
     resent          Resent
                     

     By default, Rmail displays only visible headers.  The
     ‘BabylMessage’ class, though, uses the original headers because
     they are more complete.  Visible headers may be accessed explicitly
     if desired.

     ‘BabylMessage’ instances offer the following methods:

      -- Metodo: get_labels ()

          Return a list of labels on the message.

      -- Metodo: set_labels (labels)

          Set the list of labels on the message to 'labels'.

      -- Metodo: add_label (label)

          Add 'label' to the list of labels on the message.

      -- Metodo: remove_label (label)

          Remove 'label' from the list of labels on the message.

      -- Metodo: get_visible ()

          Return a *note Message: 1458. instance whose headers are the
          message’s visible headers and whose body is empty.

      -- Metodo: set_visible (visible)

          Set the message’s visible headers to be the same as the
          headers in 'message'.  Parameter 'visible' should be a *note
          Message: 1458. instance, an *note email.message.Message: 581.
          instance, a string, or a file-like object (which should be
          open in text mode).

      -- Metodo: update_visible ()

          When a ‘BabylMessage’ instance’s original headers are
          modified, the visible headers are not automatically modified
          to correspond.  This method updates the visible headers as
          follows: each visible header with a corresponding original
          header is set to the value of the original header, each
          visible header without a corresponding original header is
          removed, and any of ‘Date’, ‘From’, ‘Reply-To’, ‘To’, ‘CC’,
          and ‘Subject’ that are present in the original headers but not
          the visible headers are added to the visible headers.

When a ‘BabylMessage’ instance is created based upon a *note
MaildirMessage: 3bff. instance, the following conversions take place:

Resulting state         *note MaildirMessage: 3bff. state
                        
------------------------------------------------------------
                        
«unseen» label          no S flag
                        
                        
«deleted» label         T flag
                        
                        
«answered» label        R flag
                        
                        
«forwarded» label       P flag
                        

When a ‘BabylMessage’ instance is created based upon an *note
mboxMessage: 3aa5. or *note MMDFMessage: 3c39. instance, the ‘Status’
and ‘X-Status’ headers are omitted and the following conversions take
place:

Resulting state        *note mboxMessage: 3aa5. or
                       *note MMDFMessage: 3c39. state
                       
--------------------------------------------------------------------------
                       
«unseen» label         no R flag
                       
                       
«deleted» label        D flag
                       
                       
«answered» label       A flag
                       

When a ‘BabylMessage’ instance is created based upon an *note MHMessage:
3c1f. instance, the following conversions take place:

Resulting state        *note MHMessage: 3c1f. state
                       
------------------------------------------------------
                       
«unseen» label         «unseen» sequence
                       
                       
«answered» label       «replied» sequence
                       


File: python.info,  Node: MMDFMessage objects,  Prev: BabylMessage objects,  Up: Message objects

5.20.3.12 ‘MMDFMessage’ objects
...............................

 -- Classe: mailbox.MMDFMessage (message=None)

     A message with MMDF-specific behaviors.  Parameter 'message' has
     the same meaning as with the *note Message: 1458. constructor.

     As with message in an mbox mailbox, MMDF messages are stored with
     the sender’s address and the delivery date in an initial line
     beginning with «From «.  Likewise, flags that indicate the state of
     the message are typically stored in ‘Status’ and ‘X-Status’
     headers.

     Conventional flags for MMDF messages are identical to those of mbox
     message and are as follows:

     Flag       Meaning        Explanation
                               
     ---------------------------------------------------------------
                               
     R          Read           Read
                               
                               
     O          Old            Previously detected by MUA
                               
                               
     D          Deleted        Marked for subsequent deletion
                               
                               
     F          Flagged        Marked as important
                               
                               
     A          Answered       Replied to
                               

     The «R» and «O» flags are stored in the ‘Status’ header, and the
     «D», «F», and «A» flags are stored in the ‘X-Status’ header.  The
     flags and headers typically appear in the order mentioned.

     ‘MMDFMessage’ instances offer the following methods, which are
     identical to those offered by *note mboxMessage: 3aa5.:

      -- Metodo: get_from ()

          Return a string representing the «From « line that marks the
          start of the message in an mbox mailbox.  The leading «From «
          and the trailing newline are excluded.

      -- Metodo: set_from (from_, time_=None)

          Set the «From « line to 'from_', which should be specified
          without a leading «From « or trailing newline.  For
          convenience, 'time_' may be specified and will be formatted
          appropriately and appended to 'from_'.  If 'time_' is
          specified, it should be a *note time.struct_time: ee8.
          instance, a tuple suitable for passing to *note
          time.strftime(): 13f1, or ‘True’ (to use *note time.gmtime():
          13c8.).

      -- Metodo: get_flags ()

          Return a string specifying the flags that are currently set.
          If the message complies with the conventional format, the
          result is the concatenation in the following order of zero or
          one occurrence of each of ‘'R'’, ‘'O'’, ‘'D'’, ‘'F'’, and
          ‘'A'’.

      -- Metodo: set_flags (flags)

          Set the flags specified by 'flags' and unset all others.
          Parameter 'flags' should be the concatenation in any order of
          zero or more occurrences of each of ‘'R'’, ‘'O'’, ‘'D'’,
          ‘'F'’, and ‘'A'’.

      -- Metodo: add_flag (flag)

          Set the flag(s) specified by 'flag' without changing other
          flags.  To add more than one flag at a time, 'flag' may be a
          string of more than one character.

      -- Metodo: remove_flag (flag)

          Unset the flag(s) specified by 'flag' without changing other
          flags.  To remove more than one flag at a time, 'flag' maybe a
          string of more than one character.

When an ‘MMDFMessage’ instance is created based upon a *note
MaildirMessage: 3bff. instance, a «From « line is generated based upon
the *note MaildirMessage: 3bff. instance’s delivery date, and the
following conversions take place:

Resulting state       *note MaildirMessage: 3bff. state
                      
----------------------------------------------------------
                      
R flag                S flag
                      
                      
O flag                «cur» subdirectory
                      
                      
D flag                T flag
                      
                      
F flag                F flag
                      
                      
A flag                R flag
                      

When an ‘MMDFMessage’ instance is created based upon an *note MHMessage:
3c1f. instance, the following conversions take place:

Resulting state         *note MHMessage: 3c1f. state
                        
-------------------------------------------------------
                        
R flag and O flag       no «unseen» sequence
                        
                        
O flag                  «unseen» sequence
                        
                        
F flag                  «flagged» sequence
                        
                        
A flag                  «replied» sequence
                        

When an ‘MMDFMessage’ instance is created based upon a *note
BabylMessage: 3c32. instance, the following conversions take place:

Resulting state         *note BabylMessage: 3c32. state
                        
----------------------------------------------------------
                        
R flag and O flag       no «unseen» label
                        
                        
O flag                  «unseen» label
                        
                        
D flag                  «deleted» label
                        
                        
A flag                  «answered» label
                        

When an ‘MMDFMessage’ instance is created based upon an *note
mboxMessage: 3aa5. instance, the «From « line is copied and all flags
directly correspond:

Resulting state       *note mboxMessage: 3aa5. state
                      
-------------------------------------------------------
                      
R flag                R flag
                      
                      
O flag                O flag
                      
                      
D flag                D flag
                      
                      
F flag                F flag
                      
                      
A flag                A flag
                      


File: python.info,  Node: Exceptions<20>,  Next: Examples<24>,  Prev: Message objects,  Up: mailbox — Manipulate mailboxes in various formats

5.20.3.13 Exceptions
....................

The following exception classes are defined in the ‘mailbox’ module:

 -- Eccezione: mailbox.Error

     The based class for all other module-specific exceptions.

 -- Eccezione: mailbox.NoSuchMailboxError

     Raised when a mailbox is expected but is not found, such as when
     instantiating a *note Mailbox: 1454. subclass with a path that does
     not exist (and with the 'create' parameter set to ‘False’), or when
     opening a folder that does not exist.

 -- Eccezione: mailbox.NotEmptyError

     Raised when a mailbox is not empty but is expected to be, such as
     when deleting a folder that contains messages.

 -- Eccezione: mailbox.ExternalClashError

     Raised when some mailbox-related condition beyond the control of
     the program causes it to be unable to proceed, such as when failing
     to acquire a lock that another program already holds a lock, or
     when a uniquely generated file name already exists.

 -- Eccezione: mailbox.FormatError

     Raised when the data in a file cannot be parsed, such as when an
     *note MH: 1a15. instance attempts to read a corrupted
     ‘.mh_sequences’ file.


File: python.info,  Node: Examples<24>,  Prev: Exceptions<20>,  Up: mailbox — Manipulate mailboxes in various formats

5.20.3.14 Examples
..................

A simple example of printing the subjects of all messages in a mailbox
that seem interesting:

     import mailbox
     for message in mailbox.mbox('~/mbox'):
         subject = message['subject']       # Could possibly be None.
         if subject and 'python' in subject.lower():
             print(subject)

To copy all mail from a Babyl mailbox to an MH mailbox, converting all
of the format-specific information that can be converted:

     import mailbox
     destination = mailbox.MH('~/Mail')
     destination.lock()
     for message in mailbox.Babyl('~/RMAIL'):
         destination.add(mailbox.MHMessage(message))
     destination.flush()
     destination.unlock()

This example sorts mail from several mailing lists into different
mailboxes, being careful to avoid mail corruption due to concurrent
modification by other programs, mail loss due to interruption of the
program, or premature termination due to malformed messages in the
mailbox:

     import mailbox
     import email.errors

     list_names = ('python-list', 'python-dev', 'python-bugs')

     boxes = {name: mailbox.mbox('~/email/%s' % name) for name in list_names}
     inbox = mailbox.Maildir('~/Maildir', factory=None)

     for key in inbox.iterkeys():
         try:
             message = inbox[key]
         except email.errors.MessageParseError:
             continue                # The message is malformed. Just leave it.

         for name in list_names:
             list_id = message['list-id']
             if list_id and name in list_id:
                 # Get mailbox to use
                 box = boxes[name]

                 # Write copy to disk before removing original.
                 # If there's a crash, you might duplicate a message, but
                 # that's better than losing a message completely.
                 box.lock()
                 box.add(message)
                 box.flush()
                 box.unlock()

                 # Remove original message
                 inbox.lock()
                 inbox.discard(key)
                 inbox.flush()
                 inbox.unlock()
                 break               # Found destination, so stop looking.

     for box in boxes.itervalues():
         box.close()


File: python.info,  Node: mimetypes — Map filenames to MIME types,  Next: base64 — Base16 Base32 Base64 Base85 Data Encodings,  Prev: mailbox — Manipulate mailboxes in various formats,  Up: Internet Data Handling

5.20.4 ‘mimetypes’ — Map filenames to MIME types
------------------------------------------------

'Source code:' Lib/mimetypes.py(1)

__________________________________________________________________

The *note mimetypes: 93. module converts between a filename or URL and
the MIME type associated with the filename extension.  Conversions are
provided from filename to MIME type and from MIME type to filename
extension; encodings are not supported for the latter conversion.

The module provides one class and a number of convenience functions.
The functions are the normal interface to this module, but some
applications may be interested in the class as well.

The functions described below provide the primary interface for this
module.  If the module has not been initialized, they will call *note
init(): 3c6d. if they rely on the information *note init(): 3c6d. sets
up.

 -- Funzione: mimetypes.guess_type (url, strict=True)

     Guess the type of a file based on its filename, path or URL, given
     by 'url'.  URL can be a string or a *note path-like object: 5a1.

     The return value is a tuple ‘(type, encoding)’ where 'type' is
     ‘None’ if the type can’t be guessed (missing or unknown suffix) or
     a string of the form ‘'type/subtype'’, usable for a MIME
     ‘content-type’ header.

     'encoding' is ‘None’ for no encoding or the name of the program
     used to encode (e.g.  ‘compress’ or ‘gzip’).  The encoding is
     suitable for use as a ‘Content-Encoding’ header, 'not' as a
     ‘Content-Transfer-Encoding’ header.  The mappings are table driven.
     Encoding suffixes are case sensitive; type suffixes are first tried
     case sensitively, then case insensitively.

     The optional 'strict' argument is a flag specifying whether the
     list of known MIME types is limited to only the official types
     registered with IANA(2). However, the behavior of this module also
     depends on the underlying operating system.  Only file types
     recognized by the OS or explicitly registered with Python’s
     internal database can be identified.  When 'strict' is ‘True’ (the
     default), only the IANA types are supported; when 'strict' is
     ‘False’, some additional non-standard but commonly used MIME types
     are also recognized.

     Cambiato nella versione 3.8: Added support for 'url' being a *note
     path-like object: 5a1.

     Deprecato dalla versione 3.13: Passing a file path instead of URL
     is *note soft deprecated: 23d.  Use *note guess_file_type(): 517.
     for this.

 -- Funzione: mimetypes.guess_file_type (path, *, strict=True)

     Guess the type of a file based on its path, given by 'path'.
     Similar to the *note guess_type(): 518. function, but accepts a
     path instead of URL. Path can be a string, a bytes object or a
     *note path-like object: 5a1.

     Added in version 3.13.

 -- Funzione: mimetypes.guess_all_extensions (type, strict=True)

     Guess the extensions for a file based on its MIME type, given by
     'type'.  The return value is a list of strings giving all possible
     filename extensions, including the leading dot (‘'.'’).  The
     extensions are not guaranteed to have been associated with any
     particular data stream, but would be mapped to the MIME type 'type'
     by *note guess_type(): 518. and *note guess_file_type(): 517.

     The optional 'strict' argument has the same meaning as with the
     *note guess_type(): 518. function.

 -- Funzione: mimetypes.guess_extension (type, strict=True)

     Guess the extension for a file based on its MIME type, given by
     'type'.  The return value is a string giving a filename extension,
     including the leading dot (‘'.'’).  The extension is not guaranteed
     to have been associated with any particular data stream, but would
     be mapped to the MIME type 'type' by *note guess_type(): 518. and
     *note guess_file_type(): 517.  If no extension can be guessed for
     'type', ‘None’ is returned.

     The optional 'strict' argument has the same meaning as with the
     *note guess_type(): 518. function.

Some additional functions and data items are available for controlling
the behavior of the module.

 -- Funzione: mimetypes.init (files=None)

     Initialize the internal data structures.  If given, 'files' must be
     a sequence of file names which should be used to augment the
     default type map.  If omitted, the file names to use are taken from
     *note knownfiles: 3c6f.; on Windows, the current registry settings
     are loaded.  Each file named in 'files' or *note knownfiles: 3c6f.
     takes precedence over those named before it.  Calling *note init():
     3c6d. repeatedly is allowed.

     Specifying an empty list for 'files' will prevent the system
     defaults from being applied: only the well-known values will be
     present from a built-in list.

     If 'files' is ‘None’ the internal data structure is completely
     rebuilt to its initial default value.  This is a stable operation
     and will produce the same results when called multiple times.

     Cambiato nella versione 3.2: Previously, Windows registry settings
     were ignored.

 -- Funzione: mimetypes.read_mime_types (filename)

     Load the type map given in the file 'filename', if it exists.  The
     type map is returned as a dictionary mapping filename extensions,
     including the leading dot (‘'.'’), to strings of the form
     ‘'type/subtype'’.  If the file 'filename' does not exist or cannot
     be read, ‘None’ is returned.

 -- Funzione: mimetypes.add_type (type, ext, strict=True)

     Add a mapping from the MIME type 'type' to the extension 'ext'.
     When the extension is already known, the new type will replace the
     old one.  When the type is already known the extension will be
     added to the list of known extensions.

     When 'strict' is ‘True’ (the default), the mapping will be added to
     the official MIME types, otherwise to the non-standard ones.

 -- Dati: mimetypes.inited

     Flag indicating whether or not the global data structures have been
     initialized.  This is set to ‘True’ by *note init(): 3c6d.

 -- Dati: mimetypes.knownfiles

     List of type map file names commonly installed.  These files are
     typically named ‘mime.types’ and are installed in different
     locations by different packages.

 -- Dati: mimetypes.suffix_map

     Dictionary mapping suffixes to suffixes.  This is used to allow
     recognition of encoded files for which the encoding and the type
     are indicated by the same extension.  For example, the ‘.tgz’
     extension is mapped to ‘.tar.gz’ to allow the encoding and type to
     be recognized separately.

 -- Dati: mimetypes.encodings_map

     Dictionary mapping filename extensions to encoding types.

 -- Dati: mimetypes.types_map

     Dictionary mapping filename extensions to MIME types.

 -- Dati: mimetypes.common_types

     Dictionary mapping filename extensions to non-standard, but
     commonly found MIME types.

An example usage of the module:

     >>> import mimetypes
     >>> mimetypes.init()
     >>> mimetypes.knownfiles
     ['/etc/mime.types', '/etc/httpd/mime.types', ... ]
     >>> mimetypes.suffix_map['.tgz']
     '.tar.gz'
     >>> mimetypes.encodings_map['.gz']
     'gzip'
     >>> mimetypes.types_map['.tgz']
     'application/x-tar-gz'

* Menu:

* MimeTypes objects::
* Command-line usage: Command-line usage<4>.
* Command-line example: Command-line example<2>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/mimetypes.py

   (2) https://www.iana.org/assignments/media-types/media-types.xhtml


File: python.info,  Node: MimeTypes objects,  Next: Command-line usage<4>,  Up: mimetypes — Map filenames to MIME types

5.20.4.1 MimeTypes objects
..........................

The *note MimeTypes: 1702. class may be useful for applications which
may want more than one MIME-type database; it provides an interface
similar to the one of the *note mimetypes: 93. module.

 -- Classe: mimetypes.MimeTypes (filenames=(), strict=True)

     This class represents a MIME-types database.  By default, it
     provides access to the same database as the rest of this module.
     The initial database is a copy of that provided by the module, and
     may be extended by loading additional ‘mime.types’-style files into
     the database using the *note read(): 3c78. or *note readfp(): 3c79.
     methods.  The mapping dictionaries may also be cleared before
     loading additional data if the default data is not desired.

     The optional 'filenames' parameter can be used to cause additional
     files to be loaded «on top» of the default database.

      -- Attributo: suffix_map

          Dictionary mapping suffixes to suffixes.  This is used to
          allow recognition of encoded files for which the encoding and
          the type are indicated by the same extension.  For example,
          the ‘.tgz’ extension is mapped to ‘.tar.gz’ to allow the
          encoding and type to be recognized separately.  This is
          initially a copy of the global *note suffix_map: 3c72. defined
          in the module.

      -- Attributo: encodings_map

          Dictionary mapping filename extensions to encoding types.
          This is initially a copy of the global *note encodings_map:
          3c73. defined in the module.

      -- Attributo: types_map

          Tuple containing two dictionaries, mapping filename extensions
          to MIME types: the first dictionary is for the non-standards
          types and the second one is for the standard types.  They are
          initialized by *note common_types: 3c75. and *note types_map:
          3c74.

      -- Attributo: types_map_inv

          Tuple containing two dictionaries, mapping MIME types to a
          list of filename extensions: the first dictionary is for the
          non-standards types and the second one is for the standard
          types.  They are initialized by *note common_types: 3c75. and
          *note types_map: 3c74.

      -- Metodo: guess_extension (type, strict=True)

          Similar to the *note guess_extension(): 3c6e. function, using
          the tables stored as part of the object.

      -- Metodo: guess_type (url, strict=True)

          Similar to the *note guess_type(): 518. function, using the
          tables stored as part of the object.

      -- Metodo: guess_file_type (path, *, strict=True)

          Similar to the *note guess_file_type(): 517. function, using
          the tables stored as part of the object.

          Added in version 3.13.

      -- Metodo: guess_all_extensions (type, strict=True)

          Similar to the *note guess_all_extensions(): 1c32. function,
          using the tables stored as part of the object.

      -- Metodo: read (filename, strict=True)

          Load MIME information from a file named 'filename'.  This uses
          *note readfp(): 3c79. to parse the file.

          If 'strict' is ‘True’, information will be added to list of
          standard types, else to the list of non-standard types.

      -- Metodo: readfp (fp, strict=True)

          Load MIME type information from an open file 'fp'.  The file
          must have the format of the standard ‘mime.types’ files.

          If 'strict' is ‘True’, information will be added to the list
          of standard types, else to the list of non-standard types.

      -- Metodo: read_windows_registry (strict=True)

          Load MIME type information from the Windows registry.

          *note Availability: 2128.: Windows.

          If 'strict' is ‘True’, information will be added to the list
          of standard types, else to the list of non-standard types.

          Added in version 3.2.

      -- Metodo: add_type (type, ext, strict=True)

          Add a mapping from the MIME type 'type' to the extension
          'ext'.  Valid extensions start with a “.” or are empty.  When
          the extension is already known, the new type will replace the
          old one.  When the type is already known the extension will be
          added to the list of known extensions.

          When 'strict' is ‘True’ (the default), the mapping will be
          added to the official MIME types, otherwise to the
          non-standard ones.

          Deprecated since version 3.14, will be removed in version
          3.16: Invalid, undotted extensions will raise a *note
          ValueError: 2ec. in Python 3.16.


File: python.info,  Node: Command-line usage<4>,  Next: Command-line example<2>,  Prev: MimeTypes objects,  Up: mimetypes — Map filenames to MIME types

5.20.4.2 Command-line usage
...........................

The ‘mimetypes’ module can be executed as a script from the command
line.

     python -m mimetypes [-h] [-e] [-l] type [type ...]

The following options are accepted:

 -- Opzione Del Programma: -h
 -- Opzione Del Programma: --help

     Show the help message and exit.

 -- Opzione Del Programma: -e
 -- Opzione Del Programma: --extension

     Guess extension instead of type.

 -- Opzione Del Programma: -l
 -- Opzione Del Programma: --lenient

     Additionally search for some common, but non-standard types.

By default the script converts MIME types to file extensions.  However,
if ‘--extension’ is specified, it converts file extensions to MIME
types.

For each ‘type’ entry, the script writes a line into the standard output
stream.  If an unknown type occurs, it writes an error message into the
standard error stream and exits with the return code ‘1’.


File: python.info,  Node: Command-line example<2>,  Prev: Command-line usage<4>,  Up: mimetypes — Map filenames to MIME types

5.20.4.3 Command-line example
.............................

Here are some examples of typical usage of the ‘mimetypes’ command-line
interface:

     $ # get a MIME type by a file name
     $ python -m mimetypes filename.png
     type: image/png encoding: None

     $ # get a MIME type by a URL
     $ python -m mimetypes https://example.com/filename.txt
     type: text/plain encoding: None

     $ # get a complex MIME type
     $ python -m mimetypes filename.tar.gz
     type: application/x-tar encoding: gzip

     $ # get a MIME type for a rare file extension
     $ python -m mimetypes filename.pict
     error: unknown extension of filename.pict

     $ # now look in the extended database built into Python
     $ python -m mimetypes --lenient filename.pict
     type: image/pict encoding: None

     $ # get a file extension by a MIME type
     $ python -m mimetypes --extension text/javascript
     .js

     $ # get a file extension by a rare MIME type
     $ python -m mimetypes --extension text/xul
     error: unknown type text/xul

     $ # now look in the extended database again
     $ python -m mimetypes --extension --lenient text/xul
     .xul

     $ # try to feed an unknown file extension
     $ python -m mimetypes filename.sh filename.nc filename.xxx filename.txt
     type: application/x-sh encoding: None
     type: application/x-netcdf encoding: None
     error: unknown extension of filename.xxx

     $ # try to feed an unknown MIME type
     $ python -m mimetypes --extension audio/aac audio/opus audio/future audio/x-wav
     .aac
     .opus
     error: unknown type audio/future


File: python.info,  Node: base64 — Base16 Base32 Base64 Base85 Data Encodings,  Next: binascii — Convert between binary and ASCII,  Prev: mimetypes — Map filenames to MIME types,  Up: Internet Data Handling

5.20.5 ‘base64’ — Base16, Base32, Base64, Base85 Data Encodings
---------------------------------------------------------------

'Source code:' Lib/base64.py(1)

__________________________________________________________________

This module provides functions for encoding binary data to printable
ASCII characters and decoding such encodings back to binary data.  This
includes the *note encodings specified in: 3c8d. RFC 4648(2) (Base64,
Base32 and Base16) and the non-standard *note Base85 encodings: 3c8e.

There are two interfaces provided by this module.  The modern interface
supports encoding *note bytes-like objects: 193. to ASCII *note bytes:
192, and decoding *note bytes-like objects: 193. or strings containing
ASCII to *note bytes: 192.  Both base-64 alphabets defined in RFC
4648(3) (normal, and URL- and filesystem-safe) are supported.

The *note legacy interface: 3c8f. does not support decoding from
strings, but it does provide functions for encoding and decoding to and
from *note file objects: 13cb.  It only supports the Base64 standard
alphabet, and it adds newlines every 76 characters as per RFC 2045(4).
Note that if you are looking for RFC 2045(5) support you probably want
to be looking at the *note email: 3f. package instead.

Cambiato nella versione 3.3: ASCII-only Unicode strings are now accepted
by the decoding functions of the modern interface.

Cambiato nella versione 3.4: Any *note bytes-like objects: 193. are now
accepted by all encoding and decoding functions in this module.
Ascii85/Base85 support added.

* Menu:

* RFC 4648 Encodings::
* Base85 Encodings::
* Legacy Interface::
* Security Considerations: Security Considerations<2>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/base64.py

   (2) https://datatracker.ietf.org/doc/html/rfc4648.html

   (3) https://datatracker.ietf.org/doc/html/rfc4648.html

   (4) https://datatracker.ietf.org/doc/html/rfc2045.html

   (5) https://datatracker.ietf.org/doc/html/rfc2045.html


File: python.info,  Node: RFC 4648 Encodings,  Next: Base85 Encodings,  Up: base64 — Base16 Base32 Base64 Base85 Data Encodings

5.20.5.1 RFC 4648 Encodings
...........................

The RFC 4648(1) encodings are suitable for encoding binary data so that
it can be safely sent by email, used as parts of URLs, or included as
part of an HTTP POST request.

 -- Funzione: base64.b64encode (s, altchars=None)

     Encode the *note bytes-like object: 193. 's' using Base64 and
     return the encoded *note bytes: 192.

     Optional 'altchars' must be a *note bytes-like object: 193. of
     length 2 which specifies an alternative alphabet for the ‘+’ and
     ‘/’ characters.  This allows an application to e.g.  generate URL
     or filesystem safe Base64 strings.  The default is ‘None’, for
     which the standard Base64 alphabet is used.

     May assert or raise a *note ValueError: 2ec. if the length of
     'altchars' is not 2.  Raises a *note TypeError: 198. if 'altchars'
     is not a *note bytes-like object: 193.

 -- Funzione: base64.b64decode (s, altchars=None, validate=False)

     Decode the Base64 encoded *note bytes-like object: 193. or ASCII
     string 's' and return the decoded *note bytes: 192.

     Optional 'altchars' must be a *note bytes-like object: 193. or
     ASCII string of length 2 which specifies the alternative alphabet
     used instead of the ‘+’ and ‘/’ characters.

     A *note binascii.Error: 1228. exception is raised if 's' is
     incorrectly padded.

     If 'validate' is ‘False’ (the default), characters that are neither
     in the normal base-64 alphabet nor the alternative alphabet are
     discarded prior to the padding check.  If 'validate' is ‘True’,
     these non-alphabet characters in the input result in a *note
     binascii.Error: 1228.

     For more information about the strict base64 check, see *note
     binascii.a2b_base64(): 198c.

     May assert or raise a *note ValueError: 2ec. if the length of
     'altchars' is not 2.

 -- Funzione: base64.standard_b64encode (s)

     Encode *note bytes-like object: 193. 's' using the standard Base64
     alphabet and return the encoded *note bytes: 192.

 -- Funzione: base64.standard_b64decode (s)

     Decode *note bytes-like object: 193. or ASCII string 's' using the
     standard Base64 alphabet and return the decoded *note bytes: 192.

 -- Funzione: base64.urlsafe_b64encode (s)

     Encode *note bytes-like object: 193. 's' using the URL- and
     filesystem-safe alphabet, which substitutes ‘-’ instead of ‘+’ and
     ‘_’ instead of ‘/’ in the standard Base64 alphabet, and return the
     encoded *note bytes: 192.  The result can still contain ‘=’.

 -- Funzione: base64.urlsafe_b64decode (s)

     Decode *note bytes-like object: 193. or ASCII string 's' using the
     URL- and filesystem-safe alphabet, which substitutes ‘-’ instead of
     ‘+’ and ‘_’ instead of ‘/’ in the standard Base64 alphabet, and
     return the decoded *note bytes: 192.

 -- Funzione: base64.b32encode (s)

     Encode the *note bytes-like object: 193. 's' using Base32 and
     return the encoded *note bytes: 192.

 -- Funzione: base64.b32decode (s, casefold=False, map01=None)

     Decode the Base32 encoded *note bytes-like object: 193. or ASCII
     string 's' and return the decoded *note bytes: 192.

     Optional 'casefold' is a flag specifying whether a lowercase
     alphabet is acceptable as input.  For security purposes, the
     default is ‘False’.

     RFC 4648(2) allows for optional mapping of the digit 0 (zero) to
     the letter O (oh), and for optional mapping of the digit 1 (one) to
     either the letter I (eye) or letter L (el).  The optional argument
     'map01' when not ‘None’, specifies which letter the digit 1 should
     be mapped to (when 'map01' is not ‘None’, the digit 0 is always
     mapped to the letter O). For security purposes the default is
     ‘None’, so that 0 and 1 are not allowed in the input.

     A *note binascii.Error: 1228. is raised if 's' is incorrectly
     padded or if there are non-alphabet characters present in the
     input.

 -- Funzione: base64.b32hexencode (s)

     Similar to *note b32encode(): 3c96. but uses the Extended Hex
     Alphabet, as defined in RFC 4648(3).

     Added in version 3.10.

 -- Funzione: base64.b32hexdecode (s, casefold=False)

     Similar to *note b32decode(): 1227. but uses the Extended Hex
     Alphabet, as defined in RFC 4648(4).

     This version does not allow the digit 0 (zero) to the letter O (oh)
     and digit 1 (one) to either the letter I (eye) or letter L (el)
     mappings, all these characters are included in the Extended Hex
     Alphabet and are not interchangeable.

     Added in version 3.10.

 -- Funzione: base64.b16encode (s)

     Encode the *note bytes-like object: 193. 's' using Base16 and
     return the encoded *note bytes: 192.

 -- Funzione: base64.b16decode (s, casefold=False)

     Decode the Base16 encoded *note bytes-like object: 193. or ASCII
     string 's' and return the decoded *note bytes: 192.

     Optional 'casefold' is a flag specifying whether a lowercase
     alphabet is acceptable as input.  For security purposes, the
     default is ‘False’.

     A *note binascii.Error: 1228. is raised if 's' is incorrectly
     padded or if there are non-alphabet characters present in the
     input.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc4648.html

   (2) https://datatracker.ietf.org/doc/html/rfc4648.html

   (3) https://datatracker.ietf.org/doc/html/rfc4648.html

   (4) https://datatracker.ietf.org/doc/html/rfc4648.html


File: python.info,  Node: Base85 Encodings,  Next: Legacy Interface,  Prev: RFC 4648 Encodings,  Up: base64 — Base16 Base32 Base64 Base85 Data Encodings

5.20.5.2 Base85 Encodings
.........................

Base85 encoding is not formally specified but rather a de facto
standard, thus different systems perform the encoding differently.

The *note a85encode(): 1122. and *note b85encode(): 1124. functions in
this module are two implementations of the de facto standard.  You
should call the function with the Base85 implementation used by the
software you intend to work with.

The two functions present in this module differ in how they handle the
following:

   * Whether to include enclosing ‘<~’ and ‘~>’ markers

   * Whether to include newline characters

   * The set of ASCII characters used for encoding

   * Handling of null bytes

Refer to the documentation of the individual functions for more
information.

 -- Funzione: base64.a85encode (b, *, foldspaces=False, wrapcol=0,
          pad=False, adobe=False)

     Encode the *note bytes-like object: 193. 'b' using Ascii85 and
     return the encoded *note bytes: 192.

     'foldspaces' is an optional flag that uses the special short
     sequence “y” instead of 4 consecutive spaces (ASCII 0x20) as
     supported by “btoa”.  This feature is not supported by the
     «standard» Ascii85 encoding.

     'wrapcol' controls whether the output should have newline (‘b'\n'’)
     characters added to it.  If this is non-zero, each output line will
     be at most this many characters long, excluding the trailing
     newline.

     'pad' controls whether the input is padded to a multiple of 4
     before encoding.  Note that the ‘btoa’ implementation always pads.

     'adobe' controls whether the encoded byte sequence is framed with
     ‘<~’ and ‘~>’, which is used by the Adobe implementation.

     Added in version 3.4.

 -- Funzione: base64.a85decode (b, *, foldspaces=False, adobe=False,
          ignorechars=b' \t\n\r\x0b')

     Decode the Ascii85 encoded *note bytes-like object: 193. or ASCII
     string 'b' and return the decoded *note bytes: 192.

     'foldspaces' is a flag that specifies whether the “y” short
     sequence should be accepted as shorthand for 4 consecutive spaces
     (ASCII 0x20).  This feature is not supported by the «standard»
     Ascii85 encoding.

     'adobe' controls whether the input sequence is in Adobe Ascii85
     format (i.e.  is framed with <~ and ~>).

     'ignorechars' should be a byte string containing characters to
     ignore from the input.  This should only contain whitespace
     characters, and by default contains all whitespace characters in
     ASCII.

     Added in version 3.4.

 -- Funzione: base64.b85encode (b, pad=False)

     Encode the *note bytes-like object: 193. 'b' using base85 (as used
     in e.g.  git-style binary diffs) and return the encoded *note
     bytes: 192.

     If 'pad' is true, the input is padded with ‘b'\0'’ so its length is
     a multiple of 4 bytes before encoding.

     Added in version 3.4.

 -- Funzione: base64.b85decode (b)

     Decode the base85-encoded *note bytes-like object: 193. or ASCII
     string 'b' and return the decoded *note bytes: 192.  Padding is
     implicitly removed, if necessary.

     Added in version 3.4.

 -- Funzione: base64.z85encode (s)

     Encode the *note bytes-like object: 193. 's' using Z85 (as used in
     ZeroMQ) and return the encoded *note bytes: 192.  See Z85
     specification(1) for more information.

     Added in version 3.13.

 -- Funzione: base64.z85decode (s)

     Decode the Z85-encoded *note bytes-like object: 193. or ASCII
     string 's' and return the decoded *note bytes: 192.  See Z85
     specification(2) for more information.

     Added in version 3.13.

   ---------- Footnotes ----------

   (1) https://rfc.zeromq.org/spec/32/

   (2) https://rfc.zeromq.org/spec/32/


File: python.info,  Node: Legacy Interface,  Next: Security Considerations<2>,  Prev: Base85 Encodings,  Up: base64 — Base16 Base32 Base64 Base85 Data Encodings

5.20.5.3 Legacy Interface
.........................

 -- Funzione: base64.decode (input, output)

     Decode the contents of the binary 'input' file and write the
     resulting binary data to the 'output' file.  'input' and 'output'
     must be *note file objects: 13cb.  'input' will be read until
     ‘input.readline()’ returns an empty bytes object.

 -- Funzione: base64.decodebytes (s)

     Decode the *note bytes-like object: 193. 's', which must contain
     one or more lines of base64 encoded data, and return the decoded
     *note bytes: 192.

     Added in version 3.1.

 -- Funzione: base64.encode (input, output)

     Encode the contents of the binary 'input' file and write the
     resulting base64 encoded data to the 'output' file.  'input' and
     'output' must be *note file objects: 13cb.  'input' will be read
     until ‘input.read()’ returns an empty bytes object.  *note
     encode(): 3c9b. inserts a newline character (‘b'\n'’) after every
     76 bytes of the output, as well as ensuring that the output always
     ends with a newline, as per RFC 2045(1) (MIME).

 -- Funzione: base64.encodebytes (s)

     Encode the *note bytes-like object: 193. 's', which can contain
     arbitrary binary data, and return *note bytes: 192. containing the
     base64-encoded data, with newlines (‘b'\n'’) inserted after every
     76 bytes of output, and ensuring that there is a trailing newline,
     as per RFC 2045(2) (MIME).

     Added in version 3.1.

An example usage of the module:

     >>> import base64
     >>> encoded = base64.b64encode(b'data to be encoded')
     >>> encoded
     b'ZGF0YSB0byBiZSBlbmNvZGVk'
     >>> data = base64.b64decode(encoded)
     >>> data
     b'data to be encoded'

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2045.html

   (2) https://datatracker.ietf.org/doc/html/rfc2045.html


File: python.info,  Node: Security Considerations<2>,  Prev: Legacy Interface,  Up: base64 — Base16 Base32 Base64 Base85 Data Encodings

5.20.5.4 Security Considerations
................................

A new security considerations section was added to RFC 4648(1) (section
12); it’s recommended to review the security section for any code
deployed to production.

Vedi anche
..........

Module *note binascii: 11.

     Support module containing ASCII-to-binary and binary-to-ASCII
     conversions.

RFC 1521(2) - MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies

     Section 5.2, «Base64 Content-Transfer-Encoding,» provides the
     definition of the base64 encoding.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc4648.html

   (2) https://datatracker.ietf.org/doc/html/rfc1521.html


File: python.info,  Node: binascii — Convert between binary and ASCII,  Next: quopri — Encode and decode MIME quoted-printable data,  Prev: base64 — Base16 Base32 Base64 Base85 Data Encodings,  Up: Internet Data Handling

5.20.6 ‘binascii’ — Convert between binary and ASCII
----------------------------------------------------

__________________________________________________________________

The *note binascii: 11. module contains a number of methods to convert
between binary and various ASCII-encoded binary representations.
Normally, you will not use these functions directly but use wrapper
modules like *note base64: f. instead.  The *note binascii: 11. module
contains low-level functions written in C for greater speed that are
used by the higher-level modules.

     Nota: ‘a2b_*’ functions accept Unicode strings containing only
     ASCII characters.  Other functions only accept *note bytes-like
     objects: 193. (such as *note bytes: 192, *note bytearray: 344. and
     other objects that support the buffer protocol).

     Cambiato nella versione 3.3: ASCII-only unicode strings are now
     accepted by the ‘a2b_*’ functions.

The *note binascii: 11. module defines the following functions:

 -- Funzione: binascii.a2b_uu (string)

     Convert a single line of uuencoded data back to binary and return
     the binary data.  Lines normally contain 45 (binary) bytes, except
     for the last line.  Line data may be followed by whitespace.

 -- Funzione: binascii.b2a_uu (data, *, backtick=False)

     Convert binary data to a line of ASCII characters, the return value
     is the converted line, including a newline char.  The length of
     'data' should be at most 45.  If 'backtick' is true, zeros are
     represented by ‘'`'’ instead of spaces.

     Cambiato nella versione 3.7: Added the 'backtick' parameter.

 -- Funzione: binascii.a2b_base64 (string, /, *, strict_mode=False)

     Convert a block of base64 data back to binary and return the binary
     data.  More than one line may be passed at a time.

     If 'strict_mode' is true, only valid base64 data will be converted.
     Invalid base64 data will raise *note binascii.Error: 1228.

     Valid base64:

        * Conforms to RFC 3548(1).

        * Contains only characters from the base64 alphabet.

        * Contains no excess data after padding (including excess
          padding, newlines, etc.).

        * Does not start with a padding.

     Cambiato nella versione 3.11: Added the 'strict_mode' parameter.

 -- Funzione: binascii.b2a_base64 (data, *, newline=True)

     Convert binary data to a line of ASCII characters in base64 coding.
     The return value is the converted line, including a newline char if
     'newline' is true.  The output of this function conforms to RFC
     3548(2).

     Cambiato nella versione 3.6: Added the 'newline' parameter.

 -- Funzione: binascii.a2b_qp (data, header=False)

     Convert a block of quoted-printable data back to binary and return
     the binary data.  More than one line may be passed at a time.  If
     the optional argument 'header' is present and true, underscores
     will be decoded as spaces.

 -- Funzione: binascii.b2a_qp (data, quotetabs=False, istext=True,
          header=False)

     Convert binary data to a line(s) of ASCII characters in
     quoted-printable encoding.  The return value is the converted
     line(s).  If the optional argument 'quotetabs' is present and true,
     all tabs and spaces will be encoded.  If the optional argument
     'istext' is present and true, newlines are not encoded but trailing
     whitespace will be encoded.  If the optional argument 'header' is
     present and true, spaces will be encoded as underscores per RFC
     1522(3).  If the optional argument 'header' is present and false,
     newline characters will be encoded as well; otherwise linefeed
     conversion might corrupt the binary data stream.

 -- Funzione: binascii.crc_hqx (data, value)

     Compute a 16-bit CRC value of 'data', starting with 'value' as the
     initial CRC, and return the result.  This uses the CRC-CCITT
     polynomial 'x'^16 + 'x'^12 + 'x'^5 + 1, often represented as
     0x1021.  This CRC is used in the binhex4 format.

 -- Funzione: binascii.crc32 (data[, value])

     Compute CRC-32, the unsigned 32-bit checksum of 'data', starting
     with an initial CRC of 'value'.  The default initial CRC is zero.
     The algorithm is consistent with the ZIP file checksum.  Since the
     algorithm is designed for use as a checksum algorithm, it is not
     suitable for use as a general hash algorithm.  Use as follows:

          print(binascii.crc32(b"hello world"))
          # Or, in two pieces:
          crc = binascii.crc32(b"hello")
          crc = binascii.crc32(b" world", crc)
          print('crc32 = {:#010x}'.format(crc))

     Cambiato nella versione 3.0: The result is always unsigned.

 -- Funzione: binascii.b2a_hex (data[, sep[, bytes_per_sep=1]])
 -- Funzione: binascii.hexlify (data[, sep[, bytes_per_sep=1]])

     Return the hexadecimal representation of the binary 'data'.  Every
     byte of 'data' is converted into the corresponding 2-digit hex
     representation.  The returned bytes object is therefore twice as
     long as the length of 'data'.

     Similar functionality (but returning a text string) is also
     conveniently accessible using the *note bytes.hex(): f67. method.

     If 'sep' is specified, it must be a single character str or bytes
     object.  It will be inserted in the output after every
     'bytes_per_sep' input bytes.  Separator placement is counted from
     the right end of the output by default, if you wish to count from
     the left, supply a negative 'bytes_per_sep' value.

          >>> import binascii
          >>> binascii.b2a_hex(b'\xb9\x01\xef')
          b'b901ef'
          >>> binascii.hexlify(b'\xb9\x01\xef', '-')
          b'b9-01-ef'
          >>> binascii.b2a_hex(b'\xb9\x01\xef', b'_', 2)
          b'b9_01ef'
          >>> binascii.b2a_hex(b'\xb9\x01\xef', b' ', -2)
          b'b901 ef'

     Cambiato nella versione 3.8: The 'sep' and 'bytes_per_sep'
     parameters were added.

 -- Funzione: binascii.a2b_hex (hexstr)
 -- Funzione: binascii.unhexlify (hexstr)

     Return the binary data represented by the hexadecimal string
     'hexstr'.  This function is the inverse of *note b2a_hex(): 2862.
     'hexstr' must contain an even number of hexadecimal digits (which
     can be upper or lower case), otherwise an *note Error: 1228.
     exception is raised.

     Similar functionality (accepting only text string arguments, but
     more liberal towards whitespace) is also accessible using the *note
     bytes.fromhex(): 190. class method.

 -- Eccezione: binascii.Error

     Exception raised on errors.  These are usually programming errors.

 -- Eccezione: binascii.Incomplete

     Exception raised on incomplete data.  These are usually not
     programming errors, but may be handled by reading a little more
     data and trying again.

Vedi anche
..........

Module *note base64: f.

     Support for RFC compliant base64-style encoding in base 16, 32, 64,
     and 85.

Module *note quopri: bc.

     Support for quoted-printable encoding used in MIME email messages.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc3548.html

   (2) https://datatracker.ietf.org/doc/html/rfc3548.html

   (3) https://datatracker.ietf.org/doc/html/rfc1522.html


File: python.info,  Node: quopri — Encode and decode MIME quoted-printable data,  Prev: binascii — Convert between binary and ASCII,  Up: Internet Data Handling

5.20.7 ‘quopri’ — Encode and decode MIME quoted-printable data
--------------------------------------------------------------

'Source code:' Lib/quopri.py(1)

__________________________________________________________________

This module performs quoted-printable transport encoding and decoding,
as defined in RFC 1521(2): «MIME (Multipurpose Internet Mail Extensions)
Part One: Mechanisms for Specifying and Describing the Format of
Internet Message Bodies».  The quoted-printable encoding is designed for
data where there are relatively few nonprintable characters; the base64
encoding scheme available via the *note base64: f. module is more
compact if there are many such characters, as when sending a graphics
file.

 -- Funzione: quopri.decode (input, output, header=False)

     Decode the contents of the 'input' file and write the resulting
     decoded binary data to the 'output' file.  'input' and 'output'
     must be *note binary file objects: 13cb.  If the optional argument
     'header' is present and true, underscore will be decoded as space.
     This is used to decode «Q»-encoded headers as described in RFC
     1522(3): «MIME (Multipurpose Internet Mail Extensions) Part Two:
     Message Header Extensions for Non-ASCII Text».

 -- Funzione: quopri.encode (input, output, quotetabs, header=False)

     Encode the contents of the 'input' file and write the resulting
     quoted-printable data to the 'output' file.  'input' and 'output'
     must be *note binary file objects: 13cb.  'quotetabs', a
     non-optional flag which controls whether to encode embedded spaces
     and tabs; when true it encodes such embedded whitespace, and when
     false it leaves them unencoded.  Note that spaces and tabs
     appearing at the end of lines are always encoded, as per RFC
     1521(4).  'header' is a flag which controls if spaces are encoded
     as underscores as per RFC 1522(5).

 -- Funzione: quopri.decodestring (s, header=False)

     Like *note decode(): 2865, except that it accepts a source *note
     bytes: 192. and returns the corresponding decoded *note bytes: 192.

 -- Funzione: quopri.encodestring (s, quotetabs=False, header=False)

     Like *note encode(): 2864, except that it accepts a source *note
     bytes: 192. and returns the corresponding encoded *note bytes: 192.
     By default, it sends a ‘False’ value to 'quotetabs' parameter of
     the *note encode(): 2864. function.

Vedi anche
..........

Module *note base64: f.

     Encode and decode MIME base64 data

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/quopri.py

   (2) https://datatracker.ietf.org/doc/html/rfc1521.html

   (3) https://datatracker.ietf.org/doc/html/rfc1522.html

   (4) https://datatracker.ietf.org/doc/html/rfc1521.html

   (5) https://datatracker.ietf.org/doc/html/rfc1522.html


File: python.info,  Node: Structured Markup Processing Tools,  Next: Internet Protocols and Support,  Prev: Internet Data Handling,  Up: The Python Standard Library

5.21 Structured Markup Processing Tools
=======================================

Python supports a variety of modules to work with various forms of
structured data markup.  This includes modules to work with the Standard
Generalized Markup Language (SGML) and the Hypertext Markup Language
(HTML), and several interfaces for working with the Extensible Markup
Language (XML).

* Menu:

* html — HyperText Markup Language support::
* html.parser — Simple HTML and XHTML parser: html parser — Simple HTML and XHTML parser.
* html.entities — Definitions of HTML general entities: html entities — Definitions of HTML general entities.
* XML Processing Modules::
* xml.etree.ElementTree — The ElementTree XML API: xml etree ElementTree — The ElementTree XML API.
* xml.dom — The Document Object Model API: xml dom — The Document Object Model API.
* xml.dom.minidom — Minimal DOM implementation: xml dom minidom — Minimal DOM implementation.
* xml.dom.pulldom — Support for building partial DOM trees: xml dom pulldom — Support for building partial DOM trees.
* xml.sax — Support for SAX2 parsers: xml sax — Support for SAX2 parsers.
* xml.sax.handler — Base classes for SAX handlers: xml sax handler — Base classes for SAX handlers.
* xml.sax.saxutils — SAX Utilities: xml sax saxutils — SAX Utilities.
* xml.sax.xmlreader — Interface for XML parsers: xml sax xmlreader — Interface for XML parsers.
* xml.parsers.expat — Fast XML parsing using Expat: xml parsers expat — Fast XML parsing using Expat.


File: python.info,  Node: html — HyperText Markup Language support,  Next: html parser — Simple HTML and XHTML parser,  Up: Structured Markup Processing Tools

5.21.1 ‘html’ — HyperText Markup Language support
-------------------------------------------------

'Source code:' Lib/html/__init__.py(1)

__________________________________________________________________

This module defines utilities to manipulate HTML.

 -- Funzione: html.escape (s, quote=True)

     Convert the characters ‘&’, ‘<’ and ‘>’ in string 's' to HTML-safe
     sequences.  Use this if you need to display text that might contain
     such characters in HTML. If the optional flag 'quote' is true (the
     default), the characters (‘"’) and (‘'’) are also translated; this
     helps for inclusion in an HTML attribute value delimited by quotes,
     as in ‘<a href="...">’.  If 'quote' is set to false, the characters
     (‘"’) and (‘'’) are not translated.

     Added in version 3.2.

 -- Funzione: html.unescape (s)

     Convert all named and numeric character references (e.g.  ‘&gt;’,
     ‘&#62;’, ‘&#x3e;’) in the string 's' to the corresponding Unicode
     characters.  This function uses the rules defined by the HTML 5
     standard for both valid and invalid character references, and the
     *note list of HTML 5 named character references: 12da.

     Added in version 3.4.

__________________________________________________________________

Submodules in the ‘html’ package are:

   * *note html.parser: 71. – HTML/XHTML parser with lenient parsing
     mode

   * *note html.entities: 70. – HTML entity definitions

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/html/__init__.py


File: python.info,  Node: html parser — Simple HTML and XHTML parser,  Next: html entities — Definitions of HTML general entities,  Prev: html — HyperText Markup Language support,  Up: Structured Markup Processing Tools

5.21.2 ‘html.parser’ — Simple HTML and XHTML parser
---------------------------------------------------

'Source code:' Lib/html/parser.py(1)

__________________________________________________________________

This module defines a class *note HTMLParser: a79. which serves as the
basis for parsing text files formatted in HTML (HyperText Mark-up
Language) and XHTML.

 -- Classe: html.parser.HTMLParser (*, convert_charrefs=True,
          scripting=False)

     Create a parser instance able to parse invalid markup.

     If 'convert_charrefs' is true (the default), all character
     references (except the ones in elements like ‘script’ and ‘style’)
     are automatically converted to the corresponding Unicode
     characters.

     If 'scripting' is false (the default), the content of the
     ‘noscript’ element is parsed normally; if it’s true, it’s returned
     as is without being parsed.

     An *note HTMLParser: a79. instance is fed HTML data and calls
     handler methods when start tags, end tags, text, comments, and
     other markup elements are encountered.  The user should subclass
     *note HTMLParser: a79. and override its methods to implement the
     desired behavior.

     This parser does not check that end tags match start tags or call
     the end-tag handler for elements which are closed implicitly by
     closing an outer element.

     Cambiato nella versione 3.4: 'convert_charrefs' keyword argument
     added.

     Cambiato nella versione 3.5: The default value for argument
     'convert_charrefs' is now ‘True’.

     Cambiato nella versione 3.14.1: Added the 'scripting' parameter.

* Menu:

* Example HTML Parser Application::
* HTMLParser Methods::
* Examples: Examples<25>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/html/parser.py


File: python.info,  Node: Example HTML Parser Application,  Next: HTMLParser Methods,  Up: html parser — Simple HTML and XHTML parser

5.21.2.1 Example HTML Parser Application
........................................

As a basic example, below is a simple HTML parser that uses the *note
HTMLParser: a79. class to print out start tags, end tags, and data as
they are encountered:

     from html.parser import HTMLParser

     class MyHTMLParser(HTMLParser):
         def handle_starttag(self, tag, attrs):
             print("Encountered a start tag:", tag)

         def handle_endtag(self, tag):
             print("Encountered an end tag :", tag)

         def handle_data(self, data):
             print("Encountered some data  :", data)

     parser = MyHTMLParser()
     parser.feed('<html><head><title>Test</title></head>'
                 '<body><h1>Parse me!</h1></body></html>')

The output will then be:

     Encountered a start tag: html
     Encountered a start tag: head
     Encountered a start tag: title
     Encountered some data  : Test
     Encountered an end tag : title
     Encountered an end tag : head
     Encountered a start tag: body
     Encountered a start tag: h1
     Encountered some data  : Parse me!
     Encountered an end tag : h1
     Encountered an end tag : body
     Encountered an end tag : html


File: python.info,  Node: HTMLParser Methods,  Next: Examples<25>,  Prev: Example HTML Parser Application,  Up: html parser — Simple HTML and XHTML parser

5.21.2.2 ‘HTMLParser’ Methods
.............................

*note HTMLParser: a79. instances have the following methods:

 -- Metodo: HTMLParser.feed (data)

     Feed some text to the parser.  It is processed insofar as it
     consists of complete elements; incomplete data is buffered until
     more data is fed or *note close(): 1829. is called.  'data' must be
     *note str: 169.

 -- Metodo: HTMLParser.close ()

     Force processing of all buffered data as if it were followed by an
     end-of-file mark.  This method may be redefined by a derived class
     to define additional processing at the end of the input, but the
     redefined version should always call the *note HTMLParser: a79.
     base class method *note close(): 1829.

 -- Metodo: HTMLParser.reset ()

     Reset the instance.  Loses all unprocessed data.  This is called
     implicitly at instantiation time.

 -- Metodo: HTMLParser.getpos ()

     Return current line number and offset.

 -- Metodo: HTMLParser.get_starttag_text ()

     Return the text of the most recently opened start tag.  This should
     not normally be needed for structured processing, but may be useful
     in dealing with HTML «as deployed» or for re-generating input with
     minimal changes (whitespace between attributes can be preserved,
     etc.).

The following methods are called when data or markup elements are
encountered and they are meant to be overridden in a subclass.  The base
class implementations do nothing (except for *note handle_startendtag():
3cba.):

 -- Metodo: HTMLParser.handle_starttag (tag, attrs)

     This method is called to handle the start tag of an element (e.g.
     ‘<div id="main">’).

     The 'tag' argument is the name of the tag converted to lower case.
     The 'attrs' argument is a list of ‘(name, value)’ pairs containing
     the attributes found inside the tag’s ‘<>’ brackets.  The 'name'
     will be translated to lower case, and quotes in the 'value' have
     been removed, and character and entity references have been
     replaced.

     For instance, for the tag ‘<A HREF="https://www.cwi.nl/">’, this
     method would be called as ‘handle_starttag('a', [('href',
     'https://www.cwi.nl/')])’.

     All entity references from *note html.entities: 70. are replaced in
     the attribute values.

 -- Metodo: HTMLParser.handle_endtag (tag)

     This method is called to handle the end tag of an element (e.g.
     ‘</div>’).

     The 'tag' argument is the name of the tag converted to lower case.

 -- Metodo: HTMLParser.handle_startendtag (tag, attrs)

     Similar to *note handle_starttag(): 3cbb, but called when the
     parser encounters an XHTML-style empty tag (‘<img ... />’).  This
     method may be overridden by subclasses which require this
     particular lexical information; the default implementation simply
     calls *note handle_starttag(): 3cbb. and *note handle_endtag():
     3cbc.

 -- Metodo: HTMLParser.handle_data (data)

     This method is called to process arbitrary data (e.g.  text nodes
     and the content of elements like ‘script’ and ‘style’).

 -- Metodo: HTMLParser.handle_entityref (name)

     This method is called to process a named character reference of the
     form ‘&name;’ (e.g.  ‘&gt;’), where 'name' is a general entity
     reference (e.g.  ‘'gt'’).  This method is only called if
     'convert_charrefs' is false.

 -- Metodo: HTMLParser.handle_charref (name)

     This method is called to process decimal and hexadecimal numeric
     character references of the form ‘&#NNN;’ and ‘&#xNNN;’.  For
     example, the decimal equivalent for ‘&gt;’ is ‘&#62;’, whereas the
     hexadecimal is ‘&#x3E;’; in this case the method will receive
     ‘'62'’ or ‘'x3E'’.  This method is only called if
     'convert_charrefs' is false.

 -- Metodo: HTMLParser.handle_comment (data)

     This method is called when a comment is encountered (e.g.
     ‘<!--comment-->’).

     For example, the comment ‘<!-- comment -->’ will cause this method
     to be called with the argument ‘' comment '’.

     The content of Internet Explorer conditional comments (condcoms)
     will also be sent to this method, so, for ‘<!--[if IE
     9]>IE9-specific content<![endif]-->’, this method will receive
     ‘'[if IE 9]>IE9-specific content<![endif]'’.

 -- Metodo: HTMLParser.handle_decl (decl)

     This method is called to handle an HTML doctype declaration (e.g.
     ‘<!DOCTYPE html>’).

     The 'decl' parameter will be the entire contents of the declaration
     inside the ‘<!...>’ markup (e.g.  ‘'DOCTYPE html'’).

 -- Metodo: HTMLParser.handle_pi (data)

     Method called when a processing instruction is encountered.  The
     'data' parameter will contain the entire processing instruction.
     For example, for the processing instruction ‘<?proc color='red'>’,
     this method would be called as ‘handle_pi("proc color='red'")’.  It
     is intended to be overridden by a derived class; the base class
     implementation does nothing.

          Nota: The *note HTMLParser: a79. class uses the SGML syntactic
          rules for processing instructions.  An XHTML processing
          instruction using the trailing ‘'?'’ will cause the ‘'?'’ to
          be included in 'data'.

 -- Metodo: HTMLParser.unknown_decl (data)

     This method is called when an unrecognized declaration is read by
     the parser.

     The 'data' parameter will be the entire contents of the declaration
     inside the ‘<![...]>’ markup.  It is sometimes useful to be
     overridden by a derived class.  The base class implementation does
     nothing.


File: python.info,  Node: Examples<25>,  Prev: HTMLParser Methods,  Up: html parser — Simple HTML and XHTML parser

5.21.2.3 Examples
.................

The following class implements a parser that will be used to illustrate
more examples:

     from html.parser import HTMLParser
     from html.entities import name2codepoint

     class MyHTMLParser(HTMLParser):
         def handle_starttag(self, tag, attrs):
             print("Start tag:", tag)
             for attr in attrs:
                 print("     attr:", attr)

         def handle_endtag(self, tag):
             print("End tag  :", tag)

         def handle_data(self, data):
             print("Data     :", data)

         def handle_comment(self, data):
             print("Comment  :", data)

         def handle_entityref(self, name):
             c = chr(name2codepoint[name])
             print("Named ent:", c)

         def handle_charref(self, name):
             if name.startswith('x'):
                 c = chr(int(name[1:], 16))
             else:
                 c = chr(int(name))
             print("Num ent  :", c)

         def handle_decl(self, data):
             print("Decl     :", data)

     parser = MyHTMLParser()

Parsing a doctype:

     >>> parser.feed('<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" '
     ...             '"http://www.w3.org/TR/html4/strict.dtd">')
     Decl     : DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"

Parsing an element with a few attributes and a title:

     >>> parser.feed('<img src="python-logo.png" alt="The Python logo">')
     Start tag: img
          attr: ('src', 'python-logo.png')
          attr: ('alt', 'The Python logo')
     >>>
     >>> parser.feed('<h1>Python</h1>')
     Start tag: h1
     Data     : Python
     End tag  : h1

The content of elements like ‘script’ and ‘style’ is returned as is,
without further parsing:

     >>> parser.feed('<style type="text/css">#python { color: green }</style>')
     Start tag: style
          attr: ('type', 'text/css')
     Data     : #python { color: green }
     End tag  : style

     >>> parser.feed('<script type="text/javascript">'
     ...             'alert("<strong>hello! &#9786;</strong>");</script>')
     Start tag: script
          attr: ('type', 'text/javascript')
     Data     : alert("<strong>hello! &#9786;</strong>");
     End tag  : script

Parsing comments:

     >>> parser.feed('<!--a comment-->'
     ...             '<!--[if IE 9]>IE-specific content<![endif]-->')
     Comment  : a comment
     Comment  : [if IE 9]>IE-specific content<![endif]

Parsing named and numeric character references and converting them to
the correct char (note: these 3 references are all equivalent to ‘'>'’):

     >>> parser = MyHTMLParser()
     >>> parser.feed('&gt;&#62;&#x3E;')
     Data     : >>>

     >>> parser = MyHTMLParser(convert_charrefs=False)
     >>> parser.feed('&gt;&#62;&#x3E;')
     Named ent: >
     Num ent  : >
     Num ent  : >

Feeding incomplete chunks to *note feed(): 3cb6. works, but *note
handle_data(): 3cbd. might be called more than once if
'convert_charrefs' is false:

     >>> for chunk in ['<sp', 'an>buff', 'ered', ' text</s', 'pan>']:
     ...     parser.feed(chunk)
     ...
     Start tag: span
     Data     : buff
     Data     : ered
     Data     :  text
     End tag  : span

Parsing invalid HTML (e.g.  unquoted attributes) also works:

     >>> parser.feed('<p><a class=link href=#main>tag soup</p ></a>')
     Start tag: p
     Start tag: a
          attr: ('class', 'link')
          attr: ('href', '#main')
     Data     : tag soup
     End tag  : p
     End tag  : a


File: python.info,  Node: html entities — Definitions of HTML general entities,  Next: XML Processing Modules,  Prev: html parser — Simple HTML and XHTML parser,  Up: Structured Markup Processing Tools

5.21.3 ‘html.entities’ — Definitions of HTML general entities
-------------------------------------------------------------

'Source code:' Lib/html/entities.py(1)

__________________________________________________________________

This module defines four dictionaries, *note html5: 12da, *note
name2codepoint: 3cc9, *note codepoint2name: 3cca, and *note entitydefs:
3ccb.

 -- Dati: html.entities.html5

     A dictionary that maps HTML5 named character references (2) to the
     equivalent Unicode character(s), e.g.  ‘html5['gt;'] == '>'’.  Note
     that the trailing semicolon is included in the name (e.g.
     ‘'gt;'’), however some of the names are accepted by the standard
     even without the semicolon: in this case the name is present with
     and without the ‘';'’.  See also *note html.unescape(): b52.

     Added in version 3.3.

 -- Dati: html.entities.entitydefs

     A dictionary mapping XHTML 1.0 entity definitions to their
     replacement text in ISO Latin-1.

 -- Dati: html.entities.name2codepoint

     A dictionary that maps HTML4 entity names to the Unicode code
     points.

 -- Dati: html.entities.codepoint2name

     A dictionary that maps Unicode code points to HTML4 entity names.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/html/entities.py

   (2) See
‘https://html.spec.whatwg.org/multipage/named-characters.html#named-character-references’


File: python.info,  Node: XML Processing Modules,  Next: xml etree ElementTree — The ElementTree XML API,  Prev: html entities — Definitions of HTML general entities,  Up: Structured Markup Processing Tools

5.21.4 XML Processing Modules
-----------------------------

'Source code:' Lib/xml/(1)

__________________________________________________________________

Python’s interfaces for processing XML are grouped in the ‘xml’ package.

     Nota: If you need to parse untrusted or unauthenticated data, see
     *note XML security: 3cd0.

It is important to note that modules in the *note xml: 126. package
require that there be at least one SAX-compliant XML parser available.
The Expat parser is included with Python, so the *note
xml.parsers.expat: 12c. module will always be available.

The documentation for the *note xml.dom: 127. and *note xml.sax: 12f.
packages are the definition of the Python bindings for the DOM and SAX
interfaces.

The XML handling submodules are:

   * *note xml.etree.ElementTree: 12b.: the ElementTree API, a simple
     and lightweight XML processor

   * *note xml.dom: 127.: the DOM API definition

   * *note xml.dom.minidom: 128.: a minimal DOM implementation

   * *note xml.dom.pulldom: 129.: support for building partial DOM trees

   * *note xml.sax: 12f.: SAX2 base classes and convenience functions

   * *note xml.parsers.expat: 12c.: the Expat parser binding
* Menu:

* XML security::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/xml/


File: python.info,  Node: XML security,  Up: XML Processing Modules

5.21.4.1 XML security
.....................

An attacker can abuse XML features to carry out denial of service
attacks, access local files, generate network connections to other
machines, or circumvent firewalls when attacker-controlled XML is being
parsed, in Python or elsewhere.

The built-in XML parsers of Python rely on the library libexpat(1),
commonly called Expat, for parsing XML.

By default, Expat itself does not access local files or create network
connections.

Expat versions lower than 2.7.2 may be vulnerable to the «billion
laughs», «quadratic blowup» and «large tokens» vulnerabilities, or to
disproportional use of dynamic memory.  Python bundles a copy of Expat,
and whether Python uses the bundled or a system-wide Expat, depends on
how the Python interpreter *note has been configured: 1b15. in your
environment.  Python may be vulnerable if it uses such older versions of
Expat.  Check ‘pyexpat.EXPAT_VERSION’.

*note xmlrpc: 133. is 'vulnerable' to the «decompression bomb» attack.

billion laughs / exponential entity expansion

     The Billion Laughs(2) attack – also known as exponential entity
     expansion – uses multiple levels of nested entities.  Each entity
     refers to another entity several times, and the final entity
     definition contains a small string.  The exponential expansion
     results in several gigabytes of text and consumes lots of memory
     and CPU time.

quadratic blowup entity expansion

     A quadratic blowup attack is similar to a Billion Laughs(3) attack;
     it abuses entity expansion, too.  Instead of nested entities it
     repeats one large entity with a couple of thousand chars over and
     over again.  The attack isn’t as efficient as the exponential case
     but it avoids triggering parser countermeasures that forbid deeply
     nested entities.

decompression bomb

     Decompression bombs (aka ZIP bomb(4)) apply to all XML libraries
     that can parse compressed XML streams such as gzipped HTTP streams
     or LZMA-compressed files.  For an attacker it can reduce the amount
     of transmitted data by three magnitudes or more.

large tokens

     Expat needs to re-parse unfinished tokens; without the protection
     introduced in Expat 2.6.0, this can lead to quadratic runtime that
     can be used to cause denial of service in the application parsing
     XML. The issue is known as CVE 2023-52425(5).

   ---------- Footnotes ----------

   (1) https://github.com/libexpat/libexpat

   (2) https://en.wikipedia.org/wiki/Billion_laughs

   (3) https://en.wikipedia.org/wiki/Billion_laughs

   (4) https://en.wikipedia.org/wiki/Zip_bomb

   (5) https://www.cve.org/CVERecord?id=CVE-2023-52425


File: python.info,  Node: xml etree ElementTree — The ElementTree XML API,  Next: xml dom — The Document Object Model API,  Prev: XML Processing Modules,  Up: Structured Markup Processing Tools

5.21.5 ‘xml.etree.ElementTree’ — The ElementTree XML API
--------------------------------------------------------

'Source code:' Lib/xml/etree/ElementTree.py(1)

__________________________________________________________________

The *note xml.etree.ElementTree: 12b. module implements a simple and
efficient API for parsing and creating XML data.

Cambiato nella versione 3.3: This module will use a fast implementation
whenever available.

Deprecato dalla versione 3.3: The ‘xml.etree.cElementTree’ module is
deprecated.

     Nota: If you need to parse untrusted or unauthenticated data, see
     *note XML security: 3cd0.

* Menu:

* Tutorial: Tutorial<3>.
* XPath support::
* Reference: Reference<5>.
* XInclude support::
* Reference: Reference<6>.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/xml/etree/ElementTree.py


File: python.info,  Node: Tutorial<3>,  Next: XPath support,  Up: xml etree ElementTree — The ElementTree XML API

5.21.5.1 Tutorial
.................

This is a short tutorial for using *note xml.etree.ElementTree: 12b.
(‘ET’ in short).  The goal is to demonstrate some of the building blocks
and basic concepts of the module.

* Menu:

* XML tree and elements::
* Parsing XML::
* Pull API for non-blocking parsing::
* Finding interesting elements::
* Modifying an XML File::
* Building XML documents::
* Parsing XML with Namespaces::


File: python.info,  Node: XML tree and elements,  Next: Parsing XML,  Up: Tutorial<3>

5.21.5.2 XML tree and elements
..............................

XML is an inherently hierarchical data format, and the most natural way
to represent it is with a tree.  ‘ET’ has two classes for this purpose -
*note ElementTree: b49. represents the whole XML document as a tree, and
*note Element: 363. represents a single node in this tree.  Interactions
with the whole document (reading and writing to/from files) are usually
done on the *note ElementTree: b49. level.  Interactions with a single
XML element and its sub-elements are done on the *note Element: 363.
level.


File: python.info,  Node: Parsing XML,  Next: Pull API for non-blocking parsing,  Prev: XML tree and elements,  Up: Tutorial<3>

5.21.5.3 Parsing XML
....................

We’ll be using the fictive ‘country_data.xml’ XML document as the sample
data for this section:

     <?xml version="1.0"?>
     <data>
         <country name="Liechtenstein">
             <rank>1</rank>
             <year>2008</year>
             <gdppc>141100</gdppc>
             <neighbor name="Austria" direction="E"/>
             <neighbor name="Switzerland" direction="W"/>
         </country>
         <country name="Singapore">
             <rank>4</rank>
             <year>2011</year>
             <gdppc>59900</gdppc>
             <neighbor name="Malaysia" direction="N"/>
         </country>
         <country name="Panama">
             <rank>68</rank>
             <year>2011</year>
             <gdppc>13600</gdppc>
             <neighbor name="Costa Rica" direction="W"/>
             <neighbor name="Colombia" direction="E"/>
         </country>
     </data>

We can import this data by reading from a file:

     import xml.etree.ElementTree as ET
     tree = ET.parse('country_data.xml')
     root = tree.getroot()

Or directly from a string:

     root = ET.fromstring(country_data_as_string)

*note fromstring(): 3cda. parses XML from a string directly into an
*note Element: 363, which is the root element of the parsed tree.  Other
parsing functions may create an *note ElementTree: b49.  Check the
documentation to be sure.

As an *note Element: 363, ‘root’ has a tag and a dictionary of
attributes:

     >>> root.tag
     'data'
     >>> root.attrib
     {}

It also has children nodes over which we can iterate:

     >>> for child in root:
     ...     print(child.tag, child.attrib)
     ...
     country {'name': 'Liechtenstein'}
     country {'name': 'Singapore'}
     country {'name': 'Panama'}

Children are nested, and we can access specific child nodes by index:

     >>> root[0][1].text
     '2008'

     Nota: Not all elements of the XML input will end up as elements of
     the parsed tree.  Currently, this module skips over any XML
     comments, processing instructions, and document type declarations
     in the input.  Nevertheless, trees built using this module’s API
     rather than parsing from XML text can have comments and processing
     instructions in them; they will be included when generating XML
     output.  A document type declaration may be accessed by passing a
     custom *note TreeBuilder: c4c. instance to the *note XMLParser:
     c4b. constructor.


File: python.info,  Node: Pull API for non-blocking parsing,  Next: Finding interesting elements,  Prev: Parsing XML,  Up: Tutorial<3>

5.21.5.4 Pull API for non-blocking parsing
..........................................

Most parsing functions provided by this module require the whole
document to be read at once before returning any result.  It is possible
to use an *note XMLParser: c4b. and feed data into it incrementally, but
it is a push API that calls methods on a callback target, which is too
low-level and inconvenient for most needs.  Sometimes what the user
really wants is to be able to parse XML incrementally, without blocking
operations, while enjoying the convenience of fully constructed *note
Element: 363. objects.

The most powerful tool for doing this is *note XMLPullParser: 11f5.  It
does not require a blocking read to obtain the XML data, and is instead
fed with data incrementally with *note XMLPullParser.feed(): 3cdc.
calls.  To get the parsed XML elements, call *note
XMLPullParser.read_events(): 3cdd.  Here is an example:

     >>> parser = ET.XMLPullParser(['start', 'end'])
     >>> parser.feed('<mytag>sometext')
     >>> list(parser.read_events())
     [('start', <Element 'mytag' at 0x7fa66db2be58>)]
     >>> parser.feed(' more text</mytag>')
     >>> for event, elem in parser.read_events():
     ...     print(event)
     ...     print(elem.tag, 'text=', elem.text)
     ...
     end
     mytag text= sometext more text

The obvious use case is applications that operate in a non-blocking
fashion where the XML data is being received from a socket or read
incrementally from some storage device.  In such cases, blocking reads
are unacceptable.

Because it’s so flexible, *note XMLPullParser: 11f5. can be inconvenient
to use for simpler use-cases.  If you don’t mind your application
blocking on reading XML data but would still like to have incremental
parsing capabilities, take a look at *note iterparse(): 57a.  It can be
useful when you’re reading a large XML document and don’t want to hold
it wholly in memory.

Where 'immediate' feedback through events is wanted, calling method
*note XMLPullParser.flush(): 577. can help reduce delay; please make
sure to study the related security notes.


File: python.info,  Node: Finding interesting elements,  Next: Modifying an XML File,  Prev: Pull API for non-blocking parsing,  Up: Tutorial<3>

5.21.5.5 Finding interesting elements
.....................................

*note Element: 363. has some useful methods that help iterate
recursively over all the sub-tree below it (its children, their
children, and so on).  For example, *note Element.iter(): 1556.:

     >>> for neighbor in root.iter('neighbor'):
     ...     print(neighbor.attrib)
     ...
     {'name': 'Austria', 'direction': 'E'}
     {'name': 'Switzerland', 'direction': 'W'}
     {'name': 'Malaysia', 'direction': 'N'}
     {'name': 'Costa Rica', 'direction': 'W'}
     {'name': 'Colombia', 'direction': 'E'}

*note Element.findall(): 1864. finds only elements with a tag which are
direct children of the current element.  *note Element.find(): 1862.
finds the 'first' child with a particular tag, and *note Element.text:
3cdf. accesses the element’s text content.  *note Element.get(): 3ce0.
accesses the element’s attributes:

     >>> for country in root.findall('country'):
     ...     rank = country.find('rank').text
     ...     name = country.get('name')
     ...     print(name, rank)
     ...
     Liechtenstein 1
     Singapore 4
     Panama 68

More sophisticated specification of which elements to look for is
possible by using *note XPath: da8.


File: python.info,  Node: Modifying an XML File,  Next: Building XML documents,  Prev: Finding interesting elements,  Up: Tutorial<3>

5.21.5.6 Modifying an XML File
..............................

*note ElementTree: b49. provides a simple way to build XML documents and
write them to files.  The *note ElementTree.write(): c8e. method serves
this purpose.

Once created, an *note Element: 363. object may be manipulated by
directly changing its fields (such as *note Element.text: 3cdf.), adding
and modifying attributes (*note Element.set(): 3ce2. method), as well as
adding new children (for example with *note Element.append(): 3ce3.).

Let’s say we want to add one to each country’s rank, and add an
‘updated’ attribute to the rank element:

     >>> for rank in root.iter('rank'):
     ...     new_rank = int(rank.text) + 1
     ...     rank.text = str(new_rank)
     ...     rank.set('updated', 'yes')
     ...
     >>> tree.write('output.xml')

Our XML now looks like this:

     <?xml version="1.0"?>
     <data>
         <country name="Liechtenstein">
             <rank updated="yes">2</rank>
             <year>2008</year>
             <gdppc>141100</gdppc>
             <neighbor name="Austria" direction="E"/>
             <neighbor name="Switzerland" direction="W"/>
         </country>
         <country name="Singapore">
             <rank updated="yes">5</rank>
             <year>2011</year>
             <gdppc>59900</gdppc>
             <neighbor name="Malaysia" direction="N"/>
         </country>
         <country name="Panama">
             <rank updated="yes">69</rank>
             <year>2011</year>
             <gdppc>13600</gdppc>
             <neighbor name="Costa Rica" direction="W"/>
             <neighbor name="Colombia" direction="E"/>
         </country>
     </data>

We can remove elements using *note Element.remove(): 185e.  Let’s say we
want to remove all countries with a rank higher than 50:

     >>> for country in root.findall('country'):
     ...     # using root.findall() to avoid removal during traversal
     ...     rank = int(country.find('rank').text)
     ...     if rank > 50:
     ...         root.remove(country)
     ...
     >>> tree.write('output.xml')

Note that concurrent modification while iterating can lead to problems,
just like when iterating and modifying Python lists or dicts.
Therefore, the example first collects all matching elements with
‘root.findall()’, and only then iterates over the list of matches.

Our XML now looks like this:

     <?xml version="1.0"?>
     <data>
         <country name="Liechtenstein">
             <rank updated="yes">2</rank>
             <year>2008</year>
             <gdppc>141100</gdppc>
             <neighbor name="Austria" direction="E"/>
             <neighbor name="Switzerland" direction="W"/>
         </country>
         <country name="Singapore">
             <rank updated="yes">5</rank>
             <year>2011</year>
             <gdppc>59900</gdppc>
             <neighbor name="Malaysia" direction="N"/>
         </country>
     </data>


File: python.info,  Node: Building XML documents,  Next: Parsing XML with Namespaces,  Prev: Modifying an XML File,  Up: Tutorial<3>

5.21.5.7 Building XML documents
...............................

The *note SubElement(): 3ce5. function also provides a convenient way to
create new sub-elements for a given element:

     >>> a = ET.Element('a')
     >>> b = ET.SubElement(a, 'b')
     >>> c = ET.SubElement(a, 'c')
     >>> d = ET.SubElement(c, 'd')
     >>> ET.dump(a)
     <a><b /><c><d /></c></a>


File: python.info,  Node: Parsing XML with Namespaces,  Prev: Building XML documents,  Up: Tutorial<3>

5.21.5.8 Parsing XML with Namespaces
....................................

If the XML input has namespaces(1), tags and attributes with prefixes in
the form ‘prefix:sometag’ get expanded to ‘{uri}sometag’ where the
'prefix' is replaced by the full 'URI'. Also, if there is a default
namespace(2), that full URI gets prepended to all of the non-prefixed
tags.

Here is an XML example that incorporates two namespaces, one with the
prefix «fictional» and the other serving as the default namespace:

     <?xml version="1.0"?>
     <actors xmlns:fictional="http://characters.example.com"
             xmlns="http://people.example.com">
         <actor>
             <name>John Cleese</name>
             <fictional:character>Lancelot</fictional:character>
             <fictional:character>Archie Leach</fictional:character>
         </actor>
         <actor>
             <name>Eric Idle</name>
             <fictional:character>Sir Robin</fictional:character>
             <fictional:character>Gunther</fictional:character>
             <fictional:character>Commander Clement</fictional:character>
         </actor>
     </actors>

One way to search and explore this XML example is to manually add the
URI to every tag or attribute in the xpath of a *note find(): 1862. or
*note findall(): 1864.:

     root = fromstring(xml_text)
     for actor in root.findall('{http://people.example.com}actor'):
         name = actor.find('{http://people.example.com}name')
         print(name.text)
         for char in actor.findall('{http://characters.example.com}character'):
             print(' |-->', char.text)

A better way to search the namespaced XML example is to create a
dictionary with your own prefixes and use those in the search functions:

     ns = {'real_person': 'http://people.example.com',
           'role': 'http://characters.example.com'}

     for actor in root.findall('real_person:actor', ns):
         name = actor.find('real_person:name', ns)
         print(name.text)
         for char in actor.findall('role:character', ns):
             print(' |-->', char.text)

These two approaches both output:

     John Cleese
      |--> Lancelot
      |--> Archie Leach
     Eric Idle
      |--> Sir Robin
      |--> Gunther
      |--> Commander Clement

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/XML_namespace

   (2) https://www.w3.org/TR/xml-names/#defaulting


File: python.info,  Node: XPath support,  Next: Reference<5>,  Prev: Tutorial<3>,  Up: xml etree ElementTree — The ElementTree XML API

5.21.5.9 XPath support
......................

This module provides limited support for XPath expressions(1) for
locating elements in a tree.  The goal is to support a small subset of
the abbreviated syntax; a full XPath engine is outside the scope of the
module.

* Menu:

* Example: Example<8>.
* Supported XPath syntax::

   ---------- Footnotes ----------

   (1) https://www.w3.org/TR/xpath


File: python.info,  Node: Example<8>,  Next: Supported XPath syntax,  Up: XPath support

5.21.5.10 Example
.................

Here’s an example that demonstrates some of the XPath capabilities of
the module.  We’ll be using the ‘countrydata’ XML document from the
*note Parsing XML: 3cd8. section:

     import xml.etree.ElementTree as ET

     root = ET.fromstring(countrydata)

     # Top-level elements
     root.findall(".")

     # All 'neighbor' grand-children of 'country' children of the top-level
     # elements
     root.findall("./country/neighbor")

     # Nodes with name='Singapore' that have a 'year' child
     root.findall(".//year/..[@name='Singapore']")

     # 'year' nodes that are children of nodes with name='Singapore'
     root.findall(".//*[@name='Singapore']/year")

     # All 'neighbor' nodes that are the second child of their parent
     root.findall(".//neighbor[2]")

For XML with namespaces, use the usual qualified ‘{namespace}tag’
notation:

     # All dublin-core "title" tags in the document
     root.findall(".//{http://purl.org/dc/elements/1.1/}title")


File: python.info,  Node: Supported XPath syntax,  Prev: Example<8>,  Up: XPath support

5.21.5.11 Supported XPath syntax
................................

Syntax                      Meaning
                            
---------------------------------------------------------------------------------------
                            
‘tag’                       Selects all child elements with the given tag.  For
                            example, ‘spam’ selects all child elements named ‘spam’,
                            and ‘spam/egg’ selects all grandchildren named ‘egg’ in
                            all children named ‘spam’.  ‘{namespace}*’ selects all
                            tags in the given namespace, ‘{*}spam’ selects tags
                            named ‘spam’ in any (or no) namespace, and ‘{}*’ only
                            selects tags that are not in a namespace.
                            
                            Cambiato nella versione 3.8: Support for star-wildcards
                            was added.
                            
                            
‘*’                         Selects all child elements, including comments and
                            processing instructions.  For example, ‘*/egg’ selects
                            all grandchildren named ‘egg’.
                            
                            
‘.’                         Selects the current node.  This is mostly useful at the
                            beginning of the path, to indicate that it’s a relative
                            path.
                            
                            
‘//’                        Selects all subelements, on all levels beneath the
                            current element.  For example, ‘.//egg’ selects all
                            ‘egg’ elements in the entire tree.
                            
                            
‘..’                        Selects the parent element.  Returns ‘None’ if the path
                            attempts to reach the ancestors of the start element
                            (the element ‘find’ was called on).
                            
                            
‘[@attrib]’                 Selects all elements that have the given attribute.
                            
                            
‘[@attrib='value']’         Selects all elements for which the given attribute has
                            the given value.  The value cannot contain quotes.
                            
                            
‘[@attrib!='value']’        Selects all elements for which the given attribute does
                            not have the given value.  The value cannot contain
                            quotes.
                            
                            Added in version 3.10.
                            
                            
‘[tag]’                     Selects all elements that have a child named ‘tag’.
                            Only immediate children are supported.
                            
                            
‘[.='text']’                Selects all elements whose complete text content,
                            including descendants, equals the given ‘text’.
                            
                            Added in version 3.7.
                            
                            
‘[.!='text']’               Selects all elements whose complete text content,
                            including descendants, does not equal the given ‘text’.
                            
                            Added in version 3.10.
                            
                            
‘[tag='text']’              Selects all elements that have a child named ‘tag’ whose
                            complete text content, including descendants, equals the
                            given ‘text’.
                            
                            
‘[tag!='text']’             Selects all elements that have a child named ‘tag’ whose
                            complete text content, including descendants, does not
                            equal the given ‘text’.
                            
                            Added in version 3.10.
                            
                            
‘[position]’                Selects all elements that are located at the given
                            position.  The position can be either an integer (1 is
                            the first position), the expression ‘last()’ (for the
                            last position), or a position relative to the last
                            position (e.g.  ‘last()-1’).
                            

Predicates (expressions within square brackets) must be preceded by a
tag name, an asterisk, or another predicate.  ‘position’ predicates must
be preceded by a tag name.


File: python.info,  Node: Reference<5>,  Next: XInclude support,  Prev: XPath support,  Up: xml etree ElementTree — The ElementTree XML API

5.21.5.12 Reference
...................

* Menu:

* Functions: Functions<8>.


File: python.info,  Node: Functions<8>,  Up: Reference<5>

5.21.5.13 Functions
...................

 -- Funzione: xml.etree.ElementTree.canonicalize (xml_data=None, *,
          out=None, from_file=None, **options)

     C14N 2.0(1) transformation function.

     Canonicalization is a way to normalise XML output in a way that
     allows byte-by-byte comparisons and digital signatures.  It reduces
     the freedom that XML serializers have and instead generates a more
     constrained XML representation.  The main restrictions regard the
     placement of namespace declarations, the ordering of attributes,
     and ignorable whitespace.

     This function takes an XML data string ('xml_data') or a file path
     or file-like object ('from_file') as input, converts it to the
     canonical form, and writes it out using the 'out' file(-like)
     object, if provided, or returns it as a text string if not.  The
     output file receives text, not bytes.  It should therefore be
     opened in text mode with ‘utf-8’ encoding.

     Typical uses:

          xml_data = "<root>...</root>"
          print(canonicalize(xml_data))

          with open("c14n_output.xml", mode='w', encoding='utf-8') as out_file:
              canonicalize(xml_data, out=out_file)

          with open("c14n_output.xml", mode='w', encoding='utf-8') as out_file:
              canonicalize(from_file="inputfile.xml", out=out_file)

     The configuration 'options' are as follows:

        - 'with_comments': set to true to include comments (default:
          false)

        - 
          'strip_text': set to true to strip whitespace before and after text content

               (default: false)

        - 
          'rewrite_prefixes': set to true to replace namespace prefixes by «n{number}»

               (default: false)

        - 
          'qname_aware_tags': a set of qname aware tag names in which prefixes

               should be replaced in text content (default: empty)

        - 
          'qname_aware_attrs': a set of qname aware attribute names in which prefixes

               should be replaced in text content (default: empty)

        - 'exclude_attrs': a set of attribute names that should not be
          serialised

        - 'exclude_tags': a set of tag names that should not be
          serialised

     In the option list above, «a set» refers to any collection or
     iterable of strings, no ordering is expected.

     Added in version 3.8.

 -- Funzione: xml.etree.ElementTree.Comment (text=None)

     Comment element factory.  This factory function creates a special
     element that will be serialized as an XML comment by the standard
     serializer.  The comment string can be either a bytestring or a
     Unicode string.  'text' is a string containing the comment string.
     Returns an element instance representing a comment.

     Note that *note XMLParser: c4b. skips over comments in the input
     instead of creating comment objects for them.  An *note
     ElementTree: b49. will only contain comment nodes if they have been
     inserted into to the tree using one of the *note Element: 363.
     methods.

 -- Funzione: xml.etree.ElementTree.dump (elem)

     Writes an element tree or element structure to sys.stdout.  This
     function should be used for debugging only.

     The exact output format is implementation dependent.  In this
     version, it’s written as an ordinary XML file.

     'elem' is an element tree or an individual element.

     Cambiato nella versione 3.8: The *note dump(): 3cee. function now
     preserves the attribute order specified by the user.

 -- Funzione: xml.etree.ElementTree.fromstring (text, parser=None)

     Parses an XML section from a string constant.  Same as *note XML():
     3cef.  'text' is a string containing XML data.  'parser' is an
     optional parser instance.  If not given, the standard *note
     XMLParser: c4b. parser is used.  Returns an *note Element: 363.
     instance.

 -- Funzione: xml.etree.ElementTree.fromstringlist (sequence,
          parser=None)

     Parses an XML document from a sequence of string fragments.
     'sequence' is a list or other sequence containing XML data
     fragments.  'parser' is an optional parser instance.  If not given,
     the standard *note XMLParser: c4b. parser is used.  Returns an
     *note Element: 363. instance.

     Added in version 3.2.

 -- Funzione: xml.etree.ElementTree.indent (tree, space=' ', level=0)

     Appends whitespace to the subtree to indent the tree visually.
     This can be used to generate pretty-printed XML output.  'tree' can
     be an Element or ElementTree.  'space' is the whitespace string
     that will be inserted for each indentation level, two space
     characters by default.  For indenting partial subtrees inside of an
     already indented tree, pass the initial indentation level as
     'level'.

     Added in version 3.9.

 -- Funzione: xml.etree.ElementTree.iselement (element)

     Check if an object appears to be a valid element object.  'element'
     is an element instance.  Return ‘True’ if this is an element
     object.

 -- Funzione: xml.etree.ElementTree.iterparse (source, events=None,
          parser=None)

     Parses an XML section into an element tree incrementally, and
     reports what’s going on to the user.  'source' is a filename or
     *note file object: 13cb. containing XML data.  'events' is a
     sequence of events to report back.  The supported events are the
     strings ‘"start"’, ‘"end"’, ‘"comment"’, ‘"pi"’, ‘"start-ns"’ and
     ‘"end-ns"’ (the «ns» events are used to get detailed namespace
     information).  If 'events' is omitted, only ‘"end"’ events are
     reported.  'parser' is an optional parser instance.  If not given,
     the standard *note XMLParser: c4b. parser is used.  'parser' must
     be a subclass of *note XMLParser: c4b. and can only use the default
     *note TreeBuilder: c4c. as a target.  Returns an *note iterator:
     4c9. providing ‘(event, elem)’ pairs; it has a ‘root’ attribute
     that references the root element of the resulting XML tree once
     'source' is fully read.  The iterator has the ‘close()’ method that
     closes the internal file object if 'source' is a filename.

     Note that while *note iterparse(): 57a. builds the tree
     incrementally, it issues blocking reads on 'source' (or the file it
     names).  As such, it’s unsuitable for applications where blocking
     reads can’t be made.  For fully non-blocking parsing, see *note
     XMLPullParser: 11f5.

          Nota: *note iterparse(): 57a. only guarantees that it has seen
          the «>» character of a starting tag when it emits a «start»
          event, so the attributes are defined, but the contents of the
          text and tail attributes are undefined at that point.  The
          same applies to the element children; they may or may not be
          present.

          If you need a fully populated element, look for «end» events
          instead.

     Deprecato dalla versione 3.4: The 'parser' argument.

     Cambiato nella versione 3.8: The ‘comment’ and ‘pi’ events were
     added.

     Cambiato nella versione 3.13: Added the ‘close()’ method.

 -- Funzione: xml.etree.ElementTree.parse (source, parser=None)

     Parses an XML section into an element tree.  'source' is a filename
     or file object containing XML data.  'parser' is an optional parser
     instance.  If not given, the standard *note XMLParser: c4b. parser
     is used.  Returns an *note ElementTree: b49. instance.

 -- Funzione: xml.etree.ElementTree.ProcessingInstruction (target,
          text=None)

     PI element factory.  This factory function creates a special
     element that will be serialized as an XML processing instruction.
     'target' is a string containing the PI target.  'text' is a string
     containing the PI contents, if given.  Returns an element instance,
     representing a processing instruction.

     Note that *note XMLParser: c4b. skips over processing instructions
     in the input instead of creating PI objects for them.  An *note
     ElementTree: b49. will only contain processing instruction nodes if
     they have been inserted into to the tree using one of the *note
     Element: 363. methods.

 -- Funzione: xml.etree.ElementTree.register_namespace (prefix, uri)

     Registers a namespace prefix.  The registry is global, and any
     existing mapping for either the given prefix or the namespace URI
     will be removed.  'prefix' is a namespace prefix.  'uri' is a
     namespace uri.  Tags and attributes in this namespace will be
     serialized with the given prefix, if at all possible.

     Added in version 3.2.

 -- Funzione: xml.etree.ElementTree.SubElement (parent, tag, attrib={},
          **extra)

     Subelement factory.  This function creates an element instance, and
     appends it to an existing element.

     The element name, attribute names, and attribute values can be
     either bytestrings or Unicode strings.  'parent' is the parent
     element.  'tag' is the subelement name.  'attrib' is an optional
     dictionary, containing element attributes.  'extra' contains
     additional attributes, given as keyword arguments.  Returns an
     element instance.

 -- Funzione: xml.etree.ElementTree.tostring (element,
          encoding='us-ascii', method='xml', *, xml_declaration=None,
          default_namespace=None, short_empty_elements=True)

     Generates a string representation of an XML element, including all
     subelements.  'element' is an *note Element: 363. instance.
     'encoding' (2) is the output encoding (default is US-ASCII). Use
     ‘encoding="unicode"’ to generate a Unicode string (otherwise, a
     bytestring is generated).  'method' is either ‘"xml"’, ‘"html"’ or
     ‘"text"’ (default is ‘"xml"’).  'xml_declaration',
     'default_namespace' and 'short_empty_elements' has the same meaning
     as in *note ElementTree.write(): c8e.  Returns an (optionally)
     encoded string containing the XML data.

     Cambiato nella versione 3.4: Added the 'short_empty_elements'
     parameter.

     Cambiato nella versione 3.8: Added the 'xml_declaration' and
     'default_namespace' parameters.

     Cambiato nella versione 3.8: The *note tostring(): 11f7. function
     now preserves the attribute order specified by the user.

 -- Funzione: xml.etree.ElementTree.tostringlist (element,
          encoding='us-ascii', method='xml', *, xml_declaration=None,
          default_namespace=None, short_empty_elements=True)

     Generates a string representation of an XML element, including all
     subelements.  'element' is an *note Element: 363. instance.
     'encoding' (3) is the output encoding (default is US-ASCII). Use
     ‘encoding="unicode"’ to generate a Unicode string (otherwise, a
     bytestring is generated).  'method' is either ‘"xml"’, ‘"html"’ or
     ‘"text"’ (default is ‘"xml"’).  'xml_declaration',
     'default_namespace' and 'short_empty_elements' has the same meaning
     as in *note ElementTree.write(): c8e.  Returns a list of
     (optionally) encoded strings containing the XML data.  It does not
     guarantee any specific sequence, except that
     ‘b"".join(tostringlist(element)) == tostring(element)’.

     Added in version 3.2.

     Cambiato nella versione 3.4: Added the 'short_empty_elements'
     parameter.

     Cambiato nella versione 3.8: Added the 'xml_declaration' and
     'default_namespace' parameters.

     Cambiato nella versione 3.8: The *note tostringlist(): 11f8.
     function now preserves the attribute order specified by the user.

 -- Funzione: xml.etree.ElementTree.XML (text, parser=None)

     Parses an XML section from a string constant.  This function can be
     used to embed «XML literals» in Python code.  'text' is a string
     containing XML data.  'parser' is an optional parser instance.  If
     not given, the standard *note XMLParser: c4b. parser is used.
     Returns an *note Element: 363. instance.

 -- Funzione: xml.etree.ElementTree.XMLID (text, parser=None)

     Parses an XML section from a string constant, and also returns a
     dictionary which maps from element id:s to elements.  'text' is a
     string containing XML data.  'parser' is an optional parser
     instance.  If not given, the standard *note XMLParser: c4b. parser
     is used.  Returns a tuple containing an *note Element: 363.
     instance and a dictionary.

   ---------- Footnotes ----------

   (1) https://www.w3.org/TR/xml-c14n2/

   (2) The encoding string included in XML output should conform to the
appropriate standards.  For example, «UTF-8» is valid, but «UTF8» is
not.  See
‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and
‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’.

   (3) The encoding string included in XML output should conform to the
appropriate standards.  For example, «UTF-8» is valid, but «UTF8» is
not.  See
‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and
‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’.


File: python.info,  Node: XInclude support,  Next: Reference<6>,  Prev: Reference<5>,  Up: xml etree ElementTree — The ElementTree XML API

5.21.5.14 XInclude support
..........................

This module provides limited support for XInclude directives(1), via the
*note xml.etree.ElementInclude: 12a. helper module.  This module can be
used to insert subtrees and text strings into element trees, based on
information in the tree.

* Menu:

* Example: Example<9>.

   ---------- Footnotes ----------

   (1) https://www.w3.org/TR/xinclude/


File: python.info,  Node: Example<9>,  Up: XInclude support

5.21.5.15 Example
.................

Here’s an example that demonstrates use of the XInclude module.  To
include an XML document in the current document, use the
‘{http://www.w3.org/2001/XInclude}include’ element and set the 'parse'
attribute to ‘"xml"’, and use the 'href' attribute to specify the
document to include.

     <?xml version="1.0"?>
     <document xmlns:xi="http://www.w3.org/2001/XInclude">
       <xi:include href="source.xml" parse="xml" />
     </document>

By default, the 'href' attribute is treated as a file name.  You can use
custom loaders to override this behaviour.  Also note that the standard
helper does not support XPointer syntax.

To process this file, load it as usual, and pass the root element to the
*note xml.etree.ElementTree: 12b. module:

     from xml.etree import ElementTree, ElementInclude

     tree = ElementTree.parse("document.xml")
     root = tree.getroot()

     ElementInclude.include(root)

The ElementInclude module replaces the
‘{http://www.w3.org/2001/XInclude}include’ element with the root element
from the 'source.xml' document.  The result might look something like
this:

     <document xmlns:xi="http://www.w3.org/2001/XInclude">
       <para>This is a paragraph.</para>
     </document>

If the 'parse' attribute is omitted, it defaults to «xml».  The href
attribute is required.

To include a text document, use the
‘{http://www.w3.org/2001/XInclude}include’ element, and set the 'parse'
attribute to «text»:

     <?xml version="1.0"?>
     <document xmlns:xi="http://www.w3.org/2001/XInclude">
       Copyright (c) <xi:include href="year.txt" parse="text" />.
     </document>

The result might look something like:

     <document xmlns:xi="http://www.w3.org/2001/XInclude">
       Copyright (c) 2003.
     </document>


File: python.info,  Node: Reference<6>,  Prev: XInclude support,  Up: xml etree ElementTree — The ElementTree XML API

5.21.5.16 Reference
...................

* Menu:

* Functions: Functions<9>.
* Element Objects::
* ElementTree Objects::
* QName Objects::
* TreeBuilder Objects::
* XMLParser Objects::
* XMLPullParser Objects::
* Exceptions: Exceptions<21>.


File: python.info,  Node: Functions<9>,  Next: Element Objects,  Up: Reference<6>

5.21.5.17 Functions
...................

 -- Funzione: xml.etree.ElementInclude.default_loader (href, parse,
          encoding=None)

     Default loader.  This default loader reads an included resource
     from disk.  'href' is a URL. 'parse' is for parse mode either «xml»
     or «text».  'encoding' is an optional text encoding.  If not given,
     encoding is ‘utf-8’.  Returns the expanded resource.  If the parse
     mode is ‘"xml"’, this is an *note Element: 363. instance.  If the
     parse mode is ‘"text"’, this is a string.  If the loader fails, it
     can return ‘None’ or raise an exception.

 -- Funzione: xml.etree.ElementInclude.include (elem, loader=None,
          base_url=None, max_depth=6)

     This function expands XInclude directives in-place in tree pointed
     by 'elem'.  'elem' is either the root *note Element: 363. or an
     *note ElementTree: b49. instance to find such element.  'loader' is
     an optional resource loader.  If omitted, it defaults to *note
     default_loader(): 3cfb.  If given, it should be a callable that
     implements the same interface as *note default_loader(): 3cfb.
     'base_url' is base URL of the original file, to resolve relative
     include file references.  'max_depth' is the maximum number of
     recursive inclusions.  Limited to reduce the risk of malicious
     content explosion.  Pass ‘None’ to disable the limitation.

     Cambiato nella versione 3.9: Added the 'base_url' and 'max_depth'
     parameters.


File: python.info,  Node: Element Objects,  Next: ElementTree Objects,  Prev: Functions<9>,  Up: Reference<6>

5.21.5.18 Element Objects
.........................

 -- Classe: xml.etree.ElementTree.Element (tag, attrib={}, **extra)

     Element class.  This class defines the Element interface, and
     provides a reference implementation of this interface.

     The element name, attribute names, and attribute values can be
     either bytestrings or Unicode strings.  'tag' is the element name.
     'attrib' is an optional dictionary, containing element attributes.
     'extra' contains additional attributes, given as keyword arguments.

      -- Attributo: tag

          A string identifying what kind of data this element represents
          (the element type, in other words).

      -- Attributo: text
      -- Attributo: tail

          These attributes can be used to hold additional data
          associated with the element.  Their values are usually strings
          but may be any application-specific object.  If the element is
          created from an XML file, the 'text' attribute holds either
          the text between the element’s start tag and its first child
          or end tag, or ‘None’, and the 'tail' attribute holds either
          the text between the element’s end tag and the next tag, or
          ‘None’.  For the XML data

               <a><b>1<c>2<d/>3</c></b>4</a>

          the 'a' element has ‘None’ for both 'text' and 'tail'
          attributes, the 'b' element has 'text' ‘"1"’ and 'tail' ‘"4"’,
          the 'c' element has 'text' ‘"2"’ and 'tail' ‘None’, and the
          'd' element has 'text' ‘None’ and 'tail' ‘"3"’.

          To collect the inner text of an element, see *note itertext():
          13dd, for example ‘"".join(element.itertext())’.

          Applications may store arbitrary objects in these attributes.

      -- Attributo: attrib

          A dictionary containing the element’s attributes.  Note that
          while the 'attrib' value is always a real mutable Python
          dictionary, an ElementTree implementation may choose to use
          another internal representation, and create the dictionary
          only if someone asks for it.  To take advantage of such
          implementations, use the dictionary methods below whenever
          possible.

     The following dictionary-like methods work on the element
     attributes.

      -- Metodo: clear ()

          Resets an element.  This function removes all subelements,
          clears all attributes, and sets the text and tail attributes
          to ‘None’.

      -- Metodo: get (key, default=None)

          Gets the element attribute named 'key'.

          Returns the attribute value, or 'default' if the attribute was
          not found.

      -- Metodo: items ()

          Returns the element attributes as a sequence of (name, value)
          pairs.  The attributes are returned in an arbitrary order.

      -- Metodo: keys ()

          Returns the elements attribute names as a list.  The names are
          returned in an arbitrary order.

      -- Metodo: set (key, value)

          Set the attribute 'key' on the element to 'value'.

     The following methods work on the element’s children (subelements).

      -- Metodo: append (subelement)

          Adds the element 'subelement' to the end of this element’s
          internal list of subelements.  Raises *note TypeError: 198. if
          'subelement' is not an *note Element: 363.

      -- Metodo: extend (subelements)

          Appends 'subelements' from an iterable of elements.  Raises
          *note TypeError: 198. if a subelement is not an *note Element:
          363.

          Added in version 3.2.

      -- Metodo: find (match, namespaces=None)

          Finds the first subelement matching 'match'.  'match' may be a
          tag name or a *note path: da8.  Returns an element instance or
          ‘None’.  'namespaces' is an optional mapping from namespace
          prefix to full name.  Pass ‘''’ as prefix to move all
          unprefixed tag names in the expression into the given
          namespace.

      -- Metodo: findall (match, namespaces=None)

          Finds all matching subelements, by tag name or *note path:
          da8.  Returns a list containing all matching elements in
          document order.  'namespaces' is an optional mapping from
          namespace prefix to full name.  Pass ‘''’ as prefix to move
          all unprefixed tag names in the expression into the given
          namespace.

      -- Metodo: findtext (match, default=None, namespaces=None)

          Finds text for the first subelement matching 'match'.  'match'
          may be a tag name or a *note path: da8.  Returns the text
          content of the first matching element, or 'default' if no
          element was found.  Note that if the matching element has no
          text content an empty string is returned.  'namespaces' is an
          optional mapping from namespace prefix to full name.  Pass
          ‘''’ as prefix to move all unprefixed tag names in the
          expression into the given namespace.

      -- Metodo: insert (index, subelement)

          Inserts 'subelement' at the given position in this element.
          Raises *note TypeError: 198. if 'subelement' is not an *note
          Element: 363.

      -- Metodo: iter (tag=None)

          Creates a tree *note iterator: 4c9. with the current element
          as the root.  The iterator iterates over this element and all
          elements below it, in document (depth first) order.  If 'tag'
          is not ‘None’ or ‘'*'’, only elements whose tag equals 'tag'
          are returned from the iterator.  If the tree structure is
          modified during iteration, the result is undefined.

          Added in version 3.2.

      -- Metodo: iterfind (match, namespaces=None)

          Finds all matching subelements, by tag name or *note path:
          da8.  Returns an iterable yielding all matching elements in
          document order.  'namespaces' is an optional mapping from
          namespace prefix to full name.

          Added in version 3.2.

      -- Metodo: itertext ()

          Creates a text iterator.  The iterator loops over this element
          and all subelements, in document order, and returns all inner
          text.

          Added in version 3.2.

      -- Metodo: makeelement (tag, attrib)

          Creates a new element object of the same type as this element.
          Do not call this method, use the *note SubElement(): 3ce5.
          factory function instead.

      -- Metodo: remove (subelement)

          Removes 'subelement' from the element.  Unlike the find*
          methods this method compares elements based on the instance
          identity, not on tag value or contents.

     *note Element: 363. objects also support the following sequence
     type methods for working with subelements: *note __delitem__():
     14d4, *note __getitem__(): 588, *note __setitem__(): 14d3, *note
     __len__(): 1777.

     Caution: Elements with no subelements will test as ‘False’.  In a
     future release of Python, all elements will test as ‘True’
     regardless of whether subelements exist.  Instead, prefer explicit
     ‘len(elem)’ or ‘elem is not None’ tests.:

          element = root.find('foo')

          if not element:  # careful!
              print("element not found, or element has no subelements")

          if element is None:
              print("element not found")

     Cambiato nella versione 3.12: Testing the truth value of an Element
     emits *note DeprecationWarning: 1a3.

     Prior to Python 3.8, the serialisation order of the XML attributes
     of elements was artificially made predictable by sorting the
     attributes by their name.  Based on the now guaranteed ordering of
     dicts, this arbitrary reordering was removed in Python 3.8 to
     preserve the order in which attributes were originally parsed or
     created by user code.

     In general, user code should try not to depend on a specific
     ordering of attributes, given that the XML Information Set(1)
     explicitly excludes the attribute order from conveying information.
     Code should be prepared to deal with any ordering on input.  In
     cases where deterministic XML output is required, e.g.  for
     cryptographic signing or test data sets, canonical serialisation is
     available with the *note canonicalize(): c4a. function.

     In cases where canonical output is not applicable but a specific
     attribute order is still desirable on output, code should aim for
     creating the attributes directly in the desired order, to avoid
     perceptual mismatches for readers of the code.  In cases where this
     is difficult to achieve, a recipe like the following can be applied
     prior to serialisation to enforce an order independently from the
     Element creation:

          def reorder_attributes(root):
              for el in root.iter():
                  attrib = el.attrib
                  if len(attrib) > 1:
                      # adjust attribute order, e.g. by sorting
                      attribs = sorted(attrib.items())
                      attrib.clear()
                      attrib.update(attribs)

   ---------- Footnotes ----------

   (1) https://www.w3.org/TR/xml-infoset/


File: python.info,  Node: ElementTree Objects,  Next: QName Objects,  Prev: Element Objects,  Up: Reference<6>

5.21.5.19 ElementTree Objects
.............................

 -- Classe: xml.etree.ElementTree.ElementTree (element=None, file=None)

     ElementTree wrapper class.  This class represents an entire element
     hierarchy, and adds some extra support for serialization to and
     from standard XML.

     'element' is the root element.  The tree is initialized with the
     contents of the XML 'file' if given.

      -- Metodo: _setroot (element)

          Replaces the root element for this tree.  This discards the
          current contents of the tree, and replaces it with the given
          element.  Use with care.  'element' is an element instance.

      -- Metodo: find (match, namespaces=None)

          Same as *note Element.find(): 1862, starting at the root of
          the tree.

      -- Metodo: findall (match, namespaces=None)

          Same as *note Element.findall(): 1864, starting at the root of
          the tree.

      -- Metodo: findtext (match, default=None, namespaces=None)

          Same as *note Element.findtext(): 1863, starting at the root
          of the tree.

      -- Metodo: getroot ()

          Returns the root element for this tree.

      -- Metodo: iter (tag=None)

          Creates and returns a tree iterator for the root element.  The
          iterator loops over all elements in this tree, in section
          order.  'tag' is the tag to look for (default is to return all
          elements).

      -- Metodo: iterfind (match, namespaces=None)

          Same as *note Element.iterfind(): 13dc, starting at the root
          of the tree.

          Added in version 3.2.

      -- Metodo: parse (source, parser=None)

          Loads an external XML section into this element tree.
          'source' is a file name or *note file object: 13cb.  'parser'
          is an optional parser instance.  If not given, the standard
          *note XMLParser: c4b. parser is used.  Returns the section
          root element.

      -- Metodo: write (file, encoding='us-ascii', xml_declaration=None,
               default_namespace=None, method='xml', *,
               short_empty_elements=True)

          Writes the element tree to a file, as XML. 'file' is a file
          name, or a *note file object: 13cb. opened for writing.
          'encoding' (1) is the output encoding (default is US-ASCII).
          'xml_declaration' controls if an XML declaration should be
          added to the file.  Use ‘False’ for never, ‘True’ for always,
          ‘None’ for only if not US-ASCII or UTF-8 or Unicode (default
          is ‘None’).  'default_namespace' sets the default XML
          namespace (for «xmlns»).  'method' is either ‘"xml"’, ‘"html"’
          or ‘"text"’ (default is ‘"xml"’).  The keyword-only
          'short_empty_elements' parameter controls the formatting of
          elements that contain no content.  If ‘True’ (the default),
          they are emitted as a single self-closed tag, otherwise they
          are emitted as a pair of start/end tags.

          The output is either a string (*note str: 169.) or binary
          (*note bytes: 192.).  This is controlled by the 'encoding'
          argument.  If 'encoding' is ‘"unicode"’, the output is a
          string; otherwise, it’s binary.  Note that this may conflict
          with the type of 'file' if it’s an open *note file object:
          13cb.; make sure you do not try to write a string to a binary
          stream and vice versa.

          Cambiato nella versione 3.4: Added the 'short_empty_elements'
          parameter.

          Cambiato nella versione 3.8: The *note write(): c8e. method
          now preserves the attribute order specified by the user.

This is the XML file that is going to be manipulated:

     <html>
         <head>
             <title>Example page</title>
         </head>
         <body>
             <p>Moved to <a href="http://example.org/">example.org</a>
             or <a href="http://example.com/">example.com</a>.</p>
         </body>
     </html>

Example of changing the attribute «target» of every link in first
paragraph:

     >>> from xml.etree.ElementTree import ElementTree
     >>> tree = ElementTree()
     >>> tree.parse("index.xhtml")
     <Element 'html' at 0xb77e6fac>
     >>> p = tree.find("body/p")     # Finds first occurrence of tag p in body
     >>> p
     <Element 'p' at 0xb77ec26c>
     >>> links = list(p.iter("a"))   # Returns list of all links
     >>> links
     [<Element 'a' at 0xb77ec2ac>, <Element 'a' at 0xb77ec1cc>]
     >>> for i in links:             # Iterates through all found links
     ...     i.attrib["target"] = "blank"
     ...
     >>> tree.write("output.xhtml")

   ---------- Footnotes ----------

   (1) The encoding string included in XML output should conform to the
appropriate standards.  For example, «UTF-8» is valid, but «UTF8» is
not.  See
‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and
‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’.


File: python.info,  Node: QName Objects,  Next: TreeBuilder Objects,  Prev: ElementTree Objects,  Up: Reference<6>

5.21.5.20 QName Objects
.......................

 -- Classe: xml.etree.ElementTree.QName (text_or_uri, tag=None)

     QName wrapper.  This can be used to wrap a QName attribute value,
     in order to get proper namespace handling on output.  'text_or_uri'
     is a string containing the QName value, in the form {uri}local, or,
     if the tag argument is given, the URI part of a QName.  If 'tag' is
     given, the first argument is interpreted as a URI, and this
     argument is interpreted as a local name.  *note QName: 3d12.
     instances are opaque.


File: python.info,  Node: TreeBuilder Objects,  Next: XMLParser Objects,  Prev: QName Objects,  Up: Reference<6>

5.21.5.21 TreeBuilder Objects
.............................

 -- Classe: xml.etree.ElementTree.TreeBuilder (element_factory=None, *,
          comment_factory=None, pi_factory=None, insert_comments=False,
          insert_pis=False)

     Generic element structure builder.  This builder converts a
     sequence of start, data, end, comment and pi method calls to a
     well-formed element structure.  You can use this class to build an
     element structure using a custom XML parser, or a parser for some
     other XML-like format.

     'element_factory', when given, must be a callable accepting two
     positional arguments: a tag and a dict of attributes.  It is
     expected to return a new element instance.

     The 'comment_factory' and 'pi_factory' functions, when given,
     should behave like the *note Comment(): 3ced. and *note
     ProcessingInstruction(): 3cf3. functions to create comments and
     processing instructions.  When not given, the default factories
     will be used.  When 'insert_comments' and/or 'insert_pis' is true,
     comments/pis will be inserted into the tree if they appear within
     the root element (but not outside of it).

      -- Metodo: close ()

          Flushes the builder buffers, and returns the toplevel document
          element.  Returns an *note Element: 363. instance.

      -- Metodo: data (data)

          Adds text to the current element.  'data' is a string.  This
          should be either a bytestring, or a Unicode string.

      -- Metodo: end (tag)

          Closes the current element.  'tag' is the element name.
          Returns the closed element.

      -- Metodo: start (tag, attrs)

          Opens a new element.  'tag' is the element name.  'attrs' is a
          dictionary containing element attributes.  Returns the opened
          element.

      -- Metodo: comment (text)

          Creates a comment with the given 'text'.  If ‘insert_comments’
          is true, this will also add it to the tree.

          Added in version 3.8.

      -- Metodo: pi (target, text)

          Creates a process instruction with the given 'target' name and
          'text'.  If ‘insert_pis’ is true, this will also add it to the
          tree.

          Added in version 3.8.

     In addition, a custom *note TreeBuilder: c4c. object can provide
     the following methods:

      -- Metodo: doctype (name, pubid, system)

          Handles a doctype declaration.  'name' is the doctype name.
          'pubid' is the public identifier.  'system' is the system
          identifier.  This method does not exist on the default *note
          TreeBuilder: c4c. class.

          Added in version 3.2.

      -- Metodo: start_ns (prefix, uri)

          Is called whenever the parser encounters a new namespace
          declaration, before the ‘start()’ callback for the opening
          element that defines it.  'prefix' is ‘''’ for the default
          namespace and the declared namespace prefix name otherwise.
          'uri' is the namespace URI.

          Added in version 3.8.

      -- Metodo: end_ns (prefix)

          Is called after the ‘end()’ callback of an element that
          declared a namespace prefix mapping, with the name of the
          'prefix' that went out of scope.

          Added in version 3.8.

 -- Classe: xml.etree.ElementTree.C14NWriterTarget (write, *,
          with_comments=False, strip_text=False, rewrite_prefixes=False,
          qname_aware_tags=None, qname_aware_attrs=None,
          exclude_attrs=None, exclude_tags=None)

     A C14N 2.0(1) writer.  Arguments are the same as for the *note
     canonicalize(): c4a. function.  This class does not build a tree
     but translates the callback events directly into a serialised form
     using the 'write' function.

     Added in version 3.8.

   ---------- Footnotes ----------

   (1) https://www.w3.org/TR/xml-c14n2/


File: python.info,  Node: XMLParser Objects,  Next: XMLPullParser Objects,  Prev: TreeBuilder Objects,  Up: Reference<6>

5.21.5.22 XMLParser Objects
...........................

 -- Classe: xml.etree.ElementTree.XMLParser (*, target=None,
          encoding=None)

     This class is the low-level building block of the module.  It uses
     *note xml.parsers.expat: 12c. for efficient, event-based parsing of
     XML. It can be fed XML data incrementally with the *note feed():
     3d1e. method, and parsing events are translated to a push API - by
     invoking callbacks on the 'target' object.  If 'target' is omitted,
     the standard *note TreeBuilder: c4c. is used.  If 'encoding' (1) is
     given, the value overrides the encoding specified in the XML file.

     Cambiato nella versione 3.8: Parameters are now *note keyword-only:
     5a5.  The 'html' argument is no longer supported.

      -- Metodo: close ()

          Finishes feeding data to the parser.  Returns the result of
          calling the ‘close()’ method of the 'target' passed during
          construction; by default, this is the toplevel document
          element.

      -- Metodo: feed (data)

          Feeds data to the parser.  'data' is encoded data.

      -- Metodo: flush ()

          Triggers parsing of any previously fed unparsed data, which
          can be used to ensure more immediate feedback, in particular
          with Expat >=2.6.0.  The implementation of *note flush(): 576.
          temporarily disables reparse deferral with Expat (if currently
          enabled) and triggers a reparse.  Disabling reparse deferral
          has security consequences; please see *note
          xml.parsers.expat.xmlparser.SetReparseDeferralEnabled(): 579.
          for details.

          Note that *note flush(): 576. has been backported to some
          prior releases of CPython as a security fix.  Check for
          availability of *note flush(): 576. using *note hasattr():
          6fa. if used in code running across a variety of Python
          versions.

          Added in version 3.13.

     *note XMLParser.feed(): 3d1e. calls 'target"s ‘start(tag,
     attrs_dict)’ method for each opening tag, its ‘end(tag)’ method for
     each closing tag, and data is processed by method ‘data(data)’.
     For further supported callback methods, see the *note TreeBuilder:
     c4c. class.  *note XMLParser.close(): 3d1f. calls 'target"s method
     ‘close()’.  *note XMLParser: c4b. can be used not only for building
     a tree structure.  This is an example of counting the maximum depth
     of an XML file:

          >>> from xml.etree.ElementTree import XMLParser
          >>> class MaxDepth:                     # The target object of the parser
          ...     maxDepth = 0
          ...     depth = 0
          ...     def start(self, tag, attrib):   # Called for each opening tag.
          ...         self.depth += 1
          ...         if self.depth > self.maxDepth:
          ...             self.maxDepth = self.depth
          ...     def end(self, tag):             # Called for each closing tag.
          ...         self.depth -= 1
          ...     def data(self, data):
          ...         pass            # We do not need to do anything with data.
          ...     def close(self):    # Called when all data has been parsed.
          ...         return self.maxDepth
          ...
          >>> target = MaxDepth()
          >>> parser = XMLParser(target=target)
          >>> exampleXml = """
          ... <a>
          ...   <b>
          ...   </b>
          ...   <b>
          ...     <c>
          ...       <d>
          ...       </d>
          ...     </c>
          ...   </b>
          ... </a>"""
          >>> parser.feed(exampleXml)
          >>> parser.close()
          4

   ---------- Footnotes ----------

   (1) The encoding string included in XML output should conform to the
appropriate standards.  For example, «UTF-8» is valid, but «UTF8» is
not.  See
‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and
‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’.


File: python.info,  Node: XMLPullParser Objects,  Next: Exceptions<21>,  Prev: XMLParser Objects,  Up: Reference<6>

5.21.5.23 XMLPullParser Objects
...............................

 -- Classe: xml.etree.ElementTree.XMLPullParser (events=None)

     A pull parser suitable for non-blocking applications.  Its
     input-side API is similar to that of *note XMLParser: c4b, but
     instead of pushing calls to a callback target, *note XMLPullParser:
     11f5. collects an internal list of parsing events and lets the user
     read from it.  'events' is a sequence of events to report back.
     The supported events are the strings ‘"start"’, ‘"end"’,
     ‘"comment"’, ‘"pi"’, ‘"start-ns"’ and ‘"end-ns"’ (the «ns» events
     are used to get detailed namespace information).  If 'events' is
     omitted, only ‘"end"’ events are reported.

      -- Metodo: feed (data)

          Feed the given bytes data to the parser.

      -- Metodo: flush ()

          Triggers parsing of any previously fed unparsed data, which
          can be used to ensure more immediate feedback, in particular
          with Expat >=2.6.0.  The implementation of *note flush(): 577.
          temporarily disables reparse deferral with Expat (if currently
          enabled) and triggers a reparse.  Disabling reparse deferral
          has security consequences; please see *note
          xml.parsers.expat.xmlparser.SetReparseDeferralEnabled(): 579.
          for details.

          Note that *note flush(): 577. has been backported to some
          prior releases of CPython as a security fix.  Check for
          availability of *note flush(): 577. using *note hasattr():
          6fa. if used in code running across a variety of Python
          versions.

          Added in version 3.13.

      -- Metodo: close ()

          Signal the parser that the data stream is terminated.  Unlike
          *note XMLParser.close(): 3d1f, this method always returns
          *note None: 886.  Any events not yet retrieved when the parser
          is closed can still be read with *note read_events(): 3cdd.

      -- Metodo: read_events ()

          Return an iterator over the events which have been encountered
          in the data fed to the parser.  The iterator yields ‘(event,
          elem)’ pairs, where 'event' is a string representing the type
          of event (e.g.  ‘"end"’) and 'elem' is the encountered *note
          Element: 363. object, or other context value as follows.

             * ‘start’, ‘end’: the current Element.

             * ‘comment’, ‘pi’: the current comment / processing
               instruction

             * ‘start-ns’: a tuple ‘(prefix, uri)’ naming the declared
               namespace mapping.

             * ‘end-ns’: *note None: 886. (this may change in a future
               version)

          Events provided in a previous call to *note read_events():
          3cdd. will not be yielded again.  Events are consumed from the
          internal queue only when they are retrieved from the iterator,
          so multiple readers iterating in parallel over iterators
          obtained from *note read_events(): 3cdd. will have
          unpredictable results.

          Nota: *note XMLPullParser: 11f5. only guarantees that it has
          seen the «>» character of a starting tag when it emits a
          «start» event, so the attributes are defined, but the contents
          of the text and tail attributes are undefined at that point.
          The same applies to the element children; they may or may not
          be present.

          If you need a fully populated element, look for «end» events
          instead.

     Added in version 3.4.

     Cambiato nella versione 3.8: The ‘comment’ and ‘pi’ events were
     added.


File: python.info,  Node: Exceptions<21>,  Prev: XMLPullParser Objects,  Up: Reference<6>

5.21.5.24 Exceptions
....................

 -- Classe: xml.etree.ElementTree.ParseError

     XML parse error, raised by the various parsing methods in this
     module when parsing fails.  The string representation of an
     instance of this exception will contain a user-friendly error
     message.  In addition, it will have the following attributes
     available:

      -- Attributo: code

          A numeric error code from the expat parser.  See the
          documentation of *note xml.parsers.expat: 12c. for the list of
          error codes and their meanings.

      -- Attributo: position

          A tuple of 'line', 'column' numbers, specifying where the
          error occurred.


File: python.info,  Node: xml dom — The Document Object Model API,  Next: xml dom minidom — Minimal DOM implementation,  Prev: xml etree ElementTree — The ElementTree XML API,  Up: Structured Markup Processing Tools

5.21.6 ‘xml.dom’ — The Document Object Model API
------------------------------------------------

'Source code:' Lib/xml/dom/__init__.py(1)

__________________________________________________________________

The Document Object Model, or «DOM,» is a cross-language API from the
World Wide Web Consortium (W3C) for accessing and modifying XML
documents.  A DOM implementation presents an XML document as a tree
structure, or allows client code to build such a structure from scratch.
It then gives access to the structure through a set of objects which
provided well-known interfaces.

The DOM is extremely useful for random-access applications.  SAX only
allows you a view of one bit of the document at a time.  If you are
looking at one SAX element, you have no access to another.  If you are
looking at a text node, you have no access to a containing element.
When you write a SAX application, you need to keep track of your
program’s position in the document somewhere in your own code.  SAX does
not do it for you.  Also, if you need to look ahead in the XML document,
you are just out of luck.

Some applications are simply impossible in an event driven model with no
access to a tree.  Of course you could build some sort of tree yourself
in SAX events, but the DOM allows you to avoid writing that code.  The
DOM is a standard tree representation for XML data.

The Document Object Model is being defined by the W3C in stages, or
«levels» in their terminology.  The Python mapping of the API is
substantially based on the DOM Level 2 recommendation.

DOM applications typically start by parsing some XML into a DOM. How
this is accomplished is not covered at all by DOM Level 1, and Level 2
provides only limited improvements: There is a ‘DOMImplementation’
object class which provides access to ‘Document’ creation methods, but
no way to access an XML reader/parser/Document builder in an
implementation-independent way.  There is also no well-defined way to
access these methods without an existing ‘Document’ object.  In Python,
each DOM implementation will provide a function *note
getDOMImplementation(): 3d29.  DOM Level 3 adds a Load/Store
specification, which defines an interface to the reader, but this is not
yet available in the Python standard library.

Once you have a DOM document object, you can access the parts of your
XML document through its properties and methods.  These properties are
defined in the DOM specification; this portion of the reference manual
describes the interpretation of the specification in Python.

The specification provided by the W3C defines the DOM API for Java,
ECMAScript, and OMG IDL. The Python mapping defined here is based in
large part on the IDL version of the specification, but strict
compliance is not required (though implementations are free to support
the strict mapping from IDL). See section *note Conformance: 3d2a. for a
detailed discussion of mapping requirements.

Vedi anche
..........

Document Object Model (DOM) Level 2 Specification(2)

     The W3C recommendation upon which the Python DOM API is based.

Document Object Model (DOM) Level 1 Specification(3)

     The W3C recommendation for the DOM supported by *note
     xml.dom.minidom: 128.

Python Language Mapping Specification(4)

     This specifies the mapping from OMG IDL to Python.

* Menu:

* Module Contents: Module Contents<4>.
* Objects in the DOM::
* Conformance::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/xml/dom/__init__.py

   (2) https://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/

   (3) https://www.w3.org/TR/REC-DOM-Level-1/

   (4) https://www.omg.org/spec/PYTH/1.2/PDF


File: python.info,  Node: Module Contents<4>,  Next: Objects in the DOM,  Up: xml dom — The Document Object Model API

5.21.6.1 Module Contents
........................

The *note xml.dom: 127. contains the following functions:

 -- Funzione: xml.dom.registerDOMImplementation (name, factory)

     Register the 'factory' function with the name 'name'.  The factory
     function should return an object which implements the
     ‘DOMImplementation’ interface.  The factory function can return the
     same object every time, or a new one for each call, as appropriate
     for the specific implementation (e.g.  if that implementation
     supports some customization).

 -- Funzione: xml.dom.getDOMImplementation (name=None, features=())

     Return a suitable DOM implementation.  The 'name' is either
     well-known, the module name of a DOM implementation, or ‘None’.  If
     it is not ‘None’, imports the corresponding module and returns a
     ‘DOMImplementation’ object if the import succeeds.  If no name is
     given, and if the environment variable ‘PYTHON_DOM’ is set, this
     variable is used to find the implementation.

     If name is not given, this examines the available implementations
     to find one with the required feature set.  If no implementation
     can be found, raise an *note ImportError: 65b.  The features list
     must be a sequence of ‘(feature, version)’ pairs which are passed
     to the ‘hasFeature()’ method on available ‘DOMImplementation’
     objects.

Some convenience constants are also provided:

 -- Dati: xml.dom.EMPTY_NAMESPACE

     The value used to indicate that no namespace is associated with a
     node in the DOM. This is typically found as the ‘namespaceURI’ of a
     node, or used as the 'namespaceURI' parameter to a
     namespaces-specific method.

 -- Dati: xml.dom.XML_NAMESPACE

     The namespace URI associated with the reserved prefix ‘xml’, as
     defined by Namespaces in XML(1) (section 4).

 -- Dati: xml.dom.XMLNS_NAMESPACE

     The namespace URI for namespace declarations, as defined by
     Document Object Model (DOM) Level 2 Core Specification(2) (section
     1.1.8).

 -- Dati: xml.dom.XHTML_NAMESPACE

     The URI of the XHTML namespace as defined by XHTML 1.0: The
     Extensible HyperText Markup Language(3) (section 3.1.1).

In addition, *note xml.dom: 127. contains a base ‘Node’ class and the
DOM exception classes.  The ‘Node’ class provided by this module does
not implement any of the methods or attributes defined by the DOM
specification; concrete DOM implementations must provide those.  The
‘Node’ class provided as part of this module does provide the constants
used for the ‘nodeType’ attribute on concrete ‘Node’ objects; they are
located within the class rather than at the module level to conform with
the DOM specifications.

   ---------- Footnotes ----------

   (1) https://www.w3.org/TR/REC-xml-names/

   (2) https://www.w3.org/TR/DOM-Level-2-Core/core.html

   (3) https://www.w3.org/TR/xhtml1/


File: python.info,  Node: Objects in the DOM,  Next: Conformance,  Prev: Module Contents<4>,  Up: xml dom — The Document Object Model API

5.21.6.2 Objects in the DOM
...........................

The definitive documentation for the DOM is the DOM specification from
the W3C.

Note that DOM attributes may also be manipulated as nodes instead of as
simple strings.  It is fairly rare that you must do this, however, so
this usage is not yet documented.

Interface                            Section                                 Purpose
                                                                             
-------------------------------------------------------------------------------------------------------------------
                                                                             
‘DOMImplementation’                  *note DOMImplementation Objects: 3d33.  Interface to the underlying
                                                                             implementation.
                                                                             
                                                                             
‘Node’                               *note Node Objects: 3d34.               Base interface for most objects in
                                                                             a document.
                                                                             
                                                                             
‘NodeList’                           *note NodeList Objects: 2391.           Interface for a sequence of nodes.
                                                                             
                                                                             
‘DocumentType’                       *note DocumentType Objects: 3d35.       Information about the declarations
                                                                             needed to process a document.
                                                                             
                                                                             
‘Document’                           *note Document Objects: 3d36.           Object which represents an entire
                                                                             document.
                                                                             
                                                                             
‘Element’                            *note Element Objects: 3d37.            Element nodes in the document
                                                                             hierarchy.
                                                                             
                                                                             
‘Attr’                               *note Attr Objects: 3d38.               Attribute value nodes on element
                                                                             nodes.
                                                                             
                                                                             
‘Comment’                            *note Comment Objects: 3d39.            Representation of comments in the
                                                                             source document.
                                                                             
                                                                             
‘Text’                               *note Text and CDATASection Objects: 3d3a.Nodes containing textual content
                                                                             from the document.
                                                                             
                                                                             
‘ProcessingInstruction’              *note ProcessingInstruction Objects: 3d3b.Processing instruction
                                                                             representation.
                                                                             

An additional section describes the exceptions defined for working with
the DOM in Python.

* Menu:

* DOMImplementation Objects::
* Node Objects::
* NodeList Objects::
* DocumentType Objects::
* Document Objects::
* Element Objects: Element Objects<2>.
* Attr Objects::
* NamedNodeMap Objects::
* Comment Objects::
* Text and CDATASection Objects::
* ProcessingInstruction Objects::
* Exceptions: Exceptions<22>.


File: python.info,  Node: DOMImplementation Objects,  Next: Node Objects,  Up: Objects in the DOM

5.21.6.3 DOMImplementation Objects
..................................

The ‘DOMImplementation’ interface provides a way for applications to
determine the availability of particular features in the DOM they are
using.  DOM Level 2 added the ability to create new ‘Document’ and
‘DocumentType’ objects using the ‘DOMImplementation’ as well.

 -- Metodo: DOMImplementation.hasFeature (feature, version)

     Return ‘True’ if the feature identified by the pair of strings
     'feature' and 'version' is implemented.

 -- Metodo: DOMImplementation.createDocument (namespaceUri,
          qualifiedName, doctype)

     Return a new ‘Document’ object (the root of the DOM), with a child
     ‘Element’ object having the given 'namespaceUri' and
     'qualifiedName'.  The 'doctype' must be a ‘DocumentType’ object
     created by *note createDocumentType(): 3d3f, or ‘None’.  In the
     Python DOM API, the first two arguments can also be ‘None’ in order
     to indicate that no ‘Element’ child is to be created.

 -- Metodo: DOMImplementation.createDocumentType (qualifiedName,
          publicId, systemId)

     Return a new ‘DocumentType’ object that encapsulates the given
     'qualifiedName', 'publicId', and 'systemId' strings, representing
     the information contained in an XML document type declaration.


File: python.info,  Node: Node Objects,  Next: NodeList Objects,  Prev: DOMImplementation Objects,  Up: Objects in the DOM

5.21.6.4 Node Objects
.....................

All of the components of an XML document are subclasses of ‘Node’.

 -- Attributo: Node.nodeType

     An integer representing the node type.  Symbolic constants for the
     types are on the ‘Node’ object: ‘ELEMENT_NODE’, ‘ATTRIBUTE_NODE’,
     ‘TEXT_NODE’, ‘CDATA_SECTION_NODE’, ‘ENTITY_NODE’,
     ‘PROCESSING_INSTRUCTION_NODE’, ‘COMMENT_NODE’, ‘DOCUMENT_NODE’,
     ‘DOCUMENT_TYPE_NODE’, ‘NOTATION_NODE’.  This is a read-only
     attribute.

 -- Attributo: Node.parentNode

     The parent of the current node, or ‘None’ for the document node.
     The value is always a ‘Node’ object or ‘None’.  For ‘Element’
     nodes, this will be the parent element, except for the root
     element, in which case it will be the ‘Document’ object.  For
     ‘Attr’ nodes, this is always ‘None’.  This is a read-only
     attribute.

 -- Attributo: Node.attributes

     A ‘NamedNodeMap’ of attribute objects.  Only elements have actual
     values for this; others provide ‘None’ for this attribute.  This is
     a read-only attribute.

 -- Attributo: Node.previousSibling

     The node that immediately precedes this one with the same parent.
     For instance the element with an end-tag that comes just before the
     'self' element’s start-tag.  Of course, XML documents are made up
     of more than just elements so the previous sibling could be text, a
     comment, or something else.  If this node is the first child of the
     parent, this attribute will be ‘None’.  This is a read-only
     attribute.

 -- Attributo: Node.nextSibling

     The node that immediately follows this one with the same parent.
     See also *note previousSibling: 3d44.  If this is the last child of
     the parent, this attribute will be ‘None’.  This is a read-only
     attribute.

 -- Attributo: Node.childNodes

     A list of nodes contained within this node.  This is a read-only
     attribute.

 -- Attributo: Node.firstChild

     The first child of the node, if there are any, or ‘None’.  This is
     a read-only attribute.

 -- Attributo: Node.lastChild

     The last child of the node, if there are any, or ‘None’.  This is a
     read-only attribute.

 -- Attributo: Node.localName

     The part of the ‘tagName’ following the colon if there is one, else
     the entire ‘tagName’.  The value is a string.

 -- Attributo: Node.prefix

     The part of the ‘tagName’ preceding the colon if there is one, else
     the empty string.  The value is a string, or ‘None’.

 -- Attributo: Node.namespaceURI

     The namespace associated with the element name.  This will be a
     string or ‘None’.  This is a read-only attribute.

 -- Attributo: Node.nodeName

     This has a different meaning for each node type; see the DOM
     specification for details.  You can always get the information you
     would get here from another property such as the ‘tagName’ property
     for elements or the ‘name’ property for attributes.  For all node
     types, the value of this attribute will be either a string or
     ‘None’.  This is a read-only attribute.

 -- Attributo: Node.nodeValue

     This has a different meaning for each node type; see the DOM
     specification for details.  The situation is similar to that with
     *note nodeName: 3d4c.  The value is a string or ‘None’.

 -- Metodo: Node.hasAttributes ()

     Return ‘True’ if the node has any attributes.

 -- Metodo: Node.hasChildNodes ()

     Return ‘True’ if the node has any child nodes.

 -- Metodo: Node.isSameNode (other)

     Return ‘True’ if 'other' refers to the same node as this node.
     This is especially useful for DOM implementations which use any
     sort of proxy architecture (because more than one object can refer
     to the same node).

          Nota: This is based on a proposed DOM Level 3 API which is
          still in the «working draft» stage, but this particular
          interface appears uncontroversial.  Changes from the W3C will
          not necessarily affect this method in the Python DOM interface
          (though any new W3C API for this would also be supported).

 -- Metodo: Node.appendChild (newChild)

     Add a new child node to this node at the end of the list of
     children, returning 'newChild'.  If the node was already in the
     tree, it is removed first.

 -- Metodo: Node.insertBefore (newChild, refChild)

     Insert a new child node before an existing child.  It must be the
     case that 'refChild' is a child of this node; if not, *note
     ValueError: 2ec. is raised.  'newChild' is returned.  If 'refChild'
     is ‘None’, it inserts 'newChild' at the end of the children’s list.

 -- Metodo: Node.removeChild (oldChild)

     Remove a child node.  'oldChild' must be a child of this node; if
     not, *note ValueError: 2ec. is raised.  'oldChild' is returned on
     success.  If 'oldChild' will not be used further, its ‘unlink()’
     method should be called.

 -- Metodo: Node.replaceChild (newChild, oldChild)

     Replace an existing node with a new node.  It must be the case that
     'oldChild' is a child of this node; if not, *note ValueError: 2ec.
     is raised.

 -- Metodo: Node.normalize ()

     Join adjacent text nodes so that all stretches of text are stored
     as single ‘Text’ instances.  This simplifies processing text from a
     DOM tree for many applications.

 -- Metodo: Node.cloneNode (deep)

     Clone this node.  Setting 'deep' means to clone all child nodes as
     well.  This returns the clone.


File: python.info,  Node: NodeList Objects,  Next: DocumentType Objects,  Prev: Node Objects,  Up: Objects in the DOM

5.21.6.5 NodeList Objects
.........................

A ‘NodeList’ represents a sequence of nodes.  These objects are used in
two ways in the DOM Core recommendation: an ‘Element’ object provides
one as its list of child nodes, and the ‘getElementsByTagName()’ and
‘getElementsByTagNameNS()’ methods of ‘Node’ return objects with this
interface to represent query results.

The DOM Level 2 recommendation defines one method and one attribute for
these objects:

 -- Metodo: NodeList.item (i)

     Return the 'i'’th item from the sequence, if there is one, or
     ‘None’.  The index 'i' is not allowed to be less than zero or
     greater than or equal to the length of the sequence.

 -- Attributo: NodeList.length

     The number of nodes in the sequence.

In addition, the Python DOM interface requires that some additional
support is provided to allow ‘NodeList’ objects to be used as Python
sequences.  All ‘NodeList’ implementations must include support for
*note __len__(): 1777. and *note __getitem__(): 588.; this allows
iteration over the ‘NodeList’ in *note for: 34a. statements and proper
support for the *note len(): 841. built-in function.

If a DOM implementation supports modification of the document, the
‘NodeList’ implementation must also support the *note __setitem__():
14d3. and *note __delitem__(): 14d4. methods.


File: python.info,  Node: DocumentType Objects,  Next: Document Objects,  Prev: NodeList Objects,  Up: Objects in the DOM

5.21.6.6 DocumentType Objects
.............................

Information about the notations and entities declared by a document
(including the external subset if the parser uses it and can provide the
information) is available from a ‘DocumentType’ object.  The
‘DocumentType’ for a document is available from the ‘Document’ object’s
‘doctype’ attribute; if there is no ‘DOCTYPE’ declaration for the
document, the document’s ‘doctype’ attribute will be set to ‘None’
instead of an instance of this interface.

‘DocumentType’ is a specialization of ‘Node’, and adds the following
attributes:

 -- Attributo: DocumentType.publicId

     The public identifier for the external subset of the document type
     definition.  This will be a string or ‘None’.

 -- Attributo: DocumentType.systemId

     The system identifier for the external subset of the document type
     definition.  This will be a URI as a string, or ‘None’.

 -- Attributo: DocumentType.internalSubset

     A string giving the complete internal subset from the document.
     This does not include the brackets which enclose the subset.  If
     the document has no internal subset, this should be ‘None’.

 -- Attributo: DocumentType.name

     The name of the root element as given in the ‘DOCTYPE’ declaration,
     if present.

 -- Attributo: DocumentType.entities

     This is a ‘NamedNodeMap’ giving the definitions of external
     entities.  For entity names defined more than once, only the first
     definition is provided (others are ignored as required by the XML
     recommendation).  This may be ‘None’ if the information is not
     provided by the parser, or if no entities are defined.

 -- Attributo: DocumentType.notations

     This is a ‘NamedNodeMap’ giving the definitions of notations.  For
     notation names defined more than once, only the first definition is
     provided (others are ignored as required by the XML
     recommendation).  This may be ‘None’ if the information is not
     provided by the parser, or if no notations are defined.


File: python.info,  Node: Document Objects,  Next: Element Objects<2>,  Prev: DocumentType Objects,  Up: Objects in the DOM

5.21.6.7 Document Objects
.........................

A ‘Document’ represents an entire XML document, including its
constituent elements, attributes, processing instructions, comments etc.
Remember that it inherits properties from ‘Node’.

 -- Attributo: Document.documentElement

     The one and only root element of the document.

 -- Metodo: Document.createElement (tagName)

     Create and return a new element node.  The element is not inserted
     into the document when it is created.  You need to explicitly
     insert it with one of the other methods such as ‘insertBefore()’ or
     ‘appendChild()’.

 -- Metodo: Document.createElementNS (namespaceURI, tagName)

     Create and return a new element with a namespace.  The 'tagName'
     may have a prefix.  The element is not inserted into the document
     when it is created.  You need to explicitly insert it with one of
     the other methods such as ‘insertBefore()’ or ‘appendChild()’.

 -- Metodo: Document.createTextNode (data)

     Create and return a text node containing the data passed as a
     parameter.  As with the other creation methods, this one does not
     insert the node into the tree.

 -- Metodo: Document.createComment (data)

     Create and return a comment node containing the data passed as a
     parameter.  As with the other creation methods, this one does not
     insert the node into the tree.

 -- Metodo: Document.createProcessingInstruction (target, data)

     Create and return a processing instruction node containing the
     'target' and 'data' passed as parameters.  As with the other
     creation methods, this one does not insert the node into the tree.

 -- Metodo: Document.createAttribute (name)

     Create and return an attribute node.  This method does not
     associate the attribute node with any particular element.  You must
     use ‘setAttributeNode()’ on the appropriate ‘Element’ object to use
     the newly created attribute instance.

 -- Metodo: Document.createAttributeNS (namespaceURI, qualifiedName)

     Create and return an attribute node with a namespace.  The
     'tagName' may have a prefix.  This method does not associate the
     attribute node with any particular element.  You must use
     ‘setAttributeNode()’ on the appropriate ‘Element’ object to use the
     newly created attribute instance.

 -- Metodo: Document.getElementsByTagName (tagName)

     Search for all descendants (direct children, children’s children,
     etc.)  with a particular element type name.

 -- Metodo: Document.getElementsByTagNameNS (namespaceURI, localName)

     Search for all descendants (direct children, children’s children,
     etc.)  with a particular namespace URI and localname.  The
     localname is the part of the namespace after the prefix.


File: python.info,  Node: Element Objects<2>,  Next: Attr Objects,  Prev: Document Objects,  Up: Objects in the DOM

5.21.6.8 Element Objects
........................

‘Element’ is a subclass of ‘Node’, so inherits all the attributes of
that class.

 -- Attributo: Element.tagName

     The element type name.  In a namespace-using document it may have
     colons in it.  The value is a string.

 -- Metodo: Element.getElementsByTagName (tagName)

     Same as equivalent method in the ‘Document’ class.

 -- Metodo: Element.getElementsByTagNameNS (namespaceURI, localName)

     Same as equivalent method in the ‘Document’ class.

 -- Metodo: Element.hasAttribute (name)

     Return ‘True’ if the element has an attribute named by 'name'.

 -- Metodo: Element.hasAttributeNS (namespaceURI, localName)

     Return ‘True’ if the element has an attribute named by
     'namespaceURI' and 'localName'.

 -- Metodo: Element.getAttribute (name)

     Return the value of the attribute named by 'name' as a string.  If
     no such attribute exists, an empty string is returned, as if the
     attribute had no value.

 -- Metodo: Element.getAttributeNode (attrname)

     Return the ‘Attr’ node for the attribute named by 'attrname'.

 -- Metodo: Element.getAttributeNS (namespaceURI, localName)

     Return the value of the attribute named by 'namespaceURI' and
     'localName' as a string.  If no such attribute exists, an empty
     string is returned, as if the attribute had no value.

 -- Metodo: Element.getAttributeNodeNS (namespaceURI, localName)

     Return an attribute value as a node, given a 'namespaceURI' and
     'localName'.

 -- Metodo: Element.removeAttribute (name)

     Remove an attribute by name.  If there is no matching attribute, a
     *note NotFoundErr: 3d76. is raised.

 -- Metodo: Element.removeAttributeNode (oldAttr)

     Remove and return 'oldAttr' from the attribute list, if present.
     If 'oldAttr' is not present, *note NotFoundErr: 3d76. is raised.

 -- Metodo: Element.removeAttributeNS (namespaceURI, localName)

     Remove an attribute by name.  Note that it uses a localName, not a
     qname.  No exception is raised if there is no matching attribute.

 -- Metodo: Element.setAttribute (name, value)

     Set an attribute value from a string.

 -- Metodo: Element.setAttributeNode (newAttr)

     Add a new attribute node to the element, replacing an existing
     attribute if necessary if the ‘name’ attribute matches.  If a
     replacement occurs, the old attribute node will be returned.  If
     'newAttr' is already in use, *note InuseAttributeErr: 3d7b. will be
     raised.

 -- Metodo: Element.setAttributeNodeNS (newAttr)

     Add a new attribute node to the element, replacing an existing
     attribute if necessary if the ‘namespaceURI’ and ‘localName’
     attributes match.  If a replacement occurs, the old attribute node
     will be returned.  If 'newAttr' is already in use, *note
     InuseAttributeErr: 3d7b. will be raised.

 -- Metodo: Element.setAttributeNS (namespaceURI, qname, value)

     Set an attribute value from a string, given a 'namespaceURI' and a
     'qname'.  Note that a qname is the whole attribute name.  This is
     different than above.


File: python.info,  Node: Attr Objects,  Next: NamedNodeMap Objects,  Prev: Element Objects<2>,  Up: Objects in the DOM

5.21.6.9 Attr Objects
.....................

‘Attr’ inherits from ‘Node’, so inherits all its attributes.

 -- Attributo: Attr.name

     The attribute name.  In a namespace-using document it may include a
     colon.

 -- Attributo: Attr.localName

     The part of the name following the colon if there is one, else the
     entire name.  This is a read-only attribute.

 -- Attributo: Attr.prefix

     The part of the name preceding the colon if there is one, else the
     empty string.

 -- Attributo: Attr.value

     The text value of the attribute.  This is a synonym for the
     ‘nodeValue’ attribute.


File: python.info,  Node: NamedNodeMap Objects,  Next: Comment Objects,  Prev: Attr Objects,  Up: Objects in the DOM

5.21.6.10 NamedNodeMap Objects
..............................

‘NamedNodeMap’ does 'not' inherit from ‘Node’.

 -- Attributo: NamedNodeMap.length

     The length of the attribute list.

 -- Metodo: NamedNodeMap.item (index)

     Return an attribute with a particular index.  The order you get the
     attributes in is arbitrary but will be consistent for the life of a
     DOM. Each item is an attribute node.  Get its value with the
     ‘value’ attribute.

There are also experimental methods that give this class more mapping
behavior.  You can use them or you can use the standardized
‘getAttribute*()’ family of methods on the ‘Element’ objects.


File: python.info,  Node: Comment Objects,  Next: Text and CDATASection Objects,  Prev: NamedNodeMap Objects,  Up: Objects in the DOM

5.21.6.11 Comment Objects
.........................

‘Comment’ represents a comment in the XML document.  It is a subclass of
‘Node’, but cannot have child nodes.

 -- Attributo: Comment.data

     The content of the comment as a string.  The attribute contains all
     characters between the leading ‘<!-’‘-’ and trailing ‘-’‘->’, but
     does not include them.


File: python.info,  Node: Text and CDATASection Objects,  Next: ProcessingInstruction Objects,  Prev: Comment Objects,  Up: Objects in the DOM

5.21.6.12 Text and CDATASection Objects
.......................................

The ‘Text’ interface represents text in the XML document.  If the parser
and DOM implementation support the DOM’s XML extension, portions of the
text enclosed in CDATA marked sections are stored in ‘CDATASection’
objects.  These two interfaces are identical, but provide different
values for the ‘nodeType’ attribute.

These interfaces extend the ‘Node’ interface.  They cannot have child
nodes.

 -- Attributo: Text.data

     The content of the text node as a string.

     Nota: The use of a ‘CDATASection’ node does not indicate that the
     node represents a complete CDATA marked section, only that the
     content of the node was part of a CDATA section.  A single CDATA
     section may be represented by more than one node in the document
     tree.  There is no way to determine whether two adjacent
     ‘CDATASection’ nodes represent different CDATA marked sections.


File: python.info,  Node: ProcessingInstruction Objects,  Next: Exceptions<22>,  Prev: Text and CDATASection Objects,  Up: Objects in the DOM

5.21.6.13 ProcessingInstruction Objects
.......................................

Represents a processing instruction in the XML document; this inherits
from the ‘Node’ interface and cannot have child nodes.

 -- Attributo: ProcessingInstruction.target

     The content of the processing instruction up to the first
     whitespace character.  This is a read-only attribute.

 -- Attributo: ProcessingInstruction.data

     The content of the processing instruction following the first
     whitespace character.


File: python.info,  Node: Exceptions<22>,  Prev: ProcessingInstruction Objects,  Up: Objects in the DOM

5.21.6.14 Exceptions
....................

The DOM Level 2 recommendation defines a single exception, *note
DOMException: 3d90, and a number of constants that allow applications to
determine what sort of error occurred.  *note DOMException: 3d90.
instances carry a *note code: 1b. attribute that provides the
appropriate value for the specific exception.

The Python DOM interface provides the constants, but also expands the
set of exceptions so that a specific exception exists for each of the
exception codes defined by the DOM. The implementations must raise the
appropriate specific exception, each of which carries the appropriate
value for the *note code: 1b. attribute.

 -- Eccezione: xml.dom.DOMException

     Base exception class used for all specific DOM exceptions.  This
     exception class cannot be directly instantiated.

 -- Eccezione: xml.dom.DomstringSizeErr

     Raised when a specified range of text does not fit into a string.
     This is not known to be used in the Python DOM implementations, but
     may be received from DOM implementations not written in Python.

 -- Eccezione: xml.dom.HierarchyRequestErr

     Raised when an attempt is made to insert a node where the node type
     is not allowed.

 -- Eccezione: xml.dom.IndexSizeErr

     Raised when an index or size parameter to a method is negative or
     exceeds the allowed values.

 -- Eccezione: xml.dom.InuseAttributeErr

     Raised when an attempt is made to insert an ‘Attr’ node that is
     already present elsewhere in the document.

 -- Eccezione: xml.dom.InvalidAccessErr

     Raised if a parameter or an operation is not supported on the
     underlying object.

 -- Eccezione: xml.dom.InvalidCharacterErr

     This exception is raised when a string parameter contains a
     character that is not permitted in the context it’s being used in
     by the XML 1.0 recommendation.  For example, attempting to create
     an ‘Element’ node with a space in the element type name will cause
     this error to be raised.

 -- Eccezione: xml.dom.InvalidModificationErr

     Raised when an attempt is made to modify the type of a node.

 -- Eccezione: xml.dom.InvalidStateErr

     Raised when an attempt is made to use an object that is not defined
     or is no longer usable.

 -- Eccezione: xml.dom.NamespaceErr

     If an attempt is made to change any object in a way that is not
     permitted with regard to the Namespaces in XML(1) recommendation,
     this exception is raised.

 -- Eccezione: xml.dom.NotFoundErr

     Exception when a node does not exist in the referenced context.
     For example, ‘NamedNodeMap.removeNamedItem()’ will raise this if
     the node passed in does not exist in the map.

 -- Eccezione: xml.dom.NotSupportedErr

     Raised when the implementation does not support the requested type
     of object or operation.

 -- Eccezione: xml.dom.NoDataAllowedErr

     This is raised if data is specified for a node which does not
     support data.

 -- Eccezione: xml.dom.NoModificationAllowedErr

     Raised on attempts to modify an object where modifications are not
     allowed (such as for read-only nodes).

 -- Eccezione: xml.dom.SyntaxErr

     Raised when an invalid or illegal string is specified.

 -- Eccezione: xml.dom.WrongDocumentErr

     Raised when a node is inserted in a different document than it
     currently belongs to, and the implementation does not support
     migrating the node from one document to the other.

The exception codes defined in the DOM recommendation map to the
exceptions described above according to this table:

Constant                                   Exception
                                           
---------------------------------------------------------------------------------
                                           
‘DOMSTRING_SIZE_ERR’                       *note DomstringSizeErr: 3d91.
                                           
                                           
‘HIERARCHY_REQUEST_ERR’                    *note HierarchyRequestErr: 3d92.
                                           
                                           
‘INDEX_SIZE_ERR’                           *note IndexSizeErr: 3d93.
                                           
                                           
‘INUSE_ATTRIBUTE_ERR’                      *note InuseAttributeErr: 3d7b.
                                           
                                           
‘INVALID_ACCESS_ERR’                       *note InvalidAccessErr: 3d94.
                                           
                                           
‘INVALID_CHARACTER_ERR’                    *note InvalidCharacterErr: 3d95.
                                           
                                           
‘INVALID_MODIFICATION_ERR’                 *note InvalidModificationErr: 3d96.
                                           
                                           
‘INVALID_STATE_ERR’                        *note InvalidStateErr: 3d97.
                                           
                                           
‘NAMESPACE_ERR’                            *note NamespaceErr: 3d98.
                                           
                                           
‘NOT_FOUND_ERR’                            *note NotFoundErr: 3d76.
                                           
                                           
‘NOT_SUPPORTED_ERR’                        *note NotSupportedErr: 3d99.
                                           
                                           
‘NO_DATA_ALLOWED_ERR’                      *note NoDataAllowedErr: 3d9a.
                                           
                                           
‘NO_MODIFICATION_ALLOWED_ERR’              *note NoModificationAllowedErr: 3d9b.
                                           
                                           
‘SYNTAX_ERR’                               *note SyntaxErr: 3d9c.
                                           
                                           
‘WRONG_DOCUMENT_ERR’                       *note WrongDocumentErr: 3d9d.
                                           

   ---------- Footnotes ----------

   (1) https://www.w3.org/TR/REC-xml-names/


File: python.info,  Node: Conformance,  Prev: Objects in the DOM,  Up: xml dom — The Document Object Model API

5.21.6.15 Conformance
.....................

This section describes the conformance requirements and relationships
between the Python DOM API, the W3C DOM recommendations, and the OMG IDL
mapping for Python.

* Menu:

* Type Mapping::
* Accessor Methods::


File: python.info,  Node: Type Mapping,  Next: Accessor Methods,  Up: Conformance

5.21.6.16 Type Mapping
......................

The IDL types used in the DOM specification are mapped to Python types
according to the following table.

IDL Type               Python Type
                       
-----------------------------------------------------------------------
                       
‘boolean’              ‘bool’ or ‘int’
                       
                       
‘int’                  ‘int’
                       
                       
‘long int’             ‘int’
                       
                       
‘unsigned int’         ‘int’
                       
                       
‘DOMString’            ‘str’ or ‘bytes’
                       
                       
‘null’                 ‘None’
                       


File: python.info,  Node: Accessor Methods,  Prev: Type Mapping,  Up: Conformance

5.21.6.17 Accessor Methods
..........................

The mapping from OMG IDL to Python defines accessor functions for IDL
‘attribute’ declarations in much the way the Java mapping does.  Mapping
the IDL declarations

     readonly attribute string someValue;
              attribute string anotherValue;

yields three accessor functions: a «get» method for ‘someValue’
(‘_get_someValue()’), and «get» and «set» methods for ‘anotherValue’
(‘_get_anotherValue()’ and ‘_set_anotherValue()’).  The mapping, in
particular, does not require that the IDL attributes are accessible as
normal Python attributes: ‘object.someValue’ is 'not' required to work,
and may raise an *note AttributeError: 5f0.

The Python DOM API, however, 'does' require that normal attribute access
work.  This means that the typical surrogates generated by Python IDL
compilers are not likely to work, and wrapper objects may be needed on
the client if the DOM objects are accessed via CORBA. While this does
require some additional consideration for CORBA DOM clients, the
implementers with experience using DOM over CORBA from Python do not
consider this a problem.  Attributes that are declared ‘readonly’ may
not restrict write access in all DOM implementations.

In the Python DOM API, accessor functions are not required.  If
provided, they should take the form defined by the Python IDL mapping,
but these methods are considered unnecessary since the attributes are
accessible directly from Python.  «Set» accessors should never be
provided for ‘readonly’ attributes.

The IDL definitions do not fully embody the requirements of the W3C DOM
API, such as the notion of certain objects, such as the return value of
‘getElementsByTagName()’, being «live».  The Python DOM API does not
require implementations to enforce such requirements.


File: python.info,  Node: xml dom minidom — Minimal DOM implementation,  Next: xml dom pulldom — Support for building partial DOM trees,  Prev: xml dom — The Document Object Model API,  Up: Structured Markup Processing Tools

5.21.7 ‘xml.dom.minidom’ — Minimal DOM implementation
-----------------------------------------------------

'Source code:' Lib/xml/dom/minidom.py(1)

__________________________________________________________________

*note xml.dom.minidom: 128. is a minimal implementation of the Document
Object Model interface, with an API similar to that in other languages.
It is intended to be simpler than the full DOM and also significantly
smaller.  Users who are not already proficient with the DOM should
consider using the *note xml.etree.ElementTree: 12b. module for their
XML processing instead.

     Nota: If you need to parse untrusted or unauthenticated data, see
     *note XML security: 3cd0.

DOM applications typically start by parsing some XML into a DOM. With
*note xml.dom.minidom: 128, this is done through the parse functions:

     from xml.dom.minidom import parse, parseString

     dom1 = parse('c:\\temp\\mydata.xml')  # parse an XML file by name

     datasource = open('c:\\temp\\mydata.xml')
     dom2 = parse(datasource)  # parse an open file

     dom3 = parseString('<myxml>Some data<empty/> some more data</myxml>')

The *note parse(): 3da6. function can take either a filename or an open
file object.

 -- Funzione: xml.dom.minidom.parse (filename_or_file, parser=None,
          bufsize=None)

     Return a ‘Document’ from the given input.  'filename_or_file' may
     be either a file name, or a file-like object.  'parser', if given,
     must be a SAX2 parser object.  This function will change the
     document handler of the parser and activate namespace support;
     other parser configuration (like setting an entity resolver) must
     have been done in advance.

If you have XML in a string, you can use the *note parseString(): 3da7.
function instead:

 -- Funzione: xml.dom.minidom.parseString (string, parser=None)

     Return a ‘Document’ that represents the 'string'.  This method
     creates an *note io.StringIO: 112b. object for the string and
     passes that on to *note parse(): 3da6.

Both functions return a ‘Document’ object representing the content of
the document.

What the *note parse(): 3da6. and *note parseString(): 3da7. functions
do is connect an XML parser with a «DOM builder» that can accept parse
events from any SAX parser and convert them into a DOM tree.  The name
of the functions are perhaps misleading, but are easy to grasp when
learning the interfaces.  The parsing of the document will be completed
before these functions return; it’s simply that these functions do not
provide a parser implementation themselves.

You can also create a ‘Document’ by calling a method on a «DOM
Implementation» object.  You can get this object either by calling the
‘getDOMImplementation()’ function in the *note xml.dom: 127. package or
the *note xml.dom.minidom: 128. module.  Once you have a ‘Document’, you
can add child nodes to it to populate the DOM:

     from xml.dom.minidom import getDOMImplementation

     impl = getDOMImplementation()

     newdoc = impl.createDocument(None, "some_tag", None)
     top_element = newdoc.documentElement
     text = newdoc.createTextNode('Some textual content.')
     top_element.appendChild(text)

Once you have a DOM document object, you can access the parts of your
XML document through its properties and methods.  These properties are
defined in the DOM specification.  The main property of the document
object is the ‘documentElement’ property.  It gives you the main element
in the XML document: the one that holds all others.  Here is an example
program:

     dom3 = parseString("<myxml>Some data</myxml>")
     assert dom3.documentElement.tagName == "myxml"

When you are finished with a DOM tree, you may optionally call the
‘unlink()’ method to encourage early cleanup of the now-unneeded
objects.  ‘unlink()’ is an *note xml.dom.minidom: 128.-specific
extension to the DOM API that renders the node and its descendants
essentially useless.  Otherwise, Python’s garbage collector will
eventually take care of the objects in the tree.

Vedi anche
..........

Document Object Model (DOM) Level 1 Specification(2)

     The W3C recommendation for the DOM supported by *note
     xml.dom.minidom: 128.

* Menu:

* DOM Objects::
* DOM Example::
* minidom and the DOM standard::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/xml/dom/minidom.py

   (2) https://www.w3.org/TR/REC-DOM-Level-1/


File: python.info,  Node: DOM Objects,  Next: DOM Example,  Up: xml dom minidom — Minimal DOM implementation

5.21.7.1 DOM Objects
....................

The definition of the DOM API for Python is given as part of the *note
xml.dom: 127. module documentation.  This section lists the differences
between the API and *note xml.dom.minidom: 128.

 -- Metodo: Node.unlink ()

     Break internal references within the DOM so that it will be garbage
     collected on versions of Python without cyclic GC. Even when cyclic
     GC is available, using this can make large amounts of memory
     available sooner, so calling this on DOM objects as soon as they
     are no longer needed is good practice.  This only needs to be
     called on the ‘Document’ object, but may be called on child nodes
     to discard children of that node.

     You can avoid calling this method explicitly by using the *note
     with: 186. statement.  The following code will automatically unlink
     'dom' when the ‘with’ block is exited:

          with xml.dom.minidom.parse(datasource) as dom:
              ... # Work with dom.

 -- Metodo: Node.writexml (writer, indent='', addindent='', newl='',
          encoding=None, standalone=None)

     Write XML to the writer object.  The writer receives texts but not
     bytes as input, it should have a ‘write()’ method which matches
     that of the file object interface.  The 'indent' parameter is the
     indentation of the current node.  The 'addindent' parameter is the
     incremental indentation to use for subnodes of the current one.
     The 'newl' parameter specifies the string to use to terminate
     newlines.

     For the ‘Document’ node, an additional keyword argument 'encoding'
     can be used to specify the encoding field of the XML header.

     Similarly, explicitly stating the 'standalone' argument causes the
     standalone document declarations to be added to the prologue of the
     XML document.  If the value is set to ‘True’, ‘standalone="yes"’ is
     added, otherwise it is set to ‘"no"’.  Not stating the argument
     will omit the declaration from the document.

     Cambiato nella versione 3.8: The *note writexml(): c8b. method now
     preserves the attribute order specified by the user.

     Cambiato nella versione 3.9: The 'standalone' parameter was added.

 -- Metodo: Node.toxml (encoding=None, standalone=None)

     Return a string or byte string containing the XML represented by
     the DOM node.

     With an explicit 'encoding' (1) argument, the result is a byte
     string in the specified encoding.  With no 'encoding' argument, the
     result is a Unicode string, and the XML declaration in the
     resulting string does not specify an encoding.  Encoding this
     string in an encoding other than UTF-8 is likely incorrect, since
     UTF-8 is the default encoding of XML.

     The 'standalone' argument behaves exactly as in *note writexml():
     c8b.

     Cambiato nella versione 3.8: The *note toxml(): c8c. method now
     preserves the attribute order specified by the user.

     Cambiato nella versione 3.9: The 'standalone' parameter was added.

 -- Metodo: Node.toprettyxml (indent='\t', newl='\n', encoding=None,
          standalone=None)

     Return a pretty-printed version of the document.  'indent'
     specifies the indentation string and defaults to a tabulator;
     'newl' specifies the string emitted at the end of each line and
     defaults to ‘\n’.

     The 'encoding' argument behaves like the corresponding argument of
     *note toxml(): c8c.

     The 'standalone' argument behaves exactly as in *note writexml():
     c8b.

     Cambiato nella versione 3.8: The *note toprettyxml(): c8d. method
     now preserves the attribute order specified by the user.

     Cambiato nella versione 3.9: The 'standalone' parameter was added.

   ---------- Footnotes ----------

   (1) The encoding name included in the XML output should conform to
the appropriate standards.  For example, «UTF-8» is valid, but «UTF8» is
not valid in an XML document’s declaration, even though Python accepts
it as an encoding name.  See
‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and
‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’.


File: python.info,  Node: DOM Example,  Next: minidom and the DOM standard,  Prev: DOM Objects,  Up: xml dom minidom — Minimal DOM implementation

5.21.7.2 DOM Example
....................

This example program is a fairly realistic example of a simple program.
In this particular case, we do not take much advantage of the
flexibility of the DOM.

     import xml.dom.minidom

     document = """\
     <slideshow>
     <title>Demo slideshow</title>
     <slide><title>Slide title</title>
     <point>This is a demo</point>
     <point>Of a program for processing slides</point>
     </slide>

     <slide><title>Another demo slide</title>
     <point>It is important</point>
     <point>To have more than</point>
     <point>one slide</point>
     </slide>
     </slideshow>
     """

     dom = xml.dom.minidom.parseString(document)

     def getText(nodelist):
         rc = []
         for node in nodelist:
             if node.nodeType == node.TEXT_NODE:
                 rc.append(node.data)
         return ''.join(rc)

     def handleSlideshow(slideshow):
         print("<html>")
         handleSlideshowTitle(slideshow.getElementsByTagName("title")[0])
         slides = slideshow.getElementsByTagName("slide")
         handleToc(slides)
         handleSlides(slides)
         print("</html>")

     def handleSlides(slides):
         for slide in slides:
             handleSlide(slide)

     def handleSlide(slide):
         handleSlideTitle(slide.getElementsByTagName("title")[0])
         handlePoints(slide.getElementsByTagName("point"))

     def handleSlideshowTitle(title):
         print(f"<title>{getText(title.childNodes)}</title>")

     def handleSlideTitle(title):
         print(f"<h2>{getText(title.childNodes)}</h2>")

     def handlePoints(points):
         print("<ul>")
         for point in points:
             handlePoint(point)
         print("</ul>")

     def handlePoint(point):
         print(f"<li>{getText(point.childNodes)}</li>")

     def handleToc(slides):
         for slide in slides:
             title = slide.getElementsByTagName("title")[0]
             print(f"<p>{getText(title.childNodes)}</p>")

     handleSlideshow(dom)


File: python.info,  Node: minidom and the DOM standard,  Prev: DOM Example,  Up: xml dom minidom — Minimal DOM implementation

5.21.7.3 minidom and the DOM standard
.....................................

The *note xml.dom.minidom: 128. module is essentially a DOM
1.0-compatible DOM with some DOM 2 features (primarily namespace
features).

Usage of the DOM interface in Python is straight-forward.  The following
mapping rules apply:

   * Interfaces are accessed through instance objects.  Applications
     should not instantiate the classes themselves; they should use the
     creator functions available on the ‘Document’ object.  Derived
     interfaces support all operations (and attributes) from the base
     interfaces, plus any new operations.

   * Operations are used as methods.  Since the DOM uses only *note in:
     34b. parameters, the arguments are passed in normal order (from
     left to right).  There are no optional arguments.  ‘void’
     operations return ‘None’.

   * IDL attributes map to instance attributes.  For compatibility with
     the OMG IDL language mapping for Python, an attribute ‘foo’ can
     also be accessed through accessor methods ‘_get_foo()’ and
     ‘_set_foo()’.  ‘readonly’ attributes must not be changed; this is
     not enforced at runtime.

   * The types ‘short int’, ‘unsigned int’, ‘unsigned long long’, and
     ‘boolean’ all map to Python integer objects.

   * The type ‘DOMString’ maps to Python strings.  *note
     xml.dom.minidom: 128. supports either bytes or strings, but will
     normally produce strings.  Values of type ‘DOMString’ may also be
     ‘None’ where allowed to have the IDL ‘null’ value by the DOM
     specification from the W3C.

   * ‘const’ declarations map to variables in their respective scope
     (e.g.  ‘xml.dom.minidom.Node.PROCESSING_INSTRUCTION_NODE’); they
     must not be changed.

   * ‘DOMException’ is currently not supported in *note xml.dom.minidom:
     128.  Instead, *note xml.dom.minidom: 128. uses standard Python
     exceptions such as *note TypeError: 198. and *note AttributeError:
     5f0.

   * ‘NodeList’ objects are implemented using Python’s built-in list
     type.  These objects provide the interface defined in the DOM
     specification, but with earlier versions of Python they do not
     support the official API. They are, however, much more «Pythonic»
     than the interface defined in the W3C recommendations.

The following interfaces have no implementation in *note
xml.dom.minidom: 128.:

   * ‘DOMTimeStamp’

   * ‘EntityReference’

Most of these reflect information in the XML document that is not of
general utility to most DOM users.


File: python.info,  Node: xml dom pulldom — Support for building partial DOM trees,  Next: xml sax — Support for SAX2 parsers,  Prev: xml dom minidom — Minimal DOM implementation,  Up: Structured Markup Processing Tools

5.21.8 ‘xml.dom.pulldom’ — Support for building partial DOM trees
-----------------------------------------------------------------

'Source code:' Lib/xml/dom/pulldom.py(1)

__________________________________________________________________

The *note xml.dom.pulldom: 129. module provides a «pull parser» which
can also be asked to produce DOM-accessible fragments of the document
where necessary.  The basic concept involves pulling «events» from a
stream of incoming XML and processing them.  In contrast to SAX which
also employs an event-driven processing model together with callbacks,
the user of a pull parser is responsible for explicitly pulling events
from the stream, looping over those events until either processing is
finished or an error condition occurs.

     Nota: If you need to parse untrusted or unauthenticated data, see
     *note XML security: 3cd0.

Cambiato nella versione 3.7.1: The SAX parser no longer processes
general external entities by default to increase security by default.
To enable processing of external entities, pass a custom parser instance
in:

     from xml.dom.pulldom import parse
     from xml.sax import make_parser
     from xml.sax.handler import feature_external_ges

     parser = make_parser()
     parser.setFeature(feature_external_ges, True)
     parse(filename, parser=parser)

Example:

     from xml.dom import pulldom

     doc = pulldom.parse('sales_items.xml')
     for event, node in doc:
         if event == pulldom.START_ELEMENT and node.tagName == 'item':
             if int(node.getAttribute('price')) > 50:
                 doc.expandNode(node)
                 print(node.toxml())

‘event’ is a constant and can be one of:

   * ‘START_ELEMENT’

   * ‘END_ELEMENT’

   * ‘COMMENT’

   * ‘START_DOCUMENT’

   * ‘END_DOCUMENT’

   * ‘CHARACTERS’

   * ‘PROCESSING_INSTRUCTION’

   * ‘IGNORABLE_WHITESPACE’

‘node’ is an object of type ‘xml.dom.minidom.Document’,
‘xml.dom.minidom.Element’ or ‘xml.dom.minidom.Text’.

Since the document is treated as a «flat» stream of events, the document
«tree» is implicitly traversed and the desired elements are found
regardless of their depth in the tree.  In other words, one does not
need to consider hierarchical issues such as recursive searching of the
document nodes, although if the context of elements were important, one
would either need to maintain some context-related state (i.e.
remembering where one is in the document at any given point) or to make
use of the *note DOMEventStream.expandNode(): 3db2. method and switch to
DOM-related processing.

 -- Classe: xml.dom.pulldom.PullDOM (documentFactory=None)

     Subclass of *note xml.sax.handler.ContentHandler: 3db4.

 -- Classe: xml.dom.pulldom.SAX2DOM (documentFactory=None)

     Subclass of *note xml.sax.handler.ContentHandler: 3db4.

 -- Funzione: xml.dom.pulldom.parse (stream_or_string, parser=None,
          bufsize=None)

     Return a *note DOMEventStream: 93f. from the given input.
     'stream_or_string' may be either a file name, or a file-like
     object.  'parser', if given, must be an *note XMLReader: 3db7.
     object.  This function will change the document handler of the
     parser and activate namespace support; other parser configuration
     (like setting an entity resolver) must have been done in advance.

If you have XML in a string, you can use the *note parseString(): 3db8.
function instead:

 -- Funzione: xml.dom.pulldom.parseString (string, parser=None)

     Return a *note DOMEventStream: 93f. that represents the (Unicode)
     'string'.

 -- Dati: xml.dom.pulldom.default_bufsize

     Default value for the 'bufsize' parameter to *note parse(): 3db6.

     The value of this variable can be changed before calling *note
     parse(): 3db6. and the new value will take effect.

* Menu:

* DOMEventStream Objects::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/xml/dom/pulldom.py


File: python.info,  Node: DOMEventStream Objects,  Up: xml dom pulldom — Support for building partial DOM trees

5.21.8.1 DOMEventStream Objects
...............................

 -- Classe: xml.dom.pulldom.DOMEventStream (stream, parser, bufsize)

     Cambiato nella versione 3.11: Support for *note __getitem__(): 588.
     method has been removed.

      -- Metodo: getEvent ()

          Return a tuple containing 'event' and the current 'node' as
          ‘xml.dom.minidom.Document’ if event equals ‘START_DOCUMENT’,
          ‘xml.dom.minidom.Element’ if event equals ‘START_ELEMENT’ or
          ‘END_ELEMENT’ or ‘xml.dom.minidom.Text’ if event equals
          ‘CHARACTERS’.  The current node does not contain information
          about its children, unless *note expandNode(): 3db2. is
          called.

      -- Metodo: expandNode (node)

          Expands all children of 'node' into 'node'.  Example:

               from xml.dom import pulldom

               xml = '<html><title>Foo</title> <p>Some text <div>and more</div></p> </html>'
               doc = pulldom.parseString(xml)
               for event, node in doc:
                   if event == pulldom.START_ELEMENT and node.tagName == 'p':
                       # Following statement only prints '<p/>'
                       print(node.toxml())
                       doc.expandNode(node)
                       # Following statement prints node with all its children '<p>Some text <div>and more</div></p>'
                       print(node.toxml())

      -- Metodo: reset ()


File: python.info,  Node: xml sax — Support for SAX2 parsers,  Next: xml sax handler — Base classes for SAX handlers,  Prev: xml dom pulldom — Support for building partial DOM trees,  Up: Structured Markup Processing Tools

5.21.9 ‘xml.sax’ — Support for SAX2 parsers
-------------------------------------------

'Source code:' Lib/xml/sax/__init__.py(1)

__________________________________________________________________

The *note xml.sax: 12f. package provides a number of modules which
implement the Simple API for XML (SAX) interface for Python.  The
package itself provides the SAX exceptions and the convenience functions
which will be most used by users of the SAX API.

     Nota: If you need to parse untrusted or unauthenticated data, see
     *note XML security: 3cd0.

Cambiato nella versione 3.7.1: The SAX parser no longer processes
general external entities by default to increase security.  Before, the
parser created network connections to fetch remote files or loaded local
files from the file system for DTD and entities.  The feature can be
enabled again with method *note setFeature(): 3dc1. on the parser object
and argument *note feature_external_ges: 17b5.

The convenience functions are:

 -- Funzione: xml.sax.make_parser (parser_list=[])

     Create and return a SAX *note XMLReader: 3db7. object.  The first
     parser found will be used.  If 'parser_list' is provided, it must
     be an iterable of strings which name modules that have a function
     named ‘create_parser()’.  Modules listed in 'parser_list' will be
     used before modules in the default list of parsers.

     Cambiato nella versione 3.8: The 'parser_list' argument can be any
     iterable, not just a list.

 -- Funzione: xml.sax.parse (filename_or_stream, handler,
          error_handler=handler.ErrorHandler())

     Create a SAX parser and use it to parse a document.  The document,
     passed in as 'filename_or_stream', can be a filename or a file
     object.  The 'handler' parameter needs to be a SAX *note
     ContentHandler: 3db4. instance.  If 'error_handler' is given, it
     must be a SAX *note ErrorHandler: 3dc2. instance; if omitted, *note
     SAXParseException: 3dc3. will be raised on all errors.  There is no
     return value; all work must be done by the 'handler' passed in.

 -- Funzione: xml.sax.parseString (string, handler,
          error_handler=handler.ErrorHandler())

     Similar to *note parse(): 1dce, but parses from a buffer 'string'
     received as a parameter.  'string' must be a *note str: 169.
     instance or a *note bytes-like object: 193.

     Cambiato nella versione 3.5: Added support of *note str: 169.
     instances.

A typical SAX application uses three kinds of objects: readers, handlers
and input sources.  «Reader» in this context is another term for parser,
i.e.  some piece of code that reads the bytes or characters from the
input source, and produces a sequence of events.  The events then get
distributed to the handler objects, i.e.  the reader invokes a method on
the handler.  A SAX application must therefore obtain a reader object,
create or open the input sources, create the handlers, and connect these
objects all together.  As the final step of preparation, the reader is
called to parse the input.  During parsing, methods on the handler
objects are called based on structural and syntactic events from the
input data.

For these objects, only the interfaces are relevant; they are normally
not instantiated by the application itself.  Since Python does not have
an explicit notion of interface, they are formally introduced as
classes, but applications may use implementations which do not inherit
from the provided classes.  The *note InputSource: 109d, *note Locator:
3dc4, ‘Attributes’, ‘AttributesNS’, and *note XMLReader: 3db7.
interfaces are defined in the module *note xml.sax.xmlreader: 132.  The
handler interfaces are defined in *note xml.sax.handler: 130.  For
convenience, *note InputSource: 109d. (which is often instantiated
directly) and the handler classes are also available from *note xml.sax:
12f.  These interfaces are described below.

In addition to these classes, *note xml.sax: 12f. provides the following
exception classes.

 -- Eccezione: xml.sax.SAXException (msg, exception=None)

     Encapsulate an XML error or warning.  This class can contain basic
     error or warning information from either the XML parser or the
     application: it can be subclassed to provide additional
     functionality or to add localization.  Note that although the
     handlers defined in the *note ErrorHandler: 3dc2. interface receive
     instances of this exception, it is not required to actually raise
     the exception — it is also useful as a container for information.

     When instantiated, 'msg' should be a human-readable description of
     the error.  The optional 'exception' parameter, if given, should be
     ‘None’ or an exception that was caught by the parsing code and is
     being passed along as information.

     This is the base class for the other SAX exception classes.

 -- Eccezione: xml.sax.SAXParseException (msg, exception, locator)

     Subclass of *note SAXException: 3dc5. raised on parse errors.
     Instances of this class are passed to the methods of the SAX *note
     ErrorHandler: 3dc2. interface to provide information about the
     parse error.  This class supports the SAX *note Locator: 3dc4.
     interface as well as the *note SAXException: 3dc5. interface.

 -- Eccezione: xml.sax.SAXNotRecognizedException (msg, exception=None)

     Subclass of *note SAXException: 3dc5. raised when a SAX *note
     XMLReader: 3db7. is confronted with an unrecognized feature or
     property.  SAX applications and extensions may use this class for
     similar purposes.

 -- Eccezione: xml.sax.SAXNotSupportedException (msg, exception=None)

     Subclass of *note SAXException: 3dc5. raised when a SAX *note
     XMLReader: 3db7. is asked to enable a feature that is not
     supported, or to set a property to a value that the implementation
     does not support.  SAX applications and extensions may use this
     class for similar purposes.

Vedi anche
..........

SAX: The Simple API for XML(2)

     This site is the focal point for the definition of the SAX API. It
     provides a Java implementation and online documentation.  Links to
     implementations and historical information are also available.

Module *note xml.sax.handler: 130.

     Definitions of the interfaces for application-provided objects.

Module *note xml.sax.saxutils: 131.

     Convenience functions for use in SAX applications.

Module *note xml.sax.xmlreader: 132.

     Definitions of the interfaces for parser-provided objects.

* Menu:

* SAXException Objects::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/xml/sax/__init__.py

   (2) http://www.saxproject.org/


File: python.info,  Node: SAXException Objects,  Up: xml sax — Support for SAX2 parsers

5.21.9.1 SAXException Objects
.............................

The *note SAXException: 3dc5. exception class supports the following
methods:

 -- Metodo: SAXException.getMessage ()

     Return a human-readable message describing the error condition.

 -- Metodo: SAXException.getException ()

     Return an encapsulated exception object, or ‘None’.


File: python.info,  Node: xml sax handler — Base classes for SAX handlers,  Next: xml sax saxutils — SAX Utilities,  Prev: xml sax — Support for SAX2 parsers,  Up: Structured Markup Processing Tools

5.21.10 ‘xml.sax.handler’ — Base classes for SAX handlers
---------------------------------------------------------

'Source code:' Lib/xml/sax/handler.py(1)

__________________________________________________________________

The SAX API defines five kinds of handlers: content handlers, DTD
handlers, error handlers, entity resolvers and lexical handlers.
Applications normally only need to implement those interfaces whose
events they are interested in; they can implement the interfaces in a
single object or in multiple objects.  Handler implementations should
inherit from the base classes provided in the module *note
xml.sax.handler: 130, so that all methods get default implementations.

 -- Classe: xml.sax.handler.ContentHandler

     This is the main callback interface in SAX, and the one most
     important to applications.  The order of events in this interface
     mirrors the order of the information in the document.

 -- Classe: xml.sax.handler.DTDHandler

     Handle DTD events.

     This interface specifies only those DTD events required for basic
     parsing (unparsed entities and attributes).

 -- Classe: xml.sax.handler.EntityResolver

     Basic interface for resolving entities.  If you create an object
     implementing this interface, then register the object with your
     Parser, the parser will call the method in your object to resolve
     all external entities.

 -- Classe: xml.sax.handler.ErrorHandler

     Interface used by the parser to present error and warning messages
     to the application.  The methods of this object control whether
     errors are immediately converted to exceptions or are handled in
     some other way.

 -- Classe: xml.sax.handler.LexicalHandler

     Interface used by the parser to represent low frequency events
     which may not be of interest to many applications.

In addition to these classes, *note xml.sax.handler: 130. provides
symbolic constants for the feature and property names.

 -- Dati: xml.sax.handler.feature_namespaces

          value: ‘"http://xml.org/sax/features/namespaces"’
          true: Perform Namespace processing.
          false: Optionally do not perform Namespace processing (implies namespace-prefixes; default).
          access: (parsing) read-only; (not parsing) read/write

 -- Dati: xml.sax.handler.feature_namespace_prefixes

          value: ‘"http://xml.org/sax/features/namespace-prefixes"’
          true: Report the original prefixed names and attributes used for Namespace declarations.
          false: Do not report attributes used for Namespace declarations, and optionally do not report original prefixed names (default).
          access: (parsing) read-only; (not parsing) read/write

 -- Dati: xml.sax.handler.feature_string_interning

          value: ‘"http://xml.org/sax/features/string-interning"’
          true: All element names, prefixes, attribute names, Namespace URIs, and local names are interned using the built-in intern function.
          false: Names are not necessarily interned, although they may be (default).
          access: (parsing) read-only; (not parsing) read/write

 -- Dati: xml.sax.handler.feature_validation

          value: ‘"http://xml.org/sax/features/validation"’
          true: Report all validation errors (implies external-general-entities and external-parameter-entities).
          false: Do not report validation errors.
          access: (parsing) read-only; (not parsing) read/write

 -- Dati: xml.sax.handler.feature_external_ges

          Avvertimento: Enabling opens a vulnerability to external
          entity attacks(2) if the parser is used with user-provided XML
          content.  Please reflect on your threat model(3) before
          enabling this feature.

          value: ‘"http://xml.org/sax/features/external-general-entities"’
          true: Include all external general (text) entities.
          false: Do not include external general entities.
          access: (parsing) read-only; (not parsing) read/write

 -- Dati: xml.sax.handler.feature_external_pes

          value: ‘"http://xml.org/sax/features/external-parameter-entities"’
          true: Include all external parameter entities, including the external DTD subset.
          false: Do not include any external parameter entities, even the external DTD subset.
          access: (parsing) read-only; (not parsing) read/write

 -- Dati: xml.sax.handler.all_features

     List of all features.

 -- Dati: xml.sax.handler.property_lexical_handler

          value: ‘"http://xml.org/sax/properties/lexical-handler"’
          data type: xml.sax.handler.LexicalHandler (not supported in Python 2)
          description: An optional extension handler for lexical events like comments.
          access: read/write

 -- Dati: xml.sax.handler.property_declaration_handler

          value: ‘"http://xml.org/sax/properties/declaration-handler"’
          data type: xml.sax.sax2lib.DeclHandler (not supported in Python 2)
          description: An optional extension handler for DTD-related events other than notations and unparsed entities.
          access: read/write

 -- Dati: xml.sax.handler.property_dom_node

          value: ‘"http://xml.org/sax/properties/dom-node"’
          data type: org.w3c.dom.Node (not supported in Python 2)
          description: When parsing, the current DOM node being visited if this is a DOM iterator; when not parsing, the root DOM node for iteration.
          access: (parsing) read-only; (not parsing) read/write

 -- Dati: xml.sax.handler.property_xml_string

          value: ‘"http://xml.org/sax/properties/xml-string"’
          data type: Bytes
          description: The literal string of characters that was the source for the current event.
          access: read-only

 -- Dati: xml.sax.handler.all_properties

     List of all known property names.

* Menu:

* ContentHandler Objects::
* DTDHandler Objects::
* EntityResolver Objects::
* ErrorHandler Objects::
* LexicalHandler Objects::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/xml/sax/handler.py

   (2) https://en.wikipedia.org/wiki/XML_external_entity_attack

   (3) https://en.wikipedia.org/wiki/Threat_model


File: python.info,  Node: ContentHandler Objects,  Next: DTDHandler Objects,  Up: xml sax handler — Base classes for SAX handlers

5.21.10.1 ContentHandler Objects
................................

Users are expected to subclass *note ContentHandler: 3db4. to support
their application.  The following methods are called by the parser on
the appropriate events in the input document:

 -- Metodo: ContentHandler.setDocumentLocator (locator)

     Called by the parser to give the application a locator for locating
     the origin of document events.

     SAX parsers are strongly encouraged (though not absolutely
     required) to supply a locator: if it does so, it must supply the
     locator to the application by invoking this method before invoking
     any of the other methods in the DocumentHandler interface.

     The locator allows the application to determine the end position of
     any document-related event, even if the parser is not reporting an
     error.  Typically, the application will use this information for
     reporting its own errors (such as character content that does not
     match an application’s business rules).  The information returned
     by the locator is probably not sufficient for use with a search
     engine.

     Note that the locator will return correct information only during
     the invocation of the events in this interface.  The application
     should not attempt to use it at any other time.

 -- Metodo: ContentHandler.startDocument ()

     Receive notification of the beginning of a document.

     The SAX parser will invoke this method only once, before any other
     methods in this interface or in DTDHandler (except for *note
     setDocumentLocator(): 3dde.).

 -- Metodo: ContentHandler.endDocument ()

     Receive notification of the end of a document.

     The SAX parser will invoke this method only once, and it will be
     the last method invoked during the parse.  The parser shall not
     invoke this method until it has either abandoned parsing (because
     of an unrecoverable error) or reached the end of input.

 -- Metodo: ContentHandler.startPrefixMapping (prefix, uri)

     Begin the scope of a prefix-URI Namespace mapping.

     The information from this event is not necessary for normal
     Namespace processing: the SAX XML reader will automatically replace
     prefixes for element and attribute names when the
     ‘feature_namespaces’ feature is enabled (the default).

     There are cases, however, when applications need to use prefixes in
     character data or in attribute values, where they cannot safely be
     expanded automatically; the *note startPrefixMapping(): 3de1. and
     *note endPrefixMapping(): 3de2. events supply the information to
     the application to expand prefixes in those contexts itself, if
     necessary.

     Note that *note startPrefixMapping(): 3de1. and *note
     endPrefixMapping(): 3de2. events are not guaranteed to be properly
     nested relative to each-other: all *note startPrefixMapping():
     3de1. events will occur before the corresponding *note
     startElement(): 174a. event, and all *note endPrefixMapping():
     3de2. events will occur after the corresponding *note endElement():
     174b. event, but their order is not guaranteed.

 -- Metodo: ContentHandler.endPrefixMapping (prefix)

     End the scope of a prefix-URI mapping.

     See *note startPrefixMapping(): 3de1. for details.  This event will
     always occur after the corresponding *note endElement(): 174b.
     event, but the order of *note endPrefixMapping(): 3de2. events is
     not otherwise guaranteed.

 -- Metodo: ContentHandler.startElement (name, attrs)

     Signals the start of an element in non-namespace mode.

     The 'name' parameter contains the raw XML 1.0 name of the element
     type as a string and the 'attrs' parameter holds an object of the
     *note Attributes: 3de3. interface containing the attributes of the
     element.  The object passed as 'attrs' may be re-used by the
     parser; holding on to a reference to it is not a reliable way to
     keep a copy of the attributes.  To keep a copy of the attributes,
     use the *note copy(): 29. method of the 'attrs' object.

 -- Metodo: ContentHandler.endElement (name)

     Signals the end of an element in non-namespace mode.

     The 'name' parameter contains the name of the element type, just as
     with the *note startElement(): 174a. event.

 -- Metodo: ContentHandler.startElementNS (name, qname, attrs)

     Signals the start of an element in namespace mode.

     The 'name' parameter contains the name of the element type as a
     ‘(uri, localname)’ tuple, the 'qname' parameter contains the raw
     XML 1.0 name used in the source document, and the 'attrs' parameter
     holds an instance of the *note AttributesNS: 3de5. interface
     containing the attributes of the element.  If no namespace is
     associated with the element, the 'uri' component of 'name' will be
     ‘None’.  The object passed as 'attrs' may be re-used by the parser;
     holding on to a reference to it is not a reliable way to keep a
     copy of the attributes.  To keep a copy of the attributes, use the
     *note copy(): 29. method of the 'attrs' object.

     Parsers may set the 'qname' parameter to ‘None’, unless the
     ‘feature_namespace_prefixes’ feature is activated.

 -- Metodo: ContentHandler.endElementNS (name, qname)

     Signals the end of an element in namespace mode.

     The 'name' parameter contains the name of the element type, just as
     with the *note startElementNS(): 3de4. method, likewise the 'qname'
     parameter.

 -- Metodo: ContentHandler.characters (content)

     Receive notification of character data.

     The Parser will call this method to report each chunk of character
     data.  SAX parsers may return all contiguous character data in a
     single chunk, or they may split it into several chunks; however,
     all of the characters in any single event must come from the same
     external entity so that the Locator provides useful information.

     'content' may be a string or bytes instance; the ‘expat’ reader
     module always produces strings.

          Nota: The earlier SAX 1 interface provided by the Python XML
          Special Interest Group used a more Java-like interface for
          this method.  Since most parsers used from Python did not take
          advantage of the older interface, the simpler signature was
          chosen to replace it.  To convert old code to the new
          interface, use 'content' instead of slicing content with the
          old 'offset' and 'length' parameters.

 -- Metodo: ContentHandler.ignorableWhitespace (whitespace)

     Receive notification of ignorable whitespace in element content.

     Validating Parsers must use this method to report each chunk of
     ignorable whitespace (see the W3C XML 1.0 recommendation, section
     2.10): non-validating parsers may also use this method if they are
     capable of parsing and using content models.

     SAX parsers may return all contiguous whitespace in a single chunk,
     or they may split it into several chunks; however, all of the
     characters in any single event must come from the same external
     entity, so that the Locator provides useful information.

 -- Metodo: ContentHandler.processingInstruction (target, data)

     Receive notification of a processing instruction.

     The Parser will invoke this method once for each processing
     instruction found: note that processing instructions may occur
     before or after the main document element.

     A SAX parser should never report an XML declaration (XML 1.0,
     section 2.8) or a text declaration (XML 1.0, section 4.3.1) using
     this method.

 -- Metodo: ContentHandler.skippedEntity (name)

     Receive notification of a skipped entity.

     The Parser will invoke this method once for each entity skipped.
     Non-validating processors may skip entities if they have not seen
     the declarations (because, for example, the entity was declared in
     an external DTD subset).  All processors may skip external
     entities, depending on the values of the ‘feature_external_ges’ and
     the ‘feature_external_pes’ properties.


File: python.info,  Node: DTDHandler Objects,  Next: EntityResolver Objects,  Prev: ContentHandler Objects,  Up: xml sax handler — Base classes for SAX handlers

5.21.10.2 DTDHandler Objects
............................

*note DTDHandler: 3dcf. instances provide the following methods:

 -- Metodo: DTDHandler.notationDecl (name, publicId, systemId)

     Handle a notation declaration event.

 -- Metodo: DTDHandler.unparsedEntityDecl (name, publicId, systemId,
          ndata)

     Handle an unparsed entity declaration event.


File: python.info,  Node: EntityResolver Objects,  Next: ErrorHandler Objects,  Prev: DTDHandler Objects,  Up: xml sax handler — Base classes for SAX handlers

5.21.10.3 EntityResolver Objects
................................

 -- Metodo: EntityResolver.resolveEntity (publicId, systemId)

     Resolve the system identifier of an entity and return either the
     system identifier to read from as a string, or an InputSource to
     read from.  The default implementation returns 'systemId'.


File: python.info,  Node: ErrorHandler Objects,  Next: LexicalHandler Objects,  Prev: EntityResolver Objects,  Up: xml sax handler — Base classes for SAX handlers

5.21.10.4 ErrorHandler Objects
..............................

Objects with this interface are used to receive error and warning
information from the *note XMLReader: 3db7.  If you create an object
that implements this interface, then register the object with your *note
XMLReader: 3db7, the parser will call the methods in your object to
report all warnings and errors.  There are three levels of errors
available: warnings, (possibly) recoverable errors, and unrecoverable
errors.  All methods take a *note SAXParseException: 3dc3. as the only
parameter.  Errors and warnings may be converted to an exception by
raising the passed-in exception object.

 -- Metodo: ErrorHandler.error (exception)

     Called when the parser encounters a recoverable error.  If this
     method does not raise an exception, parsing may continue, but
     further document information should not be expected by the
     application.  Allowing the parser to continue may allow additional
     errors to be discovered in the input document.

 -- Metodo: ErrorHandler.fatalError (exception)

     Called when the parser encounters an error it cannot recover from;
     parsing is expected to terminate when this method returns.

 -- Metodo: ErrorHandler.warning (exception)

     Called when the parser presents minor warning information to the
     application.  Parsing is expected to continue when this method
     returns, and document information will continue to be passed to the
     application.  Raising an exception in this method will cause
     parsing to end.


File: python.info,  Node: LexicalHandler Objects,  Prev: ErrorHandler Objects,  Up: xml sax handler — Base classes for SAX handlers

5.21.10.5 LexicalHandler Objects
................................

Optional SAX2 handler for lexical events.

This handler is used to obtain lexical information about an XML
document.  Lexical information includes information describing the
document encoding used and XML comments embedded in the document, as
well as section boundaries for the DTD and for any CDATA sections.  The
lexical handlers are used in the same manner as content handlers.

Set the LexicalHandler of an XMLReader by using the setProperty method
with the property identifier
‘'http://xml.org/sax/properties/lexical-handler'’.

 -- Metodo: LexicalHandler.comment (content)

     Reports a comment anywhere in the document (including the DTD and
     outside the document element).

 -- Metodo: LexicalHandler.startDTD (name, public_id, system_id)

     Reports the start of the DTD declarations if the document has an
     associated DTD.

 -- Metodo: LexicalHandler.endDTD ()

     Reports the end of DTD declaration.

 -- Metodo: LexicalHandler.startCDATA ()

     Reports the start of a CDATA marked section.

     The contents of the CDATA marked section will be reported through
     the characters handler.

 -- Metodo: LexicalHandler.endCDATA ()

     Reports the end of a CDATA marked section.


File: python.info,  Node: xml sax saxutils — SAX Utilities,  Next: xml sax xmlreader — Interface for XML parsers,  Prev: xml sax handler — Base classes for SAX handlers,  Up: Structured Markup Processing Tools

5.21.11 ‘xml.sax.saxutils’ — SAX Utilities
------------------------------------------

'Source code:' Lib/xml/sax/saxutils.py(1)

__________________________________________________________________

The module *note xml.sax.saxutils: 131. contains a number of classes and
functions that are commonly useful when creating SAX applications,
either in direct use, or as base classes.

 -- Funzione: xml.sax.saxutils.escape (data, entities={})

     Escape ‘'&'’, ‘'<'’, and ‘'>'’ in a string of data.

     You can escape other strings of data by passing a dictionary as the
     optional 'entities' parameter.  The keys and values must all be
     strings; each key will be replaced with its corresponding value.
     The characters ‘'&'’, ‘'<'’ and ‘'>'’ are always escaped, even if
     'entities' is provided.

          Nota: This function should only be used to escape characters
          that can’t be used directly in XML. Do not use this function
          as a general string translation function.

 -- Funzione: xml.sax.saxutils.unescape (data, entities={})

     Unescape ‘'&amp;'’, ‘'&lt;'’, and ‘'&gt;'’ in a string of data.

     You can unescape other strings of data by passing a dictionary as
     the optional 'entities' parameter.  The keys and values must all be
     strings; each key will be replaced with its corresponding value.
     ‘'&amp;'’, ‘'&lt;'’, and ‘'&gt;'’ are always unescaped, even if
     'entities' is provided.

 -- Funzione: xml.sax.saxutils.quoteattr (data, entities={})

     Similar to *note escape(): 3e00, but also prepares 'data' to be
     used as an attribute value.  The return value is a quoted version
     of 'data' with any additional required replacements.  *note
     quoteattr(): 3e02. will select a quote character based on the
     content of 'data', attempting to avoid encoding any quote
     characters in the string.  If both single- and double-quote
     characters are already in 'data', the double-quote characters will
     be encoded and 'data' will be wrapped in double-quotes.  The
     resulting string can be used directly as an attribute value:

          >>> print("<element attr=%s>" % quoteattr("ab ' cd \" ef"))
          <element attr="ab ' cd &quot; ef">

     This function is useful when generating attribute values for HTML
     or any SGML using the reference concrete syntax.

 -- Classe: xml.sax.saxutils.XMLGenerator (out=None,
          encoding='iso-8859-1', short_empty_elements=False)

     This class implements the *note ContentHandler: 3db4. interface by
     writing SAX events back into an XML document.  In other words,
     using an *note XMLGenerator: 3e03. as the content handler will
     reproduce the original document being parsed.  'out' should be a
     file-like object which will default to 'sys.stdout'.  'encoding' is
     the encoding of the output stream which defaults to ‘'iso-8859-1'’.
     'short_empty_elements' controls the formatting of elements that
     contain no content: if ‘False’ (the default) they are emitted as a
     pair of start/end tags, if set to ‘True’ they are emitted as a
     single self-closed tag.

     Cambiato nella versione 3.2: Added the 'short_empty_elements'
     parameter.

 -- Classe: xml.sax.saxutils.XMLFilterBase (base)

     This class is designed to sit between an *note XMLReader: 3db7. and
     the client application’s event handlers.  By default, it does
     nothing but pass requests up to the reader and events on to the
     handlers unmodified, but subclasses can override specific methods
     to modify the event stream or the configuration requests as they
     pass through.

 -- Funzione: xml.sax.saxutils.prepare_input_source (source, base='')

     This function takes an input source and an optional base URL and
     returns a fully resolved *note InputSource: 109d. object ready for
     reading.  The input source can be given as a string, a file-like
     object, or an *note InputSource: 109d. object; parsers will use
     this function to implement the polymorphic 'source' argument to
     their *note parse(): 3e06. method.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/xml/sax/saxutils.py


File: python.info,  Node: xml sax xmlreader — Interface for XML parsers,  Next: xml parsers expat — Fast XML parsing using Expat,  Prev: xml sax saxutils — SAX Utilities,  Up: Structured Markup Processing Tools

5.21.12 ‘xml.sax.xmlreader’ — Interface for XML parsers
-------------------------------------------------------

'Source code:' Lib/xml/sax/xmlreader.py(1)

__________________________________________________________________

SAX parsers implement the *note XMLReader: 3db7. interface.  They are
implemented in a Python module, which must provide a function
‘create_parser()’.  This function is invoked by *note
xml.sax.make_parser(): 1e04. with no arguments to create a new parser
object.

 -- Classe: xml.sax.xmlreader.XMLReader

     Base class which can be inherited by SAX parsers.

 -- Classe: xml.sax.xmlreader.IncrementalParser

     In some cases, it is desirable not to parse an input source at
     once, but to feed chunks of the document as they get available.
     Note that the reader will normally not read the entire file, but
     read it in chunks as well; still ‘parse()’ won’t return until the
     entire document is processed.  So these interfaces should be used
     if the blocking behaviour of ‘parse()’ is not desirable.

     When the parser is instantiated it is ready to begin accepting data
     from the feed method immediately.  After parsing has been finished
     with a call to close the reset method must be called to make the
     parser ready to accept new data, either from feed or using the
     parse method.

     Note that these methods must 'not' be called during parsing, that
     is, after parse has been called and before it returns.

     By default, the class also implements the parse method of the
     XMLReader interface using the feed, close and reset methods of the
     IncrementalParser interface as a convenience to SAX 2.0 driver
     writers.

 -- Classe: xml.sax.xmlreader.Locator

     Interface for associating a SAX event with a document location.  A
     locator object will return valid results only during calls to
     DocumentHandler methods; at any other time, the results are
     unpredictable.  If information is not available, methods may return
     ‘None’.

 -- Classe: xml.sax.xmlreader.InputSource (system_id=None)

     Encapsulation of the information needed by the *note XMLReader:
     3db7. to read entities.

     This class may include information about the public identifier,
     system identifier, byte stream (possibly with character encoding
     information) and/or the character stream of an entity.

     Applications will create objects of this class for use in the *note
     XMLReader.parse(): 3e06. method and for returning from
     EntityResolver.resolveEntity.

     An *note InputSource: 109d. belongs to the application, the *note
     XMLReader: 3db7. is not allowed to modify *note InputSource: 109d.
     objects passed to it from the application, although it may make
     copies and modify those.

 -- Classe: xml.sax.xmlreader.AttributesImpl (attrs)

     This is an implementation of the ‘Attributes’ interface (see
     section *note The Attributes Interface: 3de3.).  This is a
     dictionary-like object which represents the element attributes in a
     ‘startElement()’ call.  In addition to the most useful dictionary
     operations, it supports a number of other methods as described by
     the interface.  Objects of this class should be instantiated by
     readers; 'attrs' must be a dictionary-like object containing a
     mapping from attribute names to attribute values.

 -- Classe: xml.sax.xmlreader.AttributesNSImpl (attrs, qnames)

     Namespace-aware variant of *note AttributesImpl: 3e0b, which will
     be passed to ‘startElementNS()’.  It is derived from *note
     AttributesImpl: 3e0b, but understands attribute names as two-tuples
     of 'namespaceURI' and 'localname'.  In addition, it provides a
     number of methods expecting qualified names as they appear in the
     original document.  This class implements the ‘AttributesNS’
     interface (see section *note The AttributesNS Interface: 3de5.).

* Menu:

* XMLReader Objects::
* IncrementalParser Objects::
* Locator Objects::
* InputSource Objects::
* The Attributes Interface::
* The AttributesNS Interface::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/xml/sax/xmlreader.py


File: python.info,  Node: XMLReader Objects,  Next: IncrementalParser Objects,  Up: xml sax xmlreader — Interface for XML parsers

5.21.12.1 XMLReader Objects
...........................

The *note XMLReader: 3db7. interface supports the following methods:

 -- Metodo: XMLReader.parse (source)

     Process an input source, producing SAX events.  The 'source' object
     can be a system identifier (a string identifying the input source –
     typically a file name or a URL), a *note pathlib.Path: 266. or
     *note path-like: 5a1. object, or an *note InputSource: 109d.
     object.  When *note parse(): 3e06. returns, the input is completely
     processed, and the parser object can be discarded or reset.

     Cambiato nella versione 3.5: Added support of character streams.

     Cambiato nella versione 3.8: Added support of path-like objects.

 -- Metodo: XMLReader.getContentHandler ()

     Return the current *note ContentHandler: 3db4.

 -- Metodo: XMLReader.setContentHandler (handler)

     Set the current *note ContentHandler: 3db4.  If no *note
     ContentHandler: 3db4. is set, content events will be discarded.

 -- Metodo: XMLReader.getDTDHandler ()

     Return the current *note DTDHandler: 3dcf.

 -- Metodo: XMLReader.setDTDHandler (handler)

     Set the current *note DTDHandler: 3dcf.  If no *note DTDHandler:
     3dcf. is set, DTD events will be discarded.

 -- Metodo: XMLReader.getEntityResolver ()

     Return the current *note EntityResolver: 3dd0.

 -- Metodo: XMLReader.setEntityResolver (handler)

     Set the current *note EntityResolver: 3dd0.  If no *note
     EntityResolver: 3dd0. is set, attempts to resolve an external
     entity will result in opening the system identifier for the entity,
     and fail if it is not available.

 -- Metodo: XMLReader.getErrorHandler ()

     Return the current *note ErrorHandler: 3dc2.

 -- Metodo: XMLReader.setErrorHandler (handler)

     Set the current error handler.  If no *note ErrorHandler: 3dc2. is
     set, errors will be raised as exceptions, and warnings will be
     printed.

 -- Metodo: XMLReader.setLocale (locale)

     Allow an application to set the locale for errors and warnings.

     SAX parsers are not required to provide localization for errors and
     warnings; if they cannot support the requested locale, however,
     they must raise a SAX exception.  Applications may request a locale
     change in the middle of a parse.

 -- Metodo: XMLReader.getFeature (featurename)

     Return the current setting for feature 'featurename'.  If the
     feature is not recognized, ‘SAXNotRecognizedException’ is raised.
     The well-known featurenames are listed in the module *note
     xml.sax.handler: 130.

 -- Metodo: XMLReader.setFeature (featurename, value)

     Set the 'featurename' to 'value'.  If the feature is not
     recognized, ‘SAXNotRecognizedException’ is raised.  If the feature
     or its setting is not supported by the parser,
     'SAXNotSupportedException' is raised.

 -- Metodo: XMLReader.getProperty (propertyname)

     Return the current setting for property 'propertyname'.  If the
     property is not recognized, a ‘SAXNotRecognizedException’ is
     raised.  The well-known propertynames are listed in the module
     *note xml.sax.handler: 130.

 -- Metodo: XMLReader.setProperty (propertyname, value)

     Set the 'propertyname' to 'value'.  If the property is not
     recognized, ‘SAXNotRecognizedException’ is raised.  If the property
     or its setting is not supported by the parser,
     'SAXNotSupportedException' is raised.


File: python.info,  Node: IncrementalParser Objects,  Next: Locator Objects,  Prev: XMLReader Objects,  Up: xml sax xmlreader — Interface for XML parsers

5.21.12.2 IncrementalParser Objects
...................................

Instances of *note IncrementalParser: 3e0a. offer the following
additional methods:

 -- Metodo: IncrementalParser.feed (data)

     Process a chunk of 'data'.

 -- Metodo: IncrementalParser.close ()

     Assume the end of the document.  That will check well-formedness
     conditions that can be checked only at the end, invoke handlers,
     and may clean up resources allocated during parsing.

 -- Metodo: IncrementalParser.reset ()

     This method is called after close has been called to reset the
     parser so that it is ready to parse new documents.  The results of
     calling parse or feed after close without calling reset are
     undefined.


File: python.info,  Node: Locator Objects,  Next: InputSource Objects,  Prev: IncrementalParser Objects,  Up: xml sax xmlreader — Interface for XML parsers

5.21.12.3 Locator Objects
.........................

Instances of *note Locator: 3dc4. provide these methods:

 -- Metodo: Locator.getColumnNumber ()

     Return the column number where the current event begins.

 -- Metodo: Locator.getLineNumber ()

     Return the line number where the current event begins.

 -- Metodo: Locator.getPublicId ()

     Return the public identifier for the current event.

 -- Metodo: Locator.getSystemId ()

     Return the system identifier for the current event.


File: python.info,  Node: InputSource Objects,  Next: The Attributes Interface,  Prev: Locator Objects,  Up: xml sax xmlreader — Interface for XML parsers

5.21.12.4 InputSource Objects
.............................

 -- Metodo: InputSource.setPublicId (id)

     Sets the public identifier of this *note InputSource: 109d.

 -- Metodo: InputSource.getPublicId ()

     Returns the public identifier of this *note InputSource: 109d.

 -- Metodo: InputSource.setSystemId (id)

     Sets the system identifier of this *note InputSource: 109d.

 -- Metodo: InputSource.getSystemId ()

     Returns the system identifier of this *note InputSource: 109d.

 -- Metodo: InputSource.setEncoding (encoding)

     Sets the character encoding of this *note InputSource: 109d.

     The encoding must be a string acceptable for an XML encoding
     declaration (see section 4.3.3 of the XML recommendation).

     The encoding attribute of the *note InputSource: 109d. is ignored
     if the *note InputSource: 109d. also contains a character stream.

 -- Metodo: InputSource.getEncoding ()

     Get the character encoding of this InputSource.

 -- Metodo: InputSource.setByteStream (bytefile)

     Set the byte stream (a *note binary file: 2058.) for this input
     source.

     The SAX parser will ignore this if there is also a character stream
     specified, but it will use a byte stream in preference to opening a
     URI connection itself.

     If the application knows the character encoding of the byte stream,
     it should set it with the setEncoding method.

 -- Metodo: InputSource.getByteStream ()

     Get the byte stream for this input source.

     The getEncoding method will return the character encoding for this
     byte stream, or ‘None’ if unknown.

 -- Metodo: InputSource.setCharacterStream (charfile)

     Set the character stream (a *note text file: 2057.) for this input
     source.

     If there is a character stream specified, the SAX parser will
     ignore any byte stream and will not attempt to open a URI
     connection to the system identifier.

 -- Metodo: InputSource.getCharacterStream ()

     Get the character stream for this input source.


File: python.info,  Node: The Attributes Interface,  Next: The AttributesNS Interface,  Prev: InputSource Objects,  Up: xml sax xmlreader — Interface for XML parsers

5.21.12.5 The ‘Attributes’ Interface
....................................

‘Attributes’ objects implement a portion of the *note mapping protocol:
13c3, including the methods ‘copy()’, ‘get()’, *note __contains__():
15c1, ‘items()’, ‘keys()’, and ‘values()’.  The following methods are
also provided:

 -- Metodo: Attributes.getLength ()

     Return the number of attributes.

 -- Metodo: Attributes.getNames ()

     Return the names of the attributes.

 -- Metodo: Attributes.getType (name)

     Returns the type of the attribute 'name', which is normally
     ‘'CDATA'’.

 -- Metodo: Attributes.getValue (name)

     Return the value of attribute 'name'.


File: python.info,  Node: The AttributesNS Interface,  Prev: The Attributes Interface,  Up: xml sax xmlreader — Interface for XML parsers

5.21.12.6 The ‘AttributesNS’ Interface
......................................

This interface is a subtype of the ‘Attributes’ interface (see section
*note The Attributes Interface: 3de3.).  All methods supported by that
interface are also available on ‘AttributesNS’ objects.

The following methods are also available:

 -- Metodo: AttributesNS.getValueByQName (name)

     Return the value for a qualified name.

 -- Metodo: AttributesNS.getNameByQName (name)

     Return the ‘(namespace, localname)’ pair for a qualified 'name'.

 -- Metodo: AttributesNS.getQNameByName (name)

     Return the qualified name for a ‘(namespace, localname)’ pair.

 -- Metodo: AttributesNS.getQNames ()

     Return the qualified names of all attributes.


File: python.info,  Node: xml parsers expat — Fast XML parsing using Expat,  Prev: xml sax xmlreader — Interface for XML parsers,  Up: Structured Markup Processing Tools

5.21.13 ‘xml.parsers.expat’ — Fast XML parsing using Expat
----------------------------------------------------------

__________________________________________________________________

     Nota: If you need to parse untrusted or unauthenticated data, see
     *note XML security: 3cd0.

The *note xml.parsers.expat: 12c. module is a Python interface to the
Expat non-validating XML parser.  The module provides a single extension
type, ‘xmlparser’, that represents the current state of an XML parser.
After an ‘xmlparser’ object has been created, various attributes of the
object can be set to handler functions.  When an XML document is then
fed to the parser, the handler functions are called for the character
data and markup in the XML document.

This module uses the ‘pyexpat’ module to provide access to the Expat
parser.  Direct use of the ‘pyexpat’ module is deprecated.

This module provides one exception and one type object:

 -- Eccezione: xml.parsers.expat.ExpatError

     The exception raised when Expat reports an error.  See section
     *note ExpatError Exceptions: 3e3f. for more information on
     interpreting Expat errors.

 -- Eccezione: xml.parsers.expat.error

     Alias for *note ExpatError: 1480.

 -- Dati: xml.parsers.expat.XMLParserType

     The type of the return values from the *note ParserCreate(): 3e42.
     function.

The *note xml.parsers.expat: 12c. module contains two functions:

 -- Funzione: xml.parsers.expat.ErrorString (errno)

     Returns an explanatory string for a given error number 'errno'.

 -- Funzione: xml.parsers.expat.ParserCreate (encoding=None,
          namespace_separator=None)

     Creates and returns a new ‘xmlparser’ object.  'encoding', if
     specified, must be a string naming the encoding used by the XML
     data.  Expat doesn’t support as many encodings as Python does, and
     its repertoire of encodings can’t be extended; it supports UTF-8,
     UTF-16, ISO-8859-1 (Latin1), and ASCII. If 'encoding' (1) is given
     it will override the implicit or explicit encoding of the document.
     Parsers created through ‘ParserCreate()’ are called «root» parsers,
     in the sense that they do not have any parent parser attached.
     Non-root parsers are created by *note
     parser.ExternalEntityParserCreate: 17d6.

     Expat can optionally do XML namespace processing for you, enabled
     by providing a value for 'namespace_separator'.  The value must be
     a one-character string; a *note ValueError: 2ec. will be raised if
     the string has an illegal length (‘None’ is considered the same as
     omission).  When namespace processing is enabled, element type
     names and attribute names that belong to a namespace will be
     expanded.  The element name passed to the element handlers
     ‘StartElementHandler’ and ‘EndElementHandler’ will be the
     concatenation of the namespace URI, the namespace separator
     character, and the local part of the name.  If the namespace
     separator is a zero byte (‘chr(0)’) then the namespace URI and the
     local part will be concatenated without any separator.

     For example, if 'namespace_separator' is set to a space character
     (‘' '’) and the following document is parsed:

          <?xml version="1.0"?>
          <root xmlns    = "http://default-namespace.org/"
                xmlns:py = "http://www.python.org/ns/">
            <py:elem1 />
            <elem2 xmlns="" />
          </root>

     ‘StartElementHandler’ will receive the following strings for each
     element:

          http://default-namespace.org/ root
          http://www.python.org/ns/ elem1
          elem2

     Due to limitations in the ‘Expat’ library used by ‘pyexpat’, the
     ‘xmlparser’ instance returned can only be used to parse a single
     XML document.  Call ‘ParserCreate’ for each document to provide
     unique parser instances.

Vedi anche
..........

The Expat XML Parser(2)

     Home page of the Expat project.

* Menu:

* XMLParser Objects: XMLParser Objects<2>.
* ExpatError Exceptions::
* Example: Example<10>.
* Content Model Descriptions::
* Expat error constants::

   ---------- Footnotes ----------

   (1) The encoding string included in XML output should conform to the
appropriate standards.  For example, «UTF-8» is valid, but «UTF8» is
not.  See
‘https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl’ and
‘https://www.iana.org/assignments/character-sets/character-sets.xhtml’.

   (2) http://www.libexpat.org/


File: python.info,  Node: XMLParser Objects<2>,  Next: ExpatError Exceptions,  Up: xml parsers expat — Fast XML parsing using Expat

5.21.13.1 XMLParser Objects
...........................

‘xmlparser’ objects have the following methods:

 -- Metodo: xmlparser.Parse (data[, isfinal])

     Parses the contents of the string 'data', calling the appropriate
     handler functions to process the parsed data.  'isfinal' must be
     true on the final call to this method; it allows the parsing of a
     single file in fragments, not the submission of multiple files.
     'data' can be the empty string at any time.

 -- Metodo: xmlparser.ParseFile (file)

     Parse XML data reading from the object 'file'.  'file' only needs
     to provide the ‘read(nbytes)’ method, returning the empty string
     when there’s no more data.

 -- Metodo: xmlparser.SetBase (base)

     Sets the base to be used for resolving relative URIs in system
     identifiers in declarations.  Resolving relative identifiers is
     left to the application: this value will be passed through as the
     'base' argument to the *note ExternalEntityRefHandler(): 3e49,
     *note NotationDeclHandler(): 3e4a, and *note
     UnparsedEntityDeclHandler(): 3e4b. functions.

 -- Metodo: xmlparser.GetBase ()

     Returns a string containing the base set by a previous call to
     *note SetBase(): 3e48, or ‘None’ if *note SetBase(): 3e48. hasn’t
     been called.

 -- Metodo: xmlparser.GetInputContext ()

     Returns the input data that generated the current event as a
     string.  The data is in the encoding of the entity which contains
     the text.  When called while an event handler is not active, the
     return value is ‘None’.

 -- Metodo: xmlparser.ExternalEntityParserCreate (context[, encoding])

     Create a «child» parser which can be used to parse an external
     parsed entity referred to by content parsed by the parent parser.
     The 'context' parameter should be the string passed to the *note
     ExternalEntityRefHandler(): 3e49. handler function, described
     below.  The child parser is created with the *note
     ordered_attributes: 3e4e. and *note specified_attributes: 3e4f. set
     to the values of this parser.

 -- Metodo: xmlparser.SetParamEntityParsing (flag)

     Control parsing of parameter entities (including the external DTD
     subset).  Possible 'flag' values are
     ‘XML_PARAM_ENTITY_PARSING_NEVER’,
     ‘XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE’ and
     ‘XML_PARAM_ENTITY_PARSING_ALWAYS’.  Return true if setting the flag
     was successful.

 -- Metodo: xmlparser.UseForeignDTD ([flag])

     Calling this with a true value for 'flag' (the default) will cause
     Expat to call the *note ExternalEntityRefHandler: 3e49. with *note
     None: 886. for all arguments to allow an alternate DTD to be
     loaded.  If the document does not contain a document type
     declaration, the *note ExternalEntityRefHandler: 3e49. will still
     be called, but the *note StartDoctypeDeclHandler: 3e52. and *note
     EndDoctypeDeclHandler: 3e53. will not be called.

     Passing a false value for 'flag' will cancel a previous call that
     passed a true value, but otherwise has no effect.

     This method can only be called before the *note Parse(): 3e46. or
     *note ParseFile(): 3e47. methods are called; calling it after
     either of those have been called causes *note ExpatError: 1480. to
     be raised with the *note code: 1b. attribute set to
     ‘errors.codes[errors.XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING]’.

 -- Metodo: xmlparser.SetReparseDeferralEnabled (enabled)

          Avvertimento: Calling ‘SetReparseDeferralEnabled(False)’ has
          security implications, as detailed below; please make sure to
          understand these consequences prior to using the
          ‘SetReparseDeferralEnabled’ method.

     Expat 2.6.0 introduced a security mechanism called «reparse
     deferral» where instead of causing denial of service through
     quadratic runtime from reparsing large tokens, reparsing of
     unfinished tokens is now delayed by default until a sufficient
     amount of input is reached.  Due to this delay, registered handlers
     may — depending of the sizing of input chunks pushed to Expat — no
     longer be called right after pushing new input to the parser.
     Where immediate feedback and taking over responsibility of
     protecting against denial of service from large tokens are both
     wanted, calling ‘SetReparseDeferralEnabled(False)’ disables reparse
     deferral for the current Expat parser instance, temporarily or
     altogether.  Calling ‘SetReparseDeferralEnabled(True)’ allows
     re-enabling reparse deferral.

     Note that *note SetReparseDeferralEnabled(): 579. has been
     backported to some prior releases of CPython as a security fix.
     Check for availability of *note SetReparseDeferralEnabled(): 579.
     using *note hasattr(): 6fa. if used in code running across a
     variety of Python versions.

     Added in version 3.13.

 -- Metodo: xmlparser.GetReparseDeferralEnabled ()

     Returns whether reparse deferral is currently enabled for the given
     Expat parser instance.

     Added in version 3.13.

‘xmlparser’ objects have the following methods to mitigate some common
XML vulnerabilities.

 -- Metodo: xmlparser.SetAllocTrackerActivationThreshold (threshold, /)

     Sets the number of allocated bytes of dynamic memory needed to
     activate protection against disproportionate use of RAM.

     By default, parser objects have an allocation activation threshold
     of 64 MiB, or equivalently 67,108,864 bytes.

     An *note ExpatError: 1480. is raised if this method is called on a
     *note non-root: 3e44. parser.  The corresponding *note lineno:
     3e54. and *note offset: 3e55. should not be used as they may have
     no special meaning.

     Added in version 3.14.1.

 -- Metodo: xmlparser.SetAllocTrackerMaximumAmplification (max_factor,
          /)

     Sets the maximum amplification factor between direct input and
     bytes of dynamic memory allocated.

     The amplification factor is calculated as ‘allocated / direct’
     while parsing, where ‘direct’ is the number of bytes read from the
     primary document in parsing and ‘allocated’ is the number of bytes
     of dynamic memory allocated in the parser hierarchy.

     The 'max_factor' value must be a non-NaN *note float: 196. value
     greater than or equal to 1.0.  Amplification factors greater than
     100.0 can be observed near the start of parsing even with benign
     files in practice.  In particular, the activation threshold should
     be carefully chosen to avoid false positives.

     By default, parser objects have a maximum amplification factor of
     100.0.

     An *note ExpatError: 1480. is raised if this method is called on a
     *note non-root: 3e44. parser or if 'max_factor' is outside the
     valid range.  The corresponding *note lineno: 3e54. and *note
     offset: 3e55. should not be used as they may have no special
     meaning.

          Nota: The maximum amplification factor is only considered if
          the threshold that can be adjusted by *note
          SetAllocTrackerActivationThreshold(): 17a1. is exceeded.

     Added in version 3.14.1.

‘xmlparser’ objects have the following attributes:

 -- Attributo: xmlparser.buffer_size

     The size of the buffer used when *note buffer_text: 16c9. is true.
     A new buffer size can be set by assigning a new integer value to
     this attribute.  When the size is changed, the buffer will be
     flushed.

 -- Attributo: xmlparser.buffer_text

     Setting this to true causes the ‘xmlparser’ object to buffer
     textual content returned by Expat to avoid multiple calls to the
     *note CharacterDataHandler(): 3e57. callback whenever possible.
     This can improve performance substantially since Expat normally
     breaks character data into chunks at every line ending.  This
     attribute is false by default, and may be changed at any time.
     Note that when it is false, data that does not contain newlines may
     be chunked too.

 -- Attributo: xmlparser.buffer_used

     If *note buffer_text: 16c9. is enabled, the number of bytes stored
     in the buffer.  These bytes represent UTF-8 encoded text.  This
     attribute has no meaningful interpretation when *note buffer_text:
     16c9. is false.

 -- Attributo: xmlparser.ordered_attributes

     Setting this attribute to a non-zero integer causes the attributes
     to be reported as a list rather than a dictionary.  The attributes
     are presented in the order found in the document text.  For each
     attribute, two list entries are presented: the attribute name and
     the attribute value.  (Older versions of this module also used this
     format.)  By default, this attribute is false; it may be changed at
     any time.

 -- Attributo: xmlparser.specified_attributes

     If set to a non-zero integer, the parser will report only those
     attributes which were specified in the document instance and not
     those which were derived from attribute declarations.  Applications
     which set this need to be especially careful to use what additional
     information is available from the declarations as needed to comply
     with the standards for the behavior of XML processors.  By default,
     this attribute is false; it may be changed at any time.

The following attributes contain values relating to the most recent
error encountered by an ‘xmlparser’ object, and will only have correct
values once a call to ‘Parse()’ or ‘ParseFile()’ has raised an *note
xml.parsers.expat.ExpatError: 1480. exception.

 -- Attributo: xmlparser.ErrorByteIndex

     Byte index at which an error occurred.

 -- Attributo: xmlparser.ErrorCode

     Numeric code specifying the problem.  This value can be passed to
     the *note ErrorString(): 3e43. function, or compared to one of the
     constants defined in the ‘errors’ object.

 -- Attributo: xmlparser.ErrorColumnNumber

     Column number at which an error occurred.

 -- Attributo: xmlparser.ErrorLineNumber

     Line number at which an error occurred.

The following attributes contain values relating to the current parse
location in an ‘xmlparser’ object.  During a callback reporting a parse
event they indicate the location of the first of the sequence of
characters that generated the event.  When called outside of a callback,
the position indicated will be just past the last parse event
(regardless of whether there was an associated callback).

 -- Attributo: xmlparser.CurrentByteIndex

     Current byte index in the parser input.

 -- Attributo: xmlparser.CurrentColumnNumber

     Current column number in the parser input.

 -- Attributo: xmlparser.CurrentLineNumber

     Current line number in the parser input.

Here is the list of handlers that can be set.  To set a handler on an
‘xmlparser’ object 'o', use ‘o.handlername = func’.  'handlername' must
be taken from the following list, and 'func' must be a callable object
accepting the correct number of arguments.  The arguments are all
strings, unless otherwise stated.

 -- Metodo: xmlparser.XmlDeclHandler (version, encoding, standalone)

     Called when the XML declaration is parsed.  The XML declaration is
     the (optional) declaration of the applicable version of the XML
     recommendation, the encoding of the document text, and an optional
     «standalone» declaration.  'version' and 'encoding' will be
     strings, and 'standalone' will be ‘1’ if the document is declared
     standalone, ‘0’ if it is declared not to be standalone, or ‘-1’ if
     the standalone clause was omitted.  This is only available with
     Expat version 1.95.0 or newer.

 -- Metodo: xmlparser.StartDoctypeDeclHandler (doctypeName, systemId,
          publicId, has_internal_subset)

     Called when Expat begins parsing the document type declaration
     (‘<!DOCTYPE ...’).  The 'doctypeName' is provided exactly as
     presented.  The 'systemId' and 'publicId' parameters give the
     system and public identifiers if specified, or ‘None’ if omitted.
     'has_internal_subset' will be true if the document contains and
     internal document declaration subset.  This requires Expat version
     1.2 or newer.

 -- Metodo: xmlparser.EndDoctypeDeclHandler ()

     Called when Expat is done parsing the document type declaration.
     This requires Expat version 1.2 or newer.

 -- Metodo: xmlparser.ElementDeclHandler (name, model)

     Called once for each element type declaration.  'name' is the name
     of the element type, and 'model' is a representation of the content
     model.

 -- Metodo: xmlparser.AttlistDeclHandler (elname, attname, type,
          default, required)

     Called for each declared attribute for an element type.  If an
     attribute list declaration declares three attributes, this handler
     is called three times, once for each attribute.  'elname' is the
     name of the element to which the declaration applies and 'attname'
     is the name of the attribute declared.  The attribute type is a
     string passed as 'type'; the possible values are ‘'CDATA'’, ‘'ID'’,
     ‘'IDREF'’, … 'default' gives the default value for the attribute
     used when the attribute is not specified by the document instance,
     or ‘None’ if there is no default value (‘#IMPLIED’ values).  If the
     attribute is required to be given in the document instance,
     'required' will be true.  This requires Expat version 1.95.0 or
     newer.

 -- Metodo: xmlparser.StartElementHandler (name, attributes)

     Called for the start of every element.  'name' is a string
     containing the element name, and 'attributes' is the element
     attributes.  If *note ordered_attributes: 3e4e. is true, this is a
     list (see *note ordered_attributes: 3e4e. for a full description).
     Otherwise it’s a dictionary mapping names to values.

 -- Metodo: xmlparser.EndElementHandler (name)

     Called for the end of every element.

 -- Metodo: xmlparser.ProcessingInstructionHandler (target, data)

     Called for every processing instruction.

 -- Metodo: xmlparser.CharacterDataHandler (data)

     Called for character data.  This will be called for normal
     character data, CDATA marked content, and ignorable whitespace.
     Applications which must distinguish these cases can use the *note
     StartCdataSectionHandler: 3e65, *note EndCdataSectionHandler: 3e66,
     and *note ElementDeclHandler: 179c. callbacks to collect the
     required information.  Note that the character data may be chunked
     even if it is short and so you may receive more than one call to
     *note CharacterDataHandler(): 3e57.  Set the *note buffer_text:
     16c9. instance attribute to ‘True’ to avoid that.

 -- Metodo: xmlparser.UnparsedEntityDeclHandler (entityName, base,
          systemId, publicId, notationName)

     Called for unparsed (NDATA) entity declarations.  This is only
     present for version 1.2 of the Expat library; for more recent
     versions, use *note EntityDeclHandler: 3e67. instead.  (The
     underlying function in the Expat library has been declared
     obsolete.)

 -- Metodo: xmlparser.EntityDeclHandler (entityName,
          is_parameter_entity, value, base, systemId, publicId,
          notationName)

     Called for all entity declarations.  For parameter and internal
     entities, 'value' will be a string giving the declared contents of
     the entity; this will be ‘None’ for external entities.  The
     'notationName' parameter will be ‘None’ for parsed entities, and
     the name of the notation for unparsed entities.
     'is_parameter_entity' will be true if the entity is a parameter
     entity or false for general entities (most applications only need
     to be concerned with general entities).  This is only available
     starting with version 1.95.0 of the Expat library.

 -- Metodo: xmlparser.NotationDeclHandler (notationName, base, systemId,
          publicId)

     Called for notation declarations.  'notationName', 'base', and
     'systemId', and 'publicId' are strings if given.  If the public
     identifier is omitted, 'publicId' will be ‘None’.

 -- Metodo: xmlparser.StartNamespaceDeclHandler (prefix, uri)

     Called when an element contains a namespace declaration.  Namespace
     declarations are processed before the *note StartElementHandler:
     3e62. is called for the element on which declarations are placed.

 -- Metodo: xmlparser.EndNamespaceDeclHandler (prefix)

     Called when the closing tag is reached for an element that
     contained a namespace declaration.  This is called once for each
     namespace declaration on the element in the reverse of the order
     for which the *note StartNamespaceDeclHandler: 3e68. was called to
     indicate the start of each namespace declaration’s scope.  Calls to
     this handler are made after the corresponding *note
     EndElementHandler: 3e63. for the end of the element.

 -- Metodo: xmlparser.CommentHandler (data)

     Called for comments.  'data' is the text of the comment, excluding
     the leading ‘'<!-’‘-'’ and trailing ‘'-’‘->'’.

 -- Metodo: xmlparser.StartCdataSectionHandler ()

     Called at the start of a CDATA section.  This and *note
     EndCdataSectionHandler: 3e66. are needed to be able to identify the
     syntactical start and end for CDATA sections.

 -- Metodo: xmlparser.EndCdataSectionHandler ()

     Called at the end of a CDATA section.

 -- Metodo: xmlparser.DefaultHandler (data)

     Called for any characters in the XML document for which no
     applicable handler has been specified.  This means characters that
     are part of a construct which could be reported, but for which no
     handler has been supplied.

 -- Metodo: xmlparser.DefaultHandlerExpand (data)

     This is the same as the *note DefaultHandler(): 3e6b, but doesn’t
     inhibit expansion of internal entities.  The entity reference will
     not be passed to the default handler.

 -- Metodo: xmlparser.NotStandaloneHandler ()

     Called if the XML document hasn’t been declared as being a
     standalone document.  This happens when there is an external subset
     or a reference to a parameter entity, but the XML declaration does
     not set standalone to ‘yes’ in an XML declaration.  If this handler
     returns ‘0’, then the parser will raise an
     ‘XML_ERROR_NOT_STANDALONE’ error.  If this handler is not set, no
     exception is raised by the parser for this condition.

 -- Metodo: xmlparser.ExternalEntityRefHandler (context, base, systemId,
          publicId)

          Avvertimento: Implementing a handler that accesses local files
          and/or the network may create a vulnerability to external
          entity attacks(1) if ‘xmlparser’ is used with user-provided
          XML content.  Please reflect on your threat model(2) before
          implementing this handler.

     Called for references to external entities.  'base' is the current
     base, as set by a previous call to *note SetBase(): 3e48.  The
     public and system identifiers, 'systemId' and 'publicId', are
     strings if given; if the public identifier is not given, 'publicId'
     will be ‘None’.  The 'context' value is opaque and should only be
     used as described below.

     For external entities to be parsed, this handler must be
     implemented.  It is responsible for creating the sub-parser using
     ‘ExternalEntityParserCreate(context)’, initializing it with the
     appropriate callbacks, and parsing the entity.  This handler should
     return an integer; if it returns ‘0’, the parser will raise an
     ‘XML_ERROR_EXTERNAL_ENTITY_HANDLING’ error, otherwise parsing will
     continue.

     If this handler is not provided, external entities are reported by
     the *note DefaultHandler: 3e6b. callback, if provided.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/XML_external_entity_attack

   (2) https://en.wikipedia.org/wiki/Threat_model


File: python.info,  Node: ExpatError Exceptions,  Next: Example<10>,  Prev: XMLParser Objects<2>,  Up: xml parsers expat — Fast XML parsing using Expat

5.21.13.2 ExpatError Exceptions
...............................

*note ExpatError: 1480. exceptions have a number of interesting
attributes:

 -- Attributo: ExpatError.code

     Expat’s internal error number for the specific error.  The *note
     errors.messages: 3e70. dictionary maps these error numbers to
     Expat’s error messages.  For example:

          from xml.parsers.expat import ParserCreate, ExpatError, errors

          p = ParserCreate()
          try:
              p.Parse(some_xml_document)
          except ExpatError as err:
              print("Error:", errors.messages[err.code])

     The *note errors: 12d. module also provides error message constants
     and a dictionary *note codes: 3e71. mapping these messages back to
     the error codes, see below.

 -- Attributo: ExpatError.lineno

     Line number on which the error was detected.  The first line is
     numbered ‘1’.

 -- Attributo: ExpatError.offset

     Character offset into the line where the error occurred.  The first
     column is numbered ‘0’.


File: python.info,  Node: Example<10>,  Next: Content Model Descriptions,  Prev: ExpatError Exceptions,  Up: xml parsers expat — Fast XML parsing using Expat

5.21.13.3 Example
.................

The following program defines three handlers that just print out their
arguments.

     import xml.parsers.expat

     # 3 handler functions
     def start_element(name, attrs):
         print('Start element:', name, attrs)
     def end_element(name):
         print('End element:', name)
     def char_data(data):
         print('Character data:', repr(data))

     p = xml.parsers.expat.ParserCreate()

     p.StartElementHandler = start_element
     p.EndElementHandler = end_element
     p.CharacterDataHandler = char_data

     p.Parse("""<?xml version="1.0"?>
     <parent id="top"><child1 name="paul">Text goes here</child1>
     <child2 name="fred">More text</child2>
     </parent>""", 1)

The output from this program is:

     Start element: parent {'id': 'top'}
     Start element: child1 {'name': 'paul'}
     Character data: 'Text goes here'
     End element: child1
     Character data: '\n'
     Start element: child2 {'name': 'fred'}
     Character data: 'More text'
     End element: child2
     Character data: '\n'
     End element: parent


File: python.info,  Node: Content Model Descriptions,  Next: Expat error constants,  Prev: Example<10>,  Up: xml parsers expat — Fast XML parsing using Expat

5.21.13.4 Content Model Descriptions
....................................

Content models are described using nested tuples.  Each tuple contains
four values: the type, the quantifier, the name, and a tuple of
children.  Children are simply additional content model descriptions.

The values of the first two fields are constants defined in the *note
xml.parsers.expat.model: 12e. module.  These constants can be collected
in two groups: the model type group and the quantifier group.

The constants in the model type group are:

 -- Dati: xml.parsers.expat.model.XML_CTYPE_ANY

     The element named by the model name was declared to have a content
     model of ‘ANY’.

 -- Dati: xml.parsers.expat.model.XML_CTYPE_CHOICE

     The named element allows a choice from a number of options; this is
     used for content models such as ‘(A | B | C)’.

 -- Dati: xml.parsers.expat.model.XML_CTYPE_EMPTY

     Elements which are declared to be ‘EMPTY’ have this model type.

 -- Dati: xml.parsers.expat.model.XML_CTYPE_MIXED

 -- Dati: xml.parsers.expat.model.XML_CTYPE_NAME

 -- Dati: xml.parsers.expat.model.XML_CTYPE_SEQ

     Models which represent a series of models which follow one after
     the other are indicated with this model type.  This is used for
     models such as ‘(A, B, C)’.

The constants in the quantifier group are:

 -- Dati: xml.parsers.expat.model.XML_CQUANT_NONE

     No modifier is given, so it can appear exactly once, as for ‘A’.

 -- Dati: xml.parsers.expat.model.XML_CQUANT_OPT

     The model is optional: it can appear once or not at all, as for
     ‘A?’.

 -- Dati: xml.parsers.expat.model.XML_CQUANT_PLUS

     The model must occur one or more times (like ‘A+’).

 -- Dati: xml.parsers.expat.model.XML_CQUANT_REP

     The model must occur zero or more times, as for ‘A*’.


File: python.info,  Node: Expat error constants,  Prev: Content Model Descriptions,  Up: xml parsers expat — Fast XML parsing using Expat

5.21.13.5 Expat error constants
...............................

The following constants are provided in the *note
xml.parsers.expat.errors: 12d. module.  These constants are useful in
interpreting some of the attributes of the ‘ExpatError’ exception
objects raised when an error has occurred.  Since for backwards
compatibility reasons, the constants” value is the error 'message' and
not the numeric error 'code', you do this by comparing its *note code:
1b. attribute with ‘errors.codes[errors.XML_ERROR_CONSTANT_NAME]’.

The ‘errors’ module has the following attributes:

 -- Dati: xml.parsers.expat.errors.codes

     A dictionary mapping string descriptions to their error codes.

     Added in version 3.2.

 -- Dati: xml.parsers.expat.errors.messages

     A dictionary mapping numeric error codes to their string
     descriptions.

     Added in version 3.2.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_ASYNC_ENTITY

 -- Dati:
          xml.parsers.expat.errors.XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF

     An entity reference in an attribute value referred to an external
     entity instead of an internal entity.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_BAD_CHAR_REF

     A character reference referred to a character which is illegal in
     XML (for example, character ‘0’, or “‘&#0;’”).

 -- Dati: xml.parsers.expat.errors.XML_ERROR_BINARY_ENTITY_REF

     An entity reference referred to an entity which was declared with a
     notation, so cannot be parsed.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_DUPLICATE_ATTRIBUTE

     An attribute was used more than once in a start tag.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_INCORRECT_ENCODING

 -- Dati: xml.parsers.expat.errors.XML_ERROR_INVALID_TOKEN

     Raised when an input byte could not properly be assigned to a
     character; for example, a NUL byte (value ‘0’) in a UTF-8 input
     stream.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_JUNK_AFTER_DOC_ELEMENT

     Something other than whitespace occurred after the document
     element.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_MISPLACED_XML_PI

     An XML declaration was found somewhere other than the start of the
     input data.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_NO_ELEMENTS

     The document contains no elements (XML requires all documents to
     contain exactly one top-level element)..

 -- Dati: xml.parsers.expat.errors.XML_ERROR_NO_MEMORY

     Expat was not able to allocate memory internally.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_PARAM_ENTITY_REF

     A parameter entity reference was found where it was not allowed.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_PARTIAL_CHAR

     An incomplete character was found in the input.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_RECURSIVE_ENTITY_REF

     An entity reference contained another reference to the same entity;
     possibly via a different name, and possibly indirectly.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_SYNTAX

     Some unspecified syntax error was encountered.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_TAG_MISMATCH

     An end tag did not match the innermost open start tag.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_UNCLOSED_TOKEN

     Some token (such as a start tag) was not closed before the end of
     the stream or the next token was encountered.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_UNDEFINED_ENTITY

     A reference was made to an entity which was not defined.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_UNKNOWN_ENCODING

     The document encoding is not supported by Expat.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_UNCLOSED_CDATA_SECTION

     A CDATA marked section was not closed.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_EXTERNAL_ENTITY_HANDLING

 -- Dati: xml.parsers.expat.errors.XML_ERROR_NOT_STANDALONE

     The parser determined that the document was not «standalone» though
     it declared itself to be in the XML declaration, and the
     ‘NotStandaloneHandler’ was set and returned ‘0’.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_UNEXPECTED_STATE

 -- Dati: xml.parsers.expat.errors.XML_ERROR_ENTITY_DECLARED_IN_PE

 -- Dati: xml.parsers.expat.errors.XML_ERROR_FEATURE_REQUIRES_XML_DTD

     An operation was requested that requires DTD support to be compiled
     in, but Expat was configured without DTD support.  This should
     never be reported by a standard build of the *note
     xml.parsers.expat: 12c. module.

 -- Dati:
          xml.parsers.expat.errors.XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING

     A behavioral change was requested after parsing started that can
     only be changed before parsing has started.  This is (currently)
     only raised by ‘UseForeignDTD()’.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_UNBOUND_PREFIX

     An undeclared prefix was found when namespace processing was
     enabled.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_UNDECLARING_PREFIX

     The document attempted to remove the namespace declaration
     associated with a prefix.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_INCOMPLETE_PE

     A parameter entity contained incomplete markup.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_XML_DECL

     The document contained no document element at all.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_TEXT_DECL

     There was an error parsing a text declaration in an external
     entity.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_PUBLICID

     Characters were found in the public id that are not allowed.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_SUSPENDED

     The requested operation was made on a suspended parser, but isn’t
     allowed.  This includes attempts to provide additional input or to
     stop the parser.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_NOT_SUSPENDED

     An attempt to resume the parser was made when the parser had not
     been suspended.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_ABORTED

     This should not be reported to Python applications.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_FINISHED

     The requested operation was made on a parser which was finished
     parsing input, but isn’t allowed.  This includes attempts to
     provide additional input or to stop the parser.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_SUSPEND_PE

 -- Dati: xml.parsers.expat.errors.XML_ERROR_RESERVED_PREFIX_XML

     An attempt was made to undeclare reserved namespace prefix ‘xml’ or
     to bind it to another namespace URI.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_RESERVED_PREFIX_XMLNS

     An attempt was made to declare or undeclare reserved namespace
     prefix ‘xmlns’.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_RESERVED_NAMESPACE_URI

     An attempt was made to bind the URI of one the reserved namespace
     prefixes ‘xml’ and ‘xmlns’ to another namespace prefix.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_INVALID_ARGUMENT

     This should not be reported to Python applications.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_NO_BUFFER

     This should not be reported to Python applications.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_AMPLIFICATION_LIMIT_BREACH

     The limit on input amplification factor (from DTD and entities) has
     been breached.

 -- Dati: xml.parsers.expat.errors.XML_ERROR_NOT_STARTED

     The parser was tried to be stopped or suspended before it started.

     Added in version 3.14.


File: python.info,  Node: Internet Protocols and Support,  Next: Multimedia Services,  Prev: Structured Markup Processing Tools,  Up: The Python Standard Library

5.22 Internet Protocols and Support
===================================

The modules described in this chapter implement internet protocols and
support for related technology.  They are all implemented in Python.
Most of these modules require the presence of the system-dependent
module *note socket: d1, which is currently supported on most popular
platforms.  Here is an overview:

* Menu:

* webbrowser — Convenient web-browser controller::
* wsgiref — WSGI Utilities and Reference Implementation::
* urllib — URL handling modules::
* urllib.request — Extensible library for opening URLs: urllib request — Extensible library for opening URLs.
* urllib.response — Response classes used by urllib: urllib response — Response classes used by urllib.
* urllib.parse — Parse URLs into components: urllib parse — Parse URLs into components.
* urllib.error — Exception classes raised by urllib.request: urllib error — Exception classes raised by urllib request.
* urllib.robotparser — Parser for robots.txt: urllib robotparser — Parser for robots txt.
* http — HTTP modules::
* http.client — HTTP protocol client: http client — HTTP protocol client.
* ftplib — FTP protocol client::
* poplib — POP3 protocol client::
* imaplib — IMAP4 protocol client::
* smtplib — SMTP protocol client::
* uuid — UUID objects according to RFC 9562::
* socketserver — A framework for network servers::
* http.server — HTTP servers: http server — HTTP servers.
* http.cookies — HTTP state management: http cookies — HTTP state management.
* http.cookiejar — Cookie handling for HTTP clients: http cookiejar — Cookie handling for HTTP clients.
* xmlrpc — XMLRPC server and client modules::
* xmlrpc.client — XML-RPC client access: xmlrpc client — XML-RPC client access.
* xmlrpc.server — Basic XML-RPC servers: xmlrpc server — Basic XML-RPC servers.
* ipaddress — IPv4/IPv6 manipulation library::


File: python.info,  Node: webbrowser — Convenient web-browser controller,  Next: wsgiref — WSGI Utilities and Reference Implementation,  Up: Internet Protocols and Support

5.22.1 ‘webbrowser’ — Convenient web-browser controller
-------------------------------------------------------

'Source code:' Lib/webbrowser.py(1)

__________________________________________________________________

The *note webbrowser: 11b. module provides a high-level interface to
allow displaying web-based documents to users.  Under most
circumstances, simply calling the *note open(): 1871. function from this
module will do the right thing.

Under Unix, graphical browsers are preferred under X11, but text-mode
browsers will be used if graphical browsers are not available or an X11
display isn’t available.  If text-mode browsers are used, the calling
process will block until the user exits the browser.

If the environment variable ‘BROWSER’ exists, it is interpreted as the
*note os.pathsep: 211d.-separated list of browsers to try ahead of the
platform defaults.  When the value of a list part contains the string
‘%s’, then it is interpreted as a literal browser command line to be
used with the argument URL substituted for ‘%s’; if the value is a
single word that refers to one of the already registered browsers this
browser is added to the front of the search list; if the part does not
contain ‘%s’, it is simply interpreted as the name of the browser to
launch.  (2)

Cambiato nella versione 3.14: The ‘BROWSER’ variable can now also be
used to reorder the list of platform defaults.  This is particularly
useful on macOS where the platform defaults do not refer to command-line
tools on ‘PATH’.

For non-Unix platforms, or when a remote browser is available on Unix,
the controlling process will not wait for the user to finish with the
browser, but allow the remote browser to maintain its own windows on the
display.  If remote browsers are not available on Unix, the controlling
process will launch a new browser and wait.

On iOS, the ‘BROWSER’ environment variable, as well as any arguments
controlling autoraise, browser preference, and new tab/window creation
will be ignored.  Web pages will 'always' be opened in the user’s
preferred browser, in a new tab, with the browser being brought to the
foreground.  The use of the *note webbrowser: 11b. module on iOS
requires the *note ctypes: 2e. module.  If *note ctypes: 2e. isn’t
available, calls to *note open(): 1871. will fail.

* Menu:

* Command-line interface: Command-line interface<6>.
* Browser controller objects::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/webbrowser.py

   (2) Executables named here without a full path will be searched in
the directories given in the ‘PATH’ environment variable.


File: python.info,  Node: Command-line interface<6>,  Next: Browser controller objects,  Up: webbrowser — Convenient web-browser controller

5.22.1.1 Command-line interface
...............................

The script ‘webbrowser’ can be used as a command-line interface for the
module.  It accepts a URL as the argument.  It accepts the following
optional parameters:

 -- Option: -n, --new-window

     Opens the URL in a new browser window, if possible.

 -- Option: -t, --new-tab

     Opens the URL in a new browser tab.

The options are, naturally, mutually exclusive.  Usage example:

     python -m webbrowser -t "https://www.python.org"

*note Availability: 2128.: not WASI, not Android.

The following exception is defined:

 -- Eccezione: webbrowser.Error

     Exception raised when a browser control error occurs.

The following functions are defined:

 -- Funzione: webbrowser.open (url, new=0, autoraise=True)

     Display 'url' using the default browser.  If 'new' is 0, the 'url'
     is opened in the same browser window if possible.  If 'new' is 1, a
     new browser window is opened if possible.  If 'new' is 2, a new
     browser page («tab») is opened if possible.  If 'autoraise' is
     ‘True’, the window is raised if possible (note that under many
     window managers this will occur regardless of the setting of this
     variable).

     Returns ‘True’ if a browser was successfully launched, ‘False’
     otherwise.

     Note that on some platforms, trying to open a filename using this
     function, may work and start the operating system’s associated
     program.  However, this is neither supported nor portable.

     Raises an *note auditing event: 1c56. ‘webbrowser.open’ with
     argument ‘url’.

 -- Funzione: webbrowser.open_new (url)

     Open 'url' in a new window of the default browser, if possible,
     otherwise, open 'url' in the only browser window.

     Returns ‘True’ if a browser was successfully launched, ‘False’
     otherwise.

 -- Funzione: webbrowser.open_new_tab (url)

     Open 'url' in a new page («tab») of the default browser, if
     possible, otherwise equivalent to *note open_new(): 3eb0.

     Returns ‘True’ if a browser was successfully launched, ‘False’
     otherwise.

 -- Funzione: webbrowser.get (using=None)

     Return a controller object for the browser type 'using'.  If
     'using' is ‘None’, return a controller for a default browser
     appropriate to the caller’s environment.

 -- Funzione: webbrowser.register (name, constructor, instance=None, *,
          preferred=False)

     Register the browser type 'name'.  Once a browser type is
     registered, the *note get(): 3eb2. function can return a controller
     for that browser type.  If 'instance' is not provided, or is
     ‘None’, 'constructor' will be called without parameters to create
     an instance when needed.  If 'instance' is provided, 'constructor'
     will never be called, and may be ‘None’.

     Setting 'preferred' to ‘True’ makes this browser a preferred result
     for a *note get(): 3eb2. call with no argument.  Otherwise, this
     entry point is only useful if you plan to either set the ‘BROWSER’
     variable or call *note get(): 3eb2. with a nonempty argument
     matching the name of a handler you declare.

     Cambiato nella versione 3.7: 'preferred' keyword-only parameter was
     added.

A number of browser types are predefined.  This table gives the type
names that may be passed to the *note get(): 3eb2. function and the
corresponding instantiations for the controller classes, all defined in
this module.

Type Name                    Class Name                                    Notes
                                                                           
---------------------------------------------------------------------------------------
                                                                           
‘'mozilla'’                  ‘Mozilla('mozilla')’
                             
                                                                           
‘'firefox'’                  ‘Mozilla('mozilla')’
                             
                                                                           
‘'epiphany'’                 ‘Epiphany('epiphany')’
                             
                                                                           
‘'kfmclient'’                ‘Konqueror()’                                 (1)
                                                                           
                                                                           
‘'konqueror'’                ‘Konqueror()’                                 (1)
                                                                           
                                                                           
‘'kfm'’                      ‘Konqueror()’                                 (1)
                                                                           
                                                                           
‘'opera'’                    ‘Opera()’
                             
                                                                           
‘'links'’                    ‘GenericBrowser('links')’
                             
                                                                           
‘'elinks'’                   ‘Elinks('elinks')’
                             
                                                                           
‘'lynx'’                     ‘GenericBrowser('lynx')’
                             
                                                                           
‘'w3m'’                      ‘GenericBrowser('w3m')’
                             
                                                                           
‘'windows-default'’          ‘WindowsDefault’                              (2)
                                                                           
                                                                           
‘'macosx'’                   ‘MacOSXOSAScript('default')’                  (3)
                                                                           
                                                                           
‘'safari'’                   ‘MacOSXOSAScript('safari')’                   (3)
                                                                           
                                                                           
‘'google-chrome'’            ‘Chrome('google-chrome')’
                             
                                                                           
‘'chrome'’                   ‘Chrome('chrome')’
                             
                                                                           
‘'chromium'’                 ‘Chromium('chromium')’
                             
                                                                           
‘'chromium-browser'’         ‘Chromium('chromium-browser')’
                             
                                                                           
‘'iosbrowser'’               ‘IOSBrowser’                                  (4)
                                                                           

Notes:

  1. «Konqueror» is the file manager for the KDE desktop environment for
     Unix, and only makes sense to use if KDE is running.  Some way of
     reliably detecting KDE would be nice; the ‘KDEDIR’ variable is not
     sufficient.  Note also that the name «kfm» is used even when using
     the ‘konqueror’ command with KDE 2 — the implementation selects the
     best strategy for running Konqueror.

  2. Only on Windows platforms.

  3. Only on macOS.

  4. Only on iOS.

Added in version 3.2: A new ‘MacOSXOSAScript’ class has been added and
is used on Mac instead of the previous ‘MacOSX’ class.  This adds
support for opening browsers not currently set as the OS default.

Added in version 3.3: Support for Chrome/Chromium has been added.

Cambiato nella versione 3.12: Support for several obsolete browsers has
been removed.  Removed browsers include Grail, Mosaic, Netscape, Galeon,
Skipstone, Iceape, and Firefox versions 35 and below.

Cambiato nella versione 3.13: Support for iOS has been added.

Here are some simple examples:

     url = 'https://docs.python.org/'

     # Open URL in a new tab, if a browser window is already open.
     webbrowser.open_new_tab(url)

     # Open URL in new window, raising the window if possible.
     webbrowser.open_new(url)


File: python.info,  Node: Browser controller objects,  Prev: Command-line interface<6>,  Up: webbrowser — Convenient web-browser controller

5.22.1.2 Browser controller objects
...................................

Browser controllers provide the *note name: 59a. attribute, and the
following three methods which parallel module-level convenience
functions:

 -- Attributo: controller.name

     System-dependent name for the browser.

 -- Metodo: controller.open (url, new=0, autoraise=True)

     Display 'url' using the browser handled by this controller.  If
     'new' is 1, a new browser window is opened if possible.  If 'new'
     is 2, a new browser page («tab») is opened if possible.

 -- Metodo: controller.open_new (url)

     Open 'url' in a new window of the browser handled by this
     controller, if possible, otherwise, open 'url' in the only browser
     window.  Alias *note open_new(): 3eb0.

 -- Metodo: controller.open_new_tab (url)

     Open 'url' in a new page («tab») of the browser handled by this
     controller, if possible, otherwise equivalent to *note open_new():
     3eb0.


File: python.info,  Node: wsgiref — WSGI Utilities and Reference Implementation,  Next: urllib — URL handling modules,  Prev: webbrowser — Convenient web-browser controller,  Up: Internet Protocols and Support

5.22.2 ‘wsgiref’ — WSGI Utilities and Reference Implementation
--------------------------------------------------------------

'Source code:' Lib/wsgiref(1)

__________________________________________________________________

The Web Server Gateway Interface (WSGI) is a standard interface between
web server software and web applications written in Python.  Having a
standard interface makes it easy to use an application that supports
WSGI with a number of different web servers.

Only authors of web servers and programming frameworks need to know
every detail and corner case of the WSGI design.  You don’t need to
understand every detail of WSGI just to install a WSGI application or to
write a web application using an existing framework.

*note wsgiref: 11e. is a reference implementation of the WSGI
specification that can be used to add WSGI support to a web server or
framework.  It provides utilities for manipulating WSGI environment
variables and response headers, base classes for implementing WSGI
servers, a demo HTTP server that serves WSGI applications, types for
static type checking, and a validation tool that checks WSGI servers and
applications for conformance to the WSGI specification ( PEP 3333(2)).

See wsgi.readthedocs.io(3) for more information about WSGI, and links to
tutorials and other resources.

* Menu:

* wsgiref.util – WSGI environment utilities: wsgiref util – WSGI environment utilities.
* wsgiref.headers – WSGI response header tools: wsgiref headers – WSGI response header tools.
* wsgiref.simple_server – a simple WSGI HTTP server: wsgiref simple_server – a simple WSGI HTTP server.
* wsgiref.validate — WSGI conformance checker: wsgiref validate — WSGI conformance checker.
* wsgiref.handlers – server/gateway base classes: wsgiref handlers – server/gateway base classes.
* wsgiref.types – WSGI types for static type checking: wsgiref types – WSGI types for static type checking.
* Examples: Examples<26>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/wsgiref

   (2) https://peps.python.org/pep-3333/

   (3) https://wsgi.readthedocs.io/


File: python.info,  Node: wsgiref util – WSGI environment utilities,  Next: wsgiref headers – WSGI response header tools,  Up: wsgiref — WSGI Utilities and Reference Implementation

5.22.2.1 ‘wsgiref.util’ – WSGI environment utilities
....................................................

This module provides a variety of utility functions for working with
WSGI environments.  A WSGI environment is a dictionary containing HTTP
request variables as described in PEP 3333(1).  All of the functions
taking an 'environ' parameter expect a WSGI-compliant dictionary to be
supplied; please see PEP 3333(2) for a detailed specification and *note
WSGIEnvironment: 3ebd. for a type alias that can be used in type
annotations.

 -- Funzione: wsgiref.util.guess_scheme (environ)

     Return a guess for whether ‘wsgi.url_scheme’ should be «http» or
     «https», by checking for a ‘HTTPS’ environment variable in the
     'environ' dictionary.  The return value is a string.

     This function is useful when creating a gateway that wraps CGI or a
     CGI-like protocol such as FastCGI. Typically, servers providing
     such protocols will include a ‘HTTPS’ variable with a value of «1»,
     «yes», or «on» when a request is received via SSL. So, this
     function returns «https» if such a value is found, and «http»
     otherwise.

 -- Funzione: wsgiref.util.request_uri (environ, include_query=True)

     Return the full request URI, optionally including the query string,
     using the algorithm found in the «URL Reconstruction» section of
     PEP 3333(3).  If 'include_query' is false, the query string is not
     included in the resulting URI.

 -- Funzione: wsgiref.util.application_uri (environ)

     Similar to *note request_uri(): 3ebf, except that the ‘PATH_INFO’
     and ‘QUERY_STRING’ variables are ignored.  The result is the base
     URI of the application object addressed by the request.

 -- Funzione: wsgiref.util.shift_path_info (environ)

     Shift a single name from ‘PATH_INFO’ to ‘SCRIPT_NAME’ and return
     the name.  The 'environ' dictionary is 'modified' in-place; use a
     copy if you need to keep the original ‘PATH_INFO’ or ‘SCRIPT_NAME’
     intact.

     If there are no remaining path segments in ‘PATH_INFO’, ‘None’ is
     returned.

     Typically, this routine is used to process each portion of a
     request URI path, for example to treat the path as a series of
     dictionary keys.  This routine modifies the passed-in environment
     to make it suitable for invoking another WSGI application that is
     located at the target URI. For example, if there is a WSGI
     application at ‘/foo’, and the request URI path is ‘/foo/bar/baz’,
     and the WSGI application at ‘/foo’ calls *note shift_path_info():
     3ec1, it will receive the string «bar», and the environment will be
     updated to be suitable for passing to a WSGI application at
     ‘/foo/bar’.  That is, ‘SCRIPT_NAME’ will change from ‘/foo’ to
     ‘/foo/bar’, and ‘PATH_INFO’ will change from ‘/bar/baz’ to ‘/baz’.

     When ‘PATH_INFO’ is just a «/», this routine returns an empty
     string and appends a trailing slash to ‘SCRIPT_NAME’, even though
     empty path segments are normally ignored, and ‘SCRIPT_NAME’ doesn’t
     normally end in a slash.  This is intentional behavior, to ensure
     that an application can tell the difference between URIs ending in
     ‘/x’ from ones ending in ‘/x/’ when using this routine to do object
     traversal.

 -- Funzione: wsgiref.util.setup_testing_defaults (environ)

     Update 'environ' with trivial defaults for testing purposes.

     This routine adds various parameters required for WSGI, including
     ‘HTTP_HOST’, ‘SERVER_NAME’, ‘SERVER_PORT’, ‘REQUEST_METHOD’,
     ‘SCRIPT_NAME’, ‘PATH_INFO’, and all of the PEP 3333(4)-defined
     ‘wsgi.*’ variables.  It only supplies default values, and does not
     replace any existing settings for these variables.

     This routine is intended to make it easier for unit tests of WSGI
     servers and applications to set up dummy environments.  It should
     NOT be used by actual WSGI servers or applications, since the data
     is fake!

     Example usage (see also *note demo_app(): 3ec3. for another
     example):

          from wsgiref.util import setup_testing_defaults
          from wsgiref.simple_server import make_server

          # A relatively simple WSGI application. It's going to print out the
          # environment dictionary after being updated by setup_testing_defaults
          def simple_app(environ, start_response):
              setup_testing_defaults(environ)

              status = '200 OK'
              headers = [('Content-type', 'text/plain; charset=utf-8')]

              start_response(status, headers)

              ret = [("%s: %s\n" % (key, value)).encode("utf-8")
                     for key, value in environ.items()]
              return ret

          with make_server('', 8000, simple_app) as httpd:
              print("Serving on port 8000...")
              httpd.serve_forever()

In addition to the environment functions above, the *note wsgiref.util:
123. module also provides these miscellaneous utilities:

 -- Funzione: wsgiref.util.is_hop_by_hop (header_name)

     Return ‘True’ if “header_name” is an HTTP/1.1 «Hop-by-Hop» header,
     as defined by RFC 2616(5).

 -- Classe: wsgiref.util.FileWrapper (filelike, blksize=8192)

     A concrete implementation of the *note wsgiref.types.FileWrapper:
     3ec4. protocol used to convert a file-like object to an *note
     iterator: 4c9.  The resulting objects are *note iterable: 142f.s.
     As the object is iterated over, the optional 'blksize' parameter
     will be repeatedly passed to the 'filelike' object’s ‘read()’
     method to obtain bytestrings to yield.  When ‘read()’ returns an
     empty bytestring, iteration is ended and is not resumable.

     If 'filelike' has a ‘close()’ method, the returned object will also
     have a ‘close()’ method, and it will invoke the 'filelike' object’s
     ‘close()’ method when called.

     Example usage:

          from io import StringIO
          from wsgiref.util import FileWrapper

          # We're using a StringIO-buffer for as the file-like object
          filelike = StringIO("This is an example file-like object"*10)
          wrapper = FileWrapper(filelike, blksize=5)

          for chunk in wrapper:
              print(chunk)

     Cambiato nella versione 3.11: Support for *note __getitem__(): 588.
     method has been removed.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3333/

   (2) https://peps.python.org/pep-3333/

   (3) https://peps.python.org/pep-3333/

   (4) https://peps.python.org/pep-3333/

   (5) https://datatracker.ietf.org/doc/html/rfc2616.html


File: python.info,  Node: wsgiref headers – WSGI response header tools,  Next: wsgiref simple_server – a simple WSGI HTTP server,  Prev: wsgiref util – WSGI environment utilities,  Up: wsgiref — WSGI Utilities and Reference Implementation

5.22.2.2 ‘wsgiref.headers’ – WSGI response header tools
.......................................................

This module provides a single class, *note Headers: 109a, for convenient
manipulation of WSGI response headers using a mapping-like interface.

 -- Classe: wsgiref.headers.Headers ([headers])

     Create a mapping-like object wrapping 'headers', which must be a
     list of header name/value tuples as described in PEP 3333(1).  The
     default value of 'headers' is an empty list.

     *note Headers: 109a. objects support typical mapping operations
     including *note __getitem__(): 588, *note get(): 201e, *note
     __setitem__(): 14d3, *note setdefault(): 127b, *note __delitem__():
     14d4. and *note __contains__(): 15c1.  For each of these methods,
     the key is the header name (treated case-insensitively), and the
     value is the first value associated with that header name.  Setting
     a header deletes any existing values for that header, then adds a
     new value at the end of the wrapped header list.  Headers” existing
     order is generally maintained, with new headers added to the end of
     the wrapped list.

     Unlike a dictionary, *note Headers: 109a. objects do not raise an
     error when you try to get or delete a key that isn’t in the wrapped
     header list.  Getting a nonexistent header just returns ‘None’, and
     deleting a nonexistent header does nothing.

     *note Headers: 109a. objects also support ‘keys()’, ‘values()’, and
     ‘items()’ methods.  The lists returned by ‘keys()’ and ‘items()’
     can include the same key more than once if there is a multi-valued
     header.  The ‘len()’ of a *note Headers: 109a. object is the same
     as the length of its ‘items()’, which is the same as the length of
     the wrapped header list.  In fact, the ‘items()’ method just
     returns a copy of the wrapped header list.

     Calling ‘bytes()’ on a *note Headers: 109a. object returns a
     formatted bytestring suitable for transmission as HTTP response
     headers.  Each header is placed on a line with its value, separated
     by a colon and a space.  Each line is terminated by a carriage
     return and line feed, and the bytestring is terminated with a blank
     line.

     In addition to their mapping interface and formatting features,
     *note Headers: 109a. objects also have the following methods for
     querying and adding multi-valued headers, and for adding headers
     with MIME parameters:

      -- Metodo: get_all (name)

          Return a list of all the values for the named header.

          The returned list will be sorted in the order they appeared in
          the original header list or were added to this instance, and
          may contain duplicates.  Any fields deleted and re-inserted
          are always appended to the header list.  If no fields exist
          with the given name, returns an empty list.

      -- Metodo: add_header (name, value, **_params)

          Add a (possibly multi-valued) header, with optional MIME
          parameters specified via keyword arguments.

          'name' is the header field to add.  Keyword arguments can be
          used to set MIME parameters for the header field.  Each
          parameter must be a string or ‘None’.  Underscores in
          parameter names are converted to dashes, since dashes are
          illegal in Python identifiers, but many MIME parameter names
          include dashes.  If the parameter value is a string, it is
          added to the header value parameters in the form
          ‘name="value"’.  If it is ‘None’, only the parameter name is
          added.  (This is used for MIME parameters without a value.)
          Example usage:

               h.add_header('content-disposition', 'attachment', filename='bud.gif')

          The above will add a header that looks like this:

               Content-Disposition: attachment; filename="bud.gif"

     Cambiato nella versione 3.5: 'headers' parameter is optional.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3333/


File: python.info,  Node: wsgiref simple_server – a simple WSGI HTTP server,  Next: wsgiref validate — WSGI conformance checker,  Prev: wsgiref headers – WSGI response header tools,  Up: wsgiref — WSGI Utilities and Reference Implementation

5.22.2.3 ‘wsgiref.simple_server’ – a simple WSGI HTTP server
............................................................

This module implements a simple HTTP server (based on *note http.server:
76.) that serves WSGI applications.  Each server instance serves a
single WSGI application on a given host and port.  If you want to serve
multiple applications on a single host and port, you should create a
WSGI application that parses ‘PATH_INFO’ to select which application to
invoke for each request.  (E.g., using the ‘shift_path_info()’ function
from *note wsgiref.util: 123.)

 -- Funzione: wsgiref.simple_server.make_server (host, port, app,
          server_class=WSGIServer, handler_class=WSGIRequestHandler)

     Create a new WSGI server listening on 'host' and 'port', accepting
     connections for 'app'.  The return value is an instance of the
     supplied 'server_class', and will process requests using the
     specified 'handler_class'.  'app' must be a WSGI application
     object, as defined by PEP 3333(1).

     Example usage:

          from wsgiref.simple_server import make_server, demo_app

          with make_server('', 8000, demo_app) as httpd:
              print("Serving HTTP on port 8000...")

              # Respond to requests until process is killed
              httpd.serve_forever()

              # Alternative: serve one request, then exit
              httpd.handle_request()

 -- Funzione: wsgiref.simple_server.demo_app (environ, start_response)

     This function is a small but complete WSGI application that returns
     a text page containing the message «Hello world!» and a list of the
     key/value pairs provided in the 'environ' parameter.  It’s useful
     for verifying that a WSGI server (such as *note
     wsgiref.simple_server: 121.) is able to run a simple WSGI
     application correctly.

     The 'start_response' callable should follow the *note
     StartResponse: 3eca. protocol.

 -- Classe: wsgiref.simple_server.WSGIServer (server_address,
          RequestHandlerClass)

     Create a *note WSGIServer: 3ecb. instance.  'server_address' should
     be a ‘(host,port)’ tuple, and 'RequestHandlerClass' should be the
     subclass of *note http.server.BaseHTTPRequestHandler: 12d3. that
     will be used to process requests.

     You do not normally need to call this constructor, as the *note
     make_server(): 3ec9. function can handle all the details for you.

     *note WSGIServer: 3ecb. is a subclass of *note
     http.server.HTTPServer: 3ecc, so all of its methods (such as
     ‘serve_forever()’ and ‘handle_request()’) are available.  *note
     WSGIServer: 3ecb. also provides these WSGI-specific methods:

      -- Metodo: set_app (application)

          Sets the callable 'application' as the WSGI application that
          will receive requests.

      -- Metodo: get_app ()

          Returns the currently set application callable.

     Normally, however, you do not need to use these additional methods,
     as *note set_app(): 3ecd. is normally called by *note
     make_server(): 3ec9, and the *note get_app(): 3ece. exists mainly
     for the benefit of request handler instances.

 -- Classe: wsgiref.simple_server.WSGIRequestHandler (request,
          client_address, server)

     Create an HTTP handler for the given 'request' (i.e.  a socket),
     'client_address' (a ‘(host,port)’ tuple), and 'server' (*note
     WSGIServer: 3ecb. instance).

     You do not need to create instances of this class directly; they
     are automatically created as needed by *note WSGIServer: 3ecb.
     objects.  You can, however, subclass this class and supply it as a
     'handler_class' to the *note make_server(): 3ec9. function.  Some
     possibly relevant methods for overriding in subclasses:

      -- Metodo: get_environ ()

          Return a *note WSGIEnvironment: 3ebd. dictionary for a
          request.  The default implementation copies the contents of
          the *note WSGIServer: 3ecb. object’s ‘base_environ’ dictionary
          attribute and then adds various headers derived from the HTTP
          request.  Each call to this method should return a new
          dictionary containing all of the relevant CGI environment
          variables as specified in PEP 3333(2).

      -- Metodo: get_stderr ()

          Return the object that should be used as the ‘wsgi.errors’
          stream.  The default implementation just returns ‘sys.stderr’.

      -- Metodo: handle ()

          Process the HTTP request.  The default implementation creates
          a handler instance using a *note wsgiref.handlers: 11f. class
          to implement the actual WSGI application interface.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3333/

   (2) https://peps.python.org/pep-3333/


File: python.info,  Node: wsgiref validate — WSGI conformance checker,  Next: wsgiref handlers – server/gateway base classes,  Prev: wsgiref simple_server – a simple WSGI HTTP server,  Up: wsgiref — WSGI Utilities and Reference Implementation

5.22.2.4 ‘wsgiref.validate’ — WSGI conformance checker
......................................................

When creating new WSGI application objects, frameworks, servers, or
middleware, it can be useful to validate the new code’s conformance
using *note wsgiref.validate: 124.  This module provides a function that
creates WSGI application objects that validate communications between a
WSGI server or gateway and a WSGI application object, to check both
sides for protocol conformance.

Note that this utility does not guarantee complete PEP 3333(1)
compliance; an absence of errors from this module does not necessarily
mean that errors do not exist.  However, if this module does produce an
error, then it is virtually certain that either the server or
application is not 100% compliant.

This module is based on the ‘paste.lint’ module from Ian Bicking’s
«Python Paste» library.

 -- Funzione: wsgiref.validate.validator (application)

     Wrap 'application' and return a new WSGI application object.  The
     returned application will forward all requests to the original
     'application', and will check that both the 'application' and the
     server invoking it are conforming to the WSGI specification and to
     RFC 2616(2).

     Any detected nonconformance results in an *note AssertionError:
     8b9. being raised; note, however, that how these errors are handled
     is server-dependent.  For example, *note wsgiref.simple_server:
     121. and other servers based on *note wsgiref.handlers: 11f. (that
     don’t override the error handling methods to do something else)
     will simply output a message that an error has occurred, and dump
     the traceback to ‘sys.stderr’ or some other error stream.

     This wrapper may also generate output using the *note warnings:
     118. module to indicate behaviors that are questionable but which
     may not actually be prohibited by PEP 3333(3).  Unless they are
     suppressed using Python command-line options or the *note warnings:
     118. API, any such warnings will be written to ‘sys.stderr’ ('not'
     ‘wsgi.errors’, unless they happen to be the same object).

     Example usage:

          from wsgiref.validate import validator
          from wsgiref.simple_server import make_server

          # Our callable object which is intentionally not compliant to the
          # standard, so the validator is going to break
          def simple_app(environ, start_response):
              status = '200 OK'  # HTTP Status
              headers = [('Content-type', 'text/plain')]  # HTTP Headers
              start_response(status, headers)

              # This is going to break because we need to return a list, and
              # the validator is going to inform us
              return b"Hello World"

          # This is the application wrapped in a validator
          validator_app = validator(simple_app)

          with make_server('', 8000, validator_app) as httpd:
              print("Listening on port 8000....")
              httpd.serve_forever()

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3333/

   (2) https://datatracker.ietf.org/doc/html/rfc2616.html

   (3) https://peps.python.org/pep-3333/


File: python.info,  Node: wsgiref handlers – server/gateway base classes,  Next: wsgiref types – WSGI types for static type checking,  Prev: wsgiref validate — WSGI conformance checker,  Up: wsgiref — WSGI Utilities and Reference Implementation

5.22.2.5 ‘wsgiref.handlers’ – server/gateway base classes
.........................................................

This module provides base handler classes for implementing WSGI servers
and gateways.  These base classes handle most of the work of
communicating with a WSGI application, as long as they are given a
CGI-like environment, along with input, output, and error streams.

 -- Classe: wsgiref.handlers.CGIHandler

     CGI-based invocation via ‘sys.stdin’, ‘sys.stdout’, ‘sys.stderr’
     and ‘os.environ’.  This is useful when you have a WSGI application
     and want to run it as a CGI script.  Simply invoke
     ‘CGIHandler().run(app)’, where ‘app’ is the WSGI application object
     you wish to invoke.

     This class is a subclass of *note BaseCGIHandler: 3ed7. that sets
     ‘wsgi.run_once’ to true, ‘wsgi.multithread’ to false, and
     ‘wsgi.multiprocess’ to true, and always uses *note sys: df. and
     *note os: a5. to obtain the necessary CGI streams and environment.

 -- Classe: wsgiref.handlers.IISCGIHandler

     A specialized alternative to *note CGIHandler: 3ed6, for use when
     deploying on Microsoft’s IIS web server, without having set the
     config allowPathInfo option (IIS>=7) or metabase
     allowPathInfoForScriptMappings (IIS<7).

     By default, IIS gives a ‘PATH_INFO’ that duplicates the
     ‘SCRIPT_NAME’ at the front, causing problems for WSGI applications
     that wish to implement routing.  This handler strips any such
     duplicated path.

     IIS can be configured to pass the correct ‘PATH_INFO’, but this
     causes another bug where ‘PATH_TRANSLATED’ is wrong.  Luckily this
     variable is rarely used and is not guaranteed by WSGI. On IIS<7,
     though, the setting can only be made on a vhost level, affecting
     all other script mappings, many of which break when exposed to the
     ‘PATH_TRANSLATED’ bug.  For this reason IIS<7 is almost never
     deployed with the fix (Even IIS7 rarely uses it because there is
     still no UI for it.).

     There is no way for CGI code to tell whether the option was set, so
     a separate handler class is provided.  It is used in the same way
     as *note CGIHandler: 3ed6, i.e., by calling
     ‘IISCGIHandler().run(app)’, where ‘app’ is the WSGI application
     object you wish to invoke.

     Added in version 3.2.

 -- Classe: wsgiref.handlers.BaseCGIHandler (stdin, stdout, stderr,
          environ, multithread=True, multiprocess=False)

     Similar to *note CGIHandler: 3ed6, but instead of using the *note
     sys: df. and *note os: a5. modules, the CGI environment and I/O
     streams are specified explicitly.  The 'multithread' and
     'multiprocess' values are used to set the ‘wsgi.multithread’ and
     ‘wsgi.multiprocess’ flags for any applications run by the handler
     instance.

     This class is a subclass of *note SimpleHandler: 3ed9. intended for
     use with software other than HTTP «origin servers».  If you are
     writing a gateway protocol implementation (such as CGI, FastCGI,
     SCGI, etc.)  that uses a ‘Status:’ header to send an HTTP status,
     you probably want to subclass this instead of *note SimpleHandler:
     3ed9.

 -- Classe: wsgiref.handlers.SimpleHandler (stdin, stdout, stderr,
          environ, multithread=True, multiprocess=False)

     Similar to *note BaseCGIHandler: 3ed7, but designed for use with
     HTTP origin servers.  If you are writing an HTTP server
     implementation, you will probably want to subclass this instead of
     *note BaseCGIHandler: 3ed7.

     This class is a subclass of *note BaseHandler: 1dbb.  It overrides
     the ‘__init__()’, *note get_stdin(): 3eda, *note get_stderr():
     3edb, *note add_cgi_vars(): 3edc, *note _write(): 3edd, and *note
     _flush(): 3ede. methods to support explicitly setting the
     environment and streams via the constructor.  The supplied
     environment and streams are stored in the ‘stdin’, ‘stdout’,
     ‘stderr’, and ‘environ’ attributes.

     The *note write(): ed9. method of 'stdout' should write each chunk
     in full, like *note io.BufferedIOBase: 8a4.

 -- Classe: wsgiref.handlers.BaseHandler

     This is an abstract base class for running WSGI applications.  Each
     instance will handle a single HTTP request, although in principle
     you could create a subclass that was reusable for multiple
     requests.

     *note BaseHandler: 1dbb. instances have only one method intended
     for external use:

      -- Metodo: run (app)

          Run the specified WSGI application, 'app'.

     All of the other *note BaseHandler: 1dbb. methods are invoked by
     this method in the process of running the application, and thus
     exist primarily to allow customizing the process.

     The following methods MUST be overridden in a subclass:

      -- Metodo: _write (data)

          Buffer the bytes 'data' for transmission to the client.  It’s
          okay if this method actually transmits the data; *note
          BaseHandler: 1dbb. just separates write and flush operations
          for greater efficiency when the underlying system actually has
          such a distinction.

      -- Metodo: _flush ()

          Force buffered data to be transmitted to the client.  It’s
          okay if this method is a no-op (i.e., if *note _write(): 3edd.
          actually sends the data).

      -- Metodo: get_stdin ()

          Return an object compatible with *note InputStream: 3ee0.
          suitable for use as the ‘wsgi.input’ of the request currently
          being processed.

      -- Metodo: get_stderr ()

          Return an object compatible with *note ErrorStream: 3ee1.
          suitable for use as the ‘wsgi.errors’ of the request currently
          being processed.

      -- Metodo: add_cgi_vars ()

          Insert CGI variables for the current request into the
          ‘environ’ attribute.

     Here are some other methods and attributes you may wish to
     override.  This list is only a summary, however, and does not
     include every method that can be overridden.  You should consult
     the docstrings and source code for additional information before
     attempting to create a customized *note BaseHandler: 1dbb.
     subclass.

     Attributes and methods for customizing the WSGI environment:

      -- Attributo: wsgi_multithread

          The value to be used for the ‘wsgi.multithread’ environment
          variable.  It defaults to true in *note BaseHandler: 1dbb, but
          may have a different default (or be set by the constructor) in
          the other subclasses.

      -- Attributo: wsgi_multiprocess

          The value to be used for the ‘wsgi.multiprocess’ environment
          variable.  It defaults to true in *note BaseHandler: 1dbb, but
          may have a different default (or be set by the constructor) in
          the other subclasses.

      -- Attributo: wsgi_run_once

          The value to be used for the ‘wsgi.run_once’ environment
          variable.  It defaults to false in *note BaseHandler: 1dbb,
          but *note CGIHandler: 3ed6. sets it to true by default.

      -- Attributo: os_environ

          The default environment variables to be included in every
          request’s WSGI environment.  By default, this is a copy of
          ‘os.environ’ at the time that *note wsgiref.handlers: 11f. was
          imported, but subclasses can either create their own at the
          class or instance level.  Note that the dictionary should be
          considered read-only, since the default value is shared
          between multiple classes and instances.

      -- Attributo: server_software

          If the *note origin_server: 3ee7. attribute is set, this
          attribute’s value is used to set the default ‘SERVER_SOFTWARE’
          WSGI environment variable, and also to set a default ‘Server:’
          header in HTTP responses.  It is ignored for handlers (such as
          *note BaseCGIHandler: 3ed7. and *note CGIHandler: 3ed6.) that
          are not HTTP origin servers.

          Cambiato nella versione 3.3: The term «Python» is replaced
          with implementation specific term like «CPython», «Jython»
          etc.

      -- Metodo: get_scheme ()

          Return the URL scheme being used for the current request.  The
          default implementation uses the ‘guess_scheme()’ function from
          *note wsgiref.util: 123. to guess whether the scheme should be
          «http» or «https», based on the current request’s ‘environ’
          variables.

      -- Metodo: setup_environ ()

          Set the ‘environ’ attribute to a fully populated WSGI
          environment.  The default implementation uses all of the above
          methods and attributes, plus the *note get_stdin(): 3eda,
          *note get_stderr(): 3edb, and *note add_cgi_vars(): 3edc.
          methods and the *note wsgi_file_wrapper: 3eea. attribute.  It
          also inserts a ‘SERVER_SOFTWARE’ key if not present, as long
          as the *note origin_server: 3ee7. attribute is a true value
          and the *note server_software: 3ee6. attribute is set.

     Methods and attributes for customizing exception handling:

      -- Metodo: log_exception (exc_info)

          Log the 'exc_info' tuple in the server log.  'exc_info' is a
          ‘(type, value, traceback)’ tuple.  The default implementation
          simply writes the traceback to the request’s ‘wsgi.errors’
          stream and flushes it.  Subclasses can override this method to
          change the format or retarget the output, mail the traceback
          to an administrator, or whatever other action may be deemed
          suitable.

      -- Attributo: traceback_limit

          The maximum number of frames to include in tracebacks output
          by the default *note log_exception(): 3eeb. method.  If
          ‘None’, all frames are included.

      -- Metodo: error_output (environ, start_response)

          This method is a WSGI application to generate an error page
          for the user.  It is only invoked if an error occurs before
          headers are sent to the client.

          This method can access the current error using
          ‘sys.exception()’, and should pass that information to
          'start_response' when calling it (as described in the «Error
          Handling» section of PEP 3333(1)).  In particular, the
          'start_response' callable should follow the *note
          StartResponse: 3eca. protocol.

          The default implementation just uses the *note error_status:
          3eee, *note error_headers: 3eef, and *note error_body: 3ef0.
          attributes to generate an output page.  Subclasses can
          override this to produce more dynamic error output.

          Note, however, that it’s not recommended from a security
          perspective to spit out diagnostics to any old user; ideally,
          you should have to do something special to enable diagnostic
          output, which is why the default implementation doesn’t
          include any.

      -- Attributo: error_status

          The HTTP status used for error responses.  This should be a
          status string as defined in PEP 3333(2); it defaults to a 500
          code and message.

      -- Attributo: error_headers

          The HTTP headers used for error responses.  This should be a
          list of WSGI response headers (‘(name, value)’ tuples), as
          described in PEP 3333(3).  The default list just sets the
          content type to ‘text/plain’.

      -- Attributo: error_body

          The error response body.  This should be an HTTP response body
          bytestring.  It defaults to the plain text, «A server error
          occurred.  Please contact the administrator.»

     Methods and attributes for PEP 3333(4)’s «Optional
     Platform-Specific File Handling» feature:

      -- Attributo: wsgi_file_wrapper

          A ‘wsgi.file_wrapper’ factory, compatible with *note
          wsgiref.types.FileWrapper: 3ec4, or ‘None’.  The default value
          of this attribute is the *note wsgiref.util.FileWrapper: 940.
          class.

      -- Metodo: sendfile ()

          Override to implement platform-specific file transmission.
          This method is called only if the application’s return value
          is an instance of the class specified by the *note
          wsgi_file_wrapper: 3eea. attribute.  It should return a true
          value if it was able to successfully transmit the file, so
          that the default transmission code will not be executed.  The
          default implementation of this method just returns a false
          value.

     Miscellaneous methods and attributes:

      -- Attributo: origin_server

          This attribute should be set to a true value if the handler’s
          *note _write(): 3edd. and *note _flush(): 3ede. are being used
          to communicate directly to the client, rather than via a
          CGI-like gateway protocol that wants the HTTP status in a
          special ‘Status:’ header.

          This attribute’s default value is true in *note BaseHandler:
          1dbb, but false in *note BaseCGIHandler: 3ed7. and *note
          CGIHandler: 3ed6.

      -- Attributo: http_version

          If *note origin_server: 3ee7. is true, this string attribute
          is used to set the HTTP version of the response set to the
          client.  It defaults to ‘"1.0"’.

 -- Funzione: wsgiref.handlers.read_environ ()

     Transcode CGI variables from ‘os.environ’ to PEP 3333(5) «bytes in
     unicode» strings, returning a new dictionary.  This function is
     used by *note CGIHandler: 3ed6. and *note IISCGIHandler: 3ed8. in
     place of directly using ‘os.environ’, which is not necessarily
     WSGI-compliant on all platforms and web servers using Python 3 –
     specifically, ones where the OS’s actual environment is Unicode
     (i.e.  Windows), or ones where the environment is bytes, but the
     system encoding used by Python to decode it is anything other than
     ISO-8859-1 (e.g.  Unix systems using UTF-8).

     If you are implementing a CGI-based handler of your own, you
     probably want to use this routine instead of just copying values
     out of ‘os.environ’ directly.

     Added in version 3.2.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3333/

   (2) https://peps.python.org/pep-3333/

   (3) https://peps.python.org/pep-3333/

   (4) https://peps.python.org/pep-3333/

   (5) https://peps.python.org/pep-3333/


File: python.info,  Node: wsgiref types – WSGI types for static type checking,  Next: Examples<26>,  Prev: wsgiref handlers – server/gateway base classes,  Up: wsgiref — WSGI Utilities and Reference Implementation

5.22.2.6 ‘wsgiref.types’ – WSGI types for static type checking
..............................................................

This module provides various types for static type checking as described
in PEP 3333(1).

Added in version 3.11.

 -- Classe: wsgiref.types.StartResponse

     A *note typing.Protocol: 56b. describing start_response()(2)
     callables ( PEP 3333(3)).

 -- Dati: wsgiref.types.WSGIEnvironment

     A type alias describing a WSGI environment dictionary.

 -- Dati: wsgiref.types.WSGIApplication

     A type alias describing a WSGI application callable.

 -- Classe: wsgiref.types.InputStream

     A *note typing.Protocol: 56b. describing a WSGI Input Stream(4).

 -- Classe: wsgiref.types.ErrorStream

     A *note typing.Protocol: 56b. describing a WSGI Error Stream(5).

 -- Classe: wsgiref.types.FileWrapper

     A *note typing.Protocol: 56b. describing a file wrapper(6).  See
     *note wsgiref.util.FileWrapper: 940. for a concrete implementation
     of this protocol.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3333/

   (2) https://peps.python.org/pep-3333/#the-start-response-callable

   (3) https://peps.python.org/pep-3333/

   (4) https://peps.python.org/pep-3333/#input-and-error-streams

   (5) https://peps.python.org/pep-3333/#input-and-error-streams

   (6) 
https://peps.python.org/pep-3333/#optional-platform-specific-file-handling


File: python.info,  Node: Examples<26>,  Prev: wsgiref types – WSGI types for static type checking,  Up: wsgiref — WSGI Utilities and Reference Implementation

5.22.2.7 Examples
.................

This is a working «Hello World» WSGI application, where the
'start_response' callable should follow the *note StartResponse: 3eca.
protocol:

     """
     Every WSGI application must have an application object - a callable
     object that accepts two arguments. For that purpose, we're going to
     use a function (note that you're not limited to a function, you can
     use a class for example). The first argument passed to the function
     is a dictionary containing CGI-style environment variables and the
     second variable is the callable object.
     """
     from wsgiref.simple_server import make_server


     def hello_world_app(environ, start_response):
         status = "200 OK"  # HTTP Status
         headers = [("Content-type", "text/plain; charset=utf-8")]  # HTTP Headers
         start_response(status, headers)

         # The returned object is going to be printed
         return [b"Hello World"]

     with make_server("", 8000, hello_world_app) as httpd:
         print("Serving on port 8000...")

         # Serve until process is killed
         httpd.serve_forever()

Example of a WSGI application serving the current directory, accept
optional directory and port number (default: 8000) on the command line:

     """
     Small wsgiref based web server. Takes a path to serve from and an
     optional port number (defaults to 8000), then tries to serve files.
     MIME types are guessed from the file names, 404 errors are raised
     if the file is not found.
     """
     import mimetypes
     import os
     import sys
     from wsgiref import simple_server, util


     def app(environ, respond):
         # Get the file name and MIME type
         fn = os.path.join(path, environ["PATH_INFO"][1:])
         if "." not in fn.split(os.path.sep)[-1]:
             fn = os.path.join(fn, "index.html")
         mime_type = mimetypes.guess_file_type(fn)[0]

         # Return 200 OK if file exists, otherwise 404 Not Found
         if os.path.exists(fn):
             respond("200 OK", [("Content-Type", mime_type)])
             return util.FileWrapper(open(fn, "rb"))
         else:
             respond("404 Not Found", [("Content-Type", "text/plain")])
             return [b"not found"]


     if __name__ == "__main__":
         # Get the path and port from command-line arguments
         path = sys.argv[1] if len(sys.argv) > 1 else os.getcwd()
         port = int(sys.argv[2]) if len(sys.argv) > 2 else 8000

         # Make and start the server until control-c
         httpd = simple_server.make_server("", port, app)
         print(f"Serving {path} on port {port}, control-C to stop")
         try:
             httpd.serve_forever()
         except KeyboardInterrupt:
             print("Shutting down.")
             httpd.server_close()


File: python.info,  Node: urllib — URL handling modules,  Next: urllib request — Extensible library for opening URLs,  Prev: wsgiref — WSGI Utilities and Reference Implementation,  Up: Internet Protocols and Support

5.22.3 ‘urllib’ — URL handling modules
--------------------------------------

'Source code:' Lib/urllib/(1)

__________________________________________________________________

‘urllib’ is a package that collects several modules for working with
URLs:

   * *note urllib.request: 111. for opening and reading URLs

   * *note urllib.error: 10f. containing the exceptions raised by *note
     urllib.request: 111.

   * *note urllib.parse: 110. for parsing URLs

   * *note urllib.robotparser: 113. for parsing ‘robots.txt’ files

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/urllib/


File: python.info,  Node: urllib request — Extensible library for opening URLs,  Next: urllib response — Response classes used by urllib,  Prev: urllib — URL handling modules,  Up: Internet Protocols and Support

5.22.4 ‘urllib.request’ — Extensible library for opening URLs
-------------------------------------------------------------

'Source code:' Lib/urllib/request.py(1)

__________________________________________________________________

The *note urllib.request: 111. module defines functions and classes
which help in opening URLs (mostly HTTP) in a complex world — basic and
digest authentication, redirections, cookies and more.

Vedi anche
..........

The Requests package(2) is recommended for a higher-level HTTP client
interface.

     Avvertimento: On macOS it is unsafe to use this module in programs
     using *note os.fork(): 4b6. because the *note getproxies(): 3efc.
     implementation for macOS uses a higher-level system API. Set the
     environment variable ‘no_proxy’ to ‘*’ to avoid this problem (e.g.
     ‘os.environ["no_proxy"] = "*"’).

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

The *note urllib.request: 111. module defines the following functions:

 -- Funzione: urllib.request.urlopen (url, data=None[, timeout], *,
          context=None)

     Open 'url', which can be either a string containing a valid,
     properly encoded URL, or a *note Request: 11da. object.

     'data' must be an object specifying additional data to be sent to
     the server, or ‘None’ if no such data is needed.  See *note
     Request: 11da. for details.

     urllib.request module uses HTTP/1.1 and includes ‘Connection:close’
     header in its HTTP requests.

     The optional 'timeout' parameter specifies a timeout in seconds for
     blocking operations like the connection attempt (if not specified,
     the global default timeout setting will be used).  This actually
     only works for HTTP, HTTPS and FTP connections.

     If 'context' is specified, it must be a *note ssl.SSLContext: 357.
     instance describing the various SSL options.  See *note
     HTTPSConnection: d38. for more details.

     This function always returns an object which can work as a *note
     context manager: 1e1. and has the properties 'url', 'headers', and
     'status'.  See *note urllib.response.addinfourl: 3efd. for more
     detail on these properties.

     For HTTP and HTTPS URLs, this function returns a *note
     http.client.HTTPResponse: 12d6. object slightly modified.  In
     addition to the three new methods above, the msg attribute contains
     the same information as the *note reason: 3efe. attribute — the
     reason phrase returned by server — instead of the response headers
     as it is specified in the documentation for *note HTTPResponse:
     12d6.

     For FTP, file, and data URLs, this function returns a *note
     urllib.response.addinfourl: 3efd. object.

     Raises *note URLError: 2be. on protocol errors.

     Note that ‘None’ may be returned if no handler handles the request
     (though the default installed global *note OpenerDirector: 3eff.
     uses *note UnknownHandler: 3f00. to ensure this never happens).

     In addition, if proxy settings are detected (for example, when a
     ‘*_proxy’ environment variable like ‘http_proxy’ is set), *note
     ProxyHandler: 1d9d. is default installed and makes sure the
     requests are handled through the proxy.

     The legacy ‘urllib.urlopen’ function from Python 2.6 and earlier
     has been discontinued; *note urllib.request.urlopen(): 307.
     corresponds to the old ‘urllib2.urlopen’.  Proxy handling, which
     was done by passing a dictionary parameter to ‘urllib.urlopen’, can
     be obtained by using *note ProxyHandler: 1d9d. objects.

     The default opener raises an *note auditing event: 1c56.
     ‘urllib.Request’ with arguments ‘fullurl’, ‘data’, ‘headers’,
     ‘method’ taken from the request object.

     Cambiato nella versione 3.2: 'cafile' and 'capath' were added.

     HTTPS virtual hosts are now supported if possible (that is, if
     *note ssl.HAS_SNI: 39bc. is true).

     'data' can be an iterable object.

     Cambiato nella versione 3.3: 'cadefault' was added.

     Cambiato nella versione 3.4.3: 'context' was added.

     Cambiato nella versione 3.10: HTTPS connection now send an ALPN
     extension with protocol indicator ‘http/1.1’ when no 'context' is
     given.  Custom 'context' should set ALPN protocols with *note
     set_alpn_protocols(): 1066.

     Cambiato nella versione 3.13: Remove 'cafile', 'capath' and
     'cadefault' parameters: use the 'context' parameter instead.

 -- Funzione: urllib.request.install_opener (opener)

     Install an *note OpenerDirector: 3eff. instance as the default
     global opener.  Installing an opener is only necessary if you want
     urlopen to use that opener; otherwise, simply call *note
     OpenerDirector.open(): 11de. instead of *note urlopen(): 307.  The
     code does not check for a real *note OpenerDirector: 3eff, and any
     class with the appropriate interface will work.

 -- Funzione: urllib.request.build_opener ([handler, ...])

     Return an *note OpenerDirector: 3eff. instance, which chains the
     handlers in the order given.  'handler's can be either instances of
     *note BaseHandler: 3f02, or subclasses of *note BaseHandler: 3f02.
     (in which case it must be possible to call the constructor without
     any parameters).  Instances of the following classes will be in
     front of the 'handler's, unless the 'handler's contain them,
     instances of them or subclasses of them: *note ProxyHandler: 1d9d.
     (if proxy settings are detected), *note UnknownHandler: 3f00, *note
     HTTPHandler: efa, *note HTTPDefaultErrorHandler: 3f03, *note
     HTTPRedirectHandler: 3f04, *note FTPHandler: 3f05, *note
     FileHandler: 3f06, *note HTTPErrorProcessor: 3f07.

     If the Python installation has SSL support (i.e., if the *note ssl:
     d5. module can be imported), *note HTTPSHandler: 142b. will also be
     added.

     A *note BaseHandler: 3f02. subclass may also change its
     ‘handler_order’ attribute to modify its position in the handlers
     list.

 -- Funzione: urllib.request.pathname2url (path, *, add_scheme=False)

     Convert the given local path to a ‘file:’ URL. This function uses
     *note quote(): d9e. function to encode the path.

     If 'add_scheme' is false (the default), the return value omits the
     ‘file:’ scheme prefix.  Set 'add_scheme' to true to return a
     complete URL.

     This example shows the function being used on Windows:

          >>> from urllib.request import pathname2url
          >>> path = 'C:\\Program Files'
          >>> pathname2url(path, add_scheme=True)
          'file:///C:/Program%20Files'

     Cambiato nella versione 3.14: Windows drive letters are no longer
     converted to uppercase, and ‘:’ characters not following a drive
     letter no longer cause an *note OSError: 2c0. exception to be
     raised on Windows.

     Cambiato nella versione 3.14: Paths beginning with a slash are
     converted to URLs with authority sections.  For example, the path
     ‘/etc/hosts’ is converted to the URL ‘///etc/hosts’.

     Cambiato nella versione 3.14: The 'add_scheme' parameter was added.

 -- Funzione: urllib.request.url2pathname (url, *, require_scheme=False,
          resolve_host=False)

     Convert the given ‘file:’ URL to a local path.  This function uses
     *note unquote(): 1ae3. to decode the URL.

     If 'require_scheme' is false (the default), the given value should
     omit a ‘file:’ scheme prefix.  If 'require_scheme' is set to true,
     the given value should include the prefix; a *note URLError: 2be.
     is raised if it doesn’t.

     The URL authority is discarded if it is empty, ‘localhost’, or the
     local hostname.  Otherwise, if 'resolve_host' is set to true, the
     authority is resolved using *note socket.gethostbyname(): 397c. and
     discarded if it matches a local IP address (as per RFC 8089 §3(3)).
     If the authority is still unhandled, then on Windows a UNC path is
     returned, and on other platforms a *note URLError: 2be. is raised.

     This example shows the function being used on Windows:

          >>> from urllib.request import url2pathname
          >>> url = 'file:///C:/Program%20Files'
          >>> url2pathname(url, require_scheme=True)
          'C:\\Program Files'

     Cambiato nella versione 3.14: Windows drive letters are no longer
     converted to uppercase, and ‘:’ characters not following a drive
     letter no longer cause an *note OSError: 2c0. exception to be
     raised on Windows.

     Cambiato nella versione 3.14: The URL authority is discarded if it
     matches the local hostname.  Otherwise, if the authority isn’t
     empty or ‘localhost’, then on Windows a UNC path is returned (as
     before), and on other platforms a *note URLError: 2be. is raised.

     Cambiato nella versione 3.14: The URL query and fragment components
     are discarded if present.

     Cambiato nella versione 3.14: The 'require_scheme' and
     'resolve_host' parameters were added.

 -- Funzione: urllib.request.getproxies ()

     This helper function returns a dictionary of scheme to proxy server
     URL mappings.  It scans the environment for variables named
     ‘<scheme>_proxy’, in a case insensitive approach, for all operating
     systems first, and when it cannot find it, looks for proxy
     information from System Configuration for macOS and Windows Systems
     Registry for Windows.  If both lowercase and uppercase environment
     variables exist (and disagree), lowercase is preferred.

          Nota: If the environment variable ‘REQUEST_METHOD’ is set,
          which usually indicates your script is running in a CGI
          environment, the environment variable ‘HTTP_PROXY’ (uppercase
          ‘_PROXY’) will be ignored.  This is because that variable can
          be injected by a client using the «Proxy:» HTTP header.  If
          you need to use an HTTP proxy in a CGI environment, either use
          ‘ProxyHandler’ explicitly, or make sure the variable name is
          in lowercase (or at least the ‘_proxy’ suffix).

The following classes are provided:

 -- Classe: urllib.request.Request (url, data=None, headers={},
          origin_req_host=None, unverifiable=False, method=None)

     This class is an abstraction of a URL request.

     'url' should be a string containing a valid, properly encoded URL.

     'data' must be an object specifying additional data to send to the
     server, or ‘None’ if no such data is needed.  Currently HTTP
     requests are the only ones that use 'data'.  The supported object
     types include bytes, file-like objects, and iterables of bytes-like
     objects.  If no ‘Content-Length’ nor ‘Transfer-Encoding’ header
     field has been provided, *note HTTPHandler: efa. will set these
     headers according to the type of 'data'.  ‘Content-Length’ will be
     used to send bytes objects, while ‘Transfer-Encoding: chunked’ as
     specified in RFC 7230(4), Section 3.3.1 will be used to send files
     and other iterables.

     For an HTTP POST request method, 'data' should be a buffer in the
     standard ‘application/x-www-form-urlencoded’ format.  The *note
     urllib.parse.urlencode(): 1097. function takes a mapping or
     sequence of 2-tuples and returns an ASCII string in this format.
     It should be encoded to bytes before being used as the 'data'
     parameter.

     'headers' should be a dictionary, and will be treated as if *note
     add_header(): 3f08. was called with each key and value as
     arguments.  This is often used to «spoof» the ‘User-Agent’ header
     value, which is used by a browser to identify itself – some HTTP
     servers only allow requests coming from common browsers as opposed
     to scripts.  For example, Mozilla Firefox may identify itself as
     ‘"Mozilla/5.0 (X11; U; Linux i686) Gecko/20071127
     Firefox/2.0.0.11"’, while *note urllib: 10e.’s default user agent
     string is ‘"Python-urllib/2.6"’ (on Python 2.6).  All header keys
     are sent in camel case.

     An appropriate ‘Content-Type’ header should be included if the
     'data' argument is present.  If this header has not been provided
     and 'data' is not ‘None’, ‘Content-Type:
     application/x-www-form-urlencoded’ will be added as a default.

     The next two arguments are only of interest for correct handling of
     third-party HTTP cookies:

     'origin_req_host' should be the request-host of the origin
     transaction, as defined by RFC 2965(5).  It defaults to
     ‘http.cookiejar.request_host(self)’.  This is the host name or IP
     address of the original request that was initiated by the user.
     For example, if the request is for an image in an HTML document,
     this should be the request-host of the request for the page
     containing the image.

     'unverifiable' should indicate whether the request is unverifiable,
     as defined by RFC 2965(6).  It defaults to ‘False’.  An
     unverifiable request is one whose URL the user did not have the
     option to approve.  For example, if the request is for an image in
     an HTML document, and the user had no option to approve the
     automatic fetching of the image, this should be true.

     'method' should be a string that indicates the HTTP request method
     that will be used (e.g.  ‘'HEAD'’).  If provided, its value is
     stored in the *note method: 11db. attribute and is used by *note
     get_method(): 1371.  The default is ‘'GET'’ if 'data' is ‘None’ or
     ‘'POST'’ otherwise.  Subclasses may indicate a different default
     method by setting the *note method: 11db. attribute in the class
     itself.

          Nota: The request will not work as expected if the data object
          is unable to deliver its content more than once (e.g.  a file
          or an iterable that can produce the content only once) and the
          request is retried for HTTP redirects or authentication.  The
          'data' is sent to the HTTP server right away after the
          headers.  There is no support for a 100-continue expectation
          in the library.

     Cambiato nella versione 3.3: *note Request.method: 11db. argument
     is added to the Request class.

     Cambiato nella versione 3.4: Default *note Request.method: 11db.
     may be indicated at the class level.

     Cambiato nella versione 3.6: Do not raise an error if the
     ‘Content-Length’ has not been provided and 'data' is neither ‘None’
     nor a bytes object.  Fall back to use chunked transfer encoding
     instead.

 -- Classe: urllib.request.OpenerDirector

     The *note OpenerDirector: 3eff. class opens URLs via *note
     BaseHandler: 3f02.s chained together.  It manages the chaining of
     handlers, and recovery from errors.

 -- Classe: urllib.request.BaseHandler

     This is the base class for all registered handlers — and handles
     only the simple mechanics of registration.

 -- Classe: urllib.request.HTTPDefaultErrorHandler

     A class which defines a default handler for HTTP error responses;
     all responses are turned into *note HTTPError: 11e0. exceptions.

 -- Classe: urllib.request.HTTPRedirectHandler

     A class to handle redirections.

 -- Classe: urllib.request.HTTPCookieProcessor (cookiejar=None)

     A class to handle HTTP Cookies.

 -- Classe: urllib.request.ProxyHandler (proxies=None)

     Cause requests to go through a proxy.  If 'proxies' is given, it
     must be a dictionary mapping protocol names to URLs of proxies.
     The default is to read the list of proxies from the environment
     variables ‘<protocol>_proxy’.  If no proxy environment variables
     are set, then in a Windows environment proxy settings are obtained
     from the registry’s Internet Settings section, and in a macOS
     environment proxy information is retrieved from the System
     Configuration Framework.

     To disable autodetected proxy pass an empty dictionary.

     The ‘no_proxy’ environment variable can be used to specify hosts
     which shouldn’t be reached via proxy; if set, it should be a
     comma-separated list of hostname suffixes, optionally with ‘:port’
     appended, for example ‘cern.ch,ncsa.uiuc.edu,some.host:8080’.

          Nota: ‘HTTP_PROXY’ will be ignored if a variable
          ‘REQUEST_METHOD’ is set; see the documentation on *note
          getproxies(): 3efc.

 -- Classe: urllib.request.HTTPPasswordMgr

     Keep a database of ‘(realm, uri) -> (user, password)’ mappings.

 -- Classe: urllib.request.HTTPPasswordMgrWithDefaultRealm

     Keep a database of ‘(realm, uri) -> (user, password)’ mappings.  A
     realm of ‘None’ is considered a catch-all realm, which is searched
     if no other realm fits.

 -- Classe: urllib.request.HTTPPasswordMgrWithPriorAuth

     A variant of *note HTTPPasswordMgrWithDefaultRealm: 3f0b. that also
     has a database of ‘uri -> is_authenticated’ mappings.  Can be used
     by a BasicAuth handler to determine when to send authentication
     credentials immediately instead of waiting for a ‘401’ response
     first.

     Added in version 3.5.

 -- Classe: urllib.request.AbstractBasicAuthHandler (password_mgr=None)

     This is a mixin class that helps with HTTP authentication, both to
     the remote host and to a proxy.  'password_mgr', if given, should
     be something that is compatible with *note HTTPPasswordMgr: 3f0a.;
     refer to section *note HTTPPasswordMgr Objects: 3f0c. for
     information on the interface that must be supported.  If
     'passwd_mgr' also provides ‘is_authenticated’ and
     ‘update_authenticated’ methods (see *note
     HTTPPasswordMgrWithPriorAuth Objects: 3f0d.), then the handler will
     use the ‘is_authenticated’ result for a given URI to determine
     whether or not to send authentication credentials with the request.
     If ‘is_authenticated’ returns ‘True’ for the URI, credentials are
     sent.  If ‘is_authenticated’ is ‘False’, credentials are not sent,
     and then if a ‘401’ response is received the request is re-sent
     with the authentication credentials.  If authentication succeeds,
     ‘update_authenticated’ is called to set ‘is_authenticated’ ‘True’
     for the URI, so that subsequent requests to the URI or any of its
     super-URIs will automatically include the authentication
     credentials.

     Added in version 3.5: Added ‘is_authenticated’ support.

 -- Classe: urllib.request.HTTPBasicAuthHandler (password_mgr=None)

     Handle authentication with the remote host.  'password_mgr', if
     given, should be something that is compatible with *note
     HTTPPasswordMgr: 3f0a.; refer to section *note HTTPPasswordMgr
     Objects: 3f0c. for information on the interface that must be
     supported.  HTTPBasicAuthHandler will raise a *note ValueError:
     2ec. when presented with a wrong Authentication scheme.

 -- Classe: urllib.request.ProxyBasicAuthHandler (password_mgr=None)

     Handle authentication with the proxy.  'password_mgr', if given,
     should be something that is compatible with *note HTTPPasswordMgr:
     3f0a.; refer to section *note HTTPPasswordMgr Objects: 3f0c. for
     information on the interface that must be supported.

 -- Classe: urllib.request.AbstractDigestAuthHandler (password_mgr=None)

     This is a mixin class that helps with HTTP authentication, both to
     the remote host and to a proxy.  'password_mgr', if given, should
     be something that is compatible with *note HTTPPasswordMgr: 3f0a.;
     refer to section *note HTTPPasswordMgr Objects: 3f0c. for
     information on the interface that must be supported.

     Cambiato nella versione 3.14: Added support for HTTP digest
     authentication algorithm ‘SHA-256’.

 -- Classe: urllib.request.HTTPDigestAuthHandler (password_mgr=None)

     Handle authentication with the remote host.  'password_mgr', if
     given, should be something that is compatible with *note
     HTTPPasswordMgr: 3f0a.; refer to section *note HTTPPasswordMgr
     Objects: 3f0c. for information on the interface that must be
     supported.  When both Digest Authentication Handler and Basic
     Authentication Handler are both added, Digest Authentication is
     always tried first.  If the Digest Authentication returns a 40x
     response again, it is sent to Basic Authentication handler to
     Handle.  This Handler method will raise a *note ValueError: 2ec.
     when presented with an authentication scheme other than Digest or
     Basic.

     Cambiato nella versione 3.3: Raise *note ValueError: 2ec. on
     unsupported Authentication Scheme.

 -- Classe: urllib.request.ProxyDigestAuthHandler (password_mgr=None)

     Handle authentication with the proxy.  'password_mgr', if given,
     should be something that is compatible with *note HTTPPasswordMgr:
     3f0a.; refer to section *note HTTPPasswordMgr Objects: 3f0c. for
     information on the interface that must be supported.

 -- Classe: urllib.request.HTTPHandler

     A class to handle opening of HTTP URLs.

 -- Classe: urllib.request.HTTPSHandler (debuglevel=0, context=None,
          check_hostname=None)

     A class to handle opening of HTTPS URLs.  'context' and
     'check_hostname' have the same meaning as in *note
     http.client.HTTPSConnection: d38.

     Cambiato nella versione 3.2: 'context' and 'check_hostname' were
     added.

 -- Classe: urllib.request.FileHandler

     Open local files.

 -- Classe: urllib.request.DataHandler

     Open data URLs.

     Added in version 3.4.

 -- Classe: urllib.request.FTPHandler

     Open FTP URLs.

 -- Classe: urllib.request.CacheFTPHandler

     Open FTP URLs, keeping a cache of open FTP connections to minimize
     delays.

 -- Classe: urllib.request.UnknownHandler

     A catch-all class to handle unknown URLs.

 -- Classe: urllib.request.HTTPErrorProcessor

     Process HTTP error responses.

* Menu:

* Request Objects::
* OpenerDirector Objects::
* BaseHandler Objects::
* HTTPRedirectHandler Objects::
* HTTPCookieProcessor Objects::
* ProxyHandler Objects::
* HTTPPasswordMgr Objects::
* HTTPPasswordMgrWithPriorAuth Objects::
* AbstractBasicAuthHandler Objects::
* HTTPBasicAuthHandler Objects::
* ProxyBasicAuthHandler Objects::
* AbstractDigestAuthHandler Objects::
* HTTPDigestAuthHandler Objects::
* ProxyDigestAuthHandler Objects::
* HTTPHandler Objects::
* HTTPSHandler Objects::
* FileHandler Objects::
* DataHandler Objects::
* FTPHandler Objects::
* CacheFTPHandler Objects::
* UnknownHandler Objects::
* HTTPErrorProcessor Objects::
* Examples: Examples<27>.
* Legacy interface::
* urllib.request Restrictions: urllib request Restrictions.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/urllib/request.py

   (2) https://requests.readthedocs.io/en/master/

   (3) https://datatracker.ietf.org/doc/html/rfc8089.html#section-3

   (4) https://datatracker.ietf.org/doc/html/rfc7230.html

   (5) https://datatracker.ietf.org/doc/html/rfc2965.html

   (6) https://datatracker.ietf.org/doc/html/rfc2965.html


File: python.info,  Node: Request Objects,  Next: OpenerDirector Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.1 Request Objects
........................

The following methods describe *note Request: 11da.’s public interface,
and so all may be overridden in subclasses.  It also defines several
public attributes that can be used by clients to inspect the parsed
request.

 -- Attributo: Request.full_url

     The original URL passed to the constructor.

     Cambiato nella versione 3.4.

     Request.full_url is a property with setter, getter and a deleter.
     Getting *note full_url: 11dc. returns the original request URL with
     the fragment, if it was present.

 -- Attributo: Request.type

     The URI scheme.

 -- Attributo: Request.host

     The URI authority, typically a host, but may also contain a port
     separated by a colon.

 -- Attributo: Request.origin_req_host

     The original host for the request, without port.

 -- Attributo: Request.selector

     The URI path.  If the *note Request: 11da. uses a proxy, then
     selector will be the full URL that is passed to the proxy.

 -- Attributo: Request.data

     The entity body for the request, or ‘None’ if not specified.

     Cambiato nella versione 3.4: Changing value of *note Request.data:
     11dd. now deletes «Content-Length» header if it was previously set
     or calculated.

 -- Attributo: Request.unverifiable

     boolean, indicates whether the request is unverifiable as defined
     by RFC 2965(1).

 -- Attributo: Request.method

     The HTTP request method to use.  By default its value is *note
     None: 886, which means that *note get_method(): 1371. will do its
     normal computation of the method to be used.  Its value can be set
     (thus overriding the default computation in *note get_method():
     1371.) either by providing a default value by setting it at the
     class level in a *note Request: 11da. subclass, or by passing a
     value in to the *note Request: 11da. constructor via the 'method'
     argument.

     Added in version 3.3.

     Cambiato nella versione 3.4: A default value can now be set in
     subclasses; previously it could only be set via the constructor
     argument.

 -- Metodo: Request.get_method ()

     Return a string indicating the HTTP request method.  If *note
     Request.method: 11db. is not ‘None’, return its value, otherwise
     return ‘'GET'’ if *note Request.data: 11dd. is ‘None’, or ‘'POST'’
     if it’s not.  This is only meaningful for HTTP requests.

     Cambiato nella versione 3.3: get_method now looks at the value of
     *note Request.method: 11db.

 -- Metodo: Request.add_header (key, val)

     Add another header to the request.  Headers are currently ignored
     by all handlers except HTTP handlers, where they are added to the
     list of headers sent to the server.  Note that there cannot be more
     than one header with the same name, and later calls will overwrite
     previous calls in case the 'key' collides.  Currently, this is no
     loss of HTTP functionality, since all headers which have meaning
     when used more than once have a (header-specific) way of gaining
     the same functionality using only one header.  Note that headers
     added using this method are also added to redirected requests.

 -- Metodo: Request.add_unredirected_header (key, header)

     Add a header that will not be added to a redirected request.

 -- Metodo: Request.has_header (header)

     Return whether the instance has the named header (checks both
     regular and unredirected).

 -- Metodo: Request.remove_header (header)

     Remove named header from the request instance (both from regular
     and unredirected headers).

     Added in version 3.4.

 -- Metodo: Request.get_full_url ()

     Return the URL given in the constructor.

     Cambiato nella versione 3.4.

     Returns *note Request.full_url: 11dc.

 -- Metodo: Request.set_proxy (host, type)

     Prepare the request by connecting to a proxy server.  The 'host'
     and 'type' will replace those of the instance, and the instance’s
     selector will be the original URL given in the constructor.

 -- Metodo: Request.get_header (header_name, default=None)

     Return the value of the given header.  If the header is not
     present, return the default value.

 -- Metodo: Request.header_items ()

     Return a list of tuples (header_name, header_value) of the Request
     headers.

Cambiato nella versione 3.4: The request methods add_data, has_data,
get_data, get_type, get_host, get_selector, get_origin_req_host and
is_unverifiable that were deprecated since 3.3 have been removed.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2965.html


File: python.info,  Node: OpenerDirector Objects,  Next: BaseHandler Objects,  Prev: Request Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.2 OpenerDirector Objects
...............................

*note OpenerDirector: 3eff. instances have the following methods:

 -- Metodo: OpenerDirector.add_handler (handler)

     'handler' should be an instance of *note BaseHandler: 3f02.  The
     following methods are searched, and added to the possible chains
     (note that HTTP errors are a special case).  Note that, in the
     following, 'protocol' should be replaced with the actual protocol
     to handle, for example ‘http_response()’ would be the HTTP protocol
     response handler.  Also 'type' should be replaced with the actual
     HTTP code, for example ‘http_error_404()’ would handle HTTP 404
     errors.

        * ‘<protocol>_open()’ — signal that the handler knows how to
          open 'protocol' URLs.

          See *note BaseHandler.<protocol>_open(): 3f22. for more
          information.

        * ‘http_error_<type>()’ — signal that the handler knows how to
          handle HTTP errors with HTTP error code 'type'.

          See *note BaseHandler.http_error_<nnn>(): 3f23. for more
          information.

        * ‘<protocol>_error()’ — signal that the handler knows how to
          handle errors from (non-‘http’) 'protocol'.

        * ‘<protocol>_request()’ — signal that the handler knows how to
          pre-process 'protocol' requests.

          See *note BaseHandler.<protocol>_request(): 3f24. for more
          information.

        * ‘<protocol>_response()’ — signal that the handler knows how to
          post-process 'protocol' responses.

          See *note BaseHandler.<protocol>_response(): 3f25. for more
          information.

 -- Metodo: OpenerDirector.open (url, data=None[, timeout])

     Open the given 'url' (which can be a request object or a string),
     optionally passing the given 'data'.  Arguments, return values and
     exceptions raised are the same as those of *note urlopen(): 307.
     (which simply calls the *note open(): 316. method on the currently
     installed global *note OpenerDirector: 3eff.).  The optional
     'timeout' parameter specifies a timeout in seconds for blocking
     operations like the connection attempt (if not specified, the
     global default timeout setting will be used).  The timeout feature
     actually works only for HTTP, HTTPS and FTP connections.

 -- Metodo: OpenerDirector.error (proto, *args)

     Handle an error of the given protocol.  This will call the
     registered error handlers for the given protocol with the given
     arguments (which are protocol specific).  The HTTP protocol is a
     special case which uses the HTTP response code to determine the
     specific error handler; refer to the ‘http_error_<type>()’ methods
     of the handler classes.

     Return values and exceptions raised are the same as those of *note
     urlopen(): 307.

OpenerDirector objects open URLs in three stages:

The order in which these methods are called within each stage is
determined by sorting the handler instances.

  1. Every handler with a method named like ‘<protocol>_request()’ has
     that method called to pre-process the request.

  2. Handlers with a method named like ‘<protocol>_open()’ are called to
     handle the request.  This stage ends when a handler either returns
     a non-*note None: 886. value (ie.  a response), or raises an
     exception (usually *note URLError: 2be.).  Exceptions are allowed
     to propagate.

     In fact, the above algorithm is first tried for methods named *note
     default_open(): 3f27.  If all such methods return *note None: 886,
     the algorithm is repeated for methods named like
     ‘<protocol>_open()’.  If all such methods return *note None: 886,
     the algorithm is repeated for methods named *note unknown_open():
     3f28.

     Note that the implementation of these methods may involve calls of
     the parent *note OpenerDirector: 3eff. instance’s *note open():
     11de. and *note error(): 3f26. methods.

  3. Every handler with a method named like ‘<protocol>_response()’ has
     that method called to post-process the response.


File: python.info,  Node: BaseHandler Objects,  Next: HTTPRedirectHandler Objects,  Prev: OpenerDirector Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.3 BaseHandler Objects
............................

*note BaseHandler: 3f02. objects provide a couple of methods that are
directly useful, and others that are meant to be used by derived
classes.  These are intended for direct use:

 -- Metodo: BaseHandler.add_parent (director)

     Add a director as parent.

 -- Metodo: BaseHandler.close ()

     Remove any parents.

The following attribute and methods should only be used by classes
derived from *note BaseHandler: 3f02.

     Nota: The convention has been adopted that subclasses defining
     ‘<protocol>_request()’ or ‘<protocol>_response()’ methods are named
     ‘*Processor’; all others are named ‘*Handler’.

 -- Attributo: BaseHandler.parent

     A valid *note OpenerDirector: 3eff, which can be used to open using
     a different protocol, or handle errors.

 -- Metodo: BaseHandler.default_open (req)

     This method is 'not' defined in *note BaseHandler: 3f02, but
     subclasses should define it if they want to catch all URLs.

     This method, if implemented, will be called by the parent *note
     OpenerDirector: 3eff.  It should return a file-like object as
     described in the return value of the *note open(): 11de. method of
     *note OpenerDirector: 3eff, or ‘None’.  It should raise *note
     URLError: 2be, unless a truly exceptional thing happens (for
     example, *note MemoryError: 1786. should not be mapped to *note
     URLError: 2be.).

     This method will be called before any protocol-specific open
     method.

 -- Metodo: BaseHandler.<protocol>_open(req)

     This method is 'not' defined in *note BaseHandler: 3f02, but
     subclasses should define it if they want to handle URLs with the
     given protocol.

     This method, if defined, will be called by the parent *note
     OpenerDirector: 3eff.  Return values should be the same as for
     *note default_open(): 3f27.

 -- Metodo: BaseHandler.unknown_open (req)

     This method is 'not' defined in *note BaseHandler: 3f02, but
     subclasses should define it if they want to catch all URLs with no
     specific registered handler to open it.

     This method, if implemented, will be called by the *note parent:
     3f2d. *note OpenerDirector: 3eff.  Return values should be the same
     as for *note default_open(): 3f27.

 -- Metodo: BaseHandler.http_error_default (req, fp, code, msg, hdrs)

     This method is 'not' defined in *note BaseHandler: 3f02, but
     subclasses should override it if they intend to provide a catch-all
     for otherwise unhandled HTTP errors.  It will be called
     automatically by the *note OpenerDirector: 3eff. getting the error,
     and should not normally be called in other circumstances.

     *note OpenerDirector: 3eff. will call this method with five
     positional arguments:

       1. a *note Request: 11da. object,

       2. a file-like object with the HTTP error body,

       3. the three-digit code of the error, as a string,

       4. the user-visible explanation of the code, as a string, and

       5. the headers of the error, as a mapping object.

     Return values and exceptions raised should be the same as those of
     *note urlopen(): 307.

 -- Metodo: BaseHandler.http_error_<nnn>(req, fp, code, msg, hdrs)

     'nnn' should be a three-digit HTTP error code.  This method is also
     not defined in *note BaseHandler: 3f02, but will be called, if it
     exists, on an instance of a subclass, when an HTTP error with code
     'nnn' occurs.

     Subclasses should override this method to handle specific HTTP
     errors.

     Arguments, return values and exceptions raised should be the same
     as for *note http_error_default(): 3f2e.

 -- Metodo: BaseHandler.<protocol>_request(req)

     This method is 'not' defined in *note BaseHandler: 3f02, but
     subclasses should define it if they want to pre-process requests of
     the given protocol.

     This method, if defined, will be called by the parent *note
     OpenerDirector: 3eff.  'req' will be a *note Request: 11da. object.
     The return value should be a *note Request: 11da. object.

 -- Metodo: BaseHandler.<protocol>_response(req, response)

     This method is 'not' defined in *note BaseHandler: 3f02, but
     subclasses should define it if they want to post-process responses
     of the given protocol.

     This method, if defined, will be called by the parent *note
     OpenerDirector: 3eff.  'req' will be a *note Request: 11da. object.
     'response' will be an object implementing the same interface as the
     return value of *note urlopen(): 307.  The return value should
     implement the same interface as the return value of *note
     urlopen(): 307.


File: python.info,  Node: HTTPRedirectHandler Objects,  Next: HTTPCookieProcessor Objects,  Prev: BaseHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.4 HTTPRedirectHandler Objects
....................................

     Nota: Some HTTP redirections require action from this module’s
     client code.  If this is the case, *note HTTPError: 11e0. is
     raised.  See RFC 2616(1) for details of the precise meanings of the
     various redirection codes.

     An *note HTTPError: 11e0. exception raised as a security
     consideration if the HTTPRedirectHandler is presented with a
     redirected URL which is not an HTTP, HTTPS or FTP URL.

 -- Metodo: HTTPRedirectHandler.redirect_request (req, fp, code, msg,
          hdrs, newurl)

     Return a *note Request: 11da. or ‘None’ in response to a redirect.
     This is called by the default implementations of the
     ‘http_error_30*()’ methods when a redirection is received from the
     server.  If a redirection should take place, return a new *note
     Request: 11da. to allow ‘http_error_30*()’ to perform the redirect
     to 'newurl'.  Otherwise, raise *note HTTPError: 11e0. if no other
     handler should try to handle this URL, or return ‘None’ if you
     can’t but another handler might.

          Nota: The default implementation of this method does not
          strictly follow RFC 2616(2), which says that 301 and 302
          responses to ‘POST’ requests must not be automatically
          redirected without confirmation by the user.  In reality,
          browsers do allow automatic redirection of these responses,
          changing the POST to a ‘GET’, and the default implementation
          reproduces this behavior.

 -- Metodo: HTTPRedirectHandler.http_error_301 (req, fp, code, msg,
          hdrs)

     Redirect to the ‘Location:’ or ‘URI:’ URL. This method is called by
     the parent *note OpenerDirector: 3eff. when getting an HTTP “moved
     permanently” response.

 -- Metodo: HTTPRedirectHandler.http_error_302 (req, fp, code, msg,
          hdrs)

     The same as *note http_error_301(): 3f32, but called for the
     “found” response.

 -- Metodo: HTTPRedirectHandler.http_error_303 (req, fp, code, msg,
          hdrs)

     The same as *note http_error_301(): 3f32, but called for the “see
     other” response.

 -- Metodo: HTTPRedirectHandler.http_error_307 (req, fp, code, msg,
          hdrs)

     The same as *note http_error_301(): 3f32, but called for the
     “temporary redirect” response.  It does not allow changing the
     request method from ‘POST’ to ‘GET’.

 -- Metodo: HTTPRedirectHandler.http_error_308 (req, fp, code, msg,
          hdrs)

     The same as *note http_error_301(): 3f32, but called for the
     “permanent redirect” response.  It does not allow changing the
     request method from ‘POST’ to ‘GET’.

     Added in version 3.11.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2616.html

   (2) https://datatracker.ietf.org/doc/html/rfc2616.html


File: python.info,  Node: HTTPCookieProcessor Objects,  Next: ProxyHandler Objects,  Prev: HTTPRedirectHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.5 HTTPCookieProcessor Objects
....................................

*note HTTPCookieProcessor: 3f09. instances have one attribute:

 -- Attributo: HTTPCookieProcessor.cookiejar

     The *note http.cookiejar.CookieJar: 3f3a. in which cookies are
     stored.


File: python.info,  Node: ProxyHandler Objects,  Next: HTTPPasswordMgr Objects,  Prev: HTTPCookieProcessor Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.6 ProxyHandler Objects
.............................

 -- Metodo: ProxyHandler.<protocol>_open(request)

     The *note ProxyHandler: 1d9d. will have a method
     ‘<protocol>_open()’ for every 'protocol' which has a proxy in the
     'proxies' dictionary given in the constructor.  The method will
     modify requests to go through the proxy, by calling
     ‘request.set_proxy()’, and call the next handler in the chain to
     actually execute the protocol.


File: python.info,  Node: HTTPPasswordMgr Objects,  Next: HTTPPasswordMgrWithPriorAuth Objects,  Prev: ProxyHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.7 HTTPPasswordMgr Objects
................................

These methods are available on *note HTTPPasswordMgr: 3f0a. and *note
HTTPPasswordMgrWithDefaultRealm: 3f0b. objects.

 -- Metodo: HTTPPasswordMgr.add_password (realm, uri, user, passwd)

     'uri' can be either a single URI, or a sequence of URIs.  'realm',
     'user' and 'passwd' must be strings.  This causes ‘(user, passwd)’
     to be used as authentication tokens when authentication for 'realm'
     and a super-URI of any of the given URIs is given.

 -- Metodo: HTTPPasswordMgr.find_user_password (realm, authuri)

     Get user/password for given realm and URI, if any.  This method
     will return ‘(None, None)’ if there is no matching user/password.

     For *note HTTPPasswordMgrWithDefaultRealm: 3f0b. objects, the realm
     ‘None’ will be searched if the given 'realm' has no matching
     user/password.


File: python.info,  Node: HTTPPasswordMgrWithPriorAuth Objects,  Next: AbstractBasicAuthHandler Objects,  Prev: HTTPPasswordMgr Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.8 HTTPPasswordMgrWithPriorAuth Objects
.............................................

This password manager extends *note HTTPPasswordMgrWithDefaultRealm:
3f0b. to support tracking URIs for which authentication credentials
should always be sent.

 -- Metodo: HTTPPasswordMgrWithPriorAuth.add_password (realm, uri, user,
          passwd, is_authenticated=False)

     'realm', 'uri', 'user', 'passwd' are as for *note
     HTTPPasswordMgr.add_password(): 3f3e.  'is_authenticated' sets the
     initial value of the ‘is_authenticated’ flag for the given URI or
     list of URIs.  If 'is_authenticated' is specified as ‘True’,
     'realm' is ignored.

 -- Metodo: HTTPPasswordMgrWithPriorAuth.find_user_password (realm,
          authuri)

     Same as for *note HTTPPasswordMgrWithDefaultRealm: 3f0b. objects

 -- Metodo: HTTPPasswordMgrWithPriorAuth.update_authenticated (self,
          uri, is_authenticated=False)

     Update the ‘is_authenticated’ flag for the given 'uri' or list of
     URIs.

 -- Metodo: HTTPPasswordMgrWithPriorAuth.is_authenticated (self,
          authuri)

     Returns the current state of the ‘is_authenticated’ flag for the
     given URI.


File: python.info,  Node: AbstractBasicAuthHandler Objects,  Next: HTTPBasicAuthHandler Objects,  Prev: HTTPPasswordMgrWithPriorAuth Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.9 AbstractBasicAuthHandler Objects
.........................................

 -- Metodo: AbstractBasicAuthHandler.http_error_auth_reqed (authreq,
          host, req, headers)

     Handle an authentication request by getting a user/password pair,
     and re-trying the request.  'authreq' should be the name of the
     header where the information about the realm is included in the
     request, 'host' specifies the URL and path to authenticate for,
     'req' should be the (failed) *note Request: 11da. object, and
     'headers' should be the error headers.

     'host' is either an authority (e.g.  ‘"python.org"’) or a URL
     containing an authority component (e.g.  ‘"http://python.org/"’).
     In either case, the authority must not contain a userinfo component
     (so, ‘"python.org"’ and ‘"python.org:80"’ are fine,
     ‘"joe:password@python.org"’ is not).


File: python.info,  Node: HTTPBasicAuthHandler Objects,  Next: ProxyBasicAuthHandler Objects,  Prev: AbstractBasicAuthHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.10 HTTPBasicAuthHandler Objects
......................................

 -- Metodo: HTTPBasicAuthHandler.http_error_401 (req, fp, code, msg,
          hdrs)

     Retry the request with authentication information, if available.


File: python.info,  Node: ProxyBasicAuthHandler Objects,  Next: AbstractDigestAuthHandler Objects,  Prev: HTTPBasicAuthHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.11 ProxyBasicAuthHandler Objects
.......................................

 -- Metodo: ProxyBasicAuthHandler.http_error_407 (req, fp, code, msg,
          hdrs)

     Retry the request with authentication information, if available.


File: python.info,  Node: AbstractDigestAuthHandler Objects,  Next: HTTPDigestAuthHandler Objects,  Prev: ProxyBasicAuthHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.12 AbstractDigestAuthHandler Objects
...........................................

 -- Metodo: AbstractDigestAuthHandler.http_error_auth_reqed (authreq,
          host, req, headers)

     'authreq' should be the name of the header where the information
     about the realm is included in the request, 'host' should be the
     host to authenticate to, 'req' should be the (failed) *note
     Request: 11da. object, and 'headers' should be the error headers.


File: python.info,  Node: HTTPDigestAuthHandler Objects,  Next: ProxyDigestAuthHandler Objects,  Prev: AbstractDigestAuthHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.13 HTTPDigestAuthHandler Objects
.......................................

 -- Metodo: HTTPDigestAuthHandler.http_error_401 (req, fp, code, msg,
          hdrs)

     Retry the request with authentication information, if available.


File: python.info,  Node: ProxyDigestAuthHandler Objects,  Next: HTTPHandler Objects,  Prev: HTTPDigestAuthHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.14 ProxyDigestAuthHandler Objects
........................................

 -- Metodo: ProxyDigestAuthHandler.http_error_407 (req, fp, code, msg,
          hdrs)

     Retry the request with authentication information, if available.


File: python.info,  Node: HTTPHandler Objects,  Next: HTTPSHandler Objects,  Prev: ProxyDigestAuthHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.15 HTTPHandler Objects
.............................

 -- Metodo: HTTPHandler.http_open (req)

     Send an HTTP request, which can be either GET or POST, depending on
     ‘req.data’.


File: python.info,  Node: HTTPSHandler Objects,  Next: FileHandler Objects,  Prev: HTTPHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.16 HTTPSHandler Objects
..............................

 -- Metodo: HTTPSHandler.https_open (req)

     Send an HTTPS request, which can be either GET or POST, depending
     on ‘req.data’.


File: python.info,  Node: FileHandler Objects,  Next: DataHandler Objects,  Prev: HTTPSHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.17 FileHandler Objects
.............................

 -- Metodo: FileHandler.file_open (req)

     Open the file locally, if there is no host name, or the host name
     is ‘'localhost'’.

     Cambiato nella versione 3.2: This method is applicable only for
     local hostnames.  When a remote hostname is given, a *note
     URLError: 2be. is raised.


File: python.info,  Node: DataHandler Objects,  Next: FTPHandler Objects,  Prev: FileHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.18 DataHandler Objects
.............................

 -- Metodo: DataHandler.data_open (req)

     Read a data URL. This kind of URL contains the content encoded in
     the URL itself.  The data URL syntax is specified in RFC 2397(1).
     This implementation ignores white spaces in base64 encoded data
     URLs so the URL may be wrapped in whatever source file it comes
     from.  But even though some browsers don’t mind about a missing
     padding at the end of a base64 encoded data URL, this
     implementation will raise a *note ValueError: 2ec. in that case.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2397.html


File: python.info,  Node: FTPHandler Objects,  Next: CacheFTPHandler Objects,  Prev: DataHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.19 FTPHandler Objects
............................

 -- Metodo: FTPHandler.ftp_open (req)

     Open the FTP file indicated by 'req'.  The login is always done
     with empty username and password.


File: python.info,  Node: CacheFTPHandler Objects,  Next: UnknownHandler Objects,  Prev: FTPHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.20 CacheFTPHandler Objects
.................................

*note CacheFTPHandler: 1a81. objects are *note FTPHandler: 3f05. objects
with the following additional methods:

 -- Metodo: CacheFTPHandler.setTimeout (t)

     Set timeout of connections to 't' seconds.

 -- Metodo: CacheFTPHandler.setMaxConns (m)

     Set maximum number of cached connections to 'm'.


File: python.info,  Node: UnknownHandler Objects,  Next: HTTPErrorProcessor Objects,  Prev: CacheFTPHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.21 UnknownHandler Objects
................................

 -- Metodo: UnknownHandler.unknown_open ()

     Raise a *note URLError: 2be. exception.


File: python.info,  Node: HTTPErrorProcessor Objects,  Next: Examples<27>,  Prev: UnknownHandler Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.22 HTTPErrorProcessor Objects
....................................

 -- Metodo: HTTPErrorProcessor.http_response (request, response)

     Process HTTP error responses.

     For 200 error codes, the response object is returned immediately.

     For non-200 error codes, this simply passes the job on to the
     ‘http_error_<type>()’ handler methods, via *note
     OpenerDirector.error(): 3f26.  Eventually, *note
     HTTPDefaultErrorHandler: 3f03. will raise an *note HTTPError: 11e0.
     if no other handler handles the error.

 -- Metodo: HTTPErrorProcessor.https_response (request, response)

     Process HTTPS error responses.

     The behavior is same as *note http_response(): 3f6d.


File: python.info,  Node: Examples<27>,  Next: Legacy interface,  Prev: HTTPErrorProcessor Objects,  Up: urllib request — Extensible library for opening URLs

5.22.4.23 Examples
..................

In addition to the examples below, more examples are given in *note
HOWTO Fetch Internet Resources Using The urllib Package: 3f71.

This example gets the python.org main page and displays the first 300
bytes of it:

     >>> import urllib.request
     >>> with urllib.request.urlopen('http://www.python.org/') as f:
     ...     print(f.read(300))
     ...
     b'<!doctype html>\n<!--[if lt IE 7]>   <html class="no-js ie6 lt-ie7 lt-ie8 lt-ie9">   <![endif]-->\n<!--[if IE 7]>      <html class="no-js ie7 lt-ie8 lt-ie9">          <![endif]-->\n<!--[if IE 8]>      <html class="no-js ie8 lt-ie9">

Note that urlopen returns a bytes object.  This is because there is no
way for urlopen to automatically determine the encoding of the byte
stream it receives from the HTTP server.  In general, a program will
decode the returned bytes object to string once it determines or guesses
the appropriate encoding.

The following HTML spec document,
‘https://html.spec.whatwg.org/#charset’, lists the various ways in which
an HTML or an XML document could have specified its encoding
information.

For additional information, see the W3C document:
‘https://www.w3.org/International/questions/qa-html-encoding-declarations’.

As the python.org website uses 'utf-8' encoding as specified in its meta
tag, we will use the same for decoding the bytes object:

     >>> with urllib.request.urlopen('http://www.python.org/') as f:
     ...     print(f.read(100).decode('utf-8'))
     ...
     <!doctype html>
     <!--[if lt IE 7]>   <html class="no-js ie6 lt-ie7 lt-ie8 lt-ie9">   <![endif]-->
     <!-

It is also possible to achieve the same result without using the *note
context manager: 1e1. approach:

     >>> import urllib.request
     >>> f = urllib.request.urlopen('http://www.python.org/')
     >>> try:
     ...     print(f.read(100).decode('utf-8'))
     ... finally:
     ...     f.close()
     ...
     <!doctype html>
     <!--[if lt IE 7]>   <html class="no-js ie6 lt-ie7 lt-ie8 lt-ie9">   <![endif]-->
     <!--

In the following example, we are sending a data-stream to the stdin of a
CGI and reading the data it returns to us.  Note that this example will
only work when the Python installation supports SSL.

     >>> import urllib.request
     >>> req = urllib.request.Request(url='https://localhost/cgi-bin/test.cgi',
     ...                       data=b'This data is passed to stdin of the CGI')
     >>> with urllib.request.urlopen(req) as f:
     ...     print(f.read().decode('utf-8'))
     ...
     Got Data: "This data is passed to stdin of the CGI"

The code for the sample CGI used in the above example is:

     #!/usr/bin/env python
     import sys
     data = sys.stdin.read()
     print('Content-type: text/plain\n\nGot Data: "%s"' % data)

Here is an example of doing a ‘PUT’ request using *note Request: 11da.:

     import urllib.request
     DATA = b'some data'
     req = urllib.request.Request(url='http://localhost:8080', data=DATA, method='PUT')
     with urllib.request.urlopen(req) as f:
         pass
     print(f.status)
     print(f.reason)

Use of Basic HTTP Authentication:

     import urllib.request
     # Create an OpenerDirector with support for Basic HTTP Authentication...
     auth_handler = urllib.request.HTTPBasicAuthHandler()
     auth_handler.add_password(realm='PDQ Application',
                               uri='https://mahler:8092/site-updates.py',
                               user='klem',
                               passwd='kadidd!ehopper')
     opener = urllib.request.build_opener(auth_handler)
     # ...and install it globally so it can be used with urlopen.
     urllib.request.install_opener(opener)
     with urllib.request.urlopen('http://www.example.com/login.html') as f:
         print(f.read().decode('utf-8'))

*note build_opener(): 309. provides many handlers by default, including
a *note ProxyHandler: 1d9d.  By default, *note ProxyHandler: 1d9d. uses
the environment variables named ‘<scheme>_proxy’, where ‘<scheme>’ is
the URL scheme involved.  For example, the ‘http_proxy’ environment
variable is read to obtain the HTTP proxy’s URL.

This example replaces the default *note ProxyHandler: 1d9d. with one
that uses programmatically supplied proxy URLs, and adds proxy
authorization support with *note ProxyBasicAuthHandler: 3f0f.

     proxy_handler = urllib.request.ProxyHandler({'http': 'http://www.example.com:3128/'})
     proxy_auth_handler = urllib.request.ProxyBasicAuthHandler()
     proxy_auth_handler.add_password('realm', 'host', 'username', 'password')

     opener = urllib.request.build_opener(proxy_handler, proxy_auth_handler)
     # This time, rather than install the OpenerDirector, we use it directly:
     with opener.open('http://www.example.com/login.html') as f:
        print(f.read().decode('utf-8'))

Adding HTTP headers:

Use the 'headers' argument to the *note Request: 11da. constructor, or:

     import urllib.request
     req = urllib.request.Request('http://www.example.com/')
     req.add_header('Referer', 'http://www.python.org/')
     # Customize the default User-Agent header value:
     req.add_header('User-Agent', 'urllib-example/0.1 (Contact: . . .)')
     with urllib.request.urlopen(req) as f:
         print(f.read().decode('utf-8'))

*note OpenerDirector: 3eff. automatically adds a ‘User-Agent’ header to
every *note Request: 11da.  To change this:

     import urllib.request
     opener = urllib.request.build_opener()
     opener.addheaders = [('User-agent', 'Mozilla/5.0')]
     with opener.open('http://www.example.com/') as f:
        print(f.read().decode('utf-8'))

Also, remember that a few standard headers (‘Content-Length’,
‘Content-Type’ and ‘Host’) are added when the *note Request: 11da. is
passed to *note urlopen(): 307. (or *note OpenerDirector.open(): 11de.).
Here is an example session that uses the ‘GET’ method to retrieve a URL
containing parameters:

     >>> import urllib.request
     >>> import urllib.parse
     >>> params = urllib.parse.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
     >>> url = "http://www.musi-cal.com/cgi-bin/query?%s" % params
     >>> with urllib.request.urlopen(url) as f:
     ...     print(f.read().decode('utf-8'))
     ...

The following example uses the ‘POST’ method instead.  Note that params
output from urlencode is encoded to bytes before it is sent to urlopen
as data:

     >>> import urllib.request
     >>> import urllib.parse
     >>> data = urllib.parse.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
     >>> data = data.encode('ascii')
     >>> with urllib.request.urlopen("http://requestb.in/xrbl82xr", data) as f:
     ...     print(f.read().decode('utf-8'))
     ...

The following example uses an explicitly specified HTTP proxy,
overriding environment settings:

     >>> import urllib.request
     >>> proxies = {'http': 'http://proxy.example.com:8080/'}
     >>> opener = urllib.request.build_opener(urllib.request.ProxyHandler(proxies))
     >>> with opener.open("http://www.python.org") as f:
     ...     f.read().decode('utf-8')
     ...

The following example uses no proxies at all, overriding environment
settings:

     >>> import urllib.request
     >>> opener = urllib.request.build_opener(urllib.request.ProxyHandler({}}))
     >>> with opener.open("http://www.python.org/") as f:
     ...     f.read().decode('utf-8')
     ...


File: python.info,  Node: Legacy interface,  Next: urllib request Restrictions,  Prev: Examples<27>,  Up: urllib request — Extensible library for opening URLs

5.22.4.24 Legacy interface
..........................

The following functions and classes are ported from the Python 2 module
‘urllib’ (as opposed to ‘urllib2’).  They might become deprecated at
some point in the future.

 -- Funzione: urllib.request.urlretrieve (url, filename=None,
          reporthook=None, data=None)

     Copy a network object denoted by a URL to a local file.  If the URL
     points to a local file, the object will not be copied unless
     filename is supplied.  Return a tuple ‘(filename, headers)’ where
     'filename' is the local file name under which the object can be
     found, and 'headers' is whatever the ‘info()’ method of the object
     returned by *note urlopen(): 307. returned (for a remote object).
     Exceptions are the same as for *note urlopen(): 307.

     The second argument, if present, specifies the file location to
     copy to (if absent, the location will be a tempfile with a
     generated name).  The third argument, if present, is a callable
     that will be called once on establishment of the network connection
     and once after each block read thereafter.  The callable will be
     passed three arguments; a count of blocks transferred so far, a
     block size in bytes, and the total size of the file.  The third
     argument may be ‘-1’ on older FTP servers which do not return a
     file size in response to a retrieval request.

     The following example illustrates the most common usage scenario:

          >>> import urllib.request
          >>> local_filename, headers = urllib.request.urlretrieve('http://python.org/')
          >>> html = open(local_filename)
          >>> html.close()

     If the 'url' uses the ‘http:’ scheme identifier, the optional
     'data' argument may be given to specify a ‘POST’ request (normally
     the request type is ‘GET’).  The 'data' argument must be a bytes
     object in standard ‘application/x-www-form-urlencoded’ format; see
     the *note urllib.parse.urlencode(): 1097. function.

     *note urlretrieve(): 308. will raise *note ContentTooShortError:
     3f74. when it detects that the amount of data available was less
     than the expected amount (which is the size reported by a
     'Content-Length' header).  This can occur, for example, when the
     download is interrupted.

     The 'Content-Length' is treated as a lower bound: if there’s more
     data to read, urlretrieve reads more data, but if less data is
     available, it raises the exception.

     You can still retrieve the downloaded data in this case, it is
     stored in the ‘content’ attribute of the exception instance.

     If no 'Content-Length' header was supplied, urlretrieve can not
     check the size of the data it has downloaded, and just returns it.
     In this case you just have to assume that the download was
     successful.

 -- Funzione: urllib.request.urlcleanup ()

     Cleans up temporary files that may have been left behind by
     previous calls to *note urlretrieve(): 308.


File: python.info,  Node: urllib request Restrictions,  Prev: Legacy interface,  Up: urllib request — Extensible library for opening URLs

5.22.4.25 ‘urllib.request’ Restrictions
.......................................

   * Currently, only the following protocols are supported: HTTP
     (versions 0.9 and 1.0), FTP, local files, and data URLs.

     Cambiato nella versione 3.4: Added support for data URLs.

   * The caching feature of *note urlretrieve(): 308. has been disabled
     until someone finds the time to hack proper processing of
     Expiration time headers.

   * There should be a function to query whether a particular URL is in
     the cache.

   * For backward compatibility, if a URL appears to point to a local
     file but the file can’t be opened, the URL is re-interpreted using
     the FTP protocol.  This can sometimes cause confusing error
     messages.

   * The *note urlopen(): 307. and *note urlretrieve(): 308. functions
     can cause arbitrarily long delays while waiting for a network
     connection to be set up.  This means that it is difficult to build
     an interactive web client using these functions without using
     threads.

   * The data returned by *note urlopen(): 307. or *note urlretrieve():
     308. is the raw data returned by the server.  This may be binary
     data (such as an image), plain text or (for example) HTML. The HTTP
     protocol provides type information in the reply header, which can
     be inspected by looking at the ‘Content-Type’ header.  If the
     returned data is HTML, you can use the module *note html.parser:
     71. to parse it.

   * The code handling the FTP protocol cannot differentiate between a
     file and a directory.  This can lead to unexpected behavior when
     attempting to read a URL that points to a file that is not
     accessible.  If the URL ends in a ‘/’, it is assumed to refer to a
     directory and will be handled accordingly.  But if an attempt to
     read a file leads to a 550 error (meaning the URL cannot be found
     or is not accessible, often for permission reasons), then the path
     is treated as a directory in order to handle the case when a
     directory is specified by a URL but the trailing ‘/’ has been left
     off.  This can cause misleading results when you try to fetch a
     file whose read permissions make it inaccessible; the FTP code will
     try to read it, fail with a 550 error, and then perform a directory
     listing for the unreadable file.  If fine-grained control is
     needed, consider using the *note ftplib: 62. module.


File: python.info,  Node: urllib response — Response classes used by urllib,  Next: urllib parse — Parse URLs into components,  Prev: urllib request — Extensible library for opening URLs,  Up: Internet Protocols and Support

5.22.5 ‘urllib.response’ — Response classes used by urllib
----------------------------------------------------------

The *note urllib.response: 112. module defines functions and classes
which define a minimal file-like interface, including ‘read()’ and
‘readline()’.  Functions defined by this module are used internally by
the *note urllib.request: 111. module.  The typical response object is a
*note urllib.response.addinfourl: 3efd. instance:

 -- Classe: urllib.response.addinfourl

      -- Attributo: url

          URL of the resource retrieved, commonly used to determine if a
          redirect was followed.

      -- Attributo: headers

          Returns the headers of the response in the form of an *note
          EmailMessage: 580. instance.

      -- Attributo: status

          Added in version 3.9.

          Status code returned by server.

      -- Metodo: geturl ()

          Deprecato dalla versione 3.9: Deprecated in favor of *note
          url: 18d0.

      -- Metodo: info ()

          Deprecato dalla versione 3.9: Deprecated in favor of *note
          headers: 3f77.

      -- Attributo: code

          Deprecato dalla versione 3.9: Deprecated in favor of *note
          status: 3f78.

      -- Metodo: getcode ()

          Deprecato dalla versione 3.9: Deprecated in favor of *note
          status: 3f78.


File: python.info,  Node: urllib parse — Parse URLs into components,  Next: urllib error — Exception classes raised by urllib request,  Prev: urllib response — Response classes used by urllib,  Up: Internet Protocols and Support

5.22.6 ‘urllib.parse’ — Parse URLs into components
--------------------------------------------------

'Source code:' Lib/urllib/parse.py(1)

__________________________________________________________________

This module defines a standard interface to break Uniform Resource
Locator (URL) strings up in components (addressing scheme, network
location, path etc.), to combine the components back into a URL string,
and to convert a «relative URL» to an absolute URL given a «base URL.»

The module has been designed to match the internet RFC on Relative
Uniform Resource Locators.  It supports the following URL schemes:
‘file’, ‘ftp’, ‘gopher’, ‘hdl’, ‘http’, ‘https’, ‘imap’,
‘itms-services’, ‘mailto’, ‘mms’, ‘news’, ‘nntp’, ‘prospero’, ‘rsync’,
‘rtsp’, ‘rtsps’, ‘rtspu’, ‘sftp’, ‘shttp’, ‘sip’, ‘sips’, ‘snews’,
‘svn’, ‘svn+ssh’, ‘telnet’, ‘wais’, ‘ws’, ‘wss’.

'Dettaglio dell’implementazione di CPython:' The inclusion of the
‘itms-services’ URL scheme can prevent an app from passing Apple’s App
Store review process for the macOS and iOS App Stores.  Handling for the
‘itms-services’ scheme is always removed on iOS; on macOS, it 'may' be
removed if CPython has been built with the *note
-with-app-store-compliance: 197f. option.

The *note urllib.parse: 110. module defines functions that fall into two
broad categories: URL parsing and URL quoting.  These are covered in
detail in the following sections.

This module’s functions use the deprecated term ‘netloc’ (or ‘net_loc’),
which was introduced in RFC 1808(2).  However, this term has been
obsoleted by RFC 3986(3), which introduced the term ‘authority’ as its
replacement.  The use of ‘netloc’ is continued for backward
compatibility.

* Menu:

* URL Parsing::
* URL parsing security::
* Parsing ASCII Encoded Bytes::
* Structured Parse Results::
* URL Quoting::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/urllib/parse.py

   (2) https://datatracker.ietf.org/doc/html/rfc1808.html

   (3) https://datatracker.ietf.org/doc/html/rfc3986.html


File: python.info,  Node: URL Parsing,  Next: URL parsing security,  Up: urllib parse — Parse URLs into components

5.22.6.1 URL Parsing
....................

The URL parsing functions focus on splitting a URL string into its
components, or on combining URL components into a URL string.

 -- Funzione: urllib.parse.urlparse (urlstring, scheme='',
          allow_fragments=True)

     Parse a URL into six components, returning a 6-item *note named
     tuple: 85f.  This corresponds to the general structure of a URL:
     ‘scheme://netloc/path;parameters?query#fragment’.  Each tuple item
     is a string, possibly empty.  The components are not broken up into
     smaller parts (for example, the network location is a single
     string), and % escapes are not expanded.  The delimiters as shown
     above are not part of the result, except for a leading slash in the
     'path' component, which is retained if present.  For example:

          >>> from urllib.parse import urlparse
          >>> urlparse("scheme://netloc/path;parameters?query#fragment")
          ParseResult(scheme='scheme', netloc='netloc', path='/path;parameters', params='',
                      query='query', fragment='fragment')
          >>> o = urlparse("http://docs.python.org:80/3/library/urllib.parse.html?"
          ...              "highlight=params#url-parsing")
          >>> o
          ParseResult(scheme='http', netloc='docs.python.org:80',
                      path='/3/library/urllib.parse.html', params='',
                      query='highlight=params', fragment='url-parsing')
          >>> o.scheme
          'http'
          >>> o.netloc
          'docs.python.org:80'
          >>> o.hostname
          'docs.python.org'
          >>> o.port
          80
          >>> o._replace(fragment="").geturl()
          'http://docs.python.org:80/3/library/urllib.parse.html?highlight=params'

     Following the syntax specifications in RFC 1808(1), urlparse
     recognizes a netloc only if it is properly introduced by “//”.
     Otherwise the input is presumed to be a relative URL and thus to
     start with a path component.

          >>> from urllib.parse import urlparse
          >>> urlparse('//www.cwi.nl:80/%7Eguido/Python.html')
          ParseResult(scheme='', netloc='www.cwi.nl:80', path='/%7Eguido/Python.html',
                      params='', query='', fragment='')
          >>> urlparse('www.cwi.nl/%7Eguido/Python.html')
          ParseResult(scheme='', netloc='', path='www.cwi.nl/%7Eguido/Python.html',
                      params='', query='', fragment='')
          >>> urlparse('help/Python.html')
          ParseResult(scheme='', netloc='', path='help/Python.html', params='',
                      query='', fragment='')

     The 'scheme' argument gives the default addressing scheme, to be
     used only if the URL does not specify one.  It should be the same
     type (text or bytes) as 'urlstring', except that the default value
     ‘''’ is always allowed, and is automatically converted to ‘b''’ if
     appropriate.

     If the 'allow_fragments' argument is false, fragment identifiers
     are not recognized.  Instead, they are parsed as part of the path,
     parameters or query component, and ‘fragment’ is set to the empty
     string in the return value.

     The return value is a *note named tuple: 85f, which means that its
     items can be accessed by index or as named attributes, which are:

     Attribute              Index       Value                         Value if not present
                                                                      
     ----------------------------------------------------------------------------------------------
                                                                      
     ‘scheme’               0           URL scheme specifier          'scheme' parameter
                                                                      
                                                                      
     ‘netloc’               1           Network location part         empty string
                                                                      
                                                                      
     ‘path’                 2           Hierarchical path             empty string
                                                                      
                                                                      
     ‘params’               3           Parameters for last path      empty string
                                        element                       
                                        
                                                                      
     ‘query’                4           Query component               empty string
                                                                      
                                                                      
     ‘fragment’             5           Fragment identifier           empty string
                                                                      
                                                                      
     ‘username’                         User name                     *note None: 886.
                                                                      
                                                                      
     ‘password’                         Password                      *note None: 886.
                                                                      
                                                                      
     ‘hostname’                         Host name (lower case)        *note None: 886.
                                                                      
                                                                      
     ‘port’                             Port number as integer, if    *note None: 886.
                                        present                       
                                        

     Reading the ‘port’ attribute will raise a *note ValueError: 2ec. if
     an invalid port is specified in the URL. See section *note
     Structured Parse Results: 3f81. for more information on the result
     object.

     Unmatched square brackets in the ‘netloc’ attribute will raise a
     *note ValueError: 2ec.

     Characters in the ‘netloc’ attribute that decompose under NFKC
     normalization (as used by the IDNA encoding) into any of ‘/’, ‘?’,
     ‘#’, ‘@’, or ‘:’ will raise a *note ValueError: 2ec.  If the URL is
     decomposed before parsing, no error will be raised.

     As is the case with all named tuples, the subclass has a few
     additional methods and attributes that are particularly useful.
     One such method is ‘_replace()’.  The ‘_replace()’ method will
     return a new ParseResult object replacing specified fields with new
     values.

          >>> from urllib.parse import urlparse
          >>> u = urlparse('//www.cwi.nl:80/%7Eguido/Python.html')
          >>> u
          ParseResult(scheme='', netloc='www.cwi.nl:80', path='/%7Eguido/Python.html',
                      params='', query='', fragment='')
          >>> u._replace(scheme='http')
          ParseResult(scheme='http', netloc='www.cwi.nl:80', path='/%7Eguido/Python.html',
                      params='', query='', fragment='')

          Avvertimento: *note urlparse(): 362. does not perform
          validation.  See *note URL parsing security: 3f82. for
          details.

     Cambiato nella versione 3.2: Added IPv6 URL parsing capabilities.

     Cambiato nella versione 3.3: The fragment is now parsed for all URL
     schemes (unless 'allow_fragments' is false), in accordance with RFC
     3986(2).  Previously, an allowlist of schemes that support
     fragments existed.

     Cambiato nella versione 3.6: Out-of-range port numbers now raise
     *note ValueError: 2ec, instead of returning *note None: 886.

     Cambiato nella versione 3.8: Characters that affect netloc parsing
     under NFKC normalization will now raise *note ValueError: 2ec.

 -- Funzione: urllib.parse.parse_qs (qs, keep_blank_values=False,
          strict_parsing=False, encoding='utf-8', errors='replace',
          max_num_fields=None, separator='&')

     Parse a query string given as a string argument (data of type
     ‘application/x-www-form-urlencoded’).  Data are returned as a
     dictionary.  The dictionary keys are the unique query variable
     names and the values are lists of values for each name.

     The optional argument 'keep_blank_values' is a flag indicating
     whether blank values in percent-encoded queries should be treated
     as blank strings.  A true value indicates that blanks should be
     retained as blank strings.  The default false value indicates that
     blank values are to be ignored and treated as if they were not
     included.

     The optional argument 'strict_parsing' is a flag indicating what to
     do with parsing errors.  If false (the default), errors are
     silently ignored.  If true, errors raise a *note ValueError: 2ec.
     exception.

     The optional 'encoding' and 'errors' parameters specify how to
     decode percent-encoded sequences into Unicode characters, as
     accepted by the *note bytes.decode(): ad5. method.

     The optional argument 'max_num_fields' is the maximum number of
     fields to read.  If set, then throws a *note ValueError: 2ec. if
     there are more than 'max_num_fields' fields read.

     The optional argument 'separator' is the symbol to use for
     separating the query arguments.  It defaults to ‘&’.

     Use the *note urllib.parse.urlencode(): 1097. function (with the
     ‘doseq’ parameter set to ‘True’) to convert such dictionaries into
     query strings.

     Cambiato nella versione 3.2: Add 'encoding' and 'errors'
     parameters.

     Cambiato nella versione 3.8: Added 'max_num_fields' parameter.

     Cambiato nella versione 3.10: Added 'separator' parameter with the
     default value of ‘&’.  Python versions earlier than Python 3.10
     allowed using both ‘;’ and ‘&’ as query parameter separator.  This
     has been changed to allow only a single separator key, with ‘&’ as
     the default separator.

     Deprecato dalla versione 3.14: Accepting objects with false values
     (like ‘0’ and ‘[]’) except empty strings and byte-like objects and
     ‘None’ is now deprecated.

 -- Funzione: urllib.parse.parse_qsl (qs, keep_blank_values=False,
          strict_parsing=False, encoding='utf-8', errors='replace',
          max_num_fields=None, separator='&')

     Parse a query string given as a string argument (data of type
     ‘application/x-www-form-urlencoded’).  Data are returned as a list
     of name, value pairs.

     The optional argument 'keep_blank_values' is a flag indicating
     whether blank values in percent-encoded queries should be treated
     as blank strings.  A true value indicates that blanks should be
     retained as blank strings.  The default false value indicates that
     blank values are to be ignored and treated as if they were not
     included.

     The optional argument 'strict_parsing' is a flag indicating what to
     do with parsing errors.  If false (the default), errors are
     silently ignored.  If true, errors raise a *note ValueError: 2ec.
     exception.

     The optional 'encoding' and 'errors' parameters specify how to
     decode percent-encoded sequences into Unicode characters, as
     accepted by the *note bytes.decode(): ad5. method.

     The optional argument 'max_num_fields' is the maximum number of
     fields to read.  If set, then throws a *note ValueError: 2ec. if
     there are more than 'max_num_fields' fields read.

     The optional argument 'separator' is the symbol to use for
     separating the query arguments.  It defaults to ‘&’.

     Use the *note urllib.parse.urlencode(): 1097. function to convert
     such lists of pairs into query strings.

     Cambiato nella versione 3.2: Add 'encoding' and 'errors'
     parameters.

     Cambiato nella versione 3.8: Added 'max_num_fields' parameter.

     Cambiato nella versione 3.10: Added 'separator' parameter with the
     default value of ‘&’.  Python versions earlier than Python 3.10
     allowed using both ‘;’ and ‘&’ as query parameter separator.  This
     has been changed to allow only a single separator key, with ‘&’ as
     the default separator.

 -- Funzione: urllib.parse.urlunparse (parts)

     Construct a URL from a tuple as returned by ‘urlparse()’.  The
     'parts' argument can be any six-item iterable.  This may result in
     a slightly different, but equivalent URL, if the URL that was
     parsed originally had unnecessary delimiters (for example, a ‘?’
     with an empty query; the RFC states that these are equivalent).

 -- Funzione: urllib.parse.urlsplit (urlstring, scheme='',
          allow_fragments=True)

     This is similar to *note urlparse(): 362, but does not split the
     params from the URL. This should generally be used instead of *note
     urlparse(): 362. if the more recent URL syntax allowing parameters
     to be applied to each segment of the 'path' portion of the URL (see
     RFC 2396(3)) is wanted.  A separate function is needed to separate
     the path segments and parameters.  This function returns a 5-item
     *note named tuple: 85f.:

          (addressing scheme, network location, path, query, fragment identifier).

     The return value is a *note named tuple: 85f, its items can be
     accessed by index or as named attributes:

     Attribute              Index       Value                         Value if not present
                                                                      
     --------------------------------------------------------------------------------------------
                                                                      
     ‘scheme’               0           URL scheme specifier          'scheme' parameter
                                                                      
                                                                      
     ‘netloc’               1           Network location part         empty string
                                                                      
                                                                      
     ‘path’                 2           Hierarchical path             empty string
                                                                      
                                                                      
     ‘query’                3           Query component               empty string
                                                                      
                                                                      
     ‘fragment’             4           Fragment identifier           empty string
                                                                      
                                                                      
     ‘username’                         User name                     *note None: 886.
                                                                      
                                                                      
     ‘password’                         Password                      *note None: 886.
                                                                      
                                                                      
     ‘hostname’                         Host name (lower case)        *note None: 886.
                                                                      
                                                                      
     ‘port’                             Port number as integer, if    *note None: 886.
                                        present                       
                                        

     Reading the ‘port’ attribute will raise a *note ValueError: 2ec. if
     an invalid port is specified in the URL. See section *note
     Structured Parse Results: 3f81. for more information on the result
     object.

     Unmatched square brackets in the ‘netloc’ attribute will raise a
     *note ValueError: 2ec.

     Characters in the ‘netloc’ attribute that decompose under NFKC
     normalization (as used by the IDNA encoding) into any of ‘/’, ‘?’,
     ‘#’, ‘@’, or ‘:’ will raise a *note ValueError: 2ec.  If the URL is
     decomposed before parsing, no error will be raised.

     Following some of the WHATWG spec(4) that updates RFC 3986, leading
     C0 control and space characters are stripped from the URL. ‘\n’,
     ‘\r’ and tab ‘\t’ characters are removed from the URL at any
     position.

          Avvertimento: *note urlsplit(): f3c. does not perform
          validation.  See *note URL parsing security: 3f82. for
          details.

     Cambiato nella versione 3.6: Out-of-range port numbers now raise
     *note ValueError: 2ec, instead of returning *note None: 886.

     Cambiato nella versione 3.8: Characters that affect netloc parsing
     under NFKC normalization will now raise *note ValueError: 2ec.

     Cambiato nella versione 3.10: ASCII newline and tab characters are
     stripped from the URL.

     Cambiato nella versione 3.12: Leading WHATWG C0 control and space
     characters are stripped from the URL.

 -- Funzione: urllib.parse.urlunsplit (parts)

     Combine the elements of a tuple as returned by *note urlsplit():
     f3c. into a complete URL as a string.  The 'parts' argument can be
     any five-item iterable.  This may result in a slightly different,
     but equivalent URL, if the URL that was parsed originally had
     unnecessary delimiters (for example, a ?  with an empty query; the
     RFC states that these are equivalent).

 -- Funzione: urllib.parse.urljoin (base, url, allow_fragments=True)

     Construct a full («absolute») URL by combining a «base URL»
     ('base') with another URL ('url').  Informally, this uses
     components of the base URL, in particular the addressing scheme,
     the network location and (part of) the path, to provide missing
     components in the relative URL. For example:

          >>> from urllib.parse import urljoin
          >>> urljoin('http://www.cwi.nl/%7Eguido/Python.html', 'FAQ.html')
          'http://www.cwi.nl/%7Eguido/FAQ.html'

     The 'allow_fragments' argument has the same meaning and default as
     for *note urlparse(): 362.

          Nota: If 'url' is an absolute URL (that is, it starts with
          ‘//’ or ‘scheme://’), the 'url'’s hostname and/or scheme will
          be present in the result.  For example:

               >>> urljoin('http://www.cwi.nl/%7Eguido/Python.html',
               ...         '//www.python.org/%7Eguido')
               'http://www.python.org/%7Eguido'

          If you do not want that behavior, preprocess the 'url' with
          *note urlsplit(): f3c. and *note urlunsplit(): 1926, removing
          possible 'scheme' and 'netloc' parts.

          Avvertimento: Because an absolute URL may be passed as the
          ‘url’ parameter, it is generally 'not secure' to use ‘urljoin’
          with an attacker-controlled ‘url’.  For example in,
          ‘urljoin("https://website.com/users/", username)’, if
          ‘username’ can contain an absolute URL, the result of
          ‘urljoin’ will be the absolute URL.

     Cambiato nella versione 3.5: Behavior updated to match the
     semantics defined in RFC 3986(5).

 -- Funzione: urllib.parse.urldefrag (url)

     If 'url' contains a fragment identifier, return a modified version
     of 'url' with no fragment identifier, and the fragment identifier
     as a separate string.  If there is no fragment identifier in 'url',
     return 'url' unmodified and an empty string.

     The return value is a *note named tuple: 85f, its items can be
     accessed by index or as named attributes:

     Attribute              Index       Value                         Value if not present
                                                                      
     --------------------------------------------------------------------------------------------
                                                                      
     ‘url’                  0           URL with no fragment          empty string
                                                                      
                                                                      
     ‘fragment’             1           Fragment identifier           empty string
                                                                      

     See section *note Structured Parse Results: 3f81. for more
     information on the result object.

     Cambiato nella versione 3.2: Result is a structured object rather
     than a simple 2-tuple.

 -- Funzione: urllib.parse.unwrap (url)

     Extract the url from a wrapped URL (that is, a string formatted as
     ‘<URL:scheme://host/path>’, ‘<scheme://host/path>’,
     ‘URL:scheme://host/path’ or ‘scheme://host/path’).  If 'url' is not
     a wrapped URL, it is returned without changes.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc1808.html

   (2) https://datatracker.ietf.org/doc/html/rfc3986.html

   (3) https://datatracker.ietf.org/doc/html/rfc2396.html

   (4) https://url.spec.whatwg.org/#concept-basic-url-parser

   (5) https://datatracker.ietf.org/doc/html/rfc3986.html


File: python.info,  Node: URL parsing security,  Next: Parsing ASCII Encoded Bytes,  Prev: URL Parsing,  Up: urllib parse — Parse URLs into components

5.22.6.2 URL parsing security
.............................

The *note urlsplit(): f3c. and *note urlparse(): 362. APIs do not
perform 'validation' of inputs.  They may not raise errors on inputs
that other applications consider invalid.  They may also succeed on some
inputs that might not be considered URLs elsewhere.  Their purpose is
for practical functionality rather than purity.

Instead of raising an exception on unusual input, they may instead
return some component parts as empty strings.  Or components may contain
more than perhaps they should.

We recommend that users of these APIs where the values may be used
anywhere with security implications code defensively.  Do some
verification within your code before trusting a returned component part.
Does that ‘scheme’ make sense?  Is that a sensible ‘path’?  Is there
anything strange about that ‘hostname’?  etc.

What constitutes a URL is not universally well defined.  Different
applications have different needs and desired constraints.  For instance
the living WHATWG spec(1) describes what user facing web clients such as
a web browser require.  While RFC 3986(2) is more general.  These
functions incorporate some aspects of both, but cannot be claimed
compliant with either.  The APIs and existing user code with
expectations on specific behaviors predate both standards leading us to
be very cautious about making API behavior changes.

   ---------- Footnotes ----------

   (1) https://url.spec.whatwg.org/#concept-basic-url-parser

   (2) https://datatracker.ietf.org/doc/html/rfc3986.html


File: python.info,  Node: Parsing ASCII Encoded Bytes,  Next: Structured Parse Results,  Prev: URL parsing security,  Up: urllib parse — Parse URLs into components

5.22.6.3 Parsing ASCII Encoded Bytes
....................................

The URL parsing functions were originally designed to operate on
character strings only.  In practice, it is useful to be able to
manipulate properly quoted and encoded URLs as sequences of ASCII bytes.
Accordingly, the URL parsing functions in this module all operate on
*note bytes: 192. and *note bytearray: 344. objects in addition to *note
str: 169. objects.

If *note str: 169. data is passed in, the result will also contain only
*note str: 169. data.  If *note bytes: 192. or *note bytearray: 344.
data is passed in, the result will contain only *note bytes: 192. data.

Attempting to mix *note str: 169. data with *note bytes: 192. or *note
bytearray: 344. in a single function call will result in a *note
TypeError: 198. being raised, while attempting to pass in non-ASCII byte
values will trigger *note UnicodeDecodeError: c0a.

To support easier conversion of result objects between *note str: 169.
and *note bytes: 192, all return values from URL parsing functions
provide either an ‘encode()’ method (when the result contains *note str:
169. data) or a ‘decode()’ method (when the result contains *note bytes:
192. data).  The signatures of these methods match those of the
corresponding *note str: 169. and *note bytes: 192. methods (except that
the default encoding is ‘'ascii'’ rather than ‘'utf-8'’).  Each produces
a value of a corresponding type that contains either *note bytes: 192.
data (for ‘encode()’ methods) or *note str: 169. data (for ‘decode()’
methods).

Applications that need to operate on potentially improperly quoted URLs
that may contain non-ASCII data will need to do their own decoding from
bytes to characters before invoking the URL parsing methods.

The behaviour described in this section applies only to the URL parsing
functions.  The URL quoting functions use their own rules when producing
or consuming byte sequences as detailed in the documentation of the
individual URL quoting functions.

Cambiato nella versione 3.2: URL parsing functions now accept ASCII
encoded byte sequences


File: python.info,  Node: Structured Parse Results,  Next: URL Quoting,  Prev: Parsing ASCII Encoded Bytes,  Up: urllib parse — Parse URLs into components

5.22.6.4 Structured Parse Results
.................................

The result objects from the *note urlparse(): 362, *note urlsplit():
f3c. and *note urldefrag(): 144f. functions are subclasses of the *note
tuple: 614. type.  These subclasses add the attributes listed in the
documentation for those functions, the encoding and decoding support
described in the previous section, as well as an additional method:

 -- Metodo: urllib.parse.SplitResult.geturl ()

     Return the re-combined version of the original URL as a string.
     This may differ from the original URL in that the scheme may be
     normalized to lower case and empty components may be dropped.
     Specifically, empty parameters, queries, and fragment identifiers
     will be removed.

     For *note urldefrag(): 144f. results, only empty fragment
     identifiers will be removed.  For *note urlsplit(): f3c. and *note
     urlparse(): 362. results, all noted changes will be made to the URL
     returned by this method.

     The result of this method remains unchanged if passed back through
     the original parsing function:

          >>> from urllib.parse import urlsplit
          >>> url = 'HTTP://www.Python.org/doc/#'
          >>> r1 = urlsplit(url)
          >>> r1.geturl()
          'http://www.Python.org/doc/'
          >>> r2 = urlsplit(r1.geturl())
          >>> r2.geturl()
          'http://www.Python.org/doc/'

The following classes provide the implementations of the structured
parse results when operating on *note str: 169. objects:

 -- Classe: urllib.parse.DefragResult (url, fragment)

     Concrete class for *note urldefrag(): 144f. results containing
     *note str: 169. data.  The ‘encode()’ method returns a *note
     DefragResultBytes: 3f89. instance.

     Added in version 3.2.

 -- Classe: urllib.parse.ParseResult (scheme, netloc, path, params,
          query, fragment)

     Concrete class for *note urlparse(): 362. results containing *note
     str: 169. data.  The ‘encode()’ method returns a *note
     ParseResultBytes: 3f8b. instance.

 -- Classe: urllib.parse.SplitResult (scheme, netloc, path, query,
          fragment)

     Concrete class for *note urlsplit(): f3c. results containing *note
     str: 169. data.  The ‘encode()’ method returns a *note
     SplitResultBytes: 3f8d. instance.

The following classes provide the implementations of the parse results
when operating on *note bytes: 192. or *note bytearray: 344. objects:

 -- Classe: urllib.parse.DefragResultBytes (url, fragment)

     Concrete class for *note urldefrag(): 144f. results containing
     *note bytes: 192. data.  The ‘decode()’ method returns a *note
     DefragResult: 3f88. instance.

     Added in version 3.2.

 -- Classe: urllib.parse.ParseResultBytes (scheme, netloc, path, params,
          query, fragment)

     Concrete class for *note urlparse(): 362. results containing *note
     bytes: 192. data.  The ‘decode()’ method returns a *note
     ParseResult: 3f8a. instance.

     Added in version 3.2.

 -- Classe: urllib.parse.SplitResultBytes (scheme, netloc, path, query,
          fragment)

     Concrete class for *note urlsplit(): f3c. results containing *note
     bytes: 192. data.  The ‘decode()’ method returns a *note
     SplitResult: 3f8c. instance.

     Added in version 3.2.


File: python.info,  Node: URL Quoting,  Prev: Structured Parse Results,  Up: urllib parse — Parse URLs into components

5.22.6.5 URL Quoting
....................

The URL quoting functions focus on taking program data and making it
safe for use as URL components by quoting special characters and
appropriately encoding non-ASCII text.  They also support reversing
these operations to recreate the original data from the contents of a
URL component if that task isn’t already covered by the URL parsing
functions above.

 -- Funzione: urllib.parse.quote (string, safe='/', encoding=None,
          errors=None)

     Replace special characters in 'string' using the ‘%XX’ escape.
     Letters, digits, and the characters ‘'_.-~'’ are never quoted.  By
     default, this function is intended for quoting the path section of
     a URL. The optional 'safe' parameter specifies additional ASCII
     characters that should not be quoted — its default value is ‘'/'’.

     'string' may be either a *note str: 169. or a *note bytes: 192.
     object.

     Cambiato nella versione 3.7: Moved from RFC 2396(1) to RFC 3986(2)
     for quoting URL strings.  «~» is now included in the set of
     unreserved characters.

     The optional 'encoding' and 'errors' parameters specify how to deal
     with non-ASCII characters, as accepted by the *note str.encode():
     ad4. method.  'encoding' defaults to ‘'utf-8'’.  'errors' defaults
     to ‘'strict'’, meaning unsupported characters raise a *note
     UnicodeEncodeError: 888.  'encoding' and 'errors' must not be
     supplied if 'string' is a *note bytes: 192, or a *note TypeError:
     198. is raised.

     Note that ‘quote(string, safe, encoding, errors)’ is equivalent to
     ‘quote_from_bytes(string.encode(encoding, errors), safe)’.

     Example: ‘quote('/El Niño/')’ yields ‘'/El%20Ni%C3%B1o/'’.

 -- Funzione: urllib.parse.quote_plus (string, safe='', encoding=None,
          errors=None)

     Like *note quote(): d9e, but also replace spaces with plus signs,
     as required for quoting HTML form values when building up a query
     string to go into a URL. Plus signs in the original string are
     escaped unless they are included in 'safe'.  It also does not have
     'safe' default to ‘'/'’.

     Example: ‘quote_plus('/El Niño/')’ yields ‘'%2FEl+Ni%C3%B1o%2F'’.

 -- Funzione: urllib.parse.quote_from_bytes (bytes, safe='/')

     Like *note quote(): d9e, but accepts a *note bytes: 192. object
     rather than a *note str: 169, and does not perform string-to-bytes
     encoding.

     Example: ‘quote_from_bytes(b'a&\xef')’ yields ‘'a%26%EF'’.

 -- Funzione: urllib.parse.unquote (string, encoding='utf-8',
          errors='replace')

     Replace ‘%XX’ escapes with their single-character equivalent.  The
     optional 'encoding' and 'errors' parameters specify how to decode
     percent-encoded sequences into Unicode characters, as accepted by
     the *note bytes.decode(): ad5. method.

     'string' may be either a *note str: 169. or a *note bytes: 192.
     object.

     'encoding' defaults to ‘'utf-8'’.  'errors' defaults to
     ‘'replace'’, meaning invalid sequences are replaced by a
     placeholder character.

     Example: ‘unquote('/El%20Ni%C3%B1o/')’ yields ‘'/El Niño/'’.

     Cambiato nella versione 3.9: 'string' parameter supports bytes and
     str objects (previously only str).

 -- Funzione: urllib.parse.unquote_plus (string, encoding='utf-8',
          errors='replace')

     Like *note unquote(): 1ae3, but also replace plus signs with
     spaces, as required for unquoting HTML form values.

     'string' must be a *note str: 169.

     Example: ‘unquote_plus('/El+Ni%C3%B1o/')’ yields ‘'/El Niño/'’.

 -- Funzione: urllib.parse.unquote_to_bytes (string)

     Replace ‘%XX’ escapes with their single-octet equivalent, and
     return a *note bytes: 192. object.

     'string' may be either a *note str: 169. or a *note bytes: 192.
     object.

     If it is a *note str: 169, unescaped non-ASCII characters in
     'string' are encoded into UTF-8 bytes.

     Example: ‘unquote_to_bytes('a%26%EF')’ yields ‘b'a&\xef'’.

 -- Funzione: urllib.parse.urlencode (query, doseq=False, safe='',
          encoding=None, errors=None, quote_via=quote_plus)

     Convert a mapping object or a sequence of two-element tuples, which
     may contain *note str: 169. or *note bytes: 192. objects, to a
     percent-encoded ASCII text string.  If the resultant string is to
     be used as a 'data' for POST operation with the *note urlopen():
     307. function, then it should be encoded to bytes, otherwise it
     would result in a *note TypeError: 198.

     The resulting string is a series of ‘key=value’ pairs separated by
     ‘'&'’ characters, where both 'key' and 'value' are quoted using the
     'quote_via' function.  By default, *note quote_plus(): 1450. is
     used to quote the values, which means spaces are quoted as a ‘'+'’
     character and “/” characters are encoded as ‘%2F’, which follows
     the standard for GET requests
     (‘application/x-www-form-urlencoded’).  An alternate function that
     can be passed as 'quote_via' is *note quote(): d9e, which will
     encode spaces as ‘%20’ and not encode “/” characters.  For maximum
     control of what is quoted, use ‘quote’ and specify a value for
     'safe'.

     When a sequence of two-element tuples is used as the 'query'
     argument, the first element of each tuple is a key and the second
     is a value.  The value element in itself can be a sequence and in
     that case, if the optional parameter 'doseq' evaluates to ‘True’,
     individual ‘key=value’ pairs separated by ‘'&'’ are generated for
     each element of the value sequence for the key.  The order of
     parameters in the encoded string will match the order of parameter
     tuples in the sequence.

     The 'safe', 'encoding', and 'errors' parameters are passed down to
     'quote_via' (the 'encoding' and 'errors' parameters are only passed
     when a query element is a *note str: 169.).

     To reverse this encoding process, *note parse_qs(): 31f. and *note
     parse_qsl(): 31e. are provided in this module to parse query
     strings into Python data structures.

     Refer to *note urllib examples: 3f72. to find out how the *note
     urllib.parse.urlencode(): 1097. method can be used for generating
     the query string of a URL or data for a POST request.

     Cambiato nella versione 3.2: 'query' supports bytes and string
     objects.

     Cambiato nella versione 3.5: Added the 'quote_via' parameter.

     Deprecato dalla versione 3.14: Accepting objects with false values
     (like ‘0’ and ‘[]’) except empty strings and byte-like objects and
     ‘None’ is now deprecated.

Vedi anche
..........

WHATWG(3) - URL Living standard

     Working Group for the URL Standard that defines URLs, domains, IP
     addresses, the application/x-www-form-urlencoded format, and their
     API.

RFC 3986(4) - Uniform Resource Identifiers

     This is the current standard (STD66).  Any changes to urllib.parse
     module should conform to this.  Certain deviations could be
     observed, which are mostly for backward compatibility purposes and
     for certain de-facto parsing requirements as commonly observed in
     major browsers.

RFC 2732(5) - Format for Literal IPv6 Addresses in URL’s.

     This specifies the parsing requirements of IPv6 URLs.

RFC 2396(6) - Uniform Resource Identifiers (URI): Generic Syntax

     Document describing the generic syntactic requirements for both
     Uniform Resource Names (URNs) and Uniform Resource Locators (URLs).

RFC 2368(7) - The mailto URL scheme.

     Parsing requirements for mailto URL schemes.

RFC 1808(8) - Relative Uniform Resource Locators

     This Request For Comments includes the rules for joining an
     absolute and a relative URL, including a fair number of «Abnormal
     Examples» which govern the treatment of border cases.

RFC 1738(9) - Uniform Resource Locators (URL)

     This specifies the formal syntax and semantics of absolute URLs.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2396.html

   (2) https://datatracker.ietf.org/doc/html/rfc3986.html

   (3) https://url.spec.whatwg.org/

   (4) https://datatracker.ietf.org/doc/html/rfc3986.html

   (5) https://datatracker.ietf.org/doc/html/rfc2732.html

   (6) https://datatracker.ietf.org/doc/html/rfc2396.html

   (7) https://datatracker.ietf.org/doc/html/rfc2368.html

   (8) https://datatracker.ietf.org/doc/html/rfc1808.html

   (9) https://datatracker.ietf.org/doc/html/rfc1738.html


File: python.info,  Node: urllib error — Exception classes raised by urllib request,  Next: urllib robotparser — Parser for robots txt,  Prev: urllib parse — Parse URLs into components,  Up: Internet Protocols and Support

5.22.7 ‘urllib.error’ — Exception classes raised by urllib.request
------------------------------------------------------------------

'Source code:' Lib/urllib/error.py(1)

__________________________________________________________________

The *note urllib.error: 10f. module defines the exception classes for
exceptions raised by *note urllib.request: 111.  The base exception
class is *note URLError: 2be.

The following exceptions are raised by *note urllib.error: 10f. as
appropriate:

 -- Eccezione: urllib.error.URLError

     The handlers raise this exception (or derived exceptions) when they
     run into a problem.  It is a subclass of *note OSError: 2c0.

      -- Attributo: reason

          The reason for this error.  It can be a message string or
          another exception instance.

     Cambiato nella versione 3.3: *note URLError: 2be. used to be a
     subtype of *note IOError: 1255, which is now an alias of *note
     OSError: 2c0.

 -- Eccezione: urllib.error.HTTPError (url, code, msg, hdrs, fp)

     Though being an exception (a subclass of *note URLError: 2be.), an
     *note HTTPError: 11e0. can also function as a non-exceptional
     file-like return value (the same thing that *note urlopen(): 307.
     returns).  This is useful when handling exotic HTTP errors, such as
     requests for authentication.

      -- Attributo: url

          Contains the request URL. An alias for 'filename' attribute.

      -- Attributo: code

          An HTTP status code as defined in RFC 2616(2).  This numeric
          value corresponds to a value found in the dictionary of codes
          as found in *note
          http.server.BaseHTTPRequestHandler.responses: 3f96.

      -- Attributo: reason

          This is usually a string explaining the reason for this error.
          An alias for 'msg' attribute.

      -- Attributo: headers

          The HTTP response headers for the HTTP request that caused the
          *note HTTPError: 11e0.  An alias for 'hdrs' attribute.

          Added in version 3.4.

      -- Attributo: fp

          A file-like object where the HTTP error body can be read from.

 -- Eccezione: urllib.error.ContentTooShortError (msg, content)

     This exception is raised when the *note urlretrieve(): 308.
     function detects that the amount of the downloaded data is less
     than the expected amount (given by the 'Content-Length' header).

      -- Attributo: content

          The downloaded (and supposedly truncated) data.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/urllib/error.py

   (2) https://datatracker.ietf.org/doc/html/rfc2616.html


File: python.info,  Node: urllib robotparser — Parser for robots txt,  Next: http — HTTP modules,  Prev: urllib error — Exception classes raised by urllib request,  Up: Internet Protocols and Support

5.22.8 ‘urllib.robotparser’ — Parser for robots.txt
---------------------------------------------------

'Source code:' Lib/urllib/robotparser.py(1)

__________________________________________________________________

This module provides a single class, *note RobotFileParser: efc, which
answers questions about whether or not a particular user agent can fetch
a URL on the website that published the ‘robots.txt’ file.  For more
details on the structure of ‘robots.txt’ files, see
‘http://www.robotstxt.org/orig.html’.

 -- Classe: urllib.robotparser.RobotFileParser (url='')

     This class provides methods to read, parse and answer questions
     about the ‘robots.txt’ file at 'url'.

      -- Metodo: set_url (url)

          Sets the URL referring to a ‘robots.txt’ file.

      -- Metodo: read ()

          Reads the ‘robots.txt’ URL and feeds it to the parser.

      -- Metodo: parse (lines)

          Parses the lines argument.

      -- Metodo: can_fetch (useragent, url)

          Returns ‘True’ if the 'useragent' is allowed to fetch the
          'url' according to the rules contained in the parsed
          ‘robots.txt’ file.

      -- Metodo: mtime ()

          Returns the time the ‘robots.txt’ file was last fetched.  This
          is useful for long-running web spiders that need to check for
          new ‘robots.txt’ files periodically.

      -- Metodo: modified ()

          Sets the time the ‘robots.txt’ file was last fetched to the
          current time.

      -- Metodo: crawl_delay (useragent)

          Returns the value of the ‘Crawl-delay’ parameter from
          ‘robots.txt’ for the 'useragent' in question.  If there is no
          such parameter or it doesn’t apply to the 'useragent'
          specified or the ‘robots.txt’ entry for this parameter has
          invalid syntax, return ‘None’.

          Added in version 3.6.

      -- Metodo: request_rate (useragent)

          Returns the contents of the ‘Request-rate’ parameter from
          ‘robots.txt’ as a *note named tuple: 85f.
          ‘RequestRate(requests, seconds)’.  If there is no such
          parameter or it doesn’t apply to the 'useragent' specified or
          the ‘robots.txt’ entry for this parameter has invalid syntax,
          return ‘None’.

          Added in version 3.6.

      -- Metodo: site_maps ()

          Returns the contents of the ‘Sitemap’ parameter from
          ‘robots.txt’ in the form of a *note list(): 24d.  If there is
          no such parameter or the ‘robots.txt’ entry for this parameter
          has invalid syntax, return ‘None’.

          Added in version 3.8.

The following example demonstrates basic use of the *note
RobotFileParser: efc. class:

     >>> import urllib.robotparser
     >>> rp = urllib.robotparser.RobotFileParser()
     >>> rp.set_url("http://www.musi-cal.com/robots.txt")
     >>> rp.read()
     >>> rrate = rp.request_rate("*")
     >>> rrate.requests
     3
     >>> rrate.seconds
     20
     >>> rp.crawl_delay("*")
     6
     >>> rp.can_fetch("*", "http://www.musi-cal.com/cgi-bin/search?city=San+Francisco")
     False
     >>> rp.can_fetch("*", "http://www.musi-cal.com/")
     True

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/urllib/robotparser.py


File: python.info,  Node: http — HTTP modules,  Next: http client — HTTP protocol client,  Prev: urllib robotparser — Parser for robots txt,  Up: Internet Protocols and Support

5.22.9 ‘http’ — HTTP modules
----------------------------

'Source code:' Lib/http/__init__.py(1)

__________________________________________________________________

*note http: 72. is a package that collects several modules for working
with the HyperText Transfer Protocol:

   * *note http.client: 73. is a low-level HTTP protocol client; for
     high-level URL opening use *note urllib.request: 111.

   * *note http.server: 76. contains basic HTTP server classes based on
     *note socketserver: d2.

   * *note http.cookies: 75. has utilities for implementing state
     management with cookies

   * *note http.cookiejar: 74. provides persistence of cookies

The *note http: 72. module also defines the following enums that help
you work with http related code:

 -- Classe: http.HTTPStatus

     Added in version 3.5.

     A subclass of *note enum.IntEnum: edd. that defines a set of HTTP
     status codes, reason phrases and long descriptions written in
     English.

     Usage:

          >>> from http import HTTPStatus
          >>> HTTPStatus.OK
          HTTPStatus.OK
          >>> HTTPStatus.OK == 200
          True
          >>> HTTPStatus.OK.value
          200
          >>> HTTPStatus.OK.phrase
          'OK'
          >>> HTTPStatus.OK.description
          'Request fulfilled, document follows'
          >>> list(HTTPStatus)
          [HTTPStatus.CONTINUE, HTTPStatus.SWITCHING_PROTOCOLS, ...]

* Menu:

* HTTP status codes::
* HTTP status category::
* HTTP methods::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/http/__init__.py


File: python.info,  Node: HTTP status codes,  Next: HTTP status category,  Up: http — HTTP modules

5.22.9.1 HTTP status codes
..........................

Supported, IANA-registered status codes(1) available in *note
http.HTTPStatus: afe. are:

Code        Enum Name                               Details
                                                    
----------------------------------------------------------------------------------------------------------------------------------------
                                                    
‘100’       ‘CONTINUE’                              HTTP Semantics RFC 9110(2), Section 15.2.1
                                                    
                                                    
‘101’       ‘SWITCHING_PROTOCOLS’                   HTTP Semantics RFC 9110(3), Section 15.2.2
                                                    
                                                    
‘102’       ‘PROCESSING’                            WebDAV RFC 2518(4), Section 10.1
                                                    
                                                    
‘103’       ‘EARLY_HINTS’                           An HTTP Status Code for Indicating Hints RFC 8297(5)
                                                    
                                                    
‘200’       ‘OK’                                    HTTP Semantics RFC 9110(6), Section 15.3.1
                                                    
                                                    
‘201’       ‘CREATED’                               HTTP Semantics RFC 9110(7), Section 15.3.2
                                                    
                                                    
‘202’       ‘ACCEPTED’                              HTTP Semantics RFC 9110(8), Section 15.3.3
                                                    
                                                    
‘203’       ‘NON_AUTHORITATIVE_INFORMATION’         HTTP Semantics RFC 9110(9), Section 15.3.4
                                                    
                                                    
‘204’       ‘NO_CONTENT’                            HTTP Semantics RFC 9110(10), Section 15.3.5
                                                    
                                                    
‘205’       ‘RESET_CONTENT’                         HTTP Semantics RFC 9110(11), Section 15.3.6
                                                    
                                                    
‘206’       ‘PARTIAL_CONTENT’                       HTTP Semantics RFC 9110(12), Section 15.3.7
                                                    
                                                    
‘207’       ‘MULTI_STATUS’                          WebDAV RFC 4918(13), Section 11.1
                                                    
                                                    
‘208’       ‘ALREADY_REPORTED’                      WebDAV Binding Extensions RFC 5842(14), Section 7.1 (Experimental)
                                                    
                                                    
‘226’       ‘IM_USED’                               Delta Encoding in HTTP RFC 3229(15), Section 10.4.1
                                                    
                                                    
‘300’       ‘MULTIPLE_CHOICES’                      HTTP Semantics RFC 9110(16), Section 15.4.1
                                                    
                                                    
‘301’       ‘MOVED_PERMANENTLY’                     HTTP Semantics RFC 9110(17), Section 15.4.2
                                                    
                                                    
‘302’       ‘FOUND’                                 HTTP Semantics RFC 9110(18), Section 15.4.3
                                                    
                                                    
‘303’       ‘SEE_OTHER’                             HTTP Semantics RFC 9110(19), Section 15.4.4
                                                    
                                                    
‘304’       ‘NOT_MODIFIED’                          HTTP Semantics RFC 9110(20), Section 15.4.5
                                                    
                                                    
‘305’       ‘USE_PROXY’                             HTTP Semantics RFC 9110(21), Section 15.4.6
                                                    
                                                    
‘307’       ‘TEMPORARY_REDIRECT’                    HTTP Semantics RFC 9110(22), Section 15.4.8
                                                    
                                                    
‘308’       ‘PERMANENT_REDIRECT’                    HTTP Semantics RFC 9110(23), Section 15.4.9
                                                    
                                                    
‘400’       ‘BAD_REQUEST’                           HTTP Semantics RFC 9110(24), Section 15.5.1
                                                    
                                                    
‘401’       ‘UNAUTHORIZED’                          HTTP Semantics RFC 9110(25), Section 15.5.2
                                                    
                                                    
‘402’       ‘PAYMENT_REQUIRED’                      HTTP Semantics RFC 9110(26), Section 15.5.3
                                                    
                                                    
‘403’       ‘FORBIDDEN’                             HTTP Semantics RFC 9110(27), Section 15.5.4
                                                    
                                                    
‘404’       ‘NOT_FOUND’                             HTTP Semantics RFC 9110(28), Section 15.5.5
                                                    
                                                    
‘405’       ‘METHOD_NOT_ALLOWED’                    HTTP Semantics RFC 9110(29), Section 15.5.6
                                                    
                                                    
‘406’       ‘NOT_ACCEPTABLE’                        HTTP Semantics RFC 9110(30), Section 15.5.7
                                                    
                                                    
‘407’       ‘PROXY_AUTHENTICATION_REQUIRED’         HTTP Semantics RFC 9110(31), Section 15.5.8
                                                    
                                                    
‘408’       ‘REQUEST_TIMEOUT’                       HTTP Semantics RFC 9110(32), Section 15.5.9
                                                    
                                                    
‘409’       ‘CONFLICT’                              HTTP Semantics RFC 9110(33), Section 15.5.10
                                                    
                                                    
‘410’       ‘GONE’                                  HTTP Semantics RFC 9110(34), Section 15.5.11
                                                    
                                                    
‘411’       ‘LENGTH_REQUIRED’                       HTTP Semantics RFC 9110(35), Section 15.5.12
                                                    
                                                    
‘412’       ‘PRECONDITION_FAILED’                   HTTP Semantics RFC 9110(36), Section 15.5.13
                                                    
                                                    
‘413’       ‘CONTENT_TOO_LARGE’                     HTTP Semantics RFC 9110(37), Section 15.5.14
                                                    
                                                    
‘414’       ‘URI_TOO_LONG’                          HTTP Semantics RFC 9110(38), Section 15.5.15
                                                    
                                                    
‘415’       ‘UNSUPPORTED_MEDIA_TYPE’                HTTP Semantics RFC 9110(39), Section 15.5.16
                                                    
                                                    
‘416’       ‘RANGE_NOT_SATISFIABLE’                 HTTP Semantics RFC 9110(40), Section 15.5.17
                                                    
                                                    
‘417’       ‘EXPECTATION_FAILED’                    HTTP Semantics RFC 9110(41), Section 15.5.18
                                                    
                                                    
‘418’       ‘IM_A_TEAPOT’                           HTCPCP/1.0 RFC 2324(42), Section 2.3.2
                                                    
                                                    
‘421’       ‘MISDIRECTED_REQUEST’                   HTTP Semantics RFC 9110(43), Section 15.5.20
                                                    
                                                    
‘422’       ‘UNPROCESSABLE_CONTENT’                 HTTP Semantics RFC 9110(44), Section 15.5.21
                                                    
                                                    
‘423’       ‘LOCKED’                                WebDAV RFC 4918(45), Section 11.3
                                                    
                                                    
‘424’       ‘FAILED_DEPENDENCY’                     WebDAV RFC 4918(46), Section 11.4
                                                    
                                                    
‘425’       ‘TOO_EARLY’                             Using Early Data in HTTP RFC 8470(47)
                                                    
                                                    
‘426’       ‘UPGRADE_REQUIRED’                      HTTP Semantics RFC 9110(48), Section 15.5.22
                                                    
                                                    
‘428’       ‘PRECONDITION_REQUIRED’                 Additional HTTP Status Codes RFC 6585(49)
                                                    
                                                    
‘429’       ‘TOO_MANY_REQUESTS’                     Additional HTTP Status Codes RFC 6585(50)
                                                    
                                                    
‘431’       ‘REQUEST_HEADER_FIELDS_TOO_LARGE’       Additional HTTP Status Codes RFC 6585(51)
                                                    
                                                    
‘451’       ‘UNAVAILABLE_FOR_LEGAL_REASONS’         An HTTP Status Code to Report Legal Obstacles RFC 7725(52)
                                                    
                                                    
‘500’       ‘INTERNAL_SERVER_ERROR’                 HTTP Semantics RFC 9110(53), Section 15.6.1
                                                    
                                                    
‘501’       ‘NOT_IMPLEMENTED’                       HTTP Semantics RFC 9110(54), Section 15.6.2
                                                    
                                                    
‘502’       ‘BAD_GATEWAY’                           HTTP Semantics RFC 9110(55), Section 15.6.3
                                                    
                                                    
‘503’       ‘SERVICE_UNAVAILABLE’                   HTTP Semantics RFC 9110(56), Section 15.6.4
                                                    
                                                    
‘504’       ‘GATEWAY_TIMEOUT’                       HTTP Semantics RFC 9110(57), Section 15.6.5
                                                    
                                                    
‘505’       ‘HTTP_VERSION_NOT_SUPPORTED’            HTTP Semantics RFC 9110(58), Section 15.6.6
                                                    
                                                    
‘506’       ‘VARIANT_ALSO_NEGOTIATES’               Transparent Content Negotiation in HTTP RFC 2295(59), Section 8.1 (Experimental)
                                                    
                                                    
‘507’       ‘INSUFFICIENT_STORAGE’                  WebDAV RFC 4918(60), Section 11.5
                                                    
                                                    
‘508’       ‘LOOP_DETECTED’                         WebDAV Binding Extensions RFC 5842(61), Section 7.2 (Experimental)
                                                    
                                                    
‘510’       ‘NOT_EXTENDED’                          An HTTP Extension Framework RFC 2774(62), Section 7 (Experimental)
                                                    
                                                    
‘511’       ‘NETWORK_AUTHENTICATION_REQUIRED’       Additional HTTP Status Codes RFC 6585(63), Section 6
                                                    

In order to preserve backwards compatibility, enum values are also
present in the *note http.client: 73. module in the form of constants.
The enum name is equal to the constant name (i.e.  ‘http.HTTPStatus.OK’
is also available as ‘http.client.OK’).

Cambiato nella versione 3.7: Added ‘421 MISDIRECTED_REQUEST’ status
code.

Added in version 3.8: Added ‘451 UNAVAILABLE_FOR_LEGAL_REASONS’ status
code.

Added in version 3.9: Added ‘103 EARLY_HINTS’, ‘418 IM_A_TEAPOT’ and
‘425 TOO_EARLY’ status codes.

Cambiato nella versione 3.13: Implemented RFC9110 naming for status
constants.  Old constant names are preserved for backwards
compatibility: ‘413 REQUEST_ENTITY_TOO_LARGE’, ‘414
REQUEST_URI_TOO_LONG’, ‘416 REQUESTED_RANGE_NOT_SATISFIABLE’ and ‘422
UNPROCESSABLE_ENTITY’.

   ---------- Footnotes ----------

   (1) 
https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml

   (2) https://datatracker.ietf.org/doc/html/rfc9110.html

   (3) https://datatracker.ietf.org/doc/html/rfc9110.html

   (4) https://datatracker.ietf.org/doc/html/rfc2518.html

   (5) https://datatracker.ietf.org/doc/html/rfc8297.html

   (6) https://datatracker.ietf.org/doc/html/rfc9110.html

   (7) https://datatracker.ietf.org/doc/html/rfc9110.html

   (8) https://datatracker.ietf.org/doc/html/rfc9110.html

   (9) https://datatracker.ietf.org/doc/html/rfc9110.html

   (10) https://datatracker.ietf.org/doc/html/rfc9110.html

   (11) https://datatracker.ietf.org/doc/html/rfc9110.html

   (12) https://datatracker.ietf.org/doc/html/rfc9110.html

   (13) https://datatracker.ietf.org/doc/html/rfc4918.html

   (14) https://datatracker.ietf.org/doc/html/rfc5842.html

   (15) https://datatracker.ietf.org/doc/html/rfc3229.html

   (16) https://datatracker.ietf.org/doc/html/rfc9110.html

   (17) https://datatracker.ietf.org/doc/html/rfc9110.html

   (18) https://datatracker.ietf.org/doc/html/rfc9110.html

   (19) https://datatracker.ietf.org/doc/html/rfc9110.html

   (20) https://datatracker.ietf.org/doc/html/rfc9110.html

   (21) https://datatracker.ietf.org/doc/html/rfc9110.html

   (22) https://datatracker.ietf.org/doc/html/rfc9110.html

   (23) https://datatracker.ietf.org/doc/html/rfc9110.html

   (24) https://datatracker.ietf.org/doc/html/rfc9110.html

   (25) https://datatracker.ietf.org/doc/html/rfc9110.html

   (26) https://datatracker.ietf.org/doc/html/rfc9110.html

   (27) https://datatracker.ietf.org/doc/html/rfc9110.html

   (28) https://datatracker.ietf.org/doc/html/rfc9110.html

   (29) https://datatracker.ietf.org/doc/html/rfc9110.html

   (30) https://datatracker.ietf.org/doc/html/rfc9110.html

   (31) https://datatracker.ietf.org/doc/html/rfc9110.html

   (32) https://datatracker.ietf.org/doc/html/rfc9110.html

   (33) https://datatracker.ietf.org/doc/html/rfc9110.html

   (34) https://datatracker.ietf.org/doc/html/rfc9110.html

   (35) https://datatracker.ietf.org/doc/html/rfc9110.html

   (36) https://datatracker.ietf.org/doc/html/rfc9110.html

   (37) https://datatracker.ietf.org/doc/html/rfc9110.html

   (38) https://datatracker.ietf.org/doc/html/rfc9110.html

   (39) https://datatracker.ietf.org/doc/html/rfc9110.html

   (40) https://datatracker.ietf.org/doc/html/rfc9110.html

   (41) https://datatracker.ietf.org/doc/html/rfc9110.html

   (42) https://datatracker.ietf.org/doc/html/rfc2324.html

   (43) https://datatracker.ietf.org/doc/html/rfc9110.html

   (44) https://datatracker.ietf.org/doc/html/rfc9110.html

   (45) https://datatracker.ietf.org/doc/html/rfc4918.html

   (46) https://datatracker.ietf.org/doc/html/rfc4918.html

   (47) https://datatracker.ietf.org/doc/html/rfc8470.html

   (48) https://datatracker.ietf.org/doc/html/rfc9110.html

   (49) https://datatracker.ietf.org/doc/html/rfc6585.html

   (50) https://datatracker.ietf.org/doc/html/rfc6585.html

   (51) https://datatracker.ietf.org/doc/html/rfc6585.html

   (52) https://datatracker.ietf.org/doc/html/rfc7725.html

   (53) https://datatracker.ietf.org/doc/html/rfc9110.html

   (54) https://datatracker.ietf.org/doc/html/rfc9110.html

   (55) https://datatracker.ietf.org/doc/html/rfc9110.html

   (56) https://datatracker.ietf.org/doc/html/rfc9110.html

   (57) https://datatracker.ietf.org/doc/html/rfc9110.html

   (58) https://datatracker.ietf.org/doc/html/rfc9110.html

   (59) https://datatracker.ietf.org/doc/html/rfc2295.html

   (60) https://datatracker.ietf.org/doc/html/rfc4918.html

   (61) https://datatracker.ietf.org/doc/html/rfc5842.html

   (62) https://datatracker.ietf.org/doc/html/rfc2774.html

   (63) https://datatracker.ietf.org/doc/html/rfc6585.html


File: python.info,  Node: HTTP status category,  Next: HTTP methods,  Prev: HTTP status codes,  Up: http — HTTP modules

5.22.9.2 HTTP status category
.............................

Added in version 3.12.

The enum values have several properties to indicate the HTTP status
category:

Property                 Indicates that               Details
                                                      
-------------------------------------------------------------------------------------------------
                                                      
‘is_informational’       ‘100 <= status <= 199’       HTTP Semantics RFC 9110(1), Section 15
                                                      
                                                      
‘is_success’             ‘200 <= status <= 299’       HTTP Semantics RFC 9110(2), Section 15
                                                      
                                                      
‘is_redirection’         ‘300 <= status <= 399’       HTTP Semantics RFC 9110(3), Section 15
                                                      
                                                      
‘is_client_error’        ‘400 <= status <= 499’       HTTP Semantics RFC 9110(4), Section 15
                                                      
                                                      
‘is_server_error’        ‘500 <= status <= 599’       HTTP Semantics RFC 9110(5), Section 15
                                                      

     Usage:

          >>> from http import HTTPStatus
          >>> HTTPStatus.OK.is_success
          True
          >>> HTTPStatus.OK.is_client_error
          False

 -- Classe: http.HTTPMethod

     Added in version 3.11.

     A subclass of *note enum.StrEnum: 82e. that defines a set of HTTP
     methods and descriptions written in English.

     Usage:

          >>> from http import HTTPMethod
          >>>
          >>> HTTPMethod.GET
          <HTTPMethod.GET>
          >>> HTTPMethod.GET == 'GET'
          True
          >>> HTTPMethod.GET.value
          'GET'
          >>> HTTPMethod.GET.description
          'Retrieve the target.'
          >>> list(HTTPMethod)
          [<HTTPMethod.CONNECT>,
           <HTTPMethod.DELETE>,
           <HTTPMethod.GET>,
           <HTTPMethod.HEAD>,
           <HTTPMethod.OPTIONS>,
           <HTTPMethod.PATCH>,
           <HTTPMethod.POST>,
           <HTTPMethod.PUT>,
           <HTTPMethod.TRACE>]

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc9110.html

   (2) https://datatracker.ietf.org/doc/html/rfc9110.html

   (3) https://datatracker.ietf.org/doc/html/rfc9110.html

   (4) https://datatracker.ietf.org/doc/html/rfc9110.html

   (5) https://datatracker.ietf.org/doc/html/rfc9110.html


File: python.info,  Node: HTTP methods,  Prev: HTTP status category,  Up: http — HTTP modules

5.22.9.3 HTTP methods
.....................

Supported, IANA-registered methods(1) available in *note
http.HTTPMethod: 3fa9. are:

Method          Enum Name                               Details
                                                        
-------------------------------------------------------------------------------------------------------------------------------
                                                        
‘GET’           ‘GET’                                   HTTP Semantics RFC 9110(2), Section 9.3.1
                                                        
                                                        
‘HEAD’          ‘HEAD’                                  HTTP Semantics RFC 9110(3), Section 9.3.2
                                                        
                                                        
‘POST’          ‘POST’                                  HTTP Semantics RFC 9110(4), Section 9.3.3
                                                        
                                                        
‘PUT’           ‘PUT’                                   HTTP Semantics RFC 9110(5), Section 9.3.4
                                                        
                                                        
‘DELETE’        ‘DELETE’                                HTTP Semantics RFC 9110(6), Section 9.3.5
                                                        
                                                        
‘CONNECT’       ‘CONNECT’                               HTTP Semantics RFC 9110(7), Section 9.3.6
                                                        
                                                        
‘OPTIONS’       ‘OPTIONS’                               HTTP Semantics RFC 9110(8), Section 9.3.7
                                                        
                                                        
‘TRACE’         ‘TRACE’                                 HTTP Semantics RFC 9110(9), Section 9.3.8
                                                        
                                                        
‘PATCH’         ‘PATCH’                                 HTTP/1.1 RFC 5789(10)
                                                        

   ---------- Footnotes ----------

   (1) https://www.iana.org/assignments/http-methods/http-methods.xhtml

   (2) https://datatracker.ietf.org/doc/html/rfc9110.html

   (3) https://datatracker.ietf.org/doc/html/rfc9110.html

   (4) https://datatracker.ietf.org/doc/html/rfc9110.html

   (5) https://datatracker.ietf.org/doc/html/rfc9110.html

   (6) https://datatracker.ietf.org/doc/html/rfc9110.html

   (7) https://datatracker.ietf.org/doc/html/rfc9110.html

   (8) https://datatracker.ietf.org/doc/html/rfc9110.html

   (9) https://datatracker.ietf.org/doc/html/rfc9110.html

   (10) https://datatracker.ietf.org/doc/html/rfc5789.html


File: python.info,  Node: http client — HTTP protocol client,  Next: ftplib — FTP protocol client,  Prev: http — HTTP modules,  Up: Internet Protocols and Support

5.22.10 ‘http.client’ — HTTP protocol client
--------------------------------------------

'Source code:' Lib/http/client.py(1)

__________________________________________________________________

This module defines classes that implement the client side of the HTTP
and HTTPS protocols.  It is normally not used directly — the module
*note urllib.request: 111. uses it to handle URLs that use HTTP and
HTTPS.

Vedi anche
..........

The Requests package(2) is recommended for a higher-level HTTP client
interface.

     Nota: HTTPS support is only available if Python was compiled with
     SSL support (through the *note ssl: d5. module).

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

The module provides the following classes:

 -- Classe: http.client.HTTPConnection (host, port=None[, timeout],
          source_address=None, blocksize=8192)

     An *note HTTPConnection: d37. instance represents one transaction
     with an HTTP server.  It should be instantiated by passing it a
     host and optional port number.  If no port number is passed, the
     port is extracted from the host string if it has the form
     ‘host:port’, else the default HTTP port (80) is used.  If the
     optional 'timeout' parameter is given, blocking operations (like
     connection attempts) will timeout after that many seconds (if it is
     not given, the global default timeout setting is used).  The
     optional 'source_address' parameter may be a tuple of a (host,
     port) to use as the source address the HTTP connection is made
     from.  The optional 'blocksize' parameter sets the buffer size in
     bytes for sending a file-like message body.

     For example, the following calls all create instances that connect
     to the server at the same host and port:

          >>> h1 = http.client.HTTPConnection('www.python.org')
          >>> h2 = http.client.HTTPConnection('www.python.org:80')
          >>> h3 = http.client.HTTPConnection('www.python.org', 80)
          >>> h4 = http.client.HTTPConnection('www.python.org', 80, timeout=10)

     Cambiato nella versione 3.2: 'source_address' was added.

     Cambiato nella versione 3.4: The 'strict' parameter was removed.
     HTTP 0.9-style «Simple Responses» are no longer supported.

     Cambiato nella versione 3.7: 'blocksize' parameter was added.

 -- Classe: http.client.HTTPSConnection (host, port=None, *[, timeout],
          source_address=None, context=None, blocksize=8192)

     A subclass of *note HTTPConnection: d37. that uses SSL for
     communication with secure servers.  Default port is ‘443’.  If
     'context' is specified, it must be a *note ssl.SSLContext: 357.
     instance describing the various SSL options.

     Please read *note Security considerations: 387b. for more
     information on best practices.

     Cambiato nella versione 3.2: 'source_address', 'context' and
     'check_hostname' were added.

     Cambiato nella versione 3.2: This class now supports HTTPS virtual
     hosts if possible (that is, if *note ssl.HAS_SNI: 39bc. is true).

     Cambiato nella versione 3.4: The 'strict' parameter was removed.
     HTTP 0.9-style «Simple Responses» are no longer supported.

     Cambiato nella versione 3.4.3: This class now performs all the
     necessary certificate and hostname checks by default.  To revert to
     the previous, unverified, behavior
     ‘ssl._create_unverified_context()’ can be passed to the 'context'
     parameter.

     Cambiato nella versione 3.8: This class now enables TLS 1.3 *note
     ssl.SSLContext.post_handshake_auth: c28. for the default 'context'
     or when 'cert_file' is passed with a custom 'context'.

     Cambiato nella versione 3.10: This class now sends an ALPN
     extension with protocol indicator ‘http/1.1’ when no 'context' is
     given.  Custom 'context' should set ALPN protocols with *note
     set_alpn_protocols(): 1066.

     Cambiato nella versione 3.12: The deprecated 'key_file',
     'cert_file' and 'check_hostname' parameters have been removed.

 -- Classe: http.client.HTTPResponse (sock, debuglevel=0, method=None,
          url=None)

     Class whose instances are returned upon successful connection.  Not
     instantiated directly by user.

     Cambiato nella versione 3.4: The 'strict' parameter was removed.
     HTTP 0.9 style «Simple Responses» are no longer supported.

This module provides the following function:

 -- Funzione: http.client.parse_headers (fp)

     Parse the headers from a file pointer 'fp' representing a HTTP
     request/response.  The file has to be a *note BufferedIOBase: 8a4.
     reader (i.e.  not text) and must provide a valid RFC 5322(3) style
     header.

     This function returns an instance of *note http.client.HTTPMessage:
     3faf. that holds the header fields, but no payload (the same as
     *note HTTPResponse.msg: 3fb0. and *note
     http.server.BaseHTTPRequestHandler.headers: 3fb1.).  After
     returning, the file pointer 'fp' is ready to read the HTTP body.

          Nota: *note parse_headers(): 1e10. does not parse the
          start-line of a HTTP message; it only parses the ‘Name: value’
          lines.  The file has to be ready to read these field lines, so
          the first line should already be consumed before calling the
          function.

The following exceptions are raised as appropriate:

 -- Eccezione: http.client.HTTPException

     The base class of the other exceptions in this module.  It is a
     subclass of *note Exception: bcf.

 -- Eccezione: http.client.NotConnected

     A subclass of *note HTTPException: 3fb2.

 -- Eccezione: http.client.InvalidURL

     A subclass of *note HTTPException: 3fb2, raised if a port is given
     and is either non-numeric or empty.

 -- Eccezione: http.client.UnknownProtocol

     A subclass of *note HTTPException: 3fb2.

 -- Eccezione: http.client.UnknownTransferEncoding

     A subclass of *note HTTPException: 3fb2.

 -- Eccezione: http.client.UnimplementedFileMode

     A subclass of *note HTTPException: 3fb2.

 -- Eccezione: http.client.IncompleteRead

     A subclass of *note HTTPException: 3fb2.

 -- Eccezione: http.client.ImproperConnectionState

     A subclass of *note HTTPException: 3fb2.

 -- Eccezione: http.client.CannotSendRequest

     A subclass of *note ImproperConnectionState: 3fb9.

 -- Eccezione: http.client.CannotSendHeader

     A subclass of *note ImproperConnectionState: 3fb9.

 -- Eccezione: http.client.ResponseNotReady

     A subclass of *note ImproperConnectionState: 3fb9.

 -- Eccezione: http.client.BadStatusLine

     A subclass of *note HTTPException: 3fb2.  Raised if a server
     responds with a HTTP status code that we don’t understand.

 -- Eccezione: http.client.LineTooLong

     A subclass of *note HTTPException: 3fb2.  Raised if an excessively
     long line is received in the HTTP protocol from the server.

 -- Eccezione: http.client.RemoteDisconnected

     A subclass of *note ConnectionResetError: 1261. and *note
     BadStatusLine: 3fbd.  Raised by *note HTTPConnection.getresponse():
     100b. when the attempt to read the response results in no data read
     from the connection, indicating that the remote end has closed the
     connection.

     Added in version 3.5: Previously, *note BadStatusLine: 3fbd.‘('')’
     was raised.

The constants defined in this module are:

 -- Dati: http.client.HTTP_PORT

     The default port for the HTTP protocol (always ‘80’).

 -- Dati: http.client.HTTPS_PORT

     The default port for the HTTPS protocol (always ‘443’).

 -- Dati: http.client.responses

     This dictionary maps the HTTP 1.1 status codes to the W3C names.

     Example: ‘http.client.responses[http.client.NOT_FOUND]’ is ‘'Not
     Found'’.

See *note HTTP status codes: 3fa6. for a list of HTTP status codes that
are available in this module as constants.

* Menu:

* HTTPConnection Objects::
* HTTPResponse Objects::
* Examples: Examples<28>.
* HTTPMessage Objects::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/http/client.py

   (2) https://requests.readthedocs.io/en/latest/

   (3) https://datatracker.ietf.org/doc/html/rfc5322.html


File: python.info,  Node: HTTPConnection Objects,  Next: HTTPResponse Objects,  Up: http client — HTTP protocol client

5.22.10.1 HTTPConnection Objects
................................

*note HTTPConnection: d37. instances have the following methods:

 -- Metodo: HTTPConnection.request (method, url, body=None, headers={},
          *, encode_chunked=False)

     This will send a request to the server using the HTTP request
     method 'method' and the request URI 'url'.  The provided 'url' must
     be an absolute path to conform with RFC 2616 §5.1.2(1) (unless
     connecting to an HTTP proxy server or using the ‘OPTIONS’ or
     ‘CONNECT’ methods).

     If 'body' is specified, the specified data is sent after the
     headers are finished.  It may be a *note str: 169, a *note
     bytes-like object: 193, an open *note file object: 13cb, or an
     iterable of *note bytes: 192.  If 'body' is a string, it is encoded
     as ISO-8859-1, the default for HTTP. If it is a bytes-like object,
     the bytes are sent as is.  If it is a *note file object: 13cb, the
     contents of the file is sent; this file object should support at
     least the ‘read()’ method.  If the file object is an instance of
     *note io.TextIOBase: 8a5, the data returned by the ‘read()’ method
     will be encoded as ISO-8859-1, otherwise the data returned by
     ‘read()’ is sent as is.  If 'body' is an iterable, the elements of
     the iterable are sent as is until the iterable is exhausted.

     The 'headers' argument should be a mapping of extra HTTP headers to
     send with the request.  A Host header(2) must be provided to
     conform with RFC 2616 §5.1.2(3) (unless connecting to an HTTP proxy
     server or using the ‘OPTIONS’ or ‘CONNECT’ methods).

     If 'headers' contains neither Content-Length nor Transfer-Encoding,
     but there is a request body, one of those header fields will be
     added automatically.  If 'body' is ‘None’, the Content-Length
     header is set to ‘0’ for methods that expect a body (‘PUT’, ‘POST’,
     and ‘PATCH’).  If 'body' is a string or a bytes-like object that is
     not also a *note file: 13cb, the Content-Length header is set to
     its length.  Any other type of 'body' (files and iterables in
     general) will be chunk-encoded, and the Transfer-Encoding header
     will automatically be set instead of Content-Length.

     The 'encode_chunked' argument is only relevant if Transfer-Encoding
     is specified in 'headers'.  If 'encode_chunked' is ‘False’, the
     HTTPConnection object assumes that all encoding is handled by the
     calling code.  If it is ‘True’, the body will be chunk-encoded.

     For example, to perform a ‘GET’ request to
     ‘https://docs.python.org/3/’:

          >>> import http.client
          >>> host = "docs.python.org"
          >>> conn = http.client.HTTPSConnection(host)
          >>> conn.request("GET", "/3/", headers={"Host": host})
          >>> response = conn.getresponse()
          >>> print(response.status, response.reason)
          200 OK

          Nota: Chunked transfer encoding has been added to the HTTP
          protocol version 1.1.  Unless the HTTP server is known to
          handle HTTP 1.1, the caller must either specify the
          Content-Length, or must pass a *note str: 169. or bytes-like
          object that is not also a file as the body representation.

          Nota: Note that you must have read the whole response or call
          *note close(): 3fc4. if *note getresponse(): 100b. raised an
          non-*note ConnectionError: 100d. exception before you can send
          a new request to the server.

     Cambiato nella versione 3.2: 'body' can now be an iterable.

     Cambiato nella versione 3.6: If neither Content-Length nor
     Transfer-Encoding are set in 'headers', file and iterable 'body'
     objects are now chunk-encoded.  The 'encode_chunked' argument was
     added.  No attempt is made to determine the Content-Length for file
     objects.

 -- Metodo: HTTPConnection.getresponse ()

     Should be called after a request is sent to get the response from
     the server.  Returns an *note HTTPResponse: 12d6. instance.

     Cambiato nella versione 3.5: If a *note ConnectionError: 100d. or
     subclass is raised, the *note HTTPConnection: d37. object will be
     ready to reconnect when a new request is sent.

     Note that this does not apply to *note OSError: 2c0.s raised by the
     underlying socket.  Instead the caller is responsible to call *note
     close(): 3fc4. on the existing connection.

 -- Metodo: HTTPConnection.set_debuglevel (level)

     Set the debugging level.  The default debug level is ‘0’, meaning
     no debugging output is printed.  Any value greater than ‘0’ will
     cause all currently defined debug output to be printed to stdout.
     The ‘debuglevel’ is passed to any new *note HTTPResponse: 12d6.
     objects that are created.

     Added in version 3.1.

 -- Metodo: HTTPConnection.set_tunnel (host, port=None, headers=None)

     Set the host and the port for HTTP Connect Tunnelling.  This allows
     running the connection through a proxy server.

     The 'host' and 'port' arguments specify the endpoint of the
     tunneled connection (i.e.  the address included in the CONNECT
     request, 'not' the address of the proxy server).

     The 'headers' argument should be a mapping of extra HTTP headers to
     send with the CONNECT request.

     As HTTP/1.1 is used for HTTP CONNECT tunnelling request, as per the
     RFC(4), a HTTP ‘Host:’ header must be provided, matching the
     authority-form of the request target provided as the destination
     for the CONNECT request.  If a HTTP ‘Host:’ header is not provided
     via the headers argument, one is generated and transmitted
     automatically.

     For example, to tunnel through a HTTPS proxy server running locally
     on port 8080, we would pass the address of the proxy to the *note
     HTTPSConnection: d38. constructor, and the address of the host that
     we eventually want to reach to the *note set_tunnel(): 1430.
     method:

          >>> import http.client
          >>> conn = http.client.HTTPSConnection("localhost", 8080)
          >>> conn.set_tunnel("www.python.org")
          >>> conn.request("HEAD","/index.html")

     Added in version 3.2.

     Cambiato nella versione 3.12: HTTP CONNECT tunnelling requests use
     protocol HTTP/1.1, upgraded from protocol HTTP/1.0.  ‘Host:’ HTTP
     headers are mandatory for HTTP/1.1, so one will be automatically
     generated and transmitted if not provided in the headers argument.

 -- Metodo: HTTPConnection.get_proxy_response_headers ()

     Returns a dictionary with the headers of the response received from
     the proxy server to the CONNECT request.

     If the CONNECT request was not sent, the method returns ‘None’.

     Added in version 3.12.

 -- Metodo: HTTPConnection.connect ()

     Connect to the server specified when the object was created.  By
     default, this is called automatically when making a request if the
     client does not already have a connection.

     Raises an *note auditing event: 1c56. ‘http.client.connect’ with
     arguments ‘self’, ‘host’, ‘port’.

 -- Metodo: HTTPConnection.close ()

     Close the connection to the server.

 -- Attributo: HTTPConnection.blocksize

     Buffer size in bytes for sending a file-like message body.

     Added in version 3.7.

As an alternative to using the *note request(): ea9. method described
above, you can also send your request step by step, by using the four
functions below.

 -- Metodo: HTTPConnection.putrequest (method, url, skip_host=False,
          skip_accept_encoding=False)

     This should be the first call after the connection to the server
     has been made.  It sends a line to the server consisting of the
     'method' string, the 'url' string, and the HTTP version
     (‘HTTP/1.1’).  To disable automatic sending of ‘Host:’ or
     ‘Accept-Encoding:’ headers (for example to accept additional
     content encodings), specify 'skip_host' or 'skip_accept_encoding'
     with non-False values.

 -- Metodo: HTTPConnection.putheader (header, argument[, ...])

     Send an RFC 822(5)-style header to the server.  It sends a line to
     the server consisting of the header, a colon and a space, and the
     first argument.  If more arguments are given, continuation lines
     are sent, each consisting of a tab and an argument.

 -- Metodo: HTTPConnection.endheaders (message_body=None, *,
          encode_chunked=False)

     Send a blank line to the server, signalling the end of the headers.
     The optional 'message_body' argument can be used to pass a message
     body associated with the request.

     If 'encode_chunked' is ‘True’, the result of each iteration of
     'message_body' will be chunk-encoded as specified in RFC 7230(6),
     Section 3.3.1.  How the data is encoded is dependent on the type of
     'message_body'.  If 'message_body' implements the *note buffer
     interface: 260. the encoding will result in a single chunk.  If
     'message_body' is a *note collections.abc.Iterable: 2691, each
     iteration of 'message_body' will result in a chunk.  If
     'message_body' is a *note file object: 13cb, each call to ‘.read()’
     will result in a chunk.  The method automatically signals the end
     of the chunk-encoded data immediately after 'message_body'.

          Nota: Due to the chunked encoding specification, empty chunks
          yielded by an iterator body will be ignored by the
          chunk-encoder.  This is to avoid premature termination of the
          read of the request by the target server due to malformed
          encoding.

     Cambiato nella versione 3.6: Added chunked encoding support and the
     'encode_chunked' parameter.

 -- Metodo: HTTPConnection.send (data)

     Send data to the server.  This should be used directly only after
     the *note endheaders(): eaa. method has been called and before
     *note getresponse(): 100b. is called.

     Raises an *note auditing event: 1c56. ‘http.client.send’ with
     arguments ‘self’, ‘data’.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2616.html#section-5.1.2

   (2) https://datatracker.ietf.org/doc/html/rfc2616.html#section-14.23

   (3) https://datatracker.ietf.org/doc/html/rfc2616.html#section-5.1.2

   (4) https://datatracker.ietf.org/doc/html/rfc7231#section-4.3.6

   (5) https://datatracker.ietf.org/doc/html/rfc822.html

   (6) https://datatracker.ietf.org/doc/html/rfc7230.html


File: python.info,  Node: HTTPResponse Objects,  Next: Examples<28>,  Prev: HTTPConnection Objects,  Up: http client — HTTP protocol client

5.22.10.2 HTTPResponse Objects
..............................

An *note HTTPResponse: 12d6. instance wraps the HTTP response from the
server.  It provides access to the request headers and the entity body.
The response is an iterable object and can be used in a with statement.

Cambiato nella versione 3.5: The *note io.BufferedIOBase: 8a4. interface
is now implemented and all of its reader operations are supported.

 -- Metodo: HTTPResponse.read ([amt])

     Reads and returns the response body, or up to the next 'amt' bytes.

 -- Metodo: HTTPResponse.readinto (b)

     Reads up to the next len(b) bytes of the response body into the
     buffer 'b'.  Returns the number of bytes read.

     Added in version 3.3.

 -- Metodo: HTTPResponse.getheader (name, default=None)

     Return the value of the header 'name', or 'default' if there is no
     header matching 'name'.  If there is more than one header with the
     name 'name', return all of the values joined by “, “.  If 'default'
     is any iterable other than a single string, its elements are
     similarly returned joined by commas.

 -- Metodo: HTTPResponse.getheaders ()

     Return a list of (header, value) tuples.

 -- Metodo: HTTPResponse.fileno ()

     Return the ‘fileno’ of the underlying socket.

 -- Attributo: HTTPResponse.msg

     A *note http.client.HTTPMessage: 3faf. instance containing the
     response headers.  *note http.client.HTTPMessage: 3faf. is a
     subclass of *note email.message.Message: 581.

 -- Attributo: HTTPResponse.version

     HTTP protocol version used by server.  10 for HTTP/1.0, 11 for
     HTTP/1.1.

 -- Attributo: HTTPResponse.url

     URL of the resource retrieved, commonly used to determine if a
     redirect was followed.

 -- Attributo: HTTPResponse.headers

     Headers of the response in the form of an *note
     email.message.EmailMessage: 580. instance.

 -- Attributo: HTTPResponse.status

     Status code returned by server.

 -- Attributo: HTTPResponse.reason

     Reason phrase returned by server.

 -- Attributo: HTTPResponse.debuglevel

     A debugging hook.  If *note debuglevel: 3fd4. is greater than zero,
     messages will be printed to stdout as the response is read and
     parsed.

 -- Attributo: HTTPResponse.closed

     Is ‘True’ if the stream is closed.

 -- Metodo: HTTPResponse.geturl ()

     Deprecato dalla versione 3.9: Deprecated in favor of *note url:
     3fd1.

 -- Metodo: HTTPResponse.info ()

     Deprecato dalla versione 3.9: Deprecated in favor of *note headers:
     3fd2.

 -- Metodo: HTTPResponse.getcode ()

     Deprecato dalla versione 3.9: Deprecated in favor of *note status:
     3fd3.


File: python.info,  Node: Examples<28>,  Next: HTTPMessage Objects,  Prev: HTTPResponse Objects,  Up: http client — HTTP protocol client

5.22.10.3 Examples
..................

Here is an example session that uses the ‘GET’ method:

     >>> import http.client
     >>> conn = http.client.HTTPSConnection("www.python.org")
     >>> conn.request("GET", "/")
     >>> r1 = conn.getresponse()
     >>> print(r1.status, r1.reason)
     200 OK
     >>> data1 = r1.read()  # This will return entire content.
     >>> # The following example demonstrates reading data in chunks.
     >>> conn.request("GET", "/")
     >>> r1 = conn.getresponse()
     >>> while chunk := r1.read(200):
     ...     print(repr(chunk))
     b'<!doctype html>\n<!--[if"...
     ...
     >>> # Example of an invalid request
     >>> conn = http.client.HTTPSConnection("docs.python.org")
     >>> conn.request("GET", "/parrot.spam")
     >>> r2 = conn.getresponse()
     >>> print(r2.status, r2.reason)
     404 Not Found
     >>> data2 = r2.read()
     >>> conn.close()

Here is an example session that uses the ‘HEAD’ method.  Note that the
‘HEAD’ method never returns any data.

     >>> import http.client
     >>> conn = http.client.HTTPSConnection("www.python.org")
     >>> conn.request("HEAD", "/")
     >>> res = conn.getresponse()
     >>> print(res.status, res.reason)
     200 OK
     >>> data = res.read()
     >>> print(len(data))
     0
     >>> data == b''
     True

Here is an example session that uses the ‘POST’ method:

     >>> import http.client, urllib.parse
     >>> params = urllib.parse.urlencode({'@number': 12524, '@type': 'issue', '@action': 'show'})
     >>> headers = {"Content-type": "application/x-www-form-urlencoded",
     ...            "Accept": "text/plain"}
     >>> conn = http.client.HTTPConnection("bugs.python.org")
     >>> conn.request("POST", "", params, headers)
     >>> response = conn.getresponse()
     >>> print(response.status, response.reason)
     302 Found
     >>> data = response.read()
     >>> data
     b'Redirecting to <a href="https://bugs.python.org/issue12524">https://bugs.python.org/issue12524</a>'
     >>> conn.close()

Client side HTTP ‘PUT’ requests are very similar to ‘POST’ requests.
The difference lies only on the server side where HTTP servers will
allow resources to be created via ‘PUT’ requests.  It should be noted
that custom HTTP methods are also handled in *note
urllib.request.Request: 11da. by setting the appropriate method
attribute.  Here is an example session that uses the ‘PUT’ method:

     >>> # This creates an HTTP request
     >>> # with the content of BODY as the enclosed representation
     >>> # for the resource http://localhost:8080/file
     ...
     >>> import http.client
     >>> BODY = "***filecontents***"
     >>> conn = http.client.HTTPConnection("localhost", 8080)
     >>> conn.request("PUT", "/file", BODY)
     >>> response = conn.getresponse()
     >>> print(response.status, response.reason)
     200, OK


File: python.info,  Node: HTTPMessage Objects,  Prev: Examples<28>,  Up: http client — HTTP protocol client

5.22.10.4 HTTPMessage Objects
.............................

 -- Classe: http.client.HTTPMessage (email.message.Message)

An *note http.client.HTTPMessage: 3faf. instance holds the headers from
an HTTP response.  It is implemented using the *note
email.message.Message: 581. class.


File: python.info,  Node: ftplib — FTP protocol client,  Next: poplib — POP3 protocol client,  Prev: http client — HTTP protocol client,  Up: Internet Protocols and Support

5.22.11 ‘ftplib’ — FTP protocol client
--------------------------------------

'Source code:' Lib/ftplib.py(1)

__________________________________________________________________

This module defines the class *note FTP: af8. and a few related items.
The *note FTP: af8. class implements the client side of the FTP
protocol.  You can use this to write Python programs that perform a
variety of automated FTP jobs, such as mirroring other FTP servers.  It
is also used by the module *note urllib.request: 111. to handle URLs
that use FTP. For more information on FTP (File Transfer Protocol), see
internet RFC 959(2).

The default encoding is UTF-8, following RFC 2640(3).

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

Here’s a sample session using the *note ftplib: 62. module:

     >>> from ftplib import FTP
     >>> ftp = FTP('ftp.us.debian.org')  # connect to host, default port
     >>> ftp.login()                     # user anonymous, passwd anonymous@
     '230 Login successful.'
     >>> ftp.cwd('debian')               # change into "debian" directory
     '250 Directory successfully changed.'
     >>> ftp.retrlines('LIST')           # list directory contents
     -rw-rw-r--    1 1176     1176         1063 Jun 15 10:18 README
     ...
     drwxr-sr-x    5 1176     1176         4096 Dec 19  2000 pool
     drwxr-sr-x    4 1176     1176         4096 Nov 17  2008 project
     drwxr-xr-x    3 1176     1176         4096 Oct 10  2012 tools
     '226 Directory send OK.'
     >>> with open('README', 'wb') as fp:
     >>>     ftp.retrbinary('RETR README', fp.write)
     '226 Transfer complete.'
     >>> ftp.quit()
     '221 Goodbye.'

* Menu:

* Reference: Reference<7>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/ftplib.py

   (2) https://datatracker.ietf.org/doc/html/rfc959.html

   (3) https://datatracker.ietf.org/doc/html/rfc2640.html


File: python.info,  Node: Reference<7>,  Up: ftplib — FTP protocol client

5.22.11.1 Reference
...................

* Menu:

* FTP objects::
* FTP_TLS objects::
* Module variables::


File: python.info,  Node: FTP objects,  Next: FTP_TLS objects,  Up: Reference<7>

5.22.11.2 FTP objects
.....................

 -- Classe: ftplib.FTP (host='', user='', passwd='', acct='',
          timeout=None, source_address=None, *, encoding='utf-8')

     Return a new instance of the *note FTP: af8. class.


     Parametri:

        * ‘host’ (*note str: 169.) – The hostname to connect to.  If
          given, ‘connect(host)’ is implicitly called by the
          constructor.

        * ‘user’ (*note str: 169.) – The username to log in with
          (default: ‘'anonymous'’).  If given, ‘login(host, passwd,
          acct)’ is implicitly called by the constructor.

        * ‘passwd’ (*note str: 169.) – The password to use when logging
          in.  If not given, and if 'passwd' is the empty string or
          ‘"-"’, a password will be automatically generated.

        * ‘acct’ (*note str: 169.) – Account information to be used for
          the ‘ACCT’ FTP command.  Few systems implement this.  See
          RFC-959(1) for more details.

        * ‘timeout’ (*note float: 196.‘ | ’‘None’) – A timeout in
          seconds for blocking operations like *note connect(): 3fe3.
          (default: the global default timeout setting).

        * ‘source_address’ (*note tuple: 614.‘ | ’‘None’) – A 2-tuple
          ‘(host, port)’ for the socket to bind to as its source address
          before connecting.

        * ‘encoding’ (*note str: 169.) – The encoding for directories
          and filenames (default: ‘'utf-8'’).

     The *note FTP: af8. class supports the *note with: 186. statement,
     e.g.:

          >>> from ftplib import FTP
          >>> with FTP("ftp1.at.proftpd.org") as ftp:
          ...     ftp.login()
          ...     ftp.dir()
          ...
          '230 Anonymous login ok, restrictions apply.'
          dr-xr-xr-x   9 ftp      ftp           154 May  6 10:43 .
          dr-xr-xr-x   9 ftp      ftp           154 May  6 10:43 ..
          dr-xr-xr-x   5 ftp      ftp          4096 May  6 10:43 CentOS
          dr-xr-xr-x   3 ftp      ftp            18 Jul 10  2008 Fedora
          >>>

     Cambiato nella versione 3.2: Support for the *note with: 186.
     statement was added.

     Cambiato nella versione 3.3: 'source_address' parameter was added.

     Cambiato nella versione 3.9: If the 'timeout' parameter is set to
     be zero, it will raise a *note ValueError: 2ec. to prevent the
     creation of a non-blocking socket.  The 'encoding' parameter was
     added, and the default was changed from Latin-1 to UTF-8 to follow
     RFC 2640(2).

     Several ‘FTP’ methods are available in two flavors: one for
     handling text files and another for binary files.  The methods are
     named for the command which is used followed by ‘lines’ for the
     text version or ‘binary’ for the binary version.

     *note FTP: af8. instances have the following methods:

      -- Metodo: set_debuglevel (level)

          Set the instance’s debugging level as an *note int: 19b.  This
          controls the amount of debugging output printed.  The debug
          levels are:

             * ‘0’ (default): No debug output.

             * ‘1’: Produce a moderate amount of debug output, generally
               a single line per request.

             * ‘2’ or higher: Produce the maximum amount of debugging
               output, logging each line sent and received on the
               control connection.

      -- Metodo: connect (host='', port=0, timeout=None,
               source_address=None)

          Connect to the given host and port.  This function should be
          called only once for each instance; it should not be called if
          a 'host' argument was given when the *note FTP: af8. instance
          was created.  All other ‘FTP’ methods can only be called after
          a connection has successfully been made.


          Parametri:

             * ‘host’ (*note str: 169.) – The host to connect to.

             * ‘port’ (*note int: 19b.) – The TCP port to connect to
               (default: ‘21’, as specified by the FTP protocol
               specification).  It is rarely needed to specify a
               different port number.

             * ‘timeout’ (*note float: 196.‘ | ’‘None’) – A timeout in
               seconds for the connection attempt (default: the global
               default timeout setting).

             * ‘source_address’ (*note tuple: 614.‘ | ’‘None’) – A
               2-tuple ‘(host, port)’ for the socket to bind to as its
               source address before connecting.

          Raises an *note auditing event: 1c56. ‘ftplib.connect’ with
          arguments ‘self’, ‘host’, ‘port’.

          Cambiato nella versione 3.3: 'source_address' parameter was
          added.

      -- Metodo: getwelcome ()

          Return the welcome message sent by the server in reply to the
          initial connection.  (This message sometimes contains
          disclaimers or help information that may be relevant to the
          user.)

      -- Metodo: login (user='anonymous', passwd='', acct='')

          Log on to the connected FTP server.  This function should be
          called only once for each instance, after a connection has
          been established; it should not be called if the 'host' and
          'user' arguments were given when the *note FTP: af8. instance
          was created.  Most FTP commands are only allowed after the
          client has logged in.


          Parametri:

             * ‘user’ (*note str: 169.) – The username to log in with
               (default: ‘'anonymous'’).

             * ‘passwd’ (*note str: 169.) – The password to use when
               logging in.  If not given, and if 'passwd' is the empty
               string or ‘"-"’, a password will be automatically
               generated.

             * ‘acct’ (*note str: 169.) – Account information to be used
               for the ‘ACCT’ FTP command.  Few systems implement this.
               See RFC-959(3) for more details.

      -- Metodo: abort ()

          Abort a file transfer that is in progress.  Using this does
          not always work, but it’s worth a try.

      -- Metodo: sendcmd (cmd)

          Send a simple command string to the server and return the
          response string.

          Raises an *note auditing event: 1c56. ‘ftplib.sendcmd’ with
          arguments ‘self’, ‘cmd’.

      -- Metodo: voidcmd (cmd)

          Send a simple command string to the server and handle the
          response.  Return the response string if the response code
          corresponds to success (codes in the range 200–299).  Raise
          *note error_reply: 3fea. otherwise.

          Raises an *note auditing event: 1c56. ‘ftplib.sendcmd’ with
          arguments ‘self’, ‘cmd’.

      -- Metodo: retrbinary (cmd, callback, blocksize=8192, rest=None)

          Retrieve a file in binary transfer mode.


          Parametri:

             * ‘cmd’ (*note str: 169.) – An appropriate ‘RETR’ command:
               ‘"RETR FILENAME"’.

             * ‘callback’ (*note callable: 2d61.) – A single parameter
               callable that is called for each block of data received,
               with its single argument being the data as *note bytes:
               192.

             * ‘blocksize’ (*note int: 19b.) – The maximum chunk size to
               read on the low-level *note socket: fa3. object created
               to do the actual transfer.  This also corresponds to the
               largest size of data that will be passed to 'callback'.
               Defaults to ‘8192’.

             * ‘rest’ (*note int: 19b.) – A ‘REST’ command to be sent to
               the server.  See the documentation for the 'rest'
               parameter of the *note transfercmd(): 3fec. method.

      -- Metodo: retrlines (cmd, callback=None)

          Retrieve a file or directory listing in the encoding specified
          by the 'encoding' parameter at initialization.  'cmd' should
          be an appropriate ‘RETR’ command (see *note retrbinary():
          3feb.) or a command such as ‘LIST’ or ‘NLST’ (usually just the
          string ‘'LIST'’).  ‘LIST’ retrieves a list of files and
          information about those files.  ‘NLST’ retrieves a list of
          file names.  The 'callback' function is called for each line
          with a string argument containing the line with the trailing
          CRLF stripped.  The default 'callback' prints the line to
          *note sys.stdout: ccf.

      -- Metodo: set_pasv (val)

          Enable «passive» mode if 'val' is true, otherwise disable
          passive mode.  Passive mode is on by default.

      -- Metodo: storbinary (cmd, fp, blocksize=8192, callback=None,
               rest=None)

          Store a file in binary transfer mode.


          Parametri:

             * ‘cmd’ (*note str: 169.) – An appropriate ‘STOR’ command:
               ‘"STOR FILENAME"’.

             * ‘fp’ (*note file object: 13cb.) – A file object (opened
               in binary mode) which is read until EOF, using its *note
               read(): 101f. method in blocks of size 'blocksize' to
               provide the data to be stored.

             * ‘blocksize’ (*note int: 19b.) – The read block size.
               Defaults to ‘8192’.

             * ‘callback’ (*note callable: 2d61.) – A single parameter
               callable that is called for each block of data sent, with
               its single argument being the data as *note bytes: 192.

             * ‘rest’ (*note int: 19b.) – A ‘REST’ command to be sent to
               the server.  See the documentation for the 'rest'
               parameter of the *note transfercmd(): 3fec. method.

          Cambiato nella versione 3.2: The 'rest' parameter was added.

      -- Metodo: storlines (cmd, fp, callback=None)

          Store a file in line mode.  'cmd' should be an appropriate
          ‘STOR’ command (see *note storbinary(): 1511.).  Lines are
          read until EOF from the *note file object: 13cb. 'fp' (opened
          in binary mode) using its *note readline(): 1531. method to
          provide the data to be stored.  'callback' is an optional
          single parameter callable that is called on each line after it
          is sent.

      -- Metodo: transfercmd (cmd, rest=None)

          Initiate a transfer over the data connection.  If the transfer
          is active, send an ‘EPRT’ or ‘PORT’ command and the transfer
          command specified by 'cmd', and accept the connection.  If the
          server is passive, send an ‘EPSV’ or ‘PASV’ command, connect
          to it, and start the transfer command.  Either way, return the
          socket for the connection.

          If optional 'rest' is given, a ‘REST’ command is sent to the
          server, passing 'rest' as an argument.  'rest' is usually a
          byte offset into the requested file, telling the server to
          restart sending the file’s bytes at the requested offset,
          skipping over the initial bytes.  Note however that the *note
          transfercmd(): 3fec. method converts 'rest' to a string with
          the 'encoding' parameter specified at initialization, but no
          check is performed on the string’s contents.  If the server
          does not recognize the ‘REST’ command, an *note error_reply:
          3fea. exception will be raised.  If this happens, simply call
          *note transfercmd(): 3fec. without a 'rest' argument.

      -- Metodo: ntransfercmd (cmd, rest=None)

          Like *note transfercmd(): 3fec, but returns a tuple of the
          data connection and the expected size of the data.  If the
          expected size could not be computed, ‘None’ will be returned
          as the expected size.  'cmd' and 'rest' means the same thing
          as in *note transfercmd(): 3fec.

      -- Metodo: mlsd (path='', facts=[])

          List a directory in a standardized format by using ‘MLSD’
          command ( RFC 3659(4)).  If 'path' is omitted the current
          directory is assumed.  'facts' is a list of strings
          representing the type of information desired (e.g.  ‘["type",
          "size", "perm"]’).  Return a generator object yielding a tuple
          of two elements for every file found in path.  First element
          is the file name, the second one is a dictionary containing
          facts about the file name.  Content of this dictionary might
          be limited by the 'facts' argument but server is not
          guaranteed to return all requested facts.

          Added in version 3.3.

      -- Metodo: nlst (argument[, ...])

          Return a list of file names as returned by the ‘NLST’ command.
          The optional 'argument' is a directory to list (default is the
          current server directory).  Multiple arguments can be used to
          pass non-standard options to the ‘NLST’ command.

               Nota: If your server supports the command, *note mlsd():
               12ca. offers a better API.

      -- Metodo: dir (argument[, ...])

          Produce a directory listing as returned by the ‘LIST’ command,
          printing it to standard output.  The optional 'argument' is a
          directory to list (default is the current server directory).
          Multiple arguments can be used to pass non-standard options to
          the ‘LIST’ command.  If the last argument is a function, it is
          used as a 'callback' function as for *note retrlines(): 3fed.;
          the default prints to *note sys.stdout: ccf.  This method
          returns ‘None’.

               Nota: If your server supports the command, *note mlsd():
               12ca. offers a better API.

      -- Metodo: rename (fromname, toname)

          Rename file 'fromname' on the server to 'toname'.

      -- Metodo: delete (filename)

          Remove the file named 'filename' from the server.  If
          successful, returns the text of the response, otherwise raises
          *note error_perm: 3ff3. on permission errors or *note
          error_reply: 3fea. on other errors.

      -- Metodo: cwd (pathname)

          Set the current directory on the server.

      -- Metodo: mkd (pathname)

          Create a new directory on the server.

      -- Metodo: pwd ()

          Return the pathname of the current directory on the server.

      -- Metodo: rmd (dirname)

          Remove the directory named 'dirname' on the server.

      -- Metodo: size (filename)

          Request the size of the file named 'filename' on the server.
          On success, the size of the file is returned as an integer,
          otherwise ‘None’ is returned.  Note that the ‘SIZE’ command is
          not standardized, but is supported by many common server
          implementations.

      -- Metodo: quit ()

          Send a ‘QUIT’ command to the server and close the connection.
          This is the «polite» way to close a connection, but it may
          raise an exception if the server responds with an error to the
          ‘QUIT’ command.  This implies a call to the *note close():
          3ffa. method which renders the *note FTP: af8. instance
          useless for subsequent calls (see below).

      -- Metodo: close ()

          Close the connection unilaterally.  This should not be applied
          to an already closed connection such as after a successful
          call to *note quit(): 3ff9.  After this call the *note FTP:
          af8. instance should not be used any more (after a call to
          *note close(): 3ffa. or *note quit(): 3ff9. you cannot reopen
          the connection by issuing another *note login(): 3fe6.
          method).

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc959.html

   (2) https://datatracker.ietf.org/doc/html/rfc2640.html

   (3) https://datatracker.ietf.org/doc/html/rfc959.html

   (4) https://datatracker.ietf.org/doc/html/rfc3659.html


File: python.info,  Node: FTP_TLS objects,  Next: Module variables,  Prev: FTP objects,  Up: Reference<7>

5.22.11.3 FTP_TLS objects
.........................

 -- Classe: ftplib.FTP_TLS (host='', user='', passwd='', acct='', *,
          context=None, timeout=None, source_address=None,
          encoding='utf-8')

     An *note FTP: af8. subclass which adds TLS support to FTP as
     described in RFC 4217(1).  Connect to port 21 implicitly securing
     the FTP control connection before authenticating.

          Nota: The user must explicitly secure the data connection by
          calling the *note prot_p(): 3ffc. method.


     Parametri:

        * ‘host’ (*note str: 169.) – The hostname to connect to.  If
          given, ‘connect(host)’ is implicitly called by the
          constructor.

        * ‘user’ (*note str: 169.) – The username to log in with
          (default: ‘'anonymous'’).  If given, ‘login(host, passwd,
          acct)’ is implicitly called by the constructor.

        * ‘passwd’ (*note str: 169.) – The password to use when logging
          in.  If not given, and if 'passwd' is the empty string or
          ‘"-"’, a password will be automatically generated.

        * ‘acct’ (*note str: 169.) – Account information to be used for
          the ‘ACCT’ FTP command.  Few systems implement this.  See
          RFC-959(2) for more details.

        * ‘context’ (*note ssl.SSLContext: 357.) – An SSL context object
          which allows bundling SSL configuration options, certificates
          and private keys into a single, potentially long-lived,
          structure.  Please read *note Security considerations: 387b.
          for best practices.

        * ‘timeout’ (*note float: 196.‘ | ’‘None’) – A timeout in
          seconds for blocking operations like *note connect(): 3fe3.
          (default: the global default timeout setting).

        * ‘source_address’ (*note tuple: 614.‘ | ’‘None’) – A 2-tuple
          ‘(host, port)’ for the socket to bind to as its source address
          before connecting.

        * ‘encoding’ (*note str: 169.) – The encoding for directories
          and filenames (default: ‘'utf-8'’).

     Added in version 3.2.

     Cambiato nella versione 3.3: Added the 'source_address' parameter.

     Cambiato nella versione 3.4: The class now supports hostname check
     with *note ssl.SSLContext.check_hostname: 39aa. and 'Server Name
     Indication' (see *note ssl.HAS_SNI: 39bc.).

     Cambiato nella versione 3.9: If the 'timeout' parameter is set to
     be zero, it will raise a *note ValueError: 2ec. to prevent the
     creation of a non-blocking socket.  The 'encoding' parameter was
     added, and the default was changed from Latin-1 to UTF-8 to follow
     RFC 2640(3).

     Cambiato nella versione 3.12: The deprecated 'keyfile' and
     'certfile' parameters have been removed.

     Here’s a sample session using the *note FTP_TLS: af9. class:

          >>> ftps = FTP_TLS('ftp.pureftpd.org')
          >>> ftps.login()
          '230 Anonymous user logged in'
          >>> ftps.prot_p()
          '200 Data protection level set to "private"'
          >>> ftps.nlst()
          ['6jack', 'OpenBSD', 'antilink', 'blogbench', 'bsdcam', 'clockspeed', 'djbdns-jedi', 'docs', 'eaccelerator-jedi', 'favicon.ico', 'francotone', 'fugu', 'ignore', 'libpuzzle', 'metalog', 'minidentd', 'misc', 'mysql-udf-global-user-variables', 'php-jenkins-hash', 'php-skein-hash', 'php-webdav', 'phpaudit', 'phpbench', 'pincaster', 'ping', 'posto', 'pub', 'public', 'public_keys', 'pure-ftpd', 'qscan', 'qtc', 'sharedance', 'skycache', 'sound', 'tmp', 'ucarp']

     ‘FTP_TLS’ class inherits from *note FTP: af8, defining these
     additional methods and attributes:

      -- Attributo: ssl_version

          The SSL version to use (defaults to *note ssl.PROTOCOL_SSLv23:
          39ae.).

      -- Metodo: auth ()

          Set up a secure control connection by using TLS or SSL,
          depending on what is specified in the *note ssl_version: 3ffd.
          attribute.

          Cambiato nella versione 3.4: The method now supports hostname
          check with *note ssl.SSLContext.check_hostname: 39aa. and
          'Server Name Indication' (see *note ssl.HAS_SNI: 39bc.).

      -- Metodo: ccc ()

          Revert control channel back to plaintext.  This can be useful
          to take advantage of firewalls that know how to handle NAT
          with non-secure FTP without opening fixed ports.

          Added in version 3.3.

      -- Metodo: prot_p ()

          Set up secure data connection.

      -- Metodo: prot_c ()

          Set up clear text data connection.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc4217.html

   (2) https://datatracker.ietf.org/doc/html/rfc959.html

   (3) https://datatracker.ietf.org/doc/html/rfc2640.html


File: python.info,  Node: Module variables,  Prev: FTP_TLS objects,  Up: Reference<7>

5.22.11.4 Module variables
..........................

 -- Eccezione: ftplib.error_reply

     Exception raised when an unexpected reply is received from the
     server.

 -- Eccezione: ftplib.error_temp

     Exception raised when an error code signifying a temporary error
     (response codes in the range 400–499) is received.

 -- Eccezione: ftplib.error_perm

     Exception raised when an error code signifying a permanent error
     (response codes in the range 500–599) is received.

 -- Eccezione: ftplib.error_proto

     Exception raised when a reply is received from the server that does
     not fit the response specifications of the File Transfer Protocol,
     i.e.  begin with a digit in the range 1–5.

 -- Dati: ftplib.all_errors

     The set of all exceptions (as a tuple) that methods of *note FTP:
     af8. instances may raise as a result of problems with the FTP
     connection (as opposed to programming errors made by the caller).
     This set includes the four exceptions listed above as well as *note
     OSError: 2c0. and *note EOFError: 14e1.

Vedi anche
..........

Module *note netrc: 9f.

     Parser for the ‘.netrc’ file format.  The file ‘.netrc’ is
     typically used by FTP clients to load user authentication
     information before prompting the user.


File: python.info,  Node: poplib — POP3 protocol client,  Next: imaplib — IMAP4 protocol client,  Prev: ftplib — FTP protocol client,  Up: Internet Protocols and Support

5.22.12 ‘poplib’ — POP3 protocol client
---------------------------------------

'Source code:' Lib/poplib.py(1)

__________________________________________________________________

This module defines a class, *note POP3: b1f, which encapsulates a
connection to a POP3 server and implements the protocol as defined in
RFC 1939(2).  The *note POP3: b1f. class supports both the minimal and
optional command sets from RFC 1939(3).  The *note POP3: b1f. class also
supports the ‘STLS’ command introduced in RFC 2595(4) to enable
encrypted communication on an already established connection.

Additionally, this module provides a class *note POP3_SSL: b20, which
provides support for connecting to POP3 servers that use SSL as an
underlying protocol layer.

Note that POP3, though widely supported, is obsolescent.  The
implementation quality of POP3 servers varies widely, and too many are
quite poor.  If your mailserver supports IMAP, you would be better off
using the *note imaplib.IMAP4: b01. class, as IMAP servers tend to be
better implemented.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

The *note poplib: b1. module provides two classes:

 -- Classe: poplib.POP3 (host, port=POP3_PORT[, timeout])

     This class implements the actual POP3 protocol.  The connection is
     created when the instance is initialized.  If 'port' is omitted,
     the standard POP3 port (110) is used.  The optional 'timeout'
     parameter specifies a timeout in seconds for the connection attempt
     (if not specified, the global default timeout setting will be
     used).

     Raises an *note auditing event: 1c56. ‘poplib.connect’ with
     arguments ‘self’, ‘host’, ‘port’.

     All commands will raise an *note auditing event: 1c56.
     ‘poplib.putline’ with arguments ‘self’ and ‘line’, where ‘line’ is
     the bytes about to be sent to the remote host.

     Cambiato nella versione 3.9: If the 'timeout' parameter is set to
     be zero, it will raise a *note ValueError: 2ec. to prevent the
     creation of a non-blocking socket.

 -- Classe: poplib.POP3_SSL (host, port=POP3_SSL_PORT, *, timeout=None,
          context=None)

     This is a subclass of *note POP3: b1f. that connects to the server
     over an SSL encrypted socket.  If 'port' is not specified, 995, the
     standard POP3-over-SSL port is used.  'timeout' works as in the
     *note POP3: b1f. constructor.  'context' is an optional *note
     ssl.SSLContext: 357. object which allows bundling SSL configuration
     options, certificates and private keys into a single (potentially
     long-lived) structure.  Please read *note Security considerations:
     387b. for best practices.

     Raises an *note auditing event: 1c56. ‘poplib.connect’ with
     arguments ‘self’, ‘host’, ‘port’.

     All commands will raise an *note auditing event: 1c56.
     ‘poplib.putline’ with arguments ‘self’ and ‘line’, where ‘line’ is
     the bytes about to be sent to the remote host.

     Cambiato nella versione 3.2: 'context' parameter added.

     Cambiato nella versione 3.4: The class now supports hostname check
     with *note ssl.SSLContext.check_hostname: 39aa. and 'Server Name
     Indication' (see *note ssl.HAS_SNI: 39bc.).

     Cambiato nella versione 3.9: If the 'timeout' parameter is set to
     be zero, it will raise a *note ValueError: 2ec. to prevent the
     creation of a non-blocking socket.

     Cambiato nella versione 3.12: The deprecated 'keyfile' and
     'certfile' parameters have been removed.

One exception is defined as an attribute of the *note poplib: b1.
module:

 -- Eccezione: poplib.error_proto

     Exception raised on any errors from this module (errors from *note
     socket: d1. module are not caught).  The reason for the exception
     is passed to the constructor as a string.

Vedi anche
..........

Module *note imaplib: 78.

     The standard Python IMAP module.

Frequently Asked Questions About Fetchmail(5)

     The FAQ for the ‘fetchmail’ POP/IMAP client collects information on
     POP3 server variations and RFC noncompliance that may be useful if
     you need to write an application based on the POP protocol.

* Menu:

* POP3 Objects::
* POP3 Example::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/poplib.py

   (2) https://datatracker.ietf.org/doc/html/rfc1939.html

   (3) https://datatracker.ietf.org/doc/html/rfc1939.html

   (4) https://datatracker.ietf.org/doc/html/rfc2595.html

   (5) http://www.catb.org/~esr/fetchmail/fetchmail-FAQ.html


File: python.info,  Node: POP3 Objects,  Next: POP3 Example,  Up: poplib — POP3 protocol client

5.22.12.1 POP3 Objects
......................

All POP3 commands are represented by methods of the same name, in
lowercase; most return the response text sent by the server.

A *note POP3: b1f. instance has the following methods:

 -- Metodo: POP3.set_debuglevel (level)

     Set the instance’s debugging level.  This controls the amount of
     debugging output printed.  The default, ‘0’, produces no debugging
     output.  A value of ‘1’ produces a moderate amount of debugging
     output, generally a single line per request.  A value of ‘2’ or
     higher produces the maximum amount of debugging output, logging
     each line sent and received on the control connection.

 -- Metodo: POP3.getwelcome ()

     Returns the greeting string sent by the POP3 server.

 -- Metodo: POP3.capa ()

     Query the server’s capabilities as specified in RFC 2449(1).
     Returns a dictionary in the form ‘{'name': ['param'...]}’.

     Added in version 3.4.

 -- Metodo: POP3.user (username)

     Send user command, response should indicate that a password is
     required.

 -- Metodo: POP3.pass_ (password)

     Send password, response includes message count and mailbox size.
     Note: the mailbox on the server is locked until *note quit(): 13a3.
     is called.

 -- Metodo: POP3.apop (user, secret)

     Use the more secure APOP authentication to log into the POP3
     server.

 -- Metodo: POP3.rpop (user)

     Use RPOP authentication (similar to UNIX r-commands) to log into
     POP3 server.

 -- Metodo: POP3.stat ()

     Get mailbox status.  The result is a tuple of 2 integers: ‘(message
     count, mailbox size)’.

 -- Metodo: POP3.list ([which])

     Request message list, result is in the form ‘(response, ['mesg_num
     octets', ...], octets)’.  If 'which' is set, it is the message to
     list.

 -- Metodo: POP3.retr (which)

     Retrieve whole message number 'which', and set its seen flag.
     Result is in form ‘(response, ['line', ...], octets)’.

 -- Metodo: POP3.dele (which)

     Flag message number 'which' for deletion.  On most servers
     deletions are not actually performed until QUIT (the major
     exception is Eudora QPOP, which deliberately violates the RFCs by
     doing pending deletes on any disconnect).

 -- Metodo: POP3.rset ()

     Remove any deletion marks for the mailbox.

 -- Metodo: POP3.noop ()

     Do nothing.  Might be used as a keep-alive.

 -- Metodo: POP3.quit ()

     Signoff: commit changes, unlock mailbox, drop connection.

 -- Metodo: POP3.top (which, howmuch)

     Retrieves the message header plus 'howmuch' lines of the message
     after the header of message number 'which'.  Result is in form
     ‘(response, ['line', ...], octets)’.

     The POP3 TOP command this method uses, unlike the RETR command,
     doesn’t set the message’s seen flag; unfortunately, TOP is poorly
     specified in the RFCs and is frequently broken in off-brand
     servers.  Test this method by hand against the POP3 servers you
     will use before trusting it.

 -- Metodo: POP3.uidl (which=None)

     Return message digest (unique id) list.  If 'which' is specified,
     result contains the unique id for that message in the form
     ‘'response mesgnum uid’, otherwise result is list ‘(response,
     ['mesgnum uid', ...], octets)’.

 -- Metodo: POP3.utf8 ()

     Try to switch to UTF-8 mode.  Returns the server response if
     successful, raises *note error_proto: 13a4. if not.  Specified in
     RFC 6856(2).

     Added in version 3.5.

 -- Metodo: POP3.stls (context=None)

     Start a TLS session on the active connection as specified in RFC
     2595(3).  This is only allowed before user authentication

     'context' parameter is a *note ssl.SSLContext: 357. object which
     allows bundling SSL configuration options, certificates and private
     keys into a single (potentially long-lived) structure.  Please read
     *note Security considerations: 387b. for best practices.

     This method supports hostname checking via *note
     ssl.SSLContext.check_hostname: 39aa. and 'Server Name Indication'
     (see *note ssl.HAS_SNI: 39bc.).

     Added in version 3.4.

Instances of *note POP3_SSL: b20. have no additional methods.  The
interface of this subclass is identical to its parent.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2449.html

   (2) https://datatracker.ietf.org/doc/html/rfc6856.html

   (3) https://datatracker.ietf.org/doc/html/rfc2595.html


File: python.info,  Node: POP3 Example,  Prev: POP3 Objects,  Up: poplib — POP3 protocol client

5.22.12.2 POP3 Example
......................

Here is a minimal example (without error checking) that opens a mailbox
and retrieves and prints all messages:

     import getpass, poplib

     M = poplib.POP3('localhost')
     M.user(getpass.getuser())
     M.pass_(getpass.getpass())
     numMessages = len(M.list()[1])
     for i in range(numMessages):
         for j in M.retr(i+1)[1]:
             print(j)

At the end of the module, there is a test section that contains a more
extensive example of usage.


File: python.info,  Node: imaplib — IMAP4 protocol client,  Next: smtplib — SMTP protocol client,  Prev: poplib — POP3 protocol client,  Up: Internet Protocols and Support

5.22.13 ‘imaplib’ — IMAP4 protocol client
-----------------------------------------

'Source code:' Lib/imaplib.py(1)

__________________________________________________________________

This module defines three classes, *note IMAP4: b01, *note IMAP4_SSL:
b02. and *note IMAP4_stream: b04, which encapsulate a connection to an
IMAP4 server and implement a large subset of the IMAP4rev1 client
protocol as defined in RFC 2060(2).  It is backward compatible with
IMAP4 ( RFC 1730(3)) servers, but note that the ‘STATUS’ command is not
supported in IMAP4.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

Three classes are provided by the *note imaplib: 78. module, *note
IMAP4: b01. is the base class:

 -- Classe: imaplib.IMAP4 (host='', port=IMAP4_PORT, timeout=None)

     This class implements the actual IMAP4 protocol.  The connection is
     created and protocol version (IMAP4 or IMAP4rev1) is determined
     when the instance is initialized.  If 'host' is not specified, ‘''’
     (the local host) is used.  If 'port' is omitted, the standard IMAP4
     port (143) is used.  The optional 'timeout' parameter specifies a
     timeout in seconds for the connection attempt.  If timeout is not
     given or is ‘None’, the global default socket timeout is used.

     The *note IMAP4: b01. class supports the *note with: 186.
     statement.  When used like this, the IMAP4 ‘LOGOUT’ command is
     issued automatically when the ‘with’ statement exits.  E.g.:

          >>> from imaplib import IMAP4
          >>> with IMAP4("domain.org") as M:
          ...     M.noop()
          ...
          ('OK', [b'Nothing Accomplished. d25if65hy903weo.87'])

     Cambiato nella versione 3.5: Support for the *note with: 186.
     statement was added.

     Cambiato nella versione 3.9: The optional 'timeout' parameter was
     added.

Three exceptions are defined as attributes of the *note IMAP4: b01.
class:

 -- Eccezione: IMAP4.error

     Exception raised on any errors.  The reason for the exception is
     passed to the constructor as a string.

 -- Eccezione: IMAP4.abort

     IMAP4 server errors cause this exception to be raised.  This is a
     sub-class of *note IMAP4.error: 17df.  Note that closing the
     instance and instantiating a new one will usually allow recovery
     from this exception.

 -- Eccezione: IMAP4.readonly

     This exception is raised when a writable mailbox has its status
     changed by the server.  This is a sub-class of *note IMAP4.error:
     17df.  Some other client now has write permission, and the mailbox
     will need to be re-opened to re-obtain write permission.

There’s also a subclass for secure connections:

 -- Classe: imaplib.IMAP4_SSL (host='', port=IMAP4_SSL_PORT, *,
          ssl_context=None, timeout=None)

     This is a subclass derived from *note IMAP4: b01. that connects
     over an SSL encrypted socket (to use this class you need a socket
     module that was compiled with SSL support).  If 'host' is not
     specified, ‘''’ (the local host) is used.  If 'port' is omitted,
     the standard IMAP4-over-SSL port (993) is used.  'ssl_context' is a
     *note ssl.SSLContext: 357. object which allows bundling SSL
     configuration options, certificates and private keys into a single
     (potentially long-lived) structure.  Please read *note Security
     considerations: 387b. for best practices.

     The optional 'timeout' parameter specifies a timeout in seconds for
     the connection attempt.  If timeout is not given or is ‘None’, the
     global default socket timeout is used.

     Cambiato nella versione 3.3: 'ssl_context' parameter was added.

     Cambiato nella versione 3.4: The class now supports hostname check
     with *note ssl.SSLContext.check_hostname: 39aa. and 'Server Name
     Indication' (see *note ssl.HAS_SNI: 39bc.).

     Cambiato nella versione 3.9: The optional 'timeout' parameter was
     added.

     Cambiato nella versione 3.12: The deprecated 'keyfile' and
     'certfile' parameters have been removed.

The second subclass allows for connections created by a child process:

 -- Classe: imaplib.IMAP4_stream (command)

     This is a subclass derived from *note IMAP4: b01. that connects to
     the ‘stdin/stdout’ file descriptors created by passing 'command' to
     ‘subprocess.Popen()’.

The following utility functions are defined:

 -- Funzione: imaplib.Internaldate2tuple (datestr)

     Parse an IMAP4 ‘INTERNALDATE’ string and return corresponding local
     time.  The return value is a *note time.struct_time: ee8. tuple or
     ‘None’ if the string has wrong format.

 -- Funzione: imaplib.Int2AP (num)

     Converts an integer into a bytes representation using characters
     from the set [‘A’ ..  ‘P’].

 -- Funzione: imaplib.ParseFlags (flagstr)

     Converts an IMAP4 ‘FLAGS’ response to a tuple of individual flags.

 -- Funzione: imaplib.Time2Internaldate (date_time)

     Convert 'date_time' to an IMAP4 ‘INTERNALDATE’ representation.  The
     return value is a string in the form: ‘"DD-Mmm-YYYY HH:MM:SS
     +HHMM"’ (including double-quotes).  The 'date_time' argument can be
     a number (int or float) representing seconds since epoch (as
     returned by *note time.time(): 55d.), a 9-tuple representing local
     time an instance of *note time.struct_time: ee8. (as returned by
     *note time.localtime(): 1700.), an aware instance of *note
     datetime.datetime: 4e3, or a double-quoted string.  In the last
     case, it is assumed to already be in the correct format.

Note that IMAP4 message numbers change as the mailbox changes; in
particular, after an ‘EXPUNGE’ command performs deletions the remaining
messages are renumbered.  So it is highly advisable to use UIDs instead,
with the UID command.

At the end of the module, there is a test section that contains a more
extensive example of usage.

Vedi anche
..........

Documents describing the protocol, sources for servers implementing it,
by the University of Washington’s IMAP Information Center can all be
found at ('Source Code') ‘https://github.com/uw-imap/imap’ ('Not
Maintained').

* Menu:

* IMAP4 Objects::
* IMAP4 Example::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/imaplib.py

   (2) https://datatracker.ietf.org/doc/html/rfc2060.html

   (3) https://datatracker.ietf.org/doc/html/rfc1730.html


File: python.info,  Node: IMAP4 Objects,  Next: IMAP4 Example,  Up: imaplib — IMAP4 protocol client

5.22.13.1 IMAP4 Objects
.......................

All IMAP4rev1 commands are represented by methods of the same name,
either uppercase or lowercase.

All arguments to commands are converted to strings, except for
‘AUTHENTICATE’, and the last argument to ‘APPEND’ which is passed as an
IMAP4 literal.  If necessary (the string contains IMAP4
protocol-sensitive characters and isn’t enclosed with either parentheses
or double quotes) each string is quoted.  However, the 'password'
argument to the ‘LOGIN’ command is always quoted.  If you want to avoid
having an argument string quoted (eg: the 'flags' argument to ‘STORE’)
then enclose the string in parentheses (eg: ‘r'(\Deleted)'’).

Most commands return a tuple: ‘(type, [data, ...])’ where 'type' is
usually ‘'OK'’ or ‘'NO'’, and 'data' is either the text from the command
response, or mandated results from the command.  Each 'data' is either a
‘bytes’, or a tuple.  If a tuple, then the first part is the header of
the response, and the second part contains the data (ie: “literal”
value).

The 'message_set' options to commands below is a string specifying one
or more messages to be acted upon.  It may be a simple message number
(‘'1'’), a range of message numbers (‘'2:4'’), or a group of
non-contiguous ranges separated by commas (‘'1:3,6:9'’).  A range can
contain an asterisk to indicate an infinite upper bound (‘'3:*'’).

An *note IMAP4: b01. instance has the following methods:

 -- Metodo: IMAP4.append (mailbox, flags, date_time, message)

     Append 'message' to named mailbox.

 -- Metodo: IMAP4.authenticate (mechanism, authobject)

     Authenticate command — requires response processing.

     'mechanism' specifies which authentication mechanism is to be used
     - it should appear in the instance variable ‘capabilities’ in the
     form ‘AUTH=mechanism’.

     'authobject' must be a callable object:

          data = authobject(response)

     It will be called to process server continuation responses; the
     'response' argument it is passed will be ‘bytes’.  It should return
     ‘bytes’ 'data' that will be base64 encoded and sent to the server.
     It should return ‘None’ if the client abort response ‘*’ should be
     sent instead.

     Cambiato nella versione 3.5: string usernames and passwords are now
     encoded to ‘utf-8’ instead of being limited to ASCII.

 -- Metodo: IMAP4.check ()

     Checkpoint mailbox on server.

 -- Metodo: IMAP4.close ()

     Close currently selected mailbox.  Deleted messages are removed
     from writable mailbox.  This is the recommended command before
     ‘LOGOUT’.

 -- Metodo: IMAP4.copy (message_set, new_mailbox)

     Copy 'message_set' messages onto end of 'new_mailbox'.

 -- Metodo: IMAP4.create (mailbox)

     Create new mailbox named 'mailbox'.

 -- Metodo: IMAP4.delete (mailbox)

     Delete old mailbox named 'mailbox'.

 -- Metodo: IMAP4.deleteacl (mailbox, who)

     Delete the ACLs (remove any rights) set for who on mailbox.

 -- Metodo: IMAP4.enable (capability)

     Enable 'capability' (see RFC 5161(1)).  Most capabilities do not
     need to be enabled.  Currently only the ‘UTF8=ACCEPT’ capability is
     supported (see RFC 6855(2)).

     Added in version 3.5: The *note enable(): 1010. method itself, and
     RFC 6855(3) support.

 -- Metodo: IMAP4.expunge ()

     Permanently remove deleted items from selected mailbox.  Generates
     an ‘EXPUNGE’ response for each deleted message.  Returned data
     contains a list of ‘EXPUNGE’ message numbers in order received.

 -- Metodo: IMAP4.fetch (message_set, message_parts)

     Fetch (parts of) messages.  'message_parts' should be a string of
     message part names enclosed within parentheses, eg: ‘"(UID
     BODY[TEXT])"’.  Returned data are tuples of message part envelope
     and data.

 -- Metodo: IMAP4.getacl (mailbox)

     Get the ‘ACL’s for 'mailbox'.  The method is non-standard, but is
     supported by the ‘Cyrus’ server.

 -- Metodo: IMAP4.getannotation (mailbox, entry, attribute)

     Retrieve the specified ‘ANNOTATION’s for 'mailbox'.  The method is
     non-standard, but is supported by the ‘Cyrus’ server.

 -- Metodo: IMAP4.getquota (root)

     Get the ‘quota’ 'root'’s resource usage and limits.  This method is
     part of the IMAP4 QUOTA extension defined in rfc2087.

 -- Metodo: IMAP4.getquotaroot (mailbox)

     Get the list of ‘quota’ ‘roots’ for the named 'mailbox'.  This
     method is part of the IMAP4 QUOTA extension defined in rfc2087.

 -- Metodo: IMAP4.idle (duration=None)

     Return an ‘Idler’: an iterable context manager implementing the
     IMAP4 ‘IDLE’ command as defined in RFC 2177(4).

     The returned object sends the ‘IDLE’ command when activated by the
     *note with: 186. statement, produces IMAP untagged responses via
     the *note iterator: 4c9. protocol, and sends ‘DONE’ upon context
     exit.

     All untagged responses that arrive after sending the ‘IDLE’ command
     (including any that arrive before the server acknowledges the
     command) will be available via iteration.  Any leftover responses
     (those not iterated in the *note with: 186. context) can be
     retrieved in the usual way after ‘IDLE’ ends, using *note
     IMAP4.response(): 4031.

     Responses are represented as ‘(type, [data, ...])’ tuples, as
     described in *note IMAP4 Objects: 4023.

     The 'duration' argument sets a maximum duration (in seconds) to
     keep idling, after which any ongoing iteration will stop.  It can
     be an *note int: 19b. or *note float: 196, or ‘None’ for no time
     limit.  Callers wishing to avoid inactivity timeouts on servers
     that impose them should keep this at most 29 minutes (1740
     seconds).  Requires a socket connection; 'duration' must be ‘None’
     on *note IMAP4_stream: b04. connections.

          >>> with M.idle(duration=29 * 60) as idler:
          ...     for typ, data in idler:
          ...         print(typ, data)
          ...
          EXISTS [b'1']
          RECENT [b'1']

      -- Metodo: Idler.burst (interval=0.1)

          Yield a burst of responses no more than 'interval' seconds
          apart (expressed as an *note int: 19b. or *note float: 196.).

          This *note generator: 1263. is an alternative to iterating one
          response at a time, intended to aid in efficient batch
          processing.  It retrieves the next response along with any
          immediately available subsequent responses.  (For example, a
          rapid series of ‘EXPUNGE’ responses after a bulk delete.)

          Requires a socket connection; does not work on *note
          IMAP4_stream: b04. connections.

               >>> with M.idle() as idler:
               ...     # get a response and any others following by < 0.1 seconds
               ...     batch = list(idler.burst())
               ...     print(f'processing {len(batch)} responses...')
               ...     print(batch)
               ...
               processing 3 responses...
               [('EXPUNGE', [b'2']), ('EXPUNGE', [b'1']), ('RECENT', [b'0'])]

               Suggerimento: The ‘IDLE’ context’s maximum duration, as
               passed to *note IMAP4.idle(): 22d, is respected when
               waiting for the first response in a burst.  Therefore, an
               expired ‘Idler’ will cause this generator to return
               immediately without producing anything.  Callers should
               consider this if using it in a loop.

          Nota: The iterator returned by *note IMAP4.idle(): 22d. is
          usable only within a *note with: 186. statement.  Before or
          after that context, unsolicited responses are collected
          internally whenever a command finishes, and can be retrieved
          with *note IMAP4.response(): 4031.

          Nota: The ‘Idler’ class name and structure are internal
          interfaces, subject to change.  Calling code can rely on its
          context management, iteration, and public method to remain
          stable, but should not subclass, instantiate, compare, or
          otherwise directly reference the class.

     Added in version 3.14.

 -- Metodo: IMAP4.list ([directory[, pattern]])

     List mailbox names in 'directory' matching 'pattern'.  'directory'
     defaults to the top-level mail folder, and 'pattern' defaults to
     match anything.  Returned data contains a list of ‘LIST’ responses.

 -- Metodo: IMAP4.login (user, password)

     Identify the client using a plaintext password.  The 'password'
     will be quoted.

 -- Metodo: IMAP4.login_cram_md5 (user, password)

     Force use of ‘CRAM-MD5’ authentication when identifying the client
     to protect the password.  Will only work if the server ‘CAPABILITY’
     response includes the phrase ‘AUTH=CRAM-MD5’.

     Cambiato nella versione 3.14: An *note IMAP4.error: 17df. is raised
     if MD5 support is not available.

 -- Metodo: IMAP4.logout ()

     Shutdown connection to server.  Returns server ‘BYE’ response.

     Cambiato nella versione 3.8: The method no longer ignores silently
     arbitrary exceptions.

 -- Metodo: IMAP4.lsub (directory='""', pattern='*')

     List subscribed mailbox names in directory matching pattern.
     'directory' defaults to the top level directory and 'pattern'
     defaults to match any mailbox.  Returned data are tuples of message
     part envelope and data.

 -- Metodo: IMAP4.myrights (mailbox)

     Show my ACLs for a mailbox (i.e.  the rights that I have on
     mailbox).

 -- Metodo: IMAP4.namespace ()

     Returns IMAP namespaces as defined in RFC 2342(5).

 -- Metodo: IMAP4.noop ()

     Send ‘NOOP’ to server.

 -- Metodo: IMAP4.open (host, port, timeout=None)

     Opens socket to 'port' at 'host'.  The optional 'timeout' parameter
     specifies a timeout in seconds for the connection attempt.  If
     timeout is not given or is ‘None’, the global default socket
     timeout is used.  Also note that if the 'timeout' parameter is set
     to be zero, it will raise a *note ValueError: 2ec. to reject
     creating a non-blocking socket.  This method is implicitly called
     by the *note IMAP4: b01. constructor.  The connection objects
     established by this method will be used in the *note IMAP4.read():
     4039, *note IMAP4.readline(): 403a, *note IMAP4.send(): 403b, and
     *note IMAP4.shutdown(): 403c. methods.  You may override this
     method.

     Raises an *note auditing event: 1c56. ‘imaplib.open’ with arguments
     ‘self’, ‘host’, ‘port’.

     Cambiato nella versione 3.9: The 'timeout' parameter was added.

 -- Metodo: IMAP4.partial (message_num, message_part, start, length)

     Fetch truncated part of a message.  Returned data is a tuple of
     message part envelope and data.

 -- Metodo: IMAP4.proxyauth (user)

     Assume authentication as 'user'.  Allows an authorised
     administrator to proxy into any user’s mailbox.

 -- Metodo: IMAP4.read (size)

     Reads 'size' bytes from the remote server.  You may override this
     method.

 -- Metodo: IMAP4.readline ()

     Reads one line from the remote server.  You may override this
     method.

 -- Metodo: IMAP4.recent ()

     Prompt server for an update.  Returned data is ‘None’ if no new
     messages, else value of ‘RECENT’ response.

 -- Metodo: IMAP4.rename (oldmailbox, newmailbox)

     Rename mailbox named 'oldmailbox' to 'newmailbox'.

 -- Metodo: IMAP4.response (code)

     Return data for response 'code' if received, or ‘None’.  Returns
     the given code, instead of the usual type.

 -- Metodo: IMAP4.search (charset, criterion[, ...])

     Search mailbox for matching messages.  'charset' may be ‘None’, in
     which case no ‘CHARSET’ will be specified in the request to the
     server.  The IMAP protocol requires that at least one criterion be
     specified; an exception will be raised when the server returns an
     error.  'charset' must be ‘None’ if the ‘UTF8=ACCEPT’ capability
     was enabled using the *note enable(): 1010. command.

     Example:

          # M is a connected IMAP4 instance...
          typ, msgnums = M.search(None, 'FROM', '"LDJ"')

          # or:
          typ, msgnums = M.search(None, '(FROM "LDJ")')

 -- Metodo: IMAP4.select (mailbox='INBOX', readonly=False)

     Select a mailbox.  Returned data is the count of messages in
     'mailbox' (‘EXISTS’ response).  The default 'mailbox' is ‘'INBOX'’.
     If the 'readonly' flag is set, modifications to the mailbox are not
     allowed.

 -- Metodo: IMAP4.send (data)

     Sends ‘data’ to the remote server.  You may override this method.

     Raises an *note auditing event: 1c56. ‘imaplib.send’ with arguments
     ‘self’, ‘data’.

 -- Metodo: IMAP4.setacl (mailbox, who, what)

     Set an ‘ACL’ for 'mailbox'.  The method is non-standard, but is
     supported by the ‘Cyrus’ server.

 -- Metodo: IMAP4.setannotation (mailbox, entry, attribute[, ...])

     Set ‘ANNOTATION’s for 'mailbox'.  The method is non-standard, but
     is supported by the ‘Cyrus’ server.

 -- Metodo: IMAP4.setquota (root, limits)

     Set the ‘quota’ 'root'’s resource 'limits'.  This method is part of
     the IMAP4 QUOTA extension defined in rfc2087.

 -- Metodo: IMAP4.shutdown ()

     Close connection established in ‘open’.  This method is implicitly
     called by *note IMAP4.logout(): c86.  You may override this method.

 -- Metodo: IMAP4.socket ()

     Returns socket instance used to connect to server.

 -- Metodo: IMAP4.sort (sort_criteria, charset, search_criterion[, ...])

     The ‘sort’ command is a variant of ‘search’ with sorting semantics
     for the results.  Returned data contains a space separated list of
     matching message numbers.

     Sort has two arguments before the 'search_criterion' argument(s); a
     parenthesized list of 'sort_criteria', and the searching 'charset'.
     Note that unlike ‘search’, the searching 'charset' argument is
     mandatory.  There is also a ‘uid sort’ command which corresponds to
     ‘sort’ the way that ‘uid search’ corresponds to ‘search’.  The
     ‘sort’ command first searches the mailbox for messages that match
     the given searching criteria using the charset argument for the
     interpretation of strings in the searching criteria.  It then
     returns the numbers of matching messages.

     This is an ‘IMAP4rev1’ extension command.

 -- Metodo: IMAP4.starttls (ssl_context=None)

     Send a ‘STARTTLS’ command.  The 'ssl_context' argument is optional
     and should be a *note ssl.SSLContext: 357. object.  This will
     enable encryption on the IMAP connection.  Please read *note
     Security considerations: 387b. for best practices.

     Added in version 3.2.

     Cambiato nella versione 3.4: The method now supports hostname check
     with *note ssl.SSLContext.check_hostname: 39aa. and 'Server Name
     Indication' (see *note ssl.HAS_SNI: 39bc.).

 -- Metodo: IMAP4.status (mailbox, names)

     Request named status conditions for 'mailbox'.

 -- Metodo: IMAP4.store (message_set, command, flag_list)

     Alters flag dispositions for messages in mailbox.  'command' is
     specified by section 6.4.6 of RFC 2060(6) as being one of «FLAGS»,
     «+FLAGS», or «-FLAGS», optionally with a suffix of «.SILENT».

     For example, to set the delete flag on all messages:

          typ, data = M.search(None, 'ALL')
          for num in data[0].split():
             M.store(num, '+FLAGS', '\\Deleted')
          M.expunge()

          Nota: Creating flags containing “]” (for example: «[test]»)
          violates RFC 3501(7) (the IMAP protocol).  However, imaplib
          has historically allowed creation of such tags, and popular
          IMAP servers, such as Gmail, accept and produce such flags.
          There are non-Python programs which also create such tags.
          Although it is an RFC violation and IMAP clients and servers
          are supposed to be strict, imaplib still continues to allow
          such tags to be created for backward compatibility reasons,
          and as of Python 3.6, handles them if they are sent from the
          server, since this improves real-world compatibility.

 -- Metodo: IMAP4.subscribe (mailbox)

     Subscribe to new mailbox.

 -- Metodo: IMAP4.thread (threading_algorithm, charset,
          search_criterion[, ...])

     The ‘thread’ command is a variant of ‘search’ with threading
     semantics for the results.  Returned data contains a space
     separated list of thread members.

     Thread members consist of zero or more messages numbers, delimited
     by spaces, indicating successive parent and child.

     Thread has two arguments before the 'search_criterion' argument(s);
     a 'threading_algorithm', and the searching 'charset'.  Note that
     unlike ‘search’, the searching 'charset' argument is mandatory.
     There is also a ‘uid thread’ command which corresponds to ‘thread’
     the way that ‘uid search’ corresponds to ‘search’.  The ‘thread’
     command first searches the mailbox for messages that match the
     given searching criteria using the 'charset' argument for the
     interpretation of strings in the searching criteria.  It then
     returns the matching messages threaded according to the specified
     threading algorithm.

     This is an ‘IMAP4rev1’ extension command.

 -- Metodo: IMAP4.uid (command, arg[, ...])

     Execute command args with messages identified by UID, rather than
     message number.  Returns response appropriate to command.  At least
     one argument must be supplied; if none are provided, the server
     will return an error and an exception will be raised.

 -- Metodo: IMAP4.unsubscribe (mailbox)

     Unsubscribe from old mailbox.

 -- Metodo: IMAP4.unselect ()

     *note imaplib.IMAP4.unselect(): b05. frees server’s resources
     associated with the selected mailbox and returns the server to the
     authenticated state.  This command performs the same actions as
     *note imaplib.IMAP4.close(): b06, except that no messages are
     permanently removed from the currently selected mailbox.

     Added in version 3.9.

 -- Metodo: IMAP4.xatom (name[, ...])

     Allow simple extension commands notified by server in ‘CAPABILITY’
     response.

The following attributes are defined on instances of *note IMAP4: b01.:

 -- Attributo: IMAP4.PROTOCOL_VERSION

     The most recent supported protocol in the ‘CAPABILITY’ response
     from the server.

 -- Attributo: IMAP4.debug

     Integer value to control debugging output.  The initialize value is
     taken from the module variable ‘Debug’.  Values greater than three
     trace each command.

 -- Attributo: IMAP4.utf8_enabled

     Boolean value that is normally ‘False’, but is set to ‘True’ if an
     *note enable(): 1010. command is successfully issued for the
     ‘UTF8=ACCEPT’ capability.

     Added in version 3.5.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc5161.html

   (2) https://datatracker.ietf.org/doc/html/rfc6855.html

   (3) https://datatracker.ietf.org/doc/html/rfc6855.html

   (4) https://datatracker.ietf.org/doc/html/rfc2177.html

   (5) https://datatracker.ietf.org/doc/html/rfc2342.html

   (6) https://datatracker.ietf.org/doc/html/rfc2060.html

   (7) https://datatracker.ietf.org/doc/html/rfc3501.html


File: python.info,  Node: IMAP4 Example,  Prev: IMAP4 Objects,  Up: imaplib — IMAP4 protocol client

5.22.13.2 IMAP4 Example
.......................

Here is a minimal example (without error checking) that opens a mailbox
and retrieves and prints all messages:

     import getpass, imaplib

     M = imaplib.IMAP4(host='example.org')
     M.login(getpass.getuser(), getpass.getpass())
     M.select()
     typ, data = M.search(None, 'ALL')
     for num in data[0].split():
         typ, data = M.fetch(num, '(RFC822)')
         print('Message %s\n%s\n' % (num, data[0][1]))
     M.close()
     M.logout()


File: python.info,  Node: smtplib — SMTP protocol client,  Next: uuid — UUID objects according to RFC 9562,  Prev: imaplib — IMAP4 protocol client,  Up: Internet Protocols and Support

5.22.14 ‘smtplib’ — SMTP protocol client
----------------------------------------

'Source code:' Lib/smtplib.py(1)

__________________________________________________________________

The *note smtplib: cf. module defines an SMTP client session object that
can be used to send mail to any internet machine with an SMTP or ESMTP
listener daemon.  For details of SMTP and ESMTP operation, consult RFC
821(2) (Simple Mail Transfer Protocol) and RFC 1869(3) (SMTP Service
Extensions).

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

 -- Classe: smtplib.SMTP (host='', port=0, local_hostname=None[,
          timeout], source_address=None)

     An *note SMTP: b29. instance encapsulates an SMTP connection.  It
     has methods that support a full repertoire of SMTP and ESMTP
     operations.  If the optional 'host' and 'port' parameters are
     given, the SMTP *note connect(): 1d97. method is called with those
     parameters during initialization.  If specified, 'local_hostname'
     is used as the FQDN of the local host in the HELO/EHLO command.
     Otherwise, the local hostname is found using *note
     socket.getfqdn(): 1ad5.  If the *note connect(): 1d97. call returns
     anything other than a success code, an *note SMTPConnectError:
     4056. is raised.  The optional 'timeout' parameter specifies a
     timeout in seconds for blocking operations like the connection
     attempt (if not specified, the global default timeout setting will
     be used).  If the timeout expires, *note TimeoutError: a38. is
     raised.  The optional 'source_address' parameter allows binding to
     some specific source address in a machine with multiple network
     interfaces, and/or to some specific source TCP port.  It takes a
     2-tuple ‘(host, port)’, for the socket to bind to as its source
     address before connecting.  If omitted (or if 'host' or 'port' are
     ‘''’ and/or ‘0’ respectively) the OS default behavior will be used.

     For normal use, you should only require the initialization/connect,
     *note sendmail(): 105b, and *note SMTP.quit(): 4057. methods.  An
     example is included below.

     The *note SMTP: b29. class supports the *note with: 186. statement.
     When used like this, the SMTP ‘QUIT’ command is issued
     automatically when the ‘with’ statement exits.  E.g.:

          >>> from smtplib import SMTP
          >>> with SMTP("domain.org") as smtp:
          ...     smtp.noop()
          ...
          (250, b'Ok')
          >>>

     All commands will raise an *note auditing event: 1c56.
     ‘smtplib.SMTP.send’ with arguments ‘self’ and ‘data’, where ‘data’
     is the bytes about to be sent to the remote host.

     Cambiato nella versione 3.3: Support for the *note with: 186.
     statement was added.

     Cambiato nella versione 3.3: 'source_address' argument was added.

     Added in version 3.5: The SMTPUTF8 extension ( RFC 6531(4)) is now
     supported.

     Cambiato nella versione 3.9: If the 'timeout' parameter is set to
     be zero, it will raise a *note ValueError: 2ec. to prevent the
     creation of a non-blocking socket.

 -- Classe: smtplib.SMTP_SSL (host='', port=0, local_hostname=None, *[,
          timeout], context=None, source_address=None)

     An *note SMTP_SSL: b2a. instance behaves exactly the same as
     instances of *note SMTP: b29.  *note SMTP_SSL: b2a. should be used
     for situations where SSL is required from the beginning of the
     connection and using *note starttls(): 1340. is not appropriate.
     If 'host' is not specified, the local host is used.  If 'port' is
     zero, the standard SMTP-over-SSL port (465) is used.  The optional
     arguments 'local_hostname', 'timeout' and 'source_address' have the
     same meaning as they do in the *note SMTP: b29. class.  'context',
     also optional, can contain a *note SSLContext: 357. and allows
     configuring various aspects of the secure connection.  Please read
     *note Security considerations: 387b. for best practices.

     Cambiato nella versione 3.3: 'context' was added.

     Cambiato nella versione 3.3: The 'source_address' argument was
     added.

     Cambiato nella versione 3.4: The class now supports hostname check
     with *note ssl.SSLContext.check_hostname: 39aa. and 'Server Name
     Indication' (see *note ssl.HAS_SNI: 39bc.).

     Cambiato nella versione 3.9: If the 'timeout' parameter is set to
     be zero, it will raise a *note ValueError: 2ec. to prevent the
     creation of a non-blocking socket

     Cambiato nella versione 3.12: The deprecated 'keyfile' and
     'certfile' parameters have been removed.

 -- Classe: smtplib.LMTP (host='', port=LMTP_PORT, local_hostname=None,
          source_address=None[, timeout])

     The LMTP protocol, which is very similar to ESMTP, is heavily based
     on the standard SMTP client.  It’s common to use Unix sockets for
     LMTP, so our *note connect(): 1d97. method must support that as
     well as a regular host:port server.  The optional arguments
     'local_hostname' and 'source_address' have the same meaning as they
     do in the *note SMTP: b29. class.  To specify a Unix socket, you
     must use an absolute path for 'host', starting with a “/”.

     Authentication is supported, using the regular SMTP mechanism.
     When using a Unix socket, LMTP generally don’t support or require
     any authentication, but your mileage might vary.

     Cambiato nella versione 3.9: The optional 'timeout' parameter was
     added.

A nice selection of exceptions is defined as well:

 -- Eccezione: smtplib.SMTPException

     Subclass of *note OSError: 2c0. that is the base exception class
     for all the other exceptions provided by this module.

     Cambiato nella versione 3.4: SMTPException became subclass of *note
     OSError: 2c0.

 -- Eccezione: smtplib.SMTPServerDisconnected

     This exception is raised when the server unexpectedly disconnects,
     or when an attempt is made to use the *note SMTP: b29. instance
     before connecting it to a server.

 -- Eccezione: smtplib.SMTPResponseException

     Base class for all exceptions that include an SMTP error code.
     These exceptions are generated in some instances when the SMTP
     server returns an error code.

      -- Attributo: smtp_code

          The error code.

      -- Attributo: smtp_error

          The error message.

 -- Eccezione: smtplib.SMTPSenderRefused

     Sender address refused.  In addition to the attributes set by on
     all *note SMTPResponseException: 4059. exceptions, this sets
     “sender” to the string that the SMTP server refused.

 -- Eccezione: smtplib.SMTPRecipientsRefused

     All recipient addresses refused.

      -- Attributo: recipients

          A dictionary of exactly the same sort as returned by *note
          SMTP.sendmail(): 105b. containing the errors for each
          recipient.

 -- Eccezione: smtplib.SMTPDataError

     The SMTP server refused to accept the message data.

 -- Eccezione: smtplib.SMTPConnectError

     Error occurred during establishment of a connection with the
     server.

 -- Eccezione: smtplib.SMTPHeloError

     The server refused our ‘HELO’ message.

 -- Eccezione: smtplib.SMTPNotSupportedError

     The command or option attempted is not supported by the server.

     Added in version 3.5.

 -- Eccezione: smtplib.SMTPAuthenticationError

     SMTP authentication went wrong.  Most probably the server didn’t
     accept the username/password combination provided.

Vedi anche
..........

RFC 821(5) - Simple Mail Transfer Protocol

     Protocol definition for SMTP. This document covers the model,
     operating procedure, and protocol details for SMTP.

RFC 1869(6) - SMTP Service Extensions

     Definition of the ESMTP extensions for SMTP. This describes a
     framework for extending SMTP with new commands, supporting dynamic
     discovery of the commands provided by the server, and defines a few
     additional commands.

* Menu:

* SMTP Objects::
* SMTP Example::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/smtplib.py

   (2) https://datatracker.ietf.org/doc/html/rfc821.html

   (3) https://datatracker.ietf.org/doc/html/rfc1869.html

   (4) https://datatracker.ietf.org/doc/html/rfc6531.html

   (5) https://datatracker.ietf.org/doc/html/rfc821.html

   (6) https://datatracker.ietf.org/doc/html/rfc1869.html


File: python.info,  Node: SMTP Objects,  Next: SMTP Example,  Up: smtplib — SMTP protocol client

5.22.14.1 SMTP Objects
......................

An *note SMTP: b29. instance has the following methods:

 -- Metodo: SMTP.set_debuglevel (level)

     Set the debug output level.  A value of 1 or ‘True’ for 'level'
     results in debug messages for connection and for all messages sent
     to and received from the server.  A value of 2 for 'level' results
     in these messages being timestamped.

     Cambiato nella versione 3.5: Added debuglevel 2.

 -- Metodo: SMTP.docmd (cmd, args='')

     Send a command 'cmd' to the server.  The optional argument 'args'
     is simply concatenated to the command, separated by a space.

     This returns a 2-tuple composed of a numeric response code and the
     actual response line (multiline responses are joined into one long
     line.)

     In normal operation it should not be necessary to call this method
     explicitly.  It is used to implement other methods and may be
     useful for testing private extensions.

     If the connection to the server is lost while waiting for the
     reply, *note SMTPServerDisconnected: 4058. will be raised.

 -- Metodo: SMTP.connect (host='localhost', port=0)

     Connect to a host on a given port.  The defaults are to connect to
     the local host at the standard SMTP port (25).  If the hostname
     ends with a colon (‘':'’) followed by a number, that suffix will be
     stripped off and the number interpreted as the port number to use.
     This method is automatically invoked by the constructor if a host
     is specified during instantiation.  Returns a 2-tuple of the
     response code and message sent by the server in its connection
     response.

     Raises an *note auditing event: 1c56. ‘smtplib.connect’ with
     arguments ‘self’, ‘host’, ‘port’.

 -- Metodo: SMTP.helo (name='')

     Identify yourself to the SMTP server using ‘HELO’.  The hostname
     argument defaults to the fully qualified domain name of the local
     host.  The message returned by the server is stored as the *note
     helo_resp: 4066. attribute of the object.

     In normal operation it should not be necessary to call this method
     explicitly.  It will be implicitly called by the *note sendmail():
     105b. when necessary.

 -- Metodo: SMTP.ehlo (name='')

     Identify yourself to an ESMTP server using ‘EHLO’.  The hostname
     argument defaults to the fully qualified domain name of the local
     host.  Examine the response for ESMTP option and store them for use
     by *note has_extn(): 4068.  Also sets several informational
     attributes: the message returned by the server is stored as the
     *note ehlo_resp: 4069. attribute, *note does_esmtp: 406a. is set to
     ‘True’ or ‘False’ depending on whether the server supports ESMTP,
     and *note esmtp_features: 406b. will be a dictionary containing the
     names of the SMTP service extensions this server supports, and
     their parameters (if any).

     Unless you wish to use *note has_extn(): 4068. before sending mail,
     it should not be necessary to call this method explicitly.  It will
     be implicitly called by *note sendmail(): 105b. when necessary.

 -- Metodo: SMTP.ehlo_or_helo_if_needed ()

     This method calls *note ehlo(): 4067. and/or *note helo(): 4065. if
     there has been no previous ‘EHLO’ or ‘HELO’ command this session.
     It tries ESMTP ‘EHLO’ first.

     *note SMTPHeloError: 4060.

          The server didn’t reply properly to the ‘HELO’ greeting.

 -- Metodo: SMTP.has_extn (name)

     Return *note True: e09. if 'name' is in the set of SMTP service
     extensions returned by the server, *note False: d2d. otherwise.
     Case is ignored.

 -- Metodo: SMTP.verify (address)

     Check the validity of an address on this server using SMTP ‘VRFY’.
     Returns a tuple consisting of code 250 and a full RFC 822(1)
     address (including human name) if the user address is valid.
     Otherwise returns an SMTP error code of 400 or greater and an error
     string.

          Nota: Many sites disable SMTP ‘VRFY’ in order to foil
          spammers.

 -- Metodo: SMTP.login (user, password, *, initial_response_ok=True)

     Log in on an SMTP server that requires authentication.  The
     arguments are the username and the password to authenticate with.
     If there has been no previous ‘EHLO’ or ‘HELO’ command this
     session, this method tries ESMTP ‘EHLO’ first.  This method will
     return normally if the authentication was successful, or may raise
     the following exceptions:

     *note SMTPHeloError: 4060.

          The server didn’t reply properly to the ‘HELO’ greeting.

     *note SMTPAuthenticationError: 4061.

          The server didn’t accept the username/password combination.

     *note SMTPNotSupportedError: 1d96.

          The ‘AUTH’ command is not supported by the server.

     *note SMTPException: 11a3.

          No suitable authentication method was found.

     Each of the authentication methods supported by *note smtplib: cf.
     are tried in turn if they are advertised as supported by the
     server.  See *note auth(): 1059. for a list of supported
     authentication methods.  'initial_response_ok' is passed through to
     *note auth(): 1059.

     Optional keyword argument 'initial_response_ok' specifies whether,
     for authentication methods that support it, an «initial response»
     as specified in RFC 4954(2) can be sent along with the ‘AUTH’
     command, rather than requiring a challenge/response.

     Cambiato nella versione 3.5: *note SMTPNotSupportedError: 1d96. may
     be raised, and the 'initial_response_ok' parameter was added.

 -- Metodo: SMTP.auth (mechanism, authobject, *,
          initial_response_ok=True)

     Issue an ‘SMTP’ ‘AUTH’ command for the specified authentication
     'mechanism', and handle the challenge response via 'authobject'.

     'mechanism' specifies which authentication mechanism is to be used
     as argument to the ‘AUTH’ command; the valid values are those
     listed in the ‘auth’ element of *note esmtp_features: 406b.

     'authobject' must be a callable object taking an optional single
     argument:

          data = authobject(challenge=None)

     If optional keyword argument 'initial_response_ok' is true,
     ‘authobject()’ will be called first with no argument.  It can
     return the RFC 4954(3) «initial response» ASCII ‘str’ which will be
     encoded and sent with the ‘AUTH’ command as below.  If the
     ‘authobject()’ does not support an initial response (e.g.  because
     it requires a challenge), it should return ‘None’ when called with
     ‘challenge=None’.  If 'initial_response_ok' is false, then
     ‘authobject()’ will not be called first with ‘None’.

     If the initial response check returns ‘None’, or if
     'initial_response_ok' is false, ‘authobject()’ will be called to
     process the server’s challenge response; the 'challenge' argument
     it is passed will be a ‘bytes’.  It should return ASCII ‘str’
     'data' that will be base64 encoded and sent to the server.

     The ‘SMTP’ class provides ‘authobjects’ for the ‘CRAM-MD5’,
     ‘PLAIN’, and ‘LOGIN’ mechanisms; they are named
     ‘SMTP.auth_cram_md5’, ‘SMTP.auth_plain’, and ‘SMTP.auth_login’
     respectively.  They all require that the ‘user’ and ‘password’
     properties of the ‘SMTP’ instance are set to appropriate values.

     User code does not normally need to call ‘auth’ directly, but can
     instead call the *note login(): 406e. method, which will try each
     of the above mechanisms in turn, in the order listed.  ‘auth’ is
     exposed to facilitate the implementation of authentication methods
     not (or not yet) supported directly by *note smtplib: cf.

     Added in version 3.5.

 -- Metodo: SMTP.starttls (*, context=None)

     Put the SMTP connection in TLS (Transport Layer Security) mode.
     All SMTP commands that follow will be encrypted.  You should then
     call *note ehlo(): 4067. again.

     If 'keyfile' and 'certfile' are provided, they are used to create
     an *note ssl.SSLContext: 357.

     Optional 'context' parameter is an *note ssl.SSLContext: 357.
     object; This is an alternative to using a keyfile and a certfile
     and if specified both 'keyfile' and 'certfile' should be ‘None’.

     If there has been no previous ‘EHLO’ or ‘HELO’ command this
     session, this method tries ESMTP ‘EHLO’ first.

     Cambiato nella versione 3.12: The deprecated 'keyfile' and
     'certfile' parameters have been removed.

     *note SMTPHeloError: 4060.

          The server didn’t reply properly to the ‘HELO’ greeting.

     *note SMTPNotSupportedError: 1d96.

          The server does not support the STARTTLS extension.

     *note RuntimeError: 244.

          SSL/TLS support is not available to your Python interpreter.

     Cambiato nella versione 3.3: 'context' was added.

     Cambiato nella versione 3.4: The method now supports hostname check
     with *note ssl.SSLContext.check_hostname: 39aa. and 'Server Name
     Indicator' (see *note HAS_SNI: 39bc.).

     Cambiato nella versione 3.5: The error raised for lack of STARTTLS
     support is now the *note SMTPNotSupportedError: 1d96. subclass
     instead of the base *note SMTPException: 11a3.

 -- Metodo: SMTP.sendmail (from_addr, to_addrs, msg, mail_options=(),
          rcpt_options=())

     Send mail.  The required arguments are an RFC 822(4) from-address
     string, a list of RFC 822(5) to-address strings (a bare string will
     be treated as a list with 1 address), and a message string.  The
     caller may pass a list of ESMTP options (such as ‘"8bitmime"’) to
     be used in ‘MAIL FROM’ commands as 'mail_options'.  ESMTP options
     (such as ‘DSN’ commands) that should be used with all ‘RCPT’
     commands can be passed as 'rcpt_options'.  Each option should be
     passed as a string containing the full text of the option,
     including any potential key (for instance,
     ‘"NOTIFY=SUCCESS,FAILURE"’).  (If you need to use different ESMTP
     options to different recipients you have to use the low-level
     methods such as ‘mail()’, ‘rcpt()’ and ‘data()’ to send the
     message.)

          Nota: The 'from_addr' and 'to_addrs' parameters are used to
          construct the message envelope used by the transport agents.
          ‘sendmail’ does not modify the message headers in any way.

     'msg' may be a string containing characters in the ASCII range, or
     a byte string.  A string is encoded to bytes using the ascii codec,
     and lone ‘\r’ and ‘\n’ characters are converted to ‘\r\n’
     characters.  A byte string is not modified.

     If there has been no previous ‘EHLO’ or ‘HELO’ command this
     session, this method tries ESMTP ‘EHLO’ first.  If the server does
     ESMTP, message size and each of the specified options will be
     passed to it (if the option is in the feature set the server
     advertises).  If ‘EHLO’ fails, ‘HELO’ will be tried and ESMTP
     options suppressed.

     This method will return normally if the mail is accepted for at
     least one recipient.  Otherwise it will raise an exception.  That
     is, if this method does not raise an exception, then someone should
     get your mail.  If this method does not raise an exception, it
     returns a dictionary, with one entry for each recipient that was
     refused.  Each entry contains a tuple of the SMTP error code and
     the accompanying error message sent by the server.

     If ‘SMTPUTF8’ is included in 'mail_options', and the server
     supports it, 'from_addr' and 'to_addrs' may contain non-ASCII
     characters.

     This method may raise the following exceptions:

     *note SMTPRecipientsRefused: 405d.

          All recipients were refused.  Nobody got the mail.

     *note SMTPHeloError: 4060.

          The server didn’t reply properly to the ‘HELO’ greeting.

     *note SMTPSenderRefused: 405c.

          The server didn’t accept the 'from_addr'.

     *note SMTPDataError: 405f.

          The server replied with an unexpected error code (other than a
          refusal of a recipient).

     *note SMTPNotSupportedError: 1d96.

          ‘SMTPUTF8’ was given in the 'mail_options' but is not
          supported by the server.

     Unless otherwise noted, the connection will be open even after an
     exception is raised.

     Cambiato nella versione 3.2: 'msg' may be a byte string.

     Cambiato nella versione 3.5: ‘SMTPUTF8’ support added, and *note
     SMTPNotSupportedError: 1d96. may be raised if ‘SMTPUTF8’ is
     specified but the server does not support it.

 -- Metodo: SMTP.send_message (msg, from_addr=None, to_addrs=None,
          mail_options=(), rcpt_options=())

     This is a convenience method for calling *note sendmail(): 105b.
     with the message represented by an *note email.message.Message:
     581. object.  The arguments have the same meaning as for *note
     sendmail(): 105b, except that 'msg' is a ‘Message’ object.

     If 'from_addr' is ‘None’ or 'to_addrs' is ‘None’, ‘send_message’
     fills those arguments with addresses extracted from the headers of
     'msg' as specified in RFC 5322(6): 'from_addr' is set to the
     ‘Sender’ field if it is present, and otherwise to the ‘From’ field.
     'to_addrs' combines the values (if any) of the ‘To’, ‘Cc’, and
     ‘Bcc’ fields from 'msg'.  If exactly one set of ‘Resent-*’ headers
     appear in the message, the regular headers are ignored and the
     ‘Resent-*’ headers are used instead.  If the message contains more
     than one set of ‘Resent-*’ headers, a *note ValueError: 2ec. is
     raised, since there is no way to unambiguously detect the most
     recent set of ‘Resent-’ headers.

     ‘send_message’ serializes 'msg' using *note BytesGenerator: 13d7.
     with ‘\r\n’ as the 'linesep', and calls *note sendmail(): 105b. to
     transmit the resulting message.  Regardless of the values of
     'from_addr' and 'to_addrs', ‘send_message’ does not transmit any
     ‘Bcc’ or ‘Resent-Bcc’ headers that may appear in 'msg'.  If any of
     the addresses in 'from_addr' and 'to_addrs' contain non-ASCII
     characters and the server does not advertise ‘SMTPUTF8’ support, an
     *note SMTPNotSupportedError: 1d96. is raised.  Otherwise the
     ‘Message’ is serialized with a clone of its *note policy: 53. with
     the *note utf8: ffb. attribute set to ‘True’, and ‘SMTPUTF8’ and
     ‘BODY=8BITMIME’ are added to 'mail_options'.

     Added in version 3.2.

     Added in version 3.5: Support for internationalized addresses
     (‘SMTPUTF8’).

 -- Metodo: SMTP.quit ()

     Terminate the SMTP session and close the connection.  Return the
     result of the SMTP ‘QUIT’ command.

Low-level methods corresponding to the standard SMTP/ESMTP commands
‘HELP’, ‘RSET’, ‘NOOP’, ‘MAIL’, ‘RCPT’, and ‘DATA’ are also supported.
Normally these do not need to be called directly, so they are not
documented here.  For details, consult the module code.

Additionally, an SMTP instance has the following attributes:

 -- Attributo: SMTP.helo_resp

     The response to the ‘HELO’ command, see *note helo(): 4065.

 -- Attributo: SMTP.ehlo_resp

     The response to the ‘EHLO’ command, see *note ehlo(): 4067.

 -- Attributo: SMTP.does_esmtp

     A boolean value indicating whether the server supports ESMTP, see
     *note ehlo(): 4067.

 -- Attributo: SMTP.esmtp_features

     A dictionary of the names of SMTP service extensions supported by
     the server, see *note ehlo(): 4067.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc822.html

   (2) https://datatracker.ietf.org/doc/html/rfc4954.html

   (3) https://datatracker.ietf.org/doc/html/rfc4954.html

   (4) https://datatracker.ietf.org/doc/html/rfc822.html

   (5) https://datatracker.ietf.org/doc/html/rfc822.html

   (6) https://datatracker.ietf.org/doc/html/rfc5322.html


File: python.info,  Node: SMTP Example,  Prev: SMTP Objects,  Up: smtplib — SMTP protocol client

5.22.14.2 SMTP Example
......................

This example prompts the user for addresses needed in the message
envelope (“To” and “From” addresses), and the message to be delivered.
Note that the headers to be included with the message must be included
in the message as entered; this example doesn’t do any processing of the
RFC 822(1) headers.  In particular, the “To” and “From” addresses must
be included in the message headers explicitly:

     import smtplib

     def prompt(title):
         return input(title).strip()

     from_addr = prompt("From: ")
     to_addrs  = prompt("To: ").split()
     print("Enter message, end with ^D (Unix) or ^Z (Windows):")

     # Add the From: and To: headers at the start!
     lines = [f"From: {from_addr}", f"To: {', '.join(to_addrs)}", ""]
     while True:
         try:
             line = input()
         except EOFError:
             break
         else:
             lines.append(line)

     msg = "\r\n".join(lines)
     print("Message length is", len(msg))

     server = smtplib.SMTP("localhost")
     server.set_debuglevel(1)
     server.sendmail(from_addr, to_addrs, msg)
     server.quit()

     Nota: In general, you will want to use the *note email: 3f.
     package’s features to construct an email message, which you can
     then send via *note send_message(): 105c.; see *note email;
     Examples: 113e.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc822.html


File: python.info,  Node: uuid — UUID objects according to RFC 9562,  Next: socketserver — A framework for network servers,  Prev: smtplib — SMTP protocol client,  Up: Internet Protocols and Support

5.22.15 ‘uuid’ — UUID objects according to
------------------------------------------

'RFC 9562'

'Source code:' Lib/uuid.py(1)

__________________________________________________________________

This module provides immutable *note UUID: c58. objects (the *note UUID:
c58. class) and *note functions: 4074. for generating UUIDs
corresponding to a specific UUID version as specified in RFC 9562(2)
(which supersedes RFC 4122(3)), for example, *note uuid1(): da3. for
UUID version 1, *note uuid3(): 2e5. for UUID version 3, and so on.  Note
that UUID version 2 is deliberately omitted as it is outside the scope
of the RFC.

If all you want is a unique ID, you should probably call *note uuid1():
da3. or *note uuid4(): 2e7.  Note that *note uuid1(): da3. may
compromise privacy since it creates a UUID containing the computer’s
network address.  *note uuid4(): 2e7. creates a random UUID.

Depending on support from the underlying platform, *note uuid1(): da3.
may or may not return a «safe» UUID. A safe UUID is one which is
generated using synchronization methods that ensure no two processes can
obtain the same UUID. All instances of *note UUID: c58. have an *note
is_safe: da1. attribute which relays any information about the UUID’s
safety, using this enumeration:

 -- Classe: uuid.SafeUUID

     Added in version 3.7.

      -- Attributo: safe

          The UUID was generated by the platform in a
          multiprocessing-safe way.

      -- Attributo: unsafe

          The UUID was not generated in a multiprocessing-safe way.

      -- Attributo: unknown

          The platform does not provide information on whether the UUID
          was generated safely or not.

 -- Classe: uuid.UUID (hex=None, bytes=None, bytes_le=None, fields=None,
          int=None, version=None, *, is_safe=SafeUUID.unknown)

     Create a UUID from either a string of 32 hexadecimal digits, a
     string of 16 bytes in big-endian order as the 'bytes' argument, a
     string of 16 bytes in little-endian order as the 'bytes_le'
     argument, a tuple of six integers (32-bit 'time_low', 16-bit
     'time_mid', 16-bit 'time_hi_version', 8-bit 'clock_seq_hi_variant',
     8-bit 'clock_seq_low', 48-bit 'node') as the 'fields' argument, or
     a single 128-bit integer as the 'int' argument.  When a string of
     hex digits is given, curly braces, hyphens, and a URN prefix are
     all optional.  For example, these expressions all yield the same
     UUID:

          UUID('{12345678-1234-5678-1234-567812345678}')
          UUID('12345678123456781234567812345678')
          UUID('urn:uuid:12345678-1234-5678-1234-567812345678')
          UUID(bytes=b'\x12\x34\x56\x78'*4)
          UUID(bytes_le=b'\x78\x56\x34\x12\x34\x12\x78\x56' +
                        b'\x12\x34\x56\x78\x12\x34\x56\x78')
          UUID(fields=(0x12345678, 0x1234, 0x5678, 0x12, 0x34, 0x567812345678))
          UUID(int=0x12345678123456781234567812345678)

     Exactly one of 'hex', 'bytes', 'bytes_le', 'fields', or 'int' must
     be given.  The 'version' argument is optional; if given, the
     resulting UUID will have its variant and version number set
     according to RFC 9562(4), overriding bits in the given 'hex',
     'bytes', 'bytes_le', 'fields', or 'int'.

     Comparison of UUID objects are made by way of comparing their *note
     UUID.int: 4079. attributes.  Comparison with a non-UUID object
     raises a *note TypeError: 198.

     ‘str(uuid)’ returns a string in the form
     ‘12345678-1234-5678-1234-567812345678’ where the 32 hexadecimal
     digits represent the UUID.

*note UUID: c58. instances have these read-only attributes:

 -- Attributo: UUID.bytes

     The UUID as a 16-byte string (containing the six integer fields in
     big-endian byte order).

 -- Attributo: UUID.bytes_le

     The UUID as a 16-byte string (with 'time_low', 'time_mid', and
     'time_hi_version' in little-endian byte order).

 -- Attributo: UUID.fields

     A tuple of the six integer fields of the UUID, which are also
     available as six individual attributes and two derived attributes:

Field                                                  Meaning
                                                       
                                                       
 -- Attributo: UUID.time_low                           The first 32 bits of the UUID. Only relevant to
                                                       version 1.
                                                       
                                                       
 -- Attributo: UUID.time_mid                           The next 16 bits of the UUID. Only relevant to
                                                       version 1.
                                                       
                                                       
 -- Attributo: UUID.time_hi_version                    The next 16 bits of the UUID. Only relevant to
                                                       version 1.
                                                       
                                                       
 -- Attributo: UUID.clock_seq_hi_variant               The next 8 bits of the UUID. Only relevant to
                                                       versions 1 and 6.
                                                       
                                                       
 -- Attributo: UUID.clock_seq_low                      The next 8 bits of the UUID. Only relevant to
                                                       versions 1 and 6.
                                                       
                                                       
 -- Attributo: UUID.node                               The last 48 bits of the UUID. Only relevant to
                                                       version 1.
                                                       
                                                       
 -- Attributo: UUID.time                               The 60-bit timestamp as a count of 100-nanosecond
                                                       intervals since Gregorian epoch (1582-10-15
                                                       00:00:00) for versions 1 and 6, or the 48-bit
                                                       timestamp in milliseconds since Unix epoch
                                                       (1970-01-01 00:00:00) for version 7.
                                                       
                                                       
 -- Attributo: UUID.clock_seq                          The 14-bit sequence number.  Only relevant to
                                                       versions 1 and 6.
                                                       

 -- Attributo: UUID.hex

     The UUID as a 32-character lowercase hexadecimal string.

 -- Attributo: UUID.int

     The UUID as a 128-bit integer.

 -- Attributo: UUID.urn

     The UUID as a URN as specified in RFC 9562(5).

 -- Attributo: UUID.variant

     The UUID variant, which determines the internal layout of the UUID.
     This will be one of the constants *note RESERVED_NCS: 4087, *note
     RFC_4122: 4088, *note RESERVED_MICROSOFT: 4089, or *note
     RESERVED_FUTURE: 408a.

 -- Attributo: UUID.version

     The UUID version number (1 through 8, meaningful only when the
     variant is *note RFC_4122: 4088.).

     Cambiato nella versione 3.14: Added UUID versions 6, 7 and 8.

 -- Attributo: UUID.is_safe

     An enumeration of *note SafeUUID: 4075. which indicates whether the
     platform generated the UUID in a multiprocessing-safe way.

     Added in version 3.7.

The *note uuid: 116. module defines the following functions:

 -- Funzione: uuid.getnode ()

     Get the hardware address as a 48-bit positive integer.  The first
     time this runs, it may launch a separate program, which could be
     quite slow.  If all attempts to obtain the hardware address fail,
     we choose a random 48-bit number with the multicast bit (least
     significant bit of the first octet) set to 1 as recommended in RFC
     4122(6).  «Hardware address» means the MAC address of a network
     interface.  On a machine with multiple network interfaces,
     universally administered MAC addresses (i.e.  where the second
     least significant bit of the first octet is 'unset') will be
     preferred over locally administered MAC addresses, but with no
     other ordering guarantees.

     Cambiato nella versione 3.7: Universally administered MAC addresses
     are preferred over locally administered MAC addresses, since the
     former are guaranteed to be globally unique, while the latter are
     not.

 -- Funzione: uuid.uuid1 (node=None, clock_seq=None)

     Generate a UUID from a host ID, sequence number, and the current
     time according to RFC 9562, §5.1(7).

     When 'node' is not specified, *note getnode(): da2. is used to
     obtain the hardware address as a 48-bit positive integer.  When a
     sequence number 'clock_seq' is not specified, a pseudo-random
     14-bit positive integer is generated.

     If 'node' or 'clock_seq' exceed their expected bit count, only
     their least significant bits are kept.

 -- Funzione: uuid.uuid3 (namespace, name)

     Generate a UUID based on the MD5 hash of a namespace identifier
     (which is a UUID) and a name (which is a *note bytes: 192. object
     or a string that will be encoded using UTF-8) according to RFC
     9562, §5.3(8).

 -- Funzione: uuid.uuid4 ()

     Generate a random UUID in a cryptographically-secure method
     according to RFC 9562, §5.4(9).

 -- Funzione: uuid.uuid5 (namespace, name)

     Generate a UUID based on the SHA-1 hash of a namespace identifier
     (which is a UUID) and a name (which is a *note bytes: 192. object
     or a string that will be encoded using UTF-8) according to RFC
     9562, §5.5(10).

 -- Funzione: uuid.uuid6 (node=None, clock_seq=None)

     Generate a UUID from a sequence number and the current time
     according to RFC 9562, §5.6(11).

     This is an alternative to *note uuid1(): da3. to improve database
     locality.

     When 'node' is not specified, *note getnode(): da2. is used to
     obtain the hardware address as a 48-bit positive integer.  When a
     sequence number 'clock_seq' is not specified, a pseudo-random
     14-bit positive integer is generated.

     If 'node' or 'clock_seq' exceed their expected bit count, only
     their least significant bits are kept.

     Added in version 3.14.

 -- Funzione: uuid.uuid7 ()

     Generate a time-based UUID according to RFC 9562, §5.7(12).

     For portability across platforms lacking sub-millisecond precision,
     UUIDs produced by this function embed a 48-bit timestamp and use a
     42-bit counter to guarantee monotonicity within a millisecond.

     Added in version 3.14.

 -- Funzione: uuid.uuid8 (a=None, b=None, c=None)

     Generate a pseudo-random UUID according to RFC 9562, §5.8(13).

     When specified, the parameters 'a', 'b' and 'c' are expected to be
     positive integers of 48, 12 and 62 bits respectively.  If they
     exceed their expected bit count, only their least significant bits
     are kept; non-specified arguments are substituted for a
     pseudo-random integer of appropriate size.

     By default, 'a', 'b' and 'c' are not generated by a
     cryptographically secure pseudo-random number generator (CSPRNG).
     Use *note uuid4(): 2e7. when a UUID needs to be used in a
     security-sensitive context.

     Added in version 3.14.

The *note uuid: 116. module defines the following namespace identifiers
for use with *note uuid3(): 2e5. or *note uuid5(): 2e6.

 -- Dati: uuid.NAMESPACE_DNS

     When this namespace is specified, the 'name' string is a fully
     qualified domain name.

 -- Dati: uuid.NAMESPACE_URL

     When this namespace is specified, the 'name' string is a URL.

 -- Dati: uuid.NAMESPACE_OID

     When this namespace is specified, the 'name' string is an ISO OID.

 -- Dati: uuid.NAMESPACE_X500

     When this namespace is specified, the 'name' string is an X.500 DN
     in DER or a text output format.

The *note uuid: 116. module defines the following constants for the
possible values of the *note variant: 4086. attribute:

 -- Dati: uuid.RESERVED_NCS

     Reserved for NCS compatibility.

 -- Dati: uuid.RFC_4122

     Specifies the UUID layout given in RFC 4122(14).  This constant is
     kept for backward compatibility even though RFC 4122(15) has been
     superseded by RFC 9562(16).

 -- Dati: uuid.RESERVED_MICROSOFT

     Reserved for Microsoft compatibility.

 -- Dati: uuid.RESERVED_FUTURE

     Reserved for future definition.

The *note uuid: 116. module defines the special Nil and Max UUID values:

 -- Dati: uuid.NIL

     A special form of UUID that is specified to have all 128 bits set
     to zero according to RFC 9562, §5.9(17).

     Added in version 3.14.

 -- Dati: uuid.MAX

     A special form of UUID that is specified to have all 128 bits set
     to one according to RFC 9562, §5.10(18).

     Added in version 3.14.

Vedi anche
..........

RFC 9562(19) - A Universally Unique IDentifier (UUID) URN Namespace

     This specification defines a Uniform Resource Name namespace for
     UUIDs, the internal format of UUIDs, and methods of generating
     UUIDs.

* Menu:

* Command-Line Usage::
* Example: Example<11>.
* Command-Line Example::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/uuid.py

   (2) https://datatracker.ietf.org/doc/html/rfc9562.html

   (3) https://datatracker.ietf.org/doc/html/rfc4122.html

   (4) https://datatracker.ietf.org/doc/html/rfc9562.html

   (5) https://datatracker.ietf.org/doc/html/rfc9562.html

   (6) https://datatracker.ietf.org/doc/html/rfc4122.html

   (7) https://datatracker.ietf.org/doc/html/rfc9562.html#section-5.1

   (8) https://datatracker.ietf.org/doc/html/rfc9562.html#section-5.3

   (9) https://datatracker.ietf.org/doc/html/rfc9562.html#section-5.4

   (10) https://datatracker.ietf.org/doc/html/rfc9562.html#section-5.5

   (11) https://datatracker.ietf.org/doc/html/rfc9562.html#section-5.6

   (12) https://datatracker.ietf.org/doc/html/rfc9562.html#section-5.7

   (13) https://datatracker.ietf.org/doc/html/rfc9562.html#section-5.8

   (14) https://datatracker.ietf.org/doc/html/rfc4122.html

   (15) https://datatracker.ietf.org/doc/html/rfc4122.html

   (16) https://datatracker.ietf.org/doc/html/rfc9562.html

   (17) https://datatracker.ietf.org/doc/html/rfc9562.html#section-5.9

   (18) https://datatracker.ietf.org/doc/html/rfc9562.html#section-5.10

   (19) https://datatracker.ietf.org/doc/html/rfc9562.html


File: python.info,  Node: Command-Line Usage,  Next: Example<11>,  Up: uuid — UUID objects according to RFC 9562

5.22.15.1 Command-Line Usage
............................

Added in version 3.12.

The *note uuid: 116. module can be executed as a script from the command
line.

     python -m uuid [-h] [-u {uuid1,uuid3,uuid4,uuid5,uuid6,uuid7,uuid8}] [-n NAMESPACE] [-N NAME]

The following options are accepted:

 -- Option: -h, --help

     Show the help message and exit.

 -- Option: -u <uuid>
 -- Option: --uuid <uuid>

     Specify the function name to use to generate the uuid.  By default
     *note uuid4(): 2e7. is used.

     Cambiato nella versione 3.14: Allow generating UUID versions 6, 7
     and 8.

 -- Option: -n <namespace>
 -- Option: --namespace <namespace>

     The namespace is a ‘UUID’, or ‘@ns’ where ‘ns’ is a well-known
     predefined UUID addressed by namespace name.  Such as ‘@dns’,
     ‘@url’, ‘@oid’, and ‘@x500’.  Only required for *note uuid3(): 2e5.
     / *note uuid5(): 2e6. functions.

 -- Option: -N <name>
 -- Option: --name <name>

     The name used as part of generating the uuid.  Only required for
     *note uuid3(): 2e5. / *note uuid5(): 2e6. functions.

 -- Option: -C <num>
 -- Option: --count <num>

     Generate 'num' fresh UUIDs.

     Added in version 3.14.


File: python.info,  Node: Example<11>,  Next: Command-Line Example,  Prev: Command-Line Usage,  Up: uuid — UUID objects according to RFC 9562

5.22.15.2 Example
.................

Here are some examples of typical usage of the *note uuid: 116. module:

     >>> import uuid

     >>> # make a UUID based on the host ID and current time
     >>> uuid.uuid1()
     UUID('a8098c1a-f86e-11da-bd1a-00112444be1e')

     >>> # make a UUID using an MD5 hash of a namespace UUID and a name
     >>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org')
     UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')

     >>> # make a random UUID
     >>> uuid.uuid4()
     UUID('16fd2706-8baf-433b-82eb-8c7fada847da')

     >>> # make a UUID using a SHA-1 hash of a namespace UUID and a name
     >>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org')
     UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d')

     >>> # make a UUID from a string of hex digits (braces and hyphens ignored)
     >>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}')

     >>> # convert a UUID to a string of hex digits in standard form
     >>> str(x)
     '00010203-0405-0607-0809-0a0b0c0d0e0f'

     >>> # get the raw 16 bytes of the UUID
     >>> x.bytes
     b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f'

     >>> # make a UUID from a 16-byte string
     >>> uuid.UUID(bytes=x.bytes)
     UUID('00010203-0405-0607-0809-0a0b0c0d0e0f')

     >>> # get the Nil UUID
     >>> uuid.NIL
     UUID('00000000-0000-0000-0000-000000000000')

     >>> # get the Max UUID
     >>> uuid.MAX
     UUID('ffffffff-ffff-ffff-ffff-ffffffffffff')

     >>> # same as UUIDv1 but with fields reordered to improve DB locality
     >>> uuid.uuid6()
     UUID('1f0799c0-98b9-62db-92c6-a0d365b91053')

     >>> # get UUIDv7 creation (local) time as a timestamp in milliseconds
     >>> u = uuid.uuid7()
     >>> u.time
     1743936859822

     >>> # get UUIDv7 creation (local) time as a datetime object
     >>> import datetime as dt
     >>> dt.datetime.fromtimestamp(u.time / 1000)
     datetime.datetime(...)

     >>> # make a UUID with custom blocks
     >>> uuid.uuid8(0x12345678, 0x9abcdef0, 0x11223344)
     UUID('00001234-5678-8ef0-8000-000011223344')


File: python.info,  Node: Command-Line Example,  Prev: Example<11>,  Up: uuid — UUID objects according to RFC 9562

5.22.15.3 Command-Line Example
..............................

Here are some examples of typical usage of the *note uuid: 116.
command-line interface:

     # generate a random UUID - by default uuid4() is used
     $ python -m uuid

     # generate a UUID using uuid1()
     $ python -m uuid -u uuid1

     # generate a UUID using uuid5
     $ python -m uuid -u uuid5 -n @url -N example.com

     # generate 42 random UUIDs
     $ python -m uuid -C 42


File: python.info,  Node: socketserver — A framework for network servers,  Next: http server — HTTP servers,  Prev: uuid — UUID objects according to RFC 9562,  Up: Internet Protocols and Support

5.22.16 ‘socketserver’ — A framework for network servers
--------------------------------------------------------

'Source code:' Lib/socketserver.py(1)

__________________________________________________________________

The *note socketserver: d2. module simplifies the task of writing
network servers.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

There are four basic concrete server classes:

 -- Classe: socketserver.TCPServer (server_address, RequestHandlerClass,
          bind_and_activate=True)

     This uses the internet TCP protocol, which provides for continuous
     streams of data between the client and server.  If
     'bind_and_activate' is true, the constructor automatically attempts
     to invoke *note server_bind(): 40a1. and *note server_activate():
     40a2.  The other parameters are passed to the *note BaseServer:
     1345. base class.

 -- Classe: socketserver.UDPServer (server_address, RequestHandlerClass,
          bind_and_activate=True)

     This uses datagrams, which are discrete packets of information that
     may arrive out of order or be lost while in transit.  The
     parameters are the same as for *note TCPServer: 1527.

 -- Classe: socketserver.UnixStreamServer (server_address,
          RequestHandlerClass, bind_and_activate=True)
 -- Classe: socketserver.UnixDatagramServer (server_address,
          RequestHandlerClass, bind_and_activate=True)

     These more infrequently used classes are similar to the TCP and UDP
     classes, but use Unix domain sockets; they’re not available on
     non-Unix platforms.  The parameters are the same as for *note
     TCPServer: 1527.

These four classes process requests 'synchronously'; each request must
be completed before the next request can be started.  This isn’t
suitable if each request takes a long time to complete, because it
requires a lot of computation, or because it returns a lot of data which
the client is slow to process.  The solution is to create a separate
process or thread to handle each request; the *note ForkingMixIn: d73.
and *note ThreadingMixIn: d3c. mix-in classes can be used to support
asynchronous behaviour.

Creating a server requires several steps.  First, you must create a
request handler class by subclassing the *note BaseRequestHandler: 40a6.
class and overriding its *note handle(): 40a7. method; this method will
process incoming requests.  Second, you must instantiate one of the
server classes, passing it the server’s address and the request handler
class.  It is recommended to use the server in a *note with: 186.
statement.  Then call the *note handle_request(): 152a. or *note
serve_forever(): 1347. method of the server object to process one or
many requests.  Finally, call *note server_close(): d71. to close the
socket (unless you used a ‘with’ statement).

When inheriting from *note ThreadingMixIn: d3c. for threaded connection
behavior, you should explicitly declare how you want your threads to
behave on an abrupt shutdown.  The *note ThreadingMixIn: d3c. class
defines an attribute 'daemon_threads', which indicates whether or not
the server should wait for thread termination.  You should set the flag
explicitly if you would like threads to behave autonomously; the default
is *note False: d2d, meaning that Python will not exit until all threads
created by *note ThreadingMixIn: d3c. have exited.

Server classes have the same external methods and attributes, no matter
what network protocol they use.

* Menu:

* Server Creation Notes::
* Server Objects: Server Objects<2>.
* Request Handler Objects::
* Examples: Examples<29>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/socketserver.py


File: python.info,  Node: Server Creation Notes,  Next: Server Objects<2>,  Up: socketserver — A framework for network servers

5.22.16.1 Server Creation Notes
...............................

There are five classes in an inheritance diagram, four of which
represent synchronous servers of four types:

     +------------+
     | BaseServer |
     +------------+
           |
           v
     +-----------+        +------------------+
     | TCPServer |------->| UnixStreamServer |
     +-----------+        +------------------+
           |
           v
     +-----------+        +--------------------+
     | UDPServer |------->| UnixDatagramServer |
     +-----------+        +--------------------+

Note that *note UnixDatagramServer: 40a5. derives from *note UDPServer:
40a3, not from *note UnixStreamServer: 40a4. — the only difference
between an IP and a Unix server is the address family.

 -- Classe: socketserver.ForkingMixIn
 -- Classe: socketserver.ThreadingMixIn

     Forking and threading versions of each type of server can be
     created using these mix-in classes.  For instance, *note
     ThreadingUDPServer: 40a9. is created as follows:

          class ThreadingUDPServer(ThreadingMixIn, UDPServer):
              pass

     The mix-in class comes first, since it overrides a method defined
     in *note UDPServer: 40a3.  Setting the various attributes also
     changes the behavior of the underlying server mechanism.

     *note ForkingMixIn: d73. and the Forking classes mentioned below
     are only available on POSIX platforms that support *note fork():
     4b6.

      -- Attributo: block_on_close

          *note ForkingMixIn.server_close: d71. waits until all child
          processes complete, except if *note block_on_close: d72.
          attribute is ‘False’.

          *note ThreadingMixIn.server_close: d71. waits until all
          non-daemon threads complete, except if *note block_on_close:
          d72. attribute is ‘False’.

      -- Attributo: max_children

          Specify how many child processes will exist to handle requests
          at a time for *note ForkingMixIn: d73.  If the limit is
          reached, new requests will wait until one child process has
          finished.

      -- Attributo: daemon_threads

          For *note ThreadingMixIn: d3c. use daemonic threads by setting
          *note ThreadingMixIn.daemon_threads: 40ab. to ‘True’ to not
          wait until threads complete.

     Cambiato nella versione 3.7: *note ForkingMixIn.server_close: d71.
     and *note ThreadingMixIn.server_close: d71. now waits until all
     child processes and non-daemonic threads complete.  Add a new *note
     ForkingMixIn.block_on_close: d72. class attribute to opt-in for the
     pre-3.7 behaviour.

 -- Classe: socketserver.ForkingTCPServer
 -- Classe: socketserver.ForkingUDPServer
 -- Classe: socketserver.ThreadingTCPServer
 -- Classe: socketserver.ThreadingUDPServer
 -- Classe: socketserver.ForkingUnixStreamServer
 -- Classe: socketserver.ForkingUnixDatagramServer
 -- Classe: socketserver.ThreadingUnixStreamServer
 -- Classe: socketserver.ThreadingUnixDatagramServer

     These classes are pre-defined using the mix-in classes.

Added in version 3.12: The ‘ForkingUnixStreamServer’ and
‘ForkingUnixDatagramServer’ classes were added.

To implement a service, you must derive a class from *note
BaseRequestHandler: 40a6. and redefine its *note handle(): 40a7. method.
You can then run various versions of the service by combining one of the
server classes with your request handler class.  The request handler
class must be different for datagram or stream services.  This can be
hidden by using the handler subclasses *note StreamRequestHandler: ed8.
or *note DatagramRequestHandler: 40b3.

Of course, you still have to use your head!  For instance, it makes no
sense to use a forking server if the service contains state in memory
that can be modified by different requests, since the modifications in
the child process would never reach the initial state kept in the parent
process and passed to each child.  In this case, you can use a threading
server, but you will probably have to use locks to protect the integrity
of the shared data.

On the other hand, if you are building an HTTP server where all data is
stored externally (for instance, in the file system), a synchronous
class will essentially render the service «deaf» while one request is
being handled – which may be for a very long time if a client is slow to
receive all the data it has requested.  Here a threading or forking
server is appropriate.

In some cases, it may be appropriate to process part of a request
synchronously, but to finish processing in a forked child depending on
the request data.  This can be implemented by using a synchronous server
and doing an explicit fork in the request handler class *note handle():
40a7. method.

Another approach to handling multiple simultaneous requests in an
environment that supports neither threads nor *note fork(): 4b6. (or
where these are too expensive or inappropriate for the service) is to
maintain an explicit table of partially finished requests and to use
*note selectors: c7. to decide which request to work on next (or whether
to handle a new incoming request).  This is particularly important for
stream services where each client can potentially be connected for a
long time (if threads or subprocesses cannot be used).


File: python.info,  Node: Server Objects<2>,  Next: Request Handler Objects,  Prev: Server Creation Notes,  Up: socketserver — A framework for network servers

5.22.16.2 Server Objects
........................

 -- Classe: socketserver.BaseServer (server_address,
          RequestHandlerClass)

     This is the superclass of all Server objects in the module.  It
     defines the interface, given below, but does not implement most of
     the methods, which is done in subclasses.  The two parameters are
     stored in the respective *note server_address: 40b5. and *note
     RequestHandlerClass: 40b6. attributes.

      -- Metodo: fileno ()

          Return an integer file descriptor for the socket on which the
          server is listening.  This function is most commonly passed to
          *note selectors: c7, to allow monitoring multiple servers in
          the same process.

      -- Metodo: handle_request ()

          Process a single request.  This function calls the following
          methods in order: *note get_request(): 40b8, *note
          verify_request(): 40b9, and *note process_request(): 40ba.  If
          the user-provided *note handle(): 40a7. method of the handler
          class raises an exception, the server’s *note handle_error():
          f3f. method will be called.  If no request is received within
          *note timeout: 1528. seconds, *note handle_timeout(): 1529.
          will be called and *note handle_request(): 152a. will return.

      -- Metodo: serve_forever (poll_interval=0.5)

          Handle requests until an explicit *note shutdown(): 1dfe.
          request.  Poll for shutdown every 'poll_interval' seconds.
          Ignores the *note timeout: 1528. attribute.  It also calls
          *note service_actions(): 1346, which may be used by a subclass
          or mixin to provide actions specific to a given service.  For
          example, the *note ForkingMixIn: d73. class uses *note
          service_actions(): 1346. to clean up zombie child processes.

          Cambiato nella versione 3.3: Added ‘service_actions’ call to
          the ‘serve_forever’ method.

      -- Metodo: service_actions ()

          This is called in the *note serve_forever(): 1347. loop.  This
          method can be overridden by subclasses or mixin classes to
          perform actions specific to a given service, such as cleanup
          actions.

          Added in version 3.3.

      -- Metodo: shutdown ()

          Tell the *note serve_forever(): 1347. loop to stop and wait
          until it does.  *note shutdown(): 1dfe. must be called while
          *note serve_forever(): 1347. is running in a different thread
          otherwise it will deadlock.

      -- Metodo: server_close ()

          Clean up the server.  May be overridden.

      -- Attributo: address_family

          The family of protocols to which the server’s socket belongs.
          Common examples are *note socket.AF_INET: 1b95, *note
          socket.AF_INET6: 1b96, and *note socket.AF_UNIX: 1b98.
          Subclass the TCP or UDP server classes in this module with
          class attribute ‘address_family = AF_INET6’ set if you want
          IPv6 server classes.

      -- Attributo: RequestHandlerClass

          The user-provided request handler class; an instance of this
          class is created for each request.

      -- Attributo: server_address

          The address on which the server is listening.  The format of
          addresses varies depending on the protocol family; see the
          documentation for the *note socket: d1. module for details.
          For internet protocols, this is a tuple containing a string
          giving the address, and an integer port number: ‘('127.0.0.1',
          80)’, for example.

      -- Attributo: socket

          The socket object on which the server will listen for incoming
          requests.

     The server classes support the following class variables:

      -- Attributo: allow_reuse_address

          Whether the server will allow the reuse of an address.  This
          defaults to *note False: d2d, and can be set in subclasses to
          change the policy.

      -- Attributo: request_queue_size

          The size of the request queue.  If it takes a long time to
          process a single request, any requests that arrive while the
          server is busy are placed into a queue, up to *note
          request_queue_size: 40be. requests.  Once the queue is full,
          further requests from clients will get a «Connection denied»
          error.  The default value is usually 5, but this can be
          overridden by subclasses.

      -- Attributo: socket_type

          The type of socket used by the server; *note
          socket.SOCK_STREAM: 14fb. and *note socket.SOCK_DGRAM: 14fa.
          are two common values.

      -- Attributo: timeout

          Timeout duration, measured in seconds, or *note None: 886. if
          no timeout is desired.  If *note handle_request(): 152a.
          receives no incoming requests within the timeout period, the
          *note handle_timeout(): 1529. method is called.

     There are various server methods that can be overridden by
     subclasses of base server classes like *note TCPServer: 1527.;
     these methods aren’t useful to external users of the server object.

      -- Metodo: finish_request (request, client_address)

          Actually processes the request by instantiating *note
          RequestHandlerClass: 40b6. and calling its *note handle():
          40a7. method.

      -- Metodo: get_request ()

          Must accept a request from the socket, and return a 2-tuple
          containing the 'new' socket object to be used to communicate
          with the client, and the client’s address.

      -- Metodo: handle_error (request, client_address)

          This function is called if the *note handle(): 40a7. method of
          a *note RequestHandlerClass: 40b6. instance raises an
          exception.  The default action is to print the traceback to
          standard error and continue handling further requests.

          Cambiato nella versione 3.6: Now only called for exceptions
          derived from the *note Exception: bcf. class.

      -- Metodo: handle_timeout ()

          This function is called when the *note timeout: 1528.
          attribute has been set to a value other than *note None: 886.
          and the timeout period has passed with no requests being
          received.  The default action for forking servers is to
          collect the status of any child processes that have exited,
          while in threading servers this method does nothing.

      -- Metodo: process_request (request, client_address)

          Calls *note finish_request(): 40c0. to create an instance of
          the *note RequestHandlerClass: 40b6.  If desired, this
          function can create a new process or thread to handle the
          request; the *note ForkingMixIn: d73. and *note
          ThreadingMixIn: d3c. classes do this.

      -- Metodo: server_activate ()

          Called by the server’s constructor to activate the server.
          The default behavior for a TCP server just invokes *note
          listen(): 1060. on the server’s socket.  May be overridden.

      -- Metodo: server_bind ()

          Called by the server’s constructor to bind the socket to the
          desired address.  May be overridden.

      -- Metodo: verify_request (request, client_address)

          Must return a Boolean value; if the value is *note True: e09,
          the request will be processed, and if it’s *note False: d2d,
          the request will be denied.  This function can be overridden
          to implement access controls for a server.  The default
          implementation always returns *note True: e09.

     Cambiato nella versione 3.6: Support for the *note context manager:
     1e1. protocol was added.  Exiting the context manager is equivalent
     to calling *note server_close(): d71.


File: python.info,  Node: Request Handler Objects,  Next: Examples<29>,  Prev: Server Objects<2>,  Up: socketserver — A framework for network servers

5.22.16.3 Request Handler Objects
.................................

 -- Classe: socketserver.BaseRequestHandler

     This is the superclass of all request handler objects.  It defines
     the interface, given below.  A concrete request handler subclass
     must define a new *note handle(): 40a7. method, and can override
     any of the other methods.  A new instance of the subclass is
     created for each request.

      -- Metodo: setup ()

          Called before the *note handle(): 40a7. method to perform any
          initialization actions required.  The default implementation
          does nothing.

      -- Metodo: handle ()

          This function must do all the work required to service a
          request.  The default implementation does nothing.  Several
          instance attributes are available to it; the request is
          available as *note request: 40c3.; the client address as *note
          client_address: 40c4.; and the server instance as *note
          server: 40c5, in case it needs access to per-server
          information.

          The type of *note request: 40c3. is different for datagram or
          stream services.  For stream services, *note request: 40c3. is
          a socket object; for datagram services, *note request: 40c3.
          is a pair of string and socket.

      -- Metodo: finish ()

          Called after the *note handle(): 40a7. method to perform any
          clean-up actions required.  The default implementation does
          nothing.  If *note setup(): 40c2. raises an exception, this
          function will not be called.

      -- Attributo: request

          The 'new' *note socket.socket: fa3. object to be used to
          communicate with the client.

      -- Attributo: client_address

          Client address returned by *note BaseServer.get_request():
          40b8.

      -- Attributo: server

          *note BaseServer: 1345. object used for handling the request.

 -- Classe: socketserver.StreamRequestHandler
 -- Classe: socketserver.DatagramRequestHandler

     These *note BaseRequestHandler: 40a6. subclasses override the *note
     setup(): 40c2. and *note finish(): 40c6. methods, and provide *note
     rfile: 40c7. and *note wfile: ed7. attributes.

      -- Attributo: rfile

          A file object from which receives the request is read.
          Support the *note io.BufferedIOBase: 8a4. readable interface.

      -- Attributo: wfile

          A file object to which the reply is written.  Support the
          *note io.BufferedIOBase: 8a4. writable interface

     Cambiato nella versione 3.6: *note wfile: ed7. also supports the
     *note io.BufferedIOBase: 8a4. writable interface.


File: python.info,  Node: Examples<29>,  Prev: Request Handler Objects,  Up: socketserver — A framework for network servers

5.22.16.4 Examples
..................

* Menu:

* socketserver.TCPServer Example: socketserver TCPServer Example.
* socketserver.UDPServer Example: socketserver UDPServer Example.
* Asynchronous Mixins::


File: python.info,  Node: socketserver TCPServer Example,  Next: socketserver UDPServer Example,  Up: Examples<29>

5.22.16.5 ‘socketserver.TCPServer’ Example
..........................................

This is the server side:

     import socketserver

     class MyTCPHandler(socketserver.BaseRequestHandler):
         """
         The request handler class for our server.

         It is instantiated once per connection to the server, and must
         override the handle() method to implement communication to the
         client.
         """

         def handle(self):
             # self.request is the TCP socket connected to the client
             pieces = [b'']
             total = 0
             while b'\n' not in pieces[-1] and total < 10_000:
                 pieces.append(self.request.recv(2000))
                 total += len(pieces[-1])
             self.data = b''.join(pieces)
             print(f"Received from {self.client_address[0]}:")
             print(self.data.decode("utf-8"))
             # just send back the same data, but upper-cased
             self.request.sendall(self.data.upper())
             # after we return, the socket will be closed.

     if __name__ == "__main__":
         HOST, PORT = "localhost", 9999

         # Create the server, binding to localhost on port 9999
         with socketserver.TCPServer((HOST, PORT), MyTCPHandler) as server:
             # Activate the server; this will keep running until you
             # interrupt the program with Ctrl-C
             server.serve_forever()

An alternative request handler class that makes use of streams
(file-like objects that simplify communication by providing the standard
file interface):

     class MyTCPHandler(socketserver.StreamRequestHandler):

         def handle(self):
             # self.rfile is a file-like object created by the handler.
             # We can now use e.g. readline() instead of raw recv() calls.
             # We limit ourselves to 10000 bytes to avoid abuse by the sender.
             self.data = self.rfile.readline(10000).rstrip()
             print(f"{self.client_address[0]} wrote:")
             print(self.data.decode("utf-8"))
             # Likewise, self.wfile is a file-like object used to write back
             # to the client
             self.wfile.write(self.data.upper())

The difference is that the ‘readline()’ call in the second handler will
call ‘recv()’ multiple times until it encounters a newline character,
while the first handler had to use a ‘recv()’ loop to accumulate data
until a newline itself.  If it had just used a single ‘recv()’ without
the loop it would just have returned what has been received so far from
the client.  TCP is stream based: data arrives in the order it was sent,
but there is no correlation between client ‘send()’ or ‘sendall()’ calls
and the number of ‘recv()’ calls on the server required to receive it.

This is the client side:

     import socket
     import sys

     HOST, PORT = "localhost", 9999
     data = " ".join(sys.argv[1:])

     # Create a socket (SOCK_STREAM means a TCP socket)
     with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
         # Connect to server and send data
         sock.connect((HOST, PORT))
         sock.sendall(bytes(data, "utf-8"))
         sock.sendall(b"\n")

         # Receive data from the server and shut down
         received = str(sock.recv(1024), "utf-8")

     print("Sent:    ", data)
     print("Received:", received)

The output of the example should look something like this:

Server:

     $ python TCPServer.py
     127.0.0.1 wrote:
     b'hello world with TCP'
     127.0.0.1 wrote:
     b'python is nice'

Client:

     $ python TCPClient.py hello world with TCP
     Sent:     hello world with TCP
     Received: HELLO WORLD WITH TCP
     $ python TCPClient.py python is nice
     Sent:     python is nice
     Received: PYTHON IS NICE


File: python.info,  Node: socketserver UDPServer Example,  Next: Asynchronous Mixins,  Prev: socketserver TCPServer Example,  Up: Examples<29>

5.22.16.6 ‘socketserver.UDPServer’ Example
..........................................

This is the server side:

     import socketserver

     class MyUDPHandler(socketserver.BaseRequestHandler):
         """
         This class works similar to the TCP handler class, except that
         self.request consists of a pair of data and client socket, and since
         there is no connection the client address must be given explicitly
         when sending data back via sendto().
         """

         def handle(self):
             data = self.request[0].strip()
             socket = self.request[1]
             print(f"{self.client_address[0]} wrote:")
             print(data)
             socket.sendto(data.upper(), self.client_address)

     if __name__ == "__main__":
         HOST, PORT = "localhost", 9999
         with socketserver.UDPServer((HOST, PORT), MyUDPHandler) as server:
             server.serve_forever()

This is the client side:

     import socket
     import sys

     HOST, PORT = "localhost", 9999
     data = " ".join(sys.argv[1:])

     # SOCK_DGRAM is the socket type to use for UDP sockets
     sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

     # As you can see, there is no connect() call; UDP has no connections.
     # Instead, data is directly sent to the recipient via sendto().
     sock.sendto(bytes(data + "\n", "utf-8"), (HOST, PORT))
     received = str(sock.recv(1024), "utf-8")

     print("Sent:    ", data)
     print("Received:", received)

The output of the example should look exactly like for the TCP server
example.


File: python.info,  Node: Asynchronous Mixins,  Prev: socketserver UDPServer Example,  Up: Examples<29>

5.22.16.7 Asynchronous Mixins
.............................

To build asynchronous handlers, use the *note ThreadingMixIn: d3c. and
*note ForkingMixIn: d73. classes.

An example for the *note ThreadingMixIn: d3c. class:

     import socket
     import threading
     import socketserver

     class ThreadedTCPRequestHandler(socketserver.BaseRequestHandler):

         def handle(self):
             data = str(self.request.recv(1024), 'ascii')
             cur_thread = threading.current_thread()
             response = bytes("{}: {}".format(cur_thread.name, data), 'ascii')
             self.request.sendall(response)

     class ThreadedTCPServer(socketserver.ThreadingMixIn, socketserver.TCPServer):
         pass

     def client(ip, port, message):
         with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
             sock.connect((ip, port))
             sock.sendall(bytes(message, 'ascii'))
             response = str(sock.recv(1024), 'ascii')
             print("Received: {}".format(response))

     if __name__ == "__main__":
         # Port 0 means to select an arbitrary unused port
         HOST, PORT = "localhost", 0

         server = ThreadedTCPServer((HOST, PORT), ThreadedTCPRequestHandler)
         with server:
             ip, port = server.server_address

             # Start a thread with the server -- that thread will then start one
             # more thread for each request
             server_thread = threading.Thread(target=server.serve_forever)
             # Exit the server thread when the main thread terminates
             server_thread.daemon = True
             server_thread.start()
             print("Server loop running in thread:", server_thread.name)

             client(ip, port, "Hello World 1")
             client(ip, port, "Hello World 2")
             client(ip, port, "Hello World 3")

             server.shutdown()

The output of the example should look something like this:

     $ python ThreadedTCPServer.py
     Server loop running in thread: Thread-1
     Received: Thread-2: Hello World 1
     Received: Thread-3: Hello World 2
     Received: Thread-4: Hello World 3

The *note ForkingMixIn: d73. class is used in the same way, except that
the server will spawn a new process for each request.  Available only on
POSIX platforms that support *note fork(): 4b6.


File: python.info,  Node: http server — HTTP servers,  Next: http cookies — HTTP state management,  Prev: socketserver — A framework for network servers,  Up: Internet Protocols and Support

5.22.17 ‘http.server’ — HTTP servers
------------------------------------

'Source code:' Lib/http/server.py(1)

__________________________________________________________________

This module defines classes for implementing HTTP servers.

     Avvertimento: *note http.server: 76. is not recommended for
     production.  It only implements *note basic security checks: 40cf.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

One class, *note HTTPServer: 3ecc, is a *note socketserver.TCPServer:
1527. subclass.  It creates and listens at the HTTP socket, dispatching
the requests to a handler.  Code to create and run the server looks like
this:

     def run(server_class=HTTPServer, handler_class=BaseHTTPRequestHandler):
         server_address = ('', 8000)
         httpd = server_class(server_address, handler_class)
         httpd.serve_forever()

 -- Classe: http.server.HTTPServer (server_address, RequestHandlerClass)

     This class builds on the *note TCPServer: 1527. class by storing
     the server address as instance variables named ‘server_name’ and
     ‘server_port’.  The server is accessible by the handler, typically
     through the handler’s ‘server’ instance variable.

 -- Classe: http.server.ThreadingHTTPServer (server_address,
          RequestHandlerClass)

     This class is identical to HTTPServer but uses threads to handle
     requests by using the *note ThreadingMixIn: d3c.  This is useful to
     handle web browsers pre-opening sockets, on which *note HTTPServer:
     3ecc. would wait indefinitely.

     Added in version 3.7.

 -- Classe: http.server.HTTPSServer (server_address,
          RequestHandlerClass, bind_and_activate=True, *, certfile,
          keyfile=None, password=None, alpn_protocols=None)

     Subclass of *note HTTPServer: 3ecc. with a wrapped socket using the
     *note ssl: d5. module.  If the *note ssl: d5. module is not
     available, instantiating a ‘HTTPSServer’ object fails with a *note
     RuntimeError: 244.

     The 'certfile' argument is the path to the SSL certificate chain
     file, and the 'keyfile' is the path to file containing the private
     key.

     A 'password' can be specified for files protected and wrapped with
     PKCS#8, but beware that this could possibly expose hardcoded
     passwords in clear.

     Vedi anche
     ..........

     See *note ssl.SSLContext.load_cert_chain(): 598. for additional
     information on the accepted values for 'certfile', 'keyfile' and
     'password'.

     When specified, the 'alpn_protocols' argument must be a sequence of
     strings specifying the «Application-Layer Protocol Negotiation»
     (ALPN) protocols supported by the server.  ALPN allows the server
     and the client to negotiate the application protocol during the TLS
     handshake.

     By default, it is set to ‘["http/1.1"]’, meaning the server
     supports HTTP/1.1.

     Added in version 3.14.

 -- Classe: http.server.ThreadingHTTPSServer (server_address,
          RequestHandlerClass, bind_and_activate=True, *, certfile,
          keyfile=None, password=None, alpn_protocols=None)

     This class is identical to *note HTTPSServer: 228. but uses threads
     to handle requests by inheriting from *note ThreadingMixIn: d3c.
     This is analogous to *note ThreadingHTTPServer: d3b. only using
     *note HTTPSServer: 228.

     Added in version 3.14.

The *note HTTPServer: 3ecc, *note ThreadingHTTPServer: d3b, *note
HTTPSServer: 228. and *note ThreadingHTTPSServer: 40d0. must be given a
'RequestHandlerClass' on instantiation, of which this module provides
three different variants:

 -- Classe: http.server.BaseHTTPRequestHandler (request, client_address,
          server)

     This class is used to handle the HTTP requests that arrive at the
     server.  By itself, it cannot respond to any actual HTTP requests;
     it must be subclassed to handle each request method (e.g.  GET or
     POST). *note BaseHTTPRequestHandler: 12d3. provides a number of
     class and instance variables, and methods for use by subclasses.

     The handler will parse the request and the headers, then call a
     method specific to the request type.  The method name is
     constructed from the request.  For example, for the request method
     ‘SPAM’, the ‘do_SPAM()’ method will be called with no arguments.
     All of the relevant information is stored in instance variables of
     the handler.  Subclasses should not need to override or extend the
     ‘__init__()’ method.

     *note BaseHTTPRequestHandler: 12d3. has the following instance
     variables:

      -- Attributo: client_address

          Contains a tuple of the form ‘(host, port)’ referring to the
          client’s address.

      -- Attributo: server

          Contains the server instance.

      -- Attributo: close_connection

          Boolean that should be set before *note handle_one_request():
          40d4. returns, indicating if another request may be expected,
          or if the connection should be shut down.

      -- Attributo: requestline

          Contains the string representation of the HTTP request line.
          The terminating CRLF is stripped.  This attribute should be
          set by *note handle_one_request(): 40d4.  If no valid request
          line was processed, it should be set to the empty string.

      -- Attributo: command

          Contains the command (request type).  For example, ‘'GET'’.

      -- Attributo: path

          Contains the request path.  If query component of the URL is
          present, then ‘path’ includes the query.  Using the
          terminology of RFC 3986(2), ‘path’ here includes ‘hier-part’
          and the ‘query’.

      -- Attributo: request_version

          Contains the version string from the request.  For example,
          ‘'HTTP/1.0'’.

      -- Attributo: headers

          Holds an instance of the class specified by the *note
          MessageClass: 40d9. class variable.  This instance parses and
          manages the headers in the HTTP request.  The *note
          parse_headers(): 1e10. function from *note http.client: 73. is
          used to parse the headers and it requires that the HTTP
          request provide a valid RFC 5322(3) style header.

      -- Attributo: rfile

          An *note io.BufferedIOBase: 8a4. input stream, ready to read
          from the start of the optional input data.

      -- Attributo: wfile

          Contains the output stream for writing a response back to the
          client.  Proper adherence to the HTTP protocol must be used
          when writing to this stream in order to achieve successful
          interoperation with HTTP clients.

          Cambiato nella versione 3.6: This is an *note
          io.BufferedIOBase: 8a4. stream.

     *note BaseHTTPRequestHandler: 12d3. has the following attributes:

      -- Attributo: server_version

          Specifies the server software version.  You may want to
          override this.  The format is multiple whitespace-separated
          strings, where each string is of the form name[/version].  For
          example, ‘'BaseHTTP/0.2'’.

      -- Attributo: sys_version

          Contains the Python system version, in a form usable by the
          *note version_string: 40de. method and the *note
          server_version: 40dc. class variable.  For example,
          ‘'Python/1.4'’.

      -- Attributo: error_message_format

          Specifies a format string that should be used by *note
          send_error(): 1151. method for building an error response to
          the client.  The string is filled by default with variables
          from *note responses: 3f96. based on the status code that
          passed to *note send_error(): 1151.

      -- Attributo: error_content_type

          Specifies the Content-Type HTTP header of error responses sent
          to the client.  The default value is ‘'text/html'’.

      -- Attributo: protocol_version

          Specifies the HTTP version to which the server is conformant.
          It is sent in responses to let the client know the server’s
          communication capabilities for future requests.  If set to
          ‘'HTTP/1.1'’, the server will permit HTTP persistent
          connections; however, your server 'must' then include an
          accurate ‘Content-Length’ header (using *note send_header():
          40e1.) in all of its responses to clients.  For backwards
          compatibility, the setting defaults to ‘'HTTP/1.0'’.

      -- Attributo: MessageClass

          Specifies an *note email.message.Message: 581.-like class to
          parse HTTP headers.  Typically, this is not overridden, and it
          defaults to *note http.client.HTTPMessage: 3faf.

      -- Attributo: responses

          This attribute contains a mapping of error code integers to
          two-element tuples containing a short and long message.  For
          example, ‘{code: (shortmessage, longmessage)}’.  The
          'shortmessage' is usually used as the 'message' key in an
          error response, and 'longmessage' as the 'explain' key.  It is
          used by *note send_response_only(): 40e2. and *note
          send_error(): 1151. methods.

     A *note BaseHTTPRequestHandler: 12d3. instance has the following
     methods:

      -- Metodo: handle ()

          Calls *note handle_one_request(): 40d4. once (or, if
          persistent connections are enabled, multiple times) to handle
          incoming HTTP requests.  You should never need to override it;
          instead, implement appropriate ‘do_*()’ methods.

      -- Metodo: handle_one_request ()

          This method will parse and dispatch the request to the
          appropriate ‘do_*()’ method.  You should never need to
          override it.

      -- Metodo: handle_expect_100 ()

          When an HTTP/1.1 conformant server receives an ‘Expect:
          100-continue’ request header it responds back with a ‘100
          Continue’ followed by ‘200 OK’ headers.  This method can be
          overridden to raise an error if the server does not want the
          client to continue.  For e.g.  server can choose to send ‘417
          Expectation Failed’ as a response header and ‘return False’.

          Added in version 3.2.

      -- Metodo: send_error (code, message=None, explain=None)

          Sends and logs a complete error reply to the client.  The
          numeric 'code' specifies the HTTP error code, with 'message'
          as an optional, short, human readable description of the
          error.  The 'explain' argument can be used to provide more
          detailed information about the error; it will be formatted
          using the *note error_message_format: 1152. attribute and
          emitted, after a complete set of headers, as the response
          body.  The *note responses: 3f96. attribute holds the default
          values for 'message' and 'explain' that will be used if no
          value is provided; for unknown codes the default value for
          both is the string ‘???’.  The body will be empty if the
          method is HEAD or the response code is one of the following:
          ‘1XX’, ‘204 No Content’, ‘205 Reset Content’, ‘304 Not
          Modified’.

          Cambiato nella versione 3.4: The error response includes a
          Content-Length header.  Added the 'explain' argument.

      -- Metodo: send_response (code, message=None)

          Adds a response header to the headers buffer and logs the
          accepted request.  The HTTP response line is written to the
          internal buffer, followed by 'Server' and 'Date' headers.  The
          values for these two headers are picked up from the *note
          version_string(): 40de. and *note date_time_string(): 40e6.
          methods, respectively.  If the server does not intend to send
          any other headers using the *note send_header(): 40e1. method,
          then *note send_response(): 40e5. should be followed by an
          *note end_headers(): 12d4. call.

          Cambiato nella versione 3.3: Headers are stored to an internal
          buffer and *note end_headers(): 12d4. needs to be called
          explicitly.

      -- Metodo: send_header (keyword, value)

          Adds the HTTP header to an internal buffer which will be
          written to the output stream when either *note end_headers():
          12d4. or *note flush_headers(): 12d5. is invoked.  'keyword'
          should specify the header keyword, with 'value' specifying its
          value.  Note that, after the send_header calls are done, *note
          end_headers(): 12d4. MUST BE called in order to complete the
          operation.

          Cambiato nella versione 3.2: Headers are stored in an internal
          buffer.

      -- Metodo: send_response_only (code, message=None)

          Sends the response header only, used for the purposes when
          ‘100 Continue’ response is sent by the server to the client.
          The headers not buffered and sent directly the output
          stream.If the 'message' is not specified, the HTTP message
          corresponding the response 'code' is sent.

          Added in version 3.2.

      -- Metodo: end_headers ()

          Adds a blank line (indicating the end of the HTTP headers in
          the response) to the headers buffer and calls *note
          flush_headers(): 12d5.

          Cambiato nella versione 3.2: The buffered headers are written
          to the output stream.

      -- Metodo: flush_headers ()

          Finally send the headers to the output stream and flush the
          internal headers buffer.

          Added in version 3.3.

      -- Metodo: log_request (code='-', size='-')

          Logs an accepted (successful) request.  'code' should specify
          the numeric HTTP code associated with the response.  If a size
          of the response is available, then it should be passed as the
          'size' parameter.

      -- Metodo: log_error (...)

          Logs an error when a request cannot be fulfilled.  By default,
          it passes the message to *note log_message(): 40e9, so it
          takes the same arguments ('format' and additional values).

      -- Metodo: log_message (format, ...)

          Logs an arbitrary message to ‘sys.stderr’.  This is typically
          overridden to create custom error logging mechanisms.  The
          'format' argument is a standard printf-style format string,
          where the additional arguments to *note log_message(): 40e9.
          are applied as inputs to the formatting.  The client ip
          address and current date and time are prefixed to every
          message logged.

      -- Metodo: version_string ()

          Returns the server software’s version string.  This is a
          combination of the *note server_version: 40dc. and *note
          sys_version: 40dd. attributes.

      -- Metodo: date_time_string (timestamp=None)

          Returns the date and time given by 'timestamp' (which must be
          ‘None’ or in the format returned by *note time.time(): 55d.),
          formatted for a message header.  If 'timestamp' is omitted, it
          uses the current date and time.

          The result looks like ‘'Sun, 06 Nov 1994 08:49:37 GMT'’.

      -- Metodo: log_date_time_string ()

          Returns the current date and time, formatted for logging.

      -- Metodo: address_string ()

          Returns the client address.

          Cambiato nella versione 3.3: Previously, a name lookup was
          performed.  To avoid name resolution delays, it now always
          returns the IP address.

 -- Classe: http.server.SimpleHTTPRequestHandler (request,
          client_address, server, directory=None)

     This class serves files from the directory 'directory' and below,
     or the current directory if 'directory' is not provided, directly
     mapping the directory structure to HTTP requests.

     Cambiato nella versione 3.7: Added the 'directory' parameter.

     Cambiato nella versione 3.9: The 'directory' parameter accepts a
     *note path-like object: 5a1.

     A lot of the work, such as parsing the request, is done by the base
     class *note BaseHTTPRequestHandler: 12d3.  This class implements
     the *note do_GET(): 40ec. and *note do_HEAD(): 40ed. functions.

     The following are defined as class-level attributes of *note
     SimpleHTTPRequestHandler: d3a.:

      -- Attributo: server_version

          This will be ‘"SimpleHTTP/" + __version__’, where
          ‘__version__’ is defined at the module level.

      -- Attributo: extensions_map

          A dictionary mapping suffixes into MIME types, contains custom
          overrides for the default system mappings.  The mapping is
          used case-insensitively, and so should contain only
          lower-cased keys.

          Cambiato nella versione 3.9: This dictionary is no longer
          filled with the default system mappings, but only contains
          overrides.

     The *note SimpleHTTPRequestHandler: d3a. class defines the
     following methods:

      -- Metodo: do_HEAD ()

          This method serves the ‘'HEAD'’ request type: it sends the
          headers it would send for the equivalent ‘GET’ request.  See
          the *note do_GET(): 40ec. method for a more complete
          explanation of the possible headers.

      -- Metodo: do_GET ()

          The request is mapped to a local file by interpreting the
          request as a path relative to the current working directory.

          If the request was mapped to a directory, the directory is
          checked for a file named ‘index.html’ or ‘index.htm’ (in that
          order).  If found, the file’s contents are returned; otherwise
          a directory listing is generated by calling the
          ‘list_directory()’ method.  This method uses *note
          os.listdir(): 1302. to scan the directory, and returns a ‘404’
          error response if the *note listdir(): 1302. fails.

          If the request was mapped to a file, it is opened.  Any *note
          OSError: 2c0. exception in opening the requested file is
          mapped to a ‘404’, ‘'File not found'’ error.  If there was an
          ‘'If-Modified-Since'’ header in the request, and the file was
          not modified after this time, a ‘304’, ‘'Not Modified'’
          response is sent.  Otherwise, the content type is guessed by
          calling the ‘guess_type()’ method, which in turn uses the
          'extensions_map' variable, and the file contents are returned.

          A ‘'Content-type:'’ header with the guessed content type is
          output, followed by a ‘'Content-Length:'’ header with the
          file’s size and a ‘'Last-Modified:'’ header with the file’s
          modification time.

          Then follows a blank line signifying the end of the headers,
          and then the contents of the file are output.

          For example usage, see the implementation of the ‘test’
          function in Lib/http/server.py(4).

          Cambiato nella versione 3.7: Support of the
          ‘'If-Modified-Since'’ header.

The *note SimpleHTTPRequestHandler: d3a. class can be used in the
following manner in order to create a very basic webserver serving files
relative to the current directory:

     import http.server
     import socketserver

     PORT = 8000

     Handler = http.server.SimpleHTTPRequestHandler

     with socketserver.TCPServer(("", PORT), Handler) as httpd:
         print("serving at port", PORT)
         httpd.serve_forever()

*note SimpleHTTPRequestHandler: d3a. can also be subclassed to enhance
behavior, such as using different index file names by overriding the
class attribute ‘index_pages’.

 -- Classe: http.server.CGIHTTPRequestHandler (request, client_address,
          server)

     This class is used to serve either files or output of CGI scripts
     from the current directory and below.  Note that mapping HTTP
     hierarchic structure to local directory structure is exactly as in
     *note SimpleHTTPRequestHandler: d3a.

          Nota: CGI scripts run by the *note CGIHTTPRequestHandler: 325.
          class cannot execute redirects (HTTP code 302), because code
          200 (script output follows) is sent prior to execution of the
          CGI script.  This pre-empts the status code.

     The class will however, run the CGI script, instead of serving it
     as a file, if it guesses it to be a CGI script.  Only
     directory-based CGI are used — the other common server
     configuration is to treat special extensions as denoting CGI
     scripts.

     The ‘do_GET()’ and ‘do_HEAD()’ functions are modified to run CGI
     scripts and serve the output, instead of serving files, if the
     request leads to somewhere below the ‘cgi_directories’ path.

     The *note CGIHTTPRequestHandler: 325. defines the following data
     member:

      -- Attributo: cgi_directories

          This defaults to ‘['/cgi-bin', '/htbin']’ and describes
          directories to treat as containing CGI scripts.

     The *note CGIHTTPRequestHandler: 325. defines the following method:

      -- Metodo: do_POST ()

          This method serves the ‘'POST'’ request type, only allowed for
          CGI scripts.  Error 501, «Can only POST to CGI scripts», is
          output when trying to POST to a non-CGI url.

     Note that CGI scripts will be run with UID of user nobody, for
     security reasons.  Problems with the CGI script will be translated
     to error 403.

     Deprecated since version 3.13, will be removed in version 3.15:
     *note CGIHTTPRequestHandler: 325. is being removed in 3.15.  CGI
     has not been considered a good way to do things for well over a
     decade.  This code has been unmaintained for a while now and sees
     very little practical use.  Retaining it could lead to further
     *note security considerations: 40cf.

* Menu:

* Command-line interface: Command-line interface<7>.
* Security considerations: Security considerations<3>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/http/server.py

   (2) https://datatracker.ietf.org/doc/html/rfc3986.html

   (3) https://datatracker.ietf.org/doc/html/rfc5322.html

   (4) https://github.com/python/cpython/tree/3.14/Lib/http/server.py


File: python.info,  Node: Command-line interface<7>,  Next: Security considerations<3>,  Up: http server — HTTP servers

5.22.17.1 Command-line interface
................................

*note http.server: 76. can also be invoked directly using the *note -m:
23c. switch of the interpreter.  The following example illustrates how
to serve files relative to the current directory:

     python -m http.server [OPTIONS] [port]

The following options are accepted:

 -- Option: port

     The server listens to port 8000 by default.  The default can be
     overridden by passing the desired port number as an argument:

          python -m http.server 9000

 -- Option: -b, --bind <address>

     Specifies a specific address to which it should bind.  Both IPv4
     and IPv6 addresses are supported.  By default, the server binds
     itself to all interfaces.  For example, the following command
     causes the server to bind to localhost only:

          python -m http.server --bind 127.0.0.1

     Added in version 3.4.

     Cambiato nella versione 3.8: Support IPv6 in the ‘--bind’ option.

 -- Option: -d, --directory <dir>

     Specifies a directory to which it should serve the files.  By
     default, the server uses the current directory.  For example, the
     following command uses a specific directory:

          python -m http.server --directory /tmp/

     Added in version 3.7.

 -- Option: -p, --protocol <version>

     Specifies the HTTP version to which the server is conformant.  By
     default, the server is conformant to HTTP/1.0.  For example, the
     following command runs an HTTP/1.1 conformant server:

          python -m http.server --protocol HTTP/1.1

     Added in version 3.11.

 -- Option: --cgi

     *note CGIHTTPRequestHandler: 325. can be enabled in the command
     line by passing the ‘--cgi’ option:

          python -m http.server --cgi

     Deprecated since version 3.13, will be removed in version 3.15:
     *note http.server: 76. command line ‘--cgi’ support is being
     removed because *note CGIHTTPRequestHandler: 325. is being removed.

     Avvertimento: *note CGIHTTPRequestHandler: 325. and the ‘--cgi’
     command-line option are not intended for use by untrusted clients
     and may be vulnerable to exploitation.  Always use within a secure
     environment.

 -- Option: --tls-cert

     Specifies a TLS certificate chain for HTTPS connections:

          python -m http.server --tls-cert fullchain.pem

     Added in version 3.14.

 -- Option: --tls-key

     Specifies a private key file for HTTPS connections.

     This option requires ‘--tls-cert’ to be specified.

     Added in version 3.14.

 -- Option: --tls-password-file

     Specifies the password file for password-protected private keys:

          python -m http.server \
                 --tls-cert cert.pem \
                 --tls-key key.pem \
                 --tls-password-file password.txt

     This option requires ‘–tls-cert'’ to be specified.

     Added in version 3.14.


File: python.info,  Node: Security considerations<3>,  Prev: Command-line interface<7>,  Up: http server — HTTP servers

5.22.17.2 Security considerations
.................................

*note SimpleHTTPRequestHandler: d3a. will follow symbolic links when
handling requests, this makes it possible for files outside of the
specified directory to be served.

Earlier versions of Python did not scrub control characters from the log
messages emitted to stderr from ‘python -m http.server’ or the default
*note BaseHTTPRequestHandler: 12d3. ‘.log_message’ implementation.  This
could allow remote clients connecting to your server to send nefarious
control codes to your terminal.

Cambiato nella versione 3.12: Control characters are scrubbed in stderr
logs.


File: python.info,  Node: http cookies — HTTP state management,  Next: http cookiejar — Cookie handling for HTTP clients,  Prev: http server — HTTP servers,  Up: Internet Protocols and Support

5.22.18 ‘http.cookies’ — HTTP state management
----------------------------------------------

'Source code:' Lib/http/cookies.py(1)

__________________________________________________________________

The *note http.cookies: 75. module defines classes for abstracting the
concept of cookies, an HTTP state management mechanism.  It supports
both simple string-only cookies, and provides an abstraction for having
any serializable data-type as cookie value.

The module formerly strictly applied the parsing rules described in the
RFC 2109(2) and RFC 2068(3) specifications.  It has since been
discovered that MSIE 3.0x didn’t follow the character rules outlined in
those specs; many current-day browsers and servers have also relaxed
parsing rules when it comes to cookie handling.  As a result, this
module now uses parsing rules that are a bit less strict than they once
were.

The character set, *note string.ascii_letters: 14cb, *note
string.digits: 2705. and ‘!#$%&'*+-.^_`|~:’ denote the set of valid
characters allowed by this module in a cookie name (as *note key: dfd.).

Cambiato nella versione 3.3: Allowed “:” as a valid cookie name
character.

     Nota: On encountering an invalid cookie, *note CookieError: 40fe.
     is raised, so if your cookie data comes from a browser you should
     always prepare for invalid data and catch *note CookieError: 40fe.
     on parsing.

 -- Eccezione: http.cookies.CookieError

     Exception failing because of RFC 2109(4) invalidity: incorrect
     attributes, incorrect ‘Set-Cookie’ header, etc.

 -- Classe: http.cookies.BaseCookie ([input])

     This class is a dictionary-like object whose keys are strings and
     whose values are *note Morsel: e00. instances.  Note that upon
     setting a key to a value, the value is first converted to a *note
     Morsel: e00. containing the key and the value.

     If 'input' is given, it is passed to the *note load(): 4100.
     method.

 -- Classe: http.cookies.SimpleCookie ([input])

     This class derives from *note BaseCookie: 40ff. and overrides *note
     value_decode(): 4101. and *note value_encode(): 4102.
     ‘SimpleCookie’ supports strings as cookie values.  When setting the
     value, ‘SimpleCookie’ calls the builtin *note str(): 169. to
     convert the value to a string.  Values received from HTTP are kept
     as strings.

Vedi anche
..........

Module *note http.cookiejar: 74.

     HTTP cookie handling for web 'clients'.  The *note http.cookiejar:
     74. and *note http.cookies: 75. modules do not depend on each
     other.

RFC 2109(5) - HTTP State Management Mechanism

     This is the state management specification implemented by this
     module.

* Menu:

* Cookie Objects::
* Morsel Objects::
* Example: Example<12>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/http/cookies.py

   (2) https://datatracker.ietf.org/doc/html/rfc2109.html

   (3) https://datatracker.ietf.org/doc/html/rfc2068.html

   (4) https://datatracker.ietf.org/doc/html/rfc2109.html

   (5) https://datatracker.ietf.org/doc/html/rfc2109.html


File: python.info,  Node: Cookie Objects,  Next: Morsel Objects,  Up: http cookies — HTTP state management

5.22.18.1 Cookie Objects
........................

 -- Metodo: BaseCookie.value_decode (val)

     Return a tuple ‘(real_value, coded_value)’ from a string
     representation.  ‘real_value’ can be any type.  This method does no
     decoding in *note BaseCookie: 40ff. — it exists so it can be
     overridden.

 -- Metodo: BaseCookie.value_encode (val)

     Return a tuple ‘(real_value, coded_value)’.  'val' can be any type,
     but ‘coded_value’ will always be converted to a string.  This
     method does no encoding in *note BaseCookie: 40ff. — it exists so
     it can be overridden.

     In general, it should be the case that *note value_encode(): 4102.
     and *note value_decode(): 4101. are inverses on the range of
     'value_decode'.

 -- Metodo: BaseCookie.output (attrs=None, header='Set-Cookie:',
          sep='\r\n')

     Return a string representation suitable to be sent as HTTP headers.
     'attrs' and 'header' are sent to each *note Morsel: e00.’s *note
     output(): 4106. method.  'sep' is used to join the headers
     together, and is by default the combination ‘'\r\n'’ (CRLF).

 -- Metodo: BaseCookie.js_output (attrs=None)

     Return an embeddable JavaScript snippet, which, if run on a browser
     which supports JavaScript, will act the same as if the HTTP headers
     was sent.

     The meaning for 'attrs' is the same as in *note output(): 4105.

 -- Metodo: BaseCookie.load (rawdata)

     If 'rawdata' is a string, parse it as an ‘HTTP_COOKIE’ and add the
     values found there as *note Morsel: e00.s.  If it is a dictionary,
     it is equivalent to:

          for k, v in rawdata.items():
              cookie[k] = v


File: python.info,  Node: Morsel Objects,  Next: Example<12>,  Prev: Cookie Objects,  Up: http cookies — HTTP state management

5.22.18.2 Morsel Objects
........................

 -- Classe: http.cookies.Morsel

     Abstract a key/value pair, which has some RFC 2109(1) attributes.

     Morsels are dictionary-like objects, whose set of keys is constant
     — the valid RFC 2109(2) attributes, which are:

           -- Attributo: expires
           -- Attributo: path
           -- Attributo: comment
           -- Attributo: domain

           -- Attributo: max-age
           -- Attributo: secure
           -- Attributo: version
           -- Attributo: httponly
           -- Attributo: samesite
           -- Attributo: partitioned

     The attribute *note httponly: 15d7. specifies that the cookie is
     only transferred in HTTP requests, and is not accessible through
     JavaScript.  This is intended to mitigate some forms of cross-site
     scripting.

     The attribute *note samesite: 4110. controls when the browser sends
     the cookie with cross-site requests.  This helps to mitigate CSRF
     attacks.  Valid values are «Strict» (only sent with same-site
     requests), «Lax» (sent with same-site requests and top-level
     navigations), and «None» (sent with same-site and cross-site
     requests).  When using «None», the «secure» attribute must also be
     set, as required by modern browsers.

     The attribute *note partitioned: 4111. indicates to user agents
     that these cross-site cookies 'should' only be available in the
     same top-level context that the cookie was first set in.  For this
     to be accepted by the user agent, you 'must' also set ‘Secure’.

     In addition, it is recommended to use the ‘__Host’ prefix when
     setting partitioned cookies to make them bound to the hostname and
     not the registrable domain.  Read CHIPS (Cookies Having Independent
     Partitioned State)(3) for full details and examples.

     The keys are case-insensitive and their default value is ‘''’.

     Cambiato nella versione 3.5: ‘__eq__()’ now takes *note key: dfd.
     and *note value: dfe. into account.

     Cambiato nella versione 3.7: Attributes *note key: dfd, *note
     value: dfe. and *note coded_value: dff. are read-only.  Use *note
     set(): e01. for setting them.

     Cambiato nella versione 3.8: Added support for the *note samesite:
     4110. attribute.

     Cambiato nella versione 3.14: Added support for the *note
     partitioned: 4111. attribute.

 -- Attributo: Morsel.value

     The value of the cookie.

 -- Attributo: Morsel.coded_value

     The encoded value of the cookie — this is what should be sent.

 -- Attributo: Morsel.key

     The name of the cookie.

 -- Metodo: Morsel.set (key, value, coded_value)

     Set the 'key', 'value' and 'coded_value' attributes.

 -- Metodo: Morsel.isReservedKey (K)

     Whether 'K' is a member of the set of keys of a *note Morsel: e00.

 -- Metodo: Morsel.output (attrs=None, header='Set-Cookie:')

     Return a string representation of the Morsel, suitable to be sent
     as an HTTP header.  By default, all the attributes are included,
     unless 'attrs' is given, in which case it should be a list of
     attributes to use.  'header' is by default ‘"Set-Cookie:"’.

 -- Metodo: Morsel.js_output (attrs=None)

     Return an embeddable JavaScript snippet, which, if run on a browser
     which supports JavaScript, will act the same as if the HTTP header
     was sent.

     The meaning for 'attrs' is the same as in *note output(): 4106.

 -- Metodo: Morsel.OutputString (attrs=None)

     Return a string representing the Morsel, without any surrounding
     HTTP or JavaScript.

     The meaning for 'attrs' is the same as in *note output(): 4106.

 -- Metodo: Morsel.update (values)

     Update the values in the Morsel dictionary with the values in the
     dictionary 'values'.  Raise an error if any of the keys in the
     'values' dict is not a valid RFC 2109(4) attribute.

     Cambiato nella versione 3.5: an error is raised for invalid keys.

 -- Metodo: Morsel.copy (value)

     Return a shallow copy of the Morsel object.

     Cambiato nella versione 3.5: return a Morsel object instead of a
     dict.

 -- Metodo: Morsel.setdefault (key, value=None)

     Raise an error if key is not a valid RFC 2109(5) attribute,
     otherwise behave the same as *note dict.setdefault(): 127b.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2109.html

   (2) https://datatracker.ietf.org/doc/html/rfc2109.html

   (3) https://github.com/privacycg/CHIPS/blob/main/README.md

   (4) https://datatracker.ietf.org/doc/html/rfc2109.html

   (5) https://datatracker.ietf.org/doc/html/rfc2109.html


File: python.info,  Node: Example<12>,  Prev: Morsel Objects,  Up: http cookies — HTTP state management

5.22.18.3 Example
.................

The following example demonstrates how to use the *note http.cookies:
75. module.

     >>> from http import cookies
     >>> C = cookies.SimpleCookie()
     >>> C["fig"] = "newton"
     >>> C["sugar"] = "wafer"
     >>> print(C) # generate HTTP headers
     Set-Cookie: fig=newton
     Set-Cookie: sugar=wafer
     >>> print(C.output()) # same thing
     Set-Cookie: fig=newton
     Set-Cookie: sugar=wafer
     >>> C = cookies.SimpleCookie()
     >>> C["rocky"] = "road"
     >>> C["rocky"]["path"] = "/cookie"
     >>> print(C.output(header="Cookie:"))
     Cookie: rocky=road; Path=/cookie
     >>> print(C.output(attrs=[], header="Cookie:"))
     Cookie: rocky=road
     >>> C = cookies.SimpleCookie()
     >>> C.load("chips=ahoy; vienna=finger") # load from a string (HTTP header)
     >>> print(C)
     Set-Cookie: chips=ahoy
     Set-Cookie: vienna=finger
     >>> C = cookies.SimpleCookie()
     >>> C.load('keebler="E=everybody; L=\\"Loves\\"; fudge=;";')
     >>> print(C)
     Set-Cookie: keebler="E=everybody; L=\"Loves\"; fudge=;"
     >>> C = cookies.SimpleCookie()
     >>> C["oreo"] = "doublestuff"
     >>> C["oreo"]["path"] = "/"
     >>> print(C)
     Set-Cookie: oreo=doublestuff; Path=/
     >>> C = cookies.SimpleCookie()
     >>> C["twix"] = "none for you"
     >>> C["twix"].value
     'none for you'
     >>> C = cookies.SimpleCookie()
     >>> C["number"] = 7 # equivalent to C["number"] = str(7)
     >>> C["string"] = "seven"
     >>> C["number"].value
     '7'
     >>> C["string"].value
     'seven'
     >>> print(C)
     Set-Cookie: number=7
     Set-Cookie: string=seven


File: python.info,  Node: http cookiejar — Cookie handling for HTTP clients,  Next: xmlrpc — XMLRPC server and client modules,  Prev: http cookies — HTTP state management,  Up: Internet Protocols and Support

5.22.19 ‘http.cookiejar’ — Cookie handling for HTTP clients
-----------------------------------------------------------

'Source code:' Lib/http/cookiejar.py(1)

__________________________________________________________________

The *note http.cookiejar: 74. module defines classes for automatic
handling of HTTP cookies.  It is useful for accessing websites that
require small pieces of data – 'cookies' – to be set on the client
machine by an HTTP response from a web server, and then returned to the
server in later HTTP requests.

Both the regular Netscape cookie protocol and the protocol defined by
RFC 2965(2) are handled.  RFC 2965 handling is switched off by default.
RFC 2109(3) cookies are parsed as Netscape cookies and subsequently
treated either as Netscape or RFC 2965 cookies according to the “policy”
in effect.  Note that the great majority of cookies on the internet are
Netscape cookies.  *note http.cookiejar: 74. attempts to follow the
de-facto Netscape cookie protocol (which differs substantially from that
set out in the original Netscape specification), including taking note
of the ‘max-age’ and ‘port’ cookie-attributes introduced with RFC 2965.

     Nota: The various named parameters found in ‘Set-Cookie’ and
     ‘Set-Cookie2’ headers (eg.  ‘domain’ and ‘expires’) are
     conventionally referred to as 'attributes'.  To distinguish them
     from Python attributes, the documentation for this module uses the
     term 'cookie-attribute' instead.

The module defines the following exception:

 -- Eccezione: http.cookiejar.LoadError

     Instances of *note FileCookieJar: 411c. raise this exception on
     failure to load cookies from a file.  *note LoadError: 411b. is a
     subclass of *note OSError: 2c0.

     Cambiato nella versione 3.3: *note LoadError: 411b. used to be a
     subtype of *note IOError: 1255, which is now an alias of *note
     OSError: 2c0.

The following classes are provided:

 -- Classe: http.cookiejar.CookieJar (policy=None)

     'policy' is an object implementing the *note CookiePolicy: 411d.
     interface.

     The *note CookieJar: 3f3a. class stores HTTP cookies.  It extracts
     cookies from HTTP requests, and returns them in HTTP responses.
     *note CookieJar: 3f3a. instances automatically expire contained
     cookies when necessary.  Subclasses are also responsible for
     storing and retrieving cookies from a file or database.

 -- Classe: http.cookiejar.FileCookieJar (filename=None, delayload=None,
          policy=None)

     'policy' is an object implementing the *note CookiePolicy: 411d.
     interface.  For the other arguments, see the documentation for the
     corresponding attributes.

     A *note CookieJar: 3f3a. which can load cookies from, and perhaps
     save cookies to, a file on disk.  Cookies are 'NOT' loaded from the
     named file until either the *note load(): 411e. or *note revert():
     411f. method is called.  Subclasses of this class are documented in
     section *note FileCookieJar subclasses and co-operation with web
     browsers: 4120.

     This should not be initialized directly – use its subclasses below
     instead.

     Cambiato nella versione 3.8: The filename parameter supports a
     *note path-like object: 5a1.

 -- Classe: http.cookiejar.CookiePolicy

     This class is responsible for deciding whether each cookie should
     be accepted from / returned to the server.

 -- Classe: http.cookiejar.DefaultCookiePolicy (blocked_domains=None,
          allowed_domains=None, netscape=True, rfc2965=False,
          rfc2109_as_netscape=None, hide_cookie2=False,
          strict_domain=False, strict_rfc2965_unverifiable=True,
          strict_ns_unverifiable=False,
          strict_ns_domain=DefaultCookiePolicy.DomainLiberal,
          strict_ns_set_initial_dollar=False, strict_ns_set_path=False,
          secure_protocols=('https', 'wss'))

     Constructor arguments should be passed as keyword arguments only.
     'blocked_domains' is a sequence of domain names that we never
     accept cookies from, nor return cookies to.  'allowed_domains' if
     not *note None: 886, this is a sequence of the only domains for
     which we accept and return cookies.  'secure_protocols' is a
     sequence of protocols for which secure cookies can be added to.  By
     default 'https' and 'wss' (secure websocket) are considered secure
     protocols.  For all other arguments, see the documentation for
     *note CookiePolicy: 411d. and *note DefaultCookiePolicy: 1ddc.
     objects.

     *note DefaultCookiePolicy: 1ddc. implements the standard accept /
     reject rules for Netscape and RFC 2965(4) cookies.  By default, RFC
     2109(5) cookies (ie.  cookies received in a ‘Set-Cookie’ header
     with a version cookie-attribute of 1) are treated according to the
     RFC 2965 rules.  However, if RFC 2965 handling is turned off or
     *note rfc2109_as_netscape: 4121. is ‘True’, RFC 2109 cookies are
     “downgraded” by the *note CookieJar: 3f3a. instance to Netscape
     cookies, by setting the ‘version’ attribute of the *note Cookie:
     4122. instance to 0.  *note DefaultCookiePolicy: 1ddc. also
     provides some parameters to allow some fine-tuning of policy.

 -- Classe: http.cookiejar.Cookie

     This class represents Netscape, RFC 2109(6) and RFC 2965(7)
     cookies.  It is not expected that users of *note http.cookiejar:
     74. construct their own *note Cookie: 4122. instances.  Instead, if
     necessary, call ‘make_cookies()’ on a *note CookieJar: 3f3a.
     instance.

Vedi anche
..........

Module *note urllib.request: 111.

     URL opening with automatic cookie handling.

Module *note http.cookies: 75.

     HTTP cookie classes, principally useful for server-side code.  The
     *note http.cookiejar: 74. and *note http.cookies: 75. modules do
     not depend on each other.

‘https://curl.se/rfc/cookie_spec.html’

     The specification of the original Netscape cookie protocol.  Though
     this is still the dominant protocol, the “Netscape cookie protocol”
     implemented by all the major browsers (and *note http.cookiejar:
     74.) only bears a passing resemblance to the one sketched out in
     ‘cookie_spec.html’.

RFC 2109(8) - HTTP State Management Mechanism

     Obsoleted by RFC 2965(9).  Uses ‘Set-Cookie’ with version=1.

RFC 2965(10) - HTTP State Management Mechanism

     The Netscape protocol with the bugs fixed.  Uses ‘Set-Cookie2’ in
     place of ‘Set-Cookie’.  Not widely used.

‘https://kristol.org/cookie/errata.html’

     Unfinished errata to RFC 2965(11).

RFC 2964(12) - Use of HTTP State Management

* Menu:

* CookieJar and FileCookieJar Objects::
* FileCookieJar subclasses and co-operation with web browsers::
* CookiePolicy Objects::
* DefaultCookiePolicy Objects::
* Cookie Objects: Cookie Objects<2>.
* Examples: Examples<30>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/http/cookiejar.py

   (2) https://datatracker.ietf.org/doc/html/rfc2965.html

   (3) https://datatracker.ietf.org/doc/html/rfc2109.html

   (4) https://datatracker.ietf.org/doc/html/rfc2965.html

   (5) https://datatracker.ietf.org/doc/html/rfc2109.html

   (6) https://datatracker.ietf.org/doc/html/rfc2109.html

   (7) https://datatracker.ietf.org/doc/html/rfc2965.html

   (8) https://datatracker.ietf.org/doc/html/rfc2109.html

   (9) https://datatracker.ietf.org/doc/html/rfc2965.html

   (10) https://datatracker.ietf.org/doc/html/rfc2965.html

   (11) https://datatracker.ietf.org/doc/html/rfc2965.html

   (12) https://datatracker.ietf.org/doc/html/rfc2964.html


File: python.info,  Node: CookieJar and FileCookieJar Objects,  Next: FileCookieJar subclasses and co-operation with web browsers,  Up: http cookiejar — Cookie handling for HTTP clients

5.22.19.1 CookieJar and FileCookieJar Objects
.............................................

*note CookieJar: 3f3a. objects support the *note iterator: 4c9. protocol
for iterating over contained *note Cookie: 4122. objects.

*note CookieJar: 3f3a. has the following methods:

 -- Metodo: CookieJar.add_cookie_header (request)

     Add correct ‘Cookie’ header to 'request'.

     If policy allows (ie.  the ‘rfc2965’ and ‘hide_cookie2’ attributes
     of the *note CookieJar: 3f3a.’s *note CookiePolicy: 411d. instance
     are true and false respectively), the ‘Cookie2’ header is also
     added when appropriate.

     The 'request' object (usually a *note urllib.request.Request: 11da.
     instance) must support the methods ‘get_full_url()’,
     ‘has_header()’, ‘get_header()’, ‘header_items()’,
     ‘add_unredirected_header()’ and the attributes ‘host’, ‘type’,
     ‘unverifiable’ and ‘origin_req_host’ as documented by *note
     urllib.request: 111.

     Cambiato nella versione 3.3: 'request' object needs
     ‘origin_req_host’ attribute.  Dependency on a deprecated method
     ‘get_origin_req_host()’ has been removed.

 -- Metodo: CookieJar.extract_cookies (response, request)

     Extract cookies from HTTP 'response' and store them in the *note
     CookieJar: 3f3a, where allowed by policy.

     The *note CookieJar: 3f3a. will look for allowable ‘Set-Cookie’ and
     ‘Set-Cookie2’ headers in the 'response' argument, and store cookies
     as appropriate (subject to the *note CookiePolicy.set_ok(): 4127.
     method’s approval).

     The 'response' object (usually the result of a call to *note
     urllib.request.urlopen(): 307, or similar) should support an
     ‘info()’ method, which returns an *note email.message.Message: 581.
     instance.

     The 'request' object (usually a *note urllib.request.Request: 11da.
     instance) must support the method ‘get_full_url()’ and the
     attributes ‘host’, ‘unverifiable’ and ‘origin_req_host’, as
     documented by *note urllib.request: 111.  The request is used to
     set default values for cookie-attributes as well as for checking
     that the cookie is allowed to be set.

     Cambiato nella versione 3.3: 'request' object needs
     ‘origin_req_host’ attribute.  Dependency on a deprecated method
     ‘get_origin_req_host()’ has been removed.

 -- Metodo: CookieJar.set_policy (policy)

     Set the *note CookiePolicy: 411d. instance to be used.

 -- Metodo: CookieJar.make_cookies (response, request)

     Return sequence of *note Cookie: 4122. objects extracted from
     'response' object.

     See the documentation for *note extract_cookies(): 4126. for the
     interfaces required of the 'response' and 'request' arguments.

 -- Metodo: CookieJar.set_cookie_if_ok (cookie, request)

     Set a *note Cookie: 4122. if policy says it’s OK to do so.

 -- Metodo: CookieJar.set_cookie (cookie)

     Set a *note Cookie: 4122, without checking with policy to see
     whether or not it should be set.

 -- Metodo: CookieJar.clear ([domain[, path[, name]]])

     Clear some cookies.

     If invoked without arguments, clear all cookies.  If given a single
     argument, only cookies belonging to that 'domain' will be removed.
     If given two arguments, cookies belonging to the specified 'domain'
     and URL 'path' are removed.  If given three arguments, then the
     cookie with the specified 'domain', 'path' and 'name' is removed.

     Raises *note KeyError: 5e7. if no matching cookie exists.

 -- Metodo: CookieJar.clear_session_cookies ()

     Discard all session cookies.

     Discards all contained cookies that have a true ‘discard’ attribute
     (usually because they had either no ‘max-age’ or ‘expires’
     cookie-attribute, or an explicit ‘discard’ cookie-attribute).  For
     interactive browsers, the end of a session usually corresponds to
     closing the browser window.

     Note that the ‘save()’ method won’t save session cookies anyway,
     unless you ask otherwise by passing a true 'ignore_discard'
     argument.

*note FileCookieJar: 411c. implements the following additional methods:

 -- Metodo: FileCookieJar.save (filename=None, ignore_discard=False,
          ignore_expires=False)

     Save cookies to a file.

     This base class raises *note NotImplementedError: 36b.  Subclasses
     may leave this method unimplemented.

     'filename' is the name of file in which to save cookies.  If
     'filename' is not specified, ‘self.filename’ is used (whose default
     is the value passed to the constructor, if any); if ‘self.filename’
     is *note None: 886, *note ValueError: 2ec. is raised.

     'ignore_discard': save even cookies set to be discarded.
     'ignore_expires': save even cookies that have expired

     The file is overwritten if it already exists, thus wiping all the
     cookies it contains.  Saved cookies can be restored later using the
     *note load(): 411e. or *note revert(): 411f. methods.

 -- Metodo: FileCookieJar.load (filename=None, ignore_discard=False,
          ignore_expires=False)

     Load cookies from a file.

     Old cookies are kept unless overwritten by newly loaded ones.

     Arguments are as for *note save(): 412e.

     The named file must be in the format understood by the class, or
     *note LoadError: 411b. will be raised.  Also, *note OSError: 2c0.
     may be raised, for example if the file does not exist.

     Cambiato nella versione 3.3: *note IOError: 1255. used to be
     raised, it is now an alias of *note OSError: 2c0.

 -- Metodo: FileCookieJar.revert (filename=None, ignore_discard=False,
          ignore_expires=False)

     Clear all cookies and reload cookies from a saved file.

     *note revert(): 411f. can raise the same exceptions as *note
     load(): 411e.  If there is a failure, the object’s state will not
     be altered.

*note FileCookieJar: 411c. instances have the following public
attributes:

 -- Attributo: FileCookieJar.filename

     Filename of default file in which to keep cookies.  This attribute
     may be assigned to.

 -- Attributo: FileCookieJar.delayload

     If true, load cookies lazily from disk.  This attribute should not
     be assigned to.  This is only a hint, since this only affects
     performance, not behaviour (unless the cookies on disk are
     changing).  A *note CookieJar: 3f3a. object may ignore it.  None of
     the *note FileCookieJar: 411c. classes included in the standard
     library lazily loads cookies.


File: python.info,  Node: FileCookieJar subclasses and co-operation with web browsers,  Next: CookiePolicy Objects,  Prev: CookieJar and FileCookieJar Objects,  Up: http cookiejar — Cookie handling for HTTP clients

5.22.19.2 FileCookieJar subclasses and co-operation with web browsers
.....................................................................

The following *note CookieJar: 3f3a. subclasses are provided for reading
and writing.

 -- Classe: http.cookiejar.MozillaCookieJar (filename=None,
          delayload=None, policy=None)

     A *note FileCookieJar: 411c. that can load from and save cookies to
     disk in the Mozilla ‘cookies.txt’ file format (which is also used
     by curl and the Lynx and Netscape browsers).

          Nota: This loses information about RFC 2965(1) cookies, and
          also about newer or non-standard cookie-attributes such as
          ‘port’.

          Avvertimento: Back up your cookies before saving if you have
          cookies whose loss / corruption would be inconvenient (there
          are some subtleties which may lead to slight changes in the
          file over a load / save round-trip).

     Also note that cookies saved while Mozilla is running will get
     clobbered by Mozilla.

 -- Classe: http.cookiejar.LWPCookieJar (filename=None, delayload=None,
          policy=None)

     A *note FileCookieJar: 411c. that can load from and save cookies to
     disk in format compatible with the libwww-perl library’s
     ‘Set-Cookie3’ file format.  This is convenient if you want to store
     cookies in a human-readable file.

     Cambiato nella versione 3.8: The filename parameter supports a
     *note path-like object: 5a1.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2965.html


File: python.info,  Node: CookiePolicy Objects,  Next: DefaultCookiePolicy Objects,  Prev: FileCookieJar subclasses and co-operation with web browsers,  Up: http cookiejar — Cookie handling for HTTP clients

5.22.19.3 CookiePolicy Objects
..............................

Objects implementing the *note CookiePolicy: 411d. interface have the
following methods:

 -- Metodo: CookiePolicy.set_ok (cookie, request)

     Return boolean value indicating whether cookie should be accepted
     from server.

     'cookie' is a *note Cookie: 4122. instance.  'request' is an object
     implementing the interface defined by the documentation for *note
     CookieJar.extract_cookies(): 4126.

 -- Metodo: CookiePolicy.return_ok (cookie, request)

     Return boolean value indicating whether cookie should be returned
     to server.

     'cookie' is a *note Cookie: 4122. instance.  'request' is an object
     implementing the interface defined by the documentation for *note
     CookieJar.add_cookie_header(): 4125.

 -- Metodo: CookiePolicy.domain_return_ok (domain, request)

     Return ‘False’ if cookies should not be returned, given cookie
     domain.

     This method is an optimization.  It removes the need for checking
     every cookie with a particular domain (which might involve reading
     many files).  Returning true from *note domain_return_ok(): 4137.
     and *note path_return_ok(): 4138. leaves all the work to *note
     return_ok(): 4136.

     If *note domain_return_ok(): 4137. returns true for the cookie
     domain, *note path_return_ok(): 4138. is called for the cookie
     path.  Otherwise, *note path_return_ok(): 4138. and *note
     return_ok(): 4136. are never called for that cookie domain.  If
     *note path_return_ok(): 4138. returns true, *note return_ok():
     4136. is called with the *note Cookie: 4122. object itself for a
     full check.  Otherwise, *note return_ok(): 4136. is never called
     for that cookie path.

     Note that *note domain_return_ok(): 4137. is called for every
     'cookie' domain, not just for the 'request' domain.  For example,
     the function might be called with both ‘".example.com"’ and
     ‘"www.example.com"’ if the request domain is ‘"www.example.com"’.
     The same goes for *note path_return_ok(): 4138.

     The 'request' argument is as documented for *note return_ok():
     4136.

 -- Metodo: CookiePolicy.path_return_ok (path, request)

     Return ‘False’ if cookies should not be returned, given cookie
     path.

     See the documentation for *note domain_return_ok(): 4137.

In addition to implementing the methods above, implementations of the
*note CookiePolicy: 411d. interface must also supply the following
attributes, indicating which protocols should be used, and how.  All of
these attributes may be assigned to.

 -- Attributo: CookiePolicy.netscape

     Implement Netscape protocol.

 -- Attributo: CookiePolicy.rfc2965

     Implement RFC 2965(1) protocol.

 -- Attributo: CookiePolicy.hide_cookie2

     Don’t add ‘Cookie2’ header to requests (the presence of this header
     indicates to the server that we understand RFC 2965(2) cookies).

The most useful way to define a *note CookiePolicy: 411d. class is by
subclassing from *note DefaultCookiePolicy: 1ddc. and overriding some or
all of the methods above.  *note CookiePolicy: 411d. itself may be used
as a “null policy” to allow setting and receiving any and all cookies
(this is unlikely to be useful).

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2965.html

   (2) https://datatracker.ietf.org/doc/html/rfc2965.html


File: python.info,  Node: DefaultCookiePolicy Objects,  Next: Cookie Objects<2>,  Prev: CookiePolicy Objects,  Up: http cookiejar — Cookie handling for HTTP clients

5.22.19.4 DefaultCookiePolicy Objects
.....................................

Implements the standard rules for accepting and returning cookies.

Both RFC 2965(1) and Netscape cookies are covered.  RFC 2965 handling is
switched off by default.

The easiest way to provide your own policy is to override this class and
call its methods in your overridden implementations before adding your
own additional checks:

     import http.cookiejar
     class MyCookiePolicy(http.cookiejar.DefaultCookiePolicy):
         def set_ok(self, cookie, request):
             if not http.cookiejar.DefaultCookiePolicy.set_ok(self, cookie, request):
                 return False
             if i_dont_want_to_store_this_cookie(cookie):
                 return False
             return True

In addition to the features required to implement the *note
CookiePolicy: 411d. interface, this class allows you to block and allow
domains from setting and receiving cookies.  There are also some
strictness switches that allow you to tighten up the rather loose
Netscape protocol rules a little bit (at the cost of blocking some
benign cookies).

A domain blocklist and allowlist is provided (both off by default).
Only domains not in the blocklist and present in the allowlist (if the
allowlist is active) participate in cookie setting and returning.  Use
the 'blocked_domains' constructor argument, and ‘blocked_domains()’ and
‘set_blocked_domains()’ methods (and the corresponding argument and
methods for 'allowed_domains').  If you set an allowlist, you can turn
it off again by setting it to *note None: 886.

Domains in block or allow lists that do not start with a dot must equal
the cookie domain to be matched.  For example, ‘"example.com"’ matches a
blocklist entry of ‘"example.com"’, but ‘"www.example.com"’ does not.
Domains that do start with a dot are matched by more specific domains
too.  For example, both ‘"www.example.com"’ and
‘"www.coyote.example.com"’ match ‘".example.com"’ (but ‘"example.com"’
itself does not).  IP addresses are an exception, and must match
exactly.  For example, if blocked_domains contains ‘"192.168.1.2"’ and
‘".168.1.2"’, 192.168.1.2 is blocked, but 193.168.1.2 is not.

*note DefaultCookiePolicy: 1ddc. implements the following additional
methods:

 -- Metodo: DefaultCookiePolicy.blocked_domains ()

     Return the sequence of blocked domains (as a tuple).

 -- Metodo: DefaultCookiePolicy.set_blocked_domains (blocked_domains)

     Set the sequence of blocked domains.

 -- Metodo: DefaultCookiePolicy.is_blocked (domain)

     Return ‘True’ if 'domain' is on the blocklist for setting or
     receiving cookies.

 -- Metodo: DefaultCookiePolicy.allowed_domains ()

     Return *note None: 886, or the sequence of allowed domains (as a
     tuple).

 -- Metodo: DefaultCookiePolicy.set_allowed_domains (allowed_domains)

     Set the sequence of allowed domains, or *note None: 886.

 -- Metodo: DefaultCookiePolicy.is_not_allowed (domain)

     Return ‘True’ if 'domain' is not on the allowlist for setting or
     receiving cookies.

*note DefaultCookiePolicy: 1ddc. instances have the following
attributes, which are all initialised from the constructor arguments of
the same name, and which may all be assigned to.

 -- Attributo: DefaultCookiePolicy.rfc2109_as_netscape

     If true, request that the *note CookieJar: 3f3a. instance downgrade
     RFC 2109(2) cookies (ie.  cookies received in a ‘Set-Cookie’ header
     with a version cookie-attribute of 1) to Netscape cookies by
     setting the version attribute of the *note Cookie: 4122. instance
     to 0.  The default value is *note None: 886, in which case RFC 2109
     cookies are downgraded if and only if RFC 2965(3) handling is
     turned off.  Therefore, RFC 2109 cookies are downgraded by default.

General strictness switches:

 -- Attributo: DefaultCookiePolicy.strict_domain

     Don’t allow sites to set two-component domains with country-code
     top-level domains like ‘.co.uk’, ‘.gov.uk’, ‘.co.nz’.etc.  This is
     far from perfect and isn’t guaranteed to work!

RFC 2965(4) protocol strictness switches:

 -- Attributo: DefaultCookiePolicy.strict_rfc2965_unverifiable

     Follow RFC 2965(5) rules on unverifiable transactions (usually, an
     unverifiable transaction is one resulting from a redirect or a
     request for an image hosted on another site).  If this is false,
     cookies are 'never' blocked on the basis of verifiability

Netscape protocol strictness switches:

 -- Attributo: DefaultCookiePolicy.strict_ns_unverifiable

     Apply RFC 2965(6) rules on unverifiable transactions even to
     Netscape cookies.

 -- Attributo: DefaultCookiePolicy.strict_ns_domain

     Flags indicating how strict to be with domain-matching rules for
     Netscape cookies.  See below for acceptable values.

 -- Attributo: DefaultCookiePolicy.strict_ns_set_initial_dollar

     Ignore cookies in Set-Cookie: headers that have names starting with
     ‘'$'’.

 -- Attributo: DefaultCookiePolicy.strict_ns_set_path

     Don’t allow setting cookies whose path doesn’t path-match request
     URI.

*note strict_ns_domain: 4147. is a collection of flags.  Its value is
constructed by or-ing together (for example,
‘DomainStrictNoDots|DomainStrictNonDomain’ means both flags are set).

 -- Attributo: DefaultCookiePolicy.DomainStrictNoDots

     When setting cookies, the “host prefix” must not contain a dot (eg.
     ‘www.foo.bar.com’ can’t set a cookie for ‘.bar.com’, because
     ‘www.foo’ contains a dot).

 -- Attributo: DefaultCookiePolicy.DomainStrictNonDomain

     Cookies that did not explicitly specify a ‘domain’ cookie-attribute
     can only be returned to a domain equal to the domain that set the
     cookie (eg.  ‘spam.example.com’ won’t be returned cookies from
     ‘example.com’ that had no ‘domain’ cookie-attribute).

 -- Attributo: DefaultCookiePolicy.DomainRFC2965Match

     When setting cookies, require a full RFC 2965(7) domain-match.

The following attributes are provided for convenience, and are the most
useful combinations of the above flags:

 -- Attributo: DefaultCookiePolicy.DomainLiberal

     Equivalent to 0 (ie.  all of the above Netscape domain strictness
     flags switched off).

 -- Attributo: DefaultCookiePolicy.DomainStrict

     Equivalent to ‘DomainStrictNoDots|DomainStrictNonDomain’.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2965.html

   (2) https://datatracker.ietf.org/doc/html/rfc2109.html

   (3) https://datatracker.ietf.org/doc/html/rfc2965.html

   (4) https://datatracker.ietf.org/doc/html/rfc2965.html

   (5) https://datatracker.ietf.org/doc/html/rfc2965.html

   (6) https://datatracker.ietf.org/doc/html/rfc2965.html

   (7) https://datatracker.ietf.org/doc/html/rfc2965.html


File: python.info,  Node: Cookie Objects<2>,  Next: Examples<30>,  Prev: DefaultCookiePolicy Objects,  Up: http cookiejar — Cookie handling for HTTP clients

5.22.19.5 Cookie Objects
........................

*note Cookie: 4122. instances have Python attributes roughly
corresponding to the standard cookie-attributes specified in the various
cookie standards.  The correspondence is not one-to-one, because there
are complicated rules for assigning default values, because the
‘max-age’ and ‘expires’ cookie-attributes contain equivalent
information, and because RFC 2109(1) cookies may be “downgraded” by
*note http.cookiejar: 74. from version 1 to version 0 (Netscape)
cookies.

Assignment to these attributes should not be necessary other than in
rare circumstances in a *note CookiePolicy: 411d. method.  The class
does not enforce internal consistency, so you should know what you’re
doing if you do that.

 -- Attributo: Cookie.version

     Integer or *note None: 886.  Netscape cookies have *note version:
     4150. 0.  RFC 2965(2) and RFC 2109(3) cookies have a ‘version’
     cookie-attribute of 1.  However, note that *note http.cookiejar:
     74. may “downgrade” RFC 2109 cookies to Netscape cookies, in which
     case *note version: 4150. is 0.

 -- Attributo: Cookie.name

     Cookie name (a string).

 -- Attributo: Cookie.value

     Cookie value (a string), or *note None: 886.

 -- Attributo: Cookie.port

     String representing a port or a set of ports (eg.  “80”, or
     “80,8080”), or *note None: 886.

 -- Attributo: Cookie.domain

     Cookie domain (a string).

 -- Attributo: Cookie.path

     Cookie path (a string, eg.  ‘'/acme/rocket_launchers'’).

 -- Attributo: Cookie.secure

     ‘True’ if cookie should only be returned over a secure connection.

 -- Attributo: Cookie.expires

     Integer expiry date in seconds since epoch, or *note None: 886.
     See also the *note is_expired(): 4158. method.

 -- Attributo: Cookie.discard

     ‘True’ if this is a session cookie.

 -- Attributo: Cookie.comment

     String comment from the server explaining the function of this
     cookie, or *note None: 886.

 -- Attributo: Cookie.comment_url

     URL linking to a comment from the server explaining the function of
     this cookie, or *note None: 886.

 -- Attributo: Cookie.rfc2109

     ‘True’ if this cookie was received as an RFC 2109(4) cookie (ie.
     the cookie arrived in a ‘Set-Cookie’ header, and the value of the
     Version cookie-attribute in that header was 1).  This attribute is
     provided because *note http.cookiejar: 74. may “downgrade” RFC 2109
     cookies to Netscape cookies, in which case *note version: 4150. is
     0.

 -- Attributo: Cookie.port_specified

     ‘True’ if a port or set of ports was explicitly specified by the
     server (in the ‘Set-Cookie’ / ‘Set-Cookie2’ header).

 -- Attributo: Cookie.domain_specified

     ‘True’ if a domain was explicitly specified by the server.

 -- Attributo: Cookie.domain_initial_dot

     ‘True’ if the domain explicitly specified by the server began with
     a dot (‘'.'’).

Cookies may have additional non-standard cookie-attributes.  These may
be accessed using the following methods:

 -- Metodo: Cookie.has_nonstandard_attr (name)

     Return ‘True’ if cookie has the named cookie-attribute.

 -- Metodo: Cookie.get_nonstandard_attr (name, default=None)

     If cookie has the named cookie-attribute, return its value.
     Otherwise, return 'default'.

 -- Metodo: Cookie.set_nonstandard_attr (name, value)

     Set the value of the named cookie-attribute.

The *note Cookie: 4122. class also defines the following method:

 -- Metodo: Cookie.is_expired (now=None)

     ‘True’ if cookie has passed the time at which the server requested
     it should expire.  If 'now' is given (in seconds since the epoch),
     return whether the cookie has expired at the specified time.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2109.html

   (2) https://datatracker.ietf.org/doc/html/rfc2965.html

   (3) https://datatracker.ietf.org/doc/html/rfc2109.html

   (4) https://datatracker.ietf.org/doc/html/rfc2109.html


File: python.info,  Node: Examples<30>,  Prev: Cookie Objects<2>,  Up: http cookiejar — Cookie handling for HTTP clients

5.22.19.6 Examples
..................

The first example shows the most common usage of *note http.cookiejar:
74.:

     import http.cookiejar, urllib.request
     cj = http.cookiejar.CookieJar()
     opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj))
     r = opener.open("http://example.com/")

This example illustrates how to open a URL using your Netscape, Mozilla,
or Lynx cookies (assumes Unix/Netscape convention for location of the
cookies file):

     import os, http.cookiejar, urllib.request
     cj = http.cookiejar.MozillaCookieJar()
     cj.load(os.path.join(os.path.expanduser("~"), ".netscape", "cookies.txt"))
     opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj))
     r = opener.open("http://example.com/")

The next example illustrates the use of *note DefaultCookiePolicy: 1ddc.
Turn on RFC 2965(1) cookies, be more strict about domains when setting
and returning Netscape cookies, and block some domains from setting
cookies or having them returned:

     import urllib.request
     from http.cookiejar import CookieJar, DefaultCookiePolicy
     policy = DefaultCookiePolicy(
         rfc2965=True, strict_ns_domain=Policy.DomainStrict,
         blocked_domains=["ads.net", ".ads.net"])
     cj = CookieJar(policy)
     opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj))
     r = opener.open("http://example.com/")

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2965.html


File: python.info,  Node: xmlrpc — XMLRPC server and client modules,  Next: xmlrpc client — XML-RPC client access,  Prev: http cookiejar — Cookie handling for HTTP clients,  Up: Internet Protocols and Support

5.22.20 ‘xmlrpc’ — XMLRPC server and client modules
---------------------------------------------------

XML-RPC is a Remote Procedure Call method that uses XML passed via HTTP
as a transport.  With it, a client can call methods with parameters on a
remote server (the server is named by a URI) and get back structured
data.

‘xmlrpc’ is a package that collects server and client modules
implementing XML-RPC. The modules are:

   * *note xmlrpc.client: 134.

   * *note xmlrpc.server: 135.


File: python.info,  Node: xmlrpc client — XML-RPC client access,  Next: xmlrpc server — Basic XML-RPC servers,  Prev: xmlrpc — XMLRPC server and client modules,  Up: Internet Protocols and Support

5.22.21 ‘xmlrpc.client’ — XML-RPC client access
-----------------------------------------------

'Source code:' Lib/xmlrpc/client.py(1)

__________________________________________________________________

XML-RPC is a Remote Procedure Call method that uses XML passed via
HTTP(S) as a transport.  With it, a client can call methods with
parameters on a remote server (the server is named by a URI) and get
back structured data.  This module supports writing XML-RPC client code;
it handles all the details of translating between conformable Python
objects and XML on the wire.

     Avvertimento: The *note xmlrpc.client: 134. module is not secure
     against maliciously constructed data.  If you need to parse
     untrusted or unauthenticated data, see *note XML security: 3cd0.

Cambiato nella versione 3.5: For HTTPS URIs, *note xmlrpc.client: 134.
now performs all the necessary certificate and hostname checks by
default.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

 -- Classe: xmlrpc.client.ServerProxy (uri, transport=None,
          encoding=None, verbose=False, allow_none=False,
          use_datetime=False, use_builtin_types=False, *, headers=(),
          context=None)

     A *note ServerProxy: c4e. instance is an object that manages
     communication with a remote XML-RPC server.  The required first
     argument is a URI (Uniform Resource Indicator), and will normally
     be the URL of the server.  The optional second argument is a
     transport factory instance; by default it is an internal
     ‘SafeTransport’ instance for https: URLs and an internal HTTP
     ‘Transport’ instance otherwise.  The optional third argument is an
     encoding, by default UTF-8.  The optional fourth argument is a
     debugging flag.

     The following parameters govern the use of the returned proxy
     instance.  If 'allow_none' is true, the Python constant ‘None’ will
     be translated into XML; the default behaviour is for ‘None’ to
     raise a *note TypeError: 198.  This is a commonly used extension to
     the XML-RPC specification, but isn’t supported by all clients and
     servers; see http://ontosys.com/xml-rpc/extensions.php(2) for a
     description.  The 'use_builtin_types' flag can be used to cause
     date/time values to be presented as *note datetime.datetime: 4e3.
     objects and binary data to be presented as *note bytes: 192.
     objects; this flag is false by default.  *note datetime.datetime:
     4e3, *note bytes: 192. and *note bytearray: 344. objects may be
     passed to calls.  The 'headers' parameter is an optional sequence
     of HTTP headers to send with each request, expressed as a sequence
     of 2-tuples representing the header name and value.  (e.g.
     ‘[('Header-Name', 'value')]’).  If an HTTPS URL is provided,
     'context' may be *note ssl.SSLContext: 357. and configures the SSL
     settings of the underlying HTTPS connection.  The obsolete
     'use_datetime' flag is similar to 'use_builtin_types' but it
     applies only to date/time values.

     Cambiato nella versione 3.3: The 'use_builtin_types' flag was
     added.

     Cambiato nella versione 3.8: The 'headers' parameter was added.

     Both the HTTP and HTTPS transports support the URL syntax extension
     for HTTP Basic Authentication: ‘http://user:pass@host:port/path’.
     The ‘user:pass’ portion will be base64-encoded as an HTTP
     “Authorization” header, and sent to the remote server as part of
     the connection process when invoking an XML-RPC method.  You only
     need to use this if the remote server requires a Basic
     Authentication user and password.

     The returned instance is a proxy object with methods that can be
     used to invoke corresponding RPC calls on the remote server.  If
     the remote server supports the introspection API, the proxy can
     also be used to query the remote server for the methods it supports
     (service discovery) and fetch other server-associated metadata.

     Types that are conformable (e.g.  that can be marshalled through
     XML), include the following (and except where noted, they are
     unmarshalled as the same Python type):

     XML-RPC type               Python type
                                
     ---------------------------------------------------------------------------------------
                                
     ‘boolean’                  *note bool: 3c3.
                                
                                
     ‘int’, ‘i1’, ‘i2’, ‘i4’,   *note int: 19b. in range from -2147483648 to 2147483647.
     ‘i8’ or ‘biginteger’       Values get the ‘<int>’ tag.
                                
                                
     ‘double’ or ‘float’        *note float: 196.  Values get the ‘<double>’ tag.
                                
                                
     ‘string’                   *note str: 169.
                                
                                
     ‘array’                    *note list: 24d. or *note tuple: 614. containing
                                conformable elements.  Arrays are returned as
                                *note lists: 24d.
                                
                                
     ‘struct’                   *note dict: 183.  Keys must be strings, values may be any
                                conformable type.  Objects of user-defined classes can be
                                passed in; only their *note __dict__: 77e. attribute is
                                transmitted.
                                
                                
     ‘dateTime.iso8601’         *note DateTime: 15ea. or *note datetime.datetime: 4e3.
                                Returned type depends on values of 'use_builtin_types'
                                and 'use_datetime' flags.
                                
                                
     ‘base64’                   *note Binary: 416a, *note bytes: 192. or
                                *note bytearray: 344.  Returned type depends on the value
                                of the 'use_builtin_types' flag.
                                
                                
     ‘nil’                      The ‘None’ constant.  Passing is allowed only if
                                'allow_none' is true.
                                
                                
     ‘bigdecimal’               *note decimal.Decimal: 1fe.  Returned type only.
                                

     This is the full set of data types supported by XML-RPC. Method
     calls may also raise a special *note Fault: 416b. instance, used to
     signal XML-RPC server errors, or *note ProtocolError: 416c. used to
     signal an error in the HTTP/HTTPS transport layer.  Both *note
     Fault: 416b. and *note ProtocolError: 416c. derive from a base
     class called ‘Error’.  Note that the xmlrpc client module currently
     does not marshal instances of subclasses of built-in types.

     When passing strings, characters special to XML such as ‘<’, ‘>’,
     and ‘&’ will be automatically escaped.  However, it’s the caller’s
     responsibility to ensure that the string is free of characters that
     aren’t allowed in XML, such as the control characters with ASCII
     values between 0 and 31 (except, of course, tab, newline and
     carriage return); failing to do this will result in an XML-RPC
     request that isn’t well-formed XML. If you have to pass arbitrary
     bytes via XML-RPC, use *note bytes: 192. or *note bytearray: 344.
     classes or the *note Binary: 416a. wrapper class described below.

     ‘Server’ is retained as an alias for *note ServerProxy: c4e. for
     backwards compatibility.  New code should use *note ServerProxy:
     c4e.

     Cambiato nella versione 3.5: Added the 'context' argument.

     Cambiato nella versione 3.6: Added support of type tags with
     prefixes (e.g.  ‘ex:nil’).  Added support of unmarshalling
     additional types used by Apache XML-RPC implementation for
     numerics: ‘i1’, ‘i2’, ‘i8’, ‘biginteger’, ‘float’ and ‘bigdecimal’.
     See ‘https://ws.apache.org/xmlrpc/types.html’ for a description.

Vedi anche
..........

XML-RPC HOWTO(3)

     A good description of XML-RPC operation and client software in
     several languages.  Contains pretty much everything an XML-RPC
     client developer needs to know.

XML-RPC Introspection(4)

     Describes the XML-RPC protocol extension for introspection.

XML-RPC Specification(5)

     The official specification.

* Menu:

* ServerProxy Objects::
* DateTime Objects::
* Binary Objects::
* Fault Objects::
* ProtocolError Objects::
* MultiCall Objects::
* Convenience Functions::
* Example of Client Usage::
* Example of Client and Server Usage::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/xmlrpc/client.py

   (2) 
https://web.archive.org/web/20130120074804/http://ontosys.com/xml-rpc/extensions.php

   (3) https://tldp.org/HOWTO/XML-RPC-HOWTO/index.html

   (4) https://xmlrpc-c.sourceforge.io/introspection.html

   (5) http://xmlrpc.scripting.com/spec.html


File: python.info,  Node: ServerProxy Objects,  Next: DateTime Objects,  Up: xmlrpc client — XML-RPC client access

5.22.21.1 ServerProxy Objects
.............................

A *note ServerProxy: c4e. instance has a method corresponding to each
remote procedure call accepted by the XML-RPC server.  Calling the
method performs an RPC, dispatched by both name and argument signature
(e.g.  the same method name can be overloaded with multiple argument
signatures).  The RPC finishes by returning a value, which may be either
returned data in a conformant type or a *note Fault: 416b. or *note
ProtocolError: 416c. object indicating an error.

Servers that support the XML introspection API support some common
methods grouped under the reserved ‘system’ attribute:

 -- Metodo: ServerProxy.system.listMethods ()

     This method returns a list of strings, one for each (non-system)
     method supported by the XML-RPC server.

 -- Metodo: ServerProxy.system.methodSignature (name)

     This method takes one parameter, the name of a method implemented
     by the XML-RPC server.  It returns an array of possible signatures
     for this method.  A signature is an array of types.  The first of
     these types is the return type of the method, the rest are
     parameters.

     Because multiple signatures (ie.  overloading) is permitted, this
     method returns a list of signatures rather than a singleton.

     Signatures themselves are restricted to the top level parameters
     expected by a method.  For instance if a method expects one array
     of structs as a parameter, and it returns a string, its signature
     is simply «string, array».  If it expects three integers and
     returns a string, its signature is «string, int, int, int».

     If no signature is defined for the method, a non-array value is
     returned.  In Python this means that the type of the returned value
     will be something other than list.

 -- Metodo: ServerProxy.system.methodHelp (name)

     This method takes one parameter, the name of a method implemented
     by the XML-RPC server.  It returns a documentation string
     describing the use of that method.  If no such string is available,
     an empty string is returned.  The documentation string may contain
     HTML markup.

Cambiato nella versione 3.5: Instances of *note ServerProxy: c4e.
support the *note context manager: 1e1. protocol for closing the
underlying transport.

A working example follows.  The server code:

     from xmlrpc.server import SimpleXMLRPCServer

     def is_even(n):
         return n % 2 == 0

     server = SimpleXMLRPCServer(("localhost", 8000))
     print("Listening on port 8000...")
     server.register_function(is_even, "is_even")
     server.serve_forever()

The client code for the preceding server:

     import xmlrpc.client

     with xmlrpc.client.ServerProxy("http://localhost:8000/") as proxy:
         print("3 is even: %s" % str(proxy.is_even(3)))
         print("100 is even: %s" % str(proxy.is_even(100)))


File: python.info,  Node: DateTime Objects,  Next: Binary Objects,  Prev: ServerProxy Objects,  Up: xmlrpc client — XML-RPC client access

5.22.21.2 DateTime Objects
..........................

 -- Classe: xmlrpc.client.DateTime

     This class may be initialized with seconds since the epoch, a time
     tuple, an ISO 8601 time/date string, or a *note datetime.datetime:
     4e3. instance.  It has the following methods, supported mainly for
     internal use by the marshalling/unmarshalling code:

      -- Metodo: decode (string)

          Accept a string as the instance’s new time value.

      -- Metodo: encode (out)

          Write the XML-RPC encoding of this *note DateTime: 15ea. item
          to the 'out' stream object.

     It also supports certain of Python’s built-in operators through
     *note rich comparison: 14a8. and *note __repr__(): 830. methods.

A working example follows.  The server code:

     import datetime
     from xmlrpc.server import SimpleXMLRPCServer
     import xmlrpc.client

     def today():
         today = datetime.datetime.today()
         return xmlrpc.client.DateTime(today)

     server = SimpleXMLRPCServer(("localhost", 8000))
     print("Listening on port 8000...")
     server.register_function(today, "today")
     server.serve_forever()

The client code for the preceding server:

     import xmlrpc.client
     import datetime

     proxy = xmlrpc.client.ServerProxy("http://localhost:8000/")

     today = proxy.today()
     # convert the ISO8601 string to a datetime object
     converted = datetime.datetime.strptime(today.value, "%Y%m%dT%H:%M:%S")
     print("Today: %s" % converted.strftime("%d.%m.%Y, %H:%M"))


File: python.info,  Node: Binary Objects,  Next: Fault Objects,  Prev: DateTime Objects,  Up: xmlrpc client — XML-RPC client access

5.22.21.3 Binary Objects
........................

 -- Classe: xmlrpc.client.Binary

     This class may be initialized from bytes data (which may include
     NULs).  The primary access to the content of a *note Binary: 416a.
     object is provided by an attribute:

      -- Attributo: data

          The binary data encapsulated by the *note Binary: 416a.
          instance.  The data is provided as a *note bytes: 192. object.

     *note Binary: 416a. objects have the following methods, supported
     mainly for internal use by the marshalling/unmarshalling code:

      -- Metodo: decode (bytes)

          Accept a base64 *note bytes: 192. object and decode it as the
          instance’s new data.

      -- Metodo: encode (out)

          Write the XML-RPC base 64 encoding of this binary item to the
          'out' stream object.

          The encoded data will have newlines every 76 characters as per
          RFC 2045 section 6.8(1), which was the de facto standard
          base64 specification when the XML-RPC spec was written.

     It also supports certain of Python’s built-in operators through
     *note __eq__(): cf4. and *note __ne__(): 171e. methods.

Example usage of the binary objects.  We’re going to transfer an image
over XMLRPC:

     from xmlrpc.server import SimpleXMLRPCServer
     import xmlrpc.client

     def python_logo():
         with open("python_logo.jpg", "rb") as handle:
             return xmlrpc.client.Binary(handle.read())

     server = SimpleXMLRPCServer(("localhost", 8000))
     print("Listening on port 8000...")
     server.register_function(python_logo, 'python_logo')

     server.serve_forever()

The client gets the image and saves it to a file:

     import xmlrpc.client

     proxy = xmlrpc.client.ServerProxy("http://localhost:8000/")
     with open("fetched_python_logo.jpg", "wb") as handle:
         handle.write(proxy.python_logo().data)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2045.html#section-6.8


File: python.info,  Node: Fault Objects,  Next: ProtocolError Objects,  Prev: Binary Objects,  Up: xmlrpc client — XML-RPC client access

5.22.21.4 Fault Objects
.......................

 -- Classe: xmlrpc.client.Fault

     A *note Fault: 416b. object encapsulates the content of an XML-RPC
     fault tag.  Fault objects have the following attributes:

      -- Attributo: faultCode

          An int indicating the fault type.

      -- Attributo: faultString

          A string containing a diagnostic message associated with the
          fault.

In the following example we’re going to intentionally cause a *note
Fault: 416b. by returning a complex type object.  The server code:

     from xmlrpc.server import SimpleXMLRPCServer

     # A marshalling error is going to occur because we're returning a
     # complex number
     def add(x, y):
         return x+y+0j

     server = SimpleXMLRPCServer(("localhost", 8000))
     print("Listening on port 8000...")
     server.register_function(add, 'add')

     server.serve_forever()

The client code for the preceding server:

     import xmlrpc.client

     proxy = xmlrpc.client.ServerProxy("http://localhost:8000/")
     try:
         proxy.add(2, 5)
     except xmlrpc.client.Fault as err:
         print("A fault occurred")
         print("Fault code: %d" % err.faultCode)
         print("Fault string: %s" % err.faultString)


File: python.info,  Node: ProtocolError Objects,  Next: MultiCall Objects,  Prev: Fault Objects,  Up: xmlrpc client — XML-RPC client access

5.22.21.5 ProtocolError Objects
...............................

 -- Classe: xmlrpc.client.ProtocolError

     A *note ProtocolError: 416c. object describes a protocol error in
     the underlying transport layer (such as a 404 “not found” error if
     the server named by the URI does not exist).  It has the following
     attributes:

      -- Attributo: url

          The URI or URL that triggered the error.

      -- Attributo: errcode

          The error code.

      -- Attributo: errmsg

          The error message or diagnostic string.

      -- Attributo: headers

          A dict containing the headers of the HTTP/HTTPS request that
          triggered the error.

In the following example we’re going to intentionally cause a *note
ProtocolError: 416c. by providing an invalid URI:

     import xmlrpc.client

     # create a ServerProxy with a URI that doesn't respond to XMLRPC requests
     proxy = xmlrpc.client.ServerProxy("http://google.com/")

     try:
         proxy.some_method()
     except xmlrpc.client.ProtocolError as err:
         print("A protocol error occurred")
         print("URL: %s" % err.url)
         print("HTTP/HTTPS headers: %s" % err.headers)
         print("Error code: %d" % err.errcode)
         print("Error message: %s" % err.errmsg)


File: python.info,  Node: MultiCall Objects,  Next: Convenience Functions,  Prev: ProtocolError Objects,  Up: xmlrpc client — XML-RPC client access

5.22.21.6 MultiCall Objects
...........................

The *note MultiCall: 4186. object provides a way to encapsulate multiple
calls to a remote server into a single request (1).

 -- Classe: xmlrpc.client.MultiCall (server)

     Create an object used to boxcar method calls.  'server' is the
     eventual target of the call.  Calls can be made to the result
     object, but they will immediately return ‘None’, and only store the
     call name and parameters in the *note MultiCall: 4186. object.
     Calling the object itself causes all stored calls to be transmitted
     as a single ‘system.multicall’ request.  The result of this call is
     a *note generator: 1263.; iterating over this generator yields the
     individual results.

A usage example of this class follows.  The server code:

     from xmlrpc.server import SimpleXMLRPCServer

     def add(x, y):
         return x + y

     def subtract(x, y):
         return x - y

     def multiply(x, y):
         return x * y

     def divide(x, y):
         return x // y

     # A simple server with simple arithmetic functions
     server = SimpleXMLRPCServer(("localhost", 8000))
     print("Listening on port 8000...")
     server.register_multicall_functions()
     server.register_function(add, 'add')
     server.register_function(subtract, 'subtract')
     server.register_function(multiply, 'multiply')
     server.register_function(divide, 'divide')
     server.serve_forever()

The client code for the preceding server:

     import xmlrpc.client

     proxy = xmlrpc.client.ServerProxy("http://localhost:8000/")
     multicall = xmlrpc.client.MultiCall(proxy)
     multicall.add(7, 3)
     multicall.subtract(7, 3)
     multicall.multiply(7, 3)
     multicall.divide(7, 3)
     result = multicall()

     print("7+3=%d, 7-3=%d, 7*3=%d, 7//3=%d" % tuple(result))

   ---------- Footnotes ----------

   (1) This approach has been first presented in a discussion on
xmlrpc.com
(https://web.archive.org/web/20060624230303/http://www.xmlrpc.com/discuss/msgReader$1208?mode=topic).


File: python.info,  Node: Convenience Functions,  Next: Example of Client Usage,  Prev: MultiCall Objects,  Up: xmlrpc client — XML-RPC client access

5.22.21.7 Convenience Functions
...............................

 -- Funzione: xmlrpc.client.dumps (params, methodname=None,
          methodresponse=None, encoding=None, allow_none=False)

     Convert 'params' into an XML-RPC request, or into a response if
     'methodresponse' is true.  'params' can be either a tuple of
     arguments or an instance of the *note Fault: 416b. exception class.
     If 'methodresponse' is true, only a single value can be returned,
     meaning that 'params' must be of length 1.  'encoding', if
     supplied, is the encoding to use in the generated XML; the default
     is UTF-8.  Python’s *note None: 886. value cannot be used in
     standard XML-RPC; to allow using it via an extension, provide a
     true value for 'allow_none'.

 -- Funzione: xmlrpc.client.loads (data, use_datetime=False,
          use_builtin_types=False)

     Convert an XML-RPC request or response into Python objects, a
     ‘(params, methodname)’.  'params' is a tuple of argument;
     'methodname' is a string, or ‘None’ if no method name is present in
     the packet.  If the XML-RPC packet represents a fault condition,
     this function will raise a *note Fault: 416b. exception.  The
     'use_builtin_types' flag can be used to cause date/time values to
     be presented as *note datetime.datetime: 4e3. objects and binary
     data to be presented as *note bytes: 192. objects; this flag is
     false by default.

     The obsolete 'use_datetime' flag is similar to 'use_builtin_types'
     but it applies only to date/time values.

     Cambiato nella versione 3.3: The 'use_builtin_types' flag was
     added.


File: python.info,  Node: Example of Client Usage,  Next: Example of Client and Server Usage,  Prev: Convenience Functions,  Up: xmlrpc client — XML-RPC client access

5.22.21.8 Example of Client Usage
.................................

     # simple test program (from the XML-RPC specification)
     from xmlrpc.client import ServerProxy, Error

     # server = ServerProxy("http://localhost:8000") # local server
     with ServerProxy("http://betty.userland.com") as proxy:

         print(proxy)

         try:
             print(proxy.examples.getStateName(41))
         except Error as v:
             print("ERROR", v)

To access an XML-RPC server through a HTTP proxy, you need to define a
custom transport.  The following example shows how:

     import http.client
     import xmlrpc.client

     class ProxiedTransport(xmlrpc.client.Transport):

         def set_proxy(self, host, port=None, headers=None):
             self.proxy = host, port
             self.proxy_headers = headers

         def make_connection(self, host):
             connection = http.client.HTTPConnection(*self.proxy)
             connection.set_tunnel(host, headers=self.proxy_headers)
             self._connection = host, connection
             return connection

     transport = ProxiedTransport()
     transport.set_proxy('proxy-server', 8080)
     server = xmlrpc.client.ServerProxy('http://betty.userland.com', transport=transport)
     print(server.examples.getStateName(41))


File: python.info,  Node: Example of Client and Server Usage,  Prev: Example of Client Usage,  Up: xmlrpc client — XML-RPC client access

5.22.21.9 Example of Client and Server Usage
............................................

See *note SimpleXMLRPCServer Example: 418c.


File: python.info,  Node: xmlrpc server — Basic XML-RPC servers,  Next: ipaddress — IPv4/IPv6 manipulation library,  Prev: xmlrpc client — XML-RPC client access,  Up: Internet Protocols and Support

5.22.22 ‘xmlrpc.server’ — Basic XML-RPC servers
-----------------------------------------------

'Source code:' Lib/xmlrpc/server.py(1)

__________________________________________________________________

The *note xmlrpc.server: 135. module provides a basic server framework
for XML-RPC servers written in Python.  Servers can either be free
standing, using *note SimpleXMLRPCServer: 4190, or embedded in a CGI
environment, using *note CGIXMLRPCRequestHandler: 4191.

     Avvertimento: The *note xmlrpc.server: 135. module is not secure
     against maliciously constructed data.  If you need to parse
     untrusted or unauthenticated data, see *note XML security: 3cd0.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

 -- Classe: xmlrpc.server.SimpleXMLRPCServer (addr,
          requestHandler=SimpleXMLRPCRequestHandler, logRequests=True,
          allow_none=False, encoding=None, bind_and_activate=True,
          use_builtin_types=False)

     Create a new server instance.  This class provides methods for
     registration of functions that can be called by the XML-RPC
     protocol.  The 'requestHandler' parameter should be a factory for
     request handler instances; it defaults to *note
     SimpleXMLRPCRequestHandler: 152f.  The 'addr' and 'requestHandler'
     parameters are passed to the *note socketserver.TCPServer: 1527.
     constructor.  If 'logRequests' is true (the default), requests will
     be logged; setting this parameter to false will turn off logging.
     The 'allow_none' and 'encoding' parameters are passed on to *note
     xmlrpc.client: 134. and control the XML-RPC responses that will be
     returned from the server.  The 'bind_and_activate' parameter
     controls whether ‘server_bind()’ and ‘server_activate()’ are called
     immediately by the constructor; it defaults to true.  Setting it to
     false allows code to manipulate the 'allow_reuse_address' class
     variable before the address is bound.  The 'use_builtin_types'
     parameter is passed to the *note loads(): 163c. function and
     controls which types are processed when date/times values or binary
     data are received; it defaults to false.

     Cambiato nella versione 3.3: The 'use_builtin_types' flag was
     added.

 -- Classe: xmlrpc.server.CGIXMLRPCRequestHandler (allow_none=False,
          encoding=None, use_builtin_types=False)

     Create a new instance to handle XML-RPC requests in a CGI
     environment.  The 'allow_none' and 'encoding' parameters are passed
     on to *note xmlrpc.client: 134. and control the XML-RPC responses
     that will be returned from the server.  The 'use_builtin_types'
     parameter is passed to the *note loads(): 163c. function and
     controls which types are processed when date/times values or binary
     data are received; it defaults to false.

     Cambiato nella versione 3.3: The 'use_builtin_types' flag was
     added.

 -- Classe: xmlrpc.server.SimpleXMLRPCRequestHandler

     Create a new request handler instance.  This request handler
     supports ‘POST’ requests and modifies logging so that the
     'logRequests' parameter to the *note SimpleXMLRPCServer: 4190.
     constructor parameter is honored.

* Menu:

* SimpleXMLRPCServer Objects::
* CGIXMLRPCRequestHandler::
* Documenting XMLRPC server::
* DocXMLRPCServer Objects::
* DocCGIXMLRPCRequestHandler::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/xmlrpc/server.py


File: python.info,  Node: SimpleXMLRPCServer Objects,  Next: CGIXMLRPCRequestHandler,  Up: xmlrpc server — Basic XML-RPC servers

5.22.22.1 SimpleXMLRPCServer Objects
....................................

The *note SimpleXMLRPCServer: 4190. class is based on *note
socketserver.TCPServer: 1527. and provides a means of creating simple,
stand alone XML-RPC servers.

 -- Metodo: SimpleXMLRPCServer.register_function (function=None,
          name=None)

     Register a function that can respond to XML-RPC requests.  If
     'name' is given, it will be the method name associated with
     'function', otherwise *note function.__name__: 14dc. will be used.
     'name' is a string, and may contain characters not legal in Python
     identifiers, including the period character.

     This method can also be used as a decorator.  When used as a
     decorator, 'name' can only be given as a keyword argument to
     register 'function' under 'name'.  If no 'name' is given, *note
     function.__name__: 14dc. will be used.

     Cambiato nella versione 3.7: *note register_function(): 4194. can
     be used as a decorator.

 -- Metodo: SimpleXMLRPCServer.register_instance (instance,
          allow_dotted_names=False)

     Register an object which is used to expose method names which have
     not been registered using *note register_function(): 4194.  If
     'instance' contains a ‘_dispatch()’ method, it is called with the
     requested method name and the parameters from the request.  Its API
     is ‘def _dispatch(self, method, params)’ (note that 'params' does
     not represent a variable argument list).  If it calls an underlying
     function to perform its task, that function is called as
     ‘func(*params)’, expanding the parameter list.  The return value
     from ‘_dispatch()’ is returned to the client as the result.  If
     'instance' does not have a ‘_dispatch()’ method, it is searched for
     an attribute matching the name of the requested method.

     If the optional 'allow_dotted_names' argument is true and the
     instance does not have a ‘_dispatch()’ method, then if the
     requested method name contains periods, each component of the
     method name is searched for individually, with the effect that a
     simple hierarchical search is performed.  The value found from this
     search is then called with the parameters from the request, and the
     return value is passed back to the client.

          Avvertimento: Enabling the 'allow_dotted_names' option allows
          intruders to access your module’s global variables and may
          allow intruders to execute arbitrary code on your machine.
          Only use this option on a secure, closed network.

 -- Metodo: SimpleXMLRPCServer.register_introspection_functions ()

     Registers the XML-RPC introspection functions ‘system.listMethods’,
     ‘system.methodHelp’ and ‘system.methodSignature’.

 -- Metodo: SimpleXMLRPCServer.register_multicall_functions ()

     Registers the XML-RPC multicall function system.multicall.

 -- Attributo: SimpleXMLRPCRequestHandler.rpc_paths

     An attribute value that must be a tuple listing valid path portions
     of the URL for receiving XML-RPC requests.  Requests posted to
     other paths will result in a 404 «no such page» HTTP error.  If
     this tuple is empty, all paths will be considered valid.  The
     default value is ‘('/', '/RPC2')’.

* Menu:

* SimpleXMLRPCServer Example::


File: python.info,  Node: SimpleXMLRPCServer Example,  Up: SimpleXMLRPCServer Objects

5.22.22.2 SimpleXMLRPCServer Example
....................................

Server code:

     from xmlrpc.server import SimpleXMLRPCServer
     from xmlrpc.server import SimpleXMLRPCRequestHandler

     # Restrict to a particular path.
     class RequestHandler(SimpleXMLRPCRequestHandler):
         rpc_paths = ('/RPC2',)

     # Create server
     with SimpleXMLRPCServer(('localhost', 8000),
                             requestHandler=RequestHandler) as server:
         server.register_introspection_functions()

         # Register pow() function; this will use the value of
         # pow.__name__ as the name, which is just 'pow'.
         server.register_function(pow)

         # Register a function under a different name
         def adder_function(x, y):
             return x + y
         server.register_function(adder_function, 'add')

         # Register an instance; all the methods of the instance are
         # published as XML-RPC methods (in this case, just 'mul').
         class MyFuncs:
             def mul(self, x, y):
                 return x * y

         server.register_instance(MyFuncs())

         # Run the server's main loop
         server.serve_forever()

The following client code will call the methods made available by the
preceding server:

     import xmlrpc.client

     s = xmlrpc.client.ServerProxy('http://localhost:8000')
     print(s.pow(2,3))  # Returns 2**3 = 8
     print(s.add(2,3))  # Returns 5
     print(s.mul(5,2))  # Returns 5*2 = 10

     # Print list of available methods
     print(s.system.listMethods())

‘register_function()’ can also be used as a decorator.  The previous
server example can register functions in a decorator way:

     from xmlrpc.server import SimpleXMLRPCServer
     from xmlrpc.server import SimpleXMLRPCRequestHandler

     class RequestHandler(SimpleXMLRPCRequestHandler):
         rpc_paths = ('/RPC2',)

     with SimpleXMLRPCServer(('localhost', 8000),
                             requestHandler=RequestHandler) as server:
         server.register_introspection_functions()

         # Register pow() function; this will use the value of
         # pow.__name__ as the name, which is just 'pow'.
         server.register_function(pow)

         # Register a function under a different name, using
         # register_function as a decorator. *name* can only be given
         # as a keyword argument.
         @server.register_function(name='add')
         def adder_function(x, y):
             return x + y

         # Register a function under function.__name__.
         @server.register_function
         def mul(x, y):
             return x * y

         server.serve_forever()

The following example included in the ‘Lib/xmlrpc/server.py’ module
shows a server allowing dotted names and registering a multicall
function.

     Avvertimento: Enabling the 'allow_dotted_names' option allows
     intruders to access your module’s global variables and may allow
     intruders to execute arbitrary code on your machine.  Only use this
     example only within a secure, closed network.

     import datetime

     class ExampleService:
         def getData(self):
             return '42'

         class currentTime:
             @staticmethod
             def getCurrentTime():
                 return datetime.datetime.now()

     with SimpleXMLRPCServer(("localhost", 8000)) as server:
         server.register_function(pow)
         server.register_function(lambda x,y: x+y, 'add')
         server.register_instance(ExampleService(), allow_dotted_names=True)
         server.register_multicall_functions()
         print('Serving XML-RPC on localhost port 8000')
         try:
             server.serve_forever()
         except KeyboardInterrupt:
             print("\nKeyboard interrupt received, exiting.")
             sys.exit(0)

This ExampleService demo can be invoked from the command line:

     python -m xmlrpc.server

The client that interacts with the above server is included in
‘Lib/xmlrpc/client.py’:

     server = ServerProxy("http://localhost:8000")

     try:
         print(server.currentTime.getCurrentTime())
     except Error as v:
         print("ERROR", v)

     multi = MultiCall(server)
     multi.getData()
     multi.pow(2,9)
     multi.add(1,2)
     try:
         for response in multi():
             print(response)
     except Error as v:
         print("ERROR", v)

This client which interacts with the demo XMLRPC server can be invoked
as:

     python -m xmlrpc.client


File: python.info,  Node: CGIXMLRPCRequestHandler,  Next: Documenting XMLRPC server,  Prev: SimpleXMLRPCServer Objects,  Up: xmlrpc server — Basic XML-RPC servers

5.22.22.3 CGIXMLRPCRequestHandler
.................................

The *note CGIXMLRPCRequestHandler: 4191. class can be used to handle
XML-RPC requests sent to Python CGI scripts.

 -- Metodo: CGIXMLRPCRequestHandler.register_function (function=None,
          name=None)

     Register a function that can respond to XML-RPC requests.  If
     'name' is given, it will be the method name associated with
     'function', otherwise *note function.__name__: 14dc. will be used.
     'name' is a string, and may contain characters not legal in Python
     identifiers, including the period character.

     This method can also be used as a decorator.  When used as a
     decorator, 'name' can only be given as a keyword argument to
     register 'function' under 'name'.  If no 'name' is given, *note
     function.__name__: 14dc. will be used.

     Cambiato nella versione 3.7: *note register_function(): 419b. can
     be used as a decorator.

 -- Metodo: CGIXMLRPCRequestHandler.register_instance (instance)

     Register an object which is used to expose method names which have
     not been registered using *note register_function(): 419b.  If
     instance contains a ‘_dispatch()’ method, it is called with the
     requested method name and the parameters from the request; the
     return value is returned to the client as the result.  If instance
     does not have a ‘_dispatch()’ method, it is searched for an
     attribute matching the name of the requested method; if the
     requested method name contains periods, each component of the
     method name is searched for individually, with the effect that a
     simple hierarchical search is performed.  The value found from this
     search is then called with the parameters from the request, and the
     return value is passed back to the client.

 -- Metodo: CGIXMLRPCRequestHandler.register_introspection_functions ()

     Register the XML-RPC introspection functions ‘system.listMethods’,
     ‘system.methodHelp’ and ‘system.methodSignature’.

 -- Metodo: CGIXMLRPCRequestHandler.register_multicall_functions ()

     Register the XML-RPC multicall function ‘system.multicall’.

 -- Metodo: CGIXMLRPCRequestHandler.handle_request (request_text=None)

     Handle an XML-RPC request.  If 'request_text' is given, it should
     be the POST data provided by the HTTP server, otherwise the
     contents of stdin will be used.

Example:

     class MyFuncs:
         def mul(self, x, y):
             return x * y


     handler = CGIXMLRPCRequestHandler()
     handler.register_function(pow)
     handler.register_function(lambda x,y: x+y, 'add')
     handler.register_introspection_functions()
     handler.register_instance(MyFuncs())
     handler.handle_request()


File: python.info,  Node: Documenting XMLRPC server,  Next: DocXMLRPCServer Objects,  Prev: CGIXMLRPCRequestHandler,  Up: xmlrpc server — Basic XML-RPC servers

5.22.22.4 Documenting XMLRPC server
...................................

These classes extend the above classes to serve HTML documentation in
response to HTTP GET requests.  Servers can either be free standing,
using *note DocXMLRPCServer: 1d8e, or embedded in a CGI environment,
using *note DocCGIXMLRPCRequestHandler: 41a1.

 -- Classe: xmlrpc.server.DocXMLRPCServer (addr,
          requestHandler=DocXMLRPCRequestHandler, logRequests=True,
          allow_none=False, encoding=None, bind_and_activate=True,
          use_builtin_types=True)

     Create a new server instance.  All parameters have the same meaning
     as for *note SimpleXMLRPCServer: 4190.; 'requestHandler' defaults
     to *note DocXMLRPCRequestHandler: 41a2.

     Cambiato nella versione 3.3: The 'use_builtin_types' flag was
     added.

 -- Classe: xmlrpc.server.DocCGIXMLRPCRequestHandler

     Create a new instance to handle XML-RPC requests in a CGI
     environment.

 -- Classe: xmlrpc.server.DocXMLRPCRequestHandler

     Create a new request handler instance.  This request handler
     supports XML-RPC POST requests, documentation GET requests, and
     modifies logging so that the 'logRequests' parameter to the *note
     DocXMLRPCServer: 1d8e. constructor parameter is honored.


File: python.info,  Node: DocXMLRPCServer Objects,  Next: DocCGIXMLRPCRequestHandler,  Prev: Documenting XMLRPC server,  Up: xmlrpc server — Basic XML-RPC servers

5.22.22.5 DocXMLRPCServer Objects
.................................

The *note DocXMLRPCServer: 1d8e. class is derived from *note
SimpleXMLRPCServer: 4190. and provides a means of creating
self-documenting, stand alone XML-RPC servers.  HTTP POST requests are
handled as XML-RPC method calls.  HTTP GET requests are handled by
generating pydoc-style HTML documentation.  This allows a server to
provide its own web-based documentation.

 -- Metodo: DocXMLRPCServer.set_server_title (server_title)

     Set the title used in the generated HTML documentation.  This title
     will be used inside the HTML «title» element.

 -- Metodo: DocXMLRPCServer.set_server_name (server_name)

     Set the name used in the generated HTML documentation.  This name
     will appear at the top of the generated documentation inside a «h1»
     element.

 -- Metodo: DocXMLRPCServer.set_server_documentation
          (server_documentation)

     Set the description used in the generated HTML documentation.  This
     description will appear as a paragraph, below the server name, in
     the documentation.


File: python.info,  Node: DocCGIXMLRPCRequestHandler,  Prev: DocXMLRPCServer Objects,  Up: xmlrpc server — Basic XML-RPC servers

5.22.22.6 DocCGIXMLRPCRequestHandler
....................................

The *note DocCGIXMLRPCRequestHandler: 41a1. class is derived from *note
CGIXMLRPCRequestHandler: 4191. and provides a means of creating
self-documenting, XML-RPC CGI scripts.  HTTP POST requests are handled
as XML-RPC method calls.  HTTP GET requests are handled by generating
pydoc-style HTML documentation.  This allows a server to provide its own
web-based documentation.

 -- Metodo: DocCGIXMLRPCRequestHandler.set_server_title (server_title)

     Set the title used in the generated HTML documentation.  This title
     will be used inside the HTML «title» element.

 -- Metodo: DocCGIXMLRPCRequestHandler.set_server_name (server_name)

     Set the name used in the generated HTML documentation.  This name
     will appear at the top of the generated documentation inside a «h1»
     element.

 -- Metodo: DocCGIXMLRPCRequestHandler.set_server_documentation
          (server_documentation)

     Set the description used in the generated HTML documentation.  This
     description will appear as a paragraph, below the server name, in
     the documentation.


File: python.info,  Node: ipaddress — IPv4/IPv6 manipulation library,  Prev: xmlrpc server — Basic XML-RPC servers,  Up: Internet Protocols and Support

5.22.23 ‘ipaddress’ — IPv4/IPv6 manipulation library
----------------------------------------------------

'Source code:' Lib/ipaddress.py(1)

__________________________________________________________________

*note ipaddress: 84. provides the capabilities to create, manipulate and
operate on IPv4 and IPv6 addresses and networks.

The functions and classes in this module make it straightforward to
handle various tasks related to IP addresses, including checking whether
or not two hosts are on the same subnet, iterating over all hosts in a
particular subnet, checking whether or not a string represents a valid
IP address or network definition, and so on.

This is the full module API reference—for an overview and introduction,
see *note An introduction to the ipaddress module: 41af.

Added in version 3.3.

* Menu:

* Convenience factory functions::
* IP Addresses::
* IP Network definitions::
* Interface objects::
* Other Module Level Functions::
* Custom Exceptions::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/ipaddress.py


File: python.info,  Node: Convenience factory functions,  Next: IP Addresses,  Up: ipaddress — IPv4/IPv6 manipulation library

5.22.23.1 Convenience factory functions
.......................................

The *note ipaddress: 84. module provides factory functions to
conveniently create IP addresses, networks and interfaces:

 -- Funzione: ipaddress.ip_address (address)

     Return an *note IPv4Address: 50d. or *note IPv6Address: 50e. object
     depending on the IP address passed as argument.  Either IPv4 or
     IPv6 addresses may be supplied; integers less than ‘2**32’ will be
     considered to be IPv4 by default.  A *note ValueError: 2ec. is
     raised if 'address' does not represent a valid IPv4 or IPv6
     address.

          >>> ipaddress.ip_address('192.168.0.1')
          IPv4Address('192.168.0.1')
          >>> ipaddress.ip_address('2001:db8::')
          IPv6Address('2001:db8::')

 -- Funzione: ipaddress.ip_network (address, strict=True)

     Return an *note IPv4Network: 50f. or *note IPv6Network: 510. object
     depending on the IP address passed as argument.  'address' is a
     string or integer representing the IP network.  Either IPv4 or IPv6
     networks may be supplied; integers less than ‘2**32’ will be
     considered to be IPv4 by default.  'strict' is passed to *note
     IPv4Network: 50f. or *note IPv6Network: 510. constructor.  A *note
     ValueError: 2ec. is raised if 'address' does not represent a valid
     IPv4 or IPv6 address, or if the network has host bits set.

          >>> ipaddress.ip_network('192.168.0.0/28')
          IPv4Network('192.168.0.0/28')

 -- Funzione: ipaddress.ip_interface (address)

     Return an *note IPv4Interface: 1b81. or *note IPv6Interface: 1b82.
     object depending on the IP address passed as argument.  'address'
     is a string or integer representing the IP address.  Either IPv4 or
     IPv6 addresses may be supplied; integers less than ‘2**32’ will be
     considered to be IPv4 by default.  A *note ValueError: 2ec. is
     raised if 'address' does not represent a valid IPv4 or IPv6
     address.

One downside of these convenience functions is that the need to handle
both IPv4 and IPv6 formats means that error messages provide minimal
information on the precise error, as the functions don’t know whether
the IPv4 or IPv6 format was intended.  More detailed error reporting can
be obtained by calling the appropriate version specific class
constructors directly.


File: python.info,  Node: IP Addresses,  Next: IP Network definitions,  Prev: Convenience factory functions,  Up: ipaddress — IPv4/IPv6 manipulation library

5.22.23.2 IP Addresses
......................

* Menu:

* Address objects::
* Conversion to Strings and Integers::
* Operators: Operators<2>.


File: python.info,  Node: Address objects,  Next: Conversion to Strings and Integers,  Up: IP Addresses

5.22.23.3 Address objects
.........................

The *note IPv4Address: 50d. and *note IPv6Address: 50e. objects share a
lot of common attributes.  Some attributes that are only meaningful for
IPv6 addresses are also implemented by *note IPv4Address: 50d. objects,
in order to make it easier to write code that handles both IP versions
correctly.  Address objects are *note hashable: 825, so they can be used
as keys in dictionaries.

 -- Classe: ipaddress.IPv4Address (address)

     Construct an IPv4 address.  An *note AddressValueError: 41b6. is
     raised if 'address' is not a valid IPv4 address.

     The following constitutes a valid IPv4 address:

       1. A string in decimal-dot notation, consisting of four decimal
          integers in the inclusive range 0–255, separated by dots (e.g.
          ‘192.168.0.1’).  Each integer represents an octet (byte) in
          the address.  Leading zeroes are not tolerated to prevent
          confusion with octal notation.

       2. An integer that fits into 32 bits.

       3. An integer packed into a *note bytes: 192. object of length 4
          (most significant octet first).

          >>> ipaddress.IPv4Address('192.168.0.1')
          IPv4Address('192.168.0.1')
          >>> ipaddress.IPv4Address(3232235521)
          IPv4Address('192.168.0.1')
          >>> ipaddress.IPv4Address(b'\xC0\xA8\x00\x01')
          IPv4Address('192.168.0.1')

     Cambiato nella versione 3.8: Leading zeros are tolerated, even in
     ambiguous cases that look like octal notation.

     Cambiato nella versione 3.9.5: Leading zeros are no longer
     tolerated and are treated as an error.  IPv4 address strings are
     now parsed as strict as glibc *note inet_pton(): b5d.

      -- Attributo: version

          The appropriate version number: ‘4’ for IPv4, ‘6’ for IPv6.

          Cambiato nella versione 3.14: Made available on the class.

      -- Attributo: max_prefixlen

          The total number of bits in the address representation for
          this version: ‘32’ for IPv4, ‘128’ for IPv6.

          The prefix defines the number of leading bits in an address
          that are compared to determine whether or not an address is
          part of a network.

          Cambiato nella versione 3.14: Made available on the class.

      -- Attributo: compressed

      -- Attributo: exploded

          The string representation in dotted decimal notation.  Leading
          zeroes are never included in the representation.

          As IPv4 does not define a shorthand notation for addresses
          with octets set to zero, these two attributes are always the
          same as ‘str(addr)’ for IPv4 addresses.  Exposing these
          attributes makes it easier to write display code that can
          handle both IPv4 and IPv6 addresses.

      -- Attributo: packed

          The binary representation of this address - a *note bytes:
          192. object of the appropriate length (most significant octet
          first).  This is 4 bytes for IPv4 and 16 bytes for IPv6.

      -- Attributo: reverse_pointer

          The name of the reverse DNS PTR record for the IP address,
          e.g.:

               >>> ipaddress.ip_address("127.0.0.1").reverse_pointer
               '1.0.0.127.in-addr.arpa'
               >>> ipaddress.ip_address("2001:db8::1").reverse_pointer
               '1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa'

          This is the name that could be used for performing a PTR
          lookup, not the resolved hostname itself.

          Added in version 3.5.

      -- Attributo: is_multicast

          ‘True’ if the address is reserved for multicast use.  See RFC
          3171(1) (for IPv4) or RFC 2373(2) (for IPv6).

      -- Attributo: is_private

          ‘True’ if the address is defined as not globally reachable by
          iana-ipv4-special-registry(3) (for IPv4) or
          iana-ipv6-special-registry(4) (for IPv6) with the following
          exceptions:

             * ‘is_private’ is ‘False’ for the shared address space
               (‘100.64.0.0/10’)

             * For IPv4-mapped IPv6-addresses the ‘is_private’ value is
               determined by the semantics of the underlying IPv4
               addresses and the following condition holds (see *note
               IPv6Address.ipv4_mapped: 41bd.):

                    address.is_private == address.ipv4_mapped.is_private

          ‘is_private’ has value opposite to *note is_global: 1161,
          except for the shared address space (‘100.64.0.0/10’ range)
          where they are both ‘False’.

          Cambiato nella versione 3.13: Fixed some false positives and
          false negatives.

             * ‘192.0.0.0/24’ is considered private with the exception
               of ‘192.0.0.9/32’ and ‘192.0.0.10/32’ (previously: only
               the ‘192.0.0.0/29’ sub-range was considered private).

             * ‘64:ff9b:1::/48’ is considered private.

             * ‘2002::/16’ is considered private.

             * There are exceptions within ‘2001::/23’ (otherwise
               considered private): ‘2001:1::1/128’, ‘2001:1::2/128’,
               ‘2001:3::/32’, ‘2001:4:112::/48’, ‘2001:20::/28’,
               ‘2001:30::/28’.  The exceptions are not considered
               private.

      -- Attributo: is_global

          ‘True’ if the address is defined as globally reachable by
          iana-ipv4-special-registry(5) (for IPv4) or
          iana-ipv6-special-registry(6) (for IPv6) with the following
          exception:

          For IPv4-mapped IPv6-addresses the ‘is_private’ value is
          determined by the semantics of the underlying IPv4 addresses
          and the following condition holds (see *note
          IPv6Address.ipv4_mapped: 41bd.):

               address.is_global == address.ipv4_mapped.is_global

          ‘is_global’ has value opposite to *note is_private: 19ab,
          except for the shared address space (‘100.64.0.0/10’ range)
          where they are both ‘False’.

          Added in version 3.4.

          Cambiato nella versione 3.13: Fixed some false positives and
          false negatives, see *note is_private: 19ab. for details.

      -- Attributo: is_unspecified

          ‘True’ if the address is unspecified.  See RFC 5735(7) (for
          IPv4) or RFC 2373(8) (for IPv6).

      -- Attributo: is_reserved

          ‘True’ if the address is noted as reserved by the IETF. For
          IPv4, this is only ‘240.0.0.0/4’, the ‘Reserved’ address
          block.  For IPv6, this is all addresses allocated(9) as
          ‘Reserved by IETF’ for future use.

               Nota: For IPv4, ‘is_reserved’ is not related to the
               address block value of the ‘Reserved-by-Protocol’ column
               in iana-ipv4-special-registry(10).

               Attenzione: For IPv6, ‘fec0::/10’ a former Site-Local
               scoped address prefix is currently excluded from that
               list (see *note is_site_local: 41c0. & RFC 3879(11)).

      -- Attributo: is_loopback

          ‘True’ if this is a loopback address.  See RFC 3330(12) (for
          IPv4) or RFC 2373(13) (for IPv6).

      -- Attributo: is_link_local

          ‘True’ if the address is reserved for link-local usage.  See
          RFC 3927(14).

      -- Attributo: ipv6_mapped

          *note IPv4Address: 50d. object representing the IPv4-mapped
          IPv6 address.  See RFC 4291(15).

          Added in version 3.13.

 -- Metodo: IPv4Address.__format__ (fmt)

     Returns a string representation of the IP address, controlled by an
     explicit format string.  'fmt' can be one of the following: ‘'s'’,
     the default option, equivalent to *note str(): 169, ‘'b'’ for a
     zero-padded binary string, ‘'X'’ or ‘'x'’ for an uppercase or
     lowercase hexadecimal representation, or ‘'n'’, which is equivalent
     to ‘'b'’ for IPv4 addresses and ‘'x'’ for IPv6.  For binary and
     hexadecimal representations, the form specifier ‘'#'’ and the
     grouping option ‘'_'’ are available.  ‘__format__’ is used by
     ‘format’, ‘str.format’ and f-strings.

          >>> format(ipaddress.IPv4Address('192.168.0.1'))
          '192.168.0.1'
          >>> '{:#b}'.format(ipaddress.IPv4Address('192.168.0.1'))
          '0b11000000101010000000000000000001'
          >>> f'{ipaddress.IPv6Address("2001:db8::1000"):s}'
          '2001:db8::1000'
          >>> format(ipaddress.IPv6Address('2001:db8::1000'), '_X')
          '2001_0DB8_0000_0000_0000_0000_0000_1000'
          >>> '{:#_n}'.format(ipaddress.IPv6Address('2001:db8::1000'))
          '0x2001_0db8_0000_0000_0000_0000_0000_1000'

     Added in version 3.9.

 -- Classe: ipaddress.IPv6Address (address)

     Construct an IPv6 address.  An *note AddressValueError: 41b6. is
     raised if 'address' is not a valid IPv6 address.

     The following constitutes a valid IPv6 address:

       1. A string consisting of eight groups of four hexadecimal
          digits, each group representing 16 bits.  The groups are
          separated by colons.  This describes an 'exploded' (longhand)
          notation.  The string can also be 'compressed' (shorthand
          notation) by various means.  See RFC 4291(16) for details.
          For example, ‘"0000:0000:0000:0000:0000:0abc:0007:0def"’ can
          be compressed to ‘"::abc:7:def"’.

          Optionally, the string may also have a scope zone ID,
          expressed with a suffix ‘%scope_id’.  If present, the scope ID
          must be non-empty, and may not contain ‘%’.  See RFC 4007(17)
          for details.  For example, ‘fe80::1234%1’ might identify
          address ‘fe80::1234’ on the first link of the node.

       2. An integer that fits into 128 bits.

       3. An integer packed into a *note bytes: 192. object of length
          16, big-endian.

          >>> ipaddress.IPv6Address('2001:db8::1000')
          IPv6Address('2001:db8::1000')
          >>> ipaddress.IPv6Address('ff02::5678%1')
          IPv6Address('ff02::5678%1')

      -- Attributo: compressed

     The short form of the address representation, with leading zeroes
     in groups omitted and the longest sequence of groups consisting
     entirely of zeroes collapsed to a single empty group.

     This is also the value returned by ‘str(addr)’ for IPv6 addresses.

      -- Attributo: exploded

     The long form of the address representation, with all leading
     zeroes and groups consisting entirely of zeroes included.

     For the following attributes and methods, see the corresponding
     documentation of the *note IPv4Address: 50d. class:

      -- Attributo: packed

      -- Attributo: reverse_pointer

      -- Attributo: version

      -- Attributo: max_prefixlen

      -- Attributo: is_multicast

      -- Attributo: is_private

      -- Attributo: is_global

          Added in version 3.4.

      -- Attributo: is_unspecified

      -- Attributo: is_reserved

      -- Attributo: is_loopback

      -- Attributo: is_link_local

      -- Attributo: is_site_local

          ‘True’ if the address is reserved for site-local usage.  Note
          that the site-local address space has been deprecated by RFC
          3879(18).  Use *note is_private: 19ab. to test if this address
          is in the space of unique local addresses as defined by RFC
          4193(19).

      -- Attributo: ipv4_mapped

          For addresses that appear to be IPv4 mapped addresses
          (starting with ‘::FFFF/96’), this property will report the
          embedded IPv4 address.  For any other address, this property
          will be ‘None’.

      -- Attributo: scope_id

          For scoped addresses as defined by RFC 4007(20), this property
          identifies the particular zone of the address’s scope that the
          address belongs to, as a string.  When no scope zone is
          specified, this property will be ‘None’.

      -- Attributo: sixtofour

          For addresses that appear to be 6to4 addresses (starting with
          ‘2002::/16’) as defined by RFC 3056(21), this property will
          report the embedded IPv4 address.  For any other address, this
          property will be ‘None’.

      -- Attributo: teredo

          For addresses that appear to be Teredo addresses (starting
          with ‘2001::/32’) as defined by RFC 4380(22), this property
          will report the embedded ‘(server, client)’ IP address pair.
          For any other address, this property will be ‘None’.

 -- Metodo: IPv6Address.__format__ (fmt)

     Refer to the corresponding method documentation in *note
     IPv4Address: 50d.

     Added in version 3.9.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc3171.html

   (2) https://datatracker.ietf.org/doc/html/rfc2373.html

   (3) 
https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml

   (4) 
https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml

   (5) 
https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml

   (6) 
https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml

   (7) https://datatracker.ietf.org/doc/html/rfc5735.html

   (8) https://datatracker.ietf.org/doc/html/rfc2373.html

   (9) 
https://www.iana.org/assignments/ipv6-address-space/ipv6-address-space.xhtml

   (10) 
https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml

   (11) https://datatracker.ietf.org/doc/html/rfc3879.html

   (12) https://datatracker.ietf.org/doc/html/rfc3330.html

   (13) https://datatracker.ietf.org/doc/html/rfc2373.html

   (14) https://datatracker.ietf.org/doc/html/rfc3927.html

   (15) https://datatracker.ietf.org/doc/html/rfc4291.html

   (16) https://datatracker.ietf.org/doc/html/rfc4291.html

   (17) https://datatracker.ietf.org/doc/html/rfc4007.html

   (18) https://datatracker.ietf.org/doc/html/rfc3879.html

   (19) https://datatracker.ietf.org/doc/html/rfc4193.html

   (20) https://datatracker.ietf.org/doc/html/rfc4007.html

   (21) https://datatracker.ietf.org/doc/html/rfc3056.html

   (22) https://datatracker.ietf.org/doc/html/rfc4380.html


File: python.info,  Node: Conversion to Strings and Integers,  Next: Operators<2>,  Prev: Address objects,  Up: IP Addresses

5.22.23.4 Conversion to Strings and Integers
............................................

To interoperate with networking interfaces such as the socket module,
addresses must be converted to strings or integers.  This is handled
using the *note str(): 169. and *note int(): 19b. builtin functions:

     >>> str(ipaddress.IPv4Address('192.168.0.1'))
     '192.168.0.1'
     >>> int(ipaddress.IPv4Address('192.168.0.1'))
     3232235521
     >>> str(ipaddress.IPv6Address('::1'))
     '::1'
     >>> int(ipaddress.IPv6Address('::1'))
     1

Note that IPv6 scoped addresses are converted to integers without scope
zone ID.


File: python.info,  Node: Operators<2>,  Prev: Conversion to Strings and Integers,  Up: IP Addresses

5.22.23.5 Operators
...................

Address objects support some operators.  Unless stated otherwise,
operators can only be applied between compatible objects (i.e.  IPv4
with IPv4, IPv6 with IPv6).

* Menu:

* Comparison operators::
* Arithmetic operators::


File: python.info,  Node: Comparison operators,  Next: Arithmetic operators,  Up: Operators<2>

5.22.23.6 Comparison operators
..............................

Address objects can be compared with the usual set of comparison
operators.  Same IPv6 addresses with different scope zone IDs are not
equal.  Some examples:

     >>> IPv4Address('127.0.0.2') > IPv4Address('127.0.0.1')
     True
     >>> IPv4Address('127.0.0.2') == IPv4Address('127.0.0.1')
     False
     >>> IPv4Address('127.0.0.2') != IPv4Address('127.0.0.1')
     True
     >>> IPv6Address('fe80::1234') == IPv6Address('fe80::1234%1')
     False
     >>> IPv6Address('fe80::1234%1') != IPv6Address('fe80::1234%2')
     True


File: python.info,  Node: Arithmetic operators,  Prev: Comparison operators,  Up: Operators<2>

5.22.23.7 Arithmetic operators
..............................

Integers can be added to or subtracted from address objects.  Some
examples:

     >>> IPv4Address('127.0.0.2') + 3
     IPv4Address('127.0.0.5')
     >>> IPv4Address('127.0.0.2') - 3
     IPv4Address('126.255.255.255')
     >>> IPv4Address('255.255.255.255') + 1
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     ipaddress.AddressValueError: 4294967296 (>= 2**32) is not permitted as an IPv4 address


File: python.info,  Node: IP Network definitions,  Next: Interface objects,  Prev: IP Addresses,  Up: ipaddress — IPv4/IPv6 manipulation library

5.22.23.8 IP Network definitions
................................

The *note IPv4Network: 50f. and *note IPv6Network: 510. objects provide
a mechanism for defining and inspecting IP network definitions.  A
network definition consists of a 'mask' and a 'network address', and as
such defines a range of IP addresses that equal the network address when
masked (binary AND) with the mask.  For example, a network definition
with the mask ‘255.255.255.0’ and the network address ‘192.168.1.0’
consists of IP addresses in the inclusive range ‘192.168.1.0’ to
‘192.168.1.255’.

* Menu:

* Prefix, net mask and host mask: Prefix net mask and host mask.
* Network objects::
* Operators: Operators<3>.


File: python.info,  Node: Prefix net mask and host mask,  Next: Network objects,  Up: IP Network definitions

5.22.23.9 Prefix, net mask and host mask
........................................

There are several equivalent ways to specify IP network masks.  A
'prefix' ‘/<nbits>’ is a notation that denotes how many high-order bits
are set in the network mask.  A 'net mask' is an IP address with some
number of high-order bits set.  Thus the prefix ‘/24’ is equivalent to
the net mask ‘255.255.255.0’ in IPv4, or ‘ffff:ff00::’ in IPv6.  In
addition, a 'host mask' is the logical inverse of a 'net mask', and is
sometimes used (for example in Cisco access control lists) to denote a
network mask.  The host mask equivalent to ‘/24’ in IPv4 is ‘0.0.0.255’.


File: python.info,  Node: Network objects,  Next: Operators<3>,  Prev: Prefix net mask and host mask,  Up: IP Network definitions

5.22.23.10 Network objects
..........................

All attributes implemented by address objects are implemented by network
objects as well.  In addition, network objects implement additional
attributes.  All of these are common between *note IPv4Network: 50f. and
*note IPv6Network: 510, so to avoid duplication they are only documented
for *note IPv4Network: 50f.  Network objects are *note hashable: 825, so
they can be used as keys in dictionaries.

 -- Classe: ipaddress.IPv4Network (address, strict=True)

     Construct an IPv4 network definition.  'address' can be one of the
     following:

       1. A string consisting of an IP address and an optional mask,
          separated by a slash (‘/’).  The IP address is the network
          address, and the mask can be either a single number, which
          means it’s a 'prefix', or a string representation of an IPv4
          address.  If it’s the latter, the mask is interpreted as a
          'net mask' if it starts with a non-zero field, or as a 'host
          mask' if it starts with a zero field, with the single
          exception of an all-zero mask which is treated as a 'net
          mask'.  If no mask is provided, it’s considered to be ‘/32’.

          For example, the following 'address' specifications are
          equivalent: ‘192.168.1.0/24’, ‘192.168.1.0/255.255.255.0’ and
          ‘192.168.1.0/0.0.0.255’.

       2. An integer that fits into 32 bits.  This is equivalent to a
          single-address network, with the network address being
          'address' and the mask being ‘/32’.

       3. An integer packed into a *note bytes: 192. object of length 4,
          big-endian.  The interpretation is similar to an integer
          'address'.

       4. A two-tuple of an address description and a netmask, where the
          address description is either a string, a 32-bits integer, a
          4-bytes packed integer, or an existing *note IPv4Address: 50d.
          object; and the netmask is either an integer representing the
          prefix length (e.g.  ‘24’) or a string representing the prefix
          mask (e.g.  ‘255.255.255.0’).

     An *note AddressValueError: 41b6. is raised if 'address' is not a
     valid IPv4 address.  A *note NetmaskValueError: 41d7. is raised if
     the mask is not valid for an IPv4 address.

     If 'strict' is ‘True’ and host bits are set in the supplied
     address, then *note ValueError: 2ec. is raised.  Otherwise, the
     host bits are masked out to determine the appropriate network
     address.

     Unless stated otherwise, all network methods accepting other
     network/address objects will raise *note TypeError: 198. if the
     argument’s IP version is incompatible to ‘self’.

     Cambiato nella versione 3.5: Added the two-tuple form for the
     'address' constructor parameter.

      -- Attributo: version

      -- Attributo: max_prefixlen

          Refer to the corresponding attribute documentation in *note
          IPv4Address: 50d.

      -- Attributo: is_multicast

      -- Attributo: is_private

      -- Attributo: is_unspecified

      -- Attributo: is_reserved

      -- Attributo: is_loopback

      -- Attributo: is_link_local

          These attributes are true for the network as a whole if they
          are true for both the network address and the broadcast
          address.

      -- Attributo: network_address

          The network address for the network.  The network address and
          the prefix length together uniquely define a network.

      -- Attributo: broadcast_address

          The broadcast address for the network.  Packets sent to the
          broadcast address should be received by every host on the
          network.

      -- Attributo: hostmask

          The host mask, as an *note IPv4Address: 50d. object.

      -- Attributo: netmask

          The net mask, as an *note IPv4Address: 50d. object.

      -- Attributo: with_prefixlen

      -- Attributo: compressed

      -- Attributo: exploded

          A string representation of the network, with the mask in
          prefix notation.

          ‘with_prefixlen’ and ‘compressed’ are always the same as
          ‘str(network)’.  ‘exploded’ uses the exploded form the network
          address.

      -- Attributo: with_netmask

          A string representation of the network, with the mask in net
          mask notation.

      -- Attributo: with_hostmask

          A string representation of the network, with the mask in host
          mask notation.

      -- Attributo: num_addresses

          The total number of addresses in the network.

      -- Attributo: prefixlen

          Length of the network prefix, in bits.

      -- Metodo: hosts ()

          Returns an iterator over the usable hosts in the network.  The
          usable hosts are all the IP addresses that belong to the
          network, except the network address itself and the network
          broadcast address.  For networks with a mask length of 31, the
          network address and network broadcast address are also
          included in the result.  Networks with a mask of 32 will
          return a list containing the single host address.

               >>> list(ip_network('192.0.2.0/29').hosts())
               [IPv4Address('192.0.2.1'), IPv4Address('192.0.2.2'),
                IPv4Address('192.0.2.3'), IPv4Address('192.0.2.4'),
                IPv4Address('192.0.2.5'), IPv4Address('192.0.2.6')]
               >>> list(ip_network('192.0.2.0/31').hosts())
               [IPv4Address('192.0.2.0'), IPv4Address('192.0.2.1')]
               >>> list(ip_network('192.0.2.1/32').hosts())
               [IPv4Address('192.0.2.1')]

      -- Metodo: overlaps (other)

          ‘True’ if this network is partly or wholly contained in
          'other' or 'other' is wholly contained in this network.

      -- Metodo: address_exclude (network)

          Computes the network definitions resulting from removing the
          given 'network' from this one.  Returns an iterator of network
          objects.  Raises *note ValueError: 2ec. if 'network' is not
          completely contained in this network.

               >>> n1 = ip_network('192.0.2.0/28')
               >>> n2 = ip_network('192.0.2.1/32')
               >>> list(n1.address_exclude(n2))
               [IPv4Network('192.0.2.8/29'), IPv4Network('192.0.2.4/30'),
                IPv4Network('192.0.2.2/31'), IPv4Network('192.0.2.0/32')]

      -- Metodo: subnets (prefixlen_diff=1, new_prefix=None)

          The subnets that join to make the current network definition,
          depending on the argument values.  'prefixlen_diff' is the
          amount our prefix length should be increased by.  'new_prefix'
          is the desired new prefix of the subnets; it must be larger
          than our prefix.  One and only one of 'prefixlen_diff' and
          'new_prefix' must be set.  Returns an iterator of network
          objects.

               >>> list(ip_network('192.0.2.0/24').subnets())
               [IPv4Network('192.0.2.0/25'), IPv4Network('192.0.2.128/25')]
               >>> list(ip_network('192.0.2.0/24').subnets(prefixlen_diff=2))
               [IPv4Network('192.0.2.0/26'), IPv4Network('192.0.2.64/26'),
                IPv4Network('192.0.2.128/26'), IPv4Network('192.0.2.192/26')]
               >>> list(ip_network('192.0.2.0/24').subnets(new_prefix=26))
               [IPv4Network('192.0.2.0/26'), IPv4Network('192.0.2.64/26'),
                IPv4Network('192.0.2.128/26'), IPv4Network('192.0.2.192/26')]
               >>> list(ip_network('192.0.2.0/24').subnets(new_prefix=23))
               Traceback (most recent call last):
                 File "<stdin>", line 1, in <module>
                   raise ValueError('new prefix must be longer')
               ValueError: new prefix must be longer
               >>> list(ip_network('192.0.2.0/24').subnets(new_prefix=25))
               [IPv4Network('192.0.2.0/25'), IPv4Network('192.0.2.128/25')]

      -- Metodo: supernet (prefixlen_diff=1, new_prefix=None)

          The supernet containing this network definition, depending on
          the argument values.  'prefixlen_diff' is the amount our
          prefix length should be decreased by.  'new_prefix' is the
          desired new prefix of the supernet; it must be smaller than
          our prefix.  One and only one of 'prefixlen_diff' and
          'new_prefix' must be set.  Returns a single network object.

               >>> ip_network('192.0.2.0/24').supernet()
               IPv4Network('192.0.2.0/23')
               >>> ip_network('192.0.2.0/24').supernet(prefixlen_diff=2)
               IPv4Network('192.0.0.0/22')
               >>> ip_network('192.0.2.0/24').supernet(new_prefix=20)
               IPv4Network('192.0.0.0/20')

      -- Metodo: subnet_of (other)

          Return ‘True’ if this network is a subnet of 'other'.

               >>> a = ip_network('192.168.1.0/24')
               >>> b = ip_network('192.168.1.128/30')
               >>> b.subnet_of(a)
               True

          Added in version 3.7.

      -- Metodo: supernet_of (other)

          Return ‘True’ if this network is a supernet of 'other'.

               >>> a = ip_network('192.168.1.0/24')
               >>> b = ip_network('192.168.1.128/30')
               >>> a.supernet_of(b)
               True

          Added in version 3.7.

      -- Metodo: compare_networks (other)

          Compare this network to 'other'.  In this comparison only the
          network addresses are considered; host bits aren’t.  Returns
          either ‘-1’, ‘0’ or ‘1’.

               >>> ip_network('192.0.2.1/32').compare_networks(ip_network('192.0.2.2/32'))
               -1
               >>> ip_network('192.0.2.1/32').compare_networks(ip_network('192.0.2.0/32'))
               1
               >>> ip_network('192.0.2.1/32').compare_networks(ip_network('192.0.2.1/32'))
               0

          Deprecato dalla versione 3.7: It uses the same ordering and
          comparison algorithm as «<», «==», and «>»

 -- Classe: ipaddress.IPv6Network (address, strict=True)

     Construct an IPv6 network definition.  'address' can be one of the
     following:

       1. A string consisting of an IP address and an optional prefix
          length, separated by a slash (‘/’).  The IP address is the
          network address, and the prefix length must be a single
          number, the 'prefix'.  If no prefix length is provided, it’s
          considered to be ‘/128’.

          Note that currently expanded netmasks are not supported.  That
          means ‘2001:db00::0/24’ is a valid argument while
          ‘2001:db00::0/ffff:ff00::’ is not.

       2. An integer that fits into 128 bits.  This is equivalent to a
          single-address network, with the network address being
          'address' and the mask being ‘/128’.

       3. An integer packed into a *note bytes: 192. object of length
          16, big-endian.  The interpretation is similar to an integer
          'address'.

       4. A two-tuple of an address description and a netmask, where the
          address description is either a string, a 128-bits integer, a
          16-bytes packed integer, or an existing *note IPv6Address:
          50e. object; and the netmask is an integer representing the
          prefix length.

     An *note AddressValueError: 41b6. is raised if 'address' is not a
     valid IPv6 address.  A *note NetmaskValueError: 41d7. is raised if
     the mask is not valid for an IPv6 address.

     If 'strict' is ‘True’ and host bits are set in the supplied
     address, then *note ValueError: 2ec. is raised.  Otherwise, the
     host bits are masked out to determine the appropriate network
     address.

     Cambiato nella versione 3.5: Added the two-tuple form for the
     'address' constructor parameter.

      -- Attributo: version

      -- Attributo: max_prefixlen

      -- Attributo: is_multicast

      -- Attributo: is_private

      -- Attributo: is_unspecified

      -- Attributo: is_reserved

      -- Attributo: is_loopback

      -- Attributo: is_link_local

      -- Attributo: network_address

      -- Attributo: broadcast_address

      -- Attributo: hostmask

      -- Attributo: netmask

      -- Attributo: with_prefixlen

      -- Attributo: compressed

      -- Attributo: exploded

      -- Attributo: with_netmask

      -- Attributo: with_hostmask

      -- Attributo: num_addresses

      -- Attributo: prefixlen

      -- Metodo: hosts ()

          Returns an iterator over the usable hosts in the network.  The
          usable hosts are all the IP addresses that belong to the
          network, except the Subnet-Router anycast address.  For
          networks with a mask length of 127, the Subnet-Router anycast
          address is also included in the result.  Networks with a mask
          of 128 will return a list containing the single host address.

      -- Metodo: overlaps (other)

      -- Metodo: address_exclude (network)

      -- Metodo: subnets (prefixlen_diff=1, new_prefix=None)

      -- Metodo: supernet (prefixlen_diff=1, new_prefix=None)

      -- Metodo: subnet_of (other)

      -- Metodo: supernet_of (other)

      -- Metodo: compare_networks (other)

          Refer to the corresponding attribute documentation in *note
          IPv4Network: 50f.

      -- Attributo: is_site_local

          This attribute is true for the network as a whole if it is
          true for both the network address and the broadcast address.


File: python.info,  Node: Operators<3>,  Prev: Network objects,  Up: IP Network definitions

5.22.23.11 Operators
....................

Network objects support some operators.  Unless stated otherwise,
operators can only be applied between compatible objects (i.e.  IPv4
with IPv4, IPv6 with IPv6).

* Menu:

* Logical operators::
* Iteration::
* Networks as containers of addresses::


File: python.info,  Node: Logical operators,  Next: Iteration,  Up: Operators<3>

5.22.23.12 Logical operators
............................

Network objects can be compared with the usual set of logical operators.
Network objects are ordered first by network address, then by net mask.


File: python.info,  Node: Iteration,  Next: Networks as containers of addresses,  Prev: Logical operators,  Up: Operators<3>

5.22.23.13 Iteration
....................

Network objects can be iterated to list all the addresses belonging to
the network.  For iteration, 'all' hosts are returned, including
unusable hosts (for usable hosts, use the *note hosts(): 1796. method).
An example:

     >>> for addr in IPv4Network('192.0.2.0/28'):
     ...     addr
     ...
     IPv4Address('192.0.2.0')
     IPv4Address('192.0.2.1')
     IPv4Address('192.0.2.2')
     IPv4Address('192.0.2.3')
     IPv4Address('192.0.2.4')
     IPv4Address('192.0.2.5')
     IPv4Address('192.0.2.6')
     IPv4Address('192.0.2.7')
     IPv4Address('192.0.2.8')
     IPv4Address('192.0.2.9')
     IPv4Address('192.0.2.10')
     IPv4Address('192.0.2.11')
     IPv4Address('192.0.2.12')
     IPv4Address('192.0.2.13')
     IPv4Address('192.0.2.14')
     IPv4Address('192.0.2.15')


File: python.info,  Node: Networks as containers of addresses,  Prev: Iteration,  Up: Operators<3>

5.22.23.14 Networks as containers of addresses
..............................................

Network objects can act as containers of addresses.  Some examples:

     >>> IPv4Network('192.0.2.0/28')[0]
     IPv4Address('192.0.2.0')
     >>> IPv4Network('192.0.2.0/28')[15]
     IPv4Address('192.0.2.15')
     >>> IPv4Address('192.0.2.6') in IPv4Network('192.0.2.0/28')
     True
     >>> IPv4Address('192.0.3.6') in IPv4Network('192.0.2.0/28')
     False


File: python.info,  Node: Interface objects,  Next: Other Module Level Functions,  Prev: IP Network definitions,  Up: ipaddress — IPv4/IPv6 manipulation library

5.22.23.15 Interface objects
............................

Interface objects are *note hashable: 825, so they can be used as keys
in dictionaries.

 -- Classe: ipaddress.IPv4Interface (address)

     Construct an IPv4 interface.  The meaning of 'address' is as in the
     constructor of *note IPv4Network: 50f, except that arbitrary host
     addresses are always accepted.

     *note IPv4Interface: 1b81. is a subclass of *note IPv4Address: 50d,
     so it inherits all the attributes from that class.  In addition,
     the following attributes are available:

      -- Attributo: ip

          The address (*note IPv4Address: 50d.) without network
          information.

               >>> interface = IPv4Interface('192.0.2.5/24')
               >>> interface.ip
               IPv4Address('192.0.2.5')

      -- Attributo: network

          The network (*note IPv4Network: 50f.) this interface belongs
          to.

               >>> interface = IPv4Interface('192.0.2.5/24')
               >>> interface.network
               IPv4Network('192.0.2.0/24')

      -- Attributo: with_prefixlen

          A string representation of the interface with the mask in
          prefix notation.

               >>> interface = IPv4Interface('192.0.2.5/24')
               >>> interface.with_prefixlen
               '192.0.2.5/24'

      -- Attributo: with_netmask

          A string representation of the interface with the network as a
          net mask.

               >>> interface = IPv4Interface('192.0.2.5/24')
               >>> interface.with_netmask
               '192.0.2.5/255.255.255.0'

      -- Attributo: with_hostmask

          A string representation of the interface with the network as a
          host mask.

               >>> interface = IPv4Interface('192.0.2.5/24')
               >>> interface.with_hostmask
               '192.0.2.5/0.0.0.255'

 -- Classe: ipaddress.IPv6Interface (address)

     Construct an IPv6 interface.  The meaning of 'address' is as in the
     constructor of *note IPv6Network: 510, except that arbitrary host
     addresses are always accepted.

     *note IPv6Interface: 1b82. is a subclass of *note IPv6Address: 50e,
     so it inherits all the attributes from that class.  In addition,
     the following attributes are available:

      -- Attributo: ip

      -- Attributo: network

      -- Attributo: with_prefixlen

      -- Attributo: with_netmask

      -- Attributo: with_hostmask

          Refer to the corresponding attribute documentation in *note
          IPv4Interface: 1b81.

* Menu:

* Operators: Operators<4>.


File: python.info,  Node: Operators<4>,  Up: Interface objects

5.22.23.16 Operators
....................

Interface objects support some operators.  Unless stated otherwise,
operators can only be applied between compatible objects (i.e.  IPv4
with IPv4, IPv6 with IPv6).

* Menu:

* Logical operators: Logical operators<2>.


File: python.info,  Node: Logical operators<2>,  Up: Operators<4>

5.22.23.17 Logical operators
............................

Interface objects can be compared with the usual set of logical
operators.

For equality comparison (‘==’ and ‘!=’), both the IP address and network
must be the same for the objects to be equal.  An interface will not
compare equal to any address or network object.

For ordering (‘<’, ‘>’, etc) the rules are different.  Interface and
address objects with the same IP version can be compared, and the
address objects will always sort before the interface objects.  Two
interface objects are first compared by their networks and, if those are
the same, then by their IP addresses.


File: python.info,  Node: Other Module Level Functions,  Next: Custom Exceptions,  Prev: Interface objects,  Up: ipaddress — IPv4/IPv6 manipulation library

5.22.23.18 Other Module Level Functions
.......................................

The module also provides the following module level functions:

 -- Funzione: ipaddress.v4_int_to_packed (address)

     Represent an address as 4 packed bytes in network (big-endian)
     order.  'address' is an integer representation of an IPv4 IP
     address.  A *note ValueError: 2ec. is raised if the integer is
     negative or too large to be an IPv4 IP address.

          >>> ipaddress.ip_address(3221225985)
          IPv4Address('192.0.2.1')
          >>> ipaddress.v4_int_to_packed(3221225985)
          b'\xc0\x00\x02\x01'

 -- Funzione: ipaddress.v6_int_to_packed (address)

     Represent an address as 16 packed bytes in network (big-endian)
     order.  'address' is an integer representation of an IPv6 IP
     address.  A *note ValueError: 2ec. is raised if the integer is
     negative or too large to be an IPv6 IP address.

 -- Funzione: ipaddress.summarize_address_range (first, last)

     Return an iterator of the summarized network range given the first
     and last IP addresses.  'first' is the first *note IPv4Address:
     50d. or *note IPv6Address: 50e. in the range and 'last' is the last
     *note IPv4Address: 50d. or *note IPv6Address: 50e. in the range.  A
     *note TypeError: 198. is raised if 'first' or 'last' are not IP
     addresses or are not of the same version.  A *note ValueError: 2ec.
     is raised if 'last' is not greater than 'first' or if 'first'
     address version is not 4 or 6.

          >>> [ipaddr for ipaddr in ipaddress.summarize_address_range(
          ...    ipaddress.IPv4Address('192.0.2.0'),
          ...    ipaddress.IPv4Address('192.0.2.130'))]
          [IPv4Network('192.0.2.0/25'), IPv4Network('192.0.2.128/31'), IPv4Network('192.0.2.130/32')]

 -- Funzione: ipaddress.collapse_addresses (addresses)

     Return an iterator of the collapsed *note IPv4Network: 50f. or
     *note IPv6Network: 510. objects.  'addresses' is an *note iterable:
     142f. of *note IPv4Network: 50f. or *note IPv6Network: 510.
     objects.  A *note TypeError: 198. is raised if 'addresses' contains
     mixed version objects.

          >>> [ipaddr for ipaddr in
          ... ipaddress.collapse_addresses([ipaddress.IPv4Network('192.0.2.0/25'),
          ... ipaddress.IPv4Network('192.0.2.128/25')])]
          [IPv4Network('192.0.2.0/24')]

 -- Funzione: ipaddress.get_mixed_type_key (obj)

     Return a key suitable for sorting between networks and addresses.
     Address and Network objects are not sortable by default; they’re
     fundamentally different, so the expression:

          IPv4Address('192.0.2.0') <= IPv4Network('192.0.2.0/24')

     doesn’t make sense.  There are some times however, where you may
     wish to have *note ipaddress: 84. sort these anyway.  If you need
     to do this, you can use this function as the 'key' argument to
     *note sorted(): dc9.

     'obj' is either a network or address object.


File: python.info,  Node: Custom Exceptions,  Prev: Other Module Level Functions,  Up: ipaddress — IPv4/IPv6 manipulation library

5.22.23.19 Custom Exceptions
............................

To support more specific error reporting from class constructors, the
module defines the following exceptions:

 -- Eccezione: ipaddress.AddressValueError (ValueError)

     Any value error related to the address.

 -- Eccezione: ipaddress.NetmaskValueError (ValueError)

     Any value error related to the net mask.


File: python.info,  Node: Multimedia Services,  Next: Internationalization,  Prev: Internet Protocols and Support,  Up: The Python Standard Library

5.23 Multimedia Services
========================

The modules described in this chapter implement various algorithms or
interfaces that are mainly useful for multimedia applications.  They are
available at the discretion of the installation.  Here’s an overview:

* Menu:

* wave — Read and write WAV files::
* colorsys — Conversions between color systems::


File: python.info,  Node: wave — Read and write WAV files,  Next: colorsys — Conversions between color systems,  Up: Multimedia Services

5.23.1 ‘wave’ — Read and write WAV files
----------------------------------------

'Source code:' Lib/wave.py(1)

__________________________________________________________________

The *note wave: 119. module provides a convenient interface to the
Waveform Audio «WAVE» (or «WAV») file format.  Only uncompressed PCM
encoded wave files are supported.

Cambiato nella versione 3.12: Support for ‘WAVE_FORMAT_EXTENSIBLE’
headers was added, provided that the extended format is
‘KSDATAFORMAT_SUBTYPE_PCM’.

The *note wave: 119. module defines the following function and
exception:

 -- Funzione: wave.open (file, mode=None)

     If 'file' is a string, open the file by that name, otherwise treat
     it as a file-like object.  'mode' can be:

     ‘'rb'’

          Read only mode.

     ‘'wb'’

          Write only mode.

     Note that it does not allow read/write WAV files.

     A 'mode' of ‘'rb'’ returns a *note Wave_read: 336. object, while a
     'mode' of ‘'wb'’ returns a *note Wave_write: 337. object.  If
     'mode' is omitted and a file-like object is passed as 'file',
     ‘file.mode’ is used as the default value for 'mode'.

     If you pass in a file-like object, the wave object will not close
     it when its ‘close()’ method is called; it is the caller’s
     responsibility to close the file object.

     The *note open(): b47. function may be used in a *note with: 186.
     statement.  When the ‘with’ block completes, the *note
     Wave_read.close(): 4227. or *note Wave_write.close(): 4228. method
     is called.

     Cambiato nella versione 3.4: Added support for unseekable files.

 -- Eccezione: wave.Error

     An error raised when something is impossible because it violates
     the WAV specification or hits an implementation deficiency.

* Menu:

* Wave_read Objects::
* Wave_write Objects::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/wave.py


File: python.info,  Node: Wave_read Objects,  Next: Wave_write Objects,  Up: wave — Read and write WAV files

5.23.1.1 Wave_read Objects
..........................

 -- Classe: wave.Wave_read

     Read a WAV file.

     Wave_read objects, as returned by *note open(): b47, have the
     following methods:

      -- Metodo: close ()

          Close the stream if it was opened by *note wave: 119, and make
          the instance unusable.  This is called automatically on object
          collection.

      -- Metodo: getnchannels ()

          Returns number of audio channels (‘1’ for mono, ‘2’ for
          stereo).

      -- Metodo: getsampwidth ()

          Returns sample width in bytes.

      -- Metodo: getframerate ()

          Returns sampling frequency.

      -- Metodo: getnframes ()

          Returns number of audio frames.

      -- Metodo: getcomptype ()

          Returns compression type (‘'NONE'’ is the only supported
          type).

      -- Metodo: getcompname ()

          Human-readable version of *note getcomptype(): 4230.  Usually
          ‘'not compressed'’ parallels ‘'NONE'’.

      -- Metodo: getparams ()

          Returns a *note namedtuple(): 4e1. ‘(nchannels, sampwidth,
          framerate, nframes, comptype, compname)’, equivalent to output
          of the ‘get*()’ methods.

      -- Metodo: readframes (n)

          Reads and returns at most 'n' frames of audio, as a *note
          bytes: 192. object.

      -- Metodo: rewind ()

          Rewind the file pointer to the beginning of the audio stream.

     The following two methods are defined for compatibility with the
     old ‘aifc’ module, and don’t do anything interesting.

      -- Metodo: getmarkers ()

          Returns ‘None’.

          Deprecated since version 3.13, will be removed in version
          3.15: The method only existed for compatibility with the
          ‘aifc’ module which has been removed in Python 3.13.

      -- Metodo: getmark (id)

          Raise an error.

          Deprecated since version 3.13, will be removed in version
          3.15: The method only existed for compatibility with the
          ‘aifc’ module which has been removed in Python 3.13.

     The following two methods define a term «position» which is
     compatible between them, and is otherwise implementation dependent.

      -- Metodo: setpos (pos)

          Set the file pointer to the specified position.

      -- Metodo: tell ()

          Return current file pointer position.


File: python.info,  Node: Wave_write Objects,  Prev: Wave_read Objects,  Up: wave — Read and write WAV files

5.23.1.2 Wave_write Objects
...........................

 -- Classe: wave.Wave_write

     Write a WAV file.

     Wave_write objects, as returned by *note open(): b47.

     For seekable output streams, the ‘wave’ header will automatically
     be updated to reflect the number of frames actually written.  For
     unseekable streams, the 'nframes' value must be accurate when the
     first frame data is written.  An accurate 'nframes' value can be
     achieved either by calling *note setnframes(): 4237. or *note
     setparams(): 4238. with the number of frames that will be written
     before *note close(): 4228. is called and then using *note
     writeframesraw(): 11ee. to write the frame data, or by calling
     *note writeframes(): 11ef. with all of the frame data to be
     written.  In the latter case *note writeframes(): 11ef. will
     calculate the number of frames in the data and set 'nframes'
     accordingly before writing the frame data.

     Cambiato nella versione 3.4: Added support for unseekable files.

     Wave_write objects have the following methods:

      -- Metodo: close ()

          Make sure 'nframes' is correct, and close the file if it was
          opened by *note wave: 119.  This method is called upon object
          collection.  It will raise an exception if the output stream
          is not seekable and 'nframes' does not match the number of
          frames actually written.

      -- Metodo: setnchannels (n)

          Set the number of channels.

      -- Metodo: setsampwidth (n)

          Set the sample width to 'n' bytes.

      -- Metodo: setframerate (n)

          Set the frame rate to 'n'.

          Cambiato nella versione 3.2: A non-integral input to this
          method is rounded to the nearest integer.

      -- Metodo: setnframes (n)

          Set the number of frames to 'n'.  This will be changed later
          if the number of frames actually written is different (this
          update attempt will raise an error if the output stream is not
          seekable).

      -- Metodo: setcomptype (type, name)

          Set the compression type and description.  At the moment, only
          compression type ‘NONE’ is supported, meaning no compression.

      -- Metodo: setparams (tuple)

          The 'tuple' should be ‘(nchannels, sampwidth, framerate,
          nframes, comptype, compname)’, with values valid for the
          ‘set*()’ methods.  Sets all parameters.

      -- Metodo: tell ()

          Return current position in the file, with the same disclaimer
          for the *note Wave_read.tell(): 4235. and *note
          Wave_read.setpos(): 4234. methods.

      -- Metodo: writeframesraw (data)

          Write audio frames, without correcting 'nframes'.

          Cambiato nella versione 3.4: Any *note bytes-like object: 193.
          is now accepted.

      -- Metodo: writeframes (data)

          Write audio frames and make sure 'nframes' is correct.  It
          will raise an error if the output stream is not seekable and
          the total number of frames that have been written after 'data'
          has been written does not match the previously set value for
          'nframes'.

          Cambiato nella versione 3.4: Any *note bytes-like object: 193.
          is now accepted.

          Note that it is invalid to set any parameters after calling
          *note writeframes(): 11ef. or *note writeframesraw(): 11ee,
          and any attempt to do so will raise *note wave.Error: 4229.


File: python.info,  Node: colorsys — Conversions between color systems,  Prev: wave — Read and write WAV files,  Up: Multimedia Services

5.23.2 ‘colorsys’ — Conversions between color systems
-----------------------------------------------------

'Source code:' Lib/colorsys.py(1)

__________________________________________________________________

The *note colorsys: 20. module defines bidirectional conversions of
color values between colors expressed in the RGB (Red Green Blue) color
space used in computer monitors and three other coordinate systems: YIQ,
HLS (Hue Lightness Saturation) and HSV (Hue Saturation Value).
Coordinates in all of these color spaces are floating-point values.  In
the YIQ space, the Y coordinate is between 0 and 1, but the I and Q
coordinates can be positive or negative.  In all other spaces, the
coordinates are all between 0 and 1.

Vedi anche
..........

More information about color spaces can be found at
‘https://poynton.ca/ColorFAQ.html’ and
‘https://www.cambridgeincolour.com/tutorials/color-spaces.htm’.

The *note colorsys: 20. module defines the following functions:

 -- Funzione: colorsys.rgb_to_yiq (r, g, b)

     Convert the color from RGB coordinates to YIQ coordinates.

 -- Funzione: colorsys.yiq_to_rgb (y, i, q)

     Convert the color from YIQ coordinates to RGB coordinates.

 -- Funzione: colorsys.rgb_to_hls (r, g, b)

     Convert the color from RGB coordinates to HLS coordinates.

 -- Funzione: colorsys.hls_to_rgb (h, l, s)

     Convert the color from HLS coordinates to RGB coordinates.

 -- Funzione: colorsys.rgb_to_hsv (r, g, b)

     Convert the color from RGB coordinates to HSV coordinates.

 -- Funzione: colorsys.hsv_to_rgb (h, s, v)

     Convert the color from HSV coordinates to RGB coordinates.

Example:

     >>> import colorsys
     >>> colorsys.rgb_to_hsv(0.2, 0.4, 0.4)
     (0.5, 0.5, 0.4)
     >>> colorsys.hsv_to_rgb(0.5, 0.5, 0.4)
     (0.2, 0.4, 0.4)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/colorsys.py


File: python.info,  Node: Internationalization,  Next: Graphical user interfaces with Tk,  Prev: Multimedia Services,  Up: The Python Standard Library

5.24 Internationalization
=========================

The modules described in this chapter help you write software that is
independent of language and locale by providing mechanisms for selecting
a language to be used in program messages or by tailoring output to
match local conventions.

The list of modules described in this chapter is:

* Menu:

* gettext — Multilingual internationalization services::
* locale — Internationalization services::


File: python.info,  Node: gettext — Multilingual internationalization services,  Next: locale — Internationalization services,  Up: Internationalization

5.24.1 ‘gettext’ — Multilingual internationalization services
-------------------------------------------------------------

'Source code:' Lib/gettext.py(1)

__________________________________________________________________

The *note gettext: 67. module provides internationalization (I18N) and
localization (L10N) services for your Python modules and applications.
It supports both the GNU ‘gettext’ message catalog API and a higher
level, class-based API that may be more appropriate for Python files.
The interface described below allows you to write your module and
application messages in one natural language, and provide a catalog of
translated messages for running under different natural languages.

Some hints on localizing your Python modules and applications are also
given.

* Menu:

* GNU gettext API::
* Class-based API::
* Internationalizing your programs and modules::
* Acknowledgements: Acknowledgements<9>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/gettext.py


File: python.info,  Node: GNU gettext API,  Next: Class-based API,  Up: gettext — Multilingual internationalization services

5.24.1.1 GNU ‘gettext’ API
..........................

The *note gettext: 67. module defines the following API, which is very
similar to the GNU ‘gettext’ API. If you use this API you will affect
the translation of your entire application globally.  Often this is what
you want if your application is monolingual, with the choice of language
dependent on the locale of your user.  If you are localizing a Python
module, or if your application needs to switch languages on the fly, you
probably want to use the class-based API instead.

 -- Funzione: gettext.bindtextdomain (domain, localedir=None)

     Bind the 'domain' to the locale directory 'localedir'.  More
     concretely, *note gettext: 67. will look for binary ‘.mo’ files for
     the given domain using the path (on Unix):
     ‘`localedir'/`language'/LC_MESSAGES/`domain'.mo’, where 'language'
     is searched for in the environment variables ‘LANGUAGE’, ‘LC_ALL’,
     ‘LC_MESSAGES’, and ‘LANG’ respectively.

     If 'localedir' is omitted or ‘None’, then the current binding for
     'domain' is returned.  (1)

 -- Funzione: gettext.textdomain (domain=None)

     Change or query the current global domain.  If 'domain' is ‘None’,
     then the current global domain is returned, otherwise the global
     domain is set to 'domain', which is returned.

 -- Funzione: gettext.gettext (message)

     Return the localized translation of 'message', based on the current
     global domain, language, and locale directory.  This function is
     usually aliased as ‘_()’ in the local namespace (see examples
     below).

 -- Funzione: gettext.dgettext (domain, message)

     Like *note gettext(): 1670, but look the message up in the
     specified 'domain'.

 -- Funzione: gettext.ngettext (singular, plural, n)

     Like *note gettext(): 1670, but consider plural forms.  If a
     translation is found, apply the plural formula to 'n', and return
     the resulting message (some languages have more than two plural
     forms).  If no translation is found, return 'singular' if 'n' is 1;
     return 'plural' otherwise.

     The Plural formula is taken from the catalog header.  It is a C or
     Python expression that has a free variable 'n'; the expression
     evaluates to the index of the plural in the catalog.  See the GNU
     gettext documentation(2) for the precise syntax to be used in ‘.po’
     files and the formulas for a variety of languages.

 -- Funzione: gettext.dngettext (domain, singular, plural, n)

     Like *note ngettext(): 4250, but look the message up in the
     specified 'domain'.

 -- Funzione: gettext.pgettext (context, message)

 -- Funzione: gettext.dpgettext (domain, context, message)

 -- Funzione: gettext.npgettext (context, singular, plural, n)

 -- Funzione: gettext.dnpgettext (domain, context, singular, plural, n)

     Similar to the corresponding functions without the ‘p’ in the
     prefix (that is, *note gettext(): 67, *note dgettext(): 424f, *note
     ngettext(): 4250, *note dngettext(): 4251.), but the translation is
     restricted to the given message 'context'.

     Added in version 3.8.

Note that GNU ‘gettext’ also defines a ‘dcgettext()’ method, but this
was deemed not useful and so it is currently unimplemented.

Here’s an example of typical usage for this API:

     import gettext
     gettext.bindtextdomain('myapplication', '/path/to/my/language/directory')
     gettext.textdomain('myapplication')
     _ = gettext.gettext
     # ...
     print(_('This is a translatable string.'))

   ---------- Footnotes ----------

   (1) The default locale directory is system dependent; for example, on
Red Hat Linux it is ‘/usr/share/locale’, but on Solaris it is
‘/usr/lib/locale’.  The ‘gettext’ module does not try to support these
system dependent defaults; instead its default is
‘`sys.base_prefix'/share/locale’ (see *note sys.base_prefix: 3e6.).  For
this reason, it is always best to call *note bindtextdomain(): 424d.
with an explicit absolute path at the start of your application.

   (2) https://www.gnu.org/software/gettext/manual/gettext.html


File: python.info,  Node: Class-based API,  Next: Internationalizing your programs and modules,  Prev: GNU gettext API,  Up: gettext — Multilingual internationalization services

5.24.1.2 Class-based API
........................

The class-based API of the *note gettext: 67. module gives you more
flexibility and greater convenience than the GNU ‘gettext’ API. It is
the recommended way of localizing your Python applications and modules.
‘gettext’ defines a *note GNUTranslations: 4256. class which implements
the parsing of GNU ‘.mo’ format files, and has methods for returning
strings.  Instances of this class can also install themselves in the
built-in namespace as the function ‘_()’.

 -- Funzione: gettext.find (domain, localedir=None, languages=None,
          all=False)

     This function implements the standard ‘.mo’ file search algorithm.
     It takes a 'domain', identical to what *note textdomain(): 424e.
     takes.  Optional 'localedir' is as in *note bindtextdomain(): 424d.
     Optional 'languages' is a list of strings, where each string is a
     language code.

     If 'localedir' is not given, then the default system locale
     directory is used.  (1)  If 'languages' is not given, then the
     following environment variables are searched: ‘LANGUAGE’, ‘LC_ALL’,
     ‘LC_MESSAGES’, and ‘LANG’.  The first one returning a non-empty
     value is used for the 'languages' variable.  The environment
     variables should contain a colon separated list of languages, which
     will be split on the colon to produce the expected list of language
     code strings.

     *note find(): 4257. then expands and normalizes the languages, and
     then iterates through them, searching for an existing file built of
     these components:

     ‘`localedir'/`language'/LC_MESSAGES/`domain'.mo’

     The first such file name that exists is returned by *note find():
     4257.  If no such file is found, then ‘None’ is returned.  If 'all'
     is given, it returns a list of all file names, in the order in
     which they appear in the languages list or the environment
     variables.

 -- Funzione: gettext.translation (domain, localedir=None,
          languages=None, class_=None, fallback=False)

     Return a ‘*Translations’ instance based on the 'domain',
     'localedir', and 'languages', which are first passed to *note
     find(): 4257. to get a list of the associated ‘.mo’ file paths.
     Instances with identical ‘.mo’ file names are cached.  The actual
     class instantiated is 'class_' if provided, otherwise *note
     GNUTranslations: 4256.  The class’s constructor must take a single
     *note file object: 13cb. argument.

     If multiple files are found, later files are used as fallbacks for
     earlier ones.  To allow setting the fallback, *note copy.copy():
     758. is used to clone each translation object from the cache; the
     actual instance data is still shared with the cache.

     If no ‘.mo’ file is found, this function raises *note OSError: 2c0.
     if 'fallback' is false (which is the default), and returns a *note
     NullTranslations: 4258. instance if 'fallback' is true.

     Cambiato nella versione 3.3: *note IOError: 1255. used to be
     raised, it is now an alias of *note OSError: 2c0.

     Cambiato nella versione 3.11: 'codeset' parameter is removed.

 -- Funzione: gettext.install (domain, localedir=None, *, names=None)

     This installs the function ‘_()’ in Python’s builtins namespace,
     based on 'domain' and 'localedir' which are passed to the function
     *note translation(): c6f.

     For the 'names' parameter, please see the description of the
     translation object’s *note install(): 4259. method.

     As seen below, you usually mark the strings in your application
     that are candidates for translation, by wrapping them in a call to
     the ‘_()’ function, like this:

          print(_('This string will be translated.'))

     For convenience, you want the ‘_()’ function to be installed in
     Python’s builtins namespace, so it is easily accessible in all
     modules of your application.

     Cambiato nella versione 3.11: 'names' is now a keyword-only
     parameter.

* Menu:

* The NullTranslations class::
* The GNUTranslations class::
* Solaris message catalog support::
* The Catalog constructor::

   ---------- Footnotes ----------

   (1) See the footnote for *note bindtextdomain(): 424d. above.


File: python.info,  Node: The NullTranslations class,  Next: The GNUTranslations class,  Up: Class-based API

5.24.1.3 The ‘NullTranslations’ class
.....................................

Translation classes are what actually implement the translation of
original source file message strings to translated message strings.  The
base class used by all translation classes is *note NullTranslations:
4258.; this provides the basic interface you can use to write your own
specialized translation classes.  Here are the methods of
‘NullTranslations’:

 -- Classe: gettext.NullTranslations (fp=None)

     Takes an optional *note file object: 13cb. 'fp', which is ignored
     by the base class.  Initializes «protected» instance variables
     '_info' and '_charset' which are set by derived classes, as well as
     '_fallback', which is set through *note add_fallback(): 425b.  It
     then calls ‘self._parse(fp)’ if 'fp' is not ‘None’.

      -- Metodo: _parse (fp)

          No-op in the base class, this method takes file object 'fp',
          and reads the data from the file, initializing its message
          catalog.  If you have an unsupported message catalog file
          format, you should override this method to parse your format.

      -- Metodo: add_fallback (fallback)

          Add 'fallback' as the fallback object for the current
          translation object.  A translation object should consult the
          fallback if it cannot provide a translation for a given
          message.

      -- Metodo: gettext (message)

          If a fallback has been set, forward ‘gettext()’ to the
          fallback.  Otherwise, return 'message'.  Overridden in derived
          classes.

      -- Metodo: ngettext (singular, plural, n)

          If a fallback has been set, forward ‘ngettext()’ to the
          fallback.  Otherwise, return 'singular' if 'n' is 1; return
          'plural' otherwise.  Overridden in derived classes.

      -- Metodo: pgettext (context, message)

          If a fallback has been set, forward *note pgettext(): bea. to
          the fallback.  Otherwise, return the translated message.
          Overridden in derived classes.

          Added in version 3.8.

      -- Metodo: npgettext (context, singular, plural, n)

          If a fallback has been set, forward *note npgettext(): 4253.
          to the fallback.  Otherwise, return the translated message.
          Overridden in derived classes.

          Added in version 3.8.

      -- Metodo: info ()

          Return a dictionary containing the metadata found in the
          message catalog file.

      -- Metodo: charset ()

          Return the encoding of the message catalog file.

      -- Metodo: install (names=None)

          This method installs *note gettext(): 425d. into the built-in
          namespace, binding it to ‘_’.

          If the 'names' parameter is given, it must be a sequence
          containing the names of functions you want to install in the
          builtins namespace in addition to ‘_()’.  Supported names are
          ‘'gettext'’, ‘'ngettext'’, ‘'pgettext'’, and ‘'npgettext'’.

          Note that this is only one way, albeit the most convenient
          way, to make the ‘_()’ function available to your application.
          Because it affects the entire application globally, and
          specifically the built-in namespace, localized modules should
          never install ‘_()’.  Instead, they should use this code to
          make ‘_()’ available to their module:

               import gettext
               t = gettext.translation('mymodule', ...)
               _ = t.gettext

          This puts ‘_()’ only in the module’s global namespace and so
          only affects calls within this module.

          Cambiato nella versione 3.8: Added ‘'pgettext'’ and
          ‘'npgettext'’.


File: python.info,  Node: The GNUTranslations class,  Next: Solaris message catalog support,  Prev: The NullTranslations class,  Up: Class-based API

5.24.1.4 The ‘GNUTranslations’ class
....................................

The ‘gettext’ module provides one additional class derived from *note
NullTranslations: 4258.: *note GNUTranslations: 4256.  This class
overrides ‘_parse()’ to enable reading GNU ‘gettext’ format ‘.mo’ files
in both big-endian and little-endian format.

*note GNUTranslations: 4256. parses optional metadata out of the
translation catalog.  It is convention with GNU ‘gettext’ to include
metadata as the translation for the empty string.  This metadata is in
RFC 822(1)-style ‘key: value’ pairs, and should contain the
‘Project-Id-Version’ key.  If the key ‘Content-Type’ is found, then the
‘charset’ property is used to initialize the «protected» ‘_charset’
instance variable, defaulting to ‘None’ if not found.  If the charset
encoding is specified, then all message ids and message strings read
from the catalog are converted to Unicode using this encoding, else
ASCII is assumed.

Since message ids are read as Unicode strings too, all ‘*gettext()’
methods will assume message ids as Unicode strings, not byte strings.

The entire set of key/value pairs are placed into a dictionary and set
as the «protected» ‘_info’ instance variable.

If the ‘.mo’ file’s magic number is invalid, the major version number is
unexpected, or if other problems occur while reading the file,
instantiating a *note GNUTranslations: 4256. class can raise *note
OSError: 2c0.

 -- Classe: gettext.GNUTranslations

     The following methods are overridden from the base class
     implementation:

      -- Metodo: gettext (message)

          Look up the 'message' id in the catalog and return the
          corresponding message string, as a Unicode string.  If there
          is no entry in the catalog for the 'message' id, and a
          fallback has been set, the look up is forwarded to the
          fallback’s *note gettext(): 425d. method.  Otherwise, the
          'message' id is returned.

      -- Metodo: ngettext (singular, plural, n)

          Do a plural-forms lookup of a message id.  'singular' is used
          as the message id for purposes of lookup in the catalog, while
          'n' is used to determine which plural form to use.  The
          returned message string is a Unicode string.

          If the message id is not found in the catalog, and a fallback
          is specified, the request is forwarded to the fallback’s *note
          ngettext(): 425e. method.  Otherwise, when 'n' is 1 'singular'
          is returned, and 'plural' is returned in all other cases.

          Here is an example:

               n = len(os.listdir('.'))
               cat = GNUTranslations(somefile)
               message = cat.ngettext(
                   'There is %(num)d file in this directory',
                   'There are %(num)d files in this directory',
                   n) % {'num': n}

      -- Metodo: pgettext (context, message)

          Look up the 'context' and 'message' id in the catalog and
          return the corresponding message string, as a Unicode string.
          If there is no entry in the catalog for the 'message' id and
          'context', and a fallback has been set, the look up is
          forwarded to the fallback’s *note pgettext(): bea. method.
          Otherwise, the 'message' id is returned.

          Added in version 3.8.

      -- Metodo: npgettext (context, singular, plural, n)

          Do a plural-forms lookup of a message id.  'singular' is used
          as the message id for purposes of lookup in the catalog, while
          'n' is used to determine which plural form to use.

          If the message id for 'context' is not found in the catalog,
          and a fallback is specified, the request is forwarded to the
          fallback’s *note npgettext(): 4253. method.  Otherwise, when
          'n' is 1 'singular' is returned, and 'plural' is returned in
          all other cases.

          Added in version 3.8.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc822.html


File: python.info,  Node: Solaris message catalog support,  Next: The Catalog constructor,  Prev: The GNUTranslations class,  Up: Class-based API

5.24.1.5 Solaris message catalog support
........................................

The Solaris operating system defines its own binary ‘.mo’ file format,
but since no documentation can be found on this format, it is not
supported at this time.


File: python.info,  Node: The Catalog constructor,  Prev: Solaris message catalog support,  Up: Class-based API

5.24.1.6 The Catalog constructor
................................

GNOME uses a version of the *note gettext: 67. module by James
Henstridge, but this version has a slightly different API. Its
documented usage was:

     import gettext
     cat = gettext.Catalog(domain, localedir)
     _ = cat.gettext
     print(_('hello world'))

For compatibility with this older module, the function ‘Catalog()’ is an
alias for the *note translation(): c6f. function described above.

One difference between this module and Henstridge’s: his catalog objects
supported access through a mapping API, but this appears to be unused
and so is not currently supported.


File: python.info,  Node: Internationalizing your programs and modules,  Next: Acknowledgements<9>,  Prev: Class-based API,  Up: gettext — Multilingual internationalization services

5.24.1.7 Internationalizing your programs and modules
.....................................................

Internationalization (I18N) refers to the operation by which a program
is made aware of multiple languages.  Localization (L10N) refers to the
adaptation of your program, once internationalized, to the local
language and cultural habits.  In order to provide multilingual messages
for your Python programs, you need to take the following steps:

  1. prepare your program or module by specially marking translatable
     strings

  2. run a suite of tools over your marked files to generate raw
     messages catalogs

  3. create language-specific translations of the message catalogs

  4. use the *note gettext: 67. module so that message strings are
     properly translated

In order to prepare your code for I18N, you need to look at all the
strings in your files.  Any string that needs to be translated should be
marked by wrapping it in ‘_('...')’ — that is, a call to the function
*note _: 67.  For example:

     filename = 'mylog.txt'
     message = _('writing a log message')
     with open(filename, 'w') as fp:
         fp.write(message)

In this example, the string ‘'writing a log message'’ is marked as a
candidate for translation, while the strings ‘'mylog.txt'’ and ‘'w'’ are
not.

There are a few tools to extract the strings meant for translation.  The
original GNU ‘gettext’ only supported C or C++ source code but its
extended version ‘xgettext’ scans code written in a number of languages,
including Python, to find strings marked as translatable.  Babel(1) is a
Python internationalization library that includes a ‘pybabel’ script to
extract and compile message catalogs.  François Pinard’s program called
‘xpot’ does a similar job and is available as part of his po-utils
package(2).

(Python also includes pure-Python versions of these programs, called
‘pygettext.py’ and ‘msgfmt.py’; some Python distributions will install
them for you.  ‘pygettext.py’ is similar to ‘xgettext’, but only
understands Python source code and cannot handle other programming
languages such as C or C++.  ‘pygettext.py’ supports a command-line
interface similar to ‘xgettext’; for details on its use, run
‘pygettext.py --help’.  ‘msgfmt.py’ is binary compatible with GNU
‘msgfmt’.  With these two programs, you may not need the GNU ‘gettext’
package to internationalize your Python applications.)

‘xgettext’, ‘pygettext’, and similar tools generate ‘.po’ files that are
message catalogs.  They are structured human-readable files that contain
every marked string in the source code, along with a placeholder for the
translated versions of these strings.

Copies of these ‘.po’ files are then handed over to the individual human
translators who write translations for every supported natural language.
They send back the completed language-specific versions as a
‘<language-name>.po’ file that’s compiled into a machine-readable ‘.mo’
binary catalog file using the ‘msgfmt’ program.  The ‘.mo’ files are
used by the *note gettext: 67. module for the actual translation
processing at run-time.

How you use the *note gettext: 67. module in your code depends on
whether you are internationalizing a single module or your entire
application.  The next two sections will discuss each case.

* Menu:

* Localizing your module::
* Localizing your application::
* Changing languages on the fly::
* Deferred translations::

   ---------- Footnotes ----------

   (1) https://babel.pocoo.org/

   (2) https://github.com/pinard/po-utils


File: python.info,  Node: Localizing your module,  Next: Localizing your application,  Up: Internationalizing your programs and modules

5.24.1.8 Localizing your module
...............................

If you are localizing your module, you must take care not to make global
changes, e.g.  to the built-in namespace.  You should not use the GNU
‘gettext’ API but instead the class-based API.

Let’s say your module is called «spam» and the module’s various natural
language translation ‘.mo’ files reside in ‘/usr/share/locale’ in GNU
‘gettext’ format.  Here’s what you would put at the top of your module:

     import gettext
     t = gettext.translation('spam', '/usr/share/locale')
     _ = t.gettext


File: python.info,  Node: Localizing your application,  Next: Changing languages on the fly,  Prev: Localizing your module,  Up: Internationalizing your programs and modules

5.24.1.9 Localizing your application
....................................

If you are localizing your application, you can install the ‘_()’
function globally into the built-in namespace, usually in the main
driver file of your application.  This will let all your
application-specific files just use ‘_('...')’ without having to
explicitly install it in each file.

In the simple case then, you need only add the following bit of code to
the main driver file of your application:

     import gettext
     gettext.install('myapplication')

If you need to set the locale directory, you can pass it into the *note
install(): c70. function:

     import gettext
     gettext.install('myapplication', '/usr/share/locale')


File: python.info,  Node: Changing languages on the fly,  Next: Deferred translations,  Prev: Localizing your application,  Up: Internationalizing your programs and modules

5.24.1.10 Changing languages on the fly
.......................................

If your program needs to support many languages at the same time, you
may want to create multiple translation instances and then switch
between them explicitly, like so:

     import gettext

     lang1 = gettext.translation('myapplication', languages=['en'])
     lang2 = gettext.translation('myapplication', languages=['fr'])
     lang3 = gettext.translation('myapplication', languages=['de'])

     # start by using language1
     lang1.install()

     # ... time goes by, user selects language 2
     lang2.install()

     # ... more time goes by, user selects language 3
     lang3.install()


File: python.info,  Node: Deferred translations,  Prev: Changing languages on the fly,  Up: Internationalizing your programs and modules

5.24.1.11 Deferred translations
...............................

In most coding situations, strings are translated where they are coded.
Occasionally however, you need to mark strings for translation, but
defer actual translation until later.  A classic example is:

     animals = ['mollusk',
                'albatross',
                'rat',
                'penguin',
                'python', ]
     # ...
     for a in animals:
         print(a)

Here, you want to mark the strings in the ‘animals’ list as being
translatable, but you don’t actually want to translate them until they
are printed.

Here is one way you can handle this situation:

     def _(message): return message

     animals = [_('mollusk'),
                _('albatross'),
                _('rat'),
                _('penguin'),
                _('python'), ]

     del _

     # ...
     for a in animals:
         print(_(a))

This works because the dummy definition of ‘_()’ simply returns the
string unchanged.  And this dummy definition will temporarily override
any definition of ‘_()’ in the built-in namespace (until the *note del:
1b07. command).  Take care, though if you have a previous definition of
‘_()’ in the local namespace.

Note that the second use of ‘_()’ will not identify «a» as being
translatable to the ‘gettext’ program, because the parameter is not a
string literal.

Another way to handle this is with the following example:

     def N_(message): return message

     animals = [N_('mollusk'),
                N_('albatross'),
                N_('rat'),
                N_('penguin'),
                N_('python'), ]

     # ...
     for a in animals:
         print(_(a))

In this case, you are marking translatable strings with the function
‘N_()’, which won’t conflict with any definition of ‘_()’.  However, you
will need to teach your message extraction program to look for
translatable strings marked with ‘N_()’.  ‘xgettext’, ‘pygettext’,
‘pybabel extract’, and ‘xpot’ all support this through the use of the
‘-k’ command-line switch.  The choice of ‘N_()’ here is totally
arbitrary; it could have just as easily been
‘MarkThisStringForTranslation()’.


File: python.info,  Node: Acknowledgements<9>,  Prev: Internationalizing your programs and modules,  Up: gettext — Multilingual internationalization services

5.24.1.12 Acknowledgements
..........................

The following people contributed code, feedback, design suggestions,
previous implementations, and valuable experience to the creation of
this module:

   * Peter Funk

   * James Henstridge

   * Juan David Ibáñez Palomar

   * Marc-André Lemburg

   * Martin von Löwis

   * François Pinard

   * Barry Warsaw

   * Gustavo Niemeyer


File: python.info,  Node: locale — Internationalization services,  Prev: gettext — Multilingual internationalization services,  Up: Internationalization

5.24.2 ‘locale’ — Internationalization services
-----------------------------------------------

'Source code:' Lib/locale.py(1)

__________________________________________________________________

The *note locale: 8a. module opens access to the POSIX locale database
and functionality.  The POSIX locale mechanism allows programmers to
deal with certain cultural issues in an application, without requiring
the programmer to know all the specifics of each country where the
software is executed.

The *note locale: 8a. module is implemented on top of the ‘_locale’
module, which in turn uses an ANSI C locale implementation if available.

The *note locale: 8a. module defines the following exception and
functions:

 -- Eccezione: locale.Error

     Exception raised when the locale passed to *note setlocale(): 328.
     is not recognized.

 -- Funzione: locale.setlocale (category, locale=None)

     If 'locale' is given and not ‘None’, *note setlocale(): 328.
     modifies the locale setting for the 'category'.  The available
     categories are listed in the data description below.  'locale' may
     be a *note string: 4274, or a pair, language code and encoding.  An
     empty string specifies the user’s default settings.  If the
     modification of the locale fails, the exception *note Error: 4273.
     is raised.  If successful, the new locale setting is returned.

     If 'locale' is a pair, it is converted to a locale name using the
     locale aliasing engine.  The language code has the same format as a
     *note locale name: 4274, but without encoding and ‘@’-modifier.
     The language code and encoding can be ‘None’.

     If 'locale' is omitted or ‘None’, the current setting for
     'category' is returned.

     Example:

          >>> import locale
          >>> loc = locale.setlocale(locale.LC_ALL)  # get current locale
          # use German locale; name and availability varies with platform
          >>> locale.setlocale(locale.LC_ALL, 'de_DE.UTF-8')
          >>> locale.strcoll('f\xe4n', 'foo')  # compare a string containing an umlaut
          >>> locale.setlocale(locale.LC_ALL, '')   # use user's preferred locale
          >>> locale.setlocale(locale.LC_ALL, 'C')  # use default (C) locale
          >>> locale.setlocale(locale.LC_ALL, loc)  # restore saved locale

     *note setlocale(): 328. is not thread-safe on most systems.
     Applications typically start with a call of:

          import locale
          locale.setlocale(locale.LC_ALL, '')

     This sets the locale for all categories to the user’s default
     setting (typically specified in the ‘LANG’ environment variable).
     If the locale is not changed thereafter, using multithreading
     should not cause problems.

 -- Funzione: locale.localeconv ()

     Returns the database of the local conventions as a dictionary.
     This dictionary has the following strings as keys:

     Category                   Key                                       Meaning
                                                                          
     ----------------------------------------------------------------------------------------------------------
                                                                          
     *note LC_NUMERIC: 4275.    ‘'decimal_point'’                         Decimal point character.
                                                                          
                                                                          
                                ‘'grouping'’                              Sequence of numbers specifying
                                                                          which relative positions the
                                                                          ‘'thousands_sep'’ is expected.  If
                                                                          the sequence is terminated with
                                                                          *note CHAR_MAX: 4276, no further
                                                                          grouping is performed.  If the
                                                                          sequence terminates with a ‘0’,
                                                                          the last group size is repeatedly
                                                                          used.
                                                                          
                                                                          
                                ‘'thousands_sep'’                         Character used between groups.
                                                                          
                                                                          
     *note LC_MONETARY: 4277.   ‘'int_curr_symbol'’                       International currency symbol.
                                                                          
                                                                          
                                ‘'currency_symbol'’                       Local currency symbol.
                                                                          
                                                                          
                                ‘'p_cs_precedes/n_cs_precedes'’           Whether the currency symbol
                                                                          precedes the value (for positive
                                                                          resp.  negative values).
                                                                          
                                                                          
                                ‘'p_sep_by_space/n_sep_by_space'’         Whether the currency symbol is
                                                                          separated from the value by a
                                                                          space (for positive resp.
                                                                          negative values).
                                                                          
                                                                          
                                ‘'mon_decimal_point'’                     Decimal point used for monetary
                                                                          values.
                                                                          
                                                                          
                                ‘'frac_digits'’                           Number of fractional digits used
                                                                          in local formatting of monetary
                                                                          values.
                                                                          
                                                                          
                                ‘'int_frac_digits'’                       Number of fractional digits used
                                                                          in international formatting of
                                                                          monetary values.
                                                                          
                                                                          
                                ‘'mon_thousands_sep'’                     Group separator used for monetary
                                                                          values.
                                                                          
                                                                          
                                ‘'mon_grouping'’                          Equivalent to ‘'grouping'’, used
                                                                          for monetary values.
                                                                          
                                                                          
                                ‘'positive_sign'’                         Symbol used to annotate a positive
                                                                          monetary value.
                                                                          
                                                                          
                                ‘'negative_sign'’                         Symbol used to annotate a negative
                                                                          monetary value.
                                                                          
                                                                          
                                ‘'p_sign_posn/n_sign_posn'’               The position of the sign (for
                                                                          positive resp.  negative values),
                                                                          see below.
                                                                          

     All numeric values can be set to *note CHAR_MAX: 4276. to indicate
     that there is no value specified in this locale.

     The possible values for ‘'p_sign_posn'’ and ‘'n_sign_posn'’ are
     given below.

     Value              Explanation
                        
     -----------------------------------------------------------------
                        
     ‘0’                Currency and value are surrounded by
                        parentheses.
                        
                        
     ‘1’                The sign should precede the value and
                        currency symbol.
                        
                        
     ‘2’                The sign should follow the value and
                        currency symbol.
                        
                        
     ‘3’                The sign should immediately precede the
                        value.
                        
                        
     ‘4’                The sign should immediately follow the
                        value.
                        
                        
     ‘CHAR_MAX’         Nothing is specified in this locale.
                        

     The function temporarily sets the ‘LC_CTYPE’ locale to the
     ‘LC_NUMERIC’ locale or the ‘LC_MONETARY’ locale if locales are
     different and numeric or monetary strings are non-ASCII. This
     temporary change affects other threads.

     Cambiato nella versione 3.7: The function now temporarily sets the
     ‘LC_CTYPE’ locale to the ‘LC_NUMERIC’ locale in some cases.

 -- Funzione: locale.nl_langinfo (option)

     Return some locale-specific information as a string.  This function
     is not available on all systems, and the set of possible options
     might also vary across platforms.  The possible argument values are
     numbers, for which symbolic constants are available in the locale
     module.

     The *note nl_langinfo(): 454. function accepts one of the following
     keys.  Most descriptions are taken from the corresponding
     description in the GNU C library.

      -- Dati: locale.CODESET

          Get a string with the name of the character encoding used in
          the selected locale.

      -- Dati: locale.D_T_FMT

          Get a string that can be used as a format string for *note
          time.strftime(): 13f1. to represent date and time in a
          locale-specific way.

      -- Dati: locale.D_FMT

          Get a string that can be used as a format string for *note
          time.strftime(): 13f1. to represent a date in a
          locale-specific way.

      -- Dati: locale.T_FMT

          Get a string that can be used as a format string for *note
          time.strftime(): 13f1. to represent a time in a
          locale-specific way.

      -- Dati: locale.T_FMT_AMPM

          Get a format string for *note time.strftime(): 13f1. to
          represent time in the am/pm format.

      -- Dati: locale.DAY_1
      -- Dati: locale.DAY_2
      -- Dati: locale.DAY_3
      -- Dati: locale.DAY_4
      -- Dati: locale.DAY_5
      -- Dati: locale.DAY_6
      -- Dati: locale.DAY_7

          Get the name of the n-th day of the week.

               Nota: This follows the US convention of *note DAY_1:
               427d. being Sunday, not the international convention (ISO
               8601) that Monday is the first day of the week.

      -- Dati: locale.ABDAY_1
      -- Dati: locale.ABDAY_2
      -- Dati: locale.ABDAY_3
      -- Dati: locale.ABDAY_4
      -- Dati: locale.ABDAY_5
      -- Dati: locale.ABDAY_6
      -- Dati: locale.ABDAY_7

          Get the abbreviated name of the n-th day of the week.

      -- Dati: locale.MON_1
      -- Dati: locale.MON_2
      -- Dati: locale.MON_3
      -- Dati: locale.MON_4
      -- Dati: locale.MON_5
      -- Dati: locale.MON_6
      -- Dati: locale.MON_7
      -- Dati: locale.MON_8
      -- Dati: locale.MON_9
      -- Dati: locale.MON_10
      -- Dati: locale.MON_11
      -- Dati: locale.MON_12

          Get the name of the n-th month.

      -- Dati: locale.ABMON_1
      -- Dati: locale.ABMON_2
      -- Dati: locale.ABMON_3
      -- Dati: locale.ABMON_4
      -- Dati: locale.ABMON_5
      -- Dati: locale.ABMON_6
      -- Dati: locale.ABMON_7
      -- Dati: locale.ABMON_8
      -- Dati: locale.ABMON_9
      -- Dati: locale.ABMON_10
      -- Dati: locale.ABMON_11
      -- Dati: locale.ABMON_12

          Get the abbreviated name of the n-th month.

      -- Dati: locale.RADIXCHAR

          Get the radix character (decimal dot, decimal comma, etc.).

      -- Dati: locale.THOUSEP

          Get the separator character for thousands (groups of three
          digits).

      -- Dati: locale.YESEXPR

          Get a regular expression that can be used with the regex
          function to recognize a positive response to a yes/no
          question.

      -- Dati: locale.NOEXPR

          Get a regular expression that can be used with the ‘regex(3)’
          function to recognize a negative response to a yes/no
          question.

               Nota: The regular expressions for *note YESEXPR: 42a5.
               and *note NOEXPR: 42a6. use syntax suitable for the
               ‘regex’ function from the C library, which might differ
               from the syntax used in *note re: be.

      -- Dati: locale.CRNCYSTR

          Get the currency symbol, preceded by «-» if the symbol should
          appear before the value, «+» if the symbol should appear after
          the value, or «.» if the symbol should replace the radix
          character.

      -- Dati: locale.ERA

          Get a string which describes how years are counted and
          displayed for each era in a locale.

          Most locales do not define this value.  An example of a locale
          which does define this value is the Japanese one.  In Japan,
          the traditional representation of dates includes the name of
          the era corresponding to the then-emperor’s reign.

          Normally it should not be necessary to use this value
          directly.  Specifying the ‘E’ modifier in their format strings
          causes the *note time.strftime(): 13f1. function to use this
          information.  The format of the returned string is specified
          in 'The Open Group Base Specifications Issue 8', paragraph
          7.3.5.2 LC_TIME C-Language Access(2).

      -- Dati: locale.ERA_D_T_FMT

          Get a format string for *note time.strftime(): 13f1. to
          represent date and time in a locale-specific era-based way.

      -- Dati: locale.ERA_D_FMT

          Get a format string for *note time.strftime(): 13f1. to
          represent a date in a locale-specific era-based way.

      -- Dati: locale.ERA_T_FMT

          Get a format string for *note time.strftime(): 13f1. to
          represent a time in a locale-specific era-based way.

      -- Dati: locale.ALT_DIGITS

          Get a string consisting of up to 100 semicolon-separated
          symbols used to represent the values 0 to 99 in a
          locale-specific way.  In most locales this is an empty string.

     The function temporarily sets the ‘LC_CTYPE’ locale to the locale
     of the category that determines the requested value (‘LC_TIME’,
     ‘LC_NUMERIC’, ‘LC_MONETARY’ or ‘LC_MESSAGES’) if locales are
     different and the resulting string is non-ASCII. This temporary
     change affects other threads.

     Cambiato nella versione 3.14: The function now temporarily sets the
     ‘LC_CTYPE’ locale in some cases.

 -- Funzione: locale.getdefaultlocale ([envvars])

     Tries to determine the default locale settings and returns them as
     a tuple of the form ‘(language code, encoding)’.

     According to POSIX, a program which has not called
     ‘setlocale(LC_ALL, '')’ runs using the portable ‘'C'’ locale.
     Calling ‘setlocale(LC_ALL, '')’ lets it use the default locale as
     defined by the ‘LANG’ variable.  Since we do not want to interfere
     with the current locale setting we thus emulate the behavior in the
     way described above.

     To maintain compatibility with other platforms, not only the ‘LANG’
     variable is tested, but a list of variables given as envvars
     parameter.  The first found to be defined will be used.  'envvars'
     defaults to the search path used in GNU gettext; it must always
     contain the variable name ‘'LANG'’.  The GNU gettext search path
     contains ‘'LC_ALL'’, ‘'LC_CTYPE'’, ‘'LANG'’ and ‘'LANGUAGE'’, in
     that order.

     The language code has the same format as a *note locale name: 4274,
     but without encoding and ‘@’-modifier.  The language code and
     encoding may be ‘None’ if their values cannot be determined.  The
     «C» locale is represented as ‘(None, None)’.

     Deprecated since version 3.11, will be removed in version 3.15.

 -- Funzione: locale.getlocale (category=LC_CTYPE)

     Returns the current setting for the given locale category as a
     tuple containing the language code and encoding.  'category' may be
     one of the ‘LC_*’ values except *note LC_ALL: 42ad.  It defaults to
     *note LC_CTYPE: 42ae.

     The language code has the same format as a *note locale name: 4274,
     but without encoding and ‘@’-modifier.  The language code and
     encoding may be ‘None’ if their values cannot be determined.  The
     «C» locale is represented as ‘(None, None)’.

 -- Funzione: locale.getpreferredencoding (do_setlocale=True)

     Return the *note locale encoding: 54b. used for text data,
     according to user preferences.  User preferences are expressed
     differently on different systems, and might not be available
     programmatically on some systems, so this function only returns a
     guess.

     On some systems, it is necessary to invoke *note setlocale(): 328.
     to obtain the user preferences, so this function is not
     thread-safe.  If invoking setlocale is not necessary or desired,
     'do_setlocale' should be set to ‘False’.

     On Android or if the *note Python UTF-8 Mode: 867. is enabled,
     always return ‘'utf-8'’, the *note locale encoding: 54b. and the
     'do_setlocale' argument are ignored.

     The *note Python preinitialization: 42af. configures the LC_CTYPE
     locale.  See also the *note filesystem encoding and error handler:
     75e.

     Cambiato nella versione 3.7: The function now always returns
     ‘"utf-8"’ on Android or if the *note Python UTF-8 Mode: 867. is
     enabled.

 -- Funzione: locale.getencoding ()

     Get the current *note locale encoding: 54b.:

        * On Android and VxWorks, return ‘"utf-8"’.

        * On Unix, return the encoding of the current *note LC_CTYPE:
          42ae. locale.  Return ‘"utf-8"’ if ‘nl_langinfo(CODESET)’
          returns an empty string: for example, if the current LC_CTYPE
          locale is not supported.

        * On Windows, return the ANSI code page.

     The *note Python preinitialization: 42af. configures the LC_CTYPE
     locale.  See also the *note filesystem encoding and error handler:
     75e.

     This function is similar to *note getpreferredencoding(False): 75d.
     except this function ignores the *note Python UTF-8 Mode: 867.

     Added in version 3.11.

 -- Funzione: locale.normalize (localename)

     Returns a normalized locale code for the given locale name.  The
     returned locale code is formatted for use with *note setlocale():
     328.  If normalization fails, the original name is returned
     unchanged.

     If the given encoding is not known, the function defaults to the
     default encoding for the locale code just like *note setlocale():
     328.

 -- Funzione: locale.strcoll (string1, string2)

     Compares two strings according to the current *note LC_COLLATE:
     42b2. setting.  As any other compare function, returns a negative,
     or a positive value, or ‘0’, depending on whether 'string1'
     collates before or after 'string2' or is equal to it.

 -- Funzione: locale.strxfrm (string)

     Transforms a string to one that can be used in locale-aware
     comparisons.  For example, ‘strxfrm(s1) < strxfrm(s2)’ is
     equivalent to ‘strcoll(s1, s2) < 0’.  This function can be used
     when the same string is compared repeatedly, e.g.  when collating a
     sequence of strings.

 -- Funzione: locale.format_string (format, val, grouping=False,
          monetary=False)

     Formats a number 'val' according to the current *note LC_NUMERIC:
     4275. setting.  The format follows the conventions of the ‘%’
     operator.  For floating-point values, the decimal point is modified
     if appropriate.  If 'grouping' is ‘True’, also takes the grouping
     into account.

     If 'monetary' is true, the conversion uses monetary thousands
     separator and grouping strings.

     Processes formatting specifiers as in ‘format % val’, but takes the
     current locale settings into account.

     Cambiato nella versione 3.7: The 'monetary' keyword parameter was
     added.

 -- Funzione: locale.currency (val, symbol=True, grouping=False,
          international=False)

     Formats a number 'val' according to the current *note LC_MONETARY:
     4277. settings.

     The returned string includes the currency symbol if 'symbol' is
     true, which is the default.  If 'grouping' is ‘True’ (which is not
     the default), grouping is done with the value.  If 'international'
     is ‘True’ (which is not the default), the international currency
     symbol is used.

          Nota: This function will not work with the “C” locale, so you
          have to set a locale via *note setlocale(): 328. first.

 -- Funzione: locale.str (float)

     Formats a floating-point number using the same format as the
     built-in function ‘str(float)’, but takes the decimal point into
     account.

 -- Funzione: locale.delocalize (string)

     Converts a string into a normalized number string, following the
     *note LC_NUMERIC: 4275. settings.

     Added in version 3.5.

 -- Funzione: locale.localize (string, grouping=False, monetary=False)

     Converts a normalized number string into a formatted string
     following the *note LC_NUMERIC: 4275. settings.

     Added in version 3.10.

 -- Funzione: locale.atof (string, func=float)

     Converts a string to a number, following the *note LC_NUMERIC:
     4275. settings, by calling 'func' on the result of calling *note
     delocalize(): 1028. on 'string'.

 -- Funzione: locale.atoi (string)

     Converts a string to an integer, following the *note LC_NUMERIC:
     4275. conventions.

 -- Dati: locale.LC_CTYPE

     Locale category for the character type functions.  Most
     importantly, this category defines the text encoding, i.e.  how
     bytes are interpreted as Unicode codepoints.  See PEP 538(3) and
     PEP 540(4) for how this variable might be automatically coerced to
     ‘C.UTF-8’ to avoid issues created by invalid settings in containers
     or incompatible settings passed over remote SSH connections.

     Python doesn’t internally use locale-dependent character
     transformation functions from ‘ctype.h’.  Instead, ‘pyctype.h’
     provides locale-independent equivalents like *note Py_TOLOWER:
     1560.

 -- Dati: locale.LC_COLLATE

     Locale category for sorting strings.  The functions *note
     strcoll(): 42b1. and *note strxfrm(): 17a5. of the *note locale:
     8a. module are affected.

 -- Dati: locale.LC_TIME

     Locale category for the formatting of time.  The function *note
     time.strftime(): 13f1. follows these conventions.

 -- Dati: locale.LC_MONETARY

     Locale category for formatting of monetary values.  The available
     options are available from the *note localeconv(): dfa. function.

 -- Dati: locale.LC_MESSAGES

     Locale category for message display.  Python currently does not
     support application specific locale-aware messages.  Messages
     displayed by the operating system, like those returned by *note
     os.strerror(): 3009. might be affected by this category.

     This value may not be available on operating systems not conforming
     to the POSIX standard, most notably Windows.

 -- Dati: locale.LC_NUMERIC

     Locale category for formatting numbers.  The functions *note
     format_string(): 743, *note atoi(): 42b7, *note atof(): 42b6. and
     *note str(): 42b4. of the *note locale: 8a. module are affected by
     that category.  All other numeric formatting operations are not
     affected.

 -- Dati: locale.LC_ALL

     Combination of all locale settings.  If this flag is used when the
     locale is changed, setting the locale for all categories is
     attempted.  If that fails for any category, no category is changed
     at all.  When the locale is retrieved using this flag, a string
     indicating the setting for all categories is returned.  This string
     can be later used to restore the settings.

 -- Dati: locale.CHAR_MAX

     This is a symbolic constant used for different values returned by
     *note localeconv(): dfa.

* Menu:

* Background, details, hints, tips and caveats: Background details hints tips and caveats.
* Locale names::
* For extension writers and programs that embed Python::
* Access to message catalogs::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/locale.py

   (2) 
https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/V1_chap07.html#tag_07_03_05_02

   (3) https://peps.python.org/pep-0538/

   (4) https://peps.python.org/pep-0540/


File: python.info,  Node: Background details hints tips and caveats,  Next: Locale names,  Up: locale — Internationalization services

5.24.2.1 Background, details, hints, tips and caveats
.....................................................

The C standard defines the locale as a program-wide property that may be
relatively expensive to change.  On top of that, some implementations
are broken in such a way that frequent locale changes may cause core
dumps.  This makes the locale somewhat painful to use correctly.

Initially, when a program is started, the locale is the ‘C’ locale, no
matter what the user’s preferred locale is.  There is one exception: the
*note LC_CTYPE: 42ae. category is changed at startup to set the current
locale encoding to the user’s preferred locale encoding.  The program
must explicitly say that it wants the user’s preferred locale settings
for other categories by calling ‘setlocale(LC_ALL, '')’.

It is generally a bad idea to call *note setlocale(): 328. in some
library routine, since as a side effect it affects the entire program.
Saving and restoring it is almost as bad: it is expensive and affects
other threads that happen to run before the settings have been restored.

If, when coding a module for general use, you need a locale independent
version of an operation that is affected by the locale (such as certain
formats used with *note time.strftime(): 13f1.), you will have to find a
way to do it without using the standard library routine.  Even better is
convincing yourself that using locale settings is okay.  Only as a last
resort should you document that your module is not compatible with
non-‘C’ locale settings.

The only way to perform numeric operations according to the locale is to
use the special functions defined by this module: *note atof(): 42b6,
*note atoi(): 42b7, *note format_string(): 743, *note str(): 42b4.

There is no way to perform case conversions and character
classifications according to the locale.  For (Unicode) text strings
these are done according to the character value only, while for byte
strings, the conversions and classifications are done according to the
ASCII value of the byte, and bytes whose high bit is set (i.e.,
non-ASCII bytes) are never converted or considered part of a character
class such as letter or whitespace.


File: python.info,  Node: Locale names,  Next: For extension writers and programs that embed Python,  Prev: Background details hints tips and caveats,  Up: locale — Internationalization services

5.24.2.2 Locale names
.....................

The format of the locale name is platform dependent, and the set of
supported locales can depend on the system configuration.

On Posix platforms, it usually has the format (1):

       language ["_" territory] ["." charset] ["@" modifier]

where 'language' is a two- or three-letter language code from ISO
639(2), 'territory' is a two-letter country or region code from ISO
3166(3), 'charset' is a locale encoding, and 'modifier' is a script
name, a language subtag, a sort order identifier, or other locale
modifier (for example, «latin», «valencia», «stroke» and «euro»).

On Windows, several formats are supported.  (4)  (5)  A subset of IETF
BCP 47(6) tags:

       language ["-" script] ["-" territory] ["." charset]
       language ["-" script] "-" territory "-" modifier

where 'language' and 'territory' have the same meaning as in Posix,
'script' is a four-letter script code from ISO 15924(7), and 'modifier'
is a language subtag, a sort order identifier or custom modifier (for
example, «valencia», «stroke» or «x-python»).  Both hyphen (‘'-'’) and
underscore (‘'_'’) separators are supported.  Only UTF-8 encoding is
allowed for BCP 47 tags.

Windows also supports locale names in the format:

       language ["_" territory] ["." charset]

where 'language' and 'territory' are full names, such as «English» and
«United States», and 'charset' is either a code page number (for
example, «1252») or UTF-8.  Only the underscore separator is supported
in this format.

The «C» locale is supported on all platforms.

   ---------- Footnotes ----------

   (1) IEEE Std 1003.1-2024; 8.2 Internationalization Variables
(https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/V1_chap08.html#tag_08_02)

   (2) https://www.iso.org/iso-639-language-code

   (3) https://www.iso.org/iso-3166-country-codes.html

   (4) UCRT Locale names, Languages, and Country/Region strings
(https://learn.microsoft.com/en-us/cpp/c-runtime-library/locale-names-languages-and-country-region-strings)

   (5) Locale Names
(https://learn.microsoft.com/en-us/windows/win32/intl/locale-names)

   (6) https://www.rfc-editor.org/info/bcp47

   (7) https://www.unicode.org/iso15924/


File: python.info,  Node: For extension writers and programs that embed Python,  Next: Access to message catalogs,  Prev: Locale names,  Up: locale — Internationalization services

5.24.2.3 For extension writers and programs that embed Python
.............................................................

Extension modules should never call *note setlocale(): 328, except to
find out what the current locale is.  But since the return value can
only be used portably to restore it, that is not very useful (except
perhaps to find out whether or not the locale is ‘C’).

When Python code uses the *note locale: 8a. module to change the locale,
this also affects the embedding application.  If the embedding
application doesn’t want this to happen, it should remove the ‘_locale’
extension module (which does all the work) from the table of built-in
modules in the ‘config.c’ file, and make sure that the ‘_locale’ module
is not accessible as a shared library.


File: python.info,  Node: Access to message catalogs,  Prev: For extension writers and programs that embed Python,  Up: locale — Internationalization services

5.24.2.4 Access to message catalogs
...................................

 -- Funzione: locale.gettext (msg)

 -- Funzione: locale.dgettext (domain, msg)

 -- Funzione: locale.dcgettext (domain, msg, category)

 -- Funzione: locale.textdomain (domain)

 -- Funzione: locale.bindtextdomain (domain, dir)

 -- Funzione: locale.bind_textdomain_codeset (domain, codeset)

The locale module exposes the C library’s gettext interface on systems
that provide this interface.  It consists of the functions *note
gettext(): 67, *note dgettext(): 42c1, *note dcgettext(): 42c2, *note
textdomain(): 42c3, *note bindtextdomain(): 42c4, and *note
bind_textdomain_codeset(): 42c5.  These are similar to the same
functions in the *note gettext: 67. module, but use the C library’s
binary format for message catalogs, and the C library’s search
algorithms for locating message catalogs.

Python applications should normally find no need to invoke these
functions, and should use *note gettext: 67. instead.  A known exception
to this rule are applications that link with additional C libraries
which internally invoke C functions ‘gettext’ or ‘dcgettext’.  For these
applications, it may be necessary to bind the text domain, so that the
libraries can properly locate their message catalogs.


File: python.info,  Node: Graphical user interfaces with Tk,  Next: Development Tools,  Prev: Internationalization,  Up: The Python Standard Library

5.25 Graphical user interfaces with Tk
======================================

Tk/Tcl has long been an integral part of Python.  It provides a robust
and platform independent windowing toolkit, that is available to Python
programmers using the *note tkinter: f6. package, and its extension, the
*note tkinter.ttk: ff. module.

The *note tkinter: f6. package is a thin object-oriented layer on top of
Tcl/Tk.  To use *note tkinter: f6, you don’t need to write Tcl code, but
you will need to consult the Tk documentation, and occasionally the Tcl
documentation.  *note tkinter: f6. is a set of wrappers that implement
the Tk widgets as Python classes.

*note tkinter: f6.’s chief virtues are that it is fast, and that it
usually comes bundled with Python.  Although its standard documentation
is weak, good material is available, which includes: references,
tutorials, a book and others.  *note tkinter: f6. is also famous for
having an outdated look and feel, which has been vastly improved in Tk
8.5.  Nevertheless, there are many other GUI libraries that you could be
interested in.  The Python wiki lists several alternative GUI frameworks
and tools(1).

* Menu:

* tkinter — Python interface to Tcl/Tk::
* tkinter.colorchooser — Color choosing dialog: tkinter colorchooser — Color choosing dialog.
* tkinter.font — Tkinter font wrapper: tkinter font — Tkinter font wrapper.
* Tkinter Dialogs::
* tkinter.messagebox — Tkinter message prompts: tkinter messagebox — Tkinter message prompts.
* tkinter.scrolledtext — Scrolled Text Widget: tkinter scrolledtext — Scrolled Text Widget.
* tkinter.dnd — Drag and drop support: tkinter dnd — Drag and drop support.
* tkinter.ttk — Tk themed widgets: tkinter ttk — Tk themed widgets.
* IDLE — Python editor and shell: IDLE — Python editor and shell<2>.
* turtle — Turtle graphics::

   ---------- Footnotes ----------

   (1) https://wiki.python.org/moin/GuiProgramming


File: python.info,  Node: tkinter — Python interface to Tcl/Tk,  Next: tkinter colorchooser — Color choosing dialog,  Up: Graphical user interfaces with Tk

5.25.1 ‘tkinter’ — Python interface to Tcl/Tk
---------------------------------------------

'Source code:' Lib/tkinter/__init__.py(1)

__________________________________________________________________

The *note tkinter: f6. package («Tk interface») is the standard Python
interface to the Tcl/Tk GUI toolkit.  Both Tk and *note tkinter: f6. are
available on most Unix platforms, including macOS, as well as on Windows
systems.

Running ‘python -m tkinter’ from the command line should open a window
demonstrating a simple Tk interface, letting you know that *note
tkinter: f6. is properly installed on your system, and also showing what
version of Tcl/Tk is installed, so you can read the Tcl/Tk documentation
specific to that version.

Tkinter supports a range of Tcl/Tk versions, built either with or
without thread support.  The official Python binary release bundles
Tcl/Tk 8.6 threaded.  See the source code for the *note _tkinter: 3.
module for more information about supported versions.

Tkinter is not a thin wrapper, but adds a fair amount of its own logic
to make the experience more pythonic.  This documentation will
concentrate on these additions and changes, and refer to the official
Tcl/Tk documentation for details that are unchanged.

     Nota: Tcl/Tk 8.5 (2007) introduced a modern set of themed user
     interface components along with a new API to use them.  Both old
     and new APIs are still available.  Most documentation you will find
     online still uses the old API and can be woefully outdated.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

Vedi anche
..........

   * 
     TkDocs(2)

          Extensive tutorial on creating user interfaces with Tkinter.
          Explains key concepts, and illustrates recommended approaches
          using the modern API.

   * 
     Tkinter 8.5 reference: a GUI for Python(3)

          Reference documentation for Tkinter 8.5 detailing available
          classes, methods, and options.

Tcl/Tk Resources:

   * 
     Tk commands(4)

          Comprehensive reference to each of the underlying Tcl/Tk
          commands used by Tkinter.

   * 
     Tcl/Tk Home Page(5)

          Additional documentation, and links to Tcl/Tk core
          development.

Books:

   * 
     Modern Tkinter for Busy Python Developers(6)

          By Mark Roseman.  (ISBN 978-1999149567)

   * 
     Python GUI programming with Tkinter(7)

          By Alan D. Moore.  (ISBN 978-1788835886)

   * 
     Programming Python(8)

          By Mark Lutz; has excellent coverage of Tkinter.  (ISBN
          978-0596158101)

   * 
     Tcl and the Tk Toolkit (2nd edition)(9)

          By John Ousterhout, inventor of Tcl/Tk, and Ken Jones; does
          not cover Tkinter.  (ISBN 978-0321336330)

* Menu:

* Architecture::
* Tkinter Modules::
* Tkinter Life Preserver::
* Threading model::
* Handy Reference::
* File Handlers::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/tkinter/__init__.py

   (2) https://tkdocs.com/

   (3) https://www.tkdocs.com/shipman/

   (4) https://www.tcl.tk/man/tcl8.6/TkCmd/contents.htm

   (5) https://www.tcl.tk

   (6) https://tkdocs.com/book.html

   (7) 
https://www.packtpub.com/en-us/product/python-gui-programming-with-tkinter-9781788835886

   (8) https://learning-python.com/about-pp4e.html

   (9) https://www.amazon.com/exec/obidos/ASIN/032133633X


File: python.info,  Node: Architecture,  Next: Tkinter Modules,  Up: tkinter — Python interface to Tcl/Tk

5.25.1.1 Architecture
.....................

Tcl/Tk is not a single library but rather consists of a few distinct
modules, each with separate functionality and its own official
documentation.  Python’s binary releases also ship an add-on module
together with it.

Tcl

     Tcl is a dynamic interpreted programming language, just like
     Python.  Though it can be used on its own as a general-purpose
     programming language, it is most commonly embedded into C
     applications as a scripting engine or an interface to the Tk
     toolkit.  The Tcl library has a C interface to create and manage
     one or more instances of a Tcl interpreter, run Tcl commands and
     scripts in those instances, and add custom commands implemented in
     either Tcl or C. Each interpreter has an event queue, and there are
     facilities to send events to it and process them.  Unlike Python,
     Tcl’s execution model is designed around cooperative multitasking,
     and Tkinter bridges this difference (see *note Threading model:
     42cd. for details).

Tk

     Tk is a Tcl package(1) implemented in C that adds custom commands
     to create and manipulate GUI widgets.  Each *note Tk: 1994. object
     embeds its own Tcl interpreter instance with Tk loaded into it.
     Tk’s widgets are very customizable, though at the cost of a dated
     appearance.  Tk uses Tcl’s event queue to generate and process GUI
     events.

Ttk

     Themed Tk (Ttk) is a newer family of Tk widgets that provide a much
     better appearance on different platforms than many of the classic
     Tk widgets.  Ttk is distributed as part of Tk, starting with Tk
     version 8.5.  Python bindings are provided in a separate module,
     *note tkinter.ttk: ff.

Internally, Tk and Ttk use facilities of the underlying operating
system, i.e., Xlib on Unix/X11, Cocoa on macOS, GDI on Windows.

When your Python application uses a class in Tkinter, e.g., to create a
widget, the *note tkinter: f6. module first assembles a Tcl/Tk command
string.  It passes that Tcl command string to an internal *note
_tkinter: 3. binary module, which then calls the Tcl interpreter to
evaluate it.  The Tcl interpreter will then call into the Tk and/or Ttk
packages, which will in turn make calls to Xlib, Cocoa, or GDI.

   ---------- Footnotes ----------

   (1) https://wiki.tcl-lang.org/37432


File: python.info,  Node: Tkinter Modules,  Next: Tkinter Life Preserver,  Prev: Architecture,  Up: tkinter — Python interface to Tcl/Tk

5.25.1.2 Tkinter Modules
........................

Support for Tkinter is spread across several modules.  Most applications
will need the main *note tkinter: f6. module, as well as the *note
tkinter.ttk: ff. module, which provides the modern themed widget set and
API:

     from tkinter import *
     from tkinter import ttk

 -- Classe: tkinter.Tk (screenName=None, baseName=None, className='Tk',
          useTk=True, sync=False, use=None)

     Construct a toplevel Tk widget, which is usually the main window of
     an application, and initialize a Tcl interpreter for this widget.
     Each instance has its own associated Tcl interpreter.

     The *note Tk: 1994. class is typically instantiated using all
     default values.  However, the following keyword arguments are
     currently recognized:

     'screenName'

          When given (as a string), sets the ‘DISPLAY’ environment
          variable.  (X11 only)

     'baseName'

          Name of the profile file.  By default, 'baseName' is derived
          from the program name (‘sys.argv[0]’).

     'className'

          Name of the widget class.  Used as a profile file and also as
          the name with which Tcl is invoked ('argv0' in 'interp').

     'useTk'

          If ‘True’, initialize the Tk subsystem.  The *note
          tkinter.Tcl(): 42cf. function sets this to ‘False’.

     'sync'

          If ‘True’, execute all X server commands synchronously, so
          that errors are reported immediately.  Can be used for
          debugging.  (X11 only)

     'use'

          Specifies the 'id' of the window in which to embed the
          application, instead of it being created as an independent
          toplevel window.  'id' must be specified in the same way as
          the value for the -use option for toplevel widgets (that is,
          it has a form like that returned by ‘winfo_id()’).

          Note that on some platforms this will only work correctly if
          'id' refers to a Tk frame or toplevel that has its -container
          option enabled.

     *note Tk: 1994. reads and interprets profile files, named
     ‘.`className'.tcl’ and ‘.`baseName'.tcl’, into the Tcl interpreter
     and calls *note exec(): 4a3. on the contents of ‘.`className'.py’
     and ‘.`baseName'.py’.  The path for the profile files is the ‘HOME’
     environment variable or, if that isn’t defined, then *note
     os.curdir: 2c3d.

      -- Attributo: tk

          The Tk application object created by instantiating *note Tk:
          1994.  This provides access to the Tcl interpreter.  Each
          widget that is attached the same instance of *note Tk: 1994.
          has the same value for its *note tk: 42d0. attribute.

      -- Attributo: master

          The widget object that contains this widget.  For *note Tk:
          1994, the ‘master’ is *note None: 886. because it is the main
          window.  The terms 'master' and 'parent' are similar and
          sometimes used interchangeably as argument names; however,
          calling ‘winfo_parent()’ returns a string of the widget name
          whereas ‘master’ returns the object.  'parent'/'child'
          reflects the tree-like relationship while 'master' (or
          'container')/'content' reflects the container structure.

      -- Attributo: children

          The immediate descendants of this widget as a *note dict: 183.
          with the child widget names as the keys and the child instance
          objects as the values.

 -- Funzione: tkinter.Tcl (screenName=None, baseName=None,
          className='Tk', useTk=False)

     The *note Tcl(): 42cf. function is a factory function which creates
     an object much like that created by the *note Tk: 1994. class,
     except that it does not initialize the Tk subsystem.  This is most
     often useful when driving the Tcl interpreter in an environment
     where one doesn’t want to create extraneous toplevel windows, or
     where one cannot (such as Unix/Linux systems without an X server).
     An object created by the *note Tcl(): 42cf. object can have a
     Toplevel window created (and the Tk subsystem initialized) by
     calling its ‘loadtk()’ method.

The modules that provide Tk support include:

*note tkinter: f6.

     Main Tkinter module.

*note tkinter.colorchooser: f7.

     Dialog to let the user choose a color.

*note tkinter.commondialog: f8.

     Base class for the dialogs defined in the other modules listed
     here.

*note tkinter.filedialog: fa.

     Common dialogs to allow the user to specify a file to open or save.

*note tkinter.font: fb.

     Utilities to help work with fonts.

*note tkinter.messagebox: fc.

     Access to standard Tk dialog boxes.

*note tkinter.scrolledtext: fd.

     Text widget with a vertical scroll bar built in.

*note tkinter.simpledialog: fe.

     Basic dialogs and convenience functions.

*note tkinter.ttk: ff.

     Themed widget set introduced in Tk 8.5, providing modern
     alternatives for many of the classic widgets in the main *note
     tkinter: f6. module.

Additional modules:

*note _tkinter: 3.

     A binary module that contains the low-level interface to Tcl/Tk.
     It is automatically imported by the main *note tkinter: f6. module,
     and should never be used directly by application programmers.  It
     is usually a shared library (or DLL), but might in some cases be
     statically linked with the Python interpreter.

*note idlelib: 77.

     Python’s Integrated Development and Learning Environment (IDLE).
     Based on *note tkinter: f6.

‘tkinter.constants’

     Symbolic constants that can be used in place of strings when
     passing various parameters to Tkinter calls.  Automatically
     imported by the main *note tkinter: f6. module.

*note tkinter.dnd: f9.

     (experimental) Drag-and-drop support for *note tkinter: f6.  This
     will become deprecated when it is replaced with the Tk DND.

*note turtle: 107.

     Turtle graphics in a Tk window.


File: python.info,  Node: Tkinter Life Preserver,  Next: Threading model,  Prev: Tkinter Modules,  Up: tkinter — Python interface to Tcl/Tk

5.25.1.3 Tkinter Life Preserver
...............................

This section is not designed to be an exhaustive tutorial on either Tk
or Tkinter.  For that, refer to one of the external resources noted
earlier.  Instead, this section provides a very quick orientation to
what a Tkinter application looks like, identifies foundational Tk
concepts, and explains how the Tkinter wrapper is structured.

The remainder of this section will help you to identify the classes,
methods, and options you’ll need in your Tkinter application, and where
to find more detailed documentation on them, including in the official
Tcl/Tk reference manual.

* Menu:

* A Hello World Program::
* Important Tk Concepts::
* Understanding How Tkinter Wraps Tcl/Tk::
* How do I…? What option does…?::
* Navigating the Tcl/Tk Reference Manual::


File: python.info,  Node: A Hello World Program,  Next: Important Tk Concepts,  Up: Tkinter Life Preserver

5.25.1.4 A Hello World Program
..............................

We’ll start by walking through a «Hello World» application in Tkinter.
This isn’t the smallest one we could write, but has enough to illustrate
some key concepts you’ll need to know.

     from tkinter import *
     from tkinter import ttk
     root = Tk()
     frm = ttk.Frame(root, padding=10)
     frm.grid()
     ttk.Label(frm, text="Hello World!").grid(column=0, row=0)
     ttk.Button(frm, text="Quit", command=root.destroy).grid(column=1, row=0)
     root.mainloop()

After the imports, the next line creates an instance of the ‘Tk’ class,
which initializes Tk and creates its associated Tcl interpreter.  It
also creates a toplevel window, known as the root window, which serves
as the main window of the application.

The following line creates a frame widget, which in this case will
contain a label and a button we’ll create next.  The frame is fit inside
the root window.

The next line creates a label widget holding a static text string.  The
‘grid()’ method is used to specify the relative layout (position) of the
label within its containing frame widget, similar to how tables in HTML
work.

A button widget is then created, and placed to the right of the label.
When pressed, it will call the ‘destroy()’ method of the root window.

Finally, the ‘mainloop()’ method puts everything on the display, and
responds to user input until the program terminates.


File: python.info,  Node: Important Tk Concepts,  Next: Understanding How Tkinter Wraps Tcl/Tk,  Prev: A Hello World Program,  Up: Tkinter Life Preserver

5.25.1.5 Important Tk Concepts
..............................

Even this simple program illustrates the following key Tk concepts:

widgets

     A Tkinter user interface is made up of individual 'widgets'.  Each
     widget is represented as a Python object, instantiated from classes
     like ‘ttk.Frame’, ‘ttk.Label’, and ‘ttk.Button’.

widget hierarchy

     Widgets are arranged in a 'hierarchy'.  The label and button were
     contained within a frame, which in turn was contained within the
     root window.  When creating each 'child' widget, its 'parent'
     widget is passed as the first argument to the widget constructor.

configuration options

     Widgets have 'configuration options', which modify their appearance
     and behavior, such as the text to display in a label or button.
     Different classes of widgets will have different sets of options.

geometry management

     Widgets aren’t automatically added to the user interface when they
     are created.  A 'geometry manager' like ‘grid’ controls where in
     the user interface they are placed.

event loop

     Tkinter reacts to user input, changes from your program, and even
     refreshes the display only when actively running an 'event loop'.
     If your program isn’t running the event loop, your user interface
     won’t update.


File: python.info,  Node: Understanding How Tkinter Wraps Tcl/Tk,  Next: How do I…? What option does…?,  Prev: Important Tk Concepts,  Up: Tkinter Life Preserver

5.25.1.6 Understanding How Tkinter Wraps Tcl/Tk
...............................................

When your application uses Tkinter’s classes and methods, internally
Tkinter is assembling strings representing Tcl/Tk commands, and
executing those commands in the Tcl interpreter attached to your
application’s ‘Tk’ instance.

Whether it’s trying to navigate reference documentation, trying to find
the right method or option, adapting some existing code, or debugging
your Tkinter application, there are times that it will be useful to
understand what those underlying Tcl/Tk commands look like.

To illustrate, here is the Tcl/Tk equivalent of the main part of the
Tkinter script above.

     ttk::frame .frm -padding 10
     grid .frm
     grid [ttk::label .frm.lbl -text "Hello World!"] -column 0 -row 0
     grid [ttk::button .frm.btn -text "Quit" -command "destroy ."] -column 1 -row 0

Tcl’s syntax is similar to many shell languages, where the first word is
the command to be executed, with arguments to that command following it,
separated by spaces.  Without getting into too many details, notice the
following:

   * The commands used to create widgets (like ‘ttk::frame’) correspond
     to widget classes in Tkinter.

   * Tcl widget options (like ‘-text’) correspond to keyword arguments
     in Tkinter.

   * Widgets are referred to by a 'pathname' in Tcl (like ‘.frm.btn’),
     whereas Tkinter doesn’t use names but object references.

   * A widget’s place in the widget hierarchy is encoded in its
     (hierarchical) pathname, which uses a ‘.’ (dot) as a path
     separator.  The pathname for the root window is just ‘.’ (dot).  In
     Tkinter, the hierarchy is defined not by pathname but by specifying
     the parent widget when creating each child widget.

   * Operations which are implemented as separate 'commands' in Tcl
     (like ‘grid’ or ‘destroy’) are represented as 'methods' on Tkinter
     widget objects.  As you’ll see shortly, at other times Tcl uses
     what appear to be method calls on widget objects, which more
     closely mirror what is used in Tkinter.


File: python.info,  Node: How do I…? What option does…?,  Next: Navigating the Tcl/Tk Reference Manual,  Prev: Understanding How Tkinter Wraps Tcl/Tk,  Up: Tkinter Life Preserver

5.25.1.7 How do I…? What option does…?
......................................

If you’re not sure how to do something in Tkinter, and you can’t
immediately find it in the tutorial or reference documentation you’re
using, there are a few strategies that can be helpful.

First, remember that the details of how individual widgets work may vary
across different versions of both Tkinter and Tcl/Tk.  If you’re
searching documentation, make sure it corresponds to the Python and
Tcl/Tk versions installed on your system.

When searching for how to use an API, it helps to know the exact name of
the class, option, or method that you’re using.  Introspection, either
in an interactive Python shell or with *note print(): 1177, can help you
identify what you need.

To find out what configuration options are available on any widget, call
its ‘configure()’ method, which returns a dictionary containing a
variety of information about each object, including its default and
current values.  Use ‘keys()’ to get just the names of each option.

     btn = ttk.Button(frm, ...)
     print(btn.configure().keys())

As most widgets have many configuration options in common, it can be
useful to find out which are specific to a particular widget class.
Comparing the list of options to that of a simpler widget, like a frame,
is one way to do that.

     print(set(btn.configure().keys()) - set(frm.configure().keys()))

Similarly, you can find the available methods for a widget object using
the standard *note dir(): 845. function.  If you try it, you’ll see
there are over 200 common widget methods, so again identifying those
specific to a widget class is helpful.

     print(dir(btn))
     print(set(dir(btn)) - set(dir(frm)))


File: python.info,  Node: Navigating the Tcl/Tk Reference Manual,  Prev: How do I…? What option does…?,  Up: Tkinter Life Preserver

5.25.1.8 Navigating the Tcl/Tk Reference Manual
...............................................

As noted, the official Tk commands(1) reference manual (man pages) is
often the most accurate description of what specific operations on
widgets do.  Even when you know the name of the option or method that
you need, you may still have a few places to look.

While all operations in Tkinter are implemented as method calls on
widget objects, you’ve seen that many Tcl/Tk operations appear as
commands that take a widget pathname as its first parameter, followed by
optional parameters, e.g.

     destroy .
     grid .frm.btn -column 0 -row 0

Others, however, look more like methods called on a widget object (in
fact, when you create a widget in Tcl/Tk, it creates a Tcl command with
the name of the widget pathname, with the first parameter to that
command being the name of a method to call).

     .frm.btn invoke
     .frm.lbl configure -text "Goodbye"

In the official Tcl/Tk reference documentation, you’ll find most
operations that look like method calls on the man page for a specific
widget (e.g., you’ll find the ‘invoke()’ method on the ttk::button(2)
man page), while functions that take a widget as a parameter often have
their own man page (e.g., grid(3)).

You’ll find many common options and methods in the options(4) or
ttk::widget(5) man pages, while others are found in the man page for a
specific widget class.

You’ll also find that many Tkinter methods have compound names, e.g.,
‘winfo_x()’, ‘winfo_height()’, ‘winfo_viewable()’.  You’d find
documentation for all of these in the winfo(6) man page.

     Nota: Somewhat confusingly, there are also methods on all Tkinter
     widgets that don’t actually operate on the widget, but operate at a
     global scope, independent of any widget.  Examples are methods for
     accessing the clipboard or the system bell.  (They happen to be
     implemented as methods in the base ‘Widget’ class that all Tkinter
     widgets inherit from).

   ---------- Footnotes ----------

   (1) https://www.tcl.tk/man/tcl8.6/TkCmd/contents.htm

   (2) https://www.tcl.tk/man/tcl8.6/TkCmd/ttk_button.htm

   (3) https://www.tcl.tk/man/tcl8.6/TkCmd/grid.htm

   (4) https://www.tcl.tk/man/tcl8.6/TkCmd/options.htm

   (5) https://www.tcl.tk/man/tcl8.6/TkCmd/ttk_widget.htm

   (6) https://www.tcl.tk/man/tcl8.6/TkCmd/winfo.htm


File: python.info,  Node: Threading model,  Next: Handy Reference,  Prev: Tkinter Life Preserver,  Up: tkinter — Python interface to Tcl/Tk

5.25.1.9 Threading model
........................

Python and Tcl/Tk have very different threading models, which *note
tkinter: f6. tries to bridge.  If you use threads, you may need to be
aware of this.

A Python interpreter may have many threads associated with it.  In Tcl,
multiple threads can be created, but each thread has a separate Tcl
interpreter instance associated with it.  Threads can also create more
than one interpreter instance, though each interpreter instance can be
used only by the one thread that created it.

Each ‘Tk’ object created by *note tkinter: f6. contains a Tcl
interpreter.  It also keeps track of which thread created that
interpreter.  Calls to *note tkinter: f6. can be made from any Python
thread.  Internally, if a call comes from a thread other than the one
that created the ‘Tk’ object, an event is posted to the interpreter’s
event queue, and when executed, the result is returned to the calling
Python thread.

Tcl/Tk applications are normally event-driven, meaning that after
initialization, the interpreter runs an event loop (i.e.
‘Tk.mainloop()’) and responds to events.  Because it is single-threaded,
event handlers must respond quickly, otherwise they will block other
events from being processed.  To avoid this, any long-running
computations should not run in an event handler, but are either broken
into smaller pieces using timers, or run in another thread.  This is
different from many GUI toolkits where the GUI runs in a completely
separate thread from all application code including event handlers.

If the Tcl interpreter is not running the event loop and processing
events, any *note tkinter: f6. calls made from threads other than the
one running the Tcl interpreter will fail.

A number of special cases exist:

   * Tcl/Tk libraries can be built so they are not thread-aware.  In
     this case, *note tkinter: f6. calls the library from the
     originating Python thread, even if this is different than the
     thread that created the Tcl interpreter.  A global lock ensures
     only one call occurs at a time.

   * While *note tkinter: f6. allows you to create more than one
     instance of a ‘Tk’ object (with its own interpreter), all
     interpreters that are part of the same thread share a common event
     queue, which gets ugly fast.  In practice, don’t create more than
     one instance of ‘Tk’ at a time.  Otherwise, it’s best to create
     them in separate threads and ensure you’re running a thread-aware
     Tcl/Tk build.

   * Blocking event handlers are not the only way to prevent the Tcl
     interpreter from reentering the event loop.  It is even possible to
     run multiple nested event loops or abandon the event loop entirely.
     If you’re doing anything tricky when it comes to events or threads,
     be aware of these possibilities.

   * There are a few select *note tkinter: f6. functions that presently
     work only when called from the thread that created the Tcl
     interpreter.


File: python.info,  Node: Handy Reference,  Next: File Handlers,  Prev: Threading model,  Up: tkinter — Python interface to Tcl/Tk

5.25.1.10 Handy Reference
.........................

* Menu:

* Setting Options::
* The Packer::
* Packer Options::
* Coupling Widget Variables::
* The Window Manager::
* Tk Option Data Types::
* Bindings and Events::
* The index Parameter::
* Images::


File: python.info,  Node: Setting Options,  Next: The Packer,  Up: Handy Reference

5.25.1.11 Setting Options
.........................

Options control things like the color and border width of a widget.
Options can be set in three ways:

At object creation time, using keyword arguments

          fred = Button(self, fg="red", bg="blue")

After object creation, treating the option name like a dictionary index

          fred["fg"] = "red"
          fred["bg"] = "blue"

Use the config() method to update multiple attrs subsequent to object creation

          fred.config(fg="red", bg="blue")

For a complete explanation of a given option and its behavior, see the
Tk man pages for the widget in question.

Note that the man pages list «STANDARD OPTIONS» and «WIDGET SPECIFIC
OPTIONS» for each widget.  The former is a list of options that are
common to many widgets, the latter are the options that are
idiosyncratic to that particular widget.  The Standard Options are
documented on the ‘options(3)(1)’ man page.

No distinction between standard and widget-specific options is made in
this document.  Some options don’t apply to some kinds of widgets.
Whether a given widget responds to a particular option depends on the
class of the widget; buttons have a ‘command’ option, labels do not.

The options supported by a given widget are listed in that widget’s man
page, or can be queried at runtime by calling the ‘config()’ method
without arguments, or by calling the ‘keys()’ method on that widget.
The return value of these calls is a dictionary whose key is the name of
the option as a string (for example, ‘'relief'’) and whose values are
5-tuples.

Some options, like ‘bg’ are synonyms for common options with long names
(‘bg’ is shorthand for «background»).  Passing the ‘config()’ method the
name of a shorthand option will return a 2-tuple, not 5-tuple.  The
2-tuple passed back will contain the name of the synonym and the «real»
option (such as ‘('bg', 'background')’).

Index       Meaning                               Example
                                                  
---------------------------------------------------------------------
                                                  
0           option name                           ‘'relief'’
                                                  
                                                  
1           option name for database lookup       ‘'relief'’
                                                  
                                                  
2           option class for database lookup      ‘'Relief'’
                                                  
                                                  
3           default value                         ‘'raised'’
                                                  
                                                  
4           current value                         ‘'groove'’
                                                  

Example:

     >>> print(fred.config())
     {'relief': ('relief', 'relief', 'Relief', 'raised', 'groove')}

Of course, the dictionary printed will include all the options available
and their values.  This is meant only as an example.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/options(3)


File: python.info,  Node: The Packer,  Next: Packer Options,  Prev: Setting Options,  Up: Handy Reference

5.25.1.12 The Packer
....................

The packer is one of Tk’s geometry-management mechanisms.  Geometry
managers are used to specify the relative positioning of widgets within
their container.  In contrast to the more cumbersome 'placer' (which is
used less commonly, and we do not cover here), the packer takes
qualitative relationship specification - 'above', 'to the left of',
'filling', etc - and works everything out to determine the exact
placement coordinates for you.

The size of any container widget is determined by the size of the
«content widgets» inside.  The packer is used to control where content
widgets appear inside the container into which they are packed.  You can
pack widgets into frames, and frames into other frames, in order to
achieve the kind of layout you desire.  Additionally, the arrangement is
dynamically adjusted to accommodate incremental changes to the
configuration, once it is packed.

Note that widgets do not appear until they have had their geometry
specified with a geometry manager.  It’s a common early mistake to leave
out the geometry specification, and then be surprised when the widget is
created but nothing appears.  A widget will appear only after it has
had, for example, the packer’s ‘pack()’ method applied to it.

The pack() method can be called with keyword-option/value pairs that
control where the widget is to appear within its container, and how it
is to behave when the main application window is resized.  Here are some
examples:

     fred.pack()                     # defaults to side = "top"
     fred.pack(side="left")
     fred.pack(expand=1)


File: python.info,  Node: Packer Options,  Next: Coupling Widget Variables,  Prev: The Packer,  Up: Handy Reference

5.25.1.13 Packer Options
........................

For more extensive information on the packer and the options that it can
take, see the man pages and page 183 of John Ousterhout’s book.

anchor

     Anchor type.  Denotes where the packer is to place each content in
     its parcel.

expand

     Boolean, ‘0’ or ‘1’.

fill

     Legal values: ‘'x'’, ‘'y'’, ‘'both'’, ‘'none'’.

ipadx and ipady

     A distance - designating internal padding on each side of the
     content.

padx and pady

     A distance - designating external padding on each side of the
     content.

side

     Legal values are: ‘'left'’, ‘'right'’, ‘'top'’, ‘'bottom'’.


File: python.info,  Node: Coupling Widget Variables,  Next: The Window Manager,  Prev: Packer Options,  Up: Handy Reference

5.25.1.14 Coupling Widget Variables
...................................

The current-value setting of some widgets (like text entry widgets) can
be connected directly to application variables by using special options.
These options are ‘variable’, ‘textvariable’, ‘onvalue’, ‘offvalue’, and
‘value’.  This connection works both ways: if the variable changes for
any reason, the widget it’s connected to will be updated to reflect the
new value.

Unfortunately, in the current implementation of *note tkinter: f6. it is
not possible to hand over an arbitrary Python variable to a widget
through a ‘variable’ or ‘textvariable’ option.  The only kinds of
variables for which this works are variables that are subclassed from a
class called Variable, defined in *note tkinter: f6.

There are many useful subclasses of Variable already defined:
‘StringVar’, ‘IntVar’, ‘DoubleVar’, and ‘BooleanVar’.  To read the
current value of such a variable, call the ‘get()’ method on it, and to
change its value you call the ‘set()’ method.  If you follow this
protocol, the widget will always track the value of the variable, with
no further intervention on your part.

For example:

     import tkinter as tk

     class App(tk.Frame):
         def __init__(self, master):
             super().__init__(master)
             self.pack()

             self.entrythingy = tk.Entry()
             self.entrythingy.pack()

             # Create the application variable.
             self.contents = tk.StringVar()
             # Set it to some value.
             self.contents.set("this is a variable")
             # Tell the entry widget to watch this variable.
             self.entrythingy["textvariable"] = self.contents

             # Define a callback for when the user hits return.
             # It prints the current value of the variable.
             self.entrythingy.bind('<Key-Return>',
                                  self.print_contents)

         def print_contents(self, event):
             print("Hi. The current entry content is:",
                   self.contents.get())

     root = tk.Tk()
     myapp = App(root)
     myapp.mainloop()


File: python.info,  Node: The Window Manager,  Next: Tk Option Data Types,  Prev: Coupling Widget Variables,  Up: Handy Reference

5.25.1.15 The Window Manager
............................

In Tk, there is a utility command, ‘wm’, for interacting with the window
manager.  Options to the ‘wm’ command allow you to control things like
titles, placement, icon bitmaps, and the like.  In *note tkinter: f6,
these commands have been implemented as methods on the ‘Wm’ class.
Toplevel widgets are subclassed from the ‘Wm’ class, and so can call the
‘Wm’ methods directly.

To get at the toplevel window that contains a given widget, you can
often just refer to the widget’s ‘master’.  Of course if the widget has
been packed inside of a frame, the ‘master’ won’t represent a toplevel
window.  To get at the toplevel window that contains an arbitrary
widget, you can call the ‘_root()’ method.  This method begins with an
underscore to denote the fact that this function is part of the
implementation, and not an interface to Tk functionality.

Here are some examples of typical usage:

     import tkinter as tk

     class App(tk.Frame):
         def __init__(self, master=None):
             super().__init__(master)
             self.pack()

     # create the application
     myapp = App()

     #
     # here are method calls to the window manager class
     #
     myapp.master.title("My Do-Nothing Application")
     myapp.master.maxsize(1000, 400)

     # start the program
     myapp.mainloop()


File: python.info,  Node: Tk Option Data Types,  Next: Bindings and Events,  Prev: The Window Manager,  Up: Handy Reference

5.25.1.16 Tk Option Data Types
..............................

anchor

     Legal values are points of the compass: ‘"n"’, ‘"ne"’, ‘"e"’,
     ‘"se"’, ‘"s"’, ‘"sw"’, ‘"w"’, ‘"nw"’, and also ‘"center"’.

bitmap

     There are eight built-in, named bitmaps: ‘'error'’, ‘'gray25'’,
     ‘'gray50'’, ‘'hourglass'’, ‘'info'’, ‘'questhead'’, ‘'question'’,
     ‘'warning'’.  To specify an X bitmap filename, give the full path
     to the file, preceded with an ‘@’, as in
     ‘"@/usr/contrib/bitmap/gumby.bit"’.

boolean

     You can pass integers 0 or 1 or the strings ‘"yes"’ or ‘"no"’.

callback

     This is any Python function that takes no arguments.  For example:

          def print_it():
              print("hi there")
          fred["command"] = print_it

color

     Colors can be given as the names of X colors in the rgb.txt file,
     or as strings representing RGB values in 4 bit: ‘"#RGB"’, 8 bit:
     ‘"#RRGGBB"’, 12 bit: ‘"#RRRGGGBBB"’, or 16 bit: ‘"#RRRRGGGGBBBB"’
     ranges, where R,G,B here represent any legal hex digit.  See page
     160 of Ousterhout’s book for details.

cursor

     The standard X cursor names from ‘cursorfont.h’ can be used,
     without the ‘XC_’ prefix.  For example to get a hand cursor
     (‘XC_hand2’), use the string ‘"hand2"’.  You can also specify a
     bitmap and mask file of your own.  See page 179 of Ousterhout’s
     book.

distance

     Screen distances can be specified in either pixels or absolute
     distances.  Pixels are given as numbers and absolute distances as
     strings, with the trailing character denoting units: ‘c’ for
     centimetres, ‘i’ for inches, ‘m’ for millimetres, ‘p’ for printer’s
     points.  For example, 3.5 inches is expressed as ‘"3.5i"’.

font

     Tk uses a list font name format, such as ‘{courier 10 bold}’.  Font
     sizes with positive numbers are measured in points; sizes with
     negative numbers are measured in pixels.

geometry

     This is a string of the form ‘widthxheight’, where width and height
     are measured in pixels for most widgets (in characters for widgets
     displaying text).  For example: ‘fred["geometry"] = "200x100"’.

justify

     Legal values are the strings: ‘"left"’, ‘"center"’, and ‘"right"’.

region

     This is a string with four space-delimited elements, each of which
     is a legal distance (see above).  For example: ‘"2 3 4 5"’ and ‘"3i
     2i 4.5i 2i"’ and ‘"3c 2c 4c 10.43c"’ are all legal regions.

relief

     Determines what the border style of a widget will be.  Legal values
     are: ‘"raised"’, ‘"sunken"’, ‘"flat"’, ‘"groove"’, and ‘"ridge"’.

scrollcommand

     This is almost always the ‘set()’ method of some scrollbar widget,
     but can be any widget method that takes a single argument.

wrap

     Must be one of: ‘"none"’, ‘"char"’, or ‘"word"’.


File: python.info,  Node: Bindings and Events,  Next: The index Parameter,  Prev: Tk Option Data Types,  Up: Handy Reference

5.25.1.17 Bindings and Events
.............................

The bind method from the widget command allows you to watch for certain
events and to have a callback function trigger when that event type
occurs.  The form of the bind method is:

     def bind(self, sequence, func, add=''):

where:

sequence

     is a string that denotes the target kind of event.  (See the
     ‘bind(3tk)(1)’ man page, and page 201 of John Ousterhout’s book,
     ‘Tcl and the Tk Toolkit (2nd edition)’, for details).

func

     is a Python function, taking one argument, to be invoked when the
     event occurs.  An Event instance will be passed as the argument.
     (Functions deployed this way are commonly known as 'callbacks'.)

add

     is optional, either ‘''’ or ‘'+'’.  Passing an empty string denotes
     that this binding is to replace any other bindings that this event
     is associated with.  Passing a ‘'+'’ means that this function is to
     be added to the list of functions bound to this event type.

For example:

     def turn_red(self, event):
         event.widget["activeforeground"] = "red"

     self.button.bind("<Enter>", self.turn_red)

Notice how the widget field of the event is being accessed in the
‘turn_red()’ callback.  This field contains the widget that caught the X
event.  The following table lists the other event fields you can access,
and how they are denoted in Tk, which can be useful when referring to
the Tk man pages.

Tk       Tkinter Event Field       Tk       Tkinter Event Field
                                            
----------------------------------------------------------------------
                                            
%f       focus                     %A       char
                                            
                                            
%h       height                    %E       send_event
                                            
                                            
%k       keycode                   %K       keysym
                                            
                                            
%s       state                     %N       keysym_num
                                            
                                            
%t       time                      %T       type
                                            
                                            
%w       width                     %W       widget
                                            
                                            
%x       x                         %X       x_root
                                            
                                            
%y       y                         %Y       y_root
                                            

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/bind(3tk)


File: python.info,  Node: The index Parameter,  Next: Images,  Prev: Bindings and Events,  Up: Handy Reference

5.25.1.18 The index Parameter
.............................

A number of widgets require «index» parameters to be passed.  These are
used to point at a specific place in a Text widget, or to particular
characters in an Entry widget, or to particular menu items in a Menu
widget.

Entry widget indexes (index, view index, etc.)

     Entry widgets have options that refer to character positions in the
     text being displayed.  You can use these *note tkinter: f6.
     functions to access these special points in text widgets:

Text widget indexes

     The index notation for Text widgets is very rich and is best
     described in the Tk man pages.

Menu indexes (menu.invoke(), menu.entryconfig(), etc.)

     Some options and methods for menus manipulate specific menu
     entries.  Anytime a menu index is needed for an option or a
     parameter, you may pass in:

        * an integer which refers to the numeric position of the entry
          in the widget, counted from the top, starting with 0;

        * the string ‘"active"’, which refers to the menu position that
          is currently under the cursor;

        * the string ‘"last"’ which refers to the last menu item;

        * An integer preceded by ‘@’, as in ‘@6’, where the integer is
          interpreted as a y pixel coordinate in the menu’s coordinate
          system;

        * the string ‘"none"’, which indicates no menu entry at all,
          most often used with menu.activate() to deactivate all
          entries, and finally,

        * a text string that is pattern matched against the label of the
          menu entry, as scanned from the top of the menu to the bottom.
          Note that this index type is considered after all the others,
          which means that matches for menu items labelled ‘last’,
          ‘active’, or ‘none’ may be interpreted as the above literals,
          instead.


File: python.info,  Node: Images,  Prev: The index Parameter,  Up: Handy Reference

5.25.1.19 Images
................

Images of different formats can be created through the corresponding
subclass of ‘tkinter.Image’:

   * ‘BitmapImage’ for images in XBM format.

   * ‘PhotoImage’ for images in PGM, PPM, GIF and PNG formats.  The
     latter is supported starting with Tk 8.6.

Either type of image is created through either the ‘file’ or the ‘data’
option (other options are available as well).

Cambiato nella versione 3.13: Added the ‘PhotoImage’ method
‘copy_replace()’ to copy a region from one image to other image,
possibly with pixel zooming and/or subsampling.  Add 'from_coords'
parameter to ‘PhotoImage’ methods ‘copy()’, ‘zoom()’ and ‘subsample()’.
Add 'zoom' and 'subsample' parameters to ‘PhotoImage’ method ‘copy()’.

The image object can then be used wherever an ‘image’ option is
supported by some widget (e.g.  labels, buttons, menus).  In these
cases, Tk will not keep a reference to the image.  When the last Python
reference to the image object is deleted, the image data is deleted as
well, and Tk will display an empty box wherever the image was used.

Vedi anche
..........

The Pillow(1) package adds support for formats such as BMP, JPEG, TIFF,
and WebP, among others.

   ---------- Footnotes ----------

   (1) https://python-pillow.org/


File: python.info,  Node: File Handlers,  Prev: Handy Reference,  Up: tkinter — Python interface to Tcl/Tk

5.25.1.20 File Handlers
.......................

Tk allows you to register and unregister a callback function which will
be called from the Tk mainloop when I/O is possible on a file
descriptor.  Only one handler may be registered per file descriptor.
Example code:

     import tkinter
     widget = tkinter.Tk()
     mask = tkinter.READABLE | tkinter.WRITABLE
     widget.tk.createfilehandler(file, mask, callback)
     ...
     widget.tk.deletefilehandler(file)

This feature is not available on Windows.

Since you don’t know how many bytes are available for reading, you may
not want to use the *note BufferedIOBase: 8a4. or *note TextIOBase: 8a5.
*note read(): 1530. or *note readline(): 1531. methods, since these will
insist on reading a predefined number of bytes.  For sockets, the *note
recv(): fa6. or *note recvfrom(): fa7. methods will work fine; for other
files, use raw reads or ‘os.read(file.fileno(), maxbytecount)’.

 -- Metodo: Widget.tk.createfilehandler (file, mask, func)

     Registers the file handler callback function 'func'.  The 'file'
     argument may either be an object with a *note fileno(): 1795.
     method (such as a file or socket object), or an integer file
     descriptor.  The 'mask' argument is an ORed combination of any of
     the three constants below.  The callback is called as follows:

          callback(file, mask)

 -- Metodo: Widget.tk.deletefilehandler (file)

     Unregisters a file handler.

 -- Dati: _tkinter.READABLE
 -- Dati: _tkinter.WRITABLE
 -- Dati: _tkinter.EXCEPTION

     Constants used in the 'mask' arguments.


File: python.info,  Node: tkinter colorchooser — Color choosing dialog,  Next: tkinter font — Tkinter font wrapper,  Prev: tkinter — Python interface to Tcl/Tk,  Up: Graphical user interfaces with Tk

5.25.2 ‘tkinter.colorchooser’ — Color choosing dialog
-----------------------------------------------------

'Source code:' Lib/tkinter/colorchooser.py(1)

__________________________________________________________________

The *note tkinter.colorchooser: f7. module provides the *note Chooser:
42ef. class as an interface to the native color picker dialog.
‘Chooser’ implements a modal color choosing dialog window.  The
‘Chooser’ class inherits from the *note Dialog: 42f0. class.

 -- Classe: tkinter.colorchooser.Chooser (master=None, **options)

 -- Funzione: tkinter.colorchooser.askcolor (color=None, **options)

     Create a color choosing dialog.  A call to this method will show
     the window, wait for the user to make a selection, and return the
     selected color (or ‘None’) to the caller.

Vedi anche
..........

Module *note tkinter.commondialog: f8.

     Tkinter standard dialog module

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/tkinter/colorchooser.py


File: python.info,  Node: tkinter font — Tkinter font wrapper,  Next: Tkinter Dialogs,  Prev: tkinter colorchooser — Color choosing dialog,  Up: Graphical user interfaces with Tk

5.25.3 ‘tkinter.font’ — Tkinter font wrapper
--------------------------------------------

'Source code:' Lib/tkinter/font.py(1)

__________________________________________________________________

The *note tkinter.font: fb. module provides the *note Font: 1cb6. class
for creating and using named fonts.

The different font weights and slants are:

 -- Dati: tkinter.font.NORMAL
 -- Dati: tkinter.font.BOLD
 -- Dati: tkinter.font.ITALIC
 -- Dati: tkinter.font.ROMAN

 -- Classe: tkinter.font.Font (root=None, font=None, name=None,
          exists=False, **options)

     The *note Font: 1cb6. class represents a named font.  'Font'
     instances are given unique names and can be specified by their
     family, size, and style configuration.  Named fonts are Tk’s method
     of creating and identifying fonts as a single object, rather than
     specifying a font by its attributes with each occurrence.

          arguments:

                    'font' - font specifier tuple (family, size, options)
                    'name' - unique font name
                    'exists' - self points to existing named font if true

          additional keyword options (ignored if 'font' is specified):

                    'family' - font family i.e. Courier, Times
                    'size' - font size
                         If 'size' is positive it is interpreted as size in points.
                         If 'size' is a negative number its absolute value is treated
                         as size in pixels.
                    'weight' - font emphasis (NORMAL, BOLD)
                    'slant' - ROMAN, ITALIC
                    'underline' - font underlining (0 - none, 1 - underline)
                    'overstrike' - font strikeout (0 - none, 1 - strikeout)

      -- Metodo: actual (option=None, displayof=None)

          Return the attributes of the font.

      -- Metodo: cget (option)

          Retrieve an attribute of the font.

      -- Metodo: config (**options)

          Modify attributes of the font.

      -- Metodo: copy ()

          Return new instance of the current font.

      -- Metodo: measure (text, displayof=None)

          Return amount of space the text would occupy on the specified
          display when formatted in the current font.  If no display is
          specified then the main application window is assumed.

      -- Metodo: metrics (*options, **kw)

          Return font-specific data.  Options include:

          'ascent' - distance between baseline and highest point that a

               character of the font can occupy

          'descent' - distance between baseline and lowest point that a

               character of the font can occupy

          'linespace' - minimum vertical separation necessary between any two

               characters of the font that ensures no vertical overlap
               between lines.

          'fixed' - 1 if font is fixed-width else 0

 -- Funzione: tkinter.font.families (root=None, displayof=None)

     Return the different font families.

 -- Funzione: tkinter.font.names (root=None)

     Return the names of defined fonts.

 -- Funzione: tkinter.font.nametofont (name, root=None)

     Return a *note Font: 1cb6. representation of a tk named font.

     Cambiato nella versione 3.10: The 'root' parameter was added.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/tkinter/font.py


File: python.info,  Node: Tkinter Dialogs,  Next: tkinter messagebox — Tkinter message prompts,  Prev: tkinter font — Tkinter font wrapper,  Up: Graphical user interfaces with Tk

5.25.4 Tkinter Dialogs
----------------------

* Menu:

* tkinter.simpledialog — Standard Tkinter input dialogs: tkinter simpledialog — Standard Tkinter input dialogs.
* tkinter.filedialog — File selection dialogs: tkinter filedialog — File selection dialogs.
* tkinter.commondialog — Dialog window templates: tkinter commondialog — Dialog window templates.


File: python.info,  Node: tkinter simpledialog — Standard Tkinter input dialogs,  Next: tkinter filedialog — File selection dialogs,  Up: Tkinter Dialogs

5.25.4.1 ‘tkinter.simpledialog’ — Standard Tkinter input dialogs
................................................................

'Source code:' Lib/tkinter/simpledialog.py(1)

__________________________________________________________________

The *note tkinter.simpledialog: fe. module contains convenience classes
and functions for creating simple modal dialogs to get a value from the
user.

 -- Funzione: tkinter.simpledialog.askfloat (title, prompt, **kw)
 -- Funzione: tkinter.simpledialog.askinteger (title, prompt, **kw)
 -- Funzione: tkinter.simpledialog.askstring (title, prompt, **kw)

     The above three functions provide dialogs that prompt the user to
     enter a value of the desired type.

 -- Classe: tkinter.simpledialog.Dialog (parent, title=None)

     The base class for custom dialogs.

      -- Metodo: body (master)

          Override to construct the dialog’s interface and return the
          widget that should have initial focus.

      -- Metodo: buttonbox ()

          Default behaviour adds OK and Cancel buttons.  Override for
          custom button layouts.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/tkinter/simpledialog.py


File: python.info,  Node: tkinter filedialog — File selection dialogs,  Next: tkinter commondialog — Dialog window templates,  Prev: tkinter simpledialog — Standard Tkinter input dialogs,  Up: Tkinter Dialogs

5.25.4.2 ‘tkinter.filedialog’ — File selection dialogs
......................................................

'Source code:' Lib/tkinter/filedialog.py(1)

__________________________________________________________________

The *note tkinter.filedialog: fa. module provides classes and factory
functions for creating file/directory selection windows.

* Menu:

* Native Load/Save Dialogs::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/tkinter/filedialog.py


File: python.info,  Node: Native Load/Save Dialogs,  Up: tkinter filedialog — File selection dialogs

5.25.4.3 Native Load/Save Dialogs
.................................

The following classes and functions provide file dialog windows that
combine a native look-and-feel with configuration options to customize
behaviour.  The following keyword arguments are applicable to the
classes and functions listed below:

          'parent' - the window to place the dialog on top of

          'title' - the title of the window

          'initialdir' - the directory that the dialog starts in

          'initialfile' - the file selected upon opening of the dialog

          'filetypes' - a sequence of (label, pattern) tuples, “*” wildcard is allowed

          'defaultextension' - default extension to append to file (save dialogs)

          'multiple' - when true, selection of multiple items is allowed

'Static factory functions'

The below functions when called create a modal, native look-and-feel
dialog, wait for the user’s selection, then return the selected value(s)
or ‘None’ to the caller.

 -- Funzione: tkinter.filedialog.askopenfile (mode='r', **options)
 -- Funzione: tkinter.filedialog.askopenfiles (mode='r', **options)

     The above two functions create an *note Open: 430e. dialog and
     return the opened file object(s) in read-only mode.

 -- Funzione: tkinter.filedialog.asksaveasfile (mode='w', **options)

     Create a *note SaveAs: 4310. dialog and return a file object opened
     in write-only mode.

 -- Funzione: tkinter.filedialog.askopenfilename (**options)
 -- Funzione: tkinter.filedialog.askopenfilenames (**options)

     The above two functions create an *note Open: 430e. dialog and
     return the selected filename(s) that correspond to existing
     file(s).

 -- Funzione: tkinter.filedialog.asksaveasfilename (**options)

     Create a *note SaveAs: 4310. dialog and return the selected
     filename.

 -- Funzione: tkinter.filedialog.askdirectory (**options)

          Prompt user to select a directory.
          Additional keyword option:
               'mustexist' - determines if selection must be an existing directory.

 -- Classe: tkinter.filedialog.Open (master=None, **options)
 -- Classe: tkinter.filedialog.SaveAs (master=None, **options)

     The above two classes provide native dialog windows for saving and
     loading files.

'Convenience classes'

The below classes are used for creating file/directory windows from
scratch.  These do not emulate the native look-and-feel of the platform.

 -- Classe: tkinter.filedialog.Directory (master=None, **options)

     Create a dialog prompting the user to select a directory.

     Nota: The 'FileDialog' class should be subclassed for custom event
     handling and behaviour.

 -- Classe: tkinter.filedialog.FileDialog (master, title=None)

     Create a basic file selection dialog.

      -- Metodo: cancel_command (event=None)

          Trigger the termination of the dialog window.

      -- Metodo: dirs_double_event (event)

          Event handler for double-click event on directory.

      -- Metodo: dirs_select_event (event)

          Event handler for click event on directory.

      -- Metodo: files_double_event (event)

          Event handler for double-click event on file.

      -- Metodo: files_select_event (event)

          Event handler for single-click event on file.

      -- Metodo: filter_command (event=None)

          Filter the files by directory.

      -- Metodo: get_filter ()

          Retrieve the file filter currently in use.

      -- Metodo: get_selection ()

          Retrieve the currently selected item.

      -- Metodo: go (dir_or_file=os.curdir, pattern='*', default='',
               key=None)

          Render dialog and start event loop.

      -- Metodo: ok_event (event)

          Exit dialog returning current selection.

      -- Metodo: quit (how=None)

          Exit dialog returning filename, if any.

      -- Metodo: set_filter (dir, pat)

          Set the file filter.

      -- Metodo: set_selection (file)

          Update the current file selection to 'file'.

 -- Classe: tkinter.filedialog.LoadFileDialog (master, title=None)

     A subclass of FileDialog that creates a dialog window for selecting
     an existing file.

      -- Metodo: ok_command ()

          Test that a file is provided and that the selection indicates
          an already existing file.

 -- Classe: tkinter.filedialog.SaveFileDialog (master, title=None)

     A subclass of FileDialog that creates a dialog window for selecting
     a destination file.

      -- Metodo: ok_command ()

          Test whether or not the selection points to a valid file that
          is not a directory.  Confirmation is required if an already
          existing file is selected.


File: python.info,  Node: tkinter commondialog — Dialog window templates,  Prev: tkinter filedialog — File selection dialogs,  Up: Tkinter Dialogs

5.25.4.4 ‘tkinter.commondialog’ — Dialog window templates
.........................................................

'Source code:' Lib/tkinter/commondialog.py(1)

__________________________________________________________________

The *note tkinter.commondialog: f8. module provides the *note Dialog:
42f0. class that is the base class for dialogs defined in other
supporting modules.

 -- Classe: tkinter.commondialog.Dialog (master=None, **options)

      -- Metodo: show (**options)

          Render the Dialog window.

Vedi anche
..........

Modules *note tkinter.messagebox: fc, *note Lettura e Scrittura di File:
2050.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/tkinter/commondialog.py


File: python.info,  Node: tkinter messagebox — Tkinter message prompts,  Next: tkinter scrolledtext — Scrolled Text Widget,  Prev: Tkinter Dialogs,  Up: Graphical user interfaces with Tk

5.25.5 ‘tkinter.messagebox’ — Tkinter message prompts
-----------------------------------------------------

'Source code:' Lib/tkinter/messagebox.py(1)

__________________________________________________________________

The *note tkinter.messagebox: fc. module provides a template base class
as well as a variety of convenience methods for commonly used
configurations.  The message boxes are modal and will return a subset of
(‘True’, ‘False’, ‘None’, *note OK: 432d, *note CANCEL: 432e, *note YES:
432f, *note NO: 4330.) based on the user’s selection.  Common message
box styles and layouts include but are not limited to:

[image src="python-figures/tk_msg.png"]


Figure
 -- Classe: tkinter.messagebox.Message (master=None, **options)

     Create a message window with an application-specified message, an
     icon and a set of buttons.  Each of the buttons in the message
     window is identified by a unique symbolic name (see the 'type'
     options).

     The following options are supported:

          'command'

               Specifies the function to invoke when the user closes the
               dialog.  The name of the button clicked by the user to
               close the dialog is passed as argument.  This is only
               available on macOS.

          'default'

               Gives the *note symbolic name: 4332. of the default
               button for this message window (*note OK: 432d, *note
               CANCEL: 432e, and so on).  If this option is not
               specified, the first button in the dialog will be made
               the default.

          'detail'

               Specifies an auxiliary message to the main message given
               by the 'message' option.  The message detail will be
               presented beneath the main message and, where supported
               by the OS, in a less emphasized font than the main
               message.

          'icon'

               Specifies an *note icon: 4333. to display.  If this
               option is not specified, then the *note INFO: 4334. icon
               will be displayed.

          'message'

               Specifies the message to display in this message box.
               The default value is an empty string.

          'parent'

               Makes the specified window the logical parent of the
               message box.  The message box is displayed on top of its
               parent window.

          'title'

               Specifies a string to display as the title of the message
               box.  This option is ignored on macOS, where platform
               guidelines forbid the use of a title on this kind of
               dialog.

          'type'

               Arranges for a *note predefined set of buttons: 4335. to
               be displayed.

      -- Metodo: show (**options)

          Display a message window and wait for the user to select one
          of the buttons.  Then return the symbolic name of the selected
          button.  Keyword arguments can override options specified in
          the constructor.

'Information message box'

 -- Funzione: tkinter.messagebox.showinfo (title=None, message=None,
          **options)

     Creates and displays an information message box with the specified
     title and message.

'Warning message boxes'

 -- Funzione: tkinter.messagebox.showwarning (title=None, message=None,
          **options)

     Creates and displays a warning message box with the specified title
     and message.

 -- Funzione: tkinter.messagebox.showerror (title=None, message=None,
          **options)

     Creates and displays an error message box with the specified title
     and message.

'Question message boxes'

 -- Funzione: tkinter.messagebox.askquestion (title=None, message=None,
          *, type=YESNO, **options)

     Ask a question.  By default shows buttons *note YES: 432f. and
     *note NO: 4330.  Returns the symbolic name of the selected button.

 -- Funzione: tkinter.messagebox.askokcancel (title=None, message=None,
          **options)

     Ask if operation should proceed.  Shows buttons *note OK: 432d. and
     *note CANCEL: 432e.  Returns ‘True’ if the answer is ok and ‘False’
     otherwise.

 -- Funzione: tkinter.messagebox.askretrycancel (title=None,
          message=None, **options)

     Ask if operation should be retried.  Shows buttons *note RETRY:
     433d. and *note CANCEL: 432e.  Return ‘True’ if the answer is yes
     and ‘False’ otherwise.

 -- Funzione: tkinter.messagebox.askyesno (title=None, message=None,
          **options)

     Ask a question.  Shows buttons *note YES: 432f. and *note NO: 4330.
     Returns ‘True’ if the answer is yes and ‘False’ otherwise.

 -- Funzione: tkinter.messagebox.askyesnocancel (title=None,
          message=None, **options)

     Ask a question.  Shows buttons *note YES: 432f, *note NO: 4330. and
     *note CANCEL: 432e.  Return ‘True’ if the answer is yes, ‘None’ if
     cancelled, and ‘False’ otherwise.
Symbolic names of buttons:

 -- Dati: tkinter.messagebox.ABORT = 'abort'

 -- Dati: tkinter.messagebox.RETRY = 'retry'

 -- Dati: tkinter.messagebox.IGNORE = 'ignore'

 -- Dati: tkinter.messagebox.OK = 'ok'

 -- Dati: tkinter.messagebox.CANCEL = 'cancel'

 -- Dati: tkinter.messagebox.YES = 'yes'

 -- Dati: tkinter.messagebox.NO = 'no'
Predefined sets of buttons:

 -- Dati: tkinter.messagebox.ABORTRETRYIGNORE = 'abortretryignore'

     Displays three buttons whose symbolic names are *note ABORT: 4340,
     *note RETRY: 433d. and *note IGNORE: 4341.

 -- Dati: tkinter.messagebox.OK = 'ok'

     Displays one button whose symbolic name is *note OK: 432d.

 -- Dati: tkinter.messagebox.OKCANCEL = 'okcancel'

     Displays two buttons whose symbolic names are *note OK: 432d. and
     *note CANCEL: 432e.

 -- Dati: tkinter.messagebox.RETRYCANCEL = 'retrycancel'

     Displays two buttons whose symbolic names are *note RETRY: 433d.
     and *note CANCEL: 432e.

 -- Dati: tkinter.messagebox.YESNO = 'yesno'

     Displays two buttons whose symbolic names are *note YES: 432f. and
     *note NO: 4330.

 -- Dati: tkinter.messagebox.YESNOCANCEL = 'yesnocancel'

     Displays three buttons whose symbolic names are *note YES: 432f,
     *note NO: 4330. and *note CANCEL: 432e.
Icon images:

 -- Dati: tkinter.messagebox.ERROR = 'error'

 -- Dati: tkinter.messagebox.INFO = 'info'

 -- Dati: tkinter.messagebox.QUESTION = 'question'

 -- Dati: tkinter.messagebox.WARNING = 'warning'

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/tkinter/messagebox.py


File: python.info,  Node: tkinter scrolledtext — Scrolled Text Widget,  Next: tkinter dnd — Drag and drop support,  Prev: tkinter messagebox — Tkinter message prompts,  Up: Graphical user interfaces with Tk

5.25.6 ‘tkinter.scrolledtext’ — Scrolled Text Widget
----------------------------------------------------

'Source code:' Lib/tkinter/scrolledtext.py(1)

__________________________________________________________________

The *note tkinter.scrolledtext: fd. module provides a class of the same
name which implements a basic text widget which has a vertical scroll
bar configured to do the «right thing.» Using the *note ScrolledText:
434d. class is a lot easier than setting up a text widget and scroll bar
directly.

The text widget and scrollbar are packed together in a ‘Frame’, and the
methods of the ‘Grid’ and ‘Pack’ geometry managers are acquired from the
‘Frame’ object.  This allows the *note ScrolledText: 434d. widget to be
used directly to achieve most normal geometry management behavior.

Should more specific control be necessary, the following attributes are
available:

 -- Classe: tkinter.scrolledtext.ScrolledText (master=None, **kw)

      -- Attributo: frame

          The frame which surrounds the text and scroll bar widgets.

      -- Attributo: vbar

          The scroll bar widget.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/tkinter/scrolledtext.py


File: python.info,  Node: tkinter dnd — Drag and drop support,  Next: tkinter ttk — Tk themed widgets,  Prev: tkinter scrolledtext — Scrolled Text Widget,  Up: Graphical user interfaces with Tk

5.25.7 ‘tkinter.dnd’ — Drag and drop support
--------------------------------------------

'Source code:' Lib/tkinter/dnd.py(1)

__________________________________________________________________

     Nota: This is experimental and due to be deprecated when it is
     replaced with the Tk DND.

The *note tkinter.dnd: f9. module provides drag-and-drop support for
objects within a single application, within the same window or between
windows.  To enable an object to be dragged, you must create an event
binding for it that starts the drag-and-drop process.  Typically, you
bind a ButtonPress event to a callback function that you write (see
*note Bindings and Events: 42e1.).  The function should call *note
dnd_start(): 4353, where “source” is the object to be dragged, and
“event” is the event that invoked the call (the argument to your
callback function).

Selection of a target object occurs as follows:

  1. Top-down search of area under mouse for target widget

        * Target widget should have a callable 'dnd_accept' attribute

        * If 'dnd_accept' is not present or returns ‘None’, search moves
          to parent widget

        * If no target widget is found, then the target object is ‘None’

  2. Call to '<old_target>.dnd_leave(source, event)'

  3. Call to '<new_target>.dnd_enter(source, event)'

  4. Call to '<target>.dnd_commit(source, event)' to notify of drop

  5. Call to '<source>.dnd_end(target, event)' to signal end of
     drag-and-drop

 -- Classe: tkinter.dnd.DndHandler (source, event)

     The 'DndHandler' class handles drag-and-drop events tracking Motion
     and ButtonRelease events on the root of the event widget.

      -- Metodo: cancel (event=None)

          Cancel the drag-and-drop process.

      -- Metodo: finish (event, commit=0)

          Execute end of drag-and-drop functions.

      -- Metodo: on_motion (event)

          Inspect area below mouse for target objects while drag is
          performed.

      -- Metodo: on_release (event)

          Signal end of drag when the release pattern is triggered.

 -- Funzione: tkinter.dnd.dnd_start (source, event)

     Factory function for drag-and-drop process.

Vedi anche
..........

*note Bindings and Events: 42e1.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/tkinter/dnd.py


File: python.info,  Node: tkinter ttk — Tk themed widgets,  Next: IDLE — Python editor and shell<2>,  Prev: tkinter dnd — Drag and drop support,  Up: Graphical user interfaces with Tk

5.25.8 ‘tkinter.ttk’ — Tk themed widgets
----------------------------------------

'Source code:' Lib/tkinter/ttk.py(1)

__________________________________________________________________

The *note tkinter.ttk: ff. module provides access to the Tk themed
widget set, introduced in Tk 8.5.  It provides additional benefits
including anti-aliased font rendering under X11 and window transparency
(requiring a composition window manager on X11).

The basic idea for *note tkinter.ttk: ff. is to separate, to the extent
possible, the code implementing a widget’s behavior from the code
implementing its appearance.

Vedi anche
..........

Tk Widget Styling Support(2)

     A document introducing theming support for Tk

* Menu:

* Using Ttk::
* Ttk Widgets::
* Widget::
* Combobox::
* Spinbox::
* Notebook::
* Progressbar::
* Separator::
* Sizegrip::
* Treeview::
* Ttk Styling::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/tkinter/ttk.py

   (2) https://core.tcl.tk/tips/doc/trunk/tip/48.md


File: python.info,  Node: Using Ttk,  Next: Ttk Widgets,  Up: tkinter ttk — Tk themed widgets

5.25.8.1 Using Ttk
..................

To start using Ttk, import its module:

     from tkinter import ttk

To override the basic Tk widgets, the import should follow the Tk
import:

     from tkinter import *
     from tkinter.ttk import *

That code causes several *note tkinter.ttk: ff. widgets (‘Button’,
‘Checkbutton’, ‘Entry’, ‘Frame’, ‘Label’, ‘LabelFrame’, ‘Menubutton’,
‘PanedWindow’, ‘Radiobutton’, ‘Scale’ and ‘Scrollbar’) to automatically
replace the Tk widgets.

This has the direct benefit of using the new widgets which gives a
better look and feel across platforms; however, the replacement widgets
are not completely compatible.  The main difference is that widget
options such as «fg», «bg» and others related to widget styling are no
longer present in Ttk widgets.  Instead, use the ‘ttk.Style’ class for
improved styling effects.

Vedi anche
..........

Converting existing applications to use Tile widgets(1)

     A monograph (using Tcl terminology) about differences typically
     encountered when moving applications to use the new widgets.

   ---------- Footnotes ----------

   (1) https://tktable.sourceforge.net/tile/doc/converting.txt


File: python.info,  Node: Ttk Widgets,  Next: Widget,  Prev: Using Ttk,  Up: tkinter ttk — Tk themed widgets

5.25.8.2 Ttk Widgets
....................

Ttk comes with 18 widgets, twelve of which already existed in tkinter:
‘Button’, ‘Checkbutton’, ‘Entry’, ‘Frame’, ‘Label’, ‘LabelFrame’,
‘Menubutton’, ‘PanedWindow’, ‘Radiobutton’, ‘Scale’, ‘Scrollbar’, and
*note Spinbox: d8f.  The other six are new: *note Combobox: 435e, *note
Notebook: 435f, *note Progressbar: 4360, ‘Separator’, ‘Sizegrip’ and
*note Treeview: c89.  And all them are subclasses of *note Widget: 4361.

Using the Ttk widgets gives the application an improved look and feel.
As discussed above, there are differences in how the styling is coded.

Tk code:

     l1 = tkinter.Label(text="Test", fg="black", bg="white")
     l2 = tkinter.Label(text="Test", fg="black", bg="white")

Ttk code:

     style = ttk.Style()
     style.configure("BW.TLabel", foreground="black", background="white")

     l1 = ttk.Label(text="Test", style="BW.TLabel")
     l2 = ttk.Label(text="Test", style="BW.TLabel")

For more information about *note TtkStyling: 4362, see the *note Style:
560. class documentation.


File: python.info,  Node: Widget,  Next: Combobox,  Prev: Ttk Widgets,  Up: tkinter ttk — Tk themed widgets

5.25.8.3 Widget
...............

‘ttk.Widget’ defines standard options and methods supported by Tk themed
widgets and is not supposed to be directly instantiated.

* Menu:

* Standard Options::
* Scrollable Widget Options::
* Label Options::
* Compatibility Options::
* Widget States::
* ttk.Widget: ttk Widget.


File: python.info,  Node: Standard Options,  Next: Scrollable Widget Options,  Up: Widget

5.25.8.4 Standard Options
.........................

All the ‘ttk’ Widgets accept the following options:

Option          Description
                
-----------------------------------------------------------------------------------
                
class           Specifies the window class.  The class is used when querying the
                option database for the window’s other options, to determine the
                default bindtags for the window, and to select the widget’s
                default layout and style.  This option is read-only, and may
                only be specified when the window is created.
                
                
cursor          Specifies the mouse cursor to be used for the widget.  If set to
                the empty string (the default), the cursor is inherited for the
                parent widget.
                
                
takefocus       Determines whether the window accepts the focus during keyboard
                traversal.  0, 1 or an empty string is returned.  If 0 is
                returned, it means that the window should be skipped entirely
                during keyboard traversal.  If 1, it means that the window
                should receive the input focus as long as it is viewable.  And
                an empty string means that the traversal scripts make the
                decision about whether or not to focus on the window.
                
                
style           May be used to specify a custom widget style.
                


File: python.info,  Node: Scrollable Widget Options,  Next: Label Options,  Prev: Standard Options,  Up: Widget

5.25.8.5 Scrollable Widget Options
..................................

The following options are supported by widgets that are controlled by a
scrollbar.

Option               Description
                     
-----------------------------------------------------------------------------------
                     
xscrollcommand       Used to communicate with horizontal scrollbars.
                     
                     When the view in the widget’s window change, the widget
                     will generate a Tcl command based on the scrollcommand.
                     
                     Usually this option consists of the method
                     ‘Scrollbar.set()’ of some scrollbar.  This will cause the
                     scrollbar to be updated whenever the view in the window
                     changes.
                     
                     
yscrollcommand       Used to communicate with vertical scrollbars.  For some
                     more information, see above.
                     


File: python.info,  Node: Label Options,  Next: Compatibility Options,  Prev: Scrollable Widget Options,  Up: Widget

5.25.8.6 Label Options
......................

The following options are supported by labels, buttons and other
button-like widgets.

Option             Description
                   
-----------------------------------------------------------------------------------
                   
text               Specifies a text string to be displayed inside the widget.
                   
                   
textvariable       Specifies a name whose value will be used in place of the
                   text option resource.
                   
                   
underline          If set, specifies the index (0-based) of a character to
                   underline in the text string.  The underline character is
                   used for mnemonic activation.
                   
                   
image              Specifies an image to display.  This is a list of 1 or more
                   elements.  The first element is the default image name.  The
                   rest of the list if a sequence of statespec/value pairs as
                   defined by *note Style.map(): 1cce, specifying different
                   images to use when the widget is in a particular state or a
                   combination of states.  All images in the list should have
                   the same size.
                   
                   
compound           Specifies how to display the image relative to the text, in
                   the case both text and images options are present.  Valid
                   values are:
                   
                      * text: display text only
                   
                      * image: display image only
                   
                      * top, bottom, left, right: display image above, below,
                        left of, or right of the text, respectively.
                   
                      * none: the default.  display the image if present,
                        otherwise the text.
                   
                   
width              If greater than zero, specifies how much space, in character
                   widths, to allocate for the text label, if less than zero,
                   specifies a minimum width.  If zero or unspecified, the
                   natural width of the text label is used.
                   


File: python.info,  Node: Compatibility Options,  Next: Widget States,  Prev: Label Options,  Up: Widget

5.25.8.7 Compatibility Options
..............................

Option       Description
             
----------------------------------------------------------------------------------
             
state        May be set to «normal» or «disabled» to control the «disabled»
             state bit.  This is a write-only option: setting it changes the
             widget state, but the *note Widget.state(): 4368. method does not
             affect this option.
             


File: python.info,  Node: Widget States,  Next: ttk Widget,  Prev: Compatibility Options,  Up: Widget

5.25.8.8 Widget States
......................

The widget state is a bitmap of independent state flags.

Flag             Description
                 
-----------------------------------------------------------------------------------
                 
active           The mouse cursor is over the widget and pressing a mouse button
                 will cause some action to occur
                 
                 
disabled         Widget is disabled under program control
                 
                 
focus            Widget has keyboard focus
                 
                 
pressed          Widget is being pressed
                 
                 
selected         «On», «true», or «current» for things like Checkbuttons and
                 radiobuttons
                 
                 
background       Windows and Mac have a notion of an «active» or foreground
                 window.  The 'background' state is set for widgets in a
                 background window, and cleared for those in the foreground
                 window
                 
                 
readonly         Widget should not allow user modification
                 
                 
alternate        A widget-specific alternate display format
                 
                 
invalid          The widget’s value is invalid
                 

A state specification is a sequence of state names, optionally prefixed
with an exclamation point indicating that the bit is off.


File: python.info,  Node: ttk Widget,  Prev: Widget States,  Up: Widget

5.25.8.9 ttk.Widget
...................

Besides the methods described below, the ‘ttk.Widget’ supports the
methods ‘tkinter.Widget.cget()’ and ‘tkinter.Widget.configure()’.

 -- Classe: tkinter.ttk.Widget

      -- Metodo: identify (x, y)

          Returns the name of the element at position 'x' 'y', or the
          empty string if the point does not lie within any element.

          'x' and 'y' are pixel coordinates relative to the widget.

      -- Metodo: instate (statespec, callback=None, *args, **kw)

          Test the widget’s state.  If a callback is not specified,
          returns ‘True’ if the widget state matches 'statespec' and
          ‘False’ otherwise.  If callback is specified then it is called
          with args if widget state matches 'statespec'.

      -- Metodo: state (statespec=None)

          Modify or inquire widget state.  If 'statespec' is specified,
          sets the widget state according to it and return a new
          'statespec' indicating which flags were changed.  If
          'statespec' is not specified, returns the currently enabled
          state flags.

     'statespec' will usually be a list or a tuple.


File: python.info,  Node: Combobox,  Next: Spinbox,  Prev: Widget,  Up: tkinter ttk — Tk themed widgets

5.25.8.10 Combobox
..................

The ‘ttk.Combobox’ widget combines a text field with a pop-down list of
values.  This widget is a subclass of ‘Entry’.

Besides the methods inherited from *note Widget: 4361.: ‘Widget.cget()’,
‘Widget.configure()’, *note Widget.identify(): 436b, *note
Widget.instate(): 436c. and *note Widget.state(): 4368, and the
following inherited from ‘Entry’: ‘Entry.bbox()’, ‘Entry.delete()’,
‘Entry.icursor()’, ‘Entry.index()’, ‘Entry.insert()’,
‘Entry.selection()’, ‘Entry.xview()’, it has some other methods,
described at ‘ttk.Combobox’.

* Menu:

* Options::
* Virtual events::
* ttk.Combobox: ttk Combobox.


File: python.info,  Node: Options,  Next: Virtual events,  Up: Combobox

5.25.8.11 Options
.................

This widget accepts the following specific options:

Option                Description
                      
-----------------------------------------------------------------------------------
                      
exportselection       Boolean value.  If set, the widget selection is linked to
                      the Window Manager selection (which can be returned by
                      invoking Misc.selection_get, for example).
                      
                      
justify               Specifies how the text is aligned within the widget.  One
                      of «left», «center», or «right».
                      
                      
height                Specifies the height of the pop-down listbox, in rows.
                      
                      
postcommand           A script (possibly registered with Misc.register) that is
                      called immediately before displaying the values.  It may
                      specify which values to display.
                      
                      
state                 One of «normal», «readonly», or «disabled».  In the
                      «readonly» state, the value may not be edited directly,
                      and the user can only selection of the values from the
                      dropdown list.  In the «normal» state, the text field is
                      directly editable.  In the «disabled» state, no
                      interaction is possible.
                      
                      
textvariable          Specifies a name whose value is linked to the widget
                      value.  Whenever the value associated with that name
                      changes, the widget value is updated, and vice versa.  See
                      ‘tkinter.StringVar’.
                      
                      
values                Specifies the list of values to display in the drop-down
                      listbox.
                      
                      
width                 Specifies an integer value indicating the desired width of
                      the entry window, in average-size characters of the
                      widget’s font.
                      


File: python.info,  Node: Virtual events,  Next: ttk Combobox,  Prev: Options,  Up: Combobox

5.25.8.12 Virtual events
........................

The combobox widgets generates a '<<ComboboxSelected>>' virtual event
when the user selects an element from the list of values.


File: python.info,  Node: ttk Combobox,  Prev: Virtual events,  Up: Combobox

5.25.8.13 ttk.Combobox
......................

 -- Classe: tkinter.ttk.Combobox

      -- Metodo: current (newindex=None)

          If 'newindex' is specified, sets the combobox value to the
          element position 'newindex'.  Otherwise, returns the index of
          the current value or -1 if the current value is not in the
          values list.

      -- Metodo: get ()

          Returns the current value of the combobox.

      -- Metodo: set (value)

          Sets the value of the combobox to 'value'.


File: python.info,  Node: Spinbox,  Next: Notebook,  Prev: Combobox,  Up: tkinter ttk — Tk themed widgets

5.25.8.14 Spinbox
.................

The ‘ttk.Spinbox’ widget is a ‘ttk.Entry’ enhanced with increment and
decrement arrows.  It can be used for numbers or lists of string values.
This widget is a subclass of ‘Entry’.

Besides the methods inherited from *note Widget: 4361.: ‘Widget.cget()’,
‘Widget.configure()’, *note Widget.identify(): 436b, *note
Widget.instate(): 436c. and *note Widget.state(): 4368, and the
following inherited from ‘Entry’: ‘Entry.bbox()’, ‘Entry.delete()’,
‘Entry.icursor()’, ‘Entry.index()’, ‘Entry.insert()’, ‘Entry.xview()’,
it has some other methods, described at ‘ttk.Spinbox’.

* Menu:

* Options: Options<2>.
* Virtual events: Virtual events<2>.
* ttk.Spinbox: ttk Spinbox.


File: python.info,  Node: Options<2>,  Next: Virtual events<2>,  Up: Spinbox

5.25.8.15 Options
.................

This widget accepts the following specific options:

Option                     Description
                           
--------------------------------------------------------------------------------------
                           
from                       Float value.  If set, this is the minimum value to which
                           the decrement button will decrement.  Must be spelled as
                           ‘from_’ when used as an argument, since ‘from’ is a
                           Python keyword.
                           
                           
to                         Float value.  If set, this is the maximum value to which
                           the increment button will increment.
                           
                           
increment                  Float value.  Specifies the amount which the
                           increment/decrement buttons change the value.  Defaults
                           to 1.0.
                           
                           
values                     Sequence of string or float values.  If specified, the
                           increment/decrement buttons will cycle through the items
                           in this sequence rather than incrementing or
                           decrementing numbers.
                           
                           
wrap                       Boolean value.  If ‘True’, increment and decrement
                           buttons will cycle from the ‘to’ value to the ‘from’
                           value or the ‘from’ value to the ‘to’ value,
                           respectively.
                           
                           
format                     String value.  This specifies the format of numbers set
                           by the increment/decrement buttons.  It must be in the
                           form «%W.Pf», where W is the padded width of the value,
                           P is the precision, and “%” and “f” are literal.
                           
                           
command                    Python callable.  Will be called with no arguments
                           whenever either of the increment or decrement buttons
                           are pressed.
                           


File: python.info,  Node: Virtual events<2>,  Next: ttk Spinbox,  Prev: Options<2>,  Up: Spinbox

5.25.8.16 Virtual events
........................

The spinbox widget generates an '<<Increment>>' virtual event when the
user presses <Up>, and a '<<Decrement>>' virtual event when the user
presses <Down>.


File: python.info,  Node: ttk Spinbox,  Prev: Virtual events<2>,  Up: Spinbox

5.25.8.17 ttk.Spinbox
.....................

 -- Classe: tkinter.ttk.Spinbox

      -- Metodo: get ()

          Returns the current value of the spinbox.

      -- Metodo: set (value)

          Sets the value of the spinbox to 'value'.


File: python.info,  Node: Notebook,  Next: Progressbar,  Prev: Spinbox,  Up: tkinter ttk — Tk themed widgets

5.25.8.18 Notebook
..................

Ttk Notebook widget manages a collection of windows and displays a
single one at a time.  Each child window is associated with a tab, which
the user may select to change the currently displayed window.

* Menu:

* Options: Options<3>.
* Tab Options::
* Tab Identifiers::
* Virtual Events::
* ttk.Notebook: ttk Notebook.


File: python.info,  Node: Options<3>,  Next: Tab Options,  Up: Notebook

5.25.8.19 Options
.................

This widget accepts the following specific options:

Option        Description
              
-----------------------------------------------------------------------------------
              
height        If present and greater than zero, specifies the desired height of
              the pane area (not including internal padding or tabs).
              Otherwise, the maximum height of all panes is used.
              
              
padding       Specifies the amount of extra space to add around the outside of
              the notebook.  The padding is a list up to four length
              specifications left top right bottom.  If fewer than four elements
              are specified, bottom defaults to top, right defaults to left, and
              top defaults to left.
              
              
width         If present and greater than zero, specified the desired width of
              the pane area (not including internal padding).  Otherwise, the
              maximum width of all panes is used.
              


File: python.info,  Node: Tab Options,  Next: Tab Identifiers,  Prev: Options<3>,  Up: Notebook

5.25.8.20 Tab Options
.....................

There are also specific options for tabs:

Option          Description
                
-----------------------------------------------------------------------------------
                
state           Either «normal», «disabled» or «hidden».  If «disabled», then
                the tab is not selectable.  If «hidden», then the tab is not
                shown.
                
                
sticky          Specifies how the child window is positioned within the pane
                area.  Value is a string containing zero or more of the
                characters «n», «s», «e» or «w».  Each letter refers to a side
                (north, south, east or west) that the child window will stick
                to, as per the ‘grid()’ geometry manager.
                
                
padding         Specifies the amount of extra space to add between the notebook
                and this pane.  Syntax is the same as for the option padding
                used by this widget.
                
                
text            Specifies a text to be displayed in the tab.
                
                
image           Specifies an image to display in the tab.  See the option image
                described in *note Widget: 4361.
                
                
compound        Specifies how to display the image relative to the text, in the
                case both options text and image are present.  See
                *note Label Options: 4366. for legal values.
                
                
underline       Specifies the index (0-based) of a character to underline in the
                text string.  The underlined character is used for mnemonic
                activation if *note Notebook.enable_traversal(): 437d. is
                called.
                


File: python.info,  Node: Tab Identifiers,  Next: Virtual Events,  Prev: Tab Options,  Up: Notebook

5.25.8.21 Tab Identifiers
.........................

The tab_id present in several methods of ‘ttk.Notebook’ may take any of
the following forms:

   * An integer between zero and the number of tabs

   * The name of a child window

   * A positional specification of the form «@x,y», which identifies the
     tab

   * The literal string «current», which identifies the currently
     selected tab

   * The literal string «end», which returns the number of tabs (only
     valid for *note Notebook.index(): 437f.)


File: python.info,  Node: Virtual Events,  Next: ttk Notebook,  Prev: Tab Identifiers,  Up: Notebook

5.25.8.22 Virtual Events
........................

This widget generates a '<<NotebookTabChanged>>' virtual event after a
new tab is selected.


File: python.info,  Node: ttk Notebook,  Prev: Virtual Events,  Up: Notebook

5.25.8.23 ttk.Notebook
......................

 -- Classe: tkinter.ttk.Notebook

      -- Metodo: add (child, **kw)

          Adds a new tab to the notebook.

          If window is currently managed by the notebook but hidden, it
          is restored to its previous position.

          See *note Tab Options: 437c. for the list of available
          options.

      -- Metodo: forget (tab_id)

          Removes the tab specified by 'tab_id', unmaps and unmanages
          the associated window.

      -- Metodo: hide (tab_id)

          Hides the tab specified by 'tab_id'.

          The tab will not be displayed, but the associated window
          remains managed by the notebook and its configuration
          remembered.  Hidden tabs may be restored with the *note add():
          4382. command.

      -- Metodo: identify (x, y)

          Returns the name of the tab element at position 'x', 'y', or
          the empty string if none.

      -- Metodo: index (tab_id)

          Returns the numeric index of the tab specified by 'tab_id', or
          the total number of tabs if 'tab_id' is the string «end».

      -- Metodo: insert (pos, child, **kw)

          Inserts a pane at the specified position.

          'pos' is either the string «end», an integer index, or the
          name of a managed child.  If 'child' is already managed by the
          notebook, moves it to the specified position.

          See *note Tab Options: 437c. for the list of available
          options.

      -- Metodo: select (tab_id=None)

          Selects the specified 'tab_id'.

          The associated child window will be displayed, and the
          previously selected window (if different) is unmapped.  If
          'tab_id' is omitted, returns the widget name of the currently
          selected pane.

      -- Metodo: tab (tab_id, option=None, **kw)

          Query or modify the options of the specific 'tab_id'.

          If 'kw' is not given, returns a dictionary of the tab option
          values.  If 'option' is specified, returns the value of that
          'option'.  Otherwise, sets the options to the corresponding
          values.

      -- Metodo: tabs ()

          Returns a list of windows managed by the notebook.

      -- Metodo: enable_traversal ()

          Enable keyboard traversal for a toplevel window containing
          this notebook.

          This will extend the bindings for the toplevel window
          containing the notebook as follows:

             * ‘Control’-‘Tab’: selects the tab following the currently
               selected one.

             * ‘Shift’-‘Control’-‘Tab’: selects the tab preceding the
               currently selected one.

             * ‘Alt’-‘K’: where 'K' is the mnemonic (underlined)
               character of any tab, will select that tab.

          Multiple notebooks in a single toplevel may be enabled for
          traversal, including nested notebooks.  However, notebook
          traversal only works properly if all panes have the notebook
          they are in as master.


File: python.info,  Node: Progressbar,  Next: Separator,  Prev: Notebook,  Up: tkinter ttk — Tk themed widgets

5.25.8.24 Progressbar
.....................

The ‘ttk.Progressbar’ widget shows the status of a long-running
operation.  It can operate in two modes: 1) the determinate mode which
shows the amount completed relative to the total amount of work to be
done and 2) the indeterminate mode which provides an animated display to
let the user know that work is progressing.

* Menu:

* Options: Options<4>.
* ttk.Progressbar: ttk Progressbar.


File: python.info,  Node: Options<4>,  Next: ttk Progressbar,  Up: Progressbar

5.25.8.25 Options
.................

This widget accepts the following specific options:

Option         Description
               
-----------------------------------------------------------------------------------
               
orient         One of «horizontal» or «vertical».  Specifies the orientation of
               the progress bar.
               
               
length         Specifies the length of the long axis of the progress bar (width
               if horizontal, height if vertical).
               
               
mode           One of «determinate» or «indeterminate».
               
               
maximum        A number specifying the maximum value.  Defaults to 100.
               
               
value          The current value of the progress bar.  In «determinate» mode,
               this represents the amount of work completed.  In «indeterminate»
               mode, it is interpreted as modulo 'maximum'; that is, the
               progress bar completes one «cycle» when its value increases by
               'maximum'.
               
               
variable       A name which is linked to the option value.  If specified, the
               value of the progress bar is automatically set to the value of
               this name whenever the latter is modified.
               
               
phase          Read-only option.  The widget periodically increments the value
               of this option whenever its value is greater than 0 and, in
               determinate mode, less than maximum.  This option may be used by
               the current theme to provide additional animation effects.
               


File: python.info,  Node: ttk Progressbar,  Prev: Options<4>,  Up: Progressbar

5.25.8.26 ttk.Progressbar
.........................

 -- Classe: tkinter.ttk.Progressbar

      -- Metodo: start (interval=None)

          Begin autoincrement mode: schedules a recurring timer event
          that calls *note Progressbar.step(): 438e. every 'interval'
          milliseconds.  If omitted, 'interval' defaults to 50
          milliseconds.

      -- Metodo: step (amount=None)

          Increments the progress bar’s value by 'amount'.

          'amount' defaults to 1.0 if omitted.

      -- Metodo: stop ()

          Stop autoincrement mode: cancels any recurring timer event
          initiated by *note Progressbar.start(): 438d. for this
          progress bar.


File: python.info,  Node: Separator,  Next: Sizegrip,  Prev: Progressbar,  Up: tkinter ttk — Tk themed widgets

5.25.8.27 Separator
...................

The ‘ttk.Separator’ widget displays a horizontal or vertical separator
bar.

It has no other methods besides the ones inherited from ‘ttk.Widget’.

* Menu:

* Options: Options<5>.


File: python.info,  Node: Options<5>,  Up: Separator

5.25.8.28 Options
.................

This widget accepts the following specific option:

Option       Description
             
----------------------------------------------------------------------------------
             
orient       One of «horizontal» or «vertical».  Specifies the orientation of
             the separator.
             


File: python.info,  Node: Sizegrip,  Next: Treeview,  Prev: Separator,  Up: tkinter ttk — Tk themed widgets

5.25.8.29 Sizegrip
..................

The ‘ttk.Sizegrip’ widget (also known as a grow box) allows the user to
resize the containing toplevel window by pressing and dragging the grip.

This widget has neither specific options nor specific methods, besides
the ones inherited from ‘ttk.Widget’.

* Menu:

* Platform-specific notes::
* Bugs::


File: python.info,  Node: Platform-specific notes,  Next: Bugs,  Up: Sizegrip

5.25.8.30 Platform-specific notes
.................................

   * On macOS, toplevel windows automatically include a built-in size
     grip by default.  Adding a ‘Sizegrip’ is harmless, since the
     built-in grip will just mask the widget.


File: python.info,  Node: Bugs,  Prev: Platform-specific notes,  Up: Sizegrip

5.25.8.31 Bugs
..............

   * If the containing toplevel’s position was specified relative to the
     right or bottom of the screen (e.g.  ….), the ‘Sizegrip’ widget
     will not resize the window.

   * This widget supports only «southeast» resizing.


File: python.info,  Node: Treeview,  Next: Ttk Styling,  Prev: Sizegrip,  Up: tkinter ttk — Tk themed widgets

5.25.8.32 Treeview
..................

The ‘ttk.Treeview’ widget displays a hierarchical collection of items.
Each item has a textual label, an optional image, and an optional list
of data values.  The data values are displayed in successive columns
after the tree label.

The order in which data values are displayed may be controlled by
setting the widget option ‘displaycolumns’.  The tree widget can also
display column headings.  Columns may be accessed by number or symbolic
names listed in the widget option columns.  See *note Column
Identifiers: 4396.

Each item is identified by a unique name.  The widget will generate item
IDs if they are not supplied by the caller.  There is a distinguished
root item, named ‘{}’.  The root item itself is not displayed; its
children appear at the top level of the hierarchy.

Each item also has a list of tags, which can be used to associate event
bindings with individual items and control the appearance of the item.

The Treeview widget supports horizontal and vertical scrolling,
according to the options described in *note Scrollable Widget Options:
4365. and the methods *note Treeview.xview(): 4397. and *note
Treeview.yview(): 4398.

* Menu:

* Options: Options<6>.
* Item Options::
* Tag Options::
* Column Identifiers::
* Virtual Events: Virtual Events<2>.
* ttk.Treeview: ttk Treeview.


File: python.info,  Node: Options<6>,  Next: Item Options,  Up: Treeview

5.25.8.33 Options
.................

This widget accepts the following specific options:

Option               Description
                     
----------------------------------------------------------------------------------
                     
columns              A list of column identifiers, specifying the number of
                     columns and their names.
                     
                     
displaycolumns       A list of column identifiers (either symbolic or integer
                     indices) specifying which data columns are displayed and
                     the order in which they appear, or the string «#all».
                     
                     
height               Specifies the number of rows which should be visible.
                     Note: the requested width is determined from the sum of
                     the column widths.
                     
                     
padding              Specifies the internal padding for the widget.  The
                     padding is a list of up to four length specifications.
                     
                     
selectmode           Controls how the built-in class bindings manage the
                     selection.  One of «extended», «browse» or «none».  If set
                     to «extended» (the default), multiple items may be
                     selected.  If «browse», only a single item will be
                     selected at a time.  If «none», the selection will not be
                     changed.
                     
                     Note that the application code and tag bindings can set
                     the selection however they wish, regardless of the value
                     of this option.
                     
                     
show                 A list containing zero or more of the following values,
                     specifying which elements of the tree to display.
                     
                        * tree: display tree labels in column #0.
                     
                        * headings: display the heading row.
                     
                     The default is «tree headings», i.e., show all elements.
                     
                     'Note': Column #0 always refers to the tree column, even
                     if show=»tree» is not specified.
                     


File: python.info,  Node: Item Options,  Next: Tag Options,  Prev: Options<6>,  Up: Treeview

5.25.8.34 Item Options
......................

The following item options may be specified for items in the insert and
item widget commands.

Option       Description
             
---------------------------------------------------------------------------------
             
text         The textual label to display for the item.
             
             
image        A Tk Image, displayed to the left of the label.
             
             
values       The list of values associated with the item.
             
             Each item should have the same number of values as the widget
             option columns.  If there are fewer values than columns, the
             remaining values are assumed empty.  If there are more values
             than columns, the extra values are ignored.
             
             
open         ‘True’/‘False’ value indicating whether the item’s children
             should be displayed or hidden.
             
             
tags         A list of tags associated with this item.
             


File: python.info,  Node: Tag Options,  Next: Column Identifiers,  Prev: Item Options,  Up: Treeview

5.25.8.35 Tag Options
.....................

The following options may be specified on tags:

Option           Description
                 
---------------------------------------------------------------------------------
                 
foreground       Specifies the text foreground color.
                 
                 
background       Specifies the cell or item background color.
                 
                 
font             Specifies the font to use when drawing text.
                 
                 
image            Specifies the item image, in case the item’s image option is
                 empty.
                 


File: python.info,  Node: Column Identifiers,  Next: Virtual Events<2>,  Prev: Tag Options,  Up: Treeview

5.25.8.36 Column Identifiers
............................

Column identifiers take any of the following forms:

   * A symbolic name from the list of columns option.

   * An integer n, specifying the nth data column.

   * A string of the form #n, where n is an integer, specifying the nth
     display column.

Notes:

   * Item’s option values may be displayed in a different order than the
     order in which they are stored.

   * Column #0 always refers to the tree column, even if show=»tree» is
     not specified.

A data column number is an index into an item’s option values list; a
display column number is the column number in the tree where the values
are displayed.  Tree labels are displayed in column #0.  If option
displaycolumns is not set, then data column n is displayed in column
#n+1.  Again, 'column #0 always refers to the tree column'.


File: python.info,  Node: Virtual Events<2>,  Next: ttk Treeview,  Prev: Column Identifiers,  Up: Treeview

5.25.8.37 Virtual Events
........................

The Treeview widget generates the following virtual events.

Event                    Description
                         
--------------------------------------------------------------------------------
                         
<<TreeviewSelect>>       Generated whenever the selection changes.
                         
                         
<<TreeviewOpen>>         Generated just before settings the focus item to
                         open=True.
                         
                         
<<TreeviewClose>>        Generated just after setting the focus item to
                         open=False.
                         

The *note Treeview.focus(): 439d. and *note Treeview.selection(): c88.
methods can be used to determine the affected item or items.


File: python.info,  Node: ttk Treeview,  Prev: Virtual Events<2>,  Up: Treeview

5.25.8.38 ttk.Treeview
......................

 -- Classe: tkinter.ttk.Treeview

      -- Metodo: bbox (item, column=None)

          Returns the bounding box (relative to the treeview widget’s
          window) of the specified 'item' in the form (x, y, width,
          height).

          If 'column' is specified, returns the bounding box of that
          cell.  If the 'item' is not visible (i.e., if it is a
          descendant of a closed item or is scrolled offscreen), returns
          an empty string.

      -- Metodo: get_children (item=None)

          Returns the list of children belonging to 'item'.

          If 'item' is not specified, returns root children.

      -- Metodo: set_children (item, *newchildren)

          Replaces 'item'’s child with 'newchildren'.

          Children present in 'item' that are not present in
          'newchildren' are detached from the tree.  No items in
          'newchildren' may be an ancestor of 'item'.  Note that not
          specifying 'newchildren' results in detaching 'item'’s
          children.

      -- Metodo: column (column, option=None, **kw)

          Query or modify the options for the specified 'column'.

          If 'kw' is not given, returns a dict of the column option
          values.  If 'option' is specified then the value for that
          'option' is returned.  Otherwise, sets the options to the
          corresponding values.

          The valid options/values are:

          'id'

               Returns the column name.  This is a read-only option.

          'anchor': One of the standard Tk anchor values.

               Specifies how the text in this column should be aligned
               with respect to the cell.

          'minwidth': width

               The minimum width of the column in pixels.  The treeview
               widget will not make the column any smaller than
               specified by this option when the widget is resized or
               the user drags a column.

          'stretch': ‘True’/‘False’

               Specifies whether the column’s width should be adjusted
               when the widget is resized.

          'width': width

               The width of the column in pixels.

          To configure the tree column, call this with column = «#0»

      -- Metodo: delete (*items)

          Delete all specified 'items' and all their descendants.

          The root item may not be deleted.

      -- Metodo: detach (*items)

          Unlinks all of the specified 'items' from the tree.

          The items and all of their descendants are still present, and
          may be reinserted at another point in the tree, but will not
          be displayed.

          The root item may not be detached.

      -- Metodo: exists (item)

          Returns ‘True’ if the specified 'item' is present in the tree.

      -- Metodo: focus (item=None)

          If 'item' is specified, sets the focus item to 'item'.
          Otherwise, returns the current focus item, or “” if there is
          none.

      -- Metodo: heading (column, option=None, **kw)

          Query or modify the heading options for the specified
          'column'.

          If 'kw' is not given, returns a dict of the heading option
          values.  If 'option' is specified then the value for that
          'option' is returned.  Otherwise, sets the options to the
          corresponding values.

          The valid options/values are:

          'text': text

               The text to display in the column heading.

          'image': imageName

               Specifies an image to display to the right of the column
               heading.

          'anchor': anchor

               Specifies how the heading text should be aligned.  One of
               the standard Tk anchor values.

          'command': callback

               A callback to be invoked when the heading label is
               pressed.

          To configure the tree column heading, call this with column =
          «#0».

      -- Metodo: identify (component, x, y)

          Returns a description of the specified 'component' under the
          point given by 'x' and 'y', or the empty string if no such
          'component' is present at that position.

      -- Metodo: identify_row (y)

          Returns the item ID of the item at position 'y'.

      -- Metodo: identify_column (x)

          Returns the data column identifier of the cell at position
          'x'.

          The tree column has ID #0.

      -- Metodo: identify_region (x, y)

          Returns one of:

          region          meaning
                          
          -----------------------------------------------------------
                          
          heading         Tree heading area.
                          
                          
          separator       Space between two columns headings.
                          
                          
          tree            The tree area.
                          
                          
          cell            A data cell.
                          

          Availability: Tk 8.6.

      -- Metodo: identify_element (x, y)

          Returns the element at position 'x', 'y'.

          Availability: Tk 8.6.

      -- Metodo: index (item)

          Returns the integer index of 'item' within its parent’s list
          of children.

      -- Metodo: insert (parent, index, iid=None, **kw)

          Creates a new item and returns the item identifier of the
          newly created item.

          'parent' is the item ID of the parent item, or the empty
          string to create a new top-level item.  'index' is an integer,
          or the value «end», specifying where in the list of parent’s
          children to insert the new item.  If 'index' is less than or
          equal to zero, the new node is inserted at the beginning; if
          'index' is greater than or equal to the current number of
          children, it is inserted at the end.  If 'iid' is specified,
          it is used as the item identifier; 'iid' must not already
          exist in the tree.  Otherwise, a new unique identifier is
          generated.

          See *note Item Options: 439a. for the list of available
          options.

      -- Metodo: item (item, option=None, **kw)

          Query or modify the options for the specified 'item'.

          If no options are given, a dict with options/values for the
          item is returned.  If 'option' is specified then the value for
          that option is returned.  Otherwise, sets the options to the
          corresponding values as given by 'kw'.

      -- Metodo: move (item, parent, index)

          Moves 'item' to position 'index' in 'parent'’s list of
          children.

          It is illegal to move an item under one of its descendants.
          If 'index' is less than or equal to zero, 'item' is moved to
          the beginning; if greater than or equal to the number of
          children, it is moved to the end.  If 'item' was detached it
          is reattached.

      -- Metodo: next (item)

          Returns the identifier of 'item'’s next sibling, or “” if
          'item' is the last child of its parent.

      -- Metodo: parent (item)

          Returns the ID of the parent of 'item', or “” if 'item' is at
          the top level of the hierarchy.

      -- Metodo: prev (item)

          Returns the identifier of 'item'’s previous sibling, or “” if
          'item' is the first child of its parent.

      -- Metodo: reattach (item, parent, index)

          An alias for *note Treeview.move(): 43af.

      -- Metodo: see (item)

          Ensure that 'item' is visible.

          Sets all of 'item'’s ancestors open option to ‘True’, and
          scrolls the widget if necessary so that 'item' is within the
          visible portion of the tree.

      -- Metodo: selection ()

          Returns a tuple of selected items.

          Cambiato nella versione 3.8: ‘selection()’ no longer takes
          arguments.  For changing the selection state use the following
          selection methods.

      -- Metodo: selection_set (*items)

          'items' becomes the new selection.

          Cambiato nella versione 3.6: 'items' can be passed as separate
          arguments, not just as a single tuple.

      -- Metodo: selection_add (*items)

          Add 'items' to the selection.

          Cambiato nella versione 3.6: 'items' can be passed as separate
          arguments, not just as a single tuple.

      -- Metodo: selection_remove (*items)

          Remove 'items' from the selection.

          Cambiato nella versione 3.6: 'items' can be passed as separate
          arguments, not just as a single tuple.

      -- Metodo: selection_toggle (*items)

          Toggle the selection state of each item in 'items'.

          Cambiato nella versione 3.6: 'items' can be passed as separate
          arguments, not just as a single tuple.

      -- Metodo: set (item, column=None, value=None)

          With one argument, returns a dictionary of column/value pairs
          for the specified 'item'.  With two arguments, returns the
          current value of the specified 'column'.  With three
          arguments, sets the value of given 'column' in given 'item' to
          the specified 'value'.

      -- Metodo: tag_bind (tagname, sequence=None, callback=None)

          Bind a callback for the given event 'sequence' to the tag
          'tagname'.  When an event is delivered to an item, the
          callbacks for each of the item’s tags option are called.

      -- Metodo: tag_configure (tagname, option=None, **kw)

          Query or modify the options for the specified 'tagname'.

          If 'kw' is not given, returns a dict of the option settings
          for 'tagname'.  If 'option' is specified, returns the value
          for that 'option' for the specified 'tagname'.  Otherwise,
          sets the options to the corresponding values for the given
          'tagname'.

      -- Metodo: tag_has (tagname, item=None)

          If 'item' is specified, returns 1 or 0 depending on whether
          the specified 'item' has the given 'tagname'.  Otherwise,
          returns a list of all items that have the specified tag.

          Availability: Tk 8.6

      -- Metodo: xview (*args)

          Query or modify horizontal position of the treeview.

      -- Metodo: yview (*args)

          Query or modify vertical position of the treeview.


File: python.info,  Node: Ttk Styling,  Prev: Treeview,  Up: tkinter ttk — Tk themed widgets

5.25.8.39 Ttk Styling
.....................

Each widget in ‘ttk’ is assigned a style, which specifies the set of
elements making up the widget and how they are arranged, along with
dynamic and default settings for element options.  By default the style
name is the same as the widget’s class name, but it may be overridden by
the widget’s style option.  If you don’t know the class name of a
widget, use the method ‘Misc.winfo_class()’ (somewidget.winfo_class()).

Vedi anche
..........

Tcl'2004 conference presentation(1)

     This document explains how the theme engine works

 -- Classe: tkinter.ttk.Style

     This class is used to manipulate the style database.

      -- Metodo: configure (style, query_opt=None, **kw)

          Query or set the default value of the specified option(s) in
          'style'.

          Each key in 'kw' is an option and each value is a string
          identifying the value for that option.

          For example, to change every default button to be a flat
          button with some padding and a different background color:

               from tkinter import ttk
               import tkinter

               root = tkinter.Tk()

               ttk.Style().configure("TButton", padding=6, relief="flat",
                  background="#ccc")

               btn = ttk.Button(text="Sample")
               btn.pack()

               root.mainloop()

      -- Metodo: map (style, query_opt=None, **kw)

          Query or sets dynamic values of the specified option(s) in
          'style'.

          Each key in 'kw' is an option and each value should be a list
          or a tuple (usually) containing statespecs grouped in tuples,
          lists, or some other preference.  A statespec is a compound of
          one or more states and then a value.

          An example may make it more understandable:

               import tkinter
               from tkinter import ttk

               root = tkinter.Tk()

               style = ttk.Style()
               style.map("C.TButton",
                   foreground=[('pressed', 'red'), ('active', 'blue')],
                   background=[('pressed', '!disabled', 'black'), ('active', 'white')]
                   )

               colored_btn = ttk.Button(text="Test", style="C.TButton").pack()

               root.mainloop()

          Note that the order of the (states, value) sequences for an
          option does matter, if the order is changed to ‘[('active',
          'blue'), ('pressed', 'red')]’ in the foreground option, for
          example, the result would be a blue foreground when the widget
          were in active or pressed states.

      -- Metodo: lookup (style, option, state=None, default=None)

          Returns the value specified for 'option' in 'style'.

          If 'state' is specified, it is expected to be a sequence of
          one or more states.  If the 'default' argument is set, it is
          used as a fallback value in case no specification for option
          is found.

          To check what font a Button uses by default:

               from tkinter import ttk

               print(ttk.Style().lookup("TButton", "font"))

      -- Metodo: layout (style, layoutspec=None)

          Define the widget layout for given 'style'.  If 'layoutspec'
          is omitted, return the layout specification for given style.

          'layoutspec', if specified, is expected to be a list or some
          other sequence type (excluding strings), where each item
          should be a tuple and the first item is the layout name and
          the second item should have the format described in *note
          Layouts: 43c0.

          To understand the format, see the following example (it is not
          intended to do anything useful):

               from tkinter import ttk
               import tkinter

               root = tkinter.Tk()

               style = ttk.Style()
               style.layout("TMenubutton", [
                  ("Menubutton.background", None),
                  ("Menubutton.button", {"children":
                      [("Menubutton.focus", {"children":
                          [("Menubutton.padding", {"children":
                              [("Menubutton.label", {"side": "left", "expand": 1})]
                          })]
                      })]
                  }),
               ])

               mbtn = ttk.Menubutton(text='Text')
               mbtn.pack()
               root.mainloop()

      -- Metodo: element_create (elementname, etype, *args, **kw)

          Create a new element in the current theme, of the given
          'etype' which is expected to be either «image», «from» or
          «vsapi».  The latter is only available in Tk 8.6 on Windows.

          If «image» is used, 'args' should contain the default image
          name followed by statespec/value pairs (this is the
          imagespec), and 'kw' may have the following options:

          border=padding

               padding is a list of up to four integers, specifying the
               left, top, right, and bottom borders, respectively.

          height=height

               Specifies a minimum height for the element.  If less than
               zero, the base image’s height is used as a default.

          padding=padding

               Specifies the element’s interior padding.  Defaults to
               border’s value if not specified.

          sticky=spec

               Specifies how the image is placed within the final
               parcel.  spec contains zero or more characters «n», «s»,
               «w», or «e».

          width=width

               Specifies a minimum width for the element.  If less than
               zero, the base image’s width is used as a default.

          Example:

               img1 = tkinter.PhotoImage(master=root, file='button.png')
               img1 = tkinter.PhotoImage(master=root, file='button-pressed.png')
               img1 = tkinter.PhotoImage(master=root, file='button-active.png')
               style = ttk.Style(root)
               style.element_create('Button.button', 'image',
                                    img1, ('pressed', img2), ('active', img3),
                                    border=(2, 4), sticky='we')

          If «from» is used as the value of 'etype', *note
          element_create(): 55f. will clone an existing element.  'args'
          is expected to contain a themename, from which the element
          will be cloned, and optionally an element to clone from.  If
          this element to clone from is not specified, an empty element
          will be used.  'kw' is discarded.

          Example:

               style = ttk.Style(root)
               style.element_create('plain.background', 'from', 'default')

          If «vsapi» is used as the value of 'etype', *note
          element_create(): 55f. will create a new element in the
          current theme whose visual appearance is drawn using the
          Microsoft Visual Styles API which is responsible for the
          themed styles on Windows XP and Vista.  'args' is expected to
          contain the Visual Styles class and part as given in the
          Microsoft documentation followed by an optional sequence of
          tuples of ttk states and the corresponding Visual Styles API
          state value.  'kw' may have the following options:

          padding=padding

               Specify the element’s interior padding.  'padding' is a
               list of up to four integers specifying the left, top,
               right and bottom padding quantities respectively.  If
               fewer than four elements are specified, bottom defaults
               to top, right defaults to left, and top defaults to left.
               In other words, a list of three numbers specify the left,
               vertical, and right padding; a list of two numbers
               specify the horizontal and the vertical padding; a single
               number specifies the same padding all the way around the
               widget.  This option may not be mixed with any other
               options.

          margins=padding

               Specifies the elements exterior padding.  'padding' is a
               list of up to four integers specifying the left, top,
               right and bottom padding quantities respectively.  This
               option may not be mixed with any other options.

          width=width

               Specifies the width for the element.  If this option is
               set then the Visual Styles API will not be queried for
               the recommended size or the part.  If this option is set
               then 'height' should also be set.  The 'width' and
               'height' options cannot be mixed with the 'padding' or
               'margins' options.

          height=height

               Specifies the height of the element.  See the comments
               for 'width'.

          Example:

               style = ttk.Style(root)
               style.element_create('pin', 'vsapi', 'EXPLORERBAR', 3, [
                                    ('pressed', '!selected', 3),
                                    ('active', '!selected', 2),
                                    ('pressed', 'selected', 6),
                                    ('active', 'selected', 5),
                                    ('selected', 4),
                                    ('', 1)])
               style.layout('Explorer.Pin',
                            [('Explorer.Pin.pin', {'sticky': 'news'})])
               pin = ttk.Checkbutton(style='Explorer.Pin')
               pin.pack(expand=True, fill='both')

          Cambiato nella versione 3.13: Added support of the «vsapi»
          element factory.

      -- Metodo: element_names ()

          Returns the list of elements defined in the current theme.

      -- Metodo: element_options (elementname)

          Returns the list of 'elementname'’s options.

      -- Metodo: theme_create (themename, parent=None, settings=None)

          Create a new theme.

          It is an error if 'themename' already exists.  If 'parent' is
          specified, the new theme will inherit styles, elements and
          layouts from the parent theme.  If 'settings' are present they
          are expected to have the same syntax used for *note
          theme_settings(): 43c4.

      -- Metodo: theme_settings (themename, settings)

          Temporarily sets the current theme to 'themename', apply
          specified 'settings' and then restore the previous theme.

          Each key in 'settings' is a style and each value may contain
          the keys “configure”, “map”, “layout” and “element create” and
          they are expected to have the same format as specified by the
          methods *note Style.configure(): 43bd, *note Style.map():
          1cce, *note Style.layout(): 43bf. and *note
          Style.element_create(): 55f. respectively.

          As an example, let’s change the Combobox for the default theme
          a bit:

               from tkinter import ttk
               import tkinter

               root = tkinter.Tk()

               style = ttk.Style()
               style.theme_settings("default", {
                  "TCombobox": {
                      "configure": {"padding": 5},
                      "map": {
                          "background": [("active", "green2"),
                                         ("!disabled", "green4")],
                          "fieldbackground": [("!disabled", "green3")],
                          "foreground": [("focus", "OliveDrab1"),
                                         ("!disabled", "OliveDrab2")]
                      }
                  }
               })

               combo = ttk.Combobox().pack()

               root.mainloop()

      -- Metodo: theme_names ()

          Returns a list of all known themes.

      -- Metodo: theme_use (themename=None)

          If 'themename' is not given, returns the theme in use.
          Otherwise, sets the current theme to 'themename', refreshes
          all widgets and emits a <<ThemeChanged>> event.

* Menu:

* Layouts::

   ---------- Footnotes ----------

   (1) https://tktable.sourceforge.net/tile/tile-tcl2004.pdf


File: python.info,  Node: Layouts,  Up: Ttk Styling

5.25.8.40 Layouts
.................

A layout can be just ‘None’, if it takes no options, or a dict of
options specifying how to arrange the element.  The layout mechanism
uses a simplified version of the pack geometry manager: given an initial
cavity, each element is allocated a parcel.

The valid options/values are:

'side': whichside

     Specifies which side of the cavity to place the element; one of
     top, right, bottom or left.  If omitted, the element occupies the
     entire cavity.

'sticky': nswe

     Specifies where the element is placed inside its allocated parcel.

'unit': 0 or 1

     If set to 1, causes the element and all of its descendants to be
     treated as a single element for the purposes of *note
     Widget.identify(): 436b. et al.  It’s used for things like
     scrollbar thumbs with grips.

'children': [sublayout… ]

     Specifies a list of elements to place inside the element.  Each
     element is a tuple (or other sequence type) where the first item is
     the layout name, and the other is a *note Layout: 43c0.


File: python.info,  Node: IDLE — Python editor and shell<2>,  Next: turtle — Turtle graphics,  Prev: tkinter ttk — Tk themed widgets,  Up: Graphical user interfaces with Tk

5.25.9 IDLE — Python editor and shell
-------------------------------------

'Source code:' Lib/idlelib/(1)

__________________________________________________________________

IDLE is Python’s Integrated Development and Learning Environment.

IDLE has the following features:

   * cross-platform: works mostly the same on Windows, Unix, and macOS

   * Python shell window (interactive interpreter) with colorizing of
     code input, output, and error messages

   * multi-window text editor with multiple undo, Python colorizing,
     smart indent, call tips, auto completion, and other features

   * search within any window, replace within editor windows, and search
     through multiple files (grep)

   * debugger with persistent breakpoints, stepping, and viewing of
     global and local namespaces

   * configuration, browsers, and other dialogs

The IDLE application is implemented in the *note idlelib: 77. package.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

* Menu:

* Menus::
* Editing and Navigation::
* Startup and Code Execution::
* Help and Preferences::
* idlelib — implementation of IDLE application::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/idlelib/


File: python.info,  Node: Menus,  Next: Editing and Navigation,  Up: IDLE — Python editor and shell<2>

5.25.9.1 Menus
..............

IDLE has two main window types, the Shell window and the Editor window.
It is possible to have multiple editor windows simultaneously.  On
Windows and Linux, each has its own top menu.  Each menu documented
below indicates which window type it is associated with.

Output windows, such as used for Edit => Find in Files, are a subtype of
editor window.  They currently have the same top menu but a different
default title and context menu.

On macOS, there is one application menu.  It dynamically changes
according to the window currently selected.  It has an IDLE menu, and
some entries described below are moved around to conform to Apple
guidelines.

* Menu:

* File menu (Shell and Editor): File menu Shell and Editor.
* Edit menu (Shell and Editor): Edit menu Shell and Editor.
* Format menu (Editor window only): Format menu Editor window only.
* Run menu (Editor window only): Run menu Editor window only.
* Shell menu (Shell window only): Shell menu Shell window only.
* Debug menu (Shell window only): Debug menu Shell window only.
* Options menu (Shell and Editor): Options menu Shell and Editor.
* Window menu (Shell and Editor): Window menu Shell and Editor.
* Help menu (Shell and Editor): Help menu Shell and Editor.
* Context menus::


File: python.info,  Node: File menu Shell and Editor,  Next: Edit menu Shell and Editor,  Up: Menus

5.25.9.2 File menu (Shell and Editor)
.....................................

New File

     Create a new file editing window.

Open…

     Open an existing file with an Open dialog.

Open Module…

     Open an existing module (searches sys.path).

Recent Files

     Open a list of recent files.  Click one to open it.

Module Browser

     Show functions, classes, and methods in the current Editor file in
     a tree structure.  In the shell, open a module first.

Path Browser

     Show sys.path directories, modules, functions, classes and methods
     in a tree structure.

Save

     Save the current window to the associated file, if there is one.
     Windows that have been changed since being opened or last saved
     have a * before and after the window title.  If there is no
     associated file, do Save As instead.

Save As…

     Save the current window with a Save As dialog.  The file saved
     becomes the new associated file for the window.  (If your file
     manager is set to hide extensions, the current extension will be
     omitted in the file name box.  If the new filename has no “.”,
     “.py” and “.txt” will be added for Python and text files, except
     that on macOS Aqua,”.py” is added for all files.)

Save Copy As…

     Save the current window to different file without changing the
     associated file.  (See Save As note above about filename
     extensions.)

Print Window

     Print the current window to the default printer.

Close Window

     Close the current window (if an unsaved editor, ask to save; if an
     unsaved Shell, ask to quit execution).  Calling ‘exit()’ or
     ‘close()’ in the Shell window also closes Shell.  If this is the
     only window, also exit IDLE.

Exit IDLE

     Close all windows and quit IDLE (ask to save unsaved edit windows).


File: python.info,  Node: Edit menu Shell and Editor,  Next: Format menu Editor window only,  Prev: File menu Shell and Editor,  Up: Menus

5.25.9.3 Edit menu (Shell and Editor)
.....................................

Undo

     Undo the last change to the current window.  A maximum of 1000
     changes may be undone.

Redo

     Redo the last undone change to the current window.

Select All

     Select the entire contents of the current window.

Cut

     Copy selection into the system-wide clipboard; then delete the
     selection.

Copy

     Copy selection into the system-wide clipboard.

Paste

     Insert contents of the system-wide clipboard into the current
     window.

The clipboard functions are also available in context menus.

Find…

     Open a search dialog with many options

Find Again

     Repeat the last search, if there is one.

Find Selection

     Search for the currently selected string, if there is one.

Find in Files…

     Open a file search dialog.  Put results in a new output window.

Replace…

     Open a search-and-replace dialog.

Go to Line

     Move the cursor to the beginning of the line requested and make
     that line visible.  A request past the end of the file goes to the
     end.  Clear any selection and update the line and column status.

Show Completions

     Open a scrollable list allowing selection of existing names.  See
     *note Completions: 43ce. in the Editing and Navigation section
     below.

Expand Word

     Expand a prefix you have typed to match a full word in the same
     window; repeat to get a different expansion.

Show Call Tip

     After an unclosed parenthesis for a function, open a small window
     with function parameter hints.  See *note Calltips: 43cf. in the
     Editing and Navigation section below.

Show Surrounding Parens

     Highlight the surrounding parenthesis.


File: python.info,  Node: Format menu Editor window only,  Next: Run menu Editor window only,  Prev: Edit menu Shell and Editor,  Up: Menus

5.25.9.4 Format menu (Editor window only)
.........................................

Format Paragraph

     Rewrap the text block containing the text insert cursor.  Avoid
     code lines.  See *note Format block: 43d2. in the Editing and
     Navigation section below.

Indent Region

     Shift selected lines right by the indent width (default 4 spaces).

Dedent Region

     Shift selected lines left by the indent width (default 4 spaces).

Comment Out Region

     Insert ## in front of selected lines.

Uncomment Region

     Remove leading # or ## from selected lines.

Tabify Region

     Turn 'leading' stretches of spaces into tabs.  (Note: We recommend
     using 4 space blocks to indent Python code.)

Untabify Region

     Turn 'all' tabs into the correct number of spaces.

Toggle Tabs

     Open a dialog to switch between indenting with spaces and tabs.

New Indent Width

     Open a dialog to change indent width.  The accepted default by the
     Python community is 4 spaces.

Strip Trailing Whitespace

     Remove trailing space and other whitespace characters after the
     last non-whitespace character of a line by applying *note
     str.rstrip(): 16b8. to each line, including lines within multiline
     strings.  Except for Shell windows, remove extra newlines at the
     end of the file.


File: python.info,  Node: Run menu Editor window only,  Next: Shell menu Shell window only,  Prev: Format menu Editor window only,  Up: Menus

5.25.9.5 Run menu (Editor window only)
......................................

Run Module

     Do *note Check Module: 43d5.  If no error, restart the shell to
     clean the environment, then execute the module.  Output is
     displayed in the Shell window.  Note that output requires use of
     ‘print’ or ‘write’.  When execution is complete, the Shell retains
     focus and displays a prompt.  At this point, one may interactively
     explore the result of execution.  This is similar to executing a
     file with ‘python -i file’ at a command line.

Run… Customized

     Same as *note Run Module: 43d4, but run the module with customized
     settings.  'Command Line Arguments' extend *note sys.argv: 146c. as
     if passed on a command line.  The module can be run in the Shell
     without restarting.

Check Module

     Check the syntax of the module currently open in the Editor window.
     If the module has not been saved IDLE will either prompt the user
     to save or autosave, as selected in the General tab of the Idle
     Settings dialog.  If there is a syntax error, the approximate
     location is indicated in the Editor window.

Python Shell

     Open or wake up the Python Shell window.


File: python.info,  Node: Shell menu Shell window only,  Next: Debug menu Shell window only,  Prev: Run menu Editor window only,  Up: Menus

5.25.9.6 Shell menu (Shell window only)
.......................................

View Last Restart

     Scroll the shell window to the last Shell restart.

Restart Shell

     Restart the shell to clean the environment and reset display and
     exception handling.

Previous History

     Cycle through earlier commands in history which match the current
     entry.

Next History

     Cycle through later commands in history which match the current
     entry.

Interrupt Execution

     Stop a running program.


File: python.info,  Node: Debug menu Shell window only,  Next: Options menu Shell and Editor,  Prev: Shell menu Shell window only,  Up: Menus

5.25.9.7 Debug menu (Shell window only)
.......................................

Go to File/Line

     Look on the current line.  with the cursor, and the line above for
     a filename and line number.  If found, open the file if not already
     open, and show the line.  Use this to view source lines referenced
     in an exception traceback and lines found by Find in Files.  Also
     available in the context menu of the Shell window and Output
     windows.

Debugger (toggle)

     When activated, code entered in the Shell or run from an Editor
     will run under the debugger.  In the Editor, breakpoints can be set
     with the context menu.  This feature is still incomplete and
     somewhat experimental.

Stack Viewer

     Show the stack traceback of the last exception in a tree widget,
     with access to locals and globals.

Auto-open Stack Viewer

     Toggle automatically opening the stack viewer on an unhandled
     exception.


File: python.info,  Node: Options menu Shell and Editor,  Next: Window menu Shell and Editor,  Prev: Debug menu Shell window only,  Up: Menus

5.25.9.8 Options menu (Shell and Editor)
........................................

Configure IDLE

     Open a configuration dialog and change preferences for the
     following: fonts, indentation, keybindings, text color themes,
     startup windows and size, additional help sources, and extensions.
     On macOS, open the configuration dialog by selecting Preferences in
     the application menu.  For more details, see *note Setting
     preferences: 43db. under Help and preferences.

Most configuration options apply to all windows or all future windows.
The option items below only apply to the active window.

Show/Hide Code Context (Editor Window only)

     Open a pane at the top of the edit window which shows the block
     context of the code which has scrolled above the top of the window.
     See *note Code Context: 43dc. in the Editing and Navigation section
     below.

Show/Hide Line Numbers (Editor Window only)

     Open a column to the left of the edit window which shows the number
     of each line of text.  The default is off, which may be changed in
     the preferences (see *note Setting preferences: 43db.).

Zoom/Restore Height

     Toggles the window between normal size and maximum height.  The
     initial size defaults to 40 lines by 80 chars unless changed on the
     General tab of the Configure IDLE dialog.  The maximum height for a
     screen is determined by momentarily maximizing a window the first
     time one is zoomed on the screen.  Changing screen settings may
     invalidate the saved height.  This toggle has no effect when a
     window is maximized.


File: python.info,  Node: Window menu Shell and Editor,  Next: Help menu Shell and Editor,  Prev: Options menu Shell and Editor,  Up: Menus

5.25.9.9 Window menu (Shell and Editor)
.......................................

Lists the names of all open windows; select one to bring it to the
foreground (deiconifying it if necessary).


File: python.info,  Node: Help menu Shell and Editor,  Next: Context menus,  Prev: Window menu Shell and Editor,  Up: Menus

5.25.9.10 Help menu (Shell and Editor)
......................................

About IDLE

     Display version, copyright, license, credits, and more.

IDLE Help

     Display this IDLE document, detailing the menu options, basic
     editing and navigation, and other tips.

Python Docs

     Access local Python documentation, if installed, or start a web
     browser and open docs.python.org showing the latest Python
     documentation.

Turtle Demo

     Run the turtledemo module with example Python code and turtle
     drawings.

Additional help sources may be added here with the Configure IDLE dialog
under the General tab.  See the *note Help sources: 43df. subsection
below for more on Help menu choices.


File: python.info,  Node: Context menus,  Prev: Help menu Shell and Editor,  Up: Menus

5.25.9.11 Context menus
.......................

Open a context menu by right-clicking in a window (Control-click on
macOS). Context menus have the standard clipboard functions also on the
Edit menu.

Cut

     Copy selection into the system-wide clipboard; then delete the
     selection.

Copy

     Copy selection into the system-wide clipboard.

Paste

     Insert contents of the system-wide clipboard into the current
     window.

Editor windows also have breakpoint functions.  Lines with a breakpoint
set are specially marked.  Breakpoints only have an effect when running
under the debugger.  Breakpoints for a file are saved in the user’s
‘.idlerc’ directory.

Set Breakpoint

     Set a breakpoint on the current line.

Clear Breakpoint

     Clear the breakpoint on that line.

Shell and Output windows also have the following.

Go to file/line

     Same as in Debug menu.

The Shell window also has an output squeezing facility explained in the
'Python Shell window' subsection below.

Squeeze

     If the cursor is over an output line, squeeze all the output
     between the code above and the prompt below down to a “Squeezed
     text” label.


File: python.info,  Node: Editing and Navigation,  Next: Startup and Code Execution,  Prev: Menus,  Up: IDLE — Python editor and shell<2>

5.25.9.12 Editing and Navigation
................................

* Menu:

* Editor windows::
* Key bindings::
* Automatic indentation::
* Search and Replace::
* Completions::
* Calltips::
* Format block::
* Code Context::
* Shell window::
* Text colors::


File: python.info,  Node: Editor windows,  Next: Key bindings,  Up: Editing and Navigation

5.25.9.13 Editor windows
........................

IDLE may open editor windows when it starts, depending on settings and
how you start IDLE. Thereafter, use the File menu.  There can be only
one open editor window for a given file.

The title bar contains the name of the file, the full path, and the
version of Python and IDLE running the window.  The status bar contains
the line number (“Ln”) and column number (“Col”).  Line numbers start
with 1; column numbers with 0.

IDLE assumes that files with a known .py* extension contain Python code
and that other files do not.  Run Python code with the Run menu.


File: python.info,  Node: Key bindings,  Next: Automatic indentation,  Prev: Editor windows,  Up: Editing and Navigation

5.25.9.14 Key bindings
......................

The IDLE insertion cursor is a thin vertical bar between character
positions.  When characters are entered, the insertion cursor and
everything to its right moves right one character and the new character
is entered in the new space.

Several non-character keys move the cursor and possibly delete
characters.  Deletion does not puts text on the clipboard, but IDLE has
an undo list.  Wherever this doc discusses keys, “C” refers to the
‘Control’ key on Windows and Unix and the ‘Command’ key on macOS. (And
all such discussions assume that the keys have not been re-bound to
something else.)

   * Arrow keys move the cursor one character or line.

   * ‘C’-‘LeftArrow’ and ‘C’-‘RightArrow’ moves left or right one word.

   * ‘Home’ and ‘End’ go to the beginning or end of the line.

   * ‘Page Up’ and ‘Page Down’ go up or down one screen.

   * ‘C’-‘Home’ and ‘C’-‘End’ go to beginning or end of the file.

   * ‘Backspace’ and ‘Del’ (or ‘C’-‘d’) delete the previous or next
     character.

   * ‘C’-‘Backspace’ and ‘C’-‘Del’ delete one word left or right.

   * ‘C’-‘k’ deletes (“kills”) everything to the right.

Standard keybindings (like ‘C’-‘c’ to copy and ‘C’-‘v’ to paste) may
work.  Keybindings are selected in the Configure IDLE dialog.


File: python.info,  Node: Automatic indentation,  Next: Search and Replace,  Prev: Key bindings,  Up: Editing and Navigation

5.25.9.15 Automatic indentation
...............................

After a block-opening statement, the next line is indented by 4 spaces
(in the Python Shell window by one tab).  After certain keywords (break,
return etc.)  the next line is dedented.  In leading indentation,
‘Backspace’ deletes up to 4 spaces if they are there.  ‘Tab’ inserts
spaces (in the Python Shell window one tab), number depends on Indent
width.  Currently, tabs are restricted to four spaces due to Tcl/Tk
limitations.

See also the indent/dedent region commands on the *note Format menu:
43d0.


File: python.info,  Node: Search and Replace,  Next: Completions,  Prev: Automatic indentation,  Up: Editing and Navigation

5.25.9.16 Search and Replace
............................

Any selection becomes a search target.  However, only selections within
a line work because searches are only performed within lines with the
terminal newline removed.  If ‘[x] Regular expression’ is checked, the
target is interpreted according to the Python re module.


File: python.info,  Node: Completions,  Next: Calltips,  Prev: Search and Replace,  Up: Editing and Navigation

5.25.9.17 Completions
.....................

Completions are supplied, when requested and available, for module
names, attributes of classes or functions, or filenames.  Each request
method displays a completion box with existing names.  (See tab
completions below for an exception.)  For any box, change the name being
completed and the item highlighted in the box by typing and deleting
characters; by hitting ‘Up’, ‘Down’, ‘PageUp’, ‘PageDown’, ‘Home’, and
‘End’ keys; and by a single click within the box.  Close the box with
‘Escape’, ‘Enter’, and double ‘Tab’ keys or clicks outside the box.  A
double click within the box selects and closes.

One way to open a box is to type a key character and wait for a
predefined interval.  This defaults to 2 seconds; customize it in the
settings dialog.  (To prevent auto popups, set the delay to a large
number of milliseconds, such as 100000000.)  For imported module names
or class or function attributes, type “.”.  For filenames in the root
directory, type *note os.sep: 87b. or *note os.altsep: 87c. immediately
after an opening quote.  (On Windows, one can specify a drive first.)
Move into subdirectories by typing a directory name and a separator.

Instead of waiting, or after a box is closed, open a completion box
immediately with Show Completions on the Edit menu.  The default hot key
is ‘C’-‘space’.  If one types a prefix for the desired name before
opening the box, the first match or near miss is made visible.  The
result is the same as if one enters a prefix after the box is displayed.
Show Completions after a quote completes filenames in the current
directory instead of a root directory.

Hitting ‘Tab’ after a prefix usually has the same effect as Show
Completions.  (With no prefix, it indents.)  However, if there is only
one match to the prefix, that match is immediately added to the editor
text without opening a box.

Invoking “Show Completions”, or hitting ‘Tab’ after a prefix, outside of
a string and without a preceding “.” opens a box with keywords, builtin
names, and available module-level names.

When editing code in an editor (as oppose to Shell), increase the
available module-level names by running your code and not restarting the
Shell thereafter.  This is especially useful after adding imports at the
top of a file.  This also increases possible attribute completions.

Completion boxes initially exclude names beginning with “_” or, for
modules, not included in “__all__”.  The hidden names can be accessed by
typing “_” after “.”, either before or after the box is opened.


File: python.info,  Node: Calltips,  Next: Format block,  Prev: Completions,  Up: Editing and Navigation

5.25.9.18 Calltips
..................

A calltip is shown automatically when one types ‘(’ after the name of an
'accessible' function.  A function name expression may include dots and
subscripts.  A calltip remains until it is clicked, the cursor is moved
out of the argument area, or ‘)’ is typed.  Whenever the cursor is in
the argument part of a definition, select Edit and «Show Call Tip» on
the menu or enter its shortcut to display a calltip.

The calltip consists of the function’s signature and docstring up to the
latter’s first blank line or the fifth non-blank line.  (Some builtin
functions lack an accessible signature.)  A “/” or “*” in the signature
indicates that the preceding or following arguments are passed by
position or name (keyword) only.  Details are subject to change.

In Shell, the accessible functions depends on what modules have been
imported into the user process, including those imported by Idle itself,
and which definitions have been run, all since the last restart.

For example, restart the Shell and enter ‘itertools.count(’.  A calltip
appears because Idle imports itertools into the user process for its own
use.  (This could change.)  Enter ‘turtle.write(’ and nothing appears.
Idle does not itself import turtle.  The menu entry and shortcut also do
nothing.  Enter ‘import turtle’.  Thereafter, ‘turtle.write(’ will
display a calltip.

In an editor, import statements have no effect until one runs the file.
One might want to run a file after writing import statements, after
adding function definitions, or after opening an existing file.


File: python.info,  Node: Format block,  Next: Code Context,  Prev: Calltips,  Up: Editing and Navigation

5.25.9.19 Format block
......................

Reformat Paragraph rewraps a block (“paragraph”) of contiguous equally
indented non-blank comments, a similar block of text within a multiline
string, or a selected subset of either.  If needed, add a blank line to
separate string from code.  Partial lines in a selection expand to
complete lines.  The resulting lines have the same indent as before but
have maximum total length of N columns (characters).  Change the default
N of 72 on the Window tab of IDLE Settings.


File: python.info,  Node: Code Context,  Next: Shell window,  Prev: Format block,  Up: Editing and Navigation

5.25.9.20 Code Context
......................

Within an editor window containing Python code, code context can be
toggled in order to show or hide a pane at the top of the window.  When
shown, this pane freezes the opening lines for block code, such as those
beginning with ‘class’, ‘def’, or ‘if’ keywords, that would have
otherwise scrolled out of view.  The size of the pane will be expanded
and contracted as needed to show the all current levels of context, up
to the maximum number of lines defined in the Configure IDLE dialog
(which defaults to 15).  If there are no current context lines and the
feature is toggled on, a single blank line will display.  Clicking on a
line in the context pane will move that line to the top of the editor.

The text and background colors for the context pane can be configured
under the Highlights tab in the Configure IDLE dialog.


File: python.info,  Node: Shell window,  Next: Text colors,  Prev: Code Context,  Up: Editing and Navigation

5.25.9.21 Shell window
......................

In IDLE’s Shell, enter, edit, and recall complete statements.  (Most
consoles and terminals only work with a single physical line at a time).

Submit a single-line statement for execution by hitting ‘Return’ with
the cursor anywhere on the line.  If a line is extended with Backslash
(‘\’), the cursor must be on the last physical line.  Submit a
multi-line compound statement by entering a blank line after the
statement.

When one pastes code into Shell, it is not compiled and possibly
executed until one hits ‘Return’, as specified above.  One may edit
pasted code first.  If one pastes more than one statement into Shell,
the result will be a *note SyntaxError: 18e. when multiple statements
are compiled as if they were one.

Lines containing ‘RESTART’ mean that the user execution process has been
re-started.  This occurs when the user execution process has crashed,
when one requests a restart on the Shell menu, or when one runs code in
an editor window.

The editing features described in previous subsections work when
entering code interactively.  IDLE’s Shell window also responds to the
following:

   * ‘C’-‘c’ attempts to interrupt statement execution (but may fail).

   * ‘C’-‘d’ closes Shell if typed at a ‘>>>’ prompt.

   * ‘Alt’-‘p’ and ‘Alt’-‘n’ (‘C’-‘p’ and ‘C’-‘n’ on macOS) retrieve to
     the current prompt the previous or next previously entered
     statement that matches anything already typed.

   * ‘Return’ while the cursor is on any previous statement appends the
     latter to anything already typed at the prompt.


File: python.info,  Node: Text colors,  Prev: Shell window,  Up: Editing and Navigation

5.25.9.22 Text colors
.....................

Idle defaults to black on white text, but colors text with special
meanings.  For the shell, these are shell output, shell error, user
output, and user error.  For Python code, at the shell prompt or in an
editor, these are keywords, builtin class and function names, names
following ‘class’ and ‘def’, strings, and comments.  For any text
window, these are the cursor (when present), found text (when possible),
and selected text.

IDLE also highlights the *note soft keywords: a0f. *note match: a10,
*note case: a10, and *note _: a11. in pattern-matching statements.
However, this highlighting is not perfect and will be incorrect in some
rare cases, including some ‘_’-s in ‘case’ patterns.

Text coloring is done in the background, so uncolorized text is
occasionally visible.  To change the color scheme, use the Configure
IDLE dialog Highlighting tab.  The marking of debugger breakpoint lines
in the editor and text in popups and dialogs is not user-configurable.


File: python.info,  Node: Startup and Code Execution,  Next: Help and Preferences,  Prev: Editing and Navigation,  Up: IDLE — Python editor and shell<2>

5.25.9.23 Startup and Code Execution
....................................

Upon startup with the ‘-s’ option, IDLE will execute the file referenced
by the environment variables ‘IDLESTARTUP’ or *note PYTHONSTARTUP: 1b8.
IDLE first checks for ‘IDLESTARTUP’; if ‘IDLESTARTUP’ is present the
file referenced is run.  If ‘IDLESTARTUP’ is not present, IDLE checks
for ‘PYTHONSTARTUP’.  Files referenced by these environment variables
are convenient places to store functions that are used frequently from
the IDLE shell, or for executing import statements to import common
modules.

In addition, ‘Tk’ also loads a startup file if it is present.  Note that
the Tk file is loaded unconditionally.  This additional file is
‘.Idle.py’ and is looked for in the user’s home directory.  Statements
in this file will be executed in the Tk namespace, so this file is not
useful for importing functions to be used from IDLE’s Python shell.

* Menu:

* Command-line usage: Command-line usage<5>.
* Startup failure::
* Running user code::
* User output in Shell::
* Developing tkinter applications::
* Running without a subprocess::


File: python.info,  Node: Command-line usage<5>,  Next: Startup failure,  Up: Startup and Code Execution

5.25.9.24 Command-line usage
............................

IDLE can be invoked from the command line with various options.  The
general syntax is:

     python -m idlelib [options] [file ...]

The following options are available:

 -- Option: -c <command>

     Run the specified Python command in the shell window.  For example,
     pass ‘-c "print('Hello, World!')"’.  On Windows, the outer quotes
     must be double quotes as shown.

 -- Option: -d

     Enable the debugger and open the shell window.

 -- Option: -e

     Open an editor window.

 -- Option: -h

     Print a help message with legal combinations of options and exit.

 -- Option: -i

     Open a shell window.

 -- Option: -r <file>

     Run the specified file in the shell window.

 -- Option: -s

     Run the startup file (as defined by the environment variables
     ‘IDLESTARTUP’ or *note PYTHONSTARTUP: 1b8.) before opening the
     shell window.

 -- Option: -t <title>

     Set the title of the shell window.

 -- Option: -

     Read and execute standard input in the shell window.  This option
     must be the last one before any arguments.

If arguments are provided:

   - If ‘-’, ‘-c’, or ‘-r’ is used, all arguments are placed in
     ‘sys.argv[1:]’, and ‘sys.argv[0]’ is set to ‘''’, ‘'-c'’, or ‘'-r'’
     respectively.  No editor window is opened, even if that is the
     default set in the 'Options' dialog.

   - Otherwise, arguments are treated as files to be opened for editing,
     and ‘sys.argv’ reflects the arguments passed to IDLE itself.


File: python.info,  Node: Startup failure,  Next: Running user code,  Prev: Command-line usage<5>,  Up: Startup and Code Execution

5.25.9.25 Startup failure
.........................

IDLE uses a socket to communicate between the IDLE GUI process and the
user code execution process.  A connection must be established whenever
the Shell starts or restarts.  (The latter is indicated by a divider
line that says “RESTART”).  If the user process fails to connect to the
GUI process, it usually displays a ‘Tk’ error box with a “cannot
connect” message that directs the user here.  It then exits.

One specific connection failure on Unix systems results from
misconfigured masquerading rules somewhere in a system’s network setup.
When IDLE is started from a terminal, one will see a message starting
with ‘** Invalid host:’.  The valid value is ‘127.0.0.1
(idlelib.rpc.LOCALHOST)’.  One can diagnose with ‘tcpconnect -irv
127.0.0.1 6543’ in one terminal window and ‘tcplisten <same args>’ in
another.

A common cause of failure is a user-written file with the same name as a
standard library module, such as 'random.py' and 'tkinter.py'.  When
such a file is located in the same directory as a file that is about to
be run, IDLE cannot import the stdlib file.  The current fix is to
rename the user file.

Though less common than in the past, an antivirus or firewall program
may stop the connection.  If the program cannot be taught to allow the
connection, then it must be turned off for IDLE to work.  It is safe to
allow this internal connection because no data is visible on external
ports.  A similar problem is a network mis-configuration that blocks
connections.

Python installation issues occasionally stop IDLE: multiple versions can
clash, or a single installation might need admin access.  If one undo
the clash, or cannot or does not want to run as admin, it might be
easiest to completely remove Python and start over.

A zombie pythonw.exe process could be a problem.  On Windows, use Task
Manager to check for one and stop it if there is.  Sometimes a restart
initiated by a program crash or Keyboard Interrupt (control-C) may fail
to connect.  Dismissing the error box or using Restart Shell on the
Shell menu may fix a temporary problem.

When IDLE first starts, it attempts to read user configuration files in
‘~/.idlerc/’ (~ is one’s home directory).  If there is a problem, an
error message should be displayed.  Leaving aside random disk glitches,
this can be prevented by never editing the files by hand.  Instead, use
the configuration dialog, under Options.  Once there is an error in a
user configuration file, the best solution may be to delete it and start
over with the settings dialog.

If IDLE quits with no message, and it was not started from a console,
try starting it from a console or terminal (‘python -m idlelib’) and see
if this results in an error message.

On Unix-based systems with tcl/tk older than ‘8.6.11’ (see ‘About IDLE’)
certain characters of certain fonts can cause a tk failure with a
message to the terminal.  This can happen either if one starts IDLE to
edit a file with such a character or later when entering such a
character.  If one cannot upgrade tcl/tk, then re-configure IDLE to use
a font that works better.


File: python.info,  Node: Running user code,  Next: User output in Shell,  Prev: Startup failure,  Up: Startup and Code Execution

5.25.9.26 Running user code
...........................

With rare exceptions, the result of executing Python code with IDLE is
intended to be the same as executing the same code by the default
method, directly with Python in a text-mode system console or terminal
window.  However, the different interface and operation occasionally
affect visible results.  For instance, ‘sys.modules’ starts with more
entries, and ‘threading.active_count()’ returns 2 instead of 1.

By default, IDLE runs user code in a separate OS process rather than in
the user interface process that runs the shell and editor.  In the
execution process, it replaces ‘sys.stdin’, ‘sys.stdout’, and
‘sys.stderr’ with objects that get input from and send output to the
Shell window.  The original values stored in ‘sys.__stdin__’,
‘sys.__stdout__’, and ‘sys.__stderr__’ are not touched, but may be
‘None’.

Sending print output from one process to a text widget in another is
slower than printing to a system terminal in the same process.  This has
the most effect when printing multiple arguments, as the string for each
argument, each separator, the newline are sent separately.  For
development, this is usually not a problem, but if one wants to print
faster in IDLE, format and join together everything one wants displayed
together and then print a single string.  Both format strings and *note
str.join(): 25e8. can help combine fields and lines.

IDLE’s standard stream replacements are not inherited by subprocesses
created in the execution process, whether directly by user code or by
modules such as multiprocessing.  If such subprocess use ‘input’ from
sys.stdin or ‘print’ or ‘write’ to sys.stdout or sys.stderr, IDLE should
be started in a command line window.  (On Windows, use ‘python’ or ‘py’
rather than ‘pythonw’ or ‘pyw’.)  The secondary subprocess will then be
attached to that window for input and output.

If ‘sys’ is reset by user code, such as with ‘importlib.reload(sys)’,
IDLE’s changes are lost and input from the keyboard and output to the
screen will not work correctly.

When Shell has the focus, it controls the keyboard and screen.  This is
normally transparent, but functions that directly access the keyboard
and screen will not work.  These include system-specific functions that
determine whether a key has been pressed and if so, which.

The IDLE code running in the execution process adds frames to the call
stack that would not be there otherwise.  IDLE wraps
‘sys.getrecursionlimit’ and ‘sys.setrecursionlimit’ to reduce the effect
of the additional stack frames.

When user code raises SystemExit either directly or by calling sys.exit,
IDLE returns to a Shell prompt instead of exiting.


File: python.info,  Node: User output in Shell,  Next: Developing tkinter applications,  Prev: Running user code,  Up: Startup and Code Execution

5.25.9.27 User output in Shell
..............................

When a program outputs text, the result is determined by the
corresponding output device.  When IDLE executes user code, ‘sys.stdout’
and ‘sys.stderr’ are connected to the display area of IDLE’s Shell.
Some of its features are inherited from the underlying Tk Text widget.
Others are programmed additions.  Where it matters, Shell is designed
for development rather than production runs.

For instance, Shell never throws away output.  A program that sends
unlimited output to Shell will eventually fill memory, resulting in a
memory error.  In contrast, some system text windows only keep the last
n lines of output.  A Windows console, for instance, keeps a
user-settable 1 to 9999 lines, with 300 the default.

A Tk Text widget, and hence IDLE’s Shell, displays characters
(codepoints) in the BMP (Basic Multilingual Plane) subset of Unicode.
Which characters are displayed with a proper glyph and which with a
replacement box depends on the operating system and installed fonts.
Tab characters cause the following text to begin after the next tab
stop.  (They occur every 8 “characters”).  Newline characters cause
following text to appear on a new line.  Other control characters are
ignored or displayed as a space, box, or something else, depending on
the operating system and font.  (Moving the text cursor through such
output with arrow keys may exhibit some surprising spacing behavior.)

     >>> s = 'a\tb\a<\x02><\r>\bc\nd'  # Enter 22 chars.
     >>> len(s)
     14
     >>> s  # Display repr(s)
     'a\tb\x07<\x02><\r>\x08c\nd'
     >>> print(s, end='')  # Display s as is.
     # Result varies by OS and font.  Try it.

The ‘repr’ function is used for interactive echo of expression values.
It returns an altered version of the input string in which control
codes, some BMP codepoints, and all non-BMP codepoints are replaced with
escape codes.  As demonstrated above, it allows one to identify the
characters in a string, regardless of how they are displayed.

Normal and error output are generally kept separate (on separate lines)
from code input and each other.  They each get different highlight
colors.

For SyntaxError tracebacks, the normal “^” marking where the error was
detected is replaced by coloring the text with an error highlight.  When
code run from a file causes other exceptions, one may right click on a
traceback line to jump to the corresponding line in an IDLE editor.  The
file will be opened if necessary.

Shell has a special facility for squeezing output lines down to a
“Squeezed text” label.  This is done automatically for output over N
lines (N = 50 by default).  N can be changed in the PyShell section of
the General page of the Settings dialog.  Output with fewer lines can be
squeezed by right clicking on the output.  This can be useful lines long
enough to slow down scrolling.

Squeezed output is expanded in place by double-clicking the label.  It
can also be sent to the clipboard or a separate view window by
right-clicking the label.


File: python.info,  Node: Developing tkinter applications,  Next: Running without a subprocess,  Prev: User output in Shell,  Up: Startup and Code Execution

5.25.9.28 Developing tkinter applications
.........................................

IDLE is intentionally different from standard Python in order to
facilitate development of tkinter programs.  Enter ‘import tkinter as
tk; root = tk.Tk()’ in standard Python and nothing appears.  Enter the
same in IDLE and a tk window appears.  In standard Python, one must also
enter ‘root.update()’ to see the window.  IDLE does the equivalent in
the background, about 20 times a second, which is about every 50
milliseconds.  Next enter ‘b = tk.Button(root, text='button');
b.pack()’.  Again, nothing visibly changes in standard Python until one
enters ‘root.update()’.

Most tkinter programs run ‘root.mainloop()’, which usually does not
return until the tk app is destroyed.  If the program is run with
‘python -i’ or from an IDLE editor, a ‘>>>’ shell prompt does not appear
until ‘mainloop()’ returns, at which time there is nothing left to
interact with.

When running a tkinter program from an IDLE editor, one can comment out
the mainloop call.  One then gets a shell prompt immediately and can
interact with the live application.  One just has to remember to
re-enable the mainloop call when running in standard Python.


File: python.info,  Node: Running without a subprocess,  Prev: Developing tkinter applications,  Up: Startup and Code Execution

5.25.9.29 Running without a subprocess
......................................

By default, IDLE executes user code in a separate subprocess via a
socket, which uses the internal loopback interface.  This connection is
not externally visible and no data is sent to or received from the
internet.  If firewall software complains anyway, you can ignore it.

If the attempt to make the socket connection fails, Idle will notify
you.  Such failures are sometimes transient, but if persistent, the
problem may be either a firewall blocking the connection or
misconfiguration of a particular system.  Until the problem is fixed,
one can run Idle with the -n command line switch.

If IDLE is started with the -n command line switch it will run in a
single process and will not create the subprocess which runs the RPC
Python execution server.  This can be useful if Python cannot create the
subprocess or the RPC socket interface on your platform.  However, in
this mode user code is not isolated from IDLE itself.  Also, the
environment is not restarted when Run/Run Module (F5) is selected.  If
your code has been modified, you must reload() the affected modules and
re-import any specific items (e.g.  from foo import baz) if the changes
are to take effect.  For these reasons, it is preferable to run IDLE
with the default subprocess if at all possible.

Deprecato dalla versione 3.4.


File: python.info,  Node: Help and Preferences,  Next: idlelib — implementation of IDLE application,  Prev: Startup and Code Execution,  Up: IDLE — Python editor and shell<2>

5.25.9.30 Help and Preferences
..............................

* Menu:

* Help sources::
* Setting preferences::
* IDLE on macOS::
* Extensions::


File: python.info,  Node: Help sources,  Next: Setting preferences,  Up: Help and Preferences

5.25.9.31 Help sources
......................

Help menu entry «IDLE Help» displays a formatted html version of the
IDLE chapter of the Library Reference.  The result, in a read-only
tkinter text window, is close to what one sees in a web browser.
Navigate through the text with a mousewheel, the scrollbar, or up and
down arrow keys held down.  Or click the TOC (Table of Contents) button
and select a section header in the opened box.

Help menu entry «Python Docs» opens the extensive sources of help,
including tutorials, available at ‘docs.python.org/x.y’, where “x.y” is
the currently running Python version.  If your system has an off-line
copy of the docs (this may be an installation option), that will be
opened instead.

Selected URLs can be added or removed from the help menu at any time
using the General tab of the Configure IDLE dialog.


File: python.info,  Node: Setting preferences,  Next: IDLE on macOS,  Prev: Help sources,  Up: Help and Preferences

5.25.9.32 Setting preferences
.............................

The font preferences, highlighting, keys, and general preferences can be
changed via Configure IDLE on the Option menu.  Non-default user
settings are saved in a ‘.idlerc’ directory in the user’s home
directory.  Problems caused by bad user configuration files are solved
by editing or deleting one or more of the files in ‘.idlerc’.

On the Font tab, see the text sample for the effect of font face and
size on multiple characters in multiple languages.  Edit the sample to
add other characters of personal interest.  Use the sample to select
monospaced fonts.  If particular characters have problems in Shell or an
editor, add them to the top of the sample and try changing first size
and then font.

On the Highlights and Keys tab, select a built-in or custom color theme
and key set.  To use a newer built-in color theme or key set with older
IDLEs, save it as a new custom theme or key set and it well be
accessible to older IDLEs.


File: python.info,  Node: IDLE on macOS,  Next: Extensions,  Prev: Setting preferences,  Up: Help and Preferences

5.25.9.33 IDLE on macOS
.......................

Under System Preferences: Dock, one can set «Prefer tabs when opening
documents» to «Always».  This setting is not compatible with the
tk/tkinter GUI framework used by IDLE, and it breaks a few IDLE
features.


File: python.info,  Node: Extensions,  Prev: IDLE on macOS,  Up: Help and Preferences

5.25.9.34 Extensions
....................

IDLE contains an extension facility.  Preferences for extensions can be
changed with the Extensions tab of the preferences dialog.  See the
beginning of config-extensions.def in the idlelib directory for further
information.  The only current default extension is zzdummy, an example
also used for testing.


File: python.info,  Node: idlelib — implementation of IDLE application,  Prev: Help and Preferences,  Up: IDLE — Python editor and shell<2>

5.25.9.35 idlelib — implementation of IDLE application
......................................................

'Source code:' Lib/idlelib(1)

__________________________________________________________________

The Lib/idlelib package implements the IDLE application.  See the rest
of this page for how to use IDLE.

The files in idlelib are described in idlelib/README.txt.  Access it
either in idlelib or click Help => About IDLE on the IDLE menu.  This
file also maps IDLE menu items to the code that implements the item.
Except for files listed under “Startup”, the idlelib code is “private”
in sense that feature changes can be backported (see PEP 434(2)).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/idlelib

   (2) https://peps.python.org/pep-0434/


File: python.info,  Node: turtle — Turtle graphics,  Prev: IDLE — Python editor and shell<2>,  Up: Graphical user interfaces with Tk

5.25.10 ‘turtle’ — Turtle graphics
----------------------------------

'Source code:' Lib/turtle.py(1)

__________________________________________________________________

* Menu:

* Introduction: Introduction<11>.
* Get started::
* Tutorial: Tutorial<4>.
* How to…::
* Turtle graphics reference::
* Methods of RawTurtle/Turtle and corresponding functions::
* Methods of TurtleScreen/Screen and corresponding functions::
* Public classes::
* Explanation: Explanation<2>.
* Help and configuration::
* turtledemo — Demo scripts::
* Changes since Python 2.6: Changes since Python 2 6.
* Changes since Python 3.0: Changes since Python 3 0.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/turtle.py


File: python.info,  Node: Introduction<11>,  Next: Get started,  Up: turtle — Turtle graphics

5.25.10.1 Introduction
......................

Turtle graphics is an implementation of the popular geometric drawing
tools introduced in Logo(1), developed by Wally Feurzeig, Seymour Papert
and Cynthia Solomon in 1967.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Turtle_(robot)


File: python.info,  Node: Get started,  Next: Tutorial<4>,  Prev: Introduction<11>,  Up: turtle — Turtle graphics

5.25.10.2 Get started
.....................

Imagine a robotic turtle starting at (0, 0) in the x-y plane.  After an
‘import turtle’, give it the command ‘turtle.forward(15)’, and it moves
(on-screen!)  15 pixels in the direction it is facing, drawing a line as
it moves.  Give it the command ‘turtle.right(25)’, and it rotates
in-place 25 degrees clockwise.

Turtle star
...........

Turtle can draw intricate shapes using programs that repeat simple
moves.

[image src="python-figures/turtle-star.png"]


In Python, turtle graphics provides a representation of a physical
«turtle» (a little robot with a pen) that draws on a sheet of paper on
the floor.

It’s an effective and well-proven way for learners to encounter
programming concepts and interaction with software, as it provides
instant, visible feedback.  It also provides convenient access to
graphical output in general.

Turtle drawing was originally created as an educational tool, to be used
by teachers in the classroom.  For the programmer who needs to produce
some graphical output it can be a way to do that without the overhead of
introducing more complex or external libraries into their work.


File: python.info,  Node: Tutorial<4>,  Next: How to…,  Prev: Get started,  Up: turtle — Turtle graphics

5.25.10.3 Tutorial
..................

New users should start here.  In this tutorial we’ll explore some of the
basics of turtle drawing.

* Menu:

* Starting a turtle environment::
* Basic drawing::
* Making algorithmic patterns::


File: python.info,  Node: Starting a turtle environment,  Next: Basic drawing,  Up: Tutorial<4>

5.25.10.4 Starting a turtle environment
.......................................

In a Python shell, import all the objects of the ‘turtle’ module:

     from turtle import *

If you run into a ‘No module named '_tkinter'’ error, you’ll have to
install the *note Tk interface package: f6. on your system.


File: python.info,  Node: Basic drawing,  Next: Making algorithmic patterns,  Prev: Starting a turtle environment,  Up: Tutorial<4>

5.25.10.5 Basic drawing
.......................

Send the turtle forward 100 steps:

     forward(100)

You should see (most likely, in a new window on your display) a line
drawn by the turtle, heading East.  Change the direction of the turtle,
so that it turns 120 degrees left (anti-clockwise):

     left(120)

Let’s continue by drawing a triangle:

     forward(100)
     left(120)
     forward(100)

Notice how the turtle, represented by an arrow, points in different
directions as you steer it.

Experiment with those commands, and also with ‘backward()’ and
‘right()’.

* Menu:

* Pen control::
* The turtle’s position::


File: python.info,  Node: Pen control,  Next: The turtle’s position,  Up: Basic drawing

5.25.10.6 Pen control
.....................

Try changing the color - for example, ‘color('blue')’ - and width of the
line - for example, ‘width(3)’ - and then drawing again.

You can also move the turtle around without drawing, by lifting up the
pen: ‘up()’ before moving.  To start drawing again, use ‘down()’.


File: python.info,  Node: The turtle’s position,  Prev: Pen control,  Up: Basic drawing

5.25.10.7 The turtle’s position
...............................

Send your turtle back to its starting-point (useful if it has
disappeared off-screen):

     home()

The home position is at the center of the turtle’s screen.  If you ever
need to know them, get the turtle’s x-y coordinates with:

     pos()

Home is at ‘(0, 0)’.

And after a while, it will probably help to clear the window so we can
start anew:

     clearscreen()


File: python.info,  Node: Making algorithmic patterns,  Prev: Basic drawing,  Up: Tutorial<4>

5.25.10.8 Making algorithmic patterns
.....................................

Using loops, it’s possible to build up geometric patterns:

     for steps in range(100):
         for c in ('blue', 'red', 'green'):
             color(c)
             forward(steps)
             right(30)

- which of course, are limited only by the imagination!

Let’s draw the star shape at the top of this page.  We want red lines,
filled in with yellow:

     color('red')
     fillcolor('yellow')

Just as ‘up()’ and ‘down()’ determine whether lines will be drawn,
filling can be turned on and off:

     begin_fill()

Next we’ll create a loop:

     while True:
         forward(200)
         left(170)
         if abs(pos()) < 1:
             break

‘abs(pos()) < 1’ is a good way to know when the turtle is back at its
home position.

Finally, complete the filling:

     end_fill()

(Note that filling only actually takes place when you give the
‘end_fill()’ command.)


File: python.info,  Node: How to…,  Next: Turtle graphics reference,  Prev: Tutorial<4>,  Up: turtle — Turtle graphics

5.25.10.9 How to…
.................

This section covers some typical turtle use-cases and approaches.

* Menu:

* Get started as quickly as possible::
* Automatically begin and end filling::
* Use the turtle module namespace::
* Use turtle graphics in a script::
* Use object-oriented turtle graphics::


File: python.info,  Node: Get started as quickly as possible,  Next: Automatically begin and end filling,  Up: How to…

5.25.10.10 Get started as quickly as possible
.............................................

One of the joys of turtle graphics is the immediate, visual feedback
that’s available from simple commands - it’s an excellent way to
introduce children to programming ideas, with a minimum of overhead (not
just children, of course).

The turtle module makes this possible by exposing all its basic
functionality as functions, available with ‘from turtle import *’.  The
*note turtle graphics tutorial: 4409. covers this approach.

It’s worth noting that many of the turtle commands also have even more
terse equivalents, such as ‘fd()’ for *note forward(): 35f5.  These are
especially useful when working with learners for whom typing is not a
skill.

     You’ll need to have the *note Tk interface package: f6. installed
     on your system for turtle graphics to work.  Be warned that this is
     not always straightforward, so check this in advance if you’re
     planning to use turtle graphics with a learner.


File: python.info,  Node: Automatically begin and end filling,  Next: Use the turtle module namespace,  Prev: Get started as quickly as possible,  Up: How to…

5.25.10.11 Automatically begin and end filling
..............................................

Starting with Python 3.14, you can use the *note fill(): 2a3. *note
context manager: 1e1. instead of *note begin_fill(): 4415. and *note
end_fill(): 4416. to automatically begin and end fill.  Here is an
example:

     with fill():
         for i in range(4):
             forward(100)
             right(90)

     forward(200)

The code above is equivalent to:

     begin_fill()
     for i in range(4):
         forward(100)
         right(90)
     end_fill()

     forward(200)


File: python.info,  Node: Use the turtle module namespace,  Next: Use turtle graphics in a script,  Prev: Automatically begin and end filling,  Up: How to…

5.25.10.12 Use the ‘turtle’ module namespace
............................................

Using ‘from turtle import *’ is convenient - but be warned that it
imports a rather large collection of objects, and if you’re doing
anything but turtle graphics you run the risk of a name conflict (this
becomes even more an issue if you’re using turtle graphics in a script
where other modules might be imported).

The solution is to use ‘import turtle’ - ‘fd()’ becomes ‘turtle.fd()’,
‘width()’ becomes ‘turtle.width()’ and so on.  (If typing «turtle» over
and over again becomes tedious, use for example ‘import turtle as t’
instead.)


File: python.info,  Node: Use turtle graphics in a script,  Next: Use object-oriented turtle graphics,  Prev: Use the turtle module namespace,  Up: How to…

5.25.10.13 Use turtle graphics in a script
..........................................

It’s recommended to use the ‘turtle’ module namespace as described
immediately above, for example:

     import turtle as t
     from random import random

     for i in range(100):
         steps = int(random() * 100)
         angle = int(random() * 360)
         t.right(angle)
         t.fd(steps)

Another step is also required though - as soon as the script ends,
Python will also close the turtle’s window.  Add:

     t.mainloop()

to the end of the script.  The script will now wait to be dismissed and
will not exit until it is terminated, for example by closing the turtle
graphics window.


File: python.info,  Node: Use object-oriented turtle graphics,  Prev: Use turtle graphics in a script,  Up: How to…

5.25.10.14 Use object-oriented turtle graphics
..............................................

Vedi anche
..........

*note Explanation of the object-oriented interface: 441a.

Other than for very basic introductory purposes, or for trying things
out as quickly as possible, it’s more usual and much more powerful to
use the object-oriented approach to turtle graphics.  For example, this
allows multiple turtles on screen at once.

In this approach, the various turtle commands are methods of objects
(mostly of ‘Turtle’ objects).  You 'can' use the object-oriented
approach in the shell, but it would be more typical in a Python script.

The example above then becomes:

     from turtle import Turtle
     from random import random

     t = Turtle()
     for i in range(100):
         steps = int(random() * 100)
         angle = int(random() * 360)
         t.right(angle)
         t.fd(steps)

     t.screen.mainloop()

Note the last line.  ‘t.screen’ is an instance of the *note Screen:
441b. that a Turtle instance exists on; it’s created automatically along
with the turtle.

The turtle’s screen can be customised, for example:

     t.screen.title('Object-oriented turtle demo')
     t.screen.bgcolor("orange")


File: python.info,  Node: Turtle graphics reference,  Next: Methods of RawTurtle/Turtle and corresponding functions,  Prev: How to…,  Up: turtle — Turtle graphics

5.25.10.15 Turtle graphics reference
....................................

     Nota: In the following documentation the argument list for
     functions is given.  Methods, of course, have the additional first
     argument 'self' which is omitted here.

* Menu:

* Turtle methods::
* Methods of TurtleScreen/Screen::


File: python.info,  Node: Turtle methods,  Next: Methods of TurtleScreen/Screen,  Up: Turtle graphics reference

5.25.10.16 Turtle methods
.........................

Turtle motion

     Move and draw

               *note forward(): 35f5. | *note fd(): 441e.
               *note backward(): 441f. | *note bk(): 4420. | *note back(): 4421.
               *note right(): 4422. | *note rt(): 4423.
               *note left(): 4424. | *note lt(): 4425.
               *note goto(): 4426. | *note setpos(): 4427. | *note setposition(): 4428.
               *note teleport(): 1a7f.
               *note setx(): 4429.
               *note sety(): 442a.
               *note setheading(): 442b. | *note seth(): 442c.
               *note home(): 442d.
               *note circle(): 442e.
               *note dot(): 442f.
               *note stamp(): 4430.
               *note clearstamp(): 4431.
               *note clearstamps(): 4432.
               *note undo(): 4433.
               *note speed(): 4434.

     Tell Turtle’s state

               *note position(): 4435. | *note pos(): 4436.
               *note towards(): 4437.
               *note xcor(): 4438.
               *note ycor(): 4439.
               *note heading(): 443a.
               *note distance(): 443b.

     Setting and measurement

               *note degrees(): 443c.
               *note radians(): 443d.

Pen control

     Drawing state

               *note pendown(): 443e. | *note pd(): 443f. | *note down(): 4440.
               *note penup(): 4441. | *note pu(): 4442. | *note up(): 4443.
               *note pensize(): 4444. | *note width(): 4445.
               *note pen(): 4446.
               *note isdown(): 4447.

     Color control

               *note color(): 4448.
               *note pencolor(): 4449.
               *note fillcolor(): 444a.

     Filling

               *note filling(): 444b.
               *note fill(): 2a3.
               *note begin_fill(): 4415.
               *note end_fill(): 4416.

     More drawing control

               *note reset(): 444c.
               *note clear(): 444d.
               *note write(): 444e.

Turtle state

     Visibility

               *note showturtle(): 444f. | *note st(): 4450.
               *note hideturtle(): 4451. | *note ht(): 4452.
               *note isvisible(): 4453.

     Appearance

               *note shape(): 4454.
               *note resizemode(): 4455.
               *note shapesize(): 4456. | *note turtlesize(): 4457.
               *note shearfactor(): 4458.
               *note tiltangle(): 930.
               *note tilt(): 4459.
               *note shapetransform(): 445a.
               *note get_shapepoly(): 445b.

Using events

          *note onclick(): 445c.
          *note onrelease(): 445d.
          *note ondrag(): 445e.

Special Turtle methods

          *note poly(): 2a4.
          *note begin_poly(): 445f.
          *note end_poly(): 4460.
          *note get_poly(): 4461.
          *note clone(): 4462.
          *note getturtle(): 4463. | *note getpen(): 4464.
          *note getscreen(): 4465.
          *note setundobuffer(): 4466.
          *note undobufferentries(): 4467.


File: python.info,  Node: Methods of TurtleScreen/Screen,  Prev: Turtle methods,  Up: Turtle graphics reference

5.25.10.17 Methods of TurtleScreen/Screen
.........................................

Window control

          *note bgcolor(): 4469.
          *note bgpic(): 446a.
          *note clearscreen(): 446b.
          *note resetscreen(): 446c.
          *note screensize(): 446d.
          *note setworldcoordinates(): 446e.

Animation control

          *note no_animation(): 2a5.
          *note delay(): 446f.
          *note tracer(): 4470.
          *note update(): 4471.

Using screen events

          *note listen(): 4472.
          *note onkey(): 4473. | *note onkeyrelease(): 4474.
          *note onkeypress(): 4475.
          *note onclick(): 445c. | *note onscreenclick(): 4476.
          *note ontimer(): 4477.
          *note mainloop(): 4478. | *note done(): 4479.

Settings and special methods

          *note mode(): 447a.
          *note colormode(): 447b.
          *note getcanvas(): 447c.
          *note getshapes(): 447d.
          *note register_shape(): 447e. | *note addshape(): 447f.
          *note turtles(): 4480.
          *note window_height(): 4481.
          *note window_width(): 4482.

Input methods

          *note textinput(): 1c62.
          *note numinput(): 1c63.

Methods specific to Screen

          *note bye(): 4483.
          *note exitonclick(): 4484.
          *note save(): 1958.
          *note setup(): 4485.
          *note title(): 4486.


File: python.info,  Node: Methods of RawTurtle/Turtle and corresponding functions,  Next: Methods of TurtleScreen/Screen and corresponding functions,  Prev: Turtle graphics reference,  Up: turtle — Turtle graphics

5.25.10.18 Methods of RawTurtle/Turtle and corresponding functions
..................................................................

Most of the examples in this section refer to a Turtle instance called
‘turtle’.

* Menu:

* Turtle motion::
* Tell Turtle’s state::
* Settings for measurement::
* Pen control: Pen control<2>.
* Turtle state::
* Using events::
* Special Turtle methods::
* Compound shapes::


File: python.info,  Node: Turtle motion,  Next: Tell Turtle’s state,  Up: Methods of RawTurtle/Turtle and corresponding functions

5.25.10.19 Turtle motion
........................

 -- Funzione: turtle.forward (distance)
 -- Funzione: turtle.fd (distance)


     Parametri: ‘distance’ – a number (integer or float)

     Move the turtle forward by the specified 'distance', in the
     direction the turtle is headed.

          >>> turtle.position()
          (0.00,0.00)
          >>> turtle.forward(25)
          >>> turtle.position()
          (25.00,0.00)
          >>> turtle.forward(-75)
          >>> turtle.position()
          (-50.00,0.00)

 -- Funzione: turtle.back (distance)
 -- Funzione: turtle.bk (distance)
 -- Funzione: turtle.backward (distance)


     Parametri: ‘distance’ – a number

     Move the turtle backward by 'distance', opposite to the direction
     the turtle is headed.  Do not change the turtle’s heading.

          >>> turtle.position()
          (0.00,0.00)
          >>> turtle.backward(30)
          >>> turtle.position()
          (-30.00,0.00)

 -- Funzione: turtle.right (angle)
 -- Funzione: turtle.rt (angle)


     Parametri: ‘angle’ – a number (integer or float)

     Turn turtle right by 'angle' units.  (Units are by default degrees,
     but can be set via the *note degrees(): 443c. and *note radians():
     443d. functions.)  Angle orientation depends on the turtle mode,
     see *note mode(): 447a.

          >>> turtle.heading()
          22.0
          >>> turtle.right(45)
          >>> turtle.heading()
          337.0

 -- Funzione: turtle.left (angle)
 -- Funzione: turtle.lt (angle)


     Parametri: ‘angle’ – a number (integer or float)

     Turn turtle left by 'angle' units.  (Units are by default degrees,
     but can be set via the *note degrees(): 443c. and *note radians():
     443d. functions.)  Angle orientation depends on the turtle mode,
     see *note mode(): 447a.

          >>> turtle.heading()
          22.0
          >>> turtle.left(45)
          >>> turtle.heading()
          67.0

 -- Funzione: turtle.goto (x, y=None)
 -- Funzione: turtle.setpos (x, y=None)
 -- Funzione: turtle.setposition (x, y=None)


     Parametri:

        * ‘x’ – a number or a pair/vector of numbers

        * ‘y’ – a number or ‘None’

     If 'y' is ‘None’, 'x' must be a pair of coordinates or a *note
     Vec2D: 4489. (e.g.  as returned by *note pos(): 4436.).

     Move turtle to an absolute position.  If the pen is down, draw
     line.  Do not change the turtle’s orientation.

          >>> tp = turtle.pos()
          >>> tp
          (0.00,0.00)
          >>> turtle.setpos(60,30)
          >>> turtle.pos()
          (60.00,30.00)
          >>> turtle.setpos((20,80))
          >>> turtle.pos()
          (20.00,80.00)
          >>> turtle.setpos(tp)
          >>> turtle.pos()
          (0.00,0.00)

 -- Funzione: turtle.teleport (x, y=None, *, fill_gap=False)


     Parametri:

        * ‘x’ – a number or ‘None’

        * ‘y’ – a number or ‘None’

        * ‘fill_gap’ – a boolean

     Move turtle to an absolute position.  Unlike goto(x, y), a line
     will not be drawn.  The turtle’s orientation does not change.  If
     currently filling, the polygon(s) teleported from will be filled
     after leaving, and filling will begin again after teleporting.
     This can be disabled with fill_gap=True, which makes the imaginary
     line traveled during teleporting act as a fill barrier like in
     goto(x, y).

          >>> tp = turtle.pos()
          >>> tp
          (0.00,0.00)
          >>> turtle.teleport(60)
          >>> turtle.pos()
          (60.00,0.00)
          >>> turtle.teleport(y=10)
          >>> turtle.pos()
          (60.00,10.00)
          >>> turtle.teleport(20, 30)
          >>> turtle.pos()
          (20.00,30.00)

     Added in version 3.12.

 -- Funzione: turtle.setx (x)


     Parametri: ‘x’ – a number (integer or float)

     Set the turtle’s first coordinate to 'x', leave second coordinate
     unchanged.

          >>> turtle.position()
          (0.00,240.00)
          >>> turtle.setx(10)
          >>> turtle.position()
          (10.00,240.00)

 -- Funzione: turtle.sety (y)


     Parametri: ‘y’ – a number (integer or float)

     Set the turtle’s second coordinate to 'y', leave first coordinate
     unchanged.

          >>> turtle.position()
          (0.00,40.00)
          >>> turtle.sety(-10)
          >>> turtle.position()
          (0.00,-10.00)

 -- Funzione: turtle.setheading (to_angle)
 -- Funzione: turtle.seth (to_angle)


     Parametri: ‘to_angle’ – a number (integer or float)

     Set the orientation of the turtle to 'to_angle'.  Here are some
     common directions in degrees:

     standard mode           logo mode
                             
     -------------------------------------------------
                             
     0 - east                0 - north
                             
                             
     90 - north              90 - east
                             
                             
     180 - west              180 - south
                             
                             
     270 - south             270 - west
                             

          >>> turtle.setheading(90)
          >>> turtle.heading()
          90.0

 -- Funzione: turtle.home ()

     Move turtle to the origin – coordinates (0,0) – and set its heading
     to its start-orientation (which depends on the mode, see *note
     mode(): 447a.).

          >>> turtle.heading()
          90.0
          >>> turtle.position()
          (0.00,-10.00)
          >>> turtle.home()
          >>> turtle.position()
          (0.00,0.00)
          >>> turtle.heading()
          0.0

 -- Funzione: turtle.circle (radius, extent=None, steps=None)


     Parametri:

        * ‘radius’ – a number

        * ‘extent’ – a number (or ‘None’)

        * ‘steps’ – an integer (or ‘None’)

     Draw a circle with given 'radius'.  The center is 'radius' units
     left of the turtle; 'extent' – an angle – determines which part of
     the circle is drawn.  If 'extent' is not given, draw the entire
     circle.  If 'extent' is not a full circle, one endpoint of the arc
     is the current pen position.  Draw the arc in counterclockwise
     direction if 'radius' is positive, otherwise in clockwise
     direction.  Finally the direction of the turtle is changed by the
     amount of 'extent'.

     As the circle is approximated by an inscribed regular polygon,
     'steps' determines the number of steps to use.  If not given, it
     will be calculated automatically.  May be used to draw regular
     polygons.

          >>> turtle.home()
          >>> turtle.position()
          (0.00,0.00)
          >>> turtle.heading()
          0.0
          >>> turtle.circle(50)
          >>> turtle.position()
          (-0.00,0.00)
          >>> turtle.heading()
          0.0
          >>> turtle.circle(120, 180)  # draw a semicircle
          >>> turtle.position()
          (0.00,240.00)
          >>> turtle.heading()
          180.0

 -- Funzione: turtle.dot ()

 -- Funzione: turtle.dot (size)

 -- Funzione: turtle.dot (color, /)

 -- Funzione: turtle.dot (size, color, /)

 -- Funzione: turtle.dot (size, r, g, b, /)


     Parametri:

        * ‘size’ – an integer >= 1 (if given)

        * ‘color’ – a colorstring or a numeric color tuple

     Draw a circular dot with diameter 'size', using 'color'.  If 'size'
     is not given, the maximum of ‘pensize+4’ and ‘2*pensize’ is used.

          >>> turtle.home()
          >>> turtle.dot()
          >>> turtle.fd(50); turtle.dot(20, "blue"); turtle.fd(50)
          >>> turtle.position()
          (100.00,-0.00)
          >>> turtle.heading()
          0.0

 -- Funzione: turtle.stamp ()

     Stamp a copy of the turtle shape onto the canvas at the current
     turtle position.  Return a stamp_id for that stamp, which can be
     used to delete it by calling ‘clearstamp(stamp_id)’.

          >>> turtle.color("blue")
          >>> stamp_id = turtle.stamp()
          >>> turtle.fd(50)

 -- Funzione: turtle.clearstamp (stampid)


     Parametri: ‘stampid’ – an integer, must be return value of previous
     *note stamp(): 4430. call

     Delete stamp with given 'stampid'.

          >>> turtle.position()
          (150.00,-0.00)
          >>> turtle.color("blue")
          >>> astamp = turtle.stamp()
          >>> turtle.fd(50)
          >>> turtle.position()
          (200.00,-0.00)
          >>> turtle.clearstamp(astamp)
          >>> turtle.position()
          (200.00,-0.00)

 -- Funzione: turtle.clearstamps (n=None)


     Parametri: ‘n’ – an integer (or ‘None’)

     Delete all or first/last 'n' of turtle’s stamps.  If 'n' is ‘None’,
     delete all stamps, if 'n' > 0 delete first 'n' stamps, else if 'n'
     < 0 delete last 'n' stamps.

          >>> for i in range(8):
          ...     unused_stamp_id = turtle.stamp()
          ...     turtle.fd(30)
          >>> turtle.clearstamps(2)
          >>> turtle.clearstamps(-2)
          >>> turtle.clearstamps()

 -- Funzione: turtle.undo ()

     Undo (repeatedly) the last turtle action(s).  Number of available
     undo actions is determined by the size of the undobuffer.

          >>> for i in range(4):
          ...     turtle.fd(50); turtle.lt(80)
          ...
          >>> for i in range(8):
          ...     turtle.undo()

 -- Funzione: turtle.speed (speed=None)


     Parametri: ‘speed’ – an integer in the range 0..10 or a speedstring
     (see below)

     Set the turtle’s speed to an integer value in the range 0..10.  If
     no argument is given, return current speed.

     If input is a number greater than 10 or smaller than 0.5, speed is
     set to 0.  Speedstrings are mapped to speedvalues as follows:

        * «fastest»: 0

        * «fast»: 10

        * «normal»: 6

        * «slow»: 3

        * «slowest»: 1

     Speeds from 1 to 10 enforce increasingly faster animation of line
     drawing and turtle turning.

     Attention: 'speed' = 0 means that 'no' animation takes place.
     forward/back makes turtle jump and likewise left/right make the
     turtle turn instantly.

          >>> turtle.speed()
          3
          >>> turtle.speed('normal')
          >>> turtle.speed()
          6
          >>> turtle.speed(9)
          >>> turtle.speed()
          9


File: python.info,  Node: Tell Turtle’s state,  Next: Settings for measurement,  Prev: Turtle motion,  Up: Methods of RawTurtle/Turtle and corresponding functions

5.25.10.20 Tell Turtle’s state
..............................

 -- Funzione: turtle.position ()
 -- Funzione: turtle.pos ()

     Return the turtle’s current location (x,y) (as a *note Vec2D: 4489.
     vector).

          >>> turtle.pos()
          (440.00,-0.00)

 -- Funzione: turtle.towards (x, y=None)


     Parametri:

        * ‘x’ – a number or a pair/vector of numbers or a turtle
          instance

        * ‘y’ – a number if 'x' is a number, else ‘None’

     Return the angle between the line from turtle position to position
     specified by (x,y), the vector or the other turtle.  This depends
     on the turtle’s start orientation which depends on the mode -
     «standard»/»world» or «logo».

          >>> turtle.goto(10, 10)
          >>> turtle.towards(0,0)
          225.0

 -- Funzione: turtle.xcor ()

     Return the turtle’s x coordinate.

          >>> turtle.home()
          >>> turtle.left(50)
          >>> turtle.forward(100)
          >>> turtle.pos()
          (64.28,76.60)
          >>> print(round(turtle.xcor(), 5))
          64.27876

 -- Funzione: turtle.ycor ()

     Return the turtle’s y coordinate.

          >>> turtle.home()
          >>> turtle.left(60)
          >>> turtle.forward(100)
          >>> print(turtle.pos())
          (50.00,86.60)
          >>> print(round(turtle.ycor(), 5))
          86.60254

 -- Funzione: turtle.heading ()

     Return the turtle’s current heading (value depends on the turtle
     mode, see *note mode(): 447a.).

          >>> turtle.home()
          >>> turtle.left(67)
          >>> turtle.heading()
          67.0

 -- Funzione: turtle.distance (x, y=None)


     Parametri:

        * ‘x’ – a number or a pair/vector of numbers or a turtle
          instance

        * ‘y’ – a number if 'x' is a number, else ‘None’

     Return the distance from the turtle to (x,y), the given vector, or
     the given other turtle, in turtle step units.

          >>> turtle.home()
          >>> turtle.distance(30,40)
          50.0
          >>> turtle.distance((30,40))
          50.0
          >>> joe = Turtle()
          >>> joe.forward(77)
          >>> turtle.distance(joe)
          77.0


File: python.info,  Node: Settings for measurement,  Next: Pen control<2>,  Prev: Tell Turtle’s state,  Up: Methods of RawTurtle/Turtle and corresponding functions

5.25.10.21 Settings for measurement
...................................

 -- Funzione: turtle.degrees (fullcircle=360.0)


     Parametri: ‘fullcircle’ – a number

     Set angle measurement units, i.e.  set number of «degrees» for a
     full circle.  Default value is 360 degrees.

          >>> turtle.home()
          >>> turtle.left(90)
          >>> turtle.heading()
          90.0

          >>> # Change angle measurement unit to grad (also known as gon,
          >>> # grade, or gradian and equals 1/100-th of the right angle.)
          >>> turtle.degrees(400.0)
          >>> turtle.heading()
          100.0
          >>> turtle.degrees(360)
          >>> turtle.heading()
          90.0

 -- Funzione: turtle.radians ()

     Set the angle measurement units to radians.  Equivalent to
     ‘degrees(2*math.pi)’.

          >>> turtle.home()
          >>> turtle.left(90)
          >>> turtle.heading()
          90.0
          >>> turtle.radians()
          >>> turtle.heading()
          1.5707963267948966


File: python.info,  Node: Pen control<2>,  Next: Turtle state,  Prev: Settings for measurement,  Up: Methods of RawTurtle/Turtle and corresponding functions

5.25.10.22 Pen control
......................

* Menu:

* Drawing state::
* Color control::
* Filling::
* More drawing control::


File: python.info,  Node: Drawing state,  Next: Color control,  Up: Pen control<2>

5.25.10.23 Drawing state
........................

 -- Funzione: turtle.pendown ()
 -- Funzione: turtle.pd ()
 -- Funzione: turtle.down ()

     Pull the pen down – drawing when moving.

 -- Funzione: turtle.penup ()
 -- Funzione: turtle.pu ()
 -- Funzione: turtle.up ()

     Pull the pen up – no drawing when moving.

 -- Funzione: turtle.pensize (width=None)
 -- Funzione: turtle.width (width=None)


     Parametri: ‘width’ – a positive number

     Set the line thickness to 'width' or return it.  If resizemode is
     set to «auto» and turtleshape is a polygon, that polygon is drawn
     with the same line thickness.  If no argument is given, the current
     pensize is returned.

          >>> turtle.pensize()
          1
          >>> turtle.pensize(10)   # from here on lines of width 10 are drawn

 -- Funzione: turtle.pen (pen=None, **pendict)


     Parametri:

        * ‘pen’ – a dictionary with some or all of the below listed keys

        * ‘pendict’ – one or more keyword-arguments with the below
          listed keys as keywords

     Return or set the pen’s attributes in a «pen-dictionary» with the
     following key/value pairs:

        * «shown»: True/False

        * «pendown»: True/False

        * «pencolor»: color-string or color-tuple

        * «fillcolor»: color-string or color-tuple

        * «pensize»: positive number

        * «speed»: number in range 0..10

        * «resizemode»: «auto» or «user» or «noresize»

        * «stretchfactor»: (positive number, positive number)

        * «outline»: positive number

        * «tilt»: number

     This dictionary can be used as argument for a subsequent call to
     *note pen(): 4446. to restore the former pen-state.  Moreover one
     or more of these attributes can be provided as keyword-arguments.
     This can be used to set several pen attributes in one statement.

          >>> turtle.pen(fillcolor="black", pencolor="red", pensize=10)
          >>> sorted(turtle.pen().items())
          [('fillcolor', 'black'), ('outline', 1), ('pencolor', 'red'),
           ('pendown', True), ('pensize', 10), ('resizemode', 'noresize'),
           ('shearfactor', 0.0), ('shown', True), ('speed', 9),
           ('stretchfactor', (1.0, 1.0)), ('tilt', 0.0)]
          >>> penstate=turtle.pen()
          >>> turtle.color("yellow", "")
          >>> turtle.penup()
          >>> sorted(turtle.pen().items())[:3]
          [('fillcolor', ''), ('outline', 1), ('pencolor', 'yellow')]
          >>> turtle.pen(penstate, fillcolor="green")
          >>> sorted(turtle.pen().items())[:3]
          [('fillcolor', 'green'), ('outline', 1), ('pencolor', 'red')]

 -- Funzione: turtle.isdown ()

     Return ‘True’ if pen is down, ‘False’ if it’s up.

          >>> turtle.penup()
          >>> turtle.isdown()
          False
          >>> turtle.pendown()
          >>> turtle.isdown()
          True


File: python.info,  Node: Color control,  Next: Filling,  Prev: Drawing state,  Up: Pen control<2>

5.25.10.24 Color control
........................

 -- Funzione: turtle.pencolor ()

 -- Funzione: turtle.pencolor (color, /)

 -- Funzione: turtle.pencolor (r, g, b, /)

     Return or set the pencolor.

     Four input formats are allowed:

     ‘pencolor()’

          Return the current pencolor as color specification string or
          as a tuple (see example).  May be used as input to another
          color/pencolor/fillcolor/bgcolor call.

     ‘pencolor(colorstring)’

          Set pencolor to 'colorstring', which is a Tk color
          specification string, such as ‘"red"’, ‘"yellow"’, or
          ‘"#33cc8c"’.

     ‘pencolor((r, g, b))’

          Set pencolor to the RGB color represented by the tuple of 'r',
          'g', and 'b'.  Each of 'r', 'g', and 'b' must be in the range
          0..colormode, where colormode is either 1.0 or 255 (see *note
          colormode(): 447b.).

     ‘pencolor(r, g, b)’

          Set pencolor to the RGB color represented by 'r', 'g', and
          'b'.  Each of 'r', 'g', and 'b' must be in the range
          0..colormode.

     If turtleshape is a polygon, the outline of that polygon is drawn
     with the newly set pencolor.

          >>> colormode()
          1.0
          >>> turtle.pencolor()
          'red'
          >>> turtle.pencolor("brown")
          >>> turtle.pencolor()
          'brown'
          >>> tup = (0.2, 0.8, 0.55)
          >>> turtle.pencolor(tup)
          >>> turtle.pencolor()
          (0.2, 0.8, 0.5490196078431373)
          >>> colormode(255)
          >>> turtle.pencolor()
          (51.0, 204.0, 140.0)
          >>> turtle.pencolor('#32c18f')
          >>> turtle.pencolor()
          (50.0, 193.0, 143.0)

 -- Funzione: turtle.fillcolor ()

 -- Funzione: turtle.fillcolor (color, /)

 -- Funzione: turtle.fillcolor (r, g, b, /)

     Return or set the fillcolor.

     Four input formats are allowed:

     ‘fillcolor()’

          Return the current fillcolor as color specification string,
          possibly in tuple format (see example).  May be used as input
          to another color/pencolor/fillcolor/bgcolor call.

     ‘fillcolor(colorstring)’

          Set fillcolor to 'colorstring', which is a Tk color
          specification string, such as ‘"red"’, ‘"yellow"’, or
          ‘"#33cc8c"’.

     ‘fillcolor((r, g, b))’

          Set fillcolor to the RGB color represented by the tuple of
          'r', 'g', and 'b'.  Each of 'r', 'g', and 'b' must be in the
          range 0..colormode, where colormode is either 1.0 or 255 (see
          *note colormode(): 447b.).

     ‘fillcolor(r, g, b)’

          Set fillcolor to the RGB color represented by 'r', 'g', and
          'b'.  Each of 'r', 'g', and 'b' must be in the range
          0..colormode.

     If turtleshape is a polygon, the interior of that polygon is drawn
     with the newly set fillcolor.

          >>> turtle.fillcolor("violet")
          >>> turtle.fillcolor()
          'violet'
          >>> turtle.pencolor()
          (50.0, 193.0, 143.0)
          >>> turtle.fillcolor((50, 193, 143))  # Integers, not floats
          >>> turtle.fillcolor()
          (50.0, 193.0, 143.0)
          >>> turtle.fillcolor('#ffffff')
          >>> turtle.fillcolor()
          (255.0, 255.0, 255.0)

 -- Funzione: turtle.color ()

 -- Funzione: turtle.color (color, /)

 -- Funzione: turtle.color (r, g, b, /)

 -- Funzione: turtle.color (pencolor, fillcolor, /)

     Return or set pencolor and fillcolor.

     Several input formats are allowed.  They use 0 to 3 arguments as
     follows:

     ‘color()’

          Return the current pencolor and the current fillcolor as a
          pair of color specification strings or tuples as returned by
          *note pencolor(): 4449. and *note fillcolor(): 444a.

     ‘color(colorstring)’, ‘color((r,g,b))’, ‘color(r,g,b)’

          Inputs as in *note pencolor(): 4449, set both, fillcolor and
          pencolor, to the given value.

     ‘color(colorstring1, colorstring2)’, ‘color((r1,g1,b1), (r2,g2,b2))’

          Equivalent to ‘pencolor(colorstring1)’ and
          ‘fillcolor(colorstring2)’ and analogously if the other input
          format is used.

     If turtleshape is a polygon, outline and interior of that polygon
     is drawn with the newly set colors.

          >>> turtle.color("red", "green")
          >>> turtle.color()
          ('red', 'green')
          >>> color("#285078", "#a0c8f0")
          >>> color()
          ((40.0, 80.0, 120.0), (160.0, 200.0, 240.0))

See also: Screen method *note colormode(): 447b.


File: python.info,  Node: Filling,  Next: More drawing control,  Prev: Color control,  Up: Pen control<2>

5.25.10.25 Filling
..................

 -- Funzione: turtle.filling ()

     Return fillstate (‘True’ if filling, ‘False’ else).

          >>> turtle.begin_fill()
          >>> if turtle.filling():
          ...    turtle.pensize(5)
          ... else:
          ...    turtle.pensize(3)

 -- Funzione: turtle.fill ()

     Fill the shape drawn in the ‘with turtle.fill():’ block.

          >>> turtle.color("black", "red")
          >>> with turtle.fill():
          ...     turtle.circle(80)

     Using ‘fill()’ is equivalent to adding the *note begin_fill():
     4415. before the fill-block and *note end_fill(): 4416. after the
     fill-block:

          >>> turtle.color("black", "red")
          >>> turtle.begin_fill()
          >>> turtle.circle(80)
          >>> turtle.end_fill()

     Added in version 3.14.

 -- Funzione: turtle.begin_fill ()

     To be called just before drawing a shape to be filled.

 -- Funzione: turtle.end_fill ()

     Fill the shape drawn after the last call to *note begin_fill():
     4415.

     Whether or not overlap regions for self-intersecting polygons or
     multiple shapes are filled depends on the operating system
     graphics, type of overlap, and number of overlaps.  For example,
     the Turtle star above may be either all yellow or have some white
     regions.

          >>> turtle.color("black", "red")
          >>> turtle.begin_fill()
          >>> turtle.circle(80)
          >>> turtle.end_fill()


File: python.info,  Node: More drawing control,  Prev: Filling,  Up: Pen control<2>

5.25.10.26 More drawing control
...............................

 -- Funzione: turtle.reset ()

     Delete the turtle’s drawings from the screen, re-center the turtle
     and set variables to the default values.

          >>> turtle.goto(0,-22)
          >>> turtle.left(100)
          >>> turtle.position()
          (0.00,-22.00)
          >>> turtle.heading()
          100.0
          >>> turtle.reset()
          >>> turtle.position()
          (0.00,0.00)
          >>> turtle.heading()
          0.0

 -- Funzione: turtle.clear ()

     Delete the turtle’s drawings from the screen.  Do not move turtle.
     State and position of the turtle as well as drawings of other
     turtles are not affected.

 -- Funzione: turtle.write (arg, move=False, align='left',
          font=('Arial', 8, 'normal'))


     Parametri:

        * ‘arg’ – object to be written to the TurtleScreen

        * ‘move’ – True/False

        * ‘align’ – one of the strings «left», «center» or right»

        * ‘font’ – a triple (fontname, fontsize, fonttype)

     Write text - the string representation of 'arg' - at the current
     turtle position according to 'align' («left», «center» or «right»)
     and with the given font.  If 'move' is true, the pen is moved to
     the bottom-right corner of the text.  By default, 'move' is
     ‘False’.

          >>> turtle.write("Home = ", True, align="center")
          >>> turtle.write((0,0), True)


File: python.info,  Node: Turtle state,  Next: Using events,  Prev: Pen control<2>,  Up: Methods of RawTurtle/Turtle and corresponding functions

5.25.10.27 Turtle state
.......................

* Menu:

* Visibility::
* Appearance::


File: python.info,  Node: Visibility,  Next: Appearance,  Up: Turtle state

5.25.10.28 Visibility
.....................

 -- Funzione: turtle.hideturtle ()
 -- Funzione: turtle.ht ()

     Make the turtle invisible.  It’s a good idea to do this while
     you’re in the middle of doing some complex drawing, because hiding
     the turtle speeds up the drawing observably.

          >>> turtle.hideturtle()

 -- Funzione: turtle.showturtle ()
 -- Funzione: turtle.st ()

     Make the turtle visible.

          >>> turtle.showturtle()

 -- Funzione: turtle.isvisible ()

     Return ‘True’ if the Turtle is shown, ‘False’ if it’s hidden.

          >>> turtle.hideturtle()
          >>> turtle.isvisible()
          False
          >>> turtle.showturtle()
          >>> turtle.isvisible()
          True


File: python.info,  Node: Appearance,  Prev: Visibility,  Up: Turtle state

5.25.10.29 Appearance
.....................

 -- Funzione: turtle.shape (name=None)


     Parametri: ‘name’ – a string which is a valid shapename

     Set turtle shape to shape with given 'name' or, if name is not
     given, return name of current shape.  Shape with 'name' must exist
     in the TurtleScreen’s shape dictionary.  Initially there are the
     following polygon shapes: «arrow», «turtle», «circle», «square»,
     «triangle», «classic».  To learn about how to deal with shapes see
     Screen method *note register_shape(): 447e.

          >>> turtle.shape()
          'classic'
          >>> turtle.shape("turtle")
          >>> turtle.shape()
          'turtle'

 -- Funzione: turtle.resizemode (rmode=None)


     Parametri: ‘rmode’ – one of the strings «auto», «user», «noresize»

     Set resizemode to one of the values: «auto», «user», «noresize».
     If 'rmode' is not given, return current resizemode.  Different
     resizemodes have the following effects:

        - «auto»: adapts the appearance of the turtle corresponding to
          the value of pensize.

        - «user»: adapts the appearance of the turtle according to the
          values of stretchfactor and outlinewidth (outline), which are
          set by *note shapesize(): 4456.

        - «noresize»: no adaption of the turtle’s appearance takes
          place.

     ‘resizemode("user")’ is called by *note shapesize(): 4456. when
     used with arguments.

          >>> turtle.resizemode()
          'noresize'
          >>> turtle.resizemode("auto")
          >>> turtle.resizemode()
          'auto'

 -- Funzione: turtle.shapesize (stretch_wid=None, stretch_len=None,
          outline=None)
 -- Funzione: turtle.turtlesize (stretch_wid=None, stretch_len=None,
          outline=None)


     Parametri:

        * ‘stretch_wid’ – positive number

        * ‘stretch_len’ – positive number

        * ‘outline’ – positive number

     Return or set the pen’s attributes x/y-stretchfactors and/or
     outline.  Set resizemode to «user».  If and only if resizemode is
     set to «user», the turtle will be displayed stretched according to
     its stretchfactors: 'stretch_wid' is stretchfactor perpendicular to
     its orientation, 'stretch_len' is stretchfactor in direction of its
     orientation, 'outline' determines the width of the shape’s outline.

          >>> turtle.shapesize()
          (1.0, 1.0, 1)
          >>> turtle.resizemode("user")
          >>> turtle.shapesize(5, 5, 12)
          >>> turtle.shapesize()
          (5, 5, 12)
          >>> turtle.shapesize(outline=8)
          >>> turtle.shapesize()
          (5, 5, 8)

 -- Funzione: turtle.shearfactor (shear=None)


     Parametri: ‘shear’ – number (optional)

     Set or return the current shearfactor.  Shear the turtleshape
     according to the given shearfactor shear, which is the tangent of
     the shear angle.  Do 'not' change the turtle’s heading (direction
     of movement).  If shear is not given: return the current
     shearfactor, i.  e.  the tangent of the shear angle, by which lines
     parallel to the heading of the turtle are sheared.

          >>> turtle.shape("circle")
          >>> turtle.shapesize(5,2)
          >>> turtle.shearfactor(0.5)
          >>> turtle.shearfactor()
          0.5

 -- Funzione: turtle.tilt (angle)


     Parametri: ‘angle’ – a number

     Rotate the turtleshape by 'angle' from its current tilt-angle, but
     do 'not' change the turtle’s heading (direction of movement).

          >>> turtle.reset()
          >>> turtle.shape("circle")
          >>> turtle.shapesize(5,2)
          >>> turtle.tilt(30)
          >>> turtle.fd(50)
          >>> turtle.tilt(30)
          >>> turtle.fd(50)

 -- Funzione: turtle.tiltangle (angle=None)


     Parametri: ‘angle’ – a number (optional)

     Set or return the current tilt-angle.  If angle is given, rotate
     the turtleshape to point in the direction specified by angle,
     regardless of its current tilt-angle.  Do 'not' change the turtle’s
     heading (direction of movement).  If angle is not given: return the
     current tilt-angle, i.  e.  the angle between the orientation of
     the turtleshape and the heading of the turtle (its direction of
     movement).

          >>> turtle.reset()
          >>> turtle.shape("circle")
          >>> turtle.shapesize(5,2)
          >>> turtle.tilt(45)
          >>> turtle.tiltangle()
          45.0

 -- Funzione: turtle.shapetransform (t11=None, t12=None, t21=None,
          t22=None)


     Parametri:

        * ‘t11’ – a number (optional)

        * ‘t12’ – a number (optional)

        * ‘t21’ – a number (optional)

        * ‘t12’ – a number (optional)

     Set or return the current transformation matrix of the turtle
     shape.

     If none of the matrix elements are given, return the transformation
     matrix as a tuple of 4 elements.  Otherwise set the given elements
     and transform the turtleshape according to the matrix consisting of
     first row t11, t12 and second row t21, t22.  The determinant t11 *
     t22 - t12 * t21 must not be zero, otherwise an error is raised.
     Modify stretchfactor, shearfactor and tiltangle according to the
     given matrix.

          >>> turtle = Turtle()
          >>> turtle.shape("square")
          >>> turtle.shapesize(4,2)
          >>> turtle.shearfactor(-0.5)
          >>> turtle.shapetransform()
          (4.0, -1.0, -0.0, 2.0)

 -- Funzione: turtle.get_shapepoly ()

     Return the current shape polygon as tuple of coordinate pairs.
     This can be used to define a new shape or components of a compound
     shape.

          >>> turtle.shape("square")
          >>> turtle.shapetransform(4, -1, 0, 2)
          >>> turtle.get_shapepoly()
          ((50, -20), (30, 20), (-50, 20), (-30, -20))


File: python.info,  Node: Using events,  Next: Special Turtle methods,  Prev: Turtle state,  Up: Methods of RawTurtle/Turtle and corresponding functions

5.25.10.30 Using events
.......................

 -- Funzione: turtle.onclick (fun, btn=1, add=None)


     Parametri:

        * ‘fun’ – a function with two arguments which will be called
          with the coordinates of the clicked point on the canvas

        * ‘btn’ – number of the mouse-button, defaults to 1 (left mouse
          button)

        * ‘add’ – ‘True’ or ‘False’ – if ‘True’, a new binding will be
          added, otherwise it will replace a former binding

     Bind 'fun' to mouse-click events on this turtle.  If 'fun' is
     ‘None’, existing bindings are removed.  Example for the anonymous
     turtle, i.e.  the procedural way:

          >>> def turn(x, y):
          ...     left(180)
          ...
          >>> onclick(turn)  # Now clicking into the turtle will turn it.
          >>> onclick(None)  # event-binding will be removed

 -- Funzione: turtle.onrelease (fun, btn=1, add=None)


     Parametri:

        * ‘fun’ – a function with two arguments which will be called
          with the coordinates of the clicked point on the canvas

        * ‘btn’ – number of the mouse-button, defaults to 1 (left mouse
          button)

        * ‘add’ – ‘True’ or ‘False’ – if ‘True’, a new binding will be
          added, otherwise it will replace a former binding

     Bind 'fun' to mouse-button-release events on this turtle.  If 'fun'
     is ‘None’, existing bindings are removed.

          >>> class MyTurtle(Turtle):
          ...     def glow(self,x,y):
          ...         self.fillcolor("red")
          ...     def unglow(self,x,y):
          ...         self.fillcolor("")
          ...
          >>> turtle = MyTurtle()
          >>> turtle.onclick(turtle.glow)     # clicking on turtle turns fillcolor red,
          >>> turtle.onrelease(turtle.unglow) # releasing turns it to transparent.

 -- Funzione: turtle.ondrag (fun, btn=1, add=None)


     Parametri:

        * ‘fun’ – a function with two arguments which will be called
          with the coordinates of the clicked point on the canvas

        * ‘btn’ – number of the mouse-button, defaults to 1 (left mouse
          button)

        * ‘add’ – ‘True’ or ‘False’ – if ‘True’, a new binding will be
          added, otherwise it will replace a former binding

     Bind 'fun' to mouse-move events on this turtle.  If 'fun' is
     ‘None’, existing bindings are removed.

     Remark: Every sequence of mouse-move-events on a turtle is preceded
     by a mouse-click event on that turtle.

          >>> turtle.ondrag(turtle.goto)

     Subsequently, clicking and dragging the Turtle will move it across
     the screen thereby producing handdrawings (if pen is down).


File: python.info,  Node: Special Turtle methods,  Next: Compound shapes,  Prev: Using events,  Up: Methods of RawTurtle/Turtle and corresponding functions

5.25.10.31 Special Turtle methods
.................................

 -- Funzione: turtle.poly ()

     Record the vertices of a polygon drawn in the ‘with turtle.poly():’
     block.  The first and last vertices will be connected.

          >>> with turtle.poly():
          ...     turtle.forward(100)
          ...     turtle.right(60)
          ...     turtle.forward(100)

     Added in version 3.14.

 -- Funzione: turtle.begin_poly ()

     Start recording the vertices of a polygon.  Current turtle position
     is first vertex of polygon.

 -- Funzione: turtle.end_poly ()

     Stop recording the vertices of a polygon.  Current turtle position
     is last vertex of polygon.  This will be connected with the first
     vertex.

 -- Funzione: turtle.get_poly ()

     Return the last recorded polygon.

          >>> turtle.home()
          >>> turtle.begin_poly()
          >>> turtle.fd(100)
          >>> turtle.left(20)
          >>> turtle.fd(30)
          >>> turtle.left(60)
          >>> turtle.fd(50)
          >>> turtle.end_poly()
          >>> p = turtle.get_poly()
          >>> register_shape("myFavouriteShape", p)

 -- Funzione: turtle.clone ()

     Create and return a clone of the turtle with same position, heading
     and turtle properties.

          >>> mick = Turtle()
          >>> joe = mick.clone()

 -- Funzione: turtle.getturtle ()
 -- Funzione: turtle.getpen ()

     Return the Turtle object itself.  Only reasonable use: as a
     function to return the «anonymous turtle»:

          >>> pet = getturtle()
          >>> pet.fd(50)
          >>> pet
          <turtle.Turtle object at 0x...>

 -- Funzione: turtle.getscreen ()

     Return the *note TurtleScreen: 4496. object the turtle is drawing
     on.  TurtleScreen methods can then be called for that object.

          >>> ts = turtle.getscreen()
          >>> ts
          <turtle._Screen object at 0x...>
          >>> ts.bgcolor("pink")

 -- Funzione: turtle.setundobuffer (size)


     Parametri: ‘size’ – an integer or ‘None’

     Set or disable undobuffer.  If 'size' is an integer, an empty
     undobuffer of given size is installed.  'size' gives the maximum
     number of turtle actions that can be undone by the *note undo():
     4433. method/function.  If 'size' is ‘None’, the undobuffer is
     disabled.

          >>> turtle.setundobuffer(42)

 -- Funzione: turtle.undobufferentries ()

     Return number of entries in the undobuffer.

          >>> while undobufferentries():
          ...     undo()


File: python.info,  Node: Compound shapes,  Prev: Special Turtle methods,  Up: Methods of RawTurtle/Turtle and corresponding functions

5.25.10.32 Compound shapes
..........................

To use compound turtle shapes, which consist of several polygons of
different color, you must use the helper class *note Shape: 4499.
explicitly as described below:

  1. Create an empty Shape object of type «compound».

  2. Add as many components to this object as desired, using the *note
     addcomponent(): 449a. method.

     For example:

          >>> s = Shape("compound")
          >>> poly1 = ((0,0),(10,-5),(0,10),(-10,-5))
          >>> s.addcomponent(poly1, "red", "blue")
          >>> poly2 = ((0,0),(10,-5),(-10,-5))
          >>> s.addcomponent(poly2, "blue", "red")

  3. Now add the Shape to the Screen’s shapelist and use it:

          >>> register_shape("myshape", s)
          >>> shape("myshape")

     Nota: The *note Shape: 4499. class is used internally by the *note
     register_shape(): 447e. method in different ways.  The application
     programmer has to deal with the Shape class 'only' when using
     compound shapes like shown above!


File: python.info,  Node: Methods of TurtleScreen/Screen and corresponding functions,  Next: Public classes,  Prev: Methods of RawTurtle/Turtle and corresponding functions,  Up: turtle — Turtle graphics

5.25.10.33 Methods of TurtleScreen/Screen and corresponding functions
.....................................................................

Most of the examples in this section refer to a TurtleScreen instance
called ‘screen’.

* Menu:

* Window control::
* Animation control::
* Using screen events::
* Input methods::
* Settings and special methods::
* Methods specific to Screen, not inherited from TurtleScreen: Methods specific to Screen not inherited from TurtleScreen.


File: python.info,  Node: Window control,  Next: Animation control,  Up: Methods of TurtleScreen/Screen and corresponding functions

5.25.10.34 Window control
.........................

 -- Funzione: turtle.bgcolor ()

 -- Funzione: turtle.bgcolor (color, /)

 -- Funzione: turtle.bgcolor (r, g, b, /)

     Return or set the background color of the TurtleScreen.

     Four input formats are allowed:

     ‘bgcolor()’

          Return the current background color as color specification
          string or as a tuple (see example).  May be used as input to
          another color/pencolor/fillcolor/bgcolor call.

     ‘bgcolor(colorstring)’

          Set the background color to 'colorstring', which is a Tk color
          specification string, such as ‘"red"’, ‘"yellow"’, or
          ‘"#33cc8c"’.

     ‘bgcolor((r, g, b))’

          Set the background color to the RGB color represented by the
          tuple of 'r', 'g', and 'b'.  Each of 'r', 'g', and 'b' must be
          in the range 0..colormode, where colormode is either 1.0 or
          255 (see *note colormode(): 447b.).

     ‘bgcolor(r, g, b)’

          Set the background color to the RGB color represented by 'r',
          'g', and 'b'.  Each of 'r', 'g', and 'b' must be in the range
          0..colormode.

          >>> screen.bgcolor("orange")
          >>> screen.bgcolor()
          'orange'
          >>> screen.bgcolor("#800080")
          >>> screen.bgcolor()
          (128.0, 0.0, 128.0)

 -- Funzione: turtle.bgpic (picname=None)


     Parametri: ‘picname’ – a string, name of an image file (PNG, GIF,
     PGM, and PPM) or ‘"nopic"’, or ‘None’

     Set background image or return name of current backgroundimage.  If
     'picname' is a filename, set the corresponding image as background.
     If 'picname' is ‘"nopic"’, delete background image, if present.  If
     'picname' is ‘None’, return the filename of the current
     backgroundimage.

          >>> screen.bgpic()
          'nopic'
          >>> screen.bgpic("landscape.gif")
          >>> screen.bgpic()
          "landscape.gif"

 -- Funzione: turtle.clear ()

          Nota: This TurtleScreen method is available as a global
          function only under the name ‘clearscreen’.  The global
          function ‘clear’ is a different one derived from the Turtle
          method ‘clear’.

 -- Funzione: turtle.clearscreen ()

     Delete all drawings and all turtles from the TurtleScreen.  Reset
     the now empty TurtleScreen to its initial state: white background,
     no background image, no event bindings and tracing on.

 -- Funzione: turtle.reset ()

          Nota: This TurtleScreen method is available as a global
          function only under the name ‘resetscreen’.  The global
          function ‘reset’ is another one derived from the Turtle method
          ‘reset’.

 -- Funzione: turtle.resetscreen ()

     Reset all Turtles on the Screen to their initial state.

 -- Funzione: turtle.screensize (canvwidth=None, canvheight=None,
          bg=None)


     Parametri:

        * ‘canvwidth’ – positive integer, new width of canvas in pixels

        * ‘canvheight’ – positive integer, new height of canvas in
          pixels

        * ‘bg’ – colorstring or color-tuple, new background color

     If no arguments are given, return current (canvaswidth,
     canvasheight).  Else resize the canvas the turtles are drawing on.
     Do not alter the drawing window.  To observe hidden parts of the
     canvas, use the scrollbars.  With this method, one can make visible
     those parts of a drawing which were outside the canvas before.

          >>> screen.screensize()
          (400, 300)
          >>> screen.screensize(2000,1500)
          >>> screen.screensize()
          (2000, 1500)

     e.g.  to search for an erroneously escaped turtle ;-)

 -- Funzione: turtle.setworldcoordinates (llx, lly, urx, ury)


     Parametri:

        * ‘llx’ – a number, x-coordinate of lower left corner of canvas

        * ‘lly’ – a number, y-coordinate of lower left corner of canvas

        * ‘urx’ – a number, x-coordinate of upper right corner of canvas

        * ‘ury’ – a number, y-coordinate of upper right corner of canvas

     Set up user-defined coordinate system and switch to mode «world» if
     necessary.  This performs a ‘screen.reset()’.  If mode «world» is
     already active, all drawings are redrawn according to the new
     coordinates.

     'ATTENTION': in user-defined coordinate systems angles may appear
     distorted.

          >>> screen.reset()
          >>> screen.setworldcoordinates(-50,-7.5,50,7.5)
          >>> for _ in range(72):
          ...     left(10)
          ...
          >>> for _ in range(8):
          ...     left(45); fd(2)   # a regular octagon


File: python.info,  Node: Animation control,  Next: Using screen events,  Prev: Window control,  Up: Methods of TurtleScreen/Screen and corresponding functions

5.25.10.35 Animation control
............................

 -- Funzione: turtle.no_animation ()

     Temporarily disable turtle animation.  The code written inside the
     ‘no_animation’ block will not be animated; once the code block is
     exited, the drawing will appear.

          >>> with screen.no_animation():
          ...     for dist in range(2, 400, 2):
          ...         fd(dist)
          ...         rt(90)

     Added in version 3.14.

 -- Funzione: turtle.delay (delay=None)


     Parametri: ‘delay’ – positive integer

     Set or return the drawing 'delay' in milliseconds.  (This is
     approximately the time interval between two consecutive canvas
     updates.)  The longer the drawing delay, the slower the animation.

     Optional argument:

          >>> screen.delay()
          10
          >>> screen.delay(5)
          >>> screen.delay()
          5

 -- Funzione: turtle.tracer (n=None, delay=None)


     Parametri:

        * ‘n’ – nonnegative integer

        * ‘delay’ – nonnegative integer

     Turn turtle animation on/off and set delay for update drawings.  If
     'n' is given, only each n-th regular screen update is really
     performed.  (Can be used to accelerate the drawing of complex
     graphics.)  When called without arguments, returns the currently
     stored value of n.  Second argument sets delay value (see *note
     delay(): 446f.).

          >>> screen.tracer(8, 25)
          >>> dist = 2
          >>> for i in range(200):
          ...     fd(dist)
          ...     rt(90)
          ...     dist += 2

 -- Funzione: turtle.update ()

     Perform a TurtleScreen update.  To be used when tracer is turned
     off.

See also the RawTurtle/Turtle method *note speed(): 4434.


File: python.info,  Node: Using screen events,  Next: Input methods,  Prev: Animation control,  Up: Methods of TurtleScreen/Screen and corresponding functions

5.25.10.36 Using screen events
..............................

 -- Funzione: turtle.listen (xdummy=None, ydummy=None)

     Set focus on TurtleScreen (in order to collect key-events).  Dummy
     arguments are provided in order to be able to pass *note listen():
     4472. to the onclick method.

 -- Funzione: turtle.onkey (fun, key)
 -- Funzione: turtle.onkeyrelease (fun, key)


     Parametri:

        * ‘fun’ – a function with no arguments or ‘None’

        * ‘key’ – a string: key (e.g.  «a») or key-symbol (e.g.
          «space»)

     Bind 'fun' to key-release event of key.  If 'fun' is ‘None’, event
     bindings are removed.  Remark: in order to be able to register
     key-events, TurtleScreen must have the focus.  (See method *note
     listen(): 4472.)

          >>> def f():
          ...     fd(50)
          ...     lt(60)
          ...
          >>> screen.onkey(f, "Up")
          >>> screen.listen()

 -- Funzione: turtle.onkeypress (fun, key=None)


     Parametri:

        * ‘fun’ – a function with no arguments or ‘None’

        * ‘key’ – a string: key (e.g.  «a») or key-symbol (e.g.
          «space»)

     Bind 'fun' to key-press event of key if key is given, or to any
     key-press-event if no key is given.  Remark: in order to be able to
     register key-events, TurtleScreen must have focus.  (See method
     *note listen(): 4472.)

          >>> def f():
          ...     fd(50)
          ...
          >>> screen.onkey(f, "Up")
          >>> screen.listen()

 -- Funzione: turtle.onclick (fun, btn=1, add=None)
 -- Funzione: turtle.onscreenclick (fun, btn=1, add=None)


     Parametri:

        * ‘fun’ – a function with two arguments which will be called
          with the coordinates of the clicked point on the canvas

        * ‘btn’ – number of the mouse-button, defaults to 1 (left mouse
          button)

        * ‘add’ – ‘True’ or ‘False’ – if ‘True’, a new binding will be
          added, otherwise it will replace a former binding

     Bind 'fun' to mouse-click events on this screen.  If 'fun' is
     ‘None’, existing bindings are removed.

     Example for a TurtleScreen instance named ‘screen’ and a Turtle
     instance named ‘turtle’:

          >>> screen.onclick(turtle.goto) # Subsequently clicking into the TurtleScreen will
          >>>                             # make the turtle move to the clicked point.
          >>> screen.onclick(None)        # remove event binding again

          Nota: This TurtleScreen method is available as a global
          function only under the name ‘onscreenclick’.  The global
          function ‘onclick’ is another one derived from the Turtle
          method ‘onclick’.

 -- Funzione: turtle.ontimer (fun, t=0)


     Parametri:

        * ‘fun’ – a function with no arguments

        * ‘t’ – a number >= 0

     Install a timer that calls 'fun' after 't' milliseconds.

          >>> running = True
          >>> def f():
          ...     if running:
          ...         fd(50)
          ...         lt(60)
          ...         screen.ontimer(f, 250)
          >>> f()   ### makes the turtle march around
          >>> running = False

 -- Funzione: turtle.mainloop ()
 -- Funzione: turtle.done ()

     Starts event loop - calling Tkinter’s mainloop function.  Must be
     the last statement in a turtle graphics program.  Must 'not' be
     used if a script is run from within IDLE in -n mode (No subprocess)
     - for interactive use of turtle graphics.

          >>> screen.mainloop()


File: python.info,  Node: Input methods,  Next: Settings and special methods,  Prev: Using screen events,  Up: Methods of TurtleScreen/Screen and corresponding functions

5.25.10.37 Input methods
........................

 -- Funzione: turtle.textinput (title, prompt)


     Parametri:

        * ‘title’ – string

        * ‘prompt’ – string

     Pop up a dialog window for input of a string.  Parameter title is
     the title of the dialog window, prompt is a text mostly describing
     what information to input.  Return the string input.  If the dialog
     is canceled, return ‘None’.

          >>> screen.textinput("NIM", "Name of first player:")

 -- Funzione: turtle.numinput (title, prompt, default=None, minval=None,
          maxval=None)


     Parametri:

        * ‘title’ – string

        * ‘prompt’ – string

        * ‘default’ – number (optional)

        * ‘minval’ – number (optional)

        * ‘maxval’ – number (optional)

     Pop up a dialog window for input of a number.  title is the title
     of the dialog window, prompt is a text mostly describing what
     numerical information to input.  default: default value, minval:
     minimum value for input, maxval: maximum value for input.  The
     number input must be in the range minval ..  maxval if these are
     given.  If not, a hint is issued and the dialog remains open for
     correction.  Return the number input.  If the dialog is canceled,
     return ‘None’.

          >>> screen.numinput("Poker", "Your stakes:", 1000, minval=10, maxval=10000)


File: python.info,  Node: Settings and special methods,  Next: Methods specific to Screen not inherited from TurtleScreen,  Prev: Input methods,  Up: Methods of TurtleScreen/Screen and corresponding functions

5.25.10.38 Settings and special methods
.......................................

 -- Funzione: turtle.mode (mode=None)


     Parametri: ‘mode’ – one of the strings «standard», «logo» or
     «world»

     Set turtle mode («standard», «logo» or «world») and perform reset.
     If mode is not given, current mode is returned.

     Mode «standard» is compatible with old *note turtle: 107.  Mode
     «logo» is compatible with most Logo turtle graphics.  Mode «world»
     uses user-defined «world coordinates».  'Attention': in this mode
     angles appear distorted if ‘x/y’ unit-ratio doesn’t equal 1.

     Mode             Initial turtle heading        positive angles
                                                    
     -----------------------------------------------------------------------
                                                    
     «standard»       to the right (east)           counterclockwise
                                                    
                                                    
     «logo»           upward (north)                clockwise
                                                    

          >>> mode("logo")   # resets turtle heading to north
          >>> mode()
          'logo'

 -- Funzione: turtle.colormode (cmode=None)


     Parametri: ‘cmode’ – one of the values 1.0 or 255

     Return the colormode or set it to 1.0 or 255.  Subsequently 'r',
     'g', 'b' values of color triples have to be in the range
     0..*cmode*.

          >>> screen.colormode(1)
          >>> turtle.pencolor(240, 160, 80)
          Traceback (most recent call last):
               ...
          TurtleGraphicsError: bad color sequence: (240, 160, 80)
          >>> screen.colormode()
          1.0
          >>> screen.colormode(255)
          >>> screen.colormode()
          255
          >>> turtle.pencolor(240,160,80)

 -- Funzione: turtle.getcanvas ()

     Return the Canvas of this TurtleScreen.  Useful for insiders who
     know what to do with a Tkinter Canvas.

          >>> cv = screen.getcanvas()
          >>> cv
          <turtle.ScrolledCanvas object ...>

 -- Funzione: turtle.getshapes ()

     Return a list of names of all currently available turtle shapes.

          >>> screen.getshapes()
          ['arrow', 'blank', 'circle', ..., 'turtle']

 -- Funzione: turtle.register_shape (name, shape=None)
 -- Funzione: turtle.addshape (name, shape=None)

     There are four different ways to call this function:

       1. 'name' is the name of an image file (PNG, GIF, PGM, and PPM)
          and 'shape' is ‘None’: Install the corresponding image shape.

               >>> screen.register_shape("turtle.gif")

               Nota: Image shapes 'do not' rotate when turning the
               turtle, so they do not display the heading of the turtle!

       2. 'name' is an arbitrary string and 'shape' is the name of an
          image file (PNG, GIF, PGM, and PPM): Install the corresponding
          image shape.

               >>> screen.register_shape("turtle", "turtle.gif")

               Nota: Image shapes 'do not' rotate when turning the
               turtle, so they do not display the heading of the turtle!

       3. 'name' is an arbitrary string and 'shape' is a tuple of pairs
          of coordinates: Install the corresponding polygon shape.

               >>> screen.register_shape("triangle", ((5,-3), (0,5), (-5,-3)))

       4. 'name' is an arbitrary string and 'shape' is a (compound)
          *note Shape: 4499. object: Install the corresponding compound
          shape.

     Add a turtle shape to TurtleScreen’s shapelist.  Only thusly
     registered shapes can be used by issuing the command
     ‘shape(shapename)’.

     Cambiato nella versione 3.14: Added support for PNG, PGM, and PPM
     image formats.  Both a shape name and an image file name can be
     specified.

 -- Funzione: turtle.turtles ()

     Return the list of turtles on the screen.

          >>> for turtle in screen.turtles():
          ...     turtle.color("red")

 -- Funzione: turtle.window_height ()

     Return the height of the turtle window.

          >>> screen.window_height()
          480

 -- Funzione: turtle.window_width ()

     Return the width of the turtle window.

          >>> screen.window_width()
          640


File: python.info,  Node: Methods specific to Screen not inherited from TurtleScreen,  Prev: Settings and special methods,  Up: Methods of TurtleScreen/Screen and corresponding functions

5.25.10.39 Methods specific to Screen, not inherited from TurtleScreen
......................................................................

 -- Funzione: turtle.bye ()

     Shut the turtlegraphics window.

 -- Funzione: turtle.exitonclick ()

     Bind ‘bye()’ method to mouse clicks on the Screen.

     If the value «using_IDLE» in the configuration dictionary is
     ‘False’ (default value), also enter mainloop.  Remark: If IDLE with
     the ‘-n’ switch (no subprocess) is used, this value should be set
     to ‘True’ in ‘turtle.cfg’.  In this case IDLE’s own mainloop is
     active also for the client script.

 -- Funzione: turtle.save (filename, overwrite=False)

     Save the current turtle drawing (and turtles) as a PostScript file.


     Parametri:

        * ‘filename’ – the path of the saved PostScript file

        * ‘overwrite’ – if ‘False’ and there already exists a file with
          the given filename, then the function will raise a
          ‘FileExistsError’.  If it is ‘True’, the file will be
          overwritten.

          >>> screen.save("my_drawing.ps")
          >>> screen.save("my_drawing.ps", overwrite=True)

     Added in version 3.14.

 -- Funzione: turtle.setup (width=_CFG['width'], height=_CFG['height'],
          startx=_CFG['leftright'], starty=_CFG['topbottom'])

     Set the size and position of the main window.  Default values of
     arguments are stored in the configuration dictionary and can be
     changed via a ‘turtle.cfg’ file.


     Parametri:

        * ‘width’ – if an integer, a size in pixels, if a float, a
          fraction of the screen; default is 50% of screen

        * ‘height’ – if an integer, the height in pixels, if a float, a
          fraction of the screen; default is 75% of screen

        * ‘startx’ – if positive, starting position in pixels from the
          left edge of the screen, if negative from the right edge, if
          ‘None’, center window horizontally

        * ‘starty’ – if positive, starting position in pixels from the
          top edge of the screen, if negative from the bottom edge, if
          ‘None’, center window vertically

          >>> screen.setup (width=200, height=200, startx=0, starty=0)
          >>>              # sets window to 200x200 pixels, in upper left of screen
          >>> screen.setup(width=.75, height=0.5, startx=None, starty=None)
          >>>              # sets window to 75% of screen by 50% of screen and centers

 -- Funzione: turtle.title (titlestring)


     Parametri: ‘titlestring’ – a string that is shown in the titlebar
     of the turtle graphics window

     Set title of turtle window to 'titlestring'.

          >>> screen.title("Welcome to the turtle zoo!")


File: python.info,  Node: Public classes,  Next: Explanation<2>,  Prev: Methods of TurtleScreen/Screen and corresponding functions,  Up: turtle — Turtle graphics

5.25.10.40 Public classes
.........................

 -- Classe: turtle.RawTurtle (canvas)
 -- Classe: turtle.RawPen (canvas)


     Parametri: ‘canvas’ – a ‘tkinter.Canvas’, a *note ScrolledCanvas:
     44a6. or a *note TurtleScreen: 4496.

     Create a turtle.  The turtle has all methods described above as
     «methods of Turtle/RawTurtle».

 -- Classe: turtle.Turtle

     Subclass of RawTurtle, has the same interface but draws on a
     default *note Screen: 441b. object created automatically when
     needed for the first time.

 -- Classe: turtle.TurtleScreen (cv)


     Parametri: ‘cv’ – a ‘tkinter.Canvas’

     Provides screen oriented methods like *note bgcolor(): 4469. etc.
     that are described above.

 -- Classe: turtle.Screen

     Subclass of TurtleScreen, with *note four methods added: 44a2.

 -- Classe: turtle.ScrolledCanvas (master)


     Parametri: ‘master’ – some Tkinter widget to contain the
     ScrolledCanvas, i.e.  a Tkinter-canvas with scrollbars added

     Used by class Screen, which thus automatically provides a
     ScrolledCanvas as playground for the turtles.

 -- Classe: turtle.Shape (type_, data)


     Parametri: ‘type_’ – one of the strings «polygon», «image»,
     «compound»

     Data structure modeling shapes.  The pair ‘(type_, data)’ must
     follow this specification:

     'type_'         'data'
                     
     -------------------------------------------------------------------------------
                     
     «polygon»       a polygon-tuple, i.e.  a tuple of pairs of coordinates
                     
                     
     «image»         an image (in this form only used internally!)
                     
                     
     «compound»      ‘None’ (a compound shape has to be constructed using the
                     *note addcomponent(): 449a. method)
                     

      -- Metodo: addcomponent (poly, fill, outline=None)


          Parametri:

             * ‘poly’ – a polygon, i.e.  a tuple of pairs of numbers

             * ‘fill’ – a color the 'poly' will be filled with

             * ‘outline’ – a color for the poly’s outline (if given)

          Example:

               >>> poly = ((0,0),(10,-5),(0,10),(-10,-5))
               >>> s = Shape("compound")
               >>> s.addcomponent(poly, "red", "blue")
               >>> # ... add more components and then use register_shape()

          See *note Compound shapes: 4498.

 -- Classe: turtle.Vec2D (x, y)

     A two-dimensional vector class, used as a helper class for
     implementing turtle graphics.  May be useful for turtle graphics
     programs too.  Derived from tuple, so a vector is a tuple!

     Provides (for 'a', 'b' vectors, 'k' number):

        * ‘a + b’ vector addition

        * ‘a - b’ vector subtraction

        * ‘a * b’ inner product

        * ‘k * a’ and ‘a * k’ multiplication with scalar

        * ‘abs(a)’ absolute value of a

        * ‘a.rotate(angle)’ rotation


File: python.info,  Node: Explanation<2>,  Next: Help and configuration,  Prev: Public classes,  Up: turtle — Turtle graphics

5.25.10.41 Explanation
......................

A turtle object draws on a screen object, and there a number of key
classes in the turtle object-oriented interface that can be used to
create them and relate them to each other.

A *note Turtle: 44a7. instance will automatically create a *note Screen:
441b. instance if one is not already present.

‘Turtle’ is a subclass of *note RawTurtle: 44a4, which 'doesn’t'
automatically create a drawing surface - a 'canvas' will need to be
provided or created for it.  The 'canvas' can be a ‘tkinter.Canvas’,
*note ScrolledCanvas: 44a6. or *note TurtleScreen: 4496.

*note TurtleScreen: 4496. is the basic drawing surface for a turtle.
*note Screen: 441b. is a subclass of ‘TurtleScreen’, and includes *note
some additional methods: 44a2. for managing its appearance (including
size and title) and behaviour.  ‘TurtleScreen’’s constructor needs a
‘tkinter.Canvas’ or a *note ScrolledCanvas: 44a6. as an argument.

The functional interface for turtle graphics uses the various methods of
‘Turtle’ and ‘TurtleScreen’/‘Screen’.  Behind the scenes, a screen
object is automatically created whenever a function derived from a
‘Screen’ method is called.  Similarly, a turtle object is automatically
created whenever any of the functions derived from a Turtle method is
called.

To use multiple turtles on a screen, the object-oriented interface must
be used.


File: python.info,  Node: Help and configuration,  Next: turtledemo — Demo scripts,  Prev: Explanation<2>,  Up: turtle — Turtle graphics

5.25.10.42 Help and configuration
.................................

* Menu:

* How to use help::
* Translation of docstrings into different languages::
* How to configure Screen and Turtles::


File: python.info,  Node: How to use help,  Next: Translation of docstrings into different languages,  Up: Help and configuration

5.25.10.43 How to use help
..........................

The public methods of the Screen and Turtle classes are documented
extensively via docstrings.  So these can be used as online-help via the
Python help facilities:

   - When using IDLE, tooltips show the signatures and first lines of
     the docstrings of typed in function-/method calls.

   - Calling *note help(): ad6. on methods or functions displays the
     docstrings:

          >>> help(Screen.bgcolor)
          Help on method bgcolor in module turtle:

          bgcolor(self, *args) unbound turtle.Screen method
              Set or return backgroundcolor of the TurtleScreen.

              Arguments (if given): a color string or three numbers
              in the range 0..colormode or a 3-tuple of such numbers.


              >>> screen.bgcolor("orange")
              >>> screen.bgcolor()
              "orange"
              >>> screen.bgcolor(0.5,0,0.5)
              >>> screen.bgcolor()
              "#800080"

          >>> help(Turtle.penup)
          Help on method penup in module turtle:

          penup(self) unbound turtle.Turtle method
              Pull the pen up -- no drawing when moving.

              Aliases: penup | pu | up

              No argument

              >>> turtle.penup()

   - The docstrings of the functions which are derived from methods have
     a modified form:

          >>> help(bgcolor)
          Help on function bgcolor in module turtle:

          bgcolor(*args)
              Set or return backgroundcolor of the TurtleScreen.

              Arguments (if given): a color string or three numbers
              in the range 0..colormode or a 3-tuple of such numbers.

              Example::

                >>> bgcolor("orange")
                >>> bgcolor()
                "orange"
                >>> bgcolor(0.5,0,0.5)
                >>> bgcolor()
                "#800080"

          >>> help(penup)
          Help on function penup in module turtle:

          penup()
              Pull the pen up -- no drawing when moving.

              Aliases: penup | pu | up

              No argument

              Example:
              >>> penup()

These modified docstrings are created automatically together with the
function definitions that are derived from the methods at import time.


File: python.info,  Node: Translation of docstrings into different languages,  Next: How to configure Screen and Turtles,  Prev: How to use help,  Up: Help and configuration

5.25.10.44 Translation of docstrings into different languages
.............................................................

There is a utility to create a dictionary the keys of which are the
method names and the values of which are the docstrings of the public
methods of the classes Screen and Turtle.

 -- Funzione: turtle.write_docstringdict
          (filename='turtle_docstringdict')


     Parametri: ‘filename’ – a string, used as filename

     Create and write docstring-dictionary to a Python script with the
     given filename.  This function has to be called explicitly (it is
     not used by the turtle graphics classes).  The docstring dictionary
     will be written to the Python script ‘`filename'.py’.  It is
     intended to serve as a template for translation of the docstrings
     into different languages.

If you (or your students) want to use *note turtle: 107. with online
help in your native language, you have to translate the docstrings and
save the resulting file as e.g.  ‘turtle_docstringdict_german.py’.

If you have an appropriate entry in your ‘turtle.cfg’ file this
dictionary will be read in at import time and will replace the original
English docstrings.

At the time of this writing there are docstring dictionaries in German
and in Italian.  (Requests please to <glingl@aon.at>.)


File: python.info,  Node: How to configure Screen and Turtles,  Prev: Translation of docstrings into different languages,  Up: Help and configuration

5.25.10.45 How to configure Screen and Turtles
..............................................

The built-in default configuration mimics the appearance and behaviour
of the old turtle module in order to retain best possible compatibility
with it.

If you want to use a different configuration which better reflects the
features of this module or which better fits to your needs, e.g.  for
use in a classroom, you can prepare a configuration file ‘turtle.cfg’
which will be read at import time and modify the configuration according
to its settings.

The built in configuration would correspond to the following
‘turtle.cfg’:

     width = 0.5
     height = 0.75
     leftright = None
     topbottom = None
     canvwidth = 400
     canvheight = 300
     mode = standard
     colormode = 1.0
     delay = 10
     undobuffersize = 1000
     shape = classic
     pencolor = black
     fillcolor = black
     resizemode = noresize
     visible = True
     language = english
     exampleturtle = turtle
     examplescreen = screen
     title = Python Turtle Graphics
     using_IDLE = False

Short explanation of selected entries:

   - The first four lines correspond to the arguments of the *note
     Screen.setup: 4485. method.

   - Line 5 and 6 correspond to the arguments of the method *note
     Screen.screensize: 446d.

   - 'shape' can be any of the built-in shapes, e.g: arrow, turtle, etc.
     For more info try ‘help(shape)’.

   - If you want to use no fill color (i.e.  make the turtle
     transparent), you have to write ‘fillcolor = ""’ (but all nonempty
     strings must not have quotes in the cfg file).

   - If you want to reflect the turtle its state, you have to use
     ‘resizemode = auto’.

   - If you set e.g.  ‘language = italian’ the docstringdict
     ‘turtle_docstringdict_italian.py’ will be loaded at import time (if
     present on the import path, e.g.  in the same directory as *note
     turtle: 107.).

   - The entries 'exampleturtle' and 'examplescreen' define the names of
     these objects as they occur in the docstrings.  The transformation
     of method-docstrings to function-docstrings will delete these names
     from the docstrings.

   - 'using_IDLE': Set this to ‘True’ if you regularly work with IDLE
     and its ‘-n’ switch («no subprocess»).  This will prevent *note
     exitonclick(): 4484. to enter the mainloop.

There can be a ‘turtle.cfg’ file in the directory where *note turtle:
107. is stored and an additional one in the current working directory.
The latter will override the settings of the first one.

The ‘Lib/turtledemo’ directory contains a ‘turtle.cfg’ file.  You can
study it as an example and see its effects when running the demos
(preferably not from within the demo-viewer).


File: python.info,  Node: turtledemo — Demo scripts,  Next: Changes since Python 2 6,  Prev: Help and configuration,  Up: turtle — Turtle graphics

5.25.10.46 ‘turtledemo’ — Demo scripts
......................................

The *note turtledemo: 108. package includes a set of demo scripts.
These scripts can be run and viewed using the supplied demo viewer as
follows:

     python -m turtledemo

Alternatively, you can run the demo scripts individually.  For example,

     python -m turtledemo.bytedesign

The *note turtledemo: 108. package directory contains:

   - A demo viewer ‘__main__.py’ which can be used to view the
     sourcecode of the scripts and run them at the same time.

   - Multiple scripts demonstrating different features of the *note
     turtle: 107. module.  Examples can be accessed via the Examples
     menu.  They can also be run standalone.

   - A ‘turtle.cfg’ file which serves as an example of how to write and
     use such files.

The demo scripts are:

Name                         Description                        Features
                                                                
-----------------------------------------------------------------------------------------------------------
                                                                
‘bytedesign’                 complex classical turtle           *note tracer(): 4470,
                             graphics pattern                   *note delay(): 446f,
                                                                *note update(): 4471.
                                                                
                                                                
‘chaos’                      graphs Verhulst dynamics, shows    world coordinates
                             that computer’s computations can   
                             generate results sometimes
                             against the common sense
                             expectations
                             
                                                                
‘clock’                      analog clock showing time of       turtles as clock’s hands,
                             your computer                      *note ontimer(): 4477.
                                                                
                                                                
‘colormixer’                 experiment with r, g, b            *note ondrag(): 445e.
                                                                
                                                                
‘forest’                     3 breadth-first trees              randomization
                                                                
                                                                
‘fractalcurves’              Hilbert & Koch curves              recursion
                                                                
                                                                
‘lindenmayer’                ethnomathematics (indian kolams)   L-System
                                                                
                                                                
‘minimal_hanoi’              Towers of Hanoi                    Rectangular Turtles as Hanoi discs
                                                                (*note shape(): 4454,
                                                                *note shapesize(): 4456.)
                                                                
                                                                
‘nim’                        play the classical nim game with   turtles as nimsticks, event driven
                             three heaps of sticks against      (mouse, keyboard)
                             the computer.                      
                             
                                                                
‘paint’                      super minimalistic drawing         *note onclick(): 445c.
                             program                            
                             
                                                                
‘peace’                      elementary                         turtle: appearance and animation
                                                                
                                                                
‘penrose’                    aperiodic tiling with kites and    *note stamp(): 4430.
                             darts                              
                             
                                                                
‘planet_and_moon’            simulation of gravitational        compound shapes, *note Vec2D: 4489.
                             system                             
                             
                                                                
‘rosette’                    a pattern from the wikipedia       *note clone(): 4462, *note undo(): 4433.
                             article on turtle graphics         
                             
                                                                
‘round_dance’                dancing turtles rotating           compound shapes, *note clone(): 4462.
                             pairwise in opposite direction     *note shapesize(): 4456,
                                                                *note tilt(): 4459,
                                                                *note get_shapepoly(): 445b,
                                                                *note update(): 4471.
                                                                
                                                                
‘sorting_animate’            visual demonstration of            simple alignment, randomization
                             different sorting methods          
                             
                                                                
‘tree’                       a (graphical) breadth first tree   *note clone(): 4462.
                             (using generators)                 
                             
                                                                
‘two_canvases’               simple design                      turtles on two canvases
                                                                
                                                                
‘yinyang’                    another elementary example         *note circle(): 442e.
                                                                

Have fun!


File: python.info,  Node: Changes since Python 2 6,  Next: Changes since Python 3 0,  Prev: turtledemo — Demo scripts,  Up: turtle — Turtle graphics

5.25.10.47 Changes since Python 2.6
...................................

   - The methods *note Turtle.tracer: 4470, *note Turtle.window_width:
     4482. and *note Turtle.window_height: 4481. have been eliminated.
     Methods with these names and functionality are now available only
     as methods of *note Screen: 441b.  The functions derived from these
     remain available.  (In fact already in Python 2.6 these methods
     were merely duplications of the corresponding *note TurtleScreen:
     4496./*note Screen: 441b. methods.)

   - The method ‘Turtle.fill()’ has been eliminated.  The behaviour of
     *note begin_fill(): 4415. and *note end_fill(): 4416. have changed
     slightly: now every filling process must be completed with an
     ‘end_fill()’ call.

   - A method *note Turtle.filling: 444b. has been added.  It returns a
     boolean value: ‘True’ if a filling process is under way, ‘False’
     otherwise.  This behaviour corresponds to a ‘fill()’ call without
     arguments in Python 2.6.


File: python.info,  Node: Changes since Python 3 0,  Prev: Changes since Python 2 6,  Up: turtle — Turtle graphics

5.25.10.48 Changes since Python 3.0
...................................

   - The *note Turtle: 44a7. methods *note shearfactor(): 4458, *note
     shapetransform(): 445a. and *note get_shapepoly(): 445b. have been
     added.  Thus the full range of regular linear transforms is now
     available for transforming turtle shapes.  *note tiltangle(): 930.
     has been enhanced in functionality: it now can be used to get or
     set the tilt angle.

   - The *note Screen: 441b. method *note onkeypress(): 4475. has been
     added as a complement to *note onkey(): 4473.  As the latter binds
     actions to the key release event, an alias: *note onkeyrelease():
     4474. was also added for it.

   - The method *note Screen.mainloop: 4478. has been added, so there is
     no longer a need to use the standalone *note mainloop(): 4478.
     function when working with *note Screen: 441b. and *note Turtle:
     44a7. objects.

   - Two input methods have been added: *note Screen.textinput: 1c62.
     and *note Screen.numinput: 1c63.  These pop up input dialogs and
     return strings and numbers respectively.


File: python.info,  Node: Development Tools,  Next: Debugging and Profiling,  Prev: Graphical user interfaces with Tk,  Up: The Python Standard Library

5.26 Development Tools
======================

The modules described in this chapter help you write software.  For
example, the *note pydoc: ba. module takes a module and generates
documentation based on the module’s contents.  The *note doctest: 3e.
and *note unittest: 10c. modules contains frameworks for writing unit
tests that automatically exercise code and verify that the expected
output is produced.

The list of modules described in this chapter is:

* Menu:

* typing — Support for type hints::
* pydoc — Documentation generator and online help system::
* Python Development Mode::
* doctest — Test interactive Python examples::
* unittest — Unit testing framework::
* unittest.mock — mock object library: unittest mock — mock object library.
* unittest.mock — getting started: unittest mock — getting started.
* test — Regression tests package for Python::
* test.support — Utilities for the Python test suite: test support — Utilities for the Python test suite.
* test.support.socket_helper — Utilities for socket tests: test support socket_helper — Utilities for socket tests.
* test.support.script_helper — Utilities for the Python execution tests: test support script_helper — Utilities for the Python execution tests.
* test.support.bytecode_helper — Support tools for testing correct bytecode generation: test support bytecode_helper — Support tools for testing correct bytecode generation.
* test.support.threading_helper — Utilities for threading tests: test support threading_helper — Utilities for threading tests.
* test.support.os_helper — Utilities for os tests: test support os_helper — Utilities for os tests.
* test.support.import_helper — Utilities for import tests: test support import_helper — Utilities for import tests.
* test.support.warnings_helper — Utilities for warnings tests: test support warnings_helper — Utilities for warnings tests.


File: python.info,  Node: typing — Support for type hints,  Next: pydoc — Documentation generator and online help system,  Up: Development Tools

5.26.1 ‘typing’ — Support for type hints
----------------------------------------

Added in version 3.5.

'Source code:' Lib/typing.py(1)

     Nota: The Python runtime does not enforce function and variable
     type annotations.  They can be used by third party tools such as
     *note type checkers: 574, IDEs, linters, etc.

__________________________________________________________________

This module provides runtime support for type hints.

Consider the function below:

     def surface_area_of_cube(edge_length: float) -> str:
         return f"The surface area of the cube is {6 * edge_length ** 2}."

The function ‘surface_area_of_cube’ takes an argument expected to be an
instance of *note float: 196, as indicated by the *note type hint: 23b1.
‘edge_length: float’.  The function is expected to return an instance of
*note str: 169, as indicated by the ‘-> str’ hint.

While type hints can be simple classes like *note float: 196. or *note
str: 169, they can also be more complex.  The *note typing: 10a. module
provides a vocabulary of more advanced type hints.

New features are frequently added to the ‘typing’ module.  The
typing_extensions(2) package provides backports of these new features to
older versions of Python.

Vedi anche
..........

Typing cheat sheet(3)

     A quick overview of type hints (hosted at the mypy docs)

Type System Reference section of the mypy docs(4)

     The Python typing system is standardised via PEPs, so this
     reference should broadly apply to most Python type checkers.  (Some
     parts may still be specific to mypy.)

Static Typing with Python(5)

     Type-checker-agnostic documentation written by the community
     detailing type system features, useful typing related tools and
     typing best practices.

* Menu:

* Specification for the Python Type System::
* Type aliases::
* NewType::
* Annotating callable objects::
* Generics::
* Annotating tuples::
* The type of class objects::
* Annotating generators and coroutines::
* User-defined generic types::
* The Any type::
* Nominal vs structural subtyping::
* Module contents: Module contents<3>.
* Deprecation Timeline of Major Features::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/typing.py

   (2) https://pypi.org/project/typing_extensions/

   (3) https://mypy.readthedocs.io/en/stable/cheat_sheet_py3.html

   (4) https://mypy.readthedocs.io/en/stable/index.html

   (5) https://typing.python.org/en/latest/


File: python.info,  Node: Specification for the Python Type System,  Next: Type aliases,  Up: typing — Support for type hints

5.26.1.1 Specification for the Python Type System
.................................................

The canonical, up-to-date specification of the Python type system can be
found at Specification for the Python type system(1).

   ---------- Footnotes ----------

   (1) https://typing.python.org/en/latest/spec/index.html


File: python.info,  Node: Type aliases,  Next: NewType,  Prev: Specification for the Python Type System,  Up: typing — Support for type hints

5.26.1.2 Type aliases
.....................

A type alias is defined using the *note type: 66d. statement, which
creates an instance of *note TypeAliasType: 2ae.  In this example,
‘Vector’ and ‘list[float]’ will be treated equivalently by static type
checkers:

     type Vector = list[float]

     def scale(scalar: float, vector: Vector) -> Vector:
         return [scalar * num for num in vector]

     # passes type checking; a list of floats qualifies as a Vector.
     new_vector = scale(2.0, [1.0, -4.2, 5.4])

Type aliases are useful for simplifying complex type signatures.  For
example:

     from collections.abc import Sequence

     type ConnectionOptions = dict[str, str]
     type Address = tuple[str, int]
     type Server = tuple[Address, ConnectionOptions]

     def broadcast_message(message: str, servers: Sequence[Server]) -> None:
         ...

     # The static type checker will treat the previous type signature as
     # being exactly equivalent to this one.
     def broadcast_message(
         message: str,
         servers: Sequence[tuple[tuple[str, int], dict[str, str]]]
     ) -> None:
         ...

The *note type: 66d. statement is new in Python 3.12.  For backwards
compatibility, type aliases can also be created through simple
assignment:

     Vector = list[float]

Or marked with *note TypeAlias: 9ce. to make it explicit that this is a
type alias, not a normal variable assignment:

     from typing import TypeAlias

     Vector: TypeAlias = list[float]


File: python.info,  Node: NewType,  Next: Annotating callable objects,  Prev: Type aliases,  Up: typing — Support for type hints

5.26.1.3 NewType
................

Use the *note NewType: ef3. helper to create distinct types:

     from typing import NewType

     UserId = NewType('UserId', int)
     some_id = UserId(524313)

The static type checker will treat the new type as if it were a subclass
of the original type.  This is useful in helping catch logical errors:

     def get_user_name(user_id: UserId) -> str:
         ...

     # passes type checking
     user_a = get_user_name(UserId(42351))

     # fails type checking; an int is not a UserId
     user_b = get_user_name(-1)

You may still perform all ‘int’ operations on a variable of type
‘UserId’, but the result will always be of type ‘int’.  This lets you
pass in a ‘UserId’ wherever an ‘int’ might be expected, but will prevent
you from accidentally creating a ‘UserId’ in an invalid way:

     # 'output' is of type 'int', not 'UserId'
     output = UserId(23413) + UserId(54341)

Note that these checks are enforced only by the static type checker.  At
runtime, the statement ‘Derived = NewType('Derived', Base)’ will make
‘Derived’ a callable that immediately returns whatever parameter you
pass it.  That means the expression ‘Derived(some_value)’ does not
create a new class or introduce much overhead beyond that of a regular
function call.

More precisely, the expression ‘some_value is Derived(some_value)’ is
always true at runtime.

It is invalid to create a subtype of ‘Derived’:

     from typing import NewType

     UserId = NewType('UserId', int)

     # Fails at runtime and does not pass type checking
     class AdminUserId(UserId): pass

However, it is possible to create a *note NewType: ef3. based on a
“derived” ‘NewType’:

     from typing import NewType

     UserId = NewType('UserId', int)

     ProUserId = NewType('ProUserId', UserId)

and typechecking for ‘ProUserId’ will work as expected.

See PEP 484(1) for more details.

     Nota: Recall that the use of a type alias declares two types to be
     'equivalent' to one another.  Doing ‘type Alias = Original’ will
     make the static type checker treat ‘Alias’ as being 'exactly
     equivalent' to ‘Original’ in all cases.  This is useful when you
     want to simplify complex type signatures.

     In contrast, ‘NewType’ declares one type to be a 'subtype' of
     another.  Doing ‘Derived = NewType('Derived', Original)’ will make
     the static type checker treat ‘Derived’ as a 'subclass' of
     ‘Original’, which means a value of type ‘Original’ cannot be used
     in places where a value of type ‘Derived’ is expected.  This is
     useful when you want to prevent logic errors with minimal runtime
     cost.

Added in version 3.5.2.

Cambiato nella versione 3.10: ‘NewType’ is now a class rather than a
function.  As a result, there is some additional runtime cost when
calling ‘NewType’ over a regular function.

Cambiato nella versione 3.11: The performance of calling ‘NewType’ has
been restored to its level in Python 3.9.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/


File: python.info,  Node: Annotating callable objects,  Next: Generics,  Prev: NewType,  Up: typing — Support for type hints

5.26.1.4 Annotating callable objects
....................................

Functions – or other *note callable: 2d61. objects – can be annotated
using *note collections.abc.Callable: 9ed. or deprecated *note
typing.Callable: 9ca.  ‘Callable[[int], str]’ signifies a function that
takes a single parameter of type *note int: 19b. and returns a *note
str: 169.

For example:

     from collections.abc import Callable, Awaitable

     def feeder(get_next_item: Callable[[], str]) -> None:
         ...  # Body

     def async_query(on_success: Callable[[int], None],
                     on_error: Callable[[int, Exception], None]) -> None:
         ...  # Body

     async def on_update(value: str) -> None:
         ...  # Body

     callback: Callable[[str], Awaitable[None]] = on_update

The subscription syntax must always be used with exactly two values: the
argument list and the return type.  The argument list must be a list of
types, a *note ParamSpec: 488, *note Concatenate: 9c9, or an ellipsis
(‘...’).  The return type must be a single type.

If a literal ellipsis ‘...’ is given as the argument list, it indicates
that a callable with any arbitrary parameter list would be acceptable:

     def concat(x: str, y: str) -> str:
         return x + y

     x: Callable[..., str]
     x = str     # OK
     x = concat  # Also OK

‘Callable’ cannot express complex signatures such as functions that take
a variadic number of arguments, *note overloaded functions: 44bd, or
functions that have keyword-only parameters.  However, these signatures
can be expressed by defining a *note Protocol: 56b. class with a *note
__call__(): 77b. method:

     from collections.abc import Iterable
     from typing import Protocol

     class Combiner(Protocol):
         def __call__(self, *vals: bytes, maxlen: int | None = None) -> list[bytes]: ...

     def batch_proc(data: Iterable[bytes], cb_results: Combiner) -> bytes:
         for item in data:
             ...

     def good_cb(*vals: bytes, maxlen: int | None = None) -> list[bytes]:
         ...
     def bad_cb(*vals: bytes, maxitems: int | None) -> list[bytes]:
         ...

     batch_proc([], good_cb)  # OK
     batch_proc([], bad_cb)   # Error! Argument 2 has incompatible type because of
                              # different name and kind in the callback

Callables which take other callables as arguments may indicate that
their parameter types are dependent on each other using *note ParamSpec:
488.  Additionally, if that callable adds or removes arguments from
other callables, the *note Concatenate: 9c9. operator may be used.  They
take the form ‘Callable[ParamSpecVariable, ReturnType]’ and
‘Callable[Concatenate[Arg1Type, Arg2Type, ..., ParamSpecVariable],
ReturnType]’ respectively.

Cambiato nella versione 3.10: ‘Callable’ now supports *note ParamSpec:
488. and *note Concatenate: 9c9.  See PEP 612(1) for more details.

Vedi anche
..........

The documentation for *note ParamSpec: 488. and *note Concatenate: 9c9.
provides examples of usage in ‘Callable’.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0612/


File: python.info,  Node: Generics,  Next: Annotating tuples,  Prev: Annotating callable objects,  Up: typing — Support for type hints

5.26.1.5 Generics
.................

Since type information about objects kept in containers cannot be
statically inferred in a generic way, many container classes in the
standard library support subscription to denote the expected types of
container elements.

     from collections.abc import Mapping, Sequence

     class Employee: ...

     # Sequence[Employee] indicates that all elements in the sequence
     # must be instances of "Employee".
     # Mapping[str, str] indicates that all keys and all values in the mapping
     # must be strings.
     def notify_by_email(employees: Sequence[Employee],
                         overrides: Mapping[str, str]) -> None: ...

Generic functions and classes can be parameterized by using *note type
parameter syntax: 5ad.:

     from collections.abc import Sequence

     def first[T](l: Sequence[T]) -> T:  # Function is generic over the TypeVar "T"
         return l[0]

Or by using the *note TypeVar: 487. factory directly:

     from collections.abc import Sequence
     from typing import TypeVar

     U = TypeVar('U')                  # Declare type variable "U"

     def second(l: Sequence[U]) -> U:  # Function is generic over the TypeVar "U"
         return l[1]

Cambiato nella versione 3.12: Syntactic support for generics is new in
Python 3.12.


File: python.info,  Node: Annotating tuples,  Next: The type of class objects,  Prev: Generics,  Up: typing — Support for type hints

5.26.1.6 Annotating tuples
..........................

For most containers in Python, the typing system assumes that all
elements in the container will be of the same type.  For example:

     from collections.abc import Mapping

     # Type checker will infer that all elements in ``x`` are meant to be ints
     x: list[int] = []

     # Type checker error: ``list`` only accepts a single type argument:
     y: list[int, str] = [1, 'foo']

     # Type checker will infer that all keys in ``z`` are meant to be strings,
     # and that all values in ``z`` are meant to be either strings or ints
     z: Mapping[str, str | int] = {}

*note list: 24d. only accepts one type argument, so a type checker would
emit an error on the ‘y’ assignment above.  Similarly, *note Mapping:
ac9. only accepts two type arguments: the first indicates the type of
the keys, and the second indicates the type of the values.

Unlike most other Python containers, however, it is common in idiomatic
Python code for tuples to have elements which are not all of the same
type.  For this reason, tuples are special-cased in Python’s typing
system.  *note tuple: 614. accepts 'any number' of type arguments:

     # OK: ``x`` is assigned to a tuple of length 1 where the sole element is an int
     x: tuple[int] = (5,)

     # OK: ``y`` is assigned to a tuple of length 2;
     # element 1 is an int, element 2 is a str
     y: tuple[int, str] = (5, "foo")

     # Error: the type annotation indicates a tuple of length 1,
     # but ``z`` has been assigned to a tuple of length 3
     z: tuple[int] = (1, 2, 3)

To denote a tuple which could be of 'any' length, and in which all
elements are of the same type ‘T’, use the literal ellipsis ‘...’:
‘tuple[T, ...]’.  To denote an empty tuple, use ‘tuple[()]’.  Using
plain ‘tuple’ as an annotation is equivalent to using ‘tuple[Any, ...]’:

     x: tuple[int, ...] = (1, 2)
     # These reassignments are OK: ``tuple[int, ...]`` indicates x can be of any length
     x = (1, 2, 3)
     x = ()
     # This reassignment is an error: all elements in ``x`` must be ints
     x = ("foo", "bar")

     # ``y`` can only ever be assigned to an empty tuple
     y: tuple[()] = ()

     z: tuple = ("foo", "bar")
     # These reassignments are OK: plain ``tuple`` is equivalent to ``tuple[Any, ...]``
     z = (1, 2, 3)
     z = ()


File: python.info,  Node: The type of class objects,  Next: Annotating generators and coroutines,  Prev: Annotating tuples,  Up: typing — Support for type hints

5.26.1.7 The type of class objects
..................................

A variable annotated with ‘C’ may accept a value of type ‘C’.  In
contrast, a variable annotated with ‘type[C]’ (or deprecated *note
typing.Type[C]: 44c2.) may accept values that are classes themselves –
specifically, it will accept the 'class object' of ‘C’.  For example:

     a = 3         # Has type ``int``
     b = int       # Has type ``type[int]``
     c = type(a)   # Also has type ``type[int]``

Note that ‘type[C]’ is covariant:

     class User: ...
     class ProUser(User): ...
     class TeamUser(User): ...

     def make_new_user(user_class: type[User]) -> User:
         # ...
         return user_class()

     make_new_user(User)      # OK
     make_new_user(ProUser)   # Also OK: ``type[ProUser]`` is a subtype of ``type[User]``
     make_new_user(TeamUser)  # Still fine
     make_new_user(User())    # Error: expected ``type[User]`` but got ``User``
     make_new_user(int)       # Error: ``type[int]`` is not a subtype of ``type[User]``

The only legal parameters for *note type: f46. are classes, *note Any:
8bc, *note type variables: 23af, and unions of any of these types.  For
example:

     def new_non_team_user(user_class: type[BasicUser | ProUser]): ...

     new_non_team_user(BasicUser)  # OK
     new_non_team_user(ProUser)    # OK
     new_non_team_user(TeamUser)   # Error: ``type[TeamUser]`` is not a subtype
                                   # of ``type[BasicUser | ProUser]``
     new_non_team_user(User)       # Also an error

‘type[Any]’ is equivalent to *note type: f46, which is the root of
Python’s *note metaclass hierarchy: 23a4.


File: python.info,  Node: Annotating generators and coroutines,  Next: User-defined generic types,  Prev: The type of class objects,  Up: typing — Support for type hints

5.26.1.8 Annotating generators and coroutines
.............................................

A generator can be annotated using the generic type *note
Generator[YieldType, SendType, ReturnType]: fdd.  For example:

     def echo_round() -> Generator[int, float, str]:
         sent = yield 0
         while sent >= 0:
             sent = yield round(sent)
         return 'Done'

Note that unlike many other generic classes in the standard library, the
‘SendType’ of *note Generator: fdd. behaves contravariantly, not
covariantly or invariantly.

The ‘SendType’ and ‘ReturnType’ parameters default to ‘None’:

     def infinite_stream(start: int) -> Generator[int]:
         while True:
             yield start
             start += 1

It is also possible to set these types explicitly:

     def infinite_stream(start: int) -> Generator[int, None, None]:
         while True:
             yield start
             start += 1

Simple generators that only ever yield values can also be annotated as
having a return type of either *note Iterable[YieldType]: 2691. or *note
Iterator[YieldType]: 2692.:

     def infinite_stream(start: int) -> Iterator[int]:
         while True:
             yield start
             start += 1

Async generators are handled in a similar fashion, but don’t expect a
‘ReturnType’ type argument (*note AsyncGenerator[YieldType, SendType]:
e89.).  The ‘SendType’ argument defaults to ‘None’, so the following
definitions are equivalent:

     async def infinite_stream(start: int) -> AsyncGenerator[int]:
         while True:
             yield start
             start = await increment(start)

     async def infinite_stream(start: int) -> AsyncGenerator[int, None]:
         while True:
             yield start
             start = await increment(start)

As in the synchronous case, *note AsyncIterable[YieldType]: fe1. and
*note AsyncIterator[YieldType]: fe0. are available as well:

     async def infinite_stream(start: int) -> AsyncIterator[int]:
         while True:
             yield start
             start = await increment(start)

Coroutines can be annotated using *note Coroutine[YieldType, SendType,
ReturnType]: fdf.  Generic arguments correspond to those of *note
Generator: fdd, for example:

     from collections.abc import Coroutine
     c: Coroutine[list[str], str, int]  # Some coroutine defined elsewhere
     x = c.send('hi')                   # Inferred type of 'x' is list[str]
     async def bar() -> None:
         y = await c                    # Inferred type of 'y' is int


File: python.info,  Node: User-defined generic types,  Next: The Any type,  Prev: Annotating generators and coroutines,  Up: typing — Support for type hints

5.26.1.9 User-defined generic types
...................................

A user-defined class can be defined as a generic class.

     from logging import Logger

     class LoggedVar[T]:
         def __init__(self, value: T, name: str, logger: Logger) -> None:
             self.name = name
             self.logger = logger
             self.value = value

         def set(self, new: T) -> None:
             self.log('Set ' + repr(self.value))
             self.value = new

         def get(self) -> T:
             self.log('Get ' + repr(self.value))
             return self.value

         def log(self, message: str) -> None:
             self.logger.info('%s: %s', self.name, message)

This syntax indicates that the class ‘LoggedVar’ is parameterised around
a single *note type variable: 44c5. ‘T’ .  This also makes ‘T’ valid as
a type within the class body.

Generic classes implicitly inherit from *note Generic: 179e.  For
compatibility with Python 3.11 and lower, it is also possible to inherit
explicitly from *note Generic: 179e. to indicate a generic class:

     from typing import TypeVar, Generic

     T = TypeVar('T')

     class LoggedVar(Generic[T]):
         ...

Generic classes have *note __class_getitem__(): 944. methods, meaning
they can be parameterised at runtime (e.g.  ‘LoggedVar[int]’ below):

     from collections.abc import Iterable

     def zero_all_vars(vars: Iterable[LoggedVar[int]]) -> None:
         for var in vars:
             var.set(0)

A generic type can have any number of type variables.  All varieties of
*note TypeVar: 487. are permissible as parameters for a generic type:

     from typing import TypeVar, Generic, Sequence

     class WeirdTrio[T, B: Sequence[bytes], S: (int, str)]:
         ...

     OldT = TypeVar('OldT', contravariant=True)
     OldB = TypeVar('OldB', bound=Sequence[bytes], covariant=True)
     OldS = TypeVar('OldS', int, str)

     class OldWeirdTrio(Generic[OldT, OldB, OldS]):
         ...

Each type variable argument to *note Generic: 179e. must be distinct.
This is thus invalid:

     from typing import TypeVar, Generic
     ...

     class Pair[M, M]:  # SyntaxError
         ...

     T = TypeVar('T')

     class Pair(Generic[T, T]):   # INVALID
         ...

Generic classes can also inherit from other classes:

     from collections.abc import Sized

     class LinkedList[T](Sized):
         ...

When inheriting from generic classes, some type parameters could be
fixed:

     from collections.abc import Mapping

     class MyDict[T](Mapping[str, T]):
         ...

In this case ‘MyDict’ has a single parameter, ‘T’.

Using a generic class without specifying type parameters assumes *note
Any: 8bc. for each position.  In the following example, ‘MyIterable’ is
not generic but implicitly inherits from ‘Iterable[Any]’:

     from collections.abc import Iterable

     class MyIterable(Iterable): # Same as Iterable[Any]
         ...

User-defined generic type aliases are also supported.  Examples:

     from collections.abc import Iterable

     type Response[S] = Iterable[S] | int

     # Return type here is same as Iterable[str] | int
     def response(query: str) -> Response[str]:
         ...

     type Vec[T] = Iterable[tuple[T, T]]

     def inproduct[T: (int, float, complex)](v: Vec[T]) -> T: # Same as Iterable[tuple[T, T]]
         return sum(x*y for x, y in v)

For backward compatibility, generic type aliases can also be created
through a simple assignment:

     from collections.abc import Iterable
     from typing import TypeVar

     S = TypeVar("S")
     Response = Iterable[S] | int

Cambiato nella versione 3.7: *note Generic: 179e. no longer has a custom
metaclass.

Cambiato nella versione 3.12: Syntactic support for generics and type
aliases is new in version 3.12.  Previously, generic classes had to
explicitly inherit from *note Generic: 179e. or contain a type variable
in one of their bases.

User-defined generics for parameter expressions are also supported via
parameter specification variables in the form ‘[**P]’.  The behavior is
consistent with type variables” described above as parameter
specification variables are treated by the ‘typing’ module as a
specialized type variable.  The one exception to this is that a list of
types can be used to substitute a *note ParamSpec: 488.:

     >>> class Z[T, **P]: ...  # T is a TypeVar; P is a ParamSpec
     ...
     >>> Z[int, [dict, float]]
     __main__.Z[int, [dict, float]]

Classes generic over a *note ParamSpec: 488. can also be created using
explicit inheritance from *note Generic: 179e.  In this case, ‘**’ is
not used:

     from typing import ParamSpec, Generic

     P = ParamSpec('P')

     class Z(Generic[P]):
         ...

Another difference between *note TypeVar: 487. and *note ParamSpec: 488.
is that a generic with only one parameter specification variable will
accept parameter lists in the forms ‘X[[Type1, Type2, ...]]’ and also
‘X[Type1, Type2, ...]’ for aesthetic reasons.  Internally, the latter is
converted to the former, so the following are equivalent:

     >>> class X[**P]: ...
     ...
     >>> X[int, str]
     __main__.X[[int, str]]
     >>> X[[int, str]]
     __main__.X[[int, str]]

Note that generics with *note ParamSpec: 488. may not have correct
‘__parameters__’ after substitution in some cases because they are
intended primarily for static type checking.

Cambiato nella versione 3.10: *note Generic: 179e. can now be
parameterized over parameter expressions.  See *note ParamSpec: 488. and
PEP 612(1) for more details.

A user-defined generic class can have ABCs as base classes without a
metaclass conflict.  Generic metaclasses are not supported.  The outcome
of parameterizing generics is cached, and most types in the ‘typing’
module are *note hashable: 825. and comparable for equality.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0612/


File: python.info,  Node: The Any type,  Next: Nominal vs structural subtyping,  Prev: User-defined generic types,  Up: typing — Support for type hints

5.26.1.10 The ‘Any’ type
........................

A special kind of type is *note Any: 8bc.  A static type checker will
treat every type as being compatible with *note Any: 8bc. and *note Any:
8bc. as being compatible with every type.

This means that it is possible to perform any operation or method call
on a value of type *note Any: 8bc. and assign it to any variable:

     from typing import Any

     a: Any = None
     a = []          # OK
     a = 2           # OK

     s: str = ''
     s = a           # OK

     def foo(item: Any) -> int:
         # Passes type checking; 'item' could be any type,
         # and that type might have a 'bar' method
         item.bar()
         ...

Notice that no type checking is performed when assigning a value of type
*note Any: 8bc. to a more precise type.  For example, the static type
checker did not report an error when assigning ‘a’ to ‘s’ even though
‘s’ was declared to be of type *note str: 169. and receives an *note
int: 19b. value at runtime!

Furthermore, all functions without a return type or parameter types will
implicitly default to using *note Any: 8bc.:

     def legacy_parser(text):
         ...
         return data

     # A static type checker will treat the above
     # as having the same signature as:
     def legacy_parser(text: Any) -> Any:
         ...
         return data

This behavior allows *note Any: 8bc. to be used as an 'escape hatch'
when you need to mix dynamically and statically typed code.

Contrast the behavior of *note Any: 8bc. with the behavior of *note
object: c80.  Similar to *note Any: 8bc, every type is a subtype of
*note object: c80.  However, unlike *note Any: 8bc, the reverse is not
true: *note object: c80. is 'not' a subtype of every other type.

That means when the type of a value is *note object: c80, a type checker
will reject almost all operations on it, and assigning it to a variable
(or using it as a return value) of a more specialized type is a type
error.  For example:

     def hash_a(item: object) -> int:
         # Fails type checking; an object does not have a 'magic' method.
         item.magic()
         ...

     def hash_b(item: Any) -> int:
         # Passes type checking
         item.magic()
         ...

     # Passes type checking, since ints and strs are subclasses of object
     hash_a(42)
     hash_a("foo")

     # Passes type checking, since Any is compatible with all types
     hash_b(42)
     hash_b("foo")

Use *note object: c80. to indicate that a value could be any type in a
typesafe manner.  Use *note Any: 8bc. to indicate that a value is
dynamically typed.


File: python.info,  Node: Nominal vs structural subtyping,  Next: Module contents<3>,  Prev: The Any type,  Up: typing — Support for type hints

5.26.1.11 Nominal vs structural subtyping
.........................................

Initially PEP 484(1) defined the Python static type system as using
'nominal subtyping'.  This means that a class ‘A’ is allowed where a
class ‘B’ is expected if and only if ‘A’ is a subclass of ‘B’.

This requirement previously also applied to abstract base classes, such
as *note Iterable: 2691.  The problem with this approach is that a class
had to be explicitly marked to support them, which is unpythonic and
unlike what one would normally do in idiomatic dynamically typed Python
code.  For example, this conforms to PEP 484(2):

     from collections.abc import Sized, Iterable, Iterator

     class Bucket(Sized, Iterable[int]):
         ...
         def __len__(self) -> int: ...
         def __iter__(self) -> Iterator[int]: ...

PEP 544(3) allows to solve this problem by allowing users to write the
above code without explicit base classes in the class definition,
allowing ‘Bucket’ to be implicitly considered a subtype of both ‘Sized’
and ‘Iterable[int]’ by static type checkers.  This is known as
'structural subtyping' (or static duck-typing):

     from collections.abc import Iterator, Iterable

     class Bucket:  # Note: no base classes
         ...
         def __len__(self) -> int: ...
         def __iter__(self) -> Iterator[int]: ...

     def collect(items: Iterable[int]) -> int: ...
     result = collect(Bucket())  # Passes type check

Moreover, by subclassing a special class *note Protocol: 56b, a user can
define new custom protocols to fully enjoy structural subtyping (see
examples below).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0484/

   (3) https://peps.python.org/pep-0544/


File: python.info,  Node: Module contents<3>,  Next: Deprecation Timeline of Major Features,  Prev: Nominal vs structural subtyping,  Up: typing — Support for type hints

5.26.1.12 Module contents
.........................

The ‘typing’ module defines the following classes, functions and
decorators.

* Menu:

* Special typing primitives::
* Protocols: Protocols<4>.
* ABCs and Protocols for working with I/O::
* Functions and decorators::
* Introspection helpers::
* Constant::
* Deprecated aliases::


File: python.info,  Node: Special typing primitives,  Next: Protocols<4>,  Up: Module contents<3>

5.26.1.13 Special typing primitives
...................................

* Menu:

* Special types::
* Special forms::
* Building generic types and type aliases::
* Other special directives::


File: python.info,  Node: Special types,  Next: Special forms,  Up: Special typing primitives

5.26.1.14 Special types
.......................

These can be used as types in annotations.  They do not support
subscription using ‘[]’.

 -- Dati: typing.Any

     Special type indicating an unconstrained type.

        * Every type is compatible with *note Any: 8bc.

        * *note Any: 8bc. is compatible with every type.

     Cambiato nella versione 3.11: *note Any: 8bc. can now be used as a
     base class.  This can be useful for avoiding type checker errors
     with classes that can duck type anywhere or are highly dynamic.

 -- Dati: typing.AnyStr

     A *note constrained type variable: 44cb.

     Definition:

          AnyStr = TypeVar('AnyStr', str, bytes)

     ‘AnyStr’ is meant to be used for functions that may accept *note
     str: 169. or *note bytes: 192. arguments but cannot allow the two
     to mix.

     For example:

          def concat(a: AnyStr, b: AnyStr) -> AnyStr:
              return a + b

          concat("foo", "bar")    # OK, output has type 'str'
          concat(b"foo", b"bar")  # OK, output has type 'bytes'
          concat("foo", b"bar")   # Error, cannot mix str and bytes

     Note that, despite its name, ‘AnyStr’ has nothing to do with the
     *note Any: 8bc. type, nor does it mean «any string».  In
     particular, ‘AnyStr’ and ‘str | bytes’ are different from each
     other and have different use cases:

          # Invalid use of AnyStr:
          # The type variable is used only once in the function signature,
          # so cannot be "solved" by the type checker
          def greet_bad(cond: bool) -> AnyStr:
              return "hi there!" if cond else b"greetings!"

          # The better way of annotating this function:
          def greet_proper(cond: bool) -> str | bytes:
              return "hi there!" if cond else b"greetings!"

     Deprecated since version 3.13, will be removed in version 3.18:
     Deprecated in favor of the new *note type parameter syntax: 5ad.
     Use ‘class A[T: (str, bytes)]: ...’ instead of importing ‘AnyStr’.
     See PEP 695(1) for more details.

     In Python 3.16, ‘AnyStr’ will be removed from ‘typing.__all__’, and
     deprecation warnings will be emitted at runtime when it is accessed
     or imported from ‘typing’.  ‘AnyStr’ will be removed from ‘typing’
     in Python 3.18.

 -- Dati: typing.LiteralString

     Special type that includes only literal strings.

     Any string literal is compatible with ‘LiteralString’, as is
     another ‘LiteralString’.  However, an object typed as just ‘str’ is
     not.  A string created by composing ‘LiteralString’-typed objects
     is also acceptable as a ‘LiteralString’.

     Example:

          def run_query(sql: LiteralString) -> None:
              ...

          def caller(arbitrary_string: str, literal_string: LiteralString) -> None:
              run_query("SELECT * FROM students")  # OK
              run_query(literal_string)  # OK
              run_query("SELECT * FROM " + literal_string)  # OK
              run_query(arbitrary_string)  # type checker error
              run_query(  # type checker error
                  f"SELECT * FROM students WHERE name = {arbitrary_string}"
              )

     ‘LiteralString’ is useful for sensitive APIs where arbitrary
     user-generated strings could generate problems.  For example, the
     two cases above that generate type checker errors could be
     vulnerable to an SQL injection attack.

     See PEP 675(2) for more details.

     Added in version 3.11.

 -- Dati: typing.Never
 -- Dati: typing.NoReturn

     ‘Never’ and ‘NoReturn’ represent the bottom type(3), a type that
     has no members.

     They can be used to indicate that a function never returns, such as
     *note sys.exit(): 277.:

          from typing import Never  # or NoReturn

          def stop() -> Never:
              raise RuntimeError('no way')

     Or to define a function that should never be called, as there are
     no valid arguments, such as *note assert_never(): 8b7.:

          from typing import Never  # or NoReturn

          def never_call_me(arg: Never) -> None:
              pass

          def int_or_str(arg: int | str) -> None:
              never_call_me(arg)  # type checker error
              match arg:
                  case int():
                      print("It's an int")
                  case str():
                      print("It's a str")
                  case _:
                      never_call_me(arg)  # OK, arg is of type Never (or NoReturn)

     ‘Never’ and ‘NoReturn’ have the same meaning in the type system and
     static type checkers treat both equivalently.

     Added in version 3.6.2: Added *note NoReturn: 44cc.

     Added in version 3.11: Added *note Never: 8b8.

 -- Dati: typing.Self

     Special type to represent the current enclosed class.

     For example:

          from typing import Self, reveal_type

          class Foo:
              def return_self(self) -> Self:
                  ...
                  return self

          class SubclassOfFoo(Foo): pass

          reveal_type(Foo().return_self())  # Revealed type is "Foo"
          reveal_type(SubclassOfFoo().return_self())  # Revealed type is "SubclassOfFoo"

     This annotation is semantically equivalent to the following, albeit
     in a more succinct fashion:

          from typing import TypeVar

          Self = TypeVar("Self", bound="Foo")

          class Foo:
              def return_self(self: Self) -> Self:
                  ...
                  return self

     In general, if something returns ‘self’, as in the above examples,
     you should use ‘Self’ as the return annotation.  If
     ‘Foo.return_self’ was annotated as returning ‘"Foo"’, then the type
     checker would infer the object returned from
     ‘SubclassOfFoo.return_self’ as being of type ‘Foo’ rather than
     ‘SubclassOfFoo’.

     Other common use cases include:

        - *note classmethod: 48f.s that are used as alternative
          constructors and return instances of the ‘cls’ parameter.

        - Annotating an *note __enter__(): 7e5. method which returns
          self.

     You should not use ‘Self’ as the return annotation if the method is
     not guaranteed to return an instance of a subclass when the class
     is subclassed:

          class Eggs:
              # Self would be an incorrect return annotation here,
              # as the object returned is always an instance of Eggs,
              # even in subclasses
              def returns_eggs(self) -> "Eggs":
                  return Eggs()

     See PEP 673(4) for more details.

     Added in version 3.11.

 -- Dati: typing.TypeAlias

     Special annotation for explicitly declaring a *note type alias:
     684.

     For example:

          from typing import TypeAlias

          Factors: TypeAlias = list[int]

     ‘TypeAlias’ is particularly useful on older Python versions for
     annotating aliases that make use of forward references, as it can
     be hard for type checkers to distinguish these from normal variable
     assignments:

          from typing import Generic, TypeAlias, TypeVar

          T = TypeVar("T")

          # "Box" does not exist yet,
          # so we have to use quotes for the forward reference on Python <3.12.
          # Using ``TypeAlias`` tells the type checker that this is a type alias declaration,
          # not a variable assignment to a string.
          BoxOfStrings: TypeAlias = "Box[str]"

          class Box(Generic[T]):
              @classmethod
              def make_box_of_strings(cls) -> BoxOfStrings: ...

     See PEP 613(5) for more details.

     Added in version 3.10.

     Deprecato dalla versione 3.12: *note TypeAlias: 9ce. is deprecated
     in favor of the *note type: 66d. statement, which creates instances
     of *note TypeAliasType: 2ae. and which natively supports forward
     references.  Note that while *note TypeAlias: 9ce. and *note
     TypeAliasType: 2ae. serve similar purposes and have similar names,
     they are distinct and the latter is not the type of the former.
     Removal of *note TypeAlias: 9ce. is not currently planned, but
     users are encouraged to migrate to *note type: 66d. statements.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0695/

   (2) https://peps.python.org/pep-0675/

   (3) https://en.wikipedia.org/wiki/Bottom_type

   (4) https://peps.python.org/pep-0673/

   (5) https://peps.python.org/pep-0613/


File: python.info,  Node: Special forms,  Next: Building generic types and type aliases,  Prev: Special types,  Up: Special typing primitives

5.26.1.15 Special forms
.......................

These can be used as types in annotations.  They all support
subscription using ‘[]’, but each has a unique syntax.

 -- Classe: typing.Union

     Union type; ‘Union[X, Y]’ is equivalent to ‘X | Y’ and means either
     X or Y.

     To define a union, use e.g.  ‘Union[int, str]’ or the shorthand
     ‘int | str’.  Using that shorthand is recommended.  Details:

        * The arguments must be types and there must be at least one.

        * Unions of unions are flattened, e.g.:

               Union[Union[int, str], float] == Union[int, str, float]

          However, this does not apply to unions referenced through a
          type alias, to avoid forcing evaluation of the underlying
          *note TypeAliasType: 2ae.:

               type A = Union[int, str]
               Union[A, float] != Union[int, str, float]

        * Unions of a single argument vanish, e.g.:

               Union[int] == int  # The constructor actually returns int

        * Redundant arguments are skipped, e.g.:

               Union[int, str, int] == Union[int, str] == int | str

        * When comparing unions, the argument order is ignored, e.g.:

               Union[int, str] == Union[str, int]

        * You cannot subclass or instantiate a ‘Union’.

        * You cannot write ‘Union[X][Y]’.

     Cambiato nella versione 3.7: Don’t remove explicit subclasses from
     unions at runtime.

     Cambiato nella versione 3.10: Unions can now be written as ‘X | Y’.
     See *note union type expressions: 9c7.

     Cambiato nella versione 3.14: *note types.UnionType: 2a7. is now an
     alias for *note Union: 2a8, and both ‘Union[int, str]’ and ‘int |
     str’ create instances of the same class.  To check whether an
     object is a ‘Union’ at runtime, use ‘isinstance(obj, Union)’.  For
     compatibility with earlier versions of Python, use ‘get_origin(obj)
     is typing.Union or get_origin(obj) is types.UnionType’.

 -- Dati: typing.Optional

     ‘Optional[X]’ is equivalent to ‘X | None’ (or ‘Union[X, None]’).

     Note that this is not the same concept as an optional argument,
     which is one that has a default.  An optional argument with a
     default does not require the ‘Optional’ qualifier on its type
     annotation just because it is optional.  For example:

          def foo(arg: int = 0) -> None:
              ...

     On the other hand, if an explicit value of ‘None’ is allowed, the
     use of ‘Optional’ is appropriate, whether the argument is optional
     or not.  For example:

          def foo(arg: Optional[int] = None) -> None:
              ...

     Cambiato nella versione 3.10: Optional can now be written as ‘X |
     None’.  See *note union type expressions: 9c7.

 -- Dati: typing.Concatenate

     Special form for annotating higher-order functions.

     ‘Concatenate’ can be used in conjunction with *note Callable: 26b2.
     and *note ParamSpec: 488. to annotate a higher-order callable which
     adds, removes, or transforms parameters of another callable.  Usage
     is in the form ‘Concatenate[Arg1Type, Arg2Type, ...,
     ParamSpecVariable]’.  ‘Concatenate’ is currently only valid when
     used as the first argument to a *note Callable: 26b2.  The last
     parameter to ‘Concatenate’ must be a *note ParamSpec: 488. or
     ellipsis (‘...’).

     For example, to annotate a decorator ‘with_lock’ which provides a
     *note threading.Lock: 19dc. to the decorated function,
     ‘Concatenate’ can be used to indicate that ‘with_lock’ expects a
     callable which takes in a ‘Lock’ as the first argument, and returns
     a callable with a different type signature.  In this case, the
     *note ParamSpec: 488. indicates that the returned callable’s
     parameter types are dependent on the parameter types of the
     callable being passed in:

          from collections.abc import Callable
          from threading import Lock
          from typing import Concatenate

          # Use this lock to ensure that only one thread is executing a function
          # at any time.
          my_lock = Lock()

          def with_lock[**P, R](f: Callable[Concatenate[Lock, P], R]) -> Callable[P, R]:
              '''A type-safe decorator which provides a lock.'''
              def inner(*args: P.args, **kwargs: P.kwargs) -> R:
                  # Provide the lock as the first argument.
                  return f(my_lock, *args, **kwargs)
              return inner

          @with_lock
          def sum_threadsafe(lock: Lock, numbers: list[float]) -> float:
              '''Add a list of numbers together in a thread-safe manner.'''
              with lock:
                  return sum(numbers)

          # We don't need to pass in the lock ourselves thanks to the decorator.
          sum_threadsafe([1.1, 2.2, 3.3])

     Added in version 3.10.

     Vedi anche
     ..........

        * PEP 612(1) – Parameter Specification Variables (the PEP which
          introduced ‘ParamSpec’ and ‘Concatenate’)

        * *note ParamSpec: 488.

        * *note Annotating callable objects: 26b2.

 -- Dati: typing.Literal

     Special typing form to define «literal types».

     ‘Literal’ can be used to indicate to type checkers that the
     annotated object has a value equivalent to one of the provided
     literals.

     For example:

          def validate_simple(data: Any) -> Literal[True]:  # always returns True
              ...

          type Mode = Literal['r', 'rb', 'w', 'wb']
          def open_helper(file: str, mode: Mode) -> str:
              ...

          open_helper('/some/path', 'r')      # Passes type check
          open_helper('/other/path', 'typo')  # Error in type checker

     ‘Literal[...]’ cannot be subclassed.  At runtime, an arbitrary
     value is allowed as type argument to ‘Literal[...]’, but type
     checkers may impose restrictions.  See PEP 586(2) for more details
     about literal types.

     Additional details:

        * The arguments must be literal values and there must be at
          least one.

        * Nested ‘Literal’ types are flattened, e.g.:

               assert Literal[Literal[1, 2], 3] == Literal[1, 2, 3]

          However, this does not apply to ‘Literal’ types referenced
          through a type alias, to avoid forcing evaluation of the
          underlying *note TypeAliasType: 2ae.:

               type A = Literal[1, 2]
               assert Literal[A, 3] != Literal[1, 2, 3]

        * Redundant arguments are skipped, e.g.:

               assert Literal[1, 2, 1] == Literal[1, 2]

        * When comparing literals, the argument order is ignored, e.g.:

               assert Literal[1, 2] == Literal[2, 1]

        * You cannot subclass or instantiate a ‘Literal’.

        * You cannot write ‘Literal[X][Y]’.

     Added in version 3.8.

     Cambiato nella versione 3.9.1: ‘Literal’ now de-duplicates
     parameters.  Equality comparisons of ‘Literal’ objects are no
     longer order dependent.  ‘Literal’ objects will now raise a *note
     TypeError: 198. exception during equality comparisons if one of
     their parameters are not *note hashable: 825.

 -- Dati: typing.ClassVar

     Special type construct to mark class variables.

     As introduced in PEP 526(3), a variable annotation wrapped in
     ClassVar indicates that a given attribute is intended to be used as
     a class variable and should not be set on instances of that class.
     Usage:

          class Starship:
              stats: ClassVar[dict[str, int]] = {} # class variable
              damage: int = 10                     # instance variable

     *note ClassVar: 56d. accepts only types and cannot be further
     subscribed.

     *note ClassVar: 56d. is not a class itself, and should not be used
     with *note isinstance(): 2ad. or *note issubclass(): 9c6.  *note
     ClassVar: 56d. does not change Python runtime behavior, but it can
     be used by third-party type checkers.  For example, a type checker
     might flag the following code as an error:

          enterprise_d = Starship(3000)
          enterprise_d.stats = {} # Error, setting class variable on instance
          Starship.stats = {}     # This is OK

     Added in version 3.5.3.

     Cambiato nella versione 3.13: *note ClassVar: 56d. can now be
     nested in *note Final: 56e. and vice versa.

 -- Dati: typing.Final

     Special typing construct to indicate final names to type checkers.

     Final names cannot be reassigned in any scope.  Final names
     declared in class scopes cannot be overridden in subclasses.

     For example:

          MAX_SIZE: Final = 9000
          MAX_SIZE += 1  # Error reported by type checker

          class Connection:
              TIMEOUT: Final[int] = 10

          class FastConnector(Connection):
              TIMEOUT = 1  # Error reported by type checker

     There is no runtime checking of these properties.  See PEP 591(4)
     for more details.

     Added in version 3.8.

     Cambiato nella versione 3.13: *note Final: 56e. can now be nested
     in *note ClassVar: 56d. and vice versa.

 -- Dati: typing.Required

     Special typing construct to mark a *note TypedDict: 332. key as
     required.

     This is mainly useful for ‘total=False’ TypedDicts.  See *note
     TypedDict: 332. and PEP 655(5) for more details.

     Added in version 3.11.

 -- Dati: typing.NotRequired

     Special typing construct to mark a *note TypedDict: 332. key as
     potentially missing.

     See *note TypedDict: 332. and PEP 655(6) for more details.

     Added in version 3.11.

 -- Dati: typing.ReadOnly

     A special typing construct to mark an item of a *note TypedDict:
     332. as read-only.

     For example:

          class Movie(TypedDict):
             title: ReadOnly[str]
             year: int

          def mutate_movie(m: Movie) -> None:
             m["year"] = 1999  # allowed
             m["title"] = "The Matrix"  # typechecker error

     There is no runtime checking for this property.

     See *note TypedDict: 332. and PEP 705(7) for more details.

     Added in version 3.13.

 -- Dati: typing.Annotated

     Special typing form to add context-specific metadata to an
     annotation.

     Add metadata ‘x’ to a given type ‘T’ by using the annotation
     ‘Annotated[T, x]’.  Metadata added using ‘Annotated’ can be used by
     static analysis tools or at runtime.  At runtime, the metadata is
     stored in a ‘__metadata__’ attribute.

     If a library or tool encounters an annotation ‘Annotated[T, x]’ and
     has no special logic for the metadata, it should ignore the
     metadata and simply treat the annotation as ‘T’.  As such,
     ‘Annotated’ can be useful for code that wants to use annotations
     for purposes outside Python’s static typing system.

     Using ‘Annotated[T, x]’ as an annotation still allows for static
     typechecking of ‘T’, as type checkers will simply ignore the
     metadata ‘x’.  In this way, ‘Annotated’ differs from the *note
     @no_type_check: 8c4. decorator, which can also be used for adding
     annotations outside the scope of the typing system, but completely
     disables typechecking for a function or class.

     The responsibility of how to interpret the metadata lies with the
     tool or library encountering an ‘Annotated’ annotation.  A tool or
     library encountering an ‘Annotated’ type can scan through the
     metadata elements to determine if they are of interest (e.g., using
     *note isinstance(): 2ad.).

      -- Describe: Annotated[<type>, <metadata>]

     Here is an example of how you might use ‘Annotated’ to add metadata
     to type annotations if you were doing range analysis:

          @dataclass
          class ValueRange:
              lo: int
              hi: int

          T1 = Annotated[int, ValueRange(-10, 5)]
          T2 = Annotated[T1, ValueRange(-20, 3)]

     The first argument to ‘Annotated’ must be a valid type.  Multiple
     metadata elements can be supplied as ‘Annotated’ supports variadic
     arguments.  The order of the metadata elements is preserved and
     matters for equality checks:

          @dataclass
          class ctype:
               kind: str

          a1 = Annotated[int, ValueRange(3, 10), ctype("char")]
          a2 = Annotated[int, ctype("char"), ValueRange(3, 10)]

          assert a1 != a2  # Order matters

     It is up to the tool consuming the annotations to decide whether
     the client is allowed to add multiple metadata elements to one
     annotation and how to merge those annotations.

     Nested ‘Annotated’ types are flattened.  The order of the metadata
     elements starts with the innermost annotation:

          assert Annotated[Annotated[int, ValueRange(3, 10)], ctype("char")] == Annotated[
              int, ValueRange(3, 10), ctype("char")
          ]

     However, this does not apply to ‘Annotated’ types referenced
     through a type alias, to avoid forcing evaluation of the underlying
     *note TypeAliasType: 2ae.:

          type From3To10[T] = Annotated[T, ValueRange(3, 10)]
          assert Annotated[From3To10[int], ctype("char")] != Annotated[
             int, ValueRange(3, 10), ctype("char")
          ]

     Duplicated metadata elements are not removed:

          assert Annotated[int, ValueRange(3, 10)] != Annotated[
              int, ValueRange(3, 10), ValueRange(3, 10)
          ]

     ‘Annotated’ can be used with nested and generic aliases:

               @dataclass
               class MaxLen:
                   value: int

               type Vec[T] = Annotated[list[tuple[T, T]], MaxLen(10)]

               # When used in a type annotation, a type checker will treat "V" the same as
               # ``Annotated[list[tuple[int, int]], MaxLen(10)]``:
               type V = Vec[int]

     ‘Annotated’ cannot be used with an unpacked *note TypeVarTuple:
     489.:

          type Variadic[*Ts] = Annotated[*Ts, Ann1] = Annotated[T1, T2, T3, ..., Ann1]  # NOT valid

     where ‘T1’, ‘T2’, … are *note TypeVars: 487.  This is invalid as
     only one type should be passed to Annotated.

     By default, *note get_type_hints(): 8c1. strips the metadata from
     annotations.  Pass ‘include_extras=True’ to have the metadata
     preserved:

               >>> from typing import Annotated, get_type_hints
               >>> def func(x: Annotated[int, "metadata"]) -> None: pass
               ...
               >>> get_type_hints(func)
               {'x': <class 'int'>, 'return': <class 'NoneType'>}
               >>> get_type_hints(func, include_extras=True)
               {'x': typing.Annotated[int, 'metadata'], 'return': <class 'NoneType'>}

     At runtime, the metadata associated with an ‘Annotated’ type can be
     retrieved via the ‘__metadata__’ attribute:

               >>> from typing import Annotated
               >>> X = Annotated[int, "very", "important", "metadata"]
               >>> X
               typing.Annotated[int, 'very', 'important', 'metadata']
               >>> X.__metadata__
               ('very', 'important', 'metadata')

     If you want to retrieve the original type wrapped by ‘Annotated’,
     use the ‘__origin__’ attribute:

               >>> from typing import Annotated, get_origin
               >>> Password = Annotated[str, "secret"]
               >>> Password.__origin__
               <class 'str'>

     Note that using *note get_origin(): 2ab. will return ‘Annotated’
     itself:

               >>> get_origin(Password)
               typing.Annotated

     Vedi anche
     ..........

     PEP 593(8) - Flexible function and variable annotations

          The PEP introducing ‘Annotated’ to the standard library.

     Added in version 3.9.

 -- Dati: typing.TypeIs

     Special typing construct for marking user-defined type predicate
     functions.

     ‘TypeIs’ can be used to annotate the return type of a user-defined
     type predicate function.  ‘TypeIs’ only accepts a single type
     argument.  At runtime, functions marked this way should return a
     boolean and take at least one positional argument.

     ‘TypeIs’ aims to benefit 'type narrowing' – a technique used by
     static type checkers to determine a more precise type of an
     expression within a program’s code flow.  Usually type narrowing is
     done by analyzing conditional code flow and applying the narrowing
     to a block of code.  The conditional expression here is sometimes
     referred to as a «type predicate»:

          def is_str(val: str | float):
              # "isinstance" type predicate
              if isinstance(val, str):
                  # Type of ``val`` is narrowed to ``str``
                  ...
              else:
                  # Else, type of ``val`` is narrowed to ``float``.
                  ...

     Sometimes it would be convenient to use a user-defined boolean
     function as a type predicate.  Such a function should use
     ‘TypeIs[...]’ or *note TypeGuard: 48d. as its return type to alert
     static type checkers to this intention.  ‘TypeIs’ usually has more
     intuitive behavior than ‘TypeGuard’, but it cannot be used when the
     input and output types are incompatible (e.g., ‘list[object]’ to
     ‘list[int]’) or when the function does not return ‘True’ for all
     instances of the narrowed type.

     Using ‘-> TypeIs[NarrowedType]’ tells the static type checker that
     for a given function:

       1. The return value is a boolean.

       2. If the return value is ‘True’, the type of its argument is the
          intersection of the argument’s original type and
          ‘NarrowedType’.

       3. If the return value is ‘False’, the type of its argument is
          narrowed to exclude ‘NarrowedType’.

     For example:

          from typing import assert_type, final, TypeIs

          class Parent: pass
          class Child(Parent): pass
          @final
          class Unrelated: pass

          def is_parent(val: object) -> TypeIs[Parent]:
              return isinstance(val, Parent)

          def run(arg: Child | Unrelated):
              if is_parent(arg):
                  # Type of ``arg`` is narrowed to the intersection
                  # of ``Parent`` and ``Child``, which is equivalent to
                  # ``Child``.
                  assert_type(arg, Child)
              else:
                  # Type of ``arg`` is narrowed to exclude ``Parent``,
                  # so only ``Unrelated`` is left.
                  assert_type(arg, Unrelated)

     The type inside ‘TypeIs’ must be consistent with the type of the
     function’s argument; if it is not, static type checkers will raise
     an error.  An incorrectly written ‘TypeIs’ function can lead to
     unsound behavior in the type system; it is the user’s
     responsibility to write such functions in a type-safe manner.

     If a ‘TypeIs’ function is a class or instance method, then the type
     in ‘TypeIs’ maps to the type of the second parameter (after ‘cls’
     or ‘self’).

     In short, the form ‘def foo(arg: TypeA) -> TypeIs[TypeB]: ...’,
     means that if ‘foo(arg)’ returns ‘True’, then ‘arg’ is an instance
     of ‘TypeB’, and if it returns ‘False’, it is not an instance of
     ‘TypeB’.

     ‘TypeIs’ also works with type variables.  For more information, see
     PEP 742(9) (Narrowing types with ‘TypeIs’).

     Added in version 3.13.

 -- Dati: typing.TypeGuard

     Special typing construct for marking user-defined type predicate
     functions.

     Type predicate functions are user-defined functions that return
     whether their argument is an instance of a particular type.
     ‘TypeGuard’ works similarly to *note TypeIs: 48c, but has subtly
     different effects on type checking behavior (see below).

     Using ‘-> TypeGuard’ tells the static type checker that for a given
     function:

       1. The return value is a boolean.

       2. If the return value is ‘True’, the type of its argument is the
          type inside ‘TypeGuard’.

     ‘TypeGuard’ also works with type variables.  See PEP 647(10) for
     more details.

     For example:

          def is_str_list(val: list[object]) -> TypeGuard[list[str]]:
              '''Determines whether all objects in the list are strings'''
              return all(isinstance(x, str) for x in val)

          def func1(val: list[object]):
              if is_str_list(val):
                  # Type of ``val`` is narrowed to ``list[str]``.
                  print(" ".join(val))
              else:
                  # Type of ``val`` remains as ``list[object]``.
                  print("Not a list of strings!")

     ‘TypeIs’ and ‘TypeGuard’ differ in the following ways:

        * ‘TypeIs’ requires the narrowed type to be a subtype of the
          input type, while ‘TypeGuard’ does not.  The main reason is to
          allow for things like narrowing ‘list[object]’ to ‘list[str]’
          even though the latter is not a subtype of the former, since
          ‘list’ is invariant.

        * When a ‘TypeGuard’ function returns ‘True’, type checkers
          narrow the type of the variable to exactly the ‘TypeGuard’
          type.  When a ‘TypeIs’ function returns ‘True’, type checkers
          can infer a more precise type combining the previously known
          type of the variable with the ‘TypeIs’ type.  (Technically,
          this is known as an intersection type.)

        * When a ‘TypeGuard’ function returns ‘False’, type checkers
          cannot narrow the type of the variable at all.  When a
          ‘TypeIs’ function returns ‘False’, type checkers can narrow
          the type of the variable to exclude the ‘TypeIs’ type.

     Added in version 3.10.

 -- Dati: typing.Unpack

     Typing operator to conceptually mark an object as having been
     unpacked.

     For example, using the unpack operator ‘*’ on a *note type variable
     tuple: 44ce. is equivalent to using ‘Unpack’ to mark the type
     variable tuple as having been unpacked:

          Ts = TypeVarTuple('Ts')
          tup: tuple[*Ts]
          # Effectively does:
          tup: tuple[Unpack[Ts]]

     In fact, ‘Unpack’ can be used interchangeably with ‘*’ in the
     context of *note typing.TypeVarTuple: 489. and *note
     builtins.tuple: 614. types.  You might see ‘Unpack’ being used
     explicitly in older versions of Python, where ‘*’ couldn’t be used
     in certain places:

          # In older versions of Python, TypeVarTuple and Unpack
          # are located in the `typing_extensions` backports package.
          from typing_extensions import TypeVarTuple, Unpack

          Ts = TypeVarTuple('Ts')
          tup: tuple[*Ts]         # Syntax error on Python <= 3.10!
          tup: tuple[Unpack[Ts]]  # Semantically equivalent, and backwards-compatible

     ‘Unpack’ can also be used along with *note typing.TypedDict: 332.
     for typing ‘**kwargs’ in a function signature:

          from typing import TypedDict, Unpack

          class Movie(TypedDict):
              name: str
              year: int

          # This function expects two keyword arguments - `name` of type `str`
          # and `year` of type `int`.
          def foo(**kwargs: Unpack[Movie]): ...

     See PEP 692(11) for more details on using ‘Unpack’ for ‘**kwargs’
     typing.

     Added in version 3.11.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0612/

   (2) https://peps.python.org/pep-0586/

   (3) https://peps.python.org/pep-0526/

   (4) https://peps.python.org/pep-0591/

   (5) https://peps.python.org/pep-0655/

   (6) https://peps.python.org/pep-0655/

   (7) https://peps.python.org/pep-0705/

   (8) https://peps.python.org/pep-0593/

   (9) https://peps.python.org/pep-0742/

   (10) https://peps.python.org/pep-0647/

   (11) https://peps.python.org/pep-0692/


File: python.info,  Node: Building generic types and type aliases,  Next: Other special directives,  Prev: Special forms,  Up: Special typing primitives

5.26.1.16 Building generic types and type aliases
.................................................

The following classes should not be used directly as annotations.  Their
intended purpose is to be building blocks for creating generic types and
type aliases.

These objects can be created through special syntax (*note type
parameter lists: 5ad. and the *note type: 66d. statement).  For
compatibility with Python 3.11 and earlier, they can also be created
without the dedicated syntax, as documented below.

 -- Classe: typing.Generic

     Abstract base class for generic types.

     A generic type is typically declared by adding a list of type
     parameters after the class name:

          class Mapping[KT, VT]:
              def __getitem__(self, key: KT) -> VT:
                  ...
                  # Etc.

     Such a class implicitly inherits from ‘Generic’.  The runtime
     semantics of this syntax are discussed in the *note Language
     Reference: 682.

     This class can then be used as follows:

          def lookup_name[X, Y](mapping: Mapping[X, Y], key: X, default: Y) -> Y:
              try:
                  return mapping[key]
              except KeyError:
                  return default

     Here the brackets after the function name indicate a *note generic
     function: 683.

     For backwards compatibility, generic classes can also be declared
     by explicitly inheriting from ‘Generic’.  In this case, the type
     parameters must be declared separately:

          KT = TypeVar('KT')
          VT = TypeVar('VT')

          class Mapping(Generic[KT, VT]):
              def __getitem__(self, key: KT) -> VT:
                  ...
                  # Etc.

 -- Classe: typing.TypeVar (name, *constraints, bound=None,
          covariant=False, contravariant=False, infer_variance=False,
          default=typing.NoDefault)

     Type variable.

     The preferred way to construct a type variable is via the dedicated
     syntax for *note generic functions: 683, *note generic classes:
     682, and *note generic type aliases: 685.:

          class Sequence[T]:  # T is a TypeVar
              ...

     This syntax can also be used to create bounded and constrained type
     variables:

          class StrSequence[S: str]:  # S is a TypeVar with a `str` upper bound;
              ...                     # we can say that S is "bounded by `str`"


          class StrOrBytesSequence[A: (str, bytes)]:  # A is a TypeVar constrained to str or bytes
              ...

     However, if desired, reusable type variables can also be
     constructed manually, like so:

          T = TypeVar('T')  # Can be anything
          S = TypeVar('S', bound=str)  # Can be any subtype of str
          A = TypeVar('A', str, bytes)  # Must be exactly str or bytes

     Type variables exist primarily for the benefit of static type
     checkers.  They serve as the parameters for generic types as well
     as for generic function and type alias definitions.  See *note
     Generic: 179e. for more information on generic types.  Generic
     functions work as follows:

          def repeat[T](x: T, n: int) -> Sequence[T]:
              """Return a list containing n references to x."""
              return [x]*n


          def print_capitalized[S: str](x: S) -> S:
              """Print x capitalized, and return x."""
              print(x.capitalize())
              return x


          def concatenate[A: (str, bytes)](x: A, y: A) -> A:
              """Add two strings or bytes objects together."""
              return x + y

     Note that type variables can be 'bounded', 'constrained', or
     neither, but cannot be both bounded 'and' constrained.

     The variance of type variables is inferred by type checkers when
     they are created through the *note type parameter syntax: 5ad. or
     when ‘infer_variance=True’ is passed.  Manually created type
     variables may be explicitly marked covariant or contravariant by
     passing ‘covariant=True’ or ‘contravariant=True’.  By default,
     manually created type variables are invariant.  See PEP 484(1) and
     PEP 695(2) for more details.

     Bounded type variables and constrained type variables have
     different semantics in several important ways.  Using a 'bounded'
     type variable means that the ‘TypeVar’ will be solved using the
     most specific type possible:

          x = print_capitalized('a string')
          reveal_type(x)  # revealed type is str

          class StringSubclass(str):
              pass

          y = print_capitalized(StringSubclass('another string'))
          reveal_type(y)  # revealed type is StringSubclass

          z = print_capitalized(45)  # error: int is not a subtype of str

     The upper bound of a type variable can be a concrete type, abstract
     type (ABC or Protocol), or even a union of types:

          # Can be anything with an __abs__ method
          def print_abs[T: SupportsAbs](arg: T) -> None:
              print("Absolute value:", abs(arg))

          U = TypeVar('U', bound=str|bytes)  # Can be any subtype of the union str|bytes
          V = TypeVar('V', bound=SupportsAbs)  # Can be anything with an __abs__ method
     Using a 'constrained' type variable, however, means that the
     ‘TypeVar’ can only ever be solved as being exactly one of the
     constraints given:

          a = concatenate('one', 'two')
          reveal_type(a)  # revealed type is str

          b = concatenate(StringSubclass('one'), StringSubclass('two'))
          reveal_type(b)  # revealed type is str, despite StringSubclass being passed in

          c = concatenate('one', b'two')  # error: type variable 'A' can be either str or bytes in a function call, but not both

     At runtime, ‘isinstance(x, T)’ will raise *note TypeError: 198.

      -- Attributo: __name__

          The name of the type variable.

      -- Attributo: __covariant__

          Whether the type var has been explicitly marked as covariant.

      -- Attributo: __contravariant__

          Whether the type var has been explicitly marked as
          contravariant.

      -- Attributo: __infer_variance__

          Whether the type variable’s variance should be inferred by
          type checkers.

          Added in version 3.12.

      -- Attributo: __bound__

          The upper bound of the type variable, if any.

          Cambiato nella versione 3.12: For type variables created
          through *note type parameter syntax: 5ad, the bound is
          evaluated only when the attribute is accessed, not when the
          type variable is created (see *note Lazy evaluation: 686.).

      -- Metodo: evaluate_bound ()

          An *note evaluate function: 44d6. corresponding to the *note
          __bound__: 44d4. attribute.  When called directly, this method
          supports only the *note VALUE: 15e. format, which is
          equivalent to accessing the *note __bound__: 44d4. attribute
          directly, but the method object can be passed to *note
          annotationlib.call_evaluate_function(): 44d7. to evaluate the
          value in a different format.

          Added in version 3.14.

      -- Attributo: __constraints__

          A tuple containing the constraints of the type variable, if
          any.

          Cambiato nella versione 3.12: For type variables created
          through *note type parameter syntax: 5ad, the constraints are
          evaluated only when the attribute is accessed, not when the
          type variable is created (see *note Lazy evaluation: 686.).

      -- Metodo: evaluate_constraints ()

          An *note evaluate function: 44d6. corresponding to the *note
          __constraints__: 44d8. attribute.  When called directly, this
          method supports only the *note VALUE: 15e. format, which is
          equivalent to accessing the *note __constraints__: 44d8.
          attribute directly, but the method object can be passed to
          *note annotationlib.call_evaluate_function(): 44d7. to
          evaluate the value in a different format.

          Added in version 3.14.

      -- Attributo: __default__

          The default value of the type variable, or *note
          typing.NoDefault: 569. if it has no default.

          Added in version 3.13.

      -- Metodo: evaluate_default ()

          An *note evaluate function: 44d6. corresponding to the *note
          __default__: 44da. attribute.  When called directly, this
          method supports only the *note VALUE: 15e. format, which is
          equivalent to accessing the *note __default__: 44da. attribute
          directly, but the method object can be passed to *note
          annotationlib.call_evaluate_function(): 44d7. to evaluate the
          value in a different format.

          Added in version 3.14.

      -- Metodo: has_default ()

          Return whether or not the type variable has a default value.
          This is equivalent to checking whether *note __default__:
          44da. is not the *note typing.NoDefault: 569. singleton,
          except that it does not force evaluation of the *note lazily
          evaluated: 686. default value.

          Added in version 3.13.

     Cambiato nella versione 3.12: Type variables can now be declared
     using the *note type parameter: 5ad. syntax introduced by PEP
     695(3).  The ‘infer_variance’ parameter was added.

     Cambiato nella versione 3.13: Support for default values was added.

 -- Classe: typing.TypeVarTuple (name, *, default=typing.NoDefault)

     Type variable tuple.  A specialized form of *note type variable:
     44c5. that enables 'variadic' generics.

     Type variable tuples can be declared in *note type parameter lists:
     5ad. using a single asterisk (‘*’) before the name:

          def move_first_element_to_last[T, *Ts](tup: tuple[T, *Ts]) -> tuple[*Ts, T]:
              return (*tup[1:], tup[0])

     Or by explicitly invoking the ‘TypeVarTuple’ constructor:

          T = TypeVar("T")
          Ts = TypeVarTuple("Ts")

          def move_first_element_to_last(tup: tuple[T, *Ts]) -> tuple[*Ts, T]:
              return (*tup[1:], tup[0])

     A normal type variable enables parameterization with a single type.
     A type variable tuple, in contrast, allows parameterization with an
     'arbitrary' number of types by acting like an 'arbitrary' number of
     type variables wrapped in a tuple.  For example:

          # T is bound to int, Ts is bound to ()
          # Return value is (1,), which has type tuple[int]
          move_first_element_to_last(tup=(1,))

          # T is bound to int, Ts is bound to (str,)
          # Return value is ('spam', 1), which has type tuple[str, int]
          move_first_element_to_last(tup=(1, 'spam'))

          # T is bound to int, Ts is bound to (str, float)
          # Return value is ('spam', 3.0, 1), which has type tuple[str, float, int]
          move_first_element_to_last(tup=(1, 'spam', 3.0))

          # This fails to type check (and fails at runtime)
          # because tuple[()] is not compatible with tuple[T, *Ts]
          # (at least one element is required)
          move_first_element_to_last(tup=())

     Note the use of the unpacking operator ‘*’ in ‘tuple[T, *Ts]’.
     Conceptually, you can think of ‘Ts’ as a tuple of type variables
     ‘(T1, T2, ...)’.  ‘tuple[T, *Ts]’ would then become ‘tuple[T, *(T1,
     T2, ...)]’, which is equivalent to ‘tuple[T, T1, T2, ...]’.  (Note
     that in older versions of Python, you might see this written using
     *note Unpack: 198e. instead, as ‘Unpack[Ts]’.)

     Type variable tuples must 'always' be unpacked.  This helps
     distinguish type variable tuples from normal type variables:

          x: Ts          # Not valid
          x: tuple[Ts]   # Not valid
          x: tuple[*Ts]  # The correct way to do it

     Type variable tuples can be used in the same contexts as normal
     type variables.  For example, in class definitions, arguments, and
     return types:

          class Array[*Shape]:
              def __getitem__(self, key: tuple[*Shape]) -> float: ...
              def __abs__(self) -> "Array[*Shape]": ...
              def get_shape(self) -> tuple[*Shape]: ...

     Type variable tuples can be happily combined with normal type
     variables:

          class Array[DType, *Shape]:  # This is fine
              pass

          class Array2[*Shape, DType]:  # This would also be fine
              pass

          class Height: ...
          class Width: ...

          float_array_1d: Array[float, Height] = Array()     # Totally fine
          int_array_2d: Array[int, Height, Width] = Array()  # Yup, fine too

     However, note that at most one type variable tuple may appear in a
     single list of type arguments or type parameters:

          x: tuple[*Ts, *Ts]            # Not valid
          class Array[*Shape, *Shape]:  # Not valid
              pass

     Finally, an unpacked type variable tuple can be used as the type
     annotation of ‘*args’:

          def call_soon[*Ts](
              callback: Callable[[*Ts], None],
              *args: *Ts
          ) -> None:
              ...
              callback(*args)

     In contrast to non-unpacked annotations of ‘*args’ - e.g.  ‘*args:
     int’, which would specify that 'all' arguments are ‘int’ - ‘*args:
     *Ts’ enables reference to the types of the 'individual' arguments
     in ‘*args’.  Here, this allows us to ensure the types of the
     ‘*args’ passed to ‘call_soon’ match the types of the (positional)
     arguments of ‘callback’.

     See PEP 646(4) for more details on type variable tuples.

      -- Attributo: __name__

          The name of the type variable tuple.

      -- Attributo: __default__

          The default value of the type variable tuple, or *note
          typing.NoDefault: 569. if it has no default.

          Added in version 3.13.

      -- Metodo: evaluate_default ()

          An *note evaluate function: 44d6. corresponding to the *note
          __default__: 44de. attribute.  When called directly, this
          method supports only the *note VALUE: 15e. format, which is
          equivalent to accessing the *note __default__: 44de. attribute
          directly, but the method object can be passed to *note
          annotationlib.call_evaluate_function(): 44d7. to evaluate the
          value in a different format.

          Added in version 3.14.

      -- Metodo: has_default ()

          Return whether or not the type variable tuple has a default
          value.  This is equivalent to checking whether *note
          __default__: 44de. is not the *note typing.NoDefault: 569.
          singleton, except that it does not force evaluation of the
          *note lazily evaluated: 686. default value.

          Added in version 3.13.

     Added in version 3.11.

     Cambiato nella versione 3.12: Type variable tuples can now be
     declared using the *note type parameter: 5ad. syntax introduced by
     PEP 695(5).

     Cambiato nella versione 3.13: Support for default values was added.

 -- Classe: typing.ParamSpec (name, *, bound=None, covariant=False,
          contravariant=False, default=typing.NoDefault)

     Parameter specification variable.  A specialized version of *note
     type variables: 44c5.

     In *note type parameter lists: 5ad, parameter specifications can be
     declared with two asterisks (‘**’):

          type IntFunc[**P] = Callable[P, int]

     For compatibility with Python 3.11 and earlier, ‘ParamSpec’ objects
     can also be created as follows:

          P = ParamSpec('P')

     Parameter specification variables exist primarily for the benefit
     of static type checkers.  They are used to forward the parameter
     types of one callable to another callable – a pattern commonly
     found in higher order functions and decorators.  They are only
     valid when used in ‘Concatenate’, or as the first argument to
     ‘Callable’, or as parameters for user-defined Generics.  See *note
     Generic: 179e. for more information on generic types.

     For example, to add basic logging to a function, one can create a
     decorator ‘add_logging’ to log function calls.  The parameter
     specification variable tells the type checker that the callable
     passed into the decorator and the new callable returned by it have
     inter-dependent type parameters:

          from collections.abc import Callable
          import logging

          def add_logging[T, **P](f: Callable[P, T]) -> Callable[P, T]:
              '''A type-safe decorator to add logging to a function.'''
              def inner(*args: P.args, **kwargs: P.kwargs) -> T:
                  logging.info(f'{f.__name__} was called')
                  return f(*args, **kwargs)
              return inner

          @add_logging
          def add_two(x: float, y: float) -> float:
              '''Add two numbers together.'''
              return x + y

     Without ‘ParamSpec’, the simplest way to annotate this previously
     was to use a *note TypeVar: 487. with upper bound ‘Callable[...,
     Any]’.  However this causes two problems:

       1. The type checker can’t type check the ‘inner’ function because
          ‘*args’ and ‘**kwargs’ have to be typed *note Any: 8bc.

       2. *note cast(): 44e1. may be required in the body of the
          ‘add_logging’ decorator when returning the ‘inner’ function,
          or the static type checker must be told to ignore the ‘return
          inner’.

      -- Attributo: args

      -- Attributo: kwargs

          Since ‘ParamSpec’ captures both positional and keyword
          parameters, ‘P.args’ and ‘P.kwargs’ can be used to split a
          ‘ParamSpec’ into its components.  ‘P.args’ represents the
          tuple of positional parameters in a given call and should only
          be used to annotate ‘*args’.  ‘P.kwargs’ represents the
          mapping of keyword parameters to their values in a given call,
          and should be only be used to annotate ‘**kwargs’.  Both
          attributes require the annotated parameter to be in scope.  At
          runtime, ‘P.args’ and ‘P.kwargs’ are instances respectively of
          *note ParamSpecArgs: 9cb. and *note ParamSpecKwargs: 9cc.

      -- Attributo: __name__

          The name of the parameter specification.

      -- Attributo: __default__

          The default value of the parameter specification, or *note
          typing.NoDefault: 569. if it has no default.

          Added in version 3.13.

      -- Metodo: evaluate_default ()

          An *note evaluate function: 44d6. corresponding to the *note
          __default__: 44e5. attribute.  When called directly, this
          method supports only the *note VALUE: 15e. format, which is
          equivalent to accessing the *note __default__: 44e5. attribute
          directly, but the method object can be passed to *note
          annotationlib.call_evaluate_function(): 44d7. to evaluate the
          value in a different format.

          Added in version 3.14.

      -- Metodo: has_default ()

          Return whether or not the parameter specification has a
          default value.  This is equivalent to checking whether *note
          __default__: 44e5. is not the *note typing.NoDefault: 569.
          singleton, except that it does not force evaluation of the
          *note lazily evaluated: 686. default value.

          Added in version 3.13.

     Parameter specification variables created with ‘covariant=True’ or
     ‘contravariant=True’ can be used to declare covariant or
     contravariant generic types.  The ‘bound’ argument is also
     accepted, similar to *note TypeVar: 487.  However the actual
     semantics of these keywords are yet to be decided.

     Added in version 3.10.

     Cambiato nella versione 3.12: Parameter specifications can now be
     declared using the *note type parameter: 5ad. syntax introduced by
     PEP 695(6).

     Cambiato nella versione 3.13: Support for default values was added.

          Nota: Only parameter specification variables defined in global
          scope can be pickled.

     Vedi anche
     ..........

        * PEP 612(7) – Parameter Specification Variables (the PEP which
          introduced ‘ParamSpec’ and ‘Concatenate’)

        * *note Concatenate: 9c9.

        * *note Annotating callable objects: 26b2.

 -- Dati: typing.ParamSpecArgs
 -- Dati: typing.ParamSpecKwargs

     Arguments and keyword arguments attributes of a *note ParamSpec:
     488.  The ‘P.args’ attribute of a ‘ParamSpec’ is an instance of
     ‘ParamSpecArgs’, and ‘P.kwargs’ is an instance of
     ‘ParamSpecKwargs’.  They are intended for runtime introspection and
     have no special meaning to static type checkers.

     Calling *note get_origin(): 2ab. on either of these objects will
     return the original ‘ParamSpec’:

          >>> from typing import ParamSpec, get_origin
          >>> P = ParamSpec("P")
          >>> get_origin(P.args) is P
          True
          >>> get_origin(P.kwargs) is P
          True

     Added in version 3.10.

 -- Classe: typing.TypeAliasType (name, value, *, type_params=())

     The type of type aliases created through the *note type: 66d.
     statement.

     Example:

          >>> type Alias = int
          >>> type(Alias)
          <class 'typing.TypeAliasType'>

     Added in version 3.12.

      -- Attributo: __name__

          The name of the type alias:

               >>> type Alias = int
               >>> Alias.__name__
               'Alias'

      -- Attributo: __module__

          The name of the module in which the type alias was defined:

               >>> type Alias = int
               >>> Alias.__module__
               '__main__'

      -- Attributo: __type_params__

          The type parameters of the type alias, or an empty tuple if
          the alias is not generic:

               >>> type ListOrSet[T] = list[T] | set[T]
               >>> ListOrSet.__type_params__
               (T,)
               >>> type NotGeneric = int
               >>> NotGeneric.__type_params__
               ()

      -- Attributo: __value__

          The type alias’s value.  This is *note lazily evaluated: 686,
          so names used in the definition of the alias are not resolved
          until the ‘__value__’ attribute is accessed:

               >>> type Mutually = Recursive
               >>> type Recursive = Mutually
               >>> Mutually
               Mutually
               >>> Recursive
               Recursive
               >>> Mutually.__value__
               Recursive
               >>> Recursive.__value__
               Mutually

      -- Metodo: evaluate_value ()

          An *note evaluate function: 44d6. corresponding to the *note
          __value__: 44eb. attribute.  When called directly, this method
          supports only the *note VALUE: 15e. format, which is
          equivalent to accessing the *note __value__: 44eb. attribute
          directly, but the method object can be passed to *note
          annotationlib.call_evaluate_function(): 44d7. to evaluate the
          value in a different format:

               >>> type Alias = undefined
               >>> Alias.__value__
               Traceback (most recent call last):
               ...
               NameError: name 'undefined' is not defined
               >>> from annotationlib import Format, call_evaluate_function
               >>> Alias.evaluate_value(Format.VALUE)
               Traceback (most recent call last):
               ...
               NameError: name 'undefined' is not defined
               >>> call_evaluate_function(Alias.evaluate_value, Format.FORWARDREF)
               ForwardRef('undefined')

          Added in version 3.14.

     Unpacking
     .........

     Type aliases support star unpacking using the ‘*Alias’ syntax.
     This is equivalent to using ‘Unpack[Alias]’ directly:

          >>> type Alias = tuple[int, str]
          >>> type Unpacked = tuple[bool, *Alias]
          >>> Unpacked.__value__
          tuple[bool, typing.Unpack[Alias]]

     Added in version 3.14.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0695/

   (3) https://peps.python.org/pep-0695/

   (4) https://peps.python.org/pep-0646/

   (5) https://peps.python.org/pep-0695/

   (6) https://peps.python.org/pep-0695/

   (7) https://peps.python.org/pep-0612/


File: python.info,  Node: Other special directives,  Prev: Building generic types and type aliases,  Up: Special typing primitives

5.26.1.17 Other special directives
..................................

These functions and classes should not be used directly as annotations.
Their intended purpose is to be building blocks for creating and
declaring types.

 -- Classe: typing.NamedTuple

     Typed version of *note collections.namedtuple(): 4e1.

     Usage:

          class Employee(NamedTuple):
              name: str
              id: int

     This is equivalent to:

          Employee = collections.namedtuple('Employee', ['name', 'id'])

     To give a field a default value, you can assign to it in the class
     body:

          class Employee(NamedTuple):
              name: str
              id: int = 3

          employee = Employee('Guido')
          assert employee.id == 3

     Fields with a default value must come after any fields without a
     default.

     The resulting class has an extra attribute ‘__annotations__’ giving
     a dict that maps the field names to the field types.  (The field
     names are in the ‘_fields’ attribute and the default values are in
     the ‘_field_defaults’ attribute, both of which are part of the
     *note namedtuple(): 4e1. API.)

     ‘NamedTuple’ subclasses can also have docstrings and methods:

          class Employee(NamedTuple):
              """Represents an employee."""
              name: str
              id: int = 3

              def __repr__(self) -> str:
                  return f'<Employee {self.name}, id={self.id}>'

     ‘NamedTuple’ subclasses can be generic:

          class Group[T](NamedTuple):
              key: T
              group: list[T]

     Backward-compatible usage:

          # For creating a generic NamedTuple on Python 3.11
          T = TypeVar("T")

          class Group(NamedTuple, Generic[T]):
              key: T
              group: list[T]

          # A functional syntax is also supported
          Employee = NamedTuple('Employee', [('name', str), ('id', int)])

     Cambiato nella versione 3.6: Added support for PEP 526(1) variable
     annotation syntax.

     Cambiato nella versione 3.6.1: Added support for default values,
     methods, and docstrings.

     Cambiato nella versione 3.8: The ‘_field_types’ and
     ‘__annotations__’ attributes are now regular dictionaries instead
     of instances of ‘OrderedDict’.

     Cambiato nella versione 3.9: Removed the ‘_field_types’ attribute
     in favor of the more standard ‘__annotations__’ attribute which has
     the same information.

     Cambiato nella versione 3.9: ‘NamedTuple’ is now a function rather
     than a class.  It can still be used as a class base, as described
     above.

     Cambiato nella versione 3.11: Added support for generic
     namedtuples.

     Cambiato nella versione 3.14: Using *note super(): 1a6. (and the
     ‘__class__’ *note closure variable: 187b.) in methods of
     ‘NamedTuple’ subclasses is unsupported and causes a *note
     TypeError: 198.

     Deprecated since version 3.13, will be removed in version 3.15: The
     undocumented keyword argument syntax for creating NamedTuple
     classes (‘NT = NamedTuple("NT", x=int)’) is deprecated, and will be
     disallowed in 3.15.  Use the class-based syntax or the functional
     syntax instead.

     Deprecated since version 3.13, will be removed in version 3.15:
     When using the functional syntax to create a NamedTuple class,
     failing to pass a value to the “fields” parameter (‘NT =
     NamedTuple("NT")’) is deprecated.  Passing ‘None’ to the “fields”
     parameter (‘NT = NamedTuple("NT", None)’) is also deprecated.  Both
     will be disallowed in Python 3.15.  To create a NamedTuple class
     with 0 fields, use ‘class NT(NamedTuple): pass’ or ‘NT =
     NamedTuple("NT", [])’.

 -- Classe: typing.NewType (name, tp)

     Helper class to create low-overhead *note distinct types: 44ba.

     A ‘NewType’ is considered a distinct type by a typechecker.  At
     runtime, however, calling a ‘NewType’ returns its argument
     unchanged.

     Usage:

          UserId = NewType('UserId', int)  # Declare the NewType "UserId"
          first_user = UserId(1)  # "UserId" returns the argument unchanged at runtime

      -- Attributo: __module__

          The name of the module in which the new type is defined.

      -- Attributo: __name__

          The name of the new type.

      -- Attributo: __supertype__

          The type that the new type is based on.

     Added in version 3.5.2.

     Cambiato nella versione 3.10: ‘NewType’ is now a class rather than
     a function.

 -- Classe: typing.Protocol (Generic)

     Base class for protocol classes.

     Protocol classes are defined like this:

          class Proto(Protocol):
              def meth(self) -> int:
                  ...

     Such classes are primarily used with static type checkers that
     recognize structural subtyping (static duck-typing), for example:

          class C:
              def meth(self) -> int:
                  return 0

          def func(x: Proto) -> int:
              return x.meth()

          func(C())  # Passes static type check

     See PEP 544(2) for more details.  Protocol classes decorated with
     *note runtime_checkable(): 675. (described later) act as
     simple-minded runtime protocols that check only the presence of
     given attributes, ignoring their type signatures.  Protocol classes
     without this decorator cannot be used as the second argument to
     *note isinstance(): 2ad. or *note issubclass(): 9c6.

     Protocol classes can be generic, for example:

          class GenProto[T](Protocol):
              def meth(self) -> T:
                  ...

     In code that needs to be compatible with Python 3.11 or older,
     generic Protocols can be written as follows:

          T = TypeVar("T")

          class GenProto(Protocol[T]):
              def meth(self) -> T:
                  ...

     Added in version 3.8.

 -- Funzione: @typing.runtime_checkable

     Mark a protocol class as a runtime protocol.

     Such a protocol can be used with *note isinstance(): 2ad. and *note
     issubclass(): 9c6.  This allows a simple-minded structural check,
     very similar to «one trick ponies» in *note collections.abc: 1f.
     such as *note Iterable: 2691.  For example:

          @runtime_checkable
          class Closable(Protocol):
              def close(self): ...

          assert isinstance(open('/some/file'), Closable)

          @runtime_checkable
          class Named(Protocol):
              name: str

          import threading
          assert isinstance(threading.Thread(name='Bob'), Named)

     This decorator raises *note TypeError: 198. when applied to a
     non-protocol class.

          Nota: ‘runtime_checkable()’ will check only the presence of
          the required methods or attributes, not their type signatures
          or types.  For example, *note ssl.SSLObject: d7c. is a class,
          therefore it passes an *note issubclass(): 9c6. check against
          *note Callable: 26b2.  However, the ‘ssl.SSLObject.__init__’
          method exists only to raise a *note TypeError: 198. with a
          more informative message, therefore making it impossible to
          call (instantiate) *note ssl.SSLObject: d7c.

          Nota: An *note isinstance(): 2ad. check against a
          runtime-checkable protocol can be surprisingly slow compared
          to an ‘isinstance()’ check against a non-protocol class.
          Consider using alternative idioms such as *note hasattr():
          6fa. calls for structural checks in performance-sensitive
          code.

     Added in version 3.8.

     Cambiato nella versione 3.12: The internal implementation of *note
     isinstance(): 2ad. checks against runtime-checkable protocols now
     uses *note inspect.getattr_static(): 6bd. to look up attributes
     (previously, *note hasattr(): 6fa. was used).  As a result, some
     objects which used to be considered instances of a
     runtime-checkable protocol may no longer be considered instances of
     that protocol on Python 3.12+, and vice versa.  Most users are
     unlikely to be affected by this change.

     Cambiato nella versione 3.12: The members of a runtime-checkable
     protocol are now considered «frozen» at runtime as soon as the
     class has been created.  Monkey-patching attributes onto a
     runtime-checkable protocol will still work, but will have no impact
     on *note isinstance(): 2ad. checks comparing objects to the
     protocol.  See *note What’s new in Python 3.12: 6f9. for more
     details.

 -- Classe: typing.TypedDict (dict)

     Special construct to add type hints to a dictionary.  At runtime
     «‘TypedDict’ instances» are simply *note dicts: 183.

     ‘TypedDict’ declares a dictionary type that expects all of its
     instances to have a certain set of keys, where each key is
     associated with a value of a consistent type.  This expectation is
     not checked at runtime but is only enforced by type checkers.
     Usage:

          class Point2D(TypedDict):
              x: int
              y: int
              label: str

          a: Point2D = {'x': 1, 'y': 2, 'label': 'good'}  # OK
          b: Point2D = {'z': 3, 'label': 'bad'}           # Fails type check

          assert Point2D(x=1, y=2, label='first') == dict(x=1, y=2, label='first')

     An alternative way to create a ‘TypedDict’ is by using
     function-call syntax.  The second argument must be a literal *note
     dict: 183.:

          Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': str})

     This functional syntax allows defining keys which are not valid
     *note identifiers: 2289, for example because they are keywords or
     contain hyphens, or when key names must not be *note mangled: 208d.
     like regular private names:

          # raises SyntaxError
          class Point2D(TypedDict):
              in: int  # 'in' is a keyword
              x-y: int  # name with hyphens

          class Definition(TypedDict):
              __schema: str  # mangled to `_Definition__schema`

          # OK, functional syntax
          Point2D = TypedDict('Point2D', {'in': int, 'x-y': int})
          Definition = TypedDict('Definition', {'__schema': str})  # not mangled

     By default, all keys must be present in a ‘TypedDict’.  It is
     possible to mark individual keys as non-required using *note
     NotRequired: 7e2.:

          class Point2D(TypedDict):
              x: int
              y: int
              label: NotRequired[str]

          # Alternative syntax
          Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': NotRequired[str]})

     This means that a ‘Point2D’ ‘TypedDict’ can have the ‘label’ key
     omitted.

     It is also possible to mark all keys as non-required by default by
     specifying a totality of ‘False’:

          class Point2D(TypedDict, total=False):
              x: int
              y: int

          # Alternative syntax
          Point2D = TypedDict('Point2D', {'x': int, 'y': int}, total=False)

     This means that a ‘Point2D’ ‘TypedDict’ can have any of the keys
     omitted.  A type checker is only expected to support a literal
     ‘False’ or ‘True’ as the value of the ‘total’ argument.  ‘True’ is
     the default, and makes all items defined in the class body
     required.

     Individual keys of a ‘total=False’ ‘TypedDict’ can be marked as
     required using *note Required: 7e1.:

          class Point2D(TypedDict, total=False):
              x: Required[int]
              y: Required[int]
              label: str

          # Alternative syntax
          Point2D = TypedDict('Point2D', {
              'x': Required[int],
              'y': Required[int],
              'label': str
          }, total=False)

     It is possible for a ‘TypedDict’ type to inherit from one or more
     other ‘TypedDict’ types using the class-based syntax.  Usage:

          class Point3D(Point2D):
              z: int

     ‘Point3D’ has three items: ‘x’, ‘y’ and ‘z’.  It is equivalent to
     this definition:

          class Point3D(TypedDict):
              x: int
              y: int
              z: int

     A ‘TypedDict’ cannot inherit from a non-‘TypedDict’ class, except
     for *note Generic: 179e.  For example:

          class X(TypedDict):
              x: int

          class Y(TypedDict):
              y: int

          class Z(object): pass  # A non-TypedDict class

          class XY(X, Y): pass  # OK

          class XZ(X, Z): pass  # raises TypeError

     A ‘TypedDict’ can be generic:

          class Group[T](TypedDict):
              key: T
              group: list[T]

     To create a generic ‘TypedDict’ that is compatible with Python 3.11
     or lower, inherit from *note Generic: 179e. explicitly:

          T = TypeVar("T")

          class Group(TypedDict, Generic[T]):
              key: T
              group: list[T]

     A ‘TypedDict’ can be introspected via annotations dicts (see *note
     Annotations Best Practices: 9db. for more information on
     annotations best practices), *note __total__: 44f1, *note
     __required_keys__: 44f2, and *note __optional_keys__: 44f3.

      -- Attributo: __total__

          ‘Point2D.__total__’ gives the value of the ‘total’ argument.
          Example:

               >>> from typing import TypedDict
               >>> class Point2D(TypedDict): pass
               >>> Point2D.__total__
               True
               >>> class Point2D(TypedDict, total=False): pass
               >>> Point2D.__total__
               False
               >>> class Point3D(Point2D): pass
               >>> Point3D.__total__
               True

          This attribute reflects 'only' the value of the ‘total’
          argument to the current ‘TypedDict’ class, not whether the
          class is semantically total.  For example, a ‘TypedDict’ with
          ‘__total__’ set to ‘True’ may have keys marked with *note
          NotRequired: 7e2, or it may inherit from another ‘TypedDict’
          with ‘total=False’.  Therefore, it is generally better to use
          *note __required_keys__: 44f2. and *note __optional_keys__:
          44f3. for introspection.

      -- Attributo: __required_keys__

          Added in version 3.9.

      -- Attributo: __optional_keys__

          ‘Point2D.__required_keys__’ and ‘Point2D.__optional_keys__’
          return *note frozenset: 7f3. objects containing required and
          non-required keys, respectively.

          Keys marked with *note Required: 7e1. will always appear in
          ‘__required_keys__’ and keys marked with *note NotRequired:
          7e2. will always appear in ‘__optional_keys__’.

          For backwards compatibility with Python 3.10 and below, it is
          also possible to use inheritance to declare both required and
          non-required keys in the same ‘TypedDict’ .  This is done by
          declaring a ‘TypedDict’ with one value for the ‘total’
          argument and then inheriting from it in another ‘TypedDict’
          with a different value for ‘total’:

               >>> class Point2D(TypedDict, total=False):
               ...     x: int
               ...     y: int
               ...
               >>> class Point3D(Point2D):
               ...     z: int
               ...
               >>> Point3D.__required_keys__ == frozenset({'z'})
               True
               >>> Point3D.__optional_keys__ == frozenset({'x', 'y'})
               True

          Added in version 3.9.

               Nota: If ‘from __future__ import annotations’ is used or
               if annotations are given as strings, annotations are not
               evaluated when the ‘TypedDict’ is defined.  Therefore,
               the runtime introspection that ‘__required_keys__’ and
               ‘__optional_keys__’ rely on may not work properly, and
               the values of the attributes may be incorrect.

     Support for *note ReadOnly: 48b. is reflected in the following
     attributes:

      -- Attributo: __readonly_keys__

          A *note frozenset: 7f3. containing the names of all read-only
          keys.  Keys are read-only if they carry the *note ReadOnly:
          48b. qualifier.

          Added in version 3.13.

      -- Attributo: __mutable_keys__

          A *note frozenset: 7f3. containing the names of all mutable
          keys.  Keys are mutable if they do not carry the *note
          ReadOnly: 48b. qualifier.

          Added in version 3.13.

     See the TypedDict(3) section in the typing documentation for more
     examples and detailed rules.

     Added in version 3.8.

     Cambiato nella versione 3.9: ‘TypedDict’ is now a function rather
     than a class.  It can still be used as a class base, as described
     above.

     Cambiato nella versione 3.11: Added support for marking individual
     keys as *note Required: 7e1. or *note NotRequired: 7e2.  See PEP
     655(4).

     Cambiato nella versione 3.11: Added support for generic
     ‘TypedDict’s.

     Cambiato nella versione 3.13: Removed support for the
     keyword-argument method of creating ‘TypedDict’s.

     Cambiato nella versione 3.13: Support for the *note ReadOnly: 48b.
     qualifier was added.

     Deprecated since version 3.13, will be removed in version 3.15:
     When using the functional syntax to create a TypedDict class,
     failing to pass a value to the “fields” parameter (‘TD =
     TypedDict("TD")’) is deprecated.  Passing ‘None’ to the “fields”
     parameter (‘TD = TypedDict("TD", None)’) is also deprecated.  Both
     will be disallowed in Python 3.15.  To create a TypedDict class
     with 0 fields, use ‘class TD(TypedDict): pass’ or ‘TD =
     TypedDict("TD", {})’.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0526/

   (2) https://peps.python.org/pep-0544/

   (3) https://typing.python.org/en/latest/spec/typeddict.html#typeddict

   (4) https://peps.python.org/pep-0655/


File: python.info,  Node: Protocols<4>,  Next: ABCs and Protocols for working with I/O,  Prev: Special typing primitives,  Up: Module contents<3>

5.26.1.18 Protocols
...................

The following protocols are provided by the ‘typing’ module.  All are
decorated with *note @runtime_checkable: 675.

 -- Classe: typing.SupportsAbs

     An ABC with one abstract method ‘__abs__’ that is covariant in its
     return type.

 -- Classe: typing.SupportsBytes

     An ABC with one abstract method ‘__bytes__’.

 -- Classe: typing.SupportsComplex

     An ABC with one abstract method ‘__complex__’.

 -- Classe: typing.SupportsFloat

     An ABC with one abstract method ‘__float__’.

 -- Classe: typing.SupportsIndex

     An ABC with one abstract method ‘__index__’.

     Added in version 3.8.

 -- Classe: typing.SupportsInt

     An ABC with one abstract method ‘__int__’.

 -- Classe: typing.SupportsRound

     An ABC with one abstract method ‘__round__’ that is covariant in
     its return type.


File: python.info,  Node: ABCs and Protocols for working with I/O,  Next: Functions and decorators,  Prev: Protocols<4>,  Up: Module contents<3>

5.26.1.19 ABCs and Protocols for working with I/O
.................................................

 -- Classe: typing.IO [AnyStr]
 -- Classe: typing.TextIO
 -- Classe: typing.BinaryIO

     Generic class ‘IO[AnyStr]’ and its subclasses ‘TextIO(IO[str])’ and
     ‘BinaryIO(IO[bytes])’ represent the types of I/O streams such as
     returned by *note open(): 316.  Please note that these classes are
     not protocols, and their interface is fairly broad.

The protocols *note io.Reader: 236. and *note io.Writer: 237. offer a
simpler alternative for argument types, when only the ‘read()’ or
‘write()’ methods are accessed, respectively:

     def read_and_write(reader: Reader[str], writer: Writer[bytes]):
         data = reader.read()
         writer.write(data.encode())

Also consider using *note collections.abc.Iterable: 2691. for iterating
over the lines of an input stream:

     def read_config(stream: Iterable[str]):
         for line in stream:
             ...


File: python.info,  Node: Functions and decorators,  Next: Introspection helpers,  Prev: ABCs and Protocols for working with I/O,  Up: Module contents<3>

5.26.1.20 Functions and decorators
..................................

 -- Funzione: typing.cast (typ, val)

     Cast a value to a type.

     This returns the value unchanged.  To the type checker this signals
     that the return value has the designated type, but at runtime we
     intentionally don’t check anything (we want this to be as fast as
     possible).

 -- Funzione: typing.assert_type (val, typ, /)

     Ask a static type checker to confirm that 'val' has an inferred
     type of 'typ'.

     At runtime this does nothing: it returns the first argument
     unchanged with no checks or side effects, no matter the actual type
     of the argument.

     When a static type checker encounters a call to ‘assert_type()’, it
     emits an error if the value is not of the specified type:

          def greet(name: str) -> None:
              assert_type(name, str)  # OK, inferred type of `name` is `str`
              assert_type(name, int)  # type checker error

     This function is useful for ensuring the type checker’s
     understanding of a script is in line with the developer’s
     intentions:

          def complex_function(arg: object):
              # Do some complex type-narrowing logic,
              # after which we hope the inferred type will be `int`
              ...
              # Test whether the type checker correctly understands our function
              assert_type(arg, int)

     Added in version 3.11.

 -- Funzione: typing.assert_never (arg, /)

     Ask a static type checker to confirm that a line of code is
     unreachable.

     Example:

          def int_or_str(arg: int | str) -> None:
              match arg:
                  case int():
                      print("It's an int")
                  case str():
                      print("It's a str")
                  case _ as unreachable:
                      assert_never(unreachable)

     Here, the annotations allow the type checker to infer that the last
     case can never execute, because ‘arg’ is either an *note int: 19b.
     or a *note str: 169, and both options are covered by earlier cases.

     If a type checker finds that a call to ‘assert_never()’ is
     reachable, it will emit an error.  For example, if the type
     annotation for ‘arg’ was instead ‘int | str | float’, the type
     checker would emit an error pointing out that ‘unreachable’ is of
     type *note float: 196.  For a call to ‘assert_never’ to pass type
     checking, the inferred type of the argument passed in must be the
     bottom type, *note Never: 8b8, and nothing else.

     At runtime, this throws an exception when called.

     Vedi anche
     ..........

     Unreachable Code and Exhaustiveness Checking(1) has more
     information about exhaustiveness checking with static typing.

     Added in version 3.11.

 -- Funzione: typing.reveal_type (obj, /)

     Ask a static type checker to reveal the inferred type of an
     expression.

     When a static type checker encounters a call to this function, it
     emits a diagnostic with the inferred type of the argument.  For
     example:

          x: int = 1
          reveal_type(x)  # Revealed type is "builtins.int"

     This can be useful when you want to debug how your type checker
     handles a particular piece of code.

     At runtime, this function prints the runtime type of its argument
     to *note sys.stderr: b35. and returns the argument unchanged
     (allowing the call to be used within an expression):

          x = reveal_type(1)  # prints "Runtime type is int"
          print(x)  # prints "1"

     Note that the runtime type may be different from (more or less
     specific than) the type statically inferred by a type checker.

     Most type checkers support ‘reveal_type()’ anywhere, even if the
     name is not imported from ‘typing’.  Importing the name from
     ‘typing’, however, allows your code to run without runtime errors
     and communicates intent more clearly.

     Added in version 3.11.

 -- Funzione: @typing.dataclass_transform (*, eq_default=True,
          order_default=False, kw_only_default=False,
          frozen_default=False, field_specifiers=(), **kwargs)

     Decorator to mark an object as providing *note dataclass: 4e2.-like
     behavior.

     ‘dataclass_transform’ may be used to decorate a class, metaclass,
     or a function that is itself a decorator.  The presence of
     ‘@dataclass_transform()’ tells a static type checker that the
     decorated object performs runtime «magic» that transforms a class
     in a similar way to *note @dataclasses.dataclass: 4e2.

     Example usage with a decorator function:

          @dataclass_transform()
          def create_model[T](cls: type[T]) -> type[T]:
              ...
              return cls

          @create_model
          class CustomerModel:
              id: int
              name: str

     On a base class:

          @dataclass_transform()
          class ModelBase: ...

          class CustomerModel(ModelBase):
              id: int
              name: str

     On a metaclass:

          @dataclass_transform()
          class ModelMeta(type): ...

          class ModelBase(metaclass=ModelMeta): ...

          class CustomerModel(ModelBase):
              id: int
              name: str

     The ‘CustomerModel’ classes defined above will be treated by type
     checkers similarly to classes created with *note
     @dataclasses.dataclass: 4e2.  For example, type checkers will
     assume these classes have ‘__init__’ methods that accept ‘id’ and
     ‘name’.

     The decorated class, metaclass, or function may accept the
     following bool arguments which type checkers will assume have the
     same effect as they would have on the *note @dataclasses.dataclass:
     4e2. decorator: ‘init’, ‘eq’, ‘order’, ‘unsafe_hash’, ‘frozen’,
     ‘match_args’, ‘kw_only’, and ‘slots’.  It must be possible for the
     value of these arguments (‘True’ or ‘False’) to be statically
     evaluated.

     The arguments to the ‘dataclass_transform’ decorator can be used to
     customize the default behaviors of the decorated class, metaclass,
     or function:


     Parametri:

        * ‘eq_default’ (*note bool: 3c3.) – Indicates whether the ‘eq’
          parameter is assumed to be ‘True’ or ‘False’ if it is omitted
          by the caller.  Defaults to ‘True’.

        * ‘order_default’ (*note bool: 3c3.) – Indicates whether the
          ‘order’ parameter is assumed to be ‘True’ or ‘False’ if it is
          omitted by the caller.  Defaults to ‘False’.

        * ‘kw_only_default’ (*note bool: 3c3.) – Indicates whether the
          ‘kw_only’ parameter is assumed to be ‘True’ or ‘False’ if it
          is omitted by the caller.  Defaults to ‘False’.

        * ‘frozen_default’ (*note bool: 3c3.) – Indicates whether the
          ‘frozen’ parameter is assumed to be ‘True’ or ‘False’ if it is
          omitted by the caller.  Defaults to ‘False’.

          Added in version 3.12.

        * ‘field_specifiers’ (*note tuple: 614.‘[’*note Callable:
          9ed.‘[’‘...’‘, ’‘Any’‘]’‘, ’‘...’‘]’) – Specifies a static
          list of supported classes or functions that describe fields,
          similar to *note dataclasses.field(): 1942.  Defaults to ‘()’.

        * ‘**kwargs’ (‘Any’) – Arbitrary other keyword arguments are
          accepted in order to allow for possible future extensions.

     Type checkers recognize the following optional parameters on field
     specifiers: 'Recognised parameters for field specifiers'

     Parameter name           Description
                              
     --------------------------------------------------------------------------------------------------------------
                              
     ‘init’                   Indicates whether the field should be included in the synthesized ‘__init__’
                              method.  If unspecified, ‘init’ defaults to ‘True’.
                              
                              
     ‘default’                Provides the default value for the field.
                              
                              
     ‘default_factory’        Provides a runtime callback that returns the default value for the field.  If
                              neither ‘default’ nor ‘default_factory’ are specified, the field is assumed to
                              have no default value and must be provided a value when the class is instantiated.
                              
                              
     ‘factory’                An alias for the ‘default_factory’ parameter on field specifiers.
                              
                              
     ‘kw_only’                Indicates whether the field should be marked as keyword-only.  If ‘True’, the
                              field will be keyword-only.  If ‘False’, it will not be keyword-only.  If
                              unspecified, the value of the ‘kw_only’ parameter on the object decorated with
                              ‘dataclass_transform’ will be used, or if that is unspecified, the value of
                              ‘kw_only_default’ on ‘dataclass_transform’ will be used.
                              
                              
     ‘alias’                  Provides an alternative name for the field.  This alternative name is used in the
                              synthesized ‘__init__’ method.
                              

     At runtime, this decorator records its arguments in the
     ‘__dataclass_transform__’ attribute on the decorated object.  It
     has no other runtime effect.

     See PEP 681(2) for more details.

     Added in version 3.11.

 -- Funzione: @typing.overload

     Decorator for creating overloaded functions and methods.

     The ‘@overload’ decorator allows describing functions and methods
     that support multiple different combinations of argument types.  A
     series of ‘@overload’-decorated definitions must be followed by
     exactly one non-‘@overload’-decorated definition (for the same
     function/method).

     ‘@overload’-decorated definitions are for the benefit of the type
     checker only, since they will be overwritten by the
     non-‘@overload’-decorated definition.  The
     non-‘@overload’-decorated definition, meanwhile, will be used at
     runtime but should be ignored by a type checker.  At runtime,
     calling an ‘@overload’-decorated function directly will raise *note
     NotImplementedError: 36b.

     An example of overload that gives a more precise type than can be
     expressed using a union or a type variable:

          @overload
          def process(response: None) -> None:
              ...
          @overload
          def process(response: int) -> tuple[int, str]:
              ...
          @overload
          def process(response: bytes) -> str:
              ...
          def process(response):
              ...  # actual implementation goes here

     See PEP 484(3) for more details and comparison with other typing
     semantics.

     Cambiato nella versione 3.11: Overloaded functions can now be
     introspected at runtime using *note get_overloads(): 8be.

 -- Funzione: typing.get_overloads (func)

     Return a sequence of *note @overload: 44fc.-decorated definitions
     for 'func'.

     'func' is the function object for the implementation of the
     overloaded function.  For example, given the definition of
     ‘process’ in the documentation for *note @overload: 44fc,
     ‘get_overloads(process)’ will return a sequence of three function
     objects for the three defined overloads.  If called on a function
     with no overloads, ‘get_overloads()’ returns an empty sequence.

     ‘get_overloads()’ can be used for introspecting an overloaded
     function at runtime.

     Added in version 3.11.

 -- Funzione: typing.clear_overloads ()

     Clear all registered overloads in the internal registry.

     This can be used to reclaim the memory used by the registry.

     Added in version 3.11.

 -- Funzione: @typing.final

     Decorator to indicate final methods and final classes.

     Decorating a method with ‘@final’ indicates to a type checker that
     the method cannot be overridden in a subclass.  Decorating a class
     with ‘@final’ indicates that it cannot be subclassed.

     For example:

          class Base:
              @final
              def done(self) -> None:
                  ...
          class Sub(Base):
              def done(self) -> None:  # Error reported by type checker
                  ...

          @final
          class Leaf:
              ...
          class Other(Leaf):  # Error reported by type checker
              ...

     There is no runtime checking of these properties.  See PEP 591(4)
     for more details.

     Added in version 3.8.

     Cambiato nella versione 3.11: The decorator will now attempt to set
     a ‘__final__’ attribute to ‘True’ on the decorated object.  Thus, a
     check like ‘if getattr(obj, "__final__", False)’ can be used at
     runtime to determine whether an object ‘obj’ has been marked as
     final.  If the decorated object does not support setting
     attributes, the decorator returns the object unchanged without
     raising an exception.

 -- Funzione: @typing.no_type_check

     Decorator to indicate that annotations are not type hints.

     This works as a class or function *note decorator: 93b.  With a
     class, it applies recursively to all methods and classes defined in
     that class (but not to methods defined in its superclasses or
     subclasses).  Type checkers will ignore all annotations in a
     function or class with this decorator.

     ‘@no_type_check’ mutates the decorated object in place.

 -- Funzione: @typing.no_type_check_decorator

     Decorator to give another decorator the *note no_type_check(): 8c4.
     effect.

     This wraps the decorator with something that wraps the decorated
     function in *note no_type_check(): 8c4.

     Deprecated since version 3.13, will be removed in version 3.15: No
     type checker ever added support for ‘@no_type_check_decorator’.  It
     is therefore deprecated, and will be removed in Python 3.15.

 -- Funzione: @typing.override

     Decorator to indicate that a method in a subclass is intended to
     override a method or attribute in a superclass.

     Type checkers should emit an error if a method decorated with
     ‘@override’ does not, in fact, override anything.  This helps
     prevent bugs that may occur when a base class is changed without an
     equivalent change to a child class.

     For example:

          class Base:
              def log_status(self) -> None:
                  ...

          class Sub(Base):
              @override
              def log_status(self) -> None:  # Okay: overrides Base.log_status
                  ...

              @override
              def done(self) -> None:  # Error reported by type checker
                  ...

     There is no runtime checking of this property.

     The decorator will attempt to set an ‘__override__’ attribute to
     ‘True’ on the decorated object.  Thus, a check like ‘if
     getattr(obj, "__override__", False)’ can be used at runtime to
     determine whether an object ‘obj’ has been marked as an override.
     If the decorated object does not support setting attributes, the
     decorator returns the object unchanged without raising an
     exception.

     See PEP 698(5) for more details.

     Added in version 3.12.

 -- Funzione: @typing.type_check_only

     Decorator to mark a class or function as unavailable at runtime.

     This decorator is itself not available at runtime.  It is mainly
     intended to mark classes that are defined in type stub files if an
     implementation returns an instance of a private class:

          @type_check_only
          class Response:  # private or not available at runtime
              code: int
              def get_header(self, name: str) -> str: ...

          def fetch_response() -> Response: ...

     Note that returning instances of private classes is not
     recommended.  It is usually preferable to make such classes public.

   ---------- Footnotes ----------

   (1) https://typing.python.org/en/latest/guides/unreachable.html

   (2) https://peps.python.org/pep-0681/

   (3) https://peps.python.org/pep-0484/

   (4) https://peps.python.org/pep-0591/

   (5) https://peps.python.org/pep-0698/


File: python.info,  Node: Introspection helpers,  Next: Constant,  Prev: Functions and decorators,  Up: Module contents<3>

5.26.1.21 Introspection helpers
...............................

 -- Funzione: typing.get_type_hints (obj, globalns=None, localns=None,
          include_extras=False)

     Return a dictionary containing type hints for a function, method,
     module or class object.

     This is often the same as ‘obj.__annotations__’, but this function
     makes the following changes to the annotations dictionary:

        * Forward references encoded as string literals or *note
          ForwardRef: 1bc2. objects are handled by evaluating them in
          'globalns', 'localns', and (where applicable) 'obj'’s *note
          type parameter: 5ad. namespace.  If 'globalns' or 'localns' is
          not given, appropriate namespace dictionaries are inferred
          from 'obj'.

        * ‘None’ is replaced with *note types.NoneType: a54.

        * If *note @no_type_check: 8c4. has been applied to 'obj', an
          empty dictionary is returned.

        * If 'obj' is a class ‘C’, the function returns a dictionary
          that merges annotations from ‘C’’s base classes with those on
          ‘C’ directly.  This is done by traversing *note C.__mro__:
          235e. and iteratively combining ‘__annotations__’
          dictionaries.  Annotations on classes appearing earlier in the
          *note method resolution order: 25bd. always take precedence
          over annotations on classes appearing later in the method
          resolution order.

        * The function recursively replaces all occurrences of
          ‘Annotated[T, ...]’, ‘Required[T]’, ‘NotRequired[T]’, and
          ‘ReadOnly[T]’ with ‘T’, unless 'include_extras' is set to
          ‘True’ (see *note Annotated: b39. for more information).

     See also *note annotationlib.get_annotations(): 459, a lower-level
     function that returns annotations more directly.

          Attenzione: This function may execute arbitrary code contained
          in annotations.  See *note Security implications of
          introspecting annotations: 44ff. for more information.

          Nota: If any forward references in the annotations of 'obj'
          are not resolvable or are not valid Python code, this function
          will raise an exception such as *note NameError: 452.  For
          example, this can happen with imported *note type aliases:
          684. that include forward references, or with names imported
          under *note if TYPE_CHECKING: ef2.

     Cambiato nella versione 3.9: Added ‘include_extras’ parameter as
     part of PEP 593(1).  See the documentation on *note Annotated: b39.
     for more information.

     Cambiato nella versione 3.11: Previously, ‘Optional[t]’ was added
     for function and method annotations if a default value equal to
     ‘None’ was set.  Now the annotation is returned unchanged.

 -- Funzione: typing.get_origin (tp)

     Get the unsubscripted version of a type: for a typing object of the
     form ‘X[Y, Z, ...]’ return ‘X’.

     If ‘X’ is a typing-module alias for a builtin or *note collections:
     1e. class, it will be normalized to the original class.  If ‘X’ is
     an instance of *note ParamSpecArgs: 9cb. or *note ParamSpecKwargs:
     9cc, return the underlying *note ParamSpec: 488.  Return ‘None’ for
     unsupported objects.

     Examples:

          assert get_origin(str) is None
          assert get_origin(Dict[str, int]) is dict
          assert get_origin(Union[int, str]) is Union
          assert get_origin(Annotated[str, "metadata"]) is Annotated
          P = ParamSpec('P')
          assert get_origin(P.args) is P
          assert get_origin(P.kwargs) is P

     Added in version 3.8.

 -- Funzione: typing.get_args (tp)

     Get type arguments with all substitutions performed: for a typing
     object of the form ‘X[Y, Z, ...]’ return ‘(Y, Z, ...)’.

     If ‘X’ is a union or *note Literal: a57. contained in another
     generic type, the order of ‘(Y, Z, ...)’ may be different from the
     order of the original arguments ‘[Y, Z, ...]’ due to type caching.
     Return ‘()’ for unsupported objects.

     Examples:

          assert get_args(int) == ()
          assert get_args(Dict[int, str]) == (int, str)
          assert get_args(Union[int, str]) == (int, str)

     Added in version 3.8.

 -- Funzione: typing.get_protocol_members (tp)

     Return the set of members defined in a *note Protocol: 56b.

          >>> from typing import Protocol, get_protocol_members
          >>> class P(Protocol):
          ...     def a(self) -> str: ...
          ...     b: int
          >>> get_protocol_members(P) == frozenset({'a', 'b'})
          True

     Raise *note TypeError: 198. for arguments that are not Protocols.

     Added in version 3.13.

 -- Funzione: typing.is_protocol (tp)

     Determine if a type is a *note Protocol: 56b.

     For example:

          class P(Protocol):
              def a(self) -> str: ...
              b: int

          is_protocol(P)    # => True
          is_protocol(int)  # => False

     Added in version 3.13.

 -- Funzione: typing.is_typeddict (tp)

     Check if a type is a *note TypedDict: 332.

     For example:

          class Film(TypedDict):
              title: str
              year: int

          assert is_typeddict(Film)
          assert not is_typeddict(list | str)

          # TypedDict is a factory for creating typed dicts,
          # not a typed dict itself
          assert not is_typeddict(TypedDict)

     Added in version 3.10.

 -- Classe: typing.ForwardRef

     Class used for internal typing representation of string forward
     references.

     For example, ‘List["SomeClass"]’ is implicitly transformed into
     ‘List[ForwardRef("SomeClass")]’.  ‘ForwardRef’ should not be
     instantiated by a user, but may be used by introspection tools.

          Nota: PEP 585(2) generic types such as ‘list["SomeClass"]’
          will not be implicitly transformed into
          ‘list[ForwardRef("SomeClass")]’ and thus will not
          automatically resolve to ‘list[SomeClass]’.

     Added in version 3.7.4.

     Cambiato nella versione 3.14: This is now an alias for *note
     annotationlib.ForwardRef: 175d.  Several undocumented behaviors of
     this class have been changed; for example, after a ‘ForwardRef’ has
     been evaluated, the evaluated value is no longer cached.

 -- Funzione: typing.evaluate_forward_ref (forward_ref, *, owner=None,
          globals=None, locals=None, type_params=None,
          format=annotationlib.Format.VALUE)

     Evaluate an *note annotationlib.ForwardRef: 175d. as a *note type
     hint: 23b1.

     This is similar to calling *note
     annotationlib.ForwardRef.evaluate(): 179a, but unlike that method,
     ‘evaluate_forward_ref()’ also recursively evaluates forward
     references nested within the type hint.

     See the documentation for *note
     annotationlib.ForwardRef.evaluate(): 179a. for the meaning of the
     'owner', 'globals', 'locals', 'type_params', and 'format'
     parameters.

          Attenzione: This function may execute arbitrary code contained
          in annotations.  See *note Security implications of
          introspecting annotations: 44ff. for more information.

     Added in version 3.14.

 -- Dati: typing.NoDefault

     A sentinel object used to indicate that a type parameter has no
     default value.  For example:

          >>> T = TypeVar("T")
          >>> T.__default__ is typing.NoDefault
          True
          >>> S = TypeVar("S", default=None)
          >>> S.__default__ is None
          True

     Added in version 3.13.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0593/

   (2) https://peps.python.org/pep-0585/


File: python.info,  Node: Constant,  Next: Deprecated aliases,  Prev: Introspection helpers,  Up: Module contents<3>

5.26.1.22 Constant
..................

 -- Dati: typing.TYPE_CHECKING

     A special constant that is assumed to be ‘True’ by 3rd party static
     type checkers.  It’s ‘False’ at runtime.

     A module which is expensive to import, and which only contain types
     used for typing annotations, can be safely imported inside an ‘if
     TYPE_CHECKING:’ block.  This prevents the module from actually
     being imported at runtime; annotations aren’t eagerly evaluated
     (see PEP 649(1)) so using undefined symbols in annotations is
     harmless–as long as you don’t later examine them.  Your static type
     analysis tool will set ‘TYPE_CHECKING’ to ‘True’ during static type
     analysis, which means the module will be imported and the types
     will be checked properly during such analysis.

     Usage:

          if TYPE_CHECKING:
              import expensive_mod

          def fun(arg: expensive_mod.SomeType) -> None:
              local_var: expensive_mod.AnotherType = other_fun()

     If you occasionally need to examine type annotations at runtime
     which may contain undefined symbols, use *note
     annotationlib.get_annotations(): 459. with a ‘format’ parameter of
     *note annotationlib.Format.STRING: 160. or *note
     annotationlib.Format.FORWARDREF: 15f. to safely retrieve the
     annotations without raising *note NameError: 452.

     Added in version 3.5.2.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0649/


File: python.info,  Node: Deprecated aliases,  Prev: Constant,  Up: Module contents<3>

5.26.1.23 Deprecated aliases
............................

This module defines several deprecated aliases to pre-existing standard
library classes.  These were originally included in the ‘typing’ module
in order to support parameterizing these generic classes using ‘[]’.
However, the aliases became redundant in Python 3.9 when the
corresponding pre-existing classes were enhanced to support ‘[]’ (see
PEP 585(1)).

The redundant types are deprecated as of Python 3.9.  However, while the
aliases may be removed at some point, removal of these aliases is not
currently planned.  As such, no deprecation warnings are currently
issued by the interpreter for these aliases.

If at some point it is decided to remove these deprecated aliases, a
deprecation warning will be issued by the interpreter for at least two
releases prior to removal.  The aliases are guaranteed to remain in the
‘typing’ module without deprecation warnings until at least Python 3.14.

Type checkers are encouraged to flag uses of the deprecated types if the
program they are checking targets a minimum Python version of 3.9 or
newer.

* Menu:

* Aliases to built-in types::
* Aliases to types in collections::
* Aliases to other concrete types::
* Aliases to container ABCs in collections.abc: Aliases to container ABCs in collections abc.
* Aliases to asynchronous ABCs in collections.abc: Aliases to asynchronous ABCs in collections abc.
* Aliases to other ABCs in collections.abc: Aliases to other ABCs in collections abc.
* Aliases to contextlib ABCs::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0585/


File: python.info,  Node: Aliases to built-in types,  Next: Aliases to types in collections,  Up: Deprecated aliases

5.26.1.24 Aliases to built-in types
...................................

 -- Classe: typing.Dict (dict, MutableMapping[KT, VT])

     Deprecated alias to *note dict: 183.

     Note that to annotate arguments, it is preferred to use an abstract
     collection type such as *note Mapping: ac9. rather than to use
     *note dict: 183. or ‘typing.Dict’.

     Deprecato dalla versione 3.9: *note builtins.dict: 183. now
     supports subscripting (‘[]’).  See PEP 585(1) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.List (list, MutableSequence[T])

     Deprecated alias to *note list: 24d.

     Note that to annotate arguments, it is preferred to use an abstract
     collection type such as *note Sequence: 13cc. or *note Iterable:
     2691. rather than to use *note list: 24d. or ‘typing.List’.

     Deprecato dalla versione 3.9: *note builtins.list: 24d. now
     supports subscripting (‘[]’).  See PEP 585(2) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.Set (set, MutableSet[T])

     Deprecated alias to *note builtins.set: 184.

     Note that to annotate arguments, it is preferred to use an abstract
     collection type such as *note collections.abc.Set: 2689. rather
     than to use *note set: 184. or *note typing.Set: 4508.

     Deprecato dalla versione 3.9: *note builtins.set: 184. now supports
     subscripting (‘[]’).  See PEP 585(3) and *note Tipo Generic Alias:
     8c2.

 -- Classe: typing.FrozenSet (frozenset, AbstractSet[T_co])

     Deprecated alias to *note builtins.frozenset: 7f3.

     Deprecato dalla versione 3.9: *note builtins.frozenset: 7f3. now
     supports subscripting (‘[]’).  See PEP 585(4) and *note Tipo
     Generic Alias: 8c2.

 -- Dati: typing.Tuple

     Deprecated alias for *note tuple: 614.

     *note tuple: 614. and ‘Tuple’ are special-cased in the type system;
     see *note Annotating tuples: 26b3. for more details.

     Deprecato dalla versione 3.9: *note builtins.tuple: 614. now
     supports subscripting (‘[]’).  See PEP 585(5) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.Type (Generic[CT_co])

     Deprecated alias to *note type: f46.

     See *note The type of class objects: 44c1. for details on using
     *note type: f46. or ‘typing.Type’ in type annotations.

     Added in version 3.5.2.

     Deprecato dalla versione 3.9: *note builtins.type: f46. now
     supports subscripting (‘[]’).  See PEP 585(6) and *note Tipo
     Generic Alias: 8c2.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0585/

   (2) https://peps.python.org/pep-0585/

   (3) https://peps.python.org/pep-0585/

   (4) https://peps.python.org/pep-0585/

   (5) https://peps.python.org/pep-0585/

   (6) https://peps.python.org/pep-0585/


File: python.info,  Node: Aliases to types in collections,  Next: Aliases to other concrete types,  Prev: Aliases to built-in types,  Up: Deprecated aliases

5.26.1.25 Aliases to types in ‘collections’
...........................................

 -- Classe: typing.DefaultDict (collections.defaultdict,
          MutableMapping[KT, VT])

     Deprecated alias to *note collections.defaultdict: 13c4.

     Added in version 3.5.2.

     Deprecato dalla versione 3.9: *note collections.defaultdict: 13c4.
     now supports subscripting (‘[]’).  See PEP 585(1) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.OrderedDict (collections.OrderedDict,
          MutableMapping[KT, VT])

     Deprecated alias to *note collections.OrderedDict: 7f4.

     Added in version 3.7.2.

     Deprecato dalla versione 3.9: *note collections.OrderedDict: 7f4.
     now supports subscripting (‘[]’).  See PEP 585(2) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.ChainMap (collections.ChainMap, MutableMapping[KT,
          VT])

     Deprecated alias to *note collections.ChainMap: e18.

     Added in version 3.6.1.

     Deprecato dalla versione 3.9: *note collections.ChainMap: e18. now
     supports subscripting (‘[]’).  See PEP 585(3) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.Counter (collections.Counter, Dict[T, int])

     Deprecated alias to *note collections.Counter: 1299.

     Added in version 3.6.1.

     Deprecato dalla versione 3.9: *note collections.Counter: 1299. now
     supports subscripting (‘[]’).  See PEP 585(4) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.Deque (deque, MutableSequence[T])

     Deprecated alias to *note collections.deque: 7f5.

     Added in version 3.6.1.

     Deprecato dalla versione 3.9: *note collections.deque: 7f5. now
     supports subscripting (‘[]’).  See PEP 585(5) and *note Tipo
     Generic Alias: 8c2.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0585/

   (2) https://peps.python.org/pep-0585/

   (3) https://peps.python.org/pep-0585/

   (4) https://peps.python.org/pep-0585/

   (5) https://peps.python.org/pep-0585/


File: python.info,  Node: Aliases to other concrete types,  Next: Aliases to container ABCs in collections abc,  Prev: Aliases to types in collections,  Up: Deprecated aliases

5.26.1.26 Aliases to other concrete types
.........................................

 -- Classe: typing.Pattern
 -- Classe: typing.Match

     Deprecated aliases corresponding to the return types from *note
     re.compile(): dd0. and *note re.match(): 1435.

     These types (and the corresponding functions) are generic over
     *note AnyStr: 5ac.  ‘Pattern’ can be specialised as ‘Pattern[str]’
     or ‘Pattern[bytes]’; ‘Match’ can be specialised as ‘Match[str]’ or
     ‘Match[bytes]’.

     Deprecato dalla versione 3.9: Classes ‘Pattern’ and ‘Match’ from
     *note re: be. now support ‘[]’.  See PEP 585(1) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.Text

     Deprecated alias for *note str: 169.

     ‘Text’ is provided to supply a forward compatible path for Python 2
     code: in Python 2, ‘Text’ is an alias for ‘unicode’.

     Use ‘Text’ to indicate that a value must contain a unicode string
     in a manner that is compatible with both Python 2 and Python 3:

          def add_unicode_checkmark(text: Text) -> Text:
              return text + u' \u2713'

     Added in version 3.5.2.

     Deprecato dalla versione 3.11: Python 2 is no longer supported, and
     most type checkers also no longer support type checking Python 2
     code.  Removal of the alias is not currently planned, but users are
     encouraged to use *note str: 169. instead of ‘Text’.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0585/


File: python.info,  Node: Aliases to container ABCs in collections abc,  Next: Aliases to asynchronous ABCs in collections abc,  Prev: Aliases to other concrete types,  Up: Deprecated aliases

5.26.1.27 Aliases to container ABCs in ‘collections.abc’
........................................................

 -- Classe: typing.AbstractSet (Collection[T_co])

     Deprecated alias to *note collections.abc.Set: 2689.

     Deprecato dalla versione 3.9: *note collections.abc.Set: 2689. now
     supports subscripting (‘[]’).  See PEP 585(1) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.ByteString (Sequence[int])

     Deprecated alias to *note collections.abc.ByteString: 342.

     Use ‘isinstance(obj, collections.abc.Buffer)’ to test if ‘obj’
     implements the *note buffer protocol: 260. at runtime.  For use in
     type annotations, either use *note Buffer: 343. or a union that
     explicitly specifies the types your code supports (e.g., ‘bytes |
     bytearray | memoryview’).

     ‘ByteString’ was originally intended to be an abstract class that
     would serve as a supertype of both *note bytes: 192. and *note
     bytearray: 344.  However, since the ABC never had any methods,
     knowing that an object was an instance of ‘ByteString’ never
     actually told you anything useful about the object.  Other common
     buffer types such as *note memoryview: 165. were also never
     understood as subtypes of ‘ByteString’ (either at runtime or by
     static type checkers).

     See PEP 688(2) for more details.

     Deprecated since version 3.9, will be removed in version 3.17.

 -- Classe: typing.Collection (Sized, Iterable[T_co], Container[T_co])

     Deprecated alias to *note collections.abc.Collection: e86.

     Added in version 3.6.

     Deprecato dalla versione 3.9: *note collections.abc.Collection:
     e86. now supports subscripting (‘[]’).  See PEP 585(3) and *note
     Tipo Generic Alias: 8c2.

 -- Classe: typing.Container (Generic[T_co])

     Deprecated alias to *note collections.abc.Container: 2693.

     Deprecato dalla versione 3.9: *note collections.abc.Container:
     2693. now supports subscripting (‘[]’).  See PEP 585(4) and *note
     Tipo Generic Alias: 8c2.

 -- Classe: typing.ItemsView (MappingView, AbstractSet[tuple[KT_co,
          VT_co]])

     Deprecated alias to *note collections.abc.ItemsView: 2697.

     Deprecato dalla versione 3.9: *note collections.abc.ItemsView:
     2697. now supports subscripting (‘[]’).  See PEP 585(5) and *note
     Tipo Generic Alias: 8c2.

 -- Classe: typing.KeysView (MappingView, AbstractSet[KT_co])

     Deprecated alias to *note collections.abc.KeysView: 2696.

     Deprecato dalla versione 3.9: *note collections.abc.KeysView: 2696.
     now supports subscripting (‘[]’).  See PEP 585(6) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.Mapping (Collection[KT], Generic[KT, VT_co])

     Deprecated alias to *note collections.abc.Mapping: ac9.

     Deprecato dalla versione 3.9: *note collections.abc.Mapping: ac9.
     now supports subscripting (‘[]’).  See PEP 585(7) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.MappingView (Sized)

     Deprecated alias to *note collections.abc.MappingView: 2695.

     Deprecato dalla versione 3.9: *note collections.abc.MappingView:
     2695. now supports subscripting (‘[]’).  See PEP 585(8) and *note
     Tipo Generic Alias: 8c2.

 -- Classe: typing.MutableMapping (Mapping[KT, VT])

     Deprecated alias to *note collections.abc.MutableMapping: 12b4.

     Deprecato dalla versione 3.9: *note collections.abc.MutableMapping:
     12b4. now supports subscripting (‘[]’).  See PEP 585(9) and *note
     Tipo Generic Alias: 8c2.

 -- Classe: typing.MutableSequence (Sequence[T])

     Deprecated alias to *note collections.abc.MutableSequence: 4c0.

     Deprecato dalla versione 3.9: *note
     collections.abc.MutableSequence: 4c0. now supports subscripting
     (‘[]’).  See PEP 585(10) and *note Tipo Generic Alias: 8c2.

 -- Classe: typing.MutableSet (AbstractSet[T])

     Deprecated alias to *note collections.abc.MutableSet: 2694.

     Deprecato dalla versione 3.9: *note collections.abc.MutableSet:
     2694. now supports subscripting (‘[]’).  See PEP 585(11) and *note
     Tipo Generic Alias: 8c2.

 -- Classe: typing.Sequence (Reversible[T_co], Collection[T_co])

     Deprecated alias to *note collections.abc.Sequence: 13cc.

     Deprecato dalla versione 3.9: *note collections.abc.Sequence: 13cc.
     now supports subscripting (‘[]’).  See PEP 585(12) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.ValuesView (MappingView, Collection[_VT_co])

     Deprecated alias to *note collections.abc.ValuesView: 2698.

     Deprecato dalla versione 3.9: *note collections.abc.ValuesView:
     2698. now supports subscripting (‘[]’).  See PEP 585(13) and *note
     Tipo Generic Alias: 8c2.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0585/

   (2) https://peps.python.org/pep-0688/#current-options

   (3) https://peps.python.org/pep-0585/

   (4) https://peps.python.org/pep-0585/

   (5) https://peps.python.org/pep-0585/

   (6) https://peps.python.org/pep-0585/

   (7) https://peps.python.org/pep-0585/

   (8) https://peps.python.org/pep-0585/

   (9) https://peps.python.org/pep-0585/

   (10) https://peps.python.org/pep-0585/

   (11) https://peps.python.org/pep-0585/

   (12) https://peps.python.org/pep-0585/

   (13) https://peps.python.org/pep-0585/


File: python.info,  Node: Aliases to asynchronous ABCs in collections abc,  Next: Aliases to other ABCs in collections abc,  Prev: Aliases to container ABCs in collections abc,  Up: Deprecated aliases

5.26.1.28 Aliases to asynchronous ABCs in ‘collections.abc’
...........................................................

 -- Classe: typing.Coroutine (Awaitable[ReturnType], Generic[YieldType,
          SendType, ReturnType])

     Deprecated alias to *note collections.abc.Coroutine: fdf.

     See *note Annotating generators and coroutines: 2980. for details
     on using *note collections.abc.Coroutine: fdf. and
     ‘typing.Coroutine’ in type annotations.

     Added in version 3.5.3.

     Deprecato dalla versione 3.9: *note collections.abc.Coroutine: fdf.
     now supports subscripting (‘[]’).  See PEP 585(1) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.AsyncGenerator (AsyncIterator[YieldType],
          Generic[YieldType, SendType])

     Deprecated alias to *note collections.abc.AsyncGenerator: e89.

     See *note Annotating generators and coroutines: 2980. for details
     on using *note collections.abc.AsyncGenerator: e89. and
     ‘typing.AsyncGenerator’ in type annotations.

     Added in version 3.6.1.

     Deprecato dalla versione 3.9: *note collections.abc.AsyncGenerator:
     e89. now supports subscripting (‘[]’).  See PEP 585(2) and *note
     Tipo Generic Alias: 8c2.

     Cambiato nella versione 3.13: The ‘SendType’ parameter now has a
     default.

 -- Classe: typing.AsyncIterable (Generic[T_co])

     Deprecated alias to *note collections.abc.AsyncIterable: fe1.

     Added in version 3.5.2.

     Deprecato dalla versione 3.9: *note collections.abc.AsyncIterable:
     fe1. now supports subscripting (‘[]’).  See PEP 585(3) and *note
     Tipo Generic Alias: 8c2.

 -- Classe: typing.AsyncIterator (AsyncIterable[T_co])

     Deprecated alias to *note collections.abc.AsyncIterator: fe0.

     Added in version 3.5.2.

     Deprecato dalla versione 3.9: *note collections.abc.AsyncIterator:
     fe0. now supports subscripting (‘[]’).  See PEP 585(4) and *note
     Tipo Generic Alias: 8c2.

 -- Classe: typing.Awaitable (Generic[T_co])

     Deprecated alias to *note collections.abc.Awaitable: fde.

     Added in version 3.5.2.

     Deprecato dalla versione 3.9: *note collections.abc.Awaitable: fde.
     now supports subscripting (‘[]’).  See PEP 585(5) and *note Tipo
     Generic Alias: 8c2.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0585/

   (2) https://peps.python.org/pep-0585/

   (3) https://peps.python.org/pep-0585/

   (4) https://peps.python.org/pep-0585/

   (5) https://peps.python.org/pep-0585/


File: python.info,  Node: Aliases to other ABCs in collections abc,  Next: Aliases to contextlib ABCs,  Prev: Aliases to asynchronous ABCs in collections abc,  Up: Deprecated aliases

5.26.1.29 Aliases to other ABCs in ‘collections.abc’
....................................................

 -- Classe: typing.Iterable (Generic[T_co])

     Deprecated alias to *note collections.abc.Iterable: 2691.

     Deprecato dalla versione 3.9: *note collections.abc.Iterable: 2691.
     now supports subscripting (‘[]’).  See PEP 585(1) and *note Tipo
     Generic Alias: 8c2.

 -- Classe: typing.Iterator (Iterable[T_co])

     Deprecated alias to *note collections.abc.Iterator: 2692.

     Deprecato dalla versione 3.9: *note collections.abc.Iterator: 2692.
     now supports subscripting (‘[]’).  See PEP 585(2) and *note Tipo
     Generic Alias: 8c2.

 -- Dati: typing.Callable

     Deprecated alias to *note collections.abc.Callable: 9ed.

     See *note Annotating callable objects: 26b2. for details on how to
     use *note collections.abc.Callable: 9ed. and ‘typing.Callable’ in
     type annotations.

     Deprecato dalla versione 3.9: *note collections.abc.Callable: 9ed.
     now supports subscripting (‘[]’).  See PEP 585(3) and *note Tipo
     Generic Alias: 8c2.

     Cambiato nella versione 3.10: ‘Callable’ now supports *note
     ParamSpec: 488. and *note Concatenate: 9c9.  See PEP 612(4) for
     more details.

 -- Classe: typing.Generator (Iterator[YieldType], Generic[YieldType,
          SendType, ReturnType])

     Deprecated alias to *note collections.abc.Generator: fdd.

     See *note Annotating generators and coroutines: 2980. for details
     on using *note collections.abc.Generator: fdd. and
     ‘typing.Generator’ in type annotations.

     Deprecato dalla versione 3.9: *note collections.abc.Generator: fdd.
     now supports subscripting (‘[]’).  See PEP 585(5) and *note Tipo
     Generic Alias: 8c2.

     Cambiato nella versione 3.13: Default values for the send and
     return types were added.

 -- Classe: typing.Hashable

     Deprecated alias to *note collections.abc.Hashable: 71a.

     Deprecato dalla versione 3.12: Use *note collections.abc.Hashable:
     71a. directly instead.

 -- Classe: typing.Reversible (Iterable[T_co])

     Deprecated alias to *note collections.abc.Reversible: e87.

     Deprecato dalla versione 3.9: *note collections.abc.Reversible:
     e87. now supports subscripting (‘[]’).  See PEP 585(6) and *note
     Tipo Generic Alias: 8c2.

 -- Classe: typing.Sized

     Deprecated alias to *note collections.abc.Sized: 71b.

     Deprecato dalla versione 3.12: Use *note collections.abc.Sized:
     71b. directly instead.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0585/

   (2) https://peps.python.org/pep-0585/

   (3) https://peps.python.org/pep-0585/

   (4) https://peps.python.org/pep-0612/

   (5) https://peps.python.org/pep-0585/

   (6) https://peps.python.org/pep-0585/


File: python.info,  Node: Aliases to contextlib ABCs,  Prev: Aliases to other ABCs in collections abc,  Up: Deprecated aliases

5.26.1.30 Aliases to ‘contextlib’ ABCs
......................................

 -- Classe: typing.ContextManager (Generic[T_co, ExitT_co])

     Deprecated alias to *note contextlib.AbstractContextManager: e8c.

     The first type parameter, ‘T_co’, represents the type returned by
     the *note __enter__(): 7e5. method.  The optional second type
     parameter, ‘ExitT_co’, which defaults to ‘bool | None’, represents
     the type returned by the *note __exit__(): 1508. method.

     Added in version 3.5.4.

     Deprecato dalla versione 3.9: *note
     contextlib.AbstractContextManager: e8c. now supports subscripting
     (‘[]’).  See PEP 585(1) and *note Tipo Generic Alias: 8c2.

     Cambiato nella versione 3.13: Added the optional second type
     parameter, ‘ExitT_co’.

 -- Classe: typing.AsyncContextManager (Generic[T_co, AExitT_co])

     Deprecated alias to *note contextlib.AbstractAsyncContextManager:
     d22.

     The first type parameter, ‘T_co’, represents the type returned by
     the *note __aenter__(): 2401. method.  The optional second type
     parameter, ‘AExitT_co’, which defaults to ‘bool | None’, represents
     the type returned by the *note __aexit__(): 1989. method.

     Added in version 3.6.2.

     Deprecato dalla versione 3.9: *note
     contextlib.AbstractAsyncContextManager: d22. now supports
     subscripting (‘[]’).  See PEP 585(2) and *note Tipo Generic Alias:
     8c2.

     Cambiato nella versione 3.13: Added the optional second type
     parameter, ‘AExitT_co’.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0585/

   (2) https://peps.python.org/pep-0585/


File: python.info,  Node: Deprecation Timeline of Major Features,  Prev: Module contents<3>,  Up: typing — Support for type hints

5.26.1.31 Deprecation Timeline of Major Features
................................................

Certain features in ‘typing’ are deprecated and may be removed in a
future version of Python.  The following table summarizes major
deprecations for your convenience.  This is subject to change, and not
all deprecations are listed.

Feature                       Deprecated in                 Projected removal             PEP/issue
                                                                                          
------------------------------------------------------------------------------------------------------------------------
                                                                                          
‘typing’ versions of          3.9                           Undecided (see                PEP 585(1)
standard collections                                        *note Deprecated aliases: 4502.
                                                            for more information)
                                                            
                                                                                          
*note typing.ByteString: 345. 3.9                           3.17                          gh-91896(2)
                                                                                          
                                                                                          
*note typing.Text: 360.       3.11                          Undecided                     gh-92332(3)
                                                                                          
                                                                                          
*note typing.Hashable: 718.   3.12                          Undecided                     gh-94309(4)
and                                                                                       
*note typing.Sized: 719.

*note typing.TypeAlias: 9ce.  3.12                          Undecided                     PEP 695(5)
                                                                                          
                                                                                          
*note @typing.no_type_check_decorator: 333.3.13             3.15                          gh-106309(6)
                                                                                          
                                                                                          
*note typing.AnyStr: 5ac.     3.13                          3.18                          gh-105578(7)
                                                                                          

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0585/

   (2) https://github.com/python/cpython/issues/91896

   (3) https://github.com/python/cpython/issues/92332

   (4) https://github.com/python/cpython/issues/94309

   (5) https://peps.python.org/pep-0695/

   (6) https://github.com/python/cpython/issues/106309

   (7) https://github.com/python/cpython/issues/105578


File: python.info,  Node: pydoc — Documentation generator and online help system,  Next: Python Development Mode,  Prev: typing — Support for type hints,  Up: Development Tools

5.26.2 ‘pydoc’ — Documentation generator and online help system
---------------------------------------------------------------

'Source code:' Lib/pydoc.py(1)

__________________________________________________________________

The ‘pydoc’ module automatically generates documentation from Python
modules.  The documentation can be presented as pages of text on the
console, served to a web browser, or saved to HTML files.

For modules, classes, functions and methods, the displayed documentation
is derived from the docstring (i.e.  the *note __doc__: b23. attribute)
of the object, and recursively of its documentable members.  If there is
no docstring, ‘pydoc’ tries to obtain a description from the block of
comment lines just above the definition of the class, function or method
in the source file, or at the top of the module (see *note
inspect.getcomments(): 1920.).

The built-in function *note help(): ad6. invokes the online help system
in the interactive interpreter, which uses ‘pydoc’ to generate its
documentation as text on the console.  The same text documentation can
also be viewed from outside the Python interpreter by running ‘pydoc’ as
a script at the operating system’s command prompt.  For example, running

     python -m pydoc sys

at a shell prompt will display documentation on the *note sys: df.
module, in a style similar to the manual pages shown by the Unix ‘man’
command.  The argument to ‘pydoc’ can be the name of a function, module,
or package, or a dotted reference to a class, method, or function within
a module or module in a package.  If the argument to ‘pydoc’ looks like
a path (that is, it contains the path separator for your operating
system, such as a slash in Unix), and refers to an existing Python
source file, then documentation is produced for that file.

     Nota: In order to find objects and their documentation, ‘pydoc’
     imports the module(s) to be documented.  Therefore, any code on
     module level will be executed on that occasion.  Use an ‘if
     __name__ == '__main__':’ guard to only execute code when a file is
     invoked as a script and not just imported.

When printing output to the console, ‘pydoc’ attempts to paginate the
output for easier reading.  If either the ‘MANPAGER’ or the ‘PAGER’
environment variable is set, ‘pydoc’ will use its value as a pagination
program.  When both are set, ‘MANPAGER’ is used.

Specifying a ‘-w’ flag before the argument will cause HTML documentation
to be written out to a file in the current directory, instead of
displaying text on the console.

Specifying a ‘-k’ flag before the argument will search the synopsis
lines of all available modules for the keyword given as the argument,
again in a manner similar to the Unix ‘man’ command.  The synopsis line
of a module is the first line of its documentation string.

You can also use ‘pydoc’ to start an HTTP server on the local machine
that will serve documentation to visiting web browsers.  ‘python -m
pydoc -p 1234’ will start a HTTP server on port 1234, allowing you to
browse the documentation at ‘http://localhost:1234/’ in your preferred
web browser.  Specifying ‘0’ as the port number will select an arbitrary
unused port.

‘python -m pydoc -n <hostname>’ will start the server listening at the
given hostname.  By default the hostname is “localhost” but if you want
the server to be reached from other machines, you may want to change the
host name that the server responds to.  During development this is
especially useful if you want to run pydoc from within a container.

‘python -m pydoc -b’ will start the server and additionally open a web
browser to a module index page.  Each served page has a navigation bar
at the top where you can 'Get' help on an individual item, 'Search' all
modules with a keyword in their synopsis line, and go to the 'Module
index', 'Topics' and 'Keywords' pages.

When ‘pydoc’ generates documentation, it uses the current environment
and path to locate modules.  Thus, invoking ‘pydoc spam’ documents
precisely the version of the module you would get if you started the
Python interpreter and typed ‘import spam’.

Module docs for core modules are assumed to reside in
‘https://docs.python.org/X.Y/library/’ where ‘X’ and ‘Y’ are the major
and minor version numbers of the Python interpreter.  This can be
overridden by setting the ‘PYTHONDOCS’ environment variable to a
different URL or to a local directory containing the Library Reference
Manual pages.

Cambiato nella versione 3.2: Added the ‘-b’ option.

Cambiato nella versione 3.3: The ‘-g’ command line option was removed.

Cambiato nella versione 3.4: ‘pydoc’ now uses *note inspect.signature():
22f. rather than *note inspect.getfullargspec(): 942. to extract
signature information from callables.

Cambiato nella versione 3.7: Added the ‘-n’ option.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/pydoc.py


File: python.info,  Node: Python Development Mode,  Next: doctest — Test interactive Python examples,  Prev: pydoc — Documentation generator and online help system,  Up: Development Tools

5.26.3 Python Development Mode
------------------------------

Added in version 3.7.

The Python Development Mode introduces additional runtime checks that
are too expensive to be enabled by default.  It should not be more
verbose than the default if the code is correct; new warnings are only
emitted when an issue is detected.

It can be enabled using the *note -X dev: 16f. command line option or by
setting the *note PYTHONDEVMODE: ce9. environment variable to ‘1’.

See also *note Python debug build: 50a.

* Menu:

* Effects of the Python Development Mode::
* ResourceWarning Example::
* Bad file descriptor error example::


File: python.info,  Node: Effects of the Python Development Mode,  Next: ResourceWarning Example,  Up: Python Development Mode

5.26.3.1 Effects of the Python Development Mode
...............................................

Enabling the Python Development Mode is similar to the following
command, but with additional effects described below:

     PYTHONMALLOC=debug PYTHONASYNCIODEBUG=1 python -W default -X faulthandler

Effects of the Python Development Mode:

   * Add ‘default’ *note warning filter: 2113.  The following warnings
     are shown:

        * *note DeprecationWarning: 1a3.

        * *note ImportWarning: 71f.

        * *note PendingDeprecationWarning: ac8.

        * *note ResourceWarning: 54d.

     Normally, the above warnings are filtered by the default *note
     warning filters: 2113.

     It behaves as if the *note -W default: ac7. command line option is
     used.

     Use the *note -W error: ac7. command line option or set the *note
     PYTHONWARNINGS: da5. environment variable to ‘error’ to treat
     warnings as errors.

   * Install debug hooks on memory allocators to check for:

        * Buffer underflow

        * Buffer overflow

        * Memory allocator API violation

        * Unsafe usage of the GIL

     See the *note PyMem_SetupDebugHooks(): e66. C function.

     It behaves as if the *note PYTHONMALLOC: e60. environment variable
     is set to ‘debug’.

     To enable the Python Development Mode without installing debug
     hooks on memory allocators, set the *note PYTHONMALLOC: e60.
     environment variable to ‘default’.

   * Call *note faulthandler.enable(): 20f. at Python startup to install
     handlers for the *note SIGSEGV: 1282, *note SIGFPE: 1283, *note
     SIGABRT: 1284, *note SIGBUS: 1285. and *note SIGILL: 1286. signals
     to dump the Python traceback on a crash.

     It behaves as if the *note -X faulthandler: 16f. command line
     option is used or if the *note PYTHONFAULTHANDLER: 1287.
     environment variable is set to ‘1’.

   * Enable *note asyncio debug mode: 2123.  For example, *note asyncio:
     b. checks for coroutines that were not awaited and logs them.

     It behaves as if the *note PYTHONASYNCIODEBUG: 2122. environment
     variable is set to ‘1’.

   * Check the 'encoding' and 'errors' arguments for string encoding and
     decoding operations.  Examples: *note open(): 316, *note
     str.encode(): ad4. and *note bytes.decode(): ad5.

     By default, for best performance, the 'errors' argument is only
     checked at the first encoding/decoding error and the 'encoding'
     argument is sometimes ignored for empty strings.

   * The *note io.IOBase: 506. destructor logs ‘close()’ exceptions.

   * Set the *note dev_mode: 1e6a. attribute of *note sys.flags: 89d. to
     ‘True’.

The Python Development Mode does not enable the *note tracemalloc: 105.
module by default, because the overhead cost (to performance and memory)
would be too large.  Enabling the *note tracemalloc: 105. module
provides additional information on the origin of some errors.  For
example, *note ResourceWarning: 54d. logs the traceback where the
resource was allocated, and a buffer overflow error logs the traceback
where the memory block was allocated.

The Python Development Mode does not prevent the *note -O: 18c. command
line option from removing *note assert: b62. statements nor from setting
*note __debug__: 9dc. to ‘False’.

The Python Development Mode can only be enabled at the Python startup.
Its value can be read from *note sys.flags.dev_mode: 89d.

Cambiato nella versione 3.8: The *note io.IOBase: 506. destructor now
logs ‘close()’ exceptions.

Cambiato nella versione 3.9: The 'encoding' and 'errors' arguments are
now checked for string encoding and decoding operations.


File: python.info,  Node: ResourceWarning Example,  Next: Bad file descriptor error example,  Prev: Effects of the Python Development Mode,  Up: Python Development Mode

5.26.3.2 ResourceWarning Example
................................

Example of a script counting the number of lines of the text file
specified in the command line:

     import sys

     def main():
         fp = open(sys.argv[1])
         nlines = len(fp.readlines())
         print(nlines)
         # The file is closed implicitly

     if __name__ == "__main__":
         main()

The script does not close the file explicitly.  By default, Python does
not emit any warning.  Example using README.txt, which has 269 lines:

     $ python script.py README.txt
     269

Enabling the Python Development Mode displays a *note ResourceWarning:
54d. warning:

     $ python -X dev script.py README.txt
     269
     script.py:10: ResourceWarning: unclosed file <_io.TextIOWrapper name='README.rst' mode='r' encoding='UTF-8'>
       main()
     ResourceWarning: Enable tracemalloc to get the object allocation traceback

In addition, enabling *note tracemalloc: 105. shows the line where the
file was opened:

     $ python -X dev -X tracemalloc=5 script.py README.rst
     269
     script.py:10: ResourceWarning: unclosed file <_io.TextIOWrapper name='README.rst' mode='r' encoding='UTF-8'>
       main()
     Object allocated at (most recent call last):
       File "script.py", lineno 10
         main()
       File "script.py", lineno 4
         fp = open(sys.argv[1])

The fix is to close explicitly the file.  Example using a context
manager:

     def main():
         # Close the file explicitly when exiting the with block
         with open(sys.argv[1]) as fp:
             nlines = len(fp.readlines())
         print(nlines)

Not closing a resource explicitly can leave a resource open for way
longer than expected; it can cause severe issues upon exiting Python.
It is bad in CPython, but it is even worse in PyPy.  Closing resources
explicitly makes an application more deterministic and more reliable.


File: python.info,  Node: Bad file descriptor error example,  Prev: ResourceWarning Example,  Up: Python Development Mode

5.26.3.3 Bad file descriptor error example
..........................................

Script displaying the first line of itself:

     import os

     def main():
         fp = open(__file__)
         firstline = fp.readline()
         print(firstline.rstrip())
         os.close(fp.fileno())
         # The file is closed implicitly

     main()

By default, Python does not emit any warning:

     $ python script.py
     import os

The Python Development Mode shows a *note ResourceWarning: 54d. and logs
a «Bad file descriptor» error when finalizing the file object:

     $ python -X dev script.py
     import os
     script.py:10: ResourceWarning: unclosed file <_io.TextIOWrapper name='script.py' mode='r' encoding='UTF-8'>
       main()
     ResourceWarning: Enable tracemalloc to get the object allocation traceback
     Exception ignored in: <_io.TextIOWrapper name='script.py' mode='r' encoding='UTF-8'>
     Traceback (most recent call last):
       File "script.py", line 10, in <module>
         main()
     OSError: [Errno 9] Bad file descriptor

‘os.close(fp.fileno())’ closes the file descriptor.  When the file
object finalizer tries to close the file descriptor again, it fails with
the ‘Bad file descriptor’ error.  A file descriptor must be closed only
once.  In the worst case scenario, closing it twice can lead to a crash
(see bpo-18748(1) for an example).

The fix is to remove the ‘os.close(fp.fileno())’ line, or open the file
with ‘closefd=False’.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=18748


File: python.info,  Node: doctest — Test interactive Python examples,  Next: unittest — Unit testing framework,  Prev: Python Development Mode,  Up: Development Tools

5.26.4 ‘doctest’ — Test interactive Python examples
---------------------------------------------------

'Source code:' Lib/doctest.py(1)

__________________________________________________________________

The *note doctest: 3e. module searches for pieces of text that look like
interactive Python sessions, and then executes those sessions to verify
that they work exactly as shown.  There are several common ways to use
doctest:

   * To check that a module’s docstrings are up-to-date by verifying
     that all interactive examples still work as documented.

   * To perform regression testing by verifying that interactive
     examples from a test file or a test object work as expected.

   * To write tutorial documentation for a package, liberally
     illustrated with input-output examples.  Depending on whether the
     examples or the expository text are emphasized, this has the flavor
     of «literate testing» or «executable documentation».

Here’s a complete but small example module:

     """
     This is the "example" module.

     The example module supplies one function, factorial().  For example,

     >>> factorial(5)
     120
     """

     def factorial(n):
         """Return the factorial of n, an exact integer >= 0.

         >>> [factorial(n) for n in range(6)]
         [1, 1, 2, 6, 24, 120]
         >>> factorial(30)
         265252859812191058636308480000000
         >>> factorial(-1)
         Traceback (most recent call last):
             ...
         ValueError: n must be >= 0

         Factorials of floats are OK, but the float must be an exact integer:
         >>> factorial(30.1)
         Traceback (most recent call last):
             ...
         ValueError: n must be exact integer
         >>> factorial(30.0)
         265252859812191058636308480000000

         It must also not be ridiculously large:
         >>> factorial(1e100)
         Traceback (most recent call last):
             ...
         OverflowError: n too large
         """

         import math
         if not n >= 0:
             raise ValueError("n must be >= 0")
         if math.floor(n) != n:
             raise ValueError("n must be exact integer")
         if n+1 == n:  # catch a value like 1e300
             raise OverflowError("n too large")
         result = 1
         factor = 2
         while factor <= n:
             result *= factor
             factor += 1
         return result


     if __name__ == "__main__":
         import doctest
         doctest.testmod()

If you run ‘example.py’ directly from the command line, *note doctest:
3e. works its magic:

     $ python example.py
     $

There’s no output!  That’s normal, and it means all the examples worked.
Pass ‘-v’ to the script, and *note doctest: 3e. prints a detailed log of
what it’s trying, and prints a summary at the end:

     $ python example.py -v
     Trying:
         factorial(5)
     Expecting:
         120
     ok
     Trying:
         [factorial(n) for n in range(6)]
     Expecting:
         [1, 1, 2, 6, 24, 120]
     ok

And so on, eventually ending with:

     Trying:
         factorial(1e100)
     Expecting:
         Traceback (most recent call last):
             ...
         OverflowError: n too large
     ok
     2 items passed all tests:
        1 test in __main__
        6 tests in __main__.factorial
     7 tests in 2 items.
     7 passed.
     Test passed.
     $

That’s all you need to know to start making productive use of *note
doctest: 3e.!  Jump in.  The following sections provide full details.
Note that there are many examples of doctests in the standard Python
test suite and libraries.  Especially useful examples can be found in
the standard test file ‘Lib/test/test_doctest/test_doctest.py’.

Added in version 3.13: Output is colorized by default and can be *note
controlled using environment variables: 1b7.

* Menu:

* Simple Usage; Checking Examples in Docstrings: Simple Usage Checking Examples in Docstrings.
* Simple Usage; Checking Examples in a Text File: Simple Usage Checking Examples in a Text File.
* Command-line Usage::
* How It Works::
* Basic API::
* Unittest API::
* Advanced API::
* Debugging::
* Soapbox::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/doctest.py


File: python.info,  Node: Simple Usage Checking Examples in Docstrings,  Next: Simple Usage Checking Examples in a Text File,  Up: doctest — Test interactive Python examples

5.26.4.1 Simple Usage: Checking Examples in Docstrings
......................................................

The simplest way to start using doctest (but not necessarily the way
you’ll continue to do it) is to end each module ‘M’ with:

     if __name__ == "__main__":
         import doctest
         doctest.testmod()

‘doctest’ then examines docstrings in module ‘M’.

Running the module as a script causes the examples in the docstrings to
get executed and verified:

     python M.py

This won’t display anything unless an example fails, in which case the
failing example(s) and the cause(s) of the failure(s) are printed to
stdout, and the final line of output is ‘***Test Failed*** N failures.’,
where 'N' is the number of examples that failed.

Run it with the ‘-v’ switch instead:

     python M.py -v

and a detailed report of all examples tried is printed to standard
output, along with assorted summaries at the end.

You can force verbose mode by passing ‘verbose=True’ to *note testmod():
1674, or prohibit it by passing ‘verbose=False’.  In either of those
cases, *note sys.argv: 146c. is not examined by *note testmod(): 1674.
(so passing ‘-v’ or not has no effect).

There is also a command line shortcut for running *note testmod(): 1674,
see section *note Command-line Usage: 453e.

For more information on *note testmod(): 1674, see section *note Basic
API: 453f.


File: python.info,  Node: Simple Usage Checking Examples in a Text File,  Next: Command-line Usage,  Prev: Simple Usage Checking Examples in Docstrings,  Up: doctest — Test interactive Python examples

5.26.4.2 Simple Usage: Checking Examples in a Text File
.......................................................

Another simple application of doctest is testing interactive examples in
a text file.  This can be done with the *note testfile(): 4542.
function:

     import doctest
     doctest.testfile("example.txt")

That short script executes and verifies any interactive Python examples
contained in the file ‘example.txt’.  The file content is treated as if
it were a single giant docstring; the file doesn’t need to contain a
Python program!  For example, perhaps ‘example.txt’ contains this:

     The ``example`` module
     ======================

     Using ``factorial``
     -------------------

     This is an example text file in reStructuredText format.  First import
     ``factorial`` from the ``example`` module:

         >>> from example import factorial

     Now use it:

         >>> factorial(6)
         120

Running ‘doctest.testfile("example.txt")’ then finds the error in this
documentation:

     File "./example.txt", line 14, in example.txt
     Failed example:
         factorial(6)
     Expected:
         120
     Got:
         720

As with *note testmod(): 1674, *note testfile(): 4542. won’t display
anything unless an example fails.  If an example does fail, then the
failing example(s) and the cause(s) of the failure(s) are printed to
stdout, using the same format as ‘testmod()’.

By default, *note testfile(): 4542. looks for files in the calling
module’s directory.  See section *note Basic API: 453f. for a
description of the optional arguments that can be used to tell it to
look for files in other locations.

Like *note testmod(): 1674, *note testfile(): 4542.”s verbosity can be
set with the ‘-v’ command-line switch or with the optional keyword
argument 'verbose'.

There is also a command line shortcut for running *note testfile():
4542, see section *note Command-line Usage: 453e.

For more information on *note testfile(): 4542, see section *note Basic
API: 453f.


File: python.info,  Node: Command-line Usage,  Next: How It Works,  Prev: Simple Usage Checking Examples in a Text File,  Up: doctest — Test interactive Python examples

5.26.4.3 Command-line Usage
...........................

The *note doctest: 3e. module can be invoked as a script from the
command line:

     python -m doctest [-v] [-o OPTION] [-f] file [file ...]

 -- Option: -v, --verbose

     Detailed report of all examples tried is printed to standard
     output, along with assorted summaries at the end:

          python -m doctest -v example.py

     This will import ‘example.py’ as a standalone module and run *note
     testmod(): 1674. on it.  Note that this may not work correctly if
     the file is part of a package and imports other submodules from
     that package.

     If the file name does not end with ‘.py’, ‘doctest’ infers that it
     must be run with *note testfile(): 4542. instead:

          python -m doctest -v example.txt

 -- Option: -o, --option <option>

     Option flags control various aspects of doctest’s behavior, see
     section *note Option Flags: 1135.

     Added in version 3.4.

 -- Option: -f, --fail-fast

     This is shorthand for ‘-o FAIL_FAST’.

     Added in version 3.4.


File: python.info,  Node: How It Works,  Next: Basic API,  Prev: Command-line Usage,  Up: doctest — Test interactive Python examples

5.26.4.4 How It Works
.....................

This section examines in detail how doctest works: which docstrings it
looks at, how it finds interactive examples, what execution context it
uses, how it handles exceptions, and how option flags can be used to
control its behavior.  This is the information that you need to know to
write doctest examples; for information about actually running doctest
on these examples, see the following sections.

* Menu:

* Which Docstrings Are Examined?::
* How are Docstring Examples Recognized?::
* What’s the Execution Context?::
* What About Exceptions?::
* Option Flags::
* Directives::
* Warnings: Warnings<2>.


File: python.info,  Node: Which Docstrings Are Examined?,  Next: How are Docstring Examples Recognized?,  Up: How It Works

5.26.4.5 Which Docstrings Are Examined?
.......................................

The module docstring, and all function, class and method docstrings are
searched.  Objects imported into the module are not searched.

In addition, there are cases when you want tests to be part of a module
but not part of the help text, which requires that the tests not be
included in the docstring.  Doctest looks for a module-level variable
called ‘__test__’ and uses it to locate other tests.  If ‘M.__test__’
exists, it must be a dict, and each entry maps a (string) name to a
function object, class object, or string.  Function and class object
docstrings found from ‘M.__test__’ are searched, and strings are treated
as if they were docstrings.  In output, a key ‘K’ in ‘M.__test__’
appears with name ‘M.__test__.K’.

For example, place this block of code at the top of ‘example.py’:

     __test__ = {
         'numbers': """
     >>> factorial(6)
     720

     >>> [factorial(n) for n in range(6)]
     [1, 1, 2, 6, 24, 120]
     """
     }

The value of ‘example.__test__["numbers"]’ will be treated as a
docstring and all the tests inside it will be run.  It is important to
note that the value can be mapped to a function, class object, or
module; if so, ‘doctest’ searches them recursively for docstrings, which
are then scanned for tests.

Any classes found are recursively searched similarly, to test docstrings
in their contained methods and nested classes.

     Nota: ‘doctest’ can only automatically discover classes and
     functions that are defined at the module level or inside other
     classes.

     Since nested classes and functions only exist when an outer
     function is called, they cannot be discovered.  Define them outside
     to make them visible.


File: python.info,  Node: How are Docstring Examples Recognized?,  Next: What’s the Execution Context?,  Prev: Which Docstrings Are Examined?,  Up: How It Works

5.26.4.6 How are Docstring Examples Recognized?
...............................................

In most cases a copy-and-paste of an interactive console session works
fine, but doctest isn’t trying to do an exact emulation of any specific
Python shell.

     >>> # comments are ignored
     >>> x = 12
     >>> x
     12
     >>> if x == 13:
     ...     print("yes")
     ... else:
     ...     print("no")
     ...     print("NO")
     ...     print("NO!!!")
     ...
     no
     NO
     NO!!!
     >>>

Any expected output must immediately follow the final ‘'>>> '’ or ‘'...
'’ line containing the code, and the expected output (if any) extends to
the next ‘'>>> '’ or all-whitespace line.

The fine print:

   * Expected output cannot contain an all-whitespace line, since such a
     line is taken to signal the end of expected output.  If expected
     output does contain a blank line, put ‘<BLANKLINE>’ in your doctest
     example each place a blank line is expected.

   * All hard tab characters are expanded to spaces, using 8-column tab
     stops.  Tabs in output generated by the tested code are not
     modified.  Because any hard tabs in the sample output 'are'
     expanded, this means that if the code output includes hard tabs,
     the only way the doctest can pass is if the *note
     NORMALIZE_WHITESPACE: 4551. option or *note directive: 4552. is in
     effect.  Alternatively, the test can be rewritten to capture the
     output and compare it to an expected value as part of the test.
     This handling of tabs in the source was arrived at through trial
     and error, and has proven to be the least error prone way of
     handling them.  It is possible to use a different algorithm for
     handling tabs by writing a custom *note DocTestParser: 4553. class.

   * Output to stdout is captured, but not output to stderr (exception
     tracebacks are captured via a different means).

   * If you continue a line via backslashing in an interactive session,
     or for any other reason use a backslash, you should use a raw
     docstring, which will preserve your backslashes exactly as you type
     them:

          >>> def f(x):
          ...     r'''Backslashes in a raw docstring: m\n'''
          ...
          >>> print(f.__doc__)
          Backslashes in a raw docstring: m\n

     Otherwise, the backslash will be interpreted as part of the string.
     For example, the ‘\n’ above would be interpreted as a newline
     character.  Alternatively, you can double each backslash in the
     doctest version (and not use a raw string):

          >>> def f(x):
          ...     '''Backslashes in a raw docstring: m\\n'''
          ...
          >>> print(f.__doc__)
          Backslashes in a raw docstring: m\n

   * The starting column doesn’t matter:

          >>> assert "Easy!"
                >>> import math
                    >>> math.floor(1.9)
                    1

     and as many leading whitespace characters are stripped from the
     expected output as appeared in the initial ‘'>>> '’ line that
     started the example.


File: python.info,  Node: What’s the Execution Context?,  Next: What About Exceptions?,  Prev: How are Docstring Examples Recognized?,  Up: How It Works

5.26.4.7 What’s the Execution Context?
......................................

By default, each time *note doctest: 3e. finds a docstring to test, it
uses a 'shallow copy' of ‘M’’s globals, so that running tests doesn’t
change the module’s real globals, and so that one test in ‘M’ can’t
leave behind crumbs that accidentally allow another test to work.  This
means examples can freely use any names defined at top-level in ‘M’, and
names defined earlier in the docstring being run.  Examples cannot see
names defined in other docstrings.

You can force use of your own dict as the execution context by passing
‘globs=your_dict’ to *note testmod(): 1674. or *note testfile(): 4542.
instead.


File: python.info,  Node: What About Exceptions?,  Next: Option Flags,  Prev: What’s the Execution Context?,  Up: How It Works

5.26.4.8 What About Exceptions?
...............................

No problem, provided that the traceback is the only output produced by
the example: just paste in the traceback.  (1)  Since tracebacks contain
details that are likely to change rapidly (for example, exact file paths
and line numbers), this is one case where doctest works hard to be
flexible in what it accepts.

Simple example:

     >>> [1, 2, 3].remove(42)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     ValueError: list.remove(x): x not in list

That doctest succeeds if *note ValueError: 2ec. is raised, with the
‘list.remove(x): x not in list’ detail as shown.

The expected output for an exception must start with a traceback header,
which may be either of the following two lines, indented the same as the
first line of the example:

     Traceback (most recent call last):
     Traceback (innermost last):

The traceback header is followed by an optional traceback stack, whose
contents are ignored by doctest.  The traceback stack is typically
omitted, or copied verbatim from an interactive session.

The traceback stack is followed by the most interesting part: the
line(s) containing the exception type and detail.  This is usually the
last line of a traceback, but can extend across multiple lines if the
exception has a multi-line detail:

     >>> raise ValueError('multi\n    line\ndetail')
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     ValueError: multi
         line
     detail

The last three lines (starting with *note ValueError: 2ec.) are compared
against the exception’s type and detail, and the rest are ignored.

Best practice is to omit the traceback stack, unless it adds significant
documentation value to the example.  So the last example is probably
better as:

     >>> raise ValueError('multi\n    line\ndetail')
     Traceback (most recent call last):
         ...
     ValueError: multi
         line
     detail

Note that tracebacks are treated very specially.  In particular, in the
rewritten example, the use of ‘...’ is independent of doctest’s *note
ELLIPSIS: 1675. option.  The ellipsis in that example could be left out,
or could just as well be three (or three hundred) commas or digits, or
an indented transcript of a Monty Python skit.

Some details you should read once, but won’t need to remember:

   * Doctest can’t guess whether your expected output came from an
     exception traceback or from ordinary printing.  So, e.g., an
     example that expects ‘ValueError: 42 is prime’ will pass whether
     *note ValueError: 2ec. is actually raised or if the example merely
     prints that traceback text.  In practice, ordinary output rarely
     begins with a traceback header line, so this doesn’t create real
     problems.

   * Each line of the traceback stack (if present) must be indented
     further than the first line of the example, 'or' start with a
     non-alphanumeric character.  The first line following the traceback
     header indented the same and starting with an alphanumeric is taken
     to be the start of the exception detail.  Of course this does the
     right thing for genuine tracebacks.

   * When the *note IGNORE_EXCEPTION_DETAIL: 1510. doctest option is
     specified, everything following the leftmost colon and any module
     information in the exception name is ignored.

   * The interactive shell omits the traceback header line for some
     *note SyntaxError: 18e.s.  But doctest uses the traceback header
     line to distinguish exceptions from non-exceptions.  So in the rare
     case where you need to test a ‘SyntaxError’ that omits the
     traceback header, you will need to manually add the traceback
     header line to your test example.

   * For some exceptions, Python displays the position of the error
     using ‘^’ markers and tildes:

          >>> 1 + None
            File "<stdin>", line 1
              1 + None
              ~~^~~~~~
          TypeError: unsupported operand type(s) for +: 'int' and 'NoneType'

     Since the lines showing the position of the error come before the
     exception type and detail, they are not checked by doctest.  For
     example, the following test would pass, even though it puts the ‘^’
     marker in the wrong location:

          >>> 1 + None
            File "<stdin>", line 1
              1 + None
              ^~~~~~~~
          TypeError: unsupported operand type(s) for +: 'int' and 'NoneType'

   ---------- Footnotes ----------

   (1) Examples containing both expected output and an exception are not
supported.  Trying to guess where one ends and the other begins is too
error-prone, and that also makes for a confusing test.


File: python.info,  Node: Option Flags,  Next: Directives,  Prev: What About Exceptions?,  Up: How It Works

5.26.4.9 Option Flags
.....................

A number of option flags control various aspects of doctest’s behavior.
Symbolic names for the flags are supplied as module constants, which can
be *note bitwise ORed: 24a9. together and passed to various functions.
The names can also be used in *note doctest directives: 4552, and may be
passed to the doctest command line interface via the ‘-o’ option.

The first group of options define test semantics, controlling aspects of
how doctest decides whether actual output matches an example’s expected
output:

 -- Dati: doctest.DONT_ACCEPT_TRUE_FOR_1

     By default, if an expected output block contains just ‘1’, an
     actual output block containing just ‘1’ or just ‘True’ is
     considered to be a match, and similarly for ‘0’ versus ‘False’.
     When *note DONT_ACCEPT_TRUE_FOR_1: 455a. is specified, neither
     substitution is allowed.  The default behavior caters to that
     Python changed the return type of many functions from integer to
     boolean; doctests expecting «little integer» output still work in
     these cases.  This option will probably go away, but not for
     several years.

 -- Dati: doctest.DONT_ACCEPT_BLANKLINE

     By default, if an expected output block contains a line containing
     only the string ‘<BLANKLINE>’, then that line will match a blank
     line in the actual output.  Because a genuinely blank line delimits
     the expected output, this is the only way to communicate that a
     blank line is expected.  When *note DONT_ACCEPT_BLANKLINE: 455b. is
     specified, this substitution is not allowed.

 -- Dati: doctest.NORMALIZE_WHITESPACE

     When specified, all sequences of whitespace (blanks and newlines)
     are treated as equal.  Any sequence of whitespace within the
     expected output will match any sequence of whitespace within the
     actual output.  By default, whitespace must match exactly.  *note
     NORMALIZE_WHITESPACE: 4551. is especially useful when a line of
     expected output is very long, and you want to wrap it across
     multiple lines in your source.

 -- Dati: doctest.ELLIPSIS

     When specified, an ellipsis marker (‘...’) in the expected output
     can match any substring in the actual output.  This includes
     substrings that span line boundaries, and empty substrings, so it’s
     best to keep usage of this simple.  Complicated uses can lead to
     the same kinds of «oops, it matched too much!» surprises that ‘.*’
     is prone to in regular expressions.

 -- Dati: doctest.IGNORE_EXCEPTION_DETAIL

     When specified, doctests expecting exceptions pass so long as an
     exception of the expected type is raised, even if the details
     (message and fully qualified exception name) don’t match.

     For example, an example expecting ‘ValueError: 42’ will pass if the
     actual exception raised is ‘ValueError: 3*14’, but will fail if,
     say, a *note TypeError: 198. is raised instead.  It will also
     ignore any fully qualified name included before the exception
     class, which can vary between implementations and versions of
     Python and the code/libraries in use.  Hence, all three of these
     variations will work with the flag specified:

          >>> raise Exception('message')
          Traceback (most recent call last):
          Exception: message

          >>> raise Exception('message')
          Traceback (most recent call last):
          builtins.Exception: message

          >>> raise Exception('message')
          Traceback (most recent call last):
          __main__.Exception: message

     Note that *note ELLIPSIS: 1675. can also be used to ignore the
     details of the exception message, but such a test may still fail
     based on whether the module name is present or matches exactly.

     Cambiato nella versione 3.2: *note IGNORE_EXCEPTION_DETAIL: 1510.
     now also ignores any information relating to the module containing
     the exception under test.

 -- Dati: doctest.SKIP

     When specified, do not run the example at all.  This can be useful
     in contexts where doctest examples serve as both documentation and
     test cases, and an example should be included for documentation
     purposes, but should not be checked.  E.g., the example’s output
     might be random; or the example might depend on resources which
     would be unavailable to the test driver.

     The SKIP flag can also be used for temporarily «commenting out»
     examples.

 -- Dati: doctest.COMPARISON_FLAGS

     A bitmask or’ing together all the comparison flags above.

The second group of options controls how test failures are reported:

 -- Dati: doctest.REPORT_UDIFF

     When specified, failures that involve multi-line expected and
     actual outputs are displayed using a unified diff.

 -- Dati: doctest.REPORT_CDIFF

     When specified, failures that involve multi-line expected and
     actual outputs will be displayed using a context diff.

 -- Dati: doctest.REPORT_NDIFF

     When specified, differences are computed by ‘difflib.Differ’, using
     the same algorithm as the popular ‘ndiff.py’ utility.  This is the
     only method that marks differences within lines as well as across
     lines.  For example, if a line of expected output contains digit
     ‘1’ where actual output contains letter ‘l’, a line is inserted
     with a caret marking the mismatching column positions.

 -- Dati: doctest.REPORT_ONLY_FIRST_FAILURE

     When specified, display the first failing example in each doctest,
     but suppress output for all remaining examples.  This will prevent
     doctest from reporting correct examples that break because of
     earlier failures; but it might also hide incorrect examples that
     fail independently of the first failure.  When *note
     REPORT_ONLY_FIRST_FAILURE: 455e. is specified, the remaining
     examples are still run, and still count towards the total number of
     failures reported; only the output is suppressed.

 -- Dati: doctest.FAIL_FAST

     When specified, exit after the first failing example and don’t
     attempt to run the remaining examples.  Thus, the number of
     failures reported will be at most 1.  This flag may be useful
     during debugging, since examples after the first failure won’t even
     produce debugging output.

 -- Dati: doctest.REPORTING_FLAGS

     A bitmask or’ing together all the reporting flags above.

There is also a way to register new option flag names, though this isn’t
useful unless you intend to extend *note doctest: 3e. internals via
subclassing:

 -- Funzione: doctest.register_optionflag (name)

     Create a new option flag with a given name, and return the new
     flag’s integer value.  *note register_optionflag(): 4560. can be
     used when subclassing *note OutputChecker: 4561. or *note
     DocTestRunner: 4562. to create new options that are supported by
     your subclasses.  *note register_optionflag(): 4560. should always
     be called using the following idiom:

          MY_FLAG = register_optionflag('MY_FLAG')


File: python.info,  Node: Directives,  Next: Warnings<2>,  Prev: Option Flags,  Up: How It Works

5.26.4.10 Directives
....................

Doctest directives may be used to modify the *note option flags: 1135.
for an individual example.  Doctest directives are special Python
comments following an example’s source code:

     directive:             "#" "doctest:" *note directive_options: 4565.
     directive_options:     *note directive_option: 4566. ("," *note directive_option: 4566.)*
     directive_option:      *note on_or_off: 4567. *note directive_option_name: 4568.
     on_or_off:             "+" | "-"
     directive_option_name: "DONT_ACCEPT_BLANKLINE" | "NORMALIZE_WHITESPACE" | ...

Whitespace is not allowed between the ‘+’ or ‘-’ and the directive
option name.  The directive option name can be any of the option flag
names explained above.

An example’s doctest directives modify doctest’s behavior for that
single example.  Use ‘+’ to enable the named behavior, or ‘-’ to disable
it.

For example, this test passes:

     >>> print(list(range(20)))  # doctest: +NORMALIZE_WHITESPACE
     [0,   1,  2,  3,  4,  5,  6,  7,  8,  9,
     10,  11, 12, 13, 14, 15, 16, 17, 18, 19]

Without the directive it would fail, both because the actual output
doesn’t have two blanks before the single-digit list elements, and
because the actual output is on a single line.  This test also passes,
and also requires a directive to do so:

     >>> print(list(range(20)))  # doctest: +ELLIPSIS
     [0, 1, ..., 18, 19]

Multiple directives can be used on a single physical line, separated by
commas:

     >>> print(list(range(20)))  # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
     [0,    1, ...,   18,    19]

If multiple directive comments are used for a single example, then they
are combined:

     >>> print(list(range(20)))  # doctest: +ELLIPSIS
     ...                         # doctest: +NORMALIZE_WHITESPACE
     [0,    1, ...,   18,    19]

As the previous example shows, you can add ‘...’ lines to your example
containing only directives.  This can be useful when an example is too
long for a directive to comfortably fit on the same line:

     >>> print(list(range(5)) + list(range(10, 20)) + list(range(30, 40)))
     ... # doctest: +ELLIPSIS
     [0, ..., 4, 10, ..., 19, 30, ..., 39]

Note that since all options are disabled by default, and directives
apply only to the example they appear in, enabling options (via ‘+’ in a
directive) is usually the only meaningful choice.  However, option flags
can also be passed to functions that run doctests, establishing
different defaults.  In such cases, disabling an option via ‘-’ in a
directive can be useful.


File: python.info,  Node: Warnings<2>,  Prev: Directives,  Up: How It Works

5.26.4.11 Warnings
..................

*note doctest: 3e. is serious about requiring exact matches in expected
output.  If even a single character doesn’t match, the test fails.  This
will probably surprise you a few times, as you learn exactly what Python
does and doesn’t guarantee about output.  For example, when printing a
set, Python doesn’t guarantee that the element is printed in any
particular order, so a test like

     >>> foo()
     {"spam", "eggs"}

is vulnerable!  One workaround is to do

     >>> foo() == {"spam", "eggs"}
     True

instead.  Another is to do

     >>> d = sorted(foo())
     >>> d
     ['eggs', 'spam']

There are others, but you get the idea.

Another bad idea is to print things that embed an object address, like

     >>> id(1.0)  # certain to fail some of the time
     7948648
     >>> class C: pass
     >>> C()  # the default repr() for instances embeds an address
     <C object at 0x00AC18F0>

The *note ELLIPSIS: 1675. directive gives a nice approach for the last
example:

     >>> C()  # doctest: +ELLIPSIS
     <C object at 0x...>

Floating-point numbers are also subject to small output variations
across platforms, because Python defers to the platform C library for
some floating-point calculations, and C libraries vary widely in quality
here.

     >>> 1000**0.1  # risky
     1.9952623149688797
     >>> round(1000**0.1, 9) # safer
     1.995262315
     >>> print(f'{1000**0.1:.4f}') # much safer
     1.9953

Numbers of the form ‘I/2.**J’ are safe across all platforms, and I often
contrive doctest examples to produce numbers of that form:

     >>> 3./4  # utterly safe
     0.75

Simple fractions are also easier for people to understand, and that
makes for better documentation.


File: python.info,  Node: Basic API,  Next: Unittest API,  Prev: How It Works,  Up: doctest — Test interactive Python examples

5.26.4.12 Basic API
...................

The functions *note testmod(): 1674. and *note testfile(): 4542. provide
a simple interface to doctest that should be sufficient for most basic
uses.  For a less formal introduction to these two functions, see
sections *note Simple Usage; Checking Examples in Docstrings: 453c. and
*note Simple Usage; Checking Examples in a Text File: 4540.

 -- Funzione: doctest.testfile (filename, module_relative=True,
          name=None, package=None, globs=None, verbose=None,
          report=True, optionflags=0, extraglobs=None,
          raise_on_error=False, parser=DocTestParser(), encoding=None)

     All arguments except 'filename' are optional, and should be
     specified in keyword form.

     Test examples in the file named 'filename'.  Return
     ‘(failure_count, test_count)’.

     Optional argument 'module_relative' specifies how the filename
     should be interpreted:

        * If 'module_relative' is ‘True’ (the default), then 'filename'
          specifies an OS-independent module-relative path.  By default,
          this path is relative to the calling module’s directory; but
          if the 'package' argument is specified, then it is relative to
          that package.  To ensure OS-independence, 'filename' should
          use ‘/’ characters to separate path segments, and may not be
          an absolute path (i.e., it may not begin with ‘/’).

        * If 'module_relative' is ‘False’, then 'filename' specifies an
          OS-specific path.  The path may be absolute or relative;
          relative paths are resolved with respect to the current
          working directory.

     Optional argument 'name' gives the name of the test; by default, or
     if ‘None’, ‘os.path.basename(filename)’ is used.

     Optional argument 'package' is a Python package or the name of a
     Python package whose directory should be used as the base directory
     for a module-relative filename.  If no package is specified, then
     the calling module’s directory is used as the base directory for
     module-relative filenames.  It is an error to specify 'package' if
     'module_relative' is ‘False’.

     Optional argument 'globs' gives a dict to be used as the globals
     when executing examples.  A new shallow copy of this dict is
     created for the doctest, so its examples start with a clean slate.
     By default, or if ‘None’, a new empty dict is used.

     Optional argument 'extraglobs' gives a dict merged into the globals
     used to execute examples.  This works like *note dict.update():
     166c.: if 'globs' and 'extraglobs' have a common key, the
     associated value in 'extraglobs' appears in the combined dict.  By
     default, or if ‘None’, no extra globals are used.  This is an
     advanced feature that allows parameterization of doctests.  For
     example, a doctest can be written for a base class, using a generic
     name for the class, then reused to test any number of subclasses by
     passing an 'extraglobs' dict mapping the generic name to the
     subclass to be tested.

     Optional argument 'verbose' prints lots of stuff if true, and
     prints only failures if false; by default, or if ‘None’, it’s true
     if and only if ‘'-v'’ is in *note sys.argv: 146c.

     Optional argument 'report' prints a summary at the end when true,
     else prints nothing at the end.  In verbose mode, the summary is
     detailed, else the summary is very brief (in fact, empty if all
     tests passed).

     Optional argument 'optionflags' (default value ‘0’) takes the *note
     bitwise OR: 24a9. of option flags.  See section *note Option Flags:
     1135.

     Optional argument 'raise_on_error' defaults to false.  If true, an
     exception is raised upon the first failure or unexpected exception
     in an example.  This allows failures to be post-mortem debugged.
     Default behavior is to continue running examples.

     Optional argument 'parser' specifies a *note DocTestParser: 4553.
     (or subclass) that should be used to extract tests from the files.
     It defaults to a normal parser (i.e., ‘DocTestParser()’).

     Optional argument 'encoding' specifies an encoding that should be
     used to convert the file to unicode.

 -- Funzione: doctest.testmod (m=None, name=None, globs=None,
          verbose=None, report=True, optionflags=0, extraglobs=None,
          raise_on_error=False, exclude_empty=False)

     All arguments are optional, and all except for 'm' should be
     specified in keyword form.

     Test examples in docstrings in functions and classes reachable from
     module 'm' (or module *note __main__: 1. if 'm' is not supplied or
     is ‘None’), starting with ‘m.__doc__’.

     Also test examples reachable from dict ‘m.__test__’, if it exists.
     ‘m.__test__’ maps names (strings) to functions, classes and
     strings; function and class docstrings are searched for examples;
     strings are searched directly, as if they were docstrings.

     Only docstrings attached to objects belonging to module 'm' are
     searched.

     Return ‘(failure_count, test_count)’.

     Optional argument 'name' gives the name of the module; by default,
     or if ‘None’, ‘m.__name__’ is used.

     Optional argument 'exclude_empty' defaults to false.  If true,
     objects for which no doctests are found are excluded from
     consideration.  The default is a backward compatibility hack, so
     that code still using *note doctest.master.summarize: 456c. in
     conjunction with *note testmod(): 1674. continues to get output for
     objects with no tests.  The 'exclude_empty' argument to the newer
     *note DocTestFinder: 1990. constructor defaults to true.

     Optional arguments 'extraglobs', 'verbose', 'report',
     'optionflags', 'raise_on_error', and 'globs' are the same as for
     function *note testfile(): 4542. above, except that 'globs'
     defaults to ‘m.__dict__’.

 -- Funzione: doctest.run_docstring_examples (f, globs, verbose=False,
          name='NoName', compileflags=None, optionflags=0)

     Test examples associated with object 'f'; for example, 'f' may be a
     string, a module, a function, or a class object.

     A shallow copy of dictionary argument 'globs' is used for the
     execution context.

     Optional argument 'name' is used in failure messages, and defaults
     to ‘"NoName"’.

     If optional argument 'verbose' is true, output is generated even if
     there are no failures.  By default, output is generated only in
     case of an example failure.

     Optional argument 'compileflags' gives the set of flags that should
     be used by the Python compiler when running the examples.  By
     default, or if ‘None’, flags are deduced corresponding to the set
     of future features found in 'globs'.

     Optional argument 'optionflags' works as for function *note
     testfile(): 4542. above.


File: python.info,  Node: Unittest API,  Next: Advanced API,  Prev: Basic API,  Up: doctest — Test interactive Python examples

5.26.4.13 Unittest API
......................

As your collection of doctest’ed modules grows, you’ll want a way to run
all their doctests systematically.  *note doctest: 3e. provides two
functions that can be used to create *note unittest: 10c. test suites
from modules and text files containing doctests.  To integrate with
*note unittest: 10c. test discovery, include a *note load_tests: 4570.
function in your test module:

     import unittest
     import doctest
     import my_module_with_doctests

     def load_tests(loader, tests, ignore):
         tests.addTests(doctest.DocTestSuite(my_module_with_doctests))
         return tests

There are two main functions for creating *note unittest.TestSuite: ff7.
instances from text files and modules with doctests:

 -- Funzione: doctest.DocFileSuite (*paths, module_relative=True,
          package=None, setUp=None, tearDown=None, globs=None,
          optionflags=0, parser=DocTestParser(), encoding=None)

     Convert doctest tests from one or more text files to a *note
     unittest.TestSuite: ff7.

     The returned *note unittest.TestSuite: ff7. is to be run by the
     unittest framework and runs the interactive examples in each file.
     If an example in any file fails, then the synthesized unit test
     fails, and a *note failureException: 4572. exception is raised
     showing the name of the file containing the test and a (sometimes
     approximate) line number.  If all the examples in a file are
     skipped, then the synthesized unit test is also marked as skipped.

     Pass one or more paths (as strings) to text files to be examined.

     Options may be provided as keyword arguments:

     Optional argument 'module_relative' specifies how the filenames in
     'paths' should be interpreted:

        * If 'module_relative' is ‘True’ (the default), then each
          filename in 'paths' specifies an OS-independent
          module-relative path.  By default, this path is relative to
          the calling module’s directory; but if the 'package' argument
          is specified, then it is relative to that package.  To ensure
          OS-independence, each filename should use ‘/’ characters to
          separate path segments, and may not be an absolute path (i.e.,
          it may not begin with ‘/’).

        * If 'module_relative' is ‘False’, then each filename in 'paths'
          specifies an OS-specific path.  The path may be absolute or
          relative; relative paths are resolved with respect to the
          current working directory.

     Optional argument 'package' is a Python package or the name of a
     Python package whose directory should be used as the base directory
     for module-relative filenames in 'paths'.  If no package is
     specified, then the calling module’s directory is used as the base
     directory for module-relative filenames.  It is an error to specify
     'package' if 'module_relative' is ‘False’.

     Optional argument 'setUp' specifies a set-up function for the test
     suite.  This is called before running the tests in each file.  The
     'setUp' function will be passed a *note DocTest: 1a11. object.  The
     'setUp' function can access the test globals as the *note globs:
     4573. attribute of the test passed.

     Optional argument 'tearDown' specifies a tear-down function for the
     test suite.  This is called after running the tests in each file.
     The 'tearDown' function will be passed a *note DocTest: 1a11.
     object.  The 'tearDown' function can access the test globals as the
     *note globs: 4573. attribute of the test passed.

     Optional argument 'globs' is a dictionary containing the initial
     global variables for the tests.  A new copy of this dictionary is
     created for each test.  By default, 'globs' is a new empty
     dictionary.

     Optional argument 'optionflags' specifies the default doctest
     options for the tests, created by or-ing together individual option
     flags.  See section *note Option Flags: 1135.  See function *note
     set_unittest_reportflags(): 4574. below for a better way to set
     reporting options.

     Optional argument 'parser' specifies a *note DocTestParser: 4553.
     (or subclass) that should be used to extract tests from the files.
     It defaults to a normal parser (i.e., ‘DocTestParser()’).

     Optional argument 'encoding' specifies an encoding that should be
     used to convert the file to unicode.

     The global ‘__file__’ is added to the globals provided to doctests
     loaded from a text file using *note DocFileSuite(): 4571.

 -- Funzione: doctest.DocTestSuite (module=None, globs=None,
          extraglobs=None, test_finder=None, setUp=None, tearDown=None,
          optionflags=0, checker=None)

     Convert doctest tests for a module to a *note unittest.TestSuite:
     ff7.

     The returned *note unittest.TestSuite: ff7. is to be run by the
     unittest framework and runs each doctest in the module.  Each
     docstring is run as a separate unit test.  If any of the doctests
     fail, then the synthesized unit test fails, and a *note
     unittest.TestCase.failureException: 4572. exception is raised
     showing the name of the file containing the test and a (sometimes
     approximate) line number.  If all the examples in a docstring are
     skipped, then the

     Optional argument 'module' provides the module to be tested.  It
     can be a module object or a (possibly dotted) module name.  If not
     specified, the module calling this function is used.

     Optional argument 'globs' is a dictionary containing the initial
     global variables for the tests.  A new copy of this dictionary is
     created for each test.  By default, 'globs' is the module’s *note
     __dict__: 2356.

     Optional argument 'extraglobs' specifies an extra set of global
     variables, which is merged into 'globs'.  By default, no extra
     globals are used.

     Optional argument 'test_finder' is the *note DocTestFinder: 1990.
     object (or a drop-in replacement) that is used to extract doctests
     from the module.

     Optional arguments 'setUp', 'tearDown', and 'optionflags' are the
     same as for function *note DocFileSuite(): 4571. above, but they
     are called for each docstring.

     This function uses the same search technique as *note testmod():
     1674.

     Cambiato nella versione 3.5: *note DocTestSuite(): ff6. returns an
     empty *note unittest.TestSuite: ff7. if 'module' contains no
     docstrings instead of raising *note ValueError: 2ec.

Under the covers, *note DocTestSuite(): ff6. creates a *note
unittest.TestSuite: ff7. out of ‘doctest.DocTestCase’ instances, and
‘DocTestCase’ is a subclass of *note unittest.TestCase: 2b3.
‘DocTestCase’ isn’t documented here (it’s an internal detail), but
studying its code can answer questions about the exact details of *note
unittest: 10c. integration.

Similarly, *note DocFileSuite(): 4571. creates a *note
unittest.TestSuite: ff7. out of ‘doctest.DocFileCase’ instances, and
‘DocFileCase’ is a subclass of ‘DocTestCase’.

So both ways of creating a *note unittest.TestSuite: ff7. run instances
of ‘DocTestCase’.  This is important for a subtle reason: when you run
*note doctest: 3e. functions yourself, you can control the ‘doctest’
options in use directly, by passing option flags to ‘doctest’ functions.
However, if you’re writing a *note unittest: 10c. framework, ‘unittest’
ultimately controls when and how tests get run.  The framework author
typically wants to control ‘doctest’ reporting options (perhaps, e.g.,
specified by command line options), but there’s no way to pass options
through ‘unittest’ to ‘doctest’ test runners.

For this reason, *note doctest: 3e. also supports a notion of ‘doctest’
reporting flags specific to *note unittest: 10c. support, via this
function:

 -- Funzione: doctest.set_unittest_reportflags (flags)

     Set the *note doctest: 3e. reporting flags to use.

     Argument 'flags' takes the *note bitwise OR: 24a9. of option flags.
     See section *note Option Flags: 1135.  Only «reporting flags» can
     be used.

     This is a module-global setting, and affects all future doctests
     run by module *note unittest: 10c.: the ‘runTest()’ method of
     ‘DocTestCase’ looks at the option flags specified for the test case
     when the ‘DocTestCase’ instance was constructed.  If no reporting
     flags were specified (which is the typical and expected case),
     ‘doctest’’s ‘unittest’ reporting flags are *note bitwise ORed:
     24a9. into the option flags, and the option flags so augmented are
     passed to the *note DocTestRunner: 4562. instance created to run
     the doctest.  If any reporting flags were specified when the
     ‘DocTestCase’ instance was constructed, ‘doctest’’s ‘unittest’
     reporting flags are ignored.

     The value of the *note unittest: 10c. reporting flags in effect
     before the function was called is returned by the function.


File: python.info,  Node: Advanced API,  Next: Debugging,  Prev: Unittest API,  Up: doctest — Test interactive Python examples

5.26.4.14 Advanced API
......................

The basic API is a simple wrapper that’s intended to make doctest easy
to use.  It is fairly flexible, and should meet most users” needs;
however, if you require more fine-grained control over testing, or wish
to extend doctest’s capabilities, then you should use the advanced API.

The advanced API revolves around two container classes, which are used
to store the interactive examples extracted from doctest cases:

   * *note Example: 4577.: A single Python *note statement: 2be2, paired
     with its expected output.

   * *note DocTest: 1a11.: A collection of *note Example: 4577.s,
     typically extracted from a single docstring or text file.

Additional processing classes are defined to find, parse, and run, and
check doctest examples:

   * *note DocTestFinder: 1990.: Finds all docstrings in a given module,
     and uses a *note DocTestParser: 4553. to create a *note DocTest:
     1a11. from every docstring that contains interactive examples.

   * *note DocTestParser: 4553.: Creates a *note DocTest: 1a11. object
     from a string (such as an object’s docstring).

   * *note DocTestRunner: 4562.: Executes the examples in a *note
     DocTest: 1a11, and uses an *note OutputChecker: 4561. to verify
     their output.

   * *note OutputChecker: 4561.: Compares the actual output from a
     doctest example with the expected output, and decides whether they
     match.

The relationships among these processing classes are summarized in the
following diagram:

                                 list of:
     +------+                   +---------+
     |module| --DocTestFinder-> | DocTest | --DocTestRunner-> results
     +------+    |        ^     +---------+     |       ^    (printed)
                 |        |     | Example |     |       |
                 v        |     |   ...   |     v       |
                DocTestParser   | Example |   OutputChecker
                                +---------+

* Menu:

* DocTest Objects::
* Example Objects::
* DocTestFinder objects::
* DocTestParser objects::
* TestResults objects::
* DocTestRunner objects::
* OutputChecker objects::


File: python.info,  Node: DocTest Objects,  Next: Example Objects,  Up: Advanced API

5.26.4.15 DocTest Objects
.........................

 -- Classe: doctest.DocTest (examples, globs, name, filename, lineno,
          docstring)

     A collection of doctest examples that should be run in a single
     namespace.  The constructor arguments are used to initialize the
     attributes of the same names.

     *note DocTest: 1a11. defines the following attributes.  They are
     initialized by the constructor, and should not be modified
     directly.

      -- Attributo: examples

          A list of *note Example: 4577. objects encoding the individual
          interactive Python examples that should be run by this test.

      -- Attributo: globs

          The namespace (aka globals) that the examples should be run
          in.  This is a dictionary mapping names to values.  Any
          changes to the namespace made by the examples (such as binding
          new variables) will be reflected in *note globs: 4573. after
          the test is run.

      -- Attributo: name

          A string name identifying the *note DocTest: 1a11.  Typically,
          this is the name of the object or file that the test was
          extracted from.

      -- Attributo: filename

          The name of the file that this *note DocTest: 1a11. was
          extracted from; or ‘None’ if the filename is unknown, or if
          the ‘DocTest’ was not extracted from a file.

      -- Attributo: lineno

          The line number within *note filename: 457c. where this *note
          DocTest: 1a11. begins, or ‘None’ if the line number is
          unavailable.  This line number is zero-based with respect to
          the beginning of the file.

      -- Attributo: docstring

          The string that the test was extracted from, or ‘None’ if the
          string is unavailable, or if the test was not extracted from a
          string.


File: python.info,  Node: Example Objects,  Next: DocTestFinder objects,  Prev: DocTest Objects,  Up: Advanced API

5.26.4.16 Example Objects
.........................

 -- Classe: doctest.Example (source, want, exc_msg=None, lineno=0,
          indent=0, options=None)

     A single interactive example, consisting of a Python statement and
     its expected output.  The constructor arguments are used to
     initialize the attributes of the same names.

     *note Example: 4577. defines the following attributes.  They are
     initialized by the constructor, and should not be modified
     directly.

      -- Attributo: source

          A string containing the example’s source code.  This source
          code consists of a single Python statement, and always ends
          with a newline; the constructor adds a newline when necessary.

      -- Attributo: want

          The expected output from running the example’s source code
          (either from stdout, or a traceback in case of exception).
          *note want: 4581. ends with a newline unless no output is
          expected, in which case it’s an empty string.  The constructor
          adds a newline when necessary.

      -- Attributo: exc_msg

          The exception message generated by the example, if the example
          is expected to generate an exception; or ‘None’ if it is not
          expected to generate an exception.  This exception message is
          compared against the return value of *note
          traceback.format_exception_only(): a50.  *note exc_msg: 4582.
          ends with a newline unless it’s ‘None’.  The constructor adds
          a newline if needed.

      -- Attributo: lineno

          The line number within the string containing this example
          where the example begins.  This line number is zero-based with
          respect to the beginning of the containing string.

      -- Attributo: indent

          The example’s indentation in the containing string, i.e., the
          number of space characters that precede the example’s first
          prompt.

      -- Attributo: options

          A dictionary mapping from option flags to ‘True’ or ‘False’,
          which is used to override default options for this example.
          Any option flags not contained in this dictionary are left at
          their default value (as specified by the *note DocTestRunner:
          4562.’s *note optionflags: 1135.).  By default, no options are
          set.


File: python.info,  Node: DocTestFinder objects,  Next: DocTestParser objects,  Prev: Example Objects,  Up: Advanced API

5.26.4.17 DocTestFinder objects
...............................

 -- Classe: doctest.DocTestFinder (verbose=False,
          parser=DocTestParser(), recurse=True, exclude_empty=True)

     A processing class used to extract the *note DocTest: 1a11.s that
     are relevant to a given object, from its docstring and the
     docstrings of its contained objects.  *note DocTest: 1a11.s can be
     extracted from modules, classes, functions, methods, staticmethods,
     classmethods, and properties.

     The optional argument 'verbose' can be used to display the objects
     searched by the finder.  It defaults to ‘False’ (no output).

     The optional argument 'parser' specifies the *note DocTestParser:
     4553. object (or a drop-in replacement) that is used to extract
     doctests from docstrings.

     If the optional argument 'recurse' is false, then *note
     DocTestFinder.find(): 1a57. will only examine the given object, and
     not any contained objects.

     If the optional argument 'exclude_empty' is false, then *note
     DocTestFinder.find(): 1a57. will include tests for objects with
     empty docstrings.

     *note DocTestFinder: 1990. defines the following method:

      -- Metodo: find (obj[, name][, module][, globs][, extraglobs])

          Return a list of the *note DocTest: 1a11.s that are defined by
          'obj'’s docstring, or by any of its contained objects”
          docstrings.

          The optional argument 'name' specifies the object’s name; this
          name will be used to construct names for the returned *note
          DocTest: 1a11.s.  If 'name' is not specified, then
          ‘obj.__name__’ is used.

          The optional parameter 'module' is the module that contains
          the given object.  If the module is not specified or is
          ‘None’, then the test finder will attempt to automatically
          determine the correct module.  The object’s module is used:

             * As a default namespace, if 'globs' is not specified.

             * To prevent the DocTestFinder from extracting DocTests
               from objects that are imported from other modules.
               (Contained objects with modules other than 'module' are
               ignored.)

             * To find the name of the file containing the object.

             * To help find the line number of the object within its
               file.

          If 'module' is ‘False’, no attempt to find the module will be
          made.  This is obscure, of use mostly in testing doctest
          itself: if 'module' is ‘False’, or is ‘None’ but cannot be
          found automatically, then all objects are considered to belong
          to the (non-existent) module, so all contained objects will
          (recursively) be searched for doctests.

          The globals for each *note DocTest: 1a11. is formed by
          combining 'globs' and 'extraglobs' (bindings in 'extraglobs'
          override bindings in 'globs').  A new shallow copy of the
          globals dictionary is created for each ‘DocTest’.  If 'globs'
          is not specified, then it defaults to the module’s *note
          __dict__: 2356, if specified, or ‘{}’ otherwise.  If
          'extraglobs' is not specified, then it defaults to ‘{}’.


File: python.info,  Node: DocTestParser objects,  Next: TestResults objects,  Prev: DocTestFinder objects,  Up: Advanced API

5.26.4.18 DocTestParser objects
...............................

 -- Classe: doctest.DocTestParser

     A processing class used to extract interactive examples from a
     string, and use them to create a *note DocTest: 1a11. object.

     *note DocTestParser: 4553. defines the following methods:

      -- Metodo: get_doctest (string, globs, name, filename, lineno)

          Extract all doctest examples from the given string, and
          collect them into a *note DocTest: 1a11. object.

          'globs', 'name', 'filename', and 'lineno' are attributes for
          the new ‘DocTest’ object.  See the documentation for *note
          DocTest: 1a11. for more information.

      -- Metodo: get_examples (string, name='<string>')

          Extract all doctest examples from the given string, and return
          them as a list of *note Example: 4577. objects.  Line numbers
          are 0-based.  The optional argument 'name' is a name
          identifying this string, and is only used for error messages.

      -- Metodo: parse (string, name='<string>')

          Divide the given string into examples and intervening text,
          and return them as a list of alternating *note Example: 4577.s
          and strings.  Line numbers for the ‘Example’s are 0-based.
          The optional argument 'name' is a name identifying this
          string, and is only used for error messages.


File: python.info,  Node: TestResults objects,  Next: DocTestRunner objects,  Prev: DocTestParser objects,  Up: Advanced API

5.26.4.19 TestResults objects
.............................

 -- Classe: doctest.TestResults (failed, attempted)

      -- Attributo: failed

          Number of failed tests.

      -- Attributo: attempted

          Number of attempted tests.

      -- Attributo: skipped

          Number of skipped tests.

          Added in version 3.13.


File: python.info,  Node: DocTestRunner objects,  Next: OutputChecker objects,  Prev: TestResults objects,  Up: Advanced API

5.26.4.20 DocTestRunner objects
...............................

 -- Classe: doctest.DocTestRunner (checker=None, verbose=None,
          optionflags=0)

     A processing class used to execute and verify the interactive
     examples in a *note DocTest: 1a11.

     The comparison between expected outputs and actual outputs is done
     by an *note OutputChecker: 4561.  This comparison may be customized
     with a number of option flags; see section *note Option Flags:
     1135. for more information.  If the option flags are insufficient,
     then the comparison may also be customized by passing a subclass of
     ‘OutputChecker’ to the constructor.

     The test runner’s display output can be controlled in two ways.
     First, an output function can be passed to *note run(): 4ef.; this
     function will be called with strings that should be displayed.  It
     defaults to ‘sys.stdout.write’.  If capturing the output is not
     sufficient, then the display output can be also customized by
     subclassing DocTestRunner, and overriding the methods *note
     report_start(): 4593, *note report_success(): 4594, *note
     report_unexpected_exception(): 4595, and *note report_failure():
     4596.

     The optional keyword argument 'checker' specifies the *note
     OutputChecker: 4561. object (or drop-in replacement) that should be
     used to compare the expected outputs to the actual outputs of
     doctest examples.

     The optional keyword argument 'verbose' controls the *note
     DocTestRunner: 4562.’s verbosity.  If 'verbose' is ‘True’, then
     information is printed about each example, as it is run.  If
     'verbose' is ‘False’, then only failures are printed.  If 'verbose'
     is unspecified, or ‘None’, then verbose output is used iff the
     command-line switch ‘-v’ is used.

     The optional keyword argument 'optionflags' can be used to control
     how the test runner compares expected output to actual output, and
     how it displays failures.  For more information, see section *note
     Option Flags: 1135.

     The test runner accumulates statistics.  The aggregated number of
     attempted, failed and skipped examples is also available via the
     *note tries: 4597, *note failures: 4598. and *note skips: 4f0.
     attributes.  The *note run(): 4ef. and *note summarize(): 456c.
     methods return a *note TestResults: 458e. instance.

     *note DocTestRunner: 4562. defines the following methods:

      -- Metodo: report_start (out, test, example)

          Report that the test runner is about to process the given
          example.  This method is provided to allow subclasses of *note
          DocTestRunner: 4562. to customize their output; it should not
          be called directly.

          'example' is the example about to be processed.  'test' is the
          test containing 'example'.  'out' is the output function that
          was passed to *note DocTestRunner.run(): 4ef.

      -- Metodo: report_success (out, test, example, got)

          Report that the given example ran successfully.  This method
          is provided to allow subclasses of *note DocTestRunner: 4562.
          to customize their output; it should not be called directly.

          'example' is the example about to be processed.  'got' is the
          actual output from the example.  'test' is the test containing
          'example'.  'out' is the output function that was passed to
          *note DocTestRunner.run(): 4ef.

      -- Metodo: report_failure (out, test, example, got)

          Report that the given example failed.  This method is provided
          to allow subclasses of *note DocTestRunner: 4562. to customize
          their output; it should not be called directly.

          'example' is the example about to be processed.  'got' is the
          actual output from the example.  'test' is the test containing
          'example'.  'out' is the output function that was passed to
          *note DocTestRunner.run(): 4ef.

      -- Metodo: report_unexpected_exception (out, test, example,
               exc_info)

          Report that the given example raised an unexpected exception.
          This method is provided to allow subclasses of *note
          DocTestRunner: 4562. to customize their output; it should not
          be called directly.

          'example' is the example about to be processed.  'exc_info' is
          a tuple containing information about the unexpected exception
          (as returned by *note sys.exc_info(): 89b.).  'test' is the
          test containing 'example'.  'out' is the output function that
          was passed to *note DocTestRunner.run(): 4ef.

      -- Metodo: run (test, compileflags=None, out=None,
               clear_globs=True)

          Run the examples in 'test' (a *note DocTest: 1a11. object),
          and display the results using the writer function 'out'.
          Return a *note TestResults: 458e. instance.

          The examples are run in the namespace ‘test.globs’.  If
          'clear_globs' is true (the default), then this namespace will
          be cleared after the test runs, to help with garbage
          collection.  If you would like to examine the namespace after
          the test completes, then use 'clear_globs=False'.

          'compileflags' gives the set of flags that should be used by
          the Python compiler when running the examples.  If not
          specified, then it will default to the set of future-import
          flags that apply to 'globs'.

          The output of each example is checked using the *note
          DocTestRunner: 4562.’s output checker, and the results are
          formatted by the ‘DocTestRunner.report_*()’ methods.

      -- Metodo: summarize (verbose=None)

          Print a summary of all the test cases that have been run by
          this DocTestRunner, and return a *note TestResults: 458e.
          instance.

          The optional 'verbose' argument controls how detailed the
          summary is.  If the verbosity is not specified, then the *note
          DocTestRunner: 4562.’s verbosity is used.

     *note DocTestParser: 4553. has the following attributes:

      -- Attributo: tries

          Number of attempted examples.

      -- Attributo: failures

          Number of failed examples.

      -- Attributo: skips

          Number of skipped examples.

          Added in version 3.13.


File: python.info,  Node: OutputChecker objects,  Prev: DocTestRunner objects,  Up: Advanced API

5.26.4.21 OutputChecker objects
...............................

 -- Classe: doctest.OutputChecker

     A class used to check the whether the actual output from a doctest
     example matches the expected output.  *note OutputChecker: 4561.
     defines two methods: *note check_output(): 459b, which compares a
     given pair of outputs, and returns ‘True’ if they match; and *note
     output_difference(): 459c, which returns a string describing the
     differences between two outputs.

     *note OutputChecker: 4561. defines the following methods:

      -- Metodo: check_output (want, got, optionflags)

          Return ‘True’ iff the actual output from an example ('got')
          matches the expected output ('want').  These strings are
          always considered to match if they are identical; but
          depending on what option flags the test runner is using,
          several non-exact match types are also possible.  See section
          *note Option Flags: 1135. for more information about option
          flags.

      -- Metodo: output_difference (example, got, optionflags)

          Return a string describing the differences between the
          expected output for a given example ('example') and the actual
          output ('got').  'optionflags' is the set of option flags used
          to compare 'want' and 'got'.


File: python.info,  Node: Debugging,  Next: Soapbox,  Prev: Advanced API,  Up: doctest — Test interactive Python examples

5.26.4.22 Debugging
...................

Doctest provides several mechanisms for debugging doctest examples:

   * Several functions convert doctests to executable Python programs,
     which can be run under the Python debugger, *note pdb: aa.

   * The *note DebugRunner: 459f. class is a subclass of *note
     DocTestRunner: 4562. that raises an exception for the first failing
     example, containing information about that example.  This
     information can be used to perform post-mortem debugging on the
     example.

   * The *note unittest: 10c. cases generated by *note DocTestSuite():
     ff6. support the *note debug(): 45a0. method defined by *note
     unittest.TestCase: 2b3.

   * You can add a call to *note pdb.set_trace(): 272. in a doctest
     example, and you’ll drop into the Python debugger when that line is
     executed.  Then you can inspect current values of variables, and so
     on.  For example, suppose ‘a.py’ contains just this module
     docstring:

          """
          >>> def f(x):
          ...     g(x*2)
          >>> def g(x):
          ...     print(x+3)
          ...     import pdb; pdb.set_trace()
          >>> f(3)
          9
          """

     Then an interactive Python session may look like this:

          >>> import a, doctest
          >>> doctest.testmod(a)
          --Return--
          > <doctest a[1]>(3)g()->None
          -> import pdb; pdb.set_trace()
          (Pdb) list
            1     def g(x):
            2         print(x+3)
            3  ->     import pdb; pdb.set_trace()
          [EOF]
          (Pdb) p x
          6
          (Pdb) step
          --Return--
          > <doctest a[0]>(2)f()->None
          -> g(x*2)
          (Pdb) list
            1     def f(x):
            2  ->     g(x*2)
          [EOF]
          (Pdb) p x
          3
          (Pdb) step
          --Return--
          > <doctest a[2]>(1)?()->None
          -> f(3)
          (Pdb) cont
          (0, 3)
          >>>

Functions that convert doctests to Python code, and possibly run the
synthesized code under the debugger:

 -- Funzione: doctest.script_from_examples (s)

     Convert text with examples to a script.

     Argument 's' is a string containing doctest examples.  The string
     is converted to a Python script, where doctest examples in 's' are
     converted to regular code, and everything else is converted to
     Python comments.  The generated script is returned as a string.
     For example,

          import doctest
          print(doctest.script_from_examples(r"""
              Set x and y to 1 and 2.
              >>> x, y = 1, 2

              Print their sum:
              >>> print(x+y)
              3
          """))

     displays:

          # Set x and y to 1 and 2.
          x, y = 1, 2
          #
          # Print their sum:
          print(x+y)
          # Expected:
          ## 3

     This function is used internally by other functions (see below),
     but can also be useful when you want to transform an interactive
     Python session into a Python script.

 -- Funzione: doctest.testsource (module, name)

     Convert the doctest for an object to a script.

     Argument 'module' is a module object, or dotted name of a module,
     containing the object whose doctests are of interest.  Argument
     'name' is the name (within the module) of the object with the
     doctests of interest.  The result is a string, containing the
     object’s docstring converted to a Python script, as described for
     *note script_from_examples(): 45a1. above.  For example, if module
     ‘a.py’ contains a top-level function ‘f()’, then

          import a, doctest
          print(doctest.testsource(a, "a.f"))

     prints a script version of function ‘f()’”s docstring, with
     doctests converted to code, and the rest placed in comments.

 -- Funzione: doctest.debug (module, name, pm=False)

     Debug the doctests for an object.

     The 'module' and 'name' arguments are the same as for function
     *note testsource(): 45a2. above.  The synthesized Python script for
     the named object’s docstring is written to a temporary file, and
     then that file is run under the control of the Python debugger,
     *note pdb: aa.

     A shallow copy of ‘module.__dict__’ is used for both local and
     global execution context.

     Optional argument 'pm' controls whether post-mortem debugging is
     used.  If 'pm' has a true value, the script file is run directly,
     and the debugger gets involved only if the script terminates via
     raising an unhandled exception.  If it does, then post-mortem
     debugging is invoked, via *note pdb.post_mortem(): 15e1, passing
     the traceback object from the unhandled exception.  If 'pm' is not
     specified, or is false, the script is run under the debugger from
     the start, via passing an appropriate *note exec(): 4a3. call to
     *note pdb.run(): 45a3.

 -- Funzione: doctest.debug_src (src, pm=False, globs=None)

     Debug the doctests in a string.

     This is like function *note debug(): 45a0. above, except that a
     string containing doctest examples is specified directly, via the
     'src' argument.

     Optional argument 'pm' has the same meaning as in function *note
     debug(): 45a0. above.

     Optional argument 'globs' gives a dictionary to use as both local
     and global execution context.  If not specified, or ‘None’, an
     empty dictionary is used.  If specified, a shallow copy of the
     dictionary is used.

The *note DebugRunner: 459f. class, and the special exceptions it may
raise, are of most interest to testing framework authors, and will only
be sketched here.  See the source code, and especially *note
DebugRunner: 459f.’s docstring (which is a doctest!)  for more details:

 -- Classe: doctest.DebugRunner (checker=None, verbose=None,
          optionflags=0)

     A subclass of *note DocTestRunner: 4562. that raises an exception
     as soon as a failure is encountered.  If an unexpected exception
     occurs, an *note UnexpectedException: 45a5. exception is raised,
     containing the test, the example, and the original exception.  If
     the output doesn’t match, then a *note DocTestFailure: 45a6.
     exception is raised, containing the test, the example, and the
     actual output.

     For information about the constructor parameters and methods, see
     the documentation for *note DocTestRunner: 4562. in section *note
     Advanced API: 4576.

There are two exceptions that may be raised by *note DebugRunner: 459f.
instances:

 -- Eccezione: doctest.DocTestFailure (test, example, got)

     An exception raised by *note DocTestRunner: 4562. to signal that a
     doctest example’s actual output did not match its expected output.
     The constructor arguments are used to initialize the attributes of
     the same names.

*note DocTestFailure: 45a6. defines the following attributes:

 -- Attributo: DocTestFailure.test

     The *note DocTest: 1a11. object that was being run when the example
     failed.

 -- Attributo: DocTestFailure.example

     The *note Example: 4577. that failed.

 -- Attributo: DocTestFailure.got

     The example’s actual output.

 -- Eccezione: doctest.UnexpectedException (test, example, exc_info)

     An exception raised by *note DocTestRunner: 4562. to signal that a
     doctest example raised an unexpected exception.  The constructor
     arguments are used to initialize the attributes of the same names.

*note UnexpectedException: 45a5. defines the following attributes:

 -- Attributo: UnexpectedException.test

     The *note DocTest: 1a11. object that was being run when the example
     failed.

 -- Attributo: UnexpectedException.example

     The *note Example: 4577. that failed.

 -- Attributo: UnexpectedException.exc_info

     A tuple containing information about the unexpected exception, as
     returned by *note sys.exc_info(): 89b.


File: python.info,  Node: Soapbox,  Prev: Debugging,  Up: doctest — Test interactive Python examples

5.26.4.23 Soapbox
.................

As mentioned in the introduction, *note doctest: 3e. has grown to have
three primary uses:

  1. Checking examples in docstrings.

  2. Regression testing.

  3. Executable documentation / literate testing.

These uses have different requirements, and it is important to
distinguish them.  In particular, filling your docstrings with obscure
test cases makes for bad documentation.

When writing a docstring, choose docstring examples with care.  There’s
an art to this that needs to be learned—it may not be natural at first.
Examples should add genuine value to the documentation.  A good example
can often be worth many words.  If done with care, the examples will be
invaluable for your users, and will pay back the time it takes to
collect them many times over as the years go by and things change.  I’m
still amazed at how often one of my *note doctest: 3e. examples stops
working after a «harmless» change.

Doctest also makes an excellent tool for regression testing, especially
if you don’t skimp on explanatory text.  By interleaving prose and
examples, it becomes much easier to keep track of what’s actually being
tested, and why.  When a test fails, good prose can make it much easier
to figure out what the problem is, and how it should be fixed.  It’s
true that you could write extensive comments in code-based testing, but
few programmers do.  Many have found that using doctest approaches
instead leads to much clearer tests.  Perhaps this is simply because
doctest makes writing prose a little easier than writing code, while
writing comments in code is a little harder.  I think it goes deeper
than just that: the natural attitude when writing a doctest-based test
is that you want to explain the fine points of your software, and
illustrate them with examples.  This in turn naturally leads to test
files that start with the simplest features, and logically progress to
complications and edge cases.  A coherent narrative is the result,
instead of a collection of isolated functions that test isolated bits of
functionality seemingly at random.  It’s a different attitude, and
produces different results, blurring the distinction between testing and
explaining.

Regression testing is best confined to dedicated objects or files.
There are several options for organizing tests:

   * Write text files containing test cases as interactive examples, and
     test the files using *note testfile(): 4542. or *note
     DocFileSuite(): 4571.  This is recommended, although is easiest to
     do for new projects, designed from the start to use doctest.

   * Define functions named ‘_regrtest_topic’ that consist of single
     docstrings, containing test cases for the named topics.  These
     functions can be included in the same file as the module, or
     separated out into a separate test file.

   * Define a *note __test__: 454e. dictionary mapping from regression
     test topics to docstrings containing test cases.

When you have placed your tests in a module, the module can itself be
the test runner.  When a test fails, you can arrange for your test
runner to re-run only the failing doctest while you debug the problem.
Here is a minimal example of such a test runner:

     if __name__ == '__main__':
         import doctest
         flags = doctest.REPORT_NDIFF|doctest.FAIL_FAST
         if len(sys.argv) > 1:
             name = sys.argv[1]
             if name in globals():
                 obj = globals()[name]
             else:
                 obj = __test__[name]
             doctest.run_docstring_examples(obj, globals(), name=name,
                                            optionflags=flags)
         else:
             fail, total = doctest.testmod(optionflags=flags)
             print(f"{fail} failures out of {total} tests")


File: python.info,  Node: unittest — Unit testing framework,  Next: unittest mock — mock object library,  Prev: doctest — Test interactive Python examples,  Up: Development Tools

5.26.5 ‘unittest’ — Unit testing framework
------------------------------------------

'Source code:' Lib/unittest/__init__.py(1)

__________________________________________________________________

(If you are already familiar with the basic concepts of testing, you
might want to skip to *note the list of assert methods: 45b2.)

The *note unittest: 10c. unit testing framework was originally inspired
by JUnit and has a similar flavor as major unit testing frameworks in
other languages.  It supports test automation, sharing of setup and
shutdown code for tests, aggregation of tests into collections, and
independence of the tests from the reporting framework.

To achieve this, *note unittest: 10c. supports some important concepts
in an object-oriented way:

test fixture

     A 'test fixture' represents the preparation needed to perform one
     or more tests, and any associated cleanup actions.  This may
     involve, for example, creating temporary or proxy databases,
     directories, or starting a server process.

test case

     A 'test case' is the individual unit of testing.  It checks for a
     specific response to a particular set of inputs.  *note unittest:
     10c. provides a base class, *note TestCase: 2b3, which may be used
     to create new test cases.

test suite

     A 'test suite' is a collection of test cases, test suites, or both.
     It is used to aggregate tests that should be executed together.

test runner

     A 'test runner' is a component which orchestrates the execution of
     tests and provides the outcome to the user.  The runner may use a
     graphical interface, a textual interface, or return a special value
     to indicate the results of executing the tests.

Vedi anche
..........

Module *note doctest: 3e.

     Another test-support module with a very different flavor.

Simple Smalltalk Testing: With Patterns(2)

     Kent Beck’s original paper on testing frameworks using the pattern
     shared by *note unittest: 10c.

pytest(3)

     Third-party unittest framework with a lighter-weight syntax for
     writing tests.  For example, ‘assert func(10) == 42’.

The Python Testing Tools Taxonomy(4)

     An extensive list of Python testing tools including functional
     testing frameworks and mock object libraries.

Testing in Python Mailing List(5)

     A special-interest-group for discussion of testing, and testing
     tools, in Python.

The script ‘Tools/unittestgui/unittestgui.py’ in the Python source
distribution is a GUI tool for test discovery and execution.  This is
intended largely for ease of use for those new to unit testing.  For
production environments it is recommended that tests be driven by a
continuous integration system such as Buildbot(6), Jenkins(7), GitHub
Actions(8), or AppVeyor(9).

* Menu:

* Basic example::
* Command-Line Interface: Command-Line Interface<2>.
* Test Discovery::
* Organizing test code::
* Re-using old test code::
* Skipping tests and expected failures::
* Distinguishing test iterations using subtests::
* Classes and functions::
* Class and Module Fixtures::
* Signal Handling::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/unittest/__init__.py

   (2) 
https://web.archive.org/web/20150315073817/http://www.xprogramming.com/testfram.htm

   (3) https://docs.pytest.org/

   (4) https://wiki.python.org/moin/PythonTestingToolsTaxonomy

   (5) http://lists.idyll.org/listinfo/testing-in-python

   (6) https://buildbot.net/

   (7) https://www.jenkins.io/

   (8) https://github.com/features/actions

   (9) https://www.appveyor.com/


File: python.info,  Node: Basic example,  Next: Command-Line Interface<2>,  Up: unittest — Unit testing framework

5.26.5.1 Basic example
......................

The *note unittest: 10c. module provides a rich set of tools for
constructing and running tests.  This section demonstrates that a small
subset of the tools suffice to meet the needs of most users.

Here is a short script to test three string methods:

     import unittest

     class TestStringMethods(unittest.TestCase):

         def test_upper(self):
             self.assertEqual('foo'.upper(), 'FOO')

         def test_isupper(self):
             self.assertTrue('FOO'.isupper())
             self.assertFalse('Foo'.isupper())

         def test_split(self):
             s = 'hello world'
             self.assertEqual(s.split(), ['hello', 'world'])
             # check that s.split fails when the separator is not a string
             with self.assertRaises(TypeError):
                 s.split(2)

     if __name__ == '__main__':
         unittest.main()

A test case is created by subclassing *note unittest.TestCase: 2b3.  The
three individual tests are defined with methods whose names start with
the letters ‘test’.  This naming convention informs the test runner
about which methods represent tests.

The crux of each test is a call to *note assertEqual(): 74d. to check
for an expected result; *note assertTrue(): 74b. or *note assertFalse():
74c. to verify a condition; or *note assertRaises(): 751. to verify that
a specific exception gets raised.  These methods are used instead of the
*note assert: b62. statement so the test runner can accumulate all test
results and produce a report.

The *note setUp(): 1541. and *note tearDown(): 1542. methods allow you
to define instructions that will be executed before and after each test
method.  They are covered in more detail in the section *note Organizing
test code: 45b5.

The final block shows a simple way to run the tests.  *note
unittest.main(): 11e5. provides a command-line interface to the test
script.  When run from the command line, the above script produces an
output that looks like this:

     ...
     ----------------------------------------------------------------------
     Ran 3 tests in 0.000s

     OK

Passing the ‘-v’ option to your test script will instruct *note
unittest.main(): 11e5. to enable a higher level of verbosity, and
produce the following output:

     test_isupper (__main__.TestStringMethods.test_isupper) ... ok
     test_split (__main__.TestStringMethods.test_split) ... ok
     test_upper (__main__.TestStringMethods.test_upper) ... ok

     ----------------------------------------------------------------------
     Ran 3 tests in 0.001s

     OK

The above examples show the most commonly used *note unittest: 10c.
features which are sufficient to meet many everyday testing needs.  The
remainder of the documentation explores the full feature set from first
principles.

Cambiato nella versione 3.11: The behavior of returning a value from a
test method (other than the default ‘None’ value), is now deprecated.


File: python.info,  Node: Command-Line Interface<2>,  Next: Test Discovery,  Prev: Basic example,  Up: unittest — Unit testing framework

5.26.5.2 Command-Line Interface
...............................

The unittest module can be used from the command line to run tests from
modules, classes or even individual test methods:

     python -m unittest test_module1 test_module2
     python -m unittest test_module.TestClass
     python -m unittest test_module.TestClass.test_method

You can pass in a list with any combination of module names, and fully
qualified class or method names.

Test modules can be specified by file path as well:

     python -m unittest tests/test_something.py

This allows you to use the shell filename completion to specify the test
module.  The file specified must still be importable as a module.  The
path is converted to a module name by removing the “.py” and converting
path separators into “.”.  If you want to execute a test file that isn’t
importable as a module you should execute the file directly instead.

You can run tests with more detail (higher verbosity) by passing in the
-v flag:

     python -m unittest -v test_module

When executed without arguments *note Test Discovery: 45b8. is started:

     python -m unittest

For a list of all the command-line options:

     python -m unittest -h

Cambiato nella versione 3.2: In earlier versions it was only possible to
run individual test methods and not modules or classes.

Added in version 3.14: Output is colorized by default and can be *note
controlled using environment variables: 1b7.

* Menu:

* Command-line options: Command-line options<5>.


File: python.info,  Node: Command-line options<5>,  Up: Command-Line Interface<2>

5.26.5.3 Command-line options
.............................

‘unittest’ supports these command-line options:

 -- Option: -b, --buffer

     The standard output and standard error streams are buffered during
     the test run.  Output during a passing test is discarded.  Output
     is echoed normally on test fail or error and is added to the
     failure messages.

 -- Option: -c, --catch

     ‘Control’-‘C’ during the test run waits for the current test to end
     and then reports all the results so far.  A second ‘Control’-‘C’
     raises the normal *note KeyboardInterrupt: bc7. exception.

     See *note Signal Handling: 45bc. for the functions that provide
     this functionality.

 -- Option: -f, --failfast

     Stop the test run on the first error or failure.

 -- Option: -k

     Only run test methods and classes that match the pattern or
     substring.  This option may be used multiple times, in which case
     all test cases that match any of the given patterns are included.

     Patterns that contain a wildcard character (‘*’) are matched
     against the test name using *note fnmatch.fnmatchcase(): 1c3d.;
     otherwise simple case-sensitive substring matching is used.

     Patterns are matched against the fully qualified test method name
     as imported by the test loader.

     For example, ‘-k foo’ matches ‘foo_tests.SomeTest.test_something’,
     ‘bar_tests.SomeTest.test_foo’, but not
     ‘bar_tests.FooTest.test_something’.

 -- Option: --locals

     Show local variables in tracebacks.

 -- Option: --durations N

     Show the N slowest test cases (N=0 for all).

Added in version 3.2: The command-line options ‘-b’, ‘-c’ and ‘-f’ were
added.

Added in version 3.5: The command-line option ‘--locals’.

Added in version 3.7: The command-line option ‘-k’.

Added in version 3.12: The command-line option ‘--durations’.

The command line can also be used for test discovery, for running all of
the tests in a project or just a subset.


File: python.info,  Node: Test Discovery,  Next: Organizing test code,  Prev: Command-Line Interface<2>,  Up: unittest — Unit testing framework

5.26.5.4 Test Discovery
.......................

Added in version 3.2.

Unittest supports simple test discovery.  In order to be compatible with
test discovery, all of the test files must be *note modules: 2028. or
*note packages: 2038. importable from the top-level directory of the
project (this means that their filenames must be valid *note
identifiers: 2289.).

Test discovery is implemented in *note TestLoader.discover(): 11e7, but
can also be used from the command line.  The basic command-line usage
is:

     cd project_directory
     python -m unittest discover

     Nota: As a shortcut, ‘python -m unittest’ is the equivalent of
     ‘python -m unittest discover’.  If you want to pass arguments to
     test discovery the ‘discover’ sub-command must be used explicitly.

The ‘discover’ sub-command has the following options:

 -- Option: -v, --verbose

     Verbose output

 -- Option: -s, --start-directory directory

     Directory to start discovery (‘.’ default)

 -- Option: -p, --pattern pattern

     Pattern to match test files (‘test*.py’ default)

 -- Option: -t, --top-level-directory directory

     Top level directory of project (defaults to start directory)

The *note -s: 45c4, *note -p: 45c6, and *note -t: 45c8. options can be
passed in as positional arguments in that order.  The following two
command lines are equivalent:

     python -m unittest discover -s project_directory -p "*_test.py"
     python -m unittest discover project_directory "*_test.py"

As well as being a path it is possible to pass a package name, for
example ‘myproject.subpackage.test’, as the start directory.  The
package name you supply will then be imported and its location on the
filesystem will be used as the start directory.

     Attenzione: Test discovery loads tests by importing them.  Once
     test discovery has found all the test files from the start
     directory you specify it turns the paths into package names to
     import.  For example ‘foo/bar/baz.py’ will be imported as
     ‘foo.bar.baz’.

     If you have a package installed globally and attempt test discovery
     on a different copy of the package then the import 'could' happen
     from the wrong place.  If this happens test discovery will warn you
     and exit.

     If you supply the start directory as a package name rather than a
     path to a directory then discover assumes that whichever location
     it imports from is the location you intended, so you will not get
     the warning.

Test modules and packages can customize test loading and discovery by
through the *note load_tests protocol: 45ca.

Cambiato nella versione 3.4: Test discovery supports *note namespace
packages: 2b2.

Cambiato nella versione 3.11: Test discovery dropped the *note namespace
packages: 2b2. support.  It has been broken since Python 3.7.  Start
directory and its subdirectories containing tests must be regular
package that have ‘__init__.py’ file.

If the start directory is the dotted name of the package, the ancestor
packages can be namespace packages.

Cambiato nella versione 3.14: Test discovery supports *note namespace
package: 2b2. as start directory again.  To avoid scanning directories
unrelated to Python, tests are not searched in subdirectories that do
not contain ‘__init__.py’.


File: python.info,  Node: Organizing test code,  Next: Re-using old test code,  Prev: Test Discovery,  Up: unittest — Unit testing framework

5.26.5.5 Organizing test code
.............................

The basic building blocks of unit testing are 'test cases' — single
scenarios that must be set up and checked for correctness.  In *note
unittest: 10c, test cases are represented by *note unittest.TestCase:
2b3. instances.  To make your own test cases you must write subclasses
of *note TestCase: 2b3. or use *note FunctionTestCase: 1a61.

The testing code of a *note TestCase: 2b3. instance should be entirely
self contained, such that it can be run either in isolation or in
arbitrary combination with any number of other test cases.

The simplest *note TestCase: 2b3. subclass will simply implement a test
method (i.e.  a method whose name starts with ‘test’) in order to
perform specific testing code:

     import unittest

     class DefaultWidgetSizeTestCase(unittest.TestCase):
         def test_default_widget_size(self):
             widget = Widget('The widget')
             self.assertEqual(widget.size(), (50, 50))

Note that in order to test something, we use one of the *note assert*
methods: 45b2. provided by the *note TestCase: 2b3. base class.  If the
test fails, an exception will be raised with an explanatory message, and
*note unittest: 10c. will identify the test case as a 'failure'.  Any
other exceptions will be treated as 'errors'.

Tests can be numerous, and their set-up can be repetitive.  Luckily, we
can factor out set-up code by implementing a method called *note
setUp(): 1541, which the testing framework will automatically call for
every single test we run:

     import unittest

     class WidgetTestCase(unittest.TestCase):
         def setUp(self):
             self.widget = Widget('The widget')

         def test_default_widget_size(self):
             self.assertEqual(self.widget.size(), (50,50),
                              'incorrect default size')

         def test_widget_resize(self):
             self.widget.resize(100,150)
             self.assertEqual(self.widget.size(), (100,150),
                              'wrong size after resize')

     Nota: The order in which the various tests will be run is
     determined by sorting the test method names with respect to the
     built-in ordering for strings.

If the *note setUp(): 1541. method raises an exception while the test is
running, the framework will consider the test to have suffered an error,
and the test method will not be executed.

Similarly, we can provide a *note tearDown(): 1542. method that tidies
up after the test method has been run:

     import unittest

     class WidgetTestCase(unittest.TestCase):
         def setUp(self):
             self.widget = Widget('The widget')

         def tearDown(self):
             self.widget.dispose()

If *note setUp(): 1541. succeeded, *note tearDown(): 1542. will be run
whether the test method succeeded or not.

Such a working environment for the testing code is called a 'test
fixture'.  A new TestCase instance is created as a unique test fixture
used to execute each individual test method.  Thus *note setUp(): 1541,
*note tearDown(): 1542, and ‘TestCase.__init__()’ will be called once
per test.

It is recommended that you use TestCase implementations to group tests
together according to the features they test.  *note unittest: 10c.
provides a mechanism for this: the 'test suite', represented by *note
unittest: 10c.’s *note TestSuite: ff7. class.  In most cases, calling
*note unittest.main(): 11e5. will do the right thing and collect all the
module’s test cases for you and execute them.

However, should you want to customize the building of your test suite,
you can do it yourself:

     def suite():
         suite = unittest.TestSuite()
         suite.addTest(WidgetTestCase('test_default_widget_size'))
         suite.addTest(WidgetTestCase('test_widget_resize'))
         return suite

     if __name__ == '__main__':
         runner = unittest.TextTestRunner()
         runner.run(suite())

You can place the definitions of test cases and test suites in the same
modules as the code they are to test (such as ‘widget.py’), but there
are several advantages to placing the test code in a separate module,
such as ‘test_widget.py’:

   * The test module can be run standalone from the command line.

   * The test code can more easily be separated from shipped code.

   * There is less temptation to change test code to fit the code it
     tests without a good reason.

   * Test code should be modified much less frequently than the code it
     tests.

   * Tested code can be refactored more easily.

   * Tests for modules written in C must be in separate modules anyway,
     so why not be consistent?

   * If the testing strategy changes, there is no need to change the
     source code.


File: python.info,  Node: Re-using old test code,  Next: Skipping tests and expected failures,  Prev: Organizing test code,  Up: unittest — Unit testing framework

5.26.5.6 Re-using old test code
...............................

Some users will find that they have existing test code that they would
like to run from *note unittest: 10c, without converting every old test
function to a *note TestCase: 2b3. subclass.

For this reason, *note unittest: 10c. provides a *note FunctionTestCase:
1a61. class.  This subclass of *note TestCase: 2b3. can be used to wrap
an existing test function.  Set-up and tear-down functions can also be
provided.

Given the following test function:

     def testSomething():
         something = makeSomething()
         assert something.name is not None
         # ...

one can create an equivalent test case instance as follows, with
optional set-up and tear-down methods:

     testcase = unittest.FunctionTestCase(testSomething,
                                          setUp=makeSomethingDB,
                                          tearDown=deleteSomethingDB)

     Nota: Even though *note FunctionTestCase: 1a61. can be used to
     quickly convert an existing test base over to a *note unittest:
     10c.-based system, this approach is not recommended.  Taking the
     time to set up proper *note TestCase: 2b3. subclasses will make
     future test refactorings infinitely easier.

In some cases, the existing tests may have been written using the *note
doctest: 3e. module.  If so, *note doctest: 3e. provides a *note
DocTestSuite: ff6. class that can automatically build *note
unittest.TestSuite: ff7. instances from the existing *note doctest:
3e.-based tests.


File: python.info,  Node: Skipping tests and expected failures,  Next: Distinguishing test iterations using subtests,  Prev: Re-using old test code,  Up: unittest — Unit testing framework

5.26.5.7 Skipping tests and expected failures
.............................................

Added in version 3.1.

Unittest supports skipping individual test methods and even whole
classes of tests.  In addition, it supports marking a test as an
«expected failure,» a test that is broken and will fail, but shouldn’t
be counted as a failure on a *note TestResult: 136f.

Skipping a test is simply a matter of using the *note skip(): 1da6.
*note decorator: 93b. or one of its conditional variants, calling *note
TestCase.skipTest(): 45d0. within a *note setUp(): 1541. or test method,
or raising *note SkipTest: 11e6. directly.

Basic skipping looks like this:

     class MyTestCase(unittest.TestCase):

         @unittest.skip("demonstrating skipping")
         def test_nothing(self):
             self.fail("shouldn't happen")

         @unittest.skipIf(mylib.__version__ < (1, 3),
                          "not supported in this library version")
         def test_format(self):
             # Tests that work for only a certain version of the library.
             pass

         @unittest.skipUnless(sys.platform.startswith("win"), "requires Windows")
         def test_windows_support(self):
             # windows specific testing code
             pass

         def test_maybe_skipped(self):
             if not external_resource_available():
                 self.skipTest("external resource not available")
             # test code that depends on the external resource
             pass

This is the output of running the example above in verbose mode:

     test_format (__main__.MyTestCase.test_format) ... skipped 'not supported in this library version'
     test_nothing (__main__.MyTestCase.test_nothing) ... skipped 'demonstrating skipping'
     test_maybe_skipped (__main__.MyTestCase.test_maybe_skipped) ... skipped 'external resource not available'
     test_windows_support (__main__.MyTestCase.test_windows_support) ... skipped 'requires Windows'

     ----------------------------------------------------------------------
     Ran 4 tests in 0.005s

     OK (skipped=4)

Classes can be skipped just like methods:

     @unittest.skip("showing class skipping")
     class MySkippedTestCase(unittest.TestCase):
         def test_not_run(self):
             pass

*note TestCase.setUp(): 1541. can also skip the test.  This is useful
when a resource that needs to be set up is not available.

Expected failures use the *note expectedFailure(): 45d1. decorator.

     class ExpectedFailureTestCase(unittest.TestCase):
         @unittest.expectedFailure
         def test_fail(self):
             self.assertEqual(1, 0, "broken")

It’s easy to roll your own skipping decorators by making a decorator
that calls *note skip(): 1da6. on the test when it wants it to be
skipped.  This decorator skips the test unless the passed object has a
certain attribute:

     def skipUnlessHasattr(obj, attr):
         if hasattr(obj, attr):
             return lambda func: func
         return unittest.skip("{!r} doesn't have {!r}".format(obj, attr))

The following decorators and exception implement test skipping and
expected failures:

 -- Funzione: @unittest.skip (reason)

     Unconditionally skip the decorated test.  'reason' should describe
     why the test is being skipped.

 -- Funzione: @unittest.skipIf (condition, reason)

     Skip the decorated test if 'condition' is true.

 -- Funzione: @unittest.skipUnless (condition, reason)

     Skip the decorated test unless 'condition' is true.

 -- Funzione: @unittest.expectedFailure

     Mark the test as an expected failure or error.  If the test fails
     or errors in the test function itself (rather than in one of the
     'test fixture' methods) then it will be considered a success.  If
     the test passes, it will be considered a failure.

 -- Eccezione: unittest.SkipTest (reason)

     This exception is raised to skip a test.

     Usually you can use *note TestCase.skipTest(): 45d0. or one of the
     skipping decorators instead of raising this directly.

Skipped tests will not have *note setUp(): 1541. or *note tearDown():
1542. run around them.  Skipped classes will not have *note
setUpClass(): c45. or *note tearDownClass(): 153f. run.  Skipped modules
will not have *note setUpModule(): c44. or *note tearDownModule(): 153e.
run.


File: python.info,  Node: Distinguishing test iterations using subtests,  Next: Classes and functions,  Prev: Skipping tests and expected failures,  Up: unittest — Unit testing framework

5.26.5.8 Distinguishing test iterations using subtests
......................................................

Added in version 3.4.

When there are very small differences among your tests, for instance
some parameters, unittest allows you to distinguish them inside the body
of a test method using the *note subTest(): 11e3. context manager.

For example, the following test:

     class NumbersTest(unittest.TestCase):

         def test_even(self):
             """
             Test that numbers between 0 and 5 are all even.
             """
             for i in range(0, 6):
                 with self.subTest(i=i):
                     self.assertEqual(i % 2, 0)

will produce the following output:

     ======================================================================
     FAIL: test_even (__main__.NumbersTest.test_even) (i=1)
     Test that numbers between 0 and 5 are all even.
     ----------------------------------------------------------------------
     Traceback (most recent call last):
       File "subtests.py", line 11, in test_even
         self.assertEqual(i % 2, 0)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^
     AssertionError: 1 != 0

     ======================================================================
     FAIL: test_even (__main__.NumbersTest.test_even) (i=3)
     Test that numbers between 0 and 5 are all even.
     ----------------------------------------------------------------------
     Traceback (most recent call last):
       File "subtests.py", line 11, in test_even
         self.assertEqual(i % 2, 0)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^
     AssertionError: 1 != 0

     ======================================================================
     FAIL: test_even (__main__.NumbersTest.test_even) (i=5)
     Test that numbers between 0 and 5 are all even.
     ----------------------------------------------------------------------
     Traceback (most recent call last):
       File "subtests.py", line 11, in test_even
         self.assertEqual(i % 2, 0)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^
     AssertionError: 1 != 0

Without using a subtest, execution would stop after the first failure,
and the error would be less easy to diagnose because the value of ‘i’
wouldn’t be displayed:

     ======================================================================
     FAIL: test_even (__main__.NumbersTest.test_even)
     ----------------------------------------------------------------------
     Traceback (most recent call last):
       File "subtests.py", line 32, in test_even
         self.assertEqual(i % 2, 0)
     AssertionError: 1 != 0


File: python.info,  Node: Classes and functions,  Next: Class and Module Fixtures,  Prev: Distinguishing test iterations using subtests,  Up: unittest — Unit testing framework

5.26.5.9 Classes and functions
..............................

This section describes in depth the API of *note unittest: 10c.

* Menu:

* Test cases::
* Grouping tests::
* Loading and running tests::


File: python.info,  Node: Test cases,  Next: Grouping tests,  Up: Classes and functions

5.26.5.10 Test cases
....................

 -- Classe: unittest.TestCase (methodName='runTest')

     Instances of the *note TestCase: 2b3. class represent the logical
     test units in the *note unittest: 10c. universe.  This class is
     intended to be used as a base class, with specific tests being
     implemented by concrete subclasses.  This class implements the
     interface needed by the test runner to allow it to drive the tests,
     and methods that the test code can use to check for and report
     various kinds of failure.

     Each instance of *note TestCase: 2b3. will run a single base
     method: the method named 'methodName'.  In most uses of *note
     TestCase: 2b3, you will neither change the 'methodName' nor
     reimplement the default ‘runTest()’ method.

     Cambiato nella versione 3.2: *note TestCase: 2b3. can be
     instantiated successfully without providing a 'methodName'.  This
     makes it easier to experiment with *note TestCase: 2b3. from the
     interactive interpreter.

     *note TestCase: 2b3. instances provide three groups of methods: one
     group used to run the test, another used by the test implementation
     to check conditions and report failures, and some inquiry methods
     allowing information about the test itself to be gathered.

     Methods in the first group (running the test) are:

      -- Metodo: setUp ()

          Method called to prepare the test fixture.  This is called
          immediately before calling the test method; other than *note
          AssertionError: 8b9. or *note SkipTest: 11e6, any exception
          raised by this method will be considered an error rather than
          a test failure.  The default implementation does nothing.

      -- Metodo: tearDown ()

          Method called immediately after the test method has been
          called and the result recorded.  This is called even if the
          test method raised an exception, so the implementation in
          subclasses may need to be particularly careful about checking
          internal state.  Any exception, other than *note
          AssertionError: 8b9. or *note SkipTest: 11e6, raised by this
          method will be considered an additional error rather than a
          test failure (thus increasing the total number of reported
          errors).  This method will only be called if the *note
          setUp(): 1541. succeeds, regardless of the outcome of the test
          method.  The default implementation does nothing.

      -- Metodo: setUpClass ()

          A class method called before tests in an individual class are
          run.  ‘setUpClass’ is called with the class as the only
          argument and must be decorated as a *note classmethod(): 48f.:

               @classmethod
               def setUpClass(cls):
                   ...

          See *note Class and Module Fixtures: 45d9. for more details.

          Added in version 3.2.

      -- Metodo: tearDownClass ()

          A class method called after tests in an individual class have
          run.  ‘tearDownClass’ is called with the class as the only
          argument and must be decorated as a *note classmethod(): 48f.:

               @classmethod
               def tearDownClass(cls):
                   ...

          See *note Class and Module Fixtures: 45d9. for more details.

          Added in version 3.2.

      -- Metodo: run (result=None)

          Run the test, collecting the result into the *note TestResult:
          136f. object passed as 'result'.  If 'result' is omitted or
          ‘None’, a temporary result object is created (by calling the
          *note defaultTestResult(): 45da. method) and used.  The result
          object is returned to *note run(): 136e.”s caller.

          The same effect may be had by simply calling the *note
          TestCase: 2b3. instance.

          Cambiato nella versione 3.3: Previous versions of ‘run’ did
          not return the result.  Neither did calling an instance.

      -- Metodo: skipTest (reason)

          Calling this during a test method or *note setUp(): 1541.
          skips the current test.  See *note Skipping tests and expected
          failures: 45cf. for more information.

          Added in version 3.1.

      -- Metodo: subTest (msg=None, **params)

          Return a context manager which executes the enclosed code
          block as a subtest.  'msg' and 'params' are optional,
          arbitrary values which are displayed whenever a subtest fails,
          allowing you to identify them clearly.

          A test case can contain any number of subtest declarations,
          and they can be arbitrarily nested.

          See *note Distinguishing test iterations using subtests: 11e4.
          for more information.

          Added in version 3.4.

      -- Metodo: debug ()

          Run the test without collecting the result.  This allows
          exceptions raised by the test to be propagated to the caller,
          and can be used to support running tests under a debugger.
     The *note TestCase: 2b3. class provides several assert methods to
     check for and report failures.  The following table lists the most
     commonly used methods (see the tables below for more assert
     methods):

     Method                                        Checks that                       New in
                                                                                     
     ----------------------------------------------------------------------------------------------------
                                                                                     
     *note assertEqual(a, b): 74d.                 ‘a == b’
                                                   
                                                                                     
     *note assertNotEqual(a, b): 74e.              ‘a != b’
                                                   
                                                                                     
     *note assertTrue(x): 74b.                     ‘bool(x) is True’
                                                   
                                                                                     
     *note assertFalse(x): 74c.                    ‘bool(x) is False’
                                                   
                                                                                     
     *note assertIs(a, b): 1543.                   ‘a is b’                          3.1
                                                                                     
                                                                                     
     *note assertIsNot(a, b): 1544.                ‘a is not b’                      3.1
                                                                                     
                                                                                     
     *note assertIsNone(x): 1492.                  ‘x is None’                       3.1
                                                                                     
                                                                                     
     *note assertIsNotNone(x): 1493.               ‘x is not None’                   3.1
                                                                                     
                                                                                     
     *note assertIn(a, b): 154c.                   ‘a in b’                          3.1
                                                                                     
                                                                                     
     *note assertNotIn(a, b): 154d.                ‘a not in b’                      3.1
                                                                                     
                                                                                     
     *note assertIsInstance(a, b): 1545.           ‘isinstance(a, b)’                3.2
                                                                                     
                                                                                     
     *note assertNotIsInstance(a, b): 1546.        ‘not isinstance(a, b)’            3.2
                                                                                     
                                                                                     
     *note assertIsSubclass(a, b): 2b6.            ‘issubclass(a, b)’                3.14
                                                                                     
                                                                                     
     *note assertNotIsSubclass(a, b): 2b7.         ‘not issubclass(a, b)’            3.14
                                                                                     

     All the assert methods accept a 'msg' argument that, if specified,
     is used as the error message on failure (see also *note
     longMessage: 153d.).  Note that the 'msg' keyword argument can be
     passed to *note assertRaises(): 751, *note assertRaisesRegex():
     753, *note assertWarns(): 136c, *note assertWarnsRegex(): 136d.
     only when they are used as a context manager.

      -- Metodo: assertEqual (first, second, msg=None)

          Test that 'first' and 'second' are equal.  If the values do
          not compare equal, the test will fail.

          In addition, if 'first' and 'second' are the exact same type
          and one of list, tuple, dict, set, frozenset or str or any
          type that a subclass registers with *note
          addTypeEqualityFunc(): 1550. the type-specific equality
          function will be called in order to generate a more useful
          default error message (see also the *note list of
          type-specific methods: 45db.).

          Cambiato nella versione 3.1: Added the automatic calling of
          type-specific equality function.

          Cambiato nella versione 3.2: *note assertMultiLineEqual():
          154b. added as the default type equality function for
          comparing strings.

      -- Metodo: assertNotEqual (first, second, msg=None)

          Test that 'first' and 'second' are not equal.  If the values
          do compare equal, the test will fail.

      -- Metodo: assertTrue (expr, msg=None)
      -- Metodo: assertFalse (expr, msg=None)

          Test that 'expr' is true (or false).

          Note that this is equivalent to ‘bool(expr) is True’ and not
          to ‘expr is True’ (use ‘assertIs(expr, True)’ for the latter).
          This method should also be avoided when more specific methods
          are available (e.g.  ‘assertEqual(a, b)’ instead of
          ‘assertTrue(a == b)’), because they provide a better error
          message in case of failure.

      -- Metodo: assertIs (first, second, msg=None)
      -- Metodo: assertIsNot (first, second, msg=None)

          Test that 'first' and 'second' are (or are not) the same
          object.

          Added in version 3.1.

      -- Metodo: assertIsNone (expr, msg=None)
      -- Metodo: assertIsNotNone (expr, msg=None)

          Test that 'expr' is (or is not) ‘None’.

          Added in version 3.1.

      -- Metodo: assertIn (member, container, msg=None)
      -- Metodo: assertNotIn (member, container, msg=None)

          Test that 'member' is (or is not) in 'container'.

          Added in version 3.1.

      -- Metodo: assertIsInstance (obj, cls, msg=None)
      -- Metodo: assertNotIsInstance (obj, cls, msg=None)

          Test that 'obj' is (or is not) an instance of 'cls' (which can
          be a class or a tuple of classes, as supported by *note
          isinstance(): 2ad.).  To check for the exact type, use *note
          assertIs(type(obj), cls): 1543.

          Added in version 3.2.

      -- Metodo: assertIsSubclass (cls, superclass, msg=None)
      -- Metodo: assertNotIsSubclass (cls, superclass, msg=None)

          Test that 'cls' is (or is not) a subclass of 'superclass'
          (which can be a class or a tuple of classes, as supported by
          *note issubclass(): 9c6.).  To check for the exact type, use
          *note assertIs(cls, superclass): 1543.

          Added in version 3.14.

     It is also possible to check the production of exceptions,
     warnings, and log messages using the following methods:

     Method                                                        Checks that                                New in
                                                                                                              
     --------------------------------------------------------------------------------------------------------------------------
                                                                                                              
     *note assertRaises(exc, fun, *args, **kwds): 751.             ‘fun(*args, **kwds)’ raises 'exc'
                                                                   
                                                                                                              
     *note assertRaisesRegex(exc, r, fun, *args, **kwds): 753.     ‘fun(*args, **kwds)’ raises 'exc' and      3.1
                                                                   the message matches regex 'r'              
                                                                   
                                                                                                              
     *note assertWarns(warn, fun, *args, **kwds): 136c.            ‘fun(*args, **kwds)’ raises 'warn'         3.2
                                                                                                              
                                                                                                              
     *note assertWarnsRegex(warn, r, fun, *args, **kwds): 136d.    ‘fun(*args, **kwds)’ raises 'warn' and     3.2
                                                                   the message matches regex 'r'              
                                                                   
                                                                                                              
     *note assertLogs(logger, level): a5b.                         The ‘with’ block logs on 'logger' with     3.4
                                                                   minimum 'level'                            
                                                                   
                                                                                                              
     *note assertNoLogs(logger, level): a5a.                       The ‘with’ block does not log on           3.10
                                                                                                              
                                                                        'logger' with minimum 'level'
                                                                   

      -- Metodo: assertRaises (exception, callable, *args, **kwds)

      -- Metodo: assertRaises (exception, *, msg=None)

          Test that an exception is raised when 'callable' is called
          with any positional or keyword arguments that are also passed
          to *note assertRaises(): 751.  The test passes if 'exception'
          is raised, is an error if another exception is raised, or
          fails if no exception is raised.  To catch any of a group of
          exceptions, a tuple containing the exception classes may be
          passed as 'exception'.

          If only the 'exception' and possibly the 'msg' arguments are
          given, return a context manager so that the code under test
          can be written inline rather than as a function:

               with self.assertRaises(SomeException):
                   do_something()

          When used as a context manager, *note assertRaises(): 751.
          accepts the additional keyword argument 'msg'.

          The context manager will store the caught exception object in
          its ‘exception’ attribute.  This can be useful if the
          intention is to perform additional checks on the exception
          raised:

               with self.assertRaises(SomeException) as cm:
                   do_something()

               the_exception = cm.exception
               self.assertEqual(the_exception.error_code, 3)

          Cambiato nella versione 3.1: Added the ability to use *note
          assertRaises(): 751. as a context manager.

          Cambiato nella versione 3.2: Added the ‘exception’ attribute.

          Cambiato nella versione 3.3: Added the 'msg' keyword argument
          when used as a context manager.

      -- Metodo: assertRaisesRegex (exception, regex, callable, *args,
               **kwds)

      -- Metodo: assertRaisesRegex (exception, regex, *, msg=None)

          Like *note assertRaises(): 751. but also tests that 'regex'
          matches on the string representation of the raised exception.
          'regex' may be a regular expression object or a string
          containing a regular expression suitable for use by *note
          re.search(): 1434.  Examples:

               self.assertRaisesRegex(ValueError, "invalid literal for.*XYZ'$",
                                      int, 'XYZ')

          or:

               with self.assertRaisesRegex(ValueError, 'literal'):
                  int('XYZ')

          Added in version 3.1: Added under the name
          ‘assertRaisesRegexp’.

          Cambiato nella versione 3.2: Renamed to *note
          assertRaisesRegex(): 753.

          Cambiato nella versione 3.3: Added the 'msg' keyword argument
          when used as a context manager.

      -- Metodo: assertWarns (warning, callable, *args, **kwds)

      -- Metodo: assertWarns (warning, *, msg=None)

          Test that a warning is triggered when 'callable' is called
          with any positional or keyword arguments that are also passed
          to *note assertWarns(): 136c.  The test passes if 'warning' is
          triggered and fails if it isn’t.  Any exception is an error.
          To catch any of a group of warnings, a tuple containing the
          warning classes may be passed as 'warnings'.

          If only the 'warning' and possibly the 'msg' arguments are
          given, return a context manager so that the code under test
          can be written inline rather than as a function:

               with self.assertWarns(SomeWarning):
                   do_something()

          When used as a context manager, *note assertWarns(): 136c.
          accepts the additional keyword argument 'msg'.

          The context manager will store the caught warning object in
          its ‘warning’ attribute, and the source line which triggered
          the warnings in the ‘filename’ and ‘lineno’ attributes.  This
          can be useful if the intention is to perform additional checks
          on the warning caught:

               with self.assertWarns(SomeWarning) as cm:
                   do_something()

               self.assertIn('myfile.py', cm.filename)
               self.assertEqual(320, cm.lineno)

          This method works regardless of the warning filters in place
          when it is called.

          Added in version 3.2.

          Cambiato nella versione 3.3: Added the 'msg' keyword argument
          when used as a context manager.

      -- Metodo: assertWarnsRegex (warning, regex, callable, *args,
               **kwds)

      -- Metodo: assertWarnsRegex (warning, regex, *, msg=None)

          Like *note assertWarns(): 136c. but also tests that 'regex'
          matches on the message of the triggered warning.  'regex' may
          be a regular expression object or a string containing a
          regular expression suitable for use by *note re.search():
          1434.  Example:

               self.assertWarnsRegex(DeprecationWarning,
                                     r'legacy_function\(\) is deprecated',
                                     legacy_function, 'XYZ')

          or:

               with self.assertWarnsRegex(RuntimeWarning, 'unsafe frobnicating'):
                   frobnicate('/etc/passwd')

          Added in version 3.2.

          Cambiato nella versione 3.3: Added the 'msg' keyword argument
          when used as a context manager.

      -- Metodo: assertLogs (logger=None, level=None)

          A context manager to test that at least one message is logged
          on the 'logger' or one of its children, with at least the
          given 'level'.

          If given, 'logger' should be a *note logging.Logger: d48.
          object or a *note str: 169. giving the name of a logger.  The
          default is the root logger, which will catch all messages that
          were not blocked by a non-propagating descendent logger.

          If given, 'level' should be either a numeric logging level or
          its string equivalent (for example either ‘"ERROR"’ or *note
          logging.ERROR: 20ca.).  The default is *note logging.INFO:
          20c8.

          The test passes if at least one message emitted inside the
          ‘with’ block matches the 'logger' and 'level' conditions,
          otherwise it fails.

          The object returned by the context manager is a recording
          helper which keeps tracks of the matching log messages.  It
          has two attributes:

           -- Attributo: records

               A list of *note logging.LogRecord: 11e8. objects of the
               matching log messages.

           -- Attributo: output

               A list of *note str: 169. objects with the formatted
               output of matching messages.

          Example:

               with self.assertLogs('foo', level='INFO') as cm:
                   logging.getLogger('foo').info('first message')
                   logging.getLogger('foo.bar').error('second message')
               self.assertEqual(cm.output, ['INFO:foo:first message',
                                            'ERROR:foo.bar:second message'])

          Added in version 3.4.

      -- Metodo: assertNoLogs (logger=None, level=None)

          A context manager to test that no messages are logged on the
          'logger' or one of its children, with at least the given
          'level'.

          If given, 'logger' should be a *note logging.Logger: d48.
          object or a *note str: 169. giving the name of a logger.  The
          default is the root logger, which will catch all messages.

          If given, 'level' should be either a numeric logging level or
          its string equivalent (for example either ‘"ERROR"’ or *note
          logging.ERROR: 20ca.).  The default is *note logging.INFO:
          20c8.

          Unlike *note assertLogs(): a5b, nothing will be returned by
          the context manager.

          Added in version 3.10.

     There are also other methods used to perform more specific checks,
     such as:

     Method                                      Checks that                          New in
                                                                                      
     ----------------------------------------------------------------------------------------------------
                                                                                      
     *note assertAlmostEqual(a, b): 74f.         ‘round(a-b, 7) == 0’
                                                 
                                                                                      
     *note assertNotAlmostEqual(a, b): 750.      ‘round(a-b, 7) != 0’
                                                 
                                                                                      
     *note assertGreater(a, b): 1547.            ‘a > b’                              3.1
                                                                                      
                                                                                      
     *note assertGreaterEqual(a, b): 1548.       ‘a >= b’                             3.1
                                                                                      
                                                                                      
     *note assertLess(a, b): 1549.               ‘a < b’                              3.1
                                                                                      
                                                                                      
     *note assertLessEqual(a, b): 154a.          ‘a <= b’                             3.1
                                                                                      
                                                                                      
     *note assertRegex(s, r): 752.               ‘r.search(s)’                        3.1
                                                                                      
                                                                                      
     *note assertNotRegex(s, r): 754.            ‘not r.search(s)’                    3.2
                                                                                      
                                                                                      
     *note assertCountEqual(a, b): 1432.         'a' and 'b' have the same elements   3.2
                                                 in the same number, regardless of    
                                                 their order.
                                                 
                                                                                      
     *note assertStartsWith(a, b): 2b8.          ‘a.startswith(b)’                    3.14
                                                                                      
                                                                                      
     *note assertNotStartsWith(a, b): 2b9.       ‘not a.startswith(b)’                3.14
                                                                                      
                                                                                      
     *note assertEndsWith(a, b): 2ba.            ‘a.endswith(b)’                      3.14
                                                                                      
                                                                                      
     *note assertNotEndsWith(a, b): 2bb.         ‘not a.endswith(b)’                  3.14
                                                                                      
                                                                                      
     *note assertHasAttr(a, b): 2b4.             ‘hastattr(a, b)’                     3.14
                                                                                      
                                                                                      
     *note assertNotHasAttr(a, b): 2b5.          ‘not hastattr(a, b)’                 3.14
                                                                                      

      -- Metodo: assertAlmostEqual (first, second, places=7, msg=None,
               delta=None)
      -- Metodo: assertNotAlmostEqual (first, second, places=7,
               msg=None, delta=None)

          Test that 'first' and 'second' are approximately (or not
          approximately) equal by computing the difference, rounding to
          the given number of decimal 'places' (default 7), and
          comparing to zero.  Note that these methods round the values
          to the given number of 'decimal places' (i.e.  like the *note
          round(): 14e2. function) and not 'significant digits'.

          If 'delta' is supplied instead of 'places' then the difference
          between 'first' and 'second' must be less or equal to (or
          greater than) 'delta'.

          Supplying both 'delta' and 'places' raises a *note TypeError:
          198.

          Cambiato nella versione 3.2: *note assertAlmostEqual(): 74f.
          automatically considers almost equal objects that compare
          equal.  *note assertNotAlmostEqual(): 750. automatically fails
          if the objects compare equal.  Added the 'delta' keyword
          argument.

      -- Metodo: assertGreater (first, second, msg=None)
      -- Metodo: assertGreaterEqual (first, second, msg=None)
      -- Metodo: assertLess (first, second, msg=None)
      -- Metodo: assertLessEqual (first, second, msg=None)

          Test that 'first' is respectively >, >=, < or <= than 'second'
          depending on the method name.  If not, the test will fail:

               >>> self.assertGreaterEqual(3, 4)
               AssertionError: "3" unexpectedly not greater than or equal to "4"

          Added in version 3.1.

      -- Metodo: assertRegex (text, regex, msg=None)
      -- Metodo: assertNotRegex (text, regex, msg=None)

          Test that a 'regex' search matches (or does not match) 'text'.
          In case of failure, the error message will include the pattern
          and the 'text' (or the pattern and the part of 'text' that
          unexpectedly matched).  'regex' may be a regular expression
          object or a string containing a regular expression suitable
          for use by *note re.search(): 1434.

          Added in version 3.1: Added under the name
          ‘assertRegexpMatches’.

          Cambiato nella versione 3.2: The method
          ‘assertRegexpMatches()’ has been renamed to *note
          assertRegex(): 752.

          Added in version 3.2: *note assertNotRegex(): 754.

      -- Metodo: assertCountEqual (first, second, msg=None)

          Test that sequence 'first' contains the same elements as
          'second', regardless of their order.  When they don’t, an
          error message listing the differences between the sequences
          will be generated.

          Duplicate elements are 'not' ignored when comparing 'first'
          and 'second'.  It verifies whether each element has the same
          count in both sequences.  Equivalent to:
          ‘assertEqual(Counter(list(first)), Counter(list(second)))’ but
          works with sequences of unhashable objects as well.

          Added in version 3.2.

      -- Metodo: assertStartsWith (s, prefix, msg=None)

      -- Metodo: assertNotStartsWith (s, prefix, msg=None)

          Test that the Unicode or byte string 's' starts (or does not
          start) with a 'prefix'.  'prefix' can also be a tuple of
          strings to try.

          Added in version 3.14.

      -- Metodo: assertEndsWith (s, suffix, msg=None)

      -- Metodo: assertNotEndsWith (s, suffix, msg=None)

          Test that the Unicode or byte string 's' ends (or does not
          end) with a 'suffix'.  'suffix' can also be a tuple of strings
          to try.

          Added in version 3.14.

      -- Metodo: assertHasAttr (obj, name, msg=None)

      -- Metodo: assertNotHasAttr (obj, name, msg=None)

          Test that the object 'obj' has (or has not) an attribute
          'name'.

          Added in version 3.14.

     The *note assertEqual(): 74d. method dispatches the equality check
     for objects of the same type to different type-specific methods.
     These methods are already implemented for most of the built-in
     types, but it’s also possible to register new methods using *note
     addTypeEqualityFunc(): 1550.:

      -- Metodo: addTypeEqualityFunc (typeobj, function)

          Registers a type-specific method called by *note
          assertEqual(): 74d. to check if two objects of exactly the
          same 'typeobj' (not subclasses) compare equal.  'function'
          must take two positional arguments and a third msg=None
          keyword argument just as *note assertEqual(): 74d. does.  It
          must raise *note self.failureException(msg): 4572. when
          inequality between the first two parameters is detected –
          possibly providing useful information and explaining the
          inequalities in details in the error message.

          Added in version 3.1.

     The list of type-specific methods automatically used by *note
     assertEqual(): 74d. are summarized in the following table.  Note
     that it’s usually not necessary to invoke these methods directly.

     Method                                        Used to compare                   New in
                                                                                     
     ---------------------------------------------------------------------------------------------------
                                                                                     
     *note assertMultiLineEqual(a, b): 154b.       strings                           3.1
                                                                                     
                                                                                     
     *note assertSequenceEqual(a, b): 1491.        sequences                         3.1
                                                                                     
                                                                                     
     *note assertListEqual(a, b): 148f.            lists                             3.1
                                                                                     
                                                                                     
     *note assertTupleEqual(a, b): 1490.           tuples                            3.1
                                                                                     
                                                                                     
     *note assertSetEqual(a, b): 148d.             sets or frozensets                3.1
                                                                                     
                                                                                     
     *note assertDictEqual(a, b): 148e.            dicts                             3.1
                                                                                     

      -- Metodo: assertMultiLineEqual (first, second, msg=None)

          Test that the multiline string 'first' is equal to the string
          'second'.  When not equal a diff of the two strings
          highlighting the differences will be included in the error
          message.  This method is used by default when comparing
          strings with *note assertEqual(): 74d.

          Added in version 3.1.

      -- Metodo: assertSequenceEqual (first, second, msg=None,
               seq_type=None)

          Tests that two sequences are equal.  If a 'seq_type' is
          supplied, both 'first' and 'second' must be instances of
          'seq_type' or a failure will be raised.  If the sequences are
          different an error message is constructed that shows the
          difference between the two.

          This method is not called directly by *note assertEqual():
          74d, but it’s used to implement *note assertListEqual(): 148f.
          and *note assertTupleEqual(): 1490.

          Added in version 3.1.

      -- Metodo: assertListEqual (first, second, msg=None)
      -- Metodo: assertTupleEqual (first, second, msg=None)

          Tests that two lists or tuples are equal.  If not, an error
          message is constructed that shows only the differences between
          the two.  An error is also raised if either of the parameters
          are of the wrong type.  These methods are used by default when
          comparing lists or tuples with *note assertEqual(): 74d.

          Added in version 3.1.

      -- Metodo: assertSetEqual (first, second, msg=None)

          Tests that two sets are equal.  If not, an error message is
          constructed that lists the differences between the sets.  This
          method is used by default when comparing sets or frozensets
          with *note assertEqual(): 74d.

          Fails if either of 'first' or 'second' does not have a *note
          difference(): 267c. method.

          Added in version 3.1.

      -- Metodo: assertDictEqual (first, second, msg=None)

          Test that two dictionaries are equal.  If not, an error
          message is constructed that shows the differences in the
          dictionaries.  This method will be used by default to compare
          dictionaries in calls to *note assertEqual(): 74d.

          Added in version 3.1.

     Finally the *note TestCase: 2b3. provides the following methods and
     attributes:

      -- Metodo: fail (msg=None)

          Signals a test failure unconditionally, with 'msg' or ‘None’
          for the error message.

      -- Attributo: failureException

          This class attribute gives the exception raised by the test
          method.  If a test framework needs to use a specialized
          exception, possibly to carry additional information, it must
          subclass this exception in order to «play fair» with the
          framework.  The initial value of this attribute is *note
          AssertionError: 8b9.

      -- Attributo: longMessage

          This class attribute determines what happens when a custom
          failure message is passed as the msg argument to an assertXYY
          call that fails.  ‘True’ is the default value.  In this case,
          the custom message is appended to the end of the standard
          failure message.  When set to ‘False’, the custom message
          replaces the standard message.

          The class setting can be overridden in individual test methods
          by assigning an instance attribute, self.longMessage, to
          ‘True’ or ‘False’ before calling the assert methods.

          The class setting gets reset before each test call.

          Added in version 3.1.

      -- Attributo: maxDiff

          This attribute controls the maximum length of diffs output by
          assert methods that report diffs on failure.  It defaults to
          80*8 characters.  Assert methods affected by this attribute
          are *note assertSequenceEqual(): 1491. (including all the
          sequence comparison methods that delegate to it), *note
          assertDictEqual(): 148e. and *note assertMultiLineEqual():
          154b.

          Setting ‘maxDiff’ to ‘None’ means that there is no maximum
          length of diffs.

          Added in version 3.2.

     Testing frameworks can use the following methods to collect
     information on the test:

      -- Metodo: countTestCases ()

          Return the number of tests represented by this test object.
          For *note TestCase: 2b3. instances, this will always be ‘1’.

      -- Metodo: defaultTestResult ()

          Return an instance of the test result class that should be
          used for this test case class (if no other result instance is
          provided to the *note run(): 136e. method).

          For *note TestCase: 2b3. instances, this will always be an
          instance of *note TestResult: 136f.; subclasses of *note
          TestCase: 2b3. should override this as necessary.

      -- Metodo: id ()

          Return a string identifying the specific test case.  This is
          usually the full name of the test method, including the module
          and class name.

      -- Metodo: shortDescription ()

          Returns a description of the test, or ‘None’ if no description
          has been provided.  The default implementation of this method
          returns the first line of the test method’s docstring, if
          available, or ‘None’.

          Cambiato nella versione 3.1: In 3.1 this was changed to add
          the test name to the short description even in the presence of
          a docstring.  This caused compatibility issues with unittest
          extensions and adding the test name was moved to the *note
          TextTestResult: 755. in Python 3.2.

      -- Metodo: addCleanup (function, /, *args, **kwargs)

          Add a function to be called after *note tearDown(): 1542. to
          cleanup resources used during the test.  Functions will be
          called in reverse order to the order they are added (LIFO).
          They are called with any arguments and keyword arguments
          passed into *note addCleanup(): c76. when they are added.

          If *note setUp(): 1541. fails, meaning that *note tearDown():
          1542. is not called, then any cleanup functions added will
          still be called.

          Added in version 3.1.

      -- Metodo: enterContext (cm)

          Enter the supplied *note context manager: 1e1.  If successful,
          also add its *note __exit__(): 1508. method as a cleanup
          function by *note addCleanup(): c76. and return the result of
          the *note __enter__(): 7e5. method.

          Added in version 3.11.

      -- Metodo: doCleanups ()

          This method is called unconditionally after *note tearDown():
          1542, or after *note setUp(): 1541. if *note setUp(): 1541.
          raises an exception.

          It is responsible for calling all the cleanup functions added
          by *note addCleanup(): c76.  If you need cleanup functions to
          be called 'prior' to *note tearDown(): 1542. then you can call
          *note doCleanups(): 1540. yourself.

          *note doCleanups(): 1540. pops methods off the stack of
          cleanup functions one at a time, so it can be called at any
          time.

          Added in version 3.1.

      -- Metodo: classmethod addClassCleanup (function, /, *args,
               **kwargs)

          Add a function to be called after *note tearDownClass(): 153f.
          to cleanup resources used during the test class.  Functions
          will be called in reverse order to the order they are added
          (LIFO).  They are called with any arguments and keyword
          arguments passed into *note addClassCleanup(): c43. when they
          are added.

          If *note setUpClass(): c45. fails, meaning that *note
          tearDownClass(): 153f. is not called, then any cleanup
          functions added will still be called.

          Added in version 3.8.

      -- Metodo: classmethod enterClassContext (cm)

          Enter the supplied *note context manager: 1e1.  If successful,
          also add its *note __exit__(): 1508. method as a cleanup
          function by *note addClassCleanup(): c43. and return the
          result of the *note __enter__(): 7e5. method.

          Added in version 3.11.

      -- Metodo: classmethod doClassCleanups ()

          This method is called unconditionally after *note
          tearDownClass(): 153f, or after *note setUpClass(): c45. if
          *note setUpClass(): c45. raises an exception.

          It is responsible for calling all the cleanup functions added
          by *note addClassCleanup(): c43.  If you need cleanup
          functions to be called 'prior' to *note tearDownClass(): 153f.
          then you can call *note doClassCleanups(): 45e3. yourself.

          *note doClassCleanups(): 45e3. pops methods off the stack of
          cleanup functions one at a time, so it can be called at any
          time.

          Added in version 3.8.

 -- Classe: unittest.IsolatedAsyncioTestCase (methodName='runTest')

     This class provides an API similar to *note TestCase: 2b3. and also
     accepts coroutines as test functions.

     Added in version 3.8.

      -- Attributo: loop_factory

          The 'loop_factory' passed to *note asyncio.Runner: 2f5.
          Override in subclasses with *note asyncio.EventLoop: 1a4f. to
          avoid using the asyncio policy system.

          Added in version 3.13.

      -- Metodo: async asyncSetUp ()

          Method called to prepare the test fixture.  This is called
          after *note TestCase.setUp(): 1541.  This is called
          immediately before calling the test method; other than *note
          AssertionError: 8b9. or *note SkipTest: 11e6, any exception
          raised by this method will be considered an error rather than
          a test failure.  The default implementation does nothing.

      -- Metodo: async asyncTearDown ()

          Method called immediately after the test method has been
          called and the result recorded.  This is called before *note
          tearDown(): 1542.  This is called even if the test method
          raised an exception, so the implementation in subclasses may
          need to be particularly careful about checking internal state.
          Any exception, other than *note AssertionError: 8b9. or *note
          SkipTest: 11e6, raised by this method will be considered an
          additional error rather than a test failure (thus increasing
          the total number of reported errors).  This method will only
          be called if the *note asyncSetUp(): 45e5. succeeds,
          regardless of the outcome of the test method.  The default
          implementation does nothing.

      -- Metodo: addAsyncCleanup (function, /, *args, **kwargs)

          This method accepts a coroutine that can be used as a cleanup
          function.

      -- Metodo: async enterAsyncContext (cm)

          Enter the supplied *note asynchronous context manager: 7f1.
          If successful, also add its *note __aexit__(): 1989. method as
          a cleanup function by *note addAsyncCleanup(): 45e7. and
          return the result of the *note __aenter__(): 2401. method.

          Added in version 3.11.

      -- Metodo: run (result=None)

          Sets up a new event loop to run the test, collecting the
          result into the *note TestResult: 136f. object passed as
          'result'.  If 'result' is omitted or ‘None’, a temporary
          result object is created (by calling the *note
          defaultTestResult(): 45da. method) and used.  The result
          object is returned to *note run(): 45e8.”s caller.  At the end
          of the test all the tasks in the event loop are cancelled.

     An example illustrating the order:

          from unittest import IsolatedAsyncioTestCase

          events = []


          class Test(IsolatedAsyncioTestCase):


              def setUp(self):
                  events.append("setUp")

              async def asyncSetUp(self):
                  self._async_connection = await AsyncConnection()
                  events.append("asyncSetUp")

              async def test_response(self):
                  events.append("test_response")
                  response = await self._async_connection.get("https://example.com")
                  self.assertEqual(response.status_code, 200)
                  self.addAsyncCleanup(self.on_cleanup)

              def tearDown(self):
                  events.append("tearDown")

              async def asyncTearDown(self):
                  await self._async_connection.close()
                  events.append("asyncTearDown")

              async def on_cleanup(self):
                  events.append("cleanup")

          if __name__ == "__main__":
              unittest.main()

     After running the test, ‘events’ would contain ‘["setUp",
     "asyncSetUp", "test_response", "asyncTearDown", "tearDown",
     "cleanup"]’.

 -- Classe: unittest.FunctionTestCase (testFunc, setUp=None,
          tearDown=None, description=None)

     This class implements the portion of the *note TestCase: 2b3.
     interface which allows the test runner to drive the test, but does
     not provide the methods which test code can use to check and report
     errors.  This is used to create test cases using legacy test code,
     allowing it to be integrated into a *note unittest: 10c.-based test
     framework.


File: python.info,  Node: Grouping tests,  Next: Loading and running tests,  Prev: Test cases,  Up: Classes and functions

5.26.5.11 Grouping tests
........................

 -- Classe: unittest.TestSuite (tests=())

     This class represents an aggregation of individual test cases and
     test suites.  The class presents the interface needed by the test
     runner to allow it to be run as any other test case.  Running a
     *note TestSuite: ff7. instance is the same as iterating over the
     suite, running each test individually.

     If 'tests' is given, it must be an iterable of individual test
     cases or other test suites that will be used to build the suite
     initially.  Additional methods are provided to add test cases and
     suites to the collection later on.

     *note TestSuite: ff7. objects behave much like *note TestCase: 2b3.
     objects, except they do not actually implement a test.  Instead,
     they are used to aggregate tests into groups of tests that should
     be run together.  Some additional methods are available to add
     tests to *note TestSuite: ff7. instances:

      -- Metodo: addTest (test)

          Add a *note TestCase: 2b3. or *note TestSuite: ff7. to the
          suite.

      -- Metodo: addTests (tests)

          Add all the tests from an iterable of *note TestCase: 2b3. and
          *note TestSuite: ff7. instances to this test suite.

          This is equivalent to iterating over 'tests', calling *note
          addTest(): 45eb. for each element.

     *note TestSuite: ff7. shares the following methods with *note
     TestCase: 2b3.:

      -- Metodo: run (result)

          Run the tests associated with this suite, collecting the
          result into the test result object passed as 'result'.  Note
          that unlike *note TestCase.run(): 136e, *note TestSuite.run():
          45ed. requires the result object to be passed in.

      -- Metodo: debug ()

          Run the tests associated with this suite without collecting
          the result.  This allows exceptions raised by the test to be
          propagated to the caller and can be used to support running
          tests under a debugger.

      -- Metodo: countTestCases ()

          Return the number of tests represented by this test object,
          including all individual tests and sub-suites.

      -- Metodo: __iter__ ()

          Tests grouped by a *note TestSuite: ff7. are always accessed
          by iteration.  Subclasses can lazily provide tests by
          overriding ‘__iter__()’.  Note that this method may be called
          several times on a single suite (for example when counting
          tests or comparing for equality) so the tests returned by
          repeated iterations before *note TestSuite.run(): 45ed. must
          be the same for each call iteration.  After *note
          TestSuite.run(): 45ed, callers should not rely on the tests
          returned by this method unless the caller uses a subclass that
          overrides ‘TestSuite._removeTestAtIndex()’ to preserve test
          references.

          Cambiato nella versione 3.2: In earlier versions the *note
          TestSuite: ff7. accessed tests directly rather than through
          iteration, so overriding ‘__iter__()’ wasn’t sufficient for
          providing tests.

          Cambiato nella versione 3.4: In earlier versions the *note
          TestSuite: ff7. held references to each *note TestCase: 2b3.
          after *note TestSuite.run(): 45ed.  Subclasses can restore
          that behavior by overriding ‘TestSuite._removeTestAtIndex()’.

     In the typical usage of a *note TestSuite: ff7. object, the *note
     run(): 45ed. method is invoked by a ‘TestRunner’ rather than by the
     end-user test harness.


File: python.info,  Node: Loading and running tests,  Prev: Grouping tests,  Up: Classes and functions

5.26.5.12 Loading and running tests
...................................

 -- Classe: unittest.TestLoader

     The *note TestLoader: 593. class is used to create test suites from
     classes and modules.  Normally, there is no need to create an
     instance of this class; the *note unittest: 10c. module provides an
     instance that can be shared as *note unittest.defaultTestLoader:
     45f1.  Using a subclass or instance, however, allows customization
     of some configurable properties.

     *note TestLoader: 593. objects have the following attributes:

      -- Attributo: errors

          A list of the non-fatal errors encountered while loading
          tests.  Not reset by the loader at any point.  Fatal errors
          are signalled by the relevant method raising an exception to
          the caller.  Non-fatal errors are also indicated by a
          synthetic test that will raise the original error when run.

          Added in version 3.5.

     *note TestLoader: 593. objects have the following methods:

      -- Metodo: loadTestsFromTestCase (testCaseClass)

          Return a suite of all test cases contained in the *note
          TestCase: 2b3.-derived ‘testCaseClass’.

          A test case instance is created for each method named by *note
          getTestCaseNames(): 596.  By default these are the method
          names beginning with ‘test’.  If *note getTestCaseNames():
          596. returns no methods, but the ‘runTest()’ method is
          implemented, a single test case is created for that method
          instead.

      -- Metodo: loadTestsFromModule (module, *, pattern=None)

          Return a suite of all test cases contained in the given
          module.  This method searches 'module' for classes derived
          from *note TestCase: 2b3. and creates an instance of the class
          for each test method defined for the class.

               Nota: While using a hierarchy of *note TestCase:
               2b3.-derived classes can be convenient in sharing
               fixtures and helper functions, defining test methods on
               base classes that are not intended to be instantiated
               directly does not play well with this method.  Doing so,
               however, can be useful when the fixtures are different
               and defined in subclasses.

          If a module provides a ‘load_tests’ function it will be called
          to load the tests.  This allows modules to customize test
          loading.  This is the *note load_tests protocol: 45ca.  The
          'pattern' argument is passed as the third argument to
          ‘load_tests’.

          Cambiato nella versione 3.2: Support for ‘load_tests’ added.

          Cambiato nella versione 3.5: Support for a keyword-only
          argument 'pattern' has been added.

          Cambiato nella versione 3.12: The undocumented and unofficial
          'use_load_tests' parameter has been removed.

      -- Metodo: loadTestsFromName (name, module=None)

          Return a suite of all test cases given a string specifier.

          The specifier 'name' is a «dotted name» that may resolve
          either to a module, a test case class, a test method within a
          test case class, a *note TestSuite: ff7. instance, or a
          callable object which returns a *note TestCase: 2b3. or *note
          TestSuite: ff7. instance.  These checks are applied in the
          order listed here; that is, a method on a possible test case
          class will be picked up as «a test method within a test case
          class», rather than «a callable object».

          For example, if you have a module ‘SampleTests’ containing a
          *note TestCase: 2b3.-derived class ‘SampleTestCase’ with three
          test methods (‘test_one()’, ‘test_two()’, and ‘test_three()’),
          the specifier ‘'SampleTests.SampleTestCase'’ would cause this
          method to return a suite which will run all three test
          methods.  Using the specifier
          ‘'SampleTests.SampleTestCase.test_two'’ would cause it to
          return a test suite which will run only the ‘test_two()’ test
          method.  The specifier can refer to modules and packages which
          have not been imported; they will be imported as a
          side-effect.

          The method optionally resolves 'name' relative to the given
          'module'.

          Cambiato nella versione 3.5: If an *note ImportError: 65b. or
          *note AttributeError: 5f0. occurs while traversing 'name' then
          a synthetic test that raises that error when run will be
          returned.  These errors are included in the errors accumulated
          by self.errors.

      -- Metodo: loadTestsFromNames (names, module=None)

          Similar to *note loadTestsFromName(): 154e, but takes a
          sequence of names rather than a single name.  The return value
          is a test suite which supports all the tests defined for each
          name.

      -- Metodo: getTestCaseNames (testCaseClass)

          Return a sorted sequence of method names found within
          'testCaseClass'; this should be a subclass of *note TestCase:
          2b3.

      -- Metodo: discover (start_dir, pattern='test*.py',
               top_level_dir=None)

          Find all the test modules by recursing into subdirectories
          from the specified start directory, and return a TestSuite
          object containing them.  Only test files that match 'pattern'
          will be loaded.  (Using shell style pattern matching.)  Only
          module names that are importable (i.e.  are valid Python
          identifiers) will be loaded.

          All test modules must be importable from the top level of the
          project.  If the start directory is not the top level
          directory then 'top_level_dir' must be specified separately.

          If importing a module fails, for example due to a syntax
          error, then this will be recorded as a single error and
          discovery will continue.  If the import failure is due to
          *note SkipTest: 11e6. being raised, it will be recorded as a
          skip instead of an error.

          If a package (a directory containing a file named
          ‘__init__.py’) is found, the package will be checked for a
          ‘load_tests’ function.  If this exists then it will be called
          ‘package.load_tests(loader, tests, pattern)’.  Test discovery
          takes care to ensure that a package is only checked for tests
          once during an invocation, even if the load_tests function
          itself calls ‘loader.discover’.

          If ‘load_tests’ exists then discovery does 'not' recurse into
          the package, ‘load_tests’ is responsible for loading all tests
          in the package.

          The pattern is deliberately not stored as a loader attribute
          so that packages can continue discovery themselves.

          'top_level_dir' is stored internally, and used as a default to
          any nested calls to ‘discover()’.  That is, if a package’s
          ‘load_tests’ calls ‘loader.discover()’, it does not need to
          pass this argument.

          'start_dir' can be a dotted module name as well as a
          directory.

          Added in version 3.2.

          Cambiato nella versione 3.4: Modules that raise *note
          SkipTest: 11e6. on import are recorded as skips, not errors.

          'start_dir' can be a *note namespace packages: 2b2.

          Paths are sorted before being imported so that execution order
          is the same even if the underlying file system’s ordering is
          not dependent on file name.

          Cambiato nella versione 3.5: Found packages are now checked
          for ‘load_tests’ regardless of whether their path matches
          'pattern', because it is impossible for a package name to
          match the default pattern.

          Cambiato nella versione 3.11: 'start_dir' can not be a *note
          namespace packages: 2b2.  It has been broken since Python 3.7,
          and Python 3.11 officially removes it.

          Cambiato nella versione 3.13: 'top_level_dir' is only stored
          for the duration of 'discover' call.

          Cambiato nella versione 3.14: 'start_dir' can once again be a
          *note namespace package: 2b2.

     The following attributes of a *note TestLoader: 593. can be
     configured either by subclassing or assignment on an instance:

      -- Attributo: testMethodPrefix

          String giving the prefix of method names which will be
          interpreted as test methods.  The default value is ‘'test'’.

          This affects *note getTestCaseNames(): 596. and all the
          ‘loadTestsFrom*’ methods.

      -- Attributo: sortTestMethodsUsing

          Function to be used to compare method names when sorting them
          in *note getTestCaseNames(): 596. and all the ‘loadTestsFrom*’
          methods.

      -- Attributo: suiteClass

          Callable object that constructs a test suite from a list of
          tests.  No methods on the resulting object are needed.  The
          default value is the *note TestSuite: ff7. class.

          This affects all the ‘loadTestsFrom*’ methods.

      -- Attributo: testNamePatterns

          List of Unix shell-style wildcard test name patterns that test
          methods have to match to be included in test suites (see ‘-k’
          option).

          If this attribute is not ‘None’ (the default), all test
          methods to be included in test suites must match one of the
          patterns in this list.  Note that matches are always performed
          using *note fnmatch.fnmatchcase(): 1c3d, so unlike patterns
          passed to the ‘-k’ option, simple substring patterns will have
          to be converted using ‘*’ wildcards.

          This affects all the ‘loadTestsFrom*’ methods.

          Added in version 3.7.

 -- Classe: unittest.TestResult

     This class is used to compile information about which tests have
     succeeded and which have failed.

     A *note TestResult: 136f. object stores the results of a set of
     tests.  The *note TestCase: 2b3. and *note TestSuite: ff7. classes
     ensure that results are properly recorded; test authors do not need
     to worry about recording the outcome of tests.

     Testing frameworks built on top of *note unittest: 10c. may want
     access to the *note TestResult: 136f. object generated by running a
     set of tests for reporting purposes; a *note TestResult: 136f.
     instance is returned by the ‘TestRunner.run()’ method for this
     purpose.

     *note TestResult: 136f. instances have the following attributes
     that will be of interest when inspecting the results of running a
     set of tests:

      -- Attributo: errors

          A list containing 2-tuples of *note TestCase: 2b3. instances
          and strings holding formatted tracebacks.  Each tuple
          represents a test which raised an unexpected exception.

      -- Attributo: failures

          A list containing 2-tuples of *note TestCase: 2b3. instances
          and strings holding formatted tracebacks.  Each tuple
          represents a test where a failure was explicitly signalled
          using the *note assert* methods: 45b2.

      -- Attributo: skipped

          A list containing 2-tuples of *note TestCase: 2b3. instances
          and strings holding the reason for skipping the test.

          Added in version 3.1.

      -- Attributo: expectedFailures

          A list containing 2-tuples of *note TestCase: 2b3. instances
          and strings holding formatted tracebacks.  Each tuple
          represents an expected failure or error of the test case.

      -- Attributo: unexpectedSuccesses

          A list containing *note TestCase: 2b3. instances that were
          marked as expected failures, but succeeded.

      -- Attributo: collectedDurations

          A list containing 2-tuples of test case names and floats
          representing the elapsed time of each test which was run.

          Added in version 3.12.

      -- Attributo: shouldStop

          Set to ‘True’ when the execution of tests should stop by *note
          stop(): 45fc.

      -- Attributo: testsRun

          The total number of tests run so far.

      -- Attributo: buffer

          If set to true, ‘sys.stdout’ and ‘sys.stderr’ will be buffered
          in between *note startTest(): 45ff. and *note stopTest():
          4600. being called.  Collected output will only be echoed onto
          the real ‘sys.stdout’ and ‘sys.stderr’ if the test fails or
          errors.  Any output is also attached to the failure / error
          message.

          Added in version 3.2.

      -- Attributo: failfast

          If set to true *note stop(): 45fc. will be called on the first
          failure or error, halting the test run.

          Added in version 3.2.

      -- Attributo: tb_locals

          If set to true then local variables will be shown in
          tracebacks.

          Added in version 3.5.

      -- Metodo: wasSuccessful ()

          Return ‘True’ if all tests run so far have passed, otherwise
          returns ‘False’.

          Cambiato nella versione 3.4: Returns ‘False’ if there were any
          *note unexpectedSuccesses: 45fa. from tests marked with the
          *note expectedFailure(): 45d1. decorator.

      -- Metodo: stop ()

          This method can be called to signal that the set of tests
          being run should be aborted by setting the *note shouldStop:
          45fb. attribute to ‘True’.  ‘TestRunner’ objects should
          respect this flag and return without running any additional
          tests.

          For example, this feature is used by the *note TextTestRunner:
          1a9e. class to stop the test framework when the user signals
          an interrupt from the keyboard.  Interactive tools which
          provide ‘TestRunner’ implementations can use this in a similar
          manner.

     The following methods of the *note TestResult: 136f. class are used
     to maintain the internal data structures, and may be extended in
     subclasses to support additional reporting requirements.  This is
     particularly useful in building tools which support interactive
     reporting while tests are being run.

      -- Metodo: startTest (test)

          Called when the test case 'test' is about to be run.

      -- Metodo: stopTest (test)

          Called after the test case 'test' has been executed,
          regardless of the outcome.

      -- Metodo: startTestRun ()

          Called once before any tests are executed.

          Added in version 3.1.

      -- Metodo: stopTestRun ()

          Called once after all tests are executed.

          Added in version 3.1.

      -- Metodo: addError (test, err)

          Called when the test case 'test' raises an unexpected
          exception.  'err' is a tuple of the form returned by *note
          sys.exc_info(): 89b.: ‘(type, value, traceback)’.

          The default implementation appends a tuple ‘(test,
          formatted_err)’ to the instance’s *note errors: 45f6.
          attribute, where 'formatted_err' is a formatted traceback
          derived from 'err'.

      -- Metodo: addFailure (test, err)

          Called when the test case 'test' signals a failure.  'err' is
          a tuple of the form returned by *note sys.exc_info(): 89b.:
          ‘(type, value, traceback)’.

          The default implementation appends a tuple ‘(test,
          formatted_err)’ to the instance’s *note failures: 45f7.
          attribute, where 'formatted_err' is a formatted traceback
          derived from 'err'.

      -- Metodo: addSuccess (test)

          Called when the test case 'test' succeeds.

          The default implementation does nothing.

      -- Metodo: addSkip (test, reason)

          Called when the test case 'test' is skipped.  'reason' is the
          reason the test gave for skipping.

          The default implementation appends a tuple ‘(test, reason)’ to
          the instance’s *note skipped: 45f8. attribute.

      -- Metodo: addExpectedFailure (test, err)

          Called when the test case 'test' fails or errors, but was
          marked with the *note expectedFailure(): 45d1. decorator.

          The default implementation appends a tuple ‘(test,
          formatted_err)’ to the instance’s *note expectedFailures:
          45f9. attribute, where 'formatted_err' is a formatted
          traceback derived from 'err'.

      -- Metodo: addUnexpectedSuccess (test)

          Called when the test case 'test' was marked with the *note
          expectedFailure(): 45d1. decorator, but succeeded.

          The default implementation appends the test to the instance’s
          *note unexpectedSuccesses: 45fa. attribute.

      -- Metodo: addSubTest (test, subtest, outcome)

          Called when a subtest finishes.  'test' is the test case
          corresponding to the test method.  'subtest' is a custom *note
          TestCase: 2b3. instance describing the subtest.

          If 'outcome' is *note None: 886, the subtest succeeded.
          Otherwise, it failed with an exception where 'outcome' is a
          tuple of the form returned by *note sys.exc_info(): 89b.:
          ‘(type, value, traceback)’.

          The default implementation does nothing when the outcome is a
          success, and records subtest failures as normal failures.

          Added in version 3.4.

      -- Metodo: addDuration (test, elapsed)

          Called when the test case finishes.  'elapsed' is the time
          represented in seconds, and it includes the execution of
          cleanup functions.

          Added in version 3.12.

 -- Classe: unittest.TextTestResult (stream, descriptions, verbosity, *,
          durations=None)

     A concrete implementation of *note TestResult: 136f. used by the
     *note TextTestRunner: 1a9e.  Subclasses should accept ‘**kwargs’ to
     ensure compatibility as the interface changes.

     Added in version 3.2.

     Cambiato nella versione 3.12: Added the 'durations' keyword
     parameter.

 -- Dati: unittest.defaultTestLoader

     Instance of the *note TestLoader: 593. class intended to be shared.
     If no customization of the *note TestLoader: 593. is needed, this
     instance can be used instead of repeatedly creating new instances.

 -- Classe: unittest.TextTestRunner (stream=None, descriptions=True,
          verbosity=1, failfast=False, buffer=False, resultclass=None,
          warnings=None, *, tb_locals=False, durations=None)

     A basic test runner implementation that outputs results to a
     stream.  If 'stream' is ‘None’, the default, *note sys.stderr: b35.
     is used as the output stream.  This class has a few configurable
     parameters, but is essentially very simple.  Graphical applications
     which run test suites should provide alternate implementations.
     Such implementations should accept ‘**kwargs’ as the interface to
     construct runners changes when features are added to unittest.

     By default this runner shows *note DeprecationWarning: 1a3, *note
     PendingDeprecationWarning: ac8, *note ResourceWarning: 54d. and
     *note ImportWarning: 71f. even if they are *note ignored by
     default: 4607.  This behavior can be overridden using Python’s
     ‘-Wd’ or ‘-Wa’ options (see *note Warning control: 2112.) and
     leaving 'warnings' to ‘None’.

     Cambiato nella versione 3.2: Added the 'warnings' parameter.

     Cambiato nella versione 3.2: The default stream is set to *note
     sys.stderr: b35. at instantiation time rather than import time.

     Cambiato nella versione 3.5: Added the 'tb_locals' parameter.

     Cambiato nella versione 3.12: Added the 'durations' parameter.

      -- Metodo: _makeResult ()

          This method returns the instance of ‘TestResult’ used by *note
          run(): 4609.  It is not intended to be called directly, but
          can be overridden in subclasses to provide a custom
          ‘TestResult’.

          ‘_makeResult()’ instantiates the class or callable passed in
          the ‘TextTestRunner’ constructor as the ‘resultclass’
          argument.  It defaults to *note TextTestResult: 755. if no
          ‘resultclass’ is provided.  The result class is instantiated
          with the following arguments:

               stream, descriptions, verbosity

      -- Metodo: run (test)

          This method is the main public interface to the
          ‘TextTestRunner’.  This method takes a *note TestSuite: ff7.
          or *note TestCase: 2b3. instance.  A *note TestResult: 136f.
          is created by calling *note _makeResult(): 4608. and the
          test(s) are run and the results printed to stdout.

 -- Funzione: unittest.main (module='__main__', defaultTest=None,
          argv=None, testRunner=None,
          testLoader=unittest.defaultTestLoader, exit=True, verbosity=1,
          failfast=None, catchbreak=None, buffer=None, warnings=None)

     A command-line program that loads a set of tests from 'module' and
     runs them; this is primarily for making test modules conveniently
     executable.  The simplest use for this function is to include the
     following line at the end of a test script:

          if __name__ == '__main__':
              unittest.main()

     You can run tests with more detailed information by passing in the
     verbosity argument:

          if __name__ == '__main__':
              unittest.main(verbosity=2)

     The 'defaultTest' argument is either the name of a single test or
     an iterable of test names to run if no test names are specified via
     'argv'.  If not specified or ‘None’ and no test names are provided
     via 'argv', all tests found in 'module' are run.

     The 'argv' argument can be a list of options passed to the program,
     with the first element being the program name.  If not specified or
     ‘None’, the values of *note sys.argv: 146c. are used.

     The 'testRunner' argument can either be a test runner class or an
     already created instance of it.  By default ‘main’ calls *note
     sys.exit(): 277. with an exit code indicating success (0) or
     failure (1) of the tests run.  An exit code of 5 indicates that no
     tests were run or skipped.

     The 'testLoader' argument has to be a *note TestLoader: 593.
     instance, and defaults to *note defaultTestLoader: 45f1.

     ‘main’ supports being used from the interactive interpreter by
     passing in the argument ‘exit=False’.  This displays the result on
     standard output without calling *note sys.exit(): 277.:

          >>> from unittest import main
          >>> main(module='test_module', exit=False)

     The 'failfast', 'catchbreak' and 'buffer' parameters have the same
     effect as the same-name *note command-line options: 45b9.

     The 'warnings' argument specifies the *note warning filter: 1b1.
     that should be used while running the tests.  If it’s not
     specified, it will remain ‘None’ if a ‘-W’ option is passed to
     ‘python’ (see *note Warning control: 2112.), otherwise it will be
     set to ‘'default'’.

     Calling ‘main’ returns an object with the ‘result’ attribute that
     contains the result of the tests run as a *note
     unittest.TestResult: 136f.

     Cambiato nella versione 3.1: The 'exit' parameter was added.

     Cambiato nella versione 3.2: The 'verbosity', 'failfast',
     'catchbreak', 'buffer' and 'warnings' parameters were added.

     Cambiato nella versione 3.4: The 'defaultTest' parameter was
     changed to also accept an iterable of test names.

* Menu:

* load_tests Protocol::


File: python.info,  Node: load_tests Protocol,  Up: Loading and running tests

5.26.5.13 load_tests Protocol
.............................

Added in version 3.2.

Modules or packages can customize how tests are loaded from them during
normal test runs or test discovery by implementing a function called
‘load_tests’.

If a test module defines ‘load_tests’ it will be called by *note
TestLoader.loadTestsFromModule(): 594. with the following arguments:

     load_tests(loader, standard_tests, pattern)

where 'pattern' is passed straight through from ‘loadTestsFromModule’.
It defaults to ‘None’.

It should return a *note TestSuite: ff7.

'loader' is the instance of *note TestLoader: 593. doing the loading.
'standard_tests' are the tests that would be loaded by default from the
module.  It is common for test modules to only want to add or remove
tests from the standard set of tests.  The third argument is used when
loading packages as part of test discovery.

A typical ‘load_tests’ function that loads tests from a specific set of
*note TestCase: 2b3. classes may look like:

     test_cases = (TestCase1, TestCase2, TestCase3)

     def load_tests(loader, tests, pattern):
         suite = TestSuite()
         for test_class in test_cases:
             tests = loader.loadTestsFromTestCase(test_class)
             suite.addTests(tests)
         return suite

If discovery is started in a directory containing a package, either from
the command line or by calling *note TestLoader.discover(): 11e7, then
the package ‘__init__.py’ will be checked for ‘load_tests’.  If that
function does not exist, discovery will recurse into the package as
though it were just another directory.  Otherwise, discovery of the
package’s tests will be left up to ‘load_tests’ which is called with the
following arguments:

     load_tests(loader, standard_tests, pattern)

This should return a *note TestSuite: ff7. representing all the tests
from the package.  (‘standard_tests’ will only contain tests collected
from ‘__init__.py’.)

Because the pattern is passed into ‘load_tests’ the package is free to
continue (and potentially modify) test discovery.  A “do nothing”
‘load_tests’ function for a test package would look like:

     def load_tests(loader, standard_tests, pattern):
         # top level directory cached on loader instance
         this_dir = os.path.dirname(__file__)
         package_tests = loader.discover(start_dir=this_dir, pattern=pattern)
         standard_tests.addTests(package_tests)
         return standard_tests

Cambiato nella versione 3.5: Discovery no longer checks package names
for matching 'pattern' due to the impossibility of package names
matching the default pattern.


File: python.info,  Node: Class and Module Fixtures,  Next: Signal Handling,  Prev: Classes and functions,  Up: unittest — Unit testing framework

5.26.5.14 Class and Module Fixtures
...................................

Class and module level fixtures are implemented in *note TestSuite: ff7.
When the test suite encounters a test from a new class then *note
tearDownClass(): 153f. from the previous class (if there is one) is
called, followed by *note setUpClass(): c45. from the new class.

Similarly if a test is from a different module from the previous test
then ‘tearDownModule’ from the previous module is run, followed by
‘setUpModule’ from the new module.

After all the tests have run the final ‘tearDownClass’ and
‘tearDownModule’ are run.

Note that shared fixtures do not play well with [potential] features
like test parallelization and they break test isolation.  They should be
used with care.

The default ordering of tests created by the unittest test loaders is to
group all tests from the same modules and classes together.  This will
lead to ‘setUpClass’ / ‘setUpModule’ (etc) being called exactly once per
class and module.  If you randomize the order, so that tests from
different modules and classes are adjacent to each other, then these
shared fixture functions may be called multiple times in a single test
run.

Shared fixtures are not intended to work with suites with non-standard
ordering.  A ‘BaseTestSuite’ still exists for frameworks that don’t want
to support shared fixtures.

If there are any exceptions raised during one of the shared fixture
functions the test is reported as an error.  Because there is no
corresponding test instance an ‘_ErrorHolder’ object (that has the same
interface as a *note TestCase: 2b3.) is created to represent the error.
If you are just using the standard unittest test runner then this detail
doesn’t matter, but if you are a framework author it may be relevant.

* Menu:

* setUpClass and tearDownClass::
* setUpModule and tearDownModule::


File: python.info,  Node: setUpClass and tearDownClass,  Next: setUpModule and tearDownModule,  Up: Class and Module Fixtures

5.26.5.15 setUpClass and tearDownClass
......................................

These must be implemented as class methods:

     import unittest

     class Test(unittest.TestCase):
         @classmethod
         def setUpClass(cls):
             cls._connection = createExpensiveConnectionObject()

         @classmethod
         def tearDownClass(cls):
             cls._connection.destroy()

If you want the ‘setUpClass’ and ‘tearDownClass’ on base classes called
then you must call up to them yourself.  The implementations in *note
TestCase: 2b3. are empty.

If an exception is raised during a ‘setUpClass’ then the tests in the
class are not run and the ‘tearDownClass’ is not run.  Skipped classes
will not have ‘setUpClass’ or ‘tearDownClass’ run.  If the exception is
a *note SkipTest: 11e6. exception then the class will be reported as
having been skipped instead of as an error.


File: python.info,  Node: setUpModule and tearDownModule,  Prev: setUpClass and tearDownClass,  Up: Class and Module Fixtures

5.26.5.16 setUpModule and tearDownModule
........................................

These should be implemented as functions:

     def setUpModule():
         createConnection()

     def tearDownModule():
         closeConnection()

If an exception is raised in a ‘setUpModule’ then none of the tests in
the module will be run and the ‘tearDownModule’ will not be run.  If the
exception is a *note SkipTest: 11e6. exception then the module will be
reported as having been skipped instead of as an error.

To add cleanup code that must be run even in the case of an exception,
use ‘addModuleCleanup’:

 -- Funzione: unittest.addModuleCleanup (function, /, *args, **kwargs)

     Add a function to be called after *note tearDownModule(): 153e. to
     cleanup resources used during the test class.  Functions will be
     called in reverse order to the order they are added (LIFO).  They
     are called with any arguments and keyword arguments passed into
     *note addModuleCleanup(): c42. when they are added.

     If *note setUpModule(): c44. fails, meaning that *note
     tearDownModule(): 153e. is not called, then any cleanup functions
     added will still be called.

     Added in version 3.8.

 -- Funzione: unittest.enterModuleContext (cm)

     Enter the supplied *note context manager: 1e1.  If successful, also
     add its *note __exit__(): 1508. method as a cleanup function by
     *note addModuleCleanup(): c42. and return the result of the *note
     __enter__(): 7e5. method.

     Added in version 3.11.

 -- Funzione: unittest.doModuleCleanups ()

     This function is called unconditionally after *note
     tearDownModule(): 153e, or after *note setUpModule(): c44. if *note
     setUpModule(): c44. raises an exception.

     It is responsible for calling all the cleanup functions added by
     *note addModuleCleanup(): c42.  If you need cleanup functions to be
     called 'prior' to *note tearDownModule(): 153e. then you can call
     *note doModuleCleanups(): 1bbb. yourself.

     *note doModuleCleanups(): 1bbb. pops methods off the stack of
     cleanup functions one at a time, so it can be called at any time.

     Added in version 3.8.


File: python.info,  Node: Signal Handling,  Prev: Class and Module Fixtures,  Up: unittest — Unit testing framework

5.26.5.17 Signal Handling
.........................

Added in version 3.2.

The *note -c/-catch: 153a. command-line option to unittest, along with
the ‘catchbreak’ parameter to *note unittest.main(): 11e5, provide more
friendly handling of control-C during a test run.  With catch break
behavior enabled control-C will allow the currently running test to
complete, and the test run will then end and report all the results so
far.  A second control-c will raise a *note KeyboardInterrupt: bc7. in
the usual way.

The control-c handling signal handler attempts to remain compatible with
code or tests that install their own *note signal.SIGINT: 253. handler.
If the ‘unittest’ handler is called but 'isn’t' the installed *note
signal.SIGINT: 253. handler, i.e.  it has been replaced by the system
under test and delegated to, then it calls the default handler.  This
will normally be the expected behavior by code that replaces an
installed handler and delegates to it.  For individual tests that need
‘unittest’ control-c handling disabled the *note removeHandler(): 153b.
decorator can be used.

There are a few utility functions for framework authors to enable
control-c handling functionality within test frameworks.

 -- Funzione: unittest.installHandler ()

     Install the control-c handler.  When a *note signal.SIGINT: 253. is
     received (usually in response to the user pressing control-c) all
     registered results have *note stop(): 45fc. called.

 -- Funzione: unittest.registerResult (result)

     Register a *note TestResult: 136f. object for control-c handling.
     Registering a result stores a weak reference to it, so it doesn’t
     prevent the result from being garbage collected.

     Registering a *note TestResult: 136f. object has no side-effects if
     control-c handling is not enabled, so test frameworks can
     unconditionally register all results they create independently of
     whether or not handling is enabled.

 -- Funzione: unittest.removeResult (result)

     Remove a registered result.  Once a result has been removed then
     *note stop(): 45fc. will no longer be called on that result object
     in response to a control-c.

 -- Funzione: unittest.removeHandler (function=None)

     When called without arguments this function removes the control-c
     handler if it has been installed.  This function can also be used
     as a test decorator to temporarily remove the handler while the
     test is being executed:

          @unittest.removeHandler
          def test_signal_handling(self):
              ...


File: python.info,  Node: unittest mock — mock object library,  Next: unittest mock — getting started,  Prev: unittest — Unit testing framework,  Up: Development Tools

5.26.6 ‘unittest.mock’ — mock object library
--------------------------------------------

Added in version 3.3.

'Source code:' Lib/unittest/mock.py(1)

__________________________________________________________________

*note unittest.mock: 10d. is a library for testing in Python.  It allows
you to replace parts of your system under test with mock objects and
make assertions about how they have been used.

*note unittest.mock: 10d. provides a core *note Mock: c41. class
removing the need to create a host of stubs throughout your test suite.
After performing an action, you can make assertions about which methods
/ attributes were used and arguments they were called with.  You can
also specify return values and set needed attributes in the normal way.

Additionally, mock provides a *note patch(): 1094. decorator that
handles patching module and class level attributes within the scope of a
test, along with *note sentinel: d9b. for creating unique objects.  See
the *note quick guide: 4612. for some examples of how to use *note Mock:
c41, *note MagicMock: 1091. and *note patch(): 1094.

Mock is designed for use with *note unittest: 10c. and is based on the
“action -> assertion” pattern instead of “record -> replay” used by many
mocking frameworks.

There is a backport of *note unittest.mock: 10d. for earlier versions of
Python, available as mock(2) on PyPI.

* Menu:

* Quick Guide::
* The Mock Class::
* The patchers::
* MagicMock and magic method support::
* Helpers::
* Order of precedence of side_effect, return_value and wraps: Order of precedence of side_effect return_value and wraps.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/unittest/mock.py

   (2) https://pypi.org/project/mock/


File: python.info,  Node: Quick Guide,  Next: The Mock Class,  Up: unittest mock — mock object library

5.26.6.1 Quick Guide
....................

*note Mock: c41. and *note MagicMock: 1091. objects create all
attributes and methods as you access them and store details of how they
have been used.  You can configure them, to specify return values or
limit what attributes are available, and then make assertions about how
they have been used:

     >>> from unittest.mock import MagicMock
     >>> thing = ProductionClass()
     >>> thing.method = MagicMock(return_value=3)
     >>> thing.method(3, 4, 5, key='value')
     3
     >>> thing.method.assert_called_with(3, 4, 5, key='value')

*note side_effect: 4613. allows you to perform side effects, including
raising an exception when a mock is called:

     >>> from unittest.mock import Mock
     >>> mock = Mock(side_effect=KeyError('foo'))
     >>> mock()
     Traceback (most recent call last):
      ...
     KeyError: 'foo'

     >>> values = {'a': 1, 'b': 2, 'c': 3}
     >>> def side_effect(arg):
     ...     return values[arg]
     ...
     >>> mock.side_effect = side_effect
     >>> mock('a'), mock('b'), mock('c')
     (1, 2, 3)
     >>> mock.side_effect = [5, 4, 3, 2, 1]
     >>> mock(), mock(), mock()
     (5, 4, 3)

Mock has many other ways you can configure it and control its behaviour.
For example the 'spec' argument configures the mock to take its
specification from another object.  Attempting to access attributes or
methods on the mock that don’t exist on the spec will fail with an *note
AttributeError: 5f0.

The *note patch(): 1094. decorator / context manager makes it easy to
mock classes or objects in a module under test.  The object you specify
will be replaced with a mock (or other object) during the test and
restored when the test ends:

     >>> from unittest.mock import patch
     >>> @patch('module.ClassName2')
     ... @patch('module.ClassName1')
     ... def test(MockClass1, MockClass2):
     ...     module.ClassName1()
     ...     module.ClassName2()
     ...     assert MockClass1 is module.ClassName1
     ...     assert MockClass2 is module.ClassName2
     ...     assert MockClass1.called
     ...     assert MockClass2.called
     ...
     >>> test()

     Nota: When you nest patch decorators the mocks are passed in to the
     decorated function in the same order they applied (the normal
     'Python' order that decorators are applied).  This means from the
     bottom up, so in the example above the mock for ‘module.ClassName1’
     is passed in first.

     With *note patch(): 1094. it matters that you patch objects in the
     namespace where they are looked up.  This is normally
     straightforward, but for a quick guide read *note where to patch:
     4614.

As well as a decorator *note patch(): 1094. can be used as a context
manager in a with statement:

     >>> with patch.object(ProductionClass, 'method', return_value=None) as mock_method:
     ...     thing = ProductionClass()
     ...     thing.method(1, 2, 3)
     ...
     >>> mock_method.assert_called_once_with(1, 2, 3)

There is also *note patch.dict(): 194f. for setting values in a
dictionary just during a scope and restoring the dictionary to its
original state when the test ends:

     >>> foo = {'key': 'value'}
     >>> original = foo.copy()
     >>> with patch.dict(foo, {'newkey': 'newvalue'}, clear=True):
     ...     assert foo == {'newkey': 'newvalue'}
     ...
     >>> assert foo == original

Mock supports the mocking of Python *note magic methods: 4615.  The
easiest way of using magic methods is with the *note MagicMock: 1091.
class.  It allows you to do things like:

     >>> mock = MagicMock()
     >>> mock.__str__.return_value = 'foobarbaz'
     >>> str(mock)
     'foobarbaz'
     >>> mock.__str__.assert_called_with()

Mock allows you to assign functions (or other Mock instances) to magic
methods and they will be called appropriately.  The *note MagicMock:
1091. class is just a Mock variant that has all of the magic methods
pre-created for you (well, all the useful ones anyway).

The following is an example of using magic methods with the ordinary
Mock class:

     >>> mock = Mock()
     >>> mock.__str__ = Mock(return_value='wheeeeee')
     >>> str(mock)
     'wheeeeee'

For ensuring that the mock objects in your tests have the same api as
the objects they are replacing, you can use *note auto-speccing: 4616.
Auto-speccing can be done through the 'autospec' argument to patch, or
the *note create_autospec(): 191c. function.  Auto-speccing creates mock
objects that have the same attributes and methods as the objects they
are replacing, and any functions and methods (including constructors)
have the same call signature as the real object.

This ensures that your mocks will fail in the same way as your
production code if they are used incorrectly:

     >>> from unittest.mock import create_autospec
     >>> def function(a, b, c):
     ...     pass
     ...
     >>> mock_function = create_autospec(function, return_value='fishy')
     >>> mock_function(1, 2, 3)
     'fishy'
     >>> mock_function.assert_called_once_with(1, 2, 3)
     >>> mock_function('wrong arguments')
     Traceback (most recent call last):
      ...
     TypeError: missing a required argument: 'b'

*note create_autospec(): 191c. can also be used on classes, where it
copies the signature of the ‘__init__’ method, and on callable objects
where it copies the signature of the ‘__call__’ method.


File: python.info,  Node: The Mock Class,  Next: The patchers,  Prev: Quick Guide,  Up: unittest mock — mock object library

5.26.6.2 The Mock Class
.......................

*note Mock: c41. is a flexible mock object intended to replace the use
of stubs and test doubles throughout your code.  Mocks are callable and
create attributes as new mocks when you access them (1).  Accessing the
same attribute will always return the same mock.  Mocks record how you
use them, allowing you to make assertions about what your code has done
to them.

*note MagicMock: 1091. is a subclass of *note Mock: c41. with all the
magic methods pre-created and ready to use.  There are also non-callable
variants, useful when you are mocking out objects that aren’t callable:
*note NonCallableMock: 4618. and *note NonCallableMagicMock: 4619.

The *note patch(): 1094. decorators makes it easy to temporarily replace
classes in a particular module with a *note Mock: c41. object.  By
default *note patch(): 1094. will create a *note MagicMock: 1091. for
you.  You can specify an alternative class of *note Mock: c41. using the
'new_callable' argument to *note patch(): 1094.

 -- Classe: unittest.mock.Mock (spec=None, side_effect=None,
          return_value=DEFAULT, wraps=None, name=None, spec_set=None,
          unsafe=False, **kwargs)

     Create a new *note Mock: c41. object.  *note Mock: c41. takes
     several optional arguments that specify the behaviour of the Mock
     object:

        * 'spec': This can be either a list of strings or an existing
          object (a class or instance) that acts as the specification
          for the mock object.  If you pass in an object then a list of
          strings is formed by calling dir on the object (excluding
          unsupported magic attributes and methods).  Accessing any
          attribute not in this list will raise an *note AttributeError:
          5f0.

          If 'spec' is an object (rather than a list of strings) then
          *note __class__: 16b4. returns the class of the spec object.
          This allows mocks to pass *note isinstance(): 2ad. tests.

        * 'spec_set': A stricter variant of 'spec'.  If used, attempting
          to 'set' or get an attribute on the mock that isn’t on the
          object passed as 'spec_set' will raise an *note
          AttributeError: 5f0.

        * 'side_effect': A function to be called whenever the Mock is
          called.  See the *note side_effect: 4613. attribute.  Useful
          for raising exceptions or dynamically changing return values.
          The function is called with the same arguments as the mock,
          and unless it returns *note DEFAULT: 461a, the return value of
          this function is used as the return value.

          Alternatively 'side_effect' can be an exception class or
          instance.  In this case the exception will be raised when the
          mock is called.

          If 'side_effect' is an iterable then each call to the mock
          will return the next value from the iterable.

          A 'side_effect' can be cleared by setting it to ‘None’.

        * 'return_value': The value returned when the mock is called.
          By default this is a new Mock (created on first access).  See
          the *note return_value: 461b. attribute.

        * 'unsafe': By default, accessing any attribute whose name
          starts with 'assert', 'assret', 'asert', 'aseert' or 'assrt'
          will raise an *note AttributeError: 5f0.  Passing
          ‘unsafe=True’ will allow access to these attributes.

          Added in version 3.5.

        * 'wraps': Item for the mock object to wrap.  If 'wraps' is not
          ‘None’ then calling the Mock will pass the call through to the
          wrapped object (returning the real result).  Attribute access
          on the mock will return a Mock object that wraps the
          corresponding attribute of the wrapped object (so attempting
          to access an attribute that doesn’t exist will raise an *note
          AttributeError: 5f0.).

          If the mock has an explicit 'return_value' set then calls are
          not passed to the wrapped object and the 'return_value' is
          returned instead.

        * 'name': If the mock has a name then it will be used in the
          repr of the mock.  This can be useful for debugging.  The name
          is propagated to child mocks.

     Mocks can also be called with arbitrary keyword arguments.  These
     will be used to set attributes on the mock after it is created.
     See the *note configure_mock(): 461c. method for details.

      -- Metodo: assert_called ()

          Assert that the mock was called at least once.

               >>> mock = Mock()
               >>> mock.method()
               <Mock name='mock.method()' id='...'>
               >>> mock.method.assert_called()

          Added in version 3.6.

      -- Metodo: assert_called_once ()

          Assert that the mock was called exactly once.

               >>> mock = Mock()
               >>> mock.method()
               <Mock name='mock.method()' id='...'>
               >>> mock.method.assert_called_once()
               >>> mock.method()
               <Mock name='mock.method()' id='...'>
               >>> mock.method.assert_called_once()
               Traceback (most recent call last):
               ...
               AssertionError: Expected 'method' to have been called once. Called 2 times.
               Calls: [call(), call()].

          Added in version 3.6.

      -- Metodo: assert_called_with (*args, **kwargs)

          This method is a convenient way of asserting that the last
          call has been made in a particular way:

               >>> mock = Mock()
               >>> mock.method(1, 2, 3, test='wow')
               <Mock name='mock.method()' id='...'>
               >>> mock.method.assert_called_with(1, 2, 3, test='wow')

      -- Metodo: assert_called_once_with (*args, **kwargs)

          Assert that the mock was called exactly once and that call was
          with the specified arguments.

               >>> mock = Mock(return_value=None)
               >>> mock('foo', bar='baz')
               >>> mock.assert_called_once_with('foo', bar='baz')
               >>> mock('other', bar='values')
               >>> mock.assert_called_once_with('other', bar='values')
               Traceback (most recent call last):
                 ...
               AssertionError: Expected 'mock' to be called once. Called 2 times.
               Calls: [call('foo', bar='baz'), call('other', bar='values')].

      -- Metodo: assert_any_call (*args, **kwargs)

          assert the mock has been called with the specified arguments.

          The assert passes if the mock has 'ever' been called, unlike
          *note assert_called_with(): 1deb. and *note
          assert_called_once_with(): 461d. that only pass if the call is
          the most recent one, and in the case of *note
          assert_called_once_with(): 461d. it must also be the only
          call.

               >>> mock = Mock(return_value=None)
               >>> mock(1, 2, arg='thing')
               >>> mock('some', 'thing', 'else')
               >>> mock.assert_any_call(1, 2, arg='thing')

      -- Metodo: assert_has_calls (calls, any_order=False)

          assert the mock has been called with the specified calls.  The
          *note mock_calls: 461f. list is checked for the calls.

          If 'any_order' is false then the calls must be sequential.
          There can be extra calls before or after the specified calls.

          If 'any_order' is true then the calls can be in any order, but
          they must all appear in *note mock_calls: 461f.

               >>> mock = Mock(return_value=None)
               >>> mock(1)
               >>> mock(2)
               >>> mock(3)
               >>> mock(4)
               >>> calls = [call(2), call(3)]
               >>> mock.assert_has_calls(calls)
               >>> calls = [call(4), call(2), call(3)]
               >>> mock.assert_has_calls(calls, any_order=True)

      -- Metodo: assert_not_called ()

          Assert the mock was never called.

               >>> m = Mock()
               >>> m.hello.assert_not_called()
               >>> obj = m.hello()
               >>> m.hello.assert_not_called()
               Traceback (most recent call last):
                 ...
               AssertionError: Expected 'hello' to not have been called. Called 1 times.
               Calls: [call()].

          Added in version 3.5.

      -- Metodo: reset_mock (*, return_value=False, side_effect=False)

          The reset_mock method resets all the call attributes on a mock
          object:

               >>> mock = Mock(return_value=None)
               >>> mock('hello')
               >>> mock.called
               True
               >>> mock.reset_mock()
               >>> mock.called
               False

          This can be useful where you want to make a series of
          assertions that reuse the same object.

          'return_value' parameter when set to ‘True’ resets *note
          return_value: 461b.:

               >>> mock = Mock(return_value=5)
               >>> mock('hello')
               5
               >>> mock.reset_mock(return_value=True)
               >>> mock('hello')
               <Mock name='mock()' id='...'>

          'side_effect' parameter when set to ‘True’ resets *note
          side_effect: 4613.:

               >>> mock = Mock(side_effect=ValueError)
               >>> mock('hello')
               Traceback (most recent call last):
                 ...
               ValueError
               >>> mock.reset_mock(side_effect=True)
               >>> mock('hello')
               <Mock name='mock()' id='...'>

          Note that *note reset_mock(): ef8. 'doesn’t' clear the *note
          return_value: 461b, *note side_effect: 4613. or any child
          attributes you have set using normal assignment by default.

          Child mocks are reset as well.

          Cambiato nella versione 3.6: Added two keyword-only arguments
          to the reset_mock function.

      -- Metodo: mock_add_spec (spec, spec_set=False)

          Add a spec to a mock.  'spec' can either be an object or a
          list of strings.  Only attributes on the 'spec' can be fetched
          as attributes from the mock.

          If 'spec_set' is true then only attributes on the spec can be
          set.

      -- Metodo: attach_mock (mock, attribute)

          Attach a mock as an attribute of this one, replacing its name
          and parent.  Calls to the attached mock will be recorded in
          the *note method_calls: 4621. and *note mock_calls: 461f.
          attributes of this one.

      -- Metodo: configure_mock (**kwargs)

          Set attributes on the mock through keyword arguments.

          Attributes plus return values and side effects can be set on
          child mocks using standard dot notation and unpacking a
          dictionary in the method call:

               >>> mock = Mock()
               >>> attrs = {'method.return_value': 3, 'other.side_effect': KeyError}
               >>> mock.configure_mock(**attrs)
               >>> mock.method()
               3
               >>> mock.other()
               Traceback (most recent call last):
                 ...
               KeyError

          The same thing can be achieved in the constructor call to
          mocks:

               >>> attrs = {'method.return_value': 3, 'other.side_effect': KeyError}
               >>> mock = Mock(some_attribute='eggs', **attrs)
               >>> mock.some_attribute
               'eggs'
               >>> mock.method()
               3
               >>> mock.other()
               Traceback (most recent call last):
                 ...
               KeyError

          *note configure_mock(): 461c. exists to make it easier to do
          configuration after the mock has been created.

      -- Metodo: __dir__ ()

          *note Mock: c41. objects limit the results of ‘dir(some_mock)’
          to useful results.  For mocks with a 'spec' this includes all
          the permitted attributes for the mock.

          See *note FILTER_DIR: 4623. for what this filtering does, and
          how to switch it off.

      -- Metodo: _get_child_mock (**kw)

          Create the child mocks for attributes and return value.  By
          default child mocks will be the same type as the parent.
          Subclasses of Mock may want to override this to customize the
          way child mocks are made.

          For non-callable mocks the callable variant will be used
          (rather than any custom subclass).

      -- Attributo: called

          A boolean representing whether or not the mock object has been
          called:

               >>> mock = Mock(return_value=None)
               >>> mock.called
               False
               >>> mock()
               >>> mock.called
               True

      -- Attributo: call_count

          An integer telling you how many times the mock object has been
          called:

               >>> mock = Mock(return_value=None)
               >>> mock.call_count
               0
               >>> mock()
               >>> mock()
               >>> mock.call_count
               2

      -- Attributo: return_value

          Set this to configure the value returned by calling the mock:

               >>> mock = Mock()
               >>> mock.return_value = 'fish'
               >>> mock()
               'fish'

          The default return value is a mock object and you can
          configure it in the normal way:

               >>> mock = Mock()
               >>> mock.return_value.attribute = sentinel.Attribute
               >>> mock.return_value()
               <Mock name='mock()()' id='...'>
               >>> mock.return_value.assert_called_with()

          *note return_value: 461b. can also be set in the constructor:

               >>> mock = Mock(return_value=3)
               >>> mock.return_value
               3
               >>> mock()
               3

      -- Attributo: side_effect

          This can either be a function to be called when the mock is
          called, an iterable or an exception (class or instance) to be
          raised.

          If you pass in a function it will be called with same
          arguments as the mock and unless the function returns the
          *note DEFAULT: 461a. singleton the call to the mock will then
          return whatever the function returns.  If the function returns
          *note DEFAULT: 461a. then the mock will return its normal
          value (from the *note return_value: 461b.).

          If you pass in an iterable, it is used to retrieve an iterator
          which must yield a value on every call.  This value can either
          be an exception instance to be raised, or a value to be
          returned from the call to the mock (*note DEFAULT: 461a.
          handling is identical to the function case).

          An example of a mock that raises an exception (to test
          exception handling of an API):

               >>> mock = Mock()
               >>> mock.side_effect = Exception('Boom!')
               >>> mock()
               Traceback (most recent call last):
                 ...
               Exception: Boom!

          Using *note side_effect: 4613. to return a sequence of values:

               >>> mock = Mock()
               >>> mock.side_effect = [3, 2, 1]
               >>> mock(), mock(), mock()
               (3, 2, 1)

          Using a callable:

               >>> mock = Mock(return_value=3)
               >>> def side_effect(*args, **kwargs):
               ...     return DEFAULT
               ...
               >>> mock.side_effect = side_effect
               >>> mock()
               3

          *note side_effect: 4613. can be set in the constructor.
          Here’s an example that adds one to the value the mock is
          called with and returns it:

               >>> side_effect = lambda value: value + 1
               >>> mock = Mock(side_effect=side_effect)
               >>> mock(3)
               4
               >>> mock(-8)
               -7

          Setting *note side_effect: 4613. to ‘None’ clears it:

               >>> m = Mock(side_effect=KeyError, return_value=3)
               >>> m()
               Traceback (most recent call last):
                ...
               KeyError
               >>> m.side_effect = None
               >>> m()
               3

      -- Attributo: call_args

          This is either ‘None’ (if the mock hasn’t been called), or the
          arguments that the mock was last called with.  This will be in
          the form of a tuple: the first member, which can also be
          accessed through the ‘args’ property, is any positional
          arguments the mock was called with (or an empty tuple) and the
          second member, which can also be accessed through the ‘kwargs’
          property, is any keyword arguments (or an empty dictionary).

               >>> mock = Mock(return_value=None)
               >>> print(mock.call_args)
               None
               >>> mock()
               >>> mock.call_args
               call()
               >>> mock.call_args == ()
               True
               >>> mock(3, 4)
               >>> mock.call_args
               call(3, 4)
               >>> mock.call_args == ((3, 4),)
               True
               >>> mock.call_args.args
               (3, 4)
               >>> mock.call_args.kwargs
               {}
               >>> mock(3, 4, 5, key='fish', next='w00t!')
               >>> mock.call_args
               call(3, 4, 5, key='fish', next='w00t!')
               >>> mock.call_args.args
               (3, 4, 5)
               >>> mock.call_args.kwargs
               {'key': 'fish', 'next': 'w00t!'}

          *note call_args: 1d51, along with members of the lists *note
          call_args_list: 4626, *note method_calls: 4621. and *note
          mock_calls: 461f. are *note call: 1d9b. objects.  These are
          tuples, so they can be unpacked to get at the individual
          arguments and make more complex assertions.  See *note calls
          as tuples: 4627.

          Cambiato nella versione 3.8: Added ‘args’ and ‘kwargs’
          properties.

      -- Attributo: call_args_list

          This is a list of all the calls made to the mock object in
          sequence (so the length of the list is the number of times it
          has been called).  Before any calls have been made it is an
          empty list.  The *note call: 1d9b. object can be used for
          conveniently constructing lists of calls to compare with *note
          call_args_list: 4626.

               >>> mock = Mock(return_value=None)
               >>> mock()
               >>> mock(3, 4)
               >>> mock(key='fish', next='w00t!')
               >>> mock.call_args_list
               [call(), call(3, 4), call(key='fish', next='w00t!')]
               >>> expected = [(), ((3, 4),), ({'key': 'fish', 'next': 'w00t!'},)]
               >>> mock.call_args_list == expected
               True

          Members of *note call_args_list: 4626. are *note call: 1d9b.
          objects.  These can be unpacked as tuples to get at the
          individual arguments.  See *note calls as tuples: 4627.

      -- Attributo: method_calls

          As well as tracking calls to themselves, mocks also track
          calls to methods and attributes, and 'their' methods and
          attributes:

               >>> mock = Mock()
               >>> mock.method()
               <Mock name='mock.method()' id='...'>
               >>> mock.property.method.attribute()
               <Mock name='mock.property.method.attribute()' id='...'>
               >>> mock.method_calls
               [call.method(), call.property.method.attribute()]

          Members of *note method_calls: 4621. are *note call: 1d9b.
          objects.  These can be unpacked as tuples to get at the
          individual arguments.  See *note calls as tuples: 4627.

      -- Attributo: mock_calls

          *note mock_calls: 461f. records 'all' calls to the mock
          object, its methods, magic methods 'and' return value mocks.

               >>> mock = MagicMock()
               >>> result = mock(1, 2, 3)
               >>> mock.first(a=3)
               <MagicMock name='mock.first()' id='...'>
               >>> mock.second()
               <MagicMock name='mock.second()' id='...'>
               >>> int(mock)
               1
               >>> result(1)
               <MagicMock name='mock()()' id='...'>
               >>> expected = [call(1, 2, 3), call.first(a=3), call.second(),
               ... call.__int__(), call()(1)]
               >>> mock.mock_calls == expected
               True

          Members of *note mock_calls: 461f. are *note call: 1d9b.
          objects.  These can be unpacked as tuples to get at the
          individual arguments.  See *note calls as tuples: 4627.

               Nota: The way *note mock_calls: 461f. are recorded means
               that where nested calls are made, the parameters of
               ancestor calls are not recorded and so will always
               compare equal:

                    >>> mock = MagicMock()
                    >>> mock.top(a=3).bottom()
                    <MagicMock name='mock.top().bottom()' id='...'>
                    >>> mock.mock_calls
                    [call.top(a=3), call.top().bottom()]
                    >>> mock.mock_calls[-1] == call.top(a=-1).bottom()
                    True

      -- Attributo: __class__

          Normally the ‘__class__’ attribute of an object will return
          its type.  For a mock object with a ‘spec’, ‘__class__’
          returns the spec class instead.  This allows mock objects to
          pass *note isinstance(): 2ad. tests for the object they are
          replacing / masquerading as:

               >>> mock = Mock(spec=3)
               >>> isinstance(mock, int)
               True

          ‘__class__’ is assignable to, this allows a mock to pass an
          *note isinstance(): 2ad. check without forcing you to use a
          spec:

               >>> mock = Mock()
               >>> mock.__class__ = dict
               >>> isinstance(mock, dict)
               True

 -- Classe: unittest.mock.NonCallableMock (spec=None, wraps=None,
          name=None, spec_set=None, **kwargs)

     A non-callable version of *note Mock: c41.  The constructor
     parameters have the same meaning of *note Mock: c41, with the
     exception of 'return_value' and 'side_effect' which have no meaning
     on a non-callable mock.

Mock objects that use a class or an instance as a ‘spec’ or ‘spec_set’
are able to pass *note isinstance(): 2ad. tests:

     >>> mock = Mock(spec=SomeClass)
     >>> isinstance(mock, SomeClass)
     True
     >>> mock = Mock(spec_set=SomeClass())
     >>> isinstance(mock, SomeClass)
     True

The *note Mock: c41. classes have support for mocking magic methods.
See *note magic methods: 4615. for the full details.

The mock classes and the *note patch(): 1094. decorators all take
arbitrary keyword arguments for configuration.  For the *note patch():
1094. decorators the keywords are passed to the constructor of the mock
being created.  The keyword arguments are for configuring attributes of
the mock:

     >>> m = MagicMock(attribute=3, other='fish')
     >>> m.attribute
     3
     >>> m.other
     'fish'

The return value and side effect of child mocks can be set in the same
way, using dotted notation.  As you can’t use dotted names directly in a
call you have to create a dictionary and unpack it using ‘**’:

     >>> attrs = {'method.return_value': 3, 'other.side_effect': KeyError}
     >>> mock = Mock(some_attribute='eggs', **attrs)
     >>> mock.some_attribute
     'eggs'
     >>> mock.method()
     3
     >>> mock.other()
     Traceback (most recent call last):
       ...
     KeyError

A callable mock which was created with a 'spec' (or a 'spec_set') will
introspect the specification object’s signature when matching calls to
the mock.  Therefore, it can match the actual call’s arguments
regardless of whether they were passed positionally or by name:

     >>> def f(a, b, c): pass
     ...
     >>> mock = Mock(spec=f)
     >>> mock(1, 2, c=3)
     <Mock name='mock()' id='140161580456576'>
     >>> mock.assert_called_with(1, 2, 3)
     >>> mock.assert_called_with(a=1, b=2, c=3)

This applies to *note assert_called_with(): 1deb, *note
assert_called_once_with(): 461d, *note assert_has_calls(): 1a0a. and
*note assert_any_call(): 461e.  When *note Autospeccing: 4616, it will
also apply to method calls on the mock object.

Cambiato nella versione 3.4: Added signature introspection on specced
and autospecced mock objects.

 -- Classe: unittest.mock.PropertyMock (*args, **kwargs)

     A mock intended to be used as a *note property: 4b4, or other *note
     descriptor: 1869, on a class.  *note PropertyMock: 4629. provides
     *note __get__(): 16ef. and *note __set__(): 239b. methods so you
     can specify a return value when it is fetched.

     Fetching a *note PropertyMock: 4629. instance from an object calls
     the mock, with no args.  Setting it calls the mock with the value
     being set.

          >>> class Foo:
          ...     @property
          ...     def foo(self):
          ...         return 'something'
          ...     @foo.setter
          ...     def foo(self, value):
          ...         pass
          ...
          >>> with patch('__main__.Foo.foo', new_callable=PropertyMock) as mock_foo:
          ...     mock_foo.return_value = 'mockity-mock'
          ...     this_foo = Foo()
          ...     print(this_foo.foo)
          ...     this_foo.foo = 6
          ...
          mockity-mock
          >>> mock_foo.mock_calls
          [call(), call(6)]

Because of the way mock attributes are stored you can’t directly attach
a *note PropertyMock: 4629. to a mock object.  Instead you can attach it
to the mock type object:

     >>> m = MagicMock()
     >>> p = PropertyMock(return_value=3)
     >>> type(m).foo = p
     >>> m.foo
     3
     >>> p.assert_called_once_with()

     Attenzione: If an *note AttributeError: 5f0. is raised by *note
     PropertyMock: 4629, it will be interpreted as a missing descriptor
     and *note __getattr__(): 6fb. will be called on the parent mock:

          >>> m = MagicMock()
          >>> no_attribute = PropertyMock(side_effect=AttributeError)
          >>> type(m).my_property = no_attribute
          >>> m.my_property
          <MagicMock name='mock.my_property' id='140165240345424'>

     See *note __getattr__(): 6fb. for details.

 -- Classe: unittest.mock.AsyncMock (spec=None, side_effect=None,
          return_value=DEFAULT, wraps=None, name=None, spec_set=None,
          unsafe=False, **kwargs)

     An asynchronous version of *note MagicMock: 1091.  The *note
     AsyncMock: c40. object will behave so the object is recognized as
     an async function, and the result of a call is an awaitable.

          >>> mock = AsyncMock()
          >>> inspect.iscoroutinefunction(mock)
          True
          >>> inspect.isawaitable(mock())
          True

     The result of ‘mock()’ is an async function which will have the
     outcome of ‘side_effect’ or ‘return_value’ after it has been
     awaited:

        - if ‘side_effect’ is a function, the async function will return
          the result of that function,

        - if ‘side_effect’ is an exception, the async function will
          raise the exception,

        - if ‘side_effect’ is an iterable, the async function will
          return the next value of the iterable, however, if the
          sequence of result is exhausted, ‘StopAsyncIteration’ is
          raised immediately,

        - if ‘side_effect’ is not defined, the async function will
          return the value defined by ‘return_value’, hence, by default,
          the async function returns a new *note AsyncMock: c40. object.

     Setting the 'spec' of a *note Mock: c41. or *note MagicMock: 1091.
     to an async function will result in a coroutine object being
     returned after calling.

          >>> async def async_func(): pass
          ...
          >>> mock = MagicMock(async_func)
          >>> mock
          <MagicMock spec='function' id='...'>
          >>> mock()
          <coroutine object AsyncMockMixin._mock_call at ...>

     Setting the 'spec' of a *note Mock: c41, *note MagicMock: 1091, or
     *note AsyncMock: c40. to a class with asynchronous and synchronous
     functions will automatically detect the synchronous functions and
     set them as *note MagicMock: 1091. (if the parent mock is *note
     AsyncMock: c40. or *note MagicMock: 1091.) or *note Mock: c41. (if
     the parent mock is *note Mock: c41.).  All asynchronous functions
     will be *note AsyncMock: c40.

          >>> class ExampleClass:
          ...     def sync_foo():
          ...         pass
          ...     async def async_foo():
          ...         pass
          ...
          >>> a_mock = AsyncMock(ExampleClass)
          >>> a_mock.sync_foo
          <MagicMock name='mock.sync_foo' id='...'>
          >>> a_mock.async_foo
          <AsyncMock name='mock.async_foo' id='...'>
          >>> mock = Mock(ExampleClass)
          >>> mock.sync_foo
          <Mock name='mock.sync_foo' id='...'>
          >>> mock.async_foo
          <AsyncMock name='mock.async_foo' id='...'>

     Added in version 3.8.

      -- Metodo: assert_awaited ()

          Assert that the mock was awaited at least once.  Note that
          this is separate from the object having been called, the
          ‘await’ keyword must be used:

               >>> mock = AsyncMock()
               >>> async def main(coroutine_mock):
               ...     await coroutine_mock
               ...
               >>> coroutine_mock = mock()
               >>> mock.called
               True
               >>> mock.assert_awaited()
               Traceback (most recent call last):
               ...
               AssertionError: Expected mock to have been awaited.
               >>> asyncio.run(main(coroutine_mock))
               >>> mock.assert_awaited()

      -- Metodo: assert_awaited_once ()

          Assert that the mock was awaited exactly once.

               >>> mock = AsyncMock()
               >>> async def main():
               ...     await mock()
               ...
               >>> asyncio.run(main())
               >>> mock.assert_awaited_once()
               >>> asyncio.run(main())
               >>> mock.assert_awaited_once()
               Traceback (most recent call last):
               ...
               AssertionError: Expected mock to have been awaited once. Awaited 2 times.

      -- Metodo: assert_awaited_with (*args, **kwargs)

          Assert that the last await was with the specified arguments.

               >>> mock = AsyncMock()
               >>> async def main(*args, **kwargs):
               ...     await mock(*args, **kwargs)
               ...
               >>> asyncio.run(main('foo', bar='bar'))
               >>> mock.assert_awaited_with('foo', bar='bar')
               >>> mock.assert_awaited_with('other')
               Traceback (most recent call last):
               ...
               AssertionError: expected await not found.
               Expected: mock('other')
               Actual: mock('foo', bar='bar')

      -- Metodo: assert_awaited_once_with (*args, **kwargs)

          Assert that the mock was awaited exactly once and with the
          specified arguments.

               >>> mock = AsyncMock()
               >>> async def main(*args, **kwargs):
               ...     await mock(*args, **kwargs)
               ...
               >>> asyncio.run(main('foo', bar='bar'))
               >>> mock.assert_awaited_once_with('foo', bar='bar')
               >>> asyncio.run(main('foo', bar='bar'))
               >>> mock.assert_awaited_once_with('foo', bar='bar')
               Traceback (most recent call last):
               ...
               AssertionError: Expected mock to have been awaited once. Awaited 2 times.

      -- Metodo: assert_any_await (*args, **kwargs)

          Assert the mock has ever been awaited with the specified
          arguments.

               >>> mock = AsyncMock()
               >>> async def main(*args, **kwargs):
               ...     await mock(*args, **kwargs)
               ...
               >>> asyncio.run(main('foo', bar='bar'))
               >>> asyncio.run(main('hello'))
               >>> mock.assert_any_await('foo', bar='bar')
               >>> mock.assert_any_await('other')
               Traceback (most recent call last):
               ...
               AssertionError: mock('other') await not found

      -- Metodo: assert_has_awaits (calls, any_order=False)

          Assert the mock has been awaited with the specified calls.
          The *note await_args_list: 1d50. list is checked for the
          awaits.

          If 'any_order' is false then the awaits must be sequential.
          There can be extra calls before or after the specified awaits.

          If 'any_order' is true then the awaits can be in any order,
          but they must all appear in *note await_args_list: 1d50.

               >>> mock = AsyncMock()
               >>> async def main(*args, **kwargs):
               ...     await mock(*args, **kwargs)
               ...
               >>> calls = [call("foo"), call("bar")]
               >>> mock.assert_has_awaits(calls)
               Traceback (most recent call last):
               ...
               AssertionError: Awaits not found.
               Expected: [call('foo'), call('bar')]
               Actual: []
               >>> asyncio.run(main('foo'))
               >>> asyncio.run(main('bar'))
               >>> mock.assert_has_awaits(calls)

      -- Metodo: assert_not_awaited ()

          Assert that the mock was never awaited.

               >>> mock = AsyncMock()
               >>> mock.assert_not_awaited()

      -- Metodo: reset_mock (*args, **kwargs)

          See *note Mock.reset_mock(): ef8.  Also sets *note
          await_count: 4632. to 0, *note await_args: 4633. to None, and
          clears the *note await_args_list: 1d50.

      -- Attributo: await_count

          An integer keeping track of how many times the mock object has
          been awaited.

               >>> mock = AsyncMock()
               >>> async def main():
               ...     await mock()
               ...
               >>> asyncio.run(main())
               >>> mock.await_count
               1
               >>> asyncio.run(main())
               >>> mock.await_count
               2

      -- Attributo: await_args

          This is either ‘None’ (if the mock hasn’t been awaited), or
          the arguments that the mock was last awaited with.  Functions
          the same as *note Mock.call_args: 1d51.

               >>> mock = AsyncMock()
               >>> async def main(*args):
               ...     await mock(*args)
               ...
               >>> mock.await_args
               >>> asyncio.run(main('foo'))
               >>> mock.await_args
               call('foo')
               >>> asyncio.run(main('bar'))
               >>> mock.await_args
               call('bar')

      -- Attributo: await_args_list

          This is a list of all the awaits made to the mock object in
          sequence (so the length of the list is the number of times it
          has been awaited).  Before any awaits have been made it is an
          empty list.

               >>> mock = AsyncMock()
               >>> async def main(*args):
               ...     await mock(*args)
               ...
               >>> mock.await_args_list
               []
               >>> asyncio.run(main('foo'))
               >>> mock.await_args_list
               [call('foo')]
               >>> asyncio.run(main('bar'))
               >>> mock.await_args_list
               [call('foo'), call('bar')]

 -- Classe: unittest.mock.ThreadingMock (spec=None, side_effect=None,
          return_value=DEFAULT, wraps=None, name=None, spec_set=None,
          unsafe=False, *, timeout=UNSET, **kwargs)

     A version of *note MagicMock: 1091. for multithreading tests.  The
     *note ThreadingMock: 4634. object provides extra methods to wait
     for a call to be invoked, rather than assert on it immediately.

     The default timeout is specified by the ‘timeout’ argument, or if
     unset by the *note ThreadingMock.DEFAULT_TIMEOUT: 4635. attribute,
     which defaults to blocking (‘None’).

     You can configure the global default timeout by setting *note
     ThreadingMock.DEFAULT_TIMEOUT: 4635.

      -- Metodo: wait_until_called (*, timeout=UNSET)

          Waits until the mock is called.

          If a timeout was passed at the creation of the mock or if a
          timeout argument is passed to this function, the function
          raises an *note AssertionError: 8b9. if the call is not
          performed in time.

               >>> mock = ThreadingMock()
               >>> thread = threading.Thread(target=mock)
               >>> thread.start()
               >>> mock.wait_until_called(timeout=1)
               >>> thread.join()

      -- Metodo: wait_until_any_call_with (*args, **kwargs)

          Waits until the mock is called with the specified arguments.

          If a timeout was passed at the creation of the mock the
          function raises an *note AssertionError: 8b9. if the call is
          not performed in time.

               >>> mock = ThreadingMock()
               >>> thread = threading.Thread(target=mock, args=("arg1", "arg2",), kwargs={"arg": "thing"})
               >>> thread.start()
               >>> mock.wait_until_any_call_with("arg1", "arg2", arg="thing")
               >>> thread.join()

      -- Attributo: DEFAULT_TIMEOUT

          Global default timeout in seconds to create instances of *note
          ThreadingMock: 4634.

     Added in version 3.13.

* Menu:

* Calling::
* Deleting Attributes::
* Mock names and the name attribute::
* Attaching Mocks as Attributes::

   ---------- Footnotes ----------

   (1) The only exceptions are magic methods and attributes (those that
have leading and trailing double underscores).  Mock doesn’t create
these but instead raises an *note AttributeError: 5f0.  This is because
the interpreter will often implicitly request these methods, and gets
'very' confused to get a new Mock object when it expects a magic method.
If you need magic method support see *note magic methods: 4615.


File: python.info,  Node: Calling,  Next: Deleting Attributes,  Up: The Mock Class

5.26.6.3 Calling
................

Mock objects are callable.  The call will return the value set as the
*note return_value: 461b. attribute.  The default return value is a new
Mock object; it is created the first time the return value is accessed
(either explicitly or by calling the Mock) - but it is stored and the
same one returned each time.

Calls made to the object will be recorded in the attributes like *note
call_args: 1d51. and *note call_args_list: 4626.

If *note side_effect: 4613. is set then it will be called after the call
has been recorded, so if ‘side_effect’ raises an exception the call is
still recorded.

The simplest way to make a mock raise an exception when called is to
make *note side_effect: 4613. an exception class or instance:

     >>> m = MagicMock(side_effect=IndexError)
     >>> m(1, 2, 3)
     Traceback (most recent call last):
       ...
     IndexError
     >>> m.mock_calls
     [call(1, 2, 3)]
     >>> m.side_effect = KeyError('Bang!')
     >>> m('two', 'three', 'four')
     Traceback (most recent call last):
       ...
     KeyError: 'Bang!'
     >>> m.mock_calls
     [call(1, 2, 3), call('two', 'three', 'four')]

If *note side_effect: 4613. is a function then whatever that function
returns is what calls to the mock return.  The ‘side_effect’ function is
called with the same arguments as the mock.  This allows you to vary the
return value of the call dynamically, based on the input:

     >>> def side_effect(value):
     ...     return value + 1
     ...
     >>> m = MagicMock(side_effect=side_effect)
     >>> m(1)
     2
     >>> m(2)
     3
     >>> m.mock_calls
     [call(1), call(2)]

If you want the mock to still return the default return value (a new
mock), or any set return value, then there are two ways of doing this.
Either return *note return_value: 461b. from inside *note side_effect:
4613, or return *note DEFAULT: 461a.:

     >>> m = MagicMock()
     >>> def side_effect(*args, **kwargs):
     ...     return m.return_value
     ...
     >>> m.side_effect = side_effect
     >>> m.return_value = 3
     >>> m()
     3
     >>> def side_effect(*args, **kwargs):
     ...     return DEFAULT
     ...
     >>> m.side_effect = side_effect
     >>> m()
     3

To remove a *note side_effect: 4613, and return to the default
behaviour, set the ‘side_effect’ to ‘None’:

     >>> m = MagicMock(return_value=6)
     >>> def side_effect(*args, **kwargs):
     ...     return 3
     ...
     >>> m.side_effect = side_effect
     >>> m()
     3
     >>> m.side_effect = None
     >>> m()
     6

The *note side_effect: 4613. can also be any iterable object.  Repeated
calls to the mock will return values from the iterable (until the
iterable is exhausted and a *note StopIteration: df7. is raised):

     >>> m = MagicMock(side_effect=[1, 2, 3])
     >>> m()
     1
     >>> m()
     2
     >>> m()
     3
     >>> m()
     Traceback (most recent call last):
       ...
     StopIteration

If any members of the iterable are exceptions they will be raised
instead of returned:

     >>> iterable = (33, ValueError, 66)
     >>> m = MagicMock(side_effect=iterable)
     >>> m()
     33
     >>> m()
     Traceback (most recent call last):
      ...
     ValueError
     >>> m()
     66


File: python.info,  Node: Deleting Attributes,  Next: Mock names and the name attribute,  Prev: Calling,  Up: The Mock Class

5.26.6.4 Deleting Attributes
............................

Mock objects create attributes on demand.  This allows them to pretend
to be objects of any type.

You may want a mock object to return ‘False’ to a *note hasattr(): 6fa.
call, or raise an *note AttributeError: 5f0. when an attribute is
fetched.  You can do this by providing an object as a ‘spec’ for a mock,
but that isn’t always convenient.

You «block» attributes by deleting them.  Once deleted, accessing an
attribute will raise an *note AttributeError: 5f0.

     >>> mock = MagicMock()
     >>> hasattr(mock, 'm')
     True
     >>> del mock.m
     >>> hasattr(mock, 'm')
     False
     >>> del mock.f
     >>> mock.f
     Traceback (most recent call last):
         ...
     AttributeError: f


File: python.info,  Node: Mock names and the name attribute,  Next: Attaching Mocks as Attributes,  Prev: Deleting Attributes,  Up: The Mock Class

5.26.6.5 Mock names and the name attribute
..........................................

Since «name» is an argument to the *note Mock: c41. constructor, if you
want your mock object to have a «name» attribute you can’t just pass it
in at creation time.  There are two alternatives.  One option is to use
*note configure_mock(): 461c.:

     >>> mock = MagicMock()
     >>> mock.configure_mock(name='my_name')
     >>> mock.name
     'my_name'

A simpler option is to simply set the «name» attribute after mock
creation:

     >>> mock = MagicMock()
     >>> mock.name = "foo"


File: python.info,  Node: Attaching Mocks as Attributes,  Prev: Mock names and the name attribute,  Up: The Mock Class

5.26.6.6 Attaching Mocks as Attributes
......................................

When you attach a mock as an attribute of another mock (or as the return
value) it becomes a «child» of that mock.  Calls to the child are
recorded in the *note method_calls: 4621. and *note mock_calls: 461f.
attributes of the parent.  This is useful for configuring child mocks
and then attaching them to the parent, or for attaching mocks to a
parent that records all calls to the children and allows you to make
assertions about the order of calls between mocks:

     >>> parent = MagicMock()
     >>> child1 = MagicMock(return_value=None)
     >>> child2 = MagicMock(return_value=None)
     >>> parent.child1 = child1
     >>> parent.child2 = child2
     >>> child1(1)
     >>> child2(2)
     >>> parent.mock_calls
     [call.child1(1), call.child2(2)]

The exception to this is if the mock has a name.  This allows you to
prevent the «parenting» if for some reason you don’t want it to happen.

     >>> mock = MagicMock()
     >>> not_a_child = MagicMock(name='not-a-child')
     >>> mock.attribute = not_a_child
     >>> mock.attribute()
     <MagicMock name='not-a-child()' id='...'>
     >>> mock.mock_calls
     []

Mocks created for you by *note patch(): 1094. are automatically given
names.  To attach mocks that have names to a parent you use the *note
attach_mock(): 193d. method:

     >>> thing1 = object()
     >>> thing2 = object()
     >>> parent = MagicMock()
     >>> with patch('__main__.thing1', return_value=None) as child1:
     ...     with patch('__main__.thing2', return_value=None) as child2:
     ...         parent.attach_mock(child1, 'child1')
     ...         parent.attach_mock(child2, 'child2')
     ...         child1('one')
     ...         child2('two')
     ...
     >>> parent.mock_calls
     [call.child1('one'), call.child2('two')]


File: python.info,  Node: The patchers,  Next: MagicMock and magic method support,  Prev: The Mock Class,  Up: unittest mock — mock object library

5.26.6.7 The patchers
.....................

The patch decorators are used for patching objects only within the scope
of the function they decorate.  They automatically handle the unpatching
for you, even if exceptions are raised.  All of these functions can also
be used in with statements or as class decorators.

* Menu:

* patch::
* patch.object: patch object.
* patch.dict: patch dict.
* patch.multiple: patch multiple.
* patch methods; start and stop: patch methods start and stop.
* patch builtins::
* TEST_PREFIX::
* Nesting Patch Decorators::
* Where to patch::
* Patching Descriptors and Proxy Objects::


File: python.info,  Node: patch,  Next: patch object,  Up: The patchers

5.26.6.8 patch
..............

     Nota: The key is to do the patching in the right namespace.  See
     the section *note where to patch: 463f.

 -- Funzione: unittest.mock.patch (target, new=DEFAULT, spec=None,
          create=False, spec_set=None, autospec=None, new_callable=None,
          **kwargs)

     *note patch(): 1094. acts as a function decorator, class decorator
     or a context manager.  Inside the body of the function or with
     statement, the 'target' is patched with a 'new' object.  When the
     function/with statement exits the patch is undone.

     If 'new' is omitted, then the target is replaced with an *note
     AsyncMock: c40. if the patched object is an async function or a
     *note MagicMock: 1091. otherwise.  If *note patch(): 1094. is used
     as a decorator and 'new' is omitted, the created mock is passed in
     as an extra argument to the decorated function.  If *note patch():
     1094. is used as a context manager the created mock is returned by
     the context manager.

     'target' should be a string in the form
     ‘'package.module.ClassName'’.  The 'target' is imported and the
     specified object replaced with the 'new' object, so the 'target'
     must be importable from the environment you are calling *note
     patch(): 1094. from.  The target is imported when the decorated
     function is executed, not at decoration time.

     The 'spec' and 'spec_set' keyword arguments are passed to the *note
     MagicMock: 1091. if patch is creating one for you.

     In addition you can pass ‘spec=True’ or ‘spec_set=True’, which
     causes patch to pass in the object being mocked as the
     spec/spec_set object.

     'new_callable' allows you to specify a different class, or callable
     object, that will be called to create the 'new' object.  By default
     *note AsyncMock: c40. is used for async functions and *note
     MagicMock: 1091. for the rest.

     A more powerful form of 'spec' is 'autospec'.  If you set
     ‘autospec=True’ then the mock will be created with a spec from the
     object being replaced.  All attributes of the mock will also have
     the spec of the corresponding attribute of the object being
     replaced.  Methods and functions being mocked will have their
     arguments checked and will raise a *note TypeError: 198. if they
     are called with the wrong signature.  For mocks replacing a class,
     their return value (the “instance”) will have the same spec as the
     class.  See the *note create_autospec(): 191c. function and *note
     Autospeccing: 4616.

     Instead of ‘autospec=True’ you can pass ‘autospec=some_object’ to
     use an arbitrary object as the spec instead of the one being
     replaced.

     By default *note patch(): 1094. will fail to replace attributes
     that don’t exist.  If you pass in ‘create=True’, and the attribute
     doesn’t exist, patch will create the attribute for you when the
     patched function is called, and delete it again after the patched
     function has exited.  This is useful for writing tests against
     attributes that your production code creates at runtime.  It is off
     by default because it can be dangerous.  With it switched on you
     can write passing tests against APIs that don’t actually exist!

          Nota: 
          Cambiato nella versione 3.5: If you are patching builtins in a
          module then you don’t need to pass ‘create=True’, it will be
          added by default.

     Patch can be used as a *note TestCase: 2b3. class decorator.  It
     works by decorating each test method in the class.  This reduces
     the boilerplate code when your test methods share a common
     patchings set.  *note patch(): 1094. finds tests by looking for
     method names that start with ‘patch.TEST_PREFIX’.  By default this
     is ‘'test'’, which matches the way *note unittest: 10c. finds
     tests.  You can specify an alternative prefix by setting
     ‘patch.TEST_PREFIX’.

     Patch can be used as a context manager, with the with statement.
     Here the patching applies to the indented block after the with
     statement.  If you use «as» then the patched object will be bound
     to the name after the «as»; very useful if *note patch(): 1094. is
     creating a mock object for you.

     *note patch(): 1094. takes arbitrary keyword arguments.  These will
     be passed to *note AsyncMock: c40. if the patched object is
     asynchronous, to *note MagicMock: 1091. otherwise or to
     'new_callable' if specified.

     ‘patch.dict(...)’, ‘patch.multiple(...)’ and ‘patch.object(...)’
     are available for alternate use-cases.

*note patch(): 1094. as function decorator, creating the mock for you
and passing it into the decorated function:

     >>> @patch('__main__.SomeClass')
     ... def function(normal_argument, mock_class):
     ...     print(mock_class is SomeClass)
     ...
     >>> function(None)
     True

Patching a class replaces the class with a *note MagicMock: 1091.
'instance'.  If the class is instantiated in the code under test then it
will be the *note return_value: 461b. of the mock that will be used.

If the class is instantiated multiple times you could use *note
side_effect: 4613. to return a new mock each time.  Alternatively you
can set the 'return_value' to be anything you want.

To configure return values on methods of 'instances' on the patched
class you must do this on the *note return_value: 461b.  For example:

     >>> class Class:
     ...     def method(self):
     ...         pass
     ...
     >>> with patch('__main__.Class') as MockClass:
     ...     instance = MockClass.return_value
     ...     instance.method.return_value = 'foo'
     ...     assert Class() is instance
     ...     assert Class().method() == 'foo'
     ...

If you use 'spec' or 'spec_set' and *note patch(): 1094. is replacing a
'class', then the return value of the created mock will have the same
spec.

     >>> Original = Class
     >>> patcher = patch('__main__.Class', spec=True)
     >>> MockClass = patcher.start()
     >>> instance = MockClass()
     >>> assert isinstance(instance, Original)
     >>> patcher.stop()

The 'new_callable' argument is useful where you want to use an
alternative class to the default *note MagicMock: 1091. for the created
mock.  For example, if you wanted a *note NonCallableMock: 4618. to be
used:

     >>> thing = object()
     >>> with patch('__main__.thing', new_callable=NonCallableMock) as mock_thing:
     ...     assert thing is mock_thing
     ...     thing()
     ...
     Traceback (most recent call last):
       ...
     TypeError: 'NonCallableMock' object is not callable

Another use case might be to replace an object with an *note
io.StringIO: 112b. instance:

     >>> from io import StringIO
     >>> def foo():
     ...     print('Something')
     ...
     >>> @patch('sys.stdout', new_callable=StringIO)
     ... def test(mock_stdout):
     ...     foo()
     ...     assert mock_stdout.getvalue() == 'Something\n'
     ...
     >>> test()

When *note patch(): 1094. is creating a mock for you, it is common that
the first thing you need to do is to configure the mock.  Some of that
configuration can be done in the call to patch.  Any arbitrary keywords
you pass into the call will be used to set attributes on the created
mock:

     >>> patcher = patch('__main__.thing', first='one', second='two')
     >>> mock_thing = patcher.start()
     >>> mock_thing.first
     'one'
     >>> mock_thing.second
     'two'

As well as attributes on the created mock attributes, like the *note
return_value: 461b. and *note side_effect: 4613, of child mocks can also
be configured.  These aren’t syntactically valid to pass in directly as
keyword arguments, but a dictionary with these as keys can still be
expanded into a *note patch(): 1094. call using ‘**’:

     >>> config = {'method.return_value': 3, 'other.side_effect': KeyError}
     >>> patcher = patch('__main__.thing', **config)
     >>> mock_thing = patcher.start()
     >>> mock_thing.method()
     3
     >>> mock_thing.other()
     Traceback (most recent call last):
       ...
     KeyError

By default, attempting to patch a function in a module (or a method or
an attribute in a class) that does not exist will fail with *note
AttributeError: 5f0.:

     >>> @patch('sys.non_existing_attribute', 42)
     ... def test():
     ...     assert sys.non_existing_attribute == 42
     ...
     >>> test()
     Traceback (most recent call last):
       ...
     AttributeError: <module 'sys' (built-in)> does not have the attribute 'non_existing_attribute'

but adding ‘create=True’ in the call to *note patch(): 1094. will make
the previous example work as expected:

     >>> @patch('sys.non_existing_attribute', 42, create=True)
     ... def test(mock_stdout):
     ...     assert sys.non_existing_attribute == 42
     ...
     >>> test()

Cambiato nella versione 3.8: *note patch(): 1094. now returns an *note
AsyncMock: c40. if the target is an async function.


File: python.info,  Node: patch object,  Next: patch dict,  Prev: patch,  Up: The patchers

5.26.6.9 patch.object
.....................

 -- Funzione: patch.object (target, attribute, new=DEFAULT, spec=None,
          create=False, spec_set=None, autospec=None, new_callable=None,
          **kwargs)

     patch the named member ('attribute') on an object ('target') with a
     mock object.

     *note patch.object(): 18ee. can be used as a decorator, class
     decorator or a context manager.  Arguments 'new', 'spec', 'create',
     'spec_set', 'autospec' and 'new_callable' have the same meaning as
     for *note patch(): 1094.  Like *note patch(): 1094, *note
     patch.object(): 18ee. takes arbitrary keyword arguments for
     configuring the mock object it creates.

     When used as a class decorator *note patch.object(): 18ee. honours
     ‘patch.TEST_PREFIX’ for choosing which methods to wrap.

You can either call *note patch.object(): 18ee. with three arguments or
two arguments.  The three argument form takes the object to be patched,
the attribute name and the object to replace the attribute with.

When calling with the two argument form you omit the replacement object,
and a mock is created for you and passed in as an extra argument to the
decorated function:

     >>> @patch.object(SomeClass, 'class_method')
     ... def test(mock_method):
     ...     SomeClass.class_method(3)
     ...     mock_method.assert_called_with(3)
     ...
     >>> test()

'spec', 'create' and the other arguments to *note patch.object(): 18ee.
have the same meaning as they do for *note patch(): 1094.


File: python.info,  Node: patch dict,  Next: patch multiple,  Prev: patch object,  Up: The patchers

5.26.6.10 patch.dict
....................

 -- Funzione: patch.dict (in_dict, values=(), clear=False, **kwargs)

     Patch a dictionary, or dictionary like object, and restore the
     dictionary to its original state after the test, where the restored
     dictionary is a copy of the dictionary as it was before the test.

     'in_dict' can be a dictionary or a mapping like container.  If it
     is a mapping then it must at least support getting, setting and
     deleting items plus iterating over keys.

     'in_dict' can also be a string specifying the name of the
     dictionary, which will then be fetched by importing it.

     'values' can be a dictionary of values to set in the dictionary.
     'values' can also be an iterable of ‘(key, value)’ pairs.

     If 'clear' is true then the dictionary will be cleared before the
     new values are set.

     *note patch.dict(): 194f. can also be called with arbitrary keyword
     arguments to set values in the dictionary.

     Cambiato nella versione 3.8: *note patch.dict(): 194f. now returns
     the patched dictionary when used as a context manager.

*note patch.dict(): 194f. can be used as a context manager, decorator or
class decorator:

     >>> foo = {}
     >>> @patch.dict(foo, {'newkey': 'newvalue'})
     ... def test():
     ...     assert foo == {'newkey': 'newvalue'}
     ...
     >>> test()
     >>> assert foo == {}

When used as a class decorator *note patch.dict(): 194f. honours
‘patch.TEST_PREFIX’ (default to ‘'test'’) for choosing which methods to
wrap:

     >>> import os
     >>> import unittest
     >>> from unittest.mock import patch
     >>> @patch.dict('os.environ', {'newkey': 'newvalue'})
     ... class TestSample(unittest.TestCase):
     ...     def test_sample(self):
     ...         self.assertEqual(os.environ['newkey'], 'newvalue')

If you want to use a different prefix for your test, you can inform the
patchers of the different prefix by setting ‘patch.TEST_PREFIX’.  For
more details about how to change the value of see *note TEST_PREFIX:
4642.

*note patch.dict(): 194f. can be used to add members to a dictionary, or
simply let a test change a dictionary, and ensure the dictionary is
restored when the test ends.

     >>> foo = {}
     >>> with patch.dict(foo, {'newkey': 'newvalue'}) as patched_foo:
     ...     assert foo == {'newkey': 'newvalue'}
     ...     assert patched_foo == {'newkey': 'newvalue'}
     ...     # You can add, update or delete keys of foo (or patched_foo, it's the same dict)
     ...     patched_foo['spam'] = 'eggs'
     ...
     >>> assert foo == {}
     >>> assert patched_foo == {}

     >>> import os
     >>> with patch.dict('os.environ', {'newkey': 'newvalue'}):
     ...     print(os.environ['newkey'])
     ...
     newvalue
     >>> assert 'newkey' not in os.environ

Keywords can be used in the *note patch.dict(): 194f. call to set values
in the dictionary:

     >>> mymodule = MagicMock()
     >>> mymodule.function.return_value = 'fish'
     >>> with patch.dict('sys.modules', mymodule=mymodule):
     ...     import mymodule
     ...     mymodule.function('some', 'args')
     ...
     'fish'

*note patch.dict(): 194f. can be used with dictionary like objects that
aren’t actually dictionaries.  At the very minimum they must support
item getting, setting, deleting and either iteration or membership test.
This corresponds to the magic methods *note __getitem__(): 588, *note
__setitem__(): 14d3, *note __delitem__(): 14d4. and either *note
__iter__(): 2094. or *note __contains__(): 15c1.

     >>> class Container:
     ...     def __init__(self):
     ...         self.values = {}
     ...     def __getitem__(self, name):
     ...         return self.values[name]
     ...     def __setitem__(self, name, value):
     ...         self.values[name] = value
     ...     def __delitem__(self, name):
     ...         del self.values[name]
     ...     def __iter__(self):
     ...         return iter(self.values)
     ...
     >>> thing = Container()
     >>> thing['one'] = 1
     >>> with patch.dict(thing, one=2, two=3):
     ...     assert thing['one'] == 2
     ...     assert thing['two'] == 3
     ...
     >>> assert thing['one'] == 1
     >>> assert list(thing) == ['one']


File: python.info,  Node: patch multiple,  Next: patch methods start and stop,  Prev: patch dict,  Up: The patchers

5.26.6.11 patch.multiple
........................

 -- Funzione: patch.multiple (target, spec=None, create=False,
          spec_set=None, autospec=None, new_callable=None, **kwargs)

     Perform multiple patches in a single call.  It takes the object to
     be patched (either as an object or a string to fetch the object by
     importing) and keyword arguments for the patches:

          with patch.multiple(settings, FIRST_PATCH='one', SECOND_PATCH='two'):
              ...

     Use *note DEFAULT: 461a. as the value if you want *note
     patch.multiple(): 4644. to create mocks for you.  In this case the
     created mocks are passed into a decorated function by keyword, and
     a dictionary is returned when *note patch.multiple(): 4644. is used
     as a context manager.

     *note patch.multiple(): 4644. can be used as a decorator, class
     decorator or a context manager.  The arguments 'spec', 'spec_set',
     'create', 'autospec' and 'new_callable' have the same meaning as
     for *note patch(): 1094.  These arguments will be applied to 'all'
     patches done by *note patch.multiple(): 4644.

     When used as a class decorator *note patch.multiple(): 4644.
     honours ‘patch.TEST_PREFIX’ for choosing which methods to wrap.

If you want *note patch.multiple(): 4644. to create mocks for you, then
you can use *note DEFAULT: 461a. as the value.  If you use *note
patch.multiple(): 4644. as a decorator then the created mocks are passed
into the decorated function by keyword.

     >>> thing = object()
     >>> other = object()

     >>> @patch.multiple('__main__', thing=DEFAULT, other=DEFAULT)
     ... def test_function(thing, other):
     ...     assert isinstance(thing, MagicMock)
     ...     assert isinstance(other, MagicMock)
     ...
     >>> test_function()

*note patch.multiple(): 4644. can be nested with other ‘patch’
decorators, but put arguments passed by keyword 'after' any of the
standard arguments created by *note patch(): 1094.:

     >>> @patch('sys.exit')
     ... @patch.multiple('__main__', thing=DEFAULT, other=DEFAULT)
     ... def test_function(mock_exit, other, thing):
     ...     assert 'other' in repr(other)
     ...     assert 'thing' in repr(thing)
     ...     assert 'exit' in repr(mock_exit)
     ...
     >>> test_function()

If *note patch.multiple(): 4644. is used as a context manager, the value
returned by the context manager is a dictionary where created mocks are
keyed by name:

     >>> with patch.multiple('__main__', thing=DEFAULT, other=DEFAULT) as values:
     ...     assert 'other' in repr(values['other'])
     ...     assert 'thing' in repr(values['thing'])
     ...     assert values['thing'] is thing
     ...     assert values['other'] is other
     ...


File: python.info,  Node: patch methods start and stop,  Next: patch builtins,  Prev: patch multiple,  Up: The patchers

5.26.6.12 patch methods: start and stop
.......................................

All the patchers have ‘start()’ and ‘stop()’ methods.  These make it
simpler to do patching in ‘setUp’ methods or where you want to do
multiple patches without nesting decorators or with statements.

To use them call *note patch(): 1094, *note patch.object(): 18ee. or
*note patch.dict(): 194f. as normal and keep a reference to the returned
‘patcher’ object.  You can then call ‘start()’ to put the patch in place
and ‘stop()’ to undo it.

If you are using *note patch(): 1094. to create a mock for you then it
will be returned by the call to ‘patcher.start’.

     >>> patcher = patch('package.module.ClassName')
     >>> from package import module
     >>> original = module.ClassName
     >>> new_mock = patcher.start()
     >>> assert module.ClassName is not original
     >>> assert module.ClassName is new_mock
     >>> patcher.stop()
     >>> assert module.ClassName is original
     >>> assert module.ClassName is not new_mock

A typical use case for this might be for doing multiple patches in the
‘setUp’ method of a *note TestCase: 2b3.:

     >>> class MyTest(unittest.TestCase):
     ...     def setUp(self):
     ...         self.patcher1 = patch('package.module.Class1')
     ...         self.patcher2 = patch('package.module.Class2')
     ...         self.MockClass1 = self.patcher1.start()
     ...         self.MockClass2 = self.patcher2.start()
     ...
     ...     def tearDown(self):
     ...         self.patcher1.stop()
     ...         self.patcher2.stop()
     ...
     ...     def test_something(self):
     ...         assert package.module.Class1 is self.MockClass1
     ...         assert package.module.Class2 is self.MockClass2
     ...
     >>> MyTest('test_something').run()

     Attenzione: If you use this technique you must ensure that the
     patching is «undone» by calling ‘stop’.  This can be fiddlier than
     you might think, because if an exception is raised in the ‘setUp’
     then ‘tearDown’ is not called.  *note
     unittest.TestCase.addCleanup(): c76. makes this easier:

          >>> class MyTest(unittest.TestCase):
          ...     def setUp(self):
          ...         patcher = patch('package.module.Class')
          ...         self.MockClass = patcher.start()
          ...         self.addCleanup(patcher.stop)
          ...
          ...     def test_something(self):
          ...         assert package.module.Class is self.MockClass
          ...

     As an added bonus you no longer need to keep a reference to the
     ‘patcher’ object.

It is also possible to stop all patches which have been started by using
*note patch.stopall(): 4647.

 -- Funzione: patch.stopall ()

     Stop all active patches.  Only stops patches started with ‘start’.


File: python.info,  Node: patch builtins,  Next: TEST_PREFIX,  Prev: patch methods start and stop,  Up: The patchers

5.26.6.13 patch builtins
........................

You can patch any builtins within a module.  The following example
patches builtin *note ord(): 2323.:

     >>> @patch('__main__.ord')
     ... def test(mock_ord):
     ...     mock_ord.return_value = 101
     ...     print(ord('c'))
     ...
     >>> test()
     101


File: python.info,  Node: TEST_PREFIX,  Next: Nesting Patch Decorators,  Prev: patch builtins,  Up: The patchers

5.26.6.14 TEST_PREFIX
.....................

All of the patchers can be used as class decorators.  When used in this
way they wrap every test method on the class.  The patchers recognise
methods that start with ‘'test'’ as being test methods.  This is the
same way that the *note unittest.TestLoader: 593. finds test methods by
default.

It is possible that you want to use a different prefix for your tests.
You can inform the patchers of the different prefix by setting
‘patch.TEST_PREFIX’:

     >>> patch.TEST_PREFIX = 'foo'
     >>> value = 3
     >>>
     >>> @patch('__main__.value', 'not three')
     ... class Thing:
     ...     def foo_one(self):
     ...         print(value)
     ...     def foo_two(self):
     ...         print(value)
     ...
     >>>
     >>> Thing().foo_one()
     not three
     >>> Thing().foo_two()
     not three
     >>> value
     3


File: python.info,  Node: Nesting Patch Decorators,  Next: Where to patch,  Prev: TEST_PREFIX,  Up: The patchers

5.26.6.15 Nesting Patch Decorators
..................................

If you want to perform multiple patches then you can simply stack up the
decorators.

You can stack up multiple patch decorators using this pattern:

     >>> @patch.object(SomeClass, 'class_method')
     ... @patch.object(SomeClass, 'static_method')
     ... def test(mock1, mock2):
     ...     assert SomeClass.static_method is mock1
     ...     assert SomeClass.class_method is mock2
     ...     SomeClass.static_method('foo')
     ...     SomeClass.class_method('bar')
     ...     return mock1, mock2
     ...
     >>> mock1, mock2 = test()
     >>> mock1.assert_called_once_with('foo')
     >>> mock2.assert_called_once_with('bar')

Note that the decorators are applied from the bottom upwards.  This is
the standard way that Python applies decorators.  The order of the
created mocks passed into your test function matches this order.


File: python.info,  Node: Where to patch,  Next: Patching Descriptors and Proxy Objects,  Prev: Nesting Patch Decorators,  Up: The patchers

5.26.6.16 Where to patch
........................

*note patch(): 1094. works by (temporarily) changing the object that a
'name' points to with another one.  There can be many names pointing to
any individual object, so for patching to work you must ensure that you
patch the name used by the system under test.

The basic principle is that you patch where an object is 'looked up',
which is not necessarily the same place as where it is defined.  A
couple of examples will help to clarify this.

Imagine we have a project that we want to test with the following
structure:

     a.py
         -> Defines SomeClass

     b.py
         -> from a import SomeClass
         -> some_function instantiates SomeClass

Now we want to test ‘some_function’ but we want to mock out ‘SomeClass’
using *note patch(): 1094.  The problem is that when we import module b,
which we will have to do when it imports ‘SomeClass’ from module a.  If
we use *note patch(): 1094. to mock out ‘a.SomeClass’ then it will have
no effect on our test; module b already has a reference to the 'real'
‘SomeClass’ and it looks like our patching had no effect.

The key is to patch out ‘SomeClass’ where it is used (or where it is
looked up).  In this case ‘some_function’ will actually look up
‘SomeClass’ in module b, where we have imported it.  The patching should
look like:

     @patch('b.SomeClass')

However, consider the alternative scenario where instead of ‘from a
import SomeClass’ module b does ‘import a’ and ‘some_function’ uses
‘a.SomeClass’.  Both of these import forms are common.  In this case the
class we want to patch is being looked up in the module and so we have
to patch ‘a.SomeClass’ instead:

     @patch('a.SomeClass')


File: python.info,  Node: Patching Descriptors and Proxy Objects,  Prev: Where to patch,  Up: The patchers

5.26.6.17 Patching Descriptors and Proxy Objects
................................................

Both *note patch: 463e. and *note patch.object: 4640. correctly patch
and restore descriptors: class methods, static methods and properties.
You should patch these on the 'class' rather than an instance.  They
also work with 'some' objects that proxy attribute access, like the
django settings object(1).

   ---------- Footnotes ----------

   (1) 
https://web.archive.org/web/20200603181648/http://www.voidspace.org.uk/python/weblog/arch_d7_2010_12_04.shtml#e1198


File: python.info,  Node: MagicMock and magic method support,  Next: Helpers,  Prev: The patchers,  Up: unittest mock — mock object library

5.26.6.18 MagicMock and magic method support
............................................

* Menu:

* Mocking Magic Methods::
* Magic Mock::


File: python.info,  Node: Mocking Magic Methods,  Next: Magic Mock,  Up: MagicMock and magic method support

5.26.6.19 Mocking Magic Methods
...............................

*note Mock: c41. supports mocking the Python protocol methods, also
known as *note «magic methods»: 464f.  This allows mock objects to
replace containers or other objects that implement Python protocols.

Because magic methods are looked up differently from normal methods (1),
this support has been specially implemented.  This means that only
specific magic methods are supported.  The supported list includes
'almost' all of them.  If there are any missing that you need please let
us know.

You mock magic methods by setting the method you are interested in to a
function or a mock instance.  If you are using a function then it 'must'
take ‘self’ as the first argument (2).

     >>> def __str__(self):
     ...     return 'fooble'
     ...
     >>> mock = Mock()
     >>> mock.__str__ = __str__
     >>> str(mock)
     'fooble'

     >>> mock = Mock()
     >>> mock.__str__ = Mock()
     >>> mock.__str__.return_value = 'fooble'
     >>> str(mock)
     'fooble'

     >>> mock = Mock()
     >>> mock.__iter__ = Mock(return_value=iter([]))
     >>> list(mock)
     []

One use case for this is for mocking objects used as context managers in
a *note with: 186. statement:

     >>> mock = Mock()
     >>> mock.__enter__ = Mock(return_value='foo')
     >>> mock.__exit__ = Mock(return_value=False)
     >>> with mock as m:
     ...     assert m == 'foo'
     ...
     >>> mock.__enter__.assert_called_with()
     >>> mock.__exit__.assert_called_with(None, None, None)

Calls to magic methods do not appear in *note method_calls: 4621, but
they are recorded in *note mock_calls: 461f.

     Nota: If you use the 'spec' keyword argument to create a mock then
     attempting to set a magic method that isn’t in the spec will raise
     an *note AttributeError: 5f0.

The full list of supported magic methods is:

   * ‘__hash__’, ‘__sizeof__’, ‘__repr__’ and ‘__str__’

   * ‘__dir__’, ‘__format__’ and ‘__subclasses__’

   * ‘__round__’, ‘__floor__’, ‘__trunc__’ and ‘__ceil__’

   * Comparisons: ‘__lt__’, ‘__gt__’, ‘__le__’, ‘__ge__’, ‘__eq__’ and
     ‘__ne__’

   * Container methods: ‘__getitem__’, ‘__setitem__’, ‘__delitem__’,
     ‘__contains__’, ‘__len__’, ‘__iter__’, ‘__reversed__’ and
     ‘__missing__’

   * Context manager: ‘__enter__’, ‘__exit__’, ‘__aenter__’ and
     ‘__aexit__’

   * Unary numeric methods: ‘__neg__’, ‘__pos__’ and ‘__invert__’

   * The numeric methods (including right hand and in-place variants):
     ‘__add__’, ‘__sub__’, ‘__mul__’, ‘__matmul__’, ‘__truediv__’,
     ‘__floordiv__’, ‘__mod__’, ‘__divmod__’, ‘__lshift__’,
     ‘__rshift__’, ‘__and__’, ‘__xor__’, ‘__or__’, and ‘__pow__’

   * Numeric conversion methods: ‘__complex__’, ‘__int__’, ‘__float__’
     and ‘__index__’

   * Descriptor methods: ‘__get__’, ‘__set__’ and ‘__delete__’

   * Pickling: ‘__reduce__’, ‘__reduce_ex__’, ‘__getinitargs__’,
     ‘__getnewargs__’, ‘__getstate__’ and ‘__setstate__’

   * File system path representation: ‘__fspath__’

   * Asynchronous iteration methods: ‘__aiter__’ and ‘__anext__’

Cambiato nella versione 3.8: Added support for *note
os.PathLike.__fspath__(): e4e.

Cambiato nella versione 3.8: Added support for ‘__aenter__’,
‘__aexit__’, ‘__aiter__’ and ‘__anext__’.

The following methods exist but are 'not' supported as they are either
in use by mock, can’t be set dynamically, or can cause problems:

   * ‘__getattr__’, ‘__setattr__’, ‘__init__’ and ‘__new__’

   * ‘__prepare__’, ‘__instancecheck__’, ‘__subclasscheck__’, ‘__del__’

   ---------- Footnotes ----------

   (1) Magic methods 'should' be looked up on the class rather than the
instance.  Different versions of Python are inconsistent about applying
this rule.  The supported protocol methods should work with all
supported versions of Python.

   (2) The function is basically hooked up to the class, but each ‘Mock’
instance is kept isolated from the others.


File: python.info,  Node: Magic Mock,  Prev: Mocking Magic Methods,  Up: MagicMock and magic method support

5.26.6.20 Magic Mock
....................

There are two ‘MagicMock’ variants: *note MagicMock: 1091. and *note
NonCallableMagicMock: 4619.

 -- Classe: unittest.mock.MagicMock (*args, **kw)

     ‘MagicMock’ is a subclass of *note Mock: c41. with default
     implementations of most of the *note magic methods: 464f.  You can
     use ‘MagicMock’ without having to configure the magic methods
     yourself.

     The constructor parameters have the same meaning as for *note Mock:
     c41.

     If you use the 'spec' or 'spec_set' arguments then 'only' magic
     methods that exist in the spec will be created.

 -- Classe: unittest.mock.NonCallableMagicMock (*args, **kw)

     A non-callable version of *note MagicMock: 1091.

     The constructor parameters have the same meaning as for *note
     MagicMock: 1091, with the exception of 'return_value' and
     'side_effect' which have no meaning on a non-callable mock.

The magic methods are setup with *note MagicMock: 1091. objects, so you
can configure them and use them in the usual way:

     >>> mock = MagicMock()
     >>> mock[3] = 'fish'
     >>> mock.__setitem__.assert_called_with(3, 'fish')
     >>> mock.__getitem__.return_value = 'result'
     >>> mock[2]
     'result'

By default many of the protocol methods are required to return objects
of a specific type.  These methods are preconfigured with a default
return value, so that they can be used without you having to do anything
if you aren’t interested in the return value.  You can still 'set' the
return value manually if you want to change the default.

Methods and their defaults:

   * ‘__lt__’: *note NotImplemented: 1a2.

   * ‘__gt__’: ‘NotImplemented’

   * ‘__le__’: ‘NotImplemented’

   * ‘__ge__’: ‘NotImplemented’

   * ‘__int__’: ‘1’

   * ‘__contains__’: ‘False’

   * ‘__len__’: ‘0’

   * ‘__iter__’: ‘iter([])’

   * ‘__exit__’: ‘False’

   * ‘__aexit__’: ‘False’

   * ‘__complex__’: ‘1j’

   * ‘__float__’: ‘1.0’

   * ‘__bool__’: ‘True’

   * ‘__index__’: ‘1’

   * ‘__hash__’: default hash for the mock

   * ‘__str__’: default str for the mock

   * ‘__sizeof__’: default sizeof for the mock

For example:

     >>> mock = MagicMock()
     >>> int(mock)
     1
     >>> len(mock)
     0
     >>> list(mock)
     []
     >>> object() in mock
     False

The two equality methods, ‘__eq__()’ and ‘__ne__()’, are special.  They
do the default equality comparison on identity, using the *note
side_effect: 4613. attribute, unless you change their return value to
return something else:

     >>> MagicMock() == 3
     False
     >>> MagicMock() != 3
     True
     >>> mock = MagicMock()
     >>> mock.__eq__.return_value = True
     >>> mock == 3
     True

The return value of ‘MagicMock.__iter__()’ can be any iterable object
and isn’t required to be an iterator:

     >>> mock = MagicMock()
     >>> mock.__iter__.return_value = ['a', 'b', 'c']
     >>> list(mock)
     ['a', 'b', 'c']
     >>> list(mock)
     ['a', 'b', 'c']

If the return value 'is' an iterator, then iterating over it once will
consume it and subsequent iterations will result in an empty list:

     >>> mock.__iter__.return_value = iter(['a', 'b', 'c'])
     >>> list(mock)
     ['a', 'b', 'c']
     >>> list(mock)
     []

‘MagicMock’ has all of the supported magic methods configured except for
some of the obscure and obsolete ones.  You can still set these up if
you want.

Magic methods that are supported but not setup by default in ‘MagicMock’
are:

   * ‘__subclasses__’

   * ‘__dir__’

   * ‘__format__’

   * ‘__get__’, ‘__set__’ and ‘__delete__’

   * ‘__reversed__’ and ‘__missing__’

   * ‘__reduce__’, ‘__reduce_ex__’, ‘__getinitargs__’, ‘__getnewargs__’,
     ‘__getstate__’ and ‘__setstate__’

   * ‘__getformat__’


File: python.info,  Node: Helpers,  Next: Order of precedence of side_effect return_value and wraps,  Prev: MagicMock and magic method support,  Up: unittest mock — mock object library

5.26.6.21 Helpers
.................

* Menu:

* sentinel::
* DEFAULT::
* call::
* create_autospec::
* ANY::
* FILTER_DIR::
* mock_open::
* Autospeccing::
* Sealing mocks::


File: python.info,  Node: sentinel,  Next: DEFAULT,  Up: Helpers

5.26.6.22 sentinel
..................

 -- Dati: unittest.mock.sentinel

     The ‘sentinel’ object provides a convenient way of providing unique
     objects for your tests.

     Attributes are created on demand when you access them by name.
     Accessing the same attribute will always return the same object.
     The objects returned have a sensible repr so that test failure
     messages are readable.

     Cambiato nella versione 3.7: The ‘sentinel’ attributes now preserve
     their identity when they are *note copied: 29. or *note pickled:
     ab.

Sometimes when testing you need to test that a specific object is passed
as an argument to another method, or returned.  It can be common to
create named sentinel objects to test this.  *note sentinel: d9b.
provides a convenient way of creating and testing the identity of
objects like this.

In this example we monkey patch ‘method’ to return
‘sentinel.some_object’:

     >>> real = ProductionClass()
     >>> real.method = Mock(name="method")
     >>> real.method.return_value = sentinel.some_object
     >>> result = real.method()
     >>> assert result is sentinel.some_object
     >>> result
     sentinel.some_object


File: python.info,  Node: DEFAULT,  Next: call,  Prev: sentinel,  Up: Helpers

5.26.6.23 DEFAULT
.................

 -- Dati: unittest.mock.DEFAULT

     The *note DEFAULT: 461a. object is a pre-created sentinel (actually
     ‘sentinel.DEFAULT’).  It can be used by *note side_effect: 4613.
     functions to indicate that the normal return value should be used.


File: python.info,  Node: call,  Next: create_autospec,  Prev: DEFAULT,  Up: Helpers

5.26.6.24 call
..............

 -- Funzione: unittest.mock.call (*args, **kwargs)

     *note call(): 1d9b. is a helper object for making simpler
     assertions, for comparing with *note call_args: 1d51, *note
     call_args_list: 4626, *note mock_calls: 461f. and *note
     method_calls: 4621.  *note call(): 1d9b. can also be used with
     *note assert_has_calls(): 1a0a.

          >>> m = MagicMock(return_value=None)
          >>> m(1, 2, a='foo', b='bar')
          >>> m()
          >>> m.call_args_list == [call(1, 2, a='foo', b='bar'), call()]
          True

 -- Metodo: call.call_list ()

     For a call object that represents multiple calls, *note
     call_list(): 4655. returns a list of all the intermediate calls as
     well as the final call.

‘call_list’ is particularly useful for making assertions on «chained
calls».  A chained call is multiple calls on a single line of code.
This results in multiple entries in *note mock_calls: 461f. on a mock.
Manually constructing the sequence of calls can be tedious.

*note call_list(): 4655. can construct the sequence of calls from the
same chained call:

     >>> m = MagicMock()
     >>> m(1).method(arg='foo').other('bar')(2.0)
     <MagicMock name='mock().method().other()()' id='...'>
     >>> kall = call(1).method(arg='foo').other('bar')(2.0)
     >>> kall.call_list()
     [call(1),
      call().method(arg='foo'),
      call().method().other('bar'),
      call().method().other()(2.0)]
     >>> m.mock_calls == kall.call_list()
     True
A ‘call’ object is either a tuple of (positional args, keyword args) or
(name, positional args, keyword args) depending on how it was
constructed.  When you construct them yourself this isn’t particularly
interesting, but the ‘call’ objects that are in the *note
Mock.call_args: 1d51, *note Mock.call_args_list: 4626. and *note
Mock.mock_calls: 461f. attributes can be introspected to get at the
individual arguments they contain.

The ‘call’ objects in *note Mock.call_args: 1d51. and *note
Mock.call_args_list: 4626. are two-tuples of (positional args, keyword
args) whereas the ‘call’ objects in *note Mock.mock_calls: 461f, along
with ones you construct yourself, are three-tuples of (name, positional
args, keyword args).

You can use their «tupleness» to pull out the individual arguments for
more complex introspection and assertions.  The positional arguments are
a tuple (an empty tuple if there are no positional arguments) and the
keyword arguments are a dictionary:

     >>> m = MagicMock(return_value=None)
     >>> m(1, 2, 3, arg='one', arg2='two')
     >>> kall = m.call_args
     >>> kall.args
     (1, 2, 3)
     >>> kall.kwargs
     {'arg': 'one', 'arg2': 'two'}
     >>> kall.args is kall[0]
     True
     >>> kall.kwargs is kall[1]
     True

     >>> m = MagicMock()
     >>> m.foo(4, 5, 6, arg='two', arg2='three')
     <MagicMock name='mock.foo()' id='...'>
     >>> kall = m.mock_calls[0]
     >>> name, args, kwargs = kall
     >>> name
     'foo'
     >>> args
     (4, 5, 6)
     >>> kwargs
     {'arg': 'two', 'arg2': 'three'}
     >>> name is m.mock_calls[0][0]
     True


File: python.info,  Node: create_autospec,  Next: ANY,  Prev: call,  Up: Helpers

5.26.6.25 create_autospec
.........................

 -- Funzione: unittest.mock.create_autospec (spec, spec_set=False,
          instance=False, **kwargs)

     Create a mock object using another object as a spec.  Attributes on
     the mock will use the corresponding attribute on the 'spec' object
     as their spec.

     Functions or methods being mocked will have their arguments checked
     to ensure that they are called with the correct signature.

     If 'spec_set' is ‘True’ then attempting to set attributes that
     don’t exist on the spec object will raise an *note AttributeError:
     5f0.

     If a class is used as a spec then the return value of the mock (the
     instance of the class) will have the same spec.  You can use a
     class as the spec for an instance object by passing
     ‘instance=True’.  The returned mock will only be callable if
     instances of the mock are callable.

     *note create_autospec(): 191c. also takes arbitrary keyword
     arguments that are passed to the constructor of the created mock.

See *note Autospeccing: 4616. for examples of how to use auto-speccing
with *note create_autospec(): 191c. and the 'autospec' argument to *note
patch(): 1094.

Cambiato nella versione 3.8: *note create_autospec(): 191c. now returns
an *note AsyncMock: c40. if the target is an async function.


File: python.info,  Node: ANY,  Next: FILTER_DIR,  Prev: create_autospec,  Up: Helpers

5.26.6.26 ANY
.............

 -- Dati: unittest.mock.ANY

Sometimes you may need to make assertions about 'some' of the arguments
in a call to mock, but either not care about some of the arguments or
want to pull them individually out of *note call_args: 1d51. and make
more complex assertions on them.

To ignore certain arguments you can pass in objects that compare equal
to 'everything'.  Calls to *note assert_called_with(): 1deb. and *note
assert_called_once_with(): 461d. will then succeed no matter what was
passed in.

     >>> mock = Mock(return_value=None)
     >>> mock('foo', bar=object())
     >>> mock.assert_called_once_with('foo', bar=ANY)

*note ANY: 1d99. can also be used in comparisons with call lists like
*note mock_calls: 461f.:

     >>> m = MagicMock(return_value=None)
     >>> m(1)
     >>> m(1, 2)
     >>> m(object())
     >>> m.mock_calls == [call(1), call(1, 2), ANY]
     True

*note ANY: 1d99. is not limited to comparisons with call objects and so
can also be used in test assertions:

     class TestStringMethods(unittest.TestCase):

         def test_split(self):
             s = 'hello world'
             self.assertEqual(s.split(), ['hello', ANY])


File: python.info,  Node: FILTER_DIR,  Next: mock_open,  Prev: ANY,  Up: Helpers

5.26.6.27 FILTER_DIR
....................

 -- Dati: unittest.mock.FILTER_DIR

*note FILTER_DIR: 4623. is a module level variable that controls the way
mock objects respond to *note dir(): 845.  The default is ‘True’, which
uses the filtering described below, to only show useful members.  If you
dislike this filtering, or need to switch it off for diagnostic
purposes, then set ‘mock.FILTER_DIR = False’.

With filtering on, ‘dir(some_mock)’ shows only useful attributes and
will include any dynamically created attributes that wouldn’t normally
be shown.  If the mock was created with a 'spec' (or 'autospec' of
course) then all the attributes from the original are shown, even if
they haven’t been accessed yet:

     >>> dir(Mock())
     ['assert_any_call',
      'assert_called',
      'assert_called_once',
      'assert_called_once_with',
      'assert_called_with',
      'assert_has_calls',
      'assert_not_called',
      'attach_mock',
      ...
     >>> from urllib import request
     >>> dir(Mock(spec=request))
     ['AbstractBasicAuthHandler',
      'AbstractDigestAuthHandler',
      'AbstractHTTPHandler',
      'BaseHandler',
      ...

Many of the not-very-useful (private to *note Mock: c41. rather than the
thing being mocked) underscore and double underscore prefixed attributes
have been filtered from the result of calling *note dir(): 845. on a
*note Mock: c41.  If you dislike this behaviour you can switch it off by
setting the module level switch *note FILTER_DIR: 4623.:

     >>> from unittest import mock
     >>> mock.FILTER_DIR = False
     >>> dir(mock.Mock())
     ['_NonCallableMock__get_return_value',
      '_NonCallableMock__get_side_effect',
      '_NonCallableMock__return_value_doc',
      '_NonCallableMock__set_return_value',
      '_NonCallableMock__set_side_effect',
      '__call__',
      '__class__',
      ...

Alternatively you can just use ‘vars(my_mock)’ (instance members) and
‘dir(type(my_mock))’ (type members) to bypass the filtering irrespective
of *note FILTER_DIR: 4623.


File: python.info,  Node: mock_open,  Next: Autospeccing,  Prev: FILTER_DIR,  Up: Helpers

5.26.6.28 mock_open
...................

 -- Funzione: unittest.mock.mock_open (mock=None, read_data=None)

     A helper function to create a mock to replace the use of *note
     open(): 316.  It works for *note open(): 316. called directly or
     used as a context manager.

     The 'mock' argument is the mock object to configure.  If ‘None’
     (the default) then a *note MagicMock: 1091. will be created for
     you, with the API limited to methods or attributes available on
     standard file handles.

     'read_data' is a string for the *note read(): 101f, *note
     readline(): 1531, and *note readlines(): 2784. methods of the file
     handle to return.  Calls to those methods will take data from
     'read_data' until it is depleted.  The mock of these methods is
     pretty simplistic: every time the 'mock' is called, the 'read_data'
     is rewound to the start.  If you need more control over the data
     that you are feeding to the tested code you will need to customize
     this mock for yourself.  When that is insufficient, one of the
     in-memory filesystem packages on PyPI(1) can offer a realistic
     filesystem for testing.

     Cambiato nella versione 3.4: Added *note readline(): 1531. and
     *note readlines(): 2784. support.  The mock of *note read(): 101f.
     changed to consume 'read_data' rather than returning it on each
     call.

     Cambiato nella versione 3.5: 'read_data' is now reset on each call
     to the 'mock'.

     Cambiato nella versione 3.8: Added *note __iter__(): 2094. to
     implementation so that iteration (such as in for loops) correctly
     consumes 'read_data'.

Using *note open(): 316. as a context manager is a great way to ensure
your file handles are closed properly and is becoming common:

     with open('/some/path', 'w') as f:
         f.write('something')

The issue is that even if you mock out the call to *note open(): 316. it
is the 'returned object' that is used as a context manager (and has
*note __enter__(): 7e5. and *note __exit__(): 1508. called).

Mocking context managers with a *note MagicMock: 1091. is common enough
and fiddly enough that a helper function is useful.

     >>> m = mock_open()
     >>> with patch('__main__.open', m):
     ...     with open('foo', 'w') as h:
     ...         h.write('some stuff')
     ...
     >>> m.mock_calls
     [call('foo', 'w'),
      call().__enter__(),
      call().write('some stuff'),
      call().__exit__(None, None, None)]
     >>> m.assert_called_once_with('foo', 'w')
     >>> handle = m()
     >>> handle.write.assert_called_once_with('some stuff')

And for reading files:

     >>> with patch('__main__.open', mock_open(read_data='bibble')) as m:
     ...     with open('foo') as h:
     ...         result = h.read()
     ...
     >>> m.assert_called_once_with('foo')
     >>> assert result == 'bibble'

   ---------- Footnotes ----------

   (1) https://pypi.org


File: python.info,  Node: Autospeccing,  Next: Sealing mocks,  Prev: mock_open,  Up: Helpers

5.26.6.29 Autospeccing
......................

Autospeccing is based on the existing ‘spec’ feature of mock.  It limits
the api of mocks to the api of an original object (the spec), but it is
recursive (implemented lazily) so that attributes of mocks only have the
same api as the attributes of the spec.  In addition mocked functions /
methods have the same call signature as the original so they raise a
*note TypeError: 198. if they are called incorrectly.

Before I explain how auto-speccing works, here’s why it is needed.

*note Mock: c41. is a very powerful and flexible object, but it suffers
from a flaw which is general to mocking.  If you refactor some of your
code, rename members and so on, any tests for code that is still using
the 'old api' but uses mocks instead of the real objects will still
pass.  This means your tests can all pass even though your code is
broken.

Cambiato nella versione 3.5: Before 3.5, tests with a typo in the word
assert would silently pass when they should raise an error.  You can
still achieve this behavior by passing ‘unsafe=True’ to Mock.

Note that this is another reason why you need integration tests as well
as unit tests.  Testing everything in isolation is all fine and dandy,
but if you don’t test how your units are «wired together» there is still
lots of room for bugs that tests might have caught.

*note unittest.mock: 10d. already provides a feature to help with this,
called speccing.  If you use a class or instance as the ‘spec’ for a
mock then you can only access attributes on the mock that exist on the
real class:

     >>> from urllib import request
     >>> mock = Mock(spec=request.Request)
     >>> mock.assret_called_with  # Intentional typo!
     Traceback (most recent call last):
      ...
     AttributeError: Mock object has no attribute 'assret_called_with'

The spec only applies to the mock itself, so we still have the same
issue with any methods on the mock:

     >>> mock.header_items()
     <mock.Mock object at 0x...>
     >>> mock.header_items.assret_called_with()  # Intentional typo!

Auto-speccing solves this problem.  You can either pass ‘autospec=True’
to *note patch(): 1094. / *note patch.object(): 18ee. or use the *note
create_autospec(): 191c. function to create a mock with a spec.  If you
use the ‘autospec=True’ argument to *note patch(): 1094. then the object
that is being replaced will be used as the spec object.  Because the
speccing is done «lazily» (the spec is created as attributes on the mock
are accessed) you can use it with very complex or deeply nested objects
(like modules that import modules that import modules) without a big
performance hit.

Here’s an example of it in use:

     >>> from urllib import request
     >>> patcher = patch('__main__.request', autospec=True)
     >>> mock_request = patcher.start()
     >>> request is mock_request
     True
     >>> mock_request.Request
     <MagicMock name='request.Request' spec='Request' id='...'>

You can see that ‘request.Request’ has a spec.  ‘request.Request’ takes
two arguments in the constructor (one of which is 'self').  Here’s what
happens if we try to call it incorrectly:

     >>> req = request.Request()
     Traceback (most recent call last):
      ...
     TypeError: <lambda>() takes at least 2 arguments (1 given)

The spec also applies to instantiated classes (i.e.  the return value of
specced mocks):

     >>> req = request.Request('foo')
     >>> req
     <NonCallableMagicMock name='request.Request()' spec='Request' id='...'>

‘Request’ objects are not callable, so the return value of instantiating
our mocked out ‘request.Request’ is a non-callable mock.  With the spec
in place any typos in our asserts will raise the correct error:

     >>> req.add_header('spam', 'eggs')
     <MagicMock name='request.Request().add_header()' id='...'>
     >>> req.add_header.assret_called_with  # Intentional typo!
     Traceback (most recent call last):
      ...
     AttributeError: Mock object has no attribute 'assret_called_with'
     >>> req.add_header.assert_called_with('spam', 'eggs')

In many cases you will just be able to add ‘autospec=True’ to your
existing *note patch(): 1094. calls and then be protected against bugs
due to typos and api changes.

As well as using 'autospec' through *note patch(): 1094. there is a
*note create_autospec(): 191c. for creating autospecced mocks directly:

     >>> from urllib import request
     >>> mock_request = create_autospec(request)
     >>> mock_request.Request('foo', 'bar')
     <NonCallableMagicMock name='mock.Request()' spec='Request' id='...'>

This isn’t without caveats and limitations however, which is why it is
not the default behaviour.  In order to know what attributes are
available on the spec object, autospec has to introspect (access
attributes) the spec.  As you traverse attributes on the mock a
corresponding traversal of the original object is happening under the
hood.  If any of your specced objects have properties or descriptors
that can trigger code execution then you may not be able to use
autospec.  On the other hand it is much better to design your objects so
that introspection is safe (1).

A more serious problem is that it is common for instance attributes to
be created in the *note __init__(): 8c0. method and not to exist on the
class at all.  'autospec' can’t know about any dynamically created
attributes and restricts the api to visible attributes.

     >>> class Something:
     ...   def __init__(self):
     ...     self.a = 33
     ...
     >>> with patch('__main__.Something', autospec=True):
     ...   thing = Something()
     ...   thing.a
     ...
     Traceback (most recent call last):
       ...
     AttributeError: Mock object has no attribute 'a'

There are a few different ways of resolving this problem.  The easiest,
but not necessarily the least annoying, way is to simply set the
required attributes on the mock after creation.  Just because 'autospec'
doesn’t allow you to fetch attributes that don’t exist on the spec it
doesn’t prevent you setting them:

     >>> with patch('__main__.Something', autospec=True):
     ...   thing = Something()
     ...   thing.a = 33
     ...

There is a more aggressive version of both 'spec' and 'autospec' that
'does' prevent you setting non-existent attributes.  This is useful if
you want to ensure your code only 'sets' valid attributes too, but
obviously it prevents this particular scenario:

     >>> with patch('__main__.Something', autospec=True, spec_set=True):
     ...   thing = Something()
     ...   thing.a = 33
     ...
     Traceback (most recent call last):
      ...
     AttributeError: Mock object has no attribute 'a'

Probably the best way of solving the problem is to add class attributes
as default values for instance members initialised in *note __init__():
8c0.  Note that if you are only setting default attributes in
‘__init__()’ then providing them via class attributes (shared between
instances of course) is faster too.  e.g.

     class Something:
         a = 33

This brings up another issue.  It is relatively common to provide a
default value of ‘None’ for members that will later be an object of a
different type.  ‘None’ would be useless as a spec because it wouldn’t
let you access 'any' attributes or methods on it.  As ‘None’ is 'never'
going to be useful as a spec, and probably indicates a member that will
normally of some other type, autospec doesn’t use a spec for members
that are set to ‘None’.  These will just be ordinary mocks (well -
MagicMocks):

     >>> class Something:
     ...     member = None
     ...
     >>> mock = create_autospec(Something)
     >>> mock.member.foo.bar.baz()
     <MagicMock name='mock.member.foo.bar.baz()' id='...'>

If modifying your production classes to add defaults isn’t to your
liking then there are more options.  One of these is simply to use an
instance as the spec rather than the class.  The other is to create a
subclass of the production class and add the defaults to the subclass
without affecting the production class.  Both of these require you to
use an alternative object as the spec.  Thankfully *note patch(): 1094.
supports this - you can simply pass the alternative object as the
'autospec' argument:

     >>> class Something:
     ...   def __init__(self):
     ...     self.a = 33
     ...
     >>> class SomethingForTest(Something):
     ...   a = 33
     ...
     >>> p = patch('__main__.Something', autospec=SomethingForTest)
     >>> mock = p.start()
     >>> mock.a
     <NonCallableMagicMock name='Something.a' spec='int' id='...'>

   ---------- Footnotes ----------

   (1) This only applies to classes or already instantiated objects.
Calling a mocked class to create a mock instance 'does not' create a
real instance.  It is only attribute lookups - along with calls to *note
dir(): 845. - that are done.


File: python.info,  Node: Sealing mocks,  Prev: Autospeccing,  Up: Helpers

5.26.6.30 Sealing mocks
.......................

 -- Funzione: unittest.mock.seal (mock)

     Seal will disable the automatic creation of mocks when accessing an
     attribute of the mock being sealed or any of its attributes that
     are already mocks recursively.

     If a mock instance with a name or a spec is assigned to an
     attribute it won’t be considered in the sealing chain.  This allows
     one to prevent seal from fixing part of the mock object.

          >>> mock = Mock()
          >>> mock.submock.attribute1 = 2
          >>> mock.not_submock = mock.Mock(name="sample_name")
          >>> seal(mock)
          >>> mock.new_attribute  # This will raise AttributeError.
          >>> mock.submock.attribute2  # This will raise AttributeError.
          >>> mock.not_submock.attribute2  # This won't raise.

     Added in version 3.7.


File: python.info,  Node: Order of precedence of side_effect return_value and wraps,  Prev: Helpers,  Up: unittest mock — mock object library

5.26.6.31 Order of precedence of ‘side_effect’, ‘return_value’ and 'wraps'
..........................................................................

The order of their precedence is:

  1. *note side_effect: 4613.

  2. *note return_value: 461b.

  3. 'wraps'

If all three are set, mock will return the value from *note side_effect:
4613, ignoring *note return_value: 461b. and the wrapped object
altogether.  If any two are set, the one with the higher precedence will
return the value.  Regardless of the order of which was set first, the
order of precedence remains unchanged.

     >>> from unittest.mock import Mock
     >>> class Order:
     ...     @staticmethod
     ...     def get_value():
     ...         return "third"
     ...
     >>> order_mock = Mock(spec=Order, wraps=Order)
     >>> order_mock.get_value.side_effect = ["first"]
     >>> order_mock.get_value.return_value = "second"
     >>> order_mock.get_value()
     'first'

As ‘None’ is the default value of *note side_effect: 4613, if you
reassign its value back to ‘None’, the order of precedence will be
checked between *note return_value: 461b. and the wrapped object,
ignoring *note side_effect: 4613.

     >>> order_mock.get_value.side_effect = None
     >>> order_mock.get_value()
     'second'

If the value being returned by *note side_effect: 4613. is *note
DEFAULT: 461a, it is ignored and the order of precedence moves to the
successor to obtain the value to return.

     >>> from unittest.mock import DEFAULT
     >>> order_mock.get_value.side_effect = [DEFAULT]
     >>> order_mock.get_value()
     'second'

When *note Mock: c41. wraps an object, the default value of *note
return_value: 461b. will be *note DEFAULT: 461a.

     >>> order_mock = Mock(spec=Order, wraps=Order)
     >>> order_mock.return_value
     sentinel.DEFAULT
     >>> order_mock.get_value.return_value
     sentinel.DEFAULT

The order of precedence will ignore this value and it will move to the
last successor which is the wrapped object.

As the real call is being made to the wrapped object, creating an
instance of this mock will return the real instance of the class.  The
positional arguments, if any, required by the wrapped object must be
passed.

     >>> order_mock_instance = order_mock()
     >>> isinstance(order_mock_instance, Order)
     True
     >>> order_mock_instance.get_value()
     'third'

     >>> order_mock.get_value.return_value = DEFAULT
     >>> order_mock.get_value()
     'third'

     >>> order_mock.get_value.return_value = "second"
     >>> order_mock.get_value()
     'second'

But if you assign ‘None’ to it, this will not be ignored as it is an
explicit assignment.  So, the order of precedence will not move to the
wrapped object.

     >>> order_mock.get_value.return_value = None
     >>> order_mock.get_value() is None
     True

Even if you set all three at once when initializing the mock, the order
of precedence remains the same:

     >>> order_mock = Mock(spec=Order, wraps=Order,
     ...                   **{"get_value.side_effect": ["first"],
     ...                      "get_value.return_value": "second"}
     ...                   )
     ...
     >>> order_mock.get_value()
     'first'
     >>> order_mock.get_value.side_effect = None
     >>> order_mock.get_value()
     'second'
     >>> order_mock.get_value.return_value = DEFAULT
     >>> order_mock.get_value()
     'third'

If *note side_effect: 4613. is exhausted, the order of precedence will
not cause a value to be obtained from the successors.  Instead,
‘StopIteration’ exception is raised.

     >>> order_mock = Mock(spec=Order, wraps=Order)
     >>> order_mock.get_value.side_effect = ["first side effect value",
     ...                                     "another side effect value"]
     >>> order_mock.get_value.return_value = "second"

     >>> order_mock.get_value()
     'first side effect value'
     >>> order_mock.get_value()
     'another side effect value'

     >>> order_mock.get_value()
     Traceback (most recent call last):
      ...
     StopIteration


File: python.info,  Node: unittest mock — getting started,  Next: test — Regression tests package for Python,  Prev: unittest mock — mock object library,  Up: Development Tools

5.26.7 ‘unittest.mock’ — getting started
----------------------------------------

Added in version 3.3.

* Menu:

* Using Mock::
* Patch Decorators::
* Further Examples::


File: python.info,  Node: Using Mock,  Next: Patch Decorators,  Up: unittest mock — getting started

5.26.7.1 Using Mock
...................

* Menu:

* Mock Patching Methods::
* Mock for Method Calls on an Object::
* Mocking Classes::
* Naming your mocks::
* Tracking all Calls::
* Setting Return Values and Attributes::
* Raising exceptions with mocks::
* Side effect functions and iterables::
* Mocking asynchronous iterators::
* Mocking asynchronous context manager::
* Creating a Mock from an Existing Object::
* Using side_effect to return per file content::


File: python.info,  Node: Mock Patching Methods,  Next: Mock for Method Calls on an Object,  Up: Using Mock

5.26.7.2 Mock Patching Methods
..............................

Common uses for *note Mock: c41. objects include:

   * Patching methods

   * Recording method calls on objects

You might want to replace a method on an object to check that it is
called with the correct arguments by another part of the system:

     >>> real = SomeClass()
     >>> real.method = MagicMock(name='method')
     >>> real.method(3, 4, 5, key='value')
     <MagicMock name='method()' id='...'>

Once our mock has been used (‘real.method’ in this example) it has
methods and attributes that allow you to make assertions about how it
has been used.

     Nota: In most of these examples the *note Mock: c41. and *note
     MagicMock: 1091. classes are interchangeable.  As the ‘MagicMock’
     is the more capable class it makes a sensible one to use by
     default.

Once the mock has been called its *note called: 4625. attribute is set
to ‘True’.  More importantly we can use the *note assert_called_with():
1deb. or *note assert_called_once_with(): 461d. method to check that it
was called with the correct arguments.

This example tests that calling ‘ProductionClass().method’ results in a
call to the ‘something’ method:

     >>> class ProductionClass:
     ...     def method(self):
     ...         self.something(1, 2, 3)
     ...     def something(self, a, b, c):
     ...         pass
     ...
     >>> real = ProductionClass()
     >>> real.something = MagicMock()
     >>> real.method()
     >>> real.something.assert_called_once_with(1, 2, 3)


File: python.info,  Node: Mock for Method Calls on an Object,  Next: Mocking Classes,  Prev: Mock Patching Methods,  Up: Using Mock

5.26.7.3 Mock for Method Calls on an Object
...........................................

In the last example we patched a method directly on an object to check
that it was called correctly.  Another common use case is to pass an
object into a method (or some part of the system under test) and then
check that it is used in the correct way.

The simple ‘ProductionClass’ below has a ‘closer’ method.  If it is
called with an object then it calls ‘close’ on it.

     >>> class ProductionClass:
     ...     def closer(self, something):
     ...         something.close()
     ...

So to test it we need to pass in an object with a ‘close’ method and
check that it was called correctly.

     >>> real = ProductionClass()
     >>> mock = Mock()
     >>> real.closer(mock)
     >>> mock.close.assert_called_with()

We don’t have to do any work to provide the “close” method on our mock.
Accessing close creates it.  So, if “close” hasn’t already been called
then accessing it in the test will create it, but *note
assert_called_with(): 1deb. will raise a failure exception.


File: python.info,  Node: Mocking Classes,  Next: Naming your mocks,  Prev: Mock for Method Calls on an Object,  Up: Using Mock

5.26.7.4 Mocking Classes
........................

A common use case is to mock out classes instantiated by your code under
test.  When you patch a class, then that class is replaced with a mock.
Instances are created by 'calling the class'.  This means you access the
«mock instance» by looking at the return value of the mocked class.

In the example below we have a function ‘some_function’ that
instantiates ‘Foo’ and calls a method on it.  The call to *note patch():
1094. replaces the class ‘Foo’ with a mock.  The ‘Foo’ instance is the
result of calling the mock, so it is configured by modifying the mock
*note return_value: 461b.

     >>> def some_function():
     ...     instance = module.Foo()
     ...     return instance.method()
     ...
     >>> with patch('module.Foo') as mock:
     ...     instance = mock.return_value
     ...     instance.method.return_value = 'the result'
     ...     result = some_function()
     ...     assert result == 'the result'


File: python.info,  Node: Naming your mocks,  Next: Tracking all Calls,  Prev: Mocking Classes,  Up: Using Mock

5.26.7.5 Naming your mocks
..........................

It can be useful to give your mocks a name.  The name is shown in the
repr of the mock and can be helpful when the mock appears in test
failure messages.  The name is also propagated to attributes or methods
of the mock:

     >>> mock = MagicMock(name='foo')
     >>> mock
     <MagicMock name='foo' id='...'>
     >>> mock.method
     <MagicMock name='foo.method' id='...'>


File: python.info,  Node: Tracking all Calls,  Next: Setting Return Values and Attributes,  Prev: Naming your mocks,  Up: Using Mock

5.26.7.6 Tracking all Calls
...........................

Often you want to track more than a single call to a method.  The *note
mock_calls: 461f. attribute records all calls to child attributes of the
mock - and also to their children.

     >>> mock = MagicMock()
     >>> mock.method()
     <MagicMock name='mock.method()' id='...'>
     >>> mock.attribute.method(10, x=53)
     <MagicMock name='mock.attribute.method()' id='...'>
     >>> mock.mock_calls
     [call.method(), call.attribute.method(10, x=53)]

If you make an assertion about ‘mock_calls’ and any unexpected methods
have been called, then the assertion will fail.  This is useful because
as well as asserting that the calls you expected have been made, you are
also checking that they were made in the right order and with no
additional calls:

You use the *note call: 1d9b. object to construct lists for comparing
with ‘mock_calls’:

     >>> expected = [call.method(), call.attribute.method(10, x=53)]
     >>> mock.mock_calls == expected
     True

However, parameters to calls that return mocks are not recorded, which
means it is not possible to track nested calls where the parameters used
to create ancestors are important:

     >>> m = Mock()
     >>> m.factory(important=True).deliver()
     <Mock name='mock.factory().deliver()' id='...'>
     >>> m.mock_calls[-1] == call.factory(important=False).deliver()
     True


File: python.info,  Node: Setting Return Values and Attributes,  Next: Raising exceptions with mocks,  Prev: Tracking all Calls,  Up: Using Mock

5.26.7.7 Setting Return Values and Attributes
.............................................

Setting the return values on a mock object is trivially easy:

     >>> mock = Mock()
     >>> mock.return_value = 3
     >>> mock()
     3

Of course you can do the same for methods on the mock:

     >>> mock = Mock()
     >>> mock.method.return_value = 3
     >>> mock.method()
     3

The return value can also be set in the constructor:

     >>> mock = Mock(return_value=3)
     >>> mock()
     3

If you need an attribute setting on your mock, just do it:

     >>> mock = Mock()
     >>> mock.x = 3
     >>> mock.x
     3

Sometimes you want to mock up a more complex situation, like for example
‘mock.connection.cursor().execute("SELECT 1")’.  If we wanted this call
to return a list, then we have to configure the result of the nested
call.

We can use *note call: 1d9b. to construct the set of calls in a «chained
call» like this for easy assertion afterwards:

     >>> mock = Mock()
     >>> cursor = mock.connection.cursor.return_value
     >>> cursor.execute.return_value = ['foo']
     >>> mock.connection.cursor().execute("SELECT 1")
     ['foo']
     >>> expected = call.connection.cursor().execute("SELECT 1").call_list()
     >>> mock.mock_calls
     [call.connection.cursor(), call.connection.cursor().execute('SELECT 1')]
     >>> mock.mock_calls == expected
     True

It is the call to ‘.call_list()’ that turns our call object into a list
of calls representing the chained calls.


File: python.info,  Node: Raising exceptions with mocks,  Next: Side effect functions and iterables,  Prev: Setting Return Values and Attributes,  Up: Using Mock

5.26.7.8 Raising exceptions with mocks
......................................

A useful attribute is *note side_effect: 4613.  If you set this to an
exception class or instance then the exception will be raised when the
mock is called.

     >>> mock = Mock(side_effect=Exception('Boom!'))
     >>> mock()
     Traceback (most recent call last):
       ...
     Exception: Boom!


File: python.info,  Node: Side effect functions and iterables,  Next: Mocking asynchronous iterators,  Prev: Raising exceptions with mocks,  Up: Using Mock

5.26.7.9 Side effect functions and iterables
............................................

‘side_effect’ can also be set to a function or an iterable.  The use
case for ‘side_effect’ as an iterable is where your mock is going to be
called several times, and you want each call to return a different
value.  When you set ‘side_effect’ to an iterable every call to the mock
returns the next value from the iterable:

     >>> mock = MagicMock(side_effect=[4, 5, 6])
     >>> mock()
     4
     >>> mock()
     5
     >>> mock()
     6

For more advanced use cases, like dynamically varying the return values
depending on what the mock is called with, ‘side_effect’ can be a
function.  The function will be called with the same arguments as the
mock.  Whatever the function returns is what the call returns:

     >>> vals = {(1, 2): 1, (2, 3): 2}
     >>> def side_effect(*args):
     ...     return vals[args]
     ...
     >>> mock = MagicMock(side_effect=side_effect)
     >>> mock(1, 2)
     1
     >>> mock(2, 3)
     2


File: python.info,  Node: Mocking asynchronous iterators,  Next: Mocking asynchronous context manager,  Prev: Side effect functions and iterables,  Up: Using Mock

5.26.7.10 Mocking asynchronous iterators
........................................

Since Python 3.8, ‘AsyncMock’ and ‘MagicMock’ have support to mock *note
Asynchronous Iterators: f79. through ‘__aiter__’.  The *note
return_value: 461b. attribute of ‘__aiter__’ can be used to set the
return values to be used for iteration.

     >>> mock = MagicMock()  # AsyncMock also works here
     >>> mock.__aiter__.return_value = [1, 2, 3]
     >>> async def main():
     ...     return [i async for i in mock]
     ...
     >>> asyncio.run(main())
     [1, 2, 3]


File: python.info,  Node: Mocking asynchronous context manager,  Next: Creating a Mock from an Existing Object,  Prev: Mocking asynchronous iterators,  Up: Using Mock

5.26.7.11 Mocking asynchronous context manager
..............................................

Since Python 3.8, ‘AsyncMock’ and ‘MagicMock’ have support to mock *note
Asynchronous Context Managers: 813. through ‘__aenter__’ and
‘__aexit__’.  By default, ‘__aenter__’ and ‘__aexit__’ are ‘AsyncMock’
instances that return an async function.

     >>> class AsyncContextManager:
     ...     async def __aenter__(self):
     ...         return self
     ...     async def __aexit__(self, exc_type, exc, tb):
     ...         pass
     ...
     >>> mock_instance = MagicMock(AsyncContextManager())  # AsyncMock also works here
     >>> async def main():
     ...     async with mock_instance as result:
     ...         pass
     ...
     >>> asyncio.run(main())
     >>> mock_instance.__aenter__.assert_awaited_once()
     >>> mock_instance.__aexit__.assert_awaited_once()


File: python.info,  Node: Creating a Mock from an Existing Object,  Next: Using side_effect to return per file content,  Prev: Mocking asynchronous context manager,  Up: Using Mock

5.26.7.12 Creating a Mock from an Existing Object
.................................................

One problem with over use of mocking is that it couples your tests to
the implementation of your mocks rather than your real code.  Suppose
you have a class that implements ‘some_method’.  In a test for another
class, you provide a mock of this object that 'also' provides
‘some_method’.  If later you refactor the first class, so that it no
longer has ‘some_method’ - then your tests will continue to pass even
though your code is now broken!

*note Mock: c41. allows you to provide an object as a specification for
the mock, using the 'spec' keyword argument.  Accessing methods /
attributes on the mock that don’t exist on your specification object
will immediately raise an attribute error.  If you change the
implementation of your specification, then tests that use that class
will start failing immediately without you having to instantiate the
class in those tests.

     >>> mock = Mock(spec=SomeClass)
     >>> mock.old_method()
     Traceback (most recent call last):
        ...
     AttributeError: Mock object has no attribute 'old_method'. Did you mean: 'class_method'?

Using a specification also enables a smarter matching of calls made to
the mock, regardless of whether some parameters were passed as
positional or named arguments:

     >>> def f(a, b, c): pass
     ...
     >>> mock = Mock(spec=f)
     >>> mock(1, 2, 3)
     <Mock name='mock()' id='140161580456576'>
     >>> mock.assert_called_with(a=1, b=2, c=3)

If you want this smarter matching to also work with method calls on the
mock, you can use *note auto-speccing: 4616.

If you want a stronger form of specification that prevents the setting
of arbitrary attributes as well as the getting of them then you can use
'spec_set' instead of 'spec'.


File: python.info,  Node: Using side_effect to return per file content,  Prev: Creating a Mock from an Existing Object,  Up: Using Mock

5.26.7.13 Using side_effect to return per file content
......................................................

*note mock_open(): 11e9. is used to patch *note open(): 316. method.
*note side_effect: 4613. can be used to return a new Mock object per
call.  This can be used to return different contents per file stored in
a dictionary:

     DEFAULT = "default"
     data_dict = {"file1": "data1",
                  "file2": "data2"}

     def open_side_effect(name):
         return mock_open(read_data=data_dict.get(name, DEFAULT))()

     with patch("builtins.open", side_effect=open_side_effect):
         with open("file1") as file1:
             assert file1.read() == "data1"

         with open("file2") as file2:
             assert file2.read() == "data2"

         with open("file3") as file2:
             assert file2.read() == "default"


File: python.info,  Node: Patch Decorators,  Next: Further Examples,  Prev: Using Mock,  Up: unittest mock — getting started

5.26.7.14 Patch Decorators
..........................

     Nota: With *note patch(): 1094. it matters that you patch objects
     in the namespace where they are looked up.  This is normally
     straightforward, but for a quick guide read *note where to patch:
     4614.

A common need in tests is to patch a class attribute or a module
attribute, for example patching a builtin or patching a class in a
module to test that it is instantiated.  Modules and classes are
effectively global, so patching on them has to be undone after the test
or the patch will persist into other tests and cause hard to diagnose
problems.

mock provides three convenient decorators for this: *note patch(): 1094,
*note patch.object(): 18ee. and *note patch.dict(): 194f.  ‘patch’ takes
a single string, of the form ‘package.module.Class.attribute’ to specify
the attribute you are patching.  It also optionally takes a value that
you want the attribute (or class or whatever) to be replaced with.
“patch.object” takes an object and the name of the attribute you would
like patched, plus optionally the value to patch it with.

‘patch.object’:

     >>> original = SomeClass.attribute
     >>> @patch.object(SomeClass, 'attribute', sentinel.attribute)
     ... def test():
     ...     assert SomeClass.attribute == sentinel.attribute
     ...
     >>> test()
     >>> assert SomeClass.attribute == original

     >>> @patch('package.module.attribute', sentinel.attribute)
     ... def test():
     ...     from package.module import attribute
     ...     assert attribute is sentinel.attribute
     ...
     >>> test()

If you are patching a module (including *note builtins: 13.) then use
*note patch(): 1094. instead of *note patch.object(): 18ee.:

     >>> mock = MagicMock(return_value=sentinel.file_handle)
     >>> with patch('builtins.open', mock):
     ...     handle = open('filename', 'r')
     ...
     >>> mock.assert_called_with('filename', 'r')
     >>> assert handle == sentinel.file_handle, "incorrect file handle returned"

The module name can be “dotted”, in the form ‘package.module’ if needed:

     >>> @patch('package.module.ClassName.attribute', sentinel.attribute)
     ... def test():
     ...     from package.module import ClassName
     ...     assert ClassName.attribute == sentinel.attribute
     ...
     >>> test()

A nice pattern is to actually decorate test methods themselves:

     >>> class MyTest(unittest.TestCase):
     ...     @patch.object(SomeClass, 'attribute', sentinel.attribute)
     ...     def test_something(self):
     ...         self.assertEqual(SomeClass.attribute, sentinel.attribute)
     ...
     >>> original = SomeClass.attribute
     >>> MyTest('test_something').test_something()
     >>> assert SomeClass.attribute == original

If you want to patch with a Mock, you can use *note patch(): 1094. with
only one argument (or *note patch.object(): 18ee. with two arguments).
The mock will be created for you and passed into the test function /
method:

     >>> class MyTest(unittest.TestCase):
     ...     @patch.object(SomeClass, 'static_method')
     ...     def test_something(self, mock_method):
     ...         SomeClass.static_method()
     ...         mock_method.assert_called_with()
     ...
     >>> MyTest('test_something').test_something()

You can stack up multiple patch decorators using this pattern:

     >>> class MyTest(unittest.TestCase):
     ...     @patch('package.module.ClassName1')
     ...     @patch('package.module.ClassName2')
     ...     def test_something(self, MockClass2, MockClass1):
     ...         self.assertIs(package.module.ClassName1, MockClass1)
     ...         self.assertIs(package.module.ClassName2, MockClass2)
     ...
     >>> MyTest('test_something').test_something()

When you nest patch decorators the mocks are passed in to the decorated
function in the same order they applied (the normal 'Python' order that
decorators are applied).  This means from the bottom up, so in the
example above the mock for ‘test_module.ClassName2’ is passed in first.

There is also *note patch.dict(): 194f. for setting values in a
dictionary just during a scope and restoring the dictionary to its
original state when the test ends:

     >>> foo = {'key': 'value'}
     >>> original = foo.copy()
     >>> with patch.dict(foo, {'newkey': 'newvalue'}, clear=True):
     ...     assert foo == {'newkey': 'newvalue'}
     ...
     >>> assert foo == original

‘patch’, ‘patch.object’ and ‘patch.dict’ can all be used as context
managers.

Where you use *note patch(): 1094. to create a mock for you, you can get
a reference to the mock using the «as» form of the with statement:

     >>> class ProductionClass:
     ...     def method(self):
     ...         pass
     ...
     >>> with patch.object(ProductionClass, 'method') as mock_method:
     ...     mock_method.return_value = None
     ...     real = ProductionClass()
     ...     real.method(1, 2, 3)
     ...
     >>> mock_method.assert_called_with(1, 2, 3)

As an alternative ‘patch’, ‘patch.object’ and ‘patch.dict’ can be used
as class decorators.  When used in this way it is the same as applying
the decorator individually to every method whose name starts with
«test».


File: python.info,  Node: Further Examples,  Prev: Patch Decorators,  Up: unittest mock — getting started

5.26.7.15 Further Examples
..........................

Here are some more examples for some slightly more advanced scenarios.

* Menu:

* Mocking chained calls::
* Partial mocking::
* Mocking a Generator Method::
* Applying the same patch to every test method::
* Mocking Unbound Methods::
* Checking multiple calls with mock::
* Coping with mutable arguments::
* Nesting Patches::
* Mocking a dictionary with MagicMock::
* Mock subclasses and their attributes::
* Mocking imports with patch.dict: Mocking imports with patch dict.
* Tracking order of calls and less verbose call assertions::
* More complex argument matching::


File: python.info,  Node: Mocking chained calls,  Next: Partial mocking,  Up: Further Examples

5.26.7.16 Mocking chained calls
...............................

Mocking chained calls is actually straightforward with mock once you
understand the *note return_value: 461b. attribute.  When a mock is
called for the first time, or you fetch its ‘return_value’ before it has
been called, a new *note Mock: c41. is created.

This means that you can see how the object returned from a call to a
mocked object has been used by interrogating the ‘return_value’ mock:

     >>> mock = Mock()
     >>> mock().foo(a=2, b=3)
     <Mock name='mock().foo()' id='...'>
     >>> mock.return_value.foo.assert_called_with(a=2, b=3)

From here it is a simple step to configure and then make assertions
about chained calls.  Of course another alternative is writing your code
in a more testable way in the first place…

So, suppose we have some code that looks a little bit like this:

     >>> class Something:
     ...     def __init__(self):
     ...         self.backend = BackendProvider()
     ...     def method(self):
     ...         response = self.backend.get_endpoint('foobar').create_call('spam', 'eggs').start_call()
     ...         # more code

Assuming that ‘BackendProvider’ is already well tested, how do we test
‘method()’?  Specifically, we want to test that the code section ‘# more
code’ uses the response object in the correct way.

As this chain of calls is made from an instance attribute we can monkey
patch the ‘backend’ attribute on a ‘Something’ instance.  In this
particular case we are only interested in the return value from the
final call to ‘start_call’ so we don’t have much configuration to do.
Let’s assume the object it returns is “file-like”, so we’ll ensure that
our response object uses the builtin *note open(): 316. as its ‘spec’.

To do this we create a mock instance as our mock backend and create a
mock response object for it.  To set the response as the return value
for that final ‘start_call’ we could do this:

     mock_backend.get_endpoint.return_value.create_call.return_value.start_call.return_value = mock_response

We can do that in a slightly nicer way using the *note configure_mock():
461c. method to directly set the return value for us:

     >>> something = Something()
     >>> mock_response = Mock(spec=open)
     >>> mock_backend = Mock()
     >>> config = {'get_endpoint.return_value.create_call.return_value.start_call.return_value': mock_response}
     >>> mock_backend.configure_mock(**config)

With these we monkey patch the «mock backend» in place and can make the
real call:

     >>> something.backend = mock_backend
     >>> something.method()

Using *note mock_calls: 461f. we can check the chained call with a
single assert.  A chained call is several calls in one line of code, so
there will be several entries in ‘mock_calls’.  We can use *note
call.call_list(): 4655. to create this list of calls for us:

     >>> chained = call.get_endpoint('foobar').create_call('spam', 'eggs').start_call()
     >>> call_list = chained.call_list()
     >>> assert mock_backend.mock_calls == call_list


File: python.info,  Node: Partial mocking,  Next: Mocking a Generator Method,  Prev: Mocking chained calls,  Up: Further Examples

5.26.7.17 Partial mocking
.........................

For some tests, you may want to mock out a call to *note
datetime.date.today(): 16d1. to return a known date, but don’t want to
prevent the code under test from creating new date objects.
Unfortunately *note datetime.date: 1fa. is written in C, so you cannot
just monkey-patch out the static *note datetime.date.today(): 16d1.
method.

Instead, you can effectively wrap the date class with a mock, while
passing through calls to the constructor to the real class (and
returning real instances).

The *note patch decorator: 1094. is used here to mock out the ‘date’
class in the module under test.  The *note side_effect: 4613. attribute
on the mock date class is then set to a lambda function that returns a
real date.  When the mock date class is called a real date will be
constructed and returned by ‘side_effect’.

     >>> from datetime import date
     >>> with patch('mymodule.date') as mock_date:
     ...     mock_date.today.return_value = date(2010, 10, 8)
     ...     mock_date.side_effect = lambda *args, **kw: date(*args, **kw)
     ...
     ...     assert mymodule.date.today() == date(2010, 10, 8)
     ...     assert mymodule.date(2009, 6, 8) == date(2009, 6, 8)

Note that we don’t patch *note datetime.date: 1fa. globally, we patch
‘date’ in the module that 'uses' it.  See *note where to patch: 4614.

When ‘date.today()’ is called a known date is returned, but calls to the
‘date(...)’ constructor still return normal dates.  Without this you can
find yourself having to calculate an expected result using exactly the
same algorithm as the code under test, which is a classic testing
anti-pattern.

Calls to the date constructor are recorded in the ‘mock_date’ attributes
(‘call_count’ and friends) which may also be useful for your tests.

An alternative way of dealing with mocking dates, or other builtin
classes, is discussed in this blog entry(1).

   ---------- Footnotes ----------

   (1) 
https://williambert.online/2011/07/how-to-unit-testing-in-django-with-mocking-and-patching/


File: python.info,  Node: Mocking a Generator Method,  Next: Applying the same patch to every test method,  Prev: Partial mocking,  Up: Further Examples

5.26.7.18 Mocking a Generator Method
....................................

A Python generator is a function or method that uses the *note yield:
bc4. statement to return a series of values when iterated over (1).

A generator method / function is called to return the generator object.
It is the generator object that is then iterated over.  The protocol
method for iteration is *note __iter__(): 2094, so we can mock this
using a *note MagicMock: 1091.

Here’s an example class with an «iter» method implemented as a
generator:

     >>> class Foo:
     ...     def iter(self):
     ...         for i in [1, 2, 3]:
     ...             yield i
     ...
     >>> foo = Foo()
     >>> list(foo.iter())
     [1, 2, 3]

How would we mock this class, and in particular its «iter» method?

To configure the values returned from the iteration (implicit in the
call to *note list: 24d.), we need to configure the object returned by
the call to ‘foo.iter()’.

     >>> mock_foo = MagicMock()
     >>> mock_foo.iter.return_value = iter([1, 2, 3])
     >>> list(mock_foo.iter())
     [1, 2, 3]

   ---------- Footnotes ----------

   (1) There are also generator expressions and more advanced uses
(http://www.dabeaz.com/coroutines/index.html) of generators, but we
aren’t concerned about them here.  A very good introduction to
generators and how powerful they are is: Generator Tricks for Systems
Programmers (http://www.dabeaz.com/generators/).


File: python.info,  Node: Applying the same patch to every test method,  Next: Mocking Unbound Methods,  Prev: Mocking a Generator Method,  Up: Further Examples

5.26.7.19 Applying the same patch to every test method
......................................................

If you want several patches in place for multiple test methods the
obvious way is to apply the patch decorators to every method.  This can
feel like unnecessary repetition.  Instead, you can use *note patch():
1094. (in all its various forms) as a class decorator.  This applies the
patches to all test methods on the class.  A test method is identified
by methods whose names start with ‘test’:

     >>> @patch('mymodule.SomeClass')
     ... class MyTest(unittest.TestCase):
     ...
     ...     def test_one(self, MockSomeClass):
     ...         self.assertIs(mymodule.SomeClass, MockSomeClass)
     ...
     ...     def test_two(self, MockSomeClass):
     ...         self.assertIs(mymodule.SomeClass, MockSomeClass)
     ...
     ...     def not_a_test(self):
     ...         return 'something'
     ...
     >>> MyTest('test_one').test_one()
     >>> MyTest('test_two').test_two()
     >>> MyTest('test_two').not_a_test()
     'something'

An alternative way of managing patches is to use the *note patch
methods; start and stop: 4646.  These allow you to move the patching
into your ‘setUp’ and ‘tearDown’ methods.

     >>> class MyTest(unittest.TestCase):
     ...     def setUp(self):
     ...         self.patcher = patch('mymodule.foo')
     ...         self.mock_foo = self.patcher.start()
     ...
     ...     def test_foo(self):
     ...         self.assertIs(mymodule.foo, self.mock_foo)
     ...
     ...     def tearDown(self):
     ...         self.patcher.stop()
     ...
     >>> MyTest('test_foo').run()

If you use this technique you must ensure that the patching is «undone»
by calling ‘stop’.  This can be fiddlier than you might think, because
if an exception is raised in the setUp then tearDown is not called.
*note unittest.TestCase.addCleanup(): c76. makes this easier:

     >>> class MyTest(unittest.TestCase):
     ...     def setUp(self):
     ...         patcher = patch('mymodule.foo')
     ...         self.addCleanup(patcher.stop)
     ...         self.mock_foo = patcher.start()
     ...
     ...     def test_foo(self):
     ...         self.assertIs(mymodule.foo, self.mock_foo)
     ...
     >>> MyTest('test_foo').run()


File: python.info,  Node: Mocking Unbound Methods,  Next: Checking multiple calls with mock,  Prev: Applying the same patch to every test method,  Up: Further Examples

5.26.7.20 Mocking Unbound Methods
.................................

Sometimes a test needs to patch an 'unbound method', which means
patching the method on the class rather than on the instance.  In order
to make assertions about which objects were calling this particular
method, you need to pass ‘self’ as the first argument.  The issue is
that you can’t patch with a mock for this, because if you replace an
unbound method with a mock it doesn’t become a bound method when fetched
from the instance, and so it doesn’t get ‘self’ passed in.  The
workaround is to patch the unbound method with a real function instead.
The *note patch(): 1094. decorator makes it so simple to patch out
methods with a mock that having to create a real function becomes a
nuisance.

If you pass ‘autospec=True’ to patch then it does the patching with a
'real' function object.  This function object has the same signature as
the one it is replacing, but delegates to a mock under the hood.  You
still get your mock auto-created in exactly the same way as before.
What it means though, is that if you use it to patch out an unbound
method on a class the mocked function will be turned into a bound method
if it is fetched from an instance.  It will have ‘self’ passed in as the
first argument, which is exactly what was needed:

     >>> class Foo:
     ...   def foo(self):
     ...     pass
     ...
     >>> with patch.object(Foo, 'foo', autospec=True) as mock_foo:
     ...   mock_foo.return_value = 'foo'
     ...   foo = Foo()
     ...   foo.foo()
     ...
     'foo'
     >>> mock_foo.assert_called_once_with(foo)

If we don’t use ‘autospec=True’ then the unbound method is patched out
with a Mock instance instead, and isn’t called with ‘self’.


File: python.info,  Node: Checking multiple calls with mock,  Next: Coping with mutable arguments,  Prev: Mocking Unbound Methods,  Up: Further Examples

5.26.7.21 Checking multiple calls with mock
...........................................

mock has a nice API for making assertions about how your mock objects
are used.

     >>> mock = Mock()
     >>> mock.foo_bar.return_value = None
     >>> mock.foo_bar('baz', spam='eggs')
     >>> mock.foo_bar.assert_called_with('baz', spam='eggs')

If your mock is only being called once you can use the *note
assert_called_once_with(): 461d. method that also asserts that the *note
call_count: 176a. is one.

     >>> mock.foo_bar.assert_called_once_with('baz', spam='eggs')
     >>> mock.foo_bar()
     >>> mock.foo_bar.assert_called_once_with('baz', spam='eggs')
     Traceback (most recent call last):
         ...
     AssertionError: Expected 'foo_bar' to be called once. Called 2 times.
     Calls: [call('baz', spam='eggs'), call()].

Both ‘assert_called_with’ and ‘assert_called_once_with’ make assertions
about the 'most recent' call.  If your mock is going to be called
several times, and you want to make assertions about 'all' those calls
you can use *note call_args_list: 4626.:

     >>> mock = Mock(return_value=None)
     >>> mock(1, 2, 3)
     >>> mock(4, 5, 6)
     >>> mock()
     >>> mock.call_args_list
     [call(1, 2, 3), call(4, 5, 6), call()]

The *note call: 1d9b. helper makes it easy to make assertions about
these calls.  You can build up a list of expected calls and compare it
to ‘call_args_list’.  This looks remarkably similar to the repr of the
‘call_args_list’:

     >>> expected = [call(1, 2, 3), call(4, 5, 6), call()]
     >>> mock.call_args_list == expected
     True


File: python.info,  Node: Coping with mutable arguments,  Next: Nesting Patches,  Prev: Checking multiple calls with mock,  Up: Further Examples

5.26.7.22 Coping with mutable arguments
.......................................

Another situation is rare, but can bite you, is when your mock is called
with mutable arguments.  ‘call_args’ and ‘call_args_list’ store
'references' to the arguments.  If the arguments are mutated by the code
under test then you can no longer make assertions about what the values
were when the mock was called.

Here’s some example code that shows the problem.  Imagine the following
functions defined in “mymodule”:

     def frob(val):
         pass

     def grob(val):
         "First frob and then clear val"
         frob(val)
         val.clear()

When we try to test that ‘grob’ calls ‘frob’ with the correct argument
look what happens:

     >>> with patch('mymodule.frob') as mock_frob:
     ...     val = {6}
     ...     mymodule.grob(val)
     ...
     >>> val
     set()
     >>> mock_frob.assert_called_with({6})
     Traceback (most recent call last):
         ...
     AssertionError: Expected: (({6},), {})
     Called with: ((set(),), {})

One possibility would be for mock to copy the arguments you pass in.
This could then cause problems if you do assertions that rely on object
identity for equality.

Here’s one solution that uses the *note side_effect: 4613.
functionality.  If you provide a ‘side_effect’ function for a mock then
‘side_effect’ will be called with the same args as the mock.  This gives
us an opportunity to copy the arguments and store them for later
assertions.  In this example I’m using 'another' mock to store the
arguments so that I can use the mock methods for doing the assertion.
Again a helper function sets this up for me.

     >>> from copy import deepcopy
     >>> from unittest.mock import Mock, patch, DEFAULT
     >>> def copy_call_args(mock):
     ...     new_mock = Mock()
     ...     def side_effect(*args, **kwargs):
     ...         args = deepcopy(args)
     ...         kwargs = deepcopy(kwargs)
     ...         new_mock(*args, **kwargs)
     ...         return DEFAULT
     ...     mock.side_effect = side_effect
     ...     return new_mock
     ...
     >>> with patch('mymodule.frob') as mock_frob:
     ...     new_mock = copy_call_args(mock_frob)
     ...     val = {6}
     ...     mymodule.grob(val)
     ...
     >>> new_mock.assert_called_with({6})
     >>> new_mock.call_args
     call({6})

‘copy_call_args’ is called with the mock that will be called.  It
returns a new mock that we do the assertion on.  The ‘side_effect’
function makes a copy of the args and calls our ‘new_mock’ with the
copy.

     Nota: If your mock is only going to be used once there is an easier
     way of checking arguments at the point they are called.  You can
     simply do the checking inside a ‘side_effect’ function.

          >>> def side_effect(arg):
          ...     assert arg == {6}
          ...
          >>> mock = Mock(side_effect=side_effect)
          >>> mock({6})
          >>> mock(set())
          Traceback (most recent call last):
              ...
          AssertionError

An alternative approach is to create a subclass of *note Mock: c41. or
*note MagicMock: 1091. that copies (using *note copy.deepcopy(): d67.)
the arguments.  Here’s an example implementation:

     >>> from copy import deepcopy
     >>> class CopyingMock(MagicMock):
     ...     def __call__(self, /, *args, **kwargs):
     ...         args = deepcopy(args)
     ...         kwargs = deepcopy(kwargs)
     ...         return super().__call__(*args, **kwargs)
     ...
     >>> c = CopyingMock(return_value=None)
     >>> arg = set()
     >>> c(arg)
     >>> arg.add(1)
     >>> c.assert_called_with(set())
     >>> c.assert_called_with(arg)
     Traceback (most recent call last):
         ...
     AssertionError: expected call not found.
     Expected: mock({1})
     Actual: mock(set())
     >>> c.foo
     <CopyingMock name='mock.foo' id='...'>

When you subclass ‘Mock’ or ‘MagicMock’ all dynamically created
attributes, and the ‘return_value’ will use your subclass automatically.
That means all children of a ‘CopyingMock’ will also have the type
‘CopyingMock’.


File: python.info,  Node: Nesting Patches,  Next: Mocking a dictionary with MagicMock,  Prev: Coping with mutable arguments,  Up: Further Examples

5.26.7.23 Nesting Patches
.........................

Using patch as a context manager is nice, but if you do multiple patches
you can end up with nested with statements indenting further and further
to the right:

     >>> class MyTest(unittest.TestCase):
     ...
     ...     def test_foo(self):
     ...         with patch('mymodule.Foo') as mock_foo:
     ...             with patch('mymodule.Bar') as mock_bar:
     ...                 with patch('mymodule.Spam') as mock_spam:
     ...                     assert mymodule.Foo is mock_foo
     ...                     assert mymodule.Bar is mock_bar
     ...                     assert mymodule.Spam is mock_spam
     ...
     >>> original = mymodule.Foo
     >>> MyTest('test_foo').test_foo()
     >>> assert mymodule.Foo is original

With unittest ‘cleanup’ functions and the *note patch methods; start and
stop: 4646. we can achieve the same effect without the nested
indentation.  A simple helper method, ‘create_patch’, puts the patch in
place and returns the created mock for us:

     >>> class MyTest(unittest.TestCase):
     ...
     ...     def create_patch(self, name):
     ...         patcher = patch(name)
     ...         thing = patcher.start()
     ...         self.addCleanup(patcher.stop)
     ...         return thing
     ...
     ...     def test_foo(self):
     ...         mock_foo = self.create_patch('mymodule.Foo')
     ...         mock_bar = self.create_patch('mymodule.Bar')
     ...         mock_spam = self.create_patch('mymodule.Spam')
     ...
     ...         assert mymodule.Foo is mock_foo
     ...         assert mymodule.Bar is mock_bar
     ...         assert mymodule.Spam is mock_spam
     ...
     >>> original = mymodule.Foo
     >>> MyTest('test_foo').run()
     >>> assert mymodule.Foo is original


File: python.info,  Node: Mocking a dictionary with MagicMock,  Next: Mock subclasses and their attributes,  Prev: Nesting Patches,  Up: Further Examples

5.26.7.24 Mocking a dictionary with MagicMock
.............................................

You may want to mock a dictionary, or other container object, recording
all access to it whilst having it still behave like a dictionary.

We can do this with *note MagicMock: 1091, which will behave like a
dictionary, and using *note side_effect: 4613. to delegate dictionary
access to a real underlying dictionary that is under our control.

When the *note __getitem__(): 588. and *note __setitem__(): 14d3.
methods of our ‘MagicMock’ are called (normal dictionary access) then
‘side_effect’ is called with the key (and in the case of ‘__setitem__’
the value too).  We can also control what is returned.

After the ‘MagicMock’ has been used we can use attributes like *note
call_args_list: 4626. to assert about how the dictionary was used:

     >>> my_dict = {'a': 1, 'b': 2, 'c': 3}
     >>> def getitem(name):
     ...      return my_dict[name]
     ...
     >>> def setitem(name, val):
     ...     my_dict[name] = val
     ...
     >>> mock = MagicMock()
     >>> mock.__getitem__.side_effect = getitem
     >>> mock.__setitem__.side_effect = setitem

     Nota: An alternative to using ‘MagicMock’ is to use ‘Mock’ and
     'only' provide the magic methods you specifically want:

          >>> mock = Mock()
          >>> mock.__getitem__ = Mock(side_effect=getitem)
          >>> mock.__setitem__ = Mock(side_effect=setitem)

     A 'third' option is to use ‘MagicMock’ but passing in ‘dict’ as the
     'spec' (or 'spec_set') argument so that the ‘MagicMock’ created
     only has dictionary magic methods available:

          >>> mock = MagicMock(spec_set=dict)
          >>> mock.__getitem__.side_effect = getitem
          >>> mock.__setitem__.side_effect = setitem

With these side effect functions in place, the ‘mock’ will behave like a
normal dictionary but recording the access.  It even raises a *note
KeyError: 5e7. if you try to access a key that doesn’t exist.

     >>> mock['a']
     1
     >>> mock['c']
     3
     >>> mock['d']
     Traceback (most recent call last):
         ...
     KeyError: 'd'
     >>> mock['b'] = 'fish'
     >>> mock['d'] = 'eggs'
     >>> mock['b']
     'fish'
     >>> mock['d']
     'eggs'

After it has been used you can make assertions about the access using
the normal mock methods and attributes:

     >>> mock.__getitem__.call_args_list
     [call('a'), call('c'), call('d'), call('b'), call('d')]
     >>> mock.__setitem__.call_args_list
     [call('b', 'fish'), call('d', 'eggs')]
     >>> my_dict
     {'a': 1, 'b': 'fish', 'c': 3, 'd': 'eggs'}


File: python.info,  Node: Mock subclasses and their attributes,  Next: Mocking imports with patch dict,  Prev: Mocking a dictionary with MagicMock,  Up: Further Examples

5.26.7.25 Mock subclasses and their attributes
..............................................

There are various reasons why you might want to subclass *note Mock:
c41.  One reason might be to add helper methods.  Here’s a silly
example:

     >>> class MyMock(MagicMock):
     ...     def has_been_called(self):
     ...         return self.called
     ...
     >>> mymock = MyMock(return_value=None)
     >>> mymock
     <MyMock id='...'>
     >>> mymock.has_been_called()
     False
     >>> mymock()
     >>> mymock.has_been_called()
     True

The standard behaviour for ‘Mock’ instances is that attributes and the
return value mocks are of the same type as the mock they are accessed
on.  This ensures that ‘Mock’ attributes are ‘Mocks’ and ‘MagicMock’
attributes are ‘MagicMocks’ (1).  So if you’re subclassing to add helper
methods then they’ll also be available on the attributes and return
value mock of instances of your subclass.

     >>> mymock.foo
     <MyMock name='mock.foo' id='...'>
     >>> mymock.foo.has_been_called()
     False
     >>> mymock.foo()
     <MyMock name='mock.foo()' id='...'>
     >>> mymock.foo.has_been_called()
     True

Sometimes this is inconvenient.  For example, one user(2) is subclassing
mock to created a Twisted adaptor(3).  Having this applied to attributes
too actually causes errors.

‘Mock’ (in all its flavours) uses a method called ‘_get_child_mock’ to
create these «sub-mocks» for attributes and return values.  You can
prevent your subclass being used for attributes by overriding this
method.  The signature is that it takes arbitrary keyword arguments
(‘**kwargs’) which are then passed onto the mock constructor:

     >>> class Subclass(MagicMock):
     ...     def _get_child_mock(self, /, **kwargs):
     ...         return MagicMock(**kwargs)
     ...
     >>> mymock = Subclass()
     >>> mymock.foo
     <MagicMock name='mock.foo' id='...'>
     >>> assert isinstance(mymock, Subclass)
     >>> assert not isinstance(mymock.foo, Subclass)
     >>> assert not isinstance(mymock(), Subclass)

   ---------- Footnotes ----------

   (1) An exception to this rule are the non-callable mocks.  Attributes
use the callable variant because otherwise non-callable mocks couldn’t
have callable methods.

   (2) https://code.google.com/archive/p/mock/issues/105

   (3) 
https://twisted.org/documents/11.0.0/api/twisted.python.components.html


File: python.info,  Node: Mocking imports with patch dict,  Next: Tracking order of calls and less verbose call assertions,  Prev: Mock subclasses and their attributes,  Up: Further Examples

5.26.7.26 Mocking imports with patch.dict
.........................................

One situation where mocking can be hard is where you have a local import
inside a function.  These are harder to mock because they aren’t using
an object from the module namespace that we can patch out.

Generally local imports are to be avoided.  They are sometimes done to
prevent circular dependencies, for which there is 'usually' a much
better way to solve the problem (refactor the code) or to prevent «up
front costs» by delaying the import.  This can also be solved in better
ways than an unconditional local import (store the module as a class or
module attribute and only do the import on first use).

That aside there is a way to use ‘mock’ to affect the results of an
import.  Importing fetches an 'object' from the *note sys.modules: 17ce.
dictionary.  Note that it fetches an 'object', which need not be a
module.  Importing a module for the first time results in a module
object being put in ‘sys.modules’, so usually when you import something
you get a module back.  This need not be the case however.

This means you can use *note patch.dict(): 194f. to 'temporarily' put a
mock in place in *note sys.modules: 17ce.  Any imports whilst this patch
is active will fetch the mock.  When the patch is complete (the
decorated function exits, the with statement body is complete or
‘patcher.stop()’ is called) then whatever was there previously will be
restored safely.

Here’s an example that mocks out the “fooble” module.

     >>> import sys
     >>> mock = Mock()
     >>> with patch.dict('sys.modules', {'fooble': mock}):
     ...    import fooble
     ...    fooble.blob()
     ...
     <Mock name='mock.blob()' id='...'>
     >>> assert 'fooble' not in sys.modules
     >>> mock.blob.assert_called_once_with()

As you can see the ‘import fooble’ succeeds, but on exit there is no
“fooble” left in *note sys.modules: 17ce.

This also works for the ‘from module import name’ form:

     >>> mock = Mock()
     >>> with patch.dict('sys.modules', {'fooble': mock}):
     ...    from fooble import blob
     ...    blob.blip()
     ...
     <Mock name='mock.blob.blip()' id='...'>
     >>> mock.blob.blip.assert_called_once_with()

With slightly more work you can also mock package imports:

     >>> mock = Mock()
     >>> modules = {'package': mock, 'package.module': mock.module}
     >>> with patch.dict('sys.modules', modules):
     ...    from package.module import fooble
     ...    fooble()
     ...
     <Mock name='mock.module.fooble()' id='...'>
     >>> mock.module.fooble.assert_called_once_with()


File: python.info,  Node: Tracking order of calls and less verbose call assertions,  Next: More complex argument matching,  Prev: Mocking imports with patch dict,  Up: Further Examples

5.26.7.27 Tracking order of calls and less verbose call assertions
..................................................................

The *note Mock: c41. class allows you to track the 'order' of method
calls on your mock objects through the *note method_calls: 4621.
attribute.  This doesn’t allow you to track the order of calls between
separate mock objects, however we can use *note mock_calls: 461f. to
achieve the same effect.

Because mocks track calls to child mocks in ‘mock_calls’, and accessing
an arbitrary attribute of a mock creates a child mock, we can create our
separate mocks from a parent one.  Calls to those child mock will then
all be recorded, in order, in the ‘mock_calls’ of the parent:

     >>> manager = Mock()
     >>> mock_foo = manager.foo
     >>> mock_bar = manager.bar

     >>> mock_foo.something()
     <Mock name='mock.foo.something()' id='...'>
     >>> mock_bar.other.thing()
     <Mock name='mock.bar.other.thing()' id='...'>

     >>> manager.mock_calls
     [call.foo.something(), call.bar.other.thing()]

We can then assert about the calls, including the order, by comparing
with the ‘mock_calls’ attribute on the manager mock:

     >>> expected_calls = [call.foo.something(), call.bar.other.thing()]
     >>> manager.mock_calls == expected_calls
     True

If ‘patch’ is creating, and putting in place, your mocks then you can
attach them to a manager mock using the *note attach_mock(): 193d.
method.  After attaching calls will be recorded in ‘mock_calls’ of the
manager.

     >>> manager = MagicMock()
     >>> with patch('mymodule.Class1') as MockClass1:
     ...     with patch('mymodule.Class2') as MockClass2:
     ...         manager.attach_mock(MockClass1, 'MockClass1')
     ...         manager.attach_mock(MockClass2, 'MockClass2')
     ...         MockClass1().foo()
     ...         MockClass2().bar()
     <MagicMock name='mock.MockClass1().foo()' id='...'>
     <MagicMock name='mock.MockClass2().bar()' id='...'>
     >>> manager.mock_calls
     [call.MockClass1(),
     call.MockClass1().foo(),
     call.MockClass2(),
     call.MockClass2().bar()]

If many calls have been made, but you’re only interested in a particular
sequence of them then an alternative is to use the *note
assert_has_calls(): 1a0a. method.  This takes a list of calls
(constructed with the *note call: 1d9b. object).  If that sequence of
calls are in *note mock_calls: 461f. then the assert succeeds.

     >>> m = MagicMock()
     >>> m().foo().bar().baz()
     <MagicMock name='mock().foo().bar().baz()' id='...'>
     >>> m.one().two().three()
     <MagicMock name='mock.one().two().three()' id='...'>
     >>> calls = call.one().two().three().call_list()
     >>> m.assert_has_calls(calls)

Even though the chained call ‘m.one().two().three()’ aren’t the only
calls that have been made to the mock, the assert still succeeds.

Sometimes a mock may have several calls made to it, and you are only
interested in asserting about 'some' of those calls.  You may not even
care about the order.  In this case you can pass ‘any_order=True’ to
‘assert_has_calls’:

     >>> m = MagicMock()
     >>> m(1), m.two(2, 3), m.seven(7), m.fifty('50')
     (...)
     >>> calls = [call.fifty('50'), call(1), call.seven(7)]
     >>> m.assert_has_calls(calls, any_order=True)


File: python.info,  Node: More complex argument matching,  Prev: Tracking order of calls and less verbose call assertions,  Up: Further Examples

5.26.7.28 More complex argument matching
........................................

Using the same basic concept as *note ANY: 1d99. we can implement
matchers to do more complex assertions on objects used as arguments to
mocks.

Suppose we expect some object to be passed to a mock that by default
compares equal based on object identity (which is the Python default for
user defined classes).  To use *note assert_called_with(): 1deb. we
would need to pass in the exact same object.  If we are only interested
in some of the attributes of this object then we can create a matcher
that will check these attributes for us.

You can see in this example how a “standard” call to
‘assert_called_with’ isn’t sufficient:

     >>> class Foo:
     ...     def __init__(self, a, b):
     ...         self.a, self.b = a, b
     ...
     >>> mock = Mock(return_value=None)
     >>> mock(Foo(1, 2))
     >>> mock.assert_called_with(Foo(1, 2))
     Traceback (most recent call last):
         ...
     AssertionError: expected call not found.
     Expected: mock(<__main__.Foo object at 0x...>)
     Actual: mock(<__main__.Foo object at 0x...>)

A comparison function for our ‘Foo’ class might look something like
this:

     >>> def compare(self, other):
     ...     if not type(self) == type(other):
     ...         return False
     ...     if self.a != other.a:
     ...         return False
     ...     if self.b != other.b:
     ...         return False
     ...     return True
     ...

And a matcher object that can use comparison functions like this for its
equality operation would look something like this:

     >>> class Matcher:
     ...     def __init__(self, compare, some_obj):
     ...         self.compare = compare
     ...         self.some_obj = some_obj
     ...     def __eq__(self, other):
     ...         return self.compare(self.some_obj, other)
     ...

Putting all this together:

     >>> match_foo = Matcher(compare, Foo(1, 2))
     >>> mock.assert_called_with(match_foo)

The ‘Matcher’ is instantiated with our compare function and the ‘Foo’
object we want to compare against.  In ‘assert_called_with’ the
‘Matcher’ equality method will be called, which compares the object the
mock was called with against the one we created our matcher with.  If
they match then ‘assert_called_with’ passes, and if they don’t an *note
AssertionError: 8b9. is raised:

     >>> match_wrong = Matcher(compare, Foo(3, 4))
     >>> mock.assert_called_with(match_wrong)
     Traceback (most recent call last):
         ...
     AssertionError: Expected: ((<Matcher object at 0x...>,), {})
     Called with: ((<Foo object at 0x...>,), {})

With a bit of tweaking you could have the comparison function raise the
*note AssertionError: 8b9. directly and provide a more useful failure
message.

As of version 1.5, the Python testing library PyHamcrest(1) provides
similar functionality, that may be useful here, in the form of its
equality matcher (hamcrest.library.integration.match_equality(2)).

   ---------- Footnotes ----------

   (1) https://pyhamcrest.readthedocs.io/

   (2) 
https://pyhamcrest.readthedocs.io/en/release-1.8/integration/#module-hamcrest.library.integration.match_equality


File: python.info,  Node: test — Regression tests package for Python,  Next: test support — Utilities for the Python test suite,  Prev: unittest mock — getting started,  Up: Development Tools

5.26.8 ‘test’ — Regression tests package for Python
---------------------------------------------------

     Nota: The *note test: e8. package is meant for internal use by
     Python only.  It is documented for the benefit of the core
     developers of Python.  Any use of this package outside of Python’s
     standard library is discouraged as code mentioned here can change
     or be removed without notice between releases of Python.

__________________________________________________________________

The *note test: e8. package contains all regression tests for Python as
well as the modules *note test.support: ea. and *note test.regrtest: e9.
*note test.support: ea. is used to enhance your tests while *note
test.regrtest: e9. drives the testing suite.

Each module in the *note test: e8. package whose name starts with
‘test_’ is a testing suite for a specific module or feature.  All new
tests should be written using the *note unittest: 10c. or *note doctest:
3e. module.  Some older tests are written using a «traditional» testing
style that compares output printed to ‘sys.stdout’; this style of test
is considered deprecated.

Vedi anche
..........

Module *note unittest: 10c.

     Writing PyUnit regression tests.

Module *note doctest: 3e.

     Tests embedded in documentation strings.

* Menu:

* Writing Unit Tests for the test package::
* Running tests using the command-line interface::


File: python.info,  Node: Writing Unit Tests for the test package,  Next: Running tests using the command-line interface,  Up: test — Regression tests package for Python

5.26.8.1 Writing Unit Tests for the ‘test’ package
..................................................

It is preferred that tests that use the *note unittest: 10c. module
follow a few guidelines.  One is to name the test module by starting it
with ‘test_’ and end it with the name of the module being tested.  The
test methods in the test module should start with ‘test_’ and end with a
description of what the method is testing.  This is needed so that the
methods are recognized by the test driver as test methods.  Also, no
documentation string for the method should be included.  A comment (such
as ‘# Tests function returns only True or False’) should be used to
provide documentation for test methods.  This is done because
documentation strings get printed out if they exist and thus what test
is being run is not stated.

A basic boilerplate is often used:

     import unittest
     from test import support

     class MyTestCase1(unittest.TestCase):

         # Only use setUp() and tearDown() if necessary

         def setUp(self):
             ... code to execute in preparation for tests ...

         def tearDown(self):
             ... code to execute to clean up after tests ...

         def test_feature_one(self):
             # Test feature one.
             ... testing code ...

         def test_feature_two(self):
             # Test feature two.
             ... testing code ...

         ... more test methods ...

     class MyTestCase2(unittest.TestCase):
         ... same structure as MyTestCase1 ...

     ... more test classes ...

     if __name__ == '__main__':
         unittest.main()

This code pattern allows the testing suite to be run by *note
test.regrtest: e9, on its own as a script that supports the *note
unittest: 10c. CLI, or via the ‘python -m unittest’ CLI.

The goal for regression testing is to try to break code.  This leads to
a few guidelines to be followed:

   * The testing suite should exercise all classes, functions, and
     constants.  This includes not just the external API that is to be
     presented to the outside world but also «private» code.

   * Whitebox testing (examining the code being tested when the tests
     are being written) is preferred.  Blackbox testing (testing only
     the published user interface) is not complete enough to make sure
     all boundary and edge cases are tested.

   * Make sure all possible values are tested including invalid ones.
     This makes sure that not only all valid values are acceptable but
     also that improper values are handled correctly.

   * Exhaust as many code paths as possible.  Test where branching
     occurs and thus tailor input to make sure as many different paths
     through the code are taken.

   * Add an explicit test for any bugs discovered for the tested code.
     This will make sure that the error does not crop up again if the
     code is changed in the future.

   * Make sure to clean up after your tests (such as close and remove
     all temporary files).

   * If a test is dependent on a specific condition of the operating
     system then verify the condition already exists before attempting
     the test.

   * Import as few modules as possible and do it as soon as possible.
     This minimizes external dependencies of tests and also minimizes
     possible anomalous behavior from side-effects of importing a
     module.

   * Try to maximize code reuse.  On occasion, tests will vary by
     something as small as what type of input is used.  Minimize code
     duplication by subclassing a basic test class with a class that
     specifies the input:

          class TestFuncAcceptsSequencesMixin:

              func = mySuperWhammyFunction

              def test_func(self):
                  self.func(self.arg)

          class AcceptLists(TestFuncAcceptsSequencesMixin, unittest.TestCase):
              arg = [1, 2, 3]

          class AcceptStrings(TestFuncAcceptsSequencesMixin, unittest.TestCase):
              arg = 'abc'

          class AcceptTuples(TestFuncAcceptsSequencesMixin, unittest.TestCase):
              arg = (1, 2, 3)

     When using this pattern, remember that all classes that inherit
     from *note unittest.TestCase: 2b3. are run as tests.  The
     ‘TestFuncAcceptsSequencesMixin’ class in the example above does not
     have any data and so can’t be run by itself, thus it does not
     inherit from *note unittest.TestCase: 2b3.

Vedi anche
..........

Test Driven Development

     A book by Kent Beck on writing tests before code.


File: python.info,  Node: Running tests using the command-line interface,  Prev: Writing Unit Tests for the test package,  Up: test — Regression tests package for Python

5.26.8.2 Running tests using the command-line interface
.......................................................

The *note test: e8. package can be run as a script to drive Python’s
regression test suite, thanks to the *note -m: 23c. option: ‘python -m
test’.  Under the hood, it uses *note test.regrtest: e9.; the call
‘python -m test.regrtest’ used in previous Python versions still works.
Running the script by itself automatically starts running all regression
tests in the *note test: e8. package.  It does this by finding all
modules in the package whose name starts with ‘test_’, importing them,
and executing the function ‘test_main()’ if present or loading the tests
via unittest.TestLoader.loadTestsFromModule if ‘test_main’ does not
exist.  The names of tests to execute may also be passed to the script.
Specifying a single regression test (‘python -m test test_spam’) will
minimize output and only print whether the test passed or failed.

Running *note test: e8. directly allows what resources are available for
tests to use to be set.  You do this by using the ‘-u’ command-line
option.  Specifying ‘all’ as the value for the ‘-u’ option enables all
possible resources: ‘python -m test -uall’.  If all but one resource is
desired (a more common case), a comma-separated list of resources that
are not desired may be listed after ‘all’.  The command ‘python -m test
-uall,-audio,-largefile’ will run *note test: e8. with all resources
except the ‘audio’ and ‘largefile’ resources.  For a list of all
resources and more command-line options, run ‘python -m test -h’.

Some other ways to execute the regression tests depend on what platform
the tests are being executed on.  On Unix, you can run ‘make test’ at
the top-level directory where Python was built.  On Windows, executing
‘rt.bat’ from your ‘PCbuild’ directory will run all regression tests.

Added in version 3.14: Output is colorized by default and can be *note
controlled using environment variables: 1b7.


File: python.info,  Node: test support — Utilities for the Python test suite,  Next: test support socket_helper — Utilities for socket tests,  Prev: test — Regression tests package for Python,  Up: Development Tools

5.26.9 ‘test.support’ — Utilities for the Python test suite
-----------------------------------------------------------

The *note test.support: ea. module provides support for Python’s
regression test suite.

     Nota: *note test.support: ea. is not a public module.  It is
     documented here to help Python developers write tests.  The API of
     this module is subject to change without backwards compatibility
     concerns between releases.

This module defines the following exceptions:

 -- Eccezione: test.support.TestFailed

     Exception to be raised when a test fails.  This is deprecated in
     favor of *note unittest: 10c.-based tests and *note
     unittest.TestCase: 2b3.’s assertion methods.

 -- Eccezione: test.support.ResourceDenied

     Subclass of *note unittest.SkipTest: 11e6.  Raised when a resource
     (such as a network connection) is not available.  Raised by the
     *note requires(): 4687. function.

The *note test.support: ea. module defines the following constants:

 -- Dati: test.support.verbose

     ‘True’ when verbose output is enabled.  Should be checked when more
     detailed information is desired about a running test.  'verbose' is
     set by *note test.regrtest: e9.

 -- Dati: test.support.is_jython

     ‘True’ if the running interpreter is Jython.

 -- Dati: test.support.is_android

     ‘True’ if ‘sys.platform’ is ‘android’.

 -- Dati: test.support.is_emscripten

     ‘True’ if ‘sys.platform’ is ‘emscripten’.

 -- Dati: test.support.is_wasi

     ‘True’ if ‘sys.platform’ is ‘wasi’.

 -- Dati: test.support.is_apple_mobile

     ‘True’ if ‘sys.platform’ is ‘ios’, ‘tvos’, or ‘watchos’.

 -- Dati: test.support.is_apple

     ‘True’ if ‘sys.platform’ is ‘darwin’ or ‘is_apple_mobile’ is
     ‘True’.

 -- Dati: test.support.unix_shell

     Path for shell if not on Windows; otherwise ‘None’.

 -- Dati: test.support.LOOPBACK_TIMEOUT

     Timeout in seconds for tests using a network server listening on
     the network local loopback interface like ‘127.0.0.1’.

     The timeout is long enough to prevent test failure: it takes into
     account that the client and the server can run in different threads
     or even different processes.

     The timeout should be long enough for *note connect(): fa5, *note
     recv(): fa6. and *note send(): fa9. methods of *note socket.socket:
     fa3.

     Its default value is 5 seconds.

     See also *note INTERNET_TIMEOUT: 1d85.

 -- Dati: test.support.INTERNET_TIMEOUT

     Timeout in seconds for network requests going to the internet.

     The timeout is short enough to prevent a test to wait for too long
     if the internet request is blocked for whatever reason.

     Usually, a timeout using *note INTERNET_TIMEOUT: 1d85. should not
     mark a test as failed, but skip the test instead: see *note
     transient_internet(): 4690.

     Its default value is 1 minute.

     See also *note LOOPBACK_TIMEOUT: 1d84.

 -- Dati: test.support.SHORT_TIMEOUT

     Timeout in seconds to mark a test as failed if the test takes «too
     long».

     The timeout value depends on the regrtest ‘--timeout’ command line
     option.

     If a test using *note SHORT_TIMEOUT: 1c4b. starts to fail randomly
     on slow buildbots, use *note LONG_TIMEOUT: 1d86. instead.

     Its default value is 30 seconds.

 -- Dati: test.support.LONG_TIMEOUT

     Timeout in seconds to detect when a test hangs.

     It is long enough to reduce the risk of test failure on the slowest
     Python buildbots.  It should not be used to mark a test as failed
     if the test takes «too long».  The timeout value depends on the
     regrtest ‘--timeout’ command line option.

     Its default value is 5 minutes.

     See also *note LOOPBACK_TIMEOUT: 1d84, *note INTERNET_TIMEOUT:
     1d85. and *note SHORT_TIMEOUT: 1c4b.

 -- Dati: test.support.PGO

     Set when tests can be skipped when they are not useful for PGO.

 -- Dati: test.support.PIPE_MAX_SIZE

     A constant that is likely larger than the underlying OS pipe buffer
     size, to make writes blocking.

 -- Dati: test.support.Py_DEBUG

     ‘True’ if Python was built with the *note Py_DEBUG: 181c. macro
     defined, that is, if Python was *note built in debug mode: 50a.

     Added in version 3.12.

 -- Dati: test.support.SOCK_MAX_SIZE

     A constant that is likely larger than the underlying OS socket
     buffer size, to make writes blocking.

 -- Dati: test.support.TEST_SUPPORT_DIR

     Set to the top level directory that contains *note test.support:
     ea.

 -- Dati: test.support.TEST_HOME_DIR

     Set to the top level directory for the test package.

 -- Dati: test.support.TEST_DATA_DIR

     Set to the ‘data’ directory within the test package.

 -- Dati: test.support.MAX_Py_ssize_t

     Set to *note sys.maxsize: 13cd. for big memory tests.

 -- Dati: test.support.max_memuse

     Set by *note set_memlimit(): 469a. as the memory limit for big
     memory tests.  Limited by *note MAX_Py_ssize_t: 4698.

 -- Dati: test.support.real_max_memuse

     Set by *note set_memlimit(): 469a. as the memory limit for big
     memory tests.  Not limited by *note MAX_Py_ssize_t: 4698.

 -- Dati: test.support.MISSING_C_DOCSTRINGS

     Set to ‘True’ if Python is built without docstrings (the
     ‘WITH_DOC_STRINGS’ macro is not defined).  See the *note configure
     -without-doc-strings: 218b. option.

     See also the *note HAVE_DOCSTRINGS: 469d. variable.

 -- Dati: test.support.HAVE_DOCSTRINGS

     Set to ‘True’ if function docstrings are available.  See the *note
     python -OO: 18c. option, which strips docstrings of functions
     implemented in Python.

     See also the *note MISSING_C_DOCSTRINGS: 469c. variable.

 -- Dati: test.support.TEST_HTTP_URL

     Define the URL of a dedicated HTTP server for the network tests.

 -- Dati: test.support.ALWAYS_EQ

     Object that is equal to anything.  Used to test mixed type
     comparison.

 -- Dati: test.support.NEVER_EQ

     Object that is not equal to anything (even to *note ALWAYS_EQ:
     469f.).  Used to test mixed type comparison.

 -- Dati: test.support.LARGEST

     Object that is greater than anything (except itself).  Used to test
     mixed type comparison.

 -- Dati: test.support.SMALLEST

     Object that is less than anything (except itself).  Used to test
     mixed type comparison.

The *note test.support: ea. module defines the following functions:

 -- Funzione: test.support.busy_retry (timeout, err_msg=None, /, *,
          error=True)

     Run the loop body until ‘break’ stops the loop.

     After 'timeout' seconds, raise an *note AssertionError: 8b9. if
     'error' is true, or just stop the loop if 'error' is false.

     Example:

          for _ in support.busy_retry(support.SHORT_TIMEOUT):
              if check():
                  break

     Example of error=False usage:

          for _ in support.busy_retry(support.SHORT_TIMEOUT, error=False):
              if check():
                  break
          else:
              raise RuntimeError('my custom error')

 -- Funzione: test.support.sleeping_retry (timeout, err_msg=None, /, *,
          init_delay=0.010, max_delay=1.0, error=True)

     Wait strategy that applies exponential backoff.

     Run the loop body until ‘break’ stops the loop.  Sleep at each loop
     iteration, but not at the first iteration.  The sleep delay is
     doubled at each iteration (up to 'max_delay' seconds).

     See *note busy_retry(): 46a3. documentation for the parameters
     usage.

     Example raising an exception after SHORT_TIMEOUT seconds:

          for _ in support.sleeping_retry(support.SHORT_TIMEOUT):
              if check():
                  break

     Example of error=False usage:

          for _ in support.sleeping_retry(support.SHORT_TIMEOUT, error=False):
              if check():
                  break
          else:
              raise RuntimeError('my custom error')

 -- Funzione: test.support.is_resource_enabled (resource)

     Return ‘True’ if 'resource' is enabled and available.  The list of
     available resources is only set when *note test.regrtest: e9. is
     executing the tests.

 -- Funzione: test.support.get_resource_value (resource)

     Return the value specified for 'resource' (as ‘-u RESOURCE=VALUE’).
     Return ‘None’ if 'resource' is disabled or no value is specified.

 -- Funzione: test.support.python_is_optimized ()

     Return ‘True’ if Python was not built with ‘-O0’ or ‘-Og’.

 -- Funzione: test.support.with_pymalloc ()

     Return ‘_testcapi.WITH_PYMALLOC’.

 -- Funzione: test.support.requires (resource, msg=None)

     Raise *note ResourceDenied: 4686. if 'resource' is not available.
     'msg' is the argument to *note ResourceDenied: 4686. if it is
     raised.  Always returns ‘True’ if called by a function whose
     ‘__name__’ is ‘'__main__'’.  Used when tests are executed by *note
     test.regrtest: e9.

 -- Funzione: test.support.sortdict (dict)

     Return a repr of 'dict' with keys sorted.

 -- Funzione: test.support.findfile (filename, subdir=None)

     Return the path to the file named 'filename'.  If no match is found
     'filename' is returned.  This does not equal a failure since it
     could be the path to the file.

     Setting 'subdir' indicates a relative path to use to find the file
     rather than looking directly in the path directories.

 -- Funzione: test.support.get_pagesize ()

     Get size of a page in bytes.

     Added in version 3.12.

 -- Funzione: test.support.setswitchinterval (interval)

     Set the *note sys.setswitchinterval(): b46. to the given
     'interval'.  Defines a minimum interval for Android systems to
     prevent the system from hanging.

 -- Funzione: test.support.check_impl_detail (**guards)

     Use this check to guard CPython’s implementation-specific tests or
     to run them only on the implementations guarded by the arguments.
     This function returns ‘True’ or ‘False’ depending on the host
     platform.  Example usage:

          check_impl_detail()               # Only on CPython (default).
          check_impl_detail(jython=True)    # Only on Jython.
          check_impl_detail(cpython=False)  # Everywhere except CPython.

 -- Funzione: test.support.set_memlimit (limit)

     Set the values for *note max_memuse: 4699. and *note
     real_max_memuse: 469b. for big memory tests.

 -- Funzione: test.support.record_original_stdout (stdout)

     Store the value from 'stdout'.  It is meant to hold the stdout at
     the time the regrtest began.

 -- Funzione: test.support.get_original_stdout ()

     Return the original stdout set by *note record_original_stdout():
     46ae. or ‘sys.stdout’ if it’s not set.

 -- Funzione: test.support.args_from_interpreter_flags ()

     Return a list of command line arguments reproducing the current
     settings in ‘sys.flags’ and ‘sys.warnoptions’.

 -- Funzione: test.support.optim_args_from_interpreter_flags ()

     Return a list of command line arguments reproducing the current
     optimization settings in ‘sys.flags’.

 -- Funzione: test.support.captured_stdin ()
 -- Funzione: test.support.captured_stdout ()
 -- Funzione: test.support.captured_stderr ()

     A context managers that temporarily replaces the named stream with
     *note io.StringIO: 112b. object.

     Example use with output streams:

          with captured_stdout() as stdout, captured_stderr() as stderr:
              print("hello")
              print("error", file=sys.stderr)
          assert stdout.getvalue() == "hello\n"
          assert stderr.getvalue() == "error\n"

     Example use with input stream:

          with captured_stdin() as stdin:
              stdin.write('hello\n')
              stdin.seek(0)
              # call test code that consumes from sys.stdin
              captured = input()
          self.assertEqual(captured, "hello")

 -- Funzione: test.support.disable_faulthandler ()

     A context manager that temporary disables *note faulthandler: 5c.

 -- Funzione: test.support.gc_collect ()

     Force as many objects as possible to be collected.  This is needed
     because timely deallocation is not guaranteed by the garbage
     collector.  This means that ‘__del__’ methods may be called later
     than expected and weakrefs may remain alive for longer than
     expected.

 -- Funzione: test.support.disable_gc ()

     A context manager that disables the garbage collector on entry.  On
     exit, the garbage collector is restored to its prior state.

 -- Funzione: test.support.swap_attr (obj, attr, new_val)

     Context manager to swap out an attribute with a new object.

     Usage:

          with swap_attr(obj, "attr", 5):
              ...

     This will set ‘obj.attr’ to 5 for the duration of the ‘with’ block,
     restoring the old value at the end of the block.  If ‘attr’ doesn’t
     exist on ‘obj’, it will be created and then deleted at the end of
     the block.

     The old value (or ‘None’ if it doesn’t exist) will be assigned to
     the target of the «as» clause, if there is one.

 -- Funzione: test.support.swap_item (obj, attr, new_val)

     Context manager to swap out an item with a new object.

     Usage:

          with swap_item(obj, "item", 5):
              ...

     This will set ‘obj["item"]’ to 5 for the duration of the ‘with’
     block, restoring the old value at the end of the block.  If ‘item’
     doesn’t exist on ‘obj’, it will be created and then deleted at the
     end of the block.

     The old value (or ‘None’ if it doesn’t exist) will be assigned to
     the target of the «as» clause, if there is one.

 -- Funzione: test.support.flush_std_streams ()

     Call the ‘flush()’ method on *note sys.stdout: ccf. and then on
     *note sys.stderr: b35.  It can be used to make sure that the logs
     order is consistent before writing into stderr.

     Added in version 3.11.

 -- Funzione: test.support.print_warning (msg)

     Print a warning into *note sys.__stderr__: 46bb.  Format the
     message as: ‘f"Warning -- {msg}"’.  If 'msg' is made of multiple
     lines, add ‘"Warning -- "’ prefix to each line.

     Added in version 3.9.

 -- Funzione: test.support.wait_process (pid, *, exitcode, timeout=None)

     Wait until process 'pid' completes and check that the process exit
     code is 'exitcode'.

     Raise an *note AssertionError: 8b9. if the process exit code is not
     equal to 'exitcode'.

     If the process runs longer than 'timeout' seconds (*note
     SHORT_TIMEOUT: 1c4b. by default), kill the process and raise an
     *note AssertionError: 8b9.  The timeout feature is not available on
     Windows.

     Added in version 3.9.

 -- Funzione: test.support.calcobjsize (fmt)

     Return the size of the *note PyObject: 5df. whose structure members
     are defined by 'fmt'.  The returned value includes the size of the
     Python object header and alignment.

 -- Funzione: test.support.calcvobjsize (fmt)

     Return the size of the *note PyVarObject: 46be. whose structure
     members are defined by 'fmt'.  The returned value includes the size
     of the Python object header and alignment.

 -- Funzione: test.support.checksizeof (test, o, size)

     For testcase 'test', assert that the ‘sys.getsizeof’ for 'o' plus
     the GC header size equals 'size'.

 -- Funzione: @test.support.anticipate_failure (condition)

     A decorator to conditionally mark tests with *note
     unittest.expectedFailure(): 45d1.  Any use of this decorator should
     have an associated comment identifying the relevant tracker issue.

 -- Funzione: test.support.system_must_validate_cert (f)

     A decorator that skips the decorated test on TLS certification
     validation failures.

 -- Funzione: @test.support.run_with_locale (catstr, *locales)

     A decorator for running a function in a different locale, correctly
     resetting it after it has finished.  'catstr' is the locale
     category as a string (for example ‘"LC_ALL"’).  The 'locales'
     passed will be tried sequentially, and the first valid locale will
     be used.

 -- Funzione: @test.support.run_with_tz (tz)

     A decorator for running a function in a specific timezone,
     correctly resetting it after it has finished.

 -- Funzione: @test.support.requires_freebsd_version (*min_version)

     Decorator for the minimum version when running test on FreeBSD. If
     the FreeBSD version is less than the minimum, the test is skipped.

 -- Funzione: @test.support.requires_linux_version (*min_version)

     Decorator for the minimum version when running test on Linux.  If
     the Linux version is less than the minimum, the test is skipped.

 -- Funzione: @test.support.requires_mac_version (*min_version)

     Decorator for the minimum version when running test on macOS. If
     the macOS version is less than the minimum, the test is skipped.

 -- Funzione: @test.support.requires_gil_enabled

     Decorator for skipping tests on the free-threaded build.  If the
     *note GIL: 164. is disabled, the test is skipped.

 -- Funzione: @test.support.requires_IEEE_754

     Decorator for skipping tests on non-IEEE 754 platforms.

 -- Funzione: @test.support.requires_zlib

     Decorator for skipping tests if *note zlib: 139. doesn’t exist.

 -- Funzione: @test.support.requires_gzip

     Decorator for skipping tests if *note gzip: 6b. doesn’t exist.

 -- Funzione: @test.support.requires_bz2

     Decorator for skipping tests if *note bz2: 14. doesn’t exist.

 -- Funzione: @test.support.requires_lzma

     Decorator for skipping tests if *note lzma: 8e. doesn’t exist.

 -- Funzione: @test.support.requires_resource (resource)

     Decorator for skipping tests if 'resource' is not available.

 -- Funzione: @test.support.requires_docstrings

     Decorator for only running the test if *note HAVE_DOCSTRINGS: 469d.

 -- Funzione: @test.support.requires_limited_api

     Decorator for only running the test if *note Limited C API: 637. is
     available.

 -- Funzione: @test.support.cpython_only

     Decorator for tests only applicable to CPython.

 -- Funzione: @test.support.impl_detail (msg=None, **guards)

     Decorator for invoking *note check_impl_detail(): 46ad. on
     'guards'.  If that returns ‘False’, then uses 'msg' as the reason
     for skipping the test.

 -- Funzione: @test.support.thread_unsafe (reason=None)

     Decorator for marking tests as thread-unsafe.  This test always
     runs in one thread even when invoked with ‘--parallel-threads’.

 -- Funzione: @test.support.no_tracing

     Decorator to temporarily turn off tracing for the duration of the
     test.

 -- Funzione: @test.support.refcount_test

     Decorator for tests which involve reference counting.  The
     decorator does not run the test if it is not run by CPython.  Any
     trace function is unset for the duration of the test to prevent
     unexpected refcounts caused by the trace function.

 -- Funzione: @test.support.bigmemtest (size, memuse, dry_run=True)

     Decorator for bigmem tests.

     'size' is a requested size for the test (in arbitrary,
     test-interpreted units.)  'memuse' is the number of bytes per unit
     for the test, or a good estimate of it.  For example, a test that
     needs two byte buffers, of 4 GiB each, could be decorated with
     ‘@bigmemtest(size=_4G, memuse=2)’.

     The 'size' argument is normally passed to the decorated test method
     as an extra argument.  If 'dry_run' is ‘True’, the value passed to
     the test method may be less than the requested value.  If 'dry_run'
     is ‘False’, it means the test doesn’t support dummy runs when ‘-M’
     is not specified.

 -- Funzione: @test.support.bigaddrspacetest

     Decorator for tests that fill the address space.

 -- Funzione: test.support.linked_to_musl ()

     Return ‘False’ if there is no evidence the interpreter was compiled
     with ‘musl’, otherwise return a version triple, either ‘(0, 0, 0)’
     if the version is unknown, or the actual version if it is known.
     Intended for use in ‘skip’ decorators.  ‘emscripten’ and ‘wasi’ are
     assumed to be compiled with ‘musl’; otherwise ‘platform.libc_ver’
     is checked.

 -- Funzione: test.support.check_syntax_error (testcase, statement,
          errtext='', *, lineno=None, offset=None)

     Test for syntax errors in 'statement' by attempting to compile
     'statement'.  'testcase' is the *note unittest: 10c. instance for
     the test.  'errtext' is the regular expression which should match
     the string representation of the raised *note SyntaxError: 18e.  If
     'lineno' is not ‘None’, compares to the line of the exception.  If
     'offset' is not ‘None’, compares to the offset of the exception.

 -- Funzione: test.support.open_urlresource (url, *args, **kw)

     Open 'url'.  If open fails, raises *note TestFailed: 4685.

 -- Funzione: test.support.reap_children ()

     Use this at the end of ‘test_main’ whenever sub-processes are
     started.  This will help ensure that no extra children (zombies)
     stick around to hog resources and create problems when looking for
     refleaks.

 -- Funzione: test.support.get_attribute (obj, name)

     Get an attribute, raising *note unittest.SkipTest: 11e6. if *note
     AttributeError: 5f0. is raised.

 -- Funzione: test.support.catch_unraisable_exception ()

     Context manager catching unraisable exception using *note
     sys.unraisablehook(): 508.

     Storing the exception value (‘cm.unraisable.exc_value’) creates a
     reference cycle.  The reference cycle is broken explicitly when the
     context manager exits.

     Storing the object (‘cm.unraisable.object’) can resurrect it if it
     is set to an object which is being finalized.  Exiting the context
     manager clears the stored object.

     Usage:

          with support.catch_unraisable_exception() as cm:
              # code creating an "unraisable exception"
              ...

              # check the unraisable exception: use cm.unraisable
              ...

          # cm.unraisable attribute no longer exists at this point
          # (to break a reference cycle)

     Added in version 3.8.

 -- Funzione: test.support.load_package_tests (pkg_dir, loader,
          standard_tests, pattern)

     Generic implementation of the *note unittest: 10c. ‘load_tests’
     protocol for use in test packages.  'pkg_dir' is the root directory
     of the package; 'loader', 'standard_tests', and 'pattern' are the
     arguments expected by ‘load_tests’.  In simple cases, the test
     package’s ‘__init__.py’ can be the following:

          import os
          from test.support import load_package_tests

          def load_tests(*args):
              return load_package_tests(os.path.dirname(__file__), *args)

 -- Funzione: test.support.detect_api_mismatch (ref_api, other_api, *,
          ignore=())

     Returns the set of attributes, functions or methods of 'ref_api'
     not found on 'other_api', except for a defined list of items to be
     ignored in this check specified in 'ignore'.

     By default this skips private attributes beginning with “_” but
     includes all magic methods, i.e.  those starting and ending in
     “__”.

     Added in version 3.5.

 -- Funzione: test.support.patch (test_instance, object_to_patch,
          attr_name, new_value)

     Override 'object_to_patch.attr_name' with 'new_value'.  Also add
     cleanup procedure to 'test_instance' to restore 'object_to_patch'
     for 'attr_name'.  The 'attr_name' should be a valid attribute for
     'object_to_patch'.

 -- Funzione: test.support.run_in_subinterp (code)

     Run 'code' in subinterpreter.  Raise *note unittest.SkipTest: 11e6.
     if *note tracemalloc: 105. is enabled.

 -- Funzione: test.support.check_free_after_iterating (test, iter, cls,
          args=())

     Assert instances of 'cls' are deallocated after iterating.

 -- Funzione: test.support.missing_compiler_executable (cmd_names=[])

     Check for the existence of the compiler executables whose names are
     listed in 'cmd_names' or all the compiler executables when
     'cmd_names' is empty and return the first missing executable or
     ‘None’ when none is found missing.

 -- Funzione: test.support.check__all__ (test_case, module,
          name_of_module=None, extra=(), not_exported=())

     Assert that the ‘__all__’ variable of 'module' contains all public
     names.

     The module’s public names (its API) are detected automatically
     based on whether they match the public name convention and were
     defined in 'module'.

     The 'name_of_module' argument can specify (as a string or tuple
     thereof) what module(s) an API could be defined in order to be
     detected as a public API. One case for this is when 'module'
     imports part of its public API from other modules, possibly a C
     backend (like ‘csv’ and its ‘_csv’).

     The 'extra' argument can be a set of names that wouldn’t otherwise
     be automatically detected as «public», like objects without a
     proper *note __module__: 26ba. attribute.  If provided, it will be
     added to the automatically detected ones.

     The 'not_exported' argument can be a set of names that must not be
     treated as part of the public API even though their names indicate
     otherwise.

     Example use:

          import bar
          import foo
          import unittest
          from test import support

          class MiscTestCase(unittest.TestCase):
              def test__all__(self):
                  support.check__all__(self, foo)

          class OtherTestCase(unittest.TestCase):
              def test__all__(self):
                  extra = {'BAR_CONST', 'FOO_CONST'}
                  not_exported = {'baz'}  # Undocumented name.
                  # bar imports part of its API from _bar.
                  support.check__all__(self, bar, ('bar', '_bar'),
                                       extra=extra, not_exported=not_exported)

     Added in version 3.6.

 -- Funzione: test.support.skip_if_broken_multiprocessing_synchronize ()

     Skip tests if the ‘multiprocessing.synchronize’ module is missing,
     if there is no available semaphore implementation, or if creating a
     lock raises an *note OSError: 2c0.

     Added in version 3.10.

 -- Funzione: test.support.check_disallow_instantiation (test_case, tp,
          *args, **kwds)

     Assert that type 'tp' cannot be instantiated using 'args' and
     'kwds'.

     Added in version 3.10.

 -- Funzione: test.support.adjust_int_max_str_digits (max_digits)

     This function returns a context manager that will change the global
     *note sys.set_int_max_str_digits(): 18d9. setting for the duration
     of the context to allow execution of test code that needs a
     different limit on the number of digits when converting between an
     integer and string.

     Added in version 3.11.

The *note test.support: ea. module defines the following classes:

 -- Classe: test.support.SuppressCrashReport

     A context manager used to try to prevent crash dialog popups on
     tests that are expected to crash a subprocess.

     On Windows, it disables Windows Error Reporting dialogs using
     SetErrorMode(1).

     On UNIX, *note resource.setrlimit(): 17ae. is used to set *note
     resource.RLIMIT_CORE: 46e5.’s soft limit to 0 to prevent coredump
     file creation.

     On both platforms, the old value is restored by *note __exit__():
     1508.

 -- Classe: test.support.SaveSignals

     Class to save and restore signal handlers registered by the Python
     signal handler.

      -- Metodo: save (self)

          Save the signal handlers to a dictionary mapping signal
          numbers to the current signal handler.

      -- Metodo: restore (self)

          Set the signal numbers from the *note save(): 46e7. dictionary
          to the saved handler.

 -- Classe: test.support.Matcher

      -- Metodo: matches (self, d, **kwargs)

          Try to match a single dict with the supplied arguments.

      -- Metodo: match_value (self, k, dv, v)

          Try to match a single stored value ('dv') with a supplied
          value ('v').

   ---------- Footnotes ----------

   (1) 
https://msdn.microsoft.com/en-us/library/windows/desktop/ms680621.aspx


File: python.info,  Node: test support socket_helper — Utilities for socket tests,  Next: test support script_helper — Utilities for the Python execution tests,  Prev: test support — Utilities for the Python test suite,  Up: Development Tools

5.26.10 ‘test.support.socket_helper’ — Utilities for socket tests
-----------------------------------------------------------------

The *note test.support.socket_helper: ef. module provides support for
socket tests.

Added in version 3.9.

 -- Dati: test.support.socket_helper.IPV6_ENABLED

     Set to ‘True’ if IPv6 is enabled on this host, ‘False’ otherwise.

 -- Funzione: test.support.socket_helper.find_unused_port
          (family=socket.AF_INET, socktype=socket.SOCK_STREAM)

     Returns an unused port that should be suitable for binding.  This
     is achieved by creating a temporary socket with the same family and
     type as the ‘sock’ parameter (default is *note AF_INET: 1b95, *note
     SOCK_STREAM: 14fb.), and binding it to the specified host address
     (defaults to ‘0.0.0.0’) with the port set to 0, eliciting an unused
     ephemeral port from the OS. The temporary socket is then closed and
     deleted, and the ephemeral port is returned.

     Either this method or *note bind_port(): 46ef. should be used for
     any tests where a server socket needs to be bound to a particular
     port for the duration of the test.  Which one to use depends on
     whether the calling code is creating a Python socket, or if an
     unused port needs to be provided in a constructor or passed to an
     external program (i.e.  the ‘-accept’ argument to openssl’s
     s_server mode).  Always prefer *note bind_port(): 46ef. over *note
     find_unused_port(): 46ee. where possible.  Using a hard coded port
     is discouraged since it can make multiple instances of the test
     impossible to run simultaneously, which is a problem for buildbots.

 -- Funzione: test.support.socket_helper.bind_port (sock, host=HOST)

     Bind the socket to a free port and return the port number.  Relies
     on ephemeral ports in order to ensure we are using an unbound port.
     This is important as many tests may be running simultaneously,
     especially in a buildbot environment.  This method raises an
     exception if the ‘sock.family’ is *note AF_INET: 1b95. and
     ‘sock.type’ is *note SOCK_STREAM: 14fb, and the socket has
     ‘SO_REUSEADDR’ or ‘SO_REUSEPORT’ set on it.  Tests should never set
     these socket options for TCP/IP sockets.  The only case for setting
     these options is testing multicasting via multiple UDP sockets.

     Additionally, if the ‘SO_EXCLUSIVEADDRUSE’ socket option is
     available (i.e.  on Windows), it will be set on the socket.  This
     will prevent anyone else from binding to our host/port for the
     duration of the test.

 -- Funzione: test.support.socket_helper.bind_unix_socket (sock, addr)

     Bind a Unix socket, raising *note unittest.SkipTest: 11e6. if *note
     PermissionError: f40. is raised.

 -- Funzione: @test.support.socket_helper.skip_unless_bind_unix_socket

     A decorator for running tests that require a functional ‘bind()’
     for Unix sockets.

 -- Funzione: test.support.socket_helper.transient_internet
          (resource_name, *, timeout=30.0, errnos=())

     A context manager that raises *note ResourceDenied: 4686. when
     various issues with the internet connection manifest themselves as
     exceptions.


File: python.info,  Node: test support script_helper — Utilities for the Python execution tests,  Next: test support bytecode_helper — Support tools for testing correct bytecode generation,  Prev: test support socket_helper — Utilities for socket tests,  Up: Development Tools

5.26.11 ‘test.support.script_helper’ — Utilities for the Python execution tests
-------------------------------------------------------------------------------

The *note test.support.script_helper: ee. module provides support for
Python’s script execution tests.

 -- Funzione:
          test.support.script_helper.interpreter_requires_environment ()

     Return ‘True’ if ‘sys.executable interpreter’ requires environment
     variables in order to be able to run at all.

     This is designed to be used with ‘@unittest.skipIf()’ to annotate
     tests that need to use an ‘assert_python*()’ function to launch an
     isolated mode (‘-I’) or no environment mode (‘-E’) sub-interpreter
     process.

     A normal build & test does not run into this situation but it can
     happen when trying to run the standard library test suite from an
     interpreter that doesn’t have an obvious home with Python’s current
     home finding logic.

     Setting *note PYTHONHOME: 3f0. is one way to get most of the
     testsuite to run in that situation.  *note PYTHONPATH: 121f. or
     ‘PYTHONUSERSITE’ are other common environment variables that might
     impact whether or not the interpreter can start.

 -- Funzione: test.support.script_helper.run_python_until_end (*args,
          **env_vars)

     Set up the environment based on 'env_vars' for running the
     interpreter in a subprocess.  The values can include ‘__isolated’,
     ‘__cleanenv’, ‘__cwd’, and ‘TERM’.

     Cambiato nella versione 3.9: The function no longer strips
     whitespaces from 'stderr'.

 -- Funzione: test.support.script_helper.assert_python_ok (*args,
          **env_vars)

     Assert that running the interpreter with 'args' and optional
     environment variables 'env_vars' succeeds (‘rc == 0’) and return a
     ‘(return code, stdout, stderr)’ tuple.

     If the '__cleanenv' keyword-only parameter is set, 'env_vars' is
     used as a fresh environment.

     Python is started in isolated mode (command line option ‘-I’),
     except if the '__isolated' keyword-only parameter is set to
     ‘False’.

     Cambiato nella versione 3.9: The function no longer strips
     whitespaces from 'stderr'.

 -- Funzione: test.support.script_helper.assert_python_failure (*args,
          **env_vars)

     Assert that running the interpreter with 'args' and optional
     environment variables 'env_vars' fails (‘rc != 0’) and return a
     ‘(return code, stdout, stderr)’ tuple.

     See *note assert_python_ok(): 46f5. for more options.

     Cambiato nella versione 3.9: The function no longer strips
     whitespaces from 'stderr'.

 -- Funzione: test.support.script_helper.spawn_python (*args,
          stdout=subprocess.PIPE, stderr=subprocess.STDOUT, **kw)

     Run a Python subprocess with the given arguments.

     'kw' is extra keyword args to pass to *note subprocess.Popen():
     4b8.  Returns a *note subprocess.Popen: 4b8. object.

 -- Funzione: test.support.script_helper.kill_python (p)

     Run the given *note subprocess.Popen: 4b8. process until completion
     and return stdout.

 -- Funzione: test.support.script_helper.make_script (script_dir,
          script_basename, source, omit_suffix=False)

     Create script containing 'source' in path 'script_dir' and
     'script_basename'.  If 'omit_suffix' is ‘False’, append ‘.py’ to
     the name.  Return the full script path.

 -- Funzione: test.support.script_helper.make_zip_script (zip_dir,
          zip_basename, script_name, name_in_zip=None)

     Create zip file at 'zip_dir' and 'zip_basename' with extension
     ‘zip’ which contains the files in 'script_name'.  'name_in_zip' is
     the archive name.  Return a tuple containing ‘(full path, full path
     of archive name)’.

 -- Funzione: test.support.script_helper.make_pkg (pkg_dir,
          init_source='')

     Create a directory named 'pkg_dir' containing an ‘__init__’ file
     with 'init_source' as its contents.

 -- Funzione: test.support.script_helper.make_zip_pkg (zip_dir,
          zip_basename, pkg_name, script_basename, source, depth=1,
          compiled=False)

     Create a zip package directory with a path of 'zip_dir' and
     'zip_basename' containing an empty ‘__init__’ file and a file
     'script_basename' containing the 'source'.  If 'compiled' is
     ‘True’, both source files will be compiled and added to the zip
     package.  Return a tuple of the full zip path and the archive name
     for the zip file.


File: python.info,  Node: test support bytecode_helper — Support tools for testing correct bytecode generation,  Next: test support threading_helper — Utilities for threading tests,  Prev: test support script_helper — Utilities for the Python execution tests,  Up: Development Tools

5.26.12 ‘test.support.bytecode_helper’ — Support tools for testing correct bytecode generation
----------------------------------------------------------------------------------------------

The *note test.support.bytecode_helper: eb. module provides support for
testing and inspecting bytecode generation.

Added in version 3.9.

The module defines the following class:

 -- Classe: test.support.bytecode_helper.BytecodeTestCase
          (unittest.TestCase)

     This class has custom assertion methods for inspecting bytecode.

 -- Metodo: BytecodeTestCase.get_disassembly_as_string (co)

     Return the disassembly of 'co' as string.

 -- Metodo: BytecodeTestCase.assertInBytecode (x, opname,
          argval=_UNSPECIFIED)

     Return instr if 'opname' is found, otherwise throws *note
     AssertionError: 8b9.

 -- Metodo: BytecodeTestCase.assertNotInBytecode (x, opname,
          argval=_UNSPECIFIED)

     Throws *note AssertionError: 8b9. if 'opname' is found.


File: python.info,  Node: test support threading_helper — Utilities for threading tests,  Next: test support os_helper — Utilities for os tests,  Prev: test support bytecode_helper — Support tools for testing correct bytecode generation,  Up: Development Tools

5.26.13 ‘test.support.threading_helper’ — Utilities for threading tests
-----------------------------------------------------------------------

The *note test.support.threading_helper: f0. module provides support for
threading tests.

Added in version 3.10.

 -- Funzione: test.support.threading_helper.join_thread (thread,
          timeout=None)

     Join a 'thread' within 'timeout'.  Raise an *note AssertionError:
     8b9. if thread is still alive after 'timeout' seconds.

 -- Funzione: @test.support.threading_helper.reap_threads

     Decorator to ensure the threads are cleaned up even if the test
     fails.

 -- Funzione: test.support.threading_helper.start_threads (threads,
          unlock=None)

     Context manager to start 'threads', which is a sequence of threads.
     'unlock' is a function called after the threads are started, even
     if an exception was raised; an example would be *note
     threading.Event.set(): 361c.  ‘start_threads’ will attempt to join
     the started threads upon exit.

 -- Funzione: test.support.threading_helper.threading_cleanup
          (*original_values)

     Cleanup up threads not specified in 'original_values'.  Designed to
     emit a warning if a test leaves running threads in the background.

 -- Funzione: test.support.threading_helper.threading_setup ()

     Return current thread count and copy of dangling threads.

 -- Funzione: test.support.threading_helper.wait_threads_exit
          (timeout=None)

     Context manager to wait until all threads created in the ‘with’
     statement exit.

 -- Funzione: test.support.threading_helper.catch_threading_exception ()

     Context manager catching *note threading.Thread: 176. exception
     using *note threading.excepthook(): a4d.

     Attributes set when an exception is caught:

        * ‘exc_type’

        * ‘exc_value’

        * ‘exc_traceback’

        * ‘thread’

     See *note threading.excepthook(): a4d. documentation.

     These attributes are deleted at the context manager exit.

     Usage:

          with threading_helper.catch_threading_exception() as cm:
              # code spawning a thread which raises an exception
              ...

              # check the thread exception, use cm attributes:
              # exc_type, exc_value, exc_traceback, thread
              ...

          # exc_type, exc_value, exc_traceback, thread attributes of cm no longer
          # exists at this point
          # (to avoid reference cycles)

     Added in version 3.8.

 -- Funzione: test.support.threading_helper.run_concurrently
          (worker_func, nthreads, args=(), kwargs={})

     Run the worker function concurrently in multiple threads.
     Re-raises an exception if any thread raises one, after all threads
     have finished.


File: python.info,  Node: test support os_helper — Utilities for os tests,  Next: test support import_helper — Utilities for import tests,  Prev: test support threading_helper — Utilities for threading tests,  Up: Development Tools

5.26.14 ‘test.support.os_helper’ — Utilities for os tests
---------------------------------------------------------

The *note test.support.os_helper: ed. module provides support for os
tests.

Added in version 3.10.

 -- Dati: test.support.os_helper.FS_NONASCII

     A non-ASCII character encodable by *note os.fsencode(): e51.

 -- Dati: test.support.os_helper.SAVEDCWD

     Set to *note os.getcwd(): 18f1.

 -- Dati: test.support.os_helper.TESTFN

     Set to a name that is safe to use as the name of a temporary file.
     Any temporary file that is created should be closed and unlinked
     (removed).

 -- Dati: test.support.os_helper.TESTFN_NONASCII

     Set to a filename containing the *note FS_NONASCII: 470c.
     character, if it exists.  This guarantees that if the filename
     exists, it can be encoded and decoded with the default filesystem
     encoding.  This allows tests that require a non-ASCII filename to
     be easily skipped on platforms where they can’t work.

 -- Dati: test.support.os_helper.TESTFN_UNENCODABLE

     Set to a filename (str type) that should not be able to be encoded
     by file system encoding in strict mode.  It may be ‘None’ if it’s
     not possible to generate such a filename.

 -- Dati: test.support.os_helper.TESTFN_UNDECODABLE

     Set to a filename (bytes type) that should not be able to be
     decoded by file system encoding in strict mode.  It may be ‘None’
     if it’s not possible to generate such a filename.

 -- Dati: test.support.os_helper.TESTFN_UNICODE

     Set to a non-ASCII name for a temporary file.

 -- Classe: test.support.os_helper.EnvironmentVarGuard

     Class used to temporarily set or unset environment variables.
     Instances can be used as a context manager and have a complete
     dictionary interface for querying/modifying the underlying
     ‘os.environ’.  After exit from the context manager all changes to
     environment variables done through this instance will be rolled
     back.

     Cambiato nella versione 3.1: Added dictionary interface.

 -- Classe: test.support.os_helper.FakePath (path)

     Simple *note path-like object: 5a1.  It implements the *note
     __fspath__(): e4e. method which just returns the 'path' argument.
     If 'path' is an exception, it will be raised in ‘__fspath__()’.

 -- Metodo: EnvironmentVarGuard.set (envvar, value)

     Temporarily set the environment variable ‘envvar’ to the value of
     ‘value’.

 -- Metodo: EnvironmentVarGuard.unset (envvar, *others)

     Temporarily unset one or more environment variables.

     Cambiato nella versione 3.14: More than one environment variable
     can be unset.

 -- Funzione: test.support.os_helper.can_symlink ()

     Return ‘True’ if the OS supports symbolic links, ‘False’ otherwise.

 -- Funzione: test.support.os_helper.can_xattr ()

     Return ‘True’ if the OS supports xattr, ‘False’ otherwise.

 -- Funzione: test.support.os_helper.change_cwd (path, quiet=False)

     A context manager that temporarily changes the current working
     directory to 'path' and yields the directory.

     If 'quiet' is ‘False’, the context manager raises an exception on
     error.  Otherwise, it issues only a warning and keeps the current
     working directory the same.

 -- Funzione: test.support.os_helper.create_empty_file (filename)

     Create an empty file with 'filename'.  If it already exists,
     truncate it.

 -- Funzione: test.support.os_helper.fd_count ()

     Count the number of open file descriptors.

 -- Funzione: test.support.os_helper.fs_is_case_insensitive (directory)

     Return ‘True’ if the file system for 'directory' is
     case-insensitive.

 -- Funzione: test.support.os_helper.make_bad_fd ()

     Create an invalid file descriptor by opening and closing a
     temporary file, and returning its descriptor.

 -- Funzione: test.support.os_helper.rmdir (filename)

     Call *note os.rmdir(): 12fb. on 'filename'.  On Windows platforms,
     this is wrapped with a wait loop that checks for the existence of
     the file, which is needed due to antivirus programs that can hold
     files open and prevent deletion.

 -- Funzione: test.support.os_helper.rmtree (path)

     Call *note shutil.rmtree(): 356. on 'path' or call *note
     os.lstat(): 6c9. and *note os.rmdir(): 12fb. to remove a path and
     its contents.  As with *note rmdir(): 471c, on Windows platforms
     this is wrapped with a wait loop that checks for the existence of
     the files.

 -- Funzione: @test.support.os_helper.skip_unless_symlink

     A decorator for running tests that require support for symbolic
     links.

 -- Funzione: @test.support.os_helper.skip_unless_xattr

     A decorator for running tests that require support for xattr.

 -- Funzione: test.support.os_helper.temp_cwd (name='tempcwd',
          quiet=False)

     A context manager that temporarily creates a new directory and
     changes the current working directory (CWD).

     The context manager creates a temporary directory in the current
     directory with name 'name' before temporarily changing the current
     working directory.  If 'name' is ‘None’, the temporary directory is
     created using *note tempfile.mkdtemp(): 52e.

     If 'quiet' is ‘False’ and it is not possible to create or change
     the CWD, an error is raised.  Otherwise, only a warning is raised
     and the original CWD is used.

 -- Funzione: test.support.os_helper.temp_dir (path=None, quiet=False)

     A context manager that creates a temporary directory at 'path' and
     yields the directory.

     If 'path' is ‘None’, the temporary directory is created using *note
     tempfile.mkdtemp(): 52e.  If 'quiet' is ‘False’, the context
     manager raises an exception on error.  Otherwise, if 'path' is
     specified and cannot be created, only a warning is issued.

 -- Funzione: test.support.os_helper.temp_umask (umask)

     A context manager that temporarily sets the process umask.

 -- Funzione: test.support.os_helper.unlink (filename)

     Call *note os.unlink(): 12fd. on 'filename'.  As with *note
     rmdir(): 471c, on Windows platforms, this is wrapped with a wait
     loop that checks for the existence of the file.


File: python.info,  Node: test support import_helper — Utilities for import tests,  Next: test support warnings_helper — Utilities for warnings tests,  Prev: test support os_helper — Utilities for os tests,  Up: Development Tools

5.26.15 ‘test.support.import_helper’ — Utilities for import tests
-----------------------------------------------------------------

The *note test.support.import_helper: ec. module provides support for
import tests.

Added in version 3.10.

 -- Funzione: test.support.import_helper.forget (module_name)

     Remove the module named 'module_name' from ‘sys.modules’ and delete
     any byte-compiled files of the module.

 -- Funzione: test.support.import_helper.import_fresh_module (name,
          fresh=(), blocked=(), deprecated=False)

     This function imports and returns a fresh copy of the named Python
     module by removing the named module from ‘sys.modules’ before doing
     the import.  Note that unlike ‘reload()’, the original module is
     not affected by this operation.

     'fresh' is an iterable of additional module names that are also
     removed from the ‘sys.modules’ cache before doing the import.

     'blocked' is an iterable of module names that are replaced with
     ‘None’ in the module cache during the import to ensure that
     attempts to import them raise *note ImportError: 65b.

     The named module and any modules named in the 'fresh' and 'blocked'
     parameters are saved before starting the import and then reinserted
     into ‘sys.modules’ when the fresh import is complete.

     Module and package deprecation messages are suppressed during this
     import if 'deprecated' is ‘True’.

     This function will raise *note ImportError: 65b. if the named
     module cannot be imported.

     Example use:

          # Get copies of the warnings module for testing without affecting the
          # version being used by the rest of the test suite. One copy uses the
          # C implementation, the other is forced to use the pure Python fallback
          # implementation
          py_warnings = import_fresh_module('warnings', blocked=['_warnings'])
          c_warnings = import_fresh_module('warnings', fresh=['_warnings'])

     Added in version 3.1.

 -- Funzione: test.support.import_helper.import_module (name,
          deprecated=False, *, required_on=())

     This function imports and returns the named module.  Unlike a
     normal import, this function raises *note unittest.SkipTest: 11e6.
     if the module cannot be imported.

     Module and package deprecation messages are suppressed during this
     import if 'deprecated' is ‘True’.  If a module is required on a
     platform but optional for others, set 'required_on' to an iterable
     of platform prefixes which will be compared against *note
     sys.platform: 291.

     Added in version 3.1.

 -- Funzione: test.support.import_helper.modules_setup ()

     Return a copy of *note sys.modules: 17ce.

 -- Funzione: test.support.import_helper.modules_cleanup (oldmodules)

     Remove modules except for 'oldmodules' and ‘encodings’ in order to
     preserve internal cache.

 -- Funzione: test.support.import_helper.unload (name)

     Delete 'name' from ‘sys.modules’.

 -- Funzione: test.support.import_helper.make_legacy_pyc (source)

     Move a PEP 3147(1)/ PEP 488(2) pyc file to its legacy pyc location
     and return the file system path to the legacy pyc file.  The
     'source' value is the file system path to the source file.  It does
     not need to exist, however the PEP 3147/488 pyc file must exist.

 -- Classe: test.support.import_helper.CleanImport (*module_names)

     A context manager to force import to return a new module reference.
     This is useful for testing module-level behaviors, such as the
     emission of a *note DeprecationWarning: 1a3. on import.  Example
     usage:

          with CleanImport('foo'):
              importlib.import_module('foo')  # New reference.

 -- Classe: test.support.import_helper.DirsOnSysPath (*paths)

     A context manager to temporarily add directories to *note sys.path:
     3e4.

     This makes a copy of *note sys.path: 3e4, appends any directories
     given as positional arguments, then reverts *note sys.path: 3e4. to
     the copied settings when the context ends.

     Note that 'all' *note sys.path: 3e4. modifications in the body of
     the context manager, including replacement of the object, will be
     reverted at the end of the block.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3147/

   (2) https://peps.python.org/pep-0488/


File: python.info,  Node: test support warnings_helper — Utilities for warnings tests,  Prev: test support import_helper — Utilities for import tests,  Up: Development Tools

5.26.16 ‘test.support.warnings_helper’ — Utilities for warnings tests
---------------------------------------------------------------------

The *note test.support.warnings_helper: f1. module provides support for
warnings tests.

Added in version 3.10.

 -- Funzione: test.support.warnings_helper.ignore_warnings (*, category)

     Suppress warnings that are instances of 'category', which must be
     *note Warning: 26f5. or a subclass.  Roughly equivalent to *note
     warnings.catch_warnings(): 179. with *note
     warnings.simplefilter('ignore', category=category): 8d1.  For
     example:

          @warning_helper.ignore_warnings(category=DeprecationWarning)
          def test_suppress_warning():
              # do something

     Added in version 3.8.

 -- Funzione: test.support.warnings_helper.check_no_resource_warning
          (testcase)

     Context manager to check that no *note ResourceWarning: 54d. was
     raised.  You must remove the object which may emit *note
     ResourceWarning: 54d. before the end of the context manager.

 -- Funzione: test.support.warnings_helper.check_syntax_warning
          (testcase, statement, errtext='', *, lineno=1, offset=None)

     Test for syntax warning in 'statement' by attempting to compile
     'statement'.  Test also that the *note SyntaxWarning: 1ae. is
     emitted only once, and that it will be converted to a *note
     SyntaxError: 18e. when turned into error.  'testcase' is the *note
     unittest: 10c. instance for the test.  'errtext' is the regular
     expression which should match the string representation of the
     emitted *note SyntaxWarning: 1ae. and raised *note SyntaxError:
     18e.  If 'lineno' is not ‘None’, compares to the line of the
     warning and exception.  If 'offset' is not ‘None’, compares to the
     offset of the exception.

     Added in version 3.8.

 -- Funzione: test.support.warnings_helper.check_warnings (*filters,
          quiet=True)

     A convenience wrapper for *note warnings.catch_warnings(): 179.
     that makes it easier to test that a warning was correctly raised.
     It is approximately equivalent to calling
     ‘warnings.catch_warnings(record=True)’ with *note
     warnings.simplefilter(): 8d1. set to ‘always’ and with the option
     to automatically validate the results that are recorded.

     ‘check_warnings’ accepts 2-tuples of the form ‘("message regexp",
     WarningCategory)’ as positional arguments.  If one or more
     'filters' are provided, or if the optional keyword argument 'quiet'
     is ‘False’, it checks to make sure the warnings are as expected:
     each specified filter must match at least one of the warnings
     raised by the enclosed code or the test fails, and if any warnings
     are raised that do not match any of the specified filters the test
     fails.  To disable the first of these checks, set 'quiet' to
     ‘True’.

     If no arguments are specified, it defaults to:

          check_warnings(("", Warning), quiet=True)

     In this case all warnings are caught and no errors are raised.

     On entry to the context manager, a ‘WarningRecorder’ instance is
     returned.  The underlying warnings list from *note
     catch_warnings(): 179. is available via the recorder object’s *note
     warnings: 118. attribute.  As a convenience, the attributes of the
     object representing the most recent warning can also be accessed
     directly through the recorder object (see example below).  If no
     warning has been raised, then any of the attributes that would
     otherwise be expected on an object representing a warning will
     return ‘None’.

     The recorder object also has a ‘reset()’ method, which clears the
     warnings list.

     The context manager is designed to be used like this:

          with check_warnings(("assertion is always true", SyntaxWarning),
                              ("", UserWarning)):
              exec('assert(False, "Hey!")')
              warnings.warn(UserWarning("Hide me!"))

     In this case if either warning was not raised, or some other
     warning was raised, *note check_warnings(): 4731. would raise an
     error.

     When a test needs to look more deeply into the warnings, rather
     than just checking whether or not they occurred, code like this can
     be used:

          with check_warnings(quiet=True) as w:
              warnings.warn("foo")
              assert str(w.args[0]) == "foo"
              warnings.warn("bar")
              assert str(w.args[0]) == "bar"
              assert str(w.warnings[0].args[0]) == "foo"
              assert str(w.warnings[1].args[0]) == "bar"
              w.reset()
              assert len(w.warnings) == 0

     Here all warnings will be caught, and the test code tests the
     captured warnings directly.

     Cambiato nella versione 3.2: New optional arguments 'filters' and
     'quiet'.

 -- Classe: test.support.warnings_helper.WarningsRecorder

     Class used to record warnings for unit tests.  See documentation of
     *note check_warnings(): 4731. above for more details.


File: python.info,  Node: Debugging and Profiling,  Next: Software Packaging and Distribution,  Prev: Development Tools,  Up: The Python Standard Library

5.27 Debugging and Profiling
============================

These libraries help you with Python development: the debugger enables
you to step through code, analyze stack frames and set breakpoints etc.,
and the profilers run code and give you a detailed breakdown of
execution times, allowing you to identify bottlenecks in your programs.
Auditing events provide visibility into runtime behaviors that would
otherwise require intrusive debugging or patching.

* Menu:

* Audit events table::
* bdb — Debugger framework::
* faulthandler — Dump the Python traceback::
* pdb — The Python Debugger::
* The Python Profilers::
* timeit — Measure execution time of small code snippets::
* trace — Trace or track Python statement execution::
* tracemalloc — Trace memory allocations::


File: python.info,  Node: Audit events table,  Next: bdb — Debugger framework,  Up: Debugging and Profiling

5.27.1 Audit events table
-------------------------

This table contains all events raised by *note sys.audit(): 1903. or
*note PySys_Audit(): 613. calls throughout the CPython runtime and the
standard library.  These calls were added in 3.8 or later (see PEP
578(1)).

See *note sys.addaudithook(): 4738. and *note PySys_AddAuditHook():
4739. for information on handling these events.

'Dettaglio dell’implementazione di CPython:' This table is generated
from the CPython documentation, and may not represent events raised by
other implementations.  See your runtime specific documentation for
actual events raised.

Audit event                        Arguments                                                   References
                                                                                               
-------------------------------------------------------------------------------------------------------------------
                                                                                               
_thread.start_new_thread           ‘function’, ‘args’, ‘kwargs’                                *note [1]: 473a.
                                                                                               
                                                                                               
array.__new__                      ‘typecode’, ‘initializer’                                   *note [1]: 4bf.
                                                                                               
                                                                                               
builtins.breakpoint                ‘breakpointhook’                                            *note [1]: 271.
                                                                                               
                                                                                               
builtins.id                        ‘id’                                                        *note [1]: 162a.
                                                                                               
                                                                                               
builtins.input                     ‘prompt’                                                    *note [1]: 14e0.
                                                                                               
                                                                                               
builtins.input/result              ‘result’                                                    *note [1]: 14e0.
                                                                                               
                                                                                               
code.__new__                       ‘code’, ‘filename’, ‘name’, ‘argcount’,                     *note [1]: 32f.
                                   ‘posonlyargcount’, ‘kwonlyargcount’, ‘nlocals’,             
                                   ‘stacksize’, ‘flags’
                                   
                                                                                               
compile                            ‘source’, ‘filename’                                        *note [1]: 4b2.
                                                                                               
                                                                                               
cpython.PyConfig_Set               ‘name’, ‘value’                                             *note [1]: 37d.
                                                                                               
                                                                                               
cpython.PyInterpreterState_Clear                                                               *note [1]: 473b.
                                                                                               
                                                                                               
cpython.PyInterpreterState_New                                                                 *note [1]: 473c.
                                                                                               
                                                                                               
cpython._PySys_ClearAuditHooks                                                                 *note [1]: f13.
                                                                                               
                                                                                               
cpython.remote_debugger_script     ‘script_path’                                               *note [1]: 473d.
                                                                                               
                                                                                               
cpython.run_command                ‘command’                                                   *note [1]: 1a8.
                                                                                               
                                                                                               
cpython.run_file                   ‘filename’                                                  *note [1]: 473e.
                                                                                               
                                                                                               
cpython.run_interactivehook        ‘hook’                                                      *note [1]: 11ca.
                                                                                               
                                                                                               
cpython.run_module                 ‘module-name’                                               *note [1]: 23c.
                                                                                               
                                                                                               
cpython.run_startup                ‘filename’                                                  *note [1]: 1b8.
                                                                                               
                                                                                               
cpython.run_stdin                                                                              *note [1]: 473f.*note [2]: 4740.*note [3]: 4741.
                                                                                               
                                                                                               
ctypes.addressof                   ‘obj’                                                       *note [1]: 331b.
                                                                                               
                                                                                               
ctypes.call_function               ‘func_pointer’, ‘arguments’                                 *note [1]: 3315.
                                                                                               
                                                                                               
ctypes.cdata                       ‘address’                                                   *note [1]: 3326.
                                                                                               
                                                                                               
ctypes.cdata/buffer                ‘pointer’, ‘size’, ‘offset’                                 *note [1]: 332b.*note [2]: 332c.
                                                                                               
                                                                                               
ctypes.create_string_buffer        ‘init’, ‘size’                                              *note [1]: 32d3.
                                                                                               
                                                                                               
ctypes.create_unicode_buffer       ‘init’, ‘size’                                              *note [1]: 1d9c.
                                                                                               
                                                                                               
ctypes.dlopen                      ‘name’                                                      *note [1]: 3313.
                                                                                               
                                                                                               
ctypes.dlsym                       ‘library’, ‘name’                                           *note [1]: 3313.
                                                                                               
                                                                                               
ctypes.dlsym/handle                ‘handle’, ‘name’                                            *note [1]: 3313.
                                                                                               
                                                                                               
ctypes.get_errno                                                                               *note [1]: 330d.
                                                                                               
                                                                                               
ctypes.get_last_error                                                                          *note [1]: 330f.
                                                                                               
                                                                                               
ctypes.memoryview_at               ‘address’, ‘size’, ‘readonly’                               *note [1]: 4742.
                                                                                               
                                                                                               
ctypes.set_errno                   ‘errno’                                                     *note [1]: 330e.
                                                                                               
                                                                                               
ctypes.set_exception               ‘code’                                                      *note [1]: 3315.
                                                                                               
                                                                                               
ctypes.set_last_error              ‘error’                                                     *note [1]: 3310.
                                                                                               
                                                                                               
ctypes.string_at                   ‘ptr’, ‘size’                                               *note [1]: 1ec.
                                                                                               
                                                                                               
ctypes.wstring_at                  ‘ptr’, ‘size’                                               *note [1]: 3325.
                                                                                               
                                                                                               
ensurepip.bootstrap                ‘root’                                                      *note [1]: 4743.
                                                                                               
                                                                                               
exec                               ‘code_object’                                               *note [1]: 4a4.*note [2]: 4a3.
                                                                                               
                                                                                               
fcntl.fcntl                        ‘fd’, ‘cmd’, ‘arg’                                          *note [1]: 1839.
                                                                                               
                                                                                               
fcntl.flock                        ‘fd’, ‘operation’                                           *note [1]: 4744.
                                                                                               
                                                                                               
fcntl.ioctl                        ‘fd’, ‘request’, ‘arg’                                      *note [1]: 1682.
                                                                                               
                                                                                               
fcntl.lockf                        ‘fd’, ‘cmd’, ‘len’, ‘start’, ‘whence’                       *note [1]: 15f3.
                                                                                               
                                                                                               
ftplib.connect                     ‘self’, ‘host’, ‘port’                                      *note [1]: 3fe3.
                                                                                               
                                                                                               
ftplib.sendcmd                     ‘self’, ‘cmd’                                               *note [1]: 3fe8.*note [2]: 3fe9.
                                                                                               
                                                                                               
function.__new__                   ‘code’                                                      *note [1]: a85.
                                                                                               
                                                                                               
gc.get_objects                     ‘generation’                                                *note [1]: a06.
                                                                                               
                                                                                               
gc.get_referents                   ‘objs’                                                      *note [1]: a08.
                                                                                               
                                                                                               
gc.get_referrers                   ‘objs’                                                      *note [1]: a07.
                                                                                               
                                                                                               
glob.glob                          ‘pathname’, ‘recursive’                                     *note [1]: 5a0.*note [2]: a0a.
                                                                                               
                                                                                               
glob.glob/2                        ‘pathname’, ‘recursive’, ‘root_dir’, ‘dir_fd’               *note [1]: 5a0.*note [2]: a0a.
                                                                                               
                                                                                               
http.client.connect                ‘self’, ‘host’, ‘port’                                      *note [1]: 3fc6.
                                                                                               
                                                                                               
http.client.send                   ‘self’, ‘data’                                              *note [1]: 3fca.
                                                                                               
                                                                                               
imaplib.open                       ‘self’, ‘host’, ‘port’                                      *note [1]: b03.
                                                                                               
                                                                                               
imaplib.send                       ‘self’, ‘data’                                              *note [1]: 403b.
                                                                                               
                                                                                               
import                             ‘module’, ‘filename’, ‘sys.path’, ‘sys.meta_path’,          *note [1]: 7f9.
                                   ‘sys.path_hooks’                                            
                                   
                                                                                               
marshal.dumps                      ‘value’, ‘version’                                          *note [1]: 2d29.
                                                                                               
                                                                                               
marshal.load                                                                                   *note [1]: 1dde.
                                                                                               
                                                                                               
marshal.loads                      ‘bytes’                                                     *note [1]: 1dde.
                                                                                               
                                                                                               
mmap.__new__                       ‘fileno’, ‘length’, ‘access’, ‘offset’                      *note [1]: 51a.
                                                                                               
                                                                                               
msvcrt.get_osfhandle               ‘fd’                                                        *note [1]: 4745.
                                                                                               
                                                                                               
msvcrt.locking                     ‘fd’, ‘mode’, ‘nbytes’                                      *note [1]: 4746.
                                                                                               
                                                                                               
msvcrt.open_osfhandle              ‘handle’, ‘flags’                                           *note [1]: 4747.
                                                                                               
                                                                                               
object.__delattr__                 ‘obj’, ‘name’                                               *note [1]: 2363.
                                                                                               
                                                                                               
object.__getattr__                 ‘obj’, ‘name’                                               *note [1]: dcd.
                                                                                               
                                                                                               
object.__setattr__                 ‘obj’, ‘name’, ‘value’                                      *note [1]: 2362.
                                                                                               
                                                                                               
open                               ‘path’, ‘mode’, ‘flags’                                     *note [1]: 316.*note [2]: 741.*note [3]: f94.
                                                                                               
                                                                                               
os.add_dll_directory               ‘path’                                                      *note [1]: bdf.
                                                                                               
                                                                                               
os.chdir                           ‘path’                                                      *note [1]: 822.*note [2]: f8b.
                                                                                               
                                                                                               
os.chflags                         ‘path’, ‘flags’                                             *note [1]: 12f5.*note [2]: 305f.
                                                                                               
                                                                                               
os.chmod                           ‘path’, ‘mode’, ‘dir_fd’                                    *note [1]: 52a.*note [2]: 52b.*note [3]: 529.
                                                                                               
                                                                                               
os.chown                           ‘path’, ‘uid’, ‘gid’, ‘dir_fd’                              *note [1]: 12f6.*note [2]: f8c.*note [3]: 3060.
                                                                                               
                                                                                               
os.exec                            ‘path’, ‘args’, ‘env’                                       *note [1]: 3099.
                                                                                               
                                                                                               
os.fork                                                                                        *note [1]: 4b6.
                                                                                               
                                                                                               
os.forkpty                                                                                     *note [1]: 4b7.
                                                                                               
                                                                                               
os.fwalk                           ‘top’, ‘topdown’, ‘onerror’, ‘follow_symlinks’, ‘dir_fd’    *note [1]: d54.
                                                                                               
                                                                                               
os.getxattr                        ‘path’, ‘attribute’                                         *note [1]: 130c.
                                                                                               
                                                                                               
os.kill                            ‘pid’, ‘sig’                                                *note [1]: 156f.
                                                                                               
                                                                                               
os.killpg                          ‘pgid’, ‘sig’                                               *note [1]: 1da3.
                                                                                               
                                                                                               
os.link                            ‘src’, ‘dst’, ‘src_dir_fd’, ‘dst_dir_fd’                    *note [1]: 12f7.
                                                                                               
                                                                                               
os.listdir                         ‘path’                                                      *note [1]: 1302.
                                                                                               
                                                                                               
os.listdrives                                                                                  *note [1]: 6c6.
                                                                                               
                                                                                               
os.listmounts                      ‘volume’                                                    *note [1]: 6c8.
                                                                                               
                                                                                               
os.listvolumes                                                                                 *note [1]: 6c7.
                                                                                               
                                                                                               
os.listxattr                       ‘path’                                                      *note [1]: 130d.
                                                                                               
                                                                                               
os.lockf                           ‘fd’, ‘cmd’, ‘len’                                          *note [1]: 131b.
                                                                                               
                                                                                               
os.mkdir                           ‘path’, ‘mode’, ‘dir_fd’                                    *note [1]: 52d.*note [2]: 52c.
                                                                                               
                                                                                               
os.posix_spawn                     ‘path’, ‘argv’, ‘env’                                       *note [1]: 52f.*note [2]: 1df9.
                                                                                               
                                                                                               
os.putenv                          ‘key’, ‘value’                                              *note [1]: 25b.
                                                                                               
                                                                                               
os.remove                          ‘path’, ‘dir_fd’                                            *note [1]: 12f8.*note [2]: 3064.*note [3]: 12fd.
                                                                                               
                                                                                               
os.removexattr                     ‘path’, ‘attribute’                                         *note [1]: 130e.
                                                                                               
                                                                                               
os.rename                          ‘src’, ‘dst’, ‘src_dir_fd’, ‘dst_dir_fd’                    *note [1]: 12f9.*note [2]: 3065.*note [3]: 12fa.
                                                                                               
                                                                                               
os.rmdir                           ‘path’, ‘dir_fd’                                            *note [1]: 12fb.
                                                                                               
                                                                                               
os.scandir                         ‘path’                                                      *note [1]: c56.
                                                                                               
                                                                                               
os.setxattr                        ‘path’, ‘attribute’, ‘value’, ‘flags’                       *note [1]: 130f.
                                                                                               
                                                                                               
os.spawn                           ‘mode’, ‘path’, ‘args’, ‘env’                               *note [1]: 31b.
                                                                                               
                                                                                               
os.startfile                       ‘path’, ‘operation’                                         *note [1]: 1c6b.
                                                                                               
                                                                                               
os.startfile/2                     ‘path’, ‘operation’, ‘arguments’, ‘cwd’, ‘show_cmd’         *note [1]: 1c6b.
                                                                                               
                                                                                               
os.symlink                         ‘src’, ‘dst’, ‘dir_fd’                                      *note [1]: 12fc.
                                                                                               
                                                                                               
os.system                          ‘command’                                                   *note [1]: 1664.
                                                                                               
                                                                                               
os.truncate                        ‘fd’, ‘length’                                              *note [1]: f91.*note [2]: 103e.
                                                                                               
                                                                                               
os.unsetenv                        ‘key’                                                       *note [1]: 25c.
                                                                                               
                                                                                               
os.utime                           ‘path’, ‘times’, ‘ns’, ‘dir_fd’                             *note [1]: 12fe.
                                                                                               
                                                                                               
os.walk                            ‘top’, ‘topdown’, ‘onerror’, ‘followlinks’                  *note [1]: 6d1.
                                                                                               
                                                                                               
pathlib.Path.glob                  ‘self’, ‘pattern’                                           *note [1]: 538.
                                                                                               
                                                                                               
pathlib.Path.rglob                 ‘self’, ‘pattern’                                           *note [1]: 539.
                                                                                               
                                                                                               
pdb.Pdb                                                                                        *note [1]: 273.
                                                                                               
                                                                                               
pickle.find_class                  ‘module’, ‘name’                                            *note [1]: 2cff.
                                                                                               
                                                                                               
poplib.connect                     ‘self’, ‘host’, ‘port’                                      *note [1]: b1f.*note [2]: b20.
                                                                                               
                                                                                               
poplib.putline                     ‘self’, ‘line’                                              *note [1]: b1f.*note [2]: b20.
                                                                                               
                                                                                               
pty.spawn                          ‘argv’                                                      *note [1]: 1184.
                                                                                               
                                                                                               
resource.prlimit                   ‘pid’, ‘resource’, ‘limits’                                 *note [1]: 118c.
                                                                                               
                                                                                               
resource.setrlimit                 ‘resource’, ‘limits’                                        *note [1]: 17ae.
                                                                                               
                                                                                               
setopencodehook                                                                                *note [1]: 1a82.
                                                                                               
                                                                                               
shutil.chown                       ‘path’, ‘user’, ‘group’                                     *note [1]: 549.
                                                                                               
                                                                                               
shutil.copyfile                    ‘src’, ‘dst’                                                *note [1]: c51.*note [2]: c52.*note [3]: c50.
                                                                                               
                                                                                               
shutil.copymode                    ‘src’, ‘dst’                                                *note [1]: c51.*note [2]: 1a0c.
                                                                                               
                                                                                               
shutil.copystat                    ‘src’, ‘dst’                                                *note [1]: c52.*note [2]: 1336.
                                                                                               
                                                                                               
shutil.copytree                    ‘src’, ‘dst’                                                *note [1]: c20.
                                                                                               
                                                                                               
shutil.make_archive                ‘base_name’, ‘format’, ‘root_dir’, ‘base_dir’               *note [1]: 6db.
                                                                                               
                                                                                               
shutil.move                        ‘src’, ‘dst’                                                *note [1]: c53.
                                                                                               
                                                                                               
shutil.rmtree                      ‘path’, ‘dir_fd’                                            *note [1]: 356.
                                                                                               
                                                                                               
shutil.unpack_archive              ‘filename’, ‘extract_dir’, ‘format’                         *note [1]: 697.
                                                                                               
                                                                                               
signal.pthread_kill                ‘thread_id’, ‘signalnum’                                    *note [1]: 1339.
                                                                                               
                                                                                               
smtplib.connect                    ‘self’, ‘host’, ‘port’                                      *note [1]: 1d97.
                                                                                               
                                                                                               
smtplib.send                       ‘self’, ‘data’                                              *note [1]: b29.
                                                                                               
                                                                                               
socket.__new__                     ‘self’, ‘family’, ‘type’, ‘protocol’                        *note [1]: fa3.
                                                                                               
                                                                                               
socket.bind                        ‘self’, ‘address’                                           *note [1]: 1741.
                                                                                               
                                                                                               
socket.connect                     ‘self’, ‘address’                                           *note [1]: fa5.*note [2]: 1740.
                                                                                               
                                                                                               
socket.getaddrinfo                 ‘host’, ‘port’, ‘family’, ‘type’, ‘protocol’                *note [1]: 1aab.
                                                                                               
                                                                                               
socket.gethostbyaddr               ‘ip_address’                                                *note [1]: 1c6c.
                                                                                               
                                                                                               
socket.gethostbyname               ‘hostname’                                                  *note [1]: 397c.*note [2]: 1c6d.
                                                                                               
                                                                                               
socket.gethostname                                                                             *note [1]: 300b.
                                                                                               
                                                                                               
socket.getnameinfo                 ‘sockaddr’                                                  *note [1]: 1a22.
                                                                                               
                                                                                               
socket.getservbyname               ‘servicename’, ‘protocolname’                               *note [1]: 397e.
                                                                                               
                                                                                               
socket.getservbyport               ‘port’, ‘protocolname’                                      *note [1]: 397f.
                                                                                               
                                                                                               
socket.sendmsg                     ‘self’, ‘address’                                           *note [1]: 6a2.
                                                                                               
                                                                                               
socket.sendto                      ‘self’, ‘address’                                           *note [1]: fab.
                                                                                               
                                                                                               
socket.sethostname                 ‘name’                                                      *note [1]: 1343.
                                                                                               
                                                                                               
sqlite3.connect                    ‘database’                                                  *note [1]: 5a6.
                                                                                               
                                                                                               
sqlite3.connect/handle             ‘connection_handle’                                         *note [1]: 5a6.
                                                                                               
                                                                                               
sqlite3.enable_load_extension      ‘connection’, ‘enabled’                                     *note [1]: a41.
                                                                                               
                                                                                               
sqlite3.load_extension             ‘connection’, ‘path’                                        *note [1]: 6e0.
                                                                                               
                                                                                               
subprocess.Popen                   ‘executable’, ‘args’, ‘cwd’, ‘env’                          *note [1]: 4b8.
                                                                                               
                                                                                               
sys._current_exceptions                                                                        *note [1]: 6ea.
                                                                                               
                                                                                               
sys._current_frames                                                                            *note [1]: 163a.
                                                                                               
                                                                                               
sys._getframe                      ‘frame’                                                     *note [1]: 8f1.
                                                                                               
                                                                                               
sys._getframemodulename            ‘depth’                                                     *note [1]: 1ac7.
                                                                                               
                                                                                               
sys.addaudithook                                                                               *note [1]: 4739.*note [2]: 4738.
                                                                                               
                                                                                               
sys.excepthook                     ‘hook’, ‘type’, ‘value’, ‘traceback’                        *note [1]: a0e.
                                                                                               
                                                                                               
sys.monitoring.register_callback   ‘func’                                                      *note [1]: 4748.
                                                                                               
                                                                                               
sys.remote_exec                    ‘pid’                                                       *note [1]: 4749.
                                                                                               
                                                                                               
sys.set_asyncgen_hooks_finalizer                                                               *note [1]: 1985.
                                                                                               
                                                                                               
sys.set_asyncgen_hooks_firstiter                                                               *note [1]: 1985.
                                                                                               
                                                                                               
sys.setprofile                                                                                 *note [1]: 1705.
                                                                                               
                                                                                               
sys.settrace                                                                                   *note [1]: 2e1.
                                                                                               
                                                                                               
sys.unraisablehook                 ‘hook’, ‘unraisable’                                        *note [1]: 508.
                                                                                               
                                                                                               
syslog.closelog                                                                                *note [1]: 762.
                                                                                               
                                                                                               
syslog.openlog                     ‘ident’, ‘logoption’, ‘facility’                            *note [1]: 761.
                                                                                               
                                                                                               
syslog.setlogmask                  ‘maskpri’                                                   *note [1]: 474a.
                                                                                               
                                                                                               
syslog.syslog                      ‘priority’, ‘message’                                       *note [1]: 763.
                                                                                               
                                                                                               
tempfile.mkdtemp                   ‘fullpath’                                                  *note [1]: 143c.*note [2]: 52e.
                                                                                               
                                                                                               
tempfile.mkstemp                   ‘fullpath’                                                  *note [1]: 6ee.*note [2]: 2caf.*note [3]: 2cb0.
                                                                                               
                                                                                               
time.sleep                         ‘secs’                                                      *note [1]: 474b.
                                                                                               
                                                                                               
urllib.Request                     ‘fullurl’, ‘data’, ‘headers’, ‘method’                      *note [1]: 307.
                                                                                               
                                                                                               
webbrowser.open                    ‘url’                                                       *note [1]: 1871.
                                                                                               
                                                                                               
winreg.ConnectRegistry             ‘computer_name’, ‘key’                                      *note [1]: 474c.
                                                                                               
                                                                                               
winreg.CreateKey                   ‘key’, ‘sub_key’, ‘access’                                  *note [1]: 474d.*note [2]: 156a.
                                                                                               
                                                                                               
winreg.DeleteKey                   ‘key’, ‘sub_key’, ‘access’                                  *note [1]: 474e.*note [2]: 156b.
                                                                                               
                                                                                               
winreg.DeleteValue                 ‘key’, ‘value’                                              *note [1]: 474f.
                                                                                               
                                                                                               
winreg.DisableReflectionKey        ‘key’                                                       *note [1]: 156c.
                                                                                               
                                                                                               
winreg.EnableReflectionKey         ‘key’                                                       *note [1]: 156d.
                                                                                               
                                                                                               
winreg.EnumKey                     ‘key’, ‘index’                                              *note [1]: 4750.
                                                                                               
                                                                                               
winreg.EnumValue                   ‘key’, ‘index’                                              *note [1]: 4751.
                                                                                               
                                                                                               
winreg.ExpandEnvironmentStrings    ‘str’                                                       *note [1]: 15ff.
                                                                                               
                                                                                               
winreg.LoadKey                     ‘key’, ‘sub_key’, ‘file_name’                               *note [1]: 4752.
                                                                                               
                                                                                               
winreg.OpenKey                     ‘key’, ‘sub_key’, ‘access’                                  *note [1]: 4753.
                                                                                               
                                                                                               
winreg.OpenKey/result              ‘key’                                                       *note [1]: 474d.*note [2]: 156a.*note [3]: 4753.
                                                                                               
                                                                                               
winreg.PyHKEY.Detach               ‘key’                                                       *note [1]: 4754.
                                                                                               
                                                                                               
winreg.QueryInfoKey                ‘key’                                                       *note [1]: 4755.
                                                                                               
                                                                                               
winreg.QueryReflectionKey          ‘key’                                                       *note [1]: 156e.
                                                                                               
                                                                                               
winreg.QueryValue                  ‘key’, ‘sub_key’, ‘value_name’                              *note [1]: 4756.*note [2]: 176b.
                                                                                               
                                                                                               
winreg.SaveKey                     ‘key’, ‘file_name’                                          *note [1]: 4757.
                                                                                               
                                                                                               
winreg.SetValue                    ‘key’, ‘sub_key’, ‘type’, ‘value’                           *note [1]: 4758.*note [2]: 1aeb.
                                                                                               

The following events are raised internally and do not correspond to any
public API of CPython:

Audit event                      Arguments
                                 
---------------------------------------------------------------------------------
                                 
_winapi.CreateFile               ‘file_name’, ‘desired_access’, ‘share_mode’,
                                 ‘creation_disposition’,
                                 ‘flags_and_attributes’
                                 
                                 
_winapi.CreateJunction           ‘src_path’, ‘dst_path’
                                 
                                 
_winapi.CreateNamedPipe          ‘name’, ‘open_mode’, ‘pipe_mode’
                                 
                                 
_winapi.CreatePipe

_winapi.CreateProcess            ‘application_name’, ‘command_line’,
                                 ‘current_directory’
                                 
                                 
_winapi.OpenProcess              ‘process_id’, ‘desired_access’
                                 
                                 
_winapi.TerminateProcess         ‘handle’, ‘exit_code’
                                 
                                 
_posixsubprocess.fork_exec       ‘exec_list’, ‘args’, ‘env’
                                 
                                 
ctypes.PyObj_FromPtr             ‘obj’
                                 

Added in version 3.14: The ‘_posixsubprocess.fork_exec’ internal audit
event.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0578/


File: python.info,  Node: bdb — Debugger framework,  Next: faulthandler — Dump the Python traceback,  Prev: Audit events table,  Up: Debugging and Profiling

5.27.2 ‘bdb’ — Debugger framework
---------------------------------

'Source code:' Lib/bdb.py(1)

__________________________________________________________________

The *note bdb: 10. module handles basic debugger functions, like setting
breakpoints or managing execution via the debugger.

The following exception is defined:

 -- Eccezione: bdb.BdbQuit

     Exception raised by the *note Bdb: 2d5. class for quitting the
     debugger.

The *note bdb: 10. module also defines two classes:

 -- Classe: bdb.Breakpoint (self, file, line, temporary=False,
          cond=None, funcname=None)

     This class implements temporary breakpoints, ignore counts,
     disabling and (re-)enabling, and conditionals.

     Breakpoints are indexed by number through a list called *note
     bpbynumber: 475d. and by ‘(file, line)’ pairs through *note bplist:
     475e.  The former points to a single instance of class *note
     Breakpoint: 475c.  The latter points to a list of such instances
     since there may be more than one breakpoint per line.

     When creating a breakpoint, its associated *note file name: 475f.
     should be in canonical form.  If a *note funcname: 4760. is
     defined, a breakpoint *note hit: 4761. will be counted when the
     first line of that function is executed.  A *note conditional:
     4762. breakpoint always counts a *note hit: 4761.

     *note Breakpoint: 475c. instances have the following methods:

      -- Metodo: deleteMe ()

          Delete the breakpoint from the list associated to a file/line.
          If it is the last breakpoint in that position, it also deletes
          the entry for the file/line.

      -- Metodo: enable ()

          Mark the breakpoint as enabled.

      -- Metodo: disable ()

          Mark the breakpoint as disabled.

      -- Metodo: bpformat ()

          Return a string with all the information about the breakpoint,
          nicely formatted:

             * Breakpoint number.

             * Temporary status (del or keep).

             * File/line position.

             * Break condition.

             * Number of times to ignore.

             * Number of times hit.

          Added in version 3.2.

      -- Metodo: bpprint (out=None)

          Print the output of *note bpformat(): 4766. to the file 'out',
          or if it is ‘None’, to standard output.

     *note Breakpoint: 475c. instances have the following attributes:

      -- Attributo: file

          File name of the *note Breakpoint: 475c.

      -- Attributo: line

          Line number of the *note Breakpoint: 475c. within *note file:
          475f.

      -- Attributo: temporary

          ‘True’ if a *note Breakpoint: 475c. at (file, line) is
          temporary.

      -- Attributo: cond

          Condition for evaluating a *note Breakpoint: 475c. at (file,
          line).

      -- Attributo: funcname

          Function name that defines whether a *note Breakpoint: 475c.
          is hit upon entering the function.

      -- Attributo: enabled

          ‘True’ if *note Breakpoint: 475c. is enabled.

      -- Attributo: bpbynumber

          Numeric index for a single instance of a *note Breakpoint:
          475c.

      -- Attributo: bplist

          Dictionary of *note Breakpoint: 475c. instances indexed by
          (*note file: 475f, *note line: 4768.) tuples.

      -- Attributo: ignore

          Number of times to ignore a *note Breakpoint: 475c.

      -- Attributo: hits

          Count of the number of times a *note Breakpoint: 475c. has
          been hit.

 -- Classe: bdb.Bdb (skip=None, backend='settrace')

     The *note Bdb: 2d5. class acts as a generic Python debugger base
     class.

     This class takes care of the details of the trace facility; a
     derived class should implement user interaction.  The standard
     debugger class (*note pdb.Pdb: 273.) is an example.

     The 'skip' argument, if given, must be an iterable of glob-style
     module name patterns.  The debugger will not step into frames that
     originate in a module that matches one of these patterns.  Whether
     a frame is considered to originate in a certain module is
     determined by the ‘__name__’ in the frame globals.

     The 'backend' argument specifies the backend to use for *note Bdb:
     2d5.  It can be either ‘'settrace'’ or ‘'monitoring'’.
     ‘'settrace'’ uses *note sys.settrace(): 2e1. which has the best
     backward compatibility.  The ‘'monitoring'’ backend uses the new
     *note sys.monitoring: e0. that was introduced in Python 3.12, which
     can be much more efficient because it can disable unused events.
     We are trying to keep the exact interfaces for both backends, but
     there are some differences.  The debugger developers are encouraged
     to use the ‘'monitoring'’ backend to achieve better performance.

     Cambiato nella versione 3.1: Added the 'skip' parameter.

     Cambiato nella versione 3.14: Added the 'backend' parameter.

     The following methods of *note Bdb: 2d5. normally don’t need to be
     overridden.

      -- Metodo: canonic (filename)

          Return canonical form of 'filename'.

          For real file names, the canonical form is an
          operating-system-dependent, *note case-normalized: 2c3c. *note
          absolute path: 1522.  A 'filename' with angle brackets, such
          as ‘"<stdin>"’ generated in interactive mode, is returned
          unchanged.

      -- Metodo: start_trace (self)

          Start tracing.  For ‘'settrace'’ backend, this method is
          equivalent to ‘sys.settrace(self.trace_dispatch)’

          Added in version 3.14.

      -- Metodo: stop_trace (self)

          Stop tracing.  For ‘'settrace'’ backend, this method is
          equivalent to ‘sys.settrace(None)’

          Added in version 3.14.

      -- Metodo: reset ()

          Set the ‘botframe’, ‘stopframe’, ‘returnframe’ and *note
          quitting: 4770. attributes with values ready to start
          debugging.

      -- Metodo: trace_dispatch (frame, event, arg)

          This function is installed as the trace function of debugged
          frames.  Its return value is the new trace function (in most
          cases, that is, itself).

          The default implementation decides how to dispatch a frame,
          depending on the type of event (passed as a string) that is
          about to be executed.  'event' can be one of the following:

             * ‘"line"’: A new line of code is going to be executed.

             * ‘"call"’: A function is about to be called, or another
               code block entered.

             * ‘"return"’: A function or other code block is about to
               return.

             * ‘"exception"’: An exception has occurred.

             * ‘"c_call"’: A C function is about to be called.

             * ‘"c_return"’: A C function has returned.

             * ‘"c_exception"’: A C function has raised an exception.

          For the Python events, specialized functions (see below) are
          called.  For the C events, no action is taken.

          The 'arg' parameter depends on the previous event.

          See the documentation for *note sys.settrace(): 2e1. for more
          information on the trace function.  For more information on
          code and frame objects, refer to *note The standard type
          hierarchy: 2318.

      -- Metodo: dispatch_line (frame)

          If the debugger should stop on the current line, invoke the
          *note user_line(): 4773. method (which should be overridden in
          subclasses).  Raise a *note BdbQuit: 278. exception if the
          *note quitting: 4770. flag is set (which can be set from *note
          user_line(): 4773.).  Return a reference to the *note
          trace_dispatch(): 4771. method for further tracing in that
          scope.

      -- Metodo: dispatch_call (frame, arg)

          If the debugger should stop on this function call, invoke the
          *note user_call(): 4775. method (which should be overridden in
          subclasses).  Raise a *note BdbQuit: 278. exception if the
          *note quitting: 4770. flag is set (which can be set from *note
          user_call(): 4775.).  Return a reference to the *note
          trace_dispatch(): 4771. method for further tracing in that
          scope.

      -- Metodo: dispatch_return (frame, arg)

          If the debugger should stop on this function return, invoke
          the *note user_return(): 4777. method (which should be
          overridden in subclasses).  Raise a *note BdbQuit: 278.
          exception if the *note quitting: 4770. flag is set (which can
          be set from *note user_return(): 4777.).  Return a reference
          to the *note trace_dispatch(): 4771. method for further
          tracing in that scope.

      -- Metodo: dispatch_exception (frame, arg)

          If the debugger should stop at this exception, invokes the
          *note user_exception(): 4779. method (which should be
          overridden in subclasses).  Raise a *note BdbQuit: 278.
          exception if the *note quitting: 4770. flag is set (which can
          be set from *note user_exception(): 4779.).  Return a
          reference to the *note trace_dispatch(): 4771. method for
          further tracing in that scope.

     Normally derived classes don’t override the following methods, but
     they may if they want to redefine the definition of stopping and
     breakpoints.

      -- Metodo: is_skipped_module (module_name)

          Return ‘True’ if 'module_name' matches any skip pattern.

      -- Metodo: stop_here (frame)

          Return ‘True’ if 'frame' is below the starting frame in the
          stack.

      -- Metodo: break_here (frame)

          Return ‘True’ if there is an effective breakpoint for this
          line.

          Check whether a line or function breakpoint exists and is in
          effect.  Delete temporary breakpoints based on information
          from *note effective(): 477d.

      -- Metodo: break_anywhere (frame)

          Return ‘True’ if any breakpoint exists for 'frame'’s filename.

     Derived classes should override these methods to gain control over
     debugger operation.

      -- Metodo: user_call (frame, argument_list)

          Called from *note dispatch_call(): 4774. if a break might stop
          inside the called function.

          'argument_list' is not used anymore and will always be ‘None’.
          The argument is kept for backwards compatibility.

      -- Metodo: user_line (frame)

          Called from *note dispatch_line(): 4772. when either *note
          stop_here(): 477b. or *note break_here(): 477c. returns
          ‘True’.

      -- Metodo: user_return (frame, return_value)

          Called from *note dispatch_return(): 4776. when *note
          stop_here(): 477b. returns ‘True’.

      -- Metodo: user_exception (frame, exc_info)

          Called from *note dispatch_exception(): 4778. when *note
          stop_here(): 477b. returns ‘True’.

      -- Metodo: do_clear (arg)

          Handle how a breakpoint must be removed when it is a temporary
          one.

          This method must be implemented by derived classes.

     Derived classes and clients can call the following methods to
     affect the stepping state.

      -- Metodo: set_step ()

          Stop after one line of code.

      -- Metodo: set_next (frame)

          Stop on the next line in or below the given frame.

      -- Metodo: set_return (frame)

          Stop when returning from the given frame.

      -- Metodo: set_until (frame, lineno=None)

          Stop when the line with the 'lineno' greater than the current
          one is reached or when returning from current frame.

      -- Metodo: set_trace ([frame])

          Start debugging from 'frame'.  If 'frame' is not specified,
          debugging starts from caller’s frame.

          Cambiato nella versione 3.13: *note set_trace(): 4785. will
          enter the debugger immediately, rather than on the next line
          of code to be executed.

      -- Metodo: set_continue ()

          Stop only at breakpoints or when finished.  If there are no
          breakpoints, set the system trace function to ‘None’.

      -- Metodo: set_quit ()

          Set the ‘quitting’ attribute to ‘True’.  This raises *note
          BdbQuit: 278. in the next call to one of the ‘dispatch_*()’
          methods.

     Derived classes and clients can call the following methods to
     manipulate breakpoints.  These methods return a string containing
     an error message if something went wrong, or ‘None’ if all is well.

      -- Metodo: set_break (filename, lineno, temporary=False,
               cond=None, funcname=None)

          Set a new breakpoint.  If the 'lineno' line doesn’t exist for
          the 'filename' passed as argument, return an error message.
          The 'filename' should be in canonical form, as described in
          the *note canonic(): 476c. method.

      -- Metodo: clear_break (filename, lineno)

          Delete the breakpoints in 'filename' and 'lineno'.  If none
          were set, return an error message.

      -- Metodo: clear_bpbynumber (arg)

          Delete the breakpoint which has the index 'arg' in the *note
          Breakpoint.bpbynumber: 475d.  If 'arg' is not numeric or out
          of range, return an error message.

      -- Metodo: clear_all_file_breaks (filename)

          Delete all breakpoints in 'filename'.  If none were set,
          return an error message.

      -- Metodo: clear_all_breaks ()

          Delete all existing breakpoints.  If none were set, return an
          error message.

      -- Metodo: get_bpbynumber (arg)

          Return a breakpoint specified by the given number.  If 'arg'
          is a string, it will be converted to a number.  If 'arg' is a
          non-numeric string, if the given breakpoint never existed or
          has been deleted, a *note ValueError: 2ec. is raised.

          Added in version 3.2.

      -- Metodo: get_break (filename, lineno)

          Return ‘True’ if there is a breakpoint for 'lineno' in
          'filename'.

      -- Metodo: get_breaks (filename, lineno)

          Return all breakpoints for 'lineno' in 'filename', or an empty
          list if none are set.

      -- Metodo: get_file_breaks (filename)

          Return all breakpoints in 'filename', or an empty list if none
          are set.

      -- Metodo: get_all_breaks ()

          Return all breakpoints that are set.

     Derived classes and clients can call the following methods to
     disable and restart events to achieve better performance.  These
     methods only work when using the ‘'monitoring'’ backend.

      -- Metodo: disable_current_event ()

          Disable the current event until the next time *note
          restart_events(): 4792. is called.  This is helpful when the
          debugger is not interested in the current line.

          Added in version 3.14.

      -- Metodo: restart_events ()

          Restart all the disabled events.  This function is
          automatically called in ‘dispatch_*’ methods after ‘user_*’
          methods are called.  If the ‘dispatch_*’ methods are not
          overridden, the disabled events will be restarted after each
          user interaction.

          Added in version 3.14.

     Derived classes and clients can call the following methods to get a
     data structure representing a stack trace.

      -- Metodo: get_stack (f, t)

          Return a list of (frame, lineno) tuples in a stack trace, and
          a size.

          The most recently called frame is last in the list.  The size
          is the number of frames below the frame where the debugger was
          invoked.

      -- Metodo: format_stack_entry (frame_lineno, lprefix=': ')

          Return a string with information about a stack entry, which is
          a ‘(frame, lineno)’ tuple.  The return string contains:

             * The canonical filename which contains the frame.

             * The function name or ‘"<lambda>"’.

             * The input arguments.

             * The return value.

             * The line of code (if it exists).

     The following two methods can be called by clients to use a
     debugger to debug a *note statement: 2be2, given as a string.

      -- Metodo: run (cmd, globals=None, locals=None)

          Debug a statement executed via the *note exec(): 4a3.
          function.  'globals' defaults to ‘__main__.__dict__’, 'locals'
          defaults to 'globals'.

      -- Metodo: runeval (expr, globals=None, locals=None)

          Debug an expression executed via the *note eval(): 4a4.
          function.  'globals' and 'locals' have the same meaning as in
          *note run(): 4795.

      -- Metodo: runctx (cmd, globals, locals)

          For backwards compatibility.  Calls the *note run(): 4795.
          method.

      -- Metodo: runcall (func, /, *args, **kwds)

          Debug a single function call, and return its result.

Finally, the module defines the following functions:

 -- Funzione: bdb.checkfuncname (b, frame)

     Return ‘True’ if we should break here, depending on the way the
     *note Breakpoint: 475c. 'b' was set.

     If it was set via line number, it checks if *note b.line: 4768. is
     the same as the one in 'frame'.  If the breakpoint was set via
     *note function name: 4760, we have to check we are in the right
     'frame' (the right function) and if we are on its first executable
     line.

 -- Funzione: bdb.effective (file, line, frame)

     Return ‘(active breakpoint, delete temporary flag)’ or ‘(None,
     None)’ as the breakpoint to act upon.

     The 'active breakpoint' is the first entry in *note bplist: 475e.
     for the (*note file: 475f, *note line: 4768.) (which must exist)
     that is *note enabled: 476a, for which *note checkfuncname(): 4798.
     is true, and that has neither a false *note condition: 4762. nor
     positive *note ignore: 476b. count.  The 'flag', meaning that a
     temporary breakpoint should be deleted, is ‘False’ only when the
     *note cond: 4762. cannot be evaluated (in which case, *note ignore:
     476b. count is ignored).

     If no such entry exists, then ‘(None, None)’ is returned.

 -- Funzione: bdb.set_trace ()

     Start debugging with a *note Bdb: 2d5. instance from caller’s
     frame.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/bdb.py


File: python.info,  Node: faulthandler — Dump the Python traceback,  Next: pdb — The Python Debugger,  Prev: bdb — Debugger framework,  Up: Debugging and Profiling

5.27.3 ‘faulthandler’ — Dump the Python traceback
-------------------------------------------------

Added in version 3.3.

__________________________________________________________________

This module contains functions to dump Python tracebacks explicitly, on
a fault, after a timeout, or on a user signal.  Call *note
faulthandler.enable(): 20f. to install fault handlers for the *note
SIGSEGV: 1282, *note SIGFPE: 1283, *note SIGABRT: 1284, *note SIGBUS:
1285, and *note SIGILL: 1286. signals.  You can also enable them at
startup by setting the *note PYTHONFAULTHANDLER: 1287. environment
variable or by using the *note -X: 16f. ‘faulthandler’ command line
option.

The fault handler is compatible with system fault handlers like Apport
or the Windows fault handler.  The module uses an alternative stack for
signal handlers if the ‘sigaltstack()’ function is available.  This
allows it to dump the traceback even on a stack overflow.

The fault handler is called on catastrophic cases and therefore can only
use signal-safe functions (e.g.  it cannot allocate memory on the heap).
Because of this limitation traceback dumping is minimal compared to
normal Python tracebacks:

   * Only ASCII is supported.  The ‘backslashreplace’ error handler is
     used on encoding.

   * Each string is limited to 500 characters.

   * Only the filename, the function name and the line number are
     displayed.  (no source code)

   * It is limited to 100 frames and 100 threads.

   * The order is reversed: the most recent call is shown first.

By default, the Python traceback is written to *note sys.stderr: b35.
To see tracebacks, applications must be run in the terminal.  A log file
can alternatively be passed to *note faulthandler.enable(): 20f.

The module is implemented in C, so tracebacks can be dumped on a crash
or when Python is deadlocked.

The *note Python Development Mode: 509. calls *note
faulthandler.enable(): 20f. at Python startup.

Vedi anche
..........

Module *note pdb: aa.

     Interactive source code debugger for Python programs.

Module *note traceback: 104.

     Standard interface to extract, format and print stack traces of
     Python programs.

* Menu:

* Dumping the traceback::
* Dumping the C stack::
* Fault handler state::
* Dumping the tracebacks after a timeout::
* Dumping the traceback on a user signal::
* Issue with file descriptors::
* Example: Example<13>.


File: python.info,  Node: Dumping the traceback,  Next: Dumping the C stack,  Up: faulthandler — Dump the Python traceback

5.27.3.1 Dumping the traceback
..............................

 -- Funzione: faulthandler.dump_traceback (file=sys.stderr,
          all_threads=True)

     Dump the tracebacks of all threads into 'file'.  If 'all_threads'
     is ‘False’, dump only the current thread.

     Vedi anche
     ..........

     *note traceback.print_tb(): 1087, which can be used to print a
     traceback object.

     Cambiato nella versione 3.5: Added support for passing file
     descriptor to this function.


File: python.info,  Node: Dumping the C stack,  Next: Fault handler state,  Prev: Dumping the traceback,  Up: faulthandler — Dump the Python traceback

5.27.3.2 Dumping the C stack
............................

Added in version 3.14.

 -- Funzione: faulthandler.dump_c_stack (file=sys.stderr)

     Dump the C stack trace of the current thread into 'file'.

     If the Python build does not support it or the operating system
     does not provide a stack trace, then this prints an error in place
     of a dumped C stack.

* Menu:

* C Stack Compatibility::


File: python.info,  Node: C Stack Compatibility,  Up: Dumping the C stack

5.27.3.3 C Stack Compatibility
..............................

If the system does not support the C-level ‘backtrace(3)(1)’ or
‘dladdr1(3)(2)’, then C stack dumps will not work.  An error will be
printed instead of the stack.

Additionally, some compilers do not support *note CPython’s: 906.
implementation of C stack dumps.  As a result, a different error may be
printed instead of the stack, even if the operating system supports
dumping stacks.

     Nota: Dumping C stacks can be arbitrarily slow, depending on the
     DWARF level of the binaries in the call stack.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/backtrace(3)

   (2) https://manpages.debian.org/dladdr1(3)


File: python.info,  Node: Fault handler state,  Next: Dumping the tracebacks after a timeout,  Prev: Dumping the C stack,  Up: faulthandler — Dump the Python traceback

5.27.3.4 Fault handler state
............................

 -- Funzione: faulthandler.enable (file=sys.stderr, all_threads=True,
          c_stack=True)

     Enable the fault handler: install handlers for the *note SIGSEGV:
     1282, *note SIGFPE: 1283, *note SIGABRT: 1284, *note SIGBUS: 1285.
     and *note SIGILL: 1286. signals to dump the Python traceback.  If
     'all_threads' is ‘True’, produce tracebacks for every running
     thread.  Otherwise, dump only the current thread.

     The 'file' must be kept open until the fault handler is disabled:
     see *note issue with file descriptors: 47a0.

     If 'c_stack' is ‘True’, then the C stack trace is printed after the
     Python traceback, unless the system does not support it.  See *note
     dump_c_stack(): 20e. for more information on compatibility.

     Cambiato nella versione 3.5: Added support for passing file
     descriptor to this function.

     Cambiato nella versione 3.6: On Windows, a handler for Windows
     exception is also installed.

     Cambiato nella versione 3.10: The dump now mentions if a garbage
     collector collection is running if 'all_threads' is true.

     Cambiato nella versione 3.14: Only the current thread is dumped if
     the *note GIL: 164. is disabled to prevent the risk of data races.

     Cambiato nella versione 3.14: The dump now displays the C stack
     trace if 'c_stack' is true.

 -- Funzione: faulthandler.disable ()

     Disable the fault handler: uninstall the signal handlers installed
     by *note enable(): 20f.

 -- Funzione: faulthandler.is_enabled ()

     Check if the fault handler is enabled.


File: python.info,  Node: Dumping the tracebacks after a timeout,  Next: Dumping the traceback on a user signal,  Prev: Fault handler state,  Up: faulthandler — Dump the Python traceback

5.27.3.5 Dumping the tracebacks after a timeout
...............................................

 -- Funzione: faulthandler.dump_traceback_later (timeout, repeat=False,
          file=sys.stderr, exit=False)

     Dump the tracebacks of all threads, after a timeout of 'timeout'
     seconds, or every 'timeout' seconds if 'repeat' is ‘True’.  If
     'exit' is ‘True’, call ‘_exit()’ with status=1 after dumping the
     tracebacks.  (Note ‘_exit()’ exits the process immediately, which
     means it doesn’t do any cleanup like flushing file buffers.)  If
     the function is called twice, the new call replaces previous
     parameters and resets the timeout.  The timer has a sub-second
     resolution.

     The 'file' must be kept open until the traceback is dumped or *note
     cancel_dump_traceback_later(): 47a4. is called: see *note issue
     with file descriptors: 47a0.

     This function is implemented using a watchdog thread.

     Cambiato nella versione 3.5: Added support for passing file
     descriptor to this function.

     Cambiato nella versione 3.7: This function is now always available.

 -- Funzione: faulthandler.cancel_dump_traceback_later ()

     Cancel the last call to *note dump_traceback_later(): 1002.


File: python.info,  Node: Dumping the traceback on a user signal,  Next: Issue with file descriptors,  Prev: Dumping the tracebacks after a timeout,  Up: faulthandler — Dump the Python traceback

5.27.3.6 Dumping the traceback on a user signal
...............................................

 -- Funzione: faulthandler.register (signum, file=sys.stderr,
          all_threads=True, chain=False)

     Register a user signal: install a handler for the 'signum' signal
     to dump the traceback of all threads, or of the current thread if
     'all_threads' is ‘False’, into 'file'.  Call the previous handler
     if chain is ‘True’.

     The 'file' must be kept open until the signal is unregistered by
     *note unregister(): 47a6.: see *note issue with file descriptors:
     47a0.

     Not available on Windows.

     Cambiato nella versione 3.5: Added support for passing file
     descriptor to this function.

 -- Funzione: faulthandler.unregister (signum)

     Unregister a user signal: uninstall the handler of the 'signum'
     signal installed by *note register(): 1000.  Return ‘True’ if the
     signal was registered, ‘False’ otherwise.

     Not available on Windows.


File: python.info,  Node: Issue with file descriptors,  Next: Example<13>,  Prev: Dumping the traceback on a user signal,  Up: faulthandler — Dump the Python traceback

5.27.3.7 Issue with file descriptors
....................................

*note enable(): 20f, *note dump_traceback_later(): 1002. and *note
register(): 1000. keep the file descriptor of their 'file' argument.  If
the file is closed and its file descriptor is reused by a new file, or
if *note os.dup2(): d5c. is used to replace the file descriptor, the
traceback will be written into a different file.  Call these functions
again each time that the file is replaced.


File: python.info,  Node: Example<13>,  Prev: Issue with file descriptors,  Up: faulthandler — Dump the Python traceback

5.27.3.8 Example
................

Example of a segmentation fault on Linux with and without enabling the
fault handler:

     $ python -c "import ctypes; ctypes.string_at(0)"
     Segmentation fault

     $ python -q -X faulthandler
     >>> import ctypes
     >>> ctypes.string_at(0)
     Fatal Python error: Segmentation fault

     Current thread 0x00007fb899f39700 (most recent call first):
       File "/opt/python/Lib/ctypes/__init__.py", line 486 in string_at
       File "<stdin>", line 1 in <module>

     Current thread's C stack trace (most recent call first):
       Binary file "/opt/python/python", at _Py_DumpStack+0x42 [0x5b27f7d7147e]
       Binary file "/opt/python/python", at +0x32dcbd [0x5b27f7d85cbd]
       Binary file "/opt/python/python", at +0x32df8a [0x5b27f7d85f8a]
       Binary file "/usr/lib/libc.so.6", at +0x3def0 [0x77b73226bef0]
       Binary file "/usr/lib/libc.so.6", at +0x17ef9c [0x77b7323acf9c]
       Binary file "/opt/python/build/lib.linux-x86_64-3.14/_ctypes.cpython-314d-x86_64-linux-gnu.so", at +0xcdf6 [0x77b7315dddf6]
       Binary file "/usr/lib/libffi.so.8", at +0x7976 [0x77b73158f976]
       Binary file "/usr/lib/libffi.so.8", at +0x413c [0x77b73158c13c]
       Binary file "/usr/lib/libffi.so.8", at ffi_call+0x12e [0x77b73158ef0e]
       Binary file "/opt/python/build/lib.linux-x86_64-3.14/_ctypes.cpython-314d-x86_64-linux-gnu.so", at +0x15a33 [0x77b7315e6a33]
       Binary file "/opt/python/build/lib.linux-x86_64-3.14/_ctypes.cpython-314d-x86_64-linux-gnu.so", at +0x164fa [0x77b7315e74fa]
       Binary file "/opt/python/build/lib.linux-x86_64-3.14/_ctypes.cpython-314d-x86_64-linux-gnu.so", at +0xc624 [0x77b7315dd624]
       Binary file "/opt/python/python", at _PyObject_MakeTpCall+0xce [0x5b27f7b73883]
       Binary file "/opt/python/python", at +0x11bab6 [0x5b27f7b73ab6]
       Binary file "/opt/python/python", at PyObject_Vectorcall+0x23 [0x5b27f7b73b04]
       Binary file "/opt/python/python", at _PyEval_EvalFrameDefault+0x490c [0x5b27f7cbb302]
       Binary file "/opt/python/python", at +0x2818e6 [0x5b27f7cd98e6]
       Binary file "/opt/python/python", at +0x281aab [0x5b27f7cd9aab]
       Binary file "/opt/python/python", at PyEval_EvalCode+0xc5 [0x5b27f7cd9ba3]
       Binary file "/opt/python/python", at +0x255957 [0x5b27f7cad957]
       Binary file "/opt/python/python", at +0x255ab4 [0x5b27f7cadab4]
       Binary file "/opt/python/python", at _PyEval_EvalFrameDefault+0x6c3e [0x5b27f7cbd634]
       Binary file "/opt/python/python", at +0x2818e6 [0x5b27f7cd98e6]
       Binary file "/opt/python/python", at +0x281aab [0x5b27f7cd9aab]
       Binary file "/opt/python/python", at +0x11b6e1 [0x5b27f7b736e1]
       Binary file "/opt/python/python", at +0x11d348 [0x5b27f7b75348]
       Binary file "/opt/python/python", at +0x11d626 [0x5b27f7b75626]
       Binary file "/opt/python/python", at PyObject_Call+0x20 [0x5b27f7b7565e]
       Binary file "/opt/python/python", at +0x32a67a [0x5b27f7d8267a]
       Binary file "/opt/python/python", at +0x32a7f8 [0x5b27f7d827f8]
       Binary file "/opt/python/python", at +0x32ac1b [0x5b27f7d82c1b]
       Binary file "/opt/python/python", at Py_RunMain+0x31 [0x5b27f7d82ebe]
       <truncated rest of calls>
     Segmentation fault


File: python.info,  Node: pdb — The Python Debugger,  Next: The Python Profilers,  Prev: faulthandler — Dump the Python traceback,  Up: Debugging and Profiling

5.27.4 ‘pdb’ — The Python Debugger
----------------------------------

'Source code:' Lib/pdb.py(1)

__________________________________________________________________

The module *note pdb: aa. defines an interactive source code debugger
for Python programs.  It supports setting (conditional) breakpoints and
single stepping at the source line level, inspection of stack frames,
source code listing, and evaluation of arbitrary Python code in the
context of any stack frame.  It also supports post-mortem debugging and
can be called under program control.

The debugger is extensible – it is actually defined as the class *note
Pdb: 273.  This is currently undocumented but easily understood by
reading the source.  The extension interface uses the modules *note bdb:
10. and *note cmd: 1a.

Vedi anche
..........

Module *note faulthandler: 5c.

     Used to dump Python tracebacks explicitly, on a fault, after a
     timeout, or on a user signal.

Module *note traceback: 104.

     Standard interface to extract, format and print stack traces of
     Python programs.

The typical usage to break into the debugger is to insert:

     import pdb; pdb.set_trace()

Or:

     breakpoint()

at the location you want to break into the debugger, and then run the
program.  You can then step through the code following this statement,
and continue running without the debugger using the *note continue:
47ad. command.

Cambiato nella versione 3.7: The built-in *note breakpoint(): 271, when
called with defaults, can be used instead of ‘import pdb;
pdb.set_trace()’.

     def double(x):
        breakpoint()
        return x * 2
     val = 3
     print(f"{val} * 2 is {double(val)}")

The debugger’s prompt is ‘(Pdb)’, which is the indicator that you are in
debug mode:

     > ...(2)double()
     -> breakpoint()
     (Pdb) p x
     3
     (Pdb) continue
     3 * 2 is 6

Cambiato nella versione 3.3: Tab-completion via the *note readline: bf.
module is available for commands and command arguments, e.g.  the
current global and local names are offered as arguments of the ‘p’
command.

* Menu:

* Command-line interface: Command-line interface<8>.
* Debugger commands::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/pdb.py


File: python.info,  Node: Command-line interface<8>,  Next: Debugger commands,  Up: pdb — The Python Debugger

5.27.4.1 Command-line interface
...............................

You can also invoke *note pdb: aa. from the command line to debug other
scripts.  For example:

     python -m pdb [-c command] (-m module | -p pid | pyfile) [args ...]

When invoked as a module, pdb will automatically enter post-mortem
debugging if the program being debugged exits abnormally.  After
post-mortem debugging (or after normal exit of the program), pdb will
restart the program.  Automatic restarting preserves pdb’s state (such
as breakpoints) and in most cases is more useful than quitting the
debugger upon program’s exit.

 -- Option: -c, --command <command>

     To execute commands as if given in a ‘.pdbrc’ file; see *note
     Debugger commands: 47b1.

     Cambiato nella versione 3.2: Added the ‘-c’ option.

 -- Option: -m <module>

     To execute modules similar to the way ‘python -m’ does.  As with a
     script, the debugger will pause execution just before the first
     line of the module.

     Cambiato nella versione 3.7: Added the ‘-m’ option.

 -- Option: -p, --pid <pid>

     Attach to the process with the specified PID.

     Added in version 3.14.

To attach to a running Python process for remote debugging, use the ‘-p’
or ‘--pid’ option with the target process’s PID:

     python -m pdb -p 1234

     Nota: Attaching to a process that is blocked in a system call or
     waiting for I/O will only work once the next bytecode instruction
     is executed or when the process receives a signal.

Typical usage to execute a statement under control of the debugger is:

     >>> import pdb
     >>> def f(x):
     ...     print(1 / x)
     >>> pdb.run("f(2)")
     > <string>(1)<module>()
     (Pdb) continue
     0.5
     >>>

The typical usage to inspect a crashed program is:

     >>> import pdb
     >>> def f(x):
     ...     print(1 / x)
     ...
     >>> f(0)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
       File "<stdin>", line 2, in f
     ZeroDivisionError: division by zero
     >>> pdb.pm()
     > <stdin>(2)f()
     (Pdb) p x
     0
     (Pdb)

Cambiato nella versione 3.13: The implementation of PEP 667(1) means
that name assignments made via ‘pdb’ will immediately affect the active
scope, even when running inside an *note optimized scope: 4a2.

The module defines the following functions; each enters the debugger in
a slightly different way:

 -- Funzione: pdb.run (statement, globals=None, locals=None)

     Execute the 'statement' (given as a string or a code object) under
     debugger control.  The debugger prompt appears before any code is
     executed; you can set breakpoints and type *note continue: 47ad, or
     you can step through the statement using *note step: 47b4. or *note
     next: 47b5. (all these commands are explained below).  The optional
     'globals' and 'locals' arguments specify the environment in which
     the code is executed; by default the dictionary of the module *note
     __main__: 1. is used.  (See the explanation of the built-in *note
     exec(): 4a3. or *note eval(): 4a4. functions.)

 -- Funzione: pdb.runeval (expression, globals=None, locals=None)

     Evaluate the 'expression' (given as a string or a code object)
     under debugger control.  When *note runeval(): 47b6. returns, it
     returns the value of the 'expression'.  Otherwise this function is
     similar to *note run(): 45a3.

 -- Funzione: pdb.runcall (function, *args, **kwds)

     Call the 'function' (a function or method object, not a string)
     with the given arguments.  When *note runcall(): 47b7. returns, it
     returns whatever the function call returned.  The debugger prompt
     appears as soon as the function is entered.

 -- Funzione: pdb.set_trace (*, header=None, commands=None)

     Enter the debugger at the calling stack frame.  This is useful to
     hard-code a breakpoint at a given point in a program, even if the
     code is not otherwise being debugged (e.g.  when an assertion
     fails).  If given, 'header' is printed to the console just before
     debugging begins.  The 'commands' argument, if given, is a list of
     commands to execute when the debugger starts.

     Cambiato nella versione 3.7: The keyword-only argument 'header'.

     Cambiato nella versione 3.13: *note set_trace(): 272. will enter
     the debugger immediately, rather than on the next line of code to
     be executed.

     Added in version 3.14: The 'commands' argument.

 -- Funzione: awaitable pdb.set_trace_async (*, header=None,
          commands=None)

     async version of *note set_trace(): 272.  This function should be
     used inside an async function with *note await: 18d.

          async def f():
              await pdb.set_trace_async()

     *note await: 18d. statements are supported if the debugger is
     invoked by this function.

     Added in version 3.14.

 -- Funzione: pdb.post_mortem (t=None)

     Enter post-mortem debugging of the given exception or *note
     traceback object: cee.  If no value is given, it uses the exception
     that is currently being handled, or raises ‘ValueError’ if there
     isn’t one.

     Cambiato nella versione 3.13: Support for exception objects was
     added.

 -- Funzione: pdb.pm ()

     Enter post-mortem debugging of the exception found in *note
     sys.last_exc: 6e6.

 -- Funzione: pdb.set_default_backend (backend)

     There are two supported backends for pdb: ‘'settrace'’ and
     ‘'monitoring'’.  See *note bdb.Bdb: 2d5. for details.  The user can
     set the default backend to use if none is specified when
     instantiating *note Pdb: 273.  If no backend is specified, the
     default is ‘'settrace'’.

          Nota: *note breakpoint(): 271. and *note set_trace(): 272.
          will not be affected by this function.  They always use
          ‘'monitoring'’ backend.

     Added in version 3.14.

 -- Funzione: pdb.get_default_backend ()

     Returns the default backend for pdb.

     Added in version 3.14.

The ‘run*’ functions and *note set_trace(): 272. are aliases for
instantiating the *note Pdb: 273. class and calling the method of the
same name.  If you want to access further features, you have to do this
yourself:

 -- Classe: pdb.Pdb (completekey='tab', stdin=None, stdout=None,
          skip=None, nosigint=False, readrc=True, mode=None,
          backend=None, colorize=False)

     *note Pdb: 273. is the debugger class.

     The 'completekey', 'stdin' and 'stdout' arguments are passed to the
     underlying *note cmd.Cmd: 1836. class; see the description there.

     The 'skip' argument, if given, must be an iterable of glob-style
     module name patterns.  The debugger will not step into frames that
     originate in a module that matches one of these patterns.  (2)

     By default, Pdb sets a handler for the SIGINT signal (which is sent
     when the user presses ‘Ctrl’-‘C’ on the console) when you give a
     *note continue: 47ad. command.  This allows you to break into the
     debugger again by pressing ‘Ctrl’-‘C’.  If you want Pdb not to
     touch the SIGINT handler, set 'nosigint' to true.

     The 'readrc' argument defaults to true and controls whether Pdb
     will load .pdbrc files from the filesystem.

     The 'mode' argument specifies how the debugger was invoked.  It
     impacts the workings of some debugger commands.  Valid values are
     ‘'inline'’ (used by the breakpoint() builtin), ‘'cli'’ (used by the
     command line invocation) or ‘None’ (for backwards compatible
     behaviour, as before the 'mode' argument was added).

     The 'backend' argument specifies the backend to use for the
     debugger.  If ‘None’ is passed, the default backend will be used.
     See *note set_default_backend(): 47b8.  Otherwise the supported
     backends are ‘'settrace'’ and ‘'monitoring'’.

     The 'colorize' argument, if set to ‘True’, will enable colorized
     output in the debugger, if color is supported.  This will highlight
     source code displayed in pdb.

     Example call to enable tracing with 'skip':

          import pdb; pdb.Pdb(skip=['django.*']).set_trace()

     Raises an *note auditing event: 1c56. ‘pdb.Pdb’ with no arguments.

     Cambiato nella versione 3.1: Added the 'skip' parameter.

     Cambiato nella versione 3.2: Added the 'nosigint' parameter.
     Previously, a SIGINT handler was never set by Pdb.

     Cambiato nella versione 3.6: The 'readrc' argument.

     Added in version 3.14: Added the 'mode' argument.

     Added in version 3.14: Added the 'backend' argument.

     Added in version 3.14: Added the 'colorize' argument.

     Cambiato nella versione 3.14: Inline breakpoints like *note
     breakpoint(): 271. or *note pdb.set_trace(): 272. will always stop
     the program at calling frame, ignoring the 'skip' pattern (if any).

      -- Metodo: run (statement, globals=None, locals=None)
      -- Metodo: runeval (expression, globals=None, locals=None)
      -- Metodo: runcall (function, *args, **kwds)
      -- Metodo: set_trace ()

          See the documentation for the functions explained above.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0667/

   (2) Whether a frame is considered to originate in a certain module is
determined by the ‘__name__’ in the frame globals.


File: python.info,  Node: Debugger commands,  Prev: Command-line interface<8>,  Up: pdb — The Python Debugger

5.27.4.2 Debugger commands
..........................

The commands recognized by the debugger are listed below.  Most commands
can be abbreviated to one or two letters as indicated; e.g.  ‘h(elp)’
means that either ‘h’ or ‘help’ can be used to enter the help command
(but not ‘he’ or ‘hel’, nor ‘H’ or ‘Help’ or ‘HELP’).  Arguments to
commands must be separated by whitespace (spaces or tabs).  Optional
arguments are enclosed in square brackets (‘[]’) in the command syntax;
the square brackets must not be typed.  Alternatives in the command
syntax are separated by a vertical bar (‘|’).

Entering a blank line repeats the last command entered.  Exception: if
the last command was a *note list: 47be. command, the next 11 lines are
listed.

Commands that the debugger doesn’t recognize are assumed to be Python
statements and are executed in the context of the program being
debugged.  Python statements can also be prefixed with an exclamation
point (‘!’).  This is a powerful way to inspect the program being
debugged; it is even possible to change a variable or call a function.
When an exception occurs in such a statement, the exception name is
printed but the debugger’s state is not changed.

Cambiato nella versione 3.13: Expressions/Statements whose prefix is a
pdb command are now correctly identified and executed.

The debugger supports *note aliases: 47bf.  Aliases can have parameters
which allows one a certain level of adaptability to the context under
examination.

Multiple commands may be entered on a single line, separated by ‘;;’.
(A single ‘;’ is not used as it is the separator for multiple commands
in a line that is passed to the Python parser.)  No intelligence is
applied to separating the commands; the input is split at the first ‘;;’
pair, even if it is in the middle of a quoted string.  A workaround for
strings with double semicolons is to use implicit string concatenation
‘';'';'’ or ‘";"";"’.

To set a temporary global variable, use a 'convenience variable'.  A
'convenience variable' is a variable whose name starts with ‘$’.  For
example, ‘$foo = 1’ sets a global variable ‘$foo’ which you can use in
the debugger session.  The 'convenience variables' are cleared when the
program resumes execution so it’s less likely to interfere with your
program compared to using normal variables like ‘foo = 1’.

There are four preset 'convenience variables':

   * ‘$_frame’: the current frame you are debugging

   * ‘$_retval’: the return value if the frame is returning

   * ‘$_exception’: the exception if the frame is raising an exception

   * ‘$_asynctask’: the asyncio task if pdb stops in an async function

Added in version 3.12: Added the 'convenience variable' feature.

Added in version 3.14: Added the ‘$_asynctask’ convenience variable.

If a file ‘.pdbrc’ exists in the user’s home directory or in the current
directory, it is read with ‘'utf-8'’ encoding and executed as if it had
been typed at the debugger prompt, with the exception that empty lines
and lines starting with ‘#’ are ignored.  This is particularly useful
for aliases.  If both files exist, the one in the home directory is read
first and aliases defined there can be overridden by the local file.

Cambiato nella versione 3.2: ‘.pdbrc’ can now contain commands that
continue debugging, such as *note continue: 47ad. or *note next: 47b5.
Previously, these commands had no effect.

Cambiato nella versione 3.11: ‘.pdbrc’ is now read with ‘'utf-8'’
encoding.  Previously, it was read with the system locale encoding.

 -- Pdbcommand: h(elp) [command]

     Without argument, print the list of available commands.  With a
     'command' as argument, print help about that command.  ‘help pdb’
     displays the full documentation (the docstring of the *note pdb:
     aa. module).  Since the 'command' argument must be an identifier,
     ‘help exec’ must be entered to get help on the ‘!’ command.

 -- Pdbcommand: w(here) [count]

     Print a stack trace, with the most recent frame at the bottom.  if
     'count' is 0, print the current frame entry.  If 'count' is
     negative, print the least recent - 'count' frames.  If 'count' is
     positive, print the most recent 'count' frames.  An arrow (‘>’)
     indicates the current frame, which determines the context of most
     commands.

     Cambiato nella versione 3.14: 'count' argument is added.

 -- Pdbcommand: d(own) [count]

     Move the current frame 'count' (default one) levels down in the
     stack trace (to a newer frame).

 -- Pdbcommand: u(p) [count]

     Move the current frame 'count' (default one) levels up in the stack
     trace (to an older frame).

 -- Pdbcommand: b(reak) [([filename:]lineno | function) [, condition]]

     With a 'lineno' argument, set a break at line 'lineno' in the
     current file.  The line number may be prefixed with a 'filename'
     and a colon, to specify a breakpoint in another file (possibly one
     that hasn’t been loaded yet).  The file is searched on *note
     sys.path: 3e4.  Acceptable forms of 'filename' are
     ‘/abspath/to/file.py’, ‘relpath/file.py’, ‘module’ and
     ‘package.module’.

     With a 'function' argument, set a break at the first executable
     statement within that function.  'function' can be any expression
     that evaluates to a function in the current namespace.

     If a second argument is present, it is an expression which must
     evaluate to true before the breakpoint is honored.

     Without argument, list all breaks, including for each breakpoint,
     the number of times that breakpoint has been hit, the current
     ignore count, and the associated condition if any.

     Each breakpoint is assigned a number to which all the other
     breakpoint commands refer.

 -- Pdbcommand: tbreak [([filename:]lineno | function) [, condition]]

     Temporary breakpoint, which is removed automatically when it is
     first hit.  The arguments are the same as for *note break: 47c4.

 -- Pdbcommand: cl(ear) [filename:lineno | bpnumber ...]

     With a 'filename:lineno' argument, clear all the breakpoints at
     this line.  With a space separated list of breakpoint numbers,
     clear those breakpoints.  Without argument, clear all breaks (but
     first ask confirmation).

 -- Pdbcommand: disable bpnumber [bpnumber ...]

     Disable the breakpoints given as a space separated list of
     breakpoint numbers.  Disabling a breakpoint means it cannot cause
     the program to stop execution, but unlike clearing a breakpoint, it
     remains in the list of breakpoints and can be (re-)enabled.

 -- Pdbcommand: enable bpnumber [bpnumber ...]

     Enable the breakpoints specified.

 -- Pdbcommand: ignore bpnumber [count]

     Set the ignore count for the given breakpoint number.  If 'count'
     is omitted, the ignore count is set to 0.  A breakpoint becomes
     active when the ignore count is zero.  When non-zero, the 'count'
     is decremented each time the breakpoint is reached and the
     breakpoint is not disabled and any associated condition evaluates
     to true.

 -- Pdbcommand: condition bpnumber [condition]

     Set a new 'condition' for the breakpoint, an expression which must
     evaluate to true before the breakpoint is honored.  If 'condition'
     is absent, any existing condition is removed; i.e., the breakpoint
     is made unconditional.

 -- Pdbcommand: commands [bpnumber]

     Specify a list of commands for breakpoint number 'bpnumber'.  The
     commands themselves appear on the following lines.  Type a line
     containing just ‘end’ to terminate the commands.  An example:

          (Pdb) commands 1
          (com) p some_variable
          (com) end
          (Pdb)

     To remove all commands from a breakpoint, type ‘commands’ and
     follow it immediately with ‘end’; that is, give no commands.

     With no 'bpnumber' argument, ‘commands’ refers to the last
     breakpoint set.

     You can use breakpoint commands to start your program up again.
     Simply use the *note continue: 47ad. command, or *note step: 47b4,
     or any other command that resumes execution.

     Specifying any command resuming execution (currently *note
     continue: 47ad, *note step: 47b4, *note next: 47b5, *note return:
     47cb, *note until: 47cc, *note jump: 47cd, *note quit: 47ce. and
     their abbreviations) terminates the command list (as if that
     command was immediately followed by end).  This is because any time
     you resume execution (even with a simple next or step), you may
     encounter another breakpoint—which could have its own command list,
     leading to ambiguities about which list to execute.

     If the list of commands contains the ‘silent’ command, or a command
     that resumes execution, then the breakpoint message containing
     information about the frame is not displayed.

     Cambiato nella versione 3.14: Frame information will not be
     displayed if a command that resumes execution is present in the
     command list.

 -- Pdbcommand: s(tep)

     Execute the current line, stop at the first possible occasion
     (either in a function that is called or on the next line in the
     current function).

 -- Pdbcommand: n(ext)

     Continue execution until the next line in the current function is
     reached or it returns.  (The difference between *note next: 47b5.
     and *note step: 47b4. is that *note step: 47b4. stops inside a
     called function, while *note next: 47b5. executes called functions
     at (nearly) full speed, only stopping at the next line in the
     current function.)

 -- Pdbcommand: unt(il) [lineno]

     Without argument, continue execution until the line with a number
     greater than the current one is reached.

     With 'lineno', continue execution until a line with a number
     greater or equal to 'lineno' is reached.  In both cases, also stop
     when the current frame returns.

     Cambiato nella versione 3.2: Allow giving an explicit line number.

 -- Pdbcommand: r(eturn)

     Continue execution until the current function returns.

 -- Pdbcommand: c(ont(inue))

     Continue execution, only stop when a breakpoint is encountered.

 -- Pdbcommand: j(ump) lineno

     Set the next line that will be executed.  Only available in the
     bottom-most frame.  This lets you jump back and execute code again,
     or jump forward to skip code that you don’t want to run.

     It should be noted that not all jumps are allowed – for instance it
     is not possible to jump into the middle of a *note for: 34a. loop
     or out of a *note finally: 1b0. clause.

 -- Pdbcommand: l(ist) [first[, last]]

     List source code for the current file.  Without arguments, list 11
     lines around the current line or continue the previous listing.
     With ‘.’ as argument, list 11 lines around the current line.  With
     one argument, list 11 lines around at that line.  With two
     arguments, list the given range; if the second argument is less
     than the first, it is interpreted as a count.

     The current line in the current frame is indicated by ‘->’.  If an
     exception is being debugged, the line where the exception was
     originally raised or propagated is indicated by ‘>>’, if it differs
     from the current line.

     Cambiato nella versione 3.2: Added the ‘>>’ marker.

 -- Pdbcommand: ll | longlist

     List all source code for the current function or frame.
     Interesting lines are marked as for *note list: 47be.

     Added in version 3.2.

 -- Pdbcommand: a(rgs)

     Print the arguments of the current function and their current
     values.

 -- Pdbcommand: p expression

     Evaluate 'expression' in the current context and print its value.

          Nota: ‘print()’ can also be used, but is not a debugger
          command — this executes the Python *note print(): 1177.
          function.

 -- Pdbcommand: pp expression

     Like the *note p: 1178. command, except the value of 'expression'
     is pretty-printed using the *note pprint: b3. module.

 -- Pdbcommand: whatis expression

     Print the type of 'expression'.

 -- Pdbcommand: source expression

     Try to get source code of 'expression' and display it.

     Added in version 3.2.

 -- Pdbcommand: display [expression]

     Display the value of 'expression' if it changed, each time
     execution stops in the current frame.

     Without 'expression', list all display expressions for the current
     frame.

          Nota: Display evaluates 'expression' and compares to the
          result of the previous evaluation of 'expression', so when the
          result is mutable, display may not be able to pick up the
          changes.

     Example:

          lst = []
          breakpoint()
          pass
          lst.append(1)
          print(lst)

     Display won’t realize ‘lst’ has been changed because the result of
     evaluation is modified in place by ‘lst.append(1)’ before being
     compared:

          > example.py(3)<module>()
          -> pass
          (Pdb) display lst
          display lst: []
          (Pdb) n
          > example.py(4)<module>()
          -> lst.append(1)
          (Pdb) n
          > example.py(5)<module>()
          -> print(lst)
          (Pdb)

     You can do some tricks with copy mechanism to make it work:

          > example.py(3)<module>()
          -> pass
          (Pdb) display lst[:]
          display lst[:]: []
          (Pdb) n
          > example.py(4)<module>()
          -> lst.append(1)
          (Pdb) n
          > example.py(5)<module>()
          -> print(lst)
          display lst[:]: [1]  [old: []]
          (Pdb)

     Added in version 3.2.

 -- Pdbcommand: undisplay [expression]

     Do not display 'expression' anymore in the current frame.  Without
     'expression', clear all display expressions for the current frame.

     Added in version 3.2.

 -- Pdbcommand: interact

     Start an interactive interpreter (using the *note code: 1b. module)
     in a new global namespace initialised from the local and global
     namespaces for the current scope.  Use ‘exit()’ or ‘quit()’ to exit
     the interpreter and return to the debugger.

          Nota: As ‘interact’ creates a new dedicated namespace for code
          execution, assignments to variables will not affect the
          original namespaces.  However, modifications to any referenced
          mutable objects will be reflected in the original namespaces
          as usual.

     Added in version 3.2.

     Cambiato nella versione 3.13: ‘exit()’ and ‘quit()’ can be used to
     exit the *note interact: 47d5. command.

     Cambiato nella versione 3.13: *note interact: 47d5. directs its
     output to the debugger’s output channel rather than *note
     sys.stderr: b35.

 -- Pdbcommand: alias [name [command]]

     Create an alias called 'name' that executes 'command'.  The
     'command' must 'not' be enclosed in quotes.  Replaceable parameters
     can be indicated by ‘%1’, ‘%2’, … and ‘%9’, while ‘%*’ is replaced
     by all the parameters.  If 'command' is omitted, the current alias
     for 'name' is shown.  If no arguments are given, all aliases are
     listed.

     Aliases may be nested and can contain anything that can be legally
     typed at the pdb prompt.  Note that internal pdb commands 'can' be
     overridden by aliases.  Such a command is then hidden until the
     alias is removed.  Aliasing is recursively applied to the first
     word of the command line; all other words in the line are left
     alone.

     As an example, here are two useful aliases (especially when placed
     in the ‘.pdbrc’ file):

          # Print instance variables (usage "pi classInst")
          alias pi for k in %1.__dict__.keys(): print(f"%1.{k} = {%1.__dict__[k]}")
          # Print instance variables in self
          alias ps pi self

 -- Pdbcommand: unalias name

     Delete the specified alias 'name'.

 -- Pdbcommand: ! statement

     Execute the (one-line) 'statement' in the context of the current
     stack frame.  The exclamation point can be omitted unless the first
     word of the statement resembles a debugger command, e.g.:

          (Pdb) ! n=42
          (Pdb)

     To set a global variable, you can prefix the assignment command
     with a *note global: 4ad. statement on the same line, e.g.:

          (Pdb) global list_options; list_options = ['-l']
          (Pdb)

 -- Pdbcommand: run [args ...]
 -- Pdbcommand: restart [args ...]

     Restart the debugged Python program.  If 'args' is supplied, it is
     split with *note shlex: c9. and the result is used as the new *note
     sys.argv: 146c.  History, breakpoints, actions and debugger options
     are preserved.  *note restart: 47da. is an alias for *note run:
     47d9.

     Cambiato nella versione 3.14: *note run: 47d9. and *note restart:
     47da. commands are disabled when the debugger is invoked in
     ‘'inline'’ mode.

 -- Pdbcommand: q(uit)

     Quit from the debugger.  The program being executed is aborted.  An
     end-of-file input is equivalent to *note quit: 47ce.

     A confirmation prompt will be shown if the debugger is invoked in
     ‘'inline'’ mode.  Either ‘y’, ‘Y’, ‘<Enter>’ or ‘EOF’ will confirm
     the quit.

     Cambiato nella versione 3.14: A confirmation prompt will be shown
     if the debugger is invoked in ‘'inline'’ mode.  After the
     confirmation, the debugger will call *note sys.exit(): 277.
     immediately, instead of raising *note bdb.BdbQuit: 278. in the next
     trace event.

 -- Pdbcommand: debug code

     Enter a recursive debugger that steps through 'code' (which is an
     arbitrary expression or statement to be executed in the current
     environment).

 -- Pdbcommand: retval

     Print the return value for the last return of the current function.

 -- Pdbcommand: exceptions [excnumber]

     List or jump between chained exceptions.

     When using ‘pdb.pm()’ or ‘Pdb.post_mortem(...)’ with a chained
     exception instead of a traceback, it allows the user to move
     between the chained exceptions using ‘exceptions’ command to list
     exceptions, and ‘exceptions <number>’ to switch to that exception.

     Example:

          def out():
              try:
                  middle()
              except Exception as e:
                  raise ValueError("reraise middle() error") from e

          def middle():
              try:
                  return inner(0)
              except Exception as e:
                  raise ValueError("Middle fail")

          def inner(x):
              1 / x

           out()

     calling ‘pdb.pm()’ will allow to move between exceptions:

          > example.py(5)out()
          -> raise ValueError("reraise middle() error") from e

          (Pdb) exceptions
            0 ZeroDivisionError('division by zero')
            1 ValueError('Middle fail')
          > 2 ValueError('reraise middle() error')

          (Pdb) exceptions 0
          > example.py(16)inner()
          -> 1 / x

          (Pdb) up
          > example.py(10)middle()
          -> return inner(0)

     Added in version 3.13.


File: python.info,  Node: The Python Profilers,  Next: timeit — Measure execution time of small code snippets,  Prev: pdb — The Python Debugger,  Up: Debugging and Profiling

5.27.5 The Python Profilers
---------------------------

'Source code:' Lib/profile.py(1) and Lib/pstats.py(2)

__________________________________________________________________

* Menu:

* Introduction to the profilers::
* Instant User’s Manual::
* profile and cProfile Module Reference::
* The Stats Class::
* What Is Deterministic Profiling?::
* Limitations::
* Calibration::
* Using a custom timer::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/profile.py

   (2) https://github.com/python/cpython/tree/3.14/Lib/pstats.py


File: python.info,  Node: Introduction to the profilers,  Next: Instant User’s Manual,  Up: The Python Profilers

5.27.5.1 Introduction to the profilers
......................................

*note cProfile: 2b. and *note profile: b4. provide 'deterministic
profiling' of Python programs.  A 'profile' is a set of statistics that
describes how often and for how long various parts of the program
executed.  These statistics can be formatted into reports via the *note
pstats: b5. module.

The Python standard library provides two different implementations of
the same profiling interface:

  1. *note cProfile: 2b. is recommended for most users; it’s a C
     extension with reasonable overhead that makes it suitable for
     profiling long-running programs.  Based on ‘lsprof’, contributed by
     Brett Rosen and Ted Czotter.

  2. *note profile: b4, a pure Python module whose interface is imitated
     by *note cProfile: 2b, but which adds significant overhead to
     profiled programs.  If you’re trying to extend the profiler in some
     way, the task might be easier with this module.  Originally
     designed and written by Jim Roskind.

     Nota: The profiler modules are designed to provide an execution
     profile for a given program, not for benchmarking purposes (for
     that, there is *note timeit: f5. for reasonably accurate results).
     This particularly applies to benchmarking Python code against C
     code: the profilers introduce overhead for Python code, but not for
     C-level functions, and so the C code would seem faster than any
     Python one.


File: python.info,  Node: Instant User’s Manual,  Next: profile and cProfile Module Reference,  Prev: Introduction to the profilers,  Up: The Python Profilers

5.27.5.2 Instant User’s Manual
..............................

This section is provided for users that «don’t want to read the manual.»
It provides a very brief overview, and allows a user to rapidly perform
profiling on an existing application.

To profile a function that takes a single argument, you can do:

     import cProfile
     import re
     cProfile.run('re.compile("foo|bar")')

(Use *note profile: b4. instead of *note cProfile: 2b. if the latter is
not available on your system.)

The above action would run *note re.compile(): dd0. and print profile
results like the following:

           214 function calls (207 primitive calls) in 0.002 seconds

     Ordered by: cumulative time

     ncalls  tottime  percall  cumtime  percall filename:lineno(function)
          1    0.000    0.000    0.002    0.002 {built-in method builtins.exec}
          1    0.000    0.000    0.001    0.001 <string>:1(<module>)
          1    0.000    0.000    0.001    0.001 __init__.py:250(compile)
          1    0.000    0.000    0.001    0.001 __init__.py:289(_compile)
          1    0.000    0.000    0.000    0.000 _compiler.py:759(compile)
          1    0.000    0.000    0.000    0.000 _parser.py:937(parse)
          1    0.000    0.000    0.000    0.000 _compiler.py:598(_code)
          1    0.000    0.000    0.000    0.000 _parser.py:435(_parse_sub)

The first line indicates that 214 calls were monitored.  Of those calls,
207 were 'primitive', meaning that the call was not induced via
recursion.  The next line: ‘Ordered by: cumulative time’ indicates the
output is sorted by the ‘cumtime’ values.  The column headings include:

ncalls

     for the number of calls.

tottime

     for the total time spent in the given function (and excluding time
     made in calls to sub-functions)

percall

     is the quotient of ‘tottime’ divided by ‘ncalls’

cumtime

     is the cumulative time spent in this and all subfunctions (from
     invocation till exit).  This figure is accurate 'even' for
     recursive functions.

percall

     is the quotient of ‘cumtime’ divided by primitive calls

filename:lineno(function)

     provides the respective data of each function

When there are two numbers in the first column (for example ‘3/1’), it
means that the function recursed.  The second value is the number of
primitive calls and the former is the total number of calls.  Note that
when the function does not recurse, these two values are the same, and
only the single figure is printed.

Instead of printing the output at the end of the profile run, you can
save the results to a file by specifying a filename to the ‘run()’
function:

     import cProfile
     import re
     cProfile.run('re.compile("foo|bar")', 'restats')

The *note pstats.Stats: 47e5. class reads profile results from a file
and formats them in various ways.  The files *note cProfile: 2b. and
*note profile: b4. can also be invoked as a script to profile another
script.  For example:

     python -m cProfile [-o output_file] [-s sort_order] (-m module | myscript.py)

 -- Option: -o <output_file>

     Writes the profile results to a file instead of to stdout.

 -- Option: -s <sort_order>

     Specifies one of the *note sort_stats(): 47e9. sort values to sort
     the output by.  This only applies when *note -o: 47e7. is not
     supplied.

 -- Option: -m <module>

     Specifies that a module is being profiled instead of a script.

     Added in version 3.7: Added the ‘-m’ option to *note cProfile: 2b.

     Added in version 3.8: Added the ‘-m’ option to *note profile: b4.

The *note pstats: b5. module’s *note Stats: 47e5. class has a variety of
methods for manipulating and printing the data saved into a profile
results file:

     import pstats
     from pstats import SortKey
     p = pstats.Stats('restats')
     p.strip_dirs().sort_stats(-1).print_stats()

The *note strip_dirs(): 47eb. method removed the extraneous path from
all the module names.  The *note sort_stats(): 47e9. method sorted all
the entries according to the standard module/line/name string that is
printed.  The *note print_stats(): 47ec. method printed out all the
statistics.  You might try the following sort calls:

     p.sort_stats(SortKey.NAME)
     p.print_stats()

The first call will actually sort the list by function name, and the
second call will print out the statistics.  The following are some
interesting calls to experiment with:

     p.sort_stats(SortKey.CUMULATIVE).print_stats(10)

This sorts the profile by cumulative time in a function, and then only
prints the ten most significant lines.  If you want to understand what
algorithms are taking time, the above line is what you would use.

If you were looking to see what functions were looping a lot, and taking
a lot of time, you would do:

     p.sort_stats(SortKey.TIME).print_stats(10)

to sort according to time spent within each function, and then print the
statistics for the top ten functions.

You might also try:

     p.sort_stats(SortKey.FILENAME).print_stats('__init__')

This will sort all the statistics by file name, and then print out
statistics for only the class init methods (since they are spelled with
‘__init__’ in them).  As one final example, you could try:

     p.sort_stats(SortKey.TIME, SortKey.CUMULATIVE).print_stats(.5, 'init')

This line sorts statistics with a primary key of time, and a secondary
key of cumulative time, and then prints out some of the statistics.  To
be specific, the list is first culled down to 50% (re: ‘.5’) of its
original size, then only lines containing ‘init’ are maintained, and
that sub-sub-list is printed.

If you wondered what functions called the above functions, you could now
(‘p’ is still sorted according to the last criteria) do:

     p.print_callers(.5, 'init')

and you would get a list of callers for each of the listed functions.

If you want more functionality, you’re going to have to read the manual,
or guess what the following functions do:

     p.print_callees()
     p.add('restats')

Invoked as a script, the *note pstats: b5. module is a statistics
browser for reading and examining profile dumps.  It has a simple
line-oriented interface (implemented using *note cmd: 1a.) and
interactive help.


File: python.info,  Node: profile and cProfile Module Reference,  Next: The Stats Class,  Prev: Instant User’s Manual,  Up: The Python Profilers

5.27.5.3 ‘profile’ and ‘cProfile’ Module Reference
..................................................

Both the *note profile: b4. and *note cProfile: 2b. modules provide the
following functions:

 -- Funzione: profile.run (command, filename=None, sort=-1)

     This function takes a single argument that can be passed to the
     *note exec(): 4a3. function, and an optional file name.  In all
     cases this routine executes:

          exec(command, __main__.__dict__, __main__.__dict__)

     and gathers profiling statistics from the execution.  If no file
     name is present, then this function automatically creates a *note
     Stats: 47e5. instance and prints a simple profiling report.  If the
     sort value is specified, it is passed to this *note Stats: 47e5.
     instance to control how the results are sorted.

 -- Funzione: profile.runctx (command, globals, locals, filename=None,
          sort=-1)

     This function is similar to *note run(): 47ee, with added arguments
     to supply the globals and locals mappings for the 'command' string.
     This routine executes:

          exec(command, globals, locals)

     and gathers profiling statistics as in the *note run(): 47ee.
     function above.

 -- Classe: profile.Profile (timer=None, timeunit=0.0, subcalls=True,
          builtins=True)

     This class is normally only used if more precise control over
     profiling is needed than what the ‘cProfile.run()’ function
     provides.

     A custom timer can be supplied for measuring how long code takes to
     run via the 'timer' argument.  This must be a function that returns
     a single number representing the current time.  If the number is an
     integer, the 'timeunit' specifies a multiplier that specifies the
     duration of each unit of time.  For example, if the timer returns
     times measured in thousands of seconds, the time unit would be
     ‘.001’.

     Directly using the *note Profile: bd8. class allows formatting
     profile results without writing the profile data to a file:

          import cProfile, pstats, io
          from pstats import SortKey
          pr = cProfile.Profile()
          pr.enable()
          # ... do something ...
          pr.disable()
          s = io.StringIO()
          sortby = SortKey.CUMULATIVE
          ps = pstats.Stats(pr, stream=s).sort_stats(sortby)
          ps.print_stats()
          print(s.getvalue())

     The *note Profile: bd8. class can also be used as a context manager
     (supported only in *note cProfile: 2b. module.  see *note Tipi di
     gestori di contesti: 23f0.):

          import cProfile

          with cProfile.Profile() as pr:
              # ... do something ...

              pr.print_stats()

     Cambiato nella versione 3.8: Added context manager support.

      -- Metodo: enable ()

          Start collecting profiling data.  Only in *note cProfile: 2b.

      -- Metodo: disable ()

          Stop collecting profiling data.  Only in *note cProfile: 2b.

      -- Metodo: create_stats ()

          Stop collecting profiling data and record the results
          internally as the current profile.

      -- Metodo: print_stats (sort=-1)

          Create a *note Stats: 47e5. object based on the current
          profile and print the results to stdout.

          The 'sort' parameter specifies the sorting order of the
          displayed statistics.  It accepts a single key or a tuple of
          keys to enable multi-level sorting, as in *note
          Stats.sort_stats: 47e9.

          Added in version 3.13: *note print_stats(): 47f3. now accepts
          a tuple of keys.

      -- Metodo: dump_stats (filename)

          Write the results of the current profile to 'filename'.

      -- Metodo: run (cmd)

          Profile the cmd via *note exec(): 4a3.

      -- Metodo: runctx (cmd, globals, locals)

          Profile the cmd via *note exec(): 4a3. with the specified
          global and local environment.

      -- Metodo: runcall (func, /, *args, **kwargs)

          Profile ‘func(*args, **kwargs)’

Note that profiling will only work if the called command/function
actually returns.  If the interpreter is terminated (e.g.  via a *note
sys.exit(): 277. call during the called command/function execution) no
profiling results will be printed.


File: python.info,  Node: The Stats Class,  Next: What Is Deterministic Profiling?,  Prev: profile and cProfile Module Reference,  Up: The Python Profilers

5.27.5.4 The ‘Stats’ Class
..........................

Analysis of the profiler data is done using the *note Stats: 47e5.
class.

 -- Classe: pstats.Stats (*filenames or profile, stream=sys.stdout)

     This class constructor creates an instance of a «statistics object»
     from a 'filename' (or list of filenames) or from a ‘Profile’
     instance.  Output will be printed to the stream specified by
     'stream'.

     The file selected by the above constructor must have been created
     by the corresponding version of *note profile: b4. or *note
     cProfile: 2b.  To be specific, there is 'no' file compatibility
     guaranteed with future versions of this profiler, and there is no
     compatibility with files produced by other profilers, or the same
     profiler run on a different operating system.  If several files are
     provided, all the statistics for identical functions will be
     coalesced, so that an overall view of several processes can be
     considered in a single report.  If additional files need to be
     combined with data in an existing *note Stats: 47e5. object, the
     *note add(): 47f9. method can be used.

     Instead of reading the profile data from a file, a
     ‘cProfile.Profile’ or *note profile.Profile: bd8. object can be
     used as the profile data source.

     *note Stats: 47e5. objects have the following methods:

      -- Metodo: strip_dirs ()

          This method for the *note Stats: 47e5. class removes all
          leading path information from file names.  It is very useful
          in reducing the size of the printout to fit within (close to)
          80 columns.  This method modifies the object, and the stripped
          information is lost.  After performing a strip operation, the
          object is considered to have its entries in a «random» order,
          as it was just after object initialization and loading.  If
          *note strip_dirs(): 47eb. causes two function names to be
          indistinguishable (they are on the same line of the same
          filename, and have the same function name), then the
          statistics for these two entries are accumulated into a single
          entry.

      -- Metodo: add (*filenames)

          This method of the *note Stats: 47e5. class accumulates
          additional profiling information into the current profiling
          object.  Its arguments should refer to filenames created by
          the corresponding version of *note profile.run(): 47ee. or
          ‘cProfile.run()’.  Statistics for identically named (re: file,
          line, name) functions are automatically accumulated into
          single function statistics.

      -- Metodo: dump_stats (filename)

          Save the data loaded into the *note Stats: 47e5. object to a
          file named 'filename'.  The file is created if it does not
          exist, and is overwritten if it already exists.  This is
          equivalent to the method of the same name on the *note
          profile.Profile: bd8. and ‘cProfile.Profile’ classes.

      -- Metodo: sort_stats (*keys)

          This method modifies the *note Stats: 47e5. object by sorting
          it according to the supplied criteria.  The argument can be
          either a string or a SortKey enum identifying the basis of a
          sort (example: ‘'time'’, ‘'name'’, ‘SortKey.TIME’ or
          ‘SortKey.NAME’).  The SortKey enums argument have advantage
          over the string argument in that it is more robust and less
          error prone.

          When more than one key is provided, then additional keys are
          used as secondary criteria when there is equality in all keys
          selected before them.  For example, ‘sort_stats(SortKey.NAME,
          SortKey.FILE)’ will sort all the entries according to their
          function name, and resolve all ties (identical function names)
          by sorting by file name.

          For the string argument, abbreviations can be used for any key
          names, as long as the abbreviation is unambiguous.

          The following are the valid string and SortKey:

          Valid String Arg       Valid enum Arg            Meaning
                                                           
          ----------------------------------------------------------------------------
                                                           
          ‘'calls'’              SortKey.CALLS             call count
                                                           
                                                           
          ‘'cumulative'’         SortKey.CUMULATIVE        cumulative time
                                                           
                                                           
          ‘'cumtime'’            N/A                       cumulative time
                                                           
                                                           
          ‘'file'’               N/A                       file name
                                                           
                                                           
          ‘'filename'’           SortKey.FILENAME          file name
                                                           
                                                           
          ‘'module'’             N/A                       file name
                                                           
                                                           
          ‘'ncalls'’             N/A                       call count
                                                           
                                                           
          ‘'pcalls'’             SortKey.PCALLS            primitive call count
                                                           
                                                           
          ‘'line'’               SortKey.LINE              line number
                                                           
                                                           
          ‘'name'’               SortKey.NAME              function name
                                                           
                                                           
          ‘'nfl'’                SortKey.NFL               name/file/line
                                                           
                                                           
          ‘'stdname'’            SortKey.STDNAME           standard name
                                                           
                                                           
          ‘'time'’               SortKey.TIME              internal time
                                                           
                                                           
          ‘'tottime'’            N/A                       internal time
                                                           

          Note that all sorts on statistics are in descending order
          (placing most time consuming items first), where as name,
          file, and line number searches are in ascending order
          (alphabetical).  The subtle distinction between ‘SortKey.NFL’
          and ‘SortKey.STDNAME’ is that the standard name is a sort of
          the name as printed, which means that the embedded line
          numbers get compared in an odd way.  For example, lines 3, 20,
          and 40 would (if the file names were the same) appear in the
          string order 20, 3 and 40.  In contrast, ‘SortKey.NFL’ does a
          numeric compare of the line numbers.  In fact,
          ‘sort_stats(SortKey.NFL)’ is the same as
          ‘sort_stats(SortKey.NAME, SortKey.FILENAME, SortKey.LINE)’.

          For backward-compatibility reasons, the numeric arguments
          ‘-1’, ‘0’, ‘1’, and ‘2’ are permitted.  They are interpreted
          as ‘'stdname'’, ‘'calls'’, ‘'time'’, and ‘'cumulative'’
          respectively.  If this old style format (numeric) is used,
          only one sort key (the numeric key) will be used, and
          additional arguments will be silently ignored.

          Added in version 3.7: Added the SortKey enum.

      -- Metodo: reverse_order ()

          This method for the *note Stats: 47e5. class reverses the
          ordering of the basic list within the object.  Note that by
          default ascending vs descending order is properly selected
          based on the sort key of choice.

      -- Metodo: print_stats (*restrictions)

          This method for the *note Stats: 47e5. class prints out a
          report as described in the *note profile.run(): 47ee.
          definition.

          The order of the printing is based on the last *note
          sort_stats(): 47e9. operation done on the object (subject to
          caveats in *note add(): 47f9. and *note strip_dirs(): 47eb.).

          The arguments provided (if any) can be used to limit the list
          down to the significant entries.  Initially, the list is taken
          to be the complete set of profiled functions.  Each
          restriction is either an integer (to select a count of lines),
          or a decimal fraction between 0.0 and 1.0 inclusive (to select
          a percentage of lines), or a string that will be interpreted
          as a regular expression (to pattern match the standard name
          that is printed).  If several restrictions are provided, then
          they are applied sequentially.  For example:

               print_stats(.1, 'foo:')

          would first limit the printing to first 10% of list, and then
          only print functions that were part of filename ‘.*foo:’.  In
          contrast, the command:

               print_stats('foo:', .1)

          would limit the list to all functions having file names
          ‘.*foo:’, and then proceed to only print the first 10% of
          them.

      -- Metodo: print_callers (*restrictions)

          This method for the *note Stats: 47e5. class prints a list of
          all functions that called each function in the profiled
          database.  The ordering is identical to that provided by *note
          print_stats(): 47ec, and the definition of the restricting
          argument is also identical.  Each caller is reported on its
          own line.  The format differs slightly depending on the
          profiler that produced the stats:

             * With *note profile: b4, a number is shown in parentheses
               after each caller to show how many times this specific
               call was made.  For convenience, a second
               non-parenthesized number repeats the cumulative time
               spent in the function at the right.

             * With *note cProfile: 2b, each caller is preceded by three
               numbers: the number of times this specific call was made,
               and the total and cumulative times spent in the current
               function while it was invoked by this specific caller.

      -- Metodo: print_callees (*restrictions)

          This method for the *note Stats: 47e5. class prints a list of
          all function that were called by the indicated function.
          Aside from this reversal of direction of calls (re: called vs
          was called by), the arguments and ordering are identical to
          the *note print_callers(): 47fc. method.

      -- Metodo: get_stats_profile ()

          This method returns an instance of StatsProfile, which
          contains a mapping of function names to instances of
          FunctionProfile.  Each FunctionProfile instance holds
          information related to the function’s profile such as how long
          the function took to run, how many times it was called, etc…

          Added in version 3.9: Added the following dataclasses:
          StatsProfile, FunctionProfile.  Added the following function:
          get_stats_profile.


File: python.info,  Node: What Is Deterministic Profiling?,  Next: Limitations,  Prev: The Stats Class,  Up: The Python Profilers

5.27.5.5 What Is Deterministic Profiling?
.........................................

'Deterministic profiling' is meant to reflect the fact that all
'function call', 'function return', and 'exception' events are
monitored, and precise timings are made for the intervals between these
events (during which time the user’s code is executing).  In contrast,
'statistical profiling' (which is not done by this module) randomly
samples the effective instruction pointer, and deduces where time is
being spent.  The latter technique traditionally involves less overhead
(as the code does not need to be instrumented), but provides only
relative indications of where time is being spent.

In Python, since there is an interpreter active during execution, the
presence of instrumented code is not required in order to do
deterministic profiling.  Python automatically provides a 'hook'
(optional callback) for each event.  In addition, the interpreted nature
of Python tends to add so much overhead to execution, that deterministic
profiling tends to only add small processing overhead in typical
applications.  The result is that deterministic profiling is not that
expensive, yet provides extensive run time statistics about the
execution of a Python program.

Call count statistics can be used to identify bugs in code (surprising
counts), and to identify possible inline-expansion points (high call
counts).  Internal time statistics can be used to identify «hot loops»
that should be carefully optimized.  Cumulative time statistics should
be used to identify high level errors in the selection of algorithms.
Note that the unusual handling of cumulative times in this profiler
allows statistics for recursive implementations of algorithms to be
directly compared to iterative implementations.


File: python.info,  Node: Limitations,  Next: Calibration,  Prev: What Is Deterministic Profiling?,  Up: The Python Profilers

5.27.5.6 Limitations
....................

One limitation has to do with accuracy of timing information.  There is
a fundamental problem with deterministic profilers involving accuracy.
The most obvious restriction is that the underlying «clock» is only
ticking at a rate (typically) of about .001 seconds.  Hence no
measurements will be more accurate than the underlying clock.  If enough
measurements are taken, then the «error» will tend to average out.
Unfortunately, removing this first error induces a second source of
error.

The second problem is that it «takes a while» from when an event is
dispatched until the profiler’s call to get the time actually 'gets' the
state of the clock.  Similarly, there is a certain lag when exiting the
profiler event handler from the time that the clock’s value was obtained
(and then squirreled away), until the user’s code is once again
executing.  As a result, functions that are called many times, or call
many functions, will typically accumulate this error.  The error that
accumulates in this fashion is typically less than the accuracy of the
clock (less than one clock tick), but it 'can' accumulate and become
very significant.

The problem is more important with *note profile: b4. than with the
lower-overhead *note cProfile: 2b.  For this reason, *note profile: b4.
provides a means of calibrating itself for a given platform so that this
error can be probabilistically (on the average) removed.  After the
profiler is calibrated, it will be more accurate (in a least square
sense), but it will sometimes produce negative numbers (when call counts
are exceptionally low, and the gods of probability work against you :-).
)  Do 'not' be alarmed by negative numbers in the profile.  They should
'only' appear if you have calibrated your profiler, and the results are
actually better than without calibration.


File: python.info,  Node: Calibration,  Next: Using a custom timer,  Prev: Limitations,  Up: The Python Profilers

5.27.5.7 Calibration
....................

The profiler of the *note profile: b4. module subtracts a constant from
each event handling time to compensate for the overhead of calling the
time function, and socking away the results.  By default, the constant
is 0.  The following procedure can be used to obtain a better constant
for a given platform (see *note Limitations: 4802.).

     import profile
     pr = profile.Profile()
     for i in range(5):
         print(pr.calibrate(10000))

The method executes the number of Python calls given by the argument,
directly and again under the profiler, measuring the time for both.  It
then computes the hidden overhead per profiler event, and returns that
as a float.  For example, on a 1.8Ghz Intel Core i5 running macOS, and
using Python’s time.process_time() as the timer, the magical number is
about 4.04e-6.

The object of this exercise is to get a fairly consistent result.  If
your computer is 'very' fast, or your timer function has poor
resolution, you might have to pass 100000, or even 1000000, to get
consistent results.

When you have a consistent answer, there are three ways you can use it:

     import profile

     # 1. Apply computed bias to all Profile instances created hereafter.
     profile.Profile.bias = your_computed_bias

     # 2. Apply computed bias to a specific Profile instance.
     pr = profile.Profile()
     pr.bias = your_computed_bias

     # 3. Specify computed bias in instance constructor.
     pr = profile.Profile(bias=your_computed_bias)

If you have a choice, you are better off choosing a smaller constant,
and then your results will «less often» show up as negative in profile
statistics.


File: python.info,  Node: Using a custom timer,  Prev: Calibration,  Up: The Python Profilers

5.27.5.8 Using a custom timer
.............................

If you want to change how current time is determined (for example, to
force use of wall-clock time or elapsed process time), pass the timing
function you want to the ‘Profile’ class constructor:

     pr = profile.Profile(your_time_func)

The resulting profiler will then call ‘your_time_func’.  Depending on
whether you are using *note profile.Profile: bd8. or ‘cProfile.Profile’,
‘your_time_func’’s return value will be interpreted differently:

*note profile.Profile: bd8.

     ‘your_time_func’ should return a single number, or a list of
     numbers whose sum is the current time (like what *note os.times():
     131d. returns).  If the function returns a single time number, or
     the list of returned numbers has length 2, then you will get an
     especially fast version of the dispatch routine.

     Be warned that you should calibrate the profiler class for the
     timer function that you choose (see *note Calibration: 4804.).  For
     most machines, a timer that returns a lone integer value will
     provide the best results in terms of low overhead during profiling.
     (*note os.times(): 131d. is 'pretty' bad, as it returns a tuple of
     floating-point values).  If you want to substitute a better timer
     in the cleanest fashion, derive a class and hardwire a replacement
     dispatch method that best handles your timer call, along with the
     appropriate calibration constant.

‘cProfile.Profile’

     ‘your_time_func’ should return a single number.  If it returns
     integers, you can also invoke the class constructor with a second
     argument specifying the real duration of one unit of time.  For
     example, if ‘your_integer_time_func’ returns times measured in
     thousands of seconds, you would construct the ‘Profile’ instance as
     follows:

          pr = cProfile.Profile(your_integer_time_func, 0.001)

     As the ‘cProfile.Profile’ class cannot be calibrated, custom timer
     functions should be used with care and should be as fast as
     possible.  For the best results with a custom timer, it might be
     necessary to hard-code it in the C source of the internal ‘_lsprof’
     module.

Python 3.3 adds several new functions in *note time: f4. that can be
used to make precise measurements of process or wall-clock time.  For
example, see *note time.perf_counter(): c7c.


File: python.info,  Node: timeit — Measure execution time of small code snippets,  Next: trace — Trace or track Python statement execution,  Prev: The Python Profilers,  Up: Debugging and Profiling

5.27.6 ‘timeit’ — Measure execution time of small code snippets
---------------------------------------------------------------

'Source code:' Lib/timeit.py(1)

__________________________________________________________________

This module provides a simple way to time small bits of Python code.  It
has both a *note Command-Line Interface: 480a. as well as a *note
callable: 480b. one.  It avoids a number of common traps for measuring
execution times.  See also Tim Peters” introduction to the «Algorithms»
chapter in the second edition of 'Python Cookbook', published by
O’Reilly.

* Menu:

* Basic Examples: Basic Examples<2>.
* Python Interface::
* Command-Line Interface: Command-Line Interface<3>.
* Examples: Examples<31>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/timeit.py


File: python.info,  Node: Basic Examples<2>,  Next: Python Interface,  Up: timeit — Measure execution time of small code snippets

5.27.6.1 Basic Examples
.......................

The following example shows how the *note Command-Line Interface: 480a.
can be used to compare three different expressions:

     $ python -m timeit "'-'.join(str(n) for n in range(100))"
     10000 loops, best of 5: 30.2 usec per loop
     $ python -m timeit "'-'.join([str(n) for n in range(100)])"
     10000 loops, best of 5: 27.5 usec per loop
     $ python -m timeit "'-'.join(map(str, range(100)))"
     10000 loops, best of 5: 23.2 usec per loop

This can be achieved from the *note Python Interface: 480b. with:

     >>> import timeit
     >>> timeit.timeit('"-".join(str(n) for n in range(100))', number=10000)
     0.3018611848820001
     >>> timeit.timeit('"-".join([str(n) for n in range(100)])', number=10000)
     0.2727368790656328
     >>> timeit.timeit('"-".join(map(str, range(100)))', number=10000)
     0.23702679807320237

A callable can also be passed from the *note Python Interface: 480b.:

     >>> timeit.timeit(lambda: "-".join(map(str, range(100))), number=10000)
     0.19665591977536678

Note however that *note timeit(): 1080. will automatically determine the
number of repetitions only when the command-line interface is used.  In
the *note Examples: 480d. section you can find more advanced examples.


File: python.info,  Node: Python Interface,  Next: Command-Line Interface<3>,  Prev: Basic Examples<2>,  Up: timeit — Measure execution time of small code snippets

5.27.6.2 Python Interface
.........................

The module defines three convenience functions and a public class:

 -- Funzione: timeit.timeit (stmt='pass', setup='pass', timer=<default
          timer>, number=1000000, globals=None)

     Create a *note Timer: 16cf. instance with the given statement,
     'setup' code and 'timer' function and run its *note timeit(): eeb.
     method with 'number' executions.  The optional 'globals' argument
     specifies a namespace in which to execute the code.

     Cambiato nella versione 3.5: The optional 'globals' parameter was
     added.

 -- Funzione: timeit.repeat (stmt='pass', setup='pass', timer=<default
          timer>, repeat=5, number=1000000, globals=None)

     Create a *note Timer: 16cf. instance with the given statement,
     'setup' code and 'timer' function and run its *note repeat(): 4810.
     method with the given 'repeat' count and 'number' executions.  The
     optional 'globals' argument specifies a namespace in which to
     execute the code.

     Cambiato nella versione 3.5: The optional 'globals' parameter was
     added.

     Cambiato nella versione 3.7: Default value of 'repeat' changed from
     3 to 5.

 -- Funzione: timeit.default_timer ()

     The default timer, which is always time.perf_counter(), returns
     float seconds.  An alternative, time.perf_counter_ns, returns
     integer nanoseconds.

     Cambiato nella versione 3.3: *note time.perf_counter(): c7c. is now
     the default timer.

 -- Classe: timeit.Timer (stmt='pass', setup='pass', timer=<timer
          function>, globals=None)

     Class for timing execution speed of small code snippets.

     The constructor takes a statement to be timed, an additional
     statement used for setup, and a timer function.  Both statements
     default to ‘'pass'’; the timer function is platform-dependent (see
     the module doc string).  'stmt' and 'setup' may also contain
     multiple statements separated by ‘;’ or newlines, as long as they
     don’t contain multi-line string literals.  The statement will by
     default be executed within timeit’s namespace; this behavior can be
     controlled by passing a namespace to 'globals'.

     To measure the execution time of the first statement, use the *note
     timeit(): eeb. method.  The *note repeat(): 4810. and *note
     autorange(): eea. methods are convenience methods to call *note
     timeit(): eeb. multiple times.

     The execution time of 'setup' is excluded from the overall timed
     execution run.

     The 'stmt' and 'setup' parameters can also take objects that are
     callable without arguments.  This will embed calls to them in a
     timer function that will then be executed by *note timeit(): eeb.
     Note that the timing overhead is a little larger in this case
     because of the extra function calls.

     Cambiato nella versione 3.5: The optional 'globals' parameter was
     added.

      -- Metodo: timeit (number=1000000)

          Time 'number' executions of the main statement.  This executes
          the setup statement once, and then returns the time it takes
          to execute the main statement a number of times.  The default
          timer returns seconds as a float.  The argument is the number
          of times through the loop, defaulting to one million.  The
          main statement, the setup statement and the timer function to
          be used are passed to the constructor.

               Nota: By default, *note timeit(): eeb. temporarily turns
               off *note garbage collection: 17c0. during the timing.
               The advantage of this approach is that it makes
               independent timings more comparable.  The disadvantage is
               that GC may be an important component of the performance
               of the function being measured.  If so, GC can be
               re-enabled as the first statement in the 'setup' string.
               For example:

                    timeit.Timer('for i in range(10): oct(i)', 'gc.enable()').timeit()

      -- Metodo: autorange (callback=None)

          Automatically determine how many times to call *note timeit():
          eeb.

          This is a convenience function that calls *note timeit(): eeb.
          repeatedly so that the total time >= 0.2 second, returning the
          eventual (number of loops, time taken for that number of
          loops).  It calls *note timeit(): eeb. with increasing numbers
          from the sequence 1, 2, 5, 10, 20, 50, … until the time taken
          is at least 0.2 seconds.

          If 'callback' is given and is not ‘None’, it will be called
          after each trial with two arguments: ‘callback(number,
          time_taken)’.

          Added in version 3.6.

      -- Metodo: repeat (repeat=5, number=1000000)

          Call *note timeit(): eeb. a few times.

          This is a convenience function that calls the *note timeit():
          eeb. repeatedly, returning a list of results.  The first
          argument specifies how many times to call *note timeit(): eeb.
          The second argument specifies the 'number' argument for *note
          timeit(): eeb.

               Nota: It’s tempting to calculate mean and standard
               deviation from the result vector and report these.
               However, this is not very useful.  In a typical case, the
               lowest value gives a lower bound for how fast your
               machine can run the given code snippet; higher values in
               the result vector are typically not caused by variability
               in Python’s speed, but by other processes interfering
               with your timing accuracy.  So the *note min(): 110d. of
               the result is probably the only number you should be
               interested in.  After that, you should look at the entire
               vector and apply common sense rather than statistics.

          Cambiato nella versione 3.7: Default value of 'repeat' changed
          from 3 to 5.

      -- Metodo: print_exc (file=None)

          Helper to print a traceback from the timed code.

          Typical use:

               t = Timer(...)       # outside the try/except
               try:
                   t.timeit(...)    # or t.repeat(...)
               except Exception:
                   t.print_exc()

          The advantage over the standard traceback is that source lines
          in the compiled template will be displayed.  The optional
          'file' argument directs where the traceback is sent; it
          defaults to *note sys.stderr: b35.


File: python.info,  Node: Command-Line Interface<3>,  Next: Examples<31>,  Prev: Python Interface,  Up: timeit — Measure execution time of small code snippets

5.27.6.3 Command-Line Interface
...............................

When called as a program from the command line, the following form is
used:

     python -m timeit [-n N] [-r N] [-u U] [-s S] [-p] [-v] [-h] [statement ...]

Where the following options are understood:

 -- Option: -n N, --number=N

     how many times to execute “statement”

 -- Option: -r N, --repeat=N

     how many times to repeat the timer (default 5)

 -- Option: -s S, --setup=S

     statement to be executed once initially (default ‘pass’)

 -- Option: -p, --process

     measure process time, not wallclock time, using *note
     time.process_time(): c7d. instead of *note time.perf_counter():
     c7c, which is the default

     Added in version 3.3.

 -- Option: -u, --unit=U

     specify a time unit for timer output; can select ‘nsec’, ‘usec’,
     ‘msec’, or ‘sec’

     Added in version 3.5.

 -- Option: -v, --verbose

     print raw timing results; repeat for more digits precision

 -- Option: -h, --help

     print a short usage message and exit

A multi-line statement may be given by specifying each line as a
separate statement argument; indented lines are possible by enclosing an
argument in quotes and using leading spaces.  Multiple *note -s: 4818.
options are treated similarly.

If *note -n: 4814. is not given, a suitable number of loops is
calculated by trying increasing numbers from the sequence 1, 2, 5, 10,
20, 50, … until the total time is at least 0.2 seconds.

*note default_timer(): 4811. measurements can be affected by other
programs running on the same machine, so the best thing to do when
accurate timing is necessary is to repeat the timing a few times and use
the best time.  The *note -r: 4816. option is good for this; the default
of 5 repetitions is probably enough in most cases.  You can use *note
time.process_time(): c7d. to measure CPU time.

     Nota: There is a certain baseline overhead associated with
     executing a pass statement.  The code here doesn’t try to hide it,
     but you should be aware of it.  The baseline overhead can be
     measured by invoking the program without arguments, and it might
     differ between Python versions.


File: python.info,  Node: Examples<31>,  Prev: Command-Line Interface<3>,  Up: timeit — Measure execution time of small code snippets

5.27.6.4 Examples
.................

It is possible to provide a setup statement that is executed only once
at the beginning:

     $ python -m timeit -s "text = 'sample string'; char = 'g'" "char in text"
     5000000 loops, best of 5: 0.0877 usec per loop
     $ python -m timeit -s "text = 'sample string'; char = 'g'" "text.find(char)"
     1000000 loops, best of 5: 0.342 usec per loop

In the output, there are three fields.  The loop count, which tells you
how many times the statement body was run per timing loop repetition.
The repetition count (“best of 5”) which tells you how many times the
timing loop was repeated, and finally the time the statement body took
on average within the best repetition of the timing loop.  That is, the
time the fastest repetition took divided by the loop count.

     >>> import timeit
     >>> timeit.timeit('char in text', setup='text = "sample string"; char = "g"')
     0.41440500499993504
     >>> timeit.timeit('text.find(char)', setup='text = "sample string"; char = "g"')
     1.7246671520006203

The same can be done using the *note Timer: 16cf. class and its methods:

     >>> import timeit
     >>> t = timeit.Timer('char in text', setup='text = "sample string"; char = "g"')
     >>> t.timeit()
     0.3955516149999312
     >>> t.repeat()
     [0.40183617287970225, 0.37027556854118704, 0.38344867356679524, 0.3712595970846668, 0.37866875250654886]

The following examples show how to time expressions that contain
multiple lines.  Here we compare the cost of using *note hasattr(): 6fa.
vs.  *note try: 8f9./*note except: 1ab. to test for missing and present
object attributes:

     $ python -m timeit "try:" "  str.__bool__" "except AttributeError:" "  pass"
     20000 loops, best of 5: 15.7 usec per loop
     $ python -m timeit "if hasattr(str, '__bool__'): pass"
     50000 loops, best of 5: 4.26 usec per loop

     $ python -m timeit "try:" "  int.__bool__" "except AttributeError:" "  pass"
     200000 loops, best of 5: 1.43 usec per loop
     $ python -m timeit "if hasattr(int, '__bool__'): pass"
     100000 loops, best of 5: 2.23 usec per loop

     >>> import timeit
     >>> # attribute is missing
     >>> s = """\
     ... try:
     ...     str.__bool__
     ... except AttributeError:
     ...     pass
     ... """
     >>> timeit.timeit(stmt=s, number=100000)
     0.9138244460009446
     >>> s = "if hasattr(str, '__bool__'): pass"
     >>> timeit.timeit(stmt=s, number=100000)
     0.5829014980008651
     >>>
     >>> # attribute is present
     >>> s = """\
     ... try:
     ...     int.__bool__
     ... except AttributeError:
     ...     pass
     ... """
     >>> timeit.timeit(stmt=s, number=100000)
     0.04215312199994514
     >>> s = "if hasattr(int, '__bool__'): pass"
     >>> timeit.timeit(stmt=s, number=100000)
     0.08588060699912603

To give the *note timeit: f5. module access to functions you define, you
can pass a 'setup' parameter which contains an import statement:

     def test():
         """Stupid test function"""
         L = [i for i in range(100)]

     if __name__ == '__main__':
         import timeit
         print(timeit.timeit("test()", setup="from __main__ import test"))

Another option is to pass *note globals(): 1bf2. to the 'globals'
parameter, which will cause the code to be executed within your current
global namespace.  This can be more convenient than individually
specifying imports:

     def f(x):
         return x**2
     def g(x):
         return x**4
     def h(x):
         return x**8

     import timeit
     print(timeit.timeit('[func(42) for func in (f,g,h)]', globals=globals()))


File: python.info,  Node: trace — Trace or track Python statement execution,  Next: tracemalloc — Trace memory allocations,  Prev: timeit — Measure execution time of small code snippets,  Up: Debugging and Profiling

5.27.7 ‘trace’ — Trace or track Python statement execution
----------------------------------------------------------

'Source code:' Lib/trace.py(1)

__________________________________________________________________

The *note trace: 103. module allows you to trace program execution,
generate annotated statement coverage listings, print caller/callee
relationships and list functions executed during a program run.  It can
be used in another program or from the command line.

Vedi anche
..........

Coverage.py(2)

     A popular third-party coverage tool that provides HTML output along
     with advanced features such as branch coverage.

* Menu:

* Command-Line Usage: Command-Line Usage<2>.
* Programmatic Interface::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/trace.py

   (2) https://coverage.readthedocs.io/


File: python.info,  Node: Command-Line Usage<2>,  Next: Programmatic Interface,  Up: trace — Trace or track Python statement execution

5.27.7.1 Command-Line Usage
...........................

The *note trace: 103. module can be invoked from the command line.  It
can be as simple as

     python -m trace --count -C . somefile.py ...

The above will execute ‘somefile.py’ and generate annotated listings of
all Python modules imported during the execution into the current
directory.

 -- Option: --help

     Display usage and exit.

 -- Option: --version

     Display the version of the module and exit.

Added in version 3.8: Added ‘--module’ option that allows to run an
executable module.

* Menu:

* Main options::
* Modifiers::
* Filters::


File: python.info,  Node: Main options,  Next: Modifiers,  Up: Command-Line Usage<2>

5.27.7.2 Main options
.....................

At least one of the following options must be specified when invoking
*note trace: 103.  The *note -listfuncs: 482b. option is mutually
exclusive with the *note -trace: 482c. and *note -count: 482d. options.
When *note -listfuncs: 482b. is provided, neither *note -count: 482d.
nor *note -trace: 482c. are accepted, and vice versa.

 -- Option: -c, --count

     Produce a set of annotated listing files upon program completion
     that shows how many times each statement was executed.  See also
     *note -coverdir: 482f, *note -file: 4830. and *note -no-report:
     4831. below.

 -- Option: -t, --trace

     Display lines as they are executed.

 -- Option: -l, --listfuncs

     Display the functions executed by running the program.

 -- Option: -r, --report

     Produce an annotated list from an earlier program run that used the
     *note -count: 482d. and *note -file: 4830. option.  This does not
     execute any code.

 -- Option: -T, --trackcalls

     Display the calling relationships exposed by running the program.


File: python.info,  Node: Modifiers,  Next: Filters,  Prev: Main options,  Up: Command-Line Usage<2>

5.27.7.3 Modifiers
..................

 -- Option: -f, --file=<file>

     Name of a file to accumulate counts over several tracing runs.
     Should be used with the *note -count: 482d. option.

 -- Option: -C, --coverdir=<dir>

     Directory where the report files go.  The coverage report for
     ‘package.module’ is written to file
     ‘`dir'/`package'/`module'.cover’.

 -- Option: -m, --missing

     When generating annotated listings, mark lines which were not
     executed with ‘>>>>>>’.

 -- Option: -s, --summary

     When using *note -count: 482d. or *note -report: 4834, write a
     brief summary to stdout for each file processed.

 -- Option: -R, --no-report

     Do not generate annotated listings.  This is useful if you intend
     to make several runs with *note -count: 482d, and then produce a
     single set of annotated listings at the end.

 -- Option: -g, --timing

     Prefix each line with the time since the program started.  Only
     used while tracing.


File: python.info,  Node: Filters,  Prev: Modifiers,  Up: Command-Line Usage<2>

5.27.7.4 Filters
................

These options may be repeated multiple times.

 -- Option: --ignore-module=<mod>

     Ignore each of the given module names and its submodules (if it is
     a package).  The argument can be a list of names separated by a
     comma.

 -- Option: --ignore-dir=<dir>

     Ignore all modules and packages in the named directory and
     subdirectories.  The argument can be a list of directories
     separated by *note os.pathsep: 211d.


File: python.info,  Node: Programmatic Interface,  Prev: Command-Line Usage<2>,  Up: trace — Trace or track Python statement execution

5.27.7.5 Programmatic Interface
...............................

 -- Classe: trace.Trace (count=1, trace=1, countfuncs=0, countcallers=0,
          ignoremods=(), ignoredirs=(), infile=None, outfile=None,
          timing=False)

     Create an object to trace execution of a single statement or
     expression.  All parameters are optional.  'count' enables counting
     of line numbers.  'trace' enables line execution tracing.
     'countfuncs' enables listing of the functions called during the
     run.  'countcallers' enables call relationship tracking.
     'ignoremods' is a list of modules or packages to ignore.
     'ignoredirs' is a list of directories whose modules or packages
     should be ignored.  'infile' is the name of the file from which to
     read stored count information.  'outfile' is the name of the file
     in which to write updated count information.  'timing' enables a
     timestamp relative to when tracing was started to be displayed.

      -- Metodo: run (cmd)

          Execute the command and gather statistics from the execution
          with the current tracing parameters.  'cmd' must be a string
          or code object, suitable for passing into *note exec(): 4a3.

      -- Metodo: runctx (cmd, globals=None, locals=None)

          Execute the command and gather statistics from the execution
          with the current tracing parameters, in the defined global and
          local environments.  If not defined, 'globals' and 'locals'
          default to empty dictionaries.

      -- Metodo: runfunc (func, /, *args, **kwds)

          Call 'func' with the given arguments under control of the
          *note Trace: 4847. object with the current tracing parameters.

      -- Metodo: results ()

          Return a *note CoverageResults: 484b. object that contains the
          cumulative results of all previous calls to ‘run’, ‘runctx’
          and ‘runfunc’ for the given *note Trace: 4847. instance.  Does
          not reset the accumulated trace results.

 -- Classe: trace.CoverageResults

     A container for coverage results, created by *note Trace.results():
     484a.  Should not be created directly by the user.

      -- Metodo: update (other)

          Merge in data from another *note CoverageResults: 484b.
          object.

      -- Metodo: write_results (show_missing=True, summary=False,
               coverdir=None, *, ignore_missing_files=False)

          Write coverage results.  Set 'show_missing' to show lines that
          had no hits.  Set 'summary' to include in the output the
          coverage summary per module.  'coverdir' specifies the
          directory into which the coverage result files will be output.
          If ‘None’, the results for each source file are placed in its
          directory.

          If 'ignore_missing_files' is ‘True’, coverage counts for files
          that no longer exist are silently ignored.  Otherwise, a
          missing file will raise a *note FileNotFoundError: 264.

          Cambiato nella versione 3.13: Added 'ignore_missing_files'
          parameter.

A simple example demonstrating the use of the programmatic interface:

     import sys
     import trace

     # create a Trace object, telling it what to ignore, and whether to
     # do tracing or line-counting or both.
     tracer = trace.Trace(
         ignoredirs=[sys.prefix, sys.exec_prefix],
         trace=0,
         count=1)

     # run the new command using the given tracer
     tracer.run('main()')

     # make a report, placing output in the current directory
     r = tracer.results()
     r.write_results(show_missing=True, coverdir=".")


File: python.info,  Node: tracemalloc — Trace memory allocations,  Prev: trace — Trace or track Python statement execution,  Up: Debugging and Profiling

5.27.8 ‘tracemalloc’ — Trace memory allocations
-----------------------------------------------

Added in version 3.4.

'Source code:' Lib/tracemalloc.py(1)

__________________________________________________________________

The tracemalloc module is a debug tool to trace memory blocks allocated
by Python.  It provides the following information:

   * Traceback where an object was allocated

   * Statistics on allocated memory blocks per filename and per line
     number: total size, number and average size of allocated memory
     blocks

   * Compute the differences between two snapshots to detect memory
     leaks

To trace most memory blocks allocated by Python, the module should be
started as early as possible by setting the *note PYTHONTRACEMALLOC:
2116. environment variable to ‘1’, or by using *note -X: 16f.
‘tracemalloc’ command line option.  The *note tracemalloc.start(): 2115.
function can be called at runtime to start tracing Python memory
allocations.

By default, a trace of an allocated memory block only stores the most
recent frame (1 frame).  To store 25 frames at startup: set the *note
PYTHONTRACEMALLOC: 2116. environment variable to ‘25’, or use the *note
-X: 16f. ‘tracemalloc=25’ command line option.

* Menu:

* Examples: Examples<32>.
* API::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/tracemalloc.py


File: python.info,  Node: Examples<32>,  Next: API,  Up: tracemalloc — Trace memory allocations

5.27.8.1 Examples
.................

* Menu:

* Display the top 10::
* Compute differences::
* Get the traceback of a memory block::
* Pretty top::


File: python.info,  Node: Display the top 10,  Next: Compute differences,  Up: Examples<32>

5.27.8.2 Display the top 10
...........................

Display the 10 files allocating the most memory:

     import tracemalloc

     tracemalloc.start()

     # ... run your application ...

     snapshot = tracemalloc.take_snapshot()
     top_stats = snapshot.statistics('lineno')

     print("[ Top 10 ]")
     for stat in top_stats[:10]:
         print(stat)

Example of output of the Python test suite:

     [ Top 10 ]
     <frozen importlib._bootstrap>:716: size=4855 KiB, count=39328, average=126 B
     <frozen importlib._bootstrap>:284: size=521 KiB, count=3199, average=167 B
     /usr/lib/python3.4/collections/__init__.py:368: size=244 KiB, count=2315, average=108 B
     /usr/lib/python3.4/unittest/case.py:381: size=185 KiB, count=779, average=243 B
     /usr/lib/python3.4/unittest/case.py:402: size=154 KiB, count=378, average=416 B
     /usr/lib/python3.4/abc.py:133: size=88.7 KiB, count=347, average=262 B
     <frozen importlib._bootstrap>:1446: size=70.4 KiB, count=911, average=79 B
     <frozen importlib._bootstrap>:1454: size=52.0 KiB, count=25, average=2131 B
     <string>:5: size=49.7 KiB, count=148, average=344 B
     /usr/lib/python3.4/sysconfig.py:411: size=48.0 KiB, count=1, average=48.0 KiB

We can see that Python loaded ‘4855 KiB’ data (bytecode and constants)
from modules and that the *note collections: 1e. module allocated ‘244
KiB’ to build *note namedtuple: 4e1. types.

See *note Snapshot.statistics(): 4853. for more options.


File: python.info,  Node: Compute differences,  Next: Get the traceback of a memory block,  Prev: Display the top 10,  Up: Examples<32>

5.27.8.3 Compute differences
............................

Take two snapshots and display the differences:

     import tracemalloc
     tracemalloc.start()
     # ... start your application ...

     snapshot1 = tracemalloc.take_snapshot()
     # ... call the function leaking memory ...
     snapshot2 = tracemalloc.take_snapshot()

     top_stats = snapshot2.compare_to(snapshot1, 'lineno')

     print("[ Top 10 differences ]")
     for stat in top_stats[:10]:
         print(stat)

Example of output before/after running some tests of the Python test
suite:

     [ Top 10 differences ]
     <frozen importlib._bootstrap>:716: size=8173 KiB (+4428 KiB), count=71332 (+39369), average=117 B
     /usr/lib/python3.4/linecache.py:127: size=940 KiB (+940 KiB), count=8106 (+8106), average=119 B
     /usr/lib/python3.4/unittest/case.py:571: size=298 KiB (+298 KiB), count=589 (+589), average=519 B
     <frozen importlib._bootstrap>:284: size=1005 KiB (+166 KiB), count=7423 (+1526), average=139 B
     /usr/lib/python3.4/mimetypes.py:217: size=112 KiB (+112 KiB), count=1334 (+1334), average=86 B
     /usr/lib/python3.4/http/server.py:848: size=96.0 KiB (+96.0 KiB), count=1 (+1), average=96.0 KiB
     /usr/lib/python3.4/inspect.py:1465: size=83.5 KiB (+83.5 KiB), count=109 (+109), average=784 B
     /usr/lib/python3.4/unittest/mock.py:491: size=77.7 KiB (+77.7 KiB), count=143 (+143), average=557 B
     /usr/lib/python3.4/urllib/parse.py:476: size=71.8 KiB (+71.8 KiB), count=969 (+969), average=76 B
     /usr/lib/python3.4/contextlib.py:38: size=67.2 KiB (+67.2 KiB), count=126 (+126), average=546 B

We can see that Python has loaded ‘8173 KiB’ of module data (bytecode
and constants), and that this is ‘4428 KiB’ more than had been loaded
before the tests, when the previous snapshot was taken.  Similarly, the
*note linecache: 89. module has cached ‘940 KiB’ of Python source code
to format tracebacks, all of it since the previous snapshot.

If the system has little free memory, snapshots can be written on disk
using the *note Snapshot.dump(): 4855. method to analyze the snapshot
offline.  Then use the *note Snapshot.load(): 4856. method reload the
snapshot.


File: python.info,  Node: Get the traceback of a memory block,  Next: Pretty top,  Prev: Compute differences,  Up: Examples<32>

5.27.8.4 Get the traceback of a memory block
............................................

Code to display the traceback of the biggest memory block:

     import tracemalloc

     # Store 25 frames
     tracemalloc.start(25)

     # ... run your application ...

     snapshot = tracemalloc.take_snapshot()
     top_stats = snapshot.statistics('traceback')

     # pick the biggest memory block
     stat = top_stats[0]
     print("%s memory blocks: %.1f KiB" % (stat.count, stat.size / 1024))
     for line in stat.traceback.format():
         print(line)

Example of output of the Python test suite (traceback limited to 25
frames):

     903 memory blocks: 870.1 KiB
       File "<frozen importlib._bootstrap>", line 716
       File "<frozen importlib._bootstrap>", line 1036
       File "<frozen importlib._bootstrap>", line 934
       File "<frozen importlib._bootstrap>", line 1068
       File "<frozen importlib._bootstrap>", line 619
       File "<frozen importlib._bootstrap>", line 1581
       File "<frozen importlib._bootstrap>", line 1614
       File "/usr/lib/python3.4/doctest.py", line 101
         import pdb
       File "<frozen importlib._bootstrap>", line 284
       File "<frozen importlib._bootstrap>", line 938
       File "<frozen importlib._bootstrap>", line 1068
       File "<frozen importlib._bootstrap>", line 619
       File "<frozen importlib._bootstrap>", line 1581
       File "<frozen importlib._bootstrap>", line 1614
       File "/usr/lib/python3.4/test/support/__init__.py", line 1728
         import doctest
       File "/usr/lib/python3.4/test/test_pickletools.py", line 21
         support.run_doctest(pickletools)
       File "/usr/lib/python3.4/test/regrtest.py", line 1276
         test_runner()
       File "/usr/lib/python3.4/test/regrtest.py", line 976
         display_failure=not verbose)
       File "/usr/lib/python3.4/test/regrtest.py", line 761
         match_tests=ns.match_tests)
       File "/usr/lib/python3.4/test/regrtest.py", line 1563
         main()
       File "/usr/lib/python3.4/test/__main__.py", line 3
         regrtest.main_in_temp_cwd()
       File "/usr/lib/python3.4/runpy.py", line 73
         exec(code, run_globals)
       File "/usr/lib/python3.4/runpy.py", line 160
         "__main__", fname, loader, pkg_name)

We can see that the most memory was allocated in the *note importlib:
7b. module to load data (bytecode and constants) from modules: ‘870.1
KiB’.  The traceback is where the *note importlib: 7b. loaded data most
recently: on the ‘import pdb’ line of the *note doctest: 3e. module.
The traceback may change if a new module is loaded.


File: python.info,  Node: Pretty top,  Prev: Get the traceback of a memory block,  Up: Examples<32>

5.27.8.5 Pretty top
...................

Code to display the 10 lines allocating the most memory with a pretty
output, ignoring ‘<frozen importlib._bootstrap>’ and ‘<unknown>’ files:

     import linecache
     import os
     import tracemalloc

     def display_top(snapshot, key_type='lineno', limit=10):
         snapshot = snapshot.filter_traces((
             tracemalloc.Filter(False, "<frozen importlib._bootstrap>"),
             tracemalloc.Filter(False, "<unknown>"),
         ))
         top_stats = snapshot.statistics(key_type)

         print("Top %s lines" % limit)
         for index, stat in enumerate(top_stats[:limit], 1):
             frame = stat.traceback[0]
             print("#%s: %s:%s: %.1f KiB"
                   % (index, frame.filename, frame.lineno, stat.size / 1024))
             line = linecache.getline(frame.filename, frame.lineno).strip()
             if line:
                 print('    %s' % line)

         other = top_stats[limit:]
         if other:
             size = sum(stat.size for stat in other)
             print("%s other: %.1f KiB" % (len(other), size / 1024))
         total = sum(stat.size for stat in top_stats)
         print("Total allocated size: %.1f KiB" % (total / 1024))

     tracemalloc.start()

     # ... run your application ...

     snapshot = tracemalloc.take_snapshot()
     display_top(snapshot)

Example of output of the Python test suite:

     Top 10 lines
     #1: Lib/base64.py:414: 419.8 KiB
         _b85chars2 = [(a + b) for a in _b85chars for b in _b85chars]
     #2: Lib/base64.py:306: 419.8 KiB
         _a85chars2 = [(a + b) for a in _a85chars for b in _a85chars]
     #3: collections/__init__.py:368: 293.6 KiB
         exec(class_definition, namespace)
     #4: Lib/abc.py:133: 115.2 KiB
         cls = super().__new__(mcls, name, bases, namespace)
     #5: unittest/case.py:574: 103.1 KiB
         testMethod()
     #6: Lib/linecache.py:127: 95.4 KiB
         lines = fp.readlines()
     #7: urllib/parse.py:476: 71.8 KiB
         for a in _hexdig for b in _hexdig}
     #8: <string>:5: 62.0 KiB
     #9: Lib/_weakrefset.py:37: 60.0 KiB
         self.data = set()
     #10: Lib/base64.py:142: 59.8 KiB
         _b32tab2 = [a + b for a in _b32tab for b in _b32tab]
     6220 other: 3602.8 KiB
     Total allocated size: 5303.1 KiB

See *note Snapshot.statistics(): 4853. for more options.

* Menu:

* Record the current and peak size of all traced memory blocks::


File: python.info,  Node: Record the current and peak size of all traced memory blocks,  Up: Pretty top

5.27.8.6 Record the current and peak size of all traced memory blocks
.....................................................................

The following code computes two sums like ‘0 + 1 + 2 + ...’
inefficiently, by creating a list of those numbers.  This list consumes
a lot of memory temporarily.  We can use *note get_traced_memory():
485a. and *note reset_peak(): b37. to observe the small memory usage
after the sum is computed as well as the peak memory usage during the
computations:

     import tracemalloc

     tracemalloc.start()

     # Example code: compute a sum with a large temporary list
     large_sum = sum(list(range(100000)))

     first_size, first_peak = tracemalloc.get_traced_memory()

     tracemalloc.reset_peak()

     # Example code: compute a sum with a small temporary list
     small_sum = sum(list(range(1000)))

     second_size, second_peak = tracemalloc.get_traced_memory()

     print(f"{first_size=}, {first_peak=}")
     print(f"{second_size=}, {second_peak=}")

Output:

     first_size=664, first_peak=3592984
     second_size=804, second_peak=29704

Using *note reset_peak(): b37. ensured we could accurately record the
peak during the computation of ‘small_sum’, even though it is much
smaller than the overall peak size of memory blocks since the *note
start(): 2115. call.  Without the call to *note reset_peak(): b37,
‘second_peak’ would still be the peak from the computation ‘large_sum’
(that is, equal to ‘first_peak’).  In this case, both peaks are much
higher than the final memory usage, and which suggests we could optimise
(by removing the unnecessary call to *note list: 24d, and writing
‘sum(range(...))’).


File: python.info,  Node: API,  Prev: Examples<32>,  Up: tracemalloc — Trace memory allocations

5.27.8.7 API
............

* Menu:

* Functions: Functions<10>.
* DomainFilter::
* Filter::
* Frame::
* Snapshot::
* Statistic::
* StatisticDiff::
* Trace::
* Traceback::


File: python.info,  Node: Functions<10>,  Next: DomainFilter,  Up: API

5.27.8.8 Functions
..................

 -- Funzione: tracemalloc.clear_traces ()

     Clear traces of memory blocks allocated by Python.

     See also *note stop(): 1895.

 -- Funzione: tracemalloc.get_object_traceback (obj)

     Get the traceback where the Python object 'obj' was allocated.
     Return a *note Traceback: d91. instance, or ‘None’ if the *note
     tracemalloc: 105. module is not tracing memory allocations or did
     not trace the allocation of the object.

     See also *note gc.get_referrers(): a07. and *note sys.getsizeof():
     1ac3. functions.

 -- Funzione: tracemalloc.get_traceback_limit ()

     Get the maximum number of frames stored in the traceback of a
     trace.

     The *note tracemalloc: 105. module must be tracing memory
     allocations to get the limit, otherwise an exception is raised.

     The limit is set by the *note start(): 2115. function.

 -- Funzione: tracemalloc.get_traced_memory ()

     Get the current size and peak size of memory blocks traced by the
     *note tracemalloc: 105. module as a tuple: ‘(current: int, peak:
     int)’.

 -- Funzione: tracemalloc.reset_peak ()

     Set the peak size of memory blocks traced by the *note tracemalloc:
     105. module to the current size.

     Do nothing if the *note tracemalloc: 105. module is not tracing
     memory allocations.

     This function only modifies the recorded peak size, and does not
     modify or clear any traces, unlike *note clear_traces(): 485d.
     Snapshots taken with *note take_snapshot(): 485f. before a call to
     *note reset_peak(): b37. can be meaningfully compared to snapshots
     taken after the call.

     See also *note get_traced_memory(): 485a.

     Added in version 3.9.

 -- Funzione: tracemalloc.get_tracemalloc_memory ()

     Get the memory usage in bytes of the *note tracemalloc: 105. module
     used to store traces of memory blocks.  Return an *note int: 19b.

 -- Funzione: tracemalloc.is_tracing ()

     ‘True’ if the *note tracemalloc: 105. module is tracing Python
     memory allocations, ‘False’ otherwise.

     See also *note start(): 2115. and *note stop(): 1895. functions.

 -- Funzione: tracemalloc.start (nframe: int = 1)

     Start tracing Python memory allocations: install hooks on Python
     memory allocators.  Collected tracebacks of traces will be limited
     to 'nframe' frames.  By default, a trace of a memory block only
     stores the most recent frame: the limit is ‘1’.  'nframe' must be
     greater or equal to ‘1’.

     You can still read the original number of total frames that
     composed the traceback by looking at the *note
     Traceback.total_nframe: 4862. attribute.

     Storing more than ‘1’ frame is only useful to compute statistics
     grouped by ‘'traceback'’ or to compute cumulative statistics: see
     the *note Snapshot.compare_to(): 4863. and *note
     Snapshot.statistics(): 4853. methods.

     Storing more frames increases the memory and CPU overhead of the
     *note tracemalloc: 105. module.  Use the *note
     get_tracemalloc_memory(): 4860. function to measure how much memory
     is used by the *note tracemalloc: 105. module.

     The *note PYTHONTRACEMALLOC: 2116. environment variable
     (‘PYTHONTRACEMALLOC=NFRAME’) and the *note -X: 16f.
     ‘tracemalloc=NFRAME’ command line option can be used to start
     tracing at startup.

     See also *note stop(): 1895, *note is_tracing(): 4861. and *note
     get_traceback_limit(): 485e. functions.

 -- Funzione: tracemalloc.stop ()

     Stop tracing Python memory allocations: uninstall hooks on Python
     memory allocators.  Also clears all previously collected traces of
     memory blocks allocated by Python.

     Call *note take_snapshot(): 485f. function to take a snapshot of
     traces before clearing them.

     See also *note start(): 2115, *note is_tracing(): 4861. and *note
     clear_traces(): 485d. functions.

 -- Funzione: tracemalloc.take_snapshot ()

     Take a snapshot of traces of memory blocks allocated by Python.
     Return a new *note Snapshot: 4864. instance.

     The snapshot does not include memory blocks allocated before the
     *note tracemalloc: 105. module started to trace memory allocations.

     Tracebacks of traces are limited to *note get_traceback_limit():
     485e. frames.  Use the 'nframe' parameter of the *note start():
     2115. function to store more frames.

     The *note tracemalloc: 105. module must be tracing memory
     allocations to take a snapshot, see the *note start(): 2115.
     function.

     See also the *note get_object_traceback(): 1f21. function.


File: python.info,  Node: DomainFilter,  Next: Filter,  Prev: Functions<10>,  Up: API

5.27.8.9 DomainFilter
.....................

 -- Classe: tracemalloc.DomainFilter (inclusive: bool, domain: int)

     Filter traces of memory blocks by their address space (domain).

     Added in version 3.6.

      -- Attributo: inclusive

          If 'inclusive' is ‘True’ (include), match memory blocks
          allocated in the address space *note domain: 4867.

          If 'inclusive' is ‘False’ (exclude), match memory blocks not
          allocated in the address space *note domain: 4867.

      -- Attributo: domain

          Address space of a memory block (‘int’).  Read-only property.


File: python.info,  Node: Filter,  Next: Frame,  Prev: DomainFilter,  Up: API

5.27.8.10 Filter
................

 -- Classe: tracemalloc.Filter (inclusive: bool, filename_pattern: str,
          lineno: int = None, all_frames: bool = False, domain: int =
          None)

     Filter on traces of memory blocks.

     See the *note fnmatch.fnmatch(): 1c3c. function for the syntax of
     'filename_pattern'.  The ‘'.pyc'’ file extension is replaced with
     ‘'.py'’.

     Examples:

        * ‘Filter(True, subprocess.__file__)’ only includes traces of
          the *note subprocess: dc. module

        * ‘Filter(False, tracemalloc.__file__)’ excludes traces of the
          *note tracemalloc: 105. module

        * ‘Filter(False, "<unknown>")’ excludes empty tracebacks

     Cambiato nella versione 3.5: The ‘'.pyo'’ file extension is no
     longer replaced with ‘'.py'’.

     Cambiato nella versione 3.6: Added the *note domain: 486a.
     attribute.

      -- Attributo: domain

          Address space of a memory block (‘int’ or ‘None’).

          tracemalloc uses the domain ‘0’ to trace memory allocations
          made by Python.  C extensions can use other domains to trace
          other resources.

      -- Attributo: inclusive

          If 'inclusive' is ‘True’ (include), only match memory blocks
          allocated in a file with a name matching *note
          filename_pattern: 486c. at line number *note lineno: 486d.

          If 'inclusive' is ‘False’ (exclude), ignore memory blocks
          allocated in a file with a name matching *note
          filename_pattern: 486c. at line number *note lineno: 486d.

      -- Attributo: lineno

          Line number (‘int’) of the filter.  If 'lineno' is ‘None’, the
          filter matches any line number.

      -- Attributo: filename_pattern

          Filename pattern of the filter (‘str’).  Read-only property.

      -- Attributo: all_frames

          If 'all_frames' is ‘True’, all frames of the traceback are
          checked.  If 'all_frames' is ‘False’, only the most recent
          frame is checked.

          This attribute has no effect if the traceback limit is ‘1’.
          See the *note get_traceback_limit(): 485e. function and *note
          Snapshot.traceback_limit: 486f. attribute.


File: python.info,  Node: Frame,  Next: Snapshot,  Prev: Filter,  Up: API

5.27.8.11 Frame
...............

 -- Classe: tracemalloc.Frame

     Frame of a traceback.

     The *note Traceback: d91. class is a sequence of *note Frame: 4871.
     instances.

      -- Attributo: filename

          Filename (‘str’).

      -- Attributo: lineno

          Line number (‘int’).


File: python.info,  Node: Snapshot,  Next: Statistic,  Prev: Frame,  Up: API

5.27.8.12 Snapshot
..................

 -- Classe: tracemalloc.Snapshot

     Snapshot of traces of memory blocks allocated by Python.

     The *note take_snapshot(): 485f. function creates a snapshot
     instance.

      -- Metodo: compare_to (old_snapshot: Snapshot, key_type: str,
               cumulative: bool = False)

          Compute the differences with an old snapshot.  Get statistics
          as a sorted list of *note StatisticDiff: 4875. instances
          grouped by 'key_type'.

          See the *note Snapshot.statistics(): 4853. method for
          'key_type' and 'cumulative' parameters.

          The result is sorted from the biggest to the smallest by:
          absolute value of *note StatisticDiff.size_diff: 4876, *note
          StatisticDiff.size: 4877, absolute value of *note
          StatisticDiff.count_diff: 4878, *note Statistic.count: 4879.
          and then by *note StatisticDiff.traceback: 487a.

      -- Metodo: dump (filename)

          Write the snapshot into a file.

          Use *note load(): 4856. to reload the snapshot.

      -- Metodo: filter_traces (filters)

          Create a new *note Snapshot: 4864. instance with a filtered
          *note traces: 487c. sequence, 'filters' is a list of *note
          DomainFilter: eef. and *note Filter: 4869. instances.  If
          'filters' is an empty list, return a new *note Snapshot: 4864.
          instance with a copy of the traces.

          All inclusive filters are applied at once, a trace is ignored
          if no inclusive filters match it.  A trace is ignored if at
          least one exclusive filter matches it.

          Cambiato nella versione 3.6: *note DomainFilter: eef.
          instances are now also accepted in 'filters'.

      -- Metodo: classmethod load (filename)

          Load a snapshot from a file.

          See also *note dump(): 4855.

      -- Metodo: statistics (key_type: str, cumulative: bool = False)

          Get statistics as a sorted list of *note Statistic: 487d.
          instances grouped by 'key_type':

          key_type                  description
                                    
          -------------------------------------------------------
                                    
          ‘'filename'’              filename
                                    
                                    
          ‘'lineno'’                filename and line number
                                    
                                    
          ‘'traceback'’             traceback
                                    

          If 'cumulative' is ‘True’, cumulate size and count of memory
          blocks of all frames of the traceback of a trace, not only the
          most recent frame.  The cumulative mode can only be used with
          'key_type' equals to ‘'filename'’ and ‘'lineno'’.

          The result is sorted from the biggest to the smallest by:
          *note Statistic.size: 487e, *note Statistic.count: 4879. and
          then by *note Statistic.traceback: 487f.

      -- Attributo: traceback_limit

          Maximum number of frames stored in the traceback of *note
          traces: 487c.: result of the *note get_traceback_limit():
          485e. when the snapshot was taken.

      -- Attributo: traces

          Traces of all memory blocks allocated by Python: sequence of
          *note Trace: 4880. instances.

          The sequence has an undefined order.  Use the *note
          Snapshot.statistics(): 4853. method to get a sorted list of
          statistics.


File: python.info,  Node: Statistic,  Next: StatisticDiff,  Prev: Snapshot,  Up: API

5.27.8.13 Statistic
...................

 -- Classe: tracemalloc.Statistic

     Statistic on memory allocations.

     *note Snapshot.statistics(): 4853. returns a list of *note
     Statistic: 487d. instances.

     See also the *note StatisticDiff: 4875. class.

      -- Attributo: count

          Number of memory blocks (‘int’).

      -- Attributo: size

          Total size of memory blocks in bytes (‘int’).

      -- Attributo: traceback

          Traceback where the memory block was allocated, *note
          Traceback: d91. instance.


File: python.info,  Node: StatisticDiff,  Next: Trace,  Prev: Statistic,  Up: API

5.27.8.14 StatisticDiff
.......................

 -- Classe: tracemalloc.StatisticDiff

     Statistic difference on memory allocations between an old and a new
     *note Snapshot: 4864. instance.

     *note Snapshot.compare_to(): 4863. returns a list of *note
     StatisticDiff: 4875. instances.  See also the *note Statistic:
     487d. class.

      -- Attributo: count

          Number of memory blocks in the new snapshot (‘int’): ‘0’ if
          the memory blocks have been released in the new snapshot.

      -- Attributo: count_diff

          Difference of number of memory blocks between the old and the
          new snapshots (‘int’): ‘0’ if the memory blocks have been
          allocated in the new snapshot.

      -- Attributo: size

          Total size of memory blocks in bytes in the new snapshot
          (‘int’): ‘0’ if the memory blocks have been released in the
          new snapshot.

      -- Attributo: size_diff

          Difference of total size of memory blocks in bytes between the
          old and the new snapshots (‘int’): ‘0’ if the memory blocks
          have been allocated in the new snapshot.

      -- Attributo: traceback

          Traceback where the memory blocks were allocated, *note
          Traceback: d91. instance.


File: python.info,  Node: Trace,  Next: Traceback,  Prev: StatisticDiff,  Up: API

5.27.8.15 Trace
...............

 -- Classe: tracemalloc.Trace

     Trace of a memory block.

     The *note Snapshot.traces: 487c. attribute is a sequence of *note
     Trace: 4880. instances.

     Cambiato nella versione 3.6: Added the *note domain: 4885.
     attribute.

      -- Attributo: domain

          Address space of a memory block (‘int’).  Read-only property.

          tracemalloc uses the domain ‘0’ to trace memory allocations
          made by Python.  C extensions can use other domains to trace
          other resources.

      -- Attributo: size

          Size of the memory block in bytes (‘int’).

      -- Attributo: traceback

          Traceback where the memory block was allocated, *note
          Traceback: d91. instance.


File: python.info,  Node: Traceback,  Prev: Trace,  Up: API

5.27.8.16 Traceback
...................

 -- Classe: tracemalloc.Traceback

     Sequence of *note Frame: 4871. instances sorted from the oldest
     frame to the most recent frame.

     A traceback contains at least ‘1’ frame.  If the ‘tracemalloc’
     module failed to get a frame, the filename ‘"<unknown>"’ at line
     number ‘0’ is used.

     When a snapshot is taken, tracebacks of traces are limited to *note
     get_traceback_limit(): 485e. frames.  See the *note
     take_snapshot(): 485f. function.  The original number of frames of
     the traceback is stored in the *note Traceback.total_nframe: 4862.
     attribute.  That allows to know if a traceback has been truncated
     by the traceback limit.

     The *note Trace.traceback: 4887. attribute is an instance of *note
     Traceback: d91. instance.

     Cambiato nella versione 3.7: Frames are now sorted from the oldest
     to the most recent, instead of most recent to oldest.

      -- Attributo: total_nframe

          Total number of frames that composed the traceback before
          truncation.  This attribute can be set to ‘None’ if the
          information is not available.

     Cambiato nella versione 3.9: The *note Traceback.total_nframe:
     4862. attribute was added.

      -- Metodo: format (limit=None, most_recent_first=False)

          Format the traceback as a list of lines.  Use the *note
          linecache: 89. module to retrieve lines from the source code.
          If 'limit' is set, format the 'limit' most recent frames if
          'limit' is positive.  Otherwise, format the ‘abs(limit)’
          oldest frames.  If 'most_recent_first' is ‘True’, the order of
          the formatted frames is reversed, returning the most recent
          frame first instead of last.

          Similar to the *note traceback.format_tb(): 4889. function,
          except that *note format(): d92. does not include newlines.

          Example:

               print("Traceback (most recent call first):")
               for line in traceback:
                   print(line)

          Output:

               Traceback (most recent call first):
                 File "test.py", line 9
                   obj = Object()
                 File "test.py", line 12
                   tb = tracemalloc.get_object_traceback(f())


File: python.info,  Node: Software Packaging and Distribution,  Next: Python Runtime Services,  Prev: Debugging and Profiling,  Up: The Python Standard Library

5.28 Software Packaging and Distribution
========================================

These libraries help you with publishing and installing Python software.
While these modules are designed to work in conjunction with the Python
Package Index(1), they can also be used with a local index server, or
without any index server at all.

* Menu:

* ensurepip — Bootstrapping the pip installer::
* venv — Creation of virtual environments::
* zipapp — Manage executable Python zip archives::

   ---------- Footnotes ----------

   (1) https://pypi.org


File: python.info,  Node: ensurepip — Bootstrapping the pip installer,  Next: venv — Creation of virtual environments,  Up: Software Packaging and Distribution

5.28.1 ‘ensurepip’ — Bootstrapping the ‘pip’ installer
------------------------------------------------------

Added in version 3.4.

'Source code:' Lib/ensurepip(1)

__________________________________________________________________

The *note ensurepip: 59. package provides support for bootstrapping the
‘pip’ installer into an existing Python installation or virtual
environment.  This bootstrapping approach reflects the fact that ‘pip’
is an independent project with its own release cycle, and the latest
available stable version is bundled with maintenance and feature
releases of the CPython reference interpreter.

In most cases, end users of Python shouldn’t need to invoke this module
directly (as ‘pip’ should be bootstrapped by default), but it may be
needed if installing ‘pip’ was skipped when installing Python (or when
creating a virtual environment) or after explicitly uninstalling ‘pip’.

     Nota: This module 'does not' access the internet.  All of the
     components needed to bootstrap ‘pip’ are included as internal parts
     of the package.

This is an *note optional module: 2143.  If it is missing from your copy
of CPython, look for documentation from your distributor (that is,
whoever provided Python to you).  If you are the distributor, see *note
Requirements for optional modules: 2141.

Vedi anche
..........

*note Installing Python Modules: 10fa.

     The end user guide for installing Python packages

PEP 453(2): Explicit bootstrapping of pip in Python installations

     The original rationale and specification for this module.

*note Availability: 2128.: not Android, not iOS, not WASI.

This module is not supported on *note mobile platforms: 2245. or *note
WebAssembly platforms: 1b52.

* Menu:

* Command-line interface: Command-line interface<9>.
* Module API::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/ensurepip

   (2) https://peps.python.org/pep-0453/


File: python.info,  Node: Command-line interface<9>,  Next: Module API,  Up: ensurepip — Bootstrapping the pip installer

5.28.1.1 Command-line interface
...............................

The command line interface is invoked using the interpreter’s ‘-m’
switch.

The simplest possible invocation is:

     python -m ensurepip

This invocation will install ‘pip’ if it is not already installed, but
otherwise does nothing.  To ensure the installed version of ‘pip’ is at
least as recent as the one available in ‘ensurepip’, pass the
‘--upgrade’ option:

     python -m ensurepip --upgrade

By default, ‘pip’ is installed into the current virtual environment (if
one is active) or into the system site packages (if there is no active
virtual environment).  The installation location can be controlled
through two additional command line options:

 -- Option: --root <dir>

     Installs ‘pip’ relative to the given root directory rather than the
     root of the currently active virtual environment (if any) or the
     default root for the current Python installation.

 -- Option: --user

     Installs ‘pip’ into the user site packages directory rather than
     globally for the current Python installation (this option is not
     permitted inside an active virtual environment).

By default, the scripts ‘pipX’ and ‘pipX.Y’ will be installed (where X.Y
stands for the version of Python used to invoke ‘ensurepip’).  The
scripts installed can be controlled through two additional command line
options:

 -- Option: --altinstall

     If an alternate installation is requested, the ‘pipX’ script will
     'not' be installed.

 -- Option: --default-pip

     If a «default pip» installation is requested, the ‘pip’ script will
     be installed in addition to the two regular scripts.

Providing both of the script selection options will trigger an
exception.


File: python.info,  Node: Module API,  Prev: Command-line interface<9>,  Up: ensurepip — Bootstrapping the pip installer

5.28.1.2 Module API
...................

*note ensurepip: 59. exposes two functions for programmatic use:

 -- Funzione: ensurepip.version ()

     Returns a string specifying the available version of pip that will
     be installed when bootstrapping an environment.

 -- Funzione: ensurepip.bootstrap (root=None, upgrade=False, user=False,
          altinstall=False, default_pip=False, verbosity=0)

     Bootstraps ‘pip’ into the current or designated environment.

     'root' specifies an alternative root directory to install relative
     to.  If 'root' is ‘None’, then installation uses the default
     install location for the current environment.

     'upgrade' indicates whether or not to upgrade an existing
     installation of an earlier version of ‘pip’ to the available
     version.

     'user' indicates whether to use the user scheme rather than
     installing globally.

     By default, the scripts ‘pipX’ and ‘pipX.Y’ will be installed
     (where X.Y stands for the current version of Python).

     If 'altinstall' is set, then ‘pipX’ will 'not' be installed.

     If 'default_pip' is set, then ‘pip’ will be installed in addition
     to the two regular scripts.

     Setting both 'altinstall' and 'default_pip' will trigger *note
     ValueError: 2ec.

     'verbosity' controls the level of output to *note sys.stdout: ccf.
     from the bootstrapping operation.

     Raises an *note auditing event: 1c56. ‘ensurepip.bootstrap’ with
     argument ‘root’.

          Nota: The bootstrapping process has side effects on both
          ‘sys.path’ and ‘os.environ’.  Invoking the command line
          interface in a subprocess instead allows these side effects to
          be avoided.

          Nota: The bootstrapping process may install additional modules
          required by ‘pip’, but other software should not assume those
          dependencies will always be present by default (as the
          dependencies may be removed in a future version of ‘pip’).


File: python.info,  Node: venv — Creation of virtual environments,  Next: zipapp — Manage executable Python zip archives,  Prev: ensurepip — Bootstrapping the pip installer,  Up: Software Packaging and Distribution

5.28.2 ‘venv’ — Creation of virtual environments
------------------------------------------------

Added in version 3.3.

'Source code:' Lib/venv/(1)

__________________________________________________________________

The ‘venv’ module supports creating lightweight «virtual environments»,
each with their own independent set of Python packages installed in
their *note site: cc. directories.  A virtual environment is created on
top of an existing Python installation, known as the virtual
environment’s «base» Python, and by default is isolated from the
packages in the base environment, so that only those explicitly
installed in the virtual environment are available.  See *note Virtual
Environments: 489b. and *note site: cc.’s *note virtual environments
documentation: 489c. for more information.

When used from within a virtual environment, common installation tools
such as pip(2) will install Python packages into a virtual environment
without needing to be told to do so explicitly.

A virtual environment is (amongst other things):

   * Used to contain a specific Python interpreter and software
     libraries and binaries which are needed to support a project
     (library or application).  These are by default isolated from
     software in other virtual environments and Python interpreters and
     libraries installed in the operating system.

   * Contained in a directory, conventionally named ‘.venv’ or ‘venv’ in
     the project directory, or under a container directory for lots of
     virtual environments, such as ‘~/.virtualenvs’.

   * Not checked into source control systems such as Git.

   * Considered as disposable – it should be simple to delete and
     recreate it from scratch.  You don’t place any project code in the
     environment.

   * Not considered as movable or copyable – you just recreate the same
     environment in the target location.

See PEP 405(3) for more background on Python virtual environments.

Vedi anche
..........

Python Packaging User Guide: Creating and using virtual environments(4)

*note Availability: 2128.: not Android, not iOS, not WASI.

This module is not supported on *note mobile platforms: 2245. or *note
WebAssembly platforms: 1b52.

* Menu:

* Creating virtual environments::
* How venvs work::
* API: API<2>.
* An example of extending EnvBuilder::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/venv/

   (2) https://pypi.org/project/pip/

   (3) https://peps.python.org/pep-0405/

   (4) 
https://packaging.python.org/guides/installing-using-pip-and-virtual-environments/#create-and-use-virtual-environments


File: python.info,  Node: Creating virtual environments,  Next: How venvs work,  Up: venv — Creation of virtual environments

5.28.2.1 Creating virtual environments
......................................

*note Virtual environments: 3e8. are created by executing the ‘venv’
module:

     python -m venv /path/to/new/virtual/environment

This creates the target directory (including parent directories as
needed) and places a ‘pyvenv.cfg’ file in it with a ‘home’ key pointing
to the Python installation from which the command was run.  It also
creates a ‘bin’ (or ‘Scripts’ on Windows) subdirectory containing a copy
or symlink of the Python executable (as appropriate for the platform or
arguments used at environment creation time).  It also creates a
‘lib/pythonX.Y/site-packages’ subdirectory (on Windows, this is
‘Lib\site-packages’).  If an existing directory is specified, it will be
re-used.

Cambiato nella versione 3.5: The use of ‘venv’ is now recommended for
creating virtual environments.

Deprecated since version 3.6, removed in version 3.8: ‘pyvenv’ was the
recommended tool for creating virtual environments for Python 3.3 and
3.4, and replaced in 3.5 by executing ‘venv’ directly.

On Windows, invoke the ‘venv’ command as follows:

     PS> python -m venv C:\path\to\new\virtual\environment

The command, if run with ‘-h’, will show the available options:

     usage: venv [-h] [--system-site-packages] [--symlinks | --copies] [--clear]
                 [--upgrade] [--without-pip] [--prompt PROMPT] [--upgrade-deps]
                 [--without-scm-ignore-files]
                 ENV_DIR [ENV_DIR ...]

     Creates virtual Python environments in one or more target directories.

     Once an environment has been created, you may wish to activate it, e.g. by
     sourcing an activate script in its bin directory.

 -- Option: ENV_DIR

     A required argument specifying the directory to create the
     environment in.

 -- Option: --system-site-packages

     Give the virtual environment access to the system site-packages
     directory.

 -- Option: --symlinks

     Try to use symlinks rather than copies, when symlinks are not the
     default for the platform.

 -- Option: --copies

     Try to use copies rather than symlinks, even when symlinks are the
     default for the platform.

 -- Option: --clear

     Delete the contents of the environment directory if it already
     exists, before environment creation.

 -- Option: --upgrade

     Upgrade the environment directory to use this version of Python,
     assuming Python has been upgraded in-place.

 -- Option: --without-pip

     Skips installing or upgrading pip in the virtual environment (pip
     is bootstrapped by default).

 -- Option: --prompt <PROMPT>

     Provides an alternative prompt prefix for this environment.

 -- Option: --upgrade-deps

     Upgrade core dependencies (pip) to the latest version in PyPI.

 -- Option: --without-scm-ignore-files

     Skips adding SCM ignore files to the environment directory (Git is
     supported by default).

Cambiato nella versione 3.4: Installs pip by default, added the
‘--without-pip’ and ‘--copies’ options.

Cambiato nella versione 3.4: In earlier versions, if the target
directory already existed, an error was raised, unless the ‘--clear’ or
‘--upgrade’ option was provided.

Cambiato nella versione 3.9: Add ‘--upgrade-deps’ option to upgrade pip
+ setuptools to the latest on PyPI.

Cambiato nella versione 3.12: ‘setuptools’ is no longer a core venv
dependency.

Cambiato nella versione 3.13: Added the ‘--without-scm-ignore-files’
option.

Cambiato nella versione 3.13: ‘venv’ now creates a ‘.gitignore’ file for
Git by default.

     Nota: While symlinks are supported on Windows, they are not
     recommended.  Of particular note is that double-clicking
     ‘python.exe’ in File Explorer will resolve the symlink eagerly and
     ignore the virtual environment.

     Nota: On Microsoft Windows, it may be required to enable the
     ‘Activate.ps1’ script by setting the execution policy for the user.
     You can do this by issuing the following PowerShell command:

          PS C:\> Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser

     See About Execution Policies(1) for more information.

The created ‘pyvenv.cfg’ file also includes the
‘include-system-site-packages’ key, set to ‘true’ if ‘venv’ is run with
the ‘--system-site-packages’ option, ‘false’ otherwise.

Unless the ‘--without-pip’ option is given, *note ensurepip: 59. will be
invoked to bootstrap ‘pip’ into the virtual environment.

Multiple paths can be given to ‘venv’, in which case an identical
virtual environment will be created, according to the given options, at
each provided path.

   ---------- Footnotes ----------

   (1) https://go.microsoft.com/fwlink/?LinkID=135170


File: python.info,  Node: How venvs work,  Next: API<2>,  Prev: Creating virtual environments,  Up: venv — Creation of virtual environments

5.28.2.2 How venvs work
.......................

When a Python interpreter is running from a virtual environment, *note
sys.prefix: 3e7. and *note sys.exec_prefix: 3eb. point to the
directories of the virtual environment, whereas *note sys.base_prefix:
3e6. and *note sys.base_exec_prefix: 3ea. point to those of the base
Python used to create the environment.  It is sufficient to check
‘sys.prefix != sys.base_prefix’ to determine if the current interpreter
is running from a virtual environment.

A virtual environment may be «activated» using a script in its binary
directory (‘bin’ on POSIX; ‘Scripts’ on Windows).  This will prepend
that directory to your ‘PATH’, so that running ‘python’ will invoke the
environment’s Python interpreter and you can run installed scripts
without having to use their full path.  The invocation of the activation
script is platform-specific (‘<VENV>’ must be replaced by the path to
the directory containing the virtual environment):

Platform          Shell            Command to activate virtual environment
                                   
------------------------------------------------------------------------------------------
                                   
POSIX             bash/zsh         ‘$ source <VENV>/bin/activate’
                                   
                  
fish              ‘$ source
                  <VENV>/bin/activate.fish’
                  
                  
csh/tcsh          ‘$ source
                  <VENV>/bin/activate.csh’
                  
                  
pwsh              ‘$
                  <VENV>/bin/Activate.ps1’
                  
                                   
Windows           cmd.exe          ‘C:\> <VENV>\Scripts\activate.bat’
                                   
                  
PowerShell        ‘PS C:\>
                  <VENV>\Scripts\Activate.ps1’
                  

Added in version 3.4: ‘fish’ and ‘csh’ activation scripts.

Added in version 3.8: PowerShell activation scripts installed under
POSIX for PowerShell Core support.

You don’t specifically 'need' to activate a virtual environment, as you
can just specify the full path to that environment’s Python interpreter
when invoking Python.  Furthermore, all scripts installed in the
environment should be runnable without activating it.

In order to achieve this, scripts installed into virtual environments
have a «shebang» line which points to the environment’s Python
interpreter, ‘#!/<PATH-TO-VENV>/bin/python’.  This means that the script
will run with that interpreter regardless of the value of ‘PATH’.  On
Windows, «shebang» line processing is supported if you have the *note
Python install manager: 7db. installed.  Thus, double-clicking an
installed script in a Windows Explorer window should run it with the
correct interpreter without the environment needing to be activated or
on the ‘PATH’.

When a virtual environment has been activated, the ‘VIRTUAL_ENV’
environment variable is set to the path of the environment.  Since
explicitly activating a virtual environment is not required to use it,
‘VIRTUAL_ENV’ cannot be relied upon to determine whether a virtual
environment is being used.

     Avvertimento: Because scripts installed in environments should not
     expect the environment to be activated, their shebang lines contain
     the absolute paths to their environment’s interpreters.  Because of
     this, environments are inherently non-portable, in the general
     case.  You should always have a simple means of recreating an
     environment (for example, if you have a requirements file
     ‘requirements.txt’, you can invoke ‘pip install -r
     requirements.txt’ using the environment’s ‘pip’ to install all of
     the packages needed by the environment).  If for any reason you
     need to move the environment to a new location, you should recreate
     it at the desired location and delete the one at the old location.
     If you move an environment because you moved a parent directory of
     it, you should recreate the environment in its new location.
     Otherwise, software installed into the environment may not work as
     expected.

You can deactivate a virtual environment by typing ‘deactivate’ in your
shell.  The exact mechanism is platform-specific and is an internal
implementation detail (typically, a script or shell function will be
used).


File: python.info,  Node: API<2>,  Next: An example of extending EnvBuilder,  Prev: How venvs work,  Up: venv — Creation of virtual environments

5.28.2.3 API
............

The high-level method described above makes use of a simple API which
provides mechanisms for third-party virtual environment creators to
customize environment creation according to their needs, the *note
EnvBuilder: 571. class.

 -- Classe: venv.EnvBuilder (system_site_packages=False, clear=False,
          symlinks=False, upgrade=False, with_pip=False, prompt=None,
          upgrade_deps=False, *, scm_ignore_files=frozenset())

     The *note EnvBuilder: 571. class accepts the following keyword
     arguments on instantiation:

        * 'system_site_packages' – a boolean value indicating that the
          system Python site-packages should be available to the
          environment (defaults to ‘False’).

        * 'clear' – a boolean value which, if true, will delete the
          contents of any existing target directory, before creating the
          environment.

        * 'symlinks' – a boolean value indicating whether to attempt to
          symlink the Python binary rather than copying.

        * 'upgrade' – a boolean value which, if true, will upgrade an
          existing environment with the running Python - for use when
          that Python has been upgraded in-place (defaults to ‘False’).

        * 'with_pip' – a boolean value which, if true, ensures pip is
          installed in the virtual environment.  This uses *note
          ensurepip: 59. with the ‘--default-pip’ option.

        * 'prompt' – a string to be used after virtual environment is
          activated (defaults to ‘None’ which means directory name of
          the environment would be used).  If the special string ‘"."’
          is provided, the basename of the current directory is used as
          the prompt.

        * 'upgrade_deps' – Update the base venv modules to the latest on
          PyPI

        * 'scm_ignore_files' – Create ignore files based for the
          specified source control managers (SCM) in the iterable.
          Support is defined by having a method named
          ‘create_{scm}_ignore_file’.  The only value supported by
          default is ‘"git"’ via *note create_git_ignore_file(): 48ab.

     Cambiato nella versione 3.4: Added the ‘with_pip’ parameter

     Cambiato nella versione 3.6: Added the ‘prompt’ parameter

     Cambiato nella versione 3.9: Added the ‘upgrade_deps’ parameter

     Cambiato nella versione 3.13: Added the ‘scm_ignore_files’
     parameter

     *note EnvBuilder: 571. may be used as a base class.

      -- Metodo: create (env_dir)

          Create a virtual environment by specifying the target
          directory (absolute or relative to the current directory)
          which is to contain the virtual environment.  The ‘create’
          method will either create the environment in the specified
          directory, or raise an appropriate exception.

          The ‘create’ method of the *note EnvBuilder: 571. class
          illustrates the hooks available for subclass customization:

               def create(self, env_dir):
                   """
                   Create a virtualized Python environment in a directory.
                   env_dir is the target directory to create an environment in.
                   """
                   env_dir = os.path.abspath(env_dir)
                   context = self.ensure_directories(env_dir)
                   self.create_configuration(context)
                   self.setup_python(context)
                   self.setup_scripts(context)
                   self.post_setup(context)

          Each of the methods *note ensure_directories(): 48ad, *note
          create_configuration(): 48ae, *note setup_python(): 48af,
          *note setup_scripts(): 48b0. and *note post_setup(): 48b1. can
          be overridden.

      -- Metodo: ensure_directories (env_dir)

          Creates the environment directory and all necessary
          subdirectories that don’t already exist, and returns a context
          object.  This context object is just a holder for attributes
          (such as paths) for use by the other methods.  If the *note
          EnvBuilder: 571. is created with the arg ‘clear=True’,
          contents of the environment directory will be cleared and then
          all necessary subdirectories will be recreated.

          The returned context object is a *note types.SimpleNamespace:
          4e6. with the following attributes:

             * ‘env_dir’ - The location of the virtual environment.
               Used for ‘__VENV_DIR__’ in activation scripts (see *note
               install_scripts(): 48b2.).

             * ‘env_name’ - The name of the virtual environment.  Used
               for ‘__VENV_NAME__’ in activation scripts (see *note
               install_scripts(): 48b2.).

             * ‘prompt’ - The prompt to be used by the activation
               scripts.  Used for ‘__VENV_PROMPT__’ in activation
               scripts (see *note install_scripts(): 48b2.).

             * ‘executable’ - The underlying Python executable used by
               the virtual environment.  This takes into account the
               case where a virtual environment is created from another
               virtual environment.

             * ‘inc_path’ - The include path for the virtual
               environment.

             * ‘lib_path’ - The purelib path for the virtual
               environment.

             * ‘bin_path’ - The script path for the virtual environment.

             * ‘bin_name’ - The name of the script path relative to the
               virtual environment location.  Used for
               ‘__VENV_BIN_NAME__’ in activation scripts (see *note
               install_scripts(): 48b2.).

             * ‘env_exe’ - The name of the Python interpreter in the
               virtual environment.  Used for ‘__VENV_PYTHON__’ in
               activation scripts (see *note install_scripts(): 48b2.).

             * ‘env_exec_cmd’ - The name of the Python interpreter,
               taking into account filesystem redirections.  This can be
               used to run Python in the virtual environment.

          Cambiato nella versione 3.11: The 'venv' *note sysconfig
          installation scheme: 449. is used to construct the paths of
          the created directories.

          Cambiato nella versione 3.12: The attribute ‘lib_path’ was
          added to the context, and the context object was documented.

      -- Metodo: create_configuration (context)

          Creates the ‘pyvenv.cfg’ configuration file in the
          environment.

      -- Metodo: setup_python (context)

          Creates a copy or symlink to the Python executable in the
          environment.  On POSIX systems, if a specific executable
          ‘python3.x’ was used, symlinks to ‘python’ and ‘python3’ will
          be created pointing to that executable, unless files with
          those names already exist.

      -- Metodo: setup_scripts (context)

          Installs activation scripts appropriate to the platform into
          the virtual environment.

      -- Metodo: upgrade_dependencies (context)

          Upgrades the core venv dependency packages (currently pip(1))
          in the environment.  This is done by shelling out to the ‘pip’
          executable in the environment.

          Added in version 3.9.

          Cambiato nella versione 3.12: setuptools(2) is no longer a
          core venv dependency.

      -- Metodo: post_setup (context)

          A placeholder method which can be overridden in third party
          implementations to pre-install packages in the virtual
          environment or perform other post-creation steps.

      -- Metodo: install_scripts (context, path)

          This method can be called from *note setup_scripts(): 48b0. or
          *note post_setup(): 48b1. in subclasses to assist in
          installing custom scripts into the virtual environment.

          'path' is the path to a directory that should contain
          subdirectories ‘common’, ‘posix’, ‘nt’; each containing
          scripts destined for the ‘bin’ directory in the environment.
          The contents of ‘common’ and the directory corresponding to
          *note os.name: 2fe8. are copied after some text replacement of
          placeholders:

             * ‘__VENV_DIR__’ is replaced with the absolute path of the
               environment directory.

             * ‘__VENV_NAME__’ is replaced with the environment name
               (final path segment of environment directory).

             * ‘__VENV_PROMPT__’ is replaced with the prompt (the
               environment name surrounded by parentheses and with a
               following space)

             * ‘__VENV_BIN_NAME__’ is replaced with the name of the bin
               directory (either ‘bin’ or ‘Scripts’).

             * ‘__VENV_PYTHON__’ is replaced with the absolute path of
               the environment’s executable.

          The directories are allowed to exist (for when an existing
          environment is being upgraded).

      -- Metodo: create_git_ignore_file (context)

          Creates a ‘.gitignore’ file within the virtual environment
          that causes the entire directory to be ignored by the Git
          source control manager.

          Added in version 3.13.

     Cambiato nella versione 3.7.2: Windows now uses redirector scripts
     for ‘python[w].exe’ instead of copying the actual binaries.  In
     3.7.2 only *note setup_python(): 48af. does nothing unless running
     from a build in the source tree.

     Cambiato nella versione 3.7.3: Windows copies the redirector
     scripts as part of *note setup_python(): 48af. instead of *note
     setup_scripts(): 48b0.  This was not the case in 3.7.2.  When using
     symlinks, the original executables will be linked.

There is also a module-level convenience function:

 -- Funzione: venv.create (env_dir, system_site_packages=False,
          clear=False, symlinks=False, with_pip=False, prompt=None,
          upgrade_deps=False, *, scm_ignore_files=frozenset())

     Create an *note EnvBuilder: 571. with the given keyword arguments,
     and call its *note create(): 48ac. method with the 'env_dir'
     argument.

     Added in version 3.3.

     Cambiato nella versione 3.4: Added the 'with_pip' parameter

     Cambiato nella versione 3.6: Added the 'prompt' parameter

     Cambiato nella versione 3.9: Added the 'upgrade_deps' parameter

     Cambiato nella versione 3.13: Added the 'scm_ignore_files'
     parameter

   ---------- Footnotes ----------

   (1) https://pypi.org/project/pip/

   (2) https://pypi.org/project/setuptools/


File: python.info,  Node: An example of extending EnvBuilder,  Prev: API<2>,  Up: venv — Creation of virtual environments

5.28.2.4 An example of extending ‘EnvBuilder’
.............................................

The following script shows how to extend *note EnvBuilder: 571. by
implementing a subclass which installs setuptools and pip into a created
virtual environment:

     import os
     import os.path
     from subprocess import Popen, PIPE
     import sys
     from threading import Thread
     from urllib.parse import urlparse
     from urllib.request import urlretrieve
     import venv

     class ExtendedEnvBuilder(venv.EnvBuilder):
         """
         This builder installs setuptools and pip so that you can pip or
         easy_install other packages into the created virtual environment.

         :param nodist: If true, setuptools and pip are not installed into the
                        created virtual environment.
         :param nopip: If true, pip is not installed into the created
                       virtual environment.
         :param progress: If setuptools or pip are installed, the progress of the
                          installation can be monitored by passing a progress
                          callable. If specified, it is called with two
                          arguments: a string indicating some progress, and a
                          context indicating where the string is coming from.
                          The context argument can have one of three values:
                          'main', indicating that it is called from virtualize()
                          itself, and 'stdout' and 'stderr', which are obtained
                          by reading lines from the output streams of a subprocess
                          which is used to install the app.

                          If a callable is not specified, default progress
                          information is output to sys.stderr.
         """

         def __init__(self, *args, **kwargs):
             self.nodist = kwargs.pop('nodist', False)
             self.nopip = kwargs.pop('nopip', False)
             self.progress = kwargs.pop('progress', None)
             self.verbose = kwargs.pop('verbose', False)
             super().__init__(*args, **kwargs)

         def post_setup(self, context):
             """
             Set up any packages which need to be pre-installed into the
             virtual environment being created.

             :param context: The information for the virtual environment
                             creation request being processed.
             """
             os.environ['VIRTUAL_ENV'] = context.env_dir
             if not self.nodist:
                 self.install_setuptools(context)
             # Can't install pip without setuptools
             if not self.nopip and not self.nodist:
                 self.install_pip(context)

         def reader(self, stream, context):
             """
             Read lines from a subprocess' output stream and either pass to a progress
             callable (if specified) or write progress information to sys.stderr.
             """
             progress = self.progress
             while True:
                 s = stream.readline()
                 if not s:
                     break
                 if progress is not None:
                     progress(s, context)
                 else:
                     if not self.verbose:
                         sys.stderr.write('.')
                     else:
                         sys.stderr.write(s.decode('utf-8'))
                     sys.stderr.flush()
             stream.close()

         def install_script(self, context, name, url):
             _, _, path, _, _, _ = urlparse(url)
             fn = os.path.split(path)[-1]
             binpath = context.bin_path
             distpath = os.path.join(binpath, fn)
             # Download script into the virtual environment's binaries folder
             urlretrieve(url, distpath)
             progress = self.progress
             if self.verbose:
                 term = '\n'
             else:
                 term = ''
             if progress is not None:
                 progress('Installing %s ...%s' % (name, term), 'main')
             else:
                 sys.stderr.write('Installing %s ...%s' % (name, term))
                 sys.stderr.flush()
             # Install in the virtual environment
             args = [context.env_exe, fn]
             p = Popen(args, stdout=PIPE, stderr=PIPE, cwd=binpath)
             t1 = Thread(target=self.reader, args=(p.stdout, 'stdout'))
             t1.start()
             t2 = Thread(target=self.reader, args=(p.stderr, 'stderr'))
             t2.start()
             p.wait()
             t1.join()
             t2.join()
             if progress is not None:
                 progress('done.', 'main')
             else:
                 sys.stderr.write('done.\n')
             # Clean up - no longer needed
             os.unlink(distpath)

         def install_setuptools(self, context):
             """
             Install setuptools in the virtual environment.

             :param context: The information for the virtual environment
                             creation request being processed.
             """
             url = "https://bootstrap.pypa.io/ez_setup.py"
             self.install_script(context, 'setuptools', url)
             # clear up the setuptools archive which gets downloaded
             pred = lambda o: o.startswith('setuptools-') and o.endswith('.tar.gz')
             files = filter(pred, os.listdir(context.bin_path))
             for f in files:
                 f = os.path.join(context.bin_path, f)
                 os.unlink(f)

         def install_pip(self, context):
             """
             Install pip in the virtual environment.

             :param context: The information for the virtual environment
                             creation request being processed.
             """
             url = 'https://bootstrap.pypa.io/get-pip.py'
             self.install_script(context, 'pip', url)


     def main(args=None):
         import argparse

         parser = argparse.ArgumentParser(prog=__name__,
                                          description='Creates virtual Python '
                                                      'environments in one or '
                                                      'more target '
                                                      'directories.')
         parser.add_argument('dirs', metavar='ENV_DIR', nargs='+',
                             help='A directory in which to create the '
                                  'virtual environment.')
         parser.add_argument('--no-setuptools', default=False,
                             action='store_true', dest='nodist',
                             help="Don't install setuptools or pip in the "
                                  "virtual environment.")
         parser.add_argument('--no-pip', default=False,
                             action='store_true', dest='nopip',
                             help="Don't install pip in the virtual "
                                  "environment.")
         parser.add_argument('--system-site-packages', default=False,
                             action='store_true', dest='system_site',
                             help='Give the virtual environment access to the '
                                  'system site-packages dir.')
         if os.name == 'nt':
             use_symlinks = False
         else:
             use_symlinks = True
         parser.add_argument('--symlinks', default=use_symlinks,
                             action='store_true', dest='symlinks',
                             help='Try to use symlinks rather than copies, '
                                  'when symlinks are not the default for '
                                  'the platform.')
         parser.add_argument('--clear', default=False, action='store_true',
                             dest='clear', help='Delete the contents of the '
                                                'virtual environment '
                                                'directory if it already '
                                                'exists, before virtual '
                                                'environment creation.')
         parser.add_argument('--upgrade', default=False, action='store_true',
                             dest='upgrade', help='Upgrade the virtual '
                                                  'environment directory to '
                                                  'use this version of '
                                                  'Python, assuming Python '
                                                  'has been upgraded '
                                                  'in-place.')
         parser.add_argument('--verbose', default=False, action='store_true',
                             dest='verbose', help='Display the output '
                                                  'from the scripts which '
                                                  'install setuptools and pip.')
         options = parser.parse_args(args)
         if options.upgrade and options.clear:
             raise ValueError('you cannot supply --upgrade and --clear together.')
         builder = ExtendedEnvBuilder(system_site_packages=options.system_site,
                                        clear=options.clear,
                                        symlinks=options.symlinks,
                                        upgrade=options.upgrade,
                                        nodist=options.nodist,
                                        nopip=options.nopip,
                                        verbose=options.verbose)
         for d in options.dirs:
             builder.create(d)

     if __name__ == '__main__':
         rc = 1
         try:
             main()
             rc = 0
         except Exception as e:
             print('Error: %s' % e, file=sys.stderr)
         sys.exit(rc)

This script is also available for download online(1).

   ---------- Footnotes ----------

   (1) https://gist.github.com/vsajip/4673395


File: python.info,  Node: zipapp — Manage executable Python zip archives,  Prev: venv — Creation of virtual environments,  Up: Software Packaging and Distribution

5.28.3 ‘zipapp’ — Manage executable Python zip archives
-------------------------------------------------------

Added in version 3.5.

'Source code:' Lib/zipapp.py(1)

__________________________________________________________________

This module provides tools to manage the creation of zip files
containing Python code, which can be *note executed directly by the
Python interpreter: 2104.  The module provides both a *note Command-Line
Interface: 48b8. and a *note Python API: 48b9.

* Menu:

* Basic Example::
* Command-Line Interface: Command-Line Interface<4>.
* Python API::
* Examples: Examples<33>.
* Specifying the Interpreter::
* Creating Standalone Applications with zipapp::
* The Python Zip Application Archive Format::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/zipapp.py


File: python.info,  Node: Basic Example,  Next: Command-Line Interface<4>,  Up: zipapp — Manage executable Python zip archives

5.28.3.1 Basic Example
......................

The following example shows how the *note Command-Line Interface: 48b8.
can be used to create an executable archive from a directory containing
Python code.  When run, the archive will execute the ‘main’ function
from the module ‘myapp’ in the archive.

     $ python -m zipapp myapp -m "myapp:main"
     $ python myapp.pyz
     <output from myapp>


File: python.info,  Node: Command-Line Interface<4>,  Next: Python API,  Prev: Basic Example,  Up: zipapp — Manage executable Python zip archives

5.28.3.2 Command-Line Interface
...............................

When called as a program from the command line, the following form is
used:

     $ python -m zipapp source [options]

If 'source' is a directory, this will create an archive from the
contents of 'source'.  If 'source' is a file, it should be an archive,
and it will be copied to the target archive (or the contents of its
shebang line will be displayed if the –info option is specified).

The following options are understood:

 -- Option: -o <output>, --output=<output>

     Write the output to a file named 'output'.  If this option is not
     specified, the output filename will be the same as the input
     'source', with the extension ‘.pyz’ added.  If an explicit filename
     is given, it is used as is (so a ‘.pyz’ extension should be
     included if required).

     An output filename must be specified if the 'source' is an archive
     (and in that case, 'output' must not be the same as 'source').

 -- Option: -p <interpreter>, --python=<interpreter>

     Add a ‘#!’ line to the archive specifying 'interpreter' as the
     command to run.  Also, on POSIX, make the archive executable.  The
     default is to write no ‘#!’ line, and not make the file executable.

 -- Option: -m <mainfn>, --main=<mainfn>

     Write a ‘__main__.py’ file to the archive that executes 'mainfn'.
     The 'mainfn' argument should have the form «pkg.mod:fn», where
     «pkg.mod» is a package/module in the archive, and «fn» is a
     callable in the given module.  The ‘__main__.py’ file will execute
     that callable.

     *note -main: 48c0. cannot be specified when copying an archive.

 -- Option: -c, --compress

     Compress files with the deflate method, reducing the size of the
     output file.  By default, files are stored uncompressed in the
     archive.

     *note -compress: 48c2. has no effect when copying an archive.

     Added in version 3.7.

 -- Option: --info

     Display the interpreter embedded in the archive, for diagnostic
     purposes.  In this case, any other options are ignored and SOURCE
     must be an archive, not a directory.

 -- Option: -h, --help

     Print a short usage message and exit.


File: python.info,  Node: Python API,  Next: Examples<33>,  Prev: Command-Line Interface<4>,  Up: zipapp — Manage executable Python zip archives

5.28.3.3 Python API
...................

The module defines two convenience functions:

 -- Funzione: zipapp.create_archive (source, target=None,
          interpreter=None, main=None, filter=None, compressed=False)

     Create an application archive from 'source'.  The source can be any
     of the following:

        * The name of a directory, or a *note path-like object: 5a1.
          referring to a directory, in which case a new application
          archive will be created from the content of that directory.

        * The name of an existing application archive file, or a *note
          path-like object: 5a1. referring to such a file, in which case
          the file is copied to the target (modifying it to reflect the
          value given for the 'interpreter' argument).  The file name
          should include the ‘.pyz’ extension, if required.

        * A file object open for reading in bytes mode.  The content of
          the file should be an application archive, and the file object
          is assumed to be positioned at the start of the archive.

     The 'target' argument determines where the resulting archive will
     be written:

        * If it is the name of a file, or a *note path-like object: 5a1,
          the archive will be written to that file.

        * If it is an open file object, the archive will be written to
          that file object, which must be open for writing in bytes
          mode.

        * If the target is omitted (or ‘None’), the source must be a
          directory and the target will be a file with the same name as
          the source, with a ‘.pyz’ extension added.

     The 'interpreter' argument specifies the name of the Python
     interpreter with which the archive will be executed.  It is written
     as a «shebang» line at the start of the archive.  On POSIX, this
     will be interpreted by the OS, and on Windows it will be handled by
     the Python launcher.  Omitting the 'interpreter' results in no
     shebang line being written.  If an interpreter is specified, and
     the target is a filename, the executable bit of the target file
     will be set.

     The 'main' argument specifies the name of a callable which will be
     used as the main program for the archive.  It can only be specified
     if the source is a directory, and the source does not already
     contain a ‘__main__.py’ file.  The 'main' argument should take the
     form «pkg.module:callable» and the archive will be run by importing
     «pkg.module» and executing the given callable with no arguments.
     It is an error to omit 'main' if the source is a directory and does
     not contain a ‘__main__.py’ file, as otherwise the resulting
     archive would not be executable.

     The optional 'filter' argument specifies a callback function that
     is passed a Path object representing the path to the file being
     added (relative to the source directory).  It should return ‘True’
     if the file is to be added.

     The optional 'compressed' argument determines whether files are
     compressed.  If set to ‘True’, files in the archive are compressed
     with the deflate method; otherwise, files are stored uncompressed.
     This argument has no effect when copying an existing archive.

     If a file object is specified for 'source' or 'target', it is the
     caller’s responsibility to close it after calling create_archive.

     When copying an existing archive, file objects supplied only need
     ‘read’ and ‘readline’, or ‘write’ methods.  When creating an
     archive from a directory, if the target is a file object it will be
     passed to the ‘zipfile.ZipFile’ class, and must supply the methods
     needed by that class.

     Cambiato nella versione 3.7: Added the 'filter' and 'compressed'
     parameters.

 -- Funzione: zipapp.get_interpreter (archive)

     Return the interpreter specified in the ‘#!’ line at the start of
     the archive.  If there is no ‘#!’ line, return *note None: 886.
     The 'archive' argument can be a filename or a file-like object open
     for reading in bytes mode.  It is assumed to be at the start of the
     archive.


File: python.info,  Node: Examples<33>,  Next: Specifying the Interpreter,  Prev: Python API,  Up: zipapp — Manage executable Python zip archives

5.28.3.4 Examples
.................

Pack up a directory into an archive, and run it.

     $ python -m zipapp myapp
     $ python myapp.pyz
     <output from myapp>

The same can be done using the *note create_archive(): dab. function:

     >>> import zipapp
     >>> zipapp.create_archive('myapp', 'myapp.pyz')

To make the application directly executable on POSIX, specify an
interpreter to use.

     $ python -m zipapp myapp -p "/usr/bin/env python"
     $ ./myapp.pyz
     <output from myapp>

To replace the shebang line on an existing archive, create a modified
archive using the *note create_archive(): dab. function:

     >>> import zipapp
     >>> zipapp.create_archive('old_archive.pyz', 'new_archive.pyz', '/usr/bin/python3')

To update the file in place, do the replacement in memory using a *note
BytesIO: 10a6. object, and then overwrite the source afterwards.  Note
that there is a risk when overwriting a file in place that an error will
result in the loss of the original file.  This code does not protect
against such errors, but production code should do so.  Also, this
method will only work if the archive fits in memory:

     >>> import zipapp
     >>> import io
     >>> temp = io.BytesIO()
     >>> zipapp.create_archive('myapp.pyz', temp, '/usr/bin/python2')
     >>> with open('myapp.pyz', 'wb') as f:
     >>>     f.write(temp.getvalue())


File: python.info,  Node: Specifying the Interpreter,  Next: Creating Standalone Applications with zipapp,  Prev: Examples<33>,  Up: zipapp — Manage executable Python zip archives

5.28.3.5 Specifying the Interpreter
...................................

Note that if you specify an interpreter and then distribute your
application archive, you need to ensure that the interpreter used is
portable.  The Python launcher for Windows supports most common forms of
POSIX ‘#!’ line, but there are other issues to consider:

   * If you use «/usr/bin/env python» (or other forms of the «python»
     command, such as «/usr/bin/python»), you need to consider that your
     users may have either Python 2 or Python 3 as their default, and
     write your code to work under both versions.

   * If you use an explicit version, for example «/usr/bin/env python3»
     your application will not work for users who do not have that
     version.  (This may be what you want if you have not made your code
     Python 2 compatible).

   * There is no way to say «python X.Y or later», so be careful of
     using an exact version like «/usr/bin/env python3.4» as you will
     need to change your shebang line for users of Python 3.5, for
     example.

Typically, you should use an «/usr/bin/env python2» or «/usr/bin/env
python3», depending on whether your code is written for Python 2 or 3.


File: python.info,  Node: Creating Standalone Applications with zipapp,  Next: The Python Zip Application Archive Format,  Prev: Specifying the Interpreter,  Up: zipapp — Manage executable Python zip archives

5.28.3.6 Creating Standalone Applications with zipapp
.....................................................

Using the *note zipapp: 136. module, it is possible to create
self-contained Python programs, which can be distributed to end users
who only need to have a suitable version of Python installed on their
system.  The key to doing this is to bundle all of the application’s
dependencies into the archive, along with the application code.

The steps to create a standalone archive are as follows:

  1. Create your application in a directory as normal, so you have a
     ‘myapp’ directory containing a ‘__main__.py’ file, and any
     supporting application code.

  2. Install all of your application’s dependencies into the ‘myapp’
     directory, using pip:

          $ python -m pip install -r requirements.txt --target myapp

     (this assumes you have your project requirements in a
     ‘requirements.txt’ file - if not, you can just list the
     dependencies manually on the pip command line).

  3. Package the application using:

          $ python -m zipapp -p "interpreter" myapp

This will produce a standalone executable, which can be run on any
machine with the appropriate interpreter available.  See *note
Specifying the Interpreter: 48cc. for details.  It can be shipped to
users as a single file.

On Unix, the ‘myapp.pyz’ file is executable as it stands.  You can
rename the file to remove the ‘.pyz’ extension if you prefer a «plain»
command name.  On Windows, the ‘myapp.pyz[w]’ file is executable by
virtue of the fact that the Python interpreter registers the ‘.pyz’ and
‘.pyzw’ file extensions when installed.

* Menu:

* Caveats::


File: python.info,  Node: Caveats,  Up: Creating Standalone Applications with zipapp

5.28.3.7 Caveats
................

If your application depends on a package that includes a C extension,
that package cannot be run from a zip file (this is an OS limitation, as
executable code must be present in the filesystem for the OS loader to
load it).  In this case, you can exclude that dependency from the
zipfile, and either require your users to have it installed, or ship it
alongside your zipfile and add code to your ‘__main__.py’ to include the
directory containing the unzipped module in ‘sys.path’.  In this case,
you will need to make sure to ship appropriate binaries for your target
architecture(s) (and potentially pick the correct version to add to
‘sys.path’ at runtime, based on the user’s machine).


File: python.info,  Node: The Python Zip Application Archive Format,  Prev: Creating Standalone Applications with zipapp,  Up: zipapp — Manage executable Python zip archives

5.28.3.8 The Python Zip Application Archive Format
..................................................

Python has been able to execute zip files which contain a ‘__main__.py’
file since version 2.6.  In order to be executed by Python, an
application archive simply has to be a standard zip file containing a
‘__main__.py’ file which will be run as the entry point for the
application.  As usual for any Python script, the parent of the script
(in this case the zip file) will be placed on *note sys.path: 3e4. and
thus further modules can be imported from the zip file.

The zip file format allows arbitrary data to be prepended to a zip file.
The zip application format uses this ability to prepend a standard POSIX
«shebang» line to the file (‘#!/path/to/interpreter’).

Formally, the Python zip application format is therefore:

  1. An optional shebang line, containing the characters ‘b'#!'’
     followed by an interpreter name, and then a newline (‘b'\n'’)
     character.  The interpreter name can be anything acceptable to the
     OS «shebang» processing, or the Python launcher on Windows.  The
     interpreter should be encoded in UTF-8 on Windows, and in *note
     sys.getfilesystemencoding(): e55. on POSIX.

  2. Standard zipfile data, as generated by the *note zipfile: 137.
     module.  The zipfile content 'must' include a file called
     ‘__main__.py’ (which must be in the «root» of the zipfile - i.e.,
     it cannot be in a subdirectory).  The zipfile data can be
     compressed or uncompressed.

If an application archive has a shebang line, it may have the executable
bit set on POSIX systems, to allow it to be executed directly.

There is no requirement that the tools in this module are used to create
application archives - the module is a convenience, but archives in the
above format created by any means are acceptable to Python.


File: python.info,  Node: Python Runtime Services,  Next: Custom Python Interpreters,  Prev: Software Packaging and Distribution,  Up: The Python Standard Library

5.29 Python Runtime Services
============================

The modules described in this chapter provide a wide range of services
related to the Python interpreter and its interaction with its
environment.  Here’s an overview:

* Menu:

* sys — System-specific parameters and functions::
* sys.monitoring — Execution event monitoring: sys monitoring — Execution event monitoring.
* sysconfig — Provide access to Python’s configuration information::
* builtins — Built-in objects::
* __main__ — Top-level code environment::
* warnings — Warning control::
* dataclasses — Data Classes::
* contextlib — Utilities for with-statement contexts::
* abc — Abstract Base Classes::
* atexit — Exit handlers::
* traceback — Print or retrieve a stack traceback::
* __future__ — Future statement definitions::
* gc — Garbage Collector interface::
* inspect — Inspect live objects::
* annotationlib — Functionality for introspecting annotations::
* site — Site-specific configuration hook::


File: python.info,  Node: sys — System-specific parameters and functions,  Next: sys monitoring — Execution event monitoring,  Up: Python Runtime Services

5.29.1 ‘sys’ — System-specific parameters and functions
-------------------------------------------------------

__________________________________________________________________

This module provides access to some variables used or maintained by the
interpreter and to functions that interact strongly with the
interpreter.  It is always available.  Unless explicitly noted
otherwise, all variables are read-only.

 -- Dati: sys.abiflags

     On POSIX systems where Python was built with the standard
     ‘configure’ script, this contains the ABI flags as specified by PEP
     3149(1).

     Added in version 3.2.

     Cambiato nella versione 3.8: Default flags became an empty string
     (‘m’ flag for pymalloc has been removed).

     *note Availability: 2128.: Unix.

 -- Funzione: sys.addaudithook (hook)

     Append the callable 'hook' to the list of active auditing hooks for
     the current (sub)interpreter.

     When an auditing event is raised through the *note sys.audit():
     1903. function, each hook will be called in the order it was added
     with the event name and the tuple of arguments.  Native hooks added
     by *note PySys_AddAuditHook(): 4739. are called first, followed by
     hooks added in the current (sub)interpreter.  Hooks can then log
     the event, raise an exception to abort the operation, or terminate
     the process entirely.

     Note that audit hooks are primarily for collecting information
     about internal or otherwise unobservable actions, whether by Python
     or libraries written in Python.  They are not suitable for
     implementing a «sandbox».  In particular, malicious code can
     trivially disable or bypass hooks added using this function.  At a
     minimum, any security-sensitive hooks must be added using the C API
     *note PySys_AddAuditHook(): 4739. before initialising the runtime,
     and any modules allowing arbitrary memory modification (such as
     *note ctypes: 2e.) should be completely removed or closely
     monitored.

     Calling *note sys.addaudithook(): 4738. will itself raise an
     auditing event named ‘sys.addaudithook’ with no arguments.  If any
     existing hooks raise an exception derived from *note RuntimeError:
     244, the new hook will not be added and the exception suppressed.
     As a result, callers cannot assume that their hook has been added
     unless they control all existing hooks.

     See the *note audit events table: 1bfb. for all events raised by
     CPython, and PEP 578(2) for the original design discussion.

     Added in version 3.8.

     Cambiato nella versione 3.8.1: Exceptions derived from *note
     Exception: bcf. but not *note RuntimeError: 244. are no longer
     suppressed.

     'Dettaglio dell’implementazione di CPython:' When tracing is
     enabled (see *note settrace(): 2e1.), Python hooks are only traced
     if the callable has a ‘__cantrace__’ member that is set to a true
     value.  Otherwise, trace functions will skip the hook.

 -- Dati: sys.argv

     The list of command line arguments passed to a Python script.
     ‘argv[0]’ is the script name (it is operating system dependent
     whether this is a full pathname or not).  If the command was
     executed using the *note -c: 1a8. command line option to the
     interpreter, ‘argv[0]’ is set to the string ‘'-c'’.  If no script
     name was passed to the Python interpreter, ‘argv[0]’ is the empty
     string.

     To loop over the standard input, or the list of files given on the
     command line, see the *note fileinput: 5f. module.

     See also *note sys.orig_argv: a43.

          Nota: On Unix, command line arguments are passed by bytes from
          OS. Python decodes them with filesystem encoding and
          «surrogateescape» error handler.  When you need original
          bytes, you can get it by ‘[os.fsencode(arg) for arg in
          sys.argv]’.

 -- Funzione: sys.audit (event, *args)

     Raise an auditing event and trigger any active auditing hooks.
     'event' is a string identifying the event, and 'args' may contain
     optional arguments with more information about the event.  The
     number and types of arguments for a given event are considered a
     public and stable API and should not be modified between releases.

     For example, one auditing event is named ‘os.chdir’.  This event
     has one argument called 'path' that will contain the requested new
     working directory.

     *note sys.audit(): 1903. will call the existing auditing hooks,
     passing the event name and arguments, and will re-raise the first
     exception from any hook.  In general, if an exception is raised, it
     should not be handled and the process should be terminated as
     quickly as possible.  This allows hook implementations to decide
     how to respond to particular events: they can merely log the event
     or abort the operation by raising an exception.

     Hooks are added using the *note sys.addaudithook(): 4738. or *note
     PySys_AddAuditHook(): 4739. functions.

     The native equivalent of this function is *note PySys_Audit(): 613.
     Using the native function is preferred when possible.

     See the *note audit events table: 1bfb. for all events raised by
     CPython.

     Added in version 3.8.

 -- Dati: sys.base_exec_prefix

     Equivalent to *note exec_prefix: 3eb, but referring to the base
     Python installation.

     When running under *note Virtual Environments: 489b, *note
     exec_prefix: 3eb. gets overwritten to the virtual environment
     prefix.  *note base_exec_prefix: 3ea, conversely, does not change,
     and always points to the base Python installation.  Refer to *note
     Virtual Environments: 489b. for more information.

     Added in version 3.3.

 -- Dati: sys.base_prefix

     Equivalent to *note prefix: 3e7, but referring to the base Python
     installation.

     When running under *note virtual environment: 3e8, *note prefix:
     3e7. gets overwritten to the virtual environment prefix.  *note
     base_prefix: 3e6, conversely, does not change, and always points to
     the base Python installation.  Refer to *note Virtual Environments:
     489b. for more information.

     Added in version 3.3.

 -- Dati: sys.byteorder

     An indicator of the native byte order.  This will have the value
     ‘'big'’ on big-endian (most-significant byte first) platforms, and
     ‘'little'’ on little-endian (least-significant byte first)
     platforms.

 -- Dati: sys.builtin_module_names

     A tuple of strings containing the names of all modules that are
     compiled into this Python interpreter.  (This information is not
     available in any other way — ‘modules.keys()’ only lists the
     imported modules.)

     See also the *note sys.stdlib_module_names: a44. list.

 -- Funzione: sys.call_tracing (func, args)

     Call ‘func(*args)’, while tracing is enabled.  The tracing state is
     saved, and restored afterwards.  This is intended to be called from
     a debugger from a checkpoint, to recursively debug or profile some
     other code.

     Tracing is suspended while calling a tracing function set by *note
     settrace(): 2e1. or *note setprofile(): 1705. to avoid infinite
     recursion.  ‘call_tracing()’ enables explicit recursion of the
     tracing function.

 -- Dati: sys.copyright

     A string containing the copyright pertaining to the Python
     interpreter.

 -- Funzione: sys._clear_type_cache ()

     Clear the internal type cache.  The type cache is used to speed up
     attribute and method lookups.  Use the function 'only' to drop
     unnecessary references during reference leak debugging.

     This function should be used for internal and specialized purposes
     only.

     Deprecato dalla versione 3.13: Use the more general *note
     _clear_internal_caches(): 364. function instead.

 -- Funzione: sys._clear_internal_caches ()

     Clear all internal performance-related caches.  Use this function
     'only' to release unnecessary references and memory blocks when
     hunting for leaks.

     Added in version 3.13.

 -- Funzione: sys._current_frames ()

     Return a dictionary mapping each thread’s identifier to the topmost
     stack frame currently active in that thread at the time the
     function is called.  Note that functions in the *note traceback:
     104. module can build the call stack given such a frame.

     This is most useful for debugging deadlock: this function does not
     require the deadlocked threads” cooperation, and such threads” call
     stacks are frozen for as long as they remain deadlocked.  The frame
     returned for a non-deadlocked thread may bear no relationship to
     that thread’s current activity by the time calling code examines
     the frame.

     This function should be used for internal and specialized purposes
     only.

     Raises an *note auditing event: 1c56. ‘sys._current_frames’ with no
     arguments.

 -- Funzione: sys._current_exceptions ()

     Return a dictionary mapping each thread’s identifier to the topmost
     exception currently active in that thread at the time the function
     is called.  If a thread is not currently handling an exception, it
     is not included in the result dictionary.

     This is most useful for statistical profiling.

     This function should be used for internal and specialized purposes
     only.

     Raises an *note auditing event: 1c56. ‘sys._current_exceptions’
     with no arguments.

     Cambiato nella versione 3.12: Each value in the dictionary is now a
     single exception instance, rather than a 3-tuple as returned from
     ‘sys.exc_info()’.

 -- Funzione: sys.breakpointhook ()

     This hook function is called by built-in *note breakpoint(): 271.
     By default, it drops you into the *note pdb: aa. debugger, but it
     can be set to any other function so that you can choose which
     debugger gets used.

     The signature of this function is dependent on what it calls.  For
     example, the default binding (e.g.  ‘pdb.set_trace()’) expects no
     arguments, but you might bind it to a function that expects
     additional arguments (positional and/or keyword).  The built-in
     ‘breakpoint()’ function passes its ‘*args’ and ‘**kws’ straight
     through.  Whatever ‘breakpointhooks()’ returns is returned from
     ‘breakpoint()’.

     The default implementation first consults the environment variable
     *note PYTHONBREAKPOINT: cd4.  If that is set to ‘"0"’ then this
     function returns immediately; i.e.  it is a no-op.  If the
     environment variable is not set, or is set to the empty string,
     ‘pdb.set_trace()’ is called.  Otherwise this variable should name a
     function to run, using Python’s dotted-import nomenclature, e.g.
     ‘package.subpackage.module.function’.  In this case,
     ‘package.subpackage.module’ would be imported and the resulting
     module must have a callable named ‘function()’.  This is run,
     passing in ‘*args’ and ‘**kws’, and whatever ‘function()’ returns,
     ‘sys.breakpointhook()’ returns to the built-in *note breakpoint():
     271. function.

     Note that if anything goes wrong while importing the callable named
     by *note PYTHONBREAKPOINT: cd4, a *note RuntimeWarning: 4d8. is
     reported and the breakpoint is ignored.

     Also note that if ‘sys.breakpointhook()’ is overridden
     programmatically, *note PYTHONBREAKPOINT: cd4. is 'not' consulted.

     Added in version 3.7.

 -- Funzione: sys._debugmallocstats ()

     Print low-level information to stderr about the state of CPython’s
     memory allocator.

     If Python is *note built in debug mode: 50a. (*note configure
     -with-pydebug option: 666.), it also performs some expensive
     internal consistency checks.

     Added in version 3.3.

     'Dettaglio dell’implementazione di CPython:' This function is
     specific to CPython.  The exact output format is not defined here,
     and may change.

 -- Dati: sys.dllhandle

     Integer specifying the handle of the Python DLL.

     *note Availability: 2128.: Windows.

 -- Funzione: sys.displayhook (value)

     If 'value' is not ‘None’, this function prints ‘repr(value)’ to
     ‘sys.stdout’, and saves 'value' in ‘builtins._’.  If ‘repr(value)’
     is not encodable to ‘sys.stdout.encoding’ with ‘sys.stdout.errors’
     error handler (which is probably ‘'strict'’), encode it to
     ‘sys.stdout.encoding’ with ‘'backslashreplace'’ error handler.

     ‘sys.displayhook’ is called on the result of evaluating an *note
     expression: 23b5. entered in an interactive Python session.  The
     display of these values can be customized by assigning another
     one-argument function to ‘sys.displayhook’.

     Pseudo-code:

          def displayhook(value):
              if value is None:
                  return
              # Set '_' to None to avoid recursion
              builtins._ = None
              text = repr(value)
              try:
                  sys.stdout.write(text)
              except UnicodeEncodeError:
                  bytes = text.encode(sys.stdout.encoding, 'backslashreplace')
                  if hasattr(sys.stdout, 'buffer'):
                      sys.stdout.buffer.write(bytes)
                  else:
                      text = bytes.decode(sys.stdout.encoding, 'strict')
                      sys.stdout.write(text)
              sys.stdout.write("\n")
              builtins._ = value

     Cambiato nella versione 3.2: Use ‘'backslashreplace'’ error handler
     on *note UnicodeEncodeError: 888.

 -- Dati: sys.dont_write_bytecode

     If this is true, Python won’t try to write ‘.pyc’ files on the
     import of source modules.  This value is initially set to ‘True’ or
     ‘False’ depending on the *note -B: 15d4. command line option and
     the *note PYTHONDONTWRITEBYTECODE: 15d5. environment variable, but
     you can set it yourself to control bytecode file generation.

 -- Dati: sys._emscripten_info

     A *note named tuple: 85f. holding information about the environment
     on the 'wasm32-emscripten' platform.  The named tuple is
     provisional and may change in the future.

      -- Attributo: _emscripten_info.emscripten_version

          Emscripten version as tuple of ints (major, minor, micro),
          e.g.  ‘(3, 1, 8)’.

      -- Attributo: _emscripten_info.runtime

          Runtime string, e.g.  browser user agent, ‘'Node.js
          v14.18.2'’, or ‘'UNKNOWN'’.

      -- Attributo: _emscripten_info.pthreads

          ‘True’ if Python is compiled with Emscripten pthreads support.

      -- Attributo: _emscripten_info.shared_memory

          ‘True’ if Python is compiled with shared memory support.

     *note Availability: 2128.: Emscripten.

     Added in version 3.11.

 -- Dati: sys.pycache_prefix

     If this is set (not ‘None’), Python will write bytecode-cache
     ‘.pyc’ files to (and read them from) a parallel directory tree
     rooted at this directory, rather than from ‘__pycache__’
     directories in the source code tree.  Any ‘__pycache__’ directories
     in the source code tree will be ignored and new ‘.pyc’ files
     written within the pycache prefix.  Thus if you use *note
     compileall: 21. as a pre-build step, you must ensure you run it
     with the same pycache prefix (if any) that you will use at runtime.

     A relative path is interpreted relative to the current working
     directory.

     This value is initially set based on the value of the *note -X:
     16f. ‘pycache_prefix=PATH’ command-line option or the *note
     PYTHONPYCACHEPREFIX: b9d. environment variable (command-line takes
     precedence).  If neither are set, it is ‘None’.

     Added in version 3.8.

 -- Funzione: sys.excepthook (type, value, traceback)

     This function prints out a given traceback and exception to
     ‘sys.stderr’.

     When an exception other than *note SystemExit: f3e. is raised and
     uncaught, the interpreter calls ‘sys.excepthook’ with three
     arguments, the exception class, exception instance, and a traceback
     object.  In an interactive session this happens just before control
     is returned to the prompt; in a Python program this happens just
     before the program exits.  The handling of such top-level
     exceptions can be customized by assigning another three-argument
     function to ‘sys.excepthook’.

     Raise an auditing event ‘sys.excepthook’ with arguments ‘hook’,
     ‘type’, ‘value’, ‘traceback’ when an uncaught exception occurs.  If
     no hook has been set, ‘hook’ may be ‘None’.  If any hook raises an
     exception derived from *note RuntimeError: 244. the call to the
     hook will be suppressed.  Otherwise, the audit hook exception will
     be reported as unraisable and ‘sys.excepthook’ will be called.

     Vedi anche
     ..........

     The *note sys.unraisablehook(): 508. function handles unraisable
     exceptions and the *note threading.excepthook(): a4d. function
     handles exception raised by *note threading.Thread.run(): c33.

 -- Dati: sys.__breakpointhook__
 -- Dati: sys.__displayhook__
 -- Dati: sys.__excepthook__
 -- Dati: sys.__unraisablehook__

     These objects contain the original values of ‘breakpointhook’,
     ‘displayhook’, ‘excepthook’, and ‘unraisablehook’ at the start of
     the program.  They are saved so that ‘breakpointhook’,
     ‘displayhook’ and ‘excepthook’, ‘unraisablehook’ can be restored in
     case they happen to get replaced with broken or alternative
     objects.

     Added in version 3.7: __breakpointhook__

     Added in version 3.8: __unraisablehook__

 -- Funzione: sys.exception ()

     This function, when called while an exception handler is executing
     (such as an ‘except’ or ‘except*’ clause), returns the exception
     instance that was caught by this handler.  When exception handlers
     are nested within one another, only the exception handled by the
     innermost handler is accessible.

     If no exception handler is executing, this function returns ‘None’.

     Added in version 3.11.

 -- Funzione: sys.exc_info ()

     This function returns the old-style representation of the handled
     exception.  If an exception ‘e’ is currently handled (so *note
     exception(): 89c. would return ‘e’), *note exc_info(): 89b. returns
     the tuple ‘(type(e), e, e.__traceback__)’.  That is, a tuple
     containing the type of the exception (a subclass of *note
     BaseException: 7d8.), the exception itself, and a *note traceback
     object: cee. which typically encapsulates the call stack at the
     point where the exception last occurred.

     If no exception is being handled anywhere on the stack, this
     function return a tuple containing three ‘None’ values.

     Cambiato nella versione 3.11: The ‘type’ and ‘traceback’ fields are
     now derived from the ‘value’ (the exception instance), so when an
     exception is modified while it is being handled, the changes are
     reflected in the results of subsequent calls to *note exc_info():
     89b.

 -- Dati: sys.exec_prefix

     A string giving the site-specific directory prefix where the
     platform-dependent Python files are installed; by default, this is
     also ‘'/usr/local'’.  This can be set at build time with the
     ‘--exec-prefix’ argument to the ‘configure’ script.  Specifically,
     all configuration files (e.g.  the ‘pyconfig.h’ header file) are
     installed in the directory ‘`exec_prefix'/lib/python`X.Y'/config’,
     and shared library modules are installed in
     ‘`exec_prefix'/lib/python`X.Y'/lib-dynload’, where 'X.Y' is the
     version number of Python, for example ‘3.2’.

          Nota: If a *note virtual environment: 3e8. is in effect, this
          *note exec_prefix: 3eb. will point to the virtual environment.
          The value for the Python installation will still be available,
          via *note base_exec_prefix: 3ea.  Refer to *note Virtual
          Environments: 489b. for more information.

     Cambiato nella versione 3.14: When running under a *note virtual
     environment: 3e8, *note prefix: 3e7. and *note exec_prefix: 3eb.
     are now set to the virtual environment prefix by the *note path
     initialization: 18c4, instead of *note site: cc.  This means that
     *note prefix: 3e7. and *note exec_prefix: 3eb. always point to the
     virtual environment, even when *note site: cc. is disabled (*note
     -S: 13b0.).

 -- Dati: sys.executable

     A string giving the absolute path of the executable binary for the
     Python interpreter, on systems where this makes sense.  If Python
     is unable to retrieve the real path to its executable, *note
     sys.executable: 3ed. will be an empty string or ‘None’.

 -- Funzione: sys.exit ([arg])

     Raise a *note SystemExit: f3e. exception, signaling an intention to
     exit the interpreter.

     The optional argument 'arg' can be an integer giving the exit
     status (defaulting to zero), or another type of object.  If it is
     an integer, zero is considered «successful termination» and any
     nonzero value is considered «abnormal termination» by shells and
     the like.  Most systems require it to be in the range 0–127, and
     produce undefined results otherwise.  Some systems have a
     convention for assigning specific meanings to specific exit codes,
     but these are generally underdeveloped; Unix programs generally use
     2 for command line syntax errors and 1 for all other kind of
     errors.  If another type of object is passed, ‘None’ is equivalent
     to passing zero, and any other object is printed to *note stderr:
     b35. and results in an exit code of 1.  In particular,
     ‘sys.exit("some error message")’ is a quick way to exit a program
     when an error occurs.

     Since *note exit(): 25c6. ultimately «only» raises an exception, it
     will only exit the process when called from the main thread, and
     the exception is not intercepted.  Cleanup actions specified by
     finally clauses of *note try: 8f9. statements are honored, and it
     is possible to intercept the exit attempt at an outer level.

     Cambiato nella versione 3.6: If an error occurs in the cleanup
     after the Python interpreter has caught *note SystemExit: f3e.
     (such as an error flushing buffered data in the standard streams),
     the exit status is changed to 120.

 -- Dati: sys.flags

     The *note named tuple: 85f. 'flags' exposes the status of command
     line flags.  Flags should only be accessed only by name and not by
     index.  The attributes are read only.

      -- Attributo: flags.debug                             *note -d: 210c.
                                                            
                                                            
      -- Attributo: flags.inspect                           *note -i: 16e2.
                                                            
                                                            
      -- Attributo: flags.interactive                       *note -i: 16e2.
                                                            
                                                            
      -- Attributo: flags.isolated                          *note -I: b59.
                                                            
                                                            
      -- Attributo: flags.optimize                          *note -O: 18c. or *note -OO: fb7.
                                                            
                                                            
      -- Attributo: flags.dont_write_bytecode               *note -B: 15d4.
                                                            
                                                            
      -- Attributo: flags.no_user_site                      *note -s: 1596.
                                                            
                                                            
      -- Attributo: flags.no_site                           *note -S: 13b0.
                                                            
                                                            
      -- Attributo: flags.ignore_environment                *note -E: b58.
                                                            
                                                            
      -- Attributo: flags.verbose                           *note -v: 162c.
                                                            
                                                            
      -- Attributo: flags.bytes_warning                     *note -b: 7fa.
                                                            
                                                            
      -- Attributo: flags.quiet                             *note -q: 1765.
                                                            
                                                            
      -- Attributo: flags.hash_randomization                *note -R: 1e60.
                                                            
                                                            
      -- Attributo: flags.dev_mode                          *note -X dev: 16f.
                                                            (*note Python Development Mode: 509.)
                                                            
                                                            
      -- Attributo: flags.utf8_mode                         *note -X utf8: 16f.
                                                            
                                                            
      -- Attributo: flags.safe_path                         *note -P: 7c2.
                                                            
                                                            
      -- Attributo: flags.int_max_str_digits                *note -X int_max_str_digits: 16f.
                                                            (*note integer string conversion length limitation: 80c.)
                                                            
                                                            
      -- Attributo: flags.warn_default_encoding             *note -X warn_default_encoding: 16f.
                                                            
                                                            
      -- Attributo: flags.gil                               *note -X gil: 16f. and *note PYTHON_GIL: 49b.
                                                            
                                                            
      -- Attributo: flags.thread_inherit_context            *note -X thread_inherit_context: 16f. and
                                                            *note PYTHON_THREAD_INHERIT_CONTEXT: 1850.
                                                            
                                                            
      -- Attributo: flags.context_aware_warnings            *note -X context_aware_warnings: 16f. and
                                                            *note PYTHON_CONTEXT_AWARE_WARNINGS: 1843.
                                                            

     Cambiato nella versione 3.2: Added ‘quiet’ attribute for the new
     *note -q: 1765. flag.

     Added in version 3.2.3: The ‘hash_randomization’ attribute.

     Cambiato nella versione 3.3: Removed obsolete ‘division_warning’
     attribute.

     Cambiato nella versione 3.4: Added ‘isolated’ attribute for *note
     -I: b59. ‘isolated’ flag.

     Cambiato nella versione 3.7: Added the ‘dev_mode’ attribute for the
     new *note Python Development Mode: 509. and the ‘utf8_mode’
     attribute for the new *note -X: 16f. ‘utf8’ flag.

     Cambiato nella versione 3.10: Added ‘warn_default_encoding’
     attribute for *note -X: 16f. ‘warn_default_encoding’ flag.

     Cambiato nella versione 3.11: Added the ‘safe_path’ attribute for
     *note -P: 7c2. option.

     Cambiato nella versione 3.11: Added the ‘int_max_str_digits’
     attribute.

     Cambiato nella versione 3.13: Added the ‘gil’ attribute.

     Cambiato nella versione 3.14: Added the ‘thread_inherit_context’
     attribute.

     Cambiato nella versione 3.14: Added the ‘context_aware_warnings’
     attribute.

 -- Dati: sys.float_info

     A *note named tuple: 85f. holding information about the float type.
     It contains low level information about the precision and internal
     representation.  The values correspond to the various
     floating-point constants defined in the standard header file
     ‘float.h’ for the “C” programming language; see section 5.2.4.2.2
     of the 1999 ISO/IEC C standard *note [C99]: 48f1, “Characteristics
     of floating types”, for details.  Attributes of the ‘float_info’
     named tuple

     attribute                             float.h macro                         explanation
                                                                                 
     ------------------------------------------------------------------------------------------------------------------
                                                                                 
      -- Attributo: float_info.epsilon     ‘DBL_EPSILON’                         difference between 1.0 and the
                                                                                 least value greater than 1.0 that
                                                                                 is representable as a float.
                                                                                 
                                                                                 See also *note math.ulp(): b10.
                                                                                 
                                                                                 
      -- Attributo: float_info.dig         ‘DBL_DIG’                             The maximum number of decimal
                                                                                 digits that can be faithfully
                                                                                 represented in a float; see below.
                                                                                 
                                                                                 
      -- Attributo: float_info.mant_dig    ‘DBL_MANT_DIG’                        Float precision: the number of
                                                                                 base-‘radix’ digits in the
                                                                                 significand of a float.
                                                                                 
                                                                                 
      -- Attributo: float_info.max         ‘DBL_MAX’                             The maximum representable positive
                                                                                 finite float.
                                                                                 
                                                                                 
      -- Attributo: float_info.max_exp     ‘DBL_MAX_EXP’                         The maximum integer 'e' such that
                                                                                 ‘radix**(e-1)’ is a representable
                                                                                 finite float.
                                                                                 
                                                                                 
      -- Attributo:                        ‘DBL_MAX_10_EXP’                      The maximum integer 'e' such that
               float_info.max_10_exp                                             ‘10**e’ is in the range of
                                                                                 representable finite floats.
                                                                                 
                                                                                 
      -- Attributo: float_info.min         ‘DBL_MIN’                             The minimum representable positive
                                                                                 'normalized' float.
                                                                                 
                                                                                 Use *note math.ulp(0.0): b10. to
                                                                                 get the smallest positive
                                                                                 'denormalized' representable float.
                                                                                 
                                                                                 
      -- Attributo: float_info.min_exp     ‘DBL_MIN_EXP’                         The minimum integer 'e' such that
                                                                                 ‘radix**(e-1)’ is a normalized
                                                                                 float.
                                                                                 
                                                                                 
      -- Attributo:                        ‘DBL_MIN_10_EXP’                      The minimum integer 'e' such that
               float_info.min_10_exp                                             ‘10**e’ is a normalized float.
                                                                                 
                                                                                 
      -- Attributo: float_info.radix       ‘FLT_RADIX’                           The radix of exponent
                                                                                 representation.
                                                                                 
                                                                                 
      -- Attributo: float_info.rounds      ‘FLT_ROUNDS’                          An integer representing the
                                                                                 rounding mode for floating-point
                                                                                 arithmetic.  This reflects the
                                                                                 value of the system ‘FLT_ROUNDS’
                                                                                 macro at interpreter startup time:
                                                                                 
                                                                                    * ‘-1’: indeterminable
                                                                                 
                                                                                    * ‘0’: toward zero
                                                                                 
                                                                                    * ‘1’: to nearest
                                                                                 
                                                                                    * ‘2’: toward positive infinity
                                                                                 
                                                                                    * ‘3’: toward negative infinity
                                                                                 
                                                                                 All other values for ‘FLT_ROUNDS’
                                                                                 characterize implementation-defined
                                                                                 rounding behavior.
                                                                                 

     The attribute *note sys.float_info.dig: 48f3. needs further
     explanation.  If ‘s’ is any string representing a decimal number
     with at most ‘sys.float_info.dig’ significant digits, then
     converting ‘s’ to a float and back again will recover a string
     representing the same decimal value:

          >>> import sys
          >>> sys.float_info.dig
          15
          >>> s = '3.14159265358979'    # decimal string with 15 significant digits
          >>> format(float(s), '.15g')  # convert to float and back -> same value
          '3.14159265358979'

     But for strings with more than *note sys.float_info.dig: 48f3.
     significant digits, this isn’t always true:

          >>> s = '9876543211234567'    # 16 significant digits is too many!
          >>> format(float(s), '.16g')  # conversion changes value
          '9876543211234568'

 -- Dati: sys.float_repr_style

     A string indicating how the *note repr(): 1c1. function behaves for
     floats.  If the string has value ‘'short'’ then for a finite float
     ‘x’, ‘repr(x)’ aims to produce a short string with the property
     that ‘float(repr(x)) == x’.  This is the usual behaviour in Python
     3.1 and later.  Otherwise, ‘float_repr_style’ has value ‘'legacy'’
     and ‘repr(x)’ behaves in the same way as it did in versions of
     Python prior to 3.1.

     Added in version 3.1.

 -- Funzione: sys.getallocatedblocks ()

     Return the number of memory blocks currently allocated by the
     interpreter, regardless of their size.  This function is mainly
     useful for tracking and debugging memory leaks.  Because of the
     interpreter’s internal caches, the result can vary from call to
     call; you may have to call *note _clear_internal_caches(): 364. and
     *note gc.collect(): 1b3. to get more predictable results.

     If a Python build or implementation cannot reasonably compute this
     information, *note getallocatedblocks(): 11c9. is allowed to return
     0 instead.

     Added in version 3.4.

 -- Funzione: sys.getunicodeinternedsize ()

     Return the number of unicode objects that have been interned.

     Added in version 3.12.

 -- Funzione: sys.getandroidapilevel ()

     Return the build-time API level of Android as an integer.  This
     represents the minimum version of Android this build of Python can
     run on.  For runtime version information, see *note
     platform.android_ver(): 19ae.

     *note Availability: 2128.: Android.

     Added in version 3.7.

 -- Funzione: sys.getdefaultencoding ()

     Return ‘'utf-8'’.  This is the name of the default string encoding,
     used in methods like *note str.encode(): ad4.

 -- Funzione: sys.getdlopenflags ()

     Return the current value of the flags that are used for ‘dlopen()’
     calls.  Symbolic names for the flag values can be found in the
     *note os: a5. module (‘RTLD_XXX’ constants, e.g.  *note
     os.RTLD_LAZY: 1320.).

     *note Availability: 2128.: Unix.

 -- Funzione: sys.getfilesystemencoding ()

     Get the *note filesystem encoding: 75e.: the encoding used with the
     *note filesystem error handler: 75e. to convert between Unicode
     filenames and bytes filenames.  The filesystem error handler is
     returned from *note getfilesystemencodeerrors(): ee4.

     For best compatibility, str should be used for filenames in all
     cases, although representing filenames as bytes is also supported.
     Functions accepting or returning filenames should support either
     str or bytes and internally convert to the system’s preferred
     representation.

     *note os.fsencode(): e51. and *note os.fsdecode(): e50. should be
     used to ensure that the correct encoding and errors mode are used.

     The *note filesystem encoding and error handler: 75e. are
     configured at Python startup by the *note PyConfig_Read(): 994.
     function: see *note filesystem_encoding: 41b. and *note
     filesystem_errors: 41c. members of *note PyConfig: 3f7.

     Cambiato nella versione 3.2: *note getfilesystemencoding(): e55.
     result cannot be ‘None’ anymore.

     Cambiato nella versione 3.6: Windows is no longer guaranteed to
     return ‘'mbcs'’.  See PEP 529(3) and *note
     _enablelegacywindowsfsencoding(): 33e. for more information.

     Cambiato nella versione 3.7: Return ‘'utf-8'’ if the *note Python
     UTF-8 Mode: 867. is enabled.

 -- Funzione: sys.getfilesystemencodeerrors ()

     Get the *note filesystem error handler: 75e.: the error handler
     used with the *note filesystem encoding: 75e. to convert between
     Unicode filenames and bytes filenames.  The filesystem encoding is
     returned from *note getfilesystemencoding(): e55.

     *note os.fsencode(): e51. and *note os.fsdecode(): e50. should be
     used to ensure that the correct encoding and errors mode are used.

     The *note filesystem encoding and error handler: 75e. are
     configured at Python startup by the *note PyConfig_Read(): 994.
     function: see *note filesystem_encoding: 41b. and *note
     filesystem_errors: 41c. members of *note PyConfig: 3f7.

     Added in version 3.6.

 -- Funzione: sys.get_int_max_str_digits ()

     Returns the current value for the *note integer string conversion
     length limitation: 80c.  See also *note set_int_max_str_digits():
     18d9.

     Added in version 3.11.

 -- Funzione: sys.getrefcount (object)

     Return the reference count of the 'object'.  The count returned is
     generally one higher than you might expect, because it includes the
     (temporary) reference as an argument to *note getrefcount(): 2ce.

     Note that the returned value may not actually reflect how many
     references to the object are actually held.  For example, some
     objects are *note immortal: 290. and have a very high refcount that
     does not reflect the actual number of references.  Consequently, do
     not rely on the returned value to be accurate, other than a value
     of 0 or 1.

     'Dettaglio dell’implementazione di CPython:' *note Immortal: 290.
     objects with a large reference count can be identified via *note
     _is_immortal(): 28f.

     Cambiato nella versione 3.12: Immortal objects have very large
     refcounts that do not match the actual number of references to the
     object.

 -- Funzione: sys.getrecursionlimit ()

     Return the current value of the recursion limit, the maximum depth
     of the Python interpreter stack.  This limit prevents infinite
     recursion from causing an overflow of the C stack and crashing
     Python.  It can be set by *note setrecursionlimit(): 6eb.

 -- Funzione: sys.getsizeof (object[, default])

     Return the size of an object in bytes.  The object can be any type
     of object.  All built-in objects will return correct results, but
     this does not have to hold true for third-party extensions as it is
     implementation specific.

     Only the memory consumption directly attributed to the object is
     accounted for, not the memory consumption of objects it refers to.

     If given, 'default' will be returned if the object does not provide
     means to retrieve the size.  Otherwise a *note TypeError: 198. will
     be raised.

     *note getsizeof(): 1ac3. calls the object’s ‘__sizeof__’ method and
     adds an additional garbage collector overhead if the object is
     managed by the garbage collector.

     See recursive sizeof recipe(4) for an example of using *note
     getsizeof(): 1ac3. recursively to find the size of containers and
     all their contents.

 -- Funzione: sys.getswitchinterval ()

     Return the interpreter’s «thread switch interval» in seconds; see
     *note setswitchinterval(): b46.

     Added in version 3.2.

 -- Funzione: sys._getframe ([depth])

     Return a frame object from the call stack.  If optional integer
     'depth' is given, return the frame object that many calls below the
     top of the stack.  If that is deeper than the call stack, *note
     ValueError: 2ec. is raised.  The default for 'depth' is zero,
     returning the frame at the top of the call stack.

     Raises an *note auditing event: 1c56. ‘sys._getframe’ with argument
     ‘frame’.

     'Dettaglio dell’implementazione di CPython:' This function should
     be used for internal and specialized purposes only.  It is not
     guaranteed to exist in all implementations of Python.

 -- Funzione: sys._getframemodulename ([depth])

     Return the name of a module from the call stack.  If optional
     integer 'depth' is given, return the module that many calls below
     the top of the stack.  If that is deeper than the call stack, or if
     the module is unidentifiable, ‘None’ is returned.  The default for
     'depth' is zero, returning the module at the top of the call stack.

     Raises an *note auditing event: 1c56. ‘sys._getframemodulename’
     with argument ‘depth’.

     'Dettaglio dell’implementazione di CPython:' This function should
     be used for internal and specialized purposes only.  It is not
     guaranteed to exist in all implementations of Python.

     Added in version 3.12.

 -- Funzione: sys.getobjects (limit[, type])

     This function only exists if CPython was built using the
     specialized configure option *note -with-trace-refs: 636.  It is
     intended only for debugging garbage-collection issues.

     Return a list of up to 'limit' dynamically allocated Python
     objects.  If 'type' is given, only objects of that exact type (not
     subtypes) are included.

     Objects from the list are not safe to use.  Specifically, the
     result will include objects from all interpreters that share their
     object allocator state (that is, ones created with *note
     PyInterpreterConfig.use_main_obmalloc: 48ff. set to 1 or using
     *note Py_NewInterpreter(): 1b19, and the *note main interpreter:
     163.).  Mixing objects from different interpreters may lead to
     crashes or other unexpected behavior.

     'Dettaglio dell’implementazione di CPython:' This function should
     be used for specialized purposes only.  It is not guaranteed to
     exist in all implementations of Python.

     Cambiato nella versione 3.14: The result may include objects from
     other interpreters.

 -- Funzione: sys.getprofile ()

     Get the profiler function as set by *note setprofile(): 1705.

 -- Funzione: sys.gettrace ()

     Get the trace function as set by *note settrace(): 2e1.

     'Dettaglio dell’implementazione di CPython:' The *note gettrace():
     15e8. function is intended only for implementing debuggers,
     profilers, coverage tools and the like.  Its behavior is part of
     the implementation platform, rather than part of the language
     definition, and thus may not be available in all Python
     implementations.

 -- Funzione: sys.getwindowsversion ()

     Return a named tuple describing the Windows version currently
     running.  The named elements are 'major', 'minor', 'build',
     'platform', 'service_pack', 'service_pack_minor',
     'service_pack_major', 'suite_mask', 'product_type' and
     'platform_version'.  'service_pack' contains a string,
     'platform_version' a 3-tuple and all other values are integers.
     The components can also be accessed by name, so
     ‘sys.getwindowsversion()[0]’ is equivalent to
     ‘sys.getwindowsversion().major’.  For compatibility with prior
     versions, only the first 5 elements are retrievable by indexing.

     'platform' will be ‘2’ (VER_PLATFORM_WIN32_NT).

     'product_type' may be one of the following values:

     Constant                                    Meaning
                                                 
     ----------------------------------------------------------------------------------
                                                 
     ‘1’ (VER_NT_WORKSTATION)                    The system is a workstation.
                                                 
                                                 
     ‘2’ (VER_NT_DOMAIN_CONTROLLER)              The system is a domain controller.
                                                 
                                                 
     ‘3’ (VER_NT_SERVER)                         The system is a server, but not a
                                                 domain controller.
                                                 

     This function wraps the Win32 ‘GetVersionEx()’ function; see the
     Microsoft documentation on ‘OSVERSIONINFOEX()’ for more information
     about these fields.

     'platform_version' returns the major version, minor version and
     build number of the current operating system, rather than the
     version that is being emulated for the process.  It is intended for
     use in logging rather than for feature detection.

          Nota: 'platform_version' derives the version from kernel32.dll
          which can be of a different version than the OS version.
          Please use *note platform: af. module for achieving accurate
          OS version.

     *note Availability: 2128.: Windows.

     Cambiato nella versione 3.2: Changed to a named tuple and added
     'service_pack_minor', 'service_pack_major', 'suite_mask', and
     'product_type'.

     Cambiato nella versione 3.6: Added 'platform_version'

 -- Funzione: sys.get_asyncgen_hooks ()

     Returns an 'asyncgen_hooks' object, which is similar to a *note
     namedtuple: 4e1. of the form ‘(firstiter, finalizer)’, where
     'firstiter' and 'finalizer' are expected to be either ‘None’ or
     functions which take an *note asynchronous generator iterator:
     4900. as an argument, and are used to schedule finalization of an
     asynchronous generator by an event loop.

     Added in version 3.6: See PEP 525(5) for more details.

          Nota: This function has been added on a provisional basis (see
          PEP 411(6) for details.)

 -- Funzione: sys.get_coroutine_origin_tracking_depth ()

     Get the current coroutine origin tracking depth, as set by *note
     set_coroutine_origin_tracking_depth(): d87.

     Added in version 3.7.

          Nota: This function has been added on a provisional basis (see
          PEP 411(7) for details.)  Use it only for debugging purposes.

 -- Dati: sys.hash_info

     A *note named tuple: 85f. giving parameters of the numeric hash
     implementation.  For more details about hashing of numeric types,
     see *note Hashing dei tipi numerici: 25dd.

      -- Attributo: hash_info.width

          The width in bits used for hash values

      -- Attributo: hash_info.modulus

          The prime modulus P used for numeric hash scheme

      -- Attributo: hash_info.inf

          The hash value returned for a positive infinity

      -- Attributo: hash_info.nan

          (This attribute is no longer used)

      -- Attributo: hash_info.imag

          The multiplier used for the imaginary part of a complex number

      -- Attributo: hash_info.algorithm

          The name of the algorithm for hashing of str, bytes, and
          memoryview

      -- Attributo: hash_info.hash_bits

          The internal output size of the hash algorithm

      -- Attributo: hash_info.seed_bits

          The size of the seed key of the hash algorithm

      -- Attributo: hash_info.cutoff

          Cutoff for small string DJBX33A optimization in range ‘[1,
          cutoff)’.

     Added in version 3.2.

     Cambiato nella versione 3.4: Added 'algorithm', 'hash_bits',
     'seed_bits', and 'cutoff'.

 -- Dati: sys.hexversion

     The version number encoded as a single integer.  This is guaranteed
     to increase with each version, including proper support for
     non-production releases.  For example, to test that the Python
     interpreter is at least version 1.5.2, use:

          if sys.hexversion >= 0x010502F0:
              # use some advanced feature
              ...
          else:
              # use an alternative implementation or warn the user
              ...

     This is called ‘hexversion’ since it only really looks meaningful
     when viewed as the result of passing it to the built-in *note
     hex(): 14d7. function.  The *note named tuple: 85f. *note
     sys.version_info: 8b0. may be used for a more human-friendly
     encoding of the same information.

     More details of ‘hexversion’ can be found at *note API and ABI
     Versioning: 490a.

 -- Dati: sys.implementation

     An object containing information about the implementation of the
     currently running Python interpreter.  The following attributes are
     required to exist in all Python implementations.

     'name' is the implementation’s identifier, e.g.  ‘'cpython'’.  The
     actual string is defined by the Python implementation, but it is
     guaranteed to be lower case.

     'version' is a named tuple, in the same format as *note
     sys.version_info: 8b0.  It represents the version of the Python
     'implementation'.  This has a distinct meaning from the specific
     version of the Python 'language' to which the currently running
     interpreter conforms, which ‘sys.version_info’ represents.  For
     example, for PyPy 1.8 ‘sys.implementation.version’ might be
     ‘sys.version_info(1, 8, 0, 'final', 0)’, whereas ‘sys.version_info’
     would be ‘sys.version_info(2, 7, 2, 'final', 0)’.  For CPython they
     are the same value, since it is the reference implementation.

     'hexversion' is the implementation version in hexadecimal format,
     like *note sys.hexversion: 4909.

     'cache_tag' is the tag used by the import machinery in the
     filenames of cached modules.  By convention, it would be a
     composite of the implementation’s name and version, like
     ‘'cpython-33'’.  However, a Python implementation may use some
     other value if appropriate.  If ‘cache_tag’ is set to ‘None’, it
     indicates that module caching should be disabled.

     'supports_isolated_interpreters' is a boolean value, whether this
     implementation supports multiple isolated interpreters.  It is
     ‘True’ for CPython on most platforms.  Platforms with this support
     implement the low-level ‘_interpreters’ module.

     Vedi anche
     ..........

     PEP 684(8), PEP 734(9), and *note concurrent.interpreters: 25.

     *note sys.implementation: 73c. may contain additional attributes
     specific to the Python implementation.  These non-standard
     attributes must start with an underscore, and are not described
     here.  Regardless of its contents, *note sys.implementation: 73c.
     will not change during a run of the interpreter, nor between
     implementation versions.  (It may change between Python language
     versions, however.)  See PEP 421(10) for more information.

     Added in version 3.3.

     Cambiato nella versione 3.14: Added
     ‘supports_isolated_interpreters’ field.

          Nota: The addition of new required attributes must go through
          the normal PEP process.  See PEP 421(11) for more information.

 -- Dati: sys.int_info

     A *note named tuple: 85f. that holds information about Python’s
     internal representation of integers.  The attributes are read only.

      -- Attributo: int_info.bits_per_digit

          The number of bits held in each digit.  Python integers are
          stored internally in base ‘2**int_info.bits_per_digit’.

      -- Attributo: int_info.sizeof_digit

          The size in bytes of the C type used to represent a digit.

      -- Attributo: int_info.default_max_str_digits

          The default value for *note sys.get_int_max_str_digits():
          1800. when it is not otherwise explicitly configured.

      -- Attributo: int_info.str_digits_check_threshold

          The minimum non-zero value for *note
          sys.set_int_max_str_digits(): 18d9, *note
          PYTHONINTMAXSTRDIGITS: 1b22, or *note -X int_max_str_digits:
          16f.

     Added in version 3.1.

     Cambiato nella versione 3.11: Added *note default_max_str_digits:
     26bf. and *note str_digits_check_threshold: 490d.

 -- Dati: sys.__interactivehook__

     When this attribute exists, its value is automatically called (with
     no arguments) when the interpreter is launched in *note interactive
     mode: 443.  This is done after the *note PYTHONSTARTUP: 1b8. file
     is read, so that you can set this hook there.  The *note site: cc.
     module *note sets this: 11cb.

     Raises an *note auditing event: 1c56. ‘cpython.run_interactivehook’
     with the hook object as the argument when the hook is called on
     startup.

     Added in version 3.4.

 -- Funzione: sys.intern (string)

     Enter 'string' in the table of «interned» strings and return the
     interned string – which is 'string' itself or a copy.  Interning
     strings is useful to gain a little performance on dictionary lookup
     – if the keys in a dictionary are interned, and the lookup key is
     interned, the key comparisons (after hashing) can be done by a
     pointer compare instead of a string compare.  Normally, the names
     used in Python programs are automatically interned, and the
     dictionaries used to hold module, class or instance attributes have
     interned keys.

     Interned strings are not *note immortal: 290.; you must keep a
     reference to the return value of *note intern(): 14e3. around to
     benefit from it.

 -- Funzione: sys._is_gil_enabled ()

     Return *note True: e09. if the *note GIL: 164. is enabled and *note
     False: d2d. if it is disabled.

     Added in version 3.13.

     'Dettaglio dell’implementazione di CPython:' It is not guaranteed
     to exist in all implementations of Python.

 -- Funzione: sys.is_finalizing ()

     Return *note True: e09. if the main Python interpreter is *note
     shutting down: 47a.  Return *note False: d2d. otherwise.

     See also the *note PythonFinalizationError: 479. exception.

     Added in version 3.5.

 -- Dati: sys._jit

     Utilities for observing just-in-time compilation.

     'Dettaglio dell’implementazione di CPython:' JIT compilation is an
     'experimental implementation detail' of CPython.  ‘sys._jit’ is not
     guaranteed to exist or behave the same way in all Python
     implementations, versions, or build configurations.

     Added in version 3.14.

      -- Funzione: _jit.is_available ()

          Return ‘True’ if the current Python executable supports JIT
          compilation, and ‘False’ otherwise.  This can be controlled by
          building CPython with the ‘--experimental-jit’ option on
          Windows, and the *note -enable-experimental-jit: 44e. option
          on all other platforms.

      -- Funzione: _jit.is_enabled ()

          Return ‘True’ if JIT compilation is enabled for the current
          Python process (implies *note sys._jit.is_available(): 44f.),
          and ‘False’ otherwise.  If JIT compilation is available, this
          can be controlled by setting the *note PYTHON_JIT: 44d.
          environment variable to ‘0’ (disabled) or ‘1’ (enabled) at
          interpreter startup.

      -- Funzione: _jit.is_active ()

          Return ‘True’ if the topmost Python frame is currently
          executing JIT code (implies *note sys._jit.is_enabled():
          450.), and ‘False’ otherwise.

               Nota: This function is intended for testing and debugging
               the JIT itself.  It should be avoided for any other
               purpose.

               Nota: Due to the nature of tracing JIT compilers,
               repeated calls to this function may give surprising
               results.  For example, branching on its return value will
               likely lead to unexpected behavior (if doing so causes
               JIT code to be entered or exited):

                    >>> for warmup in range(BIG_NUMBER):
                    ...     # This line is "hot", and is eventually JIT-compiled:
                    ...     if sys._jit.is_active():
                    ...         # This line is "cold", and is run in the interpreter:
                    ...         assert sys._jit.is_active()
                    ...
                    Traceback (most recent call last):
                      File "<stdin>", line 5, in <module>
                        assert sys._jit.is_active()
                               ~~~~~~~~~~~~~~~~~~^^
                    AssertionError

 -- Dati: sys.last_exc

     This variable is not always defined; it is set to the exception
     instance when an exception is not handled and the interpreter
     prints an error message and a stack traceback.  Its intended use is
     to allow an interactive user to import a debugger module and engage
     in post-mortem debugging without having to re-execute the command
     that caused the error.  (Typical use is ‘import pdb; pdb.pm()’ to
     enter the post-mortem debugger; see *note pdb: aa. module for more
     information.)

     Added in version 3.12.

 -- Funzione: sys._is_immortal (op)

     Return *note True: e09. if the given object is *note immortal: 290,
     *note False: d2d. otherwise.

          Nota: Objects that are immortal (and thus return ‘True’ upon
          being passed to this function) are not guaranteed to be
          immortal in future versions, and vice versa for mortal
          objects.

     Added in version 3.14.

     'Dettaglio dell’implementazione di CPython:' This function should
     be used for specialized purposes only.  It is not guaranteed to
     exist in all implementations of Python.

 -- Funzione: sys._is_interned (string)

     Return *note True: e09. if the given string is «interned», *note
     False: d2d. otherwise.

     Added in version 3.13.

     'Dettaglio dell’implementazione di CPython:' It is not guaranteed
     to exist in all implementations of Python.

 -- Dati: sys.last_type
 -- Dati: sys.last_value
 -- Dati: sys.last_traceback

     These three variables are deprecated; use *note sys.last_exc: 6e6.
     instead.  They hold the legacy representation of ‘sys.last_exc’, as
     returned from *note exc_info(): 89b. above.

 -- Dati: sys.maxsize

     An integer giving the maximum value a variable of type *note
     Py_ssize_t: c57. can take.  It’s usually ‘2**31 - 1’ on a 32-bit
     platform and ‘2**63 - 1’ on a 64-bit platform.

 -- Dati: sys.maxunicode

     An integer giving the value of the largest Unicode code point, i.e.
     ‘1114111’ (‘0x10FFFF’ in hexadecimal).

     Cambiato nella versione 3.3: Before PEP 393(12), ‘sys.maxunicode’
     used to be either ‘0xFFFF’ or ‘0x10FFFF’, depending on the
     configuration option that specified whether Unicode characters were
     stored as UCS-2 or UCS-4.

 -- Dati: sys.meta_path

     A list of *note meta path finder: 1272. objects that have their
     *note find_spec(): a6a. methods called to see if one of the objects
     can find the module to be imported.  By default, it holds entries
     that implement Python’s default import semantics.  The *note
     find_spec(): a6a. method is called with at least the absolute name
     of the module being imported.  If the module to be imported is
     contained in a package, then the parent package’s *note __path__:
     203e. attribute is passed in as a second argument.  The method
     returns a *note module spec: 234a, or ‘None’ if the module cannot
     be found.

     Vedi anche
     ..........

     *note importlib.abc.MetaPathFinder: a70.

          The abstract base class defining the interface of finder
          objects on *note meta_path: f29.

     *note importlib.machinery.ModuleSpec: 2255.

          The concrete class which *note find_spec(): a6a. should return
          instances of.

     Cambiato nella versione 3.4: *note Module specs: 234a. were
     introduced in Python 3.4, by PEP 451(13).

     Cambiato nella versione 3.12: Removed the fallback that looked for
     a ‘find_module()’ method if a *note meta_path: f29. entry didn’t
     have a *note find_spec(): a6a. method.

 -- Dati: sys.modules

     This is a dictionary that maps module names to modules which have
     already been loaded.  This can be manipulated to force reloading of
     modules and other tricks.  However, replacing the dictionary will
     not necessarily work as expected and deleting essential items from
     the dictionary may cause Python to fail.  If you want to iterate
     over this global dictionary always use ‘sys.modules.copy()’ or
     ‘tuple(sys.modules)’ to avoid exceptions as its size may change
     during iteration as a side effect of code or activity in other
     threads.

 -- Dati: sys.orig_argv

     The list of the original command line arguments passed to the
     Python executable.

     The elements of *note sys.orig_argv: a43. are the arguments to the
     Python interpreter, while the elements of *note sys.argv: 146c. are
     the arguments to the user’s program.  Arguments consumed by the
     interpreter itself will be present in *note sys.orig_argv: a43. and
     missing from *note sys.argv: 146c.

     Added in version 3.10.

 -- Dati: sys.path

     A list of strings that specifies the search path for modules.
     Initialized from the environment variable *note PYTHONPATH: 121f,
     plus an installation-dependent default.

     By default, as initialized upon program startup, a potentially
     unsafe path is prepended to *note sys.path: 3e4. ('before' the
     entries inserted as a result of *note PYTHONPATH: 121f.):

        * ‘python -m module’ command line: prepend the current working
          directory.

        * ‘python script.py’ command line: prepend the script’s
          directory.  If it’s a symbolic link, resolve symbolic links.

        * ‘python -c code’ and ‘python’ (REPL) command lines: prepend an
          empty string, which means the current working directory.

     To not prepend this potentially unsafe path, use the *note -P: 7c2.
     command line option or the *note PYTHONSAFEPATH: 7c3. environment
     variable.

     A program is free to modify this list for its own purposes.  Only
     strings should be added to *note sys.path: 3e4.; all other data
     types are ignored during import.

     Vedi anche
     ..........

        * Module *note site: cc. This describes how to use .pth files to
          extend *note sys.path: 3e4.

 -- Dati: sys.path_hooks

     A list of callables that take a path argument to try to create a
     *note finder: 2351. for the path.  If a finder can be created, it
     is to be returned by the callable, else raise *note ImportError:
     65b.

     Originally specified in PEP 302(14).

 -- Dati: sys.path_importer_cache

     A dictionary acting as a cache for *note finder: 2351. objects.
     The keys are paths that have been passed to *note sys.path_hooks:
     1226. and the values are the finders that are found.  If a path is
     a valid file system path but no finder is found on *note
     sys.path_hooks: 1226. then ‘None’ is stored.

     Originally specified in PEP 302(15).

 -- Dati: sys.platform

     A string containing a platform identifier.  Known values are:

     System               ‘platform’ value
                          
     -----------------------------------------------------
                          
     AIX                  ‘'aix'’
                          
                          
     Android              ‘'android'’
                          
                          
     Emscripten           ‘'emscripten'’
                          
                          
     FreeBSD              ‘'freebsd'’
                          
                          
     iOS                  ‘'ios'’
                          
                          
     Linux                ‘'linux'’
                          
                          
     macOS                ‘'darwin'’
                          
                          
     Windows              ‘'win32'’
                          
                          
     Windows/Cygwin       ‘'cygwin'’
                          
                          
     WASI                 ‘'wasi'’
                          

     On Unix systems not listed in the table, the value is the
     lowercased OS name as returned by ‘uname -s’, with the first part
     of the version as returned by ‘uname -r’ appended, e.g.
     ‘'sunos5'’, 'at the time when Python was built'.  Unless you want
     to test for a specific system version, it is therefore recommended
     to use the following idiom:

          if sys.platform.startswith('sunos'):
              # SunOS-specific code here...

     Cambiato nella versione 3.3: On Linux, *note sys.platform: 291.
     doesn’t contain the major version anymore.  It is always ‘'linux'’,
     instead of ‘'linux2'’ or ‘'linux3'’.

     Cambiato nella versione 3.8: On AIX, *note sys.platform: 291.
     doesn’t contain the major version anymore.  It is always ‘'aix'’,
     instead of ‘'aix5'’ or ‘'aix7'’.

     Cambiato nella versione 3.13: On Android, *note sys.platform: 291.
     now returns ‘'android'’ rather than ‘'linux'’.

     Cambiato nella versione 3.14: On FreeBSD, *note sys.platform: 291.
     doesn’t contain the major version anymore.  It is always
     ‘'freebsd'’, instead of ‘'freebsd13'’ or ‘'freebsd14'’.

     Vedi anche
     ..........

     *note os.name: 2fe8. has a coarser granularity.  *note os.uname():
     131e. gives system-dependent version information.

     The *note platform: af. module provides detailed checks for the
     system’s identity.

 -- Dati: sys.platlibdir

     Name of the platform-specific library directory.  It is used to
     build the path of standard library and the paths of installed
     extension modules.

     It is equal to ‘"lib"’ on most platforms.  On Fedora and SuSE, it
     is equal to ‘"lib64"’ on 64-bit platforms which gives the following
     ‘sys.path’ paths (where ‘X.Y’ is the Python ‘major.minor’ version):

        * ‘/usr/lib64/pythonX.Y/’: Standard library (like ‘os.py’ of the
          *note os: a5. module)

        * ‘/usr/lib64/pythonX.Y/lib-dynload/’: C extension modules of
          the standard library (like the *note errno: 5b. module, the
          exact filename is platform specific)

        * ‘/usr/lib/pythonX.Y/site-packages/’ (always use ‘lib’, not
          *note sys.platlibdir: b34.): Third-party modules

        * ‘/usr/lib64/pythonX.Y/site-packages/’: C extension modules of
          third-party packages

     Added in version 3.9.

 -- Dati: sys.prefix

     A string giving the site-specific directory prefix where the
     platform independent Python files are installed; on Unix, the
     default is ‘/usr/local’.  This can be set at build time with the
     *note -prefix: 2138. argument to the ‘configure’ script.  See *note
     Installation paths: 449. for derived paths.

          Nota: If a *note virtual environment: 3e8. is in effect, this
          *note prefix: 3e7. will point to the virtual environment.  The
          value for the Python installation will still be available, via
          *note base_prefix: 3e6.  Refer to *note Virtual Environments:
          489b. for more information.

     Cambiato nella versione 3.14: When running under a *note virtual
     environment: 3e8, *note prefix: 3e7. and *note exec_prefix: 3eb.
     are now set to the virtual environment prefix by the *note path
     initialization: 18c4, instead of *note site: cc.  This means that
     *note prefix: 3e7. and *note exec_prefix: 3eb. always point to the
     virtual environment, even when *note site: cc. is disabled (*note
     -S: 13b0.).

 -- Dati: sys.ps1
 -- Dati: sys.ps2

     Strings specifying the primary and secondary prompt of the
     interpreter.  These are only defined if the interpreter is in
     interactive mode.  Their initial values in this case are ‘'>>> '’
     and ‘'... '’.  If a non-string object is assigned to either
     variable, its *note str(): 169. is re-evaluated each time the
     interpreter prepares to read a new interactive command; this can be
     used to implement a dynamic prompt.

 -- Funzione: sys.setdlopenflags (n)

     Set the flags used by the interpreter for ‘dlopen()’ calls, such as
     when the interpreter loads extension modules.  Among other things,
     this will enable a lazy resolving of symbols when importing a
     module, if called as ‘sys.setdlopenflags(0)’.  To share symbols
     across extension modules, call as
     ‘sys.setdlopenflags(os.RTLD_GLOBAL)’.  Symbolic names for the flag
     values can be found in the *note os: a5. module (‘RTLD_XXX’
     constants, e.g.  *note os.RTLD_LAZY: 1320.).

     *note Availability: 2128.: Unix.

 -- Funzione: sys.set_int_max_str_digits (maxdigits)

     Set the *note integer string conversion length limitation: 80c.
     used by this interpreter.  See also *note get_int_max_str_digits():
     1800.

     Added in version 3.11.

 -- Funzione: sys.setprofile (profilefunc)

     Set the system’s profile function, which allows you to implement a
     Python source code profiler in Python.  See chapter *note The
     Python Profilers: 47de. for more information on the Python
     profiler.  The system’s profile function is called similarly to the
     system’s trace function (see *note settrace(): 2e1.), but it is
     called with different events, for example it isn’t called for each
     executed line of code (only on call and return, but the return
     event is reported even when an exception has been set).  The
     function is thread-specific, but there is no way for the profiler
     to know about context switches between threads, so it does not make
     sense to use this in the presence of multiple threads.  Also, its
     return value is not used, so it can simply return ‘None’.  Error in
     the profile function will cause itself unset.

          Nota: The same tracing mechanism is used for ‘setprofile()’ as
          *note settrace(): 2e1.  To trace calls with ‘setprofile()’
          inside a tracing function (e.g.  in a debugger breakpoint),
          see *note call_tracing(): 1bab.

     Profile functions should have three arguments: 'frame', 'event',
     and 'arg'.  'frame' is the current stack frame.  'event' is a
     string: ‘'call'’, ‘'return'’, ‘'c_call'’, ‘'c_return'’, or
     ‘'c_exception'’.  'arg' depends on the event type.

     The events have the following meaning:

     ‘'call'’

          A function is called (or some other code block entered).  The
          profile function is called; 'arg' is ‘None’.

     ‘'return'’

          A function (or other code block) is about to return.  The
          profile function is called; 'arg' is the value that will be
          returned, or ‘None’ if the event is caused by an exception
          being raised.

     ‘'c_call'’

          A C function is about to be called.  This may be an extension
          function or a built-in.  'arg' is the C function object.

     ‘'c_return'’

          A C function has returned.  'arg' is the C function object.

     ‘'c_exception'’

          A C function has raised an exception.  'arg' is the C function
          object.

     Raises an *note auditing event: 1c56. ‘sys.setprofile’ with no
     arguments.

 -- Funzione: sys.setrecursionlimit (limit)

     Set the maximum depth of the Python interpreter stack to 'limit'.
     This limit prevents infinite recursion from causing an overflow of
     the C stack and crashing Python.

     The highest possible limit is platform-dependent.  A user may need
     to set the limit higher when they have a program that requires deep
     recursion and a platform that supports a higher limit.  This should
     be done with care, because a too-high limit can lead to a crash.

     If the new limit is too low at the current recursion depth, a *note
     RecursionError: f6a. exception is raised.

     Cambiato nella versione 3.5.1: A *note RecursionError: f6a.
     exception is now raised if the new limit is too low at the current
     recursion depth.

 -- Funzione: sys.setswitchinterval (interval)

     Set the interpreter’s thread switch interval (in seconds).  This
     floating-point value determines the ideal duration of the
     «timeslices» allocated to concurrently running Python threads.
     Please note that the actual value can be higher, especially if
     long-running internal functions or methods are used.  Also, which
     thread becomes scheduled at the end of the interval is the
     operating system’s decision.  The interpreter doesn’t have its own
     scheduler.

     Added in version 3.2.

 -- Funzione: sys.settrace (tracefunc)

     Set the system’s trace function, which allows you to implement a
     Python source code debugger in Python.  The function is
     thread-specific; for a debugger to support multiple threads, it
     must register a trace function using *note settrace(): 2e1. for
     each thread being debugged or use *note threading.settrace(): a4a.

     Trace functions should have three arguments: 'frame', 'event', and
     'arg'.  'frame' is the *note current stack frame: 8f0.  'event' is
     a string: ‘'call'’, ‘'line'’, ‘'return'’, ‘'exception'’ or
     ‘'opcode'’.  'arg' depends on the event type.

     The trace function is invoked (with 'event' set to ‘'call'’)
     whenever a new local scope is entered; it should return a reference
     to a local trace function to be used for the new scope, or ‘None’
     if the scope shouldn’t be traced.

     The local trace function should return a reference to itself, or to
     another function which would then be used as the local trace
     function for the scope.

     If there is any error occurred in the trace function, it will be
     unset, just like ‘settrace(None)’ is called.

          Nota: Tracing is disabled while calling the trace function
          (e.g.  a function set by ‘settrace()’).  For recursive tracing
          see *note call_tracing(): 1bab.

     The events have the following meaning:

     ‘'call'’

          A function is called (or some other code block entered).  The
          global trace function is called; 'arg' is ‘None’; the return
          value specifies the local trace function.

     ‘'line'’

          The interpreter is about to execute a new line of code or
          re-execute the condition of a loop.  The local trace function
          is called; 'arg' is ‘None’; the return value specifies the new
          local trace function.  See ‘Objects/lnotab_notes.txt’ for a
          detailed explanation of how this works.  Per-line events may
          be disabled for a frame by setting *note f_trace_lines: dd8.
          to *note False: d2d. on that *note frame: 8f0.

     ‘'return'’

          A function (or other code block) is about to return.  The
          local trace function is called; 'arg' is the value that will
          be returned, or ‘None’ if the event is caused by an exception
          being raised.  The trace function’s return value is ignored.

     ‘'exception'’

          An exception has occurred.  The local trace function is
          called; 'arg' is a tuple ‘(exception, value, traceback)’; the
          return value specifies the new local trace function.

     ‘'opcode'’

          The interpreter is about to execute a new opcode (see *note
          dis: 3c. for opcode details).  The local trace function is
          called; 'arg' is ‘None’; the return value specifies the new
          local trace function.  Per-opcode events are not emitted by
          default: they must be explicitly requested by setting *note
          f_trace_opcodes: dd9. to *note True: e09. on the *note frame:
          8f0.

     Note that as an exception is propagated down the chain of callers,
     an ‘'exception'’ event is generated at each level.

     For more fine-grained usage, it’s possible to set a trace function
     by assigning ‘frame.f_trace = tracefunc’ explicitly, rather than
     relying on it being set indirectly via the return value from an
     already installed trace function.  This is also required for
     activating the trace function on the current frame, which *note
     settrace(): 2e1. doesn’t do.  Note that in order for this to work,
     a global tracing function must have been installed with *note
     settrace(): 2e1. in order to enable the runtime tracing machinery,
     but it doesn’t need to be the same tracing function (e.g.  it could
     be a low overhead tracing function that simply returns ‘None’ to
     disable itself immediately on each frame).

     For more information on code and frame objects, refer to *note The
     standard type hierarchy: 2318.

     Raises an *note auditing event: 1c56. ‘sys.settrace’ with no
     arguments.

     'Dettaglio dell’implementazione di CPython:' The *note settrace():
     2e1. function is intended only for implementing debuggers,
     profilers, coverage tools and the like.  Its behavior is part of
     the implementation platform, rather than part of the language
     definition, and thus may not be available in all Python
     implementations.

     Cambiato nella versione 3.7: ‘'opcode'’ event type added; *note
     f_trace_lines: dd8. and *note f_trace_opcodes: dd9. attributes
     added to frames

 -- Funzione: sys.set_asyncgen_hooks ([firstiter] [, finalizer])

     Accepts two optional keyword arguments which are callables that
     accept an *note asynchronous generator iterator: 4900. as an
     argument.  The 'firstiter' callable will be called when an
     asynchronous generator is iterated for the first time.  The
     'finalizer' will be called when an asynchronous generator is about
     to be garbage collected.

     Raises an *note auditing event: 1c56.
     ‘sys.set_asyncgen_hooks_firstiter’ with no arguments.

     Raises an *note auditing event: 1c56.
     ‘sys.set_asyncgen_hooks_finalizer’ with no arguments.

     Two auditing events are raised because the underlying API consists
     of two calls, each of which must raise its own event.

     Added in version 3.6: See PEP 525(16) for more details, and for a
     reference example of a 'finalizer' method see the implementation of
     ‘asyncio.Loop.shutdown_asyncgens’ in Lib/asyncio/base_events.py(17)

          Nota: This function has been added on a provisional basis (see
          PEP 411(18) for details.)

 -- Funzione: sys.set_coroutine_origin_tracking_depth (depth)

     Allows enabling or disabling coroutine origin tracking.  When
     enabled, the ‘cr_origin’ attribute on coroutine objects will
     contain a tuple of (filename, line number, function name) tuples
     describing the traceback where the coroutine object was created,
     with the most recent call first.  When disabled, ‘cr_origin’ will
     be ‘None’.

     To enable, pass a 'depth' value greater than zero; this sets the
     number of frames whose information will be captured.  To disable,
     set 'depth' to zero.

     This setting is thread-specific.

     Added in version 3.7.

          Nota: This function has been added on a provisional basis (see
          PEP 411(19) for details.)  Use it only for debugging purposes.

 -- Funzione: sys.activate_stack_trampoline (backend, /)

     Activate the stack profiler trampoline 'backend'.  The only
     supported backend is ‘"perf"’.

     Stack trampolines cannot be activated if the JIT is active.

     *note Availability: 2128.: Linux.

     Added in version 3.12.

     Vedi anche
     ..........

        * *note Python support for the Linux perf profiler: 4af.

        * ‘https://perf.wiki.kernel.org’

 -- Funzione: sys.deactivate_stack_trampoline ()

     Deactivate the current stack profiler trampoline backend.

     If no stack profiler is activated, this function has no effect.

     *note Availability: 2128.: Linux.

     Added in version 3.12.

 -- Funzione: sys.is_stack_trampoline_active ()

     Return ‘True’ if a stack profiler trampoline is active.

     *note Availability: 2128.: Linux.

     Added in version 3.12.

 -- Funzione: sys.remote_exec (pid, script)

     Executes 'script', a file containing Python code in the remote
     process with the given 'pid'.

     This function returns immediately, and the code will be executed by
     the target process’s main thread at the next available opportunity,
     similarly to how signals are handled.  There is no interface to
     determine when the code has been executed.  The caller is
     responsible for making sure that the file still exists whenever the
     remote process tries to read it and that it hasn’t been
     overwritten.

     The remote process must be running a CPython interpreter of the
     same major and minor version as the local process.  If either the
     local or remote interpreter is pre-release (alpha, beta, or release
     candidate) then the local and remote interpreters must be the same
     exact version.

     See *note Remote debugging attachment protocol: 490f. for more
     information about the remote debugging mechanism.

     When the code is executed in the remote process, an *note auditing
     event: 1c56. ‘sys.remote_exec’ is raised with the 'pid' and the
     path to the script file.  This event is raised in the process that
     called *note sys.remote_exec(): 16d.

     When the script is executed in the remote process, an *note
     auditing event: 1c56. ‘cpython.remote_debugger_script’ is raised
     with the path in the remote process.  This event is raised in the
     remote process, not the one that called *note sys.remote_exec():
     16d.

     *note Availability: 2128.: Unix, Windows.

     Added in version 3.14: See PEP 768(20) for more details.

 -- Funzione: sys._enablelegacywindowsfsencoding ()

     Changes the *note filesystem encoding and error handler: 75e. to
     “mbcs” and “replace” respectively, for consistency with versions of
     Python prior to 3.6.

     This is equivalent to defining the *note
     PYTHONLEGACYWINDOWSFSENCODING: 33f. environment variable before
     launching Python.

     See also *note sys.getfilesystemencoding(): e55. and *note
     sys.getfilesystemencodeerrors(): ee4.

     *note Availability: 2128.: Windows.

          Nota: Changing the filesystem encoding after Python startup is
          risky because the old fsencoding or paths encoded by the old
          fsencoding may be cached somewhere.  Use *note
          PYTHONLEGACYWINDOWSFSENCODING: 33f. instead.

     Added in version 3.6: See PEP 529(21) for more details.

     Deprecated since version 3.13, will be removed in version 3.16: Use
     *note PYTHONLEGACYWINDOWSFSENCODING: 33f. instead.

 -- Dati: sys.stdin
 -- Dati: sys.stdout
 -- Dati: sys.stderr

     *note File objects: 13cb. used by the interpreter for standard
     input, output and errors:

        * ‘stdin’ is used for all interactive input (including calls to
          *note input(): 14e0.);

        * ‘stdout’ is used for the output of *note print(): 1177. and
          *note expression: 23b5. statements and for the prompts of
          *note input(): 14e0.;

        * The interpreter’s own prompts and its error messages go to
          ‘stderr’.

     These streams are regular *note text files: 2057. like those
     returned by the *note open(): 316. function.  Their parameters are
     chosen as follows:

        * The encoding and error handling are is initialized from *note
          PyConfig.stdio_encoding: 644. and *note PyConfig.stdio_errors:
          4910.

          On Windows, UTF-8 is used for the console device.
          Non-character devices such as disk files and pipes use the
          system locale encoding (i.e.  the ANSI codepage).  Non-console
          character devices such as NUL (i.e.  where ‘isatty()’ returns
          ‘True’) use the value of the console input and output
          codepages at startup, respectively for stdin and
          stdout/stderr.  This defaults to the system *note locale
          encoding: 54b. if the process is not initially attached to a
          console.

          The special behaviour of the console can be overridden by
          setting the environment variable PYTHONLEGACYWINDOWSSTDIO
          before starting Python.  In that case, the console codepages
          are used as for any other character device.

          Under all platforms, you can override the character encoding
          by setting the *note PYTHONIOENCODING: 120c. environment
          variable before starting Python or by using the new *note -X:
          16f. ‘utf8’ command line option and *note PYTHONUTF8: cd1.
          environment variable.  However, for the Windows console, this
          only applies when *note PYTHONLEGACYWINDOWSSTDIO: e57. is also
          set.

        * When interactive, the ‘stdout’ stream is line-buffered.
          Otherwise, it is block-buffered like regular text files.  The
          ‘stderr’ stream is line-buffered in both cases.  You can make
          both streams unbuffered by passing the *note -u: 1d75.
          command-line option or setting the *note PYTHONUNBUFFERED:
          1d76. environment variable.

     Cambiato nella versione 3.9: Non-interactive ‘stderr’ is now
     line-buffered instead of fully buffered.

          Nota: To write or read binary data from/to the standard
          streams, use the underlying binary *note buffer: 14ab. object.
          For example, to write bytes to *note stdout: ccf, use
          ‘sys.stdout.buffer.write(b'abc')’.

          However, if you are writing a library (and do not control in
          which context its code will be executed), be aware that the
          standard streams may be replaced with file-like objects like
          *note io.StringIO: 112b. which do not support the ‘buffer’
          attribute.

 -- Dati: sys.__stdin__
 -- Dati: sys.__stdout__
 -- Dati: sys.__stderr__

     These objects contain the original values of ‘stdin’, ‘stderr’ and
     ‘stdout’ at the start of the program.  They are used during
     finalization, and could be useful to print to the actual standard
     stream no matter if the ‘sys.std*’ object has been redirected.

     It can also be used to restore the actual files to known working
     file objects in case they have been overwritten with a broken
     object.  However, the preferred way to do this is to explicitly
     save the previous stream before replacing it, and restore the saved
     object.

          Nota: Under some conditions ‘stdin’, ‘stdout’ and ‘stderr’ as
          well as the original values ‘__stdin__’, ‘__stdout__’ and
          ‘__stderr__’ can be ‘None’.  It is usually the case for
          Windows GUI apps that aren’t connected to a console and Python
          apps started with ‘pythonw’.

 -- Dati: sys.stdlib_module_names

     A frozenset of strings containing the names of standard library
     modules.

     It is the same on all platforms.  Modules which are not available
     on some platforms and modules disabled at Python build are also
     listed.  All module kinds are listed: pure Python, built-in, frozen
     and extension modules.  Test modules are excluded.

     For packages, only the main package is listed: sub-packages and
     sub-modules are not listed.  For example, the ‘email’ package is
     listed, but the ‘email.mime’ sub-package and the ‘email.message’
     sub-module are not listed.

     See also the *note sys.builtin_module_names: 2031. list.

     Added in version 3.10.

 -- Dati: sys.thread_info

     A *note named tuple: 85f. holding information about the thread
     implementation.

      -- Attributo: thread_info.name

          The name of the thread implementation:

             * ‘"nt"’: Windows threads

             * ‘"pthread"’: POSIX threads

             * ‘"pthread-stubs"’: stub POSIX threads (on WebAssembly
               platforms without threading support)

             * ‘"solaris"’: Solaris threads

      -- Attributo: thread_info.lock

          The name of the lock implementation:

             * ‘"semaphore"’: a lock uses a semaphore

             * ‘"mutex+cond"’: a lock uses a mutex and a condition
               variable

             * ‘None’ if this information is unknown

      -- Attributo: thread_info.version

          The name and version of the thread library.  It is a string,
          or ‘None’ if this information is unknown.

     Added in version 3.3.

 -- Dati: sys.tracebacklimit

     When this variable is set to an integer value, it determines the
     maximum number of levels of traceback information printed when an
     unhandled exception occurs.  The default is ‘1000’.  When set to
     ‘0’ or less, all traceback information is suppressed and only the
     exception type and value are printed.

 -- Funzione: sys.unraisablehook (unraisable, /)

     Handle an unraisable exception.

     Called when an exception has occurred but there is no way for
     Python to handle it.  For example, when a destructor raises an
     exception or during garbage collection (*note gc.collect(): 1b3.).

     The 'unraisable' argument has the following attributes:

        * ‘exc_type’: Exception type.

        * ‘exc_value’: Exception value, can be ‘None’.

        * ‘exc_traceback’: Exception traceback, can be ‘None’.

        * ‘err_msg’: Error message, can be ‘None’.

        * ‘object’: Object causing the exception, can be ‘None’.

     The default hook formats ‘err_msg’ and ‘object’ as: ‘f'{err_msg}:
     {object!r}'’; use «Exception ignored in» error message if ‘err_msg’
     is ‘None’.

     *note sys.unraisablehook(): 508. can be overridden to control how
     unraisable exceptions are handled.

     Vedi anche
     ..........

     *note excepthook(): a0e. which handles uncaught exceptions.

          Avvertimento: Storing ‘exc_value’ using a custom hook can
          create a reference cycle.  It should be cleared explicitly to
          break the reference cycle when the exception is no longer
          needed.

          Storing ‘object’ using a custom hook can resurrect it if it is
          set to an object which is being finalized.  Avoid storing
          ‘object’ after the custom hook completes to avoid resurrecting
          objects.

     Raise an auditing event ‘sys.unraisablehook’ with arguments 'hook',
     'unraisable' when an exception that cannot be handled occurs.  The
     'unraisable' object is the same as what will be passed to the hook.
     If no hook has been set, 'hook' may be ‘None’.

     Added in version 3.8.

 -- Dati: sys.version

     A string containing the version number of the Python interpreter
     plus additional information on the build number and compiler used.
     This string is displayed when the interactive interpreter is
     started.  Do not extract version information out of it, rather, use
     *note version_info: 8b0. and the functions provided by the *note
     platform: af. module.

 -- Dati: sys.api_version

     The C API version, equivalent to the C macro *note
     PYTHON_API_VERSION: 4916.  Defined for backwards compatibility.

     Currently, this constant is not updated in new Python versions, and
     is not useful for versioning.  This may change in the future.

 -- Dati: sys.version_info

     A tuple containing the five components of the version number:
     'major', 'minor', 'micro', 'releaselevel', and 'serial'.  All
     values except 'releaselevel' are integers; the release level is
     ‘'alpha'’, ‘'beta'’, ‘'candidate'’, or ‘'final'’.  The
     ‘version_info’ value corresponding to the Python version 2.0 is
     ‘(2, 0, 0, 'final', 0)’.  The components can also be accessed by
     name, so ‘sys.version_info[0]’ is equivalent to
     ‘sys.version_info.major’ and so on.

     Cambiato nella versione 3.1: Added named component attributes.

 -- Dati: sys.warnoptions

     This is an implementation detail of the warnings framework; do not
     modify this value.  Refer to the *note warnings: 118. module for
     more information on the warnings framework.

 -- Dati: sys.winver

     The version number used to form registry keys on Windows platforms.
     This is stored as string resource 1000 in the Python DLL. The value
     is normally the major and minor versions of the running Python
     interpreter.  It is provided in the *note sys: df. module for
     informational purposes; modifying this value has no effect on the
     registry keys used by Python.

     *note Availability: 2128.: Windows.

 -- Dati: sys.monitoring

     Namespace containing functions and constants for register callbacks
     and controlling monitoring events.  See *note sys.monitoring: e0.
     for details.

 -- Dati: sys._xoptions

     A dictionary of the various implementation-specific flags passed
     through the *note -X: 16f. command-line option.  Option names are
     either mapped to their values, if given explicitly, or to *note
     True: e09.  Example:

          $ ./python -Xa=b -Xc
          Python 3.2a3+ (py3k, Oct 16 2010, 20:14:50)
          [GCC 4.4.3] on linux2
          Type "help", "copyright", "credits" or "license" for more information.
          >>> import sys
          >>> sys._xoptions
          {'a': 'b', 'c': True}

     'Dettaglio dell’implementazione di CPython:' This is a
     CPython-specific way of accessing options passed through *note -X:
     16f.  Other implementations may export them through other means, or
     not at all.

     Added in version 3.2.

Citations
.........

(C99) ISO/IEC 9899:1999.  «Programming languages – C.» A public draft of
this standard is available at
‘https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf’.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3149/

   (2) https://peps.python.org/pep-0578/

   (3) https://peps.python.org/pep-0529/

   (4) 
https://code.activestate.com/recipes/577504-compute-memory-footprint-of-an-object-and-its-cont/

   (5) https://peps.python.org/pep-0525/

   (6) https://peps.python.org/pep-0411/

   (7) https://peps.python.org/pep-0411/

   (8) https://peps.python.org/pep-0684/

   (9) https://peps.python.org/pep-0734/

   (10) https://peps.python.org/pep-0421/

   (11) https://peps.python.org/pep-0421/

   (12) https://peps.python.org/pep-0393/

   (13) https://peps.python.org/pep-0451/

   (14) https://peps.python.org/pep-0302/

   (15) https://peps.python.org/pep-0302/

   (16) https://peps.python.org/pep-0525/

   (17) 
https://github.com/python/cpython/tree/3.14/Lib/asyncio/base_events.py

   (18) https://peps.python.org/pep-0411/

   (19) https://peps.python.org/pep-0411/

   (20) https://peps.python.org/pep-0768/

   (21) https://peps.python.org/pep-0529/


File: python.info,  Node: sys monitoring — Execution event monitoring,  Next: sysconfig — Provide access to Python’s configuration information,  Prev: sys — System-specific parameters and functions,  Up: Python Runtime Services

5.29.2 ‘sys.monitoring’ — Execution event monitoring
----------------------------------------------------

Added in version 3.12.

__________________________________________________________________

     Nota: *note sys.monitoring: e0. is a namespace within the *note
     sys: df. module, not an independent module, so there is no need to
     ‘import sys.monitoring’, simply ‘import sys’ and then use
     ‘sys.monitoring’.

This namespace provides access to the functions and constants necessary
to activate and control event monitoring.

As programs execute, events occur that might be of interest to tools
that monitor execution.  The *note sys.monitoring: e0. namespace
provides means to receive callbacks when events of interest occur.

The monitoring API consists of three components:

   * *note Tool identifiers: 491b.

   * *note Events: 491c.

   * *note Callbacks: 491d.

* Menu:

* Tool identifiers::
* Events::
* Turning events on and off::
* Registering callback functions::


File: python.info,  Node: Tool identifiers,  Next: Events,  Up: sys monitoring — Execution event monitoring

5.29.2.1 Tool identifiers
.........................

A tool identifier is an integer and the associated name.  Tool
identifiers are used to discourage tools from interfering with each
other and to allow multiple tools to operate at the same time.
Currently tools are completely independent and cannot be used to monitor
each other.  This restriction may be lifted in the future.

Before registering or activating events, a tool should choose an
identifier.  Identifiers are integers in the range 0 to 5 inclusive.

* Menu:

* Registering and using tools::


File: python.info,  Node: Registering and using tools,  Up: Tool identifiers

5.29.2.2 Registering and using tools
....................................

 -- Funzione: sys.monitoring.use_tool_id (tool_id: int, name: str, /) ->
          None

     Must be called before 'tool_id' can be used.  'tool_id' must be in
     the range 0 to 5 inclusive.  Raises a *note ValueError: 2ec. if
     'tool_id' is in use.

 -- Funzione: sys.monitoring.clear_tool_id (tool_id: int, /) -> None

     Unregister all events and callback functions associated with
     'tool_id'.

 -- Funzione: sys.monitoring.free_tool_id (tool_id: int, /) -> None

     Should be called once a tool no longer requires 'tool_id'.  Will
     call *note clear_tool_id(): 1916. before releasing 'tool_id'.

 -- Funzione: sys.monitoring.get_tool (tool_id: int, /) -> str | None

     Returns the name of the tool if 'tool_id' is in use, otherwise it
     returns ‘None’.  'tool_id' must be in the range 0 to 5 inclusive.

All IDs are treated the same by the VM with regard to events, but the
following IDs are pre-defined to make co-operation of tools easier:

     sys.monitoring.DEBUGGER_ID = 0
     sys.monitoring.COVERAGE_ID = 1
     sys.monitoring.PROFILER_ID = 2
     sys.monitoring.OPTIMIZER_ID = 5


File: python.info,  Node: Events,  Next: Turning events on and off,  Prev: Tool identifiers,  Up: sys monitoring — Execution event monitoring

5.29.2.3 Events
...............

The following events are supported:

 -- monitoring-event: sys.monitoring.events.BRANCH_LEFT

     A conditional branch goes left.

     It is up to the tool to determine how to present «left» and «right»
     branches.  There is no guarantee which branch is «left» and which
     is «right», except that it will be consistent for the duration of
     the program.

 -- monitoring-event: sys.monitoring.events.BRANCH_RIGHT

     A conditional branch goes right.

 -- monitoring-event: sys.monitoring.events.CALL

     A call in Python code (event occurs before the call).

 -- monitoring-event: sys.monitoring.events.C_RAISE

     An exception raised from any callable, except for Python functions
     (event occurs after the exit).

 -- monitoring-event: sys.monitoring.events.C_RETURN

     Return from any callable, except for Python functions (event occurs
     after the return).

 -- monitoring-event: sys.monitoring.events.EXCEPTION_HANDLED

     An exception is handled.

 -- monitoring-event: sys.monitoring.events.INSTRUCTION

     A VM instruction is about to be executed.

 -- monitoring-event: sys.monitoring.events.JUMP

     An unconditional jump in the control flow graph is made.

 -- monitoring-event: sys.monitoring.events.LINE

     An instruction is about to be executed that has a different line
     number from the preceding instruction.

 -- monitoring-event: sys.monitoring.events.PY_RESUME

     Resumption of a Python function (for generator and coroutine
     functions), except for ‘throw()’ calls.

 -- monitoring-event: sys.monitoring.events.PY_RETURN

     Return from a Python function (occurs immediately before the
     return, the callee’s frame will be on the stack).

 -- monitoring-event: sys.monitoring.events.PY_START

     Start of a Python function (occurs immediately after the call, the
     callee’s frame will be on the stack)

 -- monitoring-event: sys.monitoring.events.PY_THROW

     A Python function is resumed by a ‘throw()’ call.

 -- monitoring-event: sys.monitoring.events.PY_UNWIND

     Exit from a Python function during exception unwinding.  This
     includes exceptions raised directly within the function and that
     are allowed to continue to propagate.

 -- monitoring-event: sys.monitoring.events.PY_YIELD

     Yield from a Python function (occurs immediately before the yield,
     the callee’s frame will be on the stack).

 -- monitoring-event: sys.monitoring.events.RAISE

     An exception is raised, except those that cause a *note
     STOP_ITERATION: 492d. event.

 -- monitoring-event: sys.monitoring.events.RERAISE

     An exception is re-raised, for example at the end of a *note
     finally: 1b0. block.

 -- monitoring-event: sys.monitoring.events.STOP_ITERATION

     An artificial *note StopIteration: df7. is raised; see *note the
     STOP_ITERATION event: 492f.

More events may be added in the future.

These events are attributes of the ‘sys.monitoring.events’ namespace.
Each event is represented as a power-of-2 integer constant.  To define a
set of events, simply bitwise OR the individual events together.  For
example, to specify both *note PY_RETURN: 4929. and *note PY_START:
492a. events, use the expression ‘PY_RETURN | PY_START’.

 -- monitoring-event: sys.monitoring.events.NO_EVENTS

     An alias for ‘0’ so users can do explicit comparisons like:

          if get_events(DEBUGGER_ID) == NO_EVENTS:
              ...

     Setting this event deactivates all events.

* Menu:

* Local events::
* Deprecated event::
* Ancillary events::
* Other events::
* The STOP_ITERATION event::


File: python.info,  Node: Local events,  Next: Deprecated event,  Up: Events

5.29.2.4 Local events
.....................

Local events are associated with normal execution of the program and
happen at clearly defined locations.  All local events can be disabled.
The local events are:

   * *note PY_START: 492a.

   * *note PY_RESUME: 4928.

   * *note PY_RETURN: 4929.

   * *note PY_YIELD: 492c.

   * *note CALL: 19a5.

   * *note LINE: 4927.

   * *note INSTRUCTION: 4925.

   * *note JUMP: 4926.

   * *note BRANCH_LEFT: 295.

   * *note BRANCH_RIGHT: 296.

   * *note STOP_ITERATION: 492d.


File: python.info,  Node: Deprecated event,  Next: Ancillary events,  Prev: Local events,  Up: Events

5.29.2.5 Deprecated event
.........................

   * ‘BRANCH’

The ‘BRANCH’ event is deprecated in 3.14.  Using *note BRANCH_LEFT: 295.
and *note BRANCH_RIGHT: 296. events will give much better performance as
they can be disabled independently.


File: python.info,  Node: Ancillary events,  Next: Other events,  Prev: Deprecated event,  Up: Events

5.29.2.6 Ancillary events
.........................

Ancillary events can be monitored like other events, but are controlled
by another event:

   * *note C_RAISE: 4922.

   * *note C_RETURN: 4923.

The *note C_RETURN: 4923. and *note C_RAISE: 4922. events are controlled
by the *note CALL: 19a5. event.  *note C_RETURN: 4923. and *note
C_RAISE: 4922. events will only be seen if the corresponding *note CALL:
19a5. event is being monitored.


File: python.info,  Node: Other events,  Next: The STOP_ITERATION event,  Prev: Ancillary events,  Up: Events

5.29.2.7 Other events
.....................

Other events are not necessarily tied to a specific location in the
program and cannot be individually disabled via *note DISABLE: 4937.

The other events that can be monitored are:

   * *note PY_THROW: 183d.

   * *note PY_UNWIND: 492b.

   * *note RAISE: 195c.

   * *note EXCEPTION_HANDLED: 4924.


File: python.info,  Node: The STOP_ITERATION event,  Prev: Other events,  Up: Events

5.29.2.8 The STOP_ITERATION event
.................................

PEP 380(1) specifies that a *note StopIteration: df7. exception is
raised when returning a value from a generator or coroutine.  However,
this is a very inefficient way to return a value, so some Python
implementations, notably CPython 3.12+, do not raise an exception unless
it would be visible to other code.

To allow tools to monitor for real exceptions without slowing down
generators and coroutines, the *note STOP_ITERATION: 492d. event is
provided.  *note STOP_ITERATION: 492d. can be locally disabled, unlike
*note RAISE: 195c.

Note that the *note STOP_ITERATION: 492d. event and the *note RAISE:
195c. event for a *note StopIteration: df7. exception are equivalent,
and are treated as interchangeable when generating events.
Implementations will favor *note STOP_ITERATION: 492d. for performance
reasons, but may generate a *note RAISE: 195c. event with a *note
StopIteration: df7.

   ---------- Footnotes ----------

   (1) 
https://peps.python.org/pep-0380/#use-of-stopiteration-to-return-values


File: python.info,  Node: Turning events on and off,  Next: Registering callback functions,  Prev: Events,  Up: sys monitoring — Execution event monitoring

5.29.2.9 Turning events on and off
..................................

In order to monitor an event, it must be turned on and a corresponding
callback must be registered.  Events can be turned on or off by setting
the events either globally and/or for a particular code object.  An
event will trigger only once, even if it is turned on both globally and
locally.

* Menu:

* Setting events globally::
* Per code object events::
* Disabling events::


File: python.info,  Node: Setting events globally,  Next: Per code object events,  Up: Turning events on and off

5.29.2.10 Setting events globally
.................................

Events can be controlled globally by modifying the set of events being
monitored.

 -- Funzione: sys.monitoring.get_events (tool_id: int, /) -> int

     Returns the ‘int’ representing all the active events.

 -- Funzione: sys.monitoring.set_events (tool_id: int, event_set: int,
          /) -> None

     Activates all events which are set in 'event_set'.  Raises a *note
     ValueError: 2ec. if 'tool_id' is not in use.

No events are active by default.


File: python.info,  Node: Per code object events,  Next: Disabling events,  Prev: Setting events globally,  Up: Turning events on and off

5.29.2.11 Per code object events
................................

Events can also be controlled on a per code object basis.  The functions
defined below which accept a *note types.CodeType: 32f. should be
prepared to accept a look-alike object from functions which are not
defined in Python (see *note Monitoring C API: 486.).

 -- Funzione: sys.monitoring.get_local_events (tool_id: int, code:
          CodeType, /) -> int

     Returns all the *note local events: 4932. for 'code'

 -- Funzione: sys.monitoring.set_local_events (tool_id: int, code:
          CodeType, event_set: int, /) -> None

     Activates all the *note local events: 4932. for 'code' which are
     set in 'event_set'.  Raises a *note ValueError: 2ec. if 'tool_id'
     is not in use.


File: python.info,  Node: Disabling events,  Prev: Per code object events,  Up: Turning events on and off

5.29.2.12 Disabling events
..........................

 -- Dati: sys.monitoring.DISABLE

     A special value that can be returned from a callback function to
     disable events for the current code location.

*note Local events: 4932. can be disabled for a specific code location
by returning *note sys.monitoring.DISABLE: 4937. from a callback
function.  This does not change which events are set, or any other code
locations for the same event.

Disabling events for specific locations is very important for high
performance monitoring.  For example, a program can be run under a
debugger with no overhead if the debugger disables all monitoring except
for a few breakpoints.

If *note DISABLE: 4937. is returned by a callback for a *note global
event: 4935, *note ValueError: 2ec. will be raised by the interpreter in
a non-specific location (that is, no traceback will be provided).

 -- Funzione: sys.monitoring.restart_events () -> None

     Enable all the events that were disabled by *note
     sys.monitoring.DISABLE: 4937. for all tools.


File: python.info,  Node: Registering callback functions,  Prev: Turning events on and off,  Up: sys monitoring — Execution event monitoring

5.29.2.13 Registering callback functions
........................................

 -- Funzione: sys.monitoring.register_callback (tool_id: int, event:
          int, func: Callable | None, /) -> Callable | None

     Registers the callable 'func' for the 'event' with the given
     'tool_id'

     If another callback was registered for the given 'tool_id' and
     'event', it is unregistered and returned.  Otherwise *note
     register_callback(): 4748. returns ‘None’.

     Raises an *note auditing event: 1c56.
     ‘sys.monitoring.register_callback’ with argument ‘func’.

Functions can be unregistered by calling
‘sys.monitoring.register_callback(tool_id, event, None)’.

Callback functions can be registered and unregistered at any time.

Callbacks are called only once regardless if the event is turned on both
globally and locally.  As such, if an event could be turned on for both
global and local events by your code then the callback needs to be
written to handle either trigger.

* Menu:

* Callback function arguments::


File: python.info,  Node: Callback function arguments,  Up: Registering callback functions

5.29.2.14 Callback function arguments
.....................................

 -- Dati: sys.monitoring.MISSING

     A special value that is passed to a callback function to indicate
     that there are no arguments to the call.

When an active event occurs, the registered callback function is called.
Callback functions returning an object other than *note DISABLE: 4937.
will have no effect.  Different events will provide the callback
function with different arguments, as follows:

   * *note PY_START: 492a. and *note PY_RESUME: 4928.:

          func(code: CodeType, instruction_offset: int) -> object

   * *note PY_RETURN: 4929. and *note PY_YIELD: 492c.:

          func(code: CodeType, instruction_offset: int, retval: object) -> object

   * *note CALL: 19a5, *note C_RAISE: 4922. and *note C_RETURN: 4923.
     ('arg0' can be *note MISSING: 4943. specifically):

          func(code: CodeType, instruction_offset: int, callable: object, arg0: object) -> object

     'code' represents the code object where the call is being made,
     while 'callable' is the object that is about to be called (and thus
     triggered the event).  If there are no arguments, 'arg0' is set to
     *note sys.monitoring.MISSING: 4943.

     For instance methods, 'callable' will be the function object as
     found on the class with 'arg0' set to the instance (i.e.  the
     ‘self’ argument to the method).

   * *note RAISE: 195c, *note RERAISE: 492e, *note EXCEPTION_HANDLED:
     4924, *note PY_UNWIND: 492b, *note PY_THROW: 183d. and *note
     STOP_ITERATION: 492d.:

          func(code: CodeType, instruction_offset: int, exception: BaseException) -> object

   * *note LINE: 4927.:

          func(code: CodeType, line_number: int) -> object

   * *note BRANCH_LEFT: 295, *note BRANCH_RIGHT: 296. and *note JUMP:
     4926.:

          func(code: CodeType, instruction_offset: int, destination_offset: int) -> object

     Note that the 'destination_offset' is where the code will next
     execute.

   * *note INSTRUCTION: 4925.:

          func(code: CodeType, instruction_offset: int) -> object


File: python.info,  Node: sysconfig — Provide access to Python’s configuration information,  Next: builtins — Built-in objects,  Prev: sys monitoring — Execution event monitoring,  Up: Python Runtime Services

5.29.3 ‘sysconfig’ — Provide access to Python’s configuration information
-------------------------------------------------------------------------

Added in version 3.2.

'Source code:' Lib/sysconfig(1)

__________________________________________________________________

The *note sysconfig: e1. module provides access to Python’s
configuration information like the list of installation paths and the
configuration variables relevant for the current platform.

* Menu:

* Configuration variables::
* Installation paths::
* User scheme::
* Home scheme::
* Prefix scheme::
* Installation path functions::
* Other functions: Other functions<3>.
* Command-line usage: Command-line usage<6>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/sysconfig


File: python.info,  Node: Configuration variables,  Next: Installation paths,  Up: sysconfig — Provide access to Python’s configuration information

5.29.3.1 Configuration variables
................................

A Python distribution contains a ‘Makefile’ and a ‘pyconfig.h’ header
file that are necessary to build both the Python binary itself and
third-party C extensions compiled using ‘setuptools’.

*note sysconfig: e1. puts all variables found in these files in a
dictionary that can be accessed using *note get_config_vars(): 298. or
*note get_config_var(): 174.

Notice that on Windows, it’s a much smaller set.

 -- Funzione: sysconfig.get_config_vars (*args)

     With no arguments, return a dictionary of all configuration
     variables relevant for the current platform.

     With arguments, return a list of values that result from looking up
     each argument in the configuration variable dictionary.

     For each argument, if the value is not found, return ‘None’.

 -- Funzione: sysconfig.get_config_var (name)

     Return the value of a single variable 'name'.  Equivalent to
     ‘get_config_vars().get(name)’.

     If 'name' is not found, return ‘None’.

Example of usage:

     >>> import sysconfig
     >>> sysconfig.get_config_var('Py_ENABLE_SHARED')
     0
     >>> sysconfig.get_config_var('LIBDIR')
     '/usr/local/lib'
     >>> sysconfig.get_config_vars('AR', 'CXX')
     ['ar', 'g++']


File: python.info,  Node: Installation paths,  Next: User scheme,  Prev: Configuration variables,  Up: sysconfig — Provide access to Python’s configuration information

5.29.3.2 Installation paths
...........................

Python uses an installation scheme that differs depending on the
platform and on the installation options.  These schemes are stored in
*note sysconfig: e1. under unique identifiers based on the value
returned by *note os.name: 2fe8.  The schemes are used by package
installers to determine where to copy files to.

Python currently supports nine schemes:

   - 'posix_prefix': scheme for POSIX platforms like Linux or macOS.
     This is the default scheme used when Python or a component is
     installed.

   - 'posix_home': scheme for POSIX platforms, when the 'home' option is
     used.  This scheme defines paths located under a specific home
     prefix.

   - 'posix_user': scheme for POSIX platforms, when the 'user' option is
     used.  This scheme defines paths located under the user’s home
     directory (*note site.USER_BASE: 1524.).

   - 'posix_venv': scheme for *note Python virtual environments: 117. on
     POSIX platforms; by default it is the same as 'posix_prefix'.

   - 'nt': scheme for Windows.  This is the default scheme used when
     Python or a component is installed.

   - 'nt_user': scheme for Windows, when the 'user' option is used.

   - 'nt_venv': scheme for *note Python virtual environments: 117. on
     Windows; by default it is the same as 'nt'.

   - 'venv': a scheme with values from either 'posix_venv' or 'nt_venv'
     depending on the platform Python runs on.

   - 'osx_framework_user': scheme for macOS, when the 'user' option is
     used.

Each scheme is itself composed of a series of paths and each path has a
unique identifier.  Python currently uses eight paths:

   - 'stdlib': directory containing the standard Python library files
     that are not platform-specific.

   - 'platstdlib': directory containing the standard Python library
     files that are platform-specific.

   - 'platlib': directory for site-specific, platform-specific files.

   - 'purelib': directory for site-specific, non-platform-specific files
     (“pure” Python).

   - 'include': directory for non-platform-specific header files for the
     Python C-API.

   - 'platinclude': directory for platform-specific header files for the
     Python C-API.

   - 'scripts': directory for script files.

   - 'data': directory for data files.


File: python.info,  Node: User scheme,  Next: Home scheme,  Prev: Installation paths,  Up: sysconfig — Provide access to Python’s configuration information

5.29.3.3 User scheme
....................

This scheme is designed to be the most convenient solution for users
that don’t have write permission to the global site-packages directory
or don’t want to install into it.

Files will be installed into subdirectories of *note site.USER_BASE:
1524. (written as ‘`userbase'’ hereafter).  This scheme installs pure
Python modules and extension modules in the same location (also known as
*note site.USER_SITE: 210f.).

* Menu:

* posix_user::
* nt_user::
* osx_framework_user::


File: python.info,  Node: posix_user,  Next: nt_user,  Up: User scheme

5.29.3.4 ‘posix_user’
.....................

Path               Installation directory
                   
-----------------------------------------------------------------------------------
                   
'stdlib'           ‘`userbase'/lib/python`X.Y'’
                   
                   
'platstdlib'       ‘`userbase'/lib/python`X.Y'’
                   
                   
'platlib'          ‘`userbase'/lib/python`X.Y'/site-packages’
                   
                   
'purelib'          ‘`userbase'/lib/python`X.Y'/site-packages’
                   
                   
'include'          ‘`userbase'/include/python`X.Y'’
                   
                   
'scripts'          ‘`userbase'/bin’
                   
                   
'data'             ‘`userbase'’
                   


File: python.info,  Node: nt_user,  Next: osx_framework_user,  Prev: posix_user,  Up: User scheme

5.29.3.5 ‘nt_user’
..................

Path               Installation directory
                   
-----------------------------------------------------------------------------------
                   
'stdlib'           ‘`userbase'\Python`XY'’
                   
                   
'platstdlib'       ‘`userbase'\Python`XY'’
                   
                   
'platlib'          ‘`userbase'\Python`XY'\site-packages’
                   
                   
'purelib'          ‘`userbase'\Python`XY'\site-packages’
                   
                   
'include'          ‘`userbase'\Python`XY'\Include’
                   
                   
'scripts'          ‘`userbase'\Python`XY'\Scripts’
                   
                   
'data'             ‘`userbase'’
                   


File: python.info,  Node: osx_framework_user,  Prev: nt_user,  Up: User scheme

5.29.3.6 ‘osx_framework_user’
.............................

Path               Installation directory
                   
-----------------------------------------------------------------------------------
                   
'stdlib'           ‘`userbase'/lib/python’
                   
                   
'platstdlib'       ‘`userbase'/lib/python’
                   
                   
'platlib'          ‘`userbase'/lib/python/site-packages’
                   
                   
'purelib'          ‘`userbase'/lib/python/site-packages’
                   
                   
'include'          ‘`userbase'/include/python`X.Y'’
                   
                   
'scripts'          ‘`userbase'/bin’
                   
                   
'data'             ‘`userbase'’
                   


File: python.info,  Node: Home scheme,  Next: Prefix scheme,  Prev: User scheme,  Up: sysconfig — Provide access to Python’s configuration information

5.29.3.7 Home scheme
....................

The idea behind the «home scheme» is that you build and maintain a
personal stash of Python modules.  This scheme’s name is derived from
the idea of a «home» directory on Unix, since it’s not unusual for a
Unix user to make their home directory have a layout similar to ‘/usr/’
or ‘/usr/local/’.  This scheme can be used by anyone, regardless of the
operating system they are installing for.

* Menu:

* posix_home::


File: python.info,  Node: posix_home,  Up: Home scheme

5.29.3.8 ‘posix_home’
.....................

Path               Installation directory
                   
-----------------------------------------------------------------------------------
                   
'stdlib'           ‘`home'/lib/python’
                   
                   
'platstdlib'       ‘`home'/lib/python’
                   
                   
'platlib'          ‘`home'/lib/python’
                   
                   
'purelib'          ‘`home'/lib/python’
                   
                   
'include'          ‘`home'/include/python’
                   
                   
'platinclude'      ‘`home'/include/python’
                   
                   
'scripts'          ‘`home'/bin’
                   
                   
'data'             ‘`home'’
                   


File: python.info,  Node: Prefix scheme,  Next: Installation path functions,  Prev: Home scheme,  Up: sysconfig — Provide access to Python’s configuration information

5.29.3.9 Prefix scheme
......................

The «prefix scheme» is useful when you wish to use one Python
installation to perform the build/install (i.e., to run the setup
script), but install modules into the third-party module directory of a
different Python installation (or something that looks like a different
Python installation).  If this sounds a trifle unusual, it is—that’s why
the user and home schemes come before.  However, there are at least two
known cases where the prefix scheme will be useful.

First, consider that many Linux distributions put Python in ‘/usr’,
rather than the more traditional ‘/usr/local’.  This is entirely
appropriate, since in those cases Python is part of «the system» rather
than a local add-on.  However, if you are installing Python modules from
source, you probably want them to go in ‘/usr/local/lib/python2.`X'’
rather than ‘/usr/lib/python2.`X'’.

Another possibility is a network filesystem where the name used to write
to a remote directory is different from the name used to read it: for
example, the Python interpreter accessed as ‘/usr/local/bin/python’
might search for modules in ‘/usr/local/lib/python2.`X'’, but those
modules would have to be installed to, say,
‘/mnt/`@server'/export/lib/python2.`X'’.

* Menu:

* posix_prefix::
* nt::


File: python.info,  Node: posix_prefix,  Next: nt,  Up: Prefix scheme

5.29.3.10 ‘posix_prefix’
........................

Path               Installation directory
                   
----------------------------------------------------------------------------------
                   
'stdlib'           ‘`prefix'/lib/python`X.Y'’
                   
                   
'platstdlib'       ‘`prefix'/lib/python`X.Y'’
                   
                   
'platlib'          ‘`prefix'/lib/python`X.Y'/site-packages’
                   
                   
'purelib'          ‘`prefix'/lib/python`X.Y'/site-packages’
                   
                   
'include'          ‘`prefix'/include/python`X.Y'’
                   
                   
'platinclude'      ‘`prefix'/include/python`X.Y'’
                   
                   
'scripts'          ‘`prefix'/bin’
                   
                   
'data'             ‘`prefix'’
                   


File: python.info,  Node: nt,  Prev: posix_prefix,  Up: Prefix scheme

5.29.3.11 ‘nt’
..............

Path               Installation directory
                   
----------------------------------------------------------------------------------
                   
'stdlib'           ‘`prefix'\Lib’
                   
                   
'platstdlib'       ‘`prefix'\Lib’
                   
                   
'platlib'          ‘`prefix'\Lib\site-packages’
                   
                   
'purelib'          ‘`prefix'\Lib\site-packages’
                   
                   
'include'          ‘`prefix'\Include’
                   
                   
'platinclude'      ‘`prefix'\Include’
                   
                   
'scripts'          ‘`prefix'\Scripts’
                   
                   
'data'             ‘`prefix'’
                   


File: python.info,  Node: Installation path functions,  Next: Other functions<3>,  Prev: Prefix scheme,  Up: sysconfig — Provide access to Python’s configuration information

5.29.3.12 Installation path functions
.....................................

*note sysconfig: e1. provides some functions to determine these
installation paths.

 -- Funzione: sysconfig.get_scheme_names ()

     Return a tuple containing all schemes currently supported in *note
     sysconfig: e1.

 -- Funzione: sysconfig.get_default_scheme ()

     Return the default scheme name for the current platform.

     Added in version 3.10: This function was previously named
     ‘_get_default_scheme()’ and considered an implementation detail.

     Cambiato nella versione 3.11: When Python runs from a virtual
     environment, the 'venv' scheme is returned.

 -- Funzione: sysconfig.get_preferred_scheme (key)

     Return a preferred scheme name for an installation layout specified
     by 'key'.

     'key' must be either ‘"prefix"’, ‘"home"’, or ‘"user"’.

     The return value is a scheme name listed in *note
     get_scheme_names(): 4955.  It can be passed to *note sysconfig: e1.
     functions that take a 'scheme' argument, such as *note get_paths():
     340.

     Added in version 3.10.

     Cambiato nella versione 3.11: When Python runs from a virtual
     environment and ‘key="prefix"’, the 'venv' scheme is returned.

 -- Funzione: sysconfig._get_preferred_schemes ()

     Return a dict containing preferred scheme names on the current
     platform.  Python implementers and redistributors may add their
     preferred schemes to the ‘_INSTALL_SCHEMES’ module-level global
     value, and modify this function to return those scheme names, to
     e.g.  provide different schemes for system and language package
     managers to use, so packages installed by either do not mix with
     those by the other.

     End users should not use this function, but *note
     get_default_scheme(): 1b9d. and *note get_preferred_scheme(): 8a0.
     instead.

     Added in version 3.10.

 -- Funzione: sysconfig.get_path_names ()

     Return a tuple containing all path names currently supported in
     *note sysconfig: e1.

 -- Funzione: sysconfig.get_path (name[, scheme[, vars[, expand]]])

     Return an installation path corresponding to the path 'name', from
     the install scheme named 'scheme'.

     'name' has to be a value from the list returned by *note
     get_path_names(): 4957.

     *note sysconfig: e1. stores installation paths corresponding to
     each path name, for each platform, with variables to be expanded.
     For instance the 'stdlib' path for the 'nt' scheme is:
     ‘{base}/Lib’.

     *note get_path(): 1535. will use the variables returned by *note
     get_config_vars(): 298. to expand the path.  All variables have
     default values for each platform so one may call this function and
     get the default value.

     If 'scheme' is provided, it must be a value from the list returned
     by *note get_scheme_names(): 4955.  Otherwise, the default scheme
     for the current platform is used.

     If 'vars' is provided, it must be a dictionary of variables that
     will update the dictionary returned by *note get_config_vars():
     298.

     If 'expand' is set to ‘False’, the path will not be expanded using
     the variables.

     If 'name' is not found, raise a *note KeyError: 5e7.

 -- Funzione: sysconfig.get_paths ([scheme[, vars[, expand]]])

     Return a dictionary containing all installation paths corresponding
     to an installation scheme.  See *note get_path(): 1535. for more
     information.

     If 'scheme' is not provided, will use the default scheme for the
     current platform.

     If 'vars' is provided, it must be a dictionary of variables that
     will update the dictionary used to expand the paths.

     If 'expand' is set to false, the paths will not be expanded.

     If 'scheme' is not an existing scheme, *note get_paths(): 340. will
     raise a *note KeyError: 5e7.


File: python.info,  Node: Other functions<3>,  Next: Command-line usage<6>,  Prev: Installation path functions,  Up: sysconfig — Provide access to Python’s configuration information

5.29.3.13 Other functions
.........................

 -- Funzione: sysconfig.get_python_version ()

     Return the ‘MAJOR.MINOR’ Python version number as a string.
     Similar to ‘'%d.%d' % sys.version_info[:2]’.

 -- Funzione: sysconfig.get_platform ()

     Return a string that identifies the current platform.

     This is used mainly to distinguish platform-specific build
     directories and platform-specific built distributions.  Typically
     includes the OS name and version and the architecture (as supplied
     by *note os.uname(): 131e.), although the exact information
     included depends on the OS; e.g., on Linux, the kernel version
     isn’t particularly important.

     Examples of returned values:

     Windows:

        - win-amd64 (64-bit Windows on AMD64, aka x86_64, Intel64, and
          EM64T)

        - win-arm64 (64-bit Windows on ARM64, aka AArch64)

        - win32 (all others - specifically, sys.platform is returned)

     POSIX based OS:

        - linux-x86_64

        - macosx-15.5-arm64

        - macosx-26.0-universal2 (macOS on Apple Silicon or Intel)

        - android-24-arm64_v8a

     For other non-POSIX platforms, currently just returns *note
     sys.platform: 291.

 -- Funzione: sysconfig.is_python_build ()

     Return ‘True’ if the running Python interpreter was built from
     source and is being run from its built location, and not from a
     location resulting from e.g.  running ‘make install’ or installing
     via a binary installer.

 -- Funzione: sysconfig.parse_config_h (fp[, vars])

     Parse a ‘config.h’-style file.

     'fp' is a file-like object pointing to the ‘config.h’-like file.

     A dictionary containing name/value pairs is returned.  If an
     optional dictionary is passed in as the second argument, it is used
     instead of a new dictionary, and updated with the values read in
     the file.

 -- Funzione: sysconfig.get_config_h_filename ()

     Return the path of ‘pyconfig.h’.

 -- Funzione: sysconfig.get_makefile_filename ()

     Return the path of ‘Makefile’.


File: python.info,  Node: Command-line usage<6>,  Prev: Other functions<3>,  Up: sysconfig — Provide access to Python’s configuration information

5.29.3.14 Command-line usage
............................

You can use *note sysconfig: e1. as a script with Python’s '-m' option:

     $ python -m sysconfig
     Platform: "macosx-10.4-i386"
     Python version: "3.2"
     Current installation scheme: "posix_prefix"

     Paths:
             data = "/usr/local"
             include = "/Users/tarek/Dev/svn.python.org/py3k/Include"
             platinclude = "."
             platlib = "/usr/local/lib/python3.2/site-packages"
             platstdlib = "/usr/local/lib/python3.2"
             purelib = "/usr/local/lib/python3.2/site-packages"
             scripts = "/usr/local/bin"
             stdlib = "/usr/local/lib/python3.2"

     Variables:
             AC_APPLE_UNIVERSAL_BUILD = "0"
             AIX_GENUINE_CPLUSPLUS = "0"
             AR = "ar"
             ARFLAGS = "rc"
             ...

This call will print in the standard output the information returned by
*note get_platform(): 144a, *note get_python_version(): 144b, *note
get_path(): 1535. and *note get_config_vars(): 298.


File: python.info,  Node: builtins — Built-in objects,  Next: __main__ — Top-level code environment,  Prev: sysconfig — Provide access to Python’s configuration information,  Up: Python Runtime Services

5.29.4 ‘builtins’ — Built-in objects
------------------------------------

__________________________________________________________________

This module provides direct access to all “built-in” identifiers of
Python; for example, ‘builtins.open’ is the full name for the built-in
function *note open(): 316.

This module is not normally accessed explicitly by most applications,
but can be useful in modules that provide objects with the same name as
a built-in value, but in which the built-in of that name is also needed.
For example, in a module that wants to implement an *note open(): 316.
function that wraps the built-in *note open(): 316, this module can be
used directly:

     import builtins

     def open(path):
         f = builtins.open(path, 'r')
         return UpperCaser(f)

     class UpperCaser:
         '''Wrapper around a file that converts output to uppercase.'''

         def __init__(self, f):
             self._f = f

         def read(self, count=-1):
             return self._f.read(count).upper()

         # ...

As an implementation detail, most modules have the name ‘__builtins__’
made available as part of their globals.  The value of ‘__builtins__’ is
normally either this module or the value of this module’s *note
__dict__: 77e. attribute.  Since this is an implementation detail, it
may not be used by alternate implementations of Python.

Vedi anche
..........

   * *note Built-in Constants: 25c1.

   * *note Built-in Exceptions: 1c0f.

   * *note Funzioni Incorporate: 1464.

   * *note Tipi incorporati: 25c8.


File: python.info,  Node: __main__ — Top-level code environment,  Next: warnings — Warning control,  Prev: builtins — Built-in objects,  Up: Python Runtime Services

5.29.5 ‘__main__’ — Top-level code environment
----------------------------------------------

__________________________________________________________________

In Python, the special name ‘__main__’ is used for two important
constructs:

  1. the name of the top-level environment of the program, which can be
     checked using the ‘__name__ == '__main__'’ expression; and

  2. the ‘__main__.py’ file in Python packages.

Both of these mechanisms are related to Python modules; how users
interact with them and how they interact with each other.  They are
explained in detail below.  If you’re new to Python modules, see the
tutorial section *note Moduli: 2028. for an introduction.

* Menu:

* __name__ == '__main__'::
* __main__.py in Python Packages: __main__ py in Python Packages.
* import __main__::


File: python.info,  Node: __name__ == '__main__',  Next: __main__ py in Python Packages,  Up: __main__ — Top-level code environment

5.29.5.1 ‘__name__ == '__main__'’
.................................

When a Python module or package is imported, ‘__name__’ is set to the
module’s name.  Usually, this is the name of the Python file itself
without the ‘.py’ extension:

     >>> import configparser
     >>> configparser.__name__
     'configparser'

If the file is part of a package, ‘__name__’ will also include the
parent package’s path:

     >>> from concurrent.futures import process
     >>> process.__name__
     'concurrent.futures.process'

However, if the module is executed in the top-level code environment,
its ‘__name__’ is set to the string ‘'__main__'’.

* Menu:

* What is the «top-level code environment»?::
* Idiomatic Usage::
* Packaging Considerations::


File: python.info,  Node: What is the «top-level code environment»?,  Next: Idiomatic Usage,  Up: __name__ == '__main__'

5.29.5.2 What is the «top-level code environment»?
..................................................

‘__main__’ is the name of the environment where top-level code is run.
«Top-level code» is the first user-specified Python module that starts
running.  It’s «top-level» because it imports all other modules that the
program needs.  Sometimes «top-level code» is called an 'entry point' to
the application.

The top-level code environment can be:

   * the scope of an interactive prompt:

          >>> __name__
          '__main__'

   * the Python module passed to the Python interpreter as a file
     argument:

          $ python helloworld.py
          Hello, world!

   * the Python module or package passed to the Python interpreter with
     the *note -m: 23c. argument:

          $ python -m tarfile
          usage: tarfile.py [-h] [-v] (...)

   * Python code read by the Python interpreter from standard input:

          $ echo "import this" | python
          The Zen of Python, by Tim Peters

          Beautiful is better than ugly.
          Explicit is better than implicit.
          ...

   * Python code passed to the Python interpreter with the *note -c:
     1a8. argument:

          $ python -c "import this"
          The Zen of Python, by Tim Peters

          Beautiful is better than ugly.
          Explicit is better than implicit.
          ...

In each of these situations, the top-level module’s ‘__name__’ is set to
‘'__main__'’.

As a result, a module can discover whether or not it is running in the
top-level environment by checking its own ‘__name__’, which allows a
common idiom for conditionally executing code when the module is not
initialized from an import statement:

     if __name__ == '__main__':
         # Execute when the module is not initialized from an import statement.
         ...

Vedi anche
..........

For a more detailed look at how ‘__name__’ is set in all situations, see
the tutorial section *note Moduli: 2028.


File: python.info,  Node: Idiomatic Usage,  Next: Packaging Considerations,  Prev: What is the «top-level code environment»?,  Up: __name__ == '__main__'

5.29.5.3 Idiomatic Usage
........................

Some modules contain code that is intended for script use only, like
parsing command-line arguments or fetching data from standard input.  If
a module like this was imported from a different module, for example to
unit test it, the script code would unintentionally execute as well.

This is where using the ‘if __name__ == '__main__'’ code block comes in
handy.  Code within this block won’t run unless the module is executed
in the top-level environment.

Putting as few statements as possible in the block below ‘if __name__ ==
'__main__'’ can improve code clarity and correctness.  Most often, a
function named ‘main’ encapsulates the program’s primary behavior:

     # echo.py

     import shlex
     import sys

     def echo(phrase: str) -> None:
        """A dummy wrapper around print."""
        # for demonstration purposes, you can imagine that there is some
        # valuable and reusable logic inside this function
        print(phrase)

     def main() -> int:
         """Echo the input arguments to standard output"""
         phrase = shlex.join(sys.argv)
         echo(phrase)
         return 0

     if __name__ == '__main__':
         sys.exit(main())  # next section explains the use of sys.exit

Note that if the module didn’t encapsulate code inside the ‘main’
function but instead put it directly within the ‘if __name__ ==
'__main__'’ block, the ‘phrase’ variable would be global to the entire
module.  This is error-prone as other functions within the module could
be unintentionally using the global variable instead of a local name.  A
‘main’ function solves this problem.

Using a ‘main’ function has the added benefit of the ‘echo’ function
itself being isolated and importable elsewhere.  When ‘echo.py’ is
imported, the ‘echo’ and ‘main’ functions will be defined, but neither
of them will be called, because ‘__name__ != '__main__'’.


File: python.info,  Node: Packaging Considerations,  Prev: Idiomatic Usage,  Up: __name__ == '__main__'

5.29.5.4 Packaging Considerations
.................................

‘main’ functions are often used to create command-line tools by
specifying them as entry points for console scripts.  When this is done,
pip(1) inserts the function call into a template script, where the
return value of ‘main’ is passed into *note sys.exit(): 277.  For
example:

     sys.exit(main())

Since the call to ‘main’ is wrapped in *note sys.exit(): 277, the
expectation is that your function will return some value acceptable as
an input to *note sys.exit(): 277.; typically, an integer or ‘None’
(which is implicitly returned if your function does not have a return
statement).

By proactively following this convention ourselves, our module will have
the same behavior when run directly (i.e.  ‘python echo.py’) as it will
have if we later package it as a console script entry-point in a
pip-installable package.

In particular, be careful about returning strings from your ‘main’
function.  *note sys.exit(): 277. will interpret a string argument as a
failure message, so your program will have an exit code of ‘1’,
indicating failure, and the string will be written to *note sys.stderr:
b35.  The ‘echo.py’ example from earlier exemplifies using the
‘sys.exit(main())’ convention.

Vedi anche
..........

Python Packaging User Guide(2) contains a collection of tutorials and
references on how to distribute and install Python packages with modern
tools.

   ---------- Footnotes ----------

   (1) https://pip.pypa.io/

   (2) https://packaging.python.org/


File: python.info,  Node: __main__ py in Python Packages,  Next: import __main__,  Prev: __name__ == '__main__',  Up: __main__ — Top-level code environment

5.29.5.5 ‘__main__.py’ in Python Packages
.........................................

If you are not familiar with Python packages, see section *note
Pacchetti: 2038. of the tutorial.  Most commonly, the ‘__main__.py’ file
is used to provide a command-line interface for a package.  Consider the
following hypothetical package, «bandclass»:

     bandclass
       ├── __init__.py
       ├── __main__.py
       └── student.py

‘__main__.py’ will be executed when the package itself is invoked
directly from the command line using the *note -m: 23c. flag.  For
example:

     $ python -m bandclass

This command will cause ‘__main__.py’ to run.  How you utilize this
mechanism will depend on the nature of the package you are writing, but
in this hypothetical case, it might make sense to allow the teacher to
search for students:

     # bandclass/__main__.py

     import sys
     from .student import search_students

     student_name = sys.argv[1] if len(sys.argv) >= 2 else ''
     print(f'Found student: {search_students(student_name)}')

Note that ‘from .student import search_students’ is an example of a
relative import.  This import style can be used when referencing modules
within a package.  For more details, see *note Riferimenti
Intra-pacchetto: 203c. in the *note Moduli: 2028. section of the
tutorial.

* Menu:

* Idiomatic Usage: Idiomatic Usage<2>.


File: python.info,  Node: Idiomatic Usage<2>,  Up: __main__ py in Python Packages

5.29.5.6 Idiomatic Usage
........................

The content of ‘__main__.py’ typically isn’t fenced with an ‘if __name__
== '__main__'’ block.  Instead, those files are kept short and import
functions to execute from other modules.  Those other modules can then
be easily unit-tested and are properly reusable.

If used, an ‘if __name__ == '__main__'’ block will still work as
expected for a ‘__main__.py’ file within a package, because its
‘__name__’ attribute will include the package’s path if imported:

     >>> import asyncio.__main__
     >>> asyncio.__main__.__name__
     'asyncio.__main__'

This won’t work for ‘__main__.py’ files in the root directory of a
‘.zip’ file though.  Hence, for consistency, a minimal ‘__main__.py’
without a ‘__name__’ check is preferred.

Vedi anche
..........

See *note venv: 117. for an example of a package with a minimal
‘__main__.py’ in the standard library.  It doesn’t contain a ‘if
__name__ == '__main__'’ block.  You can invoke it with ‘python -m venv
[directory]’.

See *note runpy: c3. for more details on the *note -m: 23c. flag to the
interpreter executable.

See *note zipapp: 136. for how to run applications packaged as '.zip'
files.  In this case Python looks for a ‘__main__.py’ file in the root
directory of the archive.


File: python.info,  Node: import __main__,  Prev: __main__ py in Python Packages,  Up: __main__ — Top-level code environment

5.29.5.7 ‘import __main__’
..........................

Regardless of which module a Python program was started with, other
modules running within that same program can import the top-level
environment’s scope (*note namespace: 2029.) by importing the ‘__main__’
module.  This doesn’t import a ‘__main__.py’ file but rather whichever
module that received the special name ‘'__main__'’.

Here is an example module that consumes the ‘__main__’ namespace:

     # namely.py

     import __main__

     def did_user_define_their_name():
         return 'my_name' in dir(__main__)

     def print_user_name():
         if not did_user_define_their_name():
             raise ValueError('Define the variable `my_name`!')

         print(__main__.my_name)

Example usage of this module could be as follows:

     # start.py

     import sys

     from namely import print_user_name

     # my_name = "Dinsdale"

     def main():
         try:
             print_user_name()
         except ValueError as ve:
             return str(ve)

     if __name__ == "__main__":
         sys.exit(main())

Now, if we started our program, the result would look like this:

     $ python start.py
     Define the variable `my_name`!

The exit code of the program would be 1, indicating an error.
Uncommenting the line with ‘my_name = "Dinsdale"’ fixes the program and
now it exits with status code 0, indicating success:

     $ python start.py
     Dinsdale

Note that importing ‘__main__’ doesn’t cause any issues with
unintentionally running top-level code meant for script use which is put
in the ‘if __name__ == "__main__"’ block of the ‘start’ module.  Why
does this work?

Python inserts an empty ‘__main__’ module in *note sys.modules: 17ce. at
interpreter startup, and populates it by running top-level code.  In our
example this is the ‘start’ module which runs line by line and imports
‘namely’.  In turn, ‘namely’ imports ‘__main__’ (which is really
‘start’).  That’s an import cycle!  Fortunately, since the partially
populated ‘__main__’ module is present in *note sys.modules: 17ce,
Python passes that to ‘namely’.  See *note Special considerations for
__main__: 2442. in the import system’s reference for details on how this
works.

The Python REPL is another example of a «top-level environment», so
anything defined in the REPL becomes part of the ‘__main__’ scope:

     >>> import namely
     >>> namely.did_user_define_their_name()
     False
     >>> namely.print_user_name()
     Traceback (most recent call last):
     ...
     ValueError: Define the variable `my_name`!
     >>> my_name = 'Jabberwocky'
     >>> namely.did_user_define_their_name()
     True
     >>> namely.print_user_name()
     Jabberwocky

The ‘__main__’ scope is used in the implementation of *note pdb: aa. and
*note rlcompleter: c2.


File: python.info,  Node: warnings — Warning control,  Next: dataclasses — Data Classes,  Prev: __main__ — Top-level code environment,  Up: Python Runtime Services

5.29.6 ‘warnings’ — Warning control
-----------------------------------

'Source code:' Lib/warnings.py(1)

__________________________________________________________________

Warning messages are typically issued in situations where it is useful
to alert the user of some condition in a program, where that condition
(normally) doesn’t warrant raising an exception and terminating the
program.  For example, one might want to issue a warning when a program
uses an obsolete module.

Python programmers issue warnings by calling the *note warn(): 1720.
function defined in this module.  (C programmers use *note
PyErr_WarnEx(): 1653.; see *note Exception Handling: 4970. for details).

Warning messages are normally written to *note sys.stderr: b35, but
their disposition can be changed flexibly, from ignoring all warnings to
turning them into exceptions.  The disposition of warnings can vary
based on the *note warning category: 26f4, the text of the warning
message, and the source location where it is issued.  Repetitions of a
particular warning for the same source location are typically
suppressed.

There are two stages in warning control: first, each time a warning is
issued, a determination is made whether a message should be issued or
not; next, if a message is to be issued, it is formatted and printed
using a user-settable hook.

The determination whether to issue a warning message is controlled by
the *note warning filter: 1b1, which is a sequence of matching rules and
actions.  Rules can be added to the filter by calling *note
filterwarnings(): 16b0. and reset to its default state by calling *note
resetwarnings(): 4971.

The printing of warning messages is done by calling *note showwarning():
4972, which may be overridden; the default implementation of this
function formats the message by calling *note formatwarning(): 1de0,
which is also available for use by custom implementations.

Vedi anche
..........

*note logging.captureWarnings(): 318a. allows you to handle all warnings
with the standard logging infrastructure.

* Menu:

* Warning Categories::
* The Warnings Filter::
* Temporarily Suppressing Warnings::
* Testing Warnings::
* Updating Code For New Versions of Dependencies::
* Available Functions::
* Available Context Managers::
* Concurrent safety of Context Managers::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/warnings.py


File: python.info,  Node: Warning Categories,  Next: The Warnings Filter,  Up: warnings — Warning control

5.29.6.1 Warning Categories
...........................

There are a number of built-in exceptions that represent warning
categories.  This categorization is useful to be able to filter out
groups of warnings.

While these are technically *note built-in exceptions: 26f2, they are
documented here, because conceptually they belong to the warnings
mechanism.

User code can define additional warning categories by subclassing one of
the standard warning categories.  A warning category must always be a
subclass of the *note Warning: 26f5. class.

The following warnings category classes are currently defined:

Class                                  Description
                                       
-------------------------------------------------------------------------------------------
                                       
*note Warning: 26f5.                   This is the base class of all warning category
                                       classes.  It is a subclass of
                                       *note Exception: bcf.
                                       
                                       
*note UserWarning: 26f6.               The default category for *note warn(): 1720.
                                       
                                       
*note DeprecationWarning: 1a3.         Base category for warnings about deprecated
                                       features when those warnings are intended for
                                       other Python developers (ignored by default,
                                       unless triggered by code in ‘__main__’).
                                       
                                       
*note SyntaxWarning: 1ae.              Base category for warnings about dubious
                                       syntactic features (typically emitted when
                                       compiling Python source code, and hence may not
                                       be suppressed by runtime filters)
                                       
                                       
*note RuntimeWarning: 4d8.             Base category for warnings about dubious runtime
                                       features.
                                       
                                       
*note FutureWarning: 659.              Base category for warnings about deprecated
                                       features when those warnings are intended for end
                                       users of applications that are written in Python.
                                       
                                       
*note PendingDeprecationWarning: ac8.  Base category for warnings about features that
                                       will be deprecated in the future (ignored by
                                       default).
                                       
                                       
*note ImportWarning: 71f.              Base category for warnings triggered during the
                                       process of importing a module (ignored by
                                       default).
                                       
                                       
*note UnicodeWarning: 162b.            Base category for warnings related to Unicode.
                                       
                                       
*note BytesWarning: e1e.               Base category for warnings related to
                                       *note bytes: 192. and *note bytearray: 344.
                                       
                                       
*note ResourceWarning: 54d.            Base category for warnings related to resource
                                       usage (ignored by default).
                                       

Cambiato nella versione 3.7: Previously *note DeprecationWarning: 1a3.
and *note FutureWarning: 659. were distinguished based on whether a
feature was being removed entirely or changing its behaviour.  They are
now distinguished based on their intended audience and the way they’re
handled by the default warnings filters.


File: python.info,  Node: The Warnings Filter,  Next: Temporarily Suppressing Warnings,  Prev: Warning Categories,  Up: warnings — Warning control

5.29.6.2 The Warnings Filter
............................

The warnings filter controls whether warnings are ignored, displayed, or
turned into errors (raising an exception).

Conceptually, the warnings filter maintains an ordered list of filter
specifications; any specific warning is matched against each filter
specification in the list in turn until a match is found; the filter
determines the disposition of the match.  Each entry is a tuple of the
form ('action', 'message', 'category', 'module', 'lineno'), where:

   * 'action' is one of the following strings:

     Value               Disposition
                         
     -----------------------------------------------------------------------
                         
     ‘"default"’         print the first occurrence of matching warnings
                         for each location (module + line number) where
                         the warning is issued
                         
                         
     ‘"error"’           turn matching warnings into exceptions
                         
                         
     ‘"ignore"’          never print matching warnings
                         
                         
     ‘"always"’          always print matching warnings
                         
                         
     ‘"all"’             alias to «always»
                         
                         
     ‘"module"’          print the first occurrence of matching warnings
                         for each module where the warning is issued
                         (regardless of line number)
                         
                         
     ‘"once"’            print only the first occurrence of matching
                         warnings, regardless of location
                         

   * 'message' is a string containing a regular expression that the
     start of the warning message must match, case-insensitively.  In
     *note -W: ac7. and *note PYTHONWARNINGS: da5, 'message' is a
     literal string that the start of the warning message must contain
     (case-insensitively), ignoring any whitespace at the start or end
     of 'message'.

   * 'category' is a class (a subclass of *note Warning: 26f5.) of which
     the warning category must be a subclass in order to match.

   * 'module' is a string containing a regular expression that the start
     of the fully qualified module name must match, case-sensitively.
     In *note -W: ac7. and *note PYTHONWARNINGS: da5, 'module' is a
     literal string that the fully qualified module name must be equal
     to (case-sensitively), ignoring any whitespace at the start or end
     of 'module'.

   * 'lineno' is an integer that the line number where the warning
     occurred must match, or ‘0’ to match all line numbers.

Since the *note Warning: 26f5. class is derived from the built-in *note
Exception: bcf. class, to turn a warning into an error we simply raise
‘category(message)’.

If a warning is reported and doesn’t match any registered filter then
the «default» action is applied (hence its name).

* Menu:

* Repeated Warning Suppression Criteria::
* Describing Warning Filters::
* Default Warning Filter::
* Overriding the default filter::


File: python.info,  Node: Repeated Warning Suppression Criteria,  Next: Describing Warning Filters,  Up: The Warnings Filter

5.29.6.3 Repeated Warning Suppression Criteria
..............................................

The filters that suppress repeated warnings apply the following criteria
to determine if a warning is considered a repeat:

   - ‘"default"’: A warning is considered a repeat only if the
     ('message', 'category', 'module', 'lineno') are all the same.

   - ‘"module"’: A warning is considered a repeat if the ('message',
     'category', 'module') are the same, ignoring the line number.

   - ‘"once"’: A warning is considered a repeat if the ('message',
     'category') are the same, ignoring the module and line number.


File: python.info,  Node: Describing Warning Filters,  Next: Default Warning Filter,  Prev: Repeated Warning Suppression Criteria,  Up: The Warnings Filter

5.29.6.4 Describing Warning Filters
...................................

The warnings filter is initialized by *note -W: ac7. options passed to
the Python interpreter command line and the *note PYTHONWARNINGS: da5.
environment variable.  The interpreter saves the arguments for all
supplied entries without interpretation in *note sys.warnoptions: 3f5.;
the *note warnings: 118. module parses these when it is first imported
(invalid options are ignored, after printing a message to *note
sys.stderr: b35.).

Individual warnings filters are specified as a sequence of fields
separated by colons:

     action:message:category:module:line

The meaning of each of these fields is as described in *note The
Warnings Filter: 1b1.  When listing multiple filters on a single line
(as for *note PYTHONWARNINGS: da5.), the individual filters are
separated by commas and the filters listed later take precedence over
those listed before them (as they’re applied left-to-right, and the most
recently applied filters take precedence over earlier ones).

Commonly used warning filters apply to either all warnings, warnings in
a particular category, or warnings raised by particular modules or
packages.  Some examples:

     default                      # Show all warnings (even those ignored by default)
     ignore                       # Ignore all warnings
     error                        # Convert all warnings to errors
     error::ResourceWarning       # Treat ResourceWarning messages as errors
     default::DeprecationWarning  # Show DeprecationWarning messages
     ignore,default:::mymodule    # Only report warnings triggered by "mymodule"
     error:::mymodule             # Convert warnings to errors in "mymodule"


File: python.info,  Node: Default Warning Filter,  Next: Overriding the default filter,  Prev: Describing Warning Filters,  Up: The Warnings Filter

5.29.6.5 Default Warning Filter
...............................

By default, Python installs several warning filters, which can be
overridden by the *note -W: ac7. command-line option, the *note
PYTHONWARNINGS: da5. environment variable and calls to *note
filterwarnings(): 16b0.

In regular release builds, the default warning filter has the following
entries (in order of precedence):

     default::DeprecationWarning:__main__
     ignore::DeprecationWarning
     ignore::PendingDeprecationWarning
     ignore::ImportWarning
     ignore::ResourceWarning

In a *note debug build: 50a, the list of default warning filters is
empty.

Cambiato nella versione 3.2: *note DeprecationWarning: 1a3. is now
ignored by default in addition to *note PendingDeprecationWarning: ac8.

Cambiato nella versione 3.7: *note DeprecationWarning: 1a3. is once
again shown by default when triggered directly by code in ‘__main__’.

Cambiato nella versione 3.7: *note BytesWarning: e1e. no longer appears
in the default filter list and is instead configured via *note
sys.warnoptions: 3f5. when *note -b: 7fa. is specified twice.


File: python.info,  Node: Overriding the default filter,  Prev: Default Warning Filter,  Up: The Warnings Filter

5.29.6.6 Overriding the default filter
......................................

Developers of applications written in Python may wish to hide 'all'
Python level warnings from their users by default, and only display them
when running tests or otherwise working on the application.  The *note
sys.warnoptions: 3f5. attribute used to pass filter configurations to
the interpreter can be used as a marker to indicate whether or not
warnings should be disabled:

     import sys

     if not sys.warnoptions:
         import warnings
         warnings.simplefilter("ignore")

Developers of test runners for Python code are advised to instead ensure
that 'all' warnings are displayed by default for the code under test,
using code like:

     import sys

     if not sys.warnoptions:
         import os, warnings
         warnings.simplefilter("default") # Change the filter in this process
         os.environ["PYTHONWARNINGS"] = "default" # Also affect subprocesses

Finally, developers of interactive shells that run user code in a
namespace other than ‘__main__’ are advised to ensure that *note
DeprecationWarning: 1a3. messages are made visible by default, using
code like the following (where ‘user_ns’ is the module used to execute
code entered interactively):

     import warnings
     warnings.filterwarnings("default", category=DeprecationWarning,
                                        module=user_ns.get("__name__"))


File: python.info,  Node: Temporarily Suppressing Warnings,  Next: Testing Warnings,  Prev: The Warnings Filter,  Up: warnings — Warning control

5.29.6.7 Temporarily Suppressing Warnings
.........................................

If you are using code that you know will raise a warning, such as a
deprecated function, but do not want to see the warning (even when
warnings have been explicitly configured via the command line), then it
is possible to suppress the warning using the *note catch_warnings: 179.
context manager:

     import warnings

     def fxn():
         warnings.warn("deprecated", DeprecationWarning)

     with warnings.catch_warnings():
         warnings.simplefilter("ignore")
         fxn()

While within the context manager all warnings will simply be ignored.
This allows you to use known-deprecated code without having to see the
warning while not suppressing the warning for other code that might not
be aware of its use of deprecated code.

          Nota: See *note Concurrent safety of Context Managers: 497e.
          for details on the concurrency-safety of the *note
          catch_warnings: 179. context manager when used in programs
          using multiple threads or async functions.


File: python.info,  Node: Testing Warnings,  Next: Updating Code For New Versions of Dependencies,  Prev: Temporarily Suppressing Warnings,  Up: warnings — Warning control

5.29.6.8 Testing Warnings
.........................

To test warnings raised by code, use the *note catch_warnings: 179.
context manager.  With it you can temporarily mutate the warnings filter
to facilitate your testing.  For instance, do the following to capture
all raised warnings to check:

     import warnings

     def fxn():
         warnings.warn("deprecated", DeprecationWarning)

     with warnings.catch_warnings(record=True) as w:
         # Cause all warnings to always be triggered.
         warnings.simplefilter("always")
         # Trigger a warning.
         fxn()
         # Verify some things
         assert len(w) == 1
         assert issubclass(w[-1].category, DeprecationWarning)
         assert "deprecated" in str(w[-1].message)

One can also cause all warnings to be exceptions by using ‘error’
instead of ‘always’.  One thing to be aware of is that if a warning has
already been raised because of a ‘once’/‘default’ rule, then no matter
what filters are set the warning will not be seen again unless the
warnings registry related to the warning has been cleared.

Once the context manager exits, the warnings filter is restored to its
state when the context was entered.  This prevents tests from changing
the warnings filter in unexpected ways between tests and leading to
indeterminate test results.

          Nota: See *note Concurrent safety of Context Managers: 497e.
          for details on the concurrency-safety of the *note
          catch_warnings: 179. context manager when used in programs
          using multiple threads or async functions.

When testing multiple operations that raise the same kind of warning, it
is important to test them in a manner that confirms each operation is
raising a new warning (e.g.  set warnings to be raised as exceptions and
check the operations raise exceptions, check that the length of the
warning list continues to increase after each operation, or else delete
the previous entries from the warnings list before each new operation).


File: python.info,  Node: Updating Code For New Versions of Dependencies,  Next: Available Functions,  Prev: Testing Warnings,  Up: warnings — Warning control

5.29.6.9 Updating Code For New Versions of Dependencies
.......................................................

Warning categories that are primarily of interest to Python developers
(rather than end users of applications written in Python) are ignored by
default.

Notably, this «ignored by default» list includes *note
DeprecationWarning: 1a3. (for every module except ‘__main__’), which
means developers should make sure to test their code with typically
ignored warnings made visible in order to receive timely notifications
of future breaking API changes (whether in the standard library or third
party packages).

In the ideal case, the code will have a suitable test suite, and the
test runner will take care of implicitly enabling all warnings when
running tests (the test runner provided by the *note unittest: 10c.
module does this).

In less ideal cases, applications can be checked for use of deprecated
interfaces by passing *note -Wd: ac7. to the Python interpreter (this is
shorthand for ‘-W default’) or setting ‘PYTHONWARNINGS=default’ in the
environment.  This enables default handling for all warnings, including
those that are ignored by default.  To change what action is taken for
encountered warnings you can change what argument is passed to *note -W:
ac7. (e.g.  ‘-W error’).  See the *note -W: ac7. flag for more details
on what is possible.


File: python.info,  Node: Available Functions,  Next: Available Context Managers,  Prev: Updating Code For New Versions of Dependencies,  Up: warnings — Warning control

5.29.6.10 Available Functions
.............................

 -- Funzione: warnings.warn (message, category=None, stacklevel=1,
          source=None, *, skip_file_prefixes=())

     Issue a warning, or maybe ignore it or raise an exception.  The
     'category' argument, if given, must be a *note warning category
     class: 26f4.; it defaults to *note UserWarning: 26f6.
     Alternatively, 'message' can be a *note Warning: 26f5. instance, in
     which case 'category' will be ignored and ‘message.__class__’ will
     be used.  In this case, the message text will be ‘str(message)’.
     This function raises an exception if the particular warning issued
     is changed into an error by the *note warnings filter: 1b1.  The
     'stacklevel' argument can be used by wrapper functions written in
     Python, like this:

          def deprecated_api(message):
              warnings.warn(message, DeprecationWarning, stacklevel=2)

     This makes the warning refer to ‘deprecated_api’’s caller, rather
     than to the source of ‘deprecated_api’ itself (since the latter
     would defeat the purpose of the warning message).

     The 'skip_file_prefixes' keyword argument can be used to indicate
     which stack frames are ignored when counting stack levels.  This
     can be useful when you want the warning to always appear at call
     sites outside of a package when a constant 'stacklevel' does not
     fit all call paths or is otherwise challenging to maintain.  If
     supplied, it must be a tuple of strings.  When prefixes are
     supplied, stacklevel is implicitly overridden to be ‘max(2,
     stacklevel)’.  To cause a warning to be attributed to the caller
     from outside of the current package you might write:

          # example/lower.py
          _warn_skips = (os.path.dirname(__file__),)

          def one_way(r_luxury_yacht=None, t_wobbler_mangrove=None):
              if r_luxury_yacht:
                  warnings.warn("Please migrate to t_wobbler_mangrove=.",
                                skip_file_prefixes=_warn_skips)

          # example/higher.py
          from . import lower

          def another_way(**kw):
              lower.one_way(**kw)

     This makes the warning refer to both the ‘example.lower.one_way()’
     and ‘example.higher.another_way()’ call sites only from calling
     code living outside of ‘example’ package.

     'source', if supplied, is the destroyed object which emitted a
     *note ResourceWarning: 54d.

     Cambiato nella versione 3.6: Added 'source' parameter.

     Cambiato nella versione 3.12: Added 'skip_file_prefixes'.

 -- Funzione: warnings.warn_explicit (message, category, filename,
          lineno, module=None, registry=None, module_globals=None,
          source=None)

     This is a low-level interface to the functionality of *note warn():
     1720, passing in explicitly the message, category, filename and
     line number, and optionally other arguments.  'message' must be a
     string and 'category' a subclass of *note Warning: 26f5. or
     'message' may be a *note Warning: 26f5. instance, in which case
     'category' will be ignored.

     'module', if supplied, should be the module name.  If no module is
     passed, the filename with ‘.py’ stripped is used.

     'registry', if supplied, should be the ‘__warningregistry__’
     dictionary of the module.  If no registry is passed, each warning
     is treated as the first occurrence, that is, filter actions
     ‘"default"’, ‘"module"’ and ‘"once"’ are handled as ‘"always"’.

     'module_globals', if supplied, should be the global namespace in
     use by the code for which the warning is issued.  (This argument is
     used to support displaying source for modules found in zipfiles or
     other non-filesystem import sources).

     'source', if supplied, is the destroyed object which emitted a
     *note ResourceWarning: 54d.

     Cambiato nella versione 3.6: Add the 'source' parameter.

 -- Funzione: warnings.showwarning (message, category, filename, lineno,
          file=None, line=None)

     Write a warning to a file.  The default implementation calls
     ‘formatwarning(message, category, filename, lineno, line)’ and
     writes the resulting string to 'file', which defaults to *note
     sys.stderr: b35.  You may replace this function with any callable
     by assigning to ‘warnings.showwarning’.  'line' is a line of source
     code to be included in the warning message; if 'line' is not
     supplied, *note showwarning(): 4972. will try to read the line
     specified by 'filename' and 'lineno'.

 -- Funzione: warnings.formatwarning (message, category, filename,
          lineno, line=None)

     Format a warning the standard way.  This returns a string which may
     contain embedded newlines and ends in a newline.  'line' is a line
     of source code to be included in the warning message; if 'line' is
     not supplied, *note formatwarning(): 1de0. will try to read the
     line specified by 'filename' and 'lineno'.

 -- Funzione: warnings.filterwarnings (action, message='',
          category=Warning, module='', lineno=0, append=False)

     Insert an entry into the list of *note warnings filter
     specifications: 1b1.  The entry is inserted at the front by
     default; if 'append' is true, it is inserted at the end.  This
     checks the types of the arguments, compiles the 'message' and
     'module' regular expressions, and inserts them as a tuple in the
     list of warnings filters.  Entries closer to the front of the list
     override entries later in the list, if both match a particular
     warning.  Omitted arguments default to a value that matches
     everything.

 -- Funzione: warnings.simplefilter (action, category=Warning, lineno=0,
          append=False)

     Insert a simple entry into the list of *note warnings filter
     specifications: 1b1.  The meaning of the function parameters is as
     for *note filterwarnings(): 16b0, but regular expressions are not
     needed as the filter inserted always matches any message in any
     module as long as the category and line number match.

 -- Funzione: warnings.resetwarnings ()

     Reset the warnings filter.  This discards the effect of all
     previous calls to *note filterwarnings(): 16b0, including that of
     the *note -W: ac7. command line options and calls to *note
     simplefilter(): 8d1.

 -- Funzione: @warnings.deprecated (msg, *, category=DeprecationWarning,
          stacklevel=1)

     Decorator to indicate that a class, function or overload is
     deprecated.

     When this decorator is applied to an object, deprecation warnings
     may be emitted at runtime when the object is used.  *note static
     type checkers: 574. will also generate a diagnostic on usage of the
     deprecated object.

     Usage:

          from warnings import deprecated
          from typing import overload

          @deprecated("Use B instead")
          class A:
              pass

          @deprecated("Use g instead")
          def f():
              pass

          @overload
          @deprecated("int support is deprecated")
          def g(x: int) -> int: ...
          @overload
          def g(x: str) -> int: ...

     The warning specified by 'category' will be emitted at runtime on
     use of deprecated objects.  For functions, that happens on calls;
     for classes, on instantiation and on creation of subclasses.  If
     the 'category' is ‘None’, no warning is emitted at runtime.  The
     'stacklevel' determines where the warning is emitted.  If it is ‘1’
     (the default), the warning is emitted at the direct caller of the
     deprecated object; if it is higher, it is emitted further up the
     stack.  Static type checker behavior is not affected by the
     'category' and 'stacklevel' arguments.

     The deprecation message passed to the decorator is saved in the
     ‘__deprecated__’ attribute on the decorated object.  If applied to
     an overload, the decorator must be after the *note
     @~typing.overload: 44fc. decorator for the attribute to exist on
     the overload as returned by *note typing.get_overloads(): 8be.

     Added in version 3.13: See PEP 702(1).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0702/


File: python.info,  Node: Available Context Managers,  Next: Concurrent safety of Context Managers,  Prev: Available Functions,  Up: warnings — Warning control

5.29.6.11 Available Context Managers
....................................

 -- Classe: warnings.catch_warnings (*, record=False, module=None,
          action=None, category=Warning, lineno=0, append=False)

     A context manager that copies and, upon exit, restores the warnings
     filter and the *note showwarning(): 4972. function.  If the
     'record' argument is *note False: d2d. (the default) the context
     manager returns *note None: 886. on entry.  If 'record' is *note
     True: e09, a list is returned that is progressively populated with
     objects as seen by a custom *note showwarning(): 4972. function
     (which also suppresses output to ‘sys.stdout’).  Each object in the
     list has attributes with the same names as the arguments to *note
     showwarning(): 4972.

     The 'module' argument takes a module that will be used instead of
     the module returned when you import *note warnings: 118. whose
     filter will be protected.  This argument exists primarily for
     testing the *note warnings: 118. module itself.

     If the 'action' argument is not ‘None’, the remaining arguments are
     passed to *note simplefilter(): 8d1. as if it were called
     immediately on entering the context.

     See *note The Warnings Filter: 1b1. for the meaning of the
     'category' and 'lineno' parameters.

          Nota: See *note Concurrent safety of Context Managers: 497e.
          for details on the concurrency-safety of the *note
          catch_warnings: 179. context manager when used in programs
          using multiple threads or async functions.

     Cambiato nella versione 3.11: Added the 'action', 'category',
     'lineno', and 'append' parameters.


File: python.info,  Node: Concurrent safety of Context Managers,  Prev: Available Context Managers,  Up: warnings — Warning control

5.29.6.12 Concurrent safety of Context Managers
...............................................

The behavior of *note catch_warnings: 179. context manager depends on
the *note sys.flags.context_aware_warnings: 18a. flag.  If the flag is
true, the context manager behaves in a concurrent-safe fashion and
otherwise not.  Concurrent-safe means that it is both thread-safe and
safe to use within *note asyncio coroutines: 379e. and tasks.  Being
thread-safe means that behavior is predictable in a multi-threaded
program.  The flag defaults to true for free-threaded builds and false
otherwise.

If the *note context_aware_warnings: 18a. flag is false, then *note
catch_warnings: 179. will modify the global attributes of the *note
warnings: 118. module.  This is not safe if used within a concurrent
program (using multiple threads or using asyncio coroutines).  For
example, if two or more threads use the *note catch_warnings: 179. class
at the same time, the behavior is undefined.

If the flag is true, *note catch_warnings: 179. will not modify global
attributes and will instead use a *note ContextVar: 185d. to store the
newly established warning filtering state.  A context variable provides
thread-local storage and it makes the use of *note catch_warnings: 179.
thread-safe.

The 'record' parameter of the context handler also behaves differently
depending on the value of the flag.  When 'record' is true and the flag
is false, the context manager works by replacing and then later
restoring the module’s *note showwarning(): 4972. function.  That is not
concurrent-safe.

When 'record' is true and the flag is true, the *note showwarning():
4972. function is not replaced.  Instead, the recording status is
indicated by an internal property in the context variable.  In this
case, the *note showwarning(): 4972. function will not be restored when
exiting the context handler.

The *note context_aware_warnings: 18a. flag can be set the *note -X
context_aware_warnings: 16f. command-line option or by the *note
PYTHON_CONTEXT_AWARE_WARNINGS: 1843. environment variable.

          Nota: It is likely that most programs that desire thread-safe
          behaviour of the warnings module will also want to set the
          *note thread_inherit_context: 175. flag to true.  That flag
          causes threads created by *note threading.Thread: 176. to
          start with a copy of the context variables from the thread
          starting it.  When true, the context established by *note
          catch_warnings: 179. in one thread will also apply to new
          threads started by it.  If false, new threads will start with
          an empty warnings context variable, meaning that any filtering
          that was established by a *note catch_warnings: 179. context
          manager will no longer be active.

Cambiato nella versione 3.14: Added the *note
sys.flags.context_aware_warnings: 18a. flag and the use of a context
variable for *note catch_warnings: 179. if the flag is true.  Previous
versions of Python acted as if the flag was always set to false.


File: python.info,  Node: dataclasses — Data Classes,  Next: contextlib — Utilities for with-statement contexts,  Prev: warnings — Warning control,  Up: Python Runtime Services

5.29.7 ‘dataclasses’ — Data Classes
-----------------------------------

'Source code:' Lib/dataclasses.py(1)

__________________________________________________________________

This module provides a decorator and functions for automatically adding
generated *note special methods: 1c48. such as *note __init__(): 8c0.
and *note __repr__(): 830. to user-defined classes.  It was originally
described in PEP 557(2).

The member variables to use in these generated methods are defined using
PEP 526(3) type annotations.  For example, this code:

     from dataclasses import dataclass

     @dataclass
     class InventoryItem:
         """Class for keeping track of an item in inventory."""
         name: str
         unit_price: float
         quantity_on_hand: int = 0

         def total_cost(self) -> float:
             return self.unit_price * self.quantity_on_hand

will add, among other things, a ‘__init__()’ that looks like:

     def __init__(self, name: str, unit_price: float, quantity_on_hand: int = 0):
         self.name = name
         self.unit_price = unit_price
         self.quantity_on_hand = quantity_on_hand

Note that this method is automatically added to the class: it is not
directly specified in the ‘InventoryItem’ definition shown above.

Added in version 3.7.

* Menu:

* Module contents: Module contents<4>.
* Post-init processing::
* Class variables::
* Init-only variables::
* Frozen instances::
* Inheritance::
* Re-ordering of keyword-only parameters in __init__(): Re-ordering of keyword-only parameters in __init__.
* Default factory functions::
* Mutable default values::
* Descriptor-typed fields::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/dataclasses.py

   (2) https://peps.python.org/pep-0557/

   (3) https://peps.python.org/pep-0526/


File: python.info,  Node: Module contents<4>,  Next: Post-init processing,  Up: dataclasses — Data Classes

5.29.7.1 Module contents
........................

 -- Funzione: @dataclasses.dataclass (*, init=True, repr=True, eq=True,
          order=False, unsafe_hash=False, frozen=False, match_args=True,
          kw_only=False, slots=False, weakref_slot=False)

     This function is a *note decorator: 93b. that is used to add
     generated *note special methods: 1c48. to classes, as described
     below.

     The ‘@dataclass’ decorator examines the class to find ‘field’s.  A
     ‘field’ is defined as a class variable that has a *note type
     annotation: f53.  With two exceptions described below, nothing in
     ‘@dataclass’ examines the type specified in the variable
     annotation.

     The order of the fields in all of the generated methods is the
     order in which they appear in the class definition.

     The ‘@dataclass’ decorator will add various «dunder» methods to the
     class, described below.  If any of the added methods already exist
     in the class, the behavior depends on the parameter, as documented
     below.  The decorator returns the same class that it is called on;
     no new class is created.

     If ‘@dataclass’ is used just as a simple decorator with no
     parameters, it acts as if it has the default values documented in
     this signature.  That is, these three uses of ‘@dataclass’ are
     equivalent:

          @dataclass
          class C:
              ...

          @dataclass()
          class C:
              ...

          @dataclass(init=True, repr=True, eq=True, order=False, unsafe_hash=False, frozen=False,
                     match_args=True, kw_only=False, slots=False, weakref_slot=False)
          class C:
              ...

     The parameters to ‘@dataclass’ are:

        - 'init': If true (the default), a *note __init__(): 8c0. method
          will be generated.

          If the class already defines ‘__init__()’, this parameter is
          ignored.

        - 'repr': If true (the default), a *note __repr__(): 830. method
          will be generated.  The generated repr string will have the
          class name and the name and repr of each field, in the order
          they are defined in the class.  Fields that are marked as
          being excluded from the repr are not included.  For example:
          ‘InventoryItem(name='widget', unit_price=3.0,
          quantity_on_hand=10)’.

          If the class already defines ‘__repr__()’, this parameter is
          ignored.

        - 'eq': If true (the default), an *note __eq__(): cf4. method
          will be generated.  This method compares the class as if it
          were a tuple of its fields, in order.  Both instances in the
          comparison must be of the identical type.

          If the class already defines ‘__eq__()’, this parameter is
          ignored.

        - 'order': If true (the default is ‘False’), *note __lt__():
          14a8, *note __le__(): 1512, *note __gt__(): 1513, and *note
          __ge__(): 1514. methods will be generated.  These compare the
          class as if it were a tuple of its fields, in order.  Both
          instances in the comparison must be of the identical type.  If
          'order' is true and 'eq' is false, a *note ValueError: 2ec. is
          raised.

          If the class already defines any of ‘__lt__()’, ‘__le__()’,
          ‘__gt__()’, or ‘__ge__()’, then *note TypeError: 198. is
          raised.

        - 'unsafe_hash': If true, force ‘dataclasses’ to create a *note
          __hash__(): cf5. method, even though it may not be safe to do
          so.  Otherwise, generate a *note __hash__(): cf5. method
          according to how 'eq' and 'frozen' are set.  The default value
          is ‘False’.

          ‘__hash__()’ is used by built-in *note hash(): 802, and when
          objects are added to hashed collections such as dictionaries
          and sets.  Having a ‘__hash__()’ implies that instances of the
          class are immutable.  Mutability is a complicated property
          that depends on the programmer’s intent, the existence and
          behavior of ‘__eq__()’, and the values of the 'eq' and
          'frozen' flags in the ‘@dataclass’ decorator.

          By default, ‘@dataclass’ will not implicitly add a *note
          __hash__(): cf5. method unless it is safe to do so.  Neither
          will it add or change an existing explicitly defined
          ‘__hash__()’ method.  Setting the class attribute ‘__hash__ =
          None’ has a specific meaning to Python, as described in the
          ‘__hash__()’ documentation.

          If ‘__hash__()’ is not explicitly defined, or if it is set to
          ‘None’, then ‘@dataclass’ 'may' add an implicit ‘__hash__()’
          method.  Although not recommended, you can force ‘@dataclass’
          to create a ‘__hash__()’ method with ‘unsafe_hash=True’.  This
          might be the case if your class is logically immutable but can
          still be mutated.  This is a specialized use case and should
          be considered carefully.

          Here are the rules governing implicit creation of a
          ‘__hash__()’ method.  Note that you cannot both have an
          explicit ‘__hash__()’ method in your dataclass and set
          ‘unsafe_hash=True’; this will result in a *note TypeError:
          198.

          If 'eq' and 'frozen' are both true, by default ‘@dataclass’
          will generate a ‘__hash__()’ method for you.  If 'eq' is true
          and 'frozen' is false, ‘__hash__()’ will be set to ‘None’,
          marking it unhashable (which it is, since it is mutable).  If
          'eq' is false, ‘__hash__()’ will be left untouched meaning the
          ‘__hash__()’ method of the superclass will be used (if the
          superclass is *note object: c80, this means it will fall back
          to id-based hashing).

        - 'frozen': If true (the default is ‘False’), assigning to
          fields will generate an exception.  This emulates read-only
          frozen instances.  See the *note discussion: 498a. below.

          If *note __setattr__(): 2362. or *note __delattr__(): 2363. is
          defined in the class and 'frozen' is true, then *note
          TypeError: 198. is raised.

        - 'match_args': If true (the default is ‘True’), the *note
          __match_args__: 1c5d. tuple will be created from the list of
          non keyword-only parameters to the generated *note __init__():
          8c0. method (even if ‘__init__()’ is not generated, see
          above).  If false, or if ‘__match_args__’ is already defined
          in the class, then ‘__match_args__’ will not be generated.

          Added in version 3.10.

        - 'kw_only': If true (the default value is ‘False’), then all
          fields will be marked as keyword-only.  If a field is marked
          as keyword-only, then the only effect is that the *note
          __init__(): 8c0. parameter generated from a keyword-only field
          must be specified with a keyword when ‘__init__()’ is called.
          See the *note parameter: 2332. glossary entry for details.
          Also see the *note KW_ONLY: 498b. section.

          Keyword-only fields are not included in ‘__match_args__’.

          Added in version 3.10.

        - 'slots': If true (the default is ‘False’), *note __slots__:
          16f2. attribute will be generated and new class will be
          returned instead of the original one.  If ‘__slots__’ is
          already defined in the class, then *note TypeError: 198. is
          raised.

               Avvertimento: Passing parameters to a base class *note
               __init_subclass__(): 844. when using ‘slots=True’ will
               result in a *note TypeError: 198.  Either use
               ‘__init_subclass__’ with no parameters or use default
               values as a workaround.  See gh-91126(1) for full
               details.

          Added in version 3.10.

          Cambiato nella versione 3.11: If a field name is already
          included in the ‘__slots__’ of a base class, it will not be
          included in the generated ‘__slots__’ to prevent *note
          overriding them: 23a0.  Therefore, do not use ‘__slots__’ to
          retrieve the field names of a dataclass.  Use *note fields():
          191d. instead.  To be able to determine inherited slots, base
          class ‘__slots__’ may be any iterable, but 'not' an iterator.

        - 'weakref_slot': If true (the default is ‘False’), add a slot
          named «__weakref__», which is required to make an instance
          *note weakref-able: 11f2.  It is an error to specify
          ‘weakref_slot=True’ without also specifying ‘slots=True’.

          Added in version 3.11.

     ‘field’s may optionally specify a default value, using normal
     Python syntax:

          @dataclass
          class C:
              a: int       # 'a' has no default value
              b: int = 0   # assign a default value for 'b'

     In this example, both ‘a’ and ‘b’ will be included in the added
     *note __init__(): 8c0. method, which will be defined as:

          def __init__(self, a: int, b: int = 0):

     *note TypeError: 198. will be raised if a field without a default
     value follows a field with a default value.  This is true whether
     this occurs in a single class, or as a result of class inheritance.

 -- Funzione: dataclasses.field (*, default=MISSING,
          default_factory=MISSING, init=True, repr=True, hash=None,
          compare=True, metadata=None, kw_only=MISSING, doc=None)

     For common and simple use cases, no other functionality is
     required.  There are, however, some dataclass features that require
     additional per-field information.  To satisfy this need for
     additional information, you can replace the default field value
     with a call to the provided ‘field()’ function.  For example:

          @dataclass
          class C:
              mylist: list[int] = field(default_factory=list)

          c = C()
          c.mylist += [1, 2, 3]

     As shown above, the *note MISSING: 498c. value is a sentinel object
     used to detect if some parameters are provided by the user.  This
     sentinel is used because ‘None’ is a valid value for some
     parameters with a distinct meaning.  No code should directly use
     the *note MISSING: 498c. value.

     The parameters to ‘field()’ are:

        - 'default': If provided, this will be the default value for
          this field.  This is needed because the ‘field()’ call itself
          replaces the normal position of the default value.

        - 'default_factory': If provided, it must be a zero-argument
          callable that will be called when a default value is needed
          for this field.  Among other purposes, this can be used to
          specify fields with mutable default values, as discussed
          below.  It is an error to specify both 'default' and
          'default_factory'.

        - 'init': If true (the default), this field is included as a
          parameter to the generated *note __init__(): 8c0. method.

        - 'repr': If true (the default), this field is included in the
          string returned by the generated *note __repr__(): 830.
          method.

        - 'hash': This can be a bool or ‘None’.  If true, this field is
          included in the generated *note __hash__(): cf5. method.  If
          false, this field is excluded from the generated *note
          __hash__(): cf5.  If ‘None’ (the default), use the value of
          'compare': this would normally be the expected behavior, since
          a field should be included in the hash if it’s used for
          comparisons.  Setting this value to anything other than ‘None’
          is discouraged.

          One possible reason to set ‘hash=False’ but ‘compare=True’
          would be if a field is expensive to compute a hash value for,
          that field is needed for equality testing, and there are other
          fields that contribute to the type’s hash value.  Even if a
          field is excluded from the hash, it will still be used for
          comparisons.

        - 'compare': If true (the default), this field is included in
          the generated equality and comparison methods (*note __eq__():
          cf4, *note __gt__(): 1513, et al.).

        - 'metadata': This can be a mapping or ‘None’.  ‘None’ is
          treated as an empty dict.  This value is wrapped in *note
          MappingProxyType(): 699. to make it read-only, and exposed on
          the *note Field: 1943. object.  It is not used at all by Data
          Classes, and is provided as a third-party extension mechanism.
          Multiple third-parties can each have their own key, to use as
          a namespace in the metadata.

        - 'kw_only': If true, this field will be marked as keyword-only.
          This is used when the generated *note __init__(): 8c0.
          method’s parameters are computed.

          Keyword-only fields are also not included in ‘__match_args__’.

          Added in version 3.10.

        - 'doc': optional docstring for this field.

          Added in version 3.14.

     If the default value of a field is specified by a call to
     ‘field()’, then the class attribute for this field will be replaced
     by the specified 'default' value.  If 'default' is not provided,
     then the class attribute will be deleted.  The intent is that after
     the *note @dataclass: 4e2. decorator runs, the class attributes
     will all contain the default values for the fields, just as if the
     default value itself were specified.  For example, after:

          @dataclass
          class C:
              x: int
              y: int = field(repr=False)
              z: int = field(repr=False, default=10)
              t: int = 20

     The class attribute ‘C.z’ will be ‘10’, the class attribute ‘C.t’
     will be ‘20’, and the class attributes ‘C.x’ and ‘C.y’ will not be
     set.

 -- Classe: dataclasses.Field

     ‘Field’ objects describe each defined field.  These objects are
     created internally, and are returned by the *note fields(): 191d.
     module-level method (see below).  Users should never instantiate a
     ‘Field’ object directly.  Its documented attributes are:

        - ‘name’: The name of the field.

        - ‘type’: The type of the field.

        - ‘default’, ‘default_factory’, ‘init’, ‘repr’, ‘hash’,
          ‘compare’, ‘metadata’, and ‘kw_only’ have the identical
          meaning and values as they do in the *note field(): 1942.
          function.

     Other attributes may exist, but they are private and must not be
     inspected or relied on.

 -- Classe: dataclasses.InitVar

     ‘InitVar[T]’ type annotations describe variables that are *note
     init-only: 498d.  Fields annotated with ‘InitVar’ are considered
     pseudo-fields, and thus are neither returned by the *note fields():
     191d. function nor used in any way except adding them as parameters
     to *note __init__(): 8c0. and an optional *note __post_init__():
     498e.

 -- Funzione: dataclasses.fields (class_or_instance)

     Returns a tuple of *note Field: 1943. objects that define the
     fields for this dataclass.  Accepts either a dataclass, or an
     instance of a dataclass.  Raises *note TypeError: 198. if not
     passed a dataclass or instance of one.  Does not return
     pseudo-fields which are ‘ClassVar’ or ‘InitVar’.

 -- Funzione: dataclasses.asdict (obj, *, dict_factory=dict)

     Converts the dataclass 'obj' to a dict (by using the factory
     function 'dict_factory').  Each dataclass is converted to a dict of
     its fields, as ‘name: value’ pairs.  dataclasses, dicts, lists, and
     tuples are recursed into.  Other objects are copied with *note
     copy.deepcopy(): d67.

     Example of using ‘asdict()’ on nested dataclasses:

          @dataclass
          class Point:
               x: int
               y: int

          @dataclass
          class C:
               mylist: list[Point]

          p = Point(10, 20)
          assert asdict(p) == {'x': 10, 'y': 20}

          c = C([Point(0, 0), Point(10, 4)])
          assert asdict(c) == {'mylist': [{'x': 0, 'y': 0}, {'x': 10, 'y': 4}]}

     To create a shallow copy, the following workaround may be used:

          {field.name: getattr(obj, field.name) for field in fields(obj)}

     ‘asdict()’ raises *note TypeError: 198. if 'obj' is not a dataclass
     instance.

 -- Funzione: dataclasses.astuple (obj, *, tuple_factory=tuple)

     Converts the dataclass 'obj' to a tuple (by using the factory
     function 'tuple_factory').  Each dataclass is converted to a tuple
     of its field values.  dataclasses, dicts, lists, and tuples are
     recursed into.  Other objects are copied with *note
     copy.deepcopy(): d67.

     Continuing from the previous example:

          assert astuple(p) == (10, 20)
          assert astuple(c) == ([(0, 0), (10, 4)],)

     To create a shallow copy, the following workaround may be used:

          tuple(getattr(obj, field.name) for field in dataclasses.fields(obj))

     ‘astuple()’ raises *note TypeError: 198. if 'obj' is not a
     dataclass instance.

 -- Funzione: dataclasses.make_dataclass (cls_name, fields, *, bases=(),
          namespace=None, init=True, repr=True, eq=True, order=False,
          unsafe_hash=False, frozen=False, match_args=True,
          kw_only=False, slots=False, weakref_slot=False, module=None,
          decorator=dataclass)

     Creates a new dataclass with name 'cls_name', fields as defined in
     'fields', base classes as given in 'bases', and initialized with a
     namespace as given in 'namespace'.  'fields' is an iterable whose
     elements are each either ‘name’, ‘(name, type)’, or ‘(name, type,
     Field)’.  If just ‘name’ is supplied, *note typing.Any: 8bc. is
     used for ‘type’.  The values of 'init', 'repr', 'eq', 'order',
     'unsafe_hash', 'frozen', 'match_args', 'kw_only', 'slots', and
     'weakref_slot' have the same meaning as they do in *note
     @dataclass: 4e2.

     If 'module' is defined, the ‘__module__’ attribute of the dataclass
     is set to that value.  By default, it is set to the module name of
     the caller.

     The 'decorator' parameter is a callable that will be used to create
     the dataclass.  It should take the class object as a first argument
     and the same keyword arguments as *note @dataclass: 4e2.  By
     default, the *note @dataclass: 4e2. function is used.

     This function is not strictly required, because any Python
     mechanism for creating a new class with *note __annotations__: 458.
     can then apply the *note @dataclass: 4e2. function to convert that
     class to a dataclass.  This function is provided as a convenience.
     For example:

          C = make_dataclass('C',
                             [('x', int),
                               'y',
                              ('z', int, field(default=5))],
                             namespace={'add_one': lambda self: self.x + 1})

     Is equivalent to:

          @dataclass
          class C:
              x: int
              y: 'typing.Any'
              z: int = 5

              def add_one(self):
                  return self.x + 1

     Added in version 3.14: Added the 'decorator' parameter.

 -- Funzione: dataclasses.replace (obj, /, **changes)

     Creates a new object of the same type as 'obj', replacing fields
     with values from 'changes'.  If 'obj' is not a Data Class, raises
     *note TypeError: 198.  If keys in 'changes' are not field names of
     the given dataclass, raises *note TypeError: 198.

     The newly returned object is created by calling the *note
     __init__(): 8c0. method of the dataclass.  This ensures that *note
     __post_init__(): 498e, if present, is also called.

     Init-only variables without default values, if any exist, must be
     specified on the call to ‘replace()’ so that they can be passed to
     ‘__init__()’ and *note __post_init__(): 498e.

     It is an error for 'changes' to contain any fields that are defined
     as having ‘init=False’.  A *note ValueError: 2ec. will be raised in
     this case.

     Be forewarned about how ‘init=False’ fields work during a call to
     ‘replace()’.  They are not copied from the source object, but
     rather are initialized in *note __post_init__(): 498e, if they’re
     initialized at all.  It is expected that ‘init=False’ fields will
     be rarely and judiciously used.  If they are used, it might be wise
     to have alternate class constructors, or perhaps a custom
     ‘replace()’ (or similarly named) method which handles instance
     copying.

     Dataclass instances are also supported by generic function *note
     copy.replace(): 1c0.

 -- Funzione: dataclasses.is_dataclass (obj)

     Return ‘True’ if its parameter is a dataclass (including subclasses
     of a dataclass) or an instance of one, otherwise return ‘False’.

     If you need to know if a class is an instance of a dataclass (and
     not a dataclass itself), then add a further check for ‘not
     isinstance(obj, type)’:

          def is_dataclass_instance(obj):
              return is_dataclass(obj) and not isinstance(obj, type)

 -- Dati: dataclasses.MISSING

     A sentinel value signifying a missing default or default_factory.

 -- Dati: dataclasses.KW_ONLY

     A sentinel value used as a type annotation.  Any fields after a
     pseudo-field with the type of ‘KW_ONLY’ are marked as keyword-only
     fields.  Note that a pseudo-field of type ‘KW_ONLY’ is otherwise
     completely ignored.  This includes the name of such a field.  By
     convention, a name of ‘_’ is used for a ‘KW_ONLY’ field.
     Keyword-only fields signify *note __init__(): 8c0. parameters that
     must be specified as keywords when the class is instantiated.

     In this example, the fields ‘y’ and ‘z’ will be marked as
     keyword-only fields:

          @dataclass
          class Point:
              x: float
              _: KW_ONLY
              y: float
              z: float

          p = Point(0, y=1.5, z=2.0)

     In a single dataclass, it is an error to specify more than one
     field whose type is ‘KW_ONLY’.

     Added in version 3.10.

 -- Eccezione: dataclasses.FrozenInstanceError

     Raised when an implicitly defined *note __setattr__(): 2362. or
     *note __delattr__(): 2363. is called on a dataclass which was
     defined with ‘frozen=True’.  It is a subclass of *note
     AttributeError: 5f0.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/91126


File: python.info,  Node: Post-init processing,  Next: Class variables,  Prev: Module contents<4>,  Up: dataclasses — Data Classes

5.29.7.2 Post-init processing
.............................

 -- Funzione: dataclasses.__post_init__ ()

     When defined on the class, it will be called by the generated *note
     __init__(): 8c0, normally as ‘self.__post_init__()’.  However, if
     any ‘InitVar’ fields are defined, they will also be passed to
     ‘__post_init__()’ in the order they were defined in the class.  If
     no ‘__init__()’ method is generated, then ‘__post_init__()’ will
     not automatically be called.

     Among other uses, this allows for initializing field values that
     depend on one or more other fields.  For example:

          @dataclass
          class C:
              a: float
              b: float
              c: float = field(init=False)

              def __post_init__(self):
                  self.c = self.a + self.b

The *note __init__(): 8c0. method generated by *note @dataclass: 4e2.
does not call base class ‘__init__()’ methods.  If the base class has an
‘__init__()’ method that has to be called, it is common to call this
method in a *note __post_init__(): 498e. method:

     class Rectangle:
         def __init__(self, height, width):
             self.height = height
             self.width = width

     @dataclass
     class Square(Rectangle):
         side: float

         def __post_init__(self):
             super().__init__(self.side, self.side)

Note, however, that in general the dataclass-generated ‘__init__()’
methods don’t need to be called, since the derived dataclass will take
care of initializing all fields of any base class that is a dataclass
itself.

See the section below on init-only variables for ways to pass parameters
to ‘__post_init__()’.  Also see the warning about how *note replace():
1a52. handles ‘init=False’ fields.


File: python.info,  Node: Class variables,  Next: Init-only variables,  Prev: Post-init processing,  Up: dataclasses — Data Classes

5.29.7.3 Class variables
........................

One of the few places where *note @dataclass: 4e2. actually inspects the
type of a field is to determine if a field is a class variable as
defined in PEP 526(1).  It does this by checking if the type of the
field is *note typing.ClassVar: 56d.  If a field is a ‘ClassVar’, it is
excluded from consideration as a field and is ignored by the dataclass
mechanisms.  Such ‘ClassVar’ pseudo-fields are not returned by the
module-level *note fields(): 191d. function.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0526/


File: python.info,  Node: Init-only variables,  Next: Frozen instances,  Prev: Class variables,  Up: dataclasses — Data Classes

5.29.7.4 Init-only variables
............................

Another place where *note @dataclass: 4e2. inspects a type annotation is
to determine if a field is an init-only variable.  It does this by
seeing if the type of a field is of type *note InitVar: 1b9c.  If a
field is an *note InitVar: 1b9c, it is considered a pseudo-field called
an init-only field.  As it is not a true field, it is not returned by
the module-level *note fields(): 191d. function.  Init-only fields are
added as parameters to the generated *note __init__(): 8c0. method, and
are passed to the optional *note __post_init__(): 498e. method.  They
are not otherwise used by dataclasses.

For example, suppose a field will be initialized from a database, if a
value is not provided when creating the class:

     @dataclass
     class C:
         i: int
         j: int | None = None
         database: InitVar[DatabaseType | None] = None

         def __post_init__(self, database):
             if self.j is None and database is not None:
                 self.j = database.lookup('j')

     c = C(10, database=my_database)

In this case, *note fields(): 191d. will return *note Field: 1943.
objects for ‘i’ and ‘j’, but not for ‘database’.


File: python.info,  Node: Frozen instances,  Next: Inheritance,  Prev: Init-only variables,  Up: dataclasses — Data Classes

5.29.7.5 Frozen instances
.........................

It is not possible to create truly immutable Python objects.  However,
by passing ‘frozen=True’ to the *note @dataclass: 4e2. decorator you can
emulate immutability.  In that case, dataclasses will add *note
__setattr__(): 2362. and *note __delattr__(): 2363. methods to the
class.  These methods will raise a *note FrozenInstanceError: 498f. when
invoked.

There is a tiny performance penalty when using ‘frozen=True’: *note
__init__(): 8c0. cannot use simple assignment to initialize fields, and
must use ‘object.__setattr__()’.


File: python.info,  Node: Inheritance,  Next: Re-ordering of keyword-only parameters in __init__,  Prev: Frozen instances,  Up: dataclasses — Data Classes

5.29.7.6 Inheritance
....................

When the dataclass is being created by the *note @dataclass: 4e2.
decorator, it looks through all of the class’s base classes in reverse
MRO (that is, starting at *note object: c80.) and, for each dataclass
that it finds, adds the fields from that base class to an ordered
mapping of fields.  After all of the base class fields are added, it
adds its own fields to the ordered mapping.  All of the generated
methods will use this combined, calculated ordered mapping of fields.
Because the fields are in insertion order, derived classes override base
classes.  An example:

     @dataclass
     class Base:
         x: Any = 15.0
         y: int = 0

     @dataclass
     class C(Base):
         z: int = 10
         x: int = 15

The final list of fields is, in order, ‘x’, ‘y’, ‘z’.  The final type of
‘x’ is *note int: 19b, as specified in class ‘C’.

The generated *note __init__(): 8c0. method for ‘C’ will look like:

     def __init__(self, x: int = 15, y: int = 0, z: int = 10):


File: python.info,  Node: Re-ordering of keyword-only parameters in __init__,  Next: Default factory functions,  Prev: Inheritance,  Up: dataclasses — Data Classes

5.29.7.7 Re-ordering of keyword-only parameters in ‘__init__()’
...............................................................

After the parameters needed for *note __init__(): 8c0. are computed, any
keyword-only parameters are moved to come after all regular
(non-keyword-only) parameters.  This is a requirement of how
keyword-only parameters are implemented in Python: they must come after
non-keyword-only parameters.

In this example, ‘Base.y’, ‘Base.w’, and ‘D.t’ are keyword-only fields,
and ‘Base.x’ and ‘D.z’ are regular fields:

     @dataclass
     class Base:
         x: Any = 15.0
         _: KW_ONLY
         y: int = 0
         w: int = 1

     @dataclass
     class D(Base):
         z: int = 10
         t: int = field(kw_only=True, default=0)

The generated ‘__init__()’ method for ‘D’ will look like:

     def __init__(self, x: Any = 15.0, z: int = 10, *, y: int = 0, w: int = 1, t: int = 0):

Note that the parameters have been re-ordered from how they appear in
the list of fields: parameters derived from regular fields are followed
by parameters derived from keyword-only fields.

The relative ordering of keyword-only parameters is maintained in the
re-ordered ‘__init__()’ parameter list.


File: python.info,  Node: Default factory functions,  Next: Mutable default values,  Prev: Re-ordering of keyword-only parameters in __init__,  Up: dataclasses — Data Classes

5.29.7.8 Default factory functions
..................................

If a *note field(): 1942. specifies a 'default_factory', it is called
with zero arguments when a default value for the field is needed.  For
example, to create a new instance of a list, use:

     mylist: list = field(default_factory=list)

If a field is excluded from *note __init__(): 8c0. (using ‘init=False’)
and the field also specifies 'default_factory', then the default factory
function will always be called from the generated ‘__init__()’ function.
This happens because there is no other way to give the field an initial
value.


File: python.info,  Node: Mutable default values,  Next: Descriptor-typed fields,  Prev: Default factory functions,  Up: dataclasses — Data Classes

5.29.7.9 Mutable default values
...............................

Python stores default member variable values in class attributes.
Consider this example, not using dataclasses:

     class C:
         x = []
         def add(self, element):
             self.x.append(element)

     o1 = C()
     o2 = C()
     o1.add(1)
     o2.add(2)
     assert o1.x == [1, 2]
     assert o1.x is o2.x

Note that the two instances of class ‘C’ share the same class variable
‘x’, as expected.

Using dataclasses, 'if' this code was valid:

     @dataclass
     class D:
         x: list = []      # This code raises ValueError
         def add(self, element):
             self.x.append(element)

it would generate code similar to:

     class D:
         x = []
         def __init__(self, x=x):
             self.x = x
         def add(self, element):
             self.x.append(element)

     assert D().x is D().x

This has the same issue as the original example using class ‘C’.  That
is, two instances of class ‘D’ that do not specify a value for ‘x’ when
creating a class instance will share the same copy of ‘x’.  Because
dataclasses just use normal Python class creation they also share this
behavior.  There is no general way for Data Classes to detect this
condition.  Instead, the *note @dataclass: 4e2. decorator will raise a
*note ValueError: 2ec. if it detects an unhashable default parameter.
The assumption is that if a value is unhashable, it is mutable.  This is
a partial solution, but it does protect against many common errors.

Using default factory functions is a way to create new instances of
mutable types as default values for fields:

     @dataclass
     class D:
         x: list = field(default_factory=list)

     assert D().x is not D().x

Cambiato nella versione 3.11: Instead of looking for and disallowing
objects of type *note list: 24d, *note dict: 183, or *note set: 184,
unhashable objects are now not allowed as default values.  Unhashability
is used to approximate mutability.


File: python.info,  Node: Descriptor-typed fields,  Prev: Mutable default values,  Up: dataclasses — Data Classes

5.29.7.10 Descriptor-typed fields
.................................

Fields that are assigned *note descriptor objects: e4b. as their default
value have the following special behaviors:

   * The value for the field passed to the dataclass’s *note __init__():
     8c0. method is passed to the descriptor’s *note __set__(): 239b.
     method rather than overwriting the descriptor object.

   * Similarly, when getting or setting the field, the descriptor’s
     *note __get__(): 16ef. or ‘__set__()’ method is called rather than
     returning or overwriting the descriptor object.

   * To determine whether a field contains a default value, *note
     @dataclass: 4e2. will call the descriptor’s ‘__get__()’ method
     using its class access form: ‘descriptor.__get__(obj=None,
     type=cls)’.  If the descriptor returns a value in this case, it
     will be used as the field’s default.  On the other hand, if the
     descriptor raises *note AttributeError: 5f0. in this situation, no
     default value will be provided for the field.

     class IntConversionDescriptor:
         def __init__(self, *, default):
             self._default = default

         def __set_name__(self, owner, name):
             self._name = "_" + name

         def __get__(self, obj, type):
             if obj is None:
                 return self._default

             return getattr(obj, self._name, self._default)

         def __set__(self, obj, value):
             setattr(obj, self._name, int(value))

     @dataclass
     class InventoryItem:
         quantity_on_hand: IntConversionDescriptor = IntConversionDescriptor(default=100)

     i = InventoryItem()
     print(i.quantity_on_hand)   # 100
     i.quantity_on_hand = 2.5    # calls __set__ with 2.5
     print(i.quantity_on_hand)   # 2

Note that if a field is annotated with a descriptor type, but is not
assigned a descriptor object as its default value, the field will act
like a normal field.


File: python.info,  Node: contextlib — Utilities for with-statement contexts,  Next: abc — Abstract Base Classes,  Prev: dataclasses — Data Classes,  Up: Python Runtime Services

5.29.8 ‘contextlib’ — Utilities for ‘with’-statement contexts
-------------------------------------------------------------

'Source code:' Lib/contextlib.py(1)

__________________________________________________________________

This module provides utilities for common tasks involving the *note
with: 186. statement.  For more information see also *note Tipi di
gestori di contesti: 23f0. and *note With Statement Context Managers:
23ee.

* Menu:

* Utilities::
* Examples and Recipes: Examples and Recipes<3>.
* Single use, reusable and reentrant context managers: Single use reusable and reentrant context managers.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/contextlib.py


File: python.info,  Node: Utilities,  Next: Examples and Recipes<3>,  Up: contextlib — Utilities for with-statement contexts

5.29.8.1 Utilities
..................

Functions and classes provided:

 -- Classe: contextlib.AbstractContextManager

     An *note abstract base class: 13be. for classes that implement
     *note object.__enter__(): 7e5. and *note object.__exit__(): 1508.
     A default implementation for *note object.__enter__(): 7e5. is
     provided which returns ‘self’ while *note object.__exit__(): 1508.
     is an abstract method which by default returns ‘None’.  See also
     the definition of *note Tipi di gestori di contesti: 23f0.

     Added in version 3.6.

 -- Classe: contextlib.AbstractAsyncContextManager

     An *note abstract base class: 13be. for classes that implement
     *note object.__aenter__(): 2401. and *note object.__aexit__():
     1989.  A default implementation for *note object.__aenter__():
     2401. is provided which returns ‘self’ while *note
     object.__aexit__(): 1989. is an abstract method which by default
     returns ‘None’.  See also the definition of *note Asynchronous
     Context Managers: 813.

     Added in version 3.7.

 -- Funzione: @contextlib.contextmanager

     This function is a *note decorator: 93b. that can be used to define
     a factory function for *note with: 186. statement context managers,
     without needing to create a class or separate *note __enter__():
     7e5. and *note __exit__(): 1508. methods.

     While many objects natively support use in with statements,
     sometimes a resource needs to be managed that isn’t a context
     manager in its own right, and doesn’t implement a ‘close()’ method
     for use with ‘contextlib.closing’.

     An abstract example would be the following to ensure correct
     resource management:

          from contextlib import contextmanager

          @contextmanager
          def managed_resource(*args, **kwds):
              # Code to acquire resource, e.g.:
              resource = acquire_resource(*args, **kwds)
              try:
                  yield resource
              finally:
                  # Code to release resource, e.g.:
                  release_resource(resource)

     The function can then be used like this:

          >>> with managed_resource(timeout=3600) as resource:
          ...     # Resource is released at the end of this block,
          ...     # even if code in the block raises an exception

     The function being decorated must return a *note generator:
     1263.-iterator when called.  This iterator must yield exactly one
     value, which will be bound to the targets in the *note with: 186.
     statement’s ‘as’ clause, if any.

     At the point where the generator yields, the block nested in the
     *note with: 186. statement is executed.  The generator is then
     resumed after the block is exited.  If an unhandled exception
     occurs in the block, it is reraised inside the generator at the
     point where the yield occurred.  Thus, you can use a *note try:
     8f9.…*note except: 1ab.…*note finally: 1b0. statement to trap the
     error (if any), or ensure that some cleanup takes place.  If an
     exception is trapped merely in order to log it or to perform some
     action (rather than to suppress it entirely), the generator must
     reraise that exception.  Otherwise the generator context manager
     will indicate to the ‘with’ statement that the exception has been
     handled, and execution will resume with the statement immediately
     following the ‘with’ statement.

     *note contextmanager(): 140a. uses *note ContextDecorator: 1409. so
     the context managers it creates can be used as decorators as well
     as in *note with: 186. statements.  When used as a decorator, a new
     generator instance is implicitly created on each function call
     (this allows the otherwise «one-shot» context managers created by
     *note contextmanager(): 140a. to meet the requirement that context
     managers support multiple invocations in order to be used as
     decorators).

     Cambiato nella versione 3.2: Use of *note ContextDecorator: 1409.

 -- Funzione: @contextlib.asynccontextmanager

     Similar to *note contextmanager(): 140a, but creates an *note
     asynchronous context manager: 813.

     This function is a *note decorator: 93b. that can be used to define
     a factory function for *note async with: 185. statement
     asynchronous context managers, without needing to create a class or
     separate *note __aenter__(): 2401. and *note __aexit__(): 1989.
     methods.  It must be applied to an *note asynchronous generator:
     2476. function.

     A simple example:

          from contextlib import asynccontextmanager

          @asynccontextmanager
          async def get_connection():
              conn = await acquire_db_connection()
              try:
                  yield conn
              finally:
                  await release_db_connection(conn)

          async def get_all_users():
              async with get_connection() as conn:
                  return conn.query('SELECT ...')

     Added in version 3.7.

     Context managers defined with *note asynccontextmanager(): d21. can
     be used either as decorators or with *note async with: 185.
     statements:

          import time
          from contextlib import asynccontextmanager

          @asynccontextmanager
          async def timeit():
              now = time.monotonic()
              try:
                  yield
              finally:
                  print(f'it took {time.monotonic() - now}s to run')

          @timeit()
          async def main():
              # ... async code ...

     When used as a decorator, a new generator instance is implicitly
     created on each function call.  This allows the otherwise
     «one-shot» context managers created by *note asynccontextmanager():
     d21. to meet the requirement that context managers support multiple
     invocations in order to be used as decorators.

     Cambiato nella versione 3.10: Async context managers created with
     *note asynccontextmanager(): d21. can be used as decorators.

 -- Funzione: contextlib.closing (thing)

     Return a context manager that closes 'thing' upon completion of the
     block.  This is basically equivalent to:

          from contextlib import contextmanager

          @contextmanager
          def closing(thing):
              try:
                  yield thing
              finally:
                  thing.close()

     And lets you write code like this:

          from contextlib import closing
          from urllib.request import urlopen

          with closing(urlopen('https://www.python.org')) as page:
              for line in page:
                  print(line)

     without needing to explicitly close ‘page’.  Even if an error
     occurs, ‘page.close()’ will be called when the *note with: 186.
     block is exited.

          Nota: Most types managing resources support the *note context
          manager: 1e1. protocol, which closes 'thing' on leaving the
          *note with: 186. statement.  As such, ‘closing()’ is most
          useful for third party types that don’t support context
          managers.  This example is purely for illustration purposes,
          as *note urlopen(): 307. would normally be used in a context
          manager.

 -- Funzione: contextlib.aclosing (thing)

     Return an async context manager that calls the ‘aclose()’ method of
     'thing' upon completion of the block.  This is basically equivalent
     to:

          from contextlib import asynccontextmanager

          @asynccontextmanager
          async def aclosing(thing):
              try:
                  yield thing
              finally:
                  await thing.aclose()

     Significantly, ‘aclosing()’ supports deterministic cleanup of async
     generators when they happen to exit early by *note break: 17f. or
     an exception.  For example:

          from contextlib import aclosing

          async with aclosing(my_generator()) as values:
              async for value in values:
                  if value == 42:
                      break

     This pattern ensures that the generator’s async exit code is
     executed in the same context as its iterations (so that exceptions
     and context variables work as expected, and the exit code isn’t run
     after the lifetime of some task it depends on).

     Added in version 3.10.

 -- Funzione: contextlib.nullcontext (enter_result=None)

     Return a context manager that returns 'enter_result' from
     ‘__enter__’, but otherwise does nothing.  It is intended to be used
     as a stand-in for an optional context manager, for example:

          def myfunction(arg, ignore_exceptions=False):
              if ignore_exceptions:
                  # Use suppress to ignore all exceptions.
                  cm = contextlib.suppress(Exception)
              else:
                  # Do not ignore any exceptions, cm has no effect.
                  cm = contextlib.nullcontext()
              with cm:
                  # Do something

     An example using 'enter_result':

          def process_file(file_or_path):
              if isinstance(file_or_path, str):
                  # If string, open file
                  cm = open(file_or_path)
              else:
                  # Caller is responsible for closing file
                  cm = nullcontext(file_or_path)

              with cm as file:
                  # Perform processing on the file

     It can also be used as a stand-in for *note asynchronous context
     managers: 813.:

          async def send_http(session=None):
              if not session:
                  # If no http session, create it with aiohttp
                  cm = aiohttp.ClientSession()
              else:
                  # Caller is responsible for closing the session
                  cm = nullcontext(session)

              async with cm as session:
                  # Send http requests with session

     Added in version 3.7.

     Cambiato nella versione 3.10: *note asynchronous context manager:
     7f1. support was added.

 -- Funzione: contextlib.suppress (*exceptions)

     Return a context manager that suppresses any of the specified
     exceptions if they occur in the body of a ‘with’ statement and then
     resumes execution with the first statement following the end of the
     ‘with’ statement.

     As with any other mechanism that completely suppresses exceptions,
     this context manager should be used only to cover very specific
     errors where silently continuing with program execution is known to
     be the right thing to do.

     For example:

          from contextlib import suppress

          with suppress(FileNotFoundError):
              os.remove('somefile.tmp')

          with suppress(FileNotFoundError):
              os.remove('someotherfile.tmp')

     This code is equivalent to:

          try:
              os.remove('somefile.tmp')
          except FileNotFoundError:
              pass

          try:
              os.remove('someotherfile.tmp')
          except FileNotFoundError:
              pass

     This context manager is *note reentrant: 49a1.

     If the code within the ‘with’ block raises a *note
     BaseExceptionGroup: 566, suppressed exceptions are removed from the
     group.  Any exceptions of the group which are not suppressed are
     re-raised in a new group which is created using the original
     group’s *note derive(): 1a1f. method.

     Added in version 3.4.

     Cambiato nella versione 3.12: ‘suppress’ now supports suppressing
     exceptions raised as part of a *note BaseExceptionGroup: 566.

 -- Funzione: contextlib.redirect_stdout (new_target)

     Context manager for temporarily redirecting *note sys.stdout: ccf.
     to another file or file-like object.

     This tool adds flexibility to existing functions or classes whose
     output is hardwired to stdout.

     For example, the output of *note help(): ad6. normally is sent to
     'sys.stdout'.  You can capture that output in a string by
     redirecting the output to an *note io.StringIO: 112b. object.  The
     replacement stream is returned from the ‘__enter__’ method and so
     is available as the target of the *note with: 186. statement:

          with redirect_stdout(io.StringIO()) as f:
              help(pow)
          s = f.getvalue()

     To send the output of *note help(): ad6. to a file on disk,
     redirect the output to a regular file:

          with open('help.txt', 'w') as f:
              with redirect_stdout(f):
                  help(pow)

     To send the output of *note help(): ad6. to 'sys.stderr':

          with redirect_stdout(sys.stderr):
              help(pow)

     Note that the global side effect on *note sys.stdout: ccf. means
     that this context manager is not suitable for use in library code
     and most threaded applications.  It also has no effect on the
     output of subprocesses.  However, it is still a useful approach for
     many utility scripts.

     This context manager is *note reentrant: 49a1.

     Added in version 3.4.

 -- Funzione: contextlib.redirect_stderr (new_target)

     Similar to *note redirect_stdout(): fe9. but redirecting *note
     sys.stderr: b35. to another file or file-like object.

     This context manager is *note reentrant: 49a1.

     Added in version 3.5.

 -- Funzione: contextlib.chdir (path)

     Non parallel-safe context manager to change the current working
     directory.  As this changes a global state, the working directory,
     it is not suitable for use in most threaded or async contexts.  It
     is also not suitable for most non-linear code execution, like
     generators, where the program execution is temporarily relinquished
     – unless explicitly desired, you should not yield when this context
     manager is active.

     This is a simple wrapper around *note chdir(): 822, it changes the
     current working directory upon entering and restores the old one on
     exit.

     This context manager is *note reentrant: 49a1.

     Added in version 3.11.

 -- Classe: contextlib.ContextDecorator

     A base class that enables a context manager to also be used as a
     decorator.

     Context managers inheriting from ‘ContextDecorator’ have to
     implement ‘__enter__’ and ‘__exit__’ as normal.  ‘__exit__’ retains
     its optional exception handling even when used as a decorator.

     ‘ContextDecorator’ is used by *note contextmanager(): 140a, so you
     get this functionality automatically.

     Example of ‘ContextDecorator’:

          from contextlib import ContextDecorator

          class mycontext(ContextDecorator):
              def __enter__(self):
                  print('Starting')
                  return self

              def __exit__(self, *exc):
                  print('Finishing')
                  return False

     The class can then be used like this:

          >>> @mycontext()
          ... def function():
          ...     print('The bit in the middle')
          ...
          >>> function()
          Starting
          The bit in the middle
          Finishing

          >>> with mycontext():
          ...     print('The bit in the middle')
          ...
          Starting
          The bit in the middle
          Finishing

     This change is just syntactic sugar for any construct of the
     following form:

          def f():
              with cm():
                  # Do stuff

     ‘ContextDecorator’ lets you instead write:

          @cm()
          def f():
              # Do stuff

     It makes it clear that the ‘cm’ applies to the whole function,
     rather than just a piece of it (and saving an indentation level is
     nice, too).

     Existing context managers that already have a base class can be
     extended by using ‘ContextDecorator’ as a mixin class:

          from contextlib import ContextDecorator

          class mycontext(ContextBaseClass, ContextDecorator):
              def __enter__(self):
                  return self

              def __exit__(self, *exc):
                  return False

          Nota: As the decorated function must be able to be called
          multiple times, the underlying context manager must support
          use in multiple *note with: 186. statements.  If this is not
          the case, then the original construct with the explicit ‘with’
          statement inside the function should be used.

     Added in version 3.2.

 -- Classe: contextlib.AsyncContextDecorator

     Similar to *note ContextDecorator: 1409. but only for asynchronous
     functions.

     Example of ‘AsyncContextDecorator’:

          from asyncio import run
          from contextlib import AsyncContextDecorator

          class mycontext(AsyncContextDecorator):
              async def __aenter__(self):
                  print('Starting')
                  return self

              async def __aexit__(self, *exc):
                  print('Finishing')
                  return False

     The class can then be used like this:

          >>> @mycontext()
          ... async def function():
          ...     print('The bit in the middle')
          ...
          >>> run(function())
          Starting
          The bit in the middle
          Finishing

          >>> async def function():
          ...    async with mycontext():
          ...         print('The bit in the middle')
          ...
          >>> run(function())
          Starting
          The bit in the middle
          Finishing

     Added in version 3.10.

 -- Classe: contextlib.ExitStack

     A context manager that is designed to make it easy to
     programmatically combine other context managers and cleanup
     functions, especially those that are optional or otherwise driven
     by input data.

     For example, a set of files may easily be handled in a single with
     statement as follows:

          with ExitStack() as stack:
              files = [stack.enter_context(open(fname)) for fname in filenames]
              # All opened files will automatically be closed at the end of
              # the with statement, even if attempts to open files later
              # in the list raise an exception

     The *note __enter__(): 7e5. method returns the *note ExitStack:
     d20. instance, and performs no additional operations.

     Each instance maintains a stack of registered callbacks that are
     called in reverse order when the instance is closed (either
     explicitly or implicitly at the end of a *note with: 186.
     statement).  Note that callbacks are 'not' invoked implicitly when
     the context stack instance is garbage collected.

     This stack model is used so that context managers that acquire
     their resources in their ‘__init__’ method (such as file objects)
     can be handled correctly.

     Since registered callbacks are invoked in the reverse order of
     registration, this ends up behaving as if multiple nested *note
     with: 186. statements had been used with the registered set of
     callbacks.  This even extends to exception handling - if an inner
     callback suppresses or replaces an exception, then outer callbacks
     will be passed arguments based on that updated state.

     This is a relatively low level API that takes care of the details
     of correctly unwinding the stack of exit callbacks.  It provides a
     suitable foundation for higher level context managers that
     manipulate the exit stack in application specific ways.

     Added in version 3.3.

      -- Metodo: enter_context (cm)

          Enters a new context manager and adds its *note __exit__():
          1508. method to the callback stack.  The return value is the
          result of the context manager’s own *note __enter__(): 7e5.
          method.

          These context managers may suppress exceptions just as they
          normally would if used directly as part of a *note with: 186.
          statement.

          Cambiato nella versione 3.11: Raises *note TypeError: 198.
          instead of *note AttributeError: 5f0. if 'cm' is not a context
          manager.

      -- Metodo: push (exit)

          Adds a context manager’s *note __exit__(): 1508. method to the
          callback stack.

          As ‘__enter__’ is 'not' invoked, this method can be used to
          cover part of an *note __enter__(): 7e5. implementation with a
          context manager’s own *note __exit__(): 1508. method.

          If passed an object that is not a context manager, this method
          assumes it is a callback with the same signature as a context
          manager’s *note __exit__(): 1508. method and adds it directly
          to the callback stack.

          By returning true values, these callbacks can suppress
          exceptions the same way context manager *note __exit__():
          1508. methods can.

          The passed in object is returned from the function, allowing
          this method to be used as a function decorator.

      -- Metodo: callback (callback, /, *args, **kwds)

          Accepts an arbitrary callback function and arguments and adds
          it to the callback stack.

          Unlike the other methods, callbacks added this way cannot
          suppress exceptions (as they are never passed the exception
          details).

          The passed in callback is returned from the function, allowing
          this method to be used as a function decorator.

      -- Metodo: pop_all ()

          Transfers the callback stack to a fresh *note ExitStack: d20.
          instance and returns it.  No callbacks are invoked by this
          operation - instead, they will now be invoked when the new
          stack is closed (either explicitly or implicitly at the end of
          a *note with: 186. statement).

          For example, a group of files can be opened as an «all or
          nothing» operation as follows:

               with ExitStack() as stack:
                   files = [stack.enter_context(open(fname)) for fname in filenames]
                   # Hold onto the close method, but don't call it yet.
                   close_files = stack.pop_all().close
                   # If opening any file fails, all previously opened files will be
                   # closed automatically. If all files are opened successfully,
                   # they will remain open even after the with statement ends.
                   # close_files() can then be invoked explicitly to close them all.

      -- Metodo: close ()

          Immediately unwinds the callback stack, invoking callbacks in
          the reverse order of registration.  For any context managers
          and exit callbacks registered, the arguments passed in will
          indicate that no exception occurred.

 -- Classe: contextlib.AsyncExitStack

     An *note asynchronous context manager: 813, similar to *note
     ExitStack: d20, that supports combining both synchronous and
     asynchronous context managers, as well as having coroutines for
     cleanup logic.

     The *note close(): 49a4. method is not implemented; *note aclose():
     49a5. must be used instead.

      -- Metodo: async enter_async_context (cm)

          Similar to *note ExitStack.enter_context(): 7ef. but expects
          an asynchronous context manager.

          Cambiato nella versione 3.11: Raises *note TypeError: 198.
          instead of *note AttributeError: 5f0. if 'cm' is not an
          asynchronous context manager.

      -- Metodo: push_async_exit (exit)

          Similar to *note ExitStack.push(): 49a2. but expects either an
          asynchronous context manager or a coroutine function.

      -- Metodo: push_async_callback (callback, /, *args, **kwds)

          Similar to *note ExitStack.callback(): c78. but expects a
          coroutine function.

      -- Metodo: async aclose ()

          Similar to *note ExitStack.close(): 49a4. but properly handles
          awaitables.

     Continuing the example for *note asynccontextmanager(): d21.:

          async with AsyncExitStack() as stack:
              connections = [await stack.enter_async_context(get_connection())
                  for i in range(5)]
              # All opened connections will automatically be released at the end of
              # the async with statement, even if attempts to open a connection
              # later in the list raise an exception.

     Added in version 3.7.


File: python.info,  Node: Examples and Recipes<3>,  Next: Single use reusable and reentrant context managers,  Prev: Utilities,  Up: contextlib — Utilities for with-statement contexts

5.29.8.2 Examples and Recipes
.............................

This section describes some examples and recipes for making effective
use of the tools provided by *note contextlib: 27.

* Menu:

* Supporting a variable number of context managers::
* Catching exceptions from __enter__ methods::
* Cleaning up in an __enter__ implementation::
* Replacing any use of try-finally and flag variables::
* Using a context manager as a function decorator::


File: python.info,  Node: Supporting a variable number of context managers,  Next: Catching exceptions from __enter__ methods,  Up: Examples and Recipes<3>

5.29.8.3 Supporting a variable number of context managers
.........................................................

The primary use case for *note ExitStack: d20. is the one given in the
class documentation: supporting a variable number of context managers
and other cleanup operations in a single *note with: 186. statement.
The variability may come from the number of context managers needed
being driven by user input (such as opening a user specified collection
of files), or from some of the context managers being optional:

     with ExitStack() as stack:
         for resource in resources:
             stack.enter_context(resource)
         if need_special_resource():
             special = acquire_special_resource()
             stack.callback(release_special_resource, special)
         # Perform operations that use the acquired resources

As shown, *note ExitStack: d20. also makes it quite easy to use *note
with: 186. statements to manage arbitrary resources that don’t natively
support the context management protocol.


File: python.info,  Node: Catching exceptions from __enter__ methods,  Next: Cleaning up in an __enter__ implementation,  Prev: Supporting a variable number of context managers,  Up: Examples and Recipes<3>

5.29.8.4 Catching exceptions from ‘__enter__’ methods
.....................................................

It is occasionally desirable to catch exceptions from an ‘__enter__’
method implementation, 'without' inadvertently catching exceptions from
the *note with: 186. statement body or the context manager’s ‘__exit__’
method.  By using *note ExitStack: d20. the steps in the context
management protocol can be separated slightly in order to allow this:

     stack = ExitStack()
     try:
         x = stack.enter_context(cm)
     except Exception:
         # handle __enter__ exception
     else:
         with stack:
             # Handle normal case

Actually needing to do this is likely to indicate that the underlying
API should be providing a direct resource management interface for use
with *note try: 8f9./*note except: 1ab./*note finally: 1b0. statements,
but not all APIs are well designed in that regard.  When a context
manager is the only resource management API provided, then *note
ExitStack: d20. can make it easier to handle various situations that
can’t be handled directly in a *note with: 186. statement.


File: python.info,  Node: Cleaning up in an __enter__ implementation,  Next: Replacing any use of try-finally and flag variables,  Prev: Catching exceptions from __enter__ methods,  Up: Examples and Recipes<3>

5.29.8.5 Cleaning up in an ‘__enter__’ implementation
.....................................................

As noted in the documentation of *note ExitStack.push(): 49a2, this
method can be useful in cleaning up an already allocated resource if
later steps in the *note __enter__(): 7e5. implementation fail.

Here’s an example of doing this for a context manager that accepts
resource acquisition and release functions, along with an optional
validation function, and maps them to the context management protocol:

     from contextlib import contextmanager, AbstractContextManager, ExitStack

     class ResourceManager(AbstractContextManager):

         def __init__(self, acquire_resource, release_resource, check_resource_ok=None):
             self.acquire_resource = acquire_resource
             self.release_resource = release_resource
             if check_resource_ok is None:
                 def check_resource_ok(resource):
                     return True
             self.check_resource_ok = check_resource_ok

         @contextmanager
         def _cleanup_on_error(self):
             with ExitStack() as stack:
                 stack.push(self)
                 yield
                 # The validation check passed and didn't raise an exception
                 # Accordingly, we want to keep the resource, and pass it
                 # back to our caller
                 stack.pop_all()

         def __enter__(self):
             resource = self.acquire_resource()
             with self._cleanup_on_error():
                 if not self.check_resource_ok(resource):
                     msg = "Failed validation for {!r}"
                     raise RuntimeError(msg.format(resource))
             return resource

         def __exit__(self, *exc_details):
             # We don't need to duplicate any of our resource release logic
             self.release_resource()


File: python.info,  Node: Replacing any use of try-finally and flag variables,  Next: Using a context manager as a function decorator,  Prev: Cleaning up in an __enter__ implementation,  Up: Examples and Recipes<3>

5.29.8.6 Replacing any use of ‘try-finally’ and flag variables
..............................................................

A pattern you will sometimes see is a ‘try-finally’ statement with a
flag variable to indicate whether or not the body of the ‘finally’
clause should be executed.  In its simplest form (that can’t already be
handled just by using an ‘except’ clause instead), it looks something
like this:

     cleanup_needed = True
     try:
         result = perform_operation()
         if result:
             cleanup_needed = False
     finally:
         if cleanup_needed:
             cleanup_resources()

As with any ‘try’ statement based code, this can cause problems for
development and review, because the setup code and the cleanup code can
end up being separated by arbitrarily long sections of code.

*note ExitStack: d20. makes it possible to instead register a callback
for execution at the end of a ‘with’ statement, and then later decide to
skip executing that callback:

     from contextlib import ExitStack

     with ExitStack() as stack:
         stack.callback(cleanup_resources)
         result = perform_operation()
         if result:
             stack.pop_all()

This allows the intended cleanup behaviour to be made explicit up front,
rather than requiring a separate flag variable.

If a particular application uses this pattern a lot, it can be
simplified even further by means of a small helper class:

     from contextlib import ExitStack

     class Callback(ExitStack):
         def __init__(self, callback, /, *args, **kwds):
             super().__init__()
             self.callback(callback, *args, **kwds)

         def cancel(self):
             self.pop_all()

     with Callback(cleanup_resources) as cb:
         result = perform_operation()
         if result:
             cb.cancel()

If the resource cleanup isn’t already neatly bundled into a standalone
function, then it is still possible to use the decorator form of *note
ExitStack.callback(): c78. to declare the resource cleanup in advance:

     from contextlib import ExitStack

     with ExitStack() as stack:
         @stack.callback
         def cleanup_resources():
             ...
         result = perform_operation()
         if result:
             stack.pop_all()

Due to the way the decorator protocol works, a callback function
declared this way cannot take any parameters.  Instead, any resources to
be released must be accessed as closure variables.


File: python.info,  Node: Using a context manager as a function decorator,  Prev: Replacing any use of try-finally and flag variables,  Up: Examples and Recipes<3>

5.29.8.7 Using a context manager as a function decorator
........................................................

*note ContextDecorator: 1409. makes it possible to use a context manager
in both an ordinary ‘with’ statement and also as a function decorator.

For example, it is sometimes useful to wrap functions or groups of
statements with a logger that can track the time of entry and time of
exit.  Rather than writing both a function decorator and a context
manager for the task, inheriting from *note ContextDecorator: 1409.
provides both capabilities in a single definition:

     from contextlib import ContextDecorator
     import logging

     logging.basicConfig(level=logging.INFO)

     class track_entry_and_exit(ContextDecorator):
         def __init__(self, name):
             self.name = name

         def __enter__(self):
             logging.info('Entering: %s', self.name)

         def __exit__(self, exc_type, exc, exc_tb):
             logging.info('Exiting: %s', self.name)

Instances of this class can be used as both a context manager:

     with track_entry_and_exit('widget loader'):
         print('Some time consuming activity goes here')
         load_widget()

And also as a function decorator:

     @track_entry_and_exit('widget loader')
     def activity():
         print('Some time consuming activity goes here')
         load_widget()

Note that there is one additional limitation when using context managers
as function decorators: there’s no way to access the return value of
*note __enter__(): 7e5.  If that value is needed, then it is still
necessary to use an explicit ‘with’ statement.

Vedi anche
..........

PEP 343(1) - The «with» statement

     The specification, background, and examples for the Python *note
     with: 186. statement.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0343/


File: python.info,  Node: Single use reusable and reentrant context managers,  Prev: Examples and Recipes<3>,  Up: contextlib — Utilities for with-statement contexts

5.29.8.8 Single use, reusable and reentrant context managers
............................................................

Most context managers are written in a way that means they can only be
used effectively in a *note with: 186. statement once.  These single use
context managers must be created afresh each time they’re used -
attempting to use them a second time will trigger an exception or
otherwise not work correctly.

This common limitation means that it is generally advisable to create
context managers directly in the header of the *note with: 186.
statement where they are used (as shown in all of the usage examples
above).

Files are an example of effectively single use context managers, since
the first *note with: 186. statement will close the file, preventing any
further IO operations using that file object.

Context managers created using *note contextmanager(): 140a. are also
single use context managers, and will complain about the underlying
generator failing to yield if an attempt is made to use them a second
time:

     >>> from contextlib import contextmanager
     >>> @contextmanager
     ... def singleuse():
     ...     print("Before")
     ...     yield
     ...     print("After")
     ...
     >>> cm = singleuse()
     >>> with cm:
     ...     pass
     ...
     Before
     After
     >>> with cm:
     ...     pass
     ...
     Traceback (most recent call last):
         ...
     RuntimeError: generator didn't yield

* Menu:

* Reentrant context managers::
* Reusable context managers::


File: python.info,  Node: Reentrant context managers,  Next: Reusable context managers,  Up: Single use reusable and reentrant context managers

5.29.8.9 Reentrant context managers
...................................

More sophisticated context managers may be «reentrant».  These context
managers can not only be used in multiple *note with: 186. statements,
but may also be used 'inside' a ‘with’ statement that is already using
the same context manager.

*note threading.RLock: 32e. is an example of a reentrant context
manager, as are *note suppress(): 112a, *note redirect_stdout(): fe9,
and *note chdir(): 821.  Here’s a very simple example of reentrant use:

     >>> from contextlib import redirect_stdout
     >>> from io import StringIO
     >>> stream = StringIO()
     >>> write_to_stream = redirect_stdout(stream)
     >>> with write_to_stream:
     ...     print("This is written to the stream rather than stdout")
     ...     with write_to_stream:
     ...         print("This is also written to the stream")
     ...
     >>> print("This is written directly to stdout")
     This is written directly to stdout
     >>> print(stream.getvalue())
     This is written to the stream rather than stdout
     This is also written to the stream

Real world examples of reentrancy are more likely to involve multiple
functions calling each other and hence be far more complicated than this
example.

Note also that being reentrant is 'not' the same thing as being thread
safe.  *note redirect_stdout(): fe9, for example, is definitely not
thread safe, as it makes a global modification to the system state by
binding *note sys.stdout: ccf. to a different stream.


File: python.info,  Node: Reusable context managers,  Prev: Reentrant context managers,  Up: Single use reusable and reentrant context managers

5.29.8.10 Reusable context managers
...................................

Distinct from both single use and reentrant context managers are
«reusable» context managers (or, to be completely explicit, «reusable,
but not reentrant» context managers, since reentrant context managers
are also reusable).  These context managers support being used multiple
times, but will fail (or otherwise not work correctly) if the specific
context manager instance has already been used in a containing with
statement.

*note threading.Lock: 19dc. is an example of a reusable, but not
reentrant, context manager (for a reentrant lock, it is necessary to use
*note threading.RLock: 32e. instead).

Another example of a reusable, but not reentrant, context manager is
*note ExitStack: d20, as it invokes 'all' currently registered callbacks
when leaving any with statement, regardless of where those callbacks
were added:

     >>> from contextlib import ExitStack
     >>> stack = ExitStack()
     >>> with stack:
     ...     stack.callback(print, "Callback: from first context")
     ...     print("Leaving first context")
     ...
     Leaving first context
     Callback: from first context
     >>> with stack:
     ...     stack.callback(print, "Callback: from second context")
     ...     print("Leaving second context")
     ...
     Leaving second context
     Callback: from second context
     >>> with stack:
     ...     stack.callback(print, "Callback: from outer context")
     ...     with stack:
     ...         stack.callback(print, "Callback: from inner context")
     ...         print("Leaving inner context")
     ...     print("Leaving outer context")
     ...
     Leaving inner context
     Callback: from inner context
     Callback: from outer context
     Leaving outer context

As the output from the example shows, reusing a single stack object
across multiple with statements works correctly, but attempting to nest
them will cause the stack to be cleared at the end of the innermost with
statement, which is unlikely to be desirable behaviour.

Using separate *note ExitStack: d20. instances instead of reusing a
single instance avoids that problem:

     >>> from contextlib import ExitStack
     >>> with ExitStack() as outer_stack:
     ...     outer_stack.callback(print, "Callback: from outer context")
     ...     with ExitStack() as inner_stack:
     ...         inner_stack.callback(print, "Callback: from inner context")
     ...         print("Leaving inner context")
     ...     print("Leaving outer context")
     ...
     Leaving inner context
     Callback: from inner context
     Leaving outer context
     Callback: from outer context


File: python.info,  Node: abc — Abstract Base Classes,  Next: atexit — Exit handlers,  Prev: contextlib — Utilities for with-statement contexts,  Up: Python Runtime Services

5.29.9 ‘abc’ — Abstract Base Classes
------------------------------------

'Source code:' Lib/abc.py(1)

__________________________________________________________________

This module provides the infrastructure for defining *note abstract base
classes: 13be. (ABCs) in Python, as outlined in PEP 3119(2); see the PEP
for why this was added to Python.  (See also PEP 3141(3) and the *note
numbers: a2. module regarding a type hierarchy for numbers based on
ABCs.)

The *note collections: 1e. module has some concrete classes that derive
from ABCs; these can, of course, be further derived.  In addition, the
*note collections.abc: 1f. submodule has some ABCs that can be used to
test whether a class or instance provides a particular interface, for
example, if it is *note hashable: 825. or if it is a *note mapping:
13c3.

This module provides the metaclass *note ABCMeta: 111d. for defining
ABCs and a helper class *note ABC: 111c. to alternatively define ABCs
through inheritance:

 -- Classe: abc.ABC

     A helper class that has *note ABCMeta: 111d. as its metaclass.
     With this class, an abstract base class can be created by simply
     deriving from ‘ABC’ avoiding sometimes confusing metaclass usage,
     for example:

          from abc import ABC

          class MyABC(ABC):
              pass

     Note that the type of ‘ABC’ is still *note ABCMeta: 111d, therefore
     inheriting from ‘ABC’ requires the usual precautions regarding
     metaclass usage, as multiple inheritance may lead to metaclass
     conflicts.  One may also define an abstract base class by passing
     the metaclass keyword and using ‘ABCMeta’ directly, for example:

          from abc import ABCMeta

          class MyABC(metaclass=ABCMeta):
              pass

     Added in version 3.4.

 -- Classe: abc.ABCMeta

     Metaclass for defining Abstract Base Classes (ABCs).

     Use this metaclass to create an ABC. An ABC can be subclassed
     directly, and then acts as a mix-in class.  You can also register
     unrelated concrete classes (even built-in classes) and unrelated
     ABCs as «virtual subclasses» – these and their descendants will be
     considered subclasses of the registering ABC by the built-in *note
     issubclass(): 9c6. function, but the registering ABC won’t show up
     in their MRO (Method Resolution Order) nor will method
     implementations defined by the registering ABC be callable (not
     even via *note super(): 1a6.).  (4)

     Classes created with a metaclass of ‘ABCMeta’ have the following
     method:

      -- Metodo: register (subclass)

          Register 'subclass' as a «virtual subclass» of this ABC. For
          example:

               from abc import ABC

               class MyABC(ABC):
                   pass

               MyABC.register(tuple)

               assert issubclass(tuple, MyABC)
               assert isinstance((), MyABC)

          Cambiato nella versione 3.3: Returns the registered subclass,
          to allow usage as a class decorator.

          Cambiato nella versione 3.4: To detect calls to ‘register()’,
          you can use the *note get_cache_token(): 111b. function.

     You can also override this method in an abstract base class:

      -- Metodo: __subclasshook__ (subclass)

          (Must be defined as a class method.)

          Check whether 'subclass' is considered a subclass of this ABC.
          This means that you can customize the behavior of *note
          issubclass(): 9c6. further without the need to call *note
          register(): 1290. on every class you want to consider a
          subclass of the ABC. (This class method is called from the
          *note __subclasscheck__(): 23ad. method of the ABC.)

          This method should return ‘True’, ‘False’ or *note
          NotImplemented: 1a2.  If it returns ‘True’, the 'subclass' is
          considered a subclass of this ABC. If it returns ‘False’, the
          'subclass' is not considered a subclass of this ABC, even if
          it would normally be one.  If it returns ‘NotImplemented’, the
          subclass check is continued with the usual mechanism.

     For a demonstration of these concepts, look at this example ABC
     definition:

          class Foo:
              def __getitem__(self, index):
                  ...
              def __len__(self):
                  ...
              def get_iterator(self):
                  return iter(self)

          class MyIterable(ABC):

              @abstractmethod
              def __iter__(self):
                  while False:
                      yield None

              def get_iterator(self):
                  return self.__iter__()

              @classmethod
              def __subclasshook__(cls, C):
                  if cls is MyIterable:
                      if any("__iter__" in B.__dict__ for B in C.__mro__):
                          return True
                  return NotImplemented

          MyIterable.register(Foo)

     The ABC ‘MyIterable’ defines the standard iterable method, *note
     __iter__(): e6b, as an abstract method.  The implementation given
     here can still be called from subclasses.  The ‘get_iterator()’
     method is also part of the ‘MyIterable’ abstract base class, but it
     does not have to be overridden in non-abstract derived classes.

     The *note __subclasshook__(): 297e. class method defined here says
     that any class that has an *note __iter__(): e6b. method in its
     *note __dict__: 77e. (or in that of one of its base classes,
     accessed via the *note __mro__: 235e. list) is considered a
     ‘MyIterable’ too.

     Finally, the last line makes ‘Foo’ a virtual subclass of
     ‘MyIterable’, even though it does not define an *note __iter__():
     e6b. method (it uses the old-style iterable protocol, defined in
     terms of *note __len__(): 1777. and *note __getitem__(): 588.).
     Note that this will not make ‘get_iterator’ available as a method
     of ‘Foo’, so it is provided separately.

The ‘abc’ module also provides the following decorator:

 -- Funzione: @abc.abstractmethod

     A decorator indicating abstract methods.

     Using this decorator requires that the class’s metaclass is *note
     ABCMeta: 111d. or is derived from it.  A class that has a metaclass
     derived from ‘ABCMeta’ cannot be instantiated unless all of its
     abstract methods and properties are overridden.  The abstract
     methods can be called using any of the normal “super” call
     mechanisms.  ‘abstractmethod()’ may be used to declare abstract
     methods for properties and descriptors.

     Dynamically adding abstract methods to a class, or attempting to
     modify the abstraction status of a method or class once it is
     created, are only supported using the *note
     update_abstractmethods(): 49b4. function.  The ‘abstractmethod()’
     only affects subclasses derived using regular inheritance; «virtual
     subclasses» registered with the ABC’s *note register(): 1290.
     method are not affected.

     When ‘abstractmethod()’ is applied in combination with other method
     descriptors, it should be applied as the innermost decorator, as
     shown in the following usage examples:

          class C(ABC):
              @abstractmethod
              def my_abstract_method(self, arg1):
                  ...
              @classmethod
              @abstractmethod
              def my_abstract_classmethod(cls, arg2):
                  ...
              @staticmethod
              @abstractmethod
              def my_abstract_staticmethod(arg3):
                  ...

              @property
              @abstractmethod
              def my_abstract_property(self):
                  ...
              @my_abstract_property.setter
              @abstractmethod
              def my_abstract_property(self, val):
                  ...

              @abstractmethod
              def _get_x(self):
                  ...
              @abstractmethod
              def _set_x(self, val):
                  ...
              x = property(_get_x, _set_x)

     In order to correctly interoperate with the abstract base class
     machinery, the descriptor must identify itself as abstract using
     ‘__isabstractmethod__’.  In general, this attribute should be
     ‘True’ if any of the methods used to compose the descriptor are
     abstract.  For example, Python’s built-in *note property: 4b4. does
     the equivalent of:

          class Descriptor:
              ...
              @property
              def __isabstractmethod__(self):
                  return any(getattr(f, '__isabstractmethod__', False) for
                             f in (self._fget, self._fset, self._fdel))

          Nota: Unlike Java abstract methods, these abstract methods may
          have an implementation.  This implementation can be called via
          the *note super(): 1a6. mechanism from the class that
          overrides it.  This could be useful as an end-point for a
          super-call in a framework that uses cooperative
          multiple-inheritance.

The ‘abc’ module also supports the following legacy decorators:

 -- Funzione: @abc.abstractclassmethod

     Added in version 3.2.

     Deprecato dalla versione 3.3: It is now possible to use *note
     classmethod: 48f. with *note abstractmethod(): 128d, making this
     decorator redundant.

     A subclass of the built-in *note classmethod(): 48f, indicating an
     abstract classmethod.  Otherwise it is similar to *note
     abstractmethod(): 128d.

     This special case is deprecated, as the *note classmethod(): 48f.
     decorator is now correctly identified as abstract when applied to
     an abstract method:

          class C(ABC):
              @classmethod
              @abstractmethod
              def my_abstract_classmethod(cls, arg):
                  ...

 -- Funzione: @abc.abstractstaticmethod

     Added in version 3.2.

     Deprecato dalla versione 3.3: It is now possible to use *note
     staticmethod: 453. with *note abstractmethod(): 128d, making this
     decorator redundant.

     A subclass of the built-in *note staticmethod(): 453, indicating an
     abstract staticmethod.  Otherwise it is similar to *note
     abstractmethod(): 128d.

     This special case is deprecated, as the *note staticmethod(): 453.
     decorator is now correctly identified as abstract when applied to
     an abstract method:

          class C(ABC):
              @staticmethod
              @abstractmethod
              def my_abstract_staticmethod(arg):
                  ...

 -- Funzione: @abc.abstractproperty

     Deprecato dalla versione 3.3: It is now possible to use *note
     property: 4b4, *note property.getter(): 19c1, *note
     property.setter(): 19c2. and *note property.deleter(): 19c3. with
     *note abstractmethod(): 128d, making this decorator redundant.

     A subclass of the built-in *note property(): 4b4, indicating an
     abstract property.

     This special case is deprecated, as the *note property(): 4b4.
     decorator is now correctly identified as abstract when applied to
     an abstract method:

          class C(ABC):
              @property
              @abstractmethod
              def my_abstract_property(self):
                  ...

     The above example defines a read-only property; you can also define
     a read-write abstract property by appropriately marking one or more
     of the underlying methods as abstract:

          class C(ABC):
              @property
              def x(self):
                  ...

              @x.setter
              @abstractmethod
              def x(self, val):
                  ...

     If only some components are abstract, only those components need to
     be updated to create a concrete property in a subclass:

          class D(C):
              @C.x.setter
              def x(self, val):
                  ...

The ‘abc’ module also provides the following functions:

 -- Funzione: abc.get_cache_token ()

     Returns the current abstract base class cache token.

     The token is an opaque object (that supports equality testing)
     identifying the current version of the abstract base class cache
     for virtual subclasses.  The token changes with every call to *note
     ABCMeta.register(): 1290. on any ABC.

     Added in version 3.4.

 -- Funzione: abc.update_abstractmethods (cls)

     A function to recalculate an abstract class’s abstraction status.
     This function should be called if a class’s abstract methods have
     been implemented or changed after it was created.  Usually, this
     function should be called from within a class decorator.

     Returns 'cls', to allow usage as a class decorator.

     If 'cls' is not an instance of *note ABCMeta: 111d, does nothing.

          Nota: This function assumes that 'cls'’s superclasses are
          already updated.  It does not update any subclasses.

     Added in version 3.10.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/abc.py

   (2) https://peps.python.org/pep-3119/

   (3) https://peps.python.org/pep-3141/

   (4) C++ programmers should note that Python’s virtual base class
concept is not the same as C++”s.


File: python.info,  Node: atexit — Exit handlers,  Next: traceback — Print or retrieve a stack traceback,  Prev: abc — Abstract Base Classes,  Up: Python Runtime Services

5.29.10 ‘atexit’ — Exit handlers
--------------------------------

__________________________________________________________________

The *note atexit: d. module defines functions to register and unregister
cleanup functions.  Functions thus registered are automatically executed
upon normal interpreter termination.  *note atexit: d. runs these
functions in the 'reverse' order in which they were registered; if you
register ‘A’, ‘B’, and ‘C’, at interpreter termination time they will be
run in the order ‘C’, ‘B’, ‘A’.

'Note:' The functions registered via this module are not called when the
program is killed by a signal not handled by Python, when a Python fatal
internal error is detected, or when *note os._exit(): 26dc. is called.

'Note:' The effect of registering or unregistering functions from within
a cleanup function is undefined.

Cambiato nella versione 3.7: When used with C-API subinterpreters,
registered functions are local to the interpreter they were registered
in.

 -- Funzione: atexit.register (func, *args, **kwargs)

     Register 'func' as a function to be executed at termination.  Any
     optional arguments that are to be passed to 'func' must be passed
     as arguments to *note register(): a80.  It is possible to register
     the same function and arguments more than once.

     At normal program termination (for instance, if *note sys.exit():
     277. is called or the main module’s execution completes), all
     functions registered are called in last in, first out order.  The
     assumption is that lower level modules will normally be imported
     before higher level modules and thus must be cleaned up later.

     If an exception is raised during execution of the exit handlers, a
     traceback is printed (unless *note SystemExit: f3e. is raised) and
     the exception information is saved.  After all exit handlers have
     had a chance to run, the last exception to be raised is re-raised.

     This function returns 'func', which makes it possible to use it as
     a decorator.

          Avvertimento: Starting new threads or calling *note os.fork():
          4b6. from a registered function can lead to race condition
          between the main Python runtime thread freeing thread states
          while internal *note threading: f3. routines or the new
          process try to use that state.  This can lead to crashes
          rather than clean shutdown.

     Cambiato nella versione 3.12: Attempts to start a new thread or
     *note os.fork(): 4b6. a new process in a registered function now
     leads to *note RuntimeError: 244.

 -- Funzione: atexit.unregister (func)

     Remove 'func' from the list of functions to be run at interpreter
     shutdown.  *note unregister(): 1766. silently does nothing if
     'func' was not previously registered.  If 'func' has been
     registered more than once, every occurrence of that function in the
     *note atexit: d. call stack will be removed.  Equality comparisons
     (‘==’) are used internally during unregistration, so function
     references do not need to have matching identities.

Vedi anche
..........

Module *note readline: bf.

     Useful example of *note atexit: d. to read and write *note
     readline: bf. history files.

* Menu:

* atexit Example::


File: python.info,  Node: atexit Example,  Up: atexit — Exit handlers

5.29.10.1 ‘atexit’ Example
..........................

The following simple example demonstrates how a module can initialize a
counter from a file when it is imported and save the counter’s updated
value automatically when the program terminates without relying on the
application making an explicit call into this module at termination.

     try:
         with open('counterfile') as infile:
             _count = int(infile.read())
     except FileNotFoundError:
         _count = 0

     def incrcounter(n):
         global _count
         _count = _count + n

     def savecounter():
         with open('counterfile', 'w') as outfile:
             outfile.write('%d' % _count)

     import atexit

     atexit.register(savecounter)

Positional and keyword arguments may also be passed to *note register():
a80. to be passed along to the registered function when it is called:

     def goodbye(name, adjective):
         print('Goodbye %s, it was %s to meet you.' % (name, adjective))

     import atexit

     atexit.register(goodbye, 'Donny', 'nice')
     # or:
     atexit.register(goodbye, adjective='nice', name='Donny')

Usage as a *note decorator: 93b.:

     import atexit

     @atexit.register
     def goodbye():
         print('You are now leaving the Python sector.')

This only works with functions that can be called without arguments.


File: python.info,  Node: traceback — Print or retrieve a stack traceback,  Next: __future__ — Future statement definitions,  Prev: atexit — Exit handlers,  Up: Python Runtime Services

5.29.11 ‘traceback’ — Print or retrieve a stack traceback
---------------------------------------------------------

'Source code:' Lib/traceback.py(1)

__________________________________________________________________

This module provides a standard interface to extract, format and print
stack traces of Python programs.  It is more flexible than the
interpreter’s default traceback display, and therefore makes it possible
to configure certain aspects of the output.  Finally, it contains a
utility for capturing enough information about an exception to print it
later, without the need to save a reference to the actual exception.
Since exceptions can be the roots of large objects graph, this utility
can significantly improve memory management.

The module uses *note traceback objects: cee. — these are objects of
type *note types.TracebackType: cec, which are assigned to the *note
__traceback__: 14ce. field of *note BaseException: 7d8. instances.

Vedi anche
..........

Module *note faulthandler: 5c.

     Used to dump Python tracebacks explicitly, on a fault, after a
     timeout, or on a user signal.

Module *note pdb: aa.

     Interactive source code debugger for Python programs.

The module’s API can be divided into two parts:

   * Module-level functions offering basic functionality, which are
     useful for interactive inspection of exceptions and tracebacks.

   * *note TracebackException: 563. class and its helper classes *note
     StackSummary: 1085. and *note FrameSummary: 1086.  These offer both
     more flexibility in the output generated and the ability to store
     the information necessary for later formatting without holding
     references to actual exception and traceback objects.

Added in version 3.13: Output is colorized by default and can be *note
controlled using environment variables: 1b7.

* Menu:

* Module-Level Functions: Module-Level Functions<2>.
* TracebackException Objects::
* StackSummary Objects::
* FrameSummary Objects::
* Examples of Using the Module-Level Functions::
* Examples of Using TracebackException::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/traceback.py


File: python.info,  Node: Module-Level Functions<2>,  Next: TracebackException Objects,  Up: traceback — Print or retrieve a stack traceback

5.29.11.1 Module-Level Functions
................................

 -- Funzione: traceback.print_tb (tb, limit=None, file=None)

     Print up to 'limit' stack trace entries from *note traceback
     object: cee. 'tb' (starting from the caller’s frame) if 'limit' is
     positive.  Otherwise, print the last ‘abs(limit)’ entries.  If
     'limit' is omitted or ‘None’, all entries are printed.  If 'file'
     is omitted or ‘None’, the output goes to *note sys.stderr: b35.;
     otherwise it should be an open *note file: 13cb. or *note file-like
     object: 1794. to receive the output.

          Nota: The meaning of the 'limit' parameter is different than
          the meaning of *note sys.tracebacklimit: 192c.  A negative
          'limit' value corresponds to a positive value of
          ‘sys.tracebacklimit’, whereas the behaviour of a positive
          'limit' value cannot be achieved with ‘sys.tracebacklimit’.

     Cambiato nella versione 3.5: Added negative 'limit' support.

 -- Funzione: traceback.print_exception (exc, /[, value, tb],
          limit=None, file=None, chain=True)

     Print exception information and stack trace entries from *note
     traceback object: cee. 'tb' to 'file'.  This differs from *note
     print_tb(): 1087. in the following ways:

        * if 'tb' is not ‘None’, it prints a header ‘Traceback (most
          recent call last):’

        * it prints the exception type and 'value' after the stack trace

        * if 'type(value)' is *note SyntaxError: 18e. and 'value' has
          the appropriate format, it prints the line where the syntax
          error occurred with a caret indicating the approximate
          position of the error.

     Since Python 3.10, instead of passing 'value' and 'tb', an
     exception object can be passed as the first argument.  If 'value'
     and 'tb' are provided, the first argument is ignored in order to
     provide backwards compatibility.

     The optional 'limit' argument has the same meaning as for *note
     print_tb(): 1087.  If 'chain' is true (the default), then chained
     exceptions (the *note __cause__: 14d0. or *note __context__: 14cf.
     attributes of the exception) will be printed as well, like the
     interpreter itself does when printing an unhandled exception.

     Cambiato nella versione 3.5: The 'etype' argument is ignored and
     inferred from the type of 'value'.

     Cambiato nella versione 3.10: The 'etype' parameter has been
     renamed to 'exc' and is now positional-only.

 -- Funzione: traceback.print_exc (limit=None, file=None, chain=True)

     This is a shorthand for ‘print_exception(sys.exception(),
     limit=limit, file=file, chain=chain)’.

 -- Funzione: traceback.print_last (limit=None, file=None, chain=True)

     This is a shorthand for ‘print_exception(sys.last_exc, limit=limit,
     file=file, chain=chain)’.  In general it will work only after an
     exception has reached an interactive prompt (see *note
     sys.last_exc: 6e6.).

 -- Funzione: traceback.print_stack (f=None, limit=None, file=None)

     Print up to 'limit' stack trace entries (starting from the
     invocation point) if 'limit' is positive.  Otherwise, print the
     last ‘abs(limit)’ entries.  If 'limit' is omitted or ‘None’, all
     entries are printed.  The optional 'f' argument can be used to
     specify an alternate *note stack frame: 8f0. to start.  The
     optional 'file' argument has the same meaning as for *note
     print_tb(): 1087.

     Cambiato nella versione 3.5: Added negative 'limit' support.

 -- Funzione: traceback.extract_tb (tb, limit=None)

     Return a *note StackSummary: 1085. object representing a list of
     «pre-processed» stack trace entries extracted from the *note
     traceback object: cee. 'tb'.  It is useful for alternate formatting
     of stack traces.  The optional 'limit' argument has the same
     meaning as for *note print_tb(): 1087.  A «pre-processed» stack
     trace entry is a *note FrameSummary: 1086. object containing
     attributes *note filename: 49c0, *note lineno: 49c1, *note name:
     49c2, and *note line: 49c3. representing the information that is
     usually printed for a stack trace.

 -- Funzione: traceback.extract_stack (f=None, limit=None)

     Extract the raw traceback from the current *note stack frame: 8f0.
     The return value has the same format as for *note extract_tb():
     49bf.  The optional 'f' and 'limit' arguments have the same meaning
     as for *note print_stack(): 1088.

 -- Funzione: traceback.print_list (extracted_list, file=None)

     Print the list of tuples as returned by *note extract_tb(): 49bf.
     or *note extract_stack(): 49c4. as a formatted stack trace to the
     given file.  If 'file' is ‘None’, the output is written to *note
     sys.stderr: b35.

 -- Funzione: traceback.format_list (extracted_list)

     Given a list of tuples or *note FrameSummary: 1086. objects as
     returned by *note extract_tb(): 49bf. or *note extract_stack():
     49c4, return a list of strings ready for printing.  Each string in
     the resulting list corresponds to the item with the same index in
     the argument list.  Each string ends in a newline; the strings may
     contain internal newlines as well, for those items whose source
     text line is not ‘None’.

 -- Funzione: traceback.format_exception_only (exc, /[, value], *,
          show_group=False)

     Format the exception part of a traceback using an exception value
     such as given by *note sys.last_value: 6e8.  The return value is a
     list of strings, each ending in a newline.  The list contains the
     exception’s message, which is normally a single string; however,
     for *note SyntaxError: 18e. exceptions, it contains several lines
     that (when printed) display detailed information about where the
     syntax error occurred.  Following the message, the list contains
     the exception’s *note notes: 26c7.

     Since Python 3.10, instead of passing 'value', an exception object
     can be passed as the first argument.  If 'value' is provided, the
     first argument is ignored in order to provide backwards
     compatibility.

     When 'show_group' is ‘True’, and the exception is an instance of
     *note BaseExceptionGroup: 566, the nested exceptions are included
     as well, recursively, with indentation relative to their nesting
     depth.

     Cambiato nella versione 3.10: The 'etype' parameter has been
     renamed to 'exc' and is now positional-only.

     Cambiato nella versione 3.11: The returned list now includes any
     *note notes: 26c7. attached to the exception.

     Cambiato nella versione 3.13: 'show_group' parameter was added.

 -- Funzione: traceback.format_exception (exc, /[, value, tb],
          limit=None, chain=True)

     Format a stack trace and the exception information.  The arguments
     have the same meaning as the corresponding arguments to *note
     print_exception(): a51.  The return value is a list of strings,
     each ending in a newline and some containing internal newlines.
     When these lines are concatenated and printed, exactly the same
     text is printed as does *note print_exception(): a51.

     Cambiato nella versione 3.5: The 'etype' argument is ignored and
     inferred from the type of 'value'.

     Cambiato nella versione 3.10: This function’s behavior and
     signature were modified to match *note print_exception(): a51.

 -- Funzione: traceback.format_exc (limit=None, chain=True)

     This is like ‘print_exc(limit)’ but returns a string instead of
     printing to a file.

 -- Funzione: traceback.format_tb (tb, limit=None)

     A shorthand for ‘format_list(extract_tb(tb, limit))’.

 -- Funzione: traceback.format_stack (f=None, limit=None)

     A shorthand for ‘format_list(extract_stack(f, limit))’.

 -- Funzione: traceback.clear_frames (tb)

     Clears the local variables of all the stack frames in a *note
     traceback: cee. 'tb' by calling the *note clear(): 585. method of
     each *note frame object: 8f0.

     Added in version 3.4.

 -- Funzione: traceback.walk_stack (f)

     Walk a stack following *note f.f_back: 990. from the given frame,
     yielding the frame and line number for each frame.  If 'f' is
     ‘None’, the current stack is used.  This helper is used with *note
     StackSummary.extract(): 49c8.

     Added in version 3.5.

     Cambiato nella versione 3.14: This function previously returned a
     generator that would walk the stack when first iterated over.  The
     generator returned now is the state of the stack when ‘walk_stack’
     is called.

 -- Funzione: traceback.walk_tb (tb)

     Walk a traceback following *note tb_next: ced. yielding the frame
     and line number for each frame.  This helper is used with *note
     StackSummary.extract(): 49c8.

     Added in version 3.5.


File: python.info,  Node: TracebackException Objects,  Next: StackSummary Objects,  Prev: Module-Level Functions<2>,  Up: traceback — Print or retrieve a stack traceback

5.29.11.2 ‘TracebackException’ Objects
......................................

Added in version 3.5.

‘TracebackException’ objects are created from actual exceptions to
capture data for later printing.  They offer a more lightweight method
of storing this information by avoiding holding references to *note
traceback: cee. and *note frame: 8f0. objects.  In addition, they expose
more options to configure the output compared to the module-level
functions described above.

 -- Classe: traceback.TracebackException (exc_type, exc_value,
          exc_traceback, *, limit=None, lookup_lines=True,
          capture_locals=False, compact=False, max_group_width=15,
          max_group_depth=10)

     Capture an exception for later rendering.  The meaning of 'limit',
     'lookup_lines' and 'capture_locals' are as for the *note
     StackSummary: 1085. class.

     If 'compact' is true, only data that is required by
     ‘TracebackException’’s *note format(): 199. method is saved in the
     class attributes.  In particular, the *note __context__: 49ca.
     field is calculated only if *note __cause__: 49cb. is ‘None’ and
     *note __suppress_context__: 49cc. is false.

     Note that when locals are captured, they are also shown in the
     traceback.

     'max_group_width' and 'max_group_depth' control the formatting of
     exception groups (see *note BaseExceptionGroup: 566.).  The depth
     refers to the nesting level of the group, and the width refers to
     the size of a single exception group’s exceptions array.  The
     formatted output is truncated when either limit is exceeded.

     Cambiato nella versione 3.10: Added the 'compact' parameter.

     Cambiato nella versione 3.11: Added the 'max_group_width' and
     'max_group_depth' parameters.

      -- Attributo: __cause__

          A ‘TracebackException’ of the original *note __cause__: 14d0.

      -- Attributo: __context__

          A ‘TracebackException’ of the original *note __context__:
          14cf.

      -- Attributo: exceptions

          If ‘self’ represents an *note ExceptionGroup: 4d3, this field
          holds a list of ‘TracebackException’ instances representing
          the nested exceptions.  Otherwise it is ‘None’.

          Added in version 3.11.

      -- Attributo: __suppress_context__

          The *note __suppress_context__: 24f0. value from the original
          exception.

      -- Attributo: __notes__

          The *note __notes__: 26c7. value from the original exception,
          or ‘None’ if the exception does not have any notes.  If it is
          not ‘None’ is it formatted in the traceback after the
          exception string.

          Added in version 3.11.

      -- Attributo: stack

          A *note StackSummary: 1085. representing the traceback.

      -- Attributo: exc_type

          The class of the original traceback.

          Deprecato dalla versione 3.13.

      -- Attributo: exc_type_str

          String display of the class of the original exception.

          Added in version 3.13.

      -- Attributo: filename

          For syntax errors - the file name where the error occurred.

      -- Attributo: lineno

          For syntax errors - the line number where the error occurred.

      -- Attributo: end_lineno

          For syntax errors - the end line number where the error
          occurred.  Can be ‘None’ if not present.

          Added in version 3.10.

      -- Attributo: text

          For syntax errors - the text where the error occurred.

      -- Attributo: offset

          For syntax errors - the offset into the text where the error
          occurred.

      -- Attributo: end_offset

          For syntax errors - the end offset into the text where the
          error occurred.  Can be ‘None’ if not present.

          Added in version 3.10.

      -- Attributo: msg

          For syntax errors - the compiler error message.

      -- Metodo: classmethod from_exception (exc, *, limit=None,
               lookup_lines=True, capture_locals=False)

          Capture an exception for later rendering.  'limit',
          'lookup_lines' and 'capture_locals' are as for the *note
          StackSummary: 1085. class.

          Note that when locals are captured, they are also shown in the
          traceback.

      -- Metodo: print (*, file=None, chain=True)

          Print to 'file' (default ‘sys.stderr’) the exception
          information returned by *note format(): 199.

          Added in version 3.11.

      -- Metodo: format (*, chain=True)

          Format the exception.

          If 'chain' is not ‘True’, *note __cause__: 49cb. and *note
          __context__: 49ca. will not be formatted.

          The return value is a generator of strings, each ending in a
          newline and some containing internal newlines.  *note
          print_exception(): a51. is a wrapper around this method which
          just prints the lines to a file.

      -- Metodo: format_exception_only (*, show_group=False)

          Format the exception part of the traceback.

          The return value is a generator of strings, each ending in a
          newline.

          When 'show_group' is ‘False’, the generator emits the
          exception’s message followed by its notes (if it has any).
          The exception message is normally a single string; however,
          for *note SyntaxError: 18e. exceptions, it consists of several
          lines that (when printed) display detailed information about
          where the syntax error occurred.

          When 'show_group' is ‘True’, and the exception is an instance
          of *note BaseExceptionGroup: 566, the nested exceptions are
          included as well, recursively, with indentation relative to
          their nesting depth.

          Cambiato nella versione 3.11: The exception’s *note notes:
          26c7. are now included in the output.

          Cambiato nella versione 3.13: Added the 'show_group'
          parameter.


File: python.info,  Node: StackSummary Objects,  Next: FrameSummary Objects,  Prev: TracebackException Objects,  Up: traceback — Print or retrieve a stack traceback

5.29.11.3 ‘StackSummary’ Objects
................................

Added in version 3.5.

‘StackSummary’ objects represent a call stack ready for formatting.

 -- Classe: traceback.StackSummary

      -- Metodo: classmethod extract (frame_gen, *, limit=None,
               lookup_lines=True, capture_locals=False)

          Construct a ‘StackSummary’ object from a frame generator (such
          as is returned by *note walk_stack(): 1083. or *note
          walk_tb(): 1084.).

          If 'limit' is supplied, only this many frames are taken from
          'frame_gen'.  If 'lookup_lines' is ‘False’, the returned *note
          FrameSummary: 1086. objects will not have read their lines in
          yet, making the cost of creating the ‘StackSummary’ cheaper
          (which may be valuable if it may not actually get formatted).
          If 'capture_locals' is ‘True’ the local variables in each
          ‘FrameSummary’ are captured as object representations.

          Cambiato nella versione 3.12: Exceptions raised from *note
          repr(): 1c1. on a local variable (when 'capture_locals' is
          ‘True’) are no longer propagated to the caller.

      -- Metodo: classmethod from_list (a_list)

          Construct a ‘StackSummary’ object from a supplied list of
          *note FrameSummary: 1086. objects or old-style list of tuples.
          Each tuple should be a 4-tuple with 'filename', 'lineno',
          'name', 'line' as the elements.

      -- Metodo: format ()

          Returns a list of strings ready for printing.  Each string in
          the resulting list corresponds to a single *note frame: 8f0.
          from the stack.  Each string ends in a newline; the strings
          may contain internal newlines as well, for those items with
          source text lines.

          For long sequences of the same frame and line, the first few
          repetitions are shown, followed by a summary line stating the
          exact number of further repetitions.

          Cambiato nella versione 3.6: Long sequences of repeated frames
          are now abbreviated.

      -- Metodo: format_frame_summary (frame_summary)

          Returns a string for printing one of the *note frames: 8f0.
          involved in the stack.  This method is called for each *note
          FrameSummary: 1086. object to be printed by *note
          StackSummary.format(): 49db.  If it returns ‘None’, the frame
          is omitted from the output.

          Added in version 3.11.


File: python.info,  Node: FrameSummary Objects,  Next: Examples of Using the Module-Level Functions,  Prev: StackSummary Objects,  Up: traceback — Print or retrieve a stack traceback

5.29.11.4 ‘FrameSummary’ Objects
................................

Added in version 3.5.

A ‘FrameSummary’ object represents a single *note frame: 8f0. in a *note
traceback: cee.

 -- Classe: traceback.FrameSummary (filename, lineno, name, *,
          lookup_line=True, locals=None, line=None, end_lineno=None,
          colno=None, end_colno=None)

     Represents a single *note frame: 8f0. in the *note traceback: cee.
     or stack that is being formatted or printed.  It may optionally
     have a stringified version of the frame’s locals included in it.
     If 'lookup_line' is ‘False’, the source code is not looked up until
     the ‘FrameSummary’ has the *note line: 49c3. attribute accessed
     (which also happens when casting it to a *note tuple: 614.).  *note
     line: 49c3. may be directly provided, and will prevent line lookups
     happening at all.  'locals' is an optional local variable mapping,
     and if supplied the variable representations are stored in the
     summary for later display.

     ‘FrameSummary’ instances have the following attributes:

      -- Attributo: filename

          The filename of the source code for this frame.  Equivalent to
          accessing *note f.f_code.co_filename: 1575. on a *note frame
          object: 8f0. 'f'.

      -- Attributo: lineno

          The line number of the source code for this frame.

      -- Attributo: name

          Equivalent to accessing *note f.f_code.co_name: 236b. on a
          *note frame object: 8f0. 'f'.

      -- Attributo: line

          A string representing the source code for this frame, with
          leading and trailing whitespace stripped.  If the source is
          not available, it is ‘None’.

      -- Attributo: end_lineno

          The last line number of the source code for this frame.  By
          default, it is set to ‘lineno’ and indexation starts from 1.

          Cambiato nella versione 3.13: The default value changed from
          ‘None’ to ‘lineno’.

      -- Attributo: colno

          The column number of the source code for this frame.  By
          default, it is ‘None’ and indexation starts from 0.

      -- Attributo: end_colno

          The last column number of the source code for this frame.  By
          default, it is ‘None’ and indexation starts from 0.


File: python.info,  Node: Examples of Using the Module-Level Functions,  Next: Examples of Using TracebackException,  Prev: FrameSummary Objects,  Up: traceback — Print or retrieve a stack traceback

5.29.11.5 Examples of Using the Module-Level Functions
......................................................

This simple example implements a basic read-eval-print loop, similar to
(but less useful than) the standard Python interactive interpreter loop.
For a more complete implementation of the interpreter loop, refer to the
*note code: 1b. module.

     import sys, traceback

     def run_user_code(envdir):
         source = input(">>> ")
         try:
             exec(source, envdir)
         except Exception:
             print("Exception in user code:")
             print("-"*60)
             traceback.print_exc(file=sys.stdout)
             print("-"*60)

     envdir = {}
     while True:
         run_user_code(envdir)

The following example demonstrates the different ways to print and
format the exception and traceback:

     import sys, traceback

     def lumberjack():
         bright_side_of_life()

     def bright_side_of_life():
         return tuple()[0]

     try:
         lumberjack()
     except IndexError as exc:
         print("*** print_tb:")
         traceback.print_tb(exc.__traceback__, limit=1, file=sys.stdout)
         print("*** print_exception:")
         traceback.print_exception(exc, limit=2, file=sys.stdout)
         print("*** print_exc:")
         traceback.print_exc(limit=2, file=sys.stdout)
         print("*** format_exc, first and last line:")
         formatted_lines = traceback.format_exc().splitlines()
         print(formatted_lines[0])
         print(formatted_lines[-1])
         print("*** format_exception:")
         print(repr(traceback.format_exception(exc)))
         print("*** extract_tb:")
         print(repr(traceback.extract_tb(exc.__traceback__)))
         print("*** format_tb:")
         print(repr(traceback.format_tb(exc.__traceback__)))
         print("*** tb_lineno:", exc.__traceback__.tb_lineno)

The output for the example would look similar to this:

     *** print_tb:
       File "<doctest...>", line 10, in <module>
         lumberjack()
         ~~~~~~~~~~^^
     *** print_exception:
     Traceback (most recent call last):
       File "<doctest...>", line 10, in <module>
         lumberjack()
         ~~~~~~~~~~^^
       File "<doctest...>", line 4, in lumberjack
         bright_side_of_life()
         ~~~~~~~~~~~~~~~~~~~^^
     IndexError: tuple index out of range
     *** print_exc:
     Traceback (most recent call last):
       File "<doctest...>", line 10, in <module>
         lumberjack()
         ~~~~~~~~~~^^
       File "<doctest...>", line 4, in lumberjack
         bright_side_of_life()
         ~~~~~~~~~~~~~~~~~~~^^
     IndexError: tuple index out of range
     *** format_exc, first and last line:
     Traceback (most recent call last):
     IndexError: tuple index out of range
     *** format_exception:
     ['Traceback (most recent call last):\n',
      '  File "<doctest default[0]>", line 10, in <module>\n    lumberjack()\n    ~~~~~~~~~~^^\n',
      '  File "<doctest default[0]>", line 4, in lumberjack\n    bright_side_of_life()\n    ~~~~~~~~~~~~~~~~~~~^^\n',
      '  File "<doctest default[0]>", line 7, in bright_side_of_life\n    return tuple()[0]\n           ~~~~~~~^^^\n',
      'IndexError: tuple index out of range\n']
     *** extract_tb:
     [<FrameSummary file <doctest...>, line 10 in <module>>,
      <FrameSummary file <doctest...>, line 4 in lumberjack>,
      <FrameSummary file <doctest...>, line 7 in bright_side_of_life>]
     *** format_tb:
     ['  File "<doctest default[0]>", line 10, in <module>\n    lumberjack()\n    ~~~~~~~~~~^^\n',
      '  File "<doctest default[0]>", line 4, in lumberjack\n    bright_side_of_life()\n    ~~~~~~~~~~~~~~~~~~~^^\n',
      '  File "<doctest default[0]>", line 7, in bright_side_of_life\n    return tuple()[0]\n           ~~~~~~~^^^\n']
     *** tb_lineno: 10

The following example shows the different ways to print and format the
stack:

     >>> import traceback
     >>> def another_function():
     ...     lumberstack()
     ...
     >>> def lumberstack():
     ...     traceback.print_stack()
     ...     print(repr(traceback.extract_stack()))
     ...     print(repr(traceback.format_stack()))
     ...
     >>> another_function()
       File "<doctest>", line 10, in <module>
         another_function()
       File "<doctest>", line 3, in another_function
         lumberstack()
       File "<doctest>", line 6, in lumberstack
         traceback.print_stack()
     [('<doctest>', 10, '<module>', 'another_function()'),
      ('<doctest>', 3, 'another_function', 'lumberstack()'),
      ('<doctest>', 7, 'lumberstack', 'print(repr(traceback.extract_stack()))')]
     ['  File "<doctest>", line 10, in <module>\n    another_function()\n',
      '  File "<doctest>", line 3, in another_function\n    lumberstack()\n',
      '  File "<doctest>", line 8, in lumberstack\n    print(repr(traceback.format_stack()))\n']

This last example demonstrates the final few formatting functions:

     >>> import traceback
     >>> traceback.format_list([('spam.py', 3, '<module>', 'spam.eggs()'),
     ...                        ('eggs.py', 42, 'eggs', 'return "bacon"')])
     ['  File "spam.py", line 3, in <module>\n    spam.eggs()\n',
      '  File "eggs.py", line 42, in eggs\n    return "bacon"\n']
     >>> an_error = IndexError('tuple index out of range')
     >>> traceback.format_exception_only(an_error)
     ['IndexError: tuple index out of range\n']


File: python.info,  Node: Examples of Using TracebackException,  Prev: Examples of Using the Module-Level Functions,  Up: traceback — Print or retrieve a stack traceback

5.29.11.6 Examples of Using ‘TracebackException’
................................................

With the helper class, we have more options:

     >>> import sys
     >>> from traceback import TracebackException
     >>>
     >>> def lumberjack():
     ...     bright_side_of_life()
     ...
     >>> def bright_side_of_life():
     ...     t = "bright", "side", "of", "life"
     ...     return t[5]
     ...
     >>> try:
     ...     lumberjack()
     ... except IndexError as e:
     ...     exc = e
     ...
     >>> try:
     ...     try:
     ...         lumberjack()
     ...     except:
     ...         1/0
     ... except Exception as e:
     ...     chained_exc = e
     ...
     >>> # limit works as with the module-level functions
     >>> TracebackException.from_exception(exc, limit=-2).print()
     Traceback (most recent call last):
       File "<python-input-1>", line 6, in lumberjack
         bright_side_of_life()
         ~~~~~~~~~~~~~~~~~~~^^
       File "<python-input-1>", line 10, in bright_side_of_life
         return t[5]
                ~^^^
     IndexError: tuple index out of range

     >>> # capture_locals adds local variables in frames
     >>> TracebackException.from_exception(exc, limit=-2, capture_locals=True).print()
     Traceback (most recent call last):
       File "<python-input-1>", line 6, in lumberjack
         bright_side_of_life()
         ~~~~~~~~~~~~~~~~~~~^^
       File "<python-input-1>", line 10, in bright_side_of_life
         return t[5]
                ~^^^
         t = ("bright", "side", "of", "life")
     IndexError: tuple index out of range

     >>> # The *chain* kwarg to print() controls whether chained
     >>> # exceptions are displayed
     >>> TracebackException.from_exception(chained_exc).print()
     Traceback (most recent call last):
       File "<python-input-19>", line 4, in <module>
         lumberjack()
         ~~~~~~~~~~^^
       File "<python-input-8>", line 7, in lumberjack
         bright_side_of_life()
         ~~~~~~~~~~~~~~~~~~~^^
       File "<python-input-8>", line 11, in bright_side_of_life
         return t[5]
                ~^^^
     IndexError: tuple index out of range

     During handling of the above exception, another exception occurred:

     Traceback (most recent call last):
       File "<python-input-19>", line 6, in <module>
         1/0
         ~^~
     ZeroDivisionError: division by zero

     >>> TracebackException.from_exception(chained_exc).print(chain=False)
     Traceback (most recent call last):
       File "<python-input-19>", line 6, in <module>
         1/0
         ~^~
     ZeroDivisionError: division by zero


File: python.info,  Node: __future__ — Future statement definitions,  Next: gc — Garbage Collector interface,  Prev: traceback — Print or retrieve a stack traceback,  Up: Python Runtime Services

5.29.12 ‘__future__’ — Future statement definitions
---------------------------------------------------

'Source code:' Lib/__future__.py(1)

__________________________________________________________________

Imports of the form ‘from __future__ import feature’ are called *note
future statements: 45d.  These are special-cased by the Python compiler
to allow the use of new Python features in modules containing the future
statement before the release in which the feature becomes standard.

While these future statements are given additional special meaning by
the Python compiler, they are still executed like any other import
statement and the *note __future__: 0. exists and is handled by the
import system the same way any other Python module would be.  This
design serves three purposes:

   * To avoid confusing existing tools that analyze import statements
     and expect to find the modules they’re importing.

   * To document when incompatible changes were introduced, and when
     they will be — or were — made mandatory.  This is a form of
     executable documentation, and can be inspected programmatically via
     importing *note __future__: 0. and examining its contents.

   * To ensure that *note future statements: 45d. run under releases
     prior to Python 2.1 at least yield runtime exceptions (the import
     of *note __future__: 0. will fail, because there was no module of
     that name prior to 2.1).

* Menu:

* Module Contents: Module Contents<5>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/__future__.py


File: python.info,  Node: Module Contents<5>,  Up: __future__ — Future statement definitions

5.29.12.1 Module Contents
.........................

No feature description will ever be deleted from *note __future__: 0.
Since its introduction in Python 2.1 the following features have found
their way into the language using this mechanism:

feature                       optional in                   mandatory in                  effect
                                                                                          
------------------------------------------------------------------------------------------------------------------------
                                                                                          
 -- Dati:                     2.1.0b1                       2.2                           PEP 227(1): 'Statically
          __future__.nested_scopes                                                        Nested Scopes'
                                                                                          
                                                                                          
 -- Dati:                     2.2.0a1                       2.3                           PEP 255(2): 'Simple
          __future__.generators                                                           Generators'
                                                                                          
                                                                                          
 -- Dati:                     2.2.0a2                       3.0                           PEP 238(3): 'Changing the
          __future__.division                                                             Division Operator'
                                                                                          
                                                                                          
 -- Dati:                     2.5.0a1                       3.0                           PEP 328(4): 'Imports:
          __future__.absolute_import                                                      Multi-Line and
                                                                                          Absolute/Relative'
                                                                                          
                                                                                          
 -- Dati:                     2.5.0a1                       2.6                           PEP 343(5): 'The “with”
          __future__.with_statement                                                       Statement'
                                                                                          
                                                                                          
 -- Dati:                     2.6.0a2                       3.0                           PEP 3105(6): 'Make print a
          __future__.print_function                                                       function'
                                                                                          
                                                                                          
 -- Dati:                     2.6.0a2                       3.0                           PEP 3112(7): 'Bytes
          __future__.unicode_literals                                                     literals in Python 3000'
                                                                                          
                                                                                          
 -- Dati:                     3.5.0b1                       3.7                           PEP 479(8): 'StopIteration
          __future__.generator_stop                                                       handling inside generators'
                                                                                          
                                                                                          
 -- Dati:                     3.7.0b1                       Never (9)                     PEP 563(10): 'Postponed
          __future__.annotations                                                          evaluation of annotations',
                                                                                          PEP 649(11): 'Deferred
                                                                                          evaluation of annotations
                                                                                          using descriptors'
                                                                                          

 -- Classe: __future__._Feature

     Each statement in ‘__future__.py’ is of the form:

          FeatureName = _Feature(OptionalRelease, MandatoryRelease,
                                 CompilerFlag)

     where, normally, 'OptionalRelease' is less than 'MandatoryRelease',
     and both are 5-tuples of the same form as *note sys.version_info:
     8b0.:

          (PY_MAJOR_VERSION, # the 2 in 2.1.0a3; an int
           PY_MINOR_VERSION, # the 1; an int
           PY_MICRO_VERSION, # the 0; an int
           PY_RELEASE_LEVEL, # "alpha", "beta", "candidate" or "final"; string
           PY_RELEASE_SERIAL # the 3; an int
          )

 -- Metodo: _Feature.getOptionalRelease ()

     'OptionalRelease' records the first release in which the feature
     was accepted.

 -- Metodo: _Feature.getMandatoryRelease ()

     In the case of a 'MandatoryRelease' that has not yet occurred,
     'MandatoryRelease' predicts the release in which the feature will
     become part of the language.

     Else 'MandatoryRelease' records when the feature became part of the
     language; in releases at or after that, modules no longer need a
     future statement to use the feature in question, but may continue
     to use such imports.

     'MandatoryRelease' may also be ‘None’, meaning that a planned
     feature got dropped or that it is not yet decided.

 -- Attributo: _Feature.compiler_flag

     'CompilerFlag' is the (bitfield) flag that should be passed in the
     fourth argument to the built-in function *note compile(): 4b2. to
     enable the feature in dynamically compiled code.  This flag is
     stored in the *note _Feature.compiler_flag: 2379. attribute on
     *note _Feature: 25a4. instances.

Vedi anche
..........

*note Future statements: 45d.

     How the compiler treats future imports.

PEP 236(12) - Back to the __future__

     The original proposal for the __future__ mechanism.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0227/

   (2) https://peps.python.org/pep-0255/

   (3) https://peps.python.org/pep-0238/

   (4) https://peps.python.org/pep-0328/

   (5) https://peps.python.org/pep-0343/

   (6) https://peps.python.org/pep-3105/

   (7) https://peps.python.org/pep-3112/

   (8) https://peps.python.org/pep-0479/

   (9) ‘from __future__ import annotations’ was previously scheduled to
become mandatory in Python 3.10, but the change was delayed and
ultimately canceled.  This feature will eventually be deprecated and
removed.  See PEP 649 (https://peps.python.org/pep-0649/) and PEP 749
(https://peps.python.org/pep-0749/).

   (10) https://peps.python.org/pep-0563/

   (11) https://peps.python.org/pep-0649/

   (12) https://peps.python.org/pep-0236/


File: python.info,  Node: gc — Garbage Collector interface,  Next: inspect — Inspect live objects,  Prev: __future__ — Future statement definitions,  Up: Python Runtime Services

5.29.13 ‘gc’ — Garbage Collector interface
------------------------------------------

__________________________________________________________________

This module provides an interface to the optional garbage collector.  It
provides the ability to disable the collector, tune the collection
frequency, and set debugging options.  It also provides access to
unreachable objects that the collector found but cannot free.  Since the
collector supplements the reference counting already used in Python, you
can disable the collector if you are sure your program does not create
reference cycles.  Automatic collection can be disabled by calling
‘gc.disable()’.  To debug a leaking program call
‘gc.set_debug(gc.DEBUG_LEAK)’.  Notice that this includes
‘gc.DEBUG_SAVEALL’, causing garbage-collected objects to be saved in
gc.garbage for inspection.

The *note gc: 64. module provides the following functions:

 -- Funzione: gc.enable ()

     Enable automatic garbage collection.

 -- Funzione: gc.disable ()

     Disable automatic garbage collection.

 -- Funzione: gc.isenabled ()

     Return ‘True’ if automatic collection is enabled.

 -- Funzione: gc.collect (generation=2)

     Perform a collection.  The optional argument 'generation' may be an
     integer specifying which generation to collect (from 0 to 2).  A
     *note ValueError: 2ec. is raised if the generation number is
     invalid.  The sum of collected objects and uncollectable objects is
     returned.

     Calling ‘gc.collect(0)’ will perform a GC collection on the young
     generation.

     Calling ‘gc.collect(1)’ will perform a GC collection on the young
     generation and an increment of the old generation.

     Calling ‘gc.collect(2)’ or ‘gc.collect()’ performs a full
     collection

     The free lists maintained for a number of built-in types are
     cleared whenever a full collection or collection of the highest
     generation (2) is run.  Not all items in some free lists may be
     freed due to the particular implementation, in particular *note
     float: 196.

     The effect of calling ‘gc.collect()’ while the interpreter is
     already performing a collection is undefined.

     Cambiato nella versione 3.14: ‘generation=1’ performs an increment
     of collection.

 -- Funzione: gc.set_debug (flags)

     Set the garbage collection debugging flags.  Debugging information
     will be written to ‘sys.stderr’.  See below for a list of debugging
     flags which can be combined using bit operations to control
     debugging.

 -- Funzione: gc.get_debug ()

     Return the debugging flags currently set.

 -- Funzione: gc.get_objects (generation=None)

     Returns a list of all objects tracked by the collector, excluding
     the list returned.  If 'generation' is not ‘None’, return only the
     objects as follows:

        * 0: All objects in the young generation

        * 1: No objects, as there is no generation 1 (as of Python 3.14)

        * 2: All objects in the old generation

     Cambiato nella versione 3.8: New 'generation' parameter.

     Cambiato nella versione 3.14: Generation 1 is removed

     Raises an *note auditing event: 1c56. ‘gc.get_objects’ with
     argument ‘generation’.

 -- Funzione: gc.get_stats ()

     Return a list of three per-generation dictionaries containing
     collection statistics since interpreter start.  The number of keys
     may change in the future, but currently each dictionary will
     contain the following items:

        * ‘collections’ is the number of times this generation was
          collected;

        * ‘collected’ is the total number of objects collected inside
          this generation;

        * ‘uncollectable’ is the total number of objects which were
          found to be uncollectable (and were therefore moved to the
          *note garbage: 13c9. list) inside this generation.

     Added in version 3.4.

 -- Funzione: gc.set_threshold (threshold0[, threshold1[, threshold2]])

     Set the garbage collection thresholds (the collection frequency).
     Setting 'threshold0' to zero disables collection.

     The GC classifies objects into two generations depending on whether
     they have survived a collection.  New objects are placed in the
     young generation.  If an object survives a collection it is moved
     into the old generation.

     In order to decide when to run, the collector keeps track of the
     number of object allocations and deallocations since the last
     collection.  When the number of allocations minus the number of
     deallocations exceeds 'threshold0', collection starts.  For each
     collection, all the objects in the young generation and some
     fraction of the old generation is collected.

     In the free-threaded build, the increase in process memory usage is
     also checked before running the collector.  If the memory usage has
     not increased by 10% since the last collection and the net number
     of object allocations has not exceeded 40 times 'threshold0', the
     collection is not run.

     The fraction of the old generation that is collected is 'inversely'
     proportional to 'threshold1'.  The larger 'threshold1' is, the
     slower objects in the old generation are collected.  For the
     default value of 10, 1% of the old generation is scanned during
     each collection.

     'threshold2' is ignored.

     See Garbage collector design(1) for more information.

     Cambiato nella versione 3.14: 'threshold2' is ignored

 -- Funzione: gc.get_count ()

     Return the current collection counts as a tuple of ‘(count0,
     count1, count2)’.

 -- Funzione: gc.get_threshold ()

     Return the current collection thresholds as a tuple of
     ‘(threshold0, threshold1, threshold2)’.

 -- Funzione: gc.get_referrers (*objs)

     Return the list of objects that directly refer to any of objs.
     This function will only locate those containers which support
     garbage collection; extension types which do refer to other objects
     but do not support garbage collection will not be found.

     Note that objects which have already been dereferenced, but which
     live in cycles and have not yet been collected by the garbage
     collector can be listed among the resulting referrers.  To get only
     currently live objects, call *note collect(): 1b3. before calling
     *note get_referrers(): a07.

          Avvertimento: Care must be taken when using objects returned
          by *note get_referrers(): a07. because some of them could
          still be under construction and hence in a temporarily invalid
          state.  Avoid using *note get_referrers(): a07. for any
          purpose other than debugging.

     Raises an *note auditing event: 1c56. ‘gc.get_referrers’ with
     argument ‘objs’.

 -- Funzione: gc.get_referents (*objs)

     Return a list of objects directly referred to by any of the
     arguments.  The referents returned are those objects visited by the
     arguments” C-level *note tp_traverse: 983. methods (if any), and
     may not be all objects actually directly reachable.  *note
     tp_traverse: 983. methods are supported only by objects that
     support garbage collection, and are only required to visit objects
     that may be involved in a cycle.  So, for example, if an integer is
     directly reachable from an argument, that integer object may or may
     not appear in the result list.

     Raises an *note auditing event: 1c56. ‘gc.get_referents’ with
     argument ‘objs’.

 -- Funzione: gc.is_tracked (obj)

     Returns ‘True’ if the object is currently tracked by the garbage
     collector, ‘False’ otherwise.  As a general rule, instances of
     atomic types aren’t tracked and instances of non-atomic types
     (containers, user-defined objects…) are.  However, some
     type-specific optimizations can be present in order to suppress the
     garbage collector footprint of simple instances (e.g.  dicts
     containing only atomic keys and values):

          >>> gc.is_tracked(0)
          False
          >>> gc.is_tracked("a")
          False
          >>> gc.is_tracked([])
          True
          >>> gc.is_tracked({})
          False
          >>> gc.is_tracked({"a": 1})
          True

     Added in version 3.1.

 -- Funzione: gc.is_finalized (obj)

     Returns ‘True’ if the given object has been finalized by the
     garbage collector, ‘False’ otherwise.

          >>> x = None
          >>> class Lazarus:
          ...     def __del__(self):
          ...         global x
          ...         x = self
          ...
          >>> lazarus = Lazarus()
          >>> gc.is_finalized(lazarus)
          False
          >>> del lazarus
          >>> gc.is_finalized(x)
          True

     Added in version 3.9.

 -- Funzione: gc.freeze ()

     Freeze all the objects tracked by the garbage collector; move them
     to a permanent generation and ignore them in all the future
     collections.

     If a process will ‘fork()’ without ‘exec()’, avoiding unnecessary
     copy-on-write in child processes will maximize memory sharing and
     reduce overall memory usage.  This requires both avoiding creation
     of freed «holes» in memory pages in the parent process and ensuring
     that GC collections in child processes won’t touch the ‘gc_refs’
     counter of long-lived objects originating in the parent process.
     To accomplish both, call ‘gc.disable()’ early in the parent
     process, ‘gc.freeze()’ right before ‘fork()’, and ‘gc.enable()’
     early in child processes.

     Added in version 3.7.

 -- Funzione: gc.unfreeze ()

     Unfreeze the objects in the permanent generation, put them back
     into the oldest generation.

     Added in version 3.7.

 -- Funzione: gc.get_freeze_count ()

     Return the number of objects in the permanent generation.

     Added in version 3.7.

The following variables are provided for read-only access (you can
mutate the values but should not rebind them):

 -- Dati: gc.garbage

     A list of objects which the collector found to be unreachable but
     could not be freed (uncollectable objects).  Starting with Python
     3.4, this list should be empty most of the time, except when using
     instances of C extension types with a non-‘NULL’ ‘tp_del’ slot.

     If *note DEBUG_SAVEALL: 49fb. is set, then all unreachable objects
     will be added to this list rather than freed.

     Cambiato nella versione 3.2: If this list is non-empty at *note
     interpreter shutdown: 47a, a *note ResourceWarning: 54d. is
     emitted, which is silent by default.  If *note DEBUG_UNCOLLECTABLE:
     13ca. is set, in addition all uncollectable objects are printed.

     Cambiato nella versione 3.4: Following PEP 442(2), objects with a
     *note __del__(): 11ff. method don’t end up in *note gc.garbage:
     13c9. anymore.

 -- Dati: gc.callbacks

     A list of callbacks that will be invoked by the garbage collector
     before and after collection.  The callbacks will be called with two
     arguments, 'phase' and 'info'.

     'phase' can be one of two values:

          «start»: The garbage collection is about to start.

          «stop»: The garbage collection has finished.

     'info' is a dict providing more information for the callback.  The
     following keys are currently defined:

          «generation»: The oldest generation being collected.

          «collected»: When 'phase' is «stop», the number of objects
          successfully collected.

          «uncollectable»: When 'phase' is «stop», the number of objects
          that could not be collected and were put in *note garbage:
          13c9.

     Applications can add their own callbacks to this list.  The primary
     use cases are:

          Gathering statistics about garbage collection, such as how
          often various generations are collected, and how long the
          collection takes.

          Allowing applications to identify and clear their own
          uncollectable types when they appear in *note garbage: 13c9.

     Added in version 3.3.

The following constants are provided for use with *note set_debug():
49f9.:

 -- Dati: gc.DEBUG_STATS

     Print statistics during collection.  This information can be useful
     when tuning the collection frequency.

 -- Dati: gc.DEBUG_COLLECTABLE

     Print information on collectable objects found.

 -- Dati: gc.DEBUG_UNCOLLECTABLE

     Print information of uncollectable objects found (objects which are
     not reachable but cannot be freed by the collector).  These objects
     will be added to the ‘garbage’ list.

     Cambiato nella versione 3.2: Also print the contents of the *note
     garbage: 13c9. list at *note interpreter shutdown: 47a, if it isn’t
     empty.

 -- Dati: gc.DEBUG_SAVEALL

     When set, all unreachable objects found will be appended to
     'garbage' rather than being freed.  This can be useful for
     debugging a leaking program.

 -- Dati: gc.DEBUG_LEAK

     The debugging flags necessary for the collector to print
     information about a leaking program (equal to ‘DEBUG_COLLECTABLE |
     DEBUG_UNCOLLECTABLE | DEBUG_SAVEALL’).

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/blob/3.14/InternalDocs/garbage_collector.md

   (2) https://peps.python.org/pep-0442/


File: python.info,  Node: inspect — Inspect live objects,  Next: annotationlib — Functionality for introspecting annotations,  Prev: gc — Garbage Collector interface,  Up: Python Runtime Services

5.29.14 ‘inspect’ — Inspect live objects
----------------------------------------

'Source code:' Lib/inspect.py(1)

__________________________________________________________________

The *note inspect: 82. module provides several useful functions to help
get information about live objects such as modules, classes, methods,
functions, tracebacks, frame objects, and code objects.  For example, it
can help you examine the contents of a class, retrieve the source code
of a method, extract and format the argument list for a function, or get
all the information you need to display a detailed traceback.

There are four main kinds of services provided by this module: type
checking, getting source code, inspecting classes and functions, and
examining the interpreter stack.

* Menu:

* Types and members::
* Retrieving source code::
* Introspecting callables with the Signature object::
* Classes and functions: Classes and functions<2>.
* The interpreter stack::
* Fetching attributes statically::
* Current State of Generators, Coroutines, and Asynchronous Generators: Current State of Generators Coroutines and Asynchronous Generators.
* Code Objects Bit Flags::
* Buffer flags::
* Command-line interface: Command-line interface<10>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/inspect.py


File: python.info,  Node: Types and members,  Next: Retrieving source code,  Up: inspect — Inspect live objects

5.29.14.1 Types and members
...........................

The *note getmembers(): 1bd9. function retrieves the members of an
object such as a class or module.  The functions whose names begin with
«is» are mainly provided as convenient choices for the second argument
to *note getmembers(): 1bd9.  They also help you determine when you can
expect to find the following special attributes (see *note
Import-related attributes on module objects: 2348. for module
attributes):

Type                  Attribute               Description
                                              
------------------------------------------------------------------------------
                                              
class                 __doc__                 documentation string
                                              
                                              
                      __name__                name with which this class
                                              was defined
                                              
                                              
                      __qualname__            qualified name
                                              
                                              
                      __module__              name of module in which this
                                              class was defined
                                              
                                              
                      __type_params__         A tuple containing the
                                              *note type parameters: 5ad.
                                              of a generic class
                                              
                                              
method                __doc__                 documentation string
                                              
                                              
                      __name__                name with which this method
                                              was defined
                                              
                                              
                      __qualname__            qualified name
                                              
                                              
                      __func__                function object containing
                                              implementation of method
                                              
                                              
                      __self__                instance to which this method
                                              is bound, or ‘None’
                                              
                                              
                      __module__              name of module in which this
                                              method was defined
                                              
                                              
function              __doc__                 documentation string
                                              
                                              
                      __name__                name with which this function
                                              was defined
                                              
                                              
                      __qualname__            qualified name
                                              
                                              
                      __code__                code object containing
                                              compiled function
                                              *note bytecode: 4ab.
                                              
                                              
                      __defaults__            tuple of any default values
                                              for positional or keyword
                                              parameters
                                              
                                              
                      __kwdefaults__          mapping of any default values
                                              for keyword-only parameters
                                              
                                              
                      __globals__             global namespace in which
                                              this function was defined
                                              
                                              
                      __builtins__            builtins namespace
                                              
                                              
                      __annotations__         mapping of parameters names
                                              to annotations; ‘"return"’
                                              key is reserved for return
                                              annotations.
                                              
                                              
                      __type_params__         A tuple containing the
                                              *note type parameters: 5ad.
                                              of a generic function
                                              
                                              
                      __module__              name of module in which this
                                              function was defined
                                              
                                              
traceback             tb_frame                frame object at this level
                                              
                                              
                      tb_lasti                index of last attempted
                                              instruction in bytecode
                                              
                                              
                      tb_lineno               current line number in Python
                                              source code
                                              
                                              
                      tb_next                 next inner traceback object
                                              (called by this level)
                                              
                                              
frame                 f_back                  next outer frame object (this
                                              frame’s caller)
                                              
                                              
                      f_builtins              builtins namespace seen by
                                              this frame
                                              
                                              
                      f_code                  code object being executed in
                                              this frame
                                              
                                              
                      f_globals               global namespace seen by this
                                              frame
                                              
                                              
                      f_lasti                 index of last attempted
                                              instruction in bytecode
                                              
                                              
                      f_lineno                current line number in Python
                                              source code
                                              
                                              
                      f_locals                local namespace seen by this
                                              frame
                                              
                                              
                      f_generator             returns the generator or
                                              coroutine object that owns
                                              this frame, or ‘None’ if the
                                              frame is of a regular
                                              function
                                              
                                              
                      f_trace                 tracing function for this
                                              frame, or ‘None’
                                              
                                              
                      f_trace_lines           indicate whether a tracing
                                              event is triggered for each
                                              source source line
                                              
                                              
                      f_trace_opcodes         indicate whether per-opcode
                                              events are requested
                                              
                                              
                      clear()                 used to clear all references
                                              to local variables
                                              
                                              
code                  co_argcount             number of arguments (not
                                              including keyword only
                                              arguments, * or ** args)
                                              
                                              
                      co_code                 string of raw compiled
                                              bytecode
                                              
                                              
                      co_cellvars             tuple of names of cell
                                              variables (referenced by
                                              containing scopes)
                                              
                                              
                      co_consts               tuple of constants used in
                                              the bytecode
                                              
                                              
                      co_filename             name of file in which this
                                              code object was created
                                              
                                              
                      co_firstlineno          number of first line in
                                              Python source code
                                              
                                              
                      co_flags                bitmap of ‘CO_*’ flags, read
                                              more *note here: 2378.
                                              
                                              
                      co_lnotab               encoded mapping of line
                                              numbers to bytecode indices
                                              
                                              
                      co_freevars             tuple of names of free
                                              variables (referenced via a
                                              function’s closure)
                                              
                                              
                      co_posonlyargcount      number of positional only
                                              arguments
                                              
                                              
                      co_kwonlyargcount       number of keyword only
                                              arguments (not including **
                                              arg)
                                              
                                              
                      co_name                 name with which this code
                                              object was defined
                                              
                                              
                      co_qualname             fully qualified name with
                                              which this code object was
                                              defined
                                              
                                              
                      co_names                tuple of names other than
                                              arguments and function locals
                                              
                                              
                      co_nlocals              number of local variables
                                              
                                              
                      co_stacksize            virtual machine stack space
                                              required
                                              
                                              
                      co_varnames             tuple of names of arguments
                                              and local variables
                                              
                                              
                      co_lines()              returns an iterator that
                                              yields successive bytecode
                                              ranges
                                              
                                              
                      co_positions()          returns an iterator of source
                                              code positions for each
                                              bytecode instruction
                                              
                                              
                      replace()               returns a copy of the code
                                              object with new values
                                              
                                              
generator             __name__                name
                                              
                                              
                      __qualname__            qualified name
                                              
                                              
                      gi_frame                frame
                                              
                                              
                      gi_running              is the generator running?
                                              
                                              
                      gi_suspended            is the generator suspended?
                                              
                                              
                      gi_code                 code
                                              
                                              
                      gi_yieldfrom            object being iterated by
                                              ‘yield from’, or ‘None’
                                              
                                              
async generator       __name__                name
                                              
                                              
                      __qualname__            qualified name
                                              
                                              
                      ag_await                object being awaited on, or
                                              ‘None’
                                              
                                              
                      ag_frame                frame
                                              
                                              
                      ag_running              is the generator running?
                                              
                                              
                      ag_suspended            is the generator suspended?
                                              
                                              
                      ag_code                 code
                                              
                                              
coroutine             __name__                name
                                              
                                              
                      __qualname__            qualified name
                                              
                                              
                      cr_await                object being awaited on, or
                                              ‘None’
                                              
                                              
                      cr_frame                frame
                                              
                                              
                      cr_running              is the coroutine running?
                                              
                                              
                      cr_suspended            is the coroutine suspended?
                                              
                                              
                      cr_code                 code
                                              
                                              
                      cr_origin               where coroutine was created,
                                              or ‘None’.  See
                                              *note sys.set_coroutine_origin_tracking_depth(): d87.
                                              
                                              
builtin               __doc__                 documentation string
                                              
                                              
                      __name__                original name of this
                                              function or method
                                              
                                              
                      __qualname__            qualified name
                                              
                                              
                      __self__                instance to which a method is
                                              bound, or ‘None’
                                              

Cambiato nella versione 3.5: Add ‘__qualname__’ and ‘gi_yieldfrom’
attributes to generators.

The ‘__name__’ attribute of generators is now set from the function
name, instead of the code name, and it can now be modified.

Cambiato nella versione 3.7: Add ‘cr_origin’ attribute to coroutines.

Cambiato nella versione 3.10: Add ‘__builtins__’ attribute to functions.

Cambiato nella versione 3.11: Add ‘gi_suspended’ attribute to
generators.

Cambiato nella versione 3.11: Add ‘cr_suspended’ attribute to
coroutines.

Cambiato nella versione 3.12: Add ‘ag_suspended’ attribute to async
generators.

Cambiato nella versione 3.14: Add ‘f_generator’ attribute to frames.

 -- Funzione: inspect.getmembers (object[, predicate])

     Return all the members of an object in a list of ‘(name, value)’
     pairs sorted by name.  If the optional 'predicate' argument—which
     will be called with the ‘value’ object of each member—is supplied,
     only members for which the predicate returns a true value are
     included.

          Nota: *note getmembers(): 1bd9. will only return class
          attributes defined in the metaclass when the argument is a
          class and those attributes have been listed in the metaclass”
          custom *note __dir__(): 17ca.

 -- Funzione: inspect.getmembers_static (object[, predicate])

     Return all the members of an object in a list of ‘(name, value)’
     pairs sorted by name without triggering dynamic lookup via the
     descriptor protocol, __getattr__ or __getattribute__.  Optionally,
     only return members that satisfy a given predicate.

          Nota: *note getmembers_static(): 85a. may not be able to
          retrieve all members that getmembers can fetch (like
          dynamically created attributes) and may find members that
          getmembers can’t (like descriptors that raise AttributeError).
          It can also return descriptor objects instead of instance
          members in some cases.

     Added in version 3.11.

 -- Funzione: inspect.getmodulename (path)

     Return the name of the module named by the file 'path', without
     including the names of enclosing packages.  The file extension is
     checked against all of the entries in *note
     importlib.machinery.all_suffixes(): 4a03.  If it matches, the final
     path component is returned with the extension removed.  Otherwise,
     ‘None’ is returned.

     Note that this function 'only' returns a meaningful name for actual
     Python modules - paths that potentially refer to Python packages
     will still return ‘None’.

     Cambiato nella versione 3.3: The function is based directly on
     *note importlib: 7b.

 -- Funzione: inspect.ismodule (object)

     Return ‘True’ if the object is a module.

 -- Funzione: inspect.isclass (object)

     Return ‘True’ if the object is a class, whether built-in or created
     in Python code.

 -- Funzione: inspect.ismethod (object)

     Return ‘True’ if the object is a bound method written in Python.

 -- Funzione: inspect.ispackage (object)

     Return ‘True’ if the object is a *note package: 233.

     Added in version 3.14.

 -- Funzione: inspect.isfunction (object)

     Return ‘True’ if the object is a Python function, which includes
     functions created by a *note lambda: 2b99. expression.

 -- Funzione: inspect.isgeneratorfunction (object)

     Return ‘True’ if the object is a Python generator function.

     Cambiato nella versione 3.8: Functions wrapped in *note
     functools.partial(): 217. now return ‘True’ if the wrapped function
     is a Python generator function.

     Cambiato nella versione 3.13: Functions wrapped in *note
     functools.partialmethod(): 218. now return ‘True’ if the wrapped
     function is a Python generator function.

 -- Funzione: inspect.isgenerator (object)

     Return ‘True’ if the object is a generator.

 -- Funzione: inspect.iscoroutinefunction (object)

     Return ‘True’ if the object is a *note coroutine function: f75. (a
     function defined with an *note async def: 7ee. syntax), a *note
     functools.partial(): 217. wrapping a *note coroutine function: f75,
     or a sync function marked with *note markcoroutinefunction(): 6b9.

     Added in version 3.5.

     Cambiato nella versione 3.8: Functions wrapped in *note
     functools.partial(): 217. now return ‘True’ if the wrapped function
     is a *note coroutine function: f75.

     Cambiato nella versione 3.12: Sync functions marked with *note
     markcoroutinefunction(): 6b9. now return ‘True’.

     Cambiato nella versione 3.13: Functions wrapped in *note
     functools.partialmethod(): 218. now return ‘True’ if the wrapped
     function is a *note coroutine function: f75.

 -- Funzione: inspect.markcoroutinefunction (func)

     Decorator to mark a callable as a *note coroutine function: f75. if
     it would not otherwise be detected by *note iscoroutinefunction():
     30d.

     This may be of use for sync functions that return a *note
     coroutine: 6ba, if the function is passed to an API that requires
     *note iscoroutinefunction(): 30d.

     When possible, using an *note async def: 7ee. function is
     preferred.  Also acceptable is calling the function and testing the
     return with *note iscoroutine(): 1019.

     Added in version 3.12.

 -- Funzione: inspect.iscoroutine (object)

     Return ‘True’ if the object is a *note coroutine: 6ba. created by
     an *note async def: 7ee. function.

     Added in version 3.5.

 -- Funzione: inspect.isawaitable (object)

     Return ‘True’ if the object can be used in *note await: 18d.
     expression.

     Can also be used to distinguish generator-based coroutines from
     regular generators:

          import types

          def gen():
              yield
          @types.coroutine
          def gen_coro():
              yield

          assert not isawaitable(gen())
          assert isawaitable(gen_coro())

     Added in version 3.5.

 -- Funzione: inspect.isasyncgenfunction (object)

     Return ‘True’ if the object is an *note asynchronous generator:
     2476. function, for example:

          >>> async def agen():
          ...     yield 1
          ...
          >>> inspect.isasyncgenfunction(agen)
          True

     Added in version 3.6.

     Cambiato nella versione 3.8: Functions wrapped in *note
     functools.partial(): 217. now return ‘True’ if the wrapped function
     is an *note asynchronous generator: 2476. function.

     Cambiato nella versione 3.13: Functions wrapped in *note
     functools.partialmethod(): 218. now return ‘True’ if the wrapped
     function is a *note asynchronous generator: 2476. function.

 -- Funzione: inspect.isasyncgen (object)

     Return ‘True’ if the object is an *note asynchronous generator
     iterator: 4900. created by an *note asynchronous generator: 2476.
     function.

     Added in version 3.6.

 -- Funzione: inspect.istraceback (object)

     Return ‘True’ if the object is a traceback.

 -- Funzione: inspect.isframe (object)

     Return ‘True’ if the object is a frame.

 -- Funzione: inspect.iscode (object)

     Return ‘True’ if the object is a code.

 -- Funzione: inspect.isbuiltin (object)

     Return ‘True’ if the object is a built-in function or a bound
     built-in method.

 -- Funzione: inspect.ismethodwrapper (object)

     Return ‘True’ if the type of object is a *note MethodWrapperType:
     85c.

     These are instances of *note MethodWrapperType: 85c, such as *note
     __str__(): 831, *note __eq__(): cf4. and *note __repr__(): 830.

     Added in version 3.11.

 -- Funzione: inspect.isroutine (object)

     Return ‘True’ if the object is a user-defined or built-in function
     or method.

 -- Funzione: inspect.isabstract (object)

     Return ‘True’ if the object is an abstract base class.

 -- Funzione: inspect.ismethoddescriptor (object)

     Return ‘True’ if the object is a method descriptor, but not if
     *note ismethod(): 4a06, *note isclass(): 4a05, *note isfunction():
     4a07. or *note isbuiltin(): 4a0d. are true.

     This, for example, is true of ‘int.__add__’.  An object passing
     this test has a *note __get__(): 16ef. method, but not a *note
     __set__(): 239b. method or a *note __delete__(): 1937. method.
     Beyond that, the set of attributes varies.  A *note __name__: 1268.
     attribute is usually sensible, and *note __doc__: b23. often is.

     Methods implemented via descriptors that also pass one of the other
     tests return ‘False’ from the *note ismethoddescriptor(): 1936.
     test, simply because the other tests promise more – you can, e.g.,
     count on having the *note __func__: 1504. attribute (etc) when an
     object passes *note ismethod(): 4a06.

     Cambiato nella versione 3.13: This function no longer incorrectly
     reports objects with *note __get__(): 16ef. and *note __delete__():
     1937, but not *note __set__(): 239b, as being method descriptors
     (such objects are data descriptors, not method descriptors).

 -- Funzione: inspect.isdatadescriptor (object)

     Return ‘True’ if the object is a data descriptor.

     Data descriptors have a *note __set__: 239b. or a *note __delete__:
     1937. method.  Examples are properties (defined in Python),
     getsets, and members.  The latter two are defined in C and there
     are more specific tests available for those types, which is robust
     across Python implementations.  Typically, data descriptors will
     also have *note __name__: 1268. and ‘__doc__’ attributes
     (properties, getsets, and members have both of these attributes),
     but this is not guaranteed.

 -- Funzione: inspect.isgetsetdescriptor (object)

     Return ‘True’ if the object is a getset descriptor.

     'Dettaglio dell’implementazione di CPython:' getsets are attributes
     defined in extension modules via *note PyGetSetDef: db4.
     structures.  For Python implementations without such types, this
     method will always return ‘False’.

 -- Funzione: inspect.ismemberdescriptor (object)

     Return ‘True’ if the object is a member descriptor.

     'Dettaglio dell’implementazione di CPython:' Member descriptors are
     attributes defined in extension modules via *note PyMemberDef: 772.
     structures.  For Python implementations without such types, this
     method will always return ‘False’.


File: python.info,  Node: Retrieving source code,  Next: Introspecting callables with the Signature object,  Prev: Types and members,  Up: inspect — Inspect live objects

5.29.14.2 Retrieving source code
................................

 -- Funzione: inspect.getdoc (object)

     Get the documentation string for an object, cleaned up with *note
     cleandoc(): 1a14.  If the documentation string for an object is not
     provided and the object is a class, a method, a property or a
     descriptor, retrieve the documentation string from the inheritance
     hierarchy.  Return ‘None’ if the documentation string is invalid or
     missing.

     Cambiato nella versione 3.5: Documentation strings are now
     inherited if not overridden.

 -- Funzione: inspect.getcomments (object)

     Return in a single string any lines of comments immediately
     preceding the object’s source code (for a class, function, or
     method), or at the top of the Python source file (if the object is
     a module).  If the object’s source code is unavailable, return
     ‘None’.  This could happen if the object has been defined in C or
     the interactive shell.

 -- Funzione: inspect.getfile (object)

     Return the name of the (text or binary) file in which an object was
     defined.  This will fail with a *note TypeError: 198. if the object
     is a built-in module, class, or function.

 -- Funzione: inspect.getmodule (object)

     Try to guess which module an object was defined in.  Return ‘None’
     if the module cannot be determined.

 -- Funzione: inspect.getsourcefile (object)

     Return the name of the Python source file in which an object was
     defined or ‘None’ if no way can be identified to get the source.
     This will fail with a *note TypeError: 198. if the object is a
     built-in module, class, or function.

 -- Funzione: inspect.getsourcelines (object)

     Return a list of source lines and starting line number for an
     object.  The argument may be a module, class, method, function,
     traceback, frame, or code object.  The source code is returned as a
     list of the lines corresponding to the object and the line number
     indicates where in the original source file the first line of code
     was found.  An *note OSError: 2c0. is raised if the source code
     cannot be retrieved.  A *note TypeError: 198. is raised if the
     object is a built-in module, class, or function.

     Cambiato nella versione 3.3: *note OSError: 2c0. is raised instead
     of *note IOError: 1255, now an alias of the former.

 -- Funzione: inspect.getsource (object)

     Return the text of the source code for an object.  The argument may
     be a module, class, method, function, traceback, frame, or code
     object.  The source code is returned as a single string.  An *note
     OSError: 2c0. is raised if the source code cannot be retrieved.  A
     *note TypeError: 198. is raised if the object is a built-in module,
     class, or function.

     Cambiato nella versione 3.3: *note OSError: 2c0. is raised instead
     of *note IOError: 1255, now an alias of the former.

 -- Funzione: inspect.cleandoc (doc)

     Clean up indentation from docstrings that are indented to line up
     with blocks of code.

     All leading whitespace is removed from the first line.  Any leading
     whitespace that can be uniformly removed from the second line
     onwards is removed.  Empty lines at the beginning and end are
     subsequently removed.  Also, all tabs are expanded to spaces.


File: python.info,  Node: Introspecting callables with the Signature object,  Next: Classes and functions<2>,  Prev: Retrieving source code,  Up: inspect — Inspect live objects

5.29.14.3 Introspecting callables with the Signature object
...........................................................

Added in version 3.3.

The *note Signature: 4e4. object represents the call signature of a
callable object and its return annotation.  To retrieve a ‘Signature’
object, use the ‘signature()’ function.

 -- Funzione: inspect.signature (callable, *, follow_wrapped=True,
          globals=None, locals=None, eval_str=False,
          annotation_format=Format.VALUE)

     Return a *note Signature: 4e4. object for the given 'callable':

          >>> from inspect import signature
          >>> def foo(a, *, b:int, **kwargs):
          ...     pass

          >>> sig = signature(foo)

          >>> str(sig)
          '(a, *, b: int, **kwargs)'

          >>> str(sig.parameters['b'])
          'b: int'

          >>> sig.parameters['b'].annotation
          <class 'int'>

     Accepts a wide range of Python callables, from plain functions and
     classes to *note functools.partial(): 217. objects.

     If some of the annotations are strings (e.g., because ‘from
     __future__ import annotations’ was used), *note signature(): 22f.
     will attempt to automatically un-stringize the annotations using
     *note annotationlib.get_annotations(): 459.  The 'globals',
     'locals', and 'eval_str' parameters are passed into
     ‘annotationlib.get_annotations()’ when resolving the annotations;
     see the documentation for ‘annotationlib.get_annotations()’ for
     instructions on how to use these parameters.  A member of the *note
     annotationlib.Format: 230. enum can be passed to the
     'annotation_format' parameter to control the format of the returned
     annotations.  For example, use
     ‘annotation_format=annotationlib.Format.STRING’ to return
     annotations in string format.

     Raises *note ValueError: 2ec. if no signature can be provided, and
     *note TypeError: 198. if that type of object is not supported.
     Also, if the annotations are stringized, and 'eval_str' is not
     false, the ‘eval()’ call(s) to un-stringize the annotations in
     *note annotationlib.get_annotations(): 459. could potentially raise
     any kind of exception.

     A slash (/) in the signature of a function denotes that the
     parameters prior to it are positional-only.  For more info, see
     *note the FAQ entry on positional-only parameters: 25b2.

     Cambiato nella versione 3.5: The 'follow_wrapped' parameter was
     added.  Pass ‘False’ to get a signature of 'callable' specifically
     (‘callable.__wrapped__’ will not be used to unwrap decorated
     callables.)

     Cambiato nella versione 3.10: The 'globals', 'locals', and
     'eval_str' parameters were added.

     Cambiato nella versione 3.14: The 'annotation_format' parameter was
     added.

          Nota: Some callables may not be introspectable in certain
          implementations of Python.  For example, in CPython, some
          built-in functions defined in C provide no metadata about
          their arguments.

     'Dettaglio dell’implementazione di CPython:' If the passed object
     has a ‘__signature__’ attribute, we may use it to create the
     signature.  The exact semantics are an implementation detail and
     are subject to unannounced changes.  Consult the source code for
     current semantics.

 -- Classe: inspect.Signature (parameters=None, *,
          return_annotation=Signature.empty)

     A ‘Signature’ object represents the call signature of a function
     and its return annotation.  For each parameter accepted by the
     function it stores a *note Parameter: 4e5. object in its *note
     parameters: 4a16. collection.

     The optional 'parameters' argument is a sequence of *note
     Parameter: 4e5. objects, which is validated to check that there are
     no parameters with duplicate names, and that the parameters are in
     the right order, i.e.  positional-only first, then
     positional-or-keyword, and that parameters with defaults follow
     parameters without defaults.

     The optional 'return_annotation' argument can be an arbitrary
     Python object.  It represents the «return» annotation of the
     callable.

     ‘Signature’ objects are 'immutable'.  Use *note
     Signature.replace(): 4a17. or *note copy.replace(): 1c0. to make a
     modified copy.

     Cambiato nella versione 3.5: ‘Signature’ objects are now picklable
     and *note hashable: 825.

      -- Attributo: empty

          A special class-level marker to specify absence of a return
          annotation.

      -- Attributo: parameters

          An ordered mapping of parameters” names to the corresponding
          *note Parameter: 4e5. objects.  Parameters appear in strict
          definition order, including keyword-only parameters.

          Cambiato nella versione 3.7: Python only explicitly guaranteed
          that it preserved the declaration order of keyword-only
          parameters as of version 3.7, although in practice this order
          had always been preserved in Python 3.

      -- Attributo: return_annotation

          The «return» annotation for the callable.  If the callable has
          no «return» annotation, this attribute is set to *note
          Signature.empty: 4a18.

      -- Metodo: bind (*args, **kwargs)

          Create a mapping from positional and keyword arguments to
          parameters.  Returns *note BoundArguments: 126b. if ‘*args’
          and ‘**kwargs’ match the signature, or raises a *note
          TypeError: 198.

      -- Metodo: bind_partial (*args, **kwargs)

          Works the same way as *note Signature.bind(): 187a, but allows
          the omission of some required arguments (mimics *note
          functools.partial(): 217. behavior.)  Returns *note
          BoundArguments: 126b, or raises a *note TypeError: 198. if the
          passed arguments do not match the signature.

      -- Metodo: replace (*[, parameters][, return_annotation])

          Create a new *note Signature: 4e4. instance based on the
          instance *note replace(): 4a17. was invoked on.  It is
          possible to pass different 'parameters' and/or
          'return_annotation' to override the corresponding properties
          of the base signature.  To remove ‘return_annotation’ from the
          copied ‘Signature’, pass in *note Signature.empty: 4a18.

               >>> def test(a, b):
               ...     pass
               ...
               >>> sig = signature(test)
               >>> new_sig = sig.replace(return_annotation="new return anno")
               >>> str(new_sig)
               "(a, b) -> 'new return anno'"

          *note Signature: 4e4. objects are also supported by the
          generic function *note copy.replace(): 1c0.

      -- Metodo: format (*, max_width=None,
               quote_annotation_strings=True)

          Create a string representation of the *note Signature: 4e4.
          object.

          If 'max_width' is passed, the method will attempt to fit the
          signature into lines of at most 'max_width' characters.  If
          the signature is longer than 'max_width', all parameters will
          be on separate lines.

          If 'quote_annotation_strings' is False, *note annotations:
          15c. in the signature are displayed without opening and
          closing quotation marks if they are strings.  This is useful
          if the signature was created with the *note STRING: 160.
          format or if ‘from __future__ import annotations’ was used.

          Added in version 3.13.

          Cambiato nella versione 3.14: The 'unquote_annotations'
          parameter was added.

      -- Metodo: classmethod from_callable (obj, *, follow_wrapped=True,
               globals=None, locals=None, eval_str=False)

          Return a *note Signature: 4e4. (or its subclass) object for a
          given callable 'obj'.

          This method simplifies subclassing of *note Signature: 4e4.:

               class MySignature(Signature):
                   pass
               sig = MySignature.from_callable(sum)
               assert isinstance(sig, MySignature)

          Its behavior is otherwise identical to that of *note
          signature(): 22f.

          Added in version 3.5.

          Cambiato nella versione 3.10: The 'globals', 'locals', and
          'eval_str' parameters were added.

 -- Classe: inspect.Parameter (name, kind, *, default=Parameter.empty,
          annotation=Parameter.empty)

     ‘Parameter’ objects are 'immutable'.  Instead of modifying a
     ‘Parameter’ object, you can use *note Parameter.replace(): 4a1b. or
     *note copy.replace(): 1c0. to create a modified copy.

     Cambiato nella versione 3.5: Parameter objects are now picklable
     and *note hashable: 825.

      -- Attributo: empty

          A special class-level marker to specify absence of default
          values and annotations.

      -- Attributo: name

          The name of the parameter as a string.  The name must be a
          valid Python identifier.

          'Dettaglio dell’implementazione di CPython:' CPython generates
          implicit parameter names of the form ‘.0’ on the code objects
          used to implement comprehensions and generator expressions.

          Cambiato nella versione 3.6: These parameter names are now
          exposed by this module as names like ‘implicit0’.

      -- Attributo: default

          The default value for the parameter.  If the parameter has no
          default value, this attribute is set to *note Parameter.empty:
          4a1c.

      -- Attributo: annotation

          The annotation for the parameter.  If the parameter has no
          annotation, this attribute is set to *note Parameter.empty:
          4a1c.

      -- Attributo: kind

          Describes how argument values are bound to the parameter.  The
          possible values are accessible via *note Parameter: 4e5. (like
          ‘Parameter.KEYWORD_ONLY’), and support comparison and
          ordering, in the following order:

          Name                         Meaning
                                       
          --------------------------------------------------------------------------------
                                       
          'POSITIONAL_ONLY'            Value must be supplied as a positional argument.
                                       Positional only parameters are those which
                                       appear before a ‘/’ entry (if present) in a
                                       Python function definition.
                                       
                                       
          'POSITIONAL_OR_KEYWORD'      Value may be supplied as either a keyword or
                                       positional argument (this is the standard
                                       binding behaviour for functions implemented in
                                       Python.)
                                       
                                       
          'VAR_POSITIONAL'             A tuple of positional arguments that aren’t
                                       bound to any other parameter.  This corresponds
                                       to a ‘*args’ parameter in a Python function
                                       definition.
                                       
                                       
          'KEYWORD_ONLY'               Value must be supplied as a keyword argument.
                                       Keyword only parameters are those which appear
                                       after a ‘*’ or ‘*args’ entry in a Python
                                       function definition.
                                       
                                       
          'VAR_KEYWORD'                A dict of keyword arguments that aren’t bound to
                                       any other parameter.  This corresponds to a
                                       ‘**kwargs’ parameter in a Python function
                                       definition.
                                       

          Example: print all keyword-only arguments without default
          values:

               >>> def foo(a, b, *, c, d=10):
               ...     pass

               >>> sig = signature(foo)
               >>> for param in sig.parameters.values():
               ...     if (param.kind == param.KEYWORD_ONLY and
               ...                        param.default is param.empty):
               ...         print('Parameter:', param)
               Parameter: c

      -- Attributo: kind.description

          Describes an enum value of *note Parameter.kind: 4a20.

          Added in version 3.8.

          Example: print all descriptions of arguments:

               >>> def foo(a, b, *, c, d=10):
               ...     pass

               >>> sig = signature(foo)
               >>> for param in sig.parameters.values():
               ...     print(param.kind.description)
               positional or keyword
               positional or keyword
               keyword-only
               keyword-only

      -- Metodo: replace (*[, name][, kind][, default][, annotation])

          Create a new *note Parameter: 4e5. instance based on the
          instance replaced was invoked on.  To override a ‘Parameter’
          attribute, pass the corresponding argument.  To remove a
          default value or/and an annotation from a ‘Parameter’, pass
          *note Parameter.empty: 4a1c.

               >>> from inspect import Parameter
               >>> param = Parameter('foo', Parameter.KEYWORD_ONLY, default=42)
               >>> str(param)
               'foo=42'

               >>> str(param.replace()) # Will create a shallow copy of 'param'
               'foo=42'

               >>> str(param.replace(default=Parameter.empty, annotation='spam'))
               "foo: 'spam'"

          *note Parameter: 4e5. objects are also supported by the
          generic function *note copy.replace(): 1c0.

     Cambiato nella versione 3.4: In Python 3.3 *note Parameter: 4e5.
     objects were allowed to have ‘name’ set to ‘None’ if their ‘kind’
     was set to ‘POSITIONAL_ONLY’.  This is no longer permitted.

 -- Classe: inspect.BoundArguments

     Result of a *note Signature.bind(): 187a. or *note
     Signature.bind_partial(): 4a1a. call.  Holds the mapping of
     arguments to the function’s parameters.

      -- Attributo: arguments

          A mutable mapping of parameters” names to arguments” values.
          Contains only explicitly bound arguments.  Changes in *note
          arguments: b0a. will reflect in *note args: 4a22. and *note
          kwargs: 4a23.

          Should be used in conjunction with *note Signature.parameters:
          4a16. for any argument processing purposes.

               Nota: Arguments for which *note Signature.bind(): 187a.
               or *note Signature.bind_partial(): 4a1a. relied on a
               default value are skipped.  However, if needed, use *note
               BoundArguments.apply_defaults(): 1018. to add them.

          Cambiato nella versione 3.9: *note arguments: b0a. is now of
          type *note dict: 183.  Formerly, it was of type *note
          collections.OrderedDict: 7f4.

      -- Attributo: args

          A tuple of positional arguments values.  Dynamically computed
          from the *note arguments: b0a. attribute.

      -- Attributo: kwargs

          A dict of keyword arguments values.  Dynamically computed from
          the *note arguments: b0a. attribute.  Arguments that can be
          passed positionally are included in *note args: 4a22. instead.

      -- Attributo: signature

          A reference to the parent *note Signature: 4e4. object.

      -- Metodo: apply_defaults ()

          Set default values for missing arguments.

          For variable-positional arguments (‘*args’) the default is an
          empty tuple.

          For variable-keyword arguments (‘**kwargs’) the default is an
          empty dict.

               >>> def foo(a, b='ham', *args): pass
               >>> ba = inspect.signature(foo).bind('spam')
               >>> ba.apply_defaults()
               >>> ba.arguments
               {'a': 'spam', 'b': 'ham', 'args': ()}

          Added in version 3.5.

     The *note args: 4a22. and *note kwargs: 4a23. properties can be
     used to invoke functions:

          def test(a, *, b):
              ...

          sig = signature(test)
          ba = sig.bind(10, b=20)
          test(*ba.args, **ba.kwargs)

Vedi anche
..........

PEP 362(1) - Function Signature Object.

     The detailed specification, implementation details and examples.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0362/


File: python.info,  Node: Classes and functions<2>,  Next: The interpreter stack,  Prev: Introspecting callables with the Signature object,  Up: inspect — Inspect live objects

5.29.14.4 Classes and functions
...............................

 -- Funzione: inspect.getclasstree (classes, unique=False)

     Arrange the given list of classes into a hierarchy of nested lists.
     Where a nested list appears, it contains classes derived from the
     class whose entry immediately precedes the list.  Each entry is a
     2-tuple containing a class and a tuple of its base classes.  If the
     'unique' argument is true, exactly one entry appears in the
     returned structure for each class in the given list.  Otherwise,
     classes using multiple inheritance and their descendants will
     appear multiple times.

 -- Funzione: inspect.getfullargspec (func)

     Get the names and default values of a Python function’s parameters.
     A *note named tuple: 85f. is returned:

     ‘FullArgSpec(args, varargs, varkw, defaults, kwonlyargs,
     kwonlydefaults, annotations)’

     'args' is a list of the positional parameter names.  'varargs' is
     the name of the ‘*’ parameter or ‘None’ if arbitrary positional
     arguments are not accepted.  'varkw' is the name of the ‘**’
     parameter or ‘None’ if arbitrary keyword arguments are not
     accepted.  'defaults' is an 'n'-tuple of default argument values
     corresponding to the last 'n' positional parameters, or ‘None’ if
     there are no such defaults defined.  'kwonlyargs' is a list of
     keyword-only parameter names in declaration order.
     'kwonlydefaults' is a dictionary mapping parameter names from
     'kwonlyargs' to the default values used if no argument is supplied.
     'annotations' is a dictionary mapping parameter names to
     annotations.  The special key ‘"return"’ is used to report the
     function return value annotation (if any).

     Note that *note signature(): 22f. and *note Signature Object: 4a14.
     provide the recommended API for callable introspection, and support
     additional behaviours (like positional-only arguments) that are
     sometimes encountered in extension module APIs.  This function is
     retained primarily for use in code that needs to maintain
     compatibility with the Python 2 ‘inspect’ module API.

     Cambiato nella versione 3.4: This function is now based on *note
     signature(): 22f, but still ignores ‘__wrapped__’ attributes and
     includes the already bound first parameter in the signature output
     for bound methods.

     Cambiato nella versione 3.6: This method was previously documented
     as deprecated in favour of *note signature(): 22f. in Python 3.5,
     but that decision has been reversed in order to restore a clearly
     supported standard interface for single-source Python 2/3 code
     migrating away from the legacy ‘getargspec()’ API.

     Cambiato nella versione 3.7: Python only explicitly guaranteed that
     it preserved the declaration order of keyword-only parameters as of
     version 3.7, although in practice this order had always been
     preserved in Python 3.

 -- Funzione: inspect.getargvalues (frame)

     Get information about arguments passed into a particular frame.  A
     *note named tuple: 85f. ‘ArgInfo(args, varargs, keywords, locals)’
     is returned.  'args' is a list of the argument names.  'varargs'
     and 'keywords' are the names of the ‘*’ and ‘**’ arguments or
     ‘None’.  'locals' is the locals dictionary of the given frame.

          Nota: This function was inadvertently marked as deprecated in
          Python 3.5.

 -- Funzione: inspect.formatargvalues (args[, varargs, varkw, locals,
          formatarg, formatvarargs, formatvarkw, formatvalue])

     Format a pretty argument spec from the four values returned by
     *note getargvalues(): 10c1.  The format* arguments are the
     corresponding optional formatting functions that are called to turn
     names and values into strings.

          Nota: This function was inadvertently marked as deprecated in
          Python 3.5.

 -- Funzione: inspect.getmro (cls)

     Return a tuple of class cls’s base classes, including cls, in
     method resolution order.  No class appears more than once in this
     tuple.  Note that the method resolution order depends on cls’s
     type.  Unless a very peculiar user-defined metatype is in use, cls
     will be the first element of the tuple.

 -- Funzione: inspect.getcallargs (func, /, *args, **kwds)

     Bind the 'args' and 'kwds' to the argument names of the Python
     function or method 'func', as if it was called with them.  For
     bound methods, bind also the first argument (typically named
     ‘self’) to the associated instance.  A dict is returned, mapping
     the argument names (including the names of the ‘*’ and ‘**’
     arguments, if any) to their values from 'args' and 'kwds'.  In case
     of invoking 'func' incorrectly, i.e.  whenever ‘func(*args,
     **kwds)’ would raise an exception because of incompatible
     signature, an exception of the same type and the same or similar
     message is raised.  For example:

          >>> from inspect import getcallargs
          >>> def f(a, b=1, *pos, **named):
          ...     pass
          ...
          >>> getcallargs(f, 1, 2, 3) == {'a': 1, 'named': {}, 'b': 2, 'pos': (3,)}
          True
          >>> getcallargs(f, a=2, x=4) == {'a': 2, 'named': {'x': 4}, 'b': 1, 'pos': ()}
          True
          >>> getcallargs(f)
          Traceback (most recent call last):
          ...
          TypeError: f() missing 1 required positional argument: 'a'

     Added in version 3.2.

     Deprecato dalla versione 3.5: Use *note Signature.bind(): 187a. and
     *note Signature.bind_partial(): 4a1a. instead.

 -- Funzione: inspect.getclosurevars (func)

     Get the mapping of external name references in a Python function or
     method 'func' to their current values.  A *note named tuple: 85f.
     ‘ClosureVars(nonlocals, globals, builtins, unbound)’ is returned.
     'nonlocals' maps referenced names to lexical closure variables,
     'globals' to the function’s module globals and 'builtins' to the
     builtins visible from the function body.  'unbound' is the set of
     names referenced in the function that could not be resolved at all
     given the current module globals and builtins.

     *note TypeError: 198. is raised if 'func' is not a Python function
     or method.

     Added in version 3.3.

 -- Funzione: inspect.unwrap (func, *, stop=None)

     Get the object wrapped by 'func'.  It follows the chain of
     ‘__wrapped__’ attributes returning the last object in the chain.

     'stop' is an optional callback accepting an object in the wrapper
     chain as its sole argument that allows the unwrapping to be
     terminated early if the callback returns a true value.  If the
     callback never returns a true value, the last object in the chain
     is returned as usual.  For example, *note signature(): 22f. uses
     this to stop unwrapping if any object in the chain has a
     ‘__signature__’ attribute defined.

     *note ValueError: 2ec. is raised if a cycle is encountered.

     Added in version 3.4.

 -- Funzione: inspect.get_annotations (obj, *, globals=None,
          locals=None, eval_str=False,
          format=annotationlib.Format.VALUE)

     Compute the annotations dict for an object.

     This is an alias for *note annotationlib.get_annotations(): 459.;
     see the documentation of that function for more information.

          Attenzione: This function may execute arbitrary code contained
          in annotations.  See *note Security implications of
          introspecting annotations: 44ff. for more information.

     Added in version 3.10.

     Cambiato nella versione 3.14: This function is now an alias for
     *note annotationlib.get_annotations(): 459.  Calling it as
     ‘inspect.get_annotations’ will continue to work.


File: python.info,  Node: The interpreter stack,  Next: Fetching attributes statically,  Prev: Classes and functions<2>,  Up: inspect — Inspect live objects

5.29.14.5 The interpreter stack
...............................

Some of the following functions return *note FrameInfo: 85d. objects.
For backwards compatibility these objects allow tuple-like operations on
all attributes except ‘positions’.  This behavior is considered
deprecated and may be removed in the future.

 -- Classe: inspect.FrameInfo

      -- Attributo: frame

          The *note frame object: 8f0. that the record corresponds to.

      -- Attributo: filename

          The file name associated with the code being executed by the
          frame this record corresponds to.

      -- Attributo: lineno

          The line number of the current line associated with the code
          being executed by the frame this record corresponds to.

      -- Attributo: function

          The function name that is being executed by the frame this
          record corresponds to.

      -- Attributo: code_context

          A list of lines of context from the source code that’s being
          executed by the frame this record corresponds to.

      -- Attributo: index

          The index of the current line being executed in the *note
          code_context: 4a2f. list.

      -- Attributo: positions

          A *note dis.Positions: 1928. object containing the start line
          number, end line number, start column offset, and end column
          offset associated with the instruction being executed by the
          frame this record corresponds to.

     Cambiato nella versione 3.5: Return a *note named tuple: 85f.
     instead of a *note tuple: 614.

     Cambiato nella versione 3.11: ‘FrameInfo’ is now a class instance
     (that is backwards compatible with the previous *note named tuple:
     85f.).

 -- Classe: inspect.Traceback

      -- Attributo: filename

          The file name associated with the code being executed by the
          frame this traceback corresponds to.

      -- Attributo: lineno

          The line number of the current line associated with the code
          being executed by the frame this traceback corresponds to.

      -- Attributo: function

          The function name that is being executed by the frame this
          traceback corresponds to.

      -- Attributo: code_context

          A list of lines of context from the source code that’s being
          executed by the frame this traceback corresponds to.

      -- Attributo: index

          The index of the current line being executed in the *note
          code_context: 4a35. list.

      -- Attributo: positions

          A *note dis.Positions: 1928. object containing the start line
          number, end line number, start column offset, and end column
          offset associated with the instruction being executed by the
          frame this traceback corresponds to.

     Cambiato nella versione 3.11: ‘Traceback’ is now a class instance
     (that is backwards compatible with the previous *note named tuple:
     85f.).

     Nota: Keeping references to frame objects, as found in the first
     element of the frame records these functions return, can cause your
     program to create reference cycles.  Once a reference cycle has
     been created, the lifespan of all objects which can be accessed
     from the objects which form the cycle can become much longer even
     if Python’s optional cycle detector is enabled.  If such cycles
     must be created, it is important to ensure they are explicitly
     broken to avoid the delayed destruction of objects and increased
     memory consumption which occurs.

     Though the cycle detector will catch these, destruction of the
     frames (and local variables) can be made deterministic by removing
     the cycle in a *note finally: 1b0. clause.  This is also important
     if the cycle detector was disabled when Python was compiled or
     using *note gc.disable(): 49f7.  For example:

          def handle_stackframe_without_leak():
              frame = inspect.currentframe()
              try:
                  # do something with the frame
              finally:
                  del frame

     If you want to keep the frame around (for example to print a
     traceback later), you can also break reference cycles by using the
     *note frame.clear(): 585. method.

The optional 'context' argument supported by most of these functions
specifies the number of lines of context to return, which are centered
around the current line.

 -- Funzione: inspect.getframeinfo (frame, context=1)

     Get information about a frame or traceback object.  A *note
     Traceback: 85e. object is returned.

     Cambiato nella versione 3.11: A *note Traceback: 85e. object is
     returned instead of a named tuple.

 -- Funzione: inspect.getouterframes (frame, context=1)

     Get a list of *note FrameInfo: 85d. objects for a frame and all
     outer frames.  These frames represent the calls that lead to the
     creation of 'frame'.  The first entry in the returned list
     represents 'frame'; the last entry represents the outermost call on
     'frame'’s stack.

     Cambiato nella versione 3.5: A list of *note named tuples: 85f.
     ‘FrameInfo(frame, filename, lineno, function, code_context, index)’
     is returned.

     Cambiato nella versione 3.11: A list of *note FrameInfo: 85d.
     objects is returned.

 -- Funzione: inspect.getinnerframes (traceback, context=1)

     Get a list of *note FrameInfo: 85d. objects for a traceback’s frame
     and all inner frames.  These frames represent calls made as a
     consequence of 'frame'.  The first entry in the list represents
     'traceback'; the last entry represents where the exception was
     raised.

     Cambiato nella versione 3.5: A list of *note named tuples: 85f.
     ‘FrameInfo(frame, filename, lineno, function, code_context, index)’
     is returned.

     Cambiato nella versione 3.11: A list of *note FrameInfo: 85d.
     objects is returned.

 -- Funzione: inspect.currentframe ()

     Return the frame object for the caller’s stack frame.

     'Dettaglio dell’implementazione di CPython:' This function relies
     on Python stack frame support in the interpreter, which isn’t
     guaranteed to exist in all implementations of Python.  If running
     in an implementation without Python stack frame support this
     function returns ‘None’.

 -- Funzione: inspect.stack (context=1)

     Return a list of *note FrameInfo: 85d. objects for the caller’s
     stack.  The first entry in the returned list represents the caller;
     the last entry represents the outermost call on the stack.

     Cambiato nella versione 3.5: A list of *note named tuples: 85f.
     ‘FrameInfo(frame, filename, lineno, function, code_context, index)’
     is returned.

     Cambiato nella versione 3.11: A list of *note FrameInfo: 85d.
     objects is returned.

 -- Funzione: inspect.trace (context=1)

     Return a list of *note FrameInfo: 85d. objects for the stack
     between the current frame and the frame in which an exception
     currently being handled was raised in.  The first entry in the list
     represents the caller; the last entry represents where the
     exception was raised.

     Cambiato nella versione 3.5: A list of *note named tuples: 85f.
     ‘FrameInfo(frame, filename, lineno, function, code_context, index)’
     is returned.

     Cambiato nella versione 3.11: A list of *note FrameInfo: 85d.
     objects is returned.


File: python.info,  Node: Fetching attributes statically,  Next: Current State of Generators Coroutines and Asynchronous Generators,  Prev: The interpreter stack,  Up: inspect — Inspect live objects

5.29.14.6 Fetching attributes statically
........................................

Both *note getattr(): dcc. and *note hasattr(): 6fa. can trigger code
execution when fetching or checking for the existence of attributes.
Descriptors, like properties, will be invoked and *note __getattr__():
6fb. and *note __getattribute__(): dcd. may be called.

For cases where you want passive introspection, like documentation
tools, this can be inconvenient.  *note getattr_static(): 6bd. has the
same signature as *note getattr(): dcc. but avoids executing code when
it fetches attributes.

 -- Funzione: inspect.getattr_static (obj, attr, default=None)

     Retrieve attributes without triggering dynamic lookup via the
     descriptor protocol, *note __getattr__(): 6fb. or *note
     __getattribute__(): dcd.

     Note: this function may not be able to retrieve all attributes that
     getattr can fetch (like dynamically created attributes) and may
     find attributes that getattr can’t (like descriptors that raise
     AttributeError).  It can also return descriptors objects instead of
     instance members.

     If the instance *note __dict__: 77e. is shadowed by another member
     (for example a property) then this function will be unable to find
     instance members.

     Added in version 3.2.

*note getattr_static(): 6bd. does not resolve descriptors, for example
slot descriptors or getset descriptors on objects implemented in C. The
descriptor object is returned instead of the underlying attribute.

You can handle these with code like the following.  Note that for
arbitrary getset descriptors invoking these may trigger code execution:

     # example code for resolving the builtin descriptor types
     class _foo:
         __slots__ = ['foo']

     slot_descriptor = type(_foo.foo)
     getset_descriptor = type(type(open(__file__)).name)
     wrapper_descriptor = type(str.__dict__['__add__'])
     descriptor_types = (slot_descriptor, getset_descriptor, wrapper_descriptor)

     result = getattr_static(some_object, 'foo')
     if type(result) in descriptor_types:
         try:
             result = result.__get__()
         except AttributeError:
             # descriptors can raise AttributeError to
             # indicate there is no underlying value
             # in which case the descriptor itself will
             # have to do
             pass


File: python.info,  Node: Current State of Generators Coroutines and Asynchronous Generators,  Next: Code Objects Bit Flags,  Prev: Fetching attributes statically,  Up: inspect — Inspect live objects

5.29.14.7 Current State of Generators, Coroutines, and Asynchronous Generators
..............................................................................

When implementing coroutine schedulers and for other advanced uses of
generators, it is useful to determine whether a generator is currently
executing, is waiting to start or resume or execution, or has already
terminated.  *note getgeneratorstate(): 143e. allows the current state
of a generator to be determined easily.

 -- Funzione: inspect.getgeneratorstate (generator)

     Get current state of a generator-iterator.

     Possible states are:

        * GEN_CREATED: Waiting to start execution.

        * GEN_RUNNING: Currently being executed by the interpreter.

        * GEN_SUSPENDED: Currently suspended at a yield expression.

        * GEN_CLOSED: Execution has completed.

     Added in version 3.2.

 -- Funzione: inspect.getcoroutinestate (coroutine)

     Get current state of a coroutine object.  The function is intended
     to be used with coroutine objects created by *note async def: 7ee.
     functions, but will accept any coroutine-like object that has
     ‘cr_running’ and ‘cr_frame’ attributes.

     Possible states are:

        * CORO_CREATED: Waiting to start execution.

        * CORO_RUNNING: Currently being executed by the interpreter.

        * CORO_SUSPENDED: Currently suspended at an await expression.

        * CORO_CLOSED: Execution has completed.

     Added in version 3.5.

 -- Funzione: inspect.getasyncgenstate (agen)

     Get current state of an asynchronous generator object.  The
     function is intended to be used with asynchronous iterator objects
     created by *note async def: 7ee. functions which use the *note
     yield: bc4. statement, but will accept any asynchronous
     generator-like object that has ‘ag_running’ and ‘ag_frame’
     attributes.

     Possible states are:

        * AGEN_CREATED: Waiting to start execution.

        * AGEN_RUNNING: Currently being executed by the interpreter.

        * AGEN_SUSPENDED: Currently suspended at a yield expression.

        * AGEN_CLOSED: Execution has completed.

     Added in version 3.12.

The current internal state of the generator can also be queried.  This
is mostly useful for testing purposes, to ensure that internal state is
being updated as expected:

 -- Funzione: inspect.getgeneratorlocals (generator)

     Get the mapping of live local variables in 'generator' to their
     current values.  A dictionary is returned that maps from variable
     names to values.  This is the equivalent of calling *note locals():
     46f. in the body of the generator, and all the same caveats apply.

     If 'generator' is a *note generator: 1263. with no currently
     associated frame, then an empty dictionary is returned.  *note
     TypeError: 198. is raised if 'generator' is not a Python generator
     object.

     'Dettaglio dell’implementazione di CPython:' This function relies
     on the generator exposing a Python stack frame for introspection,
     which isn’t guaranteed to be the case in all implementations of
     Python.  In such cases, this function will always return an empty
     dictionary.

     Added in version 3.3.

 -- Funzione: inspect.getcoroutinelocals (coroutine)

     This function is analogous to *note getgeneratorlocals(): 12de, but
     works for coroutine objects created by *note async def: 7ee.
     functions.

     Added in version 3.5.

 -- Funzione: inspect.getasyncgenlocals (agen)

     This function is analogous to *note getgeneratorlocals(): 12de, but
     works for asynchronous generator objects created by *note async
     def: 7ee. functions which use the *note yield: bc4. statement.

     Added in version 3.12.


File: python.info,  Node: Code Objects Bit Flags,  Next: Buffer flags,  Prev: Current State of Generators Coroutines and Asynchronous Generators,  Up: inspect — Inspect live objects

5.29.14.8 Code Objects Bit Flags
................................

Python code objects have a *note co_flags: 18c3. attribute, which is a
bitmap of the following flags:

 -- Dati: inspect.CO_OPTIMIZED

     The code object is optimized, using fast locals.

 -- Dati: inspect.CO_NEWLOCALS

     If set, a new dict will be created for the frame’s *note f_locals:
     4a6. when the code object is executed.

 -- Dati: inspect.CO_VARARGS

     The code object has a variable positional parameter (‘*args’-like).

 -- Dati: inspect.CO_VARKEYWORDS

     The code object has a variable keyword parameter (‘**kwargs’-like).

 -- Dati: inspect.CO_NESTED

     The flag is set when the code object is a nested function.

 -- Dati: inspect.CO_GENERATOR

     The flag is set when the code object is a generator function, i.e.
     a generator object is returned when the code object is executed.

 -- Dati: inspect.CO_COROUTINE

     The flag is set when the code object is a coroutine function.  When
     the code object is executed it returns a coroutine object.  See PEP
     492(1) for more details.

     Added in version 3.5.

 -- Dati: inspect.CO_ITERABLE_COROUTINE

     The flag is used to transform generators into generator-based
     coroutines.  Generator objects with this flag can be used in
     ‘await’ expression, and can ‘yield from’ coroutine objects.  See
     PEP 492(2) for more details.

     Added in version 3.5.

 -- Dati: inspect.CO_ASYNC_GENERATOR

     The flag is set when the code object is an asynchronous generator
     function.  When the code object is executed it returns an
     asynchronous generator object.  See PEP 525(3) for more details.

     Added in version 3.6.

 -- Dati: inspect.CO_HAS_DOCSTRING

     The flag is set when there is a docstring for the code object in
     the source code.  If set, it will be the first item in *note
     co_consts: 1883.

     Added in version 3.14.

 -- Dati: inspect.CO_METHOD

     The flag is set when the code object is a function defined in class
     scope.

     Added in version 3.14.

     Nota: The flags are specific to CPython, and may not be defined in
     other Python implementations.  Furthermore, the flags are an
     implementation detail, and can be removed or deprecated in future
     Python releases.  It’s recommended to use public APIs from the
     *note inspect: 82. module for any introspection needs.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0492/

   (2) https://peps.python.org/pep-0492/

   (3) https://peps.python.org/pep-0525/


File: python.info,  Node: Buffer flags,  Next: Command-line interface<10>,  Prev: Code Objects Bit Flags,  Up: inspect — Inspect live objects

5.29.14.9 Buffer flags
......................

 -- Classe: inspect.BufferFlags

     This is an *note enum.IntFlag: e9c. that represents the flags that
     can be passed to the *note __buffer__(): 68d. method of objects
     implementing the *note buffer protocol: 260.

     The meaning of the flags is explained at *note Buffer request
     types: 4a46.

      -- Attributo: SIMPLE

      -- Attributo: WRITABLE

      -- Attributo: FORMAT

      -- Attributo: ND

      -- Attributo: STRIDES

      -- Attributo: C_CONTIGUOUS

      -- Attributo: F_CONTIGUOUS

      -- Attributo: ANY_CONTIGUOUS

      -- Attributo: INDIRECT

      -- Attributo: CONTIG

      -- Attributo: CONTIG_RO

      -- Attributo: STRIDED

      -- Attributo: STRIDED_RO

      -- Attributo: RECORDS

      -- Attributo: RECORDS_RO

      -- Attributo: FULL

      -- Attributo: FULL_RO

      -- Attributo: READ

      -- Attributo: WRITE

     Added in version 3.12.


File: python.info,  Node: Command-line interface<10>,  Prev: Buffer flags,  Up: inspect — Inspect live objects

5.29.14.10 Command-line interface
.................................

The *note inspect: 82. module also provides a basic introspection
capability from the command line.

By default, accepts the name of a module and prints the source of that
module.  A class or function within the module can be printed instead by
appended a colon and the qualified name of the target object.

 -- Option: --details

     Print information about the specified object rather than the source
     code


File: python.info,  Node: annotationlib — Functionality for introspecting annotations,  Next: site — Site-specific configuration hook,  Prev: inspect — Inspect live objects,  Up: Python Runtime Services

5.29.15 ‘annotationlib’ — Functionality for introspecting annotations
---------------------------------------------------------------------

Added in version 3.14.

'Source code:' Lib/annotationlib.py(1)

__________________________________________________________________

The ‘annotationlib’ module provides tools for introspecting *note
annotations: 15c. on modules, classes, and functions.

Annotations are *note lazily evaluated: 686. and often contain forward
references to objects that are not yet defined when the annotation is
created.  This module provides a set of low-level tools that can be used
to retrieve annotations in a reliable way, even in the presence of
forward references and other edge cases.

This module supports retrieving annotations in three main formats (see
*note Format: 230.), each of which works best for different use cases:

   * *note VALUE: 15e. evaluates the annotations and returns their
     value.  This is most straightforward to work with, but it may raise
     errors, for example if the annotations contain references to
     undefined names.

   * *note FORWARDREF: 15f. returns *note ForwardRef: 175d. objects for
     annotations that cannot be resolved, allowing you to inspect the
     annotations without evaluating them.  This is useful when you need
     to work with annotations that may contain unresolved forward
     references.

   * *note STRING: 160. returns the annotations as a string, similar to
     how it would appear in the source file.  This is useful for
     documentation generators that want to display annotations in a
     readable way.

The *note get_annotations(): 459. function is the main entry point for
retrieving annotations.  Given a function, class, or module, it returns
an annotations dictionary in the requested format.  This module also
provides functionality for working directly with the *note annotate
function: 15d. that is used to evaluate annotations, such as *note
get_annotate_from_class_namespace(): 45b. and *note
call_annotate_function(): 17a6, as well as the *note
call_evaluate_function(): 44d7. function for working with *note evaluate
functions: 44d6.

     Attenzione: Most functionality in this module can execute arbitrary
     code; see *note the security section: 44ff. for more information.

Vedi anche
..........

PEP 649(2) proposed the current model for how annotations work in
Python.

PEP 749(3) expanded on various aspects of PEP 649(4) and introduced the
‘annotationlib’ module.

*note Annotations Best Practices: 9db. provides best practices for
working with annotations.

typing-extensions(5) provides a backport of *note get_annotations():
459. that works on earlier versions of Python.

* Menu:

* Annotation semantics::
* Classes: Classes<4>.
* Functions: Functions<11>.
* Recipes: Recipes<3>.
* Limitations of the STRING format::
* Limitations of the FORWARDREF format::
* Security implications of introspecting annotations::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/annotationlib.py

   (2) https://peps.python.org/pep-0649/

   (3) https://peps.python.org/pep-0749/

   (4) https://peps.python.org/pep-0649/

   (5) https://pypi.org/project/typing-extensions/


File: python.info,  Node: Annotation semantics,  Next: Classes<4>,  Up: annotationlib — Functionality for introspecting annotations

5.29.15.1 Annotation semantics
..............................

The way annotations are evaluated has changed over the history of Python
3, and currently still depends on a *note future import: 45d.  There
have been execution models for annotations:

   * 'Stock semantics' (default in Python 3.0 through 3.13; see PEP
     3107(1) and PEP 526(2)): Annotations are evaluated eagerly, as they
     are encountered in the source code.

   * 'Stringified annotations' (used with ‘from __future__ import
     annotations’ in Python 3.7 and newer; see PEP 563(3)): Annotations
     are stored as strings only.

   * 'Deferred evaluation' (default in Python 3.14 and newer; see PEP
     649(4) and PEP 749(5)): Annotations are evaluated lazily, only when
     they are accessed.

As an example, consider the following program:

     def func(a: Cls) -> None:
         print(a)

     class Cls: pass

     print(func.__annotations__)

This will behave as follows:

   * Under stock semantics (Python 3.13 and earlier), it will throw a
     *note NameError: 452. at the line where ‘func’ is defined, because
     ‘Cls’ is an undefined name at that point.

   * Under stringified annotations (if ‘from __future__ import
     annotations’ is used), it will print ‘{'a': 'Cls', 'return':
     'None'}’.

   * Under deferred evaluation (Python 3.14 and later), it will print
     ‘{'a': <class 'Cls'>, 'return': None}’.

Stock semantics were used when function annotations were first
introduced in Python 3.0 (by PEP 3107(6)) because this was the simplest,
most obvious way to implement annotations.  The same execution model was
used when variable annotations were introduced in Python 3.6 (by PEP
526(7)).  However, stock semantics caused problems when using
annotations as type hints, such as a need to refer to names that are not
yet defined when the annotation is encountered.  In addition, there were
performance problems with executing annotations at module import time.
Therefore, in Python 3.7, PEP 563(8) introduced the ability to store
annotations as strings using the ‘from __future__ import annotations’
syntax.  The plan at the time was to eventually make this behavior the
default, but a problem appeared: stringified annotations are more
difficult to process for those who introspect annotations at runtime.
An alternative proposal, PEP 649(9), introduced the third execution
model, deferred evaluation, and was implemented in Python 3.14.
Stringified annotations are still used if ‘from __future__ import
annotations’ is present, but this behavior will eventually be removed.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3107/

   (2) https://peps.python.org/pep-0526/

   (3) https://peps.python.org/pep-0563/

   (4) https://peps.python.org/pep-0649/

   (5) https://peps.python.org/pep-0749/

   (6) https://peps.python.org/pep-3107/

   (7) https://peps.python.org/pep-0526/

   (8) https://peps.python.org/pep-0563/

   (9) https://peps.python.org/pep-0649/


File: python.info,  Node: Classes<4>,  Next: Functions<11>,  Prev: Annotation semantics,  Up: annotationlib — Functionality for introspecting annotations

5.29.15.2 Classes
.................

 -- Classe: annotationlib.Format

     An *note IntEnum: edd. describing the formats in which annotations
     can be returned.  Members of the enum, or their equivalent integer
     values, can be passed to *note get_annotations(): 459. and other
     functions in this module, as well as to *note __annotate__: 196b.
     functions.

      -- Attributo: VALUE = 1

          Values are the result of evaluating the annotation
          expressions.

      -- Attributo: VALUE_WITH_FAKE_GLOBALS = 2

          Special value used to signal that an annotate function is
          being evaluated in a special environment with fake globals.
          When passed this value, annotate functions should either
          return the same value as for the *note Format.VALUE: 15e.
          format, or raise *note NotImplementedError: 36b. to signal
          that they do not support execution in this environment.  This
          format is only used internally and should not be passed to the
          functions in this module.

      -- Attributo: FORWARDREF = 3

          Values are real annotation values (as per *note Format.VALUE:
          15e. format) for defined values, and *note ForwardRef: 175d.
          proxies for undefined values.  Real objects may contain
          references to *note ForwardRef: 175d. proxy objects.

      -- Attributo: STRING = 4

          Values are the text string of the annotation as it appears in
          the source code, up to modifications including, but not
          restricted to, whitespace normalizations and constant values
          optimizations.

          The exact values of these strings may change in future
          versions of Python.

     Added in version 3.14.

 -- Classe: annotationlib.ForwardRef

     A proxy object for forward references in annotations.

     Instances of this class are returned when the *note FORWARDREF:
     15f. format is used and annotations contain a name that cannot be
     resolved.  This can happen when a forward reference is used in an
     annotation, such as when a class is referenced before it is
     defined.

      -- Attributo: __forward_arg__

          A string containing the code that was evaluated to produce the
          *note ForwardRef: 175d.  The string may not be exactly
          equivalent to the original source.

      -- Metodo: evaluate (*, owner=None, globals=None, locals=None,
               type_params=None, format=Format.VALUE)

          Evaluate the forward reference, returning its value.

          If the 'format' argument is *note VALUE: 15e. (the default),
          this method may throw an exception, such as *note NameError:
          452, if the forward reference refers to a name that cannot be
          resolved.  The arguments to this method can be used to provide
          bindings for names that would otherwise be undefined.  If the
          'format' argument is *note FORWARDREF: 15f, the method will
          never throw an exception, but may return a *note ForwardRef:
          175d. instance.  For example, if the forward reference object
          contains the code ‘list[undefined]’, where ‘undefined’ is a
          name that is not defined, evaluating it with the *note
          FORWARDREF: 15f. format will return
          ‘list[ForwardRef('undefined')]’.  If the 'format' argument is
          *note STRING: 160, the method will return *note
          __forward_arg__: 4a60.

          The 'owner' parameter provides the preferred mechanism for
          passing scope information to this method.  The owner of a
          *note ForwardRef: 175d. is the object that contains the
          annotation from which the *note ForwardRef: 175d. derives,
          such as a module object, type object, or function object.

          The 'globals', 'locals', and 'type_params' parameters provide
          a more precise mechanism for influencing the names that are
          available when the *note ForwardRef: 175d. is evaluated.
          'globals' and 'locals' are passed to *note eval(): 4a4,
          representing the global and local namespaces in which the name
          is evaluated.  The 'type_params' parameter is relevant for
          objects created using the native syntax for *note generic
          classes: 682. and *note functions: 683.  It is a tuple of
          *note type parameters: 5ad. that are in scope while the
          forward reference is being evaluated.  For example, if
          evaluating a *note ForwardRef: 175d. retrieved from an
          annotation found in the class namespace of a generic class
          ‘C’, 'type_params' should be set to ‘C.__type_params__’.

          *note ForwardRef: 175d. instances returned by *note
          get_annotations(): 459. retain references to information about
          the scope they originated from, so calling this method with no
          further arguments may be sufficient to evaluate such objects.
          *note ForwardRef: 175d. instances created by other means may
          not have any information about their scope, so passing
          arguments to this method may be necessary to evaluate them
          successfully.

          If no 'owner', 'globals', 'locals', or 'type_params' are
          provided and the *note ForwardRef: 175d. does not contain
          information about its origin, empty globals and locals
          dictionaries are used.

     Added in version 3.14.


File: python.info,  Node: Functions<11>,  Next: Recipes<3>,  Prev: Classes<4>,  Up: annotationlib — Functionality for introspecting annotations

5.29.15.3 Functions
...................

 -- Funzione: annotationlib.annotations_to_string (annotations)

     Convert an annotations dict containing runtime values to a dict
     containing only strings.  If the values are not already strings,
     they are converted using *note type_repr(): 183e.  This is meant as
     a helper for user-provided annotate functions that support the
     *note STRING: 160. format but do not have access to the code
     creating the annotations.

     For example, this is used to implement the *note STRING: 160. for
     *note typing.TypedDict: 332. classes created through the functional
     syntax:

          >>> from typing import TypedDict
          >>> Movie = TypedDict("movie", {"name": str, "year": int})
          >>> get_annotations(Movie, format=Format.STRING)
          {'name': 'str', 'year': 'int'}

     Added in version 3.14.

 -- Funzione: annotationlib.call_annotate_function (annotate, format, *,
          owner=None)

     Call the *note annotate function: 15d. 'annotate' with the given
     'format', a member of the *note Format: 230. enum, and return the
     annotations dictionary produced by the function.

     This helper function is required because annotate functions
     generated by the compiler for functions, classes, and modules only
     support the *note VALUE: 15e. format when called directly.  To
     support other formats, this function calls the annotate function in
     a special environment that allows it to produce annotations in the
     other formats.  This is a useful building block when implementing
     functionality that needs to partially evaluate annotations while a
     class is being constructed.

     'owner' is the object that owns the annotation function, usually a
     function, class, or module.  If provided, it is used in the *note
     FORWARDREF: 15f. format to produce a *note ForwardRef: 175d. object
     that carries more information.

     Vedi anche
     ..........

     PEP 649(1) contains an explanation of the implementation technique
     used by this function.

     Added in version 3.14.

 -- Funzione: annotationlib.call_evaluate_function (evaluate, format, *,
          owner=None)

     Call the *note evaluate function: 44d6. 'evaluate' with the given
     'format', a member of the *note Format: 230. enum, and return the
     value produced by the function.  This is similar to *note
     call_annotate_function(): 17a6, but the latter always returns a
     dictionary mapping strings to annotations, while this function
     returns a single value.

     This is intended for use with the evaluate functions generated for
     lazily evaluated elements related to type aliases and type
     parameters:

        * *note typing.TypeAliasType.evaluate_value(): 44ec, the value
          of type aliases

        * *note typing.TypeVar.evaluate_bound(): 44d5, the bound of type
          variables

        * *note typing.TypeVar.evaluate_constraints(): 44d9, the
          constraints of type variables

        * *note typing.TypeVar.evaluate_default(): 44db, the default
          value of type variables

        * *note typing.ParamSpec.evaluate_default(): 44e6, the default
          value of parameter specifications

        * *note typing.TypeVarTuple.evaluate_default(): 44df, the
          default value of type variable tuples

     'owner' is the object that owns the evaluate function, such as the
     type alias or type variable object.

     'format' can be used to control the format in which the value is
     returned:

          >>> type Alias = undefined
          >>> call_evaluate_function(Alias.evaluate_value, Format.VALUE)
          Traceback (most recent call last):
          ...
          NameError: name 'undefined' is not defined
          >>> call_evaluate_function(Alias.evaluate_value, Format.FORWARDREF)
          ForwardRef('undefined')
          >>> call_evaluate_function(Alias.evaluate_value, Format.STRING)
          'undefined'

     Added in version 3.14.

 -- Funzione: annotationlib.get_annotate_from_class_namespace
          (namespace)

     Retrieve the *note annotate function: 15d. from a class namespace
     dictionary 'namespace'.  Return ‘None’ if the namespace does not
     contain an annotate function.  This is primarily useful before the
     class has been fully created (e.g., in a metaclass); after the
     class exists, the annotate function can be retrieved with
     ‘cls.__annotate__’.  See *note below: 4a63. for an example using
     this function in a metaclass.

     Added in version 3.14.

 -- Funzione: annotationlib.get_annotations (obj, *, globals=None,
          locals=None, eval_str=False, format=Format.VALUE)

     Compute the annotations dict for an object.

     'obj' may be a callable, class, module, or other object with *note
     __annotate__: 196b. or *note __annotations__: 458. attributes.
     Passing any other object raises *note TypeError: 198.

     The 'format' parameter controls the format in which annotations are
     returned, and must be a member of the *note Format: 230. enum or
     its integer equivalent.  The different formats work as follows:

        * VALUE: ‘object.__annotations__’ is tried first; if that does
          not exist, the ‘object.__annotate__’ function is called if it
          exists.

        * FORWARDREF: If ‘object.__annotations__’ exists and can be
          evaluated successfully, it is used; otherwise, the
          ‘object.__annotate__’ function is called.  If it does not
          exist either, ‘object.__annotations__’ is tried again and any
          error from accessing it is re-raised.

             * When calling ‘object.__annotate__’ it is first called
               with *note FORWARDREF: 15f.  If this is not implemented,
               it will then check if *note VALUE_WITH_FAKE_GLOBALS:
               4a5f. is supported and use that in the fake globals
               environment.  If neither of these formats are supported,
               it will fall back to using *note VALUE: 15e.  If *note
               VALUE: 15e. fails, the error from this call will be
               raised.

        * STRING: If ‘object.__annotate__’ exists, it is called first;
          otherwise, ‘object.__annotations__’ is used and stringified
          using *note annotations_to_string(): 4a62.

             * When calling ‘object.__annotate__’ it is first called
               with *note STRING: 160.  If this is not implemented, it
               will then check if *note VALUE_WITH_FAKE_GLOBALS: 4a5f.
               is supported and use that in the fake globals
               environment.  If neither of these formats are supported,
               it will fall back to using *note VALUE: 15e. with the
               result converted using *note annotations_to_string():
               4a62.  If *note VALUE: 15e. fails, the error from this
               call will be raised.

     Returns a dict.  ‘get_annotations()’ returns a new dict every time
     it’s called; calling it twice on the same object will return two
     different but equivalent dicts.

     This function handles several details for you:

        * If 'eval_str' is true, values of type ‘str’ will be
          un-stringized using *note eval(): 4a4.  This is intended for
          use with stringized annotations (‘from __future__ import
          annotations’).  It is an error to set 'eval_str' to true with
          formats other than *note Format.VALUE: 15e.

        * If 'obj' doesn’t have an annotations dict, returns an empty
          dict.  (Functions and methods always have an annotations dict;
          classes, modules, and other types of callables may not.)

        * Ignores inherited annotations on classes, as well as
          annotations on metaclasses.  If a class doesn’t have its own
          annotations dict, returns an empty dict.

        * All accesses to object members and dict values are done using
          ‘getattr()’ and ‘dict.get()’ for safety.

     'eval_str' controls whether or not values of type ‘str’ are
     replaced with the result of calling *note eval(): 4a4. on those
     values:

        * If eval_str is true, *note eval(): 4a4. is called on values of
          type ‘str’.  (Note that ‘get_annotations()’ doesn’t catch
          exceptions; if *note eval(): 4a4. raises an exception, it will
          unwind the stack past the ‘get_annotations()’ call.)

        * If 'eval_str' is false (the default), values of type ‘str’ are
          unchanged.

     'globals' and 'locals' are passed in to *note eval(): 4a4.; see the
     documentation for *note eval(): 4a4. for more information.  If
     'globals' or 'locals' is ‘None’, this function may replace that
     value with a context-specific default, contingent on ‘type(obj)’:

        * If 'obj' is a module, 'globals' defaults to ‘obj.__dict__’.

        * If 'obj' is a class, 'globals' defaults to
          ‘sys.modules[obj.__module__].__dict__’ and 'locals' defaults
          to the 'obj' class namespace.

        * If 'obj' is a callable, 'globals' defaults to *note
          obj.__globals__: 14db, although if 'obj' is a wrapped function
          (using *note functools.update_wrapper(): 1224.) or a *note
          functools.partial: 217. object, it is unwrapped until a
          non-wrapped function is found.

     Calling ‘get_annotations()’ is best practice for accessing the
     annotations dict of any object.  See *note Annotations Best
     Practices: 9db. for more information on annotations best practices.

          >>> def f(a: int, b: str) -> float:
          ...     pass
          >>> get_annotations(f)
          {'a': <class 'int'>, 'b': <class 'str'>, 'return': <class 'float'>}

     Added in version 3.14.

 -- Funzione: annotationlib.type_repr (value)

     Convert an arbitrary Python value to a format suitable for use by
     the *note STRING: 160. format.  This calls *note repr(): 1c1. for
     most objects, but has special handling for some objects, such as
     type objects.

     This is meant as a helper for user-provided annotate functions that
     support the *note STRING: 160. format but do not have access to the
     code creating the annotations.  It can also be used to provide a
     user-friendly string representation for other objects that contain
     values that are commonly encountered in annotations.

     Added in version 3.14.

   ---------- Footnotes ----------

   (1) 
https://peps.python.org/pep-0649/#the-stringizer-and-the-fake-globals-environment


File: python.info,  Node: Recipes<3>,  Next: Limitations of the STRING format,  Prev: Functions<11>,  Up: annotationlib — Functionality for introspecting annotations

5.29.15.4 Recipes
.................

* Menu:

* Using annotations in a metaclass::


File: python.info,  Node: Using annotations in a metaclass,  Up: Recipes<3>

5.29.15.5 Using annotations in a metaclass
..........................................

A *note metaclass: 23a4. may want to inspect or even modify the
annotations in a class body during class creation.  Doing so requires
retrieving annotations from the class namespace dictionary.  For classes
created with ‘from __future__ import annotations’, the annotations will
be in the ‘__annotations__’ key of the dictionary.  For other classes
with annotations, *note get_annotate_from_class_namespace(): 45b. can be
used to get the annotate function, and *note call_annotate_function():
17a6. can be used to call it and retrieve the annotations.  Using the
*note FORWARDREF: 15f. format will usually be best, because this allows
the annotations to refer to names that cannot yet be resolved when the
class is created.

To modify the annotations, it is best to create a wrapper annotate
function that calls the original annotate function, makes any necessary
adjustments, and returns the result.

Below is an example of a metaclass that filters out all *note
typing.ClassVar: 56d. annotations from the class and puts them in a
separate attribute:

     import annotationlib
     import typing

     class ClassVarSeparator(type):
        def __new__(mcls, name, bases, ns):
           if "__annotations__" in ns:  # from __future__ import annotations
              annotations = ns["__annotations__"]
              classvar_keys = {
                 key for key, value in annotations.items()
                 # Use string comparison for simplicity; a more robust solution
                 # could use annotationlib.ForwardRef.evaluate
                 if value.startswith("ClassVar")
              }
              classvars = {key: annotations[key] for key in classvar_keys}
              ns["__annotations__"] = {
                 key: value for key, value in annotations.items()
                 if key not in classvar_keys
              }
              wrapped_annotate = None
           elif annotate := annotationlib.get_annotate_from_class_namespace(ns):
              annotations = annotationlib.call_annotate_function(
                 annotate, format=annotationlib.Format.FORWARDREF
              )
              classvar_keys = {
                 key for key, value in annotations.items()
                 if typing.get_origin(value) is typing.ClassVar
              }
              classvars = {key: annotations[key] for key in classvar_keys}

              def wrapped_annotate(format):
                 annos = annotationlib.call_annotate_function(annotate, format, owner=typ)
                 return {key: value for key, value in annos.items() if key not in classvar_keys}

           else:  # no annotations
              classvars = {}
              wrapped_annotate = None
           typ = super().__new__(mcls, name, bases, ns)

           if wrapped_annotate is not None:
              # Wrap the original __annotate__ with a wrapper that removes ClassVars
              typ.__annotate__ = wrapped_annotate
           typ.classvars = classvars  # Store the ClassVars in a separate attribute
           return typ


File: python.info,  Node: Limitations of the STRING format,  Next: Limitations of the FORWARDREF format,  Prev: Recipes<3>,  Up: annotationlib — Functionality for introspecting annotations

5.29.15.6 Limitations of the ‘STRING’ format
............................................

The *note STRING: 160. format is meant to approximate the source code of
the annotation, but the implementation strategy used means that it is
not always possible to recover the exact source code.

First, the stringifier of course cannot recover any information that is
not present in the compiled code, including comments, whitespace,
parenthesization, and operations that get simplified by the compiler.

Second, the stringifier can intercept almost all operations that involve
names looked up in some scope, but it cannot intercept operations that
operate fully on constants.  As a corollary, this also means it is not
safe to request the ‘STRING’ format on untrusted code: Python is
powerful enough that it is possible to achieve arbitrary code execution
even with no access to any globals or builtins.  For example:

     >>> def f(x: (1).__class__.__base__.__subclasses__()[-1].__init__.__builtins__["print"]("Hello world")): pass
     ...
     >>> annotationlib.get_annotations(f, format=annotationlib.Format.STRING)
     Hello world
     {'x': 'None'}

     Nota: This particular example works as of the time of writing, but
     it relies on implementation details and is not guaranteed to work
     in the future.

Among the different kinds of expressions that exist in Python, as
represented by the *note ast: 9. module, some expressions are supported,
meaning that the ‘STRING’ format can generally recover the original
source code; others are unsupported, meaning that they may result in
incorrect output or an error.

The following are supported (sometimes with caveats):

   * *note ast.BinOp: 1d9a.

   * *note ast.UnaryOp: 4a67.

        * *note ast.Invert: 4a68. (‘~’), *note ast.UAdd: 4a69. (‘+’),
          and *note ast.USub: 4a6a. (‘-’) are supported

        * *note ast.Not: 4a6b. (‘not’) is not supported

   * *note ast.Dict: 1d31. (except when using ‘**’ unpacking)

   * *note ast.Set: 4a6c.

   * *note ast.Compare: 4a6d.

        * *note ast.Eq: 4a6e. and *note ast.NotEq: 4a6f. are supported

        * *note ast.Lt: 4a70, *note ast.LtE: 4a71, *note ast.Gt: 4a72,
          and *note ast.GtE: 4a73. are supported, but the operand may be
          flipped

        * *note ast.Is: 4a74, *note ast.IsNot: 4a75, *note ast.In: 4a76,
          and *note ast.NotIn: 4a77. are not supported

   * *note ast.Call: 4a78. (except when using ‘**’ unpacking)

   * *note ast.Constant: 2ef. (though not the exact representation of
     the constant; for example, escape sequences in strings are lost;
     hexadecimal numbers are converted to decimal)

   * *note ast.Attribute: 4a79. (assuming the value is not a constant)

   * *note ast.Subscript: 4a7a. (assuming the value is not a constant)

   * *note ast.Starred: 4a7b. (‘*’ unpacking)

   * *note ast.Name: 1d0a.

   * *note ast.List: 4a7c.

   * *note ast.Tuple: 4a7d.

   * *note ast.Slice: 4a7e.

The following are unsupported, but throw an informative error when
encountered by the stringifier:

   * *note ast.FormattedValue: 4a7f. (f-strings; error is not detected
     if conversion specifiers like ‘!r’ are used)

   * *note ast.JoinedStr: 1a44. (f-strings)

The following are unsupported and result in incorrect output:

   * *note ast.BoolOp: 4a80. (‘and’ and ‘or’)

   * *note ast.IfExp: 4a81.

   * *note ast.Lambda: 4a82.

   * *note ast.ListComp: 4a83.

   * *note ast.SetComp: 4a84.

   * *note ast.DictComp: 4a85.

   * *note ast.GeneratorExp: 4a86.

The following are disallowed in annotation scopes and therefore not
relevant:

   * *note ast.NamedExpr: 4a87. (‘:=’)

   * *note ast.Await: 4a88.

   * *note ast.Yield: 4a89.

   * *note ast.YieldFrom: 4a8a.


File: python.info,  Node: Limitations of the FORWARDREF format,  Next: Security implications of introspecting annotations,  Prev: Limitations of the STRING format,  Up: annotationlib — Functionality for introspecting annotations

5.29.15.7 Limitations of the ‘FORWARDREF’ format
................................................

The *note FORWARDREF: 15f. format aims to produce real values as much as
possible, with anything that cannot be resolved replaced with *note
ForwardRef: 175d. objects.  It is affected by broadly the same
Limitations as the *note STRING: 160. format: annotations that perform
operations on literals or that use unsupported expression types may
raise exceptions when evaluated using the *note FORWARDREF: 15f. format.

Below are a few examples of the behavior with unsupported expressions:

     >>> from annotationlib import get_annotations, Format
     >>> def zerodiv(x: 1 / 0): ...
     >>> get_annotations(zerodiv, format=Format.STRING)
     Traceback (most recent call last):
       ...
     ZeroDivisionError: division by zero
     >>> get_annotations(zerodiv, format=Format.FORWARDREF)
     Traceback (most recent call last):
       ...
     ZeroDivisionError: division by zero
     >>> def ifexp(x: 1 if y else 0): ...
     >>> get_annotations(ifexp, format=Format.STRING)
     {'x': '1'}


File: python.info,  Node: Security implications of introspecting annotations,  Prev: Limitations of the FORWARDREF format,  Up: annotationlib — Functionality for introspecting annotations

5.29.15.8 Security implications of introspecting annotations
............................................................

Much of the functionality in this module involves executing code related
to annotations, which can then do arbitrary things.  For example, *note
get_annotations(): 459. may call an arbitrary *note annotate function:
15d, and *note ForwardRef.evaluate(): 179a. may call *note eval(): 4a4.
on an arbitrary string.  Code contained in an annotation might make
arbitrary system calls, enter an infinite loop, or perform any other
operation.  This is also true for any access of the *note
__annotations__: 458. attribute, and for various functions in the *note
typing: 10a. module that work with annotations, such as *note
typing.get_type_hints(): 8c1.

Any security issue arising from this also applies immediately after
importing code that may contain untrusted annotations: importing code
can always cause arbitrary operations to be performed.  However, it is
unsafe to accept strings or other input from an untrusted source and
pass them to any of the APIs for introspecting annotations, for example
by editing an ‘__annotations__’ dictionary or directly creating a *note
ForwardRef: 175d. object.


File: python.info,  Node: site — Site-specific configuration hook,  Prev: annotationlib — Functionality for introspecting annotations,  Up: Python Runtime Services

5.29.16 ‘site’ — Site-specific configuration hook
-------------------------------------------------

'Source code:' Lib/site.py(1)

__________________________________________________________________

'This module is automatically imported during initialization.'  The
automatic import can be suppressed using the interpreter’s *note -S:
13b0. option.

Importing this module normally appends site-specific paths to the module
search path and adds *note callables: 25c4, including *note help(): ad6.
to the built-in namespace.  However, Python startup option *note -S:
13b0. blocks this and this module can be safely imported with no
automatic modifications to the module search path or additions to the
builtins.  To explicitly trigger the usual site-specific additions, call
the *note main(): 2110. function.

Cambiato nella versione 3.3: Importing the module used to trigger paths
manipulation even when using *note -S: 13b0.

It starts by constructing up to four directories from a head and a tail
part.  For the head part, it uses ‘sys.prefix’ and ‘sys.exec_prefix’;
empty heads are skipped.  For the tail part, it uses the empty string
and then ‘lib/site-packages’ (on Windows) or
‘lib/python`X.Y[t]'/site-packages’ (on Unix and macOS). (The optional
suffix «t» indicates the *note free threading: 1f4. build, and is
appended if ‘"t"’ is present in the *note sys.abiflags: c5b. constant.)
For each of the distinct head-tail combinations, it sees if it refers to
an existing directory, and if so, adds it to ‘sys.path’ and also
inspects the newly added path for configuration files.

Cambiato nella versione 3.5: Support for the «site-python» directory has
been removed.

Cambiato nella versione 3.13: On Unix, *note Free threading: 1f4. Python
installations are identified by the «t» suffix in the version-specific
directory name, such as ‘lib/python3.13t/’.

Cambiato nella versione 3.14: *note site: cc. is no longer responsible
for updating *note sys.prefix: 3e7. and *note sys.exec_prefix: 3eb. on
*note Virtual Environments: 489b.  This is now done during the *note
path initialization: 18c4.  As a result, under *note Virtual
Environments: 489b, *note sys.prefix: 3e7. and *note sys.exec_prefix:
3eb. no longer depend on the *note site: cc. initialization, and are
therefore unaffected by *note -S: 13b0.

When running under a *note virtual environment: 489b, the ‘pyvenv.cfg’
file in *note sys.prefix: 3e7. is checked for site-specific
configurations.  If the ‘include-system-site-packages’ key exists and is
set to ‘true’ (case-insensitive), the system-level prefixes will be
searched for site-packages, otherwise they won’t.

A path configuration file is a file whose name has the form ‘`name'.pth’
and exists in one of the four directories mentioned above; its contents
are additional items (one per line) to be added to ‘sys.path’.
Non-existing items are never added to ‘sys.path’, and no check is made
that the item refers to a directory rather than a file.  No item is
added to ‘sys.path’ more than once.  Blank lines and lines beginning
with ‘#’ are skipped.  Lines starting with ‘import’ (followed by space
or tab) are executed.

     Nota: An executable line in a ‘.pth’ file is run at every Python
     startup, regardless of whether a particular module is actually
     going to be used.  Its impact should thus be kept to a minimum.
     The primary intended purpose of executable lines is to make the
     corresponding module(s) importable (load 3rd-party import hooks,
     adjust ‘PATH’ etc).  Any other initialization is supposed to be
     done upon a module’s actual import, if and when it happens.
     Limiting a code chunk to a single line is a deliberate measure to
     discourage putting anything more complex here.

Cambiato nella versione 3.13: The ‘.pth’ files are now decoded by UTF-8
at first and then by the *note locale encoding: 54b. if it fails.

For example, suppose ‘sys.prefix’ and ‘sys.exec_prefix’ are set to
‘/usr/local’.  The Python X.Y library is then installed in
‘/usr/local/lib/python`X.Y'’.  Suppose this has a subdirectory
‘/usr/local/lib/python`X.Y'/site-packages’ with three subsubdirectories,
‘foo’, ‘bar’ and ‘spam’, and two path configuration files, ‘foo.pth’ and
‘bar.pth’.  Assume ‘foo.pth’ contains the following:

     # foo package configuration

     foo
     bar
     bletch

and ‘bar.pth’ contains:

     # bar package configuration

     bar

Then the following version-specific directories are added to ‘sys.path’,
in this order:

     /usr/local/lib/pythonX.Y/site-packages/bar
     /usr/local/lib/pythonX.Y/site-packages/foo

Note that ‘bletch’ is omitted because it doesn’t exist; the ‘bar’
directory precedes the ‘foo’ directory because ‘bar.pth’ comes
alphabetically before ‘foo.pth’; and ‘spam’ is omitted because it is not
mentioned in either path configuration file.

* Menu:

* sitecustomize::
* usercustomize::
* Readline configuration::
* Module contents: Module contents<5>.
* Command-line interface: Command-line interface<11>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/site.py


File: python.info,  Node: sitecustomize,  Next: usercustomize,  Up: site — Site-specific configuration hook

5.29.16.1 ‘sitecustomize’
.........................

After these path manipulations, an attempt is made to import a module
named *note sitecustomize: cd, which can perform arbitrary site-specific
customizations.  It is typically created by a system administrator in
the site-packages directory.  If this import fails with an *note
ImportError: 65b. or its subclass exception, and the exception’s *note
name: 26cd. attribute equals to ‘'sitecustomize'’, it is silently
ignored.  If Python is started without output streams available, as with
‘pythonw.exe’ on Windows (which is used by default to start IDLE),
attempted output from *note sitecustomize: cd. is ignored.  Any other
exception causes a silent and perhaps mysterious failure of the process.


File: python.info,  Node: usercustomize,  Next: Readline configuration,  Prev: sitecustomize,  Up: site — Site-specific configuration hook

5.29.16.2 ‘usercustomize’
.........................

After this, an attempt is made to import a module named *note
usercustomize: 114, which can perform arbitrary user-specific
customizations, if *note ENABLE_USER_SITE: 4a92. is true.  This file is
intended to be created in the user site-packages directory (see below),
which is part of ‘sys.path’ unless disabled by *note -s: 1596.  If this
import fails with an *note ImportError: 65b. or its subclass exception,
and the exception’s *note name: 26cd. attribute equals to
‘'usercustomize'’, it is silently ignored.

Note that for some non-Unix systems, ‘sys.prefix’ and ‘sys.exec_prefix’
are empty, and the path manipulations are skipped; however the import of
*note sitecustomize: cd. and *note usercustomize: 114. is still
attempted.


File: python.info,  Node: Readline configuration,  Next: Module contents<5>,  Prev: usercustomize,  Up: site — Site-specific configuration hook

5.29.16.3 Readline configuration
................................

On systems that support *note readline: bf, this module will also import
and configure the *note rlcompleter: c2. module, if Python is started in
*note interactive mode: 443. and without the *note -S: 13b0. option.
The default behavior is enable tab-completion and to use
‘~/.python_history’ as the history save file.  To disable it, delete (or
override) the *note sys.__interactivehook__: 11ca. attribute in your
*note sitecustomize: cd. or *note usercustomize: 114. module or your
*note PYTHONSTARTUP: 1b8. file.

Cambiato nella versione 3.4: Activation of rlcompleter and history was
made automatic.


File: python.info,  Node: Module contents<5>,  Next: Command-line interface<11>,  Prev: Readline configuration,  Up: site — Site-specific configuration hook

5.29.16.4 Module contents
.........................

 -- Dati: site.PREFIXES

     A list of prefixes for site-packages directories.

 -- Dati: site.ENABLE_USER_SITE

     Flag showing the status of the user site-packages directory.
     ‘True’ means that it is enabled and was added to ‘sys.path’.
     ‘False’ means that it was disabled by user request (with *note -s:
     1596. or *note PYTHONNOUSERSITE: 1597.).  ‘None’ means it was
     disabled for security reasons (mismatch between user or group id
     and effective id) or by an administrator.

 -- Dati: site.USER_SITE

     Path to the user site-packages for the running Python.  Can be
     ‘None’ if *note getusersitepackages(): 1448. hasn’t been called
     yet.  Default value is ‘~/.local/lib/python`X.Y'[t]/site-packages’
     for UNIX and non-framework macOS builds,
     ‘~/Library/Python/`X.Y'/lib/python/site-packages’ for macOS
     framework builds, and ‘`%APPDATA%'\Python\Python`XY'\site-packages’
     on Windows.  The optional «t» indicates the free-threaded build.
     This directory is a site directory, which means that ‘.pth’ files
     in it will be processed.

 -- Dati: site.USER_BASE

     Path to the base directory for the user site-packages.  Can be
     ‘None’ if *note getuserbase(): 1447. hasn’t been called yet.
     Default value is ‘~/.local’ for UNIX and macOS non-framework
     builds, ‘~/Library/Python/`X.Y'’ for macOS framework builds, and
     ‘`%APPDATA%'\Python’ for Windows.  This value is used to compute
     the installation directories for scripts, data files, Python
     modules, etc.  for the *note user installation scheme: 2120.  See
     also *note PYTHONUSERBASE: 1595.

 -- Funzione: site.main ()

     Adds all the standard site-specific directories to the module
     search path.  This function is called automatically when this
     module is imported, unless the Python interpreter was started with
     the *note -S: 13b0. flag.

     Cambiato nella versione 3.3: This function used to be called
     unconditionally.

 -- Funzione: site.addsitedir (sitedir, known_paths=None)

     Add a directory to sys.path and process its ‘.pth’ files.
     Typically used in *note sitecustomize: cd. or *note usercustomize:
     114. (see above).

 -- Funzione: site.getsitepackages ()

     Return a list containing all global site-packages directories.

     Added in version 3.2.

 -- Funzione: site.getuserbase ()

     Return the path of the user base directory, *note USER_BASE: 1524.
     If it is not initialized yet, this function will also set it,
     respecting *note PYTHONUSERBASE: 1595.

     Added in version 3.2.

 -- Funzione: site.getusersitepackages ()

     Return the path of the user-specific site-packages directory, *note
     USER_SITE: 210f.  If it is not initialized yet, this function will
     also set it, respecting *note USER_BASE: 1524.  To determine if the
     user-specific site-packages was added to ‘sys.path’ *note
     ENABLE_USER_SITE: 4a92. should be used.

     Added in version 3.2.


File: python.info,  Node: Command-line interface<11>,  Prev: Module contents<5>,  Up: site — Site-specific configuration hook

5.29.16.5 Command-line interface
................................

The *note site: cc. module also provides a way to get the user
directories from the command line:

     $ python -m site --user-site
     /home/user/.local/lib/python3.11/site-packages

If it is called without arguments, it will print the contents of *note
sys.path: 3e4. on the standard output, followed by the value of *note
USER_BASE: 1524. and whether the directory exists, then the same thing
for *note USER_SITE: 210f, and finally the value of *note
ENABLE_USER_SITE: 4a92.

 -- Option: --user-base

     Print the path to the user base directory.

 -- Option: --user-site

     Print the path to the user site-packages directory.

If both options are given, user base and user site will be printed
(always in this order), separated by *note os.pathsep: 211d.

If any option is given, the script will exit with one of these values:
‘0’ if the user site-packages directory is enabled, ‘1’ if it was
disabled by the user, ‘2’ if it is disabled for security reasons or by
an administrator, and a value greater than 2 if there is an error.

Vedi anche
..........

   * PEP 370(1) – Per user site-packages directory

   * *note The initialization of the sys.path module search path: 18c4.
     – The initialization of *note sys.path: 3e4.

Vedi anche
..........

   * See the *note concurrent.interpreters: 25. module, which similarly
     exposes core runtime functionality.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0370/


File: python.info,  Node: Custom Python Interpreters,  Next: Importing Modules,  Prev: Python Runtime Services,  Up: The Python Standard Library

5.30 Custom Python Interpreters
===============================

The modules described in this chapter allow writing interfaces similar
to Python’s interactive interpreter.  If you want a Python interpreter
that supports some special feature in addition to the Python language,
you should look at the *note code: 1b. module.  (The *note codeop: 1d.
module is lower-level, used to support compiling a possibly incomplete
chunk of Python code.)

The full list of modules described in this chapter is:

* Menu:

* code — Interpreter base classes::
* codeop — Compile Python code::


File: python.info,  Node: code — Interpreter base classes,  Next: codeop — Compile Python code,  Up: Custom Python Interpreters

5.30.1 ‘code’ — Interpreter base classes
----------------------------------------

'Source code:' Lib/code.py(1)

__________________________________________________________________

The ‘code’ module provides facilities to implement read-eval-print loops
in Python.  Two classes and convenience functions are included which can
be used to build applications which provide an interactive interpreter
prompt.

 -- Classe: code.InteractiveInterpreter (locals=None)

     This class deals with parsing and interpreter state (the user’s
     namespace); it does not deal with input buffering or prompting or
     input file naming (the filename is always passed in explicitly).
     The optional 'locals' argument specifies a mapping to use as the
     namespace in which code will be executed; it defaults to a newly
     created dictionary with key ‘'__name__'’ set to ‘'__console__'’ and
     key ‘'__doc__'’ set to ‘None’.

     Note that functions and classes objects created under an
     ‘InteractiveInterpreter’ instance will belong to the namespace
     specified by 'locals'.  They are only pickleable if 'locals' is the
     namespace of an existing module.

 -- Classe: code.InteractiveConsole (locals=None, filename='<console>',
          local_exit=False)

     Closely emulate the behavior of the interactive Python interpreter.
     This class builds on *note InteractiveInterpreter: 192b. and adds
     prompting using the familiar ‘sys.ps1’ and ‘sys.ps2’, and input
     buffering.  If 'local_exit' is true, ‘exit()’ and ‘quit()’ in the
     console will not raise *note SystemExit: f3e, but instead return to
     the calling code.

     Cambiato nella versione 3.13: Added 'local_exit' parameter.

 -- Funzione: code.interact (banner=None, readfunc=None, local=None,
          exitmsg=None, local_exit=False)

     Convenience function to run a read-eval-print loop.  This creates a
     new instance of *note InteractiveConsole: 27ea. and sets 'readfunc'
     to be used as the *note InteractiveConsole.raw_input(): 4aa0.
     method, if provided.  If 'local' is provided, it is passed to the
     *note InteractiveConsole: 27ea. constructor for use as the default
     namespace for the interpreter loop.  If 'local_exit' is provided,
     it is passed to the *note InteractiveConsole: 27ea. constructor.
     The *note interact(): 4aa1. method of the instance is then run with
     'banner' and 'exitmsg' passed as the banner and exit message to
     use, if provided.  The console object is discarded after use.

     Cambiato nella versione 3.6: Added 'exitmsg' parameter.

     Cambiato nella versione 3.13: Added 'local_exit' parameter.

 -- Funzione: code.compile_command (source, filename='<input>',
          symbol='single')

     This function is useful for programs that want to emulate Python’s
     interpreter main loop (a.k.a.  the read-eval-print loop).  The
     tricky part is to determine when the user has entered an incomplete
     command that can be completed by entering more text (as opposed to
     a complete command or a syntax error).  This function 'almost'
     always makes the same decision as the real interpreter main loop.

     'source' is the source string; 'filename' is the optional filename
     from which source was read, defaulting to ‘'<input>'’; and 'symbol'
     is the optional grammar start symbol, which should be ‘'single'’
     (the default), ‘'eval'’ or ‘'exec'’.

     Returns a code object (the same as ‘compile(source, filename,
     symbol)’) if the command is complete and valid; ‘None’ if the
     command is incomplete; raises *note SyntaxError: 18e. if the
     command is complete and contains a syntax error, or raises *note
     OverflowError: a83. or *note ValueError: 2ec. if the command
     contains an invalid literal.

* Menu:

* Interactive Interpreter Objects::
* Interactive Console Objects::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/code.py


File: python.info,  Node: Interactive Interpreter Objects,  Next: Interactive Console Objects,  Up: code — Interpreter base classes

5.30.1.1 Interactive Interpreter Objects
........................................

 -- Metodo: InteractiveInterpreter.runsource (source,
          filename='<input>', symbol='single')

     Compile and run some source in the interpreter.  Arguments are the
     same as for *note compile_command(): 4aa2.; the default for
     'filename' is ‘'<input>'’, and for 'symbol' is ‘'single'’.  One of
     several things can happen:

        * The input is incorrect; *note compile_command(): 4aa2. raised
          an exception (*note SyntaxError: 18e. or *note OverflowError:
          a83.).  A syntax traceback will be printed by calling the
          *note showsyntaxerror(): 4aa6. method.  *note runsource():
          4aa5. returns ‘False’.

        * The input is incomplete, and more input is required; *note
          compile_command(): 4aa2. returned ‘None’.  *note runsource():
          4aa5. returns ‘True’.

        * The input is complete; *note compile_command(): 4aa2. returned
          a code object.  The code is executed by calling the *note
          runcode(): 4aa7. (which also handles run-time exceptions,
          except for *note SystemExit: f3e.).  *note runsource(): 4aa5.
          returns ‘False’.

     The return value can be used to decide whether to use ‘sys.ps1’ or
     ‘sys.ps2’ to prompt the next line.

 -- Metodo: InteractiveInterpreter.runcode (code)

     Execute a code object.  When an exception occurs, *note
     showtraceback(): fd0. is called to display a traceback.  All
     exceptions are caught except *note SystemExit: f3e, which is
     allowed to propagate.

     A note about *note KeyboardInterrupt: bc7.: this exception may
     occur elsewhere in this code, and may not always be caught.  The
     caller should be prepared to deal with it.

 -- Metodo: InteractiveInterpreter.showsyntaxerror (filename=None)

     Display the syntax error that just occurred.  This does not display
     a stack trace because there isn’t one for syntax errors.  If
     'filename' is given, it is stuffed into the exception instead of
     the default filename provided by Python’s parser, because it always
     uses ‘'<string>'’ when reading from a string.  The output is
     written by the *note write(): 4aa8. method.

 -- Metodo: InteractiveInterpreter.showtraceback ()

     Display the exception that just occurred.  We remove the first
     stack item because it is within the interpreter object
     implementation.  The output is written by the *note write(): 4aa8.
     method.

     Cambiato nella versione 3.5: The full chained traceback is
     displayed instead of just the primary traceback.

 -- Metodo: InteractiveInterpreter.write (data)

     Write a string to the standard error stream (‘sys.stderr’).
     Derived classes should override this to provide the appropriate
     output handling as needed.


File: python.info,  Node: Interactive Console Objects,  Prev: Interactive Interpreter Objects,  Up: code — Interpreter base classes

5.30.1.2 Interactive Console Objects
....................................

The *note InteractiveConsole: 27ea. class is a subclass of *note
InteractiveInterpreter: 192b, and so offers all the methods of the
interpreter objects as well as the following additions.

 -- Metodo: InteractiveConsole.interact (banner=None, exitmsg=None)

     Closely emulate the interactive Python console.  The optional
     'banner' argument specify the banner to print before the first
     interaction; by default it prints a banner similar to the one
     printed by the standard Python interpreter, followed by the class
     name of the console object in parentheses (so as not to confuse
     this with the real interpreter – since it’s so close!).

     The optional 'exitmsg' argument specifies an exit message printed
     when exiting.  Pass the empty string to suppress the exit message.
     If 'exitmsg' is not given or ‘None’, a default message is printed.

     Cambiato nella versione 3.4: To suppress printing any banner, pass
     an empty string.

     Cambiato nella versione 3.6: Print an exit message when exiting.

 -- Metodo: InteractiveConsole.push (line)

     Push a line of source text to the interpreter.  The line should not
     have a trailing newline; it may have internal newlines.  The line
     is appended to a buffer and the interpreter’s *note runsource():
     4aa5. method is called with the concatenated contents of the buffer
     as source.  If this indicates that the command was executed or
     invalid, the buffer is reset; otherwise, the command is incomplete,
     and the buffer is left as it was after the line was appended.  The
     return value is ‘True’ if more input is required, ‘False’ if the
     line was dealt with in some way (this is the same as
     ‘runsource()’).

 -- Metodo: InteractiveConsole.resetbuffer ()

     Remove any unhandled source text from the input buffer.

 -- Metodo: InteractiveConsole.raw_input (prompt='')

     Write a prompt and read a line.  The returned line does not include
     the trailing newline.  When the user enters the EOF key sequence,
     *note EOFError: 14e1. is raised.  The base implementation reads
     from ‘sys.stdin’; a subclass may replace this with a different
     implementation.


File: python.info,  Node: codeop — Compile Python code,  Prev: code — Interpreter base classes,  Up: Custom Python Interpreters

5.30.2 ‘codeop’ — Compile Python code
-------------------------------------

'Source code:' Lib/codeop.py(1)

__________________________________________________________________

The *note codeop: 1d. module provides utilities upon which the Python
read-eval-print loop can be emulated, as is done in the *note code: 1b.
module.  As a result, you probably don’t want to use the module
directly; if you want to include such a loop in your program you
probably want to use the *note code: 1b. module instead.

There are two parts to this job:

  1. Being able to tell if a line of input completes a Python statement:
     in short, telling whether to print “‘>>>’” or “‘...’” next.

  2. Remembering which future statements the user has entered, so
     subsequent input can be compiled with these in effect.

The *note codeop: 1d. module provides a way of doing each of these
things, and a way of doing them both.

To do just the former:

 -- Funzione: codeop.compile_command (source, filename='<input>',
          symbol='single')

     Tries to compile 'source', which should be a string of Python code
     and return a code object if 'source' is valid Python code.  In that
     case, the filename attribute of the code object will be 'filename',
     which defaults to ‘'<input>'’.  Returns ‘None’ if 'source' is 'not'
     valid Python code, but is a prefix of valid Python code.

     If there is a problem with 'source', an exception will be raised.
     *note SyntaxError: 18e. is raised if there is invalid Python
     syntax, and *note OverflowError: a83. or *note ValueError: 2ec. if
     there is an invalid literal.

     The 'symbol' argument determines whether 'source' is compiled as a
     statement (‘'single'’, the default), as a sequence of *note
     statement: 2be2. (‘'exec'’) or as an *note expression: 23b5.
     (‘'eval'’).  Any other value will cause *note ValueError: 2ec. to
     be raised.

          Nota: It is possible (but not likely) that the parser stops
          parsing with a successful outcome before reaching the end of
          the source; in this case, trailing symbols may be ignored
          instead of causing an error.  For example, a backslash
          followed by two newlines may be followed by arbitrary garbage.
          This will be fixed once the API for the parser is better.

 -- Classe: codeop.Compile

     Instances of this class have *note __call__(): 77b. methods
     identical in signature to the built-in function *note compile():
     4b2, but with the difference that if the instance compiles program
     text containing a *note __future__: 0. statement, the instance
     “remembers” and compiles all subsequent program texts with the
     statement in force.

 -- Classe: codeop.CommandCompiler

     Instances of this class have *note __call__(): 77b. methods
     identical in signature to *note compile_command(): 1b3b.; the
     difference is that if the instance compiles program text containing
     a *note __future__: 0. statement, the instance “remembers” and
     compiles all subsequent program texts with the statement in force.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/codeop.py


File: python.info,  Node: Importing Modules,  Next: Python Language Services,  Prev: Custom Python Interpreters,  Up: The Python Standard Library

5.31 Importing Modules
======================

The modules described in this chapter provide new ways to import other
Python modules and hooks for customizing the import process.

The full list of modules described in this chapter is:

* Menu:

* zipimport — Import modules from Zip archives::
* pkgutil — Package extension utility::
* modulefinder — Find modules used by a script::
* runpy — Locating and executing Python modules::
* importlib — The implementation of import::
* importlib.resources – Package resource reading, opening and access: importlib resources – Package resource reading opening and access.
* importlib.resources.abc – Abstract base classes for resources: importlib resources abc – Abstract base classes for resources.
* importlib.metadata – Accessing package metadata: importlib metadata – Accessing package metadata.
* The initialization of the sys.path module search path: The initialization of the sys path module search path.


File: python.info,  Node: zipimport — Import modules from Zip archives,  Next: pkgutil — Package extension utility,  Up: Importing Modules

5.31.1 ‘zipimport’ — Import modules from Zip archives
-----------------------------------------------------

'Source code:' Lib/zipimport.py(1)

__________________________________________________________________

This module adds the ability to import Python modules (‘*.py’, ‘*.pyc’)
and packages from ZIP-format archives.  It is usually not needed to use
the *note zipimport: 138. module explicitly; it is automatically used by
the built-in *note import: 7f9. mechanism for *note sys.path: 3e4. items
that are paths to ZIP archives.

Typically, *note sys.path: 3e4. is a list of directory names as strings.
This module also allows an item of *note sys.path: 3e4. to be a string
naming a ZIP file archive.  The ZIP archive can contain a subdirectory
structure to support package imports, and a path within the archive can
be specified to only import from a subdirectory.  For example, the path
‘example.zip/lib/’ would only import from the ‘lib/’ subdirectory within
the archive.

Any files may be present in the ZIP archive, but importers are only
invoked for ‘.py’ and ‘.pyc’ files.  ZIP import of dynamic modules
(‘.pyd’, ‘.so’) is disallowed.  Note that if an archive only contains
‘.py’ files, Python will not attempt to modify the archive by adding the
corresponding ‘.pyc’ file, meaning that if a ZIP archive doesn’t contain
‘.pyc’ files, importing may be rather slow.

Cambiato nella versione 3.13: ZIP64 is supported

Cambiato nella versione 3.8: Previously, ZIP archives with an archive
comment were not supported.

Vedi anche
..........

PKZIP Application Note(2)

     Documentation on the ZIP file format by Phil Katz, the creator of
     the format and algorithms used.

PEP 273(3) - Import Modules from Zip Archives

     Written by James C. Ahlstrom, who also provided an implementation.
     Python 2.3 follows the specification in PEP 273(4), but uses an
     implementation written by Just van Rossum that uses the import
     hooks described in PEP 302(5).

*note importlib: 7b. - The implementation of the import machinery

     Package providing the relevant protocols for all importers to
     implement.

This module defines an exception:

 -- Eccezione: zipimport.ZipImportError

     Exception raised by zipimporter objects.  It’s a subclass of *note
     ImportError: 65b, so it can be caught as *note ImportError: 65b,
     too.

* Menu:

* zipimporter Objects::
* Examples: Examples<34>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/zipimport.py

   (2) https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT

   (3) https://peps.python.org/pep-0273/

   (4) https://peps.python.org/pep-0273/

   (5) https://peps.python.org/pep-0302/


File: python.info,  Node: zipimporter Objects,  Next: Examples<34>,  Up: zipimport — Import modules from Zip archives

5.31.1.1 zipimporter Objects
............................

*note zipimporter: 4abb. is the class for importing ZIP files.

 -- Classe: zipimport.zipimporter (archivepath)

     Create a new zipimporter instance.  'archivepath' must be a path to
     a ZIP file, or to a specific path within a ZIP file.  For example,
     an 'archivepath' of ‘foo/bar.zip/lib’ will look for modules in the
     ‘lib’ directory inside the ZIP file ‘foo/bar.zip’ (provided that it
     exists).

     *note ZipImportError: 4ab8. is raised if 'archivepath' doesn’t
     point to a valid ZIP archive.

     Cambiato nella versione 3.12: Methods ‘find_loader()’ and
     ‘find_module()’, deprecated in 3.10 are now removed.  Use *note
     find_spec(): a60. instead.

      -- Metodo: create_module (spec)

          Implementation of *note importlib.abc.Loader.create_module():
          eae. that returns *note None: 886. to explicitly request the
          default semantics.

          Added in version 3.10.

      -- Metodo: exec_module (module)

          Implementation of *note importlib.abc.Loader.exec_module():
          a6c.

          Added in version 3.10.

      -- Metodo: find_spec (fullname, target=None)

          An implementation of *note
          importlib.abc.PathEntryFinder.find_spec(): a6e.

          Added in version 3.10.

      -- Metodo: get_code (fullname)

          Return the code object for the specified module.  Raise *note
          ZipImportError: 4ab8. if the module couldn’t be imported.

      -- Metodo: get_data (pathname)

          Return the data associated with 'pathname'.  Raise *note
          OSError: 2c0. if the file wasn’t found.

          Cambiato nella versione 3.3: *note IOError: 1255. used to be
          raised, it is now an alias of *note OSError: 2c0.

      -- Metodo: get_filename (fullname)

          Return the value ‘__file__’ would be set to if the specified
          module was imported.  Raise *note ZipImportError: 4ab8. if the
          module couldn’t be imported.

          Added in version 3.1.

      -- Metodo: get_source (fullname)

          Return the source code for the specified module.  Raise *note
          ZipImportError: 4ab8. if the module couldn’t be found, return
          *note None: 886. if the archive does contain the module, but
          has no source for it.

      -- Metodo: is_package (fullname)

          Return ‘True’ if the module specified by 'fullname' is a
          package.  Raise *note ZipImportError: 4ab8. if the module
          couldn’t be found.

      -- Metodo: load_module (fullname)

          Load the module specified by 'fullname'.  'fullname' must be
          the fully qualified (dotted) module name.  Returns the
          imported module on success, raises *note ZipImportError: 4ab8.
          on failure.

          Deprecated since version 3.10, will be removed in version
          3.15: Use *note exec_module(): 339. instead.

      -- Metodo: invalidate_caches ()

          Clear out the internal cache of information about files found
          within the ZIP archive.

          Added in version 3.10.

      -- Attributo: archive

          The file name of the importer’s associated ZIP file, without a
          possible subpath.

      -- Attributo: prefix

          The subpath within the ZIP file where modules are searched.
          This is the empty string for zipimporter objects which point
          to the root of the ZIP file.

     The *note archive: 4ac1. and *note prefix: 4ac2. attributes, when
     combined with a slash, equal the original 'archivepath' argument
     given to the *note zipimporter: 4abb. constructor.


File: python.info,  Node: Examples<34>,  Prev: zipimporter Objects,  Up: zipimport — Import modules from Zip archives

5.31.1.2 Examples
.................

Here is an example that imports a module from a ZIP archive - note that
the *note zipimport: 138. module is not explicitly used.

     $ unzip -l example_archive.zip
     Archive:  example_archive.zip
       Length     Date   Time    Name
      --------    ----   ----    ----
          8467  01-01-00 12:30   example.py
      --------                   -------
          8467                   1 file

     >>> import sys
     >>> # Add the archive to the front of the module search path
     >>> sys.path.insert(0, 'example_archive.zip')
     >>> import example
     >>> example.__file__
     'example_archive.zip/example.py'


File: python.info,  Node: pkgutil — Package extension utility,  Next: modulefinder — Find modules used by a script,  Prev: zipimport — Import modules from Zip archives,  Up: Importing Modules

5.31.2 ‘pkgutil’ — Package extension utility
--------------------------------------------

'Source code:' Lib/pkgutil.py(1)

__________________________________________________________________

This module provides utilities for the import system, in particular
package support.

 -- Classe: pkgutil.ModuleInfo (module_finder, name, ispkg)

     A namedtuple that holds a brief summary of a module’s info.

     Added in version 3.6.

 -- Funzione: pkgutil.extend_path (path, name)

     Extend the search path for the modules which comprise a package.
     Intended use is to place the following code in a package’s
     ‘__init__.py’:

          from pkgutil import extend_path
          __path__ = extend_path(__path__, __name__)

     For each directory on *note sys.path: 3e4. that has a subdirectory
     that matches the package name, add the subdirectory to the
     package’s *note __path__: 203e.  This is useful if one wants to
     distribute different parts of a single logical package as multiple
     directories.

     It also looks for ‘*.pkg’ files beginning where ‘*’ matches the
     'name' argument.  This feature is similar to ‘*.pth’ files (see the
     *note site: cc. module for more information), except that it
     doesn’t special-case lines starting with ‘import’.  A ‘*.pkg’ file
     is trusted at face value: apart from skipping blank lines and
     ignoring comments, all entries found in a ‘*.pkg’ file are added to
     the path, regardless of whether they exist on the filesystem (this
     is a feature).

     If the input path is not a list (as is the case for frozen
     packages) it is returned unchanged.  The input path is not
     modified; an extended copy is returned.  Items are only appended to
     the copy at the end.

     It is assumed that *note sys.path: 3e4. is a sequence.  Items of
     *note sys.path: 3e4. that are not strings referring to existing
     directories are ignored.  Unicode items on *note sys.path: 3e4.
     that cause errors when used as filenames may cause this function to
     raise an exception (in line with *note os.path.isdir(): c07.
     behavior).

 -- Funzione: pkgutil.get_importer (path_item)

     Retrieve a *note finder: 2351. for the given 'path_item'.

     The returned finder is cached in *note sys.path_importer_cache:
     7fb. if it was newly created by a path hook.

     The cache (or part of it) can be cleared manually if a rescan of
     *note sys.path_hooks: 1226. is necessary.

     Cambiato nella versione 3.3: Updated to be based directly on *note
     importlib: 7b. rather than relying on the package internal PEP
     302(2) import emulation.

 -- Funzione: pkgutil.iter_importers (fullname='')

     Yield *note finder: 2351. objects for the given module name.

     If 'fullname' contains a ‘'.'’, the finders will be for the package
     containing 'fullname', otherwise they will be all registered top
     level finders (i.e.  those on both *note sys.meta_path: f29. and
     *note sys.path_hooks: 1226.).

     If the named module is in a package, that package is imported as a
     side effect of invoking this function.

     If no module name is specified, all top level finders are produced.

     Cambiato nella versione 3.3: Updated to be based directly on *note
     importlib: 7b. rather than relying on the package internal PEP
     302(3) import emulation.

 -- Funzione: pkgutil.iter_modules (path=None, prefix='')

     Yields *note ModuleInfo: f4a. for all submodules on 'path', or, if
     'path' is ‘None’, all top-level modules on *note sys.path: 3e4.

     'path' should be either ‘None’ or a list of paths to look for
     modules in.

     'prefix' is a string to output on the front of every module name on
     output.

          Nota: Only works for a *note finder: 2351. which defines an
          ‘iter_modules()’ method.  This interface is non-standard, so
          the module also provides implementations for *note
          importlib.machinery.FileFinder: 1274. and *note
          zipimport.zipimporter: 4abb.

     Cambiato nella versione 3.3: Updated to be based directly on *note
     importlib: 7b. rather than relying on the package internal PEP
     302(4) import emulation.

 -- Funzione: pkgutil.walk_packages (path=None, prefix='', onerror=None)

     Yields *note ModuleInfo: f4a. for all modules recursively on
     'path', or, if 'path' is ‘None’, all accessible modules.

     'path' should be either ‘None’ or a list of paths to look for
     modules in.

     'prefix' is a string to output on the front of every module name on
     output.

     Note that this function must import all 'packages' ('not' all
     modules!)  on the given 'path', in order to access the ‘__path__’
     attribute to find submodules.

     'onerror' is a function which gets called with one argument (the
     name of the package which was being imported) if any exception
     occurs while trying to import a package.  If no 'onerror' function
     is supplied, *note ImportError: 65b.s are caught and ignored, while
     all other exceptions are propagated, terminating the search.

     Examples:

          # list all modules python can access
          walk_packages()

          # list all submodules of ctypes
          walk_packages(ctypes.__path__, ctypes.__name__ + '.')

          Nota: Only works for a *note finder: 2351. which defines an
          ‘iter_modules()’ method.  This interface is non-standard, so
          the module also provides implementations for *note
          importlib.machinery.FileFinder: 1274. and *note
          zipimport.zipimporter: 4abb.

     Cambiato nella versione 3.3: Updated to be based directly on *note
     importlib: 7b. rather than relying on the package internal PEP
     302(5) import emulation.

 -- Funzione: pkgutil.get_data (package, resource)

     Get a resource from a package.

     This is a wrapper for the *note loader: 1a10. *note get_data: 4aca.
     API. The 'package' argument should be the name of a package, in
     standard module format (‘foo.bar’).  The 'resource' argument should
     be in the form of a relative filename, using ‘/’ as the path
     separator.  The parent directory name ‘..’ is not allowed, and nor
     is a rooted name (starting with a ‘/’).

     The function returns a binary string that is the contents of the
     specified resource.

     For packages located in the filesystem, which have already been
     imported, this is the rough equivalent of:

          d = os.path.dirname(sys.modules[package].__file__)
          data = open(os.path.join(d, resource), 'rb').read()

     If the package cannot be located or loaded, or it uses a *note
     loader: 1a10. which does not support *note get_data: 4aca, then
     ‘None’ is returned.  In particular, the *note loader: 1a10. for
     *note namespace packages: 2b2. does not support *note get_data:
     4aca.

 -- Funzione: pkgutil.resolve_name (name)

     Resolve a name to an object.

     This functionality is used in numerous places in the standard
     library (see bpo-12915(6)) - and equivalent functionality is also
     in widely used third-party packages such as setuptools, Django and
     Pyramid.

     It is expected that 'name' will be a string in one of the following
     formats, where W is shorthand for a valid Python identifier and dot
     stands for a literal period in these pseudo-regexes:

        * ‘W(.W)*’

        * ‘W(.W)*:(W(.W)*)?’

     The first form is intended for backward compatibility only.  It
     assumes that some part of the dotted name is a package, and the
     rest is an object somewhere within that package, possibly nested
     inside other objects.  Because the place where the package stops
     and the object hierarchy starts can’t be inferred by inspection,
     repeated attempts to import must be done with this form.

     In the second form, the caller makes the division point clear
     through the provision of a single colon: the dotted name to the
     left of the colon is a package to be imported, and the dotted name
     to the right is the object hierarchy within that package.  Only one
     import is needed in this form.  If it ends with the colon, then a
     module object is returned.

     The function will return an object (which might be a module), or
     raise one of the following exceptions:

     *note ValueError: 2ec. – if 'name' isn’t in a recognised format.

     *note ImportError: 65b. – if an import failed when it shouldn’t
     have.

     *note AttributeError: 5f0. – If a failure occurred when traversing
     the object hierarchy within the imported package to get to the
     desired object.

     Added in version 3.9.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/pkgutil.py

   (2) https://peps.python.org/pep-0302/

   (3) https://peps.python.org/pep-0302/

   (4) https://peps.python.org/pep-0302/

   (5) https://peps.python.org/pep-0302/

   (6) https://bugs.python.org/issue?@action=redirect&bpo=12915


File: python.info,  Node: modulefinder — Find modules used by a script,  Next: runpy — Locating and executing Python modules,  Prev: pkgutil — Package extension utility,  Up: Importing Modules

5.31.3 ‘modulefinder’ — Find modules used by a script
-----------------------------------------------------

'Source code:' Lib/modulefinder.py(1)

__________________________________________________________________

This module provides a *note ModuleFinder: 1dcd. class that can be used
to determine the set of modules imported by a script.  ‘modulefinder.py’
can also be run as a script, giving the filename of a Python script as
its argument, after which a report of the imported modules will be
printed.

 -- Funzione: modulefinder.AddPackagePath (pkg_name, path)

     Record that the package named 'pkg_name' can be found in the
     specified 'path'.

 -- Funzione: modulefinder.ReplacePackage (oldname, newname)

     Allows specifying that the module named 'oldname' is in fact the
     package named 'newname'.

 -- Classe: modulefinder.ModuleFinder (path=None, debug=0, excludes=[],
          replace_paths=[])

     This class provides *note run_script(): 4ad1. and *note report():
     4ad2. methods to determine the set of modules imported by a script.
     'path' can be a list of directories to search for modules; if not
     specified, ‘sys.path’ is used.  'debug' sets the debugging level;
     higher values make the class print debugging messages about what
     it’s doing.  'excludes' is a list of module names to exclude from
     the analysis.  'replace_paths' is a list of ‘(oldpath, newpath)’
     tuples that will be replaced in module paths.

      -- Metodo: report ()

          Print a report to standard output that lists the modules
          imported by the script and their paths, as well as modules
          that are missing or seem to be missing.

      -- Metodo: run_script (pathname)

          Analyze the contents of the 'pathname' file, which must
          contain Python code.

      -- Attributo: modules

          A dictionary mapping module names to modules.  See *note
          Example usage of ModuleFinder: 4ad4.

* Menu:

* Example usage of ModuleFinder::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/modulefinder.py


File: python.info,  Node: Example usage of ModuleFinder,  Up: modulefinder — Find modules used by a script

5.31.3.1 Example usage of ‘ModuleFinder’
........................................

The script that is going to get analyzed later on (bacon.py):

     import re, itertools

     try:
         import baconhameggs
     except ImportError:
         pass

     try:
         import guido.python.ham
     except ImportError:
         pass

The script that will output the report of bacon.py:

     from modulefinder import ModuleFinder

     finder = ModuleFinder()
     finder.run_script('bacon.py')

     print('Loaded modules:')
     for name, mod in finder.modules.items():
         print('%s: ' % name, end='')
         print(','.join(list(mod.globalnames.keys())[:3]))

     print('-'*50)
     print('Modules not imported:')
     print('\n'.join(finder.badmodules.keys()))

Sample output (may vary depending on the architecture):

     Loaded modules:
     _types:
     copyreg:  _inverted_registry,_slotnames,__all__
     re._compiler:  isstring,_sre,_optimize_unicode
     _sre:
     re._constants:  REPEAT_ONE,makedict,AT_END_LINE
     sys:
     re:  __module__,finditer,_expand
     itertools:
     __main__:  re,itertools,baconhameggs
     re._parser:  _PATTERNENDERS,SRE_FLAG_UNICODE
     array:
     types:  __module__,IntType,TypeType
     ---------------------------------------------------
     Modules not imported:
     guido.python.ham
     baconhameggs


File: python.info,  Node: runpy — Locating and executing Python modules,  Next: importlib — The implementation of import,  Prev: modulefinder — Find modules used by a script,  Up: Importing Modules

5.31.4 ‘runpy’ — Locating and executing Python modules
------------------------------------------------------

'Source code:' Lib/runpy.py(1)

__________________________________________________________________

The *note runpy: c3. module is used to locate and run Python modules
without importing them first.  Its main use is to implement the *note
-m: 23c. command line switch that allows scripts to be located using the
Python module namespace rather than the filesystem.

Note that this is 'not' a sandbox module - all code is executed in the
current process, and any side effects (such as cached imports of other
modules) will remain in place after the functions have returned.

Furthermore, any functions and classes defined by the executed code are
not guaranteed to work correctly after a *note runpy: c3. function has
returned.  If that limitation is not acceptable for a given use case,
*note importlib: 7b. is likely to be a more suitable choice than this
module.

The *note runpy: c3. module provides two functions:

 -- Funzione: runpy.run_module (mod_name, init_globals=None,
          run_name=None, alter_sys=False)

     Execute the code of the specified module and return the resulting
     module’s globals dictionary.  The module’s code is first located
     using the standard import mechanism (refer to PEP 302(2) for
     details) and then executed in a fresh module namespace.

     The 'mod_name' argument should be an absolute module name.  If the
     module name refers to a package rather than a normal module, then
     that package is imported and the *note __main__: 1. submodule
     within that package is then executed and the resulting module
     globals dictionary returned.

     The optional dictionary argument 'init_globals' may be used to
     pre-populate the module’s globals dictionary before the code is
     executed.  'init_globals' will not be modified.  If any of the
     special global variables below are defined in 'init_globals', those
     definitions are overridden by *note run_module(): 1b7f.

     The special global variables ‘__name__’, ‘__spec__’, ‘__file__’,
     ‘__cached__’, ‘__loader__’ and ‘__package__’ are set in the globals
     dictionary before the module code is executed.  (Note that this is
     a minimal set of variables - other variables may be set implicitly
     as an interpreter implementation detail.)

     ‘__name__’ is set to 'run_name' if this optional argument is not
     *note None: 886, to ‘mod_name + '.__main__'’ if the named module is
     a package and to the 'mod_name' argument otherwise.

     ‘__spec__’ will be set appropriately for the 'actually' imported
     module (that is, ‘__spec__.name’ will always be 'mod_name' or
     ‘mod_name + '.__main__'’, never 'run_name').

     ‘__file__’, ‘__cached__’, ‘__loader__’ and ‘__package__’ are *note
     set as normal: 2348. based on the module spec.

     If the argument 'alter_sys' is supplied and evaluates to *note
     True: e09, then ‘sys.argv[0]’ is updated with the value of
     ‘__file__’ and ‘sys.modules[__name__]’ is updated with a temporary
     module object for the module being executed.  Both ‘sys.argv[0]’
     and ‘sys.modules[__name__]’ are restored to their original values
     before the function returns.

     Note that this manipulation of *note sys: df. is not thread-safe.
     Other threads may see the partially initialised module, as well as
     the altered list of arguments.  It is recommended that the ‘sys’
     module be left alone when invoking this function from threaded
     code.

     Vedi anche
     ..........

     The *note -m: 23c. option offering equivalent functionality from
     the command line.

     Cambiato nella versione 3.1: Added ability to execute packages by
     looking for a *note __main__: 1. submodule.

     Cambiato nella versione 3.2: Added ‘__cached__’ global variable
     (see PEP 3147(3)).

     Cambiato nella versione 3.4: Updated to take advantage of the
     module spec feature added by PEP 451(4).  This allows ‘__cached__’
     to be set correctly for modules run this way, as well as ensuring
     the real module name is always accessible as ‘__spec__.name’.

     Cambiato nella versione 3.12: The setting of ‘__cached__’,
     ‘__loader__’, and ‘__package__’ are deprecated.  See *note
     ModuleSpec: 2255. for alternatives.

 -- Funzione: runpy.run_path (path_name, init_globals=None,
          run_name=None)

     Execute the code at the named filesystem location and return the
     resulting module’s globals dictionary.  As with a script name
     supplied to the CPython command line, 'file_path' may refer to a
     Python source file, a compiled bytecode file or a valid *note
     sys.path: 3e4. entry containing a *note __main__: 1. module (e.g.
     a zipfile containing a top-level ‘__main__.py’ file).

     For a simple script, the specified code is simply executed in a
     fresh module namespace.  For a valid *note sys.path: 3e4. entry
     (typically a zipfile or directory), the entry is first added to the
     beginning of ‘sys.path’.  The function then looks for and executes
     a *note __main__: 1. module using the updated path.  Note that
     there is no special protection against invoking an existing
     ‘__main__’ entry located elsewhere on ‘sys.path’ if there is no
     such module at the specified location.

     The optional dictionary argument 'init_globals' may be used to
     pre-populate the module’s globals dictionary before the code is
     executed.  'init_globals' will not be modified.  If any of the
     special global variables below are defined in 'init_globals', those
     definitions are overridden by *note run_path(): 4a5.

     The special global variables ‘__name__’, ‘__spec__’, ‘__file__’,
     ‘__cached__’, ‘__loader__’ and ‘__package__’ are set in the globals
     dictionary before the module code is executed.  (Note that this is
     a minimal set of variables - other variables may be set implicitly
     as an interpreter implementation detail.)

     ‘__name__’ is set to 'run_name' if this optional argument is not
     *note None: 886. and to ‘'<run_path>'’ otherwise.

     If 'file_path' directly references a script file (whether as source
     or as precompiled byte code), then ‘__file__’ will be set to
     'file_path', and ‘__spec__’, ‘__cached__’, ‘__loader__’ and
     ‘__package__’ will all be set to *note None: 886.

     If 'file_path' is a reference to a valid *note sys.path: 3e4.
     entry, then ‘__spec__’ will be set appropriately for the imported
     *note __main__: 1. module (that is, ‘__spec__.name’ will always be
     ‘__main__’).  ‘__file__’, ‘__cached__’, ‘__loader__’ and
     ‘__package__’ will be *note set as normal: 2348. based on the
     module spec.

     A number of alterations are also made to the *note sys: df. module.
     Firstly, *note sys.path: 3e4. may be altered as described above.
     ‘sys.argv[0]’ is updated with the value of 'file_path' and
     ‘sys.modules[__name__]’ is updated with a temporary module object
     for the module being executed.  All modifications to items in *note
     sys: df. are reverted before the function returns.

     Note that, unlike *note run_module(): 1b7f, the alterations made to
     *note sys: df. are not optional in this function as these
     adjustments are essential to allowing the execution of *note
     sys.path: 3e4. entries.  As the thread-safety limitations still
     apply, use of this function in threaded code should be either
     serialised with the import lock or delegated to a separate process.

     Vedi anche
     ..........

     *note Interface options: 2104. for equivalent functionality on the
     command line (‘python path/to/script’).

     Added in version 3.2.

     Cambiato nella versione 3.4: Updated to take advantage of the
     module spec feature added by PEP 451(5).  This allows ‘__cached__’
     to be set correctly in the case where ‘__main__’ is imported from a
     valid *note sys.path: 3e4. entry rather than being executed
     directly.

     Cambiato nella versione 3.12: The setting of ‘__cached__’,
     ‘__loader__’, and ‘__package__’ are deprecated.

Vedi anche
..........

PEP 338(6) – Executing modules as scripts

     PEP written and implemented by Nick Coghlan.

PEP 366(7) – Main module explicit relative imports

     PEP written and implemented by Nick Coghlan.

PEP 451(8) – A ModuleSpec Type for the Import System

     PEP written and implemented by Eric Snow

*note Command line and environment: 1d8f. - CPython command line details

The *note importlib.import_module(): 73d. function

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/runpy.py

   (2) https://peps.python.org/pep-0302/

   (3) https://peps.python.org/pep-3147/

   (4) https://peps.python.org/pep-0451/

   (5) https://peps.python.org/pep-0451/

   (6) https://peps.python.org/pep-0338/

   (7) https://peps.python.org/pep-0366/

   (8) https://peps.python.org/pep-0451/


File: python.info,  Node: importlib — The implementation of import,  Next: importlib resources – Package resource reading opening and access,  Prev: runpy — Locating and executing Python modules,  Up: Importing Modules

5.31.5 ‘importlib’ — The implementation of ‘import’
---------------------------------------------------

Added in version 3.1.

'Source code:' Lib/importlib/__init__.py(1)

__________________________________________________________________

* Menu:

* Introduction: Introduction<12>.
* Functions: Functions<12>.
* importlib.abc – Abstract base classes related to import: importlib abc – Abstract base classes related to import.
* importlib.machinery – Importers and path hooks: importlib machinery – Importers and path hooks.
* importlib.util – Utility code for importers: importlib util – Utility code for importers.
* Examples: Examples<35>.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/importlib/__init__.py


File: python.info,  Node: Introduction<12>,  Next: Functions<12>,  Up: importlib — The implementation of import

5.31.5.1 Introduction
.....................

The purpose of the *note importlib: 7b. package is three-fold.

One is to provide the implementation of the *note import: 7f9. statement
(and thus, by extension, the *note __import__(): ad3. function) in
Python source code.  This provides an implementation of ‘import’ which
is portable to any Python interpreter.  This also provides an
implementation which is easier to comprehend than one implemented in a
programming language other than Python.

Two, the components to implement *note import: 7f9. are exposed in this
package, making it easier for users to create their own custom objects
(known generically as an *note importer: 242c.) to participate in the
import process.

Three, the package contains modules exposing additional functionality
for managing aspects of Python packages:

   * *note importlib.metadata: 7e. presents access to metadata from
     third-party distributions.

   * *note importlib.resources: 7f. provides routines for accessing
     non-code «resources» from Python packages.

Vedi anche
..........

*note The import statement: 7f9.

     The language reference for the *note import: 7f9. statement.

Packages specification(1)

     Original specification of packages.  Some semantics have changed
     since the writing of this document (e.g.  redirecting based on
     ‘None’ in *note sys.modules: 17ce.).

The *note __import__(): 126f. function

     The *note import: 7f9. statement is syntactic sugar for this
     function.

*note The initialization of the sys.path module search path: 18c4.

     The initialization of *note sys.path: 3e4.

PEP 235(2)

     Import on Case-Insensitive Platforms

PEP 263(3)

     Defining Python Source Code Encodings

PEP 302(4)

     New Import Hooks

PEP 328(5)

     Imports: Multi-Line and Absolute/Relative

PEP 366(6)

     Main module explicit relative imports

PEP 420(7)

     Implicit namespace packages

PEP 451(8)

     A ModuleSpec Type for the Import System

PEP 488(9)

     Elimination of PYO files

PEP 489(10)

     Multi-phase extension module initialization

PEP 552(11)

     Deterministic pycs

PEP 3120(12)

     Using UTF-8 as the Default Source Encoding

PEP 3147(13)

     PYC Repository Directories

   ---------- Footnotes ----------

   (1) https://www.python.org/doc/essays/packages/

   (2) https://peps.python.org/pep-0235/

   (3) https://peps.python.org/pep-0263/

   (4) https://peps.python.org/pep-0302/

   (5) https://peps.python.org/pep-0328/

   (6) https://peps.python.org/pep-0366/

   (7) https://peps.python.org/pep-0420/

   (8) https://peps.python.org/pep-0451/

   (9) https://peps.python.org/pep-0488/

   (10) https://peps.python.org/pep-0489/

   (11) https://peps.python.org/pep-0552/

   (12) https://peps.python.org/pep-3120/

   (13) https://peps.python.org/pep-3147/


File: python.info,  Node: Functions<12>,  Next: importlib abc – Abstract base classes related to import,  Prev: Introduction<12>,  Up: importlib — The implementation of import

5.31.5.2 Functions
..................

 -- Funzione: importlib.__import__ (name, globals=None, locals=None,
          fromlist=(), level=0)

     An implementation of the built-in *note __import__(): ad3.
     function.

          Nota: Programmatic importing of modules should use *note
          import_module(): 73d. instead of this function.

 -- Funzione: importlib.import_module (name, package=None)

     Import a module.  The 'name' argument specifies what module to
     import in absolute or relative terms (e.g.  either ‘pkg.mod’ or
     ‘..mod’).  If the name is specified in relative terms, then the
     'package' argument must be set to the name of the package which is
     to act as the anchor for resolving the package name (e.g.
     ‘import_module('..mod', 'pkg.subpkg')’ will import ‘pkg.mod’).

     The *note import_module(): 73d. function acts as a simplifying
     wrapper around *note importlib.__import__(): 126f.  This means all
     semantics of the function are derived from *note
     importlib.__import__(): 126f.  The most important difference
     between these two functions is that *note import_module(): 73d.
     returns the specified package or module (e.g.  ‘pkg.mod’), while
     *note __import__(): ad3. returns the top-level package or module
     (e.g.  ‘pkg’).

     If you are dynamically importing a module that was created since
     the interpreter began execution (e.g., created a Python source
     file), you may need to call *note invalidate_caches(): e0c. in
     order for the new module to be noticed by the import system.

     Cambiato nella versione 3.3: Parent packages are automatically
     imported.

 -- Funzione: importlib.invalidate_caches ()

     Invalidate the internal caches of finders stored at *note
     sys.meta_path: f29.  If a finder implements ‘invalidate_caches()’
     then it will be called to perform the invalidation.  This function
     should be called if any modules are created/installed while your
     program is running to guarantee all finders will notice the new
     module’s existence.

     Added in version 3.3.

     Cambiato nella versione 3.10: Namespace packages created/installed
     in a different *note sys.path: 3e4. location after the same
     namespace was already imported are noticed.

 -- Funzione: importlib.reload (module)

     Reload a previously imported 'module'.  The argument must be a
     module object, so it must have been successfully imported before.
     This is useful if you have edited the module source file using an
     external editor and want to try out the new version without leaving
     the Python interpreter.  The return value is the module object
     (which can be different if re-importing causes a different object
     to be placed in *note sys.modules: 17ce.).

     When *note reload(): 73e. is executed:

        * Python module’s code is recompiled and the module-level code
          re-executed, defining a new set of objects which are bound to
          names in the module’s dictionary by reusing the *note loader:
          1a10. which originally loaded the module.  The ‘init’ function
          of extension modules is not called a second time.

        * As with all other objects in Python the old objects are only
          reclaimed after their reference counts drop to zero.

        * The names in the module namespace are updated to point to any
          new or changed objects.

        * Other references to the old objects (such as names external to
          the module) are not rebound to refer to the new objects and
          must be updated in each namespace where they occur if that is
          desired.

     There are a number of other caveats:

     When a module is reloaded, its dictionary (containing the module’s
     global variables) is retained.  Redefinitions of names will
     override the old definitions, so this is generally not a problem.
     If the new version of a module does not define a name that was
     defined by the old version, the old definition remains.  This
     feature can be used to the module’s advantage if it maintains a
     global table or cache of objects — with a *note try: 8f9. statement
     it can test for the table’s presence and skip its initialization if
     desired:

          try:
              cache
          except NameError:
              cache = {}

     It is generally not very useful to reload built-in or dynamically
     loaded modules.  Reloading *note sys: df, *note __main__: 1, *note
     builtins: 13. and other key modules is not recommended.  In many
     cases extension modules are not designed to be initialized more
     than once, and may fail in arbitrary ways when reloaded.

     If a module imports objects from another module using *note from:
     14b3. … *note import: 7f9. …, calling *note reload(): 73e. for the
     other module does not redefine the objects imported from it — one
     way around this is to re-execute the ‘from’ statement, another is
     to use ‘import’ and qualified names ('module.name') instead.

     If a module instantiates instances of a class, reloading the module
     that defines the class does not affect the method definitions of
     the instances — they continue to use the old class definition.  The
     same is true for derived classes.

     Added in version 3.4.

     Cambiato nella versione 3.7: *note ModuleNotFoundError: d3f. is
     raised when the module being reloaded lacks a *note ModuleSpec:
     2255.

          Avvertimento: This function is not thread-safe.  Calling it
          from multiple threads can result in unexpected behavior.  It’s
          recommended to use the *note threading.Lock: 19dc. or other
          synchronization primitives for thread-safe module reloading.


File: python.info,  Node: importlib abc – Abstract base classes related to import,  Next: importlib machinery – Importers and path hooks,  Prev: Functions<12>,  Up: importlib — The implementation of import

5.31.5.3 ‘importlib.abc’ – Abstract base classes related to import
..................................................................

'Source code:' Lib/importlib/abc.py(1)

__________________________________________________________________

The *note importlib.abc: 7c. module contains all of the core abstract
base classes used by *note import: 7f9.  Some subclasses of the core
abstract base classes are also provided to help in implementing the core
ABCs.

ABC hierarchy:

     object
      +-- MetaPathFinder
      +-- PathEntryFinder
      +-- Loader
           +-- ResourceLoader --------+
           +-- InspectLoader          |
                +-- ExecutionLoader --+
                                      +-- FileLoader
                                      +-- SourceLoader

 -- Classe: importlib.abc.MetaPathFinder

     An abstract base class representing a *note meta path finder: 1272.

     Added in version 3.3.

     Cambiato nella versione 3.10: No longer a subclass of ‘Finder’.

      -- Metodo: find_spec (fullname, path, target=None)

          An abstract method for finding a *note spec: 234a. for the
          specified module.  If this is a top-level import, 'path' will
          be ‘None’.  Otherwise, this is a search for a subpackage or
          module and 'path' will be the value of *note __path__: 203e.
          from the parent package.  If a spec cannot be found, ‘None’ is
          returned.  When passed in, ‘target’ is a module object that
          the finder may use to make a more educated guess about what
          spec to return.  *note importlib.util.spec_from_loader(): a6f.
          may be useful for implementing concrete ‘MetaPathFinders’.

          Added in version 3.4.

      -- Metodo: invalidate_caches ()

          An optional method which, when called, should invalidate any
          internal cache used by the finder.  Used by *note
          importlib.invalidate_caches(): e0c. when invalidating the
          caches of all finders on *note sys.meta_path: f29.

          Cambiato nella versione 3.4: Returns ‘None’ when called
          instead of *note NotImplemented: 1a2.

 -- Classe: importlib.abc.PathEntryFinder

     An abstract base class representing a *note path entry finder:
     1273.  Though it bears some similarities to *note MetaPathFinder:
     a70, ‘PathEntryFinder’ is meant for use only within the path-based
     import subsystem provided by *note importlib.machinery.PathFinder:
     1225.

     Added in version 3.3.

     Cambiato nella versione 3.10: No longer a subclass of ‘Finder’.

      -- Metodo: find_spec (fullname, target=None)

          An abstract method for finding a *note spec: 234a. for the
          specified module.  The finder will search for the module only
          within the *note path entry: 243b. to which it is assigned.
          If a spec cannot be found, ‘None’ is returned.  When passed
          in, ‘target’ is a module object that the finder may use to
          make a more educated guess about what spec to return.  *note
          importlib.util.spec_from_loader(): a6f. may be useful for
          implementing concrete ‘PathEntryFinders’.

          Added in version 3.4.

      -- Metodo: invalidate_caches ()

          An optional method which, when called, should invalidate any
          internal cache used by the finder.  Used by *note
          importlib.machinery.PathFinder.invalidate_caches(): e0b. when
          invalidating the caches of all cached finders.

 -- Classe: importlib.abc.Loader

     An abstract base class for a *note loader: 1a10.  See PEP 302(2)
     for the exact definition for a loader.

     Loaders that wish to support resource reading should implement a
     ‘get_resource_reader()’ method as specified by *note
     importlib.resources.abc.ResourceReader: 4ae1.

     Cambiato nella versione 3.7: Introduced the optional
     ‘get_resource_reader()’ method.

      -- Metodo: create_module (spec)

          A method that returns the module object to use when importing
          a module.  This method may return ‘None’, indicating that
          default module creation semantics should take place.

          Added in version 3.4.

          Cambiato nella versione 3.6: This method is no longer optional
          when *note exec_module(): a6c. is defined.

      -- Metodo: exec_module (module)

          An abstract method that executes the module in its own
          namespace when a module is imported or reloaded.  The module
          should already be initialized when *note exec_module(): a6c.
          is called.  When this method exists, *note create_module():
          eae. must be defined.

          Added in version 3.4.

          Cambiato nella versione 3.6: *note create_module(): eae. must
          also be defined.

      -- Metodo: load_module (fullname)

          A legacy method for loading a module.  If the module cannot be
          loaded, *note ImportError: 65b. is raised, otherwise the
          loaded module is returned.

          If the requested module already exists in *note sys.modules:
          17ce, that module should be used and reloaded.  Otherwise the
          loader should create a new module and insert it into *note
          sys.modules: 17ce. before any loading begins, to prevent
          recursion from the import.  If the loader inserted a module
          and the load fails, it must be removed by the loader from
          *note sys.modules: 17ce.; modules already in *note
          sys.modules: 17ce. before the loader began execution should be
          left alone.

          The loader should set several attributes on the module (note
          that some of these attributes can change when a module is
          reloaded):

             - *note module.__name__: 1593.

             - *note module.__file__: 2350.

             - *note module.__cached__: 321. '(deprecated)'

             - *note module.__path__: 203e.

             - *note module.__package__: 323. '(deprecated)'

             - *note module.__loader__: 33b. '(deprecated)'

          When *note exec_module(): a6c. is available then
          backwards-compatible functionality is provided.

          Cambiato nella versione 3.4: Raise *note ImportError: 65b.
          when called instead of *note NotImplementedError: 36b.
          Functionality provided when *note exec_module(): a6c. is
          available.

          Deprecated since version 3.4, will be removed in version 3.15:
          The recommended API for loading a module is *note
          exec_module(): a6c. (and *note create_module(): eae.).
          Loaders should implement it instead of *note load_module():
          a6b.  The import machinery takes care of all the other
          responsibilities of *note load_module(): a6b. when *note
          exec_module(): a6c. is implemented.

 -- Classe: importlib.abc.ResourceLoader

     'Superseded by TraversableResources'

          An abstract base class for a *note loader: 1a10. which
          implements the optional PEP 302(3) protocol for loading
          arbitrary resources from the storage back-end.

          Deprecato dalla versione 3.7: This ABC is deprecated in favour
          of supporting resource loading through *note
          importlib.resources.abc.TraversableResources: 2f9.  This class
          exists for backwards compatibility only with other ABCs in
          this module.

           -- Metodo: abstractmethod get_data (path)

                    An abstract method to return the bytes for the data
                    located at 'path'.  Loaders that have a file-like
                    storage back-end that allows storing arbitrary data
                    can implement this abstract method to give direct
                    access to the data stored.  *note OSError: 2c0. is
                    to be raised if the 'path' cannot be found.  The
                    'path' is expected to be constructed using a
                    module’s *note __file__: 2350. attribute or an item
                    from a package’s *note __path__: 203e.

                    Cambiato nella versione 3.4: Raises *note OSError:
                    2c0. instead of *note NotImplementedError: 36b.

 -- Classe: importlib.abc.InspectLoader

     An abstract base class for a *note loader: 1a10. which implements
     the optional PEP 302(4) protocol for loaders that inspect modules.

      -- Metodo: get_code (fullname)

          Return the code object for a module, or ‘None’ if the module
          does not have a code object (as would be the case, for
          example, for a built-in module).  Raise an *note ImportError:
          65b. if loader cannot find the requested module.

               Nota: While the method has a default implementation, it
               is suggested that it be overridden if possible for
               performance.

          Cambiato nella versione 3.4: No longer abstract and a concrete
          implementation is provided.

      -- Metodo: abstractmethod get_source (fullname)

               An abstract method to return the source of a module.  It
               is returned as a text string using *note universal
               newlines: f37, translating all recognized line separators
               into ‘'\n'’ characters.  Returns ‘None’ if no source is
               available (e.g.  a built-in module).  Raises *note
               ImportError: 65b. if the loader cannot find the module
               specified.

               Cambiato nella versione 3.4: Raises *note ImportError:
               65b. instead of *note NotImplementedError: 36b.

      -- Metodo: is_package (fullname)

          An optional method to return a true value if the module is a
          package, a false value otherwise.  *note ImportError: 65b. is
          raised if the *note loader: 1a10. cannot find the module.

          Cambiato nella versione 3.4: Raises *note ImportError: 65b.
          instead of *note NotImplementedError: 36b.

      -- Metodo: static source_to_code (data, path='<string>')

          Create a code object from Python source.

          The 'data' argument can be whatever the *note compile(): 4b2.
          function supports (i.e.  string or bytes).  The 'path'
          argument should be the «path» to where the source code
          originated from, which can be an abstract concept (e.g.
          location in a zip file).

          With the subsequent code object one can execute it in a module
          by running ‘exec(code, module.__dict__)’.

          Added in version 3.4.

          Cambiato nella versione 3.5: Made the method static.

      -- Metodo: exec_module (module)

          Implementation of *note Loader.exec_module(): a6c.

          Added in version 3.4.

      -- Metodo: load_module (fullname)

          Implementation of *note Loader.load_module(): a6b.

          Deprecated since version 3.4, will be removed in version 3.15:
          use *note exec_module(): 1214. instead.

 -- Classe: importlib.abc.ExecutionLoader

     An abstract base class which inherits from *note InspectLoader:
     1156. that, when implemented, helps a module to be executed as a
     script.  The ABC represents an optional PEP 302(5) protocol.

      -- Metodo: abstractmethod get_filename (fullname)

               An abstract method that is to return the value of *note
               __file__: 2350. for the specified module.  If no path is
               available, *note ImportError: 65b. is raised.

               If source code is available, then the method should
               return the path to the source file, regardless of whether
               a bytecode was used to load the module.

               Cambiato nella versione 3.4: Raises *note ImportError:
               65b. instead of *note NotImplementedError: 36b.

 -- Classe: importlib.abc.FileLoader (fullname, path)

     An abstract base class which inherits from *note ResourceLoader:
     de4. and *note ExecutionLoader: 4ae4, providing concrete
     implementations of *note ResourceLoader.get_data(): 4aca. and *note
     ExecutionLoader.get_filename(): 4ae5.

     The 'fullname' argument is a fully resolved name of the module the
     loader is to handle.  The 'path' argument is the path to the file
     for the module.

     Added in version 3.3.

      -- Attributo: name

          The name of the module the loader can handle.

      -- Attributo: path

          Path to the file of the module.

      -- Metodo: load_module (fullname)

          Calls super’s ‘load_module()’.

          Deprecated since version 3.4, will be removed in version 3.15:
          Use *note Loader.exec_module(): a6c. instead.

      -- Metodo: abstractmethod get_filename (fullname)

          Returns *note path: 4ae7.

      -- Metodo: abstractmethod get_data (path)

          Reads 'path' as a binary file and returns the bytes from it.

 -- Classe: importlib.abc.SourceLoader

     An abstract base class for implementing source (and optionally
     bytecode) file loading.  The class inherits from both *note
     ResourceLoader: de4. and *note ExecutionLoader: 4ae4, requiring the
     implementation of:

        * *note ResourceLoader.get_data(): 4aca.

        * 
          *note ExecutionLoader.get_filename(): 4ae5.

               Should only return the path to the source file;
               sourceless loading is not supported.

     The abstract methods defined by this class are to add optional
     bytecode file support.  Not implementing these optional methods (or
     causing them to raise *note NotImplementedError: 36b.) causes the
     loader to only work with source code.  Implementing the methods
     allows the loader to work with source 'and' bytecode files; it does
     not allow for 'sourceless' loading where only bytecode is provided.
     Bytecode files are an optimization to speed up loading by removing
     the parsing step of Python’s compiler, and so no bytecode-specific
     API is exposed.

      -- Metodo: path_stats (path)

          Optional abstract method which returns a *note dict: 183.
          containing metadata about the specified path.  Supported
          dictionary keys are:

             - ‘'mtime'’ (mandatory): an integer or floating-point
               number representing the modification time of the source
               code;

             - ‘'size'’ (optional): the size in bytes of the source
               code.

          Any other keys in the dictionary are ignored, to allow for
          future extensions.  If the path cannot be handled, *note
          OSError: 2c0. is raised.

          Added in version 3.3.

          Cambiato nella versione 3.4: Raise *note OSError: 2c0. instead
          of *note NotImplementedError: 36b.

      -- Metodo: path_mtime (path)

          Optional abstract method which returns the modification time
          for the specified path.

          Deprecato dalla versione 3.3: This method is deprecated in
          favour of *note path_stats(): 1392.  You don’t have to
          implement it, but it is still available for compatibility
          purposes.  Raise *note OSError: 2c0. if the path cannot be
          handled.

          Cambiato nella versione 3.4: Raise *note OSError: 2c0. instead
          of *note NotImplementedError: 36b.

      -- Metodo: set_data (path, data)

          Optional abstract method which writes the specified bytes to a
          file path.  Any intermediate directories which do not exist
          are to be created automatically.

          When writing to the path fails because the path is read-only
          (*note errno.EACCES: 26ef./*note PermissionError: f40.), do
          not propagate the exception.

          Cambiato nella versione 3.4: No longer raises *note
          NotImplementedError: 36b. when called.

      -- Metodo: get_code (fullname)

          Concrete implementation of *note InspectLoader.get_code():
          1157.

      -- Metodo: exec_module (module)

          Concrete implementation of *note Loader.exec_module(): a6c.

          Added in version 3.4.

      -- Metodo: load_module (fullname)

          Concrete implementation of *note Loader.load_module(): a6b.

          Deprecated since version 3.4, will be removed in version 3.15:
          Use *note exec_module(): 1215. instead.

      -- Metodo: get_source (fullname)

          Concrete implementation of *note InspectLoader.get_source():
          115a.

      -- Metodo: is_package (fullname)

          Concrete implementation of *note InspectLoader.is_package():
          4ae2.  A module is determined to be a package if its file path
          (as provided by *note ExecutionLoader.get_filename(): 4ae5.)
          is a file named ‘__init__’ when the file extension is removed
          'and' the module name itself does not end in ‘__init__’.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/importlib/abc.py

   (2) https://peps.python.org/pep-0302/

   (3) https://peps.python.org/pep-0302/

   (4) https://peps.python.org/pep-0302/

   (5) https://peps.python.org/pep-0302/


File: python.info,  Node: importlib machinery – Importers and path hooks,  Next: importlib util – Utility code for importers,  Prev: importlib abc – Abstract base classes related to import,  Up: importlib — The implementation of import

5.31.5.4 ‘importlib.machinery’ – Importers and path hooks
.........................................................

'Source code:' Lib/importlib/machinery.py(1)

__________________________________________________________________

This module contains the various objects that help *note import: 7f9.
find and load modules.

 -- Dati: importlib.machinery.SOURCE_SUFFIXES

     A list of strings representing the recognized file suffixes for
     source modules.

     Added in version 3.3.

 -- Dati: importlib.machinery.DEBUG_BYTECODE_SUFFIXES

     A list of strings representing the file suffixes for non-optimized
     bytecode modules.

     Added in version 3.3.

     Deprecato dalla versione 3.5: Use *note BYTECODE_SUFFIXES: 73b.
     instead.

 -- Dati: importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES

     A list of strings representing the file suffixes for optimized
     bytecode modules.

     Added in version 3.3.

     Deprecato dalla versione 3.5: Use *note BYTECODE_SUFFIXES: 73b.
     instead.

 -- Dati: importlib.machinery.BYTECODE_SUFFIXES

     A list of strings representing the recognized file suffixes for
     bytecode modules (including the leading dot).

     Added in version 3.3.

     Cambiato nella versione 3.5: The value is no longer dependent on
     ‘__debug__’.

 -- Dati: importlib.machinery.EXTENSION_SUFFIXES

     A list of strings representing the recognized file suffixes for
     extension modules.

     Added in version 3.3.

 -- Funzione: importlib.machinery.all_suffixes ()

     Returns a combined list of strings representing all file suffixes
     for modules recognized by the standard import machinery.  This is a
     helper for code which simply needs to know if a filesystem path
     potentially refers to a module without needing any details on the
     kind of module (for example, *note inspect.getmodulename(): f36.).

     Added in version 3.3.

 -- Classe: importlib.machinery.BuiltinImporter

     An *note importer: 242c. for built-in modules.  All known built-in
     modules are listed in *note sys.builtin_module_names: 2031.  This
     class implements the *note importlib.abc.MetaPathFinder: a70. and
     *note importlib.abc.InspectLoader: 1156. ABCs.

     Only class methods are defined by this class to alleviate the need
     for instantiation.

     Cambiato nella versione 3.5: As part of PEP 489(2), the builtin
     importer now implements ‘Loader.create_module()’ and
     ‘Loader.exec_module()’

 -- Classe: importlib.machinery.FrozenImporter

     An *note importer: 242c. for frozen modules.  This class implements
     the *note importlib.abc.MetaPathFinder: a70. and *note
     importlib.abc.InspectLoader: 1156. ABCs.

     Only class methods are defined by this class to alleviate the need
     for instantiation.

     Cambiato nella versione 3.4: Gained ‘create_module()’ and
     ‘exec_module()’ methods.

 -- Classe: importlib.machinery.WindowsRegistryFinder

     *note Finder: 2351. for modules declared in the Windows registry.
     This class implements the *note importlib.abc.MetaPathFinder: a70.
     ABC.

     Only class methods are defined by this class to alleviate the need
     for instantiation.

     Added in version 3.3.

     Deprecato dalla versione 3.6: Use *note site: cc. configuration
     instead.  Future versions of Python may not enable this finder by
     default.

 -- Classe: importlib.machinery.PathFinder

     A *note Finder: 2351. for *note sys.path: 3e4. and package
     ‘__path__’ attributes.  This class implements the *note
     importlib.abc.MetaPathFinder: a70. ABC.

     Only class methods are defined by this class to alleviate the need
     for instantiation.

      -- Metodo: classmethod find_spec (fullname, path=None,
               target=None)

          Class method that attempts to find a *note spec: 234a. for the
          module specified by 'fullname' on *note sys.path: 3e4. or, if
          defined, on 'path'.  For each path entry that is searched,
          *note sys.path_importer_cache: 7fb. is checked.  If a
          non-false object is found then it is used as the *note path
          entry finder: 1273. to look for the module being searched for.
          If no entry is found in *note sys.path_importer_cache: 7fb,
          then *note sys.path_hooks: 1226. is searched for a finder for
          the path entry and, if found, is stored in *note
          sys.path_importer_cache: 7fb. along with being queried about
          the module.  If no finder is ever found then ‘None’ is both
          stored in the cache and returned.

          Added in version 3.4.

          Cambiato nella versione 3.5: If the current working directory
          – represented by an empty string – is no longer valid then
          ‘None’ is returned but no value is cached in *note
          sys.path_importer_cache: 7fb.

      -- Metodo: classmethod invalidate_caches ()

          Calls *note importlib.abc.PathEntryFinder.invalidate_caches():
          4ae0. on all finders stored in *note sys.path_importer_cache:
          7fb. that define the method.  Otherwise entries in *note
          sys.path_importer_cache: 7fb. set to ‘None’ are deleted.

          Cambiato nella versione 3.7: Entries of ‘None’ in *note
          sys.path_importer_cache: 7fb. are deleted.

     Cambiato nella versione 3.4: Calls objects in *note sys.path_hooks:
     1226. with the current working directory for ‘''’ (i.e.  the empty
     string).

 -- Classe: importlib.machinery.FileFinder (path, *loader_details)

     A concrete implementation of *note importlib.abc.PathEntryFinder:
     a71. which caches results from the file system.

     The 'path' argument is the directory for which the finder is in
     charge of searching.

     The 'loader_details' argument is a variable number of 2-item tuples
     each containing a loader and a sequence of file suffixes the loader
     recognizes.  The loaders are expected to be callables which accept
     two arguments of the module’s name and the path to the file found.

     The finder will cache the directory contents as necessary, making
     stat calls for each module search to verify the cache is not
     outdated.  Because cache staleness relies upon the granularity of
     the operating system’s state information of the file system, there
     is a potential race condition of searching for a module, creating a
     new file, and then searching for the module the new file
     represents.  If the operations happen fast enough to fit within the
     granularity of stat calls, then the module search will fail.  To
     prevent this from happening, when you create a module dynamically,
     make sure to call *note importlib.invalidate_caches(): e0c.

     Added in version 3.3.

      -- Attributo: path

          The path the finder will search in.

      -- Metodo: find_spec (fullname, target=None)

          Attempt to find the spec to handle 'fullname' within *note
          path: 4af1.

          Added in version 3.4.

      -- Metodo: invalidate_caches ()

          Clear out the internal cache.

      -- Metodo: classmethod path_hook (*loader_details)

          A class method which returns a closure for use on *note
          sys.path_hooks: 1226.  An instance of *note FileFinder: 1274.
          is returned by the closure using the path argument given to
          the closure directly and 'loader_details' indirectly.

          If the argument to the closure is not an existing directory,
          *note ImportError: 65b. is raised.

 -- Classe: importlib.machinery.SourceFileLoader (fullname, path)

     A concrete implementation of *note importlib.abc.SourceLoader:
     4aeb. by subclassing *note importlib.abc.FileLoader: 1275. and
     providing some concrete implementations of other methods.

     Added in version 3.3.

      -- Attributo: name

          The name of the module that this loader will handle.

      -- Attributo: path

          The path to the source file.

      -- Metodo: is_package (fullname)

          Return ‘True’ if *note path: 4af5. appears to be for a
          package.

      -- Metodo: path_stats (path)

          Concrete implementation of *note
          importlib.abc.SourceLoader.path_stats(): 1392.

      -- Metodo: set_data (path, data)

          Concrete implementation of *note
          importlib.abc.SourceLoader.set_data(): 4aec.

      -- Metodo: load_module (name=None)

          Concrete implementation of *note
          importlib.abc.Loader.load_module(): a6b. where specifying the
          name of the module to load is optional.

          Deprecated since version 3.6, will be removed in version 3.15:
          Use *note importlib.abc.Loader.exec_module(): a6c. instead.

 -- Classe: importlib.machinery.SourcelessFileLoader (fullname, path)

     A concrete implementation of *note importlib.abc.FileLoader: 1275.
     which can import bytecode files (i.e.  no source code files exist).

     Please note that direct use of bytecode files (and thus not source
     code files) inhibits your modules from being usable by all Python
     implementations or new versions of Python which change the bytecode
     format.

     Added in version 3.3.

      -- Attributo: name

          The name of the module the loader will handle.

      -- Attributo: path

          The path to the bytecode file.

      -- Metodo: is_package (fullname)

          Determines if the module is a package based on *note path:
          4afa.

      -- Metodo: get_code (fullname)

          Returns the code object for *note name: 4af9. created from
          *note path: 4afa.

      -- Metodo: get_source (fullname)

          Returns ‘None’ as bytecode files have no source when this
          loader is used.

      -- Metodo: load_module (name=None)

     Concrete implementation of *note
     importlib.abc.Loader.load_module(): a6b. where specifying the name
     of the module to load is optional.

     Deprecated since version 3.6, will be removed in version 3.15: Use
     *note importlib.abc.Loader.exec_module(): a6c. instead.

 -- Classe: importlib.machinery.ExtensionFileLoader (fullname, path)

     A concrete implementation of *note importlib.abc.ExecutionLoader:
     4ae4. for extension modules.

     The 'fullname' argument specifies the name of the module the loader
     is to support.  The 'path' argument is the path to the extension
     module’s file.

     Note that, by default, importing an extension module will fail in
     subinterpreters if it doesn’t implement multi-phase init (see PEP
     489(3)), even if it would otherwise import successfully.

     Added in version 3.3.

     Cambiato nella versione 3.12: Multi-phase init is now required for
     use in subinterpreters.

      -- Attributo: name

          Name of the module the loader supports.

      -- Attributo: path

          Path to the extension module.

      -- Metodo: create_module (spec)

          Creates the module object from the given specification in
          accordance with PEP 489(4).

          Added in version 3.5.

      -- Metodo: exec_module (module)

          Initializes the given module object in accordance with PEP
          489(5).

          Added in version 3.5.

      -- Metodo: is_package (fullname)

          Returns ‘True’ if the file path points to a package’s
          ‘__init__’ module based on *note EXTENSION_SUFFIXES: 73a.

      -- Metodo: get_code (fullname)

          Returns ‘None’ as extension modules lack a code object.

      -- Metodo: get_source (fullname)

          Returns ‘None’ as extension modules do not have source code.

      -- Metodo: get_filename (fullname)

          Returns *note path: 4aff.

          Added in version 3.4.

 -- Classe: importlib.machinery.NamespaceLoader (name, path,
          path_finder)

     A concrete implementation of *note importlib.abc.InspectLoader:
     1156. for namespace packages.  This is an alias for a private class
     and is only made public for introspecting the ‘__loader__’
     attribute on namespace packages:

          >>> from importlib.machinery import NamespaceLoader
          >>> import my_namespace
          >>> isinstance(my_namespace.__loader__, NamespaceLoader)
          True
          >>> import importlib.abc
          >>> isinstance(my_namespace.__loader__, importlib.abc.Loader)
          True

     Added in version 3.11.

 -- Classe: importlib.machinery.ModuleSpec (name, loader, *,
          origin=None, loader_state=None, is_package=None)

     A specification for a module’s import-system-related state.  This
     is typically exposed as the module’s *note __spec__: 234b.
     attribute.  Many of these attributes are also available directly on
     a module: for example, ‘module.__spec__.origin == module.__file__’.
     Note, however, that while the 'values' are usually equivalent, they
     can differ since there is no synchronization between the two
     objects.  For example, it is possible to update the module’s *note
     __file__: 2350. at runtime and this will not be automatically
     reflected in the module’s *note __spec__.origin: 4b05, and vice
     versa.

     Added in version 3.4.

      -- Attributo: name

          The module’s fully qualified name (see *note module.__name__:
          1593.).  The *note finder: 2351. should always set this
          attribute to a non-empty string.

      -- Attributo: loader

          The *note loader: 1a10. used to load the module (see *note
          module.__loader__: 33b.).  The *note finder: 2351. should
          always set this attribute.

      -- Attributo: origin

          The location the *note loader: 1a10. should use to load the
          module (see *note module.__file__: 2350.).  For example, for
          modules loaded from a ‘.py’ file this is the filename.  The
          *note finder: 2351. should always set this attribute to a
          meaningful value for the *note loader: 1a10. to use.  In the
          uncommon case that there is not one (like for namespace
          packages), it should be set to ‘None’.

      -- Attributo: submodule_search_locations

          A (possibly empty) *note sequence: 717. of strings enumerating
          the locations in which a package’s submodules will be found
          (see *note module.__path__: 203e.).  Most of the time there
          will only be a single directory in this list.

          The *note finder: 2351. should set this attribute to a
          sequence, even an empty one, to indicate to the import system
          that the module is a package.  It should be set to ‘None’ for
          non-package modules.  It is set automatically later to a
          special object for namespace packages.

      -- Attributo: loader_state

          The *note finder: 2351. may set this attribute to an object
          containing additional, module-specific data to use when
          loading the module.  Otherwise it should be set to ‘None’.

      -- Attributo: cached

          The filename of a compiled version of the module’s code (see
          *note module.__cached__: 321.).  The *note finder: 2351.
          should always set this attribute but it may be ‘None’ for
          modules that do not need compiled code stored.

      -- Attributo: parent

          (Read-only) The fully qualified name of the package the module
          is in (or the empty string for a top-level module).  See *note
          module.__package__: 323.  If the module is a package then this
          is the same as *note name: 234c.

      -- Attributo: has_location

          ‘True’ if the spec’s *note origin: 4b05. refers to a loadable
          location, ‘False’ otherwise.  This value impacts how ‘origin’
          is interpreted and how the module’s *note __file__: 2350. is
          populated.

 -- Classe: importlib.machinery.AppleFrameworkLoader (name, path)

     A specialization of *note importlib.machinery.ExtensionFileLoader:
     eb0. that is able to load extension modules in Framework format.

     For compatibility with the iOS App Store, 'all' binary modules in
     an iOS app must be dynamic libraries, contained in a framework with
     appropriate metadata, stored in the ‘Frameworks’ folder of the
     packaged app.  There can be only a single binary per framework, and
     there can be no executable binary material outside the Frameworks
     folder.

     To accommodate this requirement, when running on iOS, extension
     module binaries are 'not' packaged as ‘.so’ files on ‘sys.path’,
     but as individual standalone frameworks.  To discover those
     frameworks, this loader is registered against the ‘.fwork’ file
     extension, with a ‘.fwork’ file acting as a placeholder in the
     original location of the binary on ‘sys.path’.  The ‘.fwork’ file
     contains the path of the actual binary in the ‘Frameworks’ folder,
     relative to the app bundle.  To allow for resolving a
     framework-packaged binary back to the original location, the
     framework is expected to contain a ‘.origin’ file that contains the
     location of the ‘.fwork’ file, relative to the app bundle.

     For example, consider the case of an import ‘from foo.bar import
     _whiz’, where ‘_whiz’ is implemented with the binary module
     ‘sources/foo/bar/_whiz.abi3.so’, with ‘sources’ being the location
     registered on ‘sys.path’, relative to the application bundle.  This
     module 'must' be distributed as
     ‘Frameworks/foo.bar._whiz.framework/foo.bar._whiz’ (creating the
     framework name from the full import path of the module), with an
     ‘Info.plist’ file in the ‘.framework’ directory identifying the
     binary as a framework.  The ‘foo.bar._whiz’ module would be
     represented in the original location with a
     ‘sources/foo/bar/_whiz.abi3.fwork’ marker file, containing the path
     ‘Frameworks/foo.bar._whiz/foo.bar._whiz’.  The framework would also
     contain ‘Frameworks/foo.bar._whiz.framework/foo.bar._whiz.origin’,
     containing the path to the ‘.fwork’ file.

     When a module is loaded with this loader, the ‘__file__’ for the
     module will report as the location of the ‘.fwork’ file.  This
     allows code to use the ‘__file__’ of a module as an anchor for file
     system traversal.  However, the spec origin will reference the
     location of the 'actual' binary in the ‘.framework’ folder.

     The Xcode project building the app is responsible for converting
     any ‘.so’ files from wherever they exist in the ‘PYTHONPATH’ into
     frameworks in the ‘Frameworks’ folder (including stripping
     extensions from the module file, the addition of framework
     metadata, and signing the resulting framework), and creating the
     ‘.fwork’ and ‘.origin’ files.  This will usually be done with a
     build step in the Xcode project; see the iOS documentation for
     details on how to construct this build step.

     Added in version 3.13.

     *note Availability: 2128.: iOS.

      -- Attributo: name

          Name of the module the loader supports.

      -- Attributo: path

          Path to the ‘.fwork’ file for the extension module.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/importlib/machinery.py

   (2) https://peps.python.org/pep-0489/

   (3) https://peps.python.org/pep-0489/

   (4) https://peps.python.org/pep-0489/

   (5) https://peps.python.org/pep-0489/


File: python.info,  Node: importlib util – Utility code for importers,  Next: Examples<35>,  Prev: importlib machinery – Importers and path hooks,  Up: importlib — The implementation of import

5.31.5.5 ‘importlib.util’ – Utility code for importers
......................................................

'Source code:' Lib/importlib/util.py(1)

__________________________________________________________________

This module contains the various objects that help in the construction
of an *note importer: 242c.

 -- Dati: importlib.util.MAGIC_NUMBER

     The bytes which represent the bytecode version number.  If you need
     help with loading/writing bytecode then consider *note
     importlib.abc.SourceLoader: 4aeb.

     Added in version 3.4.

 -- Funzione: importlib.util.cache_from_source (path,
          debug_override=None, *, optimization=None)

     Return the PEP 3147(2)/ PEP 488(3) path to the byte-compiled file
     associated with the source 'path'.  For example, if 'path' is
     ‘/foo/bar/baz.py’ the return value would be
     ‘/foo/bar/__pycache__/baz.cpython-32.pyc’ for Python 3.2.  The
     ‘cpython-32’ string comes from the current magic tag (see
     ‘get_tag()’; if ‘sys.implementation.cache_tag’ is not defined then
     *note NotImplementedError: 36b. will be raised).

     The 'optimization' parameter is used to specify the optimization
     level of the bytecode file.  An empty string represents no
     optimization, so ‘/foo/bar/baz.py’ with an 'optimization' of ‘''’
     will result in a bytecode path of
     ‘/foo/bar/__pycache__/baz.cpython-32.pyc’.  ‘None’ causes the
     interpreter’s optimization level to be used.  Any other value’s
     string representation is used, so ‘/foo/bar/baz.py’ with an
     'optimization' of ‘2’ will lead to the bytecode path of
     ‘/foo/bar/__pycache__/baz.cpython-32.opt-2.pyc’.  The string
     representation of 'optimization' can only be alphanumeric, else
     *note ValueError: 2ec. is raised.

     The 'debug_override' parameter is deprecated and can be used to
     override the system’s value for ‘__debug__’.  A ‘True’ value is the
     equivalent of setting 'optimization' to the empty string.  A
     ‘False’ value is the same as setting 'optimization' to ‘1’.  If
     both 'debug_override' an 'optimization' are not ‘None’ then *note
     TypeError: 198. is raised.

     Added in version 3.4.

     Cambiato nella versione 3.5: The 'optimization' parameter was added
     and the 'debug_override' parameter was deprecated.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: importlib.util.source_from_cache (path)

     Given the 'path' to a PEP 3147(4) file name, return the associated
     source code file path.  For example, if 'path' is
     ‘/foo/bar/__pycache__/baz.cpython-32.pyc’ the returned path would
     be ‘/foo/bar/baz.py’.  'path' need not exist, however if it does
     not conform to PEP 3147(5) or PEP 488(6) format, a *note
     ValueError: 2ec. is raised.  If ‘sys.implementation.cache_tag’ is
     not defined, *note NotImplementedError: 36b. is raised.

     Added in version 3.4.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: importlib.util.decode_source (source_bytes)

     Decode the given bytes representing source code and return it as a
     string with universal newlines (as required by *note
     importlib.abc.InspectLoader.get_source(): 115a.).

     Added in version 3.4.

 -- Funzione: importlib.util.resolve_name (name, package)

     Resolve a relative module name to an absolute one.

     If 'name' has no leading dots, then 'name' is simply returned.
     This allows for usage such as ‘importlib.util.resolve_name('sys',
     __spec__.parent)’ without doing a check to see if the 'package'
     argument is needed.

     *note ImportError: 65b. is raised if 'name' is a relative module
     name but 'package' is a false value (e.g.  ‘None’ or the empty
     string).  *note ImportError: 65b. is also raised if a relative name
     would escape its containing package (e.g.  requesting ‘..bacon’
     from within the ‘spam’ package).

     Added in version 3.3.

     Cambiato nella versione 3.9: To improve consistency with import
     statements, raise *note ImportError: 65b. instead of *note
     ValueError: 2ec. for invalid relative import attempts.

 -- Funzione: importlib.util.find_spec (name, package=None)

     Find the *note spec: 234a. for a module, optionally relative to the
     specified 'package' name.  If the module is in *note sys.modules:
     17ce, then ‘sys.modules[name].__spec__’ is returned (unless the
     spec would be ‘None’ or is not set, in which case *note ValueError:
     2ec. is raised).  Otherwise a search using *note sys.meta_path:
     f29. is done.  ‘None’ is returned if no spec is found.

     If 'name' is for a submodule (contains a dot), the parent module is
     automatically imported.

     'name' and 'package' work the same as for ‘import_module()’.

     Added in version 3.4.

     Cambiato nella versione 3.7: Raises *note ModuleNotFoundError: d3f.
     instead of *note AttributeError: 5f0. if 'package' is in fact not a
     package (i.e.  lacks a *note __path__: 203e. attribute).

 -- Funzione: importlib.util.module_from_spec (spec)

     Create a new module based on 'spec' and *note
     spec.loader.create_module: eae.

     If *note spec.loader.create_module: eae. does not return ‘None’,
     then any pre-existing attributes will not be reset.  Also, no *note
     AttributeError: 5f0. will be raised if triggered while accessing
     'spec' or setting an attribute on the module.

     This function is preferred over using *note types.ModuleType: 1016.
     to create a new module as 'spec' is used to set as many
     import-controlled attributes on the module as possible.

     Added in version 3.5.

 -- Funzione: importlib.util.spec_from_loader (name, loader, *,
          origin=None, is_package=None)

     A factory function for creating a *note ModuleSpec: 2255. instance
     based on a loader.  The parameters have the same meaning as they do
     for ModuleSpec.  The function uses available *note loader: 1a10.
     APIs, such as ‘InspectLoader.is_package()’, to fill in any missing
     information on the spec.

     Added in version 3.4.

 -- Funzione: importlib.util.spec_from_file_location (name, location, *,
          loader=None, submodule_search_locations=None)

     A factory function for creating a *note ModuleSpec: 2255. instance
     based on the path to a file.  Missing information will be filled in
     on the spec by making use of loader APIs and by the implication
     that the module will be file-based.

     Added in version 3.4.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- Funzione: importlib.util.source_hash (source_bytes)

     Return the hash of 'source_bytes' as bytes.  A hash-based ‘.pyc’
     file embeds the *note source_hash(): d40. of the corresponding
     source file’s contents in its header.

     Added in version 3.7.

 -- Funzione: importlib.util._incompatible_extension_module_restrictions
          (*, disable_check)

     A context manager that can temporarily skip the compatibility check
     for extension modules.  By default the check is enabled and will
     fail when a single-phase init module is imported in a
     subinterpreter.  It will also fail for a multi-phase init module
     that doesn’t explicitly support a per-interpreter GIL, when
     imported in an interpreter with its own GIL.

     Note that this function is meant to accommodate an unusual case;
     one which is likely to eventually go away.  There’s is a pretty
     good chance this is not what you were looking for.

     You can get the same effect as this function by implementing the
     basic interface of multi-phase init ( PEP 489(7)) and lying about
     support for multiple interpreters (or per-interpreter GIL).

          Avvertimento: Using this function to disable the check can
          lead to unexpected behavior and even crashes.  It should only
          be used during extension module development.

     Added in version 3.12.

 -- Classe: importlib.util.LazyLoader (loader)

     A class which postpones the execution of the loader of a module
     until the module has an attribute accessed.

     This class 'only' works with loaders that define *note
     exec_module(): a6c. as control over what module type is used for
     the module is required.  For those same reasons, the loader’s *note
     create_module(): eae. method must return ‘None’ or a type for which
     its ‘__class__’ attribute can be mutated along with not using *note
     slots: 7f8.  Finally, modules which substitute the object placed
     into *note sys.modules: 17ce. will not work as there is no way to
     properly replace the module references throughout the interpreter
     safely; *note ValueError: 2ec. is raised if such a substitution is
     detected.

          Nota: For projects where startup time is critical, this class
          allows for potentially minimizing the cost of loading a module
          if it is never used.  For projects where startup time is not
          essential then use of this class is 'heavily' discouraged due
          to error messages created during loading being postponed and
          thus occurring out of context.

     Added in version 3.5.

     Cambiato nella versione 3.6: Began calling *note create_module():
     eae, removing the compatibility warning for *note
     importlib.machinery.BuiltinImporter: eaf. and *note
     importlib.machinery.ExtensionFileLoader: eb0.

      -- Metodo: classmethod factory (loader)

          A class method which returns a callable that creates a lazy
          loader.  This is meant to be used in situations where the
          loader is passed by class instead of by instance.

               suffixes = importlib.machinery.SOURCE_SUFFIXES
               loader = importlib.machinery.SourceFileLoader
               lazy_loader = importlib.util.LazyLoader.factory(loader)
               finder = importlib.machinery.FileFinder(path, (lazy_loader, suffixes))

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/importlib/util.py

   (2) https://peps.python.org/pep-3147/

   (3) https://peps.python.org/pep-0488/

   (4) https://peps.python.org/pep-3147/

   (5) https://peps.python.org/pep-3147/

   (6) https://peps.python.org/pep-0488/

   (7) https://peps.python.org/pep-0489/


File: python.info,  Node: Examples<35>,  Prev: importlib util – Utility code for importers,  Up: importlib — The implementation of import

5.31.5.6 Examples
.................

* Menu:

* Importing programmatically::
* Checking if a module can be imported::
* Importing a source file directly::
* Implementing lazy imports::
* Setting up an importer::
* Approximating importlib.import_module(): Approximating importlib import_module.


File: python.info,  Node: Importing programmatically,  Next: Checking if a module can be imported,  Up: Examples<35>

5.31.5.7 Importing programmatically
...................................

To programmatically import a module, use *note
importlib.import_module(): 73d.

     import importlib

     itertools = importlib.import_module('itertools')


File: python.info,  Node: Checking if a module can be imported,  Next: Importing a source file directly,  Prev: Importing programmatically,  Up: Examples<35>

5.31.5.8 Checking if a module can be imported
.............................................

If you need to find out if a module can be imported without actually
doing the import, then you should use *note importlib.util.find_spec():
5af.

Note that if ‘name’ is a submodule (contains a dot), *note
importlib.util.find_spec(): 5af. will import the parent module.

     import importlib.util
     import sys

     # For illustrative purposes.
     name = 'itertools'

     if name in sys.modules:
         print(f"{name!r} already in sys.modules")
     elif (spec := importlib.util.find_spec(name)) is not None:
         # If you chose to perform the actual import ...
         module = importlib.util.module_from_spec(spec)
         sys.modules[name] = module
         spec.loader.exec_module(module)
         print(f"{name!r} has been imported")
     else:
         print(f"can't find the {name!r} module")


File: python.info,  Node: Importing a source file directly,  Next: Implementing lazy imports,  Prev: Checking if a module can be imported,  Up: Examples<35>

5.31.5.9 Importing a source file directly
.........................................

This recipe should be used with caution: it is an approximation of an
import statement where the file path is specified directly, rather than
*note sys.path: 3e4. being searched.  Alternatives should first be
considered first, such as modifying *note sys.path: 3e4. when a proper
module is required, or using *note runpy.run_path(): 4a5. when the
global namespace resulting from running a Python file is appropriate.

To import a Python source file directly from a path, use the following
recipe:

     import importlib.util
     import sys


     def import_from_path(module_name, file_path):
         spec = importlib.util.spec_from_file_location(module_name, file_path)
         module = importlib.util.module_from_spec(spec)
         sys.modules[module_name] = module
         spec.loader.exec_module(module)
         return module


     # For illustrative purposes only (use of `json` is arbitrary).
     import json
     file_path = json.__file__
     module_name = json.__name__

     # Similar outcome as `import json`.
     json = import_from_path(module_name, file_path)


File: python.info,  Node: Implementing lazy imports,  Next: Setting up an importer,  Prev: Importing a source file directly,  Up: Examples<35>

5.31.5.10 Implementing lazy imports
...................................

The example below shows how to implement lazy imports:

     >>> import importlib.util
     >>> import sys
     >>> def lazy_import(name):
     ...     spec = importlib.util.find_spec(name)
     ...     loader = importlib.util.LazyLoader(spec.loader)
     ...     spec.loader = loader
     ...     module = importlib.util.module_from_spec(spec)
     ...     sys.modules[name] = module
     ...     loader.exec_module(module)
     ...     return module
     ...
     >>> lazy_typing = lazy_import("typing")
     >>> #lazy_typing is a real module object,
     >>> #but it is not loaded in memory yet.
     >>> lazy_typing.TYPE_CHECKING
     False


File: python.info,  Node: Setting up an importer,  Next: Approximating importlib import_module,  Prev: Implementing lazy imports,  Up: Examples<35>

5.31.5.11 Setting up an importer
................................

For deep customizations of import, you typically want to implement an
*note importer: 242c.  This means managing both the *note finder: 2351.
and *note loader: 1a10. side of things.  For finders there are two
flavours to choose from depending on your needs: a *note meta path
finder: 1272. or a *note path entry finder: 1273.  The former is what
you would put on *note sys.meta_path: f29. while the latter is what you
create using a *note path entry hook: 243d. on *note sys.path_hooks:
1226. which works with *note sys.path: 3e4. entries to potentially
create a finder.  This example will show you how to register your own
importers so that import will use them (for creating an importer for
yourself, read the documentation for the appropriate classes defined
within this package):

     import importlib.machinery
     import sys

     # For illustrative purposes only.
     SpamMetaPathFinder = importlib.machinery.PathFinder
     SpamPathEntryFinder = importlib.machinery.FileFinder
     loader_details = (importlib.machinery.SourceFileLoader,
                       importlib.machinery.SOURCE_SUFFIXES)

     # Setting up a meta path finder.
     # Make sure to put the finder in the proper location in the list in terms of
     # priority.
     sys.meta_path.append(SpamMetaPathFinder)

     # Setting up a path entry finder.
     # Make sure to put the path hook in the proper location in the list in terms
     # of priority.
     sys.path_hooks.append(SpamPathEntryFinder.path_hook(loader_details))


File: python.info,  Node: Approximating importlib import_module,  Prev: Setting up an importer,  Up: Examples<35>

5.31.5.12 Approximating ‘importlib.import_module()’
...................................................

Import itself is implemented in Python code, making it possible to
expose most of the import machinery through importlib.  The following
helps illustrate the various APIs that importlib exposes by providing an
approximate implementation of *note importlib.import_module(): 73d.:

     import importlib.util
     import sys

     def import_module(name, package=None):
         """An approximate implementation of import."""
         absolute_name = importlib.util.resolve_name(name, package)
         try:
             return sys.modules[absolute_name]
         except KeyError:
             pass

         path = None
         if '.' in absolute_name:
             parent_name, _, child_name = absolute_name.rpartition('.')
             parent_module = import_module(parent_name)
             path = parent_module.__spec__.submodule_search_locations
         for finder in sys.meta_path:
             spec = finder.find_spec(absolute_name, path)
             if spec is not None:
                 break
         else:
             msg = f'No module named {absolute_name!r}'
             raise ModuleNotFoundError(msg, name=absolute_name)
         module = importlib.util.module_from_spec(spec)
         sys.modules[absolute_name] = module
         spec.loader.exec_module(module)
         if path is not None:
             setattr(parent_module, child_name, module)
         return module


File: python.info,  Node: importlib resources – Package resource reading opening and access,  Next: importlib resources abc – Abstract base classes for resources,  Prev: importlib — The implementation of import,  Up: Importing Modules

5.31.6 ‘importlib.resources’ – Package resource reading, opening and access
---------------------------------------------------------------------------

'Source code:' Lib/importlib/resources/__init__.py(1)

__________________________________________________________________

Added in version 3.7.

This module leverages Python’s import system to provide access to
'resources' within 'packages'.

«Resources» are file-like resources associated with a module or package
in Python.  The resources may be contained directly in a package, within
a subdirectory contained in that package, or adjacent to modules outside
a package.  Resources may be text or binary.  As a result, a package’s
Python module sources (.py), compilation artifacts (pycache), and
installation artifacts (like *note reserved filenames: 32b. in
directories) are technically de-facto resources of that package.  In
practice, however, resources are primarily those non-Python artifacts
exposed specifically by the package author.

Resources can be opened or read in either binary or text mode.

Resources are roughly akin to files inside directories, though it’s
important to keep in mind that this is just a metaphor.  Resources and
packages 'do not' have to exist as physical files and directories on the
file system: for example, a package and its resources can be imported
from a zip file using *note zipimport: 138.

     Nota: This module provides functionality similar to
     pkg_resources(2) Basic Resource Access(3) without the performance
     overhead of that package.  This makes reading resources included in
     packages easier, with more stable and consistent semantics.

     The standalone backport of this module provides more information on
     using importlib.resources(4) and migrating from pkg_resources to
     importlib.resources(5).

*note Loaders: 10c9. that wish to support resource reading should
implement a ‘get_resource_reader(fullname)’ method as specified by *note
importlib.resources.abc.ResourceReader: 4ae1.

 -- Classe: importlib.resources.Anchor

     Represents an anchor for resources, either a *note module object:
     1016. or a module name as a string.  Defined as ‘Union[str,
     ModuleType]’.

 -- Funzione: importlib.resources.files (anchor: Anchor | None = None)

     Returns a *note Traversable: 2fa. object representing the resource
     container (think directory) and its resources (think files).  A
     Traversable may contain other containers (think subdirectories).

     'anchor' is an optional *note Anchor: 4b18.  If the anchor is a
     package, resources are resolved from that package.  If a module,
     resources are resolved adjacent to that module (in the same package
     or the package root).  If the anchor is omitted, the caller’s
     module is used.

     Added in version 3.9.

     Cambiato nella versione 3.12: 'package' parameter was renamed to
     'anchor'.  'anchor' can now be a non-package module and if omitted
     will default to the caller’s module.  'package' is still accepted
     for compatibility but will raise a *note DeprecationWarning: 1a3.
     Consider passing the anchor positionally or using
     ‘importlib_resources >= 5.10’ for a compatible interface on older
     Pythons.

 -- Funzione: importlib.resources.as_file (traversable)

     Given a *note Traversable: 2fa. object representing a file or
     directory, typically from *note importlib.resources.files(): 6b7,
     return a context manager for use in a *note with: 186. statement.
     The context manager provides a *note pathlib.Path: 266. object.

     Exiting the context manager cleans up any temporary file or
     directory created when the resource was extracted from e.g.  a zip
     file.

     Use ‘as_file’ when the Traversable methods (‘read_text’, etc) are
     insufficient and an actual file or directory on the file system is
     required.

     Added in version 3.9.

     Cambiato nella versione 3.12: Added support for 'traversable'
     representing a directory.

* Menu:

* Functional API::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/importlib/resources/__init__.py

   (2) https://setuptools.readthedocs.io/en/latest/pkg_resources.html

   (3) 
https://setuptools.readthedocs.io/en/latest/pkg_resources.html#basic-resource-access

   (4) https://importlib-resources.readthedocs.io/en/latest/using.html

   (5) 
https://importlib-resources.readthedocs.io/en/latest/migration.html


File: python.info,  Node: Functional API,  Up: importlib resources – Package resource reading opening and access

5.31.6.1 Functional API
.......................

A set of simplified, backwards-compatible helpers is available.  These
allow common operations in a single function call.

For all the following functions:

   - 'anchor' is an *note Anchor: 4b18, as in *note files(): 6b7.
     Unlike in ‘files’, it may not be omitted.

   - 'path_names' are components of a resource’s path name, relative to
     the anchor.  For example, to get the text of resource named
     ‘info.txt’, use:

          importlib.resources.read_text(my_module, "info.txt")

     Like *note Traversable.joinpath: 2fa, The individual components
     should use forward slashes (‘/’) as path separators.  For example,
     the following are equivalent:

          importlib.resources.read_binary(my_module, "pics/painting.png")
          importlib.resources.read_binary(my_module, "pics", "painting.png")

     For backward compatibility reasons, functions that read text
     require an explicit 'encoding' argument if multiple 'path_names'
     are given.  For example, to get the text of ‘info/chapter1.txt’,
     use:

          importlib.resources.read_text(my_module, "info", "chapter1.txt",
                                        encoding='utf-8')

 -- Funzione: importlib.resources.open_binary (anchor, *path_names)

     Open the named resource for binary reading.

     See *note the introduction: 4b1a. for details on 'anchor' and
     'path_names'.

     This function returns a *note BinaryIO: 23a. object, that is, a
     binary stream open for reading.

     This function is roughly equivalent to:

          files(anchor).joinpath(*path_names).open('rb')

     Cambiato nella versione 3.13: Multiple 'path_names' are accepted.

 -- Funzione: importlib.resources.open_text (anchor, *path_names,
          encoding='utf-8', errors='strict')

     Open the named resource for text reading.  By default, the contents
     are read as strict UTF-8.

     See *note the introduction: 4b1a. for details on 'anchor' and
     'path_names'.  'encoding' and 'errors' have the same meaning as in
     built-in *note open(): 316.

     For backward compatibility reasons, the 'encoding' argument must be
     given explicitly if there are multiple 'path_names'.  This
     limitation is scheduled to be removed in Python 3.15.

     This function returns a *note TextIO: 239. object, that is, a text
     stream open for reading.

     This function is roughly equivalent to:

          files(anchor).joinpath(*path_names).open('r', encoding=encoding)

     Cambiato nella versione 3.13: Multiple 'path_names' are accepted.
     'encoding' and 'errors' must be given as keyword arguments.

 -- Funzione: importlib.resources.read_binary (anchor, *path_names)

     Read and return the contents of the named resource as *note bytes:
     192.

     See *note the introduction: 4b1a. for details on 'anchor' and
     'path_names'.

     This function is roughly equivalent to:

          files(anchor).joinpath(*path_names).read_bytes()

     Cambiato nella versione 3.13: Multiple 'path_names' are accepted.

 -- Funzione: importlib.resources.read_text (anchor, *path_names,
          encoding='utf-8', errors='strict')

     Read and return the contents of the named resource as *note str:
     169.  By default, the contents are read as strict UTF-8.

     See *note the introduction: 4b1a. for details on 'anchor' and
     'path_names'.  'encoding' and 'errors' have the same meaning as in
     built-in *note open(): 316.

     For backward compatibility reasons, the 'encoding' argument must be
     given explicitly if there are multiple 'path_names'.  This
     limitation is scheduled to be removed in Python 3.15.

     This function is roughly equivalent to:

          files(anchor).joinpath(*path_names).read_text(encoding=encoding)

     Cambiato nella versione 3.13: Multiple 'path_names' are accepted.
     'encoding' and 'errors' must be given as keyword arguments.

 -- Funzione: importlib.resources.path (anchor, *path_names)

     Provides the path to the 'resource' as an actual file system path.
     This function returns a context manager for use in a *note with:
     186. statement.  The context manager provides a *note pathlib.Path:
     266. object.

     Exiting the context manager cleans up any temporary files created,
     e.g.  when the resource needs to be extracted from a zip file.

     For example, the *note stat(): a26. method requires an actual file
     system path; it can be used like this:

          with importlib.resources.path(anchor, "resource.txt") as fspath:
              result = fspath.stat()

     See *note the introduction: 4b1a. for details on 'anchor' and
     'path_names'.

     This function is roughly equivalent to:

          as_file(files(anchor).joinpath(*path_names))

     Cambiato nella versione 3.13: Multiple 'path_names' are accepted.
     'encoding' and 'errors' must be given as keyword arguments.

 -- Funzione: importlib.resources.is_resource (anchor, *path_names)

     Return ‘True’ if the named resource exists, otherwise ‘False’.
     This function does not consider directories to be resources.

     See *note the introduction: 4b1a. for details on 'anchor' and
     'path_names'.

     This function is roughly equivalent to:

          files(anchor).joinpath(*path_names).is_file()

     Cambiato nella versione 3.13: Multiple 'path_names' are accepted.

 -- Funzione: importlib.resources.contents (anchor, *path_names)

     Return an iterable over the named items within the package or path.
     The iterable returns names of resources (e.g.  files) and
     non-resources (e.g.  directories) as *note str: 169.  The iterable
     does not recurse into subdirectories.

     See *note the introduction: 4b1a. for details on 'anchor' and
     'path_names'.

     This function is roughly equivalent to:

          for resource in files(anchor).joinpath(*path_names).iterdir():
              yield resource.name

     Deprecato dalla versione 3.11: Prefer ‘iterdir()’ as above, which
     offers more control over the results and richer functionality.


File: python.info,  Node: importlib resources abc – Abstract base classes for resources,  Next: importlib metadata – Accessing package metadata,  Prev: importlib resources – Package resource reading opening and access,  Up: Importing Modules

5.31.7 ‘importlib.resources.abc’ – Abstract base classes for resources
----------------------------------------------------------------------

'Source code:' Lib/importlib/resources/abc.py(1)

__________________________________________________________________

Added in version 3.11.

 -- Classe: importlib.resources.abc.ResourceReader

     'Superseded by TraversableResources'

     An *note abstract base class: 13be. to provide the ability to read
     'resources'.

     From the perspective of this ABC, a 'resource' is a binary artifact
     that is shipped within a package.  Typically this is something like
     a data file that lives next to the ‘__init__.py’ file of the
     package.  The purpose of this class is to help abstract out the
     accessing of such data files so that it does not matter if the
     package and its data file(s) are stored e.g.  in a zip file versus
     on the file system.

     For any of methods of this class, a 'resource' argument is expected
     to be a *note path-like object: 5a1. which represents conceptually
     just a file name.  This means that no subdirectory paths should be
     included in the 'resource' argument.  This is because the location
     of the package the reader is for, acts as the «directory».  Hence
     the metaphor for directories and file names is packages and
     resources, respectively.  This is also why instances of this class
     are expected to directly correlate to a specific package (instead
     of potentially representing multiple packages or a module).

     Loaders that wish to support resource reading are expected to
     provide a method called ‘get_resource_reader(fullname)’ which
     returns an object implementing this ABC’s interface.  If the module
     specified by fullname is not a package, this method should return
     *note None: 886.  An object compatible with this ABC should only be
     returned when the specified module is a package.

     Deprecato dalla versione 3.12: Use *note
     importlib.resources.abc.TraversableResources: 2f9. instead.

      -- Metodo: abstractmethod open_resource (resource)

          Returns an opened, *note file-like object: 1794. for binary
          reading of the 'resource'.

          If the resource cannot be found, *note FileNotFoundError: 264.
          is raised.

      -- Metodo: abstractmethod resource_path (resource)

          Returns the file system path to the 'resource'.

          If the resource does not concretely exist on the file system,
          raise *note FileNotFoundError: 264.

      -- Metodo: abstractmethod is_resource (path)

          Returns ‘True’ if the named 'path' is considered a resource.
          *note FileNotFoundError: 264. is raised if 'path' does not
          exist.

          Cambiato nella versione 3.10: The argument 'name' was renamed
          to 'path'.

      -- Metodo: abstractmethod contents ()

          Returns an *note iterable: 142f. of strings over the contents
          of the package.  Do note that it is not required that all
          names returned by the iterator be actual resources, e.g.  it
          is acceptable to return names for which *note is_resource():
          4b20. would be false.

          Allowing non-resource names to be returned is to allow for
          situations where how a package and its resources are stored
          are known a priori and the non-resource names would be useful.
          For instance, returning subdirectory names is allowed so that
          when it is known that the package and resources are stored on
          the file system then those subdirectory names can be used
          directly.

          The abstract method returns an iterable of no items.

 -- Classe: importlib.resources.abc.Traversable

     An object with a subset of *note pathlib.Path: 266. methods
     suitable for traversing directories and opening files.

     For a representation of the object on the file-system, use *note
     importlib.resources.as_file(): 6b6.

      -- Attributo: name

          Abstract.  The base name of this object without any parent
          references.

      -- Metodo: abstractmethod iterdir ()

          Yield Traversable objects in self.

      -- Metodo: abstractmethod is_dir ()

          Return ‘True’ if self is a directory.

      -- Metodo: abstractmethod is_file ()

          Return ‘True’ if self is a file.

      -- Metodo: abstractmethod joinpath (*pathsegments)

          Traverse directories according to 'pathsegments' and return
          the result as ‘Traversable’.

          Each 'pathsegments' argument may contain multiple names
          separated by forward slashes (‘/’, ‘posixpath.sep’ ).  For
          example, the following are equivalent:

               files.joinpath('subdir', 'subsuddir', 'file.txt')
               files.joinpath('subdir/subsuddir/file.txt')

          Note that some ‘Traversable’ implementations might not be
          updated to the latest version of the protocol.  For
          compatibility with such implementations, provide a single
          argument without path separators to each call to ‘joinpath’.
          For example:

               files.joinpath('subdir').joinpath('subsubdir').joinpath('file.txt')

          Cambiato nella versione 3.11: ‘joinpath’ accepts multiple
          'pathsegments', and these segments may contain forward slashes
          as path separators.  Previously, only a single 'child'
          argument was accepted.

      -- Metodo: abstractmethod __truediv__ (child)

          Return Traversable child in self.  Equivalent to
          ‘joinpath(child)’.

      -- Metodo: abstractmethod open (mode='r', *args, **kwargs)

          'mode' may be “r” or “rb” to open as text or binary.  Return a
          handle suitable for reading (same as *note pathlib.Path.open:
          2c20.).

          When opening as text, accepts encoding parameters such as
          those accepted by *note io.TextIOWrapper: 9c0.

      -- Metodo: read_bytes ()

          Read contents of self as bytes.

      -- Metodo: read_text (encoding=None)

          Read contents of self as text.

 -- Classe: importlib.resources.abc.TraversableResources

     An abstract base class for resource readers capable of serving the
     *note importlib.resources.files(): 6b7. interface.  Subclasses
     *note ResourceReader: 4ae1. and provides concrete implementations
     of the ‘ResourceReader’’s abstract methods.  Therefore, any loader
     supplying ‘TraversableResources’ also supplies ‘ResourceReader’.

     Loaders that wish to support resource reading are expected to
     implement this interface.

      -- Metodo: abstractmethod files ()

          Returns a *note importlib.resources.abc.Traversable: 2fa.
          object for the loaded package.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/importlib/resources/abc.py


File: python.info,  Node: importlib metadata – Accessing package metadata,  Next: The initialization of the sys path module search path,  Prev: importlib resources abc – Abstract base classes for resources,  Up: Importing Modules

5.31.8 ‘importlib.metadata’ – Accessing package metadata
--------------------------------------------------------

Added in version 3.8.

Cambiato nella versione 3.10: ‘importlib.metadata’ is no longer
provisional.

'Source code:' Lib/importlib/metadata/__init__.py(1)

‘importlib.metadata’ is a library that provides access to the metadata
of an installed Distribution Package(2), such as its entry points or its
top-level names (Import Package(3)s, modules, if any).  Built in part on
Python’s import system, this library intends to replace similar
functionality in the entry point API(4) and metadata API(5) of
‘pkg_resources’.  Along with *note importlib.resources: 7f, this package
can eliminate the need to use the older and less efficient
‘pkg_resources’ package.

‘importlib.metadata’ operates on third-party 'distribution packages'
installed into Python’s ‘site-packages’ directory via tools such as
pip(6).  Specifically, it works with distributions with discoverable
‘dist-info’ or ‘egg-info’ directories, and metadata defined by the Core
metadata specifications(7).

     Importante: These are 'not' necessarily equivalent to or correspond
     1:1 with the top-level 'import package' names that can be imported
     inside Python code.  One 'distribution package' can contain
     multiple 'import packages' (and single modules), and one top-level
     'import package' may map to multiple 'distribution packages' if it
     is a namespace package.  You can use *note
     packages_distributions(): a13. to get a mapping between them.

By default, distribution metadata can live on the file system or in zip
archives on *note sys.path: 3e4.  Through an extension mechanism, the
metadata can live almost anywhere.

Vedi anche
..........

‘https://importlib-metadata.readthedocs.io/’

     The documentation for ‘importlib_metadata’, which supplies a
     backport of ‘importlib.metadata’.  This includes an API
     reference(8) for this module’s classes and functions, as well as a
     migration guide(9) for existing users of ‘pkg_resources’.

* Menu:

* Overview: Overview<3>.
* Functional API: Functional API<2>.
* Distributions::
* Distribution Discovery::
* Implementing Custom Providers::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/importlib/metadata/__init__.py

   (2) 
https://packaging.python.org/en/latest/glossary/#term-Distribution-Package

   (3) 
https://packaging.python.org/en/latest/glossary/#term-Import-Package

   (4) 
https://setuptools.readthedocs.io/en/latest/pkg_resources.html#entry-points

   (5) 
https://setuptools.readthedocs.io/en/latest/pkg_resources.html#metadata-api

   (6) https://pypi.org/project/pip/

   (7) 
https://packaging.python.org/en/latest/specifications/core-metadata/#core-metadata

   (8) https://importlib-metadata.readthedocs.io/en/latest/api.html

   (9) 
https://importlib-metadata.readthedocs.io/en/latest/migration.html


File: python.info,  Node: Overview<3>,  Next: Functional API<2>,  Up: importlib metadata – Accessing package metadata

5.31.8.1 Overview
.................

Let’s say you wanted to get the version string for a Distribution
Package(1) you’ve installed using ‘pip’.  We start by creating a virtual
environment and installing something into it:

     $ python -m venv example
     $ source example/bin/activate
     (example) $ python -m pip install wheel

You can get the version string for ‘wheel’ by running the following:

     (example) $ python
     >>> from importlib.metadata import version
     >>> version('wheel')
     '0.32.3'

You can also get a collection of entry points selectable by properties
of the EntryPoint (typically “group” or “name”), such as
‘console_scripts’, ‘distutils.commands’ and others.  Each group contains
a collection of *note EntryPoint: 589. objects.

You can get the *note metadata for a distribution: 4b31.:

     >>> list(metadata('wheel'))
     ['Metadata-Version', 'Name', 'Version', 'Summary', 'Home-page', 'Author', 'Author-email', 'Maintainer', 'Maintainer-email', 'License', 'Project-URL', 'Project-URL', 'Project-URL', 'Keywords', 'Platform', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Requires-Python', 'Provides-Extra', 'Requires-Dist', 'Requires-Dist']

You can also get a *note distribution’s version number: 4b32, list its
*note constituent files: 4b33, and get a list of the distribution’s
*note Distribution requirements: 4b34.

 -- Eccezione: importlib.metadata.PackageNotFoundError

     Subclass of *note ModuleNotFoundError: d3f. raised by several
     functions in this module when queried for a distribution package
     which is not installed in the current Python environment.

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/glossary/#term-Distribution-Package


File: python.info,  Node: Functional API<2>,  Next: Distributions,  Prev: Overview<3>,  Up: importlib metadata – Accessing package metadata

5.31.8.2 Functional API
.......................

This package provides the following functionality via its public API.

* Menu:

* Entry points::
* Distribution metadata::
* Distribution versions::
* Distribution files::
* Distribution requirements::
* Mapping import to distribution packages::


File: python.info,  Node: Entry points,  Next: Distribution metadata,  Up: Functional API<2>

5.31.8.3 Entry points
.....................

 -- Funzione: importlib.metadata.entry_points (**select_params)

     Returns a *note EntryPoints: 4b39. instance describing entry points
     for the current environment.  Any given keyword parameters are
     passed to the ‘select()’ method for comparison to the attributes of
     the individual entry point definitions.

     Note: it is not currently possible to query for entry points based
     on their ‘EntryPoint.dist’ attribute (as different ‘Distribution’
     instances do not currently compare equal, even if they have the
     same attributes)

 -- Classe: importlib.metadata.EntryPoints

     Details of a collection of installed entry points.

     Also provides a ‘.groups’ attribute that reports all identified
     entry point groups, and a ‘.names’ attribute that reports all
     identified entry point names.

 -- Classe: importlib.metadata.EntryPoint

     Details of an installed entry point.

     Each ‘EntryPoint’ instance has ‘.name’, ‘.group’, and ‘.value’
     attributes and a ‘.load()’ method to resolve the value.  There are
     also ‘.module’, ‘.attr’, and ‘.extras’ attributes for getting the
     components of the ‘.value’ attribute, and ‘.dist’ for obtaining
     information regarding the distribution package that provides the
     entry point.

Query all entry points:

     >>> eps = entry_points()

The ‘entry_points()’ function returns a ‘EntryPoints’ object, a
collection of all ‘EntryPoint’ objects with ‘names’ and ‘groups’
attributes for convenience:

     >>> sorted(eps.groups)
     ['console_scripts', 'distutils.commands', 'distutils.setup_keywords', 'egg_info.writers', 'setuptools.installation']

‘EntryPoints’ has a ‘select()’ method to select entry points matching
specific properties.  Select entry points in the ‘console_scripts’
group:

     >>> scripts = eps.select(group='console_scripts')

Equivalently, since ‘entry_points()’ passes keyword arguments through to
select:

     >>> scripts = entry_points(group='console_scripts')

Pick out a specific script named «wheel» (found in the wheel project):

     >>> 'wheel' in scripts.names
     True
     >>> wheel = scripts['wheel']

Equivalently, query for that entry point during selection:

     >>> (wheel,) = entry_points(group='console_scripts', name='wheel')
     >>> (wheel,) = entry_points().select(group='console_scripts', name='wheel')

Inspect the resolved entry point:

     >>> wheel
     EntryPoint(name='wheel', value='wheel.cli:main', group='console_scripts')
     >>> wheel.module
     'wheel.cli'
     >>> wheel.attr
     'main'
     >>> wheel.extras
     []
     >>> main = wheel.load()
     >>> main
     <function main at 0x103528488>

The ‘group’ and ‘name’ are arbitrary values defined by the package
author and usually a client will wish to resolve all entry points for a
particular group.  Read the setuptools docs(1) for more information on
entry points, their definition, and usage.

Cambiato nella versione 3.12: The «selectable» entry points were
introduced in ‘importlib_metadata’ 3.6 and Python 3.10.  Prior to those
changes, ‘entry_points’ accepted no parameters and always returned a
dictionary of entry points, keyed by group.  With ‘importlib_metadata’
5.0 and Python 3.12, ‘entry_points’ always returns an ‘EntryPoints’
object.  See backports.entry_points_selectable(2) for compatibility
options.

Cambiato nella versione 3.13: ‘EntryPoint’ objects no longer present a
tuple-like interface (*note __getitem__(): 588.).

   ---------- Footnotes ----------

   (1) https://setuptools.pypa.io/en/latest/userguide/entry_point.html

   (2) https://pypi.org/project/backports.entry_points_selectable/


File: python.info,  Node: Distribution metadata,  Next: Distribution versions,  Prev: Entry points,  Up: Functional API<2>

5.31.8.4 Distribution metadata
..............................

 -- Funzione: importlib.metadata.metadata (distribution_name)

     Return the distribution metadata corresponding to the named
     distribution package as a *note PackageMetadata: 4b3d. instance.

     Raises *note PackageNotFoundError: 4b35. if the named distribution
     package is not installed in the current Python environment.

 -- Classe: importlib.metadata.PackageMetadata

     A concrete implementation of the PackageMetadata protocol(1).

     In addition to providing the defined protocol methods and
     attributes, subscripting the instance is equivalent to calling the
     ‘get()’ method.

Every Distribution Package(2) includes some metadata, which you can
extract using the ‘metadata()’ function:

     >>> wheel_metadata = metadata('wheel')

The keys of the returned data structure name the metadata keywords, and
the values are returned unparsed from the distribution metadata:

     >>> wheel_metadata['Requires-Python']
     '>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*'

*note PackageMetadata: 4b3d. also presents a ‘json’ attribute that
returns all the metadata in a JSON-compatible form per PEP 566(3):

     >>> wheel_metadata.json['requires_python']
     '>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*'

The full set of available metadata is not described here.  See the PyPA
Core metadata specification(4) for additional details.

Cambiato nella versione 3.10: The ‘Description’ is now included in the
metadata when presented through the payload.  Line continuation
characters have been removed.

The ‘json’ attribute was added.

   ---------- Footnotes ----------

   (1) 
https://importlib-metadata.readthedocs.io/en/latest/api.html#importlib_metadata.PackageMetadata

   (2) 
https://packaging.python.org/en/latest/glossary/#term-Distribution-Package

   (3) https://peps.python.org/pep-0566/

   (4) 
https://packaging.python.org/en/latest/specifications/core-metadata/#core-metadata


File: python.info,  Node: Distribution versions,  Next: Distribution files,  Prev: Distribution metadata,  Up: Functional API<2>

5.31.8.5 Distribution versions
..............................

 -- Funzione: importlib.metadata.version (distribution_name)

     Return the installed distribution package version(1) for the named
     distribution package.

     Raises *note PackageNotFoundError: 4b35. if the named distribution
     package is not installed in the current Python environment.

The ‘version()’ function is the quickest way to get a Distribution
Package(2)’s version number, as a string:

     >>> version('wheel')
     '0.32.3'

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/specifications/core-metadata/#version

   (2) 
https://packaging.python.org/en/latest/glossary/#term-Distribution-Package


File: python.info,  Node: Distribution files,  Next: Distribution requirements,  Prev: Distribution versions,  Up: Functional API<2>

5.31.8.6 Distribution files
...........................

 -- Funzione: importlib.metadata.files (distribution_name)

     Return the full set of files contained within the named
     distribution package.

     Raises *note PackageNotFoundError: 4b35. if the named distribution
     package is not installed in the current Python environment.

     Returns *note None: 886. if the distribution is found but the
     installation database records reporting the files associated with
     the distribution package are missing.

 -- Classe: importlib.metadata.PackagePath

     A *note pathlib.PurePath: 6ce. derived object with additional
     ‘dist’, ‘size’, and ‘hash’ properties corresponding to the
     distribution package’s installation metadata for that file.

The ‘files()’ function takes a Distribution Package(1) name and returns
all of the files installed by this distribution.  Each file is reported
as a *note PackagePath: 4b41. instance.  For example:

     >>> util = [p for p in files('wheel') if 'util.py' in str(p)][0]
     >>> util
     PackagePath('wheel/util.py')
     >>> util.size
     859
     >>> util.dist
     <importlib.metadata._hooks.PathDistribution object at 0x101e0cef0>
     >>> util.hash
     <FileHash mode: sha256 value: bYkw5oMccfazVCoYQwKkkemoVyMAFoR34mmKBx8R1NI>

Once you have the file, you can also read its contents:

     >>> print(util.read_text())
     import base64
     import sys
     ...
     def as_bytes(s):
         if isinstance(s, text_type):
             return s.encode('utf-8')
         return s

You can also use the ‘locate()’ method to get the absolute path to the
file:

     >>> util.locate()
     PosixPath('/home/gustav/example/lib/site-packages/wheel/util.py')

In the case where the metadata file listing files (‘RECORD’ or
‘SOURCES.txt’) is missing, ‘files()’ will return *note None: 886.  The
caller may wish to wrap calls to ‘files()’ in always_iterable(2) or
otherwise guard against this condition if the target distribution is not
known to have the metadata present.

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/glossary/#term-Distribution-Package

   (2) 
https://more-itertools.readthedocs.io/en/stable/api.html#more_itertools.always_iterable


File: python.info,  Node: Distribution requirements,  Next: Mapping import to distribution packages,  Prev: Distribution files,  Up: Functional API<2>

5.31.8.7 Distribution requirements
..................................

 -- Funzione: importlib.metadata.requires (distribution_name)

     Return the declared dependency specifiers for the named
     distribution package.

     Raises *note PackageNotFoundError: 4b35. if the named distribution
     package is not installed in the current Python environment.

To get the full set of requirements for a Distribution Package(1), use
the ‘requires()’ function:

     >>> requires('wheel')
     ["pytest (>=3.0.0) ; extra == 'test'", "pytest-cov ; extra == 'test'"]

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/glossary/#term-Distribution-Package


File: python.info,  Node: Mapping import to distribution packages,  Prev: Distribution requirements,  Up: Functional API<2>

5.31.8.8 Mapping import to distribution packages
................................................

 -- Funzione: importlib.metadata.packages_distributions ()

     Return a mapping from the top level module and import package names
     found via *note sys.meta_path: f29. to the names of the
     distribution packages (if any) that provide the corresponding
     files.

     To allow for namespace packages (which may have members provided by
     multiple distribution packages), each top level import name maps to
     a list of distribution names rather than mapping directly to a
     single name.

A convenience method to resolve the Distribution Package(1) name (or
names, in the case of a namespace package) that provide each importable
top-level Python module or Import Package(2):

     >>> packages_distributions()
     {'importlib_metadata': ['importlib-metadata'], 'yaml': ['PyYAML'], 'jaraco': ['jaraco.classes', 'jaraco.functools'], ...}

Some editable installs, do not supply top-level names(3), and thus this
function is not reliable with such installs.

Added in version 3.10.

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/glossary/#term-Distribution-Package

   (2) 
https://packaging.python.org/en/latest/glossary/#term-Import-Package

   (3) https://github.com/pypa/packaging-problems/issues/609


File: python.info,  Node: Distributions,  Next: Distribution Discovery,  Prev: Functional API<2>,  Up: importlib metadata – Accessing package metadata

5.31.8.9 Distributions
......................

 -- Funzione: importlib.metadata.distribution (distribution_name)

     Return a *note Distribution: 4b49. instance describing the named
     distribution package.

     Raises *note PackageNotFoundError: 4b35. if the named distribution
     package is not installed in the current Python environment.

 -- Classe: importlib.metadata.Distribution

     Details of an installed distribution package.

     Note: different ‘Distribution’ instances do not currently compare
     equal, even if they relate to the same installed distribution and
     accordingly have the same attributes.

While the module level API described above is the most common and
convenient usage, you can get all of that information from the
‘Distribution’ class.  ‘Distribution’ is an abstract object that
represents the metadata for a Python Distribution Package(1).  You can
get the concrete ‘Distribution’ subclass instance for an installed
distribution package by calling the *note distribution(): 4b48.
function:

     >>> from importlib.metadata import distribution
     >>> dist = distribution('wheel')
     >>> type(dist)
     <class 'importlib.metadata.PathDistribution'>

Thus, an alternative way to get the version number is through the
‘Distribution’ instance:

     >>> dist.version
     '0.32.3'

There are all kinds of additional metadata available on ‘Distribution’
instances:

     >>> dist.metadata['Requires-Python']
     '>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*'
     >>> dist.metadata['License']
     'MIT'

For editable packages, an ‘origin’ property may present PEP 610(2)
metadata:

     >>> dist.origin.url
     'file:///path/to/wheel-0.32.3.editable-py3-none-any.whl'

The full set of available metadata is not described here.  See the PyPA
Core metadata specification(3) for additional details.

Added in version 3.13: The ‘.origin’ property was added.

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/glossary/#term-Distribution-Package

   (2) https://peps.python.org/pep-0610/

   (3) 
https://packaging.python.org/en/latest/specifications/core-metadata/#core-metadata


File: python.info,  Node: Distribution Discovery,  Next: Implementing Custom Providers,  Prev: Distributions,  Up: importlib metadata – Accessing package metadata

5.31.8.10 Distribution Discovery
................................

By default, this package provides built-in support for discovery of
metadata for file system and zip file Distribution Package(1)s.  This
metadata finder search defaults to ‘sys.path’, but varies slightly in
how it interprets those values from how other import machinery does.  In
particular:

   - ‘importlib.metadata’ does not honor *note bytes: 192. objects on
     ‘sys.path’.

   - ‘importlib.metadata’ will incidentally honor *note pathlib.Path:
     266. objects on ‘sys.path’ even though such values will be ignored
     for imports.

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/glossary/#term-Distribution-Package


File: python.info,  Node: Implementing Custom Providers,  Prev: Distribution Discovery,  Up: importlib metadata – Accessing package metadata

5.31.8.11 Implementing Custom Providers
.......................................

‘importlib.metadata’ address two API surfaces, one for 'consumers' and
another for 'providers'.  Most users are consumers, consuming metadata
provided by the packages.  There are other use-cases, however, where
users wish to expose metadata through some other mechanism, such as
alongside a custom importer.  Such a use case calls for a 'custom
provider'.

Because Distribution Package(1) metadata is not available through *note
sys.path: 3e4. searches, or package loaders directly, the metadata for a
distribution is found through import system *note finders: 242a.  To
find a distribution package’s metadata, ‘importlib.metadata’ queries the
list of *note meta path finders: 1272. on *note sys.meta_path: f29.

The implementation has hooks integrated into the ‘PathFinder’, serving
metadata for distribution packages found on the file system.

The abstract class *note importlib.abc.MetaPathFinder: a70. defines the
interface expected of finders by Python’s import system.
‘importlib.metadata’ extends this protocol by looking for an optional
‘find_distributions’ callable on the finders from *note sys.meta_path:
f29. and presents this extended interface as the ‘DistributionFinder’
abstract base class, which defines this abstract method:

     @abc.abstractmethod
     def find_distributions(context=DistributionFinder.Context()) -> Iterable[Distribution]:
         """Return an iterable of all Distribution instances capable of
         loading the metadata for packages for the indicated ``context``.
         """

The ‘DistributionFinder.Context’ object provides ‘.path’ and ‘.name’
properties indicating the path to search and name to match and may
supply other relevant context sought by the consumer.

In practice, to support finding distribution package metadata in
locations other than the file system, subclass ‘Distribution’ and
implement the abstract methods.  Then from a custom finder, return
instances of this derived ‘Distribution’ in the ‘find_distributions()’
method.

* Menu:

* Example: Example<14>.

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/glossary/#term-Distribution-Package


File: python.info,  Node: Example<14>,  Up: Implementing Custom Providers

5.31.8.12 Example
.................

Imagine a custom finder that loads Python modules from a database:

     class DatabaseImporter(importlib.abc.MetaPathFinder):
         def __init__(self, db):
             self.db = db

         def find_spec(self, fullname, target=None) -> ModuleSpec:
             return self.db.spec_from_name(fullname)

     sys.meta_path.append(DatabaseImporter(connect_db(...)))

That importer now presumably provides importable modules from a
database, but it provides no metadata or entry points.  For this custom
importer to provide metadata, it would also need to implement
‘DistributionFinder’:

     from importlib.metadata import DistributionFinder

     class DatabaseImporter(DistributionFinder):
         ...

         def find_distributions(self, context=DistributionFinder.Context()):
             query = dict(name=context.name) if context.name else {}
             for dist_record in self.db.query_distributions(query):
                 yield DatabaseDistribution(dist_record)

In this way, ‘query_distributions’ would return records for each
distribution served by the database matching the query.  For example, if
‘requests-1.0’ is in the database, ‘find_distributions’ would yield a
‘DatabaseDistribution’ for ‘Context(name='requests')’ or
‘Context(name=None)’.

For the sake of simplicity, this example ignores ‘context.path’.  The
‘path’ attribute defaults to ‘sys.path’ and is the set of import paths
to be considered in the search.  A ‘DatabaseImporter’ could potentially
function without any concern for a search path.  Assuming the importer
does no partitioning, the «path» would be irrelevant.  In order to
illustrate the purpose of ‘path’, the example would need to illustrate a
more complex ‘DatabaseImporter’ whose behavior varied depending on
‘sys.path’/‘PYTHONPATH’.  In that case, the ‘find_distributions’ should
honor the ‘context.path’ and only yield ‘Distribution’s pertinent to
that path.

‘DatabaseDistribution’, then, would look something like:

     class DatabaseDistribution(importlib.metadata.Distribution):
         def __init__(self, record):
             self.record = record

         def read_text(self, filename):
             """
             Read a file like "METADATA" for the current distribution.
             """
             if filename == "METADATA":
                 return f"""Name: {self.record.name}
     Version: {self.record.version}
     """
             if filename == "entry_points.txt":
                 return "\n".join(
                   f"""[{ep.group}]\n{ep.name}={ep.value}"""
                   for ep in self.record.entry_points)

         def locate_file(self, path):
             raise RuntimeError("This distribution has no file system")

This basic implementation should provide metadata and entry points for
packages served by the ‘DatabaseImporter’, assuming that the ‘record’
supplies suitable ‘.name’, ‘.version’, and ‘.entry_points’ attributes.

The ‘DatabaseDistribution’ may also provide other metadata files, like
‘RECORD’ (required for ‘Distribution.files’) or override the
implementation of ‘Distribution.files’.  See the source for more
inspiration.


File: python.info,  Node: The initialization of the sys path module search path,  Prev: importlib metadata – Accessing package metadata,  Up: Importing Modules

5.31.9 The initialization of the ‘sys.path’ module search path
--------------------------------------------------------------

A module search path is initialized when Python starts.  This module
search path may be accessed at *note sys.path: 3e4.

The first entry in the module search path is the directory that contains
the input script, if there is one.  Otherwise, the first entry is the
current directory, which is the case when executing the interactive
shell, a *note -c: 1a8. command, or *note -m: 23c. module.

The *note PYTHONPATH: 121f. environment variable is often used to add
directories to the search path.  If this environment variable is found
then the contents are added to the module search path.

     Nota: *note PYTHONPATH: 121f. will affect all installed Python
     versions/environments.  Be wary of setting this in your shell
     profile or global environment variables.  The *note site: cc.
     module offers more nuanced techniques as mentioned below.

The next items added are the directories containing standard Python
modules as well as any *note extension module: 223a.s that these modules
depend on.  Extension modules are ‘.pyd’ files on Windows and ‘.so’
files on other platforms.  The directory with the platform-independent
Python modules is called ‘prefix’.  The directory with the extension
modules is called ‘exec_prefix’.

The *note PYTHONHOME: 3f0. environment variable may be used to set the
‘prefix’ and ‘exec_prefix’ locations.  Otherwise these directories are
found by using the Python executable as a starting point and then
looking for various “landmark” files and directories.  Note that any
symbolic links are followed so the real Python executable location is
used as the search starting point.  The Python executable location is
called ‘home’.

Once ‘home’ is determined, the ‘prefix’ directory is found by first
looking for ‘python`majorversion'`minorversion'.zip’ (‘python311.zip’).
On Windows the zip archive is searched for in ‘home’ and on Unix the
archive is expected to be in ‘lib’.  Note that the expected zip archive
location is added to the module search path even if the archive does not
exist.  If no archive was found, Python on Windows will continue the
search for ‘prefix’ by looking for ‘Lib\os.py’.  Python on Unix will
look for ‘lib/python`majorversion'.`minorversion'/os.py’
(‘lib/python3.11/os.py’).  On Windows ‘prefix’ and ‘exec_prefix’ are the
same, however on other platforms
‘lib/python`majorversion'.`minorversion'/lib-dynload’
(‘lib/python3.11/lib-dynload’) is searched for and used as an anchor for
‘exec_prefix’.  On some platforms ‘lib’ may be ‘lib64’ or another value,
see *note sys.platlibdir: b34. and *note PYTHONPLATLIBDIR: 1d0b.

Once found, ‘prefix’ and ‘exec_prefix’ are available at *note
sys.base_prefix: 3e6. and *note sys.base_exec_prefix: 3ea. respectively.

If *note PYTHONHOME: 3f0. is not set, and a ‘pyvenv.cfg’ file is found
alongside the main executable, or in its parent directory, *note
sys.prefix: 3e7. and *note sys.exec_prefix: 3eb. get set to the
directory containing ‘pyvenv.cfg’, otherwise they are set to the same
value as *note sys.base_prefix: 3e6. and *note sys.base_exec_prefix:
3ea, respectively.  This is used by *note Virtual Environments: 489b.

Finally, the *note site: cc. module is processed and ‘site-packages’
directories are added to the module search path.  A common way to
customize the search path is to create *note sitecustomize: cd. or *note
usercustomize: 114. modules as described in the *note site: cc. module
documentation.

     Nota: Certain command line options may further affect path
     calculations.  See *note -E: b58, *note -I: b59, *note -s: 1596.
     and *note -S: 13b0. for further details.

Cambiato nella versione 3.14: *note sys.prefix: 3e7. and *note
sys.exec_prefix: 3eb. are now set to the ‘pyvenv.cfg’ directory during
the path initialization.  This was previously done by *note site: cc,
therefore affected by *note -S: 13b0.

* Menu:

* Virtual Environments::
* _pth files::
* Embedded Python::


File: python.info,  Node: Virtual Environments,  Next: _pth files,  Up: The initialization of the sys path module search path

5.31.9.1 Virtual Environments
.............................

Virtual environments place a ‘pyvenv.cfg’ file in their prefix, which
causes *note sys.prefix: 3e7. and *note sys.exec_prefix: 3eb. to point
to them, instead of the base installation.

The ‘prefix’ and ‘exec_prefix’ values of the base installation are
available at *note sys.base_prefix: 3e6. and *note sys.base_exec_prefix:
3ea.

As well as being used as a marker to identify virtual environments,
‘pyvenv.cfg’ may also be used to configure the *note site: cc.
initialization.  Please refer to *note site: cc.’s *note virtual
environments documentation: 489c.

     Nota: *note PYTHONHOME: 3f0. overrides the ‘pyvenv.cfg’ detection.

     Nota: There are other ways how «virtual environments» could be
     implemented, this documentation refers implementations based on the
     ‘pyvenv.cfg’ mechanism, such as *note venv: 117.  Most virtual
     environment implementations follow the model set by *note venv:
     117, but there may be exotic implementations that diverge from it.


File: python.info,  Node: _pth files,  Next: Embedded Python,  Prev: Virtual Environments,  Up: The initialization of the sys path module search path

5.31.9.2 _pth files
...................

To completely override *note sys.path: 3e4. create a ‘._pth’ file with
the same name as the shared library or executable (‘python._pth’ or
‘python311._pth’).  The shared library path is always known on Windows,
however it may not be available on other platforms.  In the ‘._pth’ file
specify one line for each path to add to *note sys.path: 3e4.  The file
based on the shared library name overrides the one based on the
executable, which allows paths to be restricted for any program loading
the runtime if desired.

When the file exists, all registry and environment variables are
ignored, isolated mode is enabled, and *note site: cc. is not imported
unless one line in the file specifies ‘import site’.  Blank paths and
lines starting with ‘#’ are ignored.  Each path may be absolute or
relative to the location of the file.  Import statements other than to
‘site’ are not permitted, and arbitrary code cannot be specified.

Note that ‘.pth’ files (without leading underscore) will be processed
normally by the *note site: cc. module when ‘import site’ has been
specified.


File: python.info,  Node: Embedded Python,  Prev: _pth files,  Up: The initialization of the sys path module search path

5.31.9.3 Embedded Python
........................

If Python is embedded within another application *note
Py_InitializeFromConfig(): 3f6. and the *note PyConfig: 3f7. structure
can be used to initialize Python.  The path specific details are
described at *note Python Path Configuration: aac.

Vedi anche
..........

   * *note Finding modules: e1c. for detailed Windows notes.

   * *note Using Python on Unix platforms: 212d. for Unix details.


File: python.info,  Node: Python Language Services,  Next: MS Windows Specific Services,  Prev: Importing Modules,  Up: The Python Standard Library

5.32 Python Language Services
=============================

Python provides a number of modules to assist in working with the Python
language.  These modules support tokenizing, parsing, syntax analysis,
bytecode disassembly, and various other facilities.

These modules include:

* Menu:

* ast — Abstract syntax trees::
* symtable — Access to the compiler’s symbol tables::
* token — Constants used with Python parse trees::
* keyword — Testing for Python keywords::
* tokenize — Tokenizer for Python source::
* tabnanny — Detection of ambiguous indentation::
* pyclbr — Python module browser support::
* py_compile — Compile Python source files::
* compileall — Byte-compile Python libraries::
* dis — Disassembler for Python bytecode::
* pickletools — Tools for pickle developers::


File: python.info,  Node: ast — Abstract syntax trees,  Next: symtable — Access to the compiler’s symbol tables,  Up: Python Language Services

5.32.1 ‘ast’ — Abstract syntax trees
------------------------------------

'Source code:' Lib/ast.py(1)

__________________________________________________________________

The *note ast: 9. module helps Python applications to process trees of
the Python abstract syntax grammar.  The abstract syntax itself might
change with each Python release; this module helps to find out
programmatically what the current grammar looks like.

An abstract syntax tree can be generated by passing *note
ast.PyCF_ONLY_AST: 4b59. as a flag to the *note compile(): 4b2. built-in
function, or using the *note parse(): 1c2. helper provided in this
module.  The result will be a tree of objects whose classes all inherit
from *note ast.AST: 4c4.  An abstract syntax tree can be compiled into a
Python code object using the built-in *note compile(): 4b2. function.

* Menu:

* Abstract grammar::
* Node classes::
* ast helpers::
* Compiler flags: Compiler flags<2>.
* Command-line usage: Command-line usage<7>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/ast.py


File: python.info,  Node: Abstract grammar,  Next: Node classes,  Up: ast — Abstract syntax trees

5.32.1.1 Abstract grammar
.........................

The abstract grammar is currently defined as follows:

     -- ASDL's 4 builtin types are:
     -- identifier, int, string, constant

     module Python
     {
         mod = Module(stmt* body, type_ignore* type_ignores)
             | Interactive(stmt* body)
             | Expression(expr body)
             | FunctionType(expr* argtypes, expr returns)

         stmt = FunctionDef(identifier name, arguments args,
                            stmt* body, expr* decorator_list, expr? returns,
                            string? type_comment, type_param* type_params)
               | AsyncFunctionDef(identifier name, arguments args,
                                  stmt* body, expr* decorator_list, expr? returns,
                                  string? type_comment, type_param* type_params)

               | ClassDef(identifier name,
                  expr* bases,
                  keyword* keywords,
                  stmt* body,
                  expr* decorator_list,
                  type_param* type_params)
               | Return(expr? value)

               | Delete(expr* targets)
               | Assign(expr* targets, expr value, string? type_comment)
               | TypeAlias(expr name, type_param* type_params, expr value)
               | AugAssign(expr target, operator op, expr value)
               -- 'simple' indicates that we annotate simple name without parens
               | AnnAssign(expr target, expr annotation, expr? value, int simple)

               -- use 'orelse' because else is a keyword in target languages
               | For(expr target, expr iter, stmt* body, stmt* orelse, string? type_comment)
               | AsyncFor(expr target, expr iter, stmt* body, stmt* orelse, string? type_comment)
               | While(expr test, stmt* body, stmt* orelse)
               | If(expr test, stmt* body, stmt* orelse)
               | With(withitem* items, stmt* body, string? type_comment)
               | AsyncWith(withitem* items, stmt* body, string? type_comment)

               | Match(expr subject, match_case* cases)

               | Raise(expr? exc, expr? cause)
               | Try(stmt* body, excepthandler* handlers, stmt* orelse, stmt* finalbody)
               | TryStar(stmt* body, excepthandler* handlers, stmt* orelse, stmt* finalbody)
               | Assert(expr test, expr? msg)

               | Import(alias* names)
               | ImportFrom(identifier? module, alias* names, int? level)

               | Global(identifier* names)
               | Nonlocal(identifier* names)
               | Expr(expr value)
               | Pass | Break | Continue

               -- col_offset is the byte offset in the utf8 string the parser uses
               attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset)

               -- BoolOp() can use left & right?
         expr = BoolOp(boolop op, expr* values)
              | NamedExpr(expr target, expr value)
              | BinOp(expr left, operator op, expr right)
              | UnaryOp(unaryop op, expr operand)
              | Lambda(arguments args, expr body)
              | IfExp(expr test, expr body, expr orelse)
              | Dict(expr?* keys, expr* values)
              | Set(expr* elts)
              | ListComp(expr elt, comprehension* generators)
              | SetComp(expr elt, comprehension* generators)
              | DictComp(expr key, expr value, comprehension* generators)
              | GeneratorExp(expr elt, comprehension* generators)
              -- the grammar constrains where yield expressions can occur
              | Await(expr value)
              | Yield(expr? value)
              | YieldFrom(expr value)
              -- need sequences for compare to distinguish between
              -- x < 4 < 3 and (x < 4) < 3
              | Compare(expr left, cmpop* ops, expr* comparators)
              | Call(expr func, expr* args, keyword* keywords)
              | FormattedValue(expr value, int conversion, expr? format_spec)
              | Interpolation(expr value, constant str, int conversion, expr? format_spec)
              | JoinedStr(expr* values)
              | TemplateStr(expr* values)
              | Constant(constant value, string? kind)

              -- the following expression can appear in assignment context
              | Attribute(expr value, identifier attr, expr_context ctx)
              | Subscript(expr value, expr slice, expr_context ctx)
              | Starred(expr value, expr_context ctx)
              | Name(identifier id, expr_context ctx)
              | List(expr* elts, expr_context ctx)
              | Tuple(expr* elts, expr_context ctx)

              -- can appear only in Subscript
              | Slice(expr? lower, expr? upper, expr? step)

               -- col_offset is the byte offset in the utf8 string the parser uses
               attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset)

         expr_context = Load | Store | Del

         boolop = And | Or

         operator = Add | Sub | Mult | MatMult | Div | Mod | Pow | LShift
                      | RShift | BitOr | BitXor | BitAnd | FloorDiv

         unaryop = Invert | Not | UAdd | USub

         cmpop = Eq | NotEq | Lt | LtE | Gt | GtE | Is | IsNot | In | NotIn

         comprehension = (expr target, expr iter, expr* ifs, int is_async)

         excepthandler = ExceptHandler(expr? type, identifier? name, stmt* body)
                         attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset)

         arguments = (arg* posonlyargs, arg* args, arg? vararg, arg* kwonlyargs,
                      expr?* kw_defaults, arg? kwarg, expr* defaults)

         arg = (identifier arg, expr? annotation, string? type_comment)
                attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset)

         -- keyword arguments supplied to call (NULL identifier for **kwargs)
         keyword = (identifier? arg, expr value)
                    attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset)

         -- import name with optional 'as' alias.
         alias = (identifier name, identifier? asname)
                  attributes (int lineno, int col_offset, int? end_lineno, int? end_col_offset)

         withitem = (expr context_expr, expr? optional_vars)

         match_case = (pattern pattern, expr? guard, stmt* body)

         pattern = MatchValue(expr value)
                 | MatchSingleton(constant value)
                 | MatchSequence(pattern* patterns)
                 | MatchMapping(expr* keys, pattern* patterns, identifier? rest)
                 | MatchClass(expr cls, pattern* patterns, identifier* kwd_attrs, pattern* kwd_patterns)

                 | MatchStar(identifier? name)
                 -- The optional "rest" MatchMapping parameter handles capturing extra mapping keys

                 | MatchAs(pattern? pattern, identifier? name)
                 | MatchOr(pattern* patterns)

                  attributes (int lineno, int col_offset, int end_lineno, int end_col_offset)

         type_ignore = TypeIgnore(int lineno, string tag)

         type_param = TypeVar(identifier name, expr? bound, expr? default_value)
                    | ParamSpec(identifier name, expr? default_value)
                    | TypeVarTuple(identifier name, expr? default_value)
                    attributes (int lineno, int col_offset, int end_lineno, int end_col_offset)
     }


File: python.info,  Node: Node classes,  Next: ast helpers,  Prev: Abstract grammar,  Up: ast — Abstract syntax trees

5.32.1.2 Node classes
.....................

 -- Classe: ast.AST

     This is the base of all AST node classes.  The actual node classes
     are derived from the ‘Parser/Python.asdl’ file, which is reproduced
     *note above: 4b5a.  They are defined in the ‘_ast’ C module and
     re-exported in *note ast: 9.

     There is one class defined for each left-hand side symbol in the
     abstract grammar (for example, ‘ast.stmt’ or ‘ast.expr’).  In
     addition, there is one class defined for each constructor on the
     right-hand side; these classes inherit from the classes for the
     left-hand side trees.  For example, *note ast.BinOp: 1d9a. inherits
     from ‘ast.expr’.  For production rules with alternatives (aka
     «sums»), the left-hand side class is abstract: only instances of
     specific constructor nodes are ever created.

      -- Attributo: _fields

          Each concrete class has an attribute ‘_fields’ which gives the
          names of all child nodes.

          Each instance of a concrete class has one attribute for each
          child node, of the type as defined in the grammar.  For
          example, *note ast.BinOp: 1d9a. instances have an attribute
          ‘left’ of type ‘ast.expr’.

          If these attributes are marked as optional in the grammar
          (using a question mark), the value might be ‘None’.  If the
          attributes can have zero-or-more values (marked with an
          asterisk), the values are represented as Python lists.  All
          possible attributes must be present and have valid values when
          compiling an AST with *note compile(): 4b2.

      -- Attributo: _field_types

          The ‘_field_types’ attribute on each concrete class is a
          dictionary mapping field names (as also listed in *note
          _fields: 17bf.) to their types.

               >>> ast.TypeVar._field_types
               {'name': <class 'str'>, 'bound': ast.expr | None, 'default_value': ast.expr | None}

          Added in version 3.13.

      -- Attributo: lineno
      -- Attributo: col_offset
      -- Attributo: end_lineno
      -- Attributo: end_col_offset

          Instances of ‘ast.expr’ and ‘ast.stmt’ subclasses have *note
          lineno: 4b5d, *note col_offset: 4b5e, *note end_lineno: 4b5f,
          and *note end_col_offset: 4b60. attributes.  The *note lineno:
          4b5d. and *note end_lineno: 4b5f. are the first and last line
          numbers of source text span (1-indexed so the first line is
          line 1) and the *note col_offset: 4b5e. and *note
          end_col_offset: 4b60. are the corresponding UTF-8 byte offsets
          of the first and last tokens that generated the node.  The
          UTF-8 offset is recorded because the parser uses UTF-8
          internally.

          Note that the end positions are not required by the compiler
          and are therefore optional.  The end offset is 'after' the
          last symbol, for example one can get the source segment of a
          one-line expression node using ‘source_line[node.col_offset :
          node.end_col_offset]’.

     The constructor of a class ‘ast.T’ parses its arguments as follows:

        * If there are positional arguments, there must be as many as
          there are items in ‘T._fields’; they will be assigned as
          attributes of these names.

        * If there are keyword arguments, they will set the attributes
          of the same names to the given values.

     For example, to create and populate an *note ast.UnaryOp: 4a67.
     node, you could use

          node = ast.UnaryOp(ast.USub(), ast.Constant(5, lineno=0, col_offset=0),
                             lineno=0, col_offset=0)

     If a field that is optional in the grammar is omitted from the
     constructor, it defaults to ‘None’.  If a list field is omitted, it
     defaults to the empty list.  If a field of type ‘ast.expr_context’
     is omitted, it defaults to *note Load(): 4c3.  If any other field
     is omitted, a *note DeprecationWarning: 1a3. is raised and the AST
     node will not have this field.  In Python 3.15, this condition will
     raise an error.

Cambiato nella versione 3.8: Class *note ast.Constant: 2ef. is now used
for all constants.

Cambiato nella versione 3.9: Simple indices are represented by their
value, extended slices are represented as tuples.

Cambiato nella versione 3.14: The *note __repr__(): 830. output of *note
AST: 4c4. nodes includes the values of the node fields.

Deprecated since version 3.8, removed in version 3.14: Previous versions
of Python provided the AST classes ‘ast.Num’, ‘ast.Str’, ‘ast.Bytes’,
‘ast.NameConstant’ and ‘ast.Ellipsis’, which were deprecated in Python
3.8.  These classes were removed in Python 3.14, and their functionality
has been replaced with *note ast.Constant: 2ef.

Deprecato dalla versione 3.9: Old classes ‘ast.Index’ and ‘ast.ExtSlice’
are still available, but they will be removed in future Python releases.
In the meantime, instantiating them will return an instance of a
different class.

Deprecated since version 3.13, will be removed in version 3.15: Previous
versions of Python allowed the creation of AST nodes that were missing
required fields.  Similarly, AST node constructors allowed arbitrary
keyword arguments that were set as attributes of the AST node, even if
they did not match any of the fields of the AST node.  This behavior is
deprecated and will be removed in Python 3.15.

     Nota: The descriptions of the specific node classes displayed here
     were initially adapted from the fantastic Green Tree Snakes(1)
     project and all its contributors.

* Menu:

* Root nodes::
* Literals: Literals<3>.
* Variables::
* Expressions: Expressions<2>.
* Statements::
* Control flow::
* Pattern matching::
* Type annotations::
* Type parameters::
* Function and class definitions::
* Async and await::

   ---------- Footnotes ----------

   (1) https://greentreesnakes.readthedocs.io/en/latest/


File: python.info,  Node: Root nodes,  Next: Literals<3>,  Up: Node classes

5.32.1.3 Root nodes
...................

 -- Classe: ast.Module (body, type_ignores)

     A Python module, as with *note file input: 257a.  Node type
     generated by *note ast.parse(): 1c2. in the default ‘"exec"’
     'mode'.

     ‘body’ is a *note list: 24d. of the module’s *note Statements:
     4b64.

     ‘type_ignores’ is a *note list: 24d. of the module’s type ignore
     comments; see *note ast.parse(): 1c2. for more details.

          >>> print(ast.dump(ast.parse('x = 1'), indent=4))
          Module(
              body=[
                  Assign(
                      targets=[
                          Name(id='x', ctx=Store())],
                      value=Constant(value=1))])

 -- Classe: ast.Expression (body)

     A single Python *note expression input: 2580.  Node type generated
     by *note ast.parse(): 1c2. when 'mode' is ‘"eval"’.

     ‘body’ is a single node, one of the *note expression types: 4b66.

          >>> print(ast.dump(ast.parse('123', mode='eval'), indent=4))
          Expression(
              body=Constant(value=123))

 -- Classe: ast.Interactive (body)

     A single *note interactive input: 257d, like in *note Modalità
     Interattiva: 495.  Node type generated by *note ast.parse(): 1c2.
     when 'mode' is ‘"single"’.

     ‘body’ is a *note list: 24d. of *note statement nodes: 4b64.

          >>> print(ast.dump(ast.parse('x = 1; y = 2', mode='single'), indent=4))
          Interactive(
              body=[
                  Assign(
                      targets=[
                          Name(id='x', ctx=Store())],
                      value=Constant(value=1)),
                  Assign(
                      targets=[
                          Name(id='y', ctx=Store())],
                      value=Constant(value=2))])

 -- Classe: ast.FunctionType (argtypes, returns)

     A representation of an old-style type comments for functions, as
     Python versions prior to 3.5 didn’t support PEP 484(1) annotations.
     Node type generated by *note ast.parse(): 1c2. when 'mode' is
     ‘"func_type"’.

     Such type comments would look like this:

          def sum_two_number(a, b):
              # type: (int, int) -> int
              return a + b

     ‘argtypes’ is a *note list: 24d. of *note expression nodes: 4b66.

     ‘returns’ is a single *note expression node: 4b66.

          >>> print(ast.dump(ast.parse('(int, str) -> List[int]', mode='func_type'), indent=4))
          FunctionType(
              argtypes=[
                  Name(id='int', ctx=Load()),
                  Name(id='str', ctx=Load())],
              returns=Subscript(
                  value=Name(id='List', ctx=Load()),
                  slice=Name(id='int', ctx=Load()),
                  ctx=Load()))

     Added in version 3.8.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/


File: python.info,  Node: Literals<3>,  Next: Variables,  Prev: Root nodes,  Up: Node classes

5.32.1.4 Literals
.................

 -- Classe: ast.Constant (value)

     A constant value.  The ‘value’ attribute of the ‘Constant’ literal
     contains the Python object it represents.  The values represented
     can be instances of *note str: 169, *note bytes: 192, *note int:
     19b, *note float: 196, *note complex: 197, and *note bool: 3c3, and
     the constants *note None: 886. and *note Ellipsis: 2311.

          >>> print(ast.dump(ast.parse('123', mode='eval'), indent=4))
          Expression(
              body=Constant(value=123))

 -- Classe: ast.FormattedValue (value, conversion, format_spec)

     Node representing a single formatting field in an f-string.  If the
     string contains a single formatting field and nothing else the node
     can be isolated otherwise it appears in *note JoinedStr: 1a44.

        * ‘value’ is any expression node (such as a literal, a variable,
          or a function call).

        * ‘conversion’ is an integer:

             * -1: no formatting

             * 97 (‘ord('a')’): ‘!a’ *note ASCII: 15ed. formatting

             * 114 (‘ord('r')’): ‘!r’ *note repr(): 1c1. formatting

             * 115 (‘ord('s')’): ‘!s’ *note string: 169. formatting

        * ‘format_spec’ is a *note JoinedStr: 1a44. node representing
          the formatting of the value, or ‘None’ if no format was
          specified.  Both ‘conversion’ and ‘format_spec’ can be set at
          the same time.

 -- Classe: ast.JoinedStr (values)

     An f-string, comprising a series of *note FormattedValue: 4a7f. and
     *note Constant: 2ef. nodes.

          >>> print(ast.dump(ast.parse('f"sin({a}) is {sin(a):.3}"', mode='eval'), indent=4))
          Expression(
              body=JoinedStr(
                  values=[
                      Constant(value='sin('),
                      FormattedValue(
                          value=Name(id='a', ctx=Load()),
                          conversion=-1),
                      Constant(value=') is '),
                      FormattedValue(
                          value=Call(
                              func=Name(id='sin', ctx=Load()),
                              args=[
                                  Name(id='a', ctx=Load())]),
                          conversion=-1,
                          format_spec=JoinedStr(
                              values=[
                                  Constant(value='.3')]))]))

 -- Classe: ast.TemplateStr (values, /)

     Added in version 3.14.

     Node representing a template string literal, comprising a series of
     *note Interpolation: 179d. and *note Constant: 2ef. nodes.  These
     nodes may be any order, and do not need to be interleaved.

          >>> expr = ast.parse('t"{name} finished {place:ordinal}"', mode='eval')
          >>> print(ast.dump(expr, indent=4))
          Expression(
              body=TemplateStr(
                  values=[
                      Interpolation(
                          value=Name(id='name', ctx=Load()),
                          str='name',
                          conversion=-1),
                      Constant(value=' finished '),
                      Interpolation(
                          value=Name(id='place', ctx=Load()),
                          str='place',
                          conversion=-1,
                          format_spec=JoinedStr(
                              values=[
                                  Constant(value='ordinal')]))]))

 -- Classe: ast.Interpolation (value, str, conversion, format_spec=None)

     Added in version 3.14.

     Node representing a single interpolation field in a template string
     literal.

        * ‘value’ is any expression node (such as a literal, a variable,
          or a function call).  This has the same meaning as
          ‘FormattedValue.value’.

        * ‘str’ is a constant containing the text of the interpolation
          expression.

          If ‘str’ is set to ‘None’, then ‘value’ is used to generate
          code when calling *note ast.unparse(): ae4.  This no longer
          guarantees that the generated code is identical to the
          original and is intended for code generation.

        * ‘conversion’ is an integer:

             * -1: no conversion

             * 97 (‘ord('a')’): ‘!a’ *note ASCII: 15ed. conversion

             * 114 (‘ord('r')’): ‘!r’ *note repr(): 1c1. conversion

             * 115 (‘ord('s')’): ‘!s’ *note string: 169. conversion

          This has the same meaning as ‘FormattedValue.conversion’.

        * ‘format_spec’ is a *note JoinedStr: 1a44. node representing
          the formatting of the value, or ‘None’ if no format was
          specified.  Both ‘conversion’ and ‘format_spec’ can be set at
          the same time.  This has the same meaning as
          ‘FormattedValue.format_spec’.

 -- Classe: ast.List (elts, ctx)
 -- Classe: ast.Tuple (elts, ctx)

     A list or tuple.  ‘elts’ holds a list of nodes representing the
     elements.  ‘ctx’ is *note Store: 4b6a. if the container is an
     assignment target (i.e.  ‘(x,y)=something’), and *note Load: 4c3.
     otherwise.

          >>> print(ast.dump(ast.parse('[1, 2, 3]', mode='eval'), indent=4))
          Expression(
              body=List(
                  elts=[
                      Constant(value=1),
                      Constant(value=2),
                      Constant(value=3)],
                  ctx=Load()))
          >>> print(ast.dump(ast.parse('(1, 2, 3)', mode='eval'), indent=4))
          Expression(
              body=Tuple(
                  elts=[
                      Constant(value=1),
                      Constant(value=2),
                      Constant(value=3)],
                  ctx=Load()))

 -- Classe: ast.Set (elts)

     A set.  ‘elts’ holds a list of nodes representing the set’s
     elements.

          >>> print(ast.dump(ast.parse('{1, 2, 3}', mode='eval'), indent=4))
          Expression(
              body=Set(
                  elts=[
                      Constant(value=1),
                      Constant(value=2),
                      Constant(value=3)]))

 -- Classe: ast.Dict (keys, values)

     A dictionary.  ‘keys’ and ‘values’ hold lists of nodes representing
     the keys and the values respectively, in matching order (what would
     be returned when calling ‘dictionary.keys()’ and
     ‘dictionary.values()’).

     When doing dictionary unpacking using dictionary literals the
     expression to be expanded goes in the ‘values’ list, with a ‘None’
     at the corresponding position in ‘keys’.

          >>> print(ast.dump(ast.parse('{"a":1, **d}', mode='eval'), indent=4))
          Expression(
              body=Dict(
                  keys=[
                      Constant(value='a'),
                      None],
                  values=[
                      Constant(value=1),
                      Name(id='d', ctx=Load())]))


File: python.info,  Node: Variables,  Next: Expressions<2>,  Prev: Literals<3>,  Up: Node classes

5.32.1.5 Variables
..................

 -- Classe: ast.Name (id, ctx)

     A variable name.  ‘id’ holds the name as a string, and ‘ctx’ is one
     of the following types.

 -- Classe: ast.Load
 -- Classe: ast.Store
 -- Classe: ast.Del

     Variable references can be used to load the value of a variable, to
     assign a new value to it, or to delete it.  Variable references are
     given a context to distinguish these cases.

          >>> print(ast.dump(ast.parse('a'), indent=4))
          Module(
              body=[
                  Expr(
                      value=Name(id='a', ctx=Load()))])

          >>> print(ast.dump(ast.parse('a = 1'), indent=4))
          Module(
              body=[
                  Assign(
                      targets=[
                          Name(id='a', ctx=Store())],
                      value=Constant(value=1))])

          >>> print(ast.dump(ast.parse('del a'), indent=4))
          Module(
              body=[
                  Delete(
                      targets=[
                          Name(id='a', ctx=Del())])])

 -- Classe: ast.Starred (value, ctx)

     A ‘*var’ variable reference.  ‘value’ holds the variable, typically
     a *note Name: 1d0a. node.  This type must be used when building a
     *note Call: 4a78. node with ‘*args’.

          >>> print(ast.dump(ast.parse('a, *b = it'), indent=4))
          Module(
              body=[
                  Assign(
                      targets=[
                          Tuple(
                              elts=[
                                  Name(id='a', ctx=Store()),
                                  Starred(
                                      value=Name(id='b', ctx=Store()),
                                      ctx=Store())],
                              ctx=Store())],
                      value=Name(id='it', ctx=Load()))])


File: python.info,  Node: Expressions<2>,  Next: Statements,  Prev: Variables,  Up: Node classes

5.32.1.6 Expressions
....................

 -- Classe: ast.Expr (value)

     When an expression, such as a function call, appears as a statement
     by itself with its return value not used or stored, it is wrapped
     in this container.  ‘value’ holds one of the other nodes in this
     section, a *note Constant: 2ef, a *note Name: 1d0a, a *note Lambda:
     4a82, a *note Yield: 4a89. or *note YieldFrom: 4a8a. node.

          >>> print(ast.dump(ast.parse('-a'), indent=4))
          Module(
              body=[
                  Expr(
                      value=UnaryOp(
                          op=USub(),
                          operand=Name(id='a', ctx=Load())))])

 -- Classe: ast.UnaryOp (op, operand)

     A unary operation.  ‘op’ is the operator, and ‘operand’ any
     expression node.

 -- Classe: ast.UAdd
 -- Classe: ast.USub
 -- Classe: ast.Not
 -- Classe: ast.Invert

     Unary operator tokens.  *note Not: 4a6b. is the ‘not’ keyword,
     *note Invert: 4a68. is the ‘~’ operator.

          >>> print(ast.dump(ast.parse('not x', mode='eval'), indent=4))
          Expression(
              body=UnaryOp(
                  op=Not(),
                  operand=Name(id='x', ctx=Load())))

 -- Classe: ast.BinOp (left, op, right)

     A binary operation (like addition or division).  ‘op’ is the
     operator, and ‘left’ and ‘right’ are any expression nodes.

          >>> print(ast.dump(ast.parse('x + y', mode='eval'), indent=4))
          Expression(
              body=BinOp(
                  left=Name(id='x', ctx=Load()),
                  op=Add(),
                  right=Name(id='y', ctx=Load())))

 -- Classe: ast.Add
 -- Classe: ast.Sub
 -- Classe: ast.Mult
 -- Classe: ast.Div
 -- Classe: ast.FloorDiv
 -- Classe: ast.Mod
 -- Classe: ast.Pow
 -- Classe: ast.LShift
 -- Classe: ast.RShift
 -- Classe: ast.BitOr
 -- Classe: ast.BitXor
 -- Classe: ast.BitAnd
 -- Classe: ast.MatMult

     Binary operator tokens.

 -- Classe: ast.BoolOp (op, values)

     A boolean operation, “or” or “and”.  ‘op’ is *note Or: 4b7c. or
     *note And: 4b7d.  ‘values’ are the values involved.  Consecutive
     operations with the same operator, such as ‘a or b or c’, are
     collapsed into one node with several values.

     This doesn’t include ‘not’, which is a *note UnaryOp: 4a67.

          >>> print(ast.dump(ast.parse('x or y', mode='eval'), indent=4))
          Expression(
              body=BoolOp(
                  op=Or(),
                  values=[
                      Name(id='x', ctx=Load()),
                      Name(id='y', ctx=Load())]))

 -- Classe: ast.And
 -- Classe: ast.Or

     Boolean operator tokens.

 -- Classe: ast.Compare (left, ops, comparators)

     A comparison of two or more values.  ‘left’ is the first value in
     the comparison, ‘ops’ the list of operators, and ‘comparators’ the
     list of values after the first element in the comparison.

          >>> print(ast.dump(ast.parse('1 <= a < 10', mode='eval'), indent=4))
          Expression(
              body=Compare(
                  left=Constant(value=1),
                  ops=[
                      LtE(),
                      Lt()],
                  comparators=[
                      Name(id='a', ctx=Load()),
                      Constant(value=10)]))

 -- Classe: ast.Eq
 -- Classe: ast.NotEq
 -- Classe: ast.Lt
 -- Classe: ast.LtE
 -- Classe: ast.Gt
 -- Classe: ast.GtE
 -- Classe: ast.Is
 -- Classe: ast.IsNot
 -- Classe: ast.In
 -- Classe: ast.NotIn

     Comparison operator tokens.

 -- Classe: ast.Call (func, args, keywords)

     A function call.  ‘func’ is the function, which will often be a
     *note Name: 1d0a. or *note Attribute: 4a79. object.  Of the
     arguments:

        * ‘args’ holds a list of the arguments passed by position.

        * ‘keywords’ holds a list of *note keyword: 4b7e. objects
          representing arguments passed by keyword.

     The ‘args’ and ‘keywords’ arguments are optional and default to
     empty lists.

          >>> print(ast.dump(ast.parse('func(a, b=c, *d, **e)', mode='eval'), indent=4))
          Expression(
              body=Call(
                  func=Name(id='func', ctx=Load()),
                  args=[
                      Name(id='a', ctx=Load()),
                      Starred(
                          value=Name(id='d', ctx=Load()),
                          ctx=Load())],
                  keywords=[
                      keyword(
                          arg='b',
                          value=Name(id='c', ctx=Load())),
                      keyword(
                          value=Name(id='e', ctx=Load()))]))

 -- Classe: ast.keyword (arg, value)

     A keyword argument to a function call or class definition.  ‘arg’
     is a raw string of the parameter name, ‘value’ is a node to pass
     in.

 -- Classe: ast.IfExp (test, body, orelse)

     An expression such as ‘a if b else c’.  Each field holds a single
     node, so in the following example, all three are *note Name: 1d0a.
     nodes.

          >>> print(ast.dump(ast.parse('a if b else c', mode='eval'), indent=4))
          Expression(
              body=IfExp(
                  test=Name(id='b', ctx=Load()),
                  body=Name(id='a', ctx=Load()),
                  orelse=Name(id='c', ctx=Load())))

 -- Classe: ast.Attribute (value, attr, ctx)

     Attribute access, e.g.  ‘d.keys’.  ‘value’ is a node, typically a
     *note Name: 1d0a.  ‘attr’ is a bare string giving the name of the
     attribute, and ‘ctx’ is *note Load: 4c3, *note Store: 4b6a. or
     *note Del: 4b6c. according to how the attribute is acted on.

          >>> print(ast.dump(ast.parse('snake.colour', mode='eval'), indent=4))
          Expression(
              body=Attribute(
                  value=Name(id='snake', ctx=Load()),
                  attr='colour',
                  ctx=Load()))

 -- Classe: ast.NamedExpr (target, value)

     A named expression.  This AST node is produced by the assignment
     expressions operator (also known as the walrus operator).  As
     opposed to the *note Assign: 4b7f. node in which the first argument
     can be multiple nodes, in this case both ‘target’ and ‘value’ must
     be single nodes.

          >>> print(ast.dump(ast.parse('(x := 4)', mode='eval'), indent=4))
          Expression(
              body=NamedExpr(
                  target=Name(id='x', ctx=Store()),
                  value=Constant(value=4)))

     Added in version 3.8.

* Menu:

* Subscripting::
* Comprehensions::


File: python.info,  Node: Subscripting,  Next: Comprehensions,  Up: Expressions<2>

5.32.1.7 Subscripting
.....................

 -- Classe: ast.Subscript (value, slice, ctx)

     A subscript, such as ‘l[1]’.  ‘value’ is the subscripted object
     (usually sequence or mapping).  ‘slice’ is an index, slice or key.
     It can be a *note Tuple: 4a7d. and contain a *note Slice: 4a7e.
     ‘ctx’ is *note Load: 4c3, *note Store: 4b6a. or *note Del: 4b6c.
     according to the action performed with the subscript.

          >>> print(ast.dump(ast.parse('l[1:2, 3]', mode='eval'), indent=4))
          Expression(
              body=Subscript(
                  value=Name(id='l', ctx=Load()),
                  slice=Tuple(
                      elts=[
                          Slice(
                              lower=Constant(value=1),
                              upper=Constant(value=2)),
                          Constant(value=3)],
                      ctx=Load()),
                  ctx=Load()))

 -- Classe: ast.Slice (lower, upper, step)

     Regular slicing (on the form ‘lower:upper’ or ‘lower:upper:step’).
     Can occur only inside the 'slice' field of *note Subscript: 4a7a,
     either directly or as an element of *note Tuple: 4a7d.

          >>> print(ast.dump(ast.parse('l[1:2]', mode='eval'), indent=4))
          Expression(
              body=Subscript(
                  value=Name(id='l', ctx=Load()),
                  slice=Slice(
                      lower=Constant(value=1),
                      upper=Constant(value=2)),
                  ctx=Load()))


File: python.info,  Node: Comprehensions,  Prev: Subscripting,  Up: Expressions<2>

5.32.1.8 Comprehensions
.......................

 -- Classe: ast.ListComp (elt, generators)
 -- Classe: ast.SetComp (elt, generators)
 -- Classe: ast.GeneratorExp (elt, generators)
 -- Classe: ast.DictComp (key, value, generators)

     List and set comprehensions, generator expressions, and dictionary
     comprehensions.  ‘elt’ (or ‘key’ and ‘value’) is a single node
     representing the part that will be evaluated for each item.

     ‘generators’ is a list of *note comprehension: 4b82. nodes.

          >>> print(ast.dump(
          ...     ast.parse('[x for x in numbers]', mode='eval'),
          ...     indent=4,
          ... ))
          Expression(
              body=ListComp(
                  elt=Name(id='x', ctx=Load()),
                  generators=[
                      comprehension(
                          target=Name(id='x', ctx=Store()),
                          iter=Name(id='numbers', ctx=Load()),
                          is_async=0)]))
          >>> print(ast.dump(
          ...     ast.parse('{x: x**2 for x in numbers}', mode='eval'),
          ...     indent=4,
          ... ))
          Expression(
              body=DictComp(
                  key=Name(id='x', ctx=Load()),
                  value=BinOp(
                      left=Name(id='x', ctx=Load()),
                      op=Pow(),
                      right=Constant(value=2)),
                  generators=[
                      comprehension(
                          target=Name(id='x', ctx=Store()),
                          iter=Name(id='numbers', ctx=Load()),
                          is_async=0)]))
          >>> print(ast.dump(
          ...     ast.parse('{x for x in numbers}', mode='eval'),
          ...     indent=4,
          ... ))
          Expression(
              body=SetComp(
                  elt=Name(id='x', ctx=Load()),
                  generators=[
                      comprehension(
                          target=Name(id='x', ctx=Store()),
                          iter=Name(id='numbers', ctx=Load()),
                          is_async=0)]))

 -- Classe: ast.comprehension (target, iter, ifs, is_async)

     One ‘for’ clause in a comprehension.  ‘target’ is the reference to
     use for each element - typically a *note Name: 1d0a. or *note
     Tuple: 4a7d. node.  ‘iter’ is the object to iterate over.  ‘ifs’ is
     a list of test expressions: each ‘for’ clause can have multiple
     ‘ifs’.

     ‘is_async’ indicates a comprehension is asynchronous (using an
     ‘async for’ instead of ‘for’).  The value is an integer (0 or 1).

          >>> print(ast.dump(ast.parse('[ord(c) for line in file for c in line]', mode='eval'),
          ...                indent=4)) # Multiple comprehensions in one.
          Expression(
              body=ListComp(
                  elt=Call(
                      func=Name(id='ord', ctx=Load()),
                      args=[
                          Name(id='c', ctx=Load())]),
                  generators=[
                      comprehension(
                          target=Name(id='line', ctx=Store()),
                          iter=Name(id='file', ctx=Load()),
                          is_async=0),
                      comprehension(
                          target=Name(id='c', ctx=Store()),
                          iter=Name(id='line', ctx=Load()),
                          is_async=0)]))

          >>> print(ast.dump(ast.parse('(n**2 for n in it if n>5 if n<10)', mode='eval'),
          ...                indent=4)) # generator comprehension
          Expression(
              body=GeneratorExp(
                  elt=BinOp(
                      left=Name(id='n', ctx=Load()),
                      op=Pow(),
                      right=Constant(value=2)),
                  generators=[
                      comprehension(
                          target=Name(id='n', ctx=Store()),
                          iter=Name(id='it', ctx=Load()),
                          ifs=[
                              Compare(
                                  left=Name(id='n', ctx=Load()),
                                  ops=[
                                      Gt()],
                                  comparators=[
                                      Constant(value=5)]),
                              Compare(
                                  left=Name(id='n', ctx=Load()),
                                  ops=[
                                      Lt()],
                                  comparators=[
                                      Constant(value=10)])],
                          is_async=0)]))

          >>> print(ast.dump(ast.parse('[i async for i in soc]', mode='eval'),
          ...                indent=4)) # Async comprehension
          Expression(
              body=ListComp(
                  elt=Name(id='i', ctx=Load()),
                  generators=[
                      comprehension(
                          target=Name(id='i', ctx=Store()),
                          iter=Name(id='soc', ctx=Load()),
                          is_async=1)]))


File: python.info,  Node: Statements,  Next: Control flow,  Prev: Expressions<2>,  Up: Node classes

5.32.1.9 Statements
...................

 -- Classe: ast.Assign (targets, value, type_comment)

     An assignment.  ‘targets’ is a list of nodes, and ‘value’ is a
     single node.

     Multiple nodes in ‘targets’ represents assigning the same value to
     each.  Unpacking is represented by putting a *note Tuple: 4a7d. or
     *note List: 4a7c. within ‘targets’.

      -- Attributo: type_comment

          ‘type_comment’ is an optional string with the type annotation
          as a comment.

          >>> print(ast.dump(ast.parse('a = b = 1'), indent=4)) # Multiple assignment
          Module(
              body=[
                  Assign(
                      targets=[
                          Name(id='a', ctx=Store()),
                          Name(id='b', ctx=Store())],
                      value=Constant(value=1))])

          >>> print(ast.dump(ast.parse('a,b = c'), indent=4)) # Unpacking
          Module(
              body=[
                  Assign(
                      targets=[
                          Tuple(
                              elts=[
                                  Name(id='a', ctx=Store()),
                                  Name(id='b', ctx=Store())],
                              ctx=Store())],
                      value=Name(id='c', ctx=Load()))])

 -- Classe: ast.AnnAssign (target, annotation, value, simple)

     An assignment with a type annotation.  ‘target’ is a single node
     and can be a *note Name: 1d0a, an *note Attribute: 4a79. or a *note
     Subscript: 4a7a.  ‘annotation’ is the annotation, such as a *note
     Constant: 2ef. or *note Name: 1d0a. node.  ‘value’ is a single
     optional node.

     ‘simple’ is always either 0 (indicating a «complex» target) or 1
     (indicating a «simple» target).  A «simple» target consists solely
     of a *note Name: 1d0a. node that does not appear between
     parentheses; all other targets are considered complex.  Only simple
     targets appear in the *note __annotations__: 458. dictionary of
     modules and classes.

          >>> print(ast.dump(ast.parse('c: int'), indent=4))
          Module(
              body=[
                  AnnAssign(
                      target=Name(id='c', ctx=Store()),
                      annotation=Name(id='int', ctx=Load()),
                      simple=1)])

          >>> print(ast.dump(ast.parse('(a): int = 1'), indent=4)) # Annotation with parenthesis
          Module(
              body=[
                  AnnAssign(
                      target=Name(id='a', ctx=Store()),
                      annotation=Name(id='int', ctx=Load()),
                      value=Constant(value=1),
                      simple=0)])

          >>> print(ast.dump(ast.parse('a.b: int'), indent=4)) # Attribute annotation
          Module(
              body=[
                  AnnAssign(
                      target=Attribute(
                          value=Name(id='a', ctx=Load()),
                          attr='b',
                          ctx=Store()),
                      annotation=Name(id='int', ctx=Load()),
                      simple=0)])

          >>> print(ast.dump(ast.parse('a[1]: int'), indent=4)) # Subscript annotation
          Module(
              body=[
                  AnnAssign(
                      target=Subscript(
                          value=Name(id='a', ctx=Load()),
                          slice=Constant(value=1),
                          ctx=Store()),
                      annotation=Name(id='int', ctx=Load()),
                      simple=0)])

 -- Classe: ast.AugAssign (target, op, value)

     Augmented assignment, such as ‘a += 1’.  In the following example,
     ‘target’ is a *note Name: 1d0a. node for ‘x’ (with the *note Store:
     4b6a. context), ‘op’ is *note Add: 4b6f, and ‘value’ is a *note
     Constant: 2ef. with value for 1.

     The ‘target’ attribute cannot be of class *note Tuple: 4a7d. or
     *note List: 4a7c, unlike the targets of *note Assign: 4b7f.

          >>> print(ast.dump(ast.parse('x += 2'), indent=4))
          Module(
              body=[
                  AugAssign(
                      target=Name(id='x', ctx=Store()),
                      op=Add(),
                      value=Constant(value=2))])

 -- Classe: ast.Raise (exc, cause)

     A ‘raise’ statement.  ‘exc’ is the exception object to be raised,
     normally a *note Call: 4a78. or *note Name: 1d0a, or ‘None’ for a
     standalone ‘raise’.  ‘cause’ is the optional part for ‘y’ in ‘raise
     x from y’.

          >>> print(ast.dump(ast.parse('raise x from y'), indent=4))
          Module(
              body=[
                  Raise(
                      exc=Name(id='x', ctx=Load()),
                      cause=Name(id='y', ctx=Load()))])

 -- Classe: ast.Assert (test, msg)

     An assertion.  ‘test’ holds the condition, such as a *note Compare:
     4a6d. node.  ‘msg’ holds the failure message.

          >>> print(ast.dump(ast.parse('assert x,y'), indent=4))
          Module(
              body=[
                  Assert(
                      test=Name(id='x', ctx=Load()),
                      msg=Name(id='y', ctx=Load()))])

 -- Classe: ast.Delete (targets)

     Represents a ‘del’ statement.  ‘targets’ is a list of nodes, such
     as *note Name: 1d0a, *note Attribute: 4a79. or *note Subscript:
     4a7a. nodes.

          >>> print(ast.dump(ast.parse('del x,y,z'), indent=4))
          Module(
              body=[
                  Delete(
                      targets=[
                          Name(id='x', ctx=Del()),
                          Name(id='y', ctx=Del()),
                          Name(id='z', ctx=Del())])])

 -- Classe: ast.Pass

     A ‘pass’ statement.

          >>> print(ast.dump(ast.parse('pass'), indent=4))
          Module(
              body=[
                  Pass()])

 -- Classe: ast.TypeAlias (name, type_params, value)

     A *note type alias: 684. created through the *note type: 66d.
     statement.  ‘name’ is the name of the alias, ‘type_params’ is a
     list of *note type parameters: 4b8b, and ‘value’ is the value of
     the type alias.

          >>> print(ast.dump(ast.parse('type Alias = int'), indent=4))
          Module(
              body=[
                  TypeAlias(
                      name=Name(id='Alias', ctx=Store()),
                      value=Name(id='int', ctx=Load()))])

     Added in version 3.12.

Other statements which are only applicable inside functions or loops are
described in other sections.

* Menu:

* Imports::


File: python.info,  Node: Imports,  Up: Statements

5.32.1.10 Imports
.................

 -- Classe: ast.Import (names)

     An import statement.  ‘names’ is a list of *note alias: 1c5c.
     nodes.

          >>> print(ast.dump(ast.parse('import x,y,z'), indent=4))
          Module(
              body=[
                  Import(
                      names=[
                          alias(name='x'),
                          alias(name='y'),
                          alias(name='z')])])

 -- Classe: ast.ImportFrom (module, names, level)

     Represents ‘from x import y’.  ‘module’ is a raw string of the
     “from” name, without any leading dots, or ‘None’ for statements
     such as ‘from . import foo’.  ‘level’ is an integer holding the
     level of the relative import (0 means absolute import).

          >>> print(ast.dump(ast.parse('from y import x,y,z'), indent=4))
          Module(
              body=[
                  ImportFrom(
                      module='y',
                      names=[
                          alias(name='x'),
                          alias(name='y'),
                          alias(name='z')],
                      level=0)])

 -- Classe: ast.alias (name, asname)

     Both parameters are raw strings of the names.  ‘asname’ can be
     ‘None’ if the regular name is to be used.

          >>> print(ast.dump(ast.parse('from ..foo.bar import a as b, c'), indent=4))
          Module(
              body=[
                  ImportFrom(
                      module='foo.bar',
                      names=[
                          alias(name='a', asname='b'),
                          alias(name='c')],
                      level=2)])


File: python.info,  Node: Control flow,  Next: Pattern matching,  Prev: Statements,  Up: Node classes

5.32.1.11 Control flow
......................

     Nota: Optional clauses such as ‘else’ are stored as an empty list
     if they’re not present.

 -- Classe: ast.If (test, body, orelse)

     An ‘if’ statement.  ‘test’ holds a single node, such as a *note
     Compare: 4a6d. node.  ‘body’ and ‘orelse’ each hold a list of
     nodes.

     ‘elif’ clauses don’t have a special representation in the AST, but
     rather appear as extra *note If: 4b90. nodes within the ‘orelse’
     section of the previous one.

          >>> print(ast.dump(ast.parse("""
          ... if x:
          ...    ...
          ... elif y:
          ...    ...
          ... else:
          ...    ...
          ... """), indent=4))
          Module(
              body=[
                  If(
                      test=Name(id='x', ctx=Load()),
                      body=[
                          Expr(
                              value=Constant(value=Ellipsis))],
                      orelse=[
                          If(
                              test=Name(id='y', ctx=Load()),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))],
                              orelse=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])])])

 -- Classe: ast.For (target, iter, body, orelse, type_comment)

     A ‘for’ loop.  ‘target’ holds the variable(s) the loop assigns to,
     as a single *note Name: 1d0a, *note Tuple: 4a7d, *note List: 4a7c,
     *note Attribute: 4a79. or *note Subscript: 4a7a. node.  ‘iter’
     holds the item to be looped over, again as a single node.  ‘body’
     and ‘orelse’ contain lists of nodes to execute.  Those in ‘orelse’
     are executed if the loop finishes normally, rather than via a
     ‘break’ statement.

      -- Attributo: type_comment

          ‘type_comment’ is an optional string with the type annotation
          as a comment.

          >>> print(ast.dump(ast.parse("""
          ... for x in y:
          ...     ...
          ... else:
          ...     ...
          ... """), indent=4))
          Module(
              body=[
                  For(
                      target=Name(id='x', ctx=Store()),
                      iter=Name(id='y', ctx=Load()),
                      body=[
                          Expr(
                              value=Constant(value=Ellipsis))],
                      orelse=[
                          Expr(
                              value=Constant(value=Ellipsis))])])

 -- Classe: ast.While (test, body, orelse)

     A ‘while’ loop.  ‘test’ holds the condition, such as a *note
     Compare: 4a6d. node.

          >>> print(ast.dump(ast.parse("""
          ... while x:
          ...    ...
          ... else:
          ...    ...
          ... """), indent=4))
          Module(
              body=[
                  While(
                      test=Name(id='x', ctx=Load()),
                      body=[
                          Expr(
                              value=Constant(value=Ellipsis))],
                      orelse=[
                          Expr(
                              value=Constant(value=Ellipsis))])])

 -- Classe: ast.Break
 -- Classe: ast.Continue

     The ‘break’ and ‘continue’ statements.

          >>> print(ast.dump(ast.parse("""\
          ... for a in b:
          ...     if a > 5:
          ...         break
          ...     else:
          ...         continue
          ...
          ... """), indent=4))
          Module(
              body=[
                  For(
                      target=Name(id='a', ctx=Store()),
                      iter=Name(id='b', ctx=Load()),
                      body=[
                          If(
                              test=Compare(
                                  left=Name(id='a', ctx=Load()),
                                  ops=[
                                      Gt()],
                                  comparators=[
                                      Constant(value=5)]),
                              body=[
                                  Break()],
                              orelse=[
                                  Continue()])])])

 -- Classe: ast.Try (body, handlers, orelse, finalbody)

     ‘try’ blocks.  All attributes are list of nodes to execute, except
     for ‘handlers’, which is a list of *note ExceptHandler: 4b97.
     nodes.

          >>> print(ast.dump(ast.parse("""
          ... try:
          ...    ...
          ... except Exception:
          ...    ...
          ... except OtherException as e:
          ...    ...
          ... else:
          ...    ...
          ... finally:
          ...    ...
          ... """), indent=4))
          Module(
              body=[
                  Try(
                      body=[
                          Expr(
                              value=Constant(value=Ellipsis))],
                      handlers=[
                          ExceptHandler(
                              type=Name(id='Exception', ctx=Load()),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))]),
                          ExceptHandler(
                              type=Name(id='OtherException', ctx=Load()),
                              name='e',
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])],
                      orelse=[
                          Expr(
                              value=Constant(value=Ellipsis))],
                      finalbody=[
                          Expr(
                              value=Constant(value=Ellipsis))])])

 -- Classe: ast.TryStar (body, handlers, orelse, finalbody)

     ‘try’ blocks which are followed by ‘except*’ clauses.  The
     attributes are the same as for *note Try: 4b96. but the *note
     ExceptHandler: 4b97. nodes in ‘handlers’ are interpreted as
     ‘except*’ blocks rather then ‘except’.

          >>> print(ast.dump(ast.parse("""
          ... try:
          ...    ...
          ... except* Exception:
          ...    ...
          ... """), indent=4))
          Module(
              body=[
                  TryStar(
                      body=[
                          Expr(
                              value=Constant(value=Ellipsis))],
                      handlers=[
                          ExceptHandler(
                              type=Name(id='Exception', ctx=Load()),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])])])

     Added in version 3.11.

 -- Classe: ast.ExceptHandler (type, name, body)

     A single ‘except’ clause.  ‘type’ is the exception type it will
     match, typically a *note Name: 1d0a. node (or ‘None’ for a
     catch-all ‘except:’ clause).  ‘name’ is a raw string for the name
     to hold the exception, or ‘None’ if the clause doesn’t have ‘as
     foo’.  ‘body’ is a list of nodes.

          >>> print(ast.dump(ast.parse("""\
          ... try:
          ...     a + 1
          ... except TypeError:
          ...     pass
          ... """), indent=4))
          Module(
              body=[
                  Try(
                      body=[
                          Expr(
                              value=BinOp(
                                  left=Name(id='a', ctx=Load()),
                                  op=Add(),
                                  right=Constant(value=1)))],
                      handlers=[
                          ExceptHandler(
                              type=Name(id='TypeError', ctx=Load()),
                              body=[
                                  Pass()])])])

 -- Classe: ast.With (items, body, type_comment)

     A ‘with’ block.  ‘items’ is a list of *note withitem: 4b9a. nodes
     representing the context managers, and ‘body’ is the indented block
     inside the context.

      -- Attributo: type_comment

          ‘type_comment’ is an optional string with the type annotation
          as a comment.

 -- Classe: ast.withitem (context_expr, optional_vars)

     A single context manager in a ‘with’ block.  ‘context_expr’ is the
     context manager, often a *note Call: 4a78. node.  ‘optional_vars’
     is a *note Name: 1d0a, *note Tuple: 4a7d. or *note List: 4a7c. for
     the ‘as foo’ part, or ‘None’ if that isn’t used.

          >>> print(ast.dump(ast.parse("""\
          ... with a as b, c as d:
          ...    something(b, d)
          ... """), indent=4))
          Module(
              body=[
                  With(
                      items=[
                          withitem(
                              context_expr=Name(id='a', ctx=Load()),
                              optional_vars=Name(id='b', ctx=Store())),
                          withitem(
                              context_expr=Name(id='c', ctx=Load()),
                              optional_vars=Name(id='d', ctx=Store()))],
                      body=[
                          Expr(
                              value=Call(
                                  func=Name(id='something', ctx=Load()),
                                  args=[
                                      Name(id='b', ctx=Load()),
                                      Name(id='d', ctx=Load())]))])])


File: python.info,  Node: Pattern matching,  Next: Type annotations,  Prev: Control flow,  Up: Node classes

5.32.1.12 Pattern matching
..........................

 -- Classe: ast.Match (subject, cases)

     A ‘match’ statement.  ‘subject’ holds the subject of the match (the
     object that is being matched against the cases) and ‘cases’
     contains an iterable of *note match_case: 4b9e. nodes with the
     different cases.

     Added in version 3.10.

 -- Classe: ast.match_case (pattern, guard, body)

     A single case pattern in a ‘match’ statement.  ‘pattern’ contains
     the match pattern that the subject will be matched against.  Note
     that the *note AST: 4c4. nodes produced for patterns differ from
     those produced for expressions, even when they share the same
     syntax.

     The ‘guard’ attribute contains an expression that will be evaluated
     if the pattern matches the subject.

     ‘body’ contains a list of nodes to execute if the pattern matches
     and the result of evaluating the guard expression is true.

          >>> print(ast.dump(ast.parse("""
          ... match x:
          ...     case [x] if x>0:
          ...         ...
          ...     case tuple():
          ...         ...
          ... """), indent=4))
          Module(
              body=[
                  Match(
                      subject=Name(id='x', ctx=Load()),
                      cases=[
                          match_case(
                              pattern=MatchSequence(
                                  patterns=[
                                      MatchAs(name='x')]),
                              guard=Compare(
                                  left=Name(id='x', ctx=Load()),
                                  ops=[
                                      Gt()],
                                  comparators=[
                                      Constant(value=0)]),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))]),
                          match_case(
                              pattern=MatchClass(
                                  cls=Name(id='tuple', ctx=Load())),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])])])

     Added in version 3.10.

 -- Classe: ast.MatchValue (value)

     A match literal or value pattern that compares by equality.
     ‘value’ is an expression node.  Permitted value nodes are
     restricted as described in the match statement documentation.  This
     pattern succeeds if the match subject is equal to the evaluated
     value.

          >>> print(ast.dump(ast.parse("""
          ... match x:
          ...     case "Relevant":
          ...         ...
          ... """), indent=4))
          Module(
              body=[
                  Match(
                      subject=Name(id='x', ctx=Load()),
                      cases=[
                          match_case(
                              pattern=MatchValue(
                                  value=Constant(value='Relevant')),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])])])

     Added in version 3.10.

 -- Classe: ast.MatchSingleton (value)

     A match literal pattern that compares by identity.  ‘value’ is the
     singleton to be compared against: ‘None’, ‘True’, or ‘False’.  This
     pattern succeeds if the match subject is the given constant.

          >>> print(ast.dump(ast.parse("""
          ... match x:
          ...     case None:
          ...         ...
          ... """), indent=4))
          Module(
              body=[
                  Match(
                      subject=Name(id='x', ctx=Load()),
                      cases=[
                          match_case(
                              pattern=MatchSingleton(value=None),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])])])

     Added in version 3.10.

 -- Classe: ast.MatchSequence (patterns)

     A match sequence pattern.  ‘patterns’ contains the patterns to be
     matched against the subject elements if the subject is a sequence.
     Matches a variable length sequence if one of the subpatterns is a
     ‘MatchStar’ node, otherwise matches a fixed length sequence.

          >>> print(ast.dump(ast.parse("""
          ... match x:
          ...     case [1, 2]:
          ...         ...
          ... """), indent=4))
          Module(
              body=[
                  Match(
                      subject=Name(id='x', ctx=Load()),
                      cases=[
                          match_case(
                              pattern=MatchSequence(
                                  patterns=[
                                      MatchValue(
                                          value=Constant(value=1)),
                                      MatchValue(
                                          value=Constant(value=2))]),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])])])

     Added in version 3.10.

 -- Classe: ast.MatchStar (name)

     Matches the rest of the sequence in a variable length match
     sequence pattern.  If ‘name’ is not ‘None’, a list containing the
     remaining sequence elements is bound to that name if the overall
     sequence pattern is successful.

          >>> print(ast.dump(ast.parse("""
          ... match x:
          ...     case [1, 2, *rest]:
          ...         ...
          ...     case [*_]:
          ...         ...
          ... """), indent=4))
          Module(
              body=[
                  Match(
                      subject=Name(id='x', ctx=Load()),
                      cases=[
                          match_case(
                              pattern=MatchSequence(
                                  patterns=[
                                      MatchValue(
                                          value=Constant(value=1)),
                                      MatchValue(
                                          value=Constant(value=2)),
                                      MatchStar(name='rest')]),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))]),
                          match_case(
                              pattern=MatchSequence(
                                  patterns=[
                                      MatchStar()]),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])])])

     Added in version 3.10.

 -- Classe: ast.MatchMapping (keys, patterns, rest)

     A match mapping pattern.  ‘keys’ is a sequence of expression nodes.
     ‘patterns’ is a corresponding sequence of pattern nodes.  ‘rest’ is
     an optional name that can be specified to capture the remaining
     mapping elements.  Permitted key expressions are restricted as
     described in the match statement documentation.

     This pattern succeeds if the subject is a mapping, all evaluated
     key expressions are present in the mapping, and the value
     corresponding to each key matches the corresponding subpattern.  If
     ‘rest’ is not ‘None’, a dict containing the remaining mapping
     elements is bound to that name if the overall mapping pattern is
     successful.

          >>> print(ast.dump(ast.parse("""
          ... match x:
          ...     case {1: _, 2: _}:
          ...         ...
          ...     case {**rest}:
          ...         ...
          ... """), indent=4))
          Module(
              body=[
                  Match(
                      subject=Name(id='x', ctx=Load()),
                      cases=[
                          match_case(
                              pattern=MatchMapping(
                                  keys=[
                                      Constant(value=1),
                                      Constant(value=2)],
                                  patterns=[
                                      MatchAs(),
                                      MatchAs()]),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))]),
                          match_case(
                              pattern=MatchMapping(rest='rest'),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])])])

     Added in version 3.10.

 -- Classe: ast.MatchClass (cls, patterns, kwd_attrs, kwd_patterns)

     A match class pattern.  ‘cls’ is an expression giving the nominal
     class to be matched.  ‘patterns’ is a sequence of pattern nodes to
     be matched against the class defined sequence of pattern matching
     attributes.  ‘kwd_attrs’ is a sequence of additional attributes to
     be matched (specified as keyword arguments in the class pattern),
     ‘kwd_patterns’ are the corresponding patterns (specified as keyword
     values in the class pattern).

     This pattern succeeds if the subject is an instance of the
     nominated class, all positional patterns match the corresponding
     class-defined attributes, and any specified keyword attributes
     match their corresponding pattern.

     Note: classes may define a property that returns self in order to
     match a pattern node against the instance being matched.  Several
     builtin types are also matched that way, as described in the match
     statement documentation.

          >>> print(ast.dump(ast.parse("""
          ... match x:
          ...     case Point2D(0, 0):
          ...         ...
          ...     case Point3D(x=0, y=0, z=0):
          ...         ...
          ... """), indent=4))
          Module(
              body=[
                  Match(
                      subject=Name(id='x', ctx=Load()),
                      cases=[
                          match_case(
                              pattern=MatchClass(
                                  cls=Name(id='Point2D', ctx=Load()),
                                  patterns=[
                                      MatchValue(
                                          value=Constant(value=0)),
                                      MatchValue(
                                          value=Constant(value=0))]),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))]),
                          match_case(
                              pattern=MatchClass(
                                  cls=Name(id='Point3D', ctx=Load()),
                                  kwd_attrs=[
                                      'x',
                                      'y',
                                      'z'],
                                  kwd_patterns=[
                                      MatchValue(
                                          value=Constant(value=0)),
                                      MatchValue(
                                          value=Constant(value=0)),
                                      MatchValue(
                                          value=Constant(value=0))]),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])])])

     Added in version 3.10.

 -- Classe: ast.MatchAs (pattern, name)

     A match «as-pattern», capture pattern or wildcard pattern.
     ‘pattern’ contains the match pattern that the subject will be
     matched against.  If the pattern is ‘None’, the node represents a
     capture pattern (i.e a bare name) and will always succeed.

     The ‘name’ attribute contains the name that will be bound if the
     pattern is successful.  If ‘name’ is ‘None’, ‘pattern’ must also be
     ‘None’ and the node represents the wildcard pattern.

          >>> print(ast.dump(ast.parse("""
          ... match x:
          ...     case [x] as y:
          ...         ...
          ...     case _:
          ...         ...
          ... """), indent=4))
          Module(
              body=[
                  Match(
                      subject=Name(id='x', ctx=Load()),
                      cases=[
                          match_case(
                              pattern=MatchAs(
                                  pattern=MatchSequence(
                                      patterns=[
                                          MatchAs(name='x')]),
                                  name='y'),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))]),
                          match_case(
                              pattern=MatchAs(),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])])])

     Added in version 3.10.

 -- Classe: ast.MatchOr (patterns)

     A match «or-pattern».  An or-pattern matches each of its
     subpatterns in turn to the subject, until one succeeds.  The
     or-pattern is then deemed to succeed.  If none of the subpatterns
     succeed the or-pattern fails.  The ‘patterns’ attribute contains a
     list of match pattern nodes that will be matched against the
     subject.

          >>> print(ast.dump(ast.parse("""
          ... match x:
          ...     case [x] | (y):
          ...         ...
          ... """), indent=4))
          Module(
              body=[
                  Match(
                      subject=Name(id='x', ctx=Load()),
                      cases=[
                          match_case(
                              pattern=MatchOr(
                                  patterns=[
                                      MatchSequence(
                                          patterns=[
                                              MatchAs(name='x')]),
                                      MatchAs(name='y')]),
                              body=[
                                  Expr(
                                      value=Constant(value=Ellipsis))])])])

     Added in version 3.10.


File: python.info,  Node: Type annotations,  Next: Type parameters,  Prev: Pattern matching,  Up: Node classes

5.32.1.13 Type annotations
..........................

 -- Classe: ast.TypeIgnore (lineno, tag)

     A ‘# type: ignore’ comment located at 'lineno'.  'tag' is the
     optional tag specified by the form ‘# type: ignore <tag>’.

          >>> print(ast.dump(ast.parse('x = 1 # type: ignore', type_comments=True), indent=4))
          Module(
              body=[
                  Assign(
                      targets=[
                          Name(id='x', ctx=Store())],
                      value=Constant(value=1))],
              type_ignores=[
                  TypeIgnore(lineno=1, tag='')])
          >>> print(ast.dump(ast.parse('x: bool = 1 # type: ignore[assignment]', type_comments=True), indent=4))
          Module(
              body=[
                  AnnAssign(
                      target=Name(id='x', ctx=Store()),
                      annotation=Name(id='bool', ctx=Load()),
                      value=Constant(value=1),
                      simple=1)],
              type_ignores=[
                  TypeIgnore(lineno=1, tag='[assignment]')])

          Nota: ‘TypeIgnore’ nodes are not generated when the
          'type_comments' parameter is set to ‘False’ (default).  See
          *note ast.parse(): 1c2. for more details.

     Added in version 3.8.


File: python.info,  Node: Type parameters,  Next: Function and class definitions,  Prev: Type annotations,  Up: Node classes

5.32.1.14 Type parameters
.........................

*note Type parameters: 5ad. can exist on classes, functions, and type
aliases.

 -- Classe: ast.TypeVar (name, bound, default_value)

     A *note typing.TypeVar: 487.  ‘name’ is the name of the type
     variable.  ‘bound’ is the bound or constraints, if any.  If ‘bound’
     is a *note Tuple: 4a7d, it represents constraints; otherwise it
     represents the bound.  ‘default_value’ is the default value; if the
     ‘TypeVar’ has no default, this attribute will be set to ‘None’.

          >>> print(ast.dump(ast.parse("type Alias[T: int = bool] = list[T]"), indent=4))
          Module(
              body=[
                  TypeAlias(
                      name=Name(id='Alias', ctx=Store()),
                      type_params=[
                          TypeVar(
                              name='T',
                              bound=Name(id='int', ctx=Load()),
                              default_value=Name(id='bool', ctx=Load()))],
                      value=Subscript(
                          value=Name(id='list', ctx=Load()),
                          slice=Name(id='T', ctx=Load()),
                          ctx=Load()))])

     Added in version 3.12.

     Cambiato nella versione 3.13: Added the 'default_value' parameter.

 -- Classe: ast.ParamSpec (name, default_value)

     A *note typing.ParamSpec: 488.  ‘name’ is the name of the parameter
     specification.  ‘default_value’ is the default value; if the
     ‘ParamSpec’ has no default, this attribute will be set to ‘None’.

          >>> print(ast.dump(ast.parse("type Alias[**P = [int, str]] = Callable[P, int]"), indent=4))
          Module(
              body=[
                  TypeAlias(
                      name=Name(id='Alias', ctx=Store()),
                      type_params=[
                          ParamSpec(
                              name='P',
                              default_value=List(
                                  elts=[
                                      Name(id='int', ctx=Load()),
                                      Name(id='str', ctx=Load())],
                                  ctx=Load()))],
                      value=Subscript(
                          value=Name(id='Callable', ctx=Load()),
                          slice=Tuple(
                              elts=[
                                  Name(id='P', ctx=Load()),
                                  Name(id='int', ctx=Load())],
                              ctx=Load()),
                          ctx=Load()))])

     Added in version 3.12.

     Cambiato nella versione 3.13: Added the 'default_value' parameter.

 -- Classe: ast.TypeVarTuple (name, default_value)

     A *note typing.TypeVarTuple: 489.  ‘name’ is the name of the type
     variable tuple.  ‘default_value’ is the default value; if the
     ‘TypeVarTuple’ has no default, this attribute will be set to
     ‘None’.

          >>> print(ast.dump(ast.parse("type Alias[*Ts = ()] = tuple[*Ts]"), indent=4))
          Module(
              body=[
                  TypeAlias(
                      name=Name(id='Alias', ctx=Store()),
                      type_params=[
                          TypeVarTuple(
                              name='Ts',
                              default_value=Tuple(ctx=Load()))],
                      value=Subscript(
                          value=Name(id='tuple', ctx=Load()),
                          slice=Tuple(
                              elts=[
                                  Starred(
                                      value=Name(id='Ts', ctx=Load()),
                                      ctx=Load())],
                              ctx=Load()),
                          ctx=Load()))])

     Added in version 3.12.

     Cambiato nella versione 3.13: Added the 'default_value' parameter.


File: python.info,  Node: Function and class definitions,  Next: Async and await,  Prev: Type parameters,  Up: Node classes

5.32.1.15 Function and class definitions
........................................

 -- Classe: ast.FunctionDef (name, args, body, decorator_list, returns,
          type_comment, type_params)

     A function definition.

        * ‘name’ is a raw string of the function name.

        * ‘args’ is an *note arguments: 4bad. node.

        * ‘body’ is the list of nodes inside the function.

        * ‘decorator_list’ is the list of decorators to be applied,
          stored outermost first (i.e.  the first in the list will be
          applied last).

        * ‘returns’ is the return annotation.

        * ‘type_params’ is a list of *note type parameters: 4b8b.

      -- Attributo: type_comment

          ‘type_comment’ is an optional string with the type annotation
          as a comment.

     Cambiato nella versione 3.12: Added ‘type_params’.

 -- Classe: ast.Lambda (args, body)

     ‘lambda’ is a minimal function definition that can be used inside
     an expression.  Unlike *note FunctionDef: 1a60, ‘body’ holds a
     single node.

          >>> print(ast.dump(ast.parse('lambda x,y: ...'), indent=4))
          Module(
              body=[
                  Expr(
                      value=Lambda(
                          args=arguments(
                              args=[
                                  arg(arg='x'),
                                  arg(arg='y')]),
                          body=Constant(value=Ellipsis)))])

 -- Classe: ast.arguments (posonlyargs, args, vararg, kwonlyargs,
          kw_defaults, kwarg, defaults)

     The arguments for a function.

        * ‘posonlyargs’, ‘args’ and ‘kwonlyargs’ are lists of *note arg:
          4baf. nodes.

        * ‘vararg’ and ‘kwarg’ are single *note arg: 4baf. nodes,
          referring to the ‘*args, **kwargs’ parameters.

        * ‘kw_defaults’ is a list of default values for keyword-only
          arguments.  If one is ‘None’, the corresponding argument is
          required.

        * ‘defaults’ is a list of default values for arguments that can
          be passed positionally.  If there are fewer defaults, they
          correspond to the last n arguments.

 -- Classe: ast.arg (arg, annotation, type_comment)

     A single argument in a list.  ‘arg’ is a raw string of the argument
     name; ‘annotation’ is its annotation, such as a *note Name: 1d0a.
     node.

      -- Attributo: type_comment

          ‘type_comment’ is an optional string with the type annotation
          as a comment

          >>> print(ast.dump(ast.parse("""\
          ... @decorator1
          ... @decorator2
          ... def f(a: 'annotation', b=1, c=2, *d, e, f=3, **g) -> 'return annotation':
          ...     pass
          ... """), indent=4))
          Module(
              body=[
                  FunctionDef(
                      name='f',
                      args=arguments(
                          args=[
                              arg(
                                  arg='a',
                                  annotation=Constant(value='annotation')),
                              arg(arg='b'),
                              arg(arg='c')],
                          vararg=arg(arg='d'),
                          kwonlyargs=[
                              arg(arg='e'),
                              arg(arg='f')],
                          kw_defaults=[
                              None,
                              Constant(value=3)],
                          kwarg=arg(arg='g'),
                          defaults=[
                              Constant(value=1),
                              Constant(value=2)]),
                      body=[
                          Pass()],
                      decorator_list=[
                          Name(id='decorator1', ctx=Load()),
                          Name(id='decorator2', ctx=Load())],
                      returns=Constant(value='return annotation'))])

 -- Classe: ast.Return (value)

     A ‘return’ statement.

          >>> print(ast.dump(ast.parse('return 4'), indent=4))
          Module(
              body=[
                  Return(
                      value=Constant(value=4))])

 -- Classe: ast.Yield (value)
 -- Classe: ast.YieldFrom (value)

     A ‘yield’ or ‘yield from’ expression.  Because these are
     expressions, they must be wrapped in an *note Expr: 4b6e. node if
     the value sent back is not used.

          >>> print(ast.dump(ast.parse('yield x'), indent=4))
          Module(
              body=[
                  Expr(
                      value=Yield(
                          value=Name(id='x', ctx=Load())))])

          >>> print(ast.dump(ast.parse('yield from x'), indent=4))
          Module(
              body=[
                  Expr(
                      value=YieldFrom(
                          value=Name(id='x', ctx=Load())))])

 -- Classe: ast.Global (names)
 -- Classe: ast.Nonlocal (names)

     ‘global’ and ‘nonlocal’ statements.  ‘names’ is a list of raw
     strings.

          >>> print(ast.dump(ast.parse('global x,y,z'), indent=4))
          Module(
              body=[
                  Global(
                      names=[
                          'x',
                          'y',
                          'z'])])

          >>> print(ast.dump(ast.parse('nonlocal x,y,z'), indent=4))
          Module(
              body=[
                  Nonlocal(
                      names=[
                          'x',
                          'y',
                          'z'])])

 -- Classe: ast.ClassDef (name, bases, keywords, body, decorator_list,
          type_params)

     A class definition.

        * ‘name’ is a raw string for the class name

        * ‘bases’ is a list of nodes for explicitly specified base
          classes.

        * ‘keywords’ is a list of *note keyword: 4b7e. nodes,
          principally for “metaclass”.  Other keywords will be passed to
          the metaclass, as per PEP 3115(1).

        * ‘body’ is a list of nodes representing the code within the
          class definition.

        * ‘decorator_list’ is a list of nodes, as in *note FunctionDef:
          1a60.

        * ‘type_params’ is a list of *note type parameters: 4b8b.

          >>> print(ast.dump(ast.parse("""\
          ... @decorator1
          ... @decorator2
          ... class Foo(base1, base2, metaclass=meta):
          ...     pass
          ... """), indent=4))
          Module(
              body=[
                  ClassDef(
                      name='Foo',
                      bases=[
                          Name(id='base1', ctx=Load()),
                          Name(id='base2', ctx=Load())],
                      keywords=[
                          keyword(
                              arg='metaclass',
                              value=Name(id='meta', ctx=Load()))],
                      body=[
                          Pass()],
                      decorator_list=[
                          Name(id='decorator1', ctx=Load()),
                          Name(id='decorator2', ctx=Load())])])

     Cambiato nella versione 3.12: Added ‘type_params’.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3115/


File: python.info,  Node: Async and await,  Prev: Function and class definitions,  Up: Node classes

5.32.1.16 Async and await
.........................

 -- Classe: ast.AsyncFunctionDef (name, args, body, decorator_list,
          returns, type_comment, type_params)

     An ‘async def’ function definition.  Has the same fields as *note
     FunctionDef: 1a60.

     Cambiato nella versione 3.12: Added ‘type_params’.

 -- Classe: ast.Await (value)

     An ‘await’ expression.  ‘value’ is what it waits for.  Only valid
     in the body of an *note AsyncFunctionDef: 1a5f.

     >>> print(ast.dump(ast.parse("""\
     ... async def f():
     ...     await other_func()
     ... """), indent=4))
     Module(
         body=[
             AsyncFunctionDef(
                 name='f',
                 args=arguments(),
                 body=[
                     Expr(
                         value=Await(
                             value=Call(
                                 func=Name(id='other_func', ctx=Load()))))])])

 -- Classe: ast.AsyncFor (target, iter, body, orelse, type_comment)
 -- Classe: ast.AsyncWith (items, body, type_comment)

     ‘async for’ loops and ‘async with’ context managers.  They have the
     same fields as *note For: 4b91. and *note With: 4b99, respectively.
     Only valid in the body of an *note AsyncFunctionDef: 1a5f.

     Nota: When a string is parsed by *note ast.parse(): 1c2, operator
     nodes (subclasses of ‘ast.operator’, ‘ast.unaryop’, ‘ast.cmpop’,
     ‘ast.boolop’ and ‘ast.expr_context’) on the returned tree will be
     singletons.  Changes to one will be reflected in all other
     occurrences of the same value (for example, *note ast.Add: 4b6f.).


File: python.info,  Node: ast helpers,  Next: Compiler flags<2>,  Prev: Node classes,  Up: ast — Abstract syntax trees

5.32.1.17 ‘ast’ helpers
.......................

Apart from the node classes, the *note ast: 9. module defines these
utility functions and classes for traversing abstract syntax trees:

 -- Funzione: ast.parse (source, filename='<unknown>', mode='exec', *,
          type_comments=False, feature_version=None, optimize=-1)

     Parse the source into an AST node.  Equivalent to ‘compile(source,
     filename, mode, flags=FLAGS_VALUE, optimize=optimize)’, where
     ‘FLAGS_VALUE’ is ‘ast.PyCF_ONLY_AST’ if ‘optimize <= 0’ and
     ‘ast.PyCF_OPTIMIZED_AST’ otherwise.

     If ‘type_comments=True’ is given, the parser is modified to check
     and return type comments as specified by PEP 484(1) and PEP 526(2).
     This is equivalent to adding *note ast.PyCF_TYPE_COMMENTS: 4bb8. to
     the flags passed to *note compile(): 4b2.  This will report syntax
     errors for misplaced type comments.  Without this flag, type
     comments will be ignored, and the ‘type_comment’ field on selected
     AST nodes will always be ‘None’.  In addition, the locations of ‘#
     type: ignore’ comments will be returned as the ‘type_ignores’
     attribute of *note Module: 4b63. (otherwise it is always an empty
     list).

     In addition, if ‘mode’ is ‘'func_type'’, the input syntax is
     modified to correspond to PEP 484(3) «signature type comments»,
     e.g.  ‘(str, int) -> List[str]’.

     Setting ‘feature_version’ to a tuple ‘(major, minor)’ will result
     in a «best-effort» attempt to parse using that Python version’s
     grammar.  For example, setting ‘feature_version=(3, 9)’ will
     attempt to disallow parsing of *note match: a10. statements.
     Currently ‘major’ must equal to ‘3’.  The lowest supported version
     is ‘(3, 7)’ (and this may increase in future Python versions); the
     highest is ‘sys.version_info[0:2]’.  «Best-effort» attempt means
     there is no guarantee that the parse (or success of the parse) is
     the same as when run on the Python version corresponding to
     ‘feature_version’.

     If source contains a null character (‘\0’), *note ValueError: 2ec.
     is raised.

          Avvertimento: Note that successfully parsing source code into
          an AST object doesn’t guarantee that the source code provided
          is valid Python code that can be executed as the compilation
          step can raise further *note SyntaxError: 18e. exceptions.
          For instance, the source ‘return 42’ generates a valid AST
          node for a return statement, but it cannot be compiled alone
          (it needs to be inside a function node).

          In particular, *note ast.parse(): 1c2. won’t do any scoping
          checks, which the compilation step does.

          Avvertimento: It is possible to crash the Python interpreter
          with a sufficiently large/complex string due to stack depth
          limitations in Python’s AST compiler.

     Cambiato nella versione 3.8: Added ‘type_comments’,
     ‘mode='func_type'’ and ‘feature_version’.

     Cambiato nella versione 3.13: The minimum supported version for
     ‘feature_version’ is now ‘(3, 7)’.  The ‘optimize’ argument was
     added.

 -- Funzione: ast.unparse (ast_obj)

     Unparse an *note ast.AST: 4c4. object and generate a string with
     code that would produce an equivalent *note ast.AST: 4c4. object if
     parsed back with *note ast.parse(): 1c2.

          Avvertimento: The produced code string will not necessarily be
          equal to the original code that generated the *note ast.AST:
          4c4. object (without any compiler optimizations, such as
          constant tuples/frozensets).

          Avvertimento: Trying to unparse a highly complex expression
          would result with *note RecursionError: f6a.

     Added in version 3.9.

 -- Funzione: ast.literal_eval (node_or_string)

     Evaluate an expression node or a string containing only a Python
     literal or container display.  The string or node provided may only
     consist of the following Python literal structures: strings, bytes,
     numbers, tuples, lists, dicts, sets, booleans, ‘None’ and
     ‘Ellipsis’.

     This can be used for evaluating strings containing Python values
     without the need to parse the values oneself.  It is not capable of
     evaluating arbitrarily complex expressions, for example involving
     operators or indexing.

     This function had been documented as «safe» in the past without
     defining what that meant.  That was misleading.  This is
     specifically designed not to execute Python code, unlike the more
     general *note eval(): 4a4.  There is no namespace, no name lookups,
     or ability to call out.  But it is not free from attack: A
     relatively small input can lead to memory exhaustion or to C stack
     exhaustion, crashing the process.  There is also the possibility
     for excessive CPU consumption denial of service on some inputs.
     Calling it on untrusted data is thus not recommended.

          Avvertimento: It is possible to crash the Python interpreter
          due to stack depth limitations in Python’s AST compiler.

          It can raise *note ValueError: 2ec, *note TypeError: 198,
          *note SyntaxError: 18e, *note MemoryError: 1786. and *note
          RecursionError: f6a. depending on the malformed input.

     Cambiato nella versione 3.2: Now allows bytes and set literals.

     Cambiato nella versione 3.9: Now supports creating empty sets with
     ‘'set()'’.

     Cambiato nella versione 3.10: For string inputs, leading spaces and
     tabs are now stripped.

 -- Funzione: ast.get_docstring (node, clean=True)

     Return the docstring of the given 'node' (which must be a *note
     FunctionDef: 1a60, *note AsyncFunctionDef: 1a5f, *note ClassDef:
     1a5e, or *note Module: 4b63. node), or ‘None’ if it has no
     docstring.  If 'clean' is true, clean up the docstring’s
     indentation with *note inspect.cleandoc(): 1a14.

     Cambiato nella versione 3.5: *note AsyncFunctionDef: 1a5f. is now
     supported.

 -- Funzione: ast.get_source_segment (source, node, *, padded=False)

     Get source code segment of the 'source' that generated 'node'.  If
     some location information (*note lineno: 4b5d, *note end_lineno:
     4b5f, *note col_offset: 4b5e, or *note end_col_offset: 4b60.) is
     missing, return ‘None’.

     If 'padded' is ‘True’, the first line of a multi-line statement
     will be padded with spaces to match its original position.

     Added in version 3.8.

 -- Funzione: ast.fix_missing_locations (node)

     When you compile a node tree with *note compile(): 4b2, the
     compiler expects *note lineno: 4b5d. and *note col_offset: 4b5e.
     attributes for every node that supports them.  This is rather
     tedious to fill in for generated nodes, so this helper adds these
     attributes recursively where not already set, by setting them to
     the values of the parent node.  It works recursively starting at
     'node'.

 -- Funzione: ast.increment_lineno (node, n=1)

     Increment the line number and end line number of each node in the
     tree starting at 'node' by 'n'.  This is useful to «move code» to a
     different location in a file.

 -- Funzione: ast.copy_location (new_node, old_node)

     Copy source location (*note lineno: 4b5d, *note col_offset: 4b5e,
     *note end_lineno: 4b5f, and *note end_col_offset: 4b60.) from
     'old_node' to 'new_node' if possible, and return 'new_node'.

 -- Funzione: ast.iter_fields (node)

     Yield a tuple of ‘(fieldname, value)’ for each field in
     ‘node._fields’ that is present on 'node'.

 -- Funzione: ast.iter_child_nodes (node)

     Yield all direct child nodes of 'node', that is, all fields that
     are nodes and all items of fields that are lists of nodes.

 -- Funzione: ast.walk (node)

     Recursively yield all descendant nodes in the tree starting at
     'node' (including 'node' itself), in no specified order.  This is
     useful if you only want to modify nodes in place and don’t care
     about the context.

 -- Classe: ast.NodeVisitor

     A node visitor base class that walks the abstract syntax tree and
     calls a visitor function for every node found.  This function may
     return a value which is forwarded by the *note visit(): 4bbe.
     method.

     This class is meant to be subclassed, with the subclass adding
     visitor methods.

      -- Metodo: visit (node)

          Visit a node.  The default implementation calls the method
          called ‘self.visit_CLASSNAME’ where 'classname' is the name of
          the node class, or *note generic_visit(): 4bbf. if that method
          doesn’t exist.

      -- Metodo: generic_visit (node)

          This visitor calls *note visit(): 4bbe. on all children of the
          node.

          Note that child nodes of nodes that have a custom visitor
          method won’t be visited unless the visitor calls *note
          generic_visit(): 4bbf. or visits them itself.

      -- Metodo: visit_Constant (node)

          Handles all constant nodes.

     Don’t use the *note NodeVisitor: 2f0. if you want to apply changes
     to nodes during traversal.  For this a special visitor exists
     (*note NodeTransformer: 4bc0.) that allows modifications.

     Deprecated since version 3.8, removed in version 3.14: Methods
     ‘visit_Num()’, ‘visit_Str()’, ‘visit_Bytes()’,
     ‘visit_NameConstant()’ and ‘visit_Ellipsis()’ will not be called in
     Python 3.14+.  Add the *note visit_Constant(): c65. method instead
     to handle all constant nodes.

 -- Classe: ast.NodeTransformer

     A *note NodeVisitor: 2f0. subclass that walks the abstract syntax
     tree and allows modification of nodes.

     The *note NodeTransformer: 4bc0. will walk the AST and use the
     return value of the visitor methods to replace or remove the old
     node.  If the return value of the visitor method is ‘None’, the
     node will be removed from its location, otherwise it is replaced
     with the return value.  The return value may be the original node
     in which case no replacement takes place.

     Here is an example transformer that rewrites all occurrences of
     name lookups (‘foo’) to ‘data['foo']’:

          class RewriteName(NodeTransformer):

              def visit_Name(self, node):
                  return Subscript(
                      value=Name(id='data', ctx=Load()),
                      slice=Constant(value=node.id),
                      ctx=node.ctx
                  )

     Keep in mind that if the node you’re operating on has child nodes
     you must either transform the child nodes yourself or call the
     *note generic_visit(): 4bbf. method for the node first.

     For nodes that were part of a collection of statements (that
     applies to all statement nodes), the visitor may also return a list
     of nodes rather than just a single node.

     If *note NodeTransformer: 4bc0. introduces new nodes (that weren’t
     part of original tree) without giving them location information
     (such as *note lineno: 4b5d.), *note fix_missing_locations(): 4bb9.
     should be called with the new sub-tree to recalculate the location
     information:

          tree = ast.parse('foo', mode='eval')
          new_tree = fix_missing_locations(RewriteName().visit(tree))

     Usually you use the transformer like this:

          node = YourTransformer().visit(node)

 -- Funzione: ast.dump (node, annotate_fields=True,
          include_attributes=False, *, indent=None, show_empty=False)

     Return a formatted dump of the tree in 'node'.  This is mainly
     useful for debugging purposes.  If 'annotate_fields' is true (by
     default), the returned string will show the names and the values
     for fields.  If 'annotate_fields' is false, the result string will
     be more compact by omitting unambiguous field names.  Attributes
     such as line numbers and column offsets are not dumped by default.
     If this is wanted, 'include_attributes' can be set to true.

     If 'indent' is a non-negative integer or string, then the tree will
     be pretty-printed with that indent level.  An indent level of 0,
     negative, or ‘""’ will only insert newlines.  ‘None’ (the default)
     selects the single line representation.  Using a positive integer
     indent indents that many spaces per level.  If 'indent' is a string
     (such as ‘"\t"’), that string is used to indent each level.

     If 'show_empty' is false (the default), optional empty lists will
     be omitted from the output.  Optional ‘None’ values are always
     omitted.

     Cambiato nella versione 3.9: Added the 'indent' option.

     Cambiato nella versione 3.13: Added the 'show_empty' option.

          >>> print(ast.dump(ast.parse("""\
          ... async def f():
          ...     await other_func()
          ... """), indent=4, show_empty=True))
          Module(
              body=[
                  AsyncFunctionDef(
                      name='f',
                      args=arguments(
                          posonlyargs=[],
                          args=[],
                          kwonlyargs=[],
                          kw_defaults=[],
                          defaults=[]),
                      body=[
                          Expr(
                              value=Await(
                                  value=Call(
                                      func=Name(id='other_func', ctx=Load()),
                                      args=[],
                                      keywords=[])))],
                      decorator_list=[],
                      type_params=[])],
              type_ignores=[])

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0526/

   (3) https://peps.python.org/pep-0484/


File: python.info,  Node: Compiler flags<2>,  Next: Command-line usage<7>,  Prev: ast helpers,  Up: ast — Abstract syntax trees

5.32.1.18 Compiler flags
........................

The following flags may be passed to *note compile(): 4b2. in order to
change effects on the compilation of a program:

 -- Dati: ast.PyCF_ALLOW_TOP_LEVEL_AWAIT

     Enables support for top-level ‘await’, ‘async for’, ‘async with’
     and async comprehensions.

     Added in version 3.8.

 -- Dati: ast.PyCF_ONLY_AST

     Generates and returns an abstract syntax tree instead of returning
     a compiled code object.

 -- Dati: ast.PyCF_OPTIMIZED_AST

     The returned AST is optimized according to the 'optimize' argument
     in *note compile(): 4b2. or *note ast.parse(): 1c2.

     Added in version 3.13.

 -- Dati: ast.PyCF_TYPE_COMMENTS

     Enables support for PEP 484(1) and PEP 526(2) style type comments
     (‘# type: <type>’, ‘# type: ignore <stuff>’).

     Added in version 3.8.

 -- Funzione: ast.compare (a, b, /, *, compare_attributes=False)

     Recursively compares two ASTs.

     'compare_attributes' affects whether AST attributes are considered
     in the comparison.  If 'compare_attributes' is ‘False’ (default),
     then attributes are ignored.  Otherwise they must all be equal.
     This option is useful to check whether the ASTs are structurally
     equal but differ in whitespace or similar details.  Attributes
     include line numbers and column offsets.

     Added in version 3.14.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0526/


File: python.info,  Node: Command-line usage<7>,  Prev: Compiler flags<2>,  Up: ast — Abstract syntax trees

5.32.1.19 Command-line usage
............................

Added in version 3.9.

The *note ast: 9. module can be executed as a script from the command
line.  It is as simple as:

     python -m ast [-m <mode>] [-a] [infile]

The following options are accepted:

 -- Option: -h, --help

     Show the help message and exit.

 -- Option: -m <mode>
 -- Option: --mode <mode>

     Specify what kind of code must be compiled, like the 'mode'
     argument in *note parse(): 1c2.

 -- Option: --no-type-comments

     Don’t parse type comments.

 -- Option: -a, --include-attributes

     Include attributes such as line numbers and column offsets.

 -- Option: -i <indent>
 -- Option: --indent <indent>

     Indentation of nodes in AST (number of spaces).

 -- Option: --feature-version <version>

     Python version in the format 3.x (for example, 3.10).  Defaults to
     the current version of the interpreter.

     Added in version 3.14.

 -- Option: -O <level>
 -- Option: --optimize <level>

     Optimization level for parser.  Defaults to no optimization.

     Added in version 3.14.

 -- Option: --show-empty

     Show empty lists and fields that are ‘None’.  Defaults to not
     showing empty objects.

     Added in version 3.14.

If ‘infile’ is specified its contents are parsed to AST and dumped to
stdout.  Otherwise, the content is read from stdin.

Vedi anche
..........

Green Tree Snakes(1), an external documentation resource, has good
details on working with Python ASTs.

ASTTokens(2) annotates Python ASTs with the positions of tokens and text
in the source code that generated them.  This is helpful for tools that
make source code transformations.

leoAst.py(3) unifies the token-based and parse-tree-based views of
python programs by inserting two-way links between tokens and ast nodes.

LibCST(4) parses code as a Concrete Syntax Tree that looks like an ast
tree and keeps all formatting details.  It’s useful for building
automated refactoring (codemod) applications and linters.

Parso(5) is a Python parser that supports error recovery and round-trip
parsing for different Python versions (in multiple Python versions).
Parso is also able to list multiple syntax errors in your Python file.

   ---------- Footnotes ----------

   (1) https://greentreesnakes.readthedocs.io/

   (2) https://asttokens.readthedocs.io/en/latest/user-guide.html

   (3) https://leo-editor.github.io/leo-editor/appendices.html#leoast-py

   (4) https://libcst.readthedocs.io/

   (5) https://parso.readthedocs.io


File: python.info,  Node: symtable — Access to the compiler’s symbol tables,  Next: token — Constants used with Python parse trees,  Prev: ast — Abstract syntax trees,  Up: Python Language Services

5.32.2 ‘symtable’ — Access to the compiler’s symbol tables
----------------------------------------------------------

'Source code:' Lib/symtable.py(1)

__________________________________________________________________

Symbol tables are generated by the compiler from AST just before
bytecode is generated.  The symbol table is responsible for calculating
the scope of every identifier in the code.  *note symtable: de. provides
an interface to examine these tables.

* Menu:

* Generating Symbol Tables::
* Examining Symbol Tables::
* Command-Line Usage: Command-Line Usage<3>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/symtable.py


File: python.info,  Node: Generating Symbol Tables,  Next: Examining Symbol Tables,  Up: symtable — Access to the compiler’s symbol tables

5.32.2.1 Generating Symbol Tables
.................................

 -- Funzione: symtable.symtable (code, filename, compile_type)

     Return the toplevel *note SymbolTable: 4bd4. for the Python source
     'code'.  'filename' is the name of the file containing the code.
     'compile_type' is like the 'mode' argument to *note compile(): 4b2.


File: python.info,  Node: Examining Symbol Tables,  Next: Command-Line Usage<3>,  Prev: Generating Symbol Tables,  Up: symtable — Access to the compiler’s symbol tables

5.32.2.2 Examining Symbol Tables
................................

 -- Classe: symtable.SymbolTableType

     An enumeration indicating the type of a *note SymbolTable: 4bd4.
     object.

      -- Attributo: MODULE = "module"

          Used for the symbol table of a module.

      -- Attributo: FUNCTION = "function"

          Used for the symbol table of a function.

      -- Attributo: CLASS = "class"

          Used for the symbol table of a class.

     The following members refer to different flavors of *note
     annotation scopes: 4ac.

      -- Attributo: ANNOTATION = "annotation"

          Used for annotations if ‘from __future__ import annotations’
          is active.

      -- Attributo: TYPE_ALIAS = "type alias"

          Used for the symbol table of *note type: 66d. constructions.

      -- Attributo: TYPE_PARAMETERS = "type parameters"

          Used for the symbol table of *note generic functions: 683. or
          *note generic classes: 682.

      -- Attributo: TYPE_VARIABLE = "type variable"

          Used for the symbol table of the bound, the constraint tuple
          or the default value of a single type variable in the formal
          sense, i.e., a TypeVar, a TypeVarTuple or a ParamSpec object
          (the latter two do not support a bound or a constraint tuple).

     Added in version 3.13.

 -- Classe: symtable.SymbolTable

     A namespace table for a block.  The constructor is not public.

      -- Metodo: get_type ()

          Return the type of the symbol table.  Possible values are
          members of the *note SymbolTableType: 193a. enumeration.

          Cambiato nella versione 3.12: Added ‘'annotation'’, ‘'TypeVar
          bound'’, ‘'type alias'’, and ‘'type parameter'’ as possible
          return values.

          Cambiato nella versione 3.13: Return values are members of the
          *note SymbolTableType: 193a. enumeration.

          The exact values of the returned string may change in the
          future, and thus, it is recommended to use *note
          SymbolTableType: 193a. members instead of hard-coded strings.

      -- Metodo: get_id ()

          Return the table’s identifier.

      -- Metodo: get_name ()

          Return the table’s name.  This is the name of the class if the
          table is for a class, the name of the function if the table is
          for a function, or ‘'top'’ if the table is global (*note
          get_type(): 193b. returns ‘'module'’).  For type parameter
          scopes (which are used for generic classes, functions, and
          type aliases), it is the name of the underlying class,
          function, or type alias.  For type alias scopes, it is the
          name of the type alias.  For *note TypeVar: 487. bound scopes,
          it is the name of the ‘TypeVar’.

      -- Metodo: get_lineno ()

          Return the number of the first line in the block this table
          represents.

      -- Metodo: is_optimized ()

          Return ‘True’ if the locals in this table can be optimized.

      -- Metodo: is_nested ()

          Return ‘True’ if the block is a nested class or function.

      -- Metodo: has_children ()

          Return ‘True’ if the block has nested namespaces within it.
          These can be obtained with *note get_children(): 4be3.

      -- Metodo: get_identifiers ()

          Return a view object containing the names of symbols in the
          table.  See the *note documentation of view objects: 25f4.

      -- Metodo: lookup (name)

          Lookup 'name' in the table and return a *note Symbol: 289.
          instance.

      -- Metodo: get_symbols ()

          Return a list of *note Symbol: 289. instances for names in the
          table.

      -- Metodo: get_children ()

          Return a list of the nested symbol tables.

 -- Classe: symtable.Function

     A namespace for a function or method.  This class inherits from
     *note SymbolTable: 4bd4.

      -- Metodo: get_parameters ()

          Return a tuple containing names of parameters to this
          function.

      -- Metodo: get_locals ()

          Return a tuple containing names of locals in this function.

      -- Metodo: get_globals ()

          Return a tuple containing names of globals in this function.

      -- Metodo: get_nonlocals ()

          Return a tuple containing names of explicitly declared
          nonlocals in this function.

      -- Metodo: get_frees ()

          Return a tuple containing names of *note free (closure)
          variables: 187b. in this function.

 -- Classe: symtable.Class

     A namespace of a class.  This class inherits from *note
     SymbolTable: 4bd4.

      -- Metodo: get_methods ()

          Return a tuple containing the names of method-like functions
          declared in the class.

          Here, the term “method” designates 'any' function defined in
          the class body via *note def: 1661. or *note async def: 7ee.

          Functions defined in a deeper scope (e.g., in an inner class)
          are not picked up by *note get_methods(): 31d.

          For example:

               >>> import symtable
               >>> st = symtable.symtable('''
               ... def outer(): pass
               ...
               ... class A:
               ...    def f():
               ...        def w(): pass
               ...
               ...    def g(self): pass
               ...
               ...    @classmethod
               ...    async def h(cls): pass
               ...
               ...    global outer
               ...    def outer(self): pass
               ... ''', 'test', 'exec')
               >>> class_A = st.get_children()[2]
               >>> class_A.get_methods()
               ('f', 'g', 'h')

          Although ‘A().f()’ raises *note TypeError: 198. at runtime,
          ‘A.f’ is still considered as a method-like function.

          Deprecated since version 3.14, will be removed in version
          3.16.

 -- Classe: symtable.Symbol

     An entry in a *note SymbolTable: 4bd4. corresponding to an
     identifier in the source.  The constructor is not public.

      -- Metodo: get_name ()

          Return the symbol’s name.

      -- Metodo: is_referenced ()

          Return ‘True’ if the symbol is used in its block.

      -- Metodo: is_imported ()

          Return ‘True’ if the symbol is created from an import
          statement.

      -- Metodo: is_parameter ()

          Return ‘True’ if the symbol is a parameter.

      -- Metodo: is_type_parameter ()

          Return ‘True’ if the symbol is a type parameter.

          Added in version 3.14.

      -- Metodo: is_global ()

          Return ‘True’ if the symbol is global.

      -- Metodo: is_nonlocal ()

          Return ‘True’ if the symbol is nonlocal.

      -- Metodo: is_declared_global ()

          Return ‘True’ if the symbol is declared global with a global
          statement.

      -- Metodo: is_local ()

          Return ‘True’ if the symbol is local to its block.

      -- Metodo: is_annotated ()

          Return ‘True’ if the symbol is annotated.

          Added in version 3.6.

      -- Metodo: is_free ()

          Return ‘True’ if the symbol is referenced in its block, but
          not assigned to.

      -- Metodo: is_free_class ()

          Return 'True' if a class-scoped symbol is free from the
          perspective of a method.

          Consider the following example:

               def f():
                   x = 1  # function-scoped
                   class C:
                       x = 2  # class-scoped
                       def method(self):
                           return x

          In this example, the class-scoped symbol ‘x’ is considered to
          be free from the perspective of ‘C.method’, thereby allowing
          the latter to return '1' at runtime and not '2'.

          Added in version 3.14.

      -- Metodo: is_assigned ()

          Return ‘True’ if the symbol is assigned to in its block.

      -- Metodo: is_comp_iter ()

          Return ‘True’ if the symbol is a comprehension iteration
          variable.

          Added in version 3.14.

      -- Metodo: is_comp_cell ()

          Return ‘True’ if the symbol is a cell in an inlined
          comprehension.

          Added in version 3.14.

      -- Metodo: is_namespace ()

          Return ‘True’ if name binding introduces new namespace.

          If the name is used as the target of a function or class
          statement, this will be true.

          For example:

               >>> table = symtable.symtable("def some_func(): pass", "string", "exec")
               >>> table.lookup("some_func").is_namespace()
               True

          Note that a single name can be bound to multiple objects.  If
          the result is ‘True’, the name may also be bound to other
          objects, like an int or list, that does not introduce a new
          namespace.

      -- Metodo: get_namespaces ()

          Return a list of namespaces bound to this name.

      -- Metodo: get_namespace ()

          Return the namespace bound to this name.  If more than one or
          no namespace is bound to this name, a *note ValueError: 2ec.
          is raised.


File: python.info,  Node: Command-Line Usage<3>,  Prev: Examining Symbol Tables,  Up: symtable — Access to the compiler’s symbol tables

5.32.2.3 Command-Line Usage
...........................

Added in version 3.13.

The *note symtable: de. module can be executed as a script from the
command line.

     python -m symtable [infile...]

Symbol tables are generated for the specified Python source files and
dumped to stdout.  If no input file is specified, the content is read
from stdin.


File: python.info,  Node: token — Constants used with Python parse trees,  Next: keyword — Testing for Python keywords,  Prev: symtable — Access to the compiler’s symbol tables,  Up: Python Language Services

5.32.3 ‘token’ — Constants used with Python parse trees
-------------------------------------------------------

'Source code:' Lib/token.py(1)

__________________________________________________________________

This module provides constants which represent the numeric values of
leaf nodes of the parse tree (terminal tokens).  Refer to the file
‘Grammar/Tokens’ in the Python distribution for the definitions of the
names in the context of the language grammar.  The specific numeric
values which the names map to may change between Python versions.

The module also provides a mapping from numeric codes to names and some
functions.  The functions mirror definitions in the Python C header
files.

Note that a token’s value may depend on tokenizer options.  For example,
a ‘"+"’ token may be reported as either *note PLUS: 4bff. or *note OP:
2273, or a ‘"match"’ token may be either *note NAME: 22a2. or *note
SOFT_KEYWORD: 4c00.

 -- Dati: token.tok_name

     Dictionary mapping the numeric values of the constants defined in
     this module back to name strings, allowing more human-readable
     representation of parse trees to be generated.

 -- Funzione: token.ISTERMINAL (x)

     Return ‘True’ for terminal token values.

 -- Funzione: token.ISNONTERMINAL (x)

     Return ‘True’ for non-terminal token values.

 -- Funzione: token.ISEOF (x)

     Return ‘True’ if 'x' is the marker indicating the end of input.

The token constants are:

 -- Dati: token.NAME

     Token value that indicates an *note identifier: 2289.  Note that
     keywords are also initially tokenized as ‘NAME’ tokens.

 -- Dati: token.NUMBER

     Token value that indicates a *note numeric literal: 228a.

 -- Dati: token.STRING

     Token value that indicates a *note string or byte literal: 2288,
     excluding *note formatted string literals: 19a.  The token string
     is not interpreted: it includes the surrounding quotation marks and
     the prefix (if given); backslashes are included literally, without
     processing escape sequences.

 -- Dati: token.OP

     A generic token value that indicates an *note operator: 2275. or
     *note delimiter: 2274.

     'Dettaglio dell’implementazione di CPython:' This value is only
     reported by the *note tokenize: 101. module.  Internally, the
     tokenizer uses *note exact token types: 2307. instead.

 -- Dati: token.COMMENT

     Token value used to indicate a comment.  The parser ignores
     ‘COMMENT’ tokens.

 -- Dati: token.NEWLINE

     Token value that indicates the end of a *note logical line: 228e.

 -- Dati: token.NL

     Token value used to indicate a non-terminating newline.  ‘NL’
     tokens are generated when a logical line of code is continued over
     multiple physical lines.  The parser ignores ‘NL’ tokens.

 -- Dati: token.INDENT

     Token value used at the beginning of a *note logical line: 228e. to
     indicate the start of an *note indented block: 2285.

 -- Dati: token.DEDENT

     Token value used at the beginning of a *note logical line: 228e. to
     indicate the end of an *note indented block: 2285.

 -- Dati: token.FSTRING_START

     Token value used to indicate the beginning of an *note f-string
     literal: 19a.

     'Dettaglio dell’implementazione di CPython:' The token string
     includes the prefix and the opening quote(s), but none of the
     contents of the literal.

 -- Dati: token.FSTRING_MIDDLE

     Token value used for literal text inside an *note f-string literal:
     19a, including format specifications.

     'Dettaglio dell’implementazione di CPython:' Replacement fields
     (that is, the non-literal parts of f-strings) use the same tokens
     as other expressions, and are delimited by *note LBRACE: 4c07,
     *note RBRACE: 4c08, *note EXCLAMATION: 4c09. and *note COLON: 4c0a.
     tokens.

 -- Dati: token.FSTRING_END

     Token value used to indicate the end of a *note f-string: 19a.

     'Dettaglio dell’implementazione di CPython:' The token string
     contains the closing quote(s).

 -- Dati: token.TSTRING_START

     Token value used to indicate the beginning of a template string
     literal.

     'Dettaglio dell’implementazione di CPython:' The token string
     includes the prefix and the opening quote(s), but none of the
     contents of the literal.

     Added in version 3.14.

 -- Dati: token.TSTRING_MIDDLE

     Token value used for literal text inside a template string literal
     including format specifications.

     'Dettaglio dell’implementazione di CPython:' Replacement fields
     (that is, the non-literal parts of t-strings) use the same tokens
     as other expressions, and are delimited by *note LBRACE: 4c07,
     *note RBRACE: 4c08, *note EXCLAMATION: 4c09. and *note COLON: 4c0a.
     tokens.

     Added in version 3.14.

 -- Dati: token.TSTRING_END

     Token value used to indicate the end of a template string literal.

     'Dettaglio dell’implementazione di CPython:' The token string
     contains the closing quote(s).

     Added in version 3.14.

 -- Dati: token.ENDMARKER

     Token value that indicates the end of input.  Used in *note
     top-level grammar rules: 2576.

 -- Dati: token.ENCODING

     Token value that indicates the encoding used to decode the source
     bytes into text.  The first token returned by *note
     tokenize.tokenize(): 701. will always be an ‘ENCODING’ token.

     'Dettaglio dell’implementazione di CPython:' This token type isn’t
     used by the C tokenizer but is needed for the *note tokenize: 101.
     module.

The following token types are not produced by the *note tokenize: 101.
module, and are defined for special uses in the tokenizer or parser:

 -- Dati: token.TYPE_IGNORE

     Token value indicating that a ‘type: ignore’ comment was
     recognized.  Such tokens are produced instead of regular *note
     COMMENT: 4c05. tokens only with the *note PyCF_TYPE_COMMENTS: 4bb8.
     flag.

 -- Dati: token.TYPE_COMMENT

     Token value indicating that a type comment was recognized.  Such
     tokens are produced instead of regular *note COMMENT: 4c05. tokens
     only with the *note PyCF_TYPE_COMMENTS: 4bb8. flag.

 -- Dati: token.SOFT_KEYWORD

     Token value indicating a *note soft keyword: a0f.

     The tokenizer never produces this value.  To check for a soft
     keyword, pass a *note NAME: 22a2. token’s string to *note
     keyword.issoftkeyword(): 4c11.

 -- Dati: token.ERRORTOKEN

     Token value used to indicate wrong input.

     The *note tokenize: 101. module generally indicates errors by
     raising exceptions instead of emitting this token.  It can also
     emit tokens such as *note OP: 2273. or *note NAME: 22a2. with
     strings that are later rejected by the parser.
The remaining tokens represent specific *note operators: 2275. and *note
delimiters: 2274.  (The *note tokenize: 101. module reports these as
*note OP: 2273.; see ‘exact_type’ in the *note tokenize: 101.
documentation for details.)

Token                                                  Value
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
 -- Dati: token.LPAR                                   ‘"("’
                                                       
                                                       
 -- Dati: token.RPAR                                   ‘")"’
                                                       
                                                       
 -- Dati: token.LSQB                                   ‘"["’
                                                       
                                                       
 -- Dati: token.RSQB                                   ‘"]"’
                                                       
                                                       
 -- Dati: token.COLON                                  ‘":"’
                                                       
                                                       
 -- Dati: token.COMMA                                  ‘","’
                                                       
                                                       
 -- Dati: token.SEMI                                   ‘";"’
                                                       
                                                       
 -- Dati: token.PLUS                                   ‘"+"’
                                                       
                                                       
 -- Dati: token.MINUS                                  ‘"-"’
                                                       
                                                       
 -- Dati: token.STAR                                   ‘"*"’
                                                       
                                                       
 -- Dati: token.SLASH                                  ‘"/"’
                                                       
                                                       
 -- Dati: token.VBAR                                   ‘"|"’
                                                       
                                                       
 -- Dati: token.AMPER                                  ‘"&"’
                                                       
                                                       
 -- Dati: token.LESS                                   ‘"<"’
                                                       
                                                       
 -- Dati: token.GREATER                                ‘">"’
                                                       
                                                       
 -- Dati: token.EQUAL                                  ‘"="’
                                                       
                                                       
 -- Dati: token.DOT                                    ‘"."’
                                                       
                                                       
 -- Dati: token.PERCENT                                ‘"%"’
                                                       
                                                       
 -- Dati: token.LBRACE                                 ‘"{"’
                                                       
                                                       
 -- Dati: token.RBRACE                                 ‘"}"’
                                                       
                                                       
 -- Dati: token.EQEQUAL                                ‘"=="’
                                                       
                                                       
 -- Dati: token.NOTEQUAL                               ‘"!="’
                                                       
                                                       
 -- Dati: token.LESSEQUAL                              ‘"<="’
                                                       
                                                       
 -- Dati: token.GREATEREQUAL                           ‘">="’
                                                       
                                                       
 -- Dati: token.TILDE                                  ‘"~"’
                                                       
                                                       
 -- Dati: token.CIRCUMFLEX                             ‘"^"’
                                                       
                                                       
 -- Dati: token.LEFTSHIFT                              ‘"<<"’
                                                       
                                                       
 -- Dati: token.RIGHTSHIFT                             ‘">>"’
                                                       
                                                       
 -- Dati: token.DOUBLESTAR                             ‘"**"’
                                                       
                                                       
 -- Dati: token.PLUSEQUAL                              ‘"+="’
                                                       
                                                       
 -- Dati: token.MINEQUAL                               ‘"-="’
                                                       
                                                       
 -- Dati: token.STAREQUAL                              ‘"*="’
                                                       
                                                       
 -- Dati: token.SLASHEQUAL                             ‘"/="’
                                                       
                                                       
 -- Dati: token.PERCENTEQUAL                           ‘"%="’
                                                       
                                                       
 -- Dati: token.AMPEREQUAL                             ‘"&="’
                                                       
                                                       
 -- Dati: token.VBAREQUAL                              ‘"|="’
                                                       
                                                       
 -- Dati: token.CIRCUMFLEXEQUAL                        ‘"^="’
                                                       
                                                       
 -- Dati: token.LEFTSHIFTEQUAL                         ‘"<<="’
                                                       
                                                       
 -- Dati: token.RIGHTSHIFTEQUAL                        ‘">>="’
                                                       
                                                       
 -- Dati: token.DOUBLESTAREQUAL                        ‘"**="’
                                                       
                                                       
 -- Dati: token.DOUBLESLASH                            ‘"//"’
                                                       
                                                       
 -- Dati: token.DOUBLESLASHEQUAL                       ‘"//="’
                                                       
                                                       
 -- Dati: token.AT                                     ‘"@"’
                                                       
                                                       
 -- Dati: token.ATEQUAL                                ‘"@="’
                                                       
                                                       
 -- Dati: token.RARROW                                 ‘"->"’
                                                       
                                                       
 -- Dati: token.ELLIPSIS                               ‘"..."’
                                                       
                                                       
 -- Dati: token.COLONEQUAL                             ‘":="’
                                                       
                                                       
 -- Dati: token.EXCLAMATION                            ‘"!"’
                                                       

The following non-token constants are provided:

 -- Dati: token.N_TOKENS

     The number of token types defined in this module.

 -- Dati: token.EXACT_TOKEN_TYPES

     A dictionary mapping the string representation of a token to its
     numeric code.

     Added in version 3.8.

Cambiato nella versione 3.5: Added ‘AWAIT’ and ‘ASYNC’ tokens.

Cambiato nella versione 3.7: Added *note COMMENT: 4c05, *note NL: 4c06.
and *note ENCODING: 4c0e. tokens.

Cambiato nella versione 3.7: Removed ‘AWAIT’ and ‘ASYNC’ tokens.
«async» and «await» are now tokenized as *note NAME: 22a2. tokens.

Cambiato nella versione 3.8: Added *note TYPE_COMMENT: 4c10, *note
TYPE_IGNORE: 4c0f, *note COLONEQUAL: 4c3d.  Added ‘AWAIT’ and ‘ASYNC’
tokens back (they’re needed to support parsing older Python versions for
*note ast.parse(): 1c2. with ‘feature_version’ set to 6 or lower).

Cambiato nella versione 3.12: Added *note EXCLAMATION: 4c09.

Cambiato nella versione 3.13: Removed ‘AWAIT’ and ‘ASYNC’ tokens again.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/token.py


File: python.info,  Node: keyword — Testing for Python keywords,  Next: tokenize — Tokenizer for Python source,  Prev: token — Constants used with Python parse trees,  Up: Python Language Services

5.32.4 ‘keyword’ — Testing for Python keywords
----------------------------------------------

'Source code:' Lib/keyword.py(1)

__________________________________________________________________

This module allows a Python program to determine if a string is a *note
keyword: 2272. or *note soft keyword: a0f.

 -- Funzione: keyword.iskeyword (s)

     Return ‘True’ if 's' is a Python *note keyword: 2272.

 -- Dati: keyword.kwlist

     Sequence containing all the *note keywords: 2272. defined for the
     interpreter.  If any keywords are defined to only be active when
     particular *note __future__: 0. statements are in effect, these
     will be included as well.

 -- Funzione: keyword.issoftkeyword (s)

     Return ‘True’ if 's' is a Python *note soft keyword: a0f.

     Added in version 3.9.

 -- Dati: keyword.softkwlist

     Sequence containing all the *note soft keywords: a0f. defined for
     the interpreter.  If any soft keywords are defined to only be
     active when particular *note __future__: 0. statements are in
     effect, these will be included as well.

     Added in version 3.9.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/keyword.py


File: python.info,  Node: tokenize — Tokenizer for Python source,  Next: tabnanny — Detection of ambiguous indentation,  Prev: keyword — Testing for Python keywords,  Up: Python Language Services

5.32.5 ‘tokenize’ — Tokenizer for Python source
-----------------------------------------------

'Source code:' Lib/tokenize.py(1)

__________________________________________________________________

The *note tokenize: 101. module provides a lexical scanner for Python
source code, implemented in Python.  The scanner in this module returns
comments as tokens as well, making it useful for implementing
«pretty-printers», including colorizers for on-screen displays.

To simplify token stream handling, all *note operator: 2275. and *note
delimiter: 2274. tokens and *note Ellipsis: 2311. are returned using the
generic *note OP: 2273. token type.  The exact type can be determined by
checking the ‘exact_type’ property on the *note named tuple: 85f.
returned from *note tokenize.tokenize(): 701.

     Avvertimento: Note that the functions in this module are only
     designed to parse syntactically valid Python code (code that does
     not raise when parsed using *note ast.parse(): 1c2.).  The behavior
     of the functions in this module is 'undefined' when providing
     invalid Python code and it can change at any point.

* Menu:

* Tokenizing Input::
* Command-Line Usage: Command-Line Usage<4>.
* Examples: Examples<36>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/tokenize.py


File: python.info,  Node: Tokenizing Input,  Next: Command-Line Usage<4>,  Up: tokenize — Tokenizer for Python source

5.32.5.1 Tokenizing Input
.........................

The primary entry point is a *note generator: 1263.:

 -- Funzione: tokenize.tokenize (readline)

     The *note tokenize(): 701. generator requires one argument,
     'readline', which must be a callable object which provides the same
     interface as the *note io.IOBase.readline(): 1531. method of file
     objects.  Each call to the function should return one line of input
     as bytes.

     The generator produces 5-tuples with these members: the token type;
     the token string; a 2-tuple ‘(srow, scol)’ of ints specifying the
     row and column where the token begins in the source; a 2-tuple
     ‘(erow, ecol)’ of ints specifying the row and column where the
     token ends in the source; and the line on which the token was
     found.  The line passed (the last tuple item) is the 'physical'
     line.  The 5 tuple is returned as a *note named tuple: 85f. with
     the field names: ‘type string start end line’.

     The returned *note named tuple: 85f. has an additional property
     named ‘exact_type’ that contains the exact operator type for *note
     OP: 2273. tokens.  For all other token types ‘exact_type’ equals
     the named tuple ‘type’ field.

     Cambiato nella versione 3.1: Added support for named tuples.

     Cambiato nella versione 3.3: Added support for ‘exact_type’.

     *note tokenize(): 701. determines the source encoding of the file
     by looking for a UTF-8 BOM or encoding cookie, according to PEP
     263(1).

 -- Funzione: tokenize.generate_tokens (readline)

     Tokenize a source reading unicode strings instead of bytes.

     Like *note tokenize(): 701, the 'readline' argument is a callable
     returning a single line of input.  However, *note
     generate_tokens(): 702. expects 'readline' to return a str object
     rather than bytes.

     The result is an iterator yielding named tuples, exactly like *note
     tokenize(): 701.  It does not yield an *note ENCODING: 4c0e. token.

All constants from the *note token: 100. module are also exported from
*note tokenize: 101.

Another function is provided to reverse the tokenization process.  This
is useful for creating tools that tokenize a script, modify the token
stream, and write back the modified script.

 -- Funzione: tokenize.untokenize (iterable)

     Converts tokens back into Python source code.  The 'iterable' must
     return sequences with at least two elements, the token type and the
     token string.  Any additional sequence elements are ignored.

     The result is guaranteed to tokenize back to match the input so
     that the conversion is lossless and round-trips are assured.  The
     guarantee applies only to the token type and token string as the
     spacing between tokens (column positions) may change.

     It returns bytes, encoded using the *note ENCODING: 4c0e. token,
     which is the first token sequence output by *note tokenize(): 701.
     If there is no encoding token in the input, it returns a str
     instead.

*note tokenize(): 701. needs to detect the encoding of source files it
tokenizes.  The function it uses to do this is available:

 -- Funzione: tokenize.detect_encoding (readline)

     The *note detect_encoding(): 17a0. function is used to detect the
     encoding that should be used to decode a Python source file.  It
     requires one argument, readline, in the same way as the *note
     tokenize(): 701. generator.

     It will call readline a maximum of twice, and return the encoding
     used (as a string) and a list of any lines (not decoded from bytes)
     it has read in.

     It detects the encoding from the presence of a UTF-8 BOM or an
     encoding cookie as specified in PEP 263(2).  If both a BOM and a
     cookie are present, but disagree, a *note SyntaxError: 18e. will be
     raised.  Note that if the BOM is found, ‘'utf-8-sig'’ will be
     returned as an encoding.

     If no encoding is specified, then the default of ‘'utf-8'’ will be
     returned.

     Use *note open(): 2cc5. to open Python source files: it uses *note
     detect_encoding(): 17a0. to detect the file encoding.

 -- Funzione: tokenize.open (filename)

     Open a file in read only mode using the encoding detected by *note
     detect_encoding(): 17a0.

     Added in version 3.2.

 -- Eccezione: tokenize.TokenError

     Raised when either a docstring or expression that may be split over
     several lines is not completed anywhere in the file, for example:

          """Beginning of
          docstring

     or:

          [1,
           2,
           3

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0263/

   (2) https://peps.python.org/pep-0263/


File: python.info,  Node: Command-Line Usage<4>,  Next: Examples<36>,  Prev: Tokenizing Input,  Up: tokenize — Tokenizer for Python source

5.32.5.2 Command-Line Usage
...........................

Added in version 3.3.

The *note tokenize: 101. module can be executed as a script from the
command line.  It is as simple as:

     python -m tokenize [-e] [filename.py]

The following options are accepted:

 -- Option: -h, --help

     show this help message and exit

 -- Option: -e, --exact

     display token names using the exact type

If ‘filename.py’ is specified its contents are tokenized to stdout.
Otherwise, tokenization is performed on stdin.


File: python.info,  Node: Examples<36>,  Prev: Command-Line Usage<4>,  Up: tokenize — Tokenizer for Python source

5.32.5.3 Examples
.................

Example of a script rewriter that transforms float literals into Decimal
objects:

     from tokenize import tokenize, untokenize, NUMBER, STRING, NAME, OP
     from io import BytesIO

     def decistmt(s):
         """Substitute Decimals for floats in a string of statements.

         >>> from decimal import Decimal
         >>> s = 'print(+21.3e-5*-.1234/81.7)'
         >>> decistmt(s)
         "print (+Decimal ('21.3e-5')*-Decimal ('.1234')/Decimal ('81.7'))"

         The format of the exponent is inherited from the platform C library.
         Known cases are "e-007" (Windows) and "e-07" (not Windows).  Since
         we're only showing 12 digits, and the 13th isn't close to 5, the
         rest of the output should be platform-independent.

         >>> exec(s)  #doctest: +ELLIPSIS
         -3.21716034272e-0...7

         Output from calculations with Decimal should be identical across all
         platforms.

         >>> exec(decistmt(s))
         -3.217160342717258261933904529E-7
         """
         result = []
         g = tokenize(BytesIO(s.encode('utf-8')).readline)  # tokenize the string
         for toknum, tokval, _, _, _ in g:
             if toknum == NUMBER and '.' in tokval:  # replace NUMBER tokens
                 result.extend([
                     (NAME, 'Decimal'),
                     (OP, '('),
                     (STRING, repr(tokval)),
                     (OP, ')')
                 ])
             else:
                 result.append((toknum, tokval))
         return untokenize(result).decode('utf-8')

Example of tokenizing from the command line.  The script:

     def say_hello():
         print("Hello, World!")

     say_hello()

will be tokenized to the following output where the first column is the
range of the line/column coordinates where the token is found, the
second column is the name of the token, and the final column is the
value of the token (if any)

     $ python -m tokenize hello.py
     0,0-0,0:            ENCODING       'utf-8'
     1,0-1,3:            NAME           'def'
     1,4-1,13:           NAME           'say_hello'
     1,13-1,14:          OP             '('
     1,14-1,15:          OP             ')'
     1,15-1,16:          OP             ':'
     1,16-1,17:          NEWLINE        '\n'
     2,0-2,4:            INDENT         '    '
     2,4-2,9:            NAME           'print'
     2,9-2,10:           OP             '('
     2,10-2,25:          STRING         '"Hello, World!"'
     2,25-2,26:          OP             ')'
     2,26-2,27:          NEWLINE        '\n'
     3,0-3,1:            NL             '\n'
     4,0-4,0:            DEDENT         ''
     4,0-4,9:            NAME           'say_hello'
     4,9-4,10:           OP             '('
     4,10-4,11:          OP             ')'
     4,11-4,12:          NEWLINE        '\n'
     5,0-5,0:            ENDMARKER      ''

The exact token type names can be displayed using the *note -e: 4c4c.
option:

     $ python -m tokenize -e hello.py
     0,0-0,0:            ENCODING       'utf-8'
     1,0-1,3:            NAME           'def'
     1,4-1,13:           NAME           'say_hello'
     1,13-1,14:          LPAR           '('
     1,14-1,15:          RPAR           ')'
     1,15-1,16:          COLON          ':'
     1,16-1,17:          NEWLINE        '\n'
     2,0-2,4:            INDENT         '    '
     2,4-2,9:            NAME           'print'
     2,9-2,10:           LPAR           '('
     2,10-2,25:          STRING         '"Hello, World!"'
     2,25-2,26:          RPAR           ')'
     2,26-2,27:          NEWLINE        '\n'
     3,0-3,1:            NL             '\n'
     4,0-4,0:            DEDENT         ''
     4,0-4,9:            NAME           'say_hello'
     4,9-4,10:           LPAR           '('
     4,10-4,11:          RPAR           ')'
     4,11-4,12:          NEWLINE        '\n'
     5,0-5,0:            ENDMARKER      ''

Example of tokenizing a file programmatically, reading unicode strings
instead of bytes with *note generate_tokens(): 702.:

     import tokenize

     with tokenize.open('hello.py') as f:
         tokens = tokenize.generate_tokens(f.readline)
         for token in tokens:
             print(token)

Or reading bytes directly with *note tokenize(): 701.:

     import tokenize

     with open('hello.py', 'rb') as f:
         tokens = tokenize.tokenize(f.readline)
         for token in tokens:
             print(token)


File: python.info,  Node: tabnanny — Detection of ambiguous indentation,  Next: pyclbr — Python module browser support,  Prev: tokenize — Tokenizer for Python source,  Up: Python Language Services

5.32.6 ‘tabnanny’ — Detection of ambiguous indentation
------------------------------------------------------

'Source code:' Lib/tabnanny.py(1)

__________________________________________________________________

For the time being this module is intended to be called as a script.
However it is possible to import it into an IDE and use the function
*note check(): 4c52. described below.

     Nota: The API provided by this module is likely to change in future
     releases; such changes may not be backward compatible.

 -- Funzione: tabnanny.check (file_or_dir)

     If 'file_or_dir' is a directory and not a symbolic link, then
     recursively descend the directory tree named by 'file_or_dir',
     checking all ‘.py’ files along the way.  If 'file_or_dir' is an
     ordinary Python source file, it is checked for whitespace related
     problems.  The diagnostic messages are written to standard output
     using the *note print(): 1177. function.

 -- Dati: tabnanny.verbose

     Flag indicating whether to print verbose messages.  This is
     incremented by the ‘-v’ option if called as a script.

 -- Dati: tabnanny.filename_only

     Flag indicating whether to print only the filenames of files
     containing whitespace related problems.  This is set to true by the
     ‘-q’ option if called as a script.

 -- Eccezione: tabnanny.NannyNag

     Raised by *note process_tokens(): 4c56. if detecting an ambiguous
     indent.  Captured and handled in *note check(): 4c52.

 -- Funzione: tabnanny.process_tokens (tokens)

     This function is used by *note check(): 4c52. to process tokens
     generated by the *note tokenize: 101. module.

Vedi anche
..........

Module *note tokenize: 101.

     Lexical scanner for Python source code.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/tabnanny.py


File: python.info,  Node: pyclbr — Python module browser support,  Next: py_compile — Compile Python source files,  Prev: tabnanny — Detection of ambiguous indentation,  Up: Python Language Services

5.32.7 ‘pyclbr’ — Python module browser support
-----------------------------------------------

'Source code:' Lib/pyclbr.py(1)

__________________________________________________________________

The *note pyclbr: b9. module provides limited information about the
functions, classes, and methods defined in a Python-coded module.  The
information is sufficient to implement a module browser.  The
information is extracted from the Python source code rather than by
importing the module, so this module is safe to use with untrusted code.
This restriction makes it impossible to use this module with modules not
implemented in Python, including all standard and optional extension
modules.

 -- Funzione: pyclbr.readmodule (module, path=None)

     Return a dictionary mapping module-level class names to class
     descriptors.  If possible, descriptors for imported base classes
     are included.  Parameter 'module' is a string with the name of the
     module to read; it may be the name of a module within a package.
     If given, 'path' is a sequence of directory paths prepended to
     ‘sys.path’, which is used to locate the module source code.

     This function is the original interface and is only kept for back
     compatibility.  It returns a filtered version of the following.

 -- Funzione: pyclbr.readmodule_ex (module, path=None)

     Return a dictionary-based tree containing a function or class
     descriptors for each function and class defined in the module with
     a ‘def’ or ‘class’ statement.  The returned dictionary maps
     module-level function and class names to their descriptors.  Nested
     objects are entered into the children dictionary of their parent.
     As with readmodule, 'module' names the module to be read and 'path'
     is prepended to sys.path.  If the module being read is a package,
     the returned dictionary has a key ‘'__path__'’ whose value is a
     list containing the package search path.

Added in version 3.7: Descriptors for nested definitions.  They are
accessed through the new children attribute.  Each has a new parent
attribute.

The descriptors returned by these functions are instances of Function
and Class classes.  Users are not expected to create instances of these
classes.

* Menu:

* Function Objects::
* Class Objects::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/pyclbr.py


File: python.info,  Node: Function Objects,  Next: Class Objects,  Up: pyclbr — Python module browser support

5.32.7.1 Function Objects
.........................

 -- Classe: pyclbr.Function

     Class ‘Function’ instances describe functions defined by def
     statements.  They have the following attributes:

      -- Attributo: file

          Name of the file in which the function is defined.

      -- Attributo: module

          The name of the module defining the function described.

      -- Attributo: name

          The name of the function.

      -- Attributo: lineno

          The line number in the file where the definition starts.

      -- Attributo: parent

          For top-level functions, ‘None’.  For nested functions, the
          parent.

          Added in version 3.7.

      -- Attributo: children

          A *note dictionary: 183. mapping names to descriptors for
          nested functions and classes.

          Added in version 3.7.

      -- Attributo: is_async

          ‘True’ for functions that are defined with the *note async:
          7ee. prefix, ‘False’ otherwise.

          Added in version 3.10.


File: python.info,  Node: Class Objects,  Prev: Function Objects,  Up: pyclbr — Python module browser support

5.32.7.2 Class Objects
......................

 -- Classe: pyclbr.Class

     Class ‘Class’ instances describe classes defined by class
     statements.  They have the same attributes as *note Functions:
     4c5c. and two more.

      -- Attributo: file

          Name of the file in which the class is defined.

      -- Attributo: module

          The name of the module defining the class described.

      -- Attributo: name

          The name of the class.

      -- Attributo: lineno

          The line number in the file where the definition starts.

      -- Attributo: parent

          For top-level classes, ‘None’.  For nested classes, the
          parent.

          Added in version 3.7.

      -- Attributo: children

          A dictionary mapping names to descriptors for nested functions
          and classes.

          Added in version 3.7.

      -- Attributo: super

          A list of ‘Class’ objects which describe the immediate base
          classes of the class being described.  Classes which are named
          as superclasses but which are not discoverable by *note
          readmodule_ex(): a2f. are listed as a string with the class
          name instead of as ‘Class’ objects.

      -- Attributo: methods

          A *note dictionary: 183. mapping method names to line numbers.
          This can be derived from the newer *note children: 4c6c.
          dictionary, but remains for back-compatibility.


File: python.info,  Node: py_compile — Compile Python source files,  Next: compileall — Byte-compile Python libraries,  Prev: pyclbr — Python module browser support,  Up: Python Language Services

5.32.8 ‘py_compile’ — Compile Python source files
-------------------------------------------------

'Source code:' Lib/py_compile.py(1)

__________________________________________________________________

The *note py_compile: b8. module provides a function to generate a
byte-code file from a source file, and another function used when the
module source file is invoked as a script.

Though not often needed, this function can be useful when installing
modules for shared use, especially if some of the users may not have
permission to write the byte-code cache files in the directory
containing the source code.

 -- Eccezione: py_compile.PyCompileError

     Exception raised when an error occurs while attempting to compile
     the file.

 -- Funzione: py_compile.compile (file, cfile=None, dfile=None,
          doraise=False, optimize=-1,
          invalidation_mode=PycInvalidationMode.TIMESTAMP, quiet=0)

     Compile a source file to byte-code and write out the byte-code
     cache file.  The source code is loaded from the file named 'file'.
     The byte-code is written to 'cfile', which defaults to the PEP
     3147(2)/ PEP 488(3) path, ending in ‘.pyc’.  For example, if 'file'
     is ‘/foo/bar/baz.py’ 'cfile' will default to
     ‘/foo/bar/__pycache__/baz.cpython-32.pyc’ for Python 3.2.  If
     'dfile' is specified, it is used instead of 'file' as the name of
     the source file from which source lines are obtained for display in
     exception tracebacks.  If 'doraise' is true, a *note
     PyCompileError: 4c72. is raised when an error is encountered while
     compiling 'file'.  If 'doraise' is false (the default), an error
     string is written to ‘sys.stderr’, but no exception is raised.
     This function returns the path to byte-compiled file, i.e.
     whatever 'cfile' value was used.

     The 'doraise' and 'quiet' arguments determine how errors are
     handled while compiling file.  If 'quiet' is 0 or 1, and 'doraise'
     is false, the default behaviour is enabled: an error string is
     written to ‘sys.stderr’, and the function returns ‘None’ instead of
     a path.  If 'doraise' is true, a *note PyCompileError: 4c72. is
     raised instead.  However if 'quiet' is 2, no message is written,
     and 'doraise' has no effect.

     If the path that 'cfile' becomes (either explicitly specified or
     computed) is a symlink or non-regular file, *note FileExistsError:
     1222. will be raised.  This is to act as a warning that import will
     turn those paths into regular files if it is allowed to write
     byte-compiled files to those paths.  This is a side-effect of
     import using file renaming to place the final byte-compiled file
     into place to prevent concurrent file writing issues.

     'optimize' controls the optimization level and is passed to the
     built-in *note compile(): 4b2. function.  The default of ‘-1’
     selects the optimization level of the current interpreter.

     'invalidation_mode' should be a member of the *note
     PycInvalidationMode: 4c73. enum and controls how the generated
     bytecode cache is invalidated at runtime.  The default is *note
     PycInvalidationMode.CHECKED_HASH: 4c74. if the ‘SOURCE_DATE_EPOCH’
     environment variable is set, otherwise the default is *note
     PycInvalidationMode.TIMESTAMP: 4c75.

     Cambiato nella versione 3.2: Changed default value of 'cfile' to be
     PEP 3147(4)-compliant.  Previous default was 'file' + ‘'c'’ (‘'o'’
     if optimization was enabled).  Also added the 'optimize' parameter.

     Cambiato nella versione 3.4: Changed code to use *note importlib:
     7b. for the byte-code cache file writing.  This means file
     creation/writing semantics now match what *note importlib: 7b.
     does, e.g.  permissions, write-and-move semantics, etc.  Also added
     the caveat that *note FileExistsError: 1222. is raised if 'cfile'
     is a symlink or non-regular file.

     Cambiato nella versione 3.7: The 'invalidation_mode' parameter was
     added as specified in PEP 552(5).  If the ‘SOURCE_DATE_EPOCH’
     environment variable is set, 'invalidation_mode' will be forced to
     *note PycInvalidationMode.CHECKED_HASH: 4c74.

     Cambiato nella versione 3.7.2: The ‘SOURCE_DATE_EPOCH’ environment
     variable no longer overrides the value of the 'invalidation_mode'
     argument, and determines its default value instead.

     Cambiato nella versione 3.8: The 'quiet' parameter was added.

 -- Classe: py_compile.PycInvalidationMode

     An enumeration of possible methods the interpreter can use to
     determine whether a bytecode file is up to date with a source file.
     The ‘.pyc’ file indicates the desired invalidation mode in its
     header.  See *note Cached bytecode invalidation: 803. for more
     information on how Python invalidates ‘.pyc’ files at runtime.

     Added in version 3.7.

      -- Attributo: TIMESTAMP

          The ‘.pyc’ file includes the timestamp and size of the source
          file, which Python will compare against the metadata of the
          source file at runtime to determine if the ‘.pyc’ file needs
          to be regenerated.

      -- Attributo: CHECKED_HASH

          The ‘.pyc’ file includes a hash of the source file content,
          which Python will compare against the source at runtime to
          determine if the ‘.pyc’ file needs to be regenerated.

      -- Attributo: UNCHECKED_HASH

          Like *note CHECKED_HASH: 4c74, the ‘.pyc’ file includes a hash
          of the source file content.  However, Python will at runtime
          assume the ‘.pyc’ file is up to date and not validate the
          ‘.pyc’ against the source file at all.

          This option is useful when the ‘.pycs’ are kept up to date by
          some system external to Python like a build system.

* Menu:

* Command-Line Interface: Command-Line Interface<5>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/py_compile.py

   (2) https://peps.python.org/pep-3147/

   (3) https://peps.python.org/pep-0488/

   (4) https://peps.python.org/pep-3147/

   (5) https://peps.python.org/pep-0552/


File: python.info,  Node: Command-Line Interface<5>,  Up: py_compile — Compile Python source files

5.32.8.1 Command-Line Interface
...............................

This module can be invoked as a script to compile several source files.
The files named in 'filenames' are compiled and the resulting bytecode
is cached in the normal manner.  This program does not search a
directory structure to locate source files; it only compiles files named
explicitly.  The exit status is nonzero if one of the files could not be
compiled.

 -- Option: <file> ... <fileN>
 -- Option: -

     Positional arguments are files to compile.  If ‘-’ is the only
     parameter, the list of files is taken from standard input.

 -- Option: -q, --quiet

     Suppress errors output.

Cambiato nella versione 3.2: Added support for ‘-’.

Cambiato nella versione 3.10: Added support for *note -q: 4c7b.

Vedi anche
..........

Module *note compileall: 21.

     Utilities to compile all Python source files in a directory tree.


File: python.info,  Node: compileall — Byte-compile Python libraries,  Next: dis — Disassembler for Python bytecode,  Prev: py_compile — Compile Python source files,  Up: Python Language Services

5.32.9 ‘compileall’ — Byte-compile Python libraries
---------------------------------------------------

'Source code:' Lib/compileall.py(1)

__________________________________________________________________

This module provides some utility functions to support installing Python
libraries.  These functions compile Python source files in a directory
tree.  This module can be used to create the cached byte-code files at
library installation time, which makes them available for use even by
users who don’t have write permission to the library directories.

*note Availability: 2128.: not WASI.

This module does not work or is not available on WebAssembly.  See *note
WebAssembly platforms: 1b52. for more information.

* Menu:

* Command-line use::
* Public functions::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/compileall.py


File: python.info,  Node: Command-line use,  Next: Public functions,  Up: compileall — Byte-compile Python libraries

5.32.9.1 Command-line use
.........................

This module can work as a script (using ‘python -m compileall’) to
compile Python sources.

 -- Option: directory ...
 -- Option: file ...

     Positional arguments are files to compile or directories that
     contain source files, traversed recursively.  If no argument is
     given, behave as if the command line was ‘-l <DIRECTORIES FROM
     SYS.PATH>’.

 -- Option: -l

     Do not recurse into subdirectories, only compile source code files
     directly contained in the named or implied directories.

 -- Option: -f

     Force rebuild even if timestamps are up-to-date.

 -- Option: -q

     Do not print the list of files compiled.  If passed once, error
     messages will still be printed.  If passed twice (‘-qq’), all
     output is suppressed.

 -- Option: -d destdir

     Directory prepended to the path to each file being compiled.  This
     will appear in compilation time tracebacks, and is also compiled in
     to the byte-code file, where it will be used in tracebacks and
     other messages in cases where the source file does not exist at the
     time the byte-code file is executed.

 -- Option: -s strip_prefix

     Remove the given prefix from paths recorded in the ‘.pyc’ files.
     Paths are made relative to the prefix.

     This option can be used with ‘-p’ but not with ‘-d’.

 -- Option: -p prepend_prefix

     Prepend the given prefix to paths recorded in the ‘.pyc’ files.
     Use ‘-p /’ to make the paths absolute.

     This option can be used with ‘-s’ but not with ‘-d’.

 -- Option: -x regex

     regex is used to search the full path to each file considered for
     compilation, and if the regex produces a match, the file is
     skipped.

 -- Option: -i list

     Read the file ‘list’ and add each line that it contains to the list
     of files and directories to compile.  If ‘list’ is ‘-’, read lines
     from ‘stdin’.

 -- Option: -b

     Write the byte-code files to their legacy locations and names,
     which may overwrite byte-code files created by another version of
     Python.  The default is to write files to their PEP 3147(1)
     locations and names, which allows byte-code files from multiple
     versions of Python to coexist.

 -- Option: -r

     Control the maximum recursion level for subdirectories.  If this is
     given, then ‘-l’ option will not be taken into account.  ‘python -m
     compileall <directory> -r 0’ is equivalent to ‘python -m compileall
     <directory> -l’.

 -- Option: -j N

     Use 'N' workers to compile the files within the given directory.
     If ‘0’ is used, then the result of *note os.process_cpu_count():
     4db. will be used.

 -- Option: --invalidation-mode [timestamp|checked-hash|unchecked-hash]

     Control how the generated byte-code files are invalidated at
     runtime.  The ‘timestamp’ value, means that ‘.pyc’ files with the
     source timestamp and size embedded will be generated.  The
     ‘checked-hash’ and ‘unchecked-hash’ values cause hash-based pycs to
     be generated.  Hash-based pycs embed a hash of the source file
     contents rather than a timestamp.  See *note Cached bytecode
     invalidation: 803. for more information on how Python validates
     bytecode cache files at runtime.  The default is ‘timestamp’ if the
     ‘SOURCE_DATE_EPOCH’ environment variable is not set, and
     ‘checked-hash’ if the ‘SOURCE_DATE_EPOCH’ environment variable is
     set.

 -- Option: -o level

     Compile with the given optimization level.  May be used multiple
     times to compile for multiple levels at a time (for example,
     ‘compileall -o 1 -o 2’).

 -- Option: -e dir

     Ignore symlinks pointing outside the given directory.

 -- Option: --hardlink-dupes

     If two ‘.pyc’ files with different optimization level have the same
     content, use hard links to consolidate duplicate files.

Cambiato nella versione 3.2: Added the ‘-i’, ‘-b’ and ‘-h’ options.

Cambiato nella versione 3.5: Added the ‘-j’, ‘-r’, and ‘-qq’ options.
‘-q’ option was changed to a multilevel value.  ‘-b’ will always produce
a byte-code file ending in ‘.pyc’, never ‘.pyo’.

Cambiato nella versione 3.7: Added the ‘--invalidation-mode’ option.

Cambiato nella versione 3.9: Added the ‘-s’, ‘-p’, ‘-e’ and
‘--hardlink-dupes’ options.  Raised the default recursion limit from 10
to *note sys.getrecursionlimit(): 6ec.  Added the possibility to specify
the ‘-o’ option multiple times.

There is no command-line option to control the optimization level used
by the *note compile(): 4b2. function, because the Python interpreter
itself already provides the option: ‘python -O -m compileall’.

Similarly, the *note compile(): 4b2. function respects the *note
sys.pycache_prefix: b9e. setting.  The generated bytecode cache will
only be useful if *note compile(): 4b2. is run with the same *note
sys.pycache_prefix: b9e. (if any) that will be used at runtime.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3147/


File: python.info,  Node: Public functions,  Prev: Command-line use,  Up: compileall — Byte-compile Python libraries

5.32.9.2 Public functions
.........................

 -- Funzione: compileall.compile_dir (dir,
          maxlevels=sys.getrecursionlimit(), ddir=None, force=False,
          rx=None, quiet=0, legacy=False, optimize=-1, workers=1,
          invalidation_mode=None, *, stripdir=None, prependdir=None,
          limit_sl_dest=None, hardlink_dupes=False)

     Recursively descend the directory tree named by 'dir', compiling
     all ‘.py’ files along the way.  Return a true value if all the
     files compiled successfully, and a false value otherwise.

     The 'maxlevels' parameter is used to limit the depth of the
     recursion; it defaults to ‘sys.getrecursionlimit()’.

     If 'ddir' is given, it is prepended to the path to each file being
     compiled for use in compilation time tracebacks, and is also
     compiled in to the byte-code file, where it will be used in
     tracebacks and other messages in cases where the source file does
     not exist at the time the byte-code file is executed.

     If 'force' is true, modules are re-compiled even if the timestamps
     are up to date.

     If 'rx' is given, its ‘search’ method is called on the complete
     path to each file considered for compilation, and if it returns a
     true value, the file is skipped.  This can be used to exclude files
     matching a regular expression, given as a *note re.Pattern: 1189.
     object.

     If 'quiet' is ‘False’ or ‘0’ (the default), the filenames and other
     information are printed to standard out.  Set to ‘1’, only errors
     are printed.  Set to ‘2’, all output is suppressed.

     If 'legacy' is true, byte-code files are written to their legacy
     locations and names, which may overwrite byte-code files created by
     another version of Python.  The default is to write files to their
     PEP 3147(1) locations and names, which allows byte-code files from
     multiple versions of Python to coexist.

     'optimize' specifies the optimization level for the compiler.  It
     is passed to the built-in *note compile(): 4b2. function.  Accepts
     also a sequence of optimization levels which lead to multiple
     compilations of one ‘.py’ file in one call.

     The argument 'workers' specifies how many workers are used to
     compile files in parallel.  The default is to not use multiple
     workers.  If the platform can’t use multiple workers and 'workers'
     argument is given, then sequential compilation will be used as a
     fallback.  If 'workers' is 0, the number of cores in the system is
     used.  If 'workers' is lower than ‘0’, a *note ValueError: 2ec.
     will be raised.

     'invalidation_mode' should be a member of the *note
     py_compile.PycInvalidationMode: 4c73. enum and controls how the
     generated pycs are invalidated at runtime.

     The 'stripdir', 'prependdir' and 'limit_sl_dest' arguments
     correspond to the ‘-s’, ‘-p’ and ‘-e’ options described above.
     They may be specified as ‘str’ or *note os.PathLike: e4d.

     If 'hardlink_dupes' is true and two ‘.pyc’ files with different
     optimization level have the same content, use hard links to
     consolidate duplicate files.

     Cambiato nella versione 3.2: Added the 'legacy' and 'optimize'
     parameter.

     Cambiato nella versione 3.5: Added the 'workers' parameter.

     Cambiato nella versione 3.5: 'quiet' parameter was changed to a
     multilevel value.

     Cambiato nella versione 3.5: The 'legacy' parameter only writes out
     ‘.pyc’ files, not ‘.pyo’ files no matter what the value of
     'optimize' is.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

     Cambiato nella versione 3.7: The 'invalidation_mode' parameter was
     added.

     Cambiato nella versione 3.7.2: The 'invalidation_mode' parameter’s
     default value is updated to ‘None’.

     Cambiato nella versione 3.8: Setting 'workers' to 0 now chooses the
     optimal number of cores.

     Cambiato nella versione 3.9: Added 'stripdir', 'prependdir',
     'limit_sl_dest' and 'hardlink_dupes' arguments.  Default value of
     'maxlevels' was changed from ‘10’ to ‘sys.getrecursionlimit()’

 -- Funzione: compileall.compile_file (fullname, ddir=None, force=False,
          rx=None, quiet=0, legacy=False, optimize=-1,
          invalidation_mode=None, *, stripdir=None, prependdir=None,
          limit_sl_dest=None, hardlink_dupes=False)

     Compile the file with path 'fullname'.  Return a true value if the
     file compiled successfully, and a false value otherwise.

     If 'ddir' is given, it is prepended to the path to the file being
     compiled for use in compilation time tracebacks, and is also
     compiled in to the byte-code file, where it will be used in
     tracebacks and other messages in cases where the source file does
     not exist at the time the byte-code file is executed.

     If 'rx' is given, its ‘search’ method is passed the full path name
     to the file being compiled, and if it returns a true value, the
     file is not compiled and ‘True’ is returned.  This can be used to
     exclude files matching a regular expression, given as a *note
     re.Pattern: 1189. object.

     If 'quiet' is ‘False’ or ‘0’ (the default), the filenames and other
     information are printed to standard out.  Set to ‘1’, only errors
     are printed.  Set to ‘2’, all output is suppressed.

     If 'legacy' is true, byte-code files are written to their legacy
     locations and names, which may overwrite byte-code files created by
     another version of Python.  The default is to write files to their
     PEP 3147(2) locations and names, which allows byte-code files from
     multiple versions of Python to coexist.

     'optimize' specifies the optimization level for the compiler.  It
     is passed to the built-in *note compile(): 4b2. function.  Accepts
     also a sequence of optimization levels which lead to multiple
     compilations of one ‘.py’ file in one call.

     'invalidation_mode' should be a member of the *note
     py_compile.PycInvalidationMode: 4c73. enum and controls how the
     generated pycs are invalidated at runtime.

     The 'stripdir', 'prependdir' and 'limit_sl_dest' arguments
     correspond to the ‘-s’, ‘-p’ and ‘-e’ options described above.
     They may be specified as ‘str’ or *note os.PathLike: e4d.

     If 'hardlink_dupes' is true and two ‘.pyc’ files with different
     optimization level have the same content, use hard links to
     consolidate duplicate files.

     Added in version 3.2.

     Cambiato nella versione 3.5: 'quiet' parameter was changed to a
     multilevel value.

     Cambiato nella versione 3.5: The 'legacy' parameter only writes out
     ‘.pyc’ files, not ‘.pyo’ files no matter what the value of
     'optimize' is.

     Cambiato nella versione 3.7: The 'invalidation_mode' parameter was
     added.

     Cambiato nella versione 3.7.2: The 'invalidation_mode' parameter’s
     default value is updated to ‘None’.

     Cambiato nella versione 3.9: Added 'stripdir', 'prependdir',
     'limit_sl_dest' and 'hardlink_dupes' arguments.

 -- Funzione: compileall.compile_path (skip_curdir=True, maxlevels=0,
          force=False, quiet=0, legacy=False, optimize=-1,
          invalidation_mode=None)

     Byte-compile all the ‘.py’ files found along ‘sys.path’.  Return a
     true value if all the files compiled successfully, and a false
     value otherwise.

     If 'skip_curdir' is true (the default), the current directory is
     not included in the search.  All other parameters are passed to the
     *note compile_dir(): d1d. function.  Note that unlike the other
     compile functions, ‘maxlevels’ defaults to ‘0’.

     Cambiato nella versione 3.2: Added the 'legacy' and 'optimize'
     parameter.

     Cambiato nella versione 3.5: 'quiet' parameter was changed to a
     multilevel value.

     Cambiato nella versione 3.5: The 'legacy' parameter only writes out
     ‘.pyc’ files, not ‘.pyo’ files no matter what the value of
     'optimize' is.

     Cambiato nella versione 3.7: The 'invalidation_mode' parameter was
     added.

     Cambiato nella versione 3.7.2: The 'invalidation_mode' parameter’s
     default value is updated to ‘None’.

To force a recompile of all the ‘.py’ files in the ‘Lib/’ subdirectory
and all its subdirectories:

     import compileall

     compileall.compile_dir('Lib/', force=True)

     # Perform same compilation, excluding files in .svn directories.
     import re
     compileall.compile_dir('Lib/', rx=re.compile(r'[/\\][.]svn'), force=True)

     # pathlib.Path objects can also be used.
     import pathlib
     compileall.compile_dir(pathlib.Path('Lib/'), force=True)

Vedi anche
..........

Module *note py_compile: b8.

     Byte-compile a single source file.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3147/

   (2) https://peps.python.org/pep-3147/


File: python.info,  Node: dis — Disassembler for Python bytecode,  Next: pickletools — Tools for pickle developers,  Prev: compileall — Byte-compile Python libraries,  Up: Python Language Services

5.32.10 ‘dis’ — Disassembler for Python bytecode
------------------------------------------------

'Source code:' Lib/dis.py(1)

__________________________________________________________________

The *note dis: 3c. module supports the analysis of CPython *note
bytecode: 4ab. by disassembling it.  The CPython bytecode which this
module takes as an input is defined in the file ‘Include/opcode.h’ and
used by the compiler and the interpreter.

'Dettaglio dell’implementazione di CPython:' Bytecode is an
implementation detail of the CPython interpreter.  No guarantees are
made that bytecode will not be added, removed, or changed between
versions of Python.  Use of this module should not be considered to work
across Python VMs or Python releases.

Cambiato nella versione 3.6: Use 2 bytes for each instruction.
Previously the number of bytes varied by instruction.

Cambiato nella versione 3.10: The argument of jump, exception handling
and loop instructions is now the instruction offset rather than the byte
offset.

Cambiato nella versione 3.11: Some instructions are accompanied by one
or more inline cache entries, which take the form of *note CACHE: 909.
instructions.  These instructions are hidden by default, but can be
shown by passing ‘show_caches=True’ to any *note dis: 3c. utility.
Furthermore, the interpreter now adapts the bytecode to specialize it
for different runtime conditions.  The adaptive bytecode can be shown by
passing ‘adaptive=True’.

Cambiato nella versione 3.12: The argument of a jump is the offset of
the target instruction relative to the instruction that appears
immediately after the jump instruction’s *note CACHE: 909. entries.

As a consequence, the presence of the *note CACHE: 909. instructions is
transparent for forward jumps but needs to be taken into account when
reasoning about backward jumps.

Cambiato nella versione 3.13: The output shows logical labels rather
than instruction offsets for jump targets and exception handlers.  The
‘-O’ command line option and the ‘show_offsets’ argument were added.

Cambiato nella versione 3.14: The *note -P: 208. command-line option and
the ‘show_positions’ argument were added.

The *note -S: 209. command-line option is added.

Example: Given the function ‘myfunc()’:

     def myfunc(alist):
         return len(alist)

the following command can be used to display the disassembly of
‘myfunc()’:

     >>> dis.dis(myfunc)
       2           RESUME                   0

       3           LOAD_GLOBAL              1 (len + NULL)
                   LOAD_FAST_BORROW         0 (alist)
                   CALL                     1
                   RETURN_VALUE

(The «2» is a line number).

* Menu:

* Command-line interface: Command-line interface<12>.
* Bytecode analysis::
* Analysis functions::
* Python Bytecode Instructions::
* Opcode collections::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/dis.py


File: python.info,  Node: Command-line interface<12>,  Next: Bytecode analysis,  Up: dis — Disassembler for Python bytecode

5.32.10.1 Command-line interface
................................

The *note dis: 3c. module can be invoked as a script from the command
line:

     python -m dis [-h] [-C] [-O] [-P] [-S] [infile]

The following options are accepted:

 -- Option: -h, --help

     Display usage and exit.

 -- Option: -C, --show-caches

     Show inline caches.

     Added in version 3.13.

 -- Option: -O, --show-offsets

     Show offsets of instructions.

     Added in version 3.13.

 -- Option: -P, --show-positions

     Show positions of instructions in the source code.

     Added in version 3.14.

 -- Option: -S, --specialized

     Show specialized bytecode.

     Added in version 3.14.

If ‘infile’ is specified, its disassembled code will be written to
stdout.  Otherwise, disassembly is performed on compiled source code
received from stdin.


File: python.info,  Node: Bytecode analysis,  Next: Analysis functions,  Prev: Command-line interface<12>,  Up: dis — Disassembler for Python bytecode

5.32.10.2 Bytecode analysis
...........................

Added in version 3.4.

The bytecode analysis API allows pieces of Python code to be wrapped in
a *note Bytecode: 204. object that provides easy access to details of
the compiled code.

 -- Classe: dis.Bytecode (x, *, first_line=None, current_offset=None,
          show_caches=False, adaptive=False, show_offsets=False,
          show_positions=False)

     Analyse the bytecode corresponding to a function, generator,
     asynchronous generator, coroutine, method, string of source code,
     or a code object (as returned by *note compile(): 4b2.).

     This is a convenience wrapper around many of the functions listed
     below, most notably *note get_instructions(): 4ed, as iterating
     over a *note Bytecode: 204. instance yields the bytecode operations
     as *note Instruction: 203. instances.

     If 'first_line' is not ‘None’, it indicates the line number that
     should be reported for the first source line in the disassembled
     code.  Otherwise, the source line information (if any) is taken
     directly from the disassembled code object.

     If 'current_offset' is not ‘None’, it refers to an instruction
     offset in the disassembled code.  Setting this means *note dis():
     1131. will display a «current instruction» marker against the
     specified opcode.

     If 'show_caches' is ‘True’, *note dis(): 1131. will display inline
     cache entries used by the interpreter to specialize the bytecode.

     If 'adaptive' is ‘True’, *note dis(): 1131. will display
     specialized bytecode that may be different from the original
     bytecode.

     If 'show_offsets' is ‘True’, *note dis(): 1131. will include
     instruction offsets in the output.

     If 'show_positions' is ‘True’, *note dis(): 1131. will include
     instruction source code positions in the output.

      -- Metodo: classmethod from_traceback (tb, *, show_caches=False)

          Construct a *note Bytecode: 204. instance from the given
          traceback, setting 'current_offset' to the instruction
          responsible for the exception.

      -- Dati: codeobj

          The compiled code object.

      -- Dati: first_line

          The first source line of the code object (if available)

      -- Metodo: dis ()

          Return a formatted view of the bytecode operations (the same
          as printed by *note dis.dis(): 205, but returned as a
          multi-line string).

      -- Metodo: info ()

          Return a formatted multi-line string with detailed information
          about the code object, like *note code_info(): 1441.

     Cambiato nella versione 3.7: This can now handle coroutine and
     asynchronous generator objects.

     Cambiato nella versione 3.11: Added the 'show_caches' and
     'adaptive' parameters.

     Cambiato nella versione 3.13: Added the 'show_offsets' parameter

     Cambiato nella versione 3.14: Added the 'show_positions' parameter.

Example:

     >>> bytecode = dis.Bytecode(myfunc)
     >>> for instr in bytecode:
     ...     print(instr.opname)
     ...
     RESUME
     LOAD_GLOBAL
     LOAD_FAST_BORROW
     CALL
     RETURN_VALUE


File: python.info,  Node: Analysis functions,  Next: Python Bytecode Instructions,  Prev: Bytecode analysis,  Up: dis — Disassembler for Python bytecode

5.32.10.3 Analysis functions
............................

The *note dis: 3c. module also defines the following analysis functions
that convert the input directly to the desired output.  They can be
useful if only a single operation is being performed, so the
intermediate analysis object isn’t useful:

 -- Funzione: dis.code_info (x)

     Return a formatted multi-line string with detailed code object
     information for the supplied function, generator, asynchronous
     generator, coroutine, method, source code string or code object.

     Note that the exact contents of code info strings are highly
     implementation dependent and they may change arbitrarily across
     Python VMs or Python releases.

     Added in version 3.2.

     Cambiato nella versione 3.7: This can now handle coroutine and
     asynchronous generator objects.

 -- Funzione: dis.show_code (x, *, file=None)

     Print detailed code object information for the supplied function,
     method, source code string or code object to 'file' (or
     ‘sys.stdout’ if 'file' is not specified).

     This is a convenient shorthand for ‘print(code_info(x),
     file=file)’, intended for interactive exploration at the
     interpreter prompt.

     Added in version 3.2.

     Cambiato nella versione 3.4: Added 'file' parameter.

 -- Funzione: dis.dis (x=None, *, file=None, depth=None,
          show_caches=False, adaptive=False, show_offsets=False,
          show_positions=False)

     Disassemble the 'x' object.  'x' can denote either a module, a
     class, a method, a function, a generator, an asynchronous
     generator, a coroutine, a code object, a string of source code or a
     byte sequence of raw bytecode.  For a module, it disassembles all
     functions.  For a class, it disassembles all methods (including
     class and static methods).  For a code object or sequence of raw
     bytecode, it prints one line per bytecode instruction.  It also
     recursively disassembles nested code objects.  These can include
     generator expressions, nested functions, the bodies of nested
     classes, and the code objects used for *note annotation scopes:
     4ac.  Strings are first compiled to code objects with the *note
     compile(): 4b2. built-in function before being disassembled.  If no
     object is provided, this function disassembles the last traceback.

     The disassembly is written as text to the supplied 'file' argument
     if provided and to ‘sys.stdout’ otherwise.

     The maximal depth of recursion is limited by 'depth' unless it is
     ‘None’.  ‘depth=0’ means no recursion.

     If 'show_caches' is ‘True’, this function will display inline cache
     entries used by the interpreter to specialize the bytecode.

     If 'adaptive' is ‘True’, this function will display specialized
     bytecode that may be different from the original bytecode.

     Cambiato nella versione 3.4: Added 'file' parameter.

     Cambiato nella versione 3.7: Implemented recursive disassembling
     and added 'depth' parameter.

     Cambiato nella versione 3.7: This can now handle coroutine and
     asynchronous generator objects.

     Cambiato nella versione 3.11: Added the 'show_caches' and
     'adaptive' parameters.

     Cambiato nella versione 3.13: Added the 'show_offsets' parameter.

     Cambiato nella versione 3.14: Added the 'show_positions' parameter.

 -- Funzione: dis.distb (tb=None, *, file=None, show_caches=False,
          adaptive=False, show_offset=False, show_positions=False)

     Disassemble the top-of-stack function of a traceback, using the
     last traceback if none was passed.  The instruction causing the
     exception is indicated.

     The disassembly is written as text to the supplied 'file' argument
     if provided and to ‘sys.stdout’ otherwise.

     Cambiato nella versione 3.4: Added 'file' parameter.

     Cambiato nella versione 3.11: Added the 'show_caches' and
     'adaptive' parameters.

     Cambiato nella versione 3.13: Added the 'show_offsets' parameter.

     Cambiato nella versione 3.14: Added the 'show_positions' parameter.

 -- Funzione: dis.disassemble (code, lasti=-1, *, file=None,
          show_caches=False, adaptive=False, show_offsets=False,
          show_positions=False)
 -- Funzione: dis.disco (code, lasti=-1, *, file=None,
          show_caches=False, adaptive=False, show_offsets=False,
          show_positions=False)

     Disassemble a code object, indicating the last instruction if
     'lasti' was provided.  The output is divided in the following
     columns:

       1. the source code location of the instruction.  Complete
          location information is shown if 'show_positions' is true.
          Otherwise (the default) only the line number is displayed.

       2. the current instruction, indicated as ‘-->’,

       3. a labelled instruction, indicated with ‘>>’,

       4. the address of the instruction,

       5. the operation code name,

       6. operation parameters, and

       7. interpretation of the parameters in parentheses.

     The parameter interpretation recognizes local and global variable
     names, constant values, branch targets, and compare operators.

     The disassembly is written as text to the supplied 'file' argument
     if provided and to ‘sys.stdout’ otherwise.

     Cambiato nella versione 3.4: Added 'file' parameter.

     Cambiato nella versione 3.11: Added the 'show_caches' and
     'adaptive' parameters.

     Cambiato nella versione 3.13: Added the 'show_offsets' parameter.

     Cambiato nella versione 3.14: Added the 'show_positions' parameter.

 -- Funzione: dis.get_instructions (x, *, first_line=None,
          show_caches=False, adaptive=False)

     Return an iterator over the instructions in the supplied function,
     method, source code string or code object.

     The iterator generates a series of *note Instruction: 203. named
     tuples giving the details of each operation in the supplied code.

     If 'first_line' is not ‘None’, it indicates the line number that
     should be reported for the first source line in the disassembled
     code.  Otherwise, the source line information (if any) is taken
     directly from the disassembled code object.

     The 'adaptive' parameter works as it does in *note dis(): 3c.

     Added in version 3.4.

     Cambiato nella versione 3.11: Added the 'show_caches' and
     'adaptive' parameters.

     Cambiato nella versione 3.13: The 'show_caches' parameter is
     deprecated and has no effect.  The iterator generates the *note
     Instruction: 203. instances with the 'cache_info' field populated
     (regardless of the value of 'show_caches') and it no longer
     generates separate items for the cache entries.

 -- Funzione: dis.findlinestarts (code)

     This generator function uses the *note co_lines(): 350. method of
     the *note code object: 4e7. 'code' to find the offsets which are
     starts of lines in the source code.  They are generated as
     ‘(offset, lineno)’ pairs.

     Cambiato nella versione 3.6: Line numbers can be decreasing.
     Before, they were always increasing.

     Cambiato nella versione 3.10: The PEP 626(1) *note co_lines(): 350.
     method is used instead of the *note co_firstlineno: 2376. and *note
     co_lnotab: 330. attributes of the *note code object: 4e7.

     Cambiato nella versione 3.13: Line numbers can be ‘None’ for
     bytecode that does not map to source lines.

 -- Funzione: dis.findlabels (code)

     Detect all offsets in the raw compiled bytecode string 'code' which
     are jump targets, and return a list of these offsets.

 -- Funzione: dis.stack_effect (opcode, oparg=None, *, jump=None)

     Compute the stack effect of 'opcode' with argument 'oparg'.

     If the code has a jump target and 'jump' is ‘True’, *note
     stack_effect(): 1133. will return the stack effect of jumping.  If
     'jump' is ‘False’, it will return the stack effect of not jumping.
     And if 'jump' is ‘None’ (default), it will return the maximal stack
     effect of both cases.

     Added in version 3.4.

     Cambiato nella versione 3.8: Added 'jump' parameter.

     Cambiato nella versione 3.13: If ‘oparg’ is omitted (or ‘None’),
     the stack effect is now returned for ‘oparg=0’.  Previously this
     was an error for opcodes that use their arg.  It is also no longer
     an error to pass an integer ‘oparg’ when the ‘opcode’ does not use
     it; the ‘oparg’ in this case is ignored.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0626/


File: python.info,  Node: Python Bytecode Instructions,  Next: Opcode collections,  Prev: Analysis functions,  Up: dis — Disassembler for Python bytecode

5.32.10.4 Python Bytecode Instructions
......................................

The *note get_instructions(): 4ed. function and *note Bytecode: 204.
class provide details of bytecode instructions as *note Instruction:
203. instances:

 -- Classe: dis.Instruction

     Details for a bytecode operation

      -- Dati: opcode

          numeric code for operation, corresponding to the opcode values
          listed below and the bytecode values in the *note Opcode
          collections: 4caa.

      -- Dati: opname

          human readable name for operation

      -- Dati: baseopcode

          numeric code for the base operation if operation is
          specialized; otherwise equal to *note opcode: 4ca9.

      -- Dati: baseopname

          human readable name for the base operation if operation is
          specialized; otherwise equal to *note opname: 4cae.

      -- Dati: arg

          numeric argument to operation (if any), otherwise ‘None’

      -- Dati: oparg

          alias for *note arg: 4caf.

      -- Dati: argval

          resolved arg value (if any), otherwise ‘None’

      -- Dati: argrepr

          human readable description of operation argument (if any),
          otherwise an empty string.

      -- Dati: offset

          start index of operation within bytecode sequence

      -- Dati: start_offset

          start index of operation within bytecode sequence, including
          prefixed ‘EXTENDED_ARG’ operations if present; otherwise equal
          to *note offset: 4cb3.

      -- Dati: cache_offset

          start index of the cache entries following the operation

      -- Dati: end_offset

          end index of the cache entries following the operation

      -- Dati: starts_line

          ‘True’ if this opcode starts a source line, otherwise ‘False’

      -- Dati: line_number

          source line number associated with this opcode (if any),
          otherwise ‘None’

      -- Dati: is_jump_target

          ‘True’ if other code jumps to here, otherwise ‘False’

      -- Dati: jump_target

          bytecode index of the jump target if this is a jump operation,
          otherwise ‘None’

      -- Dati: positions

          *note dis.Positions: 1928. object holding the start and end
          locations that are covered by this instruction.

      -- Dati: cache_info

          Information about the cache entries of this instruction, as
          triplets of the form ‘(name, size, data)’, where the ‘name’
          and ‘size’ describe the cache format and data is the contents
          of the cache.  ‘cache_info’ is ‘None’ if the instruction does
          not have caches.

     Added in version 3.4.

     Cambiato nella versione 3.11: Field ‘positions’ is added.

     Cambiato nella versione 3.13: Changed field ‘starts_line’.

     Added fields ‘start_offset’, ‘cache_offset’, ‘end_offset’,
     ‘baseopname’, ‘baseopcode’, ‘jump_target’, ‘oparg’, ‘line_number’
     and ‘cache_info’.

 -- Classe: dis.Positions

     In case the information is not available, some fields might be
     ‘None’.

      -- Dati: lineno

      -- Dati: end_lineno

      -- Dati: col_offset

      -- Dati: end_col_offset

     Added in version 3.11.

The Python compiler currently generates the following bytecode
instructions.

'General instructions'

In the following, We will refer to the interpreter stack as ‘STACK’ and
describe operations on it as if it was a Python list.  The top of the
stack corresponds to ‘STACK[-1]’ in this language.

 -- Opcode: NOP

     Do nothing code.  Used as a placeholder by the bytecode optimizer,
     and to generate line tracing events.

 -- Opcode: NOT_TAKEN

     Do nothing code.  Used by the interpreter to record *note
     BRANCH_LEFT: 295. and *note BRANCH_RIGHT: 296. events for *note
     sys.monitoring: e0.

     Added in version 3.14.

 -- Opcode: POP_ITER

     Removes the iterator from the top of the stack.

     Added in version 3.14.

 -- Opcode: POP_TOP

     Removes the top-of-stack item:

          STACK.pop()

 -- Opcode: END_FOR

     Removes the top-of-stack item.  Equivalent to ‘POP_TOP’.  Used to
     clean up at the end of loops, hence the name.

     Added in version 3.12.

 -- Opcode: END_SEND

     Implements ‘del STACK[-2]’.  Used to clean up when a generator
     exits.

     Added in version 3.12.

 -- Opcode: COPY (i)

     Push the i-th item to the top of the stack without removing it from
     its original location:

          assert i > 0
          STACK.append(STACK[-i])

     Added in version 3.11.

 -- Opcode: SWAP (i)

     Swap the top of the stack with the i-th element:

          STACK[-i], STACK[-1] = STACK[-1], STACK[-i]

     Added in version 3.11.

 -- Opcode: CACHE

     Rather than being an actual instruction, this opcode is used to
     mark extra space for the interpreter to cache useful data directly
     in the bytecode itself.  It is automatically hidden by all ‘dis’
     utilities, but can be viewed with ‘show_caches=True’.

     Logically, this space is part of the preceding instruction.  Many
     opcodes expect to be followed by an exact number of caches, and
     will instruct the interpreter to skip over them at runtime.

     Populated caches can look like arbitrary instructions, so great
     care should be taken when reading or modifying raw, adaptive
     bytecode containing quickened data.

     Added in version 3.11.

'Unary operations'

Unary operations take the top of the stack, apply the operation, and
push the result back on the stack.

 -- Opcode: UNARY_NEGATIVE

     Implements ‘STACK[-1] = -STACK[-1]’.

 -- Opcode: UNARY_NOT

     Implements ‘STACK[-1] = not STACK[-1]’.

     Cambiato nella versione 3.13: This instruction now requires an
     exact *note bool: 3c3. operand.

 -- Opcode: UNARY_INVERT

     Implements ‘STACK[-1] = ~STACK[-1]’.

 -- Opcode: GET_ITER

     Implements ‘STACK[-1] = iter(STACK[-1])’.

 -- Opcode: GET_YIELD_FROM_ITER

     If ‘STACK[-1]’ is a *note generator iterator: ddb. or *note
     coroutine: 6ba. object it is left as is.  Otherwise, implements
     ‘STACK[-1] = iter(STACK[-1])’.

     Added in version 3.5.

 -- Opcode: TO_BOOL

     Implements ‘STACK[-1] = bool(STACK[-1])’.

     Added in version 3.13.

'Binary and in-place operations'

Binary operations remove the top two items from the stack (‘STACK[-1]’
and ‘STACK[-2]’).  They perform the operation, then put the result back
on the stack.

In-place operations are like binary operations, but the operation is
done in-place when ‘STACK[-2]’ supports it, and the resulting
‘STACK[-1]’ may be (but does not have to be) the original ‘STACK[-2]’.

 -- Opcode: BINARY_OP (op)

     Implements the binary and in-place operators (depending on the
     value of 'op'):

          rhs = STACK.pop()
          lhs = STACK.pop()
          STACK.append(lhs op rhs)

     Added in version 3.11.

     Cambiato nella versione 3.14: With oparg :‘NB_SUBSCR’, implements
     binary subscript (replaces opcode ‘BINARY_SUBSCR’)

 -- Opcode: STORE_SUBSCR

     Implements:

          key = STACK.pop()
          container = STACK.pop()
          value = STACK.pop()
          container[key] = value

 -- Opcode: DELETE_SUBSCR

     Implements:

          key = STACK.pop()
          container = STACK.pop()
          del container[key]

 -- Opcode: BINARY_SLICE

     Implements:

          end = STACK.pop()
          start = STACK.pop()
          container = STACK.pop()
          STACK.append(container[start:end])

     Added in version 3.12.

 -- Opcode: STORE_SLICE

     Implements:

          end = STACK.pop()
          start = STACK.pop()
          container = STACK.pop()
          value = STACK.pop()
          container[start:end] = value

     Added in version 3.12.

'Coroutine opcodes'

 -- Opcode: GET_AWAITABLE (where)

     Implements ‘STACK[-1] = get_awaitable(STACK[-1])’, where
     ‘get_awaitable(o)’ returns ‘o’ if ‘o’ is a coroutine object or a
     generator object with the *note CO_ITERABLE_COROUTINE: 4a42. flag,
     or resolves ‘o.__await__’.

          If the ‘where’ operand is nonzero, it indicates where the
          instruction occurs:

             * ‘1’: After a call to ‘__aenter__’

             * ‘2’: After a call to ‘__aexit__’

     Added in version 3.5.

     Cambiato nella versione 3.11: Previously, this instruction did not
     have an oparg.

 -- Opcode: GET_AITER

     Implements ‘STACK[-1] = STACK[-1].__aiter__()’.

     Added in version 3.5.

     Cambiato nella versione 3.7: Returning awaitable objects from
     ‘__aiter__’ is no longer supported.

 -- Opcode: GET_ANEXT

     Implement ‘STACK.append(get_awaitable(STACK[-1].__anext__()))’ to
     the stack.  See ‘GET_AWAITABLE’ for details about ‘get_awaitable’.

     Added in version 3.5.

 -- Opcode: END_ASYNC_FOR

     Terminates an *note async for: ca3. loop.  Handles an exception
     raised when awaiting a next item.  The stack contains the async
     iterable in ‘STACK[-2]’ and the raised exception in ‘STACK[-1]’.
     Both are popped.  If the exception is not *note StopAsyncIteration:
     1df7, it is re-raised.

     Added in version 3.8.

     Cambiato nella versione 3.11: Exception representation on the stack
     now consist of one, not three, items.

 -- Opcode: CLEANUP_THROW

     Handles an exception raised during a *note throw(): 71d. or *note
     close(): 177b. call through the current frame.  If ‘STACK[-1]’ is
     an instance of *note StopIteration: df7, pop three values from the
     stack and push its ‘value’ member.  Otherwise, re-raise
     ‘STACK[-1]’.

     Added in version 3.12.

'Miscellaneous opcodes'

 -- Opcode: SET_ADD (i)

     Implements:

          item = STACK.pop()
          set.add(STACK[-i], item)

     Used to implement set comprehensions.

 -- Opcode: LIST_APPEND (i)

     Implements:

          item = STACK.pop()
          list.append(STACK[-i], item)

     Used to implement list comprehensions.

 -- Opcode: MAP_ADD (i)

     Implements:

          value = STACK.pop()
          key = STACK.pop()
          dict.__setitem__(STACK[-i], key, value)

     Used to implement dict comprehensions.

     Added in version 3.1.

     Cambiato nella versione 3.8: Map value is ‘STACK[-1]’ and map key
     is ‘STACK[-2]’.  Before, those were reversed.

For all of the *note SET_ADD: 4ccc, *note LIST_APPEND: 4ccd. and *note
MAP_ADD: ca4. instructions, while the added value or key/value pair is
popped off, the container object remains on the stack so that it is
available for further iterations of the loop.

 -- Opcode: RETURN_VALUE

     Returns with ‘STACK[-1]’ to the caller of the function.

 -- Opcode: YIELD_VALUE

     Yields ‘STACK.pop()’ from a *note generator: 1263.

     Cambiato nella versione 3.11: oparg set to be the stack depth.

     Cambiato nella versione 3.12: oparg set to be the exception block
     depth, for efficient closing of generators.

     Cambiato nella versione 3.13: oparg is ‘1’ if this instruction is
     part of a yield-from or await, and ‘0’ otherwise.

 -- Opcode: SETUP_ANNOTATIONS

     Checks whether ‘__annotations__’ is defined in ‘locals()’, if not
     it is set up to an empty ‘dict’.  This opcode is only emitted if a
     class or module body contains *note variable annotations: f53.
     statically.

     Added in version 3.6.

 -- Opcode: POP_EXCEPT

     Pops a value from the stack, which is used to restore the exception
     state.

     Cambiato nella versione 3.11: Exception representation on the stack
     now consist of one, not three, items.

 -- Opcode: RERAISE

     Re-raises the exception currently on top of the stack.  If oparg is
     non-zero, pops an additional value from the stack which is used to
     set *note f_lasti: a8a. of the current frame.

     Added in version 3.9.

     Cambiato nella versione 3.11: Exception representation on the stack
     now consist of one, not three, items.

 -- Opcode: PUSH_EXC_INFO

     Pops a value from the stack.  Pushes the current exception to the
     top of the stack.  Pushes the value originally popped back to the
     stack.  Used in exception handlers.

     Added in version 3.11.

 -- Opcode: CHECK_EXC_MATCH

     Performs exception matching for ‘except’.  Tests whether the
     ‘STACK[-2]’ is an exception matching ‘STACK[-1]’.  Pops ‘STACK[-1]’
     and pushes the boolean result of the test.

     Added in version 3.11.

 -- Opcode: CHECK_EG_MATCH

     Performs exception matching for ‘except*’.  Applies
     ‘split(STACK[-1])’ on the exception group representing ‘STACK[-2]’.

     In case of a match, pops two items from the stack and pushes the
     non-matching subgroup (‘None’ in case of full match) followed by
     the matching subgroup.  When there is no match, pops one item (the
     match type) and pushes ‘None’.

     Added in version 3.11.

 -- Opcode: WITH_EXCEPT_START

     Calls the function in position 4 on the stack with arguments (type,
     val, tb) representing the exception at the top of the stack.  Used
     to implement the call ‘context_manager.__exit__(*exc_info())’ when
     an exception has occurred in a *note with: 186. statement.

     Added in version 3.9.

     Cambiato nella versione 3.11: The ‘__exit__’ function is in
     position 4 of the stack rather than 7.  Exception representation on
     the stack now consist of one, not three, items.

 -- Opcode: LOAD_COMMON_CONSTANT

     Pushes a common constant onto the stack.  The interpreter contains
     a hardcoded list of constants supported by this instruction.  Used
     by the *note assert: b62. statement to load *note AssertionError:
     8b9.

     Added in version 3.14.

 -- Opcode: LOAD_BUILD_CLASS

     Pushes ‘builtins.__build_class__()’ onto the stack.  It is later
     called to construct a class.

 -- Opcode: GET_LEN

     Perform ‘STACK.append(len(STACK[-1]))’.  Used in *note match: a10.
     statements where comparison with structure of pattern is needed.

     Added in version 3.10.

 -- Opcode: MATCH_MAPPING

     If ‘STACK[-1]’ is an instance of *note collections.abc.Mapping:
     ac9. (or, more technically: if it has the *note Py_TPFLAGS_MAPPING:
     1c40. flag set in its *note tp_flags: 1c59.), push ‘True’ onto the
     stack.  Otherwise, push ‘False’.

     Added in version 3.10.

 -- Opcode: MATCH_SEQUENCE

     If ‘STACK[-1]’ is an instance of *note collections.abc.Sequence:
     13cc. and is 'not' an instance of *note str: 169./*note bytes:
     192./*note bytearray: 344. (or, more technically: if it has the
     *note Py_TPFLAGS_SEQUENCE: 1c41. flag set in its *note tp_flags:
     1c59.), push ‘True’ onto the stack.  Otherwise, push ‘False’.

     Added in version 3.10.

 -- Opcode: MATCH_KEYS

     ‘STACK[-1]’ is a tuple of mapping keys, and ‘STACK[-2]’ is the
     match subject.  If ‘STACK[-2]’ contains all of the keys in
     ‘STACK[-1]’, push a *note tuple: 614. containing the corresponding
     values.  Otherwise, push ‘None’.

     Added in version 3.10.

     Cambiato nella versione 3.11: Previously, this instruction also
     pushed a boolean value indicating success (‘True’) or failure
     (‘False’).

 -- Opcode: STORE_NAME (namei)

     Implements ‘name = STACK.pop()’.  'namei' is the index of 'name' in
     the attribute *note co_names: 2375. of the *note code object: 4e7.
     The compiler tries to use *note STORE_FAST: 1a4b. or *note
     STORE_GLOBAL: 4cd6. if possible.

 -- Opcode: DELETE_NAME (namei)

     Implements ‘del name’, where 'namei' is the index into *note
     co_names: 2375. attribute of the *note code object: 4e7.

 -- Opcode: UNPACK_SEQUENCE (count)

     Unpacks ‘STACK[-1]’ into 'count' individual values, which are put
     onto the stack right-to-left.  Require there to be exactly 'count'
     values.:

          assert(len(STACK[-1]) == count)
          STACK.extend(STACK.pop()[:-count-1:-1])

 -- Opcode: UNPACK_EX (counts)

     Implements assignment with a starred target: Unpacks an iterable in
     ‘STACK[-1]’ into individual values, where the total number of
     values can be smaller than the number of items in the iterable: one
     of the new values will be a list of all leftover items.

     The number of values before and after the list value is limited to
     255.

     The number of values before the list value is encoded in the
     argument of the opcode.  The number of values after the list if any
     is encoded using an ‘EXTENDED_ARG’.  As a consequence, the argument
     can be seen as a two bytes values where the low byte of 'counts' is
     the number of values before the list value, the high byte of
     'counts' the number of values after it.

     The extracted values are put onto the stack right-to-left, i.e.
     ‘a, *b, c = d’ will be stored after execution as ‘STACK.extend((a,
     b, c))’.

 -- Opcode: STORE_ATTR (namei)

     Implements:

          obj = STACK.pop()
          value = STACK.pop()
          obj.name = value

     where 'namei' is the index of name in *note co_names: 2375. of the
     *note code object: 4e7.

 -- Opcode: DELETE_ATTR (namei)

     Implements:

          obj = STACK.pop()
          del obj.name

     where 'namei' is the index of name into *note co_names: 2375. of
     the *note code object: 4e7.

 -- Opcode: STORE_GLOBAL (namei)

     Works as *note STORE_NAME: 4cd5, but stores the name as a global.

 -- Opcode: DELETE_GLOBAL (namei)

     Works as *note DELETE_NAME: 4cd7, but deletes a global name.

 -- Opcode: LOAD_CONST (consti)

     Pushes ‘co_consts[consti]’ onto the stack.

 -- Opcode: LOAD_SMALL_INT (i)

     Pushes the integer ‘i’ onto the stack.  ‘i’ must be in ‘range(256)’

     Added in version 3.14.

 -- Opcode: LOAD_NAME (namei)

     Pushes the value associated with ‘co_names[namei]’ onto the stack.
     The name is looked up within the locals, then the globals, then the
     builtins.

 -- Opcode: LOAD_LOCALS

     Pushes a reference to the locals dictionary onto the stack.  This
     is used to prepare namespace dictionaries for *note
     LOAD_FROM_DICT_OR_DEREF: 70d. and *note LOAD_FROM_DICT_OR_GLOBALS:
     70e.

     Added in version 3.12.

 -- Opcode: LOAD_FROM_DICT_OR_GLOBALS (i)

     Pops a mapping off the stack and looks up the value for
     ‘co_names[namei]’.  If the name is not found there, looks it up in
     the globals and then the builtins, similar to *note LOAD_GLOBAL:
     1a42.  This is used for loading global variables in *note
     annotation scopes: 4ac. within class bodies.

     Added in version 3.12.

 -- Opcode: BUILD_TEMPLATE

     Constructs a new *note Template: 16a. instance from a tuple of
     strings and a tuple of interpolations and pushes the resulting
     object onto the stack:

          interpolations = STACK.pop()
          strings = STACK.pop()
          STACK.append(_build_template(strings, interpolations))

     Added in version 3.14.

 -- Opcode: BUILD_INTERPOLATION (format)

     Constructs a new *note Interpolation: 16b. instance from a value
     and its source expression and pushes the resulting object onto the
     stack.

     If no conversion or format specification is present, ‘format’ is
     set to ‘2’.

     If the low bit of ‘format’ is set, it indicates that the
     interpolation contains a format specification.

     If ‘format >> 2’ is non-zero, it indicates that the interpolation
     contains a conversion.  The value of ‘format >> 2’ is the
     conversion type (‘0’ for no conversion, ‘1’ for ‘!s’, ‘2’ for ‘!r’,
     and ‘3’ for ‘!a’):

          conversion = format >> 2
          if format & 1:
              format_spec = STACK.pop()
          else:
              format_spec = None
          expression = STACK.pop()
          value = STACK.pop()
          STACK.append(_build_interpolation(value, expression, conversion, format_spec))

     Added in version 3.14.

 -- Opcode: BUILD_TUPLE (count)

     Creates a tuple consuming 'count' items from the stack, and pushes
     the resulting tuple onto the stack:

          if count == 0:
              value = ()
          else:
              value = tuple(STACK[-count:])
              STACK = STACK[:-count]

          STACK.append(value)

 -- Opcode: BUILD_LIST (count)

     Works as *note BUILD_TUPLE: 4cdd, but creates a list.

 -- Opcode: BUILD_SET (count)

     Works as *note BUILD_TUPLE: 4cdd, but creates a set.

 -- Opcode: BUILD_MAP (count)

     Pushes a new dictionary object onto the stack.  Pops ‘2 * count’
     items so that the dictionary holds 'count' entries: ‘{...,
     STACK[-4]: STACK[-3], STACK[-2]: STACK[-1]}’.

     Cambiato nella versione 3.5: The dictionary is created from stack
     items instead of creating an empty dictionary pre-sized to hold
     'count' items.

 -- Opcode: BUILD_STRING (count)

     Concatenates 'count' strings from the stack and pushes the
     resulting string onto the stack.

     Added in version 3.6.

 -- Opcode: LIST_EXTEND (i)

     Implements:

          seq = STACK.pop()
          list.extend(STACK[-i], seq)

     Used to build lists.

     Added in version 3.9.

 -- Opcode: SET_UPDATE (i)

     Implements:

          seq = STACK.pop()
          set.update(STACK[-i], seq)

     Used to build sets.

     Added in version 3.9.

 -- Opcode: DICT_UPDATE (i)

     Implements:

          map = STACK.pop()
          dict.update(STACK[-i], map)

     Used to build dicts.

     Added in version 3.9.

 -- Opcode: DICT_MERGE (i)

     Like *note DICT_UPDATE: 4ce2. but raises an exception for duplicate
     keys.

     Added in version 3.9.

 -- Opcode: LOAD_ATTR (namei)

     If the low bit of ‘namei’ is not set, this replaces ‘STACK[-1]’
     with ‘getattr(STACK[-1], co_names[namei>>1])’.

     If the low bit of ‘namei’ is set, this will attempt to load a
     method named ‘co_names[namei>>1]’ from the ‘STACK[-1]’ object.
     ‘STACK[-1]’ is popped.  This bytecode distinguishes two cases: if
     ‘STACK[-1]’ has a method with the correct name, the bytecode pushes
     the unbound method and ‘STACK[-1]’.  ‘STACK[-1]’ will be used as
     the first argument (‘self’) by *note CALL: 916. or *note CALL_KW:
     372. when calling the unbound method.  Otherwise, ‘NULL’ and the
     object returned by the attribute lookup are pushed.

     Cambiato nella versione 3.12: If the low bit of ‘namei’ is set,
     then a ‘NULL’ or ‘self’ is pushed to the stack before the attribute
     or unbound method respectively.

 -- Opcode: LOAD_SUPER_ATTR (namei)

     This opcode implements *note super(): 1a6, both in its
     zero-argument and two-argument forms (e.g.  ‘super().method()’,
     ‘super().attr’ and ‘super(cls, self).method()’, ‘super(cls,
     self).attr’).

     It pops three values from the stack (from top of stack down):

        * ‘self’: the first argument to the current method

        * ‘cls’: the class within which the current method was defined

        * the global ‘super’

     With respect to its argument, it works similarly to *note
     LOAD_ATTR: 705, except that ‘namei’ is shifted left by 2 bits
     instead of 1.

     The low bit of ‘namei’ signals to attempt a method load, as with
     *note LOAD_ATTR: 705, which results in pushing ‘NULL’ and the
     loaded method.  When it is unset a single value is pushed to the
     stack.

     The second-low bit of ‘namei’, if set, means that this was a
     two-argument call to *note super(): 1a6. (unset means
     zero-argument).

     Added in version 3.12.

 -- Opcode: COMPARE_OP (opname)

     Performs a Boolean operation.  The operation name can be found in
     ‘cmp_op[opname >> 5]’.  If the fifth-lowest bit of ‘opname’ is set
     (‘opname & 16’), the result should be coerced to ‘bool’.

     Cambiato nella versione 3.13: The fifth-lowest bit of the oparg now
     indicates a forced conversion to *note bool: 3c3.

 -- Opcode: IS_OP (invert)

     Performs ‘is’ comparison, or ‘is not’ if ‘invert’ is 1.

     Added in version 3.9.

 -- Opcode: CONTAINS_OP (invert)

     Performs ‘in’ comparison, or ‘not in’ if ‘invert’ is 1.

     Added in version 3.9.

 -- Opcode: IMPORT_NAME (namei)

     Imports the module ‘co_names[namei]’.  ‘STACK[-1]’ and ‘STACK[-2]’
     are popped and provide the 'fromlist' and 'level' arguments of
     *note __import__(): ad3.  The module object is pushed onto the
     stack.  The current namespace is not affected: for a proper import
     statement, a subsequent *note STORE_FAST: 1a4b. instruction
     modifies the namespace.

 -- Opcode: IMPORT_FROM (namei)

     Loads the attribute ‘co_names[namei]’ from the module found in
     ‘STACK[-1]’.  The resulting object is pushed onto the stack, to be
     subsequently stored by a *note STORE_FAST: 1a4b. instruction.

 -- Opcode: JUMP_FORWARD (delta)

     Increments bytecode counter by 'delta'.

 -- Opcode: JUMP_BACKWARD (delta)

     Decrements bytecode counter by 'delta'.  Checks for interrupts.

     Added in version 3.11.

 -- Opcode: JUMP_BACKWARD_NO_INTERRUPT (delta)

     Decrements bytecode counter by 'delta'.  Does not check for
     interrupts.

     Added in version 3.11.

 -- Opcode: POP_JUMP_IF_TRUE (delta)

     If ‘STACK[-1]’ is true, increments the bytecode counter by 'delta'.
     ‘STACK[-1]’ is popped.

     Cambiato nella versione 3.11: The oparg is now a relative delta
     rather than an absolute target.  This opcode is a
     pseudo-instruction, replaced in final bytecode by the directed
     versions (forward/backward).

     Cambiato nella versione 3.12: This is no longer a
     pseudo-instruction.

     Cambiato nella versione 3.13: This instruction now requires an
     exact *note bool: 3c3. operand.

 -- Opcode: POP_JUMP_IF_FALSE (delta)

     If ‘STACK[-1]’ is false, increments the bytecode counter by
     'delta'.  ‘STACK[-1]’ is popped.

     Cambiato nella versione 3.11: The oparg is now a relative delta
     rather than an absolute target.  This opcode is a
     pseudo-instruction, replaced in final bytecode by the directed
     versions (forward/backward).

     Cambiato nella versione 3.12: This is no longer a
     pseudo-instruction.

     Cambiato nella versione 3.13: This instruction now requires an
     exact *note bool: 3c3. operand.

 -- Opcode: POP_JUMP_IF_NOT_NONE (delta)

     If ‘STACK[-1]’ is not ‘None’, increments the bytecode counter by
     'delta'.  ‘STACK[-1]’ is popped.

     Added in version 3.11.

     Cambiato nella versione 3.12: This is no longer a
     pseudo-instruction.

 -- Opcode: POP_JUMP_IF_NONE (delta)

     If ‘STACK[-1]’ is ‘None’, increments the bytecode counter by
     'delta'.  ‘STACK[-1]’ is popped.

     Added in version 3.11.

     Cambiato nella versione 3.12: This is no longer a
     pseudo-instruction.

 -- Opcode: FOR_ITER (delta)

     ‘STACK[-1]’ is an *note iterator: 4c9.  Call its *note __next__():
     14d5. method.  If this yields a new value, push it on the stack
     (leaving the iterator below it).  If the iterator indicates it is
     exhausted then the byte code counter is incremented by 'delta'.

     Cambiato nella versione 3.12: Up until 3.11 the iterator was popped
     when it was exhausted.

 -- Opcode: LOAD_GLOBAL (namei)

     Loads the global named ‘co_names[namei>>1]’ onto the stack.

     Cambiato nella versione 3.11: If the low bit of ‘namei’ is set,
     then a ‘NULL’ is pushed to the stack before the global variable.

 -- Opcode: LOAD_FAST (var_num)

     Pushes a reference to the local ‘co_varnames[var_num]’ onto the
     stack.

     Cambiato nella versione 3.12: This opcode is now only used in
     situations where the local variable is guaranteed to be
     initialized.  It cannot raise *note UnboundLocalError: 173d.

 -- Opcode: LOAD_FAST_BORROW (var_num)

     Pushes a borrowed reference to the local ‘co_varnames[var_num]’
     onto the stack.

     Added in version 3.14.

 -- Opcode: LOAD_FAST_LOAD_FAST (var_nums)

     Pushes references to ‘co_varnames[var_nums >> 4]’ and
     ‘co_varnames[var_nums & 15]’ onto the stack.

     Added in version 3.13.

 -- Opcode: LOAD_FAST_BORROW_LOAD_FAST_BORROW (var_nums)

     Pushes borrowed references to ‘co_varnames[var_nums >> 4]’ and
     ‘co_varnames[var_nums & 15]’ onto the stack.

     Added in version 3.14.

 -- Opcode: LOAD_FAST_CHECK (var_num)

     Pushes a reference to the local ‘co_varnames[var_num]’ onto the
     stack, raising an *note UnboundLocalError: 173d. if the local
     variable has not been initialized.

     Added in version 3.12.

 -- Opcode: LOAD_FAST_AND_CLEAR (var_num)

     Pushes a reference to the local ‘co_varnames[var_num]’ onto the
     stack (or pushes ‘NULL’ onto the stack if the local variable has
     not been initialized) and sets ‘co_varnames[var_num]’ to ‘NULL’.

     Added in version 3.12.

 -- Opcode: STORE_FAST (var_num)

     Stores ‘STACK.pop()’ into the local ‘co_varnames[var_num]’.

 -- Opcode: STORE_FAST_STORE_FAST (var_nums)

     Stores ‘STACK[-1]’ into ‘co_varnames[var_nums >> 4]’ and
     ‘STACK[-2]’ into ‘co_varnames[var_nums & 15]’.

     Added in version 3.13.

 -- Opcode: STORE_FAST_LOAD_FAST (var_nums)

     Stores ‘STACK.pop()’ into the local ‘co_varnames[var_nums >> 4]’
     and pushes a reference to the local ‘co_varnames[var_nums & 15]’
     onto the stack.

     Added in version 3.13.

 -- Opcode: DELETE_FAST (var_num)

     Deletes local ‘co_varnames[var_num]’.

 -- Opcode: MAKE_CELL (i)

     Creates a new cell in slot ‘i’.  If that slot is nonempty then that
     value is stored into the new cell.

     Added in version 3.11.

 -- Opcode: LOAD_DEREF (i)

     Loads the cell contained in slot ‘i’ of the «fast locals» storage.
     Pushes a reference to the object the cell contains on the stack.

     Cambiato nella versione 3.11: ‘i’ is no longer offset by the length
     of *note co_varnames: 2371.

 -- Opcode: LOAD_FROM_DICT_OR_DEREF (i)

     Pops a mapping off the stack and looks up the name associated with
     slot ‘i’ of the «fast locals» storage in this mapping.  If the name
     is not found there, loads it from the cell contained in slot ‘i’,
     similar to *note LOAD_DEREF: 4ceb.  This is used for loading *note
     closure variables: 187b. in class bodies (which previously used
     ‘LOAD_CLASSDEREF’) and in *note annotation scopes: 4ac. within
     class bodies.

     Added in version 3.12.

 -- Opcode: STORE_DEREF (i)

     Stores ‘STACK.pop()’ into the cell contained in slot ‘i’ of the
     «fast locals» storage.

     Cambiato nella versione 3.11: ‘i’ is no longer offset by the length
     of *note co_varnames: 2371.

 -- Opcode: DELETE_DEREF (i)

     Empties the cell contained in slot ‘i’ of the «fast locals»
     storage.  Used by the *note del: 1b07. statement.

     Added in version 3.2.

     Cambiato nella versione 3.11: ‘i’ is no longer offset by the length
     of *note co_varnames: 2371.

 -- Opcode: COPY_FREE_VARS (n)

     Copies the ‘n’ *note free (closure) variables: 187b. from the
     closure into the frame.  Removes the need for special code on the
     caller’s side when calling closures.

     Added in version 3.11.

 -- Opcode: RAISE_VARARGS (argc)

     Raises an exception using one of the 3 forms of the ‘raise’
     statement, depending on the value of 'argc':

        * 0: ‘raise’ (re-raise previous exception)

        * 1: ‘raise STACK[-1]’ (raise exception instance or type at
          ‘STACK[-1]’)

        * 2: ‘raise STACK[-2] from STACK[-1]’ (raise exception instance
          or type at ‘STACK[-2]’ with ‘__cause__’ set to ‘STACK[-1]’)

 -- Opcode: CALL (argc)

     Calls a callable object with the number of arguments specified by
     ‘argc’.  On the stack are (in ascending order):

        * The callable

        * ‘self’ or ‘NULL’

        * The remaining positional arguments

     ‘argc’ is the total of the positional arguments, excluding ‘self’.

     ‘CALL’ pops all arguments and the callable object off the stack,
     calls the callable object with those arguments, and pushes the
     return value returned by the callable object.

     Added in version 3.11.

     Cambiato nella versione 3.13: The callable now always appears at
     the same position on the stack.

     Cambiato nella versione 3.13: Calls with keyword arguments are now
     handled by *note CALL_KW: 372.

 -- Opcode: CALL_KW (argc)

     Calls a callable object with the number of arguments specified by
     ‘argc’, including one or more named arguments.  On the stack are
     (in ascending order):

        * The callable

        * ‘self’ or ‘NULL’

        * The remaining positional arguments

        * The named arguments

        * A *note tuple: 614. of keyword argument names

     ‘argc’ is the total of the positional and named arguments,
     excluding ‘self’.  The length of the tuple of keyword argument
     names is the number of named arguments.

     ‘CALL_KW’ pops all arguments, the keyword names, and the callable
     object off the stack, calls the callable object with those
     arguments, and pushes the return value returned by the callable
     object.

     Added in version 3.13.

 -- Opcode: CALL_FUNCTION_EX (flags)

     Calls a callable object with variable set of positional and keyword
     arguments.  If the lowest bit of 'flags' is set, the top of the
     stack contains a mapping object containing additional keyword
     arguments.  Before the callable is called, the mapping object and
     iterable object are each «unpacked» and their contents passed in as
     keyword and positional arguments respectively.  ‘CALL_FUNCTION_EX’
     pops all arguments and the callable object off the stack, calls the
     callable object with those arguments, and pushes the return value
     returned by the callable object.

     Added in version 3.6.

 -- Opcode: PUSH_NULL

     Pushes a ‘NULL’ to the stack.  Used in the call sequence to match
     the ‘NULL’ pushed by ‘LOAD_METHOD’ for non-method calls.

     Added in version 3.11.

 -- Opcode: MAKE_FUNCTION

     Pushes a new function object on the stack built from the code
     object at ‘STACK[-1]’.

     Cambiato nella versione 3.10: Flag value ‘0x04’ is a tuple of
     strings instead of dictionary

     Cambiato nella versione 3.11: Qualified name at ‘STACK[-1]’ was
     removed.

     Cambiato nella versione 3.13: Extra function attributes on the
     stack, signaled by oparg flags, were removed.  They now use *note
     SET_FUNCTION_ATTRIBUTE: 4cef.

 -- Opcode: SET_FUNCTION_ATTRIBUTE (flag)

     Sets an attribute on a function object.  Expects the function at
     ‘STACK[-1]’ and the attribute value to set at ‘STACK[-2]’; consumes
     both and leaves the function at ‘STACK[-1]’.  The flag determines
     which attribute to set:

        * ‘0x01’ a tuple of default values for positional-only and
          positional-or-keyword parameters in positional order

        * ‘0x02’ a dictionary of keyword-only parameters” default values

        * ‘0x04’ a tuple of strings containing parameters” annotations

        * ‘0x08’ a tuple containing cells for free variables, making a
          closure

        * ‘0x10’ the *note annotate function: 15d. for the function
          object

     Added in version 3.13.

     Cambiato nella versione 3.14: Added ‘0x10’ to indicate the annotate
     function for the function object.

 -- Opcode: BUILD_SLICE (argc)

     Pushes a slice object on the stack.  'argc' must be 2 or 3.  If it
     is 2, implements:

          end = STACK.pop()
          start = STACK.pop()
          STACK.append(slice(start, end))

     if it is 3, implements:

          step = STACK.pop()
          end = STACK.pop()
          start = STACK.pop()
          STACK.append(slice(start, end, step))

     See the *note slice(): 695. built-in function for more information.

 -- Opcode: EXTENDED_ARG (ext)

     Prefixes any opcode which has an argument too big to fit into the
     default one byte.  'ext' holds an additional byte which act as
     higher bits in the argument.  For each opcode, at most three
     prefixal ‘EXTENDED_ARG’ are allowed, forming an argument from
     two-byte to four-byte.

 -- Opcode: CONVERT_VALUE (oparg)

     Convert value to a string, depending on ‘oparg’:

          value = STACK.pop()
          result = func(value)
          STACK.append(result)

        * ‘oparg == 1’: call *note str(): 169. on 'value'

        * ‘oparg == 2’: call *note repr(): 1c1. on 'value'

        * ‘oparg == 3’: call *note ascii(): 15ed. on 'value'

     Used for implementing formatted string literals (f-strings).

     Added in version 3.13.

 -- Opcode: FORMAT_SIMPLE

     Formats the value on top of stack:

          value = STACK.pop()
          result = value.__format__("")
          STACK.append(result)

     Used for implementing formatted string literals (f-strings).

     Added in version 3.13.

 -- Opcode: FORMAT_WITH_SPEC

     Formats the given value with the given format spec:

          spec = STACK.pop()
          value = STACK.pop()
          result = value.__format__(spec)
          STACK.append(result)

     Used for implementing formatted string literals (f-strings).

     Added in version 3.13.

 -- Opcode: MATCH_CLASS (count)

     ‘STACK[-1]’ is a tuple of keyword attribute names, ‘STACK[-2]’ is
     the class being matched against, and ‘STACK[-3]’ is the match
     subject.  'count' is the number of positional sub-patterns.

     Pop ‘STACK[-1]’, ‘STACK[-2]’, and ‘STACK[-3]’.  If ‘STACK[-3]’ is
     an instance of ‘STACK[-2]’ and has the positional and keyword
     attributes required by 'count' and ‘STACK[-1]’, push a tuple of
     extracted attributes.  Otherwise, push ‘None’.

     Added in version 3.10.

     Cambiato nella versione 3.11: Previously, this instruction also
     pushed a boolean value indicating success (‘True’) or failure
     (‘False’).

 -- Opcode: RESUME (context)

     A no-op.  Performs internal tracing, debugging and optimization
     checks.

     The ‘context’ operand consists of two parts.  The lowest two bits
     indicate where the ‘RESUME’ occurs:

        * ‘0’ The start of a function, which is neither a generator,
          coroutine nor an async generator

        * ‘1’ After a ‘yield’ expression

        * ‘2’ After a ‘yield from’ expression

        * ‘3’ After an ‘await’ expression

     The next bit is ‘1’ if the RESUME is at except-depth ‘1’, and ‘0’
     otherwise.

     Added in version 3.11.

     Cambiato nella versione 3.13: The oparg value changed to include
     information about except-depth

 -- Opcode: RETURN_GENERATOR

     Create a generator, coroutine, or async generator from the current
     frame.  Used as first opcode of in code object for the above
     mentioned callables.  Clear the current frame and return the newly
     created generator.

     Added in version 3.11.

 -- Opcode: SEND (delta)

     Equivalent to ‘STACK[-1] = STACK[-2].send(STACK[-1])’.  Used in
     ‘yield from’ and ‘await’ statements.

     If the call raises *note StopIteration: df7, pop the top value from
     the stack, push the exception’s ‘value’ attribute, and increment
     the bytecode counter by 'delta'.

     Added in version 3.11.

 -- Opcode: HAVE_ARGUMENT

     This is not really an opcode.  It identifies the dividing line
     between opcodes in the range [0,255] which don’t use their argument
     and those that do (‘< HAVE_ARGUMENT’ and ‘>= HAVE_ARGUMENT’,
     respectively).

     If your application uses pseudo instructions or specialized
     instructions, use the *note hasarg: 59f. collection instead.

     Cambiato nella versione 3.6: Now every instruction has an argument,
     but opcodes ‘< HAVE_ARGUMENT’ ignore it.  Before, only opcodes ‘>=
     HAVE_ARGUMENT’ had an argument.

     Cambiato nella versione 3.12: Pseudo instructions were added to the
     *note dis: 3c. module, and for them it is not true that comparison
     with ‘HAVE_ARGUMENT’ indicates whether they use their arg.

     Deprecato dalla versione 3.13: Use *note hasarg: 59f. instead.

 -- Opcode: CALL_INTRINSIC_1

     Calls an intrinsic function with one argument.  Passes ‘STACK[-1]’
     as the argument and sets ‘STACK[-1]’ to the result.  Used to
     implement functionality that is not performance critical.

     The operand determines which intrinsic function is called:

     Operand                                 Description
                                             
     --------------------------------------------------------------------------------
                                             
     ‘INTRINSIC_1_INVALID’                   Not valid
                                             
                                             
     ‘INTRINSIC_PRINT’                       Prints the argument to standard out.
                                             Used in the REPL.
                                             
                                             
     ‘INTRINSIC_IMPORT_STAR’                 Performs ‘import *’ for the named
                                             module.
                                             
                                             
     ‘INTRINSIC_STOPITERATION_ERROR’         Extracts the return value from a
                                             ‘StopIteration’ exception.
                                             
                                             
     ‘INTRINSIC_ASYNC_GEN_WRAP’              Wraps an async generator value
                                             
                                             
     ‘INTRINSIC_UNARY_POSITIVE’              Performs the unary ‘+’ operation
                                             
                                             
     ‘INTRINSIC_LIST_TO_TUPLE’               Converts a list to a tuple
                                             
                                             
     ‘INTRINSIC_TYPEVAR’                     Creates a *note typing.TypeVar: 487.
                                             
                                             
     ‘INTRINSIC_PARAMSPEC’                   Creates a
                                             *note typing.ParamSpec: 488.
                                             
                                             
     ‘INTRINSIC_TYPEVARTUPLE’                Creates a
                                             *note typing.TypeVarTuple: 489.
                                             
                                             
     ‘INTRINSIC_SUBSCRIPT_GENERIC’           Returns *note typing.Generic: 179e.
                                             subscripted with the argument
                                             
                                             
     ‘INTRINSIC_TYPEALIAS’                   Creates a
                                             *note typing.TypeAliasType: 2ae.;
                                             used in the *note type: 66d.
                                             statement.  The argument is a tuple
                                             of the type alias’s name, type
                                             parameters, and value.
                                             

     Added in version 3.12.

 -- Opcode: CALL_INTRINSIC_2

     Calls an intrinsic function with two arguments.  Used to implement
     functionality that is not performance critical:

          arg2 = STACK.pop()
          arg1 = STACK.pop()
          result = intrinsic2(arg1, arg2)
          STACK.append(result)

     The operand determines which intrinsic function is called:

     Operand                                      Description
                                                  
     -------------------------------------------------------------------------------------
                                                  
     ‘INTRINSIC_2_INVALID’                        Not valid
                                                  
                                                  
     ‘INTRINSIC_PREP_RERAISE_STAR’                Calculates the
                                                  *note ExceptionGroup: 4d3. to raise
                                                  from a ‘try-except*’.
                                                  
                                                  
     ‘INTRINSIC_TYPEVAR_WITH_BOUND’               Creates a *note typing.TypeVar: 487.
                                                  with a bound.
                                                  
                                                  
     ‘INTRINSIC_TYPEVAR_WITH_CONSTRAINTS’         Creates a *note typing.TypeVar: 487.
                                                  with constraints.
                                                  
                                                  
     ‘INTRINSIC_SET_FUNCTION_TYPE_PARAMS’         Sets the ‘__type_params__’ attribute
                                                  of a function.
                                                  

     Added in version 3.12.

 -- Opcode: LOAD_SPECIAL

     Performs special method lookup on ‘STACK[-1]’.  If
     ‘type(STACK[-1]).__xxx__’ is a method, leave
     ‘type(STACK[-1]).__xxx__; STACK[-1]’ on the stack.  If
     ‘type(STACK[-1]).__xxx__’ is not a method, leave
     ‘STACK[-1].__xxx__; NULL’ on the stack.

     Added in version 3.14.

'Pseudo-instructions'

These opcodes do not appear in Python bytecode.  They are used by the
compiler but are replaced by real opcodes or removed before bytecode is
generated.

 -- Opcode: SETUP_FINALLY (target)

     Set up an exception handler for the following code block.  If an
     exception occurs, the value stack level is restored to its current
     state and control is transferred to the exception handler at
     ‘target’.

 -- Opcode: SETUP_CLEANUP (target)

     Like ‘SETUP_FINALLY’, but in case of an exception also pushes the
     last instruction (‘lasti’) to the stack so that ‘RERAISE’ can
     restore it.  If an exception occurs, the value stack level and the
     last instruction on the frame are restored to their current state,
     and control is transferred to the exception handler at ‘target’.

 -- Opcode: SETUP_WITH (target)

     Like ‘SETUP_CLEANUP’, but in case of an exception one more item is
     popped from the stack before control is transferred to the
     exception handler at ‘target’.

     This variant is used in *note with: 186. and *note async with: 185.
     constructs, which push the return value of the context manager’s
     *note __enter__(): 7e5. or *note __aenter__(): 2401. to the stack.

 -- Opcode: POP_BLOCK

     Marks the end of the code block associated with the last
     ‘SETUP_FINALLY’, ‘SETUP_CLEANUP’ or ‘SETUP_WITH’.

 -- Opcode: LOAD_CONST_IMMORTAL (consti)

     Works as *note LOAD_CONST: 4cdb, but is more efficient for immortal
     objects.

 -- Opcode: JUMP
 -- Opcode: JUMP_NO_INTERRUPT

     Undirected relative jump instructions which are replaced by their
     directed (forward/backward) counterparts by the assembler.

 -- Opcode: JUMP_IF_TRUE
 -- Opcode: JUMP_IF_FALSE

     Conditional jumps which do not impact the stack.  Replaced by the
     sequence ‘COPY 1’, ‘TO_BOOL’, ‘POP_JUMP_IF_TRUE/FALSE’.

 -- Opcode: LOAD_CLOSURE (i)

     Pushes a reference to the cell contained in slot ‘i’ of the «fast
     locals» storage.

     Note that ‘LOAD_CLOSURE’ is replaced with ‘LOAD_FAST’ in the
     assembler.

     Cambiato nella versione 3.13: This opcode is now a
     pseudo-instruction.


File: python.info,  Node: Opcode collections,  Prev: Python Bytecode Instructions,  Up: dis — Disassembler for Python bytecode

5.32.10.5 Opcode collections
............................

These collections are provided for automatic introspection of bytecode
instructions:

Cambiato nella versione 3.12: The collections now contain pseudo
instructions and instrumented instructions as well.  These are opcodes
with values ‘>= MIN_PSEUDO_OPCODE’ and ‘>= MIN_INSTRUMENTED_OPCODE’.

 -- Dati: dis.opname

     Sequence of operation names, indexable using the bytecode.

 -- Dati: dis.opmap

     Dictionary mapping operation names to bytecodes.

 -- Dati: dis.cmp_op

     Sequence of all compare operation names.

 -- Dati: dis.hasarg

     Sequence of bytecodes that use their argument.

     Added in version 3.12.

 -- Dati: dis.hasconst

     Sequence of bytecodes that access a constant.

 -- Dati: dis.hasfree

     Sequence of bytecodes that access a *note free (closure) variable:
     187b.  “free” in this context refers to names in the current scope
     that are referenced by inner scopes or names in outer scopes that
     are referenced from this scope.  It does 'not' include references
     to global or builtin scopes.

 -- Dati: dis.hasname

     Sequence of bytecodes that access an attribute by name.

 -- Dati: dis.hasjump

     Sequence of bytecodes that have a jump target.  All jumps are
     relative.

     Added in version 3.13.

 -- Dati: dis.haslocal

     Sequence of bytecodes that access a local variable.

 -- Dati: dis.hascompare

     Sequence of bytecodes of Boolean operations.

 -- Dati: dis.hasexc

     Sequence of bytecodes that set an exception handler.

     Added in version 3.12.

 -- Dati: dis.hasjrel

     Sequence of bytecodes that have a relative jump target.

     Deprecato dalla versione 3.13: All jumps are now relative.  Use
     *note hasjump: 4cff.

 -- Dati: dis.hasjabs

     Sequence of bytecodes that have an absolute jump target.

     Deprecato dalla versione 3.13: All jumps are now relative.  This
     list is empty.


File: python.info,  Node: pickletools — Tools for pickle developers,  Prev: dis — Disassembler for Python bytecode,  Up: Python Language Services

5.32.11 ‘pickletools’ — Tools for pickle developers
---------------------------------------------------

'Source code:' Lib/pickletools.py(1)

__________________________________________________________________

This module contains various constants relating to the intimate details
of the *note pickle: ab. module, some lengthy comments about the
implementation, and a few useful functions for analyzing pickled data.
The contents of this module are useful for Python core developers who
are working on the *note pickle: ab.; ordinary users of the *note
pickle: ab. module probably won’t find the *note pickletools: ac. module
relevant.

* Menu:

* Command-line usage: Command-line usage<8>.
* Programmatic interface::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/pickletools.py


File: python.info,  Node: Command-line usage<8>,  Next: Programmatic interface,  Up: pickletools — Tools for pickle developers

5.32.11.1 Command-line usage
............................

Added in version 3.2.

When invoked from the command line, ‘python -m pickletools’ will
disassemble the contents of one or more pickle files.  Note that if you
want to see the Python object stored in the pickle rather than the
details of pickle format, you may want to use ‘-m pickle’ instead.
However, when the pickle file that you want to examine comes from an
untrusted source, ‘-m pickletools’ is a safer option because it does not
execute pickle bytecode.

For example, with a tuple ‘(1, 2)’ pickled in file ‘x.pickle’:

     $ python -m pickle x.pickle
     (1, 2)

     $ python -m pickletools x.pickle
         0: \x80 PROTO      3
         2: K    BININT1    1
         4: K    BININT1    2
         6: \x86 TUPLE2
         7: q    BINPUT     0
         9: .    STOP
     highest protocol among opcodes = 2

* Menu:

* Command-line options: Command-line options<6>.


File: python.info,  Node: Command-line options<6>,  Up: Command-line usage<8>

5.32.11.2 Command-line options
..............................

 -- Option: -a, --annotate

     Annotate each line with a short opcode description.

 -- Option: -o, --output=<file>

     Name of a file where the output should be written.

 -- Option: -l, --indentlevel=<num>

     The number of blanks by which to indent a new MARK level.

 -- Option: -m, --memo

     When multiple objects are disassembled, preserve memo between
     disassemblies.

 -- Option: -p, --preamble=<preamble>

     When more than one pickle file is specified, print given preamble
     before each disassembly.

 -- Option: pickle_file

     A pickle file to read, or ‘-’ to indicate reading from standard
     input.


File: python.info,  Node: Programmatic interface,  Prev: Command-line usage<8>,  Up: pickletools — Tools for pickle developers

5.32.11.3 Programmatic interface
................................

 -- Funzione: pickletools.dis (pickle, out=None, memo=None,
          indentlevel=4, annotate=0)

     Outputs a symbolic disassembly of the pickle to the file-like
     object 'out', defaulting to ‘sys.stdout’.  'pickle' can be a string
     or a file-like object.  'memo' can be a Python dictionary that will
     be used as the pickle’s memo; it can be used to perform
     disassemblies across multiple pickles created by the same pickler.
     Successive levels, indicated by ‘MARK’ opcodes in the stream, are
     indented by 'indentlevel' spaces.  If a nonzero value is given to
     'annotate', each opcode in the output is annotated with a short
     description.  The value of 'annotate' is used as a hint for the
     column where annotation should start.

     Cambiato nella versione 3.2: Added the 'annotate' parameter.

 -- Funzione: pickletools.genops (pickle)

     Provides an *note iterator: 4c9. over all of the opcodes in a
     pickle, returning a sequence of ‘(opcode, arg, pos)’ triples.
     'opcode' is an instance of an ‘OpcodeInfo’ class; 'arg' is the
     decoded value, as a Python object, of the opcode’s argument; 'pos'
     is the position at which this opcode is located.  'pickle' can be a
     string or a file-like object.

 -- Funzione: pickletools.optimize (picklestring)

     Returns a new equivalent pickle string after eliminating unused
     ‘PUT’ opcodes.  The optimized pickle is shorter, takes less
     transmission time, requires less storage space, and unpickles more
     efficiently.


File: python.info,  Node: MS Windows Specific Services,  Next: Unix-specific services,  Prev: Python Language Services,  Up: The Python Standard Library

5.33 MS Windows Specific Services
=================================

This chapter describes modules that are only available on MS Windows
platforms.

* Menu:

* msvcrt — Useful routines from the MS VC++ runtime::
* winreg — Windows registry access::
* winsound — Sound-playing interface for Windows::


File: python.info,  Node: msvcrt — Useful routines from the MS VC++ runtime,  Next: winreg — Windows registry access,  Up: MS Windows Specific Services

5.33.1 ‘msvcrt’ — Useful routines from the MS VC++ runtime
----------------------------------------------------------

__________________________________________________________________

These functions provide access to some useful capabilities on Windows
platforms.  Some higher-level modules use these functions to build the
Windows implementations of their services.  For example, the *note
getpass: 66. module uses this in the implementation of the *note
getpass(): 66. function.

Further documentation on these functions can be found in the Platform
API documentation.

The module implements both the normal and wide char variants of the
console I/O api.  The normal API deals only with ASCII characters and is
of limited use for internationalized applications.  The wide char API
should be used where ever possible.

*note Availability: 2128.: Windows.

Cambiato nella versione 3.3: Operations in this module now raise *note
OSError: 2c0. where *note IOError: 1255. was raised.

* Menu:

* File Operations::
* Console I/O::
* Other Functions::


File: python.info,  Node: File Operations,  Next: Console I/O,  Up: msvcrt — Useful routines from the MS VC++ runtime

5.33.1.1 File Operations
........................

 -- Funzione: msvcrt.locking (fd, mode, nbytes)

     Lock part of a file based on file descriptor 'fd' from the C
     runtime.  Raises *note OSError: 2c0. on failure.  The locked region
     of the file extends from the current file position for 'nbytes'
     bytes, and may continue beyond the end of the file.  'mode' must be
     one of the ‘LK_*’ constants listed below.  Multiple regions in a
     file may be locked at the same time, but may not overlap.  Adjacent
     regions are not merged; they must be unlocked individually.

     Raises an *note auditing event: 1c56. ‘msvcrt.locking’ with
     arguments ‘fd’, ‘mode’, ‘nbytes’.

 -- Dati: msvcrt.LK_LOCK
 -- Dati: msvcrt.LK_RLCK

     Locks the specified bytes.  If the bytes cannot be locked, the
     program immediately tries again after 1 second.  If, after 10
     attempts, the bytes cannot be locked, *note OSError: 2c0. is
     raised.

 -- Dati: msvcrt.LK_NBLCK
 -- Dati: msvcrt.LK_NBRLCK

     Locks the specified bytes.  If the bytes cannot be locked, *note
     OSError: 2c0. is raised.

 -- Dati: msvcrt.LK_UNLCK

     Unlocks the specified bytes, which must have been previously
     locked.

 -- Funzione: msvcrt.setmode (fd, flags)

     Set the line-end translation mode for the file descriptor 'fd'.  To
     set it to text mode, 'flags' should be *note os.O_TEXT: 3039.; for
     binary, it should be *note os.O_BINARY: 302a.

 -- Funzione: msvcrt.open_osfhandle (handle, flags)

     Create a C runtime file descriptor from the file handle 'handle'.
     The 'flags' parameter should be a bitwise OR of *note os.O_APPEND:
     302c, *note os.O_RDONLY: 3028, *note os.O_TEXT: 3039. and *note
     os.O_NOINHERIT: 3034.  The returned file descriptor may be used as
     a parameter to *note os.fdopen(): 2367. to create a file object.

     The file descriptor is inheritable by default.  Pass *note
     os.O_NOINHERIT: 3034. flag to make it non inheritable.

     Raises an *note auditing event: 1c56. ‘msvcrt.open_osfhandle’ with
     arguments ‘handle’, ‘flags’.

 -- Funzione: msvcrt.get_osfhandle (fd)

     Return the file handle for the file descriptor 'fd'.  Raises *note
     OSError: 2c0. if 'fd' is not recognized.

     Raises an *note auditing event: 1c56. ‘msvcrt.get_osfhandle’ with
     argument ‘fd’.


File: python.info,  Node: Console I/O,  Next: Other Functions,  Prev: File Operations,  Up: msvcrt — Useful routines from the MS VC++ runtime

5.33.1.2 Console I/O
....................

 -- Funzione: msvcrt.kbhit ()

     Returns a nonzero value if a keypress is waiting to be read.
     Otherwise, return 0.

 -- Funzione: msvcrt.getch ()

     Read a keypress and return the resulting character as a byte
     string.  Nothing is echoed to the console.  This call will block if
     a keypress is not already available, but will not wait for ‘Enter’
     to be pressed.  If the pressed key was a special function key, this
     will return ‘'\000'’ or ‘'\xe0'’; the next call will return the
     keycode.  The ‘Control’-‘C’ keypress cannot be read with this
     function.

 -- Funzione: msvcrt.getwch ()

     Wide char variant of *note getch(): 4d26, returning a Unicode
     value.

 -- Funzione: msvcrt.getche ()

     Similar to *note getch(): 4d26, but the keypress will be echoed if
     it represents a printable character.

 -- Funzione: msvcrt.getwche ()

     Wide char variant of *note getche(): 4d27, returning a Unicode
     value.

 -- Funzione: msvcrt.putch (char)

     Print the byte string 'char' to the console without buffering.

 -- Funzione: msvcrt.putwch (unicode_char)

     Wide char variant of *note putch(): 4d28, accepting a Unicode
     value.

 -- Funzione: msvcrt.ungetch (char)

     Cause the byte string 'char' to be «pushed back» into the console
     buffer; it will be the next character read by *note getch(): 4d26.
     or *note getche(): 4d27.

 -- Funzione: msvcrt.ungetwch (unicode_char)

     Wide char variant of *note ungetch(): 4d29, accepting a Unicode
     value.


File: python.info,  Node: Other Functions,  Prev: Console I/O,  Up: msvcrt — Useful routines from the MS VC++ runtime

5.33.1.3 Other Functions
........................

 -- Funzione: msvcrt.heapmin ()

     Force the ‘malloc()’ heap to clean itself up and return unused
     blocks to the operating system.  On failure, this raises *note
     OSError: 2c0.

 -- Funzione: msvcrt.set_error_mode (mode)

     Changes the location where the C runtime writes an error message
     for an error that might end the program.  'mode' must be one of the
     ‘OUT_*’ constants listed below or *note REPORT_ERRMODE: 4d2f.
     Returns the old setting or -1 if an error occurs.  Only available
     in *note debug build of Python: 50a.

 -- Dati: msvcrt.OUT_TO_DEFAULT

     Error sink is determined by the app’s type.  Only available in
     *note debug build of Python: 50a.

 -- Dati: msvcrt.OUT_TO_STDERR

     Error sink is a standard error.  Only available in *note debug
     build of Python: 50a.

 -- Dati: msvcrt.OUT_TO_MSGBOX

     Error sink is a message box.  Only available in *note debug build
     of Python: 50a.

 -- Dati: msvcrt.REPORT_ERRMODE

     Report the current error mode value.  Only available in *note debug
     build of Python: 50a.

 -- Funzione: msvcrt.CrtSetReportMode (type, mode)

     Specifies the destination or destinations for a specific report
     type generated by ‘_CrtDbgReport()’ in the MS VC++ runtime.  'type'
     must be one of the ‘CRT_*’ constants listed below.  'mode' must be
     one of the ‘CRTDBG_*’ constants listed below.  Only available in
     *note debug build of Python: 50a.

 -- Funzione: msvcrt.CrtSetReportFile (type, file)

     After you use *note CrtSetReportMode(): 4d33. to specify *note
     CRTDBG_MODE_FILE: 4d35, you can specify the file handle to receive
     the message text.  'type' must be one of the ‘CRT_*’ constants
     listed below.  'file' should be the file handle your want
     specified.  Only available in *note debug build of Python: 50a.

 -- Dati: msvcrt.CRT_WARN

     Warnings, messages, and information that doesn’t need immediate
     attention.

 -- Dati: msvcrt.CRT_ERROR

     Errors, unrecoverable problems, and issues that require immediate
     attention.

 -- Dati: msvcrt.CRT_ASSERT

     Assertion failures.

 -- Dati: msvcrt.CRTDBG_MODE_DEBUG

     Writes the message to the debugger’s output window.

 -- Dati: msvcrt.CRTDBG_MODE_FILE

     Writes the message to a user-supplied file handle.  *note
     CrtSetReportFile(): 4d34. should be called to define the specific
     file or stream to use as the destination.

 -- Dati: msvcrt.CRTDBG_MODE_WNDW

     Creates a message box to display the message along with the
     ‘Abort’, ‘Retry’, and ‘Ignore’ buttons.

 -- Dati: msvcrt.CRTDBG_REPORT_MODE

     Returns current 'mode' for the specified 'type'.

 -- Dati: msvcrt.CRT_ASSEMBLY_VERSION

     The CRT Assembly version, from the ‘crtassem.h’ header file.

 -- Dati: msvcrt.VC_ASSEMBLY_PUBLICKEYTOKEN

     The VC Assembly public key token, from the ‘crtassem.h’ header
     file.

 -- Dati: msvcrt.LIBRARIES_ASSEMBLY_NAME_PREFIX

     The Libraries Assembly name prefix, from the ‘crtassem.h’ header
     file.


File: python.info,  Node: winreg — Windows registry access,  Next: winsound — Sound-playing interface for Windows,  Prev: msvcrt — Useful routines from the MS VC++ runtime,  Up: MS Windows Specific Services

5.33.2 ‘winreg’ — Windows registry access
-----------------------------------------

__________________________________________________________________

These functions expose the Windows registry API to Python.  Instead of
using an integer as the registry handle, a *note handle object: 4d3f. is
used to ensure that the handles are closed correctly, even if the
programmer neglects to explicitly close them.

*note Availability: 2128.: Windows.

Cambiato nella versione 3.3: Several functions in this module used to
raise a *note WindowsError: 1257, which is now an alias of *note
OSError: 2c0.

* Menu:

* Functions: Functions<13>.
* Constants: Constants<10>.
* Registry Handle Objects::


File: python.info,  Node: Functions<13>,  Next: Constants<10>,  Up: winreg — Windows registry access

5.33.2.1 Functions
..................

This module offers the following functions:

 -- Funzione: winreg.CloseKey (hkey)

     Closes a previously opened registry key.  The 'hkey' argument
     specifies a previously opened key.

          Nota: If 'hkey' is not closed using this method (or via *note
          hkey.Close(): 4d44.), it is closed when the 'hkey' object is
          destroyed by Python.

 -- Funzione: winreg.ConnectRegistry (computer_name, key)

     Establishes a connection to a predefined registry handle on another
     computer, and returns a *note handle object: 4d3f.

     'computer_name' is the name of the remote computer, of the form
     ‘r"\\computername"’.  If ‘None’, the local computer is used.

     'key' is the predefined handle to connect to.

     The return value is the handle of the opened key.  If the function
     fails, an *note OSError: 2c0. exception is raised.

     Raises an *note auditing event: 1c56. ‘winreg.ConnectRegistry’ with
     arguments ‘computer_name’, ‘key’.

     Cambiato nella versione 3.3: See *note above: 4d40.

 -- Funzione: winreg.CreateKey (key, sub_key)

     Creates or opens the specified key, returning a *note handle
     object: 4d3f.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'sub_key' is a string that names the key this method opens or
     creates.

     If 'key' is one of the predefined keys, 'sub_key' may be ‘None’.
     In that case, the handle returned is the same key handle passed in
     to the function.

     If the key already exists, this function opens the existing key.

     The return value is the handle of the opened key.  If the function
     fails, an *note OSError: 2c0. exception is raised.

     Raises an *note auditing event: 1c56. ‘winreg.CreateKey’ with
     arguments ‘key’, ‘sub_key’, ‘access’.

     Raises an *note auditing event: 1c56. ‘winreg.OpenKey/result’ with
     argument ‘key’.

     Cambiato nella versione 3.3: See *note above: 4d40.

 -- Funzione: winreg.CreateKeyEx (key, sub_key, reserved=0,
          access=KEY_WRITE)

     Creates or opens the specified key, returning a *note handle
     object: 4d3f.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'sub_key' is a string that names the key this method opens or
     creates.

     'reserved' is a reserved integer, and must be zero.  The default is
     zero.

     'access' is an integer that specifies an access mask that describes
     the desired security access for the key.  Default is *note
     KEY_WRITE: 4d46.  See *note Access Rights: 4d47. for other allowed
     values.

     If 'key' is one of the predefined keys, 'sub_key' may be ‘None’.
     In that case, the handle returned is the same key handle passed in
     to the function.

     If the key already exists, this function opens the existing key.

     The return value is the handle of the opened key.  If the function
     fails, an *note OSError: 2c0. exception is raised.

     Raises an *note auditing event: 1c56. ‘winreg.CreateKey’ with
     arguments ‘key’, ‘sub_key’, ‘access’.

     Raises an *note auditing event: 1c56. ‘winreg.OpenKey/result’ with
     argument ‘key’.

     Added in version 3.2.

     Cambiato nella versione 3.3: See *note above: 4d40.

 -- Funzione: winreg.DeleteKey (key, sub_key)

     Deletes the specified key.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'sub_key' is a string that must be a subkey of the key identified
     by the 'key' parameter.  This value must not be ‘None’, and the key
     may not have subkeys.

     'This method can not delete keys with subkeys.'

     If the method succeeds, the entire key, including all of its
     values, is removed.  If the method fails, an *note OSError: 2c0.
     exception is raised.

     Raises an *note auditing event: 1c56. ‘winreg.DeleteKey’ with
     arguments ‘key’, ‘sub_key’, ‘access’.

     Cambiato nella versione 3.3: See *note above: 4d40.

 -- Funzione: winreg.DeleteKeyEx (key, sub_key, access=KEY_WOW64_64KEY,
          reserved=0)

     Deletes the specified key.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'sub_key' is a string that must be a subkey of the key identified
     by the 'key' parameter.  This value must not be ‘None’, and the key
     may not have subkeys.

     'reserved' is a reserved integer, and must be zero.  The default is
     zero.

     'access' is an integer that specifies an access mask that describes
     the desired security access for the key.  Default is *note
     KEY_WOW64_64KEY: 4d48.  On 32-bit Windows, the WOW64 constants are
     ignored.  See *note Access Rights: 4d47. for other allowed values.

     'This method can not delete keys with subkeys.'

     If the method succeeds, the entire key, including all of its
     values, is removed.  If the method fails, an *note OSError: 2c0.
     exception is raised.

     On unsupported Windows versions, *note NotImplementedError: 36b. is
     raised.

     Raises an *note auditing event: 1c56. ‘winreg.DeleteKey’ with
     arguments ‘key’, ‘sub_key’, ‘access’.

     Added in version 3.2.

     Cambiato nella versione 3.3: See *note above: 4d40.

 -- Funzione: winreg.DeleteValue (key, value)

     Removes a named value from a registry key.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'value' is a string that identifies the value to remove.

     Raises an *note auditing event: 1c56. ‘winreg.DeleteValue’ with
     arguments ‘key’, ‘value’.

 -- Funzione: winreg.EnumKey (key, index)

     Enumerates subkeys of an open registry key, returning a string.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'index' is an integer that identifies the index of the key to
     retrieve.

     The function retrieves the name of one subkey each time it is
     called.  It is typically called repeatedly until an *note OSError:
     2c0. exception is raised, indicating, no more values are available.

     Raises an *note auditing event: 1c56. ‘winreg.EnumKey’ with
     arguments ‘key’, ‘index’.

     Cambiato nella versione 3.3: See *note above: 4d40.

 -- Funzione: winreg.EnumValue (key, index)

     Enumerates values of an open registry key, returning a tuple.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'index' is an integer that identifies the index of the value to
     retrieve.

     The function retrieves the name of one subkey each time it is
     called.  It is typically called repeatedly, until an *note OSError:
     2c0. exception is raised, indicating no more values.

     The result is a tuple of 3 items:

     Index       Meaning
                 
     -------------------------------------------------------------
                 
     ‘0’         A string that identifies the value name
                 
                 
     ‘1’         An object that holds the value data, and whose
                 type depends on the underlying registry type
                 
                 
     ‘2’         An integer that identifies the type of the
                 value data (see table in docs for
                 *note SetValueEx(): 1aeb.)
                 

     Raises an *note auditing event: 1c56. ‘winreg.EnumValue’ with
     arguments ‘key’, ‘index’.

     Cambiato nella versione 3.3: See *note above: 4d40.

 -- Funzione: winreg.ExpandEnvironmentStrings (str)

     Expands environment variable placeholders ‘%NAME%’ in strings like
     *note REG_EXPAND_SZ: 4d49.:

          >>> ExpandEnvironmentStrings('%windir%')
          'C:\\Windows'

     Raises an *note auditing event: 1c56.
     ‘winreg.ExpandEnvironmentStrings’ with argument ‘str’.

 -- Funzione: winreg.FlushKey (key)

     Writes all the attributes of a key to the registry.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     It is not necessary to call *note FlushKey(): 4d4a. to change a
     key.  Registry changes are flushed to disk by the registry using
     its lazy flusher.  Registry changes are also flushed to disk at
     system shutdown.  Unlike *note CloseKey(): 4d43, the *note
     FlushKey(): 4d4a. method returns only when all the data has been
     written to the registry.  An application should only call *note
     FlushKey(): 4d4a. if it requires absolute certainty that registry
     changes are on disk.

          Nota: If you don’t know whether a *note FlushKey(): 4d4a. call
          is required, it probably isn’t.

 -- Funzione: winreg.LoadKey (key, sub_key, file_name)

     Creates a subkey under the specified key and stores registration
     information from a specified file into that subkey.

     'key' is a handle returned by *note ConnectRegistry(): 474c. or one
     of the constants *note HKEY_USERS: 4d4b. or *note
     HKEY_LOCAL_MACHINE: 4d4c.

     'sub_key' is a string that identifies the subkey to load.

     'file_name' is the name of the file to load registry data from.
     This file must have been created with the *note SaveKey(): 4757.
     function.  Under the file allocation table (FAT) file system, the
     filename may not have an extension.

     A call to *note LoadKey(): 4752. fails if the calling process does
     not have the ‘SE_RESTORE_PRIVILEGE’ privilege.  Note that
     privileges are different from permissions – see the RegLoadKey
     documentation(1) for more details.

     If 'key' is a handle returned by *note ConnectRegistry(): 474c,
     then the path specified in 'file_name' is relative to the remote
     computer.

     Raises an *note auditing event: 1c56. ‘winreg.LoadKey’ with
     arguments ‘key’, ‘sub_key’, ‘file_name’.

 -- Funzione: winreg.OpenKey (key, sub_key, reserved=0, access=KEY_READ)
 -- Funzione: winreg.OpenKeyEx (key, sub_key, reserved=0,
          access=KEY_READ)

     Opens the specified key, returning a *note handle object: 4d3f.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'sub_key' is a string that identifies the sub_key to open.

     'reserved' is a reserved integer, and must be zero.  The default is
     zero.

     'access' is an integer that specifies an access mask that describes
     the desired security access for the key.  Default is *note
     KEY_READ: 4d4e.  See *note Access Rights: 4d47. for other allowed
     values.

     The result is a new handle to the specified key.

     If the function fails, *note OSError: 2c0. is raised.

     Raises an *note auditing event: 1c56. ‘winreg.OpenKey’ with
     arguments ‘key’, ‘sub_key’, ‘access’.

     Raises an *note auditing event: 1c56. ‘winreg.OpenKey/result’ with
     argument ‘key’.

     Cambiato nella versione 3.2: Allow the use of named arguments.

     Cambiato nella versione 3.3: See *note above: 4d40.

 -- Funzione: winreg.QueryInfoKey (key)

     Returns information about a key, as a tuple.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     The result is a tuple of 3 items:

     Index       Meaning
                 
     --------------------------------------------------------------
                 
     ‘0’         An integer giving the number of sub keys this
                 key has.
                 
                 
     ‘1’         An integer giving the number of values this key
                 has.
                 
                 
     ‘2’         An integer giving when the key was last
                 modified (if available) as 100’s of nanoseconds
                 since Jan 1, 1601.
                 

     Raises an *note auditing event: 1c56. ‘winreg.QueryInfoKey’ with
     argument ‘key’.

 -- Funzione: winreg.QueryValue (key, sub_key)

     Retrieves the unnamed value for a key, as a string.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'sub_key' is a string that holds the name of the subkey with which
     the value is associated.  If this parameter is ‘None’ or empty, the
     function retrieves the value set by the *note SetValue(): 4758.
     method for the key identified by 'key'.

     Values in the registry have name, type, and data components.  This
     method retrieves the data for a key’s first value that has a ‘NULL’
     name.  But the underlying API call doesn’t return the type, so
     always use *note QueryValueEx(): 176b. if possible.

     Raises an *note auditing event: 1c56. ‘winreg.QueryValue’ with
     arguments ‘key’, ‘sub_key’, ‘value_name’.

 -- Funzione: winreg.QueryValueEx (key, value_name)

     Retrieves the type and data for a specified value name associated
     with an open registry key.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'value_name' is a string indicating the value to query.

     The result is a tuple of 2 items:

     Index       Meaning
                 
     ----------------------------------------------------------
                 
     ‘0’         The value of the registry item.
                 
                 
     ‘1’         An integer giving the registry type for
                 this value (see table in docs for
                 *note SetValueEx(): 1aeb.)
                 

     Raises an *note auditing event: 1c56. ‘winreg.QueryValue’ with
     arguments ‘key’, ‘sub_key’, ‘value_name’.

 -- Funzione: winreg.SaveKey (key, file_name)

     Saves the specified key, and all its subkeys to the specified file.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'file_name' is the name of the file to save registry data to.  This
     file cannot already exist.  If this filename includes an extension,
     it cannot be used on file allocation table (FAT) file systems by
     the *note LoadKey(): 4752. method.

     If 'key' represents a key on a remote computer, the path described
     by 'file_name' is relative to the remote computer.  The caller of
     this method must possess the 'SeBackupPrivilege' security
     privilege.  Note that privileges are different than permissions –
     see the Conflicts Between User Rights and Permissions
     documentation(2) for more details.

     This function passes ‘NULL’ for 'security_attributes' to the API.

     Raises an *note auditing event: 1c56. ‘winreg.SaveKey’ with
     arguments ‘key’, ‘file_name’.

 -- Funzione: winreg.SetValue (key, sub_key, type, value)

     Associates a value with a specified key.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'sub_key' is a string that names the subkey with which the value is
     associated.

     'type' is an integer that specifies the type of the data.
     Currently this must be *note REG_SZ: 4d4f, meaning only strings are
     supported.  Use the *note SetValueEx(): 1aeb. function for support
     for other data types.

     'value' is a string that specifies the new value.

     If the key specified by the 'sub_key' parameter does not exist, the
     SetValue function creates it.

     Value lengths are limited by available memory.  Long values (more
     than 2048 bytes) should be stored as files with the filenames
     stored in the configuration registry.  This helps the registry
     perform efficiently.

     The key identified by the 'key' parameter must have been opened
     with *note KEY_SET_VALUE: 4d50. access.

     Raises an *note auditing event: 1c56. ‘winreg.SetValue’ with
     arguments ‘key’, ‘sub_key’, ‘type’, ‘value’.

 -- Funzione: winreg.SetValueEx (key, value_name, reserved, type, value)

     Stores data in the value field of an open registry key.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     'value_name' is a string that names the subkey with which the value
     is associated.

     'reserved' can be anything – zero is always passed to the API.

     'type' is an integer that specifies the type of the data.  See
     *note Value Types: 4d51. for the available types.

     'value' is a string that specifies the new value.

     This method can also set additional value and type information for
     the specified key.  The key identified by the key parameter must
     have been opened with *note KEY_SET_VALUE: 4d50. access.

     To open the key, use the *note CreateKey(): 474d. or *note
     OpenKey(): 4753. methods.

     Value lengths are limited by available memory.  Long values (more
     than 2048 bytes) should be stored as files with the filenames
     stored in the configuration registry.  This helps the registry
     perform efficiently.

     Raises an *note auditing event: 1c56. ‘winreg.SetValue’ with
     arguments ‘key’, ‘sub_key’, ‘type’, ‘value’.

 -- Funzione: winreg.DisableReflectionKey (key)

     Disables registry reflection for 32-bit processes running on a
     64-bit operating system.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     Will generally raise *note NotImplementedError: 36b. if executed on
     a 32-bit operating system.

     If the key is not on the reflection list, the function succeeds but
     has no effect.  Disabling reflection for a key does not affect
     reflection of any subkeys.

     Raises an *note auditing event: 1c56. ‘winreg.DisableReflectionKey’
     with argument ‘key’.

 -- Funzione: winreg.EnableReflectionKey (key)

     Restores registry reflection for the specified disabled key.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     Will generally raise *note NotImplementedError: 36b. if executed on
     a 32-bit operating system.

     Restoring reflection for a key does not affect reflection of any
     subkeys.

     Raises an *note auditing event: 1c56. ‘winreg.EnableReflectionKey’
     with argument ‘key’.

 -- Funzione: winreg.QueryReflectionKey (key)

     Determines the reflection state for the specified key.

     'key' is an already open key, or one of the predefined *note HKEY_*
     constants: 4d45.

     Returns ‘True’ if reflection is disabled.

     Will generally raise *note NotImplementedError: 36b. if executed on
     a 32-bit operating system.

     Raises an *note auditing event: 1c56. ‘winreg.QueryReflectionKey’
     with argument ‘key’.

   ---------- Footnotes ----------

   (1) 
https://msdn.microsoft.com/en-us/library/ms724889%28v=VS.85%29.aspx

   (2) 
https://msdn.microsoft.com/en-us/library/ms724878%28v=VS.85%29.aspx


File: python.info,  Node: Constants<10>,  Next: Registry Handle Objects,  Prev: Functions<13>,  Up: winreg — Windows registry access

5.33.2.2 Constants
..................

The following constants are defined for use in many *note winreg: 11c.
functions.

* Menu:

* HKEY_* Constants::
* Access Rights::
* Value Types::


File: python.info,  Node: HKEY_* Constants,  Next: Access Rights,  Up: Constants<10>

5.33.2.3 HKEY_* Constants
.........................

 -- Dati: winreg.HKEY_CLASSES_ROOT

     Registry entries subordinate to this key define types (or classes)
     of documents and the properties associated with those types.  Shell
     and COM applications use the information stored under this key.

 -- Dati: winreg.HKEY_CURRENT_USER

     Registry entries subordinate to this key define the preferences of
     the current user.  These preferences include the settings of
     environment variables, data about program groups, colors, printers,
     network connections, and application preferences.

 -- Dati: winreg.HKEY_LOCAL_MACHINE

     Registry entries subordinate to this key define the physical state
     of the computer, including data about the bus type, system memory,
     and installed hardware and software.

 -- Dati: winreg.HKEY_USERS

     Registry entries subordinate to this key define the default user
     configuration for new users on the local computer and the user
     configuration for the current user.

 -- Dati: winreg.HKEY_PERFORMANCE_DATA

     Registry entries subordinate to this key allow you to access
     performance data.  The data is not actually stored in the registry;
     the registry functions cause the system to collect the data from
     its source.

 -- Dati: winreg.HKEY_CURRENT_CONFIG

     Contains information about the current hardware profile of the
     local computer system.

 -- Dati: winreg.HKEY_DYN_DATA

     This key is not used in versions of Windows after 98.


File: python.info,  Node: Access Rights,  Next: Value Types,  Prev: HKEY_* Constants,  Up: Constants<10>

5.33.2.4 Access Rights
......................

For more information, see Registry Key Security and Access(1).

 -- Dati: winreg.KEY_ALL_ACCESS

     Combines the STANDARD_RIGHTS_REQUIRED, *note KEY_QUERY_VALUE: 4d5c,
     *note KEY_SET_VALUE: 4d50, *note KEY_CREATE_SUB_KEY: 4d5d, *note
     KEY_ENUMERATE_SUB_KEYS: 4d5e, *note KEY_NOTIFY: 4d5f, and *note
     KEY_CREATE_LINK: 4d60. access rights.

 -- Dati: winreg.KEY_WRITE

     Combines the STANDARD_RIGHTS_WRITE, *note KEY_SET_VALUE: 4d50, and
     *note KEY_CREATE_SUB_KEY: 4d5d. access rights.

 -- Dati: winreg.KEY_READ

     Combines the STANDARD_RIGHTS_READ, *note KEY_QUERY_VALUE: 4d5c,
     *note KEY_ENUMERATE_SUB_KEYS: 4d5e, and *note KEY_NOTIFY: 4d5f.
     values.

 -- Dati: winreg.KEY_EXECUTE

     Equivalent to *note KEY_READ: 4d4e.

 -- Dati: winreg.KEY_QUERY_VALUE

     Required to query the values of a registry key.

 -- Dati: winreg.KEY_SET_VALUE

     Required to create, delete, or set a registry value.

 -- Dati: winreg.KEY_CREATE_SUB_KEY

     Required to create a subkey of a registry key.

 -- Dati: winreg.KEY_ENUMERATE_SUB_KEYS

     Required to enumerate the subkeys of a registry key.

 -- Dati: winreg.KEY_NOTIFY

     Required to request change notifications for a registry key or for
     subkeys of a registry key.

 -- Dati: winreg.KEY_CREATE_LINK

     Reserved for system use.

* Menu:

* 64-bit Specific::

   ---------- Footnotes ----------

   (1) 
https://msdn.microsoft.com/en-us/library/ms724878%28v=VS.85%29.aspx


File: python.info,  Node: 64-bit Specific,  Up: Access Rights

5.33.2.5 64-bit Specific
........................

For more information, see Accessing an Alternate Registry View(1).

 -- Dati: winreg.KEY_WOW64_64KEY

     Indicates that an application on 64-bit Windows should operate on
     the 64-bit registry view.  On 32-bit Windows, this constant is
     ignored.

 -- Dati: winreg.KEY_WOW64_32KEY

     Indicates that an application on 64-bit Windows should operate on
     the 32-bit registry view.  On 32-bit Windows, this constant is
     ignored.

   ---------- Footnotes ----------

   (1) https://msdn.microsoft.com/en-us/library/aa384129(v=VS.85).aspx


File: python.info,  Node: Value Types,  Prev: Access Rights,  Up: Constants<10>

5.33.2.6 Value Types
....................

For more information, see Registry Value Types(1).

 -- Dati: winreg.REG_BINARY

     Binary data in any form.

 -- Dati: winreg.REG_DWORD

     32-bit number.

 -- Dati: winreg.REG_DWORD_LITTLE_ENDIAN

     A 32-bit number in little-endian format.  Equivalent to *note
     REG_DWORD: 4d67.

 -- Dati: winreg.REG_DWORD_BIG_ENDIAN

     A 32-bit number in big-endian format.

 -- Dati: winreg.REG_EXPAND_SZ

     Null-terminated string containing references to environment
     variables (‘%PATH%’).

 -- Dati: winreg.REG_LINK

     A Unicode symbolic link.

 -- Dati: winreg.REG_MULTI_SZ

     A sequence of null-terminated strings, terminated by two null
     characters.  (Python handles this termination automatically.)

 -- Dati: winreg.REG_NONE

     No defined value type.

 -- Dati: winreg.REG_QWORD

     A 64-bit number.

     Added in version 3.6.

 -- Dati: winreg.REG_QWORD_LITTLE_ENDIAN

     A 64-bit number in little-endian format.  Equivalent to *note
     REG_QWORD: f01.

     Added in version 3.6.

 -- Dati: winreg.REG_RESOURCE_LIST

     A device-driver resource list.

 -- Dati: winreg.REG_FULL_RESOURCE_DESCRIPTOR

     A hardware setting.

 -- Dati: winreg.REG_RESOURCE_REQUIREMENTS_LIST

     A hardware resource list.

 -- Dati: winreg.REG_SZ

     A null-terminated string.

   ---------- Footnotes ----------

   (1) 
https://msdn.microsoft.com/en-us/library/ms724884%28v=VS.85%29.aspx


File: python.info,  Node: Registry Handle Objects,  Prev: Constants<10>,  Up: winreg — Windows registry access

5.33.2.7 Registry Handle Objects
................................

This object wraps a Windows HKEY object, automatically closing it when
the object is destroyed.  To guarantee cleanup, you can call either the
*note Close(): 4d44. method on the object, or the *note CloseKey():
4d43. function.

All registry functions in this module return one of these objects.

All registry functions in this module which accept a handle object also
accept an integer, however, use of the handle object is encouraged.

Handle objects provide semantics for *note __bool__(): 14dd. – thus

     if handle:
         print("Yes")

will print ‘Yes’ if the handle is currently valid (has not been closed
or detached).

Handle objects can be converted to an integer (e.g., using the built-in
*note int(): 19b. function), in which case the underlying Windows handle
value is returned.  You can also use the *note Detach(): 4754. method to
return the integer handle, and also disconnect the Windows handle from
the handle object.

 -- Metodo: PyHKEY.Close ()

     Closes the underlying Windows handle.

     If the handle is already closed, no error is raised.

 -- Metodo: PyHKEY.Detach ()

     Detaches the Windows handle from the handle object.

     The result is an integer that holds the value of the handle before
     it is detached.  If the handle is already detached or closed, this
     will return zero.

     After calling this function, the handle is effectively invalidated,
     but the handle is not closed.  You would call this function when
     you need the underlying Win32 handle to exist beyond the lifetime
     of the handle object.

     Raises an *note auditing event: 1c56. ‘winreg.PyHKEY.Detach’ with
     argument ‘key’.

 -- Metodo: PyHKEY.__enter__ ()
 -- Metodo: PyHKEY.__exit__ (*exc_info)

     The HKEY object implements *note __enter__(): 7e5. and *note
     __exit__(): 1508. and thus supports the context protocol for the
     *note with: 186. statement:

          with OpenKey(HKEY_LOCAL_MACHINE, "foo") as key:
              ...  # work with key

     will automatically close 'key' when control leaves the *note with:
     186. block.


File: python.info,  Node: winsound — Sound-playing interface for Windows,  Prev: winreg — Windows registry access,  Up: MS Windows Specific Services

5.33.3 ‘winsound’ — Sound-playing interface for Windows
-------------------------------------------------------

__________________________________________________________________

The *note winsound: 11d. module provides access to the basic
sound-playing machinery provided by Windows platforms.  It includes
functions and several constants.

*note Availability: 2128.: Windows.

 -- Funzione: winsound.Beep (frequency, duration)

     Beep the PC’s speaker.  The 'frequency' parameter specifies
     frequency, in hertz, of the sound, and must be in the range 37
     through 32,767.  The 'duration' parameter specifies the number of
     milliseconds the sound should last.  If the system is not able to
     beep the speaker, *note RuntimeError: 244. is raised.

 -- Funzione: winsound.PlaySound (sound, flags)

     Call the underlying ‘PlaySound()’ function from the Platform API.
     The 'sound' parameter may be a filename, a system sound alias,
     audio data as a *note bytes-like object: 193, or ‘None’.  Its
     interpretation depends on the value of 'flags', which can be a
     bitwise ORed combination of the constants described below.  If the
     'sound' parameter is ‘None’, any currently playing waveform sound
     is stopped.  If the system indicates an error, *note RuntimeError:
     244. is raised.

 -- Funzione: winsound.MessageBeep (type=MB_OK)

     Call the underlying ‘MessageBeep()’ function from the Platform API.
     This plays a sound as specified in the registry.  The 'type'
     argument specifies which sound to play; possible values are ‘-1’,
     ‘MB_ICONASTERISK’, ‘MB_ICONEXCLAMATION’, ‘MB_ICONHAND’,
     ‘MB_ICONQUESTION’, and ‘MB_OK’, all described below.  The value
     ‘-1’ produces a «simple beep»; this is the final fallback if a
     sound cannot be played otherwise.  If the system indicates an
     error, *note RuntimeError: 244. is raised.

 -- Dati: winsound.SND_FILENAME

     The 'sound' parameter is the name of a WAV file.  Do not use with
     *note SND_ALIAS: 4d77.

 -- Dati: winsound.SND_ALIAS

     The 'sound' parameter is a sound association name from the
     registry.  If the registry contains no such name, play the system
     default sound unless *note SND_NODEFAULT: 4d78. is also specified.
     If no default sound is registered, raise *note RuntimeError: 244.
     Do not use with *note SND_FILENAME: 4d76.

     All Win32 systems support at least the following; most systems
     support many more:

     *note PlaySound(): f05.        Corresponding Control Panel Sound name
     'name'                         

     ----------------------------------------------------------------------------
                                    
     ‘'SystemAsterisk'’             Asterisk
                                    
                                    
     ‘'SystemExclamation'’          Exclamation
                                    
                                    
     ‘'SystemExit'’                 Exit Windows
                                    
                                    
     ‘'SystemHand'’                 Critical Stop
                                    
                                    
     ‘'SystemQuestion'’             Question
                                    

     For example:

          import winsound
          # Play Windows exit sound.
          winsound.PlaySound("SystemExit", winsound.SND_ALIAS)

          # Probably play Windows default sound, if any is registered (because
          # "*" probably isn't the registered name of any sound).
          winsound.PlaySound("*", winsound.SND_ALIAS)

 -- Dati: winsound.SND_LOOP

     Play the sound repeatedly.  The *note SND_ASYNC: 4d7a. flag must
     also be used to avoid blocking.  Cannot be used with *note
     SND_MEMORY: 4d7b.

 -- Dati: winsound.SND_MEMORY

     The 'sound' parameter to *note PlaySound(): f05. is a memory image
     of a WAV file, as a *note bytes-like object: 193.

          Nota: This module does not support playing from a memory image
          asynchronously, so a combination of this flag and *note
          SND_ASYNC: 4d7a. will raise *note RuntimeError: 244.

 -- Dati: winsound.SND_PURGE

     Stop playing all instances of the specified sound.

          Nota: This flag is not supported on modern Windows platforms.

 -- Dati: winsound.SND_ASYNC

     Return immediately, allowing sounds to play asynchronously.

 -- Dati: winsound.SND_NODEFAULT

     If the specified sound cannot be found, do not play the system
     default sound.

 -- Dati: winsound.SND_NOSTOP

     Do not interrupt sounds currently playing.

 -- Dati: winsound.SND_NOWAIT

     Return immediately if the sound driver is busy.

          Nota: This flag is not supported on modern Windows platforms.

 -- Dati: winsound.SND_APPLICATION

     The 'sound' parameter is an application-specific alias in the
     registry.  This flag can be combined with the *note SND_ALIAS:
     4d77. flag to specify an application-defined sound alias.

 -- Dati: winsound.SND_SENTRY

     Triggers a SoundSentry event when the sound is played.

     Added in version 3.14.

 -- Dati: winsound.SND_SYNC

     The sound is played synchronously.  This is the default behavior.

     Added in version 3.14.

 -- Dati: winsound.SND_SYSTEM

     Assign the sound to the audio session for system notification
     sounds.

     Added in version 3.14.

 -- Dati: winsound.MB_ICONASTERISK

     Play the ‘SystemDefault’ sound.

 -- Dati: winsound.MB_ICONEXCLAMATION

     Play the ‘SystemExclamation’ sound.

 -- Dati: winsound.MB_ICONHAND

     Play the ‘SystemHand’ sound.

 -- Dati: winsound.MB_ICONQUESTION

     Play the ‘SystemQuestion’ sound.

 -- Dati: winsound.MB_OK

     Play the ‘SystemDefault’ sound.

 -- Dati: winsound.MB_ICONERROR

     Play the ‘SystemHand’ sound.

     Added in version 3.14.

 -- Dati: winsound.MB_ICONINFORMATION

     Play the ‘SystemDefault’ sound.

     Added in version 3.14.

 -- Dati: winsound.MB_ICONSTOP

     Play the ‘SystemHand’ sound.

     Added in version 3.14.

 -- Dati: winsound.MB_ICONWARNING

     Play the ‘SystemExclamation’ sound.

     Added in version 3.14.


File: python.info,  Node: Unix-specific services,  Next: Modules command-line interface CLI,  Prev: MS Windows Specific Services,  Up: The Python Standard Library

5.34 Unix-specific services
===========================

The modules described in this chapter provide interfaces to features
that are unique to the Unix operating system, or in some cases to some
or many variants of it.  Here’s an overview:

* Menu:

* shlex — Simple lexical analysis::
* posix — The most common POSIX system calls::
* pwd — The password database::
* grp — The group database::
* termios — POSIX style tty control::
* tty — Terminal control functions::
* pty — Pseudo-terminal utilities::
* fcntl — The fcntl and ioctl system calls::
* resource — Resource usage information::
* syslog — Unix syslog library routines::


File: python.info,  Node: shlex — Simple lexical analysis,  Next: posix — The most common POSIX system calls,  Up: Unix-specific services

5.34.1 ‘shlex’ — Simple lexical analysis
----------------------------------------

'Source code:' Lib/shlex.py(1)

__________________________________________________________________

The *note shlex: eca. class makes it easy to write lexical analyzers for
simple syntaxes resembling that of the Unix shell.  This will often be
useful for writing minilanguages, (for example, in run control files for
Python applications) or for parsing quoted strings.

The *note shlex: c9. module defines the following functions:

 -- Funzione: shlex.split (s, comments=False, posix=True)

     Split the string 's' using shell-like syntax.  If 'comments' is
     *note False: d2d. (the default), the parsing of comments in the
     given string will be disabled (setting the *note commenters: 4d92.
     attribute of the *note shlex: eca. instance to the empty string).
     This function operates in POSIX mode by default, but uses non-POSIX
     mode if the 'posix' argument is false.

     Cambiato nella versione 3.12: Passing ‘None’ for 's' argument now
     raises an exception, rather than reading *note sys.stdin: 760.

 -- Funzione: shlex.join (split_command)

     Concatenate the tokens of the list 'split_command' and return a
     string.  This function is the inverse of *note split(): 75f.

          >>> from shlex import join
          >>> print(join(['echo', '-n', 'Multiple words']))
          echo -n 'Multiple words'

     The returned value is shell-escaped to protect against injection
     vulnerabilities (see *note quote(): 582.).

     Added in version 3.8.

 -- Funzione: shlex.quote (s)

     Return a shell-escaped version of the string 's'.  The returned
     value is a string that can safely be used as one token in a shell
     command line, for cases where you cannot use a list.
          Avvertimento: The ‘shlex’ module is 'only designed for Unix
          shells'.

          The *note quote(): 582. function is not guaranteed to be
          correct on non-POSIX compliant shells or shells from other
          operating systems such as Windows.  Executing commands quoted
          by this module on such shells can open up the possibility of a
          command injection vulnerability.

          Consider using functions that pass command arguments with
          lists such as *note subprocess.run(): d81. with ‘shell=False’.

     This idiom would be unsafe:

          >>> filename = 'somefile; rm -rf ~'
          >>> command = 'ls -l {}'.format(filename)
          >>> print(command)  # executed by a shell: boom!
          ls -l somefile; rm -rf ~

     *note quote(): 582. lets you plug the security hole:

          >>> from shlex import quote
          >>> command = 'ls -l {}'.format(quote(filename))
          >>> print(command)
          ls -l 'somefile; rm -rf ~'
          >>> remote_command = 'ssh home {}'.format(quote(command))
          >>> print(remote_command)
          ssh home 'ls -l '"'"'somefile; rm -rf ~'"'"''

     The quoting is compatible with UNIX shells and with *note split():
     75f.:

          >>> from shlex import split
          >>> remote_command = split(remote_command)
          >>> remote_command
          ['ssh', 'home', "ls -l 'somefile; rm -rf ~'"]
          >>> command = split(remote_command[-1])
          >>> command
          ['ls', '-l', 'somefile; rm -rf ~']

     Added in version 3.3.

The *note shlex: c9. module defines the following class:

 -- Classe: shlex.shlex (instream=None, infile=None, posix=False,
          punctuation_chars=False)

     A *note shlex: eca. instance or subclass instance is a lexical
     analyzer object.  The initialization argument, if present,
     specifies where to read characters from.  It must be a
     file-/stream-like object with *note read(): 2056. and *note
     readline(): 2090. methods, or a string.  If no argument is given,
     input will be taken from ‘sys.stdin’.  The second optional argument
     is a filename string, which sets the initial value of the *note
     infile: 4d93. attribute.  If the 'instream' argument is omitted or
     equal to ‘sys.stdin’, this second argument defaults to «stdin».
     The 'posix' argument defines the operational mode: when 'posix' is
     not true (default), the *note shlex: eca. instance will operate in
     compatibility mode.  When operating in POSIX mode, *note shlex:
     eca. will try to be as close as possible to the POSIX shell parsing
     rules.  The 'punctuation_chars' argument provides a way to make the
     behaviour even closer to how real shells parse.  This can take a
     number of values: the default value, ‘False’, preserves the
     behaviour seen under Python 3.5 and earlier.  If set to ‘True’,
     then parsing of the characters ‘();<>|&’ is changed: any run of
     these characters (considered punctuation characters) is returned as
     a single token.  If set to a non-empty string of characters, those
     characters will be used as the punctuation characters.  Any
     characters in the *note wordchars: 4d94. attribute that appear in
     'punctuation_chars' will be removed from *note wordchars: 4d94.
     See *note Improved Compatibility with Shells: ecb. for more
     information.  'punctuation_chars' can be set only upon *note shlex:
     eca. instance creation and can’t be modified later.

     Cambiato nella versione 3.6: The 'punctuation_chars' parameter was
     added.

Vedi anche
..........

Module *note configparser: 26.

     Parser for configuration files similar to the Windows ‘.ini’ files.

* Menu:

* shlex Objects::
* Parsing Rules::
* Improved Compatibility with Shells::

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/shlex.py


File: python.info,  Node: shlex Objects,  Next: Parsing Rules,  Up: shlex — Simple lexical analysis

5.34.1.1 shlex Objects
......................

A *note shlex: eca. instance has the following methods:

 -- Metodo: shlex.get_token ()

     Return a token.  If tokens have been stacked using *note
     push_token(): 4d98, pop a token off the stack.  Otherwise, read one
     from the input stream.  If reading encounters an immediate
     end-of-file, *note eof: 4d99. is returned (the empty string (‘''’)
     in non-POSIX mode, and ‘None’ in POSIX mode).

 -- Metodo: shlex.push_token (str)

     Push the argument onto the token stack.

 -- Metodo: shlex.read_token ()

     Read a raw token.  Ignore the pushback stack, and do not interpret
     source requests.  (This is not ordinarily a useful entry point, and
     is documented here only for the sake of completeness.)

 -- Metodo: shlex.sourcehook (filename)

     When *note shlex: eca. detects a source request (see *note source:
     4d9c. below) this method is given the following token as argument,
     and expected to return a tuple consisting of a filename and an open
     file-like object.

     Normally, this method first strips any quotes off the argument.  If
     the result is an absolute pathname, or there was no previous source
     request in effect, or the previous source was a stream (such as
     ‘sys.stdin’), the result is left alone.  Otherwise, if the result
     is a relative pathname, the directory part of the name of the file
     immediately before it on the source inclusion stack is prepended
     (this behavior is like the way the C preprocessor handles ‘#include
     "file.h"’).

     The result of the manipulations is treated as a filename, and
     returned as the first component of the tuple, with *note open():
     316. called on it to yield the second component.  (Note: this is
     the reverse of the order of arguments in instance initialization!)

     This hook is exposed so that you can use it to implement directory
     search paths, addition of file extensions, and other namespace
     hacks.  There is no corresponding “close” hook, but a shlex
     instance will call the *note close(): 507. method of the sourced
     input stream when it returns EOF.

     For more explicit control of source stacking, use the *note
     push_source(): 4d9d. and *note pop_source(): 4d9e. methods.

 -- Metodo: shlex.push_source (newstream, newfile=None)

     Push an input source stream onto the input stack.  If the filename
     argument is specified it will later be available for use in error
     messages.  This is the same method used internally by the *note
     sourcehook(): 4d9b. method.

 -- Metodo: shlex.pop_source ()

     Pop the last-pushed input source from the input stack.  This is the
     same method used internally when the lexer reaches EOF on a stacked
     input stream.

 -- Metodo: shlex.error_leader (infile=None, lineno=None)

     This method generates an error message leader in the format of a
     Unix C compiler error label; the format is ‘'"%s", line %d: '’,
     where the ‘%s’ is replaced with the name of the current source file
     and the ‘%d’ with the current input line number (the optional
     arguments can be used to override these).

     This convenience is provided to encourage *note shlex: c9. users to
     generate error messages in the standard, parseable format
     understood by Emacs and other Unix tools.

Instances of *note shlex: eca. subclasses have some public instance
variables which either control lexical analysis or can be used for
debugging:

 -- Attributo: shlex.commenters

     The string of characters that are recognized as comment beginners.
     All characters from the comment beginner to end of line are
     ignored.  Includes just ‘'#'’ by default.

 -- Attributo: shlex.wordchars

     The string of characters that will accumulate into multi-character
     tokens.  By default, includes all ASCII alphanumerics and
     underscore.  In POSIX mode, the accented characters in the Latin-1
     set are also included.  If *note punctuation_chars: 1d9e. is not
     empty, the characters ‘~-./*?=’, which can appear in filename
     specifications and command line parameters, will also be included
     in this attribute, and any characters which appear in
     ‘punctuation_chars’ will be removed from ‘wordchars’ if they are
     present there.  If *note whitespace_split: 4da0. is set to ‘True’,
     this will have no effect.

 -- Attributo: shlex.whitespace

     Characters that will be considered whitespace and skipped.
     Whitespace bounds tokens.  By default, includes space, tab,
     linefeed and carriage-return.

 -- Attributo: shlex.escape

     Characters that will be considered as escape.  This will be only
     used in POSIX mode, and includes just ‘'\'’ by default.

 -- Attributo: shlex.quotes

     Characters that will be considered string quotes.  The token
     accumulates until the same quote is encountered again (thus,
     different quote types protect each other as in the shell.)  By
     default, includes ASCII single and double quotes.

 -- Attributo: shlex.escapedquotes

     Characters in *note quotes: 4da3. that will interpret escape
     characters defined in *note escape: 4da2.  This is only used in
     POSIX mode, and includes just ‘'"'’ by default.

 -- Attributo: shlex.whitespace_split

     If ‘True’, tokens will only be split in whitespaces.  This is
     useful, for example, for parsing command lines with *note shlex:
     eca, getting tokens in a similar way to shell arguments.  When used
     in combination with *note punctuation_chars: 1d9e, tokens will be
     split on whitespace in addition to those characters.

     Cambiato nella versione 3.8: The *note punctuation_chars: 1d9e.
     attribute was made compatible with the *note whitespace_split:
     4da0. attribute.

 -- Attributo: shlex.infile

     The name of the current input file, as initially set at class
     instantiation time or stacked by later source requests.  It may be
     useful to examine this when constructing error messages.

 -- Attributo: shlex.instream

     The input stream from which this *note shlex: eca. instance is
     reading characters.

 -- Attributo: shlex.source

     This attribute is ‘None’ by default.  If you assign a string to it,
     that string will be recognized as a lexical-level inclusion request
     similar to the ‘source’ keyword in various shells.  That is, the
     immediately following token will be opened as a filename and input
     will be taken from that stream until EOF, at which point the *note
     close(): 507. method of that stream will be called and the input
     source will again become the original input stream.  Source
     requests may be stacked any number of levels deep.

 -- Attributo: shlex.debug

     If this attribute is numeric and ‘1’ or more, a *note shlex: eca.
     instance will print verbose progress output on its behavior.  If
     you need to use this, you can read the module source code to learn
     the details.

 -- Attributo: shlex.lineno

     Source line number (count of newlines seen so far plus one).

 -- Attributo: shlex.token

     The token buffer.  It may be useful to examine this when catching
     exceptions.

 -- Attributo: shlex.eof

     Token used to determine end of file.  This will be set to the empty
     string (‘''’), in non-POSIX mode, and to ‘None’ in POSIX mode.

 -- Attributo: shlex.punctuation_chars

     A read-only property.  Characters that will be considered
     punctuation.  Runs of punctuation characters will be returned as a
     single token.  However, note that no semantic validity checking
     will be performed: for example, “>>>” could be returned as a token,
     even though it may not be recognised as such by shells.

     Added in version 3.6.


File: python.info,  Node: Parsing Rules,  Next: Improved Compatibility with Shells,  Prev: shlex Objects,  Up: shlex — Simple lexical analysis

5.34.1.2 Parsing Rules
......................

When operating in non-POSIX mode, *note shlex: eca. will try to obey to
the following rules.

   * Quote characters are not recognized within words (‘Do"Not"Separate’
     is parsed as the single word ‘Do"Not"Separate’);

   * Escape characters are not recognized;

   * Enclosing characters in quotes preserve the literal value of all
     characters within the quotes;

   * Closing quotes separate words (‘"Do"Separate’ is parsed as ‘"Do"’
     and ‘Separate’);

   * If *note whitespace_split: 4da0. is ‘False’, any character not
     declared to be a word character, whitespace, or a quote will be
     returned as a single-character token.  If it is ‘True’, *note
     shlex: eca. will only split words in whitespaces;

   * EOF is signaled with an empty string (‘''’);

   * It’s not possible to parse empty strings, even if quoted.

When operating in POSIX mode, *note shlex: eca. will try to obey to the
following parsing rules.

   * Quotes are stripped out, and do not separate words
     (‘"Do"Not"Separate"’ is parsed as the single word ‘DoNotSeparate’);

   * Non-quoted escape characters (e.g.  ‘'\'’) preserve the literal
     value of the next character that follows;

   * Enclosing characters in quotes which are not part of *note
     escapedquotes: 4da4. (e.g.  ‘"'"’)  preserve the literal value of
     all characters within the quotes;

   * Enclosing characters in quotes which are part of *note
     escapedquotes: 4da4. (e.g.  ‘'"'’)  preserves the literal value of
     all characters within the quotes, with the exception of the
     characters mentioned in *note escape: 4da2.  The escape characters
     retain its special meaning only when followed by the quote in use,
     or the escape character itself.  Otherwise the escape character
     will be considered a normal character.

   * EOF is signaled with a *note None: 886. value;

   * Quoted empty strings (‘''’) are allowed.


File: python.info,  Node: Improved Compatibility with Shells,  Prev: Parsing Rules,  Up: shlex — Simple lexical analysis

5.34.1.3 Improved Compatibility with Shells
...........................................

Added in version 3.6.

The *note shlex: c9. class provides compatibility with the parsing
performed by common Unix shells like ‘bash’, ‘dash’, and ‘sh’.  To take
advantage of this compatibility, specify the ‘punctuation_chars’
argument in the constructor.  This defaults to ‘False’, which preserves
pre-3.6 behaviour.  However, if it is set to ‘True’, then parsing of the
characters ‘();<>|&’ is changed: any run of these characters is returned
as a single token.  While this is short of a full parser for shells
(which would be out of scope for the standard library, given the
multiplicity of shells out there), it does allow you to perform
processing of command lines more easily than you could otherwise.  To
illustrate, you can see the difference in the following snippet:

     >>> import shlex
     >>> text = "a && b; c && d || e; f >'abc'; (def \"ghi\")"
     >>> s = shlex.shlex(text, posix=True)
     >>> s.whitespace_split = True
     >>> list(s)
     ['a', '&&', 'b;', 'c', '&&', 'd', '||', 'e;', 'f', '>abc;', '(def', 'ghi)']
     >>> s = shlex.shlex(text, posix=True, punctuation_chars=True)
     >>> s.whitespace_split = True
     >>> list(s)
     ['a', '&&', 'b', ';', 'c', '&&', 'd', '||', 'e', ';', 'f', '>', 'abc', ';',
     '(', 'def', 'ghi', ')']

Of course, tokens will be returned which are not valid for shells, and
you’ll need to implement your own error checks on the returned tokens.

Instead of passing ‘True’ as the value for the punctuation_chars
parameter, you can pass a string with specific characters, which will be
used to determine which characters constitute punctuation.  For example:

     >>> import shlex
     >>> s = shlex.shlex("a && b || c", punctuation_chars="|")
     >>> list(s)
     ['a', '&', '&', 'b', '||', 'c']

     Nota: When ‘punctuation_chars’ is specified, the *note wordchars:
     4d94. attribute is augmented with the characters ‘~-./*?=’.  That
     is because these characters can appear in file names (including
     wildcards) and command-line arguments (e.g.  ‘--color=auto’).
     Hence:

          >>> import shlex
          >>> s = shlex.shlex('~/a && b-c --color=auto || d *.py?',
          ...                 punctuation_chars=True)
          >>> list(s)
          ['~/a', '&&', 'b-c', '--color=auto', '||', 'd', '*.py?']

     However, to match the shell as closely as possible, it is
     recommended to always use ‘posix’ and *note whitespace_split: 4da0.
     when using *note punctuation_chars: 1d9e, which will negate *note
     wordchars: 4d94. entirely.

For best effect, ‘punctuation_chars’ should be set in conjunction with
‘posix=True’.  (Note that ‘posix=False’ is the default for *note shlex:
eca.)


File: python.info,  Node: posix — The most common POSIX system calls,  Next: pwd — The password database,  Prev: shlex — Simple lexical analysis,  Up: Unix-specific services

5.34.2 ‘posix’ — The most common POSIX system calls
---------------------------------------------------

__________________________________________________________________

This module provides access to operating system functionality that is
standardized by the C Standard and the POSIX standard (a thinly
disguised Unix interface).

*note Availability: 2128.: Unix.

'Do not import this module directly.'  Instead, import the module *note
os: a5, which provides a 'portable' version of this interface.  On Unix,
the *note os: a5. module provides a superset of the *note posix: b2.
interface.  On non-Unix operating systems the *note posix: b2. module is
not available, but a subset is always available through the *note os:
a5. interface.  Once *note os: a5. is imported, there is 'no'
performance penalty in using it instead of *note posix: b2.  In
addition, *note os: a5. provides some additional functionality, such as
automatically calling *note putenv(): 25b. when an entry in ‘os.environ’
is changed.

Errors are reported as exceptions; the usual exceptions are given for
type errors, while errors reported by the system calls raise *note
OSError: 2c0.

* Menu:

* Large File Support::
* Notable Module Contents::


File: python.info,  Node: Large File Support,  Next: Notable Module Contents,  Up: posix — The most common POSIX system calls

5.34.2.1 Large File Support
...........................

Several operating systems (including AIX and Solaris) provide support
for files that are larger than 2 GiB from a C programming model where
int and long are 32-bit values.  This is typically accomplished by
defining the relevant size and offset types as 64-bit values.  Such
files are sometimes referred to as 'large files'.

Large file support is enabled in Python when the size of an ‘off_t’ is
larger than a long and the long long is at least as large as an ‘off_t’.
It may be necessary to configure and compile Python with certain
compiler flags to enable this mode.  For example, with Solaris 2.6 and
2.7 you need to do something like:

     CFLAGS="`getconf LFS_CFLAGS`" OPT="-g -O2 $CFLAGS" \
             ./configure

On large-file-capable Linux systems, this might work:

     CFLAGS='-D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64' OPT="-g -O2 $CFLAGS" \
             ./configure


File: python.info,  Node: Notable Module Contents,  Prev: Large File Support,  Up: posix — The most common POSIX system calls

5.34.2.2 Notable Module Contents
................................

In addition to many functions described in the *note os: a5. module
documentation, *note posix: b2. defines the following data item:

 -- Dati: posix.environ

     A dictionary representing the string environment at the time the
     interpreter was started.  Keys and values are bytes on Unix and str
     on Windows.  For example, ‘environ[b'HOME']’ (‘environ['HOME']’ on
     Windows) is the pathname of your home directory, equivalent to
     ‘getenv("HOME")’ in C.

     Modifying this dictionary does not affect the string environment
     passed on by *note execv(): 2ffe, *note popen(): 31a. or *note
     system(): 1664.; if you need to change the environment, pass
     ‘environ’ to *note execve(): 1301. or add variable assignments and
     export statements to the command string for *note system(): 1664.
     or *note popen(): 31a.

     Cambiato nella versione 3.2: On Unix, keys and values are bytes.

          Nota: The *note os: a5. module provides an alternate
          implementation of ‘environ’ which updates the environment on
          modification.  Note also that updating *note os.environ: 259.
          will render this dictionary obsolete.  Use of the *note os:
          a5. module version of this is recommended over direct access
          to the *note posix: b2. module.


File: python.info,  Node: pwd — The password database,  Next: grp — The group database,  Prev: posix — The most common POSIX system calls,  Up: Unix-specific services

5.34.3 ‘pwd’ — The password database
------------------------------------

__________________________________________________________________

This module provides access to the Unix user account and password
database.  It is available on all Unix versions.

*note Availability: 2128.: Unix, not WASI, not iOS.

Password database entries are reported as a tuple-like object, whose
attributes correspond to the members of the ‘passwd’ structure
(Attribute field below, see ‘<pwd.h>’):

Index       Attribute           Meaning
                                
------------------------------------------------------------------
                                
0           ‘pw_name’           Login name
                                
                                
1           ‘pw_passwd’         Optional encrypted password
                                
                                
2           ‘pw_uid’            Numerical user ID
                                
                                
3           ‘pw_gid’            Numerical group ID
                                
                                
4           ‘pw_gecos’          User name or comment field
                                
                                
5           ‘pw_dir’            User home directory
                                
                                
6           ‘pw_shell’          User command interpreter
                                

The uid and gid items are integers, all others are strings.  *note
KeyError: 5e7. is raised if the entry asked for cannot be found.

     Nota: In traditional Unix the field ‘pw_passwd’ usually contains a
     password encrypted with a DES derived algorithm.  However most
     modern unices use a so-called 'shadow password' system.  On those
     unices the 'pw_passwd' field only contains an asterisk (‘'*'’) or
     the letter ‘'x'’ where the encrypted password is stored in a file
     ‘/etc/shadow’ which is not world readable.  Whether the 'pw_passwd'
     field contains anything useful is system-dependent.

It defines the following items:

 -- Funzione: pwd.getpwuid (uid)

     Return the password database entry for the given numeric user ID.

 -- Funzione: pwd.getpwnam (name)

     Return the password database entry for the given user name.

 -- Funzione: pwd.getpwall ()

     Return a list of all available password database entries, in
     arbitrary order.

Vedi anche
..........

Module *note grp: 6a.

     An interface to the group database, similar to this.


File: python.info,  Node: grp — The group database,  Next: termios — POSIX style tty control,  Prev: pwd — The password database,  Up: Unix-specific services

5.34.4 ‘grp’ — The group database
---------------------------------

__________________________________________________________________

This module provides access to the Unix group database.  It is available
on all Unix versions.

*note Availability: 2128.: Unix, not WASI, not Android, not iOS.

Group database entries are reported as a tuple-like object, whose
attributes correspond to the members of the ‘group’ structure (Attribute
field below, see ‘<grp.h>’):

Index       Attribute       Meaning
                            
------------------------------------------------------------------
                            
0           gr_name         the name of the group
                            
                            
1           gr_passwd       the (encrypted) group password;
                            often empty
                            
                            
2           gr_gid          the numerical group ID
                            
                            
3           gr_mem          all the group member’s user names
                            

The gid is an integer, name and password are strings, and the member
list is a list of strings.  (Note that most users are not explicitly
listed as members of the group they are in according to the password
database.  Check both databases to get complete membership information.
Also note that a ‘gr_name’ that starts with a ‘+’ or ‘-’ is likely to be
a YP/NIS reference and may not be accessible via *note getgrnam(): 372c.
or *note getgrgid(): f24.)

It defines the following items:

 -- Funzione: grp.getgrgid (id)

     Return the group database entry for the given numeric group ID.
     *note KeyError: 5e7. is raised if the entry asked for cannot be
     found.

     Cambiato nella versione 3.10: *note TypeError: 198. is raised for
     non-integer arguments like floats or strings.

 -- Funzione: grp.getgrnam (name)

     Return the group database entry for the given group name.  *note
     KeyError: 5e7. is raised if the entry asked for cannot be found.

 -- Funzione: grp.getgrall ()

     Return a list of all available group entries, in arbitrary order.

Vedi anche
..........

Module *note pwd: b7.

     An interface to the user database, similar to this.


File: python.info,  Node: termios — POSIX style tty control,  Next: tty — Terminal control functions,  Prev: grp — The group database,  Up: Unix-specific services

5.34.5 ‘termios’ — POSIX style tty control
------------------------------------------

__________________________________________________________________

This module provides an interface to the POSIX calls for tty I/O
control.  For a complete description of these calls, see ‘termios(3)(1)’
Unix manual page.  It is only available for those Unix versions that
support POSIX 'termios' style tty I/O control configured during
installation.

*note Availability: 2128.: Unix.

All functions in this module take a file descriptor 'fd' as their first
argument.  This can be an integer file descriptor, such as returned by
‘sys.stdin.fileno()’, or a *note file object: 13cb, such as ‘sys.stdin’
itself.

This module also defines all the constants needed to work with the
functions provided here; these have the same name as their counterparts
in C. Please refer to your system documentation for more information on
using these terminal control interfaces.

The module defines the following functions:

 -- Funzione: termios.tcgetattr (fd)

     Return a list containing the tty attributes for file descriptor
     'fd', as follows: ‘[iflag, oflag, cflag, lflag, ispeed, ospeed,
     cc]’ where 'cc' is a list of the tty special characters (each a
     string of length 1, except the items with indices ‘VMIN’ and
     ‘VTIME’, which are integers when these fields are defined).  The
     interpretation of the flags and the speeds as well as the indexing
     in the 'cc' array must be done using the symbolic constants defined
     in the *note termios: e7. module.

 -- Funzione: termios.tcsetattr (fd, when, attributes)

     Set the tty attributes for file descriptor 'fd' from the
     'attributes', which is a list like the one returned by *note
     tcgetattr(): 19db.  The 'when' argument determines when the
     attributes are changed:

      -- Dati: termios.TCSANOW

          Change attributes immediately.

      -- Dati: termios.TCSADRAIN

          Change attributes after transmitting all queued output.

      -- Dati: termios.TCSAFLUSH

          Change attributes after transmitting all queued output and
          discarding all queued input.

 -- Funzione: termios.tcsendbreak (fd, duration)

     Send a break on file descriptor 'fd'.  A zero 'duration' sends a
     break for 0.25–0.5 seconds; a nonzero 'duration' has a system
     dependent meaning.

 -- Funzione: termios.tcdrain (fd)

     Wait until all output written to file descriptor 'fd' has been
     transmitted.

 -- Funzione: termios.tcflush (fd, queue)

     Discard queued data on file descriptor 'fd'.  The 'queue' selector
     specifies which queue: ‘TCIFLUSH’ for the input queue, ‘TCOFLUSH’
     for the output queue, or ‘TCIOFLUSH’ for both queues.

 -- Funzione: termios.tcflow (fd, action)

     Suspend or resume input or output on file descriptor 'fd'.  The
     'action' argument can be ‘TCOOFF’ to suspend output, ‘TCOON’ to
     restart output, ‘TCIOFF’ to suspend input, or ‘TCION’ to restart
     input.

 -- Funzione: termios.tcgetwinsize (fd)

     Return a tuple ‘(ws_row, ws_col)’ containing the tty window size
     for file descriptor 'fd'.  Requires ‘termios.TIOCGWINSZ’ or
     ‘termios.TIOCGSIZE’.

     Added in version 3.11.

 -- Funzione: termios.tcsetwinsize (fd, winsize)

     Set the tty window size for file descriptor 'fd' from 'winsize',
     which is a two-item tuple ‘(ws_row, ws_col)’ like the one returned
     by *note tcgetwinsize(): 4dc5.  Requires at least one of the pairs
     (‘termios.TIOCGWINSZ’, ‘termios.TIOCSWINSZ’); (‘termios.TIOCGSIZE’,
     ‘termios.TIOCSSIZE’) to be defined.

     Added in version 3.11.

Vedi anche
..........

Module *note tty: 106.

     Convenience functions for common terminal control operations.

* Menu:

* Example: Example<15>.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/termios(3)


File: python.info,  Node: Example<15>,  Up: termios — POSIX style tty control

5.34.5.1 Example
................

Here’s a function that prompts for a password with echoing turned off.
Note the technique using a separate *note tcgetattr(): 19db. call and a
*note try: 8f9. … *note finally: 1b0. statement to ensure that the old
tty attributes are restored exactly no matter what happens:

     def getpass(prompt="Password: "):
         import termios, sys
         fd = sys.stdin.fileno()
         old = termios.tcgetattr(fd)
         new = termios.tcgetattr(fd)
         new[3] = new[3] & ~termios.ECHO          # lflags
         try:
             termios.tcsetattr(fd, termios.TCSADRAIN, new)
             passwd = input(prompt)
         finally:
             termios.tcsetattr(fd, termios.TCSADRAIN, old)
         return passwd


File: python.info,  Node: tty — Terminal control functions,  Next: pty — Pseudo-terminal utilities,  Prev: termios — POSIX style tty control,  Up: Unix-specific services

5.34.6 ‘tty’ — Terminal control functions
-----------------------------------------

'Source code:' Lib/tty.py(1)

__________________________________________________________________

The *note tty: 106. module defines functions for putting the tty into
cbreak and raw modes.

*note Availability: 2128.: Unix.

Because it requires the *note termios: e7. module, it will work only on
Unix.

The *note tty: 106. module defines the following functions:

 -- Funzione: tty.cfmakeraw (mode)

     Convert the tty attribute list 'mode', which is a list like the one
     returned by *note termios.tcgetattr(): 19db, to that of a tty in
     raw mode.

     Added in version 3.12.

 -- Funzione: tty.cfmakecbreak (mode)

     Convert the tty attribute list 'mode', which is a list like the one
     returned by *note termios.tcgetattr(): 19db, to that of a tty in
     cbreak mode.

     This clears the ‘ECHO’ and ‘ICANON’ local mode flags in 'mode' as
     well as setting the minimum input to 1 byte with no delay.

     Added in version 3.12.

     Cambiato nella versione 3.12.2: The ‘ICRNL’ flag is no longer
     cleared.  This matches Linux and macOS ‘stty cbreak’ behavior and
     what *note setcbreak(): 19dd. historically did.

 -- Funzione: tty.setraw (fd, when=termios.TCSAFLUSH)

     Change the mode of the file descriptor 'fd' to raw.  If 'when' is
     omitted, it defaults to *note termios.TCSAFLUSH: 4dc0, and is
     passed to *note termios.tcsetattr(): 1a51.  The return value of
     *note termios.tcgetattr(): 19db. is saved before setting 'fd' to
     raw mode; this value is returned.

     Cambiato nella versione 3.12: The return value is now the original
     tty attributes, instead of ‘None’.

 -- Funzione: tty.setcbreak (fd, when=termios.TCSAFLUSH)

     Change the mode of file descriptor 'fd' to cbreak.  If 'when' is
     omitted, it defaults to *note termios.TCSAFLUSH: 4dc0, and is
     passed to *note termios.tcsetattr(): 1a51.  The return value of
     *note termios.tcgetattr(): 19db. is saved before setting 'fd' to
     cbreak mode; this value is returned.

     This clears the ‘ECHO’ and ‘ICANON’ local mode flags as well as
     setting the minimum input to 1 byte with no delay.

     Cambiato nella versione 3.12: The return value is now the original
     tty attributes, instead of ‘None’.

     Cambiato nella versione 3.12.2: The ‘ICRNL’ flag is no longer
     cleared.  This restores the behavior of Python 3.11 and earlier as
     well as matching what Linux, macOS, & BSDs describe in their
     ‘stty(1)’ man pages regarding cbreak mode.

Vedi anche
..........

Module *note termios: e7.

     Low-level terminal control interface.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/tty.py


File: python.info,  Node: pty — Pseudo-terminal utilities,  Next: fcntl — The fcntl and ioctl system calls,  Prev: tty — Terminal control functions,  Up: Unix-specific services

5.34.7 ‘pty’ — Pseudo-terminal utilities
----------------------------------------

'Source code:' Lib/pty.py(1)

__________________________________________________________________

The *note pty: b6. module defines operations for handling the
pseudo-terminal concept: starting another process and being able to
write to and read from its controlling terminal programmatically.

*note Availability: 2128.: Unix.

Pseudo-terminal handling is highly platform dependent.  This code is
mainly tested on Linux, FreeBSD, and macOS (it is supposed to work on
other POSIX platforms but it’s not been thoroughly tested).

The *note pty: b6. module defines the following functions:

 -- Funzione: pty.fork ()

     Fork.  Connect the child’s controlling terminal to a
     pseudo-terminal.  Return value is ‘(pid, fd)’.  Note that the child
     gets 'pid' 0, and the 'fd' is 'invalid'.  The parent’s return value
     is the 'pid' of the child, and 'fd' is a file descriptor connected
     to the child’s controlling terminal (and also to the child’s
     standard input and output).

          Avvertimento: On macOS the use of this function is unsafe when
          mixed with using higher-level system APIs, and that includes
          using *note urllib.request: 111.

 -- Funzione: pty.openpty ()

     Open a new pseudo-terminal pair, using *note os.openpty(): 303f. if
     possible, or emulation code for generic Unix systems.  Return a
     pair of file descriptors ‘(master, slave)’, for the master and the
     slave end, respectively.

 -- Funzione: pty.spawn (argv[, master_read[, stdin_read]])

     Spawn a process, and connect its controlling terminal with the
     current process’s standard io.  This is often used to baffle
     programs which insist on reading from the controlling terminal.  It
     is expected that the process spawned behind the pty will eventually
     terminate, and when it does 'spawn' will return.

     A loop copies STDIN of the current process to the child and data
     received from the child to STDOUT of the current process.  It is
     not signaled to the child if STDIN of the current process closes
     down.

     The functions 'master_read' and 'stdin_read' are passed a file
     descriptor which they should read from, and they should always
     return a byte string.  In order to force spawn to return before the
     child process exits an empty byte array should be returned to
     signal end of file.

     The default implementation for both functions will read and return
     up to 1024 bytes each time the function is called.  The
     'master_read' callback is passed the pseudoterminal’s master file
     descriptor to read output from the child process, and 'stdin_read'
     is passed file descriptor 0, to read from the parent process’s
     standard input.

     Returning an empty byte string from either callback is interpreted
     as an end-of-file (EOF) condition, and that callback will not be
     called after that.  If 'stdin_read' signals EOF the controlling
     terminal can no longer communicate with the parent process OR the
     child process.  Unless the child process will quit without any
     input, 'spawn' will then loop forever.  If 'master_read' signals
     EOF the same behavior results (on linux at least).

     Return the exit status value from *note os.waitpid(): f9c. on the
     child process.

     *note os.waitstatus_to_exitcode(): b19. can be used to convert the
     exit status into an exit code.

     Raises an *note auditing event: 1c56. ‘pty.spawn’ with argument
     ‘argv’.

     Cambiato nella versione 3.4: *note spawn(): 1184. now returns the
     status value from *note os.waitpid(): f9c. on the child process.

* Menu:

* Example: Example<16>.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/pty.py


File: python.info,  Node: Example<16>,  Up: pty — Pseudo-terminal utilities

5.34.7.1 Example
................

The following program acts like the Unix command ‘script(1)(1)’, using a
pseudo-terminal to record all input and output of a terminal session in
a «typescript».

     import argparse
     import os
     import pty
     import sys
     import time

     parser = argparse.ArgumentParser()
     parser.add_argument('-a', dest='append', action='store_true')
     parser.add_argument('-p', dest='use_python', action='store_true')
     parser.add_argument('filename', nargs='?', default='typescript')
     options = parser.parse_args()

     shell = sys.executable if options.use_python else os.environ.get('SHELL', 'sh')
     filename = options.filename
     mode = 'ab' if options.append else 'wb'

     with open(filename, mode) as script:
         def read(fd):
             data = os.read(fd, 1024)
             script.write(data)
             return data

         print('Script started, file is', filename)
         script.write(('Script started on %s\n' % time.asctime()).encode())

         pty.spawn(shell, read)

         script.write(('Script done on %s\n' % time.asctime()).encode())
         print('Script done, file is', filename)

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/script(1)


File: python.info,  Node: fcntl — The fcntl and ioctl system calls,  Next: resource — Resource usage information,  Prev: pty — Pseudo-terminal utilities,  Up: Unix-specific services

5.34.8 ‘fcntl’ — The ‘fcntl’ and ‘ioctl’ system calls
-----------------------------------------------------

__________________________________________________________________

This module performs file and I/O control on file descriptors.  It is an
interface to the ‘fcntl()’ and ‘ioctl()’ Unix routines.  See the
‘fcntl(2)(1)’ and ‘ioctl(2)(2)’ Unix manual pages for full details.

*note Availability: 2128.: Unix, not WASI.

All functions in this module take a file descriptor 'fd' as their first
argument.  This can be an integer file descriptor, such as returned by
‘sys.stdin.fileno()’, or an *note io.IOBase: 506. object, such as
‘sys.stdin’ itself, which provides a *note fileno(): 1795. that returns
a genuine file descriptor.

Cambiato nella versione 3.3: Operations in this module used to raise an
*note IOError: 1255. where they now raise an *note OSError: 2c0.

Cambiato nella versione 3.8: The ‘fcntl’ module now contains
‘F_ADD_SEALS’, ‘F_GET_SEALS’, and ‘F_SEAL_*’ constants for sealing of
*note os.memfd_create(): c00. file descriptors.

Cambiato nella versione 3.9: On macOS, the ‘fcntl’ module exposes the
‘F_GETPATH’ constant, which obtains the path of a file from a file
descriptor.  On Linux(>=3.15), the ‘fcntl’ module exposes the
‘F_OFD_GETLK’, ‘F_OFD_SETLK’ and ‘F_OFD_SETLKW’ constants, which are
used when working with open file description locks.

Cambiato nella versione 3.10: On Linux >= 2.6.11, the ‘fcntl’ module
exposes the ‘F_GETPIPE_SZ’ and ‘F_SETPIPE_SZ’ constants, which allow to
check and modify a pipe’s size respectively.

Cambiato nella versione 3.11: On FreeBSD, the ‘fcntl’ module exposes the
‘F_DUP2FD’ and ‘F_DUP2FD_CLOEXEC’ constants, which allow to duplicate a
file descriptor, the latter setting ‘FD_CLOEXEC’ flag in addition.

Cambiato nella versione 3.12: On Linux >= 4.5, the *note fcntl: 5d.
module exposes the ‘FICLONE’ and ‘FICLONERANGE’ constants, which allow
to share some data of one file with another file by reflinking on some
filesystems (e.g., btrfs, OCFS2, and XFS). This behavior is commonly
referred to as «copy-on-write».

Cambiato nella versione 3.13: On Linux >= 2.6.32, the ‘fcntl’ module
exposes the ‘F_GETOWN_EX’, ‘F_SETOWN_EX’, ‘F_OWNER_TID’, ‘F_OWNER_PID’,
‘F_OWNER_PGRP’ constants, which allow to direct I/O availability signals
to a specific thread, process, or process group.  On Linux >= 4.13, the
‘fcntl’ module exposes the ‘F_GET_RW_HINT’, ‘F_SET_RW_HINT’,
‘F_GET_FILE_RW_HINT’, ‘F_SET_FILE_RW_HINT’, and ‘RWH_WRITE_LIFE_*’
constants, which allow to inform the kernel about the relative expected
lifetime of writes on a given inode or via a particular open file
description.  On Linux >= 5.1 and NetBSD, the ‘fcntl’ module exposes the
‘F_SEAL_FUTURE_WRITE’ constant for use with ‘F_ADD_SEALS’ and
‘F_GET_SEALS’ operations.  On FreeBSD, the ‘fcntl’ module exposes the
‘F_READAHEAD’, ‘F_ISUNIONSTACK’, and ‘F_KINFO’ constants.  On macOS and
FreeBSD, the ‘fcntl’ module exposes the ‘F_RDAHEAD’ constant.  On NetBSD
and AIX, the ‘fcntl’ module exposes the ‘F_CLOSEM’ constant.  On NetBSD,
the ‘fcntl’ module exposes the ‘F_MAXFD’ constant.  On macOS and NetBSD,
the ‘fcntl’ module exposes the ‘F_GETNOSIGPIPE’ and ‘F_SETNOSIGPIPE’
constant.

Cambiato nella versione 3.14: On Linux >= 6.1, the ‘fcntl’ module
exposes the ‘F_DUPFD_QUERY’ to query a file descriptor pointing to the
same file.

The module defines the following functions:

 -- Funzione: fcntl.fcntl (fd, cmd, arg=0, /)

     Perform the operation 'cmd' on file descriptor 'fd' (file objects
     providing a *note fileno(): 1795. method are accepted as well).
     The values used for 'cmd' are operating system dependent, and are
     available as constants in the *note fcntl: 5d. module, using the
     same names as used in the relevant C header files.  The argument
     'arg' can either be an integer value, a *note bytes-like object:
     193, or a string.  The type and size of 'arg' must match the type
     and size of the argument of the operation as specified in the
     relevant C documentation.

     When 'arg' is an integer, the function returns the integer return
     value of the C ‘fcntl()’ call.

     When the argument is bytes-like object, it represents a binary
     structure, for example, created by *note struct.pack(): 147e.  A
     string value is encoded to binary using the UTF-8 encoding.  The
     binary data is copied to a buffer whose address is passed to the C
     ‘fcntl()’ call.  The return value after a successful call is the
     contents of the buffer, converted to a *note bytes: 192. object.
     The length of the returned object will be the same as the length of
     the 'arg' argument.  This is limited to 1024 bytes.

     If the ‘fcntl()’ call fails, an *note OSError: 2c0. is raised.

          Nota: If the type or the size of 'arg' does not match the type
          or size of the argument of the operation (for example, if an
          integer is passed when a pointer is expected, or the
          information returned in the buffer by the operating system is
          larger than 1024 bytes), this is most likely to result in a
          segmentation violation or a more subtle data corruption.

     Raises an *note auditing event: 1c56. ‘fcntl.fcntl’ with arguments
     ‘fd’, ‘cmd’, ‘arg’.

     Cambiato nella versione 3.14: Add support of arbitrary *note
     bytes-like objects: 193, not only *note bytes: 192.

 -- Funzione: fcntl.ioctl (fd, request, arg=0, mutate_flag=True, /)

     This function is identical to the *note fcntl(): 1839. function,
     except that the argument handling is even more complicated.

     The 'request' parameter is limited to values that can fit in
     32-bits or 64-bits, depending on the platform.  Additional
     constants of interest for use as the 'request' argument can be
     found in the *note termios: e7. module, under the same names as
     used in the relevant C header files.

     The parameter 'arg' can be an integer, a *note bytes-like object:
     193, or a string.  The type and size of 'arg' must match the type
     and size of the argument of the operation as specified in the
     relevant C documentation.

     If 'arg' does not support the read-write buffer interface or the
     'mutate_flag' is false, behavior is as for the *note fcntl(): 1839.
     function.

     If 'arg' supports the read-write buffer interface (like *note
     bytearray: 344.) and 'mutate_flag' is true (the default), then the
     buffer is (in effect) passed to the underlying ‘ioctl()’ system
     call, the latter’s return code is passed back to the calling
     Python, and the buffer’s new contents reflect the action of the
     ‘ioctl()’.  This is a slight simplification, because if the
     supplied buffer is less than 1024 bytes long it is first copied
     into a static buffer 1024 bytes long which is then passed to *note
     ioctl(): 1682. and copied back into the supplied buffer.

     If the ‘ioctl()’ call fails, an *note OSError: 2c0. exception is
     raised.

          Nota: If the type or size of 'arg' does not match the type or
          size of the operation’s argument (for example, if an integer
          is passed when a pointer is expected, or the information
          returned in the buffer by the operating system is larger than
          1024 bytes, or the size of the mutable bytes-like object is
          too small), this is most likely to result in a segmentation
          violation or a more subtle data corruption.

     An example:

          >>> import array, fcntl, struct, termios, os
          >>> os.getpgrp()
          13341
          >>> struct.unpack('h', fcntl.ioctl(0, termios.TIOCGPGRP, "  "))[0]
          13341
          >>> buf = array.array('h', [0])
          >>> fcntl.ioctl(0, termios.TIOCGPGRP, buf, 1)
          0
          >>> buf
          array('h', [13341])

     Raises an *note auditing event: 1c56. ‘fcntl.ioctl’ with arguments
     ‘fd’, ‘request’, ‘arg’.

     Cambiato nella versione 3.14: The GIL is always released during a
     system call.  System calls failing with EINTR are automatically
     retried.

 -- Funzione: fcntl.flock (fd, operation, /)

     Perform the lock operation 'operation' on file descriptor 'fd'
     (file objects providing a *note fileno(): 1795. method are accepted
     as well).  See the Unix manual ‘flock(2)(3)’ for details.  (On some
     systems, this function is emulated using ‘fcntl()’.)

     If the ‘flock()’ call fails, an *note OSError: 2c0. exception is
     raised.

     Raises an *note auditing event: 1c56. ‘fcntl.flock’ with arguments
     ‘fd’, ‘operation’.

 -- Funzione: fcntl.lockf (fd, cmd, len=0, start=0, whence=0, /)

     This is essentially a wrapper around the *note fcntl(): 1839.
     locking calls.  'fd' is the file descriptor (file objects providing
     a *note fileno(): 1795. method are accepted as well) of the file to
     lock or unlock, and 'cmd' is one of the following values:

      -- Dati: fcntl.LOCK_UN

          Release an existing lock.

      -- Dati: fcntl.LOCK_SH

          Acquire a shared lock.

      -- Dati: fcntl.LOCK_EX

          Acquire an exclusive lock.

      -- Dati: fcntl.LOCK_NB

          Bitwise OR with any of the other three ‘LOCK_*’ constants to
          make the request non-blocking.

     If ‘LOCK_NB’ is used and the lock cannot be acquired, an *note
     OSError: 2c0. will be raised and the exception will have an 'errno'
     attribute set to *note EACCES: 26ef. or *note EAGAIN: 26e0.
     (depending on the operating system; for portability, check for both
     values).  On at least some systems, ‘LOCK_EX’ can only be used if
     the file descriptor refers to a file opened for writing.

     'len' is the number of bytes to lock, 'start' is the byte offset at
     which the lock starts, relative to 'whence', and 'whence' is as
     with *note io.IOBase.seek(): 1494, specifically:

        * ‘0’ – relative to the start of the file (*note os.SEEK_SET:
          1495.)

        * ‘1’ – relative to the current buffer position (*note
          os.SEEK_CUR: 1496.)

        * ‘2’ – relative to the end of the file (*note os.SEEK_END:
          1497.)

     The default for 'start' is 0, which means to start at the beginning
     of the file.  The default for 'len' is 0 which means to lock to the
     end of the file.  The default for 'whence' is also 0.

     Raises an *note auditing event: 1c56. ‘fcntl.lockf’ with arguments
     ‘fd’, ‘cmd’, ‘len’, ‘start’, ‘whence’.

Examples (all on a SVR4 compliant system):

     import struct, fcntl, os

     f = open(...)
     rv = fcntl.fcntl(f, fcntl.F_SETFL, os.O_NDELAY)

     lockdata = struct.pack('hhllhh', fcntl.F_WRLCK, 0, 0, 0, 0, 0)
     rv = fcntl.fcntl(f, fcntl.F_SETLKW, lockdata)

Note that in the first example the return value variable 'rv' will hold
an integer value; in the second example it will hold a *note bytes: 192.
object.  The structure lay-out for the 'lockdata' variable is system
dependent — therefore using the *note flock(): 4744. call may be better.

Vedi anche
..........

Module *note os: a5.

     If the locking flags *note O_SHLOCK: 1636. and *note O_EXLOCK:
     1637. are present in the *note os: a5. module (on BSD only), the
     *note os.open(): f94. function provides an alternative to the *note
     lockf(): 15f3. and *note flock(): 4744. functions.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/fcntl(2)

   (2) https://manpages.debian.org/ioctl(2)

   (3) https://manpages.debian.org/flock(2)


File: python.info,  Node: resource — Resource usage information,  Next: syslog — Unix syslog library routines,  Prev: fcntl — The fcntl and ioctl system calls,  Up: Unix-specific services

5.34.9 ‘resource’ — Resource usage information
----------------------------------------------

__________________________________________________________________

This module provides basic mechanisms for measuring and controlling
system resources utilized by a program.

*note Availability: 2128.: Unix, not WASI.

Symbolic constants are used to specify particular system resources and
to request usage information about either the current process or its
children.

An *note OSError: 2c0. is raised on syscall failure.

 -- Eccezione: resource.error

     A deprecated alias of *note OSError: 2c0.

     Cambiato nella versione 3.3: Following PEP 3151(1), this class was
     made an alias of *note OSError: 2c0.

* Menu:

* Resource Limits::
* Resource Usage::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3151/


File: python.info,  Node: Resource Limits,  Next: Resource Usage,  Up: resource — Resource usage information

5.34.9.1 Resource Limits
........................

Resources usage can be limited using the *note setrlimit(): 17ae.
function described below.  Each resource is controlled by a pair of
limits: a soft limit and a hard limit.  The soft limit is the current
limit, and may be lowered or raised by a process over time.  The soft
limit can never exceed the hard limit.  The hard limit can be lowered to
any value greater than the soft limit, but not raised.  (Only processes
with the effective UID of the super-user can raise a hard limit.)

The specific resources that can be limited are system dependent.  They
are described in the ‘getrlimit(2)(1)’ man page.  The resources listed
below are supported when the underlying operating system supports them;
resources which cannot be checked or controlled by the operating system
are not defined in this module for those platforms.

 -- Dati: resource.RLIM_INFINITY

     Constant used to represent the limit for an unlimited resource.

 -- Funzione: resource.getrlimit (resource)

     Returns a tuple ‘(soft, hard)’ with the current soft and hard
     limits of 'resource'.  Raises *note ValueError: 2ec. if an invalid
     resource is specified, or *note error: 4dda. if the underlying
     system call fails unexpectedly.

 -- Funzione: resource.setrlimit (resource, limits)

     Sets new limits of consumption of 'resource'.  The 'limits'
     argument must be a tuple ‘(soft, hard)’ of two integers describing
     the new limits.  A value of *note RLIM_INFINITY: 17ad. can be used
     to request a limit that is unlimited.

     Raises *note ValueError: 2ec. if an invalid resource is specified,
     if the new soft limit exceeds the hard limit, or if a process tries
     to raise its hard limit.  Specifying a limit of *note
     RLIM_INFINITY: 17ad. when the hard or system limit for that
     resource is not unlimited will result in a *note ValueError: 2ec.
     A process with the effective UID of super-user can request any
     valid limit value, including unlimited, but *note ValueError: 2ec.
     will still be raised if the requested limit exceeds the system
     imposed limit.

     ‘setrlimit’ may also raise *note error: 4dda. if the underlying
     system call fails.

     VxWorks only supports setting *note RLIMIT_NOFILE: 4ddc.

     Raises an *note auditing event: 1c56. ‘resource.setrlimit’ with
     arguments ‘resource’, ‘limits’.

 -- Funzione: resource.prlimit (pid, resource[, limits])

     Combines *note setrlimit(): 17ae. and *note getrlimit(): 17ac. in
     one function and supports to get and set the resources limits of an
     arbitrary process.  If 'pid' is 0, then the call applies to the
     current process.  'resource' and 'limits' have the same meaning as
     in *note setrlimit(): 17ae, except that 'limits' is optional.

     When 'limits' is not given the function returns the 'resource'
     limit of the process 'pid'.  When 'limits' is given the 'resource'
     limit of the process is set and the former resource limit is
     returned.

     Raises *note ProcessLookupError: 125d. when 'pid' can’t be found
     and *note PermissionError: f40. when the user doesn’t have
     ‘CAP_SYS_RESOURCE’ for the process.

     Raises an *note auditing event: 1c56. ‘resource.prlimit’ with
     arguments ‘pid’, ‘resource’, ‘limits’.

     *note Availability: 2128.: Linux >= 2.6.36 with glibc >= 2.13.

     Added in version 3.4.

These symbols define resources whose consumption can be controlled using
the *note setrlimit(): 17ae. and *note getrlimit(): 17ac. functions
described below.  The values of these symbols are exactly the constants
used by C programs.

The Unix man page for ‘getrlimit(2)(2)’ lists the available resources.
Note that not all systems use the same symbol or same value to denote
the same resource.  This module does not attempt to mask platform
differences — symbols not defined for a platform will not be available
from this module on that platform.

 -- Dati: resource.RLIMIT_CORE

     The maximum size (in bytes) of a core file that the current process
     can create.  This may result in the creation of a partial core file
     if a larger core would be required to contain the entire process
     image.

 -- Dati: resource.RLIMIT_CPU

     The maximum amount of processor time (in seconds) that a process
     can use.  If this limit is exceeded, a *note SIGXCPU: 3a56. signal
     is sent to the process.  (See the *note signal: cb. module
     documentation for information about how to catch this signal and do
     something useful, e.g.  flush open files to disk.)

 -- Dati: resource.RLIMIT_FSIZE

     The maximum size of a file which the process may create.

 -- Dati: resource.RLIMIT_DATA

     The maximum size (in bytes) of the process’s heap.

 -- Dati: resource.RLIMIT_STACK

     The maximum size (in bytes) of the call stack for the current
     process.  This only affects the stack of the main thread in a
     multi-threaded process.

 -- Dati: resource.RLIMIT_RSS

     The maximum resident set size that should be made available to the
     process.

 -- Dati: resource.RLIMIT_NPROC

     The maximum number of processes the current process may create.

 -- Dati: resource.RLIMIT_NOFILE

     The maximum number of open file descriptors for the current
     process.

 -- Dati: resource.RLIMIT_OFILE

     The BSD name for *note RLIMIT_NOFILE: 4ddc.

 -- Dati: resource.RLIMIT_MEMLOCK

     The maximum address space which may be locked in memory.

 -- Dati: resource.RLIMIT_VMEM

     The largest area of mapped memory which the process may occupy.
     Usually an alias of *note RLIMIT_AS: 4de6.

     *note Availability: 2128.: Solaris, FreeBSD, NetBSD.

 -- Dati: resource.RLIMIT_AS

     The maximum area (in bytes) of address space which may be taken by
     the process.

 -- Dati: resource.RLIMIT_MSGQUEUE

     The number of bytes that can be allocated for POSIX message queues.

     *note Availability: 2128.: Linux >= 2.6.8.

     Added in version 3.4.

 -- Dati: resource.RLIMIT_NICE

     The ceiling for the process’s nice level (calculated as 20 -
     rlim_cur).

     *note Availability: 2128.: Linux >= 2.6.12.

     Added in version 3.4.

 -- Dati: resource.RLIMIT_RTPRIO

     The ceiling of the real-time priority.

     *note Availability: 2128.: Linux >= 2.6.12.

     Added in version 3.4.

 -- Dati: resource.RLIMIT_RTTIME

     The time limit (in microseconds) on CPU time that a process can
     spend under real-time scheduling without making a blocking syscall.

     *note Availability: 2128.: Linux >= 2.6.25.

     Added in version 3.4.

 -- Dati: resource.RLIMIT_SIGPENDING

     The number of signals which the process may queue.

     *note Availability: 2128.: Linux >= 2.6.8.

     Added in version 3.4.

 -- Dati: resource.RLIMIT_SBSIZE

     The maximum size (in bytes) of socket buffer usage for this user.
     This limits the amount of network memory, and hence the amount of
     mbufs, that this user may hold at any time.

     *note Availability: 2128.: FreeBSD, NetBSD.

     Added in version 3.4.

 -- Dati: resource.RLIMIT_SWAP

     The maximum size (in bytes) of the swap space that may be reserved
     or used by all of this user id’s processes.  This limit is enforced
     only if bit 1 of the vm.overcommit sysctl is set.  Please see
     tuning(7)(3) for a complete description of this sysctl.

     *note Availability: 2128.: FreeBSD >= 8.

     Added in version 3.4.

 -- Dati: resource.RLIMIT_NPTS

     The maximum number of pseudo-terminals created by this user id.

     *note Availability: 2128.: FreeBSD >= 8.

     Added in version 3.4.

 -- Dati: resource.RLIMIT_KQUEUES

     The maximum number of kqueues this user id is allowed to create.

     *note Availability: 2128.: FreeBSD >= 11.

     Added in version 3.10.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/getrlimit(2)

   (2) https://manpages.debian.org/getrlimit(2)

   (3) https://man.freebsd.org/cgi/man.cgi?query=tuning&sektion=7


File: python.info,  Node: Resource Usage,  Prev: Resource Limits,  Up: resource — Resource usage information

5.34.9.2 Resource Usage
.......................

These functions are used to retrieve resource usage information:

 -- Funzione: resource.getrusage (who)

     This function returns an object that describes the resources
     consumed by either the current process or its children, as
     specified by the 'who' parameter.  The 'who' parameter should be
     specified using one of the ‘RUSAGE_*’ constants described below.

     A simple example:

          from resource import *
          import time

          # a non CPU-bound task
          time.sleep(3)
          print(getrusage(RUSAGE_SELF))

          # a CPU-bound task
          for i in range(10 ** 8):
             _ = 1 + 1
          print(getrusage(RUSAGE_SELF))

     The fields of the return value each describe how a particular
     system resource has been used, e.g.  amount of time spent running
     is user mode or number of times the process was swapped out of main
     memory.  Some values are dependent on the clock tick internal, e.g.
     the amount of memory the process is using.

     For backward compatibility, the return value is also accessible as
     a tuple of 16 elements.

     The fields ‘ru_utime’ and ‘ru_stime’ of the return value are
     floating-point values representing the amount of time spent
     executing in user mode and the amount of time spent executing in
     system mode, respectively.  The remaining values are integers.
     Consult the ‘getrusage(2)(1)’ man page for detailed information
     about these values.  A brief summary is presented here:

     Index        Field                      Resource
                                             
     ------------------------------------------------------------------------------------
                                             
     ‘0’          ‘ru_utime’                 time in user mode (float seconds)
                                             
                                             
     ‘1’          ‘ru_stime’                 time in system mode (float seconds)
                                             
                                             
     ‘2’          ‘ru_maxrss’                maximum resident set size
                                             
                                             
     ‘3’          ‘ru_ixrss’                 shared memory size
                                             
                                             
     ‘4’          ‘ru_idrss’                 unshared memory size
                                             
                                             
     ‘5’          ‘ru_isrss’                 unshared stack size
                                             
                                             
     ‘6’          ‘ru_minflt’                page faults not requiring I/O
                                             
                                             
     ‘7’          ‘ru_majflt’                page faults requiring I/O
                                             
                                             
     ‘8’          ‘ru_nswap’                 number of swap outs
                                             
                                             
     ‘9’          ‘ru_inblock’               block input operations
                                             
                                             
     ‘10’         ‘ru_oublock’               block output operations
                                             
                                             
     ‘11’         ‘ru_msgsnd’                messages sent
                                             
                                             
     ‘12’         ‘ru_msgrcv’                messages received
                                             
                                             
     ‘13’         ‘ru_nsignals’              signals received
                                             
                                             
     ‘14’         ‘ru_nvcsw’                 voluntary context switches
                                             
                                             
     ‘15’         ‘ru_nivcsw’                involuntary context switches
                                             

     This function will raise a *note ValueError: 2ec. if an invalid
     'who' parameter is specified.  It may also raise *note error: 4dda.
     exception in unusual circumstances.

 -- Funzione: resource.getpagesize ()

     Returns the number of bytes in a system page.  (This need not be
     the same as the hardware page size.)

The following ‘RUSAGE_*’ symbols are passed to the *note getrusage():
1638. function to specify which processes information should be provided
for.

 -- Dati: resource.RUSAGE_SELF

     Pass to *note getrusage(): 1638. to request resources consumed by
     the calling process, which is the sum of resources used by all
     threads in the process.

 -- Dati: resource.RUSAGE_CHILDREN

     Pass to *note getrusage(): 1638. to request resources consumed by
     child processes of the calling process which have been terminated
     and waited for.

 -- Dati: resource.RUSAGE_BOTH

     Pass to *note getrusage(): 1638. to request resources consumed by
     both the current process and child processes.  May not be available
     on all systems.

 -- Dati: resource.RUSAGE_THREAD

     Pass to *note getrusage(): 1638. to request resources consumed by
     the current thread.  May not be available on all systems.

     Added in version 3.2.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/getrusage(2)


File: python.info,  Node: syslog — Unix syslog library routines,  Prev: resource — Resource usage information,  Up: Unix-specific services

5.34.10 ‘syslog’ — Unix syslog library routines
-----------------------------------------------

__________________________________________________________________

This module provides an interface to the Unix ‘syslog’ library routines.
Refer to the Unix manual pages for a detailed description of the
‘syslog’ facility.

*note Availability: 2128.: Unix, not WASI, not iOS.

This module wraps the system ‘syslog’ family of routines.  A pure Python
library that can speak to a syslog server is available in the *note
logging.handlers: 8d. module as *note SysLogHandler: 86d.

The module defines the following functions:

 -- Funzione: syslog.syslog (message)

 -- Funzione: syslog.syslog (priority, message)

     Send the string 'message' to the system logger.  A trailing newline
     is added if necessary.  Each message is tagged with a priority
     composed of a 'facility' and a 'level'.  The optional 'priority'
     argument, which defaults to *note LOG_INFO: 4df0, determines the
     message priority.  If the facility is not encoded in 'priority'
     using logical-or (‘LOG_INFO | LOG_USER’), the value given in the
     *note openlog(): 761. call is used.

     If *note openlog(): 761. has not been called prior to the call to
     *note syslog(): e2, *note openlog(): 761. will be called with no
     arguments.

     Raises an *note auditing event: 1c56. ‘syslog.syslog’ with
     arguments ‘priority’, ‘message’.

     Cambiato nella versione 3.2: In previous versions, *note openlog():
     761. would not be called automatically if it wasn’t called prior to
     the call to *note syslog(): e2, deferring to the syslog
     implementation to call ‘openlog()’.

     Cambiato nella versione 3.12: This function is restricted in
     subinterpreters.  (Only code that runs in multiple interpreters is
     affected and the restriction is not relevant for most users.)
     *note openlog(): 761. must be called in the main interpreter before
     *note syslog(): e2. may be used in a subinterpreter.  Otherwise it
     will raise *note RuntimeError: 244.

 -- Funzione: syslog.openlog ([ident[, logoption[, facility]]])

     Logging options of subsequent *note syslog(): e2. calls can be set
     by calling *note openlog(): 761.  *note syslog(): e2. will call
     *note openlog(): 761. with no arguments if the log is not currently
     open.

     The optional 'ident' keyword argument is a string which is
     prepended to every message, and defaults to ‘sys.argv[0]’ with
     leading path components stripped.  The optional 'logoption' keyword
     argument (default is 0) is a bit field – see below for possible
     values to combine.  The optional 'facility' keyword argument
     (default is *note LOG_USER: 4df1.) sets the default facility for
     messages which do not have a facility explicitly encoded.

     Raises an *note auditing event: 1c56. ‘syslog.openlog’ with
     arguments ‘ident’, ‘logoption’, ‘facility’.

     Cambiato nella versione 3.2: In previous versions, keyword
     arguments were not allowed, and 'ident' was required.

     Cambiato nella versione 3.12: This function is restricted in
     subinterpreters.  (Only code that runs in multiple interpreters is
     affected and the restriction is not relevant for most users.)  This
     may only be called in the main interpreter.  It will raise *note
     RuntimeError: 244. if called in a subinterpreter.

 -- Funzione: syslog.closelog ()

     Reset the syslog module values and call the system library
     ‘closelog()’.

     This causes the module to behave as it does when initially
     imported.  For example, *note openlog(): 761. will be called on the
     first *note syslog(): e2. call (if *note openlog(): 761. hasn’t
     already been called), and 'ident' and other *note openlog(): 761.
     parameters are reset to defaults.

     Raises an *note auditing event: 1c56. ‘syslog.closelog’ with no
     arguments.

     Cambiato nella versione 3.12: This function is restricted in
     subinterpreters.  (Only code that runs in multiple interpreters is
     affected and the restriction is not relevant for most users.)  This
     may only be called in the main interpreter.  It will raise *note
     RuntimeError: 244. if called in a subinterpreter.

 -- Funzione: syslog.setlogmask (maskpri)

     Set the priority mask to 'maskpri' and return the previous mask
     value.  Calls to *note syslog(): e2. with a priority level not set
     in 'maskpri' are ignored.  The default is to log all priorities.
     The function ‘LOG_MASK(pri)’ calculates the mask for the individual
     priority 'pri'.  The function ‘LOG_UPTO(pri)’ calculates the mask
     for all priorities up to and including 'pri'.

     Raises an *note auditing event: 1c56. ‘syslog.setlogmask’ with
     argument ‘maskpri’.

The module defines the following constants:

 -- Dati: syslog.LOG_EMERG
 -- Dati: syslog.LOG_ALERT
 -- Dati: syslog.LOG_CRIT
 -- Dati: syslog.LOG_ERR
 -- Dati: syslog.LOG_WARNING
 -- Dati: syslog.LOG_NOTICE
 -- Dati: syslog.LOG_INFO
 -- Dati: syslog.LOG_DEBUG

     Priority levels (high to low).

 -- Dati: syslog.LOG_AUTH
 -- Dati: syslog.LOG_AUTHPRIV
 -- Dati: syslog.LOG_CRON
 -- Dati: syslog.LOG_DAEMON
 -- Dati: syslog.LOG_FTP
 -- Dati: syslog.LOG_INSTALL
 -- Dati: syslog.LOG_KERN
 -- Dati: syslog.LOG_LAUNCHD
 -- Dati: syslog.LOG_LPR
 -- Dati: syslog.LOG_MAIL
 -- Dati: syslog.LOG_NETINFO
 -- Dati: syslog.LOG_NEWS
 -- Dati: syslog.LOG_RAS
 -- Dati: syslog.LOG_REMOTEAUTH
 -- Dati: syslog.LOG_SYSLOG
 -- Dati: syslog.LOG_USER
 -- Dati: syslog.LOG_UUCP
 -- Dati: syslog.LOG_LOCAL0
 -- Dati: syslog.LOG_LOCAL1
 -- Dati: syslog.LOG_LOCAL2
 -- Dati: syslog.LOG_LOCAL3
 -- Dati: syslog.LOG_LOCAL4
 -- Dati: syslog.LOG_LOCAL5
 -- Dati: syslog.LOG_LOCAL6
 -- Dati: syslog.LOG_LOCAL7

     Facilities, depending on availability in ‘<syslog.h>’ for *note
     LOG_AUTHPRIV: 4dfa, *note LOG_FTP: 4dfd, *note LOG_NETINFO: 4e03,
     *note LOG_REMOTEAUTH: 4e06, *note LOG_INSTALL: 4dfe. and *note
     LOG_RAS: 4e05.

     Cambiato nella versione 3.13: Added *note LOG_FTP: 4dfd, *note
     LOG_NETINFO: 4e03, *note LOG_REMOTEAUTH: 4e06, *note LOG_INSTALL:
     4dfe, *note LOG_RAS: 4e05, and *note LOG_LAUNCHD: 4e00.

 -- Dati: syslog.LOG_PID
 -- Dati: syslog.LOG_CONS
 -- Dati: syslog.LOG_NDELAY
 -- Dati: syslog.LOG_ODELAY
 -- Dati: syslog.LOG_NOWAIT
 -- Dati: syslog.LOG_PERROR

     Log options, depending on availability in ‘<syslog.h>’ for *note
     LOG_ODELAY: 4e14, *note LOG_NOWAIT: 4e15. and *note LOG_PERROR:
     4e16.

* Menu:

* Examples: Examples<37>.


File: python.info,  Node: Examples<37>,  Up: syslog — Unix syslog library routines

5.34.10.1 Examples
..................

* Menu:

* Simple example::


File: python.info,  Node: Simple example,  Up: Examples<37>

5.34.10.2 Simple example
........................

A simple set of examples:

     import syslog

     syslog.syslog('Processing started')
     if error:
         syslog.syslog(syslog.LOG_ERR, 'Processing started')

An example of setting some log options, these would include the process
ID in logged messages, and write the messages to the destination
facility used for mail logging:

     syslog.openlog(logoption=syslog.LOG_PID, facility=syslog.LOG_MAIL)
     syslog.syslog('E-mail processing initiated...')


File: python.info,  Node: Modules command-line interface CLI,  Next: Superseded Modules,  Prev: Unix-specific services,  Up: The Python Standard Library

5.35 Modules command-line interface (CLI)
=========================================

The following modules have a command-line interface.

   * *note ast: 4bc4.

   * *note asyncio: 37a8.

   * *note base64: f.

   * *note calendar: 1d0.

   * *note code: 1b.

   * *note compileall: 4c81.

   * *note cProfile: 2b.: see *note profile: 47e6.

   * *note dis: 4c98.

   * *note doctest: 453e.

   * ‘encodings.rot_13’

   * *note ensurepip: 4890.

   * *note filecmp: 5e.

   * *note fileinput: 5f.

   * *note ftplib: 62.

   * *note gzip: 2e40.

   * *note http.server: 1153.

   * *note idlelib: 43ef.

   * *note inspect: 115d.

   * *note json: 23e.

   * *note mimetypes: 247.

   * *note pdb: 2e2.

   * *note pickle: 2d14.

   * *note pickletools: 2d15.

   * *note platform: 322a.

   * *note poplib: b1.

   * *note profile: 47e6.

   * *note pstats: b5.

   * *note py_compile: 4c78.

   * *note pyclbr: b9.

   * *note pydoc: ba.

   * *note quopri: bc.

   * *note random: 47f.

   * *note runpy: c3.

   * *note site: 4a97.

   * *note sqlite3: 674.

   * *note symtable: 4bfb.

   * *note sysconfig: 495c.

   * *note tabnanny: e3.

   * *note tarfile: 11cd.

   * ‘this’

   * *note timeit: 480a.

   * *note tokenize: 4c49.

   * *note trace: 4827.

   * *note turtledemo: 108.

   * *note unittest: 45b7.

   * *note uuid: 676.

   * *note venv: 489e.

   * *note webbrowser: 3eaa.

   * *note zipapp: 48b8.

   * *note zipfile: 2eaf.

See also the *note Python command-line interface: 1d8f.


File: python.info,  Node: Superseded Modules,  Next: Removed Modules,  Prev: Modules command-line interface CLI,  Up: The Python Standard Library

5.36 Superseded Modules
=======================

The modules described in this chapter have been superseded by other
modules for most use cases, and are retained primarily to preserve
backwards compatibility.

Modules may appear in this chapter because they only cover a limited
subset of a problem space, and a more generally applicable solution is
available elsewhere in the standard library (for example, *note getopt:
65. covers the very specific task of «mimic the C ‘getopt()’ API in
Python», rather than the broader command line option parsing and
argument parsing capabilities offered by *note optparse: a4. and *note
argparse: 7.).

Alternatively, modules may appear in this chapter because they are
deprecated outright, and awaiting removal in a future release, or they
are *note soft deprecated: 23d. and their use is actively discouraged in
new projects.  With the removal of various obsolete modules through PEP
594(1), there are currently no modules in this latter category.

* Menu:

* getopt — C-style parser for command line options::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/


File: python.info,  Node: getopt — C-style parser for command line options,  Up: Superseded Modules

5.36.1 ‘getopt’ — C-style parser for command line options
---------------------------------------------------------

'Source code:' Lib/getopt.py(1)

     Nota: This module is considered feature complete.  A more
     declarative and extensible alternative to this API is provided in
     the *note optparse: a4. module.  Further functional enhancements
     for command line parameter processing are provided either as third
     party modules on PyPI, or else as features in the *note argparse:
     7. module.

__________________________________________________________________

This module helps scripts to parse the command line arguments in
‘sys.argv’.  It supports the same conventions as the Unix ‘getopt()’
function (including the special meanings of arguments of the form “‘-’”
and “‘--’“).  Long options similar to those supported by GNU software
may be used as well via an optional third argument.

Users who are unfamiliar with the Unix ‘getopt()’ function should
consider using the *note argparse: 7. module instead.  Users who are
familiar with the Unix ‘getopt()’ function, but would like to get
equivalent behavior while writing less code and getting better help and
error messages should consider using the *note optparse: a4. module.
See *note Choosing an argument parsing library: 3351. for additional
details.

This module provides two functions and an exception:

 -- Funzione: getopt.getopt (args, shortopts, longopts=[])

     Parses command line options and parameter list.  'args' is the
     argument list to be parsed, without the leading reference to the
     running program.  Typically, this means ‘sys.argv[1:]’.
     'shortopts' is the string of option letters that the script wants
     to recognize, with options that require an argument followed by a
     colon (‘':'’) and options that accept an optional argument followed
     by two colons (‘'::'’); i.e., the same format that Unix ‘getopt()’
     uses.

          Nota: Unlike GNU ‘getopt()’, after a non-option argument, all
          further arguments are considered also non-options.  This is
          similar to the way non-GNU Unix systems work.

     'longopts', if specified, must be a list of strings with the names
     of the long options which should be supported.  The leading ‘'--'’
     characters should not be included in the option name.  Long options
     which require an argument should be followed by an equal sign
     (‘'='’).  Long options which accept an optional argument should be
     followed by an equal sign and question mark (‘'=?'’).  To accept
     only long options, 'shortopts' should be an empty string.  Long
     options on the command line can be recognized so long as they
     provide a prefix of the option name that matches exactly one of the
     accepted options.  For example, if 'longopts' is ‘['foo', 'frob']’,
     the option ‘--fo’ will match as ‘--foo’, but ‘--f’ will not match
     uniquely, so *note GetoptError: 18d2. will be raised.

     The return value consists of two elements: the first is a list of
     ‘(option, value)’ pairs; the second is the list of program
     arguments left after the option list was stripped (this is a
     trailing slice of 'args').  Each option-and-value pair returned has
     the option as its first element, prefixed with a hyphen for short
     options (e.g., ‘'-x'’) or two hyphens for long options (e.g.,
     ‘'--long-option'’), and the option argument as its second element,
     or an empty string if the option has no argument.  The options
     occur in the list in the same order in which they were found, thus
     allowing multiple occurrences.  Long and short options may be
     mixed.

     Cambiato nella versione 3.14: Optional arguments are supported.

 -- Funzione: getopt.gnu_getopt (args, shortopts, longopts=[])

     This function works like *note getopt(): 65, except that GNU style
     scanning mode is used by default.  This means that option and
     non-option arguments may be intermixed.  The *note getopt(): 65.
     function stops processing options as soon as a non-option argument
     is encountered.

     If the first character of the option string is ‘'+'’, or if the
     environment variable ‘POSIXLY_CORRECT’ is set, then option
     processing stops as soon as a non-option argument is encountered.

     If the first character of the option string is ‘'-'’, non-option
     arguments that are followed by options are added to the list of
     option-and-value pairs as a pair that has ‘None’ as its first
     element and the list of non-option arguments as its second element.
     The second element of the ‘gnu_getopt()’ result is a list of
     program arguments after the last option.

     Cambiato nella versione 3.14: Support for returning intermixed
     options and non-option arguments in order.

 -- Eccezione: getopt.GetoptError

     This is raised when an unrecognized option is found in the argument
     list or when an option requiring an argument is given none.  The
     argument to the exception is a string indicating the cause of the
     error.  For long options, an argument given to an option which does
     not require one will also cause this exception to be raised.  The
     attributes ‘msg’ and ‘opt’ give the error message and related
     option; if there is no specific option to which the exception
     relates, ‘opt’ is an empty string.

 -- Eccezione: getopt.error

     Alias for *note GetoptError: 18d2.; for backward compatibility.

An example using only Unix style options:

     >>> import getopt
     >>> args = '-a -b -cfoo -d bar a1 a2'.split()
     >>> args
     ['-a', '-b', '-cfoo', '-d', 'bar', 'a1', 'a2']
     >>> optlist, args = getopt.getopt(args, 'abc:d:')
     >>> optlist
     [('-a', ''), ('-b', ''), ('-c', 'foo'), ('-d', 'bar')]
     >>> args
     ['a1', 'a2']

Using long option names is equally easy:

     >>> s = '--condition=foo --testing --output-file abc.def -x a1 a2'
     >>> args = s.split()
     >>> args
     ['--condition=foo', '--testing', '--output-file', 'abc.def', '-x', 'a1', 'a2']
     >>> optlist, args = getopt.getopt(args, 'x', [
     ...     'condition=', 'output-file=', 'testing'])
     >>> optlist
     [('--condition', 'foo'), ('--testing', ''), ('--output-file', 'abc.def'), ('-x', '')]
     >>> args
     ['a1', 'a2']

Optional arguments should be specified explicitly:

     >>> s = '-Con -C --color=off --color a1 a2'
     >>> args = s.split()
     >>> args
     ['-Con', '-C', '--color=off', '--color', 'a1', 'a2']
     >>> optlist, args = getopt.getopt(args, 'C::', ['color=?'])
     >>> optlist
     [('-C', 'on'), ('-C', ''), ('--color', 'off'), ('--color', '')]
     >>> args
     ['a1', 'a2']

The order of options and non-option arguments can be preserved:

     >>> s = 'a1 -x a2 a3 a4 --long a5 a6'
     >>> args = s.split()
     >>> args
     ['a1', '-x', 'a2', 'a3', 'a4', '--long', 'a5', 'a6']
     >>> optlist, args = getopt.gnu_getopt(args, '-x:', ['long='])
     >>> optlist
     [(None, ['a1']), ('-x', 'a2'), (None, ['a3', 'a4']), ('--long', 'a5')]
     >>> args
     ['a6']

In a script, typical usage is something like this:

     import getopt, sys

     def main():
         try:
             opts, args = getopt.getopt(sys.argv[1:], "ho:v", ["help", "output="])
         except getopt.GetoptError as err:
             # print help information and exit:
             print(err)  # will print something like "option -a not recognized"
             usage()
             sys.exit(2)
         output = None
         verbose = False
         for o, a in opts:
             if o == "-v":
                 verbose = True
             elif o in ("-h", "--help"):
                 usage()
                 sys.exit()
             elif o in ("-o", "--output"):
                 output = a
             else:
                 assert False, "unhandled option"
         process(args, output=output, verbose=verbose)

     if __name__ == "__main__":
         main()

Note that an equivalent command line interface could be produced with
less code and more informative help and error messages by using the
*note optparse: a4. module:

     import optparse

     if __name__ == '__main__':
         parser = optparse.OptionParser()
         parser.add_option('-o', '--output')
         parser.add_option('-v', dest='verbose', action='store_true')
         opts, args = parser.parse_args()
         process(args, output=opts.output, verbose=opts.verbose)

A roughly equivalent command line interface for this case can also be
produced by using the *note argparse: 7. module:

     import argparse

     if __name__ == '__main__':
         parser = argparse.ArgumentParser()
         parser.add_argument('-o', '--output')
         parser.add_argument('-v', dest='verbose', action='store_true')
         parser.add_argument('rest', nargs='*')
         args = parser.parse_args()
         process(args.rest, output=args.output, verbose=args.verbose)

See *note Choosing an argument parsing library: 3351. for details on how
the ‘argparse’ version of this code differs in behaviour from the
‘optparse’ (and ‘getopt’) version.

Vedi anche
..........

Module *note optparse: a4.

     Declarative command line option parsing.

Module *note argparse: 7.

     More opinionated command line option and argument parsing library.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Lib/getopt.py


File: python.info,  Node: Removed Modules,  Next: Security Considerations<3>,  Prev: Superseded Modules,  Up: The Python Standard Library

5.37 Removed Modules
====================

The modules described in this chapter have been removed from the Python
standard library.  They are documented here to help people find
replacements.

* Menu:

* aifc — Read and write AIFF and AIFC files::
* asynchat — Asynchronous socket command/response handler::
* asyncore — Asynchronous socket handler::
* audioop — Manipulate raw audio data::
* cgi — Common Gateway Interface support::
* cgitb — Traceback manager for CGI scripts::
* chunk — Read IFF chunked data::
* crypt — Function to check Unix passwords::
* distutils — Building and installing Python modules::
* imghdr — Determine the type of an image::
* imp — Access the import internals::
* mailcap — Mailcap file handling::
* msilib — Read and write Microsoft Installer files::
* nis — Interface to Sun’s NIS (Yellow Pages): nis — Interface to Sun’s NIS Yellow Pages.
* nntplib — NNTP protocol client::
* ossaudiodev — Access to OSS-compatible audio devices::
* pipes — Interface to shell pipelines::
* smtpd — SMTP Server::
* sndhdr — Determine type of sound file::
* spwd — The shadow password database::
* sunau — Read and write Sun AU files::
* telnetlib — Telnet client::
* uu — Encode and decode uuencode files::
* xdrlib — Encode and decode XDR data::


File: python.info,  Node: aifc — Read and write AIFF and AIFC files,  Next: asynchat — Asynchronous socket command/response handler,  Up: Removed Modules

5.37.1 ‘aifc’ — Read and write AIFF and AIFC files
--------------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

The last version of Python that provided the ‘aifc’ module was Python
3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/aifc.html


File: python.info,  Node: asynchat — Asynchronous socket command/response handler,  Next: asyncore — Asynchronous socket handler,  Prev: aifc — Read and write AIFF and AIFC files,  Up: Removed Modules

5.37.2 ‘asynchat’ — Asynchronous socket command/response handler
----------------------------------------------------------------

Deprecated since version 3.6, removed in version 3.12.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.12: 727. after being deprecated in Python 3.6.
The removal was decided in PEP 594(1).

Applications should use the *note asyncio: b. module instead.

The last version of Python that provided the ‘asynchat’ module was
Python 3.11(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.11/library/asynchat.html


File: python.info,  Node: asyncore — Asynchronous socket handler,  Next: audioop — Manipulate raw audio data,  Prev: asynchat — Asynchronous socket command/response handler,  Up: Removed Modules

5.37.3 ‘asyncore’ — Asynchronous socket handler
-----------------------------------------------

Deprecated since version 3.6, removed in version 3.12.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.12: 727. after being deprecated in Python 3.6.
The removal was decided in PEP 594(1).

Applications should use the *note asyncio: b. module instead.

The last version of Python that provided the ‘asyncore’ module was
Python 3.11(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.11/library/asyncore.html


File: python.info,  Node: audioop — Manipulate raw audio data,  Next: cgi — Common Gateway Interface support,  Prev: asyncore — Asynchronous socket handler,  Up: Removed Modules

5.37.4 ‘audioop’ — Manipulate raw audio data
--------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

The last version of Python that provided the ‘audioop’ module was Python
3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/audioop.html


File: python.info,  Node: cgi — Common Gateway Interface support,  Next: cgitb — Traceback manager for CGI scripts,  Prev: audioop — Manipulate raw audio data,  Up: Removed Modules

5.37.5 ‘cgi’ — Common Gateway Interface support
-----------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

A fork of the module on PyPI can be used instead: legacy-cgi(2).  This
is a copy of the cgi module, no longer maintained or supported by the
core Python team.

The last version of Python that provided the ‘cgi’ module was Python
3.12(3).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://pypi.org/project/legacy-cgi/

   (3) https://docs.python.org/3.12/library/cgi.html


File: python.info,  Node: cgitb — Traceback manager for CGI scripts,  Next: chunk — Read IFF chunked data,  Prev: cgi — Common Gateway Interface support,  Up: Removed Modules

5.37.6 ‘cgitb’ — Traceback manager for CGI scripts
--------------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

A fork of the module on PyPI can now be used instead: legacy-cgi(2).
This is a copy of the cgi module, no longer maintained or supported by
the core Python team.

The last version of Python that provided the ‘cgitb’ module was Python
3.12(3).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://pypi.org/project/legacy-cgi/

   (3) https://docs.python.org/3.12/library/cgitb.html


File: python.info,  Node: chunk — Read IFF chunked data,  Next: crypt — Function to check Unix passwords,  Prev: cgitb — Traceback manager for CGI scripts,  Up: Removed Modules

5.37.7 ‘chunk’ — Read IFF chunked data
--------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

The last version of Python that provided the ‘chunk’ module was Python
3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/chunk.html


File: python.info,  Node: crypt — Function to check Unix passwords,  Next: distutils — Building and installing Python modules,  Prev: chunk — Read IFF chunked data,  Up: Removed Modules

5.37.8 ‘crypt’ — Function to check Unix passwords
-------------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

Applications can use the *note hashlib: 6c. module from the standard
library.  Other possible replacements are third-party libraries from
PyPI: legacycrypt(2), bcrypt(3), or argon2-cffi(4).  These are not
supported or maintained by the Python core team.

The last version of Python that provided the ‘crypt’ module was Python
3.12(5).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://pypi.org/project/legacycrypt/

   (3) https://pypi.org/project/bcrypt/

   (4) https://pypi.org/project/argon2-cffi/

   (5) https://docs.python.org/3.12/library/crypt.html


File: python.info,  Node: distutils — Building and installing Python modules,  Next: imghdr — Determine the type of an image,  Prev: crypt — Function to check Unix passwords,  Up: Removed Modules

5.37.9 ‘distutils’ — Building and installing Python modules
-----------------------------------------------------------

Deprecated since version 3.10, removed in version 3.12.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.12: 72d. after being deprecated in Python
3.10.  The removal was decided in PEP 632(1), which has migration
advice(2).

The last version of Python that provided the ‘distutils’ module was
Python 3.11(3).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0632/

   (2) https://peps.python.org/pep-0632/#migration-advice

   (3) https://docs.python.org/3.11/library/distutils.html


File: python.info,  Node: imghdr — Determine the type of an image,  Next: imp — Access the import internals,  Prev: distutils — Building and installing Python modules,  Up: Removed Modules

5.37.10 ‘imghdr’ — Determine the type of an image
-------------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

Possible replacements are third-party libraries from PyPI: filetype(2),
puremagic(3), or python-magic(4).  These are not supported or maintained
by the Python core team.

The last version of Python that provided the ‘imghdr’ module was Python
3.12(5).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://pypi.org/project/filetype/

   (3) https://pypi.org/project/puremagic/

   (4) https://pypi.org/project/python-magic/

   (5) https://docs.python.org/3.12/library/imghdr.html


File: python.info,  Node: imp — Access the import internals,  Next: mailcap — Mailcap file handling,  Prev: imghdr — Determine the type of an image,  Up: Removed Modules

5.37.11 ‘imp’ — Access the import internals
-------------------------------------------

Deprecated since version 3.4, removed in version 3.12.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.12: 737. after being deprecated in Python 3.4.

The *note removal notice: 737. includes guidance for migrating code from
‘imp’ to *note importlib: 7b.

The last version of Python that provided the ‘imp’ module was Python
3.11(1).

   ---------- Footnotes ----------

   (1) https://docs.python.org/3.11/library/imp.html


File: python.info,  Node: mailcap — Mailcap file handling,  Next: msilib — Read and write Microsoft Installer files,  Prev: imp — Access the import internals,  Up: Removed Modules

5.37.12 ‘mailcap’ — Mailcap file handling
-----------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

The last version of Python that provided the ‘mailcap’ module was Python
3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/mailcap.html


File: python.info,  Node: msilib — Read and write Microsoft Installer files,  Next: nis — Interface to Sun’s NIS Yellow Pages,  Prev: mailcap — Mailcap file handling,  Up: Removed Modules

5.37.13 ‘msilib’ — Read and write Microsoft Installer files
-----------------------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

The last version of Python that provided the ‘msilib’ module was Python
3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/msilib.html


File: python.info,  Node: nis — Interface to Sun’s NIS Yellow Pages,  Next: nntplib — NNTP protocol client,  Prev: msilib — Read and write Microsoft Installer files,  Up: Removed Modules

5.37.14 ‘nis’ — Interface to Sun’s NIS (Yellow Pages)
-----------------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

The last version of Python that provided the ‘nis’ module was Python
3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/nis.html


File: python.info,  Node: nntplib — NNTP protocol client,  Next: ossaudiodev — Access to OSS-compatible audio devices,  Prev: nis — Interface to Sun’s NIS Yellow Pages,  Up: Removed Modules

5.37.15 ‘nntplib’ — NNTP protocol client
----------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

The last version of Python that provided the ‘nntplib’ module was Python
3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/nntplib.html


File: python.info,  Node: ossaudiodev — Access to OSS-compatible audio devices,  Next: pipes — Interface to shell pipelines,  Prev: nntplib — NNTP protocol client,  Up: Removed Modules

5.37.16 ‘ossaudiodev’ — Access to OSS-compatible audio devices
--------------------------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

The last version of Python that provided the ‘ossaudiodev’ module was
Python 3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/ossaudiodev.html


File: python.info,  Node: pipes — Interface to shell pipelines,  Next: smtpd — SMTP Server,  Prev: ossaudiodev — Access to OSS-compatible audio devices,  Up: Removed Modules

5.37.17 ‘pipes’ — Interface to shell pipelines
----------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

Applications should use the *note subprocess: dc. module instead.

The last version of Python that provided the ‘pipes’ module was Python
3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/pipes.html


File: python.info,  Node: smtpd — SMTP Server,  Next: sndhdr — Determine type of sound file,  Prev: pipes — Interface to shell pipelines,  Up: Removed Modules

5.37.18 ‘smtpd’ — SMTP Server
-----------------------------

Deprecated since version 3.6, removed in version 3.12.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.12: 727. after being deprecated in Python 3.6.
The removal was decided in PEP 594(1).

A possible replacement is the third-party aiosmtpd(2) library.  This
library is not maintained or supported by the Python core team.

The last version of Python that provided the ‘smtpd’ module was Python
3.11(3).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://pypi.org/project/aiosmtpd/

   (3) https://docs.python.org/3.11/library/smtpd.html


File: python.info,  Node: sndhdr — Determine type of sound file,  Next: spwd — The shadow password database,  Prev: smtpd — SMTP Server,  Up: Removed Modules

5.37.19 ‘sndhdr’ — Determine type of sound file
-----------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

Possible replacements are third-party modules from PyPI: filetype(2),
puremagic(3), or python-magic(4).  These are not supported or maintained
by the Python core team.

The last version of Python that provided the ‘sndhdr’ module was Python
3.12(5).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://pypi.org/project/filetype/

   (3) https://pypi.org/project/puremagic/

   (4) https://pypi.org/project/python-magic/

   (5) https://docs.python.org/3.12/library/sndhdr.html


File: python.info,  Node: spwd — The shadow password database,  Next: sunau — Read and write Sun AU files,  Prev: sndhdr — Determine type of sound file,  Up: Removed Modules

5.37.20 ‘spwd’ — The shadow password database
---------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

A possible replacement is the third-party library python-pam(2).  This
library is not supported or maintained by the Python core team.

The last version of Python that provided the ‘spwd’ module was Python
3.12(3).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://pypi.org/project/python-pam/

   (3) https://docs.python.org/3.12/library/spwd.html


File: python.info,  Node: sunau — Read and write Sun AU files,  Next: telnetlib — Telnet client,  Prev: spwd — The shadow password database,  Up: Removed Modules

5.37.21 ‘sunau’ — Read and write Sun AU files
---------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

The last version of Python that provided the ‘sunau’ module was Python
3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/sunau.html


File: python.info,  Node: telnetlib — Telnet client,  Next: uu — Encode and decode uuencode files,  Prev: sunau — Read and write Sun AU files,  Up: Removed Modules

5.37.22 ‘telnetlib’ — Telnet client
-----------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

Possible replacements are third-party libraries from PyPI: telnetlib3(2)
or Exscript(3).  These are not supported or maintained by the Python
core team.

The last version of Python that provided the ‘telnetlib’ module was
Python 3.12(4).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://pypi.org/project/telnetlib3/

   (3) https://pypi.org/project/Exscript/

   (4) https://docs.python.org/3.12/library/telnetlib.html


File: python.info,  Node: uu — Encode and decode uuencode files,  Next: xdrlib — Encode and decode XDR data,  Prev: telnetlib — Telnet client,  Up: Removed Modules

5.37.23 ‘uu’ — Encode and decode uuencode files
-----------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

The last version of Python that provided the ‘uu’ module was Python
3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/uu.html


File: python.info,  Node: xdrlib — Encode and decode XDR data,  Prev: uu — Encode and decode uuencode files,  Up: Removed Modules

5.37.24 ‘xdrlib’ — Encode and decode XDR data
---------------------------------------------

Deprecated since version 3.11, removed in version 3.13.

This module is no longer part of the Python standard library.  It was
*note removed in Python 3.13: 471. after being deprecated in Python
3.11.  The removal was decided in PEP 594(1).

The last version of Python that provided the ‘xdrlib’ module was Python
3.12(2).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0594/

   (2) https://docs.python.org/3.12/library/xdrlib.html


File: python.info,  Node: Security Considerations<3>,  Prev: Removed Modules,  Up: The Python Standard Library

5.38 Security Considerations
============================

The following modules have specific security considerations:

   * *note base64: f.: *note base64 security considerations: 3c9c. in
     RFC 4648(1)

   * *note hashlib: 6c.: *note all constructors take a «usedforsecurity»
     keyword-only argument disabling known insecure and blocked
     algorithms: 2fae.

   * *note http.server: 76. is not suitable for production use, only
     implementing basic security checks.  See the *note security
     considerations: 40cf.

   * *note logging: 8b.: *note Logging configuration uses eval(): 3192.

   * *note multiprocessing: 98.: *note Connection.recv() uses pickle:
     366c.

   * *note pickle: ab.: *note Restricting globals in pickle: 2d00.

   * *note random: bd. shouldn’t be used for security purposes, use
     *note secrets: c5. instead

   * *note shelve: c8.: *note shelve is based on pickle and thus
     unsuitable for dealing with untrusted sources: 2d22.

   * *note ssl: d5.: *note SSL/TLS security considerations: 387b.

   * *note subprocess: dc.: *note Subprocess security considerations:
     373c.

   * *note tempfile: e6.: *note mktemp is deprecated due to
     vulnerability to race conditions: 2cba.

   * *note xml: 126.: *note XML security: 3cd0.

   * *note zipfile: 137.: *note maliciously prepared .zip files can
     cause disk volume exhaustion: 2ebe.

The *note -I: b59. command line option can be used to run Python in
isolated mode.  When it cannot be used, the *note -P: 7c2. option or the
*note PYTHONSAFEPATH: 7c3. environment variable can be used to not
prepend a potentially unsafe path to *note sys.path: 3e4. such as the
current directory, the script’s directory or an empty string.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc4648.html


File: python.info,  Node: Extending and Embedding the Python Interpreter,  Next: Python/C API Reference Manual,  Prev: The Python Standard Library,  Up: Top

6 Extending and Embedding the Python Interpreter
************************************************

This document describes how to write modules in C or C++ to extend the
Python interpreter with new modules.  Those modules can not only define
new functions but also new object types and their methods.  The document
also describes how to embed the Python interpreter in another
application, for use as an extension language.  Finally, it shows how to
compile and link extension modules so that they can be loaded
dynamically (at run time) into the interpreter, if the underlying
operating system supports this feature.

This document assumes basic knowledge about Python.  For an informal
introduction to the language, see *note Tutorial su Python: 1fa4.  *note
The Python Language Reference: 14a. gives a more formal definition of
the language.  *note The Python Standard Library: 149. documents the
existing object types, functions and modules (both built-in and written
in Python) that give the language its wide application range.

For a detailed description of the whole Python/C API, see the separate
*note Python/C API Reference Manual: 1fa6.

* Menu:

* Recommended third party tools::
* Creating extensions without third party tools::
* Embedding the CPython runtime in a larger application::


File: python.info,  Node: Recommended third party tools,  Next: Creating extensions without third party tools,  Up: Extending and Embedding the Python Interpreter

6.1 Recommended third party tools
=================================

This guide only covers the basic tools for creating extensions provided
as part of this version of CPython.  Some *note third party tools: 4e77.
offer both simpler and more sophisticated approaches to creating C and
C++ extensions for Python.


File: python.info,  Node: Creating extensions without third party tools,  Next: Embedding the CPython runtime in a larger application,  Prev: Recommended third party tools,  Up: Extending and Embedding the Python Interpreter

6.2 Creating extensions without third party tools
=================================================

This section of the guide covers creating C and C++ extensions without
assistance from third party tools.  It is intended primarily for
creators of those tools, rather than being a recommended way to create
your own C extensions.

Vedi anche
..........

PEP 489(1) – Multi-phase extension module initialization

* Menu:

* Extending Python with C or C++::
* Defining Extension Types; Tutorial: Defining Extension Types Tutorial.
* Defining Extension Types; Assorted Topics: Defining Extension Types Assorted Topics.
* Building C and C++ Extensions::
* Building C and C++ Extensions on Windows::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0489/


File: python.info,  Node: Extending Python with C or C++,  Next: Defining Extension Types Tutorial,  Up: Creating extensions without third party tools

6.2.1 Extending Python with C or C++
------------------------------------

It is quite easy to add new built-in modules to Python, if you know how
to program in C. Such 'extension modules' can do two things that can’t
be done directly in Python: they can implement new built-in object
types, and they can call C library functions and system calls.

To support extensions, the Python API (Application Programmers
Interface) defines a set of functions, macros and variables that provide
access to most aspects of the Python run-time system.  The Python API is
incorporated in a C source file by including the header ‘"Python.h"’.

The compilation of an extension module depends on its intended use as
well as on your system setup; details are given in later chapters.

     Nota: The C extension interface is specific to CPython, and
     extension modules do not work on other Python implementations.  In
     many cases, it is possible to avoid writing C extensions and
     preserve portability to other implementations.  For example, if
     your use case is calling C library functions or system calls, you
     should consider using the *note ctypes: 2e. module or the cffi(1)
     library rather than writing custom C code.  These modules let you
     write Python code to interface with C code and are more portable
     between implementations of Python than writing and compiling a C
     extension module.

* Menu:

* A Simple Example::
* Intermezzo; Errors and Exceptions: Intermezzo Errors and Exceptions.
* Back to the Example::
* The Module’s Method Table and Initialization Function::
* Compilation and Linkage::
* Calling Python Functions from C::
* Extracting Parameters in Extension Functions::
* Keyword Parameters for Extension Functions::
* Building Arbitrary Values::
* Reference Counts::
* Writing Extensions in C++::
* Providing a C API for an Extension Module::

   ---------- Footnotes ----------

   (1) https://cffi.readthedocs.io/


File: python.info,  Node: A Simple Example,  Next: Intermezzo Errors and Exceptions,  Up: Extending Python with C or C++

6.2.1.1 A Simple Example
........................

Let’s create an extension module called ‘spam’ (the favorite food of
Monty Python fans…) and let’s say we want to create a Python interface
to the C library function ‘system()’ (1).  This function takes a
null-terminated character string as argument and returns an integer.  We
want this function to be callable from Python as follows:

     >>> import spam
     >>> status = spam.system("ls -l")

Begin by creating a file ‘spammodule.c’.  (Historically, if a module is
called ‘spam’, the C file containing its implementation is called
‘spammodule.c’; if the module name is very long, like ‘spammify’, the
module name can be just ‘spammify.c’.)

The first two lines of our file can be:

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>

which pulls in the Python API (you can add a comment describing the
purpose of the module and a copyright notice if you like).

     Nota: Since Python may define some pre-processor definitions which
     affect the standard headers on some systems, you 'must' include
     ‘Python.h’ before any standard headers are included.

     ‘#define PY_SSIZE_T_CLEAN’ was used to indicate that ‘Py_ssize_t’
     should be used in some APIs instead of ‘int’.  It is not necessary
     since Python 3.13, but we keep it here for backward compatibility.
     See *note Strings and buffers: 62c. for a description of this
     macro.

All user-visible symbols defined by ‘Python.h’ have a prefix of ‘Py’ or
‘PY’, except those defined in standard header files.

     Suggerimento: For backward compatibility, ‘Python.h’ includes
     several standard header files.  C extensions should include the
     standard headers that they use, and should not rely on these
     implicit includes.  If using the limited C API version 3.13 or
     newer, the implicit includes are:

        * ‘<assert.h>’

        * ‘<intrin.h>’ (on Windows)

        * ‘<inttypes.h>’

        * ‘<limits.h>’

        * ‘<math.h>’

        * ‘<stdarg.h>’

        * ‘<wchar.h>’

        * ‘<sys/types.h>’ (if present)

     If *note Py_LIMITED_API: 660. is not defined, or is set to version
     3.12 or older, the headers below are also included:

        * ‘<ctype.h>’

        * ‘<unistd.h>’ (on POSIX)

     If *note Py_LIMITED_API: 660. is not defined, or is set to version
     3.10 or older, the headers below are also included:

        * ‘<errno.h>’

        * ‘<stdio.h>’

        * ‘<stdlib.h>’

        * ‘<string.h>’

The next thing we add to our module file is the C function that will be
called when the Python expression ‘spam.system(string)’ is evaluated
(we’ll see shortly how it ends up being called):

     static PyObject *
     spam_system(PyObject *self, PyObject *args)
     {
         const char *command;
         int sts;

         if (!PyArg_ParseTuple(args, "s", &command))
             return NULL;
         sts = system(command);
         return PyLong_FromLong(sts);
     }

There is a straightforward translation from the argument list in Python
(for example, the single expression ‘"ls -l"’) to the arguments passed
to the C function.  The C function always has two arguments,
conventionally named 'self' and 'args'.

The 'self' argument points to the module object for module-level
functions; for a method it would point to the object instance.

The 'args' argument will be a pointer to a Python tuple object
containing the arguments.  Each item of the tuple corresponds to an
argument in the call’s argument list.  The arguments are Python objects
— in order to do anything with them in our C function we have to convert
them to C values.  The function *note PyArg_ParseTuple(): 3c1. in the
Python API checks the argument types and converts them to C values.  It
uses a template string to determine the required types of the arguments
as well as the types of the C variables into which to store the
converted values.  More about this later.

*note PyArg_ParseTuple(): 3c1. returns true (nonzero) if all arguments
have the right type and its components have been stored in the variables
whose addresses are passed.  It returns false (zero) if an invalid
argument list was passed.  In the latter case it also raises an
appropriate exception so the calling function can return ‘NULL’
immediately (as we saw in the example).

   ---------- Footnotes ----------

   (1) An interface for this function already exists in the standard
module *note os: a5. — it was chosen as a simple and straightforward
example.


File: python.info,  Node: Intermezzo Errors and Exceptions,  Next: Back to the Example,  Prev: A Simple Example,  Up: Extending Python with C or C++

6.2.1.2 Intermezzo: Errors and Exceptions
.........................................

An important convention throughout the Python interpreter is the
following: when a function fails, it should set an exception condition
and return an error value (usually ‘-1’ or a ‘NULL’ pointer).  Exception
information is stored in three members of the interpreter’s thread
state.  These are ‘NULL’ if there is no exception.  Otherwise they are
the C equivalents of the members of the Python tuple returned by *note
sys.exc_info(): 89b.  These are the exception type, exception instance,
and a traceback object.  It is important to know about them to
understand how errors are passed around.

The Python API defines a number of functions to set various types of
exceptions.

The most common one is *note PyErr_SetString(): 79d.  Its arguments are
an exception object and a C string.  The exception object is usually a
predefined object like *note PyExc_ZeroDivisionError: 4e80.  The C
string indicates the cause of the error and is converted to a Python
string object and stored as the «associated value» of the exception.

Another useful function is *note PyErr_SetFromErrno(): 4e81, which only
takes an exception argument and constructs the associated value by
inspection of the global variable ‘errno’.  The most general function is
*note PyErr_SetObject(): 79c, which takes two object arguments, the
exception and its associated value.  You don’t need to *note
Py_INCREF(): 790. the objects passed to any of these functions.

You can test non-destructively whether an exception has been set with
*note PyErr_Occurred(): 1c97.  This returns the current exception
object, or ‘NULL’ if no exception has occurred.  You normally don’t need
to call *note PyErr_Occurred(): 1c97. to see whether an error occurred
in a function call, since you should be able to tell from the return
value.

When a function 'f' that calls another function 'g' detects that the
latter fails, 'f' should itself return an error value (usually ‘NULL’ or
‘-1’).  It should 'not' call one of the ‘PyErr_*’ functions — one has
already been called by 'g'.  'f'’s caller is then supposed to also
return an error indication to 'its' caller, again 'without' calling
‘PyErr_*’, and so on — the most detailed cause of the error was already
reported by the function that first detected it.  Once the error reaches
the Python interpreter’s main loop, this aborts the currently executing
Python code and tries to find an exception handler specified by the
Python programmer.

(There are situations where a module can actually give a more detailed
error message by calling another ‘PyErr_*’ function, and in such cases
it is fine to do so.  As a general rule, however, this is not necessary,
and can cause information about the cause of the error to be lost: most
operations can fail for a variety of reasons.)

To ignore an exception set by a function call that failed, the exception
condition must be cleared explicitly by calling *note PyErr_Clear():
1233.  The only time C code should call *note PyErr_Clear(): 1233. is if
it doesn’t want to pass the error on to the interpreter but wants to
handle it completely by itself (possibly by trying something else, or
pretending nothing went wrong).

Every failing ‘malloc()’ call must be turned into an exception — the
direct caller of ‘malloc()’ (or ‘realloc()’) must call *note
PyErr_NoMemory(): 4e82. and return a failure indicator itself.  All the
object-creating functions (for example, *note PyLong_FromLong(): 1bb8.)
already do this, so this note is only relevant to those who call
‘malloc()’ directly.

Also note that, with the important exception of *note
PyArg_ParseTuple(): 3c1. and friends, functions that return an integer
status usually return a positive value or zero for success and ‘-1’ for
failure, like Unix system calls.

Finally, be careful to clean up garbage (by making *note Py_XDECREF():
993. or *note Py_DECREF(): 791. calls for objects you have already
created) when you return an error indicator!

The choice of which exception to raise is entirely yours.  There are
predeclared C objects corresponding to all built-in Python exceptions,
such as *note PyExc_ZeroDivisionError: 4e80, which you can use directly.
Of course, you should choose exceptions wisely — don’t use *note
PyExc_TypeError: 4e83. to mean that a file couldn’t be opened (that
should probably be *note PyExc_OSError: 4e84.).  If something’s wrong
with the argument list, the *note PyArg_ParseTuple(): 3c1. function
usually raises *note PyExc_TypeError: 4e83.  If you have an argument
whose value must be in a particular range or must satisfy other
conditions, *note PyExc_ValueError: 4e85. is appropriate.

You can also define a new exception that is unique to your module.  The
simplest way to do this is to declare a static global object variable at
the beginning of the file:

     static PyObject *SpamError = NULL;

and initialize it by calling *note PyErr_NewException(): 1471. in the
module’s *note Py_mod_exec: b77. function (‘spam_module_exec()’):

     SpamError = PyErr_NewException("spam.error", NULL, NULL);

Since ‘SpamError’ is a global variable, it will be overwritten every
time the module is reinitialized, when the *note Py_mod_exec: b77.
function is called.

For now, let’s avoid the issue: we will block repeated initialization by
raising an *note ImportError: 65b.:

     static PyObject *SpamError = NULL;

     static int
     spam_module_exec(PyObject *m)
     {
         if (SpamError != NULL) {
             PyErr_SetString(PyExc_ImportError,
                             "cannot initialize spam module more than once");
             return -1;
         }
         SpamError = PyErr_NewException("spam.error", NULL, NULL);
         if (PyModule_AddObjectRef(m, "SpamError", SpamError) < 0) {
             return -1;
         }

         return 0;
     }

     static PyModuleDef_Slot spam_module_slots[] = {
         {Py_mod_exec, spam_module_exec},
         {0, NULL}
     };

     static struct PyModuleDef spam_module = {
         .m_base = PyModuleDef_HEAD_INIT,
         .m_name = "spam",
         .m_size = 0,  // non-negative
         .m_slots = spam_module_slots,
     };

     PyMODINIT_FUNC
     PyInit_spam(void)
     {
         return PyModuleDef_Init(&spam_module);
     }

Note that the Python name for the exception object is ‘spam.error’.  The
*note PyErr_NewException(): 1471. function may create a class with the
base class being *note Exception: bcf. (unless another class is passed
in instead of ‘NULL’), described in *note Built-in Exceptions: 1c0f.

Note also that the ‘SpamError’ variable retains a reference to the newly
created exception class; this is intentional!  Since the exception could
be removed from the module by external code, an owned reference to the
class is needed to ensure that it will not be discarded, causing
‘SpamError’ to become a dangling pointer.  Should it become a dangling
pointer, C code which raises the exception could cause a core dump or
other unintended side effects.

For now, the *note Py_DECREF(): 791. call to remove this reference is
missing.  Even when the Python interpreter shuts down, the global
‘SpamError’ variable will not be garbage-collected.  It will «leak».  We
did, however, ensure that this will happen at most once per process.

We discuss the use of *note PyMODINIT_FUNC: 16da. as a function return
type later in this sample.

The ‘spam.error’ exception can be raised in your extension module using
a call to *note PyErr_SetString(): 79d. as shown below:

     static PyObject *
     spam_system(PyObject *self, PyObject *args)
     {
         const char *command;
         int sts;

         if (!PyArg_ParseTuple(args, "s", &command))
             return NULL;
         sts = system(command);
         if (sts < 0) {
             PyErr_SetString(SpamError, "System command failed");
             return NULL;
         }
         return PyLong_FromLong(sts);
     }


File: python.info,  Node: Back to the Example,  Next: The Module’s Method Table and Initialization Function,  Prev: Intermezzo Errors and Exceptions,  Up: Extending Python with C or C++

6.2.1.3 Back to the Example
...........................

Going back to our example function, you should now be able to understand
this statement:

     if (!PyArg_ParseTuple(args, "s", &command))
         return NULL;

It returns ‘NULL’ (the error indicator for functions returning object
pointers) if an error is detected in the argument list, relying on the
exception set by *note PyArg_ParseTuple(): 3c1.  Otherwise the string
value of the argument has been copied to the local variable ‘command’.
This is a pointer assignment and you are not supposed to modify the
string to which it points (so in Standard C, the variable ‘command’
should properly be declared as ‘const char *command’).

The next statement is a call to the Unix function ‘system()’, passing it
the string we just got from *note PyArg_ParseTuple(): 3c1.:

     sts = system(command);

Our ‘spam.system()’ function must return the value of ‘sts’ as a Python
object.  This is done using the function *note PyLong_FromLong(): 1bb8.

     return PyLong_FromLong(sts);

In this case, it will return an integer object.  (Yes, even integers are
objects on the heap in Python!)

If you have a C function that returns no useful argument (a function
returning void), the corresponding Python function must return ‘None’.
You need this idiom to do so (which is implemented by the *note
Py_RETURN_NONE: 167a. macro):

     Py_INCREF(Py_None);
     return Py_None;

*note Py_None: 4e88. is the C name for the special Python object ‘None’.
It is a genuine Python object rather than a ‘NULL’ pointer, which means
«error» in most contexts, as we have seen.


File: python.info,  Node: The Module’s Method Table and Initialization Function,  Next: Compilation and Linkage,  Prev: Back to the Example,  Up: Extending Python with C or C++

6.2.1.4 The Module’s Method Table and Initialization Function
.............................................................

I promised to show how ‘spam_system()’ is called from Python programs.
First, we need to list its name and address in a «method table»:

     static PyMethodDef spam_methods[] = {
         ...
         {"system",  spam_system, METH_VARARGS,
          "Execute a shell command."},
         ...
         {NULL, NULL, 0, NULL}        /* Sentinel */
     };

Note the third entry (‘METH_VARARGS’).  This is a flag telling the
interpreter the calling convention to be used for the C function.  It
should normally always be ‘METH_VARARGS’ or ‘METH_VARARGS |
METH_KEYWORDS’; a value of ‘0’ means that an obsolete variant of *note
PyArg_ParseTuple(): 3c1. is used.

When using only ‘METH_VARARGS’, the function should expect the
Python-level parameters to be passed in as a tuple acceptable for
parsing via *note PyArg_ParseTuple(): 3c1.; more information on this
function is provided below.

The *note METH_KEYWORDS: 4e8b. bit may be set in the third field if
keyword arguments should be passed to the function.  In this case, the C
function should accept a third ‘PyObject *’ parameter which will be a
dictionary of keywords.  Use *note PyArg_ParseTupleAndKeywords(): 624.
to parse the arguments to such a function.

The method table must be referenced in the module definition structure:

     static struct PyModuleDef spam_module = {
         ...
         .m_methods = spam_methods,
         ...
     };

This structure, in turn, must be passed to the interpreter in the
module’s initialization function.  The initialization function must be
named ‘PyInit_name()’, where 'name' is the name of the module, and
should be the only non-‘static’ item defined in the module file:

     PyMODINIT_FUNC
     PyInit_spam(void)
     {
         return PyModuleDef_Init(&spam_module);
     }

Note that *note PyMODINIT_FUNC: 16da. declares the function as ‘PyObject
*’ return type, declares any special linkage declarations required by
the platform, and for C++ declares the function as ‘extern "C"’.

‘PyInit_spam()’ is called when each interpreter imports its module
‘spam’ for the first time.  (See below for comments about embedding
Python.)  A pointer to the module definition must be returned via *note
PyModuleDef_Init(): 4e8c, so that the import machinery can create the
module and store it in ‘sys.modules’.

When embedding Python, the ‘PyInit_spam()’ function is not called
automatically unless there’s an entry in the *note PyImport_Inittab:
1b03. table.  To add the module to the initialization table, use *note
PyImport_AppendInittab(): 1b04, optionally followed by an import of the
module:

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>

     int
     main(int argc, char *argv[])
     {
         PyStatus status;
         PyConfig config;
         PyConfig_InitPythonConfig(&config);

         /* Add a built-in module, before Py_Initialize */
         if (PyImport_AppendInittab("spam", PyInit_spam) == -1) {
             fprintf(stderr, "Error: could not extend in-built modules table\n");
             exit(1);
         }

         /* Pass argv[0] to the Python interpreter */
         status = PyConfig_SetBytesString(&config, &config.program_name, argv[0]);
         if (PyStatus_Exception(status)) {
             goto exception;
         }

         /* Initialize the Python interpreter.  Required.
            If this step fails, it will be a fatal error. */
         status = Py_InitializeFromConfig(&config);
         if (PyStatus_Exception(status)) {
             goto exception;
         }
         PyConfig_Clear(&config);

         /* Optionally import the module; alternatively,
            import can be deferred until the embedded script
            imports it. */
         PyObject *pmodule = PyImport_ImportModule("spam");
         if (!pmodule) {
             PyErr_Print();
             fprintf(stderr, "Error: could not import module 'spam'\n");
         }

         // ... use Python C API here ...

         return 0;

       exception:
          PyConfig_Clear(&config);
          Py_ExitStatusException(status);
     }

     Nota: If you declare a global variable or a local static one, the
     module may experience unintended side-effects on re-initialisation,
     for example when removing entries from ‘sys.modules’ or importing
     compiled modules into multiple interpreters within a process (or
     following a ‘fork()’ without an intervening ‘exec()’).  If module
     state is not yet fully *note isolated: 166, authors should consider
     marking the module as having no support for subinterpreters (via
     *note Py_MOD_MULTIPLE_INTERPRETERS_NOT_SUPPORTED: 4e8d.).

A more substantial example module is included in the Python source
distribution as ‘Modules/xxlimited.c’.  This file may be used as a
template or simply read as an example.


File: python.info,  Node: Compilation and Linkage,  Next: Calling Python Functions from C,  Prev: The Module’s Method Table and Initialization Function,  Up: Extending Python with C or C++

6.2.1.5 Compilation and Linkage
...............................

There are two more things to do before you can use your new extension:
compiling and linking it with the Python system.  If you use dynamic
loading, the details may depend on the style of dynamic loading your
system uses; see the chapters about building extension modules (chapter
*note Building C and C++ Extensions: 4e90.) and additional information
that pertains only to building on Windows (chapter *note Building C and
C++ Extensions on Windows: 220d.) for more information about this.

If you can’t use dynamic loading, or if you want to make your module a
permanent part of the Python interpreter, you will have to change the
configuration setup and rebuild the interpreter.  Luckily, this is very
simple on Unix: just place your file (‘spammodule.c’ for example) in the
‘Modules/’ directory of an unpacked source distribution, add a line to
the file ‘Modules/Setup.local’ describing your file:

     spam spammodule.o

and rebuild the interpreter by running ‘make’ in the toplevel directory.
You can also run ‘make’ in the ‘Modules/’ subdirectory, but then you
must first rebuild ‘Makefile’ there by running “‘make’ Makefile”.  (This
is necessary each time you change the ‘Setup’ file.)

If your module requires additional libraries to link with, these can be
listed on the line in the configuration file as well, for instance:

     spam spammodule.o -lX11


File: python.info,  Node: Calling Python Functions from C,  Next: Extracting Parameters in Extension Functions,  Prev: Compilation and Linkage,  Up: Extending Python with C or C++

6.2.1.6 Calling Python Functions from C
.......................................

So far we have concentrated on making C functions callable from Python.
The reverse is also useful: calling Python functions from C. This is
especially the case for libraries that support so-called «callback»
functions.  If a C interface makes use of callbacks, the equivalent
Python often needs to provide a callback mechanism to the Python
programmer; the implementation will require calling the Python callback
functions from a C callback.  Other uses are also imaginable.

Fortunately, the Python interpreter is easily called recursively, and
there is a standard interface to call a Python function.  (I won’t dwell
on how to call the Python parser with a particular string as input — if
you’re interested, have a look at the implementation of the *note -c:
1a8. command line option in ‘Modules/main.c’ from the Python source
code.)

Calling a Python function is easy.  First, the Python program must
somehow pass you the Python function object.  You should provide a
function (or some other interface) to do this.  When this function is
called, save a pointer to the Python function object (be careful to
*note Py_INCREF(): 790. it!)  in a global variable — or wherever you see
fit.  For example, the following function might be part of a module
definition:

     static PyObject *my_callback = NULL;

     static PyObject *
     my_set_callback(PyObject *dummy, PyObject *args)
     {
         PyObject *result = NULL;
         PyObject *temp;

         if (PyArg_ParseTuple(args, "O:set_callback", &temp)) {
             if (!PyCallable_Check(temp)) {
                 PyErr_SetString(PyExc_TypeError, "parameter must be callable");
                 return NULL;
             }
             Py_XINCREF(temp);         /* Add a reference to new callback */
             Py_XDECREF(my_callback);  /* Dispose of previous callback */
             my_callback = temp;       /* Remember new callback */
             /* Boilerplate to return "None" */
             Py_INCREF(Py_None);
             result = Py_None;
         }
         return result;
     }

This function must be registered with the interpreter using the *note
METH_VARARGS: 170f. flag; this is described in section *note The
Module’s Method Table and Initialization Function: 4e89.  The *note
PyArg_ParseTuple(): 3c1. function and its arguments are documented in
section *note Extracting Parameters in Extension Functions: 4e93.

The macros *note Py_XINCREF(): c5c. and *note Py_XDECREF(): 993.
increment/decrement the reference count of an object and are safe in the
presence of ‘NULL’ pointers (but note that 'temp' will not be ‘NULL’ in
this context).  More info on them in section *note Reference Counts:
4e94.

Later, when it is time to call the function, you call the C function
*note PyObject_CallObject(): 4e95.  This function has two arguments,
both pointers to arbitrary Python objects: the Python function, and the
argument list.  The argument list must always be a tuple object, whose
length is the number of arguments.  To call the Python function with no
arguments, pass in ‘NULL’, or an empty tuple; to call it with one
argument, pass a singleton tuple.  *note Py_BuildValue(): 3c2. returns a
tuple when its format string consists of zero or more format codes
between parentheses.  For example:

     int arg;
     PyObject *arglist;
     PyObject *result;
     ...
     arg = 123;
     ...
     /* Time to call the callback */
     arglist = Py_BuildValue("(i)", arg);
     result = PyObject_CallObject(my_callback, arglist);
     Py_DECREF(arglist);

*note PyObject_CallObject(): 4e95. returns a Python object pointer: this
is the return value of the Python function.  *note
PyObject_CallObject(): 4e95. is «reference-count-neutral» with respect
to its arguments.  In the example a new tuple was created to serve as
the argument list, which is *note Py_DECREF(): 791.-ed immediately after
the *note PyObject_CallObject(): 4e95. call.

The return value of *note PyObject_CallObject(): 4e95. is «new»: either
it is a brand new object, or it is an existing object whose reference
count has been incremented.  So, unless you want to save it in a global
variable, you should somehow *note Py_DECREF(): 791. the result, even
(especially!)  if you are not interested in its value.

Before you do this, however, it is important to check that the return
value isn’t ‘NULL’.  If it is, the Python function terminated by raising
an exception.  If the C code that called *note PyObject_CallObject():
4e95. is called from Python, it should now return an error indication to
its Python caller, so the interpreter can print a stack trace, or the
calling Python code can handle the exception.  If this is not possible
or desirable, the exception should be cleared by calling *note
PyErr_Clear(): 1233.  For example:

     if (result == NULL)
         return NULL; /* Pass error back */
     ...use result...
     Py_DECREF(result);

Depending on the desired interface to the Python callback function, you
may also have to provide an argument list to *note
PyObject_CallObject(): 4e95.  In some cases the argument list is also
provided by the Python program, through the same interface that
specified the callback function.  It can then be saved and used in the
same manner as the function object.  In other cases, you may have to
construct a new tuple to pass as the argument list.  The simplest way to
do this is to call *note Py_BuildValue(): 3c2.  For example, if you want
to pass an integral event code, you might use the following code:

     PyObject *arglist;
     ...
     arglist = Py_BuildValue("(l)", eventcode);
     result = PyObject_CallObject(my_callback, arglist);
     Py_DECREF(arglist);
     if (result == NULL)
         return NULL; /* Pass error back */
     /* Here maybe use the result */
     Py_DECREF(result);

Note the placement of ‘Py_DECREF(arglist)’ immediately after the call,
before the error check!  Also note that strictly speaking this code is
not complete: *note Py_BuildValue(): 3c2. may run out of memory, and
this should be checked.

You may also call a function with keyword arguments by using *note
PyObject_Call(): 63d, which supports arguments and keyword arguments.
As in the above example, we use *note Py_BuildValue(): 3c2. to construct
the dictionary.

     PyObject *dict;
     ...
     dict = Py_BuildValue("{s:i}", "name", val);
     result = PyObject_Call(my_callback, NULL, dict);
     Py_DECREF(dict);
     if (result == NULL)
         return NULL; /* Pass error back */
     /* Here maybe use the result */
     Py_DECREF(result);


File: python.info,  Node: Extracting Parameters in Extension Functions,  Next: Keyword Parameters for Extension Functions,  Prev: Calling Python Functions from C,  Up: Extending Python with C or C++

6.2.1.7 Extracting Parameters in Extension Functions
....................................................

The *note PyArg_ParseTuple(): 3c1. function is declared as follows:

     int PyArg_ParseTuple(PyObject *arg, const char *format, ...);

The 'arg' argument must be a tuple object containing an argument list
passed from Python to a C function.  The 'format' argument must be a
format string, whose syntax is explained in *note Parsing arguments and
building values: 3d5. in the Python/C API Reference Manual.  The
remaining arguments must be addresses of variables whose type is
determined by the format string.

Note that while *note PyArg_ParseTuple(): 3c1. checks that the Python
arguments have the required types, it cannot check the validity of the
addresses of C variables passed to the call: if you make mistakes there,
your code will probably crash or at least overwrite random bits in
memory.  So be careful!

Note that any Python object references which are provided to the caller
are 'borrowed' references; do not decrement their reference count!

Some example calls:

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>

     int ok;
     int i, j;
     long k, l;
     const char *s;
     Py_ssize_t size;

     ok = PyArg_ParseTuple(args, ""); /* No arguments */
         /* Python call: f() */

     ok = PyArg_ParseTuple(args, "s", &s); /* A string */
         /* Possible Python call: f('whoops!') */

     ok = PyArg_ParseTuple(args, "lls", &k, &l, &s); /* Two longs and a string */
         /* Possible Python call: f(1, 2, 'three') */

     ok = PyArg_ParseTuple(args, "(ii)s#", &i, &j, &s, &size);
         /* A pair of ints and a string, whose size is also returned */
         /* Possible Python call: f((1, 2), 'three') */

     {
         const char *file;
         const char *mode = "r";
         int bufsize = 0;
         ok = PyArg_ParseTuple(args, "s|si", &file, &mode, &bufsize);
         /* A string, and optionally another string and an integer */
         /* Possible Python calls:
            f('spam')
            f('spam', 'w')
            f('spam', 'wb', 100000) */
     }

     {
         int left, top, right, bottom, h, v;
         ok = PyArg_ParseTuple(args, "((ii)(ii))(ii)",
                  &left, &top, &right, &bottom, &h, &v);
         /* A rectangle and a point */
         /* Possible Python call:
            f(((0, 0), (400, 300)), (10, 10)) */
     }

     {
         Py_complex c;
         ok = PyArg_ParseTuple(args, "D:myfunction", &c);
         /* a complex, also providing a function name for errors */
         /* Possible Python call: myfunction(1+2j) */
     }


File: python.info,  Node: Keyword Parameters for Extension Functions,  Next: Building Arbitrary Values,  Prev: Extracting Parameters in Extension Functions,  Up: Extending Python with C or C++

6.2.1.8 Keyword Parameters for Extension Functions
..................................................

The *note PyArg_ParseTupleAndKeywords(): 624. function is declared as
follows:

     int PyArg_ParseTupleAndKeywords(PyObject *arg, PyObject *kwdict,
                                     const char *format, char * const *kwlist, ...);

The 'arg' and 'format' parameters are identical to those of the *note
PyArg_ParseTuple(): 3c1. function.  The 'kwdict' parameter is the
dictionary of keywords received as the third parameter from the Python
runtime.  The 'kwlist' parameter is a ‘NULL’-terminated list of strings
which identify the parameters; the names are matched with the type
information from 'format' from left to right.  On success, *note
PyArg_ParseTupleAndKeywords(): 624. returns true, otherwise it returns
false and raises an appropriate exception.

     Nota: Nested tuples cannot be parsed when using keyword arguments!
     Keyword parameters passed in which are not present in the 'kwlist'
     will cause *note TypeError: 198. to be raised.

Here is an example module which uses keywords, based on an example by
Geoff Philbrick (<philbrick@hks.com>):

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>

     static PyObject *
     keywdarg_parrot(PyObject *self, PyObject *args, PyObject *keywds)
     {
         int voltage;
         const char *state = "a stiff";
         const char *action = "voom";
         const char *type = "Norwegian Blue";

         static char *kwlist[] = {"voltage", "state", "action", "type", NULL};

         if (!PyArg_ParseTupleAndKeywords(args, keywds, "i|sss", kwlist,
                                          &voltage, &state, &action, &type))
             return NULL;

         printf("-- This parrot wouldn't %s if you put %i Volts through it.\n",
                action, voltage);
         printf("-- Lovely plumage, the %s -- It's %s!\n", type, state);

         Py_RETURN_NONE;
     }

     static PyMethodDef keywdarg_methods[] = {
         /* The cast of the function is necessary since PyCFunction values
          * only take two PyObject* parameters, and keywdarg_parrot() takes
          * three.
          */
         {"parrot", (PyCFunction)(void(*)(void))keywdarg_parrot, METH_VARARGS | METH_KEYWORDS,
          "Print a lovely skit to standard output."},
         {NULL, NULL, 0, NULL}   /* sentinel */
     };

     static struct PyModuleDef keywdarg_module = {
         .m_base = PyModuleDef_HEAD_INIT,
         .m_name = "keywdarg",
         .m_size = 0,
         .m_methods = keywdarg_methods,
     };

     PyMODINIT_FUNC
     PyInit_keywdarg(void)
     {
         return PyModuleDef_Init(&keywdarg_module);
     }


File: python.info,  Node: Building Arbitrary Values,  Next: Reference Counts,  Prev: Keyword Parameters for Extension Functions,  Up: Extending Python with C or C++

6.2.1.9 Building Arbitrary Values
.................................

This function is the counterpart to *note PyArg_ParseTuple(): 3c1.  It
is declared as follows:

     PyObject *Py_BuildValue(const char *format, ...);

It recognizes a set of format units similar to the ones recognized by
*note PyArg_ParseTuple(): 3c1, but the arguments (which are input to the
function, not output) must not be pointers, just values.  It returns a
new Python object, suitable for returning from a C function called from
Python.

One difference with *note PyArg_ParseTuple(): 3c1.: while the latter
requires its first argument to be a tuple (since Python argument lists
are always represented as tuples internally), *note Py_BuildValue():
3c2. does not always build a tuple.  It builds a tuple only if its
format string contains two or more format units.  If the format string
is empty, it returns ‘None’; if it contains exactly one format unit, it
returns whatever object is described by that format unit.  To force it
to return a tuple of size 0 or one, parenthesize the format string.

Examples (to the left the call, to the right the resulting Python
value):

     Py_BuildValue("")                        None
     Py_BuildValue("i", 123)                  123
     Py_BuildValue("iii", 123, 456, 789)      (123, 456, 789)
     Py_BuildValue("s", "hello")              'hello'
     Py_BuildValue("y", "hello")              b'hello'
     Py_BuildValue("ss", "hello", "world")    ('hello', 'world')
     Py_BuildValue("s#", "hello", 4)          'hell'
     Py_BuildValue("y#", "hello", 4)          b'hell'
     Py_BuildValue("()")                      ()
     Py_BuildValue("(i)", 123)                (123,)
     Py_BuildValue("(ii)", 123, 456)          (123, 456)
     Py_BuildValue("(i,i)", 123, 456)         (123, 456)
     Py_BuildValue("[i,i]", 123, 456)         [123, 456]
     Py_BuildValue("{s:i,s:i}",
                   "abc", 123, "def", 456)    {'abc': 123, 'def': 456}
     Py_BuildValue("((ii)(ii)) (ii)",
                   1, 2, 3, 4, 5, 6)          (((1, 2), (3, 4)), (5, 6))


File: python.info,  Node: Reference Counts,  Next: Writing Extensions in C++,  Prev: Building Arbitrary Values,  Up: Extending Python with C or C++

6.2.1.10 Reference Counts
.........................

In languages like C or C++, the programmer is responsible for dynamic
allocation and deallocation of memory on the heap.  In C, this is done
using the functions ‘malloc()’ and ‘free()’.  In C++, the operators
‘new’ and ‘delete’ are used with essentially the same meaning and we’ll
restrict the following discussion to the C case.

Every block of memory allocated with ‘malloc()’ should eventually be
returned to the pool of available memory by exactly one call to
‘free()’.  It is important to call ‘free()’ at the right time.  If a
block’s address is forgotten but ‘free()’ is not called for it, the
memory it occupies cannot be reused until the program terminates.  This
is called a 'memory leak'.  On the other hand, if a program calls
‘free()’ for a block and then continues to use the block, it creates a
conflict with reuse of the block through another ‘malloc()’ call.  This
is called 'using freed memory'.  It has the same bad consequences as
referencing uninitialized data — core dumps, wrong results, mysterious
crashes.

Common causes of memory leaks are unusual paths through the code.  For
instance, a function may allocate a block of memory, do some
calculation, and then free the block again.  Now a change in the
requirements for the function may add a test to the calculation that
detects an error condition and can return prematurely from the function.
It’s easy to forget to free the allocated memory block when taking this
premature exit, especially when it is added later to the code.  Such
leaks, once introduced, often go undetected for a long time: the error
exit is taken only in a small fraction of all calls, and most modern
machines have plenty of virtual memory, so the leak only becomes
apparent in a long-running process that uses the leaking function
frequently.  Therefore, it’s important to prevent leaks from happening
by having a coding convention or strategy that minimizes this kind of
errors.

Since Python makes heavy use of ‘malloc()’ and ‘free()’, it needs a
strategy to avoid memory leaks as well as the use of freed memory.  The
chosen method is called 'reference counting'.  The principle is simple:
every object contains a counter, which is incremented when a reference
to the object is stored somewhere, and which is decremented when a
reference to it is deleted.  When the counter reaches zero, the last
reference to the object has been deleted and the object is freed.

An alternative strategy is called 'automatic garbage collection'.
(Sometimes, reference counting is also referred to as a garbage
collection strategy, hence my use of «automatic» to distinguish the
two.)  The big advantage of automatic garbage collection is that the
user doesn’t need to call ‘free()’ explicitly.  (Another claimed
advantage is an improvement in speed or memory usage — this is no hard
fact however.)  The disadvantage is that for C, there is no truly
portable automatic garbage collector, while reference counting can be
implemented portably (as long as the functions ‘malloc()’ and ‘free()’
are available — which the C Standard guarantees).  Maybe some day a
sufficiently portable automatic garbage collector will be available for
C. Until then, we’ll have to live with reference counts.

While Python uses the traditional reference counting implementation, it
also offers a cycle detector that works to detect reference cycles.
This allows applications to not worry about creating direct or indirect
circular references; these are the weakness of garbage collection
implemented using only reference counting.  Reference cycles consist of
objects which contain (possibly indirect) references to themselves, so
that each object in the cycle has a reference count which is non-zero.
Typical reference counting implementations are not able to reclaim the
memory belonging to any objects in a reference cycle, or referenced from
the objects in the cycle, even though there are no further references to
the cycle itself.

The cycle detector is able to detect garbage cycles and can reclaim
them.  The *note gc: 64. module exposes a way to run the detector (the
*note collect(): 1b3. function), as well as configuration interfaces and
the ability to disable the detector at runtime.

* Menu:

* Reference Counting in Python::
* Ownership Rules::
* Thin Ice::
* NULL Pointers::


File: python.info,  Node: Reference Counting in Python,  Next: Ownership Rules,  Up: Reference Counts

6.2.1.11 Reference Counting in Python
.....................................

There are two macros, ‘Py_INCREF(x)’ and ‘Py_DECREF(x)’, which handle
the incrementing and decrementing of the reference count.  *note
Py_DECREF(): 791. also frees the object when the count reaches zero.
For flexibility, it doesn’t call ‘free()’ directly — rather, it makes a
call through a function pointer in the object’s 'type object'.  For this
purpose (and others), every object also contains a pointer to its type
object.

The big question now remains: when to use ‘Py_INCREF(x)’ and
‘Py_DECREF(x)’?  Let’s first introduce some terms.  Nobody «owns» an
object; however, you can 'own a reference' to an object.  An object’s
reference count is now defined as the number of owned references to it.
The owner of a reference is responsible for calling *note Py_DECREF():
791. when the reference is no longer needed.  Ownership of a reference
can be transferred.  There are three ways to dispose of an owned
reference: pass it on, store it, or call *note Py_DECREF(): 791.
Forgetting to dispose of an owned reference creates a memory leak.

It is also possible to 'borrow' (1) a reference to an object.  The
borrower of a reference should not call *note Py_DECREF(): 791.  The
borrower must not hold on to the object longer than the owner from which
it was borrowed.  Using a borrowed reference after the owner has
disposed of it risks using freed memory and should be avoided completely
(2).

The advantage of borrowing over owning a reference is that you don’t
need to take care of disposing of the reference on all possible paths
through the code — in other words, with a borrowed reference you don’t
run the risk of leaking when a premature exit is taken.  The
disadvantage of borrowing over owning is that there are some subtle
situations where in seemingly correct code a borrowed reference can be
used after the owner from which it was borrowed has in fact disposed of
it.

A borrowed reference can be changed into an owned reference by calling
*note Py_INCREF(): 790.  This does not affect the status of the owner
from which the reference was borrowed — it creates a new owned
reference, and gives full owner responsibilities (the new owner must
dispose of the reference properly, as well as the previous owner).

   ---------- Footnotes ----------

   (1) The metaphor of «borrowing» a reference is not completely
correct: the owner still has a copy of the reference.

   (2) Checking that the reference count is at least 1 'does not work' —
the reference count itself could be in freed memory and may thus be
reused for another object!


File: python.info,  Node: Ownership Rules,  Next: Thin Ice,  Prev: Reference Counting in Python,  Up: Reference Counts

6.2.1.12 Ownership Rules
........................

Whenever an object reference is passed into or out of a function, it is
part of the function’s interface specification whether ownership is
transferred with the reference or not.

Most functions that return a reference to an object pass on ownership
with the reference.  In particular, all functions whose function it is
to create a new object, such as *note PyLong_FromLong(): 1bb8. and *note
Py_BuildValue(): 3c2, pass ownership to the receiver.  Even if the
object is not actually new, you still receive ownership of a new
reference to that object.  For instance, *note PyLong_FromLong(): 1bb8.
maintains a cache of popular values and can return a reference to a
cached item.

Many functions that extract objects from other objects also transfer
ownership with the reference, for instance *note
PyObject_GetAttrString(): 5ef.  The picture is less clear, here,
however, since a few common routines are exceptions: *note
PyTuple_GetItem(): 4ea0, *note PyList_GetItem(): 5ff, *note
PyDict_GetItem(): 628, and *note PyDict_GetItemString(): 629. all return
references that you borrow from the tuple, list or dictionary.

The function *note PyImport_AddModule(): 5fc. also returns a borrowed
reference, even though it may actually create the object it returns:
this is possible because an owned reference to the object is stored in
‘sys.modules’.

When you pass an object reference into another function, in general, the
function borrows the reference from you — if it needs to store it, it
will use *note Py_INCREF(): 790. to become an independent owner.  There
are exactly two important exceptions to this rule: *note
PyTuple_SetItem(): 4ea1. and *note PyList_SetItem(): 18a2.  These
functions take over ownership of the item passed to them — even if they
fail!  (Note that *note PyDict_SetItem(): 4ea2. and friends don’t take
over ownership — they are «normal.»)

When a C function is called from Python, it borrows references to its
arguments from the caller.  The caller owns a reference to the object,
so the borrowed reference’s lifetime is guaranteed until the function
returns.  Only when such a borrowed reference must be stored or passed
on, it must be turned into an owned reference by calling *note
Py_INCREF(): 790.

The object reference returned from a C function that is called from
Python must be an owned reference — ownership is transferred from the
function to its caller.


File: python.info,  Node: Thin Ice,  Next: NULL Pointers,  Prev: Ownership Rules,  Up: Reference Counts

6.2.1.13 Thin Ice
.................

There are a few situations where seemingly harmless use of a borrowed
reference can lead to problems.  These all have to do with implicit
invocations of the interpreter, which can cause the owner of a reference
to dispose of it.

The first and most important case to know about is using *note
Py_DECREF(): 791. on an unrelated object while borrowing a reference to
a list item.  For instance:

     void
     bug(PyObject *list)
     {
         PyObject *item = PyList_GetItem(list, 0);

         PyList_SetItem(list, 1, PyLong_FromLong(0L));
         PyObject_Print(item, stdout, 0); /* BUG! */
     }

This function first borrows a reference to ‘list[0]’, then replaces
‘list[1]’ with the value ‘0’, and finally prints the borrowed reference.
Looks harmless, right?  But it’s not!

Let’s follow the control flow into *note PyList_SetItem(): 18a2.  The
list owns references to all its items, so when item 1 is replaced, it
has to dispose of the original item 1.  Now let’s suppose the original
item 1 was an instance of a user-defined class, and let’s further
suppose that the class defined a ‘__del__()’ method.  If this class
instance has a reference count of 1, disposing of it will call its
‘__del__()’ method.  Internally, *note PyList_SetItem(): 18a2. calls
*note Py_DECREF(): 791. on the replaced item, which invokes replaced
item’s corresponding *note tp_dealloc: 4ea5. function.  During
deallocation, *note tp_dealloc: 4ea5. calls *note tp_finalize: c9f,
which is mapped to the ‘__del__()’ method for class instances (see PEP
442(1)).  This entire sequence happens synchronously within the *note
PyList_SetItem(): 18a2. call.

Since it is written in Python, the ‘__del__()’ method can execute
arbitrary Python code.  Could it perhaps do something to invalidate the
reference to ‘item’ in ‘bug()’?  You bet!  Assuming that the list passed
into ‘bug()’ is accessible to the ‘__del__()’ method, it could execute a
statement to the effect of ‘del list[0]’, and assuming this was the last
reference to that object, it would free the memory associated with it,
thereby invalidating ‘item’.

The solution, once you know the source of the problem, is easy:
temporarily increment the reference count.  The correct version of the
function reads:

     void
     no_bug(PyObject *list)
     {
         PyObject *item = PyList_GetItem(list, 0);

         Py_INCREF(item);
         PyList_SetItem(list, 1, PyLong_FromLong(0L));
         PyObject_Print(item, stdout, 0);
         Py_DECREF(item);
     }

This is a true story.  An older version of Python contained variants of
this bug and someone spent a considerable amount of time in a C debugger
to figure out why his ‘__del__()’ methods would fail…

The second case of problems with a borrowed reference is a variant
involving threads.  Normally, multiple threads in the Python interpreter
can’t get in each other’s way, because there is a *note global lock:
474. protecting Python’s entire object space.  However, it is possible
to temporarily release this lock using the macro *note
Py_BEGIN_ALLOW_THREADS: 4ea6, and to re-acquire it using *note
Py_END_ALLOW_THREADS: c81.  This is common around blocking I/O calls, to
let other threads use the processor while waiting for the I/O to
complete.  Obviously, the following function has the same problem as the
previous one:

     void
     bug(PyObject *list)
     {
         PyObject *item = PyList_GetItem(list, 0);
         Py_BEGIN_ALLOW_THREADS
         ...some blocking I/O call...
         Py_END_ALLOW_THREADS
         PyObject_Print(item, stdout, 0); /* BUG! */
     }

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0442/


File: python.info,  Node: NULL Pointers,  Prev: Thin Ice,  Up: Reference Counts

6.2.1.14 NULL Pointers
......................

In general, functions that take object references as arguments do not
expect you to pass them ‘NULL’ pointers, and will dump core (or cause
later core dumps) if you do so.  Functions that return object references
generally return ‘NULL’ only to indicate that an exception occurred.
The reason for not testing for ‘NULL’ arguments is that functions often
pass the objects they receive on to other function — if each function
were to test for ‘NULL’, there would be a lot of redundant tests and the
code would run more slowly.

It is better to test for ‘NULL’ only at the «source:» when a pointer
that may be ‘NULL’ is received, for example, from ‘malloc()’ or from a
function that may raise an exception.

The macros *note Py_INCREF(): 790. and *note Py_DECREF(): 791. do not
check for ‘NULL’ pointers — however, their variants *note Py_XINCREF():
c5c. and *note Py_XDECREF(): 993. do.

The macros for checking for a particular object type (‘Pytype_Check()’)
don’t check for ‘NULL’ pointers — again, there is much code that calls
several of these in a row to test an object against various different
expected types, and this would generate redundant tests.  There are no
variants with ‘NULL’ checking.

The C function calling mechanism guarantees that the argument list
passed to C functions (‘args’ in the examples) is never ‘NULL’ — in fact
it guarantees that it is always a tuple (1).

It is a severe error to ever let a ‘NULL’ pointer «escape» to the Python
user.

   ---------- Footnotes ----------

   (1) These guarantees don’t hold when you use the «old» style calling
convention — this is still found in much existing code.


File: python.info,  Node: Writing Extensions in C++,  Next: Providing a C API for an Extension Module,  Prev: Reference Counts,  Up: Extending Python with C or C++

6.2.1.15 Writing Extensions in C++
..................................

It is possible to write extension modules in C++.  Some restrictions
apply.  If the main program (the Python interpreter) is compiled and
linked by the C compiler, global or static objects with constructors
cannot be used.  This is not a problem if the main program is linked by
the C++ compiler.  Functions that will be called by the Python
interpreter (in particular, module initialization functions) have to be
declared using ‘extern "C"’.  It is unnecessary to enclose the Python
header files in ‘extern "C" {...}’ — they use this form already if the
symbol ‘__cplusplus’ is defined (all recent C++ compilers define this
symbol).


File: python.info,  Node: Providing a C API for an Extension Module,  Prev: Writing Extensions in C++,  Up: Extending Python with C or C++

6.2.1.16 Providing a C API for an Extension Module
..................................................

Many extension modules just provide new functions and types to be used
from Python, but sometimes the code in an extension module can be useful
for other extension modules.  For example, an extension module could
implement a type «collection» which works like lists without order.
Just like the standard Python list type has a C API which permits
extension modules to create and manipulate lists, this new collection
type should have a set of C functions for direct manipulation from other
extension modules.

At first sight this seems easy: just write the functions (without
declaring them ‘static’, of course), provide an appropriate header file,
and document the C API. And in fact this would work if all extension
modules were always linked statically with the Python interpreter.  When
modules are used as shared libraries, however, the symbols defined in
one module may not be visible to another module.  The details of
visibility depend on the operating system; some systems use one global
namespace for the Python interpreter and all extension modules (Windows,
for example), whereas others require an explicit list of imported
symbols at module link time (AIX is one example), or offer a choice of
different strategies (most Unices).  And even if symbols are globally
visible, the module whose functions one wishes to call might not have
been loaded yet!

Portability therefore requires not to make any assumptions about symbol
visibility.  This means that all symbols in extension modules should be
declared ‘static’, except for the module’s initialization function, in
order to avoid name clashes with other extension modules (as discussed
in section *note The Module’s Method Table and Initialization Function:
4e89.).  And it means that symbols that 'should' be accessible from
other extension modules must be exported in a different way.

Python provides a special mechanism to pass C-level information
(pointers) from one extension module to another one: Capsules.  A
Capsule is a Python data type which stores a pointer (void*).  Capsules
can only be created and accessed via their C API, but they can be passed
around like any other Python object.  In particular, they can be
assigned to a name in an extension module’s namespace.  Other extension
modules can then import this module, retrieve the value of this name,
and then retrieve the pointer from the Capsule.

There are many ways in which Capsules can be used to export the C API of
an extension module.  Each function could get its own Capsule, or all C
API pointers could be stored in an array whose address is published in a
Capsule.  And the various tasks of storing and retrieving the pointers
can be distributed in different ways between the module providing the
code and the client modules.

Whichever method you choose, it’s important to name your Capsules
properly.  The function *note PyCapsule_New(): 4eac. takes a name
parameter (const char*); you’re permitted to pass in a ‘NULL’ name, but
we strongly encourage you to specify a name.  Properly named Capsules
provide a degree of runtime type-safety; there is no feasible way to
tell one unnamed Capsule from another.

In particular, Capsules used to expose C APIs should be given a name
following this convention:

     modulename.attributename

The convenience function *note PyCapsule_Import(): 1bf8. makes it easy
to load a C API provided via a Capsule, but only if the Capsule’s name
matches this convention.  This behavior gives C API users a high degree
of certainty that the Capsule they load contains the correct C API.

The following example demonstrates an approach that puts most of the
burden on the writer of the exporting module, which is appropriate for
commonly used library modules.  It stores all C API pointers (just one
in the example!)  in an array of void pointers which becomes the value
of a Capsule.  The header file corresponding to the module provides a
macro that takes care of importing the module and retrieving its C API
pointers; client modules only have to call this macro before accessing
the C API.

The exporting module is a modification of the ‘spam’ module from section
*note A Simple Example: 4e7d.  The function ‘spam.system()’ does not
call the C library function ‘system()’ directly, but a function
‘PySpam_System()’, which would of course do something more complicated
in reality (such as adding «spam» to every command).  This function
‘PySpam_System()’ is also exported to other extension modules.

The function ‘PySpam_System()’ is a plain C function, declared ‘static’
like everything else:

     static int
     PySpam_System(const char *command)
     {
         return system(command);
     }

The function ‘spam_system()’ is modified in a trivial way:

     static PyObject *
     spam_system(PyObject *self, PyObject *args)
     {
         const char *command;
         int sts;

         if (!PyArg_ParseTuple(args, "s", &command))
             return NULL;
         sts = PySpam_System(command);
         return PyLong_FromLong(sts);
     }

In the beginning of the module, right after the line

     #include <Python.h>

two more lines must be added:

     #define SPAM_MODULE
     #include "spammodule.h"

The ‘#define’ is used to tell the header file that it is being included
in the exporting module, not a client module.  Finally, the module’s
*note mod_exec: b77. function must take care of initializing the C API
pointer array:

     static int
     spam_module_exec(PyObject *m)
     {
         static void *PySpam_API[PySpam_API_pointers];
         PyObject *c_api_object;

         /* Initialize the C API pointer array */
         PySpam_API[PySpam_System_NUM] = (void *)PySpam_System;

         /* Create a Capsule containing the API pointer array's address */
         c_api_object = PyCapsule_New((void *)PySpam_API, "spam._C_API", NULL);

         if (PyModule_Add(m, "_C_API", c_api_object) < 0) {
             return -1;
         }

         return 0;
     }

Note that ‘PySpam_API’ is declared ‘static’; otherwise the pointer array
would disappear when ‘PyInit_spam()’ terminates!

The bulk of the work is in the header file ‘spammodule.h’, which looks
like this:

     #ifndef Py_SPAMMODULE_H
     #define Py_SPAMMODULE_H
     #ifdef __cplusplus
     extern "C" {
     #endif

     /* Header file for spammodule */

     /* C API functions */
     #define PySpam_System_NUM 0
     #define PySpam_System_RETURN int
     #define PySpam_System_PROTO (const char *command)

     /* Total number of C API pointers */
     #define PySpam_API_pointers 1


     #ifdef SPAM_MODULE
     /* This section is used when compiling spammodule.c */

     static PySpam_System_RETURN PySpam_System PySpam_System_PROTO;

     #else
     /* This section is used in modules that use spammodule's API */

     static void **PySpam_API;

     #define PySpam_System \
      (*(PySpam_System_RETURN (*)PySpam_System_PROTO) PySpam_API[PySpam_System_NUM])

     /* Return -1 on error, 0 on success.
      * PyCapsule_Import will set an exception if there's an error.
      */
     static int
     import_spam(void)
     {
         PySpam_API = (void **)PyCapsule_Import("spam._C_API", 0);
         return (PySpam_API != NULL) ? 0 : -1;
     }

     #endif

     #ifdef __cplusplus
     }
     #endif

     #endif /* !defined(Py_SPAMMODULE_H) */

All that a client module must do in order to have access to the function
‘PySpam_System()’ is to call the function (or rather macro)
‘import_spam()’ in its *note mod_exec: b77. function:

     static int
     client_module_exec(PyObject *m)
     {
         if (import_spam() < 0) {
             return -1;
         }
         /* additional initialization can happen here */
         return 0;
     }

The main disadvantage of this approach is that the file ‘spammodule.h’
is rather complicated.  However, the basic structure is the same for
each function that is exported, so it has to be learned only once.

Finally it should be mentioned that Capsules offer additional
functionality, which is especially useful for memory allocation and
deallocation of the pointer stored in a Capsule.  The details are
described in the Python/C API Reference Manual in the section *note
Capsules: 29d7. and in the implementation of Capsules (files
‘Include/pycapsule.h’ and ‘Objects/pycapsule.c’ in the Python source
code distribution).


File: python.info,  Node: Defining Extension Types Tutorial,  Next: Defining Extension Types Assorted Topics,  Prev: Extending Python with C or C++,  Up: Creating extensions without third party tools

6.2.2 Defining Extension Types: Tutorial
----------------------------------------

Python allows the writer of a C extension module to define new types
that can be manipulated from Python code, much like the built-in *note
str: 169. and *note list: 24d. types.  The code for all extension types
follows a pattern, but there are some details that you need to
understand before you can get started.  This document is a gentle
introduction to the topic.

* Menu:

* The Basics::
* Adding data and methods to the Basic example::
* Providing finer control over data attributes::
* Supporting cyclic garbage collection::
* Subclassing other types::


File: python.info,  Node: The Basics,  Next: Adding data and methods to the Basic example,  Up: Defining Extension Types Tutorial

6.2.2.1 The Basics
..................

The *note CPython: 906. runtime sees all Python objects as variables of
type *note PyObject: 5df.*, which serves as a «base type» for all Python
objects.  The *note PyObject: 5df. structure itself only contains the
object’s *note reference count: 4eb2. and a pointer to the object’s
«type object».  This is where the action is; the type object determines
which (C) functions get called by the interpreter when, for instance, an
attribute gets looked up on an object, a method called, or it is
multiplied by another object.  These C functions are called «type
methods».

So, if you want to define a new extension type, you need to create a new
type object.

This sort of thing can only be explained by example, so here’s a
minimal, but complete, module that defines a new type named ‘Custom’
inside a C extension module ‘custom’:

     Nota: What we’re showing here is the traditional way of defining
     'static' extension types.  It should be adequate for most uses.
     The C API also allows defining heap-allocated extension types using
     the *note PyType_FromSpec(): 79e. function, which isn’t covered in
     this tutorial.

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>

     typedef struct {
         PyObject_HEAD
         /* Type-specific fields go here. */
     } CustomObject;

     static PyTypeObject CustomType = {
         .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
         .tp_name = "custom.Custom",
         .tp_doc = PyDoc_STR("Custom objects"),
         .tp_basicsize = sizeof(CustomObject),
         .tp_itemsize = 0,
         .tp_flags = Py_TPFLAGS_DEFAULT,
         .tp_new = PyType_GenericNew,
     };

     static int
     custom_module_exec(PyObject *m)
     {
         if (PyType_Ready(&CustomType) < 0) {
             return -1;
         }

         if (PyModule_AddObjectRef(m, "Custom", (PyObject *) &CustomType) < 0) {
             return -1;
         }

         return 0;
     }

     static PyModuleDef_Slot custom_module_slots[] = {
         {Py_mod_exec, custom_module_exec},
         // Just use this while using static types
         {Py_mod_multiple_interpreters, Py_MOD_MULTIPLE_INTERPRETERS_NOT_SUPPORTED},
         {0, NULL}
     };

     static PyModuleDef custom_module = {
         .m_base = PyModuleDef_HEAD_INIT,
         .m_name = "custom",
         .m_doc = "Example module that creates an extension type.",
         .m_size = 0,
         .m_slots = custom_module_slots,
     };

     PyMODINIT_FUNC
     PyInit_custom(void)
     {
         return PyModuleDef_Init(&custom_module);
     }

Now that’s quite a bit to take in at once, but hopefully bits will seem
familiar from the previous chapter.  This file defines three things:

  1. What a ‘Custom’ 'object' contains: this is the ‘CustomObject’
     struct, which is allocated once for each ‘Custom’ instance.

  2. How the ‘Custom’ 'type' behaves: this is the ‘CustomType’ struct,
     which defines a set of flags and function pointers that the
     interpreter inspects when specific operations are requested.

  3. How to define and execute the ‘custom’ module: this is the
     ‘PyInit_custom’ function and the associated ‘custom_module’ struct
     for defining the module, and the ‘custom_module_exec’ function to
     set up a fresh module object.

The first bit is:

     typedef struct {
         PyObject_HEAD
     } CustomObject;

This is what a Custom object will contain.  ‘PyObject_HEAD’ is mandatory
at the start of each object struct and defines a field called ‘ob_base’
of type *note PyObject: 5df, containing a pointer to a type object and a
reference count (these can be accessed using the macros *note Py_TYPE:
3c9. and *note Py_REFCNT: 2cf. respectively).  The reason for the macro
is to abstract away the layout and to enable additional fields in *note
debug builds: 50a.

     Nota: There is no semicolon above after the *note PyObject_HEAD:
     14e5. macro.  Be wary of adding one by accident: some compilers
     will complain.

Of course, objects generally store additional data besides the standard
‘PyObject_HEAD’ boilerplate; for example, here is the definition for
standard Python floats:

     typedef struct {
         PyObject_HEAD
         double ob_fval;
     } PyFloatObject;

The second bit is the definition of the type object.

     static PyTypeObject CustomType = {
         .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
         .tp_name = "custom.Custom",
         .tp_doc = PyDoc_STR("Custom objects"),
         .tp_basicsize = sizeof(CustomObject),
         .tp_itemsize = 0,
         .tp_flags = Py_TPFLAGS_DEFAULT,
         .tp_new = PyType_GenericNew,
     };

     Nota: We recommend using C99-style designated initializers as
     above, to avoid listing all the *note PyTypeObject: c9e. fields
     that you don’t care about and also to avoid caring about the
     fields” declaration order.

The actual definition of *note PyTypeObject: c9e. in ‘object.h’ has many
more *note fields: b86. than the definition above.  The remaining fields
will be filled with zeros by the C compiler, and it’s common practice to
not specify them explicitly unless you need them.

We’re going to pick it apart, one field at a time:

     .ob_base = PyVarObject_HEAD_INIT(NULL, 0)

This line is mandatory boilerplate to initialize the ‘ob_base’ field
mentioned above.

     .tp_name = "custom.Custom",

The name of our type.  This will appear in the default textual
representation of our objects and in some error messages, for example:

     >>> "" + custom.Custom()
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: can only concatenate str (not "custom.Custom") to str

Note that the name is a dotted name that includes both the module name
and the name of the type within the module.  The module in this case is
‘custom’ and the type is ‘Custom’, so we set the type name to
‘custom.Custom’.  Using the real dotted import path is important to make
your type compatible with the *note pydoc: ba. and *note pickle: ab.
modules.

     .tp_basicsize = sizeof(CustomObject),
     .tp_itemsize = 0,

This is so that Python knows how much memory to allocate when creating
new ‘Custom’ instances.  *note tp_itemsize: 23a1. is only used for
variable-sized objects and should otherwise be zero.

     Nota: If you want your type to be subclassable from Python, and
     your type has the same *note tp_basicsize: b80. as its base type,
     you may have problems with multiple inheritance.  A Python subclass
     of your type will have to list your type first in its *note
     __bases__: 16b3, or else it will not be able to call your type’s
     *note __new__(): 7a1. method without getting an error.  You can
     avoid this problem by ensuring that your type has a larger value
     for *note tp_basicsize: b80. than its base type does.  Most of the
     time, this will be true anyway, because either your base type will
     be *note object: c80, or else you will be adding data members to
     your base type, and therefore increasing its size.

We set the class flags to *note Py_TPFLAGS_DEFAULT: 4eb3.

     .tp_flags = Py_TPFLAGS_DEFAULT,

All types should include this constant in their flags.  It enables all
of the members defined until at least Python 3.3.  If you need further
members, you will need to OR the corresponding flags.

We provide a doc string for the type in *note tp_doc: 4eb4.

     .tp_doc = PyDoc_STR("Custom objects"),

To enable object creation, we have to provide a *note tp_new: 7a0.
handler.  This is the equivalent of the Python method *note __new__():
7a1, but has to be specified explicitly.  In this case, we can just use
the default implementation provided by the API function *note
PyType_GenericNew(): 4eb5.

     .tp_new = PyType_GenericNew,

Everything else in the file should be familiar, except for some code in
‘custom_module_exec()’:

     if (PyType_Ready(&CustomType) < 0) {
         return -1;
     }

This initializes the ‘Custom’ type, filling in a number of members to
the appropriate default values, including *note ob_type: 4eb6. that we
initially set to ‘NULL’.

     if (PyModule_AddObjectRef(m, "Custom", (PyObject *) &CustomType) < 0) {
         return -1;
     }

This adds the type to the module dictionary.  This allows us to create
‘Custom’ instances by calling the ‘Custom’ class:

     >>> import custom
     >>> mycustom = custom.Custom()

That’s it!  All that remains is to build it; put the above code in a
file called ‘custom.c’,

     [build-system]
     requires = ["setuptools"]
     build-backend = "setuptools.build_meta"

     [project]
     name = "custom"
     version = "1"

in a file called ‘pyproject.toml’, and

     from setuptools import Extension, setup
     setup(ext_modules=[Extension("custom", ["custom.c"])])

in a file called ‘setup.py’; then typing

     $ python -m pip install .

in a shell should produce a file ‘custom.so’ in a subdirectory and
install it; now fire up Python — you should be able to ‘import custom’
and play around with ‘Custom’ objects.

That wasn’t so hard, was it?

Of course, the current Custom type is pretty uninteresting.  It has no
data and doesn’t do anything.  It can’t even be subclassed.


File: python.info,  Node: Adding data and methods to the Basic example,  Next: Providing finer control over data attributes,  Prev: The Basics,  Up: Defining Extension Types Tutorial

6.2.2.2 Adding data and methods to the Basic example
....................................................

Let’s extend the basic example to add some data and methods.  Let’s also
make the type usable as a base class.  We’ll create a new module,
‘custom2’ that adds these capabilities:

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>
     #include <stddef.h> /* for offsetof() */

     typedef struct {
         PyObject_HEAD
         PyObject *first; /* first name */
         PyObject *last;  /* last name */
         int number;
     } CustomObject;

     static void
     Custom_dealloc(PyObject *op)
     {
         CustomObject *self = (CustomObject *) op;
         Py_XDECREF(self->first);
         Py_XDECREF(self->last);
         Py_TYPE(self)->tp_free(self);
     }

     static PyObject *
     Custom_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     {
         CustomObject *self;
         self = (CustomObject *) type->tp_alloc(type, 0);
         if (self != NULL) {
             self->first = Py_GetConstant(Py_CONSTANT_EMPTY_STR);
             if (self->first == NULL) {
                 Py_DECREF(self);
                 return NULL;
             }
             self->last = Py_GetConstant(Py_CONSTANT_EMPTY_STR);
             if (self->last == NULL) {
                 Py_DECREF(self);
                 return NULL;
             }
             self->number = 0;
         }
         return (PyObject *) self;
     }

     static int
     Custom_init(PyObject *op, PyObject *args, PyObject *kwds)
     {
         CustomObject *self = (CustomObject *) op;
         static char *kwlist[] = {"first", "last", "number", NULL};
         PyObject *first = NULL, *last = NULL;

         if (!PyArg_ParseTupleAndKeywords(args, kwds, "|OOi", kwlist,
                                          &first, &last,
                                          &self->number))
             return -1;

         if (first) {
             Py_XSETREF(self->first, Py_NewRef(first));
         }
         if (last) {
             Py_XSETREF(self->last, Py_NewRef(last));
         }
         return 0;
     }

     static PyMemberDef Custom_members[] = {
         {"first", Py_T_OBJECT_EX, offsetof(CustomObject, first), 0,
          "first name"},
         {"last", Py_T_OBJECT_EX, offsetof(CustomObject, last), 0,
          "last name"},
         {"number", Py_T_INT, offsetof(CustomObject, number), 0,
          "custom number"},
         {NULL}  /* Sentinel */
     };

     static PyObject *
     Custom_name(PyObject *op, PyObject *Py_UNUSED(dummy))
     {
         CustomObject *self = (CustomObject *) op;
         if (self->first == NULL) {
             PyErr_SetString(PyExc_AttributeError, "first");
             return NULL;
         }
         if (self->last == NULL) {
             PyErr_SetString(PyExc_AttributeError, "last");
             return NULL;
         }
         return PyUnicode_FromFormat("%S %S", self->first, self->last);
     }

     static PyMethodDef Custom_methods[] = {
         {"name", Custom_name, METH_NOARGS,
          "Return the name, combining the first and last name"
         },
         {NULL}  /* Sentinel */
     };

     static PyTypeObject CustomType = {
         .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
         .tp_name = "custom2.Custom",
         .tp_doc = PyDoc_STR("Custom objects"),
         .tp_basicsize = sizeof(CustomObject),
         .tp_itemsize = 0,
         .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
         .tp_new = Custom_new,
         .tp_init = Custom_init,
         .tp_dealloc = Custom_dealloc,
         .tp_members = Custom_members,
         .tp_methods = Custom_methods,
     };

     static int
     custom_module_exec(PyObject *m)
     {
         if (PyType_Ready(&CustomType) < 0) {
             return -1;
         }

         if (PyModule_AddObjectRef(m, "Custom", (PyObject *) &CustomType) < 0) {
             return -1;
         }

         return 0;
     }

     static PyModuleDef_Slot custom_module_slots[] = {
         {Py_mod_exec, custom_module_exec},
         {Py_mod_multiple_interpreters, Py_MOD_MULTIPLE_INTERPRETERS_NOT_SUPPORTED},
         {0, NULL}
     };

     static PyModuleDef custom_module = {
         .m_base = PyModuleDef_HEAD_INIT,
         .m_name = "custom2",
         .m_doc = "Example module that creates an extension type.",
         .m_size = 0,
         .m_slots = custom_module_slots,
     };

     PyMODINIT_FUNC
     PyInit_custom2(void)
     {
         return PyModuleDef_Init(&custom_module);
     }

This version of the module has a number of changes.

The ‘Custom’ type now has three data attributes in its C struct,
'first', 'last', and 'number'.  The 'first' and 'last' variables are
Python strings containing first and last names.  The 'number' attribute
is a C integer.

The object structure is updated accordingly:

     typedef struct {
         PyObject_HEAD
         PyObject *first; /* first name */
         PyObject *last;  /* last name */
         int number;
     } CustomObject;

Because we now have data to manage, we have to be more careful about
object allocation and deallocation.  At a minimum, we need a
deallocation method:

     static void
     Custom_dealloc(PyObject *op)
     {
         CustomObject *self = (CustomObject *) op;
         Py_XDECREF(self->first);
         Py_XDECREF(self->last);
         Py_TYPE(self)->tp_free(self);
     }

which is assigned to the *note tp_dealloc: 4ea5. member:

     .tp_dealloc = Custom_dealloc,

This method first clears the reference counts of the two Python
attributes.  *note Py_XDECREF(): 993. correctly handles the case where
its argument is ‘NULL’ (which might happen here if ‘tp_new’ failed
midway).  It then calls the *note tp_free: 4eb8. member of the object’s
type (computed by ‘Py_TYPE(self)’) to free the object’s memory.  Note
that the object’s type might not be ‘CustomType’, because the object may
be an instance of a subclass.

     Nota: The explicit cast to ‘CustomObject *’ above is needed because
     we defined ‘Custom_dealloc’ to take a ‘PyObject *’ argument, as the
     ‘tp_dealloc’ function pointer expects to receive a ‘PyObject *’
     argument.  By assigning to the ‘tp_dealloc’ slot of a type, we
     declare that it can only be called with instances of our
     ‘CustomObject’ class, so the cast to ‘(CustomObject *)’ is safe.
     This is object-oriented polymorphism, in C!

     In existing code, or in previous versions of this tutorial, you
     might see similar functions take a pointer to the subtype object
     structure (‘CustomObject*’) directly, like this:

          Custom_dealloc(CustomObject *self)
          {
              Py_XDECREF(self->first);
              Py_XDECREF(self->last);
              Py_TYPE(self)->tp_free((PyObject *) self);
          }
          ...
          .tp_dealloc = (destructor) Custom_dealloc,

     This does the same thing on all architectures that CPython
     supports, but according to the C standard, it invokes undefined
     behavior.

We want to make sure that the first and last names are initialized to
empty strings, so we provide a ‘tp_new’ implementation:

     static PyObject *
     Custom_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     {
         CustomObject *self;
         self = (CustomObject *) type->tp_alloc(type, 0);
         if (self != NULL) {
             self->first = PyUnicode_FromString("");
             if (self->first == NULL) {
                 Py_DECREF(self);
                 return NULL;
             }
             self->last = PyUnicode_FromString("");
             if (self->last == NULL) {
                 Py_DECREF(self);
                 return NULL;
             }
             self->number = 0;
         }
         return (PyObject *) self;
     }

and install it in the *note tp_new: 7a0. member:

     .tp_new = Custom_new,

The ‘tp_new’ handler is responsible for creating (as opposed to
initializing) objects of the type.  It is exposed in Python as the *note
__new__(): 7a1. method.  It is not required to define a ‘tp_new’ member,
and indeed many extension types will simply reuse *note
PyType_GenericNew(): 4eb5. as done in the first version of the ‘Custom’
type above.  In this case, we use the ‘tp_new’ handler to initialize the
‘first’ and ‘last’ attributes to non-‘NULL’ default values.

‘tp_new’ is passed the type being instantiated (not necessarily
‘CustomType’, if a subclass is instantiated) and any arguments passed
when the type was called, and is expected to return the instance
created.  ‘tp_new’ handlers always accept positional and keyword
arguments, but they often ignore the arguments, leaving the argument
handling to initializer (a.k.a.  ‘tp_init’ in C or ‘__init__’ in Python)
methods.

     Nota: ‘tp_new’ shouldn’t call ‘tp_init’ explicitly, as the
     interpreter will do it itself.

The ‘tp_new’ implementation calls the *note tp_alloc: 4eb9. slot to
allocate memory:

     self = (CustomObject *) type->tp_alloc(type, 0);

Since memory allocation may fail, we must check the *note tp_alloc:
4eb9. result against ‘NULL’ before proceeding.

     Nota: We didn’t fill the *note tp_alloc: 4eb9. slot ourselves.
     Rather *note PyType_Ready(): 981. fills it for us by inheriting it
     from our base class, which is *note object: c80. by default.  Most
     types use the default allocation strategy.

     Nota: If you are creating a co-operative *note tp_new: 7a0. (one
     that calls a base type’s *note tp_new: 7a0. or *note __new__():
     7a1.), you must 'not' try to determine what method to call using
     method resolution order at runtime.  Always statically determine
     what type you are going to call, and call its *note tp_new: 7a0.
     directly, or via ‘type->tp_base->tp_new’.  If you do not do this,
     Python subclasses of your type that also inherit from other
     Python-defined classes may not work correctly.  (Specifically, you
     may not be able to create instances of such subclasses without
     getting a *note TypeError: 198.)

We also define an initialization function which accepts arguments to
provide initial values for our instance:

     static int
     Custom_init(PyObject *op, PyObject *args, PyObject *kwds)
     {
         CustomObject *self = (CustomObject *) op;
         static char *kwlist[] = {"first", "last", "number", NULL};
         PyObject *first = NULL, *last = NULL, *tmp;

         if (!PyArg_ParseTupleAndKeywords(args, kwds, "|OOi", kwlist,
                                          &first, &last,
                                          &self->number))
             return -1;

         if (first) {
             tmp = self->first;
             Py_INCREF(first);
             self->first = first;
             Py_XDECREF(tmp);
         }
         if (last) {
             tmp = self->last;
             Py_INCREF(last);
             self->last = last;
             Py_XDECREF(tmp);
         }
         return 0;
     }

by filling the *note tp_init: 7a2. slot.

     .tp_init = Custom_init,

The *note tp_init: 7a2. slot is exposed in Python as the *note
__init__(): 8c0. method.  It is used to initialize an object after it’s
created.  Initializers always accept positional and keyword arguments,
and they should return either ‘0’ on success or ‘-1’ on error.

Unlike the ‘tp_new’ handler, there is no guarantee that ‘tp_init’ is
called at all (for example, the *note pickle: ab. module by default
doesn’t call *note __init__(): 8c0. on unpickled instances).  It can
also be called multiple times.  Anyone can call the ‘__init__()’ method
on our objects.  For this reason, we have to be extra careful when
assigning the new attribute values.  We might be tempted, for example to
assign the ‘first’ member like this:

     if (first) {
         Py_XDECREF(self->first);
         Py_INCREF(first);
         self->first = first;
     }

But this would be risky.  Our type doesn’t restrict the type of the
‘first’ member, so it could be any kind of object.  It could have a
destructor that causes code to be executed that tries to access the
‘first’ member; or that destructor could detach the *note thread state:
4eba. and let arbitrary code run in other threads that accesses and
modifies our object.

To be paranoid and protect ourselves against this possibility, we almost
always reassign members before decrementing their reference counts.
When don’t we have to do this?

   * when we absolutely know that the reference count is greater than 1;

   * when we know that deallocation of the object (1) will neither
     detach the *note thread state: 4eba. nor cause any calls back into
     our type’s code;

   * when decrementing a reference count in a *note tp_dealloc: 4ea5.
     handler on a type which doesn’t support cyclic garbage collection
     (2).

We want to expose our instance variables as attributes.  There are a
number of ways to do that.  The simplest way is to define member
definitions:

     static PyMemberDef Custom_members[] = {
         {"first", Py_T_OBJECT_EX, offsetof(CustomObject, first), 0,
          "first name"},
         {"last", Py_T_OBJECT_EX, offsetof(CustomObject, last), 0,
          "last name"},
         {"number", Py_T_INT, offsetof(CustomObject, number), 0,
          "custom number"},
         {NULL}  /* Sentinel */
     };

and put the definitions in the *note tp_members: 4ebb. slot:

     .tp_members = Custom_members,

Each member definition has a member name, type, offset, access flags and
documentation string.  See the *note Generic Attribute Management: 4ebc.
section below for details.

A disadvantage of this approach is that it doesn’t provide a way to
restrict the types of objects that can be assigned to the Python
attributes.  We expect the first and last names to be strings, but any
Python objects can be assigned.  Further, the attributes can be deleted,
setting the C pointers to ‘NULL’.  Even though we can make sure the
members are initialized to non-‘NULL’ values, the members can be set to
‘NULL’ if the attributes are deleted.

We define a single method, ‘Custom.name()’, that outputs the objects
name as the concatenation of the first and last names.

     static PyObject *
     Custom_name(PyObject *op, PyObject *Py_UNUSED(dummy))
     {
         CustomObject *self = (CustomObject *) op;
         if (self->first == NULL) {
             PyErr_SetString(PyExc_AttributeError, "first");
             return NULL;
         }
         if (self->last == NULL) {
             PyErr_SetString(PyExc_AttributeError, "last");
             return NULL;
         }
         return PyUnicode_FromFormat("%S %S", self->first, self->last);
     }

The method is implemented as a C function that takes a ‘Custom’ (or
‘Custom’ subclass) instance as the first argument.  Methods always take
an instance as the first argument.  Methods often take positional and
keyword arguments as well, but in this case we don’t take any and don’t
need to accept a positional argument tuple or keyword argument
dictionary.  This method is equivalent to the Python method:

     def name(self):
         return "%s %s" % (self.first, self.last)

Note that we have to check for the possibility that our ‘first’ and
‘last’ members are ‘NULL’.  This is because they can be deleted, in
which case they are set to ‘NULL’.  It would be better to prevent
deletion of these attributes and to restrict the attribute values to be
strings.  We’ll see how to do that in the next section.

Now that we’ve defined the method, we need to create an array of method
definitions:

     static PyMethodDef Custom_methods[] = {
         {"name", Custom_name, METH_NOARGS,
          "Return the name, combining the first and last name"
         },
         {NULL}  /* Sentinel */
     };

(note that we used the *note METH_NOARGS: 16db. flag to indicate that
the method is expecting no arguments other than 'self')

and assign it to the *note tp_methods: 4ebd. slot:

     .tp_methods = Custom_methods,

Finally, we’ll make our type usable as a base class for subclassing.
We’ve written our methods carefully so far so that they don’t make any
assumptions about the type of the object being created or used, so all
we need to do is to add the *note Py_TPFLAGS_BASETYPE: 4ebe. to our
class flag definition:

     .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,

We rename ‘PyInit_custom()’ to ‘PyInit_custom2()’, update the module
name in the *note PyModuleDef: b76. struct, and update the full class
name in the *note PyTypeObject: c9e. struct.

Finally, we update our ‘setup.py’ file to include the new module,

     from setuptools import Extension, setup
     setup(ext_modules=[
         Extension("custom", ["custom.c"]),
         Extension("custom2", ["custom2.c"]),
     ])

and then we re-install so that we can ‘import custom2’:

     $ python -m pip install .

   ---------- Footnotes ----------

   (1) This is true when we know that the object is a basic type, like a
string or a float.

   (2) We relied on this in the *note tp_dealloc: 4ea5. handler in this
example, because our type doesn’t support garbage collection.


File: python.info,  Node: Providing finer control over data attributes,  Next: Supporting cyclic garbage collection,  Prev: Adding data and methods to the Basic example,  Up: Defining Extension Types Tutorial

6.2.2.3 Providing finer control over data attributes
....................................................

In this section, we’ll provide finer control over how the ‘first’ and
‘last’ attributes are set in the ‘Custom’ example.  In the previous
version of our module, the instance variables ‘first’ and ‘last’ could
be set to non-string values or even deleted.  We want to make sure that
these attributes always contain strings.

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>
     #include <stddef.h> /* for offsetof() */

     typedef struct {
         PyObject_HEAD
         PyObject *first; /* first name */
         PyObject *last;  /* last name */
         int number;
     } CustomObject;

     static void
     Custom_dealloc(PyObject *op)
     {
         CustomObject *self = (CustomObject *) op;
         Py_XDECREF(self->first);
         Py_XDECREF(self->last);
         Py_TYPE(self)->tp_free(self);
     }

     static PyObject *
     Custom_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     {
         CustomObject *self;
         self = (CustomObject *) type->tp_alloc(type, 0);
         if (self != NULL) {
             self->first = Py_GetConstant(Py_CONSTANT_EMPTY_STR);
             if (self->first == NULL) {
                 Py_DECREF(self);
                 return NULL;
             }
             self->last = Py_GetConstant(Py_CONSTANT_EMPTY_STR);
             if (self->last == NULL) {
                 Py_DECREF(self);
                 return NULL;
             }
             self->number = 0;
         }
         return (PyObject *) self;
     }

     static int
     Custom_init(PyObject *op, PyObject *args, PyObject *kwds)
     {
         CustomObject *self = (CustomObject *) op;
         static char *kwlist[] = {"first", "last", "number", NULL};
         PyObject *first = NULL, *last = NULL;

         if (!PyArg_ParseTupleAndKeywords(args, kwds, "|UUi", kwlist,
                                          &first, &last,
                                          &self->number))
             return -1;

         if (first) {
             Py_SETREF(self->first, Py_NewRef(first));
         }
         if (last) {
             Py_SETREF(self->last, Py_NewRef(last));
         }
         return 0;
     }

     static PyMemberDef Custom_members[] = {
         {"number", Py_T_INT, offsetof(CustomObject, number), 0,
          "custom number"},
         {NULL}  /* Sentinel */
     };

     static PyObject *
     Custom_getfirst(PyObject *op, void *closure)
     {
         CustomObject *self = (CustomObject *) op;
         return Py_NewRef(self->first);
     }

     static int
     Custom_setfirst(PyObject *op, PyObject *value, void *closure)
     {
         CustomObject *self = (CustomObject *) op;
         if (value == NULL) {
             PyErr_SetString(PyExc_TypeError, "Cannot delete the first attribute");
             return -1;
         }
         if (!PyUnicode_Check(value)) {
             PyErr_SetString(PyExc_TypeError,
                             "The first attribute value must be a string");
             return -1;
         }
         Py_SETREF(self->first, Py_NewRef(value));
         return 0;
     }

     static PyObject *
     Custom_getlast(PyObject *op, void *closure)
     {
         CustomObject *self = (CustomObject *) op;
         return Py_NewRef(self->last);
     }

     static int
     Custom_setlast(PyObject *op, PyObject *value, void *closure)
     {
         CustomObject *self = (CustomObject *) op;
         if (value == NULL) {
             PyErr_SetString(PyExc_TypeError, "Cannot delete the last attribute");
             return -1;
         }
         if (!PyUnicode_Check(value)) {
             PyErr_SetString(PyExc_TypeError,
                             "The last attribute value must be a string");
             return -1;
         }
         Py_SETREF(self->last, Py_NewRef(value));
         return 0;
     }

     static PyGetSetDef Custom_getsetters[] = {
         {"first", Custom_getfirst, Custom_setfirst,
          "first name", NULL},
         {"last", Custom_getlast, Custom_setlast,
          "last name", NULL},
         {NULL}  /* Sentinel */
     };

     static PyObject *
     Custom_name(PyObject *op, PyObject *Py_UNUSED(dummy))
     {
         CustomObject *self = (CustomObject *) op;
         return PyUnicode_FromFormat("%S %S", self->first, self->last);
     }

     static PyMethodDef Custom_methods[] = {
         {"name", Custom_name, METH_NOARGS,
          "Return the name, combining the first and last name"
         },
         {NULL}  /* Sentinel */
     };

     static PyTypeObject CustomType = {
         .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
         .tp_name = "custom3.Custom",
         .tp_doc = PyDoc_STR("Custom objects"),
         .tp_basicsize = sizeof(CustomObject),
         .tp_itemsize = 0,
         .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
         .tp_new = Custom_new,
         .tp_init = Custom_init,
         .tp_dealloc = Custom_dealloc,
         .tp_members = Custom_members,
         .tp_methods = Custom_methods,
         .tp_getset = Custom_getsetters,
     };

     static int
     custom_module_exec(PyObject *m)
     {
         if (PyType_Ready(&CustomType) < 0) {
             return -1;
         }

         if (PyModule_AddObjectRef(m, "Custom", (PyObject *) &CustomType) < 0) {
             return -1;
         }

         return 0;
     }

     static PyModuleDef_Slot custom_module_slots[] = {
         {Py_mod_exec, custom_module_exec},
         {Py_mod_multiple_interpreters, Py_MOD_MULTIPLE_INTERPRETERS_NOT_SUPPORTED},
         {0, NULL}
     };

     static PyModuleDef custom_module = {
         .m_base = PyModuleDef_HEAD_INIT,
         .m_name = "custom3",
         .m_doc = "Example module that creates an extension type.",
         .m_size = 0,
         .m_slots = custom_module_slots,
     };

     PyMODINIT_FUNC
     PyInit_custom3(void)
     {
         return PyModuleDef_Init(&custom_module);
     }

To provide greater control, over the ‘first’ and ‘last’ attributes,
we’ll use custom getter and setter functions.  Here are the functions
for getting and setting the ‘first’ attribute:

     static PyObject *
     Custom_getfirst(PyObject *op, void *closure)
     {
         CustomObject *self = (CustomObject *) op;
         Py_INCREF(self->first);
         return self->first;
     }

     static int
     Custom_setfirst(PyObject *op, PyObject *value, void *closure)
     {
         CustomObject *self = (CustomObject *) op;
         PyObject *tmp;
         if (value == NULL) {
             PyErr_SetString(PyExc_TypeError, "Cannot delete the first attribute");
             return -1;
         }
         if (!PyUnicode_Check(value)) {
             PyErr_SetString(PyExc_TypeError,
                             "The first attribute value must be a string");
             return -1;
         }
         tmp = self->first;
         Py_INCREF(value);
         self->first = value;
         Py_DECREF(tmp);
         return 0;
     }

The getter function is passed a ‘Custom’ object and a «closure», which
is a void pointer.  In this case, the closure is ignored.  (The closure
supports an advanced usage in which definition data is passed to the
getter and setter.  This could, for example, be used to allow a single
set of getter and setter functions that decide the attribute to get or
set based on data in the closure.)

The setter function is passed the ‘Custom’ object, the new value, and
the closure.  The new value may be ‘NULL’, in which case the attribute
is being deleted.  In our setter, we raise an error if the attribute is
deleted or if its new value is not a string.

We create an array of *note PyGetSetDef: db4. structures:

     static PyGetSetDef Custom_getsetters[] = {
         {"first", Custom_getfirst, Custom_setfirst,
          "first name", NULL},
         {"last", Custom_getlast, Custom_setlast,
          "last name", NULL},
         {NULL}  /* Sentinel */
     };

and register it in the *note tp_getset: 4ec0. slot:

     .tp_getset = Custom_getsetters,

The last item in a *note PyGetSetDef: db4. structure is the «closure»
mentioned above.  In this case, we aren’t using a closure, so we just
pass ‘NULL’.

We also remove the member definitions for these attributes:

     static PyMemberDef Custom_members[] = {
         {"number", Py_T_INT, offsetof(CustomObject, number), 0,
          "custom number"},
         {NULL}  /* Sentinel */
     };

We also need to update the *note tp_init: 7a2. handler to only allow
strings (1) to be passed:

     static int
     Custom_init(PyObject *op, PyObject *args, PyObject *kwds)
     {
         CustomObject *self = (CustomObject *) op;
         static char *kwlist[] = {"first", "last", "number", NULL};
         PyObject *first = NULL, *last = NULL, *tmp;

         if (!PyArg_ParseTupleAndKeywords(args, kwds, "|UUi", kwlist,
                                          &first, &last,
                                          &self->number))
             return -1;

         if (first) {
             tmp = self->first;
             Py_INCREF(first);
             self->first = first;
             Py_DECREF(tmp);
         }
         if (last) {
             tmp = self->last;
             Py_INCREF(last);
             self->last = last;
             Py_DECREF(tmp);
         }
         return 0;
     }

With these changes, we can assure that the ‘first’ and ‘last’ members
are never ‘NULL’ so we can remove checks for ‘NULL’ values in almost all
cases.  This means that most of the *note Py_XDECREF(): 993. calls can
be converted to *note Py_DECREF(): 791. calls.  The only place we can’t
change these calls is in the ‘tp_dealloc’ implementation, where there is
the possibility that the initialization of these members failed in
‘tp_new’.

We also rename the module initialization function and module name in the
initialization function, as we did before, and we add an extra
definition to the ‘setup.py’ file.

   ---------- Footnotes ----------

   (1) We now know that the first and last members are strings, so
perhaps we could be less careful about decrementing their reference
counts, however, we accept instances of string subclasses.  Even though
deallocating normal strings won’t call back into our objects, we can’t
guarantee that deallocating an instance of a string subclass won’t call
back into our objects.


File: python.info,  Node: Supporting cyclic garbage collection,  Next: Subclassing other types,  Prev: Providing finer control over data attributes,  Up: Defining Extension Types Tutorial

6.2.2.4 Supporting cyclic garbage collection
............................................

Python has a *note cyclic garbage collector (GC): 17c0. that can
identify unneeded objects even when their reference counts are not zero.
This can happen when objects are involved in cycles.  For example,
consider:

     >>> l = []
     >>> l.append(l)
     >>> del l

In this example, we create a list that contains itself.  When we delete
it, it still has a reference from itself.  Its reference count doesn’t
drop to zero.  Fortunately, Python’s cyclic garbage collector will
eventually figure out that the list is garbage and free it.

In the second version of the ‘Custom’ example, we allowed any kind of
object to be stored in the ‘first’ or ‘last’ attributes (1).  Besides,
in the second and third versions, we allowed subclassing ‘Custom’, and
subclasses may add arbitrary attributes.  For any of those two reasons,
‘Custom’ objects can participate in cycles:

     >>> import custom3
     >>> class Derived(custom3.Custom): pass
     ...
     >>> n = Derived()
     >>> n.some_attribute = n

To allow a ‘Custom’ instance participating in a reference cycle to be
properly detected and collected by the cyclic GC, our ‘Custom’ type
needs to fill two additional slots and to enable a flag that enables
these slots:

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>
     #include <stddef.h> /* for offsetof() */

     typedef struct {
         PyObject_HEAD
         PyObject *first; /* first name */
         PyObject *last;  /* last name */
         int number;
     } CustomObject;

     static int
     Custom_traverse(PyObject *op, visitproc visit, void *arg)
     {
         CustomObject *self = (CustomObject *) op;
         Py_VISIT(self->first);
         Py_VISIT(self->last);
         return 0;
     }

     static int
     Custom_clear(PyObject *op)
     {
         CustomObject *self = (CustomObject *) op;
         Py_CLEAR(self->first);
         Py_CLEAR(self->last);
         return 0;
     }

     static void
     Custom_dealloc(PyObject *op)
     {
         PyObject_GC_UnTrack(op);
         (void)Custom_clear(op);
         Py_TYPE(op)->tp_free(op);
     }

     static PyObject *
     Custom_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     {
         CustomObject *self;
         self = (CustomObject *) type->tp_alloc(type, 0);
         if (self != NULL) {
             self->first = Py_GetConstant(Py_CONSTANT_EMPTY_STR);
             if (self->first == NULL) {
                 Py_DECREF(self);
                 return NULL;
             }
             self->last = Py_GetConstant(Py_CONSTANT_EMPTY_STR);
             if (self->last == NULL) {
                 Py_DECREF(self);
                 return NULL;
             }
             self->number = 0;
         }
         return (PyObject *) self;
     }

     static int
     Custom_init(PyObject *op, PyObject *args, PyObject *kwds)
     {
         CustomObject *self = (CustomObject *) op;
         static char *kwlist[] = {"first", "last", "number", NULL};
         PyObject *first = NULL, *last = NULL;

         if (!PyArg_ParseTupleAndKeywords(args, kwds, "|UUi", kwlist,
                                          &first, &last,
                                          &self->number))
             return -1;

         if (first) {
             Py_SETREF(self->first, Py_NewRef(first));
         }
         if (last) {
             Py_SETREF(self->last, Py_NewRef(last));
         }
         return 0;
     }

     static PyMemberDef Custom_members[] = {
         {"number", Py_T_INT, offsetof(CustomObject, number), 0,
          "custom number"},
         {NULL}  /* Sentinel */
     };

     static PyObject *
     Custom_getfirst(PyObject *op, void *closure)
     {
         CustomObject *self = (CustomObject *) op;
         return Py_NewRef(self->first);
     }

     static int
     Custom_setfirst(PyObject *op, PyObject *value, void *closure)
     {
         CustomObject *self = (CustomObject *) op;
         if (value == NULL) {
             PyErr_SetString(PyExc_TypeError, "Cannot delete the first attribute");
             return -1;
         }
         if (!PyUnicode_Check(value)) {
             PyErr_SetString(PyExc_TypeError,
                             "The first attribute value must be a string");
             return -1;
         }
         Py_XSETREF(self->first, Py_NewRef(value));
         return 0;
     }

     static PyObject *
     Custom_getlast(PyObject *op, void *closure)
     {
         CustomObject *self = (CustomObject *) op;
         return Py_NewRef(self->last);
     }

     static int
     Custom_setlast(PyObject *op, PyObject *value, void *closure)
     {
         CustomObject *self = (CustomObject *) op;
         if (value == NULL) {
             PyErr_SetString(PyExc_TypeError, "Cannot delete the last attribute");
             return -1;
         }
         if (!PyUnicode_Check(value)) {
             PyErr_SetString(PyExc_TypeError,
                             "The last attribute value must be a string");
             return -1;
         }
         Py_XSETREF(self->last, Py_NewRef(value));
         return 0;
     }

     static PyGetSetDef Custom_getsetters[] = {
         {"first", Custom_getfirst, Custom_setfirst,
          "first name", NULL},
         {"last", Custom_getlast, Custom_setlast,
          "last name", NULL},
         {NULL}  /* Sentinel */
     };

     static PyObject *
     Custom_name(PyObject *op, PyObject *Py_UNUSED(dummy))
     {
         CustomObject *self = (CustomObject *) op;
         return PyUnicode_FromFormat("%S %S", self->first, self->last);
     }

     static PyMethodDef Custom_methods[] = {
         {"name", Custom_name, METH_NOARGS,
          "Return the name, combining the first and last name"
         },
         {NULL}  /* Sentinel */
     };

     static PyTypeObject CustomType = {
         .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
         .tp_name = "custom4.Custom",
         .tp_doc = PyDoc_STR("Custom objects"),
         .tp_basicsize = sizeof(CustomObject),
         .tp_itemsize = 0,
         .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
         .tp_new = Custom_new,
         .tp_init = Custom_init,
         .tp_dealloc = Custom_dealloc,
         .tp_traverse = Custom_traverse,
         .tp_clear = Custom_clear,
         .tp_members = Custom_members,
         .tp_methods = Custom_methods,
         .tp_getset = Custom_getsetters,
     };

     static int
     custom_module_exec(PyObject *m)
     {
         if (PyType_Ready(&CustomType) < 0) {
             return -1;
         }

         if (PyModule_AddObjectRef(m, "Custom", (PyObject *) &CustomType) < 0) {
             return -1;
         }

         return 0;
     }

     static PyModuleDef_Slot custom_module_slots[] = {
         {Py_mod_exec, custom_module_exec},
         {Py_mod_multiple_interpreters, Py_MOD_MULTIPLE_INTERPRETERS_NOT_SUPPORTED},
         {0, NULL}
     };

     static PyModuleDef custom_module = {
         .m_base = PyModuleDef_HEAD_INIT,
         .m_name = "custom4",
         .m_doc = "Example module that creates an extension type.",
         .m_size = 0,
         .m_slots = custom_module_slots,
     };

     PyMODINIT_FUNC
     PyInit_custom4(void)
     {
         return PyModuleDef_Init(&custom_module);
     }

First, the traversal method lets the cyclic GC know about subobjects
that could participate in cycles:

     static int
     Custom_traverse(PyObject *op, visitproc visit, void *arg)
     {
         CustomObject *self = (CustomObject *) op;
         int vret;
         if (self->first) {
             vret = visit(self->first, arg);
             if (vret != 0)
                 return vret;
         }
         if (self->last) {
             vret = visit(self->last, arg);
             if (vret != 0)
                 return vret;
         }
         return 0;
     }

For each subobject that can participate in cycles, we need to call the
‘visit()’ function, which is passed to the traversal method.  The
‘visit()’ function takes as arguments the subobject and the extra
argument 'arg' passed to the traversal method.  It returns an integer
value that must be returned if it is non-zero.

Python provides a *note Py_VISIT(): 4ec2. macro that automates calling
visit functions.  With *note Py_VISIT(): 4ec2, we can minimize the
amount of boilerplate in ‘Custom_traverse’:

     static int
     Custom_traverse(PyObject *op, visitproc visit, void *arg)
     {
         CustomObject *self = (CustomObject *) op;
         Py_VISIT(self->first);
         Py_VISIT(self->last);
         return 0;
     }

     Nota: The *note tp_traverse: 983. implementation must name its
     arguments exactly 'visit' and 'arg' in order to use *note
     Py_VISIT(): 4ec2.

Second, we need to provide a method for clearing any subobjects that can
participate in cycles:

     static int
     Custom_clear(PyObject *op)
     {
         CustomObject *self = (CustomObject *) op;
         Py_CLEAR(self->first);
         Py_CLEAR(self->last);
         return 0;
     }

Notice the use of the *note Py_CLEAR(): 799. macro.  It is the
recommended and safe way to clear data attributes of arbitrary types
while decrementing their reference counts.  If you were to call *note
Py_XDECREF(): 993. instead on the attribute before setting it to ‘NULL’,
there is a possibility that the attribute’s destructor would call back
into code that reads the attribute again ('especially' if there is a
reference cycle).

     Nota: You could emulate *note Py_CLEAR(): 799. by writing:

          PyObject *tmp;
          tmp = self->first;
          self->first = NULL;
          Py_XDECREF(tmp);

     Nevertheless, it is much easier and less error-prone to always use
     *note Py_CLEAR(): 799. when deleting an attribute.  Don’t try to
     micro-optimize at the expense of robustness!

The deallocator ‘Custom_dealloc’ may call arbitrary code when clearing
attributes.  It means the circular GC can be triggered inside the
function.  Since the GC assumes reference count is not zero, we need to
untrack the object from the GC by calling *note PyObject_GC_UnTrack():
170c. before clearing members.  Here is our reimplemented deallocator
using *note PyObject_GC_UnTrack(): 170c. and ‘Custom_clear’:

     static void
     Custom_dealloc(PyObject *op)
     {
         PyObject_GC_UnTrack(op);
         (void)Custom_clear(op);
         Py_TYPE(op)->tp_free(op);
     }

Finally, we add the *note Py_TPFLAGS_HAVE_GC: 982. flag to the class
flags:

     .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,

That’s pretty much it.  If we had written custom *note tp_alloc: 4eb9.
or *note tp_free: 4eb8. handlers, we’d need to modify them for cyclic
garbage collection.  Most extensions will use the versions automatically
provided.

   ---------- Footnotes ----------

   (1) Also, even with our attributes restricted to strings instances,
the user could pass arbitrary *note str: 169. subclasses and therefore
still create reference cycles.


File: python.info,  Node: Subclassing other types,  Prev: Supporting cyclic garbage collection,  Up: Defining Extension Types Tutorial

6.2.2.5 Subclassing other types
...............................

It is possible to create new extension types that are derived from
existing types.  It is easiest to inherit from the built in types, since
an extension can easily use the *note PyTypeObject: c9e. it needs.  It
can be difficult to share these *note PyTypeObject: c9e. structures
between extension modules.

In this example we will create a ‘SubList’ type that inherits from the
built-in *note list: 24d. type.  The new type will be completely
compatible with regular lists, but will have an additional ‘increment()’
method that increases an internal counter:

     >>> import sublist
     >>> s = sublist.SubList(range(3))
     >>> s.extend(s)
     >>> print(len(s))
     6
     >>> print(s.increment())
     1
     >>> print(s.increment())
     2

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>

     typedef struct {
         PyListObject list;
         int state;
     } SubListObject;

     static PyObject *
     SubList_increment(PyObject *op, PyObject *Py_UNUSED(dummy))
     {
         SubListObject *self = (SubListObject *) op;
         self->state++;
         return PyLong_FromLong(self->state);
     }

     static PyMethodDef SubList_methods[] = {
         {"increment", SubList_increment, METH_NOARGS,
          PyDoc_STR("increment state counter")},
         {NULL},
     };

     static int
     SubList_init(PyObject *op, PyObject *args, PyObject *kwds)
     {
         SubListObject *self = (SubListObject *) op;
         if (PyList_Type.tp_init(op, args, kwds) < 0)
             return -1;
         self->state = 0;
         return 0;
     }

     static PyTypeObject SubListType = {
         .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
         .tp_name = "sublist.SubList",
         .tp_doc = PyDoc_STR("SubList objects"),
         .tp_basicsize = sizeof(SubListObject),
         .tp_itemsize = 0,
         .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
         .tp_init = SubList_init,
         .tp_methods = SubList_methods,
     };

     static int
     sublist_module_exec(PyObject *m)
     {
         SubListType.tp_base = &PyList_Type;
         if (PyType_Ready(&SubListType) < 0) {
             return -1;
         }

         if (PyModule_AddObjectRef(m, "SubList", (PyObject *) &SubListType) < 0) {
             return -1;
         }

         return 0;
     }

     static PyModuleDef_Slot sublist_module_slots[] = {
         {Py_mod_exec, sublist_module_exec},
         {Py_mod_multiple_interpreters, Py_MOD_MULTIPLE_INTERPRETERS_NOT_SUPPORTED},
         {0, NULL}
     };

     static PyModuleDef sublist_module = {
         .m_base = PyModuleDef_HEAD_INIT,
         .m_name = "sublist",
         .m_doc = "Example module that creates an extension type.",
         .m_size = 0,
         .m_slots = sublist_module_slots,
     };

     PyMODINIT_FUNC
     PyInit_sublist(void)
     {
         return PyModuleDef_Init(&sublist_module);
     }

As you can see, the source code closely resembles the ‘Custom’ examples
in previous sections.  We will break down the main differences between
them.

     typedef struct {
         PyListObject list;
         int state;
     } SubListObject;

The primary difference for derived type objects is that the base type’s
object structure must be the first value.  The base type will already
include the *note PyObject_HEAD(): 14e5. at the beginning of its
structure.

When a Python object is a ‘SubList’ instance, its ‘PyObject *’ pointer
can be safely cast to both ‘PyListObject *’ and ‘SubListObject *’:

     static int
     SubList_init(PyObject *op, PyObject *args, PyObject *kwds)
     {
         SubListObject *self = (SubListObject *) op;
         if (PyList_Type.tp_init(op, args, kwds) < 0)
             return -1;
         self->state = 0;
         return 0;
     }

We see above how to call through to the *note __init__(): 8c0. method of
the base type.

This pattern is important when writing a type with custom *note tp_new:
7a0. and *note tp_dealloc: 4ea5. members.  The *note tp_new: 7a0.
handler should not actually create the memory for the object with its
*note tp_alloc: 4eb9, but let the base class handle it by calling its
own *note tp_new: 7a0.

The *note PyTypeObject: c9e. struct supports a *note tp_base: 235c.
specifying the type’s concrete base class.  Due to cross-platform
compiler issues, you can’t fill that field directly with a reference to
*note PyList_Type: 4ec4.; it should be done in the *note Py_mod_exec:
b77. function:

     static int
     sublist_module_exec(PyObject *m)
     {
         SubListType.tp_base = &PyList_Type;
         if (PyType_Ready(&SubListType) < 0) {
             return -1;
         }

         if (PyModule_AddObjectRef(m, "SubList", (PyObject *) &SubListType) < 0) {
             return -1;
         }

         return 0;
     }

Before calling *note PyType_Ready(): 981, the type structure must have
the *note tp_base: 235c. slot filled in.  When we are deriving an
existing type, it is not necessary to fill out the *note tp_alloc: 4eb9.
slot with *note PyType_GenericNew(): 4eb5. – the allocation function
from the base type will be inherited.

After that, calling *note PyType_Ready(): 981. and adding the type
object to the module is the same as with the basic ‘Custom’ examples.


File: python.info,  Node: Defining Extension Types Assorted Topics,  Next: Building C and C++ Extensions,  Prev: Defining Extension Types Tutorial,  Up: Creating extensions without third party tools

6.2.3 Defining Extension Types: Assorted Topics
-----------------------------------------------

This section aims to give a quick fly-by on the various type methods you
can implement and what they do.

Here is the definition of *note PyTypeObject: c9e, with some fields only
used in *note debug builds: 50a. omitted:

     typedef struct _typeobject {
         PyObject_VAR_HEAD
         const char *tp_name; /* For printing, in format "<module>.<name>" */
         Py_ssize_t tp_basicsize, tp_itemsize; /* For allocation */

         /* Methods to implement standard operations */

         destructor tp_dealloc;
         Py_ssize_t tp_vectorcall_offset;
         getattrfunc tp_getattr;
         setattrfunc tp_setattr;
         PyAsyncMethods *tp_as_async; /* formerly known as tp_compare (Python 2)
                                         or tp_reserved (Python 3) */
         reprfunc tp_repr;

         /* Method suites for standard classes */

         PyNumberMethods *tp_as_number;
         PySequenceMethods *tp_as_sequence;
         PyMappingMethods *tp_as_mapping;

         /* More standard operations (here for binary compatibility) */

         hashfunc tp_hash;
         ternaryfunc tp_call;
         reprfunc tp_str;
         getattrofunc tp_getattro;
         setattrofunc tp_setattro;

         /* Functions to access object as input/output buffer */
         PyBufferProcs *tp_as_buffer;

         /* Flags to define presence of optional/expanded features */
         unsigned long tp_flags;

         const char *tp_doc; /* Documentation string */

         /* Assigned meaning in release 2.0 */
         /* call function for all accessible objects */
         traverseproc tp_traverse;

         /* delete references to contained objects */
         inquiry tp_clear;

         /* Assigned meaning in release 2.1 */
         /* rich comparisons */
         richcmpfunc tp_richcompare;

         /* weak reference enabler */
         Py_ssize_t tp_weaklistoffset;

         /* Iterators */
         getiterfunc tp_iter;
         iternextfunc tp_iternext;

         /* Attribute descriptor and subclassing stuff */
         PyMethodDef *tp_methods;
         PyMemberDef *tp_members;
         PyGetSetDef *tp_getset;
         // Strong reference on a heap type, borrowed reference on a static type
         PyTypeObject *tp_base;
         PyObject *tp_dict;
         descrgetfunc tp_descr_get;
         descrsetfunc tp_descr_set;
         Py_ssize_t tp_dictoffset;
         initproc tp_init;
         allocfunc tp_alloc;
         newfunc tp_new;
         freefunc tp_free; /* Low-level free-memory routine */
         inquiry tp_is_gc; /* For PyObject_IS_GC */
         PyObject *tp_bases;
         PyObject *tp_mro; /* method resolution order */
         PyObject *tp_cache; /* no longer used */
         void *tp_subclasses;  /* for static builtin types this is an index */
         PyObject *tp_weaklist; /* not used for static builtin types */
         destructor tp_del;

         /* Type attribute cache version tag. Added in version 2.6.
          * If zero, the cache is invalid and must be initialized.
          */
         unsigned int tp_version_tag;

         destructor tp_finalize;
         vectorcallfunc tp_vectorcall;

         /* bitset of which type-watchers care about this type */
         unsigned char tp_watched;

         /* Number of tp_version_tag values used.
          * Set to _Py_ATTR_CACHE_UNUSED if the attribute cache is
          * disabled for this type (e.g. due to custom MRO entries).
          * Otherwise, limited to MAX_VERSIONS_PER_CLASS (defined elsewhere).
          */
         uint16_t tp_versions_used;
     } PyTypeObject;

Now that’s a 'lot' of methods.  Don’t worry too much though – if you
have a type you want to define, the chances are very good that you will
only implement a handful of these.

As you probably expect by now, we’re going to go over this and give more
information about the various handlers.  We won’t go in the order they
are defined in the structure, because there is a lot of historical
baggage that impacts the ordering of the fields.  It’s often easiest to
find an example that includes the fields you need and then change the
values to suit your new type.

     const char *tp_name; /* For printing */

The name of the type – as mentioned in the previous chapter, this will
appear in various places, almost entirely for diagnostic purposes.  Try
to choose something that will be helpful in such a situation!

     Py_ssize_t tp_basicsize, tp_itemsize; /* For allocation */

These fields tell the runtime how much memory to allocate when new
objects of this type are created.  Python has some built-in support for
variable length structures (think: strings, tuples) which is where the
*note tp_itemsize: 23a1. field comes in.  This will be dealt with later.

     const char *tp_doc;

Here you can put a string (or its address) that you want returned when
the Python script references ‘obj.__doc__’ to retrieve the doc string.

Now we come to the basic type methods – the ones most extension types
will implement.

* Menu:

* Finalization and De-allocation::
* Object Presentation::
* Attribute Management::
* Object Comparison::
* Abstract Protocol Support::
* Weak Reference Support::
* More Suggestions::


File: python.info,  Node: Finalization and De-allocation,  Next: Object Presentation,  Up: Defining Extension Types Assorted Topics

6.2.3.1 Finalization and De-allocation
......................................

     destructor tp_dealloc;

This function is called when the reference count of the instance of your
type is reduced to zero and the Python interpreter wants to reclaim it.
If your type has memory to free or other clean-up to perform, you can
put it here.  The object itself needs to be freed here as well.  Here is
an example of this function:

     static void
     newdatatype_dealloc(PyObject *op)
     {
         newdatatypeobject *self = (newdatatypeobject *) op;
         free(self->obj_UnderlyingDatatypePtr);
         Py_TYPE(self)->tp_free(self);
     }

If your type supports garbage collection, the destructor should call
*note PyObject_GC_UnTrack(): 170c. before clearing any member fields:

     static void
     newdatatype_dealloc(PyObject *op)
     {
         newdatatypeobject *self = (newdatatypeobject *) op;
         PyObject_GC_UnTrack(op);
         Py_CLEAR(self->other_obj);
         ...
         Py_TYPE(self)->tp_free(self);
     }

One important requirement of the deallocator function is that it leaves
any pending exceptions alone.  This is important since deallocators are
frequently called as the interpreter unwinds the Python stack; when the
stack is unwound due to an exception (rather than normal returns),
nothing is done to protect the deallocators from seeing that an
exception has already been set.  Any actions which a deallocator
performs which may cause additional Python code to be executed may
detect that an exception has been set.  This can lead to misleading
errors from the interpreter.  The proper way to protect against this is
to save a pending exception before performing the unsafe action, and
restoring it when done.  This can be done using the *note PyErr_Fetch():
428. and *note PyErr_Restore(): 42b. functions:

     static void
     my_dealloc(PyObject *obj)
     {
         MyObject *self = (MyObject *) obj;
         PyObject *cbresult;

         if (self->my_callback != NULL) {
             PyObject *err_type, *err_value, *err_traceback;

             /* This saves the current exception state */
             PyErr_Fetch(&err_type, &err_value, &err_traceback);

             cbresult = PyObject_CallNoArgs(self->my_callback);
             if (cbresult == NULL) {
                PyErr_WriteUnraisable(self->my_callback);
             }
             else {
                 Py_DECREF(cbresult);
             }

             /* This restores the saved exception state */
             PyErr_Restore(err_type, err_value, err_traceback);

             Py_DECREF(self->my_callback);
         }
         Py_TYPE(self)->tp_free(self);
     }

     Nota: There are limitations to what you can safely do in a
     deallocator function.  First, if your type supports garbage
     collection (using *note tp_traverse: 983. and/or *note tp_clear:
     4ecb.), some of the object’s members can have been cleared or
     finalized by the time *note tp_dealloc: 4ea5. is called.  Second,
     in *note tp_dealloc: 4ea5, your object is in an unstable state: its
     reference count is equal to zero.  Any call to a non-trivial object
     or API (as in the example above) might end up calling *note
     tp_dealloc: 4ea5. again, causing a double free and a crash.

     Starting with Python 3.4, it is recommended not to put any complex
     finalization code in *note tp_dealloc: 4ea5, and instead use the
     new *note tp_finalize: c9f. type method.

     Vedi anche
     ..........

     PEP 442(1) explains the new finalization scheme.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0442/


File: python.info,  Node: Object Presentation,  Next: Attribute Management,  Prev: Finalization and De-allocation,  Up: Defining Extension Types Assorted Topics

6.2.3.2 Object Presentation
...........................

In Python, there are two ways to generate a textual representation of an
object: the *note repr(): 1c1. function, and the *note str(): 169.
function.  (The *note print(): 1177. function just calls *note str():
169.)  These handlers are both optional.

     reprfunc tp_repr;
     reprfunc tp_str;

The *note tp_repr: 4ecd. handler should return a string object
containing a representation of the instance for which it is called.
Here is a simple example:

     static PyObject *
     newdatatype_repr(PyObject *op)
     {
         newdatatypeobject *self = (newdatatypeobject *) op;
         return PyUnicode_FromFormat("Repr-ified_newdatatype{{size:%d}}",
                                     self->obj_UnderlyingDatatypePtr->size);
     }

If no *note tp_repr: 4ecd. handler is specified, the interpreter will
supply a representation that uses the type’s *note tp_name: 1c98. and a
uniquely identifying value for the object.

The *note tp_str: 4ece. handler is to *note str(): 169. what the *note
tp_repr: 4ecd. handler described above is to *note repr(): 1c1.; that
is, it is called when Python code calls *note str(): 169. on an instance
of your object.  Its implementation is very similar to the *note
tp_repr: 4ecd. function, but the resulting string is intended for human
consumption.  If *note tp_str: 4ece. is not specified, the *note
tp_repr: 4ecd. handler is used instead.

Here is a simple example:

     static PyObject *
     newdatatype_str(PyObject *op)
     {
         newdatatypeobject *self = (newdatatypeobject *) op;
         return PyUnicode_FromFormat("Stringified_newdatatype{{size:%d}}",
                                     self->obj_UnderlyingDatatypePtr->size);
     }


File: python.info,  Node: Attribute Management,  Next: Object Comparison,  Prev: Object Presentation,  Up: Defining Extension Types Assorted Topics

6.2.3.3 Attribute Management
............................

For every object which can support attributes, the corresponding type
must provide the functions that control how the attributes are resolved.
There needs to be a function which can retrieve attributes (if any are
defined), and another to set attributes (if setting attributes is
allowed).  Removing an attribute is a special case, for which the new
value passed to the handler is ‘NULL’.

Python supports two pairs of attribute handlers; a type that supports
attributes only needs to implement the functions for one pair.  The
difference is that one pair takes the name of the attribute as a char*,
while the other accepts a *note PyObject: 5df.*.  Each type can use
whichever pair makes more sense for the implementation’s convenience.

     getattrfunc  tp_getattr;        /* char * version */
     setattrfunc  tp_setattr;
     /* ... */
     getattrofunc tp_getattro;       /* PyObject * version */
     setattrofunc tp_setattro;

If accessing attributes of an object is always a simple operation (this
will be explained shortly), there are generic implementations which can
be used to provide the *note PyObject: 5df.* version of the attribute
management functions.  The actual need for type-specific attribute
handlers almost completely disappeared starting with Python 2.2, though
there are many examples which have not been updated to use some of the
new generic mechanism that is available.

* Menu:

* Generic Attribute Management::
* Type-specific Attribute Management::


File: python.info,  Node: Generic Attribute Management,  Next: Type-specific Attribute Management,  Up: Attribute Management

6.2.3.4 Generic Attribute Management
....................................

Most extension types only use 'simple' attributes.  So, what makes the
attributes simple?  There are only a couple of conditions that must be
met:

  1. The name of the attributes must be known when *note PyType_Ready():
     981. is called.

  2. No special processing is needed to record that an attribute was
     looked up or set, nor do actions need to be taken based on the
     value.

Note that this list does not place any restrictions on the values of the
attributes, when the values are computed, or how relevant data is
stored.

When *note PyType_Ready(): 981. is called, it uses three tables
referenced by the type object to create *note descriptor: 1869.s which
are placed in the dictionary of the type object.  Each descriptor
controls access to one attribute of the instance object.  Each of the
tables is optional; if all three are ‘NULL’, instances of the type will
only have attributes that are inherited from their base type, and should
leave the *note tp_getattro: 1a4c. and *note tp_setattro: 4ed1. fields
‘NULL’ as well, allowing the base type to handle attributes.

The tables are declared as three fields of the type object:

     struct PyMethodDef *tp_methods;
     struct PyMemberDef *tp_members;
     struct PyGetSetDef *tp_getset;

If *note tp_methods: 4ebd. is not ‘NULL’, it must refer to an array of
*note PyMethodDef: 16de. structures.  Each entry in the table is an
instance of this structure:

     typedef struct PyMethodDef {
         const char  *ml_name;       /* method name */
         PyCFunction  ml_meth;       /* implementation function */
         int          ml_flags;      /* flags */
         const char  *ml_doc;        /* docstring */
     } PyMethodDef;

One entry should be defined for each method provided by the type; no
entries are needed for methods inherited from a base type.  One
additional entry is needed at the end; it is a sentinel that marks the
end of the array.  The *note ml_name: 4ed2. field of the sentinel must
be ‘NULL’.

The second table is used to define attributes which map directly to data
stored in the instance.  A variety of primitive C types are supported,
and access may be read-only or read-write.  The structures in the table
are defined as:

     typedef struct PyMemberDef {
         const char *name;
         int         type;
         int         offset;
         int         flags;
         const char *doc;
     } PyMemberDef;

For each entry in the table, a *note descriptor: 1869. will be
constructed and added to the type which will be able to extract a value
from the instance structure.  The *note type: 4ed3. field should contain
a type code like *note Py_T_INT: 7ad. or *note Py_T_DOUBLE: 7ae.; the
value will be used to determine how to convert Python values to and from
C values.  The *note flags: 4ed4. field is used to store flags which
control how the attribute can be accessed: you can set it to *note
Py_READONLY: 7af. to prevent Python code from setting it.

An interesting advantage of using the *note tp_members: 4ebb. table to
build descriptors that are used at runtime is that any attribute defined
this way can have an associated doc string simply by providing the text
in the table.  An application can use the introspection API to retrieve
the descriptor from the class object, and get the doc string using its
*note __doc__: 207f. attribute.

As with the *note tp_methods: 4ebd. table, a sentinel entry with a *note
ml_name: 4ed2. value of ‘NULL’ is required.


File: python.info,  Node: Type-specific Attribute Management,  Prev: Generic Attribute Management,  Up: Attribute Management

6.2.3.5 Type-specific Attribute Management
..........................................

For simplicity, only the char* version will be demonstrated here; the
type of the name parameter is the only difference between the char* and
*note PyObject: 5df.* flavors of the interface.  This example
effectively does the same thing as the generic example above, but does
not use the generic support added in Python 2.2.  It explains how the
handler functions are called, so that if you do need to extend their
functionality, you’ll understand what needs to be done.

The *note tp_getattr: 4ed6. handler is called when the object requires
an attribute look-up.  It is called in the same situations where the
*note __getattr__(): 6fb. method of a class would be called.

Here is an example:

     static PyObject *
     newdatatype_getattr(PyObject *op, char *name)
     {
         newdatatypeobject *self = (newdatatypeobject *) op;
         if (strcmp(name, "data") == 0) {
             return PyLong_FromLong(self->data);
         }

         PyErr_Format(PyExc_AttributeError,
                      "'%.100s' object has no attribute '%.400s'",
                      Py_TYPE(self)->tp_name, name);
         return NULL;
     }

The *note tp_setattr: 4ed7. handler is called when the *note
__setattr__(): 2362. or *note __delattr__(): 2363. method of a class
instance would be called.  When an attribute should be deleted, the
third parameter will be ‘NULL’.  Here is an example that simply raises
an exception; if this were really all you wanted, the *note tp_setattr:
4ed7. handler should be set to ‘NULL’.

     static int
     newdatatype_setattr(PyObject *op, char *name, PyObject *v)
     {
         PyErr_Format(PyExc_RuntimeError, "Read-only attribute: %s", name);
         return -1;
     }


File: python.info,  Node: Object Comparison,  Next: Abstract Protocol Support,  Prev: Attribute Management,  Up: Defining Extension Types Assorted Topics

6.2.3.6 Object Comparison
.........................

     richcmpfunc tp_richcompare;

The *note tp_richcompare: 4ed9. handler is called when comparisons are
needed.  It is analogous to the *note rich comparison methods: 2394,
like ‘__lt__()’, and also called by *note PyObject_RichCompare(): 4eda.
and *note PyObject_RichCompareBool(): 1d74.

This function is called with two Python objects and the operator as
arguments, where the operator is one of ‘Py_EQ’, ‘Py_NE’, ‘Py_LE’,
‘Py_GE’, ‘Py_LT’ or ‘Py_GT’.  It should compare the two objects with
respect to the specified operator and return ‘Py_True’ or ‘Py_False’ if
the comparison is successful, ‘Py_NotImplemented’ to indicate that
comparison is not implemented and the other object’s comparison method
should be tried, or ‘NULL’ if an exception was set.

Here is a sample implementation, for a datatype that is considered equal
if the size of an internal pointer is equal:

     static PyObject *
     newdatatype_richcmp(PyObject *lhs, PyObject *rhs, int op)
     {
         newdatatypeobject *obj1 = (newdatatypeobject *) lhs;
         newdatatypeobject *obj2 = (newdatatypeobject *) rhs;
         PyObject *result;
         int c, size1, size2;

         /* code to make sure that both arguments are of type
            newdatatype omitted */

         size1 = obj1->obj_UnderlyingDatatypePtr->size;
         size2 = obj2->obj_UnderlyingDatatypePtr->size;

         switch (op) {
         case Py_LT: c = size1 <  size2; break;
         case Py_LE: c = size1 <= size2; break;
         case Py_EQ: c = size1 == size2; break;
         case Py_NE: c = size1 != size2; break;
         case Py_GT: c = size1 >  size2; break;
         case Py_GE: c = size1 >= size2; break;
         }
         result = c ? Py_True : Py_False;
         return Py_NewRef(result);
      }


File: python.info,  Node: Abstract Protocol Support,  Next: Weak Reference Support,  Prev: Object Comparison,  Up: Defining Extension Types Assorted Topics

6.2.3.7 Abstract Protocol Support
.................................

Python supports a variety of 'abstract' “protocols;” the specific
interfaces provided to use these interfaces are documented in *note
Abstract Objects Layer: 4edc.

A number of these abstract interfaces were defined early in the
development of the Python implementation.  In particular, the number,
mapping, and sequence protocols have been part of Python since the
beginning.  Other protocols have been added over time.  For protocols
which depend on several handler routines from the type implementation,
the older protocols have been defined as optional blocks of handlers
referenced by the type object.  For newer protocols there are additional
slots in the main type object, with a flag bit being set to indicate
that the slots are present and should be checked by the interpreter.
(The flag bit does not indicate that the slot values are non-‘NULL’.
The flag may be set to indicate the presence of a slot, but a slot may
still be unfilled.)

     PyNumberMethods   *tp_as_number;
     PySequenceMethods *tp_as_sequence;
     PyMappingMethods  *tp_as_mapping;

If you wish your object to be able to act like a number, a sequence, or
a mapping object, then you place the address of a structure that
implements the C type *note PyNumberMethods: 1625, *note
PySequenceMethods: 4edd, or *note PyMappingMethods: 4ede, respectively.
It is up to you to fill in this structure with appropriate values.  You
can find examples of the use of each of these in the ‘Objects’ directory
of the Python source distribution.

     hashfunc tp_hash;

This function, if you choose to provide it, should return a hash number
for an instance of your data type.  Here is a simple example:

     static Py_hash_t
     newdatatype_hash(PyObject *op)
     {
         newdatatypeobject *self = (newdatatypeobject *) op;
         Py_hash_t result;
         result = self->some_size + 32767 * self->some_number;
         if (result == -1) {
             result = -2;
         }
         return result;
     }

*note Py_hash_t: 146b. is a signed integer type with a platform-varying
width.  Returning ‘-1’ from *note tp_hash: 4edf. indicates an error,
which is why you should be careful to avoid returning it when hash
computation is successful, as seen above.

     ternaryfunc tp_call;

This function is called when an instance of your data type is «called»,
for example, if ‘obj1’ is an instance of your data type and the Python
script contains ‘obj1('hello')’, the *note tp_call: 77c. handler is
invoked.

This function takes three arguments:

  1. 'self' is the instance of the data type which is the subject of the
     call.  If the call is ‘obj1('hello')’, then 'self' is ‘obj1’.

  2. 'args' is a tuple containing the arguments to the call.  You can
     use *note PyArg_ParseTuple(): 3c1. to extract the arguments.

  3. 'kwds' is a dictionary of keyword arguments that were passed.  If
     this is non-‘NULL’ and you support keyword arguments, use *note
     PyArg_ParseTupleAndKeywords(): 624. to extract the arguments.  If
     you do not want to support keyword arguments and this is
     non-‘NULL’, raise a *note TypeError: 198. with a message saying
     that keyword arguments are not supported.

Here is a toy ‘tp_call’ implementation:

     static PyObject *
     newdatatype_call(PyObject *op, PyObject *args, PyObject *kwds)
     {
         newdatatypeobject *self = (newdatatypeobject *) op;
         PyObject *result;
         const char *arg1;
         const char *arg2;
         const char *arg3;

         if (!PyArg_ParseTuple(args, "sss:call", &arg1, &arg2, &arg3)) {
             return NULL;
         }
         result = PyUnicode_FromFormat(
             "Returning -- value: [%d] arg1: [%s] arg2: [%s] arg3: [%s]\n",
             self->obj_UnderlyingDatatypePtr->size,
             arg1, arg2, arg3);
         return result;
     }

     /* Iterators */
     getiterfunc tp_iter;
     iternextfunc tp_iternext;

These functions provide support for the iterator protocol.  Both
handlers take exactly one parameter, the instance for which they are
being called, and return a new reference.  In the case of an error, they
should set an exception and return ‘NULL’.  *note tp_iter: 16f6.
corresponds to the Python *note __iter__(): e6b. method, while *note
tp_iternext: 16f7. corresponds to the Python *note __next__(): 14d5.
method.

Any *note iterable: 142f. object must implement the *note tp_iter: 16f6.
handler, which must return an *note iterator: 4c9. object.  Here the
same guidelines apply as for Python classes:

   * For collections (such as lists and tuples) which can support
     multiple independent iterators, a new iterator should be created
     and returned by each call to *note tp_iter: 16f6.

   * Objects which can only be iterated over once (usually due to side
     effects of iteration, such as file objects) can implement *note
     tp_iter: 16f6. by returning a new reference to themselves – and
     should also therefore implement the *note tp_iternext: 16f7.
     handler.

Any *note iterator: 4c9. object should implement both *note tp_iter:
16f6. and *note tp_iternext: 16f7.  An iterator’s *note tp_iter: 16f6.
handler should return a new reference to the iterator.  Its *note
tp_iternext: 16f7. handler should return a new reference to the next
object in the iteration, if there is one.  If the iteration has reached
the end, *note tp_iternext: 16f7. may return ‘NULL’ without setting an
exception, or it may set *note StopIteration: df7. 'in addition' to
returning ‘NULL’; avoiding the exception can yield slightly better
performance.  If an actual error occurs, *note tp_iternext: 16f7. should
always set an exception and return ‘NULL’.


File: python.info,  Node: Weak Reference Support,  Next: More Suggestions,  Prev: Abstract Protocol Support,  Up: Defining Extension Types Assorted Topics

6.2.3.8 Weak Reference Support
..............................

One of the goals of Python’s weak reference implementation is to allow
any type to participate in the weak reference mechanism without
incurring the overhead on performance-critical objects (such as
numbers).

Vedi anche
..........

Documentation for the *note weakref: 11a. module.

For an object to be weakly referenceable, the extension type must set
the ‘Py_TPFLAGS_MANAGED_WEAKREF’ bit of the *note tp_flags: 1c59. field.
The legacy *note tp_weaklistoffset: b81. field should be left as zero.

Concretely, here is how the statically declared type object would look:

     static PyTypeObject TrivialType = {
         PyVarObject_HEAD_INIT(NULL, 0)
         /* ... other members omitted for brevity ... */
         .tp_flags = Py_TPFLAGS_MANAGED_WEAKREF | ...,
     };

The only further addition is that ‘tp_dealloc’ needs to clear any weak
references (by calling *note PyObject_ClearWeakRefs(): 797.):

     static void
     Trivial_dealloc(PyObject *op)
     {
         /* Clear weakrefs first before calling any destructors */
         PyObject_ClearWeakRefs(op);
         /* ... remainder of destruction code omitted for brevity ... */
         Py_TYPE(op)->tp_free(op);
     }


File: python.info,  Node: More Suggestions,  Prev: Weak Reference Support,  Up: Defining Extension Types Assorted Topics

6.2.3.9 More Suggestions
........................

In order to learn how to implement any specific method for your new data
type, get the *note CPython: 906. source code.  Go to the ‘Objects’
directory, then search the C source files for ‘tp_’ plus the function
you want (for example, ‘tp_richcompare’).  You will find examples of the
function you want to implement.

When you need to verify that an object is a concrete instance of the
type you are implementing, use the *note PyObject_TypeCheck(): 1c9d.
function.  A sample of its use might be something like the following:

     if (!PyObject_TypeCheck(some_object, &MyType)) {
         PyErr_SetString(PyExc_TypeError, "arg #1 not a mything");
         return NULL;
     }

Vedi anche
..........

Download CPython source releases.

     ‘https://www.python.org/downloads/source/’

The CPython project on GitHub, where the CPython source code is developed.

     ‘https://github.com/python/cpython’


File: python.info,  Node: Building C and C++ Extensions,  Next: Building C and C++ Extensions on Windows,  Prev: Defining Extension Types Assorted Topics,  Up: Creating extensions without third party tools

6.2.4 Building C and C++ Extensions
-----------------------------------

A C extension for CPython is a shared library (for example, a ‘.so’ file
on Linux, ‘.pyd’ on Windows), which exports an 'initialization
function'.

See *note Defining extension modules: 4ee5. for details.
* Menu:

* Building C and C++ Extensions with setuptools::


File: python.info,  Node: Building C and C++ Extensions with setuptools,  Up: Building C and C++ Extensions

6.2.4.1 Building C and C++ Extensions with setuptools
.....................................................

Building, packaging and distributing extension modules is best done with
third-party tools, and is out of scope of this document.  One suitable
tool is Setuptools, whose documentation can be found at
‘https://setuptools.pypa.io/en/latest/setuptools.html’.

The *note distutils: 3d. module, which was included in the standard
library until Python 3.12, is now maintained as part of Setuptools.


File: python.info,  Node: Building C and C++ Extensions on Windows,  Prev: Building C and C++ Extensions,  Up: Creating extensions without third party tools

6.2.5 Building C and C++ Extensions on Windows
----------------------------------------------

This chapter briefly explains how to create a Windows extension module
for Python using Microsoft Visual C++, and follows with more detailed
background information on how it works.  The explanatory material is
useful for both the Windows programmer learning to build Python
extensions and the Unix programmer interested in producing software
which can be successfully built on both Unix and Windows.

Module authors are encouraged to use the distutils approach for building
extension modules, instead of the one described in this section.  You
will still need the C compiler that was used to build Python; typically
Microsoft Visual C++.

     Nota: This chapter mentions a number of filenames that include an
     encoded Python version number.  These filenames are represented
     with the version number shown as ‘XY’; in practice, ‘'X'’ will be
     the major version number and ‘'Y'’ will be the minor version number
     of the Python release you’re working with.  For example, if you are
     using Python 2.2.1, ‘XY’ will actually be ‘22’.

* Menu:

* A Cookbook Approach::
* Differences Between Unix and Windows::
* Using DLLs in Practice::


File: python.info,  Node: A Cookbook Approach,  Next: Differences Between Unix and Windows,  Up: Building C and C++ Extensions on Windows

6.2.5.1 A Cookbook Approach
...........................

There are two approaches to building extension modules on Windows, just
as there are on Unix: use the ‘setuptools’ package to control the build
process, or do things manually.  The setuptools approach works well for
most extensions; documentation on using ‘setuptools’ to build and
package extension modules is available in *note Building C and C++
Extensions with setuptools: 10fc.  If you find you really need to do
things manually, it may be instructive to study the project file for the
winsound(1) standard library module.

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/PCbuild/winsound.vcxproj


File: python.info,  Node: Differences Between Unix and Windows,  Next: Using DLLs in Practice,  Prev: A Cookbook Approach,  Up: Building C and C++ Extensions on Windows

6.2.5.2 Differences Between Unix and Windows
............................................

Unix and Windows use completely different paradigms for run-time loading
of code.  Before you try to build a module that can be dynamically
loaded, be aware of how your system works.

In Unix, a shared object (‘.so’) file contains code to be used by the
program, and also the names of functions and data that it expects to
find in the program.  When the file is joined to the program, all
references to those functions and data in the file’s code are changed to
point to the actual locations in the program where the functions and
data are placed in memory.  This is basically a link operation.

In Windows, a dynamic-link library (‘.dll’) file has no dangling
references.  Instead, an access to functions or data goes through a
lookup table.  So the DLL code does not have to be fixed up at runtime
to refer to the program’s memory; instead, the code already uses the
DLL’s lookup table, and the lookup table is modified at runtime to point
to the functions and data.

In Unix, there is only one type of library file (‘.a’) which contains
code from several object files (‘.o’).  During the link step to create a
shared object file (‘.so’), the linker may find that it doesn’t know
where an identifier is defined.  The linker will look for it in the
object files in the libraries; if it finds it, it will include all the
code from that object file.

In Windows, there are two types of library, a static library and an
import library (both called ‘.lib’).  A static library is like a Unix
‘.a’ file; it contains code to be included as necessary.  An import
library is basically used only to reassure the linker that a certain
identifier is legal, and will be present in the program when the DLL is
loaded.  So the linker uses the information from the import library to
build the lookup table for using identifiers that are not included in
the DLL. When an application or a DLL is linked, an import library may
be generated, which will need to be used for all future DLLs that depend
on the symbols in the application or DLL.

Suppose you are building two dynamic-load modules, B and C, which should
share another block of code A. On Unix, you would 'not' pass ‘A.a’ to
the linker for ‘B.so’ and ‘C.so’; that would cause it to be included
twice, so that B and C would each have their own copy.  In Windows,
building ‘A.dll’ will also build ‘A.lib’.  You 'do' pass ‘A.lib’ to the
linker for B and C. ‘A.lib’ does not contain code; it just contains
information which will be used at runtime to access A’s code.

In Windows, using an import library is sort of like using ‘import spam’;
it gives you access to spam’s names, but does not create a separate
copy.  On Unix, linking with a library is more like ‘from spam import
*’; it does create a separate copy.

 -- C Macro: Py_NO_LINK_LIB

     Turn off the implicit, ‘#pragma’-based linkage with the Python
     library, performed inside CPython header files.

     Added in version 3.14.


File: python.info,  Node: Using DLLs in Practice,  Prev: Differences Between Unix and Windows,  Up: Building C and C++ Extensions on Windows

6.2.5.3 Using DLLs in Practice
..............................

Windows Python is built in Microsoft Visual C++; using other compilers
may or may not work.  The rest of this section is MSVC++ specific.

When creating DLLs in Windows, you can use the CPython library in two
ways:

  1. By default, inclusion of ‘PC/pyconfig.h’ directly or via ‘Python.h’
     triggers an implicit, configure-aware link with the library.  The
     header file chooses ‘pythonXY_d.lib’ for Debug, ‘pythonXY.lib’ for
     Release, and ‘pythonX.lib’ for Release with the *note Limited API:
     4ef0. enabled.

     To build two DLLs, spam and ni (which uses C functions found in
     spam), you could use these commands:

          cl /LD /I/python/include spam.c
          cl /LD /I/python/include ni.c spam.lib

     The first command created three files: ‘spam.obj’, ‘spam.dll’ and
     ‘spam.lib’.  ‘Spam.dll’ does not contain any Python functions (such
     as *note PyArg_ParseTuple(): 3c1.), but it does know how to find
     the Python code thanks to the implicitly linked ‘pythonXY.lib’.

     The second command created ‘ni.dll’ (and ‘.obj’ and ‘.lib’), which
     knows how to find the necessary functions from spam, and also from
     the Python executable.

  2. Manually by defining *note Py_NO_LINK_LIB: 444. macro before
     including ‘Python.h’.  You must pass ‘pythonXY.lib’ to the linker.

     To build two DLLs, spam and ni (which uses C functions found in
     spam), you could use these commands:

          cl /LD /DPy_NO_LINK_LIB /I/python/include spam.c ../libs/pythonXY.lib
          cl /LD /DPy_NO_LINK_LIB /I/python/include ni.c spam.lib ../libs/pythonXY.lib

     The first command created three files: ‘spam.obj’, ‘spam.dll’ and
     ‘spam.lib’.  ‘Spam.dll’ does not contain any Python functions (such
     as *note PyArg_ParseTuple(): 3c1.), but it does know how to find
     the Python code thanks to ‘pythonXY.lib’.

     The second command created ‘ni.dll’ (and ‘.obj’ and ‘.lib’), which
     knows how to find the necessary functions from spam, and also from
     the Python executable.

Not every identifier is exported to the lookup table.  If you want any
other modules (including Python) to be able to see your identifiers, you
have to say ‘_declspec(dllexport)’, as in ‘void _declspec(dllexport)
initspam(void)’ or ‘PyObject _declspec(dllexport) *NiGetSpamData(void)’.

Developer Studio will throw in a lot of import libraries that you do not
really need, adding about 100K to your executable.  To get rid of them,
use the Project Settings dialog, Link tab, to specify 'ignore default
libraries'.  Add the correct ‘msvcrt`xx'.lib’ to the list of libraries.


File: python.info,  Node: Embedding the CPython runtime in a larger application,  Prev: Creating extensions without third party tools,  Up: Extending and Embedding the Python Interpreter

6.3 Embedding the CPython runtime in a larger application
=========================================================

Sometimes, rather than creating an extension that runs inside the Python
interpreter as the main application, it is desirable to instead embed
the CPython runtime inside a larger application.  This section covers
some of the details involved in doing that successfully.

* Menu:

* Embedding Python in Another Application::


File: python.info,  Node: Embedding Python in Another Application,  Up: Embedding the CPython runtime in a larger application

6.3.1 Embedding Python in Another Application
---------------------------------------------

The previous chapters discussed how to extend Python, that is, how to
extend the functionality of Python by attaching a library of C functions
to it.  It is also possible to do it the other way around: enrich your
C/C++ application by embedding Python in it.  Embedding provides your
application with the ability to implement some of the functionality of
your application in Python rather than C or C++.  This can be used for
many purposes; one example would be to allow users to tailor the
application to their needs by writing some scripts in Python.  You can
also use it yourself if some of the functionality can be written in
Python more easily.

Embedding Python is similar to extending it, but not quite.  The
difference is that when you extend Python, the main program of the
application is still the Python interpreter, while if you embed Python,
the main program may have nothing to do with Python — instead, some
parts of the application occasionally call the Python interpreter to run
some Python code.

So if you are embedding Python, you are providing your own main program.
One of the things this main program has to do is initialize the Python
interpreter.  At the very least, you have to call the function *note
Py_Initialize(): 460.  There are optional calls to pass command line
arguments to Python.  Then later you can call the interpreter from any
part of the application.

There are several different ways to call the interpreter: you can pass a
string containing Python statements to *note PyRun_SimpleString(): 4ef4,
or you can pass a stdio file pointer and a file name (for identification
in error messages only) to *note PyRun_SimpleFile(): 4ef5.  You can also
call the lower-level operations described in the previous chapters to
construct and use Python objects.

Vedi anche
..........

*note Python/C API Reference Manual: 1fa6.

     The details of Python’s C interface are given in this manual.  A
     great deal of necessary information can be found here.

* Menu:

* Very High Level Embedding::
* Beyond Very High Level Embedding; An overview: Beyond Very High Level Embedding An overview.
* Pure Embedding::
* Extending Embedded Python::
* Embedding Python in C++::
* Compiling and Linking under Unix-like systems::


File: python.info,  Node: Very High Level Embedding,  Next: Beyond Very High Level Embedding An overview,  Up: Embedding Python in Another Application

6.3.1.1 Very High Level Embedding
.................................

The simplest form of embedding Python is the use of the very high level
interface.  This interface is intended to execute a Python script
without needing to interact with the application directly.  This can for
example be used to perform some operation on a file.

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>

     int
     main(int argc, char *argv[])
     {
         PyStatus status;
         PyConfig config;
         PyConfig_InitPythonConfig(&config);

         /* optional but recommended */
         status = PyConfig_SetBytesString(&config, &config.program_name, argv[0]);
         if (PyStatus_Exception(status)) {
             goto exception;
         }

         status = Py_InitializeFromConfig(&config);
         if (PyStatus_Exception(status)) {
             goto exception;
         }
         PyConfig_Clear(&config);

         PyRun_SimpleString("from time import time,ctime\n"
                            "print('Today is', ctime(time()))\n");
         if (Py_FinalizeEx() < 0) {
             exit(120);
         }
         return 0;

       exception:
          PyConfig_Clear(&config);
          Py_ExitStatusException(status);
     }

     Nota: ‘#define PY_SSIZE_T_CLEAN’ was used to indicate that
     ‘Py_ssize_t’ should be used in some APIs instead of ‘int’.  It is
     not necessary since Python 3.13, but we keep it here for backward
     compatibility.  See *note Strings and buffers: 62c. for a
     description of this macro.

Setting *note PyConfig.program_name: 3f2. should be called before *note
Py_InitializeFromConfig(): 3f6. to inform the interpreter about paths to
Python run-time libraries.  Next, the Python interpreter is initialized
with *note Py_Initialize(): 460, followed by the execution of a
hard-coded Python script that prints the date and time.  Afterwards, the
*note Py_FinalizeEx(): f13. call shuts the interpreter down, followed by
the end of the program.  In a real program, you may want to get the
Python script from another source, perhaps a text-editor routine, a
file, or a database.  Getting the Python code from a file can better be
done by using the *note PyRun_SimpleFile(): 4ef5. function, which saves
you the trouble of allocating memory space and loading the file
contents.


File: python.info,  Node: Beyond Very High Level Embedding An overview,  Next: Pure Embedding,  Prev: Very High Level Embedding,  Up: Embedding Python in Another Application

6.3.1.2 Beyond Very High Level Embedding: An overview
.....................................................

The high level interface gives you the ability to execute arbitrary
pieces of Python code from your application, but exchanging data values
is quite cumbersome to say the least.  If you want that, you should use
lower level calls.  At the cost of having to write more C code, you can
achieve almost anything.

It should be noted that extending Python and embedding Python is quite
the same activity, despite the different intent.  Most topics discussed
in the previous chapters are still valid.  To show this, consider what
the extension code from Python to C really does:

  1. Convert data values from Python to C,

  2. Perform a function call to a C routine using the converted values,
     and

  3. Convert the data values from the call from C to Python.

When embedding Python, the interface code does:

  1. Convert data values from C to Python,

  2. Perform a function call to a Python interface routine using the
     converted values, and

  3. Convert the data values from the call from Python to C.

As you can see, the data conversion steps are simply swapped to
accommodate the different direction of the cross-language transfer.  The
only difference is the routine that you call between both data
conversions.  When extending, you call a C routine, when embedding, you
call a Python routine.

This chapter will not discuss how to convert data from Python to C and
vice versa.  Also, proper use of references and dealing with errors is
assumed to be understood.  Since these aspects do not differ from
extending the interpreter, you can refer to earlier chapters for the
required information.


File: python.info,  Node: Pure Embedding,  Next: Extending Embedded Python,  Prev: Beyond Very High Level Embedding An overview,  Up: Embedding Python in Another Application

6.3.1.3 Pure Embedding
......................

The first program aims to execute a function in a Python script.  Like
in the section about the very high level interface, the Python
interpreter does not directly interact with the application (but that
will change in the next section).

The code to run a function defined in a Python script is:

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>

     int
     main(int argc, char *argv[])
     {
         PyObject *pName, *pModule, *pFunc;
         PyObject *pArgs, *pValue;
         int i;

         if (argc < 3) {
             fprintf(stderr,"Usage: call pythonfile funcname [args]\n");
             return 1;
         }

         Py_Initialize();
         pName = PyUnicode_DecodeFSDefault(argv[1]);
         /* Error checking of pName left out */

         pModule = PyImport_Import(pName);
         Py_DECREF(pName);

         if (pModule != NULL) {
             pFunc = PyObject_GetAttrString(pModule, argv[2]);
             /* pFunc is a new reference */

             if (pFunc && PyCallable_Check(pFunc)) {
                 pArgs = PyTuple_New(argc - 3);
                 for (i = 0; i < argc - 3; ++i) {
                     pValue = PyLong_FromLong(atoi(argv[i + 3]));
                     if (!pValue) {
                         Py_DECREF(pArgs);
                         Py_DECREF(pModule);
                         fprintf(stderr, "Cannot convert argument\n");
                         return 1;
                     }
                     /* pValue reference stolen here: */
                     PyTuple_SetItem(pArgs, i, pValue);
                 }
                 pValue = PyObject_CallObject(pFunc, pArgs);
                 Py_DECREF(pArgs);
                 if (pValue != NULL) {
                     printf("Result of call: %ld\n", PyLong_AsLong(pValue));
                     Py_DECREF(pValue);
                 }
                 else {
                     Py_DECREF(pFunc);
                     Py_DECREF(pModule);
                     PyErr_Print();
                     fprintf(stderr,"Call failed\n");
                     return 1;
                 }
             }
             else {
                 if (PyErr_Occurred())
                     PyErr_Print();
                 fprintf(stderr, "Cannot find function \"%s\"\n", argv[2]);
             }
             Py_XDECREF(pFunc);
             Py_DECREF(pModule);
         }
         else {
             PyErr_Print();
             fprintf(stderr, "Failed to load \"%s\"\n", argv[1]);
             return 1;
         }
         if (Py_FinalizeEx() < 0) {
             return 120;
         }
         return 0;
     }

This code loads a Python script using ‘argv[1]’, and calls the function
named in ‘argv[2]’.  Its integer arguments are the other values of the
‘argv’ array.  If you *note compile and link: 4efc. this program (let’s
call the finished executable ‘call’), and use it to execute a Python
script, such as:

     def multiply(a,b):
         print("Will compute", a, "times", b)
         c = 0
         for i in range(0, a):
             c = c + b
         return c

then the result should be:

     $ call multiply multiply 3 2
     Will compute 3 times 2
     Result of call: 6

Although the program is quite large for its functionality, most of the
code is for data conversion between Python and C, and for error
reporting.  The interesting part with respect to embedding Python starts
with

     Py_Initialize();
     pName = PyUnicode_DecodeFSDefault(argv[1]);
     /* Error checking of pName left out */
     pModule = PyImport_Import(pName);

After initializing the interpreter, the script is loaded using *note
PyImport_Import(): 1603.  This routine needs a Python string as its
argument, which is constructed using the *note
PyUnicode_DecodeFSDefault(): 1a70. data conversion routine.

     pFunc = PyObject_GetAttrString(pModule, argv[2]);
     /* pFunc is a new reference */

     if (pFunc && PyCallable_Check(pFunc)) {
         ...
     }
     Py_XDECREF(pFunc);

Once the script is loaded, the name we’re looking for is retrieved using
*note PyObject_GetAttrString(): 5ef.  If the name exists, and the object
returned is callable, you can safely assume that it is a function.  The
program then proceeds by constructing a tuple of arguments as normal.
The call to the Python function is then made with:

     pValue = PyObject_CallObject(pFunc, pArgs);

Upon return of the function, ‘pValue’ is either ‘NULL’ or it contains a
reference to the return value of the function.  Be sure to release the
reference after examining the value.


File: python.info,  Node: Extending Embedded Python,  Next: Embedding Python in C++,  Prev: Pure Embedding,  Up: Embedding Python in Another Application

6.3.1.4 Extending Embedded Python
.................................

Until now, the embedded Python interpreter had no access to
functionality from the application itself.  The Python API allows this
by extending the embedded interpreter.  That is, the embedded
interpreter gets extended with routines provided by the application.
While it sounds complex, it is not so bad.  Simply forget for a while
that the application starts the Python interpreter.  Instead, consider
the application to be a set of subroutines, and write some glue code
that gives Python access to those routines, just like you would write a
normal Python extension.  For example:

     static int numargs=0;

     /* Return the number of arguments of the application command line */
     static PyObject*
     emb_numargs(PyObject *self, PyObject *args)
     {
         if(!PyArg_ParseTuple(args, ":numargs"))
             return NULL;
         return PyLong_FromLong(numargs);
     }

     static PyMethodDef emb_module_methods[] = {
         {"numargs", emb_numargs, METH_VARARGS,
          "Return the number of arguments received by the process."},
         {NULL, NULL, 0, NULL}
     };

     static struct PyModuleDef emb_module = {
         .m_base = PyModuleDef_HEAD_INIT,
         .m_name = "emb",
         .m_size = 0,
         .m_methods = emb_module_methods,
     };

     static PyObject*
     PyInit_emb(void)
     {
         return PyModuleDef_Init(&emb_module);
     }

Insert the above code just above the ‘main()’ function.  Also, insert
the following two statements before the call to *note Py_Initialize():
460.:

     numargs = argc;
     PyImport_AppendInittab("emb", &PyInit_emb);

These two lines initialize the ‘numargs’ variable, and make the
‘emb.numargs()’ function accessible to the embedded Python interpreter.
With these extensions, the Python script can do things like

     import emb
     print("Number of arguments", emb.numargs())

In a real application, the methods will expose an API of the application
to Python.


File: python.info,  Node: Embedding Python in C++,  Next: Compiling and Linking under Unix-like systems,  Prev: Extending Embedded Python,  Up: Embedding Python in Another Application

6.3.1.5 Embedding Python in C++
...............................

It is also possible to embed Python in a C++ program; precisely how this
is done will depend on the details of the C++ system used; in general
you will need to write the main program in C++, and use the C++ compiler
to compile and link your program.  There is no need to recompile Python
itself using C++.


File: python.info,  Node: Compiling and Linking under Unix-like systems,  Prev: Embedding Python in C++,  Up: Embedding Python in Another Application

6.3.1.6 Compiling and Linking under Unix-like systems
.....................................................

It is not necessarily trivial to find the right flags to pass to your
compiler (and linker) in order to embed the Python interpreter into your
application, particularly because Python needs to load library modules
implemented as C dynamic extensions (‘.so’ files) linked against it.

To find out the required compiler and linker flags, you can execute the
‘python`X.Y'-config’ script which is generated as part of the
installation process (a ‘python3-config’ script may also be available).
This script has several options, of which the following will be directly
useful to you:

   * ‘pythonX.Y-config --cflags’ will give you the recommended flags
     when compiling:

          $ /opt/bin/python3.11-config --cflags
          -I/opt/include/python3.11 -I/opt/include/python3.11 -Wsign-compare  -DNDEBUG -g -fwrapv -O3 -Wall

   * ‘pythonX.Y-config --ldflags --embed’ will give you the recommended
     flags when linking:

          $ /opt/bin/python3.11-config --ldflags --embed
          -L/opt/lib/python3.11/config-3.11-x86_64-linux-gnu -L/opt/lib -lpython3.11 -lpthread -ldl  -lutil -lm

     Nota: To avoid confusion between several Python installations (and
     especially between the system Python and your own compiled Python),
     it is recommended that you use the absolute path to
     ‘python`X.Y'-config’, as in the above example.

If this procedure doesn’t work for you (it is not guaranteed to work for
all Unix-like platforms; however, we welcome *note bug reports: 4f02.)
you will have to read your system’s documentation about dynamic linking
and/or examine Python’s ‘Makefile’ (use *note
sysconfig.get_makefile_filename(): 495b. to find its location) and
compilation options.  In this case, the *note sysconfig: e1. module is a
useful tool to programmatically extract the configuration values that
you will want to combine together.  For example:

     >>> import sysconfig
     >>> sysconfig.get_config_var('LIBS')
     '-lpthread -ldl  -lutil'
     >>> sysconfig.get_config_var('LINKFORSHARED')
     '-Xlinker -export-dynamic'


File: python.info,  Node: Python/C API Reference Manual,  Next: Installing Python Modules,  Prev: Extending and Embedding the Python Interpreter,  Up: Top

7 Python/C API Reference Manual
*******************************

This manual documents the API used by C and C++ programmers who want to
write extension modules or embed Python.  It is a companion to *note
Extending and Embedding the Python Interpreter: 1fa5, which describes
the general principles of extension writing but does not document the
API functions in detail.

* Menu:

* Introduction: Introduction<13>.
* C API Stability::
* The Very High Level Layer::
* Reference Counting::
* Exception Handling::
* Defining extension modules::
* Utilities: Utilities<2>.
* Abstract Objects Layer::
* Concrete Objects Layer::
* Initialization, Finalization, and Threads: Initialization Finalization and Threads.
* Python Initialization Configuration::
* Memory Management::
* Object Implementation Support::
* API and ABI Versioning::
* Monitoring C API::
* Generating Execution Events::


File: python.info,  Node: Introduction<13>,  Next: C API Stability,  Up: Python/C API Reference Manual

7.1 Introduction
================

The Application Programmer’s Interface to Python gives C and C++
programmers access to the Python interpreter at a variety of levels.
The API is equally usable from C++, but for brevity it is generally
referred to as the Python/C API. There are two fundamentally different
reasons for using the Python/C API. The first reason is to write
'extension modules' for specific purposes; these are C modules that
extend the Python interpreter.  This is probably the most common use.
The second reason is to use Python as a component in a larger
application; this technique is generally referred to as 'embedding'
Python in an application.

Writing an extension module is a relatively well-understood process,
where a «cookbook» approach works well.  There are several tools that
automate the process to some extent.  While people have embedded Python
in other applications since its early existence, the process of
embedding Python is less straightforward than writing an extension.

Many API functions are useful independent of whether you’re embedding or
extending Python; moreover, most applications that embed Python will
need to provide a custom extension as well, so it’s probably a good idea
to become familiar with writing an extension before attempting to embed
Python in a real application.

* Menu:

* Language version compatibility::
* Coding standards::
* Include Files::
* Useful macros::
* Objects, Types and Reference Counts: Objects Types and Reference Counts.
* Exceptions: Exceptions<23>.
* Embedding Python: Embedding Python<2>.
* Debugging Builds::
* Recommended third party tools: Recommended third party tools<2>.


File: python.info,  Node: Language version compatibility,  Next: Coding standards,  Up: Introduction<13>

7.1.1 Language version compatibility
------------------------------------

Python’s C API is compatible with C11 and C++11 versions of C and C++.

This is a lower limit: the C API does not require features from later
C/C++ versions.  You do 'not' need to enable your compiler’s «c11 mode».


File: python.info,  Node: Coding standards,  Next: Include Files,  Prev: Language version compatibility,  Up: Introduction<13>

7.1.2 Coding standards
----------------------

If you’re writing C code for inclusion in CPython, you 'must' follow the
guidelines and standards defined in PEP 7(1).  These guidelines apply
regardless of the version of Python you are contributing to.  Following
these conventions is not necessary for your own third party extension
modules, unless you eventually expect to contribute them to Python.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0007/


File: python.info,  Node: Include Files,  Next: Useful macros,  Prev: Coding standards,  Up: Introduction<13>

7.1.3 Include Files
-------------------

All function, type and macro definitions needed to use the Python/C API
are included in your code by the following line:

     #define PY_SSIZE_T_CLEAN
     #include <Python.h>

This implies inclusion of the following standard headers: ‘<stdio.h>’,
‘<string.h>’, ‘<errno.h>’, ‘<limits.h>’, ‘<assert.h>’ and ‘<stdlib.h>’
(if available).

     Nota: Since Python may define some pre-processor definitions which
     affect the standard headers on some systems, you 'must' include
     ‘Python.h’ before any standard headers are included.

     It is recommended to always define ‘PY_SSIZE_T_CLEAN’ before
     including ‘Python.h’.  See *note Parsing arguments and building
     values: 3d5. for a description of this macro.

All user visible names defined by Python.h (except those defined by the
included standard headers) have one of the prefixes ‘Py’ or ‘_Py’.
Names beginning with ‘_Py’ are for internal use by the Python
implementation and should not be used by extension writers.  Structure
member names do not have a reserved prefix.

     Nota: User code should never define names that begin with ‘Py’ or
     ‘_Py’.  This confuses the reader, and jeopardizes the portability
     of the user code to future Python versions, which may define
     additional names beginning with one of these prefixes.

The header files are typically installed with Python.  On Unix, these
are located in the directories ‘`prefix'/include/pythonversion/’ and
‘`exec_prefix'/include/pythonversion/’, where *note prefix: 2138. and
*note exec_prefix: 2139. are defined by the corresponding parameters to
Python’s ‘configure’ script and 'version' is ‘'%d.%d' %
sys.version_info[:2]’.  On Windows, the headers are installed in
‘`prefix'/include’, where ‘prefix’ is the installation directory
specified to the installer.

To include the headers, place both directories (if different) on your
compiler’s search path for includes.  Do 'not' place the parent
directories on the search path and then use ‘#include
<pythonX.Y/Python.h>’; this will break on multi-platform builds since
the platform independent headers under *note prefix: 2138. include the
platform specific headers from *note exec_prefix: 2139.

C++ users should note that although the API is defined entirely using C,
the header files properly declare the entry points to be ‘extern "C"’.
As a result, there is no need to do anything special to use the API from
C++.


File: python.info,  Node: Useful macros,  Next: Objects Types and Reference Counts,  Prev: Include Files,  Up: Introduction<13>

7.1.4 Useful macros
-------------------

Several useful macros are defined in the Python header files.  Many are
defined closer to where they are useful (for example, *note
Py_RETURN_NONE: 167a, *note PyMODINIT_FUNC: 16da.).  Others of a more
general utility are defined here.  This is not necessarily a complete
listing.

 -- C Macro: Py_ABS (x)

     Return the absolute value of ‘x’.

     If the result cannot be represented (for example, if ‘x’ has
     ‘INT_MIN’ value for int type), the behavior is undefined.

     Added in version 3.3.

 -- C Macro: Py_ALWAYS_INLINE

     Ask the compiler to always inline a static inline function.  The
     compiler can ignore it and decide to not inline the function.

     It can be used to inline performance critical static inline
     functions when building Python in debug mode with function inlining
     disabled.  For example, MSC disables function inlining when
     building in debug mode.

     Marking blindly a static inline function with Py_ALWAYS_INLINE can
     result in worse performances (due to increased code size for
     example).  The compiler is usually smarter than the developer for
     the cost/benefit analysis.

     If Python is *note built in debug mode: 50a. (if the *note
     Py_DEBUG: 181c. macro is defined), the *note Py_ALWAYS_INLINE:
     1c53. macro does nothing.

     It must be specified before the function return type.  Usage:

          static inline Py_ALWAYS_INLINE int random(void) { return 4; }

     Added in version 3.11.

 -- C Macro: Py_CHARMASK (c)

     Argument must be a character or an integer in the range [-128, 127]
     or [0, 255].  This macro returns ‘c’ cast to an ‘unsigned char’.

 -- C Macro: Py_DEPRECATED (version)

     Use this for deprecated declarations.  The macro must be placed
     before the symbol name.

     Example:

          Py_DEPRECATED(3.8) PyAPI_FUNC(int) Py_OldFunction(void);

     Cambiato nella versione 3.8: MSVC support was added.

 -- C Macro: Py_GETENV (s)

     Like ‘getenv(s)’, but returns ‘NULL’ if *note -E: b58. was passed
     on the command line (see *note PyConfig.use_environment: 40b.).

 -- C Macro: Py_LOCAL (type)

     Declare a function returning the specified 'type' using a
     fast-calling qualifier for functions that are local to the current
     file.  Semantically, this is equivalent to ‘static type’.

 -- C Macro: Py_LOCAL_INLINE (type)

     Equivalent to *note Py_LOCAL: 1651. but additionally requests the
     function be inlined.

 -- C Macro: Py_LOCAL_SYMBOL

     Macro used to declare a symbol as local to the shared library
     (hidden).  On supported platforms, it ensures the symbol is not
     exported.

     On compatible versions of GCC/Clang, it expands to
     ‘__attribute__((visibility("hidden")))’.

 -- C Macro: Py_MAX (x, y)

     Return the maximum value between ‘x’ and ‘y’.

     Added in version 3.3.

 -- C Macro: Py_MEMBER_SIZE (type, member)

     Return the size of a structure (‘type’) ‘member’ in bytes.

     Added in version 3.6.

 -- C Macro: Py_MEMCPY (dest, src, n)

     This is a *note soft deprecated: 23d. alias to ‘memcpy()’.  Use
     ‘memcpy()’ directly instead.

     Deprecato dalla versione 3.14: The macro is *note soft deprecated:
     23d.

 -- C Macro: Py_MIN (x, y)

     Return the minimum value between ‘x’ and ‘y’.

     Added in version 3.3.

 -- C Macro: Py_NO_INLINE

     Disable inlining on a function.  For example, it reduces the C
     stack consumption: useful on LTO+PGO builds which heavily inline
     code (see bpo-33720(1)).

     Usage:

          Py_NO_INLINE static int random(void) { return 4; }

     Added in version 3.11.

 -- C Macro: Py_STRINGIFY (x)

     Convert ‘x’ to a C string.  E.g.  ‘Py_STRINGIFY(123)’ returns
     ‘"123"’.

     Added in version 3.4.

 -- C Macro: Py_UNREACHABLE ()

     Use this when you have a code path that cannot be reached by
     design.  For example, in the ‘default:’ clause in a ‘switch’
     statement for which all possible values are covered in ‘case’
     statements.  Use this in places where you might be tempted to put
     an ‘assert(0)’ or ‘abort()’ call.

     In release mode, the macro helps the compiler to optimize the code,
     and avoids a warning about unreachable code.  For example, the
     macro is implemented with ‘__builtin_unreachable()’ on GCC in
     release mode.

     A use for ‘Py_UNREACHABLE()’ is following a call a function that
     never returns but that is not declared ‘_Py_NO_RETURN’.

     If a code path is very unlikely code but can be reached under
     exceptional case, this macro must not be used.  For example, under
     low memory condition or if a system call returns a value out of the
     expected range.  In this case, it’s better to report the error to
     the caller.  If the error cannot be reported to caller, *note
     Py_FatalError(): b7c. can be used.

     Added in version 3.7.

 -- C Macro: Py_UNUSED (arg)

     Use this for unused arguments in a function definition to silence
     compiler warnings.  Example: ‘int func(int a, int Py_UNUSED(b)) {
     return a; }’.

     Added in version 3.4.

 -- C Macro: Py_BUILD_ASSERT (cond)

     Asserts a compile-time condition 'cond', as a statement.  The build
     will fail if the condition is false or cannot be evaluated at
     compile time.

     For example:

          Py_BUILD_ASSERT(sizeof(PyTime_t) == sizeof(int64_t));

     Added in version 3.3.

 -- C Macro: Py_BUILD_ASSERT_EXPR (cond)

     Asserts a compile-time condition 'cond', as an expression that
     evaluates to ‘0’.  The build will fail if the condition is false or
     cannot be evaluated at compile time.

     For example:

          #define foo_to_char(foo) \
              ((char *)(foo) + Py_BUILD_ASSERT_EXPR(offsetof(struct foo, string) == 0))

     Added in version 3.3.

 -- C Macro: PyDoc_STRVAR (name, str)

     Creates a variable with name 'name' that can be used in docstrings.
     If Python is built without docstrings, the value will be empty.

     Use *note PyDoc_STRVAR: 1d43. for docstrings to support building
     Python without docstrings, as specified in PEP 7(2).

     Example:

          PyDoc_STRVAR(pop_doc, "Remove and return the rightmost element.");

          static PyMethodDef deque_methods[] = {
              // ...
              {"pop", (PyCFunction)deque_pop, METH_NOARGS, pop_doc},
              // ...
          }

 -- C Macro: PyDoc_STR (str)

     Creates a docstring for the given input string or an empty string
     if docstrings are disabled.

     Use *note PyDoc_STR: 1b7e. in specifying docstrings to support
     building Python without docstrings, as specified in PEP 7(3).

     Example:

          static PyMethodDef pysqlite_row_methods[] = {
              {"keys", (PyCFunction)pysqlite_row_keys, METH_NOARGS,
                  PyDoc_STR("Returns the keys of the row.")},
              {NULL, NULL}
          };

 -- C Macro: PyDoc_VAR (name)

     Declares a static character array variable with the given name
     'name'.

     For example:

          PyDoc_VAR(python_doc) = PyDoc_STR("A genus of constricting snakes in the Pythonidae family native "
                                            "to the tropics and subtropics of the Eastern Hemisphere.");

 -- C Macro: Py_ARRAY_LENGTH (array)

     Compute the length of a statically allocated C array at compile
     time.

     The 'array' argument must be a C array with a size known at compile
     time.  Passing an array with an unknown size, such as a
     heap-allocated array, will result in a compilation error on some
     compilers, or otherwise produce incorrect results.

     This is roughly equivalent to:

          sizeof(array) / sizeof((array)[0])

 -- C Macro: Py_EXPORTED_SYMBOL

     Macro used to declare a symbol (function or data) as exported.  On
     Windows, this expands to ‘__declspec(dllexport)’.  On compatible
     versions of GCC/Clang, it expands to
     ‘__attribute__((visibility("default")))’.  This macro is for
     defining the C API itself; extension modules should not use it.

 -- C Macro: Py_IMPORTED_SYMBOL

     Macro used to declare a symbol as imported.  On Windows, this
     expands to ‘__declspec(dllimport)’.  This macro is for defining the
     C API itself; extension modules should not use it.

 -- C Macro: PyAPI_FUNC (type)

     Macro used by CPython to declare a function as part of the C API.
     Its expansion depends on the platform and build configuration.
     This macro is intended for defining CPython’s C API itself;
     extension modules should not use it for their own symbols.

 -- C Macro: PyAPI_DATA (type)

     Macro used by CPython to declare a public global variable as part
     of the C API. Its expansion depends on the platform and build
     configuration.  This macro is intended for defining CPython’s C API
     itself; extension modules should not use it for their own symbols.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=33720

   (2) https://peps.python.org/pep-0007/

   (3) https://peps.python.org/pep-0007/


File: python.info,  Node: Objects Types and Reference Counts,  Next: Exceptions<23>,  Prev: Useful macros,  Up: Introduction<13>

7.1.5 Objects, Types and Reference Counts
-----------------------------------------

Most Python/C API functions have one or more arguments as well as a
return value of type *note PyObject: 5df.*.  This type is a pointer to
an opaque data type representing an arbitrary Python object.  Since all
Python object types are treated the same way by the Python language in
most situations (e.g., assignments, scope rules, and argument passing),
it is only fitting that they should be represented by a single C type.
Almost all Python objects live on the heap: you never declare an
automatic or static variable of type *note PyObject: 5df, only pointer
variables of type *note PyObject: 5df.* can be declared.  The sole
exception are the type objects; since these must never be deallocated,
they are typically static *note PyTypeObject: c9e. objects.

All Python objects (even Python integers) have a 'type' and a 'reference
count'.  An object’s type determines what kind of object it is (e.g., an
integer, a list, or a user-defined function; there are many more as
explained in *note The standard type hierarchy: 2318.).  For each of the
well-known types there is a macro to check whether an object is of that
type; for instance, ‘PyList_Check(a)’ is true if (and only if) the
object pointed to by 'a' is a Python list.

* Menu:

* Reference Counts: Reference Counts<2>.
* Types: Types<2>.


File: python.info,  Node: Reference Counts<2>,  Next: Types<2>,  Up: Objects Types and Reference Counts

7.1.5.1 Reference Counts
........................

The reference count is important because today’s computers have a finite
(and often severely limited) memory size; it counts how many different
places there are that have a *note strong reference: 5e2. to an object.
Such a place could be another object, or a global (or static) C
variable, or a local variable in some C function.  When the last *note
strong reference: 5e2. to an object is released (i.e.  its reference
count becomes zero), the object is deallocated.  If it contains
references to other objects, those references are released.  Those other
objects may be deallocated in turn, if there are no more references to
them, and so on.  (There’s an obvious problem with objects that
reference each other here; for now, the solution is «don’t do that.»)

Reference counts are always manipulated explicitly.  The normal way is
to use the macro *note Py_INCREF(): 790. to take a new reference to an
object (i.e.  increment its reference count by one), and *note
Py_DECREF(): 791. to release that reference (i.e.  decrement the
reference count by one).  The *note Py_DECREF(): 791. macro is
considerably more complex than the incref one, since it must check
whether the reference count becomes zero and then cause the object’s
deallocator to be called.  The deallocator is a function pointer
contained in the object’s type structure.  The type-specific deallocator
takes care of releasing references for other objects contained in the
object if this is a compound object type, such as a list, as well as
performing any additional finalization that’s needed.  There’s no chance
that the reference count can overflow; at least as many bits are used to
hold the reference count as there are distinct memory locations in
virtual memory (assuming ‘sizeof(Py_ssize_t) >= sizeof(void*)’).  Thus,
the reference count increment is a simple operation.

It is not necessary to hold a *note strong reference: 5e2. (i.e.
increment the reference count) for every local variable that contains a
pointer to an object.  In theory, the object’s reference count goes up
by one when the variable is made to point to it and it goes down by one
when the variable goes out of scope.  However, these two cancel each
other out, so at the end the reference count hasn’t changed.  The only
real reason to use the reference count is to prevent the object from
being deallocated as long as our variable is pointing to it.  If we know
that there is at least one other reference to the object that lives at
least as long as our variable, there is no need to take a new *note
strong reference: 5e2. (i.e.  increment the reference count)
temporarily.  An important situation where this arises is in objects
that are passed as arguments to C functions in an extension module that
are called from Python; the call mechanism guarantees to hold a
reference to every argument for the duration of the call.

However, a common pitfall is to extract an object from a list and hold
on to it for a while without taking a new reference.  Some other
operation might conceivably remove the object from the list, releasing
that reference, and possibly deallocating it.  The real danger is that
innocent-looking operations may invoke arbitrary Python code which could
do this; there is a code path which allows control to flow back to the
user from a *note Py_DECREF(): 791, so almost any operation is
potentially dangerous.

A safe approach is to always use the generic operations (functions whose
name begins with ‘PyObject_’, ‘PyNumber_’, ‘PySequence_’ or
‘PyMapping_’).  These operations always create a new *note strong
reference: 5e2. (i.e.  increment the reference count) of the object they
return.  This leaves the caller with the responsibility to call *note
Py_DECREF(): 791. when they are done with the result; this soon becomes
second nature.

* Menu:

* Reference Count Details::


File: python.info,  Node: Reference Count Details,  Up: Reference Counts<2>

7.1.5.2 Reference Count Details
...............................

The reference count behavior of functions in the Python/C API is best
explained in terms of 'ownership of references'.  Ownership pertains to
references, never to objects (objects are not owned: they are always
shared).  «Owning a reference» means being responsible for calling
Py_DECREF on it when the reference is no longer needed.  Ownership can
also be transferred, meaning that the code that receives ownership of
the reference then becomes responsible for eventually releasing it by
calling *note Py_DECREF(): 791. or *note Py_XDECREF(): 993. when it’s no
longer needed—or passing on this responsibility (usually to its caller).
When a function passes ownership of a reference on to its caller, the
caller is said to receive a 'new' reference.  When no ownership is
transferred, the caller is said to 'borrow' the reference.  Nothing
needs to be done for a *note borrowed reference: 3d7.

Conversely, when a calling function passes in a reference to an object,
there are two possibilities: the function 'steals' a reference to the
object, or it does not.  'Stealing a reference' means that when you pass
a reference to a function, that function assumes that it now owns that
reference, and you are not responsible for it any longer.

Few functions steal references; the two notable exceptions are *note
PyList_SetItem(): 18a2. and *note PyTuple_SetItem(): 4ea1, which steal a
reference to the item (but not to the tuple or list into which the item
is put!).  These functions were designed to steal a reference because of
a common idiom for populating a tuple or list with newly created
objects; for example, the code to create the tuple ‘(1, 2, "three")’
could look like this (forgetting about error handling for the moment; a
better way to code this is shown below):

     PyObject *t;

     t = PyTuple_New(3);
     PyTuple_SetItem(t, 0, PyLong_FromLong(1L));
     PyTuple_SetItem(t, 1, PyLong_FromLong(2L));
     PyTuple_SetItem(t, 2, PyUnicode_FromString("three"));

Here, *note PyLong_FromLong(): 1bb8. returns a new reference which is
immediately stolen by *note PyTuple_SetItem(): 4ea1.  When you want to
keep using an object although the reference to it will be stolen, use
*note Py_INCREF(): 790. to grab another reference before calling the
reference-stealing function.

Incidentally, *note PyTuple_SetItem(): 4ea1. is the 'only' way to set
tuple items; *note PySequence_SetItem(): 1e1d. and *note
PyObject_SetItem(): 4f20. refuse to do this since tuples are an
immutable data type.  You should only use *note PyTuple_SetItem(): 4ea1.
for tuples that you are creating yourself.

Equivalent code for populating a list can be written using *note
PyList_New(): 4f21. and *note PyList_SetItem(): 18a2.

However, in practice, you will rarely use these ways of creating and
populating a tuple or list.  There’s a generic function, *note
Py_BuildValue(): 3c2, that can create most common objects from C values,
directed by a 'format string'.  For example, the above two blocks of
code could be replaced by the following (which also takes care of the
error checking):

     PyObject *tuple, *list;

     tuple = Py_BuildValue("(iis)", 1, 2, "three");
     list = Py_BuildValue("[iis]", 1, 2, "three");

It is much more common to use *note PyObject_SetItem(): 4f20. and
friends with items whose references you are only borrowing, like
arguments that were passed in to the function you are writing.  In that
case, their behaviour regarding references is much saner, since you
don’t have to take a new reference just so you can give that reference
away («have it be stolen»).  For example, this function sets all items
of a list (actually, any mutable sequence) to a given item:

     int
     set_all(PyObject *target, PyObject *item)
     {
         Py_ssize_t i, n;

         n = PyObject_Length(target);
         if (n < 0)
             return -1;
         for (i = 0; i < n; i++) {
             PyObject *index = PyLong_FromSsize_t(i);
             if (!index)
                 return -1;
             if (PyObject_SetItem(target, index, item) < 0) {
                 Py_DECREF(index);
                 return -1;
             }
             Py_DECREF(index);
         }
         return 0;
     }

The situation is slightly different for function return values.  While
passing a reference to most functions does not change your ownership
responsibilities for that reference, many functions that return a
reference to an object give you ownership of the reference.  The reason
is simple: in many cases, the returned object is created on the fly, and
the reference you get is the only reference to the object.  Therefore,
the generic functions that return object references, like *note
PyObject_GetItem(): 5ea. and *note PySequence_GetItem(): 1e1c, always
return a new reference (the caller becomes the owner of the reference).

It is important to realize that whether you own a reference returned by
a function depends on which function you call only — 'the plumage' (the
type of the object passed as an argument to the function) 'doesn’t enter
into it!'  Thus, if you extract an item from a list using *note
PyList_GetItem(): 5ff, you don’t own the reference — but if you obtain
the same item from the same list using *note PySequence_GetItem(): 1e1c.
(which happens to take exactly the same arguments), you do own a
reference to the returned object.

Here is an example of how you could write a function that computes the
sum of the items in a list of integers; once using *note
PyList_GetItem(): 5ff, and once using *note PySequence_GetItem(): 1e1c.

     long
     sum_list(PyObject *list)
     {
         Py_ssize_t i, n;
         long total = 0, value;
         PyObject *item;

         n = PyList_Size(list);
         if (n < 0)
             return -1; /* Not a list */
         for (i = 0; i < n; i++) {
             item = PyList_GetItem(list, i); /* Can't fail */
             if (!PyLong_Check(item)) continue; /* Skip non-integers */
             value = PyLong_AsLong(item);
             if (value == -1 && PyErr_Occurred())
                 /* Integer too big to fit in a C long, bail out */
                 return -1;
             total += value;
         }
         return total;
     }

     long
     sum_sequence(PyObject *sequence)
     {
         Py_ssize_t i, n;
         long total = 0, value;
         PyObject *item;
         n = PySequence_Length(sequence);
         if (n < 0)
             return -1; /* Has no length */
         for (i = 0; i < n; i++) {
             item = PySequence_GetItem(sequence, i);
             if (item == NULL)
                 return -1; /* Not a sequence, or other failure */
             if (PyLong_Check(item)) {
                 value = PyLong_AsLong(item);
                 Py_DECREF(item);
                 if (value == -1 && PyErr_Occurred())
                     /* Integer too big to fit in a C long, bail out */
                     return -1;
                 total += value;
             }
             else {
                 Py_DECREF(item); /* Discard reference ownership */
             }
         }
         return total;
     }


File: python.info,  Node: Types<2>,  Prev: Reference Counts<2>,  Up: Objects Types and Reference Counts

7.1.5.3 Types
.............

There are few other data types that play a significant role in the
Python/C API; most are simple C types such as int, long, double and
char*.  A few structure types are used to describe static tables used to
list the functions exported by a module or the data attributes of a new
object type, and another is used to describe the value of a complex
number.  These will be discussed together with the functions that use
them.

 -- C Tipo: type Py_ssize_t
     ' Parte del *note ABI Stabile: 776.'  A signed integral type such
     that ‘sizeof(Py_ssize_t) == sizeof(size_t)’.  C99 doesn’t define
     such a thing directly (size_t is an unsigned integral type).  See
     PEP 353(1) for details.  ‘PY_SSIZE_T_MAX’ is the largest positive
     value of type *note Py_ssize_t: c57.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0353/


File: python.info,  Node: Exceptions<23>,  Next: Embedding Python<2>,  Prev: Objects Types and Reference Counts,  Up: Introduction<13>

7.1.6 Exceptions
----------------

The Python programmer only needs to deal with exceptions if specific
error handling is required; unhandled exceptions are automatically
propagated to the caller, then to the caller’s caller, and so on, until
they reach the top-level interpreter, where they are reported to the
user accompanied by a stack traceback.

For C programmers, however, error checking always has to be explicit.
All functions in the Python/C API can raise exceptions, unless an
explicit claim is made otherwise in a function’s documentation.  In
general, when a function encounters an error, it sets an exception,
discards any object references that it owns, and returns an error
indicator.  If not documented otherwise, this indicator is either ‘NULL’
or ‘-1’, depending on the function’s return type.  A few functions
return a Boolean true/false result, with false indicating an error.
Very few functions return no explicit error indicator or have an
ambiguous return value, and require explicit testing for errors with
*note PyErr_Occurred(): 1c97.  These exceptions are always explicitly
documented.

Exception state is maintained in per-thread storage (this is equivalent
to using global storage in an unthreaded application).  A thread can be
in one of two states: an exception has occurred, or not.  The function
*note PyErr_Occurred(): 1c97. can be used to check for this: it returns
a borrowed reference to the exception type object when an exception has
occurred, and ‘NULL’ otherwise.  There are a number of functions to set
the exception state: *note PyErr_SetString(): 79d. is the most common
(though not the most general) function to set the exception state, and
*note PyErr_Clear(): 1233. clears the exception state.

The full exception state consists of three objects (all of which can be
‘NULL’): the exception type, the corresponding exception value, and the
traceback.  These have the same meanings as the Python result of
‘sys.exc_info()’; however, they are not the same: the Python objects
represent the last exception being handled by a Python *note try: 8f9. …
*note except: 1ab. statement, while the C level exception state only
exists while an exception is being passed on between C functions until
it reaches the Python bytecode interpreter’s main loop, which takes care
of transferring it to ‘sys.exc_info()’ and friends.

Note that starting with Python 1.5, the preferred, thread-safe way to
access the exception state from Python code is to call the function
*note sys.exc_info(): 89b, which returns the per-thread exception state
for Python code.  Also, the semantics of both ways to access the
exception state have changed so that a function which catches an
exception will save and restore its thread’s exception state so as to
preserve the exception state of its caller.  This prevents common bugs
in exception handling code caused by an innocent-looking function
overwriting the exception being handled; it also reduces the often
unwanted lifetime extension for objects that are referenced by the stack
frames in the traceback.

As a general principle, a function that calls another function to
perform some task should check whether the called function raised an
exception, and if so, pass the exception state on to its caller.  It
should discard any object references that it owns, and return an error
indicator, but it should 'not' set another exception — that would
overwrite the exception that was just raised, and lose important
information about the exact cause of the error.

A simple example of detecting exceptions and passing them on is shown in
the ‘sum_sequence()’ example above.  It so happens that this example
doesn’t need to clean up any owned references when it detects an error.
The following example function shows some error cleanup.  First, to
remind you why you like Python, we show the equivalent Python code:

     def incr_item(dict, key):
         try:
             item = dict[key]
         except KeyError:
             item = 0
         dict[key] = item + 1

Here is the corresponding C code, in all its glory:

     int
     incr_item(PyObject *dict, PyObject *key)
     {
         /* Objects all initialized to NULL for Py_XDECREF */
         PyObject *item = NULL, *const_one = NULL, *incremented_item = NULL;
         int rv = -1; /* Return value initialized to -1 (failure) */

         item = PyObject_GetItem(dict, key);
         if (item == NULL) {
             /* Handle KeyError only: */
             if (!PyErr_ExceptionMatches(PyExc_KeyError))
                 goto error;

             /* Clear the error and use zero: */
             PyErr_Clear();
             item = PyLong_FromLong(0L);
             if (item == NULL)
                 goto error;
         }
         const_one = PyLong_FromLong(1L);
         if (const_one == NULL)
             goto error;

         incremented_item = PyNumber_Add(item, const_one);
         if (incremented_item == NULL)
             goto error;

         if (PyObject_SetItem(dict, key, incremented_item) < 0)
             goto error;
         rv = 0; /* Success */
         /* Continue with cleanup code */

      error:
         /* Cleanup code, shared by success and failure path */

         /* Use Py_XDECREF() to ignore NULL references */
         Py_XDECREF(item);
         Py_XDECREF(const_one);
         Py_XDECREF(incremented_item);

         return rv; /* -1 for error, 0 for success */
     }

This example represents an endorsed use of the ‘goto’ statement in C! It
illustrates the use of *note PyErr_ExceptionMatches(): 4f26. and *note
PyErr_Clear(): 1233. to handle specific exceptions, and the use of *note
Py_XDECREF(): 993. to dispose of owned references that may be ‘NULL’
(note the ‘'X'’ in the name; *note Py_DECREF(): 791. would crash when
confronted with a ‘NULL’ reference).  It is important that the variables
used to hold owned references are initialized to ‘NULL’ for this to
work; likewise, the proposed return value is initialized to ‘-1’
(failure) and only set to success after the final call made is
successful.


File: python.info,  Node: Embedding Python<2>,  Next: Debugging Builds,  Prev: Exceptions<23>,  Up: Introduction<13>

7.1.7 Embedding Python
----------------------

The one important task that only embedders (as opposed to extension
writers) of the Python interpreter have to worry about is the
initialization, and possibly the finalization, of the Python
interpreter.  Most functionality of the interpreter can only be used
after the interpreter has been initialized.

The basic initialization function is *note Py_Initialize(): 460.  This
initializes the table of loaded modules, and creates the fundamental
modules *note builtins: 13, *note __main__: 1, and *note sys: df.  It
also initializes the module search path (‘sys.path’).

*note Py_Initialize(): 460. does not set the «script argument list»
(‘sys.argv’).  If this variable is needed by Python code that will be
executed later, setting *note PyConfig.argv: 3f1. and *note
PyConfig.parse_argv: 1cd9. must be set: see *note Python Initialization
Configuration: 646.

On most systems (in particular, on Unix and Windows, although the
details are slightly different), *note Py_Initialize(): 460. calculates
the module search path based upon its best guess for the location of the
standard Python interpreter executable, assuming that the Python library
is found in a fixed location relative to the Python interpreter
executable.  In particular, it looks for a directory named
‘lib/python`X.Y'’ relative to the parent directory where the executable
named ‘python’ is found on the shell command search path (the
environment variable ‘PATH’).

For instance, if the Python executable is found in
‘/usr/local/bin/python’, it will assume that the libraries are in
‘/usr/local/lib/python`X.Y'’.  (In fact, this particular path is also
the «fallback» location, used when no executable file named ‘python’ is
found along ‘PATH’.)  The user can override this behavior by setting the
environment variable *note PYTHONHOME: 3f0, or insert additional
directories in front of the standard path by setting *note PYTHONPATH:
121f.

The embedding application can steer the search by setting *note
PyConfig.program_name: 3f2. 'before' calling *note
Py_InitializeFromConfig(): 3f6.  Note that *note PYTHONHOME: 3f0. still
overrides this and *note PYTHONPATH: 121f. is still inserted in front of
the standard path.  An application that requires total control has to
provide its own implementation of *note Py_GetPath(): 3e3, *note
Py_GetPrefix(): 3e5, *note Py_GetExecPrefix(): 3e9, and *note
Py_GetProgramFullPath(): 3ec. (all defined in ‘Modules/getpath.c’).

Sometimes, it is desirable to «uninitialize» Python.  For instance, the
application may want to start over (make another call to *note
Py_Initialize(): 460.) or the application is simply done with its use of
Python and wants to free memory allocated by Python.  This can be
accomplished by calling *note Py_FinalizeEx(): f13.  The function *note
Py_IsInitialized(): 4f29. returns true if Python is currently in the
initialized state.  More information about these functions is given in a
later chapter.  Notice that *note Py_FinalizeEx(): f13. does 'not' free
all memory allocated by the Python interpreter, e.g.  memory allocated
by extension modules currently cannot be released.


File: python.info,  Node: Debugging Builds,  Next: Recommended third party tools<2>,  Prev: Embedding Python<2>,  Up: Introduction<13>

7.1.8 Debugging Builds
----------------------

Python can be built with several macros to enable extra checks of the
interpreter and extension modules.  These checks tend to add a large
amount of overhead to the runtime so they are not enabled by default.

A full list of the various types of debugging builds is in the file
‘Misc/SpecialBuilds.txt’ in the Python source distribution.  Builds are
available that support tracing of reference counts, debugging the memory
allocator, or low-level profiling of the main interpreter loop.  Only
the most frequently used builds will be described in the remainder of
this section.

 -- C Macro: Py_DEBUG

Compiling the interpreter with the ‘Py_DEBUG’ macro defined produces
what is generally meant by *note a debug build of Python: 50a.
‘Py_DEBUG’ is enabled in the Unix build by adding *note -with-pydebug:
666. to the ‘./configure’ command.  It is also implied by the presence
of the not-Python-specific ‘_DEBUG’ macro.  When ‘Py_DEBUG’ is enabled
in the Unix build, compiler optimization is disabled.

In addition to the reference count debugging described below, extra
checks are performed, see *note Python Debug Build: 50a.

Defining ‘Py_TRACE_REFS’ enables reference tracing (see the *note
configure -with-trace-refs option: 636.).  When defined, a circular
doubly linked list of active objects is maintained by adding two extra
fields to every *note PyObject: 5df.  Total allocations are tracked as
well.  Upon exit, all existing references are printed.  (In interactive
mode this happens after every statement run by the interpreter.)

Please refer to ‘Misc/SpecialBuilds.txt’ in the Python source
distribution for more detailed information.


File: python.info,  Node: Recommended third party tools<2>,  Prev: Debugging Builds,  Up: Introduction<13>

7.1.9 Recommended third party tools
-----------------------------------

The following third party tools offer both simpler and more
sophisticated approaches to creating C, C++ and Rust extensions for
Python:

   * Cython(1)

   * cffi(2)

   * HPy(3)

   * nanobind(4) (C++)

   * Numba(5)

   * pybind11(6) (C++)

   * PyO3(7) (Rust)

   * SWIG(8)

Using tools such as these can help avoid writing code that is tightly
bound to a particular version of CPython, avoid reference counting
errors, and focus more on your own code than on using the CPython API.
In general, new versions of Python can be supported by updating the
tool, and your code will often use newer and more efficient APIs
automatically.  Some tools also support compiling for other
implementations of Python from a single set of sources.

These projects are not supported by the same people who maintain Python,
and issues need to be raised with the projects directly.  Remember to
check that the project is still maintained and supported, as the list
above may become outdated.

Vedi anche
..........

Python Packaging User Guide: Binary Extensions(9)

     The Python Packaging User Guide not only covers several available
     tools that simplify the creation of binary extensions, but also
     discusses the various reasons why creating an extension module may
     be desirable in the first place.

   ---------- Footnotes ----------

   (1) https://cython.org/

   (2) https://cffi.readthedocs.io

   (3) https://hpyproject.org/

   (4) https://github.com/wjakob/nanobind

   (5) https://numba.pydata.org/

   (6) https://pybind11.readthedocs.io/

   (7) https://pyo3.rs/

   (8) https://www.swig.org

   (9) https://packaging.python.org/guides/packaging-binary-extensions/


File: python.info,  Node: C API Stability,  Next: The Very High Level Layer,  Prev: Introduction<13>,  Up: Python/C API Reference Manual

7.2 C API Stability
===================

Unless documented otherwise, Python’s C API is covered by the Backwards
Compatibility Policy, PEP 387(1).  Most changes to it are
source-compatible (typically by only adding new API). Changing existing
API or removing API is only done after a deprecation period or to fix
serious issues.

CPython’s Application Binary Interface (ABI) is forward- and
backwards-compatible across a minor release (if these are compiled the
same way; see *note Platform Considerations: 4f30. below).  So, code
compiled for Python 3.10.0 will work on 3.10.8 and vice versa, but will
need to be compiled separately for 3.9.x and 3.11.x.

There are two tiers of C API with different stability expectations:

   - *note Unstable API: 76a, may change in minor versions without a
     deprecation period.  It is marked by the ‘PyUnstable’ prefix in
     names.

   - *note Limited API: 637, is compatible across several minor
     releases.  When *note Py_LIMITED_API: 660. is defined, only this
     subset is exposed from ‘Python.h’.

These are discussed in more detail below.

Names prefixed by an underscore, such as ‘_Py_InternalState’, are
private API that can change without notice even in patch releases.  If
you need to use this API, consider reaching out to CPython developers(2)
to discuss adding public API for your use case.

* Menu:

* Unstable C API::
* Stable Application Binary Interface::
* Platform Considerations::
* Contents of Limited API::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0387/

   (2) https://discuss.python.org/c/core-dev/c-api/30


File: python.info,  Node: Unstable C API,  Next: Stable Application Binary Interface,  Up: C API Stability

7.2.1 Unstable C API
--------------------

Any API named with the ‘PyUnstable’ prefix exposes CPython
implementation details, and may change in every minor release (e.g.
from 3.9 to 3.10) without any deprecation warnings.  However, it will
not change in a bugfix release (e.g.  from 3.10.0 to 3.10.1).

It is generally intended for specialized, low-level tools like
debuggers.

Projects that use this API are expected to follow CPython development
and spend extra effort adjusting to changes.


File: python.info,  Node: Stable Application Binary Interface,  Next: Platform Considerations,  Prev: Unstable C API,  Up: C API Stability

7.2.2 Stable Application Binary Interface
-----------------------------------------

For simplicity, this document talks about 'extensions', but the Limited
API and Stable ABI work the same way for all uses of the API – for
example, embedding Python.

* Menu:

* Limited C API::
* Stable ABI::
* Limited API Scope and Performance::
* Limited API Caveats::


File: python.info,  Node: Limited C API,  Next: Stable ABI,  Up: Stable Application Binary Interface

7.2.2.1 Limited C API
.....................

Python 3.2 introduced the 'Limited API', a subset of Python’s C API.
Extensions that only use the Limited API can be compiled once and be
loaded on multiple versions of Python.  Contents of the Limited API are
*note listed below: 99e.

 -- C Macro: Py_LIMITED_API

     Define this macro before including ‘Python.h’ to opt in to only use
     the Limited API, and to select the Limited API version.

     Define ‘Py_LIMITED_API’ to the value of *note PY_VERSION_HEX: 382.
     corresponding to the lowest Python version your extension supports.
     The extension will be ABI-compatible with all Python 3 releases
     from the specified one onward, and can use Limited API introduced
     up to that version.

     Rather than using the ‘PY_VERSION_HEX’ macro directly, hardcode a
     minimum minor version (e.g.  ‘0x030A0000’ for Python 3.10) for
     stability when compiling with future Python versions.

     You can also define ‘Py_LIMITED_API’ to ‘3’.  This works the same
     as ‘0x03020000’ (Python 3.2, the version that introduced Limited
     API).


File: python.info,  Node: Stable ABI,  Next: Limited API Scope and Performance,  Prev: Limited C API,  Up: Stable Application Binary Interface

7.2.2.2 Stable ABI
..................

To enable this, Python provides a 'Stable ABI': a set of symbols that
will remain ABI-compatible across Python 3.x versions.

     Nota: The Stable ABI prevents ABI issues, like linker errors due to
     missing symbols or data corruption due to changes in structure
     layouts or function signatures.  However, other changes in Python
     can change the 'behavior' of extensions.  See Python’s Backwards
     Compatibility Policy ( PEP 387(1)) for details.

The Stable ABI contains symbols exposed in the *note Limited API: 637,
but also other ones – for example, functions necessary to support older
versions of the Limited API.

On Windows, extensions that use the Stable ABI should be linked against
‘python3.dll’ rather than a version-specific library such as
‘python39.dll’.

On some platforms, Python will look for and load shared library files
named with the ‘abi3’ tag (e.g.  ‘mymodule.abi3.so’).  It does not check
if such extensions conform to a Stable ABI. The user (or their packaging
tools) need to ensure that, for example, extensions built with the 3.10+
Limited API are not installed for lower versions of Python.

All functions in the Stable ABI are present as functions in Python’s
shared library, not solely as macros.  This makes them usable from
languages that don’t use the C preprocessor.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0387/


File: python.info,  Node: Limited API Scope and Performance,  Next: Limited API Caveats,  Prev: Stable ABI,  Up: Stable Application Binary Interface

7.2.2.3 Limited API Scope and Performance
.........................................

The goal for the Limited API is to allow everything that is possible
with the full C API, but possibly with a performance penalty.

For example, while *note PyList_GetItem(): 5ff. is available, its
“unsafe” macro variant *note PyList_GET_ITEM(): 4f37. is not.  The macro
can be faster because it can rely on version-specific implementation
details of the list object.

Without ‘Py_LIMITED_API’ defined, some C API functions are inlined or
replaced by macros.  Defining ‘Py_LIMITED_API’ disables this inlining,
allowing stability as Python’s data structures are improved, but
possibly reducing performance.

By leaving out the ‘Py_LIMITED_API’ definition, it is possible to
compile a Limited API extension with a version-specific ABI. This can
improve performance for that Python version, but will limit
compatibility.  Compiling with ‘Py_LIMITED_API’ will then yield an
extension that can be distributed where a version-specific one is not
available – for example, for prereleases of an upcoming Python version.


File: python.info,  Node: Limited API Caveats,  Prev: Limited API Scope and Performance,  Up: Stable Application Binary Interface

7.2.2.4 Limited API Caveats
...........................

Note that compiling with ‘Py_LIMITED_API’ is 'not' a complete guarantee
that code conforms to the *note Limited API: 637. or the *note Stable
ABI: 4f35.  ‘Py_LIMITED_API’ only covers definitions, but an API also
includes other issues, such as expected semantics.

One issue that ‘Py_LIMITED_API’ does not guard against is calling a
function with arguments that are invalid in a lower Python version.  For
example, consider a function that starts accepting ‘NULL’ for an
argument.  In Python 3.9, ‘NULL’ now selects a default behavior, but in
Python 3.8, the argument will be used directly, causing a ‘NULL’
dereference and crash.  A similar argument works for fields of structs.

Another issue is that some struct fields are currently not hidden when
‘Py_LIMITED_API’ is defined, even though they’re part of the Limited
API.

For these reasons, we recommend testing an extension with 'all' minor
Python versions it supports, and preferably to build with the 'lowest'
such version.

We also recommend reviewing documentation of all used API to check if it
is explicitly part of the Limited API. Even with ‘Py_LIMITED_API’
defined, a few private declarations are exposed for technical reasons
(or even unintentionally, as bugs).

Also note that the Limited API is not necessarily stable: compiling with
‘Py_LIMITED_API’ with Python 3.8 means that the extension will run with
Python 3.12, but it will not necessarily 'compile' with Python 3.12.  In
particular, parts of the Limited API may be deprecated and removed,
provided that the Stable ABI stays stable.


File: python.info,  Node: Platform Considerations,  Next: Contents of Limited API,  Prev: Stable Application Binary Interface,  Up: C API Stability

7.2.3 Platform Considerations
-----------------------------

ABI stability depends not only on Python, but also on the compiler used,
lower-level libraries and compiler options.  For the purposes of the
*note Stable ABI: 4f35, these details define a “platform”.  They usually
depend on the OS type and processor architecture

It is the responsibility of each particular distributor of Python to
ensure that all Python versions on a particular platform are built in a
way that does not break the Stable ABI. This is the case with Windows
and macOS releases from ‘python.org’ and many third-party distributors.


File: python.info,  Node: Contents of Limited API,  Prev: Platform Considerations,  Up: C API Stability

7.2.4 Contents of Limited API
-----------------------------

Currently, the *note Limited API: 637. includes the following items:

   * *note METH_CLASS: 16dc.

   * *note METH_COEXIST: 167e.

   * *note METH_FASTCALL: 1986.

   * *note METH_METHOD: b6a.

   * *note METH_NOARGS: 16db.

   * *note METH_O: 170e.

   * *note METH_STATIC: 16dd.

   * *note METH_VARARGS: 170f.

   * *note PY_VECTORCALL_ARGUMENTS_OFFSET: 781.

   * *note PyAIter_Check(): 4f3b.

   * *note PyArg_Parse(): 17f6.

   * *note PyArg_ParseTuple(): 3c1.

   * *note PyArg_ParseTupleAndKeywords(): 624.

   * *note PyArg_UnpackTuple(): 170d.

   * *note PyArg_VaParse(): 4f3c.

   * *note PyArg_VaParseTupleAndKeywords(): 625.

   * *note PyArg_ValidateKeywordArguments(): 4f3d.

   * *note PyBUF_ANY_CONTIGUOUS: 4f3e.

   * *note PyBUF_CONTIG: 4f3f.

   * *note PyBUF_CONTIG_RO: 4f40.

   * *note PyBUF_C_CONTIGUOUS: 15be.

   * *note PyBUF_FORMAT: 4f41.

   * *note PyBUF_FULL: 4f42.

   * *note PyBUF_FULL_RO: 4f43.

   * *note PyBUF_F_CONTIGUOUS: 15bf.

   * *note PyBUF_INDIRECT: 4f44.

   * *note PyBUF_MAX_NDIM: 4f45.

   * *note PyBUF_ND: 4f46.

   * *note PyBUF_READ: 19f3.

   * *note PyBUF_RECORDS: 4f47.

   * *note PyBUF_RECORDS_RO: 4f48.

   * *note PyBUF_SIMPLE: 4f49.

   * *note PyBUF_STRIDED: 4f4a.

   * *note PyBUF_STRIDED_RO: 4f4b.

   * *note PyBUF_STRIDES: 4f4c.

   * *note PyBUF_WRITABLE: 15bd.

   * *note PyBUF_WRITE: 19f4.

   * *note PyBaseObject_Type: 4f4d.

   * *note PyBool_FromLong(): 4f4e.

   * *note PyBool_Type: 4f4f.

   * *note PyBuffer_FillContiguousStrides(): 964.

   * *note PyBuffer_FillInfo(): 965.

   * *note PyBuffer_FromContiguous(): 961.

   * *note PyBuffer_GetPointer(): 95e.

   * *note PyBuffer_IsContiguous(): 963.

   * *note PyBuffer_Release(): 63b.

   * *note PyBuffer_SizeFromFormat(): 95f.

   * *note PyBuffer_ToContiguous(): 960.

   * *note PyByteArrayIter_Type: 4f50.

   * *note PyByteArray_AsString(): 4f51.

   * *note PyByteArray_Concat(): 4f52.

   * *note PyByteArray_FromObject(): 15b0.

   * *note PyByteArray_FromStringAndSize(): 15b1.

   * *note PyByteArray_Resize(): 4f53.

   * *note PyByteArray_Size(): 4f54.

   * *note PyByteArray_Type: 4f55.

   * *note PyBytesIter_Type: 4f56.

   * *note PyBytes_AsString(): a89.

   * *note PyBytes_AsStringAndSize(): 4f57.

   * *note PyBytes_Concat(): 4f58.

   * *note PyBytes_ConcatAndDel(): 4f59.

   * *note PyBytes_DecodeEscape(): 4f5a.

   * *note PyBytes_FromFormat(): 1df3.

   * *note PyBytes_FromFormatV(): 4f5b.

   * *note PyBytes_FromObject(): 4f5c.

   * *note PyBytes_FromString(): 4f5d.

   * *note PyBytes_FromStringAndSize(): 15a8.

   * *note PyBytes_Repr(): 4f5e.

   * *note PyBytes_Size(): 4f5f.

   * *note PyBytes_Type: 4f60.

   * *note PyCFunction: 167f.

   * *note PyCFunctionFast: 4f61.

   * *note PyCFunctionFastWithKeywords: 4f62.

   * *note PyCFunctionWithKeywords: 4f63.

   * *note PyCFunction_GetFlags(): 4f64.

   * *note PyCFunction_GetFunction(): 4f65.

   * *note PyCFunction_GetSelf(): 4f66.

   * *note PyCFunction_New(): 1c99.

   * *note PyCFunction_NewEx(): 1d5e.

   * *note PyCFunction_Type: 4f67.

   * *note PyCMethod_New(): 1c93.

   * *note PyCallIter_New(): 4f68.

   * *note PyCallIter_Type: 4f69.

   * *note PyCallable_Check(): 4f6a.

   * *note PyCapsule_Destructor: 4f6b.

   * *note PyCapsule_GetContext(): 4f6c.

   * *note PyCapsule_GetDestructor(): 4f6d.

   * *note PyCapsule_GetName(): 4f6e.

   * *note PyCapsule_GetPointer(): 4f6f.

   * *note PyCapsule_Import(): 1bf8.

   * *note PyCapsule_IsValid(): 1564.

   * *note PyCapsule_New(): 4eac.

   * *note PyCapsule_SetContext(): 4f70.

   * *note PyCapsule_SetDestructor(): 4f71.

   * *note PyCapsule_SetName(): 4f72.

   * *note PyCapsule_SetPointer(): 4f73.

   * *note PyCapsule_Type: 4f74.

   * *note PyClassMethodDescr_Type: 4f75.

   * *note PyCodec_BackslashReplaceErrors(): 4f76.

   * *note PyCodec_Decode(): 3e1.

   * *note PyCodec_Decoder(): 4f77.

   * *note PyCodec_Encode(): 3e2.

   * *note PyCodec_Encoder(): 4f78.

   * *note PyCodec_IgnoreErrors(): 4f79.

   * *note PyCodec_IncrementalDecoder(): 4f7a.

   * *note PyCodec_IncrementalEncoder(): 4f7b.

   * *note PyCodec_KnownEncoding(): 4f7c.

   * *note PyCodec_LookupError(): 4f7d.

   * *note PyCodec_NameReplaceErrors(): 10b1.

   * *note PyCodec_Register(): 4f7e.

   * *note PyCodec_RegisterError(): 4f7f.

   * *note PyCodec_ReplaceErrors(): 4f80.

   * *note PyCodec_StreamReader(): 4f81.

   * *note PyCodec_StreamWriter(): 4f82.

   * *note PyCodec_StrictErrors(): 4f83.

   * *note PyCodec_Unregister(): a99.

   * *note PyCodec_XMLCharRefReplaceErrors(): 4f84.

   * *note PyComplex_FromDoubles(): 4f85.

   * *note PyComplex_ImagAsDouble(): 19fb.

   * *note PyComplex_RealAsDouble(): 19fa.

   * *note PyComplex_Type: 4f86.

   * *note PyDescr_NewClassMethod(): 4f87.

   * *note PyDescr_NewGetSet(): 4f88.

   * *note PyDescr_NewMember(): 4f89.

   * *note PyDescr_NewMethod(): 1d5d.

   * *note PyDictItems_Type: 4f8a.

   * *note PyDictIterItem_Type: 4f8b.

   * *note PyDictIterKey_Type: 4f8c.

   * *note PyDictIterValue_Type: 4f8d.

   * *note PyDictKeys_Type: 4f8e.

   * *note PyDictProxy_New(): 4f8f.

   * *note PyDictProxy_Type: 4f90.

   * *note PyDictRevIterItem_Type: 4f91.

   * *note PyDictRevIterKey_Type: 4f92.

   * *note PyDictRevIterValue_Type: 4f93.

   * *note PyDictValues_Type: 4f94.

   * *note PyDict_Clear(): 4f95.

   * *note PyDict_Contains(): 5de.

   * *note PyDict_Copy(): 662.

   * *note PyDict_DelItem(): 4f96.

   * *note PyDict_DelItemString(): 4f97.

   * *note PyDict_GetItem(): 628.

   * *note PyDict_GetItemRef(): 5e0.

   * *note PyDict_GetItemString(): 629.

   * *note PyDict_GetItemStringRef(): 421.

   * *note PyDict_GetItemWithError(): 5e1.

   * *note PyDict_Items(): 4f98.

   * *note PyDict_Keys(): 4f99.

   * *note PyDict_Merge(): 4f9a.

   * *note PyDict_MergeFromSeq2(): 4f9b.

   * *note PyDict_New(): 4f9c.

   * *note PyDict_Next(): 1977.

   * *note PyDict_SetItem(): 4ea2.

   * *note PyDict_SetItemString(): 1975.

   * *note PyDict_Size(): 4f9d.

   * *note PyDict_Type: 4f9e.

   * *note PyDict_Update(): 4f9f.

   * *note PyDict_Values(): 4fa0.

   * *note PyEllipsis_Type: 4fa1.

   * *note PyEnum_Type: 4fa2.

   * *note PyErr_BadArgument(): 4fa3.

   * *note PyErr_BadInternalCall(): 4fa4.

   * *note PyErr_CheckSignals(): 694.

   * *note PyErr_Clear(): 1233.

   * ‘PyErr_Display()’

   * *note PyErr_DisplayException(): 435.

   * *note PyErr_ExceptionMatches(): 4f26.

   * *note PyErr_Fetch(): 428.

   * *note PyErr_Format(): 10b3.

   * *note PyErr_FormatV(): 10b2.

   * *note PyErr_GetExcInfo(): 977.

   * *note PyErr_GetHandledException(): 974.

   * *note PyErr_GetRaisedException(): 429.

   * *note PyErr_GivenExceptionMatches(): 4fa5.

   * *note PyErr_NewException(): 1471.

   * *note PyErr_NewExceptionWithDoc(): 1470.

   * *note PyErr_NoMemory(): 4e82.

   * *note PyErr_NormalizeException(): 42a.

   * *note PyErr_Occurred(): 1c97.

   * *note PyErr_Print(): 1d14.

   * *note PyErr_PrintEx(): 4fa6.

   * *note PyErr_ProgramText(): 4fa7.

   * *note PyErr_ResourceWarning(): f15.

   * *note PyErr_Restore(): 42b.

   * *note PyErr_SetExcFromWindowsErr(): 4fa8.

   * *note PyErr_SetExcFromWindowsErrWithFilename(): 1a6e.

   * *note PyErr_SetExcFromWindowsErrWithFilenameObject(): 4fa9.

   * *note PyErr_SetExcFromWindowsErrWithFilenameObjects(): 4faa.

   * *note PyErr_SetExcInfo(): 976.

   * *note PyErr_SetFromErrno(): 4e81.

   * *note PyErr_SetFromErrnoWithFilename(): 1a6d.

   * *note PyErr_SetFromErrnoWithFilenameObject(): 4fab.

   * *note PyErr_SetFromErrnoWithFilenameObjects(): 4fac.

   * *note PyErr_SetFromWindowsErr(): 4fad.

   * *note PyErr_SetFromWindowsErrWithFilename(): 1a6f.

   * *note PyErr_SetHandledException(): 975.

   * *note PyErr_SetImportError(): f3b.

   * *note PyErr_SetImportErrorSubclass(): f14.

   * *note PyErr_SetInterrupt(): 4fae.

   * *note PyErr_SetInterruptEx(): aa0.

   * *note PyErr_SetNone(): 4faf.

   * *note PyErr_SetObject(): 79c.

   * *note PyErr_SetRaisedException(): 42c.

   * *note PyErr_SetString(): 79d.

   * *note PyErr_SyntaxLocation(): 4fb0.

   * *note PyErr_SyntaxLocationEx(): 4fb1.

   * *note PyErr_WarnEx(): 1653.

   * *note PyErr_WarnExplicit(): 1a75.

   * *note PyErr_WarnFormat(): 4fb2.

   * *note PyErr_WriteUnraisable(): 5f2.

   * *note PyEval_AcquireThread(): 649.

   * *note PyEval_EvalCode(): a88.

   * *note PyEval_EvalCodeEx(): 1ac2.

   * *note PyEval_EvalFrame(): 4fb3.

   * *note PyEval_EvalFrameEx(): 1230.

   * *note PyEval_GetBuiltins(): 5f4.

   * *note PyEval_GetFrame(): 1b21.

   * *note PyEval_GetFrameBuiltins(): 5f3.

   * *note PyEval_GetFrameGlobals(): 5f5.

   * *note PyEval_GetFrameLocals(): 5f7.

   * *note PyEval_GetFuncDesc(): 4fb4.

   * *note PyEval_GetFuncName(): 4fb5.

   * *note PyEval_GetGlobals(): 5f6.

   * *note PyEval_GetLocals(): 5f8.

   * *note PyEval_InitThreads(): 19a1.

   * *note PyEval_ReleaseThread(): 4fb6.

   * *note PyEval_RestoreThread(): 648.

   * *note PyEval_SaveThread(): 647.

   * *note PyExc_ArithmeticError: 4fb7.

   * *note PyExc_AssertionError: 4fb8.

   * *note PyExc_AttributeError: 4fb9.

   * *note PyExc_BaseException: 4fba.

   * *note PyExc_BaseExceptionGroup: 4fbb.

   * *note PyExc_BlockingIOError: 4fbc.

   * *note PyExc_BrokenPipeError: 4fbd.

   * *note PyExc_BufferError: 4fbe.

   * *note PyExc_BytesWarning: 4fbf.

   * *note PyExc_ChildProcessError: 4fc0.

   * *note PyExc_ConnectionAbortedError: 4fc1.

   * *note PyExc_ConnectionError: 4fc2.

   * *note PyExc_ConnectionRefusedError: 4fc3.

   * *note PyExc_ConnectionResetError: 4fc4.

   * *note PyExc_DeprecationWarning: 4fc5.

   * *note PyExc_EOFError: 4fc6.

   * *note PyExc_EncodingWarning: 4fc7.

   * *note PyExc_EnvironmentError: 4fc8.

   * *note PyExc_Exception: 4fc9.

   * *note PyExc_FileExistsError: 4fca.

   * *note PyExc_FileNotFoundError: 4fcb.

   * *note PyExc_FloatingPointError: 4fcc.

   * *note PyExc_FutureWarning: 4fcd.

   * *note PyExc_GeneratorExit: 4fce.

   * *note PyExc_IOError: 4fcf.

   * *note PyExc_ImportError: 4fd0.

   * *note PyExc_ImportWarning: 4fd1.

   * *note PyExc_IndentationError: 4fd2.

   * *note PyExc_IndexError: 4fd3.

   * *note PyExc_InterruptedError: 4fd4.

   * *note PyExc_IsADirectoryError: 4fd5.

   * *note PyExc_KeyError: 4fd6.

   * *note PyExc_KeyboardInterrupt: 4fd7.

   * *note PyExc_LookupError: 4fd8.

   * *note PyExc_MemoryError: 4fd9.

   * *note PyExc_ModuleNotFoundError: 4fda.

   * *note PyExc_NameError: 4fdb.

   * *note PyExc_NotADirectoryError: 4fdc.

   * *note PyExc_NotImplementedError: 4fdd.

   * *note PyExc_OSError: 4e84.

   * *note PyExc_OverflowError: 4fde.

   * *note PyExc_PendingDeprecationWarning: 4fdf.

   * *note PyExc_PermissionError: 4fe0.

   * *note PyExc_ProcessLookupError: 4fe1.

   * *note PyExc_RecursionError: 10b4.

   * *note PyExc_ReferenceError: 4fe2.

   * *note PyExc_ResourceWarning: 4fe3.

   * *note PyExc_RuntimeError: 4fe4.

   * *note PyExc_RuntimeWarning: 4fe5.

   * *note PyExc_StopAsyncIteration: 4fe6.

   * *note PyExc_StopIteration: 4fe7.

   * *note PyExc_SyntaxError: 4fe8.

   * *note PyExc_SyntaxWarning: 4fe9.

   * *note PyExc_SystemError: 4fea.

   * *note PyExc_SystemExit: 4feb.

   * *note PyExc_TabError: 4fec.

   * *note PyExc_TimeoutError: 4fed.

   * *note PyExc_TypeError: 4e83.

   * *note PyExc_UnboundLocalError: 4fee.

   * *note PyExc_UnicodeDecodeError: 4fef.

   * *note PyExc_UnicodeEncodeError: 4ff0.

   * *note PyExc_UnicodeError: 4ff1.

   * *note PyExc_UnicodeTranslateError: 4ff2.

   * *note PyExc_UnicodeWarning: 4ff3.

   * *note PyExc_UserWarning: 4ff4.

   * *note PyExc_ValueError: 4e85.

   * *note PyExc_Warning: 4ff5.

   * *note PyExc_WindowsError: 4ff6.

   * *note PyExc_ZeroDivisionError: 4e80.

   * *note PyExceptionClass_Name(): c5d.

   * *note PyException_GetArgs(): 78c.

   * *note PyException_GetCause(): 4ff7.

   * *note PyException_GetContext(): 4ff8.

   * *note PyException_GetTraceback(): 4ff9.

   * *note PyException_SetArgs(): 78d.

   * *note PyException_SetCause(): 4ffa.

   * *note PyException_SetContext(): 4ffb.

   * *note PyException_SetTraceback(): 1db6.

   * *note PyFile_FromFd(): 4ffc.

   * *note PyFile_GetLine(): 4ffd.

   * *note PyFile_WriteObject(): 4ffe.

   * *note PyFile_WriteString(): 4fff.

   * *note PyFilter_Type: 5000.

   * *note PyFloat_AsDouble(): c61.

   * *note PyFloat_FromDouble(): 5001.

   * *note PyFloat_FromString(): 5002.

   * *note PyFloat_GetInfo(): 15f7.

   * *note PyFloat_GetMax(): 15f5.

   * *note PyFloat_GetMin(): 15f6.

   * *note PyFloat_Type: 5003.

   * *note PyFrameObject: 98d.

   * *note PyFrame_GetCode(): 98e.

   * *note PyFrame_GetLineNumber(): 98f.

   * *note PyFrozenSet_New(): 164c.

   * *note PyFrozenSet_Type: 5004.

   * *note PyGC_Collect(): b87.

   * *note PyGC_Disable(): aa7.

   * *note PyGC_Enable(): aa6.

   * *note PyGC_IsEnabled(): aa8.

   * *note PyGILState_Ensure(): 64a.

   * *note PyGILState_GetThisThreadState(): 5005.

   * *note PyGILState_Release(): 64b.

   * *note PyGILState_STATE: 5006.

   * *note PyGetSetDef: db4.

   * *note PyGetSetDescr_Type: 5007.

   * *note PyImport_AddModule(): 5fc.

   * *note PyImport_AddModuleObject(): 5008.

   * *note PyImport_AddModuleRef(): 5fb.

   * *note PyImport_AppendInittab(): 1b04.

   * *note PyImport_ExecCodeModule(): 5009.

   * *note PyImport_ExecCodeModuleEx(): 500a.

   * *note PyImport_ExecCodeModuleObject(): 500b.

   * *note PyImport_ExecCodeModuleWithPathnames(): 500c.

   * *note PyImport_GetImporter(): 1a6c.

   * *note PyImport_GetMagicNumber(): 13ab.

   * *note PyImport_GetMagicTag(): 500d.

   * *note PyImport_GetModule(): dae.

   * *note PyImport_GetModuleDict(): 500e.

   * *note PyImport_Import(): 1603.

   * *note PyImport_ImportFrozenModule(): 500f.

   * *note PyImport_ImportFrozenModuleObject(): 5010.

   * *note PyImport_ImportModule(): 3dc.

   * *note PyImport_ImportModuleLevel(): 13ac.

   * *note PyImport_ImportModuleLevelObject(): 5011.

   * *note PyImport_ImportModuleNoBlock(): 3db.

   * *note PyImport_ReloadModule(): 5012.

   * *note PyIndex_Check(): b83.

   * *note PyInterpreterState: abc.

   * *note PyInterpreterState_Clear(): 473b.

   * *note PyInterpreterState_Delete(): 5013.

   * *note PyInterpreterState_Get(): 64c.

   * *note PyInterpreterState_GetDict(): 5014.

   * *note PyInterpreterState_GetID(): dc1.

   * *note PyInterpreterState_New(): 473c.

   * *note PyIter_Check(): 1c9a.

   * *note PyIter_Next(): 399.

   * *note PyIter_NextItem(): 398.

   * *note PyIter_Send(): a9a.

   * *note PyListIter_Type: 5015.

   * *note PyListRevIter_Type: 5016.

   * *note PyList_Append(): 5017.

   * *note PyList_AsTuple(): 5018.

   * *note PyList_GetItem(): 5ff.

   * *note PyList_GetItemRef(): 5fe.

   * *note PyList_GetSlice(): 5019.

   * *note PyList_Insert(): 18a1.

   * *note PyList_New(): 4f21.

   * *note PyList_Reverse(): 501a.

   * *note PyList_SetItem(): 18a2.

   * *note PyList_SetSlice(): 501b.

   * *note PyList_Size(): 1621.

   * *note PyList_Sort(): 501c.

   * *note PyList_Type: 4ec4.

   * *note PyLongObject: 39e.

   * *note PyLongRangeIter_Type: 501d.

   * *note PyLong_AsDouble(): 195d.

   * *note PyLong_AsInt(): 604.

   * *note PyLong_AsInt32(): 39f.

   * *note PyLong_AsInt64(): 3a0.

   * *note PyLong_AsLong(): 605.

   * *note PyLong_AsLongAndOverflow(): 146e.

   * *note PyLong_AsLongLong(): 501e.

   * *note PyLong_AsLongLongAndOverflow(): 146d.

   * *note PyLong_AsNativeBytes(): 606.

   * *note PyLong_AsSize_t(): 501f.

   * *note PyLong_AsSsize_t(): 5020.

   * *note PyLong_AsUInt32(): 3a1.

   * *note PyLong_AsUInt64(): 3a2.

   * *note PyLong_AsUnsignedLong(): 5021.

   * *note PyLong_AsUnsignedLongLong(): 149c.

   * *note PyLong_AsUnsignedLongLongMask(): 1db2.

   * *note PyLong_AsUnsignedLongMask(): 5022.

   * *note PyLong_AsVoidPtr(): 5023.

   * *note PyLong_FromDouble(): b3e.

   * *note PyLong_FromInt32(): 3a3.

   * *note PyLong_FromInt64(): 3a4.

   * *note PyLong_FromLong(): 1bb8.

   * *note PyLong_FromLongLong(): 1bb9.

   * *note PyLong_FromNativeBytes(): 607.

   * *note PyLong_FromSize_t(): 18a7.

   * *note PyLong_FromSsize_t(): 1886.

   * *note PyLong_FromString(): 5024.

   * *note PyLong_FromUInt32(): 3a5.

   * *note PyLong_FromUInt64(): 3a6.

   * *note PyLong_FromUnsignedLong(): 18a5.

   * *note PyLong_FromUnsignedLongLong(): 18a6.

   * *note PyLong_FromUnsignedNativeBytes(): 608.

   * *note PyLong_FromVoidPtr(): 5025.

   * *note PyLong_GetInfo(): 5026.

   * *note PyLong_Type: 5027.

   * *note PyMap_Type: 5028.

   * *note PyMapping_Check(): 5029.

   * *note PyMapping_GetItemString(): 5eb.

   * *note PyMapping_GetOptionalItem(): 5e8.

   * *note PyMapping_GetOptionalItemString(): 5e9.

   * *note PyMapping_HasKey(): 620.

   * *note PyMapping_HasKeyString(): 622.

   * *note PyMapping_HasKeyStringWithError(): 621.

   * *note PyMapping_HasKeyWithError(): 61f.

   * *note PyMapping_Items(): db9.

   * *note PyMapping_Keys(): db7.

   * *note PyMapping_Length(): 502a.

   * *note PyMapping_SetItemString(): 502b.

   * *note PyMapping_Size(): 1e1f.

   * *note PyMapping_Values(): db8.

   * *note PyMem_Calloc(): 10af.

   * *note PyMem_Free(): 1649.

   * *note PyMem_Malloc(): e62.

   * *note PyMem_RawCalloc(): 632.

   * *note PyMem_RawFree(): 634.

   * *note PyMem_RawMalloc(): 631.

   * *note PyMem_RawRealloc(): 633.

   * *note PyMem_Realloc(): 1234.

   * *note PyMemberDef: 772.

   * *note PyMemberDescr_Type: 502c.

   * *note PyMember_GetOne(): 7ab.

   * *note PyMember_SetOne(): 7ac.

   * *note PyMemoryView_FromBuffer(): 966.

   * *note PyMemoryView_FromMemory(): 1378.

   * *note PyMemoryView_FromObject(): 502d.

   * *note PyMemoryView_GetContiguous(): 502e.

   * *note PyMemoryView_Type: 502f.

   * *note PyMethodDef: 16de.

   * *note PyMethodDescr_Type: 5030.

   * *note PyModuleDef: b76.

   * ‘PyModuleDef_Base’

   * *note PyModuleDef_Init(): 4e8c.

   * *note PyModuleDef_Slot: 5031.

   * ‘PyModuleDef_Type’

   * *note PyModule_Add(): 609.

   * *note PyModule_AddFunctions(): 5032.

   * *note PyModule_AddIntConstant(): 1743.

   * *note PyModule_AddObject(): 60b.

   * *note PyModule_AddObjectRef(): 60a.

   * *note PyModule_AddStringConstant(): 1744.

   * *note PyModule_AddType(): b6e.

   * *note PyModule_Create2(): 5033.

   * *note PyModule_ExecDef(): 10b7.

   * *note PyModule_FromDefAndSpec2(): 10b6.

   * *note PyModule_GetDef(): 5034.

   * *note PyModule_GetDict(): 5035.

   * *note PyModule_GetFilename(): 42d.

   * *note PyModule_GetFilenameObject(): 42e.

   * *note PyModule_GetName(): 5036.

   * *note PyModule_GetNameObject(): 5037.

   * *note PyModule_GetState(): b79.

   * *note PyModule_New(): 5038.

   * *note PyModule_NewObject(): 5039.

   * *note PyModule_SetDocString(): 503a.

   * *note PyModule_Type: 503b.

   * *note PyNumber_Absolute(): 503c.

   * *note PyNumber_Add(): 503d.

   * *note PyNumber_And(): 503e.

   * *note PyNumber_AsSsize_t(): 503f.

   * *note PyNumber_Check(): c5e.

   * *note PyNumber_Divmod(): 5040.

   * *note PyNumber_Float(): c60.

   * *note PyNumber_FloorDivide(): 5041.

   * *note PyNumber_InPlaceAdd(): 5042.

   * *note PyNumber_InPlaceAnd(): 5043.

   * *note PyNumber_InPlaceFloorDivide(): 5044.

   * *note PyNumber_InPlaceLshift(): 5045.

   * *note PyNumber_InPlaceMatrixMultiply(): 10b9.

   * *note PyNumber_InPlaceMultiply(): 5046.

   * *note PyNumber_InPlaceOr(): 5047.

   * *note PyNumber_InPlacePower(): 5048.

   * *note PyNumber_InPlaceRemainder(): 5049.

   * *note PyNumber_InPlaceRshift(): 504a.

   * *note PyNumber_InPlaceSubtract(): 504b.

   * *note PyNumber_InPlaceTrueDivide(): 504c.

   * *note PyNumber_InPlaceXor(): 504d.

   * *note PyNumber_Index(): a95.

   * *note PyNumber_Invert(): 504e.

   * *note PyNumber_Long(): c5f.

   * *note PyNumber_Lshift(): 504f.

   * *note PyNumber_MatrixMultiply(): 10b8.

   * *note PyNumber_Multiply(): 5050.

   * *note PyNumber_Negative(): 5051.

   * *note PyNumber_Or(): 5052.

   * *note PyNumber_Positive(): 5053.

   * *note PyNumber_Power(): 5054.

   * *note PyNumber_Remainder(): 5055.

   * *note PyNumber_Rshift(): 5056.

   * *note PyNumber_Subtract(): 5057.

   * *note PyNumber_ToBase(): 1b5b.

   * *note PyNumber_TrueDivide(): 5058.

   * *note PyNumber_Xor(): 5059.

   * *note PyOS_AfterFork(): 42f.

   * *note PyOS_AfterFork_Child(): 430.

   * *note PyOS_AfterFork_Parent(): dbb.

   * *note PyOS_BeforeFork(): dba.

   * *note PyOS_CheckStack(): 1b89.

   * *note PyOS_FSPath(): f16.

   * *note PyOS_InputHook: 7a5.

   * *note PyOS_InterruptOccurred(): 1d2a.

   * *note PyOS_double_to_string(): 505a.

   * *note PyOS_getsig(): 1745.

   * *note PyOS_mystricmp(): 1d23.

   * *note PyOS_mystrnicmp(): 1d22.

   * *note PyOS_setsig(): 1746.

   * *note PyOS_sighandler_t: 505b.

   * *note PyOS_snprintf(): 1710.

   * *note PyOS_string_to_double(): 149d.

   * *note PyOS_strtol(): 505c.

   * *note PyOS_strtoul(): 505d.

   * *note PyOS_vsnprintf(): 1711.

   * *note PyObject: 5df.

   * *note PyObject.ob_refcnt: aa1.

   * *note PyObject.ob_type: 4eb6.

   * *note PyObject_ASCII(): 505e.

   * *note PyObject_AsFileDescriptor(): 505f.

   * *note PyObject_Bytes(): 5060.

   * *note PyObject_Call(): 63d.

   * *note PyObject_CallFunction(): 63f.

   * *note PyObject_CallFunctionObjArgs(): 5061.

   * *note PyObject_CallMethod(): 640.

   * *note PyObject_CallMethodObjArgs(): 1dc7.

   * *note PyObject_CallNoArgs(): 63c.

   * *note PyObject_CallObject(): 4e95.

   * *note PyObject_Calloc(): 10b0.

   * *note PyObject_CheckBuffer(): 639.

   * *note PyObject_ClearWeakRefs(): 797.

   * *note PyObject_CopyData(): 962.

   * *note PyObject_DelAttr(): 1819.

   * *note PyObject_DelAttrString(): 181a.

   * *note PyObject_DelItem(): 5062.

   * *note PyObject_DelItemString(): 5063.

   * *note PyObject_Dir(): 5064.

   * *note PyObject_Format(): 5065.

   * *note PyObject_Free(): e61.

   * *note PyObject_GC_Del(): 170a.

   * *note PyObject_GC_IsFinalized(): b70.

   * *note PyObject_GC_IsTracked(): b6f.

   * *note PyObject_GC_Track(): 170b.

   * *note PyObject_GC_UnTrack(): 170c.

   * *note PyObject_GenericGetAttr(): 5066.

   * *note PyObject_GenericGetDict(): 1ced.

   * *note PyObject_GenericSetAttr(): 5067.

   * *note PyObject_GenericSetDict(): 5068.

   * *note PyObject_GetAIter(): 5069.

   * *note PyObject_GetAttr(): 5ee.

   * *note PyObject_GetAttrString(): 5ef.

   * *note PyObject_GetBuffer(): 63a.

   * *note PyObject_GetItem(): 5ea.

   * *note PyObject_GetIter(): 506a.

   * *note PyObject_GetOptionalAttr(): 5ec.

   * *note PyObject_GetOptionalAttrString(): 5ed.

   * *note PyObject_GetTypeData(): 76c.

   * *note PyObject_HasAttr(): 61c.

   * *note PyObject_HasAttrString(): 61e.

   * *note PyObject_HasAttrStringWithError(): 61d.

   * *note PyObject_HasAttrWithError(): 61b.

   * *note PyObject_Hash(): 436.

   * *note PyObject_HashNotImplemented(): 15ce.

   * *note PyObject_Init(): c62.

   * *note PyObject_InitVar(): 1d28.

   * *note PyObject_IsInstance(): 10a8.

   * *note PyObject_IsSubclass(): 10a9.

   * *note PyObject_IsTrue(): 506b.

   * *note PyObject_Length(): 506c.

   * *note PyObject_Malloc(): e64.

   * *note PyObject_Not(): 506d.

   * *note PyObject_Realloc(): 164a.

   * *note PyObject_Repr(): 1231.

   * *note PyObject_RichCompare(): 4eda.

   * *note PyObject_RichCompareBool(): 1d74.

   * *note PyObject_SelfIter(): 506e.

   * *note PyObject_SetAttr(): 506f.

   * *note PyObject_SetAttrString(): 1976.

   * *note PyObject_SetItem(): 4f20.

   * *note PyObject_Size(): 5070.

   * *note PyObject_Str(): 1232.

   * *note PyObject_Type(): 5071.

   * *note PyObject_Vectorcall(): 77f.

   * *note PyObject_VectorcallMethod(): 780.

   * *note PyProperty_Type: 5072.

   * *note PyRangeIter_Type: 5073.

   * *note PyRange_Type: 5074.

   * *note PyReversed_Type: 5075.

   * *note PySeqIter_New(): 5076.

   * *note PySeqIter_Type: 5077.

   * *note PySequence_Check(): 5078.

   * *note PySequence_Concat(): 5079.

   * *note PySequence_Contains(): 3d9.

   * *note PySequence_Count(): 507a.

   * *note PySequence_DelItem(): 1e1e.

   * *note PySequence_DelSlice(): 507b.

   * *note PySequence_Fast(): 188a.

   * *note PySequence_GetItem(): 1e1c.

   * *note PySequence_GetSlice(): 507c.

   * *note PySequence_In(): 3d8.

   * *note PySequence_InPlaceConcat(): 507d.

   * *note PySequence_InPlaceRepeat(): 507e.

   * *note PySequence_Index(): 507f.

   * *note PySequence_Length(): 5080.

   * *note PySequence_List(): 5081.

   * *note PySequence_Repeat(): 5082.

   * *note PySequence_SetItem(): 1e1d.

   * *note PySequence_SetSlice(): 5083.

   * *note PySequence_Size(): 1e1b.

   * *note PySequence_Tuple(): 5084.

   * *note PySetIter_Type: 5085.

   * *note PySet_Add(): 164d.

   * *note PySet_Clear(): 5086.

   * *note PySet_Contains(): 164f.

   * *note PySet_Discard(): 164e.

   * *note PySet_New(): 164b.

   * *note PySet_Pop(): 5087.

   * *note PySet_Size(): 1650.

   * *note PySet_Type: 5088.

   * *note PySlice_AdjustIndices(): 433.

   * *note PySlice_GetIndices(): 5089.

   * *note PySlice_GetIndicesEx(): 431.

   * *note PySlice_New(): 508a.

   * *note PySlice_Type: 508b.

   * *note PySlice_Unpack(): 432.

   * *note PyState_AddModule(): 508c.

   * *note PyState_FindModule(): 508d.

   * *note PyState_RemoveModule(): 508e.

   * *note PyStructSequence_Desc: db6.

   * *note PyStructSequence_Field: db5.

   * *note PyStructSequence_GetItem(): 508f.

   * *note PyStructSequence_New(): 5090.

   * *note PyStructSequence_NewType(): 5091.

   * *note PyStructSequence_SetItem(): 5092.

   * *note PyStructSequence_UnnamedField: b7b.

   * *note PySuper_Type: 5093.

   * *note PySys_Audit(): 613.

   * *note PySys_AuditTuple(): 612.

   * *note PySys_FormatStderr(): 5094.

   * *note PySys_FormatStdout(): 5095.

   * *note PySys_GetObject(): 62a.

   * *note PySys_GetXOptions(): 5096.

   * *note PySys_ResetWarnOptions(): 3f4.

   * *note PySys_SetArgv(): 19a0.

   * *note PySys_SetArgvEx(): 199f.

   * *note PySys_SetObject(): 5097.

   * *note PySys_WriteStderr(): 5098.

   * *note PySys_WriteStdout(): 5099.

   * *note PyThreadState: 991.

   * *note PyThreadState_Clear(): 1979.

   * *note PyThreadState_Delete(): 1d71.

   * *note PyThreadState_Get(): 615.

   * *note PyThreadState_GetDict(): 509a.

   * *note PyThreadState_GetFrame(): 992.

   * *note PyThreadState_GetID(): b6c.

   * *note PyThreadState_GetInterpreter(): b6b.

   * *note PyThreadState_New(): 509b.

   * *note PyThreadState_SetAsyncExc(): dbf.

   * *note PyThreadState_Swap(): 509c.

   * *note PyThread_GetInfo(): 509d.

   * *note PyThread_ReInitTLS(): 441.

   * *note PyThread_acquire_lock(): 509e.

   * *note PyThread_acquire_lock_timed(): 509f.

   * *note PyThread_allocate_lock(): 50a0.

   * *note PyThread_create_key(): 437.

   * *note PyThread_delete_key(): 439.

   * *note PyThread_delete_key_value(): 43f.

   * *note PyThread_exit_thread(): 50a1.

   * *note PyThread_free_lock(): 50a2.

   * *note PyThread_get_key_value(): 43d.

   * *note PyThread_get_stacksize(): 50a3.

   * *note PyThread_get_thread_ident(): 50a4.

   * *note PyThread_get_thread_native_id(): 1b8a.

   * *note PyThread_init_thread(): 50a5.

   * *note PyThread_release_lock(): 50a6.

   * *note PyThread_set_key_value(): 43b.

   * *note PyThread_set_stacksize(): 50a7.

   * *note PyThread_start_new_thread(): 1e13.

   * *note PyThread_tss_alloc(): 438.

   * *note PyThread_tss_create(): 50a8.

   * *note PyThread_tss_delete(): 440.

   * *note PyThread_tss_free(): 43a.

   * *note PyThread_tss_get(): 43e.

   * *note PyThread_tss_is_created(): 50a9.

   * *note PyThread_tss_set(): 43c.

   * *note PyTraceBack_Here(): 50aa.

   * *note PyTraceBack_Print(): 50ab.

   * *note PyTraceBack_Type: 50ac.

   * *note PyTupleIter_Type: 50ad.

   * *note PyTuple_GetItem(): 4ea0.

   * *note PyTuple_GetSlice(): 50ae.

   * *note PyTuple_New(): 63e.

   * *note PyTuple_Pack(): 50af.

   * *note PyTuple_SetItem(): 4ea1.

   * *note PyTuple_Size(): 50b0.

   * *note PyTuple_Type: 50b1.

   * *note PyTypeObject: c9e.

   * *note PyType_ClearCache(): 50b2.

   * *note PyType_Freeze(): 3af.

   * *note PyType_FromMetaclass(): 773.

   * *note PyType_FromModuleAndSpec(): 774.

   * *note PyType_FromSpec(): 79e.

   * *note PyType_FromSpecWithBases(): 79f.

   * *note PyType_GenericAlloc(): c63.

   * *note PyType_GenericNew(): 4eb5.

   * *note PyType_GetBaseByToken(): 3b0.

   * *note PyType_GetFlags(): 1d25.

   * *note PyType_GetFullyQualifiedName(): 616.

   * *note PyType_GetModule(): b68.

   * *note PyType_GetModuleByDef(): 635.

   * *note PyType_GetModuleName(): 618.

   * *note PyType_GetModuleState(): b69.

   * *note PyType_GetName(): 959.

   * *note PyType_GetQualName(): 95a.

   * *note PyType_GetSlot(): a9e.

   * *note PyType_GetTypeDataSize(): 76d.

   * *note PyType_IsSubtype(): 50b3.

   * *note PyType_Modified(): 1b63.

   * *note PyType_Ready(): 981.

   * *note PyType_Slot: 50b4.

   * *note PyType_Spec: 1a71.

   * *note PyType_Type: 770.

   * *note PyUnicodeDecodeError_Create(): 50b5.

   * *note PyUnicodeDecodeError_GetEncoding(): 50b6.

   * *note PyUnicodeDecodeError_GetEnd(): 50b7.

   * *note PyUnicodeDecodeError_GetObject(): 50b8.

   * *note PyUnicodeDecodeError_GetReason(): 50b9.

   * *note PyUnicodeDecodeError_GetStart(): 50ba.

   * *note PyUnicodeDecodeError_SetEnd(): 50bb.

   * *note PyUnicodeDecodeError_SetReason(): 50bc.

   * *note PyUnicodeDecodeError_SetStart(): 50bd.

   * *note PyUnicodeEncodeError_GetEncoding(): 50be.

   * *note PyUnicodeEncodeError_GetEnd(): 18e3.

   * *note PyUnicodeEncodeError_GetObject(): 50bf.

   * *note PyUnicodeEncodeError_GetReason(): 50c0.

   * *note PyUnicodeEncodeError_GetStart(): 18e6.

   * *note PyUnicodeEncodeError_SetEnd(): 50c1.

   * *note PyUnicodeEncodeError_SetReason(): 50c2.

   * *note PyUnicodeEncodeError_SetStart(): 50c3.

   * *note PyUnicodeIter_Type: 50c4.

   * *note PyUnicodeTranslateError_GetEnd(): 50c5.

   * *note PyUnicodeTranslateError_GetObject(): 50c6.

   * *note PyUnicodeTranslateError_GetReason(): 50c7.

   * *note PyUnicodeTranslateError_GetStart(): 50c8.

   * *note PyUnicodeTranslateError_SetEnd(): 50c9.

   * *note PyUnicodeTranslateError_SetReason(): 50ca.

   * *note PyUnicodeTranslateError_SetStart(): 50cb.

   * *note PyUnicode_Append(): 50cc.

   * *note PyUnicode_AppendAndDel(): 50cd.

   * *note PyUnicode_AsASCIIString(): 139a.

   * *note PyUnicode_AsCharmapString(): 50ce.

   * ‘PyUnicode_AsDecodedObject()’

   * ‘PyUnicode_AsDecodedUnicode()’

   * ‘PyUnicode_AsEncodedObject()’

   * *note PyUnicode_AsEncodedString(): 50cf.

   * ‘PyUnicode_AsEncodedUnicode()’

   * *note PyUnicode_AsLatin1String(): 1399.

   * *note PyUnicode_AsMBCSString(): 139b.

   * *note PyUnicode_AsRawUnicodeEscapeString(): 1398.

   * *note PyUnicode_AsUCS4(): 1380.

   * *note PyUnicode_AsUCS4Copy(): aba.

   * *note PyUnicode_AsUTF16String(): 50d0.

   * *note PyUnicode_AsUTF32String(): 50d1.

   * *note PyUnicode_AsUTF8AndSize(): a9b.

   * *note PyUnicode_AsUTF8String(): 1396.

   * *note PyUnicode_AsUnicodeEscapeString(): 1397.

   * *note PyUnicode_AsWideChar(): 1e20.

   * *note PyUnicode_AsWideCharString(): abb.

   * *note PyUnicode_BuildEncodingMap(): 1a4a.

   * *note PyUnicode_Compare(): ab6.

   * *note PyUnicode_CompareWithASCIIString(): 146f.

   * *note PyUnicode_Concat(): 13a9.

   * *note PyUnicode_Contains(): 50d2.

   * *note PyUnicode_Count(): 50d3.

   * *note PyUnicode_Decode(): 1daf.

   * *note PyUnicode_DecodeASCII(): 50d4.

   * *note PyUnicode_DecodeCharmap(): 50d5.

   * *note PyUnicode_DecodeCodePageStateful(): 50d6.

   * *note PyUnicode_DecodeFSDefault(): 1a70.

   * *note PyUnicode_DecodeFSDefaultAndSize(): 50d7.

   * *note PyUnicode_DecodeLatin1(): 50d8.

   * *note PyUnicode_DecodeLocale(): 50d9.

   * *note PyUnicode_DecodeLocaleAndSize(): dc4.

   * *note PyUnicode_DecodeMBCS(): 50da.

   * *note PyUnicode_DecodeMBCSStateful(): 50db.

   * *note PyUnicode_DecodeRawUnicodeEscape(): 50dc.

   * *note PyUnicode_DecodeUTF16(): 50dd.

   * *note PyUnicode_DecodeUTF16Stateful(): 50de.

   * *note PyUnicode_DecodeUTF32(): 50df.

   * *note PyUnicode_DecodeUTF32Stateful(): 50e0.

   * *note PyUnicode_DecodeUTF7(): 50e1.

   * *note PyUnicode_DecodeUTF7Stateful(): 50e2.

   * *note PyUnicode_DecodeUTF8(): 50e3.

   * *note PyUnicode_DecodeUTF8Stateful(): 1aff.

   * *note PyUnicode_DecodeUnicodeEscape(): 50e4.

   * *note PyUnicode_EncodeCodePage(): 139c.

   * *note PyUnicode_EncodeFSDefault(): 1e19.

   * *note PyUnicode_EncodeLocale(): dc5.

   * *note PyUnicode_Equal(): 3b2.

   * *note PyUnicode_EqualToUTF8(): 61a.

   * *note PyUnicode_EqualToUTF8AndSize(): 619.

   * *note PyUnicode_FSConverter(): f17.

   * *note PyUnicode_FSDecoder(): 798.

   * *note PyUnicode_Find(): 50e5.

   * *note PyUnicode_FindChar(): ab8.

   * *note PyUnicode_Format(): 50e6.

   * *note PyUnicode_FromEncodedObject(): 50e7.

   * *note PyUnicode_FromFormat(): 62b.

   * *note PyUnicode_FromFormatV(): 795.

   * *note PyUnicode_FromObject(): 50e8.

   * *note PyUnicode_FromOrdinal(): 50e9.

   * *note PyUnicode_FromString(): 50ea.

   * *note PyUnicode_FromStringAndSize(): 50eb.

   * *note PyUnicode_FromWideChar(): 1394.

   * *note PyUnicode_GetDefaultEncoding(): 50ec.

   * *note PyUnicode_GetLength(): ab2.

   * *note PyUnicode_InternFromString(): 1974.

   * *note PyUnicode_InternInPlace(): ab0.

   * *note PyUnicode_IsIdentifier(): 1d6e.

   * *note PyUnicode_Join(): 13aa.

   * *note PyUnicode_Partition(): 1880.

   * *note PyUnicode_RPartition(): 1881.

   * *note PyUnicode_RSplit(): 187f.

   * *note PyUnicode_ReadChar(): 1379.

   * *note PyUnicode_Replace(): 50ed.

   * *note PyUnicode_Resize(): 50ee.

   * *note PyUnicode_RichCompare(): 50ef.

   * *note PyUnicode_Split(): 50f0.

   * *note PyUnicode_Splitlines(): 50f1.

   * *note PyUnicode_Substring(): ab5.

   * *note PyUnicode_Tailmatch(): ab7.

   * *note PyUnicode_Translate(): 50f2.

   * *note PyUnicode_Type: 50f3.

   * *note PyUnicode_WriteChar(): 137a.

   * *note PyVarObject: 46be.

   * ‘PyVarObject.ob_base’

   * *note PyVarObject.ob_size: 50f4.

   * *note PyVectorcall_Call(): 779.

   * *note PyVectorcall_NARGS(): 778.

   * ‘PyWeakReference’

   * *note PyWeakref_GetObject(): 3dd.

   * *note PyWeakref_GetRef(): 3df.

   * *note PyWeakref_NewProxy(): 50f5.

   * *note PyWeakref_NewRef(): 1bce.

   * *note PyWrapperDescr_Type: 50f6.

   * *note PyWrapper_New(): 50f7.

   * *note PyZip_Type: 50f8.

   * *note Py_ASNATIVEBYTES_ALLOW_INDEX: 50f9.

   * *note Py_ASNATIVEBYTES_BIG_ENDIAN: 50fa.

   * *note Py_ASNATIVEBYTES_DEFAULTS: 50fb.

   * *note Py_ASNATIVEBYTES_LITTLE_ENDIAN: 50fc.

   * *note Py_ASNATIVEBYTES_NATIVE_ENDIAN: 50fd.

   * *note Py_ASNATIVEBYTES_REJECT_NEGATIVE: 50fe.

   * *note Py_ASNATIVEBYTES_UNSIGNED_BUFFER: 50ff.

   * *note Py_AUDIT_READ: 7b0.

   * *note Py_AddPendingCall(): b7a.

   * *note Py_AtExit(): 5100.

   * *note Py_BEGIN_ALLOW_THREADS: 4ea6.

   * *note Py_BLOCK_THREADS: 5101.

   * *note Py_BuildValue(): 3c2.

   * *note Py_BytesMain(): bba.

   * *note Py_CompileString(): a87.

   * *note Py_DecRef(): 5102.

   * *note Py_DecodeLocale(): dc2.

   * *note Py_END_ALLOW_THREADS: c81.

   * *note Py_EncodeLocale(): dc3.

   * *note Py_EndInterpreter(): 182d.

   * *note Py_EnterRecursiveCall(): 3d2.

   * *note Py_Exit(): f4d.

   * *note Py_FatalError(): b7c.

   * ‘Py_FileSystemDefaultEncodeErrors’

   * ‘Py_FileSystemDefaultEncoding’

   * *note Py_Finalize(): 45f.

   * *note Py_FinalizeEx(): f13.

   * *note Py_GenericAlias(): 5103.

   * *note Py_GenericAliasType: 5104.

   * *note Py_GetBuildInfo(): 1639.

   * *note Py_GetCompiler(): 5105.

   * *note Py_GetConstant(): 5f9.

   * *note Py_GetConstantBorrowed(): 5fa.

   * *note Py_GetCopyright(): 5106.

   * *note Py_GetExecPrefix(): 3e9.

   * *note Py_GetPath(): 3e3.

   * *note Py_GetPlatform(): 5107.

   * *note Py_GetPrefix(): 3e5.

   * *note Py_GetProgramFullPath(): 3ec.

   * *note Py_GetProgramName(): 3ee.

   * *note Py_GetPythonHome(): 3ef.

   * *note Py_GetRecursionLimit(): 5108.

   * *note Py_GetVersion(): 5109.

   * ‘Py_HasFileSystemDefaultEncoding’

   * *note Py_IncRef(): 510a.

   * *note Py_Initialize(): 460.

   * *note Py_InitializeEx(): 510b.

   * *note Py_Is(): aa2.

   * *note Py_IsFalse(): aa5.

   * *note Py_IsFinalizing(): 5fd.

   * *note Py_IsInitialized(): 4f29.

   * *note Py_IsNone(): aa3.

   * *note Py_IsTrue(): aa4.

   * *note Py_LeaveRecursiveCall(): b6d.

   * *note Py_Main(): e20.

   * *note Py_MakePendingCalls(): 510c.

   * *note Py_NewInterpreter(): 1b19.

   * *note Py_NewRef(): a9c.

   * *note Py_PACK_FULL_VERSION(): 380.

   * *note Py_PACK_VERSION(): 37f.

   * *note Py_READONLY: 7af.

   * *note Py_REFCNT(): 2cf.

   * *note Py_RELATIVE_OFFSET: 771.

   * *note Py_ReprEnter(): 510d.

   * *note Py_ReprLeave(): 510e.

   * *note Py_SetProgramName(): 199e.

   * *note Py_SetPythonHome(): 199d.

   * *note Py_SetRecursionLimit(): 510f.

   * *note Py_TPFLAGS_BASETYPE: 4ebe.

   * *note Py_TPFLAGS_DEFAULT: 4eb3.

   * *note Py_TPFLAGS_HAVE_GC: 982.

   * *note Py_TPFLAGS_HAVE_VECTORCALL: 777.

   * *note Py_TPFLAGS_ITEMS_AT_END: 76e.

   * *note Py_TPFLAGS_METHOD_DESCRIPTOR: 5110.

   * *note Py_TP_USE_SPEC: 5111.

   * *note Py_TYPE(): 3c9.

   * *note Py_T_BOOL: 5112.

   * *note Py_T_BYTE: 5113.

   * *note Py_T_CHAR: 5114.

   * *note Py_T_DOUBLE: 7ae.

   * *note Py_T_FLOAT: 5115.

   * *note Py_T_INT: 7ad.

   * *note Py_T_LONG: 5116.

   * *note Py_T_LONGLONG: 5117.

   * *note Py_T_OBJECT_EX: 7b2.

   * *note Py_T_PYSSIZET: 5118.

   * *note Py_T_SHORT: 5119.

   * *note Py_T_STRING: 511a.

   * *note Py_T_STRING_INPLACE: 511b.

   * *note Py_T_UBYTE: 511c.

   * *note Py_T_UINT: 511d.

   * *note Py_T_ULONG: 511e.

   * *note Py_T_ULONGLONG: 511f.

   * *note Py_T_USHORT: 5120.

   * *note Py_UCS4: 33d.

   * *note Py_UNBLOCK_THREADS: 5121.

   * ‘Py_UTF8Mode’

   * *note Py_VaBuildValue(): 5122.

   * *note Py_Version: 381.

   * *note Py_XNewRef(): a9d.

   * *note Py_am_aiter: 5123.

   * *note Py_am_anext: 5124.

   * *note Py_am_await: 5125.

   * *note Py_am_send: 5126.

   * *note Py_bf_getbuffer: 5127.

   * *note Py_bf_releasebuffer: 5128.

   * *note Py_buffer: 95d.

   * ‘Py_intptr_t’

   * *note Py_mod_create: 5129.

   * *note Py_mod_exec: b77.

   * *note Py_mod_gil: 483.

   * *note Py_mod_multiple_interpreters: 512a.

   * *note Py_mp_ass_subscript: 512b.

   * *note Py_mp_length: 512c.

   * *note Py_mp_subscript: 512d.

   * *note Py_nb_absolute: 512e.

   * *note Py_nb_add: 512f.

   * *note Py_nb_and: 5130.

   * *note Py_nb_bool: 5131.

   * *note Py_nb_divmod: 5132.

   * *note Py_nb_float: 5133.

   * *note Py_nb_floor_divide: 5134.

   * *note Py_nb_index: 5135.

   * *note Py_nb_inplace_add: 5136.

   * *note Py_nb_inplace_and: 5137.

   * *note Py_nb_inplace_floor_divide: 5138.

   * *note Py_nb_inplace_lshift: 5139.

   * *note Py_nb_inplace_matrix_multiply: 513a.

   * *note Py_nb_inplace_multiply: 513b.

   * *note Py_nb_inplace_or: 513c.

   * *note Py_nb_inplace_power: 513d.

   * *note Py_nb_inplace_remainder: 513e.

   * *note Py_nb_inplace_rshift: 513f.

   * *note Py_nb_inplace_subtract: 5140.

   * *note Py_nb_inplace_true_divide: 5141.

   * *note Py_nb_inplace_xor: 5142.

   * *note Py_nb_int: 5143.

   * *note Py_nb_invert: 5144.

   * *note Py_nb_lshift: 5145.

   * *note Py_nb_matrix_multiply: 5146.

   * *note Py_nb_multiply: 5147.

   * *note Py_nb_negative: 5148.

   * *note Py_nb_or: 5149.

   * *note Py_nb_positive: 514a.

   * *note Py_nb_power: 514b.

   * *note Py_nb_remainder: 514c.

   * *note Py_nb_rshift: 514d.

   * *note Py_nb_subtract: 514e.

   * *note Py_nb_true_divide: 514f.

   * *note Py_nb_xor: 5150.

   * *note Py_sq_ass_item: 5151.

   * *note Py_sq_concat: 5152.

   * *note Py_sq_contains: 5153.

   * *note Py_sq_inplace_concat: 5154.

   * *note Py_sq_inplace_repeat: 5155.

   * *note Py_sq_item: 5156.

   * *note Py_sq_length: 5157.

   * *note Py_sq_repeat: 5158.

   * *note Py_ssize_t: c57.

   * *note Py_tp_alloc: 5159.

   * *note Py_tp_base: 515a.

   * *note Py_tp_bases: 515b.

   * *note Py_tp_call: 515c.

   * *note Py_tp_clear: 515d.

   * *note Py_tp_dealloc: 515e.

   * *note Py_tp_del: 515f.

   * *note Py_tp_descr_get: 5160.

   * *note Py_tp_descr_set: 5161.

   * *note Py_tp_doc: 5162.

   * *note Py_tp_finalize: 5163.

   * *note Py_tp_free: 5164.

   * *note Py_tp_getattr: 5165.

   * *note Py_tp_getattro: 5166.

   * *note Py_tp_getset: 5167.

   * *note Py_tp_hash: 5168.

   * *note Py_tp_init: 5169.

   * *note Py_tp_is_gc: 516a.

   * *note Py_tp_iter: 516b.

   * *note Py_tp_iternext: 516c.

   * *note Py_tp_members: 516d.

   * *note Py_tp_methods: 516e.

   * *note Py_tp_new: 516f.

   * *note Py_tp_repr: 5170.

   * *note Py_tp_richcompare: 5171.

   * *note Py_tp_setattr: 5172.

   * *note Py_tp_setattro: 5173.

   * *note Py_tp_str: 5174.

   * *note Py_tp_token: 3b1.

   * *note Py_tp_traverse: 5175.

   * *note Py_tp_vectorcall: 5176.

   * ‘Py_uintptr_t’

   * *note allocfunc: 5177.

   * *note binaryfunc: 5178.

   * *note descrgetfunc: 5179.

   * *note descrsetfunc: 517a.

   * *note destructor: 517b.

   * *note getattrfunc: 517c.

   * *note getattrofunc: 517d.

   * *note getbufferproc: 517e.

   * *note getiterfunc: 517f.

   * *note getter: 5180.

   * *note hashfunc: 5181.

   * *note initproc: 5182.

   * *note inquiry: 5183.

   * *note iternextfunc: 5184.

   * *note lenfunc: 5185.

   * *note newfunc: 5186.

   * *note objobjargproc: 5187.

   * *note objobjproc: 5188.

   * *note releasebufferproc: 5189.

   * *note reprfunc: 518a.

   * *note richcmpfunc: 518b.

   * *note setattrfunc: 518c.

   * *note setattrofunc: 518d.

   * *note setter: 518e.

   * *note ssizeargfunc: 518f.

   * *note ssizeobjargproc: 5190.

   * ‘ssizessizeargfunc’

   * ‘ssizessizeobjargproc’

   * ‘symtable’

   * *note ternaryfunc: 5191.

   * *note traverseproc: 5192.

   * *note unaryfunc: 5193.

   * *note vectorcallfunc: 77a.

   * *note visitproc: 5194.


File: python.info,  Node: The Very High Level Layer,  Next: Reference Counting,  Prev: C API Stability,  Up: Python/C API Reference Manual

7.3 The Very High Level Layer
=============================

The functions in this chapter will let you execute Python source code
given in a file or a buffer, but they will not let you interact in a
more detailed way with the interpreter.

Several of these functions accept a start symbol from the grammar as a
parameter.  The available start symbols are *note Py_eval_input: 5199,
*note Py_file_input: 519a, *note Py_single_input: 519b, and *note
Py_func_type_input: 519c.  These are described following the functions
which accept them as parameters.

Note also that several of these functions take FILE* parameters.  One
particular issue which needs to be handled carefully is that the ‘FILE’
structure for different C libraries can be different and incompatible.
Under Windows (at least), it is possible for dynamically linked
extensions to actually use different libraries, so care should be taken
that FILE* parameters are only passed to these functions if it is
certain that they were created by the same library that the Python
runtime is using.

 -- C Funzione: int PyRun_AnyFile (FILE *fp, const char *filename)

     This is a simplified interface to *note PyRun_AnyFileExFlags():
     519e. below, leaving 'closeit' set to ‘0’ and 'flags' set to
     ‘NULL’.

 -- C Funzione: int PyRun_AnyFileFlags (FILE *fp, const char *filename,
          PyCompilerFlags *flags)

     This is a simplified interface to *note PyRun_AnyFileExFlags():
     519e. below, leaving the 'closeit' argument set to ‘0’.

 -- C Funzione: int PyRun_AnyFileEx (FILE *fp, const char *filename, int
          closeit)

     This is a simplified interface to *note PyRun_AnyFileExFlags():
     519e. below, leaving the 'flags' argument set to ‘NULL’.

 -- C Funzione: int PyRun_AnyFileExFlags (FILE *fp, const char
          *filename, int closeit, PyCompilerFlags *flags)

     If 'fp' refers to a file associated with an interactive device
     (console or terminal input or Unix pseudo-terminal), return the
     value of *note PyRun_InteractiveLoop(): 51a1, otherwise return the
     result of *note PyRun_SimpleFile(): 4ef5.  'filename' is decoded
     from the filesystem encoding (*note sys.getfilesystemencoding():
     e55.).  If 'filename' is ‘NULL’, this function uses ‘"???"’ as the
     filename.  If 'closeit' is true, the file is closed before
     ‘PyRun_SimpleFileExFlags()’ returns.

 -- C Funzione: int PyRun_SimpleString (const char *command)

     This is a simplified interface to *note PyRun_SimpleStringFlags():
     51a2. below, leaving the *note PyCompilerFlags: c9a.* argument set
     to ‘NULL’.

 -- C Funzione: int PyRun_SimpleStringFlags (const char *command,
          PyCompilerFlags *flags)

     Executes the Python source code from 'command' in the *note
     __main__: 1. module according to the 'flags' argument.  If *note
     __main__: 1. does not already exist, it is created.  Returns ‘0’ on
     success or ‘-1’ if an exception was raised.  If there was an error,
     there is no way to get the exception information.  For the meaning
     of 'flags', see below.

     Note that if an otherwise unhandled *note SystemExit: f3e. is
     raised, this function will not return ‘-1’, but exit the process,
     as long as *note PyConfig.inspect: 401. is zero.

 -- C Funzione: int PyRun_SimpleFile (FILE *fp, const char *filename)

     This is a simplified interface to *note PyRun_SimpleFileExFlags():
     1cb2. below, leaving 'closeit' set to ‘0’ and 'flags' set to
     ‘NULL’.

 -- C Funzione: int PyRun_SimpleFileEx (FILE *fp, const char *filename,
          int closeit)

     This is a simplified interface to *note PyRun_SimpleFileExFlags():
     1cb2. below, leaving 'flags' set to ‘NULL’.

 -- C Funzione: int PyRun_SimpleFileExFlags (FILE *fp, const char
          *filename, int closeit, PyCompilerFlags *flags)

     Similar to *note PyRun_SimpleStringFlags(): 51a2, but the Python
     source code is read from 'fp' instead of an in-memory string.
     'filename' should be the name of the file, it is decoded from *note
     filesystem encoding and error handler: 75e.  If 'closeit' is true,
     the file is closed before ‘PyRun_SimpleFileExFlags()’ returns.

          Nota: On Windows, 'fp' should be opened as binary mode (e.g.
          ‘fopen(filename, "rb")’).  Otherwise, Python may not handle
          script file with LF line ending correctly.

 -- C Funzione: int PyRun_InteractiveOneObject (FILE *fp, PyObject
          *filename, PyCompilerFlags *flags)

     Read and execute a single statement from a file associated with an
     interactive device according to the 'flags' argument.  The user
     will be prompted using ‘sys.ps1’ and ‘sys.ps2’.  'filename' must be
     a Python *note str: 169. object.

     Returns ‘0’ when the input was executed successfully, ‘-1’ if there
     was an exception, or an error code from the ‘errcode.h’ include
     file distributed as part of Python if there was a parse error.
     (Note that ‘errcode.h’ is not included by ‘Python.h’, so must be
     included specifically if needed.)

 -- C Funzione: int PyRun_InteractiveOne (FILE *fp, const char
          *filename)

     This is a simplified interface to *note
     PyRun_InteractiveOneFlags(): 51a6. below, leaving 'flags' set to
     ‘NULL’.

 -- C Funzione: int PyRun_InteractiveOneFlags (FILE *fp, const char
          *filename, PyCompilerFlags *flags)

     Similar to *note PyRun_InteractiveOneObject(): 51a4, but 'filename'
     is a const char*, which is decoded from the *note filesystem
     encoding and error handler: 75e.

 -- C Funzione: int PyRun_InteractiveLoop (FILE *fp, const char
          *filename)

     This is a simplified interface to *note
     PyRun_InteractiveLoopFlags(): 51a7. below, leaving 'flags' set to
     ‘NULL’.

 -- C Funzione: int PyRun_InteractiveLoopFlags (FILE *fp, const char
          *filename, PyCompilerFlags *flags)

     Read and execute statements from a file associated with an
     interactive device until EOF is reached.  The user will be prompted
     using ‘sys.ps1’ and ‘sys.ps2’.  'filename' is decoded from the
     *note filesystem encoding and error handler: 75e.  Returns ‘0’ at
     EOF or a negative number upon failure.

 -- C Variabile: int (*PyOS_InputHook)(void)
     ' Parte del *note ABI Stabile: 776.'  Can be set to point to a
     function with the prototype ‘int func(void)’.  The function will be
     called when Python’s interpreter prompt is about to become idle and
     wait for user input from the terminal.  The return value is
     ignored.  Overriding this hook can be used to integrate the
     interpreter’s prompt with other event loops, as done in
     ‘Modules/_tkinter.c’ in the Python source code.

     Cambiato nella versione 3.12: This function is only called from the
     *note main interpreter: 163.

 -- C Variabile: char *(*PyOS_ReadlineFunctionPointer)(FILE*, FILE*,
          const char*)

     Can be set to point to a function with the prototype ‘char
     *func(FILE *stdin, FILE *stdout, char *prompt)’, overriding the
     default function used to read a single line of input at the
     interpreter’s prompt.  The function is expected to output the
     string 'prompt' if it’s not ‘NULL’, and then read a line of input
     from the provided standard input file, returning the resulting
     string.  For example, The *note readline: bf. module sets this hook
     to provide line-editing and tab-completion features.

     The result must be a string allocated by *note PyMem_RawMalloc():
     631. or *note PyMem_RawRealloc(): 633, or ‘NULL’ if an error
     occurred.

     Cambiato nella versione 3.4: The result must be allocated by *note
     PyMem_RawMalloc(): 631. or *note PyMem_RawRealloc(): 633, instead
     of being allocated by *note PyMem_Malloc(): e62. or *note
     PyMem_Realloc(): 1234.

     Cambiato nella versione 3.12: This function is only called from the
     *note main interpreter: 163.

 -- C Funzione: *note PyObject: 5df. *PyRun_String (const char *str, int
          start, PyObject *globals, PyObject *locals)
     'Valore di ritorno: Nuovo riferimento.'  This is a simplified
     interface to *note PyRun_StringFlags(): 51a8. below, leaving
     'flags' set to ‘NULL’.

 -- C Funzione: *note PyObject: 5df. *PyRun_StringFlags (const char
          *str, int start, PyObject *globals, PyObject *locals,
          PyCompilerFlags *flags)
     'Valore di ritorno: Nuovo riferimento.'  Execute Python source code
     from 'str' in the context specified by the objects 'globals' and
     'locals' with the compiler flags specified by 'flags'.  'globals'
     must be a dictionary; 'locals' can be any object that implements
     the mapping protocol.  The parameter 'start' specifies the start
     symbol and must one of the *note available start symbols: 51a9.

     Returns the result of executing the code as a Python object, or
     ‘NULL’ if an exception was raised.

 -- C Funzione: *note PyObject: 5df. *PyRun_File (FILE *fp, const char
          *filename, int start, PyObject *globals, PyObject *locals)
     'Valore di ritorno: Nuovo riferimento.'  This is a simplified
     interface to *note PyRun_FileExFlags(): 51ab. below, leaving
     'closeit' set to ‘0’ and 'flags' set to ‘NULL’.

 -- C Funzione: *note PyObject: 5df. *PyRun_FileEx (FILE *fp, const char
          *filename, int start, PyObject *globals, PyObject *locals, int
          closeit)
     'Valore di ritorno: Nuovo riferimento.'  This is a simplified
     interface to *note PyRun_FileExFlags(): 51ab. below, leaving
     'flags' set to ‘NULL’.

 -- C Funzione: *note PyObject: 5df. *PyRun_FileFlags (FILE *fp, const
          char *filename, int start, PyObject *globals, PyObject
          *locals, PyCompilerFlags *flags)
     'Valore di ritorno: Nuovo riferimento.'  This is a simplified
     interface to *note PyRun_FileExFlags(): 51ab. below, leaving
     'closeit' set to ‘0’.

 -- C Funzione: *note PyObject: 5df. *PyRun_FileExFlags (FILE *fp, const
          char *filename, int start, PyObject *globals, PyObject
          *locals, int closeit, PyCompilerFlags *flags)
     'Valore di ritorno: Nuovo riferimento.'  Similar to *note
     PyRun_StringFlags(): 51a8, but the Python source code is read from
     'fp' instead of an in-memory string.  'filename' should be the name
     of the file, it is decoded from the *note filesystem encoding and
     error handler: 75e.  If 'closeit' is true, the file is closed
     before *note PyRun_FileExFlags(): 51ab. returns.

 -- C Funzione: *note PyObject: 5df. *Py_CompileString (const char *str,
          const char *filename, int start)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This is a simplified interface to *note
     Py_CompileStringFlags(): 51ae. below, leaving 'flags' set to
     ‘NULL’.

 -- C Funzione: *note PyObject: 5df. *Py_CompileStringFlags (const char
          *str, const char *filename, int start, PyCompilerFlags *flags)
     'Valore di ritorno: Nuovo riferimento.'  This is a simplified
     interface to *note Py_CompileStringExFlags(): 51af. below, with
     'optimize' set to ‘-1’.

 -- C Funzione: *note PyObject: 5df. *Py_CompileStringObject (const char
          *str, PyObject *filename, int start, PyCompilerFlags *flags,
          int optimize)
     'Valore di ritorno: Nuovo riferimento.'  Parse and compile the
     Python source code in 'str', returning the resulting code object.
     The start symbol is given by 'start'; this can be used to constrain
     the code which can be compiled and should be *note available start
     symbols: 51a9.  The filename specified by 'filename' is used to
     construct the code object and may appear in tracebacks or *note
     SyntaxError: 18e. exception messages.  This returns ‘NULL’ if the
     code cannot be parsed or compiled.

     The integer 'optimize' specifies the optimization level of the
     compiler; a value of ‘-1’ selects the optimization level of the
     interpreter as given by *note -O: 18c. options.  Explicit levels
     are ‘0’ (no optimization; ‘__debug__’ is true), ‘1’ (asserts are
     removed, ‘__debug__’ is false) or ‘2’ (docstrings are removed too).

     Added in version 3.4.

 -- C Funzione: *note PyObject: 5df. *Py_CompileStringExFlags (const
          char *str, const char *filename, int start, PyCompilerFlags
          *flags, int optimize)
     'Valore di ritorno: Nuovo riferimento.'  Like *note
     Py_CompileStringObject(): 51b0, but 'filename' is a byte string
     decoded from the *note filesystem encoding and error handler: 75e.

     Added in version 3.2.

 -- C Funzione: *note PyObject: 5df. *PyEval_EvalCode (PyObject *co,
          PyObject *globals, PyObject *locals)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This is a simplified interface to *note
     PyEval_EvalCodeEx(): 1ac2, with just the code object, and global
     and local variables.  The other arguments are set to ‘NULL’.

 -- C Funzione: *note PyObject: 5df. *PyEval_EvalCodeEx (PyObject *co,
          PyObject *globals, PyObject *locals, PyObject *const *args,
          int argcount, PyObject *const *kws, int kwcount, PyObject
          *const *defs, int defcount, PyObject *kwdefs, PyObject
          *closure)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Evaluate a precompiled code object, given a
     particular environment for its evaluation.  This environment
     consists of a dictionary of global variables, a mapping object of
     local variables, arrays of arguments, keywords and defaults, a
     dictionary of default values for *note keyword-only: 5a5. arguments
     and a closure tuple of cells.

 -- C Funzione: *note PyObject: 5df. *PyEval_EvalFrame (PyFrameObject
          *f)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Evaluate an execution frame.  This is a simplified
     interface to *note PyEval_EvalFrameEx(): 1230, for backward
     compatibility.

 -- C Funzione: *note PyObject: 5df. *PyEval_EvalFrameEx (PyFrameObject
          *f, int throwflag)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This is the main, unvarnished function of Python
     interpretation.  The code object associated with the execution
     frame 'f' is executed, interpreting bytecode and executing calls as
     needed.  The additional 'throwflag' parameter can mostly be ignored
     - if true, then it causes an exception to immediately be thrown;
     this is used for the *note throw(): 71d. methods of generator
     objects.

     Cambiato nella versione 3.4: This function now includes a debug
     assertion to help ensure that it does not silently discard an
     active exception.

 -- C Funzione: int PyEval_MergeCompilerFlags (PyCompilerFlags *cf)

     This function changes the flags of the current evaluation frame,
     and returns true on success, false on failure.

 -- C Struct: struct PyCompilerFlags

     This is the structure used to hold compiler flags.  In cases where
     code is only being compiled, it is passed as ‘int flags’, and in
     cases where code is being executed, it is passed as
     ‘PyCompilerFlags *flags’.  In this case, ‘from __future__ import’
     can modify 'flags'.

     Whenever ‘PyCompilerFlags *flags’ is ‘NULL’, *note cf_flags: 51b2.
     is treated as equal to ‘0’, and any modification due to ‘from
     __future__ import’ is discarded.

      -- C Membro: int cf_flags

          Compiler flags.

      -- C Membro: int cf_feature_version

          'cf_feature_version' is the minor Python version.  It should
          be initialized to ‘PY_MINOR_VERSION’.

          The field is ignored by default, it is used if and only if
          ‘PyCF_ONLY_AST’ flag is set in *note cf_flags: 51b2.

     Cambiato nella versione 3.8: Added 'cf_feature_version' field.

     The available compiler flags are accessible as macros:

      -- C Macro: PyCF_ALLOW_TOP_LEVEL_AWAIT
      -- C Macro: PyCF_ONLY_AST
      -- C Macro: PyCF_OPTIMIZED_AST
      -- C Macro: PyCF_TYPE_COMMENTS

          See *note compiler flags: 25a3. in documentation of the ‘ast’
          Python module, which exports these constants under the same
          names.

     The «‘PyCF’» flags above can be combined with «‘CO_FUTURE’» flags
     such as *note CO_FUTURE_ANNOTATIONS: 51b8. to enable features
     normally selectable using *note future statements: 45d.  See *note
     Code Object Flags: 51b9. for a complete list.

* Menu:

* Available start symbols::
* Stack Effects::


File: python.info,  Node: Available start symbols,  Next: Stack Effects,  Up: The Very High Level Layer

7.3.1 Available start symbols
-----------------------------

 -- C Variabile: int Py_eval_input

     The start symbol from the Python grammar for isolated expressions;
     for use with *note Py_CompileString(): a87.

 -- C Variabile: int Py_file_input

     The start symbol from the Python grammar for sequences of
     statements as read from a file or other source; for use with *note
     Py_CompileString(): a87.  This is the symbol to use when compiling
     arbitrarily long Python source code.

 -- C Variabile: int Py_single_input

     The start symbol from the Python grammar for a single statement;
     for use with *note Py_CompileString(): a87.  This is the symbol
     used for the interactive interpreter loop.

 -- C Variabile: int Py_func_type_input

     The start symbol from the Python grammar for a function type; for
     use with *note Py_CompileString(): a87.  This is used to parse
     «signature type comments» from PEP 484(1).

     This requires the *note PyCF_ONLY_AST: 51b5. flag to be set.

     Vedi anche
     ..........

        * *note ast.FunctionType: 4b67.

        * PEP 484(2)

     Added in version 3.8.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0484/


File: python.info,  Node: Stack Effects,  Prev: Available start symbols,  Up: The Very High Level Layer

7.3.2 Stack Effects
-------------------

Vedi anche
..........

*note dis.stack_effect(): 1133.

 -- C Macro: PY_INVALID_STACK_EFFECT

     Sentinel value representing an invalid stack effect.

     This is currently equivalent to ‘INT_MAX’.

     Added in version 3.8.

 -- C Funzione: int PyCompile_OpcodeStackEffect (int opcode, int oparg)

     Compute the stack effect of 'opcode' with argument 'oparg'.

     On success, this function returns the stack effect; on failure,
     this returns *note PY_INVALID_STACK_EFFECT: 51bc.

     Added in version 3.4.

 -- C Funzione: int PyCompile_OpcodeStackEffectWithJump (int opcode, int
          oparg, int jump)

     Similar to *note PyCompile_OpcodeStackEffect(): 51bd, but don’t
     include the stack effect of jumping if 'jump' is zero.

     If 'jump' is ‘0’, this will not include the stack effect of
     jumping, but if 'jump' is ‘1’ or ‘-1’, this will include it.

     On success, this function returns the stack effect; on failure,
     this returns *note PY_INVALID_STACK_EFFECT: 51bc.

     Added in version 3.8.


File: python.info,  Node: Reference Counting,  Next: Exception Handling,  Prev: The Very High Level Layer,  Up: Python/C API Reference Manual

7.4 Reference Counting
======================

The functions and macros in this section are used for managing reference
counts of Python objects.

 -- C Funzione: *note Py_ssize_t: c57. Py_REFCNT (PyObject *o)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Get the
     reference count of the Python object 'o'.

     Note that the returned value may not actually reflect how many
     references to the object are actually held.  For example, some
     objects are *note immortal: 290. and have a very high refcount that
     does not reflect the actual number of references.  Consequently, do
     not rely on the returned value to be accurate, other than a value
     of 0 or 1.

     Use the *note Py_SET_REFCNT(): aaa. function to set an object
     reference count.

          Nota: On *note free threaded: 1f4. builds of Python, returning
          1 isn’t sufficient to determine if it’s safe to treat 'o' as
          having no access by other threads.  Use *note
          PyUnstable_Object_IsUniquelyReferenced(): 3c6. for that
          instead.

          See also the function *note
          PyUnstable_Object_IsUniqueReferencedTemporary(): 3c7.

     Cambiato nella versione 3.10: *note Py_REFCNT(): 2cf. is changed to
     the inline static function.

     Cambiato nella versione 3.11: The parameter type is no longer const
     *note PyObject: 5df.*.

 -- C Funzione: void Py_SET_REFCNT (PyObject *o, Py_ssize_t refcnt)

     Set the object 'o' reference counter to 'refcnt'.

     On *note Python build with Free Threading: 2157, if 'refcnt' is
     larger than ‘UINT32_MAX’, the object is made *note immortal: 290.

     This function has no effect on *note immortal: 290. objects.

     Added in version 3.9.

     Cambiato nella versione 3.12: Immortal objects are not modified.

 -- C Funzione: void Py_INCREF (PyObject *o)

     Indicate taking a new *note strong reference: 5e2. to object 'o',
     indicating it is in use and should not be destroyed.

     This function has no effect on *note immortal: 290. objects.

     This function is usually used to convert a *note borrowed
     reference: 3d7. to a *note strong reference: 5e2. in-place.  The
     *note Py_NewRef(): a9c. function can be used to create a new *note
     strong reference: 5e2.

     When done using the object, release is by calling *note
     Py_DECREF(): 791.

     The object must not be ‘NULL’; if you aren’t sure that it isn’t
     ‘NULL’, use *note Py_XINCREF(): c5c.

     Do not expect this function to actually modify 'o' in any way.  For
     at least some objects(1), this function has no effect.

     Cambiato nella versione 3.12: Immortal objects are not modified.

 -- C Funzione: void Py_XINCREF (PyObject *o)

     Similar to *note Py_INCREF(): 790, but the object 'o' can be
     ‘NULL’, in which case this has no effect.

     See also *note Py_XNewRef(): a9d.

 -- C Funzione: *note PyObject: 5df. *Py_NewRef (PyObject *o)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Create a
     new *note strong reference: 5e2. to an object: call *note
     Py_INCREF(): 790. on 'o' and return the object 'o'.

     When the *note strong reference: 5e2. is no longer needed, *note
     Py_DECREF(): 791. should be called on it to release the reference.

     The object 'o' must not be ‘NULL’; use *note Py_XNewRef(): a9d. if
     'o' can be ‘NULL’.

     For example:

          Py_INCREF(obj);
          self->attr = obj;

     can be written as:

          self->attr = Py_NewRef(obj);

     See also *note Py_INCREF(): 790.

     Added in version 3.10.

 -- C Funzione: *note PyObject: 5df. *Py_XNewRef (PyObject *o)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Similar
     to *note Py_NewRef(): a9c, but the object 'o' can be NULL.

     If the object 'o' is ‘NULL’, the function just returns ‘NULL’.

     Added in version 3.10.

 -- C Funzione: void Py_DECREF (PyObject *o)

     Release a *note strong reference: 5e2. to object 'o', indicating
     the reference is no longer used.

     This function has no effect on *note immortal: 290. objects.

     Once the last *note strong reference: 5e2. is released (i.e.  the
     object’s reference count reaches 0), the object’s type’s
     deallocation function (which must not be ‘NULL’) is invoked.

     This function is usually used to delete a *note strong reference:
     5e2. before exiting its scope.

     The object must not be ‘NULL’; if you aren’t sure that it isn’t
     ‘NULL’, use *note Py_XDECREF(): 993.

     Do not expect this function to actually modify 'o' in any way.  For
     at least some objects(2), this function has no effect.

          Avvertimento: The deallocation function can cause arbitrary
          Python code to be invoked (e.g.  when a class instance with a
          *note __del__(): 11ff. method is deallocated).  While
          exceptions in such code are not propagated, the executed code
          has free access to all Python global variables.  This means
          that any object that is reachable from a global variable
          should be in a consistent state before *note Py_DECREF(): 791.
          is invoked.  For example, code to delete an object from a list
          should copy a reference to the deleted object in a temporary
          variable, update the list data structure, and then call *note
          Py_DECREF(): 791. for the temporary variable.

     Cambiato nella versione 3.12: Immortal objects are not modified.

 -- C Funzione: void Py_XDECREF (PyObject *o)

     Similar to *note Py_DECREF(): 791, but the object 'o' can be
     ‘NULL’, in which case this has no effect.  The same warning from
     *note Py_DECREF(): 791. applies here as well.

 -- C Funzione: void Py_CLEAR (PyObject *o)

     Release a *note strong reference: 5e2. for object 'o'.  The object
     may be ‘NULL’, in which case the macro has no effect; otherwise the
     effect is the same as for *note Py_DECREF(): 791, except that the
     argument is also set to ‘NULL’.  The warning for *note Py_DECREF():
     791. does not apply with respect to the object passed because the
     macro carefully uses a temporary variable and sets the argument to
     ‘NULL’ before releasing the reference.

     It is a good idea to use this macro whenever releasing a reference
     to an object that might be traversed during garbage collection.

     Cambiato nella versione 3.12: The macro argument is now only
     evaluated once.  If the argument has side effects, these are no
     longer duplicated.

 -- C Funzione: void Py_IncRef (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Indicate taking a new *note
     strong reference: 5e2. to object 'o'.  A function version of *note
     Py_XINCREF(): c5c.  It can be used for runtime dynamic embedding of
     Python.

 -- C Funzione: void Py_DecRef (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Release a *note strong
     reference: 5e2. to object 'o'.  A function version of *note
     Py_XDECREF(): 993.  It can be used for runtime dynamic embedding of
     Python.

 -- C Macro: Py_SETREF (dst, src)

     Macro safely releasing a *note strong reference: 5e2. to object
     'dst' and setting 'dst' to 'src'.

     As in case of *note Py_CLEAR(): 799, «the obvious» code can be
     deadly:

          Py_DECREF(dst);
          dst = src;

     The safe way is:

          Py_SETREF(dst, src);

     That arranges to set 'dst' to 'src' 'before' releasing the
     reference to the old value of 'dst', so that any code triggered as
     a side-effect of 'dst' getting torn down no longer believes 'dst'
     points to a valid object.

     Added in version 3.6.

     Cambiato nella versione 3.12: The macro arguments are now only
     evaluated once.  If an argument has side effects, these are no
     longer duplicated.

 -- C Macro: Py_XSETREF (dst, src)

     Variant of *note Py_SETREF: 79a. macro that uses *note
     Py_XDECREF(): 993. instead of *note Py_DECREF(): 791.

     Added in version 3.6.

     Cambiato nella versione 3.12: The macro arguments are now only
     evaluated once.  If an argument has side effects, these are no
     longer duplicated.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0683/

   (2) https://peps.python.org/pep-0683/


File: python.info,  Node: Exception Handling,  Next: Defining extension modules,  Prev: Reference Counting,  Up: Python/C API Reference Manual

7.5 Exception Handling
======================

The functions described in this chapter will let you handle and raise
Python exceptions.  It is important to understand some of the basics of
Python exception handling.  It works somewhat like the POSIX ‘errno’
variable: there is a global indicator (per thread) of the last error
that occurred.  Most C API functions don’t clear this on success, but
will set it to indicate the cause of the error on failure.  Most C API
functions also return an error indicator, usually ‘NULL’ if they are
supposed to return a pointer, or ‘-1’ if they return an integer
(exception: the ‘PyArg_*’ functions return ‘1’ for success and ‘0’ for
failure).

Concretely, the error indicator consists of three object pointers: the
exception’s type, the exception’s value, and the traceback object.  Any
of those pointers can be ‘NULL’ if non-set (although some combinations
are forbidden, for example you can’t have a non-‘NULL’ traceback if the
exception type is ‘NULL’).

When a function must fail because some function it called failed, it
generally doesn’t set the error indicator; the function it called
already set it.  It is responsible for either handling the error and
clearing the exception or returning after cleaning up any resources it
holds (such as object references or memory allocations); it should 'not'
continue normally if it is not prepared to handle the error.  If
returning due to an error, it is important to indicate to the caller
that an error has been set.  If the error is not handled or carefully
propagated, additional calls into the Python/C API may not behave as
intended and may fail in mysterious ways.

     Nota: The error indicator is 'not' the result of *note
     sys.exc_info(): 89b.  The former corresponds to an exception that
     is not yet caught (and is therefore still propagating), while the
     latter returns an exception after it is caught (and has therefore
     stopped propagating).

* Menu:

* Printing and clearing::
* Raising exceptions::
* Issuing warnings::
* Querying the error indicator::
* Signal Handling: Signal Handling<2>.
* Exception Classes::
* Exception Objects::
* Unicode Exception Objects::
* Recursion Control::
* Exception and warning types::
* Tracebacks::


File: python.info,  Node: Printing and clearing,  Next: Raising exceptions,  Up: Exception Handling

7.5.1 Printing and clearing
---------------------------

 -- C Funzione: void PyErr_Clear ()
     ' Parte del *note ABI Stabile: 776.'  Clear the error indicator.
     If the error indicator is not set, there is no effect.

 -- C Funzione: void PyErr_PrintEx (int set_sys_last_vars)
     ' Parte del *note ABI Stabile: 776.'  Print a standard traceback to
     ‘sys.stderr’ and clear the error indicator.  'Unless' the error is
     a ‘SystemExit’, in that case no traceback is printed and the Python
     process will exit with the error code specified by the ‘SystemExit’
     instance.

     Call this function 'only' when the error indicator is set.
     Otherwise it will cause a fatal error!

     If 'set_sys_last_vars' is nonzero, the variable *note sys.last_exc:
     6e6. is set to the printed exception.  For backwards compatibility,
     the deprecated variables *note sys.last_type: 6e7, *note
     sys.last_value: 6e8. and *note sys.last_traceback: 6e9. are also
     set to the type, value and traceback of this exception,
     respectively.

     Cambiato nella versione 3.12: The setting of *note sys.last_exc:
     6e6. was added.

 -- C Funzione: void PyErr_Print ()
     ' Parte del *note ABI Stabile: 776.'  Alias for ‘PyErr_PrintEx(1)’.

 -- C Funzione: void PyErr_WriteUnraisable (PyObject *obj)
     ' Parte del *note ABI Stabile: 776.'  Call *note
     sys.unraisablehook(): 508. using the current exception and 'obj'
     argument.

     This utility function prints a warning message to ‘sys.stderr’ when
     an exception has been set but it is impossible for the interpreter
     to actually raise the exception.  It is used, for example, when an
     exception occurs in an *note __del__(): 11ff. method.

     The function is called with a single argument 'obj' that identifies
     the context in which the unraisable exception occurred.  If
     possible, the repr of 'obj' will be printed in the warning message.
     If 'obj' is ‘NULL’, only the traceback is printed.

     An exception must be set when calling this function.

     Cambiato nella versione 3.4: Print a traceback.  Print only
     traceback if 'obj' is ‘NULL’.

     Cambiato nella versione 3.8: Use *note sys.unraisablehook(): 508.

 -- C Funzione: void PyErr_FormatUnraisable (const char *format, ...)

     Similar to *note PyErr_WriteUnraisable(): 5f2, but the 'format' and
     subsequent parameters help format the warning message; they have
     the same meaning and values as in *note PyUnicode_FromFormat():
     62b.  ‘PyErr_WriteUnraisable(obj)’ is roughly equivalent to
     ‘PyErr_FormatUnraisable("Exception ignored in: %R", obj)’.  If
     'format' is ‘NULL’, only the traceback is printed.

     Added in version 3.13.

 -- C Funzione: void PyErr_DisplayException (PyObject *exc)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Print
     the standard traceback display of ‘exc’ to ‘sys.stderr’, including
     chained exceptions and notes.

     Added in version 3.12.


File: python.info,  Node: Raising exceptions,  Next: Issuing warnings,  Prev: Printing and clearing,  Up: Exception Handling

7.5.2 Raising exceptions
------------------------

These functions help you set the current thread’s error indicator.  For
convenience, some of these functions will always return a ‘NULL’ pointer
for use in a ‘return’ statement.

 -- C Funzione: void PyErr_SetString (PyObject *type, const char
          *message)
     ' Parte del *note ABI Stabile: 776.'  This is the most common way
     to set the error indicator.  The first argument specifies the
     exception type; it is normally one of the standard exceptions, e.g.
     *note PyExc_RuntimeError: 4fe4.  You need not create a new *note
     strong reference: 5e2. to it (e.g.  with *note Py_INCREF(): 790.).
     The second argument is an error message; it is decoded from
     ‘'utf-8'’.

 -- C Funzione: void PyErr_SetObject (PyObject *type, PyObject *value)
     ' Parte del *note ABI Stabile: 776.'  This function is similar to
     *note PyErr_SetString(): 79d. but lets you specify an arbitrary
     Python object for the «value» of the exception.

 -- C Funzione: *note PyObject: 5df. *PyErr_Format (PyObject *exception,
          const char *format, ...)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776.'  This function sets the error indicator and returns ‘NULL’.
     'exception' should be a Python exception class.  The 'format' and
     subsequent parameters help format the error message; they have the
     same meaning and values as in *note PyUnicode_FromFormat(): 62b.
     'format' is an ASCII-encoded string.

 -- C Funzione: *note PyObject: 5df. *PyErr_FormatV (PyObject
          *exception, const char *format, va_list vargs)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776. dalla versione 3.5.'  Same as *note PyErr_Format(): 10b3, but
     taking a ‘va_list’ argument rather than a variable number of
     arguments.

     Added in version 3.5.

 -- C Funzione: void PyErr_SetNone (PyObject *type)
     ' Parte del *note ABI Stabile: 776.'  This is a shorthand for
     ‘PyErr_SetObject(type, Py_None)’.

 -- C Funzione: int PyErr_BadArgument ()
     ' Parte del *note ABI Stabile: 776.'  This is a shorthand for
     ‘PyErr_SetString(PyExc_TypeError, message)’, where 'message'
     indicates that a built-in operation was invoked with an illegal
     argument.  It is mostly for internal use.

 -- C Funzione: *note PyObject: 5df. *PyErr_NoMemory ()
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776.'  This is a shorthand for ‘PyErr_SetNone(PyExc_MemoryError)’;
     it returns ‘NULL’ so an object allocation function can write
     ‘return PyErr_NoMemory();’ when it runs out of memory.

 -- C Funzione: *note PyObject: 5df. *PyErr_SetFromErrno (PyObject
          *type)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776.'

     This is a convenience function to raise an exception when a C
     library function has returned an error and set the C variable
     ‘errno’.  It constructs a tuple object whose first item is the
     integer ‘errno’ value and whose second item is the corresponding
     error message (gotten from ‘strerror()’), and then calls
     ‘PyErr_SetObject(type, object)’.  On Unix, when the ‘errno’ value
     is ‘EINTR’, indicating an interrupted system call, this calls *note
     PyErr_CheckSignals(): 694, and if that set the error indicator,
     leaves it set to that.  The function always returns ‘NULL’, so a
     wrapper function around a system call can write ‘return
     PyErr_SetFromErrno(type);’ when the system call returns an error.

 -- C Funzione: *note PyObject: 5df.
          *PyErr_SetFromErrnoWithFilenameObject (PyObject *type,
          PyObject *filenameObject)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776.'  Similar to *note PyErr_SetFromErrno(): 4e81, with the
     additional behavior that if 'filenameObject' is not ‘NULL’, it is
     passed to the constructor of 'type' as a third parameter.  In the
     case of *note OSError: 2c0. exception, this is used to define the
     ‘filename’ attribute of the exception instance.

 -- C Funzione: *note PyObject: 5df.
          *PyErr_SetFromErrnoWithFilenameObjects (PyObject *type,
          PyObject *filenameObject, PyObject *filenameObject2)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776. dalla versione 3.7.'  Similar to *note
     PyErr_SetFromErrnoWithFilenameObject(): 4fab, but takes a second
     filename object, for raising errors when a function that takes two
     filenames fails.

     Added in version 3.4.

 -- C Funzione: *note PyObject: 5df. *PyErr_SetFromErrnoWithFilename
          (PyObject *type, const char *filename)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776.'  Similar to *note PyErr_SetFromErrnoWithFilenameObject():
     4fab, but the filename is given as a C string.  'filename' is
     decoded from the *note filesystem encoding and error handler: 75e.

 -- C Funzione: *note PyObject: 5df. *PyErr_SetFromWindowsErr (int ierr)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776. on Windows dalla versione 3.7.'  This is a convenience
     function to raise *note OSError: 2c0.  If called with 'ierr' of
     ‘0’, the error code returned by a call to ‘GetLastError()’ is used
     instead.  It calls the Win32 function ‘FormatMessage()’ to retrieve
     the Windows description of error code given by 'ierr' or
     ‘GetLastError()’, then it constructs a *note OSError: 2c0. object
     with the *note winerror: 26d2. attribute set to the error code, the
     *note strerror: 26d3. attribute set to the corresponding error
     message (gotten from ‘FormatMessage()’), and then calls
     ‘PyErr_SetObject(PyExc_OSError, object)’.  This function always
     returns ‘NULL’.

     *note Availability: 2128.: Windows.

 -- C Funzione: *note PyObject: 5df. *PyErr_SetExcFromWindowsErr
          (PyObject *type, int ierr)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776. on Windows dalla versione 3.7.'  Similar to *note
     PyErr_SetFromWindowsErr(): 4fad, with an additional parameter
     specifying the exception type to be raised.

     *note Availability: 2128.: Windows.

 -- C Funzione: *note PyObject: 5df.
          *PyErr_SetFromWindowsErrWithFilename (int ierr, const char
          *filename)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776. on Windows dalla versione 3.7.'  Similar to *note
     PyErr_SetFromWindowsErr(): 4fad, with the additional behavior that
     if 'filename' is not ‘NULL’, it is decoded from the filesystem
     encoding (*note os.fsdecode(): e50.) and passed to the constructor
     of *note OSError: 2c0. as a third parameter to be used to define
     the ‘filename’ attribute of the exception instance.

     *note Availability: 2128.: Windows.

 -- C Funzione: *note PyObject: 5df.
          *PyErr_SetExcFromWindowsErrWithFilenameObject (PyObject *type,
          int ierr, PyObject *filename)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776. on Windows dalla versione 3.7.'  Similar to *note
     PyErr_SetExcFromWindowsErr(): 4fa8, with the additional behavior
     that if 'filename' is not ‘NULL’, it is passed to the constructor
     of *note OSError: 2c0. as a third parameter to be used to define
     the ‘filename’ attribute of the exception instance.

     *note Availability: 2128.: Windows.

 -- C Funzione: *note PyObject: 5df.
          *PyErr_SetExcFromWindowsErrWithFilenameObjects (PyObject
          *type, int ierr, PyObject *filename, PyObject *filename2)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776. on Windows dalla versione 3.7.'  Similar to *note
     PyErr_SetExcFromWindowsErrWithFilenameObject(): 4fa9, but accepts a
     second filename object.

     *note Availability: 2128.: Windows.

     Added in version 3.4.

 -- C Funzione: *note PyObject: 5df.
          *PyErr_SetExcFromWindowsErrWithFilename (PyObject *type, int
          ierr, const char *filename)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776. on Windows dalla versione 3.7.'  Similar to *note
     PyErr_SetFromWindowsErrWithFilename(): 1a6f, with an additional
     parameter specifying the exception type to be raised.

     *note Availability: 2128.: Windows.

 -- C Funzione: *note PyObject: 5df. *PyErr_SetImportError (PyObject
          *msg, PyObject *name, PyObject *path)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776. dalla versione 3.7.'  This is a convenience function to raise
     *note ImportError: 65b.  'msg' will be set as the exception’s
     message string.  'name' and 'path', both of which can be ‘NULL’,
     will be set as the *note ImportError: 65b.’s respective ‘name’ and
     ‘path’ attributes.

     Added in version 3.3.

 -- C Funzione: *note PyObject: 5df. *PyErr_SetImportErrorSubclass
          (PyObject *exception, PyObject *msg, PyObject *name, PyObject
          *path)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776. dalla versione 3.6.'  Much like *note PyErr_SetImportError():
     f3b. but this function allows for specifying a subclass of *note
     ImportError: 65b. to raise.

     Added in version 3.6.

 -- C Funzione: void PyErr_SyntaxLocationObject (PyObject *filename, int
          lineno, int col_offset)

     Set file, line, and offset information for the current exception.
     If the current exception is not a *note SyntaxError: 18e, then it
     sets additional attributes, which make the exception printing
     subsystem think the exception is a *note SyntaxError: 18e.

     Added in version 3.4.

 -- C Funzione: void PyErr_RangedSyntaxLocationObject (PyObject
          *filename, int lineno, int col_offset, int end_lineno, int
          end_col_offset)

     Similar to *note PyErr_SyntaxLocationObject(): 51c7, but also sets
     the 'end_lineno' and 'end_col_offset' information for the current
     exception.

     Added in version 3.10.

 -- C Funzione: void PyErr_SyntaxLocationEx (const char *filename, int
          lineno, int col_offset)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Like
     *note PyErr_SyntaxLocationObject(): 51c7, but 'filename' is a byte
     string decoded from the *note filesystem encoding and error
     handler: 75e.

     Added in version 3.2.

 -- C Funzione: void PyErr_SyntaxLocation (const char *filename, int
          lineno)
     ' Parte del *note ABI Stabile: 776.'  Like *note
     PyErr_SyntaxLocationEx(): 4fb1, but the 'col_offset' parameter is
     omitted.

 -- C Funzione: void PyErr_BadInternalCall ()
     ' Parte del *note ABI Stabile: 776.'  This is a shorthand for
     ‘PyErr_SetString(PyExc_SystemError, message)’, where 'message'
     indicates that an internal operation (e.g.  a Python/C API
     function) was invoked with an illegal argument.  It is mostly for
     internal use.

 -- C Funzione: *note PyObject: 5df. *PyErr_ProgramTextObject (PyObject
          *filename, int lineno)

     Get the source line in 'filename' at line 'lineno'.  'filename'
     should be a Python *note str: 169. object.

     On success, this function returns a Python string object with the
     found line.  On failure, this function returns ‘NULL’ without an
     exception set.

 -- C Funzione: *note PyObject: 5df. *PyErr_ProgramText (const char
          *filename, int lineno)
     ' Parte del *note ABI Stabile: 776.'  Similar to *note
     PyErr_ProgramTextObject(): 51c9, but 'filename' is a const char*,
     which is decoded with the *note filesystem encoding and error
     handler: 75e, instead of a Python object reference.


File: python.info,  Node: Issuing warnings,  Next: Querying the error indicator,  Prev: Raising exceptions,  Up: Exception Handling

7.5.3 Issuing warnings
----------------------

Use these functions to issue warnings from C code.  They mirror similar
functions exported by the Python *note warnings: 118. module.  They
normally print a warning message to 'sys.stderr'; however, it is also
possible that the user has specified that warnings are to be turned into
errors, and in that case they will raise an exception.  It is also
possible that the functions raise an exception because of a problem with
the warning machinery.  The return value is ‘0’ if no exception is
raised, or ‘-1’ if an exception is raised.  (It is not possible to
determine whether a warning message is actually printed, nor what the
reason is for the exception; this is intentional.)  If an exception is
raised, the caller should do its normal exception handling (for example,
*note Py_DECREF(): 791. owned references and return an error value).

 -- C Funzione: int PyErr_WarnEx (PyObject *category, const char
          *message, Py_ssize_t stack_level)
     ' Parte del *note ABI Stabile: 776.'  Issue a warning message.  The
     'category' argument is a warning category (see below) or ‘NULL’;
     the 'message' argument is a UTF-8 encoded string.  'stack_level' is
     a positive number giving a number of stack frames; the warning will
     be issued from the currently executing line of code in that stack
     frame.  A 'stack_level' of 1 is the function calling *note
     PyErr_WarnEx(): 1653, 2 is the function above that, and so forth.

     Warning categories must be subclasses of *note PyExc_Warning:
     4ff5.; *note PyExc_Warning: 4ff5. is a subclass of *note
     PyExc_Exception: 4fc9.; the default warning category is *note
     PyExc_RuntimeWarning: 4fe5.  The standard Python warning categories
     are available as global variables whose names are enumerated at
     *note Warning types: 51cb.

     For information about warning control, see the documentation for
     the *note warnings: 118. module and the *note -W: ac7. option in
     the command line documentation.  There is no C API for warning
     control.

 -- C Funzione: int PyErr_WarnExplicitObject (PyObject *category,
          PyObject *message, PyObject *filename, int lineno, PyObject
          *module, PyObject *registry)

     Issue a warning message with explicit control over all warning
     attributes.  This is a straightforward wrapper around the Python
     function *note warnings.warn_explicit(): eff.; see there for more
     information.  The 'module' and 'registry' arguments may be set to
     ‘NULL’ to get the default effect described there.

     Added in version 3.4.

 -- C Funzione: int PyErr_WarnExplicit (PyObject *category, const char
          *message, const char *filename, int lineno, const char
          *module, PyObject *registry)
     ' Parte del *note ABI Stabile: 776.'  Similar to *note
     PyErr_WarnExplicitObject(): 51cc. except that 'message' and
     'module' are UTF-8 encoded strings, and 'filename' is decoded from
     the *note filesystem encoding and error handler: 75e.

 -- C Funzione: int PyErr_WarnFormat (PyObject *category, Py_ssize_t
          stack_level, const char *format, ...)
     ' Parte del *note ABI Stabile: 776.'  Function similar to *note
     PyErr_WarnEx(): 1653, but use *note PyUnicode_FromFormat(): 62b. to
     format the warning message.  'format' is an ASCII-encoded string.

     Added in version 3.2.

 -- C Funzione: int PyErr_WarnExplicitFormat (PyObject *category, const
          char *filename, int lineno, const char *module, PyObject
          *registry, const char *format, ...)

     Similar to *note PyErr_WarnExplicit(): 1a75, but uses *note
     PyUnicode_FromFormat(): 62b. to format the warning message.
     'format' is an ASCII-encoded string.

     Added in version 3.2.

 -- C Funzione: int PyErr_ResourceWarning (PyObject *source, Py_ssize_t
          stack_level, const char *format, ...)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.6.'  Function
     similar to *note PyErr_WarnFormat(): 4fb2, but 'category' is *note
     ResourceWarning: 54d. and it passes 'source' to
     ‘warnings.WarningMessage’.

     Added in version 3.6.


File: python.info,  Node: Querying the error indicator,  Next: Signal Handling<2>,  Prev: Issuing warnings,  Up: Exception Handling

7.5.4 Querying the error indicator
----------------------------------

 -- C Funzione: *note PyObject: 5df. *PyErr_Occurred ()
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Test whether the error indicator is set.
     If set, return the exception 'type' (the first argument to the last
     call to one of the ‘PyErr_Set*’ functions or to *note
     PyErr_Restore(): 42b.).  If not set, return ‘NULL’.  You do not own
     a reference to the return value, so you do not need to *note
     Py_DECREF(): 791. it.

     The caller must have an *note attached thread state: 4eba.

          Nota: Do not compare the return value to a specific exception;
          use *note PyErr_ExceptionMatches(): 4f26. instead, shown
          below.  (The comparison could easily fail since the exception
          may be an instance instead of a class, in the case of a class
          exception, or it may be a subclass of the expected exception.)

 -- C Funzione: int PyErr_ExceptionMatches (PyObject *exc)
     ' Parte del *note ABI Stabile: 776.'  Equivalent to
     ‘PyErr_GivenExceptionMatches(PyErr_Occurred(), exc)’.  This should
     only be called when an exception is actually set; a memory access
     violation will occur if no exception has been raised.

 -- C Funzione: int PyErr_GivenExceptionMatches (PyObject *given,
          PyObject *exc)
     ' Parte del *note ABI Stabile: 776.'  Return true if the 'given'
     exception matches the exception type in 'exc'.  If 'exc' is a class
     object, this also returns true when 'given' is an instance of a
     subclass.  If 'exc' is a tuple, all exception types in the tuple
     (and recursively in subtuples) are searched for a match.

 -- C Funzione: *note PyObject: 5df. *PyErr_GetRaisedException (void)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.12.'  Return the exception currently
     being raised, clearing the error indicator at the same time.
     Return ‘NULL’ if the error indicator is not set.

     This function is used by code that needs to catch exceptions, or
     code that needs to save and restore the error indicator
     temporarily.

     For example:

          {
             PyObject *exc = PyErr_GetRaisedException();

             /* ... code that might produce other errors ... */

             PyErr_SetRaisedException(exc);
          }

     Vedi anche
     ..........

     *note PyErr_GetHandledException(): 974, to save the exception
     currently being handled.

     Added in version 3.12.

 -- C Funzione: void PyErr_SetRaisedException (PyObject *exc)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Set
     'exc' as the exception currently being raised, clearing the
     existing exception if one is set.

          Avvertimento: This call steals a reference to 'exc', which
          must be a valid exception.

     Added in version 3.12.

 -- C Funzione: void PyErr_Fetch (PyObject **ptype, PyObject **pvalue,
          PyObject **ptraceback)
     ' Parte del *note ABI Stabile: 776.'

     Deprecato dalla versione 3.12: Use *note
     PyErr_GetRaisedException(): 429. instead.

     Retrieve the error indicator into three variables whose addresses
     are passed.  If the error indicator is not set, set all three
     variables to ‘NULL’.  If it is set, it will be cleared and you own
     a reference to each object retrieved.  The value and traceback
     object may be ‘NULL’ even when the type object is not.

          Nota: This function is normally only used by legacy code that
          needs to catch exceptions or save and restore the error
          indicator temporarily.

          For example:

               {
                  PyObject *type, *value, *traceback;
                  PyErr_Fetch(&type, &value, &traceback);

                  /* ... code that might produce other errors ... */

                  PyErr_Restore(type, value, traceback);
               }

 -- C Funzione: void PyErr_Restore (PyObject *type, PyObject *value,
          PyObject *traceback)
     ' Parte del *note ABI Stabile: 776.'

     Deprecato dalla versione 3.12: Use *note
     PyErr_SetRaisedException(): 42c. instead.

     Set the error indicator from the three objects, 'type', 'value',
     and 'traceback', clearing the existing exception if one is set.  If
     the objects are ‘NULL’, the error indicator is cleared.  Do not
     pass a ‘NULL’ type and non-‘NULL’ value or traceback.  The
     exception type should be a class.  Do not pass an invalid exception
     type or value.  (Violating these rules will cause subtle problems
     later.)  This call takes away a reference to each object: you must
     own a reference to each object before the call and after the call
     you no longer own these references.  (If you don’t understand this,
     don’t use this function.  I warned you.)

          Nota: This function is normally only used by legacy code that
          needs to save and restore the error indicator temporarily.
          Use *note PyErr_Fetch(): 428. to save the current error
          indicator.

 -- C Funzione: void PyErr_NormalizeException (PyObject **exc, PyObject
          **val, PyObject **tb)
     ' Parte del *note ABI Stabile: 776.'

     Deprecato dalla versione 3.12: Use *note
     PyErr_GetRaisedException(): 429. instead, to avoid any possible
     de-normalization.

     Under certain circumstances, the values returned by *note
     PyErr_Fetch(): 428. below can be «unnormalized», meaning that
     ‘*exc’ is a class object but ‘*val’ is not an instance of the same
     class.  This function can be used to instantiate the class in that
     case.  If the values are already normalized, nothing happens.  The
     delayed normalization is implemented to improve performance.

          Nota: This function 'does not' implicitly set the *note
          __traceback__: 14ce. attribute on the exception value.  If
          setting the traceback appropriately is desired, the following
          additional snippet is needed:

               if (tb != NULL) {
                 PyException_SetTraceback(val, tb);
               }

 -- C Funzione: *note PyObject: 5df. *PyErr_GetHandledException (void)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Retrieve
     the active exception instance, as would be returned by *note
     sys.exception(): 89c.  This refers to an exception that was
     'already caught', not to an exception that was freshly raised.
     Returns a new reference to the exception or ‘NULL’.  Does not
     modify the interpreter’s exception state.

          Nota: This function is not normally used by code that wants to
          handle exceptions.  Rather, it can be used when code needs to
          save and restore the exception state temporarily.  Use *note
          PyErr_SetHandledException(): 975. to restore or clear the
          exception state.

     Added in version 3.11.

 -- C Funzione: void PyErr_SetHandledException (PyObject *exc)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Set the
     active exception, as known from ‘sys.exception()’.  This refers to
     an exception that was 'already caught', not to an exception that
     was freshly raised.  To clear the exception state, pass ‘NULL’.

          Nota: This function is not normally used by code that wants to
          handle exceptions.  Rather, it can be used when code needs to
          save and restore the exception state temporarily.  Use *note
          PyErr_GetHandledException(): 974. to get the exception state.

     Added in version 3.11.

 -- C Funzione: void PyErr_GetExcInfo (PyObject **ptype, PyObject
          **pvalue, PyObject **ptraceback)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Retrieve
     the old-style representation of the exception info, as known from
     *note sys.exc_info(): 89b.  This refers to an exception that was
     'already caught', not to an exception that was freshly raised.
     Returns new references for the three objects, any of which may be
     ‘NULL’.  Does not modify the exception info state.  This function
     is kept for backwards compatibility.  Prefer using *note
     PyErr_GetHandledException(): 974.

          Nota: This function is not normally used by code that wants to
          handle exceptions.  Rather, it can be used when code needs to
          save and restore the exception state temporarily.  Use *note
          PyErr_SetExcInfo(): 976. to restore or clear the exception
          state.

     Added in version 3.3.

 -- C Funzione: void PyErr_SetExcInfo (PyObject *type, PyObject *value,
          PyObject *traceback)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Set the
     exception info, as known from ‘sys.exc_info()’.  This refers to an
     exception that was 'already caught', not to an exception that was
     freshly raised.  This function steals the references of the
     arguments.  To clear the exception state, pass ‘NULL’ for all three
     arguments.  This function is kept for backwards compatibility.
     Prefer using *note PyErr_SetHandledException(): 975.

          Nota: This function is not normally used by code that wants to
          handle exceptions.  Rather, it can be used when code needs to
          save and restore the exception state temporarily.  Use *note
          PyErr_GetExcInfo(): 977. to read the exception state.

     Added in version 3.3.

     Cambiato nella versione 3.11: The ‘type’ and ‘traceback’ arguments
     are no longer used and can be NULL. The interpreter now derives
     them from the exception instance (the ‘value’ argument).  The
     function still steals references of all three arguments.


File: python.info,  Node: Signal Handling<2>,  Next: Exception Classes,  Prev: Querying the error indicator,  Up: Exception Handling

7.5.5 Signal Handling
---------------------

 -- C Funzione: int PyErr_CheckSignals ()
     ' Parte del *note ABI Stabile: 776.'

     This function interacts with Python’s signal handling.

     If the function is called from the main thread and under the main
     Python interpreter, it checks whether a signal has been sent to the
     processes and if so, invokes the corresponding signal handler.  If
     the *note signal: cb. module is supported, this can invoke a signal
     handler written in Python.

     The function attempts to handle all pending signals, and then
     returns ‘0’.  However, if a Python signal handler raises an
     exception, the error indicator is set and the function returns ‘-1’
     immediately (such that other pending signals may not have been
     handled yet: they will be on the next *note PyErr_CheckSignals():
     694. invocation).

     If the function is called from a non-main thread, or under a
     non-main Python interpreter, it does nothing and returns ‘0’.

     This function can be called by long-running C code that wants to be
     interruptible by user requests (such as by pressing Ctrl-C).

          Nota: The default Python signal handler for ‘SIGINT’ raises
          the *note KeyboardInterrupt: bc7. exception.

 -- C Funzione: void PyErr_SetInterrupt ()
     ' Parte del *note ABI Stabile: 776.'

     Simulate the effect of a ‘SIGINT’ signal arriving.  This is
     equivalent to ‘PyErr_SetInterruptEx(SIGINT)’.

          Nota: This function is async-signal-safe.  It can be called
          without an *note attached thread state: 4eba. and from a C
          signal handler.

 -- C Funzione: int PyErr_SetInterruptEx (int signum)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'

     Simulate the effect of a signal arriving.  The next time *note
     PyErr_CheckSignals(): 694. is called, the Python signal handler for
     the given signal number will be called.

     This function can be called by C code that sets up its own signal
     handling and wants Python signal handlers to be invoked as expected
     when an interruption is requested (for example when the user
     presses Ctrl-C to interrupt an operation).

     If the given signal isn’t handled by Python (it was set to *note
     signal.SIG_DFL: 1b9a. or *note signal.SIG_IGN: 1b99.), it will be
     ignored.

     If 'signum' is outside of the allowed range of signal numbers, ‘-1’
     is returned.  Otherwise, ‘0’ is returned.  The error indicator is
     never changed by this function.

          Nota: This function is async-signal-safe.  It can be called
          without an *note attached thread state: 4eba. and from a C
          signal handler.

     Added in version 3.10.

 -- C Funzione: int PySignal_SetWakeupFd (int fd)

     This utility function specifies a file descriptor to which the
     signal number is written as a single byte whenever a signal is
     received.  'fd' must be non-blocking.  It returns the previous such
     file descriptor.

     The value ‘-1’ disables the feature; this is the initial state.
     This is equivalent to *note signal.set_wakeup_fd(): d69. in Python,
     but without any error checking.  'fd' should be a valid file
     descriptor.  The function should only be called from the main
     thread.

     Cambiato nella versione 3.5: On Windows, the function now also
     supports socket handles.


File: python.info,  Node: Exception Classes,  Next: Exception Objects,  Prev: Signal Handling<2>,  Up: Exception Handling

7.5.6 Exception Classes
-----------------------

 -- C Funzione: *note PyObject: 5df. *PyErr_NewException (const char
          *name, PyObject *base, PyObject *dict)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This utility function creates and returns a new
     exception class.  The 'name' argument must be the name of the new
     exception, a C string of the form ‘module.classname’.  The 'base'
     and 'dict' arguments are normally ‘NULL’.  This creates a class
     object derived from *note Exception: bcf. (accessible in C as *note
     PyExc_Exception: 4fc9.).

     The *note __module__: 617. attribute of the new class is set to the
     first part (up to the last dot) of the 'name' argument, and the
     class name is set to the last part (after the last dot).  The
     'base' argument can be used to specify alternate base classes; it
     can either be only one class or a tuple of classes.  The 'dict'
     argument can be used to specify a dictionary of class variables and
     methods.

 -- C Funzione: *note PyObject: 5df. *PyErr_NewExceptionWithDoc (const
          char *name, const char *doc, PyObject *base, PyObject *dict)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Same as *note PyErr_NewException(): 1471, except
     that the new exception class can easily be given a docstring: If
     'doc' is non-‘NULL’, it will be used as the docstring for the
     exception class.

     Added in version 3.2.

 -- C Funzione: int PyExceptionClass_Check (PyObject *ob)

     Return non-zero if 'ob' is an exception class, zero otherwise.
     This function always succeeds.

 -- C Funzione: const char *PyExceptionClass_Name (PyObject *ob)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.8.'  Return
     *note tp_name: 1c98. of the exception class 'ob'.


File: python.info,  Node: Exception Objects,  Next: Unicode Exception Objects,  Prev: Exception Classes,  Up: Exception Handling

7.5.7 Exception Objects
-----------------------

 -- C Funzione: int PyExceptionInstance_Check (PyObject *op)

     Return true if 'op' is an instance of *note BaseException: 7d8,
     false otherwise.  This function always succeeds.

 -- C Macro: PyExceptionInstance_Class (op)

     Equivalent to *note Py_TYPE(op): 3c9.

 -- C Funzione: *note PyObject: 5df. *PyException_GetTraceback (PyObject
          *ex)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the traceback associated with the exception
     as a new reference, as accessible from Python through the *note
     __traceback__: 14ce. attribute.  If there is no traceback
     associated, this returns ‘NULL’.

 -- C Funzione: int PyException_SetTraceback (PyObject *ex, PyObject
          *tb)
     ' Parte del *note ABI Stabile: 776.'  Set the traceback associated
     with the exception to 'tb'.  Use ‘Py_None’ to clear it.

 -- C Funzione: *note PyObject: 5df. *PyException_GetContext (PyObject
          *ex)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the context (another exception instance
     during whose handling 'ex' was raised) associated with the
     exception as a new reference, as accessible from Python through the
     *note __context__: 14cf. attribute.  If there is no context
     associated, this returns ‘NULL’.

 -- C Funzione: void PyException_SetContext (PyObject *ex, PyObject
          *ctx)
     ' Parte del *note ABI Stabile: 776.'  Set the context associated
     with the exception to 'ctx'.  Use ‘NULL’ to clear it.  There is no
     type check to make sure that 'ctx' is an exception instance.  This
     steals a reference to 'ctx'.

 -- C Funzione: *note PyObject: 5df. *PyException_GetCause (PyObject
          *ex)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the cause (either an exception instance, or
     ‘None’, set by ‘raise ... from ...’) associated with the exception
     as a new reference, as accessible from Python through the *note
     __cause__: 14d0. attribute.

 -- C Funzione: void PyException_SetCause (PyObject *ex, PyObject
          *cause)
     ' Parte del *note ABI Stabile: 776.'  Set the cause associated with
     the exception to 'cause'.  Use ‘NULL’ to clear it.  There is no
     type check to make sure that 'cause' is either an exception
     instance or ‘None’.  This steals a reference to 'cause'.

     The *note __suppress_context__: 24f0. attribute is implicitly set
     to ‘True’ by this function.

 -- C Funzione: *note PyObject: 5df. *PyException_GetArgs (PyObject *ex)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.12.'  Return *note args: 78e. of
     exception 'ex'.

 -- C Funzione: void PyException_SetArgs (PyObject *ex, PyObject *args)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Set
     *note args: 78e. of exception 'ex' to 'args'.

 -- C Funzione: *note PyObject: 5df. *PyUnstable_Exc_PrepReraiseStar
          (PyObject *orig, PyObject *excs)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Implement part of the interpreter’s implementation of ‘except*’.
     'orig' is the original exception that was caught, and 'excs' is the
     list of the exceptions that need to be raised.  This list contains
     the unhandled part of 'orig', if any, as well as the exceptions
     that were raised from the ‘except*’ clauses (so they have a
     different traceback from 'orig') and those that were reraised (and
     have the same traceback as 'orig').  Return the *note
     ExceptionGroup: 4d3. that needs to be reraised in the end, or
     ‘None’ if there is nothing to reraise.

     Added in version 3.12.


File: python.info,  Node: Unicode Exception Objects,  Next: Recursion Control,  Prev: Exception Objects,  Up: Exception Handling

7.5.8 Unicode Exception Objects
-------------------------------

The following functions are used to create and modify Unicode exceptions
from C.

 -- C Funzione: *note PyObject: 5df. *PyUnicodeDecodeError_Create (const
          char *encoding, const char *object, Py_ssize_t length,
          Py_ssize_t start, Py_ssize_t end, const char *reason)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a *note UnicodeDecodeError: c0a. object with
     the attributes 'encoding', 'object', 'length', 'start', 'end' and
     'reason'.  'encoding' and 'reason' are UTF-8 encoded strings.

 -- C Funzione: *note PyObject: 5df. *PyUnicodeDecodeError_GetEncoding
          (PyObject *exc)
 -- C Funzione: *note PyObject: 5df. *PyUnicodeEncodeError_GetEncoding
          (PyObject *exc)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the 'encoding' attribute of the given
     exception object.

 -- C Funzione: *note PyObject: 5df. *PyUnicodeDecodeError_GetObject
          (PyObject *exc)
 -- C Funzione: *note PyObject: 5df. *PyUnicodeEncodeError_GetObject
          (PyObject *exc)
 -- C Funzione: *note PyObject: 5df. *PyUnicodeTranslateError_GetObject
          (PyObject *exc)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the 'object' attribute of the given
     exception object.

 -- C Funzione: int PyUnicodeDecodeError_GetStart (PyObject *exc,
          Py_ssize_t *start)
 -- C Funzione: int PyUnicodeEncodeError_GetStart (PyObject *exc,
          Py_ssize_t *start)
 -- C Funzione: int PyUnicodeTranslateError_GetStart (PyObject *exc,
          Py_ssize_t *start)
     ' Parte del *note ABI Stabile: 776.'  Get the 'start' attribute of
     the given exception object and place it into '*start'.  'start'
     must not be ‘NULL’.  Return ‘0’ on success, ‘-1’ on failure.

     If the *note UnicodeError.object: 18e4. is an empty sequence, the
     resulting 'start' is ‘0’.  Otherwise, it is clipped to ‘[0,
     len(object) - 1]’.

     Vedi anche
     ..........

     *note UnicodeError.start: 18a8.

 -- C Funzione: int PyUnicodeDecodeError_SetStart (PyObject *exc,
          Py_ssize_t start)
 -- C Funzione: int PyUnicodeEncodeError_SetStart (PyObject *exc,
          Py_ssize_t start)
 -- C Funzione: int PyUnicodeTranslateError_SetStart (PyObject *exc,
          Py_ssize_t start)
     ' Parte del *note ABI Stabile: 776.'  Set the 'start' attribute of
     the given exception object to 'start'.  Return ‘0’ on success, ‘-1’
     on failure.

          Nota: While passing a negative 'start' does not raise an
          exception, the corresponding getters will not consider it as a
          relative offset.

 -- C Funzione: int PyUnicodeDecodeError_GetEnd (PyObject *exc,
          Py_ssize_t *end)
 -- C Funzione: int PyUnicodeEncodeError_GetEnd (PyObject *exc,
          Py_ssize_t *end)
 -- C Funzione: int PyUnicodeTranslateError_GetEnd (PyObject *exc,
          Py_ssize_t *end)
     ' Parte del *note ABI Stabile: 776.'  Get the 'end' attribute of
     the given exception object and place it into '*end'.  'end' must
     not be ‘NULL’.  Return ‘0’ on success, ‘-1’ on failure.

     If the *note UnicodeError.object: 18e4. is an empty sequence, the
     resulting 'end' is ‘0’.  Otherwise, it is clipped to ‘[1,
     len(object)]’.

 -- C Funzione: int PyUnicodeDecodeError_SetEnd (PyObject *exc,
          Py_ssize_t end)
 -- C Funzione: int PyUnicodeEncodeError_SetEnd (PyObject *exc,
          Py_ssize_t end)
 -- C Funzione: int PyUnicodeTranslateError_SetEnd (PyObject *exc,
          Py_ssize_t end)
     ' Parte del *note ABI Stabile: 776.'  Set the 'end' attribute of
     the given exception object to 'end'.  Return ‘0’ on success, ‘-1’
     on failure.

     Vedi anche
     ..........

     *note UnicodeError.end: 18a9.

 -- C Funzione: *note PyObject: 5df. *PyUnicodeDecodeError_GetReason
          (PyObject *exc)
 -- C Funzione: *note PyObject: 5df. *PyUnicodeEncodeError_GetReason
          (PyObject *exc)
 -- C Funzione: *note PyObject: 5df. *PyUnicodeTranslateError_GetReason
          (PyObject *exc)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the 'reason' attribute of the given
     exception object.

 -- C Funzione: int PyUnicodeDecodeError_SetReason (PyObject *exc, const
          char *reason)
 -- C Funzione: int PyUnicodeEncodeError_SetReason (PyObject *exc, const
          char *reason)
 -- C Funzione: int PyUnicodeTranslateError_SetReason (PyObject *exc,
          const char *reason)
     ' Parte del *note ABI Stabile: 776.'  Set the 'reason' attribute of
     the given exception object to 'reason'.  Return ‘0’ on success,
     ‘-1’ on failure.


File: python.info,  Node: Recursion Control,  Next: Exception and warning types,  Prev: Unicode Exception Objects,  Up: Exception Handling

7.5.9 Recursion Control
-----------------------

These two functions provide a way to perform safe recursive calls at the
C level, both in the core and in extension modules.  They are needed if
the recursive code does not necessarily invoke Python code (which tracks
its recursion depth automatically).  They are also not needed for
'tp_call' implementations because the *note call protocol: 7a4. takes
care of recursion handling.

 -- C Funzione: int Py_EnterRecursiveCall (const char *where)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.9.'  Marks a
     point where a recursive C-level call is about to be performed.

     The function then checks if the stack limit is reached.  If this is
     the case, a *note RecursionError: f6a. is set and a nonzero value
     is returned.  Otherwise, zero is returned.

     'where' should be a UTF-8 encoded string such as ‘" in instance
     check"’ to be concatenated to the *note RecursionError: f6a.
     message caused by the recursion depth limit.

     Vedi anche
     ..........

     The *note PyUnstable_ThreadState_SetStackProtection(): 466.
     function.

     Cambiato nella versione 3.9: This function is now also available in
     the *note limited API: 637.

 -- C Funzione: void Py_LeaveRecursiveCall (void)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.9.'  Ends a
     *note Py_EnterRecursiveCall(): 3d2.  Must be called once for each
     'successful' invocation of *note Py_EnterRecursiveCall(): 3d2.

     Cambiato nella versione 3.9: This function is now also available in
     the *note limited API: 637.

Properly implementing *note tp_repr: 4ecd. for container types requires
special recursion handling.  In addition to protecting the stack, *note
tp_repr: 4ecd. also needs to track objects to prevent cycles.  The
following two functions facilitate this functionality.  Effectively,
these are the C equivalent to *note reprlib.recursive_repr(): 13fb.

 -- C Funzione: int Py_ReprEnter (PyObject *object)
     ' Parte del *note ABI Stabile: 776.'  Called at the beginning of
     the *note tp_repr: 4ecd. implementation to detect cycles.

     If the object has already been processed, the function returns a
     positive integer.  In that case the *note tp_repr: 4ecd.
     implementation should return a string object indicating a cycle.
     As examples, *note dict: 183. objects return ‘{...}’ and *note
     list: 24d. objects return ‘[...]’.

     The function will return a negative integer if the recursion limit
     is reached.  In that case the *note tp_repr: 4ecd. implementation
     should typically return ‘NULL’.

     Otherwise, the function returns zero and the *note tp_repr: 4ecd.
     implementation can continue normally.

 -- C Funzione: void Py_ReprLeave (PyObject *object)
     ' Parte del *note ABI Stabile: 776.'  Ends a *note Py_ReprEnter():
     510d.  Must be called once for each invocation of *note
     Py_ReprEnter(): 510d. that returns zero.

 -- C Funzione: int Py_GetRecursionLimit (void)
     ' Parte del *note ABI Stabile: 776.'  Get the recursion limit for
     the current interpreter.  It can be set with *note
     Py_SetRecursionLimit(): 510f.  The recursion limit prevents the
     Python interpreter stack from growing infinitely.

     This function cannot fail, and the caller must hold an *note
     attached thread state: 4eba.

     Vedi anche
     ..........

     *note sys.getrecursionlimit(): 6ec.

 -- C Funzione: void Py_SetRecursionLimit (int new_limit)
     ' Parte del *note ABI Stabile: 776.'  Set the recursion limit for
     the current interpreter.

     This function cannot fail, and the caller must hold an *note
     attached thread state: 4eba.

     Vedi anche
     ..........

     *note sys.setrecursionlimit(): 6eb.


File: python.info,  Node: Exception and warning types,  Next: Tracebacks,  Prev: Recursion Control,  Up: Exception Handling

7.5.10 Exception and warning types
----------------------------------

All standard Python exceptions and warning categories are available as
global variables whose names are ‘PyExc_’ followed by the Python
exception name.  These have the type *note PyObject: 5df.*; they are all
class objects.

For completeness, here are all the variables:

* Menu:

* Exception types::
* OSError aliases::
* Warning types::


File: python.info,  Node: Exception types,  Next: OSError aliases,  Up: Exception and warning types

7.5.10.1 Exception types
........................

C name                                                 Python name
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
 -- C Variabile: *note PyObject: 5df.                  *note BaseException: 7d8.
          *PyExc_BaseException                         
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note BaseExceptionGroup: 566.
          *PyExc_BaseExceptionGroup                    
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.11.'

 -- C Variabile: *note PyObject: 5df.                  *note Exception: bcf.
          *PyExc_Exception                             
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note ArithmeticError: 26c8.
          *PyExc_ArithmeticError                       
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note AssertionError: 8b9.
          *PyExc_AssertionError                        
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note AttributeError: 5f0.
          *PyExc_AttributeError                        
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note BlockingIOError: 235.
          *PyExc_BlockingIOError                       
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note BrokenPipeError: 125e.
          *PyExc_BrokenPipeError                       
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note BufferError: 177f.
          *PyExc_BufferError                           
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note ChildProcessError: 125a.
          *PyExc_ChildProcessError                     
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note ConnectionAbortedError: 125f.
          *PyExc_ConnectionAbortedError                
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note ConnectionError: 100d.
          *PyExc_ConnectionError                       
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note ConnectionRefusedError: 1260.
          *PyExc_ConnectionRefusedError                
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note ConnectionResetError: 1261.
          *PyExc_ConnectionResetError                  
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note EOFError: 14e1.
          *PyExc_EOFError                              
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note FileExistsError: 1222.
          *PyExc_FileExistsError                       
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note FileNotFoundError: 264.
          *PyExc_FileNotFoundError                     
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note FloatingPointError: 26c9.
          *PyExc_FloatingPointError                    
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note GeneratorExit: 15cf.
          *PyExc_GeneratorExit                         
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note ImportError: 65b.
          *PyExc_ImportError                           
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note IndentationError: 9ad.
          *PyExc_IndentationError                      
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note IndexError: 173c.
          *PyExc_IndexError                            
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note InterruptedError: f8a.
          *PyExc_InterruptedError                      
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note IsADirectoryError: 125b.
          *PyExc_IsADirectoryError                     
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note KeyError: 5e7.
          *PyExc_KeyError                              
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note KeyboardInterrupt: bc7.
          *PyExc_KeyboardInterrupt                     
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note LookupError: 2633.
          *PyExc_LookupError                           
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note MemoryError: 1786.
          *PyExc_MemoryError                           
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note ModuleNotFoundError: d3f.
          *PyExc_ModuleNotFoundError                   
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.6.'

 -- C Variabile: *note PyObject: 5df.                  *note NameError: 452.
          *PyExc_NameError                             
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note NotADirectoryError: 125c.
          *PyExc_NotADirectoryError                    
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note NotImplementedError: 36b.
          *PyExc_NotImplementedError                   
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df. *PyExc_OSError   *note OSError: 2c0.
     ' Parte del *note ABI Stabile: 776.'              

 -- C Variabile: *note PyObject: 5df.                  *note OverflowError: a83.
          *PyExc_OverflowError                         
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note PermissionError: f40.
          *PyExc_PermissionError                       
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note ProcessLookupError: 125d.
          *PyExc_ProcessLookupError                    
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note PythonFinalizationError: 479.
          *PyExc_PythonFinalizationError               

 -- C Variabile: *note PyObject: 5df.                  *note RecursionError: f6a.
          *PyExc_RecursionError                        
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note ReferenceError: 1714.
          *PyExc_ReferenceError                        
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note RuntimeError: 244.
          *PyExc_RuntimeError                          
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note StopAsyncIteration: 1df7.
          *PyExc_StopAsyncIteration                    
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note StopIteration: df7.
          *PyExc_StopIteration                         
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note SyntaxError: 18e.
          *PyExc_SyntaxError                           
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note SystemError: 796.
          *PyExc_SystemError                           
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note SystemExit: f3e.
          *PyExc_SystemExit                            
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note TabError: 766.
          *PyExc_TabError                              
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note TimeoutError: a38.
          *PyExc_TimeoutError                          
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note TypeError: 198.
          *PyExc_TypeError                             
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note UnboundLocalError: 173d.
          *PyExc_UnboundLocalError                     
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note UnicodeDecodeError: c0a.
          *PyExc_UnicodeDecodeError                    
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note UnicodeEncodeError: 888.
          *PyExc_UnicodeEncodeError                    
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note UnicodeError: 462.
          *PyExc_UnicodeError                          
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note UnicodeTranslateError: 18e5.
          *PyExc_UnicodeTranslateError                 
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note ValueError: 2ec.
          *PyExc_ValueError                            
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note ZeroDivisionError: b41.
          *PyExc_ZeroDivisionError                     
     ' Parte del *note ABI Stabile: 776.'

Added in version 3.3: *note PyExc_BlockingIOError: 4fbc, *note
PyExc_BrokenPipeError: 4fbd, *note PyExc_ChildProcessError: 4fc0, *note
PyExc_ConnectionError: 4fc2, *note PyExc_ConnectionAbortedError: 4fc1,
*note PyExc_ConnectionRefusedError: 4fc3, *note
PyExc_ConnectionResetError: 4fc4, *note PyExc_FileExistsError: 4fca,
*note PyExc_FileNotFoundError: 4fcb, *note PyExc_InterruptedError: 4fd4,
*note PyExc_IsADirectoryError: 4fd5, *note PyExc_NotADirectoryError:
4fdc, *note PyExc_PermissionError: 4fe0, *note PyExc_ProcessLookupError:
4fe1. and *note PyExc_TimeoutError: 4fed. were introduced following PEP
3151(1).

Added in version 3.5: *note PyExc_StopAsyncIteration: 4fe6. and *note
PyExc_RecursionError: 10b4.

Added in version 3.6: *note PyExc_ModuleNotFoundError: 4fda.

Added in version 3.11: *note PyExc_BaseExceptionGroup: 4fbb.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3151/


File: python.info,  Node: OSError aliases,  Next: Warning types,  Prev: Exception types,  Up: Exception and warning types

7.5.10.2 OSError aliases
........................

The following are a compatibility aliases to *note PyExc_OSError: 4e84.

Cambiato nella versione 3.3: These aliases used to be separate exception
types.

C name                                Python name                           Notes
                                                                            
------------------------------------------------------------------------------------------------------------------
                                                                            
 -- C Variabile:                      *note OSError: 2c0.
          *note PyObject: 5df.        
          *PyExc_EnvironmentError
     ' Parte del
     *note ABI Stabile: 776.'

 -- C Variabile:                      *note OSError: 2c0.
          *note PyObject: 5df.        
          *PyExc_IOError
     ' Parte del
     *note ABI Stabile: 776.'

 -- C Variabile:                      *note OSError: 2c0.                   *note [win]: 51de.
          *note PyObject: 5df.                                              
          *PyExc_WindowsError
     ' Parte del
     *note ABI Stabile: 776. on
     Windows dalla versione 3.7.'

Notes:

(win) ‘PyExc_WindowsError’ is only defined on Windows; protect code that
uses this by testing that the preprocessor macro ‘MS_WINDOWS’ is
defined.


File: python.info,  Node: Warning types,  Prev: OSError aliases,  Up: Exception and warning types

7.5.10.3 Warning types
......................

C name                                                 Python name
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
 -- C Variabile: *note PyObject: 5df. *PyExc_Warning   *note Warning: 26f5.
     ' Parte del *note ABI Stabile: 776.'              

 -- C Variabile: *note PyObject: 5df.                  *note BytesWarning: e1e.
          *PyExc_BytesWarning                          
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note DeprecationWarning: 1a3.
          *PyExc_DeprecationWarning                    
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note EncodingWarning: 2117.
          *PyExc_EncodingWarning                       
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.10.'

 -- C Variabile: *note PyObject: 5df.                  *note FutureWarning: 659.
          *PyExc_FutureWarning                         
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note ImportWarning: 71f.
          *PyExc_ImportWarning                         
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note PendingDeprecationWarning: ac8.
          *PyExc_PendingDeprecationWarning             
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note ResourceWarning: 54d.
          *PyExc_ResourceWarning                       
     ' Parte del *note ABI Stabile: 776. dalla
     versione 3.7.'

 -- C Variabile: *note PyObject: 5df.                  *note RuntimeWarning: 4d8.
          *PyExc_RuntimeWarning                        
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note SyntaxWarning: 1ae.
          *PyExc_SyntaxWarning                         
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note UnicodeWarning: 162b.
          *PyExc_UnicodeWarning                        
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyObject: 5df.                  *note UserWarning: 26f6.
          *PyExc_UserWarning                           
     ' Parte del *note ABI Stabile: 776.'

Added in version 3.2: *note PyExc_ResourceWarning: 4fe3.

Added in version 3.10: *note PyExc_EncodingWarning: 4fc7.


File: python.info,  Node: Tracebacks,  Prev: Exception and warning types,  Up: Exception Handling

7.5.11 Tracebacks
-----------------

 -- C Variabile: *note PyTypeObject: c9e. PyTraceBack_Type
     ' Parte del *note ABI Stabile: 776.'  Type object for traceback
     objects.  This is available as *note types.TracebackType: cec. in
     the Python layer.

 -- C Funzione: int PyTraceBack_Check (PyObject *op)

     Return true if 'op' is a traceback object, false otherwise.  This
     function does not account for subtypes.

 -- C Funzione: int PyTraceBack_Here (PyFrameObject *f)
     ' Parte del *note ABI Stabile: 776.'  Replace the *note
     __traceback__: 14ce. attribute on the current exception with a new
     traceback prepending 'f' to the existing chain.

     Calling this function without an exception set is undefined
     behavior.

     This function returns ‘0’ on success, and returns ‘-1’ with an
     exception set on failure.

 -- C Funzione: int PyTraceBack_Print (PyObject *tb, PyObject *f)
     ' Parte del *note ABI Stabile: 776.'  Write the traceback 'tb' into
     the file 'f'.

     This function returns ‘0’ on success, and returns ‘-1’ with an
     exception set on failure.


File: python.info,  Node: Defining extension modules,  Next: Utilities<2>,  Prev: Exception Handling,  Up: Python/C API Reference Manual

7.6 Defining extension modules
==============================

A C extension for CPython is a shared library (for example, a ‘.so’ file
on Linux, ‘.pyd’ DLL on Windows), which is loadable into the Python
process (for example, it is compiled with compatible compiler settings),
and which exports an *note initialization function: 51e5.

To be importable by default (that is, by *note
importlib.machinery.ExtensionFileLoader: eb0.), the shared library must
be available on *note sys.path: 3e4, and must be named after the module
name plus an extension listed in *note
importlib.machinery.EXTENSION_SUFFIXES: 73a.

     Nota: Building, packaging and distributing extension modules is
     best done with third-party tools, and is out of scope of this
     document.  One suitable tool is Setuptools, whose documentation can
     be found at ‘https://setuptools.pypa.io/en/latest/setuptools.html’.

Normally, the initialization function returns a module definition
initialized using *note PyModuleDef_Init(): 4e8c.  This allows splitting
the creation process into several phases:

   - Before any substantial code is executed, Python can determine which
     capabilities the module supports, and it can adjust the environment
     or refuse loading an incompatible extension.

   - By default, Python itself creates the module object – that is, it
     does the equivalent of *note object.__new__(): 7a1. for classes.
     It also sets initial attributes like *note __package__: 323. and
     *note __loader__: 33b.

   - Afterwards, the module object is initialized using
     extension-specific code – the equivalent of *note __init__(): 8c0.
     on classes.

This is called 'multi-phase initialization' to distinguish it from the
legacy (but still supported) 'single-phase initialization' scheme, where
the initialization function returns a fully constructed module.  See the
*note single-phase-initialization section below: 51e6. for details.

Cambiato nella versione 3.5: Added support for multi-phase
initialization ( PEP 489(1)).

* Menu:

* Multiple module instances::
* Initialization function::
* Multi-phase initialization::
* Legacy single-phase initialization::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0489/


File: python.info,  Node: Multiple module instances,  Next: Initialization function,  Up: Defining extension modules

7.6.1 Multiple module instances
-------------------------------

By default, extension modules are not singletons.  For example, if the
*note sys.modules: 17ce. entry is removed and the module is re-imported,
a new module object is created, and typically populated with fresh
method and type objects.  The old module is subject to normal garbage
collection.  This mirrors the behavior of pure-Python modules.

Additional module instances may be created in *note sub-interpreters:
163. or after Python runtime reinitialization (*note Py_Finalize(): 45f.
and *note Py_Initialize(): 460.).  In these cases, sharing Python
objects between module instances would likely cause crashes or undefined
behavior.

To avoid such issues, each instance of an extension module should be
'isolated': changes to one instance should not implicitly affect the
others, and all state owned by the module, including references to
Python objects, should be specific to a particular module instance.  See
*note Isolating Extension Modules: 166. for more details and a practical
guide.

A simpler way to avoid these issues is *note raising an error on
repeated initialization: 51e8.

All modules are expected to support *note sub-interpreters: 163, or
otherwise explicitly signal a lack of support.  This is usually achieved
by isolation or blocking repeated initialization, as above.  A module
may also be limited to the main interpreter using the *note
Py_mod_multiple_interpreters: 512a. slot.


File: python.info,  Node: Initialization function,  Next: Multi-phase initialization,  Prev: Multiple module instances,  Up: Defining extension modules

7.6.2 Initialization function
-----------------------------

The initialization function defined by an extension module has the
following signature:

 -- C Funzione: *note PyObject: 5df. *PyInit_modulename (void)

Its name should be ‘PyInit_<NAME>’, with ‘<name>’ replaced by the name
of the module.

For modules with ASCII-only names, the function must instead be named
‘PyInit_<NAME>’, with ‘<name>’ replaced by the name of the module.  When
using *note Multi-phase initialization: 51eb, non-ASCII module names are
allowed.  In this case, the initialization function name is
‘PyInitU_<NAME>’, with ‘<name>’ encoded using Python’s 'punycode'
encoding with hyphens replaced by underscores.  In Python:

     def initfunc_name(name):
         try:
             suffix = b'_' + name.encode('ascii')
         except UnicodeEncodeError:
             suffix = b'U_' + name.encode('punycode').replace(b'-', b'_')
         return b'PyInit' + suffix

It is recommended to define the initialization function using a helper
macro:

 -- C Macro: PyMODINIT_FUNC

     Declare an extension module initialization function.  This macro:

        * specifies the *note PyObject: 5df.* return type,

        * adds any special linkage declarations required by the
          platform, and

        * for C++, declares the function as ‘extern "C"’.

For example, a module called ‘spam’ would be defined like this:

     static struct PyModuleDef spam_module = {
         .m_base = PyModuleDef_HEAD_INIT,
         .m_name = "spam",
         ...
     };

     PyMODINIT_FUNC
     PyInit_spam(void)
     {
         return PyModuleDef_Init(&spam_module);
     }

It is possible to export multiple modules from a single shared library
by defining multiple initialization functions.  However, importing them
requires using symbolic links or a custom importer, because by default
only the function corresponding to the filename is found.  See the
Multiple modules in one library(1) section in PEP 489(2) for details.

The initialization function is typically the only non-‘static’ item
defined in the module’s C source.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0489/#multiple-modules-in-one-library

   (2) https://peps.python.org/pep-0489/


File: python.info,  Node: Multi-phase initialization,  Next: Legacy single-phase initialization,  Prev: Initialization function,  Up: Defining extension modules

7.6.3 Multi-phase initialization
--------------------------------

Normally, the *note initialization function: 51e5. (‘PyInit_modulename’)
returns a *note PyModuleDef: b76. instance with non-‘NULL’ *note
m_slots: 51ed.  Before it is returned, the ‘PyModuleDef’ instance must
be initialized using the following function:

 -- C Funzione: *note PyObject: 5df. *PyModuleDef_Init (PyModuleDef
          *def)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.5.'  Ensure a
     module definition is a properly initialized Python object that
     correctly reports its type and a reference count.

     Return 'def' cast to ‘PyObject*’, or ‘NULL’ if an error occurred.

     Calling this function is required for *note Multi-phase
     initialization: 51eb.  It should not be used in other contexts.

     Note that Python assumes that ‘PyModuleDef’ structures are
     statically allocated.  This function may return either a new
     reference or a borrowed one; this reference must not be released.

     Added in version 3.5.


File: python.info,  Node: Legacy single-phase initialization,  Prev: Multi-phase initialization,  Up: Defining extension modules

7.6.4 Legacy single-phase initialization
----------------------------------------

     Attenzione: Single-phase initialization is a legacy mechanism to
     initialize extension modules, with known drawbacks and design
     flaws.  Extension module authors are encouraged to use multi-phase
     initialization instead.

In single-phase initialization, the *note initialization function: 51e5.
(‘PyInit_modulename’) should create, populate and return a module
object.  This is typically done using *note PyModule_Create(): 51ef. and
functions like *note PyModule_AddObjectRef(): 60a.

Single-phase initialization differs from the *note default: 51eb. in the
following ways:

   * Single-phase modules are, or rather 'contain', “singletons”.

     When the module is first initialized, Python saves the contents of
     the module’s ‘__dict__’ (that is, typically, the module’s functions
     and types).

     For subsequent imports, Python does not call the initialization
     function again.  Instead, it creates a new module object with a new
     ‘__dict__’, and copies the saved contents to it.  For example,
     given a single-phase module ‘_testsinglephase’ (1) that defines a
     function ‘sum’ and an exception class ‘error’:

          >>> import sys
          >>> import _testsinglephase as one
          >>> del sys.modules['_testsinglephase']
          >>> import _testsinglephase as two
          >>> one is two
          False
          >>> one.__dict__ is two.__dict__
          False
          >>> one.sum is two.sum
          True
          >>> one.error is two.error
          True

     The exact behavior should be considered a CPython implementation
     detail.

   * To work around the fact that ‘PyInit_modulename’ does not take a
     'spec' argument, some state of the import machinery is saved and
     applied to the first suitable module created during the
     ‘PyInit_modulename’ call.  Specifically, when a sub-module is
     imported, this mechanism prepends the parent package name to the
     name of the module.

     A single-phase ‘PyInit_modulename’ function should create “its”
     module object as soon as possible, before any other module objects
     can be created.

   * Non-ASCII module names (‘PyInitU_modulename’) are not supported.

   * Single-phase modules support module lookup functions like *note
     PyState_FindModule(): 508d.

   ---------- Footnotes ----------

   (1) ‘_testsinglephase’ is an internal module used in CPython’s
self-test suite; your installation may or may not include it.


File: python.info,  Node: Utilities<2>,  Next: Abstract Objects Layer,  Prev: Defining extension modules,  Up: Python/C API Reference Manual

7.7 Utilities
=============

The functions in this chapter perform various utility tasks, ranging
from helping C code be more portable across platforms, using Python
modules from C, and parsing function arguments and constructing Python
values from C values.

* Menu:

* Operating System Utilities::
* System Functions::
* Process Control::
* Importing Modules: Importing Modules<2>.
* Data marshalling support::
* Parsing arguments and building values::
* String conversion and formatting::
* Character classification and conversion::
* PyHash API::
* Reflection::
* Codec registry and support functions::
* PyTime C API::
* Support for Perf Maps::


File: python.info,  Node: Operating System Utilities,  Next: System Functions,  Up: Utilities<2>

7.7.1 Operating System Utilities
--------------------------------

 -- C Funzione: *note PyObject: 5df. *PyOS_FSPath (PyObject *path)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.6.'  Return the file system
     representation for 'path'.  If the object is a *note str: 169. or
     *note bytes: 192. object, then a new *note strong reference: 5e2.
     is returned.  If the object implements the *note os.PathLike: e4d.
     interface, then *note __fspath__(): e4e. is returned as long as it
     is a *note str: 169. or *note bytes: 192. object.  Otherwise *note
     TypeError: 198. is raised and ‘NULL’ is returned.

     Added in version 3.6.

 -- C Funzione: int Py_FdIsInteractive (FILE *fp, const char *filename)

     Return true (nonzero) if the standard I/O file 'fp' with name
     'filename' is deemed interactive.  This is the case for files for
     which ‘isatty(fileno(fp))’ is true.  If the *note
     PyConfig.interactive: 3ff. is non-zero, this function also returns
     true if the 'filename' pointer is ‘NULL’ or if the name is equal to
     one of the strings ‘'<stdin>'’ or ‘'???'’.

     This function must not be called before Python is initialized.

 -- C Funzione: void PyOS_BeforeFork ()
     ' Parte del *note ABI Stabile: 776. on platforms with fork() dalla
     versione 3.7.'  Function to prepare some internal state before a
     process fork.  This should be called before calling ‘fork()’ or any
     similar function that clones the current process.  Only available
     on systems where ‘fork()’ is defined.

          Avvertimento: The C ‘fork()’ call should only be made from the
          *note «main» thread: 51f8. (of the *note «main» interpreter:
          163.).  The same is true for ‘PyOS_BeforeFork()’.

     Added in version 3.7.

 -- C Funzione: void PyOS_AfterFork_Parent ()
     ' Parte del *note ABI Stabile: 776. on platforms with fork() dalla
     versione 3.7.'  Function to update some internal state after a
     process fork.  This should be called from the parent process after
     calling ‘fork()’ or any similar function that clones the current
     process, regardless of whether process cloning was successful.
     Only available on systems where ‘fork()’ is defined.

          Avvertimento: The C ‘fork()’ call should only be made from the
          *note «main» thread: 51f8. (of the *note «main» interpreter:
          163.).  The same is true for ‘PyOS_AfterFork_Parent()’.

     Added in version 3.7.

 -- C Funzione: void PyOS_AfterFork_Child ()
     ' Parte del *note ABI Stabile: 776. on platforms with fork() dalla
     versione 3.7.'  Function to update internal interpreter state after
     a process fork.  This must be called from the child process after
     calling ‘fork()’, or any similar function that clones the current
     process, if there is any chance the process will call back into the
     Python interpreter.  Only available on systems where ‘fork()’ is
     defined.

          Avvertimento: The C ‘fork()’ call should only be made from the
          *note «main» thread: 51f8. (of the *note «main» interpreter:
          163.).  The same is true for ‘PyOS_AfterFork_Child()’.

     Added in version 3.7.

     Vedi anche
     ..........

     *note os.register_at_fork(): 355. allows registering custom Python
     functions to be called by *note PyOS_BeforeFork(): dba, *note
     PyOS_AfterFork_Parent(): dbb. and *note PyOS_AfterFork_Child():
     430.

 -- C Funzione: void PyOS_AfterFork ()
     ' Parte del *note ABI Stabile: 776. on platforms with fork().'
     Function to update some internal state after a process fork; this
     should be called in the new process if the Python interpreter will
     continue to be used.  If a new executable is loaded into the new
     process, this function does not need to be called.

     Deprecato dalla versione 3.7: This function is superseded by *note
     PyOS_AfterFork_Child(): 430.

 -- C Funzione: int PyOS_CheckStack ()
     ' Parte del *note ABI Stabile: 776. on platforms with
     USE_STACKCHECK dalla versione 3.7.'

     Return true when the interpreter runs out of stack space.  This is
     a reliable check, but is only available when ‘USE_STACKCHECK’ is
     defined (currently on certain versions of Windows using the
     Microsoft Visual C++ compiler).  ‘USE_STACKCHECK’ will be defined
     automatically; you should never change the definition in your own
     code.

 -- C Tipo: typedef void (*PyOS_sighandler_t)(int)
     ' Parte del *note ABI Stabile: 776.'

 -- C Funzione: *note PyOS_sighandler_t: 505b. PyOS_getsig (int i)
     ' Parte del *note ABI Stabile: 776.'  Return the current signal
     handler for signal 'i'.  This is a thin wrapper around either
     ‘sigaction()’ or ‘signal()’.  Do not call those functions directly!

 -- C Funzione: *note PyOS_sighandler_t: 505b. PyOS_setsig (int i,
          PyOS_sighandler_t h)
     ' Parte del *note ABI Stabile: 776.'  Set the signal handler for
     signal 'i' to be 'h'; return the old signal handler.  This is a
     thin wrapper around either ‘sigaction()’ or ‘signal()’.  Do not
     call those functions directly!

 -- C Funzione: int PyOS_InterruptOccurred (void)
     ' Parte del *note ABI Stabile: 776.'  Check if a ‘SIGINT’ signal
     has been received.

     Returns ‘1’ if a ‘SIGINT’ has occurred and clears the signal flag,
     or ‘0’ otherwise.

     In most cases, you should prefer *note PyErr_CheckSignals(): 694.
     over this function.  ‘PyErr_CheckSignals()’ invokes the appropriate
     signal handlers for all pending signals, allowing Python code to
     handle the signal properly.  This function only detects ‘SIGINT’
     and does not invoke any Python signal handlers.

     This function is async-signal-safe and this function cannot fail.
     The caller must hold an *note attached thread state: 4eba.

 -- C Funzione: wchar_t *Py_DecodeLocale (const char *arg, size_t *size)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'
          Avvertimento: This function should not be called directly: use
          the *note PyConfig: 3f7. API with the *note
          PyConfig_SetBytesString(): bad. function which ensures that
          *note Python is preinitialized: 42af.

          This function must not be called before *note Python is
          preinitialized: 42af. and so that the LC_CTYPE locale is
          properly configured: see the *note Py_PreInitialize(): 41e.
          function.

     Decode a byte string from the *note filesystem encoding and error
     handler: 75e.  If the error handler is *note surrogateescape error
     handler: 2837, undecodable bytes are decoded as characters in range
     U+DC80..U+DCFF; and if a byte sequence can be decoded as a
     surrogate character, the bytes are escaped using the
     surrogateescape error handler instead of decoding them.

     Return a pointer to a newly allocated wide character string, use
     *note PyMem_RawFree(): 634. to free the memory.  If size is not
     ‘NULL’, write the number of wide characters excluding the null
     character into ‘*size’

     Return ‘NULL’ on decoding error or memory allocation error.  If
     'size' is not ‘NULL’, ‘*size’ is set to ‘(size_t)-1’ on memory
     error or set to ‘(size_t)-2’ on decoding error.

     The *note filesystem encoding and error handler: 75e. are selected
     by *note PyConfig_Read(): 994.: see *note filesystem_encoding: 41b.
     and *note filesystem_errors: 41c. members of *note PyConfig: 3f7.

     Decoding errors should never happen, unless there is a bug in the C
     library.

     Use the *note Py_EncodeLocale(): dc3. function to encode the
     character string back to a byte string.

     Vedi anche
     ..........

     The *note PyUnicode_DecodeFSDefaultAndSize(): 50d7. and *note
     PyUnicode_DecodeLocaleAndSize(): dc4. functions.

     Added in version 3.5.

     Cambiato nella versione 3.7: The function now uses the UTF-8
     encoding in the *note Python UTF-8 Mode: 867.

     Cambiato nella versione 3.8: The function now uses the UTF-8
     encoding on Windows if *note
     PyPreConfig.legacy_windows_fs_encoding: 418. is zero;

 -- C Funzione: char *Py_EncodeLocale (const wchar_t *text, size_t
          *error_pos)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Encode a
     wide character string to the *note filesystem encoding and error
     handler: 75e.  If the error handler is *note surrogateescape error
     handler: 2837, surrogate characters in the range U+DC80..U+DCFF are
     converted to bytes 0x80..0xFF.

     Return a pointer to a newly allocated byte string, use *note
     PyMem_Free(): 1649. to free the memory.  Return ‘NULL’ on encoding
     error or memory allocation error.

     If error_pos is not ‘NULL’, ‘*error_pos’ is set to ‘(size_t)-1’ on
     success, or set to the index of the invalid character on encoding
     error.

     The *note filesystem encoding and error handler: 75e. are selected
     by *note PyConfig_Read(): 994.: see *note filesystem_encoding: 41b.
     and *note filesystem_errors: 41c. members of *note PyConfig: 3f7.

     Use the *note Py_DecodeLocale(): dc2. function to decode the bytes
     string back to a wide character string.

          Avvertimento: This function must not be called before *note
          Python is preinitialized: 42af. and so that the LC_CTYPE
          locale is properly configured: see the *note
          Py_PreInitialize(): 41e. function.

     Vedi anche
     ..........

     The *note PyUnicode_EncodeFSDefault(): 1e19. and *note
     PyUnicode_EncodeLocale(): dc5. functions.

     Added in version 3.5.

     Cambiato nella versione 3.7: The function now uses the UTF-8
     encoding in the *note Python UTF-8 Mode: 867.

     Cambiato nella versione 3.8: The function now uses the UTF-8
     encoding on Windows if *note
     PyPreConfig.legacy_windows_fs_encoding: 418. is zero.

 -- C Funzione: FILE *Py_fopen (PyObject *path, const char *mode)

     Similar to ‘fopen()’, but 'path' is a Python object and an
     exception is set on error.

     'path' must be a *note str: 169. object, a *note bytes: 192.
     object, or a *note path-like object: 5a1.

     On success, return the new file pointer.  On error, set an
     exception and return ‘NULL’.

     The file must be closed by *note Py_fclose(): 394. rather than
     calling directly ‘fclose()’.

     The file descriptor is created non-inheritable ( PEP 446(1)).

     The caller must have an *note attached thread state: 4eba.

     Added in version 3.14.

 -- C Funzione: int Py_fclose (FILE *file)

     Close a file that was opened by *note Py_fopen(): 393.

     On success, return ‘0’.  On error, return ‘EOF’ and ‘errno’ is set
     to indicate the error.  In either case, any further access
     (including another call to *note Py_fclose(): 394.) to the stream
     results in undefined behavior.

     Added in version 3.14.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0446/


File: python.info,  Node: System Functions,  Next: Process Control,  Prev: Operating System Utilities,  Up: Utilities<2>

7.7.2 System Functions
----------------------

These are utility functions that make functionality from the *note sys:
df. module accessible to C code.  They all work with the current
interpreter thread’s *note sys: df. module’s dict, which is contained in
the internal thread state structure.

 -- C Funzione: *note PyObject: 5df. *PySys_GetObject (const char *name)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Return the object 'name' from the *note
     sys: df. module or ‘NULL’ if it does not exist, without setting an
     exception.

 -- C Funzione: int PySys_SetObject (const char *name, PyObject *v)
     ' Parte del *note ABI Stabile: 776.'  Set 'name' in the *note sys:
     df. module to 'v' unless 'v' is ‘NULL’, in which case 'name' is
     deleted from the sys module.  Returns ‘0’ on success, ‘-1’ on
     error.

 -- C Funzione: void PySys_ResetWarnOptions ()
     ' Parte del *note ABI Stabile: 776.'  Reset *note sys.warnoptions:
     3f5. to an empty list.  This function may be called prior to *note
     Py_Initialize(): 460.

     Deprecated since version 3.13, will be removed in version 3.15:
     Clear *note sys.warnoptions: 3f5. and ‘warnings.filters’ instead.

 -- C Funzione: void PySys_WriteStdout (const char *format, ...)
     ' Parte del *note ABI Stabile: 776.'  Write the output string
     described by 'format' to *note sys.stdout: ccf.  No exceptions are
     raised, even if truncation occurs (see below).

     'format' should limit the total size of the formatted output string
     to 1000 bytes or less – after 1000 bytes, the output string is
     truncated.  In particular, this means that no unrestricted «%s»
     formats should occur; these should be limited using «%.<N>s» where
     <N> is a decimal number calculated so that <N> plus the maximum
     size of other formatted text does not exceed 1000 bytes.  Also
     watch out for «%f», which can print hundreds of digits for very
     large numbers.

     If a problem occurs, or *note sys.stdout: ccf. is unset, the
     formatted message is written to the real (C level) 'stdout'.

 -- C Funzione: void PySys_WriteStderr (const char *format, ...)
     ' Parte del *note ABI Stabile: 776.'  As *note PySys_WriteStdout():
     5099, but write to *note sys.stderr: b35. or 'stderr' instead.

 -- C Funzione: void PySys_FormatStdout (const char *format, ...)
     ' Parte del *note ABI Stabile: 776.'  Function similar to
     PySys_WriteStdout() but format the message using *note
     PyUnicode_FromFormatV(): 795. and don’t truncate the message to an
     arbitrary length.

     Added in version 3.2.

 -- C Funzione: void PySys_FormatStderr (const char *format, ...)
     ' Parte del *note ABI Stabile: 776.'  As *note
     PySys_FormatStdout(): 5095, but write to *note sys.stderr: b35. or
     'stderr' instead.

     Added in version 3.2.

 -- C Funzione: *note PyObject: 5df. *PySys_GetXOptions ()
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776. dalla versione 3.7.'  Return the current
     dictionary of *note -X: 16f. options, similarly to *note
     sys._xoptions: 211a.  On error, ‘NULL’ is returned and an exception
     is set.

     Added in version 3.2.

 -- C Funzione: int PySys_Audit (const char *event, const char *format,
          ...)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Raise an
     auditing event with any active hooks.  Return zero for success and
     non-zero with an exception set on failure.

     The 'event' string argument must not be 'NULL'.

     If any hooks have been added, 'format' and other arguments will be
     used to construct a tuple to pass.  Apart from ‘N’, the same format
     characters as used in *note Py_BuildValue(): 3c2. are available.
     If the built value is not a tuple, it will be added into a
     single-element tuple.

     The ‘N’ format option must not be used.  It consumes a reference,
     but since there is no way to know whether arguments to this
     function will be consumed, using it may cause reference leaks.

     Note that ‘#’ format characters should always be treated as *note
     Py_ssize_t: c57, regardless of whether ‘PY_SSIZE_T_CLEAN’ was
     defined.

     *note sys.audit(): 1903. performs the same function from Python
     code.

     See also *note PySys_AuditTuple(): 612.

     Added in version 3.8.

     Cambiato nella versione 3.8.2: Require *note Py_ssize_t: c57. for
     ‘#’ format characters.  Previously, an unavoidable deprecation
     warning was raised.

 -- C Funzione: int PySys_AuditTuple (const char *event, PyObject *args)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Similar
     to *note PySys_Audit(): 613, but pass arguments as a Python object.
     'args' must be a *note tuple: 614.  To pass no arguments, 'args'
     can be 'NULL'.

     Added in version 3.13.

 -- C Funzione: int PySys_AddAuditHook (Py_AuditHookFunction hook, void
          *userData)

     Append the callable 'hook' to the list of active auditing hooks.
     Return zero on success and non-zero on failure.  If the runtime has
     been initialized, also set an error on failure.  Hooks added
     through this API are called for all interpreters created by the
     runtime.

     The 'userData' pointer is passed into the hook function.  Since
     hook functions may be called from different runtimes, this pointer
     should not refer directly to Python state.

     This function is safe to call before *note Py_Initialize(): 460.
     When called after runtime initialization, existing audit hooks are
     notified and may silently abort the operation by raising an error
     subclassed from *note Exception: bcf. (other errors will not be
     silenced).

     The hook function is always called with an *note attached thread
     state: 4eba. by the Python interpreter that raised the event.

     See PEP 578(1) for a detailed description of auditing.  Functions
     in the runtime and standard library that raise events are listed in
     the *note audit events table: 1bfb.  Details are in each function’s
     documentation.

     If the interpreter is initialized, this function raises an auditing
     event ‘sys.addaudithook’ with no arguments.  If any existing hooks
     raise an exception derived from *note Exception: bcf, the new hook
     will not be added and the exception is cleared.  As a result,
     callers cannot assume that their hook has been added unless they
     control all existing hooks.

      -- C Tipo: typedef int (*Py_AuditHookFunction)(const char *event,
               *note PyObject: 5df. *args, void *userData)

          The type of the hook function.  'event' is the C string event
          argument passed to *note PySys_Audit(): 613. or *note
          PySys_AuditTuple(): 612.  'args' is guaranteed to be a *note
          PyTupleObject: 51fc.  'userData' is the argument passed to
          PySys_AddAuditHook().

     Added in version 3.8.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0578/


File: python.info,  Node: Process Control,  Next: Importing Modules<2>,  Prev: System Functions,  Up: Utilities<2>

7.7.3 Process Control
---------------------

 -- C Funzione: void Py_FatalError (const char *message)
     ' Parte del *note ABI Stabile: 776.'

     Print a fatal error message and kill the process.  No cleanup is
     performed.  This function should only be invoked when a condition
     is detected that would make it dangerous to continue using the
     Python interpreter; e.g., when the object administration appears to
     be corrupted.  On Unix, the standard C library function ‘abort()’
     is called which will attempt to produce a ‘core’ file.

     The ‘Py_FatalError()’ function is replaced with a macro which logs
     automatically the name of the current function, unless the
     ‘Py_LIMITED_API’ macro is defined.

     Cambiato nella versione 3.9: Log the function name automatically.

 -- C Funzione: void Py_Exit (int status)
     ' Parte del *note ABI Stabile: 776.'

     Exit the current process.  This calls *note Py_FinalizeEx(): f13.
     and then calls the standard C library function ‘exit(status)’.  If
     *note Py_FinalizeEx(): f13. indicates an error, the exit status is
     set to 120.

     Cambiato nella versione 3.6: Errors from finalization no longer
     ignored.

 -- C Funzione: int Py_AtExit (void (*func)())
     ' Parte del *note ABI Stabile: 776.'

     Register a cleanup function to be called by *note Py_FinalizeEx():
     f13.  The cleanup function will be called with no arguments and
     should return no value.  At most 32 cleanup functions can be
     registered.  When the registration is successful, *note
     Py_AtExit(): 5100. returns ‘0’; on failure, it returns ‘-1’.  The
     cleanup function registered last is called first.  Each cleanup
     function will be called at most once.  Since Python’s internal
     finalization will have completed before the cleanup function, no
     Python APIs should be called by 'func'.

     Vedi anche
     ..........

     *note PyUnstable_AtExit(): 18e2. for passing a ‘void *data’
     argument.


File: python.info,  Node: Importing Modules<2>,  Next: Data marshalling support,  Prev: Process Control,  Up: Utilities<2>

7.7.4 Importing Modules
-----------------------

 -- C Funzione: *note PyObject: 5df. *PyImport_ImportModule (const char
          *name)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     This is a wrapper around *note PyImport_Import(): 1603. which takes
     a const char* as an argument instead of a *note PyObject: 5df.*.

 -- C Funzione: *note PyObject: 5df. *PyImport_ImportModuleNoBlock
          (const char *name)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This function is a deprecated alias of *note
     PyImport_ImportModule(): 3dc.

     Cambiato nella versione 3.3: This function used to fail immediately
     when the import lock was held by another thread.  In Python 3.3
     though, the locking scheme switched to per-module locks for most
     purposes, so this function’s special behaviour isn’t needed
     anymore.

     Deprecated since version 3.13, will be removed in version 3.15: Use
     *note PyImport_ImportModule(): 3dc. instead.

 -- C Funzione: *note PyObject: 5df. *PyImport_ImportModuleEx (const
          char *name, PyObject *globals, PyObject *locals, PyObject
          *fromlist)
     'Valore di ritorno: Nuovo riferimento.'

     Import a module.  This is best described by referring to the
     built-in Python function *note __import__(): ad3.

     The return value is a new reference to the imported module or
     top-level package, or ‘NULL’ with an exception set on failure.
     Like for *note __import__(): ad3, the return value when a submodule
     of a package was requested is normally the top-level package,
     unless a non-empty 'fromlist' was given.

     Failing imports remove incomplete module objects, like with *note
     PyImport_ImportModule(): 3dc.

 -- C Funzione: *note PyObject: 5df. *PyImport_ImportModuleLevelObject
          (PyObject *name, PyObject *globals, PyObject *locals, PyObject
          *fromlist, int level)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'  Import a module.  This is best
     described by referring to the built-in Python function *note
     __import__(): ad3, as the standard *note __import__(): ad3.
     function calls this function directly.

     The return value is a new reference to the imported module or
     top-level package, or ‘NULL’ with an exception set on failure.
     Like for *note __import__(): ad3, the return value when a submodule
     of a package was requested is normally the top-level package,
     unless a non-empty 'fromlist' was given.

     Added in version 3.3.

 -- C Funzione: *note PyObject: 5df. *PyImport_ImportModuleLevel (const
          char *name, PyObject *globals, PyObject *locals, PyObject
          *fromlist, int level)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Similar to *note
     PyImport_ImportModuleLevelObject(): 5011, but the name is a UTF-8
     encoded string instead of a Unicode object.

     Cambiato nella versione 3.3: Negative values for 'level' are no
     longer accepted.

 -- C Funzione: *note PyObject: 5df. *PyImport_Import (PyObject *name)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This is a higher-level interface that calls the
     current «import hook function» (with an explicit 'level' of 0,
     meaning absolute import).  It invokes the *note __import__(): ad3.
     function from the ‘__builtins__’ of the current globals.  This
     means that the import is done using whatever import hooks are
     installed in the current environment.

     This function always uses absolute imports.

 -- C Funzione: *note PyObject: 5df. *PyImport_ReloadModule (PyObject
          *m)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Reload a module.  Return a new reference to the
     reloaded module, or ‘NULL’ with an exception set on failure (the
     module still exists in this case).

 -- C Funzione: *note PyObject: 5df. *PyImport_AddModuleRef (const char
          *name)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.13.'  Return the module object
     corresponding to a module name.

     The 'name' argument may be of the form ‘package.module’.  First
     check the modules dictionary if there’s one there, and if not,
     create a new one and insert it in the modules dictionary.

     Return a *note strong reference: 5e2. to the module on success.
     Return ‘NULL’ with an exception set on failure.

     The module name 'name' is decoded from UTF-8.

     This function does not load or import the module; if the module
     wasn’t already loaded, you will get an empty module object.  Use
     *note PyImport_ImportModule(): 3dc. or one of its variants to
     import a module.  Package structures implied by a dotted name for
     'name' are not created if not already present.

     Added in version 3.13.

 -- C Funzione: *note PyObject: 5df. *PyImport_AddModuleObject (PyObject
          *name)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776. dalla versione 3.7.'  Similar to *note
     PyImport_AddModuleRef(): 5fb, but return a *note borrowed
     reference: 3d7. and 'name' is a Python *note str: 169. object.

     Added in version 3.3.

 -- C Funzione: *note PyObject: 5df. *PyImport_AddModule (const char
          *name)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Similar to *note PyImport_AddModuleRef():
     5fb, but return a *note borrowed reference: 3d7.

 -- C Funzione: *note PyObject: 5df. *PyImport_ExecCodeModule (const
          char *name, PyObject *co)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     Given a module name (possibly of the form ‘package.module’) and a
     code object read from a Python bytecode file or obtained from the
     built-in function *note compile(): 4b2, load the module.  Return a
     new reference to the module object, or ‘NULL’ with an exception set
     if an error occurred.  'name' is removed from *note sys.modules:
     17ce. in error cases, even if 'name' was already in *note
     sys.modules: 17ce. on entry to *note PyImport_ExecCodeModule():
     5009.  Leaving incompletely initialized modules in *note
     sys.modules: 17ce. is dangerous, as imports of such modules have no
     way to know that the module object is an unknown (and probably
     damaged with respect to the module author’s intents) state.

     The module’s *note __spec__: 234b. and *note __loader__: 33b. will
     be set, if not set already, with the appropriate values.  The
     spec’s loader will be set to the module’s ‘__loader__’ (if set) and
     to an instance of *note SourceFileLoader: 1276. otherwise.

     The module’s *note __file__: 2350. attribute will be set to the
     code object’s *note co_filename: 1575.  If applicable, *note
     __cached__: 321. will also be set.

     This function will reload the module if it was already imported.
     See *note PyImport_ReloadModule(): 5012. for the intended way to
     reload a module.

     If 'name' points to a dotted name of the form ‘package.module’, any
     package structures not already created will still not be created.

     See also *note PyImport_ExecCodeModuleEx(): 500a. and *note
     PyImport_ExecCodeModuleWithPathnames(): 500c.

     Cambiato nella versione 3.12: The setting of *note __cached__: 321.
     and *note __loader__: 33b. is deprecated.  See *note ModuleSpec:
     2255. for alternatives.

 -- C Funzione: *note PyObject: 5df. *PyImport_ExecCodeModuleEx (const
          char *name, PyObject *co, const char *pathname)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Like *note PyImport_ExecCodeModule(): 5009, but the
     *note __file__: 2350. attribute of the module object is set to
     'pathname' if it is non-‘NULL’.

     See also *note PyImport_ExecCodeModuleWithPathnames(): 500c.

 -- C Funzione: *note PyObject: 5df. *PyImport_ExecCodeModuleObject
          (PyObject *name, PyObject *co, PyObject *pathname, PyObject
          *cpathname)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'  Like *note
     PyImport_ExecCodeModuleEx(): 500a, but the *note __cached__: 321.
     attribute of the module object is set to 'cpathname' if it is
     non-‘NULL’.  Of the three functions, this is the preferred one to
     use.

     Added in version 3.3.

     Cambiato nella versione 3.12: Setting *note __cached__: 321. is
     deprecated.  See *note ModuleSpec: 2255. for alternatives.

 -- C Funzione: *note PyObject: 5df.
          *PyImport_ExecCodeModuleWithPathnames (const char *name,
          PyObject *co, const char *pathname, const char *cpathname)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Like *note PyImport_ExecCodeModuleObject(): 500b,
     but 'name', 'pathname' and 'cpathname' are UTF-8 encoded strings.
     Attempts are also made to figure out what the value for 'pathname'
     should be from 'cpathname' if the former is set to ‘NULL’.

     Added in version 3.2.

     Cambiato nella versione 3.3: Uses ‘imp.source_from_cache()’ in
     calculating the source path if only the bytecode path is provided.

     Cambiato nella versione 3.12: No longer uses the removed ‘imp’
     module.

 -- C Funzione: long PyImport_GetMagicNumber ()
     ' Parte del *note ABI Stabile: 776.'  Return the magic number for
     Python bytecode files (a.k.a.  ‘.pyc’ file).  The magic number
     should be present in the first four bytes of the bytecode file, in
     little-endian byte order.  Returns ‘-1’ on error.

     Cambiato nella versione 3.3: Return value of ‘-1’ upon failure.

 -- C Funzione: const char *PyImport_GetMagicTag ()
     ' Parte del *note ABI Stabile: 776.'  Return the magic tag string
     for PEP 3147(1) format Python bytecode file names.  Keep in mind
     that the value at ‘sys.implementation.cache_tag’ is authoritative
     and should be used instead of this function.

     Added in version 3.2.

 -- C Funzione: *note PyObject: 5df. *PyImport_GetModuleDict ()
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Return the dictionary used for the module
     administration (a.k.a.  ‘sys.modules’).  Note that this is a
     per-interpreter variable.

 -- C Funzione: *note PyObject: 5df. *PyImport_GetModule (PyObject
          *name)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.8.'  Return the already imported
     module with the given name.  If the module has not been imported
     yet then returns ‘NULL’ but does not set an error.  Returns ‘NULL’
     and sets an error if the lookup failed.

     Added in version 3.7.

 -- C Funzione: *note PyObject: 5df. *PyImport_GetImporter (PyObject
          *path)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a finder object for a *note sys.path:
     3e4./‘pkg.__path__’ item 'path', possibly by fetching it from the
     *note sys.path_importer_cache: 7fb. dict.  If it wasn’t yet cached,
     traverse *note sys.path_hooks: 1226. until a hook is found that can
     handle the path item.  Return ‘None’ if no hook could; this tells
     our caller that the *note path based finder: 2430. could not find a
     finder for this path item.  Cache the result in *note
     sys.path_importer_cache: 7fb.  Return a new reference to the finder
     object.

 -- C Funzione: int PyImport_ImportFrozenModuleObject (PyObject *name)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Load a
     frozen module named 'name'.  Return ‘1’ for success, ‘0’ if the
     module is not found, and ‘-1’ with an exception set if the
     initialization failed.  To access the imported module on a
     successful load, use *note PyImport_ImportModule(): 3dc.  (Note the
     misnomer — this function would reload the module if it was already
     imported.)

     Added in version 3.3.

     Cambiato nella versione 3.4: The ‘__file__’ attribute is no longer
     set on the module.

 -- C Funzione: int PyImport_ImportFrozenModule (const char *name)
     ' Parte del *note ABI Stabile: 776.'  Similar to *note
     PyImport_ImportFrozenModuleObject(): 5010, but the name is a UTF-8
     encoded string instead of a Unicode object.

 -- C Struct: struct _frozen

     This is the structure type definition for frozen module
     descriptors, as generated by the ‘freeze’ utility (see
     ‘Tools/freeze/’ in the Python source distribution).  Its
     definition, found in ‘Include/import.h’, is:

          struct _frozen {
              const char *name;
              const unsigned char *code;
              int size;
              bool is_package;
          };

     Cambiato nella versione 3.11: The new ‘is_package’ field indicates
     whether the module is a package or not.  This replaces setting the
     ‘size’ field to a negative value.

 -- C Variabile: const struct *note _frozen: 97a.
          *PyImport_FrozenModules

     This pointer is initialized to point to an array of *note _frozen:
     97a. records, terminated by one whose members are all ‘NULL’ or
     zero.  When a frozen module is imported, it is searched in this
     table.  Third-party code could play tricks with this to provide a
     dynamically created collection of frozen modules.

 -- C Funzione: int PyImport_AppendInittab (const char *name, PyObject
          *(*initfunc)(void))
     ' Parte del *note ABI Stabile: 776.'  Add a single module to the
     existing table of built-in modules.  This is a convenience wrapper
     around *note PyImport_ExtendInittab(): 1b05, returning ‘-1’ if the
     table could not be extended.  The new module can be imported by the
     name 'name', and uses the function 'initfunc' as the initialization
     function called on the first attempted import.  This should be
     called before *note Py_Initialize(): 460.

 -- C Struct: struct _inittab

     Structure describing a single entry in the list of built-in
     modules.  Programs which embed Python may use an array of these
     structures in conjunction with *note PyImport_ExtendInittab():
     1b05. to provide additional built-in modules.  The structure
     consists of two members:

      -- C Membro: const char *name

          The module name, as an ASCII encoded string.

      -- C Membro: *note PyObject: 5df. *(*initfunc)(void)

          Initialization function for a module built into the
          interpreter.

 -- C Funzione: int PyImport_ExtendInittab (struct _inittab *newtab)

     Add a collection of modules to the table of built-in modules.  The
     'newtab' array must end with a sentinel entry which contains ‘NULL’
     for the *note name: 5204. field; failure to provide the sentinel
     value can result in a memory fault.  Returns ‘0’ on success or ‘-1’
     if insufficient memory could be allocated to extend the internal
     table.  In the event of failure, no modules are added to the
     internal table.  This must be called before *note Py_Initialize():
     460.

     If Python is initialized multiple times, *note
     PyImport_AppendInittab(): 1b04. or *note PyImport_ExtendInittab():
     1b05. must be called before each Python initialization.

 -- C Variabile: struct *note _inittab: 5203. *PyImport_Inittab

     The table of built-in modules used by Python initialization.  Do
     not use this directly; use *note PyImport_AppendInittab(): 1b04.
     and *note PyImport_ExtendInittab(): 1b05. instead.

 -- C Funzione: *note PyObject: 5df. *PyImport_ImportModuleAttr
          (PyObject *mod_name, PyObject *attr_name)
     'Valore di ritorno: Nuovo riferimento.'  Import the module
     'mod_name' and get its attribute 'attr_name'.

     Names must be Python *note str: 169. objects.

     Helper function combining *note PyImport_Import(): 1603. and *note
     PyObject_GetAttr(): 5ee.  For example, it can raise *note
     ImportError: 65b. if the module is not found, and *note
     AttributeError: 5f0. if the attribute doesn’t exist.

     Added in version 3.14.

 -- C Funzione: *note PyObject: 5df. *PyImport_ImportModuleAttrString
          (const char *mod_name, const char *attr_name)
     'Valore di ritorno: Nuovo riferimento.'  Similar to *note
     PyImport_ImportModuleAttr(): 396, but names are UTF-8 encoded
     strings instead of Python *note str: 169. objects.

     Added in version 3.14.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3147/


File: python.info,  Node: Data marshalling support,  Next: Parsing arguments and building values,  Prev: Importing Modules<2>,  Up: Utilities<2>

7.7.5 Data marshalling support
------------------------------

These routines allow C code to work with serialized objects using the
same data format as the *note marshal: 91. module.  There are functions
to write data into the serialization format, and additional functions
that can be used to read the data back.  Files used to store marshalled
data must be opened in binary mode.

Numeric values are stored with the least significant byte first.

The module supports several versions of the data format; see the *note
Python module documentation: 91. for details.

 -- C Macro: Py_MARSHAL_VERSION

     The current format version.  See *note marshal.version: 2d28.

 -- C Funzione: void PyMarshal_WriteLongToFile (long value, FILE *file,
          int version)

     Marshal a long integer, 'value', to 'file'.  This will only write
     the least-significant 32 bits of 'value'; regardless of the size of
     the native long type.  'version' indicates the file format.

     This function can fail, in which case it sets the error indicator.
     Use *note PyErr_Occurred(): 1c97. to check for that.

 -- C Funzione: void PyMarshal_WriteObjectToFile (PyObject *value, FILE
          *file, int version)

     Marshal a Python object, 'value', to 'file'.  'version' indicates
     the file format.

     This function can fail, in which case it sets the error indicator.
     Use *note PyErr_Occurred(): 1c97. to check for that.

 -- C Funzione: *note PyObject: 5df. *PyMarshal_WriteObjectToString
          (PyObject *value, int version)
     'Valore di ritorno: Nuovo riferimento.'  Return a bytes object
     containing the marshalled representation of 'value'.  'version'
     indicates the file format.

The following functions allow marshalled values to be read back in.

 -- C Funzione: long PyMarshal_ReadLongFromFile (FILE *file)

     Return a C long from the data stream in a FILE* opened for reading.
     Only a 32-bit value can be read in using this function, regardless
     of the native size of long.

     On error, sets the appropriate exception (*note EOFError: 14e1.)
     and returns ‘-1’.

 -- C Funzione: int PyMarshal_ReadShortFromFile (FILE *file)

     Return a C short from the data stream in a FILE* opened for
     reading.  Only a 16-bit value can be read in using this function,
     regardless of the native size of short.

     On error, sets the appropriate exception (*note EOFError: 14e1.)
     and returns ‘-1’.

 -- C Funzione: *note PyObject: 5df. *PyMarshal_ReadObjectFromFile (FILE
          *file)
     'Valore di ritorno: Nuovo riferimento.'  Return a Python object
     from the data stream in a FILE* opened for reading.

     On error, sets the appropriate exception (*note EOFError: 14e1,
     *note ValueError: 2ec. or *note TypeError: 198.) and returns
     ‘NULL’.

 -- C Funzione: *note PyObject: 5df. *PyMarshal_ReadLastObjectFromFile
          (FILE *file)
     'Valore di ritorno: Nuovo riferimento.'  Return a Python object
     from the data stream in a FILE* opened for reading.  Unlike *note
     PyMarshal_ReadObjectFromFile(): 520d, this function assumes that no
     further objects will be read from the file, allowing it to
     aggressively load file data into memory so that the
     de-serialization can operate from data in memory rather than
     reading a byte at a time from the file.  Only use this variant if
     you are certain that you won’t be reading anything else from the
     file.

     On error, sets the appropriate exception (*note EOFError: 14e1,
     *note ValueError: 2ec. or *note TypeError: 198.) and returns
     ‘NULL’.

 -- C Funzione: *note PyObject: 5df. *PyMarshal_ReadObjectFromString
          (const char *data, Py_ssize_t len)
     'Valore di ritorno: Nuovo riferimento.'  Return a Python object
     from the data stream in a byte buffer containing 'len' bytes
     pointed to by 'data'.

     On error, sets the appropriate exception (*note EOFError: 14e1,
     *note ValueError: 2ec. or *note TypeError: 198.) and returns
     ‘NULL’.


File: python.info,  Node: Parsing arguments and building values,  Next: String conversion and formatting,  Prev: Data marshalling support,  Up: Utilities<2>

7.7.6 Parsing arguments and building values
-------------------------------------------

These functions are useful when creating your own extension functions
and methods.  Additional information and examples are available in *note
Extending and Embedding the Python Interpreter: 1fa5.

The first three of these functions described, *note PyArg_ParseTuple():
3c1, *note PyArg_ParseTupleAndKeywords(): 624, and *note PyArg_Parse():
17f6, all use 'format strings' which are used to tell the function about
the expected arguments.  The format strings use the same syntax for each
of these functions.

* Menu:

* Parsing arguments: Parsing arguments<2>.
* Building values::


File: python.info,  Node: Parsing arguments<2>,  Next: Building values,  Up: Parsing arguments and building values

7.7.6.1 Parsing arguments
.........................

A format string consists of zero or more «format units.» A format unit
describes one Python object; it is usually a single character or a
parenthesized sequence of format units.  With a few exceptions, a format
unit that is not a parenthesized sequence normally corresponds to a
single address argument to these functions.  In the following
description, the quoted form is the format unit; the entry in (round)
parentheses is the Python object type that matches the format unit; and
the entry in [square] brackets is the type of the C variable(s) whose
address should be passed.

* Menu:

* Strings and buffers::
* Numbers::
* Other objects::
* API Functions::


File: python.info,  Node: Strings and buffers,  Next: Numbers,  Up: Parsing arguments<2>

7.7.6.2 Strings and buffers
...........................

     Nota: On Python 3.12 and older, the macro ‘PY_SSIZE_T_CLEAN’ must
     be defined before including ‘Python.h’ to use all ‘#’ variants of
     formats (‘s#’, ‘y#’, etc.)  explained below.  This is not necessary
     on Python 3.13 and later.

These formats allow accessing an object as a contiguous chunk of memory.
You don’t have to provide raw storage for the returned unicode or bytes
area.

Unless otherwise stated, buffers are not NUL-terminated.

There are three ways strings and buffers can be converted to C:

   * Formats such as ‘y*’ and ‘s*’ fill a *note Py_buffer: 95d.
     structure.  This locks the underlying buffer so that the caller can
     subsequently use the buffer even inside a *note
     Py_BEGIN_ALLOW_THREADS: 4ea6. block without the risk of mutable
     data being resized or destroyed.  As a result, 'you have to call'
     *note PyBuffer_Release(): 63b. after you have finished processing
     the data (or in any early abort case).

   * The ‘es’, ‘es#’, ‘et’ and ‘et#’ formats allocate the result buffer.
     'You have to call' *note PyMem_Free(): 1649. after you have
     finished processing the data (or in any early abort case).

   * Other formats take a *note str: 169. or a read-only *note
     bytes-like object: 193, such as *note bytes: 192, and provide a
     ‘const char *’ pointer to its buffer.  In this case the buffer is
     «borrowed»: it is managed by the corresponding Python object, and
     shares the lifetime of this object.  You won’t have to release any
     memory yourself.

     To ensure that the underlying buffer may be safely borrowed, the
     object’s *note PyBufferProcs.bf_releasebuffer: 968. field must be
     ‘NULL’.  This disallows common mutable objects such as *note
     bytearray: 344, but also some read-only objects such as *note
     memoryview: 165. of *note bytes: 192.

     Besides this ‘bf_releasebuffer’ requirement, there is no check to
     verify whether the input object is immutable (e.g.  whether it
     would honor a request for a writable buffer, or whether another
     thread can mutate the data).

‘s’ (*note str: 169.) [const char *]

     Convert a Unicode object to a C pointer to a character string.  A
     pointer to an existing string is stored in the character pointer
     variable whose address you pass.  The C string is NUL-terminated.
     The Python string must not contain embedded null code points; if it
     does, a *note ValueError: 2ec. exception is raised.  Unicode
     objects are converted to C strings using ‘'utf-8'’ encoding.  If
     this conversion fails, a *note UnicodeError: 462. is raised.

          Nota: This format does not accept *note bytes-like objects:
          193.  If you want to accept filesystem paths and convert them
          to C character strings, it is preferable to use the ‘O&’
          format with *note PyUnicode_FSConverter(): f17. as
          'converter'.

     Cambiato nella versione 3.5: Previously, *note TypeError: 198. was
     raised when embedded null code points were encountered in the
     Python string.

‘s*’ (*note str: 169. or *note bytes-like object: 193.) [Py_buffer]

     This format accepts Unicode objects as well as bytes-like objects.
     It fills a *note Py_buffer: 95d. structure provided by the caller.
     In this case the resulting C string may contain embedded NUL bytes.
     Unicode objects are converted to C strings using ‘'utf-8'’
     encoding.

‘s#’ (*note str: 169, read-only *note bytes-like object: 193.) [const char *, *note Py_ssize_t: c57.]

     Like ‘s*’, except that it provides a *note borrowed buffer: 3d6.
     The result is stored into two C variables, the first one a pointer
     to a C string, the second one its length.  The string may contain
     embedded null bytes.  Unicode objects are converted to C strings
     using ‘'utf-8'’ encoding.

‘z’ (*note str: 169. or ‘None’) [const char *]

     Like ‘s’, but the Python object may also be ‘None’, in which case
     the C pointer is set to ‘NULL’.

‘z*’ (*note str: 169, *note bytes-like object: 193. or ‘None’) [Py_buffer]

     Like ‘s*’, but the Python object may also be ‘None’, in which case
     the ‘buf’ member of the *note Py_buffer: 95d. structure is set to
     ‘NULL’.

‘z#’ (*note str: 169, read-only *note bytes-like object: 193. or ‘None’) [const char *, *note Py_ssize_t: c57.]

     Like ‘s#’, but the Python object may also be ‘None’, in which case
     the C pointer is set to ‘NULL’.

‘y’ (read-only *note bytes-like object: 193.) [const char *]

     This format converts a bytes-like object to a C pointer to a *note
     borrowed: 3d6. character string; it does not accept Unicode
     objects.  The bytes buffer must not contain embedded null bytes; if
     it does, a *note ValueError: 2ec. exception is raised.

     Cambiato nella versione 3.5: Previously, *note TypeError: 198. was
     raised when embedded null bytes were encountered in the bytes
     buffer.

‘y*’ (*note bytes-like object: 193.) [Py_buffer]

     This variant on ‘s*’ doesn’t accept Unicode objects, only
     bytes-like objects.  'This is the recommended way to accept binary
     data.'

‘y#’ (read-only *note bytes-like object: 193.) [const char *, *note Py_ssize_t: c57.]

     This variant on ‘s#’ doesn’t accept Unicode objects, only
     bytes-like objects.

‘S’ (*note bytes: 192.) [PyBytesObject *]

     Requires that the Python object is a *note bytes: 192. object,
     without attempting any conversion.  Raises *note TypeError: 198. if
     the object is not a bytes object.  The C variable may also be
     declared as *note PyObject: 5df.*.

‘Y’ (*note bytearray: 344.) [PyByteArrayObject *]

     Requires that the Python object is a *note bytearray: 344. object,
     without attempting any conversion.  Raises *note TypeError: 198. if
     the object is not a *note bytearray: 344. object.  The C variable
     may also be declared as *note PyObject: 5df.*.

‘U’ (*note str: 169.) [PyObject *]

     Requires that the Python object is a Unicode object, without
     attempting any conversion.  Raises *note TypeError: 198. if the
     object is not a Unicode object.  The C variable may also be
     declared as *note PyObject: 5df.*.

‘w*’ (read-write *note bytes-like object: 193.) [Py_buffer]

     This format accepts any object which implements the read-write
     buffer interface.  It fills a *note Py_buffer: 95d. structure
     provided by the caller.  The buffer may contain embedded null
     bytes.  The caller has to call *note PyBuffer_Release(): 63b. when
     it is done with the buffer.

‘es’ (*note str: 169.) [const char *encoding, char **buffer]

     This variant on ‘s’ is used for encoding Unicode into a character
     buffer.  It only works for encoded data without embedded NUL bytes.

     This format requires two arguments.  The first is only used as
     input, and must be a const char* which points to the name of an
     encoding as a NUL-terminated string, or ‘NULL’, in which case
     ‘'utf-8'’ encoding is used.  An exception is raised if the named
     encoding is not known to Python.  The second argument must be a
     char**; the value of the pointer it references will be set to a
     buffer with the contents of the argument text.  The text will be
     encoded in the encoding specified by the first argument.

     *note PyArg_ParseTuple(): 3c1. will allocate a buffer of the needed
     size, copy the encoded data into this buffer and adjust '*buffer'
     to reference the newly allocated storage.  The caller is
     responsible for calling *note PyMem_Free(): 1649. to free the
     allocated buffer after use.

‘et’ (*note str: 169, *note bytes: 192. or *note bytearray: 344.) [const char *encoding, char **buffer]

     Same as ‘es’ except that byte string objects are passed through
     without recoding them.  Instead, the implementation assumes that
     the byte string object uses the encoding passed in as parameter.

‘es#’ (*note str: 169.) [const char *encoding, char **buffer, *note Py_ssize_t: c57. *buffer_length]

     This variant on ‘s#’ is used for encoding Unicode into a character
     buffer.  Unlike the ‘es’ format, this variant allows input data
     which contains NUL characters.

     It requires three arguments.  The first is only used as input, and
     must be a const char* which points to the name of an encoding as a
     NUL-terminated string, or ‘NULL’, in which case ‘'utf-8'’ encoding
     is used.  An exception is raised if the named encoding is not known
     to Python.  The second argument must be a char**; the value of the
     pointer it references will be set to a buffer with the contents of
     the argument text.  The text will be encoded in the encoding
     specified by the first argument.  The third argument must be a
     pointer to an integer; the referenced integer will be set to the
     number of bytes in the output buffer.

     There are two modes of operation:

     If '*buffer' points a ‘NULL’ pointer, the function will allocate a
     buffer of the needed size, copy the encoded data into this buffer
     and set '*buffer' to reference the newly allocated storage.  The
     caller is responsible for calling *note PyMem_Free(): 1649. to free
     the allocated buffer after usage.

     If '*buffer' points to a non-‘NULL’ pointer (an already allocated
     buffer), *note PyArg_ParseTuple(): 3c1. will use this location as
     the buffer and interpret the initial value of '*buffer_length' as
     the buffer size.  It will then copy the encoded data into the
     buffer and NUL-terminate it.  If the buffer is not large enough, a
     *note ValueError: 2ec. will be set.

     In both cases, '*buffer_length' is set to the length of the encoded
     data without the trailing NUL byte.

‘et#’ (*note str: 169, *note bytes: 192. or *note bytearray: 344.) [const char *encoding, char **buffer, *note Py_ssize_t: c57. *buffer_length]

     Same as ‘es#’ except that byte string objects are passed through
     without recoding them.  Instead, the implementation assumes that
     the byte string object uses the encoding passed in as parameter.

Cambiato nella versione 3.12: ‘u’, ‘u#’, ‘Z’, and ‘Z#’ are removed
because they used a legacy ‘Py_UNICODE*’ representation.


File: python.info,  Node: Numbers,  Next: Other objects,  Prev: Strings and buffers,  Up: Parsing arguments<2>

7.7.6.3 Numbers
...............

These formats allow representing Python numbers or single characters as
C numbers.  Formats that require *note int: 19b, *note float: 196. or
*note complex: 197. can also use the corresponding special methods *note
__index__(): 19e, *note __float__(): bc3. or *note __complex__(): 7fe.
to convert the Python object to the required type.

For signed integer formats, *note OverflowError: a83. is raised if the
value is out of range for the C type.  For unsigned integer formats, no
range checking is done — the most significant bits are silently
truncated when the receiving field is too small to receive the value.

‘b’ (*note int: 19b.) [unsigned char]

     Convert a nonnegative Python integer to an unsigned tiny integer,
     stored in a C unsigned char.

‘B’ (*note int: 19b.) [unsigned char]

     Convert a Python integer to a tiny integer without overflow
     checking, stored in a C unsigned char.

‘h’ (*note int: 19b.) [short int]

     Convert a Python integer to a C short int.

‘H’ (*note int: 19b.) [unsigned short int]

     Convert a Python integer to a C unsigned short int, without
     overflow checking.

‘i’ (*note int: 19b.) [int]

     Convert a Python integer to a plain C int.

‘I’ (*note int: 19b.) [unsigned int]

     Convert a Python integer to a C unsigned int, without overflow
     checking.

‘l’ (*note int: 19b.) [long int]

     Convert a Python integer to a C long int.

‘k’ (*note int: 19b.) [unsigned long]

     Convert a Python integer to a C unsigned long without overflow
     checking.

     Cambiato nella versione 3.14: Use *note __index__(): 19e. if
     available.

‘L’ (*note int: 19b.) [long long]

     Convert a Python integer to a C long long.

‘K’ (*note int: 19b.) [unsigned long long]

     Convert a Python integer to a C unsigned long long without overflow
     checking.

     Cambiato nella versione 3.14: Use *note __index__(): 19e. if
     available.

‘n’ (*note int: 19b.) [*note Py_ssize_t: c57.]

     Convert a Python integer to a C *note Py_ssize_t: c57.

‘c’ (*note bytes: 192. or *note bytearray: 344. of length 1) [char]

     Convert a Python byte, represented as a *note bytes: 192. or *note
     bytearray: 344. object of length 1, to a C char.

     Cambiato nella versione 3.3: Allow *note bytearray: 344. objects.

‘C’ (*note str: 169. of length 1) [int]

     Convert a Python character, represented as a *note str: 169. object
     of length 1, to a C int.

‘f’ (*note float: 196.) [float]

     Convert a Python floating-point number to a C float.

‘d’ (*note float: 196.) [double]

     Convert a Python floating-point number to a C double.

‘D’ (*note complex: 197.) [Py_complex]

     Convert a Python complex number to a C *note Py_complex: 5215.
     structure.


File: python.info,  Node: Other objects,  Next: API Functions,  Prev: Numbers,  Up: Parsing arguments<2>

7.7.6.4 Other objects
.....................

‘O’ (object) [PyObject *]

     Store a Python object (without any conversion) in a C object
     pointer.  The C program thus receives the actual object that was
     passed.  A new *note strong reference: 5e2. to the object is not
     created (i.e.  its reference count is not increased).  The pointer
     stored is not ‘NULL’.

‘O!’ (object) ['typeobject', PyObject *]

     Store a Python object in a C object pointer.  This is similar to
     ‘O’, but takes two C arguments: the first is the address of a
     Python type object, the second is the address of the C variable (of
     type *note PyObject: 5df.*) into which the object pointer is
     stored.  If the Python object does not have the required type,
     *note TypeError: 198. is raised.

‘O&’ (object) ['converter', 'address']

     Convert a Python object to a C variable through a 'converter'
     function.  This takes two arguments: the first is a function, the
     second is the address of a C variable (of arbitrary type),
     converted to void*.  The 'converter' function in turn is called as
     follows:

          status = converter(object, address);

     where 'object' is the Python object to be converted and 'address'
     is the void* argument that was passed to the ‘PyArg_Parse*’
     function.  The returned 'status' should be ‘1’ for a successful
     conversion and ‘0’ if the conversion has failed.  When the
     conversion fails, the 'converter' function should raise an
     exception and leave the content of 'address' unmodified.

     If the 'converter' returns ‘Py_CLEANUP_SUPPORTED’, it may get
     called a second time if the argument parsing eventually fails,
     giving the converter a chance to release any memory that it had
     already allocated.  In this second call, the 'object' parameter
     will be ‘NULL’; 'address' will have the same value as in the
     original call.

     Examples of converters: *note PyUnicode_FSConverter(): f17. and
     *note PyUnicode_FSDecoder(): 798.

     Cambiato nella versione 3.1: ‘Py_CLEANUP_SUPPORTED’ was added.

‘p’ (*note bool: 3c3.) [int]

     Tests the value passed in for truth (a boolean 'p'redicate) and
     converts the result to its equivalent C true/false integer value.
     Sets the int to ‘1’ if the expression was true and ‘0’ if it was
     false.  This accepts any valid Python value.  See *note Test del
     Valore di Verità: 1840. for more information about how Python tests
     values for truth.

     Added in version 3.3.

‘(items)’ (sequence) ['matching-items']

     The object must be a Python sequence (except *note str: 169, *note
     bytes: 192. or *note bytearray: 344.) whose length is the number of
     format units in 'items'.  The C arguments must correspond to the
     individual format units in 'items'.  Format units for sequences may
     be nested.

     If 'items' contains format units which store a *note borrowed
     buffer: 3d6. (‘s’, ‘s#’, ‘z’, ‘z#’, ‘y’, or ‘y#’) or a *note
     borrowed reference: 3d7. (‘S’, ‘Y’, ‘U’, ‘O’, or ‘O!’), the object
     must be a Python tuple.  The 'converter' for the ‘O&’ format unit
     in 'items' must not store a borrowed buffer or a borrowed
     reference.

     Cambiato nella versione 3.14: *note str: 169. and *note bytearray:
     344. objects no longer accepted as a sequence.

     Deprecato dalla versione 3.14: Non-tuple sequences are deprecated
     if 'items' contains format units which store a borrowed buffer or a
     borrowed reference.

A few other characters have a meaning in a format string.  These may not
occur inside nested parentheses.  They are:

‘|’

     Indicates that the remaining arguments in the Python argument list
     are optional.  The C variables corresponding to optional arguments
     should be initialized to their default value — when an optional
     argument is not specified, *note PyArg_ParseTuple(): 3c1. does not
     touch the contents of the corresponding C variable(s).

‘$’

     *note PyArg_ParseTupleAndKeywords(): 624. only: Indicates that the
     remaining arguments in the Python argument list are keyword-only.
     Currently, all keyword-only arguments must also be optional
     arguments, so ‘|’ must always be specified before ‘$’ in the format
     string.

     Added in version 3.3.

‘:’

     The list of format units ends here; the string after the colon is
     used as the function name in error messages (the «associated value»
     of the exception that *note PyArg_ParseTuple(): 3c1. raises).

‘;’

     The list of format units ends here; the string after the semicolon
     is used as the error message 'instead' of the default error
     message.  ‘:’ and ‘;’ mutually exclude each other.

Note that any Python object references which are provided to the caller
are 'borrowed' references; do not release them (i.e.  do not decrement
their reference count)!

Additional arguments passed to these functions must be addresses of
variables whose type is determined by the format string; these are used
to store values from the input tuple.  There are a few cases, as
described in the list of format units above, where these parameters are
used as input values; they should match what is specified for the
corresponding format unit in that case.

For the conversion to succeed, the 'arg' object must match the format
and the format must be exhausted.  On success, the ‘PyArg_Parse*’
functions return true, otherwise they return false and raise an
appropriate exception.  When the ‘PyArg_Parse*’ functions fail due to
conversion failure in one of the format units, the variables at the
addresses corresponding to that and the following format units are left
untouched.


File: python.info,  Node: API Functions,  Prev: Other objects,  Up: Parsing arguments<2>

7.7.6.5 API Functions
.....................

 -- C Funzione: int PyArg_ParseTuple (PyObject *args, const char
          *format, ...)
     ' Parte del *note ABI Stabile: 776.'  Parse the parameters of a
     function that takes only positional parameters into local
     variables.  Returns true on success; on failure, it returns false
     and raises the appropriate exception.

 -- C Funzione: int PyArg_VaParse (PyObject *args, const char *format,
          va_list vargs)
     ' Parte del *note ABI Stabile: 776.'  Identical to *note
     PyArg_ParseTuple(): 3c1, except that it accepts a va_list rather
     than a variable number of arguments.

 -- C Funzione: int PyArg_ParseTupleAndKeywords (PyObject *args,
          PyObject *kw, const char *format, char *const *keywords, ...)
     ' Parte del *note ABI Stabile: 776.'  Parse the parameters of a
     function that takes both positional and keyword parameters into
     local variables.  The 'keywords' argument is a ‘NULL’-terminated
     array of keyword parameter names specified as null-terminated ASCII
     or UTF-8 encoded C strings.  Empty names denote *note
     positional-only parameters: c7a.  Returns true on success; on
     failure, it returns false and raises the appropriate exception.

          Nota: The 'keywords' parameter declaration is char *const* in
          C and const char *const* in C++.  This can be overridden with
          the *note PY_CXX_CONST: 626. macro.

     Cambiato nella versione 3.6: Added support for *note
     positional-only parameters: c7a.

     Cambiato nella versione 3.13: The 'keywords' parameter has now type
     char *const* in C and const char *const* in C++, instead of char**.
     Added support for non-ASCII keyword parameter names.

 -- C Funzione: int PyArg_VaParseTupleAndKeywords (PyObject *args,
          PyObject *kw, const char *format, char *const *keywords,
          va_list vargs)
     ' Parte del *note ABI Stabile: 776.'  Identical to *note
     PyArg_ParseTupleAndKeywords(): 624, except that it accepts a
     va_list rather than a variable number of arguments.

 -- C Funzione: int PyArg_ValidateKeywordArguments (PyObject*)
     ' Parte del *note ABI Stabile: 776.'  Ensure that the keys in the
     keywords argument dictionary are strings.  This is only needed if
     *note PyArg_ParseTupleAndKeywords(): 624. is not used, since the
     latter already does this check.

     Added in version 3.2.

 -- C Funzione: int PyArg_Parse (PyObject *args, const char *format,
          ...)
     ' Parte del *note ABI Stabile: 776.'  Parse the parameter of a
     function that takes a single positional parameter into a local
     variable.  Returns true on success; on failure, it returns false
     and raises the appropriate exception.

     Example:

          // Function using METH_O calling convention
          static PyObject*
          my_function(PyObject *module, PyObject *arg)
          {
              int value;
              if (!PyArg_Parse(arg, "i:my_function", &value)) {
                  return NULL;
              }
              // ... use value ...
          }

 -- C Funzione: int PyArg_UnpackTuple (PyObject *args, const char *name,
          Py_ssize_t min, Py_ssize_t max, ...)
     ' Parte del *note ABI Stabile: 776.'  A simpler form of parameter
     retrieval which does not use a format string to specify the types
     of the arguments.  Functions which use this method to retrieve
     their parameters should be declared as *note METH_VARARGS: 170f. in
     function or method tables.  The tuple containing the actual
     parameters should be passed as 'args'; it must actually be a tuple.
     The length of the tuple must be at least 'min' and no more than
     'max'; 'min' and 'max' may be equal.  Additional arguments must be
     passed to the function, each of which should be a pointer to a
     *note PyObject: 5df.* variable; these will be filled in with the
     values from 'args'; they will contain *note borrowed references:
     3d7.  The variables which correspond to optional parameters not
     given by 'args' will not be filled in; these should be initialized
     by the caller.  This function returns true on success and false if
     'args' is not a tuple or contains the wrong number of elements; an
     exception will be set if there was a failure.

     This is an example of the use of this function, taken from the
     sources for the ‘_weakref’ helper module for weak references:

          static PyObject *
          weakref_ref(PyObject *self, PyObject *args)
          {
              PyObject *object;
              PyObject *callback = NULL;
              PyObject *result = NULL;

              if (PyArg_UnpackTuple(args, "ref", 1, 2, &object, &callback)) {
                  result = PyWeakref_NewRef(object, callback);
              }
              return result;
          }

     The call to *note PyArg_UnpackTuple(): 170d. in this example is
     entirely equivalent to this call to *note PyArg_ParseTuple(): 3c1.:

          PyArg_ParseTuple(args, "O|O:ref", &object, &callback)

 -- C Macro: PY_CXX_CONST

     The value to be inserted, if any, before char *const* in the
     'keywords' parameter declaration of *note
     PyArg_ParseTupleAndKeywords(): 624. and *note
     PyArg_VaParseTupleAndKeywords(): 625.  Default empty for C and
     ‘const’ for C++ (const char *const*).  To override, define it to
     the desired value before including ‘Python.h’.

     Added in version 3.13.


File: python.info,  Node: Building values,  Prev: Parsing arguments<2>,  Up: Parsing arguments and building values

7.7.6.6 Building values
.......................

 -- C Funzione: *note PyObject: 5df. *Py_BuildValue (const char *format,
          ...)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a new value based on a format string similar
     to those accepted by the ‘PyArg_Parse*’ family of functions and a
     sequence of values.  Returns the value or ‘NULL’ in the case of an
     error; an exception will be raised if ‘NULL’ is returned.

     *note Py_BuildValue(): 3c2. does not always build a tuple.  It
     builds a tuple only if its format string contains two or more
     format units.  If the format string is empty, it returns ‘None’; if
     it contains exactly one format unit, it returns whatever object is
     described by that format unit.  To force it to return a tuple of
     size 0 or one, parenthesize the format string.

     When memory buffers are passed as parameters to supply data to
     build objects, as for the ‘s’ and ‘s#’ formats, the required data
     is copied.  Buffers provided by the caller are never referenced by
     the objects created by *note Py_BuildValue(): 3c2.  In other words,
     if your code invokes ‘malloc()’ and passes the allocated memory to
     *note Py_BuildValue(): 3c2, your code is responsible for calling
     ‘free()’ for that memory once *note Py_BuildValue(): 3c2. returns.

     In the following description, the quoted form is the format unit;
     the entry in (round) parentheses is the Python object type that the
     format unit will return; and the entry in [square] brackets is the
     type of the C value(s) to be passed.

     The characters space, tab, colon and comma are ignored in format
     strings (but not within format units such as ‘s#’).  This can be
     used to make long format strings a tad more readable.

     ‘s’ (*note str: 169. or ‘None’) [const char *]

          Convert a null-terminated C string to a Python *note str: 169.
          object using ‘'utf-8'’ encoding.  If the C string pointer is
          ‘NULL’, ‘None’ is used.

     ‘s#’ (*note str: 169. or ‘None’) [const char *, *note Py_ssize_t: c57.]

          Convert a C string and its length to a Python *note str: 169.
          object using ‘'utf-8'’ encoding.  If the C string pointer is
          ‘NULL’, the length is ignored and ‘None’ is returned.

     ‘y’ (*note bytes: 192.) [const char *]

          This converts a C string to a Python *note bytes: 192. object.
          If the C string pointer is ‘NULL’, ‘None’ is returned.

     ‘y#’ (*note bytes: 192.) [const char *, *note Py_ssize_t: c57.]

          This converts a C string and its lengths to a Python object.
          If the C string pointer is ‘NULL’, ‘None’ is returned.

     ‘z’ (*note str: 169. or ‘None’) [const char *]

          Same as ‘s’.

     ‘z#’ (*note str: 169. or ‘None’) [const char *, *note Py_ssize_t: c57.]

          Same as ‘s#’.

     ‘u’ (*note str: 169.) [const wchar_t *]

          Convert a null-terminated ‘wchar_t’ buffer of Unicode (UTF-16
          or UCS-4) data to a Python Unicode object.  If the Unicode
          buffer pointer is ‘NULL’, ‘None’ is returned.

     ‘u#’ (*note str: 169.) [const wchar_t *, *note Py_ssize_t: c57.]

          Convert a Unicode (UTF-16 or UCS-4) data buffer and its length
          to a Python Unicode object.  If the Unicode buffer pointer is
          ‘NULL’, the length is ignored and ‘None’ is returned.

     ‘U’ (*note str: 169. or ‘None’) [const char *]

          Same as ‘s’.

     ‘U#’ (*note str: 169. or ‘None’) [const char *, *note Py_ssize_t: c57.]

          Same as ‘s#’.

     ‘i’ (*note int: 19b.) [int]

          Convert a plain C int to a Python integer object.

     ‘b’ (*note int: 19b.) [char]

          Convert a plain C char to a Python integer object.

     ‘h’ (*note int: 19b.) [short int]

          Convert a plain C short int to a Python integer object.

     ‘l’ (*note int: 19b.) [long int]

          Convert a C long int to a Python integer object.

     ‘B’ (*note int: 19b.) [unsigned char]

          Convert a C unsigned char to a Python integer object.

     ‘H’ (*note int: 19b.) [unsigned short int]

          Convert a C unsigned short int to a Python integer object.

     ‘I’ (*note int: 19b.) [unsigned int]

          Convert a C unsigned int to a Python integer object.

     ‘k’ (*note int: 19b.) [unsigned long]

          Convert a C unsigned long to a Python integer object.

     ‘L’ (*note int: 19b.) [long long]

          Convert a C long long to a Python integer object.

     ‘K’ (*note int: 19b.) [unsigned long long]

          Convert a C unsigned long long to a Python integer object.

     ‘n’ (*note int: 19b.) [*note Py_ssize_t: c57.]

          Convert a C *note Py_ssize_t: c57. to a Python integer.

     ‘p’ (*note bool: 3c3.) [int]

          Convert a C int to a Python *note bool: 3c3. object.

          Be aware that this format requires an ‘int’ argument.  Unlike
          most other contexts in C, variadic arguments are not coerced
          to a suitable type automatically.  You can convert another
          type (for example, a pointer or a float) to a suitable ‘int’
          value using ‘(x) ? 1 : 0’ or ‘!!x’.

          Added in version 3.14.

     ‘c’ (*note bytes: 192. of length 1) [char]

          Convert a C int representing a byte to a Python *note bytes:
          192. object of length 1.

     ‘C’ (*note str: 169. of length 1) [int]

          Convert a C int representing a character to Python *note str:
          169. object of length 1.

     ‘d’ (*note float: 196.) [double]

          Convert a C double to a Python floating-point number.

     ‘f’ (*note float: 196.) [float]

          Convert a C float to a Python floating-point number.

     ‘D’ (*note complex: 197.) [Py_complex *]

          Convert a C *note Py_complex: 5215. structure to a Python
          complex number.

     ‘O’ (object) [PyObject *]

          Pass a Python object untouched but create a new *note strong
          reference: 5e2. to it (i.e.  its reference count is
          incremented by one).  If the object passed in is a ‘NULL’
          pointer, it is assumed that this was caused because the call
          producing the argument found an error and set an exception.
          Therefore, *note Py_BuildValue(): 3c2. will return ‘NULL’ but
          won’t raise an exception.  If no exception has been raised
          yet, *note SystemError: 796. is set.

     ‘S’ (object) [PyObject *]

          Same as ‘O’.

     ‘N’ (object) [PyObject *]

          Same as ‘O’, except it doesn’t create a new *note strong
          reference: 5e2.  Useful when the object is created by a call
          to an object constructor in the argument list.

     ‘O&’ (object) ['converter', 'anything']

          Convert 'anything' to a Python object through a 'converter'
          function.  The function is called with 'anything' (which
          should be compatible with void*) as its argument and should
          return a «new» Python object, or ‘NULL’ if an error occurred.

     ‘(items)’ (*note tuple: 614.) ['matching-items']

          Convert a sequence of C values to a Python tuple with the same
          number of items.

     ‘[items]’ (*note list: 24d.) ['matching-items']

          Convert a sequence of C values to a Python list with the same
          number of items.

     ‘{items}’ (*note dict: 183.) ['matching-items']

          Convert a sequence of C values to a Python dictionary.  Each
          pair of consecutive C values adds one item to the dictionary,
          serving as key and value, respectively.

     If there is an error in the format string, the *note SystemError:
     796. exception is set and ‘NULL’ returned.

 -- C Funzione: *note PyObject: 5df. *Py_VaBuildValue (const char
          *format, va_list vargs)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Identical to *note Py_BuildValue(): 3c2, except
     that it accepts a va_list rather than a variable number of
     arguments.


File: python.info,  Node: String conversion and formatting,  Next: Character classification and conversion,  Prev: Parsing arguments and building values,  Up: Utilities<2>

7.7.7 String conversion and formatting
--------------------------------------

Functions for number conversion and formatted string output.

 -- C Funzione: int PyOS_snprintf (char *str, size_t size, const char
          *format, ...)
     ' Parte del *note ABI Stabile: 776.'  Output not more than 'size'
     bytes to 'str' according to the format string 'format' and the
     extra arguments.  See the Unix man page ‘snprintf(3)(1)’.

 -- C Funzione: int PyOS_vsnprintf (char *str, size_t size, const char
          *format, va_list va)
     ' Parte del *note ABI Stabile: 776.'  Output not more than 'size'
     bytes to 'str' according to the format string 'format' and the
     variable argument list 'va'.  Unix man page ‘vsnprintf(3)(2)’.

*note PyOS_snprintf(): 1710. and *note PyOS_vsnprintf(): 1711. wrap the
Standard C library functions ‘snprintf()’ and ‘vsnprintf()’.  Their
purpose is to guarantee consistent behavior in corner cases, which the
Standard C functions do not.

The wrappers ensure that ‘str[size-1]’ is always ‘'\0'’ upon return.
They never write more than 'size' bytes (including the trailing ‘'\0'’)
into str.  Both functions require that ‘str != NULL’, ‘size > 0’,
‘format != NULL’ and ‘size < INT_MAX’.  Note that this means there is no
equivalent to the C99 ‘n = snprintf(NULL, 0, ...)’ which would determine
the necessary buffer size.

The return value ('rv') for these functions should be interpreted as
follows:

   * When ‘0 <= rv < size’, the output conversion was successful and
     'rv' characters were written to 'str' (excluding the trailing
     ‘'\0'’ byte at ‘str[rv]’).

   * When ‘rv >= size’, the output conversion was truncated and a buffer
     with ‘rv + 1’ bytes would have been needed to succeed.
     ‘str[size-1]’ is ‘'\0'’ in this case.

   * When ‘rv < 0’, the output conversion failed and ‘str[size-1]’ is
     ‘'\0'’ in this case too, but the rest of 'str' is undefined.  The
     exact cause of the error depends on the underlying platform.

The following functions provide locale-independent string to number
conversions.

 -- C Funzione: unsigned long PyOS_strtoul (const char *str, char **ptr,
          int base)
     ' Parte del *note ABI Stabile: 776.'  Convert the initial part of
     the string in ‘str’ to an unsigned long value according to the
     given ‘base’, which must be between ‘2’ and ‘36’ inclusive, or be
     the special value ‘0’.

     Leading white space and case of characters are ignored.  If ‘base’
     is zero it looks for a leading ‘0b’, ‘0o’ or ‘0x’ to tell which
     base.  If these are absent it defaults to ‘10’.  Base must be 0 or
     between 2 and 36 (inclusive).  If ‘ptr’ is non-‘NULL’ it will
     contain a pointer to the end of the scan.

     If the converted value falls out of range of corresponding return
     type, range error occurs (‘errno’ is set to ‘ERANGE’) and
     ‘ULONG_MAX’ is returned.  If no conversion can be performed, ‘0’ is
     returned.

     See also the Unix man page ‘strtoul(3)(3)’.

     Added in version 3.2.

 -- C Funzione: long PyOS_strtol (const char *str, char **ptr, int base)
     ' Parte del *note ABI Stabile: 776.'  Convert the initial part of
     the string in ‘str’ to an long value according to the given ‘base’,
     which must be between ‘2’ and ‘36’ inclusive, or be the special
     value ‘0’.

     Same as *note PyOS_strtoul(): 505d, but return a long value instead
     and ‘LONG_MAX’ on overflows.

     See also the Unix man page ‘strtol(3)(4)’.

     Added in version 3.2.

 -- C Funzione: double PyOS_string_to_double (const char *s, char
          **endptr, PyObject *overflow_exception)
     ' Parte del *note ABI Stabile: 776.'  Convert a string ‘s’ to a
     double, raising a Python exception on failure.  The set of accepted
     strings corresponds to the set of strings accepted by Python’s
     *note float(): 196. constructor, except that ‘s’ must not have
     leading or trailing whitespace.  The conversion is independent of
     the current locale.

     If ‘endptr’ is ‘NULL’, convert the whole string.  Raise *note
     ValueError: 2ec. and return ‘-1.0’ if the string is not a valid
     representation of a floating-point number.

     If endptr is not ‘NULL’, convert as much of the string as possible
     and set ‘*endptr’ to point to the first unconverted character.  If
     no initial segment of the string is the valid representation of a
     floating-point number, set ‘*endptr’ to point to the beginning of
     the string, raise ValueError, and return ‘-1.0’.

     If ‘s’ represents a value that is too large to store in a float
     (for example, ‘"1e500"’ is such a string on many platforms) then if
     ‘overflow_exception’ is ‘NULL’ return ‘Py_INFINITY’ (with an
     appropriate sign) and don’t set any exception.  Otherwise,
     ‘overflow_exception’ must point to a Python exception object; raise
     that exception and return ‘-1.0’.  In both cases, set ‘*endptr’ to
     point to the first character after the converted value.

     If any other error occurs during the conversion (for example an
     out-of-memory error), set the appropriate Python exception and
     return ‘-1.0’.

     Added in version 3.1.

 -- C Funzione: char *PyOS_double_to_string (double val, char
          format_code, int precision, int flags, int *ptype)
     ' Parte del *note ABI Stabile: 776.'  Convert a double 'val' to a
     string using supplied 'format_code', 'precision', and 'flags'.

     'format_code' must be one of ‘'e'’, ‘'E'’, ‘'f'’, ‘'F'’, ‘'g'’,
     ‘'G'’ or ‘'r'’.  For ‘'r'’, the supplied 'precision' must be 0 and
     is ignored.  The ‘'r'’ format code specifies the standard *note
     repr(): 1c1. format.

     'flags' can be zero or more of the following values or-ed together:

      -- C Macro: Py_DTSF_SIGN

          Always precede the returned string with a sign character, even
          if 'val' is non-negative.

      -- C Macro: Py_DTSF_ADD_DOT_0

          Ensure that the returned string will not look like an integer.

      -- C Macro: Py_DTSF_ALT

          Apply «alternate» formatting rules.  See the documentation for
          the *note PyOS_snprintf(): 1710. ‘'#'’ specifier for details.

      -- C Macro: Py_DTSF_NO_NEG_0

          Negative zero is converted to positive zero.

          Added in version 3.11.

     If 'ptype' is non-‘NULL’, then the value it points to will be set
     to one of the following constants depending on the type of 'val':

     '*ptype'                                               type of 'val'
                                                            
     --------------------------------------------------------------------------------------------------------------
                                                            
      -- C Macro: Py_DTST_FINITE                            finite number
                                                            
                                                            
      -- C Macro: Py_DTST_INFINITE                          infinite number
                                                            
                                                            
      -- C Macro: Py_DTST_NAN                               not a number
                                                            

     The return value is a pointer to 'buffer' with the converted string
     or ‘NULL’ if the conversion failed.  The caller is responsible for
     freeing the returned string by calling *note PyMem_Free(): 1649.

     Added in version 3.1.

 -- C Funzione: int PyOS_mystricmp (const char *str1, const char *str2)
 -- C Funzione: int PyOS_mystrnicmp (const char *str1, const char *str2,
          Py_ssize_t size)
     ' Parte del *note ABI Stabile: 776.'  Case insensitive comparison
     of strings.  These functions work almost identically to ‘strcmp()’
     and ‘strncmp()’ (respectively), except that they ignore the case of
     ASCII characters.

     Return ‘0’ if the strings are equal, a negative value if 'str1'
     sorts lexicographically before 'str2', or a positive value if it
     sorts after.

     In the 'str1' or 'str2' arguments, a NUL byte marks the end of the
     string.  For ‘PyOS_mystrnicmp()’, the 'size' argument gives the
     maximum size of the string, as if NUL was present at the index
     given by 'size'.

     These functions do not use the locale.

 -- C Funzione: int PyOS_stricmp (const char *str1, const char *str2)
 -- C Funzione: int PyOS_strnicmp (const char *str1, const char *str2,
          Py_ssize_t size)

     Case insensitive comparison of strings.

     On Windows, these are aliases of ‘stricmp()’ and ‘strnicmp()’,
     respectively.

     On other platforms, they are aliases of *note PyOS_mystricmp():
     1d23. and *note PyOS_mystrnicmp(): 1d22, respectively.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/snprintf(3)

   (2) https://manpages.debian.org/vsnprintf(3)

   (3) https://manpages.debian.org/strtoul(3)

   (4) https://manpages.debian.org/strtol(3)


File: python.info,  Node: Character classification and conversion,  Next: PyHash API,  Prev: String conversion and formatting,  Up: Utilities<2>

7.7.8 Character classification and conversion
---------------------------------------------

The following macros provide locale-independent (unlike the C standard
library ‘ctype.h’) character classification and conversion.  The
argument must be a signed or unsigned char.

 -- C Macro: Py_ISALNUM (c)

     Return true if the character 'c' is an alphanumeric character.

 -- C Macro: Py_ISALPHA (c)

     Return true if the character 'c' is an alphabetic character (‘a-z’
     and ‘A-Z’).

 -- C Macro: Py_ISDIGIT (c)

     Return true if the character 'c' is a decimal digit (‘0-9’).

 -- C Macro: Py_ISLOWER (c)

     Return true if the character 'c' is a lowercase ASCII letter
     (‘a-z’).

 -- C Macro: Py_ISUPPER (c)

     Return true if the character 'c' is an uppercase ASCII letter
     (‘A-Z’).

 -- C Macro: Py_ISSPACE (c)

     Return true if the character 'c' is a whitespace character (space,
     tab, carriage return, newline, vertical tab, or form feed).

 -- C Macro: Py_ISXDIGIT (c)

     Return true if the character 'c' is a hexadecimal digit (‘0-9’,
     ‘a-f’, and ‘A-F’).

 -- C Macro: Py_TOLOWER (c)

     Return the lowercase equivalent of the character 'c'.

 -- C Macro: Py_TOUPPER (c)

     Return the uppercase equivalent of the character 'c'.


File: python.info,  Node: PyHash API,  Next: Reflection,  Prev: Character classification and conversion,  Up: Utilities<2>

7.7.9 PyHash API
----------------

See also the *note PyTypeObject.tp_hash: 4edf. member and *note Hashing
dei tipi numerici: 25dd.

 -- C Tipo: type Py_hash_t

     Hash value type: signed integer.

     Added in version 3.2.

 -- C Tipo: type Py_uhash_t

     Hash value type: unsigned integer.

     Added in version 3.2.

 -- C Macro: Py_HASH_ALGORITHM

     A numerical value indicating the algorithm for hashing of *note
     str: 169, *note bytes: 192, and *note memoryview: 165.

     The algorithm name is exposed by *note sys.hash_info.algorithm:
     4905.

     Added in version 3.4.

 -- C Macro: Py_HASH_FNV
 -- C Macro: Py_HASH_SIPHASH24
 -- C Macro: Py_HASH_SIPHASH13

     Numerical values to compare to *note Py_HASH_ALGORITHM: 522d. to
     determine which algorithm is used for hashing.  The hash algorithm
     can be configured via the configure *note -with-hash-algorithm:
     219f. option.

     Added in version 3.4: Add ‘Py_HASH_FNV’ and ‘Py_HASH_SIPHASH24’.

     Added in version 3.11: Add ‘Py_HASH_SIPHASH13’.

 -- C Macro: Py_HASH_CUTOFF

     Buffers of length in range ‘[1, Py_HASH_CUTOFF)’ are hashed using
     DJBX33A instead of the algorithm described by *note
     Py_HASH_ALGORITHM: 522d.

        - A ‘Py_HASH_CUTOFF’ of 0 disables the optimization.

        - ‘Py_HASH_CUTOFF’ must be non-negative and less or equal than
          7.

     32-bit platforms should use a cutoff smaller than 64-bit platforms
     because it is easier to create colliding strings.  A cutoff of 7 on
     64-bit platforms and 5 on 32-bit platforms should provide a decent
     safety margin.

     This corresponds to the *note sys.hash_info.cutoff: 4908. constant.

     Added in version 3.4.

 -- C Macro: PyHASH_MODULUS

     The Mersenne prime(1) ‘P = 2**n -1’, used for numeric hash scheme.

     This corresponds to the *note sys.hash_info.modulus: 25de.
     constant.

     Added in version 3.13.

 -- C Macro: PyHASH_BITS

     The exponent ‘n’ of ‘P’ in *note PyHASH_MODULUS: 19d0.

     Added in version 3.13.

 -- C Macro: PyHASH_MULTIPLIER

     Prime multiplier used in string and various other hashes.

     Added in version 3.13.

 -- C Macro: PyHASH_INF

     The hash value returned for a positive infinity.

     This corresponds to the *note sys.hash_info.inf: 4902. constant.

     Added in version 3.13.

 -- C Macro: PyHASH_IMAG

     The multiplier used for the imaginary part of a complex number.

     This corresponds to the *note sys.hash_info.imag: 4904. constant.

     Added in version 3.13.

 -- C Tipo: type PyHash_FuncDef

     Hash function definition used by *note PyHash_GetFuncDef(): 5233.

      -- C Membro: *note Py_hash_t: 146b. (*const hash)(const void*,
               *note Py_ssize_t: c57.)

          Hash function.

      -- C Membro: const char *name

          Hash function name (UTF-8 encoded string).

          This corresponds to the *note sys.hash_info.algorithm: 4905.
          constant.

      -- C Membro: const int hash_bits

          Internal size of the hash value in bits.

          This corresponds to the *note sys.hash_info.hash_bits: 4906.
          constant.

      -- C Membro: const int seed_bits

          Size of seed input in bits.

          This corresponds to the *note sys.hash_info.seed_bits: 4907.
          constant.

     Added in version 3.4.

 -- C Funzione: *note PyHash_FuncDef: 5232. *PyHash_GetFuncDef (void)

     Get the hash function definition.

     Vedi anche
     ..........

     PEP 456(2) «Secure and interchangeable hash algorithm».

     Added in version 3.4.

 -- C Funzione: *note Py_hash_t: 146b. Py_HashPointer (const void *ptr)

     Hash a pointer value: process the pointer value as an integer (cast
     it to ‘uintptr_t’ internally).  The pointer is not dereferenced.

     The function cannot fail: it cannot return ‘-1’.

     Added in version 3.13.

 -- C Funzione: *note Py_hash_t: 146b. Py_HashBuffer (const void *ptr,
          Py_ssize_t len)

     Compute and return the hash value of a buffer of 'len' bytes
     starting at address 'ptr'.  The hash is guaranteed to match that of
     *note bytes: 192, *note memoryview: 165, and other built-in objects
     that implement the *note buffer protocol: 260.

     Use this function to implement hashing for immutable objects whose
     *note tp_richcompare: 4ed9. function compares to another object’s
     buffer.

     'len' must be greater than or equal to ‘0’.

     This function always succeeds.

     Added in version 3.14.

 -- C Funzione: *note Py_hash_t: 146b. PyObject_GenericHash (PyObject
          *obj)

     Generic hashing function that is meant to be put into a type
     object’s ‘tp_hash’ slot.  Its result only depends on the object’s
     identity.

     'Dettaglio dell’implementazione di CPython:' In CPython, it is
     equivalent to *note Py_HashPointer(): 425.

     Added in version 3.13.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Mersenne_prime

   (2) https://peps.python.org/pep-0456/


File: python.info,  Node: Reflection,  Next: Codec registry and support functions,  Prev: PyHash API,  Up: Utilities<2>

7.7.10 Reflection
-----------------

 -- C Funzione: *note PyObject: 5df. *PyEval_GetBuiltins (void)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'

     Deprecato dalla versione 3.13: Use *note PyEval_GetFrameBuiltins():
     5f3. instead.

     Return a dictionary of the builtins in the current execution frame,
     or the interpreter of the thread state if no frame is currently
     executing.

 -- C Funzione: *note PyObject: 5df. *PyEval_GetLocals (void)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'

     Deprecato dalla versione 3.13: Use either *note
     PyEval_GetFrameLocals(): 5f7. to obtain the same behaviour as
     calling *note locals(): 46f. in Python code, or else call *note
     PyFrame_GetLocals(): 661. on the result of *note PyEval_GetFrame():
     1b21. to access the *note f_locals: 4a6. attribute of the currently
     executing frame.

     Return a mapping providing access to the local variables in the
     current execution frame, or ‘NULL’ if no frame is currently
     executing.

     Refer to *note locals(): 46f. for details of the mapping returned
     at different scopes.

     As this function returns a *note borrowed reference: 3d7, the
     dictionary returned for *note optimized scopes: 4a2. is cached on
     the frame object and will remain alive as long as the frame object
     does.  Unlike *note PyEval_GetFrameLocals(): 5f7. and *note
     locals(): 46f, subsequent calls to this function in the same frame
     will update the contents of the cached dictionary to reflect
     changes in the state of the local variables rather than returning a
     new snapshot.

     Cambiato nella versione 3.13: As part of PEP 667(1), *note
     PyFrame_GetLocals(): 661, *note locals(): 46f, and *note
     FrameType.f_locals: 4a6. no longer make use of the shared cache
     dictionary.  Refer to the *note What’s New entry: 470. for
     additional details.

 -- C Funzione: *note PyObject: 5df. *PyEval_GetGlobals (void)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'

     Deprecato dalla versione 3.13: Use *note PyEval_GetFrameGlobals():
     5f5. instead.

     Return a dictionary of the global variables in the current
     execution frame, or ‘NULL’ if no frame is currently executing.

 -- C Funzione: *note PyFrameObject: 98d. *PyEval_GetFrame (void)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Return the *note attached thread state:
     4eba.’s frame, which is ‘NULL’ if no frame is currently executing.

     See also *note PyThreadState_GetFrame(): 992.

 -- C Funzione: *note PyObject: 5df. *PyEval_GetFrameBuiltins (void)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.13.'  Return a dictionary of the
     builtins in the current execution frame, or the interpreter of the
     thread state if no frame is currently executing.

     Added in version 3.13.

 -- C Funzione: *note PyObject: 5df. *PyEval_GetFrameLocals (void)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.13.'  Return a dictionary of the
     local variables in the current execution frame, or ‘NULL’ if no
     frame is currently executing.  Equivalent to calling *note
     locals(): 46f. in Python code.

     To access *note f_locals: 4a6. on the current frame without making
     an independent snapshot in *note optimized scopes: 4a2, call *note
     PyFrame_GetLocals(): 661. on the result of *note PyEval_GetFrame():
     1b21.

     Added in version 3.13.

 -- C Funzione: *note PyObject: 5df. *PyEval_GetFrameGlobals (void)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.13.'  Return a dictionary of the
     global variables in the current execution frame, or ‘NULL’ if no
     frame is currently executing.  Equivalent to calling *note
     globals(): 1bf2. in Python code.

     Added in version 3.13.

 -- C Funzione: const char *PyEval_GetFuncName (PyObject *func)
     ' Parte del *note ABI Stabile: 776.'  Return the name of 'func' if
     it is a function, class or instance object, else the name of
     'func's type.

 -- C Funzione: const char *PyEval_GetFuncDesc (PyObject *func)
     ' Parte del *note ABI Stabile: 776.'  Return a description string,
     depending on the type of 'func'.  Return values include «()» for
     functions and methods, « constructor», « instance», and « object».
     Concatenated with the result of *note PyEval_GetFuncName(): 4fb5,
     the result will be a description of 'func'.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0667/


File: python.info,  Node: Codec registry and support functions,  Next: PyTime C API,  Prev: Reflection,  Up: Utilities<2>

7.7.11 Codec registry and support functions
-------------------------------------------

 -- C Funzione: int PyCodec_Register (PyObject *search_function)
     ' Parte del *note ABI Stabile: 776.'  Register a new codec search
     function.

     As a side effect, this tries to load the ‘encodings’ package, if
     not yet done, to make sure that it is always first in the list of
     search functions.

 -- C Funzione: int PyCodec_Unregister (PyObject *search_function)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'
     Unregister a codec search function and clear the registry’s cache.
     If the search function is not registered, do nothing.  Return 0 on
     success.  Raise an exception and return -1 on error.

     Added in version 3.10.

 -- C Funzione: int PyCodec_KnownEncoding (const char *encoding)
     ' Parte del *note ABI Stabile: 776.'  Return ‘1’ or ‘0’ depending
     on whether there is a registered codec for the given 'encoding'.
     This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyCodec_Encode (PyObject *object,
          const char *encoding, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Generic codec based encoding API.

     'object' is passed through the encoder function found for the given
     'encoding' using the error handling method defined by 'errors'.
     'errors' may be ‘NULL’ to use the default method defined for the
     codec.  Raises a *note LookupError: 2633. if no encoder can be
     found.

 -- C Funzione: *note PyObject: 5df. *PyCodec_Decode (PyObject *object,
          const char *encoding, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Generic codec based decoding API.

     'object' is passed through the decoder function found for the given
     'encoding' using the error handling method defined by 'errors'.
     'errors' may be ‘NULL’ to use the default method defined for the
     codec.  Raises a *note LookupError: 2633. if no decoder can be
     found.

* Menu:

* Codec lookup API::
* Registry API for Unicode encoding error handlers::
* Codec utility variables::


File: python.info,  Node: Codec lookup API,  Next: Registry API for Unicode encoding error handlers,  Up: Codec registry and support functions

7.7.11.1 Codec lookup API
.........................

In the following functions, the 'encoding' string is looked up converted
to all lower-case characters, which makes encodings looked up through
this mechanism effectively case-insensitive.  If no codec is found, a
*note KeyError: 5e7. is set and ‘NULL’ returned.

 -- C Funzione: *note PyObject: 5df. *PyCodec_Encoder (const char
          *encoding)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Get an encoder function for the given 'encoding'.

 -- C Funzione: *note PyObject: 5df. *PyCodec_Decoder (const char
          *encoding)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Get a decoder function for the given 'encoding'.

 -- C Funzione: *note PyObject: 5df. *PyCodec_IncrementalEncoder (const
          char *encoding, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Get an *note IncrementalEncoder: 281a. object for
     the given 'encoding'.

 -- C Funzione: *note PyObject: 5df. *PyCodec_IncrementalDecoder (const
          char *encoding, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Get an *note IncrementalDecoder: 281b. object for
     the given 'encoding'.

 -- C Funzione: *note PyObject: 5df. *PyCodec_StreamReader (const char
          *encoding, PyObject *stream, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Get a *note StreamReader: 281f. factory function
     for the given 'encoding'.

 -- C Funzione: *note PyObject: 5df. *PyCodec_StreamWriter (const char
          *encoding, PyObject *stream, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Get a *note StreamWriter: 281e. factory function
     for the given 'encoding'.


File: python.info,  Node: Registry API for Unicode encoding error handlers,  Next: Codec utility variables,  Prev: Codec lookup API,  Up: Codec registry and support functions

7.7.11.2 Registry API for Unicode encoding error handlers
.........................................................

 -- C Funzione: int PyCodec_RegisterError (const char *name, PyObject
          *error)
     ' Parte del *note ABI Stabile: 776.'  Register the error handling
     callback function 'error' under the given 'name'.  This callback
     function will be called by a codec when it encounters unencodable
     characters/undecodable bytes and 'name' is specified as the error
     parameter in the call to the encode/decode function.

     The callback gets a single argument, an instance of *note
     UnicodeEncodeError: 888, *note UnicodeDecodeError: c0a. or *note
     UnicodeTranslateError: 18e5. that holds information about the
     problematic sequence of characters or bytes and their offset in the
     original string (see *note Unicode Exception Objects: 461. for
     functions to extract this information).  The callback must either
     raise the given exception, or return a two-item tuple containing
     the replacement for the problematic sequence, and an integer giving
     the offset in the original string at which encoding/decoding should
     be resumed.

     Return ‘0’ on success, ‘-1’ on error.

 -- C Funzione: *note PyObject: 5df. *PyCodec_LookupError (const char
          *name)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Lookup the error handling callback function
     registered under 'name'.  As a special case ‘NULL’ can be passed,
     in which case the error handling callback for «strict» will be
     returned.

 -- C Funzione: *note PyObject: 5df. *PyCodec_StrictErrors (PyObject
          *exc)
     'Valore di ritorno: Sempre NULL.'' Parte del *note ABI Stabile:
     776.'  Raise 'exc' as an exception.

 -- C Funzione: *note PyObject: 5df. *PyCodec_IgnoreErrors (PyObject
          *exc)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Ignore the unicode error, skipping the faulty
     input.

 -- C Funzione: *note PyObject: 5df. *PyCodec_ReplaceErrors (PyObject
          *exc)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Replace the unicode encode error with ‘?’ or
     ‘U+FFFD’.

 -- C Funzione: *note PyObject: 5df. *PyCodec_XMLCharRefReplaceErrors
          (PyObject *exc)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Replace the unicode encode error with XML character
     references.

 -- C Funzione: *note PyObject: 5df. *PyCodec_BackslashReplaceErrors
          (PyObject *exc)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Replace the unicode encode error with backslash
     escapes (‘\x’, ‘\u’ and ‘\U’).

 -- C Funzione: *note PyObject: 5df. *PyCodec_NameReplaceErrors
          (PyObject *exc)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'  Replace the unicode encode
     error with ‘\N{...}’ escapes.

     Added in version 3.5.


File: python.info,  Node: Codec utility variables,  Prev: Registry API for Unicode encoding error handlers,  Up: Codec registry and support functions

7.7.11.3 Codec utility variables
................................

 -- C Variabile: const char *Py_hexdigits

     A string constant containing the lowercase hexadecimal digits:
     ‘"0123456789abcdef"’.

     Added in version 3.3.


File: python.info,  Node: PyTime C API,  Next: Support for Perf Maps,  Prev: Codec registry and support functions,  Up: Utilities<2>

7.7.12 PyTime C API
-------------------

Added in version 3.13.

The clock C API provides access to system clocks.  It is similar to the
Python *note time: f4. module.

For C API related to the *note datetime: 34. module, see *note DateTime
Objects: 5245.

* Menu:

* Types: Types<3>.
* Clock Functions::
* Raw Clock Functions::
* Conversion functions::


File: python.info,  Node: Types<3>,  Next: Clock Functions,  Up: PyTime C API

7.7.12.1 Types
..............

 -- C Tipo: type PyTime_t

     A timestamp or duration in nanoseconds, represented as a signed
     64-bit integer.

     The reference point for timestamps depends on the clock used.  For
     example, *note PyTime_Time(): 5db. returns timestamps relative to
     the UNIX epoch.

     The supported range is around [-292.3 years; +292.3 years].  Using
     the Unix epoch (January 1st, 1970) as reference, the supported date
     range is around [1677-09-21; 2262-04-11].  The exact limits are
     exposed as constants:

 -- C Variabile: *note PyTime_t: 5d3. PyTime_MIN

     Minimum value of *note PyTime_t: 5d3.

 -- C Variabile: *note PyTime_t: 5d3. PyTime_MAX

     Maximum value of *note PyTime_t: 5d3.


File: python.info,  Node: Clock Functions,  Next: Raw Clock Functions,  Prev: Types<3>,  Up: PyTime C API

7.7.12.2 Clock Functions
........................

The following functions take a pointer to a *note PyTime_t: 5d3. that
they set to the value of a particular clock.  Details of each clock are
given in the documentation of the corresponding Python function.

The functions return ‘0’ on success, or ‘-1’ (with an exception set) on
failure.

On integer overflow, they set the *note PyExc_OverflowError: 4fde.
exception and set ‘*result’ to the value clamped to the ‘[PyTime_MIN;
PyTime_MAX]’ range.  (On current systems, integer overflows are likely
caused by misconfigured system time.)

As any other C API (unless otherwise specified), the functions must be
called with an *note attached thread state: 4eba.

 -- C Funzione: int PyTime_Monotonic (PyTime_t *result)

     Read the monotonic clock.  See *note time.monotonic(): 55c. for
     important details on this clock.

 -- C Funzione: int PyTime_PerfCounter (PyTime_t *result)

     Read the performance counter.  See *note time.perf_counter(): c7c.
     for important details on this clock.

 -- C Funzione: int PyTime_Time (PyTime_t *result)

     Read the “wall clock” time.  See *note time.time(): 55d. for
     details important on this clock.


File: python.info,  Node: Raw Clock Functions,  Next: Conversion functions,  Prev: Clock Functions,  Up: PyTime C API

7.7.12.3 Raw Clock Functions
............................

Similar to clock functions, but don’t set an exception on error and
don’t require the caller to have an *note attached thread state: 4eba.

On success, the functions return ‘0’.

On failure, they set ‘*result’ to ‘0’ and return ‘-1’, 'without' setting
an exception.  To get the cause of the error, *note attach: 4eba. a
*note thread state: 182e, and call the regular (non-‘Raw’) function.
Note that the regular function may succeed after the ‘Raw’ one failed.

 -- C Funzione: int PyTime_MonotonicRaw (PyTime_t *result)

     Similar to *note PyTime_Monotonic(): 5d7, but don’t set an
     exception on error and don’t require an *note attached thread
     state: 4eba.

 -- C Funzione: int PyTime_PerfCounterRaw (PyTime_t *result)

     Similar to *note PyTime_PerfCounter(): 5d9, but don’t set an
     exception on error and don’t require an *note attached thread
     state: 4eba.

 -- C Funzione: int PyTime_TimeRaw (PyTime_t *result)

     Similar to *note PyTime_Time(): 5db, but don’t set an exception on
     error and don’t require an *note attached thread state: 4eba.


File: python.info,  Node: Conversion functions,  Prev: Raw Clock Functions,  Up: PyTime C API

7.7.12.4 Conversion functions
.............................

 -- C Funzione: double PyTime_AsSecondsDouble (PyTime_t t)

     Convert a timestamp to a number of seconds as a C double.

     The function cannot fail, but note that double has limited accuracy
     for large values.


File: python.info,  Node: Support for Perf Maps,  Prev: PyTime C API,  Up: Utilities<2>

7.7.13 Support for Perf Maps
----------------------------

On supported platforms (as of this writing, only Linux), the runtime can
take advantage of 'perf map files' to make Python functions visible to
an external profiling tool (such as perf(1)).  A running process may
create a file in the ‘/tmp’ directory, which contains entries that can
map a section of executable code to a name.  This interface is described
in the documentation of the Linux Perf tool(2).

In Python, these helper APIs can be used by libraries and features that
rely on generating machine code on the fly.

Note that holding an *note attached thread state: 4eba. is not required
for these APIs.

 -- C Funzione: int PyUnstable_PerfMapState_Init (void)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Open the ‘/tmp/perf-$pid.map’ file, unless it’s already opened, and
     create a lock to ensure thread-safe writes to the file (provided
     the writes are done through *note PyUnstable_WritePerfMapEntry():
     1a91.).  Normally, there’s no need to call this explicitly; just
     use *note PyUnstable_WritePerfMapEntry(): 1a91. and it will
     initialize the state on first call.

     Returns ‘0’ on success, ‘-1’ on failure to create/open the perf map
     file, or ‘-2’ on failure to create a lock.  Check ‘errno’ for more
     information about the cause of a failure.

 -- C Funzione: int PyUnstable_WritePerfMapEntry (const void *code_addr,
          unsigned int code_size, const char *entry_name)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Write one single entry to the ‘/tmp/perf-$pid.map’ file.  This
     function is thread safe.  Here is what an example entry looks like:

          # address      size  name
          7f3529fcf759 b     py::bar:/run/t.py

     Will call *note PyUnstable_PerfMapState_Init(): 1a92. before
     writing the entry, if the perf map file is not already opened.
     Returns ‘0’ on success, or the same error codes as *note
     PyUnstable_PerfMapState_Init(): 1a92. on failure.

 -- C Funzione: void PyUnstable_PerfMapState_Fini (void)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Close the perf map file opened by *note
     PyUnstable_PerfMapState_Init(): 1a92.  This is called by the
     runtime itself during interpreter shut-down.  In general, there
     shouldn’t be a reason to explicitly call this, except to handle
     specific scenarios such as forking.

   ---------- Footnotes ----------

   (1) https://perf.wiki.kernel.org/index.php/Main_Page

   (2) 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf/Documentation/jit-interface.txt


File: python.info,  Node: Abstract Objects Layer,  Next: Concrete Objects Layer,  Prev: Utilities<2>,  Up: Python/C API Reference Manual

7.8 Abstract Objects Layer
==========================

The functions in this chapter interact with Python objects regardless of
their type, or with wide classes of object types (e.g.  all numerical
types, or all sequence types).  When used on object types for which they
do not apply, they will raise a Python exception.

It is not possible to use these functions on objects that are not
properly initialized, such as a list object that has been created by
*note PyList_New(): 4f21, but whose items have not been set to some
non-‘NULL’ value yet.

* Menu:

* Object Protocol::
* Call Protocol::
* Number Protocol::
* Sequence Protocol::
* Mapping Protocol::
* Iterator Protocol::
* Buffer Protocol::


File: python.info,  Node: Object Protocol,  Next: Call Protocol,  Up: Abstract Objects Layer

7.8.1 Object Protocol
---------------------

 -- C Funzione: *note PyObject: 5df. *Py_GetConstant (unsigned int
          constant_id)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Get a
     *note strong reference: 5e2. to a constant.

     Set an exception and return ‘NULL’ if 'constant_id' is invalid.

     'constant_id' must be one of these constant identifiers:

     Constant Identifier                          Value     Returned object
                                                            
     -------------------------------------------------------------------------------------
                                                            
      -- C Macro: Py_CONSTANT_NONE                ‘0’       *note None: 886.
                                                            
                                                            
      -- C Macro: Py_CONSTANT_FALSE               ‘1’       *note False: d2d.
                                                            
                                                            
      -- C Macro: Py_CONSTANT_TRUE                ‘2’       *note True: e09.
                                                            
                                                            
      -- C Macro: Py_CONSTANT_ELLIPSIS            ‘3’       *note Ellipsis: 2311.
                                                            
                                                            
      -- C Macro: Py_CONSTANT_NOT_IMPLEMENTED     ‘4’       *note NotImplemented: 1a2.
                                                            
                                                            
      -- C Macro: Py_CONSTANT_ZERO                ‘5’       ‘0’
                                                            
                                                            
      -- C Macro: Py_CONSTANT_ONE                 ‘6’       ‘1’
                                                            
                                                            
      -- C Macro: Py_CONSTANT_EMPTY_STR           ‘7’       ‘''’
                                                            
                                                            
      -- C Macro: Py_CONSTANT_EMPTY_BYTES         ‘8’       ‘b''’
                                                            
                                                            
      -- C Macro: Py_CONSTANT_EMPTY_TUPLE         ‘9’       ‘()’
                                                            

     Numeric values are only given for projects which cannot use the
     constant identifiers.

     Added in version 3.13.

     'Dettaglio dell’implementazione di CPython:' In CPython, all of
     these constants are *note immortal: 290.

 -- C Funzione: *note PyObject: 5df. *Py_GetConstantBorrowed (unsigned
          int constant_id)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Similar
     to *note Py_GetConstant(): 5f9, but return a *note borrowed
     reference: 3d7.

     This function is primarily intended for backwards compatibility:
     using *note Py_GetConstant(): 5f9. is recommended for new code.

     The reference is borrowed from the interpreter, and is valid until
     the interpreter finalization.

     Added in version 3.13.

 -- C Variabile: *note PyObject: 5df. *Py_NotImplemented

     The ‘NotImplemented’ singleton, used to signal that an operation is
     not implemented for the given type combination.

 -- C Macro: Py_RETURN_NOTIMPLEMENTED

     Properly handle returning *note Py_NotImplemented: 525e. from
     within a C function (that is, create a new *note strong reference:
     5e2. to *note NotImplemented: 1a2. and return it).

 -- C Macro: Py_PRINT_RAW

     Flag to be used with multiple functions that print the object (like
     *note PyObject_Print(): 1973. and *note PyFile_WriteObject():
     4ffe.).  If passed, these functions use the *note str(): 169. of
     the object instead of the *note repr(): 1c1.

 -- C Funzione: int PyObject_Print (PyObject *o, FILE *fp, int flags)

     Print an object 'o', on file 'fp'.  Returns ‘-1’ on error.  The
     flags argument is used to enable certain printing options.  The
     only option currently supported is *note Py_PRINT_RAW: 525f.; if
     given, the *note str(): 169. of the object is written instead of
     the *note repr(): 1c1.

 -- C Funzione: int PyObject_HasAttrWithError (PyObject *o, PyObject
          *attr_name)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Returns
     ‘1’ if 'o' has the attribute 'attr_name', and ‘0’ otherwise.  This
     is equivalent to the Python expression ‘hasattr(o, attr_name)’.  On
     failure, return ‘-1’.

     Added in version 3.13.

 -- C Funzione: int PyObject_HasAttrStringWithError (PyObject *o, const
          char *attr_name)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  This is
     the same as *note PyObject_HasAttrWithError(): 61b, but 'attr_name'
     is specified as a const char* UTF-8 encoded bytes string, rather
     than a *note PyObject: 5df.*.

     Added in version 3.13.

 -- C Funzione: int PyObject_HasAttr (PyObject *o, PyObject *attr_name)
     ' Parte del *note ABI Stabile: 776.'  Returns ‘1’ if 'o' has the
     attribute 'attr_name', and ‘0’ otherwise.  This function always
     succeeds.

          Nota: Exceptions that occur when this calls *note
          __getattr__(): 6fb. and *note __getattribute__(): dcd. methods
          aren’t propagated, but instead given to *note
          sys.unraisablehook(): 508.  For proper error handling, use
          *note PyObject_HasAttrWithError(): 61b, *note
          PyObject_GetOptionalAttr(): 5ec. or *note PyObject_GetAttr():
          5ee. instead.

 -- C Funzione: int PyObject_HasAttrString (PyObject *o, const char
          *attr_name)
     ' Parte del *note ABI Stabile: 776.'  This is the same as *note
     PyObject_HasAttr(): 61c, but 'attr_name' is specified as a const
     char* UTF-8 encoded bytes string, rather than a *note PyObject:
     5df.*.

          Nota: Exceptions that occur when this calls *note
          __getattr__(): 6fb. and *note __getattribute__(): dcd. methods
          or while creating the temporary *note str: 169. object are
          silently ignored.  For proper error handling, use *note
          PyObject_HasAttrStringWithError(): 61d, *note
          PyObject_GetOptionalAttrString(): 5ed. or *note
          PyObject_GetAttrString(): 5ef. instead.

 -- C Funzione: *note PyObject: 5df. *PyObject_GetAttr (PyObject *o,
          PyObject *attr_name)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Retrieve an attribute named 'attr_name' from object
     'o'.  Returns the attribute value on success, or ‘NULL’ on failure.
     This is the equivalent of the Python expression ‘o.attr_name’.

     If the missing attribute should not be treated as a failure, you
     can use *note PyObject_GetOptionalAttr(): 5ec. instead.

 -- C Funzione: *note PyObject: 5df. *PyObject_GetAttrString (PyObject
          *o, const char *attr_name)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This is the same as *note PyObject_GetAttr(): 5ee,
     but 'attr_name' is specified as a const char* UTF-8 encoded bytes
     string, rather than a *note PyObject: 5df.*.

     If the missing attribute should not be treated as a failure, you
     can use *note PyObject_GetOptionalAttrString(): 5ed. instead.

 -- C Funzione: int PyObject_GetOptionalAttr (PyObject *obj, PyObject
          *attr_name, PyObject **result);
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Variant
     of *note PyObject_GetAttr(): 5ee. which doesn’t raise *note
     AttributeError: 5f0. if the attribute is not found.

     If the attribute is found, return ‘1’ and set '*result' to a new
     *note strong reference: 5e2. to the attribute.  If the attribute is
     not found, return ‘0’ and set '*result' to ‘NULL’; the *note
     AttributeError: 5f0. is silenced.  If an error other than *note
     AttributeError: 5f0. is raised, return ‘-1’ and set '*result' to
     ‘NULL’.

     Added in version 3.13.

 -- C Funzione: int PyObject_GetOptionalAttrString (PyObject *obj, const
          char *attr_name, PyObject **result);
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  This is
     the same as *note PyObject_GetOptionalAttr(): 5ec, but 'attr_name'
     is specified as a const char* UTF-8 encoded bytes string, rather
     than a *note PyObject: 5df.*.

     Added in version 3.13.

 -- C Funzione: *note PyObject: 5df. *PyObject_GenericGetAttr (PyObject
          *o, PyObject *name)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Generic attribute getter function that is meant to
     be put into a type object’s ‘tp_getattro’ slot.  It looks for a
     descriptor in the dictionary of classes in the object’s MRO as well
     as an attribute in the object’s *note __dict__: 77e. (if present).
     As outlined in *note Implementing Descriptors: e4b, data
     descriptors take preference over instance attributes, while
     non-data descriptors don’t.  Otherwise, an *note AttributeError:
     5f0. is raised.

 -- C Funzione: int PyObject_SetAttr (PyObject *o, PyObject *attr_name,
          PyObject *v)
     ' Parte del *note ABI Stabile: 776.'  Set the value of the
     attribute named 'attr_name', for object 'o', to the value 'v'.
     Raise an exception and return ‘-1’ on failure; return ‘0’ on
     success.  This is the equivalent of the Python statement
     ‘o.attr_name = v’.

     If 'v' is ‘NULL’, the attribute is deleted.  This behaviour is
     deprecated in favour of using *note PyObject_DelAttr(): 1819, but
     there are currently no plans to remove it.

 -- C Funzione: int PyObject_SetAttrString (PyObject *o, const char
          *attr_name, PyObject *v)
     ' Parte del *note ABI Stabile: 776.'  This is the same as *note
     PyObject_SetAttr(): 506f, but 'attr_name' is specified as a const
     char* UTF-8 encoded bytes string, rather than a *note PyObject:
     5df.*.

     If 'v' is ‘NULL’, the attribute is deleted, but this feature is
     deprecated in favour of using *note PyObject_DelAttrString(): 181a.

     The number of different attribute names passed to this function
     should be kept small, usually by using a statically allocated
     string as 'attr_name'.  For attribute names that aren’t known at
     compile time, prefer calling *note PyUnicode_FromString(): 50ea.
     and *note PyObject_SetAttr(): 506f. directly.  For more details,
     see *note PyUnicode_InternFromString(): 1974, which may be used
     internally to create a key object.

 -- C Funzione: int PyObject_GenericSetAttr (PyObject *o, PyObject
          *name, PyObject *value)
     ' Parte del *note ABI Stabile: 776.'  Generic attribute setter and
     deleter function that is meant to be put into a type object’s *note
     tp_setattro: 4ed1. slot.  It looks for a data descriptor in the
     dictionary of classes in the object’s MRO, and if found it takes
     preference over setting or deleting the attribute in the instance
     dictionary.  Otherwise, the attribute is set or deleted in the
     object’s *note __dict__: 77e. (if present).  On success, ‘0’ is
     returned, otherwise an *note AttributeError: 5f0. is raised and
     ‘-1’ is returned.

 -- C Funzione: int PyObject_DelAttr (PyObject *o, PyObject *attr_name)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Delete
     attribute named 'attr_name', for object 'o'.  Returns ‘-1’ on
     failure.  This is the equivalent of the Python statement ‘del
     o.attr_name’.

 -- C Funzione: int PyObject_DelAttrString (PyObject *o, const char
          *attr_name)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  This is
     the same as *note PyObject_DelAttr(): 1819, but 'attr_name' is
     specified as a const char* UTF-8 encoded bytes string, rather than
     a *note PyObject: 5df.*.

     The number of different attribute names passed to this function
     should be kept small, usually by using a statically allocated
     string as 'attr_name'.  For attribute names that aren’t known at
     compile time, prefer calling *note PyUnicode_FromString(): 50ea.
     and *note PyObject_DelAttr(): 1819. directly.  For more details,
     see *note PyUnicode_InternFromString(): 1974, which may be used
     internally to create a key object for lookup.

 -- C Funzione: *note PyObject: 5df. *PyObject_GenericGetDict (PyObject
          *o, void *context)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.10.'  A generic implementation for
     the getter of a ‘__dict__’ descriptor.  It creates the dictionary
     if necessary.

     This function may also be called to get the *note __dict__: 77e. of
     the object 'o'.  Pass ‘NULL’ for 'context' when calling it.  Since
     this function may need to allocate memory for the dictionary, it
     may be more efficient to call *note PyObject_GetAttr(): 5ee. when
     accessing an attribute on the object.

     On failure, returns ‘NULL’ with an exception set.

     Added in version 3.3.

 -- C Funzione: int PyObject_GenericSetDict (PyObject *o, PyObject
          *value, void *context)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  A generic
     implementation for the setter of a ‘__dict__’ descriptor.  This
     implementation does not allow the dictionary to be deleted.

     Added in version 3.3.

 -- C Funzione: *note PyObject: 5df. **_PyObject_GetDictPtr (PyObject
          *obj)

     Return a pointer to *note __dict__: 77e. of the object 'obj'.  If
     there is no ‘__dict__’, return ‘NULL’ without setting an exception.

     This function may need to allocate memory for the dictionary, so it
     may be more efficient to call *note PyObject_GetAttr(): 5ee. when
     accessing an attribute on the object.

 -- C Funzione: *note PyObject: 5df. *PyObject_RichCompare (PyObject
          *o1, PyObject *o2, int opid)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Compare the values of 'o1' and 'o2' using the
     operation specified by 'opid', which must be one of *note Py_LT:
     5261, *note Py_LE: 5262, *note Py_EQ: 5263, *note Py_NE: 5264,
     *note Py_GT: 5265, or *note Py_GE: 5266, corresponding to ‘<’,
     ‘<=’, ‘==’, ‘!=’, ‘>’, or ‘>=’ respectively.  This is the
     equivalent of the Python expression ‘o1 op o2’, where ‘op’ is the
     operator corresponding to 'opid'.  Returns the value of the
     comparison on success, or ‘NULL’ on failure.

 -- C Funzione: int PyObject_RichCompareBool (PyObject *o1, PyObject
          *o2, int opid)
     ' Parte del *note ABI Stabile: 776.'  Compare the values of 'o1'
     and 'o2' using the operation specified by 'opid', like *note
     PyObject_RichCompare(): 4eda, but returns ‘-1’ on error, ‘0’ if the
     result is false, ‘1’ otherwise.

     Nota: If 'o1' and 'o2' are the same object, *note
     PyObject_RichCompareBool(): 1d74. will always return ‘1’ for *note
     Py_EQ: 5263. and ‘0’ for *note Py_NE: 5264.

 -- C Funzione: *note PyObject: 5df. *PyObject_Format (PyObject *obj,
          PyObject *format_spec)
     ' Parte del *note ABI Stabile: 776.'  Format 'obj' using
     'format_spec'.  This is equivalent to the Python expression
     ‘format(obj, format_spec)’.

     'format_spec' may be ‘NULL’.  In this case the call is equivalent
     to ‘format(obj)’.  Returns the formatted string on success, ‘NULL’
     on failure.

 -- C Funzione: *note PyObject: 5df. *PyObject_Repr (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     Compute a string representation of object 'o'.  Returns the string
     representation on success, ‘NULL’ on failure.  This is the
     equivalent of the Python expression ‘repr(o)’.  Called by the *note
     repr(): 1c1. built-in function.

     Cambiato nella versione 3.4: This function now includes a debug
     assertion to help ensure that it does not silently discard an
     active exception.

 -- C Funzione: *note PyObject: 5df. *PyObject_ASCII (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     As *note PyObject_Repr(): 1231, compute a string representation of
     object 'o', but escape the non-ASCII characters in the string
     returned by *note PyObject_Repr(): 1231. with ‘\x’, ‘\u’ or ‘\U’
     escapes.  This generates a string similar to that returned by *note
     PyObject_Repr(): 1231. in Python 2.  Called by the *note ascii():
     15ed. built-in function.

 -- C Funzione: *note PyObject: 5df. *PyObject_Str (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Compute a string representation of object 'o'.
     Returns the string representation on success, ‘NULL’ on failure.
     This is the equivalent of the Python expression ‘str(o)’.  Called
     by the *note str(): 169. built-in function and, therefore, by the
     *note print(): 1177. function.

     Cambiato nella versione 3.4: This function now includes a debug
     assertion to help ensure that it does not silently discard an
     active exception.

 -- C Funzione: *note PyObject: 5df. *PyObject_Bytes (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     Compute a bytes representation of object 'o'.  ‘NULL’ is returned
     on failure and a bytes object on success.  This is equivalent to
     the Python expression ‘bytes(o)’, when 'o' is not an integer.
     Unlike ‘bytes(o)’, a TypeError is raised when 'o' is an integer
     instead of a zero-initialized bytes object.

 -- C Funzione: int PyObject_IsSubclass (PyObject *derived, PyObject
          *cls)
     ' Parte del *note ABI Stabile: 776.'  Return ‘1’ if the class
     'derived' is identical to or derived from the class 'cls',
     otherwise return ‘0’.  In case of an error, return ‘-1’.

     If 'cls' is a tuple, the check will be done against every entry in
     'cls'.  The result will be ‘1’ when at least one of the checks
     returns ‘1’, otherwise it will be ‘0’.

     If 'cls' has a *note __subclasscheck__(): 23ad. method, it will be
     called to determine the subclass status as described in PEP
     3119(1).  Otherwise, 'derived' is a subclass of 'cls' if it is a
     direct or indirect subclass, i.e.  contained in *note cls.__mro__:
     235e.

     Normally only class objects, i.e.  instances of *note type: f46. or
     a derived class, are considered classes.  However, objects can
     override this by having a *note __bases__: 16b3. attribute (which
     must be a tuple of base classes).

 -- C Funzione: int PyObject_IsInstance (PyObject *inst, PyObject *cls)
     ' Parte del *note ABI Stabile: 776.'  Return ‘1’ if 'inst' is an
     instance of the class 'cls' or a subclass of 'cls', or ‘0’ if not.
     On error, returns ‘-1’ and sets an exception.

     If 'cls' is a tuple, the check will be done against every entry in
     'cls'.  The result will be ‘1’ when at least one of the checks
     returns ‘1’, otherwise it will be ‘0’.

     If 'cls' has a *note __instancecheck__(): 23ac. method, it will be
     called to determine the subclass status as described in PEP
     3119(2).  Otherwise, 'inst' is an instance of 'cls' if its class is
     a subclass of 'cls'.

     An instance 'inst' can override what is considered its class by
     having a *note __class__: 16b4. attribute.

     An object 'cls' can override if it is considered a class, and what
     its base classes are, by having a *note __bases__: 16b3. attribute
     (which must be a tuple of base classes).

 -- C Funzione: *note Py_hash_t: 146b. PyObject_Hash (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'

     Compute and return the hash value of an object 'o'.  On failure,
     return ‘-1’.  This is the equivalent of the Python expression
     ‘hash(o)’.

     Cambiato nella versione 3.2: The return type is now Py_hash_t.
     This is a signed integer the same size as *note Py_ssize_t: c57.

 -- C Funzione: *note Py_hash_t: 146b. PyObject_HashNotImplemented
          (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Set a *note TypeError: 198.
     indicating that ‘type(o)’ is not *note hashable: 825. and return
     ‘-1’.  This function receives special treatment when stored in a
     ‘tp_hash’ slot, allowing a type to explicitly indicate to the
     interpreter that it is not hashable.

 -- C Funzione: int PyObject_IsTrue (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Returns ‘1’ if the object 'o'
     is considered to be true, and ‘0’ otherwise.  This is equivalent to
     the Python expression ‘not not o’.  On failure, return ‘-1’.

 -- C Funzione: int PyObject_Not (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Returns ‘0’ if the object 'o'
     is considered to be true, and ‘1’ otherwise.  This is equivalent to
     the Python expression ‘not o’.  On failure, return ‘-1’.

 -- C Funzione: *note PyObject: 5df. *PyObject_Type (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     When 'o' is non-‘NULL’, returns a type object corresponding to the
     object type of object 'o'.  On failure, raises *note SystemError:
     796. and returns ‘NULL’.  This is equivalent to the Python
     expression ‘type(o)’.  This function creates a new *note strong
     reference: 5e2. to the return value.  There’s really no reason to
     use this function instead of the *note Py_TYPE(): 3c9. function,
     which returns a pointer of type *note PyTypeObject: c9e.*, except
     when a new *note strong reference: 5e2. is needed.

 -- C Funzione: int PyObject_TypeCheck (PyObject *o, PyTypeObject *type)

     Return non-zero if the object 'o' is of type 'type' or a subtype of
     'type', and ‘0’ otherwise.  Both parameters must be non-‘NULL’.

 -- C Funzione: *note Py_ssize_t: c57. PyObject_Size (PyObject *o)
 -- C Funzione: *note Py_ssize_t: c57. PyObject_Length (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'

     Return the length of object 'o'.  If the object 'o' provides either
     the sequence and mapping protocols, the sequence length is
     returned.  On error, ‘-1’ is returned.  This is the equivalent to
     the Python expression ‘len(o)’.

 -- C Funzione: *note Py_ssize_t: c57. PyObject_LengthHint (PyObject *o,
          Py_ssize_t defaultvalue)

     Return an estimated length for the object 'o'.  First try to return
     its actual length, then an estimate using *note __length_hint__():
     1110, and finally return the default value.  On error return ‘-1’.
     This is the equivalent to the Python expression
     ‘operator.length_hint(o, defaultvalue)’.

     Added in version 3.4.

 -- C Funzione: *note PyObject: 5df. *PyObject_GetItem (PyObject *o,
          PyObject *key)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return element of 'o' corresponding to the object
     'key' or ‘NULL’ on failure.  This is the equivalent of the Python
     expression ‘o[key]’.

 -- C Funzione: int PyObject_SetItem (PyObject *o, PyObject *key,
          PyObject *v)
     ' Parte del *note ABI Stabile: 776.'  Map the object 'key' to the
     value 'v'.  Raise an exception and return ‘-1’ on failure; return
     ‘0’ on success.  This is the equivalent of the Python statement
     ‘o[key] = v’.  This function 'does not' steal a reference to 'v'.

 -- C Funzione: int PyObject_DelItem (PyObject *o, PyObject *key)
     ' Parte del *note ABI Stabile: 776.'  Remove the mapping for the
     object 'key' from the object 'o'.  Return ‘-1’ on failure.  This is
     equivalent to the Python statement ‘del o[key]’.

 -- C Funzione: int PyObject_DelItemString (PyObject *o, const char
          *key)
     ' Parte del *note ABI Stabile: 776.'  This is the same as *note
     PyObject_DelItem(): 5062, but 'key' is specified as a const char*
     UTF-8 encoded bytes string, rather than a *note PyObject: 5df.*.

 -- C Funzione: *note PyObject: 5df. *PyObject_Dir (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This is equivalent to the Python expression
     ‘dir(o)’, returning a (possibly empty) list of strings appropriate
     for the object argument, or ‘NULL’ if there was an error.  If the
     argument is ‘NULL’, this is like the Python ‘dir()’, returning the
     names of the current locals; in this case, if no execution frame is
     active then ‘NULL’ is returned but *note PyErr_Occurred(): 1c97.
     will return false.

 -- C Funzione: *note PyObject: 5df. *PyObject_GetIter (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This is equivalent to the Python expression
     ‘iter(o)’.  It returns a new iterator for the object argument, or
     the object itself if the object is already an iterator.  Raises
     *note TypeError: 198. and returns ‘NULL’ if the object cannot be
     iterated.

 -- C Funzione: *note PyObject: 5df. *PyObject_SelfIter (PyObject *obj)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This is equivalent to the Python ‘__iter__(self):
     return self’ method.  It is intended for *note iterator: 4c9.
     types, to be used in the *note PyTypeObject.tp_iter: 16f6. slot.

 -- C Funzione: *note PyObject: 5df. *PyObject_GetAIter (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.10.'  This is the equivalent to the
     Python expression ‘aiter(o)’.  Takes an ‘AsyncIterable’ object and
     returns an ‘AsyncIterator’ for it.  This is typically a new
     iterator but if the argument is an ‘AsyncIterator’, this returns
     itself.  Raises *note TypeError: 198. and returns ‘NULL’ if the
     object cannot be iterated.

     Added in version 3.10.

 -- C Funzione: void *PyObject_GetTypeData (PyObject *o, PyTypeObject
          *cls)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Get a
     pointer to subclass-specific data reserved for 'cls'.

     The object 'o' must be an instance of 'cls', and 'cls' must have
     been created using negative *note PyType_Spec.basicsize: 76b.
     Python does not check this.

     On error, set an exception and return ‘NULL’.

     Added in version 3.12.

 -- C Funzione: *note Py_ssize_t: c57. PyType_GetTypeDataSize
          (PyTypeObject *cls)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Return
     the size of the instance memory space reserved for 'cls', i.e.  the
     size of the memory *note PyObject_GetTypeData(): 76c. returns.

     This may be larger than requested using *note
     -PyType_Spec.basicsize: 76b.; it is safe to use this larger size
     (e.g.  with ‘memset()’).

     The type 'cls' 'must' have been created using negative *note
     PyType_Spec.basicsize: 76b.  Python does not check this.

     On error, set an exception and return a negative value.

     Added in version 3.12.

 -- C Funzione: void *PyObject_GetItemData (PyObject *o)

     Get a pointer to per-item data for a class with *note
     Py_TPFLAGS_ITEMS_AT_END: 76e.

     On error, set an exception and return ‘NULL’.  *note TypeError:
     198. is raised if 'o' does not have *note Py_TPFLAGS_ITEMS_AT_END:
     76e. set.

     Added in version 3.12.

 -- C Funzione: int PyObject_VisitManagedDict (PyObject *obj, visitproc
          visit, void *arg)

     Visit the managed dictionary of 'obj'.

     This function must only be called in a traverse function of the
     type which has the *note Py_TPFLAGS_MANAGED_DICT: 60f. flag set.

     Added in version 3.13.

 -- C Funzione: void PyObject_ClearManagedDict (PyObject *obj)

     Clear the managed dictionary of 'obj'.

     This function must only be called in a clear function of the type
     which has the *note Py_TPFLAGS_MANAGED_DICT: 60f. flag set.

     Added in version 3.13.

 -- C Funzione: int PyUnstable_Object_EnableDeferredRefcount (PyObject
          *obj)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Enable deferred reference counting(3) on 'obj', if supported by the
     runtime.  In the *note free-threaded: 1f4. build, this allows the
     interpreter to avoid reference count adjustments to 'obj', which
     may improve multi-threaded performance.  The tradeoff is that 'obj'
     will only be deallocated by the tracing garbage collector, and not
     when the interpreter no longer has any references to it.

     This function returns ‘1’ if deferred reference counting is enabled
     on 'obj', and ‘0’ if deferred reference counting is not supported
     or if the hint was ignored by the interpreter, such as when
     deferred reference counting is already enabled on 'obj'.  This
     function is thread-safe, and cannot fail.

     This function does nothing on builds with the *note GIL: 164.
     enabled, which do not support deferred reference counting.  This
     also does nothing if 'obj' is not an object tracked by the garbage
     collector (see *note gc.is_tracked(): 1515. and *note
     PyObject_GC_IsTracked(): b6f.).

     This function is intended to be used soon after 'obj' is created,
     by the code that creates it, such as in the object’s *note tp_new:
     7a0. slot.

     Added in version 3.14.

 -- C Funzione: int PyUnstable_Object_IsUniqueReferencedTemporary
          (PyObject *obj)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Check if 'obj' is a unique temporary object.  Returns ‘1’ if 'obj'
     is known to be a unique temporary object, and ‘0’ otherwise.  This
     function cannot fail, but the check is conservative, and may return
     ‘0’ in some cases even if 'obj' is a unique temporary object.

     If an object is a unique temporary, it is guaranteed that the
     current code has the only reference to the object.  For arguments
     to C functions, this should be used instead of checking if the
     reference count is ‘1’.  Starting with Python 3.14, the interpreter
     internally avoids some reference count modifications when loading
     objects onto the operands stack by *note borrowing: 3d7. references
     when possible, which means that a reference count of ‘1’ by itself
     does not guarantee that a function argument uniquely referenced.

     In the example below, ‘my_func’ is called with a unique temporary
     object as its argument:

          my_func([1, 2, 3])

     In the example below, ‘my_func’ is 'not' called with a unique
     temporary object as its argument, even if its refcount is ‘1’:

          my_list = [1, 2, 3]
          my_func(my_list)

     See also the function *note Py_REFCNT(): 2cf.

     Added in version 3.14.

 -- C Funzione: int PyUnstable_IsImmortal (PyObject *obj)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     This function returns non-zero if 'obj' is *note immortal: 290, and
     zero otherwise.  This function cannot fail.

          Nota: Objects that are immortal in one CPython version are not
          guaranteed to be immortal in another.

     Added in version 3.14.

 -- C Funzione: int PyUnstable_TryIncRef (PyObject *obj)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Increments the reference count of 'obj' if it is not zero.  Returns
     ‘1’ if the object’s reference count was successfully incremented.
     Otherwise, this function returns ‘0’.

     *note PyUnstable_EnableTryIncRef(): 18b2. must have been called
     earlier on 'obj' or this function may spuriously return ‘0’ in the
     *note free threading: 1f4. build.

     This function is logically equivalent to the following C code,
     except that it behaves atomically in the *note free threading: 1f4.
     build:

          if (Py_REFCNT(op) > 0) {
             Py_INCREF(op);
             return 1;
          }
          return 0;

     This is intended as a building block for managing weak references
     without the overhead of a Python *note weak reference object: 5267.

     Typically, correct use of this function requires support from
     'obj'’s deallocator (*note tp_dealloc: 4ea5.).  For example, the
     following sketch could be adapted to implement a «weakmap» that
     works like a *note WeakValueDictionary: 1912. for a specific type:

          PyMutex mutex;

          PyObject *
          add_entry(weakmap_key_type *key, PyObject *value)
          {
              PyUnstable_EnableTryIncRef(value);
              weakmap_type weakmap = ...;
              PyMutex_Lock(&mutex);
              weakmap_add_entry(weakmap, key, value);
              PyMutex_Unlock(&mutex);
              Py_RETURN_NONE;
          }

          PyObject *
          get_value(weakmap_key_type *key)
          {
              weakmap_type weakmap = ...;
              PyMutex_Lock(&mutex);
              PyObject *result = weakmap_find(weakmap, key);
              if (PyUnstable_TryIncRef(result)) {
                  // `result` is safe to use
                  PyMutex_Unlock(&mutex);
                  return result;
              }
              // if we get here, `result` is starting to be garbage-collected,
              // but has not been removed from the weakmap yet
              PyMutex_Unlock(&mutex);
              return NULL;
          }

          // tp_dealloc function for weakmap values
          void
          value_dealloc(PyObject *value)
          {
              weakmap_type weakmap = ...;
              PyMutex_Lock(&mutex);
              weakmap_remove_value(weakmap, value);

              ...
              PyMutex_Unlock(&mutex);
          }

     Added in version 3.14.

 -- C Funzione: void PyUnstable_EnableTryIncRef (PyObject *obj)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Enables subsequent uses of *note PyUnstable_TryIncRef(): 18b1. on
     'obj'.  The caller must hold a *note strong reference: 5e2. to
     'obj' when calling this.

     Added in version 3.14.

 -- C Funzione: int PyUnstable_Object_IsUniquelyReferenced (PyObject
          *op)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Determine if 'op' only has one reference.

     On GIL-enabled builds, this function is equivalent to *note
     Py_REFCNT: 2cf.(*note op: 3c6.) == 1.

     On a *note free threaded: 1f4. build, this checks if 'op'’s *note
     reference count: 4eb2. is equal to one and additionally checks if
     'op' is only used by this thread.  *note Py_REFCNT: 2cf.(*note op:
     3c6.) == 1 is 'not' thread-safe on free threaded builds; prefer
     this function.

     The caller must hold an *note attached thread state: 4eba, despite
     the fact that this function doesn’t call into the Python
     interpreter.  This function cannot fail.

     Added in version 3.14.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3119/

   (2) https://peps.python.org/pep-3119/

   (3) https://peps.python.org/pep-0703/#deferred-reference-counting


File: python.info,  Node: Call Protocol,  Next: Number Protocol,  Prev: Object Protocol,  Up: Abstract Objects Layer

7.8.2 Call Protocol
-------------------

CPython supports two different calling protocols: 'tp_call' and
vectorcall.

* Menu:

* The tp_call Protocol::
* The Vectorcall Protocol::
* Object Calling API::
* Call Support API::


File: python.info,  Node: The tp_call Protocol,  Next: The Vectorcall Protocol,  Up: Call Protocol

7.8.2.1 The 'tp_call' Protocol
..............................

Instances of classes that set *note tp_call: 77c. are callable.  The
signature of the slot is:

     PyObject *tp_call(PyObject *callable, PyObject *args, PyObject *kwargs);

A call is made using a tuple for the positional arguments and a dict for
the keyword arguments, similarly to ‘callable(*args, **kwargs)’ in
Python code.  'args' must be non-NULL (use an empty tuple if there are
no arguments) but 'kwargs' may be 'NULL' if there are no keyword
arguments.

This convention is not only used by 'tp_call': *note tp_new: 7a0. and
*note tp_init: 7a2. also pass arguments this way.

To call an object, use *note PyObject_Call(): 63d. or another *note call
API: 526c.


File: python.info,  Node: The Vectorcall Protocol,  Next: Object Calling API,  Prev: The tp_call Protocol,  Up: Call Protocol

7.8.2.2 The Vectorcall Protocol
...............................

Added in version 3.9.

The vectorcall protocol was introduced in PEP 590(1) as an additional
protocol for making calls more efficient.

As rule of thumb, CPython will prefer the vectorcall for internal calls
if the callable supports it.  However, this is not a hard rule.
Additionally, some third-party extensions use 'tp_call' directly (rather
than using *note PyObject_Call(): 63d.).  Therefore, a class supporting
vectorcall must also implement *note tp_call: 77c.  Moreover, the
callable must behave the same regardless of which protocol is used.  The
recommended way to achieve this is by setting *note tp_call: 77c. to
*note PyVectorcall_Call(): 779.  This bears repeating:

     Avvertimento: A class supporting vectorcall 'must' also implement
     *note tp_call: 77c. with the same semantics.

Cambiato nella versione 3.12: The *note Py_TPFLAGS_HAVE_VECTORCALL: 777.
flag is now removed from a class when the class’s *note __call__(): 77b.
method is reassigned.  (This internally sets *note tp_call: 77c. only,
and thus may make it behave differently than the vectorcall function.)
In earlier Python versions, vectorcall should only be used with *note
immutable: 3cf. or static types.

A class should not implement vectorcall if that would be slower than
'tp_call'.  For example, if the callee needs to convert the arguments to
an args tuple and kwargs dict anyway, then there is no point in
implementing vectorcall.

Classes can implement the vectorcall protocol by enabling the *note
Py_TPFLAGS_HAVE_VECTORCALL: 777. flag and setting *note
tp_vectorcall_offset: 526e. to the offset inside the object structure
where a 'vectorcallfunc' appears.  This is a pointer to a function with
the following signature:

 -- C Tipo: typedef *note PyObject: 5df. *(*vectorcallfunc)(*note
          PyObject: 5df. *callable, *note PyObject: 5df. *const *args,
          size_t nargsf, *note PyObject: 5df. *kwnames)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'

   - 'callable' is the object being called.

   - 
     'args' is a C array consisting of the positional arguments followed by the

          values of the keyword arguments.  This can be 'NULL' if there
          are no arguments.

   - 
     'nargsf' is the number of positional arguments plus possibly the

          *note PY_VECTORCALL_ARGUMENTS_OFFSET: 781. flag.  To get the
          actual number of positional arguments from 'nargsf', use *note
          PyVectorcall_NARGS(): 778.

   - 
     'kwnames' is a tuple containing the names of the keyword arguments;

          in other words, the keys of the kwargs dict.  These names must
          be strings (instances of ‘str’ or a subclass) and they must be
          unique.  If there are no keyword arguments, then 'kwnames' can
          instead be 'NULL'.

 -- C Macro: PY_VECTORCALL_ARGUMENTS_OFFSET
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  If this
     flag is set in a vectorcall 'nargsf' argument, the callee is
     allowed to temporarily change ‘args[-1]’.  In other words, 'args'
     points to argument 1 (not 0) in the allocated vector.  The callee
     must restore the value of ‘args[-1]’ before returning.

     For *note PyObject_VectorcallMethod(): 780, this flag means instead
     that ‘args[0]’ may be changed.

     Whenever they can do so cheaply (without additional allocation),
     callers are encouraged to use *note PY_VECTORCALL_ARGUMENTS_OFFSET:
     781.  Doing so will allow callables such as bound methods to make
     their onward calls (which include a prepended 'self' argument) very
     efficiently.

     Added in version 3.8.

To call an object that implements vectorcall, use a *note call API:
526c. function as with any other callable.  *note PyObject_Vectorcall():
77f. will usually be most efficient.

* Menu:

* Recursion Control: Recursion Control<2>.
* Vectorcall Support API::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0590/


File: python.info,  Node: Recursion Control<2>,  Next: Vectorcall Support API,  Up: The Vectorcall Protocol

7.8.2.3 Recursion Control
.........................

When using 'tp_call', callees do not need to worry about *note
recursion: 51d7.: CPython uses *note Py_EnterRecursiveCall(): 3d2. and
*note Py_LeaveRecursiveCall(): b6d. for calls made using 'tp_call'.

For efficiency, this is not the case for calls done using vectorcall:
the callee should use 'Py_EnterRecursiveCall' and
'Py_LeaveRecursiveCall' if needed.


File: python.info,  Node: Vectorcall Support API,  Prev: Recursion Control<2>,  Up: The Vectorcall Protocol

7.8.2.4 Vectorcall Support API
..............................

 -- C Funzione: *note Py_ssize_t: c57. PyVectorcall_NARGS (size_t
          nargsf)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Given a
     vectorcall 'nargsf' argument, return the actual number of
     arguments.  Currently equivalent to:

          (Py_ssize_t)(nargsf & ~PY_VECTORCALL_ARGUMENTS_OFFSET)

     However, the function ‘PyVectorcall_NARGS’ should be used to allow
     for future extensions.

     Added in version 3.8.

 -- C Funzione: *note vectorcallfunc: 77a. PyVectorcall_Function
          (PyObject *op)

     If 'op' does not support the vectorcall protocol (either because
     the type does not or because the specific instance does not),
     return 'NULL'. Otherwise, return the vectorcall function pointer
     stored in 'op'.  This function never raises an exception.

     This is mostly useful to check whether or not 'op' supports
     vectorcall, which can be done by checking
     ‘PyVectorcall_Function(op) != NULL’.

     Added in version 3.9.

 -- C Funzione: *note PyObject: 5df. *PyVectorcall_Call (PyObject
          *callable, PyObject *tuple, PyObject *dict)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Call
     'callable'’s *note vectorcallfunc: 77a. with positional and keyword
     arguments given in a tuple and dict, respectively.

     This is a specialized function, intended to be put in the *note
     tp_call: 77c. slot or be used in an implementation of ‘tp_call’.
     It does not check the *note Py_TPFLAGS_HAVE_VECTORCALL: 777. flag
     and it does not fall back to ‘tp_call’.

     Added in version 3.8.


File: python.info,  Node: Object Calling API,  Next: Call Support API,  Prev: The Vectorcall Protocol,  Up: Call Protocol

7.8.2.5 Object Calling API
..........................

Various functions are available for calling a Python object.  Each
converts its arguments to a convention supported by the called object –
either 'tp_call' or vectorcall.  In order to do as little conversion as
possible, pick one that best fits the format of data you have available.

The following table summarizes the available functions; please see
individual documentation for details.

Function                                       callable               args                     kwargs
                                                                                               
-------------------------------------------------------------------------------------------------------------------
                                                                                               
*note PyObject_Call(): 63d.                    ‘PyObject *’           tuple                    dict/‘NULL’
                                                                                               
                                                                                               
*note PyObject_CallNoArgs(): 63c.              ‘PyObject *’           —                        —
                                                                                               
                                                                                               
*note PyObject_CallOneArg(): b71.              ‘PyObject *’           1 object                 —
                                                                                               
                                                                                               
*note PyObject_CallObject(): 4e95.             ‘PyObject *’           tuple/‘NULL’             —
                                                                                               
                                                                                               
*note PyObject_CallFunction(): 63f.            ‘PyObject *’           format                   —
                                                                                               
                                                                                               
*note PyObject_CallMethod(): 640.              obj + ‘char*’          format                   —
                                                                                               
                                                                                               
*note PyObject_CallFunctionObjArgs(): 5061.    ‘PyObject *’           variadic                 —
                                                                                               
                                                                                               
*note PyObject_CallMethodObjArgs(): 1dc7.      obj + name             variadic                 —
                                                                                               
                                                                                               
*note PyObject_CallMethodNoArgs(): 5273.       obj + name             —                        —
                                                                                               
                                                                                               
*note PyObject_CallMethodOneArg(): 5274.       obj + name             1 object                 —
                                                                                               
                                                                                               
*note PyObject_Vectorcall(): 77f.              ‘PyObject *’           vectorcall               vectorcall
                                                                                               
                                                                                               
*note PyObject_VectorcallDict(): 5275.         ‘PyObject *’           vectorcall               dict/‘NULL’
                                                                                               
                                                                                               
*note PyObject_VectorcallMethod(): 780.        arg + name             vectorcall               vectorcall
                                                                                               

 -- C Funzione: *note PyObject: 5df. *PyObject_Call (PyObject *callable,
          PyObject *args, PyObject *kwargs)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Call a callable Python object 'callable', with
     arguments given by the tuple 'args', and named arguments given by
     the dictionary 'kwargs'.

     'args' must not be 'NULL'; use an empty tuple if no arguments are
     needed.  If no named arguments are needed, 'kwargs' can be 'NULL'.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

     This is the equivalent of the Python expression: ‘callable(*args,
     **kwargs)’.

 -- C Funzione: *note PyObject: 5df. *PyObject_CallNoArgs (PyObject
          *callable)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.10.'  Call a callable Python object
     'callable' without any arguments.  It is the most efficient way to
     call a callable Python object without any argument.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

     Added in version 3.9.

 -- C Funzione: *note PyObject: 5df. *PyObject_CallOneArg (PyObject
          *callable, PyObject *arg)
     'Valore di ritorno: Nuovo riferimento.'  Call a callable Python
     object 'callable' with exactly 1 positional argument 'arg' and no
     keyword arguments.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

     Added in version 3.9.

 -- C Funzione: *note PyObject: 5df. *PyObject_CallObject (PyObject
          *callable, PyObject *args)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Call a callable Python object 'callable', with
     arguments given by the tuple 'args'.  If no arguments are needed,
     then 'args' can be 'NULL'.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

     This is the equivalent of the Python expression: ‘callable(*args)’.

 -- C Funzione: *note PyObject: 5df. *PyObject_CallFunction (PyObject
          *callable, const char *format, ...)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Call a callable Python object 'callable', with a
     variable number of C arguments.  The C arguments are described
     using a *note Py_BuildValue(): 3c2. style format string.  The
     format can be 'NULL', indicating that no arguments are provided.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

     This is the equivalent of the Python expression: ‘callable(*args)’.

     Note that if you only pass *note PyObject: 5df.* args, *note
     PyObject_CallFunctionObjArgs(): 5061. is a faster alternative.

     Cambiato nella versione 3.4: The type of 'format' was changed from
     ‘char *’.

 -- C Funzione: *note PyObject: 5df. *PyObject_CallMethod (PyObject
          *obj, const char *name, const char *format, ...)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Call the method named 'name' of object 'obj' with a
     variable number of C arguments.  The C arguments are described by a
     *note Py_BuildValue(): 3c2. format string that should produce a
     tuple.

     The format can be 'NULL', indicating that no arguments are
     provided.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

     This is the equivalent of the Python expression: ‘obj.name(arg1,
     arg2, ...)’.

     Note that if you only pass *note PyObject: 5df.* args, *note
     PyObject_CallMethodObjArgs(): 1dc7. is a faster alternative.

     Cambiato nella versione 3.4: The types of 'name' and 'format' were
     changed from ‘char *’.

 -- C Funzione: *note PyObject: 5df. *PyObject_CallFunctionObjArgs
          (PyObject *callable, ...)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Call a callable Python object 'callable', with a
     variable number of *note PyObject: 5df.* arguments.  The arguments
     are provided as a variable number of parameters followed by 'NULL'.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

     This is the equivalent of the Python expression: ‘callable(arg1,
     arg2, ...)’.

 -- C Funzione: *note PyObject: 5df. *PyObject_CallMethodObjArgs
          (PyObject *obj, PyObject *name, ...)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Call a method of the Python object 'obj', where the
     name of the method is given as a Python string object in 'name'.
     It is called with a variable number of *note PyObject: 5df.*
     arguments.  The arguments are provided as a variable number of
     parameters followed by 'NULL'.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

 -- C Funzione: *note PyObject: 5df. *PyObject_CallMethodNoArgs
          (PyObject *obj, PyObject *name)

     Call a method of the Python object 'obj' without arguments, where
     the name of the method is given as a Python string object in
     'name'.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

     Added in version 3.9.

 -- C Funzione: *note PyObject: 5df. *PyObject_CallMethodOneArg
          (PyObject *obj, PyObject *name, PyObject *arg)

     Call a method of the Python object 'obj' with a single positional
     argument 'arg', where the name of the method is given as a Python
     string object in 'name'.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

     Added in version 3.9.

 -- C Funzione: *note PyObject: 5df. *PyObject_Vectorcall (PyObject
          *callable, PyObject *const *args, size_t nargsf, PyObject
          *kwnames)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Call a
     callable Python object 'callable'.  The arguments are the same as
     for *note vectorcallfunc: 77a.  If 'callable' supports *note
     vectorcall: 775, this directly calls the vectorcall function stored
     in 'callable'.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

     Added in version 3.8: as ‘_PyObject_Vectorcall’

     Cambiato nella versione 3.9: Renamed to the current name, without
     the leading underscore.  The old provisional name is *note soft
     deprecated: 23d.

 -- C Funzione: *note PyObject: 5df. *PyObject_VectorcallDict (PyObject
          *callable, PyObject *const *args, size_t nargsf, PyObject
          *kwdict)

     Call 'callable' with positional arguments passed exactly as in the
     *note vectorcall: 775. protocol, but with keyword arguments passed
     as a dictionary 'kwdict'.  The 'args' array contains only the
     positional arguments.

     Regardless of which protocol is used internally, a conversion of
     arguments needs to be done.  Therefore, this function should only
     be used if the caller already has a dictionary ready to use for the
     keyword arguments, but not a tuple for the positional arguments.

     Added in version 3.9.

 -- C Funzione: *note PyObject: 5df. *PyObject_VectorcallMethod
          (PyObject *name, PyObject *const *args, size_t nargsf,
          PyObject *kwnames)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Call a
     method using the vectorcall calling convention.  The name of the
     method is given as a Python string 'name'.  The object whose method
     is called is 'args[0]', and the 'args' array starting at 'args[1]'
     represents the arguments of the call.  There must be at least one
     positional argument.  'nargsf' is the number of positional
     arguments including 'args[0]', plus *note
     PY_VECTORCALL_ARGUMENTS_OFFSET: 781. if the value of ‘args[0]’ may
     temporarily be changed.  Keyword arguments can be passed just like
     in *note PyObject_Vectorcall(): 77f.

     If the object has the *note Py_TPFLAGS_METHOD_DESCRIPTOR: 5110.
     feature, this will call the unbound method object with the full
     'args' vector as arguments.

     Return the result of the call on success, or raise an exception and
     return 'NULL' on failure.

     Added in version 3.9.


File: python.info,  Node: Call Support API,  Prev: Object Calling API,  Up: Call Protocol

7.8.2.6 Call Support API
........................

 -- C Funzione: int PyCallable_Check (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Determine if the object 'o'
     is callable.  Return ‘1’ if the object is callable and ‘0’
     otherwise.  This function always succeeds.


File: python.info,  Node: Number Protocol,  Next: Sequence Protocol,  Prev: Call Protocol,  Up: Abstract Objects Layer

7.8.3 Number Protocol
---------------------

 -- C Funzione: int PyNumber_Check (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Returns ‘1’ if the object 'o'
     provides numeric protocols, and false otherwise.  This function
     always succeeds.

     Cambiato nella versione 3.8: Returns ‘1’ if 'o' is an index
     integer.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Add (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the result of adding 'o1' and 'o2', or
     ‘NULL’ on failure.  This is the equivalent of the Python expression
     ‘o1 + o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Subtract (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the result of subtracting 'o2' from 'o1',
     or ‘NULL’ on failure.  This is the equivalent of the Python
     expression ‘o1 - o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Multiply (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the result of multiplying 'o1' and 'o2', or
     ‘NULL’ on failure.  This is the equivalent of the Python expression
     ‘o1 * o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_MatrixMultiply (PyObject
          *o1, PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'  Returns the result of matrix
     multiplication on 'o1' and 'o2', or ‘NULL’ on failure.  This is the
     equivalent of the Python expression ‘o1 @ o2’.

     Added in version 3.5.

 -- C Funzione: *note PyObject: 5df. *PyNumber_FloorDivide (PyObject
          *o1, PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the floor of 'o1' divided by 'o2', or ‘NULL’
     on failure.  This is the equivalent of the Python expression ‘o1 //
     o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_TrueDivide (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a reasonable approximation for the
     mathematical value of 'o1' divided by 'o2', or ‘NULL’ on failure.
     The return value is «approximate» because binary floating-point
     numbers are approximate; it is not possible to represent all real
     numbers in base two.  This function can return a floating-point
     value when passed two integers.  This is the equivalent of the
     Python expression ‘o1 / o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Remainder (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the remainder of dividing 'o1' by 'o2', or
     ‘NULL’ on failure.  This is the equivalent of the Python expression
     ‘o1 % o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Divmod (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     See the built-in function *note divmod(): b9b.  Returns ‘NULL’ on
     failure.  This is the equivalent of the Python expression
     ‘divmod(o1, o2)’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Power (PyObject *o1,
          PyObject *o2, PyObject *o3)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     See the built-in function *note pow(): 1a4.  Returns ‘NULL’ on
     failure.  This is the equivalent of the Python expression ‘pow(o1,
     o2, o3)’, where 'o3' is optional.  If 'o3' is to be ignored, pass
     *note Py_None: 4e88. in its place (passing ‘NULL’ for 'o3' would
     cause an illegal memory access).

 -- C Funzione: *note PyObject: 5df. *PyNumber_Negative (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the negation of 'o' on success, or ‘NULL’
     on failure.  This is the equivalent of the Python expression ‘-o’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Positive (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns 'o' on success, or ‘NULL’ on failure.  This
     is the equivalent of the Python expression ‘+o’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Absolute (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     Returns the absolute value of 'o', or ‘NULL’ on failure.  This is
     the equivalent of the Python expression ‘abs(o)’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Invert (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the bitwise negation of 'o' on success, or
     ‘NULL’ on failure.  This is the equivalent of the Python expression
     ‘~o’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Lshift (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the result of left shifting 'o1' by 'o2' on
     success, or ‘NULL’ on failure.  This is the equivalent of the
     Python expression ‘o1 << o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Rshift (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the result of right shifting 'o1' by 'o2'
     on success, or ‘NULL’ on failure.  This is the equivalent of the
     Python expression ‘o1 >> o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_And (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the «bitwise and» of 'o1' and 'o2' on
     success and ‘NULL’ on failure.  This is the equivalent of the
     Python expression ‘o1 & o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Xor (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the «bitwise exclusive or» of 'o1' by 'o2'
     on success, or ‘NULL’ on failure.  This is the equivalent of the
     Python expression ‘o1 ^ o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Or (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the «bitwise or» of 'o1' and 'o2' on
     success, or ‘NULL’ on failure.  This is the equivalent of the
     Python expression ‘o1 | o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceAdd (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the result of adding 'o1' and 'o2', or
     ‘NULL’ on failure.  The operation is done 'in-place' when 'o1'
     supports it.  This is the equivalent of the Python statement ‘o1 +=
     o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceSubtract (PyObject
          *o1, PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the result of subtracting 'o2' from 'o1',
     or ‘NULL’ on failure.  The operation is done 'in-place' when 'o1'
     supports it.  This is the equivalent of the Python statement ‘o1 -=
     o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceMultiply (PyObject
          *o1, PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the result of multiplying 'o1' and 'o2', or
     ‘NULL’ on failure.  The operation is done 'in-place' when 'o1'
     supports it.  This is the equivalent of the Python statement ‘o1 *=
     o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceMatrixMultiply
          (PyObject *o1, PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'  Returns the result of matrix
     multiplication on 'o1' and 'o2', or ‘NULL’ on failure.  The
     operation is done 'in-place' when 'o1' supports it.  This is the
     equivalent of the Python statement ‘o1 @= o2’.

     Added in version 3.5.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceFloorDivide
          (PyObject *o1, PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the mathematical floor of dividing 'o1' by
     'o2', or ‘NULL’ on failure.  The operation is done 'in-place' when
     'o1' supports it.  This is the equivalent of the Python statement
     ‘o1 //= o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceTrueDivide
          (PyObject *o1, PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a reasonable approximation for the
     mathematical value of 'o1' divided by 'o2', or ‘NULL’ on failure.
     The return value is «approximate» because binary floating-point
     numbers are approximate; it is not possible to represent all real
     numbers in base two.  This function can return a floating-point
     value when passed two integers.  The operation is done 'in-place'
     when 'o1' supports it.  This is the equivalent of the Python
     statement ‘o1 /= o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceRemainder
          (PyObject *o1, PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the remainder of dividing 'o1' by 'o2', or
     ‘NULL’ on failure.  The operation is done 'in-place' when 'o1'
     supports it.  This is the equivalent of the Python statement ‘o1 %=
     o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlacePower (PyObject
          *o1, PyObject *o2, PyObject *o3)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     See the built-in function *note pow(): 1a4.  Returns ‘NULL’ on
     failure.  The operation is done 'in-place' when 'o1' supports it.
     This is the equivalent of the Python statement ‘o1 **= o2’ when o3
     is *note Py_None: 4e88, or an in-place variant of ‘pow(o1, o2, o3)’
     otherwise.  If 'o3' is to be ignored, pass *note Py_None: 4e88. in
     its place (passing ‘NULL’ for 'o3' would cause an illegal memory
     access).

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceLshift (PyObject
          *o1, PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the result of left shifting 'o1' by 'o2' on
     success, or ‘NULL’ on failure.  The operation is done 'in-place'
     when 'o1' supports it.  This is the equivalent of the Python
     statement ‘o1 <<= o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceRshift (PyObject
          *o1, PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the result of right shifting 'o1' by 'o2'
     on success, or ‘NULL’ on failure.  The operation is done 'in-place'
     when 'o1' supports it.  This is the equivalent of the Python
     statement ‘o1 >>= o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceAnd (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the «bitwise and» of 'o1' and 'o2' on
     success and ‘NULL’ on failure.  The operation is done 'in-place'
     when 'o1' supports it.  This is the equivalent of the Python
     statement ‘o1 &= o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceXor (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the «bitwise exclusive or» of 'o1' by 'o2'
     on success, or ‘NULL’ on failure.  The operation is done 'in-place'
     when 'o1' supports it.  This is the equivalent of the Python
     statement ‘o1 ^= o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_InPlaceOr (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the «bitwise or» of 'o1' and 'o2' on
     success, or ‘NULL’ on failure.  The operation is done 'in-place'
     when 'o1' supports it.  This is the equivalent of the Python
     statement ‘o1 |= o2’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Long (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     Returns the 'o' converted to an integer object on success, or
     ‘NULL’ on failure.  This is the equivalent of the Python expression
     ‘int(o)’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Float (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     Returns the 'o' converted to a float object on success, or ‘NULL’
     on failure.  This is the equivalent of the Python expression
     ‘float(o)’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_Index (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the 'o' converted to a Python int on
     success or ‘NULL’ with a *note TypeError: 198. exception raised on
     failure.

     Cambiato nella versione 3.10: The result always has exact type
     *note int: 19b.  Previously, the result could have been an instance
     of a subclass of ‘int’.

 -- C Funzione: *note PyObject: 5df. *PyNumber_ToBase (PyObject *n, int
          base)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Returns the integer 'n' converted to base 'base' as
     a string.  The 'base' argument must be one of 2, 8, 10, or 16.  For
     base 2, 8, or 16, the returned string is prefixed with a base
     marker of ‘'0b'’, ‘'0o'’, or ‘'0x'’, respectively.  If 'n' is not a
     Python int, it is converted with *note PyNumber_Index(): a95.
     first.

 -- C Funzione: *note Py_ssize_t: c57. PyNumber_AsSsize_t (PyObject *o,
          PyObject *exc)
     ' Parte del *note ABI Stabile: 776.'  Returns 'o' converted to a
     *note Py_ssize_t: c57. value if 'o' can be interpreted as an
     integer.  If the call fails, an exception is raised and ‘-1’ is
     returned.

     If 'o' can be converted to a Python int but the attempt to convert
     to a *note Py_ssize_t: c57. value would raise an *note
     OverflowError: a83, then the 'exc' argument is the type of
     exception that will be raised (usually *note IndexError: 173c. or
     *note OverflowError: a83.).  If 'exc' is ‘NULL’, then the exception
     is cleared and the value is clipped to ‘PY_SSIZE_T_MIN’ for a
     negative integer or ‘PY_SSIZE_T_MAX’ for a positive integer.

 -- C Funzione: int PyIndex_Check (PyObject *o)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.8.'  Returns
     ‘1’ if 'o' is an index integer (has the ‘nb_index’ slot of the
     ‘tp_as_number’ structure filled in), and ‘0’ otherwise.  This
     function always succeeds.


File: python.info,  Node: Sequence Protocol,  Next: Mapping Protocol,  Prev: Number Protocol,  Up: Abstract Objects Layer

7.8.4 Sequence Protocol
-----------------------

 -- C Funzione: int PySequence_Check (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Return ‘1’ if the object
     provides the sequence protocol, and ‘0’ otherwise.  Note that it
     returns ‘1’ for Python classes with a *note __getitem__(): 588.
     method, unless they are *note dict: 183. subclasses, since in
     general it is impossible to determine what type of keys the class
     supports.  This function always succeeds.

 -- C Funzione: *note Py_ssize_t: c57. PySequence_Size (PyObject *o)
 -- C Funzione: *note Py_ssize_t: c57. PySequence_Length (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'

     Returns the number of objects in sequence 'o' on success, and ‘-1’
     on failure.  This is equivalent to the Python expression ‘len(o)’.

 -- C Funzione: *note PyObject: 5df. *PySequence_Concat (PyObject *o1,
          PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the concatenation of 'o1' and 'o2' on
     success, and ‘NULL’ on failure.  This is the equivalent of the
     Python expression ‘o1 + o2’.

 -- C Funzione: *note PyObject: 5df. *PySequence_Repeat (PyObject *o,
          Py_ssize_t count)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the result of repeating sequence object 'o'
     'count' times, or ‘NULL’ on failure.  This is the equivalent of the
     Python expression ‘o * count’.

 -- C Funzione: *note PyObject: 5df. *PySequence_InPlaceConcat (PyObject
          *o1, PyObject *o2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the concatenation of 'o1' and 'o2' on
     success, and ‘NULL’ on failure.  The operation is done 'in-place'
     when 'o1' supports it.  This is the equivalent of the Python
     expression ‘o1 += o2’.

 -- C Funzione: *note PyObject: 5df. *PySequence_InPlaceRepeat (PyObject
          *o, Py_ssize_t count)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the result of repeating sequence object 'o'
     'count' times, or ‘NULL’ on failure.  The operation is done
     'in-place' when 'o' supports it.  This is the equivalent of the
     Python expression ‘o *= count’.

 -- C Funzione: *note PyObject: 5df. *PySequence_GetItem (PyObject *o,
          Py_ssize_t i)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the 'i'th element of 'o', or ‘NULL’ on
     failure.  This is the equivalent of the Python expression ‘o[i]’.

 -- C Funzione: *note PyObject: 5df. *PySequence_GetSlice (PyObject *o,
          Py_ssize_t i1, Py_ssize_t i2)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the slice of sequence object 'o' between
     'i1' and 'i2', or ‘NULL’ on failure.  This is the equivalent of the
     Python expression ‘o[i1:i2]’.

 -- C Funzione: int PySequence_SetItem (PyObject *o, Py_ssize_t i,
          PyObject *v)
     ' Parte del *note ABI Stabile: 776.'  Assign object 'v' to the
     'i'th element of 'o'.  Raise an exception and return ‘-1’ on
     failure; return ‘0’ on success.  This is the equivalent of the
     Python statement ‘o[i] = v’.  This function 'does not' steal a
     reference to 'v'.

     If 'v' is ‘NULL’, the element is deleted, but this feature is
     deprecated in favour of using *note PySequence_DelItem(): 1e1e.

 -- C Funzione: int PySequence_DelItem (PyObject *o, Py_ssize_t i)
     ' Parte del *note ABI Stabile: 776.'  Delete the 'i'th element of
     object 'o'.  Returns ‘-1’ on failure.  This is the equivalent of
     the Python statement ‘del o[i]’.

 -- C Funzione: int PySequence_SetSlice (PyObject *o, Py_ssize_t i1,
          Py_ssize_t i2, PyObject *v)
     ' Parte del *note ABI Stabile: 776.'  Assign the sequence object
     'v' to the slice in sequence object 'o' from 'i1' to 'i2'.  This is
     the equivalent of the Python statement ‘o[i1:i2] = v’.

 -- C Funzione: int PySequence_DelSlice (PyObject *o, Py_ssize_t i1,
          Py_ssize_t i2)
     ' Parte del *note ABI Stabile: 776.'  Delete the slice in sequence
     object 'o' from 'i1' to 'i2'.  Returns ‘-1’ on failure.  This is
     the equivalent of the Python statement ‘del o[i1:i2]’.

 -- C Funzione: *note Py_ssize_t: c57. PySequence_Count (PyObject *o,
          PyObject *value)
     ' Parte del *note ABI Stabile: 776.'  Return the number of
     occurrences of 'value' in 'o', that is, return the number of keys
     for which ‘o[key] == value’.  On failure, return ‘-1’.  This is
     equivalent to the Python expression ‘o.count(value)’.

 -- C Funzione: int PySequence_Contains (PyObject *o, PyObject *value)
     ' Parte del *note ABI Stabile: 776.'  Determine if 'o' contains
     'value'.  If an item in 'o' is equal to 'value', return ‘1’,
     otherwise return ‘0’.  On error, return ‘-1’.  This is equivalent
     to the Python expression ‘value in o’.

 -- C Funzione: int PySequence_In (PyObject *o, PyObject *value)
     ' Parte del *note ABI Stabile: 776.'  Alias for *note
     PySequence_Contains(): 3d9.

     Deprecato dalla versione 3.14: The function is *note soft
     deprecated: 23d. and should no longer be used to write new code.

 -- C Funzione: *note Py_ssize_t: c57. PySequence_Index (PyObject *o,
          PyObject *value)
     ' Parte del *note ABI Stabile: 776.'  Return the first index 'i'
     for which ‘o[i] == value’.  On error, return ‘-1’.  This is
     equivalent to the Python expression ‘o.index(value)’.

 -- C Funzione: *note PyObject: 5df. *PySequence_List (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a list object with the same contents as the
     sequence or iterable 'o', or ‘NULL’ on failure.  The returned list
     is guaranteed to be new.  This is equivalent to the Python
     expression ‘list(o)’.

 -- C Funzione: *note PyObject: 5df. *PySequence_Tuple (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     Return a tuple object with the same contents as the sequence or
     iterable 'o', or ‘NULL’ on failure.  If 'o' is a tuple, a new
     reference will be returned, otherwise a tuple will be constructed
     with the appropriate contents.  This is equivalent to the Python
     expression ‘tuple(o)’.

 -- C Funzione: *note PyObject: 5df. *PySequence_Fast (PyObject *o,
          const char *m)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the sequence or iterable 'o' as an object
     usable by the other ‘PySequence_Fast*’ family of functions.  If the
     object is not a sequence or iterable, raises *note TypeError: 198.
     with 'm' as the message text.  Returns ‘NULL’ on failure.

     The ‘PySequence_Fast*’ functions are thus named because they assume
     'o' is a *note PyTupleObject: 51fc. or a *note PyListObject: 5280.
     and access the data fields of 'o' directly.

     As a CPython implementation detail, if 'o' is already a sequence or
     list, it will be returned.

 -- C Funzione: *note Py_ssize_t: c57. PySequence_Fast_GET_SIZE
          (PyObject *o)

     Returns the length of 'o', assuming that 'o' was returned by *note
     PySequence_Fast(): 188a. and that 'o' is not ‘NULL’.  The size can
     also be retrieved by calling *note PySequence_Size(): 1e1b. on 'o',
     but *note PySequence_Fast_GET_SIZE(): 3ca. is faster because it can
     assume 'o' is a list or tuple.

 -- C Funzione: *note PyObject: 5df. *PySequence_Fast_GET_ITEM (PyObject
          *o, Py_ssize_t i)
     'Valore di ritorno: Riferimento preso in prestito.'  Return the
     'i'th element of 'o', assuming that 'o' was returned by *note
     PySequence_Fast(): 188a, 'o' is not ‘NULL’, and that 'i' is within
     bounds.

 -- C Funzione: *note PyObject: 5df. **PySequence_Fast_ITEMS (PyObject
          *o)

     Return the underlying array of PyObject pointers.  Assumes that 'o'
     was returned by *note PySequence_Fast(): 188a. and 'o' is not
     ‘NULL’.

     Note, if a list gets resized, the reallocation may relocate the
     items array.  So, only use the underlying array pointer in contexts
     where the sequence cannot change.

 -- C Funzione: *note PyObject: 5df. *PySequence_ITEM (PyObject *o,
          Py_ssize_t i)
     'Valore di ritorno: Nuovo riferimento.'  Return the 'i'th element
     of 'o' or ‘NULL’ on failure.  Faster form of *note
     PySequence_GetItem(): 1e1c. but without checking that *note
     PySequence_Check(): 5078. on 'o' is true and without adjustment for
     negative indices.


File: python.info,  Node: Mapping Protocol,  Next: Iterator Protocol,  Prev: Sequence Protocol,  Up: Abstract Objects Layer

7.8.5 Mapping Protocol
----------------------

See also *note PyObject_GetItem(): 5ea, *note PyObject_SetItem(): 4f20.
and *note PyObject_DelItem(): 5062.

 -- C Funzione: int PyMapping_Check (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Return ‘1’ if the object
     provides the mapping protocol or supports slicing, and ‘0’
     otherwise.  Note that it returns ‘1’ for Python classes with a
     *note __getitem__(): 588. method, since in general it is impossible
     to determine what type of keys the class supports.  This function
     always succeeds.

 -- C Funzione: *note Py_ssize_t: c57. PyMapping_Size (PyObject *o)
 -- C Funzione: *note Py_ssize_t: c57. PyMapping_Length (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'

     Returns the number of keys in object 'o' on success, and ‘-1’ on
     failure.  This is equivalent to the Python expression ‘len(o)’.

 -- C Funzione: *note PyObject: 5df. *PyMapping_GetItemString (PyObject
          *o, const char *key)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This is the same as *note PyObject_GetItem(): 5ea,
     but 'key' is specified as a const char* UTF-8 encoded bytes string,
     rather than a *note PyObject: 5df.*.

 -- C Funzione: int PyMapping_GetOptionalItem (PyObject *obj, PyObject
          *key, PyObject **result)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Variant
     of *note PyObject_GetItem(): 5ea. which doesn’t raise *note
     KeyError: 5e7. if the key is not found.

     If the key is found, return ‘1’ and set '*result' to a new *note
     strong reference: 5e2. to the corresponding value.  If the key is
     not found, return ‘0’ and set '*result' to ‘NULL’; the *note
     KeyError: 5e7. is silenced.  If an error other than *note KeyError:
     5e7. is raised, return ‘-1’ and set '*result' to ‘NULL’.

     Added in version 3.13.

 -- C Funzione: int PyMapping_GetOptionalItemString (PyObject *obj,
          const char *key, PyObject **result)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  This is
     the same as *note PyMapping_GetOptionalItem(): 5e8, but 'key' is
     specified as a const char* UTF-8 encoded bytes string, rather than
     a *note PyObject: 5df.*.

     Added in version 3.13.

 -- C Funzione: int PyMapping_SetItemString (PyObject *o, const char
          *key, PyObject *v)
     ' Parte del *note ABI Stabile: 776.'  This is the same as *note
     PyObject_SetItem(): 4f20, but 'key' is specified as a const char*
     UTF-8 encoded bytes string, rather than a *note PyObject: 5df.*.

 -- C Funzione: int PyMapping_DelItem (PyObject *o, PyObject *key)

     This is an alias of *note PyObject_DelItem(): 5062.

 -- C Funzione: int PyMapping_DelItemString (PyObject *o, const char
          *key)

     This is the same as *note PyObject_DelItem(): 5062, but 'key' is
     specified as a const char* UTF-8 encoded bytes string, rather than
     a *note PyObject: 5df.*.

 -- C Funzione: int PyMapping_HasKeyWithError (PyObject *o, PyObject
          *key)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Return
     ‘1’ if the mapping object has the key 'key' and ‘0’ otherwise.
     This is equivalent to the Python expression ‘key in o’.  On
     failure, return ‘-1’.

     Added in version 3.13.

 -- C Funzione: int PyMapping_HasKeyStringWithError (PyObject *o, const
          char *key)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  This is
     the same as *note PyMapping_HasKeyWithError(): 61f, but 'key' is
     specified as a const char* UTF-8 encoded bytes string, rather than
     a *note PyObject: 5df.*.

     Added in version 3.13.

 -- C Funzione: int PyMapping_HasKey (PyObject *o, PyObject *key)
     ' Parte del *note ABI Stabile: 776.'  Return ‘1’ if the mapping
     object has the key 'key' and ‘0’ otherwise.  This is equivalent to
     the Python expression ‘key in o’.  This function always succeeds.

          Nota: Exceptions which occur when this calls the *note
          __getitem__(): 588. method are silently ignored.  For proper
          error handling, use *note PyMapping_HasKeyWithError(): 61f,
          *note PyMapping_GetOptionalItem(): 5e8. or *note
          PyObject_GetItem(): 5ea. instead.

 -- C Funzione: int PyMapping_HasKeyString (PyObject *o, const char
          *key)
     ' Parte del *note ABI Stabile: 776.'  This is the same as *note
     PyMapping_HasKey(): 620, but 'key' is specified as a const char*
     UTF-8 encoded bytes string, rather than a *note PyObject: 5df.*.

          Nota: Exceptions that occur when this calls the *note
          __getitem__(): 588. method or while creating the temporary
          *note str: 169. object are silently ignored.  For proper error
          handling, use *note PyMapping_HasKeyStringWithError(): 621,
          *note PyMapping_GetOptionalItemString(): 5e9. or *note
          PyMapping_GetItemString(): 5eb. instead.

 -- C Funzione: *note PyObject: 5df. *PyMapping_Keys (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  On success, return a list of the keys in object
     'o'.  On failure, return ‘NULL’.

     Cambiato nella versione 3.7: Previously, the function returned a
     list or a tuple.

 -- C Funzione: *note PyObject: 5df. *PyMapping_Values (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  On success, return a list of the values in object
     'o'.  On failure, return ‘NULL’.

     Cambiato nella versione 3.7: Previously, the function returned a
     list or a tuple.

 -- C Funzione: *note PyObject: 5df. *PyMapping_Items (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  On success, return a list of the items in object
     'o', where each item is a tuple containing a key-value pair.  On
     failure, return ‘NULL’.

     Cambiato nella versione 3.7: Previously, the function returned a
     list or a tuple.


File: python.info,  Node: Iterator Protocol,  Next: Buffer Protocol,  Prev: Mapping Protocol,  Up: Abstract Objects Layer

7.8.6 Iterator Protocol
-----------------------

There are two functions specifically for working with iterators.

 -- C Funzione: int PyIter_Check (PyObject *o)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.8.'  Return
     non-zero if the object 'o' can be safely passed to *note
     PyIter_NextItem(): 398. and ‘0’ otherwise.  This function always
     succeeds.

 -- C Funzione: int PyAIter_Check (PyObject *o)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Return
     non-zero if the object 'o' provides the ‘AsyncIterator’ protocol,
     and ‘0’ otherwise.  This function always succeeds.

     Added in version 3.10.

 -- C Funzione: int PyIter_NextItem (PyObject *iter, PyObject **item)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Return
     ‘1’ and set 'item' to a *note strong reference: 5e2. of the next
     value of the iterator 'iter' on success.  Return ‘0’ and set 'item'
     to ‘NULL’ if there are no remaining values.  Return ‘-1’, set
     'item' to ‘NULL’ and set an exception on error.

     Added in version 3.14.

 -- C Funzione: *note PyObject: 5df. *PyIter_Next (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  This is an older version of ‘PyIter_NextItem()’,
     which is retained for backwards compatibility.  Prefer *note
     PyIter_NextItem(): 398.

     Return the next value from the iterator 'o'.  The object must be an
     iterator according to *note PyIter_Check(): 1c9a. (it is up to the
     caller to check this).  If there are no remaining values, returns
     ‘NULL’ with no exception set.  If an error occurs while retrieving
     the item, returns ‘NULL’ and passes along the exception.

 -- C Tipo: type PySendResult

     The enum value used to represent different results of *note
     PyIter_Send(): a9a.

     Added in version 3.10.

 -- C Funzione: *note PySendResult: 528c. PyIter_Send (PyObject *iter,
          PyObject *arg, PyObject **presult)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Sends
     the 'arg' value into the iterator 'iter'.  Returns:

        - ‘PYGEN_RETURN’ if iterator returns.  Return value is returned
          via 'presult'.

        - ‘PYGEN_NEXT’ if iterator yields.  Yielded value is returned
          via 'presult'.

        - ‘PYGEN_ERROR’ if iterator has raised and exception.  'presult'
          is set to ‘NULL’.

     Added in version 3.10.


File: python.info,  Node: Buffer Protocol,  Prev: Iterator Protocol,  Up: Abstract Objects Layer

7.8.7 Buffer Protocol
---------------------

Certain objects available in Python wrap access to an underlying memory
array or 'buffer'.  Such objects include the built-in *note bytes: 192.
and *note bytearray: 344, and some extension types like *note
array.array: 4bf.  Third-party libraries may define their own types for
special purposes, such as image processing or numeric analysis.

While each of these types have their own semantics, they share the
common characteristic of being backed by a possibly large memory buffer.
It is then desirable, in some situations, to access that buffer directly
and without intermediate copying.

Python provides such a facility at the C and Python level in the form of
the *note buffer protocol: 260.  This protocol has two sides:

   - on the producer side, a type can export a «buffer interface» which
     allows objects of that type to expose information about their
     underlying buffer.  This interface is described in the section
     *note Buffer Object Structures: 5290.; for Python see *note
     Emulating buffer types: 23f4.

   - on the consumer side, several means are available to obtain a
     pointer to the raw underlying data of an object (for example a
     method parameter).  For Python see *note memoryview: 165.

Simple objects such as *note bytes: 192. and *note bytearray: 344.
expose their underlying buffer in byte-oriented form.  Other forms are
possible; for example, the elements exposed by an *note array.array:
4bf. can be multi-byte values.

An example consumer of the buffer interface is the *note write(): ed9.
method of file objects: any object that can export a series of bytes
through the buffer interface can be written to a file.  While ‘write()’
only needs read-only access to the internal contents of the object
passed to it, other methods such as *note readinto(): 187d. need write
access to the contents of their argument.  The buffer interface allows
objects to selectively allow or reject exporting of read-write and
read-only buffers.

There are two ways for a consumer of the buffer interface to acquire a
buffer over a target object:

   * call *note PyObject_GetBuffer(): 63a. with the right parameters;

   * call *note PyArg_ParseTuple(): 3c1. (or one of its siblings) with
     one of the ‘y*’, ‘w*’ or ‘s*’ *note format codes: 3d5.

In both cases, *note PyBuffer_Release(): 63b. must be called when the
buffer isn’t needed anymore.  Failure to do so could lead to various
issues such as resource leaks.

Added in version 3.12: The buffer protocol is now accessible in Python,
see *note Emulating buffer types: 23f4. and *note memoryview: 165.

* Menu:

* Buffer structure::
* Buffer request types::
* Complex arrays::
* Buffer-related functions::


File: python.info,  Node: Buffer structure,  Next: Buffer request types,  Up: Buffer Protocol

7.8.7.1 Buffer structure
........................

Buffer structures (or simply «buffers») are useful as a way to expose
the binary data from another object to the Python programmer.  They can
also be used as a zero-copy slicing mechanism.  Using their ability to
reference a block of memory, it is possible to expose any data to the
Python programmer quite easily.  The memory could be a large, constant
array in a C extension, it could be a raw block of memory for
manipulation before passing to an operating system library, or it could
be used to pass around structured data in its native, in-memory format.

Contrary to most data types exposed by the Python interpreter, buffers
are not *note PyObject: 5df. pointers but rather simple C structures.
This allows them to be created and copied very simply.  When a generic
wrapper around a buffer is needed, a *note memoryview: 5293. object can
be created.

For short instructions how to write an exporting object, see *note
Buffer Object Structures: 5290.  For obtaining a buffer, see *note
PyObject_GetBuffer(): 63a.

 -- C Tipo: type Py_buffer
     ' Parte del *note ABI Stabile: 776. (inclusi tutti i membri) dalla
     versione 3.11.'
      -- C Membro: void *buf

          A pointer to the start of the logical structure described by
          the buffer fields.  This can be any location within the
          underlying physical memory block of the exporter.  For
          example, with negative *note strides: 5295. the value may
          point to the end of the memory block.

          For *note contiguous: 2669. arrays, the value points to the
          beginning of the memory block.

      -- C Membro: *note PyObject: 5df. *obj

          A new reference to the exporting object.  The reference is
          owned by the consumer and automatically released (i.e.
          reference count decremented) and set to ‘NULL’ by *note
          PyBuffer_Release(): 63b.  The field is the equivalent of the
          return value of any standard C-API function.

          As a special case, for 'temporary' buffers that are wrapped by
          *note PyMemoryView_FromBuffer(): 966. or *note
          PyBuffer_FillInfo(): 965. this field is ‘NULL’.  In general,
          exporting objects MUST NOT use this scheme.

      -- C Membro: *note Py_ssize_t: c57. len

          ‘product(shape) * itemsize’.  For contiguous arrays, this is
          the length of the underlying memory block.  For non-contiguous
          arrays, it is the length that the logical structure would have
          if it were copied to a contiguous representation.

          Accessing ‘((char *)buf)[0] up to ((char *)buf)[len-1]’ is
          only valid if the buffer has been obtained by a request that
          guarantees contiguity.  In most cases such a request will be
          *note PyBUF_SIMPLE: 4f49. or *note PyBUF_WRITABLE: 15bd.

      -- C Membro: int readonly

          An indicator of whether the buffer is read-only.  This field
          is controlled by the *note PyBUF_WRITABLE: 15bd. flag.

      -- C Membro: *note Py_ssize_t: c57. itemsize

          Item size in bytes of a single element.  Same as the value of
          *note struct.calcsize(): 1d91. called on non-‘NULL’ *note
          format: 529a. values.

          Important exception: If a consumer requests a buffer without
          the *note PyBUF_FORMAT: 4f41. flag, *note format: 529a. will
          be set to ‘NULL’, but *note itemsize: 5299. still has the
          value for the original format.

          If *note shape: 529b. is present, the equality ‘product(shape)
          * itemsize == len’ still holds and the consumer can use *note
          itemsize: 5299. to navigate the buffer.

          If *note shape: 529b. is ‘NULL’ as a result of a *note
          PyBUF_SIMPLE: 4f49. or a *note PyBUF_WRITABLE: 15bd. request,
          the consumer must disregard *note itemsize: 5299. and assume
          ‘itemsize == 1’.

      -- C Membro: char *format

          A 'NULL' terminated string in *note struct: db. module style
          syntax describing the contents of a single item.  If this is
          ‘NULL’, ‘"B"’ (unsigned bytes) is assumed.

          This field is controlled by the *note PyBUF_FORMAT: 4f41.
          flag.

      -- C Membro: int ndim

          The number of dimensions the memory represents as an
          n-dimensional array.  If it is ‘0’, *note buf: 5294. points to
          a single item representing a scalar.  In this case, *note
          shape: 529b, *note strides: 5295. and *note suboffsets: 529d.
          MUST be ‘NULL’.  The maximum number of dimensions is given by
          *note PyBUF_MAX_NDIM: 4f45.

      -- C Membro: *note Py_ssize_t: c57. *shape

          An array of *note Py_ssize_t: c57. of length *note ndim: 529c.
          indicating the shape of the memory as an n-dimensional array.
          Note that ‘shape[0] * ... * shape[ndim-1] * itemsize’ MUST be
          equal to *note len: 5297.

          Shape values are restricted to ‘shape[n] >= 0’.  The case
          ‘shape[n] == 0’ requires special attention.  See *note complex
          arrays: 529e. for further information.

          The shape array is read-only for the consumer.

      -- C Membro: *note Py_ssize_t: c57. *strides

          An array of *note Py_ssize_t: c57. of length *note ndim: 529c.
          giving the number of bytes to skip to get to a new element in
          each dimension.

          Stride values can be any integer.  For regular arrays, strides
          are usually positive, but a consumer MUST be able to handle
          the case ‘strides[n] <= 0’.  See *note complex arrays: 529e.
          for further information.

          The strides array is read-only for the consumer.

      -- C Membro: *note Py_ssize_t: c57. *suboffsets

          An array of *note Py_ssize_t: c57. of length *note ndim: 529c.
          If ‘suboffsets[n] >= 0’, the values stored along the nth
          dimension are pointers and the suboffset value dictates how
          many bytes to add to each pointer after de-referencing.  A
          suboffset value that is negative indicates that no
          de-referencing should occur (striding in a contiguous memory
          block).

          If all suboffsets are negative (i.e.  no de-referencing is
          needed), then this field must be ‘NULL’ (the default value).

          This type of array representation is used by the Python
          Imaging Library (PIL). See *note complex arrays: 529e. for
          further information how to access elements of such an array.

          The suboffsets array is read-only for the consumer.

      -- C Membro: void *internal

          This is for use internally by the exporting object.  For
          example, this might be re-cast as an integer by the exporter
          and used to store flags about whether or not the shape,
          strides, and suboffsets arrays must be freed when the buffer
          is released.  The consumer MUST NOT alter this value.

Constants:

 -- C Macro: PyBUF_MAX_NDIM
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  The
     maximum number of dimensions the memory represents.  Exporters MUST
     respect this limit, consumers of multi-dimensional buffers SHOULD
     be able to handle up to ‘PyBUF_MAX_NDIM’ dimensions.  Currently set
     to 64.


File: python.info,  Node: Buffer request types,  Next: Complex arrays,  Prev: Buffer structure,  Up: Buffer Protocol

7.8.7.2 Buffer request types
............................

Buffers are usually obtained by sending a buffer request to an exporting
object via *note PyObject_GetBuffer(): 63a.  Since the complexity of the
logical structure of the memory can vary drastically, the consumer uses
the 'flags' argument to specify the exact buffer type it can handle.

All *note Py_buffer: 95d. fields are unambiguously defined by the
request type.

* Menu:

* request-independent fields::
* readonly, format: readonly format.
* shape, strides, suboffsets: shape strides suboffsets.
* contiguity requests::
* compound requests::


File: python.info,  Node: request-independent fields,  Next: readonly format,  Up: Buffer request types

7.8.7.3 request-independent fields
..................................

The following fields are not influenced by 'flags' and must always be
filled in with the correct values: *note obj: 5296, *note buf: 5294,
*note len: 5297, *note itemsize: 5299, *note ndim: 529c.


File: python.info,  Node: readonly format,  Next: shape strides suboffsets,  Prev: request-independent fields,  Up: Buffer request types

7.8.7.4 readonly, format
........................

      -- C Macro: PyBUF_WRITABLE
          ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'
          Controls the *note readonly: 5298. field.  If set, the
          exporter MUST provide a writable buffer or else report
          failure.  Otherwise, the exporter MAY provide either a
          read-only or writable buffer, but the choice MUST be
          consistent for all consumers.  For example, *note
          PyBUF_SIMPLE: 4f49. | *note PyBUF_WRITABLE: 15bd. can be used
          to request a simple writable buffer.

      -- C Macro: PyBUF_WRITEABLE

          This is a *note soft deprecated: 23d. alias to *note
          PyBUF_WRITABLE: 15bd.

      -- C Macro: PyBUF_FORMAT
          ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'
          Controls the *note format: 529a. field.  If set, this field
          MUST be filled in correctly.  Otherwise, this field MUST be
          ‘NULL’.

*note PyBUF_WRITABLE: 15bd. can be |”d to any of the flags in the next
section.  Since *note PyBUF_SIMPLE: 4f49. is defined as 0, *note
PyBUF_WRITABLE: 15bd. can be used as a stand-alone flag to request a
simple writable buffer.

*note PyBUF_FORMAT: 4f41. must be |”d to any of the flags except *note
PyBUF_SIMPLE: 4f49, because the latter already implies format ‘B’
(unsigned bytes).  ‘PyBUF_FORMAT’ cannot be used on its own.


File: python.info,  Node: shape strides suboffsets,  Next: contiguity requests,  Prev: readonly format,  Up: Buffer request types

7.8.7.5 shape, strides, suboffsets
..................................

The flags that control the logical structure of the memory are listed in
decreasing order of complexity.  Note that each flag contains all bits
of the flags below it.

Request                           shape       strides       suboffsets
                                                            
-----------------------------------------------------------------------------
                                                            
 -- C Macro: PyBUF_INDIRECT       yes         yes           if needed
     ' Parte del                                            
     *note ABI Stabile: 776.
     dalla versione 3.11.'

 -- C Macro: PyBUF_STRIDES        yes         yes           NULL
     ' Parte del                                            
     *note ABI Stabile: 776.
     dalla versione 3.11.'

 -- C Macro: PyBUF_ND             yes         NULL          NULL
     ' Parte del                                            
     *note ABI Stabile: 776.
     dalla versione 3.11.'

 -- C Macro: PyBUF_SIMPLE         NULL        NULL          NULL
     ' Parte del                                            
     *note ABI Stabile: 776.
     dalla versione 3.11.'


File: python.info,  Node: contiguity requests,  Next: compound requests,  Prev: shape strides suboffsets,  Up: Buffer request types

7.8.7.6 contiguity requests
...........................

C or Fortran *note contiguity: 2669. can be explicitly requested, with
and without stride information.  Without stride information, the buffer
must be C-contiguous.

Request                                 shape       strides       suboffsets       contig
                                                                                   
------------------------------------------------------------------------------------------------
                                                                                   
 -- C Macro: PyBUF_C_CONTIGUOUS         yes         yes           NULL             C
     ' Parte del                                                                   
     *note ABI Stabile: 776. dalla
     versione 3.11.'

 -- C Macro: PyBUF_F_CONTIGUOUS         yes         yes           NULL             F
     ' Parte del                                                                   
     *note ABI Stabile: 776. dalla
     versione 3.11.'

 -- C Macro: PyBUF_ANY_CONTIGUOUS       yes         yes           NULL             C or F
     ' Parte del                                                                   
     *note ABI Stabile: 776. dalla
     versione 3.11.'

*note PyBUF_ND: 4f46.                   yes         NULL          NULL             C
                                                                                   


File: python.info,  Node: compound requests,  Prev: contiguity requests,  Up: Buffer request types

7.8.7.7 compound requests
.........................

All possible requests are fully defined by some combination of the flags
in the previous section.  For convenience, the buffer protocol provides
frequently used combinations as single flags.

In the following table 'U' stands for undefined contiguity.  The
consumer would have to call *note PyBuffer_IsContiguous(): 963. to
determine contiguity.

Request                             shape       strides       suboffsets       contig       readonly       format
                                                                                                           
------------------------------------------------------------------------------------------------------------------------
                                                                                                           
 -- C Macro: PyBUF_FULL             yes         yes           if needed        U            0              yes
     ' Parte del                                                                                           
     *note ABI Stabile: 776.
     dalla versione 3.11.'

 -- C Macro: PyBUF_FULL_RO          yes         yes           if needed        U            1 or 0         yes
     ' Parte del                                                                                           
     *note ABI Stabile: 776.
     dalla versione 3.11.'

 -- C Macro: PyBUF_RECORDS          yes         yes           NULL             U            0              yes
     ' Parte del                                                                                           
     *note ABI Stabile: 776.
     dalla versione 3.11.'

 -- C Macro: PyBUF_RECORDS_RO       yes         yes           NULL             U            1 or 0         yes
     ' Parte del                                                                                           
     *note ABI Stabile: 776.
     dalla versione 3.11.'

 -- C Macro: PyBUF_STRIDED          yes         yes           NULL             U            0              NULL
     ' Parte del                                                                                           
     *note ABI Stabile: 776.
     dalla versione 3.11.'

 -- C Macro: PyBUF_STRIDED_RO       yes         yes           NULL             U            1 or 0         NULL
     ' Parte del                                                                                           
     *note ABI Stabile: 776.
     dalla versione 3.11.'

 -- C Macro: PyBUF_CONTIG           yes         NULL          NULL             C            0              NULL
     ' Parte del                                                                                           
     *note ABI Stabile: 776.
     dalla versione 3.11.'

 -- C Macro: PyBUF_CONTIG_RO        yes         NULL          NULL             C            1 or 0         NULL
     ' Parte del                                                                                           
     *note ABI Stabile: 776.
     dalla versione 3.11.'


File: python.info,  Node: Complex arrays,  Next: Buffer-related functions,  Prev: Buffer request types,  Up: Buffer Protocol

7.8.7.8 Complex arrays
......................

* Menu:

* NumPy-style; shape and strides: NumPy-style shape and strides.
* PIL-style; shape, strides and suboffsets: PIL-style shape strides and suboffsets.


File: python.info,  Node: NumPy-style shape and strides,  Next: PIL-style shape strides and suboffsets,  Up: Complex arrays

7.8.7.9 NumPy-style: shape and strides
......................................

The logical structure of NumPy-style arrays is defined by *note
itemsize: 5299, *note ndim: 529c, *note shape: 529b. and *note strides:
5295.

If ‘ndim == 0’, the memory location pointed to by *note buf: 5294. is
interpreted as a scalar of size *note itemsize: 5299.  In that case,
both *note shape: 529b. and *note strides: 5295. are ‘NULL’.

If *note strides: 5295. is ‘NULL’, the array is interpreted as a
standard n-dimensional C-array.  Otherwise, the consumer must access an
n-dimensional array as follows:

     ptr = (char *)buf + indices[0] * strides[0] + ... + indices[n-1] * strides[n-1];
     item = *((typeof(item) *)ptr);

As noted above, *note buf: 5294. can point to any location within the
actual memory block.  An exporter can check the validity of a buffer
with this function:

     def verify_structure(memlen, itemsize, ndim, shape, strides, offset):
         """Verify that the parameters represent a valid array within
            the bounds of the allocated memory:
                char *mem: start of the physical memory block
                memlen: length of the physical memory block
                offset: (char *)buf - mem
         """
         if offset % itemsize:
             return False
         if offset < 0 or offset+itemsize > memlen:
             return False
         if any(v % itemsize for v in strides):
             return False

         if ndim <= 0:
             return ndim == 0 and not shape and not strides
         if 0 in shape:
             return True

         imin = sum(strides[j]*(shape[j]-1) for j in range(ndim)
                    if strides[j] <= 0)
         imax = sum(strides[j]*(shape[j]-1) for j in range(ndim)
                    if strides[j] > 0)

         return 0 <= offset+imin and offset+imax+itemsize <= memlen


File: python.info,  Node: PIL-style shape strides and suboffsets,  Prev: NumPy-style shape and strides,  Up: Complex arrays

7.8.7.10 PIL-style: shape, strides and suboffsets
.................................................

In addition to the regular items, PIL-style arrays can contain pointers
that must be followed in order to get to the next element in a
dimension.  For example, the regular three-dimensional C-array ‘char
v[2][2][3]’ can also be viewed as an array of 2 pointers to 2
two-dimensional arrays: ‘char (*v[2])[2][3]’.  In suboffsets
representation, those two pointers can be embedded at the start of *note
buf: 5294, pointing to two ‘char x[2][3]’ arrays that can be located
anywhere in memory.

Here is a function that returns a pointer to the element in an N-D array
pointed to by an N-dimensional index when there are both non-‘NULL’
strides and suboffsets:

     void *get_item_pointer(int ndim, void *buf, Py_ssize_t *strides,
                            Py_ssize_t *suboffsets, Py_ssize_t *indices) {
         char *pointer = (char*)buf;
         int i;
         for (i = 0; i < ndim; i++) {
             pointer += strides[i] * indices[i];
             if (suboffsets[i] >=0 ) {
                 pointer = *((char**)pointer) + suboffsets[i];
             }
         }
         return (void*)pointer;
     }


File: python.info,  Node: Buffer-related functions,  Prev: Complex arrays,  Up: Buffer Protocol

7.8.7.11 Buffer-related functions
.................................

 -- C Funzione: int PyObject_CheckBuffer (PyObject *obj)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Return
     ‘1’ if 'obj' supports the buffer interface otherwise ‘0’.  When ‘1’
     is returned, it doesn’t guarantee that *note PyObject_GetBuffer():
     63a. will succeed.  This function always succeeds.

 -- C Funzione: int PyObject_GetBuffer (PyObject *exporter, Py_buffer
          *view, int flags)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Send a
     request to 'exporter' to fill in 'view' as specified by 'flags'.
     If the exporter cannot provide a buffer of the exact type, it MUST
     raise *note BufferError: 177f, set ‘view->obj’ to ‘NULL’ and return
     ‘-1’.

     On success, fill in 'view', set ‘view->obj’ to a new reference to
     'exporter' and return 0.  In the case of chained buffer providers
     that redirect requests to a single object, ‘view->obj’ MAY refer to
     this object instead of 'exporter' (See *note Buffer Object
     Structures: 5290.).

     Successful calls to *note PyObject_GetBuffer(): 63a. must be paired
     with calls to *note PyBuffer_Release(): 63b, similar to ‘malloc()’
     and ‘free()’.  Thus, after the consumer is done with the buffer,
     *note PyBuffer_Release(): 63b. must be called exactly once.

 -- C Funzione: void PyBuffer_Release (Py_buffer *view)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Release
     the buffer 'view' and release the *note strong reference: 5e2.
     (i.e.  decrement the reference count) to the view’s supporting
     object, ‘view->obj’.  This function MUST be called when the buffer
     is no longer being used, otherwise reference leaks may occur.

     It is an error to call this function on a buffer that was not
     obtained via *note PyObject_GetBuffer(): 63a.

 -- C Funzione: *note Py_ssize_t: c57. PyBuffer_SizeFromFormat (const
          char *format)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Return
     the implied *note itemsize: 5299. from *note format: 529a.  On
     error, raise an exception and return -1.

     Added in version 3.9.

 -- C Funzione: int PyBuffer_IsContiguous (const Py_buffer *view, char
          order)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Return
     ‘1’ if the memory defined by the 'view' is C-style ('order' is
     ‘'C'’) or Fortran-style ('order' is ‘'F'’) *note contiguous: 2669.
     or either one ('order' is ‘'A'’).  Return ‘0’ otherwise.  This
     function always succeeds.

 -- C Funzione: void *PyBuffer_GetPointer (const Py_buffer *view, const
          Py_ssize_t *indices)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Get the
     memory area pointed to by the 'indices' inside the given 'view'.
     'indices' must point to an array of ‘view->ndim’ indices.

 -- C Funzione: int PyBuffer_FromContiguous (const Py_buffer *view,
          const void *buf, Py_ssize_t len, char fort)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Copy
     contiguous 'len' bytes from 'buf' to 'view'.  'fort' can be ‘'C'’
     or ‘'F'’ (for C-style or Fortran-style ordering).  ‘0’ is returned
     on success, ‘-1’ on error.

 -- C Funzione: int PyBuffer_ToContiguous (void *buf, const Py_buffer
          *src, Py_ssize_t len, char order)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Copy
     'len' bytes from 'src' to its contiguous representation in 'buf'.
     'order' can be ‘'C'’ or ‘'F'’ or ‘'A'’ (for C-style or
     Fortran-style ordering or either one).  ‘0’ is returned on success,
     ‘-1’ on error.

     This function fails if 'len' != 'src->len'.

 -- C Funzione: int PyObject_CopyData (PyObject *dest, PyObject *src)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Copy
     data from 'src' to 'dest' buffer.  Can convert between C-style and
     or Fortran-style buffers.

     ‘0’ is returned on success, ‘-1’ on error.

 -- C Funzione: void PyBuffer_FillContiguousStrides (int ndims,
          Py_ssize_t *shape, Py_ssize_t *strides, int itemsize, char
          order)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Fill the
     'strides' array with byte-strides of a *note contiguous: 2669.
     (C-style if 'order' is ‘'C'’ or Fortran-style if 'order' is ‘'F'’)
     array of the given shape with the given number of bytes per
     element.

 -- C Funzione: int PyBuffer_FillInfo (Py_buffer *view, PyObject
          *exporter, void *buf, Py_ssize_t len, int readonly, int flags)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Handle
     buffer requests for an exporter that wants to expose 'buf' of size
     'len' with writability set according to 'readonly'.  'buf' is
     interpreted as a sequence of unsigned bytes.

     The 'flags' argument indicates the request type.  This function
     always fills in 'view' as specified by flags, unless 'buf' has been
     designated as read-only and *note PyBUF_WRITABLE: 15bd. is set in
     'flags'.

     On success, set ‘view->obj’ to a new reference to 'exporter' and
     return 0.  Otherwise, raise *note BufferError: 177f, set
     ‘view->obj’ to ‘NULL’ and return ‘-1’;

     If this function is used as part of a *note getbufferproc: 5290,
     'exporter' MUST be set to the exporting object and 'flags' must be
     passed unmodified.  Otherwise, 'exporter' MUST be ‘NULL’.


File: python.info,  Node: Concrete Objects Layer,  Next: Initialization Finalization and Threads,  Prev: Abstract Objects Layer,  Up: Python/C API Reference Manual

7.9 Concrete Objects Layer
==========================

The functions in this chapter are specific to certain Python object
types.  Passing them an object of the wrong type is not a good idea; if
you receive an object from a Python program and you are not sure that it
has the right type, you must perform a type check first; for example, to
check that an object is a dictionary, use *note PyDict_Check(): 52ae.
The chapter is structured like the «family tree» of Python object types.

     Avvertimento: While the functions described in this chapter
     carefully check the type of the objects which are passed in, many
     of them do not check for ‘NULL’ being passed instead of a valid
     object.  Allowing ‘NULL’ to be passed in can cause memory access
     violations and immediate termination of the interpreter.

* Menu:

* Fundamental Objects::
* Numeric Objects::
* Sequence Objects::
* Container Objects::
* Function Objects: Function Objects<2>.
* Other Objects::
* C API for extension modules::


File: python.info,  Node: Fundamental Objects,  Next: Numeric Objects,  Up: Concrete Objects Layer

7.9.1 Fundamental Objects
-------------------------

This section describes Python type objects and the singleton object
‘None’.

* Menu:

* Type Objects::
* The None Object::


File: python.info,  Node: Type Objects,  Next: The None Object,  Up: Fundamental Objects

7.9.1.1 Type Objects
....................

 -- C Tipo: type PyTypeObject
     ' Parte del *note API Limitata: 776. (come una struttura opaca).'
     The C structure of the objects used to describe built-in types.

 -- C Variabile: *note PyTypeObject: c9e. PyType_Type
     ' Parte del *note ABI Stabile: 776.'  This is the type object for
     type objects; it is the same object as *note type: f46. in the
     Python layer.

 -- C Funzione: int PyType_Check (PyObject *o)

     Return non-zero if the object 'o' is a type object, including
     instances of types derived from the standard type object.  Return 0
     in all other cases.  This function always succeeds.

 -- C Funzione: int PyType_CheckExact (PyObject *o)

     Return non-zero if the object 'o' is a type object, but not a
     subtype of the standard type object.  Return 0 in all other cases.
     This function always succeeds.

 -- C Funzione: unsigned int PyType_ClearCache ()
     ' Parte del *note ABI Stabile: 776.'  Clear the internal lookup
     cache.  Return the current version tag.

 -- C Funzione: unsigned long PyType_GetFlags (PyTypeObject *type)
     ' Parte del *note ABI Stabile: 776.'  Return the *note tp_flags:
     1c59. member of 'type'.  This function is primarily meant for use
     with ‘Py_LIMITED_API’; the individual flag bits are guaranteed to
     be stable across Python releases, but access to *note tp_flags:
     1c59. itself is not part of the *note limited API: 637.

     Added in version 3.2.

     Cambiato nella versione 3.4: The return type is now ‘unsigned long’
     rather than ‘long’.

 -- C Funzione: *note PyObject: 5df. *PyType_GetDict (PyTypeObject
          *type)

     Return the type object’s internal namespace, which is otherwise
     only exposed via a read-only proxy (*note cls.__dict__: e59.).
     This is a replacement for accessing *note tp_dict: 1a74. directly.
     The returned dictionary must be treated as read-only.

     This function is meant for specific embedding and language-binding
     cases, where direct access to the dict is necessary and indirect
     access (e.g.  via the proxy or *note PyObject_GetAttr(): 5ee.)
     isn’t adequate.

     Extension modules should continue to use ‘tp_dict’, directly or
     indirectly, when setting up their own types.

     Added in version 3.12.

 -- C Funzione: void PyType_Modified (PyTypeObject *type)
     ' Parte del *note ABI Stabile: 776.'  Invalidate the internal
     lookup cache for the type and all of its subtypes.  This function
     must be called after any manual modification of the attributes or
     base classes of the type.

 -- C Funzione: int PyType_AddWatcher (PyType_WatchCallback callback)

     Register 'callback' as a type watcher.  Return a non-negative
     integer ID which must be passed to future calls to *note
     PyType_Watch(): 787.  In case of error (e.g.  no more watcher IDs
     available), return ‘-1’ and set an exception.

     In free-threaded builds, *note PyType_AddWatcher(): 786. is not
     thread-safe, so it must be called at start up (before spawning the
     first thread).

     Added in version 3.12.

 -- C Funzione: int PyType_ClearWatcher (int watcher_id)

     Clear watcher identified by 'watcher_id' (previously returned from
     *note PyType_AddWatcher(): 786.).  Return ‘0’ on success, ‘-1’ on
     error (e.g.  if 'watcher_id' was never registered.)

     An extension should never call ‘PyType_ClearWatcher’ with a
     'watcher_id' that was not returned to it by a previous call to
     *note PyType_AddWatcher(): 786.

     Added in version 3.12.

 -- C Funzione: int PyType_Watch (int watcher_id, PyObject *type)

     Mark 'type' as watched.  The callback granted 'watcher_id' by *note
     PyType_AddWatcher(): 786. will be called whenever *note
     PyType_Modified(): 1b63. reports a change to 'type'.  (The callback
     may be called only once for a series of consecutive modifications
     to 'type', if ‘_PyType_Lookup()’ is not called on 'type' between
     the modifications; this is an implementation detail and subject to
     change.)

     An extension should never call ‘PyType_Watch’ with a 'watcher_id'
     that was not returned to it by a previous call to *note
     PyType_AddWatcher(): 786.

     Added in version 3.12.

 -- C Funzione: int PyType_Unwatch (int watcher_id, PyObject *type)

     Mark 'type' as not watched.  This undoes a previous call to *note
     PyType_Watch(): 787.  'type' must not be ‘NULL’.

     An extension should never call this function with a 'watcher_id'
     that was not returned to it by a previous call to *note
     PyType_AddWatcher(): 786.

     On success, this function returns ‘0’.  On failure, this function
     returns ‘-1’ with an exception set.

     Added in version 3.12.

 -- C Tipo: typedef int (*PyType_WatchCallback)(*note PyObject: 5df.
          *type)

     Type of a type-watcher callback function.

     The callback must not modify 'type' or cause *note
     PyType_Modified(): 1b63. to be called on 'type' or any type in its
     MRO; violating this rule could cause infinite recursion.

     Added in version 3.12.

 -- C Funzione: int PyType_HasFeature (PyTypeObject *o, int feature)

     Return non-zero if the type object 'o' sets the feature 'feature'.
     Type features are denoted by single bit flags.

 -- C Funzione: int PyType_FastSubclass (PyTypeObject *type, int flag)

     Return non-zero if the type object 'type' sets the subclass flag
     'flag'.  Subclass flags are denoted by *note Py_TPFLAGS_*_SUBCLASS:
     52b8.  This function is used by many ‘_Check’ functions for common
     types.

     Vedi anche
     ..........

     *note PyObject_TypeCheck(): 1c9d, which is used as a slower
     alternative in ‘_Check’ functions for types that don’t come with
     subclass flags.

 -- C Funzione: int PyType_IS_GC (PyTypeObject *o)

     Return true if the type object includes support for the cycle
     detector; this tests the type flag *note Py_TPFLAGS_HAVE_GC: 982.

 -- C Funzione: int PyType_IsSubtype (PyTypeObject *a, PyTypeObject *b)
     ' Parte del *note ABI Stabile: 776.'  Return true if 'a' is a
     subtype of 'b'.

     This function only checks for actual subtypes, which means that
     *note __subclasscheck__(): 23ad. is not called on 'b'.  Call *note
     PyObject_IsSubclass(): 10a9. to do the same check that *note
     issubclass(): 9c6. would do.

 -- C Funzione: *note PyObject: 5df. *PyType_GenericAlloc (PyTypeObject
          *type, Py_ssize_t nitems)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Generic handler for the *note tp_alloc: 4eb9. slot
     of a type object.  Uses Python’s default memory allocation
     mechanism to allocate memory for a new instance, zeros the memory,
     then initializes the memory as if by calling *note PyObject_Init():
     c62. or *note PyObject_InitVar(): 1d28.

     Do not call this directly to allocate memory for an object; call
     the type’s *note tp_alloc: 4eb9. slot instead.

     For types that support garbage collection (i.e., the *note
     Py_TPFLAGS_HAVE_GC: 982. flag is set), this function behaves like
     *note PyObject_GC_New: c9b. or *note PyObject_GC_NewVar: c9c.
     (except the memory is guaranteed to be zeroed before
     initialization), and should be paired with *note PyObject_GC_Del():
     170a. in *note tp_free: 4eb8.  Otherwise, it behaves like *note
     PyObject_New: b7e. or *note PyObject_NewVar: b7f. (except the
     memory is guaranteed to be zeroed before initialization) and should
     be paired with *note PyObject_Free(): e61. in *note tp_free: 4eb8.

 -- C Funzione: *note PyObject: 5df. *PyType_GenericNew (PyTypeObject
          *type, PyObject *args, PyObject *kwds)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Generic handler for the *note tp_new: 7a0. slot of
     a type object.  Creates a new instance using the type’s *note
     tp_alloc: 4eb9. slot and returns the resulting object.

 -- C Funzione: int PyType_Ready (PyTypeObject *type)
     ' Parte del *note ABI Stabile: 776.'  Finalize a type object.  This
     should be called on all type objects to finish their
     initialization.  This function is responsible for adding inherited
     slots from a type’s base class.  Return ‘0’ on success, or return
     ‘-1’ and sets an exception on error.

          Nota: If some of the base classes implements the GC protocol
          and the provided type does not include the *note
          Py_TPFLAGS_HAVE_GC: 982. in its flags, then the GC protocol
          will be automatically implemented from its parents.  On the
          contrary, if the type being created does include *note
          Py_TPFLAGS_HAVE_GC: 982. in its flags then it 'must' implement
          the GC protocol itself by at least implementing the *note
          tp_traverse: 983. handle.

 -- C Funzione: *note PyObject: 5df. *PyType_GetName (PyTypeObject
          *type)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.11.'  Return the type’s name.
     Equivalent to getting the type’s *note __name__: 16b2. attribute.

     Added in version 3.11.

 -- C Funzione: *note PyObject: 5df. *PyType_GetQualName (PyTypeObject
          *type)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.11.'  Return the type’s qualified
     name.  Equivalent to getting the type’s *note __qualname__: 235a.
     attribute.

     Added in version 3.11.

 -- C Funzione: *note PyObject: 5df. *PyType_GetFullyQualifiedName
          (PyTypeObject *type)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Return
     the type’s fully qualified name.  Equivalent to
     ‘f"{type.__module__}.{type.__qualname__}"’, or *note
     type.__qualname__: 235a. if *note type.__module__: 617. is not a
     string or is equal to ‘"builtins"’.

     Added in version 3.13.

 -- C Funzione: *note PyObject: 5df. *PyType_GetModuleName (PyTypeObject
          *type)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Return
     the type’s module name.  Equivalent to getting the *note
     type.__module__: 617. attribute.

     Added in version 3.13.

 -- C Funzione: void *PyType_GetSlot (PyTypeObject *type, int slot)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.4.'  Return
     the function pointer stored in the given slot.  If the result is
     ‘NULL’, this indicates that either the slot is ‘NULL’, or that the
     function was called with invalid parameters.  Callers will
     typically cast the result pointer into the appropriate function
     type.

     See *note PyType_Slot.slot: 52ba. for possible values of the 'slot'
     argument.

     Added in version 3.4.

     Cambiato nella versione 3.10: *note PyType_GetSlot(): a9e. can now
     accept all types.  Previously, it was limited to *note heap types:
     b60.

 -- C Funzione: *note PyObject: 5df. *PyType_GetModule (PyTypeObject
          *type)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Return
     the module object associated with the given type when the type was
     created using *note PyType_FromModuleAndSpec(): 774.

     If no module is associated with the given type, sets *note
     TypeError: 198. and returns ‘NULL’.

     This function is usually used to get the module in which a method
     is defined.  Note that in such a method,
     ‘PyType_GetModule(Py_TYPE(self))’ may not return the intended
     result.  ‘Py_TYPE(self)’ may be a 'subclass' of the intended class,
     and subclasses are not necessarily defined in the same module as
     their superclass.  See *note PyCMethod: 969. to get the class that
     defines the method.  See *note PyType_GetModuleByDef(): 635. for
     cases when ‘PyCMethod’ cannot be used.

     Added in version 3.9.

 -- C Funzione: void *PyType_GetModuleState (PyTypeObject *type)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Return
     the state of the module object associated with the given type.
     This is a shortcut for calling *note PyModule_GetState(): b79. on
     the result of *note PyType_GetModule(): b68.

     If no module is associated with the given type, sets *note
     TypeError: 198. and returns ‘NULL’.

     If the 'type' has an associated module but its state is ‘NULL’,
     returns ‘NULL’ without setting an exception.

     Added in version 3.9.

 -- C Funzione: *note PyObject: 5df. *PyType_GetModuleByDef
          (PyTypeObject *type, struct PyModuleDef *def)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776. dalla versione 3.13.'  Find the first
     superclass whose module was created from the given *note
     PyModuleDef: b76. 'def', and return that module.

     If no module is found, raises a *note TypeError: 198. and returns
     ‘NULL’.

     This function is intended to be used together with *note
     PyModule_GetState(): b79. to get module state from slot methods
     (such as *note tp_init: 7a2. or *note nb_add: 52bb.) and other
     places where a method’s defining class cannot be passed using the
     *note PyCMethod: 969. calling convention.

     The returned reference is *note borrowed: 3d7. from 'type', and
     will be valid as long as you hold a reference to 'type'.  Do not
     release it with *note Py_DECREF(): 791. or similar.

     Added in version 3.11.

 -- C Funzione: int PyType_GetBaseByToken (PyTypeObject *type, void
          *token, PyTypeObject **result)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Find the
     first superclass in 'type'’s *note method resolution order: 25bd.
     whose *note Py_tp_token: 3b1. token is equal to the given one.

        * If found, set '*result' to a new *note strong reference: 5e2.
          to it and return ‘1’.

        * If not found, set '*result' to ‘NULL’ and return ‘0’.

        * On error, set '*result' to ‘NULL’ and return ‘-1’ with an
          exception set.

     The 'result' argument may be ‘NULL’, in which case '*result' is not
     set.  Use this if you need only the return value.

     The 'token' argument may not be ‘NULL’.

     Added in version 3.14.

 -- C Funzione: int PyUnstable_Type_AssignVersionTag (PyTypeObject
          *type)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Attempt to assign a version tag to the given type.

     Returns 1 if the type already had a valid version tag or a new one
     was assigned, or 0 if a new tag could not be assigned.

     Added in version 3.12.

 -- C Funzione: int PyType_SUPPORTS_WEAKREFS (PyTypeObject *type)

     Return true if instances of 'type' support creating weak
     references, false otherwise.  This function always succeeds.
     'type' must not be ‘NULL’.

     Vedi anche
     ..........

        * *note Weak Reference Objects: 5267.

        * *note weakref: 11a.

* Menu:

* Creating Heap-Allocated Types::


File: python.info,  Node: Creating Heap-Allocated Types,  Up: Type Objects

7.9.1.2 Creating Heap-Allocated Types
.....................................

The following functions and structs are used to create *note heap types:
b60.

 -- C Funzione: *note PyObject: 5df. *PyType_FromMetaclass (PyTypeObject
          *metaclass, PyObject *module, PyType_Spec *spec, PyObject
          *bases)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Create
     and return a *note heap type: b60. from the 'spec' (see *note
     Py_TPFLAGS_HEAPTYPE: aae.).

     The metaclass 'metaclass' is used to construct the resulting type
     object.  When 'metaclass' is ‘NULL’, the metaclass is derived from
     'bases' (or 'Py_tp_base[s]' slots if 'bases' is ‘NULL’, see below).

     Metaclasses that override *note tp_new: 7a0. are not supported,
     except if ‘tp_new’ is ‘NULL’.

     The 'bases' argument can be used to specify base classes; it can
     either be only one class or a tuple of classes.  If 'bases' is
     ‘NULL’, the *note Py_tp_bases: 515b. slot is used instead.  If that
     also is ‘NULL’, the *note Py_tp_base: 515a. slot is used instead.
     If that also is ‘NULL’, the new type derives from *note object:
     c80.

     The 'module' argument can be used to record the module in which the
     new class is defined.  It must be a module object or ‘NULL’.  If
     not ‘NULL’, the module is associated with the new type and can
     later be retrieved with *note PyType_GetModule(): b68.  The
     associated module is not inherited by subclasses; it must be
     specified for each class individually.

     This function calls *note PyType_Ready(): 981. on the new type.

     Note that this function does 'not' fully match the behavior of
     calling *note type(): f46. or using the *note class: 14df.
     statement.  With user-provided base types or metaclasses, prefer
     *note calling: 526c. *note type: f46. (or the metaclass) over
     ‘PyType_From*’ functions.  Specifically:

        * *note __new__(): 7a1. is not called on the new class (and it
          must be set to ‘type.__new__’).

        * *note __init__(): 8c0. is not called on the new class.

        * *note __init_subclass__(): 844. is not called on any bases.

        * *note __set_name__(): e4a. is not called on new descriptors.

     Added in version 3.12.

 -- C Funzione: *note PyObject: 5df. *PyType_FromModuleAndSpec (PyObject
          *module, PyType_Spec *spec, PyObject *bases)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.10.'  Equivalent to
     ‘PyType_FromMetaclass(NULL, module, spec, bases)’.

     Added in version 3.9.

     Cambiato nella versione 3.10: The function now accepts a single
     class as the 'bases' argument and ‘NULL’ as the ‘tp_doc’ slot.

     Cambiato nella versione 3.12: The function now finds and uses a
     metaclass corresponding to the provided base classes.  Previously,
     only *note type: f46. instances were returned.

     The *note tp_new: 7a0. of the metaclass is 'ignored'.  which may
     result in incomplete initialization.  Creating classes whose
     metaclass overrides *note tp_new: 7a0. is deprecated.

     Cambiato nella versione 3.14: Creating classes whose metaclass
     overrides *note tp_new: 7a0. is no longer allowed.

 -- C Funzione: *note PyObject: 5df. *PyType_FromSpecWithBases
          (PyType_Spec *spec, PyObject *bases)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.3.'  Equivalent to
     ‘PyType_FromMetaclass(NULL, NULL, spec, bases)’.

     Added in version 3.3.

     Cambiato nella versione 3.12: The function now finds and uses a
     metaclass corresponding to the provided base classes.  Previously,
     only *note type: f46. instances were returned.

     The *note tp_new: 7a0. of the metaclass is 'ignored'.  which may
     result in incomplete initialization.  Creating classes whose
     metaclass overrides *note tp_new: 7a0. is deprecated.

     Cambiato nella versione 3.14: Creating classes whose metaclass
     overrides *note tp_new: 7a0. is no longer allowed.

 -- C Funzione: *note PyObject: 5df. *PyType_FromSpec (PyType_Spec
          *spec)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Equivalent to ‘PyType_FromMetaclass(NULL, NULL,
     spec, NULL)’.

     Cambiato nella versione 3.12: The function now finds and uses a
     metaclass corresponding to the base classes provided in
     'Py_tp_base[s]' slots.  Previously, only *note type: f46. instances
     were returned.

     The *note tp_new: 7a0. of the metaclass is 'ignored'.  which may
     result in incomplete initialization.  Creating classes whose
     metaclass overrides *note tp_new: 7a0. is deprecated.

     Cambiato nella versione 3.14: Creating classes whose metaclass
     overrides *note tp_new: 7a0. is no longer allowed.

 -- C Funzione: int PyType_Freeze (PyTypeObject *type)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Make a
     type immutable: set the *note Py_TPFLAGS_IMMUTABLETYPE: 3cf. flag.

     All base classes of 'type' must be immutable.

     On success, return ‘0’.  On error, set an exception and return
     ‘-1’.

     The type must not be used before it’s made immutable.  For example,
     type instances must not be created before the type is made
     immutable.

     Added in version 3.14.

 -- C Tipo: type PyType_Spec
     ' Parte del *note ABI Stabile: 776. (inclusi tutti i membri).'
     Structure defining a type’s behavior.

      -- C Membro: const char *name

          Name of the type, used to set *note PyTypeObject.tp_name:
          1c98.

      -- C Membro: int basicsize

          If positive, specifies the size of the instance in bytes.  It
          is used to set *note PyTypeObject.tp_basicsize: b80.

          If zero, specifies that *note tp_basicsize: b80. should be
          inherited.

          If negative, the absolute value specifies how much space
          instances of the class need 'in addition' to the superclass.
          Use *note PyObject_GetTypeData(): 76c. to get a pointer to
          subclass-specific memory reserved this way.  For negative
          ‘basicsize’, Python will insert padding when needed to meet
          *note tp_basicsize: b80.’s alignment requirements.

          Cambiato nella versione 3.12: Previously, this field could not
          be negative.

      -- C Membro: int itemsize

          Size of one element of a variable-size type, in bytes.  Used
          to set *note PyTypeObject.tp_itemsize: 23a1.  See
          ‘tp_itemsize’ documentation for caveats.

          If zero, *note tp_itemsize: 23a1. is inherited.  Extending
          arbitrary variable-sized classes is dangerous, since some
          types use a fixed offset for variable-sized memory, which can
          then overlap fixed-sized memory used by a subclass.  To help
          prevent mistakes, inheriting ‘itemsize’ is only possible in
          the following situations:

             - The base is not variable-sized (its *note tp_itemsize:
               23a1.).

             - The requested *note PyType_Spec.basicsize: 76b. is
               positive, suggesting that the memory layout of the base
               class is known.

             - The requested *note PyType_Spec.basicsize: 76b. is zero,
               suggesting that the subclass does not access the
               instance’s memory directly.

             - With the *note Py_TPFLAGS_ITEMS_AT_END: 76e. flag.

      -- C Membro: unsigned int flags

          Type flags, used to set *note PyTypeObject.tp_flags: 1c59.

          If the ‘Py_TPFLAGS_HEAPTYPE’ flag is not set, *note
          PyType_FromSpecWithBases(): 79f. sets it automatically.

      -- C Membro: *note PyType_Slot: 50b4. *slots

          Array of *note PyType_Slot: 50b4. structures.  Terminated by
          the special slot value ‘{0, NULL}’.

          Each slot ID should be specified at most once.

 -- C Tipo: type PyType_Slot
     ' Parte del *note ABI Stabile: 776. (inclusi tutti i membri).'
     Structure defining optional functionality of a type, containing a
     slot ID and a value pointer.

      -- C Membro: int slot

          A slot ID.

          Slot IDs are named like the field names of the structures
          *note PyTypeObject: c9e, *note PyNumberMethods: 1625, *note
          PySequenceMethods: 4edd, *note PyMappingMethods: 4ede. and
          *note PyAsyncMethods: 52c3. with an added ‘Py_’ prefix.  For
          example, use:

             * *note Py_tp_dealloc: 515e. to set *note
               PyTypeObject.tp_dealloc: 4ea5.

             * *note Py_nb_add: 512f. to set *note
               PyNumberMethods.nb_add: 52bb.

             * *note Py_sq_length: 5157. to set *note
               PySequenceMethods.sq_length: 52c4.

          An additional slot is supported that does not correspond to a
          ‘PyTypeObject’ struct field:

             * *note Py_tp_token: 3b1.

          The following “offset” fields cannot be set using *note
          PyType_Slot: 50b4.:

             * *note tp_weaklistoffset: b81. (use *note
               Py_TPFLAGS_MANAGED_WEAKREF: 77d. instead if possible)

             * *note tp_dictoffset: 52c5. (use *note
               Py_TPFLAGS_MANAGED_DICT: 60f. instead if possible)

             * *note tp_vectorcall_offset: 526e. (use
               ‘"__vectorcalloffset__"’ in *note PyMemberDef: 52c6.)

          If it is not possible to switch to a ‘MANAGED’ flag (for
          example, for vectorcall or to support Python older than 3.12),
          specify the offset in *note Py_tp_members: 516d.  See *note
          PyMemberDef documentation: 52c6. for details.

          The following internal fields cannot be set at all when
          creating a heap type:

             * *note tp_dict: 1a74, *note tp_mro: 52c7, *note tp_cache:
               52c8, *note tp_subclasses: 793, and *note tp_weaklist:
               52c9.

          Setting *note Py_tp_bases: 515b. or *note Py_tp_base: 515a.
          may be problematic on some platforms.  To avoid issues, use
          the 'bases' argument of *note PyType_FromSpecWithBases(): 79f.
          instead.

          Cambiato nella versione 3.9: Slots in *note PyBufferProcs:
          52ca. may be set in the unlimited API.

          Cambiato nella versione 3.11: *note bf_getbuffer: 967. and
          *note bf_releasebuffer: 968. are now available under the *note
          limited API: 637.

          Cambiato nella versione 3.14: The field *note tp_vectorcall:
          1972. can now be set using *note Py_tp_vectorcall: 5176.  See
          the field’s documentation for details.

      -- C Membro: void *pfunc

          The desired value of the slot.  In most cases, this is a
          pointer to a function.

          'pfunc' values may not be ‘NULL’, except for the following
          slots:

             * *note Py_tp_doc: 5162.

             * *note Py_tp_token: 3b1. (for clarity, prefer *note
               Py_TP_USE_SPEC: 5111. rather than ‘NULL’)

 -- C Macro: Py_tp_token
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  A *note
     slot: 52ba. that records a static memory layout ID for a class.

     If the *note PyType_Spec: 1a71. of the class is statically
     allocated, the token can be set to the spec using the special value
     *note Py_TP_USE_SPEC: 5111.:

          static PyType_Slot foo_slots[] = {
             {Py_tp_token, Py_TP_USE_SPEC},

     It can also be set to an arbitrary pointer, but you must ensure
     that:

        * The pointer outlives the class, so it’s not reused for
          something else while the class exists.

        * It «belongs» to the extension module where the class lives, so
          it will not clash with other extensions.

     Use *note PyType_GetBaseByToken(): 3b0. to check if a class’s
     superclass has a given token – that is, check whether the memory
     layout is compatible.

     To get the token for a given class (without considering
     superclasses), use *note PyType_GetSlot(): a9e. with ‘Py_tp_token’.

     Added in version 3.14.

      -- C Macro: Py_TP_USE_SPEC
          ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'
          Used as a value with *note Py_tp_token: 3b1. to set the token
          to the class’s *note PyType_Spec: 1a71.  Expands to ‘NULL’.

          Added in version 3.14.


File: python.info,  Node: The None Object,  Prev: Type Objects,  Up: Fundamental Objects

7.9.1.3 The ‘None’ Object
.........................

Note that the *note PyTypeObject: c9e. for ‘None’ is not directly
exposed in the Python/C API. Since ‘None’ is a singleton, testing for
object identity (using ‘==’ in C) is sufficient.  There is no
‘PyNone_Check()’ function for the same reason.

 -- C Variabile: *note PyObject: 5df. *Py_None

     The Python ‘None’ object, denoting lack of value.  This object has
     no methods and is *note immortal: 290.

     Cambiato nella versione 3.12: *note Py_None: 4e88. is *note
     immortal: 290.

 -- C Macro: Py_RETURN_NONE

     Return *note Py_None: 4e88. from a function.


File: python.info,  Node: Numeric Objects,  Next: Sequence Objects,  Prev: Fundamental Objects,  Up: Concrete Objects Layer

7.9.2 Numeric Objects
---------------------

* Menu:

* Integer Objects::
* Boolean Objects::
* Floating-Point Objects::
* Complex Number Objects::


File: python.info,  Node: Integer Objects,  Next: Boolean Objects,  Up: Numeric Objects

7.9.2.1 Integer Objects
.......................

All integers are implemented as «long» integer objects of arbitrary
size.

On error, most ‘PyLong_As*’ APIs return ‘(return type)-1’ which cannot
be distinguished from a number.  Use *note PyErr_Occurred(): 1c97. to
disambiguate.

 -- C Tipo: type PyLongObject
     ' Parte del *note API Limitata: 776. (come una struttura opaca).'
     This subtype of *note PyObject: 5df. represents a Python integer
     object.

 -- C Variabile: *note PyTypeObject: c9e. PyLong_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python integer type.  This is the
     same object as *note int: 19b. in the Python layer.

 -- C Funzione: int PyLong_Check (PyObject *p)

     Return true if its argument is a *note PyLongObject: 39e. or a
     subtype of *note PyLongObject: 39e.  This function always succeeds.

 -- C Funzione: int PyLong_CheckExact (PyObject *p)

     Return true if its argument is a *note PyLongObject: 39e, but not a
     subtype of *note PyLongObject: 39e.  This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromLong (long v)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new *note PyLongObject: 39e. object from
     'v', or ‘NULL’ on failure.

     'Dettaglio dell’implementazione di CPython:' CPython keeps an array
     of integer objects for all integers between ‘-5’ and ‘256’.  When
     you create an int in that range you actually just get back a
     reference to the existing object.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromUnsignedLong (unsigned
          long v)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new *note PyLongObject: 39e. object from a
     C unsigned long, or ‘NULL’ on failure.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromSsize_t (Py_ssize_t v)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new *note PyLongObject: 39e. object from a
     C *note Py_ssize_t: c57, or ‘NULL’ on failure.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromSize_t (size_t v)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new *note PyLongObject: 39e. object from a
     C ‘size_t’, or ‘NULL’ on failure.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromLongLong (long long v)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new *note PyLongObject: 39e. object from a
     C long long, or ‘NULL’ on failure.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromInt32 (int32_t value)
 -- C Funzione: *note PyObject: 5df. *PyLong_FromInt64 (int64_t value)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Return a
     new *note PyLongObject: 39e. object from a signed C int32_t or
     int64_t, or ‘NULL’ with an exception set on failure.

     Added in version 3.14.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromUnsignedLongLong
          (unsigned long long v)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new *note PyLongObject: 39e. object from a
     C unsigned long long, or ‘NULL’ on failure.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromUInt32 (uint32_t value)
 -- C Funzione: *note PyObject: 5df. *PyLong_FromUInt64 (uint64_t value)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Return a
     new *note PyLongObject: 39e. object from an unsigned C uint32_t or
     uint64_t, or ‘NULL’ with an exception set on failure.

     Added in version 3.14.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromDouble (double v)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new *note PyLongObject: 39e. object from
     the integer part of 'v', or ‘NULL’ on failure.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromString (const char
          *str, char **pend, int base)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new *note PyLongObject: 39e. based on the
     string value in 'str', which is interpreted according to the radix
     in 'base', or ‘NULL’ on failure.  If 'pend' is non-‘NULL’, '*pend'
     will point to the end of 'str' on success or to the first character
     that could not be processed on error.  If 'base' is ‘0’, 'str' is
     interpreted using the *note Integer literals: 22f4. definition; in
     this case, leading zeros in a non-zero decimal number raises a
     *note ValueError: 2ec.  If 'base' is not ‘0’, it must be between
     ‘2’ and ‘36’, inclusive.  Leading and trailing whitespace and
     single underscores after a base specifier and between digits are
     ignored.  If there are no digits or 'str' is not NULL-terminated
     following the digits and trailing whitespace, *note ValueError:
     2ec. will be raised.

     Vedi anche
     ..........

     *note PyLong_AsNativeBytes(): 606. and *note
     PyLong_FromNativeBytes(): 607. functions can be used to convert a
     *note PyLongObject: 39e. to/from an array of bytes in base ‘256’.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromUnicodeObject (PyObject
          *u, int base)
     'Valore di ritorno: Nuovo riferimento.'  Convert a sequence of
     Unicode digits in the string 'u' to a Python integer value.

     Added in version 3.3.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromVoidPtr (void *p)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Python integer from the pointer 'p'.  The
     pointer value can be retrieved from the resulting value using *note
     PyLong_AsVoidPtr(): 5023.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromNativeBytes (const void
          *buffer, size_t n_bytes, int flags)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Create a
     Python integer from the value contained in the first 'n_bytes' of
     'buffer', interpreted as a two’s-complement signed number.

     'flags' are as for *note PyLong_AsNativeBytes(): 606.  Passing ‘-1’
     will select the native endian that CPython was compiled with and
     assume that the most-significant bit is a sign bit.  Passing
     ‘Py_ASNATIVEBYTES_UNSIGNED_BUFFER’ will produce the same result as
     calling *note PyLong_FromUnsignedNativeBytes(): 608.  Other flags
     are ignored.

     Added in version 3.13.

 -- C Funzione: *note PyObject: 5df. *PyLong_FromUnsignedNativeBytes
          (const void *buffer, size_t n_bytes, int flags)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Create a
     Python integer from the value contained in the first 'n_bytes' of
     'buffer', interpreted as an unsigned number.

     'flags' are as for *note PyLong_AsNativeBytes(): 606.  Passing ‘-1’
     will select the native endian that CPython was compiled with and
     assume that the most-significant bit is not a sign bit.  Flags
     other than endian are ignored.

     Added in version 3.13.

 -- C Macro: PyLong_FromPid (pid)

     Macro for creating a Python integer from a process identifier.

     This can be defined as an alias to *note PyLong_FromLong(): 1bb8.
     or *note PyLong_FromLongLong(): 1bb9, depending on the size of the
     system’s PID type.

     Added in version 3.2.

 -- C Funzione: long PyLong_AsLong (PyObject *obj)
     ' Parte del *note ABI Stabile: 776.'

     Return a C long representation of 'obj'.  If 'obj' is not an
     instance of *note PyLongObject: 39e, first call its *note
     __index__(): 19e. method (if present) to convert it to a *note
     PyLongObject: 39e.

     Raise *note OverflowError: a83. if the value of 'obj' is out of
     range for a long.

     Returns ‘-1’ on error.  Use *note PyErr_Occurred(): 1c97. to
     disambiguate.

     Cambiato nella versione 3.8: Use *note __index__(): 19e. if
     available.

     Cambiato nella versione 3.10: This function will no longer use
     *note __int__(): 19d.

      -- C Funzione: long PyLong_AS_LONG (PyObject *obj)

          A *note soft deprecated: 23d. alias.  Exactly equivalent to
          the preferred ‘PyLong_AsLong’.  In particular, it can fail
          with *note OverflowError: a83. or another exception.

          Deprecato dalla versione 3.14: The function is soft
          deprecated.

 -- C Funzione: int PyLong_AsInt (PyObject *obj)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Similar
     to *note PyLong_AsLong(): 605, but store the result in a C int
     instead of a C long.

     Added in version 3.13.

 -- C Funzione: long PyLong_AsLongAndOverflow (PyObject *obj, int
          *overflow)
     ' Parte del *note ABI Stabile: 776.'  Return a C long
     representation of 'obj'.  If 'obj' is not an instance of *note
     PyLongObject: 39e, first call its *note __index__(): 19e. method
     (if present) to convert it to a *note PyLongObject: 39e.

     If the value of 'obj' is greater than ‘LONG_MAX’ or less than
     ‘LONG_MIN’, set '*overflow' to ‘1’ or ‘-1’, respectively, and
     return ‘-1’; otherwise, set '*overflow' to ‘0’.  If any other
     exception occurs set '*overflow' to ‘0’ and return ‘-1’ as usual.

     Returns ‘-1’ on error.  Use *note PyErr_Occurred(): 1c97. to
     disambiguate.

     Cambiato nella versione 3.8: Use *note __index__(): 19e. if
     available.

     Cambiato nella versione 3.10: This function will no longer use
     *note __int__(): 19d.

 -- C Funzione: long long PyLong_AsLongLong (PyObject *obj)
     ' Parte del *note ABI Stabile: 776.'

     Return a C long long representation of 'obj'.  If 'obj' is not an
     instance of *note PyLongObject: 39e, first call its *note
     __index__(): 19e. method (if present) to convert it to a *note
     PyLongObject: 39e.

     Raise *note OverflowError: a83. if the value of 'obj' is out of
     range for a long long.

     Returns ‘-1’ on error.  Use *note PyErr_Occurred(): 1c97. to
     disambiguate.

     Cambiato nella versione 3.8: Use *note __index__(): 19e. if
     available.

     Cambiato nella versione 3.10: This function will no longer use
     *note __int__(): 19d.

 -- C Funzione: long long PyLong_AsLongLongAndOverflow (PyObject *obj,
          int *overflow)
     ' Parte del *note ABI Stabile: 776.'  Return a C long long
     representation of 'obj'.  If 'obj' is not an instance of *note
     PyLongObject: 39e, first call its *note __index__(): 19e. method
     (if present) to convert it to a *note PyLongObject: 39e.

     If the value of 'obj' is greater than ‘LLONG_MAX’ or less than
     ‘LLONG_MIN’, set '*overflow' to ‘1’ or ‘-1’, respectively, and
     return ‘-1’; otherwise, set '*overflow' to ‘0’.  If any other
     exception occurs set '*overflow' to ‘0’ and return ‘-1’ as usual.

     Returns ‘-1’ on error.  Use *note PyErr_Occurred(): 1c97. to
     disambiguate.

     Added in version 3.2.

     Cambiato nella versione 3.8: Use *note __index__(): 19e. if
     available.

     Cambiato nella versione 3.10: This function will no longer use
     *note __int__(): 19d.

 -- C Funzione: *note Py_ssize_t: c57. PyLong_AsSsize_t (PyObject
          *pylong)
     ' Parte del *note ABI Stabile: 776.'

     Return a C *note Py_ssize_t: c57. representation of 'pylong'.
     'pylong' must be an instance of *note PyLongObject: 39e.

     Raise *note OverflowError: a83. if the value of 'pylong' is out of
     range for a *note Py_ssize_t: c57.

     Returns ‘-1’ on error.  Use *note PyErr_Occurred(): 1c97. to
     disambiguate.

 -- C Funzione: unsigned long PyLong_AsUnsignedLong (PyObject *pylong)
     ' Parte del *note ABI Stabile: 776.'

     Return a C unsigned long representation of 'pylong'.  'pylong' must
     be an instance of *note PyLongObject: 39e.

     Raise *note OverflowError: a83. if the value of 'pylong' is out of
     range for a unsigned long.

     Returns ‘(unsigned long)-1’ on error.  Use *note PyErr_Occurred():
     1c97. to disambiguate.

 -- C Funzione: size_t PyLong_AsSize_t (PyObject *pylong)
     ' Parte del *note ABI Stabile: 776.'

     Return a C ‘size_t’ representation of 'pylong'.  'pylong' must be
     an instance of *note PyLongObject: 39e.

     Raise *note OverflowError: a83. if the value of 'pylong' is out of
     range for a ‘size_t’.

     Returns ‘(size_t)-1’ on error.  Use *note PyErr_Occurred(): 1c97.
     to disambiguate.

 -- C Funzione: unsigned long long PyLong_AsUnsignedLongLong (PyObject
          *pylong)
     ' Parte del *note ABI Stabile: 776.'

     Return a C unsigned long long representation of 'pylong'.  'pylong'
     must be an instance of *note PyLongObject: 39e.

     Raise *note OverflowError: a83. if the value of 'pylong' is out of
     range for an unsigned long long.

     Returns ‘(unsigned long long)-1’ on error.  Use *note
     PyErr_Occurred(): 1c97. to disambiguate.

     Cambiato nella versione 3.1: A negative 'pylong' now raises *note
     OverflowError: a83, not *note TypeError: 198.

 -- C Funzione: unsigned long PyLong_AsUnsignedLongMask (PyObject *obj)
     ' Parte del *note ABI Stabile: 776.'  Return a C unsigned long
     representation of 'obj'.  If 'obj' is not an instance of *note
     PyLongObject: 39e, first call its *note __index__(): 19e. method
     (if present) to convert it to a *note PyLongObject: 39e.

     If the value of 'obj' is out of range for an unsigned long, return
     the reduction of that value modulo ‘ULONG_MAX + 1’.

     Returns ‘(unsigned long)-1’ on error.  Use *note PyErr_Occurred():
     1c97. to disambiguate.

     Cambiato nella versione 3.8: Use *note __index__(): 19e. if
     available.

     Cambiato nella versione 3.10: This function will no longer use
     *note __int__(): 19d.

 -- C Funzione: unsigned long long PyLong_AsUnsignedLongLongMask
          (PyObject *obj)
     ' Parte del *note ABI Stabile: 776.'  Return a C unsigned long long
     representation of 'obj'.  If 'obj' is not an instance of *note
     PyLongObject: 39e, first call its *note __index__(): 19e. method
     (if present) to convert it to a *note PyLongObject: 39e.

     If the value of 'obj' is out of range for an unsigned long long,
     return the reduction of that value modulo ‘ULLONG_MAX + 1’.

     Returns ‘(unsigned long long)-1’ on error.  Use *note
     PyErr_Occurred(): 1c97. to disambiguate.

     Cambiato nella versione 3.8: Use *note __index__(): 19e. if
     available.

     Cambiato nella versione 3.10: This function will no longer use
     *note __int__(): 19d.

 -- C Funzione: int PyLong_AsInt32 (PyObject *obj, int32_t *value)
 -- C Funzione: int PyLong_AsInt64 (PyObject *obj, int64_t *value)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Set
     '*value' to a signed C int32_t or int64_t representation of 'obj'.

     If 'obj' is not an instance of *note PyLongObject: 39e, first call
     its *note __index__(): 19e. method (if present) to convert it to a
     *note PyLongObject: 39e.

     If the 'obj' value is out of range, raise an *note OverflowError:
     a83.

     Set '*value' and return ‘0’ on success.  Set an exception and
     return ‘-1’ on error.

     'value' must not be ‘NULL’.

     Added in version 3.14.

 -- C Funzione: int PyLong_AsUInt32 (PyObject *obj, uint32_t *value)
 -- C Funzione: int PyLong_AsUInt64 (PyObject *obj, uint64_t *value)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Set
     '*value' to an unsigned C uint32_t or uint64_t representation of
     'obj'.

     If 'obj' is not an instance of *note PyLongObject: 39e, first call
     its *note __index__(): 19e. method (if present) to convert it to a
     *note PyLongObject: 39e.

        * If 'obj' is negative, raise a *note ValueError: 2ec.

        * If the 'obj' value is out of range, raise an *note
          OverflowError: a83.

     Set '*value' and return ‘0’ on success.  Set an exception and
     return ‘-1’ on error.

     'value' must not be ‘NULL’.

     Added in version 3.14.

 -- C Funzione: double PyLong_AsDouble (PyObject *pylong)
     ' Parte del *note ABI Stabile: 776.'  Return a C double
     representation of 'pylong'.  'pylong' must be an instance of *note
     PyLongObject: 39e.

     Raise *note OverflowError: a83. if the value of 'pylong' is out of
     range for a double.

     Returns ‘-1.0’ on error.  Use *note PyErr_Occurred(): 1c97. to
     disambiguate.

 -- C Funzione: void *PyLong_AsVoidPtr (PyObject *pylong)
     ' Parte del *note ABI Stabile: 776.'  Convert a Python integer
     'pylong' to a C void pointer.  If 'pylong' cannot be converted, an
     *note OverflowError: a83. will be raised.  This is only assured to
     produce a usable void pointer for values created with *note
     PyLong_FromVoidPtr(): 5025.

     Returns ‘NULL’ on error.  Use *note PyErr_Occurred(): 1c97. to
     disambiguate.

 -- C Funzione: *note Py_ssize_t: c57. PyLong_AsNativeBytes (PyObject
          *pylong, void *buffer, Py_ssize_t n_bytes, int flags)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Copy the
     Python integer value 'pylong' to a native 'buffer' of size
     'n_bytes'.  The 'flags' can be set to ‘-1’ to behave similarly to a
     C cast, or to values documented below to control the behavior.

     Returns ‘-1’ with an exception raised on error.  This may happen if
     'pylong' cannot be interpreted as an integer, or if 'pylong' was
     negative and the ‘Py_ASNATIVEBYTES_REJECT_NEGATIVE’ flag was set.

     Otherwise, returns the number of bytes required to store the value.
     If this is equal to or less than 'n_bytes', the entire value was
     copied.  All 'n_bytes' of the buffer are written: remaining bytes
     filled by copies of the sign bit.

     If the returned value is greater than 'n_bytes', the value was
     truncated: as many of the lowest bits of the value as could fit are
     written, and the higher bits are ignored.  This matches the typical
     behavior of a C-style downcast.

          Nota: Overflow is not considered an error.  If the returned
          value is larger than 'n_bytes', most significant bits were
          discarded.

     ‘0’ will never be returned.

     Values are always copied as two’s-complement.

     Usage example:

          int32_t value;
          Py_ssize_t bytes = PyLong_AsNativeBytes(pylong, &value, sizeof(value), -1);
          if (bytes < 0) {
              // Failed. A Python exception was set with the reason.
              return NULL;
          }
          else if (bytes <= (Py_ssize_t)sizeof(value)) {
              // Success!
          }
          else {
              // Overflow occurred, but 'value' contains the truncated
              // lowest bits of pylong.
          }

     Passing zero to 'n_bytes' will return the size of a buffer that
     would be large enough to hold the value.  This may be larger than
     technically necessary, but not unreasonably so.  If 'n_bytes=0',
     'buffer' may be ‘NULL’.

          Nota: Passing 'n_bytes=0' to this function is not an accurate
          way to determine the bit length of the value.

     To get at the entire Python value of an unknown size, the function
     can be called twice: first to determine the buffer size, then to
     fill it:

          // Ask how much space we need.
          Py_ssize_t expected = PyLong_AsNativeBytes(pylong, NULL, 0, -1);
          if (expected < 0) {
              // Failed. A Python exception was set with the reason.
              return NULL;
          }
          assert(expected != 0);  // Impossible per the API definition.
          uint8_t *bignum = malloc(expected);
          if (!bignum) {
              PyErr_SetString(PyExc_MemoryError, "bignum malloc failed.");
              return NULL;
          }
          // Safely get the entire value.
          Py_ssize_t bytes = PyLong_AsNativeBytes(pylong, bignum, expected, -1);
          if (bytes < 0) {  // Exception has been set.
              free(bignum);
              return NULL;
          }
          else if (bytes > expected) {  // This should not be possible.
              PyErr_SetString(PyExc_RuntimeError,
                  "Unexpected bignum truncation after a size check.");
              free(bignum);
              return NULL;
          }
          // The expected success given the above pre-check.
          // ... use bignum ...
          free(bignum);

     'flags' is either ‘-1’ (‘Py_ASNATIVEBYTES_DEFAULTS’) to select
     defaults that behave most like a C cast, or a combination of the
     other flags in the table below.  Note that ‘-1’ cannot be combined
     with other flags.

     Currently, ‘-1’ corresponds to ‘Py_ASNATIVEBYTES_NATIVE_ENDIAN |
     Py_ASNATIVEBYTES_UNSIGNED_BUFFER’.

     Flag                                              Value
                                                       
     -------------------------------------------------------------
                                                       
      -- C Macro: Py_ASNATIVEBYTES_DEFAULTS            ‘-1’
          ' Parte del *note ABI Stabile: 776. dalla    
          versione 3.14.'

      -- C Macro: Py_ASNATIVEBYTES_BIG_ENDIAN          ‘0’
          ' Parte del *note ABI Stabile: 776. dalla    
          versione 3.14.'

      -- C Macro: Py_ASNATIVEBYTES_LITTLE_ENDIAN       ‘1’
          ' Parte del *note ABI Stabile: 776. dalla    
          versione 3.14.'

      -- C Macro: Py_ASNATIVEBYTES_NATIVE_ENDIAN       ‘3’
          ' Parte del *note ABI Stabile: 776. dalla    
          versione 3.14.'

      -- C Macro: Py_ASNATIVEBYTES_UNSIGNED_BUFFER     ‘4’
          ' Parte del *note ABI Stabile: 776. dalla    
          versione 3.14.'

      -- C Macro: Py_ASNATIVEBYTES_REJECT_NEGATIVE     ‘8’
          ' Parte del *note ABI Stabile: 776. dalla    
          versione 3.14.'

      -- C Macro: Py_ASNATIVEBYTES_ALLOW_INDEX         ‘16’
          ' Parte del *note ABI Stabile: 776. dalla    
          versione 3.14.'

     Specifying ‘Py_ASNATIVEBYTES_NATIVE_ENDIAN’ will override any other
     endian flags.  Passing ‘2’ is reserved.

     By default, sufficient buffer will be requested to include a sign
     bit.  For example, when converting 128 with 'n_bytes=1', the
     function will return 2 (or more) in order to store a zero sign bit.

     If ‘Py_ASNATIVEBYTES_UNSIGNED_BUFFER’ is specified, a zero sign bit
     will be omitted from size calculations.  This allows, for example,
     128 to fit in a single-byte buffer.  If the destination buffer is
     later treated as signed, a positive input value may become
     negative.  Note that the flag does not affect handling of negative
     values: for those, space for a sign bit is always requested.

     Specifying ‘Py_ASNATIVEBYTES_REJECT_NEGATIVE’ causes an exception
     to be set if 'pylong' is negative.  Without this flag, negative
     values will be copied provided there is enough space for at least
     one sign bit, regardless of whether
     ‘Py_ASNATIVEBYTES_UNSIGNED_BUFFER’ was specified.

     If ‘Py_ASNATIVEBYTES_ALLOW_INDEX’ is specified and a non-integer
     value is passed, its *note __index__(): 19e. method will be called
     first.  This may result in Python code executing and other threads
     being allowed to run, which could cause changes to other objects or
     values in use.  When 'flags' is ‘-1’, this option is not set, and
     non-integer values will raise *note TypeError: 198.

          Nota: With the default 'flags' (‘-1’, or 'UNSIGNED_BUFFER'
          without 'REJECT_NEGATIVE'), multiple Python integers can map
          to a single value without overflow.  For example, both ‘255’
          and ‘-1’ fit a single-byte buffer and set all its bits.  This
          matches typical C cast behavior.

     Added in version 3.13.

 -- C Macro: PyLong_AsPid (pid)

     Macro for converting a Python integer into a process identifier.

     This can be defined as an alias to *note PyLong_AsLong(): 605,
     *note PyLong_FromLongLong(): 1bb9, or *note PyLong_AsInt(): 604,
     depending on the size of the system’s PID type.

     Added in version 3.2.

 -- C Funzione: int PyLong_GetSign (PyObject *obj, int *sign)

     Get the sign of the integer object 'obj'.

     On success, set '*sign' to the integer sign (0, -1 or +1 for zero,
     negative or positive integer, respectively) and return 0.

     On failure, return -1 with an exception set.  This function always
     succeeds if 'obj' is a *note PyLongObject: 39e. or its subtype.

     Added in version 3.14.

 -- C Funzione: int PyLong_IsPositive (PyObject *obj)

     Check if the integer object 'obj' is positive (‘obj > 0’).

     If 'obj' is an instance of *note PyLongObject: 39e. or its subtype,
     return ‘1’ when it’s positive and ‘0’ otherwise.  Else set an
     exception and return ‘-1’.

     Added in version 3.14.

 -- C Funzione: int PyLong_IsNegative (PyObject *obj)

     Check if the integer object 'obj' is negative (‘obj < 0’).

     If 'obj' is an instance of *note PyLongObject: 39e. or its subtype,
     return ‘1’ when it’s negative and ‘0’ otherwise.  Else set an
     exception and return ‘-1’.

     Added in version 3.14.

 -- C Funzione: int PyLong_IsZero (PyObject *obj)

     Check if the integer object 'obj' is zero.

     If 'obj' is an instance of *note PyLongObject: 39e. or its subtype,
     return ‘1’ when it’s zero and ‘0’ otherwise.  Else set an exception
     and return ‘-1’.

     Added in version 3.14.

 -- C Funzione: *note PyObject: 5df. *PyLong_GetInfo (void)
     ' Parte del *note ABI Stabile: 776.'  On success, return a read
     only *note named tuple: 85f, that holds information about Python’s
     internal representation of integers.  See *note sys.int_info: 149b.
     for description of individual fields.

     On failure, return ‘NULL’ with an exception set.

     Added in version 3.1.

 -- C Funzione: int PyUnstable_Long_IsCompact (const PyLongObject *op)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Return 1 if 'op' is compact, 0 otherwise.

     This function makes it possible for performance-critical code to
     implement a “fast path” for small integers.  For compact values use
     *note PyUnstable_Long_CompactValue(): 7a8.; for others fall back to
     a *note PyLong_As*: 501f. function or *note PyLong_AsNativeBytes():
     606.

     The speedup is expected to be negligible for most users.

     Exactly what values are considered compact is an implementation
     detail and is subject to change.

     Added in version 3.12.

 -- C Funzione: *note Py_ssize_t: c57. PyUnstable_Long_CompactValue
          (const PyLongObject *op)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     If 'op' is compact, as determined by *note
     PyUnstable_Long_IsCompact(): 7a7, return its value.

     Otherwise, the return value is undefined.

     Added in version 3.12.

* Menu:

* Export API::
* PyLongWriter API::
* Deprecated API::


File: python.info,  Node: Export API,  Next: PyLongWriter API,  Up: Integer Objects

7.9.2.2 Export API
..................

Added in version 3.14.

 -- C Struct: struct PyLongLayout

     Layout of an array of «digits» («limbs» in the GMP terminology),
     used to represent absolute value for arbitrary precision integers.

     Use *note PyLong_GetNativeLayout(): 3a7. to get the native layout
     of Python *note int: 19b. objects, used internally for integers
     with «big enough» absolute value.

     See also *note sys.int_info: 149b. which exposes similar
     information in Python.

      -- C Membro: uint8_t bits_per_digit

          Bits per digit.  For example, a 15 bit digit means that bits
          0-14 contain meaningful information.

      -- C Membro: uint8_t digit_size

          Digit size in bytes.  For example, a 15 bit digit will require
          at least 2 bytes.

      -- C Membro: int8_t digits_order

          Digits order:

             - ‘1’ for most significant digit first

             - ‘-1’ for least significant digit first

      -- C Membro: int8_t digit_endianness

          Digit endianness:

             - ‘1’ for most significant byte first (big endian)

             - ‘-1’ for least significant byte first (little endian)

 -- C Funzione: const *note PyLongLayout: 52da. *PyLong_GetNativeLayout
          (void)

     Get the native layout of Python *note int: 19b. objects.

     See the *note PyLongLayout: 52da. structure.

     The function must not be called before Python initialization nor
     after Python finalization.  The returned layout is valid until
     Python is finalized.  The layout is the same for all Python
     sub-interpreters in a process, and so it can be cached.

 -- C Struct: struct PyLongExport

     Export of a Python *note int: 19b. object.

     There are two cases:

        * If *note digits: 52e0. is ‘NULL’, only use the *note value:
          52e1. member.

        * If *note digits: 52e0. is not ‘NULL’, use *note negative:
          52e2, *note ndigits: 52e3. and *note digits: 52e0. members.

      -- C Membro: int64_t value

          The native integer value of the exported *note int: 19b.
          object.  Only valid if *note digits: 52e0. is ‘NULL’.

      -- C Membro: uint8_t negative

          ‘1’ if the number is negative, ‘0’ otherwise.  Only valid if
          *note digits: 52e0. is not ‘NULL’.

      -- C Membro: *note Py_ssize_t: c57. ndigits

          Number of digits in *note digits: 52e0. array.  Only valid if
          *note digits: 52e0. is not ‘NULL’.

      -- C Membro: const void *digits

          Read-only array of unsigned digits.  Can be ‘NULL’.

 -- C Funzione: int PyLong_Export (PyObject *obj, PyLongExport
          *export_long)

     Export a Python *note int: 19b. object.

     'export_long' must point to a *note PyLongExport: 52df. structure
     allocated by the caller.  It must not be ‘NULL’.

     On success, fill in '*export_long' and return ‘0’.  On error, set
     an exception and return ‘-1’.

     *note PyLong_FreeExport(): 3a9. must be called when the export is
     no longer needed.

          'Dettaglio dell’implementazione di CPython:' This function
          always succeeds if 'obj' is a Python *note int: 19b. object or
          a subclass.

 -- C Funzione: void PyLong_FreeExport (PyLongExport *export_long)

     Release the export 'export_long' created by *note PyLong_Export():
     3a8.

     'Dettaglio dell’implementazione di CPython:' Calling *note
     PyLong_FreeExport(): 3a9. is optional if 'export_long->digits' is
     ‘NULL’.


File: python.info,  Node: PyLongWriter API,  Next: Deprecated API,  Prev: Export API,  Up: Integer Objects

7.9.2.3 PyLongWriter API
........................

The *note PyLongWriter: 52e5. API can be used to import an integer.

Added in version 3.14.

 -- C Struct: struct PyLongWriter

     A Python *note int: 19b. writer instance.

     The instance must be destroyed by *note PyLongWriter_Finish(): 3ab.
     or *note PyLongWriter_Discard(): 3ac.

 -- C Funzione: *note PyLongWriter: 52e5. *PyLongWriter_Create (int
          negative, Py_ssize_t ndigits, void **digits)

     Create a *note PyLongWriter: 52e5.

     On success, allocate '*digits' and return a writer.  On error, set
     an exception and return ‘NULL’.

     'negative' is ‘1’ if the number is negative, or ‘0’ otherwise.

     'ndigits' is the number of digits in the 'digits' array.  It must
     be greater than 0.

     'digits' must not be NULL.

     After a successful call to this function, the caller should fill in
     the array of digits 'digits' and then call *note
     PyLongWriter_Finish(): 3ab. to get a Python *note int: 19b.  The
     layout of 'digits' is described by *note PyLong_GetNativeLayout():
     3a7.

     Digits must be in the range [‘0’; ‘(1 << bits_per_digit) - 1’]
     (where the *note bits_per_digit: 52db. is the number of bits per
     digit).  Any unused most significant digits must be set to ‘0’.

     Alternately, call *note PyLongWriter_Discard(): 3ac. to destroy the
     writer instance without creating an *note int: 19b. object.

 -- C Funzione: *note PyObject: 5df. *PyLongWriter_Finish (PyLongWriter
          *writer)
     'Valore di ritorno: Nuovo riferimento.'  Finish a *note
     PyLongWriter: 52e5. created by *note PyLongWriter_Create(): 3aa.

     On success, return a Python *note int: 19b. object.  On error, set
     an exception and return ‘NULL’.

     The function takes care of normalizing the digits and converts the
     object to a compact integer if needed.

     The writer instance and the 'digits' array are invalid after the
     call.

 -- C Funzione: void PyLongWriter_Discard (PyLongWriter *writer)

     Discard a *note PyLongWriter: 52e5. created by *note
     PyLongWriter_Create(): 3aa.

     If 'writer' is ‘NULL’, no operation is performed.

     The writer instance and the 'digits' array are invalid after the
     call.


File: python.info,  Node: Deprecated API,  Prev: PyLongWriter API,  Up: Integer Objects

7.9.2.4 Deprecated API
......................

These macros are *note soft deprecated: 23d.  They describe parameters
of the internal representation of *note PyLongObject: 39e. instances.

Use *note PyLong_GetNativeLayout(): 3a7. instead, along with *note
PyLong_Export(): 3a8. to read integer data or *note PyLongWriter: 52e5.
to write it.  These currently use the same layout, but are designed to
continue working correctly even if CPython’s internal integer
representation changes.

 -- C Macro: PyLong_SHIFT

     This is equivalent to *note bits_per_digit: 52db. in the output of
     *note PyLong_GetNativeLayout(): 3a7.

 -- C Macro: PyLong_BASE

     This is currently equivalent to 1 << *note PyLong_SHIFT: 52e7.

 -- C Macro: PyLong_MASK

     This is currently equivalent to (1 << *note PyLong_SHIFT: 52e7.) -
     1


File: python.info,  Node: Boolean Objects,  Next: Floating-Point Objects,  Prev: Integer Objects,  Up: Numeric Objects

7.9.2.5 Boolean Objects
.......................

Booleans in Python are implemented as a subclass of integers.  There are
only two booleans, *note Py_False: 52ed. and *note Py_True: 52ee.  As
such, the normal creation and deletion functions don’t apply to
booleans.  The following macros are available, however.

 -- C Variabile: *note PyTypeObject: c9e. PyBool_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python boolean type; it is the
     same object as *note bool: 3c3. in the Python layer.

 -- C Funzione: int PyBool_Check (PyObject *o)

     Return true if 'o' is of type *note PyBool_Type: 4f4f.  This
     function always succeeds.

 -- C Variabile: *note PyObject: 5df. *Py_False

     The Python ‘False’ object.  This object has no methods and is *note
     immortal: 290.

     Cambiato nella versione 3.12: *note Py_False: 52ed. is *note
     immortal: 290.

 -- C Variabile: *note PyObject: 5df. *Py_True

     The Python ‘True’ object.  This object has no methods and is *note
     immortal: 290.

     Cambiato nella versione 3.12: *note Py_True: 52ee. is *note
     immortal: 290.

 -- C Macro: Py_RETURN_FALSE

     Return *note Py_False: 52ed. from a function.

 -- C Macro: Py_RETURN_TRUE

     Return *note Py_True: 52ee. from a function.

 -- C Funzione: *note PyObject: 5df. *PyBool_FromLong (long v)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return *note Py_True: 52ee. or *note Py_False:
     52ed, depending on the truth value of 'v'.


File: python.info,  Node: Floating-Point Objects,  Next: Complex Number Objects,  Prev: Boolean Objects,  Up: Numeric Objects

7.9.2.6 Floating-Point Objects
..............................

 -- C Tipo: type PyFloatObject

     This subtype of *note PyObject: 5df. represents a Python
     floating-point object.

 -- C Variabile: *note PyTypeObject: c9e. PyFloat_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python floating-point type.  This
     is the same object as *note float: 196. in the Python layer.

 -- C Funzione: int PyFloat_Check (PyObject *p)

     Return true if its argument is a *note PyFloatObject: 52f4. or a
     subtype of *note PyFloatObject: 52f4.  This function always
     succeeds.

 -- C Funzione: int PyFloat_CheckExact (PyObject *p)

     Return true if its argument is a *note PyFloatObject: 52f4, but not
     a subtype of *note PyFloatObject: 52f4.  This function always
     succeeds.

 -- C Funzione: *note PyObject: 5df. *PyFloat_FromString (PyObject *str)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a *note PyFloatObject: 52f4. object based on
     the string value in 'str', or ‘NULL’ on failure.

 -- C Funzione: *note PyObject: 5df. *PyFloat_FromDouble (double v)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a *note PyFloatObject: 52f4. object from
     'v', or ‘NULL’ on failure.

 -- C Funzione: double PyFloat_AsDouble (PyObject *pyfloat)
     ' Parte del *note ABI Stabile: 776.'  Return a C double
     representation of the contents of 'pyfloat'.  If 'pyfloat' is not a
     Python floating-point object but has a *note __float__(): bc3.
     method, this method will first be called to convert 'pyfloat' into
     a float.  If ‘__float__()’ is not defined then it falls back to
     *note __index__(): 19e.  This method returns ‘-1.0’ upon failure,
     so one should call *note PyErr_Occurred(): 1c97. to check for
     errors.

     Cambiato nella versione 3.8: Use *note __index__(): 19e. if
     available.

 -- C Funzione: double PyFloat_AS_DOUBLE (PyObject *pyfloat)

     Return a C double representation of the contents of 'pyfloat', but
     without error checking.

 -- C Funzione: *note PyObject: 5df. *PyFloat_GetInfo (void)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a structseq instance which contains
     information about the precision, minimum and maximum values of a
     float.  It’s a thin wrapper around the header file ‘float.h’.

 -- C Funzione: double PyFloat_GetMax ()
     ' Parte del *note ABI Stabile: 776.'  Return the maximum
     representable finite float 'DBL_MAX' as C double.

 -- C Funzione: double PyFloat_GetMin ()
     ' Parte del *note ABI Stabile: 776.'  Return the minimum normalized
     positive float 'DBL_MIN' as C double.

 -- C Macro: Py_INFINITY

     This macro expands a to constant expression of type double, that
     represents the positive infinity.

     On most platforms, this is equivalent to the ‘INFINITY’ macro from
     the C11 standard ‘<math.h>’ header.

 -- C Macro: Py_NAN

     This macro expands a to constant expression of type double, that
     represents a quiet not-a-number (qNaN) value.

     On most platforms, this is equivalent to the ‘NAN’ macro from the
     C11 standard ‘<math.h>’ header.

 -- C Macro: Py_HUGE_VAL

     Equivalent to ‘INFINITY’.

     Deprecato dalla versione 3.14: The macro is *note soft deprecated:
     23d.

 -- C Macro: Py_MATH_E

     The definition (accurate for a double type) of the *note math.e:
     2a66. constant.

 -- C Macro: Py_MATH_El

     High precision (long double) definition of *note e: 2a66. constant.

 -- C Macro: Py_MATH_PI

     The definition (accurate for a double type) of the *note math.pi:
     2a65. constant.

 -- C Macro: Py_MATH_PIl

     High precision (long double) definition of *note pi: 2a65.
     constant.

 -- C Macro: Py_MATH_TAU

     The definition (accurate for a double type) of the *note math.tau:
     2a67. constant.

     Added in version 3.6.

 -- C Macro: Py_RETURN_NAN

     Return *note math.nan: 874. from a function.

     On most platforms, this is equivalent to ‘return
     PyFloat_FromDouble(NAN)’.

 -- C Macro: Py_RETURN_INF (sign)

     Return *note math.inf: e82. or *note -math.inf: e82. from a
     function, depending on the sign of 'sign'.

     On most platforms, this is equivalent to the following:

          return PyFloat_FromDouble(copysign(INFINITY, sign));

 -- C Macro: Py_IS_FINITE (X)

     Return ‘1’ if the given floating-point number 'X' is finite, that
     is, it is normal, subnormal or zero, but not infinite or NaN.
     Return ‘0’ otherwise.

     Deprecato dalla versione 3.14: The macro is *note soft deprecated:
     23d.  Use ‘isfinite’ instead.

 -- C Macro: Py_IS_INFINITY (X)

     Return ‘1’ if the given floating-point number 'X' is positive or
     negative infinity.  Return ‘0’ otherwise.

     Deprecato dalla versione 3.14: The macro is *note soft deprecated:
     23d.  Use ‘isinf’ instead.

 -- C Macro: Py_IS_NAN (X)

     Return ‘1’ if the given floating-point number 'X' is a not-a-number
     (NaN) value.  Return ‘0’ otherwise.

     Deprecato dalla versione 3.14: The macro is *note soft deprecated:
     23d.  Use ‘isnan’ instead.

* Menu:

* Pack and Unpack functions::


File: python.info,  Node: Pack and Unpack functions,  Up: Floating-Point Objects

7.9.2.7 Pack and Unpack functions
.................................

The pack and unpack functions provide an efficient platform-independent
way to store floating-point values as byte strings.  The Pack routines
produce a bytes string from a C double, and the Unpack routines produce
a C double from such a bytes string.  The suffix (2, 4 or 8) specifies
the number of bytes in the bytes string.

On platforms that appear to use IEEE 754 formats these functions work by
copying bits.  On other platforms, the 2-byte format is identical to the
IEEE 754 binary16 half-precision format, the 4-byte format (32-bit) is
identical to the IEEE 754 binary32 single precision format, and the
8-byte format to the IEEE 754 binary64 double precision format, although
the packing of INFs and NaNs (if such things exist on the platform)
isn’t handled correctly, and attempting to unpack a bytes string
containing an IEEE INF or NaN will raise an exception.

Note that NaNs type may not be preserved on IEEE platforms (signaling
NaN become quiet NaN), for example on x86 systems in 32-bit mode.

On non-IEEE platforms with more precision, or larger dynamic range, than
IEEE 754 supports, not all values can be packed; on non-IEEE platforms
with less precision, or smaller dynamic range, not all values can be
unpacked.  What happens in such cases is partly accidental (alas).

Added in version 3.11.

* Menu:

* Pack functions::
* Unpack functions::


File: python.info,  Node: Pack functions,  Next: Unpack functions,  Up: Pack and Unpack functions

7.9.2.8 Pack functions
......................

The pack routines write 2, 4 or 8 bytes, starting at 'p'.  'le' is an
int argument, non-zero if you want the bytes string in little-endian
format (exponent last, at ‘p+1’, ‘p+3’, or ‘p+6’ ‘p+7’), zero if you
want big-endian format (exponent first, at 'p').  The ‘PY_BIG_ENDIAN’
constant can be used to use the native endian: it is equal to ‘1’ on big
endian processor, or ‘0’ on little endian processor.

Return value: ‘0’ if all is OK, ‘-1’ if error (and an exception is set,
most likely *note OverflowError: a83.).

There are two problems on non-IEEE platforms:

   * What this does is undefined if 'x' is a NaN or infinity.

   * ‘-0.0’ and ‘+0.0’ produce the same bytes string.

 -- C Funzione: int PyFloat_Pack2 (double x, char *p, int le)

     Pack a C double as the IEEE 754 binary16 half-precision format.

 -- C Funzione: int PyFloat_Pack4 (double x, char *p, int le)

     Pack a C double as the IEEE 754 binary32 single precision format.

 -- C Funzione: int PyFloat_Pack8 (double x, char *p, int le)

     Pack a C double as the IEEE 754 binary64 double precision format.


File: python.info,  Node: Unpack functions,  Prev: Pack functions,  Up: Pack and Unpack functions

7.9.2.9 Unpack functions
........................

The unpack routines read 2, 4 or 8 bytes, starting at 'p'.  'le' is an
int argument, non-zero if the bytes string is in little-endian format
(exponent last, at ‘p+1’, ‘p+3’ or ‘p+6’ and ‘p+7’), zero if big-endian
(exponent first, at 'p').  The ‘PY_BIG_ENDIAN’ constant can be used to
use the native endian: it is equal to ‘1’ on big endian processor, or
‘0’ on little endian processor.

Return value: The unpacked double.  On error, this is ‘-1.0’ and *note
PyErr_Occurred(): 1c97. is true (and an exception is set, most likely
*note OverflowError: a83.).

Note that on a non-IEEE platform this will refuse to unpack a bytes
string that represents a NaN or infinity.

 -- C Funzione: double PyFloat_Unpack2 (const char *p, int le)

     Unpack the IEEE 754 binary16 half-precision format as a C double.

 -- C Funzione: double PyFloat_Unpack4 (const char *p, int le)

     Unpack the IEEE 754 binary32 single precision format as a C double.

 -- C Funzione: double PyFloat_Unpack8 (const char *p, int le)

     Unpack the IEEE 754 binary64 double precision format as a C double.


File: python.info,  Node: Complex Number Objects,  Prev: Floating-Point Objects,  Up: Numeric Objects

7.9.2.10 Complex Number Objects
...............................

Python’s complex number objects are implemented as two distinct types
when viewed from the C API: one is the Python object exposed to Python
programs, and the other is a C structure which represents the actual
complex number value.  The API provides functions for working with both.

* Menu:

* Complex Numbers as C Structures::
* Complex Numbers as Python Objects::


File: python.info,  Node: Complex Numbers as C Structures,  Next: Complex Numbers as Python Objects,  Up: Complex Number Objects

7.9.2.11 Complex Numbers as C Structures
........................................

Note that the functions which accept these structures as parameters and
return them as results do so 'by value' rather than dereferencing them
through pointers.  This is consistent throughout the API.

 -- C Tipo: type Py_complex

     The C structure which corresponds to the value portion of a Python
     complex number object.  Most of the functions for dealing with
     complex number objects use structures of this type as input or
     output values, as appropriate.

      -- C Membro: double real
      -- C Membro: double imag

     The structure is defined as:

          typedef struct {
              double real;
              double imag;
          } Py_complex;

 -- C Funzione: *note Py_complex: 5215. _Py_c_sum (Py_complex left,
          Py_complex right)

     Return the sum of two complex numbers, using the C *note
     Py_complex: 5215. representation.

 -- C Funzione: *note Py_complex: 5215. _Py_c_diff (Py_complex left,
          Py_complex right)

     Return the difference between two complex numbers, using the C
     *note Py_complex: 5215. representation.

 -- C Funzione: *note Py_complex: 5215. _Py_c_neg (Py_complex num)

     Return the negation of the complex number 'num', using the C *note
     Py_complex: 5215. representation.

 -- C Funzione: *note Py_complex: 5215. _Py_c_prod (Py_complex left,
          Py_complex right)

     Return the product of two complex numbers, using the C *note
     Py_complex: 5215. representation.

 -- C Funzione: *note Py_complex: 5215. _Py_c_quot (Py_complex dividend,
          Py_complex divisor)

     Return the quotient of two complex numbers, using the C *note
     Py_complex: 5215. representation.

     If 'divisor' is null, this method returns zero and sets ‘errno’ to
     ‘EDOM’.

 -- C Funzione: *note Py_complex: 5215. _Py_c_pow (Py_complex num,
          Py_complex exp)

     Return the exponentiation of 'num' by 'exp', using the C *note
     Py_complex: 5215. representation.

     If 'num' is null and 'exp' is not a positive real number, this
     method returns zero and sets ‘errno’ to ‘EDOM’.

     Set ‘errno’ to ‘ERANGE’ on overflows.


File: python.info,  Node: Complex Numbers as Python Objects,  Prev: Complex Numbers as C Structures,  Up: Complex Number Objects

7.9.2.12 Complex Numbers as Python Objects
..........................................

 -- C Tipo: type PyComplexObject

     This subtype of *note PyObject: 5df. represents a Python complex
     number object.

 -- C Variabile: *note PyTypeObject: c9e. PyComplex_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python complex number type.  It
     is the same object as *note complex: 197. in the Python layer.

 -- C Funzione: int PyComplex_Check (PyObject *p)

     Return true if its argument is a *note PyComplexObject: 5314. or a
     subtype of *note PyComplexObject: 5314.  This function always
     succeeds.

 -- C Funzione: int PyComplex_CheckExact (PyObject *p)

     Return true if its argument is a *note PyComplexObject: 5314, but
     not a subtype of *note PyComplexObject: 5314.  This function always
     succeeds.

 -- C Funzione: *note PyObject: 5df. *PyComplex_FromCComplex (Py_complex
          v)
     'Valore di ritorno: Nuovo riferimento.'  Create a new Python
     complex number object from a C *note Py_complex: 5215. value.
     Return ‘NULL’ with an exception set on error.

 -- C Funzione: *note PyObject: 5df. *PyComplex_FromDoubles (double
          real, double imag)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new *note PyComplexObject: 5314. object
     from 'real' and 'imag'.  Return ‘NULL’ with an exception set on
     error.

 -- C Funzione: double PyComplex_RealAsDouble (PyObject *op)
     ' Parte del *note ABI Stabile: 776.'  Return the real part of 'op'
     as a C double.

     If 'op' is not a Python complex number object but has a *note
     __complex__(): 7fe. method, this method will first be called to
     convert 'op' to a Python complex number object.  If ‘__complex__()’
     is not defined then it falls back to call *note PyFloat_AsDouble():
     c61. and returns its result.

     Upon failure, this method returns ‘-1.0’ with an exception set, so
     one should call *note PyErr_Occurred(): 1c97. to check for errors.

     Cambiato nella versione 3.13: Use *note __complex__(): 7fe. if
     available.

 -- C Funzione: double PyComplex_ImagAsDouble (PyObject *op)
     ' Parte del *note ABI Stabile: 776.'  Return the imaginary part of
     'op' as a C double.

     If 'op' is not a Python complex number object but has a *note
     __complex__(): 7fe. method, this method will first be called to
     convert 'op' to a Python complex number object.  If ‘__complex__()’
     is not defined then it falls back to call *note PyFloat_AsDouble():
     c61. and returns ‘0.0’ on success.

     Upon failure, this method returns ‘-1.0’ with an exception set, so
     one should call *note PyErr_Occurred(): 1c97. to check for errors.

     Cambiato nella versione 3.13: Use *note __complex__(): 7fe. if
     available.

 -- C Funzione: *note Py_complex: 5215. PyComplex_AsCComplex (PyObject
          *op)

     Return the *note Py_complex: 5215. value of the complex number
     'op'.

     If 'op' is not a Python complex number object but has a *note
     __complex__(): 7fe. method, this method will first be called to
     convert 'op' to a Python complex number object.  If ‘__complex__()’
     is not defined then it falls back to *note __float__(): bc3.  If
     ‘__float__()’ is not defined then it falls back to *note
     __index__(): 19e.

     Upon failure, this method returns *note Py_complex: 5215. with
     *note real: 530c. set to ‘-1.0’ and with an exception set, so one
     should call *note PyErr_Occurred(): 1c97. to check for errors.

     Cambiato nella versione 3.8: Use *note __index__(): 19e. if
     available.


File: python.info,  Node: Sequence Objects,  Next: Container Objects,  Prev: Numeric Objects,  Up: Concrete Objects Layer

7.9.3 Sequence Objects
----------------------

Generic operations on sequence objects were discussed in the previous
chapter; this section deals with the specific kinds of sequence objects
that are intrinsic to the Python language.

* Menu:

* Bytes Objects::
* Byte Array Objects::
* Unicode Objects and Codecs::
* Tuple Objects::
* Struct Sequence Objects::
* List Objects::


File: python.info,  Node: Bytes Objects,  Next: Byte Array Objects,  Up: Sequence Objects

7.9.3.1 Bytes Objects
.....................

These functions raise *note TypeError: 198. when expecting a bytes
parameter and called with a non-bytes parameter.

 -- C Tipo: type PyBytesObject

     This subtype of *note PyObject: 5df. represents a Python bytes
     object.

 -- C Variabile: *note PyTypeObject: c9e. PyBytes_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python bytes type; it is the same
     object as *note bytes: 192. in the Python layer.

 -- C Funzione: int PyBytes_Check (PyObject *o)

     Return true if the object 'o' is a bytes object or an instance of a
     subtype of the bytes type.  This function always succeeds.

 -- C Funzione: int PyBytes_CheckExact (PyObject *o)

     Return true if the object 'o' is a bytes object, but not an
     instance of a subtype of the bytes type.  This function always
     succeeds.

 -- C Funzione: *note PyObject: 5df. *PyBytes_FromString (const char *v)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new bytes object with a copy of the string
     'v' as value on success, and ‘NULL’ on failure.  The parameter 'v'
     must not be ‘NULL’; it will not be checked.

 -- C Funzione: *note PyObject: 5df. *PyBytes_FromStringAndSize (const
          char *v, Py_ssize_t len)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new bytes object with a copy of the string
     'v' as value and length 'len' on success, and ‘NULL’ on failure.
     If 'v' is ‘NULL’, the contents of the bytes object are
     uninitialized.

 -- C Funzione: *note PyObject: 5df. *PyBytes_FromFormat (const char
          *format, ...)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Take a C ‘printf()’-style 'format' string and a
     variable number of arguments, calculate the size of the resulting
     Python bytes object and return a bytes object with the values
     formatted into it.  The variable arguments must be C types and must
     correspond exactly to the format characters in the 'format' string.
     The following format characters are allowed:

     Format Characters       Type                Comment
                                                 
     ---------------------------------------------------------------------------------
                                                 
     ‘%%’                    'n/a'               The literal % character.
                                                 
                                                 
     ‘%c’                    int                 A single byte, represented as a C
                                                 int.
                                                 
                                                 
     ‘%d’                    int                 Equivalent to ‘printf("%d")’.  (1)
                                                 
                                                 
     ‘%u’                    unsigned int        Equivalent to ‘printf("%u")’.  (2)
                                                 
                                                 
     ‘%ld’                   long                Equivalent to ‘printf("%ld")’.
                                                 (3)
                                                 
                                                 
     ‘%lu’                   unsigned long       Equivalent to ‘printf("%lu")’.
                                                 (4)
                                                 
                                                 
     ‘%zd’                   *note Py_ssize_t: c57.Equivalent to ‘printf("%zd")’.
                                                 (5)
                                                 
                                                 
     ‘%zu’                   size_t              Equivalent to ‘printf("%zu")’.
                                                 (6)
                                                 
                                                 
     ‘%i’                    int                 Equivalent to ‘printf("%i")’.  (7)
                                                 
                                                 
     ‘%x’                    int                 Equivalent to ‘printf("%x")’.  (8)
                                                 
                                                 
     ‘%s’                    const char*         A null-terminated C character
                                                 array.
                                                 
                                                 
     ‘%p’                    const void*         The hex representation of a C
                                                 pointer.  Mostly equivalent to
                                                 ‘printf("%p")’ except that it is
                                                 guaranteed to start with the
                                                 literal ‘0x’ regardless of what
                                                 the platform’s ‘printf’ yields.
                                                 

     An unrecognized format character causes all the rest of the format
     string to be copied as-is to the result object, and any extra
     arguments discarded.

 -- C Funzione: *note PyObject: 5df. *PyBytes_FromFormatV (const char
          *format, va_list vargs)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Identical to *note PyBytes_FromFormat(): 1df3.
     except that it takes exactly two arguments.

 -- C Funzione: *note PyObject: 5df. *PyBytes_FromObject (PyObject *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the bytes representation of object 'o' that
     implements the buffer protocol.

 -- C Funzione: *note Py_ssize_t: c57. PyBytes_Size (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Return the length of the
     bytes in bytes object 'o'.

 -- C Funzione: *note Py_ssize_t: c57. PyBytes_GET_SIZE (PyObject *o)

     Similar to *note PyBytes_Size(): 4f5f, but without error checking.

 -- C Funzione: char *PyBytes_AsString (PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Return a pointer to the
     contents of 'o'.  The pointer refers to the internal buffer of 'o',
     which consists of ‘len(o) + 1’ bytes.  The last byte in the buffer
     is always null, regardless of whether there are any other null
     bytes.  The data must not be modified in any way, unless the object
     was just created using ‘PyBytes_FromStringAndSize(NULL, size)’.  It
     must not be deallocated.  If 'o' is not a bytes object at all,
     *note PyBytes_AsString(): a89. returns ‘NULL’ and raises *note
     TypeError: 198.

 -- C Funzione: char *PyBytes_AS_STRING (PyObject *string)

     Similar to *note PyBytes_AsString(): a89, but without error
     checking.

 -- C Funzione: int PyBytes_AsStringAndSize (PyObject *obj, char
          **buffer, Py_ssize_t *length)
     ' Parte del *note ABI Stabile: 776.'  Return the null-terminated
     contents of the object 'obj' through the output variables 'buffer'
     and 'length'.  Returns ‘0’ on success.

     If 'length' is ‘NULL’, the bytes object may not contain embedded
     null bytes; if it does, the function returns ‘-1’ and a *note
     ValueError: 2ec. is raised.

     The buffer refers to an internal buffer of 'obj', which includes an
     additional null byte at the end (not counted in 'length').  The
     data must not be modified in any way, unless the object was just
     created using ‘PyBytes_FromStringAndSize(NULL, size)’.  It must not
     be deallocated.  If 'obj' is not a bytes object at all, *note
     PyBytes_AsStringAndSize(): 4f57. returns ‘-1’ and raises *note
     TypeError: 198.

     Cambiato nella versione 3.5: Previously, *note TypeError: 198. was
     raised when embedded null bytes were encountered in the bytes
     object.

 -- C Funzione: void PyBytes_Concat (PyObject **bytes, PyObject
          *newpart)
     ' Parte del *note ABI Stabile: 776.'  Create a new bytes object in
     '*bytes' containing the contents of 'newpart' appended to 'bytes';
     the caller will own the new reference.  The reference to the old
     value of 'bytes' will be stolen.  If the new object cannot be
     created, the old reference to 'bytes' will still be discarded and
     the value of '*bytes' will be set to ‘NULL’; the appropriate
     exception will be set.

 -- C Funzione: void PyBytes_ConcatAndDel (PyObject **bytes, PyObject
          *newpart)
     ' Parte del *note ABI Stabile: 776.'  Create a new bytes object in
     '*bytes' containing the contents of 'newpart' appended to 'bytes'.
     This version releases the *note strong reference: 5e2. to 'newpart'
     (i.e.  decrements its reference count).

 -- C Funzione: *note PyObject: 5df. *PyBytes_Join (PyObject *sep,
          PyObject *iterable)

     Similar to ‘sep.join(iterable)’ in Python.

     'sep' must be Python *note bytes: 192. object.  (Note that *note
     PyUnicode_Join(): 13aa. accepts ‘NULL’ separator and treats it as a
     space, whereas *note PyBytes_Join(): 383. doesn’t accept ‘NULL’
     separator.)

     'iterable' must be an iterable object yielding objects that
     implement the *note buffer protocol: 260.

     On success, return a new *note bytes: 192. object.  On error, set
     an exception and return ‘NULL’.

     Added in version 3.14.

 -- C Funzione: int _PyBytes_Resize (PyObject **bytes, Py_ssize_t
          newsize)

     Resize a bytes object.  'newsize' will be the new length of the
     bytes object.  You can think of it as creating a new bytes object
     and destroying the old one, only more efficiently.  Pass the
     address of an existing bytes object as an lvalue (it may be written
     into), and the new size desired.  On success, '*bytes' holds the
     resized bytes object and ‘0’ is returned; the address in '*bytes'
     may differ from its input value.  If the reallocation fails, the
     original bytes object at '*bytes' is deallocated, '*bytes' is set
     to ‘NULL’, *note MemoryError: 1786. is set, and ‘-1’ is returned.

 -- C Funzione: *note PyObject: 5df. *PyBytes_Repr (PyObject *bytes, int
          smartquotes)
     ' Parte del *note ABI Stabile: 776.'  Get the string representation
     of 'bytes'.  This function is currently used to implement
     ‘bytes.__repr__()’ in Python.

     This function does not do type checking; it is undefined behavior
     to pass 'bytes' as a non-bytes object or ‘NULL’.

     If 'smartquotes' is true, the representation will use a
     double-quoted string instead of single-quoted string when
     single-quotes are present in 'bytes'.  For example, the byte string
     ‘'Python'’ would be represented as ‘b"'Python'"’ when 'smartquotes'
     is true, or ‘b'\'Python\''’ when it is false.

     On success, this function returns a *note strong reference: 5e2. to
     a *note str: 169. object containing the representation.  On
     failure, this returns ‘NULL’ with an exception set.

 -- C Funzione: *note PyObject: 5df. *PyBytes_DecodeEscape (const char
          *s, Py_ssize_t len, const char *errors, Py_ssize_t unicode,
          const char *recode_encoding)
     ' Parte del *note ABI Stabile: 776.'  Unescape a backslash-escaped
     string 's'.  's' must not be ‘NULL’.  'len' must be the size of
     's'.

     'errors' must be one of ‘"strict"’, ‘"replace"’, or ‘"ignore"’.  If
     'errors' is ‘NULL’, then ‘"strict"’ is used by default.

     On success, this function returns a *note strong reference: 5e2. to
     a Python *note bytes: 192. object containing the unescaped string.
     On failure, this function returns ‘NULL’ with an exception set.

     Cambiato nella versione 3.9: 'unicode' and 'recode_encoding' are
     now unused.

   ---------- Footnotes ----------

   (1) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the
0-conversion flag has effect even when a precision is given.

   (2) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the
0-conversion flag has effect even when a precision is given.

   (3) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the
0-conversion flag has effect even when a precision is given.

   (4) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the
0-conversion flag has effect even when a precision is given.

   (5) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the
0-conversion flag has effect even when a precision is given.

   (6) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the
0-conversion flag has effect even when a precision is given.

   (7) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the
0-conversion flag has effect even when a precision is given.

   (8) For integer specifiers (d, u, ld, lu, zd, zu, i, x): the
0-conversion flag has effect even when a precision is given.


File: python.info,  Node: Byte Array Objects,  Next: Unicode Objects and Codecs,  Prev: Bytes Objects,  Up: Sequence Objects

7.9.3.2 Byte Array Objects
..........................

 -- C Tipo: type PyByteArrayObject

     This subtype of *note PyObject: 5df. represents a Python bytearray
     object.

 -- C Variabile: *note PyTypeObject: c9e. PyByteArray_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python bytearray type; it is the
     same object as *note bytearray: 344. in the Python layer.

* Menu:

* Type check macros::
* Direct API functions::
* Macros::


File: python.info,  Node: Type check macros,  Next: Direct API functions,  Up: Byte Array Objects

7.9.3.3 Type check macros
.........................

 -- C Funzione: int PyByteArray_Check (PyObject *o)

     Return true if the object 'o' is a bytearray object or an instance
     of a subtype of the bytearray type.  This function always succeeds.

 -- C Funzione: int PyByteArray_CheckExact (PyObject *o)

     Return true if the object 'o' is a bytearray object, but not an
     instance of a subtype of the bytearray type.  This function always
     succeeds.


File: python.info,  Node: Direct API functions,  Next: Macros,  Prev: Type check macros,  Up: Byte Array Objects

7.9.3.4 Direct API functions
............................

 -- C Funzione: *note PyObject: 5df. *PyByteArray_FromObject (PyObject
          *o)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new bytearray object from any object, 'o',
     that implements the *note buffer protocol: 260.

     On failure, return ‘NULL’ with an exception set.

 -- C Funzione: *note PyObject: 5df. *PyByteArray_FromStringAndSize
          (const char *string, Py_ssize_t len)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a new bytearray object from 'string' and its
     length, 'len'.

     On failure, return ‘NULL’ with an exception set.

 -- C Funzione: *note PyObject: 5df. *PyByteArray_Concat (PyObject *a,
          PyObject *b)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Concat bytearrays 'a' and 'b' and return a new
     bytearray with the result.

     On failure, return ‘NULL’ with an exception set.

 -- C Funzione: *note Py_ssize_t: c57. PyByteArray_Size (PyObject
          *bytearray)
     ' Parte del *note ABI Stabile: 776.'  Return the size of
     'bytearray' after checking for a ‘NULL’ pointer.

 -- C Funzione: char *PyByteArray_AsString (PyObject *bytearray)
     ' Parte del *note ABI Stabile: 776.'  Return the contents of
     'bytearray' as a char array after checking for a ‘NULL’ pointer.
     The returned array always has an extra null byte appended.

 -- C Funzione: int PyByteArray_Resize (PyObject *bytearray, Py_ssize_t
          len)
     ' Parte del *note ABI Stabile: 776.'  Resize the internal buffer of
     'bytearray' to 'len'.  Failure is a ‘-1’ return with an exception
     set.

     Cambiato nella versione 3.14: A negative 'len' will now result in
     an exception being set and -1 returned.


File: python.info,  Node: Macros,  Prev: Direct API functions,  Up: Byte Array Objects

7.9.3.5 Macros
..............

These macros trade safety for speed and they don’t check pointers.

 -- C Funzione: char *PyByteArray_AS_STRING (PyObject *bytearray)

     Similar to *note PyByteArray_AsString(): 4f51, but without error
     checking.

 -- C Funzione: *note Py_ssize_t: c57. PyByteArray_GET_SIZE (PyObject
          *bytearray)

     Similar to *note PyByteArray_Size(): 4f54, but without error
     checking.


File: python.info,  Node: Unicode Objects and Codecs,  Next: Tuple Objects,  Prev: Byte Array Objects,  Up: Sequence Objects

7.9.3.6 Unicode Objects and Codecs
..................................

* Menu:

* Unicode Objects::
* Built-in Codecs::
* Methods and Slot Functions::
* PyUnicodeWriter::
* Deprecated API: Deprecated API<2>.


File: python.info,  Node: Unicode Objects,  Next: Built-in Codecs,  Up: Unicode Objects and Codecs

7.9.3.7 Unicode Objects
.......................

Since the implementation of PEP 393(1) in Python 3.3, Unicode objects
internally use a variety of representations, in order to allow handling
the complete range of Unicode characters while staying memory efficient.
There are special cases for strings where all code points are below 128,
256, or 65536; otherwise, code points must be below 1114112 (which is
the full Unicode range).

UTF-8 representation is created on demand and cached in the Unicode
object.

     Nota: The *note Py_UNICODE: 3e0. representation has been removed
     since Python 3.12 with deprecated APIs.  See PEP 623(2) for more
     information.

* Menu:

* Unicode Type::
* Unicode Character Properties::
* Creating and accessing Unicode strings::
* Locale Encoding::
* File System Encoding::
* wchar_t Support::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0393/

   (2) https://peps.python.org/pep-0623/


File: python.info,  Node: Unicode Type,  Next: Unicode Character Properties,  Up: Unicode Objects

7.9.3.8 Unicode Type
....................

These are the basic Unicode object types used for the Unicode
implementation in Python:

 -- C Variabile: *note PyTypeObject: c9e. PyUnicode_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python Unicode type.  It is
     exposed to Python code as *note str: 169.

 -- C Variabile: *note PyTypeObject: c9e. PyUnicodeIter_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python Unicode iterator type.  It
     is used to iterate over Unicode string objects.

 -- C Tipo: type Py_UCS4
 -- C Tipo: type Py_UCS2
 -- C Tipo: type Py_UCS1
     ' Parte del *note ABI Stabile: 776.'  These types are typedefs for
     unsigned integer types wide enough to contain characters of 32
     bits, 16 bits and 8 bits, respectively.  When dealing with single
     Unicode characters, use *note Py_UCS4: 33d.

     Added in version 3.3.

 -- C Tipo: type PyASCIIObject
 -- C Tipo: type PyCompactUnicodeObject
 -- C Tipo: type PyUnicodeObject

     These subtypes of *note PyObject: 5df. represent a Python Unicode
     object.  In almost all cases, they shouldn’t be used directly,
     since all API functions that deal with Unicode objects take and
     return *note PyObject: 5df. pointers.

     Added in version 3.3.

     The structure of a particular object can be determined using the
     following macros.  The macros cannot fail; their behavior is
     undefined if their argument is not a Python Unicode object.

      -- C Macro: PyUnicode_IS_COMPACT (o)

          True if 'o' uses the *note PyCompactUnicodeObject: 137e.
          structure.

          Added in version 3.3.

      -- C Macro: PyUnicode_IS_COMPACT_ASCII (o)

          True if 'o' uses the *note PyASCIIObject: 137d. structure.

          Added in version 3.3.

The following APIs are C macros and static inlined functions for fast
checks and access to internal read-only data of Unicode objects:

 -- C Funzione: int PyUnicode_Check (PyObject *obj)

     Return true if the object 'obj' is a Unicode object or an instance
     of a Unicode subtype.  This function always succeeds.

 -- C Funzione: int PyUnicode_CheckExact (PyObject *obj)

     Return true if the object 'obj' is a Unicode object, but not an
     instance of a subtype.  This function always succeeds.

 -- C Funzione: *note Py_ssize_t: c57. PyUnicode_GET_LENGTH (PyObject
          *unicode)

     Return the length of the Unicode string, in code points.  'unicode'
     has to be a Unicode object in the «canonical» representation (not
     checked).

     Added in version 3.3.

 -- C Funzione: *note Py_UCS1: 137b. *PyUnicode_1BYTE_DATA (PyObject
          *unicode)
 -- C Funzione: *note Py_UCS2: 137c. *PyUnicode_2BYTE_DATA (PyObject
          *unicode)
 -- C Funzione: *note Py_UCS4: 33d. *PyUnicode_4BYTE_DATA (PyObject
          *unicode)

     Return a pointer to the canonical representation cast to UCS1, UCS2
     or UCS4 integer types for direct character access.  No checks are
     performed if the canonical representation has the correct character
     size; use *note PyUnicode_KIND(): 1385. to select the right
     function.

     Added in version 3.3.

 -- C Macro: PyUnicode_1BYTE_KIND
 -- C Macro: PyUnicode_2BYTE_KIND
 -- C Macro: PyUnicode_4BYTE_KIND

     Return values of the *note PyUnicode_KIND(): 1385. macro.

     Added in version 3.3.

     Cambiato nella versione 3.12: ‘PyUnicode_WCHAR_KIND’ has been
     removed.

 -- C Funzione: int PyUnicode_KIND (PyObject *unicode)

     Return one of the PyUnicode kind constants (see above) that
     indicate how many bytes per character this Unicode object uses to
     store its data.  'unicode' has to be a Unicode object in the
     «canonical» representation (not checked).

     Added in version 3.3.

 -- C Funzione: void *PyUnicode_DATA (PyObject *unicode)

     Return a void pointer to the raw Unicode buffer.  'unicode' has to
     be a Unicode object in the «canonical» representation (not
     checked).

     Added in version 3.3.

 -- C Funzione: void PyUnicode_WRITE (int kind, void *data, Py_ssize_t
          index, Py_UCS4 value)

     Write the code point 'value' to the given zero-based 'index' in a
     string.

     The 'kind' value and 'data' pointer must have been obtained from a
     string using *note PyUnicode_KIND(): 1385. and *note
     PyUnicode_DATA(): 1381. respectively.  You must hold a reference to
     that string while calling ‘PyUnicode_WRITE()’.  All requirements of
     *note PyUnicode_WriteChar(): 137a. also apply.

     The function performs no checks for any of its requirements, and is
     intended for usage in loops.

     Added in version 3.3.

 -- C Funzione: *note Py_UCS4: 33d. PyUnicode_READ (int kind, void
          *data, Py_ssize_t index)

     Read a code point from a canonical representation 'data' (as
     obtained with *note PyUnicode_DATA(): 1381.).  No checks or ready
     calls are performed.

     Added in version 3.3.

 -- C Funzione: *note Py_UCS4: 33d. PyUnicode_READ_CHAR (PyObject
          *unicode, Py_ssize_t index)

     Read a character from a Unicode object 'unicode', which must be in
     the «canonical» representation.  This is less efficient than *note
     PyUnicode_READ(): 1389. if you do multiple consecutive reads.

     Added in version 3.3.

 -- C Funzione: *note Py_UCS4: 33d. PyUnicode_MAX_CHAR_VALUE (PyObject
          *unicode)

     Return the maximum code point that is suitable for creating another
     string based on 'unicode', which must be in the «canonical»
     representation.  This is always an approximation but more efficient
     than iterating over the string.

     Added in version 3.3.

 -- C Funzione: int PyUnicode_IsIdentifier (PyObject *unicode)
     ' Parte del *note ABI Stabile: 776.'  Return ‘1’ if the string is a
     valid identifier according to the language definition, section
     *note Names (identifiers and keywords): 2289.  Return ‘0’
     otherwise.

     Cambiato nella versione 3.9: The function does not call *note
     Py_FatalError(): b7c. anymore if the string is not ready.

 -- C Funzione: unsigned int PyUnicode_IS_ASCII (PyObject *unicode)

     Return true if the string only contains ASCII characters.
     Equivalent to *note str.isascii(): ceb.

     Added in version 3.2.


File: python.info,  Node: Unicode Character Properties,  Next: Creating and accessing Unicode strings,  Prev: Unicode Type,  Up: Unicode Objects

7.9.3.9 Unicode Character Properties
....................................

Unicode provides many different character properties.  The most often
needed ones are available through these macros which are mapped to C
functions depending on the Python configuration.

 -- C Funzione: int Py_UNICODE_ISSPACE (Py_UCS4 ch)

     Return ‘1’ or ‘0’ depending on whether 'ch' is a whitespace
     character.

 -- C Funzione: int Py_UNICODE_ISLOWER (Py_UCS4 ch)

     Return ‘1’ or ‘0’ depending on whether 'ch' is a lowercase
     character.

 -- C Funzione: int Py_UNICODE_ISUPPER (Py_UCS4 ch)

     Return ‘1’ or ‘0’ depending on whether 'ch' is an uppercase
     character.

 -- C Funzione: int Py_UNICODE_ISTITLE (Py_UCS4 ch)

     Return ‘1’ or ‘0’ depending on whether 'ch' is a titlecase
     character.

 -- C Funzione: int Py_UNICODE_ISLINEBREAK (Py_UCS4 ch)

     Return ‘1’ or ‘0’ depending on whether 'ch' is a linebreak
     character.

 -- C Funzione: int Py_UNICODE_ISDECIMAL (Py_UCS4 ch)

     Return ‘1’ or ‘0’ depending on whether 'ch' is a decimal character.

 -- C Funzione: int Py_UNICODE_ISDIGIT (Py_UCS4 ch)

     Return ‘1’ or ‘0’ depending on whether 'ch' is a digit character.

 -- C Funzione: int Py_UNICODE_ISNUMERIC (Py_UCS4 ch)

     Return ‘1’ or ‘0’ depending on whether 'ch' is a numeric character.

 -- C Funzione: int Py_UNICODE_ISALPHA (Py_UCS4 ch)

     Return ‘1’ or ‘0’ depending on whether 'ch' is an alphabetic
     character.

 -- C Funzione: int Py_UNICODE_ISALNUM (Py_UCS4 ch)

     Return ‘1’ or ‘0’ depending on whether 'ch' is an alphanumeric
     character.

 -- C Funzione: int Py_UNICODE_ISPRINTABLE (Py_UCS4 ch)

     Return ‘1’ or ‘0’ depending on whether 'ch' is a printable
     character, in the sense of *note str.isprintable(): fda.

These APIs can be used for fast direct character conversions:

 -- C Funzione: *note Py_UCS4: 33d. Py_UNICODE_TOLOWER (Py_UCS4 ch)

     Return the character 'ch' converted to lower case.

 -- C Funzione: *note Py_UCS4: 33d. Py_UNICODE_TOUPPER (Py_UCS4 ch)

     Return the character 'ch' converted to upper case.

 -- C Funzione: *note Py_UCS4: 33d. Py_UNICODE_TOTITLE (Py_UCS4 ch)

     Return the character 'ch' converted to title case.

 -- C Funzione: int Py_UNICODE_TODECIMAL (Py_UCS4 ch)

     Return the character 'ch' converted to a decimal positive integer.
     Return ‘-1’ if this is not possible.  This function does not raise
     exceptions.

 -- C Funzione: int Py_UNICODE_TODIGIT (Py_UCS4 ch)

     Return the character 'ch' converted to a single digit integer.
     Return ‘-1’ if this is not possible.  This function does not raise
     exceptions.

 -- C Funzione: double Py_UNICODE_TONUMERIC (Py_UCS4 ch)

     Return the character 'ch' converted to a double.  Return ‘-1.0’ if
     this is not possible.  This function does not raise exceptions.

These APIs can be used to work with surrogates:

 -- C Funzione: int Py_UNICODE_IS_SURROGATE (Py_UCS4 ch)

     Check if 'ch' is a surrogate (‘0xD800 <= ch <= 0xDFFF’).

 -- C Funzione: int Py_UNICODE_IS_HIGH_SURROGATE (Py_UCS4 ch)

     Check if 'ch' is a high surrogate (‘0xD800 <= ch <= 0xDBFF’).

 -- C Funzione: int Py_UNICODE_IS_LOW_SURROGATE (Py_UCS4 ch)

     Check if 'ch' is a low surrogate (‘0xDC00 <= ch <= 0xDFFF’).

 -- C Funzione: *note Py_UCS4: 33d. Py_UNICODE_HIGH_SURROGATE (Py_UCS4
          ch)

     Return the high UTF-16 surrogate (‘0xD800’ to ‘0xDBFF’) for a
     Unicode code point in the range ‘[0x10000; 0x10FFFF]’.

 -- C Funzione: *note Py_UCS4: 33d. Py_UNICODE_LOW_SURROGATE (Py_UCS4
          ch)

     Return the low UTF-16 surrogate (‘0xDC00’ to ‘0xDFFF’) for a
     Unicode code point in the range ‘[0x10000; 0x10FFFF]’.

 -- C Funzione: *note Py_UCS4: 33d. Py_UNICODE_JOIN_SURROGATES (Py_UCS4
          high, Py_UCS4 low)

     Join two surrogate code points and return a single *note Py_UCS4:
     33d. value.  'high' and 'low' are respectively the leading and
     trailing surrogates in a surrogate pair.  'high' must be in the
     range ‘[0xD800; 0xDBFF]’ and 'low' must be in the range ‘[0xDC00;
     0xDFFF]’.


File: python.info,  Node: Creating and accessing Unicode strings,  Next: Locale Encoding,  Prev: Unicode Character Properties,  Up: Unicode Objects

7.9.3.10 Creating and accessing Unicode strings
...............................................

To create Unicode objects and access their basic sequence properties,
use these APIs:

 -- C Funzione: *note PyObject: 5df. *PyUnicode_New (Py_ssize_t size,
          Py_UCS4 maxchar)
     'Valore di ritorno: Nuovo riferimento.'  Create a new Unicode
     object.  'maxchar' should be the true maximum code point to be
     placed in the string.  As an approximation, it can be rounded up to
     the nearest value in the sequence 127, 255, 65535, 1114111.

     On error, set an exception and return ‘NULL’.

     After creation, the string can be filled by *note
     PyUnicode_WriteChar(): 137a, *note PyUnicode_CopyCharacters(): ab4,
     *note PyUnicode_Fill(): 1395, *note PyUnicode_WRITE(): 138b. or
     similar.  Since strings are supposed to be immutable, take care to
     not “use” the result while it is being modified.  In particular,
     before it’s filled with its final contents, a string:

        - must not be hashed,

        - must not be *note converted to UTF-8: a9b, or another
          non-«canonical» representation,

        - must not have its reference count changed,

        - must not be shared with code that might do one of the above.

     This list is not exhaustive.  Avoiding these uses is your
     responsibility; Python does not always check these requirements.

     To avoid accidentally exposing a partially-written string object,
     prefer using the *note PyUnicodeWriter: 3b3. API, or one of the
     ‘PyUnicode_From*’ functions below.

     Added in version 3.3.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_FromKindAndData (int
          kind, const void *buffer, Py_ssize_t size)
     'Valore di ritorno: Nuovo riferimento.'  Create a new Unicode
     object with the given 'kind' (possible values are *note
     PyUnicode_1BYTE_KIND: 1386. etc., as returned by *note
     PyUnicode_KIND(): 1385.).  The 'buffer' must point to an array of
     'size' units of 1, 2 or 4 bytes per character, as given by the
     kind.

     If necessary, the input 'buffer' is copied and transformed into the
     canonical representation.  For example, if the 'buffer' is a UCS4
     string (*note PyUnicode_4BYTE_KIND: 1388.) and it consists only of
     codepoints in the UCS1 range, it will be transformed into UCS1
     (*note PyUnicode_1BYTE_KIND: 1386.).

     Added in version 3.3.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_FromStringAndSize (const
          char *str, Py_ssize_t size)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode object from the char buffer 'str'.
     The bytes will be interpreted as being UTF-8 encoded.  The buffer
     is copied into the new object.  The return value might be a shared
     object, i.e.  modification of the data is not allowed.

     This function raises *note SystemError: 796. when:

        * 'size' < 0,

        * 'str' is ‘NULL’ and 'size' > 0

     Cambiato nella versione 3.12: 'str' == ‘NULL’ with 'size' > 0 is
     not allowed anymore.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_FromString (const char
          *str)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode object from a UTF-8 encoded
     null-terminated char buffer 'str'.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_FromFormat (const char
          *format, ...)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Take a C ‘printf()’-style 'format' string and a
     variable number of arguments, calculate the size of the resulting
     Python Unicode string and return a string with the values formatted
     into it.  The variable arguments must be C types and must
     correspond exactly to the format characters in the 'format'
     ASCII-encoded string.

     A conversion specifier contains two or more characters and has the
     following components, which must occur in this order:

       1. The ‘'%'’ character, which marks the start of the specifier.

       2. Conversion flags (optional), which affect the result of some
          conversion types.

       3. Minimum field width (optional).  If specified as an ‘'*'’
          (asterisk), the actual width is given in the next argument,
          which must be of type int, and the object to convert comes
          after the minimum field width and optional precision.

       4. Precision (optional), given as a ‘'.'’ (dot) followed by the
          precision.  If specified as ‘'*'’ (an asterisk), the actual
          precision is given in the next argument, which must be of type
          int, and the value to convert comes after the precision.

       5. Length modifier (optional).

       6. Conversion type.

     The conversion flag characters are:

     Flag        Meaning
                 
     ------------------------------------------------------------------------------
                 
     ‘0’         The conversion will be zero padded for numeric values.
                 
                 
     ‘-’         The converted value is left adjusted (overrides the ‘0’ flag if
                 both are given).
                 

     The length modifiers for following integer conversions (‘d’, ‘i’,
     ‘o’, ‘u’, ‘x’, or ‘X’) specify the type of the argument (int by
     default):

     Modifier       Types
                    
     -------------------------------------------------------------------------
                    
     ‘l’            long or unsigned long
                    
                    
     ‘ll’           long long or unsigned long long
                    
                    
     ‘j’            ‘intmax_t’ or ‘uintmax_t’
                    
                    
     ‘z’            ‘size_t’ or ‘ssize_t’
                    
                    
     ‘t’            ‘ptrdiff_t’
                    

     The length modifier ‘l’ for following conversions ‘s’ or ‘V’
     specify that the type of the argument is const wchar_t*.

     The conversion specifiers are:

     Conversion Specifier                  Type                                  Comment
                                                                                 
     ------------------------------------------------------------------------------------------------------------------
                                                                                 
     ‘%’                                   'n/a'                                 The literal ‘%’ character.
                                                                                 
                                                                                 
     ‘d’, ‘i’                              Specified by the length modifier      The decimal representation of a
                                                                                 signed C integer.
                                                                                 
                                                                                 
     ‘u’                                   Specified by the length modifier      The decimal representation of an
                                                                                 unsigned C integer.
                                                                                 
                                                                                 
     ‘o’                                   Specified by the length modifier      The octal representation of an
                                                                                 unsigned C integer.
                                                                                 
                                                                                 
     ‘x’                                   Specified by the length modifier      The hexadecimal representation of
                                                                                 an unsigned C integer (lowercase).
                                                                                 
                                                                                 
     ‘X’                                   Specified by the length modifier      The hexadecimal representation of
                                                                                 an unsigned C integer (uppercase).
                                                                                 
                                                                                 
     ‘c’                                   int                                   A single character.
                                                                                 
                                                                                 
     ‘s’                                   const char* or const wchar_t*         A null-terminated C character
                                                                                 array.
                                                                                 
                                                                                 
     ‘p’                                   const void*                           The hex representation of a C
                                                                                 pointer.  Mostly equivalent to
                                                                                 ‘printf("%p")’ except that it is
                                                                                 guaranteed to start with the
                                                                                 literal ‘0x’ regardless of what the
                                                                                 platform’s ‘printf’ yields.
                                                                                 
                                                                                 
     ‘A’                                   *note PyObject: 5df.*                 The result of calling
                                                                                 *note ascii(): 15ed.
                                                                                 
                                                                                 
     ‘U’                                   *note PyObject: 5df.*                 A Unicode object.
                                                                                 
                                                                                 
     ‘V’                                   *note PyObject: 5df.*, const char*    A Unicode object (which may be
                                           or const wchar_t*                     ‘NULL’) and a null-terminated C
                                                                                 character array as a second
                                                                                 parameter (which will be used, if
                                                                                 the first parameter is ‘NULL’).
                                                                                 
                                                                                 
     ‘S’                                   *note PyObject: 5df.*                 The result of calling
                                                                                 *note PyObject_Str(): 1232.
                                                                                 
                                                                                 
     ‘R’                                   *note PyObject: 5df.*                 The result of calling
                                                                                 *note PyObject_Repr(): 1231.
                                                                                 
                                                                                 
     ‘T’                                   *note PyObject: 5df.*                 Get the fully qualified name of an
                                                                                 object type; call
                                                                                 *note PyType_GetFullyQualifiedName(): 616.
                                                                                 
                                                                                 
     ‘#T’                                  *note PyObject: 5df.*                 Similar to ‘T’ format, but use a
                                                                                 colon (‘:’) as separator between
                                                                                 the module name and the qualified
                                                                                 name.
                                                                                 
                                                                                 
     ‘N’                                   *note PyTypeObject: c9e.*             Get the fully qualified name of a
                                                                                 type; call
                                                                                 *note PyType_GetFullyQualifiedName(): 616.
                                                                                 
                                                                                 
     ‘#N’                                  *note PyTypeObject: c9e.*             Similar to ‘N’ format, but use a
                                                                                 colon (‘:’) as separator between
                                                                                 the module name and the qualified
                                                                                 name.
                                                                                 

          Nota: The width formatter unit is number of characters rather
          than bytes.  The precision formatter unit is number of bytes
          or ‘wchar_t’ items (if the length modifier ‘l’ is used) for
          ‘"%s"’ and ‘"%V"’ (if the ‘PyObject*’ argument is ‘NULL’), and
          a number of characters for ‘"%A"’, ‘"%U"’, ‘"%S"’, ‘"%R"’ and
          ‘"%V"’ (if the ‘PyObject*’ argument is not ‘NULL’).

          Nota: Unlike to C ‘printf()’ the ‘0’ flag has effect even when
          a precision is given for integer conversions (‘d’, ‘i’, ‘u’,
          ‘o’, ‘x’, or ‘X’).

     Cambiato nella versione 3.2: Support for ‘"%lld"’ and ‘"%llu"’
     added.

     Cambiato nella versione 3.3: Support for ‘"%li"’, ‘"%lli"’ and
     ‘"%zi"’ added.

     Cambiato nella versione 3.4: Support width and precision formatter
     for ‘"%s"’, ‘"%A"’, ‘"%U"’, ‘"%V"’, ‘"%S"’, ‘"%R"’ added.

     Cambiato nella versione 3.12: Support for conversion specifiers ‘o’
     and ‘X’.  Support for length modifiers ‘j’ and ‘t’.  Length
     modifiers are now applied to all integer conversions.  Length
     modifier ‘l’ is now applied to conversion specifiers ‘s’ and ‘V’.
     Support for variable width and precision ‘*’.  Support for flag
     ‘-’.

     An unrecognized format character now sets a *note SystemError: 796.
     In previous versions it caused all the rest of the format string to
     be copied as-is to the result string, and any extra arguments
     discarded.

     Cambiato nella versione 3.13: Support for ‘%T’, ‘%#T’, ‘%N’ and
     ‘%#N’ formats added.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_FromFormatV (const char
          *format, va_list vargs)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Identical to *note PyUnicode_FromFormat(): 62b.
     except that it takes exactly two arguments.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_FromObject (PyObject
          *obj)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Copy an instance of a Unicode subtype to a new true
     Unicode object if necessary.  If 'obj' is already a true Unicode
     object (not a subtype), return a new *note strong reference: 5e2.
     to the object.

     Objects other than Unicode or its subtypes will cause a *note
     TypeError: 198.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_FromOrdinal (int
          ordinal)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode Object from the given Unicode code
     point 'ordinal'.

     The ordinal must be in ‘range(0x110000)’.  A *note ValueError: 2ec.
     is raised in the case it is not.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_FromEncodedObject
          (PyObject *obj, const char *encoding, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Decode an encoded object 'obj' to a Unicode object.

     *note bytes: 192, *note bytearray: 344. and other *note bytes-like
     objects: 193. are decoded according to the given 'encoding' and
     using the error handling defined by 'errors'.  Both can be ‘NULL’
     to have the interface use the default values (see *note Built-in
     Codecs: 534e. for details).

     All other objects, including Unicode objects, cause a *note
     TypeError: 198. to be set.

     The API returns ‘NULL’ if there was an error.  The caller is
     responsible for decref’ing the returned objects.

 -- C Funzione: void PyUnicode_Append (PyObject **p_left, PyObject
          *right)
     ' Parte del *note ABI Stabile: 776.'  Append the string 'right' to
     the end of 'p_left'.  'p_left' must point to a *note strong
     reference: 5e2. to a Unicode object; ‘PyUnicode_Append()’ releases
     («steals») this reference.

     On error, set '*p_left' to ‘NULL’ and set an exception.

     On success, set '*p_left' to a new strong reference to the result.

 -- C Funzione: void PyUnicode_AppendAndDel (PyObject **p_left, PyObject
          *right)
     ' Parte del *note ABI Stabile: 776.'  The function is similar to
     *note PyUnicode_Append(): 50cc, with the only difference being that
     it decrements the reference count of 'right' by one.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_BuildEncodingMap
          (PyObject *string)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a mapping suitable for decoding a custom
     single-byte encoding.  Given a Unicode string 'string' of up to 256
     characters representing an encoding table, returns either a compact
     internal mapping object or a dictionary mapping character ordinals
     to byte values.  Raises a *note TypeError: 198. and return ‘NULL’
     on invalid input.

     Added in version 3.2.

 -- C Funzione: const char *PyUnicode_GetDefaultEncoding (void)
     ' Parte del *note ABI Stabile: 776.'  Return the name of the
     default string encoding, ‘"utf-8"’.  See *note
     sys.getdefaultencoding(): 48fe.

     The returned string does not need to be freed, and is valid until
     interpreter shutdown.

 -- C Funzione: *note Py_ssize_t: c57. PyUnicode_GetLength (PyObject
          *unicode)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Return
     the length of the Unicode object, in code points.

     On error, set an exception and return ‘-1’.

     Added in version 3.3.

 -- C Funzione: *note Py_ssize_t: c57. PyUnicode_CopyCharacters
          (PyObject *to, Py_ssize_t to_start, PyObject *from, Py_ssize_t
          from_start, Py_ssize_t how_many)

     Copy characters from one Unicode object into another.  This
     function performs character conversion when necessary and falls
     back to ‘memcpy()’ if possible.  Returns ‘-1’ and sets an exception
     on error, otherwise returns the number of copied characters.

     The string must not have been “used” yet.  See *note
     PyUnicode_New(): aab. for details.

     Added in version 3.3.

 -- C Funzione: int PyUnicode_Resize (PyObject **unicode, Py_ssize_t
          length);
     ' Parte del *note ABI Stabile: 776.'  Resize a Unicode object
     '*unicode' to the new 'length' in code points.

     Try to resize the string in place (which is usually faster than
     allocating a new string and copying characters), or create a new
     string.

     '*unicode' is modified to point to the new (resized) object and ‘0’
     is returned on success.  Otherwise, ‘-1’ is returned and an
     exception is set, and '*unicode' is left untouched.

     The function doesn’t check string content, the result may not be a
     string in canonical representation.

 -- C Funzione: *note Py_ssize_t: c57. PyUnicode_Fill (PyObject
          *unicode, Py_ssize_t start, Py_ssize_t length, Py_UCS4
          fill_char)

     Fill a string with a character: write 'fill_char' into
     ‘unicode[start:start+length]’.

     Fail if 'fill_char' is bigger than the string maximum character, or
     if the string has more than 1 reference.

     The string must not have been “used” yet.  See *note
     PyUnicode_New(): aab. for details.

     Return the number of written character, or return ‘-1’ and raise an
     exception on error.

     Added in version 3.3.

 -- C Funzione: int PyUnicode_WriteChar (PyObject *unicode, Py_ssize_t
          index, Py_UCS4 character)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Write a
     'character' to the string 'unicode' at the zero-based 'index'.
     Return ‘0’ on success, ‘-1’ on error with an exception set.

     This function checks that 'unicode' is a Unicode object, that the
     index is not out of bounds, and that the object’s reference count
     is one.  See *note PyUnicode_WRITE(): 138b. for a version that
     skips these checks, making them your responsibility.

     The string must not have been “used” yet.  See *note
     PyUnicode_New(): aab. for details.

     Added in version 3.3.

 -- C Funzione: *note Py_UCS4: 33d. PyUnicode_ReadChar (PyObject
          *unicode, Py_ssize_t index)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Read a
     character from a string.  This function checks that 'unicode' is a
     Unicode object and the index is not out of bounds, in contrast to
     *note PyUnicode_READ_CHAR(): 138a, which performs no error
     checking.

     Return character on success, ‘-1’ on error with an exception set.

     Added in version 3.3.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_Substring (PyObject
          *unicode, Py_ssize_t start, Py_ssize_t end)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'  Return a substring of
     'unicode', from character index 'start' (included) to character
     index 'end' (excluded).  Negative indices are not supported.  On
     error, set an exception and return ‘NULL’.

     Added in version 3.3.

 -- C Funzione: *note Py_UCS4: 33d. *PyUnicode_AsUCS4 (PyObject
          *unicode, Py_UCS4 *buffer, Py_ssize_t buflen, int copy_null)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Copy the
     string 'unicode' into a UCS4 buffer, including a null character, if
     'copy_null' is set.  Returns ‘NULL’ and sets an exception on error
     (in particular, a *note SystemError: 796. if 'buflen' is smaller
     than the length of 'unicode').  'buffer' is returned on success.

     Added in version 3.3.

 -- C Funzione: *note Py_UCS4: 33d. *PyUnicode_AsUCS4Copy (PyObject
          *unicode)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Copy the
     string 'unicode' into a new UCS4 buffer that is allocated using
     *note PyMem_Malloc(): e62.  If this fails, ‘NULL’ is returned with
     a *note MemoryError: 1786. set.  The returned buffer always has an
     extra null code point appended.

     Added in version 3.3.


File: python.info,  Node: Locale Encoding,  Next: File System Encoding,  Prev: Creating and accessing Unicode strings,  Up: Unicode Objects

7.9.3.11 Locale Encoding
........................

The current locale encoding can be used to decode text from the
operating system.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeLocaleAndSize
          (const char *str, Py_ssize_t length, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'  Decode a string from UTF-8 on
     Android and VxWorks, or from the current locale encoding on other
     platforms.  The supported error handlers are ‘"strict"’ and
     ‘"surrogateescape"’ ( PEP 383(1)).  The decoder uses ‘"strict"’
     error handler if 'errors' is ‘NULL’.  'str' must end with a null
     character but cannot contain embedded null characters.

     Use *note PyUnicode_DecodeFSDefaultAndSize(): 50d7. to decode a
     string from the *note filesystem encoding and error handler: 75e.

     This function ignores the *note Python UTF-8 Mode: 867.

     Vedi anche
     ..........

     The *note Py_DecodeLocale(): dc2. function.

     Added in version 3.3.

     Cambiato nella versione 3.7: The function now also uses the current
     locale encoding for the ‘surrogateescape’ error handler, except on
     Android.  Previously, *note Py_DecodeLocale(): dc2. was used for
     the ‘surrogateescape’, and the current locale encoding was used for
     ‘strict’.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeLocale (const char
          *str, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'  Similar to *note
     PyUnicode_DecodeLocaleAndSize(): dc4, but compute the string length
     using ‘strlen()’.

     Added in version 3.3.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_EncodeLocale (PyObject
          *unicode, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'  Encode a Unicode object to
     UTF-8 on Android and VxWorks, or to the current locale encoding on
     other platforms.  The supported error handlers are ‘"strict"’ and
     ‘"surrogateescape"’ ( PEP 383(2)).  The encoder uses ‘"strict"’
     error handler if 'errors' is ‘NULL’.  Return a *note bytes: 192.
     object.  'unicode' cannot contain embedded null characters.

     Use *note PyUnicode_EncodeFSDefault(): 1e19. to encode a string to
     the *note filesystem encoding and error handler: 75e.

     This function ignores the *note Python UTF-8 Mode: 867.

     Vedi anche
     ..........

     The *note Py_EncodeLocale(): dc3. function.

     Added in version 3.3.

     Cambiato nella versione 3.7: The function now also uses the current
     locale encoding for the ‘surrogateescape’ error handler, except on
     Android.  Previously, *note Py_EncodeLocale(): dc3. was used for
     the ‘surrogateescape’, and the current locale encoding was used for
     ‘strict’.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0383/

   (2) https://peps.python.org/pep-0383/


File: python.info,  Node: File System Encoding,  Next: wchar_t Support,  Prev: Locale Encoding,  Up: Unicode Objects

7.9.3.12 File System Encoding
.............................

Functions encoding to and decoding from the *note filesystem encoding
and error handler: 75e. ( PEP 383(1) and PEP 529(2)).

To encode file names to *note bytes: 192. during argument parsing, the
‘"O&"’ converter should be used, passing ‘PyUnicode_FSConverter()’ as
the conversion function:

 -- C Funzione: int PyUnicode_FSConverter (PyObject *obj, void *result)
     ' Parte del *note ABI Stabile: 776.'  *note PyArg_Parse* converter:
     3d5.: encode *note str: 169. objects – obtained directly or through
     the *note os.PathLike: e4d. interface – to *note bytes: 192. using
     *note PyUnicode_EncodeFSDefault(): 1e19.; *note bytes: 192. objects
     are output as-is.  'result' must be an address of a C variable of
     type *note PyObject: 5df.* (or *note PyBytesObject: 996.*).  On
     success, set the variable to a new *note strong reference: 5e2. to
     a *note bytes object: 531c. which must be released when it is no
     longer used and return a non-zero value (*note
     Py_CLEANUP_SUPPORTED: 5218.).  Embedded null bytes are not allowed
     in the result.  On failure, return ‘0’ with an exception set.

     If 'obj' is ‘NULL’, the function releases a strong reference stored
     in the variable referred by 'result' and returns ‘1’.

     Added in version 3.1.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

To decode file names to *note str: 169. during argument parsing, the
‘"O&"’ converter should be used, passing ‘PyUnicode_FSDecoder()’ as the
conversion function:

 -- C Funzione: int PyUnicode_FSDecoder (PyObject *obj, void *result)
     ' Parte del *note ABI Stabile: 776.'  *note PyArg_Parse* converter:
     3d5.: decode *note bytes: 192. objects – obtained either directly
     or indirectly through the *note os.PathLike: e4d. interface – to
     *note str: 169. using *note PyUnicode_DecodeFSDefaultAndSize():
     50d7.; *note str: 169. objects are output as-is.  'result' must be
     an address of a C variable of type *note PyObject: 5df.* (or *note
     PyUnicodeObject: 998.*).  On success, set the variable to a new
     *note strong reference: 5e2. to a *note Unicode object: 532e. which
     must be released when it is no longer used and return a non-zero
     value (*note Py_CLEANUP_SUPPORTED: 5218.).  Embedded null
     characters are not allowed in the result.  On failure, return ‘0’
     with an exception set.

     If 'obj' is ‘NULL’, release the strong reference to the object
     referred to by 'result' and return ‘1’.

     Added in version 3.2.

     Cambiato nella versione 3.6: Accepts a *note path-like object: 5a1.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeFSDefaultAndSize
          (const char *str, Py_ssize_t size)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Decode a string from the *note filesystem encoding
     and error handler: 75e.

     If you need to decode a string from the current locale encoding,
     use *note PyUnicode_DecodeLocaleAndSize(): dc4.

     Vedi anche
     ..........

     The *note Py_DecodeLocale(): dc2. function.

     Cambiato nella versione 3.6: The *note filesystem error handler:
     75e. is now used.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeFSDefault (const
          char *str)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Decode a null-terminated string from the *note
     filesystem encoding and error handler: 75e.

     If the string length is known, use *note
     PyUnicode_DecodeFSDefaultAndSize(): 50d7.

     Cambiato nella versione 3.6: The *note filesystem error handler:
     75e. is now used.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_EncodeFSDefault
          (PyObject *unicode)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Encode a Unicode object to the *note filesystem
     encoding and error handler: 75e, and return *note bytes: 192.  Note
     that the resulting *note bytes: 192. object can contain null bytes.

     If you need to encode a string to the current locale encoding, use
     *note PyUnicode_EncodeLocale(): dc5.

     Vedi anche
     ..........

     The *note Py_EncodeLocale(): dc3. function.

     Added in version 3.2.

     Cambiato nella versione 3.6: The *note filesystem error handler:
     75e. is now used.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0383/

   (2) https://peps.python.org/pep-0529/


File: python.info,  Node: wchar_t Support,  Prev: File System Encoding,  Up: Unicode Objects

7.9.3.13 wchar_t Support
........................

‘wchar_t’ support for platforms which support it:

 -- C Funzione: *note PyObject: 5df. *PyUnicode_FromWideChar (const
          wchar_t *wstr, Py_ssize_t size)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode object from the ‘wchar_t’ buffer
     'wstr' of the given 'size'.  Passing ‘-1’ as the 'size' indicates
     that the function must itself compute the length, using ‘wcslen()’.
     Return ‘NULL’ on failure.

 -- C Funzione: *note Py_ssize_t: c57. PyUnicode_AsWideChar (PyObject
          *unicode, wchar_t *wstr, Py_ssize_t size)
     ' Parte del *note ABI Stabile: 776.'  Copy the Unicode object
     contents into the ‘wchar_t’ buffer 'wstr'.  At most 'size'
     ‘wchar_t’ characters are copied (excluding a possibly trailing null
     termination character).  Return the number of ‘wchar_t’ characters
     copied or ‘-1’ in case of an error.

     When 'wstr' is ‘NULL’, instead return the 'size' that would be
     required to store all of 'unicode' including a terminating null.

     Note that the resulting wchar_t* string may or may not be
     null-terminated.  It is the responsibility of the caller to make
     sure that the wchar_t* string is null-terminated in case this is
     required by the application.  Also, note that the wchar_t* string
     might contain null characters, which would cause the string to be
     truncated when used with most C functions.

 -- C Funzione: wchar_t *PyUnicode_AsWideCharString (PyObject *unicode,
          Py_ssize_t *size)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Convert
     the Unicode object to a wide character string.  The output string
     always ends with a null character.  If 'size' is not ‘NULL’, write
     the number of wide characters (excluding the trailing null
     termination character) into '*size'.  Note that the resulting
     ‘wchar_t’ string might contain null characters, which would cause
     the string to be truncated when used with most C functions.  If
     'size' is ‘NULL’ and the wchar_t* string contains null characters a
     *note ValueError: 2ec. is raised.

     Returns a buffer allocated by *note PyMem_New: 172b. (use *note
     PyMem_Free(): 1649. to free it) on success.  On error, returns
     ‘NULL’ and '*size' is undefined.  Raises a *note MemoryError: 1786.
     if memory allocation is failed.

     Added in version 3.2.

     Cambiato nella versione 3.7: Raises a *note ValueError: 2ec. if
     'size' is ‘NULL’ and the wchar_t* string contains null characters.


File: python.info,  Node: Built-in Codecs,  Next: Methods and Slot Functions,  Prev: Unicode Objects,  Up: Unicode Objects and Codecs

7.9.3.14 Built-in Codecs
........................

Python provides a set of built-in codecs which are written in C for
speed.  All of these codecs are directly usable via the following
functions.

Many of the following APIs take two arguments encoding and errors, and
they have the same semantics as the ones of the built-in *note str():
169. string object constructor.

Setting encoding to ‘NULL’ causes the default encoding to be used which
is UTF-8.  The file system calls should use *note
PyUnicode_FSConverter(): f17. for encoding file names.  This uses the
*note filesystem encoding and error handler: 75e. internally.

Error handling is set by errors which may also be set to ‘NULL’ meaning
to use the default handling defined for the codec.  Default error
handling for all built-in codecs is «strict» (*note ValueError: 2ec. is
raised).

The codecs all use a similar interface.  Only deviations from the
following generic ones are documented for simplicity.

* Menu:

* Generic Codecs::
* UTF-8 Codecs::
* UTF-32 Codecs::
* UTF-16 Codecs::
* UTF-7 Codecs::
* Unicode-Escape Codecs::
* Raw-Unicode-Escape Codecs::
* Latin-1 Codecs::
* ASCII Codecs::
* Character Map Codecs::
* MBCS codecs for Windows::


File: python.info,  Node: Generic Codecs,  Next: UTF-8 Codecs,  Up: Built-in Codecs

7.9.3.15 Generic Codecs
.......................

The following macro is provided:

 -- C Macro: Py_UNICODE_REPLACEMENT_CHARACTER

     The Unicode code point ‘U+FFFD’ (replacement character).

     This Unicode character is used as the replacement character during
     decoding if the 'errors' argument is set to «replace».

These are the generic codec APIs:

 -- C Funzione: *note PyObject: 5df. *PyUnicode_Decode (const char *str,
          Py_ssize_t size, const char *encoding, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode object by decoding 'size' bytes of
     the encoded string 'str'.  'encoding' and 'errors' have the same
     meaning as the parameters of the same name in the *note str(): 169.
     built-in function.  The codec to be used is looked up using the
     Python codec registry.  Return ‘NULL’ if an exception was raised by
     the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_AsEncodedString
          (PyObject *unicode, const char *encoding, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Encode a Unicode object and return the result as
     Python bytes object.  'encoding' and 'errors' have the same meaning
     as the parameters of the same name in the Unicode *note encode():
     ad4. method.  The codec to be used is looked up using the Python
     codec registry.  Return ‘NULL’ if an exception was raised by the
     codec.


File: python.info,  Node: UTF-8 Codecs,  Next: UTF-32 Codecs,  Prev: Generic Codecs,  Up: Built-in Codecs

7.9.3.16 UTF-8 Codecs
.....................

These are the UTF-8 codec APIs:

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeUTF8 (const char
          *str, Py_ssize_t size, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode object by decoding 'size' bytes of
     the UTF-8 encoded string 'str'.  Return ‘NULL’ if an exception was
     raised by the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeUTF8Stateful
          (const char *str, Py_ssize_t size, const char *errors,
          Py_ssize_t *consumed)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  If 'consumed' is ‘NULL’, behave like *note
     PyUnicode_DecodeUTF8(): 50e3.  If 'consumed' is not ‘NULL’,
     trailing incomplete UTF-8 byte sequences will not be treated as an
     error.  Those bytes will not be decoded and the number of bytes
     that have been decoded will be stored in 'consumed'.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_AsUTF8String (PyObject
          *unicode)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Encode a Unicode object using UTF-8 and return the
     result as Python bytes object.  Error handling is «strict».  Return
     ‘NULL’ if an exception was raised by the codec.

     The function fails if the string contains surrogate code points
     (‘U+D800’ - ‘U+DFFF’).

 -- C Funzione: const char *PyUnicode_AsUTF8AndSize (PyObject *unicode,
          Py_ssize_t *size)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Return a
     pointer to the UTF-8 encoding of the Unicode object, and store the
     size of the encoded representation (in bytes) in 'size'.  The
     'size' argument can be ‘NULL’; in this case no size will be stored.
     The returned buffer always has an extra null byte appended (not
     included in 'size'), regardless of whether there are any other null
     code points.

     On error, set an exception, set 'size' to ‘-1’ (if it’s not NULL)
     and return ‘NULL’.

     The function fails if the string contains surrogate code points
     (‘U+D800’ - ‘U+DFFF’).

     This caches the UTF-8 representation of the string in the Unicode
     object, and subsequent calls will return a pointer to the same
     buffer.  The caller is not responsible for deallocating the buffer.
     The buffer is deallocated and pointers to it become invalid when
     the Unicode object is garbage collected.

     Added in version 3.3.

     Cambiato nella versione 3.7: The return type is now ‘const char *’
     rather of ‘char *’.

     Cambiato nella versione 3.10: This function is a part of the *note
     limited API: 637.

 -- C Funzione: const char *PyUnicode_AsUTF8 (PyObject *unicode)

     As *note PyUnicode_AsUTF8AndSize(): a9b, but does not store the
     size.

          Avvertimento: This function does not have any special behavior
          for null characters(1) embedded within 'unicode'.  As a
          result, strings containing null characters will remain in the
          returned string, which some C functions might interpret as the
          end of the string, leading to truncation.  If truncation is an
          issue, it is recommended to use *note
          PyUnicode_AsUTF8AndSize(): a9b. instead.

     Added in version 3.3.

     Cambiato nella versione 3.7: The return type is now ‘const char *’
     rather of ‘char *’.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Null_character


File: python.info,  Node: UTF-32 Codecs,  Next: UTF-16 Codecs,  Prev: UTF-8 Codecs,  Up: Built-in Codecs

7.9.3.17 UTF-32 Codecs
......................

These are the UTF-32 codec APIs:

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeUTF32 (const char
          *str, Py_ssize_t size, const char *errors, int *byteorder)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Decode 'size' bytes from a UTF-32 encoded buffer
     string and return the corresponding Unicode object.  'errors' (if
     non-‘NULL’) defines the error handling.  It defaults to «strict».

     If 'byteorder' is non-‘NULL’, the decoder starts decoding using the
     given byte order:

          *byteorder == -1: little endian
          *byteorder == 0:  native order
          *byteorder == 1:  big endian

     If ‘*byteorder’ is zero, and the first four bytes of the input data
     are a byte order mark (BOM), the decoder switches to this byte
     order and the BOM is not copied into the resulting Unicode string.
     If ‘*byteorder’ is ‘-1’ or ‘1’, any byte order mark is copied to
     the output.

     After completion, '*byteorder' is set to the current byte order at
     the end of input data.

     If 'byteorder' is ‘NULL’, the codec starts in native order mode.

     Return ‘NULL’ if an exception was raised by the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeUTF32Stateful
          (const char *str, Py_ssize_t size, const char *errors, int
          *byteorder, Py_ssize_t *consumed)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  If 'consumed' is ‘NULL’, behave like *note
     PyUnicode_DecodeUTF32(): 50df.  If 'consumed' is not ‘NULL’, *note
     PyUnicode_DecodeUTF32Stateful(): 50e0. will not treat trailing
     incomplete UTF-32 byte sequences (such as a number of bytes not
     divisible by four) as an error.  Those bytes will not be decoded
     and the number of bytes that have been decoded will be stored in
     'consumed'.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_AsUTF32String (PyObject
          *unicode)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a Python byte string using the UTF-32
     encoding in native byte order.  The string always starts with a BOM
     mark.  Error handling is «strict».  Return ‘NULL’ if an exception
     was raised by the codec.


File: python.info,  Node: UTF-16 Codecs,  Next: UTF-7 Codecs,  Prev: UTF-32 Codecs,  Up: Built-in Codecs

7.9.3.18 UTF-16 Codecs
......................

These are the UTF-16 codec APIs:

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeUTF16 (const char
          *str, Py_ssize_t size, const char *errors, int *byteorder)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Decode 'size' bytes from a UTF-16 encoded buffer
     string and return the corresponding Unicode object.  'errors' (if
     non-‘NULL’) defines the error handling.  It defaults to «strict».

     If 'byteorder' is non-‘NULL’, the decoder starts decoding using the
     given byte order:

          *byteorder == -1: little endian
          *byteorder == 0:  native order
          *byteorder == 1:  big endian

     If ‘*byteorder’ is zero, and the first two bytes of the input data
     are a byte order mark (BOM), the decoder switches to this byte
     order and the BOM is not copied into the resulting Unicode string.
     If ‘*byteorder’ is ‘-1’ or ‘1’, any byte order mark is copied to
     the output (where it will result in either a ‘\ufeff’ or a ‘\ufffe’
     character).

     After completion, ‘*byteorder’ is set to the current byte order at
     the end of input data.

     If 'byteorder' is ‘NULL’, the codec starts in native order mode.

     Return ‘NULL’ if an exception was raised by the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeUTF16Stateful
          (const char *str, Py_ssize_t size, const char *errors, int
          *byteorder, Py_ssize_t *consumed)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  If 'consumed' is ‘NULL’, behave like *note
     PyUnicode_DecodeUTF16(): 50dd.  If 'consumed' is not ‘NULL’, *note
     PyUnicode_DecodeUTF16Stateful(): 50de. will not treat trailing
     incomplete UTF-16 byte sequences (such as an odd number of bytes or
     a split surrogate pair) as an error.  Those bytes will not be
     decoded and the number of bytes that have been decoded will be
     stored in 'consumed'.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_AsUTF16String (PyObject
          *unicode)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a Python byte string using the UTF-16
     encoding in native byte order.  The string always starts with a BOM
     mark.  Error handling is «strict».  Return ‘NULL’ if an exception
     was raised by the codec.


File: python.info,  Node: UTF-7 Codecs,  Next: Unicode-Escape Codecs,  Prev: UTF-16 Codecs,  Up: Built-in Codecs

7.9.3.19 UTF-7 Codecs
.....................

These are the UTF-7 codec APIs:

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeUTF7 (const char
          *str, Py_ssize_t size, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode object by decoding 'size' bytes of
     the UTF-7 encoded string 'str'.  Return ‘NULL’ if an exception was
     raised by the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeUTF7Stateful
          (const char *str, Py_ssize_t size, const char *errors,
          Py_ssize_t *consumed)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  If 'consumed' is ‘NULL’, behave like *note
     PyUnicode_DecodeUTF7(): 50e1.  If 'consumed' is not ‘NULL’,
     trailing incomplete UTF-7 base-64 sections will not be treated as
     an error.  Those bytes will not be decoded and the number of bytes
     that have been decoded will be stored in 'consumed'.


File: python.info,  Node: Unicode-Escape Codecs,  Next: Raw-Unicode-Escape Codecs,  Prev: UTF-7 Codecs,  Up: Built-in Codecs

7.9.3.20 Unicode-Escape Codecs
..............................

These are the «Unicode Escape» codec APIs:

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeUnicodeEscape
          (const char *str, Py_ssize_t size, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode object by decoding 'size' bytes of
     the Unicode-Escape encoded string 'str'.  Return ‘NULL’ if an
     exception was raised by the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_AsUnicodeEscapeString
          (PyObject *unicode)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Encode a Unicode object using Unicode-Escape and
     return the result as a bytes object.  Error handling is «strict».
     Return ‘NULL’ if an exception was raised by the codec.


File: python.info,  Node: Raw-Unicode-Escape Codecs,  Next: Latin-1 Codecs,  Prev: Unicode-Escape Codecs,  Up: Built-in Codecs

7.9.3.21 Raw-Unicode-Escape Codecs
..................................

These are the «Raw Unicode Escape» codec APIs:

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeRawUnicodeEscape
          (const char *str, Py_ssize_t size, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode object by decoding 'size' bytes of
     the Raw-Unicode-Escape encoded string 'str'.  Return ‘NULL’ if an
     exception was raised by the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_AsRawUnicodeEscapeString
          (PyObject *unicode)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Encode a Unicode object using Raw-Unicode-Escape
     and return the result as a bytes object.  Error handling is
     «strict».  Return ‘NULL’ if an exception was raised by the codec.


File: python.info,  Node: Latin-1 Codecs,  Next: ASCII Codecs,  Prev: Raw-Unicode-Escape Codecs,  Up: Built-in Codecs

7.9.3.22 Latin-1 Codecs
.......................

These are the Latin-1 codec APIs: Latin-1 corresponds to the first 256
Unicode ordinals and only these are accepted by the codecs during
encoding.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeLatin1 (const char
          *str, Py_ssize_t size, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode object by decoding 'size' bytes of
     the Latin-1 encoded string 'str'.  Return ‘NULL’ if an exception
     was raised by the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_AsLatin1String (PyObject
          *unicode)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Encode a Unicode object using Latin-1 and return
     the result as Python bytes object.  Error handling is «strict».
     Return ‘NULL’ if an exception was raised by the codec.


File: python.info,  Node: ASCII Codecs,  Next: Character Map Codecs,  Prev: Latin-1 Codecs,  Up: Built-in Codecs

7.9.3.23 ASCII Codecs
.....................

These are the ASCII codec APIs.  Only 7-bit ASCII data is accepted.  All
other codes generate errors.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeASCII (const char
          *str, Py_ssize_t size, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode object by decoding 'size' bytes of
     the ASCII encoded string 'str'.  Return ‘NULL’ if an exception was
     raised by the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_AsASCIIString (PyObject
          *unicode)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Encode a Unicode object using ASCII and return the
     result as Python bytes object.  Error handling is «strict».  Return
     ‘NULL’ if an exception was raised by the codec.


File: python.info,  Node: Character Map Codecs,  Next: MBCS codecs for Windows,  Prev: ASCII Codecs,  Up: Built-in Codecs

7.9.3.24 Character Map Codecs
.............................

This codec is special in that it can be used to implement many different
codecs (and this is in fact what was done to obtain most of the standard
codecs included in the ‘encodings’ package).  The codec uses mappings to
encode and decode characters.  The mapping objects provided must support
the *note __getitem__(): 588. mapping interface; dictionaries and
sequences work well.

These are the mapping codec APIs:

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeCharmap (const
          char *str, Py_ssize_t length, PyObject *mapping, const char
          *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Unicode object by decoding 'size' bytes of
     the encoded string 'str' using the given 'mapping' object.  Return
     ‘NULL’ if an exception was raised by the codec.

     If 'mapping' is ‘NULL’, Latin-1 decoding will be applied.  Else
     'mapping' must map bytes ordinals (integers in the range from 0 to
     255) to Unicode strings, integers (which are then interpreted as
     Unicode ordinals) or ‘None’.  Unmapped data bytes – ones which
     cause a *note LookupError: 2633, as well as ones which get mapped
     to ‘None’, ‘0xFFFE’ or ‘'\ufffe'’, are treated as undefined
     mappings and cause an error.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_AsCharmapString
          (PyObject *unicode, PyObject *mapping)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Encode a Unicode object using the given 'mapping'
     object and return the result as a bytes object.  Error handling is
     «strict».  Return ‘NULL’ if an exception was raised by the codec.

     The 'mapping' object must map Unicode ordinal integers to bytes
     objects, integers in the range from 0 to 255 or ‘None’.  Unmapped
     character ordinals (ones which cause a *note LookupError: 2633.) as
     well as mapped to ‘None’ are treated as «undefined mapping» and
     cause an error.

The following codec API is special in that maps Unicode to Unicode.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_Translate (PyObject
          *unicode, PyObject *table, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Translate a string by applying a character mapping
     table to it and return the resulting Unicode object.  Return ‘NULL’
     if an exception was raised by the codec.

     The mapping table must map Unicode ordinal integers to Unicode
     ordinal integers or ‘None’ (causing deletion of the character).

     Mapping tables need only provide the *note __getitem__(): 588.
     interface; dictionaries and sequences work well.  Unmapped
     character ordinals (ones which cause a *note LookupError: 2633.)
     are left untouched and are copied as-is.

     'errors' has the usual meaning for codecs.  It may be ‘NULL’ which
     indicates to use the default error handling.


File: python.info,  Node: MBCS codecs for Windows,  Prev: Character Map Codecs,  Up: Built-in Codecs

7.9.3.25 MBCS codecs for Windows
................................

These are the MBCS codec APIs.  They are currently only available on
Windows and use the Win32 MBCS converters to implement the conversions.
Note that MBCS (or DBCS) is a class of encodings, not just one.  The
target encoding is defined by the user settings on the machine running
the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeMBCS (const char
          *str, Py_ssize_t size, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. on Windows dalla versione 3.7.'  Create a Unicode
     object by decoding 'size' bytes of the MBCS encoded string 'str'.
     Return ‘NULL’ if an exception was raised by the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeMBCSStateful
          (const char *str, Py_ssize_t size, const char *errors,
          Py_ssize_t *consumed)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. on Windows dalla versione 3.7.'  If 'consumed' is
     ‘NULL’, behave like *note PyUnicode_DecodeMBCS(): 50da.  If
     'consumed' is not ‘NULL’, *note PyUnicode_DecodeMBCSStateful():
     50db. will not decode trailing lead byte and the number of bytes
     that have been decoded will be stored in 'consumed'.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_DecodeCodePageStateful
          (int code_page, const char *str, Py_ssize_t size, const char
          *errors, Py_ssize_t *consumed)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. on Windows dalla versione 3.7.'  Similar to *note
     PyUnicode_DecodeMBCSStateful(): 50db, except uses the code page
     specified by 'code_page'.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_AsMBCSString (PyObject
          *unicode)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. on Windows dalla versione 3.7.'  Encode a Unicode
     object using MBCS and return the result as Python bytes object.
     Error handling is «strict».  Return ‘NULL’ if an exception was
     raised by the codec.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_EncodeCodePage (int
          code_page, PyObject *unicode, const char *errors)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. on Windows dalla versione 3.7.'  Encode the Unicode
     object using the specified code page and return a Python bytes
     object.  Return ‘NULL’ if an exception was raised by the codec.
     Use ‘CP_ACP’ code page to get the MBCS encoder.

     Added in version 3.3.


File: python.info,  Node: Methods and Slot Functions,  Next: PyUnicodeWriter,  Prev: Built-in Codecs,  Up: Unicode Objects and Codecs

7.9.3.26 Methods and Slot Functions
...................................

The following APIs are capable of handling Unicode objects and strings
on input (we refer to them as strings in the descriptions) and return
Unicode objects or integers as appropriate.

They all return ‘NULL’ or ‘-1’ if an exception occurs.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_Concat (PyObject *left,
          PyObject *right)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Concat two strings giving a new Unicode string.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_Split (PyObject
          *unicode, PyObject *sep, Py_ssize_t maxsplit)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Split a string giving a list of Unicode strings.
     If 'sep' is ‘NULL’, splitting will be done at all whitespace
     substrings.  Otherwise, splits occur at the given separator.  At
     most 'maxsplit' splits will be done.  If negative, no limit is set.
     Separators are not included in the resulting list.

     On error, return ‘NULL’ with an exception set.

     Equivalent to *note str.split(): 10ac.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_RSplit (PyObject
          *unicode, PyObject *sep, Py_ssize_t maxsplit)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Similar to *note PyUnicode_Split(): 50f0, but
     splitting will be done beginning at the end of the string.

     On error, return ‘NULL’ with an exception set.

     Equivalent to *note str.rsplit(): 145d.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_Splitlines (PyObject
          *unicode, int keepends)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Split a Unicode string at line breaks, returning a
     list of Unicode strings.  CRLF is considered to be one line break.
     If 'keepends' is ‘0’, the Line break characters are not included in
     the resulting strings.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_Partition (PyObject
          *unicode, PyObject *sep)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Split a Unicode string at the first occurrence of
     'sep', and return a 3-tuple containing the part before the
     separator, the separator itself, and the part after the separator.
     If the separator is not found, return a 3-tuple containing the
     string itself, followed by two empty strings.

     'sep' must not be empty.

     On error, return ‘NULL’ with an exception set.

     Equivalent to *note str.partition(): 10ad.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_RPartition (PyObject
          *unicode, PyObject *sep)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Similar to *note PyUnicode_Partition(): 1880, but
     split a Unicode string at the last occurrence of 'sep'.  If the
     separator is not found, return a 3-tuple containing two empty
     strings, followed by the string itself.

     'sep' must not be empty.

     On error, return ‘NULL’ with an exception set.

     Equivalent to *note str.rpartition(): 1460.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_Join (PyObject
          *separator, PyObject *seq)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Join a sequence of strings using the given
     'separator' and return the resulting Unicode string.

 -- C Funzione: *note Py_ssize_t: c57. PyUnicode_Tailmatch (PyObject
          *unicode, PyObject *substr, Py_ssize_t start, Py_ssize_t end,
          int direction)
     ' Parte del *note ABI Stabile: 776.'  Return ‘1’ if 'substr'
     matches ‘unicode[start:end]’ at the given tail end ('direction' ==
     ‘-1’ means to do a prefix match, 'direction' == ‘1’ a suffix
     match), ‘0’ otherwise.  Return ‘-1’ if an error occurred.

 -- C Funzione: *note Py_ssize_t: c57. PyUnicode_Find (PyObject
          *unicode, PyObject *substr, Py_ssize_t start, Py_ssize_t end,
          int direction)
     ' Parte del *note ABI Stabile: 776.'  Return the first position of
     'substr' in ‘unicode[start:end]’ using the given 'direction'
     ('direction' == ‘1’ means to do a forward search, 'direction' ==
     ‘-1’ a backward search).  The return value is the index of the
     first match; a value of ‘-1’ indicates that no match was found, and
     ‘-2’ indicates that an error occurred and an exception has been
     set.

 -- C Funzione: *note Py_ssize_t: c57. PyUnicode_FindChar (PyObject
          *unicode, Py_UCS4 ch, Py_ssize_t start, Py_ssize_t end, int
          direction)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Return
     the first position of the character 'ch' in ‘unicode[start:end]’
     using the given 'direction' ('direction' == ‘1’ means to do a
     forward search, 'direction' == ‘-1’ a backward search).  The return
     value is the index of the first match; a value of ‘-1’ indicates
     that no match was found, and ‘-2’ indicates that an error occurred
     and an exception has been set.

     Added in version 3.3.

     Cambiato nella versione 3.7: 'start' and 'end' are now adjusted to
     behave like ‘unicode[start:end]’.

 -- C Funzione: *note Py_ssize_t: c57. PyUnicode_Count (PyObject
          *unicode, PyObject *substr, Py_ssize_t start, Py_ssize_t end)
     ' Parte del *note ABI Stabile: 776.'  Return the number of
     non-overlapping occurrences of 'substr' in ‘unicode[start:end]’.
     Return ‘-1’ if an error occurred.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_Replace (PyObject
          *unicode, PyObject *substr, PyObject *replstr, Py_ssize_t
          maxcount)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Replace at most 'maxcount' occurrences of 'substr'
     in 'unicode' with 'replstr' and return the resulting Unicode
     object.  'maxcount' == ‘-1’ means replace all occurrences.

 -- C Funzione: int PyUnicode_Compare (PyObject *left, PyObject *right)
     ' Parte del *note ABI Stabile: 776.'  Compare two strings and
     return ‘-1’, ‘0’, ‘1’ for less than, equal, and greater than,
     respectively.

     This function returns ‘-1’ upon failure, so one should call *note
     PyErr_Occurred(): 1c97. to check for errors.

     Vedi anche
     ..........

     The *note PyUnicode_Equal(): 3b2. function.

 -- C Funzione: int PyUnicode_Equal (PyObject *a, PyObject *b)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Test if
     two strings are equal:

        * Return ‘1’ if 'a' is equal to 'b'.

        * Return ‘0’ if 'a' is not equal to 'b'.

        * Set a *note TypeError: 198. exception and return ‘-1’ if 'a'
          or 'b' is not a *note str: 169. object.

     The function always succeeds if 'a' and 'b' are *note str: 169.
     objects.

     The function works for *note str: 169. subclasses, but does not
     honor custom ‘__eq__()’ method.

     Vedi anche
     ..........

     The *note PyUnicode_Compare(): ab6. function.

     Added in version 3.14.

 -- C Funzione: int PyUnicode_EqualToUTF8AndSize (PyObject *unicode,
          const char *string, Py_ssize_t size)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Compare
     a Unicode object with a char buffer which is interpreted as being
     UTF-8 or ASCII encoded and return true (‘1’) if they are equal, or
     false (‘0’) otherwise.  If the Unicode object contains surrogate
     code points (‘U+D800’ - ‘U+DFFF’) or the C string is not valid
     UTF-8, false (‘0’) is returned.

     This function does not raise exceptions.

     Added in version 3.13.

 -- C Funzione: int PyUnicode_EqualToUTF8 (PyObject *unicode, const char
          *string)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Similar
     to *note PyUnicode_EqualToUTF8AndSize(): 619, but compute 'string'
     length using ‘strlen()’.  If the Unicode object contains null
     characters, false (‘0’) is returned.

     Added in version 3.13.

 -- C Funzione: int PyUnicode_CompareWithASCIIString (PyObject *unicode,
          const char *string)
     ' Parte del *note ABI Stabile: 776.'  Compare a Unicode object,
     'unicode', with 'string' and return ‘-1’, ‘0’, ‘1’ for less than,
     equal, and greater than, respectively.  It is best to pass only
     ASCII-encoded strings, but the function interprets the input string
     as ISO-8859-1 if it contains non-ASCII characters.

     This function does not raise exceptions.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_RichCompare (PyObject
          *left, PyObject *right, int op)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Rich compare two Unicode strings and return one of
     the following:

        * ‘NULL’ in case an exception was raised

        * *note Py_True: 52ee. or *note Py_False: 52ed. for successful
          comparisons

        * *note Py_NotImplemented: 525e. in case the type combination is
          unknown

     Possible values for 'op' are *note Py_GT: 5265, *note Py_GE: 5266,
     *note Py_EQ: 5263, *note Py_NE: 5264, *note Py_LT: 5261, and *note
     Py_LE: 5262.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_Format (PyObject
          *format, PyObject *args)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new string object from 'format' and
     'args'; this is analogous to ‘format % args’.

 -- C Funzione: int PyUnicode_Contains (PyObject *unicode, PyObject
          *substr)
     ' Parte del *note ABI Stabile: 776.'  Check whether 'substr' is
     contained in 'unicode' and return true or false accordingly.

     'substr' has to coerce to a one element Unicode string.  ‘-1’ is
     returned if there was an error.

 -- C Funzione: void PyUnicode_InternInPlace (PyObject **p_unicode)
     ' Parte del *note ABI Stabile: 776.'  Intern the argument **note
     p_unicode: ab0. in place.  The argument must be the address of a
     pointer variable pointing to a Python Unicode string object.  If
     there is an existing interned string that is the same as **note
     p_unicode: ab0, it sets **note p_unicode: ab0. to it (releasing the
     reference to the old string object and creating a new *note strong
     reference: 5e2. to the interned string object), otherwise it leaves
     **note p_unicode: ab0. alone and interns it.

     (Clarification: even though there is a lot of talk about
     references, think of this function as reference-neutral.  You must
     own the object you pass in; after the call you no longer own the
     passed-in reference, but you newly own the result.)

     This function never raises an exception.  On error, it leaves its
     argument unchanged without interning it.

     Instances of subclasses of *note str: 169. may not be interned,
     that is, *note PyUnicode_CheckExact: 5334.(**note p_unicode: ab0.)
     must be true.  If it is not, then – as with any other error – the
     argument is left unchanged.

     Note that interned strings are not “immortal”.  You must keep a
     reference to the result to benefit from interning.

 -- C Funzione: *note PyObject: 5df. *PyUnicode_InternFromString (const
          char *str)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  A combination of *note PyUnicode_FromString():
     50ea. and *note PyUnicode_InternInPlace(): ab0, meant for
     statically allocated strings.

     Return a new («owned») reference to either a new Unicode string
     object that has been interned, or an earlier interned string object
     with the same value.

     Python may keep a reference to the result, or make it *note
     immortal: 290, preventing it from being garbage-collected promptly.
     For interning an unbounded number of different strings, such as
     ones coming from user input, prefer calling *note
     PyUnicode_FromString(): 50ea. and *note PyUnicode_InternInPlace():
     ab0. directly.

 -- C Funzione: unsigned int PyUnicode_CHECK_INTERNED (PyObject *str)

     Return a non-zero value if 'str' is interned, zero if not.  The
     'str' argument must be a string; this is not checked.  This
     function always succeeds.

     'Dettaglio dell’implementazione di CPython:' A non-zero return
     value may carry additional information about 'how' the string is
     interned.  The meaning of such non-zero values, as well as each
     specific string’s intern-related details, may change between
     CPython versions.


File: python.info,  Node: PyUnicodeWriter,  Next: Deprecated API<2>,  Prev: Methods and Slot Functions,  Up: Unicode Objects and Codecs

7.9.3.27 PyUnicodeWriter
........................

The *note PyUnicodeWriter: 3b3. API can be used to create a Python *note
str: 169. object.

Added in version 3.14.

 -- C Tipo: type PyUnicodeWriter

     A Unicode writer instance.

     The instance must be destroyed by *note PyUnicodeWriter_Finish():
     3b7. on success, or *note PyUnicodeWriter_Discard(): 3b6. on error.

 -- C Funzione: *note PyUnicodeWriter: 3b3. *PyUnicodeWriter_Create
          (Py_ssize_t length)

     Create a Unicode writer instance.

     'length' must be greater than or equal to ‘0’.

     If 'length' is greater than ‘0’, preallocate an internal buffer of
     'length' characters.

     Set an exception and return ‘NULL’ on error.

 -- C Funzione: *note PyObject: 5df. *PyUnicodeWriter_Finish
          (PyUnicodeWriter *writer)

     Return the final Python *note str: 169. object and destroy the
     writer instance.

     Set an exception and return ‘NULL’ on error.

     The writer instance is invalid after this call.

 -- C Funzione: void PyUnicodeWriter_Discard (PyUnicodeWriter *writer)

     Discard the internal Unicode buffer and destroy the writer
     instance.

     If 'writer' is ‘NULL’, no operation is performed.

     The writer instance is invalid after this call.

 -- C Funzione: int PyUnicodeWriter_WriteChar (PyUnicodeWriter *writer,
          Py_UCS4 ch)

     Write the single Unicode character 'ch' into 'writer'.

     On success, return ‘0’.  On error, set an exception, leave the
     writer unchanged, and return ‘-1’.

 -- C Funzione: int PyUnicodeWriter_WriteUTF8 (PyUnicodeWriter *writer,
          const char *str, Py_ssize_t size)

     Decode the string 'str' from UTF-8 in strict mode and write the
     output into 'writer'.

     'size' is the string length in bytes.  If 'size' is equal to ‘-1’,
     call ‘strlen(str)’ to get the string length.

     On success, return ‘0’.  On error, set an exception, leave the
     writer unchanged, and return ‘-1’.

     See also *note PyUnicodeWriter_DecodeUTF8Stateful(): 3b5.

 -- C Funzione: int PyUnicodeWriter_WriteASCII (PyUnicodeWriter *writer,
          const char *str, Py_ssize_t size)

     Write the ASCII string 'str' into 'writer'.

     'size' is the string length in bytes.  If 'size' is equal to ‘-1’,
     call ‘strlen(str)’ to get the string length.

     'str' must only contain ASCII characters.  The behavior is
     undefined if 'str' contains non-ASCII characters.

     On success, return ‘0’.  On error, set an exception, leave the
     writer unchanged, and return ‘-1’.

     Added in version 3.14.

 -- C Funzione: int PyUnicodeWriter_WriteWideChar (PyUnicodeWriter
          *writer, const wchar_t *str, Py_ssize_t size)

     Write the wide string 'str' into 'writer'.

     'size' is a number of wide characters.  If 'size' is equal to ‘-1’,
     call ‘wcslen(str)’ to get the string length.

     On success, return ‘0’.  On error, set an exception, leave the
     writer unchanged, and return ‘-1’.

 -- C Funzione: int PyUnicodeWriter_WriteUCS4 (PyUnicodeWriter *writer,
          Py_UCS4 *str, Py_ssize_t size)

     Writer the UCS4 string 'str' into 'writer'.

     'size' is a number of UCS4 characters.

     On success, return ‘0’.  On error, set an exception, leave the
     writer unchanged, and return ‘-1’.

 -- C Funzione: int PyUnicodeWriter_WriteStr (PyUnicodeWriter *writer,
          PyObject *obj)

     Call *note PyObject_Str(): 1232. on 'obj' and write the output into
     'writer'.

     On success, return ‘0’.  On error, set an exception, leave the
     writer unchanged, and return ‘-1’.

 -- C Funzione: int PyUnicodeWriter_WriteRepr (PyUnicodeWriter *writer,
          PyObject *obj)

     Call *note PyObject_Repr(): 1231. on 'obj' and write the output
     into 'writer'.

     On success, return ‘0’.  On error, set an exception, leave the
     writer unchanged, and return ‘-1’.

 -- C Funzione: int PyUnicodeWriter_WriteSubstring (PyUnicodeWriter
          *writer, PyObject *str, Py_ssize_t start, Py_ssize_t end)

     Write the substring ‘str[start:end]’ into 'writer'.

     'str' must be Python *note str: 169. object.  'start' must be
     greater than or equal to 0, and less than or equal to 'end'.  'end'
     must be less than or equal to 'str' length.

     On success, return ‘0’.  On error, set an exception, leave the
     writer unchanged, and return ‘-1’.

 -- C Funzione: int PyUnicodeWriter_Format (PyUnicodeWriter *writer,
          const char *format, ...)

     Similar to *note PyUnicode_FromFormat(): 62b, but write the output
     directly into 'writer'.

     On success, return ‘0’.  On error, set an exception, leave the
     writer unchanged, and return ‘-1’.

 -- C Funzione: int PyUnicodeWriter_DecodeUTF8Stateful (PyUnicodeWriter
          *writer, const char *string, Py_ssize_t length, const char
          *errors, Py_ssize_t *consumed)

     Decode the string 'str' from UTF-8 with 'errors' error handler and
     write the output into 'writer'.

     'size' is the string length in bytes.  If 'size' is equal to ‘-1’,
     call ‘strlen(str)’ to get the string length.

     'errors' is an *note error handler: 1b57. name, such as
     ‘"replace"’.  If 'errors' is ‘NULL’, use the strict error handler.

     If 'consumed' is not ‘NULL’, set '*consumed' to the number of
     decoded bytes on success.  If 'consumed' is ‘NULL’, treat trailing
     incomplete UTF-8 byte sequences as an error.

     On success, return ‘0’.  On error, set an exception, leave the
     writer unchanged, and return ‘-1’.

     See also *note PyUnicodeWriter_WriteUTF8(): 3bf.


File: python.info,  Node: Deprecated API<2>,  Prev: PyUnicodeWriter,  Up: Unicode Objects and Codecs

7.9.3.28 Deprecated API
.......................

The following API is deprecated.

 -- C Tipo: type Py_UNICODE

     This is a typedef of ‘wchar_t’, which is a 16-bit type or 32-bit
     type depending on the platform.  Please use ‘wchar_t’ directly
     instead.

     Cambiato nella versione 3.3: In previous versions, this was a
     16-bit type or a 32-bit type depending on whether you selected a
     «narrow» or «wide» Unicode version of Python at build time.

     Deprecated since version 3.13, will be removed in version 3.15.

 -- C Funzione: int PyUnicode_READY (PyObject *unicode)

     Do nothing and return ‘0’.  This API is kept only for backward
     compatibility, but there are no plans to remove it.

     Added in version 3.3.

     Deprecato dalla versione 3.10: This API does nothing since Python
     3.12.  Previously, this needed to be called for each string created
     using the old API (‘PyUnicode_FromUnicode()’ or similar).

 -- C Funzione: unsigned int PyUnicode_IS_READY (PyObject *unicode)

     Do nothing and return ‘1’.  This API is kept only for backward
     compatibility, but there are no plans to remove it.

     Added in version 3.3.

     Deprecato dalla versione 3.14: This API does nothing since Python
     3.12.  Previously, this could be called to check if *note
     PyUnicode_READY(): 434. is necessary.


File: python.info,  Node: Tuple Objects,  Next: Struct Sequence Objects,  Prev: Unicode Objects and Codecs,  Up: Sequence Objects

7.9.3.29 Tuple Objects
......................

 -- C Tipo: type PyTupleObject

     This subtype of *note PyObject: 5df. represents a Python tuple
     object.

 -- C Variabile: *note PyTypeObject: c9e. PyTuple_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python tuple type; it is the same
     object as *note tuple: 614. in the Python layer.

 -- C Funzione: int PyTuple_Check (PyObject *p)

     Return true if 'p' is a tuple object or an instance of a subtype of
     the tuple type.  This function always succeeds.

 -- C Funzione: int PyTuple_CheckExact (PyObject *p)

     Return true if 'p' is a tuple object, but not an instance of a
     subtype of the tuple type.  This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyTuple_New (Py_ssize_t len)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new tuple object of size 'len', or ‘NULL’
     with an exception set on failure.

 -- C Funzione: *note PyObject: 5df. *PyTuple_Pack (Py_ssize_t n, ...)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new tuple object of size 'n', or ‘NULL’
     with an exception set on failure.  The tuple values are initialized
     to the subsequent 'n' C arguments pointing to Python objects.
     ‘PyTuple_Pack(2, a, b)’ is equivalent to ‘Py_BuildValue("(OO)", a,
     b)’.

 -- C Funzione: *note Py_ssize_t: c57. PyTuple_Size (PyObject *p)
     ' Parte del *note ABI Stabile: 776.'  Take a pointer to a tuple
     object, and return the size of that tuple.  On error, return ‘-1’
     with an exception set.

 -- C Funzione: *note Py_ssize_t: c57. PyTuple_GET_SIZE (PyObject *p)

     Like *note PyTuple_Size(): 50b0, but without error checking.

 -- C Funzione: *note PyObject: 5df. *PyTuple_GetItem (PyObject *p,
          Py_ssize_t pos)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Return the object at position 'pos' in
     the tuple pointed to by 'p'.  If 'pos' is negative or out of
     bounds, return ‘NULL’ and set an *note IndexError: 173c. exception.

     The returned reference is borrowed from the tuple 'p' (that is: it
     is only valid as long as you hold a reference to 'p').  To get a
     *note strong reference: 5e2, use *note
     Py_NewRef(PyTuple_GetItem(...)): a9c. or *note
     PySequence_GetItem(): 1e1c.

 -- C Funzione: *note PyObject: 5df. *PyTuple_GET_ITEM (PyObject *p,
          Py_ssize_t pos)
     'Valore di ritorno: Riferimento preso in prestito.'  Like *note
     PyTuple_GetItem(): 4ea0, but does no checking of its arguments.

 -- C Funzione: *note PyObject: 5df. *PyTuple_GetSlice (PyObject *p,
          Py_ssize_t low, Py_ssize_t high)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return the slice of the tuple pointed to by 'p'
     between 'low' and 'high', or ‘NULL’ with an exception set on
     failure.

     This is the equivalent of the Python expression ‘p[low:high]’.
     Indexing from the end of the tuple is not supported.

 -- C Funzione: int PyTuple_SetItem (PyObject *p, Py_ssize_t pos,
          PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Insert a reference to object
     'o' at position 'pos' of the tuple pointed to by 'p'.  Return ‘0’
     on success.  If 'pos' is out of bounds, return ‘-1’ and set an
     *note IndexError: 173c. exception.

          Nota: This function «steals» a reference to 'o' and discards a
          reference to an item already in the tuple at the affected
          position.

 -- C Funzione: void PyTuple_SET_ITEM (PyObject *p, Py_ssize_t pos,
          PyObject *o)

     Like *note PyTuple_SetItem(): 4ea1, but does no error checking, and
     should 'only' be used to fill in brand new tuples.

     Bounds checking is performed as an assertion if Python is built in
     *note debug mode: 50a. or *note with assertions: 62d.

          Nota: This function «steals» a reference to 'o', and, unlike
          *note PyTuple_SetItem(): 4ea1, does 'not' discard a reference
          to any item that is being replaced; any reference in the tuple
          at position 'pos' will be leaked.

          Avvertimento: This macro should 'only' be used on tuples that
          are newly created.  Using this macro on a tuple that is
          already in use (or in other words, has a refcount > 1) could
          lead to undefined behavior.

 -- C Funzione: int _PyTuple_Resize (PyObject **p, Py_ssize_t newsize)

     Can be used to resize a tuple.  'newsize' will be the new length of
     the tuple.  Because tuples are 'supposed' to be immutable, this
     should only be used if there is only one reference to the object.
     Do 'not' use this if the tuple may already be known to some other
     part of the code.  The tuple will always grow or shrink at the end.
     Think of this as destroying the old tuple and creating a new one,
     only more efficiently.  Returns ‘0’ on success.  Client code should
     never assume that the resulting value of ‘*p’ will be the same as
     before calling this function.  If the object referenced by ‘*p’ is
     replaced, the original ‘*p’ is destroyed.  On failure, returns ‘-1’
     and sets ‘*p’ to ‘NULL’, and raises *note MemoryError: 1786. or
     *note SystemError: 796.


File: python.info,  Node: Struct Sequence Objects,  Next: List Objects,  Prev: Tuple Objects,  Up: Sequence Objects

7.9.3.30 Struct Sequence Objects
................................

Struct sequence objects are the C equivalent of *note namedtuple(): 4e1.
objects, i.e.  a sequence whose items can also be accessed through
attributes.  To create a struct sequence, you first have to create a
specific struct sequence type.

 -- C Funzione: *note PyTypeObject: c9e. *PyStructSequence_NewType
          (PyStructSequence_Desc *desc)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a new struct sequence type from the data in
     'desc', described below.  Instances of the resulting type can be
     created with *note PyStructSequence_New(): 5090.

     Return ‘NULL’ with an exception set on failure.

 -- C Funzione: void PyStructSequence_InitType (PyTypeObject *type,
          PyStructSequence_Desc *desc)

     Initializes a struct sequence type 'type' from 'desc' in place.

 -- C Funzione: int PyStructSequence_InitType2 (PyTypeObject *type,
          PyStructSequence_Desc *desc)

     Like *note PyStructSequence_InitType(): 1205, but returns ‘0’ on
     success and ‘-1’ with an exception set on failure.

     Added in version 3.4.

 -- C Tipo: type PyStructSequence_Desc
     ' Parte del *note ABI Stabile: 776. (inclusi tutti i membri).'
     Contains the meta information of a struct sequence type to create.

      -- C Membro: const char *name

          Fully qualified name of the type; null-terminated UTF-8
          encoded.  The name must contain the module name.

      -- C Membro: const char *doc

          Pointer to docstring for the type or ‘NULL’ to omit.

      -- C Membro: *note PyStructSequence_Field: db5. *fields

          Pointer to ‘NULL’-terminated array with field names of the new
          type.

      -- C Membro: int n_in_sequence

          Number of fields visible to the Python side (if used as
          tuple).

 -- C Tipo: type PyStructSequence_Field
     ' Parte del *note ABI Stabile: 776. (inclusi tutti i membri).'
     Describes a field of a struct sequence.  As a struct sequence is
     modeled as a tuple, all fields are typed as *note PyObject: 5df.*.
     The index in the *note fields: 5370. array of the *note
     PyStructSequence_Desc: db6. determines which field of the struct
     sequence is described.

      -- C Membro: const char *name

          Name for the field or ‘NULL’ to end the list of named fields,
          set to *note PyStructSequence_UnnamedField: b7b. to leave
          unnamed.

      -- C Membro: const char *doc

          Field docstring or ‘NULL’ to omit.

 -- C Variabile: const char *const PyStructSequence_UnnamedField
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Special
     value for a field name to leave it unnamed.

     Cambiato nella versione 3.9: The type was changed from ‘char *’.

 -- C Funzione: *note PyObject: 5df. *PyStructSequence_New (PyTypeObject
          *type)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Creates an instance of 'type', which must have been
     created with *note PyStructSequence_NewType(): 5091.

     Return ‘NULL’ with an exception set on failure.

 -- C Funzione: *note PyObject: 5df. *PyStructSequence_GetItem (PyObject
          *p, Py_ssize_t pos)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Return the object at position 'pos' in
     the struct sequence pointed to by 'p'.

     Bounds checking is performed as an assertion if Python is built in
     *note debug mode: 50a. or *note with assertions: 62d.

 -- C Funzione: *note PyObject: 5df. *PyStructSequence_GET_ITEM
          (PyObject *p, Py_ssize_t pos)
     'Valore di ritorno: Riferimento preso in prestito.'  Alias to *note
     PyStructSequence_GetItem(): 508f.

     Cambiato nella versione 3.13: Now implemented as an alias to *note
     PyStructSequence_GetItem(): 508f.

 -- C Funzione: void PyStructSequence_SetItem (PyObject *p, Py_ssize_t
          pos, PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Sets the field at index 'pos'
     of the struct sequence 'p' to value 'o'.  Like *note
     PyTuple_SET_ITEM(): 62e, this should only be used to fill in brand
     new instances.

     Bounds checking is performed as an assertion if Python is built in
     *note debug mode: 50a. or *note with assertions: 62d.

          Nota: This function «steals» a reference to 'o'.

 -- C Funzione: void PyStructSequence_SET_ITEM (PyObject *p, Py_ssize_t
          *pos, PyObject *o)

     Alias to *note PyStructSequence_SetItem(): 5092.

     Cambiato nella versione 3.13: Now implemented as an alias to *note
     PyStructSequence_SetItem(): 5092.


File: python.info,  Node: List Objects,  Prev: Struct Sequence Objects,  Up: Sequence Objects

7.9.3.31 List Objects
.....................

 -- C Tipo: type PyListObject

     This subtype of *note PyObject: 5df. represents a Python list
     object.

 -- C Variabile: *note PyTypeObject: c9e. PyList_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python list type.  This is the
     same object as *note list: 24d. in the Python layer.

 -- C Funzione: int PyList_Check (PyObject *p)

     Return true if 'p' is a list object or an instance of a subtype of
     the list type.  This function always succeeds.

 -- C Funzione: int PyList_CheckExact (PyObject *p)

     Return true if 'p' is a list object, but not an instance of a
     subtype of the list type.  This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyList_New (Py_ssize_t len)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new list of length 'len' on success, or
     ‘NULL’ on failure.

          Nota: If 'len' is greater than zero, the returned list
          object’s items are set to ‘NULL’.  Thus you cannot use
          abstract API functions such as *note PySequence_SetItem():
          1e1d. or expose the object to Python code before setting all
          items to a real object with *note PyList_SetItem(): 18a2. or
          *note PyList_SET_ITEM(): 62f.  The following APIs are safe
          APIs before the list is fully initialized: *note
          PyList_SetItem(): 18a2. and *note PyList_SET_ITEM(): 62f.

 -- C Funzione: *note Py_ssize_t: c57. PyList_Size (PyObject *list)
     ' Parte del *note ABI Stabile: 776.'

     Return the length of the list object in 'list'; this is equivalent
     to ‘len(list)’ on a list object.

 -- C Funzione: *note Py_ssize_t: c57. PyList_GET_SIZE (PyObject *list)

     Similar to *note PyList_Size(): 1621, but without error checking.

 -- C Funzione: *note PyObject: 5df. *PyList_GetItemRef (PyObject *list,
          Py_ssize_t index)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.13.'  Return the object at position
     'index' in the list pointed to by 'list'.  The position must be
     non-negative; indexing from the end of the list is not supported.
     If 'index' is out of bounds (‘<0 or >=len(list)’), return ‘NULL’
     and set an *note IndexError: 173c. exception.

     Added in version 3.13.

 -- C Funzione: *note PyObject: 5df. *PyList_GetItem (PyObject *list,
          Py_ssize_t index)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Like *note PyList_GetItemRef(): 5fe, but
     returns a *note borrowed reference: 3d7. instead of a *note strong
     reference: 5e2.

 -- C Funzione: *note PyObject: 5df. *PyList_GET_ITEM (PyObject *list,
          Py_ssize_t i)
     'Valore di ritorno: Riferimento preso in prestito.'  Similar to
     *note PyList_GetItem(): 5ff, but without error checking.

 -- C Funzione: int PyList_SetItem (PyObject *list, Py_ssize_t index,
          PyObject *item)
     ' Parte del *note ABI Stabile: 776.'  Set the item at index 'index'
     in list to 'item'.  Return ‘0’ on success.  If 'index' is out of
     bounds, return ‘-1’ and set an *note IndexError: 173c. exception.

          Nota: This function «steals» a reference to 'item' and
          discards a reference to an item already in the list at the
          affected position.

 -- C Funzione: void PyList_SET_ITEM (PyObject *list, Py_ssize_t i,
          PyObject *o)

     Macro form of *note PyList_SetItem(): 18a2. without error checking.
     This is normally only used to fill in new lists where there is no
     previous content.

     Bounds checking is performed as an assertion if Python is built in
     *note debug mode: 50a. or *note with assertions: 62d.

          Nota: This macro «steals» a reference to 'item', and, unlike
          *note PyList_SetItem(): 18a2, does 'not' discard a reference
          to any item that is being replaced; any reference in 'list' at
          position 'i' will be leaked.

 -- C Funzione: int PyList_Insert (PyObject *list, Py_ssize_t index,
          PyObject *item)
     ' Parte del *note ABI Stabile: 776.'  Insert the item 'item' into
     list 'list' in front of index 'index'.  Return ‘0’ if successful;
     return ‘-1’ and set an exception if unsuccessful.  Analogous to
     ‘list.insert(index, item)’.

 -- C Funzione: int PyList_Append (PyObject *list, PyObject *item)
     ' Parte del *note ABI Stabile: 776.'  Append the object 'item' at
     the end of list 'list'.  Return ‘0’ if successful; return ‘-1’ and
     set an exception if unsuccessful.  Analogous to
     ‘list.append(item)’.

 -- C Funzione: *note PyObject: 5df. *PyList_GetSlice (PyObject *list,
          Py_ssize_t low, Py_ssize_t high)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a list of the objects in 'list' containing
     the objects 'between' 'low' and 'high'.  Return ‘NULL’ and set an
     exception if unsuccessful.  Analogous to ‘list[low:high]’.
     Indexing from the end of the list is not supported.

 -- C Funzione: int PyList_SetSlice (PyObject *list, Py_ssize_t low,
          Py_ssize_t high, PyObject *itemlist)
     ' Parte del *note ABI Stabile: 776.'  Set the slice of 'list'
     between 'low' and 'high' to the contents of 'itemlist'.  Analogous
     to ‘list[low:high] = itemlist’.  The 'itemlist' may be ‘NULL’,
     indicating the assignment of an empty list (slice deletion).
     Return ‘0’ on success, ‘-1’ on failure.  Indexing from the end of
     the list is not supported.

 -- C Funzione: int PyList_Extend (PyObject *list, PyObject *iterable)

     Extend 'list' with the contents of 'iterable'.  This is the same as
     ‘PyList_SetSlice(list, PY_SSIZE_T_MAX, PY_SSIZE_T_MAX, iterable)’
     and analogous to ‘list.extend(iterable)’ or ‘list += iterable’.

     Raise an exception and return ‘-1’ if 'list' is not a *note list:
     24d. object.  Return 0 on success.

     Added in version 3.13.

 -- C Funzione: int PyList_Clear (PyObject *list)

     Remove all items from 'list'.  This is the same as
     ‘PyList_SetSlice(list, 0, PY_SSIZE_T_MAX, NULL)’ and analogous to
     ‘list.clear()’ or ‘del list[:]’.

     Raise an exception and return ‘-1’ if 'list' is not a *note list:
     24d. object.  Return 0 on success.

     Added in version 3.13.

 -- C Funzione: int PyList_Sort (PyObject *list)
     ' Parte del *note ABI Stabile: 776.'  Sort the items of 'list' in
     place.  Return ‘0’ on success, ‘-1’ on failure.  This is equivalent
     to ‘list.sort()’.

 -- C Funzione: int PyList_Reverse (PyObject *list)
     ' Parte del *note ABI Stabile: 776.'  Reverse the items of 'list'
     in place.  Return ‘0’ on success, ‘-1’ on failure.  This is the
     equivalent of ‘list.reverse()’.

 -- C Funzione: *note PyObject: 5df. *PyList_AsTuple (PyObject *list)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     Return a new tuple object containing the contents of 'list';
     equivalent to ‘tuple(list)’.


File: python.info,  Node: Container Objects,  Next: Function Objects<2>,  Prev: Sequence Objects,  Up: Concrete Objects Layer

7.9.4 Container Objects
-----------------------

* Menu:

* Dictionary Objects::
* Set Objects::


File: python.info,  Node: Dictionary Objects,  Next: Set Objects,  Up: Container Objects

7.9.4.1 Dictionary Objects
..........................

 -- C Tipo: type PyDictObject

     This subtype of *note PyObject: 5df. represents a Python dictionary
     object.

 -- C Variabile: *note PyTypeObject: c9e. PyDict_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python dictionary type.  This is
     the same object as *note dict: 183. in the Python layer.

 -- C Funzione: int PyDict_Check (PyObject *p)

     Return true if 'p' is a dict object or an instance of a subtype of
     the dict type.  This function always succeeds.

 -- C Funzione: int PyDict_CheckExact (PyObject *p)

     Return true if 'p' is a dict object, but not an instance of a
     subtype of the dict type.  This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyDict_New ()
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new empty dictionary, or ‘NULL’ on
     failure.

 -- C Funzione: *note PyObject: 5df. *PyDictProxy_New (PyObject
          *mapping)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a *note types.MappingProxyType: 699. object
     for a mapping which enforces read-only behavior.  This is normally
     used to create a view to prevent modification of the dictionary for
     non-dynamic class types.

 -- C Variabile: *note PyTypeObject: c9e. PyDictProxy_Type
     ' Parte del *note ABI Stabile: 776.'  The type object for mapping
     proxy objects created by *note PyDictProxy_New(): 4f8f. and for the
     read-only ‘__dict__’ attribute of many built-in types.  A *note
     PyDictProxy_Type: 4f90. instance provides a dynamic, read-only view
     of an underlying dictionary: changes to the underlying dictionary
     are reflected in the proxy, but the proxy itself does not support
     mutation operations.  This corresponds to *note
     types.MappingProxyType: 699. in Python.

 -- C Funzione: void PyDict_Clear (PyObject *p)
     ' Parte del *note ABI Stabile: 776.'  Empty an existing dictionary
     of all key-value pairs.

 -- C Funzione: int PyDict_Contains (PyObject *p, PyObject *key)
     ' Parte del *note ABI Stabile: 776.'  Determine if dictionary 'p'
     contains 'key'.  If an item in 'p' matches 'key', return ‘1’,
     otherwise return ‘0’.  On error, return ‘-1’.  This is equivalent
     to the Python expression ‘key in p’.

 -- C Funzione: int PyDict_ContainsString (PyObject *p, const char *key)

     This is the same as *note PyDict_Contains(): 5de, but 'key' is
     specified as a const char* UTF-8 encoded bytes string, rather than
     a *note PyObject: 5df.*.

     Added in version 3.13.

 -- C Funzione: *note PyObject: 5df. *PyDict_Copy (PyObject *p)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new dictionary that contains the same
     key-value pairs as 'p'.

 -- C Funzione: int PyDict_SetItem (PyObject *p, PyObject *key, PyObject
          *val)
     ' Parte del *note ABI Stabile: 776.'  Insert 'val' into the
     dictionary 'p' with a key of 'key'.  'key' must be *note hashable:
     825.; if it isn’t, *note TypeError: 198. will be raised.  Return
     ‘0’ on success or ‘-1’ on failure.  This function 'does not' steal
     a reference to 'val'.

 -- C Funzione: int PyDict_SetItemString (PyObject *p, const char *key,
          PyObject *val)
     ' Parte del *note ABI Stabile: 776.'  This is the same as *note
     PyDict_SetItem(): 4ea2, but 'key' is specified as a const char*
     UTF-8 encoded bytes string, rather than a *note PyObject: 5df.*.

 -- C Funzione: int PyDict_DelItem (PyObject *p, PyObject *key)
     ' Parte del *note ABI Stabile: 776.'  Remove the entry in
     dictionary 'p' with key 'key'.  'key' must be *note hashable: 825.;
     if it isn’t, *note TypeError: 198. is raised.  If 'key' is not in
     the dictionary, *note KeyError: 5e7. is raised.  Return ‘0’ on
     success or ‘-1’ on failure.

 -- C Funzione: int PyDict_DelItemString (PyObject *p, const char *key)
     ' Parte del *note ABI Stabile: 776.'  This is the same as *note
     PyDict_DelItem(): 4f96, but 'key' is specified as a const char*
     UTF-8 encoded bytes string, rather than a *note PyObject: 5df.*.

 -- C Funzione: int PyDict_GetItemRef (PyObject *p, PyObject *key,
          PyObject **result)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Return a
     new *note strong reference: 5e2. to the object from dictionary 'p'
     which has a key 'key':

        * If the key is present, set '*result' to a new *note strong
          reference: 5e2. to the value and return ‘1’.

        * If the key is missing, set '*result' to ‘NULL’ and return ‘0’.

        * On error, raise an exception and return ‘-1’.

     Added in version 3.13.

     See also the *note PyObject_GetItem(): 5ea. function.

 -- C Funzione: *note PyObject: 5df. *PyDict_GetItem (PyObject *p,
          PyObject *key)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Return a *note borrowed reference: 3d7.
     to the object from dictionary 'p' which has a key 'key'.  Return
     ‘NULL’ if the key 'key' is missing 'without' setting an exception.

          Nota: Exceptions that occur while this calls *note __hash__():
          cf5. and *note __eq__(): cf4. methods are silently ignored.
          Prefer the *note PyDict_GetItemWithError(): 5e1. function
          instead.

     Cambiato nella versione 3.10: Calling this API without an *note
     attached thread state: 4eba. had been allowed for historical
     reason.  It is no longer allowed.

 -- C Funzione: *note PyObject: 5df. *PyDict_GetItemWithError (PyObject
          *p, PyObject *key)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Variant of *note PyDict_GetItem(): 628.
     that does not suppress exceptions.  Return ‘NULL’ 'with' an
     exception set if an exception occurred.  Return ‘NULL’ 'without' an
     exception set if the key wasn’t present.

 -- C Funzione: *note PyObject: 5df. *PyDict_GetItemString (PyObject *p,
          const char *key)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  This is the same as *note
     PyDict_GetItem(): 628, but 'key' is specified as a const char*
     UTF-8 encoded bytes string, rather than a *note PyObject: 5df.*.

          Nota: Exceptions that occur while this calls *note __hash__():
          cf5. and *note __eq__(): cf4. methods or while creating the
          temporary *note str: 169. object are silently ignored.  Prefer
          using the *note PyDict_GetItemWithError(): 5e1. function with
          your own *note PyUnicode_FromString(): 50ea. 'key' instead.

 -- C Funzione: int PyDict_GetItemStringRef (PyObject *p, const char
          *key, PyObject **result)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Similar
     to *note PyDict_GetItemRef(): 5e0, but 'key' is specified as a
     const char* UTF-8 encoded bytes string, rather than a *note
     PyObject: 5df.*.

     Added in version 3.13.

 -- C Funzione: *note PyObject: 5df. *PyDict_SetDefault (PyObject *p,
          PyObject *key, PyObject *defaultobj)
     'Valore di ritorno: Riferimento preso in prestito.'  This is the
     same as the Python-level *note dict.setdefault(): 127b.  If
     present, it returns the value corresponding to 'key' from the
     dictionary 'p'.  If the key is not in the dict, it is inserted with
     value 'defaultobj' and 'defaultobj' is returned.  This function
     evaluates the hash function of 'key' only once, instead of
     evaluating it independently for the lookup and the insertion.

     Added in version 3.4.

 -- C Funzione: int PyDict_SetDefaultRef (PyObject *p, PyObject *key,
          PyObject *default_value, PyObject **result)

     Inserts 'default_value' into the dictionary 'p' with a key of 'key'
     if the key is not already present in the dictionary.  If 'result'
     is not ‘NULL’, then '*result' is set to a *note strong reference:
     5e2. to either 'default_value', if the key was not present, or the
     existing value, if 'key' was already present in the dictionary.
     Returns ‘1’ if the key was present and 'default_value' was not
     inserted, or ‘0’ if the key was not present and 'default_value' was
     inserted.  On failure, returns ‘-1’, sets an exception, and sets
     ‘*result’ to ‘NULL’.

     For clarity: if you have a strong reference to 'default_value'
     before calling this function, then after it returns, you hold a
     strong reference to both 'default_value' and '*result' (if it’s not
     ‘NULL’).  These may refer to the same object: in that case you hold
     two separate references to it.

     Added in version 3.13.

 -- C Funzione: int PyDict_Pop (PyObject *p, PyObject *key, PyObject
          **result)

     Remove 'key' from dictionary 'p' and optionally return the removed
     value.  Do not raise *note KeyError: 5e7. if the key is missing.

        - If the key is present, set '*result' to a new reference to the
          removed value if 'result' is not ‘NULL’, and return ‘1’.

        - If the key is missing, set '*result' to ‘NULL’ if 'result' is
          not ‘NULL’, and return ‘0’.

        - On error, raise an exception and return ‘-1’.

     Similar to *note dict.pop(): 5e6, but without the default value and
     not raising *note KeyError: 5e7. if the key is missing.

     Added in version 3.13.

 -- C Funzione: int PyDict_PopString (PyObject *p, const char *key,
          PyObject **result)

     Similar to *note PyDict_Pop(): 422, but 'key' is specified as a
     const char* UTF-8 encoded bytes string, rather than a *note
     PyObject: 5df.*.

     Added in version 3.13.

 -- C Funzione: *note PyObject: 5df. *PyDict_Items (PyObject *p)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a *note PyListObject: 5280. containing all
     the items from the dictionary.

 -- C Funzione: *note PyObject: 5df. *PyDict_Keys (PyObject *p)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a *note PyListObject: 5280. containing all
     the keys from the dictionary.

 -- C Funzione: *note PyObject: 5df. *PyDict_Values (PyObject *p)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a *note PyListObject: 5280. containing all
     the values from the dictionary 'p'.

 -- C Funzione: *note Py_ssize_t: c57. PyDict_Size (PyObject *p)
     ' Parte del *note ABI Stabile: 776.'

     Return the number of items in the dictionary.  This is equivalent
     to ‘len(p)’ on a dictionary.

 -- C Funzione: *note Py_ssize_t: c57. PyDict_GET_SIZE (PyObject *p)

     Similar to *note PyDict_Size(): 4f9d, but without error checking.

 -- C Funzione: int PyDict_Next (PyObject *p, Py_ssize_t *ppos, PyObject
          **pkey, PyObject **pvalue)
     ' Parte del *note ABI Stabile: 776.'  Iterate over all key-value
     pairs in the dictionary 'p'.  The *note Py_ssize_t: c57. referred
     to by 'ppos' must be initialized to ‘0’ prior to the first call to
     this function to start the iteration; the function returns true for
     each pair in the dictionary, and false once all pairs have been
     reported.  The parameters 'pkey' and 'pvalue' should either point
     to *note PyObject: 5df.* variables that will be filled in with each
     key and value, respectively, or may be ‘NULL’.  Any references
     returned through them are borrowed.  'ppos' should not be altered
     during iteration.  Its value represents offsets within the internal
     dictionary structure, and since the structure is sparse, the
     offsets are not consecutive.

     For example:

          PyObject *key, *value;
          Py_ssize_t pos = 0;

          while (PyDict_Next(self->dict, &pos, &key, &value)) {
              /* do something interesting with the values... */
              ...
          }

     The dictionary 'p' should not be mutated during iteration.  It is
     safe to modify the values of the keys as you iterate over the
     dictionary, but only so long as the set of keys does not change.
     For example:

          PyObject *key, *value;
          Py_ssize_t pos = 0;

          while (PyDict_Next(self->dict, &pos, &key, &value)) {
              long i = PyLong_AsLong(value);
              if (i == -1 && PyErr_Occurred()) {
                  return -1;
              }
              PyObject *o = PyLong_FromLong(i + 1);
              if (o == NULL)
                  return -1;
              if (PyDict_SetItem(self->dict, key, o) < 0) {
                  Py_DECREF(o);
                  return -1;
              }
              Py_DECREF(o);
          }

     The function is not thread-safe in the *note free-threaded: 1f4.
     build without external synchronization.  You can use *note
     Py_BEGIN_CRITICAL_SECTION: 5384. to lock the dictionary while
     iterating over it:

          Py_BEGIN_CRITICAL_SECTION(self->dict);
          while (PyDict_Next(self->dict, &pos, &key, &value)) {
              ...
          }
          Py_END_CRITICAL_SECTION();

          Nota: On the free-threaded build, this function can be used
          safely inside a critical section.  However, the references
          returned for 'pkey' and 'pvalue' are *note borrowed: 3d7. and
          are only valid while the critical section is held.  If you
          need to use these objects outside the critical section or when
          the critical section can be suspended, create a *note strong
          reference: 5e2. (for example, using *note Py_NewRef(): a9c.).

 -- C Funzione: int PyDict_Merge (PyObject *a, PyObject *b, int
          override)
     ' Parte del *note ABI Stabile: 776.'  Iterate over mapping object
     'b' adding key-value pairs to dictionary 'a'.  'b' may be a
     dictionary, or any object supporting *note PyMapping_Keys(): db7.
     and *note PyObject_GetItem(): 5ea.  If 'override' is true, existing
     pairs in 'a' will be replaced if a matching key is found in 'b',
     otherwise pairs will only be added if there is not a matching key
     in 'a'.  Return ‘0’ on success or ‘-1’ if an exception was raised.

 -- C Funzione: int PyDict_Update (PyObject *a, PyObject *b)
     ' Parte del *note ABI Stabile: 776.'  This is the same as
     ‘PyDict_Merge(a, b, 1)’ in C, and is similar to ‘a.update(b)’ in
     Python except that *note PyDict_Update(): 4f9f. doesn’t fall back
     to the iterating over a sequence of key value pairs if the second
     argument has no «keys» attribute.  Return ‘0’ on success or ‘-1’ if
     an exception was raised.

 -- C Funzione: int PyDict_MergeFromSeq2 (PyObject *a, PyObject *seq2,
          int override)
     ' Parte del *note ABI Stabile: 776.'  Update or merge into
     dictionary 'a', from the key-value pairs in 'seq2'.  'seq2' must be
     an iterable object producing iterable objects of length 2, viewed
     as key-value pairs.  In case of duplicate keys, the last wins if
     'override' is true, else the first wins.  Return ‘0’ on success or
     ‘-1’ if an exception was raised.  Equivalent Python (except for the
     return value):

          def PyDict_MergeFromSeq2(a, seq2, override):
              for key, value in seq2:
                  if override or key not in a:
                      a[key] = value

 -- C Funzione: int PyDict_AddWatcher (PyDict_WatchCallback callback)

     Register 'callback' as a dictionary watcher.  Return a non-negative
     integer id which must be passed to future calls to *note
     PyDict_Watch(): 785.  In case of error (e.g.  no more watcher IDs
     available), return ‘-1’ and set an exception.

     Added in version 3.12.

 -- C Funzione: int PyDict_ClearWatcher (int watcher_id)

     Clear watcher identified by 'watcher_id' previously returned from
     *note PyDict_AddWatcher(): 3d0.  Return ‘0’ on success, ‘-1’ on
     error (e.g.  if the given 'watcher_id' was never registered.)

     Added in version 3.12.

 -- C Funzione: int PyDict_Watch (int watcher_id, PyObject *dict)

     Mark dictionary 'dict' as watched.  The callback granted
     'watcher_id' by *note PyDict_AddWatcher(): 3d0. will be called when
     'dict' is modified or deallocated.  Return ‘0’ on success or ‘-1’
     on error.

     Added in version 3.12.

 -- C Funzione: int PyDict_Unwatch (int watcher_id, PyObject *dict)

     Mark dictionary 'dict' as no longer watched.  The callback granted
     'watcher_id' by *note PyDict_AddWatcher(): 3d0. will no longer be
     called when 'dict' is modified or deallocated.  The dict must
     previously have been watched by this watcher.  Return ‘0’ on
     success or ‘-1’ on error.

     Added in version 3.12.

 -- C Tipo: type PyDict_WatchEvent

     Enumeration of possible dictionary watcher events:
     ‘PyDict_EVENT_ADDED’, ‘PyDict_EVENT_MODIFIED’,
     ‘PyDict_EVENT_DELETED’, ‘PyDict_EVENT_CLONED’,
     ‘PyDict_EVENT_CLEARED’, or ‘PyDict_EVENT_DEALLOCATED’.

     Added in version 3.12.

 -- C Tipo: typedef int (*PyDict_WatchCallback)(*note PyDict_WatchEvent:
          5387. event, *note PyObject: 5df. *dict, *note PyObject: 5df.
          *key, *note PyObject: 5df. *new_value)

     Type of a dict watcher callback function.

     If 'event' is ‘PyDict_EVENT_CLEARED’ or ‘PyDict_EVENT_DEALLOCATED’,
     both 'key' and 'new_value' will be ‘NULL’.  If 'event' is
     ‘PyDict_EVENT_ADDED’ or ‘PyDict_EVENT_MODIFIED’, 'new_value' will
     be the new value for 'key'.  If 'event' is ‘PyDict_EVENT_DELETED’,
     'key' is being deleted from the dictionary and 'new_value' will be
     ‘NULL’.

     ‘PyDict_EVENT_CLONED’ occurs when 'dict' was previously empty and
     another dict is merged into it.  To maintain efficiency of this
     operation, per-key ‘PyDict_EVENT_ADDED’ events are not issued in
     this case; instead a single ‘PyDict_EVENT_CLONED’ is issued, and
     'key' will be the source dictionary.

     The callback may inspect but must not modify 'dict'; doing so could
     have unpredictable effects, including infinite recursion.  Do not
     trigger Python code execution in the callback, as it could modify
     the dict as a side effect.

     If 'event' is ‘PyDict_EVENT_DEALLOCATED’, taking a new reference in
     the callback to the about-to-be-destroyed dictionary will resurrect
     it and prevent it from being freed at this time.  When the
     resurrected object is destroyed later, any watcher callbacks active
     at that time will be called again.

     Callbacks occur before the notified modification to 'dict' takes
     place, so the prior state of 'dict' can be inspected.

     If the callback sets an exception, it must return ‘-1’; this
     exception will be printed as an unraisable exception using *note
     PyErr_WriteUnraisable(): 5f2.  Otherwise it should return ‘0’.

     There may already be a pending exception set on entry to the
     callback.  In this case, the callback should return ‘0’ with the
     same exception still set.  This means the callback may not call any
     other API that can set an exception unless it saves and clears the
     exception state first, and restores it before returning.

     Added in version 3.12.

* Menu:

* Dictionary View Objects::
* Ordered Dictionaries::


File: python.info,  Node: Dictionary View Objects,  Next: Ordered Dictionaries,  Up: Dictionary Objects

7.9.4.2 Dictionary View Objects
...............................

 -- C Funzione: int PyDictViewSet_Check (PyObject *op)

     Return true if 'op' is a view of a set inside a dictionary.  This
     is currently equivalent to *note PyDictKeys_Check: 538b.(*note op:
     538a.) || *note PyDictItems_Check: 538c.(*note op: 538a.).  This
     function always succeeds.

 -- C Variabile: *note PyTypeObject: c9e. PyDictKeys_Type
     ' Parte del *note ABI Stabile: 776.'  Type object for a view of
     dictionary keys.  In Python, this is the type of the object
     returned by *note dict.keys(): 9d2.

 -- C Funzione: int PyDictKeys_Check (PyObject *op)

     Return true if 'op' is an instance of a dictionary keys view.  This
     function always succeeds.

 -- C Variabile: *note PyTypeObject: c9e. PyDictValues_Type
     ' Parte del *note ABI Stabile: 776.'  Type object for a view of
     dictionary values.  In Python, this is the type of the object
     returned by *note dict.values(): 9d3.

 -- C Funzione: int PyDictValues_Check (PyObject *op)

     Return true if 'op' is an instance of a dictionary values view.
     This function always succeeds.

 -- C Variabile: *note PyTypeObject: c9e. PyDictItems_Type
     ' Parte del *note ABI Stabile: 776.'  Type object for a view of
     dictionary items.  In Python, this is the type of the object
     returned by *note dict.items(): 9d4.

 -- C Funzione: int PyDictItems_Check (PyObject *op)

     Return true if 'op' is an instance of a dictionary items view.
     This function always succeeds.


File: python.info,  Node: Ordered Dictionaries,  Prev: Dictionary View Objects,  Up: Dictionary Objects

7.9.4.3 Ordered Dictionaries
............................

Python’s C API provides interface for *note collections.OrderedDict:
7f4. from C. Since Python 3.7, dictionaries are ordered by default, so
there is usually little need for these functions; prefer ‘PyDict*’ where
possible.

 -- C Variabile: *note PyTypeObject: c9e. PyODict_Type

     Type object for ordered dictionaries.  This is the same object as
     *note collections.OrderedDict: 7f4. in the Python layer.

 -- C Funzione: int PyODict_Check (PyObject *od)

     Return true if 'od' is an ordered dictionary object or an instance
     of a subtype of the *note OrderedDict: 7f4. type.  This function
     always succeeds.

 -- C Funzione: int PyODict_CheckExact (PyObject *od)

     Return true if 'od' is an ordered dictionary object, but not an
     instance of a subtype of the *note OrderedDict: 7f4. type.  This
     function always succeeds.

 -- C Variabile: *note PyTypeObject: c9e. PyODictKeys_Type

     Analogous to *note PyDictKeys_Type: 4f8e. for ordered dictionaries.

 -- C Variabile: *note PyTypeObject: c9e. PyODictValues_Type

     Analogous to *note PyDictValues_Type: 4f94. for ordered
     dictionaries.

 -- C Variabile: *note PyTypeObject: c9e. PyODictItems_Type

     Analogous to *note PyDictItems_Type: 4f8a. for ordered
     dictionaries.

 -- C Funzione: *note PyObject: 5df. *PyODict_New (void)

     Return a new empty ordered dictionary, or ‘NULL’ on failure.

     This is analogous to *note PyDict_New(): 4f9c.

 -- C Funzione: int PyODict_SetItem (PyObject *od, PyObject *key,
          PyObject *value)

     Insert 'value' into the ordered dictionary 'od' with a key of
     'key'.  Return ‘0’ on success or ‘-1’ with an exception set on
     failure.

     This is analogous to *note PyDict_SetItem(): 4ea2.

 -- C Funzione: int PyODict_DelItem (PyObject *od, PyObject *key)

     Remove the entry in the ordered dictionary 'od' with key 'key'.
     Return ‘0’ on success or ‘-1’ with an exception set on failure.

     This is analogous to *note PyDict_DelItem(): 4f96.

These are *note soft deprecated: 23d. aliases to ‘PyDict’ APIs:

‘PyODict’                                              ‘PyDict’
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
 -- C Macro: PyODict_GetItem (od, key)                 *note PyDict_GetItem(): 628.
                                                       
                                                       
 -- C Macro: PyODict_GetItemWithError (od, key)        *note PyDict_GetItemWithError(): 5e1.
                                                       
                                                       
 -- C Macro: PyODict_GetItemString (od, key)           *note PyDict_GetItemString(): 629.
                                                       
                                                       
 -- C Macro: PyODict_Contains (od, key)                *note PyDict_Contains(): 5de.
                                                       
                                                       
 -- C Macro: PyODict_Size (od)                         *note PyDict_Size(): 4f9d.
                                                       
                                                       
 -- C Macro: PyODict_SIZE (od)                         *note PyDict_GET_SIZE(): 5383.
                                                       


File: python.info,  Node: Set Objects,  Prev: Dictionary Objects,  Up: Container Objects

7.9.4.4 Set Objects
...................

This section details the public API for *note set: 184. and *note
frozenset: 7f3. objects.  Any functionality not listed below is best
accessed using either the abstract object protocol (including *note
PyObject_CallMethod(): 640, *note PyObject_RichCompareBool(): 1d74,
*note PyObject_Hash(): 436, *note PyObject_Repr(): 1231, *note
PyObject_IsTrue(): 506b, *note PyObject_Print(): 1973, and *note
PyObject_GetIter(): 506a.) or the abstract number protocol (including
*note PyNumber_And(): 503e, *note PyNumber_Subtract(): 5057, *note
PyNumber_Or(): 5052, *note PyNumber_Xor(): 5059, *note
PyNumber_InPlaceAnd(): 5043, *note PyNumber_InPlaceSubtract(): 504b,
*note PyNumber_InPlaceOr(): 5047, and *note PyNumber_InPlaceXor():
504d.).

 -- C Tipo: type PySetObject

     This subtype of *note PyObject: 5df. is used to hold the internal
     data for both *note set: 184. and *note frozenset: 7f3. objects.
     It is like a *note PyDictObject: 64f. in that it is a fixed size
     for small sets (much like tuple storage) and will point to a
     separate, variable sized block of memory for medium and large sized
     sets (much like list storage).  None of the fields of this
     structure should be considered public and all are subject to
     change.  All access should be done through the documented API
     rather than by manipulating the values in the structure.

 -- C Variabile: *note PyTypeObject: c9e. PySet_Type
     ' Parte del *note ABI Stabile: 776.'  This is an instance of *note
     PyTypeObject: c9e. representing the Python *note set: 184. type.

 -- C Variabile: *note PyTypeObject: c9e. PyFrozenSet_Type
     ' Parte del *note ABI Stabile: 776.'  This is an instance of *note
     PyTypeObject: c9e. representing the Python *note frozenset: 7f3.
     type.

The following type check macros work on pointers to any Python object.
Likewise, the constructor functions work with any iterable Python
object.

 -- C Funzione: int PySet_Check (PyObject *p)

     Return true if 'p' is a *note set: 184. object or an instance of a
     subtype.  This function always succeeds.

 -- C Funzione: int PyFrozenSet_Check (PyObject *p)

     Return true if 'p' is a *note frozenset: 7f3. object or an instance
     of a subtype.  This function always succeeds.

 -- C Funzione: int PyAnySet_Check (PyObject *p)

     Return true if 'p' is a *note set: 184. object, a *note frozenset:
     7f3. object, or an instance of a subtype.  This function always
     succeeds.

 -- C Funzione: int PySet_CheckExact (PyObject *p)

     Return true if 'p' is a *note set: 184. object but not an instance
     of a subtype.  This function always succeeds.

     Added in version 3.10.

 -- C Funzione: int PyAnySet_CheckExact (PyObject *p)

     Return true if 'p' is a *note set: 184. object or a *note
     frozenset: 7f3. object but not an instance of a subtype.  This
     function always succeeds.

 -- C Funzione: int PyFrozenSet_CheckExact (PyObject *p)

     Return true if 'p' is a *note frozenset: 7f3. object but not an
     instance of a subtype.  This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PySet_New (PyObject *iterable)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new *note set: 184. containing objects
     returned by the 'iterable'.  The 'iterable' may be ‘NULL’ to create
     a new empty set.  Return the new set on success or ‘NULL’ on
     failure.  Raise *note TypeError: 198. if 'iterable' is not actually
     iterable.  The constructor is also useful for copying a set
     (‘c=set(s)’).

 -- C Funzione: *note PyObject: 5df. *PyFrozenSet_New (PyObject
          *iterable)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new *note frozenset: 7f3. containing
     objects returned by the 'iterable'.  The 'iterable' may be ‘NULL’
     to create a new empty frozenset.  Return the new set on success or
     ‘NULL’ on failure.  Raise *note TypeError: 198. if 'iterable' is
     not actually iterable.

The following functions and macros are available for instances of *note
set: 184. or *note frozenset: 7f3. or instances of their subtypes.

 -- C Funzione: *note Py_ssize_t: c57. PySet_Size (PyObject *anyset)
     ' Parte del *note ABI Stabile: 776.'

     Return the length of a *note set: 184. or *note frozenset: 7f3.
     object.  Equivalent to ‘len(anyset)’.  Raises a *note SystemError:
     796. if 'anyset' is not a *note set: 184, *note frozenset: 7f3, or
     an instance of a subtype.

 -- C Funzione: *note Py_ssize_t: c57. PySet_GET_SIZE (PyObject *anyset)

     Macro form of *note PySet_Size(): 1650. without error checking.

 -- C Funzione: int PySet_Contains (PyObject *anyset, PyObject *key)
     ' Parte del *note ABI Stabile: 776.'  Return ‘1’ if found, ‘0’ if
     not found, and ‘-1’ if an error is encountered.  Unlike the Python
     *note __contains__(): 15c1. method, this function does not
     automatically convert unhashable sets into temporary frozensets.
     Raise a *note TypeError: 198. if the 'key' is unhashable.  Raise
     *note SystemError: 796. if 'anyset' is not a *note set: 184, *note
     frozenset: 7f3, or an instance of a subtype.

 -- C Funzione: int PySet_Add (PyObject *set, PyObject *key)
     ' Parte del *note ABI Stabile: 776.'  Add 'key' to a *note set:
     184. instance.  Also works with *note frozenset: 7f3. instances
     (like *note PyTuple_SetItem(): 4ea1. it can be used to fill in the
     values of brand new frozensets before they are exposed to other
     code).  Return ‘0’ on success or ‘-1’ on failure.  Raise a *note
     TypeError: 198. if the 'key' is unhashable.  Raise a *note
     MemoryError: 1786. if there is no room to grow.  Raise a *note
     SystemError: 796. if 'set' is not an instance of *note set: 184. or
     its subtype.

The following functions are available for instances of *note set: 184.
or its subtypes but not for instances of *note frozenset: 7f3. or its
subtypes.

 -- C Funzione: int PySet_Discard (PyObject *set, PyObject *key)
     ' Parte del *note ABI Stabile: 776.'  Return ‘1’ if found and
     removed, ‘0’ if not found (no action taken), and ‘-1’ if an error
     is encountered.  Does not raise *note KeyError: 5e7. for missing
     keys.  Raise a *note TypeError: 198. if the 'key' is unhashable.
     Unlike the Python *note discard(): 2684. method, this function does
     not automatically convert unhashable sets into temporary
     frozensets.  Raise *note SystemError: 796. if 'set' is not an
     instance of *note set: 184. or its subtype.

 -- C Funzione: *note PyObject: 5df. *PySet_Pop (PyObject *set)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new reference to an arbitrary object in
     the 'set', and removes the object from the 'set'.  Return ‘NULL’ on
     failure.  Raise *note KeyError: 5e7. if the set is empty.  Raise a
     *note SystemError: 796. if 'set' is not an instance of *note set:
     184. or its subtype.

 -- C Funzione: int PySet_Clear (PyObject *set)
     ' Parte del *note ABI Stabile: 776.'  Empty an existing set of all
     elements.  Return ‘0’ on success.  Return ‘-1’ and raise *note
     SystemError: 796. if 'set' is not an instance of *note set: 184. or
     its subtype.

* Menu:

* Deprecated API: Deprecated API<3>.


File: python.info,  Node: Deprecated API<3>,  Up: Set Objects

7.9.4.5 Deprecated API
......................

 -- C Macro: PySet_MINSIZE

     A *note soft deprecated: 23d. constant representing the size of an
     internal preallocated table inside *note PySetObject: 53a2.
     instances.

     This is documented solely for completeness, as there are no
     guarantees that a given version of CPython uses preallocated tables
     with a fixed size.  In code that does not deal with unstable set
     internals, ‘PySet_MINSIZE’ can be replaced with a small constant
     like ‘8’.

     If looking for the size of a set, use *note PySet_Size(): 1650.
     instead.


File: python.info,  Node: Function Objects<2>,  Next: Other Objects,  Prev: Container Objects,  Up: Concrete Objects Layer

7.9.5 Function Objects
----------------------

* Menu:

* Function Objects: Function Objects<3>.
* Instance Method Objects::
* Method Objects::
* Cell Objects::
* Code Objects::
* Code Object Flags::
* Extra information::


File: python.info,  Node: Function Objects<3>,  Next: Instance Method Objects,  Up: Function Objects<2>

7.9.5.1 Function Objects
........................

There are a few functions specific to Python functions.

 -- C Tipo: type PyFunctionObject

     The C structure used for functions.

 -- C Variabile: *note PyTypeObject: c9e. PyFunction_Type

     This is an instance of *note PyTypeObject: c9e. and represents the
     Python function type.  It is exposed to Python programmers as
     ‘types.FunctionType’.

 -- C Funzione: int PyFunction_Check (PyObject *o)

     Return true if 'o' is a function object (has type *note
     PyFunction_Type: 53b0.).  The parameter must not be ‘NULL’.  This
     function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyFunction_New (PyObject *code,
          PyObject *globals)
     'Valore di ritorno: Nuovo riferimento.'  Return a new function
     object associated with the code object 'code'.  'globals' must be a
     dictionary with the global variables accessible to the function.

     The function’s docstring and name are retrieved from the code
     object.  *note __module__: 2331. is retrieved from 'globals'.  The
     argument defaults, annotations and closure are set to ‘NULL’.
     *note __qualname__: 2330. is set to the same value as the code
     object’s *note co_qualname: 236c. field.

 -- C Funzione: *note PyObject: 5df. *PyFunction_NewWithQualName
          (PyObject *code, PyObject *globals, PyObject *qualname)
     'Valore di ritorno: Nuovo riferimento.'  As *note PyFunction_New():
     53b2, but also allows setting the function object’s *note
     __qualname__: 2330. attribute.  'qualname' should be a unicode
     object or ‘NULL’; if ‘NULL’, the ‘__qualname__’ attribute is set to
     the same value as the code object’s *note co_qualname: 236c. field.

     Added in version 3.3.

 -- C Funzione: *note PyObject: 5df. *PyFunction_GetCode (PyObject *op)
     'Valore di ritorno: Riferimento preso in prestito.'  Return the
     code object associated with the function object 'op'.

 -- C Funzione: *note PyObject: 5df. *PyFunction_GetGlobals (PyObject
          *op)
     'Valore di ritorno: Riferimento preso in prestito.'  Return the
     globals dictionary associated with the function object 'op'.

 -- C Funzione: *note PyObject: 5df. *PyFunction_GetModule (PyObject
          *op)
     'Valore di ritorno: Riferimento preso in prestito.'  Return a *note
     borrowed reference: 3d7. to the *note __module__: 2331. attribute
     of the *note function object: 59c. 'op'.  It can be 'NULL'.

     This is normally a *note string: 169. containing the module name,
     but can be set to any other object by Python code.

 -- C Funzione: *note PyObject: 5df. *PyFunction_GetDefaults (PyObject
          *op)
     'Valore di ritorno: Riferimento preso in prestito.'  Return the
     argument default values of the function object 'op'.  This can be a
     tuple of arguments or ‘NULL’.

 -- C Funzione: int PyFunction_SetDefaults (PyObject *op, PyObject
          *defaults)

     Set the argument default values for the function object 'op'.
     'defaults' must be ‘Py_None’ or a tuple.

     Raises *note SystemError: 796. and returns ‘-1’ on failure.

 -- C Funzione: void PyFunction_SetVectorcall (PyFunctionObject *func,
          vectorcallfunc vectorcall)

     Set the vectorcall field of a given function object 'func'.

     Warning: extensions using this API must preserve the behavior of
     the unaltered (default) vectorcall function!

     Added in version 3.12.

 -- C Funzione: *note PyObject: 5df. *PyFunction_GetKwDefaults (PyObject
          *op)
     'Valore di ritorno: Riferimento preso in prestito.'  Return the
     keyword-only argument default values of the function object 'op'.
     This can be a dictionary of arguments or ‘NULL’.

 -- C Funzione: int PyFunction_SetKwDefaults (PyObject *op, PyObject
          *defaults)

     Set the keyword-only argument default values of the function object
     'op'.  'defaults' must be a dictionary of keyword-only arguments or
     ‘Py_None’.

     This function returns ‘0’ on success, and returns ‘-1’ with an
     exception set on failure.

 -- C Funzione: *note PyObject: 5df. *PyFunction_GetClosure (PyObject
          *op)
     'Valore di ritorno: Riferimento preso in prestito.'  Return the
     closure associated with the function object 'op'.  This can be
     ‘NULL’ or a tuple of cell objects.

 -- C Funzione: int PyFunction_SetClosure (PyObject *op, PyObject
          *closure)

     Set the closure associated with the function object 'op'.
     'closure' must be ‘Py_None’ or a tuple of cell objects.

     Raises *note SystemError: 796. and returns ‘-1’ on failure.

 -- C Funzione: *note PyObject: 5df. *PyFunction_GetAnnotations
          (PyObject *op)
     'Valore di ritorno: Riferimento preso in prestito.'  Return the
     annotations of the function object 'op'.  This can be a mutable
     dictionary or ‘NULL’.

 -- C Funzione: int PyFunction_SetAnnotations (PyObject *op, PyObject
          *annotations)

     Set the annotations for the function object 'op'.  'annotations'
     must be a dictionary or ‘Py_None’.

     Raises *note SystemError: 796. and returns ‘-1’ on failure.

 -- C Funzione: *note PyObject: 5df. *PyFunction_GET_CODE (PyObject *op)
 -- C Funzione: *note PyObject: 5df. *PyFunction_GET_GLOBALS (PyObject
          *op)
 -- C Funzione: *note PyObject: 5df. *PyFunction_GET_MODULE (PyObject
          *op)
 -- C Funzione: *note PyObject: 5df. *PyFunction_GET_DEFAULTS (PyObject
          *op)
 -- C Funzione: *note PyObject: 5df. *PyFunction_GET_KW_DEFAULTS
          (PyObject *op)
 -- C Funzione: *note PyObject: 5df. *PyFunction_GET_CLOSURE (PyObject
          *op)
 -- C Funzione: *note PyObject: 5df. *PyFunction_GET_ANNOTATIONS
          (PyObject *op)
     'Valore di ritorno: Riferimento preso in prestito.'  These
     functions are similar to their ‘PyFunction_Get*’ counterparts, but
     do not do type checking.  Passing anything other than an instance
     of *note PyFunction_Type: 53b0. is undefined behavior.

 -- C Funzione: int PyFunction_AddWatcher (PyFunction_WatchCallback
          callback)

     Register 'callback' as a function watcher for the current
     interpreter.  Return an ID which may be passed to *note
     PyFunction_ClearWatcher(): 53c6.  In case of error (e.g.  no more
     watcher IDs available), return ‘-1’ and set an exception.

     Added in version 3.12.

 -- C Funzione: int PyFunction_ClearWatcher (int watcher_id)

     Clear watcher identified by 'watcher_id' previously returned from
     *note PyFunction_AddWatcher(): 53c5. for the current interpreter.
     Return ‘0’ on success, or ‘-1’ and set an exception on error (e.g.
     if the given 'watcher_id' was never registered.)

     Added in version 3.12.

 -- C Tipo: type PyFunction_WatchEvent

          Enumeration of possible function watcher events:

             - ‘PyFunction_EVENT_CREATE’

             - ‘PyFunction_EVENT_DESTROY’

             - ‘PyFunction_EVENT_MODIFY_CODE’

             - ‘PyFunction_EVENT_MODIFY_DEFAULTS’

             - ‘PyFunction_EVENT_MODIFY_KWDEFAULTS’

     Added in version 3.12.

 -- C Tipo: typedef int (*PyFunction_WatchCallback)(*note
          PyFunction_WatchEvent: 53c7. event, *note PyFunctionObject:
          784. *func, *note PyObject: 5df. *new_value)

     Type of a function watcher callback function.

     If 'event' is ‘PyFunction_EVENT_CREATE’ or
     ‘PyFunction_EVENT_DESTROY’ then 'new_value' will be ‘NULL’.
     Otherwise, 'new_value' will hold a *note borrowed reference: 3d7.
     to the new value that is about to be stored in 'func' for the
     attribute that is being modified.

     The callback may inspect but must not modify 'func'; doing so could
     have unpredictable effects, including infinite recursion.

     If 'event' is ‘PyFunction_EVENT_CREATE’, then the callback is
     invoked after 'func' has been fully initialized.  Otherwise, the
     callback is invoked before the modification to 'func' takes place,
     so the prior state of 'func' can be inspected.  The runtime is
     permitted to optimize away the creation of function objects when
     possible.  In such cases no event will be emitted.  Although this
     creates the possibility of an observable difference of runtime
     behavior depending on optimization decisions, it does not change
     the semantics of the Python code being executed.

     If 'event' is ‘PyFunction_EVENT_DESTROY’, Taking a reference in the
     callback to the about-to-be-destroyed function will resurrect it,
     preventing it from being freed at this time.  When the resurrected
     object is destroyed later, any watcher callbacks active at that
     time will be called again.

     If the callback sets an exception, it must return ‘-1’; this
     exception will be printed as an unraisable exception using *note
     PyErr_WriteUnraisable(): 5f2.  Otherwise it should return ‘0’.

     There may already be a pending exception set on entry to the
     callback.  In this case, the callback should return ‘0’ with the
     same exception still set.  This means the callback may not call any
     other API that can set an exception unless it saves and clears the
     exception state first, and restores it before returning.

     Added in version 3.12.


File: python.info,  Node: Instance Method Objects,  Next: Method Objects,  Prev: Function Objects<3>,  Up: Function Objects<2>

7.9.5.2 Instance Method Objects
...............................

An instance method is a wrapper for a *note PyCFunction: 167f. and the
new way to bind a *note PyCFunction: 167f. to a class object.  It
replaces the former call ‘PyMethod_New(func, NULL, class)’.

 -- C Variabile: *note PyTypeObject: c9e. PyInstanceMethod_Type

     This instance of *note PyTypeObject: c9e. represents the Python
     instance method type.  It is not exposed to Python programs.

 -- C Funzione: int PyInstanceMethod_Check (PyObject *o)

     Return true if 'o' is an instance method object (has type *note
     PyInstanceMethod_Type: 53cd.).  The parameter must not be ‘NULL’.
     This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyInstanceMethod_New (PyObject
          *func)
     'Valore di ritorno: Nuovo riferimento.'  Return a new instance
     method object, with 'func' being any callable object.  'func' is
     the function that will be called when the instance method is
     called.

 -- C Funzione: *note PyObject: 5df. *PyInstanceMethod_Function
          (PyObject *im)
     'Valore di ritorno: Riferimento preso in prestito.'  Return the
     function object associated with the instance method 'im'.

 -- C Funzione: *note PyObject: 5df. *PyInstanceMethod_GET_FUNCTION
          (PyObject *im)
     'Valore di ritorno: Riferimento preso in prestito.'  Macro version
     of *note PyInstanceMethod_Function(): 53d0. which avoids error
     checking.


File: python.info,  Node: Method Objects,  Next: Cell Objects,  Prev: Instance Method Objects,  Up: Function Objects<2>

7.9.5.3 Method Objects
......................

Methods are bound function objects.  Methods are always bound to an
instance of a user-defined class.  Unbound methods (methods bound to a
class object) are no longer available.

 -- C Variabile: *note PyTypeObject: c9e. PyMethod_Type

     This instance of *note PyTypeObject: c9e. represents the Python
     method type.  This is exposed to Python programs as
     ‘types.MethodType’.

 -- C Funzione: int PyMethod_Check (PyObject *o)

     Return true if 'o' is a method object (has type *note
     PyMethod_Type: 53d4.).  The parameter must not be ‘NULL’.  This
     function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyMethod_New (PyObject *func,
          PyObject *self)
     'Valore di ritorno: Nuovo riferimento.'  Return a new method
     object, with 'func' being any callable object and 'self' the
     instance the method should be bound.  'func' is the function that
     will be called when the method is called.  'self' must not be
     ‘NULL’.

 -- C Funzione: *note PyObject: 5df. *PyMethod_Function (PyObject *meth)
     'Valore di ritorno: Riferimento preso in prestito.'  Return the
     function object associated with the method 'meth'.

 -- C Funzione: *note PyObject: 5df. *PyMethod_GET_FUNCTION (PyObject
          *meth)
     'Valore di ritorno: Riferimento preso in prestito.'  Macro version
     of *note PyMethod_Function(): 53d7. which avoids error checking.

 -- C Funzione: *note PyObject: 5df. *PyMethod_Self (PyObject *meth)
     'Valore di ritorno: Riferimento preso in prestito.'  Return the
     instance associated with the method 'meth'.

 -- C Funzione: *note PyObject: 5df. *PyMethod_GET_SELF (PyObject *meth)
     'Valore di ritorno: Riferimento preso in prestito.'  Macro version
     of *note PyMethod_Self(): 53d9. which avoids error checking.


File: python.info,  Node: Cell Objects,  Next: Code Objects,  Prev: Method Objects,  Up: Function Objects<2>

7.9.5.4 Cell Objects
....................

«Cell» objects are used to implement variables referenced by multiple
scopes.  For each such variable, a cell object is created to store the
value; the local variables of each stack frame that references the value
contain a reference to the cells from outer scopes which also use that
variable.  When the value is accessed, the value contained in the cell
is used instead of the cell object itself.  This de-referencing of the
cell object requires support from the generated byte-code; these are not
automatically de-referenced when accessed.  Cell objects are not likely
to be useful elsewhere.

 -- C Tipo: type PyCellObject

     The C structure used for cell objects.

 -- C Variabile: *note PyTypeObject: c9e. PyCell_Type

     The type object corresponding to cell objects.

 -- C Funzione: int PyCell_Check (PyObject *ob)

     Return true if 'ob' is a cell object; 'ob' must not be ‘NULL’.
     This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyCell_New (PyObject *ob)
     'Valore di ritorno: Nuovo riferimento.'  Create and return a new
     cell object containing the value 'ob'.  The parameter may be
     ‘NULL’.

 -- C Funzione: *note PyObject: 5df. *PyCell_Get (PyObject *cell)
     'Valore di ritorno: Nuovo riferimento.'  Return the contents of the
     cell 'cell', which can be ‘NULL’.  If 'cell' is not a cell object,
     returns ‘NULL’ with an exception set.

 -- C Funzione: *note PyObject: 5df. *PyCell_GET (PyObject *cell)
     'Valore di ritorno: Riferimento preso in prestito.'  Return the
     contents of the cell 'cell', but without checking that 'cell' is
     non-‘NULL’ and a cell object.

 -- C Funzione: int PyCell_Set (PyObject *cell, PyObject *value)

     Set the contents of the cell object 'cell' to 'value'.  This
     releases the reference to any current content of the cell.  'value'
     may be ‘NULL’.  'cell' must be non-‘NULL’.

     On success, return ‘0’.  If 'cell' is not a cell object, set an
     exception and return ‘-1’.

 -- C Funzione: void PyCell_SET (PyObject *cell, PyObject *value)

     Sets the value of the cell object 'cell' to 'value'.  No reference
     counts are adjusted, and no checks are made for safety; 'cell' must
     be non-‘NULL’ and must be a cell object.


File: python.info,  Node: Code Objects,  Next: Code Object Flags,  Prev: Cell Objects,  Up: Function Objects<2>

7.9.5.5 Code Objects
....................

Code objects are a low-level detail of the CPython implementation.  Each
one represents a chunk of executable code that hasn’t yet been bound
into a function.

 -- C Tipo: type PyCodeObject

     The C structure of the objects used to describe code objects.  The
     fields of this type are subject to change at any time.

 -- C Variabile: *note PyTypeObject: c9e. PyCode_Type

     This is an instance of *note PyTypeObject: c9e. representing the
     Python *note code object: 4e7.

 -- C Funzione: int PyCode_Check (PyObject *co)

     Return true if 'co' is a *note code object: 4e7.  This function
     always succeeds.

 -- C Funzione: *note Py_ssize_t: c57. PyCode_GetNumFree (PyCodeObject
          *co)

     Return the number of *note free (closure) variables: 187b. in a
     code object.

 -- C Funzione: int PyUnstable_Code_GetFirstFree (PyCodeObject *co)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Return the position of the first *note free (closure) variable:
     187b. in a code object.

     Cambiato nella versione 3.13: Renamed from ‘PyCode_GetFirstFree’ as
     part of *note Unstable C API: 76a.  The old name is deprecated, but
     will remain available until the signature changes again.

 -- C Funzione: *note PyCodeObject: 97c. *PyUnstable_Code_New (int
          argcount, int kwonlyargcount, int nlocals, int stacksize, int
          flags, PyObject *code, PyObject *consts, PyObject *names,
          PyObject *varnames, PyObject *freevars, PyObject *cellvars,
          PyObject *filename, PyObject *name, PyObject *qualname, int
          firstlineno, PyObject *linetable, PyObject *exceptiontable)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Return a new code object.  If you need a dummy code object to
     create a frame, use *note PyCode_NewEmpty(): 1558. instead.

     Since the definition of the bytecode changes often, calling *note
     PyUnstable_Code_New(): 53eb. directly can bind you to a precise
     Python version.

     The many arguments of this function are inter-dependent in complex
     ways, meaning that subtle changes to values are likely to result in
     incorrect execution or VM crashes.  Use this function only with
     extreme care.

     Cambiato nella versione 3.11: Added ‘qualname’ and ‘exceptiontable’
     parameters.

     Cambiato nella versione 3.12: Renamed from ‘PyCode_New’ as part of
     *note Unstable C API: 76a.  The old name is deprecated, but will
     remain available until the signature changes again.

 -- C Funzione: *note PyCodeObject: 97c.
          *PyUnstable_Code_NewWithPosOnlyArgs (int argcount, int
          posonlyargcount, int kwonlyargcount, int nlocals, int
          stacksize, int flags, PyObject *code, PyObject *consts,
          PyObject *names, PyObject *varnames, PyObject *freevars,
          PyObject *cellvars, PyObject *filename, PyObject *name,
          PyObject *qualname, int firstlineno, PyObject *linetable,
          PyObject *exceptiontable)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Similar to *note PyUnstable_Code_New(): 53eb, but with an extra
     «posonlyargcount» for positional-only arguments.  The same caveats
     that apply to ‘PyUnstable_Code_New’ also apply to this function.

     Added in version 3.8: as ‘PyCode_NewWithPosOnlyArgs’

     Cambiato nella versione 3.11: Added ‘qualname’ and ‘exceptiontable’
     parameters.

     Cambiato nella versione 3.12: Renamed to
     ‘PyUnstable_Code_NewWithPosOnlyArgs’.  The old name is deprecated,
     but will remain available until the signature changes again.

 -- C Funzione: *note PyCodeObject: 97c. *PyCode_NewEmpty (const char
          *filename, const char *funcname, int firstlineno)
     'Valore di ritorno: Nuovo riferimento.'  Return a new empty code
     object with the specified filename, function name, and first line
     number.  The resulting code object will raise an ‘Exception’ if
     executed.

 -- C Funzione: int PyCode_Addr2Line (PyCodeObject *co, int byte_offset)

     Return the line number of the instruction that occurs on or before
     ‘byte_offset’ and ends after it.  If you just need the line number
     of a frame, use *note PyFrame_GetLineNumber(): 98f. instead.

     For efficiently iterating over the line numbers in a code object,
     use the API described in PEP 626(1).

 -- C Funzione: int PyCode_Addr2Location (PyObject *co, int byte_offset,
          int *start_line, int *start_column, int *end_line, int
          *end_column)

     Sets the passed ‘int’ pointers to the source code line and column
     numbers for the instruction at ‘byte_offset’.  Sets the value to
     ‘0’ when information is not available for any particular element.

     Returns ‘1’ if the function succeeds and 0 otherwise.

     Added in version 3.11.

 -- C Funzione: *note PyObject: 5df. *PyCode_GetCode (PyCodeObject *co)

     Equivalent to the Python code ‘getattr(co, 'co_code')’.  Returns a
     strong reference to a *note PyBytesObject: 996. representing the
     bytecode in a code object.  On error, ‘NULL’ is returned and an
     exception is raised.

     This ‘PyBytesObject’ may be created on-demand by the interpreter
     and does not necessarily represent the bytecode actually executed
     by CPython.  The primary use case for this function is debuggers
     and profilers.

     Added in version 3.11.

 -- C Funzione: *note PyObject: 5df. *PyCode_GetVarnames (PyCodeObject
          *co)

     Equivalent to the Python code ‘getattr(co, 'co_varnames')’.
     Returns a new reference to a *note PyTupleObject: 51fc. containing
     the names of the local variables.  On error, ‘NULL’ is returned and
     an exception is raised.

     Added in version 3.11.

 -- C Funzione: *note PyObject: 5df. *PyCode_GetCellvars (PyCodeObject
          *co)

     Equivalent to the Python code ‘getattr(co, 'co_cellvars')’.
     Returns a new reference to a *note PyTupleObject: 51fc. containing
     the names of the local variables that are referenced by nested
     functions.  On error, ‘NULL’ is returned and an exception is
     raised.

     Added in version 3.11.

 -- C Funzione: *note PyObject: 5df. *PyCode_GetFreevars (PyCodeObject
          *co)

     Equivalent to the Python code ‘getattr(co, 'co_freevars')’.
     Returns a new reference to a *note PyTupleObject: 51fc. containing
     the names of the *note free (closure) variables: 187b.  On error,
     ‘NULL’ is returned and an exception is raised.

     Added in version 3.11.

 -- C Funzione: int PyCode_AddWatcher (PyCode_WatchCallback callback)

     Register 'callback' as a code object watcher for the current
     interpreter.  Return an ID which may be passed to *note
     PyCode_ClearWatcher(): 789.  In case of error (e.g.  no more
     watcher IDs available), return ‘-1’ and set an exception.

     Added in version 3.12.

 -- C Funzione: int PyCode_ClearWatcher (int watcher_id)

     Clear watcher identified by 'watcher_id' previously returned from
     *note PyCode_AddWatcher(): 788. for the current interpreter.
     Return ‘0’ on success, or ‘-1’ and set an exception on error (e.g.
     if the given 'watcher_id' was never registered.)

     Added in version 3.12.

 -- C Tipo: type PyCodeEvent

     Enumeration of possible code object watcher events: -
     ‘PY_CODE_EVENT_CREATE’ - ‘PY_CODE_EVENT_DESTROY’

     Added in version 3.12.

 -- C Tipo: typedef int (*PyCode_WatchCallback)(*note PyCodeEvent: 53ee.
          event, *note PyCodeObject: 97c. *co)

     Type of a code object watcher callback function.

     If 'event' is ‘PY_CODE_EVENT_CREATE’, then the callback is invoked
     after 'co' has been fully initialized.  Otherwise, the callback is
     invoked before the destruction of 'co' takes place, so the prior
     state of 'co' can be inspected.

     If 'event' is ‘PY_CODE_EVENT_DESTROY’, taking a reference in the
     callback to the about-to-be-destroyed code object will resurrect it
     and prevent it from being freed at this time.  When the resurrected
     object is destroyed later, any watcher callbacks active at that
     time will be called again.

     Users of this API should not rely on internal runtime
     implementation details.  Such details may include, but are not
     limited to, the exact order and timing of creation and destruction
     of code objects.  While changes in these details may result in
     differences observable by watchers (including whether a callback is
     invoked or not), it does not change the semantics of the Python
     code being executed.

     If the callback sets an exception, it must return ‘-1’; this
     exception will be printed as an unraisable exception using *note
     PyErr_WriteUnraisable(): 5f2.  Otherwise it should return ‘0’.

     There may already be a pending exception set on entry to the
     callback.  In this case, the callback should return ‘0’ with the
     same exception still set.  This means the callback may not call any
     other API that can set an exception unless it saves and clears the
     exception state first, and restores it before returning.

     Added in version 3.12.

 -- C Funzione: *note PyObject: 5df. *PyCode_Optimize (PyObject *code,
          PyObject *consts, PyObject *names, PyObject *lnotab_obj)

     This is a *note soft deprecated: 23d. function that does nothing.

     Prior to Python 3.10, this function would perform basic
     optimizations to a code object.

     Cambiato nella versione 3.10: This function now does nothing.

   ---------- Footnotes ----------

   (1) 
https://peps.python.org/pep-0626/#out-of-process-debuggers-and-profilers


File: python.info,  Node: Code Object Flags,  Next: Extra information,  Prev: Code Objects,  Up: Function Objects<2>

7.9.5.6 Code Object Flags
.........................

Code objects contain a bit-field of flags, which can be retrieved as the
*note co_flags: 18c3. Python attribute (for example using *note
PyObject_GetAttrString(): 5ef.), and set using a 'flags' argument to
*note PyUnstable_Code_New(): 53eb. and similar functions.

Flags whose names start with ‘CO_FUTURE_’ correspond to features
normally selectable by *note future statements: 45d.  These flags can be
used in *note PyCompilerFlags.cf_flags: 51b2.  Note that many
‘CO_FUTURE_’ flags are mandatory in current versions of Python, and
setting them has no effect.

The following flags are available.  For their meaning, see the linked
documentation of their Python equivalents.

Flag                                                   Meaning
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
 -- C Macro: CO_OPTIMIZED                              *note inspect.CO_OPTIMIZED: 4a3b.
                                                       
                                                       
 -- C Macro: CO_NEWLOCALS                              *note inspect.CO_NEWLOCALS: 4a3c.
                                                       
                                                       
 -- C Macro: CO_VARARGS                                *note inspect.CO_VARARGS: 4a3d.
                                                       
                                                       
 -- C Macro: CO_VARKEYWORDS                            *note inspect.CO_VARKEYWORDS: 4a3e.
                                                       
                                                       
 -- C Macro: CO_NESTED                                 *note inspect.CO_NESTED: 4a3f.
                                                       
                                                       
 -- C Macro: CO_GENERATOR                              *note inspect.CO_GENERATOR: 4a40.
                                                       
                                                       
 -- C Macro: CO_COROUTINE                              *note inspect.CO_COROUTINE: 4a41.
                                                       
                                                       
 -- C Macro: CO_ITERABLE_COROUTINE                     *note inspect.CO_ITERABLE_COROUTINE: 4a42.
                                                       
                                                       
 -- C Macro: CO_ASYNC_GENERATOR                        *note inspect.CO_ASYNC_GENERATOR: 4a43.
                                                       
                                                       
 -- C Macro: CO_HAS_DOCSTRING                          *note inspect.CO_HAS_DOCSTRING: 237a.
                                                       
                                                       
 -- C Macro: CO_METHOD                                 *note inspect.CO_METHOD: 4a44.
                                                       
                                                       
 -- C Macro: CO_FUTURE_DIVISION                        no effect (*note __future__.division: 49e9.)
                                                       
                                                       
 -- C Macro: CO_FUTURE_ABSOLUTE_IMPORT                 no effect (*note __future__.absolute_import: 49ea.)
                                                       
                                                       
 -- C Macro: CO_FUTURE_WITH_STATEMENT                  no effect (*note __future__.with_statement: 49eb.)
                                                       
                                                       
 -- C Macro: CO_FUTURE_PRINT_FUNCTION                  no effect (*note __future__.print_function: 49ec.)
                                                       
                                                       
 -- C Macro: CO_FUTURE_UNICODE_LITERALS                no effect (*note __future__.unicode_literals: 49ed.)
                                                       
                                                       
 -- C Macro: CO_FUTURE_GENERATOR_STOP                  no effect (*note __future__.generator_stop: 49ee.)
                                                       
                                                       
 -- C Macro: CO_FUTURE_ANNOTATIONS                     *note __future__.annotations: 49ef.
                                                       


File: python.info,  Node: Extra information,  Prev: Code Object Flags,  Up: Function Objects<2>

7.9.5.7 Extra information
.........................

To support low-level extensions to frame evaluation, such as external
just-in-time compilers, it is possible to attach arbitrary extra data to
code objects.

These functions are part of the unstable C API tier: this functionality
is a CPython implementation detail, and the API may change without
deprecation warnings.

 -- C Funzione: *note Py_ssize_t: c57.
          PyUnstable_Eval_RequestCodeExtraIndex (freefunc free)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Return a new opaque index value used to adding data to code
     objects.

     You generally call this function once (per interpreter) and use the
     result with ‘PyCode_GetExtra’ and ‘PyCode_SetExtra’ to manipulate
     data on individual code objects.

     If 'free' is not ‘NULL’: when a code object is deallocated, 'free'
     will be called on non-‘NULL’ data stored under the new index.  Use
     *note Py_DecRef(): 5102. when storing *note PyObject: 5df.

     Added in version 3.6: as ‘_PyEval_RequestCodeExtraIndex’

     Cambiato nella versione 3.12: Renamed to
     ‘PyUnstable_Eval_RequestCodeExtraIndex’.  The old private name is
     deprecated, but will be available until the API changes.

 -- C Funzione: int PyUnstable_Code_GetExtra (PyObject *code, Py_ssize_t
          index, void **extra)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Set 'extra' to the extra data stored under the given index.  Return
     0 on success.  Set an exception and return -1 on failure.

     If no data was set under the index, set 'extra' to ‘NULL’ and
     return 0 without setting an exception.

     Added in version 3.6: as ‘_PyCode_GetExtra’

     Cambiato nella versione 3.12: Renamed to
     ‘PyUnstable_Code_GetExtra’.  The old private name is deprecated,
     but will be available until the API changes.

 -- C Funzione: int PyUnstable_Code_SetExtra (PyObject *code, Py_ssize_t
          index, void *extra)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Set the extra data stored under the given index to 'extra'.  Return
     0 on success.  Set an exception and return -1 on failure.

     Added in version 3.6: as ‘_PyCode_SetExtra’

     Cambiato nella versione 3.12: Renamed to
     ‘PyUnstable_Code_SetExtra’.  The old private name is deprecated,
     but will be available until the API changes.


File: python.info,  Node: Other Objects,  Next: C API for extension modules,  Prev: Function Objects<2>,  Up: Concrete Objects Layer

7.9.6 Other Objects
-------------------

* Menu:

* File Objects::
* Module Objects::
* Module definitions::
* Creating extension modules dynamically::
* Support functions::
* Iterator Objects::
* Descriptor Objects::
* Slice Objects::
* MemoryView objects::
* Pickle buffer objects::
* Weak Reference Objects: Weak Reference Objects<2>.
* Capsules: Capsules<2>.
* Frame Objects::
* Generator Objects::
* Coroutine Objects: Coroutine Objects<2>.
* Context Variables Objects::
* Objects for Type Hinting::


File: python.info,  Node: File Objects,  Next: Module Objects,  Up: Other Objects

7.9.6.1 File Objects
....................

These APIs are a minimal emulation of the Python 2 C API for built-in
file objects, which used to rely on the buffered I/O (FILE*) support
from the C standard library.  In Python 3, files and streams use the new
*note io: 83. module, which defines several layers over the low-level
unbuffered I/O of the operating system.  The functions described below
are convenience C wrappers over these new APIs, and meant mostly for
internal error reporting in the interpreter; third-party code is advised
to access the *note io: 83. APIs instead.

 -- C Funzione: *note PyObject: 5df. *PyFile_FromFd (int fd, const char
          *name, const char *mode, int buffering, const char *encoding,
          const char *errors, const char *newline, int closefd)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a Python file object from the file
     descriptor of an already opened file 'fd'.  The arguments 'name',
     'encoding', 'errors' and 'newline' can be ‘NULL’ to use the
     defaults; 'buffering' can be '-1' to use the default.  'name' is
     ignored and kept for backward compatibility.  Return ‘NULL’ on
     failure.  For a more comprehensive description of the arguments,
     please refer to the *note io.open(): 741. function documentation.

          Avvertimento: Since Python streams have their own buffering
          layer, mixing them with OS-level file descriptors can produce
          various issues (such as unexpected ordering of data).

     Cambiato nella versione 3.2: Ignore 'name' attribute.

 -- C Funzione: int PyObject_AsFileDescriptor (PyObject *p)
     ' Parte del *note ABI Stabile: 776.'  Return the file descriptor
     associated with 'p' as an int.  If the object is an integer, its
     value is returned.  If not, the object’s *note fileno(): 1795.
     method is called if it exists; the method must return an integer,
     which is returned as the file descriptor value.  Sets an exception
     and returns ‘-1’ on failure.

 -- C Funzione: *note PyObject: 5df. *PyFile_GetLine (PyObject *p, int
          n)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     Equivalent to ‘p.readline([n])’, this function reads one line from
     the object 'p'.  'p' may be a file object or any object with a
     *note readline(): 1531. method.  If 'n' is ‘0’, exactly one line is
     read, regardless of the length of the line.  If 'n' is greater than
     ‘0’, no more than 'n' bytes will be read from the file; a partial
     line can be returned.  In both cases, an empty string is returned
     if the end of the file is reached immediately.  If 'n' is less than
     ‘0’, however, one line is read regardless of length, but *note
     EOFError: 14e1. is raised if the end of the file is reached
     immediately.

 -- C Funzione: int PyFile_SetOpenCodeHook (Py_OpenCodeHookFunction
          handler)

     Overrides the normal behavior of *note io.open_code(): 1a80. to
     pass its parameter through the provided handler.

     The 'handler' is a function of type:

      -- C Tipo: typedef *note PyObject: 5df.
               *(*Py_OpenCodeHookFunction)(*note PyObject: 5df.*, void*)

          Equivalent of *note PyObject: 5df. *(*)(*note PyObject: 5df.
          *path, void *userData), where 'path' is guaranteed to be *note
          PyUnicodeObject: 998.

     The 'userData' pointer is passed into the hook function.  Since
     hook functions may be called from different runtimes, this pointer
     should not refer directly to Python state.

     As this hook is intentionally used during import, avoid importing
     new modules during its execution unless they are known to be frozen
     or available in ‘sys.modules’.

     Once a hook has been set, it cannot be removed or replaced, and
     later calls to *note PyFile_SetOpenCodeHook(): 1a82. will fail.  On
     failure, the function returns -1 and sets an exception if the
     interpreter has been initialized.

     This function is safe to call before *note Py_Initialize(): 460.

     Raises an *note auditing event: 1c56. ‘setopencodehook’ with no
     arguments.

     Added in version 3.8.

 -- C Funzione: *note PyObject: 5df. *PyFile_OpenCodeObject (PyObject
          *path)

     Open 'path' with the mode ‘'rb'’.  'path' must be a Python *note
     str: 169. object.  The behavior of this function may be overridden
     by *note PyFile_SetOpenCodeHook(): 1a82. to allow for some
     preprocessing of the text.

     This is analogous to *note io.open_code(): 1a80. in Python.

     On success, this function returns a *note strong reference: 5e2. to
     a Python file object.  On failure, this function returns ‘NULL’
     with an exception set.

     Added in version 3.8.

 -- C Funzione: *note PyObject: 5df. *PyFile_OpenCode (const char *path)

     Similar to *note PyFile_OpenCodeObject(): 540f, but 'path' is a
     UTF-8 encoded const char*.

     Added in version 3.8.

 -- C Funzione: int PyFile_WriteObject (PyObject *obj, PyObject *p, int
          flags)
     ' Parte del *note ABI Stabile: 776.'

     Write object 'obj' to file object 'p'.  The only supported flag for
     'flags' is *note Py_PRINT_RAW: 525f.; if given, the *note str():
     169. of the object is written instead of the *note repr(): 1c1.
     Return ‘0’ on success or ‘-1’ on failure; the appropriate exception
     will be set.

 -- C Funzione: int PyFile_WriteString (const char *s, PyObject *p)
     ' Parte del *note ABI Stabile: 776.'  Write string 's' to file
     object 'p'.  Return ‘0’ on success or ‘-1’ on failure; the
     appropriate exception will be set.

* Menu:

* Deprecated API: Deprecated API<4>.


File: python.info,  Node: Deprecated API<4>,  Up: File Objects

7.9.6.2 Deprecated API
......................

These are *note soft deprecated: 23d. APIs that were included in
Python’s C API by mistake.  They are documented solely for completeness;
use other ‘PyFile*’ APIs instead.

 -- C Funzione: *note PyObject: 5df. *PyFile_NewStdPrinter (int fd)

     Use *note PyFile_FromFd(): 4ffc. with defaults (‘fd, NULL, "w", -1,
     NULL, NULL, NULL, 0’) instead.

 -- C Variabile: *note PyTypeObject: c9e. PyStdPrinter_Type

     Type of file-like objects used internally at Python startup when
     *note io: 83. is not yet available.  Use Python *note open(): 316.
     or *note PyFile_FromFd(): 4ffc. to create file objects instead.


File: python.info,  Node: Module Objects,  Next: Module definitions,  Prev: File Objects,  Up: Other Objects

7.9.6.3 Module Objects
......................

 -- C Variabile: *note PyTypeObject: c9e. PyModule_Type
     ' Parte del *note ABI Stabile: 776.'

     This instance of *note PyTypeObject: c9e. represents the Python
     module type.  This is exposed to Python programs as *note
     types.ModuleType: 1016.

 -- C Funzione: int PyModule_Check (PyObject *p)

     Return true if 'p' is a module object, or a subtype of a module
     object.  This function always succeeds.

 -- C Funzione: int PyModule_CheckExact (PyObject *p)

     Return true if 'p' is a module object, but not a subtype of *note
     PyModule_Type: 503b.  This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyModule_NewObject (PyObject
          *name)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'

     Return a new module object with *note module.__name__: 1593. set to
     'name'.  The module’s ‘__name__’, *note __doc__: 1bd7, *note
     __package__: 323. and *note __loader__: 33b. attributes are filled
     in (all but ‘__name__’ are set to ‘None’).  The caller is
     responsible for setting a *note __file__: 2350. attribute.

     Return ‘NULL’ with an exception set on error.

     Added in version 3.3.

     Cambiato nella versione 3.4: *note __package__: 323. and *note
     __loader__: 33b. are now set to ‘None’.

 -- C Funzione: *note PyObject: 5df. *PyModule_New (const char *name)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Similar to *note PyModule_NewObject(): 5039, but
     the name is a UTF-8 encoded string instead of a Unicode object.

 -- C Funzione: *note PyObject: 5df. *PyModule_GetDict (PyObject
          *module)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'

     Return the dictionary object that implements 'module'’s namespace;
     this object is the same as the *note __dict__: 77e. attribute of
     the module object.  If 'module' is not a module object (or a
     subtype of a module object), *note SystemError: 796. is raised and
     ‘NULL’ is returned.

     It is recommended extensions use other ‘PyModule_*’ and
     ‘PyObject_*’ functions rather than directly manipulate a module’s
     *note __dict__: 77e.

     The returned reference is borrowed from the module; it is valid
     until the module is destroyed.

 -- C Funzione: *note PyObject: 5df. *PyModule_GetNameObject (PyObject
          *module)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'

     Return 'module'’s *note __name__: 1593. value.  If the module does
     not provide one, or if it is not a string, *note SystemError: 796.
     is raised and ‘NULL’ is returned.

     Added in version 3.3.

 -- C Funzione: const char *PyModule_GetName (PyObject *module)
     ' Parte del *note ABI Stabile: 776.'  Similar to *note
     PyModule_GetNameObject(): 5037. but return the name encoded to
     ‘'utf-8'’.

     The returned buffer is only valid until the module is renamed or
     destroyed.  Note that Python code may rename a module by setting
     its *note __name__: 1593. attribute.

 -- C Funzione: void *PyModule_GetState (PyObject *module)
     ' Parte del *note ABI Stabile: 776.'  Return the «state» of the
     module, that is, a pointer to the block of memory allocated at
     module creation time, or ‘NULL’.  See *note PyModuleDef.m_size:
     b78.

 -- C Funzione: *note PyModuleDef: b76. *PyModule_GetDef (PyObject
          *module)
     ' Parte del *note ABI Stabile: 776.'  Return a pointer to the *note
     PyModuleDef: b76. struct from which the module was created, or
     ‘NULL’ if the module wasn’t created from a definition.

     On error, return ‘NULL’ with an exception set.  Use *note
     PyErr_Occurred(): 1c97. to tell this case apart from a missing
     ‘PyModuleDef’.

 -- C Funzione: *note PyObject: 5df. *PyModule_GetFilenameObject
          (PyObject *module)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

     Return the name of the file from which 'module' was loaded using
     'module'’s *note __file__: 2350. attribute.  If this is not
     defined, or if it is not a string, raise *note SystemError: 796.
     and return ‘NULL’; otherwise return a reference to a Unicode
     object.

     Added in version 3.2.

 -- C Funzione: const char *PyModule_GetFilename (PyObject *module)
     ' Parte del *note ABI Stabile: 776.'  Similar to *note
     PyModule_GetFilenameObject(): 42e. but return the filename encoded
     to “utf-8”.

     The returned buffer is only valid until the module’s *note
     __file__: 2350. attribute is reassigned or the module is destroyed.

     Deprecato dalla versione 3.2: *note PyModule_GetFilename(): 42d.
     raises *note UnicodeEncodeError: 888. on unencodable filenames, use
     *note PyModule_GetFilenameObject(): 42e. instead.


File: python.info,  Node: Module definitions,  Next: Creating extension modules dynamically,  Prev: Module Objects,  Up: Other Objects

7.9.6.4 Module definitions
..........................

The functions in the previous section work on any module object,
including modules imported from Python code.

Modules defined using the C API typically use a 'module definition',
*note PyModuleDef: b76. – a statically allocated, constant “description»
of how a module should be created.

The definition is usually used to define an extension’s “main” module
object (see *note Defining extension modules: 4ee5. for details).  It is
also used to *note create extension modules dynamically: 541c.

Unlike *note PyModule_New(): 5038, the definition allows management of
'module state' – a piece of memory that is allocated and cleared
together with the module object.  Unlike the module’s Python attributes,
Python code cannot replace or delete data stored in module state.

 -- C Tipo: type PyModuleDef
     ' Parte del *note ABI Stabile: 776. (inclusi tutti i membri).'  The
     module definition struct, which holds all information needed to
     create a module object.  This structure must be statically
     allocated (or be otherwise guaranteed to be valid while any modules
     created from it exist).  Usually, there is only one variable of
     this type for each extension module.

      -- C Membro: PyModuleDef_Base m_base

          Always initialize this member to ‘PyModuleDef_HEAD_INIT’.

      -- C Membro: const char *m_name

          Name for the new module.

      -- C Membro: const char *m_doc

          Docstring for the module; usually a docstring variable created
          with *note PyDoc_STRVAR: 1d43. is used.

      -- C Membro: *note Py_ssize_t: c57. m_size

          Module state may be kept in a per-module memory area that can
          be retrieved with *note PyModule_GetState(): b79, rather than
          in static globals.  This makes modules safe for use in
          multiple sub-interpreters.

          This memory area is allocated based on 'm_size' on module
          creation, and freed when the module object is deallocated,
          after the *note m_free: b75. function has been called, if
          present.

          Setting it to a non-negative value means that the module can
          be re-initialized and specifies the additional amount of
          memory it requires for its state.

          Setting ‘m_size’ to ‘-1’ means that the module does not
          support sub-interpreters, because it has global state.
          Negative ‘m_size’ is only allowed when using *note legacy
          single-phase initialization: 51e6. or when *note creating
          modules dynamically: 541c.

          See PEP 3121(1) for more details.

      -- C Membro: *note PyMethodDef: 16de. *m_methods

          A pointer to a table of module-level functions, described by
          *note PyMethodDef: 16de. values.  Can be ‘NULL’ if no
          functions are present.

      -- C Membro: *note PyModuleDef_Slot: 5031. *m_slots

          An array of slot definitions for multi-phase initialization,
          terminated by a ‘{0, NULL}’ entry.  When using legacy
          single-phase initialization, 'm_slots' must be ‘NULL’.

          Cambiato nella versione 3.5: Prior to version 3.5, this member
          was always set to ‘NULL’, and was defined as:

                -- C Membro: *note inquiry: 5183. m_reload

      -- C Membro: *note traverseproc: 5192. m_traverse

          A traversal function to call during GC traversal of the module
          object, or ‘NULL’ if not needed.

          This function is not called if the module state was requested
          but is not allocated yet.  This is the case immediately after
          the module is created and before the module is executed (*note
          Py_mod_exec: b77. function).  More precisely, this function is
          not called if *note m_size: b78. is greater than 0 and the
          module state (as returned by *note PyModule_GetState(): b79.)
          is ‘NULL’.

          Cambiato nella versione 3.9: No longer called before the
          module state is allocated.

      -- C Membro: *note inquiry: 5183. m_clear

          A clear function to call during GC clearing of the module
          object, or ‘NULL’ if not needed.

          This function is not called if the module state was requested
          but is not allocated yet.  This is the case immediately after
          the module is created and before the module is executed (*note
          Py_mod_exec: b77. function).  More precisely, this function is
          not called if *note m_size: b78. is greater than 0 and the
          module state (as returned by *note PyModule_GetState(): b79.)
          is ‘NULL’.

          Like *note PyTypeObject.tp_clear: 4ecb, this function is not
          'always' called before a module is deallocated.  For example,
          when reference counting is enough to determine that an object
          is no longer used, the cyclic garbage collector is not
          involved and *note m_free: b75. is called directly.

          Cambiato nella versione 3.9: No longer called before the
          module state is allocated.

      -- C Membro: *note freefunc: 5422. m_free

          A function to call during deallocation of the module object,
          or ‘NULL’ if not needed.

          This function is not called if the module state was requested
          but is not allocated yet.  This is the case immediately after
          the module is created and before the module is executed (*note
          Py_mod_exec: b77. function).  More precisely, this function is
          not called if *note m_size: b78. is greater than 0 and the
          module state (as returned by *note PyModule_GetState(): b79.)
          is ‘NULL’.

          Cambiato nella versione 3.9: No longer called before the
          module state is allocated.

* Menu:

* Module slots::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3121/


File: python.info,  Node: Module slots,  Up: Module definitions

7.9.6.5 Module slots
....................

 -- C Tipo: type PyModuleDef_Slot
     ' Parte del *note ABI Stabile: 776. (inclusi tutti i membri) dalla
     versione 3.5.'
      -- C Membro: int slot

          A slot ID, chosen from the available values explained below.

      -- C Membro: void *value

          Value of the slot, whose meaning depends on the slot ID.

     Added in version 3.5.

The available slot types are:

 -- C Macro: Py_mod_create
     ' Parte del *note ABI Stabile: 776. dalla versione 3.5.'  Specifies
     a function that is called to create the module object itself.  The
     'value' pointer of this slot must point to a function of the
     signature:

      -- C Funzione: *note PyObject: 5df. *create_module (PyObject
               *spec, PyModuleDef *def)

     The function receives a *note ModuleSpec: 2255. instance, as
     defined in PEP 451(1), and the module definition.  It should return
     a new module object, or set an error and return ‘NULL’.

     This function should be kept minimal.  In particular, it should not
     call arbitrary Python code, as trying to import the same module
     again may result in an infinite loop.

     Multiple ‘Py_mod_create’ slots may not be specified in one module
     definition.

     If ‘Py_mod_create’ is not specified, the import machinery will
     create a normal module object using *note PyModule_New(): 5038.
     The name is taken from 'spec', not the definition, to allow
     extension modules to dynamically adjust to their place in the
     module hierarchy and be imported under different names through
     symlinks, all while sharing a single module definition.

     There is no requirement for the returned object to be an instance
     of *note PyModule_Type: 503b.  Any type can be used, as long as it
     supports setting and getting import-related attributes.  However,
     only ‘PyModule_Type’ instances may be returned if the ‘PyModuleDef’
     has non-‘NULL’ ‘m_traverse’, ‘m_clear’, ‘m_free’; non-zero
     ‘m_size’; or slots other than ‘Py_mod_create’.

     Added in version 3.5.

 -- C Macro: Py_mod_exec
     ' Parte del *note ABI Stabile: 776. dalla versione 3.5.'  Specifies
     a function that is called to 'execute' the module.  This is
     equivalent to executing the code of a Python module: typically,
     this function adds classes and constants to the module.  The
     signature of the function is:

      -- C Funzione: int exec_module (PyObject *module)

     If multiple ‘Py_mod_exec’ slots are specified, they are processed
     in the order they appear in the 'm_slots' array.

     Added in version 3.5.

 -- C Macro: Py_mod_multiple_interpreters
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'
     Specifies one of the following values:

      -- C Macro: Py_MOD_MULTIPLE_INTERPRETERS_NOT_SUPPORTED

          The module does not support being imported in subinterpreters.

      -- C Macro: Py_MOD_MULTIPLE_INTERPRETERS_SUPPORTED

          The module supports being imported in subinterpreters, but
          only when they share the main interpreter’s GIL. (See *note
          Isolating Extension Modules: 166.)

      -- C Macro: Py_MOD_PER_INTERPRETER_GIL_SUPPORTED

          The module supports being imported in subinterpreters, even
          when they have their own GIL. (See *note Isolating Extension
          Modules: 166.)

     This slot determines whether or not importing this module in a
     subinterpreter will fail.

     Multiple ‘Py_mod_multiple_interpreters’ slots may not be specified
     in one module definition.

     If ‘Py_mod_multiple_interpreters’ is not specified, the import
     machinery defaults to ‘Py_MOD_MULTIPLE_INTERPRETERS_SUPPORTED’.

     Added in version 3.12.

 -- C Macro: Py_mod_gil
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'
     Specifies one of the following values:

      -- C Macro: Py_MOD_GIL_USED

          The module depends on the presence of the global interpreter
          lock (GIL), and may access global state without
          synchronization.

      -- C Macro: Py_MOD_GIL_NOT_USED

          The module is safe to run without an active GIL.

     This slot is ignored by Python builds not configured with *note
     -disable-gil: 49a.  Otherwise, it determines whether or not
     importing this module will cause the GIL to be automatically
     enabled.  See *note Free-threaded CPython: 46d. for more detail.

     Multiple ‘Py_mod_gil’ slots may not be specified in one module
     definition.

     If ‘Py_mod_gil’ is not specified, the import machinery defaults to
     ‘Py_MOD_GIL_USED’.

     Added in version 3.13.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0451/


File: python.info,  Node: Creating extension modules dynamically,  Next: Support functions,  Prev: Module definitions,  Up: Other Objects

7.9.6.6 Creating extension modules dynamically
..............................................

The following functions may be used to create a module outside of an
extension’s *note initialization function: 51e5.  They are also used in
*note single-phase initialization: 51e6.

 -- C Funzione: *note PyObject: 5df. *PyModule_Create (PyModuleDef *def)
     'Valore di ritorno: Nuovo riferimento.'  Create a new module
     object, given the definition in 'def'.  This is a macro that calls
     *note PyModule_Create2(): 5033. with 'module_api_version' set to
     *note PYTHON_API_VERSION: 4916, or to *note PYTHON_ABI_VERSION:
     542d. if using the *note limited API: 637.

 -- C Funzione: *note PyObject: 5df. *PyModule_Create2 (PyModuleDef
          *def, int module_api_version)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a new module object, given the definition in
     'def', assuming the API version 'module_api_version'.  If that
     version does not match the version of the running interpreter, a
     *note RuntimeWarning: 4d8. is emitted.

     Return ‘NULL’ with an exception set on error.

     This function does not support slots.  The *note m_slots: 51ed.
     member of 'def' must be ‘NULL’.

          Nota: Most uses of this function should be using *note
          PyModule_Create(): 51ef. instead; only use this if you are
          sure you need it.

 -- C Funzione: *note PyObject: 5df. *PyModule_FromDefAndSpec
          (PyModuleDef *def, PyObject *spec)
     'Valore di ritorno: Nuovo riferimento.'  This macro calls *note
     PyModule_FromDefAndSpec2(): 10b6. with 'module_api_version' set to
     *note PYTHON_API_VERSION: 4916, or to *note PYTHON_ABI_VERSION:
     542d. if using the *note limited API: 637.

     Added in version 3.5.

 -- C Funzione: *note PyObject: 5df. *PyModule_FromDefAndSpec2
          (PyModuleDef *def, PyObject *spec, int module_api_version)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'  Create a new module object,
     given the definition in 'def' and the ModuleSpec 'spec', assuming
     the API version 'module_api_version'.  If that version does not
     match the version of the running interpreter, a *note
     RuntimeWarning: 4d8. is emitted.

     Return ‘NULL’ with an exception set on error.

     Note that this does not process execution slots (*note Py_mod_exec:
     b77.).  Both ‘PyModule_FromDefAndSpec’ and ‘PyModule_ExecDef’ must
     be called to fully initialize a module.

          Nota: Most uses of this function should be using *note
          PyModule_FromDefAndSpec(): 10b5. instead; only use this if you
          are sure you need it.

     Added in version 3.5.

 -- C Funzione: int PyModule_ExecDef (PyObject *module, PyModuleDef
          *def)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Process
     any execution slots (*note Py_mod_exec: b77.) given in 'def'.

     Added in version 3.5.

 -- C Macro: PYTHON_API_VERSION

     The C API version.  Defined for backwards compatibility.

     Currently, this constant is not updated in new Python versions, and
     is not useful for versioning.  This may change in the future.

 -- C Macro: PYTHON_ABI_VERSION

     Defined as ‘3’ for backwards compatibility.

     Currently, this constant is not updated in new Python versions, and
     is not useful for versioning.  This may change in the future.


File: python.info,  Node: Support functions,  Next: Iterator Objects,  Prev: Creating extension modules dynamically,  Up: Other Objects

7.9.6.7 Support functions
.........................

The following functions are provided to help initialize a module state.
They are intended for a module’s execution slots (*note Py_mod_exec:
b77.), the initialization function for legacy *note single-phase
initialization: 51e6, or code that creates modules dynamically.

 -- C Funzione: int PyModule_AddObjectRef (PyObject *module, const char
          *name, PyObject *value)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Add an
     object to 'module' as 'name'.  This is a convenience function which
     can be used from the module’s initialization function.

     On success, return ‘0’.  On error, raise an exception and return
     ‘-1’.

     Example usage:

          static int
          add_spam(PyObject *module, int value)
          {
              PyObject *obj = PyLong_FromLong(value);
              if (obj == NULL) {
                  return -1;
              }
              int res = PyModule_AddObjectRef(module, "spam", obj);
              Py_DECREF(obj);
              return res;
           }

     To be convenient, the function accepts ‘NULL’ 'value' with an
     exception set.  In this case, return ‘-1’ and just leave the raised
     exception unchanged.

     The example can also be written without checking explicitly if
     'obj' is ‘NULL’:

          static int
          add_spam(PyObject *module, int value)
          {
              PyObject *obj = PyLong_FromLong(value);
              int res = PyModule_AddObjectRef(module, "spam", obj);
              Py_XDECREF(obj);
              return res;
           }

     Note that ‘Py_XDECREF()’ should be used instead of ‘Py_DECREF()’ in
     this case, since 'obj' can be ‘NULL’.

     The number of different 'name' strings passed to this function
     should be kept small, usually by only using statically allocated
     strings as 'name'.  For names that aren’t known at compile time,
     prefer calling *note PyUnicode_FromString(): 50ea. and *note
     PyObject_SetAttr(): 506f. directly.  For more details, see *note
     PyUnicode_InternFromString(): 1974, which may be used internally to
     create a key object.

     Added in version 3.10.

 -- C Funzione: int PyModule_Add (PyObject *module, const char *name,
          PyObject *value)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Similar
     to *note PyModule_AddObjectRef(): 60a, but «steals» a reference to
     'value'.  It can be called with a result of function that returns a
     new reference without bothering to check its result or even saving
     it to a variable.

     Example usage:

          if (PyModule_Add(module, "spam", PyBytes_FromString(value)) < 0) {
              goto error;
          }

     Added in version 3.13.

 -- C Funzione: int PyModule_AddObject (PyObject *module, const char
          *name, PyObject *value)
     ' Parte del *note ABI Stabile: 776.'  Similar to *note
     PyModule_AddObjectRef(): 60a, but steals a reference to 'value' on
     success (if it returns ‘0’).

     The new *note PyModule_Add(): 609. or *note
     PyModule_AddObjectRef(): 60a. functions are recommended, since it
     is easy to introduce reference leaks by misusing the *note
     PyModule_AddObject(): 60b. function.

          Nota: Unlike other functions that steal references,
          ‘PyModule_AddObject()’ only releases the reference to 'value'
          'on success'.

          This means that its return value must be checked, and calling
          code must *note Py_XDECREF(): 993. 'value' manually on error.

     Example usage:

          PyObject *obj = PyBytes_FromString(value);
          if (PyModule_AddObject(module, "spam", obj) < 0) {
              // If 'obj' is not NULL and PyModule_AddObject() failed,
              // 'obj' strong reference must be deleted with Py_XDECREF().
              // If 'obj' is NULL, Py_XDECREF() does nothing.
              Py_XDECREF(obj);
              goto error;
          }
          // PyModule_AddObject() stole a reference to obj:
          // Py_XDECREF(obj) is not needed here.

     Deprecato dalla versione 3.13: *note PyModule_AddObject(): 60b. is
     *note soft deprecated: 23d.

 -- C Funzione: int PyModule_AddIntConstant (PyObject *module, const
          char *name, long value)
     ' Parte del *note ABI Stabile: 776.'  Add an integer constant to
     'module' as 'name'.  This convenience function can be used from the
     module’s initialization function.  Return ‘-1’ with an exception
     set on error, ‘0’ on success.

     This is a convenience function that calls *note PyLong_FromLong():
     1bb8. and *note PyModule_AddObjectRef(): 60a.; see their
     documentation for details.

 -- C Funzione: int PyModule_AddStringConstant (PyObject *module, const
          char *name, const char *value)
     ' Parte del *note ABI Stabile: 776.'  Add a string constant to
     'module' as 'name'.  This convenience function can be used from the
     module’s initialization function.  The string 'value' must be
     ‘NULL’-terminated.  Return ‘-1’ with an exception set on error, ‘0’
     on success.

     This is a convenience function that calls *note
     PyUnicode_InternFromString(): 1974. and *note
     PyModule_AddObjectRef(): 60a.; see their documentation for details.

 -- C Macro: PyModule_AddIntMacro (module, macro)

     Add an int constant to 'module'.  The name and the value are taken
     from 'macro'.  For example ‘PyModule_AddIntMacro(module, AF_INET)’
     adds the int constant 'AF_INET' with the value of 'AF_INET' to
     'module'.  Return ‘-1’ with an exception set on error, ‘0’ on
     success.

 -- C Macro: PyModule_AddStringMacro (module, macro)

     Add a string constant to 'module'.

 -- C Funzione: int PyModule_AddType (PyObject *module, PyTypeObject
          *type)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Add a
     type object to 'module'.  The type object is finalized by calling
     internally *note PyType_Ready(): 981.  The name of the type object
     is taken from the last component of *note tp_name: 1c98. after dot.
     Return ‘-1’ with an exception set on error, ‘0’ on success.

     Added in version 3.9.

 -- C Funzione: int PyModule_AddFunctions (PyObject *module, PyMethodDef
          *functions)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Add the
     functions from the ‘NULL’ terminated 'functions' array to 'module'.
     Refer to the *note PyMethodDef: 16de. documentation for details on
     individual entries (due to the lack of a shared module namespace,
     module level «functions» implemented in C typically receive the
     module as their first parameter, making them similar to instance
     methods on Python classes).

     This function is called automatically when creating a module from
     ‘PyModuleDef’ (such as when using *note Multi-phase initialization:
     51eb, ‘PyModule_Create’, or ‘PyModule_FromDefAndSpec’).  Some
     module authors may prefer defining functions in multiple *note
     PyMethodDef: 16de. arrays; in that case they should call this
     function directly.

     The 'functions' array must be statically allocated (or otherwise
     guaranteed to outlive the module object).

     Added in version 3.5.

 -- C Funzione: int PyModule_SetDocString (PyObject *module, const char
          *docstring)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Set the
     docstring for 'module' to 'docstring'.  This function is called
     automatically when creating a module from ‘PyModuleDef’ (such as
     when using *note Multi-phase initialization: 51eb,
     ‘PyModule_Create’, or ‘PyModule_FromDefAndSpec’).

     Return ‘0’ on success.  Return ‘-1’ with an exception set on error.

     Added in version 3.5.

 -- C Funzione: int PyUnstable_Module_SetGIL (PyObject *module, void
          *gil)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Indicate that 'module' does or does not support running without the
     global interpreter lock (GIL), using one of the values from *note
     Py_mod_gil: 483.  It must be called during 'module'’s
     initialization function when using *note Legacy single-phase
     initialization: 51e6.  If this function is not called during module
     initialization, the import machinery assumes the module does not
     support running without the GIL. This function is only available in
     Python builds configured with *note -disable-gil: 49a.  Return ‘-1’
     with an exception set on error, ‘0’ on success.

     Added in version 3.13.

* Menu:

* Module lookup (single-phase initialization): Module lookup single-phase initialization.


File: python.info,  Node: Module lookup single-phase initialization,  Up: Support functions

7.9.6.8 Module lookup (single-phase initialization)
...................................................

The legacy *note single-phase initialization: 51e6. initialization
scheme creates singleton modules that can be looked up in the context of
the current interpreter.  This allows the module object to be retrieved
later with only a reference to the module definition.

These functions will not work on modules created using multi-phase
initialization, since multiple such modules can be created from a single
definition.

 -- C Funzione: *note PyObject: 5df. *PyState_FindModule (PyModuleDef
          *def)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Returns the module object that was
     created from 'def' for the current interpreter.  This method
     requires that the module object has been attached to the
     interpreter state with *note PyState_AddModule(): 508c. beforehand.
     In case the corresponding module object is not found or has not
     been attached to the interpreter state yet, it returns ‘NULL’.

 -- C Funzione: int PyState_AddModule (PyObject *module, PyModuleDef
          *def)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.3.'  Attaches
     the module object passed to the function to the interpreter state.
     This allows the module object to be accessible via *note
     PyState_FindModule(): 508d.

     Only effective on modules created using single-phase
     initialization.

     Python calls ‘PyState_AddModule’ automatically after importing a
     module that uses *note single-phase initialization: 51e6, so it is
     unnecessary (but harmless) to call it from module initialization
     code.  An explicit call is needed only if the module’s own init
     code subsequently calls ‘PyState_FindModule’.  The function is
     mainly intended for implementing alternative import mechanisms
     (either by calling it directly, or by referring to its
     implementation for details of the required state updates).

     If a module was attached previously using the same 'def', it is
     replaced by the new 'module'.

     The caller must have an *note attached thread state: 4eba.

     Return ‘-1’ with an exception set on error, ‘0’ on success.

     Added in version 3.3.

 -- C Funzione: int PyState_RemoveModule (PyModuleDef *def)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.3.'  Removes
     the module object created from 'def' from the interpreter state.
     Return ‘-1’ with an exception set on error, ‘0’ on success.

     The caller must have an *note attached thread state: 4eba.

     Added in version 3.3.


File: python.info,  Node: Iterator Objects,  Next: Descriptor Objects,  Prev: Support functions,  Up: Other Objects

7.9.6.9 Iterator Objects
........................

Python provides two general-purpose iterator objects.  The first, a
sequence iterator, works with an arbitrary sequence supporting the *note
__getitem__(): 588. method.  The second works with a callable object and
a sentinel value, calling the callable for each item in the sequence,
and ending the iteration when the sentinel value is returned.

 -- C Variabile: *note PyTypeObject: c9e. PySeqIter_Type
     ' Parte del *note ABI Stabile: 776.'  Type object for iterator
     objects returned by *note PySeqIter_New(): 5076. and the
     one-argument form of the *note iter(): 9d9. built-in function for
     built-in sequence types.

 -- C Funzione: int PySeqIter_Check (PyObject *op)

     Return true if the type of 'op' is *note PySeqIter_Type: 5077.
     This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PySeqIter_New (PyObject *seq)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return an iterator that works with a general
     sequence object, 'seq'.  The iteration ends when the sequence
     raises *note IndexError: 173c. for the subscripting operation.

 -- C Variabile: *note PyTypeObject: c9e. PyCallIter_Type
     ' Parte del *note ABI Stabile: 776.'  Type object for iterator
     objects returned by *note PyCallIter_New(): 4f68. and the
     two-argument form of the *note iter(): 9d9. built-in function.

 -- C Funzione: int PyCallIter_Check (PyObject *op)

     Return true if the type of 'op' is *note PyCallIter_Type: 4f69.
     This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyCallIter_New (PyObject
          *callable, PyObject *sentinel)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new iterator.  The first parameter,
     'callable', can be any Python callable object that can be called
     with no parameters; each call to it should return the next item in
     the iteration.  When 'callable' returns a value equal to
     'sentinel', the iteration will be terminated.

* Menu:

* Range Objects::
* Builtin Iterator Types::
* Other Iterator Objects::


File: python.info,  Node: Range Objects,  Next: Builtin Iterator Types,  Up: Iterator Objects

7.9.6.10 Range Objects
......................

 -- C Variabile: *note PyTypeObject: c9e. PyRange_Type
     ' Parte del *note ABI Stabile: 776.'  The type object for *note
     range: b3f. objects.

 -- C Funzione: int PyRange_Check (PyObject *o)

     Return true if the object 'o' is an instance of a *note range: b3f.
     object.  This function always succeeds.


File: python.info,  Node: Builtin Iterator Types,  Next: Other Iterator Objects,  Prev: Range Objects,  Up: Iterator Objects

7.9.6.11 Builtin Iterator Types
...............................

These are built-in iteration types that are included in Python’s C API,
but provide no additional functions.  They are here for completeness.

C type                                                 Python type
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
 -- C Variabile: *note PyTypeObject: c9e.              *note enumerate: 1688.
          PyEnum_Type                                  
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e.              *note filter: a66.
          PyFilter_Type                                
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyMap_Type   *note map: 19f.
     ' Parte del *note ABI Stabile: 776.'              

 -- C Variabile: *note PyTypeObject: c9e.              *note reversed: a67.
          PyReversed_Type                              
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyZip_Type   *note zip: 1a0.
     ' Parte del *note ABI Stabile: 776.'              


File: python.info,  Node: Other Iterator Objects,  Prev: Builtin Iterator Types,  Up: Iterator Objects

7.9.6.12 Other Iterator Objects
...............................

 -- C Variabile: *note PyTypeObject: c9e. PyByteArrayIter_Type
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyBytesIter_Type
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyListIter_Type
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyListRevIter_Type
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PySetIter_Type
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyTupleIter_Type
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyRangeIter_Type
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyLongRangeIter_Type
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyDictIterKey_Type
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyDictRevIterKey_Type
     ' Parte del *note ABI Stabile: 776. dalla versione 3.8.'

 -- C Variabile: *note PyTypeObject: c9e. PyDictIterValue_Type
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyDictRevIterValue_Type
     ' Parte del *note ABI Stabile: 776. dalla versione 3.8.'

 -- C Variabile: *note PyTypeObject: c9e. PyDictIterItem_Type
     ' Parte del *note ABI Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyDictRevIterItem_Type
     ' Parte del *note ABI Stabile: 776. dalla versione 3.8.'

 -- C Variabile: *note PyTypeObject: c9e. PyODictIter_Type

     Type objects for iterators of various built-in objects.

     Do not create instances of these directly; prefer calling *note
     PyObject_GetIter(): 506a. instead.

     Note that there is no guarantee that a given built-in type uses a
     given iterator type.  For example, iterating over *note range: b3f.
     will use one of two iterator types depending on the size of the
     range.  Other types may start using a similar scheme in the future,
     without warning.


File: python.info,  Node: Descriptor Objects,  Next: Slice Objects,  Prev: Iterator Objects,  Up: Other Objects

7.9.6.13 Descriptor Objects
...........................

«Descriptors» are objects that describe some attribute of an object.
They are found in the dictionary of type objects.

 -- C Variabile: *note PyTypeObject: c9e. PyProperty_Type
     ' Parte del *note ABI Stabile: 776.'  The type object for the
     built-in descriptor types.

 -- C Funzione: *note PyObject: 5df. *PyDescr_NewGetSet (PyTypeObject
          *type, struct PyGetSetDef *getset)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

 -- C Funzione: *note PyObject: 5df. *PyDescr_NewMember (PyTypeObject
          *type, struct PyMemberDef *meth)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyMemberDescr_Type
     ' Parte del *note ABI Stabile: 776.'  The type object for member
     descriptor objects created from *note PyMemberDef: 772. structures.
     These descriptors expose fields of a C struct as attributes on a
     type, and correspond to *note types.MemberDescriptorType: 29d0.
     objects in Python.

 -- C Variabile: *note PyTypeObject: c9e. PyGetSetDescr_Type
     ' Parte del *note ABI Stabile: 776.'  The type object for get/set
     descriptor objects created from *note PyGetSetDef: db4. structures.
     These descriptors implement attributes whose value is computed by C
     getter and setter functions, and are used for many built-in type
     attributes.

 -- C Funzione: *note PyObject: 5df. *PyDescr_NewMethod (PyTypeObject
          *type, struct PyMethodDef *meth)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

 -- C Variabile: *note PyTypeObject: c9e. PyMethodDescr_Type
     ' Parte del *note ABI Stabile: 776.'  The type object for method
     descriptor objects created from *note PyMethodDef: 16de.
     structures.  These descriptors expose C functions as methods on a
     type, and correspond to *note types.MemberDescriptorType: 29d0.
     objects in Python.

 -- C Funzione: *note PyObject: 5df. *PyDescr_NewWrapper (PyTypeObject
          *type, struct wrapperbase *wrapper, void *wrapped)
     'Valore di ritorno: Nuovo riferimento.'

 -- C Variabile: *note PyTypeObject: c9e. PyWrapperDescr_Type
     ' Parte del *note ABI Stabile: 776.'  The type object for wrapper
     descriptor objects created by *note PyDescr_NewWrapper(): 543f. and
     *note PyWrapper_New(): 50f7.  Wrapper descriptors are used
     internally to expose special methods implemented via wrapper
     structures, and appear in Python as *note
     types.WrapperDescriptorType: d94. objects.

 -- C Funzione: *note PyObject: 5df. *PyDescr_NewClassMethod
          (PyTypeObject *type, PyMethodDef *method)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

 -- C Funzione: int PyDescr_IsData (PyObject *descr)

     Return non-zero if the descriptor object 'descr' describes a data
     attribute, or ‘0’ if it describes a method.  'descr' must be a
     descriptor object; there is no error checking.

 -- C Funzione: *note PyObject: 5df. *PyWrapper_New (PyObject*,
          PyObject*)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'

* Menu:

* Built-in descriptors::


File: python.info,  Node: Built-in descriptors,  Up: Descriptor Objects

7.9.6.14 Built-in descriptors
.............................

 -- C Variabile: *note PyTypeObject: c9e. PySuper_Type
     ' Parte del *note ABI Stabile: 776.'  The type object for super
     objects.  This is the same object as *note super: 1a6. in the
     Python layer.

 -- C Variabile: *note PyTypeObject: c9e. PyClassMethod_Type

     The type of class method objects.  This is the same object as *note
     classmethod: 48f. in the Python layer.

 -- C Variabile: *note PyTypeObject: c9e. PyClassMethodDescr_Type
     ' Parte del *note ABI Stabile: 776.'  The type object for C-level
     class method descriptor objects.  This is the type of the
     descriptors created for *note classmethod(): 48f. defined in C
     extension types, and is the same object as *note classmethod: 48f.
     in Python.

 -- C Funzione: *note PyObject: 5df. *PyClassMethod_New (PyObject
          *callable)

     Create a new *note classmethod: 48f. object wrapping 'callable'.
     'callable' must be a callable object and must not be ‘NULL’.

     On success, this function returns a *note strong reference: 5e2. to
     a new class method descriptor.  On failure, this function returns
     ‘NULL’ with an exception set.

 -- C Variabile: *note PyTypeObject: c9e. PyStaticMethod_Type

     The type of static method objects.  This is the same object as
     *note staticmethod: 453. in the Python layer.

 -- C Funzione: *note PyObject: 5df. *PyStaticMethod_New (PyObject
          *callable)

     Create a new *note staticmethod: 453. object wrapping 'callable'.
     'callable' must be a callable object and must not be ‘NULL’.

     On success, this function returns a *note strong reference: 5e2. to
     a new static method descriptor.  On failure, this function returns
     ‘NULL’ with an exception set.


File: python.info,  Node: Slice Objects,  Next: MemoryView objects,  Prev: Descriptor Objects,  Up: Other Objects

7.9.6.15 Slice Objects
......................

 -- C Variabile: *note PyTypeObject: c9e. PySlice_Type
     ' Parte del *note ABI Stabile: 776.'  The type object for slice
     objects.  This is the same as *note slice: 695. in the Python
     layer.

 -- C Funzione: int PySlice_Check (PyObject *ob)

     Return true if 'ob' is a slice object; 'ob' must not be ‘NULL’.
     This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PySlice_New (PyObject *start,
          PyObject *stop, PyObject *step)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a new slice object with the given values.
     The 'start', 'stop', and 'step' parameters are used as the values
     of the slice object attributes of the same names.  Any of the
     values may be ‘NULL’, in which case the ‘None’ will be used for the
     corresponding attribute.

     Return ‘NULL’ with an exception set if the new object could not be
     allocated.

 -- C Funzione: int PySlice_GetIndices (PyObject *slice, Py_ssize_t
          length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step)
     ' Parte del *note ABI Stabile: 776.'  Retrieve the start, stop and
     step indices from the slice object 'slice', assuming a sequence of
     length 'length'.  Treats indices greater than 'length' as errors.

     Returns ‘0’ on success and ‘-1’ on error with no exception set
     (unless one of the indices was not ‘None’ and failed to be
     converted to an integer, in which case ‘-1’ is returned with an
     exception set).

     You probably do not want to use this function.

     Cambiato nella versione 3.2: The parameter type for the 'slice'
     parameter was ‘PySliceObject*’ before.

 -- C Funzione: int PySlice_GetIndicesEx (PyObject *slice, Py_ssize_t
          length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step,
          Py_ssize_t *slicelength)
     ' Parte del *note ABI Stabile: 776.'  Usable replacement for *note
     PySlice_GetIndices(): 5089.  Retrieve the start, stop, and step
     indices from the slice object 'slice' assuming a sequence of length
     'length', and store the length of the slice in 'slicelength'.  Out
     of bounds indices are clipped in a manner consistent with the
     handling of normal slices.

     Return ‘0’ on success and ‘-1’ on error with an exception set.

          Nota: This function is considered not safe for resizable
          sequences.  Its invocation should be replaced by a combination
          of *note PySlice_Unpack(): 432. and *note
          PySlice_AdjustIndices(): 433. where

               if (PySlice_GetIndicesEx(slice, length, &start, &stop, &step, &slicelength) < 0) {
                   // return error
               }

          is replaced by

               if (PySlice_Unpack(slice, &start, &stop, &step) < 0) {
                   // return error
               }
               slicelength = PySlice_AdjustIndices(length, &start, &stop, step);

     Cambiato nella versione 3.2: The parameter type for the 'slice'
     parameter was ‘PySliceObject*’ before.

     Cambiato nella versione 3.6.1: If ‘Py_LIMITED_API’ is not set or
     set to the value between ‘0x03050400’ and ‘0x03060000’ (not
     including) or ‘0x03060100’ or higher ‘PySlice_GetIndicesEx()’ is
     implemented as a macro using ‘PySlice_Unpack()’ and
     ‘PySlice_AdjustIndices()’.  Arguments 'start', 'stop' and 'step'
     are evaluated more than once.

     Deprecato dalla versione 3.6.1: If ‘Py_LIMITED_API’ is set to the
     value less than ‘0x03050400’ or between ‘0x03060000’ and
     ‘0x03060100’ (not including) ‘PySlice_GetIndicesEx()’ is a
     deprecated function.

 -- C Funzione: int PySlice_Unpack (PyObject *slice, Py_ssize_t *start,
          Py_ssize_t *stop, Py_ssize_t *step)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Extract
     the start, stop and step data members from a slice object as C
     integers.  Silently reduce values larger than ‘PY_SSIZE_T_MAX’ to
     ‘PY_SSIZE_T_MAX’, silently boost the start and stop values less
     than ‘PY_SSIZE_T_MIN’ to ‘PY_SSIZE_T_MIN’, and silently boost the
     step values less than ‘-PY_SSIZE_T_MAX’ to ‘-PY_SSIZE_T_MAX’.

     Return ‘-1’ with an exception set on error, ‘0’ on success.

     Added in version 3.6.1.

 -- C Funzione: *note Py_ssize_t: c57. PySlice_AdjustIndices (Py_ssize_t
          length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t step)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Adjust
     start/end slice indices assuming a sequence of the specified
     length.  Out of bounds indices are clipped in a manner consistent
     with the handling of normal slices.

     Return the length of the slice.  Always successful.  Doesn’t call
     Python code.

     Added in version 3.6.1.

* Menu:

* Ellipsis Object::


File: python.info,  Node: Ellipsis Object,  Up: Slice Objects

7.9.6.16 Ellipsis Object
........................

 -- C Variabile: *note PyTypeObject: c9e. PyEllipsis_Type
     ' Parte del *note ABI Stabile: 776.'  The type of Python *note
     Ellipsis: 2311. object.  Same as *note types.EllipsisType: a53. in
     the Python layer.

 -- C Variabile: *note PyObject: 5df. *Py_Ellipsis

     The Python ‘Ellipsis’ object.  This object has no methods.  Like
     *note Py_None: 4e88, it is an *note immortal: 290. singleton
     object.

     Cambiato nella versione 3.12: *note Py_Ellipsis: 544b. is immortal.


File: python.info,  Node: MemoryView objects,  Next: Pickle buffer objects,  Prev: Slice Objects,  Up: Other Objects

7.9.6.17 MemoryView objects
...........................

A *note memoryview: 165. object exposes the C level *note buffer
interface: 260. as a Python object which can then be passed around like
any other object.

 -- C Variabile: *note PyTypeObject: c9e. PyMemoryView_Type
     ' Parte del *note ABI Stabile: 776.'  This instance of *note
     PyTypeObject: c9e. represents the Python memoryview type.  This is
     the same object as *note memoryview: 165. in the Python layer.

 -- C Funzione: *note PyObject: 5df. *PyMemoryView_FromObject (PyObject
          *obj)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a memoryview object from an object that
     provides the buffer interface.  If 'obj' supports writable buffer
     exports, the memoryview object will be read/write, otherwise it may
     be either read-only or read/write at the discretion of the
     exporter.

 -- C Macro: PyBUF_READ
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Flag to
     request a readonly buffer.

 -- C Macro: PyBUF_WRITE
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  Flag to
     request a writable buffer.

 -- C Funzione: *note PyObject: 5df. *PyMemoryView_FromMemory (char
          *mem, Py_ssize_t size, int flags)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.7.'  Create a memoryview object
     using 'mem' as the underlying buffer.  'flags' can be one of *note
     PyBUF_READ: 19f3. or *note PyBUF_WRITE: 19f4.

     Added in version 3.3.

 -- C Funzione: *note PyObject: 5df. *PyMemoryView_FromBuffer (const
          Py_buffer *view)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.11.'  Create a memoryview object
     wrapping the given buffer structure 'view'.  For simple byte
     buffers, *note PyMemoryView_FromMemory(): 1378. is the preferred
     function.

 -- C Funzione: *note PyObject: 5df. *PyMemoryView_GetContiguous
          (PyObject *obj, int buffertype, char order)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a memoryview object to a *note contiguous:
     2669. chunk of memory (in either “C” or “F’ortran 'order') from an
     object that defines the buffer interface.  If memory is contiguous,
     the memoryview object points to the original memory.  Otherwise, a
     copy is made and the memoryview points to a new bytes object.

     'buffertype' can be one of *note PyBUF_READ: 19f3. or *note
     PyBUF_WRITE: 19f4.

 -- C Funzione: int PyMemoryView_Check (PyObject *obj)

     Return true if the object 'obj' is a memoryview object.  It is not
     currently allowed to create subclasses of *note memoryview: 165.
     This function always succeeds.

 -- C Funzione: *note Py_buffer: 95d. *PyMemoryView_GET_BUFFER (PyObject
          *mview)

     Return a pointer to the memoryview’s private copy of the exporter’s
     buffer.  'mview' 'must' be a memoryview instance; this macro
     doesn’t check its type, you must do it yourself or you will risk
     crashes.

 -- C Funzione: *note PyObject: 5df. *PyMemoryView_GET_BASE (PyObject
          *mview)

     Return either a pointer to the exporting object that the memoryview
     is based on or ‘NULL’ if the memoryview has been created by one of
     the functions *note PyMemoryView_FromMemory(): 1378. or *note
     PyMemoryView_FromBuffer(): 966.  'mview' 'must' be a memoryview
     instance.


File: python.info,  Node: Pickle buffer objects,  Next: Weak Reference Objects<2>,  Prev: MemoryView objects,  Up: Other Objects

7.9.6.18 Pickle buffer objects
..............................

Added in version 3.8.

A *note pickle.PickleBuffer: 1762. object wraps a *note buffer-providing
object: 260. for out-of-band data transfer with the *note pickle: ab.
module.

 -- C Variabile: *note PyTypeObject: c9e. PyPickleBuffer_Type

     This instance of *note PyTypeObject: c9e. represents the Python
     pickle buffer type.  This is the same object as *note
     pickle.PickleBuffer: 1762. in the Python layer.

 -- C Funzione: int PyPickleBuffer_Check (PyObject *op)

     Return true if 'op' is a pickle buffer instance.  This function
     always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyPickleBuffer_FromObject
          (PyObject *obj)

     Create a pickle buffer from the object 'obj'.

     This function will fail if 'obj' doesn’t support the *note buffer
     protocol: 260.

     On success, return a new pickle buffer instance.  On failure, set
     an exception and return ‘NULL’.

     Analogous to calling *note pickle.PickleBuffer: 1762. with 'obj' in
     Python.

 -- C Funzione: const *note Py_buffer: 95d. *PyPickleBuffer_GetBuffer
          (PyObject *picklebuf)

     Get a pointer to the underlying *note Py_buffer: 95d. that the
     pickle buffer wraps.

     The returned pointer is valid as long as 'picklebuf' is alive and
     has not been released.  The caller must not modify or free the
     returned *note Py_buffer: 95d.  If the pickle buffer has been
     released, raise *note ValueError: 2ec.

     On success, return a pointer to the buffer view.  On failure, set
     an exception and return ‘NULL’.

 -- C Funzione: int PyPickleBuffer_Release (PyObject *picklebuf)

     Release the underlying buffer held by the pickle buffer.

     Return ‘0’ on success.  On failure, set an exception and return
     ‘-1’.

     Analogous to calling *note pickle.PickleBuffer.release(): 2d02. in
     Python.


File: python.info,  Node: Weak Reference Objects<2>,  Next: Capsules<2>,  Prev: Pickle buffer objects,  Up: Other Objects

7.9.6.19 Weak Reference Objects
...............................

Python supports 'weak references' as first-class objects.  There are two
specific object types which directly implement weak references.  The
first is a simple reference object, and the second acts as a proxy for
the original object as much as it can.

 -- C Funzione: int PyWeakref_Check (PyObject *ob)

     Return non-zero if 'ob' is either a reference or proxy object.
     This function always succeeds.

 -- C Funzione: int PyWeakref_CheckRef (PyObject *ob)

     Return non-zero if 'ob' is a reference object or a subclass of the
     reference type.  This function always succeeds.

 -- C Funzione: int PyWeakref_CheckRefExact (PyObject *ob)

     Return non-zero if 'ob' is a reference object, but not a subclass
     of the reference type.  This function always succeeds.

 -- C Funzione: int PyWeakref_CheckProxy (PyObject *ob)

     Return non-zero if 'ob' is a proxy object.  This function always
     succeeds.

 -- C Funzione: *note PyObject: 5df. *PyWeakref_NewRef (PyObject *ob,
          PyObject *callback)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a weak reference object for the object 'ob'.
     This will always return a new reference, but is not guaranteed to
     create a new object; an existing reference object may be returned.
     The second parameter, 'callback', can be a callable object that
     receives notification when 'ob' is garbage collected; it should
     accept a single parameter, which will be the weak reference object
     itself.  'callback' may also be ‘None’ or ‘NULL’.  If 'ob' is not a
     weakly referenceable object, or if 'callback' is not callable,
     ‘None’, or ‘NULL’, this will return ‘NULL’ and raise *note
     TypeError: 198.

     Vedi anche
     ..........

     *note PyType_SUPPORTS_WEAKREFS(): 52bd. for checking if 'ob' is
     weakly referenceable.

 -- C Funzione: *note PyObject: 5df. *PyWeakref_NewProxy (PyObject *ob,
          PyObject *callback)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Return a weak reference proxy object for the object
     'ob'.  This will always return a new reference, but is not
     guaranteed to create a new object; an existing proxy object may be
     returned.  The second parameter, 'callback', can be a callable
     object that receives notification when 'ob' is garbage collected;
     it should accept a single parameter, which will be the weak
     reference object itself.  'callback' may also be ‘None’ or ‘NULL’.
     If 'ob' is not a weakly referenceable object, or if 'callback' is
     not callable, ‘None’, or ‘NULL’, this will return ‘NULL’ and raise
     *note TypeError: 198.

     Vedi anche
     ..........

     *note PyType_SUPPORTS_WEAKREFS(): 52bd. for checking if 'ob' is
     weakly referenceable.

 -- C Funzione: int PyWeakref_GetRef (PyObject *ref, PyObject **pobj)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Get a
     *note strong reference: 5e2. to the referenced object from a weak
     reference, 'ref', into '*pobj'.

        * On success, set '*pobj' to a new *note strong reference: 5e2.
          to the referenced object and return 1.

        * If the reference is dead, set '*pobj' to ‘NULL’ and return 0.

        * On error, raise an exception and return -1.

     Added in version 3.13.

 -- C Funzione: *note PyObject: 5df. *PyWeakref_GetObject (PyObject
          *ref)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Return a *note borrowed reference: 3d7.
     to the referenced object from a weak reference, 'ref'.  If the
     referent is no longer live, returns ‘Py_None’.

          Nota: This function returns a *note borrowed reference: 3d7.
          to the referenced object.  This means that you should always
          call *note Py_INCREF(): 790. on the object except when it
          cannot be destroyed before the last usage of the borrowed
          reference.

     Deprecated since version 3.13, will be removed in version 3.15: Use
     *note PyWeakref_GetRef(): 3df. instead.

 -- C Funzione: *note PyObject: 5df. *PyWeakref_GET_OBJECT (PyObject
          *ref)
     'Valore di ritorno: Riferimento preso in prestito.'  Similar to
     *note PyWeakref_GetObject(): 3dd, but does no error checking.

     Deprecated since version 3.13, will be removed in version 3.15: Use
     *note PyWeakref_GetRef(): 3df. instead.

 -- C Funzione: int PyWeakref_IsDead (PyObject *ref)

     Test if the weak reference 'ref' is dead.  Returns 1 if the
     reference is dead, 0 if it is alive, and -1 with an error set if
     'ref' is not a weak reference object.

     Added in version 3.14.

 -- C Funzione: void PyObject_ClearWeakRefs (PyObject *object)
     ' Parte del *note ABI Stabile: 776.'  This function is called by
     the *note tp_dealloc: 4ea5. handler to clear weak references.

     This iterates through the weak references for 'object' and calls
     callbacks for those references which have one.  It returns when all
     callbacks have been attempted.

 -- C Funzione: void PyUnstable_Object_ClearWeakRefsNoCallbacks
          (PyObject *object)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Clears the weakrefs for 'object' without calling the callbacks.

     This function is called by the *note tp_dealloc: 4ea5. handler for
     types with finalizers (i.e., *note __del__(): 11ff.).  The handler
     for those objects first calls *note PyObject_ClearWeakRefs(): 797.
     to clear weakrefs and call their callbacks, then the finalizer, and
     finally this function to clear any weakrefs that may have been
     created by the finalizer.

     In most circumstances, it’s more appropriate to use *note
     PyObject_ClearWeakRefs(): 797. to clear weakrefs instead of this
     function.

     Added in version 3.13.


File: python.info,  Node: Capsules<2>,  Next: Frame Objects,  Prev: Weak Reference Objects<2>,  Up: Other Objects

7.9.6.20 Capsules
.................

Refer to *note Providing a C API for an Extension Module: 1565. for more
information on using these objects.

Added in version 3.1.

 -- C Tipo: type PyCapsule

     This subtype of *note PyObject: 5df. represents an opaque value,
     useful for C extension modules which need to pass an opaque value
     (as a void* pointer) through Python code to other C code.  It is
     often used to make a C function pointer defined in one module
     available to other modules, so the regular import mechanism can be
     used to access C APIs defined in dynamically loaded modules.

 -- C Variabile: *note PyTypeObject: c9e. PyCapsule_Type
     ' Parte del *note ABI Stabile: 776.'  The type object corresponding
     to capsule objects.  This is the same object as *note
     types.CapsuleType: 29d6. in the Python layer.

 -- C Tipo: type PyCapsule_Destructor
     ' Parte del *note ABI Stabile: 776.'  The type of a destructor
     callback for a capsule.  Defined as:

          typedef void (*PyCapsule_Destructor)(PyObject *);

     See *note PyCapsule_New(): 4eac. for the semantics of
     PyCapsule_Destructor callbacks.

 -- C Funzione: int PyCapsule_CheckExact (PyObject *p)

     Return true if its argument is a *note PyCapsule: 147a.  This
     function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyCapsule_New (void *pointer,
          const char *name, PyCapsule_Destructor destructor)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Create a *note PyCapsule: 147a. encapsulating the
     'pointer'.  The 'pointer' argument may not be ‘NULL’.

     On failure, set an exception and return ‘NULL’.

     The 'name' string may either be ‘NULL’ or a pointer to a valid C
     string.  If non-‘NULL’, this string must outlive the capsule.
     (Though it is permitted to free it inside the 'destructor'.)

     If the 'destructor' argument is not ‘NULL’, it will be called with
     the capsule as its argument when it is destroyed.

     If this capsule will be stored as an attribute of a module, the
     'name' should be specified as ‘modulename.attributename’.  This
     will enable other modules to import the capsule using *note
     PyCapsule_Import(): 1bf8.

 -- C Funzione: void *PyCapsule_GetPointer (PyObject *capsule, const
          char *name)
     ' Parte del *note ABI Stabile: 776.'  Retrieve the 'pointer' stored
     in the capsule.  On failure, set an exception and return ‘NULL’.

     The 'name' parameter must compare exactly to the name stored in the
     capsule.  If the name stored in the capsule is ‘NULL’, the 'name'
     passed in must also be ‘NULL’.  Python uses the C function
     ‘strcmp()’ to compare capsule names.

 -- C Funzione: *note PyCapsule_Destructor: 4f6b.
          PyCapsule_GetDestructor (PyObject *capsule)
     ' Parte del *note ABI Stabile: 776.'  Return the current destructor
     stored in the capsule.  On failure, set an exception and return
     ‘NULL’.

     It is legal for a capsule to have a ‘NULL’ destructor.  This makes
     a ‘NULL’ return code somewhat ambiguous; use *note
     PyCapsule_IsValid(): 1564. or *note PyErr_Occurred(): 1c97. to
     disambiguate.

 -- C Funzione: void *PyCapsule_GetContext (PyObject *capsule)
     ' Parte del *note ABI Stabile: 776.'  Return the current context
     stored in the capsule.  On failure, set an exception and return
     ‘NULL’.

     It is legal for a capsule to have a ‘NULL’ context.  This makes a
     ‘NULL’ return code somewhat ambiguous; use *note
     PyCapsule_IsValid(): 1564. or *note PyErr_Occurred(): 1c97. to
     disambiguate.

 -- C Funzione: const char *PyCapsule_GetName (PyObject *capsule)
     ' Parte del *note ABI Stabile: 776.'  Return the current name
     stored in the capsule.  On failure, set an exception and return
     ‘NULL’.

     It is legal for a capsule to have a ‘NULL’ name.  This makes a
     ‘NULL’ return code somewhat ambiguous; use *note
     PyCapsule_IsValid(): 1564. or *note PyErr_Occurred(): 1c97. to
     disambiguate.

 -- C Funzione: void *PyCapsule_Import (const char *name, int no_block)
     ' Parte del *note ABI Stabile: 776.'  Import a pointer to a C
     object from a capsule attribute in a module.  The 'name' parameter
     should specify the full name to the attribute, as in
     ‘module.attribute’.  The 'name' stored in the capsule must match
     this string exactly.

     This function splits 'name' on the ‘.’ character, and imports the
     first element.  It then processes further elements using attribute
     lookups.

     Return the capsule’s internal 'pointer' on success.  On failure,
     set an exception and return ‘NULL’.

          Nota: If 'name' points to an attribute of some submodule or
          subpackage, this submodule or subpackage must be previously
          imported using other means (for example, by using *note
          PyImport_ImportModule(): 3dc.) for the attribute lookups to
          succeed.

     Cambiato nella versione 3.3: 'no_block' has no effect anymore.

 -- C Funzione: int PyCapsule_IsValid (PyObject *capsule, const char
          *name)
     ' Parte del *note ABI Stabile: 776.'  Determines whether or not
     'capsule' is a valid capsule.  A valid capsule is non-‘NULL’,
     passes *note PyCapsule_CheckExact(): 5465, has a non-‘NULL’ pointer
     stored in it, and its internal name matches the 'name' parameter.
     (See *note PyCapsule_GetPointer(): 4f6f. for information on how
     capsule names are compared.)

     In other words, if *note PyCapsule_IsValid(): 1564. returns a true
     value, calls to any of the accessors (any function starting with
     ‘PyCapsule_Get’) are guaranteed to succeed.

     Return a nonzero value if the object is valid and matches the name
     passed in.  Return ‘0’ otherwise.  This function will not fail.

 -- C Funzione: int PyCapsule_SetContext (PyObject *capsule, void
          *context)
     ' Parte del *note ABI Stabile: 776.'  Set the context pointer
     inside 'capsule' to 'context'.

     Return ‘0’ on success.  Return nonzero and set an exception on
     failure.

 -- C Funzione: int PyCapsule_SetDestructor (PyObject *capsule,
          PyCapsule_Destructor destructor)
     ' Parte del *note ABI Stabile: 776.'  Set the destructor inside
     'capsule' to 'destructor'.

     Return ‘0’ on success.  Return nonzero and set an exception on
     failure.

 -- C Funzione: int PyCapsule_SetName (PyObject *capsule, const char
          *name)
     ' Parte del *note ABI Stabile: 776.'  Set the name inside 'capsule'
     to 'name'.  If non-‘NULL’, the name must outlive the capsule.  If
     the previous 'name' stored in the capsule was not ‘NULL’, no
     attempt is made to free it.

     Return ‘0’ on success.  Return nonzero and set an exception on
     failure.

 -- C Funzione: int PyCapsule_SetPointer (PyObject *capsule, void
          *pointer)
     ' Parte del *note ABI Stabile: 776.'  Set the void pointer inside
     'capsule' to 'pointer'.  The pointer may not be ‘NULL’.

     Return ‘0’ on success.  Return nonzero and set an exception on
     failure.


File: python.info,  Node: Frame Objects,  Next: Generator Objects,  Prev: Capsules<2>,  Up: Other Objects

7.9.6.21 Frame Objects
......................

 -- C Tipo: type PyFrameObject
     ' Parte del *note API Limitata: 776. (come una struttura opaca).'
     The C structure of the objects used to describe frame objects.

     There are no public members in this structure.

     Cambiato nella versione 3.11: The members of this structure were
     removed from the public C API. Refer to the *note What’s New entry:
     98c. for details.

The *note PyEval_GetFrame(): 1b21. and *note PyThreadState_GetFrame():
992. functions can be used to get a frame object.

See also *note Reflection: 523a.

 -- C Variabile: *note PyTypeObject: c9e. PyFrame_Type

     The type of frame objects.  It is the same object as *note
     types.FrameType: 1bd6. in the Python layer.

     Cambiato nella versione 3.11: Previously, this type was only
     available after including ‘<frameobject.h>’.

 -- C Funzione: *note PyFrameObject: 98d. *PyFrame_New (PyThreadState
          *tstate, PyCodeObject *code, PyObject *globals, PyObject
          *locals)

     Create a new frame object.  This function returns a *note strong
     reference: 5e2. to the new frame object on success, and returns
     ‘NULL’ with an exception set on failure.

 -- C Funzione: int PyFrame_Check (PyObject *obj)

     Return non-zero if 'obj' is a frame object.

     Cambiato nella versione 3.11: Previously, this function was only
     available after including ‘<frameobject.h>’.

 -- C Funzione: *note PyFrameObject: 98d. *PyFrame_GetBack
          (PyFrameObject *frame)
     'Valore di ritorno: Nuovo riferimento.'  Get the 'frame' next outer
     frame.

     Return a *note strong reference: 5e2, or ‘NULL’ if 'frame' has no
     outer frame.

     Added in version 3.9.

 -- C Funzione: *note PyObject: 5df. *PyFrame_GetBuiltins (PyFrameObject
          *frame)
     'Valore di ritorno: Nuovo riferimento.'  Get the 'frame'’s *note
     f_builtins: 2381. attribute.

     Return a *note strong reference: 5e2.  The result cannot be ‘NULL’.

     Added in version 3.11.

 -- C Funzione: *note PyCodeObject: 97c. *PyFrame_GetCode (PyFrameObject
          *frame)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.10.'  Get the 'frame' code.

     Return a *note strong reference: 5e2.

     The result (frame code) cannot be ‘NULL’.

     Added in version 3.9.

 -- C Funzione: *note PyObject: 5df. *PyFrame_GetGenerator
          (PyFrameObject *frame)
     'Valore di ritorno: Nuovo riferimento.'  Get the generator,
     coroutine, or async generator that owns this frame, or ‘NULL’ if
     this frame is not owned by a generator.  Does not raise an
     exception, even if the return value is ‘NULL’.

     Return a *note strong reference: 5e2, or ‘NULL’.

     Added in version 3.11.

 -- C Funzione: *note PyObject: 5df. *PyFrame_GetGlobals (PyFrameObject
          *frame)
     'Valore di ritorno: Nuovo riferimento.'  Get the 'frame'’s *note
     f_globals: 2380. attribute.

     Return a *note strong reference: 5e2.  The result cannot be ‘NULL’.

     Added in version 3.11.

 -- C Funzione: int PyFrame_GetLasti (PyFrameObject *frame)

     Get the 'frame'’s *note f_lasti: a8a. attribute.

     Returns -1 if ‘frame.f_lasti’ is ‘None’.

     Added in version 3.11.

 -- C Funzione: *note PyObject: 5df. *PyFrame_GetVar (PyFrameObject
          *frame, PyObject *name)
     'Valore di ritorno: Nuovo riferimento.'  Get the variable 'name' of
     'frame'.

        * Return a *note strong reference: 5e2. to the variable value on
          success.

        * Raise *note NameError: 452. and return ‘NULL’ if the variable
          does not exist.

        * Raise an exception and return ‘NULL’ on error.

     'name' type must be a *note str: 169.

     Added in version 3.12.

 -- C Funzione: *note PyObject: 5df. *PyFrame_GetVarString
          (PyFrameObject *frame, const char *name)
     'Valore di ritorno: Nuovo riferimento.'  Similar to *note
     PyFrame_GetVar(): 78a, but the variable name is a C string encoded
     in UTF-8.

     Added in version 3.12.

 -- C Funzione: *note PyObject: 5df. *PyFrame_GetLocals (PyFrameObject
          *frame)
     'Valore di ritorno: Nuovo riferimento.'  Get the 'frame'’s *note
     f_locals: 4a6. attribute.  If the frame refers to an *note
     optimized scope: 4a2, this returns a write-through proxy object
     that allows modifying the locals.  In all other cases (classes,
     modules, *note exec(): 4a3, *note eval(): 4a4.) it returns the
     mapping representing the frame locals directly (as described for
     *note locals(): 46f.).

     Return a *note strong reference: 5e2.

     Added in version 3.11.

     Cambiato nella versione 3.13: As part of PEP 667(1), return an
     instance of *note PyFrameLocalsProxy_Type: 5469.

 -- C Funzione: int PyFrame_GetLineNumber (PyFrameObject *frame)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Return
     the line number that 'frame' is currently executing.

* Menu:

* Frame Locals Proxies::
* Legacy Local Variable APIs::
* Internal Frames::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0667/


File: python.info,  Node: Frame Locals Proxies,  Next: Legacy Local Variable APIs,  Up: Frame Objects

7.9.6.22 Frame Locals Proxies
.............................

Added in version 3.13.

The *note f_locals: 4a6. attribute on a *note frame object: 8f0. is an
instance of a «frame-locals proxy».  The proxy object exposes a
write-through view of the underlying locals dictionary for the frame.
This ensures that the variables exposed by ‘f_locals’ are always up to
date with the live local variables in the frame itself.

See PEP 667(1) for more information.

 -- C Variabile: *note PyTypeObject: c9e. PyFrameLocalsProxy_Type

     The type of frame *note locals(): 46f. proxy objects.

 -- C Funzione: int PyFrameLocalsProxy_Check (PyObject *obj)

     Return non-zero if 'obj' is a frame *note locals(): 46f. proxy.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0667/


File: python.info,  Node: Legacy Local Variable APIs,  Next: Internal Frames,  Prev: Frame Locals Proxies,  Up: Frame Objects

7.9.6.23 Legacy Local Variable APIs
...................................

These APIs are *note soft deprecated: 23d.  As of Python 3.13, they do
nothing.  They exist solely for backwards compatibility.

 -- C Funzione: void PyFrame_LocalsToFast (PyFrameObject *f, int clear)

     This function is *note soft deprecated: 23d. and does nothing.

     Prior to Python 3.13, this function would copy the *note f_locals:
     4a6. attribute of 'f' to the internal «fast» array of local
     variables, allowing changes in frame objects to be visible to the
     interpreter.  If 'clear' was true, this function would process
     variables that were unset in the locals dictionary.

     Cambiato nella versione 3.13: This function now does nothing.

 -- C Funzione: void PyFrame_FastToLocals (PyFrameObject *f)

     This function is *note soft deprecated: 23d. and does nothing.

     Prior to Python 3.13, this function would copy the internal «fast»
     array of local variables (which is used by the interpreter) to the
     *note f_locals: 4a6. attribute of 'f', allowing changes in local
     variables to be visible to frame objects.

     Cambiato nella versione 3.13: This function now does nothing.

 -- C Funzione: int PyFrame_FastToLocalsWithError (PyFrameObject *f)

     This function is *note soft deprecated: 23d. and does nothing.

     Prior to Python 3.13, this function was similar to *note
     PyFrame_FastToLocals(): 546e, but would return ‘0’ on success, and
     ‘-1’ with an exception set on failure.

     Cambiato nella versione 3.13: This function now does nothing.

Vedi anche
..........

PEP 667(1)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0667/


File: python.info,  Node: Internal Frames,  Prev: Legacy Local Variable APIs,  Up: Frame Objects

7.9.6.24 Internal Frames
........................

Unless using PEP 523(1), you will not need this.

 -- C Struct: struct _PyInterpreterFrame

     The interpreter’s internal frame representation.

     Added in version 3.11.

 -- C Funzione: *note PyObject: 5df.
          *PyUnstable_InterpreterFrame_GetCode (struct
          _PyInterpreterFrame *frame);

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
          Return a *note strong reference: 5e2. to the code object for
          the frame.

     Added in version 3.12.

 -- C Funzione: int PyUnstable_InterpreterFrame_GetLasti (struct
          _PyInterpreterFrame *frame);

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Return the byte offset into the last executed instruction.

     Added in version 3.12.

 -- C Funzione: int PyUnstable_InterpreterFrame_GetLine (struct
          _PyInterpreterFrame *frame);

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Return the currently executing line number, or -1 if there is no
     line number.

     Added in version 3.12.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0523/


File: python.info,  Node: Generator Objects,  Next: Coroutine Objects<2>,  Prev: Frame Objects,  Up: Other Objects

7.9.6.25 Generator Objects
..........................

Generator objects are what Python uses to implement generator iterators.
They are normally created by iterating over a function that yields
values, rather than explicitly calling *note PyGen_New(): 5478. or *note
PyGen_NewWithQualName(): 5479.

 -- C Tipo: type PyGenObject

     The C structure used for generator objects.

 -- C Variabile: *note PyTypeObject: c9e. PyGen_Type

     The type object corresponding to generator objects.

 -- C Funzione: int PyGen_Check (PyObject *ob)

     Return true if 'ob' is a generator object; 'ob' must not be ‘NULL’.
     This function always succeeds.

 -- C Funzione: int PyGen_CheckExact (PyObject *ob)

     Return true if 'ob'’s type is *note PyGen_Type: 547b.; 'ob' must
     not be ‘NULL’.  This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyGen_New (PyFrameObject *frame)
     'Valore di ritorno: Nuovo riferimento.'  Create and return a new
     generator object based on the 'frame' object.  A reference to
     'frame' is stolen by this function.  The argument must not be
     ‘NULL’.

 -- C Funzione: *note PyObject: 5df. *PyGen_NewWithQualName
          (PyFrameObject *frame, PyObject *name, PyObject *qualname)
     'Valore di ritorno: Nuovo riferimento.'  Create and return a new
     generator object based on the 'frame' object, with ‘__name__’ and
     ‘__qualname__’ set to 'name' and 'qualname'.  A reference to
     'frame' is stolen by this function.  The 'frame' argument must not
     be ‘NULL’.

 -- C Funzione: *note PyCodeObject: 97c. *PyGen_GetCode (PyGenObject
          *gen)

     Return a new *note strong reference: 5e2. to the code object
     wrapped by 'gen'.  This function always succeeds.

* Menu:

* Asynchronous Generator Objects::
* Deprecated API: Deprecated API<5>.


File: python.info,  Node: Asynchronous Generator Objects,  Next: Deprecated API<5>,  Up: Generator Objects

7.9.6.26 Asynchronous Generator Objects
.......................................

Vedi anche
..........

PEP 525(1)

 -- C Variabile: *note PyTypeObject: c9e. PyAsyncGen_Type

     The type object corresponding to asynchronous generator objects.
     This is available as *note types.AsyncGeneratorType: 29cb. in the
     Python layer.

     Added in version 3.6.

 -- C Funzione: *note PyObject: 5df. *PyAsyncGen_New (PyFrameObject
          *frame, PyObject *name, PyObject *qualname)

     Create a new asynchronous generator wrapping 'frame', with
     ‘__name__’ and ‘__qualname__’ set to 'name' and 'qualname'.
     'frame' is stolen by this function and must not be ‘NULL’.

     On success, this function returns a *note strong reference: 5e2. to
     the new asynchronous generator.  On failure, this function returns
     ‘NULL’ with an exception set.

     Added in version 3.6.

 -- C Funzione: int PyAsyncGen_CheckExact (PyObject *op)

     Return true if 'op' is an asynchronous generator object, false
     otherwise.  This function always succeeds.

     Added in version 3.6.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0525/


File: python.info,  Node: Deprecated API<5>,  Prev: Asynchronous Generator Objects,  Up: Generator Objects

7.9.6.27 Deprecated API
.......................

 -- C Macro: PyAsyncGenASend_CheckExact (op)

     This is a *note soft deprecated: 23d. API that was included in
     Python’s C API by mistake.

     It is solely here for completeness; do not use this API.


File: python.info,  Node: Coroutine Objects<2>,  Next: Context Variables Objects,  Prev: Generator Objects,  Up: Other Objects

7.9.6.28 Coroutine Objects
..........................

Added in version 3.5.

Coroutine objects are what functions declared with an ‘async’ keyword
return.

 -- C Tipo: type PyCoroObject

     The C structure used for coroutine objects.

 -- C Variabile: *note PyTypeObject: c9e. PyCoro_Type

     The type object corresponding to coroutine objects.

 -- C Funzione: int PyCoro_CheckExact (PyObject *ob)

     Return true if 'ob'’s type is *note PyCoro_Type: 5489.; 'ob' must
     not be ‘NULL’.  This function always succeeds.

 -- C Funzione: *note PyObject: 5df. *PyCoro_New (PyFrameObject *frame,
          PyObject *name, PyObject *qualname)
     'Valore di ritorno: Nuovo riferimento.'  Create and return a new
     coroutine object based on the 'frame' object, with ‘__name__’ and
     ‘__qualname__’ set to 'name' and 'qualname'.  A reference to
     'frame' is stolen by this function.  The 'frame' argument must not
     be ‘NULL’.


File: python.info,  Node: Context Variables Objects,  Next: Objects for Type Hinting,  Prev: Coroutine Objects<2>,  Up: Other Objects

7.9.6.29 Context Variables Objects
..................................

Added in version 3.7.

Cambiato nella versione 3.7.1:

     Nota: In Python 3.7.1 the signatures of all context variables C
     APIs were 'changed' to use *note PyObject: 5df. pointers instead of
     *note PyContext: 548f, *note PyContextVar: 5490, and *note
     PyContextToken: 5491, e.g.:

          // in 3.7.0:
          PyContext *PyContext_New(void);

          // in 3.7.1+:
          PyObject *PyContext_New(void);

     See bpo-34762(1) for more details.

This section details the public C API for the *note contextvars: 28.
module.

 -- C Tipo: type PyContext

     The C structure used to represent a *note contextvars.Context: 177.
     object.

 -- C Tipo: type PyContextVar

     The C structure used to represent a *note contextvars.ContextVar:
     185d. object.

 -- C Tipo: type PyContextToken

     The C structure used to represent a *note contextvars.Token: 1e2.
     object.

 -- C Variabile: *note PyTypeObject: c9e. PyContext_Type

     The type object representing the 'context' type.

 -- C Variabile: *note PyTypeObject: c9e. PyContextVar_Type

     The type object representing the 'context variable' type.

 -- C Variabile: *note PyTypeObject: c9e. PyContextToken_Type

     The type object representing the 'context variable token' type.

Type-check macros:

 -- C Funzione: int PyContext_CheckExact (PyObject *o)

     Return true if 'o' is of type *note PyContext_Type: 5492.  'o' must
     not be ‘NULL’.  This function always succeeds.

 -- C Funzione: int PyContextVar_CheckExact (PyObject *o)

     Return true if 'o' is of type *note PyContextVar_Type: 5493.  'o'
     must not be ‘NULL’.  This function always succeeds.

 -- C Funzione: int PyContextToken_CheckExact (PyObject *o)

     Return true if 'o' is of type *note PyContextToken_Type: 5494.  'o'
     must not be ‘NULL’.  This function always succeeds.

Context object management functions:

 -- C Funzione: *note PyObject: 5df. *PyContext_New (void)
     'Valore di ritorno: Nuovo riferimento.'  Create a new empty context
     object.  Returns ‘NULL’ if an error has occurred.

 -- C Funzione: *note PyObject: 5df. *PyContext_Copy (PyObject *ctx)
     'Valore di ritorno: Nuovo riferimento.'  Create a shallow copy of
     the passed 'ctx' context object.  Returns ‘NULL’ if an error has
     occurred.

 -- C Funzione: *note PyObject: 5df. *PyContext_CopyCurrent (void)
     'Valore di ritorno: Nuovo riferimento.'  Create a shallow copy of
     the current thread context.  Returns ‘NULL’ if an error has
     occurred.

 -- C Funzione: int PyContext_Enter (PyObject *ctx)

     Set 'ctx' as the current context for the current thread.  Returns
     ‘0’ on success, and ‘-1’ on error.

 -- C Funzione: int PyContext_Exit (PyObject *ctx)

     Deactivate the 'ctx' context and restore the previous context as
     the current context for the current thread.  Returns ‘0’ on
     success, and ‘-1’ on error.

 -- C Funzione: int PyContext_AddWatcher (PyContext_WatchCallback
          callback)

     Register 'callback' as a context object watcher for the current
     interpreter.  Return an ID which may be passed to *note
     PyContext_ClearWatcher(): 197b.  In case of error (e.g.  no more
     watcher IDs available), return ‘-1’ and set an exception.

     Added in version 3.14.

 -- C Funzione: int PyContext_ClearWatcher (int watcher_id)

     Clear watcher identified by 'watcher_id' previously returned from
     *note PyContext_AddWatcher(): 197a. for the current interpreter.
     Return ‘0’ on success, or ‘-1’ and set an exception on error (e.g.
     if the given 'watcher_id' was never registered.)

     Added in version 3.14.

 -- C Tipo: type PyContextEvent

     Enumeration of possible context object watcher events:

        - ‘Py_CONTEXT_SWITCHED’: The *note current context: 194c. has
          switched to a different context.  The object passed to the
          watch callback is the now-current *note contextvars.Context:
          177. object, or None if no context is current.

     Added in version 3.14.

 -- C Tipo: typedef int (*PyContext_WatchCallback)(*note PyContextEvent:
          549d. event, *note PyObject: 5df. *obj)

     Context object watcher callback function.  The object passed to the
     callback is event-specific; see *note PyContextEvent: 549d. for
     details.

     If the callback returns with an exception set, it must return ‘-1’;
     this exception will be printed as an unraisable exception using
     *note PyErr_FormatUnraisable(): 5f1.  Otherwise it should return
     ‘0’.

     There may already be a pending exception set on entry to the
     callback.  In this case, the callback should return ‘0’ with the
     same exception still set.  This means the callback may not call any
     other API that can set an exception unless it saves and clears the
     exception state first, and restores it before returning.

     Added in version 3.14.

Context variable functions:

 -- C Funzione: *note PyObject: 5df. *PyContextVar_New (const char
          *name, PyObject *def)
     'Valore di ritorno: Nuovo riferimento.'  Create a new ‘ContextVar’
     object.  The 'name' parameter is used for introspection and debug
     purposes.  The 'def' parameter specifies a default value for the
     context variable, or ‘NULL’ for no default.  If an error has
     occurred, this function returns ‘NULL’.

 -- C Funzione: int PyContextVar_Get (PyObject *var, PyObject
          *default_value, PyObject **value)

     Get the value of a context variable.  Returns ‘-1’ if an error has
     occurred during lookup, and ‘0’ if no error occurred, whether or
     not a value was found.

     If the context variable was found, 'value' will be a pointer to it.
     If the context variable was 'not' found, 'value' will point to:

        - 'default_value', if not ‘NULL’;

        - the default value of 'var', if not ‘NULL’;

        - ‘NULL’

     Except for ‘NULL’, the function returns a new reference.

 -- C Funzione: *note PyObject: 5df. *PyContextVar_Set (PyObject *var,
          PyObject *value)
     'Valore di ritorno: Nuovo riferimento.'  Set the value of 'var' to
     'value' in the current context.  Returns a new token object for
     this change, or ‘NULL’ if an error has occurred.

 -- C Funzione: int PyContextVar_Reset (PyObject *var, PyObject *token)

     Reset the state of the 'var' context variable to that it was in
     before *note PyContextVar_Set(): 54a1. that returned the 'token'
     was called.  This function returns ‘0’ on success and ‘-1’ on
     error.

   ---------- Footnotes ----------

   (1) https://bugs.python.org/issue?@action=redirect&bpo=34762


File: python.info,  Node: Objects for Type Hinting,  Prev: Context Variables Objects,  Up: Other Objects

7.9.6.30 Objects for Type Hinting
.................................

Various built-in types for type hinting are provided.  Currently, two
types exist – *note GenericAlias: 8c2. and *note Union: 9c7.  Only
‘GenericAlias’ is exposed to C.

 -- C Funzione: *note PyObject: 5df. *Py_GenericAlias (PyObject *origin,
          PyObject *args)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.9.'  Create a
     *note GenericAlias: 8c2. object.  Equivalent to calling the Python
     class *note types.GenericAlias: 9ee.  The 'origin' and 'args'
     arguments set the ‘GenericAlias’“s ‘__origin__’ and ‘__args__’
     attributes respectively.  'origin' should be a *note PyTypeObject:
     c9e.*, and 'args' can be a *note PyTupleObject: 51fc.* or any
     ‘PyObject*’.  If 'args' passed is not a tuple, a 1-tuple is
     automatically constructed and ‘__args__’ is set to ‘(args,)’.
     Minimal checking is done for the arguments, so the function will
     succeed even if 'origin' is not a type.  The ‘GenericAlias’“s
     ‘__parameters__’ attribute is constructed lazily from ‘__args__’.
     On failure, an exception is raised and ‘NULL’ is returned.

     Here’s an example of how to make an extension type generic:

          ...
          static PyMethodDef my_obj_methods[] = {
              // Other methods.
              ...
              {"__class_getitem__", Py_GenericAlias, METH_O|METH_CLASS, "See PEP 585"}
              ...
          }

     Vedi anche
     ..........

     The data model method *note __class_getitem__(): 944.

     Added in version 3.9.

 -- C Variabile: *note PyTypeObject: c9e. Py_GenericAliasType
     ' Parte del *note ABI Stabile: 776. dalla versione 3.9.'  The C
     type of the object returned by *note Py_GenericAlias(): 5103.
     Equivalent to *note types.GenericAlias: 9ee. in Python.

     Added in version 3.9.


File: python.info,  Node: C API for extension modules,  Prev: Other Objects,  Up: Concrete Objects Layer

7.9.7 C API for extension modules
---------------------------------

* Menu:

* Curses C API::
* Internal data::
* DateTime Objects: DateTime Objects<2>.
* Internal data: Internal data<2>.


File: python.info,  Node: Curses C API,  Next: Internal data,  Up: C API for extension modules

7.9.7.1 Curses C API
....................

*note curses: 2f. exposes a small C interface for extension modules.
Consumers must include the header file ‘py_curses.h’ (which is not
included by default by ‘Python.h’) and *note import_curses(): 54aa. must
be invoked, usually as part of the module initialisation function, to
populate *note PyCurses_API: 54ab.

     Avvertimento: Neither the C API nor the pure Python *note curses:
     2f. module are compatible with subinterpreters.

 -- C Macro: import_curses ()

     Import the curses C API. The macro does not need a semi-colon to be
     called.

     On success, populate the *note PyCurses_API: 54ab. pointer.

     On failure, set *note PyCurses_API: 54ab. to NULL and set an
     exception.  The caller must check if an error occurred via *note
     PyErr_Occurred(): 1c97.:

          import_curses();  // semi-colon is optional but recommended
          if (PyErr_Occurred()) { /* cleanup */ }

 -- C Variabile: void **PyCurses_API

     Dynamically allocated object containing the curses C API. This
     variable is only available once *note import_curses: 54aa.
     succeeds.

     ‘PyCurses_API[0]’ corresponds to *note PyCursesWindow_Type: 54ac.

     ‘PyCurses_API[1]’, ‘PyCurses_API[2]’, and ‘PyCurses_API[3]’ are
     pointers to predicate functions of type ‘int (*)(void)’.

     When called, these predicates return whether *note
     curses.setupterm(): 348b, *note curses.initscr(): 18f7, and *note
     curses.start_color(): 348c. have been called respectively.

     See also the convenience macros *note PyCursesSetupTermCalled:
     54ad, *note PyCursesInitialised: 54ae, and *note
     PyCursesInitialisedColor: 54af.

          Nota: The number of entries in this structure is subject to
          changes.  Consider using *note PyCurses_API_pointers: 54b0. to
          check if new fields are available or not.

 -- C Macro: PyCurses_API_pointers

     The number of accessible fields (‘4’) in *note PyCurses_API: 54ab.
     This number is incremented whenever new fields are added.

 -- C Variabile: *note PyTypeObject: c9e. PyCursesWindow_Type

     The *note heap type: b60. corresponding to *note curses.window:
     129d.

 -- C Funzione: int PyCursesWindow_Check (PyObject *op)

     Return true if 'op' is a *note curses.window: 129d. instance, false
     otherwise.

The following macros are convenience macros expanding into C statements.
In particular, they can only be used as ‘macro;’ or ‘macro’, but not
‘macro()’ or ‘macro();’.

 -- C Macro: PyCursesSetupTermCalled

     Macro checking if *note curses.setupterm(): 348b. has been called.

     The macro expansion is roughly equivalent to:

          {
              typedef int (*predicate_t)(void);
              predicate_t was_setupterm_called = (predicate_t)PyCurses_API[1];
              if (!was_setupterm_called()) {
                  return NULL;
              }
          }

 -- C Macro: PyCursesInitialised

     Macro checking if *note curses.initscr(): 18f7. has been called.

     The macro expansion is roughly equivalent to:

          {
              typedef int (*predicate_t)(void);
              predicate_t was_initscr_called = (predicate_t)PyCurses_API[2];
              if (!was_initscr_called()) {
                  return NULL;
              }
          }

 -- C Macro: PyCursesInitialisedColor

     Macro checking if *note curses.start_color(): 348c. has been
     called.

     The macro expansion is roughly equivalent to:

          {
              typedef int (*predicate_t)(void);
              predicate_t was_start_color_called = (predicate_t)PyCurses_API[3];
              if (!was_start_color_called()) {
                  return NULL;
              }
          }


File: python.info,  Node: Internal data,  Next: DateTime Objects<2>,  Prev: Curses C API,  Up: C API for extension modules

7.9.7.2 Internal data
.....................

The following objects are exposed by the C API but should be considered
internal-only.

 -- C Macro: PyCurses_CAPSULE_NAME

     Name of the curses capsule to pass to *note PyCapsule_Import():
     1bf8.

     Internal usage only.  Use *note import_curses: 54aa. instead.


File: python.info,  Node: DateTime Objects<2>,  Next: Internal data<2>,  Prev: Internal data,  Up: C API for extension modules

7.9.7.3 DateTime Objects
........................

Various date and time objects are supplied by the *note datetime: 34.
module.  Before using any of these functions, the header file
‘datetime.h’ must be included in your source (note that this is not
included by ‘Python.h’), and the macro *note PyDateTime_IMPORT: 54b7.
must be invoked, usually as part of the module initialisation function.
The macro puts a pointer to a C structure into a static variable, *note
PyDateTimeAPI: 54b8, that is used by the following macros.

 -- C Macro: PyDateTime_IMPORT ()

     Import the datetime C API.

     On success, populate the *note PyDateTimeAPI: 54b8. pointer.  On
     failure, set *note PyDateTimeAPI: 54b8. to ‘NULL’ and set an
     exception.  The caller must check if an error occurred via *note
     PyErr_Occurred(): 1c97.:

          PyDateTime_IMPORT;
          if (PyErr_Occurred()) { /* cleanup */ }

          Avvertimento: This is not compatible with subinterpreters.

 -- C Tipo: type PyDateTime_CAPI

     Structure containing the fields for the datetime C API.

     The fields of this structure are private and subject to change.

     Do not use this directly; prefer ‘PyDateTime_*’ APIs instead.

 -- C Variabile: *note PyDateTime_CAPI: 54b9. *PyDateTimeAPI

     Dynamically allocated object containing the datetime C API.

     This variable is only available once *note PyDateTime_IMPORT: 54b7.
     succeeds.

 -- C Tipo: type PyDateTime_Date

     This subtype of *note PyObject: 5df. represents a Python date
     object.

 -- C Tipo: type PyDateTime_DateTime

     This subtype of *note PyObject: 5df. represents a Python datetime
     object.

 -- C Tipo: type PyDateTime_Time

     This subtype of *note PyObject: 5df. represents a Python time
     object.

 -- C Tipo: type PyDateTime_Delta

     This subtype of *note PyObject: 5df. represents the difference
     between two datetime values.

 -- C Variabile: *note PyTypeObject: c9e. PyDateTime_DateType

     This instance of *note PyTypeObject: c9e. represents the Python
     date type; it is the same object as *note datetime.date: 1fa. in
     the Python layer.

 -- C Variabile: *note PyTypeObject: c9e. PyDateTime_DateTimeType

     This instance of *note PyTypeObject: c9e. represents the Python
     datetime type; it is the same object as *note datetime.datetime:
     4e3. in the Python layer.

 -- C Variabile: *note PyTypeObject: c9e. PyDateTime_TimeType

     This instance of *note PyTypeObject: c9e. represents the Python
     time type; it is the same object as *note datetime.time: 1fb. in
     the Python layer.

 -- C Variabile: *note PyTypeObject: c9e. PyDateTime_DeltaType

     This instance of *note PyTypeObject: c9e. represents the Python
     type for the difference between two datetime values; it is the same
     object as *note datetime.timedelta: bc5. in the Python layer.

 -- C Variabile: *note PyTypeObject: c9e. PyDateTime_TZInfoType

     This instance of *note PyTypeObject: c9e. represents the Python
     time zone info type; it is the same object as *note
     datetime.tzinfo: 7f7. in the Python layer.

Macro for access to the UTC singleton:

 -- C Variabile: *note PyObject: 5df. *PyDateTime_TimeZone_UTC

     Returns the time zone singleton representing UTC, the same object
     as *note datetime.timezone.utc: 828.

     Added in version 3.7.

Type-check macros:

 -- C Funzione: int PyDate_Check (PyObject *ob)

     Return true if 'ob' is of type *note PyDateTime_DateType: 54be. or
     a subtype of ‘PyDateTime_DateType’.  'ob' must not be ‘NULL’.  This
     function always succeeds.

 -- C Funzione: int PyDate_CheckExact (PyObject *ob)

     Return true if 'ob' is of type *note PyDateTime_DateType: 54be.
     'ob' must not be ‘NULL’.  This function always succeeds.

 -- C Funzione: int PyDateTime_Check (PyObject *ob)

     Return true if 'ob' is of type *note PyDateTime_DateTimeType: 54bf.
     or a subtype of ‘PyDateTime_DateTimeType’.  'ob' must not be
     ‘NULL’.  This function always succeeds.

 -- C Funzione: int PyDateTime_CheckExact (PyObject *ob)

     Return true if 'ob' is of type *note PyDateTime_DateTimeType: 54bf.
     'ob' must not be ‘NULL’.  This function always succeeds.

 -- C Funzione: int PyTime_Check (PyObject *ob)

     Return true if 'ob' is of type *note PyDateTime_TimeType: 54c0. or
     a subtype of ‘PyDateTime_TimeType’.  'ob' must not be ‘NULL’.  This
     function always succeeds.

 -- C Funzione: int PyTime_CheckExact (PyObject *ob)

     Return true if 'ob' is of type *note PyDateTime_TimeType: 54c0.
     'ob' must not be ‘NULL’.  This function always succeeds.

 -- C Funzione: int PyDelta_Check (PyObject *ob)

     Return true if 'ob' is of type *note PyDateTime_DeltaType: 54c1. or
     a subtype of ‘PyDateTime_DeltaType’.  'ob' must not be ‘NULL’.
     This function always succeeds.

 -- C Funzione: int PyDelta_CheckExact (PyObject *ob)

     Return true if 'ob' is of type *note PyDateTime_DeltaType: 54c1.
     'ob' must not be ‘NULL’.  This function always succeeds.

 -- C Funzione: int PyTZInfo_Check (PyObject *ob)

     Return true if 'ob' is of type *note PyDateTime_TZInfoType: 54c2.
     or a subtype of ‘PyDateTime_TZInfoType’.  'ob' must not be ‘NULL’.
     This function always succeeds.

 -- C Funzione: int PyTZInfo_CheckExact (PyObject *ob)

     Return true if 'ob' is of type *note PyDateTime_TZInfoType: 54c2.
     'ob' must not be ‘NULL’.  This function always succeeds.

Macros to create objects:

 -- C Funzione: *note PyObject: 5df. *PyDate_FromDate (int year, int
          month, int day)
     'Valore di ritorno: Nuovo riferimento.'  Return a *note
     datetime.date: 1fa. object with the specified year, month and day.

 -- C Funzione: *note PyObject: 5df. *PyDateTime_FromDateAndTime (int
          year, int month, int day, int hour, int minute, int second,
          int usecond)
     'Valore di ritorno: Nuovo riferimento.'  Return a *note
     datetime.datetime: 4e3. object with the specified year, month, day,
     hour, minute, second and microsecond.

 -- C Funzione: *note PyObject: 5df. *PyDateTime_FromDateAndTimeAndFold
          (int year, int month, int day, int hour, int minute, int
          second, int usecond, int fold)
     'Valore di ritorno: Nuovo riferimento.'  Return a *note
     datetime.datetime: 4e3. object with the specified year, month, day,
     hour, minute, second, microsecond and fold.

     Added in version 3.6.

 -- C Funzione: *note PyObject: 5df. *PyTime_FromTime (int hour, int
          minute, int second, int usecond)
     'Valore di ritorno: Nuovo riferimento.'  Return a *note
     datetime.time: 1fb. object with the specified hour, minute, second
     and microsecond.

 -- C Funzione: *note PyObject: 5df. *PyTime_FromTimeAndFold (int hour,
          int minute, int second, int usecond, int fold)
     'Valore di ritorno: Nuovo riferimento.'  Return a *note
     datetime.time: 1fb. object with the specified hour, minute, second,
     microsecond and fold.

     Added in version 3.6.

 -- C Funzione: *note PyObject: 5df. *PyDelta_FromDSU (int days, int
          seconds, int useconds)
     'Valore di ritorno: Nuovo riferimento.'  Return a *note
     datetime.timedelta: bc5. object representing the given number of
     days, seconds and microseconds.  Normalization is performed so that
     the resulting number of microseconds and seconds lie in the ranges
     documented for *note datetime.timedelta: bc5. objects.

 -- C Funzione: *note PyObject: 5df. *PyTimeZone_FromOffset (PyObject
          *offset)
     'Valore di ritorno: Nuovo riferimento.'  Return a *note
     datetime.timezone: 12c7. object with an unnamed fixed offset
     represented by the 'offset' argument.

     Added in version 3.7.

 -- C Funzione: *note PyObject: 5df. *PyTimeZone_FromOffsetAndName
          (PyObject *offset, PyObject *name)
     'Valore di ritorno: Nuovo riferimento.'  Return a *note
     datetime.timezone: 12c7. object with a fixed offset represented by
     the 'offset' argument and with tzname 'name'.

     Added in version 3.7.

Macros to extract fields from date objects.  The argument must be an
instance of *note PyDateTime_Date: 54ba, including subclasses (such as
*note PyDateTime_DateTime: 54bb.).  The argument must not be ‘NULL’, and
the type is not checked:

 -- C Funzione: int PyDateTime_GET_YEAR (PyDateTime_Date *o)

     Return the year, as a positive int.

 -- C Funzione: int PyDateTime_GET_MONTH (PyDateTime_Date *o)

     Return the month, as an int from 1 through 12.

 -- C Funzione: int PyDateTime_GET_DAY (PyDateTime_Date *o)

     Return the day, as an int from 1 through 31.

Macros to extract fields from datetime objects.  The argument must be an
instance of *note PyDateTime_DateTime: 54bb, including subclasses.  The
argument must not be ‘NULL’, and the type is not checked:

 -- C Funzione: int PyDateTime_DATE_GET_HOUR (PyDateTime_DateTime *o)

     Return the hour, as an int from 0 through 23.

 -- C Funzione: int PyDateTime_DATE_GET_MINUTE (PyDateTime_DateTime *o)

     Return the minute, as an int from 0 through 59.

 -- C Funzione: int PyDateTime_DATE_GET_SECOND (PyDateTime_DateTime *o)

     Return the second, as an int from 0 through 59.

 -- C Funzione: int PyDateTime_DATE_GET_MICROSECOND (PyDateTime_DateTime
          *o)

     Return the microsecond, as an int from 0 through 999999.

 -- C Funzione: int PyDateTime_DATE_GET_FOLD (PyDateTime_DateTime *o)

     Return the fold, as an int from 0 through 1.

     Added in version 3.6.

 -- C Funzione: *note PyObject: 5df. *PyDateTime_DATE_GET_TZINFO
          (PyDateTime_DateTime *o)

     Return the tzinfo (which may be ‘None’).

     Added in version 3.10.

Macros to extract fields from time objects.  The argument must be an
instance of *note PyDateTime_Time: 54bc, including subclasses.  The
argument must not be ‘NULL’, and the type is not checked:

 -- C Funzione: int PyDateTime_TIME_GET_HOUR (PyDateTime_Time *o)

     Return the hour, as an int from 0 through 23.

 -- C Funzione: int PyDateTime_TIME_GET_MINUTE (PyDateTime_Time *o)

     Return the minute, as an int from 0 through 59.

 -- C Funzione: int PyDateTime_TIME_GET_SECOND (PyDateTime_Time *o)

     Return the second, as an int from 0 through 59.

 -- C Funzione: int PyDateTime_TIME_GET_MICROSECOND (PyDateTime_Time *o)

     Return the microsecond, as an int from 0 through 999999.

 -- C Funzione: int PyDateTime_TIME_GET_FOLD (PyDateTime_Time *o)

     Return the fold, as an int from 0 through 1.

     Added in version 3.6.

 -- C Funzione: *note PyObject: 5df. *PyDateTime_TIME_GET_TZINFO
          (PyDateTime_Time *o)

     Return the tzinfo (which may be ‘None’).

     Added in version 3.10.

Macros to extract fields from time delta objects.  The argument must be
an instance of *note PyDateTime_Delta: 54bd, including subclasses.  The
argument must not be ‘NULL’, and the type is not checked:

 -- C Funzione: int PyDateTime_DELTA_GET_DAYS (PyDateTime_Delta *o)

     Return the number of days, as an int from -999999999 to 999999999.

     Added in version 3.3.

 -- C Funzione: int PyDateTime_DELTA_GET_SECONDS (PyDateTime_Delta *o)

     Return the number of seconds, as an int from 0 through 86399.

     Added in version 3.3.

 -- C Funzione: int PyDateTime_DELTA_GET_MICROSECONDS (PyDateTime_Delta
          *o)

     Return the number of microseconds, as an int from 0 through 999999.

     Added in version 3.3.

Macros for the convenience of modules implementing the DB API:

 -- C Funzione: *note PyObject: 5df. *PyDateTime_FromTimestamp (PyObject
          *args)
     'Valore di ritorno: Nuovo riferimento.'  Create and return a new
     *note datetime.datetime: 4e3. object given an argument tuple
     suitable for passing to *note datetime.datetime.fromtimestamp():
     713.

 -- C Funzione: *note PyObject: 5df. *PyDate_FromTimestamp (PyObject
          *args)
     'Valore di ritorno: Nuovo riferimento.'  Create and return a new
     *note datetime.date: 1fa. object given an argument tuple suitable
     for passing to *note datetime.date.fromtimestamp(): dcf.


File: python.info,  Node: Internal data<2>,  Prev: DateTime Objects<2>,  Up: C API for extension modules

7.9.7.4 Internal data
.....................

The following symbols are exposed by the C API but should be considered
internal-only.

 -- C Macro: PyDateTime_CAPSULE_NAME

     Name of the datetime capsule to pass to *note PyCapsule_Import():
     1bf8.

     Internal usage only.  Use *note PyDateTime_IMPORT: 54b7. instead.


File: python.info,  Node: Initialization Finalization and Threads,  Next: Python Initialization Configuration,  Prev: Concrete Objects Layer,  Up: Python/C API Reference Manual

7.10 Initialization, Finalization, and Threads
==============================================

See *note Python Initialization Configuration: 646. for details on how
to configure the interpreter prior to initialization.

* Menu:

* Before Python Initialization::
* Global configuration variables::
* Initializing and finalizing the interpreter::
* Process-wide parameters::
* Thread State and the Global Interpreter Lock::
* Sub-interpreter support::
* Asynchronous Notifications::
* Profiling and Tracing::
* Reference tracing::
* Advanced Debugger Support::
* Thread Local Storage Support::
* Synchronization Primitives: Synchronization Primitives<2>.
* Operating System Thread APIs::


File: python.info,  Node: Before Python Initialization,  Next: Global configuration variables,  Up: Initialization Finalization and Threads

7.10.1 Before Python Initialization
-----------------------------------

In an application embedding Python, the *note Py_Initialize(): 460.
function must be called before using any other Python/C API functions;
with the exception of a few functions and the *note global configuration
variables: 54eb.

The following functions can be safely called before Python is
initialized:

   * Functions that initialize the interpreter:

        * *note Py_Initialize(): 460.

        * *note Py_InitializeEx(): 510b.

        * *note Py_InitializeFromConfig(): 3f6.

        * *note Py_BytesMain(): bba.

        * *note Py_Main(): e20.

        * the runtime pre-initialization functions covered in *note
          Python Initialization Configuration: 646.

   * Configuration functions:

        * *note PyImport_AppendInittab(): 1b04.

        * *note PyImport_ExtendInittab(): 1b05.

        * ‘PyInitFrozenExtensions()’

        * *note PyMem_SetAllocator(): 7a9.

        * *note PyMem_SetupDebugHooks(): e66.

        * *note PyObject_SetArenaAllocator(): 54ec.

        * *note Py_SetProgramName(): 199e.

        * *note Py_SetPythonHome(): 199d.

        * *note PySys_ResetWarnOptions(): 3f4.

        * the configuration functions covered in *note Python
          Initialization Configuration: 646.

   * Informative functions:

        * *note Py_IsInitialized(): 4f29.

        * *note PyMem_GetAllocator(): 54ed.

        * *note PyObject_GetArenaAllocator(): 54ee.

        * *note Py_GetBuildInfo(): 1639.

        * *note Py_GetCompiler(): 5105.

        * *note Py_GetCopyright(): 5106.

        * *note Py_GetPlatform(): 5107.

        * *note Py_GetVersion(): 5109.

        * *note Py_IsInitialized(): 4f29.

   * Utilities:

        * *note Py_DecodeLocale(): dc2.

        * the status reporting and utility functions covered in *note
          Python Initialization Configuration: 646.

   * Memory allocators:

        * *note PyMem_RawMalloc(): 631.

        * *note PyMem_RawRealloc(): 633.

        * *note PyMem_RawCalloc(): 632.

        * *note PyMem_RawFree(): 634.

   * Synchronization:

        * *note PyMutex_Lock(): 5d0.

        * *note PyMutex_Unlock(): 5d1.

     Nota: Despite their apparent similarity to some of the functions
     listed above, the following functions 'should not be called' before
     the interpreter has been initialized: *note Py_EncodeLocale(): dc3,
     *note Py_GetPath(): 3e3, *note Py_GetPrefix(): 3e5, *note
     Py_GetExecPrefix(): 3e9, *note Py_GetProgramFullPath(): 3ec, *note
     Py_GetPythonHome(): 3ef, *note Py_GetProgramName(): 3ee, *note
     PyEval_InitThreads(): 19a1, and *note Py_RunMain(): bbe.


File: python.info,  Node: Global configuration variables,  Next: Initializing and finalizing the interpreter,  Prev: Before Python Initialization,  Up: Initialization Finalization and Threads

7.10.2 Global configuration variables
-------------------------------------

Python has variables for the global configuration to control different
features and options.  By default, these flags are controlled by *note
command line options: 2104.

When a flag is set by an option, the value of the flag is the number of
times that the option was set.  For example, ‘-b’ sets *note
Py_BytesWarningFlag: 406. to 1 and ‘-bb’ sets *note Py_BytesWarningFlag:
406. to 2.

 -- C Variabile: int Py_BytesWarningFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.bytes_warning: 407. should be used instead, see *note
     Python Initialization Configuration: 646.

     Issue a warning when comparing *note bytes: 192. or *note
     bytearray: 344. with *note str: 169. or *note bytes: 192. with
     *note int: 19b.  Issue an error if greater or equal to ‘2’.

     Set by the *note -b: 7fa. option.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_DebugFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.parser_debug: 3f9. should be used instead, see *note
     Python Initialization Configuration: 646.

     Turn on parser debugging output (for expert only, depending on
     compilation options).

     Set by the *note -d: 210c. option and the *note PYTHONDEBUG: 210d.
     environment variable.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_DontWriteBytecodeFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.write_bytecode: 40d. should be used instead, see *note
     Python Initialization Configuration: 646.

     If set to non-zero, Python won’t try to write ‘.pyc’ files on the
     import of source modules.

     Set by the *note -B: 15d4. option and the *note
     PYTHONDONTWRITEBYTECODE: 15d5. environment variable.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_FrozenFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.pathconfig_warnings: 409. should be used instead, see
     *note Python Initialization Configuration: 646.

     Suppress error messages when calculating the module search path in
     *note Py_GetPath(): 3e3.

     Private flag used by ‘_freeze_module’ and ‘frozenmain’ programs.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_HashRandomizationFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.hash_seed: 414. and *note PyConfig.use_hash_seed: 413.
     should be used instead, see *note Python Initialization
     Configuration: 646.

     Set to ‘1’ if the *note PYTHONHASHSEED: 127f. environment variable
     is set to a non-empty string.

     If the flag is non-zero, read the *note PYTHONHASHSEED: 127f.
     environment variable to initialize the secret hash seed.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_IgnoreEnvironmentFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.use_environment: 40b. should be used instead, see *note
     Python Initialization Configuration: 646.

     Ignore all ‘PYTHON*’ environment variables, e.g.  *note PYTHONPATH:
     121f. and *note PYTHONHOME: 3f0, that might be set.

     Set by the *note -E: b58. and *note -I: b59. options.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_InspectFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.inspect: 401. should be used instead, see *note Python
     Initialization Configuration: 646.

     When a script is passed as first argument or the *note -c: 1a8.
     option is used, enter interactive mode after executing the script
     or the command, even when *note sys.stdin: 760. does not appear to
     be a terminal.

     Set by the *note -i: 16e2. option and the *note PYTHONINSPECT:
     16e1. environment variable.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_InteractiveFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.interactive: 3ff. should be used instead, see *note Python
     Initialization Configuration: 646.

     Set by the *note -i: 16e2. option.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_IsolatedFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.isolated: 416. should be used instead, see *note Python
     Initialization Configuration: 646.

     Run Python in isolated mode.  In isolated mode *note sys.path: 3e4.
     contains neither the script’s directory nor the user’s
     site-packages directory.

     Set by the *note -I: b59. option.

     Added in version 3.4.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_LegacyWindowsFSEncodingFlag

     This API is kept for backward compatibility: setting *note
     PyPreConfig.legacy_windows_fs_encoding: 418. should be used
     instead, see *note Python Initialization Configuration: 646.

     If the flag is non-zero, use the ‘mbcs’ encoding with ‘replace’
     error handler, instead of the UTF-8 encoding with ‘surrogatepass’
     error handler, for the *note filesystem encoding and error handler:
     75e.

     Set to ‘1’ if the *note PYTHONLEGACYWINDOWSFSENCODING: 33f.
     environment variable is set to a non-empty string.

     See PEP 529(1) for more details.

     *note Availability: 2128.: Windows.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_LegacyWindowsStdioFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.legacy_windows_stdio: 41a. should be used instead, see
     *note Python Initialization Configuration: 646.

     If the flag is non-zero, use *note io.FileIO: 1517. instead of
     ‘io._WindowsConsoleIO’ for *note sys: df. standard streams.

     Set to ‘1’ if the *note PYTHONLEGACYWINDOWSSTDIO: e57. environment
     variable is set to a non-empty string.

     See PEP 528(2) for more details.

     *note Availability: 2128.: Windows.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_NoSiteFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.site_import: 405. should be used instead, see *note Python
     Initialization Configuration: 646.

     Disable the import of the module *note site: cc. and the
     site-dependent manipulations of *note sys.path: 3e4. that it
     entails.  Also disable these manipulations if *note site: cc. is
     explicitly imported later (call *note site.main(): 2110. if you
     want them to be triggered).

     Set by the *note -S: 13b0. option.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_NoUserSiteDirectory

     This API is kept for backward compatibility: setting *note
     PyConfig.user_site_directory: 40f. should be used instead, see
     *note Python Initialization Configuration: 646.

     Don’t add the *note user site-packages directory: 210f. to *note
     sys.path: 3e4.

     Set by the *note -s: 1596. and *note -I: b59. options, and the
     *note PYTHONNOUSERSITE: 1597. environment variable.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_OptimizeFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.optimization_level: 403. should be used instead, see *note
     Python Initialization Configuration: 646.

     Set by the *note -O: 18c. option and the *note PYTHONOPTIMIZE:
     210e. environment variable.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_QuietFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.quiet: 3fd. should be used instead, see *note Python
     Initialization Configuration: 646.

     Don’t display the copyright and version messages even in
     interactive mode.

     Set by the *note -q: 1765. option.

     Added in version 3.2.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_UnbufferedStdioFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.buffered_stdio: 411. should be used instead, see *note
     Python Initialization Configuration: 646.

     Force the stdout and stderr streams to be unbuffered.

     Set by the *note -u: 1d75. option and the *note PYTHONUNBUFFERED:
     1d76. environment variable.

     Deprecated since version 3.12, will be removed in version 3.15.

 -- C Variabile: int Py_VerboseFlag

     This API is kept for backward compatibility: setting *note
     PyConfig.verbose: 3fb. should be used instead, see *note Python
     Initialization Configuration: 646.

     Print a message each time a module is initialized, showing the
     place (filename or built-in module) from which it is loaded.  If
     greater or equal to ‘2’, print a message for each file that is
     checked for when searching for a module.  Also provides information
     on module cleanup at exit.

     Set by the *note -v: 162c. option and the *note PYTHONVERBOSE:
     2111. environment variable.

     Deprecated since version 3.12, will be removed in version 3.15.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0529/

   (2) https://peps.python.org/pep-0528/


File: python.info,  Node: Initializing and finalizing the interpreter,  Next: Process-wide parameters,  Prev: Global configuration variables,  Up: Initialization Finalization and Threads

7.10.3 Initializing and finalizing the interpreter
--------------------------------------------------

 -- C Funzione: void Py_Initialize ()
     ' Parte del *note ABI Stabile: 776.'

     Initialize the Python interpreter.  In an application embedding
     Python, this should be called before using any other Python/C API
     functions; see *note Before Python Initialization: dc0. for the few
     exceptions.

     This initializes the table of loaded modules (‘sys.modules’), and
     creates the fundamental modules *note builtins: 13, *note __main__:
     1. and *note sys: df.  It also initializes the module search path
     (‘sys.path’).  It does not set ‘sys.argv’; use the *note Python
     Initialization Configuration: 646. API for that.  This is a no-op
     when called for a second time (without calling *note
     Py_FinalizeEx(): f13. first).  There is no return value; it is a
     fatal error if the initialization fails.

     Use *note Py_InitializeFromConfig(): 3f6. to customize the *note
     Python Initialization Configuration: 646.

          Nota: On Windows, changes the console mode from ‘O_TEXT’ to
          ‘O_BINARY’, which will also affect non-Python uses of the
          console using the C Runtime.

 -- C Funzione: void Py_InitializeEx (int initsigs)
     ' Parte del *note ABI Stabile: 776.'  This function works like
     *note Py_Initialize(): 460. if 'initsigs' is ‘1’.  If 'initsigs' is
     ‘0’, it skips initialization registration of signal handlers, which
     may be useful when CPython is embedded as part of a larger
     application.

     Use *note Py_InitializeFromConfig(): 3f6. to customize the *note
     Python Initialization Configuration: 646.

 -- C Funzione: *note PyStatus: ba6. Py_InitializeFromConfig (const
          PyConfig *config)

     Initialize Python from 'config' configuration, as described in
     *note Initialization with PyConfig: 54f1.

     See the *note Python Initialization Configuration: 646. section for
     details on pre-initializing the interpreter, populating the runtime
     configuration structure, and querying the returned status
     structure.

 -- C Funzione: int Py_IsInitialized ()
     ' Parte del *note ABI Stabile: 776.'  Return true (nonzero) when
     the Python interpreter has been initialized, false (zero) if not.
     After *note Py_FinalizeEx(): f13. is called, this returns false
     until *note Py_Initialize(): 460. is called again.

 -- C Funzione: int Py_IsFinalizing ()
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Return
     true (non-zero) if the main Python interpreter is *note shutting
     down: 47a.  Return false (zero) otherwise.

     Added in version 3.13.

 -- C Funzione: int Py_FinalizeEx ()
     ' Parte del *note ABI Stabile: 776. dalla versione 3.6.'  Undo all
     initializations made by *note Py_Initialize(): 460. and subsequent
     use of Python/C API functions, and destroy all sub-interpreters
     (see *note Py_NewInterpreter(): 1b19. below) that were created and
     not yet destroyed since the last call to *note Py_Initialize():
     460.  This is a no-op when called for a second time (without
     calling *note Py_Initialize(): 460. again first).

     Since this is the reverse of *note Py_Initialize(): 460, it should
     be called in the same thread with the same interpreter active.
     That means the main thread and the main interpreter.  This should
     never be called while *note Py_RunMain(): bbe. is running.

     Normally the return value is ‘0’.  If there were errors during
     finalization (flushing buffered data), ‘-1’ is returned.

     Note that Python will do a best effort at freeing all memory
     allocated by the Python interpreter.  Therefore, any C-Extension
     should make sure to correctly clean up all of the preveiously
     allocated PyObjects before using them in subsequent calls to *note
     Py_Initialize(): 460.  Otherwise it could introduce vulnerabilities
     and incorrect behavior.

     This function is provided for a number of reasons.  An embedding
     application might want to restart Python without having to restart
     the application itself.  An application that has loaded the Python
     interpreter from a dynamically loadable library (or DLL) might want
     to free all memory allocated by Python before unloading the DLL.
     During a hunt for memory leaks in an application a developer might
     want to free all memory allocated by Python before exiting from the
     application.

     'Bugs and caveats:' The destruction of modules and objects in
     modules is done in random order; this may cause destructors (*note
     __del__(): 11ff. methods) to fail when they depend on other objects
     (even functions) or modules.  Dynamically loaded extension modules
     loaded by Python are not unloaded.  Small amounts of memory
     allocated by the Python interpreter may not be freed (if you find a
     leak, please report it).  Memory tied up in circular references
     between objects is not freed.  Interned strings will all be
     deallocated regardless of their reference count.  Some memory
     allocated by extension modules may not be freed.  Some extensions
     may not work properly if their initialization routine is called
     more than once; this can happen if an application calls *note
     Py_Initialize(): 460. and *note Py_FinalizeEx(): f13. more than
     once.  *note Py_FinalizeEx(): f13. must not be called recursively
     from within itself.  Therefore, it must not be called by any code
     that may be run as part of the interpreter shutdown process, such
     as *note atexit: d. handlers, object finalizers, or any code that
     may be run while flushing the stdout and stderr files.

     Raises an *note auditing event: 1c56.
     ‘cpython._PySys_ClearAuditHooks’ with no arguments.

     Added in version 3.6.

 -- C Funzione: void Py_Finalize ()
     ' Parte del *note ABI Stabile: 776.'  This is a
     backwards-compatible version of *note Py_FinalizeEx(): f13. that
     disregards the return value.

 -- C Funzione: int Py_BytesMain (int argc, char **argv)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.8.'  Similar
     to *note Py_Main(): e20. but 'argv' is an array of bytes strings,
     allowing the calling application to delegate the text decoding step
     to the CPython runtime.

     Added in version 3.8.

 -- C Funzione: int Py_Main (int argc, wchar_t **argv)
     ' Parte del *note ABI Stabile: 776.'  The main program for the
     standard interpreter, encapsulating a full
     initialization/finalization cycle, as well as additional behaviour
     to implement reading configurations settings from the environment
     and command line, and then executing ‘__main__’ in accordance with
     *note Command line: 1209.

     This is made available for programs which wish to support the full
     CPython command line interface, rather than just embedding a Python
     runtime in a larger application.

     The 'argc' and 'argv' parameters are similar to those which are
     passed to a C program’s ‘main()’ function, except that the 'argv'
     entries are first converted to ‘wchar_t’ using *note
     Py_DecodeLocale(): dc2.  It is also important to note that the
     argument list entries may be modified to point to strings other
     than those passed in (however, the contents of the strings pointed
     to by the argument list are not modified).

     The return value is ‘2’ if the argument list does not represent a
     valid Python command line, and otherwise the same as *note
     Py_RunMain(): bbe.

     In terms of the CPython runtime configuration APIs documented in
     the *note runtime configuration: 646. section (and without
     accounting for error handling), ‘Py_Main’ is approximately
     equivalent to:

          PyConfig config;
          PyConfig_InitPythonConfig(&config);
          PyConfig_SetArgv(&config, argc, argv);
          Py_InitializeFromConfig(&config);
          PyConfig_Clear(&config);

          Py_RunMain();

     In normal usage, an embedding application will call this function
     'instead' of calling *note Py_Initialize(): 460, *note
     Py_InitializeEx(): 510b. or *note Py_InitializeFromConfig(): 3f6.
     directly, and all settings will be applied as described elsewhere
     in this documentation.  If this function is instead called 'after'
     a preceding runtime initialization API call, then exactly which
     environmental and command line configuration settings will be
     updated is version dependent (as it depends on which settings
     correctly support being modified after they have already been set
     once when the runtime was first initialized).

 -- C Funzione: int Py_RunMain (void)

     Executes the main module in a fully configured CPython runtime.

     Executes the command (*note PyConfig.run_command: 54f2.), the
     script (*note PyConfig.run_filename: 54f3.) or the module (*note
     PyConfig.run_module: 54f4.) specified on the command line or in the
     configuration.  If none of these values are set, runs the
     interactive Python prompt (REPL) using the ‘__main__’ module’s
     global namespace.

     If *note PyConfig.inspect: 401. is not set (the default), the
     return value will be ‘0’ if the interpreter exits normally (that
     is, without raising an exception), the exit status of an unhandled
     *note SystemExit: f3e, or ‘1’ for any other unhandled exception.

     If *note PyConfig.inspect: 401. is set (such as when the *note -i:
     16e2. option is used), rather than returning when the interpreter
     exits, execution will instead resume in an interactive Python
     prompt (REPL) using the ‘__main__’ module’s global namespace.  If
     the interpreter exited with an exception, it is immediately raised
     in the REPL session.  The function return value is then determined
     by the way the 'REPL session' terminates: ‘0’, ‘1’, or the status
     of a *note SystemExit: f3e, as specified above.

     This function always finalizes the Python interpreter before it
     returns.

     See *note Python Configuration: 54f5. for an example of a
     customized Python that always runs in isolated mode using *note
     Py_RunMain(): bbe.

 -- C Funzione: int PyUnstable_AtExit (PyInterpreterState *interp, void
          (*func)(void*), void *data)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Register an *note atexit: d. callback for the target interpreter
     'interp'.  This is similar to *note Py_AtExit(): 5100, but takes an
     explicit interpreter and data pointer for the callback.

     There must be an *note attached thread state: 4eba. for 'interp'.

     Added in version 3.13.


File: python.info,  Node: Process-wide parameters,  Next: Thread State and the Global Interpreter Lock,  Prev: Initializing and finalizing the interpreter,  Up: Initialization Finalization and Threads

7.10.4 Process-wide parameters
------------------------------

 -- C Funzione: void Py_SetProgramName (const wchar_t *name)
     ' Parte del *note ABI Stabile: 776.'

     This API is kept for backward compatibility: setting *note
     PyConfig.program_name: 3f2. should be used instead, see *note
     Python Initialization Configuration: 646.

     This function should be called before *note Py_Initialize(): 460.
     is called for the first time, if it is called at all.  It tells the
     interpreter the value of the ‘argv[0]’ argument to the ‘main()’
     function of the program (converted to wide characters).  This is
     used by *note Py_GetPath(): 3e3. and some other functions below to
     find the Python run-time libraries relative to the interpreter
     executable.  The default value is ‘'python'’.  The argument should
     point to a zero-terminated wide character string in static storage
     whose contents will not change for the duration of the program’s
     execution.  No code in the Python interpreter will change the
     contents of this storage.

     Use *note Py_DecodeLocale(): dc2. to decode a bytes string to get a
     wchar_t* string.

     Deprecated since version 3.11, will be removed in version 3.15.

 -- C Funzione: wchar_t *Py_GetProgramName ()
     ' Parte del *note ABI Stabile: 776.'  Return the program name set
     with *note PyConfig.program_name: 3f2, or the default.  The
     returned string points into static storage; the caller should not
     modify its value.

     This function should not be called before *note Py_Initialize():
     460, otherwise it returns ‘NULL’.

     Cambiato nella versione 3.10: It now returns ‘NULL’ if called
     before *note Py_Initialize(): 460.

     Deprecated since version 3.13, will be removed in version 3.15: Use
     *note PyConfig_Get("executable"): 37c. (*note sys.executable: 3ed.)
     instead.

 -- C Funzione: wchar_t *Py_GetPrefix ()
     ' Parte del *note ABI Stabile: 776.'  Return the 'prefix' for
     installed platform-independent files.  This is derived through a
     number of complicated rules from the program name set with *note
     PyConfig.program_name: 3f2. and some environment variables; for
     example, if the program name is ‘'/usr/local/bin/python'’, the
     prefix is ‘'/usr/local'’.  The returned string points into static
     storage; the caller should not modify its value.  This corresponds
     to the ‘prefix’ variable in the top-level ‘Makefile’ and the *note
     -prefix: 2138. argument to the ‘configure’ script at build time.
     The value is available to Python code as ‘sys.base_prefix’.  It is
     only useful on Unix.  See also the next function.

     This function should not be called before *note Py_Initialize():
     460, otherwise it returns ‘NULL’.

     Cambiato nella versione 3.10: It now returns ‘NULL’ if called
     before *note Py_Initialize(): 460.

     Deprecated since version 3.13, will be removed in version 3.15: Use
     *note PyConfig_Get("base_prefix"): 37c. (*note sys.base_prefix:
     3e6.) instead.  Use *note PyConfig_Get("prefix"): 37c. (*note
     sys.prefix: 3e7.) if *note virtual environments: 3e8. need to be
     handled.

 -- C Funzione: wchar_t *Py_GetExecPrefix ()
     ' Parte del *note ABI Stabile: 776.'  Return the 'exec-prefix' for
     installed platform-'dependent' files.  This is derived through a
     number of complicated rules from the program name set with *note
     PyConfig.program_name: 3f2. and some environment variables; for
     example, if the program name is ‘'/usr/local/bin/python'’, the
     exec-prefix is ‘'/usr/local'’.  The returned string points into
     static storage; the caller should not modify its value.  This
     corresponds to the ‘exec_prefix’ variable in the top-level
     ‘Makefile’ and the ‘--exec-prefix’ argument to the ‘configure’
     script at build time.  The value is available to Python code as
     ‘sys.base_exec_prefix’.  It is only useful on Unix.

     Background: The exec-prefix differs from the prefix when platform
     dependent files (such as executables and shared libraries) are
     installed in a different directory tree.  In a typical
     installation, platform dependent files may be installed in the
     ‘/usr/local/plat’ subtree while platform independent may be
     installed in ‘/usr/local’.

     Generally speaking, a platform is a combination of hardware and
     software families, e.g.  Sparc machines running the Solaris 2.x
     operating system are considered the same platform, but Intel
     machines running Solaris 2.x are another platform, and Intel
     machines running Linux are yet another platform.  Different major
     revisions of the same operating system generally also form
     different platforms.  Non-Unix operating systems are a different
     story; the installation strategies on those systems are so
     different that the prefix and exec-prefix are meaningless, and set
     to the empty string.  Note that compiled Python bytecode files are
     platform independent (but not independent from the Python version
     by which they were compiled!).

     System administrators will know how to configure the ‘mount’ or
     ‘automount’ programs to share ‘/usr/local’ between platforms while
     having ‘/usr/local/plat’ be a different filesystem for each
     platform.

     This function should not be called before *note Py_Initialize():
     460, otherwise it returns ‘NULL’.

     Cambiato nella versione 3.10: It now returns ‘NULL’ if called
     before *note Py_Initialize(): 460.

     Deprecated since version 3.13, will be removed in version 3.15: Use
     *note PyConfig_Get("base_exec_prefix"): 37c. (*note
     sys.base_exec_prefix: 3ea.) instead.  Use *note
     PyConfig_Get("exec_prefix"): 37c. (*note sys.exec_prefix: 3eb.) if
     *note virtual environments: 3e8. need to be handled.

 -- C Funzione: wchar_t *Py_GetProgramFullPath ()
     ' Parte del *note ABI Stabile: 776.'

     Return the full program name of the Python executable; this is
     computed as a side-effect of deriving the default module search
     path from the program name (set by *note PyConfig.program_name:
     3f2.).  The returned string points into static storage; the caller
     should not modify its value.  The value is available to Python code
     as ‘sys.executable’.

     This function should not be called before *note Py_Initialize():
     460, otherwise it returns ‘NULL’.

     Cambiato nella versione 3.10: It now returns ‘NULL’ if called
     before *note Py_Initialize(): 460.

     Deprecated since version 3.13, will be removed in version 3.15: Use
     *note PyConfig_Get("executable"): 37c. (*note sys.executable: 3ed.)
     instead.

 -- C Funzione: wchar_t *Py_GetPath ()
     ' Parte del *note ABI Stabile: 776.'

     Return the default module search path; this is computed from the
     program name (set by *note PyConfig.program_name: 3f2.) and some
     environment variables.  The returned string consists of a series of
     directory names separated by a platform dependent delimiter
     character.  The delimiter character is ‘':'’ on Unix and macOS,
     ‘';'’ on Windows.  The returned string points into static storage;
     the caller should not modify its value.  The list *note sys.path:
     3e4. is initialized with this value on interpreter startup; it can
     be (and usually is) modified later to change the search path for
     loading modules.

     This function should not be called before *note Py_Initialize():
     460, otherwise it returns ‘NULL’.

     Cambiato nella versione 3.10: It now returns ‘NULL’ if called
     before *note Py_Initialize(): 460.

     Deprecated since version 3.13, will be removed in version 3.15: Use
     *note PyConfig_Get("module_search_paths"): 37c. (*note sys.path:
     3e4.) instead.

 -- C Funzione: const char *Py_GetVersion ()
     ' Parte del *note ABI Stabile: 776.'  Return the version of this
     Python interpreter.  This is a string that looks something like

          "3.0a5+ (py3k:63103M, May 12 2008, 00:53:55) \n[GCC 4.2.3]"

     The first word (up to the first space character) is the current
     Python version; the first characters are the major and minor
     version separated by a period.  The returned string points into
     static storage; the caller should not modify its value.  The value
     is available to Python code as *note sys.version: 49d.

     See also the *note Py_Version: 381. constant.

 -- C Funzione: const char *Py_GetPlatform ()
     ' Parte del *note ABI Stabile: 776.'

     Return the platform identifier for the current platform.  On Unix,
     this is formed from the «official» name of the operating system,
     converted to lower case, followed by the major revision number;
     e.g., for Solaris 2.x, which is also known as SunOS 5.x, the value
     is ‘'sunos5'’.  On macOS, it is ‘'darwin'’.  On Windows, it is
     ‘'win'’.  The returned string points into static storage; the
     caller should not modify its value.  The value is available to
     Python code as ‘sys.platform’.

 -- C Funzione: const char *Py_GetCopyright ()
     ' Parte del *note ABI Stabile: 776.'  Return the official copyright
     string for the current Python version, for example

     ‘'Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam'’

     The returned string points into static storage; the caller should
     not modify its value.  The value is available to Python code as
     ‘sys.copyright’.

 -- C Funzione: const char *Py_GetCompiler ()
     ' Parte del *note ABI Stabile: 776.'  Return an indication of the
     compiler used to build the current Python version, in square
     brackets, for example:

          "[GCC 2.7.2.2]"

     The returned string points into static storage; the caller should
     not modify its value.  The value is available to Python code as
     part of the variable ‘sys.version’.

 -- C Funzione: const char *Py_GetBuildInfo ()
     ' Parte del *note ABI Stabile: 776.'  Return information about the
     sequence number and build date and time of the current Python
     interpreter instance, for example

          "#67, Aug  1 1997, 22:34:28"

     The returned string points into static storage; the caller should
     not modify its value.  The value is available to Python code as
     part of the variable ‘sys.version’.

 -- C Funzione: void PySys_SetArgvEx (int argc, wchar_t **argv, int
          updatepath)
     ' Parte del *note ABI Stabile: 776.'

     This API is kept for backward compatibility: setting *note
     PyConfig.argv: 3f1, *note PyConfig.parse_argv: 1cd9. and *note
     PyConfig.safe_path: 978. should be used instead, see *note Python
     Initialization Configuration: 646.

     Set *note sys.argv: 146c. based on 'argc' and 'argv'.  These
     parameters are similar to those passed to the program’s ‘main()’
     function with the difference that the first entry should refer to
     the script file to be executed rather than the executable hosting
     the Python interpreter.  If there isn’t a script that will be run,
     the first entry in 'argv' can be an empty string.  If this function
     fails to initialize *note sys.argv: 146c, a fatal condition is
     signalled using *note Py_FatalError(): b7c.

     If 'updatepath' is zero, this is all the function does.  If
     'updatepath' is non-zero, the function also modifies *note
     sys.path: 3e4. according to the following algorithm:

        - If the name of an existing script is passed in ‘argv[0]’, the
          absolute path of the directory where the script is located is
          prepended to *note sys.path: 3e4.

        - Otherwise (that is, if 'argc' is ‘0’ or ‘argv[0]’ doesn’t
          point to an existing file name), an empty string is prepended
          to *note sys.path: 3e4, which is the same as prepending the
          current working directory (‘"."’).

     Use *note Py_DecodeLocale(): dc2. to decode a bytes string to get a
     wchar_t* string.

     See also *note PyConfig.orig_argv: a96. and *note PyConfig.argv:
     3f1. members of the *note Python Initialization Configuration: 646.

          Nota: It is recommended that applications embedding the Python
          interpreter for purposes other than executing a single script
          pass ‘0’ as 'updatepath', and update *note sys.path: 3e4.
          themselves if desired.  See CVE 2008-5983(1).

          On versions before 3.1.3, you can achieve the same effect by
          manually popping the first *note sys.path: 3e4. element after
          having called *note PySys_SetArgv(): 19a0, for example using:

               PyRun_SimpleString("import sys; sys.path.pop(0)\n");

     Added in version 3.1.3.

     Deprecated since version 3.11, will be removed in version 3.15.

 -- C Funzione: void PySys_SetArgv (int argc, wchar_t **argv)
     ' Parte del *note ABI Stabile: 776.'  This API is kept for backward
     compatibility: setting *note PyConfig.argv: 3f1. and *note
     PyConfig.parse_argv: 1cd9. should be used instead, see *note Python
     Initialization Configuration: 646.

     This function works like *note PySys_SetArgvEx(): 199f. with
     'updatepath' set to ‘1’ unless the ‘python’ interpreter was started
     with the *note -I: b59.

     Use *note Py_DecodeLocale(): dc2. to decode a bytes string to get a
     wchar_t* string.

     See also *note PyConfig.orig_argv: a96. and *note PyConfig.argv:
     3f1. members of the *note Python Initialization Configuration: 646.

     Cambiato nella versione 3.4: The 'updatepath' value depends on
     *note -I: b59.

     Deprecated since version 3.11, will be removed in version 3.15.

 -- C Funzione: void Py_SetPythonHome (const wchar_t *home)
     ' Parte del *note ABI Stabile: 776.'  This API is kept for backward
     compatibility: setting *note PyConfig.home: 3f3. should be used
     instead, see *note Python Initialization Configuration: 646.

     Set the default «home» directory, that is, the location of the
     standard Python libraries.  See *note PYTHONHOME: 3f0. for the
     meaning of the argument string.

     The argument should point to a zero-terminated character string in
     static storage whose contents will not change for the duration of
     the program’s execution.  No code in the Python interpreter will
     change the contents of this storage.

     Use *note Py_DecodeLocale(): dc2. to decode a bytes string to get a
     wchar_t* string.

     Deprecated since version 3.11, will be removed in version 3.15.

 -- C Funzione: wchar_t *Py_GetPythonHome ()
     ' Parte del *note ABI Stabile: 776.'  Return the default «home»,
     that is, the value set by *note PyConfig.home: 3f3, or the value of
     the *note PYTHONHOME: 3f0. environment variable if it is set.

     This function should not be called before *note Py_Initialize():
     460, otherwise it returns ‘NULL’.

     Cambiato nella versione 3.10: It now returns ‘NULL’ if called
     before *note Py_Initialize(): 460.

     Deprecated since version 3.13, will be removed in version 3.15: Use
     *note PyConfig_Get("home"): 37c. or the *note PYTHONHOME: 3f0.
     environment variable instead.

   ---------- Footnotes ----------

   (1) https://www.cve.org/CVERecord?id=CVE-2008-5983


File: python.info,  Node: Thread State and the Global Interpreter Lock,  Next: Sub-interpreter support,  Prev: Process-wide parameters,  Up: Initialization Finalization and Threads

7.10.5 Thread State and the Global Interpreter Lock
---------------------------------------------------

Unless on a *note free-threaded: 1f4. build of *note CPython: 906, the
Python interpreter is not fully thread-safe.  In order to support
multi-threaded Python programs, there’s a global lock, called the *note
global interpreter lock: 474. or *note GIL: 164, that must be held by
the current thread before it can safely access Python objects.  Without
the lock, even the simplest operations could cause problems in a
multi-threaded program: for example, when two threads simultaneously
increment the reference count of the same object, the reference count
could end up being incremented only once instead of twice.

Therefore, the rule exists that only the thread that has acquired the
*note GIL: 164. may operate on Python objects or call Python/C API
functions.  In order to emulate concurrency of execution, the
interpreter regularly tries to switch threads (see *note
sys.setswitchinterval(): b46.).  The lock is also released around
potentially blocking I/O operations like reading or writing a file, so
that other Python threads can run in the meantime.

The Python interpreter keeps some thread-specific bookkeeping
information inside a data structure called *note PyThreadState: 991,
known as a *note thread state: 182e.  Each OS thread has a thread-local
pointer to a *note PyThreadState: 991.; a thread state referenced by
this pointer is considered to be *note attached: 4eba.

A thread can only have one *note attached thread state: 4eba. at a time.
An attached thread state is typically analogous with holding the *note
GIL: 164, except on *note free-threaded: 1f4. builds.  On builds with
the *note GIL: 164. enabled, *note attaching: 4eba. a thread state will
block until the *note GIL: 164. can be acquired.  However, even on
builds with the *note GIL: 164. disabled, it is still required to have
an attached thread state to call most of the C API.

In general, there will always be an *note attached thread state: 4eba.
when using Python’s C API. Only in some specific cases (such as in a
*note Py_BEGIN_ALLOW_THREADS: 4ea6. block) will the thread not have an
attached thread state.  If uncertain, check if *note
PyThreadState_GetUnchecked(): 423. returns ‘NULL’.

* Menu:

* Detaching the thread state from extension code::
* Non-Python created threads::
* Supporting subinterpreters in non-Python threads::
* Cautions about fork(): Cautions about fork.
* Cautions regarding runtime finalization::
* High-level API::
* Low-level API::


File: python.info,  Node: Detaching the thread state from extension code,  Next: Non-Python created threads,  Up: Thread State and the Global Interpreter Lock

7.10.5.1 Detaching the thread state from extension code
.......................................................

Most extension code manipulating the *note thread state: 182e. has the
following simple structure:

     Save the thread state in a local variable.
     ... Do some blocking I/O operation ...
     Restore the thread state from the local variable.

This is so common that a pair of macros exists to simplify it:

     Py_BEGIN_ALLOW_THREADS
     ... Do some blocking I/O operation ...
     Py_END_ALLOW_THREADS

The *note Py_BEGIN_ALLOW_THREADS: 4ea6. macro opens a new block and
declares a hidden local variable; the *note Py_END_ALLOW_THREADS: c81.
macro closes the block.

The block above expands to the following code:

     PyThreadState *_save;

     _save = PyEval_SaveThread();
     ... Do some blocking I/O operation ...
     PyEval_RestoreThread(_save);

Here is how these functions work:

The *note attached thread state: 4eba. holds the *note GIL: 164. for the
entire interpreter.  When detaching the *note attached thread state:
4eba, the *note GIL: 164. is released, allowing other threads to attach
a thread state to their own thread, thus getting the *note GIL: 164. and
can start executing.  The pointer to the prior *note attached thread
state: 4eba. is stored as a local variable.  Upon reaching *note
Py_END_ALLOW_THREADS: c81, the thread state that was previously *note
attached: 4eba. is passed to *note PyEval_RestoreThread(): 648.  This
function will block until another releases its *note thread state: 4eba,
thus allowing the old *note thread state: 4eba. to get re-attached and
the C API can be called again.

For *note free-threaded: 1f4. builds, the *note GIL: 164. is normally
out of the question, but detaching the *note thread state: 4eba. is
still required for blocking I/O and long operations.  The difference is
that threads don’t have to wait for the *note GIL: 164. to be released
to attach their thread state, allowing true multi-core parallelism.

     Nota: Calling system I/O functions is the most common use case for
     detaching the *note thread state: 4eba, but it can also be useful
     before calling long-running computations which don’t need access to
     Python objects, such as compression or cryptographic functions
     operating over memory buffers.  For example, the standard *note
     zlib: 139. and *note hashlib: 6c. modules detach the *note thread
     state: 4eba. when compressing or hashing data.


File: python.info,  Node: Non-Python created threads,  Next: Supporting subinterpreters in non-Python threads,  Prev: Detaching the thread state from extension code,  Up: Thread State and the Global Interpreter Lock

7.10.5.2 Non-Python created threads
...................................

When threads are created using the dedicated Python APIs (such as the
*note threading: f3. module), a thread state is automatically associated
to them and the code showed above is therefore correct.  However, when
threads are created from C (for example by a third-party library with
its own thread management), they don’t hold the *note GIL: 164, because
they don’t have an *note attached thread state: 4eba.

If you need to call Python code from these threads (often this will be
part of a callback API provided by the aforementioned third-party
library), you must first register these threads with the interpreter by
creating an *note attached thread state: 4eba. before you can start
using the Python/C API. When you are done, you should detach the *note
thread state: 4eba, and finally free it.

The *note PyGILState_Ensure(): 64a. and *note PyGILState_Release(): 64b.
functions do all of the above automatically.  The typical idiom for
calling into Python from a C thread is:

     PyGILState_STATE gstate;
     gstate = PyGILState_Ensure();

     /* Perform Python actions here. */
     result = CallSomeFunction();
     /* evaluate result or handle exception */

     /* Release the thread. No Python API allowed beyond this point. */
     PyGILState_Release(gstate);

Note that the ‘PyGILState_*’ functions assume there is only one global
interpreter (created automatically by *note Py_Initialize(): 460.).
Python supports the creation of additional interpreters (using *note
Py_NewInterpreter(): 1b19.), but mixing multiple interpreters and the
‘PyGILState_*’ API is unsupported.  This is because *note
PyGILState_Ensure(): 64a. and similar functions default to *note
attaching: 4eba. a *note thread state: 182e. for the main interpreter,
meaning that the thread can’t safely interact with the calling
subinterpreter.


File: python.info,  Node: Supporting subinterpreters in non-Python threads,  Next: Cautions about fork,  Prev: Non-Python created threads,  Up: Thread State and the Global Interpreter Lock

7.10.5.3 Supporting subinterpreters in non-Python threads
.........................................................

If you would like to support subinterpreters with non-Python created
threads, you must use the ‘PyThreadState_*’ API instead of the
traditional ‘PyGILState_*’ API.

In particular, you must store the interpreter state from the calling
function and pass it to *note PyThreadState_New(): 509b, which will
ensure that the *note thread state: 182e. is targeting the correct
interpreter:

     /* The return value of PyInterpreterState_Get() from the
        function that created this thread. */
     PyInterpreterState *interp = ThreadData->interp;
     PyThreadState *tstate = PyThreadState_New(interp);
     PyThreadState_Swap(tstate);

     /* GIL of the subinterpreter is now held.
        Perform Python actions here. */
     result = CallSomeFunction();
     /* evaluate result or handle exception */

     /* Destroy the thread state. No Python API allowed beyond this point. */
     PyThreadState_Clear(tstate);
     PyThreadState_DeleteCurrent();


File: python.info,  Node: Cautions about fork,  Next: Cautions regarding runtime finalization,  Prev: Supporting subinterpreters in non-Python threads,  Up: Thread State and the Global Interpreter Lock

7.10.5.4 Cautions about fork()
..............................

Another important thing to note about threads is their behaviour in the
face of the C ‘fork()’ call.  On most systems with ‘fork()’, after a
process forks only the thread that issued the fork will exist.  This has
a concrete impact both on how locks must be handled and on all stored
state in CPython’s runtime.

The fact that only the «current» thread remains means any locks held by
other threads will never be released.  Python solves this for *note
os.fork(): 4b6. by acquiring the locks it uses internally before the
fork, and releasing them afterwards.  In addition, it resets any *note
Lock objects: 3609. in the child.  When extending or embedding Python,
there is no way to inform Python of additional (non-Python) locks that
need to be acquired before or reset after a fork.  OS facilities such as
‘pthread_atfork()’ would need to be used to accomplish the same thing.
Additionally, when extending or embedding Python, calling ‘fork()’
directly rather than through *note os.fork(): 4b6. (and returning to or
calling into Python) may result in a deadlock by one of Python’s
internal locks being held by a thread that is defunct after the fork.
*note PyOS_AfterFork_Child(): 430. tries to reset the necessary locks,
but is not always able to.

The fact that all other threads go away also means that CPython’s
runtime state there must be cleaned up properly, which *note os.fork():
4b6. does.  This means finalizing all other *note PyThreadState: 991.
objects belonging to the current interpreter and all other *note
PyInterpreterState: abc. objects.  Due to this and the special nature of
the *note «main» interpreter: 163, ‘fork()’ should only be called in
that interpreter’s «main» thread, where the CPython global runtime was
originally initialized.  The only exception is if ‘exec()’ will be
called immediately after.


File: python.info,  Node: Cautions regarding runtime finalization,  Next: High-level API,  Prev: Cautions about fork,  Up: Thread State and the Global Interpreter Lock

7.10.5.5 Cautions regarding runtime finalization
................................................

In the late stage of *note interpreter shutdown: 47a, after attempting
to wait for non-daemon threads to exit (though this can be interrupted
by *note KeyboardInterrupt: bc7.) and running the *note atexit: d.
functions, the runtime is marked as 'finalizing': *note
Py_IsFinalizing(): 5fd. and *note sys.is_finalizing(): c82. return true.
At this point, only the 'finalization thread' that initiated
finalization (typically the main thread) is allowed to acquire the *note
GIL: 164.

If any thread, other than the finalization thread, attempts to attach a
*note thread state: 182e. during finalization, either explicitly or
implicitly, the thread enters 'a permanently blocked state' where it
remains until the program exits.  In most cases this is harmless, but
this can result in deadlock if a later stage of finalization attempts to
acquire a lock owned by the blocked thread, or otherwise waits on the
blocked thread.

Gross?  Yes.  This prevents random crashes and/or unexpectedly skipped
C++ finalizations further up the call stack when such threads were
forcibly exited here in CPython 3.13 and earlier.  The CPython runtime
*note thread state: 182e. C APIs have never had any error reporting or
handling expectations at *note thread state: 182e. attachment time that
would’ve allowed for graceful exit from this situation.  Changing that
would require new stable C APIs and rewriting the majority of C code in
the CPython ecosystem to use those with error handling.


File: python.info,  Node: High-level API,  Next: Low-level API,  Prev: Cautions regarding runtime finalization,  Up: Thread State and the Global Interpreter Lock

7.10.5.6 High-level API
.......................

These are the most commonly used types and functions when writing C
extension code, or when embedding the Python interpreter:

 -- C Tipo: type PyInterpreterState
     ' Parte del *note API Limitata: 776. (come una struttura opaca).'
     This data structure represents the state shared by a number of
     cooperating threads.  Threads belonging to the same interpreter
     share their module administration and a few other internal items.
     There are no public members in this structure.

     Threads belonging to different interpreters initially share
     nothing, except process state like available memory, open file
     descriptors and such.  The global interpreter lock is also shared
     by all threads, regardless of to which interpreter they belong.

     Cambiato nella versione 3.12: PEP 684(1) introduced the possibility
     of a *note per-interpreter GIL: 5501.  See *note
     Py_NewInterpreterFromConfig(): 68a.

 -- C Tipo: type PyThreadState
     ' Parte del *note API Limitata: 776. (come una struttura opaca).'
     This data structure represents the state of a single thread.  The
     only public data member is:

      -- C Membro: *note PyInterpreterState: abc. *interp

          This thread’s interpreter state.

 -- C Funzione: void PyEval_InitThreads ()
     ' Parte del *note ABI Stabile: 776.'

     Deprecated function which does nothing.

     In Python 3.6 and older, this function created the GIL if it didn’t
     exist.

     Cambiato nella versione 3.9: The function now does nothing.

     Cambiato nella versione 3.7: This function is now called by *note
     Py_Initialize(): 460, so you don’t have to call it yourself
     anymore.

     Cambiato nella versione 3.2: This function cannot be called before
     *note Py_Initialize(): 460. anymore.

     Deprecato dalla versione 3.9.

 -- C Funzione: *note PyThreadState: 991. *PyEval_SaveThread ()
     ' Parte del *note ABI Stabile: 776.'  Detach the *note attached
     thread state: 4eba. and return it.  The thread will have no *note
     thread state: 182e. upon returning.

 -- C Funzione: void PyEval_RestoreThread (PyThreadState *tstate)
     ' Parte del *note ABI Stabile: 776.'  Set the *note attached thread
     state: 4eba. to 'tstate'.  The passed *note thread state: 182e.
     'should not' be *note attached: 4eba, otherwise deadlock ensues.
     'tstate' will be attached upon returning.

          Nota: Calling this function from a thread when the runtime is
          finalizing will hang the thread until the program exits, even
          if the thread was not created by Python.  Refer to *note
          Cautions regarding runtime finalization: 54fe. for more
          details.

     Cambiato nella versione 3.14: Hangs the current thread, rather than
     terminating it, if called while the interpreter is finalizing.

 -- C Funzione: *note PyThreadState: 991. *PyThreadState_Get ()
     ' Parte del *note ABI Stabile: 776.'  Return the *note attached
     thread state: 4eba.  If the thread has no attached thread state,
     (such as when inside of *note Py_BEGIN_ALLOW_THREADS: 4ea6. block),
     then this issues a fatal error (so that the caller needn’t check
     for ‘NULL’).

     See also *note PyThreadState_GetUnchecked(): 423.

 -- C Funzione: *note PyThreadState: 991. *PyThreadState_GetUnchecked ()

     Similar to *note PyThreadState_Get(): 615, but don’t kill the
     process with a fatal error if it is NULL. The caller is responsible
     to check if the result is NULL.

     Added in version 3.13: In Python 3.5 to 3.12, the function was
     private and known as ‘_PyThreadState_UncheckedGet()’.

 -- C Funzione: *note PyThreadState: 991. *PyThreadState_Swap
          (PyThreadState *tstate)
     ' Parte del *note ABI Stabile: 776.'  Set the *note attached thread
     state: 4eba. to 'tstate', and return the *note thread state: 182e.
     that was attached prior to calling.

     This function is safe to call without an *note attached thread
     state: 4eba.; it will simply return ‘NULL’ indicating that there
     was no prior thread state.

     Vedi anche
     ..........

     *note PyEval_ReleaseThread(): 4fb6.

          Nota: Similar to *note PyGILState_Ensure(): 64a, this function
          will hang the thread if the runtime is finalizing.

The following functions use thread-local storage, and are not compatible
with sub-interpreters:

 -- C Tipo: type PyGILState_STATE
     ' Parte del *note ABI Stabile: 776.'  The type of the value
     returned by *note PyGILState_Ensure(): 64a. and passed to *note
     PyGILState_Release(): 64b.

      -- C Enumeratore: enumerator PyGILState_LOCKED

          The GIL was already held when *note PyGILState_Ensure(): 64a.
          was called.

      -- C Enumeratore: enumerator PyGILState_UNLOCKED

          The GIL was not held when *note PyGILState_Ensure(): 64a. was
          called.

 -- C Funzione: *note PyGILState_STATE: 5006. PyGILState_Ensure ()
     ' Parte del *note ABI Stabile: 776.'  Ensure that the current
     thread is ready to call the Python C API regardless of the current
     state of Python, or of the *note attached thread state: 4eba.  This
     may be called as many times as desired by a thread as long as each
     call is matched with a call to *note PyGILState_Release(): 64b.  In
     general, other thread-related APIs may be used between *note
     PyGILState_Ensure(): 64a. and *note PyGILState_Release(): 64b.
     calls as long as the thread state is restored to its previous state
     before the Release().  For example, normal usage of the *note
     Py_BEGIN_ALLOW_THREADS: 4ea6. and *note Py_END_ALLOW_THREADS: c81.
     macros is acceptable.

     The return value is an opaque «handle» to the *note attached thread
     state: 4eba. when *note PyGILState_Ensure(): 64a. was called, and
     must be passed to *note PyGILState_Release(): 64b. to ensure Python
     is left in the same state.  Even though recursive calls are
     allowed, these handles 'cannot' be shared - each unique call to
     *note PyGILState_Ensure(): 64a. must save the handle for its call
     to *note PyGILState_Release(): 64b.

     When the function returns, there will be an *note attached thread
     state: 4eba. and the thread will be able to call arbitrary Python
     code.  Failure is a fatal error.

          Avvertimento: Calling this function when the runtime is
          finalizing is unsafe.  Doing so will either hang the thread
          until the program ends, or fully crash the interpreter in rare
          cases.  Refer to *note Cautions regarding runtime
          finalization: 54fe. for more details.

     Cambiato nella versione 3.14: Hangs the current thread, rather than
     terminating it, if called while the interpreter is finalizing.

 -- C Funzione: void PyGILState_Release (PyGILState_STATE)
     ' Parte del *note ABI Stabile: 776.'  Release any resources
     previously acquired.  After this call, Python’s state will be the
     same as it was prior to the corresponding *note
     PyGILState_Ensure(): 64a. call (but generally this state will be
     unknown to the caller, hence the use of the GILState API).

     Every call to *note PyGILState_Ensure(): 64a. must be matched by a
     call to *note PyGILState_Release(): 64b. on the same thread.

 -- C Funzione: *note PyThreadState: 991. *PyGILState_GetThisThreadState
          ()
     ' Parte del *note ABI Stabile: 776.'  Get the *note attached thread
     state: 4eba. for this thread.  May return ‘NULL’ if no GILState API
     has been used on the current thread.  Note that the main thread
     always has such a thread-state, even if no auto-thread-state call
     has been made on the main thread.  This is mainly a
     helper/diagnostic function.

          Nota: This function may return non-‘NULL’ even when the *note
          thread state: 182e. is detached.  Prefer *note
          PyThreadState_Get(): 615. or *note
          PyThreadState_GetUnchecked(): 423. for most cases.

     Vedi anche
     ..........

     *note PyThreadState_Get(): 615.

 -- C Funzione: int PyGILState_Check ()

     Return ‘1’ if the current thread is holding the *note GIL: 164. and
     ‘0’ otherwise.  This function can be called from any thread at any
     time.  Only if it has had its *note thread state: 4eba. initialized
     via *note PyGILState_Ensure(): 64a. will it return ‘1’.  This is
     mainly a helper/diagnostic function.  It can be useful for example
     in callback contexts or memory allocation functions when knowing
     that the *note GIL: 164. is locked can allow the caller to perform
     sensitive actions or otherwise behave differently.

          Nota: If the current Python process has ever created a
          subinterpreter, this function will 'always' return ‘1’.
          Prefer *note PyThreadState_GetUnchecked(): 423. for most
          cases.

     Added in version 3.4.

The following macros are normally used without a trailing semicolon;
look for example usage in the Python source distribution.

 -- C Macro: Py_BEGIN_ALLOW_THREADS
     ' Parte del *note ABI Stabile: 776.'  This macro expands to ‘{
     PyThreadState *_save; _save = PyEval_SaveThread();’.  Note that it
     contains an opening brace; it must be matched with a following
     *note Py_END_ALLOW_THREADS: c81. macro.  See above for further
     discussion of this macro.

 -- C Macro: Py_END_ALLOW_THREADS
     ' Parte del *note ABI Stabile: 776.'  This macro expands to
     ‘PyEval_RestoreThread(_save); }’.  Note that it contains a closing
     brace; it must be matched with an earlier *note
     Py_BEGIN_ALLOW_THREADS: 4ea6. macro.  See above for further
     discussion of this macro.

 -- C Macro: Py_BLOCK_THREADS
     ' Parte del *note ABI Stabile: 776.'  This macro expands to
     ‘PyEval_RestoreThread(_save);’: it is equivalent to *note
     Py_END_ALLOW_THREADS: c81. without the closing brace.

 -- C Macro: Py_UNBLOCK_THREADS
     ' Parte del *note ABI Stabile: 776.'  This macro expands to ‘_save
     = PyEval_SaveThread();’: it is equivalent to *note
     Py_BEGIN_ALLOW_THREADS: 4ea6. without the opening brace and
     variable declaration.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0684/


File: python.info,  Node: Low-level API,  Prev: High-level API,  Up: Thread State and the Global Interpreter Lock

7.10.5.7 Low-level API
......................

All of the following functions must be called after *note
Py_Initialize(): 460.

Cambiato nella versione 3.7: *note Py_Initialize(): 460. now initializes
the *note GIL: 164. and sets an *note attached thread state: 4eba.

 -- C Funzione: *note PyInterpreterState: abc. *PyInterpreterState_New
          ()
     ' Parte del *note ABI Stabile: 776.'  Create a new interpreter
     state object.  An *note attached thread state: 4eba. is not needed,
     but may optionally exist if it is necessary to serialize calls to
     this function.

     Raises an *note auditing event: 1c56.
     ‘cpython.PyInterpreterState_New’ with no arguments.

 -- C Funzione: void PyInterpreterState_Clear (PyInterpreterState
          *interp)
     ' Parte del *note ABI Stabile: 776.'  Reset all information in an
     interpreter state object.  There must be an *note attached thread
     state: 4eba. for the interpreter.

     Raises an *note auditing event: 1c56.
     ‘cpython.PyInterpreterState_Clear’ with no arguments.

 -- C Funzione: void PyInterpreterState_Delete (PyInterpreterState
          *interp)
     ' Parte del *note ABI Stabile: 776.'  Destroy an interpreter state
     object.  There 'should not' be an *note attached thread state:
     4eba. for the target interpreter.  The interpreter state must have
     been reset with a previous call to *note
     PyInterpreterState_Clear(): 473b.

 -- C Funzione: *note PyThreadState: 991. *PyThreadState_New
          (PyInterpreterState *interp)
     ' Parte del *note ABI Stabile: 776.'  Create a new thread state
     object belonging to the given interpreter object.  An *note
     attached thread state: 4eba. is not needed.

 -- C Funzione: void PyThreadState_Clear (PyThreadState *tstate)
     ' Parte del *note ABI Stabile: 776.'  Reset all information in a
     *note thread state: 182e. object.  'tstate' must be *note attached:
     4eba.

     Cambiato nella versione 3.9: This function now calls the
     ‘PyThreadState.on_delete’ callback.  Previously, that happened in
     *note PyThreadState_Delete(): 1d71.

     Cambiato nella versione 3.13: The ‘PyThreadState.on_delete’
     callback was removed.

 -- C Funzione: void PyThreadState_Delete (PyThreadState *tstate)
     ' Parte del *note ABI Stabile: 776.'  Destroy a *note thread state:
     182e. object.  'tstate' should not be *note attached: 4eba. to any
     thread.  'tstate' must have been reset with a previous call to
     *note PyThreadState_Clear(): 1979.

 -- C Funzione: void PyThreadState_DeleteCurrent (void)

     Detach the *note attached thread state: 4eba. (which must have been
     reset with a previous call to *note PyThreadState_Clear(): 1979.)
     and then destroy it.

     No *note thread state: 182e. will be *note attached: 4eba. upon
     returning.

 -- C Funzione: *note PyFrameObject: 98d. *PyThreadState_GetFrame
          (PyThreadState *tstate)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Get the
     current frame of the Python thread state 'tstate'.

     Return a *note strong reference: 5e2.  Return ‘NULL’ if no frame is
     currently executing.

     See also *note PyEval_GetFrame(): 1b21.

     'tstate' must not be ‘NULL’, and must be *note attached: 4eba.

     Added in version 3.9.

 -- C Funzione: uint64_t PyThreadState_GetID (PyThreadState *tstate)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Get the
     unique *note thread state: 182e. identifier of the Python thread
     state 'tstate'.

     'tstate' must not be ‘NULL’, and must be *note attached: 4eba.

     Added in version 3.9.

 -- C Funzione: *note PyInterpreterState: abc.
          *PyThreadState_GetInterpreter (PyThreadState *tstate)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Get the
     interpreter of the Python thread state 'tstate'.

     'tstate' must not be ‘NULL’, and must be *note attached: 4eba.

     Added in version 3.9.

 -- C Funzione: void PyThreadState_EnterTracing (PyThreadState *tstate)

     Suspend tracing and profiling in the Python thread state 'tstate'.

     Resume them using the *note PyThreadState_LeaveTracing(): 95c.
     function.

     Added in version 3.11.

 -- C Funzione: void PyThreadState_LeaveTracing (PyThreadState *tstate)

     Resume tracing and profiling in the Python thread state 'tstate'
     suspended by the *note PyThreadState_EnterTracing(): 95b. function.

     See also *note PyEval_SetTrace(): 663. and *note
     PyEval_SetProfile(): 1704. functions.

     Added in version 3.11.

 -- C Funzione: int PyUnstable_ThreadState_SetStackProtection
          (PyThreadState *tstate, void *stack_start_addr, size_t
          stack_size)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Set the stack protection start address and stack protection size of
     a Python thread state.

     On success, return ‘0’.  On failure, set an exception and return
     ‘-1’.

     CPython implements *note recursion control: 51d7. for C code by
     raising *note RecursionError: f6a. when it notices that the machine
     execution stack is close to overflow.  See for example the *note
     Py_EnterRecursiveCall(): 3d2. function.  For this, it needs to know
     the location of the current thread’s stack, which it normally gets
     from the operating system.  When the stack is changed, for example
     using context switching techniques like the Boost library’s
     ‘boost::context’, you must call *note
     PyUnstable_ThreadState_SetStackProtection(): 466. to inform CPython
     of the change.

     Call *note PyUnstable_ThreadState_SetStackProtection(): 466. either
     before or after changing the stack.  Do not call any other Python C
     API between the call and the stack change.

     See *note PyUnstable_ThreadState_ResetStackProtection(): 467. for
     undoing this operation.

     Added in version 3.14.1:

          Avvertimento: This function was added in a bugfix release, and
          extensions that use it will be incompatible with Python
          3.14.0.  Most packaging tools for Python are not able to
          handle this incompatibility automatically, and will need
          explicit configuration.  When using PyPA standards (wheels and
          source distributions), specify ‘Requires-Python: != 3.14.0.*’
          in core metadata(1).

 -- C Funzione: void PyUnstable_ThreadState_ResetStackProtection
          (PyThreadState *tstate)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Reset the stack protection start address and stack protection size
     of a Python thread state to the operating system defaults.

     See *note PyUnstable_ThreadState_SetStackProtection(): 466. for an
     explanation.

     Added in version 3.14.1:

          Avvertimento: This function was added in a bugfix release, and
          extensions that use it will be incompatible with Python
          3.14.0.  Most packaging tools for Python are not able to
          handle this incompatibility automatically, and will need
          explicit configuration.  When using PyPA standards (wheels and
          source distributions), specify ‘Requires-Python: != 3.14.0.*’
          in core metadata(2).

 -- C Funzione: *note PyInterpreterState: abc. *PyInterpreterState_Get
          (void)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.9.'  Get the
     current interpreter.

     Issue a fatal error if there no *note attached thread state: 4eba.
     It cannot return NULL.

     Added in version 3.9.

 -- C Funzione: int64_t PyInterpreterState_GetID (PyInterpreterState
          *interp)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Return
     the interpreter’s unique ID. If there was any error in doing so
     then ‘-1’ is returned and an error is set.

     The caller must have an *note attached thread state: 4eba.

     Added in version 3.7.

 -- C Funzione: *note PyObject: 5df. *PyInterpreterState_GetDict
          (PyInterpreterState *interp)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776. dalla versione 3.8.'  Return a dictionary
     in which interpreter-specific data may be stored.  If this function
     returns ‘NULL’ then no exception has been raised and the caller
     should assume no interpreter-specific dict is available.

     This is not a replacement for *note PyModule_GetState(): b79, which
     extensions should use to store interpreter-specific state
     information.

     The returned dictionary is borrowed from the interpreter and is
     valid until interpreter shutdown.

     Added in version 3.8.

 -- C Tipo: typedef *note PyObject: 5df. *(*_PyFrameEvalFunction)(*note
          PyThreadState: 991. *tstate, *note _PyInterpreterFrame: 1956.
          *frame, int throwflag)

     Type of a frame evaluation function.

     The 'throwflag' parameter is used by the ‘throw()’ method of
     generators: if non-zero, handle the current exception.

     Cambiato nella versione 3.9: The function now takes a 'tstate'
     parameter.

     Cambiato nella versione 3.11: The 'frame' parameter changed from
     ‘PyFrameObject*’ to ‘_PyInterpreterFrame*’.

 -- C Funzione: *note _PyFrameEvalFunction: 97b.
          _PyInterpreterState_GetEvalFrameFunc (PyInterpreterState
          *interp)

     Get the frame evaluation function.

     See the PEP 523(3) «Adding a frame evaluation API to CPython».

     Added in version 3.9.

 -- C Funzione: void _PyInterpreterState_SetEvalFrameFunc
          (PyInterpreterState *interp, _PyFrameEvalFunction eval_frame)

     Set the frame evaluation function.

     See the PEP 523(4) «Adding a frame evaluation API to CPython».

     Added in version 3.9.

 -- C Funzione: *note PyObject: 5df. *PyThreadState_GetDict ()
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Return a dictionary in which extensions
     can store thread-specific state information.  Each extension should
     use a unique key to use to store state in the dictionary.  It is
     okay to call this function when no *note thread state: 182e. is
     *note attached: 4eba.  If this function returns ‘NULL’, no
     exception has been raised and the caller should assume no thread
     state is attached.

 -- C Funzione: int PyThreadState_SetAsyncExc (unsigned long id,
          PyObject *exc)
     ' Parte del *note ABI Stabile: 776.'  Asynchronously raise an
     exception in a thread.  The 'id' argument is the thread id of the
     target thread; 'exc' is the exception object to be raised.  This
     function does not steal any references to 'exc'.  To prevent naive
     misuse, you must write your own C extension to call this.  Must be
     called with an *note attached thread state: 4eba.  Returns the
     number of thread states modified; this is normally one, but will be
     zero if the thread id isn’t found.  If 'exc' is ‘NULL’, the pending
     exception (if any) for the thread is cleared.  This raises no
     exceptions.

     Cambiato nella versione 3.7: The type of the 'id' parameter changed
     from long to unsigned long.

 -- C Funzione: void PyEval_AcquireThread (PyThreadState *tstate)
     ' Parte del *note ABI Stabile: 776.'  *note Attach: 4eba. 'tstate'
     to the current thread, which must not be ‘NULL’ or already *note
     attached: 4eba.

     The calling thread must not already have an *note attached thread
     state: 4eba.

          Nota: Calling this function from a thread when the runtime is
          finalizing will hang the thread until the program exits, even
          if the thread was not created by Python.  Refer to *note
          Cautions regarding runtime finalization: 54fe. for more
          details.

     Cambiato nella versione 3.8: Updated to be consistent with *note
     PyEval_RestoreThread(): 648, *note Py_END_ALLOW_THREADS(): c81, and
     *note PyGILState_Ensure(): 64a, and terminate the current thread if
     called while the interpreter is finalizing.

     Cambiato nella versione 3.14: Hangs the current thread, rather than
     terminating it, if called while the interpreter is finalizing.

     *note PyEval_RestoreThread(): 648. is a higher-level function which
     is always available (even when threads have not been initialized).

 -- C Funzione: void PyEval_ReleaseThread (PyThreadState *tstate)
     ' Parte del *note ABI Stabile: 776.'  Detach the *note attached
     thread state: 4eba.  The 'tstate' argument, which must not be
     ‘NULL’, is only used to check that it represents the *note attached
     thread state: 4eba. — if it isn’t, a fatal error is reported.

     *note PyEval_SaveThread(): 647. is a higher-level function which is
     always available (even when threads have not been initialized).

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/specifications/core-metadata/#requires-python

   (2) 
https://packaging.python.org/en/latest/specifications/core-metadata/#requires-python

   (3) https://peps.python.org/pep-0523/

   (4) https://peps.python.org/pep-0523/


File: python.info,  Node: Sub-interpreter support,  Next: Asynchronous Notifications,  Prev: Thread State and the Global Interpreter Lock,  Up: Initialization Finalization and Threads

7.10.6 Sub-interpreter support
------------------------------

While in most uses, you will only embed a single Python interpreter,
there are cases where you need to create several independent
interpreters in the same process and perhaps even in the same thread.
Sub-interpreters allow you to do that.

The «main» interpreter is the first one created when the runtime
initializes.  It is usually the only Python interpreter in a process.
Unlike sub-interpreters, the main interpreter has unique process-global
responsibilities like signal handling.  It is also responsible for
execution during runtime initialization and is usually the active
interpreter during runtime finalization.  The *note
PyInterpreterState_Main(): 5508. function returns a pointer to its
state.

You can switch between sub-interpreters using the *note
PyThreadState_Swap(): 509c. function.  You can create and destroy them
using the following functions:

 -- C Tipo: type PyInterpreterConfig

     Structure containing most parameters to configure a
     sub-interpreter.  Its values are used only in *note
     Py_NewInterpreterFromConfig(): 68a. and never modified by the
     runtime.

     Added in version 3.12.

     Structure fields:

      -- C Membro: int use_main_obmalloc

          If this is ‘0’ then the sub-interpreter will use its own
          «object» allocator state.  Otherwise it will use (share) the
          main interpreter’s.

          If this is ‘0’ then *note check_multi_interp_extensions: 5509.
          must be ‘1’ (non-zero).  If this is ‘1’ then *note gil: 550a.
          must not be *note PyInterpreterConfig_OWN_GIL: 550b.

      -- C Membro: int allow_fork

          If this is ‘0’ then the runtime will not support forking the
          process in any thread where the sub-interpreter is currently
          active.  Otherwise fork is unrestricted.

          Note that the *note subprocess: dc. module still works when
          fork is disallowed.

      -- C Membro: int allow_exec

          If this is ‘0’ then the runtime will not support replacing the
          current process via exec (e.g.  *note os.execv(): 2ffe.) in
          any thread where the sub-interpreter is currently active.
          Otherwise exec is unrestricted.

          Note that the *note subprocess: dc. module still works when
          exec is disallowed.

      -- C Membro: int allow_threads

          If this is ‘0’ then the sub-interpreter’s *note threading: f3.
          module won’t create threads.  Otherwise threads are allowed.

      -- C Membro: int allow_daemon_threads

          If this is ‘0’ then the sub-interpreter’s *note threading: f3.
          module won’t create daemon threads.  Otherwise daemon threads
          are allowed (as long as *note allow_threads: 550e. is
          non-zero).

      -- C Membro: int check_multi_interp_extensions

          If this is ‘0’ then all extension modules may be imported,
          including legacy (single-phase init) modules, in any thread
          where the sub-interpreter is currently active.  Otherwise only
          multi-phase init extension modules (see PEP 489(1)) may be
          imported.  (Also see *note Py_mod_multiple_interpreters:
          512a.)

          This must be ‘1’ (non-zero) if *note use_main_obmalloc: 48ff.
          is ‘0’.

      -- C Membro: int gil

          This determines the operation of the GIL for the
          sub-interpreter.  It may be one of the following:

           -- C Macro: PyInterpreterConfig_DEFAULT_GIL

               Use the default selection (*note
               PyInterpreterConfig_SHARED_GIL: 5511.).

           -- C Macro: PyInterpreterConfig_SHARED_GIL

               Use (share) the main interpreter’s GIL.

           -- C Macro: PyInterpreterConfig_OWN_GIL

               Use the sub-interpreter’s own GIL.

          If this is *note PyInterpreterConfig_OWN_GIL: 550b. then *note
          PyInterpreterConfig.use_main_obmalloc: 48ff. must be ‘0’.

 -- C Funzione: *note PyStatus: ba6. Py_NewInterpreterFromConfig
          (PyThreadState **tstate_p, const PyInterpreterConfig *config)

     Create a new sub-interpreter.  This is an (almost) totally separate
     environment for the execution of Python code.  In particular, the
     new interpreter has separate, independent versions of all imported
     modules, including the fundamental modules *note builtins: 13,
     *note __main__: 1. and *note sys: df.  The table of loaded modules
     (‘sys.modules’) and the module search path (‘sys.path’) are also
     separate.  The new environment has no ‘sys.argv’ variable.  It has
     new standard I/O stream file objects ‘sys.stdin’, ‘sys.stdout’ and
     ‘sys.stderr’ (however these refer to the same underlying file
     descriptors).

     The given 'config' controls the options with which the interpreter
     is initialized.

     Upon success, 'tstate_p' will be set to the first *note thread
     state: 182e. created in the new sub-interpreter.  This thread state
     is *note attached: 4eba.  Note that no actual thread is created;
     see the discussion of thread states below.  If creation of the new
     interpreter is unsuccessful, 'tstate_p' is set to ‘NULL’; no
     exception is set since the exception state is stored in the *note
     attached thread state: 4eba, which might not exist.

     Like all other Python/C API functions, an *note attached thread
     state: 4eba. must be present before calling this function, but it
     might be detached upon returning.  On success, the returned thread
     state will be *note attached: 4eba.  If the sub-interpreter is
     created with its own *note GIL: 164. then the *note attached thread
     state: 4eba. of the calling interpreter will be detached.  When the
     function returns, the new interpreter’s *note thread state: 182e.
     will be *note attached: 4eba. to the current thread and the
     previous interpreter’s *note attached thread state: 4eba. will
     remain detached.

     Added in version 3.12.

     Sub-interpreters are most effective when isolated from each other,
     with certain functionality restricted:

          PyInterpreterConfig config = {
              .use_main_obmalloc = 0,
              .allow_fork = 0,
              .allow_exec = 0,
              .allow_threads = 1,
              .allow_daemon_threads = 0,
              .check_multi_interp_extensions = 1,
              .gil = PyInterpreterConfig_OWN_GIL,
          };
          PyThreadState *tstate = NULL;
          PyStatus status = Py_NewInterpreterFromConfig(&tstate, &config);
          if (PyStatus_Exception(status)) {
              Py_ExitStatusException(status);
          }

     Note that the config is used only briefly and does not get
     modified.  During initialization the config’s values are converted
     into various *note PyInterpreterState: abc. values.  A read-only
     copy of the config may be stored internally on the *note
     PyInterpreterState: abc.

     Extension modules are shared between (sub-)interpreters as follows:

        * For modules using multi-phase initialization, e.g.  *note
          PyModule_FromDefAndSpec(): 10b5, a separate module object is
          created and initialized for each interpreter.  Only C-level
          static and global variables are shared between these module
          objects.

        * For modules using single-phase initialization, e.g.  *note
          PyModule_Create(): 51ef, the first time a particular extension
          is imported, it is initialized normally, and a (shallow) copy
          of its module’s dictionary is squirreled away.  When the same
          extension is imported by another (sub-)interpreter, a new
          module is initialized and filled with the contents of this
          copy; the extension’s ‘init’ function is not called.  Objects
          in the module’s dictionary thus end up shared across
          (sub-)interpreters, which might cause unwanted behavior (see
          *note Bugs and caveats: 5512. below).

          Note that this is different from what happens when an
          extension is imported after the interpreter has been
          completely re-initialized by calling *note Py_FinalizeEx():
          f13. and *note Py_Initialize(): 460.; in that case, the
          extension’s ‘initmodule’ function 'is' called again.  As with
          multi-phase initialization, this means that only C-level
          static and global variables are shared between these modules.

 -- C Funzione: *note PyThreadState: 991. *Py_NewInterpreter (void)
     ' Parte del *note ABI Stabile: 776.'

     Create a new sub-interpreter.  This is essentially just a wrapper
     around *note Py_NewInterpreterFromConfig(): 68a. with a config that
     preserves the existing behavior.  The result is an unisolated
     sub-interpreter that shares the main interpreter’s GIL, allows
     fork/exec, allows daemon threads, and allows single-phase init
     modules.

 -- C Funzione: void Py_EndInterpreter (PyThreadState *tstate)
     ' Parte del *note ABI Stabile: 776.'

     Destroy the (sub-)interpreter represented by the given *note thread
     state: 182e.  The given thread state must be *note attached: 4eba.
     When the call returns, there will be no *note attached thread
     state: 4eba.  All thread states associated with this interpreter
     are destroyed.

     *note Py_FinalizeEx(): f13. will destroy all sub-interpreters that
     haven’t been explicitly destroyed at that point.

* Menu:

* A Per-Interpreter GIL::
* Bugs and caveats::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0489/


File: python.info,  Node: A Per-Interpreter GIL,  Next: Bugs and caveats,  Up: Sub-interpreter support

7.10.6.1 A Per-Interpreter GIL
..............................

Using *note Py_NewInterpreterFromConfig(): 68a. you can create a
sub-interpreter that is completely isolated from other interpreters,
including having its own GIL. The most important benefit of this
isolation is that such an interpreter can execute Python code without
being blocked by other interpreters or blocking any others.  Thus a
single Python process can truly take advantage of multiple CPU cores
when running Python code.  The isolation also encourages a different
approach to concurrency than that of just using threads.  (See PEP
554(1) and PEP 684(2).)

Using an isolated interpreter requires vigilance in preserving that
isolation.  That especially means not sharing any objects or mutable
state without guarantees about thread-safety.  Even objects that are
otherwise immutable (e.g.  ‘None’, ‘(1, 5)’) can’t normally be shared
because of the refcount.  One simple but less-efficient approach around
this is to use a global lock around all use of some state (or object).
Alternately, effectively immutable objects (like integers or strings)
can be made safe in spite of their refcounts by making them *note
immortal: 290.  In fact, this has been done for the builtin singletons,
small integers, and a number of other builtin objects.

If you preserve isolation then you will have access to proper multi-core
computing without the complications that come with free-threading.
Failure to preserve isolation will expose you to the full consequences
of free-threading, including races and hard-to-debug crashes.

Aside from that, one of the main challenges of using multiple isolated
interpreters is how to communicate between them safely (not break
isolation) and efficiently.  The runtime and stdlib do not provide any
standard approach to this yet.  A future stdlib module would help
mitigate the effort of preserving isolation and expose effective tools
for communicating (and sharing) data between interpreters.

Added in version 3.12.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0554/

   (2) https://peps.python.org/pep-0684/


File: python.info,  Node: Bugs and caveats,  Prev: A Per-Interpreter GIL,  Up: Sub-interpreter support

7.10.6.2 Bugs and caveats
.........................

Because sub-interpreters (and the main interpreter) are part of the same
process, the insulation between them isn’t perfect — for example, using
low-level file operations like *note os.close(): d6d. they can
(accidentally or maliciously) affect each other’s open files.  Because
of the way extensions are shared between (sub-)interpreters, some
extensions may not work properly; this is especially likely when using
single-phase initialization or (static) global variables.  It is
possible to insert objects created in one sub-interpreter into a
namespace of another (sub-)interpreter; this should be avoided if
possible.

Special care should be taken to avoid sharing user-defined functions,
methods, instances or classes between sub-interpreters, since import
operations executed by such objects may affect the wrong
(sub-)interpreter’s dictionary of loaded modules.  It is equally
important to avoid sharing objects from which the above are reachable.

Also note that combining this functionality with ‘PyGILState_*’ APIs is
delicate, because these APIs assume a bijection between Python thread
states and OS-level threads, an assumption broken by the presence of
sub-interpreters.  It is highly recommended that you don’t switch
sub-interpreters between a pair of matching *note PyGILState_Ensure():
64a. and *note PyGILState_Release(): 64b. calls.  Furthermore,
extensions (such as *note ctypes: 2e.) using these APIs to allow calling
of Python code from non-Python created threads will probably be broken
when using sub-interpreters.


File: python.info,  Node: Asynchronous Notifications,  Next: Profiling and Tracing,  Prev: Sub-interpreter support,  Up: Initialization Finalization and Threads

7.10.7 Asynchronous Notifications
---------------------------------

A mechanism is provided to make asynchronous notifications to the main
interpreter thread.  These notifications take the form of a function
pointer and a void pointer argument.

 -- C Funzione: int Py_AddPendingCall (int (*func)(void*), void *arg)
     ' Parte del *note ABI Stabile: 776.'  Schedule a function to be
     called from the main interpreter thread.  On success, ‘0’ is
     returned and 'func' is queued for being called in the main thread.
     On failure, ‘-1’ is returned without setting any exception.

     When successfully queued, 'func' will be 'eventually' called from
     the main interpreter thread with the argument 'arg'.  It will be
     called asynchronously with respect to normally running Python code,
     but with both these conditions met:

        * on a *note bytecode: 4ab. boundary;

        * with the main thread holding an *note attached thread state:
          4eba. ('func' can therefore use the full C API).

     'func' must return ‘0’ on success, or ‘-1’ on failure with an
     exception set.  'func' won’t be interrupted to perform another
     asynchronous notification recursively, but it can still be
     interrupted to switch threads if the *note thread state: 4eba. is
     detached.

     This function doesn’t need an *note attached thread state: 4eba.
     However, to call this function in a subinterpreter, the caller must
     have an *note attached thread state: 4eba.  Otherwise, the function
     'func' can be scheduled to be called from the wrong interpreter.

          Avvertimento: This is a low-level function, only useful for
          very special cases.  There is no guarantee that 'func' will be
          called as quick as possible.  If the main thread is busy
          executing a system call, 'func' won’t be called before the
          system call returns.  This function is generally 'not'
          suitable for calling Python code from arbitrary C threads.
          Instead, use the *note PyGILState API: 54fa.

     Added in version 3.1.

     Cambiato nella versione 3.9: If this function is called in a
     subinterpreter, the function 'func' is now scheduled to be called
     from the subinterpreter, rather than being called from the main
     interpreter.  Each subinterpreter now has its own list of scheduled
     calls.

     Cambiato nella versione 3.12: This function now always schedules
     'func' to be run in the main interpreter.

 -- C Funzione: int Py_MakePendingCalls (void)
     ' Parte del *note ABI Stabile: 776.'  Execute all pending calls.
     This is usually executed automatically by the interpreter.

     This function returns ‘0’ on success, and returns ‘-1’ with an
     exception set on failure.

     If this is not called in the main thread of the main interpreter,
     this function does nothing and returns ‘0’.  The caller must hold
     an *note attached thread state: 4eba.

     Added in version 3.1.

     Cambiato nella versione 3.12: This function only runs pending calls
     in the main interpreter.


File: python.info,  Node: Profiling and Tracing,  Next: Reference tracing,  Prev: Asynchronous Notifications,  Up: Initialization Finalization and Threads

7.10.8 Profiling and Tracing
----------------------------

The Python interpreter provides some low-level support for attaching
profiling and execution tracing facilities.  These are used for
profiling, debugging, and coverage analysis tools.

This C interface allows the profiling or tracing code to avoid the
overhead of calling through Python-level callable objects, making a
direct C function call instead.  The essential attributes of the
facility have not changed; the interface allows trace functions to be
installed per-thread, and the basic events reported to the trace
function are the same as had been reported to the Python-level trace
functions in previous versions.

 -- C Tipo: typedef int (*Py_tracefunc)(*note PyObject: 5df. *obj, *note
          PyFrameObject: 98d. *frame, int what, *note PyObject: 5df.
          *arg)

     The type of the trace function registered using *note
     PyEval_SetProfile(): 1704. and *note PyEval_SetTrace(): 663.  The
     first parameter is the object passed to the registration function
     as 'obj', 'frame' is the frame object to which the event pertains,
     'what' is one of the constants *note PyTrace_CALL: 5518, *note
     PyTrace_EXCEPTION: 5519, *note PyTrace_LINE: 551a, *note
     PyTrace_RETURN: 551b, *note PyTrace_C_CALL: 551c, *note
     PyTrace_C_EXCEPTION: 551d, *note PyTrace_C_RETURN: 551e, or *note
     PyTrace_OPCODE: 551f, and 'arg' depends on the value of 'what':

     Value of 'what'                     Meaning of 'arg'
                                         
     ---------------------------------------------------------------------------------
                                         
     *note PyTrace_CALL: 5518.           Always *note Py_None: 4e88.
                                         
                                         
     *note PyTrace_EXCEPTION: 5519.      Exception information as returned by
                                         *note sys.exc_info(): 89b.
                                         
                                         
     *note PyTrace_LINE: 551a.           Always *note Py_None: 4e88.
                                         
                                         
     *note PyTrace_RETURN: 551b.         Value being returned to the caller, or
                                         ‘NULL’ if caused by an exception.
                                         
                                         
     *note PyTrace_C_CALL: 551c.         Function object being called.
                                         
                                         
     *note PyTrace_C_EXCEPTION: 551d.    Function object being called.
                                         
                                         
     *note PyTrace_C_RETURN: 551e.       Function object being called.
                                         
                                         
     *note PyTrace_OPCODE: 551f.         Always *note Py_None: 4e88.
                                         

 -- C Variabile: int PyTrace_CALL

     The value of the 'what' parameter to a *note Py_tracefunc: 5517.
     function when a new call to a function or method is being reported,
     or a new entry into a generator.  Note that the creation of the
     iterator for a generator function is not reported as there is no
     control transfer to the Python bytecode in the corresponding frame.

 -- C Variabile: int PyTrace_EXCEPTION

     The value of the 'what' parameter to a *note Py_tracefunc: 5517.
     function when an exception has been raised.  The callback function
     is called with this value for 'what' when after any bytecode is
     processed after which the exception becomes set within the frame
     being executed.  The effect of this is that as exception
     propagation causes the Python stack to unwind, the callback is
     called upon return to each frame as the exception propagates.  Only
     trace functions receives these events; they are not needed by the
     profiler.

 -- C Variabile: int PyTrace_LINE

     The value passed as the 'what' parameter to a *note Py_tracefunc:
     5517. function (but not a profiling function) when a line-number
     event is being reported.  It may be disabled for a frame by setting
     *note f_trace_lines: dd8. to '0' on that frame.

 -- C Variabile: int PyTrace_RETURN

     The value for the 'what' parameter to *note Py_tracefunc: 5517.
     functions when a call is about to return.

 -- C Variabile: int PyTrace_C_CALL

     The value for the 'what' parameter to *note Py_tracefunc: 5517.
     functions when a C function is about to be called.

 -- C Variabile: int PyTrace_C_EXCEPTION

     The value for the 'what' parameter to *note Py_tracefunc: 5517.
     functions when a C function has raised an exception.

 -- C Variabile: int PyTrace_C_RETURN

     The value for the 'what' parameter to *note Py_tracefunc: 5517.
     functions when a C function has returned.

 -- C Variabile: int PyTrace_OPCODE

     The value for the 'what' parameter to *note Py_tracefunc: 5517.
     functions (but not profiling functions) when a new opcode is about
     to be executed.  This event is not emitted by default: it must be
     explicitly requested by setting *note f_trace_opcodes: dd9. to '1'
     on the frame.

 -- C Funzione: void PyEval_SetProfile (Py_tracefunc func, PyObject
          *obj)

     Set the profiler function to 'func'.  The 'obj' parameter is passed
     to the function as its first parameter, and may be any Python
     object, or ‘NULL’.  If the profile function needs to maintain
     state, using a different value for 'obj' for each thread provides a
     convenient and thread-safe place to store it.  The profile function
     is called for all monitored events except *note PyTrace_LINE: 551a.
     *note PyTrace_OPCODE: 551f. and *note PyTrace_EXCEPTION: 5519.

     See also the *note sys.setprofile(): 1705. function.

     The caller must have an *note attached thread state: 4eba.

 -- C Funzione: void PyEval_SetProfileAllThreads (Py_tracefunc func,
          PyObject *obj)

     Like *note PyEval_SetProfile(): 1704. but sets the profile function
     in all running threads belonging to the current interpreter instead
     of the setting it only on the current thread.

     The caller must have an *note attached thread state: 4eba.

     As *note PyEval_SetProfile(): 1704, this function ignores any
     exceptions raised while setting the profile functions in all
     threads.

Added in version 3.12.

 -- C Funzione: void PyEval_SetTrace (Py_tracefunc func, PyObject *obj)

     Set the tracing function to 'func'.  This is similar to *note
     PyEval_SetProfile(): 1704, except the tracing function does receive
     line-number events and per-opcode events, but does not receive any
     event related to C function objects being called.  Any trace
     function registered using *note PyEval_SetTrace(): 663. will not
     receive *note PyTrace_C_CALL: 551c, *note PyTrace_C_EXCEPTION:
     551d. or *note PyTrace_C_RETURN: 551e. as a value for the 'what'
     parameter.

     See also the *note sys.settrace(): 2e1. function.

     The caller must have an *note attached thread state: 4eba.

 -- C Funzione: void PyEval_SetTraceAllThreads (Py_tracefunc func,
          PyObject *obj)

     Like *note PyEval_SetTrace(): 663. but sets the tracing function in
     all running threads belonging to the current interpreter instead of
     the setting it only on the current thread.

     The caller must have an *note attached thread state: 4eba.

     As *note PyEval_SetTrace(): 663, this function ignores any
     exceptions raised while setting the trace functions in all threads.

Added in version 3.12.


File: python.info,  Node: Reference tracing,  Next: Advanced Debugger Support,  Prev: Profiling and Tracing,  Up: Initialization Finalization and Threads

7.10.9 Reference tracing
------------------------

Added in version 3.13.

 -- C Tipo: typedef int (*PyRefTracer)(*note PyObject: 5df.*, int event,
          void *data)

     The type of the trace function registered using *note
     PyRefTracer_SetTracer(): 610.  The first parameter is a Python
     object that has been just created (when 'event' is set to *note
     PyRefTracer_CREATE: 5522.) or about to be destroyed (when 'event'
     is set to *note PyRefTracer_DESTROY: 5523.).  The 'data' argument
     is the opaque pointer that was provided when *note
     PyRefTracer_SetTracer(): 610. was called.

Added in version 3.13.

 -- C Variabile: int PyRefTracer_CREATE

     The value for the 'event' parameter to *note PyRefTracer: 5521.
     functions when a Python object has been created.

 -- C Variabile: int PyRefTracer_DESTROY

     The value for the 'event' parameter to *note PyRefTracer: 5521.
     functions when a Python object has been destroyed.

 -- C Funzione: int PyRefTracer_SetTracer (PyRefTracer tracer, void
          *data)

     Register a reference tracer function.  The function will be called
     when a new Python has been created or when an object is going to be
     destroyed.  If 'data' is provided it must be an opaque pointer that
     will be provided when the tracer function is called.  Return ‘0’ on
     success.  Set an exception and return ‘-1’ on error.

     Not that tracer functions 'must not' create Python objects inside
     or otherwise the call will be re-entrant.  The tracer also 'must
     not' clear any existing exception or set an exception.  A *note
     thread state: 182e. will be active every time the tracer function
     is called.

     There must be an *note attached thread state: 4eba. when calling
     this function.

Added in version 3.13.

 -- C Funzione: *note PyRefTracer: 5521. PyRefTracer_GetTracer (void
          **data)

     Get the registered reference tracer function and the value of the
     opaque data pointer that was registered when *note
     PyRefTracer_SetTracer(): 610. was called.  If no tracer was
     registered this function will return NULL and will set the 'data'
     pointer to NULL.

     There must be an *note attached thread state: 4eba. when calling
     this function.

Added in version 3.13.


File: python.info,  Node: Advanced Debugger Support,  Next: Thread Local Storage Support,  Prev: Reference tracing,  Up: Initialization Finalization and Threads

7.10.10 Advanced Debugger Support
---------------------------------

These functions are only intended to be used by advanced debugging
tools.

 -- C Funzione: *note PyInterpreterState: abc. *PyInterpreterState_Head
          ()

     Return the interpreter state object at the head of the list of all
     such objects.

 -- C Funzione: *note PyInterpreterState: abc. *PyInterpreterState_Main
          ()

     Return the main interpreter state object.

 -- C Funzione: *note PyInterpreterState: abc. *PyInterpreterState_Next
          (PyInterpreterState *interp)

     Return the next interpreter state object after 'interp' from the
     list of all such objects.

 -- C Funzione: *note PyThreadState: 991. *PyInterpreterState_ThreadHead
          (PyInterpreterState *interp)

     Return the pointer to the first *note PyThreadState: 991. object in
     the list of threads associated with the interpreter 'interp'.

 -- C Funzione: *note PyThreadState: 991. *PyThreadState_Next
          (PyThreadState *tstate)

     Return the next thread state object after 'tstate' from the list of
     all such objects belonging to the same *note PyInterpreterState:
     abc. object.


File: python.info,  Node: Thread Local Storage Support,  Next: Synchronization Primitives<2>,  Prev: Advanced Debugger Support,  Up: Initialization Finalization and Threads

7.10.11 Thread Local Storage Support
------------------------------------

The Python interpreter provides low-level support for thread-local
storage (TLS) which wraps the underlying native TLS implementation to
support the Python-level thread local storage API (*note
threading.local: 1847.).  The CPython C level APIs are similar to those
offered by pthreads and Windows: use a thread key and functions to
associate a void* value per thread.

A *note thread state: 182e. does 'not' need to be *note attached: 4eba.
when calling these functions; they suppl their own locking.

Note that ‘Python.h’ does not include the declaration of the TLS APIs,
you need to include ‘pythread.h’ to use thread-local storage.

     Nota: None of these API functions handle memory management on
     behalf of the void* values.  You need to allocate and deallocate
     them yourself.  If the void* values happen to be *note PyObject:
     5df.*, these functions don’t do refcount operations on them either.

* Menu:

* Thread Specific Storage (TSS) API: Thread Specific Storage TSS API.
* Thread Local Storage (TLS) API: Thread Local Storage TLS API.


File: python.info,  Node: Thread Specific Storage TSS API,  Next: Thread Local Storage TLS API,  Up: Thread Local Storage Support

7.10.11.1 Thread Specific Storage (TSS) API
...........................................

TSS API is introduced to supersede the use of the existing TLS API
within the CPython interpreter.  This API uses a new type *note
Py_tss_t: cd8. instead of int to represent thread keys.

Added in version 3.7.

Vedi anche
..........

«A New C-API for Thread-Local Storage in CPython» ( PEP 539(1))

 -- C Tipo: type Py_tss_t

     This data structure represents the state of a thread key, the
     definition of which may depend on the underlying TLS
     implementation, and it has an internal field representing the key’s
     initialization state.  There are no public members in this
     structure.

     When *note Py_LIMITED_API: 776. is not defined, static allocation
     of this type by *note Py_tss_NEEDS_INIT: 5529. is allowed.

 -- C Macro: Py_tss_NEEDS_INIT

     This macro expands to the initializer for *note Py_tss_t: cd8.
     variables.  Note that this macro won’t be defined with *note
     Py_LIMITED_API: 776.

* Menu:

* Dynamic Allocation::
* Methods::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0539/


File: python.info,  Node: Dynamic Allocation,  Next: Methods,  Up: Thread Specific Storage TSS API

7.10.11.2 Dynamic Allocation
............................

Dynamic allocation of the *note Py_tss_t: cd8, required in extension
modules built with *note Py_LIMITED_API: 776, where static allocation of
this type is not possible due to its implementation being opaque at
build time.

 -- C Funzione: *note Py_tss_t: cd8. *PyThread_tss_alloc ()
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Return a
     value which is the same state as a value initialized with *note
     Py_tss_NEEDS_INIT: 5529, or ‘NULL’ in the case of dynamic
     allocation failure.

 -- C Funzione: void PyThread_tss_free (Py_tss_t *key)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Free the
     given 'key' allocated by *note PyThread_tss_alloc(): 438, after
     first calling *note PyThread_tss_delete(): 440. to ensure any
     associated thread locals have been unassigned.  This is a no-op if
     the 'key' argument is ‘NULL’.

          Nota: A freed key becomes a dangling pointer.  You should
          reset the key to ‘NULL’.


File: python.info,  Node: Methods,  Prev: Dynamic Allocation,  Up: Thread Specific Storage TSS API

7.10.11.3 Methods
.................

The parameter 'key' of these functions must not be ‘NULL’.  Moreover,
the behaviors of *note PyThread_tss_set(): 43c. and *note
PyThread_tss_get(): 43e. are undefined if the given *note Py_tss_t: cd8.
has not been initialized by *note PyThread_tss_create(): 50a8.

 -- C Funzione: int PyThread_tss_is_created (Py_tss_t *key)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Return a
     non-zero value if the given *note Py_tss_t: cd8. has been
     initialized by *note PyThread_tss_create(): 50a8.

 -- C Funzione: int PyThread_tss_create (Py_tss_t *key)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Return a
     zero value on successful initialization of a TSS key.  The behavior
     is undefined if the value pointed to by the 'key' argument is not
     initialized by *note Py_tss_NEEDS_INIT: 5529.  This function can be
     called repeatedly on the same key – calling it on an already
     initialized key is a no-op and immediately returns success.

 -- C Funzione: void PyThread_tss_delete (Py_tss_t *key)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Destroy a
     TSS key to forget the values associated with the key across all
     threads, and change the key’s initialization state to
     uninitialized.  A destroyed key is able to be initialized again by
     *note PyThread_tss_create(): 50a8.  This function can be called
     repeatedly on the same key – calling it on an already destroyed key
     is a no-op.

 -- C Funzione: int PyThread_tss_set (Py_tss_t *key, void *value)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Return a
     zero value to indicate successfully associating a void* value with
     a TSS key in the current thread.  Each thread has a distinct
     mapping of the key to a void* value.

 -- C Funzione: void *PyThread_tss_get (Py_tss_t *key)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Return
     the void* value associated with a TSS key in the current thread.
     This returns ‘NULL’ if no value is associated with the key in the
     current thread.


File: python.info,  Node: Thread Local Storage TLS API,  Prev: Thread Specific Storage TSS API,  Up: Thread Local Storage Support

7.10.11.4 Thread Local Storage (TLS) API
........................................

Deprecato dalla versione 3.7: This API is superseded by *note Thread
Specific Storage (TSS) API: cd7.

     Nota: This version of the API does not support platforms where the
     native TLS key is defined in a way that cannot be safely cast to
     ‘int’.  On such platforms, *note PyThread_create_key(): 437. will
     return immediately with a failure status, and the other TLS
     functions will all be no-ops on such platforms.

Due to the compatibility problem noted above, this version of the API
should not be used in new code.

 -- C Funzione: int PyThread_create_key ()
     ' Parte del *note ABI Stabile: 776.'

 -- C Funzione: void PyThread_delete_key (int key)
     ' Parte del *note ABI Stabile: 776.'

 -- C Funzione: int PyThread_set_key_value (int key, void *value)
     ' Parte del *note ABI Stabile: 776.'

 -- C Funzione: void *PyThread_get_key_value (int key)
     ' Parte del *note ABI Stabile: 776.'

 -- C Funzione: void PyThread_delete_key_value (int key)
     ' Parte del *note ABI Stabile: 776.'

 -- C Funzione: void PyThread_ReInitTLS ()
     ' Parte del *note ABI Stabile: 776.'


File: python.info,  Node: Synchronization Primitives<2>,  Next: Operating System Thread APIs,  Prev: Thread Local Storage Support,  Up: Initialization Finalization and Threads

7.10.12 Synchronization Primitives
----------------------------------

The C-API provides a basic mutual exclusion lock.

 -- C Tipo: type PyMutex

     A mutual exclusion lock.  The ‘PyMutex’ should be initialized to
     zero to represent the unlocked state.  For example:

          PyMutex mutex = {0};

     Instances of ‘PyMutex’ should not be copied or moved.  Both the
     contents and address of a ‘PyMutex’ are meaningful, and it must
     remain at a fixed, writable location in memory.

          Nota: A ‘PyMutex’ currently occupies one byte, but the size
          should be considered unstable.  The size may change in future
          Python releases without a deprecation period.

     Added in version 3.13.

 -- C Funzione: void PyMutex_Lock (PyMutex *m)

     Lock mutex 'm'.  If another thread has already locked it, the
     calling thread will block until the mutex is unlocked.  While
     blocked, the thread will temporarily detach the *note thread state:
     4eba. if one exists.

     Added in version 3.13.

 -- C Funzione: void PyMutex_Unlock (PyMutex *m)

     Unlock mutex 'm'.  The mutex must be locked — otherwise, the
     function will issue a fatal error.

     Added in version 3.13.

 -- C Funzione: int PyMutex_IsLocked (PyMutex *m)

     Returns non-zero if the mutex 'm' is currently locked, zero
     otherwise.

          Nota: This function is intended for use in assertions and
          debugging only and should not be used to make concurrency
          control decisions, as the lock state may change immediately
          after the check.

     Added in version 3.14.

* Menu:

* Python Critical Section API::
* Legacy Locking APIs::


File: python.info,  Node: Python Critical Section API,  Next: Legacy Locking APIs,  Up: Synchronization Primitives<2>

7.10.12.1 Python Critical Section API
.....................................

The critical section API provides a deadlock avoidance layer on top of
per-object locks for *note free-threaded: 1f4. CPython.  They are
intended to replace reliance on the *note global interpreter lock: 474,
and are no-ops in versions of Python with the global interpreter lock.

Critical sections are intended to be used for custom types implemented
in C-API extensions.  They should generally not be used with built-in
types like *note list: 24d. and *note dict: 183. because their public
C-APIs already use critical sections internally, with the notable
exception of *note PyDict_Next(): 1977, which requires critical section
to be acquired externally.

Critical sections avoid deadlocks by implicitly suspending active
critical sections, hence, they do not provide exclusive access such as
provided by traditional locks like *note PyMutex: 485.  When a critical
section is started, the per-object lock for the object is acquired.  If
the code executed inside the critical section calls C-API functions then
it can suspend the critical section thereby releasing the per-object
lock, so other threads can acquire the per-object lock for the same
object.

Variants that accept *note PyMutex: 485. pointers rather than Python
objects are also available.  Use these variants to start a critical
section in a situation where there is no *note PyObject: 5df. – for
example, when working with a C type that does not extend or wrap *note
PyObject: 5df. but still needs to call into the C API in a manner that
might lead to deadlocks.

The functions and structs used by the macros are exposed for cases where
C macros are not available.  They should only be used as in the given
macro expansions.  Note that the sizes and contents of the structures
may change in future Python versions.

     Nota: Operations that need to lock two objects at once must use
     *note Py_BEGIN_CRITICAL_SECTION2: 5530.  You 'cannot' use nested
     critical sections to lock more than one object at once, because the
     inner critical section may suspend the outer critical sections.
     This API does not provide a way to lock more than two objects at
     once.

Example usage:

     static PyObject *
     set_field(MyObject *self, PyObject *value)
     {
        Py_BEGIN_CRITICAL_SECTION(self);
        Py_SETREF(self->field, Py_XNewRef(value));
        Py_END_CRITICAL_SECTION();
        Py_RETURN_NONE;
     }

In the above example, *note Py_SETREF: 79a. calls *note Py_DECREF: 791,
which can call arbitrary code through an object’s deallocation function.
The critical section API avoids potential deadlocks due to reentrancy
and lock ordering by allowing the runtime to temporarily suspend the
critical section if the code triggered by the finalizer blocks and calls
*note PyEval_SaveThread(): 647.

 -- C Macro: Py_BEGIN_CRITICAL_SECTION (op)

     Acquires the per-object lock for the object 'op' and begins a
     critical section.

     In the free-threaded build, this macro expands to:

          {
              PyCriticalSection _py_cs;
              PyCriticalSection_Begin(&_py_cs, (PyObject*)(op))

     In the default build, this macro expands to ‘{’.

     Added in version 3.13.

 -- C Macro: Py_BEGIN_CRITICAL_SECTION_MUTEX (m)

     Locks the mutex 'm' and begins a critical section.

     In the free-threaded build, this macro expands to:

          {
               PyCriticalSection _py_cs;
               PyCriticalSection_BeginMutex(&_py_cs, m)

     Note that unlike *note Py_BEGIN_CRITICAL_SECTION: 5384, there is no
     cast for the argument of the macro - it must be a *note PyMutex:
     485. pointer.

     On the default build, this macro expands to ‘{’.

     Added in version 3.14.

 -- C Macro: Py_END_CRITICAL_SECTION ()

     Ends the critical section and releases the per-object lock.

     In the free-threaded build, this macro expands to:

              PyCriticalSection_End(&_py_cs);
          }

     In the default build, this macro expands to ‘}’.

     Added in version 3.13.

 -- C Macro: Py_BEGIN_CRITICAL_SECTION2 (a, b)

     Acquires the per-objects locks for the objects 'a' and 'b' and
     begins a critical section.  The locks are acquired in a consistent
     order (lowest address first) to avoid lock ordering deadlocks.

     In the free-threaded build, this macro expands to:

          {
              PyCriticalSection2 _py_cs2;
              PyCriticalSection2_Begin(&_py_cs2, (PyObject*)(a), (PyObject*)(b))

     In the default build, this macro expands to ‘{’.

     Added in version 3.13.

 -- C Macro: Py_BEGIN_CRITICAL_SECTION2_MUTEX (m1, m2)

     Locks the mutexes 'm1' and 'm2' and begins a critical section.

     In the free-threaded build, this macro expands to:

          {
               PyCriticalSection2 _py_cs2;
               PyCriticalSection2_BeginMutex(&_py_cs2, m1, m2)

     Note that unlike *note Py_BEGIN_CRITICAL_SECTION2: 5530, there is
     no cast for the arguments of the macro - they must be *note
     PyMutex: 485. pointers.

     On the default build, this macro expands to ‘{’.

     Added in version 3.14.

 -- C Macro: Py_END_CRITICAL_SECTION2 ()

     Ends the critical section and releases the per-object locks.

     In the free-threaded build, this macro expands to:

              PyCriticalSection2_End(&_py_cs2);
          }

     In the default build, this macro expands to ‘}’.

     Added in version 3.13.


File: python.info,  Node: Legacy Locking APIs,  Prev: Python Critical Section API,  Up: Synchronization Primitives<2>

7.10.12.2 Legacy Locking APIs
.............................

These APIs are obsolete since Python 3.13 with the introduction of *note
PyMutex: 485.

Cambiato nella versione 3.15: These APIs are now a simple wrapper around
‘PyMutex’.

 -- C Tipo: type PyThread_type_lock

     A pointer to a mutual exclusion lock.

 -- C Tipo: type PyLockStatus

     The result of acquiring a lock with a timeout.

      -- C Enumeratore: enumerator PY_LOCK_FAILURE

          Failed to acquire the lock.

      -- C Enumeratore: enumerator PY_LOCK_ACQUIRED

          The lock was successfully acquired.

      -- C Enumeratore: enumerator PY_LOCK_INTR

          The lock was interrupted by a signal.

 -- C Funzione: *note PyThread_type_lock: 5536. PyThread_allocate_lock
          (void)
     ' Parte del *note ABI Stabile: 776.'  Allocate a new lock.

     On success, this function returns a lock; on failure, this function
     returns ‘0’ without an exception set.

     The caller does not need to hold an *note attached thread state:
     4eba.

     Cambiato nella versione 3.15: This function now always uses *note
     PyMutex: 485.  In prior versions, this would use a lock provided by
     the operating system.

 -- C Funzione: void PyThread_free_lock (PyThread_type_lock lock)
     ' Parte del *note ABI Stabile: 776.'  Destroy 'lock'.  The lock
     should not be held by any thread when calling this.

     The caller does not need to hold an *note attached thread state:
     4eba.

 -- C Funzione: *note PyLockStatus: 5537. PyThread_acquire_lock_timed
          (PyThread_type_lock lock, long long microseconds, int
          intr_flag)
     ' Parte del *note ABI Stabile: 776.'  Acquire 'lock' with a
     timeout.

     This will wait for 'microseconds' microseconds to acquire the lock.
     If the timeout expires, this function returns *note
     PY_LOCK_FAILURE: 5538.  If 'microseconds' is ‘-1’, this will wait
     indefinitely until the lock has been released.

     If 'intr_flag' is ‘1’, acquiring the lock may be interrupted by a
     signal, in which case this function returns *note PY_LOCK_INTR:
     553a.  Upon interruption, it’s generally expected that the caller
     makes a call to *note Py_MakePendingCalls(): 510c. to propagate an
     exception to Python code.

     If the lock is successfully acquired, this function returns *note
     PY_LOCK_ACQUIRED: 5539.

     The caller does not need to hold an *note attached thread state:
     4eba.

 -- C Funzione: int PyThread_acquire_lock (PyThread_type_lock lock, int
          waitflag)
     ' Parte del *note ABI Stabile: 776.'  Acquire 'lock'.

     If 'waitflag' is ‘1’ and another thread currently holds the lock,
     this function will wait until the lock can be acquired and will
     always return ‘1’.

     If 'waitflag' is ‘0’ and another thread holds the lock, this
     function will not wait and instead return ‘0’.  If the lock is not
     held by any other thread, then this function will acquire it and
     return ‘1’.

     Unlike *note PyThread_acquire_lock_timed(): 509f, acquiring the
     lock cannot be interrupted by a signal.

     The caller does not need to hold an *note attached thread state:
     4eba.

 -- C Funzione: int PyThread_release_lock (PyThread_type_lock lock)
     ' Parte del *note ABI Stabile: 776.'  Release 'lock'.  If 'lock' is
     not held, then this function issues a fatal error.

     The caller does not need to hold an *note attached thread state:
     4eba.


File: python.info,  Node: Operating System Thread APIs,  Prev: Synchronization Primitives<2>,  Up: Initialization Finalization and Threads

7.10.13 Operating System Thread APIs
------------------------------------

 -- C Macro: PYTHREAD_INVALID_THREAD_ID

     Sentinel value for an invalid thread ID.

     This is currently equivalent to ‘(unsigned long)-1’.

 -- C Funzione: unsigned long PyThread_start_new_thread (void
          (*func)(void*), void *arg)
     ' Parte del *note ABI Stabile: 776.'  Start function 'func' in a
     new thread with argument 'arg'.  The resulting thread is not
     intended to be joined.

     'func' must not be ‘NULL’, but 'arg' may be ‘NULL’.

     On success, this function returns the identifier of the new thread;
     on failure, this returns *note PYTHREAD_INVALID_THREAD_ID: 553c.

     The caller does not need to hold an *note attached thread state:
     4eba.

 -- C Funzione: unsigned long PyThread_get_thread_ident (void)
     ' Parte del *note ABI Stabile: 776.'  Return the identifier of the
     current thread, which will never be zero.

     This function cannot fail, and the caller does not need to hold an
     *note attached thread state: 4eba.

     Vedi anche
     ..........

     *note threading.get_ident(): 1362.

 -- C Funzione: *note PyObject: 5df. *PyThread_GetInfo (void)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.3.'  Get
     general information about the current thread in the form of a *note
     struct sequence: 13c7. object.  This information is accessible as
     *note sys.thread_info: 1358. in Python.

     On success, this returns a new *note strong reference: 5e2. to the
     thread information; on failure, this returns ‘NULL’ with an
     exception set.

     The caller must hold an *note attached thread state: 4eba.

 -- C Macro: PY_HAVE_THREAD_NATIVE_ID

     This macro is defined when the system supports native thread IDs.

 -- C Funzione: unsigned long PyThread_get_thread_native_id (void)
     ' Parte del *note ABI Stabile: 776. on platforms with native thread
     IDs.'  Get the native identifier of the current thread as it was
     assigned by the operating system’s kernel, which will never be less
     than zero.

     This function is only available when *note
     PY_HAVE_THREAD_NATIVE_ID: 553d. is defined.

     This function cannot fail, and the caller does not need to hold an
     *note attached thread state: 4eba.

     Vedi anche
     ..........

     *note threading.get_native_id(): c34.

 -- C Funzione: void PyThread_exit_thread (void)
     ' Parte del *note ABI Stabile: 776.'  Terminate the current thread.
     This function is generally considered unsafe and should be avoided.
     It is kept solely for backwards compatibility.

     This function is only safe to call if all functions in the full
     call stack are written to safely allow it.

          Avvertimento: If the current system uses POSIX threads (also
          known as «pthreads»), this calls ‘pthread_exit(3)(1)’, which
          attempts to unwind the stack and call C++ destructors on some
          libc implementations.  However, if a ‘noexcept’ function is
          reached, it may terminate the process.  Other systems, such as
          macOS, do unwinding.

          On Windows, this function calls ‘_endthreadex()’, which kills
          the thread without calling C++ destructors.

          In any case, there is a risk of corruption on the thread’s
          stack.

     Deprecato dalla versione 3.14.

 -- C Funzione: void PyThread_init_thread (void)
     ' Parte del *note ABI Stabile: 776.'  Initialize ‘PyThread*’ APIs.
     Python executes this function automatically, so there’s little need
     to call it from an extension module.

 -- C Funzione: int PyThread_set_stacksize (size_t size)
     ' Parte del *note ABI Stabile: 776.'  Set the stack size of the
     current thread to 'size' bytes.

     This function returns ‘0’ on success, ‘-1’ if 'size' is invalid, or
     ‘-2’ if the system does not support changing the stack size.  This
     function does not set exceptions.

     The caller does not need to hold an *note attached thread state:
     4eba.

 -- C Funzione: size_t PyThread_get_stacksize (void)
     ' Parte del *note ABI Stabile: 776.'  Return the stack size of the
     current thread in bytes, or ‘0’ if the system’s default stack size
     is in use.

     The caller does not need to hold an *note attached thread state:
     4eba.

   ---------- Footnotes ----------

   (1) https://manpages.debian.org/pthread_exit(3)


File: python.info,  Node: Python Initialization Configuration,  Next: Memory Management,  Prev: Initialization Finalization and Threads,  Up: Python/C API Reference Manual

7.11 Python Initialization Configuration
========================================

* Menu:

* PyInitConfig C API::
* Configuration Options::
* Runtime Python configuration API::
* PyConfig C API::
* Py_GetArgcArgv(): Py_GetArgcArgv.
* Delaying main module execution::


File: python.info,  Node: PyInitConfig C API,  Next: Configuration Options,  Up: Python Initialization Configuration

7.11.1 PyInitConfig C API
-------------------------

Added in version 3.14.

Python can be initialized with *note Py_InitializeFromInitConfig(): 386.

The *note Py_RunMain(): bbe. function can be used to write a customized
Python program.

See also *note Initialization, Finalization, and Threads: 54e7.

Vedi anche
..........

PEP 741(1) «Python Configuration C API».

* Menu:

* Example: Example<17>.
* Create Config::
* Error Handling::
* Get Options::
* Set Options::
* Module::
* Initialize Python::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0741/


File: python.info,  Node: Example<17>,  Next: Create Config,  Up: PyInitConfig C API

7.11.1.1 Example
................

Example of customized Python always running with the *note Python
Development Mode: 509. enabled; return ‘-1’ on error:

     int init_python(void)
     {
         PyInitConfig *config = PyInitConfig_Create();
         if (config == NULL) {
             printf("PYTHON INIT ERROR: memory allocation failed\n");
             return -1;
         }

         // Enable the Python Development Mode
         if (PyInitConfig_SetInt(config, "dev_mode", 1) < 0) {
             goto error;
         }

         // Initialize Python with the configuration
         if (Py_InitializeFromInitConfig(config) < 0) {
             goto error;
         }
         PyInitConfig_Free(config);
         return 0;

     error:
         {
             // Display the error message.
             //
             // This uncommon braces style is used, because you cannot make
             // goto targets point to variable declarations.
             const char *err_msg;
             (void)PyInitConfig_GetError(config, &err_msg);
             printf("PYTHON INIT ERROR: %s\n", err_msg);
             PyInitConfig_Free(config);
             return -1;
         }
     }


File: python.info,  Node: Create Config,  Next: Error Handling,  Prev: Example<17>,  Up: PyInitConfig C API

7.11.1.2 Create Config
......................

 -- C Struct: struct PyInitConfig

     Opaque structure to configure the Python initialization.

 -- C Funzione: *note PyInitConfig: 5544. *PyInitConfig_Create (void)

     Create a new initialization configuration using *note Isolated
     Configuration: 5545. default values.

     It must be freed by *note PyInitConfig_Free(): 388.

     Return ‘NULL’ on memory allocation failure.

 -- C Funzione: void PyInitConfig_Free (PyInitConfig *config)

     Free memory of the initialization configuration 'config'.

     If 'config' is ‘NULL’, no operation is performed.


File: python.info,  Node: Error Handling,  Next: Get Options,  Prev: Create Config,  Up: PyInitConfig C API

7.11.1.3 Error Handling
.......................

 -- C Funzione: int PyInitConfig_GetError (PyInitConfig *config, const
          char **err_msg)

     Get the 'config' error message.

        * Set '*err_msg' and return ‘1’ if an error is set.

        * Set '*err_msg' to ‘NULL’ and return ‘0’ otherwise.

     An error message is a UTF-8 encoded string.

     If 'config' has an exit code, format the exit code as an error
     message.

     The error message remains valid until another ‘PyInitConfig’
     function is called with 'config'.  The caller doesn’t have to free
     the error message.

 -- C Funzione: int PyInitConfig_GetExitCode (PyInitConfig *config, int
          *exitcode)

     Get the 'config' exit code.

        * Set '*exitcode' and return ‘1’ if 'config' has an exit code
          set.

        * Return ‘0’ if 'config' has no exit code set.

     Only the ‘Py_InitializeFromInitConfig()’ function can set an exit
     code if the ‘parse_argv’ option is non-zero.

     An exit code can be set when parsing the command line failed (exit
     code ‘2’) or when a command line option asks to display the command
     line help (exit code ‘0’).


File: python.info,  Node: Get Options,  Next: Set Options,  Prev: Error Handling,  Up: PyInitConfig C API

7.11.1.4 Get Options
....................

The configuration option 'name' parameter must be a non-NULL
null-terminated UTF-8 encoded string.  See *note Configuration Options:
5548.

 -- C Funzione: int PyInitConfig_HasOption (PyInitConfig *config, const
          char *name)

     Test if the configuration has an option called 'name'.

     Return ‘1’ if the option exists, or return ‘0’ otherwise.

 -- C Funzione: int PyInitConfig_GetInt (PyInitConfig *config, const
          char *name, int64_t *value)

     Get an integer configuration option.

        * Set '*value', and return ‘0’ on success.

        * Set an error in 'config' and return ‘-1’ on error.

 -- C Funzione: int PyInitConfig_GetStr (PyInitConfig *config, const
          char *name, char **value)

     Get a string configuration option as a null-terminated UTF-8
     encoded string.

        * Set '*value', and return ‘0’ on success.

        * Set an error in 'config' and return ‘-1’ on error.

     '*value' can be set to ‘NULL’ if the option is an optional string
     and the option is unset.

     On success, the string must be released with ‘free(value)’ if it’s
     not ‘NULL’.

 -- C Funzione: int PyInitConfig_GetStrList (PyInitConfig *config, const
          char *name, size_t *length, char ***items)

     Get a string list configuration option as an array of
     null-terminated UTF-8 encoded strings.

        * Set '*length' and '*value', and return ‘0’ on success.

        * Set an error in 'config' and return ‘-1’ on error.

     On success, the string list must be released with
     ‘PyInitConfig_FreeStrList(length, items)’.

 -- C Funzione: void PyInitConfig_FreeStrList (size_t length, char
          **items)

     Free memory of a string list created by
     ‘PyInitConfig_GetStrList()’.


File: python.info,  Node: Set Options,  Next: Module,  Prev: Get Options,  Up: PyInitConfig C API

7.11.1.5 Set Options
....................

The configuration option 'name' parameter must be a non-NULL
null-terminated UTF-8 encoded string.  See *note Configuration Options:
5548.

Some configuration options have side effects on other options.  This
logic is only implemented when ‘Py_InitializeFromInitConfig()’ is
called, not by the «Set» functions below.  For example, setting
‘dev_mode’ to ‘1’ does not set ‘faulthandler’ to ‘1’.

 -- C Funzione: int PyInitConfig_SetInt (PyInitConfig *config, const
          char *name, int64_t value)

     Set an integer configuration option.

        * Return ‘0’ on success.

        * Set an error in 'config' and return ‘-1’ on error.

 -- C Funzione: int PyInitConfig_SetStr (PyInitConfig *config, const
          char *name, const char *value)

     Set a string configuration option from a null-terminated UTF-8
     encoded string.  The string is copied.

        * Return ‘0’ on success.

        * Set an error in 'config' and return ‘-1’ on error.

 -- C Funzione: int PyInitConfig_SetStrList (PyInitConfig *config, const
          char *name, size_t length, char *const *items)

     Set a string list configuration option from an array of
     null-terminated UTF-8 encoded strings.  The string list is copied.

        * Return ‘0’ on success.

        * Set an error in 'config' and return ‘-1’ on error.


File: python.info,  Node: Module,  Next: Initialize Python,  Prev: Set Options,  Up: PyInitConfig C API

7.11.1.6 Module
...............

 -- C Funzione: int PyInitConfig_AddModule (PyInitConfig *config, const
          char *name, PyObject *(*initfunc)(void))

     Add a built-in extension module to the table of built-in modules.

     The new module can be imported by the name 'name', and uses the
     function 'initfunc' as the initialization function called on the
     first attempted import.

        * Return ‘0’ on success.

        * Set an error in 'config' and return ‘-1’ on error.

     If Python is initialized multiple times, ‘PyInitConfig_AddModule()’
     must be called at each Python initialization.

     Similar to the *note PyImport_AppendInittab(): 1b04. function.


File: python.info,  Node: Initialize Python,  Prev: Module,  Up: PyInitConfig C API

7.11.1.7 Initialize Python
..........................

 -- C Funzione: int Py_InitializeFromInitConfig (PyInitConfig *config)

     Initialize Python from the initialization configuration.

        * Return ‘0’ on success.

        * Set an error in 'config' and return ‘-1’ on error.

        * Set an exit code in 'config' and return ‘-1’ if Python wants
          to exit.

     See ‘PyInitConfig_GetExitcode()’ for the exit code case.


File: python.info,  Node: Configuration Options,  Next: Runtime Python configuration API,  Prev: PyInitConfig C API,  Up: Python Initialization Configuration

7.11.2 Configuration Options
----------------------------

Option                        PyConfig/PyPreConfig member   Type                          Visibility
                                                                                          
------------------------------------------------------------------------------------------------------------------------
                                                                                          
‘"allocator"’                 *note allocator: 554d.        ‘int’                         Read-only
                                                                                          
                                                                                          
‘"argv"’                      *note argv: 3f1.              ‘list[str]’                   Public
                                                                                          
                                                                                          
‘"base_exec_prefix"’          *note base_exec_prefix: 554e. ‘str’                         Public
                                                                                          
                                                                                          
‘"base_executable"’           *note base_executable: 554f.  ‘str’                         Public
                                                                                          
                                                                                          
‘"base_prefix"’               *note base_prefix: 5550.      ‘str’                         Public
                                                                                          
                                                                                          
‘"buffered_stdio"’            *note buffered_stdio: 411.    ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"bytes_warning"’             *note bytes_warning: 407.     ‘int’                         Public
                                                                                          
                                                                                          
‘"check_hash_pycs_mode"’      *note check_hash_pycs_mode: 5551.‘str’                      Read-only
                                                                                          
                                                                                          
‘"code_debug_ranges"’         *note code_debug_ranges: 5552.‘bool’                        Read-only
                                                                                          
                                                                                          
‘"coerce_c_locale"’           *note coerce_c_locale: 5553.  ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"coerce_c_locale_warn"’      *note coerce_c_locale_warn: 5554.‘bool’                     Read-only
                                                                                          
                                                                                          
‘"configure_c_stdio"’         *note configure_c_stdio: 5555.‘bool’                        Read-only
                                                                                          
                                                                                          
‘"configure_locale"’          *note configure_locale: 5556. ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"cpu_count"’                 *note cpu_count: 5557.        ‘int’                         Public
                                                                                          
                                                                                          
‘"dev_mode"’                  *note dev_mode: 5558.         ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"dump_refs"’                 *note dump_refs: 5559.        ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"dump_refs_file"’            *note dump_refs_file: 555a.   ‘str’                         Read-only
                                                                                          
                                                                                          
‘"exec_prefix"’               *note exec_prefix: 555b.      ‘str’                         Public
                                                                                          
                                                                                          
‘"executable"’                *note executable: 645.        ‘str’                         Public
                                                                                          
                                                                                          
‘"faulthandler"’              *note faulthandler: 555c.     ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"filesystem_encoding"’       *note filesystem_encoding: 41b.‘str’                        Read-only
                                                                                          
                                                                                          
‘"filesystem_errors"’         *note filesystem_errors: 41c. ‘str’                         Read-only
                                                                                          
                                                                                          
‘"hash_seed"’                 *note hash_seed: 414.         ‘int’                         Read-only
                                                                                          
                                                                                          
‘"home"’                      *note home: 3f3.              ‘str’                         Read-only
                                                                                          
                                                                                          
‘"import_time"’               *note import_time: 555d.      ‘int’                         Read-only
                                                                                          
                                                                                          
‘"inspect"’                   *note inspect: 401.           ‘bool’                        Public
                                                                                          
                                                                                          
‘"install_signal_handlers"’   *note install_signal_handlers: abd.‘bool’                   Read-only
                                                                                          
                                                                                          
‘"int_max_str_digits"’        *note int_max_str_digits: 555e.‘int’                        Public
                                                                                          
                                                                                          
‘"interactive"’               *note interactive: 3ff.       ‘bool’                        Public
                                                                                          
                                                                                          
‘"isolated"’                  *note isolated: 416.          ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"legacy_windows_fs_encoding"’*note legacy_windows_fs_encoding: 418.‘bool’                Read-only
                                                                                          
                                                                                          
‘"legacy_windows_stdio"’      *note legacy_windows_stdio: 41a.‘bool’                      Read-only
                                                                                          
                                                                                          
‘"malloc_stats"’              *note malloc_stats: 555f.     ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"module_search_paths"’       *note module_search_paths: 643.‘list[str]’                  Public
                                                                                          
                                                                                          
‘"optimization_level"’        *note optimization_level: 403.‘int’                         Public
                                                                                          
                                                                                          
‘"orig_argv"’                 *note orig_argv: a96.         ‘list[str]’                   Read-only
                                                                                          
                                                                                          
‘"parse_argv"’                *note parse_argv: 1cd9.       ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"parser_debug"’              *note parser_debug: 3f9.      ‘bool’                        Public
                                                                                          
                                                                                          
‘"pathconfig_warnings"’       *note pathconfig_warnings: 409.‘bool’                       Read-only
                                                                                          
                                                                                          
‘"perf_profiling"’            *note perf_profiling: 5560.   ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"platlibdir"’                *note platlibdir: 1d09.       ‘str’                         Public
                                                                                          
                                                                                          
‘"prefix"’                    *note prefix: 5561.           ‘str’                         Public
                                                                                          
                                                                                          
‘"program_name"’              *note program_name: 3f2.      ‘str’                         Read-only
                                                                                          
                                                                                          
‘"pycache_prefix"’            *note pycache_prefix: 5562.   ‘str’                         Public
                                                                                          
                                                                                          
‘"quiet"’                     *note quiet: 3fd.             ‘bool’                        Public
                                                                                          
                                                                                          
‘"run_command"’               *note run_command: 54f2.      ‘str’                         Read-only
                                                                                          
                                                                                          
‘"run_filename"’              *note run_filename: 54f3.     ‘str’                         Read-only
                                                                                          
                                                                                          
‘"run_module"’                *note run_module: 54f4.       ‘str’                         Read-only
                                                                                          
                                                                                          
‘"run_presite"’               *note run_presite: 5563.      ‘str’                         Read-only
                                                                                          
                                                                                          
‘"safe_path"’                 *note safe_path: 978.         ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"show_ref_count"’            *note show_ref_count: 5564.   ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"site_import"’               *note site_import: 405.       ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"skip_source_first_line"’    *note skip_source_first_line: 5565.‘bool’                   Read-only
                                                                                          
                                                                                          
‘"stdio_encoding"’            *note stdio_encoding: 644.    ‘str’                         Read-only
                                                                                          
                                                                                          
‘"stdio_errors"’              *note stdio_errors: 4910.     ‘str’                         Read-only
                                                                                          
                                                                                          
‘"stdlib_dir"’                *note stdlib_dir: 5566.       ‘str’                         Public
                                                                                          
                                                                                          
‘"tracemalloc"’               *note tracemalloc: 5567.      ‘int’                         Read-only
                                                                                          
                                                                                          
‘"use_environment"’           *note use_environment: 40b.   ‘bool’                        Public
                                                                                          
                                                                                          
‘"use_frozen_modules"’        *note use_frozen_modules: 5568.‘bool’                       Read-only
                                                                                          
                                                                                          
‘"use_hash_seed"’             *note use_hash_seed: 413.     ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"use_system_logger"’         *note use_system_logger: 225a.‘bool’                        Read-only
                                                                                          
                                                                                          
‘"user_site_directory"’       *note user_site_directory: 40f.‘bool’                       Read-only
                                                                                          
                                                                                          
‘"utf8_mode"’                 *note utf8_mode: 41d.         ‘bool’                        Read-only
                                                                                          
                                                                                          
‘"verbose"’                   *note verbose: 3fb.           ‘int’                         Public
                                                                                          
                                                                                          
‘"warn_default_encoding"’     *note warn_default_encoding: 5569.‘bool’                    Read-only
                                                                                          
                                                                                          
‘"warnoptions"’               *note warnoptions: 641.       ‘list[str]’                   Public
                                                                                          
                                                                                          
‘"write_bytecode"’            *note write_bytecode: 40d.    ‘bool’                        Public
                                                                                          
                                                                                          
‘"xoptions"’                  *note xoptions: 642.          ‘dict[str, str]’              Public
                                                                                          
                                                                                          
‘"_pystats"’                  *note _pystats: 556a.         ‘bool’                        Read-only
                                                                                          

Visibility:

   * Public: Can by get by *note PyConfig_Get(): 37c. and set by *note
     PyConfig_Set(): 37d.

   * Read-only: Can by get by *note PyConfig_Get(): 37c, but cannot be
     set by *note PyConfig_Set(): 37d.


File: python.info,  Node: Runtime Python configuration API,  Next: PyConfig C API,  Prev: Configuration Options,  Up: Python Initialization Configuration

7.11.3 Runtime Python configuration API
---------------------------------------

At runtime, it’s possible to get and set configuration options using
*note PyConfig_Get(): 37c. and *note PyConfig_Set(): 37d. functions.

The configuration option 'name' parameter must be a non-NULL
null-terminated UTF-8 encoded string.  See *note Configuration Options:
5548.

Some options are read from the *note sys: df. attributes.  For example,
the option ‘"argv"’ is read from *note sys.argv: 146c.

 -- C Funzione: *note PyObject: 5df. *PyConfig_Get (const char *name)

     Get the current runtime value of a configuration option as a Python
     object.

        * Return a new reference on success.

        * Set an exception and return ‘NULL’ on error.

     The object type depends on the configuration option.  It can be:

        * ‘bool’

        * ‘int’

        * ‘str’

        * ‘list[str]’

        * ‘dict[str, str]’

     The caller must have an *note attached thread state: 4eba.  The
     function cannot be called before Python initialization nor after
     Python finalization.

     Added in version 3.14.

 -- C Funzione: int PyConfig_GetInt (const char *name, int *value)

     Similar to *note PyConfig_Get(): 37c, but get the value as a C int.

        * Return ‘0’ on success.

        * Set an exception and return ‘-1’ on error.

     Added in version 3.14.

 -- C Funzione: *note PyObject: 5df. *PyConfig_Names (void)

     Get all configuration option names as a ‘frozenset’.

        * Return a new reference on success.

        * Set an exception and return ‘NULL’ on error.

     The caller must have an *note attached thread state: 4eba.  The
     function cannot be called before Python initialization nor after
     Python finalization.

     Added in version 3.14.

 -- C Funzione: int PyConfig_Set (const char *name, PyObject *value)

     Set the current runtime value of a configuration option.

        * Raise a *note ValueError: 2ec. if there is no option 'name'.

        * Raise a *note ValueError: 2ec. if 'value' is an invalid value.

        * Raise a *note ValueError: 2ec. if the option is read-only
          (cannot be set).

        * Raise a *note TypeError: 198. if 'value' has not the proper
          type.

     The caller must have an *note attached thread state: 4eba.  The
     function cannot be called before Python initialization nor after
     Python finalization.

     Raises an *note auditing event: 1c56. ‘cpython.PyConfig_Set’ with
     arguments ‘name’, ‘value’.

     Added in version 3.14.


File: python.info,  Node: PyConfig C API,  Next: Py_GetArgcArgv,  Prev: Runtime Python configuration API,  Up: Python Initialization Configuration

7.11.4 PyConfig C API
---------------------

Added in version 3.8.

Python can be initialized with *note Py_InitializeFromConfig(): 3f6. and
the *note PyConfig: 3f7. structure.  It can be preinitialized with *note
Py_PreInitialize(): 41e. and the *note PyPreConfig: ba5. structure.

There are two kinds of configuration:

   * The *note Python Configuration: 54f5. can be used to build a
     customized Python which behaves as the regular Python.  For
     example, environment variables and command line arguments are used
     to configure Python.

   * The *note Isolated Configuration: 5545. can be used to embed Python
     into an application.  It isolates Python from the system.  For
     example, environment variables are ignored, the LC_CTYPE locale is
     left unchanged and no signal handler is registered.

The *note Py_RunMain(): bbe. function can be used to write a customized
Python program.

See also *note Initialization, Finalization, and Threads: 54e7.

Vedi anche
..........

PEP 587(1) «Python Initialization Configuration».

* Menu:

* Example: Example<18>.
* PyWideStringList::
* PyStatus::
* PyPreConfig::
* Preinitialize Python with PyPreConfig::
* PyConfig::
* Initialization with PyConfig::
* Isolated Configuration::
* Python Configuration::
* Python Path Configuration::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0587/


File: python.info,  Node: Example<18>,  Next: PyWideStringList,  Up: PyConfig C API

7.11.4.1 Example
................

Example of customized Python always running in isolated mode:

     int main(int argc, char **argv)
     {
         PyStatus status;

         PyConfig config;
         PyConfig_InitPythonConfig(&config);
         config.isolated = 1;

         /* Decode command line arguments.
            Implicitly preinitialize Python (in isolated mode). */
         status = PyConfig_SetBytesArgv(&config, argc, argv);
         if (PyStatus_Exception(status)) {
             goto exception;
         }

         status = Py_InitializeFromConfig(&config);
         if (PyStatus_Exception(status)) {
             goto exception;
         }
         PyConfig_Clear(&config);

         return Py_RunMain();

     exception:
         PyConfig_Clear(&config);
         if (PyStatus_IsExit(status)) {
             return status.exitcode;
         }
         /* Display the error message and exit the process with
            non-zero exit code */
         Py_ExitStatusException(status);
     }


File: python.info,  Node: PyWideStringList,  Next: PyStatus,  Prev: Example<18>,  Up: PyConfig C API

7.11.4.2 PyWideStringList
.........................

 -- C Tipo: type PyWideStringList

     List of ‘wchar_t*’ strings.

     If 'length' is non-zero, 'items' must be non-‘NULL’ and all strings
     must be non-‘NULL’.

     Methods:

      -- C Funzione: *note PyStatus: ba6. PyWideStringList_Append
               (PyWideStringList *list, const wchar_t *item)

          Append 'item' to 'list'.

          Python must be preinitialized to call this function.

      -- C Funzione: *note PyStatus: ba6. PyWideStringList_Insert
               (PyWideStringList *list, Py_ssize_t index, const wchar_t
               *item)

          Insert 'item' into 'list' at 'index'.

          If 'index' is greater than or equal to 'list' length, append
          'item' to 'list'.

          'index' must be greater than or equal to ‘0’.

          Python must be preinitialized to call this function.

     Structure fields:

      -- C Membro: *note Py_ssize_t: c57. length

          List length.

      -- C Membro: wchar_t **items

          List items.


File: python.info,  Node: PyStatus,  Next: PyPreConfig,  Prev: PyWideStringList,  Up: PyConfig C API

7.11.4.3 PyStatus
.................

 -- C Tipo: type PyStatus

     Structure to store an initialization function status: success,
     error or exit.

     For an error, it can store the C function name which created the
     error.

     Structure fields:

      -- C Membro: int exitcode

          Exit code.  Argument passed to ‘exit()’.

      -- C Membro: const char *err_msg

          Error message.

      -- C Membro: const char *func

          Name of the function which created an error, can be ‘NULL’.

     Functions to create a status:

      -- C Funzione: *note PyStatus: ba6. PyStatus_Ok (void)

          Success.

      -- C Funzione: *note PyStatus: ba6. PyStatus_Error (const char
               *err_msg)

          Initialization error with a message.

          'err_msg' must not be ‘NULL’.

      -- C Funzione: *note PyStatus: ba6. PyStatus_NoMemory (void)

          Memory allocation failure (out of memory).

      -- C Funzione: *note PyStatus: ba6. PyStatus_Exit (int exitcode)

          Exit Python with the specified exit code.

     Functions to handle a status:

      -- C Funzione: int PyStatus_Exception (PyStatus status)

          Is the status an error or an exit?  If true, the exception
          must be handled; by calling *note Py_ExitStatusException():
          bbb. for example.

      -- C Funzione: int PyStatus_IsError (PyStatus status)

          Is the result an error?

      -- C Funzione: int PyStatus_IsExit (PyStatus status)

          Is the result an exit?

      -- C Funzione: void Py_ExitStatusException (PyStatus status)

          Call ‘exit(exitcode)’ if 'status' is an exit.  Print the error
          message and exit with a non-zero exit code if 'status' is an
          error.  Must only be called if ‘PyStatus_Exception(status)’ is
          non-zero.

     Nota: Internally, Python uses macros which set ‘PyStatus.func’,
     whereas functions to create a status set ‘func’ to ‘NULL’.

Example:

     PyStatus alloc(void **ptr, size_t size)
     {
         *ptr = PyMem_RawMalloc(size);
         if (*ptr == NULL) {
             return PyStatus_NoMemory();
         }
         return PyStatus_Ok();
     }

     int main(int argc, char **argv)
     {
         void *ptr;
         PyStatus status = alloc(&ptr, 16);
         if (PyStatus_Exception(status)) {
             Py_ExitStatusException(status);
         }
         PyMem_Free(ptr);
         return 0;
     }


File: python.info,  Node: PyPreConfig,  Next: Preinitialize Python with PyPreConfig,  Prev: PyStatus,  Up: PyConfig C API

7.11.4.4 PyPreConfig
....................

 -- C Tipo: type PyPreConfig

     Structure used to preinitialize Python.

     Function to initialize a preconfiguration:

      -- C Funzione: void PyPreConfig_InitPythonConfig (PyPreConfig
               *preconfig)

          Initialize the preconfiguration with *note Python
          Configuration: 54f5.

      -- C Funzione: void PyPreConfig_InitIsolatedConfig (PyPreConfig
               *preconfig)

          Initialize the preconfiguration with *note Isolated
          Configuration: 5545.

     Structure fields:

      -- C Membro: int allocator

          Name of the Python memory allocators:

             * ‘PYMEM_ALLOCATOR_NOT_SET’ (‘0’): don’t change memory
               allocators (use defaults).

             * ‘PYMEM_ALLOCATOR_DEFAULT’ (‘1’): *note default memory
               allocators: 2124.

             * ‘PYMEM_ALLOCATOR_DEBUG’ (‘2’): *note default memory
               allocators: 2124. with *note debug hooks: 2127.

             * ‘PYMEM_ALLOCATOR_MALLOC’ (‘3’): use ‘malloc()’ of the C
               library.

             * ‘PYMEM_ALLOCATOR_MALLOC_DEBUG’ (‘4’): force usage of
               ‘malloc()’ with *note debug hooks: 2127.

             * ‘PYMEM_ALLOCATOR_PYMALLOC’ (‘5’): *note Python pymalloc
               memory allocator: f0d.

             * ‘PYMEM_ALLOCATOR_PYMALLOC_DEBUG’ (‘6’): *note Python
               pymalloc memory allocator: f0d. with *note debug hooks:
               2127.

             * ‘PYMEM_ALLOCATOR_MIMALLOC’ (‘6’): use ‘mimalloc’, a fast
               malloc replacement.

             * ‘PYMEM_ALLOCATOR_MIMALLOC_DEBUG’ (‘7’): use ‘mimalloc’, a
               fast malloc replacement with *note debug hooks: 2127.

          ‘PYMEM_ALLOCATOR_PYMALLOC’ and
          ‘PYMEM_ALLOCATOR_PYMALLOC_DEBUG’ are not supported if Python
          is *note configured using -without-pymalloc: 218a.

          ‘PYMEM_ALLOCATOR_MIMALLOC’ and
          ‘PYMEM_ALLOCATOR_MIMALLOC_DEBUG’ are not supported if Python
          is *note configured using -without-mimalloc: 2189. or if the
          underlying atomic support isn’t available.

          See *note Memory Management: 5576.

          Default: ‘PYMEM_ALLOCATOR_NOT_SET’.

      -- C Membro: int configure_locale

          Set the LC_CTYPE locale to the user preferred locale.

          If equals to ‘0’, set *note coerce_c_locale: 5553. and *note
          coerce_c_locale_warn: 5554. members to ‘0’.

          See the *note locale encoding: 54b.

          Default: ‘1’ in Python config, ‘0’ in isolated config.

      -- C Membro: int coerce_c_locale

          If equals to ‘2’, coerce the C locale.

          If equals to ‘1’, read the LC_CTYPE locale to decide if it
          should be coerced.

          See the *note locale encoding: 54b.

          Default: ‘-1’ in Python config, ‘0’ in isolated config.

      -- C Membro: int coerce_c_locale_warn

          If non-zero, emit a warning if the C locale is coerced.

          Default: ‘-1’ in Python config, ‘0’ in isolated config.

      -- C Membro: int dev_mode

          *note Python Development Mode: 509.: see *note
          PyConfig.dev_mode: 5558.

          Default: ‘-1’ in Python mode, ‘0’ in isolated mode.

      -- C Membro: int isolated

          Isolated mode: see *note PyConfig.isolated: 416.

          Default: ‘0’ in Python mode, ‘1’ in isolated mode.

      -- C Membro: int legacy_windows_fs_encoding

          If non-zero:

             * Set *note PyPreConfig.utf8_mode: 41d. to ‘0’,

             * Set *note PyConfig.filesystem_encoding: 41b. to ‘"mbcs"’,

             * Set *note PyConfig.filesystem_errors: 41c. to
               ‘"replace"’.

          Initialized from the *note PYTHONLEGACYWINDOWSFSENCODING: 33f.
          environment variable value.

          Only available on Windows.  ‘#ifdef MS_WINDOWS’ macro can be
          used for Windows specific code.

          Default: ‘0’.

      -- C Membro: int parse_argv

          If non-zero, *note Py_PreInitializeFromArgs(): bbc. and *note
          Py_PreInitializeFromBytesArgs(): bbd. parse their ‘argv’
          argument the same way the regular Python parses command line
          arguments: see *note Command Line Arguments: 1209.

          Default: ‘1’ in Python config, ‘0’ in isolated config.

      -- C Membro: int use_environment

          Use *note environment variables: 808.?  See *note
          PyConfig.use_environment: 40b.

          Default: ‘1’ in Python config and ‘0’ in isolated config.

      -- C Membro: int utf8_mode

          If non-zero, enable the *note Python UTF-8 Mode: 867.

          Set to ‘0’ or ‘1’ by the *note -X utf8: 16f. command line
          option and the *note PYTHONUTF8: cd1. environment variable.

          Also set to ‘1’ if the ‘LC_CTYPE’ locale is ‘C’ or ‘POSIX’.

          Default: ‘-1’ in Python config and ‘0’ in isolated config.


File: python.info,  Node: Preinitialize Python with PyPreConfig,  Next: PyConfig,  Prev: PyPreConfig,  Up: PyConfig C API

7.11.4.5 Preinitialize Python with PyPreConfig
..............................................

The preinitialization of Python:

   * Set the Python memory allocators (*note PyPreConfig.allocator:
     554d.)

   * Configure the LC_CTYPE locale (*note locale encoding: 54b.)

   * Set the *note Python UTF-8 Mode: 867. (*note PyPreConfig.utf8_mode:
     41d.)

The current preconfiguration (‘PyPreConfig’ type) is stored in
‘_PyRuntime.preconfig’.

Functions to preinitialize Python:

 -- C Funzione: *note PyStatus: ba6. Py_PreInitialize (const PyPreConfig
          *preconfig)

     Preinitialize Python from 'preconfig' preconfiguration.

     'preconfig' must not be ‘NULL’.

 -- C Funzione: *note PyStatus: ba6. Py_PreInitializeFromBytesArgs
          (const PyPreConfig *preconfig, int argc, char *const *argv)

     Preinitialize Python from 'preconfig' preconfiguration.

     Parse 'argv' command line arguments (bytes strings) if *note
     parse_argv: 5579. of 'preconfig' is non-zero.

     'preconfig' must not be ‘NULL’.

 -- C Funzione: *note PyStatus: ba6. Py_PreInitializeFromArgs (const
          PyPreConfig *preconfig, int argc, wchar_t *const *argv)

     Preinitialize Python from 'preconfig' preconfiguration.

     Parse 'argv' command line arguments (wide strings) if *note
     parse_argv: 5579. of 'preconfig' is non-zero.

     'preconfig' must not be ‘NULL’.

The caller is responsible to handle exceptions (error or exit) using
*note PyStatus_Exception(): bb2. and *note Py_ExitStatusException():
bbb.

For *note Python Configuration: 54f5. (*note
PyPreConfig_InitPythonConfig(): bb0.), if Python is initialized with
command line arguments, the command line arguments must also be passed
to preinitialize Python, since they have an effect on the
pre-configuration like encodings.  For example, the *note -X utf8: 16f.
command line option enables the *note Python UTF-8 Mode: 867.

‘PyMem_SetAllocator()’ can be called after *note Py_PreInitialize():
41e. and before *note Py_InitializeFromConfig(): 3f6. to install a
custom memory allocator.  It can be called before *note
Py_PreInitialize(): 41e. if *note PyPreConfig.allocator: 554d. is set to
‘PYMEM_ALLOCATOR_NOT_SET’.

Python memory allocation functions like *note PyMem_RawMalloc(): 631.
must not be used before the Python preinitialization, whereas calling
directly ‘malloc()’ and ‘free()’ is always safe.  *note
Py_DecodeLocale(): dc2. must not be called before the Python
preinitialization.

Example using the preinitialization to enable the *note Python UTF-8
Mode: 867.:

     PyStatus status;
     PyPreConfig preconfig;
     PyPreConfig_InitPythonConfig(&preconfig);

     preconfig.utf8_mode = 1;

     status = Py_PreInitialize(&preconfig);
     if (PyStatus_Exception(status)) {
         Py_ExitStatusException(status);
     }

     /* at this point, Python speaks UTF-8 */

     Py_Initialize();
     /* ... use Python API here ... */
     Py_Finalize();


File: python.info,  Node: PyConfig,  Next: Initialization with PyConfig,  Prev: Preinitialize Python with PyPreConfig,  Up: PyConfig C API

7.11.4.6 PyConfig
.................

 -- C Tipo: type PyConfig

     Structure containing most parameters to configure Python.

     When done, the *note PyConfig_Clear(): ba8. function must be used
     to release the configuration memory.

     Structure methods:

      -- C Funzione: void PyConfig_InitPythonConfig (PyConfig *config)

          Initialize configuration with the *note Python Configuration:
          54f5.

      -- C Funzione: void PyConfig_InitIsolatedConfig (PyConfig *config)

          Initialize configuration with the *note Isolated
          Configuration: 5545.

      -- C Funzione: *note PyStatus: ba6. PyConfig_SetString (PyConfig
               *config, wchar_t *const *config_str, const wchar_t *str)

          Copy the wide character string 'str' into ‘*config_str’.

          *note Preinitialize Python: 42af. if needed.

      -- C Funzione: *note PyStatus: ba6. PyConfig_SetBytesString
               (PyConfig *config, wchar_t *const *config_str, const char
               *str)

          Decode 'str' using *note Py_DecodeLocale(): dc2. and set the
          result into ‘*config_str’.

          *note Preinitialize Python: 42af. if needed.

      -- C Funzione: *note PyStatus: ba6. PyConfig_SetArgv (PyConfig
               *config, int argc, wchar_t *const *argv)

          Set command line arguments (*note argv: 3f1. member of
          'config') from the 'argv' list of wide character strings.

          *note Preinitialize Python: 42af. if needed.

      -- C Funzione: *note PyStatus: ba6. PyConfig_SetBytesArgv
               (PyConfig *config, int argc, char *const *argv)

          Set command line arguments (*note argv: 3f1. member of
          'config') from the 'argv' list of bytes strings.  Decode bytes
          using *note Py_DecodeLocale(): dc2.

          *note Preinitialize Python: 42af. if needed.

      -- C Funzione: *note PyStatus: ba6. PyConfig_SetWideStringList
               (PyConfig *config, PyWideStringList *list, Py_ssize_t
               length, wchar_t **items)

          Set the list of wide strings 'list' to 'length' and 'items'.

          *note Preinitialize Python: 42af. if needed.

      -- C Funzione: *note PyStatus: ba6. PyConfig_Read (PyConfig
               *config)

          Read all Python configuration.

          Fields which are already initialized are left unchanged.

          Fields for *note path configuration: aac. are no longer
          calculated or modified when calling this function, as of
          Python 3.11.

          The *note PyConfig_Read(): 994. function only parses *note
          PyConfig.argv: 3f1. arguments once: *note PyConfig.parse_argv:
          1cd9. is set to ‘2’ after arguments are parsed.  Since Python
          arguments are stripped from *note PyConfig.argv: 3f1, parsing
          arguments twice would parse the application options as Python
          options.

          *note Preinitialize Python: 42af. if needed.

          Cambiato nella versione 3.10: The *note PyConfig.argv: 3f1.
          arguments are now only parsed once, *note PyConfig.parse_argv:
          1cd9. is set to ‘2’ after arguments are parsed, and arguments
          are only parsed if *note PyConfig.parse_argv: 1cd9. equals
          ‘1’.

          Cambiato nella versione 3.11: *note PyConfig_Read(): 994. no
          longer calculates all paths, and so fields listed under *note
          Python Path Configuration: aac. may no longer be updated until
          *note Py_InitializeFromConfig(): 3f6. is called.

      -- C Funzione: void PyConfig_Clear (PyConfig *config)

          Release configuration memory.

     Most ‘PyConfig’ methods *note preinitialize Python: 42af. if
     needed.  In that case, the Python preinitialization configuration
     (*note PyPreConfig: ba5.) in based on the *note PyConfig: 3f7.  If
     configuration fields which are in common with *note PyPreConfig:
     ba5. are tuned, they must be set before calling a *note PyConfig:
     3f7. method:

        * *note PyConfig.dev_mode: 5558.

        * *note PyConfig.isolated: 416.

        * *note PyConfig.parse_argv: 1cd9.

        * *note PyConfig.use_environment: 40b.

     Moreover, if *note PyConfig_SetArgv(): bab. or *note
     PyConfig_SetBytesArgv(): bac. is used, this method must be called
     before other methods, since the preinitialization configuration
     depends on command line arguments (if *note parse_argv: 1cd9. is
     non-zero).

     The caller of these methods is responsible to handle exceptions
     (error or exit) using ‘PyStatus_Exception()’ and
     ‘Py_ExitStatusException()’.

     Structure fields:

      -- C Membro: *note PyWideStringList: ba7. argv

          Set *note sys.argv: 146c. command line arguments based on
          *note argv: 3f1.  These parameters are similar to those passed
          to the program’s ‘main()’ function with the difference that
          the first entry should refer to the script file to be executed
          rather than the executable hosting the Python interpreter.  If
          there isn’t a script that will be run, the first entry in
          *note argv: 3f1. can be an empty string.

          Set *note parse_argv: 1cd9. to ‘1’ to parse *note argv: 3f1.
          the same way the regular Python parses Python command line
          arguments and then to strip Python arguments from *note argv:
          3f1.

          If *note argv: 3f1. is empty, an empty string is added to
          ensure that *note sys.argv: 146c. always exists and is never
          empty.

          Default: ‘NULL’.

          See also the *note orig_argv: a96. member.

      -- C Membro: int safe_path

          If equals to zero, ‘Py_RunMain()’ prepends a potentially
          unsafe path to *note sys.path: 3e4. at startup:

             * If *note argv[0]: 3f1. is equal to ‘L"-m"’ (‘python -m
               module’), prepend the current working directory.

             * If running a script (‘python script.py’), prepend the
               script’s directory.  If it’s a symbolic link, resolve
               symbolic links.

             * Otherwise (‘python -c code’ and ‘python’), prepend an
               empty string, which means the current working directory.

          Set to ‘1’ by the *note -P: 7c2. command line option and the
          *note PYTHONSAFEPATH: 7c3. environment variable.

          Default: ‘0’ in Python config, ‘1’ in isolated config.

          Added in version 3.11.

      -- C Membro: wchar_t *base_exec_prefix

          *note sys.base_exec_prefix: 3ea.

          Default: ‘NULL’.

          Part of the *note Python Path Configuration: aac. output.

          See also *note PyConfig.exec_prefix: 555b.

      -- C Membro: wchar_t *base_executable

          Python base executable: ‘sys._base_executable’.

          Set by the ‘__PYVENV_LAUNCHER__’ environment variable.

          Set from *note PyConfig.executable: 645. if ‘NULL’.

          Default: ‘NULL’.

          Part of the *note Python Path Configuration: aac. output.

          See also *note PyConfig.executable: 645.

      -- C Membro: wchar_t *base_prefix

          *note sys.base_prefix: 3e6.

          Default: ‘NULL’.

          Part of the *note Python Path Configuration: aac. output.

          See also *note PyConfig.prefix: 5561.

      -- C Membro: int buffered_stdio

          If equals to ‘0’ and *note configure_c_stdio: 5555. is
          non-zero, disable buffering on the C streams stdout and
          stderr.

          Set to ‘0’ by the *note -u: 1d75. command line option and the
          *note PYTHONUNBUFFERED: 1d76. environment variable.

          stdin is always opened in buffered mode.

          Default: ‘1’.

      -- C Membro: int bytes_warning

          If equals to ‘1’, issue a warning when comparing *note bytes:
          192. or *note bytearray: 344. with *note str: 169, or
          comparing *note bytes: 192. with *note int: 19b.

          If equal or greater to ‘2’, raise a *note BytesWarning: e1e.
          exception in these cases.

          Incremented by the *note -b: 7fa. command line option.

          Default: ‘0’.

      -- C Membro: int warn_default_encoding

          If non-zero, emit a *note EncodingWarning: 2117. warning when
          *note io.TextIOWrapper: 9c0. uses its default encoding.  See
          *note Opt-in EncodingWarning: 2129. for details.

          Default: ‘0’.

          Added in version 3.10.

      -- C Membro: int code_debug_ranges

          If equals to ‘0’, disables the inclusion of the end line and
          column mappings in code objects.  Also disables traceback
          printing carets to specific error locations.

          Set to ‘0’ by the *note PYTHONNODEBUGRANGES: 7d4. environment
          variable and by the *note -X no_debug_ranges: 16f. command
          line option.

          Default: ‘1’.

          Added in version 3.11.

      -- C Membro: wchar_t *check_hash_pycs_mode

          Control the validation behavior of hash-based ‘.pyc’ files:
          value of the *note -check-hash-based-pycs: 210b. command line
          option.

          Valid values:

             - ‘L"always"’: Hash the source file for invalidation
               regardless of value of the “check_source” flag.

             - ‘L"never"’: Assume that hash-based pycs always are valid.

             - ‘L"default"’: The “check_source” flag in hash-based pycs
               determines invalidation.

          Default: ‘L"default"’.

          See also PEP 552(1) «Deterministic pycs».

      -- C Membro: int configure_c_stdio

          If non-zero, configure C standard streams:

             * On Windows, set the binary mode (‘O_BINARY’) on stdin,
               stdout and stderr.

             * If *note buffered_stdio: 411. equals zero, disable
               buffering of stdin, stdout and stderr streams.

             * If *note interactive: 3ff. is non-zero, enable stream
               buffering on stdin and stdout (only stdout on Windows).

          Default: ‘1’ in Python config, ‘0’ in isolated config.

      -- C Membro: int dev_mode

          If non-zero, enable the *note Python Development Mode: 509.

          Set to ‘1’ by the *note -X dev: 16f. option and the *note
          PYTHONDEVMODE: ce9. environment variable.

          Default: ‘-1’ in Python mode, ‘0’ in isolated mode.

      -- C Membro: int dump_refs

          Dump Python references?

          If non-zero, dump all objects which are still alive at exit.

          Set to ‘1’ by the *note PYTHONDUMPREFS: ba0. environment
          variable.

          Needs a special build of Python with the ‘Py_TRACE_REFS’ macro
          defined: see the *note configure -with-trace-refs option: 636.

          Default: ‘0’.

      -- C Membro: wchar_t *dump_refs_file

          Filename where to dump Python references.

          Set by the *note PYTHONDUMPREFSFILE: 1c27. environment
          variable.

          Default: ‘NULL’.

          Added in version 3.11.

      -- C Membro: wchar_t *exec_prefix

          The site-specific directory prefix where the
          platform-dependent Python files are installed: *note
          sys.exec_prefix: 3eb.

          Default: ‘NULL’.

          Part of the *note Python Path Configuration: aac. output.

          See also *note PyConfig.base_exec_prefix: 554e.

      -- C Membro: wchar_t *executable

          The absolute path of the executable binary for the Python
          interpreter: *note sys.executable: 3ed.

          Default: ‘NULL’.

          Part of the *note Python Path Configuration: aac. output.

          See also *note PyConfig.base_executable: 554f.

      -- C Membro: int faulthandler

          Enable faulthandler?

          If non-zero, call *note faulthandler.enable(): 20f. at
          startup.

          Set to ‘1’ by *note -X faulthandler: 16f. and the *note
          PYTHONFAULTHANDLER: 1287. environment variable.

          Default: ‘-1’ in Python mode, ‘0’ in isolated mode.

      -- C Membro: wchar_t *filesystem_encoding

          *note Filesystem encoding: 75e.: *note
          sys.getfilesystemencoding(): e55.

          On macOS, Android and VxWorks: use ‘"utf-8"’ by default.

          On Windows: use ‘"utf-8"’ by default, or ‘"mbcs"’ if *note
          legacy_windows_fs_encoding: 418. of *note PyPreConfig: ba5. is
          non-zero.

          Default encoding on other platforms:

             * ‘"utf-8"’ if *note PyPreConfig.utf8_mode: 41d. is
               non-zero.

             * ‘"ascii"’ if Python detects that ‘nl_langinfo(CODESET)’
               announces the ASCII encoding, whereas the ‘mbstowcs()’
               function decodes from a different encoding (usually
               Latin1).

             * ‘"utf-8"’ if ‘nl_langinfo(CODESET)’ returns an empty
               string.

             * Otherwise, use the *note locale encoding: 54b.:
               ‘nl_langinfo(CODESET)’ result.

          At Python startup, the encoding name is normalized to the
          Python codec name.  For example, ‘"ANSI_X3.4-1968"’ is
          replaced with ‘"ascii"’.

          See also the *note filesystem_errors: 41c. member.

      -- C Membro: wchar_t *filesystem_errors

          *note Filesystem error handler: 75e.: *note
          sys.getfilesystemencodeerrors(): ee4.

          On Windows: use ‘"surrogatepass"’ by default, or ‘"replace"’
          if *note legacy_windows_fs_encoding: 418. of *note
          PyPreConfig: ba5. is non-zero.

          On other platforms: use ‘"surrogateescape"’ by default.

          Supported error handlers:

             * ‘"strict"’

             * ‘"surrogateescape"’

             * ‘"surrogatepass"’ (only supported with the UTF-8
               encoding)

          See also the *note filesystem_encoding: 41b. member.

      -- C Membro: int use_frozen_modules

          If non-zero, use frozen modules.

          Set by the *note PYTHON_FROZEN_MODULES: 4ae. environment
          variable.

          Default: ‘1’ in a release build, or ‘0’ in a *note debug
          build: 50a.

      -- C Membro: unsigned long hash_seed

      -- C Membro: int use_hash_seed

          Randomized hash function seed.

          If *note use_hash_seed: 413. is zero, a seed is chosen
          randomly at Python startup, and *note hash_seed: 414. is
          ignored.

          Set by the *note PYTHONHASHSEED: 127f. environment variable.

          Default 'use_hash_seed' value: ‘-1’ in Python mode, ‘0’ in
          isolated mode.

      -- C Membro: wchar_t *home

          Set the default Python «home» directory, that is, the location
          of the standard Python libraries (see *note PYTHONHOME: 3f0.).

          Set by the *note PYTHONHOME: 3f0. environment variable.

          Default: ‘NULL’.

          Part of the *note Python Path Configuration: aac. input.

      -- C Membro: int import_time

               If ‘1’, profile import time.  If ‘2’, include additional
               output that indicates when an imported module has already
               been loaded.

               Set by the *note -X importtime: 16f. option and the *note
               PYTHONPROFILEIMPORTTIME: cef. environment variable.

               Default: ‘0’.

          Cambiato nella versione 3.14: Added support for ‘import_time =
          2’

      -- C Membro: int inspect

          Enter interactive mode after executing a script or a command.

          If greater than ‘0’, enable inspect: when a script is passed
          as first argument or the -c option is used, enter interactive
          mode after executing the script or the command, even when
          *note sys.stdin: 760. does not appear to be a terminal.

          Incremented by the *note -i: 16e2. command line option.  Set
          to ‘1’ if the *note PYTHONINSPECT: 16e1. environment variable
          is non-empty.

          Default: ‘0’.

      -- C Membro: int install_signal_handlers

          Install Python signal handlers?

          Default: ‘1’ in Python mode, ‘0’ in isolated mode.

      -- C Membro: int interactive

          If greater than ‘0’, enable the interactive mode (REPL).

          Incremented by the *note -i: 16e2. command line option.

          Default: ‘0’.

      -- C Membro: int int_max_str_digits

          Configures the *note integer string conversion length
          limitation: 80c.  An initial value of ‘-1’ means the value
          will be taken from the command line or environment or
          otherwise default to 4300 (*note
          sys.int_info.default_max_str_digits: 26bf.).  A value of ‘0’
          disables the limitation.  Values greater than zero but less
          than 640 (*note sys.int_info.str_digits_check_threshold:
          490d.) are unsupported and will produce an error.

          Configured by the *note -X int_max_str_digits: 16f. command
          line flag or the *note PYTHONINTMAXSTRDIGITS: 1b22.
          environment variable.

          Default: ‘-1’ in Python mode.  4300 (*note
          sys.int_info.default_max_str_digits: 26bf.) in isolated mode.

          Added in version 3.12.

      -- C Membro: int cpu_count

          If the value of *note cpu_count: 5557. is not ‘-1’ then it
          will override the return values of *note os.cpu_count(): 4dc,
          *note os.process_cpu_count(): 4db, and *note
          multiprocessing.cpu_count(): 1171.

          Configured by the ‘-X cpu_count=N|DEFAULT’ command line flag
          or the *note PYTHON_CPU_COUNT: 51f. environment variable.

          Default: ‘-1’.

          Added in version 3.13.

      -- C Membro: int isolated

          If greater than ‘0’, enable isolated mode:

             * Set *note safe_path: 978. to ‘1’: don’t prepend a
               potentially unsafe path to *note sys.path: 3e4. at Python
               startup, such as the current directory, the script’s
               directory or an empty string.

             * Set *note use_environment: 40b. to ‘0’: ignore ‘PYTHON’
               environment variables.

             * Set *note user_site_directory: 40f. to ‘0’: don’t add the
               user site directory to *note sys.path: 3e4.

             * Python REPL doesn’t import *note readline: bf. nor enable
               default readline configuration on interactive prompts.

          Set to ‘1’ by the *note -I: b59. command line option.

          Default: ‘0’ in Python mode, ‘1’ in isolated mode.

          See also the *note Isolated Configuration: 5545. and *note
          PyPreConfig.isolated: 5578.

      -- C Membro: int legacy_windows_stdio

          If non-zero, use *note io.FileIO: 1517. instead of
          ‘io._WindowsConsoleIO’ for *note sys.stdin: 760, *note
          sys.stdout: ccf. and *note sys.stderr: b35.

          Set to ‘1’ if the *note PYTHONLEGACYWINDOWSSTDIO: e57.
          environment variable is set to a non-empty string.

          Only available on Windows.  ‘#ifdef MS_WINDOWS’ macro can be
          used for Windows specific code.

          Default: ‘0’.

          See also the PEP 528(2) (Change Windows console encoding to
          UTF-8).

      -- C Membro: int malloc_stats

          If non-zero, dump statistics on *note Python pymalloc memory
          allocator: f0d. at exit.

          Set to ‘1’ by the *note PYTHONMALLOCSTATS: 1f1f. environment
          variable.

          The option is ignored if Python is *note configured using the
          -without-pymalloc option: 218a.

          Default: ‘0’.

      -- C Membro: wchar_t *platlibdir

          Platform library directory name: *note sys.platlibdir: b34.

          Set by the *note PYTHONPLATLIBDIR: 1d0b. environment variable.

          Default: value of the ‘PLATLIBDIR’ macro which is set by the
          *note configure -with-platlibdir option: 2155. (default:
          ‘"lib"’, or ‘"DLLs"’ on Windows).

          Part of the *note Python Path Configuration: aac. input.

          Added in version 3.9.

          Cambiato nella versione 3.11: This macro is now used on
          Windows to locate the standard library extension modules,
          typically under ‘DLLs’.  However, for compatibility, note that
          this value is ignored for any non-standard layouts, including
          in-tree builds and virtual environments.

      -- C Membro: wchar_t *pythonpath_env

          Module search paths (*note sys.path: 3e4.) as a string
          separated by ‘DELIM’ (*note os.pathsep: 211d.).

          Set by the *note PYTHONPATH: 121f. environment variable.

          Default: ‘NULL’.

          Part of the *note Python Path Configuration: aac. input.

      -- C Membro: *note PyWideStringList: ba7. module_search_paths

      -- C Membro: int module_search_paths_set

          Module search paths: *note sys.path: 3e4.

          If *note module_search_paths_set: 806. is equal to ‘0’, *note
          Py_InitializeFromConfig(): 3f6. will replace *note
          module_search_paths: 643. and sets *note
          module_search_paths_set: 806. to ‘1’.

          Default: empty list (‘module_search_paths’) and ‘0’
          (‘module_search_paths_set’).

          Part of the *note Python Path Configuration: aac. output.

      -- C Membro: int optimization_level

          Compilation optimization level:

             * ‘0’: Peephole optimizer, set ‘__debug__’ to ‘True’.

             * ‘1’: Level 0, remove assertions, set ‘__debug__’ to
               ‘False’.

             * ‘2’: Level 1, strip docstrings.

          Incremented by the *note -O: 18c. command line option.  Set to
          the *note PYTHONOPTIMIZE: 210e. environment variable value.

          Default: ‘0’.

      -- C Membro: *note PyWideStringList: ba7. orig_argv

          The list of the original command line arguments passed to the
          Python executable: *note sys.orig_argv: a43.

          If *note orig_argv: a96. list is empty and *note argv: 3f1. is
          not a list only containing an empty string, *note
          PyConfig_Read(): 994. copies *note argv: 3f1. into *note
          orig_argv: a96. before modifying *note argv: 3f1. (if *note
          parse_argv: 1cd9. is non-zero).

          See also the *note argv: 3f1. member and the *note
          Py_GetArgcArgv(): 1d29. function.

          Default: empty list.

          Added in version 3.10.

      -- C Membro: int parse_argv

          Parse command line arguments?

          If equals to ‘1’, parse *note argv: 3f1. the same way the
          regular Python parses *note command line arguments: 1209, and
          strip Python arguments from *note argv: 3f1.

          The *note PyConfig_Read(): 994. function only parses *note
          PyConfig.argv: 3f1. arguments once: *note PyConfig.parse_argv:
          1cd9. is set to ‘2’ after arguments are parsed.  Since Python
          arguments are stripped from *note PyConfig.argv: 3f1, parsing
          arguments twice would parse the application options as Python
          options.

          Default: ‘1’ in Python mode, ‘0’ in isolated mode.

          Cambiato nella versione 3.10: The *note PyConfig.argv: 3f1.
          arguments are now only parsed if *note PyConfig.parse_argv:
          1cd9. equals to ‘1’.

      -- C Membro: int parser_debug

          Parser debug mode.  If greater than ‘0’, turn on parser
          debugging output (for expert only, depending on compilation
          options).

          Incremented by the *note -d: 210c. command line option.  Set
          to the *note PYTHONDEBUG: 210d. environment variable value.

          Needs a *note debug build of Python: 50a. (the ‘Py_DEBUG’
          macro must be defined).

          Default: ‘0’.

      -- C Membro: int pathconfig_warnings

          If non-zero, calculation of path configuration is allowed to
          log warnings into ‘stderr’.  If equals to ‘0’, suppress these
          warnings.

          Default: ‘1’ in Python mode, ‘0’ in isolated mode.

          Part of the *note Python Path Configuration: aac. input.

          Cambiato nella versione 3.11: Now also applies on Windows.

      -- C Membro: wchar_t *prefix

          The site-specific directory prefix where the platform
          independent Python files are installed: *note sys.prefix: 3e7.

          Default: ‘NULL’.

          Part of the *note Python Path Configuration: aac. output.

          See also *note PyConfig.base_prefix: 5550.

      -- C Membro: wchar_t *program_name

          Program name used to initialize *note executable: 645. and in
          early error messages during Python initialization.

             * On macOS, use *note PYTHONEXECUTABLE: 2121. environment
               variable if set.

             * If the ‘WITH_NEXT_FRAMEWORK’ macro is defined, use
               ‘__PYVENV_LAUNCHER__’ environment variable if set.

             * Use ‘argv[0]’ of *note argv: 3f1. if available and
               non-empty.

             * Otherwise, use ‘L"python"’ on Windows, or ‘L"python3"’ on
               other platforms.

          Default: ‘NULL’.

          Part of the *note Python Path Configuration: aac. input.

      -- C Membro: wchar_t *pycache_prefix

          Directory where cached ‘.pyc’ files are written: *note
          sys.pycache_prefix: b9e.

          Set by the *note -X pycache_prefix=PATH: 16f. command line
          option and the *note PYTHONPYCACHEPREFIX: b9d. environment
          variable.  The command-line option takes precedence.

          If ‘NULL’, *note sys.pycache_prefix: b9e. is set to ‘None’.

          Default: ‘NULL’.

      -- C Membro: int quiet

          Quiet mode.  If greater than ‘0’, don’t display the copyright
          and version at Python startup in interactive mode.

          Incremented by the *note -q: 1765. command line option.

          Default: ‘0’.

      -- C Membro: wchar_t *run_command

          Value of the *note -c: 1a8. command line option.

          Used by *note Py_RunMain(): bbe.

          Default: ‘NULL’.

      -- C Membro: wchar_t *run_filename

          Filename passed on the command line: trailing command line
          argument without *note -c: 1a8. or *note -m: 23c.  It is used
          by the *note Py_RunMain(): bbe. function.

          For example, it is set to ‘script.py’ by the ‘python3
          script.py arg’ command line.

          See also the *note PyConfig.skip_source_first_line: 5565.
          option.

          Default: ‘NULL’.

      -- C Membro: wchar_t *run_module

          Value of the *note -m: 23c. command line option.

          Used by *note Py_RunMain(): bbe.

          Default: ‘NULL’.

      -- C Membro: wchar_t *run_presite

          ‘package.module’ path to module that should be imported before
          ‘site.py’ is run.

          Set by the *note -X presite=package.module: 16f. command-line
          option and the *note PYTHON_PRESITE: 2118. environment
          variable.  The command-line option takes precedence.

          Needs a *note debug build of Python: 50a. (the ‘Py_DEBUG’
          macro must be defined).

          Default: ‘NULL’.

      -- C Membro: int show_ref_count

          Show total reference count at exit (excluding *note immortal:
          290. objects)?

          Set to ‘1’ by *note -X showrefcount: 16f. command line option.

          Needs a *note debug build of Python: 50a. (the ‘Py_REF_DEBUG’
          macro must be defined).

          Default: ‘0’.

      -- C Membro: int site_import

          Import the *note site: cc. module at startup?

          If equal to zero, disable the import of the module site and
          the site-dependent manipulations of *note sys.path: 3e4. that
          it entails.

          Also disable these manipulations if the *note site: cc. module
          is explicitly imported later (call *note site.main(): 2110. if
          you want them to be triggered).

          Set to ‘0’ by the *note -S: 13b0. command line option.

          *note sys.flags.no_site: 89d. is set to the inverted value of
          *note site_import: 405.

          Default: ‘1’.

      -- C Membro: int skip_source_first_line

          If non-zero, skip the first line of the *note
          PyConfig.run_filename: 54f3. source.

          It allows the usage of non-Unix forms of ‘#!cmd’.  This is
          intended for a DOS specific hack only.

          Set to ‘1’ by the *note -x: 2114. command line option.

          Default: ‘0’.

      -- C Membro: wchar_t *stdio_encoding

      -- C Membro: wchar_t *stdio_errors

          Encoding and encoding errors of *note sys.stdin: 760, *note
          sys.stdout: ccf. and *note sys.stderr: b35. (but *note
          sys.stderr: b35. always uses ‘"backslashreplace"’ error
          handler).

          Use the *note PYTHONIOENCODING: 120c. environment variable if
          it is non-empty.

          Default encoding:

             * ‘"UTF-8"’ if *note PyPreConfig.utf8_mode: 41d. is
               non-zero.

             * Otherwise, use the *note locale encoding: 54b.

          Default error handler:

             * On Windows: use ‘"surrogateescape"’.

             * ‘"surrogateescape"’ if *note PyPreConfig.utf8_mode: 41d.
               is non-zero, or if the LC_CTYPE locale is «C» or «POSIX».

             * ‘"strict"’ otherwise.

          See also *note PyConfig.legacy_windows_stdio: 41a.

      -- C Membro: int tracemalloc

          Enable tracemalloc?

          If non-zero, call *note tracemalloc.start(): 2115. at startup.

          Set by *note -X tracemalloc=N: 16f. command line option and by
          the *note PYTHONTRACEMALLOC: 2116. environment variable.

          Default: ‘-1’ in Python mode, ‘0’ in isolated mode.

      -- C Membro: int perf_profiling

          Enable the Linux ‘perf’ profiler support?

          If equals to ‘1’, enable support for the Linux ‘perf’
          profiler.

          If equals to ‘2’, enable support for the Linux ‘perf’ profiler
          with DWARF JIT support.

          Set to ‘1’ by *note -X perf: 16f. command-line option and the
          *note PYTHONPERFSUPPORT: 69a. environment variable.

          Set to ‘2’ by the *note -X perf_jit: 16f. command-line option
          and the *note PYTHON_PERF_JIT_SUPPORT: 4b0. environment
          variable.

          Default: ‘-1’.

          Vedi anche
          ..........

          See *note Python support for the Linux perf profiler: 4af. for
          more information.

          Added in version 3.12.

      -- C Membro: wchar_t *stdlib_dir

          Directory of the Python standard library.

          Default: ‘NULL’.

          Added in version 3.11.

      -- C Membro: int use_environment

          Use *note environment variables: 808.?

          If equals to zero, ignore the *note environment variables:
          808.

          Set to ‘0’ by the *note -E: b58. environment variable.

          Default: ‘1’ in Python config and ‘0’ in isolated config.

      -- C Membro: int use_system_logger

          If non-zero, ‘stdout’ and ‘stderr’ will be redirected to the
          system log.

          Only available on macOS 10.12 and later, and on iOS.

          Default: ‘0’ (don’t use the system log) on macOS; ‘1’ on iOS
          (use the system log).

          Added in version 3.14.

      -- C Membro: int user_site_directory

          If non-zero, add the user site directory to *note sys.path:
          3e4.

          Set to ‘0’ by the *note -s: 1596. and *note -I: b59. command
          line options.

          Set to ‘0’ by the *note PYTHONNOUSERSITE: 1597. environment
          variable.

          Default: ‘1’ in Python mode, ‘0’ in isolated mode.

      -- C Membro: int verbose

          Verbose mode.  If greater than ‘0’, print a message each time
          a module is imported, showing the place (filename or built-in
          module) from which it is loaded.

          If greater than or equal to ‘2’, print a message for each file
          that is checked for when searching for a module.  Also
          provides information on module cleanup at exit.

          Incremented by the *note -v: 162c. command line option.

          Set by the *note PYTHONVERBOSE: 2111. environment variable
          value.

          Default: ‘0’.

      -- C Membro: *note PyWideStringList: ba7. warnoptions

          Options of the *note warnings: 118. module to build warnings
          filters, lowest to highest priority: *note sys.warnoptions:
          3f5.

          The *note warnings: 118. module adds *note sys.warnoptions:
          3f5. in the reverse order: the last *note
          PyConfig.warnoptions: 641. item becomes the first item of
          ‘warnings.filters’ which is checked first (highest priority).

          The *note -W: ac7. command line options adds its value to
          *note warnoptions: 641, it can be used multiple times.

          The *note PYTHONWARNINGS: da5. environment variable can also
          be used to add warning options.  Multiple options can be
          specified, separated by commas (‘,’).

          Default: empty list.

      -- C Membro: int write_bytecode

          If equal to ‘0’, Python won’t try to write ‘.pyc’ files on the
          import of source modules.

          Set to ‘0’ by the *note -B: 15d4. command line option and the
          *note PYTHONDONTWRITEBYTECODE: 15d5. environment variable.

          *note sys.dont_write_bytecode: 48d9. is initialized to the
          inverted value of *note write_bytecode: 40d.

          Default: ‘1’.

      -- C Membro: *note PyWideStringList: ba7. xoptions

          Values of the *note -X: 16f. command line options: *note
          sys._xoptions: 211a.

          Default: empty list.

      -- C Membro: int _pystats

          If non-zero, write performance statistics at Python exit.

          Need a special build with the ‘Py_STATS’ macro: see *note
          -enable-pystats: 1b20.

          Default: ‘0’.

If *note parse_argv: 1cd9. is non-zero, *note argv: 3f1. arguments are
parsed the same way the regular Python parses *note command line
arguments: 1209, and Python arguments are stripped from *note argv: 3f1.

The *note xoptions: 642. options are parsed to set other options: see
the *note -X: 16f. command line option.

Cambiato nella versione 3.9: The ‘show_alloc_count’ field has been
removed.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0552/

   (2) https://peps.python.org/pep-0528/


File: python.info,  Node: Initialization with PyConfig,  Next: Isolated Configuration,  Prev: PyConfig,  Up: PyConfig C API

7.11.4.7 Initialization with PyConfig
.....................................

Initializing the interpreter from a populated configuration struct is
handled by calling *note Py_InitializeFromConfig(): 3f6.

The caller is responsible to handle exceptions (error or exit) using
*note PyStatus_Exception(): bb2. and *note Py_ExitStatusException():
bbb.

If *note PyImport_FrozenModules(): 32fe, *note PyImport_AppendInittab():
1b04. or *note PyImport_ExtendInittab(): 1b05. are used, they must be
set or called after Python preinitialization and before the Python
initialization.  If Python is initialized multiple times, *note
PyImport_AppendInittab(): 1b04. or *note PyImport_ExtendInittab(): 1b05.
must be called before each Python initialization.

The current configuration (‘PyConfig’ type) is stored in
‘PyInterpreterState.config’.

Example setting the program name:

     void init_python(void)
     {
         PyStatus status;

         PyConfig config;
         PyConfig_InitPythonConfig(&config);

         /* Set the program name. Implicitly preinitialize Python. */
         status = PyConfig_SetString(&config, &config.program_name,
                                     L"/path/to/my_program");
         if (PyStatus_Exception(status)) {
             goto exception;
         }

         status = Py_InitializeFromConfig(&config);
         if (PyStatus_Exception(status)) {
             goto exception;
         }
         PyConfig_Clear(&config);
         return;

     exception:
         PyConfig_Clear(&config);
         Py_ExitStatusException(status);
     }

More complete example modifying the default configuration, read the
configuration, and then override some parameters.  Note that since 3.11,
many parameters are not calculated until initialization, and so values
cannot be read from the configuration structure.  Any values set before
initialize is called will be left unchanged by initialization:

     PyStatus init_python(const char *program_name)
     {
         PyStatus status;

         PyConfig config;
         PyConfig_InitPythonConfig(&config);

         /* Set the program name before reading the configuration
            (decode byte string from the locale encoding).

            Implicitly preinitialize Python. */
         status = PyConfig_SetBytesString(&config, &config.program_name,
                                          program_name);
         if (PyStatus_Exception(status)) {
             goto done;
         }

         /* Read all configuration at once */
         status = PyConfig_Read(&config);
         if (PyStatus_Exception(status)) {
             goto done;
         }

         /* Specify sys.path explicitly */
         /* If you want to modify the default set of paths, finish
            initialization first and then use PySys_GetObject("path") */
         config.module_search_paths_set = 1;
         status = PyWideStringList_Append(&config.module_search_paths,
                                          L"/path/to/stdlib");
         if (PyStatus_Exception(status)) {
             goto done;
         }
         status = PyWideStringList_Append(&config.module_search_paths,
                                          L"/path/to/more/modules");
         if (PyStatus_Exception(status)) {
             goto done;
         }

         /* Override executable computed by PyConfig_Read() */
         status = PyConfig_SetString(&config, &config.executable,
                                     L"/path/to/my_executable");
         if (PyStatus_Exception(status)) {
             goto done;
         }

         status = Py_InitializeFromConfig(&config);

     done:
         PyConfig_Clear(&config);
         return status;
     }


File: python.info,  Node: Isolated Configuration,  Next: Python Configuration,  Prev: Initialization with PyConfig,  Up: PyConfig C API

7.11.4.8 Isolated Configuration
...............................

*note PyPreConfig_InitIsolatedConfig(): baf. and *note
PyConfig_InitIsolatedConfig(): ba9. functions create a configuration to
isolate Python from the system.  For example, to embed Python into an
application.

This configuration ignores global configuration variables, environment
variables, command line arguments (*note PyConfig.argv: 3f1. is not
parsed) and user site directory.  The C standard streams (ex: ‘stdout’)
and the LC_CTYPE locale are left unchanged.  Signal handlers are not
installed.

Configuration files are still used with this configuration to determine
paths that are unspecified.  Ensure *note PyConfig.home: 3f3. is
specified to avoid computing the default path configuration.


File: python.info,  Node: Python Configuration,  Next: Python Path Configuration,  Prev: Isolated Configuration,  Up: PyConfig C API

7.11.4.9 Python Configuration
.............................

*note PyPreConfig_InitPythonConfig(): bb0. and *note
PyConfig_InitPythonConfig(): baa. functions create a configuration to
build a customized Python which behaves as the regular Python.

Environments variables and command line arguments are used to configure
Python, whereas global configuration variables are ignored.

This function enables C locale coercion ( PEP 538(1)) and *note Python
UTF-8 Mode: 867. ( PEP 540(2)) depending on the LC_CTYPE locale, *note
PYTHONUTF8: cd1. and *note PYTHONCOERCECLOCALE: cce. environment
variables.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0538/

   (2) https://peps.python.org/pep-0540/


File: python.info,  Node: Python Path Configuration,  Prev: Python Configuration,  Up: PyConfig C API

7.11.4.10 Python Path Configuration
...................................

*note PyConfig: 3f7. contains multiple fields for the path
configuration:

   * Path configuration inputs:

        * *note PyConfig.home: 3f3.

        * *note PyConfig.platlibdir: 1d09.

        * *note PyConfig.pathconfig_warnings: 409.

        * *note PyConfig.program_name: 3f2.

        * *note PyConfig.pythonpath_env: 557d.

        * current working directory: to get absolute paths

        * ‘PATH’ environment variable to get the program full path (from
          *note PyConfig.program_name: 3f2.)

        * ‘__PYVENV_LAUNCHER__’ environment variable

        * (Windows only) Application paths in the registry under
          «SoftwarePythonPythonCoreX.YPythonPath» of HKEY_CURRENT_USER
          and HKEY_LOCAL_MACHINE (where X.Y is the Python version).

   * Path configuration output fields:

        * *note PyConfig.base_exec_prefix: 554e.

        * *note PyConfig.base_executable: 554f.

        * *note PyConfig.base_prefix: 5550.

        * *note PyConfig.exec_prefix: 555b.

        * *note PyConfig.executable: 645.

        * *note PyConfig.module_search_paths_set: 806, *note
          PyConfig.module_search_paths: 643.

        * *note PyConfig.prefix: 5561.

If at least one «output field» is not set, Python calculates the path
configuration to fill unset fields.  If *note module_search_paths_set:
806. is equal to ‘0’, *note module_search_paths: 643. is overridden and
*note module_search_paths_set: 806. is set to ‘1’.

It is possible to completely ignore the function calculating the default
path configuration by setting explicitly all path configuration output
fields listed above.  A string is considered as set even if it is
non-empty.  ‘module_search_paths’ is considered as set if
‘module_search_paths_set’ is set to ‘1’.  In this case,
‘module_search_paths’ will be used without modification.

Set *note pathconfig_warnings: 409. to ‘0’ to suppress warnings when
calculating the path configuration (Unix only, Windows does not log any
warning).

If *note base_prefix: 5550. or *note base_exec_prefix: 554e. fields are
not set, they inherit their value from *note prefix: 5561. and *note
exec_prefix: 555b. respectively.

*note Py_RunMain(): bbe. and *note Py_Main(): e20. modify *note
sys.path: 3e4.:

   * If *note run_filename: 54f3. is set and is a directory which
     contains a ‘__main__.py’ script, prepend *note run_filename: 54f3.
     to *note sys.path: 3e4.

   * If *note isolated: 416. is zero:

        * If *note run_module: 54f4. is set, prepend the current
          directory to *note sys.path: 3e4.  Do nothing if the current
          directory cannot be read.

        * If *note run_filename: 54f3. is set, prepend the directory of
          the filename to *note sys.path: 3e4.

        * Otherwise, prepend an empty string to *note sys.path: 3e4.

If *note site_import: 405. is non-zero, *note sys.path: 3e4. can be
modified by the *note site: cc. module.  If *note user_site_directory:
40f. is non-zero and the user’s site-package directory exists, the *note
site: cc. module appends the user’s site-package directory to *note
sys.path: 3e4.

The following configuration files are used by the path configuration:

   * ‘pyvenv.cfg’

   * ‘._pth’ file (ex: ‘python._pth’)

   * ‘pybuilddir.txt’ (Unix only)

If a ‘._pth’ file is present:

   * Set *note isolated: 416. to ‘1’.

   * Set *note use_environment: 40b. to ‘0’.

   * Set *note site_import: 405. to ‘0’.

   * Set *note safe_path: 978. to ‘1’.

If *note home: 3f3. is not set and a ‘pyvenv.cfg’ file is present in the
same directory as *note executable: 645, or its parent, *note prefix:
5561. and *note exec_prefix: 555b. are set that location.  When this
happens, *note base_prefix: 5550. and *note base_exec_prefix: 554e.
still keep their value, pointing to the base installation.  See *note
Virtual Environments: 489b. for more information.

The ‘__PYVENV_LAUNCHER__’ environment variable is used to set *note
PyConfig.base_executable: 554f.

Cambiato nella versione 3.14: *note prefix: 5561, and *note exec_prefix:
555b, are now set to the ‘pyvenv.cfg’ directory.  This was previously
done by *note site: cc, therefore affected by *note -S: 13b0.


File: python.info,  Node: Py_GetArgcArgv,  Next: Delaying main module execution,  Prev: PyConfig C API,  Up: Python Initialization Configuration

7.11.5 Py_GetArgcArgv()
-----------------------

 -- C Funzione: void Py_GetArgcArgv (int *argc, wchar_t ***argv)

     Get the original command line arguments, before Python modified
     them.

     See also *note PyConfig.orig_argv: a96. member.


File: python.info,  Node: Delaying main module execution,  Prev: Py_GetArgcArgv,  Up: Python Initialization Configuration

7.11.6 Delaying main module execution
-------------------------------------

In some embedding use cases, it may be desirable to separate interpreter
initialization from the execution of the main module.

This separation can be achieved by setting ‘PyConfig.run_command’ to the
empty string during initialization (to prevent the interpreter from
dropping into the interactive prompt), and then subsequently executing
the desired main module code using ‘__main__.__dict__’ as the global
namespace.


File: python.info,  Node: Memory Management,  Next: Object Implementation Support,  Prev: Python Initialization Configuration,  Up: Python/C API Reference Manual

7.12 Memory Management
======================

* Menu:

* Overview: Overview<4>.
* Allocator Domains::
* Raw Memory Interface::
* Memory Interface::
* Object allocators::
* Default Memory Allocators::
* Customize Memory Allocators::
* Debug hooks on the Python memory allocators::
* The pymalloc allocator::
* The mimalloc allocator::
* tracemalloc C API::
* Examples: Examples<38>.


File: python.info,  Node: Overview<4>,  Next: Allocator Domains,  Up: Memory Management

7.12.1 Overview
---------------

Memory management in Python involves a private heap containing all
Python objects and data structures.  The management of this private heap
is ensured internally by the 'Python memory manager'.  The Python memory
manager has different components which deal with various dynamic storage
management aspects, like sharing, segmentation, preallocation or
caching.

At the lowest level, a raw memory allocator ensures that there is enough
room in the private heap for storing all Python-related data by
interacting with the memory manager of the operating system.  On top of
the raw memory allocator, several object-specific allocators operate on
the same heap and implement distinct memory management policies adapted
to the peculiarities of every object type.  For example, integer objects
are managed differently within the heap than strings, tuples or
dictionaries because integers imply different storage requirements and
speed/space tradeoffs.  The Python memory manager thus delegates some of
the work to the object-specific allocators, but ensures that the latter
operate within the bounds of the private heap.

It is important to understand that the management of the Python heap is
performed by the interpreter itself and that the user has no control
over it, even if they regularly manipulate object pointers to memory
blocks inside that heap.  The allocation of heap space for Python
objects and other internal buffers is performed on demand by the Python
memory manager through the Python/C API functions listed in this
document.

To avoid memory corruption, extension writers should never try to
operate on Python objects with the functions exported by the C library:
‘malloc()’, ‘calloc()’, ‘realloc()’ and ‘free()’.  This will result in
mixed calls between the C allocator and the Python memory manager with
fatal consequences, because they implement different algorithms and
operate on different heaps.  However, one may safely allocate and
release memory blocks with the C library allocator for individual
purposes, as shown in the following example:

     PyObject *res;
     char *buf = (char *) malloc(BUFSIZ); /* for I/O */

     if (buf == NULL)
         return PyErr_NoMemory();
     ...Do some I/O operation involving buf...
     res = PyBytes_FromString(buf);
     free(buf); /* malloc'ed */
     return res;

In this example, the memory request for the I/O buffer is handled by the
C library allocator.  The Python memory manager is involved only in the
allocation of the bytes object returned as a result.

In most situations, however, it is recommended to allocate memory from
the Python heap specifically because the latter is under control of the
Python memory manager.  For example, this is required when the
interpreter is extended with new object types written in C. Another
reason for using the Python heap is the desire to 'inform' the Python
memory manager about the memory needs of the extension module.  Even
when the requested memory is used exclusively for internal, highly
specific purposes, delegating all memory requests to the Python memory
manager causes the interpreter to have a more accurate image of its
memory footprint as a whole.  Consequently, under certain circumstances,
the Python memory manager may or may not trigger appropriate actions,
like garbage collection, memory compaction or other preventive
procedures.  Note that by using the C library allocator as shown in the
previous example, the allocated memory for the I/O buffer escapes
completely the Python memory manager.

Vedi anche
..........

The *note PYTHONMALLOC: e60. environment variable can be used to
configure the memory allocators used by Python.

The *note PYTHONMALLOCSTATS: 1f1f. environment variable can be used to
print statistics of the *note pymalloc memory allocator: f0d. every time
a new pymalloc object arena is created, and on shutdown.


File: python.info,  Node: Allocator Domains,  Next: Raw Memory Interface,  Prev: Overview<4>,  Up: Memory Management

7.12.2 Allocator Domains
------------------------

All allocating functions belong to one of three different «domains» (see
also *note PyMemAllocatorDomain: 558b.).  These domains represent
different allocation strategies and are optimized for different
purposes.  The specific details on how every domain allocates memory or
what internal functions each domain calls is considered an
implementation detail, but for debugging purposes a simplified table can
be found at *note Default Memory Allocators: 2124.  The APIs used to
allocate and free a block of memory must be from the same domain.  For
example, *note PyMem_Free(): 1649. must be used to free memory allocated
using *note PyMem_Malloc(): e62.

The three allocation domains are:

   * Raw domain: intended for allocating memory for general-purpose
     memory buffers where the allocation 'must' go to the system
     allocator or where the allocator can operate without an *note
     attached thread state: 4eba.  The memory is requested directly from
     the system.  See *note Raw Memory Interface: 558c.

   * «Mem» domain: intended for allocating memory for Python buffers and
     general-purpose memory buffers where the allocation must be
     performed with an *note attached thread state: 4eba.  The memory is
     taken from the Python private heap.  See *note Memory Interface:
     558d.

   * Object domain: intended for allocating memory for Python objects.
     The memory is taken from the Python private heap.  See *note Object
     allocators: 558e.

     Nota: The *note free-threaded: 1f4. build requires that only Python
     objects are allocated using the «object» domain and that all Python
     objects are allocated using that domain.  This differs from the
     prior Python versions, where this was only a best practice and not
     a hard requirement.

     For example, buffers (non-Python objects) should be allocated using
     *note PyMem_Malloc(): e62, *note PyMem_RawMalloc(): 631, or
     ‘malloc()’, but not *note PyObject_Malloc(): e64.

     See *note Memory Allocation APIs: 558f.


File: python.info,  Node: Raw Memory Interface,  Next: Memory Interface,  Prev: Allocator Domains,  Up: Memory Management

7.12.3 Raw Memory Interface
---------------------------

The following function sets are wrappers to the system allocator.  These
functions are thread-safe, so a *note thread state: 182e. does not need
to be *note attached: 4eba.

The *note default raw memory allocator: 2124. uses the following
functions: ‘malloc()’, ‘calloc()’, ‘realloc()’ and ‘free()’; call
‘malloc(1)’ (or ‘calloc(1, 1)’) when requesting zero bytes.

Added in version 3.4.

 -- C Funzione: void *PyMem_RawMalloc (size_t n)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'
     Allocates 'n' bytes and returns a pointer of type void* to the
     allocated memory, or ‘NULL’ if the request fails.

     Requesting zero bytes returns a distinct non-‘NULL’ pointer if
     possible, as if ‘PyMem_RawMalloc(1)’ had been called instead.  The
     memory will not have been initialized in any way.

 -- C Funzione: void *PyMem_RawCalloc (size_t nelem, size_t elsize)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'
     Allocates 'nelem' elements each whose size in bytes is 'elsize' and
     returns a pointer of type void* to the allocated memory, or ‘NULL’
     if the request fails.  The memory is initialized to zeros.

     Requesting zero elements or elements of size zero bytes returns a
     distinct non-‘NULL’ pointer if possible, as if ‘PyMem_RawCalloc(1,
     1)’ had been called instead.

     Added in version 3.5.

 -- C Funzione: void *PyMem_RawRealloc (void *p, size_t n)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Resizes
     the memory block pointed to by 'p' to 'n' bytes.  The contents will
     be unchanged to the minimum of the old and the new sizes.

     If 'p' is ‘NULL’, the call is equivalent to ‘PyMem_RawMalloc(n)’;
     else if 'n' is equal to zero, the memory block is resized but is
     not freed, and the returned pointer is non-‘NULL’.

     Unless 'p' is ‘NULL’, it must have been returned by a previous call
     to *note PyMem_RawMalloc(): 631, *note PyMem_RawRealloc(): 633. or
     *note PyMem_RawCalloc(): 632.

     If the request fails, *note PyMem_RawRealloc(): 633. returns ‘NULL’
     and 'p' remains a valid pointer to the previous memory area.

 -- C Funzione: void PyMem_RawFree (void *p)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Frees
     the memory block pointed to by 'p', which must have been returned
     by a previous call to *note PyMem_RawMalloc(): 631, *note
     PyMem_RawRealloc(): 633. or *note PyMem_RawCalloc(): 632.
     Otherwise, or if ‘PyMem_RawFree(p)’ has been called before,
     undefined behavior occurs.

     If 'p' is ‘NULL’, no operation is performed.


File: python.info,  Node: Memory Interface,  Next: Object allocators,  Prev: Raw Memory Interface,  Up: Memory Management

7.12.4 Memory Interface
-----------------------

The following function sets, modeled after the ANSI C standard, but
specifying behavior when requesting zero bytes, are available for
allocating and releasing memory from the Python heap.

The *note default memory allocator: 2124. uses the *note pymalloc memory
allocator: f0d.

     Avvertimento: There must be an *note attached thread state: 4eba.
     when using these functions.

Cambiato nella versione 3.6: The default allocator is now pymalloc
instead of system ‘malloc()’.

 -- C Funzione: void *PyMem_Malloc (size_t n)
     ' Parte del *note ABI Stabile: 776.'  Allocates 'n' bytes and
     returns a pointer of type void* to the allocated memory, or ‘NULL’
     if the request fails.

     Requesting zero bytes returns a distinct non-‘NULL’ pointer if
     possible, as if ‘PyMem_Malloc(1)’ had been called instead.  The
     memory will not have been initialized in any way.

 -- C Funzione: void *PyMem_Calloc (size_t nelem, size_t elsize)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Allocates
     'nelem' elements each whose size in bytes is 'elsize' and returns a
     pointer of type void* to the allocated memory, or ‘NULL’ if the
     request fails.  The memory is initialized to zeros.

     Requesting zero elements or elements of size zero bytes returns a
     distinct non-‘NULL’ pointer if possible, as if ‘PyMem_Calloc(1, 1)’
     had been called instead.

     Added in version 3.5.

 -- C Funzione: void *PyMem_Realloc (void *p, size_t n)
     ' Parte del *note ABI Stabile: 776.'  Resizes the memory block
     pointed to by 'p' to 'n' bytes.  The contents will be unchanged to
     the minimum of the old and the new sizes.

     If 'p' is ‘NULL’, the call is equivalent to ‘PyMem_Malloc(n)’; else
     if 'n' is equal to zero, the memory block is resized but is not
     freed, and the returned pointer is non-‘NULL’.

     Unless 'p' is ‘NULL’, it must have been returned by a previous call
     to *note PyMem_Malloc(): e62, *note PyMem_Realloc(): 1234. or *note
     PyMem_Calloc(): 10af.

     If the request fails, *note PyMem_Realloc(): 1234. returns ‘NULL’
     and 'p' remains a valid pointer to the previous memory area.

 -- C Funzione: void PyMem_Free (void *p)
     ' Parte del *note ABI Stabile: 776.'  Frees the memory block
     pointed to by 'p', which must have been returned by a previous call
     to *note PyMem_Malloc(): e62, *note PyMem_Realloc(): 1234. or *note
     PyMem_Calloc(): 10af.  Otherwise, or if ‘PyMem_Free(p)’ has been
     called before, undefined behavior occurs.

     If 'p' is ‘NULL’, no operation is performed.

The following type-oriented macros are provided for convenience.  Note
that 'TYPE' refers to any C type.

 -- C Macro: PyMem_New (TYPE, n)

     Same as *note PyMem_Malloc(): e62, but allocates ‘(n *
     sizeof(TYPE))’ bytes of memory.  Returns a pointer cast to ‘TYPE*’.
     The memory will not have been initialized in any way.

 -- C Macro: PyMem_Resize (p, TYPE, n)

     Same as *note PyMem_Realloc(): 1234, but the memory block is
     resized to ‘(n * sizeof(TYPE))’ bytes.  Returns a pointer cast to
     ‘TYPE*’.  On return, 'p' will be a pointer to the new memory area,
     or ‘NULL’ in the event of failure.

     This is a C preprocessor macro; 'p' is always reassigned.  Save the
     original value of 'p' to avoid losing memory when handling errors.

 -- C Funzione: void PyMem_Del (void *p)

     Same as *note PyMem_Free(): 1649.

* Menu:

* Deprecated aliases: Deprecated aliases<2>.


File: python.info,  Node: Deprecated aliases<2>,  Up: Memory Interface

7.12.4.1 Deprecated aliases
...........................

These are *note soft deprecated: 23d. aliases to existing functions and
macros.  They exist solely for backwards compatibility.

Deprecated alias                                       Corresponding function or macro
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
 -- C Macro: PyMem_MALLOC (size)                       *note PyMem_Malloc(): e62.
                                                       
                                                       
 -- C Macro: PyMem_NEW (type, size)                    *note PyMem_New: 172b.
                                                       
                                                       
 -- C Macro: PyMem_REALLOC (ptr, size)                 *note PyMem_Realloc(): 1234.
                                                       
                                                       
 -- C Macro: PyMem_RESIZE (ptr, type, size)            *note PyMem_Resize: 5592.
                                                       
                                                       
 -- C Macro: PyMem_FREE (ptr)                          *note PyMem_Free(): 1649.
                                                       
                                                       
 -- C Macro: PyMem_DEL (ptr)                           *note PyMem_Free(): 1649.
                                                       

Cambiato nella versione 3.4: The macros are now aliases of the
corresponding functions and macros.  Previously, their behavior was the
same, but their use did not necessarily preserve binary compatibility
across Python versions.

Deprecato dalla versione 2.0.


File: python.info,  Node: Object allocators,  Next: Default Memory Allocators,  Prev: Memory Interface,  Up: Memory Management

7.12.5 Object allocators
------------------------

The following function sets, modeled after the ANSI C standard, but
specifying behavior when requesting zero bytes, are available for
allocating and releasing memory from the Python heap.

     Nota: There is no guarantee that the memory returned by these
     allocators can be successfully cast to a Python object when
     intercepting the allocating functions in this domain by the methods
     described in the *note Customize Memory Allocators: 559b. section.

The *note default object allocator: 2124. uses the *note pymalloc memory
allocator: f0d.

     Avvertimento: There must be an *note attached thread state: 4eba.
     when using these functions.

 -- C Funzione: void *PyObject_Malloc (size_t n)
     ' Parte del *note ABI Stabile: 776.'  Allocates 'n' bytes and
     returns a pointer of type void* to the allocated memory, or ‘NULL’
     if the request fails.

     Requesting zero bytes returns a distinct non-‘NULL’ pointer if
     possible, as if ‘PyObject_Malloc(1)’ had been called instead.  The
     memory will not have been initialized in any way.

 -- C Funzione: void *PyObject_Calloc (size_t nelem, size_t elsize)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Allocates
     'nelem' elements each whose size in bytes is 'elsize' and returns a
     pointer of type void* to the allocated memory, or ‘NULL’ if the
     request fails.  The memory is initialized to zeros.

     Requesting zero elements or elements of size zero bytes returns a
     distinct non-‘NULL’ pointer if possible, as if ‘PyObject_Calloc(1,
     1)’ had been called instead.

     Added in version 3.5.

 -- C Funzione: void *PyObject_Realloc (void *p, size_t n)
     ' Parte del *note ABI Stabile: 776.'  Resizes the memory block
     pointed to by 'p' to 'n' bytes.  The contents will be unchanged to
     the minimum of the old and the new sizes.

     If 'p' is ‘NULL’, the call is equivalent to ‘PyObject_Malloc(n)’;
     else if 'n' is equal to zero, the memory block is resized but is
     not freed, and the returned pointer is non-‘NULL’.

     Unless 'p' is ‘NULL’, it must have been returned by a previous call
     to *note PyObject_Malloc(): e64, *note PyObject_Realloc(): 164a. or
     *note PyObject_Calloc(): 10b0.

     If the request fails, *note PyObject_Realloc(): 164a. returns
     ‘NULL’ and 'p' remains a valid pointer to the previous memory area.

 -- C Funzione: void PyObject_Free (void *p)
     ' Parte del *note ABI Stabile: 776.'  Frees the memory block
     pointed to by 'p', which must have been returned by a previous call
     to *note PyObject_Malloc(): e64, *note PyObject_Realloc(): 164a. or
     *note PyObject_Calloc(): 10b0.  Otherwise, or if ‘PyObject_Free(p)’
     has been called before, undefined behavior occurs.

     If 'p' is ‘NULL’, no operation is performed.

     Do not call this directly to free an object’s memory; call the
     type’s *note tp_free: 4eb8. slot instead.

     Do not use this for memory allocated by *note PyObject_GC_New: c9b.
     or *note PyObject_GC_NewVar: c9c.; use *note PyObject_GC_Del():
     170a. instead.

     Vedi anche
     ..........

        * *note PyObject_GC_Del(): 170a. is the equivalent of this
          function for memory allocated by types that support garbage
          collection.

        * *note PyObject_Malloc(): e64.

        * *note PyObject_Realloc(): 164a.

        * *note PyObject_Calloc(): 10b0.

        * *note PyObject_New: b7e.

        * *note PyObject_NewVar: b7f.

        * *note PyType_GenericAlloc(): c63.

        * *note tp_free: 4eb8.


File: python.info,  Node: Default Memory Allocators,  Next: Customize Memory Allocators,  Prev: Object allocators,  Up: Memory Management

7.12.6 Default Memory Allocators
--------------------------------

Default memory allocators:

Configuration                       Name                     PyMem_RawMalloc        PyMem_Malloc              PyObject_Malloc
                                                                                                              
---------------------------------------------------------------------------------------------------------------------------------------
                                                                                                              
Release build                       ‘"pymalloc"’             ‘malloc’               ‘pymalloc’                ‘pymalloc’
                                                                                                              
                                                                                                              
Debug build                         ‘"pymalloc_debug"’       ‘malloc’ + debug       ‘pymalloc’ + debug        ‘pymalloc’ + debug
                                                                                                              
                                                                                                              
Release build, without pymalloc     ‘"malloc"’               ‘malloc’               ‘malloc’                  ‘malloc’
                                                                                                              
                                                                                                              
Debug build, without pymalloc       ‘"malloc_debug"’         ‘malloc’ + debug       ‘malloc’ + debug          ‘malloc’ + debug
                                                                                                              

Legend:

   * Name: value for *note PYTHONMALLOC: e60. environment variable.

   * ‘malloc’: system allocators from the standard C library, C
     functions: ‘malloc()’, ‘calloc()’, ‘realloc()’ and ‘free()’.

   * ‘pymalloc’: *note pymalloc memory allocator: f0d.

   * ‘mimalloc’: *note mimalloc memory allocator: 2126.  The pymalloc
     allocator will be used if mimalloc support isn’t available.

   * «+ debug»: with *note debug hooks on the Python memory allocators:
     2127.

   * «Debug build»: *note Python build in debug mode: 50a.


File: python.info,  Node: Customize Memory Allocators,  Next: Debug hooks on the Python memory allocators,  Prev: Default Memory Allocators,  Up: Memory Management

7.12.7 Customize Memory Allocators
----------------------------------

Added in version 3.4.

 -- C Tipo: type PyMemAllocatorEx

     Structure used to describe a memory block allocator.  The structure
     has the following fields:

     Field                                                          Meaning
                                                                    
     -----------------------------------------------------------------------------------------------------------
                                                                    
     ‘void *ctx’                                                    user context passed as first argument
                                                                    
                                                                    
     ‘void* malloc(void *ctx, size_t size)’                         allocate a memory block
                                                                    
                                                                    
     ‘void* calloc(void *ctx, size_t nelem, size_t elsize)’         allocate a memory block initialized with
                                                                    zeros
                                                                    
                                                                    
     ‘void* realloc(void *ctx, void *ptr, size_t new_size)’         allocate or resize a memory block
                                                                    
                                                                    
     ‘void free(void *ctx, void *ptr)’                              free a memory block
                                                                    

     Cambiato nella versione 3.5: The ‘PyMemAllocator’ structure was
     renamed to *note PyMemAllocatorEx: 10d0. and a new ‘calloc’ field
     was added.

 -- C Tipo: type PyMemAllocatorDomain

     Enum used to identify an allocator domain.  Domains:

      -- C Macro: PYMEM_DOMAIN_RAW

          Functions:

             * *note PyMem_RawMalloc(): 631.

             * *note PyMem_RawRealloc(): 633.

             * *note PyMem_RawCalloc(): 632.

             * *note PyMem_RawFree(): 634.

      -- C Macro: PYMEM_DOMAIN_MEM

          Functions:

             * *note PyMem_Malloc(): e62,

             * *note PyMem_Realloc(): 1234.

             * *note PyMem_Calloc(): 10af.

             * *note PyMem_Free(): 1649.

      -- C Macro: PYMEM_DOMAIN_OBJ

          Functions:

             * *note PyObject_Malloc(): e64.

             * *note PyObject_Realloc(): 164a.

             * *note PyObject_Calloc(): 10b0.

             * *note PyObject_Free(): e61.

 -- C Funzione: void PyMem_GetAllocator (PyMemAllocatorDomain domain,
          PyMemAllocatorEx *allocator)

     Get the memory block allocator of the specified domain.

 -- C Funzione: void PyMem_SetAllocator (PyMemAllocatorDomain domain,
          PyMemAllocatorEx *allocator)

     Set the memory block allocator of the specified domain.

     The new allocator must return a distinct non-‘NULL’ pointer when
     requesting zero bytes.

     For the *note PYMEM_DOMAIN_RAW: 2125. domain, the allocator must be
     thread-safe: a *note thread state: 182e. is not *note attached:
     4eba. when the allocator is called.

     For the remaining domains, the allocator must also be thread-safe:
     the allocator may be called in different interpreters that do not
     share a *note GIL: 164.

     If the new allocator is not a hook (does not call the previous
     allocator), the *note PyMem_SetupDebugHooks(): e66. function must
     be called to reinstall the debug hooks on top on the new allocator.

     See also *note PyPreConfig.allocator: 554d. and *note Preinitialize
     Python with PyPreConfig: 42af.

          Avvertimento: *note PyMem_SetAllocator(): 7a9. does have the
          following contract:

             * It can be called after *note Py_PreInitialize(): 41e. and
               before *note Py_InitializeFromConfig(): 3f6. to install a
               custom memory allocator.  There are no restrictions over
               the installed allocator other than the ones imposed by
               the domain (for instance, the Raw Domain allows the
               allocator to be called without an *note attached thread
               state: 4eba.).  See *note the section on allocator
               domains: 558a. for more information.

             * If called after Python has finish initializing (after
               *note Py_InitializeFromConfig(): 3f6. has been called)
               the allocator 'must' wrap the existing allocator.
               Substituting the current allocator for some other
               arbitrary one is 'not supported'.

     Cambiato nella versione 3.12: All allocators must be thread-safe.

 -- C Funzione: void PyMem_SetupDebugHooks (void)

     Setup *note debug hooks in the Python memory allocators: 2127. to
     detect memory errors.


File: python.info,  Node: Debug hooks on the Python memory allocators,  Next: The pymalloc allocator,  Prev: Customize Memory Allocators,  Up: Memory Management

7.12.8 Debug hooks on the Python memory allocators
--------------------------------------------------

When *note Python is built in debug mode: 50a, the *note
PyMem_SetupDebugHooks(): e66. function is called at the *note Python
preinitialization: 42af. to setup debug hooks on Python memory
allocators to detect memory errors.

The *note PYTHONMALLOC: e60. environment variable can be used to install
debug hooks on a Python compiled in release mode (ex:
‘PYTHONMALLOC=debug’).

The *note PyMem_SetupDebugHooks(): e66. function can be used to set
debug hooks after calling *note PyMem_SetAllocator(): 7a9.

These debug hooks fill dynamically allocated memory blocks with special,
recognizable bit patterns.  Newly allocated memory is filled with the
byte ‘0xCD’ (‘PYMEM_CLEANBYTE’), freed memory is filled with the byte
‘0xDD’ (‘PYMEM_DEADBYTE’).  Memory blocks are surrounded by «forbidden
bytes» filled with the byte ‘0xFD’ (‘PYMEM_FORBIDDENBYTE’).  Strings of
these bytes are unlikely to be valid addresses, floats, or ASCII
strings.

Runtime checks:

   - Detect API violations.  For example, detect if *note
     PyObject_Free(): e61. is called on a memory block allocated by
     *note PyMem_Malloc(): e62.

   - Detect write before the start of the buffer (buffer underflow).

   - Detect write after the end of the buffer (buffer overflow).

   - Check that there is an *note attached thread state: 4eba. when
     allocator functions of *note PYMEM_DOMAIN_OBJ: e63. (ex: *note
     PyObject_Malloc(): e64.) and *note PYMEM_DOMAIN_MEM: e65. (ex:
     *note PyMem_Malloc(): e62.) domains are called.

On error, the debug hooks use the *note tracemalloc: 105. module to get
the traceback where a memory block was allocated.  The traceback is only
displayed if *note tracemalloc: 105. is tracing Python memory
allocations and the memory block was traced.

Let 'S' = ‘sizeof(size_t)’.  ‘2*S’ bytes are added at each end of each
block of 'N' bytes requested.  The memory layout is like so, where p
represents the address returned by a malloc-like or realloc-like
function (‘p[i:j]’ means the slice of bytes from ‘*(p+i)’ inclusive up
to ‘*(p+j)’ exclusive; note that the treatment of negative indices
differs from a Python slice):

‘p[-2*S:-S]’

     Number of bytes originally asked for.  This is a size_t, big-endian
     (easier to read in a memory dump).

‘p[-S]’

     API identifier (ASCII character):

        * ‘'r'’ for *note PYMEM_DOMAIN_RAW: 2125.

        * ‘'m'’ for *note PYMEM_DOMAIN_MEM: e65.

        * ‘'o'’ for *note PYMEM_DOMAIN_OBJ: e63.

‘p[-S+1:0]’

     Copies of PYMEM_FORBIDDENBYTE. Used to catch under- writes and
     reads.

‘p[0:N]’

     The requested memory, filled with copies of PYMEM_CLEANBYTE, used
     to catch reference to uninitialized memory.  When a realloc-like
     function is called requesting a larger memory block, the new excess
     bytes are also filled with PYMEM_CLEANBYTE. When a free-like
     function is called, these are overwritten with PYMEM_DEADBYTE, to
     catch reference to freed memory.  When a realloc- like function is
     called requesting a smaller memory block, the excess old bytes are
     also filled with PYMEM_DEADBYTE.

‘p[N:N+S]’

     Copies of PYMEM_FORBIDDENBYTE. Used to catch over- writes and
     reads.

‘p[N+S:N+2*S]’

     Only used if the ‘PYMEM_DEBUG_SERIALNO’ macro is defined (not
     defined by default).

     A serial number, incremented by 1 on each call to a malloc-like or
     realloc-like function.  Big-endian ‘size_t’.  If «bad memory» is
     detected later, the serial number gives an excellent way to set a
     breakpoint on the next run, to capture the instant at which this
     block was passed out.  The static function bumpserialno() in
     obmalloc.c is the only place the serial number is incremented, and
     exists so you can set such a breakpoint easily.

A realloc-like or free-like function first checks that the
PYMEM_FORBIDDENBYTE bytes at each end are intact.  If they’ve been
altered, diagnostic output is written to stderr, and the program is
aborted via Py_FatalError().  The other main failure mode is provoking a
memory error when a program reads up one of the special bit patterns and
tries to use it as an address.  If you get in a debugger then and look
at the object, you’re likely to see that it’s entirely filled with
PYMEM_DEADBYTE (meaning freed memory is getting used) or PYMEM_CLEANBYTE
(meaning uninitialized memory is getting used).

Cambiato nella versione 3.6: The *note PyMem_SetupDebugHooks(): e66.
function now also works on Python compiled in release mode.  On error,
the debug hooks now use *note tracemalloc: 105. to get the traceback
where a memory block was allocated.  The debug hooks now also check if
there is an *note attached thread state: 4eba. when functions of *note
PYMEM_DOMAIN_OBJ: e63. and *note PYMEM_DOMAIN_MEM: e65. domains are
called.

Cambiato nella versione 3.8: Byte patterns ‘0xCB’ (‘PYMEM_CLEANBYTE’),
‘0xDB’ (‘PYMEM_DEADBYTE’) and ‘0xFB’ (‘PYMEM_FORBIDDENBYTE’) have been
replaced with ‘0xCD’, ‘0xDD’ and ‘0xFD’ to use the same values than
Windows CRT debug ‘malloc()’ and ‘free()’.


File: python.info,  Node: The pymalloc allocator,  Next: The mimalloc allocator,  Prev: Debug hooks on the Python memory allocators,  Up: Memory Management

7.12.9 The pymalloc allocator
-----------------------------

Python has a 'pymalloc' allocator optimized for small objects (smaller
or equal to 512 bytes) with a short lifetime.  It uses memory mappings
called «arenas» with a fixed size of either 256 KiB on 32-bit platforms
or 1 MiB on 64-bit platforms.  It falls back to *note PyMem_RawMalloc():
631. and *note PyMem_RawRealloc(): 633. for allocations larger than 512
bytes.

'pymalloc' is the *note default allocator: 2124. of the *note
PYMEM_DOMAIN_MEM: e65. (ex: *note PyMem_Malloc(): e62.) and *note
PYMEM_DOMAIN_OBJ: e63. (ex: *note PyObject_Malloc(): e64.) domains.

The arena allocator uses the following functions:

   * ‘VirtualAlloc()’ and ‘VirtualFree()’ on Windows,

   * ‘mmap()’ and ‘munmap()’ if available,

   * ‘malloc()’ and ‘free()’ otherwise.

This allocator is disabled if Python is configured with the *note
-without-pymalloc: 218a. option.  It can also be disabled at runtime
using the *note PYTHONMALLOC: e60. environment variable (ex:
‘PYTHONMALLOC=malloc’).

Typically, it makes sense to disable the pymalloc allocator when
building Python with AddressSanitizer (*note -with-address-sanitizer:
2193.) which helps uncover low level bugs within the C code.

* Menu:

* Customize pymalloc Arena Allocator::


File: python.info,  Node: Customize pymalloc Arena Allocator,  Up: The pymalloc allocator

7.12.9.1 Customize pymalloc Arena Allocator
...........................................

Added in version 3.4.

 -- C Tipo: type PyObjectArenaAllocator

     Structure used to describe an arena allocator.  The structure has
     three fields:

     Field                                                  Meaning
                                                            
     ---------------------------------------------------------------------------------------------------
                                                            
     ‘void *ctx’                                            user context passed as first argument
                                                            
                                                            
     ‘void* alloc(void *ctx, size_t size)’                  allocate an arena of size bytes
                                                            
                                                            
     ‘void free(void *ctx, void *ptr, size_t size)’         free an arena
                                                            

 -- C Funzione: void PyObject_GetArenaAllocator (PyObjectArenaAllocator
          *allocator)

     Get the arena allocator.

 -- C Funzione: void PyObject_SetArenaAllocator (PyObjectArenaAllocator
          *allocator)

     Set the arena allocator.


File: python.info,  Node: The mimalloc allocator,  Next: tracemalloc C API,  Prev: The pymalloc allocator,  Up: Memory Management

7.12.10 The mimalloc allocator
------------------------------

Added in version 3.13.

Python supports the mimalloc allocator when the underlying platform
support is available.  mimalloc «is a general purpose allocator with
excellent performance characteristics.  Initially developed by Daan
Leijen for the runtime systems of the Koka and Lean languages.»


File: python.info,  Node: tracemalloc C API,  Next: Examples<38>,  Prev: The mimalloc allocator,  Up: Memory Management

7.12.11 tracemalloc C API
-------------------------

Added in version 3.7.

 -- C Funzione: int PyTraceMalloc_Track (unsigned int domain, uintptr_t
          ptr, size_t size)

     Track an allocated memory block in the *note tracemalloc: 105.
     module.

     Return ‘0’ on success, return ‘-1’ on error (failed to allocate
     memory to store the trace).  Return ‘-2’ if tracemalloc is
     disabled.

     If memory block is already tracked, update the existing trace.

 -- C Funzione: int PyTraceMalloc_Untrack (unsigned int domain,
          uintptr_t ptr)

     Untrack an allocated memory block in the *note tracemalloc: 105.
     module.  Do nothing if the block was not tracked.

     Return ‘-2’ if tracemalloc is disabled, otherwise return ‘0’.


File: python.info,  Node: Examples<38>,  Prev: tracemalloc C API,  Up: Memory Management

7.12.12 Examples
----------------

Here is the example from section *note Overview: 5587, rewritten so that
the I/O buffer is allocated from the Python heap by using the first
function set:

     PyObject *res;
     char *buf = (char *) PyMem_Malloc(BUFSIZ); /* for I/O */

     if (buf == NULL)
         return PyErr_NoMemory();
     /* ...Do some I/O operation involving buf... */
     res = PyBytes_FromString(buf);
     PyMem_Free(buf); /* allocated with PyMem_Malloc */
     return res;

The same code using the type-oriented function set:

     PyObject *res;
     char *buf = PyMem_New(char, BUFSIZ); /* for I/O */

     if (buf == NULL)
         return PyErr_NoMemory();
     /* ...Do some I/O operation involving buf... */
     res = PyBytes_FromString(buf);
     PyMem_Free(buf); /* allocated with PyMem_New */
     return res;

Note that in the two examples above, the buffer is always manipulated
via functions belonging to the same set.  Indeed, it is required to use
the same memory API family for a given memory block, so that the risk of
mixing different allocators is reduced to a minimum.  The following code
sequence contains two errors, one of which is labeled as 'fatal' because
it mixes two different allocators operating on different heaps.

     char *buf1 = PyMem_New(char, BUFSIZ);
     char *buf2 = (char *) malloc(BUFSIZ);
     char *buf3 = (char *) PyMem_Malloc(BUFSIZ);
     ...
     PyMem_Del(buf3);  /* Wrong -- should be PyMem_Free() */
     free(buf2);       /* Right -- allocated via malloc() */
     free(buf1);       /* Fatal -- should be PyMem_Free()  */

In addition to the functions aimed at handling raw memory blocks from
the Python heap, objects in Python are allocated and released with *note
PyObject_New: b7e, *note PyObject_NewVar: b7f. and *note
PyObject_Free(): e61.

These will be explained in the next chapter on defining and implementing
new object types in C.


File: python.info,  Node: Object Implementation Support,  Next: API and ABI Versioning,  Prev: Memory Management,  Up: Python/C API Reference Manual

7.13 Object Implementation Support
==================================

This chapter describes the functions, types, and macros used when
defining new object types.

* Menu:

* Allocating Objects on the Heap::
* Object Life Cycle::
* Common Object Structures::
* Type Object Structures::
* Supporting Cyclic Garbage Collection::


File: python.info,  Node: Allocating Objects on the Heap,  Next: Object Life Cycle,  Up: Object Implementation Support

7.13.1 Allocating Objects on the Heap
-------------------------------------

 -- C Funzione: *note PyObject: 5df. *_PyObject_New (PyTypeObject *type)
     'Valore di ritorno: Nuovo riferimento.'

 -- C Funzione: *note PyVarObject: 46be. *_PyObject_NewVar (PyTypeObject
          *type, Py_ssize_t size)
     'Valore di ritorno: Nuovo riferimento.'

 -- C Funzione: *note PyObject: 5df. *PyObject_Init (PyObject *op,
          PyTypeObject *type)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  Initialize a newly allocated object 'op'
     with its type and initial reference.  Returns the initialized
     object.  Other fields of the object are not initialized.  Despite
     its name, this function is unrelated to the object’s *note
     __init__(): 8c0. method (*note tp_init: 7a2. slot).  Specifically,
     this function does 'not' call the object’s ‘__init__()’ method.

     In general, consider this function to be a low-level routine.  Use
     *note tp_alloc: 4eb9. where possible.  For implementing ‘tp_alloc’
     for your type, prefer *note PyType_GenericAlloc(): c63. or *note
     PyObject_New(): b7e.

          Nota: This function only initializes the object’s memory
          corresponding to the initial *note PyObject: 5df. structure.
          It does not zero the rest.

 -- C Funzione: *note PyVarObject: 46be. *PyObject_InitVar (PyVarObject
          *op, PyTypeObject *type, Py_ssize_t size)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776.'  This does everything *note
     PyObject_Init(): c62. does, and also initializes the length
     information for a variable-size object.

          Nota: This function only initializes some of the object’s
          memory.  It does not zero the rest.

 -- C Macro: PyObject_New (TYPE, typeobj)

     Allocates a new Python object using the C structure type 'TYPE' and
     the Python type object 'typeobj' (‘PyTypeObject*’) by calling *note
     PyObject_Malloc(): e64. to allocate memory and initializing it like
     *note PyObject_Init(): c62.  The caller will own the only reference
     to the object (i.e.  its reference count will be one).

     Avoid calling this directly to allocate memory for an object; call
     the type’s *note tp_alloc: 4eb9. slot instead.

     When populating a type’s *note tp_alloc: 4eb9. slot, *note
     PyType_GenericAlloc(): c63. is preferred over a custom function
     that simply calls this macro.

     This macro does not call *note tp_alloc: 4eb9, *note tp_new: 7a0.
     (*note __new__(): 7a1.), or *note tp_init: 7a2. (*note __init__():
     8c0.).

     This cannot be used for objects with *note Py_TPFLAGS_HAVE_GC: 982.
     set in *note tp_flags: 1c59.; use *note PyObject_GC_New: c9b.
     instead.

     Memory allocated by this macro must be freed with *note
     PyObject_Free(): e61. (usually called via the object’s *note
     tp_free: 4eb8. slot).

          Nota: The returned memory is not guaranteed to have been
          completely zeroed before it was initialized.

          Nota: This macro does not construct a fully initialized object
          of the given type; it merely allocates memory and prepares it
          for further initialization by *note tp_init: 7a2.  To
          construct a fully initialized object, call 'typeobj' instead.
          For example:

               PyObject *foo = PyObject_CallNoArgs((PyObject *)&PyFoo_Type);

     Vedi anche
     ..........

        * *note PyObject_Free(): e61.

        * *note PyObject_GC_New: c9b.

        * *note PyType_GenericAlloc(): c63.

        * *note tp_alloc: 4eb9.

 -- C Macro: PyObject_NewVar (TYPE, typeobj, size)

     Like *note PyObject_New: b7e. except:

        * It allocates enough memory for the 'TYPE' structure plus
          'size' (‘Py_ssize_t’) fields of the size given by the *note
          tp_itemsize: 23a1. field of 'typeobj'.

        * The memory is initialized like *note PyObject_InitVar(): 1d28.

     This is useful for implementing objects like tuples, which are able
     to determine their size at construction time.  Embedding the array
     of fields into the same allocation decreases the number of
     allocations, improving the memory management efficiency.

     Avoid calling this directly to allocate memory for an object; call
     the type’s *note tp_alloc: 4eb9. slot instead.

     When populating a type’s *note tp_alloc: 4eb9. slot, *note
     PyType_GenericAlloc(): c63. is preferred over a custom function
     that simply calls this macro.

     This cannot be used for objects with *note Py_TPFLAGS_HAVE_GC: 982.
     set in *note tp_flags: 1c59.; use *note PyObject_GC_NewVar: c9c.
     instead.

     Memory allocated by this function must be freed with *note
     PyObject_Free(): e61. (usually called via the object’s *note
     tp_free: 4eb8. slot).

          Nota: The returned memory is not guaranteed to have been
          completely zeroed before it was initialized.

          Nota: This macro does not construct a fully initialized object
          of the given type; it merely allocates memory and prepares it
          for further initialization by *note tp_init: 7a2.  To
          construct a fully initialized object, call 'typeobj' instead.
          For example:

               PyObject *list_instance = PyObject_CallNoArgs((PyObject *)&PyList_Type);

     Vedi anche
     ..........

        * *note PyObject_Free(): e61.

        * *note PyObject_GC_NewVar: c9c.

        * *note PyType_GenericAlloc(): c63.

        * *note tp_alloc: 4eb9.

 -- C Variabile: *note PyObject: 5df. _Py_NoneStruct

     Object which is visible in Python as ‘None’.  This should only be
     accessed using the *note Py_None: 4e88. macro, which evaluates to a
     pointer to this object.

Vedi anche
..........

*note Module Objects: 5416.

     To allocate and create extension modules.

* Menu:

* Deprecated aliases: Deprecated aliases<3>.


File: python.info,  Node: Deprecated aliases<3>,  Up: Allocating Objects on the Heap

7.13.1.1 Deprecated aliases
...........................

These are *note soft deprecated: 23d. aliases to existing functions and
macros.  They exist solely for backwards compatibility.

Deprecated alias                                       Function
                                                       
--------------------------------------------------------------------------------------------------------------
                                                       
 -- C Macro: PyObject_NEW (type, typeobj)              *note PyObject_New: b7e.
                                                       
                                                       
 -- C Macro: PyObject_NEW_VAR (type, typeobj, n)       *note PyObject_NewVar: b7f.
                                                       
                                                       
 -- C Macro: PyObject_INIT (op, typeobj)               *note PyObject_Init(): c62.
                                                       
                                                       
 -- C Macro: PyObject_INIT_VAR (op, typeobj, n)        *note PyObject_InitVar(): 1d28.
                                                       
                                                       
 -- C Macro: PyObject_MALLOC (n)                       *note PyObject_Malloc(): e64.
                                                       
                                                       
 -- C Macro: PyObject_REALLOC (p, n)                   *note PyObject_Realloc(): 164a.
                                                       
                                                       
 -- C Macro: PyObject_FREE (p)                         *note PyObject_Free(): e61.
                                                       
                                                       
 -- C Macro: PyObject_DEL (p)                          *note PyObject_Free(): e61.
                                                       
                                                       
 -- C Macro: PyObject_Del (p)                          *note PyObject_Free(): e61.
                                                       


File: python.info,  Node: Object Life Cycle,  Next: Common Object Structures,  Prev: Allocating Objects on the Heap,  Up: Object Implementation Support

7.13.2 Object Life Cycle
------------------------

This section explains how a type’s slots relate to each other throughout
the life of an object.  It is not intended to be a complete canonical
reference for the slots; instead, refer to the slot-specific
documentation in *note Type Object Structures: b86. for details about a
particular slot.

* Menu:

* Life Events::
* Cyclic Isolate Destruction::
* Functions: Functions<14>.


File: python.info,  Node: Life Events,  Next: Cyclic Isolate Destruction,  Up: Object Life Cycle

7.13.2.1 Life Events
....................

The figure below illustrates the order of events that can occur
throughout an object’s life.  An arrow from 'A' to 'B' indicates that
event 'B' can occur after event 'A' has occurred, with the arrow’s label
indicating the condition that must be true for 'B' to occur after 'A'.

[image src="python-figures/lifecycle.dot.svg" alt="Diagram showing events in an object's life. Explained in detail below."]


Explanation:

   * When a new object is constructed by calling its type:

       1. *note tp_new: 7a0. is called to create a new object.

       2. *note tp_alloc: 4eb9. is directly called by *note tp_new: 7a0.
          to allocate the memory for the new object.

       3. *note tp_init: 7a2. initializes the newly created object.
          ‘tp_init’ can be called again to re-initialize an object, if
          desired.  The ‘tp_init’ call can also be skipped entirely, for
          example by Python code calling *note __new__(): 7a1.

   * After ‘tp_init’ completes, the object is ready to use.

   * Some time after the last reference to an object is removed:

       1. If an object is not marked as 'finalized', it might be
          finalized by marking it as 'finalized' and calling its *note
          tp_finalize: c9f. function.  Python does 'not' finalize an
          object when the last reference to it is deleted; use *note
          PyObject_CallFinalizerFromDealloc(): 55bc. to ensure that
          *note tp_finalize: c9f. is always called.

       2. If the object is marked as finalized, *note tp_clear: 4ecb.
          might be called by the garbage collector to clear references
          held by the object.  It is 'not' called when the object’s
          reference count reaches zero.

       3. *note tp_dealloc: 4ea5. is called to destroy the object.  To
          avoid code duplication, *note tp_dealloc: 4ea5. typically
          calls into *note tp_clear: 4ecb. to free up the object’s
          references.

       4. When *note tp_dealloc: 4ea5. finishes object destruction, it
          directly calls *note tp_free: 4eb8. (usually set to *note
          PyObject_Free(): e61. or *note PyObject_GC_Del(): 170a.
          automatically as appropriate for the type) to deallocate the
          memory.

   * The *note tp_finalize: c9f. function is permitted to add a
     reference to the object if desired.  If it does, the object is
     'resurrected', preventing its pending destruction.  (Only
     ‘tp_finalize’ is allowed to resurrect an object; *note tp_clear:
     4ecb. and *note tp_dealloc: 4ea5. cannot without calling into
     ‘tp_finalize’.)  Resurrecting an object may or may not cause the
     object’s 'finalized' mark to be removed.  Currently, Python does
     not remove the 'finalized' mark from a resurrected object if it
     supports garbage collection (i.e., the *note Py_TPFLAGS_HAVE_GC:
     982. flag is set) but does remove the mark if the object does not
     support garbage collection; either or both of these behaviors may
     change in the future.

   * *note tp_dealloc: 4ea5. can optionally call *note tp_finalize: c9f.
     via *note PyObject_CallFinalizerFromDealloc(): 55bc. if it wishes
     to reuse that code to help with object destruction.  This is
     recommended because it guarantees that ‘tp_finalize’ is always
     called before destruction.  See the *note tp_dealloc: 4ea5.
     documentation for example code.

   * If the object is a member of a *note cyclic isolate: 55bd. and
     either *note tp_clear: 4ecb. fails to break the reference cycle or
     the cyclic isolate is not detected (perhaps *note gc.disable():
     49f7. was called, or the *note Py_TPFLAGS_HAVE_GC: 982. flag was
     erroneously omitted in one of the involved types), the objects
     remain indefinitely uncollectable (they «leak»).  See *note
     gc.garbage: 13c9.

If the object is marked as supporting garbage collection (the *note
Py_TPFLAGS_HAVE_GC: 982. flag is set in *note tp_flags: 1c59.), the
following events are also possible:

   * The garbage collector occasionally calls *note tp_traverse: 983. to
     identify *note cyclic isolates: 55bd.

   * When the garbage collector discovers a *note cyclic isolate: 55bd,
     it finalizes one of the objects in the group by marking it as
     'finalized' and calling its *note tp_finalize: c9f. function, if it
     has one.  This repeats until the cyclic isolate doesn’t exist or
     all of the objects have been finalized.

   * *note tp_finalize: c9f. is permitted to resurrect the object by
     adding a reference from outside the *note cyclic isolate: 55bd.
     The new reference causes the group of objects to no longer form a
     cyclic isolate (the reference cycle may still exist, but if it does
     the objects are no longer isolated).

   * When the garbage collector discovers a *note cyclic isolate: 55bd.
     and all of the objects in the group have already been marked as
     'finalized', the garbage collector clears one or more of the
     uncleared objects in the group (possibly concurrently) by calling
     each’s *note tp_clear: 4ecb. function.  This repeats as long as the
     cyclic isolate still exists and not all of the objects have been
     cleared.


File: python.info,  Node: Cyclic Isolate Destruction,  Next: Functions<14>,  Prev: Life Events,  Up: Object Life Cycle

7.13.2.2 Cyclic Isolate Destruction
...................................

Listed below are the stages of life of a hypothetical *note cyclic
isolate: 55bd. that continues to exist after each member object is
finalized or cleared.  It is a memory leak if a cyclic isolate
progresses through all of these stages; it should vanish once all
objects are cleared, if not sooner.  A cyclic isolate can vanish either
because the reference cycle is broken or because the objects are no
longer isolated due to finalizer resurrection (see *note tp_finalize:
c9f.).

  0. 'Reachable' (not yet a cyclic isolate): All objects are in their
     normal, reachable state.  A reference cycle could exist, but an
     external reference means the objects are not yet isolated.

  1. 'Unreachable but consistent:' The final reference from outside the
     cyclic group of objects has been removed, causing the objects to
     become isolated (thus a cyclic isolate is born).  None of the
     group’s objects have been finalized or cleared yet.  The cyclic
     isolate remains at this stage until some future run of the garbage
     collector (not necessarily the next run because the next run might
     not scan every object).

  2. 'Mix of finalized and not finalized:' Objects in a cyclic isolate
     are finalized one at a time, which means that there is a period of
     time when the cyclic isolate is composed of a mix of finalized and
     non-finalized objects.  Finalization order is unspecified, so it
     can appear random.  A finalized object must behave in a sane manner
     when non-finalized objects interact with it, and a non-finalized
     object must be able to tolerate the finalization of an arbitrary
     subset of its referents.

  3. 'All finalized:' All objects in a cyclic isolate are finalized
     before any of them are cleared.

  4. 'Mix of finalized and cleared:' The objects can be cleared serially
     or concurrently (but with the *note GIL: 164. held); either way,
     some will finish before others.  A finalized object must be able to
     tolerate the clearing of a subset of its referents.  PEP 442(1)
     calls this stage «cyclic trash».

  5. 'Leaked:' If a cyclic isolate still exists after all objects in the
     group have been finalized and cleared, then the objects remain
     indefinitely uncollectable (see *note gc.garbage: 13c9.).  It is a
     bug if a cyclic isolate reaches this stage—it means the *note
     tp_clear: 4ecb. methods of the participating objects have failed to
     break the reference cycle as required.

If *note tp_clear: 4ecb. did not exist, then Python would have no way to
safely break a reference cycle.  Simply destroying an object in a cyclic
isolate would result in a dangling pointer, triggering undefined
behavior when an object referencing the destroyed object is itself
destroyed.  The clearing step makes object destruction a two-phase
process: first *note tp_clear: 4ecb. is called to partially destroy the
objects enough to detangle them from each other, then *note tp_dealloc:
4ea5. is called to complete the destruction.

Unlike clearing, finalization is not a phase of destruction.  A
finalized object must still behave properly by continuing to fulfill its
design contracts.  An object’s finalizer is allowed to execute arbitrary
Python code, and is even allowed to prevent the impending destruction by
adding a reference.  The finalizer is only related to destruction by
call order—if it runs, it runs before destruction, which starts with
*note tp_clear: 4ecb. (if called) and concludes with *note tp_dealloc:
4ea5.

The finalization step is not necessary to safely reclaim the objects in
a cyclic isolate, but its existence makes it easier to design types that
behave in a sane manner when objects are cleared.  Clearing an object
might necessarily leave it in a broken, partially destroyed state—it
might be unsafe to call any of the cleared object’s methods or access
any of its attributes.  With finalization, only finalized objects can
possibly interact with cleared objects; non-finalized objects are
guaranteed to interact with only non-cleared (but potentially finalized)
objects.

To summarize the possible interactions:

   * A non-finalized object might have references to or from
     non-finalized and finalized objects, but not to or from cleared
     objects.

   * A finalized object might have references to or from non-finalized,
     finalized, and cleared objects.

   * A cleared object might have references to or from finalized and
     cleared objects, but not to or from non-finalized objects.

Without any reference cycles, an object can be simply destroyed once its
last reference is deleted; the finalization and clearing steps are not
necessary to safely reclaim unused objects.  However, it can be useful
to automatically call *note tp_finalize: c9f. and *note tp_clear: 4ecb.
before destruction anyway because type design is simplified when all
objects always experience the same series of events regardless of
whether they participated in a cyclic isolate.  Python currently only
calls *note tp_finalize: c9f. and *note tp_clear: 4ecb. as needed to
destroy a cyclic isolate; this may change in a future version.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0442/


File: python.info,  Node: Functions<14>,  Prev: Cyclic Isolate Destruction,  Up: Object Life Cycle

7.13.2.3 Functions
..................

To allocate and free memory, see *note Allocating Objects on the Heap:
55ab.

 -- C Funzione: void PyObject_CallFinalizer (PyObject *op)

     Finalizes the object as described in *note tp_finalize: c9f.  Call
     this function (or *note PyObject_CallFinalizerFromDealloc(): 55bc.)
     instead of calling *note tp_finalize: c9f. directly because this
     function may deduplicate multiple calls to ‘tp_finalize’.
     Currently, calls are only deduplicated if the type supports garbage
     collection (i.e., the *note Py_TPFLAGS_HAVE_GC: 982. flag is set);
     this may change in the future.

     Added in version 3.4.

 -- C Funzione: int PyObject_CallFinalizerFromDealloc (PyObject *op)

     Same as *note PyObject_CallFinalizer(): 55c0. but meant to be
     called at the beginning of the object’s destructor (*note
     tp_dealloc: 4ea5.).  There must not be any references to the
     object.  If the object’s finalizer resurrects the object, this
     function returns -1; no further destruction should happen.
     Otherwise, this function returns 0 and destruction can continue
     normally.

     Added in version 3.4.

     Vedi anche
     ..........

     *note tp_dealloc: 4ea5. for example code.


File: python.info,  Node: Common Object Structures,  Next: Type Object Structures,  Prev: Object Life Cycle,  Up: Object Implementation Support

7.13.3 Common Object Structures
-------------------------------

There are a large number of structures which are used in the definition
of object types for Python.  This section describes these structures and
how they are used.

* Menu:

* Base object types and macros::
* Implementing functions and methods::
* Accessing attributes of extension types::


File: python.info,  Node: Base object types and macros,  Next: Implementing functions and methods,  Up: Common Object Structures

7.13.3.1 Base object types and macros
.....................................

All Python objects ultimately share a small number of fields at the
beginning of the object’s representation in memory.  These are
represented by the *note PyObject: 5df. and *note PyVarObject: 46be.
types, which are defined, in turn, by the expansions of some macros also
used, whether directly or indirectly, in the definition of all other
Python objects.  Additional macros can be found under *note reference
counting: 51bf.

 -- C Tipo: type PyObject
     ' Parte del *note API Limitata: 776.  (Solo alcuni membri fanno
     parte dell'ABI stabile.)'  All object types are extensions of this
     type.  This is a type which contains the information Python needs
     to treat a pointer to an object as an object.  In a normal
     «release» build, it contains only the object’s reference count and
     a pointer to the corresponding type object.  Nothing is actually
     declared to be a *note PyObject: 5df, but every pointer to a Python
     object can be cast to a *note PyObject: 5df.*.

     The members must not be accessed directly; instead use macros such
     as *note Py_REFCNT: 2cf. and *note Py_TYPE: 3c9.

      -- C Membro: *note Py_ssize_t: c57. ob_refcnt
          ' Parte del *note ABI Stabile: 776.'  The object’s reference
          count, as returned by *note Py_REFCNT: 2cf.  Do not use this
          field directly; instead use functions and macros such as
          ‘Py_REFCNT’, *note Py_INCREF(): 790. and *note Py_DecRef():
          5102.

          The field type may be different from ‘Py_ssize_t’, depending
          on build configuration and platform.

      -- C Membro: *note PyTypeObject: c9e. *ob_type
          ' Parte del *note ABI Stabile: 776.'  The object’s type.  Do
          not use this field directly; use *note Py_TYPE: 3c9. and *note
          Py_SET_TYPE(): 985. instead.

 -- C Tipo: type PyVarObject
     ' Parte del *note API Limitata: 776.  (Solo alcuni membri fanno
     parte dell'ABI stabile.)'  An extension of *note PyObject: 5df.
     that adds the *note ob_size: 50f4. field.  This is intended for
     objects that have some notion of 'length'.

     As with ‘PyObject’, the members must not be accessed directly;
     instead use macros such as *note Py_SIZE: 986, *note Py_REFCNT:
     2cf. and *note Py_TYPE: 3c9.

      -- C Membro: *note Py_ssize_t: c57. ob_size
          ' Parte del *note ABI Stabile: 776.'  A size field, whose
          contents should be considered an object’s internal
          implementation detail.

          Do not use this field directly; use *note Py_SIZE: 986.
          instead.

          Object creation functions such as *note PyObject_NewVar():
          b7f. will generally set this field to the requested size
          (number of items).  After creation, arbitrary values can be
          stored in ‘ob_size’ using *note Py_SET_SIZE: 987.

          To get an object’s publicly exposed length, as returned by the
          Python function *note len(): 841, use *note PyObject_Length():
          506c. instead.

 -- C Macro: PyObject_HEAD

     This is a macro used when declaring new types which represent
     objects without a varying length.  The PyObject_HEAD macro expands
     to:

          PyObject ob_base;

     See documentation of *note PyObject: 5df. above.

 -- C Macro: PyObject_VAR_HEAD

     This is a macro used when declaring new types which represent
     objects with a length that varies from instance to instance.  The
     PyObject_VAR_HEAD macro expands to:

          PyVarObject ob_base;

     See documentation of *note PyVarObject: 46be. above.

 -- C Variabile: *note PyTypeObject: c9e. PyBaseObject_Type
     ' Parte del *note ABI Stabile: 776.'  The base class of all other
     objects, the same as *note object: c80. in Python.

 -- C Funzione: int Py_Is (PyObject *x, PyObject *y)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Test if
     the 'x' object is the 'y' object, the same as ‘x is y’ in Python.

     Added in version 3.10.

 -- C Funzione: int Py_IsNone (PyObject *x)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Test if
     an object is the ‘None’ singleton, the same as ‘x is None’ in
     Python.

     Added in version 3.10.

 -- C Funzione: int Py_IsTrue (PyObject *x)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Test if
     an object is the ‘True’ singleton, the same as ‘x is True’ in
     Python.

     Added in version 3.10.

 -- C Funzione: int Py_IsFalse (PyObject *x)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Test if
     an object is the ‘False’ singleton, the same as ‘x is False’ in
     Python.

     Added in version 3.10.

 -- C Funzione: *note PyTypeObject: c9e. *Py_TYPE (PyObject *o)
     'Valore di ritorno: Riferimento preso in prestito.''  Parte del
     *note ABI Stabile: 776. dalla versione 3.14.'  Get the type of the
     Python object 'o'.

     The returned reference is *note borrowed: 3d7. from 'o'.  Do not
     release it with *note Py_DECREF(): 791. or similar.

     Cambiato nella versione 3.11: *note Py_TYPE(): 3c9. is changed to
     an inline static function.  The parameter type is no longer const
     *note PyObject: 5df.*.

 -- C Funzione: int Py_IS_TYPE (PyObject *o, PyTypeObject *type)

     Return non-zero if the object 'o' type is 'type'.  Return zero
     otherwise.  Equivalent to: ‘Py_TYPE(o) == type’.

     Added in version 3.9.

 -- C Funzione: void Py_SET_TYPE (PyObject *o, PyTypeObject *type)

     Set the type of object 'o' to 'type', without any checking or
     reference counting.

     This is a very low-level operation.  Consider instead setting the
     Python attribute *note __class__: 16b4. using *note
     PyObject_SetAttrString(): 1976. or similar.

     Note that assigning an incompatible type can lead to undefined
     behavior.

     If 'type' is a *note heap type: b60, the caller must create a new
     reference to it.  Similarly, if the old type of 'o' is a heap type,
     the caller must release a reference to that type.

     Added in version 3.9.

 -- C Funzione: *note Py_ssize_t: c57. Py_SIZE (PyVarObject *o)

     Get the *note ob_size: 50f4. field of 'o'.

     Cambiato nella versione 3.11: *note Py_SIZE(): 986. is changed to
     an inline static function.  The parameter type is no longer const
     *note PyVarObject: 46be.*.

 -- C Funzione: void Py_SET_SIZE (PyVarObject *o, Py_ssize_t size)

     Set the *note ob_size: 50f4. field of 'o' to 'size'.

     Added in version 3.9.

 -- C Macro: PyObject_HEAD_INIT (type)

     This is a macro which expands to initialization values for a new
     *note PyObject: 5df. type.  This macro expands to:

          _PyObject_EXTRA_INIT
          1, type,

 -- C Macro: PyVarObject_HEAD_INIT (type, size)

     This is a macro which expands to initialization values for a new
     *note PyVarObject: 46be. type, including the *note ob_size: 50f4.
     field.  This macro expands to:

          _PyObject_EXTRA_INIT
          1, type, size,


File: python.info,  Node: Implementing functions and methods,  Next: Accessing attributes of extension types,  Prev: Base object types and macros,  Up: Common Object Structures

7.13.3.2 Implementing functions and methods
...........................................

 -- C Tipo: type PyCFunction
     ' Parte del *note ABI Stabile: 776.'  Type of the functions used to
     implement most Python callables in C. Functions of this type take
     two *note PyObject: 5df.* parameters and return one such value.  If
     the return value is ‘NULL’, an exception shall have been set.  If
     not ‘NULL’, the return value is interpreted as the return value of
     the function as exposed in Python.  The function must return a new
     reference.

     The function signature is:

          PyObject *PyCFunction(PyObject *self,
                                PyObject *args);

 -- C Tipo: type PyCFunctionWithKeywords
     ' Parte del *note ABI Stabile: 776.'  Type of the functions used to
     implement Python callables in C with signature *note METH_VARARGS |
     METH_KEYWORDS: 55ca.  The function signature is:

          PyObject *PyCFunctionWithKeywords(PyObject *self,
                                            PyObject *args,
                                            PyObject *kwargs);

 -- C Tipo: type PyCFunctionFast
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Type of
     the functions used to implement Python callables in C with
     signature *note METH_FASTCALL: 1986.  The function signature is:

          PyObject *PyCFunctionFast(PyObject *self,
                                    PyObject *const *args,
                                    Py_ssize_t nargs);

 -- C Tipo: type PyCFunctionFastWithKeywords
     ' Parte del *note ABI Stabile: 776. dalla versione 3.13.'  Type of
     the functions used to implement Python callables in C with
     signature *note METH_FASTCALL | METH_KEYWORDS: 55cb.  The function
     signature is:

          PyObject *PyCFunctionFastWithKeywords(PyObject *self,
                                                PyObject *const *args,
                                                Py_ssize_t nargs,
                                                PyObject *kwnames);

 -- C Tipo: type PyCMethod

     Type of the functions used to implement Python callables in C with
     signature *note METH_METHOD | METH_FASTCALL | METH_KEYWORDS: 19f1.
     The function signature is:

          PyObject *PyCMethod(PyObject *self,
                              PyTypeObject *defining_class,
                              PyObject *const *args,
                              Py_ssize_t nargs,
                              PyObject *kwnames)

     Added in version 3.9.

 -- C Tipo: type PyMethodDef
     ' Parte del *note ABI Stabile: 776. (inclusi tutti i membri).'
     Structure used to describe a method of an extension type.  This
     structure has four fields:

      -- C Membro: const char *ml_name

          Name of the method.

      -- C Membro: *note PyCFunction: 167f. ml_meth

          Pointer to the C implementation.

      -- C Membro: int ml_flags

          Flags bits indicating how the call should be constructed.

      -- C Membro: const char *ml_doc

          Points to the contents of the docstring.

The *note ml_meth: 55cc. is a C function pointer.  The functions may be
of different types, but they always return *note PyObject: 5df.*.  If
the function is not of the *note PyCFunction: 167f, the compiler will
require a cast in the method table.  Even though *note PyCFunction:
167f. defines the first parameter as *note PyObject: 5df.*, it is common
that the method implementation uses the specific C type of the 'self'
object.

The *note ml_flags: 55cd. field is a bitfield which can include the
following flags.  The individual flags indicate either a calling
convention or a binding convention.

There are these calling conventions:

 -- C Macro: METH_VARARGS
     ' Parte del *note ABI Stabile: 776.'  This is the typical calling
     convention, where the methods have the type *note PyCFunction:
     167f.  The function expects two *note PyObject: 5df.* values.  The
     first one is the 'self' object for methods; for module functions,
     it is the module object.  The second parameter (often called
     'args') is a tuple object representing all arguments.  This
     parameter is typically processed using *note PyArg_ParseTuple():
     3c1. or *note PyArg_UnpackTuple(): 170d.

 -- C Macro: METH_KEYWORDS

     Can only be used in certain combinations with other flags: *note
     METH_VARARGS | METH_KEYWORDS: 55ca, *note METH_FASTCALL |
     METH_KEYWORDS: 55cb. and *note METH_METHOD | METH_FASTCALL |
     METH_KEYWORDS: 19f1.

*note METH_VARARGS: 170f. | *note METH_KEYWORDS: 4e8b.

     Methods with these flags must be of type *note
     PyCFunctionWithKeywords: 4f63.  The function expects three
     parameters: 'self', 'args', 'kwargs' where 'kwargs' is a dictionary
     of all the keyword arguments or possibly ‘NULL’ if there are no
     keyword arguments.  The parameters are typically processed using
     *note PyArg_ParseTupleAndKeywords(): 624.

 -- C Macro: METH_FASTCALL
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Fast
     calling convention supporting only positional arguments.  The
     methods have the type *note PyCFunctionFast: 4f61.  The first
     parameter is 'self', the second parameter is a C array of *note
     PyObject: 5df.* values indicating the arguments and the third
     parameter is the number of arguments (the length of the array).

     Added in version 3.7.

     Cambiato nella versione 3.10: ‘METH_FASTCALL’ is now part of the
     *note stable ABI: 4f35.

*note METH_FASTCALL: 1986. | *note METH_KEYWORDS: 4e8b.

     Extension of *note METH_FASTCALL: 1986. supporting also keyword
     arguments, with methods of type *note PyCFunctionFastWithKeywords:
     4f62.  Keyword arguments are passed the same way as in the *note
     vectorcall protocol: 775.: there is an additional fourth *note
     PyObject: 5df.* parameter which is a tuple representing the names
     of the keyword arguments (which are guaranteed to be strings) or
     possibly ‘NULL’ if there are no keywords.  The values of the
     keyword arguments are stored in the 'args' array, after the
     positional arguments.

     Added in version 3.7.

 -- C Macro: METH_METHOD
     ' Parte del *note ABI Stabile: 776. dalla versione 3.7.'  Can only
     be used in the combination with other flags: *note METH_METHOD |
     METH_FASTCALL | METH_KEYWORDS: 19f1.

*note METH_METHOD: b6a. | *note METH_FASTCALL: 1986. | *note METH_KEYWORDS: 4e8b.

     Extension of *note METH_FASTCALL | METH_KEYWORDS: 55cb. supporting
     the 'defining class', that is, the class that contains the method
     in question.  The defining class might be a superclass of
     ‘Py_TYPE(self)’.

     The method needs to be of type *note PyCMethod: 969, the same as
     for ‘METH_FASTCALL | METH_KEYWORDS’ with ‘defining_class’ argument
     added after ‘self’.

     Added in version 3.9.

 -- C Macro: METH_NOARGS
     ' Parte del *note ABI Stabile: 776.'  Methods without parameters
     don’t need to check whether arguments are given if they are listed
     with the *note METH_NOARGS: 16db. flag.  They need to be of type
     *note PyCFunction: 167f.  The first parameter is typically named
     'self' and will hold a reference to the module or object instance.
     In all cases the second parameter will be ‘NULL’.

     The function must have 2 parameters.  Since the second parameter is
     unused, *note Py_UNUSED: 1a72. can be used to prevent a compiler
     warning.

 -- C Macro: METH_O
     ' Parte del *note ABI Stabile: 776.'  Methods with a single object
     argument can be listed with the *note METH_O: 170e. flag, instead
     of invoking *note PyArg_ParseTuple(): 3c1. with a ‘"O"’ argument.
     They have the type *note PyCFunction: 167f, with the 'self'
     parameter, and a *note PyObject: 5df.* parameter representing the
     single argument.

These two constants are not used to indicate the calling convention but
the binding when use with methods of classes.  These may not be used for
functions defined for modules.  At most one of these flags may be set
for any given method.

 -- C Macro: METH_CLASS
     ' Parte del *note ABI Stabile: 776.'

     The method will be passed the type object as the first parameter
     rather than an instance of the type.  This is used to create 'class
     methods', similar to what is created when using the *note
     classmethod(): 48f. built-in function.

 -- C Macro: METH_STATIC
     ' Parte del *note ABI Stabile: 776.'

     The method will be passed ‘NULL’ as the first parameter rather than
     an instance of the type.  This is used to create 'static methods',
     similar to what is created when using the *note staticmethod():
     453. built-in function.

One other constant controls whether a method is loaded in place of
another definition with the same method name.

 -- C Macro: METH_COEXIST
     ' Parte del *note ABI Stabile: 776.'  The method will be loaded in
     place of existing definitions.  Without 'METH_COEXIST', the default
     is to skip repeated definitions.  Since slot wrappers are loaded
     before the method table, the existence of a 'sq_contains' slot, for
     example, would generate a wrapped method named *note
     __contains__(): 15c1. and preclude the loading of a corresponding
     PyCFunction with the same name.  With the flag defined, the
     PyCFunction will be loaded in place of the wrapper object and will
     co-exist with the slot.  This is helpful because calls to
     PyCFunctions are optimized more than wrapper object calls.

 -- C Variabile: *note PyTypeObject: c9e. PyCMethod_Type

     The type object corresponding to Python C method objects.  This is
     available as *note types.BuiltinMethodType: 29ce. in the Python
     layer.

 -- C Funzione: int PyCMethod_Check (PyObject *op)

     Return true if 'op' is an instance of the *note PyCMethod_Type:
     55cf. type or a subtype of it.  This function always succeeds.

 -- C Funzione: int PyCMethod_CheckExact (PyObject *op)

     This is the same as *note PyCMethod_Check(): 55d0, but does not
     account for subtypes.

 -- C Funzione: *note PyObject: 5df. *PyCMethod_New (PyMethodDef *ml,
          PyObject *self, PyObject *module, PyTypeObject *cls)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.9.'  Turn 'ml' into a Python *note
     callable: 2d61. object.  The caller must ensure that 'ml' outlives
     the *note callable: 2d61.  Typically, 'ml' is defined as a static
     variable.

     The 'self' parameter will be passed as the 'self' argument to the C
     function in ‘ml->ml_meth’ when invoked.  'self' can be ‘NULL’.

     The *note callable: 2d61. object’s ‘__module__’ attribute can be
     set from the given 'module' argument.  'module' should be a Python
     string, which will be used as name of the module the function is
     defined in.  If unavailable, it can be set to *note None: 886. or
     ‘NULL’.

     Vedi anche
     ..........

     *note function.__module__: 2331.

     The 'cls' parameter will be passed as the 'defining_class' argument
     to the C function.  Must be set if *note METH_METHOD: b6a. is set
     on ‘ml->ml_flags’.

     Added in version 3.9.

 -- C Variabile: *note PyTypeObject: c9e. PyCFunction_Type
     ' Parte del *note ABI Stabile: 776.'  The type object corresponding
     to Python C function objects.  This is available as *note
     types.BuiltinFunctionType: 29cd. in the Python layer.

 -- C Funzione: int PyCFunction_Check (PyObject *op)

     Return true if 'op' is an instance of the *note PyCFunction_Type:
     4f67. type or a subtype of it.  This function always succeeds.

 -- C Funzione: int PyCFunction_CheckExact (PyObject *op)

     This is the same as *note PyCFunction_Check(): 55d2, but does not
     account for subtypes.

 -- C Funzione: *note PyObject: 5df. *PyCFunction_NewEx (PyMethodDef
          *ml, PyObject *self, PyObject *module)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776.'  Equivalent to ‘PyCMethod_New(ml, self, module,
     NULL)’.

 -- C Funzione: *note PyObject: 5df. *PyCFunction_New (PyMethodDef *ml,
          PyObject *self)
     'Valore di ritorno: Nuovo riferimento.''  Parte del *note ABI
     Stabile: 776. dalla versione 3.4.'  Equivalent to
     ‘PyCMethod_New(ml, self, NULL, NULL)’.

 -- C Funzione: int PyCFunction_GetFlags (PyObject *func)
     ' Parte del *note ABI Stabile: 776.'  Get the function’s flags on
     'func' as they were passed to *note ml_flags: 55cd.

     If 'func' is not a C function object, this fails with an exception.
     'func' must not be ‘NULL’.

     This function returns the function’s flags on success, and ‘-1’
     with an exception set on failure.

 -- C Funzione: int PyCFunction_GET_FLAGS (PyObject *func)

     This is the same as *note PyCFunction_GetFlags(): 4f64, but without
     error or type checking.

 -- C Funzione: *note PyCFunction: 167f. PyCFunction_GetFunction
          (PyObject *func)
     ' Parte del *note ABI Stabile: 776.'  Get the function pointer on
     'func' as it was passed to *note ml_meth: 55cc.

     If 'func' is not a C function object, this fails with an exception.
     'func' must not be ‘NULL’.

     This function returns the function pointer on success, and ‘NULL’
     with an exception set on failure.

 -- C Funzione: int PyCFunction_GET_FUNCTION (PyObject *func)

     This is the same as *note PyCFunction_GetFunction(): 4f65, but
     without error or type checking.

 -- C Funzione: *note PyObject: 5df. *PyCFunction_GetSelf (PyObject
          *func)
     ' Parte del *note ABI Stabile: 776.'  Get the «self» object on
     'func'.  This is the object that would be passed to the first
     argument of a *note PyCFunction: 167f.  For C function objects
     created through a *note PyMethodDef: 16de. on a *note PyModuleDef:
     b76, this is the resulting module object.

     If 'func' is not a C function object, this fails with an exception.
     'func' must not be ‘NULL’.

     This function returns a *note borrowed reference: 3d7. to the
     «self» object on success, and ‘NULL’ with an exception set on
     failure.

 -- C Funzione: *note PyObject: 5df. *PyCFunction_GET_SELF (PyObject
          *func)

     This is the same as *note PyCFunction_GetSelf(): 4f66, but without
     error or type checking.


File: python.info,  Node: Accessing attributes of extension types,  Prev: Implementing functions and methods,  Up: Common Object Structures

7.13.3.3 Accessing attributes of extension types
................................................

 -- C Tipo: type PyMemberDef
     ' Parte del *note ABI Stabile: 776. (inclusi tutti i membri).'
     Structure which describes an attribute of a type which corresponds
     to a C struct member.  When defining a class, put a NULL-terminated
     array of these structures in the *note tp_members: 4ebb. slot.

     Its fields are, in order:

      -- C Membro: const char *name

          Name of the member.  A NULL value marks the end of a
          ‘PyMemberDef[]’ array.

          The string should be static, no copy is made of it.

      -- C Membro: int type

          The type of the member in the C struct.  See *note Member
          types: 19d8. for the possible values.

      -- C Membro: *note Py_ssize_t: c57. offset

          The offset in bytes that the member is located on the type’s
          object struct.

      -- C Membro: int flags

          Zero or more of the *note Member flags: 55da, combined using
          bitwise OR.

      -- C Membro: const char *doc

          The docstring, or NULL. The string should be static, no copy
          is made of it.  Typically, it is defined using *note
          PyDoc_STR: 1b7e.

     By default (when *note flags: 4ed4. is ‘0’), members allow both
     read and write access.  Use the *note Py_READONLY: 7af. flag for
     read-only access.  Certain types, like *note Py_T_STRING: 511a,
     imply *note Py_READONLY: 7af.  Only *note Py_T_OBJECT_EX: 7b2. (and
     legacy *note T_OBJECT: 7b1.) members can be deleted.  For
     heap-allocated types (created using *note PyType_FromSpec(): 79e.
     or similar), ‘PyMemberDef’ may contain a definition for the special
     member ‘"__vectorcalloffset__"’, corresponding to *note
     tp_vectorcall_offset: 526e. in type objects.  This member must be
     defined with ‘Py_T_PYSSIZET’, and either ‘Py_READONLY’ or
     ‘Py_READONLY | Py_RELATIVE_OFFSET’.  For example:

          static PyMemberDef spam_type_members[] = {
              {"__vectorcalloffset__", Py_T_PYSSIZET,
               offsetof(Spam_object, vectorcall), Py_READONLY},
              {NULL}  /* Sentinel */
          };

     (You may need to ‘#include <stddef.h>’ for ‘offsetof()’.)

     The legacy offsets *note tp_dictoffset: 52c5. and *note
     tp_weaklistoffset: b81. can be defined similarly using
     ‘"__dictoffset__"’ and ‘"__weaklistoffset__"’ members, but
     extensions are strongly encouraged to use *note
     Py_TPFLAGS_MANAGED_DICT: 60f. and *note Py_TPFLAGS_MANAGED_WEAKREF:
     77d. instead.

     Cambiato nella versione 3.12: ‘PyMemberDef’ is always available.
     Previously, it required including ‘"structmember.h"’.

     Cambiato nella versione 3.14: *note Py_RELATIVE_OFFSET: 771. is now
     allowed for ‘"__vectorcalloffset__"’, ‘"__dictoffset__"’ and
     ‘"__weaklistoffset__"’.

 -- C Funzione: *note PyObject: 5df. *PyMember_GetOne (const char
          *obj_addr, struct PyMemberDef *m)
     ' Parte del *note ABI Stabile: 776.'  Get an attribute belonging to
     the object at address 'obj_addr'.  The attribute is described by
     ‘PyMemberDef’ 'm'.  Returns ‘NULL’ on error.

     Cambiato nella versione 3.12: ‘PyMember_GetOne’ is always
     available.  Previously, it required including ‘"structmember.h"’.

 -- C Funzione: int PyMember_SetOne (char *obj_addr, struct PyMemberDef
          *m, PyObject *o)
     ' Parte del *note ABI Stabile: 776.'  Set an attribute belonging to
     the object at address 'obj_addr' to object 'o'.  The attribute to
     set is described by ‘PyMemberDef’ 'm'.  Returns ‘0’ if successful
     and a negative value on failure.

     Cambiato nella versione 3.12: ‘PyMember_SetOne’ is always
     available.  Previously, it required including ‘"structmember.h"’.

* Menu:

* Member flags::
* Member types::
* Defining Getters and Setters::


File: python.info,  Node: Member flags,  Next: Member types,  Up: Accessing attributes of extension types

7.13.3.4 Member flags
.....................

The following flags can be used with *note PyMemberDef.flags: 4ed4.:

 -- C Macro: Py_READONLY
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Not
     writable.

 -- C Macro: Py_AUDIT_READ
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'  Emit an
     ‘object.__getattr__’ *note audit event: 1bfb. before reading.

 -- C Macro: Py_RELATIVE_OFFSET
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'
     Indicates that the *note offset: 55d9. of this ‘PyMemberDef’ entry
     indicates an offset from the subclass-specific data, rather than
     from ‘PyObject’.

     Can only be used as part of the *note Py_tp_members: 516d. *note
     slot: 50b4. when creating a class using negative *note basicsize:
     76b.  It is mandatory in that case.  When setting *note tp_members:
     4ebb. from the slot during class creation, Python clears the flag
     and sets *note PyMemberDef.offset: 55d9. to the offset from the
     ‘PyObject’ struct.

Cambiato nella versione 3.10: The ‘RESTRICTED’, ‘READ_RESTRICTED’ and
‘WRITE_RESTRICTED’ macros available with ‘#include "structmember.h"’ are
deprecated.  ‘READ_RESTRICTED’ and ‘RESTRICTED’ are equivalent to *note
Py_AUDIT_READ: 7b0.; ‘WRITE_RESTRICTED’ does nothing.

Cambiato nella versione 3.12: The ‘READONLY’ macro was renamed to *note
Py_READONLY: 7af.  The ‘PY_AUDIT_READ’ macro was renamed with the ‘Py_’
prefix.  The new names are now always available.  Previously, these
required ‘#include "structmember.h"’.  The header is still available and
it provides the old names.


File: python.info,  Node: Member types,  Next: Defining Getters and Setters,  Prev: Member flags,  Up: Accessing attributes of extension types

7.13.3.5 Member types
.....................

*note PyMemberDef.type: 4ed3. can be one of the following macros
corresponding to various C types.  When the member is accessed in
Python, it will be converted to the equivalent Python type.  When it is
set from Python, it will be converted back to the C type.  If that is
not possible, an exception such as *note TypeError: 198. or *note
ValueError: 2ec. is raised.

Unless marked (D), attributes defined this way cannot be deleted using
e.g.  *note del: 1b07. or *note delattr(): 2593.

Macro name                           C type                            Python type
                                                                       
--------------------------------------------------------------------------------------------------
                                                                       
 -- C Macro: Py_T_BYTE               char                              *note int: 19b.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_SHORT              short                             *note int: 19b.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_INT                int                               *note int: 19b.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_LONG               long                              *note int: 19b.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_LONGLONG           long long                         *note int: 19b.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_UBYTE              unsigned char                     *note int: 19b.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_UINT               unsigned int                      *note int: 19b.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_USHORT             unsigned short                    *note int: 19b.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_ULONG              unsigned long                     *note int: 19b.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_ULONGLONG          unsigned long long                *note int: 19b.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_PYSSIZET           *note Py_ssize_t: c57.            *note int: 19b.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_FLOAT              float                             *note float: 196.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_DOUBLE             double                            *note float: 196.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_BOOL               char (written as 0 or 1)          *note bool: 3c3.
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_STRING             const char* (*)                   *note str: 169. (RO)
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_STRING_INPLACE     const char[] (*)                  *note str: 169. (RO)
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_CHAR               char (0-127)                      *note str: 169. (**)
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

 -- C Macro: Py_T_OBJECT_EX          *note PyObject: 5df.*             *note object: c80. (D)
     ' Parte del                                                       
     *note ABI Stabile: 776. dalla
     versione 3.12.'

     (*): Zero-terminated, UTF8-encoded C string.  With ‘Py_T_STRING’
     the C representation is a pointer; with ‘Py_T_STRING_INPLACE’ the
     string is stored directly in the structure.

     (**): String of length 1.  Only ASCII is accepted.

     (RO): Implies *note Py_READONLY: 7af.

     (D): Can be deleted, in which case the pointer is set to ‘NULL’.
     Reading a ‘NULL’ pointer raises *note AttributeError: 5f0.

Added in version 3.12: In previous versions, the macros were only
available with ‘#include "structmember.h"’ and were named without the
‘Py_’ prefix (e.g.  as ‘T_INT’).  The header is still available and
contains the old names, along with the following deprecated types:

 -- C Macro: T_OBJECT

     Like ‘Py_T_OBJECT_EX’, but ‘NULL’ is converted to ‘None’.  This
     results in surprising behavior in Python: deleting the attribute
     effectively sets it to ‘None’.

 -- C Macro: T_NONE

     Always ‘None’.  Must be used with *note Py_READONLY: 7af.


File: python.info,  Node: Defining Getters and Setters,  Prev: Member types,  Up: Accessing attributes of extension types

7.13.3.6 Defining Getters and Setters
.....................................

 -- C Tipo: type PyGetSetDef
     ' Parte del *note ABI Stabile: 776. (inclusi tutti i membri).'
     Structure to define property-like access for a type.  See also
     description of the *note PyTypeObject.tp_getset: 4ec0. slot.

      -- C Membro: const char *name

          attribute name

      -- C Membro: *note getter: 5180. get

          C function to get the attribute.

      -- C Membro: *note setter: 518e. set

          Optional C function to set or delete the attribute.  If
          ‘NULL’, the attribute is read-only.

      -- C Membro: const char *doc

          optional docstring

      -- C Membro: void *closure

          Optional user data pointer, providing additional data for
          getter and setter.

 -- C Tipo: typedef *note PyObject: 5df. *(*getter)(*note PyObject:
          5df.*, void*)
     ' Parte del *note ABI Stabile: 776.'  The ‘get’ function takes one
     *note PyObject: 5df.* parameter (the instance) and a user data
     pointer (the associated ‘closure’):

     It should return a new reference on success or ‘NULL’ with a set
     exception on failure.

 -- C Tipo: typedef int (*setter)(*note PyObject: 5df.*, *note PyObject:
          5df.*, void*)
     ' Parte del *note ABI Stabile: 776.'  ‘set’ functions take two
     *note PyObject: 5df.* parameters (the instance and the value to be
     set) and a user data pointer (the associated ‘closure’):

     In case the attribute should be deleted the second parameter is
     ‘NULL’.  Should return ‘0’ on success or ‘-1’ with a set exception
     on failure.


File: python.info,  Node: Type Object Structures,  Next: Supporting Cyclic Garbage Collection,  Prev: Common Object Structures,  Up: Object Implementation Support

7.13.4 Type Object Structures
-----------------------------

Perhaps one of the most important structures of the Python object system
is the structure that defines a new type: the *note PyTypeObject: c9e.
structure.  Type objects can be handled using any of the ‘PyObject_*’ or
‘PyType_*’ functions, but do not offer much that’s interesting to most
Python applications.  These objects are fundamental to how objects
behave, so they are very important to the interpreter itself and to any
extension module that implements new types.

Type objects are fairly large compared to most of the standard types.
The reason for the size is that each type object stores a large number
of values, mostly C function pointers, each of which implements a small
part of the type’s functionality.  The fields of the type object are
examined in detail in this section.  The fields will be described in the
order in which they occur in the structure.

In addition to the following quick reference, the *note Examples: 55e7.
section provides at-a-glance insight into the meaning and use of *note
PyTypeObject: c9e.

* Menu:

* Quick Reference::
* PyTypeObject Definition::
* PyObject Slots::
* PyVarObject Slots::
* PyTypeObject Slots::
* Static Types::
* Heap Types::
* Number Object Structures::
* Mapping Object Structures::
* Sequence Object Structures::
* Buffer Object Structures::
* Async Object Structures::
* Slot Type typedefs::
* Examples: Examples<39>.


File: python.info,  Node: Quick Reference,  Next: PyTypeObject Definition,  Up: Type Object Structures

7.13.4.1 Quick Reference
........................

* Menu:

* «tp slots»::
* sub-slots::
* slot typedefs::


File: python.info,  Node: «tp slots»,  Next: sub-slots,  Up: Quick Reference

7.13.4.2 «tp slots»
...................

PyTypeObject Slot      *note Type: 55eb.      special                Info
(1)                                           methods/attrs          (2)
                                                                     
---------------------------------------------------------------------------------------------
                                                                     
O                      T                      D                      I
                                                                     
                                                                                       
<R>                    const char *           __name__               X     X
*note tp_name: 1c98.                                                       

*note tp_basicsize: b80.*note Py_ssize_t: c57.                       X     X           X
                                                                                       
                                                                                       
*note tp_itemsize: 23a1.*note Py_ssize_t: c57.                             X           X
                                                                                       
                                                                                       
*note tp_dealloc: 4ea5.*note destructor: 517b.                       X     X           X
                                                                                       
                                                                                       
*note tp_vectorcall_offset: 526e.*note Py_ssize_t: c57.                    X           X
                                                                                       
                                                                                       
(*note tp_getattr: 4ed6.)*note getattrfunc: 517c.__getattribute__,                     G
                                              __getattr__                              
                                              
                                                                                       
(*note tp_setattr: 4ed7.)*note setattrfunc: 518c.__setattr__,                          G
                                              __delattr__                              
                                              
                                                                                       
*note tp_as_async: 10d1.*note PyAsyncMethods: 52c3.*note sub-slots: 55ec.              %
                       *                                                               
                       
                                                                                       
*note tp_repr: 4ecd.   *note reprfunc: 518a.  __repr__               X     X           X
                                                                                       
                                                                                       
*note tp_as_number: b84.*note PyNumberMethods: 1625.*note sub-slots: 55ec.             %
                       *                                                               
                       
                                                                                       
*note tp_as_sequence: 55ed.*note PySequenceMethods: 4edd.*note sub-slots: 55ec.        %
                       *                                                               
                       
                                                                                       
*note tp_as_mapping: 55ee.*note PyMappingMethods: 4ede.*note sub-slots: 55ec.          %
                       *                                                               
                       
                                                                                       
*note tp_hash: 4edf.   *note hashfunc: 5181.  __hash__               X                 G
                                                                                       
                                                                                       
*note tp_call: 77c.    *note ternaryfunc: 5191.__call__                    X           X
                                                                                       
                                                                                       
*note tp_str: 4ece.    *note reprfunc: 518a.  __str__                X                 X
                                                                                       
                                                                                       
*note tp_getattro: 1a4c.*note getattrofunc: 517d.__getattribute__,   X     X           G
                                              __getattr__                              
                                              
                                                                                       
*note tp_setattro: 4ed1.*note setattrofunc: 518d.__setattr__,        X     X           G
                                              __delattr__                              
                                              
                                                                                       
*note tp_as_buffer: b82.*note PyBufferProcs: 52ca.*note sub-slots: 55ec.               %
                       *                                                               
                       
                                                                                       
*note tp_flags: 1c59.  unsigned long                                 X     X           ?
                                                                                       
                                                                                       
*note tp_doc: 4eb4.    const char *           __doc__                X     X
                                                                           
                                                                                       
*note tp_traverse: 983.*note traverseproc: 5192.                           X           G
                                                                                       
                                                                                       
*note tp_clear: 4ecb.  *note inquiry: 5183.                                X           G
                                                                                       
                                                                                       
*note tp_richcompare: 4ed9.*note richcmpfunc: 518b.__lt__, __le__,   X                 G
                                              __eq__, __ne__,                          
                                              __gt__, __ge__
                                              
                                                                                       
(*note tp_weaklistoffset: b81.)*note Py_ssize_t: c57.                      X           ?
                                                                                       
                                                                                       
*note tp_iter: 16f6.   *note getiterfunc: 517f.__iter__                                X
                                                                                       
                                                                                       
*note tp_iternext: 16f7.*note iternextfunc: 5184.__next__                              X
                                                                                       
                                                                                       
*note tp_methods: 4ebd.*note PyMethodDef: 16de.                      X     X
                       []                                                  
                       
                                                                                       
*note tp_members: 4ebb.*note PyMemberDef: 772.                             X
                       []                                                  
                       
                                                                                       
*note tp_getset: 4ec0. *note PyGetSetDef: db4.                       X     X
                       []                                                  
                       
                                                                                       
*note tp_base: 235c.   *note PyTypeObject: c9e.__base__                          X
                       *                                                         
                       
                                                                                       
*note tp_dict: 1a74.   *note PyObject: 5df.   __dict__                           ?
                       *                                                         
                       
                                                                                       
*note tp_descr_get: 55ef.*note descrgetfunc: 5179.__get__                              X
                                                                                       
                                                                                       
*note tp_descr_set: 1c9c.*note descrsetfunc: 517a.__set__, __delete__                  X
                                                                                       
                                                                                       
(*note tp_dictoffset: 52c5.)*note Py_ssize_t: c57.                         X           ?
                                                                                       
                                                                                       
*note tp_init: 7a2.    *note initproc: 5182.  __init__               X     X           X
                                                                                       
                                                                                       
*note tp_alloc: 4eb9.  *note allocfunc: 5177.                        X           ?     ?
                                                                                       
                                                                                       
*note tp_new: 7a0.     *note newfunc: 5186.   __new__                X     X     ?     ?
                                                                                       
                                                                                       
*note tp_free: 4eb8.   *note freefunc: 5422.                         X     X     ?     ?
                                                                                       
                                                                                       
*note tp_is_gc: 55f0.  *note inquiry: 5183.                                X           X
                                                                                       
                                                                                       
<*note tp_bases: 55f1.>*note PyObject: 5df.   __bases__                          ~
                       *                                                         
                       
                                                                                       
<*note tp_mro: 52c7.>  *note PyObject: 5df.   __mro__                            ~
                       *                                                         
                       
                                                                                       
[*note tp_cache: 52c8.]*note PyObject: 5df.
                       *
                       
                                                                                       
[*note tp_subclasses: 793.]void *             __subclasses__
                                              
                                                                                       
[*note tp_weaklist: 52c9.]*note PyObject: 5df.
                       *
                       
                                                                                       
(*note tp_del: 55f2.)  *note destructor: 517b.
                       
                                                                                       
[*note tp_version_tag: 55f3.]unsigned int
                       
                                                                                       
*note tp_finalize: c9f.*note destructor: 517b.__del__                                  X
                                                                                       
                                                                                       
*note tp_vectorcall: 1972.*note vectorcallfunc: 77a.
                       
                                                                                       
[*note tp_watched: 55f4.]unsigned char
                       

   ---------- Footnotes ----------

   (1) '()': A slot name in parentheses indicates it is (effectively)
deprecated.

'<>': Names in angle brackets should be initially set to ‘NULL’ and
treated as read-only.

'[]': Names in square brackets are for internal use only.

'<R>' (as a prefix) means the field is required (must be non-‘NULL’).

   (2) Columns:

'«O»': set on *note PyBaseObject_Type: 4f4d.

'«T»': set on *note PyType_Type: 770.

'«D»': default (if slot is set to ‘NULL’)

     X - PyType_Ready sets this value if it is NULL
     ~ - PyType_Ready always sets this value (it should be NULL)
     ? - PyType_Ready may set this value depending on other slots

     Also see the inheritance column ("I").

'«I»': inheritance

     X - type slot is inherited via *PyType_Ready* if defined with a *NULL* value
     % - the slots of the sub-struct are inherited individually
     G - inherited, but only in combination with other slots; see the slot's description
     ? - it's complicated; see the slot's description

Note that some slots are effectively inherited through the normal
attribute lookup chain.


File: python.info,  Node: sub-slots,  Next: slot typedefs,  Prev: «tp slots»,  Up: Quick Reference

7.13.4.3 sub-slots
..................

Slot                           *note Type: 55eb.     special
                                                     methods
                                                     
----------------------------------------------------------------------
                                                     
*note am_await: 55f6.          *note unaryfunc: 5193.__await__
                                                     
                                                     
*note am_aiter: 55f7.          *note unaryfunc: 5193.__aiter__
                                                     
                                                     
*note am_anext: 55f8.          *note unaryfunc: 5193.__anext__
                                                     
                                                     
*note am_send: 55f9.           *note sendfunc: 55fa.
                               
                                                     
                                                     
*note nb_add: 52bb.            *note binaryfunc: 5178.__add__
                                                     __radd__
                                                     
                                                     
*note nb_inplace_add: 55fb.    *note binaryfunc: 5178.__iadd__
                                                     
                                                     
*note nb_subtract: 55fc.       *note binaryfunc: 5178.__sub__
                                                     __rsub__
                                                     
                                                     
*note nb_inplace_subtract: 55fd.*note binaryfunc: 5178.__isub__
                                                     
                                                     
*note nb_multiply: 55fe.       *note binaryfunc: 5178.__mul__
                                                     __rmul__
                                                     
                                                     
*note nb_inplace_multiply: 55ff.*note binaryfunc: 5178.__imul__
                                                     
                                                     
*note nb_remainder: 5600.      *note binaryfunc: 5178.__mod__
                                                     __rmod__
                                                     
                                                     
*note nb_inplace_remainder: 5601.*note binaryfunc: 5178.__imod__
                                                     
                                                     
*note nb_divmod: 5602.         *note binaryfunc: 5178.__divmod__
                                                     __rdivmod__
                                                     
                                                     
*note nb_power: 5603.          *note ternaryfunc: 5191.__pow__
                                                     __rpow__
                                                     
                                                     
*note nb_inplace_power: 5604.  *note ternaryfunc: 5191.__ipow__
                                                     
                                                     
*note nb_negative: 5605.       *note unaryfunc: 5193.__neg__
                                                     
                                                     
*note nb_positive: 5606.       *note unaryfunc: 5193.__pos__
                                                     
                                                     
*note nb_absolute: 5607.       *note unaryfunc: 5193.__abs__
                                                     
                                                     
*note nb_bool: 5608.           *note inquiry: 5183.  __bool__
                                                     
                                                     
*note nb_invert: 5609.         *note unaryfunc: 5193.__invert__
                                                     
                                                     
*note nb_lshift: 560a.         *note binaryfunc: 5178.__lshift__
                                                     __rlshift__
                                                     
                                                     
*note nb_inplace_lshift: 560b. *note binaryfunc: 5178.__ilshift__
                                                     
                                                     
*note nb_rshift: 560c.         *note binaryfunc: 5178.__rshift__
                                                     __rrshift__
                                                     
                                                     
*note nb_inplace_rshift: 560d. *note binaryfunc: 5178.__irshift__
                                                     
                                                     
*note nb_and: 560e.            *note binaryfunc: 5178.__and__
                                                     __rand__
                                                     
                                                     
*note nb_inplace_and: 560f.    *note binaryfunc: 5178.__iand__
                                                     
                                                     
*note nb_xor: 5610.            *note binaryfunc: 5178.__xor__
                                                     __rxor__
                                                     
                                                     
*note nb_inplace_xor: 5611.    *note binaryfunc: 5178.__ixor__
                                                     
                                                     
*note nb_or: 5612.             *note binaryfunc: 5178.__or__ __ror__
                                                     
                                                     
*note nb_inplace_or: 5613.     *note binaryfunc: 5178.__ior__
                                                     
                                                     
*note nb_int: 5614.            *note unaryfunc: 5193.__int__
                                                     
                                                     
*note nb_reserved: 5615.       void *
                               
                                                     
*note nb_float: 5616.          *note unaryfunc: 5193.__float__
                                                     
                                                     
*note nb_floor_divide: 5617.   *note binaryfunc: 5178.__floordiv__
                                                     
                                                     
*note nb_inplace_floor_divide: 5618.*note binaryfunc: 5178.__ifloordiv__
                                                     
                                                     
*note nb_true_divide: 5619.    *note binaryfunc: 5178.__truediv__
                                                     
                                                     
*note nb_inplace_true_divide: 561a.*note binaryfunc: 5178.__itruediv__
                                                     
                                                     
*note nb_index: 1624.          *note unaryfunc: 5193.__index__
                                                     
                                                     
*note nb_matrix_multiply: 561b.*note binaryfunc: 5178.__matmul__
                                                     __rmatmul__
                                                     
                                                     
*note nb_inplace_matrix_multiply: 561c.*note binaryfunc: 5178.__imatmul__
                                                     
                                                     
                                                     
*note mp_length: 561d.         *note lenfunc: 5185.  __len__
                                                     
                                                     
*note mp_subscript: 1cde.      *note binaryfunc: 5178.__getitem__
                                                     
                                                     
*note mp_ass_subscript: 561e.  *note objobjargproc: 5187.__setitem__,
                                                     __delitem__
                                                     
                                                     
                                                     
*note sq_length: 52c4.         *note lenfunc: 5185.  __len__
                                                     
                                                     
*note sq_concat: 561f.         *note binaryfunc: 5178.__add__
                                                     
                                                     
*note sq_repeat: 5620.         *note ssizeargfunc: 518f.__mul__
                                                     
                                                     
*note sq_item: 1cdd.           *note ssizeargfunc: 518f.__getitem__
                                                     
                                                     
*note sq_ass_item: 5621.       *note ssizeobjargproc: 5190.__setitem__
                                                     __delitem__
                                                     
                                                     
*note sq_contains: 5622.       *note objobjproc: 5188.__contains__
                                                     
                                                     
*note sq_inplace_concat: 5623. *note binaryfunc: 5178.__iadd__
                                                     
                                                     
*note sq_inplace_repeat: 5624. *note ssizeargfunc: 518f.__imul__
                                                     
                                                     
                                                     
*note bf_getbuffer: 967.       *note getbufferproc(): 517e.__buffer__
                                                     
                                                     
*note bf_releasebuffer: 968.   *note releasebufferproc(): 5189.__release_buffer__
                                                     


File: python.info,  Node: slot typedefs,  Prev: sub-slots,  Up: Quick Reference

7.13.4.4 slot typedefs
......................

typedef                           Parameter Types                   Return Type
                                                                    
-----------------------------------------------------------------------------------------------
                                                                    
*note allocfunc: 5177.                 *note PyTypeObject: c9e. *   *note PyObject: 5df. *
                                       *note Py_ssize_t: c57.       
                                  
                                                                    
*note destructor: 517b.           *note PyObject: 5df. *            void
                                                                    
                                                                    
*note freefunc: 5422.             void *                            void
                                                                    
                                                                    
*note traverseproc: 5192.              *note PyObject: 5df. *       int
                                       *note visitproc: 5194.       
                                       void *
                                  
                                                                    
*note newfunc: 5186.                   *note PyTypeObject: c9e. *   *note PyObject: 5df. *
                                       *note PyObject: 5df. *       
                                       *note PyObject: 5df. *
                                  
                                                                    
*note initproc: 5182.                  *note PyObject: 5df. *       int
                                       *note PyObject: 5df. *       
                                       *note PyObject: 5df. *
                                  
                                                                    
*note reprfunc: 518a.             *note PyObject: 5df. *            *note PyObject: 5df. *
                                                                    
                                                                    
*note getattrfunc: 517c.               *note PyObject: 5df. *       *note PyObject: 5df. *
                                       const char *                 
                                  
                                                                    
*note setattrfunc: 518c.               *note PyObject: 5df. *       int
                                       const char *                 
                                       *note PyObject: 5df. *
                                  
                                                                    
*note getattrofunc: 517d.              *note PyObject: 5df. *       *note PyObject: 5df. *
                                       *note PyObject: 5df. *       
                                  
                                                                    
*note setattrofunc: 518d.              *note PyObject: 5df. *       int
                                       *note PyObject: 5df. *       
                                       *note PyObject: 5df. *
                                  
                                                                    
*note descrgetfunc: 5179.              *note PyObject: 5df. *       *note PyObject: 5df. *
                                       *note PyObject: 5df. *       
                                       *note PyObject: 5df. *
                                  
                                                                    
*note descrsetfunc: 517a.              *note PyObject: 5df. *       int
                                       *note PyObject: 5df. *       
                                       *note PyObject: 5df. *
                                  
                                                                    
*note hashfunc: 5181.             *note PyObject: 5df. *            Py_hash_t
                                                                    
                                                                    
*note richcmpfunc: 518b.               *note PyObject: 5df. *       *note PyObject: 5df. *
                                       *note PyObject: 5df. *       
                                       int
                                  
                                                                    
*note getiterfunc: 517f.          *note PyObject: 5df. *            *note PyObject: 5df. *
                                                                    
                                                                    
*note iternextfunc: 5184.         *note PyObject: 5df. *            *note PyObject: 5df. *
                                                                    
                                                                    
*note lenfunc: 5185.              *note PyObject: 5df. *            *note Py_ssize_t: c57.
                                                                    
                                                                    
*note getbufferproc: 517e.             *note PyObject: 5df. *       int
                                       *note Py_buffer: 95d. *      
                                       int
                                  
                                                                    
*note releasebufferproc: 5189.         *note PyObject: 5df. *       void
                                       *note Py_buffer: 95d. *      
                                  
                                                                    
*note inquiry: 5183.              *note PyObject: 5df. *            int
                                                                    
                                                                    
*note unaryfunc: 5193.                 *note PyObject: 5df. *       *note PyObject: 5df. *
                                                                    
                                                                    
*note binaryfunc: 5178.                *note PyObject: 5df. *       *note PyObject: 5df. *
                                       *note PyObject: 5df. *       
                                  
                                                                    
*note ternaryfunc: 5191.               *note PyObject: 5df. *       *note PyObject: 5df. *
                                       *note PyObject: 5df. *       
                                       *note PyObject: 5df. *
                                  
                                                                    
*note ssizeargfunc: 518f.              *note PyObject: 5df. *       *note PyObject: 5df. *
                                       *note Py_ssize_t: c57.       
                                  
                                                                    
*note ssizeobjargproc: 5190.           *note PyObject: 5df. *       int
                                       *note Py_ssize_t: c57.       
                                       *note PyObject: 5df. *
                                  
                                                                    
*note objobjproc: 5188.                *note PyObject: 5df. *       int
                                       *note PyObject: 5df. *       
                                  
                                                                    
*note objobjargproc: 5187.             *note PyObject: 5df. *       int
                                       *note PyObject: 5df. *       
                                       *note PyObject: 5df. *
                                  

See *note Slot Type typedefs: 5626. below for more detail.


File: python.info,  Node: PyTypeObject Definition,  Next: PyObject Slots,  Prev: Quick Reference,  Up: Type Object Structures

7.13.4.5 PyTypeObject Definition
................................

The structure definition for *note PyTypeObject: c9e. can be found in
‘Include/cpython/object.h’.  For convenience of reference, this repeats
the definition found there:

     typedef struct _typeobject {
         PyObject_VAR_HEAD
         const char *tp_name; /* For printing, in format "<module>.<name>" */
         Py_ssize_t tp_basicsize, tp_itemsize; /* For allocation */

         /* Methods to implement standard operations */

         destructor tp_dealloc;
         Py_ssize_t tp_vectorcall_offset;
         getattrfunc tp_getattr;
         setattrfunc tp_setattr;
         PyAsyncMethods *tp_as_async; /* formerly known as tp_compare (Python 2)
                                         or tp_reserved (Python 3) */
         reprfunc tp_repr;

         /* Method suites for standard classes */

         PyNumberMethods *tp_as_number;
         PySequenceMethods *tp_as_sequence;
         PyMappingMethods *tp_as_mapping;

         /* More standard operations (here for binary compatibility) */

         hashfunc tp_hash;
         ternaryfunc tp_call;
         reprfunc tp_str;
         getattrofunc tp_getattro;
         setattrofunc tp_setattro;

         /* Functions to access object as input/output buffer */
         PyBufferProcs *tp_as_buffer;

         /* Flags to define presence of optional/expanded features */
         unsigned long tp_flags;

         const char *tp_doc; /* Documentation string */

         /* Assigned meaning in release 2.0 */
         /* call function for all accessible objects */
         traverseproc tp_traverse;

         /* delete references to contained objects */
         inquiry tp_clear;

         /* Assigned meaning in release 2.1 */
         /* rich comparisons */
         richcmpfunc tp_richcompare;

         /* weak reference enabler */
         Py_ssize_t tp_weaklistoffset;

         /* Iterators */
         getiterfunc tp_iter;
         iternextfunc tp_iternext;

         /* Attribute descriptor and subclassing stuff */
         PyMethodDef *tp_methods;
         PyMemberDef *tp_members;
         PyGetSetDef *tp_getset;
         // Strong reference on a heap type, borrowed reference on a static type
         PyTypeObject *tp_base;
         PyObject *tp_dict;
         descrgetfunc tp_descr_get;
         descrsetfunc tp_descr_set;
         Py_ssize_t tp_dictoffset;
         initproc tp_init;
         allocfunc tp_alloc;
         newfunc tp_new;
         freefunc tp_free; /* Low-level free-memory routine */
         inquiry tp_is_gc; /* For PyObject_IS_GC */
         PyObject *tp_bases;
         PyObject *tp_mro; /* method resolution order */
         PyObject *tp_cache; /* no longer used */
         void *tp_subclasses;  /* for static builtin types this is an index */
         PyObject *tp_weaklist; /* not used for static builtin types */
         destructor tp_del;

         /* Type attribute cache version tag. Added in version 2.6.
          * If zero, the cache is invalid and must be initialized.
          */
         unsigned int tp_version_tag;

         destructor tp_finalize;
         vectorcallfunc tp_vectorcall;

         /* bitset of which type-watchers care about this type */
         unsigned char tp_watched;

         /* Number of tp_version_tag values used.
          * Set to _Py_ATTR_CACHE_UNUSED if the attribute cache is
          * disabled for this type (e.g. due to custom MRO entries).
          * Otherwise, limited to MAX_VERSIONS_PER_CLASS (defined elsewhere).
          */
         uint16_t tp_versions_used;
     } PyTypeObject;


File: python.info,  Node: PyObject Slots,  Next: PyVarObject Slots,  Prev: PyTypeObject Definition,  Up: Type Object Structures

7.13.4.6 PyObject Slots
.......................

The type object structure extends the *note PyVarObject: 46be.
structure.  The *note ob_size: 50f4. field is used for dynamic types
(created by ‘type_new()’, usually called from a class statement).  Note
that *note PyType_Type: 770. (the metatype) initializes *note
tp_itemsize: 23a1, which means that its instances (i.e.  type objects)
'must' have the *note ob_size: 50f4. field.

*note PyObject.ob_refcnt: aa1.

     The type object’s reference count is initialized to ‘1’ by the
     ‘PyObject_HEAD_INIT’ macro.  Note that for *note statically
     allocated type objects: 984, the type’s instances (objects whose
     *note ob_type: 4eb6. points back to the type) do 'not' count as
     references.  But for *note dynamically allocated type objects: b60,
     the instances 'do' count as references.

     'Inheritance:'

     This field is not inherited by subtypes.

*note PyObject.ob_type: 4eb6.

     This is the type’s type, in other words its metatype.  It is
     initialized by the argument to the ‘PyObject_HEAD_INIT’ macro, and
     its value should normally be ‘&PyType_Type’.  However, for
     dynamically loadable extension modules that must be usable on
     Windows (at least), the compiler complains that this is not a valid
     initializer.  Therefore, the convention is to pass ‘NULL’ to the
     ‘PyObject_HEAD_INIT’ macro and to initialize this field explicitly
     at the start of the module’s initialization function, before doing
     anything else.  This is typically done like this:

          Foo_Type.ob_type = &PyType_Type;

     This should be done before any instances of the type are created.
     *note PyType_Ready(): 981. checks if *note ob_type: 4eb6. is
     ‘NULL’, and if so, initializes it to the *note ob_type: 4eb6. field
     of the base class.  *note PyType_Ready(): 981. will not change this
     field if it is non-zero.

     'Inheritance:'

     This field is inherited by subtypes.


File: python.info,  Node: PyVarObject Slots,  Next: PyTypeObject Slots,  Prev: PyObject Slots,  Up: Type Object Structures

7.13.4.7 PyVarObject Slots
..........................

*note PyVarObject.ob_size: 50f4.

     For *note statically allocated type objects: 984, this should be
     initialized to zero.  For *note dynamically allocated type objects:
     b60, this field has a special internal meaning.

     This field should be accessed using the *note Py_SIZE(): 986.
     macro.

     'Inheritance:'

     This field is not inherited by subtypes.


File: python.info,  Node: PyTypeObject Slots,  Next: Static Types,  Prev: PyVarObject Slots,  Up: Type Object Structures

7.13.4.8 PyTypeObject Slots
...........................

Each slot has a section describing inheritance.  If *note
PyType_Ready(): 981. may set a value when the field is set to ‘NULL’
then there will also be a «Default» section.  (Note that many fields set
on *note PyBaseObject_Type: 4f4d. and *note PyType_Type: 770.
effectively act as defaults.)

 -- C Membro: const char **note PyTypeObject: c9e.tp_name

     Pointer to a NUL-terminated string containing the name of the type.
     For types that are accessible as module globals, the string should
     be the full module name, followed by a dot, followed by the type
     name; for built-in types, it should be just the type name.  If the
     module is a submodule of a package, the full package name is part
     of the full module name.  For example, a type named ‘T’ defined in
     module ‘M’ in subpackage ‘Q’ in package ‘P’ should have the *note
     tp_name: 1c98. initializer ‘"P.Q.M.T"’.

     For *note dynamically allocated type objects: b60, this should just
     be the type name, and the module name explicitly stored in the type
     dict as the value for key ‘'__module__'’.

     For *note statically allocated type objects: 984, the 'tp_name'
     field should contain a dot.  Everything before the last dot is made
     accessible as the *note __module__: 617. attribute, and everything
     after the last dot is made accessible as the *note __name__: 16b2.
     attribute.

     If no dot is present, the entire *note tp_name: 1c98. field is made
     accessible as the *note __name__: 16b2. attribute, and the *note
     __module__: 617. attribute is undefined (unless explicitly set in
     the dictionary, as explained above).  This means your type will be
     impossible to pickle.  Additionally, it will not be listed in
     module documentations created with pydoc.

     This field must not be ‘NULL’.  It is the only required field in
     *note PyTypeObject(): c9e. (other than potentially *note
     tp_itemsize: 23a1.).

     'Inheritance:'

     This field is not inherited by subtypes.

 -- C Membro: *note Py_ssize_t: c57. *note PyTypeObject:
          c9e.tp_basicsize
 -- C Membro: *note Py_ssize_t: c57. *note PyTypeObject: c9e.tp_itemsize

     These fields allow calculating the size in bytes of instances of
     the type.

     There are two kinds of types: types with fixed-length instances
     have a zero ‘tp_itemsize’ field, types with variable-length
     instances have a non-zero ‘tp_itemsize’ field.  For a type with
     fixed-length instances, all instances have the same size, given in
     ‘tp_basicsize’.  (Exceptions to this rule can be made using *note
     PyUnstable_Object_GC_NewWithExtraData(): 1a90.)

     For a type with variable-length instances, the instances must have
     an *note ob_size: 50f4. field, and the instance size is
     ‘tp_basicsize’ plus N times ‘tp_itemsize’, where N is the «length»
     of the object.

     Functions like *note PyObject_NewVar(): b7f. will take the value of
     N as an argument, and store in the instance’s *note ob_size: 50f4.
     field.  Note that the *note ob_size: 50f4. field may later be used
     for other purposes.  For example, *note int: 19b. instances use the
     bits of *note ob_size: 50f4. in an implementation-defined way; the
     underlying storage and its size should be accessed using *note
     PyLong_Export(): 3a8.

          Nota: The *note ob_size: 50f4. field should be accessed using
          the *note Py_SIZE(): 986. and *note Py_SET_SIZE(): 987.
          macros.

     Also, the presence of an *note ob_size: 50f4. field in the instance
     layout doesn’t mean that the instance structure is variable-length.
     For example, the *note list: 24d. type has fixed-length instances,
     yet those instances have a *note ob_size: 50f4. field.  (As with
     *note int: 19b, avoid reading lists” ‘ob_size’ directly.  Call
     *note PyList_Size(): 1621. instead.)

     The ‘tp_basicsize’ includes size needed for data of the type’s
     *note tp_base: 235c, plus any extra data needed by each instance.

     The correct way to set ‘tp_basicsize’ is to use the ‘sizeof’
     operator on the struct used to declare the instance layout.  This
     struct must include the struct used to declare the base type.  In
     other words, ‘tp_basicsize’ must be greater than or equal to the
     base’s ‘tp_basicsize’.

     Since every type is a subtype of *note object: c80, this struct
     must include *note PyObject: 5df. or *note PyVarObject: 46be.
     (depending on whether *note ob_size: 50f4. should be included).
     These are usually defined by the macro *note PyObject_HEAD: 14e5.
     or *note PyObject_VAR_HEAD: 55c6, respectively.

     The basic size does not include the GC header size, as that header
     is not part of *note PyObject_HEAD: 14e5.

     For cases where struct used to declare the base type is unknown,
     see *note PyType_Spec.basicsize: 76b. and *note
     PyType_FromMetaclass(): 773.

     Notes about alignment:

        - ‘tp_basicsize’ must be a multiple of ‘_Alignof(PyObject)’.
          When using ‘sizeof’ on a ‘struct’ that includes *note
          PyObject_HEAD: 14e5, as recommended, the compiler ensures
          this.  When not using a C ‘struct’, or when using compiler
          extensions like ‘__attribute__((packed))’, it is up to you.

        - If the variable items require a particular alignment,
          ‘tp_basicsize’ and ‘tp_itemsize’ must each be a multiple of
          that alignment.  For example, if a type’s variable part stores
          a ‘double’, it is your responsibility that both fields are a
          multiple of ‘_Alignof(double)’.

     'Inheritance:'

     These fields are inherited separately by subtypes.  (That is, if
     the field is set to zero, *note PyType_Ready(): 981. will copy the
     value from the base type, indicating that the instances do not need
     additional storage.)

     If the base type has a non-zero *note tp_itemsize: 23a1, it is
     generally not safe to set *note tp_itemsize: 23a1. to a different
     non-zero value in a subtype (though this depends on the
     implementation of the base type).

 -- C Membro: *note destructor: 517b. *note PyTypeObject: c9e.tp_dealloc

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_dealloc’ is part of
     the *note ABI Stabile: 776.'

     A pointer to the instance destructor function.  The function
     signature is:

          void tp_dealloc(PyObject *self);

     The destructor function should remove all references which the
     instance owns (e.g., call *note Py_CLEAR(): 799.), free all memory
     buffers owned by the instance, and call the type’s *note tp_free:
     4eb8. function to free the object itself.

     If you may call functions that may set the error indicator, you
     must use *note PyErr_GetRaisedException(): 429. and *note
     PyErr_SetRaisedException(): 42c. to ensure you don’t clobber a
     preexisting error indicator (the deallocation could have occurred
     while processing a different error):

          static void
          foo_dealloc(foo_object *self)
          {
              PyObject *et, *ev, *etb;
              PyObject *exc = PyErr_GetRaisedException();
              ...
              PyErr_SetRaisedException(exc);
          }

     The dealloc handler itself must not raise an exception; if it hits
     an error case it should call *note PyErr_FormatUnraisable(): 5f1.
     to log (and clear) an unraisable exception.

     No guarantees are made about when an object is destroyed, except:

        * Python will destroy an object immediately or some time after
          the final reference to the object is deleted, unless its
          finalizer (*note tp_finalize: c9f.) subsequently resurrects
          the object.

        * An object will not be destroyed while it is being
          automatically finalized (*note tp_finalize: c9f.) or
          automatically cleared (*note tp_clear: 4ecb.).

     CPython currently destroys an object immediately from *note
     Py_DECREF(): 791. when the new reference count is zero, but this
     may change in a future version.

     It is recommended to call *note
     PyObject_CallFinalizerFromDealloc(): 55bc. at the beginning of
     ‘tp_dealloc’ to guarantee that the object is always finalized
     before destruction.

     If the type supports garbage collection (the *note
     Py_TPFLAGS_HAVE_GC: 982. flag is set), the destructor should call
     *note PyObject_GC_UnTrack(): 170c. before clearing any member
     fields.

     It is permissible to call *note tp_clear: 4ecb. from ‘tp_dealloc’
     to reduce code duplication and to guarantee that the object is
     always cleared before destruction.  Beware that ‘tp_clear’ might
     have already been called.

     If the type is heap allocated (*note Py_TPFLAGS_HEAPTYPE: aae.),
     the deallocator should release the owned reference to its type
     object (via *note Py_DECREF(): 791.) after calling the type
     deallocator.  See the example code below.:

          static void
          foo_dealloc(PyObject *op)
          {
             foo_object *self = (foo_object *) op;
             PyObject_GC_UnTrack(self);
             Py_CLEAR(self->ref);
             Py_TYPE(self)->tp_free(self);
          }

     ‘tp_dealloc’ must leave the exception status unchanged.  If it
     needs to call something that might raise an exception, the
     exception state must be backed up first and restored later (after
     logging any exceptions with *note PyErr_WriteUnraisable(): 5f2.).

     Example:

          static void
          foo_dealloc(PyObject *self)
          {
              PyObject *exc = PyErr_GetRaisedException();

              if (PyObject_CallFinalizerFromDealloc(self) < 0) {
                  // self was resurrected.
                  goto done;
              }

              PyTypeObject *tp = Py_TYPE(self);

              if (tp->tp_flags & Py_TPFLAGS_HAVE_GC) {
                  PyObject_GC_UnTrack(self);
              }

              // Optional, but convenient to avoid code duplication.
              if (tp->tp_clear && tp->tp_clear(self) < 0) {
                  PyErr_WriteUnraisable(self);
              }

              // Any additional destruction goes here.

              tp->tp_free(self);
              self = NULL;  // In case PyErr_WriteUnraisable() is called below.

              if (tp->tp_flags & Py_TPFLAGS_HEAPTYPE) {
                  Py_CLEAR(tp);
              }

          done:
              // Optional, if something was called that might have raised an
              // exception.
              if (PyErr_Occurred()) {
                  PyErr_WriteUnraisable(self);
              }
              PyErr_SetRaisedException(exc);
          }

     ‘tp_dealloc’ may be called from any Python thread, not just the
     thread which created the object (if the object becomes part of a
     refcount cycle, that cycle might be collected by a garbage
     collection on any thread).  This is not a problem for Python API
     calls, since the thread on which ‘tp_dealloc’ is called with an
     *note attached thread state: 4eba.  However, if the object being
     destroyed in turn destroys objects from some other C library, care
     should be taken to ensure that destroying those objects on the
     thread which called ‘tp_dealloc’ will not violate any assumptions
     of the library.

     'Inheritance:'

     This field is inherited by subtypes.

     Vedi anche
     ..........

     *note Object Life Cycle: 55b8. for details about how this slot
     relates to other slots.

 -- C Membro: *note Py_ssize_t: c57. *note PyTypeObject:
          c9e.tp_vectorcall_offset

     An optional offset to a per-instance function that implements
     calling the object using the *note vectorcall protocol: 775, a more
     efficient alternative of the simpler *note tp_call: 77c.

     This field is only used if the flag *note
     Py_TPFLAGS_HAVE_VECTORCALL: 777. is set.  If so, this must be a
     positive integer containing the offset in the instance of a *note
     vectorcallfunc: 77a. pointer.

     The 'vectorcallfunc' pointer may be ‘NULL’, in which case the
     instance behaves as if *note Py_TPFLAGS_HAVE_VECTORCALL: 777. was
     not set: calling the instance falls back to *note tp_call: 77c.

     Any class that sets ‘Py_TPFLAGS_HAVE_VECTORCALL’ must also set
     *note tp_call: 77c. and make sure its behaviour is consistent with
     the 'vectorcallfunc' function.  This can be done by setting
     'tp_call' to *note PyVectorcall_Call(): 779.

     Cambiato nella versione 3.8: Before version 3.8, this slot was
     named ‘tp_print’.  In Python 2.x, it was used for printing to a
     file.  In Python 3.0 to 3.7, it was unused.

     Cambiato nella versione 3.12: Before version 3.12, it was not
     recommended for *note mutable heap types: b60. to implement the
     vectorcall protocol.  When a user sets *note __call__: 77b. in
     Python code, only 'tp_call' is updated, likely making it
     inconsistent with the vectorcall function.  Since 3.12, setting
     ‘__call__’ will disable vectorcall optimization by clearing the
     *note Py_TPFLAGS_HAVE_VECTORCALL: 777. flag.

     'Inheritance:'

     This field is always inherited.  However, the *note
     Py_TPFLAGS_HAVE_VECTORCALL: 777. flag is not always inherited.  If
     it’s not set, then the subclass won’t use *note vectorcall: 775,
     except when *note PyVectorcall_Call(): 779. is explicitly called.

 -- C Membro: *note getattrfunc: 517c. *note PyTypeObject:
          c9e.tp_getattr

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_getattr’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to the get-attribute-string function.

     This field is deprecated.  When it is defined, it should point to a
     function that acts the same as the *note tp_getattro: 1a4c.
     function, but taking a C string instead of a Python string object
     to give the attribute name.

     'Inheritance:'

     Group: *note tp_getattr: 4ed6, *note tp_getattro: 1a4c.

     This field is inherited by subtypes together with *note
     tp_getattro: 1a4c.: a subtype inherits both *note tp_getattr: 4ed6.
     and *note tp_getattro: 1a4c. from its base type when the subtype’s
     *note tp_getattr: 4ed6. and *note tp_getattro: 1a4c. are both
     ‘NULL’.

 -- C Membro: *note setattrfunc: 518c. *note PyTypeObject:
          c9e.tp_setattr

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_setattr’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to the function for setting and deleting
     attributes.

     This field is deprecated.  When it is defined, it should point to a
     function that acts the same as the *note tp_setattro: 4ed1.
     function, but taking a C string instead of a Python string object
     to give the attribute name.

     'Inheritance:'

     Group: *note tp_setattr: 4ed7, *note tp_setattro: 4ed1.

     This field is inherited by subtypes together with *note
     tp_setattro: 4ed1.: a subtype inherits both *note tp_setattr: 4ed7.
     and *note tp_setattro: 4ed1. from its base type when the subtype’s
     *note tp_setattr: 4ed7. and *note tp_setattro: 4ed1. are both
     ‘NULL’.

 -- C Membro: *note PyAsyncMethods: 52c3. **note PyTypeObject:
          c9e.tp_as_async

     Pointer to an additional structure that contains fields relevant
     only to objects which implement *note awaitable: 4ca. and *note
     asynchronous iterator: 4c8. protocols at the C-level.  See *note
     Async Object Structures: 562b. for details.

     Added in version 3.5: Formerly known as ‘tp_compare’ and
     ‘tp_reserved’.

     'Inheritance:'

     The *note tp_as_async: 10d1. field is not inherited, but the
     contained fields are inherited individually.

 -- C Membro: *note reprfunc: 518a. *note PyTypeObject: c9e.tp_repr

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_repr’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to a function that implements the built-in
     function *note repr(): 1c1.

     The signature is the same as for *note PyObject_Repr(): 1231.:

          PyObject *tp_repr(PyObject *self);

     The function must return a string or a Unicode object.  Ideally,
     this function should return a string that, when passed to *note
     eval(): 4a4, given a suitable environment, returns an object with
     the same value.  If this is not feasible, it should return a string
     starting with ‘'<'’ and ending with ‘'>'’ from which both the type
     and the value of the object can be deduced.

     'Inheritance:'

     This field is inherited by subtypes.

     'Default:'

     When this field is not set, a string of the form ‘<%s object at
     %p>’ is returned, where ‘%s’ is replaced by the type name, and ‘%p’
     by the object’s memory address.

 -- C Membro: *note PyNumberMethods: 1625. **note PyTypeObject:
          c9e.tp_as_number

     Pointer to an additional structure that contains fields relevant
     only to objects which implement the number protocol.  These fields
     are documented in *note Number Object Structures: 562c.

     'Inheritance:'

     The *note tp_as_number: b84. field is not inherited, but the
     contained fields are inherited individually.

 -- C Membro: *note PySequenceMethods: 4edd. **note PyTypeObject:
          c9e.tp_as_sequence

     Pointer to an additional structure that contains fields relevant
     only to objects which implement the sequence protocol.  These
     fields are documented in *note Sequence Object Structures: 562d.

     'Inheritance:'

     The *note tp_as_sequence: 55ed. field is not inherited, but the
     contained fields are inherited individually.

 -- C Membro: *note PyMappingMethods: 4ede. **note PyTypeObject:
          c9e.tp_as_mapping

     Pointer to an additional structure that contains fields relevant
     only to objects which implement the mapping protocol.  These fields
     are documented in *note Mapping Object Structures: 562e.

     'Inheritance:'

     The *note tp_as_mapping: 55ee. field is not inherited, but the
     contained fields are inherited individually.

 -- C Membro: *note hashfunc: 5181. *note PyTypeObject: c9e.tp_hash

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_hash’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to a function that implements the built-in
     function *note hash(): 802.

     The signature is the same as for *note PyObject_Hash(): 436.:

          Py_hash_t tp_hash(PyObject *);

     The value ‘-1’ should not be returned as a normal return value;
     when an error occurs during the computation of the hash value, the
     function should set an exception and return ‘-1’.

     When this field is not set ('and' *note tp_richcompare: 4ed9. is
     not set), an attempt to take the hash of the object raises *note
     TypeError: 198.  This is the same as setting it to *note
     PyObject_HashNotImplemented(): 15ce.

     This field can be set explicitly to *note
     PyObject_HashNotImplemented(): 15ce. to block inheritance of the
     hash method from a parent type.  This is interpreted as the
     equivalent of ‘__hash__ = None’ at the Python level, causing
     ‘isinstance(o, collections.Hashable)’ to correctly return ‘False’.
     Note that the converse is also true - setting ‘__hash__ = None’ on
     a class at the Python level will result in the ‘tp_hash’ slot being
     set to *note PyObject_HashNotImplemented(): 15ce.

     'Inheritance:'

     Group: *note tp_hash: 4edf, *note tp_richcompare: 4ed9.

     This field is inherited by subtypes together with *note
     tp_richcompare: 4ed9.: a subtype inherits both of *note
     tp_richcompare: 4ed9. and *note tp_hash: 4edf, when the subtype’s
     *note tp_richcompare: 4ed9. and *note tp_hash: 4edf. are both
     ‘NULL’.

     'Default:'

     *note PyBaseObject_Type: 4f4d. uses *note PyObject_GenericHash():
     60c.

 -- C Membro: *note ternaryfunc: 5191. *note PyTypeObject: c9e.tp_call

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_call’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to a function that implements calling the
     object.  This should be ‘NULL’ if the object is not callable.  The
     signature is the same as for *note PyObject_Call(): 63d.:

          PyObject *tp_call(PyObject *self, PyObject *args, PyObject *kwargs);

     'Inheritance:'

     This field is inherited by subtypes.

 -- C Membro: *note reprfunc: 518a. *note PyTypeObject: c9e.tp_str

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_str’ is part of the
     *note ABI Stabile: 776.'

     An optional pointer to a function that implements the built-in
     operation *note str(): 169.  (Note that *note str: 169. is a type
     now, and *note str(): 169. calls the constructor for that type.
     This constructor calls *note PyObject_Str(): 1232. to do the actual
     work, and *note PyObject_Str(): 1232. will call this handler.)

     The signature is the same as for *note PyObject_Str(): 1232.:

          PyObject *tp_str(PyObject *self);

     The function must return a string or a Unicode object.  It should
     be a «friendly» string representation of the object, as this is the
     representation that will be used, among other things, by the *note
     print(): 1177. function.

     'Inheritance:'

     This field is inherited by subtypes.

     'Default:'

     When this field is not set, *note PyObject_Repr(): 1231. is called
     to return a string representation.

 -- C Membro: *note getattrofunc: 517d. *note PyTypeObject:
          c9e.tp_getattro

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_getattro’ is part
     of the *note ABI Stabile: 776.'

     An optional pointer to the get-attribute function.

     The signature is the same as for *note PyObject_GetAttr(): 5ee.:

          PyObject *tp_getattro(PyObject *self, PyObject *attr);

     It is usually convenient to set this field to *note
     PyObject_GenericGetAttr(): 5066, which implements the normal way of
     looking for object attributes.

     'Inheritance:'

     Group: *note tp_getattr: 4ed6, *note tp_getattro: 1a4c.

     This field is inherited by subtypes together with *note tp_getattr:
     4ed6.: a subtype inherits both *note tp_getattr: 4ed6. and *note
     tp_getattro: 1a4c. from its base type when the subtype’s *note
     tp_getattr: 4ed6. and *note tp_getattro: 1a4c. are both ‘NULL’.

     'Default:'

     *note PyBaseObject_Type: 4f4d. uses *note
     PyObject_GenericGetAttr(): 5066.

 -- C Membro: *note setattrofunc: 518d. *note PyTypeObject:
          c9e.tp_setattro

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_setattro’ is part
     of the *note ABI Stabile: 776.'

     An optional pointer to the function for setting and deleting
     attributes.

     The signature is the same as for *note PyObject_SetAttr(): 506f.:

          int tp_setattro(PyObject *self, PyObject *attr, PyObject *value);

     In addition, setting 'value' to ‘NULL’ to delete an attribute must
     be supported.  It is usually convenient to set this field to *note
     PyObject_GenericSetAttr(): 5067, which implements the normal way of
     setting object attributes.

     'Inheritance:'

     Group: *note tp_setattr: 4ed7, *note tp_setattro: 4ed1.

     This field is inherited by subtypes together with *note tp_setattr:
     4ed7.: a subtype inherits both *note tp_setattr: 4ed7. and *note
     tp_setattro: 4ed1. from its base type when the subtype’s *note
     tp_setattr: 4ed7. and *note tp_setattro: 4ed1. are both ‘NULL’.

     'Default:'

     *note PyBaseObject_Type: 4f4d. uses *note
     PyObject_GenericSetAttr(): 5067.

 -- C Membro: *note PyBufferProcs: 52ca. **note PyTypeObject:
          c9e.tp_as_buffer

     Pointer to an additional structure that contains fields relevant
     only to objects which implement the buffer interface.  These fields
     are documented in *note Buffer Object Structures: 5290.

     'Inheritance:'

     The *note tp_as_buffer: b82. field is not inherited, but the
     contained fields are inherited individually.

 -- C Membro: unsigned long *note PyTypeObject: c9e.tp_flags

     This field is a bit mask of various flags.  Some flags indicate
     variant semantics for certain situations; others are used to
     indicate that certain fields in the type object (or in the
     extension structures referenced via *note tp_as_number: b84, *note
     tp_as_sequence: 55ed, *note tp_as_mapping: 55ee, and *note
     tp_as_buffer: b82.) that were historically not always present are
     valid; if such a flag bit is clear, the type fields it guards must
     not be accessed and must be considered to have a zero or ‘NULL’
     value instead.

     'Inheritance:'

     Inheritance of this field is complicated.  Most flag bits are
     inherited individually, i.e.  if the base type has a flag bit set,
     the subtype inherits this flag bit.  The flag bits that pertain to
     extension structures are strictly inherited if the extension
     structure is inherited, i.e.  the base type’s value of the flag bit
     is copied into the subtype together with a pointer to the extension
     structure.  The *note Py_TPFLAGS_HAVE_GC: 982. flag bit is
     inherited together with the *note tp_traverse: 983. and *note
     tp_clear: 4ecb. fields, i.e.  if the *note Py_TPFLAGS_HAVE_GC: 982.
     flag bit is clear in the subtype and the *note tp_traverse: 983.
     and *note tp_clear: 4ecb. fields in the subtype exist and have
     ‘NULL’ values.

     'Default:'

     *note PyBaseObject_Type: 4f4d. uses ‘Py_TPFLAGS_DEFAULT |
     Py_TPFLAGS_BASETYPE’.

     'Bit Masks:'

     The following bit masks are currently defined; these can be ORed
     together using the ‘|’ operator to form the value of the *note
     tp_flags: 1c59. field.  The macro *note PyType_HasFeature(): 1d24.
     takes a type and a flags value, 'tp' and 'f', and checks whether
     ‘tp->tp_flags & f’ is non-zero.

      -- C Macro: Py_TPFLAGS_HEAPTYPE

          This bit is set when the type object itself is allocated on
          the heap, for example, types created dynamically using *note
          PyType_FromSpec(): 79e.  In this case, the *note ob_type:
          4eb6. field of its instances is considered a reference to the
          type, and the type object is INCREF’ed when a new instance is
          created, and DECREF’ed when an instance is destroyed (this
          does not apply to instances of subtypes; only the type
          referenced by the instance’s ob_type gets INCREF’ed or
          DECREF’ed).  Heap types should also *note support garbage
          collection: 562f. as they can form a reference cycle with
          their own module object.

          'Inheritance:'

          ???

      -- C Macro: Py_TPFLAGS_BASETYPE
          ' Parte del *note ABI Stabile: 776.'  This bit is set when the
          type can be used as the base type of another type.  If this
          bit is clear, the type cannot be subtyped (similar to a
          «final» class in Java).

          'Inheritance:'

          ???

      -- C Macro: Py_TPFLAGS_READY

          This bit is set when the type object has been fully
          initialized by *note PyType_Ready(): 981.

          'Inheritance:'

          ???

      -- C Macro: Py_TPFLAGS_READYING

          This bit is set while *note PyType_Ready(): 981. is in the
          process of initializing the type object.

          'Inheritance:'

          ???

      -- C Macro: Py_TPFLAGS_HAVE_GC
          ' Parte del *note ABI Stabile: 776.'  This bit is set when the
          object supports garbage collection.  If this bit is set,
          memory for new instances (see *note tp_alloc: 4eb9.) must be
          allocated using *note PyObject_GC_New: c9b. or *note
          PyType_GenericAlloc(): c63. and deallocated (see *note
          tp_free: 4eb8.) using *note PyObject_GC_Del(): 170a.  More
          information in section *note Supporting Cyclic Garbage
          Collection: 562f.

          'Inheritance:'

          Group: *note Py_TPFLAGS_HAVE_GC: 982, *note tp_traverse: 983,
          *note tp_clear: 4ecb.

          The *note Py_TPFLAGS_HAVE_GC: 982. flag bit is inherited
          together with the *note tp_traverse: 983. and *note tp_clear:
          4ecb. fields, i.e.  if the *note Py_TPFLAGS_HAVE_GC: 982. flag
          bit is clear in the subtype and the *note tp_traverse: 983.
          and *note tp_clear: 4ecb. fields in the subtype exist and have
          ‘NULL’ values.

      -- C Macro: Py_TPFLAGS_DEFAULT
          ' Parte del *note ABI Stabile: 776.'  This is a bitmask of all
          the bits that pertain to the existence of certain fields in
          the type object and its extension structures.  Currently, it
          includes the following bits:
          ‘Py_TPFLAGS_HAVE_STACKLESS_EXTENSION’.

          'Inheritance:'

          ???

      -- C Macro: Py_TPFLAGS_METHOD_DESCRIPTOR
          ' Parte del *note ABI Stabile: 776. dalla versione 3.8.'  This
          bit indicates that objects behave like unbound methods.

          If this flag is set for ‘type(meth)’, then:

             - ‘meth.__get__(obj, cls)(*args, **kwds)’ (with ‘obj’ not
               None) must be equivalent to ‘meth(obj, *args, **kwds)’.

             - ‘meth.__get__(None, cls)(*args, **kwds)’ must be
               equivalent to ‘meth(*args, **kwds)’.

          This flag enables an optimization for typical method calls
          like ‘obj.meth()’: it avoids creating a temporary «bound
          method» object for ‘obj.meth’.

          Added in version 3.8.

          'Inheritance:'

          This flag is never inherited by types without the *note
          Py_TPFLAGS_IMMUTABLETYPE: 3cf. flag set.  For extension types,
          it is inherited whenever *note tp_descr_get: 55ef. is
          inherited.

      -- C Macro: Py_TPFLAGS_MANAGED_DICT

          This bit indicates that instances of the class have a *note
          __dict__: 77e. attribute, and that the space for the
          dictionary is managed by the VM.

          If this flag is set, *note Py_TPFLAGS_HAVE_GC: 982. should
          also be set.

          The type traverse function must call *note
          PyObject_VisitManagedDict(): 60d. and its clear function must
          call *note PyObject_ClearManagedDict(): 60e.

          Added in version 3.12.

          'Inheritance:'

          This flag is inherited unless the *note tp_dictoffset: 52c5.
          field is set in a superclass.

      -- C Macro: Py_TPFLAGS_MANAGED_WEAKREF

          This bit indicates that instances of the class should be
          weakly referenceable.

          Added in version 3.12.

          'Inheritance:'

          This flag is inherited unless the *note tp_weaklistoffset:
          b81. field is set in a superclass.

      -- C Macro: Py_TPFLAGS_ITEMS_AT_END
          ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'
          Only usable with variable-size types, i.e.  ones with non-zero
          *note tp_itemsize: 23a1.

          Indicates that the variable-sized portion of an instance of
          this type is at the end of the instance’s memory area, at an
          offset of ‘Py_TYPE(obj)->tp_basicsize’ (which may be different
          in each subclass).

          When setting this flag, be sure that all superclasses either
          use this memory layout, or are not variable-sized.  Python
          does not check this.

          Added in version 3.12.

          'Inheritance:'

          This flag is inherited.

      -- C Macro: Py_TPFLAGS_LONG_SUBCLASS

      -- C Macro: Py_TPFLAGS_LIST_SUBCLASS

      -- C Macro: Py_TPFLAGS_TUPLE_SUBCLASS

      -- C Macro: Py_TPFLAGS_BYTES_SUBCLASS

      -- C Macro: Py_TPFLAGS_UNICODE_SUBCLASS

      -- C Macro: Py_TPFLAGS_DICT_SUBCLASS

      -- C Macro: Py_TPFLAGS_BASE_EXC_SUBCLASS

      -- C Macro: Py_TPFLAGS_TYPE_SUBCLASS

          Functions such as *note PyLong_Check(): 52d5. will call *note
          PyType_FastSubclass(): 52b7. with one of these flags to
          quickly determine if a type is a subclass of a built-in type;
          such specific checks are faster than a generic check, like
          *note PyObject_IsInstance(): 10a8.  Custom types that inherit
          from built-ins should have their *note tp_flags: 1c59. set
          appropriately, or the code that interacts with such types will
          behave differently depending on what kind of check is used.

      -- C Macro: Py_TPFLAGS_HAVE_FINALIZE

          This bit is set when the *note tp_finalize: c9f. slot is
          present in the type structure.

          Added in version 3.4.

          Deprecato dalla versione 3.8: This flag isn’t necessary
          anymore, as the interpreter assumes the *note tp_finalize:
          c9f. slot is always present in the type structure.

      -- C Macro: Py_TPFLAGS_HAVE_VECTORCALL
          ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'
          This bit is set when the class implements the *note vectorcall
          protocol: 775.  See *note tp_vectorcall_offset: 526e. for
          details.

          'Inheritance:'

          This bit is inherited if *note tp_call: 77c. is also
          inherited.

          Added in version 3.8: as ‘_Py_TPFLAGS_HAVE_VECTORCALL’

          Cambiato nella versione 3.9.

          Renamed to the current name, without the leading underscore.
          The old provisional name is *note soft deprecated: 23d.

          Cambiato nella versione 3.12: This flag is now removed from a
          class when the class’s *note __call__(): 77b. method is
          reassigned.

          This flag can now be inherited by mutable classes.

      -- C Macro: Py_TPFLAGS_IMMUTABLETYPE

          This bit is set for type objects that are immutable: type
          attributes cannot be set nor deleted.

          *note PyType_Ready(): 981. automatically applies this flag to
          *note static types: 984.

          'Inheritance:'

          This flag is not inherited.

          Added in version 3.10.

      -- C Macro: Py_TPFLAGS_DISALLOW_INSTANTIATION

          Disallow creating instances of the type: set *note tp_new:
          7a0. to NULL and don’t create the ‘__new__’ key in the type
          dictionary.

          The flag must be set before creating the type, not after.  For
          example, it must be set before *note PyType_Ready(): 981. is
          called on the type.

          The flag is set automatically on *note static types: 984. if
          *note tp_base: 235c. is NULL or ‘&PyBaseObject_Type’ and *note
          tp_new: 7a0. is NULL.

          'Inheritance:'

          This flag is not inherited.  However, subclasses will not be
          instantiable unless they provide a non-NULL *note tp_new: 7a0.
          (which is only possible via the C API).

               Nota: To disallow instantiating a class directly but
               allow instantiating its subclasses (e.g.  for an *note
               abstract base class: 13be.), do not use this flag.
               Instead, make *note tp_new: 7a0. only succeed for
               subclasses.

          Added in version 3.10.

      -- C Macro: Py_TPFLAGS_MAPPING

          This bit indicates that instances of the class may match
          mapping patterns when used as the subject of a *note match:
          a10. block.  It is automatically set when registering or
          subclassing *note collections.abc.Mapping: ac9, and unset when
          registering *note collections.abc.Sequence: 13cc.

               Nota: *note Py_TPFLAGS_MAPPING: 1c40. and *note
               Py_TPFLAGS_SEQUENCE: 1c41. are mutually exclusive; it is
               an error to enable both flags simultaneously.

          'Inheritance:'

          This flag is inherited by types that do not already set *note
          Py_TPFLAGS_SEQUENCE: 1c41.

          Vedi anche
          ..........

          PEP 634(1) – Structural Pattern Matching: Specification

          Added in version 3.10.

      -- C Macro: Py_TPFLAGS_SEQUENCE

          This bit indicates that instances of the class may match
          sequence patterns when used as the subject of a *note match:
          a10. block.  It is automatically set when registering or
          subclassing *note collections.abc.Sequence: 13cc, and unset
          when registering *note collections.abc.Mapping: ac9.

               Nota: *note Py_TPFLAGS_MAPPING: 1c40. and *note
               Py_TPFLAGS_SEQUENCE: 1c41. are mutually exclusive; it is
               an error to enable both flags simultaneously.

          'Inheritance:'

          This flag is inherited by types that do not already set *note
          Py_TPFLAGS_MAPPING: 1c40.

          Vedi anche
          ..........

          PEP 634(2) – Structural Pattern Matching: Specification

          Added in version 3.10.

      -- C Macro: Py_TPFLAGS_VALID_VERSION_TAG

          Internal.  Do not set or unset this flag.  To indicate that a
          class has changed call *note PyType_Modified(): 1b63.

               Avvertimento: This flag is present in header files, but
               is not be used.  It will be removed in a future version
               of CPython

 -- C Membro: const char **note PyTypeObject: c9e.tp_doc

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_doc’ is part of the
     *note ABI Stabile: 776.'

     An optional pointer to a NUL-terminated C string giving the
     docstring for this type object.  This is exposed as the *note
     __doc__: 207f. attribute on the type and instances of the type.

     'Inheritance:'

     This field is 'not' inherited by subtypes.

 -- C Membro: *note traverseproc: 5192. *note PyTypeObject:
          c9e.tp_traverse

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_traverse’ is part
     of the *note ABI Stabile: 776.'

     An optional pointer to a traversal function for the garbage
     collector.  This is only used if the *note Py_TPFLAGS_HAVE_GC: 982.
     flag bit is set.  The signature is:

          int tp_traverse(PyObject *self, visitproc visit, void *arg);

     More information about Python’s garbage collection scheme can be
     found in section *note Supporting Cyclic Garbage Collection: 562f.

     The *note tp_traverse: 983. pointer is used by the garbage
     collector to detect reference cycles.  A typical implementation of
     a *note tp_traverse: 983. function simply calls *note Py_VISIT():
     4ec2. on each of the instance’s members that are Python objects
     that the instance owns.  For example, this is function
     ‘local_traverse()’ from the ‘_thread’ extension module:

          static int
          local_traverse(PyObject *op, visitproc visit, void *arg)
          {
              localobject *self = (localobject *) op;
              Py_VISIT(self->args);
              Py_VISIT(self->kw);
              Py_VISIT(self->dict);
              return 0;
          }

     Note that *note Py_VISIT(): 4ec2. is called only on those members
     that can participate in reference cycles.  Although there is also a
     ‘self->key’ member, it can only be ‘NULL’ or a Python string and
     therefore cannot be part of a reference cycle.

     On the other hand, even if you know a member can never be part of a
     cycle, as a debugging aid you may want to visit it anyway just so
     the *note gc: 64. module’s *note get_referents(): a08. function
     will include it.

     Heap types (*note Py_TPFLAGS_HEAPTYPE: aae.) must visit their type
     with:

          Py_VISIT(Py_TYPE(self));

     It is only needed since Python 3.9.  To support Python 3.8 and
     older, this line must be conditional:

          #if PY_VERSION_HEX >= 0x03090000
              Py_VISIT(Py_TYPE(self));
          #endif

     If the *note Py_TPFLAGS_MANAGED_DICT: 60f. bit is set in the *note
     tp_flags: 1c59. field, the traverse function must call *note
     PyObject_VisitManagedDict(): 60d. like this:

          PyObject_VisitManagedDict((PyObject*)self, visit, arg);

          Avvertimento: When implementing *note tp_traverse: 983, only
          the members that the instance 'owns' (by having *note strong
          references: 5e2. to them) must be visited.  For instance, if
          an object supports weak references via the *note tp_weaklist:
          52c9. slot, the pointer supporting the linked list (what
          'tp_weaklist' points to) must 'not' be visited as the instance
          does not directly own the weak references to itself (the
          weakreference list is there to support the weak reference
          machinery, but the instance has no strong reference to the
          elements inside it, as they are allowed to be removed even if
          the instance is still alive).

          Avvertimento: The traversal function must not have any side
          effects.  It must not modify the reference counts of any
          Python objects nor create or destroy any Python objects.

     Note that *note Py_VISIT(): 4ec2. requires the 'visit' and 'arg'
     parameters to ‘local_traverse()’ to have these specific names;
     don’t name them just anything.

     Instances of *note heap-allocated types: b60. hold a reference to
     their type.  Their traversal function must therefore either visit
     *note Py_TYPE(self): 3c9, or delegate this responsibility by
     calling ‘tp_traverse’ of another heap-allocated type (such as a
     heap-allocated superclass).  If they do not, the type object may
     not be garbage-collected.

          Nota: The *note tp_traverse: 983. function can be called from
          any thread.

     Cambiato nella versione 3.9: Heap-allocated types are expected to
     visit ‘Py_TYPE(self)’ in ‘tp_traverse’.  In earlier versions of
     Python, due to bug 40217(3), doing this may lead to crashes in
     subclasses.

     'Inheritance:'

     Group: *note Py_TPFLAGS_HAVE_GC: 982, *note tp_traverse: 983, *note
     tp_clear: 4ecb.

     This field is inherited by subtypes together with *note tp_clear:
     4ecb. and the *note Py_TPFLAGS_HAVE_GC: 982. flag bit: the flag
     bit, *note tp_traverse: 983, and *note tp_clear: 4ecb. are all
     inherited from the base type if they are all zero in the subtype.

 -- C Membro: *note inquiry: 5183. *note PyTypeObject: c9e.tp_clear

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_clear’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to a clear function.  The signature is:

          int tp_clear(PyObject *);

     The purpose of this function is to break reference cycles that are
     causing a *note cyclic isolate: 55bd. so that the objects can be
     safely destroyed.  A cleared object is a partially destroyed
     object; the object is not obligated to satisfy design invariants
     held during normal use.

     ‘tp_clear’ does not need to delete references to objects that can’t
     participate in reference cycles, such as Python strings or Python
     integers.  However, it may be convenient to clear all references,
     and write the type’s *note tp_dealloc: 4ea5. function to invoke
     ‘tp_clear’ to avoid code duplication.  (Beware that ‘tp_clear’
     might have already been called.  Prefer calling idempotent
     functions like *note Py_CLEAR(): 799.)

     Any non-trivial cleanup should be performed in *note tp_finalize:
     c9f. instead of ‘tp_clear’.

          Nota: If ‘tp_clear’ fails to break a reference cycle then the
          objects in the *note cyclic isolate: 55bd. may remain
          indefinitely uncollectable («leak»).  See *note gc.garbage:
          13c9.

          Nota: Referents (direct and indirect) might have already been
          cleared; they are not guaranteed to be in a consistent state.

          Nota: The *note tp_clear: 4ecb. function can be called from
          any thread.

          Nota: An object is not guaranteed to be automatically cleared
          before its destructor (*note tp_dealloc: 4ea5.) is called.

     This function differs from the destructor (*note tp_dealloc: 4ea5.)
     in the following ways:

        * The purpose of clearing an object is to remove references to
          other objects that might participate in a reference cycle.
          The purpose of the destructor, on the other hand, is a
          superset: it must release 'all' resources it owns, including
          references to objects that cannot participate in a reference
          cycle (e.g., integers) as well as the object’s own memory (by
          calling *note tp_free: 4eb8.).

        * When ‘tp_clear’ is called, other objects might still hold
          references to the object being cleared.  Because of this,
          ‘tp_clear’ must not deallocate the object’s own memory (*note
          tp_free: 4eb8.).  The destructor, on the other hand, is only
          called when no (strong) references exist, and as such, must
          safely destroy the object itself by deallocating it.

        * ‘tp_clear’ might never be automatically called.  An object’s
          destructor, on the other hand, will be automatically called
          some time after the object becomes unreachable (i.e., either
          there are no references to the object or the object is a
          member of a *note cyclic isolate: 55bd.).

     No guarantees are made about when, if, or how often Python
     automatically clears an object, except:

        * Python will not automatically clear an object if it is
          reachable, i.e., there is a reference to it and it is not a
          member of a *note cyclic isolate: 55bd.

        * Python will not automatically clear an object if it has not
          been automatically finalized (see *note tp_finalize: c9f.).
          (If the finalizer resurrected the object, the object may or
          may not be automatically finalized again before it is
          cleared.)

        * If an object is a member of a *note cyclic isolate: 55bd,
          Python will not automatically clear it if any member of the
          cyclic isolate has not yet been automatically finalized (*note
          tp_finalize: c9f.).

        * Python will not destroy an object until after any automatic
          calls to its ‘tp_clear’ function have returned.  This ensures
          that the act of breaking a reference cycle does not invalidate
          the ‘self’ pointer while ‘tp_clear’ is still executing.

        * Python will not automatically call ‘tp_clear’ multiple times
          concurrently.

     CPython currently only automatically clears objects as needed to
     break reference cycles in a *note cyclic isolate: 55bd, but future
     versions might clear objects regularly before their destruction.

     Taken together, all *note tp_clear: 4ecb. functions in the system
     must combine to break all reference cycles.  This is subtle, and if
     in any doubt supply a *note tp_clear: 4ecb. function.  For example,
     the tuple type does not implement a *note tp_clear: 4ecb. function,
     because it’s possible to prove that no reference cycle can be
     composed entirely of tuples.  Therefore the *note tp_clear: 4ecb.
     functions of other types are responsible for breaking any cycle
     containing a tuple.  This isn’t immediately obvious, and there’s
     rarely a good reason to avoid implementing *note tp_clear: 4ecb.

     Implementations of *note tp_clear: 4ecb. should drop the instance’s
     references to those of its members that may be Python objects, and
     set its pointers to those members to ‘NULL’, as in the following
     example:

          static int
          local_clear(PyObject *op)
          {
              localobject *self = (localobject *) op;
              Py_CLEAR(self->key);
              Py_CLEAR(self->args);
              Py_CLEAR(self->kw);
              Py_CLEAR(self->dict);
              return 0;
          }

     The *note Py_CLEAR(): 799. macro should be used, because clearing
     references is delicate: the reference to the contained object must
     not be released (via *note Py_DECREF(): 791.) until after the
     pointer to the contained object is set to ‘NULL’.  This is because
     releasing the reference may cause the contained object to become
     trash, triggering a chain of reclamation activity that may include
     invoking arbitrary Python code (due to finalizers, or weakref
     callbacks, associated with the contained object).  If it’s possible
     for such code to reference 'self' again, it’s important that the
     pointer to the contained object be ‘NULL’ at that time, so that
     'self' knows the contained object can no longer be used.  The *note
     Py_CLEAR(): 799. macro performs the operations in a safe order.

     If the *note Py_TPFLAGS_MANAGED_DICT: 60f. bit is set in the *note
     tp_flags: 1c59. field, the clear function must call *note
     PyObject_ClearManagedDict(): 60e. like this:

          PyObject_ClearManagedDict((PyObject*)self);

     More information about Python’s garbage collection scheme can be
     found in section *note Supporting Cyclic Garbage Collection: 562f.

     'Inheritance:'

     Group: *note Py_TPFLAGS_HAVE_GC: 982, *note tp_traverse: 983, *note
     tp_clear: 4ecb.

     This field is inherited by subtypes together with *note
     tp_traverse: 983. and the *note Py_TPFLAGS_HAVE_GC: 982. flag bit:
     the flag bit, *note tp_traverse: 983, and *note tp_clear: 4ecb. are
     all inherited from the base type if they are all zero in the
     subtype.

     Vedi anche
     ..........

     *note Object Life Cycle: 55b8. for details about how this slot
     relates to other slots.

 -- C Membro: *note richcmpfunc: 518b. *note PyTypeObject:
          c9e.tp_richcompare

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_richcompare’ is
     part of the *note ABI Stabile: 776.'

     An optional pointer to the rich comparison function, whose
     signature is:

          PyObject *tp_richcompare(PyObject *self, PyObject *other, int op);

     The first parameter is guaranteed to be an instance of the type
     that is defined by *note PyTypeObject: c9e.

     The function should return the result of the comparison (usually
     ‘Py_True’ or ‘Py_False’).  If the comparison is undefined, it must
     return ‘Py_NotImplemented’, if another error occurred it must
     return ‘NULL’ and set an exception condition.

     The following constants are defined to be used as the third
     argument for *note tp_richcompare: 4ed9. and for *note
     PyObject_RichCompare(): 4eda.:

     Constant                 Comparison
                              
     ------------------------------------------
                              
      -- C Macro: Py_LT       ‘<’
                              
                              
      -- C Macro: Py_LE       ‘<=’
                              
                              
      -- C Macro: Py_EQ       ‘==’
                              
                              
      -- C Macro: Py_NE       ‘!=’
                              
                              
      -- C Macro: Py_GT       ‘>’
                              
                              
      -- C Macro: Py_GE       ‘>=’
                              

     The following macro is defined to ease writing rich comparison
     functions:

      -- C Macro: Py_RETURN_RICHCOMPARE (VAL_A, VAL_B, op)

          Return ‘Py_True’ or ‘Py_False’ from the function, depending on
          the result of a comparison.  VAL_A and VAL_B must be orderable
          by C comparison operators (for example, they may be C ints or
          floats).  The third argument specifies the requested
          operation, as for *note PyObject_RichCompare(): 4eda.

          The returned value is a new *note strong reference: 5e2.

          On error, sets an exception and returns ‘NULL’ from the
          function.

          Added in version 3.7.

     'Inheritance:'

     Group: *note tp_hash: 4edf, *note tp_richcompare: 4ed9.

     This field is inherited by subtypes together with *note tp_hash:
     4edf.: a subtype inherits *note tp_richcompare: 4ed9. and *note
     tp_hash: 4edf. when the subtype’s *note tp_richcompare: 4ed9. and
     *note tp_hash: 4edf. are both ‘NULL’.

     'Default:'

     *note PyBaseObject_Type: 4f4d. provides a *note tp_richcompare:
     4ed9. implementation, which may be inherited.  However, if only
     *note tp_hash: 4edf. is defined, not even the inherited function is
     used and instances of the type will not be able to participate in
     any comparisons.

 -- C Membro: *note Py_ssize_t: c57. *note PyTypeObject:
          c9e.tp_weaklistoffset

     While this field is still supported, *note
     Py_TPFLAGS_MANAGED_WEAKREF: 77d. should be used instead, if at all
     possible.

     If the instances of this type are weakly referenceable, this field
     is greater than zero and contains the offset in the instance
     structure of the weak reference list head (ignoring the GC header,
     if present); this offset is used by *note PyObject_ClearWeakRefs():
     797. and the ‘PyWeakref_*’ functions.  The instance structure needs
     to include a field of type *note PyObject: 5df.* which is
     initialized to ‘NULL’.

     Do not confuse this field with *note tp_weaklist: 52c9.; that is
     the list head for weak references to the type object itself.

     It is an error to set both the *note Py_TPFLAGS_MANAGED_WEAKREF:
     77d. bit and *note tp_weaklistoffset: b81.

     'Inheritance:'

     This field is inherited by subtypes, but see the rules listed
     below.  A subtype may override this offset; this means that the
     subtype uses a different weak reference list head than the base
     type.  Since the list head is always found via *note
     tp_weaklistoffset: b81, this should not be a problem.

     'Default:'

     If the *note Py_TPFLAGS_MANAGED_WEAKREF: 77d. bit is set in the
     *note tp_flags: 1c59. field, then *note tp_weaklistoffset: b81.
     will be set to a negative value, to indicate that it is unsafe to
     use this field.

 -- C Membro: *note getiterfunc: 517f. *note PyTypeObject: c9e.tp_iter

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_iter’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to a function that returns an *note iterator:
     4c9. for the object.  Its presence normally signals that the
     instances of this type are *note iterable: 142f. (although
     sequences may be iterable without this function).

     This function has the same signature as *note PyObject_GetIter():
     506a.:

          PyObject *tp_iter(PyObject *self);

     'Inheritance:'

     This field is inherited by subtypes.

 -- C Membro: *note iternextfunc: 5184. *note PyTypeObject:
          c9e.tp_iternext

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_iternext’ is part
     of the *note ABI Stabile: 776.'

     An optional pointer to a function that returns the next item in an
     *note iterator: 4c9.  The signature is:

          PyObject *tp_iternext(PyObject *self);

     When the iterator is exhausted, it must return ‘NULL’; a *note
     StopIteration: df7. exception may or may not be set.  When another
     error occurs, it must return ‘NULL’ too.  Its presence signals that
     the instances of this type are iterators.

     Iterator types should also define the *note tp_iter: 16f6.
     function, and that function should return the iterator instance
     itself (not a new iterator instance).

     This function has the same signature as *note PyIter_Next(): 399.

     'Inheritance:'

     This field is inherited by subtypes.

 -- C Membro: struct *note PyMethodDef: 16de. **note PyTypeObject:
          c9e.tp_methods

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_methods’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to a static ‘NULL’-terminated array of *note
     PyMethodDef: 16de. structures, declaring regular methods of this
     type.

     For each entry in the array, an entry is added to the type’s
     dictionary (see *note tp_dict: 1a74. below) containing a method
     descriptor.

     'Inheritance:'

     This field is not inherited by subtypes (methods are inherited
     through a different mechanism).

 -- C Membro: struct *note PyMemberDef: 772. **note PyTypeObject:
          c9e.tp_members

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_members’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to a static ‘NULL’-terminated array of *note
     PyMemberDef: 772. structures, declaring regular data members
     (fields or slots) of instances of this type.

     For each entry in the array, an entry is added to the type’s
     dictionary (see *note tp_dict: 1a74. below) containing a member
     descriptor.

     'Inheritance:'

     This field is not inherited by subtypes (members are inherited
     through a different mechanism).

 -- C Membro: struct *note PyGetSetDef: db4. **note PyTypeObject:
          c9e.tp_getset

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_getset’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to a static ‘NULL’-terminated array of *note
     PyGetSetDef: db4. structures, declaring computed attributes of
     instances of this type.

     For each entry in the array, an entry is added to the type’s
     dictionary (see *note tp_dict: 1a74. below) containing a getset
     descriptor.

     'Inheritance:'

     This field is not inherited by subtypes (computed attributes are
     inherited through a different mechanism).

 -- C Membro: *note PyTypeObject: c9e. **note PyTypeObject: c9e.tp_base

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_base’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to a base type from which type properties are
     inherited.  At this level, only single inheritance is supported;
     multiple inheritance require dynamically creating a type object by
     calling the metatype.

          Nota: 
          Slot initialization is subject to the rules of initializing
          globals.  C99 requires the initializers to be «address
          constants».  Function designators like *note
          PyType_GenericNew(): 4eb5, with implicit conversion to a
          pointer, are valid C99 address constants.

          However, the unary “&” operator applied to a non-static
          variable like *note PyBaseObject_Type: 4f4d. is not required
          to produce an address constant.  Compilers may support this
          (gcc does), MSVC does not.  Both compilers are strictly
          standard conforming in this particular behavior.

          Consequently, *note tp_base: 235c. should be set in the
          extension module’s init function.

     'Inheritance:'

     This field is not inherited by subtypes (obviously).

     'Default:'

     This field defaults to ‘&PyBaseObject_Type’ (which to Python
     programmers is known as the type *note object: c80.).

 -- C Membro: *note PyObject: 5df. **note PyTypeObject: c9e.tp_dict

     The type’s dictionary is stored here by *note PyType_Ready(): 981.

     This field should normally be initialized to ‘NULL’ before
     PyType_Ready is called; it may also be initialized to a dictionary
     containing initial attributes for the type.  Once *note
     PyType_Ready(): 981. has initialized the type, extra attributes for
     the type may be added to this dictionary only if they don’t
     correspond to overloaded operations (like *note __add__(): 23c3.).
     Once initialization for the type has finished, this field should be
     treated as read-only.

     Some types may not store their dictionary in this slot.  Use *note
     PyType_GetDict(): 1a73. to retrieve the dictionary for an arbitrary
     type.

     Cambiato nella versione 3.12: Internals detail: For static builtin
     types, this is always ‘NULL’.  Instead, the dict for such types is
     stored on ‘PyInterpreterState’.  Use *note PyType_GetDict(): 1a73.
     to get the dict for an arbitrary type.

     'Inheritance:'

     This field is not inherited by subtypes (though the attributes
     defined in here are inherited through a different mechanism).

     'Default:'

     If this field is ‘NULL’, *note PyType_Ready(): 981. will assign a
     new dictionary to it.

          Avvertimento: It is not safe to use *note PyDict_SetItem():
          4ea2. on or otherwise modify *note tp_dict: 1a74. with the
          dictionary C-API.

 -- C Membro: *note descrgetfunc: 5179. *note PyTypeObject:
          c9e.tp_descr_get

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_descr_get’ is part
     of the *note ABI Stabile: 776.'

     An optional pointer to a «descriptor get» function.

     The function signature is:

          PyObject * tp_descr_get(PyObject *self, PyObject *obj, PyObject *type);

     'Inheritance:'

     This field is inherited by subtypes.

 -- C Membro: *note descrsetfunc: 517a. *note PyTypeObject:
          c9e.tp_descr_set

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_descr_set’ is part
     of the *note ABI Stabile: 776.'

     An optional pointer to a function for setting and deleting a
     descriptor’s value.

     The function signature is:

          int tp_descr_set(PyObject *self, PyObject *obj, PyObject *value);

     The 'value' argument is set to ‘NULL’ to delete the value.

     'Inheritance:'

     This field is inherited by subtypes.

 -- C Membro: *note Py_ssize_t: c57. *note PyTypeObject:
          c9e.tp_dictoffset

     While this field is still supported, *note Py_TPFLAGS_MANAGED_DICT:
     60f. should be used instead, if at all possible.

     If the instances of this type have a dictionary containing instance
     variables, this field is non-zero and contains the offset in the
     instances of the type of the instance variable dictionary; this
     offset is used by *note PyObject_GenericGetAttr(): 5066.

     Do not confuse this field with *note tp_dict: 1a74.; that is the
     dictionary for attributes of the type object itself.

     The value specifies the offset of the dictionary from the start of
     the instance structure.

     The *note tp_dictoffset: 52c5. should be regarded as write-only.
     To get the pointer to the dictionary call *note
     PyObject_GenericGetDict(): 1ced.  Calling *note
     PyObject_GenericGetDict(): 1ced. may need to allocate memory for
     the dictionary, so it is may be more efficient to call *note
     PyObject_GetAttr(): 5ee. when accessing an attribute on the object.

     It is an error to set both the *note Py_TPFLAGS_MANAGED_DICT: 60f.
     bit and *note tp_dictoffset: 52c5.

     'Inheritance:'

     This field is inherited by subtypes.  A subtype should not override
     this offset; doing so could be unsafe, if C code tries to access
     the dictionary at the previous offset.  To properly support
     inheritance, use *note Py_TPFLAGS_MANAGED_DICT: 60f.

     'Default:'

     This slot has no default.  For *note static types: 984, if the
     field is ‘NULL’ then no *note __dict__: 77e. gets created for
     instances.

     If the *note Py_TPFLAGS_MANAGED_DICT: 60f. bit is set in the *note
     tp_flags: 1c59. field, then *note tp_dictoffset: 52c5. will be set
     to ‘-1’, to indicate that it is unsafe to use this field.

 -- C Membro: *note initproc: 5182. *note PyTypeObject: c9e.tp_init

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_init’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to an instance initialization function.

     This function corresponds to the *note __init__(): 8c0. method of
     classes.  Like ‘__init__()’, it is possible to create an instance
     without calling ‘__init__()’, and it is possible to reinitialize an
     instance by calling its ‘__init__()’ method again.

     The function signature is:

          int tp_init(PyObject *self, PyObject *args, PyObject *kwds);

     The self argument is the instance to be initialized; the 'args' and
     'kwds' arguments represent positional and keyword arguments of the
     call to *note __init__(): 8c0.

     The *note tp_init: 7a2. function, if not ‘NULL’, is called when an
     instance is created normally by calling its type, after the type’s
     *note tp_new: 7a0. function has returned an instance of the type.
     If the *note tp_new: 7a0. function returns an instance of some
     other type that is not a subtype of the original type, no *note
     tp_init: 7a2. function is called; if *note tp_new: 7a0. returns an
     instance of a subtype of the original type, the subtype’s *note
     tp_init: 7a2. is called.

     Returns ‘0’ on success, ‘-1’ and sets an exception on error.

     'Inheritance:'

     This field is inherited by subtypes.

     'Default:'

     For *note static types: 984. this field does not have a default.

 -- C Membro: *note allocfunc: 5177. *note PyTypeObject: c9e.tp_alloc

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_alloc’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to an instance allocation function.

     The function signature is:

          PyObject *tp_alloc(PyTypeObject *self, Py_ssize_t nitems);

     'Inheritance:'

     Static subtypes inherit this slot, which will be *note
     PyType_GenericAlloc(): c63. if inherited from *note object: c80.

     *note Heap subtypes: b60. do not inherit this slot.

     'Default:'

     For heap subtypes, this field is always set to *note
     PyType_GenericAlloc(): c63.

     For static subtypes, this slot is inherited (see above).

 -- C Membro: *note newfunc: 5186. *note PyTypeObject: c9e.tp_new

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_new’ is part of the
     *note ABI Stabile: 776.'

     An optional pointer to an instance creation function.

     The function signature is:

          PyObject *tp_new(PyTypeObject *subtype, PyObject *args, PyObject *kwds);

     The 'subtype' argument is the type of the object being created; the
     'args' and 'kwds' arguments represent positional and keyword
     arguments of the call to the type.  Note that 'subtype' doesn’t
     have to equal the type whose *note tp_new: 7a0. function is called;
     it may be a subtype of that type (but not an unrelated type).

     The *note tp_new: 7a0. function should call
     ‘subtype->tp_alloc(subtype, nitems)’ to allocate space for the
     object, and then do only as much further initialization as is
     absolutely necessary.  Initialization that can safely be ignored or
     repeated should be placed in the *note tp_init: 7a2. handler.  A
     good rule of thumb is that for immutable types, all initialization
     should take place in *note tp_new: 7a0, while for mutable types,
     most initialization should be deferred to *note tp_init: 7a2.

     Set the *note Py_TPFLAGS_DISALLOW_INSTANTIATION: 7a3. flag to
     disallow creating instances of the type in Python.

     'Inheritance:'

     This field is inherited by subtypes, except it is not inherited by
     *note static types: 984. whose *note tp_base: 235c. is ‘NULL’ or
     ‘&PyBaseObject_Type’.

     'Default:'

     For *note static types: 984. this field has no default.  This means
     if the slot is defined as ‘NULL’, the type cannot be called to
     create new instances; presumably there is some other way to create
     instances, like a factory function.

 -- C Membro: *note freefunc: 5422. *note PyTypeObject: c9e.tp_free

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_free’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to an instance deallocation function.  Its
     signature is:

          void tp_free(void *self);

     This function must free the memory allocated by *note tp_alloc:
     4eb9.

     'Inheritance:'

     Static subtypes inherit this slot, which will be *note
     PyObject_Free(): e61. if inherited from *note object: c80.
     Exception: If the type supports garbage collection (i.e., the *note
     Py_TPFLAGS_HAVE_GC: 982. flag is set in *note tp_flags: 1c59.) and
     it would inherit *note PyObject_Free(): e61, then this slot is not
     inherited but instead defaults to *note PyObject_GC_Del(): 170a.

     *note Heap subtypes: b60. do not inherit this slot.

     'Default:'

     For *note heap subtypes: b60, this slot defaults to a deallocator
     suitable to match *note PyType_GenericAlloc(): c63. and the value
     of the *note Py_TPFLAGS_HAVE_GC: 982. flag.

     For static subtypes, this slot is inherited (see above).

 -- C Membro: *note inquiry: 5183. *note PyTypeObject: c9e.tp_is_gc

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_is_gc’ is part of
     the *note ABI Stabile: 776.'

     An optional pointer to a function called by the garbage collector.

     The garbage collector needs to know whether a particular object is
     collectible or not.  Normally, it is sufficient to look at the
     object’s type’s *note tp_flags: 1c59. field, and check the *note
     Py_TPFLAGS_HAVE_GC: 982. flag bit.  But some types have a mixture
     of statically and dynamically allocated instances, and the
     statically allocated instances are not collectible.  Such types
     should define this function; it should return ‘1’ for a collectible
     instance, and ‘0’ for a non-collectible instance.  The signature
     is:

          int tp_is_gc(PyObject *self);

     (The only example of this are types themselves.  The metatype,
     *note PyType_Type: 770, defines this function to distinguish
     between statically and *note dynamically allocated types: b60.)

     'Inheritance:'

     This field is inherited by subtypes.

     'Default:'

     This slot has no default.  If this field is ‘NULL’, *note
     Py_TPFLAGS_HAVE_GC: 982. is used as the functional equivalent.

 -- C Membro: *note PyObject: 5df. **note PyTypeObject: c9e.tp_bases

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_bases’ is part of
     the *note ABI Stabile: 776.'

     Tuple of base types.

     This field should be set to ‘NULL’ and treated as read-only.
     Python will fill it in when the type is *note initialized: 981.

     For dynamically created classes, the *note Py_tp_bases: 515b. *note
     slot: 50b4. can be used instead of the 'bases' argument of *note
     PyType_FromSpecWithBases(): 79f.  The argument form is preferred.

          Avvertimento: Multiple inheritance does not work well for
          statically defined types.  If you set ‘tp_bases’ to a tuple,
          Python will not raise an error, but some slots will only be
          inherited from the first base.

     'Inheritance:'

     This field is not inherited.

 -- C Membro: *note PyObject: 5df. **note PyTypeObject: c9e.tp_mro

     Tuple containing the expanded set of base types, starting with the
     type itself and ending with *note object: c80, in Method Resolution
     Order.

     This field should be set to ‘NULL’ and treated as read-only.
     Python will fill it in when the type is *note initialized: 981.

     'Inheritance:'

     This field is not inherited; it is calculated fresh by *note
     PyType_Ready(): 981.

 -- C Membro: *note PyObject: 5df. **note PyTypeObject: c9e.tp_cache

     Unused.  Internal use only.

     'Inheritance:'

     This field is not inherited.

 -- C Membro: void **note PyTypeObject: c9e.tp_subclasses

     A collection of subclasses.  Internal use only.  May be an invalid
     pointer.

     To get a list of subclasses, call the Python method *note
     __subclasses__(): 794.

     Cambiato nella versione 3.12: For some types, this field does not
     hold a valid *note PyObject: 5df.*.  The type was changed to void*
     to indicate this.

     'Inheritance:'

     This field is not inherited.

 -- C Membro: *note PyObject: 5df. **note PyTypeObject: c9e.tp_weaklist

     Weak reference list head, for weak references to this type object.
     Not inherited.  Internal use only.

     Cambiato nella versione 3.12: Internals detail: For the static
     builtin types this is always ‘NULL’, even if weakrefs are added.
     Instead, the weakrefs for each are stored on ‘PyInterpreterState’.
     Use the public C-API or the internal
     ‘_PyObject_GET_WEAKREFS_LISTPTR()’ macro to avoid the distinction.

     'Inheritance:'

     This field is not inherited.

 -- C Membro: *note destructor: 517b. *note PyTypeObject: c9e.tp_del

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_del’ is part of the
     *note ABI Stabile: 776.'

     This field is deprecated.  Use *note tp_finalize: c9f. instead.

 -- C Membro: unsigned int *note PyTypeObject: c9e.tp_version_tag

     Used to index into the method cache.  Internal use only.

     'Inheritance:'

     This field is not inherited.

 -- C Membro: *note destructor: 517b. *note PyTypeObject:
          c9e.tp_finalize

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_finalize’ is part
     of the *note ABI Stabile: 776. dalla versione 3.5.'

     An optional pointer to an instance finalization function.  This is
     the C implementation of the *note __del__(): 11ff. special method.
     Its signature is:

          void tp_finalize(PyObject *self);

     The primary purpose of finalization is to perform any non-trivial
     cleanup that must be performed before the object is destroyed,
     while the object and any other objects it directly or indirectly
     references are still in a consistent state.  The finalizer is
     allowed to execute arbitrary Python code.

     Before Python automatically finalizes an object, some of the
     object’s direct or indirect referents might have themselves been
     automatically finalized.  However, none of the referents will have
     been automatically cleared (*note tp_clear: 4ecb.) yet.

     Other non-finalized objects might still be using a finalized
     object, so the finalizer must leave the object in a sane state
     (e.g., invariants are still met).

          Nota: After Python automatically finalizes an object, Python
          might start automatically clearing (*note tp_clear: 4ecb.) the
          object and its referents (direct and indirect).  Cleared
          objects are not guaranteed to be in a consistent state; a
          finalized object must be able to tolerate cleared referents.

          Nota: An object is not guaranteed to be automatically
          finalized before its destructor (*note tp_dealloc: 4ea5.) is
          called.  It is recommended to call *note
          PyObject_CallFinalizerFromDealloc(): 55bc. at the beginning of
          ‘tp_dealloc’ to guarantee that the object is always finalized
          before destruction.

          Nota: The *note tp_finalize: c9f. function can be called from
          any thread, although the *note GIL: 164. will be held.

          Nota: The ‘tp_finalize’ function can be called during
          shutdown, after some global variables have been deleted.  See
          the documentation of the *note __del__(): 11ff. method for
          details.

     When Python finalizes an object, it behaves like the following
     algorithm:

       1. Python might mark the object as 'finalized'.  Currently,
          Python always marks objects whose type supports garbage
          collection (i.e., the *note Py_TPFLAGS_HAVE_GC: 982. flag is
          set in *note tp_flags: 1c59.) and never marks other types of
          objects; this might change in a future version.

       2. If the object is not marked as 'finalized' and its
          ‘tp_finalize’ finalizer function is non-‘NULL’, the finalizer
          function is called.

       3. If the finalizer function was called and the finalizer made
          the object reachable (i.e., there is a reference to the object
          and it is not a member of a *note cyclic isolate: 55bd.), then
          the finalizer is said to have 'resurrected' the object.  It is
          unspecified whether the finalizer can also resurrect the
          object by adding a new reference to the object that does not
          make it reachable, i.e., the object is (still) a member of a
          cyclic isolate.

       4. If the finalizer resurrected the object, the object’s pending
          destruction is canceled and the object’s 'finalized' mark
          might be removed if present.  Currently, Python never removes
          the 'finalized' mark; this might change in a future version.

     'Automatic finalization' refers to any finalization performed by
     Python except via calls to *note PyObject_CallFinalizer(): 55c0. or
     *note PyObject_CallFinalizerFromDealloc(): 55bc.  No guarantees are
     made about when, if, or how often an object is automatically
     finalized, except:

        * Python will not automatically finalize an object if it is
          reachable, i.e., there is a reference to it and it is not a
          member of a *note cyclic isolate: 55bd.

        * Python will not automatically finalize an object if finalizing
          it would not mark the object as 'finalized'.  Currently, this
          applies to objects whose type does not support garbage
          collection, i.e., the *note Py_TPFLAGS_HAVE_GC: 982. flag is
          not set.  Such objects can still be manually finalized by
          calling *note PyObject_CallFinalizer(): 55c0. or *note
          PyObject_CallFinalizerFromDealloc(): 55bc.

        * Python will not automatically finalize any two members of a
          *note cyclic isolate: 55bd. concurrently.

        * Python will not automatically finalize an object after it has
          automatically cleared (*note tp_clear: 4ecb.) the object.

        * If an object is a member of a *note cyclic isolate: 55bd,
          Python will not automatically finalize it after automatically
          clearing (see *note tp_clear: 4ecb.) any other member.

        * Python will automatically finalize every member of a *note
          cyclic isolate: 55bd. before it automatically clears (see
          *note tp_clear: 4ecb.) any of them.

        * If Python is going to automatically clear an object (*note
          tp_clear: 4ecb.), it will automatically finalize the object
          first.

     Python currently only automatically finalizes objects that are
     members of a *note cyclic isolate: 55bd, but future versions might
     finalize objects regularly before their destruction.

     To manually finalize an object, do not call this function directly;
     call *note PyObject_CallFinalizer(): 55c0. or *note
     PyObject_CallFinalizerFromDealloc(): 55bc. instead.

     *note tp_finalize: c9f. should leave the current exception status
     unchanged.  The recommended way to write a non-trivial finalizer is
     to back up the exception at the beginning by calling *note
     PyErr_GetRaisedException(): 429. and restore the exception at the
     end by calling *note PyErr_SetRaisedException(): 42c.  If an
     exception is encountered in the middle of the finalizer, log and
     clear it with *note PyErr_WriteUnraisable(): 5f2. or *note
     PyErr_FormatUnraisable(): 5f1.  For example:

          static void
          foo_finalize(PyObject *self)
          {
              // Save the current exception, if any.
              PyObject *exc = PyErr_GetRaisedException();

              // ...

              if (do_something_that_might_raise() != success_indicator) {
                  PyErr_WriteUnraisable(self);
                  goto done;
              }

          done:
              // Restore the saved exception.  This silently discards any exception
              // raised above, so be sure to call PyErr_WriteUnraisable first if
              // necessary.
              PyErr_SetRaisedException(exc);
          }

     'Inheritance:'

     This field is inherited by subtypes.

     Added in version 3.4.

     Cambiato nella versione 3.8: Before version 3.8 it was necessary to
     set the *note Py_TPFLAGS_HAVE_FINALIZE: 427. flags bit in order for
     this field to be used.  This is no longer required.

     Vedi anche
     ..........

        * PEP 442(4): «Safe object finalization»

        * *note Object Life Cycle: 55b8. for details about how this slot
          relates to other slots.

        * *note PyObject_CallFinalizer(): 55c0.

        * *note PyObject_CallFinalizerFromDealloc(): 55bc.

 -- C Membro: *note vectorcallfunc: 77a. *note PyTypeObject:
          c9e.tp_vectorcall

     ' The corresponding *note slot ID: 50b4. ‘Py_tp_vectorcall’ is part
     of the *note ABI Stabile: 776. dalla versione 3.14.'

     A *note vectorcall function: 775. to use for calls of this type
     object (rather than instances).  In other words, ‘tp_vectorcall’
     can be used to optimize ‘type.__call__’, which typically returns a
     new instance of 'type'.

     As with any vectorcall function, if ‘tp_vectorcall’ is ‘NULL’, the
     'tp_call' protocol (‘Py_TYPE(type)->tp_call’) is used instead.

          Nota: The *note vectorcall protocol: 775. requires that the
          vectorcall function has the same behavior as the corresponding
          ‘tp_call’.  This means that ‘type->tp_vectorcall’ must match
          the behavior of ‘Py_TYPE(type)->tp_call’.

          Specifically, if 'type' uses the default metaclass,
          ‘type->tp_vectorcall’ must behave the same as *note
          PyType_Type: 770.->tp_call, which:

             - calls ‘type->tp_new’,

             - if the result is a subclass of 'type', calls
               ‘type->tp_init’ on the result of ‘tp_new’, and

             - returns the result of ‘tp_new’.

          Typically, ‘tp_vectorcall’ is overridden to optimize this
          process for specific *note tp_new: 7a0. and *note tp_init:
          7a2.  When doing this for user-subclassable types, note that
          both can be overridden (using *note __new__(): 7a1. and *note
          __init__(): 8c0, respectively).

     'Inheritance:'

     This field is never inherited.

     Added in version 3.9: (the field exists since 3.8 but it’s only
     used since 3.9)

 -- C Membro: unsigned char *note PyTypeObject: c9e.tp_watched

     Internal.  Do not use.

     Added in version 3.12.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0634/

   (2) https://peps.python.org/pep-0634/

   (3) https://bugs.python.org/issue40217

   (4) https://peps.python.org/pep-0442/


File: python.info,  Node: Static Types,  Next: Heap Types,  Prev: PyTypeObject Slots,  Up: Type Object Structures

7.13.4.9 Static Types
.....................

Traditionally, types defined in C code are 'static', that is, a static
*note PyTypeObject: c9e. structure is defined directly in code and
initialized using *note PyType_Ready(): 981.

This results in types that are limited relative to types defined in
Python:

   * Static types are limited to one base, i.e.  they cannot use
     multiple inheritance.

   * Static type objects (but not necessarily their instances) are
     immutable.  It is not possible to add or modify the type object’s
     attributes from Python.

   * Static type objects are shared across *note sub-interpreters: 163,
     so they should not include any subinterpreter-specific state.

Also, since *note PyTypeObject: c9e. is only part of the *note Limited
API: 637. as an opaque struct, any extension modules using static types
must be compiled for a specific Python minor version.


File: python.info,  Node: Heap Types,  Next: Number Object Structures,  Prev: Static Types,  Up: Type Object Structures

7.13.4.10 Heap Types
....................

An alternative to *note static types: 984. is 'heap-allocated types', or
'heap types' for short, which correspond closely to classes created by
Python’s ‘class’ statement.  Heap types have the *note
Py_TPFLAGS_HEAPTYPE: aae. flag set.

This is done by filling a *note PyType_Spec: 1a71. structure and calling
*note PyType_FromSpec(): 79e, *note PyType_FromSpecWithBases(): 79f,
*note PyType_FromModuleAndSpec(): 774, or *note PyType_FromMetaclass():
773.


File: python.info,  Node: Number Object Structures,  Next: Mapping Object Structures,  Prev: Heap Types,  Up: Type Object Structures

7.13.4.11 Number Object Structures
..................................

 -- C Tipo: type PyNumberMethods

     This structure holds pointers to the functions which an object uses
     to implement the number protocol.  Each function is used by the
     function of similar name documented in the *note Number Protocol:
     5279. section.

     Here is the structure definition:

          typedef struct {
               binaryfunc nb_add;
               binaryfunc nb_subtract;
               binaryfunc nb_multiply;
               binaryfunc nb_remainder;
               binaryfunc nb_divmod;
               ternaryfunc nb_power;
               unaryfunc nb_negative;
               unaryfunc nb_positive;
               unaryfunc nb_absolute;
               inquiry nb_bool;
               unaryfunc nb_invert;
               binaryfunc nb_lshift;
               binaryfunc nb_rshift;
               binaryfunc nb_and;
               binaryfunc nb_xor;
               binaryfunc nb_or;
               unaryfunc nb_int;
               void *nb_reserved;
               unaryfunc nb_float;

               binaryfunc nb_inplace_add;
               binaryfunc nb_inplace_subtract;
               binaryfunc nb_inplace_multiply;
               binaryfunc nb_inplace_remainder;
               ternaryfunc nb_inplace_power;
               binaryfunc nb_inplace_lshift;
               binaryfunc nb_inplace_rshift;
               binaryfunc nb_inplace_and;
               binaryfunc nb_inplace_xor;
               binaryfunc nb_inplace_or;

               binaryfunc nb_floor_divide;
               binaryfunc nb_true_divide;
               binaryfunc nb_inplace_floor_divide;
               binaryfunc nb_inplace_true_divide;

               unaryfunc nb_index;

               binaryfunc nb_matrix_multiply;
               binaryfunc nb_inplace_matrix_multiply;
          } PyNumberMethods;

          Nota: Binary and ternary functions must check the type of all
          their operands, and implement the necessary conversions (at
          least one of the operands is an instance of the defined type).
          If the operation is not defined for the given operands, binary
          and ternary functions must return ‘Py_NotImplemented’, if
          another error occurred they must return ‘NULL’ and set an
          exception.

          Nota: The *note nb_reserved: 5615. field should always be
          ‘NULL’.  It was previously called ‘nb_long’, and was renamed
          in Python 3.0.1.

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods: 1625.nb_add

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_add’ is part of the
     *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_subtract

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_subtract’ is part
     of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_multiply

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_multiply’ is part
     of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_remainder

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_remainder’ is part
     of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_divmod

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_divmod’ is part of
     the *note ABI Stabile: 776.'

 -- C Membro: *note ternaryfunc: 5191. *note PyNumberMethods:
          1625.nb_power

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_power’ is part of
     the *note ABI Stabile: 776.'

 -- C Membro: *note unaryfunc: 5193. *note PyNumberMethods:
          1625.nb_negative

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_negative’ is part
     of the *note ABI Stabile: 776.'

 -- C Membro: *note unaryfunc: 5193. *note PyNumberMethods:
          1625.nb_positive

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_positive’ is part
     of the *note ABI Stabile: 776.'

 -- C Membro: *note unaryfunc: 5193. *note PyNumberMethods:
          1625.nb_absolute

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_absolute’ is part
     of the *note ABI Stabile: 776.'

 -- C Membro: *note inquiry: 5183. *note PyNumberMethods: 1625.nb_bool

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_bool’ is part of
     the *note ABI Stabile: 776.'

 -- C Membro: *note unaryfunc: 5193. *note PyNumberMethods:
          1625.nb_invert

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_invert’ is part of
     the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_lshift

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_lshift’ is part of
     the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_rshift

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_rshift’ is part of
     the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods: 1625.nb_and

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_and’ is part of the
     *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods: 1625.nb_xor

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_xor’ is part of the
     *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods: 1625.nb_or

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_or’ is part of the
     *note ABI Stabile: 776.'

 -- C Membro: *note unaryfunc: 5193. *note PyNumberMethods: 1625.nb_int

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_int’ is part of the
     *note ABI Stabile: 776.'

 -- C Membro: void **note PyNumberMethods: 1625.nb_reserved

 -- C Membro: *note unaryfunc: 5193. *note PyNumberMethods:
          1625.nb_float

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_float’ is part of
     the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_add

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_inplace_add’ is
     part of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_subtract

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_inplace_subtract’
     is part of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_multiply

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_inplace_multiply’
     is part of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_remainder

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_inplace_remainder’
     is part of the *note ABI Stabile: 776.'

 -- C Membro: *note ternaryfunc: 5191. *note PyNumberMethods:
          1625.nb_inplace_power

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_inplace_power’ is
     part of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_lshift

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_inplace_lshift’ is
     part of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_rshift

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_inplace_rshift’ is
     part of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_and

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_inplace_and’ is
     part of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_xor

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_inplace_xor’ is
     part of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_or

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_inplace_or’ is part
     of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_floor_divide

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_floor_divide’ is
     part of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_true_divide

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_true_divide’ is
     part of the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_floor_divide

     ' The corresponding *note slot ID: 50b4.
     ‘Py_nb_inplace_floor_divide’ is part of the *note ABI Stabile:
     776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_true_divide

     ' The corresponding *note slot ID: 50b4.
     ‘Py_nb_inplace_true_divide’ is part of the *note ABI Stabile: 776.'

 -- C Membro: *note unaryfunc: 5193. *note PyNumberMethods:
          1625.nb_index

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_index’ is part of
     the *note ABI Stabile: 776.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_matrix_multiply

     ' The corresponding *note slot ID: 50b4. ‘Py_nb_matrix_multiply’ is
     part of the *note ABI Stabile: 776. dalla versione 3.5.'

 -- C Membro: *note binaryfunc: 5178. *note PyNumberMethods:
          1625.nb_inplace_matrix_multiply

     ' The corresponding *note slot ID: 50b4.
     ‘Py_nb_inplace_matrix_multiply’ is part of the *note ABI Stabile:
     776. dalla versione 3.5.'


File: python.info,  Node: Mapping Object Structures,  Next: Sequence Object Structures,  Prev: Number Object Structures,  Up: Type Object Structures

7.13.4.12 Mapping Object Structures
...................................

 -- C Tipo: type PyMappingMethods

     This structure holds pointers to the functions which an object uses
     to implement the mapping protocol.  It has three members:

 -- C Membro: *note lenfunc: 5185. *note PyMappingMethods:
          4ede.mp_length

     ' The corresponding *note slot ID: 50b4. ‘Py_mp_length’ is part of
     the *note ABI Stabile: 776.'

     This function is used by *note PyMapping_Size(): 1e1f. and *note
     PyObject_Size(): 5070, and has the same signature.  This slot may
     be set to ‘NULL’ if the object has no defined length.

 -- C Membro: *note binaryfunc: 5178. *note PyMappingMethods:
          4ede.mp_subscript

     ' The corresponding *note slot ID: 50b4. ‘Py_mp_subscript’ is part
     of the *note ABI Stabile: 776.'

     This function is used by *note PyObject_GetItem(): 5ea. and *note
     PySequence_GetSlice(): 507c, and has the same signature as
     ‘PyObject_GetItem()’.  This slot must be filled for the *note
     PyMapping_Check(): 5029. function to return ‘1’, it can be ‘NULL’
     otherwise.

 -- C Membro: *note objobjargproc: 5187. *note PyMappingMethods:
          4ede.mp_ass_subscript

     ' The corresponding *note slot ID: 50b4. ‘Py_mp_ass_subscript’ is
     part of the *note ABI Stabile: 776.'

     This function is used by *note PyObject_SetItem(): 4f20, *note
     PyObject_DelItem(): 5062, *note PySequence_SetSlice(): 5083. and
     *note PySequence_DelSlice(): 507b.  It has the same signature as
     ‘PyObject_SetItem()’, but 'v' can also be set to ‘NULL’ to delete
     an item.  If this slot is ‘NULL’, the object does not support item
     assignment and deletion.


File: python.info,  Node: Sequence Object Structures,  Next: Buffer Object Structures,  Prev: Mapping Object Structures,  Up: Type Object Structures

7.13.4.13 Sequence Object Structures
....................................

 -- C Tipo: type PySequenceMethods

     This structure holds pointers to the functions which an object uses
     to implement the sequence protocol.

 -- C Membro: *note lenfunc: 5185. *note PySequenceMethods:
          4edd.sq_length

     ' The corresponding *note slot ID: 50b4. ‘Py_sq_length’ is part of
     the *note ABI Stabile: 776.'

     This function is used by *note PySequence_Size(): 1e1b. and *note
     PyObject_Size(): 5070, and has the same signature.  It is also used
     for handling negative indices via the *note sq_item: 1cdd. and the
     *note sq_ass_item: 5621. slots.

 -- C Membro: *note binaryfunc: 5178. *note PySequenceMethods:
          4edd.sq_concat

     ' The corresponding *note slot ID: 50b4. ‘Py_sq_concat’ is part of
     the *note ABI Stabile: 776.'

     This function is used by *note PySequence_Concat(): 5079. and has
     the same signature.  It is also used by the ‘+’ operator, after
     trying the numeric addition via the *note nb_add: 52bb. slot.

 -- C Membro: *note ssizeargfunc: 518f. *note PySequenceMethods:
          4edd.sq_repeat

     ' The corresponding *note slot ID: 50b4. ‘Py_sq_repeat’ is part of
     the *note ABI Stabile: 776.'

     This function is used by *note PySequence_Repeat(): 5082. and has
     the same signature.  It is also used by the ‘*’ operator, after
     trying numeric multiplication via the *note nb_multiply: 55fe.
     slot.

 -- C Membro: *note ssizeargfunc: 518f. *note PySequenceMethods:
          4edd.sq_item

     ' The corresponding *note slot ID: 50b4. ‘Py_sq_item’ is part of
     the *note ABI Stabile: 776.'

     This function is used by *note PySequence_GetItem(): 1e1c. and has
     the same signature.  It is also used by *note PyObject_GetItem():
     5ea, after trying the subscription via the *note mp_subscript:
     1cde. slot.  This slot must be filled for the *note
     PySequence_Check(): 5078. function to return ‘1’, it can be ‘NULL’
     otherwise.

     Negative indexes are handled as follows: if the *note sq_length:
     52c4. slot is filled, it is called and the sequence length is used
     to compute a positive index which is passed to *note sq_item: 1cdd.
     If ‘sq_length’ is ‘NULL’, the index is passed as is to the
     function.

 -- C Membro: *note ssizeobjargproc: 5190. *note PySequenceMethods:
          4edd.sq_ass_item

     ' The corresponding *note slot ID: 50b4. ‘Py_sq_ass_item’ is part
     of the *note ABI Stabile: 776.'

     This function is used by *note PySequence_SetItem(): 1e1d. and has
     the same signature.  It is also used by *note PyObject_SetItem():
     4f20. and *note PyObject_DelItem(): 5062, after trying the item
     assignment and deletion via the *note mp_ass_subscript: 561e. slot.
     This slot may be left to ‘NULL’ if the object does not support item
     assignment and deletion.

 -- C Membro: *note objobjproc: 5188. *note PySequenceMethods:
          4edd.sq_contains

     ' The corresponding *note slot ID: 50b4. ‘Py_sq_contains’ is part
     of the *note ABI Stabile: 776.'

     This function may be used by *note PySequence_Contains(): 3d9. and
     has the same signature.  This slot may be left to ‘NULL’, in this
     case ‘PySequence_Contains()’ simply traverses the sequence until it
     finds a match.

 -- C Membro: *note binaryfunc: 5178. *note PySequenceMethods:
          4edd.sq_inplace_concat

     ' The corresponding *note slot ID: 50b4. ‘Py_sq_inplace_concat’ is
     part of the *note ABI Stabile: 776.'

     This function is used by *note PySequence_InPlaceConcat(): 507d.
     and has the same signature.  It should modify its first operand,
     and return it.  This slot may be left to ‘NULL’, in this case
     ‘PySequence_InPlaceConcat()’ will fall back to *note
     PySequence_Concat(): 5079.  It is also used by the augmented
     assignment ‘+=’, after trying numeric in-place addition via the
     *note nb_inplace_add: 55fb. slot.

 -- C Membro: *note ssizeargfunc: 518f. *note PySequenceMethods:
          4edd.sq_inplace_repeat

     ' The corresponding *note slot ID: 50b4. ‘Py_sq_inplace_repeat’ is
     part of the *note ABI Stabile: 776.'

     This function is used by *note PySequence_InPlaceRepeat(): 507e.
     and has the same signature.  It should modify its first operand,
     and return it.  This slot may be left to ‘NULL’, in this case
     ‘PySequence_InPlaceRepeat()’ will fall back to *note
     PySequence_Repeat(): 5082.  It is also used by the augmented
     assignment ‘*=’, after trying numeric in-place multiplication via
     the *note nb_inplace_multiply: 55ff. slot.


File: python.info,  Node: Buffer Object Structures,  Next: Async Object Structures,  Prev: Sequence Object Structures,  Up: Type Object Structures

7.13.4.14 Buffer Object Structures
..................................

 -- C Tipo: type PyBufferProcs

     This structure holds pointers to the functions required by the
     *note Buffer protocol: 260.  The protocol defines how an exporter
     object can expose its internal data to consumer objects.

 -- C Membro: *note getbufferproc: 517e. *note PyBufferProcs:
          52ca.bf_getbuffer

     ' The corresponding *note slot ID: 50b4. ‘Py_bf_getbuffer’ is part
     of the *note ABI Stabile: 776. dalla versione 3.11.'

     The signature of this function is:

          int (PyObject *exporter, Py_buffer *view, int flags);

     Handle a request to 'exporter' to fill in 'view' as specified by
     'flags'.  Except for point (3), an implementation of this function
     MUST take these steps:

       1. Check if the request can be met.  If not, raise *note
          BufferError: 177f, set view->obj to ‘NULL’ and return ‘-1’.

       2. Fill in the requested fields.

       3. Increment an internal counter for the number of exports.

       4. Set view->obj to 'exporter' and increment view->obj.

       5. Return ‘0’.

     If 'exporter' is part of a chain or tree of buffer providers, two
     main schemes can be used:

        * Re-export: Each member of the tree acts as the exporting
          object and sets view->obj to a new reference to itself.

        * Redirect: The buffer request is redirected to the root object
          of the tree.  Here, view->obj will be a new reference to the
          root object.

     The individual fields of 'view' are described in section *note
     Buffer structure: 5291, the rules how an exporter must react to
     specific requests are in section *note Buffer request types: 4a46.

     All memory pointed to in the *note Py_buffer: 95d. structure
     belongs to the exporter and must remain valid until there are no
     consumers left.  *note format: 529a, *note shape: 529b, *note
     strides: 5295, *note suboffsets: 529d. and *note internal: 529f.
     are read-only for the consumer.

     *note PyBuffer_FillInfo(): 965. provides an easy way of exposing a
     simple bytes buffer while dealing correctly with all request types.

     *note PyObject_GetBuffer(): 63a. is the interface for the consumer
     that wraps this function.

 -- C Membro: *note releasebufferproc: 5189. *note PyBufferProcs:
          52ca.bf_releasebuffer

     ' The corresponding *note slot ID: 50b4. ‘Py_bf_releasebuffer’ is
     part of the *note ABI Stabile: 776. dalla versione 3.11.'

     The signature of this function is:

          void (PyObject *exporter, Py_buffer *view);

     Handle a request to release the resources of the buffer.  If no
     resources need to be released, *note
     PyBufferProcs.bf_releasebuffer: 968. may be ‘NULL’.  Otherwise, a
     standard implementation of this function will take these optional
     steps:

       1. Decrement an internal counter for the number of exports.

       2. If the counter is ‘0’, free all memory associated with 'view'.

     The exporter MUST use the *note internal: 529f. field to keep track
     of buffer-specific resources.  This field is guaranteed to remain
     constant, while a consumer MAY pass a copy of the original buffer
     as the 'view' argument.

     This function MUST NOT decrement view->obj, since that is done
     automatically in *note PyBuffer_Release(): 63b. (this scheme is
     useful for breaking reference cycles).

     *note PyBuffer_Release(): 63b. is the interface for the consumer
     that wraps this function.


File: python.info,  Node: Async Object Structures,  Next: Slot Type typedefs,  Prev: Buffer Object Structures,  Up: Type Object Structures

7.13.4.15 Async Object Structures
.................................

Added in version 3.5.

 -- C Tipo: type PyAsyncMethods

     This structure holds pointers to the functions required to
     implement *note awaitable: 4ca. and *note asynchronous iterator:
     4c8. objects.

     Here is the structure definition:

          typedef struct {
              unaryfunc am_await;
              unaryfunc am_aiter;
              unaryfunc am_anext;
              sendfunc am_send;
          } PyAsyncMethods;

 -- C Membro: *note unaryfunc: 5193. *note PyAsyncMethods: 52c3.am_await

     ' The corresponding *note slot ID: 50b4. ‘Py_am_await’ is part of
     the *note ABI Stabile: 776. dalla versione 3.5.'

     The signature of this function is:

          PyObject *am_await(PyObject *self);

     The returned object must be an *note iterator: 4c9, i.e.  *note
     PyIter_Check(): 1c9a. must return ‘1’ for it.

     This slot may be set to ‘NULL’ if an object is not an *note
     awaitable: 4ca.

 -- C Membro: *note unaryfunc: 5193. *note PyAsyncMethods: 52c3.am_aiter

     ' The corresponding *note slot ID: 50b4. ‘Py_am_aiter’ is part of
     the *note ABI Stabile: 776. dalla versione 3.5.'

     The signature of this function is:

          PyObject *am_aiter(PyObject *self);

     Must return an *note asynchronous iterator: 4c8. object.  See *note
     __anext__(): 186a. for details.

     This slot may be set to ‘NULL’ if an object does not implement
     asynchronous iteration protocol.

 -- C Membro: *note unaryfunc: 5193. *note PyAsyncMethods: 52c3.am_anext

     ' The corresponding *note slot ID: 50b4. ‘Py_am_anext’ is part of
     the *note ABI Stabile: 776. dalla versione 3.5.'

     The signature of this function is:

          PyObject *am_anext(PyObject *self);

     Must return an *note awaitable: 4ca. object.  See *note
     __anext__(): 186a. for details.  This slot may be set to ‘NULL’.

 -- C Membro: *note sendfunc: 55fa. *note PyAsyncMethods: 52c3.am_send

     ' The corresponding *note slot ID: 50b4. ‘Py_am_send’ is part of
     the *note ABI Stabile: 776. dalla versione 3.10.'

     The signature of this function is:

          PySendResult am_send(PyObject *self, PyObject *arg, PyObject **result);

     See *note PyIter_Send(): a9a. for details.  This slot may be set to
     ‘NULL’.

     Added in version 3.10.


File: python.info,  Node: Slot Type typedefs,  Next: Examples<39>,  Prev: Async Object Structures,  Up: Type Object Structures

7.13.4.16 Slot Type typedefs
............................

 -- C Tipo: typedef *note PyObject: 5df. *(*allocfunc)(*note
          PyTypeObject: c9e. *cls, *note Py_ssize_t: c57. nitems)
     ' Parte del *note ABI Stabile: 776.'  The purpose of this function
     is to separate memory allocation from memory initialization.  It
     should return a pointer to a block of memory of adequate length for
     the instance, suitably aligned, and initialized to zeros, but with
     *note ob_refcnt: aa1. set to ‘1’ and *note ob_type: 4eb6. set to
     the type argument.  If the type’s *note tp_itemsize: 23a1. is
     non-zero, the object’s *note ob_size: 50f4. field should be
     initialized to 'nitems' and the length of the allocated memory
     block should be ‘tp_basicsize + nitems*tp_itemsize’, rounded up to
     a multiple of ‘sizeof(void*)’; otherwise, 'nitems' is not used and
     the length of the block should be *note tp_basicsize: b80.

     This function should not do any other instance initialization, not
     even to allocate additional memory; that should be done by *note
     tp_new: 7a0.

 -- C Tipo: typedef void (*destructor)(*note PyObject: 5df.*)
     ' Parte del *note ABI Stabile: 776.'

 -- C Tipo: typedef void (*freefunc)(void*)

     See *note tp_free: 4eb8.

 -- C Tipo: typedef *note PyObject: 5df. *(*newfunc)(*note PyTypeObject:
          c9e.*, *note PyObject: 5df.*, *note PyObject: 5df.*)
     ' Parte del *note ABI Stabile: 776.'  See *note tp_new: 7a0.

 -- C Tipo: typedef int (*initproc)(*note PyObject: 5df.*, *note
          PyObject: 5df.*, *note PyObject: 5df.*)
     ' Parte del *note ABI Stabile: 776.'  See *note tp_init: 7a2.

 -- C Tipo: typedef *note PyObject: 5df. *(*reprfunc)(*note PyObject:
          5df.*)
     ' Parte del *note ABI Stabile: 776.'  See *note tp_repr: 4ecd.

 -- C Tipo: typedef *note PyObject: 5df. *(*getattrfunc)(*note PyObject:
          5df. *self, char *attr)
     ' Parte del *note ABI Stabile: 776.'  Return the value of the named
     attribute for the object.

 -- C Tipo: typedef int (*setattrfunc)(*note PyObject: 5df. *self, char
          *attr, *note PyObject: 5df. *value)
     ' Parte del *note ABI Stabile: 776.'  Set the value of the named
     attribute for the object.  The value argument is set to ‘NULL’ to
     delete the attribute.

 -- C Tipo: typedef *note PyObject: 5df. *(*getattrofunc)(*note
          PyObject: 5df. *self, *note PyObject: 5df. *attr)
     ' Parte del *note ABI Stabile: 776.'  Return the value of the named
     attribute for the object.

     See *note tp_getattro: 1a4c.

 -- C Tipo: typedef int (*setattrofunc)(*note PyObject: 5df. *self,
          *note PyObject: 5df. *attr, *note PyObject: 5df. *value)
     ' Parte del *note ABI Stabile: 776.'  Set the value of the named
     attribute for the object.  The value argument is set to ‘NULL’ to
     delete the attribute.

     See *note tp_setattro: 4ed1.

 -- C Tipo: typedef *note PyObject: 5df. *(*descrgetfunc)(*note
          PyObject: 5df.*, *note PyObject: 5df.*, *note PyObject: 5df.*)
     ' Parte del *note ABI Stabile: 776.'  See *note tp_descr_get: 55ef.

 -- C Tipo: typedef int (*descrsetfunc)(*note PyObject: 5df.*, *note
          PyObject: 5df.*, *note PyObject: 5df.*)
     ' Parte del *note ABI Stabile: 776.'  See *note tp_descr_set: 1c9c.

 -- C Tipo: typedef *note Py_hash_t: 146b. (*hashfunc)(*note PyObject:
          5df.*)
     ' Parte del *note ABI Stabile: 776.'  See *note tp_hash: 4edf.

 -- C Tipo: typedef *note PyObject: 5df. *(*richcmpfunc)(*note PyObject:
          5df.*, *note PyObject: 5df.*, int)
     ' Parte del *note ABI Stabile: 776.'  See *note tp_richcompare:
     4ed9.

 -- C Tipo: typedef *note PyObject: 5df. *(*getiterfunc)(*note PyObject:
          5df.*)
     ' Parte del *note ABI Stabile: 776.'  See *note tp_iter: 16f6.

 -- C Tipo: typedef *note PyObject: 5df. *(*iternextfunc)(*note
          PyObject: 5df.*)
     ' Parte del *note ABI Stabile: 776.'  See *note tp_iternext: 16f7.

 -- C Tipo: typedef *note Py_ssize_t: c57. (*lenfunc)(*note PyObject:
          5df.*)
     ' Parte del *note ABI Stabile: 776.'

 -- C Tipo: typedef int (*getbufferproc)(*note PyObject: 5df.*, *note
          Py_buffer: 95d.*, int)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'

 -- C Tipo: typedef void (*releasebufferproc)(*note PyObject: 5df.*,
          *note Py_buffer: 95d.*)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.12.'

 -- C Tipo: typedef *note PyObject: 5df. *(*unaryfunc)(*note PyObject:
          5df.*)
     ' Parte del *note ABI Stabile: 776.'

 -- C Tipo: typedef *note PyObject: 5df. *(*binaryfunc)(*note PyObject:
          5df.*, *note PyObject: 5df.*)
     ' Parte del *note ABI Stabile: 776.'

 -- C Tipo: typedef *note PySendResult: 528c. (*sendfunc)(*note
          PyObject: 5df.*, *note PyObject: 5df.*, *note PyObject:
          5df.**)

     See *note am_send: 55f9.

 -- C Tipo: typedef *note PyObject: 5df. *(*ternaryfunc)(*note PyObject:
          5df.*, *note PyObject: 5df.*, *note PyObject: 5df.*)
     ' Parte del *note ABI Stabile: 776.'

 -- C Tipo: typedef *note PyObject: 5df. *(*ssizeargfunc)(*note
          PyObject: 5df.*, *note Py_ssize_t: c57.)
     ' Parte del *note ABI Stabile: 776.'

 -- C Tipo: typedef int (*ssizeobjargproc)(*note PyObject: 5df.*, *note
          Py_ssize_t: c57, *note PyObject: 5df.*)
     ' Parte del *note ABI Stabile: 776.'

 -- C Tipo: typedef int (*objobjproc)(*note PyObject: 5df.*, *note
          PyObject: 5df.*)
     ' Parte del *note ABI Stabile: 776.'

 -- C Tipo: typedef int (*objobjargproc)(*note PyObject: 5df.*, *note
          PyObject: 5df.*, *note PyObject: 5df.*)
     ' Parte del *note ABI Stabile: 776.'


File: python.info,  Node: Examples<39>,  Prev: Slot Type typedefs,  Up: Type Object Structures

7.13.4.17 Examples
..................

The following are simple examples of Python type definitions.  They
include common usage you may encounter.  Some demonstrate tricky corner
cases.  For more examples, practical info, and a tutorial, see *note
Defining Extension Types; Tutorial: 4eae. and *note Defining Extension
Types; Assorted Topics: 4ec7.

A basic *note static type: 984.:

     typedef struct {
         PyObject_HEAD
         const char *data;
     } MyObject;

     static PyTypeObject MyObject_Type = {
         PyVarObject_HEAD_INIT(NULL, 0)
         .tp_name = "mymod.MyObject",
         .tp_basicsize = sizeof(MyObject),
         .tp_doc = PyDoc_STR("My objects"),
         .tp_new = myobj_new,
         .tp_dealloc = (destructor)myobj_dealloc,
         .tp_repr = (reprfunc)myobj_repr,
     };

You may also find older code (especially in the CPython code base) with
a more verbose initializer:

     static PyTypeObject MyObject_Type = {
         PyVarObject_HEAD_INIT(NULL, 0)
         "mymod.MyObject",               /* tp_name */
         sizeof(MyObject),               /* tp_basicsize */
         0,                              /* tp_itemsize */
         (destructor)myobj_dealloc,      /* tp_dealloc */
         0,                              /* tp_vectorcall_offset */
         0,                              /* tp_getattr */
         0,                              /* tp_setattr */
         0,                              /* tp_as_async */
         (reprfunc)myobj_repr,           /* tp_repr */
         0,                              /* tp_as_number */
         0,                              /* tp_as_sequence */
         0,                              /* tp_as_mapping */
         0,                              /* tp_hash */
         0,                              /* tp_call */
         0,                              /* tp_str */
         0,                              /* tp_getattro */
         0,                              /* tp_setattro */
         0,                              /* tp_as_buffer */
         0,                              /* tp_flags */
         PyDoc_STR("My objects"),        /* tp_doc */
         0,                              /* tp_traverse */
         0,                              /* tp_clear */
         0,                              /* tp_richcompare */
         0,                              /* tp_weaklistoffset */
         0,                              /* tp_iter */
         0,                              /* tp_iternext */
         0,                              /* tp_methods */
         0,                              /* tp_members */
         0,                              /* tp_getset */
         0,                              /* tp_base */
         0,                              /* tp_dict */
         0,                              /* tp_descr_get */
         0,                              /* tp_descr_set */
         0,                              /* tp_dictoffset */
         0,                              /* tp_init */
         0,                              /* tp_alloc */
         myobj_new,                      /* tp_new */
     };

A type that supports weakrefs, instance dicts, and hashing:

     typedef struct {
         PyObject_HEAD
         const char *data;
     } MyObject;

     static PyTypeObject MyObject_Type = {
         PyVarObject_HEAD_INIT(NULL, 0)
         .tp_name = "mymod.MyObject",
         .tp_basicsize = sizeof(MyObject),
         .tp_doc = PyDoc_STR("My objects"),
         .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE |
              Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_MANAGED_DICT |
              Py_TPFLAGS_MANAGED_WEAKREF,
         .tp_new = myobj_new,
         .tp_traverse = (traverseproc)myobj_traverse,
         .tp_clear = (inquiry)myobj_clear,
         .tp_alloc = PyType_GenericNew,
         .tp_dealloc = (destructor)myobj_dealloc,
         .tp_repr = (reprfunc)myobj_repr,
         .tp_hash = (hashfunc)myobj_hash,
         .tp_richcompare = PyBaseObject_Type.tp_richcompare,
     };

A str subclass that cannot be subclassed and cannot be called to create
instances (e.g.  uses a separate factory func) using *note
Py_TPFLAGS_DISALLOW_INSTANTIATION: 7a3. flag:

     typedef struct {
         PyUnicodeObject raw;
         char *extra;
     } MyStr;

     static PyTypeObject MyStr_Type = {
         PyVarObject_HEAD_INIT(NULL, 0)
         .tp_name = "mymod.MyStr",
         .tp_basicsize = sizeof(MyStr),
         .tp_base = NULL,  // set to &PyUnicode_Type in module init
         .tp_doc = PyDoc_STR("my custom str"),
         .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION,
         .tp_repr = (reprfunc)myobj_repr,
     };

The simplest *note static type: 984. with fixed-length instances:

     typedef struct {
         PyObject_HEAD
     } MyObject;

     static PyTypeObject MyObject_Type = {
         PyVarObject_HEAD_INIT(NULL, 0)
         .tp_name = "mymod.MyObject",
     };

The simplest *note static type: 984. with variable-length instances:

     typedef struct {
         PyObject_VAR_HEAD
         const char *data[1];
     } MyObject;

     static PyTypeObject MyObject_Type = {
         PyVarObject_HEAD_INIT(NULL, 0)
         .tp_name = "mymod.MyObject",
         .tp_basicsize = sizeof(MyObject) - sizeof(char *),
         .tp_itemsize = sizeof(char *),
     };


File: python.info,  Node: Supporting Cyclic Garbage Collection,  Prev: Type Object Structures,  Up: Object Implementation Support

7.13.5 Supporting Cyclic Garbage Collection
-------------------------------------------

Python’s support for detecting and collecting garbage which involves
circular references requires support from object types which are
«containers» for other objects which may also be containers.  Types
which do not store references to other objects, or which only store
references to atomic types (such as numbers or strings), do not need to
provide any explicit support for garbage collection.

To create a container type, the *note tp_flags: 1c59. field of the type
object must include the *note Py_TPFLAGS_HAVE_GC: 982. and provide an
implementation of the *note tp_traverse: 983. handler.  If instances of
the type are mutable, a *note tp_clear: 4ecb. implementation must also
be provided.

*note Py_TPFLAGS_HAVE_GC: 982.

     Objects with a type with this flag set must conform with the rules
     documented here.  For convenience these objects will be referred to
     as container objects.

Constructors for container types must conform to two rules:

  1. The memory for the object must be allocated using *note
     PyObject_GC_New: c9b. or *note PyObject_GC_NewVar: c9c.

  2. Once all the fields which may contain references to other
     containers are initialized, it must call *note PyObject_GC_Track():
     170b.

Similarly, the deallocator for the object must conform to a similar pair
of rules:

  1. Before fields which refer to other containers are invalidated,
     *note PyObject_GC_UnTrack(): 170c. must be called.

  2. The object’s memory must be deallocated using *note
     PyObject_GC_Del(): 170a.

          Avvertimento: If a type adds the Py_TPFLAGS_HAVE_GC, then it
          'must' implement at least a *note tp_traverse: 983. handler or
          explicitly use one from its subclass or subclasses.

          When calling *note PyType_Ready(): 981. or some of the APIs
          that indirectly call it like *note PyType_FromSpecWithBases():
          79f. or *note PyType_FromSpec(): 79e. the interpreter will
          automatically populate the *note tp_flags: 1c59, *note
          tp_traverse: 983. and *note tp_clear: 4ecb. fields if the type
          inherits from a class that implements the garbage collector
          protocol and the child class does 'not' include the *note
          Py_TPFLAGS_HAVE_GC: 982. flag.

 -- C Macro: PyObject_GC_New (TYPE, typeobj)

     Analogous to *note PyObject_New: b7e. but for container objects
     with the *note Py_TPFLAGS_HAVE_GC: 982. flag set.

     Do not call this directly to allocate memory for an object; call
     the type’s *note tp_alloc: 4eb9. slot instead.

     When populating a type’s *note tp_alloc: 4eb9. slot, *note
     PyType_GenericAlloc(): c63. is preferred over a custom function
     that simply calls this macro.

     Memory allocated by this macro must be freed with *note
     PyObject_GC_Del(): 170a. (usually called via the object’s *note
     tp_free: 4eb8. slot).

     Vedi anche
     ..........

        * *note PyObject_GC_Del(): 170a.

        * *note PyObject_New: b7e.

        * *note PyType_GenericAlloc(): c63.

        * *note tp_alloc: 4eb9.

 -- C Macro: PyObject_GC_NewVar (TYPE, typeobj, size)

     Analogous to *note PyObject_NewVar: b7f. but for container objects
     with the *note Py_TPFLAGS_HAVE_GC: 982. flag set.

     Do not call this directly to allocate memory for an object; call
     the type’s *note tp_alloc: 4eb9. slot instead.

     When populating a type’s *note tp_alloc: 4eb9. slot, *note
     PyType_GenericAlloc(): c63. is preferred over a custom function
     that simply calls this macro.

     Memory allocated by this macro must be freed with *note
     PyObject_GC_Del(): 170a. (usually called via the object’s *note
     tp_free: 4eb8. slot).

     Vedi anche
     ..........

        * *note PyObject_GC_Del(): 170a.

        * *note PyObject_NewVar: b7f.

        * *note PyType_GenericAlloc(): c63.

        * *note tp_alloc: 4eb9.

 -- C Funzione: *note PyObject: 5df.
          *PyUnstable_Object_GC_NewWithExtraData (PyTypeObject *type,
          size_t extra_size)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Analogous to *note PyObject_GC_New: c9b. but allocates 'extra_size'
     bytes at the end of the object (at offset *note tp_basicsize:
     b80.).  The allocated memory is initialized to zeros, except for
     the *note Python object header: 5df.

     The extra data will be deallocated with the object, but otherwise
     it is not managed by Python.

     Memory allocated by this function must be freed with *note
     PyObject_GC_Del(): 170a. (usually called via the object’s *note
     tp_free: 4eb8. slot).

          Avvertimento: The function is marked as unstable because the
          final mechanism for reserving extra data after an instance is
          not yet decided.  For allocating a variable number of fields,
          prefer using *note PyVarObject: 46be. and *note tp_itemsize:
          23a1. instead.

     Added in version 3.12.

 -- C Macro: PyObject_GC_Resize (TYPE, op, newsize)

     Resize an object allocated by *note PyObject_NewVar: b7f.  Returns
     the resized object of type ‘TYPE*’ (refers to any C type) or ‘NULL’
     on failure.

     'op' must be of type *note PyVarObject: 46be.* and must not be
     tracked by the collector yet.  'newsize' must be of type *note
     Py_ssize_t: c57.

 -- C Funzione: void PyObject_GC_Track (PyObject *op)
     ' Parte del *note ABI Stabile: 776.'  Adds the object 'op' to the
     set of container objects tracked by the collector.  The collector
     can run at unexpected times so objects must be valid while being
     tracked.  This should be called once all the fields followed by the
     *note tp_traverse: 983. handler become valid, usually near the end
     of the constructor.

 -- C Funzione: int PyObject_IS_GC (PyObject *obj)

     Returns non-zero if the object implements the garbage collector
     protocol, otherwise returns 0.

     The object cannot be tracked by the garbage collector if this
     function returns 0.

 -- C Funzione: int PyObject_GC_IsTracked (PyObject *op)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.9.'  Returns 1
     if the object type of 'op' implements the GC protocol and 'op' is
     being currently tracked by the garbage collector and 0 otherwise.

     This is analogous to the Python function *note gc.is_tracked():
     1515.

     Added in version 3.9.

 -- C Funzione: int PyObject_GC_IsFinalized (PyObject *op)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.9.'  Returns 1
     if the object type of 'op' implements the GC protocol and 'op' has
     been already finalized by the garbage collector and 0 otherwise.

     This is analogous to the Python function *note gc.is_finalized():
     afb.

     Added in version 3.9.

 -- C Funzione: void PyObject_GC_Del (void *op)
     ' Parte del *note ABI Stabile: 776.'  Releases memory allocated to
     an object using *note PyObject_GC_New: c9b. or *note
     PyObject_GC_NewVar: c9c.

     Do not call this directly to free an object’s memory; call the
     type’s *note tp_free: 4eb8. slot instead.

     Do not use this for memory allocated by *note PyObject_New: b7e,
     *note PyObject_NewVar: b7f, or related allocation functions; use
     *note PyObject_Free(): e61. instead.

     Vedi anche
     ..........

        * *note PyObject_Free(): e61. is the non-GC equivalent of this
          function.

        * *note PyObject_GC_New: c9b.

        * *note PyObject_GC_NewVar: c9c.

        * *note PyType_GenericAlloc(): c63.

        * *note tp_free: 4eb8.

 -- C Funzione: void PyObject_GC_UnTrack (void *op)
     ' Parte del *note ABI Stabile: 776.'  Remove the object 'op' from
     the set of container objects tracked by the collector.  Note that
     *note PyObject_GC_Track(): 170b. can be called again on this object
     to add it back to the set of tracked objects.  The deallocator
     (*note tp_dealloc: 4ea5. handler) should call this for the object
     before any of the fields used by the *note tp_traverse: 983.
     handler become invalid.

Cambiato nella versione 3.8: The ‘_PyObject_GC_TRACK()’ and
‘_PyObject_GC_UNTRACK()’ macros have been removed from the public C API.

The *note tp_traverse: 983. handler accepts a function parameter of this
type:

 -- C Tipo: typedef int (*visitproc)(*note PyObject: 5df. *object, void
          *arg)
     ' Parte del *note ABI Stabile: 776.'  Type of the visitor function
     passed to the *note tp_traverse: 983. handler.  The function should
     be called with an object to traverse as 'object' and the third
     parameter to the *note tp_traverse: 983. handler as 'arg'.  The
     Python core uses several visitor functions to implement cyclic
     garbage detection; it’s not expected that users will need to write
     their own visitor functions.

The *note tp_traverse: 983. handler must have the following type:

 -- C Tipo: typedef int (*traverseproc)(*note PyObject: 5df. *self,
          *note visitproc: 5194. visit, void *arg)
     ' Parte del *note ABI Stabile: 776.'  Traversal function for a
     container object.  Implementations must call the 'visit' function
     for each object directly contained by 'self', with the parameters
     to 'visit' being the contained object and the 'arg' value passed to
     the handler.  The 'visit' function must not be called with a ‘NULL’
     object argument.  If 'visit' returns a non-zero value that value
     should be returned immediately.

     The traversal function must not have any side effects.
     Implementations may not modify the reference counts of any Python
     objects nor create or destroy any Python objects.

To simplify writing *note tp_traverse: 983. handlers, a *note
Py_VISIT(): 4ec2. macro is provided.  In order to use this macro, the
*note tp_traverse: 983. implementation must name its arguments exactly
'visit' and 'arg':

 -- C Macro: Py_VISIT (o)

     If the *note PyObject: 5df.* 'o' is not ‘NULL’, call the 'visit'
     callback, with arguments 'o' and 'arg'.  If 'visit' returns a
     non-zero value, then return it.  Using this macro, *note
     tp_traverse: 983. handlers look like:

          static int
          my_traverse(Noddy *self, visitproc visit, void *arg)
          {
              Py_VISIT(self->foo);
              Py_VISIT(self->bar);
              return 0;
          }

The *note tp_clear: 4ecb. handler must be of the *note inquiry: 5183.
type, or ‘NULL’ if the object is immutable.

 -- C Tipo: typedef int (*inquiry)(*note PyObject: 5df. *self)
     ' Parte del *note ABI Stabile: 776.'  Drop references that may have
     created reference cycles.  Immutable objects do not have to define
     this method since they can never directly create reference cycles.
     Note that the object must still be valid after calling this method
     (don’t just call *note Py_DECREF(): 791. on a reference).  The
     collector will call this method if it detects that this object is
     involved in a reference cycle.

* Menu:

* Controlling the Garbage Collector State::
* Querying Garbage Collector State::


File: python.info,  Node: Controlling the Garbage Collector State,  Next: Querying Garbage Collector State,  Up: Supporting Cyclic Garbage Collection

7.13.5.1 Controlling the Garbage Collector State
................................................

The C-API provides the following functions for controlling garbage
collection runs.

 -- C Funzione: *note Py_ssize_t: c57. PyGC_Collect (void)
     ' Parte del *note ABI Stabile: 776.'  Perform a full garbage
     collection, if the garbage collector is enabled.  (Note that *note
     gc.collect(): 1b3. runs it unconditionally.)

     Returns the number of collected + unreachable objects which cannot
     be collected.  If the garbage collector is disabled or already
     collecting, returns ‘0’ immediately.  Errors during garbage
     collection are passed to *note sys.unraisablehook: 508.  This
     function does not raise exceptions.

 -- C Funzione: int PyGC_Enable (void)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Enable
     the garbage collector: similar to *note gc.enable(): 49f6.  Returns
     the previous state, 0 for disabled and 1 for enabled.

     Added in version 3.10.

 -- C Funzione: int PyGC_Disable (void)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Disable
     the garbage collector: similar to *note gc.disable(): 49f7.
     Returns the previous state, 0 for disabled and 1 for enabled.

     Added in version 3.10.

 -- C Funzione: int PyGC_IsEnabled (void)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.10.'  Query
     the state of the garbage collector: similar to *note
     gc.isenabled(): 49f8.  Returns the current state, 0 for disabled
     and 1 for enabled.

     Added in version 3.10.


File: python.info,  Node: Querying Garbage Collector State,  Prev: Controlling the Garbage Collector State,  Up: Supporting Cyclic Garbage Collection

7.13.5.2 Querying Garbage Collector State
.........................................

The C-API provides the following interface for querying information
about the garbage collector.

 -- C Funzione: void PyUnstable_GC_VisitObjects (gcvisitobjects_t
          callback, void *arg)

          Questa pagina API Instabile. Potrebbe cambiare senza preavviso nelle release minori. 'Questa pagina *note API Instabile: 76a. Potrebbe cambiare senza preavviso nelle release minori.': 
     Run supplied 'callback' on all live GC-capable objects.  'arg' is
     passed through to all invocations of 'callback'.

          Avvertimento: If new objects are (de)allocated by the callback
          it is undefined if they will be visited.

          Garbage collection is disabled during operation.  Explicitly
          running a collection in the callback may lead to undefined
          behaviour e.g.  visiting the same objects multiple times or
          not at all.

     Added in version 3.12.

 -- C Tipo: typedef int (*gcvisitobjects_t)(*note PyObject: 5df.
          *object, void *arg)

     Type of the visitor function to be passed to *note
     PyUnstable_GC_VisitObjects(): 5649.  'arg' is the same as the 'arg'
     passed to ‘PyUnstable_GC_VisitObjects’.  Return ‘1’ to continue
     iteration, return ‘0’ to stop iteration.  Other return values are
     reserved for now so behavior on returning anything else is
     undefined.

     Added in version 3.12.


File: python.info,  Node: API and ABI Versioning,  Next: Monitoring C API,  Prev: Object Implementation Support,  Up: Python/C API Reference Manual

7.14 API and ABI Versioning
===========================

* Menu:

* Build-time version constants::
* Run-time version::
* Bit-packing macros::


File: python.info,  Node: Build-time version constants,  Next: Run-time version,  Up: API and ABI Versioning

7.14.1 Build-time version constants
-----------------------------------

CPython exposes its version number in the following macros.  Note that
these correspond to the version code is 'built' with.  See *note
Py_Version: 381. for the version used at 'run time'.

See *note C API Stability: 776. for a discussion of API and ABI
stability across versions.

 -- C Macro: PY_MAJOR_VERSION

     The ‘3’ in ‘3.4.1a2’.

 -- C Macro: PY_MINOR_VERSION

     The ‘4’ in ‘3.4.1a2’.

 -- C Macro: PY_MICRO_VERSION

     The ‘1’ in ‘3.4.1a2’.

 -- C Macro: PY_RELEASE_LEVEL

     The ‘a’ in ‘3.4.1a2’.  This can be ‘0xA’ for alpha, ‘0xB’ for beta,
     ‘0xC’ for release candidate or ‘0xF’ for final.

 -- C Macro: PY_RELEASE_SERIAL

     The ‘2’ in ‘3.4.1a2’.  Zero for final releases.

 -- C Macro: PY_VERSION_HEX

     The Python version number encoded in a single integer.  See *note
     Py_PACK_FULL_VERSION(): 380. for the encoding details.

     Use this for numeric comparisons, for example, ‘#if PY_VERSION_HEX
     >= ...’.

These macros are defined in Include/patchlevel.h(1).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Include/patchlevel.h


File: python.info,  Node: Run-time version,  Next: Bit-packing macros,  Prev: Build-time version constants,  Up: API and ABI Versioning

7.14.2 Run-time version
-----------------------

 -- C Variabile: const unsigned long Py_Version
     ' Parte del *note ABI Stabile: 776. dalla versione 3.11.'  The
     Python runtime version number encoded in a single constant integer.
     See *note Py_PACK_FULL_VERSION(): 380. for the encoding details.
     This contains the Python version used at run time.

     Use this for numeric comparisons, for example, ‘if (Py_Version >=
     ...)’.

     Added in version 3.11.


File: python.info,  Node: Bit-packing macros,  Prev: Run-time version,  Up: API and ABI Versioning

7.14.3 Bit-packing macros
-------------------------

 -- C Funzione: uint32_t Py_PACK_FULL_VERSION (int major, int minor, int
          micro, int release_level, int release_serial)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'  Return
     the given version, encoded as a single 32-bit integer with the
     following structure:

     Argument               No.  of     Bit mask             Bit shift       Example values
                            bits                                             
                            
     -----------------------------------------------------------------------------------------------------------
                            
     ‘3.4.1a2’              ‘3.10.0’
                            
                                                                                               
     'major'                8           ‘0xFF000000’         24              ‘0x03’            ‘0x03’
                                                                                               
                                                                                               
     'minor'                8           ‘0x00FF0000’         16              ‘0x04’            ‘0x0A’
                                                                                               
                                                                                               
     'micro'                8           ‘0x0000FF00’         8               ‘0x01’            ‘0x00’
                                                                                               
                                                                                               
     'release_level'        4           ‘0x000000F0’         4               ‘0xA’             ‘0xF’
                                                                                               
                                                                                               
     'release_serial'       4           ‘0x0000000F’         0               ‘0x2’             ‘0x0’
                                                                                               

     For example:

     Version           ‘Py_PACK_FULL_VERSION’ arguments         Encoded version
                                                                
     ---------------------------------------------------------------------------------
                                                                
     ‘3.4.1a2’         ‘(3, 4, 1, 0xA, 2)’                      ‘0x030401a2’
                                                                
                                                                
     ‘3.10.0’          ‘(3, 10, 0, 0xF, 0)’                     ‘0x030a00f0’
                                                                

     Out-of range bits in the arguments are ignored.  That is, the macro
     can be defined as:

          #ifndef Py_PACK_FULL_VERSION
          #define Py_PACK_FULL_VERSION(X, Y, Z, LEVEL, SERIAL) ( \
             (((X) & 0xff) << 24) |                              \
             (((Y) & 0xff) << 16) |                              \
             (((Z) & 0xff) << 8) |                               \
             (((LEVEL) & 0xf) << 4) |                            \
             (((SERIAL) & 0xf) << 0))
          #endif

     ‘Py_PACK_FULL_VERSION’ is primarily a macro, intended for use in
     ‘#if’ directives, but it is also available as an exported function.

     Added in version 3.14.

 -- C Funzione: uint32_t Py_PACK_VERSION (int major, int minor)
     ' Parte del *note ABI Stabile: 776. dalla versione 3.14.'
     Equivalent to ‘Py_PACK_FULL_VERSION(major, minor, 0, 0, 0)’.  The
     result does not correspond to any Python release, but is useful in
     numeric comparisons.

     Added in version 3.14.


File: python.info,  Node: Monitoring C API,  Next: Generating Execution Events,  Prev: API and ABI Versioning,  Up: Python/C API Reference Manual

7.15 Monitoring C API
=====================

Added in version 3.13.

An extension may need to interact with the event monitoring system.
Subscribing to events and registering callbacks can be done via the
Python API exposed in *note sys.monitoring: e0.


File: python.info,  Node: Generating Execution Events,  Prev: Monitoring C API,  Up: Python/C API Reference Manual

7.16 Generating Execution Events
================================

The functions below make it possible for an extension to fire monitoring
events as it emulates the execution of Python code.  Each of these
functions accepts a ‘PyMonitoringState’ struct which contains concise
information about the activation state of events, as well as the event
arguments, which include a ‘PyObject*’ representing the code object, the
instruction offset and sometimes additional, event-specific arguments
(see *note sys.monitoring: e0. for details about the signatures of the
different event callbacks).  The ‘codelike’ argument should be an
instance of *note types.CodeType: 32f. or of a type that emulates it.

The VM disables tracing when firing an event, so there is no need for
user code to do that.

Monitoring functions should not be called with an exception set, except
those listed below as working with the current exception.

 -- C Tipo: type PyMonitoringState

     Representation of the state of an event type.  It is allocated by
     the user while its contents are maintained by the monitoring API
     functions described below.

All of the functions below return 0 on success and -1 (with an exception
set) on error.

See *note sys.monitoring: e0. for descriptions of the events.

 -- C Funzione: int PyMonitoring_FirePyStartEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset)

     Fire a ‘PY_START’ event.

 -- C Funzione: int PyMonitoring_FirePyResumeEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset)

     Fire a ‘PY_RESUME’ event.

 -- C Funzione: int PyMonitoring_FirePyReturnEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset, PyObject *retval)

     Fire a ‘PY_RETURN’ event.

 -- C Funzione: int PyMonitoring_FirePyYieldEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset, PyObject *retval)

     Fire a ‘PY_YIELD’ event.

 -- C Funzione: int PyMonitoring_FireCallEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset, PyObject
          *callable, PyObject *arg0)

     Fire a ‘CALL’ event.

 -- C Funzione: int PyMonitoring_FireLineEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset, int lineno)

     Fire a ‘LINE’ event.

 -- C Funzione: int PyMonitoring_FireJumpEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset, PyObject
          *target_offset)

     Fire a ‘JUMP’ event.

 -- C Funzione: int PyMonitoring_FireBranchLeftEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset, PyObject
          *target_offset)

     Fire a ‘BRANCH_LEFT’ event.

 -- C Funzione: int PyMonitoring_FireBranchRightEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset, PyObject
          *target_offset)

     Fire a ‘BRANCH_RIGHT’ event.

 -- C Funzione: int PyMonitoring_FireCReturnEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset, PyObject *retval)

     Fire a ‘C_RETURN’ event.

 -- C Funzione: int PyMonitoring_FirePyThrowEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset)

     Fire a ‘PY_THROW’ event with the current exception (as returned by
     *note PyErr_GetRaisedException(): 429.).

 -- C Funzione: int PyMonitoring_FireRaiseEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset)

     Fire a ‘RAISE’ event with the current exception (as returned by
     *note PyErr_GetRaisedException(): 429.).

 -- C Funzione: int PyMonitoring_FireCRaiseEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset)

     Fire a ‘C_RAISE’ event with the current exception (as returned by
     *note PyErr_GetRaisedException(): 429.).

 -- C Funzione: int PyMonitoring_FireReraiseEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset)

     Fire a ‘RERAISE’ event with the current exception (as returned by
     *note PyErr_GetRaisedException(): 429.).

 -- C Funzione: int PyMonitoring_FireExceptionHandledEvent
          (PyMonitoringState *state, PyObject *codelike, int32_t offset)

     Fire an ‘EXCEPTION_HANDLED’ event with the current exception (as
     returned by *note PyErr_GetRaisedException(): 429.).

 -- C Funzione: int PyMonitoring_FirePyUnwindEvent (PyMonitoringState
          *state, PyObject *codelike, int32_t offset)

     Fire a ‘PY_UNWIND’ event with the current exception (as returned by
     *note PyErr_GetRaisedException(): 429.).

 -- C Funzione: int PyMonitoring_FireStopIterationEvent
          (PyMonitoringState *state, PyObject *codelike, int32_t offset,
          PyObject *value)

     Fire a ‘STOP_ITERATION’ event.  If ‘value’ is an instance of *note
     StopIteration: df7, it is used.  Otherwise, a new *note
     StopIteration: df7. instance is created with ‘value’ as its
     argument.

* Menu:

* Managing the Monitoring State::


File: python.info,  Node: Managing the Monitoring State,  Up: Generating Execution Events

7.16.1 Managing the Monitoring State
------------------------------------

Monitoring states can be managed with the help of monitoring scopes.  A
scope would typically correspond to a Python function.

 -- C Funzione: int PyMonitoring_EnterScope (PyMonitoringState
          *state_array, uint64_t *version, const uint8_t *event_types,
          Py_ssize_t length)

     Enter a monitored scope.  ‘event_types’ is an array of the event
     IDs for events that may be fired from the scope.  For example, the
     ID of a ‘PY_START’ event is the value
     ‘PY_MONITORING_EVENT_PY_START’, which is numerically equal to the
     base-2 logarithm of ‘sys.monitoring.events.PY_START’.
     ‘state_array’ is an array with a monitoring state entry for each
     event in ‘event_types’, it is allocated by the user but populated
     by ‘PyMonitoring_EnterScope()’ with information about the
     activation state of the event.  The size of ‘event_types’ (and
     hence also of ‘state_array’) is given in ‘length’.

     The ‘version’ argument is a pointer to a value which should be
     allocated by the user together with ‘state_array’ and initialized
     to 0, and then set only by ‘PyMonitoring_EnterScope()’ itself.  It
     allows this function to determine whether event states have changed
     since the previous call, and to return quickly if they have not.

     The scopes referred to here are lexical scopes: a function, class
     or method.  ‘PyMonitoring_EnterScope()’ should be called whenever
     the lexical scope is entered.  Scopes can be reentered, reusing the
     same 'state_array' and 'version', in situations like when emulating
     a recursive Python function.  When a code-like’s execution is
     paused, such as when emulating a generator, the scope needs to be
     exited and re-entered.

     The macros for 'event_types' are:

     Macro                                                  Event
                                                            
     -------------------------------------------------------------------------------------------------
                                                            
      -- C Macro: PY_MONITORING_EVENT_BRANCH_LEFT           *note BRANCH_LEFT: 295.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_BRANCH_RIGHT          *note BRANCH_RIGHT: 296.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_CALL                  *note CALL: 19a5.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_C_RAISE               *note C_RAISE: 4922.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_C_RETURN              *note C_RETURN: 4923.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_EXCEPTION_HANDLED     *note EXCEPTION_HANDLED: 4924.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_INSTRUCTION           *note INSTRUCTION: 4925.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_JUMP                  *note JUMP: 4926.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_LINE                  *note LINE: 4927.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_PY_RESUME             *note PY_RESUME: 4928.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_PY_RETURN             *note PY_RETURN: 4929.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_PY_START              *note PY_START: 492a.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_PY_THROW              *note PY_THROW: 183d.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_PY_UNWIND             *note PY_UNWIND: 492b.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_PY_YIELD              *note PY_YIELD: 492c.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_RAISE                 *note RAISE: 195c.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_RERAISE               *note RERAISE: 492e.
                                                            
                                                            
      -- C Macro: PY_MONITORING_EVENT_STOP_ITERATION        *note STOP_ITERATION: 492d.
                                                            

 -- C Funzione: int PyMonitoring_ExitScope (void)

     Exit the last scope that was entered with
     ‘PyMonitoring_EnterScope()’.

 -- C Funzione: int PY_MONITORING_IS_INSTRUMENTED_EVENT (uint8_t ev)

     Return true if the event corresponding to the event ID 'ev' is a
     *note local event: 4932.

     Added in version 3.13.

     Deprecato dalla versione 3.14: This function is *note soft
     deprecated: 23d.


File: python.info,  Node: Installing Python Modules,  Next: Python HOWTOs,  Prev: Python/C API Reference Manual,  Up: Top

8 Installing Python Modules
***************************


Email: <distutils-sig@python.org>

As a popular open source development project, Python has an active
supporting community of contributors and users that also make their
software available for other Python developers to use under open source
license terms.

This allows Python users to share and collaborate effectively,
benefiting from the solutions others have already created to common (and
sometimes even rare!)  problems, as well as potentially contributing
their own solutions to the common pool.

This guide covers the installation part of the process.  For a guide to
creating and sharing your own Python projects, refer to the Python
packaging user guide(1).

     Nota: For corporate and other institutional users, be aware that
     many organisations have their own policies around using and
     contributing to open source software.  Please take such policies
     into account when making use of the distribution and installation
     tools provided with Python.

* Menu:

* Key terms::
* Basic usage: Basic usage<2>.
* How do I …?::
* Common installation issues::

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/tutorials/packaging-projects/


File: python.info,  Node: Key terms,  Next: Basic usage<2>,  Up: Installing Python Modules

8.1 Key terms
=============

   * ‘pip’ is the preferred installer program.  Starting with Python
     3.4, it is included by default with the Python binary installers.

   * A 'virtual environment' is a semi-isolated Python environment that
     allows packages to be installed for use by a particular
     application, rather than being installed system wide.

   * ‘venv’ is the standard tool for creating virtual environments, and
     has been part of Python since Python 3.3.  Starting with Python
     3.4, it defaults to installing ‘pip’ into all created virtual
     environments.

   * ‘virtualenv’ is a third party alternative (and predecessor) to
     ‘venv’.  It allows virtual environments to be used on versions of
     Python prior to 3.4, which either don’t provide ‘venv’ at all, or
     aren’t able to automatically install ‘pip’ into created
     environments.

   * The Python Package Index(1) is a public repository of open source
     licensed packages made available for use by other Python users.

   * the Python Packaging Authority(2) is the group of developers and
     documentation authors responsible for the maintenance and evolution
     of the standard packaging tools and the associated metadata and
     file format standards.  They maintain a variety of tools,
     documentation, and issue trackers on GitHub(3).

   * ‘distutils’ is the original build and distribution system first
     added to the Python standard library in 1998.  While direct use of
     ‘distutils’ is being phased out, it still laid the foundation for
     the current packaging and distribution infrastructure, and it not
     only remains part of the standard library, but its name lives on in
     other ways (such as the name of the mailing list used to coordinate
     Python packaging standards development).

Cambiato nella versione 3.5: The use of ‘venv’ is now recommended for
creating virtual environments.

Vedi anche
..........

Python Packaging User Guide: Creating and using virtual environments(4)

   ---------- Footnotes ----------

   (1) https://pypi.org

   (2) https://www.pypa.io/

   (3) https://github.com/pypa

   (4) 
https://packaging.python.org/installing/#creating-virtual-environments


File: python.info,  Node: Basic usage<2>,  Next: How do I …?,  Prev: Key terms,  Up: Installing Python Modules

8.2 Basic usage
===============

The standard packaging tools are all designed to be used from the
command line.

The following command will install the latest version of a module and
its dependencies from the Python Package Index:

     python -m pip install SomePackage

     Nota: For POSIX users (including macOS and Linux users), the
     examples in this guide assume the use of a *note virtual
     environment: 20d7.

     For Windows users, the examples in this guide assume that the
     option to adjust the system PATH environment variable was selected
     when installing Python.

It’s also possible to specify an exact or minimum version directly on
the command line.  When using comparator operators such as ‘>’, ‘<’ or
some other special character which get interpreted by shell, the package
name and the version should be enclosed within double quotes:

     python -m pip install SomePackage==1.0.4    # specific version
     python -m pip install "SomePackage>=1.0.4"  # minimum version

Normally, if a suitable module is already installed, attempting to
install it again will have no effect.  Upgrading existing modules must
be requested explicitly:

     python -m pip install --upgrade SomePackage

More information and resources regarding ‘pip’ and its capabilities can
be found in the Python Packaging User Guide(1).

Creation of virtual environments is done through the *note venv: 117.
module.  Installing packages into an active virtual environment uses the
commands shown above.

Vedi anche
..........

Python Packaging User Guide: Installing Python Distribution Packages(2)

   ---------- Footnotes ----------

   (1) https://packaging.python.org

   (2) https://packaging.python.org/installing/


File: python.info,  Node: How do I …?,  Next: Common installation issues,  Prev: Basic usage<2>,  Up: Installing Python Modules

8.3 How do I …?
===============

These are quick answers or links for some common tasks.

* Menu:

* … install pip in versions of Python prior to Python 3.4?: … install pip in versions of Python prior to Python 3 4?.
* … install packages just for the current user?::
* … install scientific Python packages?::
* … work with multiple versions of Python installed in parallel?::


File: python.info,  Node: … install pip in versions of Python prior to Python 3 4?,  Next: … install packages just for the current user?,  Up: How do I …?

8.3.1 … install ‘pip’ in versions of Python prior to Python 3.4?
----------------------------------------------------------------

Python only started bundling ‘pip’ with Python 3.4.  For earlier
versions, ‘pip’ needs to be «bootstrapped» as described in the Python
Packaging User Guide.

Vedi anche
..........

Python Packaging User Guide: Requirements for Installing Packages(1)

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/installing/#requirements-for-installing-packages


File: python.info,  Node: … install packages just for the current user?,  Next: … install scientific Python packages?,  Prev: … install pip in versions of Python prior to Python 3 4?,  Up: How do I …?

8.3.2 … install packages just for the current user?
---------------------------------------------------

Passing the ‘--user’ option to ‘python -m pip install’ will install a
package just for the current user, rather than for all users of the
system.


File: python.info,  Node: … install scientific Python packages?,  Next: … work with multiple versions of Python installed in parallel?,  Prev: … install packages just for the current user?,  Up: How do I …?

8.3.3 … install scientific Python packages?
-------------------------------------------

A number of scientific Python packages have complex binary dependencies,
and aren’t currently easy to install using ‘pip’ directly.  At this
point in time, it will often be easier for users to install these
packages by other means(1) rather than attempting to install them with
‘pip’.

Vedi anche
..........

Python Packaging User Guide: Installing Scientific Packages(2)

   ---------- Footnotes ----------

   (1) https://packaging.python.org/science/

   (2) https://packaging.python.org/science/


File: python.info,  Node: … work with multiple versions of Python installed in parallel?,  Prev: … install scientific Python packages?,  Up: How do I …?

8.3.4 … work with multiple versions of Python installed in parallel?
--------------------------------------------------------------------

On Linux, macOS, and other POSIX systems, use the versioned Python
commands in combination with the ‘-m’ switch to run the appropriate copy
of ‘pip’:

     python2   -m pip install SomePackage  # default Python 2
     python2.7 -m pip install SomePackage  # specifically Python 2.7
     python3   -m pip install SomePackage  # default Python 3
     python3.4 -m pip install SomePackage  # specifically Python 3.4

Appropriately versioned ‘pip’ commands may also be available.

On Windows, use the ‘py’ Python launcher in combination with the ‘-m’
switch:

     py -2   -m pip install SomePackage  # default Python 2
     py -2.7 -m pip install SomePackage  # specifically Python 2.7
     py -3   -m pip install SomePackage  # default Python 3
     py -3.4 -m pip install SomePackage  # specifically Python 3.4


File: python.info,  Node: Common installation issues,  Prev: How do I …?,  Up: Installing Python Modules

8.4 Common installation issues
==============================

* Menu:

* Installing into the system Python on Linux::
* Pip not installed::
* Installing binary extensions::


File: python.info,  Node: Installing into the system Python on Linux,  Next: Pip not installed,  Up: Common installation issues

8.4.1 Installing into the system Python on Linux
------------------------------------------------

On Linux systems, a Python installation will typically be included as
part of the distribution.  Installing into this Python installation
requires root access to the system, and may interfere with the operation
of the system package manager and other components of the system if a
component is unexpectedly upgraded using ‘pip’.

On such systems, it is often better to use a virtual environment or a
per-user installation when installing packages with ‘pip’.


File: python.info,  Node: Pip not installed,  Next: Installing binary extensions,  Prev: Installing into the system Python on Linux,  Up: Common installation issues

8.4.2 Pip not installed
-----------------------

It is possible that ‘pip’ does not get installed by default.  One
potential fix is:

     python -m ensurepip --default-pip

There are also additional resources for installing pip.(1)

   ---------- Footnotes ----------

   (1) 
https://packaging.python.org/en/latest/tutorials/installing-packages/#ensure-pip-setuptools-and-wheel-are-up-to-date


File: python.info,  Node: Installing binary extensions,  Prev: Pip not installed,  Up: Common installation issues

8.4.3 Installing binary extensions
----------------------------------

Python has typically relied heavily on source based distribution, with
end users being expected to compile extension modules from source as
part of the installation process.

With the introduction of support for the binary ‘wheel’ format, and the
ability to publish wheels for at least Windows and macOS through the
Python Package Index, this problem is expected to diminish over time, as
users are more regularly able to install pre-built extensions rather
than needing to build them themselves.

Some of the solutions for installing scientific software(1) that are not
yet available as pre-built ‘wheel’ files may also help with obtaining
other binary extensions without needing to build them locally.

Vedi anche
..........

Python Packaging User Guide: Binary Extensions(2)

   ---------- Footnotes ----------

   (1) https://packaging.python.org/science/

   (2) https://packaging.python.org/extensions/


File: python.info,  Node: Python HOWTOs,  Next: Python Frequently Asked Questions,  Prev: Installing Python Modules,  Up: Top

9 Python HOWTOs
***************

Python HOWTOs are documents that cover a specific topic in-depth.
Modeled on the Linux Documentation Project’s HOWTO collection, this
collection is an effort to foster documentation that’s more detailed
than the Python Library Reference.

* Menu:

* A Conceptual Overview of asyncio::
* Porting Extension Modules to Python 3::
* Curses Programming with Python::
* Descriptor Guide::
* Debugging C API extensions and CPython Internals with GDB::
* Enum HOWTO::
* Functional Programming HOWTO::
* Logging HOWTO::
* Logging Cookbook::
* Regular Expression HOWTO::
* Socket Programming HOWTO::
* Sorting Techniques::
* Unicode HOWTO::
* HOWTO Fetch Internet Resources Using The urllib Package::
* An introduction to the ipaddress module::
* Instrumenting CPython with DTrace and SystemTap::
* Python support for the Linux perf profiler::
* Annotations Best Practices::
* Isolating Extension Modules::
* timer file descriptor HOWTO::
* The Python 2.3 Method Resolution Order: The Python 2 3 Method Resolution Order.
* Python support for free threading::
* C API Extension Support for Free Threading::
* Remote debugging attachment protocol::
* Permission requirements::
* Locating the PyRuntime structure::
* Reading _Py_DebugOffsets::
* Locating the interpreter and thread state::
* Writing control information::
* Summary::


File: python.info,  Node: A Conceptual Overview of asyncio,  Next: Porting Extension Modules to Python 3,  Up: Python HOWTOs

9.1 A Conceptual Overview of ‘asyncio’
======================================

This *note HOWTO: 567d. article seeks to help you build a sturdy mental
model of how *note asyncio: b. fundamentally works, helping you
understand the how and why behind the recommended patterns.

You might be curious about some key ‘asyncio’ concepts.  By the end of
this article, you’ll be able to comfortably answer these questions:

   - What’s happening behind the scenes when an object is awaited?

   - How does ‘asyncio’ differentiate between a task which doesn’t need
     CPU time (such as a network request or file read) as opposed to a
     task that does (such as computing n-factorial)?

   - How to write an asynchronous variant of an operation, such as an
     async sleep or database request.

Vedi anche
..........

   * The guide(1) that inspired this HOWTO article, by Alexander Nordin.

   * This in-depth YouTube tutorial series(2) on ‘asyncio’ created by
     Python core team member, Łukasz Langa.

   * 500 Lines or Less: A Web Crawler With asyncio Coroutines(3) by A.
     Jesse Jiryu Davis and Guido van Rossum.

* Menu:

* A conceptual overview part 1; the high-level: A conceptual overview part 1 the high-level.
* A conceptual overview part 2; the nuts and bolts: A conceptual overview part 2 the nuts and bolts.

   ---------- Footnotes ----------

   (1) 
https://github.com/anordin95/a-conceptual-overview-of-asyncio/tree/main

   (2) 
https://www.youtube.com/watch?v=Xbl7XjFYsN4&list=PLhNSoGM2ik6SIkVGXWBwerucXjgP1rHmB

   (3) 
https://aosabook.org/en/500L/a-web-crawler-with-asyncio-coroutines.html


File: python.info,  Node: A conceptual overview part 1 the high-level,  Next: A conceptual overview part 2 the nuts and bolts,  Up: A Conceptual Overview of asyncio

9.1.1 A conceptual overview part 1: the high-level
--------------------------------------------------

In part 1, we’ll cover the main, high-level building blocks of
‘asyncio’: the event loop, coroutine functions, coroutine objects,
tasks, and ‘await’.

* Menu:

* Event Loop: Event Loop<2>.
* Asynchronous functions and coroutines::
* Tasks: Tasks<2>.
* await::


File: python.info,  Node: Event Loop<2>,  Next: Asynchronous functions and coroutines,  Up: A conceptual overview part 1 the high-level

9.1.1.1 Event Loop
..................

Everything in ‘asyncio’ happens relative to the event loop.  It’s the
star of the show.  It’s like an orchestra conductor.  It’s behind the
scenes managing resources.  Some power is explicitly granted to it, but
a lot of its ability to get things done comes from the respect and
cooperation of its worker bees.

In more technical terms, the event loop contains a collection of jobs to
be run.  Some jobs are added directly by you, and some indirectly by
‘asyncio’.  The event loop takes a job from its backlog of work and
invokes it (or «gives it control»), similar to calling a function, and
then that job runs.  Once it pauses or completes, it returns control to
the event loop.  The event loop will then select another job from its
pool and invoke it.  You can 'roughly' think of the collection of jobs
as a queue: jobs are added and then processed one at a time, generally
(but not always) in order.  This process repeats indefinitely, with the
event loop cycling endlessly onwards.  If there are no more jobs pending
execution, the event loop is smart enough to rest and avoid needlessly
wasting CPU cycles, and will come back when there’s more work to be
done.

Effective execution relies on jobs sharing well and cooperating; a
greedy job could hog control and leave the other jobs to starve,
rendering the overall event loop approach rather useless.

     import asyncio

     # This creates an event loop and indefinitely cycles through
     # its collection of jobs.
     event_loop = asyncio.new_event_loop()
     event_loop.run_forever()


File: python.info,  Node: Asynchronous functions and coroutines,  Next: Tasks<2>,  Prev: Event Loop<2>,  Up: A conceptual overview part 1 the high-level

9.1.1.2 Asynchronous functions and coroutines
.............................................

This is a basic, boring Python function:

     def hello_printer():
         print(
             "Hi, I am a lowly, simple printer, though I have all I "
             "need in life -- \nfresh paper and my dearly beloved octopus "
             "partner in crime."
         )

Calling a regular function invokes its logic or body:

     >>> hello_printer()
     Hi, I am a lowly, simple printer, though I have all I need in life --
     fresh paper and my dearly beloved octopus partner in crime.

The *note async def: 7ee, as opposed to just a plain ‘def’, makes this
an asynchronous function (or «coroutine function»).  Calling it creates
and returns a *note coroutine: 379e. object.

     async def loudmouth_penguin(magic_number: int):
         print(
          "I am a super special talking penguin. Far cooler than that printer. "
          f"By the way, my lucky number is: {magic_number}."
         )

Calling the async function, ‘loudmouth_penguin’, does not execute the
print statement; instead, it creates a coroutine object:

     >>> loudmouth_penguin(magic_number=3)
     <coroutine object loudmouth_penguin at 0x104ed2740>

The terms «coroutine function» and «coroutine object» are often
conflated as coroutine.  That can be confusing!  In this article,
coroutine specifically refers to a coroutine object, or more precisely,
an instance of *note types.CoroutineType: 108b. (native coroutine).
Note that coroutines can also exist as instances of *note
collections.abc.Coroutine: fdf. – a distinction that matters for type
checking.

A coroutine represents the function’s body or logic.  A coroutine has to
be explicitly started; again, merely creating the coroutine does not
start it.  Notably, the coroutine can be paused and resumed at various
points within the function’s body.  That pausing and resuming ability is
what allows for asynchronous behavior!

Coroutines and coroutine functions were built by leveraging the
functionality of *note generators: ddb. and *note generator functions:
1263.  Recall, a generator function is a function that *note yield:
bc4.s, like this one:

     def get_random_number():
         # This would be a bad random number generator!
         print("Hi")
         yield 1
         print("Hello")
         yield 7
         print("Howdy")
         yield 4
         ...

Similar to a coroutine function, calling a generator function does not
run it.  Instead, it creates a generator object:

     >>> get_random_number()
     <generator object get_random_number at 0x1048671c0>

You can proceed to the next ‘yield’ of a generator by using the built-in
function *note next(): 9da.  In other words, the generator runs, then
pauses.  For example:

     >>> generator = get_random_number()
     >>> next(generator)
     Hi
     1
     >>> next(generator)
     Hello
     7


File: python.info,  Node: Tasks<2>,  Next: await,  Prev: Asynchronous functions and coroutines,  Up: A conceptual overview part 1 the high-level

9.1.1.3 Tasks
.............

Roughly speaking, *note tasks: 37d0. are coroutines (not coroutine
functions) tied to an event loop.  A task also maintains a list of
callback functions whose importance will become clear in a moment when
we discuss *note await: 18d.  The recommended way to create tasks is via
*note asyncio.create_task(): 1c9.

Creating a task automatically schedules it for execution (by adding a
callback to run it in the event loop’s to-do list, that is, collection
of jobs).

‘asyncio’ automatically associates tasks with the event loop for you.
This automatic association was purposely designed into ‘asyncio’ for the
sake of simplicity.  Without it, you’d have to keep track of the event
loop object and pass it to any coroutine function that wants to create
tasks, adding redundant clutter to your code.

     coroutine = loudmouth_penguin(magic_number=5)
     # This creates a Task object and schedules its execution via the event loop.
     task = asyncio.create_task(coroutine)

Earlier, we manually created the event loop and set it to run forever.
In practice, it’s recommended to use (and common to see) *note
asyncio.run(): 2f3, which takes care of managing the event loop and
ensuring the provided coroutine finishes before advancing.  For example,
many async programs follow this setup:

     import asyncio

     async def main():
         # Perform all sorts of wacky, wild asynchronous things...
         ...

     if __name__ == "__main__":
         asyncio.run(main())
         # The program will not reach the following print statement until the
         # coroutine main() finishes.
         print("coroutine main() is done!")

It’s important to be aware that the task itself is not added to the
event loop, only a callback to the task is.  This matters if the task
object you created is garbage collected before it’s called by the event
loop.  For example, consider this program:

     async def hello():
         print("hello!")

     async def main():
         asyncio.create_task(hello())
         # Other asynchronous instructions which run for a while
         # and cede control to the event loop...
         ...

     asyncio.run(main())

Because there’s no reference to the task object created on line 5, it
'might' be garbage collected before the event loop invokes it.  Later
instructions in the coroutine ‘main()’ hand control back to the event
loop so it can invoke other jobs.  When the event loop eventually tries
to run the task, it might fail and discover the task object does not
exist!  This can also happen even if a coroutine keeps a reference to a
task but completes before that task finishes.  When the coroutine exits,
local variables go out of scope and may be subject to garbage
collection.  In practice, ‘asyncio’ and Python’s garbage collector work
pretty hard to ensure this sort of thing doesn’t happen.  But that’s no
reason to be reckless!


File: python.info,  Node: await,  Prev: Tasks<2>,  Up: A conceptual overview part 1 the high-level

9.1.1.4 await
.............

*note await: 18d. is a Python keyword that’s commonly used in one of two
different ways:

     await task
     await coroutine

In a crucial way, the behavior of ‘await’ depends on the type of object
being awaited.

Awaiting a task will cede control from the current task or coroutine to
the event loop.  In the process of relinquishing control, a few
important things happen.  We’ll use the following code example to
illustrate:

     async def plant_a_tree():
         dig_the_hole_task = asyncio.create_task(dig_the_hole())
         await dig_the_hole_task

         # Other instructions associated with planting a tree.
         ...

In this example, imagine the event loop has passed control to the start
of the coroutine ‘plant_a_tree()’.  As seen above, the coroutine creates
a task and then awaits it.  The ‘await dig_the_hole_task’ instruction
adds a callback (which will resume ‘plant_a_tree()’) to the
‘dig_the_hole_task’ object’s list of callbacks.  And then, the
instruction cedes control to the event loop.  Some time later, the event
loop will pass control to ‘dig_the_hole_task’ and the task will finish
whatever it needs to do.  Once the task finishes, it will add its
various callbacks to the event loop, in this case, a call to resume
‘plant_a_tree()’.

Generally speaking, when the awaited task finishes
(‘dig_the_hole_task’), the original task or coroutine (‘plant_a_tree()’)
is added back to the event loop’s to-do list to be resumed.

This is a basic, yet reliable mental model.  In practice, the control
handoffs are slightly more complex, but not by much.  In part 2, we’ll
walk through the details that make this possible.

'Unlike tasks, awaiting a coroutine does not hand control back to the
event loop!'  Wrapping a coroutine in a task first, then awaiting that
would cede control.  The behavior of ‘await coroutine’ is effectively
the same as invoking a regular, synchronous Python function.  Consider
this program:

     import asyncio

     async def coro_a():
        print("I am coro_a(). Hi!")

     async def coro_b():
        print("I am coro_b(). I sure hope no one hogs the event loop...")

     async def main():
        task_b = asyncio.create_task(coro_b())
        num_repeats = 3
        for _ in range(num_repeats):
           await coro_a()
        await task_b

     asyncio.run(main())

The first statement in the coroutine ‘main()’ creates ‘task_b’ and
schedules it for execution via the event loop.  Then, ‘coro_a()’ is
repeatedly awaited.  Control never cedes to the event loop, which is why
we see the output of all three ‘coro_a()’ invocations before
‘coro_b()’”s output:

     I am coro_a(). Hi!
     I am coro_a(). Hi!
     I am coro_a(). Hi!
     I am coro_b(). I sure hope no one hogs the event loop...

If we change ‘await coro_a()’ to ‘await asyncio.create_task(coro_a())’,
the behavior changes.  The coroutine ‘main()’ cedes control to the event
loop with that statement.  The event loop then proceeds through its
backlog of work, calling ‘task_b’ and then the task which wraps
‘coro_a()’ before resuming the coroutine ‘main()’.

     I am coro_b(). I sure hope no one hogs the event loop...
     I am coro_a(). Hi!
     I am coro_a(). Hi!
     I am coro_a(). Hi!

This behavior of ‘await coroutine’ can trip a lot of people up!  That
example highlights how using only ‘await coroutine’ could
unintentionally hog control from other tasks and effectively stall the
event loop.  *note asyncio.run(): 2f3. can help you detect such
occurrences via the ‘debug=True’ flag, which enables *note debug mode:
2123.  Among other things, it will log any coroutines that monopolize
execution for 100ms or longer.

The design intentionally trades off some conceptual clarity around usage
of ‘await’ for improved performance.  Each time a task is awaited,
control needs to be passed all the way up the call stack to the event
loop.  That might sound minor, but in a large program with many ‘await’
statements and a deep call stack, that overhead can add up to a
meaningful performance drag.


File: python.info,  Node: A conceptual overview part 2 the nuts and bolts,  Prev: A conceptual overview part 1 the high-level,  Up: A Conceptual Overview of asyncio

9.1.2 A conceptual overview part 2: the nuts and bolts
------------------------------------------------------

Part 2 goes into detail on the mechanisms ‘asyncio’ uses to manage
control flow.  This is where the magic happens.  You’ll come away from
this section knowing what ‘await’ does behind the scenes and how to make
your own asynchronous operators.

* Menu:

* The inner workings of coroutines::
* Futures: Futures<2>.
* A homemade asyncio.sleep: A homemade asyncio sleep.


File: python.info,  Node: The inner workings of coroutines,  Next: Futures<2>,  Up: A conceptual overview part 2 the nuts and bolts

9.1.2.1 The inner workings of coroutines
........................................

‘asyncio’ leverages four components to pass around control.

*note coroutine.send(arg): 23fd. is the method used to start or resume a
coroutine.  If the coroutine was paused and is now being resumed, the
argument ‘arg’ will be sent in as the return value of the ‘yield’
statement which originally paused it.  If the coroutine is being used
for the first time (as opposed to being resumed), ‘arg’ must be ‘None’.

     class Rock:
         def __await__(self):
             value_sent_in = yield 7
             print(f"Rock.__await__ resuming with value: {value_sent_in}.")
             return value_sent_in

     async def main():
         print("Beginning coroutine main().")
         rock = Rock()
         print("Awaiting rock...")
         value_from_rock = await rock
         print(f"Coroutine received value: {value_from_rock} from rock.")
         return 23

     coroutine = main()
     intermediate_result = coroutine.send(None)
     print(f"Coroutine paused and returned intermediate value: {intermediate_result}.")

     print(f"Resuming coroutine and sending in value: 42.")
     try:
         coroutine.send(42)
     except StopIteration as e:
         returned_value = e.value
     print(f"Coroutine main() finished and provided value: {returned_value}.")

*note yield: 2473, as usual, pauses execution and returns control to the
caller.  In the example above, the ‘yield’, on line 3, is called by ‘...
= await rock’ on line 11.  More broadly speaking, ‘await’ calls the
*note __await__(): f77. method of the given object.  ‘await’ also does
one more very special thing: it propagates (or «passes along») any
‘yield’s it receives up the call chain.  In this case, that’s back to
‘... = coroutine.send(None)’ on line 16.

The coroutine is resumed via the ‘coroutine.send(42)’ call on line 21.
The coroutine picks back up from where it ‘yield’ed (or paused) on line
3 and executes the remaining statements in its body.  When a coroutine
finishes, it raises a *note StopIteration: df7. exception with the
return value attached in the *note value: 23fa. attribute.

That snippet produces this output:

     Beginning coroutine main().
     Awaiting rock...
     Coroutine paused and returned intermediate value: 7.
     Resuming coroutine and sending in value: 42.
     Rock.__await__ resuming with value: 42.
     Coroutine received value: 42 from rock.
     Coroutine main() finished and provided value: 23.

It’s worth pausing for a moment here and making sure you followed the
various ways that control flow and values were passed.  A lot of
important ideas were covered and it’s worth ensuring your understanding
is firm.

The only way to yield (or effectively cede control) from a coroutine is
to ‘await’ an object that ‘yield’s in its ‘__await__’ method.  That
might sound odd to you.  You might be thinking:

     1.  What about a ‘yield’ directly within the coroutine function?
     The coroutine function becomes an *note async generator function:
     2477, a different beast entirely.

     2.  What about a *note yield from: 2473. within the coroutine
     function to a (plain) generator?  That causes the error:
     ‘SyntaxError: yield from not allowed in a coroutine.’ This was
     intentionally designed for the sake of simplicity – mandating only
     one way of using coroutines.  Initially ‘yield’ was barred as well,
     but was re-accepted to allow for async generators.  Despite that,
     ‘yield from’ and ‘await’ effectively do the same thing.


File: python.info,  Node: Futures<2>,  Next: A homemade asyncio sleep,  Prev: The inner workings of coroutines,  Up: A conceptual overview part 2 the nuts and bolts

9.1.2.2 Futures
...............

A *note future: 38ab. is an object meant to represent a computation’s
status and result.  The term is a nod to the idea of something still to
come or not yet happened, and the object is a way to keep an eye on that
something.

A future has a few important attributes.  One is its state, which can be
either «pending», «cancelled», or «done».  Another is its result, which
is set when the state transitions to done.  Unlike a coroutine, a future
does not represent the actual computation to be done; instead, it
represents the status and result of that computation, kind of like a
status light (red, yellow, or green) or indicator.

*note asyncio.Task: 1c7. subclasses *note asyncio.Future: dc8. in order
to gain these various capabilities.  The prior section said tasks store
a list of callbacks, which wasn’t entirely accurate.  It’s actually the
‘Future’ class that implements this logic, which ‘Task’ inherits.

Futures may also be used directly (not via tasks).  Tasks mark
themselves as done when their coroutine is complete.  Futures are much
more versatile and will be marked as done when you say so.  In this way,
they’re the flexible interface for you to make your own conditions for
waiting and resuming.


File: python.info,  Node: A homemade asyncio sleep,  Prev: Futures<2>,  Up: A conceptual overview part 2 the nuts and bolts

9.1.2.3 A homemade asyncio.sleep
................................

We’ll go through an example of how you could leverage a future to create
your own variant of asynchronous sleep (‘async_sleep’) which mimics
*note asyncio.sleep(): c66.

This snippet registers a few tasks with the event loop and then awaits
the task created by ‘asyncio.create_task’, which wraps the
‘async_sleep(3)’ coroutine.  We want that task to finish only after
three seconds have elapsed, but without preventing other tasks from
running.

     async def other_work():
         print("I like work. Work work.")

     async def main():
         # Add a few other tasks to the event loop, so there's something
         # to do while asynchronously sleeping.
         work_tasks = [
             asyncio.create_task(other_work()),
             asyncio.create_task(other_work()),
             asyncio.create_task(other_work())
         ]
         print(
             "Beginning asynchronous sleep at time: "
             f"{datetime.datetime.now().strftime("%H:%M:%S")}."
         )
         await asyncio.create_task(async_sleep(3))
         print(
             "Done asynchronous sleep at time: "
             f"{datetime.datetime.now().strftime("%H:%M:%S")}."
         )
         # asyncio.gather effectively awaits each task in the collection.
         await asyncio.gather(*work_tasks)

Below, we use a future to enable custom control over when that task will
be marked as done.  If *note future.set_result(): 37d3. (the method
responsible for marking that future as done) is never called, then this
task will never finish.  We’ve also enlisted the help of another task,
which we’ll see in a moment, that will monitor how much time has elapsed
and, accordingly, call ‘future.set_result()’.

     async def async_sleep(seconds: float):
         future = asyncio.Future()
         time_to_wake = time.time() + seconds
         # Add the watcher-task to the event loop.
         watcher_task = asyncio.create_task(_sleep_watcher(future, time_to_wake))
         # Block until the future is marked as done.
         await future

Below, we use a rather bare ‘YieldToEventLoop()’ object to ‘yield’ from
its ‘__await__’ method, ceding control to the event loop.  This is
effectively the same as calling ‘asyncio.sleep(0)’, but this approach
offers more clarity, not to mention it’s somewhat cheating to use
‘asyncio.sleep’ when showcasing how to implement it!

As usual, the event loop cycles through its tasks, giving them control
and receiving control back when they pause or finish.  The
‘watcher_task’, which runs the coroutine ‘_sleep_watcher(...)’, will be
invoked once per full cycle of the event loop.  On each resumption,
it’ll check the time and if not enough has elapsed, then it’ll pause
once again and hand control back to the event loop.  Once enough time
has elapsed, ‘_sleep_watcher(...)’ marks the future as done and
completes by exiting its infinite ‘while’ loop.  Given this helper task
is only invoked once per cycle of the event loop, you’d be correct to
note that this asynchronous sleep will sleep 'at least' three seconds,
rather than exactly three seconds.  Note this is also true of
‘asyncio.sleep’.

     class YieldToEventLoop:
         def __await__(self):
             yield

     async def _sleep_watcher(future, time_to_wake):
         while True:
             if time.time() >= time_to_wake:
                 # This marks the future as done.
                 future.set_result(None)
                 break
             else:
                 await YieldToEventLoop()

Here is the full program’s output:

     $ python custom-async-sleep.py
     Beginning asynchronous sleep at time: 14:52:22.
     I like work. Work work.
     I like work. Work work.
     I like work. Work work.
     Done asynchronous sleep at time: 14:52:25.

You might feel this implementation of asynchronous sleep was
unnecessarily convoluted.  And, well, it was.  The example was meant to
showcase the versatility of futures with a simple example that could be
mimicked for more complex needs.  For reference, you could implement it
without futures, like so:

     async def simpler_async_sleep(seconds):
         time_to_wake = time.time() + seconds
         while True:
             if time.time() >= time_to_wake:
                 return
             else:
                 await YieldToEventLoop()

But that’s all for now.  Hopefully you’re ready to more confidently dive
into some async programming or check out advanced topics in the *note
rest of the documentation: b.


File: python.info,  Node: Porting Extension Modules to Python 3,  Next: Curses Programming with Python,  Prev: A Conceptual Overview of asyncio,  Up: Python HOWTOs

9.2 Porting Extension Modules to Python 3
=========================================

We recommend the following resources for porting extension modules to
Python 3:

   * The Migrating C extensions(1) chapter from 'Supporting Python 3: An
     in-depth guide', a book on moving from Python 2 to Python 3 in
     general, guides the reader through porting an extension module.

   * The Porting guide(2) from the 'py3c' project provides opinionated
     suggestions with supporting code.

   * *note Recommended third party tools: 4e77. offer abstractions over
     the Python’s C API. Extensions generally need to be re-written to
     use one of them, but the library then handles differences between
     various Python versions and implementations.

   ---------- Footnotes ----------

   (1) http://python3porting.com/cextensions.html

   (2) https://py3c.readthedocs.io/en/latest/guide.html


File: python.info,  Node: Curses Programming with Python,  Next: Descriptor Guide,  Prev: Porting Extension Modules to Python 3,  Up: Python HOWTOs

9.3 Curses Programming with Python
==================================


Author: A.M. Kuchling, Eric S. Raymond


Release: 2.04

Abstract
........

This document describes how to use the *note curses: 2f. extension
module to control text-mode displays.

* Menu:

* What is curses?::
* Starting and ending a curses application::
* Windows and Pads::
* Displaying Text::
* User Input::
* For More Information::


File: python.info,  Node: What is curses?,  Next: Starting and ending a curses application,  Up: Curses Programming with Python

9.3.1 What is curses?
---------------------

The curses library supplies a terminal-independent screen-painting and
keyboard-handling facility for text-based terminals; such terminals
include VT100s, the Linux console, and the simulated terminal provided
by various programs.  Display terminals support various control codes to
perform common operations such as moving the cursor, scrolling the
screen, and erasing areas.  Different terminals use widely differing
codes, and often have their own minor quirks.

In a world of graphical displays, one might ask «why bother»?  It’s true
that character-cell display terminals are an obsolete technology, but
there are niches in which being able to do fancy things with them are
still valuable.  One niche is on small-footprint or embedded Unixes that
don’t run an X server.  Another is tools such as OS installers and
kernel configurators that may have to run before any graphical support
is available.

The curses library provides fairly basic functionality, providing the
programmer with an abstraction of a display containing multiple
non-overlapping windows of text.  The contents of a window can be
changed in various ways—adding text, erasing it, changing its
appearance—and the curses library will figure out what control codes
need to be sent to the terminal to produce the right output.  curses
doesn’t provide many user-interface concepts such as buttons,
checkboxes, or dialogs; if you need such features, consider a user
interface library such as Urwid(1).

The curses library was originally written for BSD Unix; the later System
V versions of Unix from AT&T added many enhancements and new functions.
BSD curses is no longer maintained, having been replaced by ncurses,
which is an open-source implementation of the AT&T interface.  If you’re
using an open-source Unix such as Linux or FreeBSD, your system almost
certainly uses ncurses.  Since most current commercial Unix versions are
based on System V code, all the functions described here will probably
be available.  The older versions of curses carried by some proprietary
Unixes may not support everything, though.

The Windows version of Python doesn’t include the *note curses: 2f.
module.  A ported version called UniCurses(2) is available.

* Menu:

* The Python curses module::

   ---------- Footnotes ----------

   (1) https://pypi.org/project/Urwid/

   (2) https://pypi.org/project/UniCurses/


File: python.info,  Node: The Python curses module,  Up: What is curses?

9.3.1.1 The Python curses module
................................

The Python module is a fairly simple wrapper over the C functions
provided by curses; if you’re already familiar with curses programming
in C, it’s really easy to transfer that knowledge to Python.  The
biggest difference is that the Python interface makes things simpler by
merging different C functions such as ‘addstr()’, ‘mvaddstr()’, and
‘mvwaddstr()’ into a single *note addstr(): 345b. method.  You’ll see
this covered in more detail later.

This HOWTO is an introduction to writing text-mode programs with curses
and Python.  It doesn’t attempt to be a complete guide to the curses
API; for that, see the Python library guide’s section on ncurses, and
the C manual pages for ncurses.  It will, however, give you the basic
ideas.


File: python.info,  Node: Starting and ending a curses application,  Next: Windows and Pads,  Prev: What is curses?,  Up: Curses Programming with Python

9.3.2 Starting and ending a curses application
----------------------------------------------

Before doing anything, curses must be initialized.  This is done by
calling the *note initscr(): 18f7. function, which will determine the
terminal type, send any required setup codes to the terminal, and create
various internal data structures.  If successful, ‘initscr()’ returns a
window object representing the entire screen; this is usually called
‘stdscr’ after the name of the corresponding C variable.

     import curses
     stdscr = curses.initscr()

Usually curses applications turn off automatic echoing of keys to the
screen, in order to be able to read keys and only display them under
certain circumstances.  This requires calling the *note noecho(): 3482.
function.

     curses.noecho()

Applications will also commonly need to react to keys instantly, without
requiring the Enter key to be pressed; this is called cbreak mode, as
opposed to the usual buffered input mode.

     curses.cbreak()

Terminals usually return special keys, such as the cursor keys or
navigation keys such as Page Up and Home, as a multibyte escape
sequence.  While you could write your application to expect such
sequences and process them accordingly, curses can do it for you,
returning a special value such as *note curses.KEY_LEFT: 34f9.  To get
curses to do the job, you’ll have to enable keypad mode.

     stdscr.keypad(True)

Terminating a curses application is much easier than starting one.
You’ll need to call:

     curses.nocbreak()
     stdscr.keypad(False)
     curses.echo()

to reverse the curses-friendly terminal settings.  Then call the *note
endwin(): 345e. function to restore the terminal to its original
operating mode.

     curses.endwin()

A common problem when debugging a curses application is to get your
terminal messed up when the application dies without restoring the
terminal to its previous state.  In Python this commonly happens when
your code is buggy and raises an uncaught exception.  Keys are no longer
echoed to the screen when you type them, for example, which makes using
the shell difficult.

In Python you can avoid these complications and make debugging much
easier by importing the *note curses.wrapper(): c75. function and using
it like this:

     from curses import wrapper

     def main(stdscr):
         # Clear screen
         stdscr.clear()

         # This raises ZeroDivisionError when i == 10.
         for i in range(0, 11):
             v = i-10
             stdscr.addstr(i, 0, '10 divided by {} is {}'.format(v, 10/v))

             stdscr.refresh()
             stdscr.getkey()

     wrapper(main)

The *note wrapper(): c75. function takes a callable object and does the
initializations described above, also initializing colors if color
support is present.  ‘wrapper()’ then runs your provided callable.  Once
the callable returns, ‘wrapper()’ will restore the original state of the
terminal.  The callable is called inside a *note try: 8f9.…*note except:
1ab. that catches exceptions, restores the state of the terminal, and
then re-raises the exception.  Therefore your terminal won’t be left in
a funny state on exception and you’ll be able to read the exception’s
message and traceback.


File: python.info,  Node: Windows and Pads,  Next: Displaying Text,  Prev: Starting and ending a curses application,  Up: Curses Programming with Python

9.3.3 Windows and Pads
----------------------

Windows are the basic abstraction in curses.  A window object represents
a rectangular area of the screen, and supports methods to display text,
erase it, allow the user to input strings, and so forth.

The ‘stdscr’ object returned by the *note initscr(): 18f7. function is a
window object that covers the entire screen.  Many programs may need
only this single window, but you might wish to divide the screen into
smaller windows, in order to redraw or clear them separately.  The *note
newwin(): 3480. function creates a new window of a given size, returning
the new window object.

     begin_x = 20; begin_y = 7
     height = 5; width = 40
     win = curses.newwin(height, width, begin_y, begin_x)

Note that the coordinate system used in curses is unusual.  Coordinates
are always passed in the order 'y,x', and the top-left corner of a
window is coordinate (0,0).  This breaks the normal convention for
handling coordinates where the 'x' coordinate comes first.  This is an
unfortunate difference from most other computer applications, but it’s
been part of curses since it was first written, and it’s too late to
change things now.

Your application can determine the size of the screen by using the *note
curses.LINES: fee. and *note curses.COLS: fef. variables to obtain the
'y' and 'x' sizes.  Legal coordinates will then extend from ‘(0,0)’ to
‘(curses.LINES - 1, curses.COLS - 1)’.

When you call a method to display or erase text, the effect doesn’t
immediately show up on the display.  Instead you must call the *note
refresh(): 345c. method of window objects to update the screen.

This is because curses was originally written with slow 300-baud
terminal connections in mind; with these terminals, minimizing the time
required to redraw the screen was very important.  Instead curses
accumulates changes to the screen and displays them in the most
efficient manner when you call ‘refresh()’.  For example, if your
program displays some text in a window and then clears the window,
there’s no need to send the original text because they’re never visible.

In practice, explicitly telling curses to redraw a window doesn’t really
complicate programming with curses much.  Most programs go into a flurry
of activity, and then pause waiting for a keypress or some other action
on the part of the user.  All you have to do is to be sure that the
screen has been redrawn before pausing to wait for user input, by first
calling ‘stdscr.refresh()’ or the ‘refresh()’ method of some other
relevant window.

A pad is a special case of a window; it can be larger than the actual
display screen, and only a portion of the pad displayed at a time.
Creating a pad requires the pad’s height and width, while refreshing a
pad requires giving the coordinates of the on-screen area where a
subsection of the pad will be displayed.

     pad = curses.newpad(100, 100)
     # These loops fill the pad with letters; addch() is
     # explained in the next section
     for y in range(0, 99):
         for x in range(0, 99):
             pad.addch(y,x, ord('a') + (x*x+y*y) % 26)

     # Displays a section of the pad in the middle of the screen.
     # (0,0) : coordinate of upper-left corner of pad area to display.
     # (5,5) : coordinate of upper-left corner of window area to be filled
     #         with pad content.
     # (20, 75) : coordinate of lower-right corner of window area to be
     #          : filled with pad content.
     pad.refresh( 0,0, 5,5, 20,75)

The ‘refresh()’ call displays a section of the pad in the rectangle
extending from coordinate (5,5) to coordinate (20,75) on the screen; the
upper left corner of the displayed section is coordinate (0,0) on the
pad.  Beyond that difference, pads are exactly like ordinary windows and
support the same methods.

If you have multiple windows and pads on screen there is a more
efficient way to update the screen and prevent annoying screen flicker
as each part of the screen gets updated.  ‘refresh()’ actually does two
things:

  1. Calls the *note noutrefresh(): 345a. method of each window to
     update an underlying data structure representing the desired state
     of the screen.

  2. Calls the function *note doupdate(): 3459. function to change the
     physical screen to match the desired state recorded in the data
     structure.

Instead you can call ‘noutrefresh()’ on a number of windows to update
the data structure, and then call ‘doupdate()’ to update the screen.


File: python.info,  Node: Displaying Text,  Next: User Input,  Prev: Windows and Pads,  Up: Curses Programming with Python

9.3.4 Displaying Text
---------------------

From a C programmer’s point of view, curses may sometimes look like a
twisty maze of functions, all subtly different.  For example, ‘addstr()’
displays a string at the current cursor location in the ‘stdscr’ window,
while ‘mvaddstr()’ moves to a given y,x coordinate first before
displaying the string.  ‘waddstr()’ is just like ‘addstr()’, but allows
specifying a window to use instead of using ‘stdscr’ by default.
‘mvwaddstr()’ allows specifying both a window and a coordinate.

Fortunately the Python interface hides all these details.  ‘stdscr’ is a
window object like any other, and methods such as *note addstr(): 345b.
accept multiple argument forms.  Usually there are four different forms.

Form                                  Description
                                      
------------------------------------------------------------------------------------------
                                      
'str' or 'ch'                         Display the string 'str' or character 'ch' at the
                                      current position
                                      
                                      
'str' or 'ch', 'attr'                 Display the string 'str' or character 'ch', using
                                      attribute 'attr' at the current position
                                      
                                      
'y', 'x', 'str' or 'ch'               Move to position 'y,x' within the window, and
                                      display 'str' or 'ch'
                                      
                                      
'y', 'x', 'str' or 'ch', 'attr'       Move to position 'y,x' within the window, and
                                      display 'str' or 'ch', using attribute 'attr'
                                      

Attributes allow displaying text in highlighted forms such as boldface,
underline, reverse code, or in color.  They’ll be explained in more
detail in the next subsection.

The *note addstr(): 345b. method takes a Python string or bytestring as
the value to be displayed.  The contents of bytestrings are sent to the
terminal as-is.  Strings are encoded to bytes using the value of the
window’s *note encoding: 129e. attribute; this defaults to the default
system encoding as returned by *note locale.getencoding(): 329.

The *note addch(): 349b. methods take a character, which can be either a
string of length 1, a bytestring of length 1, or an integer.

Constants are provided for extension characters; these constants are
integers greater than 255.  For example, *note ACS_PLMINUS: 3566. is a
+/- symbol, and *note ACS_ULCORNER: 34a5. is the upper left corner of a
box (handy for drawing borders).  You can also use the appropriate
Unicode character.

Windows remember where the cursor was left after the last operation, so
if you leave out the 'y,x' coordinates, the string or character will be
displayed wherever the last operation left off.  You can also move the
cursor with the ‘move(y,x)’ method.  Because some terminals always
display a flashing cursor, you may want to ensure that the cursor is
positioned in some location where it won’t be distracting; it can be
confusing to have the cursor blinking at some apparently random
location.

If your application doesn’t need a blinking cursor at all, you can call
‘curs_set(False)’ to make it invisible.  For compatibility with older
curses versions, there’s a ‘leaveok(bool)’ function that’s a synonym for
*note curs_set(): 3453.  When 'bool' is true, the curses library will
attempt to suppress the flashing cursor, and you won’t need to worry
about leaving it in odd locations.

* Menu:

* Attributes and Color::


File: python.info,  Node: Attributes and Color,  Up: Displaying Text

9.3.4.1 Attributes and Color
............................

Characters can be displayed in different ways.  Status lines in a
text-based application are commonly shown in reverse video, or a text
viewer may need to highlight certain words.  curses supports this by
allowing you to specify an attribute for each cell on the screen.

An attribute is an integer, each bit representing a different attribute.
You can try to display text with multiple attribute bits set, but curses
doesn’t guarantee that all the possible combinations are available, or
that they’re all visually distinct.  That depends on the ability of the
terminal being used, so it’s safest to stick to the most commonly
available attributes, listed here.

Attribute                  Description
                           
----------------------------------------------------------------------
                           
*note A_BLINK: 34e5.       Blinking text
                           
                           
*note A_BOLD: 34e6.        Extra bright or bold text
                           
                           
*note A_DIM: 34e7.         Half bright text
                           
                           
*note A_REVERSE: 3451.     Reverse-video text
                           
                           
*note A_STANDOUT: 3450.    The best highlighting mode available
                           
                           
*note A_UNDERLINE: 34eb.   Underlined text
                           

So, to display a reverse-video status line on the top line of the
screen, you could code:

     stdscr.addstr(0, 0, "Current mode: Typing mode",
                   curses.A_REVERSE)
     stdscr.refresh()

The curses library also supports color on those terminals that provide
it.  The most common such terminal is probably the Linux console,
followed by color xterms.

To use color, you must call the *note start_color(): 348c. function soon
after calling *note initscr(): 18f7, to initialize the default color set
(the *note curses.wrapper(): c75. function does this automatically).
Once that’s done, the *note has_colors(): 3471. function returns TRUE if
the terminal in use can actually display color.  (Note: curses uses the
American spelling “color”, instead of the Canadian/British spelling
“colour”.  If you’re used to the British spelling, you’ll have to resign
yourself to misspelling it for the sake of these functions.)

The curses library maintains a finite number of color pairs, containing
a foreground (or text) color and a background color.  You can get the
attribute value corresponding to a color pair with the *note
color_pair(): 344f. function; this can be bitwise-OR’ed with other
attributes such as *note A_REVERSE: 3451, but again, such combinations
are not guaranteed to work on all terminals.

An example, which displays a line of text using color pair 1:

     stdscr.addstr("Pretty text", curses.color_pair(1))
     stdscr.refresh()

As I said before, a color pair consists of a foreground and background
color.  The ‘init_pair(n, f, b)’ function changes the definition of
color pair 'n', to foreground color f and background color b.  Color
pair 0 is hard-wired to white on black, and cannot be changed.

Colors are numbered, and *note start_color(): 348c. initializes 8 basic
colors when it activates color mode.  They are: 0:black, 1:red, 2:green,
3:yellow, 4:blue, 5:magenta, 6:cyan, and 7:white.  The *note curses: 2f.
module defines named constants for each of these colors: *note
curses.COLOR_BLACK: 3578, *note curses.COLOR_RED: 357d, and so forth.

Let’s put all this together.  To change color 1 to red text on a white
background, you would call:

     curses.init_pair(1, curses.COLOR_RED, curses.COLOR_WHITE)

When you change a color pair, any text already displayed using that
color pair will change to the new colors.  You can also display new text
in this color with:

     stdscr.addstr(0,0, "RED ALERT!", curses.color_pair(1))

Very fancy terminals can change the definitions of the actual colors to
a given RGB value.  This lets you change color 1, which is usually red,
to purple or blue or any other color you like.  Unfortunately, the Linux
console doesn’t support this, so I’m unable to try it out, and can’t
provide any examples.  You can check if your terminal can do this by
calling *note can_change_color(): 344c, which returns ‘True’ if the
capability is there.  If you’re lucky enough to have such a talented
terminal, consult your system’s man pages for more information.


File: python.info,  Node: User Input,  Next: For More Information,  Prev: Displaying Text,  Up: Curses Programming with Python

9.3.5 User Input
----------------

The C curses library offers only very simple input mechanisms.  Python’s
*note curses: 2f. module adds a basic text-input widget.  (Other
libraries such as Urwid(1) have more extensive collections of widgets.)

There are two methods for getting input from a window:

   * *note getch(): 180d. refreshes the screen and then waits for the
     user to hit a key, displaying the key if *note echo(): 345d. has
     been called earlier.  You can optionally specify a coordinate to
     which the cursor should be moved before pausing.

   * *note getkey(): 34b9. does the same thing but converts the integer
     to a string.  Individual characters are returned as 1-character
     strings, and special keys such as function keys return longer
     strings containing a key name such as ‘KEY_UP’ or ‘^G’.

It’s possible to not wait for the user using the *note nodelay(): 34cd.
window method.  After ‘nodelay(True)’, ‘getch()’ and ‘getkey()’ for the
window become non-blocking.  To signal that no input is ready, ‘getch()’
returns ‘curses.ERR’ (a value of -1) and ‘getkey()’ raises an exception.
There’s also a *note halfdelay(): 3475. function, which can be used to
(in effect) set a timer on each ‘getch()’; if no input becomes available
within a specified delay (measured in tenths of a second), curses raises
an exception.

The ‘getch()’ method returns an integer; if it’s between 0 and 255, it
represents the ASCII code of the key pressed.  Values greater than 255
are special keys such as Page Up, Home, or the cursor keys.  You can
compare the value returned to constants such as *note curses.KEY_PPAGE:
350a, *note curses.KEY_HOME: 34fb, or *note curses.KEY_LEFT: 34f9.  The
main loop of your program may look something like this:

     while True:
         c = stdscr.getch()
         if c == ord('p'):
             PrintDocument()
         elif c == ord('q'):
             break  # Exit the while loop
         elif c == curses.KEY_HOME:
             x = y = 0

The *note curses.ascii: 30. module supplies ASCII class membership
functions that take either integer or 1-character string arguments;
these may be useful in writing more readable tests for such loops.  It
also supplies conversion functions that take either integer or
1-character-string arguments and return the same type.  For example,
*note curses.ascii.ctrl(): 35c0. returns the control character
corresponding to its argument.

There’s also a method to retrieve an entire string, *note getstr():
1826.  It isn’t used very often, because its functionality is quite
limited; the only editing keys available are the backspace key and the
Enter key, which terminates the string.  It can optionally be limited to
a fixed number of characters.

     curses.echo()            # Enable echoing of characters

     # Get a 15-character string, with the cursor on the top line
     s = stdscr.getstr(0,0, 15)

The *note curses.textpad: 32. module supplies a text box that supports
an Emacs-like set of keybindings.  Various methods of the *note Textbox:
3581. class support editing with input validation and gathering the edit
results either with or without trailing spaces.  Here’s an example:

     import curses
     from curses.textpad import Textbox, rectangle

     def main(stdscr):
         stdscr.addstr(0, 0, "Enter IM message: (hit Ctrl-G to send)")

         editwin = curses.newwin(5,30, 2,1)
         rectangle(stdscr, 1,0, 1+5+1, 1+30+1)
         stdscr.refresh()

         box = Textbox(editwin)

         # Let the user edit until Ctrl-G is struck.
         box.edit()

         # Get resulting contents
         message = box.gather()

See the library documentation on *note curses.textpad: 32. for more
details.

   ---------- Footnotes ----------

   (1) https://pypi.org/project/Urwid/


File: python.info,  Node: For More Information,  Prev: User Input,  Up: Curses Programming with Python

9.3.6 For More Information
--------------------------

This HOWTO doesn’t cover some advanced topics, such as reading the
contents of the screen or capturing mouse events from an xterm instance,
but the Python library page for the *note curses: 2f. module is now
reasonably complete.  You should browse it next.

If you’re in doubt about the detailed behavior of the curses functions,
consult the manual pages for your curses implementation, whether it’s
ncurses or a proprietary Unix vendor’s.  The manual pages will document
any quirks, and provide complete lists of all the functions, attributes,
and *note ACS_*: 3552. characters available to you.

Because the curses API is so large, some functions aren’t supported in
the Python interface.  Often this isn’t because they’re difficult to
implement, but because no one has needed them yet.  Also, Python doesn’t
yet support the menu library associated with ncurses.  Patches adding
support for these would be welcome; see the Python Developer's Guide(1)
to learn more about submitting patches to Python.

   * Writing Programs with NCURSES(2): a lengthy tutorial for C
     programmers.

   * The ncurses man page(3)

   * The ncurses FAQ(4)

   * "Use curses...  don't swear"(5): video of a PyCon 2013 talk on
     controlling terminals using curses or Urwid.

   * "Console Applications with Urwid"(6): video of a PyCon CA 2012 talk
     demonstrating some applications written using Urwid.

   ---------- Footnotes ----------

   (1) https://devguide.python.org/

   (2) https://invisible-island.net/ncurses/ncurses-intro.html

   (3) https://linux.die.net/man/3/ncurses

   (4) https://invisible-island.net/ncurses/ncurses.faq.html

   (5) https://www.youtube.com/watch?v=eN1eZtjLEnU

   (6) https://pyvideo.org/video/1568/console-applications-with-urwid


File: python.info,  Node: Descriptor Guide,  Next: Debugging C API extensions and CPython Internals with GDB,  Prev: Curses Programming with Python,  Up: Python HOWTOs

9.4 Descriptor Guide
====================


Author: Raymond Hettinger


Contact: <python at rcn dot com>

*note Descriptors: 1869. let objects customize attribute lookup,
storage, and deletion.

This guide has four major sections:

  1. The «primer» gives a basic overview, moving gently from simple
     examples, adding one feature at a time.  Start here if you’re new
     to descriptors.

  2. The second section shows a complete, practical descriptor example.
     If you already know the basics, start there.

  3. The third section provides a more technical tutorial that goes into
     the detailed mechanics of how descriptors work.  Most people don’t
     need this level of detail.

  4. The last section has pure Python equivalents for built-in
     descriptors that are written in C. Read this if you’re curious
     about how functions turn into bound methods or about the
     implementation of common tools like *note classmethod(): 48f, *note
     staticmethod(): 453, *note property(): 4b4, and *note __slots__:
     7f8.

* Menu:

* Primer::
* Complete Practical Example::
* Technical Tutorial::
* Pure Python Equivalents::


File: python.info,  Node: Primer,  Next: Complete Practical Example,  Up: Descriptor Guide

9.4.1 Primer
------------

In this primer, we start with the most basic possible example and then
we’ll add new capabilities one by one.

* Menu:

* Simple example; A descriptor that returns a constant: Simple example A descriptor that returns a constant.
* Dynamic lookups::
* Managed attributes::
* Customized names::
* Closing thoughts::


File: python.info,  Node: Simple example A descriptor that returns a constant,  Next: Dynamic lookups,  Up: Primer

9.4.1.1 Simple example: A descriptor that returns a constant
............................................................

The ‘Ten’ class is a descriptor whose *note __get__(): 16ef. method
always returns the constant ‘10’:

     class Ten:
         def __get__(self, obj, objtype=None):
             return 10

To use the descriptor, it must be stored as a class variable in another
class:

     class A:
         x = 5                       # Regular class attribute
         y = Ten()                   # Descriptor instance

An interactive session shows the difference between normal attribute
lookup and descriptor lookup:

     >>> a = A()                     # Make an instance of class A
     >>> a.x                         # Normal attribute lookup
     5
     >>> a.y                         # Descriptor lookup
     10

In the ‘a.x’ attribute lookup, the dot operator finds ‘'x': 5’ in the
class dictionary.  In the ‘a.y’ lookup, the dot operator finds a
descriptor instance, recognized by its ‘__get__’ method.  Calling that
method returns ‘10’.

Note that the value ‘10’ is not stored in either the class dictionary or
the instance dictionary.  Instead, the value ‘10’ is computed on demand.

This example shows how a simple descriptor works, but it isn’t very
useful.  For retrieving constants, normal attribute lookup would be
better.

In the next section, we’ll create something more useful, a dynamic
lookup.


File: python.info,  Node: Dynamic lookups,  Next: Managed attributes,  Prev: Simple example A descriptor that returns a constant,  Up: Primer

9.4.1.2 Dynamic lookups
.......................

Interesting descriptors typically run computations instead of returning
constants:

     import os

     class DirectorySize:

         def __get__(self, obj, objtype=None):
             return len(os.listdir(obj.dirname))

     class Directory:

         size = DirectorySize()              # Descriptor instance

         def __init__(self, dirname):
             self.dirname = dirname          # Regular instance attribute

An interactive session shows that the lookup is dynamic — it computes
different, updated answers each time:

     >>> s = Directory('songs')
     >>> g = Directory('games')
     >>> s.size                              # The songs directory has twenty files
     20
     >>> g.size                              # The games directory has three files
     3
     >>> os.remove('games/chess')            # Delete a game
     >>> g.size                              # File count is automatically updated
     2

Besides showing how descriptors can run computations, this example also
reveals the purpose of the parameters to *note __get__(): 16ef.  The
'self' parameter is 'size', an instance of 'DirectorySize'.  The 'obj'
parameter is either 'g' or 's', an instance of 'Directory'.  It is the
'obj' parameter that lets the *note __get__(): 16ef. method learn the
target directory.  The 'objtype' parameter is the class 'Directory'.


File: python.info,  Node: Managed attributes,  Next: Customized names,  Prev: Dynamic lookups,  Up: Primer

9.4.1.3 Managed attributes
..........................

A popular use for descriptors is managing access to instance data.  The
descriptor is assigned to a public attribute in the class dictionary
while the actual data is stored as a private attribute in the instance
dictionary.  The descriptor’s *note __get__(): 16ef. and *note
__set__(): 239b. methods are triggered when the public attribute is
accessed.

In the following example, 'age' is the public attribute and '_age' is
the private attribute.  When the public attribute is accessed, the
descriptor logs the lookup or update:

     import logging

     logging.basicConfig(level=logging.INFO)

     class LoggedAgeAccess:

         def __get__(self, obj, objtype=None):
             value = obj._age
             logging.info('Accessing %r giving %r', 'age', value)
             return value

         def __set__(self, obj, value):
             logging.info('Updating %r to %r', 'age', value)
             obj._age = value

     class Person:

         age = LoggedAgeAccess()             # Descriptor instance

         def __init__(self, name, age):
             self.name = name                # Regular instance attribute
             self.age = age                  # Calls __set__()

         def birthday(self):
             self.age += 1                   # Calls both __get__() and __set__()

An interactive session shows that all access to the managed attribute
'age' is logged, but that the regular attribute 'name' is not logged:

     >>> mary = Person('Mary M', 30)         # The initial age update is logged
     INFO:root:Updating 'age' to 30
     >>> dave = Person('David D', 40)
     INFO:root:Updating 'age' to 40

     >>> vars(mary)                          # The actual data is in a private attribute
     {'name': 'Mary M', '_age': 30}
     >>> vars(dave)
     {'name': 'David D', '_age': 40}

     >>> mary.age                            # Access the data and log the lookup
     INFO:root:Accessing 'age' giving 30
     30
     >>> mary.birthday()                     # Updates are logged as well
     INFO:root:Accessing 'age' giving 30
     INFO:root:Updating 'age' to 31

     >>> dave.name                           # Regular attribute lookup isn't logged
     'David D'
     >>> dave.age                            # Only the managed attribute is logged
     INFO:root:Accessing 'age' giving 40
     40

One major issue with this example is that the private name '_age' is
hardwired in the 'LoggedAgeAccess' class.  That means that each instance
can only have one logged attribute and that its name is unchangeable.
In the next example, we’ll fix that problem.


File: python.info,  Node: Customized names,  Next: Closing thoughts,  Prev: Managed attributes,  Up: Primer

9.4.1.4 Customized names
........................

When a class uses descriptors, it can inform each descriptor about which
variable name was used.

In this example, the ‘Person’ class has two descriptor instances, 'name'
and 'age'.  When the ‘Person’ class is defined, it makes a callback to
*note __set_name__(): e4a. in 'LoggedAccess' so that the field names can
be recorded, giving each descriptor its own 'public_name' and
'private_name':

     import logging

     logging.basicConfig(level=logging.INFO)

     class LoggedAccess:

         def __set_name__(self, owner, name):
             self.public_name = name
             self.private_name = '_' + name

         def __get__(self, obj, objtype=None):
             value = getattr(obj, self.private_name)
             logging.info('Accessing %r giving %r', self.public_name, value)
             return value

         def __set__(self, obj, value):
             logging.info('Updating %r to %r', self.public_name, value)
             setattr(obj, self.private_name, value)

     class Person:

         name = LoggedAccess()                # First descriptor instance
         age = LoggedAccess()                 # Second descriptor instance

         def __init__(self, name, age):
             self.name = name                 # Calls the first descriptor
             self.age = age                   # Calls the second descriptor

         def birthday(self):
             self.age += 1

An interactive session shows that the ‘Person’ class has called *note
__set_name__(): e4a. so that the field names would be recorded.  Here we
call *note vars(): 1e0b. to look up the descriptor without triggering
it:

     >>> vars(vars(Person)['name'])
     {'public_name': 'name', 'private_name': '_name'}
     >>> vars(vars(Person)['age'])
     {'public_name': 'age', 'private_name': '_age'}

The new class now logs access to both 'name' and 'age':

     >>> pete = Person('Peter P', 10)
     INFO:root:Updating 'name' to 'Peter P'
     INFO:root:Updating 'age' to 10
     >>> kate = Person('Catherine C', 20)
     INFO:root:Updating 'name' to 'Catherine C'
     INFO:root:Updating 'age' to 20

The two 'Person' instances contain only the private names:

     >>> vars(pete)
     {'_name': 'Peter P', '_age': 10}
     >>> vars(kate)
     {'_name': 'Catherine C', '_age': 20}


File: python.info,  Node: Closing thoughts,  Prev: Customized names,  Up: Primer

9.4.1.5 Closing thoughts
........................

A *note descriptor: 1869. is what we call any object that defines *note
__get__(): 16ef, *note __set__(): 239b, or *note __delete__(): 1937.

Optionally, descriptors can have a *note __set_name__(): e4a. method.
This is only used in cases where a descriptor needs to know either the
class where it was created or the name of class variable it was assigned
to.  (This method, if present, is called even if the class is not a
descriptor.)

Descriptors get invoked by the dot operator during attribute lookup.  If
a descriptor is accessed indirectly with
‘vars(some_class)[descriptor_name]’, the descriptor instance is returned
without invoking it.

Descriptors only work when used as class variables.  When put in
instances, they have no effect.

The main motivation for descriptors is to provide a hook allowing
objects stored in class variables to control what happens during
attribute lookup.

Traditionally, the calling class controls what happens during lookup.
Descriptors invert that relationship and allow the data being looked-up
to have a say in the matter.

Descriptors are used throughout the language.  It is how functions turn
into bound methods.  Common tools like *note classmethod(): 48f, *note
staticmethod(): 453, *note property(): 4b4, and *note
functools.cached_property(): 764. are all implemented as descriptors.


File: python.info,  Node: Complete Practical Example,  Next: Technical Tutorial,  Prev: Primer,  Up: Descriptor Guide

9.4.2 Complete Practical Example
--------------------------------

In this example, we create a practical and powerful tool for locating
notoriously hard to find data corruption bugs.

* Menu:

* Validator class::
* Custom validators::
* Practical application::


File: python.info,  Node: Validator class,  Next: Custom validators,  Up: Complete Practical Example

9.4.2.1 Validator class
.......................

A validator is a descriptor for managed attribute access.  Prior to
storing any data, it verifies that the new value meets various type and
range restrictions.  If those restrictions aren’t met, it raises an
exception to prevent data corruption at its source.

This ‘Validator’ class is both an *note abstract base class: 13be. and a
managed attribute descriptor:

     from abc import ABC, abstractmethod

     class Validator(ABC):

         def __set_name__(self, owner, name):
             self.private_name = '_' + name

         def __get__(self, obj, objtype=None):
             return getattr(obj, self.private_name)

         def __set__(self, obj, value):
             self.validate(value)
             setattr(obj, self.private_name, value)

         @abstractmethod
         def validate(self, value):
             pass

Custom validators need to inherit from ‘Validator’ and must supply a
‘validate()’ method to test various restrictions as needed.


File: python.info,  Node: Custom validators,  Next: Practical application,  Prev: Validator class,  Up: Complete Practical Example

9.4.2.2 Custom validators
.........................

Here are three practical data validation utilities:

  1. ‘OneOf’ verifies that a value is one of a restricted set of
     options.

  2. ‘Number’ verifies that a value is either an *note int: 19b. or
     *note float: 196.  Optionally, it verifies that a value is between
     a given minimum or maximum.

  3. ‘String’ verifies that a value is a *note str: 169.  Optionally, it
     validates a given minimum or maximum length.  It can validate a
     user-defined predicate(1) as well.

     class OneOf(Validator):

         def __init__(self, *options):
             self.options = set(options)

         def validate(self, value):
             if value not in self.options:
                 raise ValueError(
                     f'Expected {value!r} to be one of {self.options!r}'
                 )

     class Number(Validator):

         def __init__(self, minvalue=None, maxvalue=None):
             self.minvalue = minvalue
             self.maxvalue = maxvalue

         def validate(self, value):
             if not isinstance(value, (int, float)):
                 raise TypeError(f'Expected {value!r} to be an int or float')
             if self.minvalue is not None and value < self.minvalue:
                 raise ValueError(
                     f'Expected {value!r} to be at least {self.minvalue!r}'
                 )
             if self.maxvalue is not None and value > self.maxvalue:
                 raise ValueError(
                     f'Expected {value!r} to be no more than {self.maxvalue!r}'
                 )

     class String(Validator):

         def __init__(self, minsize=None, maxsize=None, predicate=None):
             self.minsize = minsize
             self.maxsize = maxsize
             self.predicate = predicate

         def validate(self, value):
             if not isinstance(value, str):
                 raise TypeError(f'Expected {value!r} to be a str')
             if self.minsize is not None and len(value) < self.minsize:
                 raise ValueError(
                     f'Expected {value!r} to be no smaller than {self.minsize!r}'
                 )
             if self.maxsize is not None and len(value) > self.maxsize:
                 raise ValueError(
                     f'Expected {value!r} to be no bigger than {self.maxsize!r}'
                 )
             if self.predicate is not None and not self.predicate(value):
                 raise ValueError(
                     f'Expected {self.predicate} to be true for {value!r}'
                 )

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Predicate_(mathematical_logic)


File: python.info,  Node: Practical application,  Prev: Custom validators,  Up: Complete Practical Example

9.4.2.3 Practical application
.............................

Here’s how the data validators can be used in a real class:

     class Component:

         name = String(minsize=3, maxsize=10, predicate=str.isupper)
         kind = OneOf('wood', 'metal', 'plastic')
         quantity = Number(minvalue=0)

         def __init__(self, name, kind, quantity):
             self.name = name
             self.kind = kind
             self.quantity = quantity

The descriptors prevent invalid instances from being created:

     >>> Component('Widget', 'metal', 5)      # Blocked: 'Widget' is not all uppercase
     Traceback (most recent call last):
         ...
     ValueError: Expected <method 'isupper' of 'str' objects> to be true for 'Widget'

     >>> Component('WIDGET', 'metle', 5)      # Blocked: 'metle' is misspelled
     Traceback (most recent call last):
         ...
     ValueError: Expected 'metle' to be one of {'metal', 'plastic', 'wood'}

     >>> Component('WIDGET', 'metal', -5)     # Blocked: -5 is negative
     Traceback (most recent call last):
         ...
     ValueError: Expected -5 to be at least 0

     >>> Component('WIDGET', 'metal', 'V')    # Blocked: 'V' isn't a number
     Traceback (most recent call last):
         ...
     TypeError: Expected 'V' to be an int or float

     >>> c = Component('WIDGET', 'metal', 5)  # Allowed:  The inputs are valid


File: python.info,  Node: Technical Tutorial,  Next: Pure Python Equivalents,  Prev: Complete Practical Example,  Up: Descriptor Guide

9.4.3 Technical Tutorial
------------------------

What follows is a more technical tutorial for the mechanics and details
of how descriptors work.

* Menu:

* Abstract::
* Definition and introduction::
* Descriptor protocol::
* Overview of descriptor invocation::
* Invocation from an instance::
* Invocation from a class::
* Invocation from super::
* Summary of invocation logic::
* Automatic name notification::
* ORM example::


File: python.info,  Node: Abstract,  Next: Definition and introduction,  Up: Technical Tutorial

9.4.3.1 Abstract
................

Defines descriptors, summarizes the protocol, and shows how descriptors
are called.  Provides an example showing how object relational mappings
work.

Learning about descriptors not only provides access to a larger toolset,
it creates a deeper understanding of how Python works.


File: python.info,  Node: Definition and introduction,  Next: Descriptor protocol,  Prev: Abstract,  Up: Technical Tutorial

9.4.3.2 Definition and introduction
...................................

In general, a descriptor is an attribute value that has one of the
methods in the descriptor protocol.  Those methods are *note __get__():
16ef, *note __set__(): 239b, and *note __delete__(): 1937.  If any of
those methods are defined for an attribute, it is said to be a *note
descriptor: 1869.

The default behavior for attribute access is to get, set, or delete the
attribute from an object’s dictionary.  For instance, ‘a.x’ has a lookup
chain starting with ‘a.__dict__['x']’, then ‘type(a).__dict__['x']’, and
continuing through the method resolution order of ‘type(a)’.  If the
looked-up value is an object defining one of the descriptor methods,
then Python may override the default behavior and invoke the descriptor
method instead.  Where this occurs in the precedence chain depends on
which descriptor methods were defined.

Descriptors are a powerful, general purpose protocol.  They are the
mechanism behind properties, methods, static methods, class methods, and
*note super(): 1a6.  They are used throughout Python itself.
Descriptors simplify the underlying C code and offer a flexible set of
new tools for everyday Python programs.


File: python.info,  Node: Descriptor protocol,  Next: Overview of descriptor invocation,  Prev: Definition and introduction,  Up: Technical Tutorial

9.4.3.3 Descriptor protocol
...........................

‘descr.__get__(self, obj, type=None)’

‘descr.__set__(self, obj, value)’

‘descr.__delete__(self, obj)’

That is all there is to it.  Define any of these methods and an object
is considered a descriptor and can override default behavior upon being
looked up as an attribute.

If an object defines *note __set__(): 239b. or *note __delete__(): 1937,
it is considered a data descriptor.  Descriptors that only define *note
__get__(): 16ef. are called non-data descriptors (they are often used
for methods but other uses are possible).

Data and non-data descriptors differ in how overrides are calculated
with respect to entries in an instance’s dictionary.  If an instance’s
dictionary has an entry with the same name as a data descriptor, the
data descriptor takes precedence.  If an instance’s dictionary has an
entry with the same name as a non-data descriptor, the dictionary entry
takes precedence.

To make a read-only data descriptor, define both *note __get__(): 16ef.
and *note __set__(): 239b. with the *note __set__(): 239b. raising an
*note AttributeError: 5f0. when called.  Defining the *note __set__():
239b. method with an exception raising placeholder is enough to make it
a data descriptor.


File: python.info,  Node: Overview of descriptor invocation,  Next: Invocation from an instance,  Prev: Descriptor protocol,  Up: Technical Tutorial

9.4.3.4 Overview of descriptor invocation
.........................................

A descriptor can be called directly with ‘desc.__get__(obj)’ or
‘desc.__get__(None, cls)’.

But it is more common for a descriptor to be invoked automatically from
attribute access.

The expression ‘obj.x’ looks up the attribute ‘x’ in the chain of
namespaces for ‘obj’.  If the search finds a descriptor outside of the
instance *note __dict__: 77e, its *note __get__(): 16ef. method is
invoked according to the precedence rules listed below.

The details of invocation depend on whether ‘obj’ is an object, class,
or instance of super.


File: python.info,  Node: Invocation from an instance,  Next: Invocation from a class,  Prev: Overview of descriptor invocation,  Up: Technical Tutorial

9.4.3.5 Invocation from an instance
...................................

Instance lookup scans through a chain of namespaces giving data
descriptors the highest priority, followed by instance variables, then
non-data descriptors, then class variables, and lastly *note
__getattr__(): 6fb. if it is provided.

If a descriptor is found for ‘a.x’, then it is invoked with:
‘desc.__get__(a, type(a))’.

The logic for a dotted lookup is in *note object.__getattribute__():
dcd.  Here is a pure Python equivalent:

     def find_name_in_mro(cls, name, default):
         "Emulate _PyType_Lookup() in Objects/typeobject.c"
         for base in cls.__mro__:
             if name in vars(base):
                 return vars(base)[name]
         return default

     def object_getattribute(obj, name):
         "Emulate PyObject_GenericGetAttr() in Objects/object.c"
         null = object()
         objtype = type(obj)
         cls_var = find_name_in_mro(objtype, name, null)
         descr_get = getattr(type(cls_var), '__get__', null)
         if descr_get is not null:
             if (hasattr(type(cls_var), '__set__')
                 or hasattr(type(cls_var), '__delete__')):
                 return descr_get(cls_var, obj, objtype)     # data descriptor
         if hasattr(obj, '__dict__') and name in vars(obj):
             return vars(obj)[name]                          # instance variable
         if descr_get is not null:
             return descr_get(cls_var, obj, objtype)         # non-data descriptor
         if cls_var is not null:
             return cls_var                                  # class variable
         raise AttributeError(name)

Note, there is no *note __getattr__(): 6fb. hook in the *note
__getattribute__(): dcd. code.  That is why calling *note
__getattribute__(): dcd. directly or with ‘super().__getattribute__’
will bypass *note __getattr__(): 6fb. entirely.

Instead, it is the dot operator and the *note getattr(): dcc. function
that are responsible for invoking *note __getattr__(): 6fb. whenever
*note __getattribute__(): dcd. raises an *note AttributeError: 5f0.
Their logic is encapsulated in a helper function:

     def getattr_hook(obj, name):
         "Emulate slot_tp_getattr_hook() in Objects/typeobject.c"
         try:
             return obj.__getattribute__(name)
         except AttributeError:
             if not hasattr(type(obj), '__getattr__'):
                 raise
         return type(obj).__getattr__(obj, name)             # __getattr__


File: python.info,  Node: Invocation from a class,  Next: Invocation from super,  Prev: Invocation from an instance,  Up: Technical Tutorial

9.4.3.6 Invocation from a class
...............................

The logic for a dotted lookup such as ‘A.x’ is in
‘type.__getattribute__()’.  The steps are similar to those for
‘object.__getattribute__()’ but the instance dictionary lookup is
replaced by a search through the class’s *note method resolution order:
25bd.

If a descriptor is found, it is invoked with ‘desc.__get__(None, A)’.

The full C implementation can be found in ‘type_getattro()’ and
‘_PyType_Lookup()’ in Objects/typeobject.c(1).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Objects/typeobject.c


File: python.info,  Node: Invocation from super,  Next: Summary of invocation logic,  Prev: Invocation from a class,  Up: Technical Tutorial

9.4.3.7 Invocation from super
.............................

The logic for super’s dotted lookup is in the *note __getattribute__():
dcd. method for object returned by *note super(): 1a6.

A dotted lookup such as ‘super(A, obj).m’ searches
‘obj.__class__.__mro__’ for the base class ‘B’ immediately following ‘A’
and then returns ‘B.__dict__['m'].__get__(obj, A)’.  If not a
descriptor, ‘m’ is returned unchanged.

The full C implementation can be found in ‘super_getattro()’ in
Objects/typeobject.c(1).  A pure Python equivalent can be found in
Guido's Tutorial(2).

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Objects/typeobject.c

   (2) 
https://www.python.org/download/releases/2.2.3/descrintro/#cooperation


File: python.info,  Node: Summary of invocation logic,  Next: Automatic name notification,  Prev: Invocation from super,  Up: Technical Tutorial

9.4.3.8 Summary of invocation logic
...................................

The mechanism for descriptors is embedded in the *note
__getattribute__(): dcd. methods for *note object: c80, *note type: f46,
and *note super(): 1a6.

The important points to remember are:

   * Descriptors are invoked by the *note __getattribute__(): dcd.
     method.

   * Classes inherit this machinery from *note object: c80, *note type:
     f46, or *note super(): 1a6.

   * Overriding *note __getattribute__(): dcd. prevents automatic
     descriptor calls because all the descriptor logic is in that
     method.

   * ‘object.__getattribute__()’ and ‘type.__getattribute__()’ make
     different calls to *note __get__(): 16ef.  The first includes the
     instance and may include the class.  The second puts in ‘None’ for
     the instance and always includes the class.

   * Data descriptors always override instance dictionaries.

   * Non-data descriptors may be overridden by instance dictionaries.


File: python.info,  Node: Automatic name notification,  Next: ORM example,  Prev: Summary of invocation logic,  Up: Technical Tutorial

9.4.3.9 Automatic name notification
...................................

Sometimes it is desirable for a descriptor to know what class variable
name it was assigned to.  When a new class is created, the *note type:
f46. metaclass scans the dictionary of the new class.  If any of the
entries are descriptors and if they define *note __set_name__(): e4a,
that method is called with two arguments.  The 'owner' is the class
where the descriptor is used, and the 'name' is the class variable the
descriptor was assigned to.

The implementation details are in ‘type_new()’ and ‘set_names()’ in
Objects/typeobject.c(1).

Since the update logic is in ‘type.__new__()’, notifications only take
place at the time of class creation.  If descriptors are added to the
class afterwards, *note __set_name__(): e4a. will need to be called
manually.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Objects/typeobject.c


File: python.info,  Node: ORM example,  Prev: Automatic name notification,  Up: Technical Tutorial

9.4.3.10 ORM example
....................

The following code is a simplified skeleton showing how data descriptors
could be used to implement an object relational mapping(1).

The essential idea is that the data is stored in an external database.
The Python instances only hold keys to the database’s tables.
Descriptors take care of lookups or updates:

     class Field:

         def __set_name__(self, owner, name):
             self.fetch = f'SELECT {name} FROM {owner.table} WHERE {owner.key}=?;'
             self.store = f'UPDATE {owner.table} SET {name}=? WHERE {owner.key}=?;'

         def __get__(self, obj, objtype=None):
             return conn.execute(self.fetch, [obj.key]).fetchone()[0]

         def __set__(self, obj, value):
             conn.execute(self.store, [value, obj.key])
             conn.commit()

We can use the ‘Field’ class to define models(2) that describe the
schema for each table in a database:

     class Movie:
         table = 'Movies'                    # Table name
         key = 'title'                       # Primary key
         director = Field()
         year = Field()

         def __init__(self, key):
             self.key = key

     class Song:
         table = 'Music'
         key = 'title'
         artist = Field()
         year = Field()
         genre = Field()

         def __init__(self, key):
             self.key = key

To use the models, first connect to the database:

     >>> import sqlite3
     >>> conn = sqlite3.connect('entertainment.db')

An interactive session shows how data is retrieved from the database and
how it can be updated:

     >>> Movie('Star Wars').director
     'George Lucas'
     >>> jaws = Movie('Jaws')
     >>> f'Released in {jaws.year} by {jaws.director}'
     'Released in 1975 by Steven Spielberg'

     >>> Song('Country Roads').artist
     'John Denver'

     >>> Movie('Star Wars').director = 'J.J. Abrams'
     >>> Movie('Star Wars').director
     'J.J. Abrams'

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Object%E2%80%93relational_mapping

   (2) https://en.wikipedia.org/wiki/Database_model


File: python.info,  Node: Pure Python Equivalents,  Prev: Technical Tutorial,  Up: Descriptor Guide

9.4.4 Pure Python Equivalents
-----------------------------

The descriptor protocol is simple and offers exciting possibilities.
Several use cases are so common that they have been prepackaged into
built-in tools.  Properties, bound methods, static methods, class
methods, and __slots__ are all based on the descriptor protocol.

* Menu:

* Properties::
* Functions and methods::
* Kinds of methods::
* Static methods::
* Class methods::
* Member objects and __slots__::


File: python.info,  Node: Properties,  Next: Functions and methods,  Up: Pure Python Equivalents

9.4.4.1 Properties
..................

Calling *note property(): 4b4. is a succinct way of building a data
descriptor that triggers a function call upon access to an attribute.
Its signature is:

     property(fget=None, fset=None, fdel=None, doc=None) -> property

The documentation shows a typical use to define a managed attribute ‘x’:

     class C:
         def getx(self): return self.__x
         def setx(self, value): self.__x = value
         def delx(self): del self.__x
         x = property(getx, setx, delx, "I'm the 'x' property.")

To see how *note property(): 4b4. is implemented in terms of the
descriptor protocol, here is a pure Python equivalent that implements
most of the core functionality:

     class Property:
         "Emulate PyProperty_Type() in Objects/descrobject.c"

         def __init__(self, fget=None, fset=None, fdel=None, doc=None):
             self.fget = fget
             self.fset = fset
             self.fdel = fdel
             if doc is None and fget is not None:
                 doc = fget.__doc__
             self.__doc__ = doc

         def __set_name__(self, owner, name):
             self.__name__ = name

         def __get__(self, obj, objtype=None):
             if obj is None:
                 return self
             if self.fget is None:
                 raise AttributeError
             return self.fget(obj)

         def __set__(self, obj, value):
             if self.fset is None:
                 raise AttributeError
             self.fset(obj, value)

         def __delete__(self, obj):
             if self.fdel is None:
                 raise AttributeError
             self.fdel(obj)

         def getter(self, fget):
             return type(self)(fget, self.fset, self.fdel, self.__doc__)

         def setter(self, fset):
             return type(self)(self.fget, fset, self.fdel, self.__doc__)

         def deleter(self, fdel):
             return type(self)(self.fget, self.fset, fdel, self.__doc__)

The *note property(): 4b4. builtin helps whenever a user interface has
granted attribute access and then subsequent changes require the
intervention of a method.

For instance, a spreadsheet class may grant access to a cell value
through ‘Cell('b10').value’.  Subsequent improvements to the program
require the cell to be recalculated on every access; however, the
programmer does not want to affect existing client code accessing the
attribute directly.  The solution is to wrap access to the value
attribute in a property data descriptor:

     class Cell:
         ...

         @property
         def value(self):
             "Recalculate the cell before returning value"
             self.recalc()
             return self._value

Either the built-in *note property(): 4b4. or our ‘Property()’
equivalent would work in this example.


File: python.info,  Node: Functions and methods,  Next: Kinds of methods,  Prev: Properties,  Up: Pure Python Equivalents

9.4.4.2 Functions and methods
.............................

Python’s object oriented features are built upon a function based
environment.  Using non-data descriptors, the two are merged seamlessly.

Functions stored in class dictionaries get turned into methods when
invoked.  Methods only differ from regular functions in that the object
instance is prepended to the other arguments.  By convention, the
instance is called 'self' but could be called 'this' or any other
variable name.

Methods can be created manually with *note types.MethodType: 1b6b. which
is roughly equivalent to:

     class MethodType:
         "Emulate PyMethod_Type in Objects/classobject.c"

         def __init__(self, func, obj):
             self.__func__ = func
             self.__self__ = obj

         def __call__(self, *args, **kwargs):
             func = self.__func__
             obj = self.__self__
             return func(obj, *args, **kwargs)

         def __getattribute__(self, name):
             "Emulate method_getset() in Objects/classobject.c"
             if name == '__doc__':
                 return self.__func__.__doc__
             return object.__getattribute__(self, name)

         def __getattr__(self, name):
             "Emulate method_getattro() in Objects/classobject.c"
             return getattr(self.__func__, name)

         def __get__(self, obj, objtype=None):
             "Emulate method_descr_get() in Objects/classobject.c"
             return self

To support automatic creation of methods, functions include the *note
__get__(): 16ef. method for binding methods during attribute access.
This means that functions are non-data descriptors that return bound
methods during dotted lookup from an instance.  Here’s how it works:

     class Function:
         ...

         def __get__(self, obj, objtype=None):
             "Simulate func_descr_get() in Objects/funcobject.c"
             if obj is None:
                 return self
             return MethodType(self, obj)

Running the following class in the interpreter shows how the function
descriptor works in practice:

     class D:
         def f(self):
              return self

     class D2:
         pass

The function has a *note qualified name: 1d0c. attribute to support
introspection:

     >>> D.f.__qualname__
     'D.f'

Accessing the function through the class dictionary does not invoke
*note __get__(): 16ef.  Instead, it just returns the underlying function
object:

     >>> D.__dict__['f']
     <function D.f at 0x00C45070>

Dotted access from a class calls *note __get__(): 16ef. which just
returns the underlying function unchanged:

     >>> D.f
     <function D.f at 0x00C45070>

The interesting behavior occurs during dotted access from an instance.
The dotted lookup calls *note __get__(): 16ef. which returns a bound
method object:

     >>> d = D()
     >>> d.f
     <bound method D.f of <__main__.D object at 0x00B18C90>>

Internally, the bound method stores the underlying function and the
bound instance:

     >>> d.f.__func__
     <function D.f at 0x00C45070>

     >>> d.f.__self__
     <__main__.D object at 0x00B18C90>

If you have ever wondered where 'self' comes from in regular methods or
where 'cls' comes from in class methods, this is it!


File: python.info,  Node: Kinds of methods,  Next: Static methods,  Prev: Functions and methods,  Up: Pure Python Equivalents

9.4.4.3 Kinds of methods
........................

Non-data descriptors provide a simple mechanism for variations on the
usual patterns of binding functions into methods.

To recap, functions have a *note __get__(): 16ef. method so that they
can be converted to a method when accessed as attributes.  The non-data
descriptor transforms an ‘obj.f(*args)’ call into ‘f(obj, *args)’.
Calling ‘cls.f(*args)’ becomes ‘f(*args)’.

This chart summarizes the binding and its two most useful variants:

     Transformation        Called from an object      Called from a class
                                                      
     ------------------------------------------------------------------------
                                                      
     function              f(obj, *args)              f(*args)
                                                      
                                                      
     staticmethod          f(*args)                   f(*args)
                                                      
                                                      
     classmethod           f(type(obj), *args)        f(cls, *args)
                                                      


File: python.info,  Node: Static methods,  Next: Class methods,  Prev: Kinds of methods,  Up: Pure Python Equivalents

9.4.4.4 Static methods
......................

Static methods return the underlying function without changes.  Calling
either ‘c.f’ or ‘C.f’ is the equivalent of a direct lookup into
‘object.__getattribute__(c, "f")’ or ‘object.__getattribute__(C, "f")’.
As a result, the function becomes identically accessible from either an
object or a class.

Good candidates for static methods are methods that do not reference the
‘self’ variable.

For instance, a statistics package may include a container class for
experimental data.  The class provides normal methods for computing the
average, mean, median, and other descriptive statistics that depend on
the data.  However, there may be useful functions which are conceptually
related but do not depend on the data.  For instance, ‘erf(x)’ is handy
conversion routine that comes up in statistical work but does not
directly depend on a particular dataset.  It can be called either from
an object or the class: ‘s.erf(1.5) --> 0.9332’ or ‘Sample.erf(1.5) -->
0.9332’.

Since static methods return the underlying function with no changes, the
example calls are unexciting:

     class E:
         @staticmethod
         def f(x):
             return x * 10

     >>> E.f(3)
     30
     >>> E().f(3)
     30

Using the non-data descriptor protocol, a pure Python version of *note
staticmethod(): 453. would look like this:

     import functools

     class StaticMethod:
         "Emulate PyStaticMethod_Type() in Objects/funcobject.c"

         def __init__(self, f):
             self.f = f
             functools.update_wrapper(self, f)

         def __get__(self, obj, objtype=None):
             return self.f

         def __call__(self, *args, **kwds):
             return self.f(*args, **kwds)

         @property
         def __annotations__(self):
             return self.f.__annotations__

The *note functools.update_wrapper(): 1224. call adds a ‘__wrapped__’
attribute that refers to the underlying function.  Also it carries
forward the attributes necessary to make the wrapper look like the
wrapped function, including *note __name__: 14dc, *note __qualname__:
2330, and *note __doc__: 13e1.


File: python.info,  Node: Class methods,  Next: Member objects and __slots__,  Prev: Static methods,  Up: Pure Python Equivalents

9.4.4.5 Class methods
.....................

Unlike static methods, class methods prepend the class reference to the
argument list before calling the function.  This format is the same for
whether the caller is an object or a class:

     class F:
         @classmethod
         def f(cls, x):
             return cls.__name__, x

     >>> F.f(3)
     ('F', 3)
     >>> F().f(3)
     ('F', 3)

This behavior is useful whenever the method only needs to have a class
reference and does not rely on data stored in a specific instance.  One
use for class methods is to create alternate class constructors.  For
example, the classmethod *note dict.fromkeys(): 24e. creates a new
dictionary from a list of keys.  The pure Python equivalent is:

     class Dict(dict):
         @classmethod
         def fromkeys(cls, iterable, value=None):
             "Emulate dict_fromkeys() in Objects/dictobject.c"
             d = cls()
             for key in iterable:
                 d[key] = value
             return d

Now a new dictionary of unique keys can be constructed like this:

     >>> d = Dict.fromkeys('abracadabra')
     >>> type(d) is Dict
     True
     >>> d
     {'a': None, 'b': None, 'r': None, 'c': None, 'd': None}

Using the non-data descriptor protocol, a pure Python version of *note
classmethod(): 48f. would look like this:

     import functools

     class ClassMethod:
         "Emulate PyClassMethod_Type() in Objects/funcobject.c"

         def __init__(self, f):
             self.f = f
             functools.update_wrapper(self, f)

         def __get__(self, obj, cls=None):
             if cls is None:
                 cls = type(obj)
             return MethodType(self.f, cls)

The *note functools.update_wrapper(): 1224. call in ‘ClassMethod’ adds a
‘__wrapped__’ attribute that refers to the underlying function.  Also it
carries forward the attributes necessary to make the wrapper look like
the wrapped function: *note __name__: 14dc, *note __qualname__: 2330,
*note __doc__: 13e1, and *note __annotations__: 13e0.


File: python.info,  Node: Member objects and __slots__,  Prev: Class methods,  Up: Pure Python Equivalents

9.4.4.6 Member objects and __slots__
....................................

When a class defines ‘__slots__’, it replaces instance dictionaries with
a fixed-length array of slot values.  From a user point of view that has
several effects:

1.  Provides immediate detection of bugs due to misspelled attribute
assignments.  Only attribute names specified in ‘__slots__’ are allowed:

     class Vehicle:
         __slots__ = ('id_number', 'make', 'model')

     >>> auto = Vehicle()
     >>> auto.id_nubmer = 'VYE483814LQEX'
     Traceback (most recent call last):
         ...
     AttributeError: 'Vehicle' object has no attribute 'id_nubmer'

2.  Helps create immutable objects where descriptors manage access to
private attributes stored in ‘__slots__’:

     class Immutable:

         __slots__ = ('_dept', '_name')          # Replace the instance dictionary

         def __init__(self, dept, name):
             self._dept = dept                   # Store to private attribute
             self._name = name                   # Store to private attribute

         @property                               # Read-only descriptor
         def dept(self):
             return self._dept

         @property
         def name(self):                         # Read-only descriptor
             return self._name

     >>> mark = Immutable('Botany', 'Mark Watney')
     >>> mark.dept
     'Botany'
     >>> mark.dept = 'Space Pirate'
     Traceback (most recent call last):
         ...
     AttributeError: property 'dept' of 'Immutable' object has no setter
     >>> mark.location = 'Mars'
     Traceback (most recent call last):
         ...
     AttributeError: 'Immutable' object has no attribute 'location'

3.  Saves memory.  On a 64-bit Linux build, an instance with two
attributes takes 48 bytes with ‘__slots__’ and 152 bytes without.  This
flyweight design pattern(1) likely only matters when a large number of
instances are going to be created.

4.  Improves speed.  Reading instance variables is 35% faster with
‘__slots__’ (as measured with Python 3.10 on an Apple M1 processor).

5.  Blocks tools like *note functools.cached_property(): 764. which
require an instance dictionary to function correctly:

     from functools import cached_property

     class CP:
         __slots__ = ()                          # Eliminates the instance dict

         @cached_property                        # Requires an instance dict
         def pi(self):
             return 4 * sum((-1.0)**n / (2.0*n + 1.0)
                            for n in reversed(range(100_000)))

     >>> CP().pi
     Traceback (most recent call last):
       ...
     TypeError: No '__dict__' attribute on 'CP' instance to cache 'pi' property.

It is not possible to create an exact drop-in pure Python version of
‘__slots__’ because it requires direct access to C structures and
control over object memory allocation.  However, we can build a mostly
faithful simulation where the actual C structure for slots is emulated
by a private ‘_slotvalues’ list.  Reads and writes to that private
structure are managed by member descriptors:

     null = object()

     class Member:

         def __init__(self, name, clsname, offset):
             'Emulate PyMemberDef in Include/structmember.h'
             # Also see descr_new() in Objects/descrobject.c
             self.name = name
             self.clsname = clsname
             self.offset = offset

         def __get__(self, obj, objtype=None):
             'Emulate member_get() in Objects/descrobject.c'
             # Also see PyMember_GetOne() in Python/structmember.c
             if obj is None:
                 return self
             value = obj._slotvalues[self.offset]
             if value is null:
                 raise AttributeError(self.name)
             return value

         def __set__(self, obj, value):
             'Emulate member_set() in Objects/descrobject.c'
             obj._slotvalues[self.offset] = value

         def __delete__(self, obj):
             'Emulate member_delete() in Objects/descrobject.c'
             value = obj._slotvalues[self.offset]
             if value is null:
                 raise AttributeError(self.name)
             obj._slotvalues[self.offset] = null

         def __repr__(self):
             'Emulate member_repr() in Objects/descrobject.c'
             return f'<Member {self.name!r} of {self.clsname!r}>'

The ‘type.__new__()’ method takes care of adding member objects to class
variables:

     class Type(type):
         'Simulate how the type metaclass adds member objects for slots'

         def __new__(mcls, clsname, bases, mapping, **kwargs):
             'Emulate type_new() in Objects/typeobject.c'
             # type_new() calls PyTypeReady() which calls add_methods()
             slot_names = mapping.get('slot_names', [])
             for offset, name in enumerate(slot_names):
                 mapping[name] = Member(name, clsname, offset)
             return type.__new__(mcls, clsname, bases, mapping, **kwargs)

The *note object.__new__(): 7a1. method takes care of creating instances
that have slots instead of an instance dictionary.  Here is a rough
simulation in pure Python:

     class Object:
         'Simulate how object.__new__() allocates memory for __slots__'

         def __new__(cls, *args, **kwargs):
             'Emulate object_new() in Objects/typeobject.c'
             inst = super().__new__(cls)
             if hasattr(cls, 'slot_names'):
                 empty_slots = [null] * len(cls.slot_names)
                 object.__setattr__(inst, '_slotvalues', empty_slots)
             return inst

         def __setattr__(self, name, value):
             'Emulate _PyObject_GenericSetAttrWithDict() Objects/object.c'
             cls = type(self)
             if hasattr(cls, 'slot_names') and name not in cls.slot_names:
                 raise AttributeError(
                     f'{cls.__name__!r} object has no attribute {name!r}'
                 )
             super().__setattr__(name, value)

         def __delattr__(self, name):
             'Emulate _PyObject_GenericSetAttrWithDict() Objects/object.c'
             cls = type(self)
             if hasattr(cls, 'slot_names') and name not in cls.slot_names:
                 raise AttributeError(
                     f'{cls.__name__!r} object has no attribute {name!r}'
                 )
             super().__delattr__(name)

To use the simulation in a real class, just inherit from ‘Object’ and
set the *note metaclass: 23b6. to ‘Type’:

     class H(Object, metaclass=Type):
         'Instance variables stored in slots'

         slot_names = ['x', 'y']

         def __init__(self, x, y):
             self.x = x
             self.y = y

At this point, the metaclass has loaded member objects for 'x' and 'y':

     >>> from pprint import pp
     >>> pp(dict(vars(H)))
     {'__module__': '__main__',
      '__doc__': 'Instance variables stored in slots',
      'slot_names': ['x', 'y'],
      '__init__': <function H.__init__ at 0x7fb5d302f9d0>,
      'x': <Member 'x' of 'H'>,
      'y': <Member 'y' of 'H'>}

When instances are created, they have a ‘slot_values’ list where the
attributes are stored:

     >>> h = H(10, 20)
     >>> vars(h)
     {'_slotvalues': [10, 20]}
     >>> h.x = 55
     >>> vars(h)
     {'_slotvalues': [55, 20]}

Misspelled or unassigned attributes will raise an exception:

     >>> h.xz
     Traceback (most recent call last):
         ...
     AttributeError: 'H' object has no attribute 'xz'

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Flyweight_pattern


File: python.info,  Node: Debugging C API extensions and CPython Internals with GDB,  Next: Enum HOWTO,  Prev: Descriptor Guide,  Up: Python HOWTOs

9.5 Debugging C API extensions and CPython Internals with GDB
=============================================================

This document explains how the Python GDB extension, ‘python-gdb.py’,
can be used with the GDB debugger to debug CPython extensions and the
CPython interpreter itself.

When debugging low-level problems such as crashes or deadlocks, a
low-level debugger, such as GDB, is useful to diagnose and correct the
issue.  By default, GDB (or any of its front-ends) doesn’t support
high-level information specific to the CPython interpreter.

The ‘python-gdb.py’ extension adds CPython interpreter information to
GDB. The extension helps introspect the stack of currently executing
Python functions.  Given a Python object represented by a *note
PyObject: 5df.* pointer, the extension surfaces the type and value of
the object.

Developers who are working on CPython extensions or tinkering with parts
of CPython that are written in C can use this document to learn how to
use the ‘python-gdb.py’ extension with GDB.

     Nota: This document assumes that you are familiar with the basics
     of GDB and the CPython C API. It consolidates guidance from the
     devguide(1) and the Python wiki(2).

* Menu:

* Prerequisites::
* Using the Debug build and Development mode::
* Using the python-gdb extension::
* Use with GDB commands::

   ---------- Footnotes ----------

   (1) https://devguide.python.org

   (2) https://wiki.python.org/moin/DebuggingWithGdb


File: python.info,  Node: Prerequisites,  Next: Using the Debug build and Development mode,  Up: Debugging C API extensions and CPython Internals with GDB

9.5.1 Prerequisites
-------------------

You need to have:

   - GDB 7 or later.  (For earlier versions of GDB, see ‘Misc/gdbinit’
     in the sources of Python 3.11 or earlier.)

   - GDB-compatible debugging information for Python and any extension
     you are debugging.

   - The ‘python-gdb.py’ extension.

The extension is built with Python, but might be distributed separately
or not at all.  Below, we include tips for a few common systems as
examples.  Note that even if the instructions match your system, they
might be outdated.

* Menu:

* Setup with Python built from source::
* Setup for Python from a Linux distro::


File: python.info,  Node: Setup with Python built from source,  Next: Setup for Python from a Linux distro,  Up: Prerequisites

9.5.1.1 Setup with Python built from source
...........................................

When you build CPython from source, debugging information should be
available, and the build should add a ‘python-gdb.py’ file to the root
directory of your repository.

To activate support, you must add the directory containing
‘python-gdb.py’ to GDB’s «auto-load-safe-path».  If you haven’t done
this, recent versions of GDB will print out a warning with instructions
on how to do this.

     Nota: If you do not see instructions for your version of GDB, put
     this in your configuration file (‘~/.gdbinit’ or
     ‘~/.config/gdb/gdbinit’):

          add-auto-load-safe-path /path/to/cpython

     You can also add multiple paths, separated by ‘:’.


File: python.info,  Node: Setup for Python from a Linux distro,  Prev: Setup with Python built from source,  Up: Prerequisites

9.5.1.2 Setup for Python from a Linux distro
............................................

Most Linux systems provide debug information for the system Python in a
package called ‘python-debuginfo’, ‘python-dbg’ or similar.  For
example:

   - Fedora:

               sudo dnf install gdb
               sudo dnf debuginfo-install python3

   - Ubuntu:

               sudo apt install gdb python3-dbg

On several recent Linux systems, GDB can download debugging symbols
automatically using 'debuginfod'.  However, this will not install the
‘python-gdb.py’ extension; you generally do need to install the debug
info package separately.


File: python.info,  Node: Using the Debug build and Development mode,  Next: Using the python-gdb extension,  Prev: Prerequisites,  Up: Debugging C API extensions and CPython Internals with GDB

9.5.2 Using the Debug build and Development mode
------------------------------------------------

For easier debugging, you might want to:

   - Use a *note debug build: 50a. of Python.  (When building from
     source, use ‘configure --with-pydebug’.  On Linux distros, install
     and run a package like ‘python-debug’ or ‘python-dbg’, if
     available.)

   - Use the runtime *note development mode: 509. (‘-X dev’).

Both enable extra assertions and disable some optimizations.  Sometimes
this hides the bug you are trying to find, but in most cases they make
the process easier.


File: python.info,  Node: Using the python-gdb extension,  Next: Use with GDB commands,  Prev: Using the Debug build and Development mode,  Up: Debugging C API extensions and CPython Internals with GDB

9.5.3 Using the ‘python-gdb’ extension
--------------------------------------

When the extension is loaded, it provides two main features: pretty
printers for Python values, and additional commands.

* Menu:

* Pretty-printers::
* py-list::
* py-up and py-down::
* py-bt::
* py-print::
* py-locals::


File: python.info,  Node: Pretty-printers,  Next: py-list,  Up: Using the python-gdb extension

9.5.3.1 Pretty-printers
.......................

This is what a GDB backtrace looks like (truncated) when this extension
is enabled:

     #0  0x000000000041a6b1 in PyObject_Malloc (nbytes=Cannot access memory at address 0x7fffff7fefe8
     ) at Objects/obmalloc.c:748
     #1  0x000000000041b7c0 in _PyObject_DebugMallocApi (id=111 'o', nbytes=24) at Objects/obmalloc.c:1445
     #2  0x000000000041b717 in _PyObject_DebugMalloc (nbytes=24) at Objects/obmalloc.c:1412
     #3  0x000000000044060a in _PyUnicode_New (length=11) at Objects/unicodeobject.c:346
     #4  0x00000000004466aa in PyUnicodeUCS2_DecodeUTF8Stateful (s=0x5c2b8d "__lltrace__", size=11, errors=0x0, consumed=
         0x0) at Objects/unicodeobject.c:2531
     #5  0x0000000000446647 in PyUnicodeUCS2_DecodeUTF8 (s=0x5c2b8d "__lltrace__", size=11, errors=0x0)
         at Objects/unicodeobject.c:2495
     #6  0x0000000000440d1b in PyUnicodeUCS2_FromStringAndSize (u=0x5c2b8d "__lltrace__", size=11)
         at Objects/unicodeobject.c:551
     #7  0x0000000000440d94 in PyUnicodeUCS2_FromString (u=0x5c2b8d "__lltrace__") at Objects/unicodeobject.c:569
     #8  0x0000000000584abd in PyDict_GetItemString (v=
         {'Yuck': <type at remote 0xad4730>, '__builtins__': <module at remote 0x7ffff7fd5ee8>, '__file__': 'Lib/test/crashers/nasty_eq_vs_dict.py', '__package__': None, 'y': <Yuck(i=0) at remote 0xaacd80>, 'dict': {0: 0, 1: 1, 2: 2, 3: 3}, '__cached__': None, '__name__': '__main__', 'z': <Yuck(i=0) at remote 0xaace60>, '__doc__': None}, key=
         0x5c2b8d "__lltrace__") at Objects/dictobject.c:2171

Notice how the dictionary argument to ‘PyDict_GetItemString’ is
displayed as its ‘repr()’, rather than an opaque ‘PyObject *’ pointer.

The extension works by supplying a custom printing routine for values of
type ‘PyObject *’.  If you need to access lower-level details of an
object, then cast the value to a pointer of the appropriate type.  For
example:

     (gdb) p globals
     $1 = {'__builtins__': <module at remote 0x7ffff7fb1868>, '__name__':
     '__main__', 'ctypes': <module at remote 0x7ffff7f14360>, '__doc__': None,
     '__package__': None}

     (gdb) p *(PyDictObject*)globals
     $2 = {ob_refcnt = 3, ob_type = 0x3dbdf85820, ma_fill = 5, ma_used = 5,
     ma_mask = 7, ma_table = 0x63d0f8, ma_lookup = 0x3dbdc7ea70
     <lookdict_string>, ma_smalltable = {{me_hash = 7065186196740147912,
     me_key = '__builtins__', me_value = <module at remote 0x7ffff7fb1868>},
     {me_hash = -368181376027291943, me_key = '__name__',
     me_value ='__main__'}, {me_hash = 0, me_key = 0x0, me_value = 0x0},
     {me_hash = 0, me_key = 0x0, me_value = 0x0},
     {me_hash = -9177857982131165996, me_key = 'ctypes',
     me_value = <module at remote 0x7ffff7f14360>},
     {me_hash = -8518757509529533123, me_key = '__doc__', me_value = None},
     {me_hash = 0, me_key = 0x0, me_value = 0x0}, {
       me_hash = 6614918939584953775, me_key = '__package__', me_value = None}}}

Note that the pretty-printers do not actually call ‘repr()’.  For basic
types, they try to match its result closely.

An area that can be confusing is that the custom printer for some types
look a lot like GDB’s built-in printer for standard types.  For example,
the pretty-printer for a Python ‘int’ (*note PyLongObject: 39e.*) gives
a representation that is not distinguishable from one of a regular
machine-level integer:

     (gdb) p some_machine_integer
     $3 = 42

     (gdb) p some_python_integer
     $4 = 42

The internal structure can be revealed with a cast to *note
PyLongObject: 39e.*:

     (gdb) p *(PyLongObject*)some_python_integer
     $5 = {ob_base = {ob_base = {ob_refcnt = 8, ob_type = 0x3dad39f5e0}, ob_size = 1},
     ob_digit = {42}}

A similar confusion can arise with the ‘str’ type, where the output
looks a lot like gdb’s built-in printer for ‘char *’:

     (gdb) p ptr_to_python_str
     $6 = '__builtins__'

The pretty-printer for ‘str’ instances defaults to using single-quotes
(as does Python’s ‘repr’ for strings) whereas the standard printer for
‘char *’ values uses double-quotes and contains a hexadecimal address:

     (gdb) p ptr_to_char_star
     $7 = 0x6d72c0 "hello world"

Again, the implementation details can be revealed with a cast to *note
PyUnicodeObject: 998.*:

     (gdb) p *(PyUnicodeObject*)$6
     $8 = {ob_base = {ob_refcnt = 33, ob_type = 0x3dad3a95a0}, length = 12,
     str = 0x7ffff2128500, hash = 7065186196740147912, state = 1, defenc = 0x0}


File: python.info,  Node: py-list,  Next: py-up and py-down,  Prev: Pretty-printers,  Up: Using the python-gdb extension

9.5.3.2 ‘py-list’
.................

     The extension adds a ‘py-list’ command, which lists the Python
     source code (if any) for the current frame in the selected thread.
     The current line is marked with a «>»:

          (gdb) py-list
           901        if options.profile:
           902            options.profile = False
           903            profile_me()
           904            return
           905
          >906        u = UI()
           907        if not u.quit:
           908            try:
           909                gtk.main()
           910            except KeyboardInterrupt:
           911                # properly quit on a keyboard interrupt...

     Use ‘py-list START’ to list at a different line number within the
     Python source, and ‘py-list START,END’ to list a specific range of
     lines within the Python source.


File: python.info,  Node: py-up and py-down,  Next: py-bt,  Prev: py-list,  Up: Using the python-gdb extension

9.5.3.3 ‘py-up’ and ‘py-down’
.............................

     The ‘py-up’ and ‘py-down’ commands are analogous to GDB’s regular
     ‘up’ and ‘down’ commands, but try to move at the level of CPython
     frames, rather than C frames.

     GDB is not always able to read the relevant frame information,
     depending on the optimization level with which CPython was
     compiled.  Internally, the commands look for C frames that are
     executing the default frame evaluation function (that is, the core
     bytecode interpreter loop within CPython) and look up the value of
     the related ‘PyFrameObject *’.

     They emit the frame number (at the C level) within the thread.

     For example:

          (gdb) py-up
          #37 Frame 0x9420b04, for file /usr/lib/python2.6/site-packages/
          gnome_sudoku/main.py, line 906, in start_game ()
              u = UI()
          (gdb) py-up
          #40 Frame 0x948e82c, for file /usr/lib/python2.6/site-packages/
          gnome_sudoku/gnome_sudoku.py, line 22, in start_game(main=<module at remote 0xb771b7f4>)
              main.start_game()
          (gdb) py-up
          Unable to find an older python frame

     so we’re at the top of the Python stack.

     The frame numbers correspond to those displayed by GDB’s standard
     ‘backtrace’ command.  The command skips C frames which are not
     executing Python code.

     Going back down:

          (gdb) py-down
          #37 Frame 0x9420b04, for file /usr/lib/python2.6/site-packages/gnome_sudoku/main.py, line 906, in start_game ()
              u = UI()
          (gdb) py-down
          #34 (unable to read python frame information)
          (gdb) py-down
          #23 (unable to read python frame information)
          (gdb) py-down
          #19 (unable to read python frame information)
          (gdb) py-down
          #14 Frame 0x99262ac, for file /usr/lib/python2.6/site-packages/gnome_sudoku/game_selector.py, line 201, in run_swallowed_dialog (self=<NewOrSavedGameSelector(new_game_model=<gtk.ListStore at remote 0x98fab44>, puzzle=None, saved_games=[{'gsd.auto_fills': 0, 'tracking': {}, 'trackers': {}, 'notes': [], 'saved_at': 1270084485, 'game': '7 8 0 0 0 0 0 5 6 0 0 9 0 8 0 1 0 0 0 4 6 0 0 0 0 7 0 6 5 0 0 0 4 7 9 2 0 0 0 9 0 1 0 0 0 3 9 7 6 0 0 0 1 8 0 6 0 0 0 0 2 8 0 0 0 5 0 4 0 6 0 0 2 1 0 0 0 0 0 4 5\n7 8 0 0 0 0 0 5 6 0 0 9 0 8 0 1 0 0 0 4 6 0 0 0 0 7 0 6 5 1 8 3 4 7 9 2 0 0 0 9 0 1 0 0 0 3 9 7 6 0 0 0 1 8 0 6 0 0 0 0 2 8 0 0 0 5 0 4 0 6 0 0 2 1 0 0 0 0 0 4 5', 'gsd.impossible_hints': 0, 'timer.__absolute_start_time__': <float at remote 0x984b474>, 'gsd.hints': 0, 'timer.active_time': <float at remote 0x984b494>, 'timer.total_time': <float at remote 0x984b464>}], dialog=<gtk.Dialog at remote 0x98faaa4>, saved_game_model=<gtk.ListStore at remote 0x98fad24>, sudoku_maker=<SudokuMaker(terminated=False, played=[], batch_siz...(truncated)
                      swallower.run_dialog(self.dialog)
          (gdb) py-down
          #11 Frame 0x9aead74, for file /usr/lib/python2.6/site-packages/gnome_sudoku/dialog_swallower.py, line 48, in run_dialog (self=<SwappableArea(running=<gtk.Dialog at remote 0x98faaa4>, main_page=0) at remote 0x98fa6e4>, d=<gtk.Dialog at remote 0x98faaa4>)
                      gtk.main()
          (gdb) py-down
          #8 (unable to read python frame information)
          (gdb) py-down
          Unable to find a newer python frame

     and we’re at the bottom of the Python stack.

     Note that in Python 3.12 and newer, the same C stack frame can be
     used for multiple Python stack frames.  This means that ‘py-up’ and
     ‘py-down’ may move multiple Python frames at once.  For example:

          (gdb) py-up
          #6 Frame 0x7ffff7fb62b0, for file /tmp/rec.py, line 5, in recursive_function (n=0)
             time.sleep(5)
          #6 Frame 0x7ffff7fb6240, for file /tmp/rec.py, line 7, in recursive_function (n=1)
             recursive_function(n-1)
          #6 Frame 0x7ffff7fb61d0, for file /tmp/rec.py, line 7, in recursive_function (n=2)
             recursive_function(n-1)
          #6 Frame 0x7ffff7fb6160, for file /tmp/rec.py, line 7, in recursive_function (n=3)
             recursive_function(n-1)
          #6 Frame 0x7ffff7fb60f0, for file /tmp/rec.py, line 7, in recursive_function (n=4)
             recursive_function(n-1)
          #6 Frame 0x7ffff7fb6080, for file /tmp/rec.py, line 7, in recursive_function (n=5)
             recursive_function(n-1)
          #6 Frame 0x7ffff7fb6020, for file /tmp/rec.py, line 9, in <module> ()
             recursive_function(5)
          (gdb) py-up
          Unable to find an older python frame


File: python.info,  Node: py-bt,  Next: py-print,  Prev: py-up and py-down,  Up: Using the python-gdb extension

9.5.3.4 ‘py-bt’
...............

     The ‘py-bt’ command attempts to display a Python-level backtrace of
     the current thread.

     For example:

          (gdb) py-bt
          #8 (unable to read python frame information)
          #11 Frame 0x9aead74, for file /usr/lib/python2.6/site-packages/gnome_sudoku/dialog_swallower.py, line 48, in run_dialog (self=<SwappableArea(running=<gtk.Dialog at remote 0x98faaa4>, main_page=0) at remote 0x98fa6e4>, d=<gtk.Dialog at remote 0x98faaa4>)
                      gtk.main()
          #14 Frame 0x99262ac, for file /usr/lib/python2.6/site-packages/gnome_sudoku/game_selector.py, line 201, in run_swallowed_dialog (self=<NewOrSavedGameSelector(new_game_model=<gtk.ListStore at remote 0x98fab44>, puzzle=None, saved_games=[{'gsd.auto_fills': 0, 'tracking': {}, 'trackers': {}, 'notes': [], 'saved_at': 1270084485, 'game': '7 8 0 0 0 0 0 5 6 0 0 9 0 8 0 1 0 0 0 4 6 0 0 0 0 7 0 6 5 0 0 0 4 7 9 2 0 0 0 9 0 1 0 0 0 3 9 7 6 0 0 0 1 8 0 6 0 0 0 0 2 8 0 0 0 5 0 4 0 6 0 0 2 1 0 0 0 0 0 4 5\n7 8 0 0 0 0 0 5 6 0 0 9 0 8 0 1 0 0 0 4 6 0 0 0 0 7 0 6 5 1 8 3 4 7 9 2 0 0 0 9 0 1 0 0 0 3 9 7 6 0 0 0 1 8 0 6 0 0 0 0 2 8 0 0 0 5 0 4 0 6 0 0 2 1 0 0 0 0 0 4 5', 'gsd.impossible_hints': 0, 'timer.__absolute_start_time__': <float at remote 0x984b474>, 'gsd.hints': 0, 'timer.active_time': <float at remote 0x984b494>, 'timer.total_time': <float at remote 0x984b464>}], dialog=<gtk.Dialog at remote 0x98faaa4>, saved_game_model=<gtk.ListStore at remote 0x98fad24>, sudoku_maker=<SudokuMaker(terminated=False, played=[], batch_siz...(truncated)
                      swallower.run_dialog(self.dialog)
          #19 (unable to read python frame information)
          #23 (unable to read python frame information)
          #34 (unable to read python frame information)
          #37 Frame 0x9420b04, for file /usr/lib/python2.6/site-packages/gnome_sudoku/main.py, line 906, in start_game ()
              u = UI()
          #40 Frame 0x948e82c, for file /usr/lib/python2.6/site-packages/gnome_sudoku/gnome_sudoku.py, line 22, in start_game (main=<module at remote 0xb771b7f4>)
              main.start_game()

     The frame numbers correspond to those displayed by GDB’s standard
     ‘backtrace’ command.


File: python.info,  Node: py-print,  Next: py-locals,  Prev: py-bt,  Up: Using the python-gdb extension

9.5.3.5 ‘py-print’
..................

     The ‘py-print’ command looks up a Python name and tries to print
     it.  It looks in locals within the current thread, then globals,
     then finally builtins:

          (gdb) py-print self
          local 'self' = <SwappableArea(running=<gtk.Dialog at remote 0x98faaa4>,
          main_page=0) at remote 0x98fa6e4>
          (gdb) py-print __name__
          global '__name__' = 'gnome_sudoku.dialog_swallower'
          (gdb) py-print len
          builtin 'len' = <built-in function len>
          (gdb) py-print scarlet_pimpernel
          'scarlet_pimpernel' not found

     If the current C frame corresponds to multiple Python frames,
     ‘py-print’ only considers the first one.


File: python.info,  Node: py-locals,  Prev: py-print,  Up: Using the python-gdb extension

9.5.3.6 ‘py-locals’
...................

     The ‘py-locals’ command looks up all Python locals within the
     current Python frame in the selected thread, and prints their
     representations:

          (gdb) py-locals
          self = <SwappableArea(running=<gtk.Dialog at remote 0x98faaa4>,
          main_page=0) at remote 0x98fa6e4>
          d = <gtk.Dialog at remote 0x98faaa4>

     If the current C frame corresponds to multiple Python frames,
     locals from all of them will be shown:

          (gdb) py-locals
          Locals for recursive_function
          n = 0
          Locals for recursive_function
          n = 1
          Locals for recursive_function
          n = 2
          Locals for recursive_function
          n = 3
          Locals for recursive_function
          n = 4
          Locals for recursive_function
          n = 5
          Locals for <module>


File: python.info,  Node: Use with GDB commands,  Prev: Using the python-gdb extension,  Up: Debugging C API extensions and CPython Internals with GDB

9.5.4 Use with GDB commands
---------------------------

The extension commands complement GDB’s built-in commands.  For example,
you can use a frame numbers shown by ‘py-bt’ with the ‘frame’ command to
go a specific frame within the selected thread, like this:

     (gdb) py-bt
     (output snipped)
     #68 Frame 0xaa4560, for file Lib/test/regrtest.py, line 1548, in <module> ()
             main()
     (gdb) frame 68
     #68 0x00000000004cd1e6 in PyEval_EvalFrameEx (f=Frame 0xaa4560, for file Lib/test/regrtest.py, line 1548, in <module> (), throwflag=0) at Python/ceval.c:2665
     2665                            x = call_function(&sp, oparg);
     (gdb) py-list
     1543        # Run the tests in a context manager that temporary changes the CWD to a
     1544        # temporary and writable directory. If it's not possible to create or
     1545        # change the CWD, the original CWD will be used. The original CWD is
     1546        # available from test_support.SAVEDCWD.
     1547        with test_support.temp_cwd(TESTCWD, quiet=True):
     >1548            main()

The ‘info threads’ command will give you a list of the threads within
the process, and you can use the ‘thread’ command to select a different
one:

     (gdb) info threads
       105 Thread 0x7fffefa18710 (LWP 10260)  sem_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S:86
       104 Thread 0x7fffdf5fe710 (LWP 10259)  sem_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S:86
     * 1 Thread 0x7ffff7fe2700 (LWP 10145)  0x00000038e46d73e3 in select () at ../sysdeps/unix/syscall-template.S:82

You can use ‘thread apply all COMMAND’ or (‘t a a COMMAND’ for short) to
run a command on all threads.  With ‘py-bt’, this lets you see what
every thread is doing at the Python level:

     (gdb) t a a py-bt

     Thread 105 (Thread 0x7fffefa18710 (LWP 10260)):
     #5 Frame 0x7fffd00019d0, for file /home/david/coding/python-svn/Lib/threading.py, line 155, in _acquire_restore (self=<_RLock(_Verbose__verbose=False, _RLock__owner=140737354016512, _RLock__block=<thread.lock at remote 0x858770>, _RLock__count=1) at remote 0xd7ff40>, count_owner=(1, 140737213728528), count=1, owner=140737213728528)
             self.__block.acquire()
     #8 Frame 0x7fffac001640, for file /home/david/coding/python-svn/Lib/threading.py, line 269, in wait (self=<_Condition(_Condition__lock=<_RLock(_Verbose__verbose=False, _RLock__owner=140737354016512, _RLock__block=<thread.lock at remote 0x858770>, _RLock__count=1) at remote 0xd7ff40>, acquire=<instancemethod at remote 0xd80260>, _is_owned=<instancemethod at remote 0xd80160>, _release_save=<instancemethod at remote 0xd803e0>, release=<instancemethod at remote 0xd802e0>, _acquire_restore=<instancemethod at remote 0xd7ee60>, _Verbose__verbose=False, _Condition__waiters=[]) at remote 0xd7fd10>, timeout=None, waiter=<thread.lock at remote 0x858a90>, saved_state=(1, 140737213728528))
                 self._acquire_restore(saved_state)
     #12 Frame 0x7fffb8001a10, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 348, in f ()
                 cond.wait()
     #16 Frame 0x7fffb8001c40, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 37, in task (tid=140737213728528)
                     f()

     Thread 104 (Thread 0x7fffdf5fe710 (LWP 10259)):
     #5 Frame 0x7fffe4001580, for file /home/david/coding/python-svn/Lib/threading.py, line 155, in _acquire_restore (self=<_RLock(_Verbose__verbose=False, _RLock__owner=140737354016512, _RLock__block=<thread.lock at remote 0x858770>, _RLock__count=1) at remote 0xd7ff40>, count_owner=(1, 140736940992272), count=1, owner=140736940992272)
             self.__block.acquire()
     #8 Frame 0x7fffc8002090, for file /home/david/coding/python-svn/Lib/threading.py, line 269, in wait (self=<_Condition(_Condition__lock=<_RLock(_Verbose__verbose=False, _RLock__owner=140737354016512, _RLock__block=<thread.lock at remote 0x858770>, _RLock__count=1) at remote 0xd7ff40>, acquire=<instancemethod at remote 0xd80260>, _is_owned=<instancemethod at remote 0xd80160>, _release_save=<instancemethod at remote 0xd803e0>, release=<instancemethod at remote 0xd802e0>, _acquire_restore=<instancemethod at remote 0xd7ee60>, _Verbose__verbose=False, _Condition__waiters=[]) at remote 0xd7fd10>, timeout=None, waiter=<thread.lock at remote 0x858860>, saved_state=(1, 140736940992272))
                 self._acquire_restore(saved_state)
     #12 Frame 0x7fffac001c90, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 348, in f ()
                 cond.wait()
     #16 Frame 0x7fffac0011c0, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 37, in task (tid=140736940992272)
                     f()

     Thread 1 (Thread 0x7ffff7fe2700 (LWP 10145)):
     #5 Frame 0xcb5380, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 16, in _wait ()
         time.sleep(0.01)
     #8 Frame 0x7fffd00024a0, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 378, in _check_notify (self=<ConditionTests(_testMethodName='test_notify', _resultForDoCleanups=<TestResult(_original_stdout=<cStringIO.StringO at remote 0xc191e0>, skipped=[], _mirrorOutput=False, testsRun=39, buffer=False, _original_stderr=<file at remote 0x7ffff7fc6340>, _stdout_buffer=<cStringIO.StringO at remote 0xc9c7f8>, _stderr_buffer=<cStringIO.StringO at remote 0xc9c790>, _moduleSetUpFailed=False, expectedFailures=[], errors=[], _previousTestClass=<type at remote 0x928310>, unexpectedSuccesses=[], failures=[], shouldStop=False, failfast=False) at remote 0xc185a0>, _threads=(0,), _cleanups=[], _type_equality_funcs={<type at remote 0x7eba00>: <instancemethod at remote 0xd750e0>, <type at remote 0x7e7820>: <instancemethod at remote 0xd75160>, <type at remote 0x7e30e0>: <instancemethod at remote 0xd75060>, <type at remote 0x7e7d20>: <instancemethod at remote 0xd751e0>, <type at remote 0x7f19e0...(truncated)
             _wait()


File: python.info,  Node: Enum HOWTO,  Next: Functional Programming HOWTO,  Prev: Debugging C API extensions and CPython Internals with GDB,  Up: Python HOWTOs

9.6 Enum HOWTO
==============

An *note Enum: 843. is a set of symbolic names bound to unique values.
They are similar to global variables, but they offer a more useful *note
repr(): 1c1, grouping, type-safety, and a few other features.

They are most useful when you have a variable that can take one of a
limited selection of values.  For example, the days of the week:

     >>> from enum import Enum
     >>> class Weekday(Enum):
     ...     MONDAY = 1
     ...     TUESDAY = 2
     ...     WEDNESDAY = 3
     ...     THURSDAY = 4
     ...     FRIDAY = 5
     ...     SATURDAY = 6
     ...     SUNDAY = 7

Or perhaps the RGB primary colors:

     >>> from enum import Enum
     >>> class Color(Enum):
     ...     RED = 1
     ...     GREEN = 2
     ...     BLUE = 3

As you can see, creating an *note Enum: 843. is as simple as writing a
class that inherits from *note Enum: 843. itself.

     Nota: Case of Enum Members

     Because Enums are used to represent constants, and to help avoid
     issues with name clashes between mixin-class methods/attributes and
     enum names, we strongly recommend using UPPER_CASE names for
     members, and will be using that style in our examples.

Depending on the nature of the enum a member’s value may or may not be
important, but either way that value can be used to get the
corresponding member:

     >>> Weekday(3)
     <Weekday.WEDNESDAY: 3>

As you can see, the ‘repr()’ of a member shows the enum name, the member
name, and the value.  The ‘str()’ of a member shows only the enum name
and member name:

     >>> print(Weekday.THURSDAY)
     Weekday.THURSDAY

The 'type' of an enumeration member is the enum it belongs to:

     >>> type(Weekday.MONDAY)
     <enum 'Weekday'>
     >>> isinstance(Weekday.FRIDAY, Weekday)
     True

Enum members have an attribute that contains just their ‘name’:

     >>> print(Weekday.TUESDAY.name)
     TUESDAY

Likewise, they have an attribute for their ‘value’:

     >>> Weekday.WEDNESDAY.value
     3

Unlike many languages that treat enumerations solely as name/value
pairs, Python Enums can have behavior added.  For example, *note
datetime.date: 1fa. has two methods for returning the weekday: *note
weekday(): 28a4. and *note isoweekday(): 28a5.  The difference is that
one of them counts from 0-6 and the other from 1-7.  Rather than keep
track of that ourselves we can add a method to the ‘Weekday’ enum to
extract the day from the *note date: 1fa. instance and return the
matching enum member:

     @classmethod
     def from_date(cls, date):
         return cls(date.isoweekday())

The complete ‘Weekday’ enum now looks like this:

     >>> class Weekday(Enum):
     ...     MONDAY = 1
     ...     TUESDAY = 2
     ...     WEDNESDAY = 3
     ...     THURSDAY = 4
     ...     FRIDAY = 5
     ...     SATURDAY = 6
     ...     SUNDAY = 7
     ...     #
     ...     @classmethod
     ...     def from_date(cls, date):
     ...         return cls(date.isoweekday())

Now we can find out what today is!  Observe:

     >>> from datetime import date
     >>> Weekday.from_date(date.today())
     <Weekday.TUESDAY: 2>

Of course, if you’re reading this on some other day, you’ll see that day
instead.

This ‘Weekday’ enum is great if our variable only needs one day, but
what if we need several?  Maybe we’re writing a function to plot chores
during a week, and don’t want to use a *note list: 24d. – we could use a
different type of *note Enum: 843.:

     >>> from enum import Flag
     >>> class Weekday(Flag):
     ...     MONDAY = 1
     ...     TUESDAY = 2
     ...     WEDNESDAY = 4
     ...     THURSDAY = 8
     ...     FRIDAY = 16
     ...     SATURDAY = 32
     ...     SUNDAY = 64

We’ve changed two things: we’re inherited from *note Flag: 836, and the
values are all powers of 2.

Just like the original ‘Weekday’ enum above, we can have a single
selection:

     >>> first_week_day = Weekday.MONDAY
     >>> first_week_day
     <Weekday.MONDAY: 1>

But *note Flag: 836. also allows us to combine several members into a
single variable:

     >>> weekend = Weekday.SATURDAY | Weekday.SUNDAY
     >>> weekend
     <Weekday.SATURDAY|SUNDAY: 96>

You can even iterate over a *note Flag: 836. variable:

     >>> for day in weekend:
     ...     print(day)
     Weekday.SATURDAY
     Weekday.SUNDAY

Okay, let’s get some chores set up:

     >>> chores_for_ethan = {
     ...     'feed the cat': Weekday.MONDAY | Weekday.WEDNESDAY | Weekday.FRIDAY,
     ...     'do the dishes': Weekday.TUESDAY | Weekday.THURSDAY,
     ...     'answer SO questions': Weekday.SATURDAY,
     ...     }

And a function to display the chores for a given day:

     >>> def show_chores(chores, day):
     ...     for chore, days in chores.items():
     ...         if day in days:
     ...             print(chore)
     ...
     >>> show_chores(chores_for_ethan, Weekday.SATURDAY)
     answer SO questions

In cases where the actual values of the members do not matter, you can
save yourself some work and use *note auto(): e9d. for the values:

     >>> from enum import auto
     >>> class Weekday(Flag):
     ...     MONDAY = auto()
     ...     TUESDAY = auto()
     ...     WEDNESDAY = auto()
     ...     THURSDAY = auto()
     ...     FRIDAY = auto()
     ...     SATURDAY = auto()
     ...     SUNDAY = auto()
     ...     WEEKEND = SATURDAY | SUNDAY

* Menu:

* Programmatic access to enumeration members and their attributes::
* Duplicating enum members and values::
* Ensuring unique enumeration values::
* Using automatic values::
* Iteration: Iteration<2>.
* Comparisons: Comparisons<2>.
* Allowed members and attributes of enumerations::
* Restricted Enum subclassing::
* Dataclass support::
* Pickling::
* Functional API: Functional API<3>.
* Derived Enumerations::
* When to use __new__() vs. __init__(): When to use __new__ vs __init__.
* How are Enums and Flags different?::
* Enum Cookbook::
* Subclassing EnumType::


File: python.info,  Node: Programmatic access to enumeration members and their attributes,  Next: Duplicating enum members and values,  Up: Enum HOWTO

9.6.1 Programmatic access to enumeration members and their attributes
---------------------------------------------------------------------

Sometimes it’s useful to access members in enumerations programmatically
(i.e.  situations where ‘Color.RED’ won’t do because the exact color is
not known at program-writing time).  ‘Enum’ allows such access:

     >>> Color(1)
     <Color.RED: 1>
     >>> Color(3)
     <Color.BLUE: 3>

If you want to access enum members by 'name', use item access:

     >>> Color['RED']
     <Color.RED: 1>
     >>> Color['GREEN']
     <Color.GREEN: 2>

If you have an enum member and need its ‘name’ or ‘value’:

     >>> member = Color.RED
     >>> member.name
     'RED'
     >>> member.value
     1


File: python.info,  Node: Duplicating enum members and values,  Next: Ensuring unique enumeration values,  Prev: Programmatic access to enumeration members and their attributes,  Up: Enum HOWTO

9.6.2 Duplicating enum members and values
-----------------------------------------

Having two enum members with the same name is invalid:

     >>> class Shape(Enum):
     ...     SQUARE = 2
     ...     SQUARE = 3
     ...
     Traceback (most recent call last):
     ...
     TypeError: 'SQUARE' already defined as 2

However, an enum member can have other names associated with it.  Given
two entries ‘A’ and ‘B’ with the same value (and ‘A’ defined first), ‘B’
is an alias for the member ‘A’.  By-value lookup of the value of ‘A’
will return the member ‘A’.  By-name lookup of ‘A’ will return the
member ‘A’.  By-name lookup of ‘B’ will also return the member ‘A’:

     >>> class Shape(Enum):
     ...     SQUARE = 2
     ...     DIAMOND = 1
     ...     CIRCLE = 3
     ...     ALIAS_FOR_SQUARE = 2
     ...
     >>> Shape.SQUARE
     <Shape.SQUARE: 2>
     >>> Shape.ALIAS_FOR_SQUARE
     <Shape.SQUARE: 2>
     >>> Shape(2)
     <Shape.SQUARE: 2>

     Nota: Attempting to create a member with the same name as an
     already defined attribute (another member, a method, etc.)  or
     attempting to create an attribute with the same name as a member is
     not allowed.


File: python.info,  Node: Ensuring unique enumeration values,  Next: Using automatic values,  Prev: Duplicating enum members and values,  Up: Enum HOWTO

9.6.3 Ensuring unique enumeration values
----------------------------------------

By default, enumerations allow multiple names as aliases for the same
value.  When this behavior isn’t desired, you can use the *note
unique(): 2a10. decorator:

     >>> from enum import Enum, unique
     >>> @unique
     ... class Mistake(Enum):
     ...     ONE = 1
     ...     TWO = 2
     ...     THREE = 3
     ...     FOUR = 3
     ...
     Traceback (most recent call last):
     ...
     ValueError: duplicate values found in <enum 'Mistake'>: FOUR -> THREE


File: python.info,  Node: Using automatic values,  Next: Iteration<2>,  Prev: Ensuring unique enumeration values,  Up: Enum HOWTO

9.6.4 Using automatic values
----------------------------

If the exact value is unimportant you can use *note auto: e9d.:

     >>> from enum import Enum, auto
     >>> class Color(Enum):
     ...     RED = auto()
     ...     BLUE = auto()
     ...     GREEN = auto()
     ...
     >>> [member.value for member in Color]
     [1, 2, 3]

The values are chosen by *note _generate_next_value_(): 2a24, which can
be overridden:

     >>> class AutoName(Enum):
     ...     @staticmethod
     ...     def _generate_next_value_(name, start, count, last_values):
     ...         return name
     ...
     >>> class Ordinal(AutoName):
     ...     NORTH = auto()
     ...     SOUTH = auto()
     ...     EAST = auto()
     ...     WEST = auto()
     ...
     >>> [member.value for member in Ordinal]
     ['NORTH', 'SOUTH', 'EAST', 'WEST']

     Nota: The *note _generate_next_value_(): 2a24. method must be
     defined before any members.


File: python.info,  Node: Iteration<2>,  Next: Comparisons<2>,  Prev: Using automatic values,  Up: Enum HOWTO

9.6.5 Iteration
---------------

Iterating over the members of an enum does not provide the aliases:

     >>> list(Shape)
     [<Shape.SQUARE: 2>, <Shape.DIAMOND: 1>, <Shape.CIRCLE: 3>]
     >>> list(Weekday)
     [<Weekday.MONDAY: 1>, <Weekday.TUESDAY: 2>, <Weekday.WEDNESDAY: 4>, <Weekday.THURSDAY: 8>, <Weekday.FRIDAY: 16>, <Weekday.SATURDAY: 32>, <Weekday.SUNDAY: 64>]

Note that the aliases ‘Shape.ALIAS_FOR_SQUARE’ and ‘Weekday.WEEKEND’
aren’t shown.

The special attribute ‘__members__’ is a read-only ordered mapping of
names to members.  It includes all names defined in the enumeration,
including the aliases:

     >>> for name, member in Shape.__members__.items():
     ...     name, member
     ...
     ('SQUARE', <Shape.SQUARE: 2>)
     ('DIAMOND', <Shape.DIAMOND: 1>)
     ('CIRCLE', <Shape.CIRCLE: 3>)
     ('ALIAS_FOR_SQUARE', <Shape.SQUARE: 2>)

The ‘__members__’ attribute can be used for detailed programmatic access
to the enumeration members.  For example, finding all the aliases:

     >>> [name for name, member in Shape.__members__.items() if member.name != name]
     ['ALIAS_FOR_SQUARE']

     Nota: Aliases for flags include values with multiple flags set,
     such as ‘3’, and no flags set, i.e.  ‘0’.


File: python.info,  Node: Comparisons<2>,  Next: Allowed members and attributes of enumerations,  Prev: Iteration<2>,  Up: Enum HOWTO

9.6.6 Comparisons
-----------------

Enumeration members are compared by identity:

     >>> Color.RED is Color.RED
     True
     >>> Color.RED is Color.BLUE
     False
     >>> Color.RED is not Color.BLUE
     True

Ordered comparisons between enumeration values are 'not' supported.
Enum members are not integers (but see *note IntEnum: 56d2. below):

     >>> Color.RED < Color.BLUE
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: '<' not supported between instances of 'Color' and 'Color'

Equality comparisons are defined though:

     >>> Color.BLUE == Color.RED
     False
     >>> Color.BLUE != Color.RED
     True
     >>> Color.BLUE == Color.BLUE
     True

Comparisons against non-enumeration values will always compare not equal
(again, *note IntEnum: edd. was explicitly designed to behave
differently, see below):

     >>> Color.BLUE == 2
     False

     Avvertimento: It is possible to reload modules – if a reloaded
     module contains enums, they will be recreated, and the new members
     may not compare identical/equal to the original members.


File: python.info,  Node: Allowed members and attributes of enumerations,  Next: Restricted Enum subclassing,  Prev: Comparisons<2>,  Up: Enum HOWTO

9.6.7 Allowed members and attributes of enumerations
----------------------------------------------------

Most of the examples above use integers for enumeration values.  Using
integers is short and handy (and provided by default by the *note
Functional API: 56d4.), but not strictly enforced.  In the vast majority
of use-cases, one doesn’t care what the actual value of an enumeration
is.  But if the value 'is' important, enumerations can have arbitrary
values.

Enumerations are Python classes, and can have methods and special
methods as usual.  If we have this enumeration:

     >>> class Mood(Enum):
     ...     FUNKY = 1
     ...     HAPPY = 3
     ...
     ...     def describe(self):
     ...         # self is the member here
     ...         return self.name, self.value
     ...
     ...     def __str__(self):
     ...         return 'my custom str! {0}'.format(self.value)
     ...
     ...     @classmethod
     ...     def favorite_mood(cls):
     ...         # cls here is the enumeration
     ...         return cls.HAPPY
     ...

Then:

     >>> Mood.favorite_mood()
     <Mood.HAPPY: 3>
     >>> Mood.HAPPY.describe()
     ('HAPPY', 3)
     >>> str(Mood.FUNKY)
     'my custom str! 1'

The rules for what is allowed are as follows: names that start and end
with a single underscore are reserved by enum and cannot be used; all
other attributes defined within an enumeration will become members of
this enumeration, with the exception of special methods (*note
__str__(): 831, *note __add__(): 23c3, etc.), descriptors (methods are
also descriptors), and variable names listed in *note _ignore_: 2a22.

Note: if your enumeration defines *note __new__(): 7a1. and/or *note
__init__(): 8c0, any value(s) given to the enum member will be passed
into those methods.  See *note Planet: 56d5. for an example.

     Nota: The *note __new__(): 7a1. method, if defined, is used during
     creation of the Enum members; it is then replaced by Enum’s *note
     __new__(): 7a1. which is used after class creation for lookup of
     existing members.  See *note When to use __new__() vs.  __init__():
     56d6. for more details.


File: python.info,  Node: Restricted Enum subclassing,  Next: Dataclass support,  Prev: Allowed members and attributes of enumerations,  Up: Enum HOWTO

9.6.8 Restricted Enum subclassing
---------------------------------

A new *note Enum: 843. class must have one base enum class, up to one
concrete data type, and as many *note object: c80.-based mixin classes
as needed.  The order of these base classes is:

     class EnumName([mix-in, ...,] [data-type,] base-enum):
         pass

Also, subclassing an enumeration is allowed only if the enumeration does
not define any members.  So this is forbidden:

     >>> class MoreColor(Color):
     ...     PINK = 17
     ...
     Traceback (most recent call last):
     ...
     TypeError: <enum 'MoreColor'> cannot extend <enum 'Color'>

But this is allowed:

     >>> class Foo(Enum):
     ...     def some_behavior(self):
     ...         pass
     ...
     >>> class Bar(Foo):
     ...     HAPPY = 1
     ...     SAD = 2
     ...

Allowing subclassing of enums that define members would lead to a
violation of some important invariants of types and instances.  On the
other hand, it makes sense to allow sharing some common behavior between
a group of enumerations.  (See *note OrderedEnum: 56d8. for an example.)


File: python.info,  Node: Dataclass support,  Next: Pickling,  Prev: Restricted Enum subclassing,  Up: Enum HOWTO

9.6.9 Dataclass support
-----------------------

When inheriting from a *note dataclass: 4e2, the *note __repr__(): 1ae2.
omits the inherited class” name.  For example:

     >>> from dataclasses import dataclass, field
     >>> @dataclass
     ... class CreatureDataMixin:
     ...     size: str
     ...     legs: int
     ...     tail: bool = field(repr=False, default=True)
     ...
     >>> class Creature(CreatureDataMixin, Enum):
     ...     BEETLE = 'small', 6
     ...     DOG = 'medium', 4
     ...
     >>> Creature.DOG
     <Creature.DOG: size='medium', legs=4>

Use the *note dataclass(): 4e2. argument ‘repr=False’ to use the
standard *note repr(): 1c1.

Cambiato nella versione 3.12: Only the dataclass fields are shown in the
value area, not the dataclass” name.

     Nota: Adding *note dataclass(): 4e2. decorator to *note Enum: 843.
     and its subclasses is not supported.  It will not raise any errors,
     but it will produce very strange results at runtime, such as
     members being equal to each other:

          >>> @dataclass               # don't do this: it does not make any sense
          ... class Color(Enum):
          ...    RED = 1
          ...    BLUE = 2
          ...
          >>> Color.RED is Color.BLUE
          False
          >>> Color.RED == Color.BLUE  # problem is here: they should not be equal
          True


File: python.info,  Node: Pickling,  Next: Functional API<3>,  Prev: Dataclass support,  Up: Enum HOWTO

9.6.10 Pickling
---------------

Enumerations can be pickled and unpickled:

     >>> from test.test_enum import Fruit
     >>> from pickle import dumps, loads
     >>> Fruit.TOMATO is loads(dumps(Fruit.TOMATO))
     True

The usual restrictions for pickling apply: picklable enums must be
defined in the top level of a module, since unpickling requires them to
be importable from that module.

     Nota: With pickle protocol version 4 it is possible to easily
     pickle enums nested in other classes.

It is possible to modify how enum members are pickled/unpickled by
defining *note __reduce_ex__(): 1953. in the enumeration class.  The
default method is by-value, but enums with complicated values may want
to use by-name:

     >>> import enum
     >>> class MyEnum(enum.Enum):
     ...     __reduce_ex__ = enum.pickle_by_enum_name

     Nota: Using by-name for flags is not recommended, as unnamed
     aliases will not unpickle.


File: python.info,  Node: Functional API<3>,  Next: Derived Enumerations,  Prev: Pickling,  Up: Enum HOWTO

9.6.11 Functional API
---------------------

The *note Enum: 843. class is callable, providing the following
functional API:

     >>> Animal = Enum('Animal', 'ANT BEE CAT DOG')
     >>> Animal
     <enum 'Animal'>
     >>> Animal.ANT
     <Animal.ANT: 1>
     >>> list(Animal)
     [<Animal.ANT: 1>, <Animal.BEE: 2>, <Animal.CAT: 3>, <Animal.DOG: 4>]

The semantics of this API resemble *note namedtuple: 4e1.  The first
argument of the call to *note Enum: 843. is the name of the enumeration.

The second argument is the 'source' of enumeration member names.  It can
be a whitespace-separated string of names, a sequence of names, a
sequence of 2-tuples with key/value pairs, or a mapping (e.g.
dictionary) of names to values.  The last two options enable assigning
arbitrary values to enumerations; the others auto-assign increasing
integers starting with 1 (use the ‘start’ parameter to specify a
different starting value).  A new class derived from *note Enum: 843. is
returned.  In other words, the above assignment to ‘Animal’ is
equivalent to:

     >>> class Animal(Enum):
     ...     ANT = 1
     ...     BEE = 2
     ...     CAT = 3
     ...     DOG = 4
     ...

The reason for defaulting to ‘1’ as the starting number and not ‘0’ is
that ‘0’ is ‘False’ in a boolean sense, but by default enum members all
evaluate to ‘True’.

Pickling enums created with the functional API can be tricky as frame
stack implementation details are used to try and figure out which module
the enumeration is being created in (e.g.  it will fail if you use a
utility function in a separate module, and also may not work on
IronPython or Jython).  The solution is to specify the module name
explicitly as follows:

     >>> Animal = Enum('Animal', 'ANT BEE CAT DOG', module=__name__)

     Avvertimento: If ‘module’ is not supplied, and Enum cannot
     determine what it is, the new Enum members will not be unpicklable;
     to keep errors closer to the source, pickling will be disabled.

The new pickle protocol 4 also, in some circumstances, relies on *note
__qualname__: 235a. being set to the location where pickle will be able
to find the class.  For example, if the class was made available in
class SomeData in the global scope:

     >>> Animal = Enum('Animal', 'ANT BEE CAT DOG', qualname='SomeData.Animal')

The complete signature is:

     Enum(
         value='NewEnumName',
         names=<...>,
         *,
         module='...',
         qualname='...',
         type=<mixed-in class>,
         start=1,
         )

   * 'value': What the new enum class will record as its name.

   * 'names': The enum members.  This can be a whitespace- or
     comma-separated string (values will start at 1 unless otherwise
     specified):

          'RED GREEN BLUE' | 'RED,GREEN,BLUE' | 'RED, GREEN, BLUE'

     or an iterator of names:

          ['RED', 'GREEN', 'BLUE']

     or an iterator of (name, value) pairs:

          [('CYAN', 4), ('MAGENTA', 5), ('YELLOW', 6)]

     or a mapping:

          {'CHARTREUSE': 7, 'SEA_GREEN': 11, 'ROSEMARY': 42}

   * 'module': name of module where new enum class can be found.

   * 'qualname': where in module new enum class can be found.

   * 'type': type to mix in to new enum class.

   * 'start': number to start counting at if only names are passed in.

Cambiato nella versione 3.5: The 'start' parameter was added.


File: python.info,  Node: Derived Enumerations,  Next: When to use __new__ vs __init__,  Prev: Functional API<3>,  Up: Enum HOWTO

9.6.12 Derived Enumerations
---------------------------

* Menu:

* IntEnum::
* StrEnum::
* IntFlag::
* Flag::
* Others::


File: python.info,  Node: IntEnum,  Next: StrEnum,  Up: Derived Enumerations

9.6.12.1 IntEnum
................

The first variation of *note Enum: 843. that is provided is also a
subclass of *note int: 19b.  Members of an *note IntEnum: edd. can be
compared to integers; by extension, integer enumerations of different
types can also be compared to each other:

     >>> from enum import IntEnum
     >>> class Shape(IntEnum):
     ...     CIRCLE = 1
     ...     SQUARE = 2
     ...
     >>> class Request(IntEnum):
     ...     POST = 1
     ...     GET = 2
     ...
     >>> Shape == 1
     False
     >>> Shape.CIRCLE == 1
     True
     >>> Shape.CIRCLE == Request.POST
     True

However, they still can’t be compared to standard *note Enum: 843.
enumerations:

     >>> class Shape(IntEnum):
     ...     CIRCLE = 1
     ...     SQUARE = 2
     ...
     >>> class Color(Enum):
     ...     RED = 1
     ...     GREEN = 2
     ...
     >>> Shape.CIRCLE == Color.RED
     False

*note IntEnum: edd. values behave like integers in other ways you’d
expect:

     >>> int(Shape.CIRCLE)
     1
     >>> ['a', 'b', 'c'][Shape.CIRCLE]
     'b'
     >>> [i for i in range(Shape.SQUARE)]
     [0, 1]


File: python.info,  Node: StrEnum,  Next: IntFlag,  Prev: IntEnum,  Up: Derived Enumerations

9.6.12.2 StrEnum
................

The second variation of *note Enum: 843. that is provided is also a
subclass of *note str: 169.  Members of a *note StrEnum: 82e. can be
compared to strings; by extension, string enumerations of different
types can also be compared to each other.

Added in version 3.11.


File: python.info,  Node: IntFlag,  Next: Flag,  Prev: StrEnum,  Up: Derived Enumerations

9.6.12.3 IntFlag
................

The next variation of *note Enum: 843. provided, *note IntFlag: e9c, is
also based on *note int: 19b.  The difference being *note IntFlag: e9c.
members can be combined using the bitwise operators (&, |, ^, ~) and the
result is still an *note IntFlag: e9c. member, if possible.  Like *note
IntEnum: edd, *note IntFlag: e9c. members are also integers and can be
used wherever an *note int: 19b. is used.

     Nota: Any operation on an *note IntFlag: e9c. member besides the
     bit-wise operations will lose the *note IntFlag: e9c. membership.

     Bit-wise operations that result in invalid *note IntFlag: e9c.
     values will lose the *note IntFlag: e9c. membership.  See *note
     FlagBoundary: 837. for details.

Added in version 3.6.

Cambiato nella versione 3.11.

Sample *note IntFlag: e9c. class:

     >>> from enum import IntFlag
     >>> class Perm(IntFlag):
     ...     R = 4
     ...     W = 2
     ...     X = 1
     ...
     >>> Perm.R | Perm.W
     <Perm.R|W: 6>
     >>> Perm.R + Perm.W
     6
     >>> RW = Perm.R | Perm.W
     >>> Perm.R in RW
     True

It is also possible to name the combinations:

     >>> class Perm(IntFlag):
     ...     R = 4
     ...     W = 2
     ...     X = 1
     ...     RWX = 7
     ...
     >>> Perm.RWX
     <Perm.RWX: 7>
     >>> ~Perm.RWX
     <Perm: 0>
     >>> Perm(7)
     <Perm.RWX: 7>

     Nota: Named combinations are considered aliases.  Aliases do not
     show up during iteration, but can be returned from by-value
     lookups.

Cambiato nella versione 3.11.

Another important difference between *note IntFlag: e9c. and *note Enum:
843. is that if no flags are set (the value is 0), its boolean
evaluation is *note False: d2d.:

     >>> Perm.R & Perm.X
     <Perm: 0>
     >>> bool(Perm.R & Perm.X)
     False

Because *note IntFlag: e9c. members are also subclasses of *note int:
19b. they can be combined with them (but may lose *note IntFlag: e9c.
membership:

     >>> Perm.X | 4
     <Perm.R|X: 5>

     >>> Perm.X + 8
     9

     Nota: The negation operator, ‘~’, always returns an *note IntFlag:
     e9c. member with a positive value:

          >>> (~Perm.X).value == (Perm.R|Perm.W).value == 6
          True

*note IntFlag: e9c. members can also be iterated over:

     >>> list(RW)
     [<Perm.R: 4>, <Perm.W: 2>]

Added in version 3.11.


File: python.info,  Node: Flag,  Next: Others,  Prev: IntFlag,  Up: Derived Enumerations

9.6.12.4 Flag
.............

The last variation is *note Flag: 836.  Like *note IntFlag: e9c, *note
Flag: 836. members can be combined using the bitwise operators (&, |, ^,
~).  Unlike *note IntFlag: e9c, they cannot be combined with, nor
compared against, any other *note Flag: 836. enumeration, nor *note int:
19b.  While it is possible to specify the values directly it is
recommended to use *note auto: e9d. as the value and let *note Flag:
836. select an appropriate value.

Added in version 3.6.

Like *note IntFlag: e9c, if a combination of *note Flag: 836. members
results in no flags being set, the boolean evaluation is *note False:
d2d.:

     >>> from enum import Flag, auto
     >>> class Color(Flag):
     ...     RED = auto()
     ...     BLUE = auto()
     ...     GREEN = auto()
     ...
     >>> Color.RED & Color.GREEN
     <Color: 0>
     >>> bool(Color.RED & Color.GREEN)
     False

Individual flags should have values that are powers of two (1, 2, 4, 8,
…), while combinations of flags will not:

     >>> class Color(Flag):
     ...     RED = auto()
     ...     BLUE = auto()
     ...     GREEN = auto()
     ...     WHITE = RED | BLUE | GREEN
     ...
     >>> Color.WHITE
     <Color.WHITE: 7>

Giving a name to the «no flags set» condition does not change its
boolean value:

     >>> class Color(Flag):
     ...     BLACK = 0
     ...     RED = auto()
     ...     BLUE = auto()
     ...     GREEN = auto()
     ...
     >>> Color.BLACK
     <Color.BLACK: 0>
     >>> bool(Color.BLACK)
     False

*note Flag: 836. members can also be iterated over:

     >>> purple = Color.RED | Color.BLUE
     >>> list(purple)
     [<Color.RED: 1>, <Color.BLUE: 2>]

Added in version 3.11.

     Nota: For the majority of new code, *note Enum: 843. and *note
     Flag: 836. are strongly recommended, since *note IntEnum: edd. and
     *note IntFlag: e9c. break some semantic promises of an enumeration
     (by being comparable to integers, and thus by transitivity to other
     unrelated enumerations).  *note IntEnum: edd. and *note IntFlag:
     e9c. should be used only in cases where *note Enum: 843. and *note
     Flag: 836. will not do; for example, when integer constants are
     replaced with enumerations, or for interoperability with other
     systems.


File: python.info,  Node: Others,  Prev: Flag,  Up: Derived Enumerations

9.6.12.5 Others
...............

While *note IntEnum: edd. is part of the *note enum: 5a. module, it
would be very simple to implement independently:

     class IntEnum(int, ReprEnum):   # or Enum instead of ReprEnum
         pass

This demonstrates how similar derived enumerations can be defined; for
example a ‘FloatEnum’ that mixes in *note float: 196. instead of *note
int: 19b.

Some rules:

  1. When subclassing *note Enum: 843, mix-in types must appear before
     the *note Enum: 843. class itself in the sequence of bases, as in
     the *note IntEnum: edd. example above.

  2. Mix-in types must be subclassable.  For example, *note bool: 3c3.
     and *note range: b3f. are not subclassable and will throw an error
     during Enum creation if used as the mix-in type.

  3. While *note Enum: 843. can have members of any type, once you mix
     in an additional type, all the members must have values of that
     type, e.g.  *note int: 19b. above.  This restriction does not apply
     to mix-ins which only add methods and don’t specify another type.

  4. When another data type is mixed in, the *note value: 2a1d.
     attribute is 'not the same' as the enum member itself, although it
     is equivalent and will compare equal.

  5. A ‘data type’ is a mixin that defines *note __new__(): 7a1, or a
     *note dataclass: 4e2.

  6. %-style formatting: ‘%s’ and ‘%r’ call the *note Enum: 843. class’s
     *note __str__(): 831. and *note __repr__(): 830. respectively;
     other codes (such as ‘%i’ or ‘%h’ for IntEnum) treat the enum
     member as its mixed-in type.

  7. *note Formatted string literals: 19a, *note str.format(): 834, and
     *note format(): 199. will use the enum’s *note __str__(): 831.
     method.

     Nota: Because *note IntEnum: edd, *note IntFlag: e9c, and *note
     StrEnum: 82e. are designed to be drop-in replacements for existing
     constants, their *note __str__(): 831. method has been reset to
     their data types” *note __str__(): 831. method.


File: python.info,  Node: When to use __new__ vs __init__,  Next: How are Enums and Flags different?,  Prev: Derived Enumerations,  Up: Enum HOWTO

9.6.13 When to use ‘__new__()’ vs. ‘__init__()’
-----------------------------------------------

*note __new__(): 7a1. must be used whenever you want to customize the
actual value of the *note Enum: 843. member.  Any other modifications
may go in either *note __new__(): 7a1. or *note __init__(): 8c0, with
*note __init__(): 8c0. being preferred.

For example, if you want to pass several items to the constructor, but
only want one of them to be the value:

     >>> class Coordinate(bytes, Enum):
     ...     """
     ...     Coordinate with binary codes that can be indexed by the int code.
     ...     """
     ...     def __new__(cls, value, label, unit):
     ...         obj = bytes.__new__(cls, [value])
     ...         obj._value_ = value
     ...         obj.label = label
     ...         obj.unit = unit
     ...         return obj
     ...     PX = (0, 'P.X', 'km')
     ...     PY = (1, 'P.Y', 'km')
     ...     VX = (2, 'V.X', 'km/s')
     ...     VY = (3, 'V.Y', 'km/s')
     ...

     >>> print(Coordinate['PY'])
     Coordinate.PY

     >>> print(Coordinate(3))
     Coordinate.VY

     Avvertimento: 'Do not' call ‘super().__new__()’, as the lookup-only
     ‘__new__’ is the one that is found; instead, use the data type
     directly.

* Menu:

* Finer Points::


File: python.info,  Node: Finer Points,  Up: When to use __new__ vs __init__

9.6.13.1 Finer Points
.....................

* Menu:

* Supported __dunder__ names: Supported __dunder__ names<2>.
* Supported _sunder_ names: Supported _sunder_ names<2>.
* _Private__names::
* Enum member type::
* Creating members that are mixed with other data types::
* Boolean value of Enum classes and members::
* Enum classes with methods::
* Combining members of Flag::
* Flag and IntFlag minutia::


File: python.info,  Node: Supported __dunder__ names<2>,  Next: Supported _sunder_ names<2>,  Up: Finer Points

9.6.13.2 Supported ‘__dunder__’ names
.....................................

*note __members__: 2a1a. is a read-only ordered mapping of
‘member_name’:‘member’ items.  It is only available on the class.

*note __new__(): 7a1, if specified, must create and return the enum
members; it is also a very good idea to set the member’s *note _value_:
2a20. appropriately.  Once all the members are created it is no longer
used.


File: python.info,  Node: Supported _sunder_ names<2>,  Next: _Private__names,  Prev: Supported __dunder__ names<2>,  Up: Finer Points

9.6.13.3 Supported ‘_sunder_’ names
...................................

   - *note _name_: 2a1f. – name of the member

   - *note _value_: 2a20. – value of the member; can be set in ‘__new__’

   - *note _missing_(): 2a27. – a lookup function used when a value is
     not found; may be overridden

   - *note _ignore_: 2a22. – a list of names, either as a *note list:
     24d. or a *note str: 169, that will not be transformed into
     members, and will be removed from the final class

   - *note _generate_next_value_(): 2a24. – used to get an appropriate
     value for an enum member; may be overridden

   - *note _add_alias_(): 2a28. – adds a new name as an alias to an
     existing member.

   - *note _add_value_alias_(): 2a29. – adds a new value as an alias to
     an existing member.  See *note MultiValueEnum: 56e4. for an
     example.

          Nota: For standard *note Enum: 843. classes the next value
          chosen is the highest value seen incremented by one.

          For *note Flag: 836. classes the next value chosen will be the
          next highest power-of-two.

     Cambiato nella versione 3.13: Prior versions would use the last
     seen value instead of the highest value.

Added in version 3.6: ‘_missing_’, ‘_order_’, ‘_generate_next_value_’

Added in version 3.7: ‘_ignore_’

Added in version 3.13: ‘_add_alias_’, ‘_add_value_alias_’

To help keep Python 2 / Python 3 code in sync an *note _order_: 2a21.
attribute can be provided.  It will be checked against the actual order
of the enumeration and raise an error if the two do not match:

     >>> class Color(Enum):
     ...     _order_ = 'RED GREEN BLUE'
     ...     RED = 1
     ...     BLUE = 3
     ...     GREEN = 2
     ...
     Traceback (most recent call last):
     ...
     TypeError: member order does not match _order_:
       ['RED', 'BLUE', 'GREEN']
       ['RED', 'GREEN', 'BLUE']

     Nota: In Python 2 code the *note _order_: 2a21. attribute is
     necessary as definition order is lost before it can be recorded.


File: python.info,  Node: _Private__names,  Next: Enum member type,  Prev: Supported _sunder_ names<2>,  Up: Finer Points

9.6.13.4 _Private__names
........................

*note Private names: 208d. are not converted to enum members, but remain
normal attributes.

Cambiato nella versione 3.11.


File: python.info,  Node: Enum member type,  Next: Creating members that are mixed with other data types,  Prev: _Private__names,  Up: Finer Points

9.6.13.5 ‘Enum’ member type
...........................

Enum members are instances of their enum class, and are normally
accessed as ‘EnumClass.member’.  In certain situations, such as writing
custom enum behavior, being able to access one member directly from
another is useful, and is supported; however, in order to avoid name
clashes between member names and attributes/methods from mixed-in
classes, upper-case names are strongly recommended.

Cambiato nella versione 3.5.


File: python.info,  Node: Creating members that are mixed with other data types,  Next: Boolean value of Enum classes and members,  Prev: Enum member type,  Up: Finer Points

9.6.13.6 Creating members that are mixed with other data types
..............................................................

When subclassing other data types, such as *note int: 19b. or *note str:
169, with an *note Enum: 843, all values after the ‘=’ are passed to
that data type’s constructor.  For example:

     >>> class MyEnum(IntEnum):      # help(int) -> int(x, base=10) -> integer
     ...     example = '11', 16      # so x='11' and base=16
     ...
     >>> MyEnum.example.value        # and hex(11) is...
     17


File: python.info,  Node: Boolean value of Enum classes and members,  Next: Enum classes with methods,  Prev: Creating members that are mixed with other data types,  Up: Finer Points

9.6.13.7 Boolean value of ‘Enum’ classes and members
....................................................

Enum classes that are mixed with non-*note Enum: 843. types (such as
*note int: 19b, *note str: 169, etc.)  are evaluated according to the
mixed-in type’s rules; otherwise, all members evaluate as *note True:
e09.  To make your own enum’s boolean evaluation depend on the member’s
value add the following to your class:

     def __bool__(self):
         return bool(self.value)

Plain *note Enum: 843. classes always evaluate as *note True: e09.


File: python.info,  Node: Enum classes with methods,  Next: Combining members of Flag,  Prev: Boolean value of Enum classes and members,  Up: Finer Points

9.6.13.8 ‘Enum’ classes with methods
....................................

If you give your enum subclass extra methods, like the *note Planet:
56d5. class below, those methods will show up in a *note dir(): 845. of
the member, but not of the class:

     >>> dir(Planet)
     ['EARTH', 'JUPITER', 'MARS', 'MERCURY', 'NEPTUNE', 'SATURN', 'URANUS', 'VENUS', '__class__', '__doc__', '__members__', '__module__']
     >>> dir(Planet.EARTH)
     ['__class__', '__doc__', '__module__', 'mass', 'name', 'radius', 'surface_gravity', 'value']


File: python.info,  Node: Combining members of Flag,  Next: Flag and IntFlag minutia,  Prev: Enum classes with methods,  Up: Finer Points

9.6.13.9 Combining members of ‘Flag’
....................................

Iterating over a combination of *note Flag: 836. members will only
return the members that are comprised of a single bit:

     >>> class Color(Flag):
     ...     RED = auto()
     ...     GREEN = auto()
     ...     BLUE = auto()
     ...     MAGENTA = RED | BLUE
     ...     YELLOW = RED | GREEN
     ...     CYAN = GREEN | BLUE
     ...
     >>> Color(3)  # named combination
     <Color.YELLOW: 3>
     >>> Color(7)      # not named combination
     <Color.RED|GREEN|BLUE: 7>


File: python.info,  Node: Flag and IntFlag minutia,  Prev: Combining members of Flag,  Up: Finer Points

9.6.13.10 ‘Flag’ and ‘IntFlag’ minutia
......................................

Using the following snippet for our examples:

     >>> class Color(IntFlag):
     ...     BLACK = 0
     ...     RED = 1
     ...     GREEN = 2
     ...     BLUE = 4
     ...     PURPLE = RED | BLUE
     ...     WHITE = RED | GREEN | BLUE
     ...

the following are true:

   - single-bit flags are canonical

   - multi-bit and zero-bit flags are aliases

   - only canonical flags are returned during iteration:

          >>> list(Color.WHITE)
          [<Color.RED: 1>, <Color.GREEN: 2>, <Color.BLUE: 4>]

   - negating a flag or flag set returns a new flag/flag set with the
     corresponding positive integer value:

          >>> Color.BLUE
          <Color.BLUE: 4>

          >>> ~Color.BLUE
          <Color.RED|GREEN: 3>

   - names of pseudo-flags are constructed from their members” names:

          >>> (Color.RED | Color.GREEN).name
          'RED|GREEN'

          >>> class Perm(IntFlag):
          ...     R = 4
          ...     W = 2
          ...     X = 1
          ...
          >>> (Perm.R & Perm.W).name is None  # effectively Perm(0)
          True

   - multi-bit flags, aka aliases, can be returned from operations:

          >>> Color.RED | Color.BLUE
          <Color.PURPLE: 5>

          >>> Color(7)  # or Color(-1)
          <Color.WHITE: 7>

          >>> Color(0)
          <Color.BLACK: 0>

   - membership / containment checking: zero-valued flags are always
     considered to be contained:

          >>> Color.BLACK in Color.WHITE
          True

     otherwise, only if all bits of one flag are in the other flag will
     True be returned:

          >>> Color.PURPLE in Color.WHITE
          True

          >>> Color.GREEN in Color.PURPLE
          False

There is a new boundary mechanism that controls how out-of-range /
invalid bits are handled: ‘STRICT’, ‘CONFORM’, ‘EJECT’, and ‘KEEP’:

   * STRICT –> raises an exception when presented with invalid values

   * CONFORM –> discards any invalid bits

   * EJECT –> lose Flag status and become a normal int with the given
     value

   * KEEP –> keep the extra bits

        - keeps Flag status and extra bits

        - extra bits do not show up in iteration

        - extra bits do show up in repr() and str()

The default for Flag is ‘STRICT’, the default for ‘IntFlag’ is ‘EJECT’,
and the default for ‘_convert_’ is ‘KEEP’ (see ‘ssl.Options’ for an
example of when ‘KEEP’ is needed).


File: python.info,  Node: How are Enums and Flags different?,  Next: Enum Cookbook,  Prev: When to use __new__ vs __init__,  Up: Enum HOWTO

9.6.14 How are Enums and Flags different?
-----------------------------------------

Enums have a custom metaclass that affects many aspects of both derived
*note Enum: 843. classes and their instances (members).

* Menu:

* Enum Classes::
* Flag Classes::
* Enum Members (aka instances): Enum Members aka instances.
* Flag Members::


File: python.info,  Node: Enum Classes,  Next: Flag Classes,  Up: How are Enums and Flags different?

9.6.14.1 Enum Classes
.....................

The *note EnumType: 4f8. metaclass is responsible for providing the
*note __contains__(): 15c1, *note __dir__(): 17ca, *note __iter__():
e6b. and other methods that allow one to do things with an *note Enum:
843. class that fail on a typical class, such as ‘list(Color)’ or
‘some_enum_var in Color’.  *note EnumType: 4f8. is responsible for
ensuring that various other methods on the final *note Enum: 843. class
are correct (such as *note __new__(): 7a1, *note __getnewargs__(): fd6,
*note __str__(): 831. and *note __repr__(): 830.).


File: python.info,  Node: Flag Classes,  Next: Enum Members aka instances,  Prev: Enum Classes,  Up: How are Enums and Flags different?

9.6.14.2 Flag Classes
.....................

Flags have an expanded view of aliasing: to be canonical, the value of a
flag needs to be a power-of-two value, and not a duplicate name.  So, in
addition to the *note Enum: 843. definition of alias, a flag with no
value (a.k.a.  ‘0’) or with more than one power-of-two value (e.g.  ‘3’)
is considered an alias.


File: python.info,  Node: Enum Members aka instances,  Next: Flag Members,  Prev: Flag Classes,  Up: How are Enums and Flags different?

9.6.14.3 Enum Members (aka instances)
.....................................

The most interesting thing about enum members is that they are
singletons.  *note EnumType: 4f8. creates them all while it is creating
the enum class itself, and then puts a custom *note __new__(): 7a1. in
place to ensure that no new ones are ever instantiated by returning only
the existing member instances.


File: python.info,  Node: Flag Members,  Prev: Enum Members aka instances,  Up: How are Enums and Flags different?

9.6.14.4 Flag Members
.....................

Flag members can be iterated over just like the *note Flag: 836. class,
and only the canonical members will be returned.  For example:

     >>> list(Color)
     [<Color.RED: 1>, <Color.GREEN: 2>, <Color.BLUE: 4>]

(Note that ‘BLACK’, ‘PURPLE’, and ‘WHITE’ do not show up.)

Inverting a flag member returns the corresponding positive value, rather
than a negative value — for example:

     >>> ~Color.RED
     <Color.GREEN|BLUE: 6>

Flag members have a length corresponding to the number of power-of-two
values they contain.  For example:

     >>> len(Color.PURPLE)
     2


File: python.info,  Node: Enum Cookbook,  Next: Subclassing EnumType,  Prev: How are Enums and Flags different?,  Up: Enum HOWTO

9.6.15 Enum Cookbook
--------------------

While *note Enum: 843, *note IntEnum: edd, *note StrEnum: 82e, *note
Flag: 836, and *note IntFlag: e9c. are expected to cover the majority of
use-cases, they cannot cover them all.  Here are recipes for some
different types of enumerations that can be used directly, or as
examples for creating one’s own.

* Menu:

* Omitting values::
* OrderedEnum::
* DuplicateFreeEnum::
* MultiValueEnum::
* Planet::
* TimePeriod::


File: python.info,  Node: Omitting values,  Next: OrderedEnum,  Up: Enum Cookbook

9.6.15.1 Omitting values
........................

In many use-cases, one doesn’t care what the actual value of an
enumeration is.  There are several ways to define this type of simple
enumeration:

   - use instances of *note auto: e9d. for the value

   - use instances of *note object: c80. as the value

   - use a descriptive string as the value

   - use a tuple as the value and a custom *note __new__(): 7a1. to
     replace the tuple with an *note int: 19b. value

Using any of these methods signifies to the user that these values are
not important, and also enables one to add, remove, or reorder members
without having to renumber the remaining members.

* Menu:

* Using auto::
* Using object::
* Using a descriptive string::
* Using a custom __new__(): Using a custom __new__.


File: python.info,  Node: Using auto,  Next: Using object,  Up: Omitting values

9.6.15.2 Using ‘auto’
.....................

Using *note auto: e9d. would look like:

     >>> class Color(Enum):
     ...     RED = auto()
     ...     BLUE = auto()
     ...     GREEN = auto()
     ...
     >>> Color.GREEN
     <Color.GREEN: 3>


File: python.info,  Node: Using object,  Next: Using a descriptive string,  Prev: Using auto,  Up: Omitting values

9.6.15.3 Using ‘object’
.......................

Using *note object: c80. would look like:

     >>> class Color(Enum):
     ...     RED = object()
     ...     GREEN = object()
     ...     BLUE = object()
     ...
     >>> Color.GREEN
     <Color.GREEN: <object object at 0x...>>

This is also a good example of why you might want to write your own
*note __repr__(): 830.:

     >>> class Color(Enum):
     ...     RED = object()
     ...     GREEN = object()
     ...     BLUE = object()
     ...     def __repr__(self):
     ...         return "<%s.%s>" % (self.__class__.__name__, self._name_)
     ...
     >>> Color.GREEN
     <Color.GREEN>


File: python.info,  Node: Using a descriptive string,  Next: Using a custom __new__,  Prev: Using object,  Up: Omitting values

9.6.15.4 Using a descriptive string
...................................

Using a string as the value would look like:

     >>> class Color(Enum):
     ...     RED = 'stop'
     ...     GREEN = 'go'
     ...     BLUE = 'too fast!'
     ...
     >>> Color.GREEN
     <Color.GREEN: 'go'>


File: python.info,  Node: Using a custom __new__,  Prev: Using a descriptive string,  Up: Omitting values

9.6.15.5 Using a custom ‘__new__()’
...................................

Using an auto-numbering *note __new__(): 7a1. would look like:

     >>> class AutoNumber(Enum):
     ...     def __new__(cls):
     ...         value = len(cls.__members__) + 1
     ...         obj = object.__new__(cls)
     ...         obj._value_ = value
     ...         return obj
     ...
     >>> class Color(AutoNumber):
     ...     RED = ()
     ...     GREEN = ()
     ...     BLUE = ()
     ...
     >>> Color.GREEN
     <Color.GREEN: 2>

To make a more general purpose ‘AutoNumber’, add ‘*args’ to the
signature:

     >>> class AutoNumber(Enum):
     ...     def __new__(cls, *args):      # this is the only change from above
     ...         value = len(cls.__members__) + 1
     ...         obj = object.__new__(cls)
     ...         obj._value_ = value
     ...         return obj
     ...

Then when you inherit from ‘AutoNumber’ you can write your own
‘__init__’ to handle any extra arguments:

     >>> class Swatch(AutoNumber):
     ...     def __init__(self, pantone='unknown'):
     ...         self.pantone = pantone
     ...     AUBURN = '3497'
     ...     SEA_GREEN = '1246'
     ...     BLEACHED_CORAL = () # New color, no Pantone code yet!
     ...
     >>> Swatch.SEA_GREEN
     <Swatch.SEA_GREEN: 2>
     >>> Swatch.SEA_GREEN.pantone
     '1246'
     >>> Swatch.BLEACHED_CORAL.pantone
     'unknown'

     Nota: The *note __new__(): 7a1. method, if defined, is used during
     creation of the Enum members; it is then replaced by Enum’s *note
     __new__(): 7a1. which is used after class creation for lookup of
     existing members.

     Avvertimento: 'Do not' call ‘super().__new__()’, as the lookup-only
     ‘__new__’ is the one that is found; instead, use the data type
     directly – e.g.:

          obj = int.__new__(cls, value)


File: python.info,  Node: OrderedEnum,  Next: DuplicateFreeEnum,  Prev: Omitting values,  Up: Enum Cookbook

9.6.15.6 OrderedEnum
....................

An ordered enumeration that is not based on *note IntEnum: edd. and so
maintains the normal *note Enum: 843. invariants (such as not being
comparable to other enumerations):

     >>> class OrderedEnum(Enum):
     ...     def __ge__(self, other):
     ...         if self.__class__ is other.__class__:
     ...             return self.value >= other.value
     ...         return NotImplemented
     ...     def __gt__(self, other):
     ...         if self.__class__ is other.__class__:
     ...             return self.value > other.value
     ...         return NotImplemented
     ...     def __le__(self, other):
     ...         if self.__class__ is other.__class__:
     ...             return self.value <= other.value
     ...         return NotImplemented
     ...     def __lt__(self, other):
     ...         if self.__class__ is other.__class__:
     ...             return self.value < other.value
     ...         return NotImplemented
     ...
     >>> class Grade(OrderedEnum):
     ...     A = 5
     ...     B = 4
     ...     C = 3
     ...     D = 2
     ...     F = 1
     ...
     >>> Grade.C < Grade.A
     True


File: python.info,  Node: DuplicateFreeEnum,  Next: MultiValueEnum,  Prev: OrderedEnum,  Up: Enum Cookbook

9.6.15.7 DuplicateFreeEnum
..........................

Raises an error if a duplicate member value is found instead of creating
an alias:

     >>> class DuplicateFreeEnum(Enum):
     ...     def __init__(self, *args):
     ...         cls = self.__class__
     ...         if any(self.value == e.value for e in cls):
     ...             a = self.name
     ...             e = cls(self.value).name
     ...             raise ValueError(
     ...                 "aliases not allowed in DuplicateFreeEnum:  %r --> %r"
     ...                 % (a, e))
     ...
     >>> class Color(DuplicateFreeEnum):
     ...     RED = 1
     ...     GREEN = 2
     ...     BLUE = 3
     ...     GRENE = 2
     ...
     Traceback (most recent call last):
       ...
     ValueError: aliases not allowed in DuplicateFreeEnum:  'GRENE' --> 'GREEN'

     Nota: This is a useful example for subclassing Enum to add or
     change other behaviors as well as disallowing aliases.  If the only
     desired change is disallowing aliases, the *note unique(): 2a10.
     decorator can be used instead.


File: python.info,  Node: MultiValueEnum,  Next: Planet,  Prev: DuplicateFreeEnum,  Up: Enum Cookbook

9.6.15.8 MultiValueEnum
.......................

Supports having more than one value per member:

     >>> class MultiValueEnum(Enum):
     ...     def __new__(cls, value, *values):
     ...         self = object.__new__(cls)
     ...         self._value_ = value
     ...         for v in values:
     ...             self._add_value_alias_(v)
     ...         return self
     ...
     >>> class DType(MultiValueEnum):
     ...     float32 = 'f', 8
     ...     double64 = 'd', 9
     ...
     >>> DType('f')
     <DType.float32: 'f'>
     >>> DType(9)
     <DType.double64: 'd'>


File: python.info,  Node: Planet,  Next: TimePeriod,  Prev: MultiValueEnum,  Up: Enum Cookbook

9.6.15.9 Planet
...............

If *note __new__(): 7a1. or *note __init__(): 8c0. is defined, the value
of the enum member will be passed to those methods:

     >>> class Planet(Enum):
     ...     MERCURY = (3.303e+23, 2.4397e6)
     ...     VENUS   = (4.869e+24, 6.0518e6)
     ...     EARTH   = (5.976e+24, 6.37814e6)
     ...     MARS    = (6.421e+23, 3.3972e6)
     ...     JUPITER = (1.9e+27,   7.1492e7)
     ...     SATURN  = (5.688e+26, 6.0268e7)
     ...     URANUS  = (8.686e+25, 2.5559e7)
     ...     NEPTUNE = (1.024e+26, 2.4746e7)
     ...     def __init__(self, mass, radius):
     ...         self.mass = mass       # in kilograms
     ...         self.radius = radius   # in meters
     ...     @property
     ...     def surface_gravity(self):
     ...         # universal gravitational constant  (m3 kg-1 s-2)
     ...         G = 6.67300E-11
     ...         return G * self.mass / (self.radius * self.radius)
     ...
     >>> Planet.EARTH.value
     (5.976e+24, 6378140.0)
     >>> Planet.EARTH.surface_gravity
     9.802652743337129


File: python.info,  Node: TimePeriod,  Prev: Planet,  Up: Enum Cookbook

9.6.15.10 TimePeriod
....................

An example to show the *note _ignore_: 2a22. attribute in use:

     >>> from datetime import timedelta
     >>> class Period(timedelta, Enum):
     ...     "different lengths of time"
     ...     _ignore_ = 'Period i'
     ...     Period = vars()
     ...     for i in range(367):
     ...         Period['day_%d' % i] = i
     ...
     >>> list(Period)[:2]
     [<Period.day_0: datetime.timedelta(0)>, <Period.day_1: datetime.timedelta(days=1)>]
     >>> list(Period)[-2:]
     [<Period.day_365: datetime.timedelta(days=365)>, <Period.day_366: datetime.timedelta(days=366)>]


File: python.info,  Node: Subclassing EnumType,  Prev: Enum Cookbook,  Up: Enum HOWTO

9.6.16 Subclassing EnumType
---------------------------

While most enum needs can be met by customizing *note Enum: 843.
subclasses, either with class decorators or custom functions, *note
EnumType: 4f8. can be subclassed to provide a different Enum experience.


File: python.info,  Node: Functional Programming HOWTO,  Next: Logging HOWTO,  Prev: Enum HOWTO,  Up: Python HOWTOs

9.7 Functional Programming HOWTO
================================


Author: A. M. Kuchling


Release: 0.32

In this document, we’ll take a tour of Python’s features suitable for
implementing programs in a functional style.  After an introduction to
the concepts of functional programming, we’ll look at language features
such as *note iterator: 4c9.s and *note generator: 1263.s and relevant
library modules such as *note itertools: 85. and *note functools: 63.

* Menu:

* Introduction: Introduction<14>.
* Iterators::
* Generator expressions and list comprehensions::
* Generators::
* Built-in functions: Built-in functions<2>.
* The itertools module::
* The functools module::
* Small functions and the lambda expression::
* Revision History and Acknowledgements::
* References: References<2>.


File: python.info,  Node: Introduction<14>,  Next: Iterators,  Up: Functional Programming HOWTO

9.7.1 Introduction
------------------

This section explains the basic concept of functional programming; if
you’re just interested in learning about Python language features, skip
to the next section on *note Iterators: 56ff.

Programming languages support decomposing problems in several different
ways:

   * Most programming languages are 'procedural': programs are lists of
     instructions that tell the computer what to do with the program’s
     input.  C, Pascal, and even Unix shells are procedural languages.

   * In 'declarative' languages, you write a specification that
     describes the problem to be solved, and the language implementation
     figures out how to perform the computation efficiently.  SQL is the
     declarative language you’re most likely to be familiar with; a SQL
     query describes the data set you want to retrieve, and the SQL
     engine decides whether to scan tables or use indexes, which
     subclauses should be performed first, etc.

   * 'Object-oriented' programs manipulate collections of objects.
     Objects have internal state and support methods that query or
     modify this internal state in some way.  Smalltalk and Java are
     object-oriented languages.  C++ and Python are languages that
     support object-oriented programming, but don’t force the use of
     object-oriented features.

   * 'Functional' programming decomposes a problem into a set of
     functions.  Ideally, functions only take inputs and produce
     outputs, and don’t have any internal state that affects the output
     produced for a given input.  Well-known functional languages
     include the ML family (Standard ML, OCaml, and other variants) and
     Haskell.

The designers of some computer languages choose to emphasize one
particular approach to programming.  This often makes it difficult to
write programs that use a different approach.  Other languages are
multi-paradigm languages that support several different approaches.
Lisp, C++, and Python are multi-paradigm; you can write programs or
libraries that are largely procedural, object-oriented, or functional in
all of these languages.  In a large program, different sections might be
written using different approaches; the GUI might be object-oriented
while the processing logic is procedural or functional, for example.

In a functional program, input flows through a set of functions.  Each
function operates on its input and produces some output.  Functional
style discourages functions with side effects that modify internal state
or make other changes that aren’t visible in the function’s return
value.  Functions that have no side effects at all are called 'purely
functional'.  Avoiding side effects means not using data structures that
get updated as a program runs; every function’s output must only depend
on its input.

Some languages are very strict about purity and don’t even have
assignment statements such as ‘a=3’ or ‘c = a + b’, but it’s difficult
to avoid all side effects, such as printing to the screen or writing to
a disk file.  Another example is a call to the *note print(): 1177. or
*note time.sleep(): 8ad. function, neither of which returns a useful
value.  Both are called only for their side effects of sending some text
to the screen or pausing execution for a second.

Python programs written in functional style usually won’t go to the
extreme of avoiding all I/O or all assignments; instead, they’ll provide
a functional-appearing interface but will use non-functional features
internally.  For example, the implementation of a function will still
use assignments to local variables, but won’t modify global variables or
have other side effects.

Functional programming can be considered the opposite of object-oriented
programming.  Objects are little capsules containing some internal state
along with a collection of method calls that let you modify this state,
and programs consist of making the right set of state changes.
Functional programming wants to avoid state changes as much as possible
and works with data flowing between functions.  In Python you might
combine the two approaches by writing functions that take and return
instances representing objects in your application (e-mail messages,
transactions, etc.).

Functional design may seem like an odd constraint to work under.  Why
should you avoid objects and side effects?  There are theoretical and
practical advantages to the functional style:

   * Formal provability.

   * Modularity.

   * Composability.

   * Ease of debugging and testing.

* Menu:

* Formal provability::
* Modularity::
* Ease of debugging and testing::
* Composability::


File: python.info,  Node: Formal provability,  Next: Modularity,  Up: Introduction<14>

9.7.1.1 Formal provability
..........................

A theoretical benefit is that it’s easier to construct a mathematical
proof that a functional program is correct.

For a long time researchers have been interested in finding ways to
mathematically prove programs correct.  This is different from testing a
program on numerous inputs and concluding that its output is usually
correct, or reading a program’s source code and concluding that the code
looks right; the goal is instead a rigorous proof that a program
produces the right result for all possible inputs.

The technique used to prove programs correct is to write down
'invariants', properties of the input data and of the program’s
variables that are always true.  For each line of code, you then show
that if invariants X and Y are true 'before' the line is executed, the
slightly different invariants X” and Y” are true 'after' the line is
executed.  This continues until you reach the end of the program, at
which point the invariants should match the desired conditions on the
program’s output.

Functional programming’s avoidance of assignments arose because
assignments are difficult to handle with this technique; assignments can
break invariants that were true before the assignment without producing
any new invariants that can be propagated onward.

Unfortunately, proving programs correct is largely impractical and not
relevant to Python software.  Even trivial programs require proofs that
are several pages long; the proof of correctness for a moderately
complicated program would be enormous, and few or none of the programs
you use daily (the Python interpreter, your XML parser, your web
browser) could be proven correct.  Even if you wrote down or generated a
proof, there would then be the question of verifying the proof; maybe
there’s an error in it, and you wrongly believe you’ve proved the
program correct.


File: python.info,  Node: Modularity,  Next: Ease of debugging and testing,  Prev: Formal provability,  Up: Introduction<14>

9.7.1.2 Modularity
..................

A more practical benefit of functional programming is that it forces you
to break apart your problem into small pieces.  Programs are more
modular as a result.  It’s easier to specify and write a small function
that does one thing than a large function that performs a complicated
transformation.  Small functions are also easier to read and to check
for errors.


File: python.info,  Node: Ease of debugging and testing,  Next: Composability,  Prev: Modularity,  Up: Introduction<14>

9.7.1.3 Ease of debugging and testing
.....................................

Testing and debugging a functional-style program is easier.

Debugging is simplified because functions are generally small and
clearly specified.  When a program doesn’t work, each function is an
interface point where you can check that the data are correct.  You can
look at the intermediate inputs and outputs to quickly isolate the
function that’s responsible for a bug.

Testing is easier because each function is a potential subject for a
unit test.  Functions don’t depend on system state that needs to be
replicated before running a test; instead you only have to synthesize
the right input and then check that the output matches expectations.


File: python.info,  Node: Composability,  Prev: Ease of debugging and testing,  Up: Introduction<14>

9.7.1.4 Composability
.....................

As you work on a functional-style program, you’ll write a number of
functions with varying inputs and outputs.  Some of these functions will
be unavoidably specialized to a particular application, but others will
be useful in a wide variety of programs.  For example, a function that
takes a directory path and returns all the XML files in the directory,
or a function that takes a filename and returns its contents, can be
applied to many different situations.

Over time you’ll form a personal library of utilities.  Often you’ll
assemble new programs by arranging existing functions in a new
configuration and writing a few functions specialized for the current
task.


File: python.info,  Node: Iterators,  Next: Generator expressions and list comprehensions,  Prev: Introduction<14>,  Up: Functional Programming HOWTO

9.7.2 Iterators
---------------

I’ll start by looking at a Python language feature that’s an important
foundation for writing functional-style programs: iterators.

An iterator is an object representing a stream of data; this object
returns the data one element at a time.  A Python iterator must support
a method called *note __next__(): 14d5. that takes no arguments and
always returns the next element of the stream.  If there are no more
elements in the stream, *note __next__(): 14d5. must raise the *note
StopIteration: df7. exception.  Iterators don’t have to be finite,
though; it’s perfectly reasonable to write an iterator that produces an
infinite stream of data.

The built-in *note iter(): 9d9. function takes an arbitrary object and
tries to return an iterator that will return the object’s contents or
elements, raising *note TypeError: 198. if the object doesn’t support
iteration.  Several of Python’s built-in data types support iteration,
the most common being lists and dictionaries.  An object is called *note
iterable: 142f. if you can get an iterator for it.

You can experiment with the iteration interface manually:

     >>> L = [1, 2, 3]
     >>> it = iter(L)
     >>> it
     <...iterator object at ...>
     >>> it.__next__()  # same as next(it)
     1
     >>> next(it)
     2
     >>> next(it)
     3
     >>> next(it)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     StopIteration
     >>>

Python expects iterable objects in several different contexts, the most
important being the *note for: 34a. statement.  In the statement ‘for X
in Y’, Y must be an iterator or some object for which *note iter(): 9d9.
can create an iterator.  These two statements are equivalent:

     for i in iter(obj):
         print(i)

     for i in obj:
         print(i)

Iterators can be materialized as lists or tuples by using the *note
list(): 24d. or *note tuple(): 614. constructor functions:

     >>> L = [1, 2, 3]
     >>> iterator = iter(L)
     >>> t = tuple(iterator)
     >>> t
     (1, 2, 3)

Sequence unpacking also supports iterators: if you know an iterator will
return N elements, you can unpack them into an N-tuple:

     >>> L = [1, 2, 3]
     >>> iterator = iter(L)
     >>> a, b, c = iterator
     >>> a, b, c
     (1, 2, 3)

Built-in functions such as *note max(): 110e. and *note min(): 110d. can
take a single iterator argument and will return the largest or smallest
element.  The ‘"in"’ and ‘"not in"’ operators also support iterators: ‘X
in iterator’ is true if X is found in the stream returned by the
iterator.  You’ll run into obvious problems if the iterator is infinite;
*note max(): 110e, *note min(): 110d. will never return, and if the
element X never appears in the stream, the ‘"in"’ and ‘"not in"’
operators won’t return either.

Note that you can only go forward in an iterator; there’s no way to get
the previous element, reset the iterator, or make a copy of it.
Iterator objects can optionally provide these additional capabilities,
but the iterator protocol only specifies the *note __next__(): 14d5.
method.  Functions may therefore consume all of the iterator’s output,
and if you need to do something different with the same stream, you’ll
have to create a new iterator.

* Menu:

* Data Types That Support Iterators::


File: python.info,  Node: Data Types That Support Iterators,  Up: Iterators

9.7.2.1 Data Types That Support Iterators
.........................................

We’ve already seen how lists and tuples support iterators.  In fact, any
Python sequence type, such as strings, will automatically support
creation of an iterator.

Calling *note iter(): 9d9. on a dictionary returns an iterator that will
loop over the dictionary’s keys:

     >>> m = {'Jan': 1, 'Feb': 2, 'Mar': 3, 'Apr': 4, 'May': 5, 'Jun': 6,
     ...      'Jul': 7, 'Aug': 8, 'Sep': 9, 'Oct': 10, 'Nov': 11, 'Dec': 12}
     >>> for key in m:
     ...     print(key, m[key])
     Jan 1
     Feb 2
     Mar 3
     Apr 4
     May 5
     Jun 6
     Jul 7
     Aug 8
     Sep 9
     Oct 10
     Nov 11
     Dec 12

Note that starting with Python 3.7, dictionary iteration order is
guaranteed to be the same as the insertion order.  In earlier versions,
the behaviour was unspecified and could vary between implementations.

Applying *note iter(): 9d9. to a dictionary always loops over the keys,
but dictionaries have methods that return other iterators.  If you want
to iterate over values or key/value pairs, you can explicitly call the
*note values(): 9d3. or *note items(): 9d4. methods to get an
appropriate iterator.

The *note dict(): 183. constructor can accept an iterator that returns a
finite stream of ‘(key, value)’ tuples:

     >>> L = [('Italy', 'Rome'), ('France', 'Paris'), ('US', 'Washington DC')]
     >>> dict(iter(L))
     {'Italy': 'Rome', 'France': 'Paris', 'US': 'Washington DC'}

Files also support iteration by calling the *note readline(): 2090.
method until there are no more lines in the file.  This means you can
read each line of a file like this:

     for line in file:
         # do something for each line
         ...

Sets can take their contents from an iterable and let you iterate over
the set’s elements:

     >>> S = {2, 3, 5, 7, 11, 13}
     >>> for i in S:
     ...     print(i)
     2
     3
     5
     7
     11
     13


File: python.info,  Node: Generator expressions and list comprehensions,  Next: Generators,  Prev: Iterators,  Up: Functional Programming HOWTO

9.7.3 Generator expressions and list comprehensions
---------------------------------------------------

Two common operations on an iterator’s output are 1) performing some
operation for every element, 2) selecting a subset of elements that meet
some condition.  For example, given a list of strings, you might want to
strip off trailing whitespace from each line or extract all the strings
containing a given substring.

List comprehensions and generator expressions (short form: «listcomps»
and «genexps») are a concise notation for such operations, borrowed from
the functional programming language Haskell
(‘https://www.haskell.org/’).  You can strip all the whitespace from a
stream of strings with the following code:

     >>> line_list = ['  line 1\n', 'line 2  \n', ' \n', '']

     >>> # Generator expression -- returns iterator
     >>> stripped_iter = (line.strip() for line in line_list)

     >>> # List comprehension -- returns list
     >>> stripped_list = [line.strip() for line in line_list]

You can select only certain elements by adding an ‘"if"’ condition:

     >>> stripped_list = [line.strip() for line in line_list
     ...                  if line != ""]

With a list comprehension, you get back a Python list; ‘stripped_list’
is a list containing the resulting lines, not an iterator.  Generator
expressions return an iterator that computes the values as necessary,
not needing to materialize all the values at once.  This means that list
comprehensions aren’t useful if you’re working with iterators that
return an infinite stream or a very large amount of data.  Generator
expressions are preferable in these situations.

Generator expressions are surrounded by parentheses («()») and list
comprehensions are surrounded by square brackets («[]»).  Generator
expressions have the form:

     ( expression for expr in sequence1
                  if condition1
                  for expr2 in sequence2
                  if condition2
                  for expr3 in sequence3
                  ...
                  if condition3
                  for exprN in sequenceN
                  if conditionN )

Again, for a list comprehension only the outside brackets are different
(square brackets instead of parentheses).

The elements of the generated output will be the successive values of
‘expression’.  The ‘if’ clauses are all optional; if present,
‘expression’ is only evaluated and added to the result when ‘condition’
is true.

Generator expressions always have to be written inside parentheses, but
the parentheses signalling a function call also count.  If you want to
create an iterator that will be immediately passed to a function you can
write:

     obj_total = sum(obj.count for obj in list_all_objects())

The ‘for...in’ clauses contain the sequences to be iterated over.  The
sequences do not have to be the same length, because they are iterated
over from left to right, 'not' in parallel.  For each element in
‘sequence1’, ‘sequence2’ is looped over from the beginning.  ‘sequence3’
is then looped over for each resulting pair of elements from ‘sequence1’
and ‘sequence2’.

To put it another way, a list comprehension or generator expression is
equivalent to the following Python code:

     for expr1 in sequence1:
         if not (condition1):
             continue   # Skip this element
         for expr2 in sequence2:
             if not (condition2):
                 continue   # Skip this element
             ...
             for exprN in sequenceN:
                 if not (conditionN):
                     continue   # Skip this element

                 # Output the value of
                 # the expression.

This means that when there are multiple ‘for...in’ clauses but no ‘if’
clauses, the length of the resulting output will be equal to the product
of the lengths of all the sequences.  If you have two lists of length 3,
the output list is 9 elements long:

     >>> seq1 = 'abc'
     >>> seq2 = (1, 2, 3)
     >>> [(x, y) for x in seq1 for y in seq2]
     [('a', 1), ('a', 2), ('a', 3),
      ('b', 1), ('b', 2), ('b', 3),
      ('c', 1), ('c', 2), ('c', 3)]

To avoid introducing an ambiguity into Python’s grammar, if ‘expression’
is creating a tuple, it must be surrounded with parentheses.  The first
list comprehension below is a syntax error, while the second one is
correct:

     # Syntax error
     [x, y for x in seq1 for y in seq2]
     # Correct
     [(x, y) for x in seq1 for y in seq2]


File: python.info,  Node: Generators,  Next: Built-in functions<2>,  Prev: Generator expressions and list comprehensions,  Up: Functional Programming HOWTO

9.7.4 Generators
----------------

Generators are a special class of functions that simplify the task of
writing iterators.  Regular functions compute a value and return it, but
generators return an iterator that returns a stream of values.

You’re doubtless familiar with how regular function calls work in Python
or C. When you call a function, it gets a private namespace where its
local variables are created.  When the function reaches a ‘return’
statement, the local variables are destroyed and the value is returned
to the caller.  A later call to the same function creates a new private
namespace and a fresh set of local variables.  But, what if the local
variables weren’t thrown away on exiting a function?  What if you could
later resume the function where it left off?  This is what generators
provide; they can be thought of as resumable functions.

Here’s the simplest example of a generator function:

     >>> def generate_ints(N):
     ...    for i in range(N):
     ...        yield i

Any function containing a *note yield: bc4. keyword is a generator
function; this is detected by Python’s *note bytecode: 4ab. compiler
which compiles the function specially as a result.

When you call a generator function, it doesn’t return a single value;
instead it returns a generator object that supports the iterator
protocol.  On executing the ‘yield’ expression, the generator outputs
the value of ‘i’, similar to a ‘return’ statement.  The big difference
between ‘yield’ and a ‘return’ statement is that on reaching a ‘yield’
the generator’s state of execution is suspended and local variables are
preserved.  On the next call to the generator’s *note __next__(): 2098.
method, the function will resume executing.

Here’s a sample usage of the ‘generate_ints()’ generator:

     >>> gen = generate_ints(3)
     >>> gen
     <generator object generate_ints at ...>
     >>> next(gen)
     0
     >>> next(gen)
     1
     >>> next(gen)
     2
     >>> next(gen)
     Traceback (most recent call last):
       File "stdin", line 1, in <module>
       File "stdin", line 2, in generate_ints
     StopIteration

You could equally write ‘for i in generate_ints(5)’, or ‘a, b, c =
generate_ints(3)’.

Inside a generator function, ‘return value’ causes
‘StopIteration(value)’ to be raised from the *note __next__(): 2098.
method.  Once this happens, or the bottom of the function is reached,
the procession of values ends and the generator cannot yield any further
values.

You could achieve the effect of generators manually by writing your own
class and storing all the local variables of the generator as instance
variables.  For example, returning a list of integers could be done by
setting ‘self.count’ to 0, and having the *note __next__(): 14d5. method
increment ‘self.count’ and return it.  However, for a moderately
complicated generator, writing a corresponding class can be much
messier.

The test suite included with Python’s library,
Lib/test/test_generators.py(1), contains a number of more interesting
examples.  Here’s one generator that implements an in-order traversal of
a tree using generators recursively.

     # A recursive generator that generates Tree leaves in in-order.
     def inorder(t):
         if t:
             for x in inorder(t.left):
                 yield x

             yield t.label

             for x in inorder(t.right):
                 yield x

Two other examples in ‘test_generators.py’ produce solutions for the
N-Queens problem (placing N queens on an NxN chess board so that no
queen threatens another) and the Knight’s Tour (finding a route that
takes a knight to every square of an NxN chessboard without visiting any
square twice).

* Menu:

* Passing values into a generator::

   ---------- Footnotes ----------

   (1) 
https://github.com/python/cpython/tree/3.14/Lib/test/test_generators.py


File: python.info,  Node: Passing values into a generator,  Up: Generators

9.7.4.1 Passing values into a generator
.......................................

In Python 2.4 and earlier, generators only produced output.  Once a
generator’s code was invoked to create an iterator, there was no way to
pass any new information into the function when its execution is
resumed.  You could hack together this ability by making the generator
look at a global variable or by passing in some mutable object that
callers then modify, but these approaches are messy.

In Python 2.5 there’s a simple way to pass values into a generator.
*note yield: bc4. became an expression, returning a value that can be
assigned to a variable or otherwise operated on:

     val = (yield i)

I recommend that you 'always' put parentheses around a ‘yield’
expression when you’re doing something with the returned value, as in
the above example.  The parentheses aren’t always necessary, but it’s
easier to always add them instead of having to remember when they’re
needed.

( PEP 342(1) explains the exact rules, which are that a
‘yield’-expression must always be parenthesized except when it occurs at
the top-level expression on the right-hand side of an assignment.  This
means you can write ‘val = yield i’ but have to use parentheses when
there’s an operation, as in ‘val = (yield i) + 12’.)

Values are sent into a generator by calling its *note send(value): 23fd.
method.  This method resumes the generator’s code and the ‘yield’
expression returns the specified value.  If the regular *note
__next__(): 2098. method is called, the ‘yield’ returns ‘None’.

Here’s a simple counter that increments by 1 and allows changing the
value of the internal counter.

     def counter(maximum):
         i = 0
         while i < maximum:
             val = (yield i)
             # If value provided, change counter
             if val is not None:
                 i = val
             else:
                 i += 1

And here’s an example of changing the counter:

     >>> it = counter(10)
     >>> next(it)
     0
     >>> next(it)
     1
     >>> it.send(8)
     8
     >>> next(it)
     9
     >>> next(it)
     Traceback (most recent call last):
       File "t.py", line 15, in <module>
         it.next()
     StopIteration

Because ‘yield’ will often be returning ‘None’, you should always check
for this case.  Don’t just use its value in expressions unless you’re
sure that the *note send(): 23fd. method will be the only method used to
resume your generator function.

In addition to *note send(): 23fd, there are two other methods on
generators:

   * *note throw(value): 71d. is used to raise an exception inside the
     generator; the exception is raised by the ‘yield’ expression where
     the generator’s execution is paused.

   * *note close(): 177b. sends a *note GeneratorExit: 15cf. exception
     to the generator to terminate the iteration.  On receiving this
     exception, the generator’s code must either raise *note
     GeneratorExit: 15cf. or *note StopIteration: df7.; catching the
     exception and doing anything else is illegal and will trigger a
     *note RuntimeError: 244.  *note close(): 177b. will also be called
     by Python’s garbage collector when the generator is
     garbage-collected.

     If you need to run cleanup code when a *note GeneratorExit: 15cf.
     occurs, I suggest using a ‘try: ... finally:’ suite instead of
     catching *note GeneratorExit: 15cf.

The cumulative effect of these changes is to turn generators from
one-way producers of information into both producers and consumers.

Generators also become 'coroutines', a more generalized form of
subroutines.  Subroutines are entered at one point and exited at another
point (the top of the function, and a ‘return’ statement), but
coroutines can be entered, exited, and resumed at many different points
(the ‘yield’ statements).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0342/


File: python.info,  Node: Built-in functions<2>,  Next: The itertools module,  Prev: Generators,  Up: Functional Programming HOWTO

9.7.5 Built-in functions
------------------------

Let’s look in more detail at built-in functions often used with
iterators.

Two of Python’s built-in functions, *note map(): 19f. and *note
filter(): a66. duplicate the features of generator expressions:

*note map(f, iterA, iterB, ...): 19f. returns an iterator over the sequence

     ‘f(iterA[0], iterB[0]), f(iterA[1], iterB[1]), f(iterA[2],
     iterB[2]), ...’.

          >>> def upper(s):
          ...     return s.upper()

          >>> list(map(upper, ['sentence', 'fragment']))
          ['SENTENCE', 'FRAGMENT']
          >>> [upper(s) for s in ['sentence', 'fragment']]
          ['SENTENCE', 'FRAGMENT']

You can of course achieve the same effect with a list comprehension.

*note filter(predicate, iter): a66. returns an iterator over all the
sequence elements that meet a certain condition, and is similarly
duplicated by list comprehensions.  A 'predicate' is a function that
returns the truth value of some condition; for use with *note filter():
a66, the predicate must take a single value.

     >>> def is_even(x):
     ...     return (x % 2) == 0

     >>> list(filter(is_even, range(10)))
     [0, 2, 4, 6, 8]

This can also be written as a list comprehension:

     >>> list(x for x in range(10) if is_even(x))
     [0, 2, 4, 6, 8]

*note enumerate(iter, start=0): 1688. counts off the elements in the
iterable returning 2-tuples containing the count (from 'start') and each
element.

     >>> for item in enumerate(['subject', 'verb', 'object']):
     ...     print(item)
     (0, 'subject')
     (1, 'verb')
     (2, 'object')

*note enumerate(): 1688. is often used when looping through a list and
recording the indexes at which certain conditions are met:

     f = open('data.txt', 'r')
     for i, line in enumerate(f):
         if line.strip() == '':
             print('Blank line at line #%i' % i)

*note sorted(iterable, key=None, reverse=False): dc9. collects all the
elements of the iterable into a list, sorts the list, and returns the
sorted result.  The 'key' and 'reverse' arguments are passed through to
the constructed list’s *note sort(): dca. method.

     >>> import random
     >>> # Generate 8 random numbers between [0, 10000)
     >>> rand_list = random.sample(range(10000), 8)
     >>> rand_list
     [769, 7953, 9828, 6431, 8442, 9878, 6213, 2207]
     >>> sorted(rand_list)
     [769, 2207, 6213, 6431, 7953, 8442, 9828, 9878]
     >>> sorted(rand_list, reverse=True)
     [9878, 9828, 8442, 7953, 6431, 6213, 2207, 769]

(For a more detailed discussion of sorting, see the *note Sorting
Techniques: 25bb.)

The *note any(iter): 1628. and *note all(iter): 1629. built-ins look at
the truth values of an iterable’s contents.  *note any(): 1628. returns
‘True’ if any element in the iterable is a true value, and *note all():
1629. returns ‘True’ if all of the elements are true values:

     >>> any([0, 1, 0])
     True
     >>> any([0, 0, 0])
     False
     >>> any([1, 1, 1])
     True
     >>> all([0, 1, 0])
     False
     >>> all([0, 0, 0])
     False
     >>> all([1, 1, 1])
     True

*note zip(iterA, iterB, ...): 1a0. takes one element from each iterable
and returns them in a tuple:

     zip(['a', 'b', 'c'], (1, 2, 3)) =>
       ('a', 1), ('b', 2), ('c', 3)

It doesn’t construct an in-memory list and exhaust all the input
iterators before returning; instead tuples are constructed and returned
only if they’re requested.  (The technical term for this behaviour is
lazy evaluation(1).)

This iterator is intended to be used with iterables that are all of the
same length.  If the iterables are of different lengths, the resulting
stream will be the same length as the shortest iterable.

     zip(['a', 'b'], (1, 2, 3)) =>
       ('a', 1), ('b', 2)

You should avoid doing this, though, because an element may be taken
from the longer iterators and discarded.  This means you can’t go on to
use the iterators further because you risk skipping a discarded element.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Lazy_evaluation


File: python.info,  Node: The itertools module,  Next: The functools module,  Prev: Built-in functions<2>,  Up: Functional Programming HOWTO

9.7.6 The itertools module
--------------------------

The *note itertools: 85. module contains a number of commonly used
iterators as well as functions for combining several iterators.  This
section will introduce the module’s contents by showing small examples.

The module’s functions fall into a few broad classes:

   * Functions that create a new iterator based on an existing iterator.

   * Functions for treating an iterator’s elements as function
     arguments.

   * Functions for selecting portions of an iterator’s output.

   * A function for grouping an iterator’s output.

* Menu:

* Creating new iterators::
* Calling functions on elements::
* Selecting elements::
* Combinatoric functions::
* Grouping elements::


File: python.info,  Node: Creating new iterators,  Next: Calling functions on elements,  Up: The itertools module

9.7.6.1 Creating new iterators
..............................

*note itertools.count(start, step): 148b. returns an infinite stream of
evenly spaced values.  You can optionally supply the starting number,
which defaults to 0, and the interval between numbers, which defaults to
1:

     itertools.count() =>
       0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ...
     itertools.count(10) =>
       10, 11, 12, 13, 14, 15, 16, 17, 18, 19, ...
     itertools.count(10, 5) =>
       10, 15, 20, 25, 30, 35, 40, 45, 50, 55, ...

*note itertools.cycle(iter): 2b88. saves a copy of the contents of a
provided iterable and returns a new iterator that returns its elements
from first to last.  The new iterator will repeat these elements
infinitely.

     itertools.cycle([1, 2, 3, 4, 5]) =>
       1, 2, 3, 4, 5, 1, 2, 3, 4, 5, ...

*note itertools.repeat(elem, [n]): 1841. returns the provided element
'n' times, or returns the element endlessly if 'n' is not provided.

     itertools.repeat('abc') =>
       abc, abc, abc, abc, abc, abc, abc, abc, abc, abc, ...
     itertools.repeat('abc', 5) =>
       abc, abc, abc, abc, abc

*note itertools.chain(iterA, iterB, ...): 25bc. takes an arbitrary
number of iterables as input, and returns all the elements of the first
iterator, then all the elements of the second, and so on, until all of
the iterables have been exhausted.

     itertools.chain(['a', 'b', 'c'], (1, 2, 3)) =>
       a, b, c, 1, 2, 3

*note itertools.islice(iter, [start], stop, [step]): d45. returns a
stream that’s a slice of the iterator.  With a single 'stop' argument,
it will return the first 'stop' elements.  If you supply a starting
index, you’ll get 'stop-start' elements, and if you supply a value for
'step', elements will be skipped accordingly.  Unlike Python’s string
and list slicing, you can’t use negative values for 'start', 'stop', or
'step'.

     itertools.islice(range(10), 8) =>
       0, 1, 2, 3, 4, 5, 6, 7
     itertools.islice(range(10), 2, 8) =>
       2, 3, 4, 5, 6, 7
     itertools.islice(range(10), 2, 8, 2) =>
       2, 4, 6

*note itertools.tee(iter, [n]): 2b8d. replicates an iterator; it returns
'n' independent iterators that will all return the contents of the
source iterator.  If you don’t supply a value for 'n', the default is 2.
Replicating iterators requires saving some of the contents of the source
iterator, so this can consume significant memory if the iterator is
large and one of the new iterators is consumed more than the others.

     itertools.tee( itertools.count() ) =>
        iterA, iterB

     where iterA ->
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ...

     and   iterB ->
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ...


File: python.info,  Node: Calling functions on elements,  Next: Selecting elements,  Prev: Creating new iterators,  Up: The itertools module

9.7.6.2 Calling functions on elements
.....................................

The *note operator: a3. module contains a set of functions corresponding
to Python’s operators.  Some examples are *note operator.add(a, b):
2bb4. (adds two values), *note operator.ne(a, b): 2ba4. (same as ‘a !=
b’), and *note operator.attrgetter('id'): 1035. (returns a callable that
fetches the ‘.id’ attribute).

*note itertools.starmap(func, iter): 12ec. assumes that the iterable
will return a stream of tuples, and calls 'func' using these tuples as
the arguments:

     itertools.starmap(os.path.join,
                       [('/bin', 'python'), ('/usr', 'bin', 'java'),
                        ('/usr', 'bin', 'perl'), ('/usr', 'bin', 'ruby')])
     =>
       /bin/python, /usr/bin/java, /usr/bin/perl, /usr/bin/ruby


File: python.info,  Node: Selecting elements,  Next: Combinatoric functions,  Prev: Calling functions on elements,  Up: The itertools module

9.7.6.3 Selecting elements
..........................

Another group of functions chooses a subset of an iterator’s elements
based on a predicate.

*note itertools.filterfalse(predicate, iter): 25aa. is the opposite of
*note filter(): a66, returning all elements for which the predicate
returns false:

     itertools.filterfalse(is_even, itertools.count()) =>
       1, 3, 5, 7, 9, 11, 13, 15, ...

*note itertools.takewhile(predicate, iter): 2b8c. returns elements for
as long as the predicate returns true.  Once the predicate returns
false, the iterator will signal the end of its results.

     def less_than_10(x):
         return x < 10

     itertools.takewhile(less_than_10, itertools.count()) =>
       0, 1, 2, 3, 4, 5, 6, 7, 8, 9

     itertools.takewhile(is_even, itertools.count()) =>
       0

*note itertools.dropwhile(predicate, iter): 2b8a. discards elements
while the predicate returns true, and then returns the rest of the
iterable’s results.

     itertools.dropwhile(less_than_10, itertools.count()) =>
       10, 11, 12, 13, 14, 15, 16, 17, 18, 19, ...

     itertools.dropwhile(is_even, itertools.count()) =>
       1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ...

*note itertools.compress(data, selectors): 148a. takes two iterators and
returns only those elements of 'data' for which the corresponding
element of 'selectors' is true, stopping whenever either one is
exhausted:

     itertools.compress([1, 2, 3, 4, 5], [True, True, False, False, True]) =>
        1, 2, 5


File: python.info,  Node: Combinatoric functions,  Next: Grouping elements,  Prev: Selecting elements,  Up: The itertools module

9.7.6.4 Combinatoric functions
..............................

The *note itertools.combinations(iterable, r): 1519. returns an iterator
giving all possible 'r'-tuple combinations of the elements contained in
'iterable'.

     itertools.combinations([1, 2, 3, 4, 5], 2) =>
       (1, 2), (1, 3), (1, 4), (1, 5),
       (2, 3), (2, 4), (2, 5),
       (3, 4), (3, 5),
       (4, 5)

     itertools.combinations([1, 2, 3, 4, 5], 3) =>
       (1, 2, 3), (1, 2, 4), (1, 2, 5), (1, 3, 4), (1, 3, 5), (1, 4, 5),
       (2, 3, 4), (2, 3, 5), (2, 4, 5),
       (3, 4, 5)

The elements within each tuple remain in the same order as 'iterable'
returned them.  For example, the number 1 is always before 2, 3, 4, or 5
in the examples above.  A similar function, *note
itertools.permutations(iterable, r=None): 1cc5, removes this constraint
on the order, returning all possible arrangements of length 'r':

     itertools.permutations([1, 2, 3, 4, 5], 2) =>
       (1, 2), (1, 3), (1, 4), (1, 5),
       (2, 1), (2, 3), (2, 4), (2, 5),
       (3, 1), (3, 2), (3, 4), (3, 5),
       (4, 1), (4, 2), (4, 3), (4, 5),
       (5, 1), (5, 2), (5, 3), (5, 4)

     itertools.permutations([1, 2, 3, 4, 5]) =>
       (1, 2, 3, 4, 5), (1, 2, 3, 5, 4), (1, 2, 4, 3, 5),
       ...
       (5, 4, 3, 2, 1)

If you don’t supply a value for 'r' the length of the iterable is used,
meaning that all the elements are permuted.

Note that these functions produce all of the possible combinations by
position and don’t require that the contents of 'iterable' are unique:

     itertools.permutations('aba', 3) =>
       ('a', 'b', 'a'), ('a', 'a', 'b'), ('b', 'a', 'a'),
       ('b', 'a', 'a'), ('a', 'a', 'b'), ('a', 'b', 'a')

The identical tuple ‘('a', 'a', 'b')’ occurs twice, but the two “a”
strings came from different positions.

The *note itertools.combinations_with_replacement(iterable, r): 1489.
function relaxes a different constraint: elements can be repeated within
a single tuple.  Conceptually an element is selected for the first
position of each tuple and then is replaced before the second element is
selected.

     itertools.combinations_with_replacement([1, 2, 3, 4, 5], 2) =>
       (1, 1), (1, 2), (1, 3), (1, 4), (1, 5),
       (2, 2), (2, 3), (2, 4), (2, 5),
       (3, 3), (3, 4), (3, 5),
       (4, 4), (4, 5),
       (5, 5)


File: python.info,  Node: Grouping elements,  Prev: Combinatoric functions,  Up: The itertools module

9.7.6.5 Grouping elements
.........................

The last function I’ll discuss, *note itertools.groupby(iter,
key_func=None): 2b8b, is the most complicated.  ‘key_func(elem)’ is a
function that can compute a key value for each element returned by the
iterable.  If you don’t supply a key function, the key is simply each
element itself.

*note groupby(): 2b8b. collects all the consecutive elements from the
underlying iterable that have the same key value, and returns a stream
of 2-tuples containing a key value and an iterator for the elements with
that key.

     city_list = [('Decatur', 'AL'), ('Huntsville', 'AL'), ('Selma', 'AL'),
                  ('Anchorage', 'AK'), ('Nome', 'AK'),
                  ('Flagstaff', 'AZ'), ('Phoenix', 'AZ'), ('Tucson', 'AZ'),
                  ...
                 ]

     def get_state(city_state):
         return city_state[1]

     itertools.groupby(city_list, get_state) =>
       ('AL', iterator-1),
       ('AK', iterator-2),
       ('AZ', iterator-3), ...

     where
     iterator-1 =>
       ('Decatur', 'AL'), ('Huntsville', 'AL'), ('Selma', 'AL')
     iterator-2 =>
       ('Anchorage', 'AK'), ('Nome', 'AK')
     iterator-3 =>
       ('Flagstaff', 'AZ'), ('Phoenix', 'AZ'), ('Tucson', 'AZ')

*note groupby(): 2b8b. assumes that the underlying iterable’s contents
will already be sorted based on the key.  Note that the returned
iterators also use the underlying iterable, so you have to consume the
results of iterator-1 before requesting iterator-2 and its corresponding
key.


File: python.info,  Node: The functools module,  Next: Small functions and the lambda expression,  Prev: The itertools module,  Up: Functional Programming HOWTO

9.7.7 The functools module
--------------------------

The *note functools: 63. module contains some higher-order functions.  A
'higher-order function' takes one or more functions as input and returns
a new function.  The most useful tool in this module is the *note
functools.partial(): 217. function.

For programs written in a functional style, you’ll sometimes want to
construct variants of existing functions that have some of the
parameters filled in.  Consider a Python function ‘f(a, b, c)’; you may
wish to create a new function ‘g(b, c)’ that’s equivalent to ‘f(1, b,
c)’; you’re filling in a value for one of ‘f()’”s parameters.  This is
called «partial function application».

The constructor for *note partial(): 217. takes the arguments
‘(function, arg1, arg2, ..., kwarg1=value1, kwarg2=value2)’.  The
resulting object is callable, so you can just call it to invoke
‘function’ with the filled-in arguments.

Here’s a small but realistic example:

     import functools

     def log(message, subsystem):
         """Write the contents of 'message' to the specified subsystem."""
         print('%s: %s' % (subsystem, message))
         ...

     server_log = functools.partial(log, subsystem='server')
     server_log('Unable to open socket')

*note functools.reduce(func, iter, [initial_value]): 21a. cumulatively
performs an operation on all the iterable’s elements and, therefore,
can’t be applied to infinite iterables.  'func' must be a function that
takes two elements and returns a single value.  *note
functools.reduce(): 21a. takes the first two elements A and B returned
by the iterator and calculates ‘func(A, B)’.  It then requests the third
element, C, calculates ‘func(func(A, B), C)’, combines this result with
the fourth element returned, and continues until the iterable is
exhausted.  If the iterable returns no values at all, a *note TypeError:
198. exception is raised.  If the initial value is supplied, it’s used
as a starting point and ‘func(initial_value, A)’ is the first
calculation.

     >>> import operator, functools
     >>> functools.reduce(operator.concat, ['A', 'BB', 'C'])
     'ABBC'
     >>> functools.reduce(operator.concat, [])
     Traceback (most recent call last):
       ...
     TypeError: reduce() of empty sequence with no initial value
     >>> functools.reduce(operator.mul, [1, 2, 3], 1)
     6
     >>> functools.reduce(operator.mul, [], 1)
     1

If you use *note operator.add(): 2bb4. with *note functools.reduce():
21a, you’ll add up all the elements of the iterable.  This case is so
common that there’s a special built-in called *note sum(): 696. to
compute it:

     >>> import functools, operator
     >>> functools.reduce(operator.add, [1, 2, 3, 4], 0)
     10
     >>> sum([1, 2, 3, 4])
     10
     >>> sum([])
     0

For many uses of *note functools.reduce(): 21a, though, it can be
clearer to just write the obvious *note for: 34a. loop:

     import functools
     # Instead of:
     product = functools.reduce(operator.mul, [1, 2, 3], 1)

     # You can write:
     product = 1
     for i in [1, 2, 3]:
         product *= i

A related function is *note itertools.accumulate(iterable,
func=operator.add): bf2.  It performs the same calculation, but instead
of returning only the final result, *note accumulate(): bf2. returns an
iterator that also yields each partial result:

     itertools.accumulate([1, 2, 3, 4, 5]) =>
       1, 3, 6, 10, 15

     itertools.accumulate([1, 2, 3, 4, 5], operator.mul) =>
       1, 2, 6, 24, 120

* Menu:

* The operator module::


File: python.info,  Node: The operator module,  Up: The functools module

9.7.7.1 The operator module
...........................

The *note operator: a3. module was mentioned earlier.  It contains a set
of functions corresponding to Python’s operators.  These functions are
often useful in functional-style code because they save you from writing
trivial functions that perform a single operation.

Some of the functions in this module are:

   * Math operations: ‘add()’, ‘sub()’, ‘mul()’, ‘floordiv()’, ‘abs()’,
     …

   * Logical operations: ‘not_()’, ‘truth()’.

   * Bitwise operations: ‘and_()’, ‘or_()’, ‘invert()’.

   * Comparisons: ‘eq()’, ‘ne()’, ‘lt()’, ‘le()’, ‘gt()’, and ‘ge()’.

   * Object identity: ‘is_()’, ‘is_not()’.

Consult the operator module’s documentation for a complete list.


File: python.info,  Node: Small functions and the lambda expression,  Next: Revision History and Acknowledgements,  Prev: The functools module,  Up: Functional Programming HOWTO

9.7.8 Small functions and the lambda expression
-----------------------------------------------

When writing functional-style programs, you’ll often need little
functions that act as predicates or that combine elements in some way.

If there’s a Python built-in or a module function that’s suitable, you
don’t need to define a new function at all:

     stripped_lines = [line.strip() for line in lines]
     existing_files = filter(os.path.exists, file_list)

If the function you need doesn’t exist, you need to write it.  One way
to write small functions is to use the *note lambda: 14a5. expression.
‘lambda’ takes a number of parameters and an expression combining these
parameters, and creates an anonymous function that returns the value of
the expression:

     adder = lambda x, y: x+y

     print_assign = lambda name, value: name + '=' + str(value)

An alternative is to just use the ‘def’ statement and define a function
in the usual way:

     def adder(x, y):
         return x + y

     def print_assign(name, value):
         return name + '=' + str(value)

Which alternative is preferable?  That’s a style question; my usual
course is to avoid using ‘lambda’.

One reason for my preference is that ‘lambda’ is quite limited in the
functions it can define.  The result has to be computable as a single
expression, which means you can’t have multiway ‘if... elif... else’
comparisons or ‘try... except’ statements.  If you try to do too much in
a ‘lambda’ statement, you’ll end up with an overly complicated
expression that’s hard to read.  Quick, what’s the following code doing?

     import functools
     total = functools.reduce(lambda a, b: (0, a[1] + b[1]), items)[1]

You can figure it out, but it takes time to disentangle the expression
to figure out what’s going on.  Using a short nested ‘def’ statements
makes things a little bit better:

     import functools
     def combine(a, b):
         return 0, a[1] + b[1]

     total = functools.reduce(combine, items)[1]

But it would be best of all if I had simply used a ‘for’ loop:

     total = 0
     for a, b in items:
         total += b

Or the *note sum(): 696. built-in and a generator expression:

     total = sum(b for a, b in items)

Many uses of *note functools.reduce(): 21a. are clearer when written as
‘for’ loops.

Fredrik Lundh once suggested the following set of rules for refactoring
uses of ‘lambda’:

  1. Write a lambda function.

  2. Write a comment explaining what the heck that lambda does.

  3. Study the comment for a while, and think of a name that captures
     the essence of the comment.

  4. Convert the lambda to a def statement, using that name.

  5. Remove the comment.

I really like these rules, but you’re free to disagree about whether
this lambda-free style is better.


File: python.info,  Node: Revision History and Acknowledgements,  Next: References<2>,  Prev: Small functions and the lambda expression,  Up: Functional Programming HOWTO

9.7.9 Revision History and Acknowledgements
-------------------------------------------

The author would like to thank the following people for offering
suggestions, corrections and assistance with various drafts of this
article: Ian Bicking, Nick Coghlan, Nick Efford, Raymond Hettinger, Jim
Jewett, Mike Krell, Leandro Lameiro, Jussi Salmela, Collin Winter, Blake
Winton.

Version 0.1: posted June 30 2006.

Version 0.11: posted July 1 2006.  Typo fixes.

Version 0.2: posted July 10 2006.  Merged genexp and listcomp sections
into one.  Typo fixes.

Version 0.21: Added more references suggested on the tutor mailing list.

Version 0.30: Adds a section on the ‘functional’ module written by
Collin Winter; adds short section on the operator module; a few other
edits.


File: python.info,  Node: References<2>,  Prev: Revision History and Acknowledgements,  Up: Functional Programming HOWTO

9.7.10 References
-----------------

* Menu:

* General::
* Python-specific::
* Python documentation::


File: python.info,  Node: General,  Next: Python-specific,  Up: References<2>

9.7.10.1 General
................

'Structure and Interpretation of Computer Programs', by Harold Abelson
and Gerald Jay Sussman with Julie Sussman.  The book can be found at
‘https://mitpress.mit.edu/sicp’.  In this classic textbook of computer
science, chapters 2 and 3 discuss the use of sequences and streams to
organize the data flow inside a program.  The book uses Scheme for its
examples, but many of the design approaches described in these chapters
are applicable to functional-style Python code.

‘https://defmacro.org/2006/06/19/fp.html’: A general introduction to
functional programming that uses Java examples and has a lengthy
historical introduction.

‘https://en.wikipedia.org/wiki/Functional_programming’: General
Wikipedia entry describing functional programming.

‘https://en.wikipedia.org/wiki/Coroutine’: Entry for coroutines.

‘https://en.wikipedia.org/wiki/Partial_application’: Entry for the
concept of partial function application.

‘https://en.wikipedia.org/wiki/Currying’: Entry for the concept of
currying.


File: python.info,  Node: Python-specific,  Next: Python documentation,  Prev: General,  Up: References<2>

9.7.10.2 Python-specific
........................

‘https://gnosis.cx/TPiP/’: The first chapter of David Mertz’s book ‘Text
Processing in Python’ discusses functional programming for text
processing, in the section titled «Utilizing Higher-Order Functions in
Text Processing».

Mertz also wrote a 3-part series of articles on functional programming
for IBM’s DeveloperWorks site; see part 1(1), part 2(2), and part 3(3),

   ---------- Footnotes ----------

   (1) https://developer.ibm.com/articles/l-prog/

   (2) https://developer.ibm.com/tutorials/l-prog2/

   (3) https://developer.ibm.com/tutorials/l-prog3/


File: python.info,  Node: Python documentation,  Prev: Python-specific,  Up: References<2>

9.7.10.3 Python documentation
.............................

Documentation for the *note itertools: 85. module.

Documentation for the *note functools: 63. module.

Documentation for the *note operator: a3. module.

PEP 289(1): «Generator Expressions»

PEP 342(2): «Coroutines via Enhanced Generators» describes the new
generator features in Python 2.5.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0289/

   (2) https://peps.python.org/pep-0342/


File: python.info,  Node: Logging HOWTO,  Next: Logging Cookbook,  Prev: Functional Programming HOWTO,  Up: Python HOWTOs

9.8 Logging HOWTO
=================


Author: Vinay Sajip <vinay_sajip at red-dove dot com>

This page contains tutorial information.  For links to reference
information and a logging cookbook, please see *note Other resources:
571c.

* Menu:

* Basic Logging Tutorial::
* Advanced Logging Tutorial::
* Logging Levels: Logging Levels<2>.
* Useful Handlers::
* Exceptions raised during logging::
* Using arbitrary objects as messages::
* Optimization::
* Other resources::


File: python.info,  Node: Basic Logging Tutorial,  Next: Advanced Logging Tutorial,  Up: Logging HOWTO

9.8.1 Basic Logging Tutorial
----------------------------

Logging is a means of tracking events that happen when some software
runs.  The software’s developer adds logging calls to their code to
indicate that certain events have occurred.  An event is described by a
descriptive message which can optionally contain variable data (i.e.
data that is potentially different for each occurrence of the event).
Events also have an importance which the developer ascribes to the
event; the importance can also be called the 'level' or 'severity'.

* Menu:

* When to use logging::
* A simple example::
* Logging to a file::
* Logging variable data::
* Changing the format of displayed messages::
* Displaying the date/time in messages::
* Next Steps::


File: python.info,  Node: When to use logging,  Next: A simple example,  Up: Basic Logging Tutorial

9.8.1.1 When to use logging
...........................

You can access logging functionality by creating a logger via ‘logger =
getLogger(__name__)’, and then calling the logger’s *note debug(): 102d,
*note info(): 3142, *note warning(): 1a5c, *note error(): 3144. and
*note critical(): 102c. methods.  To determine when to use logging, and
to see which logger methods to use when, see the table below.  It
states, for each of a set of common tasks, the best tool to use for that
task.

Task you want to perform                  The best tool for the task
                                          
-------------------------------------------------------------------------------------
                                          
Display console output for ordinary       *note print(): 1177.
usage of a command line script or         
program

Report events that occur during normal    A logger’s *note info(): 3142. (or
operation of a program (e.g.  for         *note debug(): 102d. method for very
status monitoring or fault                detailed output for diagnostic purposes)
investigation)                            

Issue a warning regarding a particular    *note warnings.warn(): 1720. in library
runtime event                             code if the issue is avoidable and the
                                          client application should be modified to
                                          eliminate the warning
                                          
                                          A logger’s *note warning(): 1a5c. method
                                          if there is nothing the client
                                          application can do about the situation,
                                          but the event should still be noted
                                          
                                          
Report an error regarding a particular    Raise an exception
runtime event                             

Report suppression of an error without    A logger’s *note error(): 3144,
raising an exception (e.g.  error         *note exception(): 102b. or
handler in a long-running server          *note critical(): 102c. method as
process)                                  appropriate for the specific error and
                                          application domain
                                          

The logger methods are named after the level or severity of the events
they are used to track.  The standard levels and their applicability are
described below (in increasing order of severity):

Level              When it’s used
                   
---------------------------------------------------------------------
                   
‘DEBUG’            Detailed information, typically of interest
                   only when diagnosing problems.
                   
                   
‘INFO’             Confirmation that things are working as
                   expected.
                   
                   
‘WARNING’          An indication that something unexpected
                   happened, or indicative of some problem in the
                   near future (e.g.  “disk space low”).  The
                   software is still working as expected.
                   
                   
‘ERROR’            Due to a more serious problem, the software has
                   not been able to perform some function.
                   
                   
‘CRITICAL’         A serious error, indicating that the program
                   itself may be unable to continue running.
                   

The default level is ‘WARNING’, which means that only events of this
severity and higher will be tracked, unless the logging package is
configured to do otherwise.

Events that are tracked can be handled in different ways.  The simplest
way of handling tracked events is to print them to the console.  Another
common way is to write them to a disk file.


File: python.info,  Node: A simple example,  Next: Logging to a file,  Prev: When to use logging,  Up: Basic Logging Tutorial

9.8.1.2 A simple example
........................

A very simple example is:

     import logging
     logging.warning('Watch out!')  # will print a message to the console
     logging.info('I told you so')  # will not print anything

If you type these lines into a script and run it, you’ll see:

     WARNING:root:Watch out!

printed out on the console.  The ‘INFO’ message doesn’t appear because
the default level is ‘WARNING’.  The printed message includes the
indication of the level and the description of the event provided in the
logging call, i.e.  “Watch out!”.  The actual output can be formatted
quite flexibly if you need that; formatting options will also be
explained later.

Notice that in this example, we use functions directly on the ‘logging’
module, like ‘logging.debug’, rather than creating a logger and calling
functions on it.  These functions operate on the root logger, but can be
useful as they will call *note basicConfig(): bf5. for you if it has not
been called yet, like in this example.  In larger programs you’ll
usually want to control the logging configuration explicitly however -
so for that reason as well as others, it’s better to create loggers and
call their methods.


File: python.info,  Node: Logging to a file,  Next: Logging variable data,  Prev: A simple example,  Up: Basic Logging Tutorial

9.8.1.3 Logging to a file
.........................

A very common situation is that of recording logging events in a file,
so let’s look at that next.  Be sure to try the following in a newly
started Python interpreter, and don’t just continue from the session
described above:

     import logging
     logger = logging.getLogger(__name__)
     logging.basicConfig(filename='example.log', encoding='utf-8', level=logging.DEBUG)
     logger.debug('This message should go to the log file')
     logger.info('So should this')
     logger.warning('And this, too')
     logger.error('And non-ASCII stuff, too, like Øresund and Malmö')

Cambiato nella versione 3.9: The 'encoding' argument was added.  In
earlier Python versions, or if not specified, the encoding used is the
default value used by *note open(): 316.  While not shown in the above
example, an 'errors' argument can also now be passed, which determines
how encoding errors are handled.  For available values and the default,
see the documentation for *note open(): 316.

And now if we open the file and look at what we have, we should find the
log messages:

     DEBUG:__main__:This message should go to the log file
     INFO:__main__:So should this
     WARNING:__main__:And this, too
     ERROR:__main__:And non-ASCII stuff, too, like Øresund and Malmö

This example also shows how you can set the logging level which acts as
the threshold for tracking.  In this case, because we set the threshold
to ‘DEBUG’, all of the messages were printed.

If you want to set the logging level from a command-line option such as:

     --log=INFO

and you have the value of the parameter passed for ‘--log’ in some
variable 'loglevel', you can use:

     getattr(logging, loglevel.upper())

to get the value which you’ll pass to *note basicConfig(): bf5. via the
'level' argument.  You may want to error check any user input value,
perhaps as in the following example:

     # assuming loglevel is bound to the string value obtained from the
     # command line argument. Convert to upper case to allow the user to
     # specify --log=DEBUG or --log=debug
     numeric_level = getattr(logging, loglevel.upper(), None)
     if not isinstance(numeric_level, int):
         raise ValueError('Invalid log level: %s' % loglevel)
     logging.basicConfig(level=numeric_level, ...)

The call to *note basicConfig(): bf5. should come 'before' any calls to
a logger’s methods such as *note debug(): 102d, *note info(): 3142, etc.
Otherwise, that logging event may not be handled in the desired manner.

If you run the above script several times, the messages from successive
runs are appended to the file 'example.log'.  If you want each run to
start afresh, not remembering the messages from earlier runs, you can
specify the 'filemode' argument, by changing the call in the above
example to:

     logging.basicConfig(filename='example.log', filemode='w', level=logging.DEBUG)

The output will be the same as before, but the log file is no longer
appended to, so the messages from earlier runs are lost.


File: python.info,  Node: Logging variable data,  Next: Changing the format of displayed messages,  Prev: Logging to a file,  Up: Basic Logging Tutorial

9.8.1.4 Logging variable data
.............................

To log variable data, use a format string for the event description
message and append the variable data as arguments.  For example:

     import logging
     logging.warning('%s before you %s', 'Look', 'leap!')

will display:

     WARNING:root:Look before you leap!

As you can see, merging of variable data into the event description
message uses the old, %-style of string formatting.  This is for
backwards compatibility: the logging package pre-dates newer formatting
options such as *note str.format(): 834. and *note string.Template: 898.
These newer formatting options 'are' supported, but exploring them is
outside the scope of this tutorial: see *note Using particular
formatting styles throughout your application: 3161. for more
information.


File: python.info,  Node: Changing the format of displayed messages,  Next: Displaying the date/time in messages,  Prev: Logging variable data,  Up: Basic Logging Tutorial

9.8.1.5 Changing the format of displayed messages
.................................................

To change the format which is used to display messages, you need to
specify the format you want to use:

     import logging
     logging.basicConfig(format='%(levelname)s:%(message)s', level=logging.DEBUG)
     logging.debug('This message should appear on the console')
     logging.info('So should this')
     logging.warning('And this, too')

which would print:

     DEBUG:This message should appear on the console
     INFO:So should this
     WARNING:And this, too

Notice that the “root” which appeared in earlier examples has
disappeared.  For a full set of things that can appear in format
strings, you can refer to the documentation for *note LogRecord
attributes: 3141, but for simple usage, you just need the 'levelname'
(severity), 'message' (event description, including variable data) and
perhaps to display when the event occurred.  This is described in the
next section.


File: python.info,  Node: Displaying the date/time in messages,  Next: Next Steps,  Prev: Changing the format of displayed messages,  Up: Basic Logging Tutorial

9.8.1.6 Displaying the date/time in messages
............................................

To display the date and time of an event, you would place “%(asctime)s”
in your format string:

     import logging
     logging.basicConfig(format='%(asctime)s %(message)s')
     logging.warning('is when this event was logged.')

which should print something like this:

     2010-12-12 11:41:42,612 is when this event was logged.

The default format for date/time display (shown above) is like ISO8601
or RFC 3339(1).  If you need more control over the formatting of the
date/time, provide a 'datefmt' argument to ‘basicConfig’, as in this
example:

     import logging
     logging.basicConfig(format='%(asctime)s %(message)s', datefmt='%m/%d/%Y %I:%M:%S %p')
     logging.warning('is when this event was logged.')

which would display something like this:

     12/12/2010 11:46:36 AM is when this event was logged.

The format of the 'datefmt' argument is the same as supported by *note
time.strftime(): 13f1.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc3339.html


File: python.info,  Node: Next Steps,  Prev: Displaying the date/time in messages,  Up: Basic Logging Tutorial

9.8.1.7 Next Steps
..................

That concludes the basic tutorial.  It should be enough to get you up
and running with logging.  There’s a lot more that the logging package
offers, but to get the best out of it, you’ll need to invest a little
more of your time in reading the following sections.  If you’re ready
for that, grab some of your favourite beverage and carry on.

If your logging needs are simple, then use the above examples to
incorporate logging into your own scripts, and if you run into problems
or don’t understand something, please post a question in the Help
category of the Python discussion forum(1) and you should receive help
before too long.

Still here?  You can carry on reading the next few sections, which
provide a slightly more advanced/in-depth tutorial than the basic one
above.  After that, you can take a look at the *note Logging Cookbook:
13ff.

   ---------- Footnotes ----------

   (1) https://discuss.python.org/c/help/7


File: python.info,  Node: Advanced Logging Tutorial,  Next: Logging Levels<2>,  Prev: Basic Logging Tutorial,  Up: Logging HOWTO

9.8.2 Advanced Logging Tutorial
-------------------------------

The logging library takes a modular approach and offers several
categories of components: loggers, handlers, filters, and formatters.

   * Loggers expose the interface that application code directly uses.

   * Handlers send the log records (created by loggers) to the
     appropriate destination.

   * Filters provide a finer grained facility for determining which log
     records to output.

   * Formatters specify the layout of log records in the final output.

Log event information is passed between loggers, handlers, filters and
formatters in a *note LogRecord: 11e8. instance.

Logging is performed by calling methods on instances of the *note
Logger: d48. class (hereafter called 'loggers').  Each instance has a
name, and they are conceptually arranged in a namespace hierarchy using
dots (periods) as separators.  For example, a logger named “scan” is the
parent of loggers “scan.text”, “scan.html” and “scan.pdf”.  Logger names
can be anything you want, and indicate the area of an application in
which a logged message originates.

A good convention to use when naming loggers is to use a module-level
logger, in each module which uses logging, named as follows:

     logger = logging.getLogger(__name__)

This means that logger names track the package/module hierarchy, and
it’s intuitively obvious where events are logged just from the logger
name.

The root of the hierarchy of loggers is called the root logger.  That’s
the logger used by the functions *note debug(): 3143, *note info():
316c, *note warning(): 354, *note error(): 3180. and *note critical():
3181, which just call the same-named method of the root logger.  The
functions and the methods have the same signatures.  The root logger’s
name is printed as “root” in the logged output.

It is, of course, possible to log messages to different destinations.
Support is included in the package for writing log messages to files,
HTTP GET/POST locations, email via SMTP, generic sockets, queues, or
OS-specific logging mechanisms such as syslog or the Windows NT event
log.  Destinations are served by 'handler' classes.  You can create your
own log destination class if you have special requirements not met by
any of the built-in handler classes.

By default, no destination is set for any logging messages.  You can
specify a destination (such as console or file) by using *note
basicConfig(): bf5. as in the tutorial examples.  If you call the
functions *note debug(): 3143, *note info(): 316c, *note warning(): 354,
*note error(): 3180. and *note critical(): 3181, they will check to see
if no destination is set; and if one is not set, they will set a
destination of the console (‘sys.stderr’) and a default format for the
displayed message before delegating to the root logger to do the actual
message output.

The default format set by *note basicConfig(): bf5. for messages is:

     severity:logger name:message

You can change this by passing a format string to *note basicConfig():
bf5. with the 'format' keyword argument.  For all options regarding how
a format string is constructed, see *note Formatter Objects: 315e.

* Menu:

* Logging Flow::
* Loggers::
* Handlers::
* Formatters::
* Configuring Logging::
* What happens if no configuration is provided::
* Configuring Logging for a Library::


File: python.info,  Node: Logging Flow,  Next: Loggers,  Up: Advanced Logging Tutorial

9.8.2.1 Logging Flow
....................

The flow of log event information in loggers and handlers is illustrated
in the following diagram.

[image src="python-figures/logging_flow.png"]



File: python.info,  Node: Loggers,  Next: Handlers,  Prev: Logging Flow,  Up: Advanced Logging Tutorial

9.8.2.2 Loggers
...............

*note Logger: d48. objects have a threefold job.  First, they expose
several methods to application code so that applications can log
messages at runtime.  Second, logger objects determine which log
messages to act upon based upon severity (the default filtering
facility) or filter objects.  Third, logger objects pass along relevant
log messages to all interested log handlers.

The most widely used methods on logger objects fall into two categories:
configuration and message sending.

These are the most common configuration methods:

   * *note Logger.setLevel(): 169a. specifies the lowest-severity log
     message a logger will handle, where debug is the lowest built-in
     severity level and critical is the highest built-in severity.  For
     example, if the severity level is INFO, the logger will handle only
     INFO, WARNING, ERROR, and CRITICAL messages and will ignore DEBUG
     messages.

   * *note Logger.addHandler(): 313c. and *note Logger.removeHandler():
     313d. add and remove handler objects from the logger object.
     Handlers are covered in more detail in *note Handlers: 5729.

   * *note Logger.addFilter(): 3145. and *note Logger.removeFilter():
     3146. add and remove filter objects from the logger object.
     Filters are covered in more detail in *note Filter Objects: 3169.

You don’t need to always call these methods on every logger you create.
See the last two paragraphs in this section.

With the logger object configured, the following methods create log
messages:

   * *note Logger.debug(): 102d, *note Logger.info(): 3142, *note
     Logger.warning(): 1a5c, *note Logger.error(): 3144, and *note
     Logger.critical(): 102c. all create log records with a message and
     a level that corresponds to their respective method names.  The
     message is actually a format string, which may contain the standard
     string substitution syntax of ‘%s’, ‘%d’, ‘%f’, and so on.  The
     rest of their arguments is a list of objects that correspond with
     the substitution fields in the message.  With regard to ‘**kwargs’,
     the logging methods care only about a keyword of ‘exc_info’ and use
     it to determine whether to log exception information.

   * *note Logger.exception(): 102b. creates a log message similar to
     *note Logger.error(): 3144.  The difference is that *note
     Logger.exception(): 102b. dumps a stack trace along with it.  Call
     this method only from an exception handler.

   * *note Logger.log(): 102a. takes a log level as an explicit
     argument.  This is a little more verbose for logging messages than
     using the log level convenience methods listed above, but this is
     how to log at custom log levels.

*note getLogger(): b5b. returns a reference to a logger instance with
the specified name if it is provided, or ‘root’ if not.  The names are
period-separated hierarchical structures.  Multiple calls to *note
getLogger(): b5b. with the same name will return a reference to the same
logger object.  Loggers that are further down in the hierarchical list
are children of loggers higher up in the list.  For example, given a
logger with a name of ‘foo’, loggers with names of ‘foo.bar’,
‘foo.bar.baz’, and ‘foo.bam’ are all descendants of ‘foo’.

Loggers have a concept of 'effective level'.  If a level is not
explicitly set on a logger, the level of its parent is used instead as
its effective level.  If the parent has no explicit level set, 'its'
parent is examined, and so on - all ancestors are searched until an
explicitly set level is found.  The root logger always has an explicit
level set (‘WARNING’ by default).  When deciding whether to process an
event, the effective level of the logger is used to determine whether
the event is passed to the logger’s handlers.

Child loggers propagate messages up to the handlers associated with
their ancestor loggers.  Because of this, it is unnecessary to define
and configure handlers for all the loggers an application uses.  It is
sufficient to configure handlers for a top-level logger and create child
loggers as needed.  (You can, however, turn off propagation by setting
the 'propagate' attribute of a logger to ‘False’.)


File: python.info,  Node: Handlers,  Next: Formatters,  Prev: Loggers,  Up: Advanced Logging Tutorial

9.8.2.3 Handlers
................

*note Handler: 169d. objects are responsible for dispatching the
appropriate log messages (based on the log messages” severity) to the
handler’s specified destination.  *note Logger: d48. objects can add
zero or more handler objects to themselves with an *note addHandler():
313c. method.  As an example scenario, an application may want to send
all log messages to a log file, all log messages of error or higher to
stdout, and all messages of critical to an email address.  This scenario
requires three individual handlers where each handler is responsible for
sending messages of a specific severity to a specific location.

The standard library includes quite a few handler types (see *note
Useful Handlers: 572b.); the tutorials use mainly *note StreamHandler:
1400. and *note FileHandler: 1c3b. in its examples.

There are very few methods in a handler for application developers to
concern themselves with.  The only handler methods that seem relevant
for application developers who are using the built-in handler objects
(that is, not creating custom handlers) are the following configuration
methods:

   * The *note setLevel(): 3153. method, just as in logger objects,
     specifies the lowest severity that will be dispatched to the
     appropriate destination.  Why are there two *note setLevel(): 3153.
     methods?  The level set in the logger determines which severity of
     messages it will pass to its handlers.  The level set in each
     handler determines which messages that handler will send on.

   * *note setFormatter(): 3154. selects a Formatter object for this
     handler to use.

   * *note addFilter(): 3155. and *note removeFilter(): 3156.
     respectively configure and deconfigure filter objects on handlers.

Application code should not directly instantiate and use instances of
*note Handler: 169d.  Instead, the *note Handler: 169d. class is a base
class that defines the interface that all handlers should have and
establishes some default behavior that child classes can use (or
override).


File: python.info,  Node: Formatters,  Next: Configuring Logging,  Prev: Handlers,  Up: Advanced Logging Tutorial

9.8.2.4 Formatters
..................

Formatter objects configure the final order, structure, and contents of
the log message.  Unlike the base *note logging.Handler: 169d. class,
application code may instantiate formatter classes, although you could
likely subclass the formatter if your application needs special
behavior.  The constructor takes three optional arguments – a message
format string, a date format string and a style indicator.

 -- Metodo: logging.Formatter.__init__ (fmt=None, datefmt=None,
          style='%')

If there is no message format string, the default is to use the raw
message.  If there is no date format string, the default date format is:

     %Y-%m-%d %H:%M:%S

with the milliseconds tacked on at the end.  The ‘style’ is one of
‘'%'’, ‘'{'’, or ‘'$'’.  If one of these is not specified, then ‘'%'’
will be used.

If the ‘style’ is ‘'%'’, the message format string uses ‘%(<dictionary
key>)s’ styled string substitution; the possible keys are documented in
*note LogRecord attributes: 3141.  If the style is ‘'{'’, the message
format string is assumed to be compatible with *note str.format(): 834.
(using keyword arguments), while if the style is ‘'$'’ then the message
format string should conform to what is expected by *note
string.Template.substitute(): 20bf.

Cambiato nella versione 3.2: Added the ‘style’ parameter.

The following message format string will log the time in a
human-readable format, the severity of the message, and the contents of
the message, in that order:

     '%(asctime)s - %(levelname)s - %(message)s'

Formatters use a user-configurable function to convert the creation time
of a record to a tuple.  By default, *note time.localtime(): 1700. is
used; to change this for a particular formatter instance, set the
‘converter’ attribute of the instance to a function with the same
signature as *note time.localtime(): 1700. or *note time.gmtime(): 13c8.
To change it for all formatters, for example if you want all logging
times to be shown in GMT, set the ‘converter’ attribute in the Formatter
class (to ‘time.gmtime’ for GMT display).


File: python.info,  Node: Configuring Logging,  Next: What happens if no configuration is provided,  Prev: Formatters,  Up: Advanced Logging Tutorial

9.8.2.5 Configuring Logging
...........................

Programmers can configure logging in three ways:

  1. Creating loggers, handlers, and formatters explicitly using Python
     code that calls the configuration methods listed above.

  2. Creating a logging config file and reading it using the *note
     fileConfig(): d4a. function.

  3. Creating a dictionary of configuration information and passing it
     to the *note dictConfig(): 13b8. function.

For the reference documentation on the last two options, see *note
Configuration functions: 14f9.  The following example configures a very
simple logger, a console handler, and a simple formatter using Python
code:

     import logging

     # create logger
     logger = logging.getLogger('simple_example')
     logger.setLevel(logging.DEBUG)

     # create console handler and set level to debug
     ch = logging.StreamHandler()
     ch.setLevel(logging.DEBUG)

     # create formatter
     formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')

     # add formatter to ch
     ch.setFormatter(formatter)

     # add ch to logger
     logger.addHandler(ch)

     # 'application' code
     logger.debug('debug message')
     logger.info('info message')
     logger.warning('warn message')
     logger.error('error message')
     logger.critical('critical message')

Running this module from the command line produces the following output:

     $ python simple_logging_module.py
     2005-03-19 15:10:26,618 - simple_example - DEBUG - debug message
     2005-03-19 15:10:26,620 - simple_example - INFO - info message
     2005-03-19 15:10:26,695 - simple_example - WARNING - warn message
     2005-03-19 15:10:26,697 - simple_example - ERROR - error message
     2005-03-19 15:10:26,773 - simple_example - CRITICAL - critical message

The following Python module creates a logger, handler, and formatter
nearly identical to those in the example listed above, with the only
difference being the names of the objects:

     import logging
     import logging.config

     logging.config.fileConfig('logging.conf')

     # create logger
     logger = logging.getLogger('simpleExample')

     # 'application' code
     logger.debug('debug message')
     logger.info('info message')
     logger.warning('warn message')
     logger.error('error message')
     logger.critical('critical message')

Here is the logging.conf file:

     [loggers]
     keys=root,simpleExample

     [handlers]
     keys=consoleHandler

     [formatters]
     keys=simpleFormatter

     [logger_root]
     level=DEBUG
     handlers=consoleHandler

     [logger_simpleExample]
     level=DEBUG
     handlers=consoleHandler
     qualname=simpleExample
     propagate=0

     [handler_consoleHandler]
     class=StreamHandler
     level=DEBUG
     formatter=simpleFormatter
     args=(sys.stdout,)

     [formatter_simpleFormatter]
     format=%(asctime)s - %(name)s - %(levelname)s - %(message)s

The output is nearly identical to that of the non-config-file-based
example:

     $ python simple_logging_config.py
     2005-03-19 15:38:55,977 - simpleExample - DEBUG - debug message
     2005-03-19 15:38:55,979 - simpleExample - INFO - info message
     2005-03-19 15:38:56,054 - simpleExample - WARNING - warn message
     2005-03-19 15:38:56,055 - simpleExample - ERROR - error message
     2005-03-19 15:38:56,130 - simpleExample - CRITICAL - critical message

You can see that the config file approach has a few advantages over the
Python code approach, mainly separation of configuration and code and
the ability of noncoders to easily modify the logging properties.

     Avvertimento: The *note fileConfig(): d4a. function takes a default
     parameter, ‘disable_existing_loggers’, which defaults to ‘True’ for
     reasons of backward compatibility.  This may or may not be what you
     want, since it will cause any non-root loggers existing before the
     *note fileConfig(): d4a. call to be disabled unless they (or an
     ancestor) are explicitly named in the configuration.  Please refer
     to the reference documentation for more information, and specify
     ‘False’ for this parameter if you wish.

     The dictionary passed to *note dictConfig(): 13b8. can also specify
     a Boolean value with key ‘disable_existing_loggers’, which if not
     specified explicitly in the dictionary also defaults to being
     interpreted as ‘True’.  This leads to the logger-disabling
     behaviour described above, which may not be what you want - in
     which case, provide the key explicitly with a value of ‘False’.

Note that the class names referenced in config files need to be either
relative to the logging module, or absolute values which can be resolved
using normal import mechanisms.  Thus, you could use either *note
WatchedFileHandler: 31c0. (relative to the logging module) or
‘mypackage.mymodule.MyHandler’ (for a class defined in package
‘mypackage’ and module ‘mymodule’, where ‘mypackage’ is available on the
Python import path).

In Python 3.2, a new means of configuring logging has been introduced,
using dictionaries to hold configuration information.  This provides a
superset of the functionality of the config-file-based approach outlined
above, and is the recommended configuration method for new applications
and deployments.  Because a Python dictionary is used to hold
configuration information, and since you can populate that dictionary
using different means, you have more options for configuration.  For
example, you can use a configuration file in JSON format, or, if you
have access to YAML processing functionality, a file in YAML format, to
populate the configuration dictionary.  Or, of course, you can construct
the dictionary in Python code, receive it in pickled form over a socket,
or use whatever approach makes sense for your application.

Here’s an example of the same configuration as above, in YAML format for
the new dictionary-based approach:

     version: 1
     formatters:
       simple:
         format: '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
     handlers:
       console:
         class: logging.StreamHandler
         level: DEBUG
         formatter: simple
         stream: ext://sys.stdout
     loggers:
       simpleExample:
         level: DEBUG
         handlers: [console]
         propagate: no
     root:
       level: DEBUG
       handlers: [console]

For more information about logging using a dictionary, see *note
Configuration functions: 14f9.


File: python.info,  Node: What happens if no configuration is provided,  Next: Configuring Logging for a Library,  Prev: Configuring Logging,  Up: Advanced Logging Tutorial

9.8.2.6 What happens if no configuration is provided
....................................................

If no logging configuration is provided, it is possible to have a
situation where a logging event needs to be output, but no handlers can
be found to output the event.

The event is output using a “handler of last resort”, stored in *note
lastResort: 1402.  This internal handler is not associated with any
logger, and acts like a *note StreamHandler: 1400. which writes the
event description message to the current value of ‘sys.stderr’
(therefore respecting any redirections which may be in effect).  No
formatting is done on the message - just the bare event description
message is printed.  The handler’s level is set to ‘WARNING’, so all
events at this and greater severities will be output.

Cambiato nella versione 3.2: For versions of Python prior to 3.2, the
behaviour is as follows:

   * If *note raiseExceptions: 1401. is ‘False’ (production mode), the
     event is silently dropped.

   * If *note raiseExceptions: 1401. is ‘True’ (development mode), a
     message “No handlers could be found for logger X.Y.Z” is printed
     once.

To obtain the pre-3.2 behaviour, *note lastResort: 1402. can be set to
‘None’.


File: python.info,  Node: Configuring Logging for a Library,  Prev: What happens if no configuration is provided,  Up: Advanced Logging Tutorial

9.8.2.7 Configuring Logging for a Library
.........................................

When developing a library which uses logging, you should take care to
document how the library uses logging - for example, the names of
loggers used.  Some consideration also needs to be given to its logging
configuration.  If the using application does not use logging, and
library code makes logging calls, then (as described in the previous
section) events of severity ‘WARNING’ and greater will be printed to
‘sys.stderr’.  This is regarded as the best default behaviour.

If for some reason you 'don’t' want these messages printed in the
absence of any logging configuration, you can attach a do-nothing
handler to the top-level logger for your library.  This avoids the
message being printed, since a handler will always be found for the
library’s events: it just doesn’t produce any output.  If the library
user configures logging for application use, presumably that
configuration will add some handlers, and if levels are suitably
configured then logging calls made in library code will send output to
those handlers, as normal.

A do-nothing handler is included in the logging package: *note
NullHandler: 148c. (since Python 3.1).  An instance of this handler
could be added to the top-level logger of the logging namespace used by
the library ('if' you want to prevent your library’s logged events being
output to ‘sys.stderr’ in the absence of logging configuration).  If all
logging by a library 'foo' is done using loggers with names matching
“foo.x”, “foo.x.y”, etc.  then the code:

     import logging
     logging.getLogger('foo').addHandler(logging.NullHandler())

should have the desired effect.  If an organisation produces a number of
libraries, then the logger name specified can be “orgname.foo” rather
than just “foo”.

     Nota: It is strongly advised that you 'do not log to the root
     logger' in your library.  Instead, use a logger with a unique and
     easily identifiable name, such as the ‘__name__’ for your library’s
     top-level package or module.  Logging to the root logger will make
     it difficult or impossible for the application developer to
     configure the logging verbosity or handlers of your library as they
     wish.

     Nota: It is strongly advised that you 'do not add any handlers
     other than' *note NullHandler: 148c. 'to your library’s loggers'.
     This is because the configuration of handlers is the prerogative of
     the application developer who uses your library.  The application
     developer knows their target audience and what handlers are most
     appropriate for their application: if you add handlers “under the
     hood”, you might well interfere with their ability to carry out
     unit tests and deliver logs which suit their requirements.


File: python.info,  Node: Logging Levels<2>,  Next: Useful Handlers,  Prev: Advanced Logging Tutorial,  Up: Logging HOWTO

9.8.3 Logging Levels
--------------------

The numeric values of logging levels are given in the following table.
These are primarily of interest if you want to define your own levels,
and need them to have specific values relative to the predefined levels.
If you define a level with the same numeric value, it overwrites the
predefined value; the predefined name is lost.

Level              Numeric value
                   
---------------------------------------
                   
‘CRITICAL’         50
                   
                   
‘ERROR’            40
                   
                   
‘WARNING’          30
                   
                   
‘INFO’             20
                   
                   
‘DEBUG’            10
                   
                   
‘NOTSET’           0
                   

Levels can also be associated with loggers, being set either by the
developer or through loading a saved logging configuration.  When a
logging method is called on a logger, the logger compares its own level
with the level associated with the method call.  If the logger’s level
is higher than the method call’s, no logging message is actually
generated.  This is the basic mechanism controlling the verbosity of
logging output.

Logging messages are encoded as instances of the *note LogRecord: 11e8.
class.  When a logger decides to actually log an event, a *note
LogRecord: 11e8. instance is created from the logging message.

Logging messages are subjected to a dispatch mechanism through the use
of 'handlers', which are instances of subclasses of the *note Handler:
169d. class.  Handlers are responsible for ensuring that a logged
message (in the form of a *note LogRecord: 11e8.) ends up in a
particular location (or set of locations) which is useful for the target
audience for that message (such as end users, support desk staff, system
administrators, developers).  Handlers are passed *note LogRecord: 11e8.
instances intended for particular destinations.  Each logger can have
zero, one or more handlers associated with it (via the *note
addHandler(): 313c. method of *note Logger: d48.).  In addition to any
handlers directly associated with a logger, 'all handlers associated
with all ancestors of the logger' are called to dispatch the message
(unless the 'propagate' flag for a logger is set to a false value, at
which point the passing to ancestor handlers stops).

Just as for loggers, handlers can have levels associated with them.  A
handler’s level acts as a filter in the same way as a logger’s level
does.  If a handler decides to actually dispatch an event, the *note
emit(): 315c. method is used to send the message to its destination.
Most user-defined subclasses of *note Handler: 169d. will need to
override this *note emit(): 315c.

* Menu:

* Custom Levels::


File: python.info,  Node: Custom Levels,  Up: Logging Levels<2>

9.8.3.1 Custom Levels
.....................

Defining your own levels is possible, but should not be necessary, as
the existing levels have been chosen on the basis of practical
experience.  However, if you are convinced that you need custom levels,
great care should be exercised when doing this, and it is possibly 'a
very bad idea to define custom levels if you are developing a library'.
That’s because if multiple library authors all define their own custom
levels, there is a chance that the logging output from such multiple
libraries used together will be difficult for the using developer to
control and/or interpret, because a given numeric value might mean
different things for different libraries.


File: python.info,  Node: Useful Handlers,  Next: Exceptions raised during logging,  Prev: Logging Levels<2>,  Up: Logging HOWTO

9.8.4 Useful Handlers
---------------------

In addition to the base *note Handler: 169d. class, many useful
subclasses are provided:

  1. *note StreamHandler: 1400. instances send messages to streams
     (file-like objects).

  2. *note FileHandler: 1c3b. instances send messages to disk files.

  3. *note BaseRotatingHandler: 31c4. is the base class for handlers
     that rotate log files at a certain point.  It is not meant to be
     instantiated directly.  Instead, use *note RotatingFileHandler:
     1929. or *note TimedRotatingFileHandler: 1163.

  4. *note RotatingFileHandler: 1929. instances send messages to disk
     files, with support for maximum log file sizes and log file
     rotation.

  5. *note TimedRotatingFileHandler: 1163. instances send messages to
     disk files, rotating the log file at certain timed intervals.

  6. *note SocketHandler: 1164. instances send messages to TCP/IP
     sockets.  Since 3.4, Unix domain sockets are also supported.

  7. *note DatagramHandler: 1165. instances send messages to UDP
     sockets.  Since 3.4, Unix domain sockets are also supported.

  8. *note SMTPHandler: 189a. instances send messages to a designated
     email address.

  9. *note SysLogHandler: 86d. instances send messages to a Unix syslog
     daemon, possibly on a remote machine.

  10. *note NTEventLogHandler: 31ea. instances send messages to a
     Windows NT/2000/XP event log.

  11. *note MemoryHandler: 31a3. instances send messages to a buffer in
     memory, which is flushed whenever specific criteria are met.

  12. *note HTTPHandler: 102e. instances send messages to an HTTP server
     using either ‘GET’ or ‘POST’ semantics.

  13. *note WatchedFileHandler: 31c0. instances watch the file they are
     logging to.  If the file changes, it is closed and reopened using
     the file name.  This handler is only useful on Unix-like systems;
     Windows does not support the underlying mechanism used.

  14. *note QueueHandler: 1b49. instances send messages to a queue, such
     as those implemented in the *note queue: bb. or *note
     multiprocessing: 98. modules.

  15. *note NullHandler: 148c. instances do nothing with error messages.
     They are used by library developers who want to use logging, but
     want to avoid the “No handlers could be found for logger 'XXX'”
     message which can be displayed if the library user has not
     configured logging.  See *note Configuring Logging for a Library:
     31bd. for more information.

Added in version 3.1: The *note NullHandler: 148c. class.

Added in version 3.2: The *note QueueHandler: 1b49. class.

The *note NullHandler: 148c, *note StreamHandler: 1400. and *note
FileHandler: 1c3b. classes are defined in the core logging package.  The
other handlers are defined in a sub-module, *note logging.handlers: 8d.
(There is also another sub-module, *note logging.config: 8c, for
configuration functionality.)

Logged messages are formatted for presentation through instances of the
*note Formatter: 169e. class.  They are initialized with a format string
suitable for use with the % operator and a dictionary.

For formatting multiple messages in a batch, instances of *note
BufferingFormatter: 3165. can be used.  In addition to the format string
(which is applied to each message in the batch), there is provision for
header and trailer format strings.

When filtering based on logger level and/or handler level is not enough,
instances of *note Filter: 1403. can be added to both *note Logger: d48.
and *note Handler: 169d. instances (through their *note addFilter():
3155. method).  Before deciding to process a message further, both
loggers and handlers consult all their filters for permission.  If any
filter returns a false value, the message is not processed further.

The basic *note Filter: 1403. functionality allows filtering by specific
logger name.  If this feature is used, messages sent to the named logger
and its children are allowed through the filter, and all others dropped.


File: python.info,  Node: Exceptions raised during logging,  Next: Using arbitrary objects as messages,  Prev: Useful Handlers,  Up: Logging HOWTO

9.8.5 Exceptions raised during logging
--------------------------------------

The logging package is designed to swallow exceptions which occur while
logging in production.  This is so that errors which occur while
handling logging events - such as logging misconfiguration, network or
other similar errors - do not cause the application using logging to
terminate prematurely.

*note SystemExit: f3e. and *note KeyboardInterrupt: bc7. exceptions are
never swallowed.  Other exceptions which occur during the *note emit():
315c. method of a *note Handler: 169d. subclass are passed to its *note
handleError(): 315b. method.

The default implementation of *note handleError(): 315b. in *note
Handler: 169d. checks to see if a module-level variable, *note
raiseExceptions: 1401, is set.  If set, a traceback is printed to *note
sys.stderr: b35.  If not set, the exception is swallowed.

     Nota: The default value of *note raiseExceptions: 1401. is ‘True’.
     This is because during development, you typically want to be
     notified of any exceptions that occur.  It’s advised that you set
     *note raiseExceptions: 1401. to ‘False’ for production usage.


File: python.info,  Node: Using arbitrary objects as messages,  Next: Optimization,  Prev: Exceptions raised during logging,  Up: Logging HOWTO

9.8.6 Using arbitrary objects as messages
-----------------------------------------

In the preceding sections and examples, it has been assumed that the
message passed when logging the event is a string.  However, this is not
the only possibility.  You can pass an arbitrary object as a message,
and its *note __str__(): 831. method will be called when the logging
system needs to convert it to a string representation.  In fact, if you
want to, you can avoid computing a string representation altogether -
for example, the *note SocketHandler: 1164. emits an event by pickling
it and sending it over the wire.


File: python.info,  Node: Optimization,  Next: Other resources,  Prev: Using arbitrary objects as messages,  Up: Logging HOWTO

9.8.7 Optimization
------------------

Formatting of message arguments is deferred until it cannot be avoided.
However, computing the arguments passed to the logging method can also
be expensive, and you may want to avoid doing it if the logger will just
throw away your event.  To decide what to do, you can call the *note
isEnabledFor(): 14fe. method which takes a level argument and returns
true if the event would be created by the Logger for that level of call.
You can write code like this:

     if logger.isEnabledFor(logging.DEBUG):
         logger.debug('Message with %s, %s', expensive_func1(),
                                             expensive_func2())

so that if the logger’s threshold is set above ‘DEBUG’, the calls to
‘expensive_func1’ and ‘expensive_func2’ are never made.

     Nota: In some cases, *note isEnabledFor(): 14fe. can itself be more
     expensive than you’d like (e.g.  for deeply nested loggers where an
     explicit level is only set high up in the logger hierarchy).  In
     such cases (or if you want to avoid calling a method in tight
     loops), you can cache the result of a call to *note isEnabledFor():
     14fe. in a local or instance variable, and use that instead of
     calling the method each time.  Such a cached value would only need
     to be recomputed when the logging configuration changes dynamically
     while the application is running (which is not all that common).

There are other optimizations which can be made for specific
applications which need more precise control over what logging
information is collected.  Here’s a list of things you can do to avoid
processing during logging which you don’t need:

What you don’t want to collect                            How to avoid collecting it
                                                          
------------------------------------------------------------------------------------------------------------------
                                                          
Information about where calls were made from.             Set ‘logging._srcfile’ to ‘None’.  This avoids
                                                          calling *note sys._getframe(): 8f1, which may help to
                                                          speed up your code in environments like PyPy (which
                                                          can’t speed up code that uses
                                                          *note sys._getframe(): 8f1.).
                                                          
                                                          
Threading information.                                    Set ‘logging.logThreads’ to ‘False’.
                                                          
                                                          
Current process ID (*note os.getpid(): 2fe6.)             Set ‘logging.logProcesses’ to ‘False’.
                                                          
                                                          
Current process name when using ‘multiprocessing’ to      Set ‘logging.logMultiprocessing’ to ‘False’.
manage multiple processes.                                

Current *note asyncio.Task: 1c7. name when using          Set ‘logging.logAsyncioTasks’ to ‘False’.
‘asyncio’.                                                

Also note that the core logging module only includes the basic handlers.
If you don’t import *note logging.handlers: 8d. and *note
logging.config: 8c, they won’t take up any memory.


File: python.info,  Node: Other resources,  Prev: Optimization,  Up: Logging HOWTO

9.8.8 Other resources
---------------------

Vedi anche
..........

Module *note logging: 8b.

     API reference for the logging module.

Module *note logging.config: 8c.

     Configuration API for the logging module.

Module *note logging.handlers: 8d.

     Useful handlers included with the logging module.

*note A logging cookbook: 13ff.


File: python.info,  Node: Logging Cookbook,  Next: Regular Expression HOWTO,  Prev: Logging HOWTO,  Up: Python HOWTOs

9.9 Logging Cookbook
====================


Author: Vinay Sajip <vinay_sajip at red-dove dot com>

This page contains a number of recipes related to logging, which have
been found useful in the past.  For links to tutorial and reference
information, please see *note Other resources: 573c.

* Menu:

* Using logging in multiple modules::
* Logging from multiple threads::
* Multiple handlers and formatters::
* Logging to multiple destinations::
* Custom handling of levels::
* Configuration server example::
* Dealing with handlers that block::
* Sending and receiving logging events across a network::
* Adding contextual information to your logging output::
* Use of contextvars::
* Imparting contextual information in handlers::
* Logging to a single file from multiple processes::
* Using file rotation::
* Use of alternative formatting styles::
* Customizing LogRecord::
* Subclassing QueueHandler and QueueListener- a ZeroMQ example::
* Subclassing QueueHandler and QueueListener- a pynng example::
* An example dictionary-based configuration::
* Using a rotator and namer to customize log rotation processing::
* A more elaborate multiprocessing example::
* Inserting a BOM into messages sent to a SysLogHandler::
* Implementing structured logging::
* Customizing handlers with dictConfig(): Customizing handlers with dictConfig.
* Using particular formatting styles throughout your application::
* Configuring filters with dictConfig(): Configuring filters with dictConfig.
* Customized exception formatting::
* Speaking logging messages::
* Buffering logging messages and outputting them conditionally::
* Sending logging messages to email, with buffering: Sending logging messages to email with buffering.
* Formatting times using UTC (GMT) via configuration: Formatting times using UTC GMT via configuration.
* Using a context manager for selective logging::
* A CLI application starter template::
* A Qt GUI for logging::
* Logging to syslog with RFC5424 support::
* How to treat a logger like an output stream::
* How to uniformly handle newlines in logging output::
* Patterns to avoid::
* Other resources: Other resources<2>.


File: python.info,  Node: Using logging in multiple modules,  Next: Logging from multiple threads,  Up: Logging Cookbook

9.9.1 Using logging in multiple modules
---------------------------------------

Multiple calls to ‘logging.getLogger('someLogger')’ return a reference
to the same logger object.  This is true not only within the same
module, but also across modules as long as it is in the same Python
interpreter process.  It is true for references to the same object;
additionally, application code can define and configure a parent logger
in one module and create (but not configure) a child logger in a
separate module, and all logger calls to the child will pass up to the
parent.  Here is a main module:

     import logging
     import auxiliary_module

     # create logger with 'spam_application'
     logger = logging.getLogger('spam_application')
     logger.setLevel(logging.DEBUG)
     # create file handler which logs even debug messages
     fh = logging.FileHandler('spam.log')
     fh.setLevel(logging.DEBUG)
     # create console handler with a higher log level
     ch = logging.StreamHandler()
     ch.setLevel(logging.ERROR)
     # create formatter and add it to the handlers
     formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
     fh.setFormatter(formatter)
     ch.setFormatter(formatter)
     # add the handlers to the logger
     logger.addHandler(fh)
     logger.addHandler(ch)

     logger.info('creating an instance of auxiliary_module.Auxiliary')
     a = auxiliary_module.Auxiliary()
     logger.info('created an instance of auxiliary_module.Auxiliary')
     logger.info('calling auxiliary_module.Auxiliary.do_something')
     a.do_something()
     logger.info('finished auxiliary_module.Auxiliary.do_something')
     logger.info('calling auxiliary_module.some_function()')
     auxiliary_module.some_function()
     logger.info('done with auxiliary_module.some_function()')

Here is the auxiliary module:

     import logging

     # create logger
     module_logger = logging.getLogger('spam_application.auxiliary')

     class Auxiliary:
         def __init__(self):
             self.logger = logging.getLogger('spam_application.auxiliary.Auxiliary')
             self.logger.info('creating an instance of Auxiliary')

         def do_something(self):
             self.logger.info('doing something')
             a = 1 + 1
             self.logger.info('done doing something')

     def some_function():
         module_logger.info('received a call to "some_function"')

The output looks like this:

     2005-03-23 23:47:11,663 - spam_application - INFO -
        creating an instance of auxiliary_module.Auxiliary
     2005-03-23 23:47:11,665 - spam_application.auxiliary.Auxiliary - INFO -
        creating an instance of Auxiliary
     2005-03-23 23:47:11,665 - spam_application - INFO -
        created an instance of auxiliary_module.Auxiliary
     2005-03-23 23:47:11,668 - spam_application - INFO -
        calling auxiliary_module.Auxiliary.do_something
     2005-03-23 23:47:11,668 - spam_application.auxiliary.Auxiliary - INFO -
        doing something
     2005-03-23 23:47:11,669 - spam_application.auxiliary.Auxiliary - INFO -
        done doing something
     2005-03-23 23:47:11,670 - spam_application - INFO -
        finished auxiliary_module.Auxiliary.do_something
     2005-03-23 23:47:11,671 - spam_application - INFO -
        calling auxiliary_module.some_function()
     2005-03-23 23:47:11,672 - spam_application.auxiliary - INFO -
        received a call to 'some_function'
     2005-03-23 23:47:11,673 - spam_application - INFO -
        done with auxiliary_module.some_function()


File: python.info,  Node: Logging from multiple threads,  Next: Multiple handlers and formatters,  Prev: Using logging in multiple modules,  Up: Logging Cookbook

9.9.2 Logging from multiple threads
-----------------------------------

Logging from multiple threads requires no special effort.  The following
example shows logging from the main (initial) thread and another thread:

     import logging
     import threading
     import time

     def worker(arg):
         while not arg['stop']:
             logging.debug('Hi from myfunc')
             time.sleep(0.5)

     def main():
         logging.basicConfig(level=logging.DEBUG, format='%(relativeCreated)6d %(threadName)s %(message)s')
         info = {'stop': False}
         thread = threading.Thread(target=worker, args=(info,))
         thread.start()
         while True:
             try:
                 logging.debug('Hello from main')
                 time.sleep(0.75)
             except KeyboardInterrupt:
                 info['stop'] = True
                 break
         thread.join()

     if __name__ == '__main__':
         main()

When run, the script should print something like the following:

        0 Thread-1 Hi from myfunc
        3 MainThread Hello from main
      505 Thread-1 Hi from myfunc
      755 MainThread Hello from main
     1007 Thread-1 Hi from myfunc
     1507 MainThread Hello from main
     1508 Thread-1 Hi from myfunc
     2010 Thread-1 Hi from myfunc
     2258 MainThread Hello from main
     2512 Thread-1 Hi from myfunc
     3009 MainThread Hello from main
     3013 Thread-1 Hi from myfunc
     3515 Thread-1 Hi from myfunc
     3761 MainThread Hello from main
     4017 Thread-1 Hi from myfunc
     4513 MainThread Hello from main
     4518 Thread-1 Hi from myfunc

This shows the logging output interspersed as one might expect.  This
approach works for more threads than shown here, of course.


File: python.info,  Node: Multiple handlers and formatters,  Next: Logging to multiple destinations,  Prev: Logging from multiple threads,  Up: Logging Cookbook

9.9.3 Multiple handlers and formatters
--------------------------------------

Loggers are plain Python objects.  The *note addHandler(): 313c. method
has no minimum or maximum quota for the number of handlers you may add.
Sometimes it will be beneficial for an application to log all messages
of all severities to a text file while simultaneously logging errors or
above to the console.  To set this up, simply configure the appropriate
handlers.  The logging calls in the application code will remain
unchanged.  Here is a slight modification to the previous simple
module-based configuration example:

     import logging

     logger = logging.getLogger('simple_example')
     logger.setLevel(logging.DEBUG)
     # create file handler which logs even debug messages
     fh = logging.FileHandler('spam.log')
     fh.setLevel(logging.DEBUG)
     # create console handler with a higher log level
     ch = logging.StreamHandler()
     ch.setLevel(logging.ERROR)
     # create formatter and add it to the handlers
     formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
     ch.setFormatter(formatter)
     fh.setFormatter(formatter)
     # add the handlers to logger
     logger.addHandler(ch)
     logger.addHandler(fh)

     # 'application' code
     logger.debug('debug message')
     logger.info('info message')
     logger.warning('warn message')
     logger.error('error message')
     logger.critical('critical message')

Notice that the “application” code does not care about multiple
handlers.  All that changed was the addition and configuration of a new
handler named 'fh'.

The ability to create new handlers with higher- or lower-severity
filters can be very helpful when writing and testing an application.
Instead of using many ‘print’ statements for debugging, use
‘logger.debug’: Unlike the print statements, which you will have to
delete or comment out later, the logger.debug statements can remain
intact in the source code and remain dormant until you need them again.
At that time, the only change that needs to happen is to modify the
severity level of the logger and/or handler to debug.


File: python.info,  Node: Logging to multiple destinations,  Next: Custom handling of levels,  Prev: Multiple handlers and formatters,  Up: Logging Cookbook

9.9.4 Logging to multiple destinations
--------------------------------------

Let’s say you want to log to console and file with different message
formats and in differing circumstances.  Say you want to log messages
with levels of DEBUG and higher to file, and those messages at level
INFO and higher to the console.  Let’s also assume that the file should
contain timestamps, but the console messages should not.  Here’s how you
can achieve this:

     import logging

     # set up logging to file - see previous section for more details
     logging.basicConfig(level=logging.DEBUG,
                         format='%(asctime)s %(name)-12s %(levelname)-8s %(message)s',
                         datefmt='%m-%d %H:%M',
                         filename='/tmp/myapp.log',
                         filemode='w')
     # define a Handler which writes INFO messages or higher to the sys.stderr
     console = logging.StreamHandler()
     console.setLevel(logging.INFO)
     # set a format which is simpler for console use
     formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s')
     # tell the handler to use this format
     console.setFormatter(formatter)
     # add the handler to the root logger
     logging.getLogger('').addHandler(console)

     # Now, we can log to the root logger, or any other logger. First the root...
     logging.info('Jackdaws love my big sphinx of quartz.')

     # Now, define a couple of other loggers which might represent areas in your
     # application:

     logger1 = logging.getLogger('myapp.area1')
     logger2 = logging.getLogger('myapp.area2')

     logger1.debug('Quick zephyrs blow, vexing daft Jim.')
     logger1.info('How quickly daft jumping zebras vex.')
     logger2.warning('Jail zesty vixen who grabbed pay from quack.')
     logger2.error('The five boxing wizards jump quickly.')

When you run this, on the console you will see

     root        : INFO     Jackdaws love my big sphinx of quartz.
     myapp.area1 : INFO     How quickly daft jumping zebras vex.
     myapp.area2 : WARNING  Jail zesty vixen who grabbed pay from quack.
     myapp.area2 : ERROR    The five boxing wizards jump quickly.

and in the file you will see something like

     10-22 22:19 root         INFO     Jackdaws love my big sphinx of quartz.
     10-22 22:19 myapp.area1  DEBUG    Quick zephyrs blow, vexing daft Jim.
     10-22 22:19 myapp.area1  INFO     How quickly daft jumping zebras vex.
     10-22 22:19 myapp.area2  WARNING  Jail zesty vixen who grabbed pay from quack.
     10-22 22:19 myapp.area2  ERROR    The five boxing wizards jump quickly.

As you can see, the DEBUG message only shows up in the file.  The other
messages are sent to both destinations.

This example uses console and file handlers, but you can use any number
and combination of handlers you choose.

Note that the above choice of log filename ‘/tmp/myapp.log’ implies use
of a standard location for temporary files on POSIX systems.  On
Windows, you may need to choose a different directory name for the log -
just ensure that the directory exists and that you have the permissions
to create and update files in it.


File: python.info,  Node: Custom handling of levels,  Next: Configuration server example,  Prev: Logging to multiple destinations,  Up: Logging Cookbook

9.9.5 Custom handling of levels
-------------------------------

Sometimes, you might want to do something slightly different from the
standard handling of levels in handlers, where all levels above a
threshold get processed by a handler.  To do this, you need to use
filters.  Let’s look at a scenario where you want to arrange things as
follows:

   * Send messages of severity ‘INFO’ and ‘WARNING’ to ‘sys.stdout’

   * Send messages of severity ‘ERROR’ and above to ‘sys.stderr’

   * Send messages of severity ‘DEBUG’ and above to file ‘app.log’

Suppose you configure logging with the following JSON:

     {
         "version": 1,
         "disable_existing_loggers": false,
         "formatters": {
             "simple": {
                 "format": "%(levelname)-8s - %(message)s"
             }
         },
         "handlers": {
             "stdout": {
                 "class": "logging.StreamHandler",
                 "level": "INFO",
                 "formatter": "simple",
                 "stream": "ext://sys.stdout"
             },
             "stderr": {
                 "class": "logging.StreamHandler",
                 "level": "ERROR",
                 "formatter": "simple",
                 "stream": "ext://sys.stderr"
             },
             "file": {
                 "class": "logging.FileHandler",
                 "formatter": "simple",
                 "filename": "app.log",
                 "mode": "w"
             }
         },
         "root": {
             "level": "DEBUG",
             "handlers": [
                 "stderr",
                 "stdout",
                 "file"
             ]
         }
     }

This configuration does 'almost' what we want, except that ‘sys.stdout’
would show messages of severity ‘ERROR’ and only events of this severity
and higher will be tracked as well as ‘INFO’ and ‘WARNING’ messages.  To
prevent this, we can set up a filter which excludes those messages and
add it to the relevant handler.  This can be configured by adding a
‘filters’ section parallel to ‘formatters’ and ‘handlers’:

     {
         "filters": {
             "warnings_and_below": {
                 "()" : "__main__.filter_maker",
                 "level": "WARNING"
             }
         }
     }

and changing the section on the ‘stdout’ handler to add it:

     {
         "stdout": {
             "class": "logging.StreamHandler",
             "level": "INFO",
             "formatter": "simple",
             "stream": "ext://sys.stdout",
             "filters": ["warnings_and_below"]
         }
     }

A filter is just a function, so we can define the ‘filter_maker’ (a
factory function) as follows:

     def filter_maker(level):
         level = getattr(logging, level)

         def filter(record):
             return record.levelno <= level

         return filter

This converts the string argument passed in to a numeric level, and
returns a function which only returns ‘True’ if the level of the passed
in record is at or below the specified level.  Note that in this example
I have defined the ‘filter_maker’ in a test script ‘main.py’ that I run
from the command line, so its module will be ‘__main__’ - hence the
‘__main__.filter_maker’ in the filter configuration.  You will need to
change that if you define it in a different module.

With the filter added, we can run ‘main.py’, which in full is:

     import json
     import logging
     import logging.config

     CONFIG = '''
     {
         "version": 1,
         "disable_existing_loggers": false,
         "formatters": {
             "simple": {
                 "format": "%(levelname)-8s - %(message)s"
             }
         },
         "filters": {
             "warnings_and_below": {
                 "()" : "__main__.filter_maker",
                 "level": "WARNING"
             }
         },
         "handlers": {
             "stdout": {
                 "class": "logging.StreamHandler",
                 "level": "INFO",
                 "formatter": "simple",
                 "stream": "ext://sys.stdout",
                 "filters": ["warnings_and_below"]
             },
             "stderr": {
                 "class": "logging.StreamHandler",
                 "level": "ERROR",
                 "formatter": "simple",
                 "stream": "ext://sys.stderr"
             },
             "file": {
                 "class": "logging.FileHandler",
                 "formatter": "simple",
                 "filename": "app.log",
                 "mode": "w"
             }
         },
         "root": {
             "level": "DEBUG",
             "handlers": [
                 "stderr",
                 "stdout",
                 "file"
             ]
         }
     }
     '''

     def filter_maker(level):
         level = getattr(logging, level)

         def filter(record):
             return record.levelno <= level

         return filter

     logging.config.dictConfig(json.loads(CONFIG))
     logging.debug('A DEBUG message')
     logging.info('An INFO message')
     logging.warning('A WARNING message')
     logging.error('An ERROR message')
     logging.critical('A CRITICAL message')

And after running it like this:

     python main.py 2>stderr.log >stdout.log

We can see the results are as expected:

     $ more *.log
     ::::::::::::::
     app.log
     ::::::::::::::
     DEBUG    - A DEBUG message
     INFO     - An INFO message
     WARNING  - A WARNING message
     ERROR    - An ERROR message
     CRITICAL - A CRITICAL message
     ::::::::::::::
     stderr.log
     ::::::::::::::
     ERROR    - An ERROR message
     CRITICAL - A CRITICAL message
     ::::::::::::::
     stdout.log
     ::::::::::::::
     INFO     - An INFO message
     WARNING  - A WARNING message


File: python.info,  Node: Configuration server example,  Next: Dealing with handlers that block,  Prev: Custom handling of levels,  Up: Logging Cookbook

9.9.6 Configuration server example
----------------------------------

Here is an example of a module using the logging configuration server:

     import logging
     import logging.config
     import time
     import os

     # read initial config file
     logging.config.fileConfig('logging.conf')

     # create and start listener on port 9999
     t = logging.config.listen(9999)
     t.start()

     logger = logging.getLogger('simpleExample')

     try:
         # loop through logging calls to see the difference
         # new configurations make, until Ctrl+C is pressed
         while True:
             logger.debug('debug message')
             logger.info('info message')
             logger.warning('warn message')
             logger.error('error message')
             logger.critical('critical message')
             time.sleep(5)
     except KeyboardInterrupt:
         # cleanup
         logging.config.stopListening()
         t.join()

And here is a script that takes a filename and sends that file to the
server, properly preceded with the binary-encoded length, as the new
logging configuration:

     #!/usr/bin/env python
     import socket, sys, struct

     with open(sys.argv[1], 'rb') as f:
         data_to_send = f.read()

     HOST = 'localhost'
     PORT = 9999
     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     print('connecting...')
     s.connect((HOST, PORT))
     print('sending config...')
     s.send(struct.pack('>L', len(data_to_send)))
     s.send(data_to_send)
     s.close()
     print('complete')


File: python.info,  Node: Dealing with handlers that block,  Next: Sending and receiving logging events across a network,  Prev: Configuration server example,  Up: Logging Cookbook

9.9.7 Dealing with handlers that block
--------------------------------------

Sometimes you have to get your logging handlers to do their work without
blocking the thread you’re logging from.  This is common in web
applications, though of course it also occurs in other scenarios.

A common culprit which demonstrates sluggish behaviour is the *note
SMTPHandler: 189a.: sending emails can take a long time, for a number of
reasons outside the developer’s control (for example, a poorly
performing mail or network infrastructure).  But almost any
network-based handler can block: Even a *note SocketHandler: 1164.
operation may do a DNS query under the hood which is too slow (and this
query can be deep in the socket library code, below the Python layer,
and outside your control).

One solution is to use a two-part approach.  For the first part, attach
only a *note QueueHandler: 1b49. to those loggers which are accessed
from performance-critical threads.  They simply write to their queue,
which can be sized to a large enough capacity or initialized with no
upper bound to their size.  The write to the queue will typically be
accepted quickly, though you will probably need to catch the *note
queue.Full: 3653. exception as a precaution in your code.  If you are a
library developer who has performance-critical threads in their code, be
sure to document this (together with a suggestion to attach only
‘QueueHandlers’ to your loggers) for the benefit of other developers who
will use your code.

The second part of the solution is *note QueueListener: 242, which has
been designed as the counterpart to *note QueueHandler: 1b49.  A *note
QueueListener: 242. is very simple: it’s passed a queue and some
handlers, and it fires up an internal thread which listens to its queue
for LogRecords sent from ‘QueueHandlers’ (or any other source of
‘LogRecords’, for that matter).  The ‘LogRecords’ are removed from the
queue and passed to the handlers for processing.

The advantage of having a separate *note QueueListener: 242. class is
that you can use the same instance to service multiple ‘QueueHandlers’.
This is more resource-friendly than, say, having threaded versions of
the existing handler classes, which would eat up one thread per handler
for no particular benefit.

An example of using these two classes follows (imports omitted):

     que = queue.Queue(-1)  # no limit on size
     queue_handler = QueueHandler(que)
     handler = logging.StreamHandler()
     listener = QueueListener(que, handler)
     root = logging.getLogger()
     root.addHandler(queue_handler)
     formatter = logging.Formatter('%(threadName)s: %(message)s')
     handler.setFormatter(formatter)
     listener.start()
     # The log output will display the thread which generated
     # the event (the main thread) rather than the internal
     # thread which monitors the internal queue. This is what
     # you want to happen.
     root.warning('Look out!')
     listener.stop()

which, when run, will produce:

     MainThread: Look out!

     Nota: Although the earlier discussion wasn’t specifically talking
     about async code, but rather about slow logging handlers, it should
     be noted that when logging from async code, network and even file
     handlers could lead to problems (blocking the event loop) because
     some logging is done from *note asyncio: b. internals.  It might be
     best, if any async code is used in an application, to use the above
     approach for logging, so that any blocking code runs only in the
     ‘QueueListener’ thread.

Cambiato nella versione 3.5: Prior to Python 3.5, the *note
QueueListener: 242. always passed every message received from the queue
to every handler it was initialized with.  (This was because it was
assumed that level filtering was all done on the other side, where the
queue is filled.)  From 3.5 onwards, this behaviour can be changed by
passing a keyword argument ‘respect_handler_level=True’ to the
listener’s constructor.  When this is done, the listener compares the
level of each message with the handler’s level, and only passes a
message to a handler if it’s appropriate to do so.

Cambiato nella versione 3.14: The *note QueueListener: 242. can be
started (and stopped) via the *note with: 186. statement.  For example:

     with QueueListener(que, handler) as listener:
         # The queue listener automatically starts
         # when the 'with' block is entered.
         pass
     # The queue listener automatically stops once
     # the 'with' block is exited.


File: python.info,  Node: Sending and receiving logging events across a network,  Next: Adding contextual information to your logging output,  Prev: Dealing with handlers that block,  Up: Logging Cookbook

9.9.8 Sending and receiving logging events across a network
-----------------------------------------------------------

Let’s say you want to send logging events across a network, and handle
them at the receiving end.  A simple way of doing this is attaching a
*note SocketHandler: 1164. instance to the root logger at the sending
end:

     import logging, logging.handlers

     rootLogger = logging.getLogger('')
     rootLogger.setLevel(logging.DEBUG)
     socketHandler = logging.handlers.SocketHandler('localhost',
                         logging.handlers.DEFAULT_TCP_LOGGING_PORT)
     # don't bother with a formatter, since a socket handler sends the event as
     # an unformatted pickle
     rootLogger.addHandler(socketHandler)

     # Now, we can log to the root logger, or any other logger. First the root...
     logging.info('Jackdaws love my big sphinx of quartz.')

     # Now, define a couple of other loggers which might represent areas in your
     # application:

     logger1 = logging.getLogger('myapp.area1')
     logger2 = logging.getLogger('myapp.area2')

     logger1.debug('Quick zephyrs blow, vexing daft Jim.')
     logger1.info('How quickly daft jumping zebras vex.')
     logger2.warning('Jail zesty vixen who grabbed pay from quack.')
     logger2.error('The five boxing wizards jump quickly.')

At the receiving end, you can set up a receiver using the *note
socketserver: d2. module.  Here is a basic working example:

     import pickle
     import logging
     import logging.handlers
     import socketserver
     import struct


     class LogRecordStreamHandler(socketserver.StreamRequestHandler):
         """Handler for a streaming logging request.

         This basically logs the record using whatever logging policy is
         configured locally.
         """

         def handle(self):
             """
             Handle multiple requests - each expected to be a 4-byte length,
             followed by the LogRecord in pickle format. Logs the record
             according to whatever policy is configured locally.
             """
             while True:
                 chunk = self.connection.recv(4)
                 if len(chunk) < 4:
                     break
                 slen = struct.unpack('>L', chunk)[0]
                 chunk = self.connection.recv(slen)
                 while len(chunk) < slen:
                     chunk = chunk + self.connection.recv(slen - len(chunk))
                 obj = self.unPickle(chunk)
                 record = logging.makeLogRecord(obj)
                 self.handleLogRecord(record)

         def unPickle(self, data):
             return pickle.loads(data)

         def handleLogRecord(self, record):
             # if a name is specified, we use the named logger rather than the one
             # implied by the record.
             if self.server.logname is not None:
                 name = self.server.logname
             else:
                 name = record.name
             logger = logging.getLogger(name)
             # N.B. EVERY record gets logged. This is because Logger.handle
             # is normally called AFTER logger-level filtering. If you want
             # to do filtering, do it at the client end to save wasting
             # cycles and network bandwidth!
             logger.handle(record)

     class LogRecordSocketReceiver(socketserver.ThreadingTCPServer):
         """
         Simple TCP socket-based logging receiver suitable for testing.
         """

         allow_reuse_address = True

         def __init__(self, host='localhost',
                      port=logging.handlers.DEFAULT_TCP_LOGGING_PORT,
                      handler=LogRecordStreamHandler):
             socketserver.ThreadingTCPServer.__init__(self, (host, port), handler)
             self.abort = 0
             self.timeout = 1
             self.logname = None

         def serve_until_stopped(self):
             import select
             abort = 0
             while not abort:
                 rd, wr, ex = select.select([self.socket.fileno()],
                                            [], [],
                                            self.timeout)
                 if rd:
                     self.handle_request()
                 abort = self.abort

     def main():
         logging.basicConfig(
             format='%(relativeCreated)5d %(name)-15s %(levelname)-8s %(message)s')
         tcpserver = LogRecordSocketReceiver()
         print('About to start TCP server...')
         tcpserver.serve_until_stopped()

     if __name__ == '__main__':
         main()

First run the server, and then the client.  On the client side, nothing
is printed on the console; on the server side, you should see something
like:

     About to start TCP server...
        59 root            INFO     Jackdaws love my big sphinx of quartz.
        59 myapp.area1     DEBUG    Quick zephyrs blow, vexing daft Jim.
        69 myapp.area1     INFO     How quickly daft jumping zebras vex.
        69 myapp.area2     WARNING  Jail zesty vixen who grabbed pay from quack.
        69 myapp.area2     ERROR    The five boxing wizards jump quickly.

Note that there are some security issues with pickle in some scenarios.
If these affect you, you can use an alternative serialization scheme by
overriding the *note makePickle(): 31db. method and implementing your
alternative there, as well as adapting the above script to use your
alternative serialization.

* Menu:

* Running a logging socket listener in production::


File: python.info,  Node: Running a logging socket listener in production,  Up: Sending and receiving logging events across a network

9.9.8.1 Running a logging socket listener in production
.......................................................

To run a logging listener in production, you may need to use a
process-management tool such as Supervisor(1).  Here is a Gist(2) which
provides the bare-bones files to run the above functionality using
Supervisor.  It consists of the following files:

File                          Purpose
                              
---------------------------------------------------------------------------------------
                              
‘prepare.sh’                  A Bash script to prepare the environment for testing
                              
                              
‘supervisor.conf’             The Supervisor configuration file, which has entries
                              for the listener and a multi-process web application
                              
                              
‘ensure_app.sh’               A Bash script to ensure that Supervisor is running
                              with the above configuration
                              
                              
‘log_listener.py’             The socket listener program which receives log events
                              and records them to a file
                              
                              
‘main.py’                     A simple web application which performs logging via a
                              socket connected to the listener
                              
                              
‘webapp.json’                 A JSON configuration file for the web application
                              
                              
‘client.py’                   A Python script to exercise the web application
                              

The web application uses Gunicorn(3), which is a popular web application
server that starts multiple worker processes to handle requests.  This
example setup shows how the workers can write to the same log file
without conflicting with one another — they all go through the socket
listener.

To test these files, do the following in a POSIX environment:

  1. Download the Gist(4) as a ZIP archive using the Download ZIP
     button.

  2. Unzip the above files from the archive into a scratch directory.

  3. In the scratch directory, run ‘bash prepare.sh’ to get things
     ready.  This creates a ‘run’ subdirectory to contain
     Supervisor-related and log files, and a ‘venv’ subdirectory to
     contain a virtual environment into which ‘bottle’, ‘gunicorn’ and
     ‘supervisor’ are installed.

  4. Run ‘bash ensure_app.sh’ to ensure that Supervisor is running with
     the above configuration.

  5. Run ‘venv/bin/python client.py’ to exercise the web application,
     which will lead to records being written to the log.

  6. Inspect the log files in the ‘run’ subdirectory.  You should see
     the most recent log lines in files matching the pattern ‘app.log*’.
     They won’t be in any particular order, since they have been handled
     concurrently by different worker processes in a non-deterministic
     way.

  7. You can shut down the listener and the web application by running
     ‘venv/bin/supervisorctl -c supervisor.conf shutdown’.

You may need to tweak the configuration files in the unlikely event that
the configured ports clash with something else in your test environment.

The default configuration uses a TCP socket on port 9020.  You can use a
Unix Domain socket instead of a TCP socket by doing the following:

  1. In ‘listener.json’, add a ‘socket’ key with the path to the domain
     socket you want to use.  If this key is present, the listener
     listens on the corresponding domain socket and not on a TCP socket
     (the ‘port’ key is ignored).

  2. In ‘webapp.json’, change the socket handler configuration
     dictionary so that the ‘host’ value is the path to the domain
     socket, and set the ‘port’ value to ‘null’.

   ---------- Footnotes ----------

   (1) http://supervisord.org/

   (2) https://gist.github.com/vsajip/4b227eeec43817465ca835ca66f75e2b

   (3) https://gunicorn.org/

   (4) https://gist.github.com/vsajip/4b227eeec43817465ca835ca66f75e2b


File: python.info,  Node: Adding contextual information to your logging output,  Next: Use of contextvars,  Prev: Sending and receiving logging events across a network,  Up: Logging Cookbook

9.9.9 Adding contextual information to your logging output
----------------------------------------------------------

Sometimes you want logging output to contain contextual information in
addition to the parameters passed to the logging call.  For example, in
a networked application, it may be desirable to log client-specific
information in the log (e.g.  remote client’s username, or IP address).
Although you could use the 'extra' parameter to achieve this, it’s not
always convenient to pass the information in this way.  While it might
be tempting to create *note Logger: d48. instances on a per-connection
basis, this is not a good idea because these instances are not garbage
collected.  While this is not a problem in practice, when the number of
*note Logger: d48. instances is dependent on the level of granularity
you want to use in logging an application, it could be hard to manage if
the number of *note Logger: d48. instances becomes effectively
unbounded.

* Menu:

* Using LoggerAdapters to impart contextual information::
* Using Filters to impart contextual information::


File: python.info,  Node: Using LoggerAdapters to impart contextual information,  Next: Using Filters to impart contextual information,  Up: Adding contextual information to your logging output

9.9.9.1 Using LoggerAdapters to impart contextual information
.............................................................

An easy way in which you can pass contextual information to be output
along with logging event information is to use the *note LoggerAdapter:
14fd. class.  This class is designed to look like a *note Logger: d48,
so that you can call *note debug(): 3143, *note info(): 316c, *note
warning(): 354, *note error(): 3180, *note exception(): 169b, *note
critical(): 3181. and *note log(): 3182.  These methods have the same
signatures as their counterparts in *note Logger: d48, so you can use
the two types of instances interchangeably.

When you create an instance of *note LoggerAdapter: 14fd, you pass it a
*note Logger: d48. instance and a dict-like object which contains your
contextual information.  When you call one of the logging methods on an
instance of *note LoggerAdapter: 14fd, it delegates the call to the
underlying instance of *note Logger: d48. passed to its constructor, and
arranges to pass the contextual information in the delegated call.
Here’s a snippet from the code of *note LoggerAdapter: 14fd.:

     def debug(self, msg, /, *args, **kwargs):
         """
         Delegate a debug call to the underlying logger, after adding
         contextual information from this adapter instance.
         """
         msg, kwargs = self.process(msg, kwargs)
         self.logger.debug(msg, *args, **kwargs)

The *note process(): 3179. method of *note LoggerAdapter: 14fd. is where
the contextual information is added to the logging output.  It’s passed
the message and keyword arguments of the logging call, and it passes
back (potentially) modified versions of these to use in the call to the
underlying logger.  The default implementation of this method leaves the
message alone, but inserts an “extra” key in the keyword argument whose
value is the dict-like object passed to the constructor.  Of course, if
you had passed an “extra” keyword argument in the call to the adapter,
it will be silently overwritten.

The advantage of using “extra” is that the values in the dict-like
object are merged into the *note LogRecord: 11e8. instance’s __dict__,
allowing you to use customized strings with your *note Formatter: 169e.
instances which know about the keys of the dict-like object.  If you
need a different method, e.g.  if you want to prepend or append the
contextual information to the message string, you just need to subclass
*note LoggerAdapter: 14fd. and override *note process(): 3179. to do
what you need.  Here is a simple example:

     class CustomAdapter(logging.LoggerAdapter):
         """
         This example adapter expects the passed in dict-like object to have a
         'connid' key, whose value in brackets is prepended to the log message.
         """
         def process(self, msg, kwargs):
             return '[%s] %s' % (self.extra['connid'], msg), kwargs

which you can use like this:

     logger = logging.getLogger(__name__)
     adapter = CustomAdapter(logger, {'connid': some_conn_id})

Then any events that you log to the adapter will have the value of
‘some_conn_id’ prepended to the log messages.

* Menu:

* Using objects other than dicts to pass contextual information::


File: python.info,  Node: Using objects other than dicts to pass contextual information,  Up: Using LoggerAdapters to impart contextual information

9.9.9.2 Using objects other than dicts to pass contextual information
.....................................................................

You don’t need to pass an actual dict to a *note LoggerAdapter: 14fd. -
you could pass an instance of a class which implements ‘__getitem__’ and
‘__iter__’ so that it looks like a dict to logging.  This would be
useful if you want to generate values dynamically (whereas the values in
a dict would be constant).


File: python.info,  Node: Using Filters to impart contextual information,  Prev: Using LoggerAdapters to impart contextual information,  Up: Adding contextual information to your logging output

9.9.9.3 Using Filters to impart contextual information
......................................................

You can also add contextual information to log output using a
user-defined *note Filter: 1403.  ‘Filter’ instances are allowed to
modify the ‘LogRecords’ passed to them, including adding additional
attributes which can then be output using a suitable format string, or
if needed a custom *note Formatter: 169e.

For example in a web application, the request being processed (or at
least, the interesting parts of it) can be stored in a threadlocal
(*note threading.local: 1847.) variable, and then accessed from a
‘Filter’ to add, say, information from the request - say, the remote IP
address and remote user’s username - to the ‘LogRecord’, using the
attribute names “ip” and “user” as in the ‘LoggerAdapter’ example above.
In that case, the same format string can be used to get similar output
to that shown above.  Here’s an example script:

     import logging
     from random import choice

     class ContextFilter(logging.Filter):
         """
         This is a filter which injects contextual information into the log.

         Rather than use actual contextual information, we just use random
         data in this demo.
         """

         USERS = ['jim', 'fred', 'sheila']
         IPS = ['123.231.231.123', '127.0.0.1', '192.168.0.1']

         def filter(self, record):

             record.ip = choice(ContextFilter.IPS)
             record.user = choice(ContextFilter.USERS)
             return True

     if __name__ == '__main__':
         levels = (logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR, logging.CRITICAL)
         logging.basicConfig(level=logging.DEBUG,
                             format='%(asctime)-15s %(name)-5s %(levelname)-8s IP: %(ip)-15s User: %(user)-8s %(message)s')
         a1 = logging.getLogger('a.b.c')
         a2 = logging.getLogger('d.e.f')

         f = ContextFilter()
         a1.addFilter(f)
         a2.addFilter(f)
         a1.debug('A debug message')
         a1.info('An info message with %s', 'some parameters')
         for x in range(10):
             lvl = choice(levels)
             lvlname = logging.getLevelName(lvl)
             a2.log(lvl, 'A message at %s level with %d %s', lvlname, 2, 'parameters')

which, when run, produces something like:

     2010-09-06 22:38:15,292 a.b.c DEBUG    IP: 123.231.231.123 User: fred     A debug message
     2010-09-06 22:38:15,300 a.b.c INFO     IP: 192.168.0.1     User: sheila   An info message with some parameters
     2010-09-06 22:38:15,300 d.e.f CRITICAL IP: 127.0.0.1       User: sheila   A message at CRITICAL level with 2 parameters
     2010-09-06 22:38:15,300 d.e.f ERROR    IP: 127.0.0.1       User: jim      A message at ERROR level with 2 parameters
     2010-09-06 22:38:15,300 d.e.f DEBUG    IP: 127.0.0.1       User: sheila   A message at DEBUG level with 2 parameters
     2010-09-06 22:38:15,300 d.e.f ERROR    IP: 123.231.231.123 User: fred     A message at ERROR level with 2 parameters
     2010-09-06 22:38:15,300 d.e.f CRITICAL IP: 192.168.0.1     User: jim      A message at CRITICAL level with 2 parameters
     2010-09-06 22:38:15,300 d.e.f CRITICAL IP: 127.0.0.1       User: sheila   A message at CRITICAL level with 2 parameters
     2010-09-06 22:38:15,300 d.e.f DEBUG    IP: 192.168.0.1     User: jim      A message at DEBUG level with 2 parameters
     2010-09-06 22:38:15,301 d.e.f ERROR    IP: 127.0.0.1       User: sheila   A message at ERROR level with 2 parameters
     2010-09-06 22:38:15,301 d.e.f DEBUG    IP: 123.231.231.123 User: fred     A message at DEBUG level with 2 parameters
     2010-09-06 22:38:15,301 d.e.f INFO     IP: 123.231.231.123 User: fred     A message at INFO level with 2 parameters


File: python.info,  Node: Use of contextvars,  Next: Imparting contextual information in handlers,  Prev: Adding contextual information to your logging output,  Up: Logging Cookbook

9.9.10 Use of ‘contextvars’
---------------------------

Since Python 3.7, the *note contextvars: 28. module has provided
context-local storage which works for both *note threading: f3. and
*note asyncio: b. processing needs.  This type of storage may thus be
generally preferable to thread-locals.  The following example shows how,
in a multi-threaded environment, logs can populated with contextual
information such as, for example, request attributes handled by web
applications.

For the purposes of illustration, say that you have different web
applications, each independent of the other but running in the same
Python process and using a library common to them.  How can each of
these applications have their own log, where all logging messages from
the library (and other request processing code) are directed to the
appropriate application’s log file, while including in the log
additional contextual information such as client IP, HTTP request method
and client username?

Let’s assume that the library can be simulated by the following code:

     # webapplib.py
     import logging
     import time

     logger = logging.getLogger(__name__)

     def useful():
         # Just a representative event logged from the library
         logger.debug('Hello from webapplib!')
         # Just sleep for a bit so other threads get to run
         time.sleep(0.01)

We can simulate the multiple web applications by means of two simple
classes, ‘Request’ and ‘WebApp’.  These simulate how real threaded web
applications work - each request is handled by a thread:

     # main.py
     import argparse
     from contextvars import ContextVar
     import logging
     import os
     from random import choice
     import threading
     import webapplib

     logger = logging.getLogger(__name__)
     root = logging.getLogger()
     root.setLevel(logging.DEBUG)

     class Request:
         """
         A simple dummy request class which just holds dummy HTTP request method,
         client IP address and client username
         """
         def __init__(self, method, ip, user):
             self.method = method
             self.ip = ip
             self.user = user

     # A dummy set of requests which will be used in the simulation - we'll just pick
     # from this list randomly. Note that all GET requests are from 192.168.2.XXX
     # addresses, whereas POST requests are from 192.16.3.XXX addresses. Three users
     # are represented in the sample requests.

     REQUESTS = [
         Request('GET', '192.168.2.20', 'jim'),
         Request('POST', '192.168.3.20', 'fred'),
         Request('GET', '192.168.2.21', 'sheila'),
         Request('POST', '192.168.3.21', 'jim'),
         Request('GET', '192.168.2.22', 'fred'),
         Request('POST', '192.168.3.22', 'sheila'),
     ]

     # Note that the format string includes references to request context information
     # such as HTTP method, client IP and username

     formatter = logging.Formatter('%(threadName)-11s %(appName)s %(name)-9s %(user)-6s %(ip)s %(method)-4s %(message)s')

     # Create our context variables. These will be filled at the start of request
     # processing, and used in the logging that happens during that processing

     ctx_request = ContextVar('request')
     ctx_appname = ContextVar('appname')

     class InjectingFilter(logging.Filter):
         """
         A filter which injects context-specific information into logs and ensures
         that only information for a specific webapp is included in its log
         """
         def __init__(self, app):
             self.app = app

         def filter(self, record):
             request = ctx_request.get()
             record.method = request.method
             record.ip = request.ip
             record.user = request.user
             record.appName = appName = ctx_appname.get()
             return appName == self.app.name

     class WebApp:
         """
         A dummy web application class which has its own handler and filter for a
         webapp-specific log.
         """
         def __init__(self, name):
             self.name = name
             handler = logging.FileHandler(name + '.log', 'w')
             f = InjectingFilter(self)
             handler.setFormatter(formatter)
             handler.addFilter(f)
             root.addHandler(handler)
             self.num_requests = 0

         def process_request(self, request):
             """
             This is the dummy method for processing a request. It's called on a
             different thread for every request. We store the context information into
             the context vars before doing anything else.
             """
             ctx_request.set(request)
             ctx_appname.set(self.name)
             self.num_requests += 1
             logger.debug('Request processing started')
             webapplib.useful()
             logger.debug('Request processing finished')

     def main():
         fn = os.path.splitext(os.path.basename(__file__))[0]
         adhf = argparse.ArgumentDefaultsHelpFormatter
         ap = argparse.ArgumentParser(formatter_class=adhf, prog=fn,
                                      description='Simulate a couple of web '
                                                  'applications handling some '
                                                  'requests, showing how request '
                                                  'context can be used to '
                                                  'populate logs')
         aa = ap.add_argument
         aa('--count', '-c', type=int, default=100, help='How many requests to simulate')
         options = ap.parse_args()

         # Create the dummy webapps and put them in a list which we can use to select
         # from randomly
         app1 = WebApp('app1')
         app2 = WebApp('app2')
         apps = [app1, app2]
         threads = []
         # Add a common handler which will capture all events
         handler = logging.FileHandler('app.log', 'w')
         handler.setFormatter(formatter)
         root.addHandler(handler)

         # Generate calls to process requests
         for i in range(options.count):
             try:
                 # Pick an app at random and a request for it to process
                 app = choice(apps)
                 request = choice(REQUESTS)
                 # Process the request in its own thread
                 t = threading.Thread(target=app.process_request, args=(request,))
                 threads.append(t)
                 t.start()
             except KeyboardInterrupt:
                 break

         # Wait for the threads to terminate
         for t in threads:
             t.join()

         for app in apps:
             print('%s processed %s requests' % (app.name, app.num_requests))

     if __name__ == '__main__':
         main()

If you run the above, you should find that roughly half the requests go
into ‘app1.log’ and the rest into ‘app2.log’, and the all the requests
are logged to ‘app.log’.  Each webapp-specific log will contain only log
entries for only that webapp, and the request information will be
displayed consistently in the log (i.e.  the information in each dummy
request will always appear together in a log line).  This is illustrated
by the following shell output:

     ~/logging-contextual-webapp$ python main.py
     app1 processed 51 requests
     app2 processed 49 requests
     ~/logging-contextual-webapp$ wc -l *.log
       153 app1.log
       147 app2.log
       300 app.log
       600 total
     ~/logging-contextual-webapp$ head -3 app1.log
     Thread-3 (process_request) app1 __main__  jim    192.168.3.21 POST Request processing started
     Thread-3 (process_request) app1 webapplib jim    192.168.3.21 POST Hello from webapplib!
     Thread-5 (process_request) app1 __main__  jim    192.168.3.21 POST Request processing started
     ~/logging-contextual-webapp$ head -3 app2.log
     Thread-1 (process_request) app2 __main__  sheila 192.168.2.21 GET  Request processing started
     Thread-1 (process_request) app2 webapplib sheila 192.168.2.21 GET  Hello from webapplib!
     Thread-2 (process_request) app2 __main__  jim    192.168.2.20 GET  Request processing started
     ~/logging-contextual-webapp$ head app.log
     Thread-1 (process_request) app2 __main__  sheila 192.168.2.21 GET  Request processing started
     Thread-1 (process_request) app2 webapplib sheila 192.168.2.21 GET  Hello from webapplib!
     Thread-2 (process_request) app2 __main__  jim    192.168.2.20 GET  Request processing started
     Thread-3 (process_request) app1 __main__  jim    192.168.3.21 POST Request processing started
     Thread-2 (process_request) app2 webapplib jim    192.168.2.20 GET  Hello from webapplib!
     Thread-3 (process_request) app1 webapplib jim    192.168.3.21 POST Hello from webapplib!
     Thread-4 (process_request) app2 __main__  fred   192.168.2.22 GET  Request processing started
     Thread-5 (process_request) app1 __main__  jim    192.168.3.21 POST Request processing started
     Thread-4 (process_request) app2 webapplib fred   192.168.2.22 GET  Hello from webapplib!
     Thread-6 (process_request) app1 __main__  jim    192.168.3.21 POST Request processing started
     ~/logging-contextual-webapp$ grep app1 app1.log | wc -l
     153
     ~/logging-contextual-webapp$ grep app2 app2.log | wc -l
     147
     ~/logging-contextual-webapp$ grep app1 app.log | wc -l
     153
     ~/logging-contextual-webapp$ grep app2 app.log | wc -l
     147


File: python.info,  Node: Imparting contextual information in handlers,  Next: Logging to a single file from multiple processes,  Prev: Use of contextvars,  Up: Logging Cookbook

9.9.11 Imparting contextual information in handlers
---------------------------------------------------

Each *note Handler: 169d. has its own chain of filters.  If you want to
add contextual information to a *note LogRecord: 11e8. without leaking
it to other handlers, you can use a filter that returns a new *note
LogRecord: 11e8. instead of modifying it in-place, as shown in the
following script:

     import copy
     import logging

     def filter(record: logging.LogRecord):
         record = copy.copy(record)
         record.user = 'jim'
         return record

     if __name__ == '__main__':
         logger = logging.getLogger()
         logger.setLevel(logging.INFO)
         handler = logging.StreamHandler()
         formatter = logging.Formatter('%(message)s from %(user)-8s')
         handler.setFormatter(formatter)
         handler.addFilter(filter)
         logger.addHandler(handler)

         logger.info('A log message')


File: python.info,  Node: Logging to a single file from multiple processes,  Next: Using file rotation,  Prev: Imparting contextual information in handlers,  Up: Logging Cookbook

9.9.12 Logging to a single file from multiple processes
-------------------------------------------------------

Although logging is thread-safe, and logging to a single file from
multiple threads in a single process 'is' supported, logging to a single
file from 'multiple processes' is 'not' supported, because there is no
standard way to serialize access to a single file across multiple
processes in Python.  If you need to log to a single file from multiple
processes, one way of doing this is to have all the processes log to a
*note SocketHandler: 1164, and have a separate process which implements
a socket server which reads from the socket and logs to file.  (If you
prefer, you can dedicate one thread in one of the existing processes to
perform this function.)  *note This section: 5746. documents this
approach in more detail and includes a working socket receiver which can
be used as a starting point for you to adapt in your own applications.

You could also write your own handler which uses the *note Lock: 183b.
class from the *note multiprocessing: 98. module to serialize access to
the file from your processes.  The stdlib *note FileHandler: 1c3b. and
subclasses do not make use of *note multiprocessing: 98.

Alternatively, you can use a ‘Queue’ and a *note QueueHandler: 1b49. to
send all logging events to one of the processes in your multi-process
application.  The following example script demonstrates how you can do
this; in the example a separate listener process listens for events sent
by other processes and logs them according to its own logging
configuration.  Although the example only demonstrates one way of doing
it (for example, you may want to use a listener thread rather than a
separate listener process – the implementation would be analogous) it
does allow for completely different logging configurations for the
listener and the other processes in your application, and can be used as
the basis for code meeting your own specific requirements:

     # You'll need these imports in your own code
     import logging
     import logging.handlers
     import multiprocessing

     # Next two import lines for this demo only
     from random import choice, random
     import time

     #
     # Because you'll want to define the logging configurations for listener and workers, the
     # listener and worker process functions take a configurer parameter which is a callable
     # for configuring logging for that process. These functions are also passed the queue,
     # which they use for communication.
     #
     # In practice, you can configure the listener however you want, but note that in this
     # simple example, the listener does not apply level or filter logic to received records.
     # In practice, you would probably want to do this logic in the worker processes, to avoid
     # sending events which would be filtered out between processes.
     #
     # The size of the rotated files is made small so you can see the results easily.
     def listener_configurer():
         root = logging.getLogger()
         h = logging.handlers.RotatingFileHandler('mptest.log', 'a', 300, 10)
         f = logging.Formatter('%(asctime)s %(processName)-10s %(name)s %(levelname)-8s %(message)s')
         h.setFormatter(f)
         root.addHandler(h)

     # This is the listener process top-level loop: wait for logging events
     # (LogRecords)on the queue and handle them, quit when you get a None for a
     # LogRecord.
     def listener_process(queue, configurer):
         configurer()
         while True:
             try:
                 record = queue.get()
                 if record is None:  # We send this as a sentinel to tell the listener to quit.
                     break
                 logger = logging.getLogger(record.name)
                 logger.handle(record)  # No level or filter logic applied - just do it!
             except Exception:
                 import sys, traceback
                 print('Whoops! Problem:', file=sys.stderr)
                 traceback.print_exc(file=sys.stderr)

     # Arrays used for random selections in this demo

     LEVELS = [logging.DEBUG, logging.INFO, logging.WARNING,
               logging.ERROR, logging.CRITICAL]

     LOGGERS = ['a.b.c', 'd.e.f']

     MESSAGES = [
         'Random message #1',
         'Random message #2',
         'Random message #3',
     ]

     # The worker configuration is done at the start of the worker process run.
     # Note that on Windows you can't rely on fork semantics, so each process
     # will run the logging configuration code when it starts.
     def worker_configurer(queue):
         h = logging.handlers.QueueHandler(queue)  # Just the one handler needed
         root = logging.getLogger()
         root.addHandler(h)
         # send all messages, for demo; no other level or filter logic applied.
         root.setLevel(logging.DEBUG)

     # This is the worker process top-level loop, which just logs ten events with
     # random intervening delays before terminating.
     # The print messages are just so you know it's doing something!
     def worker_process(queue, configurer):
         configurer(queue)
         name = multiprocessing.current_process().name
         print('Worker started: %s' % name)
         for i in range(10):
             time.sleep(random())
             logger = logging.getLogger(choice(LOGGERS))
             level = choice(LEVELS)
             message = choice(MESSAGES)
             logger.log(level, message)
         print('Worker finished: %s' % name)

     # Here's where the demo gets orchestrated. Create the queue, create and start
     # the listener, create ten workers and start them, wait for them to finish,
     # then send a None to the queue to tell the listener to finish.
     def main():
         queue = multiprocessing.Queue(-1)
         listener = multiprocessing.Process(target=listener_process,
                                            args=(queue, listener_configurer))
         listener.start()
         workers = []
         for i in range(10):
             worker = multiprocessing.Process(target=worker_process,
                                              args=(queue, worker_configurer))
             workers.append(worker)
             worker.start()
         for w in workers:
             w.join()
         queue.put_nowait(None)
         listener.join()

     if __name__ == '__main__':
         main()

A variant of the above script keeps the logging in the main process, in
a separate thread:

     import logging
     import logging.config
     import logging.handlers
     from multiprocessing import Process, Queue
     import random
     import threading
     import time

     def logger_thread(q):
         while True:
             record = q.get()
             if record is None:
                 break
             logger = logging.getLogger(record.name)
             logger.handle(record)


     def worker_process(q):
         qh = logging.handlers.QueueHandler(q)
         root = logging.getLogger()
         root.setLevel(logging.DEBUG)
         root.addHandler(qh)
         levels = [logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR,
                   logging.CRITICAL]
         loggers = ['foo', 'foo.bar', 'foo.bar.baz',
                    'spam', 'spam.ham', 'spam.ham.eggs']
         for i in range(100):
             lvl = random.choice(levels)
             logger = logging.getLogger(random.choice(loggers))
             logger.log(lvl, 'Message no. %d', i)

     if __name__ == '__main__':
         q = Queue()
         d = {
             'version': 1,
             'formatters': {
                 'detailed': {
                     'class': 'logging.Formatter',
                     'format': '%(asctime)s %(name)-15s %(levelname)-8s %(processName)-10s %(message)s'
                 }
             },
             'handlers': {
                 'console': {
                     'class': 'logging.StreamHandler',
                     'level': 'INFO',
                 },
                 'file': {
                     'class': 'logging.FileHandler',
                     'filename': 'mplog.log',
                     'mode': 'w',
                     'formatter': 'detailed',
                 },
                 'foofile': {
                     'class': 'logging.FileHandler',
                     'filename': 'mplog-foo.log',
                     'mode': 'w',
                     'formatter': 'detailed',
                 },
                 'errors': {
                     'class': 'logging.FileHandler',
                     'filename': 'mplog-errors.log',
                     'mode': 'w',
                     'level': 'ERROR',
                     'formatter': 'detailed',
                 },
             },
             'loggers': {
                 'foo': {
                     'handlers': ['foofile']
                 }
             },
             'root': {
                 'level': 'DEBUG',
                 'handlers': ['console', 'file', 'errors']
             },
         }
         workers = []
         for i in range(5):
             wp = Process(target=worker_process, name='worker %d' % (i + 1), args=(q,))
             workers.append(wp)
             wp.start()
         logging.config.dictConfig(d)
         lp = threading.Thread(target=logger_thread, args=(q,))
         lp.start()
         # At this point, the main process could do some useful work of its own
         # Once it's done that, it can wait for the workers to terminate...
         for wp in workers:
             wp.join()
         # And now tell the logging thread to finish up, too
         q.put(None)
         lp.join()

This variant shows how you can e.g.  apply configuration for particular
loggers - e.g.  the ‘foo’ logger has a special handler which stores all
events in the ‘foo’ subsystem in a file ‘mplog-foo.log’.  This will be
used by the logging machinery in the main process (even though the
logging events are generated in the worker processes) to direct the
messages to the appropriate destinations.

* Menu:

* Using concurrent.futures.ProcessPoolExecutor: Using concurrent futures ProcessPoolExecutor.
* Deploying Web applications using Gunicorn and uWSGI::


File: python.info,  Node: Using concurrent futures ProcessPoolExecutor,  Next: Deploying Web applications using Gunicorn and uWSGI,  Up: Logging to a single file from multiple processes

9.9.12.1 Using concurrent.futures.ProcessPoolExecutor
.....................................................

If you want to use *note concurrent.futures.ProcessPoolExecutor: 1d6. to
start your worker processes, you need to create the queue slightly
differently.  Instead of

     queue = multiprocessing.Queue(-1)

you should use

     queue = multiprocessing.Manager().Queue(-1)  # also works with the examples above

and you can then replace the worker creation from this:

     workers = []
     for i in range(10):
         worker = multiprocessing.Process(target=worker_process,
                                          args=(queue, worker_configurer))
         workers.append(worker)
         worker.start()
     for w in workers:
         w.join()

to this (remembering to first import *note concurrent.futures: 24.):

     with concurrent.futures.ProcessPoolExecutor(max_workers=10) as executor:
         for i in range(10):
             executor.submit(worker_process, queue, worker_configurer)


File: python.info,  Node: Deploying Web applications using Gunicorn and uWSGI,  Prev: Using concurrent futures ProcessPoolExecutor,  Up: Logging to a single file from multiple processes

9.9.12.2 Deploying Web applications using Gunicorn and uWSGI
............................................................

When deploying Web applications using Gunicorn(1) or uWSGI(2) (or
similar), multiple worker processes are created to handle client
requests.  In such environments, avoid creating file-based handlers
directly in your web application.  Instead, use a *note SocketHandler:
1164. to log from the web application to a listener in a separate
process.  This can be set up using a process management tool such as
Supervisor - see *note Running a logging socket listener in production:
5748. for more details.

   ---------- Footnotes ----------

   (1) https://gunicorn.org/

   (2) https://uwsgi-docs.readthedocs.io/en/latest/


File: python.info,  Node: Using file rotation,  Next: Use of alternative formatting styles,  Prev: Logging to a single file from multiple processes,  Up: Logging Cookbook

9.9.13 Using file rotation
--------------------------

Sometimes you want to let a log file grow to a certain size, then open a
new file and log to that.  You may want to keep a certain number of
these files, and when that many files have been created, rotate the
files so that the number of files and the size of the files both remain
bounded.  For this usage pattern, the logging package provides a *note
RotatingFileHandler: 1929.:

     import glob
     import logging
     import logging.handlers

     LOG_FILENAME = 'logging_rotatingfile_example.out'

     # Set up a specific logger with our desired output level
     my_logger = logging.getLogger('MyLogger')
     my_logger.setLevel(logging.DEBUG)

     # Add the log message handler to the logger
     handler = logging.handlers.RotatingFileHandler(
                   LOG_FILENAME, maxBytes=20, backupCount=5)

     my_logger.addHandler(handler)

     # Log some messages
     for i in range(20):
         my_logger.debug('i = %d' % i)

     # See what files are created
     logfiles = glob.glob('%s*' % LOG_FILENAME)

     for filename in logfiles:
         print(filename)

The result should be 6 separate files, each with part of the log history
for the application:

     logging_rotatingfile_example.out
     logging_rotatingfile_example.out.1
     logging_rotatingfile_example.out.2
     logging_rotatingfile_example.out.3
     logging_rotatingfile_example.out.4
     logging_rotatingfile_example.out.5

The most current file is always ‘logging_rotatingfile_example.out’, and
each time it reaches the size limit it is renamed with the suffix ‘.1’.
Each of the existing backup files is renamed to increment the suffix
(‘.1’ becomes ‘.2’, etc.)  and the ‘.6’ file is erased.

Obviously this example sets the log length much too small as an extreme
example.  You would want to set 'maxBytes' to an appropriate value.


File: python.info,  Node: Use of alternative formatting styles,  Next: Customizing LogRecord,  Prev: Using file rotation,  Up: Logging Cookbook

9.9.14 Use of alternative formatting styles
-------------------------------------------

When logging was added to the Python standard library, the only way of
formatting messages with variable content was to use the %-formatting
method.  Since then, Python has gained two new formatting approaches:
*note string.Template: 898. (added in Python 2.4) and *note
str.format(): 834. (added in Python 2.6).

Logging (as of 3.2) provides improved support for these two additional
formatting styles.  The *note Formatter: 169e. class been enhanced to
take an additional, optional keyword parameter named ‘style’.  This
defaults to ‘'%'’, but other possible values are ‘'{'’ and ‘'$'’, which
correspond to the other two formatting styles.  Backwards compatibility
is maintained by default (as you would expect), but by explicitly
specifying a style parameter, you get the ability to specify format
strings which work with *note str.format(): 834. or *note
string.Template: 898.  Here’s an example console session to show the
possibilities:

     >>> import logging
     >>> root = logging.getLogger()
     >>> root.setLevel(logging.DEBUG)
     >>> handler = logging.StreamHandler()
     >>> bf = logging.Formatter('{asctime} {name} {levelname:8s} {message}',
     ...                        style='{')
     >>> handler.setFormatter(bf)
     >>> root.addHandler(handler)
     >>> logger = logging.getLogger('foo.bar')
     >>> logger.debug('This is a DEBUG message')
     2010-10-28 15:11:55,341 foo.bar DEBUG    This is a DEBUG message
     >>> logger.critical('This is a CRITICAL message')
     2010-10-28 15:12:11,526 foo.bar CRITICAL This is a CRITICAL message
     >>> df = logging.Formatter('$asctime $name ${levelname} $message',
     ...                        style='$')
     >>> handler.setFormatter(df)
     >>> logger.debug('This is a DEBUG message')
     2010-10-28 15:13:06,924 foo.bar DEBUG This is a DEBUG message
     >>> logger.critical('This is a CRITICAL message')
     2010-10-28 15:13:11,494 foo.bar CRITICAL This is a CRITICAL message
     >>>

Note that the formatting of logging messages for final output to logs is
completely independent of how an individual logging message is
constructed.  That can still use %-formatting, as shown here:

     >>> logger.error('This is an%s %s %s', 'other,', 'ERROR,', 'message')
     2010-10-28 15:19:29,833 foo.bar ERROR This is another, ERROR, message
     >>>

Logging calls (‘logger.debug()’, ‘logger.info()’ etc.)  only take
positional parameters for the actual logging message itself, with
keyword parameters used only for determining options for how to handle
the actual logging call (e.g.  the ‘exc_info’ keyword parameter to
indicate that traceback information should be logged, or the ‘extra’
keyword parameter to indicate additional contextual information to be
added to the log).  So you cannot directly make logging calls using
*note str.format(): 834. or *note string.Template: 898. syntax, because
internally the logging package uses %-formatting to merge the format
string and the variable arguments.  There would be no changing this
while preserving backward compatibility, since all logging calls which
are out there in existing code will be using %-format strings.

There is, however, a way that you can use {}- and $- formatting to
construct your individual log messages.  Recall that for a message you
can use an arbitrary object as a message format string, and that the
logging package will call ‘str()’ on that object to get the actual
format string.  Consider the following two classes:

     class BraceMessage:
         def __init__(self, fmt, /, *args, **kwargs):
             self.fmt = fmt
             self.args = args
             self.kwargs = kwargs

         def __str__(self):
             return self.fmt.format(*self.args, **self.kwargs)

     class DollarMessage:
         def __init__(self, fmt, /, **kwargs):
             self.fmt = fmt
             self.kwargs = kwargs

         def __str__(self):
             from string import Template
             return Template(self.fmt).substitute(**self.kwargs)

Either of these can be used in place of a format string, to allow {}- or
$-formatting to be used to build the actual «message» part which appears
in the formatted log output in place of «%(message)s» or «{message}» or
«$message».  It’s a little unwieldy to use the class names whenever you
want to log something, but it’s quite palatable if you use an alias such
as __ (double underscore — not to be confused with _, the single
underscore used as a synonym/alias for *note gettext.gettext(): 1670. or
its brethren).

The above classes are not included in Python, though they’re easy enough
to copy and paste into your own code.  They can be used as follows
(assuming that they’re declared in a module called ‘wherever’):

     >>> from wherever import BraceMessage as __
     >>> print(__('Message with {0} {name}', 2, name='placeholders'))
     Message with 2 placeholders
     >>> class Point: pass
     ...
     >>> p = Point()
     >>> p.x = 0.5
     >>> p.y = 0.5
     >>> print(__('Message with coordinates: ({point.x:.2f}, {point.y:.2f})',
     ...       point=p))
     Message with coordinates: (0.50, 0.50)
     >>> from wherever import DollarMessage as __
     >>> print(__('Message with $num $what', num=2, what='placeholders'))
     Message with 2 placeholders
     >>>

While the above examples use ‘print()’ to show how the formatting works,
you would of course use ‘logger.debug()’ or similar to actually log
using this approach.

One thing to note is that you pay no significant performance penalty
with this approach: the actual formatting happens not when you make the
logging call, but when (and if) the logged message is actually about to
be output to a log by a handler.  So the only slightly unusual thing
which might trip you up is that the parentheses go around the format
string and the arguments, not just the format string.  That’s because
the __ notation is just syntax sugar for a constructor call to one of
the ‘XXXMessage’ classes.

If you prefer, you can use a *note LoggerAdapter: 14fd. to achieve a
similar effect to the above, as in the following example:

     import logging

     class Message:
         def __init__(self, fmt, args):
             self.fmt = fmt
             self.args = args

         def __str__(self):
             return self.fmt.format(*self.args)

     class StyleAdapter(logging.LoggerAdapter):
         def log(self, level, msg, /, *args, stacklevel=1, **kwargs):
             if self.isEnabledFor(level):
                 msg, kwargs = self.process(msg, kwargs)
                 self.logger.log(level, Message(msg, args), **kwargs,
                                 stacklevel=stacklevel+1)

     logger = StyleAdapter(logging.getLogger(__name__))

     def main():
         logger.debug('Hello, {}', 'world!')

     if __name__ == '__main__':
         logging.basicConfig(level=logging.DEBUG)
         main()

The above script should log the message ‘Hello, world!’ when run with
Python 3.8 or later.


File: python.info,  Node: Customizing LogRecord,  Next: Subclassing QueueHandler and QueueListener- a ZeroMQ example,  Prev: Use of alternative formatting styles,  Up: Logging Cookbook

9.9.15 Customizing ‘LogRecord’
------------------------------

Every logging event is represented by a *note LogRecord: 11e8. instance.
When an event is logged and not filtered out by a logger’s level, a
*note LogRecord: 11e8. is created, populated with information about the
event and then passed to the handlers for that logger (and its
ancestors, up to and including the logger where further propagation up
the hierarchy is disabled).  Before Python 3.2, there were only two
places where this creation was done:

   * *note Logger.makeRecord(): 314a, which is called in the normal
     process of logging an event.  This invoked *note LogRecord: 11e8.
     directly to create an instance.

   * *note makeLogRecord(): 3170, which is called with a dictionary
     containing attributes to be added to the LogRecord.  This is
     typically invoked when a suitable dictionary has been received over
     the network (e.g.  in pickle form via a *note SocketHandler: 1164,
     or in JSON form via an *note HTTPHandler: 102e.).

This has usually meant that if you need to do anything special with a
*note LogRecord: 11e8, you’ve had to do one of the following.

   * Create your own *note Logger: d48. subclass, which overrides *note
     Logger.makeRecord(): 314a, and set it using *note setLoggerClass():
     317f. before any loggers that you care about are instantiated.

   * Add a *note Filter: 1403. to a logger or handler, which does the
     necessary special manipulation you need when its *note filter():
     316b. method is called.

The first approach would be a little unwieldy in the scenario where
(say) several different libraries wanted to do different things.  Each
would attempt to set its own *note Logger: d48. subclass, and the one
which did this last would win.

The second approach works reasonably well for many cases, but does not
allow you to e.g.  use a specialized subclass of *note LogRecord: 11e8.
Library developers can set a suitable filter on their loggers, but they
would have to remember to do this every time they introduced a new
logger (which they would do simply by adding new packages or modules and
doing

     logger = logging.getLogger(__name__)

at module level).  It’s probably one too many things to think about.
Developers could also add the filter to a *note NullHandler: 148c.
attached to their top-level logger, but this would not be invoked if an
application developer attached a handler to a lower-level library logger
— so output from that handler would not reflect the intentions of the
library developer.

In Python 3.2 and later, *note LogRecord: 11e8. creation is done through
a factory, which you can specify.  The factory is just a callable you
can set with *note setLogRecordFactory(): 3174, and interrogate with
*note getLogRecordFactory(): 3173.  The factory is invoked with the same
signature as the *note LogRecord: 11e8. constructor, as *note LogRecord:
11e8. is the default setting for the factory.

This approach allows a custom factory to control all aspects of
LogRecord creation.  For example, you could return a subclass, or just
add some additional attributes to the record once created, using a
pattern similar to this:

     old_factory = logging.getLogRecordFactory()

     def record_factory(*args, **kwargs):
         record = old_factory(*args, **kwargs)
         record.custom_attribute = 0xdecafbad
         return record

     logging.setLogRecordFactory(record_factory)

This pattern allows different libraries to chain factories together, and
as long as they don’t overwrite each other’s attributes or
unintentionally overwrite the attributes provided as standard, there
should be no surprises.  However, it should be borne in mind that each
link in the chain adds run-time overhead to all logging operations, and
the technique should only be used when the use of a *note Filter: 1403.
does not provide the desired result.


File: python.info,  Node: Subclassing QueueHandler and QueueListener- a ZeroMQ example,  Next: Subclassing QueueHandler and QueueListener- a pynng example,  Prev: Customizing LogRecord,  Up: Logging Cookbook

9.9.16 Subclassing QueueHandler and QueueListener- a ZeroMQ example
-------------------------------------------------------------------

* Menu:

* Subclass QueueHandler::
* Subclass QueueListener::


File: python.info,  Node: Subclass QueueHandler,  Next: Subclass QueueListener,  Up: Subclassing QueueHandler and QueueListener- a ZeroMQ example

9.9.16.1 Subclass ‘QueueHandler’
................................

You can use a *note QueueHandler: 1b49. subclass to send messages to
other kinds of queues, for example a ZeroMQ “publish” socket.  In the
example below,the socket is created separately and passed to the handler
(as its “queue”):

     import zmq   # using pyzmq, the Python binding for ZeroMQ
     import json  # for serializing records portably

     ctx = zmq.Context()
     sock = zmq.Socket(ctx, zmq.PUB)  # or zmq.PUSH, or other suitable value
     sock.bind('tcp://*:5556')        # or wherever

     class ZeroMQSocketHandler(QueueHandler):
         def enqueue(self, record):
             self.queue.send_json(record.__dict__)


     handler = ZeroMQSocketHandler(sock)

Of course there are other ways of organizing this, for example passing
in the data needed by the handler to create the socket:

     class ZeroMQSocketHandler(QueueHandler):
         def __init__(self, uri, socktype=zmq.PUB, ctx=None):
             self.ctx = ctx or zmq.Context()
             socket = zmq.Socket(self.ctx, socktype)
             socket.bind(uri)
             super().__init__(socket)

         def enqueue(self, record):
             self.queue.send_json(record.__dict__)

         def close(self):
             self.queue.close()


File: python.info,  Node: Subclass QueueListener,  Prev: Subclass QueueHandler,  Up: Subclassing QueueHandler and QueueListener- a ZeroMQ example

9.9.16.2 Subclass ‘QueueListener’
.................................

You can also subclass *note QueueListener: 242. to get messages from
other kinds of queues, for example a ZeroMQ “subscribe” socket.  Here’s
an example:

     class ZeroMQSocketListener(QueueListener):
         def __init__(self, uri, /, *handlers, **kwargs):
             self.ctx = kwargs.get('ctx') or zmq.Context()
             socket = zmq.Socket(self.ctx, zmq.SUB)
             socket.setsockopt_string(zmq.SUBSCRIBE, '')  # subscribe to everything
             socket.connect(uri)
             super().__init__(socket, *handlers, **kwargs)

         def dequeue(self):
             msg = self.queue.recv_json()
             return logging.makeLogRecord(msg)


File: python.info,  Node: Subclassing QueueHandler and QueueListener- a pynng example,  Next: An example dictionary-based configuration,  Prev: Subclassing QueueHandler and QueueListener- a ZeroMQ example,  Up: Logging Cookbook

9.9.17 Subclassing QueueHandler and QueueListener- a ‘pynng’ example
--------------------------------------------------------------------

In a similar way to the above section, we can implement a listener and
handler using pynng(1), which is a Python binding to NNG(2), billed as a
spiritual successor to ZeroMQ. The following snippets illustrate – you
can test them in an environment which has ‘pynng’ installed.  Just for
variety, we present the listener first.

* Menu:

* Subclass QueueListener: Subclass QueueListener<2>.
* Subclass QueueHandler: Subclass QueueHandler<2>.

   ---------- Footnotes ----------

   (1) https://pypi.org/project/pynng/

   (2) https://nng.nanomsg.org/


File: python.info,  Node: Subclass QueueListener<2>,  Next: Subclass QueueHandler<2>,  Up: Subclassing QueueHandler and QueueListener- a pynng example

9.9.17.1 Subclass ‘QueueListener’
.................................

     # listener.py
     import json
     import logging
     import logging.handlers

     import pynng

     DEFAULT_ADDR = "tcp://localhost:13232"

     interrupted = False

     class NNGSocketListener(logging.handlers.QueueListener):

         def __init__(self, uri, /, *handlers, **kwargs):
             # Have a timeout for interruptability, and open a
             # subscriber socket
             socket = pynng.Sub0(listen=uri, recv_timeout=500)
             # The b'' subscription matches all topics
             topics = kwargs.pop('topics', None) or b''
             socket.subscribe(topics)
             # We treat the socket as a queue
             super().__init__(socket, *handlers, **kwargs)

         def dequeue(self, block):
             data = None
             # Keep looping while not interrupted and no data received over the
             # socket
             while not interrupted:
                 try:
                     data = self.queue.recv(block=block)
                     break
                 except pynng.Timeout:
                     pass
                 except pynng.Closed:  # sometimes happens when you hit Ctrl-C
                     break
             if data is None:
                 return None
             # Get the logging event sent from a publisher
             event = json.loads(data.decode('utf-8'))
             return logging.makeLogRecord(event)

         def enqueue_sentinel(self):
             # Not used in this implementation, as the socket isn't really a
             # queue
             pass

     logging.getLogger('pynng').propagate = False
     listener = NNGSocketListener(DEFAULT_ADDR, logging.StreamHandler(), topics=b'')
     listener.start()
     print('Press Ctrl-C to stop.')
     try:
         while True:
             pass
     except KeyboardInterrupt:
         interrupted = True
     finally:
         listener.stop()


File: python.info,  Node: Subclass QueueHandler<2>,  Prev: Subclass QueueListener<2>,  Up: Subclassing QueueHandler and QueueListener- a pynng example

9.9.17.2 Subclass ‘QueueHandler’
................................

     # sender.py
     import json
     import logging
     import logging.handlers
     import time
     import random

     import pynng

     DEFAULT_ADDR = "tcp://localhost:13232"

     class NNGSocketHandler(logging.handlers.QueueHandler):

         def __init__(self, uri):
             socket = pynng.Pub0(dial=uri, send_timeout=500)
             super().__init__(socket)

         def enqueue(self, record):
             # Send the record as UTF-8 encoded JSON
             d = dict(record.__dict__)
             data = json.dumps(d)
             self.queue.send(data.encode('utf-8'))

         def close(self):
             self.queue.close()

     logging.getLogger('pynng').propagate = False
     handler = NNGSocketHandler(DEFAULT_ADDR)
     # Make sure the process ID is in the output
     logging.basicConfig(level=logging.DEBUG,
                         handlers=[logging.StreamHandler(), handler],
                         format='%(levelname)-8s %(name)10s %(process)6s %(message)s')
     levels = (logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR,
               logging.CRITICAL)
     logger_names = ('myapp', 'myapp.lib1', 'myapp.lib2')
     msgno = 1
     while True:
         # Just randomly select some loggers and levels and log away
         level = random.choice(levels)
         logger = logging.getLogger(random.choice(logger_names))
         logger.log(level, 'Message no. %5d' % msgno)
         msgno += 1
         delay = random.random() * 2 + 0.5
         time.sleep(delay)

You can run the above two snippets in separate command shells.  If we
run the listener in one shell and run the sender in two separate shells,
we should see something like the following.  In the first sender shell:

     $ python sender.py
     DEBUG         myapp    613 Message no.     1
     WARNING  myapp.lib2    613 Message no.     2
     CRITICAL myapp.lib2    613 Message no.     3
     WARNING  myapp.lib2    613 Message no.     4
     CRITICAL myapp.lib1    613 Message no.     5
     DEBUG         myapp    613 Message no.     6
     CRITICAL myapp.lib1    613 Message no.     7
     INFO     myapp.lib1    613 Message no.     8
     (and so on)

In the second sender shell:

     $ python sender.py
     INFO     myapp.lib2    657 Message no.     1
     CRITICAL myapp.lib2    657 Message no.     2
     CRITICAL      myapp    657 Message no.     3
     CRITICAL myapp.lib1    657 Message no.     4
     INFO     myapp.lib1    657 Message no.     5
     WARNING  myapp.lib2    657 Message no.     6
     CRITICAL      myapp    657 Message no.     7
     DEBUG    myapp.lib1    657 Message no.     8
     (and so on)

In the listener shell:

     $ python listener.py
     Press Ctrl-C to stop.
     DEBUG         myapp    613 Message no.     1
     WARNING  myapp.lib2    613 Message no.     2
     INFO     myapp.lib2    657 Message no.     1
     CRITICAL myapp.lib2    613 Message no.     3
     CRITICAL myapp.lib2    657 Message no.     2
     CRITICAL      myapp    657 Message no.     3
     WARNING  myapp.lib2    613 Message no.     4
     CRITICAL myapp.lib1    613 Message no.     5
     CRITICAL myapp.lib1    657 Message no.     4
     INFO     myapp.lib1    657 Message no.     5
     DEBUG         myapp    613 Message no.     6
     WARNING  myapp.lib2    657 Message no.     6
     CRITICAL      myapp    657 Message no.     7
     CRITICAL myapp.lib1    613 Message no.     7
     INFO     myapp.lib1    613 Message no.     8
     DEBUG    myapp.lib1    657 Message no.     8
     (and so on)

As you can see, the logging from the two sender processes is interleaved
in the listener’s output.


File: python.info,  Node: An example dictionary-based configuration,  Next: Using a rotator and namer to customize log rotation processing,  Prev: Subclassing QueueHandler and QueueListener- a pynng example,  Up: Logging Cookbook

9.9.18 An example dictionary-based configuration
------------------------------------------------

Below is an example of a logging configuration dictionary - it’s taken
from the documentation on the Django project(1).  This dictionary is
passed to *note dictConfig(): 13b8. to put the configuration into
effect:

     LOGGING = {
         'version': 1,
         'disable_existing_loggers': False,
         'formatters': {
             'verbose': {
                 'format': '{levelname} {asctime} {module} {process:d} {thread:d} {message}',
                 'style': '{',
             },
             'simple': {
                 'format': '{levelname} {message}',
                 'style': '{',
             },
         },
         'filters': {
             'special': {
                 '()': 'project.logging.SpecialFilter',
                 'foo': 'bar',
             },
         },
         'handlers': {
             'console': {
                 'level': 'INFO',
                 'class': 'logging.StreamHandler',
                 'formatter': 'simple',
             },
             'mail_admins': {
                 'level': 'ERROR',
                 'class': 'django.utils.log.AdminEmailHandler',
                 'filters': ['special']
             }
         },
         'loggers': {
             'django': {
                 'handlers': ['console'],
                 'propagate': True,
             },
             'django.request': {
                 'handlers': ['mail_admins'],
                 'level': 'ERROR',
                 'propagate': False,
             },
             'myproject.custom': {
                 'handlers': ['console', 'mail_admins'],
                 'level': 'INFO',
                 'filters': ['special']
             }
         }
     }

For more information about this configuration, you can see the relevant
section(2) of the Django documentation.

   ---------- Footnotes ----------

   (1) 
https://docs.djangoproject.com/en/stable/topics/logging/#configuring-logging

   (2) 
https://docs.djangoproject.com/en/stable/topics/logging/#configuring-logging


File: python.info,  Node: Using a rotator and namer to customize log rotation processing,  Next: A more elaborate multiprocessing example,  Prev: An example dictionary-based configuration,  Up: Logging Cookbook

9.9.19 Using a rotator and namer to customize log rotation processing
---------------------------------------------------------------------

An example of how you can define a namer and rotator is given in the
following runnable script, which shows gzip compression of the log file:

     import gzip
     import logging
     import logging.handlers
     import os
     import shutil

     def namer(name):
         return name + ".gz"

     def rotator(source, dest):
         with open(source, 'rb') as f_in:
             with gzip.open(dest, 'wb') as f_out:
                 shutil.copyfileobj(f_in, f_out)
         os.remove(source)


     rh = logging.handlers.RotatingFileHandler('rotated.log', maxBytes=128, backupCount=5)
     rh.rotator = rotator
     rh.namer = namer

     root = logging.getLogger()
     root.setLevel(logging.INFO)
     root.addHandler(rh)
     f = logging.Formatter('%(asctime)s %(message)s')
     rh.setFormatter(f)
     for i in range(1000):
         root.info(f'Message no. {i + 1}')

After running this, you will see six new files, five of which are
compressed:

     $ ls rotated.log*
     rotated.log       rotated.log.2.gz  rotated.log.4.gz
     rotated.log.1.gz  rotated.log.3.gz  rotated.log.5.gz
     $ zcat rotated.log.1.gz
     2023-01-20 02:28:17,767 Message no. 996
     2023-01-20 02:28:17,767 Message no. 997
     2023-01-20 02:28:17,767 Message no. 998


File: python.info,  Node: A more elaborate multiprocessing example,  Next: Inserting a BOM into messages sent to a SysLogHandler,  Prev: Using a rotator and namer to customize log rotation processing,  Up: Logging Cookbook

9.9.20 A more elaborate multiprocessing example
-----------------------------------------------

The following working example shows how logging can be used with
multiprocessing using configuration files.  The configurations are
fairly simple, but serve to illustrate how more complex ones could be
implemented in a real multiprocessing scenario.

In the example, the main process spawns a listener process and some
worker processes.  Each of the main process, the listener and the
workers have three separate configurations (the workers all share the
same configuration).  We can see logging in the main process, how the
workers log to a QueueHandler and how the listener implements a
QueueListener and a more complex logging configuration, and arranges to
dispatch events received via the queue to the handlers specified in the
configuration.  Note that these configurations are purely illustrative,
but you should be able to adapt this example to your own scenario.

Here’s the script - the docstrings and the comments hopefully explain
how it works:

     import logging
     import logging.config
     import logging.handlers
     from multiprocessing import Process, Queue, Event, current_process
     import os
     import random
     import time

     class MyHandler:
         """
         A simple handler for logging events. It runs in the listener process and
         dispatches events to loggers based on the name in the received record,
         which then get dispatched, by the logging system, to the handlers
         configured for those loggers.
         """

         def handle(self, record):
             if record.name == "root":
                 logger = logging.getLogger()
             else:
                 logger = logging.getLogger(record.name)

             if logger.isEnabledFor(record.levelno):
                 # The process name is transformed just to show that it's the listener
                 # doing the logging to files and console
                 record.processName = '%s (for %s)' % (current_process().name, record.processName)
                 logger.handle(record)

     def listener_process(q, stop_event, config):
         """
         This could be done in the main process, but is just done in a separate
         process for illustrative purposes.

         This initialises logging according to the specified configuration,
         starts the listener and waits for the main process to signal completion
         via the event. The listener is then stopped, and the process exits.
         """
         logging.config.dictConfig(config)
         listener = logging.handlers.QueueListener(q, MyHandler())
         listener.start()
         if os.name == 'posix':
             # On POSIX, the setup logger will have been configured in the
             # parent process, but should have been disabled following the
             # dictConfig call.
             # On Windows, since fork isn't used, the setup logger won't
             # exist in the child, so it would be created and the message
             # would appear - hence the "if posix" clause.
             logger = logging.getLogger('setup')
             logger.critical('Should not appear, because of disabled logger ...')
         stop_event.wait()
         listener.stop()

     def worker_process(config):
         """
         A number of these are spawned for the purpose of illustration. In
         practice, they could be a heterogeneous bunch of processes rather than
         ones which are identical to each other.

         This initialises logging according to the specified configuration,
         and logs a hundred messages with random levels to randomly selected
         loggers.

         A small sleep is added to allow other processes a chance to run. This
         is not strictly needed, but it mixes the output from the different
         processes a bit more than if it's left out.
         """
         logging.config.dictConfig(config)
         levels = [logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR,
                   logging.CRITICAL]
         loggers = ['foo', 'foo.bar', 'foo.bar.baz',
                    'spam', 'spam.ham', 'spam.ham.eggs']
         if os.name == 'posix':
             # On POSIX, the setup logger will have been configured in the
             # parent process, but should have been disabled following the
             # dictConfig call.
             # On Windows, since fork isn't used, the setup logger won't
             # exist in the child, so it would be created and the message
             # would appear - hence the "if posix" clause.
             logger = logging.getLogger('setup')
             logger.critical('Should not appear, because of disabled logger ...')
         for i in range(100):
             lvl = random.choice(levels)
             logger = logging.getLogger(random.choice(loggers))
             logger.log(lvl, 'Message no. %d', i)
             time.sleep(0.01)

     def main():
         q = Queue()
         # The main process gets a simple configuration which prints to the console.
         config_initial = {
             'version': 1,
             'handlers': {
                 'console': {
                     'class': 'logging.StreamHandler',
                     'level': 'INFO'
                 }
             },
             'root': {
                 'handlers': ['console'],
                 'level': 'DEBUG'
             }
         }
         # The worker process configuration is just a QueueHandler attached to the
         # root logger, which allows all messages to be sent to the queue.
         # We disable existing loggers to disable the "setup" logger used in the
         # parent process. This is needed on POSIX because the logger will
         # be there in the child following a fork().
         config_worker = {
             'version': 1,
             'disable_existing_loggers': True,
             'handlers': {
                 'queue': {
                     'class': 'logging.handlers.QueueHandler',
                     'queue': q
                 }
             },
             'root': {
                 'handlers': ['queue'],
                 'level': 'DEBUG'
             }
         }
         # The listener process configuration shows that the full flexibility of
         # logging configuration is available to dispatch events to handlers however
         # you want.
         # We disable existing loggers to disable the "setup" logger used in the
         # parent process. This is needed on POSIX because the logger will
         # be there in the child following a fork().
         config_listener = {
             'version': 1,
             'disable_existing_loggers': True,
             'formatters': {
                 'detailed': {
                     'class': 'logging.Formatter',
                     'format': '%(asctime)s %(name)-15s %(levelname)-8s %(processName)-10s %(message)s'
                 },
                 'simple': {
                     'class': 'logging.Formatter',
                     'format': '%(name)-15s %(levelname)-8s %(processName)-10s %(message)s'
                 }
             },
             'handlers': {
                 'console': {
                     'class': 'logging.StreamHandler',
                     'formatter': 'simple',
                     'level': 'INFO'
                 },
                 'file': {
                     'class': 'logging.FileHandler',
                     'filename': 'mplog.log',
                     'mode': 'w',
                     'formatter': 'detailed'
                 },
                 'foofile': {
                     'class': 'logging.FileHandler',
                     'filename': 'mplog-foo.log',
                     'mode': 'w',
                     'formatter': 'detailed'
                 },
                 'errors': {
                     'class': 'logging.FileHandler',
                     'filename': 'mplog-errors.log',
                     'mode': 'w',
                     'formatter': 'detailed',
                     'level': 'ERROR'
                 }
             },
             'loggers': {
                 'foo': {
                     'handlers': ['foofile']
                 }
             },
             'root': {
                 'handlers': ['console', 'file', 'errors'],
                 'level': 'DEBUG'
             }
         }
         # Log some initial events, just to show that logging in the parent works
         # normally.
         logging.config.dictConfig(config_initial)
         logger = logging.getLogger('setup')
         logger.info('About to create workers ...')
         workers = []
         for i in range(5):
             wp = Process(target=worker_process, name='worker %d' % (i + 1),
                          args=(config_worker,))
             workers.append(wp)
             wp.start()
             logger.info('Started worker: %s', wp.name)
         logger.info('About to create listener ...')
         stop_event = Event()
         lp = Process(target=listener_process, name='listener',
                      args=(q, stop_event, config_listener))
         lp.start()
         logger.info('Started listener')
         # We now hang around for the workers to finish their work.
         for wp in workers:
             wp.join()
         # Workers all done, listening can now stop.
         # Logging in the parent still works normally.
         logger.info('Telling listener to stop ...')
         stop_event.set()
         lp.join()
         logger.info('All done.')

     if __name__ == '__main__':
         main()


File: python.info,  Node: Inserting a BOM into messages sent to a SysLogHandler,  Next: Implementing structured logging,  Prev: A more elaborate multiprocessing example,  Up: Logging Cookbook

9.9.21 Inserting a BOM into messages sent to a SysLogHandler
------------------------------------------------------------

RFC 5424(1) requires that a Unicode message be sent to a syslog daemon
as a set of bytes which have the following structure: an optional
pure-ASCII component, followed by a UTF-8 Byte Order Mark (BOM),
followed by Unicode encoded using UTF-8.  (See the relevant section of
the specification(2).)

In Python 3.1, code was added to *note SysLogHandler: 86d. to insert a
BOM into the message, but unfortunately, it was implemented incorrectly,
with the BOM appearing at the beginning of the message and hence not
allowing any pure-ASCII component to appear before it.

As this behaviour is broken, the incorrect BOM insertion code is being
removed from Python 3.2.4 and later.  However, it is not being replaced,
and if you want to produce RFC 5424(3)-compliant messages which include
a BOM, an optional pure-ASCII sequence before it and arbitrary Unicode
after it, encoded using UTF-8, then you need to do the following:

  1. Attach a *note Formatter: 169e. instance to your *note
     SysLogHandler: 86d. instance, with a format string such as:

          'ASCII section\ufeffUnicode section'

     The Unicode code point U+FEFF, when encoded using UTF-8, will be
     encoded as a UTF-8 BOM – the byte-string ‘b'\xef\xbb\xbf'’.

  2. Replace the ASCII section with whatever placeholders you like, but
     make sure that the data that appears in there after substitution is
     always ASCII (that way, it will remain unchanged after UTF-8
     encoding).

  3. Replace the Unicode section with whatever placeholders you like; if
     the data which appears there after substitution contains characters
     outside the ASCII range, that’s fine – it will be encoded using
     UTF-8.

The formatted message 'will' be encoded using UTF-8 encoding by
‘SysLogHandler’.  If you follow the above rules, you should be able to
produce RFC 5424(4)-compliant messages.  If you don’t, logging may not
complain, but your messages will not be RFC 5424-compliant, and your
syslog daemon may complain.

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc5424.html

   (2) https://datatracker.ietf.org/doc/html/rfc5424.html#section-6

   (3) https://datatracker.ietf.org/doc/html/rfc5424.html

   (4) https://datatracker.ietf.org/doc/html/rfc5424.html


File: python.info,  Node: Implementing structured logging,  Next: Customizing handlers with dictConfig,  Prev: Inserting a BOM into messages sent to a SysLogHandler,  Up: Logging Cookbook

9.9.22 Implementing structured logging
--------------------------------------

Although most logging messages are intended for reading by humans, and
thus not readily machine-parseable, there might be circumstances where
you want to output messages in a structured format which 'is' capable of
being parsed by a program (without needing complex regular expressions
to parse the log message).  This is straightforward to achieve using the
logging package.  There are a number of ways in which this could be
achieved, but the following is a simple approach which uses JSON to
serialise the event in a machine-parseable manner:

     import json
     import logging

     class StructuredMessage:
         def __init__(self, message, /, **kwargs):
             self.message = message
             self.kwargs = kwargs

         def __str__(self):
             return '%s >>> %s' % (self.message, json.dumps(self.kwargs))

     _ = StructuredMessage   # optional, to improve readability

     logging.basicConfig(level=logging.INFO, format='%(message)s')
     logging.info(_('message 1', foo='bar', bar='baz', num=123, fnum=123.456))

If the above script is run, it prints:

     message 1 >>> {"fnum": 123.456, "num": 123, "bar": "baz", "foo": "bar"}

Note that the order of items might be different according to the version
of Python used.

If you need more specialised processing, you can use a custom JSON
encoder, as in the following complete example:

     import json
     import logging


     class Encoder(json.JSONEncoder):
         def default(self, o):
             if isinstance(o, set):
                 return tuple(o)
             elif isinstance(o, str):
                 return o.encode('unicode_escape').decode('ascii')
             return super().default(o)

     class StructuredMessage:
         def __init__(self, message, /, **kwargs):
             self.message = message
             self.kwargs = kwargs

         def __str__(self):
             s = Encoder().encode(self.kwargs)
             return '%s >>> %s' % (self.message, s)

     _ = StructuredMessage   # optional, to improve readability

     def main():
         logging.basicConfig(level=logging.INFO, format='%(message)s')
         logging.info(_('message 1', set_value={1, 2, 3}, snowman='\u2603'))

     if __name__ == '__main__':
         main()

When the above script is run, it prints:

     message 1 >>> {"snowman": "\u2603", "set_value": [1, 2, 3]}

Note that the order of items might be different according to the version
of Python used.


File: python.info,  Node: Customizing handlers with dictConfig,  Next: Using particular formatting styles throughout your application,  Prev: Implementing structured logging,  Up: Logging Cookbook

9.9.23 Customizing handlers with ‘dictConfig()’
-----------------------------------------------

There are times when you want to customize logging handlers in
particular ways, and if you use *note dictConfig(): 13b8. you may be
able to do this without subclassing.  As an example, consider that you
may want to set the ownership of a log file.  On POSIX, this is easily
done using *note shutil.chown(): 549, but the file handlers in the
stdlib don’t offer built-in support.  You can customize handler creation
using a plain function such as:

     def owned_file_handler(filename, mode='a', encoding=None, owner=None):
         if owner:
             if not os.path.exists(filename):
                 open(filename, 'a').close()
             shutil.chown(filename, *owner)
         return logging.FileHandler(filename, mode, encoding)

You can then specify, in a logging configuration passed to *note
dictConfig(): 13b8, that a logging handler be created by calling this
function:

     LOGGING = {
         'version': 1,
         'disable_existing_loggers': False,
         'formatters': {
             'default': {
                 'format': '%(asctime)s %(levelname)s %(name)s %(message)s'
             },
         },
         'handlers': {
             'file':{
                 # The values below are popped from this dictionary and
                 # used to create the handler, set the handler's level and
                 # its formatter.
                 '()': owned_file_handler,
                 'level':'DEBUG',
                 'formatter': 'default',
                 # The values below are passed to the handler creator callable
                 # as keyword arguments.
                 'owner': ['pulse', 'pulse'],
                 'filename': 'chowntest.log',
                 'mode': 'w',
                 'encoding': 'utf-8',
             },
         },
         'root': {
             'handlers': ['file'],
             'level': 'DEBUG',
         },
     }

In this example I am setting the ownership using the ‘pulse’ user and
group, just for the purposes of illustration.  Putting it together into
a working script, ‘chowntest.py’:

     import logging, logging.config, os, shutil

     def owned_file_handler(filename, mode='a', encoding=None, owner=None):
         if owner:
             if not os.path.exists(filename):
                 open(filename, 'a').close()
             shutil.chown(filename, *owner)
         return logging.FileHandler(filename, mode, encoding)

     LOGGING = {
         'version': 1,
         'disable_existing_loggers': False,
         'formatters': {
             'default': {
                 'format': '%(asctime)s %(levelname)s %(name)s %(message)s'
             },
         },
         'handlers': {
             'file':{
                 # The values below are popped from this dictionary and
                 # used to create the handler, set the handler's level and
                 # its formatter.
                 '()': owned_file_handler,
                 'level':'DEBUG',
                 'formatter': 'default',
                 # The values below are passed to the handler creator callable
                 # as keyword arguments.
                 'owner': ['pulse', 'pulse'],
                 'filename': 'chowntest.log',
                 'mode': 'w',
                 'encoding': 'utf-8',
             },
         },
         'root': {
             'handlers': ['file'],
             'level': 'DEBUG',
         },
     }

     logging.config.dictConfig(LOGGING)
     logger = logging.getLogger('mylogger')
     logger.debug('A debug message')

To run this, you will probably need to run as ‘root’:

     $ sudo python3.3 chowntest.py
     $ cat chowntest.log
     2013-11-05 09:34:51,128 DEBUG mylogger A debug message
     $ ls -l chowntest.log
     -rw-r--r-- 1 pulse pulse 55 2013-11-05 09:34 chowntest.log

Note that this example uses Python 3.3 because that’s where *note
shutil.chown(): 549. makes an appearance.  This approach should work
with any Python version that supports *note dictConfig(): 13b8. -
namely, Python 2.7, 3.2 or later.  With pre-3.3 versions, you would need
to implement the actual ownership change using e.g.  *note os.chown():
12f6.

In practice, the handler-creating function may be in a utility module
somewhere in your project.  Instead of the line in the configuration:

     '()': owned_file_handler,

you could use e.g.:

     '()': 'ext://project.util.owned_file_handler',

where ‘project.util’ can be replaced with the actual name of the package
where the function resides.  In the above working script, using
‘'ext://__main__.owned_file_handler'’ should work.  Here, the actual
callable is resolved by *note dictConfig(): 13b8. from the ‘ext://’
specification.

This example hopefully also points the way to how you could implement
other types of file change - e.g.  setting specific POSIX permission
bits - in the same way, using *note os.chmod(): 52a.

Of course, the approach could also be extended to types of handler other
than a *note FileHandler: 1c3b. - for example, one of the rotating file
handlers, or a different type of handler altogether.


File: python.info,  Node: Using particular formatting styles throughout your application,  Next: Configuring filters with dictConfig,  Prev: Customizing handlers with dictConfig,  Up: Logging Cookbook

9.9.24 Using particular formatting styles throughout your application
---------------------------------------------------------------------

In Python 3.2, the *note Formatter: 169e. gained a ‘style’ keyword
parameter which, while defaulting to ‘%’ for backward compatibility,
allowed the specification of ‘{’ or ‘$’ to support the formatting
approaches supported by *note str.format(): 834. and *note
string.Template: 898.  Note that this governs the formatting of logging
messages for final output to logs, and is completely orthogonal to how
an individual logging message is constructed.

Logging calls (*note debug(): 102d, *note info(): 3142. etc.)  only take
positional parameters for the actual logging message itself, with
keyword parameters used only for determining options for how to handle
the logging call (e.g.  the ‘exc_info’ keyword parameter to indicate
that traceback information should be logged, or the ‘extra’ keyword
parameter to indicate additional contextual information to be added to
the log).  So you cannot directly make logging calls using *note
str.format(): 834. or *note string.Template: 898. syntax, because
internally the logging package uses %-formatting to merge the format
string and the variable arguments.  There would be no changing this
while preserving backward compatibility, since all logging calls which
are out there in existing code will be using %-format strings.

There have been suggestions to associate format styles with specific
loggers, but that approach also runs into backward compatibility
problems because any existing code could be using a given logger name
and using %-formatting.

For logging to work interoperably between any third-party libraries and
your code, decisions about formatting need to be made at the level of
the individual logging call.  This opens up a couple of ways in which
alternative formatting styles can be accommodated.

* Menu:

* Using LogRecord factories::
* Using custom message objects::


File: python.info,  Node: Using LogRecord factories,  Next: Using custom message objects,  Up: Using particular formatting styles throughout your application

9.9.24.1 Using LogRecord factories
..................................

In Python 3.2, along with the *note Formatter: 169e. changes mentioned
above, the logging package gained the ability to allow users to set
their own *note LogRecord: 11e8. subclasses, using the *note
setLogRecordFactory(): 3174. function.  You can use this to set your own
subclass of *note LogRecord: 11e8, which does the Right Thing by
overriding the *note getMessage(): 3172. method.  The base class
implementation of this method is where the ‘msg % args’ formatting
happens, and where you can substitute your alternate formatting;
however, you should be careful to support all formatting styles and
allow %-formatting as the default, to ensure interoperability with other
code.  Care should also be taken to call ‘str(self.msg)’, just as the
base implementation does.

Refer to the reference documentation on *note setLogRecordFactory():
3174. and *note LogRecord: 11e8. for more information.


File: python.info,  Node: Using custom message objects,  Prev: Using LogRecord factories,  Up: Using particular formatting styles throughout your application

9.9.24.2 Using custom message objects
.....................................

There is another, perhaps simpler way that you can use {}- and $-
formatting to construct your individual log messages.  You may recall
(from *note Using arbitrary objects as messages: 3171.) that when
logging you can use an arbitrary object as a message format string, and
that the logging package will call *note str(): 169. on that object to
get the actual format string.  Consider the following two classes:

     class BraceMessage:
         def __init__(self, fmt, /, *args, **kwargs):
             self.fmt = fmt
             self.args = args
             self.kwargs = kwargs

         def __str__(self):
             return self.fmt.format(*self.args, **self.kwargs)

     class DollarMessage:
         def __init__(self, fmt, /, **kwargs):
             self.fmt = fmt
             self.kwargs = kwargs

         def __str__(self):
             from string import Template
             return Template(self.fmt).substitute(**self.kwargs)

Either of these can be used in place of a format string, to allow {}- or
$-formatting to be used to build the actual «message» part which appears
in the formatted log output in place of “%(message)s” or “{message}” or
“$message”.  If you find it a little unwieldy to use the class names
whenever you want to log something, you can make it more palatable if
you use an alias such as ‘M’ or ‘_’ for the message (or perhaps ‘__’, if
you are using ‘_’ for localization).

Examples of this approach are given below.  Firstly, formatting with
*note str.format(): 834.:

     >>> __ = BraceMessage
     >>> print(__('Message with {0} {1}', 2, 'placeholders'))
     Message with 2 placeholders
     >>> class Point: pass
     ...
     >>> p = Point()
     >>> p.x = 0.5
     >>> p.y = 0.5
     >>> print(__('Message with coordinates: ({point.x:.2f}, {point.y:.2f})', point=p))
     Message with coordinates: (0.50, 0.50)

Secondly, formatting with *note string.Template: 898.:

     >>> __ = DollarMessage
     >>> print(__('Message with $num $what', num=2, what='placeholders'))
     Message with 2 placeholders
     >>>

One thing to note is that you pay no significant performance penalty
with this approach: the actual formatting happens not when you make the
logging call, but when (and if) the logged message is actually about to
be output to a log by a handler.  So the only slightly unusual thing
which might trip you up is that the parentheses go around the format
string and the arguments, not just the format string.  That’s because
the __ notation is just syntax sugar for a constructor call to one of
the ‘XXXMessage’ classes shown above.


File: python.info,  Node: Configuring filters with dictConfig,  Next: Customized exception formatting,  Prev: Using particular formatting styles throughout your application,  Up: Logging Cookbook

9.9.25 Configuring filters with ‘dictConfig()’
----------------------------------------------

You 'can' configure filters using *note dictConfig(): 13b8, though it
might not be obvious at first glance how to do it (hence this recipe).
Since *note Filter: 1403. is the only filter class included in the
standard library, and it is unlikely to cater to many requirements (it’s
only there as a base class), you will typically need to define your own
*note Filter: 1403. subclass with an overridden *note filter(): 316b.
method.  To do this, specify the ‘()’ key in the configuration
dictionary for the filter, specifying a callable which will be used to
create the filter (a class is the most obvious, but you can provide any
callable which returns a *note Filter: 1403. instance).  Here is a
complete example:

     import logging
     import logging.config
     import sys

     class MyFilter(logging.Filter):
         def __init__(self, param=None):
             self.param = param

         def filter(self, record):
             if self.param is None:
                 allow = True
             else:
                 allow = self.param not in record.msg
             if allow:
                 record.msg = 'changed: ' + record.msg
             return allow

     LOGGING = {
         'version': 1,
         'filters': {
             'myfilter': {
                 '()': MyFilter,
                 'param': 'noshow',
             }
         },
         'handlers': {
             'console': {
                 'class': 'logging.StreamHandler',
                 'filters': ['myfilter']
             }
         },
         'root': {
             'level': 'DEBUG',
             'handlers': ['console']
         },
     }

     if __name__ == '__main__':
         logging.config.dictConfig(LOGGING)
         logging.debug('hello')
         logging.debug('hello - noshow')

This example shows how you can pass configuration data to the callable
which constructs the instance, in the form of keyword parameters.  When
run, the above script will print:

     changed: hello

which shows that the filter is working as configured.

A couple of extra points to note:

   * If you can’t refer to the callable directly in the configuration
     (e.g.  if it lives in a different module, and you can’t import it
     directly where the configuration dictionary is), you can use the
     form ‘ext://...’ as described in *note Access to external objects:
     31a0.  For example, you could have used the text
     ‘'ext://__main__.MyFilter'’ instead of ‘MyFilter’ in the above
     example.

   * As well as for filters, this technique can also be used to
     configure custom handlers and formatters.  See *note User-defined
     objects: 3194. for more information on how logging supports using
     user-defined objects in its configuration, and see the other
     cookbook recipe *note Customizing handlers with dictConfig(): 5765.
     above.


File: python.info,  Node: Customized exception formatting,  Next: Speaking logging messages,  Prev: Configuring filters with dictConfig,  Up: Logging Cookbook

9.9.26 Customized exception formatting
--------------------------------------

There might be times when you want to do customized exception formatting
- for argument’s sake, let’s say you want exactly one line per logged
event, even when exception information is present.  You can do this with
a custom formatter class, as shown in the following example:

     import logging

     class OneLineExceptionFormatter(logging.Formatter):
         def formatException(self, exc_info):
             """
             Format an exception so that it prints on a single line.
             """
             result = super().formatException(exc_info)
             return repr(result)  # or format into one line however you want to

         def format(self, record):
             s = super().format(record)
             if record.exc_text:
                 s = s.replace('\n', '') + '|'
             return s

     def configure_logging():
         fh = logging.FileHandler('output.txt', 'w')
         f = OneLineExceptionFormatter('%(asctime)s|%(levelname)s|%(message)s|',
                                       '%d/%m/%Y %H:%M:%S')
         fh.setFormatter(f)
         root = logging.getLogger()
         root.setLevel(logging.DEBUG)
         root.addHandler(fh)

     def main():
         configure_logging()
         logging.info('Sample message')
         try:
             x = 1 / 0
         except ZeroDivisionError as e:
             logging.exception('ZeroDivisionError: %s', e)

     if __name__ == '__main__':
         main()

When run, this produces a file with exactly two lines:

     28/01/2015 07:21:23|INFO|Sample message|
     28/01/2015 07:21:23|ERROR|ZeroDivisionError: division by zero|'Traceback (most recent call last):\n  File "logtest7.py", line 30, in main\n    x = 1 / 0\nZeroDivisionError: division by zero'|

While the above treatment is simplistic, it points the way to how
exception information can be formatted to your liking.  The *note
traceback: 104. module may be helpful for more specialized needs.


File: python.info,  Node: Speaking logging messages,  Next: Buffering logging messages and outputting them conditionally,  Prev: Customized exception formatting,  Up: Logging Cookbook

9.9.27 Speaking logging messages
--------------------------------

There might be situations when it is desirable to have logging messages
rendered in an audible rather than a visible format.  This is easy to do
if you have text-to-speech (TTS) functionality available in your system,
even if it doesn’t have a Python binding.  Most TTS systems have a
command line program you can run, and this can be invoked from a handler
using *note subprocess: dc.  It’s assumed here that TTS command line
programs won’t expect to interact with users or take a long time to
complete, and that the frequency of logged messages will be not so high
as to swamp the user with messages, and that it’s acceptable to have the
messages spoken one at a time rather than concurrently, The example
implementation below waits for one message to be spoken before the next
is processed, and this might cause other handlers to be kept waiting.
Here is a short example showing the approach, which assumes that the
‘espeak’ TTS package is available:

     import logging
     import subprocess
     import sys

     class TTSHandler(logging.Handler):
         def emit(self, record):
             msg = self.format(record)
             # Speak slowly in a female English voice
             cmd = ['espeak', '-s150', '-ven+f3', msg]
             p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
                                  stderr=subprocess.STDOUT)
             # wait for the program to finish
             p.communicate()

     def configure_logging():
         h = TTSHandler()
         root = logging.getLogger()
         root.addHandler(h)
         # the default formatter just returns the message
         root.setLevel(logging.DEBUG)

     def main():
         logging.info('Hello')
         logging.debug('Goodbye')

     if __name__ == '__main__':
         configure_logging()
         sys.exit(main())

When run, this script should say «Hello» and then «Goodbye» in a female
voice.

The above approach can, of course, be adapted to other TTS systems and
even other systems altogether which can process messages via external
programs run from a command line.


File: python.info,  Node: Buffering logging messages and outputting them conditionally,  Next: Sending logging messages to email with buffering,  Prev: Speaking logging messages,  Up: Logging Cookbook

9.9.28 Buffering logging messages and outputting them conditionally
-------------------------------------------------------------------

There might be situations where you want to log messages in a temporary
area and only output them if a certain condition occurs.  For example,
you may want to start logging debug events in a function, and if the
function completes without errors, you don’t want to clutter the log
with the collected debug information, but if there is an error, you want
all the debug information to be output as well as the error.

Here is an example which shows how you could do this using a decorator
for your functions where you want logging to behave this way.  It makes
use of the *note logging.handlers.MemoryHandler: 31a3, which allows
buffering of logged events until some condition occurs, at which point
the buffered events are ‘flushed’ - passed to another handler (the
‘target’ handler) for processing.  By default, the ‘MemoryHandler’
flushed when its buffer gets filled up or an event whose level is
greater than or equal to a specified threshold is seen.  You can use
this recipe with a more specialised subclass of ‘MemoryHandler’ if you
want custom flushing behavior.

The example script has a simple function, ‘foo’, which just cycles
through all the logging levels, writing to ‘sys.stderr’ to say what
level it’s about to log at, and then actually logging a message at that
level.  You can pass a parameter to ‘foo’ which, if true, will log at
ERROR and CRITICAL levels - otherwise, it only logs at DEBUG, INFO and
WARNING levels.

The script just arranges to decorate ‘foo’ with a decorator which will
do the conditional logging that’s required.  The decorator takes a
logger as a parameter and attaches a memory handler for the duration of
the call to the decorated function.  The decorator can be additionally
parameterised using a target handler, a level at which flushing should
occur, and a capacity for the buffer (number of records buffered).
These default to a *note StreamHandler: 1400. which writes to
‘sys.stderr’, ‘logging.ERROR’ and ‘100’ respectively.

Here’s the script:

     import logging
     from logging.handlers import MemoryHandler
     import sys

     logger = logging.getLogger(__name__)
     logger.addHandler(logging.NullHandler())

     def log_if_errors(logger, target_handler=None, flush_level=None, capacity=None):
         if target_handler is None:
             target_handler = logging.StreamHandler()
         if flush_level is None:
             flush_level = logging.ERROR
         if capacity is None:
             capacity = 100
         handler = MemoryHandler(capacity, flushLevel=flush_level, target=target_handler)

         def decorator(fn):
             def wrapper(*args, **kwargs):
                 logger.addHandler(handler)
                 try:
                     return fn(*args, **kwargs)
                 except Exception:
                     logger.exception('call failed')
                     raise
                 finally:
                     super(MemoryHandler, handler).flush()
                     logger.removeHandler(handler)
             return wrapper

         return decorator

     def write_line(s):
         sys.stderr.write('%s\n' % s)

     def foo(fail=False):
         write_line('about to log at DEBUG ...')
         logger.debug('Actually logged at DEBUG')
         write_line('about to log at INFO ...')
         logger.info('Actually logged at INFO')
         write_line('about to log at WARNING ...')
         logger.warning('Actually logged at WARNING')
         if fail:
             write_line('about to log at ERROR ...')
             logger.error('Actually logged at ERROR')
             write_line('about to log at CRITICAL ...')
             logger.critical('Actually logged at CRITICAL')
         return fail

     decorated_foo = log_if_errors(logger)(foo)

     if __name__ == '__main__':
         logger.setLevel(logging.DEBUG)
         write_line('Calling undecorated foo with False')
         assert not foo(False)
         write_line('Calling undecorated foo with True')
         assert foo(True)
         write_line('Calling decorated foo with False')
         assert not decorated_foo(False)
         write_line('Calling decorated foo with True')
         assert decorated_foo(True)

When this script is run, the following output should be observed:

     Calling undecorated foo with False
     about to log at DEBUG ...
     about to log at INFO ...
     about to log at WARNING ...
     Calling undecorated foo with True
     about to log at DEBUG ...
     about to log at INFO ...
     about to log at WARNING ...
     about to log at ERROR ...
     about to log at CRITICAL ...
     Calling decorated foo with False
     about to log at DEBUG ...
     about to log at INFO ...
     about to log at WARNING ...
     Calling decorated foo with True
     about to log at DEBUG ...
     about to log at INFO ...
     about to log at WARNING ...
     about to log at ERROR ...
     Actually logged at DEBUG
     Actually logged at INFO
     Actually logged at WARNING
     Actually logged at ERROR
     about to log at CRITICAL ...
     Actually logged at CRITICAL

As you can see, actual logging output only occurs when an event is
logged whose severity is ERROR or greater, but in that case, any
previous events at lower severities are also logged.

You can of course use the conventional means of decoration:

     @log_if_errors(logger)
     def foo(fail=False):
         ...


File: python.info,  Node: Sending logging messages to email with buffering,  Next: Formatting times using UTC GMT via configuration,  Prev: Buffering logging messages and outputting them conditionally,  Up: Logging Cookbook

9.9.29 Sending logging messages to email, with buffering
--------------------------------------------------------

To illustrate how you can send log messages via email, so that a set
number of messages are sent per email, you can subclass *note
BufferingHandler: 31f6.  In the following example, which you can adapt
to suit your specific needs, a simple test harness is provided which
allows you to run the script with command line arguments specifying what
you typically need to send things via SMTP. (Run the downloaded script
with the ‘-h’ argument to see the required and optional arguments.)

     import logging
     import logging.handlers
     import smtplib

     class BufferingSMTPHandler(logging.handlers.BufferingHandler):
         def __init__(self, mailhost, port, username, password, fromaddr, toaddrs,
                      subject, capacity):
             logging.handlers.BufferingHandler.__init__(self, capacity)
             self.mailhost = mailhost
             self.mailport = port
             self.username = username
             self.password = password
             self.fromaddr = fromaddr
             if isinstance(toaddrs, str):
                 toaddrs = [toaddrs]
             self.toaddrs = toaddrs
             self.subject = subject
             self.setFormatter(logging.Formatter("%(asctime)s %(levelname)-5s %(message)s"))

         def flush(self):
             if len(self.buffer) > 0:
                 try:
                     smtp = smtplib.SMTP(self.mailhost, self.mailport)
                     smtp.starttls()
                     smtp.login(self.username, self.password)
                     msg = "From: %s\r\nTo: %s\r\nSubject: %s\r\n\r\n" % (self.fromaddr, ','.join(self.toaddrs), self.subject)
                     for record in self.buffer:
                         s = self.format(record)
                         msg = msg + s + "\r\n"
                     smtp.sendmail(self.fromaddr, self.toaddrs, msg)
                     smtp.quit()
                 except Exception:
                     if logging.raiseExceptions:
                         raise
                 self.buffer = []

     if __name__ == '__main__':
         import argparse

         ap = argparse.ArgumentParser()
         aa = ap.add_argument
         aa('host', metavar='HOST', help='SMTP server')
         aa('--port', '-p', type=int, default=587, help='SMTP port')
         aa('user', metavar='USER', help='SMTP username')
         aa('password', metavar='PASSWORD', help='SMTP password')
         aa('to', metavar='TO', help='Addressee for emails')
         aa('sender', metavar='SENDER', help='Sender email address')
         aa('--subject', '-s',
            default='Test Logging email from Python logging module (buffering)',
            help='Subject of email')
         options = ap.parse_args()
         logger = logging.getLogger()
         logger.setLevel(logging.DEBUG)
         h = BufferingSMTPHandler(options.host, options.port, options.user,
                                  options.password, options.sender,
                                  options.to, options.subject, 10)
         logger.addHandler(h)
         for i in range(102):
             logger.info("Info index = %d", i)
         h.flush()
         h.close()

If you run this script and your SMTP server is correctly set up, you
should find that it sends eleven emails to the addressee you specify.
The first ten emails will each have ten log messages, and the eleventh
will have two messages.  That makes up 102 messages as specified in the
script.


File: python.info,  Node: Formatting times using UTC GMT via configuration,  Next: Using a context manager for selective logging,  Prev: Sending logging messages to email with buffering,  Up: Logging Cookbook

9.9.30 Formatting times using UTC (GMT) via configuration
---------------------------------------------------------

Sometimes you want to format times using UTC, which can be done using a
class such as ‘UTCFormatter’, shown below:

     import logging
     import time

     class UTCFormatter(logging.Formatter):
         converter = time.gmtime

and you can then use the ‘UTCFormatter’ in your code instead of *note
Formatter: 169e.  If you want to do that via configuration, you can use
the *note dictConfig(): 13b8. API with an approach illustrated by the
following complete example:

     import logging
     import logging.config
     import time

     class UTCFormatter(logging.Formatter):
         converter = time.gmtime

     LOGGING = {
         'version': 1,
         'disable_existing_loggers': False,
         'formatters': {
             'utc': {
                 '()': UTCFormatter,
                 'format': '%(asctime)s %(message)s',
             },
             'local': {
                 'format': '%(asctime)s %(message)s',
             }
         },
         'handlers': {
             'console1': {
                 'class': 'logging.StreamHandler',
                 'formatter': 'utc',
             },
             'console2': {
                 'class': 'logging.StreamHandler',
                 'formatter': 'local',
             },
         },
         'root': {
             'handlers': ['console1', 'console2'],
        }
     }

     if __name__ == '__main__':
         logging.config.dictConfig(LOGGING)
         logging.warning('The local time is %s', time.asctime())

When this script is run, it should print something like:

     2015-10-17 12:53:29,501 The local time is Sat Oct 17 13:53:29 2015
     2015-10-17 13:53:29,501 The local time is Sat Oct 17 13:53:29 2015

showing how the time is formatted both as local time and UTC, one for
each handler.


File: python.info,  Node: Using a context manager for selective logging,  Next: A CLI application starter template,  Prev: Formatting times using UTC GMT via configuration,  Up: Logging Cookbook

9.9.31 Using a context manager for selective logging
----------------------------------------------------

There are times when it would be useful to temporarily change the
logging configuration and revert it back after doing something.  For
this, a context manager is the most obvious way of saving and restoring
the logging context.  Here is a simple example of such a context
manager, which allows you to optionally change the logging level and add
a logging handler purely in the scope of the context manager:

     import logging
     import sys

     class LoggingContext:
         def __init__(self, logger, level=None, handler=None, close=True):
             self.logger = logger
             self.level = level
             self.handler = handler
             self.close = close

         def __enter__(self):
             if self.level is not None:
                 self.old_level = self.logger.level
                 self.logger.setLevel(self.level)
             if self.handler:
                 self.logger.addHandler(self.handler)

         def __exit__(self, et, ev, tb):
             if self.level is not None:
                 self.logger.setLevel(self.old_level)
             if self.handler:
                 self.logger.removeHandler(self.handler)
             if self.handler and self.close:
                 self.handler.close()
             # implicit return of None => don't swallow exceptions

If you specify a level value, the logger’s level is set to that value in
the scope of the with block covered by the context manager.  If you
specify a handler, it is added to the logger on entry to the block and
removed on exit from the block.  You can also ask the manager to close
the handler for you on block exit - you could do this if you don’t need
the handler any more.

To illustrate how it works, we can add the following block of code to
the above:

     if __name__ == '__main__':
         logger = logging.getLogger('foo')
         logger.addHandler(logging.StreamHandler())
         logger.setLevel(logging.INFO)
         logger.info('1. This should appear just once on stderr.')
         logger.debug('2. This should not appear.')
         with LoggingContext(logger, level=logging.DEBUG):
             logger.debug('3. This should appear once on stderr.')
         logger.debug('4. This should not appear.')
         h = logging.StreamHandler(sys.stdout)
         with LoggingContext(logger, level=logging.DEBUG, handler=h, close=True):
             logger.debug('5. This should appear twice - once on stderr and once on stdout.')
         logger.info('6. This should appear just once on stderr.')
         logger.debug('7. This should not appear.')

We initially set the logger’s level to ‘INFO’, so message #1 appears and
message #2 doesn’t.  We then change the level to ‘DEBUG’ temporarily in
the following ‘with’ block, and so message #3 appears.  After the block
exits, the logger’s level is restored to ‘INFO’ and so message #4
doesn’t appear.  In the next ‘with’ block, we set the level to ‘DEBUG’
again but also add a handler writing to ‘sys.stdout’.  Thus, message #5
appears twice on the console (once via ‘stderr’ and once via ‘stdout’).
After the ‘with’ statement’s completion, the status is as it was before
so message #6 appears (like message #1) whereas message #7 doesn’t (just
like message #2).

If we run the resulting script, the result is as follows:

     $ python logctx.py
     1. This should appear just once on stderr.
     3. This should appear once on stderr.
     5. This should appear twice - once on stderr and once on stdout.
     5. This should appear twice - once on stderr and once on stdout.
     6. This should appear just once on stderr.

If we run it again, but pipe ‘stderr’ to ‘/dev/null’, we see the
following, which is the only message written to ‘stdout’:

     $ python logctx.py 2>/dev/null
     5. This should appear twice - once on stderr and once on stdout.

Once again, but piping ‘stdout’ to ‘/dev/null’, we get:

     $ python logctx.py >/dev/null
     1. This should appear just once on stderr.
     3. This should appear once on stderr.
     5. This should appear twice - once on stderr and once on stdout.
     6. This should appear just once on stderr.

In this case, the message #5 printed to ‘stdout’ doesn’t appear, as
expected.

Of course, the approach described here can be generalised, for example
to attach logging filters temporarily.  Note that the above code works
in Python 2 as well as Python 3.


File: python.info,  Node: A CLI application starter template,  Next: A Qt GUI for logging,  Prev: Using a context manager for selective logging,  Up: Logging Cookbook

9.9.32 A CLI application starter template
-----------------------------------------

Here’s an example which shows how you can:

   * Use a logging level based on command-line arguments

   * Dispatch to multiple subcommands in separate files, all logging at
     the same level in a consistent way

   * Make use of simple, minimal configuration

Suppose we have a command-line application whose job is to stop, start
or restart some services.  This could be organised for the purposes of
illustration as a file ‘app.py’ that is the main script for the
application, with individual commands implemented in ‘start.py’,
‘stop.py’ and ‘restart.py’.  Suppose further that we want to control the
verbosity of the application via a command-line argument, defaulting to
‘logging.INFO’.  Here’s one way that ‘app.py’ could be written:

     import argparse
     import importlib
     import logging
     import os
     import sys

     def main(args=None):
         scriptname = os.path.basename(__file__)
         parser = argparse.ArgumentParser(scriptname)
         levels = ('DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL')
         parser.add_argument('--log-level', default='INFO', choices=levels)
         subparsers = parser.add_subparsers(dest='command',
                                            help='Available commands:')
         start_cmd = subparsers.add_parser('start', help='Start a service')
         start_cmd.add_argument('name', metavar='NAME',
                                help='Name of service to start')
         stop_cmd = subparsers.add_parser('stop',
                                          help='Stop one or more services')
         stop_cmd.add_argument('names', metavar='NAME', nargs='+',
                               help='Name of service to stop')
         restart_cmd = subparsers.add_parser('restart',
                                             help='Restart one or more services')
         restart_cmd.add_argument('names', metavar='NAME', nargs='+',
                                  help='Name of service to restart')
         options = parser.parse_args()
         # the code to dispatch commands could all be in this file. For the purposes
         # of illustration only, we implement each command in a separate module.
         try:
             mod = importlib.import_module(options.command)
             cmd = getattr(mod, 'command')
         except (ImportError, AttributeError):
             print('Unable to find the code for command \'%s\'' % options.command)
             return 1
         # Could get fancy here and load configuration from file or dictionary
         logging.basicConfig(level=options.log_level,
                             format='%(levelname)s %(name)s %(message)s')
         cmd(options)

     if __name__ == '__main__':
         sys.exit(main())

And the ‘start’, ‘stop’ and ‘restart’ commands can be implemented in
separate modules, like so for starting:

     # start.py
     import logging

     logger = logging.getLogger(__name__)

     def command(options):
         logger.debug('About to start %s', options.name)
         # actually do the command processing here ...
         logger.info('Started the \'%s\' service.', options.name)

and thus for stopping:

     # stop.py
     import logging

     logger = logging.getLogger(__name__)

     def command(options):
         n = len(options.names)
         if n == 1:
             plural = ''
             services = '\'%s\'' % options.names[0]
         else:
             plural = 's'
             services = ', '.join('\'%s\'' % name for name in options.names)
             i = services.rfind(', ')
             services = services[:i] + ' and ' + services[i + 2:]
         logger.debug('About to stop %s', services)
         # actually do the command processing here ...
         logger.info('Stopped the %s service%s.', services, plural)

and similarly for restarting:

     # restart.py
     import logging

     logger = logging.getLogger(__name__)

     def command(options):
         n = len(options.names)
         if n == 1:
             plural = ''
             services = '\'%s\'' % options.names[0]
         else:
             plural = 's'
             services = ', '.join('\'%s\'' % name for name in options.names)
             i = services.rfind(', ')
             services = services[:i] + ' and ' + services[i + 2:]
         logger.debug('About to restart %s', services)
         # actually do the command processing here ...
         logger.info('Restarted the %s service%s.', services, plural)

If we run this application with the default log level, we get output
like this:

     $ python app.py start foo
     INFO start Started the 'foo' service.

     $ python app.py stop foo bar
     INFO stop Stopped the 'foo' and 'bar' services.

     $ python app.py restart foo bar baz
     INFO restart Restarted the 'foo', 'bar' and 'baz' services.

The first word is the logging level, and the second word is the module
or package name of the place where the event was logged.

If we change the logging level, then we can change the information sent
to the log.  For example, if we want more information:

     $ python app.py --log-level DEBUG start foo
     DEBUG start About to start foo
     INFO start Started the 'foo' service.

     $ python app.py --log-level DEBUG stop foo bar
     DEBUG stop About to stop 'foo' and 'bar'
     INFO stop Stopped the 'foo' and 'bar' services.

     $ python app.py --log-level DEBUG restart foo bar baz
     DEBUG restart About to restart 'foo', 'bar' and 'baz'
     INFO restart Restarted the 'foo', 'bar' and 'baz' services.

And if we want less:

     $ python app.py --log-level WARNING start foo
     $ python app.py --log-level WARNING stop foo bar
     $ python app.py --log-level WARNING restart foo bar baz

In this case, the commands don’t print anything to the console, since
nothing at ‘WARNING’ level or above is logged by them.


File: python.info,  Node: A Qt GUI for logging,  Next: Logging to syslog with RFC5424 support,  Prev: A CLI application starter template,  Up: Logging Cookbook

9.9.33 A Qt GUI for logging
---------------------------

A question that comes up from time to time is about how to log to a GUI
application.  The Qt(1) framework is a popular cross-platform UI
framework with Python bindings using PySide2(2) or PyQt5(3) libraries.

The following example shows how to log to a Qt GUI. This introduces a
simple ‘QtHandler’ class which takes a callable, which should be a slot
in the main thread that does GUI updates.  A worker thread is also
created to show how you can log to the GUI from both the UI itself (via
a button for manual logging) as well as a worker thread doing work in
the background (here, just logging messages at random levels with random
short delays in between).

The worker thread is implemented using Qt’s ‘QThread’ class rather than
the *note threading: f3. module, as there are circumstances where one
has to use ‘QThread’, which offers better integration with other ‘Qt’
components.

The code should work with recent releases of any of ‘PySide6’, ‘PyQt6’,
‘PySide2’ or ‘PyQt5’.  You should be able to adapt the approach to
earlier versions of Qt.  Please refer to the comments in the code
snippet for more detailed information.

     import datetime
     import logging
     import random
     import sys
     import time

     # Deal with minor differences between different Qt packages
     try:
         from PySide6 import QtCore, QtGui, QtWidgets
         Signal = QtCore.Signal
         Slot = QtCore.Slot
     except ImportError:
         try:
             from PyQt6 import QtCore, QtGui, QtWidgets
             Signal = QtCore.pyqtSignal
             Slot = QtCore.pyqtSlot
         except ImportError:
             try:
                 from PySide2 import QtCore, QtGui, QtWidgets
                 Signal = QtCore.Signal
                 Slot = QtCore.Slot
             except ImportError:
                 from PyQt5 import QtCore, QtGui, QtWidgets
                 Signal = QtCore.pyqtSignal
                 Slot = QtCore.pyqtSlot

     logger = logging.getLogger(__name__)


     #
     # Signals need to be contained in a QObject or subclass in order to be correctly
     # initialized.
     #
     class Signaller(QtCore.QObject):
         signal = Signal(str, logging.LogRecord)

     #
     # Output to a Qt GUI is only supposed to happen on the main thread. So, this
     # handler is designed to take a slot function which is set up to run in the main
     # thread. In this example, the function takes a string argument which is a
     # formatted log message, and the log record which generated it. The formatted
     # string is just a convenience - you could format a string for output any way
     # you like in the slot function itself.
     #
     # You specify the slot function to do whatever GUI updates you want. The handler
     # doesn't know or care about specific UI elements.
     #
     class QtHandler(logging.Handler):
         def __init__(self, slotfunc, *args, **kwargs):
             super().__init__(*args, **kwargs)
             self.signaller = Signaller()
             self.signaller.signal.connect(slotfunc)

         def emit(self, record):
             s = self.format(record)
             self.signaller.signal.emit(s, record)

     #
     # This example uses QThreads, which means that the threads at the Python level
     # are named something like "Dummy-1". The function below gets the Qt name of the
     # current thread.
     #
     def ctname():
         return QtCore.QThread.currentThread().objectName()


     #
     # Used to generate random levels for logging.
     #
     LEVELS = (logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR,
               logging.CRITICAL)

     #
     # This worker class represents work that is done in a thread separate to the
     # main thread. The way the thread is kicked off to do work is via a button press
     # that connects to a slot in the worker.
     #
     # Because the default threadName value in the LogRecord isn't much use, we add
     # a qThreadName which contains the QThread name as computed above, and pass that
     # value in an "extra" dictionary which is used to update the LogRecord with the
     # QThread name.
     #
     # This example worker just outputs messages sequentially, interspersed with
     # random delays of the order of a few seconds.
     #
     class Worker(QtCore.QObject):
         @Slot()
         def start(self):
             extra = {'qThreadName': ctname() }
             logger.debug('Started work', extra=extra)
             i = 1
             # Let the thread run until interrupted. This allows reasonably clean
             # thread termination.
             while not QtCore.QThread.currentThread().isInterruptionRequested():
                 delay = 0.5 + random.random() * 2
                 time.sleep(delay)
                 try:
                     if random.random() < 0.1:
                         raise ValueError('Exception raised: %d' % i)
                     else:
                         level = random.choice(LEVELS)
                         logger.log(level, 'Message after delay of %3.1f: %d', delay, i, extra=extra)
                 except ValueError as e:
                     logger.exception('Failed: %s', e, extra=extra)
                 i += 1

     #
     # Implement a simple UI for this cookbook example. This contains:
     #
     # * A read-only text edit window which holds formatted log messages
     # * A button to start work and log stuff in a separate thread
     # * A button to log something from the main thread
     # * A button to clear the log window
     #
     class Window(QtWidgets.QWidget):

         COLORS = {
             logging.DEBUG: 'black',
             logging.INFO: 'blue',
             logging.WARNING: 'orange',
             logging.ERROR: 'red',
             logging.CRITICAL: 'purple',
         }

         def __init__(self, app):
             super().__init__()
             self.app = app
             self.textedit = te = QtWidgets.QPlainTextEdit(self)
             # Set whatever the default monospace font is for the platform
             f = QtGui.QFont('nosuchfont')
             if hasattr(f, 'Monospace'):
                 f.setStyleHint(f.Monospace)
             else:
                 f.setStyleHint(f.StyleHint.Monospace)  # for Qt6
             te.setFont(f)
             te.setReadOnly(True)
             PB = QtWidgets.QPushButton
             self.work_button = PB('Start background work', self)
             self.log_button = PB('Log a message at a random level', self)
             self.clear_button = PB('Clear log window', self)
             self.handler = h = QtHandler(self.update_status)
             # Remember to use qThreadName rather than threadName in the format string.
             fs = '%(asctime)s %(qThreadName)-12s %(levelname)-8s %(message)s'
             formatter = logging.Formatter(fs)
             h.setFormatter(formatter)
             logger.addHandler(h)
             # Set up to terminate the QThread when we exit
             app.aboutToQuit.connect(self.force_quit)

             # Lay out all the widgets
             layout = QtWidgets.QVBoxLayout(self)
             layout.addWidget(te)
             layout.addWidget(self.work_button)
             layout.addWidget(self.log_button)
             layout.addWidget(self.clear_button)
             self.setFixedSize(900, 400)

             # Connect the non-worker slots and signals
             self.log_button.clicked.connect(self.manual_update)
             self.clear_button.clicked.connect(self.clear_display)

             # Start a new worker thread and connect the slots for the worker
             self.start_thread()
             self.work_button.clicked.connect(self.worker.start)
             # Once started, the button should be disabled
             self.work_button.clicked.connect(lambda : self.work_button.setEnabled(False))

         def start_thread(self):
             self.worker = Worker()
             self.worker_thread = QtCore.QThread()
             self.worker.setObjectName('Worker')
             self.worker_thread.setObjectName('WorkerThread')  # for qThreadName
             self.worker.moveToThread(self.worker_thread)
             # This will start an event loop in the worker thread
             self.worker_thread.start()

         def kill_thread(self):
             # Just tell the worker to stop, then tell it to quit and wait for that
             # to happen
             self.worker_thread.requestInterruption()
             if self.worker_thread.isRunning():
                 self.worker_thread.quit()
                 self.worker_thread.wait()
             else:
                 print('worker has already exited.')

         def force_quit(self):
             # For use when the window is closed
             if self.worker_thread.isRunning():
                 self.kill_thread()

         # The functions below update the UI and run in the main thread because
         # that's where the slots are set up

         @Slot(str, logging.LogRecord)
         def update_status(self, status, record):
             color = self.COLORS.get(record.levelno, 'black')
             s = '<pre><font color="%s">%s</font></pre>' % (color, status)
             self.textedit.appendHtml(s)

         @Slot()
         def manual_update(self):
             # This function uses the formatted message passed in, but also uses
             # information from the record to format the message in an appropriate
             # color according to its severity (level).
             level = random.choice(LEVELS)
             extra = {'qThreadName': ctname() }
             logger.log(level, 'Manually logged!', extra=extra)

         @Slot()
         def clear_display(self):
             self.textedit.clear()


     def main():
         QtCore.QThread.currentThread().setObjectName('MainThread')
         logging.getLogger().setLevel(logging.DEBUG)
         app = QtWidgets.QApplication(sys.argv)
         example = Window(app)
         example.show()
         if hasattr(app, 'exec'):
             rc = app.exec()
         else:
             rc = app.exec_()
         sys.exit(rc)

     if __name__=='__main__':
         main()

   ---------- Footnotes ----------

   (1) https://www.qt.io/

   (2) https://pypi.org/project/PySide2/

   (3) https://pypi.org/project/PyQt5/


File: python.info,  Node: Logging to syslog with RFC5424 support,  Next: How to treat a logger like an output stream,  Prev: A Qt GUI for logging,  Up: Logging Cookbook

9.9.34 Logging to syslog with RFC5424 support
---------------------------------------------

Although RFC 5424(1) dates from 2009, most syslog servers are configured
by default to use the older RFC 3164(2), which hails from 2001.  When
‘logging’ was added to Python in 2003, it supported the earlier (and
only existing) protocol at the time.  Since RFC5424 came out, as there
has not been widespread deployment of it in syslog servers, the *note
SysLogHandler: 86d. functionality has not been updated.

RFC 5424 contains some useful features such as support for structured
data, and if you need to be able to log to a syslog server with support
for it, you can do so with a subclassed handler which looks something
like this:

     import datetime
     import logging.handlers
     import re
     import socket
     import time

     class SysLogHandler5424(logging.handlers.SysLogHandler):

         tz_offset = re.compile(r'([+-]\d{2})(\d{2})$')
         escaped = re.compile(r'([\]"\\])')

         def __init__(self, *args, **kwargs):
             self.msgid = kwargs.pop('msgid', None)
             self.appname = kwargs.pop('appname', None)
             super().__init__(*args, **kwargs)

         def format(self, record):
             version = 1
             asctime = datetime.datetime.fromtimestamp(record.created).isoformat()
             m = self.tz_offset.match(time.strftime('%z'))
             has_offset = False
             if m and time.timezone:
                 hrs, mins = m.groups()
                 if int(hrs) or int(mins):
                     has_offset = True
             if not has_offset:
                 asctime += 'Z'
             else:
                 asctime += f'{hrs}:{mins}'
             try:
                 hostname = socket.gethostname()
             except Exception:
                 hostname = '-'
             appname = self.appname or '-'
             procid = record.process
             msgid = '-'
             msg = super().format(record)
             sdata = '-'
             if hasattr(record, 'structured_data'):
                 sd = record.structured_data
                 # This should be a dict where the keys are SD-ID and the value is a
                 # dict mapping PARAM-NAME to PARAM-VALUE (refer to the RFC for what these
                 # mean)
                 # There's no error checking here - it's purely for illustration, and you
                 # can adapt this code for use in production environments
                 parts = []

                 def replacer(m):
                     g = m.groups()
                     return '\\' + g[0]

                 for sdid, dv in sd.items():
                     part = f'[{sdid}'
                     for k, v in dv.items():
                         s = str(v)
                         s = self.escaped.sub(replacer, s)
                         part += f' {k}="{s}"'
                     part += ']'
                     parts.append(part)
                 sdata = ''.join(parts)
             return f'{version} {asctime} {hostname} {appname} {procid} {msgid} {sdata} {msg}'

You’ll need to be familiar with RFC 5424 to fully understand the above
code, and it may be that you have slightly different needs (e.g.  for
how you pass structural data to the log).  Nevertheless, the above
should be adaptable to your speciric needs.  With the above handler,
you’d pass structured data using something like this:

     sd = {
         'foo@12345': {'bar': 'baz', 'baz': 'bozz', 'fizz': r'buzz'},
         'foo@54321': {'rab': 'baz', 'zab': 'bozz', 'zzif': r'buzz'}
     }
     extra = {'structured_data': sd}
     i = 1
     logger.debug('Message %d', i, extra=extra)

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc5424.html

   (2) https://datatracker.ietf.org/doc/html/rfc3164.html


File: python.info,  Node: How to treat a logger like an output stream,  Next: How to uniformly handle newlines in logging output,  Prev: Logging to syslog with RFC5424 support,  Up: Logging Cookbook

9.9.35 How to treat a logger like an output stream
--------------------------------------------------

Sometimes, you need to interface to a third-party API which expects a
file-like object to write to, but you want to direct the API’s output to
a logger.  You can do this using a class which wraps a logger with a
file-like API. Here’s a short script illustrating such a class:

     import logging

     class LoggerWriter:
         def __init__(self, logger, level):
             self.logger = logger
             self.level = level

         def write(self, message):
             if message != '\n':  # avoid printing bare newlines, if you like
                 self.logger.log(self.level, message)

         def flush(self):
             # doesn't actually do anything, but might be expected of a file-like
             # object - so optional depending on your situation
             pass

         def close(self):
             # doesn't actually do anything, but might be expected of a file-like
             # object - so optional depending on your situation. You might want
             # to set a flag so that later calls to write raise an exception
             pass

     def main():
         logging.basicConfig(level=logging.DEBUG)
         logger = logging.getLogger('demo')
         info_fp = LoggerWriter(logger, logging.INFO)
         debug_fp = LoggerWriter(logger, logging.DEBUG)
         print('An INFO message', file=info_fp)
         print('A DEBUG message', file=debug_fp)

     if __name__ == "__main__":
         main()

When this script is run, it prints

     INFO:demo:An INFO message
     DEBUG:demo:A DEBUG message

You could also use ‘LoggerWriter’ to redirect ‘sys.stdout’ and
‘sys.stderr’ by doing something like this:

     import sys

     sys.stdout = LoggerWriter(logger, logging.INFO)
     sys.stderr = LoggerWriter(logger, logging.WARNING)

You should do this 'after' configuring logging for your needs.  In the
above example, the *note basicConfig(): bf5. call does this (using the
‘sys.stderr’ value 'before' it is overwritten by a ‘LoggerWriter’
instance).  Then, you’d get this kind of result:

     >>> print('Foo')
     INFO:demo:Foo
     >>> print('Bar', file=sys.stderr)
     WARNING:demo:Bar
     >>>

Of course, the examples above show output according to the format used
by *note basicConfig(): bf5, but you can use a different formatter when
you configure logging.

Note that with the above scheme, you are somewhat at the mercy of
buffering and the sequence of write calls which you are intercepting.
For example, with the definition of ‘LoggerWriter’ above, if you have
the snippet

     sys.stderr = LoggerWriter(logger, logging.WARNING)
     1 / 0

then running the script results in

     WARNING:demo:Traceback (most recent call last):

     WARNING:demo:  File "/home/runner/cookbook-loggerwriter/test.py", line 53, in <module>

     WARNING:demo:
     WARNING:demo:main()
     WARNING:demo:  File "/home/runner/cookbook-loggerwriter/test.py", line 49, in main

     WARNING:demo:
     WARNING:demo:1 / 0
     WARNING:demo:ZeroDivisionError
     WARNING:demo::
     WARNING:demo:division by zero

As you can see, this output isn’t ideal.  That’s because the underlying
code which writes to ‘sys.stderr’ makes multiple writes, each of which
results in a separate logged line (for example, the last three lines
above).  To get around this problem, you need to buffer things and only
output log lines when newlines are seen.  Let’s use a slightly better
implementation of ‘LoggerWriter’:

     class BufferingLoggerWriter(LoggerWriter):
         def __init__(self, logger, level):
             super().__init__(logger, level)
             self.buffer = ''

         def write(self, message):
             if '\n' not in message:
                 self.buffer += message
             else:
                 parts = message.split('\n')
                 if self.buffer:
                     s = self.buffer + parts.pop(0)
                     self.logger.log(self.level, s)
                 self.buffer = parts.pop()
                 for part in parts:
                     self.logger.log(self.level, part)

This just buffers up stuff until a newline is seen, and then logs
complete lines.  With this approach, you get better output:

     WARNING:demo:Traceback (most recent call last):
     WARNING:demo:  File "/home/runner/cookbook-loggerwriter/main.py", line 55, in <module>
     WARNING:demo:    main()
     WARNING:demo:  File "/home/runner/cookbook-loggerwriter/main.py", line 52, in main
     WARNING:demo:    1/0
     WARNING:demo:ZeroDivisionError: division by zero


File: python.info,  Node: How to uniformly handle newlines in logging output,  Next: Patterns to avoid,  Prev: How to treat a logger like an output stream,  Up: Logging Cookbook

9.9.36 How to uniformly handle newlines in logging output
---------------------------------------------------------

Usually, messages that are logged (say to console or file) consist of a
single line of text.  However, sometimes there is a need to handle
messages with multiple lines - whether because a logging format string
contains newlines, or logged data contains newlines.  If you want to
handle such messages uniformly, so that each line in the logged message
appears uniformly formatted as if it was logged separately, you can do
this using a handler mixin, as in the following snippet:

     # Assume this is in a module mymixins.py
     import copy

     class MultilineMixin:
         def emit(self, record):
             s = record.getMessage()
             if '\n' not in s:
                 super().emit(record)
             else:
                 lines = s.splitlines()
                 rec = copy.copy(record)
                 rec.args = None
                 for line in lines:
                     rec.msg = line
                     super().emit(rec)

You can use the mixin as in the following script:

     import logging

     from mymixins import MultilineMixin

     logger = logging.getLogger(__name__)

     class StreamHandler(MultilineMixin, logging.StreamHandler):
         pass

     if __name__ == '__main__':
         logging.basicConfig(level=logging.DEBUG, format='%(asctime)s %(levelname)-9s %(message)s',
                             handlers = [StreamHandler()])
         logger.debug('Single line')
         logger.debug('Multiple lines:\nfool me once ...')
         logger.debug('Another single line')
         logger.debug('Multiple lines:\n%s', 'fool me ...\ncan\'t get fooled again')

The script, when run, prints something like:

     2025-07-02 13:54:47,234 DEBUG     Single line
     2025-07-02 13:54:47,234 DEBUG     Multiple lines:
     2025-07-02 13:54:47,234 DEBUG     fool me once ...
     2025-07-02 13:54:47,234 DEBUG     Another single line
     2025-07-02 13:54:47,234 DEBUG     Multiple lines:
     2025-07-02 13:54:47,234 DEBUG     fool me ...
     2025-07-02 13:54:47,234 DEBUG     can't get fooled again

If, on the other hand, you are concerned about log injection(1), you can
use a formatter which escapes newlines, as per the following example:

     import logging

     logger = logging.getLogger(__name__)

     class EscapingFormatter(logging.Formatter):
         def format(self, record):
             s = super().format(record)
             return s.replace('\n', r'\n')

     if __name__ == '__main__':
         h = logging.StreamHandler()
         h.setFormatter(EscapingFormatter('%(asctime)s %(levelname)-9s %(message)s'))
         logging.basicConfig(level=logging.DEBUG, handlers = [h])
         logger.debug('Single line')
         logger.debug('Multiple lines:\nfool me once ...')
         logger.debug('Another single line')
         logger.debug('Multiple lines:\n%s', 'fool me ...\ncan\'t get fooled again')

You can, of course, use whatever escaping scheme makes the most sense
for you.  The script, when run, should produce output like this:

     2025-07-09 06:47:33,783 DEBUG     Single line
     2025-07-09 06:47:33,783 DEBUG     Multiple lines:\nfool me once ...
     2025-07-09 06:47:33,783 DEBUG     Another single line
     2025-07-09 06:47:33,783 DEBUG     Multiple lines:\nfool me ...\ncan't get fooled again

Escaping behaviour can’t be the stdlib default , as it would break
backwards compatibility.

   ---------- Footnotes ----------

   (1) https://owasp.org/www-community/attacks/Log_Injection


File: python.info,  Node: Patterns to avoid,  Next: Other resources<2>,  Prev: How to uniformly handle newlines in logging output,  Up: Logging Cookbook

9.9.37 Patterns to avoid
------------------------

Although the preceding sections have described ways of doing things you
might need to do or deal with, it is worth mentioning some usage
patterns which are 'unhelpful', and which should therefore be avoided in
most cases.  The following sections are in no particular order.

* Menu:

* Opening the same log file multiple times::
* Using loggers as attributes in a class or passing them as parameters::
* Adding handlers other than NullHandler to a logger in a library::
* Creating a lot of loggers::


File: python.info,  Node: Opening the same log file multiple times,  Next: Using loggers as attributes in a class or passing them as parameters,  Up: Patterns to avoid

9.9.37.1 Opening the same log file multiple times
.................................................

On Windows, you will generally not be able to open the same file
multiple times as this will lead to a «file is in use by another
process» error.  However, on POSIX platforms you’ll not get any errors
if you open the same file multiple times.  This could be done
accidentally, for example by:

   * Adding a file handler more than once which references the same file
     (e.g.  by a copy/paste/forget-to-change error).

   * Opening two files that look different, as they have different
     names, but are the same because one is a symbolic link to the
     other.

   * Forking a process, following which both parent and child have a
     reference to the same file.  This might be through use of the *note
     multiprocessing: 98. module, for example.

Opening a file multiple times might 'appear' to work most of the time,
but can lead to a number of problems in practice:

   * Logging output can be garbled because multiple threads or processes
     try to write to the same file.  Although logging guards against
     concurrent use of the same handler instance by multiple threads,
     there is no such protection if concurrent writes are attempted by
     two different threads using two different handler instances which
     happen to point to the same file.

   * An attempt to delete a file (e.g.  during file rotation) silently
     fails, because there is another reference pointing to it.  This can
     lead to confusion and wasted debugging time - log entries end up in
     unexpected places, or are lost altogether.  Or a file that was
     supposed to be moved remains in place, and grows in size
     unexpectedly despite size-based rotation being supposedly in place.

Use the techniques outlined in *note Logging to a single file from
multiple processes: 5750. to circumvent such issues.


File: python.info,  Node: Using loggers as attributes in a class or passing them as parameters,  Next: Adding handlers other than NullHandler to a logger in a library,  Prev: Opening the same log file multiple times,  Up: Patterns to avoid

9.9.37.2 Using loggers as attributes in a class or passing them as parameters
.............................................................................

While there might be unusual cases where you’ll need to do this, in
general there is no point because loggers are singletons.  Code can
always access a given logger instance by name using
‘logging.getLogger(name)’, so passing instances around and holding them
as instance attributes is pointless.  Note that in other languages such
as Java and C#, loggers are often static class attributes.  However,
this pattern doesn’t make sense in Python, where the module (and not the
class) is the unit of software decomposition.


File: python.info,  Node: Adding handlers other than NullHandler to a logger in a library,  Next: Creating a lot of loggers,  Prev: Using loggers as attributes in a class or passing them as parameters,  Up: Patterns to avoid

9.9.37.3 Adding handlers other than ‘NullHandler’ to a logger in a library
..........................................................................

Configuring logging by adding handlers, formatters and filters is the
responsibility of the application developer, not the library developer.
If you are maintaining a library, ensure that you don’t add handlers to
any of your loggers other than a *note NullHandler: 148c. instance.


File: python.info,  Node: Creating a lot of loggers,  Prev: Adding handlers other than NullHandler to a logger in a library,  Up: Patterns to avoid

9.9.37.4 Creating a lot of loggers
..................................

Loggers are singletons that are never freed during a script execution,
and so creating lots of loggers will use up memory which can’t then be
freed.  Rather than create a logger per e.g.  file processed or network
connection made, use the *note existing mechanisms: 3178. for passing
contextual information into your logs and restrict the loggers created
to those describing areas within your application (generally modules,
but occasionally slightly more fine-grained than that).


File: python.info,  Node: Other resources<2>,  Prev: Patterns to avoid,  Up: Logging Cookbook

9.9.38 Other resources
----------------------

Vedi anche
..........

Module *note logging: 8b.

     API reference for the logging module.

Module *note logging.config: 8c.

     Configuration API for the logging module.

Module *note logging.handlers: 8d.

     Useful handlers included with the logging module.

*note Basic Tutorial: 13fd.

*note Advanced Tutorial: 13fe.


File: python.info,  Node: Regular Expression HOWTO,  Next: Socket Programming HOWTO,  Prev: Logging Cookbook,  Up: Python HOWTOs

9.10 Regular Expression HOWTO
=============================


Author: A.M. Kuchling <<amk@amk.ca>>

Abstract
........

This document is an introductory tutorial to using regular expressions
in Python with the *note re: be. module.  It provides a gentler
introduction than the corresponding section in the Library Reference.

* Menu:

* Introduction: Introduction<15>.
* Simple Patterns::
* Using Regular Expressions::
* More Pattern Power::
* Modifying Strings::
* Common Problems::
* Feedback::


File: python.info,  Node: Introduction<15>,  Next: Simple Patterns,  Up: Regular Expression HOWTO

9.10.1 Introduction
-------------------

Regular expressions (called REs, or regexes, or regex patterns) are
essentially a tiny, highly specialized programming language embedded
inside Python and made available through the *note re: be. module.
Using this little language, you specify the rules for the set of
possible strings that you want to match; this set might contain English
sentences, or e-mail addresses, or TeX commands, or anything you like.
You can then ask questions such as «Does this string match the
pattern?», or «Is there a match for the pattern anywhere in this
string?».  You can also use REs to modify a string or to split it apart
in various ways.

Regular expression patterns are compiled into a series of bytecodes
which are then executed by a matching engine written in C. For advanced
use, it may be necessary to pay careful attention to how the engine will
execute a given RE, and write the RE in a certain way in order to
produce bytecode that runs faster.  Optimization isn’t covered in this
document, because it requires that you have a good understanding of the
matching engine’s internals.

The regular expression language is relatively small and restricted, so
not all possible string processing tasks can be done using regular
expressions.  There are also tasks that 'can' be done with regular
expressions, but the expressions turn out to be very complicated.  In
these cases, you may be better off writing Python code to do the
processing; while Python code will be slower than an elaborate regular
expression, it will also probably be more understandable.


File: python.info,  Node: Simple Patterns,  Next: Using Regular Expressions,  Prev: Introduction<15>,  Up: Regular Expression HOWTO

9.10.2 Simple Patterns
----------------------

We’ll start by learning about the simplest possible regular expressions.
Since regular expressions are used to operate on strings, we’ll begin
with the most common task: matching characters.

For a detailed explanation of the computer science underlying regular
expressions (deterministic and non-deterministic finite automata), you
can refer to almost any textbook on writing compilers.

* Menu:

* Matching Characters::
* Repeating Things::


File: python.info,  Node: Matching Characters,  Next: Repeating Things,  Up: Simple Patterns

9.10.2.1 Matching Characters
............................

Most letters and characters will simply match themselves.  For example,
the regular expression ‘test’ will match the string ‘test’ exactly.
(You can enable a case-insensitive mode that would let this RE match
‘Test’ or ‘TEST’ as well; more about this later.)

There are exceptions to this rule; some characters are special
'metacharacters', and don’t match themselves.  Instead, they signal that
some out-of-the-ordinary thing should be matched, or they affect other
portions of the RE by repeating them or changing their meaning.  Much of
this document is devoted to discussing various metacharacters and what
they do.

Here’s a complete list of the metacharacters; their meanings will be
discussed in the rest of this HOWTO.

     . ^ $ * + ? { } [ ] \ | ( )

The first metacharacters we’ll look at are ‘[’ and ‘]’.  They’re used
for specifying a character class, which is a set of characters that you
wish to match.  Characters can be listed individually, or a range of
characters can be indicated by giving two characters and separating them
by a ‘'-'’.  For example, ‘[abc]’ will match any of the characters ‘a’,
‘b’, or ‘c’; this is the same as ‘[a-c]’, which uses a range to express
the same set of characters.  If you wanted to match only lowercase
letters, your RE would be ‘[a-z]’.

Metacharacters (except ‘\’) are not active inside classes.  For example,
‘[akm$]’ will match any of the characters ‘'a'’, ‘'k'’, ‘'m'’, or ‘'$'’;
‘'$'’ is usually a metacharacter, but inside a character class it’s
stripped of its special nature.

You can match the characters not listed within the class by
'complementing' the set.  This is indicated by including a ‘'^'’ as the
first character of the class.  For example, ‘[^5]’ will match any
character except ‘'5'’.  If the caret appears elsewhere in a character
class, it does not have special meaning.  For example: ‘[5^]’ will match
either a ‘'5'’ or a ‘'^'’.

Perhaps the most important metacharacter is the backslash, ‘\’.  As in
Python string literals, the backslash can be followed by various
characters to signal various special sequences.  It’s also used to
escape all the metacharacters so you can still match them in patterns;
for example, if you need to match a ‘[’ or ‘\’, you can precede them
with a backslash to remove their special meaning: ‘\[’ or ‘\\’.

Some of the special sequences beginning with ‘'\'’ represent predefined
sets of characters that are often useful, such as the set of digits, the
set of letters, or the set of anything that isn’t whitespace.

Let’s take an example: ‘\w’ matches any alphanumeric character.  If the
regex pattern is expressed in bytes, this is equivalent to the class
‘[a-zA-Z0-9_]’.  If the regex pattern is a string, ‘\w’ will match all
the characters marked as letters in the Unicode database provided by the
*note unicodedata: 10b. module.  You can use the more restricted
definition of ‘\w’ in a string pattern by supplying the *note re.ASCII:
83f. flag when compiling the regular expression.

The following list of special sequences isn’t complete.  For a complete
list of sequences and expanded class definitions for Unicode string
patterns, see the last part of *note Regular Expression Syntax: 92f. in
the Standard Library reference.  In general, the Unicode versions match
any character that’s in the appropriate category in the Unicode
database.

‘\d’

     Matches any decimal digit; this is equivalent to the class ‘[0-9]’.

‘\D’

     Matches any non-digit character; this is equivalent to the class
     ‘[^0-9]’.

‘\s’

     Matches any whitespace character; this is equivalent to the class
     ‘[ \t\n\r\f\v]’.

‘\S’

     Matches any non-whitespace character; this is equivalent to the
     class ‘[^ \t\n\r\f\v]’.

‘\w’

     Matches any alphanumeric character; this is equivalent to the class
     ‘[a-zA-Z0-9_]’.

‘\W’

     Matches any non-alphanumeric character; this is equivalent to the
     class ‘[^a-zA-Z0-9_]’.

These sequences can be included inside a character class.  For example,
‘[\s,.]’ is a character class that will match any whitespace character,
or ‘','’ or ‘'.'’.

The final metacharacter in this section is ‘.’.  It matches anything
except a newline character, and there’s an alternate mode (*note
re.DOTALL: 2746.) where it will match even a newline.  ‘.’ is often used
where you want to match «any character».


File: python.info,  Node: Repeating Things,  Prev: Matching Characters,  Up: Simple Patterns

9.10.2.2 Repeating Things
.........................

Being able to match varying sets of characters is the first thing
regular expressions can do that isn’t already possible with the methods
available on strings.  However, if that was the only additional
capability of regexes, they wouldn’t be much of an advance.  Another
capability is that you can specify that portions of the RE must be
repeated a certain number of times.

The first metacharacter for repeating things that we’ll look at is ‘*’.
‘*’ doesn’t match the literal character ‘'*'’; instead, it specifies
that the previous character can be matched zero or more times, instead
of exactly once.

For example, ‘ca*t’ will match ‘'ct'’ (0 ‘'a'’ characters), ‘'cat'’ (1
‘'a'’), ‘'caaat'’ (3 ‘'a'’ characters), and so forth.

Repetitions such as ‘*’ are 'greedy'; when repeating a RE, the matching
engine will try to repeat it as many times as possible.  If later
portions of the pattern don’t match, the matching engine will then back
up and try again with fewer repetitions.

A step-by-step example will make this more obvious.  Let’s consider the
expression ‘a[bcd]*b’.  This matches the letter ‘'a'’, zero or more
letters from the class ‘[bcd]’, and finally ends with a ‘'b'’.  Now
imagine matching this RE against the string ‘'abcbd'’.

Step       Matched         Explanation
                           
-----------------------------------------------------------------
                           
1          ‘a’             The ‘a’ in the RE matches.
                           
                           
2          ‘abcbd’         The engine matches ‘[bcd]*’, going
                           as far as it can, which is to the
                           end of the string.
                           
                           
3          'Failure'       The engine tries to match ‘b’, but
                           the current position is at the end
                           of the string, so it fails.
                           
                           
4          ‘abcb’          Back up, so that ‘[bcd]*’ matches
                           one less character.
                           
                           
5          'Failure'       Try ‘b’ again, but the current
                           position is at the last character,
                           which is a ‘'d'’.
                           
                           
6          ‘abc’           Back up again, so that ‘[bcd]*’ is
                           only matching ‘bc’.
                           
                           
6          ‘abcb’          Try ‘b’ again.  This time the
                           character at the current position
                           is ‘'b'’, so it succeeds.
                           

The end of the RE has now been reached, and it has matched ‘'abcb'’.
This demonstrates how the matching engine goes as far as it can at
first, and if no match is found it will then progressively back up and
retry the rest of the RE again and again.  It will back up until it has
tried zero matches for ‘[bcd]*’, and if that subsequently fails, the
engine will conclude that the string doesn’t match the RE at all.

Another repeating metacharacter is ‘+’, which matches one or more times.
Pay careful attention to the difference between ‘*’ and ‘+’; ‘*’ matches
'zero' or more times, so whatever’s being repeated may not be present at
all, while ‘+’ requires at least 'one' occurrence.  To use a similar
example, ‘ca+t’ will match ‘'cat'’ (1 ‘'a'’), ‘'caaat'’ (3 ‘'a'’s), but
won’t match ‘'ct'’.

There are two more repeating operators or quantifiers.  The question
mark character, ‘?’, matches either once or zero times; you can think of
it as marking something as being optional.  For example, ‘home-?brew’
matches either ‘'homebrew'’ or ‘'home-brew'’.

The most complicated quantifier is ‘{m,n}’, where 'm' and 'n' are
decimal integers.  This quantifier means there must be at least 'm'
repetitions, and at most 'n'.  For example, ‘a/{1,3}b’ will match
‘'a/b'’, ‘'a//b'’, and ‘'a///b'’.  It won’t match ‘'ab'’, which has no
slashes, or ‘'a////b'’, which has four.

You can omit either 'm' or 'n'; in that case, a reasonable value is
assumed for the missing value.  Omitting 'm' is interpreted as a lower
limit of 0, while omitting 'n' results in an upper bound of infinity.

The simplest case ‘{m}’ matches the preceding item exactly 'm' times.
For example, ‘a/{2}b’ will only match ‘'a//b'’.

Readers of a reductionist bent may notice that the three other
quantifiers can all be expressed using this notation.  ‘{0,}’ is the
same as ‘*’, ‘{1,}’ is equivalent to ‘+’, and ‘{0,1}’ is the same as
‘?’.  It’s better to use ‘*’, ‘+’, or ‘?’ when you can, simply because
they’re shorter and easier to read.


File: python.info,  Node: Using Regular Expressions,  Next: More Pattern Power,  Prev: Simple Patterns,  Up: Regular Expression HOWTO

9.10.3 Using Regular Expressions
--------------------------------

Now that we’ve looked at some simple regular expressions, how do we
actually use them in Python?  The *note re: be. module provides an
interface to the regular expression engine, allowing you to compile REs
into objects and then perform matches with them.

* Menu:

* Compiling Regular Expressions::
* The Backslash Plague::
* Performing Matches::
* Module-Level Functions: Module-Level Functions<3>.
* Compilation Flags::


File: python.info,  Node: Compiling Regular Expressions,  Next: The Backslash Plague,  Up: Using Regular Expressions

9.10.3.1 Compiling Regular Expressions
......................................

Regular expressions are compiled into pattern objects, which have
methods for various operations such as searching for pattern matches or
performing string substitutions.

     >>> import re
     >>> p = re.compile('ab*')
     >>> p
     re.compile('ab*')

*note re.compile(): dd0. also accepts an optional 'flags' argument, used
to enable various special features and syntax variations.  We’ll go over
the available settings later, but for now a single example will do:

     >>> p = re.compile('ab*', re.IGNORECASE)

The RE is passed to *note re.compile(): dd0. as a string.  REs are
handled as strings because regular expressions aren’t part of the core
Python language, and no special syntax was created for expressing them.
(There are applications that don’t need REs at all, so there’s no need
to bloat the language specification by including them.)  Instead, the
*note re: be. module is simply a C extension module included with
Python, just like the *note socket: d1. or *note zlib: 139. modules.

Putting REs in strings keeps the Python language simpler, but has one
disadvantage which is the topic of the next section.


File: python.info,  Node: The Backslash Plague,  Next: Performing Matches,  Prev: Compiling Regular Expressions,  Up: Using Regular Expressions

9.10.3.2 The Backslash Plague
.............................

As stated earlier, regular expressions use the backslash character
(‘'\'’) to indicate special forms or to allow special characters to be
used without invoking their special meaning.  This conflicts with
Python’s usage of the same character for the same purpose in string
literals.

Let’s say you want to write a RE that matches the string ‘\section’,
which might be found in a LaTeX file.  To figure out what to write in
the program code, start with the desired string to be matched.  Next,
you must escape any backslashes and other metacharacters by preceding
them with a backslash, resulting in the string ‘\\section’.  The
resulting string that must be passed to *note re.compile(): dd0. must be
‘\\section’.  However, to express this as a Python string literal, both
backslashes must be escaped 'again'.

Characters              Stage
                        
-----------------------------------------------------------------------
                        
‘\section’              Text string to be matched
                        
                        
‘\\section’             Escaped backslash for
                        *note re.compile(): dd0.
                        
                        
‘"\\\\section"’         Escaped backslashes for a string literal
                        

In short, to match a literal backslash, one has to write ‘'\\\\'’ as the
RE string, because the regular expression must be ‘\\’, and each
backslash must be expressed as ‘\\’ inside a regular Python string
literal.  In REs that feature backslashes repeatedly, this leads to lots
of repeated backslashes and makes the resulting strings difficult to
understand.

The solution is to use Python’s raw string notation for regular
expressions; backslashes are not handled in any special way in a string
literal prefixed with ‘'r'’, so ‘r"\n"’ is a two-character string
containing ‘'\'’ and ‘'n'’, while ‘"\n"’ is a one-character string
containing a newline.  Regular expressions will often be written in
Python code using this raw string notation.

In addition, special escape sequences that are valid in regular
expressions, but not valid as Python string literals, now result in a
*note DeprecationWarning: 1a3. and will eventually become a *note
SyntaxError: 18e, which means the sequences will be invalid if raw
string notation or escaping the backslashes isn’t used.

Regular String          Raw string
                        
-----------------------------------------------
                        
‘"ab*"’                 ‘r"ab*"’
                        
                        
‘"\\\\section"’         ‘r"\\section"’
                        
                        
‘"\\w+\\s+\\1"’         ‘r"\w+\s+\1"’
                        


File: python.info,  Node: Performing Matches,  Next: Module-Level Functions<3>,  Prev: The Backslash Plague,  Up: Using Regular Expressions

9.10.3.3 Performing Matches
...........................

Once you have an object representing a compiled regular expression, what
do you do with it?  Pattern objects have several methods and attributes.
Only the most significant ones will be covered here; consult the *note
re: be. docs for a complete listing.

Method/Attribute       Purpose
                       
---------------------------------------------------------------------------
                       
‘match()’              Determine if the RE matches at the beginning of
                       the string.
                       
                       
‘search()’             Scan through a string, looking for any location
                       where this RE matches.
                       
                       
‘findall()’            Find all substrings where the RE matches, and
                       returns them as a list.
                       
                       
‘finditer()’           Find all substrings where the RE matches, and
                       returns them as an *note iterator: 4c9.
                       

*note match(): 2757. and *note search(): 2758. return ‘None’ if no match
can be found.  If they’re successful, a *note match object: 118a.
instance is returned, containing information about the match: where it
starts and ends, the substring it matched, and more.

You can learn about this by interactively experimenting with the *note
re: be. module.

This HOWTO uses the standard Python interpreter for its examples.
First, run the Python interpreter, import the *note re: be. module, and
compile a RE:

     >>> import re
     >>> p = re.compile('[a-z]+')
     >>> p
     re.compile('[a-z]+')

Now, you can try matching various strings against the RE ‘[a-z]+’.  An
empty string shouldn’t match at all, since ‘+’ means “one or more
repetitions”.  *note match(): 2757. should return ‘None’ in this case,
which will cause the interpreter to print no output.  You can explicitly
print the result of ‘match()’ to make this clear.

     >>> p.match("")
     >>> print(p.match(""))
     None

Now, let’s try it on a string that it should match, such as ‘tempo’.  In
this case, *note match(): 2757. will return a *note match object: 118a,
so you should store the result in a variable for later use.

     >>> m = p.match('tempo')
     >>> m
     <re.Match object; span=(0, 5), match='tempo'>

Now you can query the *note match object: 118a. for information about
the matching string.  Match object instances also have several methods
and attributes; the most important ones are:

Method/Attribute       Purpose
                       
------------------------------------------------------------------------
                       
‘group()’              Return the string matched by the RE
                       
                       
‘start()’              Return the starting position of the match
                       
                       
‘end()’                Return the ending position of the match
                       
                       
‘span()’               Return a tuple containing the (start, end)
                       positions of the match
                       

Trying these methods will soon clarify their meaning:

     >>> m.group()
     'tempo'
     >>> m.start(), m.end()
     (0, 5)
     >>> m.span()
     (0, 5)

*note group(): 122d. returns the substring that was matched by the RE.
*note start(): 276a. and *note end(): 276b. return the starting and
ending index of the match.  *note span(): 276c. returns both start and
end indexes in a single tuple.  Since the *note match(): 2757. method
only checks if the RE matches at the start of a string, ‘start()’ will
always be zero.  However, the *note search(): 2758. method of patterns
scans through the string, so the match may not start at zero in that
case.

     >>> print(p.match('::: message'))
     None
     >>> m = p.search('::: message'); print(m)
     <re.Match object; span=(4, 11), match='message'>
     >>> m.group()
     'message'
     >>> m.span()
     (4, 11)

In actual programs, the most common style is to store the *note match
object: 118a. in a variable, and then check if it was ‘None’.  This
usually looks like:

     p = re.compile( ... )
     m = p.match( 'string goes here' )
     if m:
         print('Match found: ', m.group())
     else:
         print('No match')

Two pattern methods return all of the matches for a pattern.  *note
findall(): 275e. returns a list of matching strings:

     >>> p = re.compile(r'\d+')
     >>> p.findall('12 drummers drumming, 11 pipers piping, 10 lords a-leaping')
     ['12', '11', '10']

The ‘r’ prefix, making the literal a raw string literal, is needed in
this example because escape sequences in a normal «cooked» string
literal that are not recognized by Python, as opposed to regular
expressions, now result in a *note DeprecationWarning: 1a3. and will
eventually become a *note SyntaxError: 18e.  See *note The Backslash
Plague: 578f.

*note findall(): 275e. has to create the entire list before it can be
returned as the result.  The *note finditer(): 275f. method returns a
sequence of *note match object: 118a. instances as an *note iterator:
4c9.:

     >>> iterator = p.finditer('12 drummers drumming, 11 ... 10 ...')
     >>> iterator
     <callable_iterator object at 0x...>
     >>> for match in iterator:
     ...     print(match.span())
     ...
     (0, 2)
     (22, 24)
     (29, 31)


File: python.info,  Node: Module-Level Functions<3>,  Next: Compilation Flags,  Prev: Performing Matches,  Up: Using Regular Expressions

9.10.3.4 Module-Level Functions
...............................

You don’t have to create a pattern object and call its methods; the
*note re: be. module also provides top-level functions called *note
match(): 1435, *note search(): 1434, *note findall(): 122c, *note sub():
5a3, and so forth.  These functions take the same arguments as the
corresponding pattern method with the RE string added as the first
argument, and still return either ‘None’ or a *note match object: 118a.
instance.

     >>> print(re.match(r'From\s+', 'Fromage amk'))
     None
     >>> re.match(r'From\s+', 'From amk Thu May 14 19:12:10 1998')
     <re.Match object; span=(0, 5), match='From '>

Under the hood, these functions simply create a pattern object for you
and call the appropriate method on it.  They also store the compiled
object in a cache, so future calls using the same RE won’t need to parse
the pattern again and again.

Should you use these module-level functions, or should you get the
pattern and call its methods yourself?  If you’re accessing a regex
within a loop, pre-compiling it will save a few function calls.  Outside
of loops, there’s not much difference thanks to the internal cache.


File: python.info,  Node: Compilation Flags,  Prev: Module-Level Functions<3>,  Up: Using Regular Expressions

9.10.3.5 Compilation Flags
..........................

Compilation flags let you modify some aspects of how regular expressions
work.  Flags are available in the *note re: be. module under two names,
a long name such as *note IGNORECASE: 1a7e. and a short, one-letter form
such as *note I: 2749.  (If you’re familiar with Perl’s pattern
modifiers, the one-letter forms use the same letters; the short form of
*note re.VERBOSE: 2755. is *note re.X: 274e, for example.)  Multiple
flags can be specified by bitwise OR-ing them; ‘re.I | re.M’ sets both
the *note I: 2749. and *note M: 274b. flags, for example.

Here’s a table of the available flags, followed by a more detailed
explanation of each one.

Flag                                  Meaning
                                      
---------------------------------------------------------------------------------------
                                      
*note ASCII: 83f, *note A: 2748.      Makes several escapes like ‘\w’, ‘\b’, ‘\s’
                                      and ‘\d’ match only on ASCII characters with
                                      the respective property.
                                      
                                      
*note DOTALL: 2746, *note S: 274c.    Make ‘.’ match any character, including
                                      newlines.
                                      
                                      
*note IGNORECASE: 1a7e,               Do case-insensitive matches.
*note I: 2749.                        

*note LOCALE: d65, *note L: 274a.     Do a locale-aware match.
                                      
                                      
*note MULTILINE: 2747,                Multi-line matching, affecting ‘^’ and ‘$’.
*note M: 274b.                        

*note VERBOSE: 2755, *note X: 274e.   Enable verbose REs, which can be organized
(for “extended”)                      more cleanly and understandably.
                                      

 -- Dati: re.I

 -- Dati: re.IGNORECASE

     Perform case-insensitive matching; character class and literal
     strings will match letters by ignoring case.  For example, ‘[A-Z]’
     will match lowercase letters, too.  Full Unicode matching also
     works unless the *note ASCII: 83f. flag is used to disable
     non-ASCII matches.  When the Unicode patterns ‘[a-z]’ or ‘[A-Z]’
     are used in combination with the *note IGNORECASE: 1a7e. flag, they
     will match the 52 ASCII letters and 4 additional non-ASCII letters:
     “İ” (U+0130, Latin capital letter I with dot above), “ı” (U+0131,
     Latin small letter dotless i), “ſ” (U+017F, Latin small letter long
     s) and “K” (U+212A, Kelvin sign).  ‘Spam’ will match ‘'Spam'’,
     ‘'spam'’, ‘'spAM'’, or ‘'ſpam'’ (the latter is matched only in
     Unicode mode).  This lowercasing doesn’t take the current locale
     into account; it will if you also set the *note LOCALE: d65. flag.

 -- Dati: re.L

 -- Dati: re.LOCALE

     Make ‘\w’, ‘\W’, ‘\b’, ‘\B’ and case-insensitive matching dependent
     on the current locale instead of the Unicode database.

     Locales are a feature of the C library intended to help in writing
     programs that take account of language differences.  For example,
     if you’re processing encoded French text, you’d want to be able to
     write ‘\w+’ to match words, but ‘\w’ only matches the character
     class ‘[A-Za-z]’ in bytes patterns; it won’t match bytes
     corresponding to ‘é’ or ‘ç’.  If your system is configured properly
     and a French locale is selected, certain C functions will tell the
     program that the byte corresponding to ‘é’ should also be
     considered a letter.  Setting the *note LOCALE: d65. flag when
     compiling a regular expression will cause the resulting compiled
     object to use these C functions for ‘\w’; this is slower, but also
     enables ‘\w+’ to match French words as you’d expect.  The use of
     this flag is discouraged in Python 3 as the locale mechanism is
     very unreliable, it only handles one «culture» at a time, and it
     only works with 8-bit locales.  Unicode matching is already enabled
     by default in Python 3 for Unicode (str) patterns, and it is able
     to handle different locales/languages.

 -- Dati: re.M

 -- Dati: re.MULTILINE

     (‘^’ and ‘$’ haven’t been explained yet; they’ll be introduced in
     section *note More Metacharacters: 5793.)

     Usually ‘^’ matches only at the beginning of the string, and ‘$’
     matches only at the end of the string and immediately before the
     newline (if any) at the end of the string.  When this flag is
     specified, ‘^’ matches at the beginning of the string and at the
     beginning of each line within the string, immediately following
     each newline.  Similarly, the ‘$’ metacharacter matches either at
     the end of the string and at the end of each line (immediately
     preceding each newline).

 -- Dati: re.S

 -- Dati: re.DOTALL

     Makes the ‘'.'’ special character match any character at all,
     including a newline; without this flag, ‘'.'’ will match anything
     'except' a newline.

 -- Dati: re.A

 -- Dati: re.ASCII

     Make ‘\w’, ‘\W’, ‘\b’, ‘\B’, ‘\s’ and ‘\S’ perform ASCII-only
     matching instead of full Unicode matching.  This is only meaningful
     for Unicode patterns, and is ignored for byte patterns.

 -- Dati: re.X

 -- Dati: re.VERBOSE

     This flag allows you to write regular expressions that are more
     readable by granting you more flexibility in how you can format
     them.  When this flag has been specified, whitespace within the RE
     string is ignored, except when the whitespace is in a character
     class or preceded by an unescaped backslash; this lets you organize
     and indent the RE more clearly.  This flag also lets you put
     comments within a RE that will be ignored by the engine; comments
     are marked by a ‘'#'’ that’s neither in a character class or
     preceded by an unescaped backslash.

     For example, here’s a RE that uses *note re.VERBOSE: 2755.; see how
     much easier it is to read?

          charref = re.compile(r"""
           &[#]                # Start of a numeric entity reference
           (
               0[0-7]+         # Octal form
             | [0-9]+          # Decimal form
             | x[0-9a-fA-F]+   # Hexadecimal form
           )
           ;                   # Trailing semicolon
          """, re.VERBOSE)

     Without the verbose setting, the RE would look like this:

          charref = re.compile("&#(0[0-7]+"
                               "|[0-9]+"
                               "|x[0-9a-fA-F]+);")

     In the above example, Python’s automatic concatenation of string
     literals has been used to break up the RE into smaller pieces, but
     it’s still more difficult to understand than the version using
     *note re.VERBOSE: 2755.


File: python.info,  Node: More Pattern Power,  Next: Modifying Strings,  Prev: Using Regular Expressions,  Up: Regular Expression HOWTO

9.10.4 More Pattern Power
-------------------------

So far we’ve only covered a part of the features of regular expressions.
In this section, we’ll cover some new metacharacters, and how to use
groups to retrieve portions of the text that was matched.

* Menu:

* More Metacharacters::
* Grouping::
* Non-capturing and Named Groups::
* Lookahead Assertions::


File: python.info,  Node: More Metacharacters,  Next: Grouping,  Up: More Pattern Power

9.10.4.1 More Metacharacters
............................

There are some metacharacters that we haven’t covered yet.  Most of them
will be covered in this section.

Some of the remaining metacharacters to be discussed are 'zero-width
assertions'.  They don’t cause the engine to advance through the string;
instead, they consume no characters at all, and simply succeed or fail.
For example, ‘\b’ is an assertion that the current position is located
at a word boundary; the position isn’t changed by the ‘\b’ at all.  This
means that zero-width assertions should never be repeated, because if
they match once at a given location, they can obviously be matched an
infinite number of times.

‘|’

     Alternation, or the «or» operator.  If 'A' and 'B' are regular
     expressions, ‘A|B’ will match any string that matches either 'A' or
     'B'. ‘|’ has very low precedence in order to make it work
     reasonably when you’re alternating multi-character strings.
     ‘Crow|Servo’ will match either ‘'Crow'’ or ‘'Servo'’, not ‘'Cro'’,
     a ‘'w'’ or an ‘'S'’, and ‘'ervo'’.

     To match a literal ‘'|'’, use ‘\|’, or enclose it inside a
     character class, as in ‘[|]’.

‘^’

     Matches at the beginning of lines.  Unless the *note MULTILINE:
     2747. flag has been set, this will only match at the beginning of
     the string.  In *note MULTILINE: 2747. mode, this also matches
     immediately after each newline within the string.

     For example, if you wish to match the word ‘From’ only at the
     beginning of a line, the RE to use is ‘^From’.

          >>> print(re.search('^From', 'From Here to Eternity'))
          <re.Match object; span=(0, 4), match='From'>
          >>> print(re.search('^From', 'Reciting From Memory'))
          None

     To match a literal ‘'^'’, use ‘\^’.

‘$’

     Matches at the end of a line, which is defined as either the end of
     the string, or any location followed by a newline character.

          >>> print(re.search('}$', '{block}'))
          <re.Match object; span=(6, 7), match='}'>
          >>> print(re.search('}$', '{block} '))
          None
          >>> print(re.search('}$', '{block}\n'))
          <re.Match object; span=(6, 7), match='}'>

     To match a literal ‘'$'’, use ‘\$’ or enclose it inside a character
     class, as in ‘[$]’.

‘\A’

     Matches only at the start of the string.  When not in *note
     MULTILINE: 2747. mode, ‘\A’ and ‘^’ are effectively the same.  In
     *note MULTILINE: 2747. mode, they’re different: ‘\A’ still matches
     only at the beginning of the string, but ‘^’ may match at any
     location inside the string that follows a newline character.

‘\z’

     Matches only at the end of the string.

‘\Z’

     The same as ‘\z’.  For compatibility with old Python versions.

‘\b’

     Word boundary.  This is a zero-width assertion that matches only at
     the beginning or end of a word.  A word is defined as a sequence of
     alphanumeric characters, so the end of a word is indicated by
     whitespace or a non-alphanumeric character.

     The following example matches ‘class’ only when it’s a complete
     word; it won’t match when it’s contained inside another word.

          >>> p = re.compile(r'\bclass\b')
          >>> print(p.search('no class at all'))
          <re.Match object; span=(3, 8), match='class'>
          >>> print(p.search('the declassified algorithm'))
          None
          >>> print(p.search('one subclass is'))
          None

     There are two subtleties you should remember when using this
     special sequence.  First, this is the worst collision between
     Python’s string literals and regular expression sequences.  In
     Python’s string literals, ‘\b’ is the backspace character, ASCII
     value 8.  If you’re not using raw strings, then Python will convert
     the ‘\b’ to a backspace, and your RE won’t match as you expect it
     to.  The following example looks the same as our previous RE, but
     omits the ‘'r'’ in front of the RE string.

          >>> p = re.compile('\bclass\b')
          >>> print(p.search('no class at all'))
          None
          >>> print(p.search('\b' + 'class' + '\b'))
          <re.Match object; span=(0, 7), match='\x08class\x08'>

     Second, inside a character class, where there’s no use for this
     assertion, ‘\b’ represents the backspace character, for
     compatibility with Python’s string literals.

‘\B’

     Another zero-width assertion, this is the opposite of ‘\b’, only
     matching when the current position is not at a word boundary.


File: python.info,  Node: Grouping,  Next: Non-capturing and Named Groups,  Prev: More Metacharacters,  Up: More Pattern Power

9.10.4.2 Grouping
.................

Frequently you need to obtain more information than just whether the RE
matched or not.  Regular expressions are often used to dissect strings
by writing a RE divided into several subgroups which match different
components of interest.  For example, an RFC-822 header line is divided
into a header name and a value, separated by a ‘':'’, like this:

     From: author@example.com
     User-Agent: Thunderbird 1.5.0.9 (X11/20061227)
     MIME-Version: 1.0
     To: editor@example.com

This can be handled by writing a regular expression which matches an
entire header line, and has one group which matches the header name, and
another group which matches the header’s value.

Groups are marked by the ‘'('’, ‘')'’ metacharacters.  ‘'('’ and ‘')'’
have much the same meaning as they do in mathematical expressions; they
group together the expressions contained inside them, and you can repeat
the contents of a group with a quantifier, such as ‘*’, ‘+’, ‘?’, or
‘{m,n}’.  For example, ‘(ab)*’ will match zero or more repetitions of
‘ab’.

     >>> p = re.compile('(ab)*')
     >>> print(p.match('ababababab').span())
     (0, 10)

Groups indicated with ‘'('’, ‘')'’ also capture the starting and ending
index of the text that they match; this can be retrieved by passing an
argument to *note group(): 122d, *note start(): 276a, *note end(): 276b,
and *note span(): 276c.  Groups are numbered starting with 0.  Group 0
is always present; it’s the whole RE, so *note match object: 118a.
methods all have group 0 as their default argument.  Later we’ll see how
to express groups that don’t capture the span of text that they match.

     >>> p = re.compile('(a)b')
     >>> m = p.match('ab')
     >>> m.group()
     'ab'
     >>> m.group(0)
     'ab'

Subgroups are numbered from left to right, from 1 upward.  Groups can be
nested; to determine the number, just count the opening parenthesis
characters, going from left to right.

     >>> p = re.compile('(a(b)c)d')
     >>> m = p.match('abcd')
     >>> m.group(0)
     'abcd'
     >>> m.group(1)
     'abc'
     >>> m.group(2)
     'b'

*note group(): 122d. can be passed multiple group numbers at a time, in
which case it will return a tuple containing the corresponding values
for those groups.

     >>> m.group(2,1,2)
     ('b', 'abc', 'b')

The *note groups(): 122e. method returns a tuple containing the strings
for all the subgroups, from 1 up to however many there are.

     >>> m.groups()
     ('abc', 'b')

Backreferences in a pattern allow you to specify that the contents of an
earlier capturing group must also be found at the current location in
the string.  For example, ‘\1’ will succeed if the exact contents of
group 1 can be found at the current position, and fails otherwise.
Remember that Python’s string literals also use a backslash followed by
numbers to allow including arbitrary characters in a string, so be sure
to use a raw string when incorporating backreferences in a RE.

For example, the following RE detects doubled words in a string.

     >>> p = re.compile(r'\b(\w+)\s+\1\b')
     >>> p.search('Paris in the the spring').group()
     'the the'

Backreferences like this aren’t often useful for just searching through
a string — there are few text formats which repeat data in this way —
but you’ll soon find out that they’re 'very' useful when performing
string substitutions.


File: python.info,  Node: Non-capturing and Named Groups,  Next: Lookahead Assertions,  Prev: Grouping,  Up: More Pattern Power

9.10.4.3 Non-capturing and Named Groups
.......................................

Elaborate REs may use many groups, both to capture substrings of
interest, and to group and structure the RE itself.  In complex REs, it
becomes difficult to keep track of the group numbers.  There are two
features which help with this problem.  Both of them use a common syntax
for regular expression extensions, so we’ll look at that first.

Perl 5 is well known for its powerful additions to standard regular
expressions.  For these new features the Perl developers couldn’t choose
new single-keystroke metacharacters or new special sequences beginning
with ‘\’ without making Perl’s regular expressions confusingly different
from standard REs.  If they chose ‘&’ as a new metacharacter, for
example, old expressions would be assuming that ‘&’ was a regular
character and wouldn’t have escaped it by writing ‘\&’ or ‘[&]’.

The solution chosen by the Perl developers was to use ‘(?...)’ as the
extension syntax.  ‘?’ immediately after a parenthesis was a syntax
error because the ‘?’ would have nothing to repeat, so this didn’t
introduce any compatibility problems.  The characters immediately after
the ‘?’ indicate what extension is being used, so ‘(?=foo)’ is one thing
(a positive lookahead assertion) and ‘(?:foo)’ is something else (a
non-capturing group containing the subexpression ‘foo’).

Python supports several of Perl’s extensions and adds an extension
syntax to Perl’s extension syntax.  If the first character after the
question mark is a ‘P’, you know that it’s an extension that’s specific
to Python.

Now that we’ve looked at the general extension syntax, we can return to
the features that simplify working with groups in complex REs.

Sometimes you’ll want to use a group to denote a part of a regular
expression, but aren’t interested in retrieving the group’s contents.
You can make this fact explicit by using a non-capturing group:
‘(?:...)’, where you can replace the ‘...’ with any other regular
expression.

     >>> m = re.match("([abc])+", "abc")
     >>> m.groups()
     ('c',)
     >>> m = re.match("(?:[abc])+", "abc")
     >>> m.groups()
     ()

Except for the fact that you can’t retrieve the contents of what the
group matched, a non-capturing group behaves exactly the same as a
capturing group; you can put anything inside it, repeat it with a
repetition metacharacter such as ‘*’, and nest it within other groups
(capturing or non-capturing).  ‘(?:...)’ is particularly useful when
modifying an existing pattern, since you can add new groups without
changing how all the other groups are numbered.  It should be mentioned
that there’s no performance difference in searching between capturing
and non-capturing groups; neither form is any faster than the other.

A more significant feature is named groups: instead of referring to them
by numbers, groups can be referenced by a name.

The syntax for a named group is one of the Python-specific extensions:
‘(?P<name>...)’.  'name' is, obviously, the name of the group.  Named
groups behave exactly like capturing groups, and additionally associate
a name with a group.  The *note match object: 118a. methods that deal
with capturing groups all accept either integers that refer to the group
by number or strings that contain the desired group’s name.  Named
groups are still given numbers, so you can retrieve information about a
group in two ways:

     >>> p = re.compile(r'(?P<word>\b\w+\b)')
     >>> m = p.search( '(((( Lots of punctuation )))' )
     >>> m.group('word')
     'Lots'
     >>> m.group(1)
     'Lots'

Additionally, you can retrieve named groups as a dictionary with *note
groupdict(): 2769.:

     >>> m = re.match(r'(?P<first>\w+) (?P<last>\w+)', 'Jane Doe')
     >>> m.groupdict()
     {'first': 'Jane', 'last': 'Doe'}

Named groups are handy because they let you use easily remembered names,
instead of having to remember numbers.  Here’s an example RE from the
*note imaplib: 78. module:

     InternalDate = re.compile(r'INTERNALDATE "'
             r'(?P<day>[ 123][0-9])-(?P<mon>[A-Z][a-z][a-z])-'
             r'(?P<year>[0-9][0-9][0-9][0-9])'
             r' (?P<hour>[0-9][0-9]):(?P<min>[0-9][0-9]):(?P<sec>[0-9][0-9])'
             r' (?P<zonen>[-+])(?P<zoneh>[0-9][0-9])(?P<zonem>[0-9][0-9])'
             r'"')

It’s obviously much easier to retrieve ‘m.group('zonem')’, instead of
having to remember to retrieve group 9.

The syntax for backreferences in an expression such as ‘(...)\1’ refers
to the number of the group.  There’s naturally a variant that uses the
group name instead of the number.  This is another Python extension:
‘(?P=name)’ indicates that the contents of the group called 'name'
should again be matched at the current point.  The regular expression
for finding doubled words, ‘\b(\w+)\s+\1\b’ can also be written as
‘\b(?P<word>\w+)\s+(?P=word)\b’:

     >>> p = re.compile(r'\b(?P<word>\w+)\s+(?P=word)\b')
     >>> p.search('Paris in the the spring').group()
     'the the'


File: python.info,  Node: Lookahead Assertions,  Prev: Non-capturing and Named Groups,  Up: More Pattern Power

9.10.4.4 Lookahead Assertions
.............................

Another zero-width assertion is the lookahead assertion.  Lookahead
assertions are available in both positive and negative form, and look
like this:

‘(?=...)’

     Positive lookahead assertion.  This succeeds if the contained
     regular expression, represented here by ‘...’, successfully matches
     at the current location, and fails otherwise.  But, once the
     contained expression has been tried, the matching engine doesn’t
     advance at all; the rest of the pattern is tried right where the
     assertion started.

‘(?!...)’

     Negative lookahead assertion.  This is the opposite of the positive
     assertion; it succeeds if the contained expression 'doesn’t' match
     at the current position in the string.

To make this concrete, let’s look at a case where a lookahead is useful.
Consider a simple pattern to match a filename and split it apart into a
base name and an extension, separated by a ‘.’.  For example, in
‘news.rc’, ‘news’ is the base name, and ‘rc’ is the filename’s
extension.

The pattern to match this is quite simple:

‘.*[.].*$’

Notice that the ‘.’ needs to be treated specially because it’s a
metacharacter, so it’s inside a character class to only match that
specific character.  Also notice the trailing ‘$’; this is added to
ensure that all the rest of the string must be included in the
extension.  This regular expression matches ‘foo.bar’ and ‘autoexec.bat’
and ‘sendmail.cf’ and ‘printers.conf’.

Now, consider complicating the problem a bit; what if you want to match
filenames where the extension is not ‘bat’?  Some incorrect attempts:

‘.*[.][^b].*$’

The first attempt above tries to exclude ‘bat’ by requiring that the
first character of the extension is not a ‘b’.  This is wrong, because
the pattern also doesn’t match ‘foo.bar’.

‘.*[.]([^b]..|.[^a].|..[^t])$’

The expression gets messier when you try to patch up the first solution
by requiring one of the following cases to match: the first character of
the extension isn’t ‘b’; the second character isn’t ‘a’; or the third
character isn’t ‘t’.  This accepts ‘foo.bar’ and rejects ‘autoexec.bat’,
but it requires a three-letter extension and won’t accept a filename
with a two-letter extension such as ‘sendmail.cf’.  We’ll complicate the
pattern again in an effort to fix it.

‘.*[.]([^b].?.?|.[^a]?.?|..?[^t]?)$’

In the third attempt, the second and third letters are all made optional
in order to allow matching extensions shorter than three characters,
such as ‘sendmail.cf’.

The pattern’s getting really complicated now, which makes it hard to
read and understand.  Worse, if the problem changes and you want to
exclude both ‘bat’ and ‘exe’ as extensions, the pattern would get even
more complicated and confusing.

A negative lookahead cuts through all this confusion:

‘.*[.](?!bat$)[^.]*$’

The negative lookahead means: if the expression ‘bat’ doesn’t match at
this point, try the rest of the pattern; if ‘bat$’ does match, the whole
pattern will fail.  The trailing ‘$’ is required to ensure that
something like ‘sample.batch’, where the extension only starts with
‘bat’, will be allowed.  The ‘[^.]*’ makes sure that the pattern works
when there are multiple dots in the filename.

Excluding another filename extension is now easy; simply add it as an
alternative inside the assertion.  The following pattern excludes
filenames that end in either ‘bat’ or ‘exe’:

‘.*[.](?!bat$|exe$)[^.]*$’


File: python.info,  Node: Modifying Strings,  Next: Common Problems,  Prev: More Pattern Power,  Up: Regular Expression HOWTO

9.10.5 Modifying Strings
------------------------

Up to this point, we’ve simply performed searches against a static
string.  Regular expressions are also commonly used to modify strings in
various ways, using the following pattern methods:

Method/Attribute       Purpose
                       
---------------------------------------------------------------------------
                       
‘split()’              Split the string into a list, splitting it
                       wherever the RE matches
                       
                       
‘sub()’                Find all substrings where the RE matches, and
                       replace them with a different string
                       
                       
‘subn()’               Does the same thing as ‘sub()’, but returns the
                       new string and the number of replacements
                       

* Menu:

* Splitting Strings::
* Search and Replace: Search and Replace<2>.


File: python.info,  Node: Splitting Strings,  Next: Search and Replace<2>,  Up: Modifying Strings

9.10.5.1 Splitting Strings
..........................

The *note split(): 275d. method of a pattern splits a string apart
wherever the RE matches, returning a list of the pieces.  It’s similar
to the *note split(): 10ac. method of strings but provides much more
generality in the delimiters that you can split by; string ‘split()’
only supports splitting by whitespace or by a fixed string.  As you’d
expect, there’s a module-level *note re.split(): 5a2. function, too.

 -- Metodo: .split (string[, maxsplit=0])

     Split 'string' by the matches of the regular expression.  If
     capturing parentheses are used in the RE, then their contents will
     also be returned as part of the resulting list.  If 'maxsplit' is
     nonzero, at most 'maxsplit' splits are performed.

You can limit the number of splits made, by passing a value for
'maxsplit'.  When 'maxsplit' is nonzero, at most 'maxsplit' splits will
be made, and the remainder of the string is returned as the final
element of the list.  In the following example, the delimiter is any
sequence of non-alphanumeric characters.

     >>> p = re.compile(r'\W+')
     >>> p.split('This is a test, short and sweet, of split().')
     ['This', 'is', 'a', 'test', 'short', 'and', 'sweet', 'of', 'split', '']
     >>> p.split('This is a test, short and sweet, of split().', 3)
     ['This', 'is', 'a', 'test, short and sweet, of split().']

Sometimes you’re not only interested in what the text between delimiters
is, but also need to know what the delimiter was.  If capturing
parentheses are used in the RE, then their values are also returned as
part of the list.  Compare the following calls:

     >>> p = re.compile(r'\W+')
     >>> p2 = re.compile(r'(\W+)')
     >>> p.split('This... is a test.')
     ['This', 'is', 'a', 'test', '']
     >>> p2.split('This... is a test.')
     ['This', '... ', 'is', ' ', 'a', ' ', 'test', '.', '']

The module-level function *note re.split(): 5a2. adds the RE to be used
as the first argument, but is otherwise the same.

     >>> re.split(r'[\W]+', 'Words, words, words.')
     ['Words', 'words', 'words', '']
     >>> re.split(r'([\W]+)', 'Words, words, words.')
     ['Words', ', ', 'words', ', ', 'words', '.', '']
     >>> re.split(r'[\W]+', 'Words, words, words.', 1)
     ['Words', 'words, words.']


File: python.info,  Node: Search and Replace<2>,  Prev: Splitting Strings,  Up: Modifying Strings

9.10.5.2 Search and Replace
...........................

Another common task is to find all the matches for a pattern, and
replace them with a different string.  The *note sub(): 2760. method
takes a replacement value, which can be either a string or a function,
and the string to be processed.

 -- Metodo: .sub (replacement, string[, count=0])

     Returns the string obtained by replacing the leftmost
     non-overlapping occurrences of the RE in 'string' by the
     replacement 'replacement'.  If the pattern isn’t found, 'string' is
     returned unchanged.

     The optional argument 'count' is the maximum number of pattern
     occurrences to be replaced; 'count' must be a non-negative integer.
     The default value of 0 means to replace all occurrences.

Here’s a simple example of using the *note sub(): 2760. method.  It
replaces colour names with the word ‘colour’:

     >>> p = re.compile('(blue|white|red)')
     >>> p.sub('colour', 'blue socks and red shoes')
     'colour socks and colour shoes'
     >>> p.sub('colour', 'blue socks and red shoes', count=1)
     'colour socks and red shoes'

The *note subn(): 2761. method does the same work, but returns a 2-tuple
containing the new string value and the number of replacements that were
performed:

     >>> p = re.compile('(blue|white|red)')
     >>> p.subn('colour', 'blue socks and red shoes')
     ('colour socks and colour shoes', 2)
     >>> p.subn('colour', 'no colours at all')
     ('no colours at all', 0)

Empty matches are replaced only when they’re not adjacent to a previous
empty match.

     >>> p = re.compile('x*')
     >>> p.sub('-', 'abxd')
     '-a-b--d-'

If 'replacement' is a string, any backslash escapes in it are processed.
That is, ‘\n’ is converted to a single newline character, ‘\r’ is
converted to a carriage return, and so forth.  Unknown escapes such as
‘\&’ are left alone.  Backreferences, such as ‘\6’, are replaced with
the substring matched by the corresponding group in the RE. This lets
you incorporate portions of the original text in the resulting
replacement string.

This example matches the word ‘section’ followed by a string enclosed in
‘{’, ‘}’, and changes ‘section’ to ‘subsection’:

     >>> p = re.compile('section{ ( [^}]* ) }', re.VERBOSE)
     >>> p.sub(r'subsection{\1}','section{First} section{second}')
     'subsection{First} subsection{second}'

There’s also a syntax for referring to named groups as defined by the
‘(?P<name>...)’ syntax.  ‘\g<name>’ will use the substring matched by
the group named ‘name’, and ‘\g<number>’ uses the corresponding group
number.  ‘\g<2>’ is therefore equivalent to ‘\2’, but isn’t ambiguous in
a replacement string such as ‘\g<2>0’.  (‘\20’ would be interpreted as a
reference to group 20, not a reference to group 2 followed by the
literal character ‘'0'’.)  The following substitutions are all
equivalent, but use all three variations of the replacement string.

     >>> p = re.compile('section{ (?P<name> [^}]* ) }', re.VERBOSE)
     >>> p.sub(r'subsection{\1}','section{First}')
     'subsection{First}'
     >>> p.sub(r'subsection{\g<1>}','section{First}')
     'subsection{First}'
     >>> p.sub(r'subsection{\g<name>}','section{First}')
     'subsection{First}'

'replacement' can also be a function, which gives you even more control.
If 'replacement' is a function, the function is called for every
non-overlapping occurrence of 'pattern'.  On each call, the function is
passed a *note match object: 118a. argument for the match and can use
this information to compute the desired replacement string and return
it.

In the following example, the replacement function translates decimals
into hexadecimal:

     >>> def hexrepl(match):
     ...     "Return the hex string for a decimal number"
     ...     value = int(match.group())
     ...     return hex(value)
     ...
     >>> p = re.compile(r'\d+')
     >>> p.sub(hexrepl, 'Call 65490 for printing, 49152 for user code.')
     'Call 0xffd2 for printing, 0xc000 for user code.'

When using the module-level *note re.sub(): 5a3. function, the pattern
is passed as the first argument.  The pattern may be provided as an
object or as a string; if you need to specify regular expression flags,
you must either use a pattern object as the first parameter, or use
embedded modifiers in the pattern string, e.g.  ‘sub("(?i)b+", "x",
"bbbb BBBB")’ returns ‘'x x'’.


File: python.info,  Node: Common Problems,  Next: Feedback,  Prev: Modifying Strings,  Up: Regular Expression HOWTO

9.10.6 Common Problems
----------------------

Regular expressions are a powerful tool for some applications, but in
some ways their behaviour isn’t intuitive and at times they don’t behave
the way you may expect them to.  This section will point out some of the
most common pitfalls.

* Menu:

* Use String Methods::
* match() versus search(): match versus search.
* Greedy versus Non-Greedy::
* Using re.VERBOSE: Using re VERBOSE.


File: python.info,  Node: Use String Methods,  Next: match versus search,  Up: Common Problems

9.10.6.1 Use String Methods
...........................

Sometimes using the *note re: be. module is a mistake.  If you’re
matching a fixed string, or a single character class, and you’re not
using any *note re: be. features such as the *note IGNORECASE: 1a7e.
flag, then the full power of regular expressions may not be required.
Strings have several methods for performing operations with fixed
strings and they’re usually much faster, because the implementation is a
single small C loop that’s been optimized for the purpose, instead of
the large, more generalized regular expression engine.

One example might be replacing a single fixed string with another one;
for example, you might replace ‘word’ with ‘deed’.  *note re.sub(): 5a3.
seems like the function to use for this, but consider the *note
replace(): 4b9. method.  Note that ‘replace()’ will also replace ‘word’
inside words, turning ‘swordfish’ into ‘sdeedfish’, but the naive RE
‘word’ would have done that, too.  (To avoid performing the substitution
on parts of words, the pattern would have to be ‘\bword\b’, in order to
require that ‘word’ have a word boundary on either side.  This takes the
job beyond ‘replace()’”s abilities.)

Another common task is deleting every occurrence of a single character
from a string or replacing it with another single character.  You might
do this with something like ‘re.sub('\n', ' ', S)’, but *note
translate(): 2628. is capable of doing both tasks and will be faster
than any regular expression operation can be.

In short, before turning to the *note re: be. module, consider whether
your problem can be solved with a faster and simpler string method.


File: python.info,  Node: match versus search,  Next: Greedy versus Non-Greedy,  Prev: Use String Methods,  Up: Common Problems

9.10.6.2 match() versus search()
................................

The *note match(): 1435. function only checks if the RE matches at the
beginning of the string while *note search(): 1434. will scan forward
through the string for a match.  It’s important to keep this distinction
in mind.  Remember, ‘match()’ will only report a successful match which
will start at 0; if the match wouldn’t start at zero, ‘match()’ will
'not' report it.

     >>> print(re.match('super', 'superstition').span())
     (0, 5)
     >>> print(re.match('super', 'insuperable'))
     None

On the other hand, *note search(): 1434. will scan forward through the
string, reporting the first match it finds.

     >>> print(re.search('super', 'superstition').span())
     (0, 5)
     >>> print(re.search('super', 'insuperable').span())
     (2, 7)

Sometimes you’ll be tempted to keep using *note re.match(): 1435, and
just add ‘.*’ to the front of your RE. Resist this temptation and use
*note re.search(): 1434. instead.  The regular expression compiler does
some analysis of REs in order to speed up the process of looking for a
match.  One such analysis figures out what the first character of a
match must be; for example, a pattern starting with ‘Crow’ must match
starting with a ‘'C'’.  The analysis lets the engine quickly scan
through the string looking for the starting character, only trying the
full match if a ‘'C'’ is found.

Adding ‘.*’ defeats this optimization, requiring scanning to the end of
the string and then backtracking to find a match for the rest of the RE.
Use *note re.search(): 1434. instead.


File: python.info,  Node: Greedy versus Non-Greedy,  Next: Using re VERBOSE,  Prev: match versus search,  Up: Common Problems

9.10.6.3 Greedy versus Non-Greedy
.................................

When repeating a regular expression, as in ‘a*’, the resulting action is
to consume as much of the pattern as possible.  This fact often bites
you when you’re trying to match a pair of balanced delimiters, such as
the angle brackets surrounding an HTML tag.  The naive pattern for
matching a single HTML tag doesn’t work because of the greedy nature of
‘.*’.

     >>> s = '<html><head><title>Title</title>'
     >>> len(s)
     32
     >>> print(re.match('<.*>', s).span())
     (0, 32)
     >>> print(re.match('<.*>', s).group())
     <html><head><title>Title</title>

The RE matches the ‘'<'’ in ‘'<html>'’, and the ‘.*’ consumes the rest
of the string.  There’s still more left in the RE, though, and the ‘>’
can’t match at the end of the string, so the regular expression engine
has to backtrack character by character until it finds a match for the
‘>’.  The final match extends from the ‘'<'’ in ‘'<html>'’ to the ‘'>'’
in ‘'</title>'’, which isn’t what you want.

In this case, the solution is to use the non-greedy quantifiers ‘*?’,
‘+?’, ‘??’, or ‘{m,n}?’, which match as 'little' text as possible.  In
the above example, the ‘'>'’ is tried immediately after the first ‘'<'’
matches, and when it fails, the engine advances a character at a time,
retrying the ‘'>'’ at every step.  This produces just the right result:

     >>> print(re.match('<.*?>', s).group())
     <html>

(Note that parsing HTML or XML with regular expressions is painful.
Quick-and-dirty patterns will handle common cases, but HTML and XML have
special cases that will break the obvious regular expression; by the
time you’ve written a regular expression that handles all of the
possible cases, the patterns will be 'very' complicated.  Use an HTML or
XML parser module for such tasks.)


File: python.info,  Node: Using re VERBOSE,  Prev: Greedy versus Non-Greedy,  Up: Common Problems

9.10.6.4 Using re.VERBOSE
.........................

By now you’ve probably noticed that regular expressions are a very
compact notation, but they’re not terribly readable.  REs of moderate
complexity can become lengthy collections of backslashes, parentheses,
and metacharacters, making them difficult to read and understand.

For such REs, specifying the *note re.VERBOSE: 2755. flag when compiling
the regular expression can be helpful, because it allows you to format
the regular expression more clearly.

The ‘re.VERBOSE’ flag has several effects.  Whitespace in the regular
expression that 'isn’t' inside a character class is ignored.  This means
that an expression such as ‘dog | cat’ is equivalent to the less
readable ‘dog|cat’, but ‘[a b]’ will still match the characters ‘'a'’,
‘'b'’, or a space.  In addition, you can also put comments inside a RE;
comments extend from a ‘#’ character to the next newline.  When used
with triple-quoted strings, this enables REs to be formatted more
neatly:

     pat = re.compile(r"""
      \s*                 # Skip leading whitespace
      (?P<header>[^:]+)   # Header name
      \s* :               # Whitespace, and a colon
      (?P<value>.*?)      # The header's value -- *? used to
                          # lose the following trailing whitespace
      \s*$                # Trailing whitespace to end-of-line
     """, re.VERBOSE)

This is far more readable than:

     pat = re.compile(r"\s*(?P<header>[^:]+)\s*:(?P<value>.*?)\s*$")


File: python.info,  Node: Feedback,  Prev: Common Problems,  Up: Regular Expression HOWTO

9.10.7 Feedback
---------------

Regular expressions are a complicated topic.  Did this document help you
understand them?  Were there parts that were unclear, or Problems you
encountered that weren’t covered here?  If so, please send suggestions
for improvements to the author.

The most complete book on regular expressions is almost certainly
Jeffrey Friedl’s Mastering Regular Expressions, published by O’Reilly.
Unfortunately, it exclusively concentrates on Perl and Java’s flavours
of regular expressions, and doesn’t contain any Python material at all,
so it won’t be useful as a reference for programming in Python.  (The
first edition covered Python’s now-removed ‘regex’ module, which won’t
help you much.)  Consider checking it out from your library.


File: python.info,  Node: Socket Programming HOWTO,  Next: Sorting Techniques,  Prev: Regular Expression HOWTO,  Up: Python HOWTOs

9.11 Socket Programming HOWTO
=============================


Author: Gordon McMillan

Abstract
........

Sockets are used nearly everywhere, but are one of the most severely
misunderstood technologies around.  This is a 10,000 foot overview of
sockets.  It’s not really a tutorial - you’ll still have work to do in
getting things operational.  It doesn’t cover the fine points (and there
are a lot of them), but I hope it will give you enough background to
begin using them decently.

* Menu:

* Sockets::
* Creating a Socket::
* Using a Socket::
* Disconnecting::
* Non-blocking Sockets::


File: python.info,  Node: Sockets,  Next: Creating a Socket,  Up: Socket Programming HOWTO

9.11.1 Sockets
--------------

I’m only going to talk about INET (i.e.  IPv4) sockets, but they account
for at least 99% of the sockets in use.  And I’ll only talk about STREAM
(i.e.  TCP) sockets - unless you really know what you’re doing (in which
case this HOWTO isn’t for you!), you’ll get better behavior and
performance from a STREAM socket than anything else.  I will try to
clear up the mystery of what a socket is, as well as some hints on how
to work with blocking and non-blocking sockets.  But I’ll start by
talking about blocking sockets.  You’ll need to know how they work
before dealing with non-blocking sockets.

Part of the trouble with understanding these things is that «socket» can
mean a number of subtly different things, depending on context.  So
first, let’s make a distinction between a «client» socket - an endpoint
of a conversation, and a «server» socket, which is more like a
switchboard operator.  The client application (your browser, for
example) uses «client» sockets exclusively; the web server it’s talking
to uses both «server» sockets and «client» sockets.

* Menu:

* History::


File: python.info,  Node: History,  Up: Sockets

9.11.1.1 History
................

Of the various forms of IPC (Inter Process Communication), sockets are
by far the most popular.  On any given platform, there are likely to be
other forms of IPC that are faster, but for cross-platform
communication, sockets are about the only game in town.

They were invented in Berkeley as part of the BSD flavor of Unix.  They
spread like wildfire with the internet.  With good reason — the
combination of sockets with INET makes talking to arbitrary machines
around the world unbelievably easy (at least compared to other schemes).


File: python.info,  Node: Creating a Socket,  Next: Using a Socket,  Prev: Sockets,  Up: Socket Programming HOWTO

9.11.2 Creating a Socket
------------------------

Roughly speaking, when you clicked on the link that brought you to this
page, your browser did something like the following:

     # create an INET, STREAMing socket
     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     # now connect to the web server on port 80 - the normal http port
     s.connect(("www.python.org", 80))

When the ‘connect’ completes, the socket ‘s’ can be used to send in a
request for the text of the page.  The same socket will read the reply,
and then be destroyed.  That’s right, destroyed.  Client sockets are
normally only used for one exchange (or a small set of sequential
exchanges).

What happens in the web server is a bit more complex.  First, the web
server creates a «server socket»:

     # create an INET, STREAMing socket
     serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     # bind the socket to a public host, and a well-known port
     serversocket.bind((socket.gethostname(), 80))
     # become a server socket
     serversocket.listen(5)

A couple things to notice: we used ‘socket.gethostname()’ so that the
socket would be visible to the outside world.  If we had used
‘s.bind(('localhost', 80))’ or ‘s.bind(('127.0.0.1', 80))’ we would
still have a «server» socket, but one that was only visible within the
same machine.  ‘s.bind(('', 80))’ specifies that the socket is reachable
by any address the machine happens to have.

A second thing to note: low number ports are usually reserved for «well
known» services (HTTP, SNMP etc).  If you’re playing around, use a nice
high number (4 digits).

Finally, the argument to ‘listen’ tells the socket library that we want
it to queue up as many as 5 connect requests (the normal max) before
refusing outside connections.  If the rest of the code is written
properly, that should be plenty.

Now that we have a «server» socket, listening on port 80, we can enter
the mainloop of the web server:

     while True:
         # accept connections from outside
         (clientsocket, address) = serversocket.accept()
         # now do something with the clientsocket
         # in this case, we'll pretend this is a threaded server
         ct = make_client_thread(clientsocket)
         ct.start()

There’s actually 3 general ways in which this loop could work -
dispatching a thread to handle ‘clientsocket’, create a new process to
handle ‘clientsocket’, or restructure this app to use non-blocking
sockets, and multiplex between our «server» socket and any active
‘clientsocket’s using ‘select’.  More about that later.  The important
thing to understand now is this: this is 'all' a «server» socket does.
It doesn’t send any data.  It doesn’t receive any data.  It just
produces «client» sockets.  Each ‘clientsocket’ is created in response
to some 'other' «client» socket doing a ‘connect()’ to the host and port
we’re bound to.  As soon as we’ve created that ‘clientsocket’, we go
back to listening for more connections.  The two «clients» are free to
chat it up - they are using some dynamically allocated port which will
be recycled when the conversation ends.

* Menu:

* IPC::


File: python.info,  Node: IPC,  Up: Creating a Socket

9.11.2.1 IPC
............

If you need fast IPC between two processes on one machine, you should
look into pipes or shared memory.  If you do decide to use AF_INET
sockets, bind the «server» socket to ‘'localhost'’.  On most platforms,
this will take a shortcut around a couple of layers of network code and
be quite a bit faster.

Vedi anche
..........

The *note multiprocessing: 98. integrates cross-platform IPC into a
higher-level API.


File: python.info,  Node: Using a Socket,  Next: Disconnecting,  Prev: Creating a Socket,  Up: Socket Programming HOWTO

9.11.3 Using a Socket
---------------------

The first thing to note, is that the web browser’s «client» socket and
the web server’s «client» socket are identical beasts.  That is, this is
a «peer to peer» conversation.  Or to put it another way, 'as the
designer, you will have to decide what the rules of etiquette are for a
conversation'.  Normally, the ‘connect’ing socket starts the
conversation, by sending in a request, or perhaps a signon.  But that’s
a design decision - it’s not a rule of sockets.

Now there are two sets of verbs to use for communication.  You can use
‘send’ and ‘recv’, or you can transform your client socket into a
file-like beast and use ‘read’ and ‘write’.  The latter is the way Java
presents its sockets.  I’m not going to talk about it here, except to
warn you that you need to use ‘flush’ on sockets.  These are buffered
«files», and a common mistake is to ‘write’ something, and then ‘read’
for a reply.  Without a ‘flush’ in there, you may wait forever for the
reply, because the request may still be in your output buffer.

Now we come to the major stumbling block of sockets - ‘send’ and ‘recv’
operate on the network buffers.  They do not necessarily handle all the
bytes you hand them (or expect from them), because their major focus is
handling the network buffers.  In general, they return when the
associated network buffers have been filled (‘send’) or emptied
(‘recv’).  They then tell you how many bytes they handled.  It is 'your'
responsibility to call them again until your message has been completely
dealt with.

When a ‘recv’ returns 0 bytes, it means the other side has closed (or is
in the process of closing) the connection.  You will not receive any
more data on this connection.  Ever.  You may be able to send data
successfully; I’ll talk more about this later.

A protocol like HTTP uses a socket for only one transfer.  The client
sends a request, then reads a reply.  That’s it.  The socket is
discarded.  This means that a client can detect the end of the reply by
receiving 0 bytes.

But if you plan to reuse your socket for further transfers, you need to
realize that 'there is no' EOT (End of Transfer) 'on a socket.'  I
repeat: if a socket ‘send’ or ‘recv’ returns after handling 0 bytes, the
connection has been broken.  If the connection has 'not' been broken,
you may wait on a ‘recv’ forever, because the socket will 'not' tell you
that there’s nothing more to read (for now).  Now if you think about
that a bit, you’ll come to realize a fundamental truth of sockets:
'messages must either be fixed length' (yuck), 'or be delimited'
(shrug), 'or indicate how long they are' (much better), 'or end by
shutting down the connection'.  The choice is entirely yours, (but some
ways are righter than others).

Assuming you don’t want to end the connection, the simplest solution is
a fixed length message:

     class MySocket:
         """demonstration class only
           - coded for clarity, not efficiency
         """

         def __init__(self, sock=None):
             if sock is None:
                 self.sock = socket.socket(
                                 socket.AF_INET, socket.SOCK_STREAM)
             else:
                 self.sock = sock

         def connect(self, host, port):
             self.sock.connect((host, port))

         def mysend(self, msg):
             totalsent = 0
             while totalsent < MSGLEN:
                 sent = self.sock.send(msg[totalsent:])
                 if sent == 0:
                     raise RuntimeError("socket connection broken")
                 totalsent = totalsent + sent

         def myreceive(self):
             chunks = []
             bytes_recd = 0
             while bytes_recd < MSGLEN:
                 chunk = self.sock.recv(min(MSGLEN - bytes_recd, 2048))
                 if chunk == b'':
                     raise RuntimeError("socket connection broken")
                 chunks.append(chunk)
                 bytes_recd = bytes_recd + len(chunk)
             return b''.join(chunks)

The sending code here is usable for almost any messaging scheme - in
Python you send strings, and you can use ‘len()’ to determine its length
(even if it has embedded ‘\0’ characters).  It’s mostly the receiving
code that gets more complex.  (And in C, it’s not much worse, except you
can’t use ‘strlen’ if the message has embedded ‘\0’s.)

The easiest enhancement is to make the first character of the message an
indicator of message type, and have the type determine the length.  Now
you have two ‘recv’s - the first to get (at least) that first character
so you can look up the length, and the second in a loop to get the rest.
If you decide to go the delimited route, you’ll be receiving in some
arbitrary chunk size, (4096 or 8192 is frequently a good match for
network buffer sizes), and scanning what you’ve received for a
delimiter.

One complication to be aware of: if your conversational protocol allows
multiple messages to be sent back to back (without some kind of reply),
and you pass ‘recv’ an arbitrary chunk size, you may end up reading the
start of a following message.  You’ll need to put that aside and hold
onto it, until it’s needed.

Prefixing the message with its length (say, as 5 numeric characters)
gets more complex, because (believe it or not), you may not get all 5
characters in one ‘recv’.  In playing around, you’ll get away with it;
but in high network loads, your code will very quickly break unless you
use two ‘recv’ loops - the first to determine the length, the second to
get the data part of the message.  Nasty.  This is also when you’ll
discover that ‘send’ does not always manage to get rid of everything in
one pass.  And despite having read this, you will eventually get bit by
it!

In the interests of space, building your character, (and preserving my
competitive position), these enhancements are left as an exercise for
the reader.  Lets move on to cleaning up.

* Menu:

* Binary Data::


File: python.info,  Node: Binary Data,  Up: Using a Socket

9.11.3.1 Binary Data
....................

It is perfectly possible to send binary data over a socket.  The major
problem is that not all machines use the same formats for binary data.
For example, network byte order(1) is big-endian, with the most
significant byte first, so a 16 bit integer with the value ‘1’ would be
the two hex bytes ‘00 01’.  However, most common processors (x86/AMD64,
ARM, RISC-V), are little-endian, with the least significant byte first -
that same ‘1’ would be ‘01 00’.

Socket libraries have calls for converting 16 and 32 bit integers -
‘ntohl, htonl, ntohs, htons’ where «n» means 'network' and «h» means
'host', «s» means 'short' and «l» means 'long'.  Where network order is
host order, these do nothing, but where the machine is byte-reversed,
these swap the bytes around appropriately.

In these days of 64-bit machines, the ASCII representation of binary
data is frequently smaller than the binary representation.  That’s
because a surprising amount of the time, most integers have the value 0,
or maybe 1.  The string ‘"0"’ would be two bytes, while a full 64-bit
integer would be 8.  Of course, this doesn’t fit well with fixed-length
messages.  Decisions, decisions.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Endianness#Networking


File: python.info,  Node: Disconnecting,  Next: Non-blocking Sockets,  Prev: Using a Socket,  Up: Socket Programming HOWTO

9.11.4 Disconnecting
--------------------

Strictly speaking, you’re supposed to use ‘shutdown’ on a socket before
you ‘close’ it.  The ‘shutdown’ is an advisory to the socket at the
other end.  Depending on the argument you pass it, it can mean «I’m not
going to send anymore, but I’ll still listen», or «I’m not listening,
good riddance!».  Most socket libraries, however, are so used to
programmers neglecting to use this piece of etiquette that normally a
‘close’ is the same as ‘shutdown(); close()’.  So in most situations, an
explicit ‘shutdown’ is not needed.

One way to use ‘shutdown’ effectively is in an HTTP-like exchange.  The
client sends a request and then does a ‘shutdown(1)’.  This tells the
server «This client is done sending, but can still receive.» The server
can detect «EOF» by a receive of 0 bytes.  It can assume it has the
complete request.  The server sends a reply.  If the ‘send’ completes
successfully then, indeed, the client was still receiving.

Python takes the automatic shutdown a step further, and says that when a
socket is garbage collected, it will automatically do a ‘close’ if it’s
needed.  But relying on this is a very bad habit.  If your socket just
disappears without doing a ‘close’, the socket at the other end may hang
indefinitely, thinking you’re just being slow.  'Please' ‘close’ your
sockets when you’re done.

* Menu:

* When Sockets Die::


File: python.info,  Node: When Sockets Die,  Up: Disconnecting

9.11.4.1 When Sockets Die
.........................

Probably the worst thing about using blocking sockets is what happens
when the other side comes down hard (without doing a ‘close’).  Your
socket is likely to hang.  TCP is a reliable protocol, and it will wait
a long, long time before giving up on a connection.  If you’re using
threads, the entire thread is essentially dead.  There’s not much you
can do about it.  As long as you aren’t doing something dumb, like
holding a lock while doing a blocking read, the thread isn’t really
consuming much in the way of resources.  Do 'not' try to kill the thread
- part of the reason that threads are more efficient than processes is
that they avoid the overhead associated with the automatic recycling of
resources.  In other words, if you do manage to kill the thread, your
whole process is likely to be screwed up.


File: python.info,  Node: Non-blocking Sockets,  Prev: Disconnecting,  Up: Socket Programming HOWTO

9.11.5 Non-blocking Sockets
---------------------------

If you’ve understood the preceding, you already know most of what you
need to know about the mechanics of using sockets.  You’ll still use the
same calls, in much the same ways.  It’s just that, if you do it right,
your app will be almost inside-out.

In Python, you use ‘socket.setblocking(False)’ to make it non-blocking.
In C, it’s more complex, (for one thing, you’ll need to choose between
the BSD flavor ‘O_NONBLOCK’ and the almost indistinguishable POSIX
flavor ‘O_NDELAY’, which is completely different from ‘TCP_NODELAY’),
but it’s the exact same idea.  You do this after creating the socket,
but before using it.  (Actually, if you’re nuts, you can switch back and
forth.)

The major mechanical difference is that ‘send’, ‘recv’, ‘connect’ and
‘accept’ can return without having done anything.  You have (of course)
a number of choices.  You can check return code and error codes and
generally drive yourself crazy.  If you don’t believe me, try it
sometime.  Your app will grow large, buggy and suck CPU. So let’s skip
the brain-dead solutions and do it right.

Use ‘select’.

In C, coding ‘select’ is fairly complex.  In Python, it’s a piece of
cake, but it’s close enough to the C version that if you understand
‘select’ in Python, you’ll have little trouble with it in C:

     ready_to_read, ready_to_write, in_error = \
                    select.select(
                       potential_readers,
                       potential_writers,
                       potential_errs,
                       timeout)

You pass ‘select’ three lists: the first contains all sockets that you
might want to try reading; the second all the sockets you might want to
try writing to, and the last (normally left empty) those that you want
to check for errors.  You should note that a socket can go into more
than one list.  The ‘select’ call is blocking, but you can give it a
timeout.  This is generally a sensible thing to do - give it a nice long
timeout (say a minute) unless you have good reason to do otherwise.

In return, you will get three lists.  They contain the sockets that are
actually readable, writable and in error.  Each of these lists is a
subset (possibly empty) of the corresponding list you passed in.

If a socket is in the output readable list, you can be
as-close-to-certain-as-we-ever-get-in-this-business that a ‘recv’ on
that socket will return 'something'.  Same idea for the writable list.
You’ll be able to send 'something'.  Maybe not all you want to, but
'something' is better than nothing.  (Actually, any reasonably healthy
socket will return as writable - it just means outbound network buffer
space is available.)

If you have a «server» socket, put it in the potential_readers list.  If
it comes out in the readable list, your ‘accept’ will (almost certainly)
work.  If you have created a new socket to ‘connect’ to someone else,
put it in the potential_writers list.  If it shows up in the writable
list, you have a decent chance that it has connected.

Actually, ‘select’ can be handy even with blocking sockets.  It’s one
way of determining whether you will block - the socket returns as
readable when there’s something in the buffers.  However, this still
doesn’t help with the problem of determining whether the other end is
done, or just busy with something else.

'Portability alert': On Unix, ‘select’ works both with the sockets and
files.  Don’t try this on Windows.  On Windows, ‘select’ works with
sockets only.  Also note that in C, many of the more advanced socket
options are done differently on Windows.  In fact, on Windows I usually
use threads (which work very, very well) with my sockets.


File: python.info,  Node: Sorting Techniques,  Next: Unicode HOWTO,  Prev: Socket Programming HOWTO,  Up: Python HOWTOs

9.12 Sorting Techniques
=======================


Author: Andrew Dalke and Raymond Hettinger

Python lists have a built-in *note list.sort(): dca. method that
modifies the list in-place.  There is also a *note sorted(): dc9.
built-in function that builds a new sorted list from an iterable.

In this document, we explore the various techniques for sorting data
using Python.

* Menu:

* Sorting Basics::
* Key Functions::
* Operator Module Functions and Partial Function Evaluation::
* Ascending and Descending::
* Sort Stability and Complex Sorts::
* Decorate-Sort-Undecorate::
* Comparison Functions::
* Strategies For Unorderable Types and Values::
* Odds and Ends::
* Partial Sorts::


File: python.info,  Node: Sorting Basics,  Next: Key Functions,  Up: Sorting Techniques

9.12.1 Sorting Basics
---------------------

A simple ascending sort is very easy: just call the *note sorted(): dc9.
function.  It returns a new sorted list:

     >>> sorted([5, 2, 3, 1, 4])
     [1, 2, 3, 4, 5]

You can also use the *note list.sort(): dca. method.  It modifies the
list in-place (and returns ‘None’ to avoid confusion).  Usually it’s
less convenient than *note sorted(): dc9. - but if you don’t need the
original list, it’s slightly more efficient.

     >>> a = [5, 2, 3, 1, 4]
     >>> a.sort()
     >>> a
     [1, 2, 3, 4, 5]

Another difference is that the *note list.sort(): dca. method is only
defined for lists.  In contrast, the *note sorted(): dc9. function
accepts any iterable.

     >>> sorted({1: 'D', 2: 'B', 3: 'B', 4: 'E', 5: 'A'})
     [1, 2, 3, 4, 5]


File: python.info,  Node: Key Functions,  Next: Operator Module Functions and Partial Function Evaluation,  Prev: Sorting Basics,  Up: Sorting Techniques

9.12.2 Key Functions
--------------------

The *note list.sort(): dca. method and the functions *note sorted():
dc9, *note min(): 110d, *note max(): 110e, *note heapq.nsmallest():
298a, and *note heapq.nlargest(): 2989. have a 'key' parameter to
specify a function (or other callable) to be called on each list element
prior to making comparisons.

For example, here’s a case-insensitive string comparison using *note
str.casefold(): fd8.:

     >>> sorted("This is a test string from Andrew".split(), key=str.casefold)
     ['a', 'Andrew', 'from', 'is', 'string', 'test', 'This']

The value of the 'key' parameter should be a function (or other
callable) that takes a single argument and returns a key to use for
sorting purposes.  This technique is fast because the key function is
called exactly once for each input record.

A common pattern is to sort complex objects using some of the object’s
indices as keys.  For example:

     >>> student_tuples = [
     ...     ('john', 'A', 15),
     ...     ('jane', 'B', 12),
     ...     ('dave', 'B', 10),
     ... ]
     >>> sorted(student_tuples, key=lambda student: student[2])   # sort by age
     [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

The same technique works for objects with named attributes.  For
example:

     >>> class Student:
     ...     def __init__(self, name, grade, age):
     ...         self.name = name
     ...         self.grade = grade
     ...         self.age = age
     ...     def __repr__(self):
     ...         return repr((self.name, self.grade, self.age))

     >>> student_objects = [
     ...     Student('john', 'A', 15),
     ...     Student('jane', 'B', 12),
     ...     Student('dave', 'B', 10),
     ... ]
     >>> sorted(student_objects, key=lambda student: student.age)   # sort by age
     [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

Objects with named attributes can be made by a regular class as shown
above, or they can be instances of *note dataclass: 4e2. or a *note
named tuple: 85f.


File: python.info,  Node: Operator Module Functions and Partial Function Evaluation,  Next: Ascending and Descending,  Prev: Key Functions,  Up: Sorting Techniques

9.12.3 Operator Module Functions and Partial Function Evaluation
----------------------------------------------------------------

The *note key function: 1008. patterns shown above are very common, so
Python provides convenience functions to make accessor functions easier
and faster.  The *note operator: a3. module has *note itemgetter(): c59,
*note attrgetter(): 1035, and a *note methodcaller(): 1036. function.

Using those functions, the above examples become simpler and faster:

     >>> from operator import itemgetter, attrgetter

     >>> sorted(student_tuples, key=itemgetter(2))
     [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

     >>> sorted(student_objects, key=attrgetter('age'))
     [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

The operator module functions allow multiple levels of sorting.  For
example, to sort by 'grade' then by 'age':

     >>> sorted(student_tuples, key=itemgetter(1,2))
     [('john', 'A', 15), ('dave', 'B', 10), ('jane', 'B', 12)]

     >>> sorted(student_objects, key=attrgetter('grade', 'age'))
     [('john', 'A', 15), ('dave', 'B', 10), ('jane', 'B', 12)]

The *note functools: 63. module provides another helpful tool for making
key-functions.  The *note partial(): 217. function can reduce the
arity(1) of a multi-argument function making it suitable for use as a
key-function.

     >>> from functools import partial
     >>> from unicodedata import normalize

     >>> names = 'Zoë Åbjørn Núñez Élana Zeke Abe Nubia Eloise'.split()

     >>> sorted(names, key=partial(normalize, 'NFD'))
     ['Abe', 'Åbjørn', 'Eloise', 'Élana', 'Nubia', 'Núñez', 'Zeke', 'Zoë']

     >>> sorted(names, key=partial(normalize, 'NFC'))
     ['Abe', 'Eloise', 'Nubia', 'Núñez', 'Zeke', 'Zoë', 'Åbjørn', 'Élana']

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Arity


File: python.info,  Node: Ascending and Descending,  Next: Sort Stability and Complex Sorts,  Prev: Operator Module Functions and Partial Function Evaluation,  Up: Sorting Techniques

9.12.4 Ascending and Descending
-------------------------------

Both *note list.sort(): dca. and *note sorted(): dc9. accept a 'reverse'
parameter with a boolean value.  This is used to flag descending sorts.
For example, to get the student data in reverse 'age' order:

     >>> sorted(student_tuples, key=itemgetter(2), reverse=True)
     [('john', 'A', 15), ('jane', 'B', 12), ('dave', 'B', 10)]

     >>> sorted(student_objects, key=attrgetter('age'), reverse=True)
     [('john', 'A', 15), ('jane', 'B', 12), ('dave', 'B', 10)]


File: python.info,  Node: Sort Stability and Complex Sorts,  Next: Decorate-Sort-Undecorate,  Prev: Ascending and Descending,  Up: Sorting Techniques

9.12.5 Sort Stability and Complex Sorts
---------------------------------------

Sorts are guaranteed to be stable(1).  That means that when multiple
records have the same key, their original order is preserved.

     >>> data = [('red', 1), ('blue', 1), ('red', 2), ('blue', 2)]
     >>> sorted(data, key=itemgetter(0))
     [('blue', 1), ('blue', 2), ('red', 1), ('red', 2)]

Notice how the two records for 'blue' retain their original order so
that ‘('blue', 1)’ is guaranteed to precede ‘('blue', 2)’.

This wonderful property lets you build complex sorts in a series of
sorting steps.  For example, to sort the student data by descending
'grade' and then ascending 'age', do the 'age' sort first and then sort
again using 'grade':

     >>> s = sorted(student_objects, key=attrgetter('age'))     # sort on secondary key
     >>> sorted(s, key=attrgetter('grade'), reverse=True)       # now sort on primary key, descending
     [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

This can be abstracted out into a wrapper function that can take a list
and tuples of field and order to sort them on multiple passes.

     >>> def multisort(xs, specs):
     ...     for key, reverse in reversed(specs):
     ...         xs.sort(key=attrgetter(key), reverse=reverse)
     ...     return xs

     >>> multisort(list(student_objects), (('grade', True), ('age', False)))
     [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

The Timsort(2) algorithm used in Python does multiple sorts efficiently
because it can take advantage of any ordering already present in a
dataset.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Sorting_algorithm#Stability

   (2) https://en.wikipedia.org/wiki/Timsort


File: python.info,  Node: Decorate-Sort-Undecorate,  Next: Comparison Functions,  Prev: Sort Stability and Complex Sorts,  Up: Sorting Techniques

9.12.6 Decorate-Sort-Undecorate
-------------------------------

This idiom is called Decorate-Sort-Undecorate after its three steps:

   * First, the initial list is decorated with new values that control
     the sort order.

   * Second, the decorated list is sorted.

   * Finally, the decorations are removed, creating a list that contains
     only the initial values in the new order.

For example, to sort the student data by 'grade' using the DSU approach:

     >>> decorated = [(student.grade, i, student) for i, student in enumerate(student_objects)]
     >>> decorated.sort()
     >>> [student for grade, i, student in decorated]               # undecorate
     [('john', 'A', 15), ('jane', 'B', 12), ('dave', 'B', 10)]

This idiom works because tuples are compared lexicographically; the
first items are compared; if they are the same then the second items are
compared, and so on.

It is not strictly necessary in all cases to include the index 'i' in
the decorated list, but including it gives two benefits:

   * The sort is stable – if two items have the same key, their order
     will be preserved in the sorted list.

   * The original items do not have to be comparable because the
     ordering of the decorated tuples will be determined by at most the
     first two items.  So for example the original list could contain
     complex numbers which cannot be sorted directly.

Another name for this idiom is Schwartzian transform(1), after Randal L.
Schwartz, who popularized it among Perl programmers.

Now that Python sorting provides key-functions, this technique is not
often needed.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Schwartzian_transform


File: python.info,  Node: Comparison Functions,  Next: Strategies For Unorderable Types and Values,  Prev: Decorate-Sort-Undecorate,  Up: Sorting Techniques

9.12.7 Comparison Functions
---------------------------

Unlike key functions that return an absolute value for sorting, a
comparison function computes the relative ordering for two inputs.

For example, a balance scale(1) compares two samples giving a relative
ordering: lighter, equal, or heavier.  Likewise, a comparison function
such as ‘cmp(a, b)’ will return a negative value for less-than, zero if
the inputs are equal, or a positive value for greater-than.

It is common to encounter comparison functions when translating
algorithms from other languages.  Also, some libraries provide
comparison functions as part of their API. For example, *note
locale.strcoll(): 42b1. is a comparison function.

To accommodate those situations, Python provides *note
functools.cmp_to_key: 13e2. to wrap the comparison function to make it
usable as a key function:

     sorted(words, key=cmp_to_key(strcoll))  # locale-aware sort order

   ---------- Footnotes ----------

   (1) 
https://upload.wikimedia.org/wikipedia/commons/1/17/Balance_à_tabac_1850.JPG


File: python.info,  Node: Strategies For Unorderable Types and Values,  Next: Odds and Ends,  Prev: Comparison Functions,  Up: Sorting Techniques

9.12.8 Strategies For Unorderable Types and Values
--------------------------------------------------

A number of type and value issues can arise when sorting.  Here are some
strategies that can help:

   * Convert non-comparable input types to strings prior to sorting:

     >>> data = ['twelve', '11', 10]
     >>> sorted(map(str, data))
     ['10', '11', 'twelve']

This is needed because most cross-type comparisons raise a *note
TypeError: 198.

   * Remove special values prior to sorting:

     >>> from math import isnan
     >>> from itertools import filterfalse
     >>> data = [3.3, float('nan'), 1.1, 2.2]
     >>> sorted(filterfalse(isnan, data))
     [1.1, 2.2, 3.3]

This is needed because the IEEE-754 standard(1) specifies that, «Every
NaN shall compare unordered with everything, including itself.»

Likewise, ‘None’ can be stripped from datasets as well:

     >>> data = [3.3, None, 1.1, 2.2]
     >>> sorted(x for x in data if x is not None)
     [1.1, 2.2, 3.3]

This is needed because ‘None’ is not comparable to other types.

   * Convert mapping types into sorted item lists before sorting:

     >>> data = [{'a': 1}, {'b': 2}]
     >>> sorted(data, key=lambda d: sorted(d.items()))
     [{'a': 1}, {'b': 2}]

This is needed because dict-to-dict comparisons raise a *note TypeError:
198.

   * Convert set types into sorted lists before sorting:

     >>> data = [{'a', 'b', 'c'}, {'b', 'c', 'd'}]
     >>> sorted(map(sorted, data))
     [['a', 'b', 'c'], ['b', 'c', 'd']]

This is needed because the elements contained in set types do not have a
deterministic order.  For example, ‘list({'a', 'b'})’ may produce either
‘['a', 'b']’ or ‘['b', 'a']’.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/IEEE_754


File: python.info,  Node: Odds and Ends,  Next: Partial Sorts,  Prev: Strategies For Unorderable Types and Values,  Up: Sorting Techniques

9.12.9 Odds and Ends
--------------------

   * For locale aware sorting, use *note locale.strxfrm(): 17a5. for a
     key function or *note locale.strcoll(): 42b1. for a comparison
     function.  This is necessary because «alphabetical» sort orderings
     can vary across cultures even if the underlying alphabet is the
     same.

   * The 'reverse' parameter still maintains sort stability (so that
     records with equal keys retain the original order).  Interestingly,
     that effect can be simulated without the parameter by using the
     builtin *note reversed(): a67. function twice:

          >>> data = [('red', 1), ('blue', 1), ('red', 2), ('blue', 2)]
          >>> standard_way = sorted(data, key=itemgetter(0), reverse=True)
          >>> double_reversed = list(reversed(sorted(reversed(data), key=itemgetter(0))))
          >>> assert standard_way == double_reversed
          >>> standard_way
          [('red', 1), ('red', 2), ('blue', 1), ('blue', 2)]

   * The sort routines use ‘<’ when making comparisons between two
     objects.  So, it is easy to add a standard sort order to a class by
     defining an *note __lt__(): 14a8. method:

          >>> Student.__lt__ = lambda self, other: self.age < other.age
          >>> sorted(student_objects)
          [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

     However, note that ‘<’ can fall back to using *note __gt__(): 1513.
     if *note __lt__(): 14a8. is not implemented (see *note
     object.__lt__(): 14a8. for details on the mechanics).  To avoid
     surprises, PEP 8(1) recommends that all six comparison methods be
     implemented.  The *note total_ordering(): 1144. decorator is
     provided to make that task easier.

   * Key functions need not depend directly on the objects being sorted.
     A key function can also access external resources.  For instance,
     if the student grades are stored in a dictionary, they can be used
     to sort a separate list of student names:

          >>> students = ['dave', 'john', 'jane']
          >>> newgrades = {'john': 'F', 'jane':'A', 'dave': 'C'}
          >>> sorted(students, key=newgrades.__getitem__)
          ['jane', 'dave', 'john']

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0008/


File: python.info,  Node: Partial Sorts,  Prev: Odds and Ends,  Up: Sorting Techniques

9.12.10 Partial Sorts
---------------------

Some applications require only some of the data to be ordered.  The
standard library provides several tools that do less work than a full
sort:

   * *note min(): 110d. and *note max(): 110e. return the smallest and
     largest values, respectively.  These functions make a single pass
     over the input data and require almost no auxiliary memory.

   * *note heapq.nsmallest(): 298a. and *note heapq.nlargest(): 2989.
     return the 'n' smallest and largest values, respectively.  These
     functions make a single pass over the data keeping only 'n'
     elements in memory at a time.  For values of 'n' that are small
     relative to the number of inputs, these functions make far fewer
     comparisons than a full sort.

   * *note heapq.heappush(): 16c3. and *note heapq.heappop(): 16c4.
     create and maintain a partially sorted arrangement of data that
     keeps the smallest element at position ‘0’.  These functions are
     suitable for implementing priority queues which are commonly used
     for task scheduling.


File: python.info,  Node: Unicode HOWTO,  Next: HOWTO Fetch Internet Resources Using The urllib Package,  Prev: Sorting Techniques,  Up: Python HOWTOs

9.13 Unicode HOWTO
==================


Release: 1.12

This HOWTO discusses Python’s support for the Unicode specification for
representing textual data, and explains various problems that people
commonly encounter when trying to work with Unicode.

* Menu:

* Introduction to Unicode::
* Python’s Unicode Support::
* Reading and Writing Unicode Data::
* Acknowledgements: Acknowledgements<10>.


File: python.info,  Node: Introduction to Unicode,  Next: Python’s Unicode Support,  Up: Unicode HOWTO

9.13.1 Introduction to Unicode
------------------------------

* Menu:

* Definitions::
* Encodings::
* References: References<3>.


File: python.info,  Node: Definitions,  Next: Encodings,  Up: Introduction to Unicode

9.13.1.1 Definitions
....................

Today’s programs need to be able to handle a wide variety of characters.
Applications are often internationalized to display messages and output
in a variety of user-selectable languages; the same program might need
to output an error message in English, French, Japanese, Hebrew, or
Russian.  Web content can be written in any of these languages and can
also include a variety of emoji symbols.  Python’s string type uses the
Unicode Standard for representing characters, which lets Python programs
work with all these different possible characters.

Unicode (‘https://www.unicode.org/’) is a specification that aims to
list every character used by human languages and give each character its
own unique code.  The Unicode specifications are continually revised and
updated to add new languages and symbols.

A 'character' is the smallest possible component of a text.  “A”, “B”,
“C”, etc., are all different characters.  So are “È” and “Í”.
Characters vary depending on the language or context you’re talking
about.  For example, there’s a character for «Roman Numeral One», “Ⅰ”,
that’s separate from the uppercase letter “I”.  They’ll usually look the
same, but these are two different characters that have different
meanings.

The Unicode standard describes how characters are represented by 'code
points'.  A code point value is an integer in the range 0 to 0x10FFFF
(about 1.1 million values, the actual number assigned(1) is less than
that).  In the standard and in this document, a code point is written
using the notation ‘U+265E’ to mean the character with value ‘0x265e’
(9,822 in decimal).

The Unicode standard contains a lot of tables listing characters and
their corresponding code points:

     0061    'a'; LATIN SMALL LETTER A
     0062    'b'; LATIN SMALL LETTER B
     0063    'c'; LATIN SMALL LETTER C
     ...
     007B    '{'; LEFT CURLY BRACKET
     ...
     2167    'Ⅷ'; ROMAN NUMERAL EIGHT
     2168    'Ⅸ'; ROMAN NUMERAL NINE
     ...
     265E    '♞'; BLACK CHESS KNIGHT
     265F    '♟'; BLACK CHESS PAWN
     ...
     1F600   '😀'; GRINNING FACE
     1F609   '😉'; WINKING FACE
     ...

Strictly, these definitions imply that it’s meaningless to say “this is
character ‘U+265E’”.  ‘U+265E’ is a code point, which represents some
particular character; in this case, it represents the character “BLACK
CHESS KNIGHT”, “♞”.  In informal contexts, this distinction between code
points and characters will sometimes be forgotten.

A character is represented on a screen or on paper by a set of graphical
elements that’s called a 'glyph'.  The glyph for an uppercase A, for
example, is two diagonal strokes and a horizontal stroke, though the
exact details will depend on the font being used.  Most Python code
doesn’t need to worry about glyphs; figuring out the correct glyph to
display is generally the job of a GUI toolkit or a terminal’s font
renderer.

   ---------- Footnotes ----------

   (1) https://www.unicode.org/versions/latest/#Summary


File: python.info,  Node: Encodings,  Next: References<3>,  Prev: Definitions,  Up: Introduction to Unicode

9.13.1.2 Encodings
..................

To summarize the previous section: a Unicode string is a sequence of
code points, which are numbers from 0 through ‘0x10FFFF’ (1,114,111
decimal).  This sequence of code points needs to be represented in
memory as a set of 'code units', and 'code units' are then mapped to
8-bit bytes.  The rules for translating a Unicode string into a sequence
of bytes are called a 'character encoding', or just an 'encoding'.

The first encoding you might think of is using 32-bit integers as the
code unit, and then using the CPU’s representation of 32-bit integers.
In this representation, the string «Python» might look like this:

        P           y           t           h           o           n
     0x50 00 00 00 79 00 00 00 74 00 00 00 68 00 00 00 6f 00 00 00 6e 00 00 00
        0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

This representation is straightforward but using it presents a number of
problems.

  1. It’s not portable; different processors order the bytes
     differently.

  2. It’s very wasteful of space.  In most texts, the majority of the
     code points are less than 127, or less than 255, so a lot of space
     is occupied by ‘0x00’ bytes.  The above string takes 24 bytes
     compared to the 6 bytes needed for an ASCII representation.
     Increased RAM usage doesn’t matter too much (desktop computers have
     gigabytes of RAM, and strings aren’t usually that large), but
     expanding our usage of disk and network bandwidth by a factor of 4
     is intolerable.

  3. It’s not compatible with existing C functions such as ‘strlen()’,
     so a new family of wide string functions would need to be used.

Therefore this encoding isn’t used very much, and people instead choose
other encodings that are more efficient and convenient, such as UTF-8.

UTF-8 is one of the most commonly used encodings, and Python often
defaults to using it.  UTF stands for «Unicode Transformation Format»,
and the “8” means that 8-bit values are used in the encoding.  (There
are also UTF-16 and UTF-32 encodings, but they are less frequently used
than UTF-8.)  UTF-8 uses the following rules:

  1. If the code point is < 128, it’s represented by the corresponding
     byte value.

  2. If the code point is >= 128, it’s turned into a sequence of two,
     three, or four bytes, where each byte of the sequence is between
     128 and 255.

UTF-8 has several convenient properties:

  1. It can handle any Unicode code point.

  2. A Unicode string is turned into a sequence of bytes that contains
     embedded zero bytes only where they represent the null character
     (U+0000).  This means that UTF-8 strings can be processed by C
     functions such as ‘strcpy()’ and sent through protocols that can’t
     handle zero bytes for anything other than end-of-string markers.

  3. A string of ASCII text is also valid UTF-8 text.

  4. UTF-8 is fairly compact; the majority of commonly used characters
     can be represented with one or two bytes.

  5. If bytes are corrupted or lost, it’s possible to determine the
     start of the next UTF-8-encoded code point and resynchronize.  It’s
     also unlikely that random 8-bit data will look like valid UTF-8.

  6. UTF-8 is a byte oriented encoding.  The encoding specifies that
     each character is represented by a specific sequence of one or more
     bytes.  This avoids the byte-ordering issues that can occur with
     integer and word oriented encodings, like UTF-16 and UTF-32, where
     the sequence of bytes varies depending on the hardware on which the
     string was encoded.


File: python.info,  Node: References<3>,  Prev: Encodings,  Up: Introduction to Unicode

9.13.1.3 References
...................

The Unicode Consortium site(1) has character charts, a glossary, and PDF
versions of the Unicode specification.  Be prepared for some difficult
reading.  A chronology(2) of the origin and development of Unicode is
also available on the site.

On the Computerphile Youtube channel, Tom Scott briefly discusses the
history of Unicode and UTF-8(3) (9 minutes 36 seconds).

To help understand the standard, Jukka Korpela has written an
introductory guide(4) to reading the Unicode character tables.

Another good introductory article(5) was written by Joel Spolsky.  If
this introduction didn’t make things clear to you, you should try
reading this alternate article before continuing.

Wikipedia entries are often helpful; see the entries for «character
encoding(6)» and UTF-8(7), for example.

   ---------- Footnotes ----------

   (1) https://www.unicode.org

   (2) https://www.unicode.org/history/

   (3) https://www.youtube.com/watch?v=MijmeoH9LT4

   (4) https://jkorpela.fi/unicode/guide.html

   (5) 
https://www.joelonsoftware.com/2003/10/08/the-absolute-minimum-every-software-developer-absolutely-positively-must-know-about-unicode-and-character-sets-no-excuses/

   (6) https://en.wikipedia.org/wiki/Character_encoding

   (7) https://en.wikipedia.org/wiki/UTF-8


File: python.info,  Node: Python’s Unicode Support,  Next: Reading and Writing Unicode Data,  Prev: Introduction to Unicode,  Up: Unicode HOWTO

9.13.2 Python’s Unicode Support
-------------------------------

Now that you’ve learned the rudiments of Unicode, we can look at
Python’s Unicode features.

* Menu:

* The String Type::
* Converting to Bytes::
* Unicode Literals in Python Source Code::
* Unicode Properties::
* Comparing Strings::
* Unicode Regular Expressions::
* References: References<4>.


File: python.info,  Node: The String Type,  Next: Converting to Bytes,  Up: Python’s Unicode Support

9.13.2.1 The String Type
........................

Since Python 3.0, the language’s *note str: 169. type contains Unicode
characters, meaning any string created using ‘"unicode rocks!"’,
‘'unicode rocks!'’, or the triple-quoted string syntax is stored as
Unicode.

The default encoding for Python source code is UTF-8, so you can simply
include a Unicode character in a string literal:

     try:
         with open('/tmp/input.txt', 'r') as f:
             ...
     except OSError:
         # 'File not found' error message.
         print("Fichier non trouvé")

Side note: Python 3 also supports using Unicode characters in
identifiers:

     répertoire = "/tmp/records.log"
     with open(répertoire, "w") as f:
         f.write("test\n")

If you can’t enter a particular character in your editor or want to keep
the source code ASCII-only for some reason, you can also use escape
sequences in string literals.  (Depending on your system, you may see
the actual capital-delta glyph instead of a u escape.)

     >>> "\N{GREEK CAPITAL LETTER DELTA}"  # Using the character name
     '\u0394'
     >>> "\u0394"                          # Using a 16-bit hex value
     '\u0394'
     >>> "\U00000394"                      # Using a 32-bit hex value
     '\u0394'

In addition, one can create a string using the *note decode(): ad5.
method of *note bytes: 192.  This method takes an 'encoding' argument,
such as ‘UTF-8’, and optionally an 'errors' argument.

The 'errors' argument specifies the response when the input string can’t
be converted according to the encoding’s rules.  Legal values for this
argument are ‘'strict'’ (raise a *note UnicodeDecodeError: c0a.
exception), ‘'replace'’ (use ‘U+FFFD’, ‘REPLACEMENT CHARACTER’),
‘'ignore'’ (just leave the character out of the Unicode result), or
‘'backslashreplace'’ (inserts a ‘\xNN’ escape sequence).  The following
examples show the differences:

     >>> b'\x80abc'.decode("utf-8", "strict")
     Traceback (most recent call last):
         ...
     UnicodeDecodeError: 'utf-8' codec can't decode byte 0x80 in position 0:
       invalid start byte
     >>> b'\x80abc'.decode("utf-8", "replace")
     '\ufffdabc'
     >>> b'\x80abc'.decode("utf-8", "backslashreplace")
     '\\x80abc'
     >>> b'\x80abc'.decode("utf-8", "ignore")
     'abc'

Encodings are specified as strings containing the encoding’s name.
Python comes with roughly 100 different encodings; see the Python
Library Reference at *note Standard Encodings: fba. for a list.  Some
encodings have multiple names; for example, ‘'latin-1'’, ‘'iso_8859_1'’
and ‘'8859’” are all synonyms for the same encoding.

One-character Unicode strings can also be created with the *note chr():
19d7. built-in function, which takes integers and returns a Unicode
string of length 1 that contains the corresponding code point.  The
reverse operation is the built-in *note ord(): 2323. function that takes
a one-character Unicode string and returns the code point value:

     >>> chr(57344)
     '\ue000'
     >>> ord('\ue000')
     57344


File: python.info,  Node: Converting to Bytes,  Next: Unicode Literals in Python Source Code,  Prev: The String Type,  Up: Python’s Unicode Support

9.13.2.2 Converting to Bytes
............................

The opposite method of *note bytes.decode(): ad5. is *note str.encode():
ad4, which returns a *note bytes: 192. representation of the Unicode
string, encoded in the requested 'encoding'.

The 'errors' parameter is the same as the parameter of the *note
decode(): ad5. method but supports a few more possible handlers.  As
well as ‘'strict'’, ‘'ignore'’, and ‘'replace'’ (which in this case
inserts a question mark instead of the unencodable character), there is
also ‘'xmlcharrefreplace'’ (inserts an XML character reference),
‘backslashreplace’ (inserts a ‘\uNNNN’ escape sequence) and
‘namereplace’ (inserts a ‘\N{...}’ escape sequence).

The following example shows the different results:

     >>> u = chr(40960) + 'abcd' + chr(1972)
     >>> u.encode('utf-8')
     b'\xea\x80\x80abcd\xde\xb4'
     >>> u.encode('ascii')
     Traceback (most recent call last):
         ...
     UnicodeEncodeError: 'ascii' codec can't encode character '\ua000' in
       position 0: ordinal not in range(128)
     >>> u.encode('ascii', 'ignore')
     b'abcd'
     >>> u.encode('ascii', 'replace')
     b'?abcd?'
     >>> u.encode('ascii', 'xmlcharrefreplace')
     b'&#40960;abcd&#1972;'
     >>> u.encode('ascii', 'backslashreplace')
     b'\\ua000abcd\\u07b4'
     >>> u.encode('ascii', 'namereplace')
     b'\\N{YI SYLLABLE IT}abcd\\u07b4'

The low-level routines for registering and accessing the available
encodings are found in the *note codecs: 1c. module.  Implementing new
encodings also requires understanding the *note codecs: 1c. module.
However, the encoding and decoding functions returned by this module are
usually more low-level than is comfortable, and writing new encodings is
a specialized task, so the module won’t be covered in this HOWTO.


File: python.info,  Node: Unicode Literals in Python Source Code,  Next: Unicode Properties,  Prev: Converting to Bytes,  Up: Python’s Unicode Support

9.13.2.3 Unicode Literals in Python Source Code
...............................................

In Python source code, specific Unicode code points can be written using
the ‘\u’ escape sequence, which is followed by four hex digits giving
the code point.  The ‘\U’ escape sequence is similar, but expects eight
hex digits, not four:

     >>> s = "a\xac\u1234\u20ac\U00008000"
     ... #     ^^^^ two-digit hex escape
     ... #         ^^^^^^ four-digit Unicode escape
     ... #                     ^^^^^^^^^^ eight-digit Unicode escape
     >>> [ord(c) for c in s]
     [97, 172, 4660, 8364, 32768]

Using escape sequences for code points greater than 127 is fine in small
doses, but becomes an annoyance if you’re using many accented
characters, as you would in a program with messages in French or some
other accent-using language.  You can also assemble strings using the
*note chr(): 19d7. built-in function, but this is even more tedious.

Ideally, you’d want to be able to write literals in your language’s
natural encoding.  You could then edit Python source code with your
favorite editor which would display the accented characters naturally,
and have the right characters used at runtime.

Python supports writing source code in UTF-8 by default, but you can use
almost any encoding if you declare the encoding being used.  This is
done by including a special comment as either the first or second line
of the source file:

     #!/usr/bin/env python
     # -*- coding: latin-1 -*-

     u = 'abcdé'
     print(ord(u[-1]))

The syntax is inspired by Emacs’s notation for specifying variables
local to a file.  Emacs supports many different variables, but Python
only supports “coding”.  The ‘-*-’ symbols indicate to Emacs that the
comment is special; they have no significance to Python but are a
convention.  Python looks for ‘coding: name’ or ‘coding=name’ in the
comment.

If you don’t include such a comment, the default encoding used will be
UTF-8 as already mentioned.  See also PEP 263(1) for more information.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0263/


File: python.info,  Node: Unicode Properties,  Next: Comparing Strings,  Prev: Unicode Literals in Python Source Code,  Up: Python’s Unicode Support

9.13.2.4 Unicode Properties
...........................

The Unicode specification includes a database of information about code
points.  For each defined code point, the information includes the
character’s name, its category, the numeric value if applicable (for
characters representing numeric concepts such as the Roman numerals,
fractions such as one-third and four-fifths, etc.).  There are also
display-related properties, such as how to use the code point in
bidirectional text.

The following program displays some information about several
characters, and prints the numeric value of one particular character:

     import unicodedata

     u = chr(233) + chr(0x0bf2) + chr(3972) + chr(6000) + chr(13231)

     for i, c in enumerate(u):
         print(i, '%04x' % ord(c), unicodedata.category(c), end=" ")
         print(unicodedata.name(c))

     # Get numeric value of second character
     print(unicodedata.numeric(u[1]))

When run, this prints:

     0 00e9 Ll LATIN SMALL LETTER E WITH ACUTE
     1 0bf2 No TAMIL NUMBER ONE THOUSAND
     2 0f84 Mn TIBETAN MARK HALANTA
     3 1770 Lo TAGBANWA LETTER SA
     4 33af So SQUARE RAD OVER S SQUARED
     1000.0

The category codes are abbreviations describing the nature of the
character.  These are grouped into categories such as «Letter»,
«Number», «Punctuation», or «Symbol», which in turn are broken up into
subcategories.  To take the codes from the above output, ‘'Ll'’ means
“Letter, lowercase”, ‘'No'’ means «Number, other», ‘'Mn'’ is «Mark,
nonspacing», and ‘'So'’ is «Symbol, other».  See the General Category
Values section of the Unicode Character Database documentation(1) for a
list of category codes.

   ---------- Footnotes ----------

   (1) https://www.unicode.org/reports/tr44/#General_Category_Values


File: python.info,  Node: Comparing Strings,  Next: Unicode Regular Expressions,  Prev: Unicode Properties,  Up: Python’s Unicode Support

9.13.2.5 Comparing Strings
..........................

Unicode adds some complication to comparing strings, because the same
set of characters can be represented by different sequences of code
points.  For example, a letter like “ê” can be represented as a single
code point U+00EA, or as U+0065 U+0302, which is the code point for “e”
followed by a code point for “COMBINING CIRCUMFLEX ACCENT”.  These will
produce the same output when printed, but one is a string of length 1
and the other is of length 2.

One tool for a case-insensitive comparison is the *note casefold(): fd8.
string method that converts a string to a case-insensitive form
following an algorithm described by the Unicode Standard.  This
algorithm has special handling for characters such as the German letter
“ß” (code point U+00DF), which becomes the pair of lowercase letters
“ss”.

     >>> street = 'Gürzenichstraße'
     >>> street.casefold()
     'gürzenichstrasse'

A second tool is the *note unicodedata: 10b. module’s *note normalize():
8e5. function that converts strings to one of several normal forms,
where letters followed by a combining character are replaced with single
characters.  *note normalize(): 8e5. can be used to perform string
comparisons that won’t falsely report inequality if two strings use
combining characters differently:

     import unicodedata

     def compare_strs(s1, s2):
         def NFD(s):
             return unicodedata.normalize('NFD', s)

         return NFD(s1) == NFD(s2)

     single_char = 'ê'
     multiple_chars = '\N{LATIN SMALL LETTER E}\N{COMBINING CIRCUMFLEX ACCENT}'
     print('length of first string=', len(single_char))
     print('length of second string=', len(multiple_chars))
     print(compare_strs(single_char, multiple_chars))

When run, this outputs:

     $ python compare-strs.py
     length of first string= 1
     length of second string= 2
     True

The first argument to the *note normalize(): 8e5. function is a string
giving the desired normalization form, which can be one of “NFC”,
“NFKC”, “NFD”, and “NFKD”.

The Unicode Standard also specifies how to do caseless comparisons:

     import unicodedata

     def compare_caseless(s1, s2):
         def NFD(s):
             return unicodedata.normalize('NFD', s)

         return NFD(NFD(s1).casefold()) == NFD(NFD(s2).casefold())

     # Example usage
     single_char = 'ê'
     multiple_chars = '\N{LATIN CAPITAL LETTER E}\N{COMBINING CIRCUMFLEX ACCENT}'

     print(compare_caseless(single_char, multiple_chars))

This will print ‘True’.  (Why is ‘NFD()’ invoked twice?  Because there
are a few characters that make *note casefold(): fd8. return a
non-normalized string, so the result needs to be normalized again.  See
section 3.13 of the Unicode Standard for a discussion and an example.)


File: python.info,  Node: Unicode Regular Expressions,  Next: References<4>,  Prev: Comparing Strings,  Up: Python’s Unicode Support

9.13.2.6 Unicode Regular Expressions
....................................

The regular expressions supported by the *note re: be. module can be
provided either as bytes or strings.  Some of the special character
sequences such as ‘\d’ and ‘\w’ have different meanings depending on
whether the pattern is supplied as bytes or a string.  For example, ‘\d’
will match the characters ‘[0-9]’ in bytes but in strings will match any
character that’s in the ‘'Nd'’ category.

The string in this example has the number 57 written in both Thai and
Arabic numerals:

     import re
     p = re.compile(r'\d+')

     s = "Over \u0e55\u0e57 57 flavours"
     m = p.search(s)
     print(repr(m.group()))

When executed, ‘\d+’ will match the Thai numerals and print them out.
If you supply the *note re.ASCII: 83f. flag to *note compile(): dd0,
‘\d+’ will match the substring «57» instead.

Similarly, ‘\w’ matches a wide variety of Unicode characters but only
‘[a-zA-Z0-9_]’ in bytes or if *note re.ASCII: 83f. is supplied, and ‘\s’
will match either Unicode whitespace characters or ‘[ \t\n\r\f\v]’.


File: python.info,  Node: References<4>,  Prev: Unicode Regular Expressions,  Up: Python’s Unicode Support

9.13.2.7 References
...................

Some good alternative discussions of Python’s Unicode support are:

   * Processing Text Files in Python 3(1), by Nick Coghlan.

   * Pragmatic Unicode(2), a PyCon 2012 presentation by Ned Batchelder.

The *note str: 169. type is described in the Python library reference at
*note Tipo Sequenza di Testo — str: 1fc9.

The documentation for the *note unicodedata: 10b. module.

The documentation for the *note codecs: 1c. module.

Marc-André Lemburg gave a presentation titled "Python and Unicode" (PDF
slides)(3) at EuroPython 2002.  The slides are an excellent overview of
the design of Python 2’s Unicode features (where the Unicode string type
is called ‘unicode’ and literals start with ‘u’).

   ---------- Footnotes ----------

   (1) 
https://python-notes.curiousefficiency.org/en/latest/python3/text_file_processing.html

   (2) https://nedbatchelder.com/text/unipain.html

   (3) https://downloads.egenix.com/python/Unicode-EPC2002-Talk.pdf


File: python.info,  Node: Reading and Writing Unicode Data,  Next: Acknowledgements<10>,  Prev: Python’s Unicode Support,  Up: Unicode HOWTO

9.13.3 Reading and Writing Unicode Data
---------------------------------------

Once you’ve written some code that works with Unicode data, the next
problem is input/output.  How do you get Unicode strings into your
program, and how do you convert Unicode into a form suitable for storage
or transmission?

It’s possible that you may not need to do anything depending on your
input sources and output destinations; you should check whether the
libraries used in your application support Unicode natively.  XML
parsers often return Unicode data, for example.  Many relational
databases also support Unicode-valued columns and can return Unicode
values from an SQL query.

Unicode data is usually converted to a particular encoding before it
gets written to disk or sent over a socket.  It’s possible to do all the
work yourself: open a file, read an 8-bit bytes object from it, and
convert the bytes with ‘bytes.decode(encoding)’.  However, the manual
approach is not recommended.

One problem is the multi-byte nature of encodings; one Unicode character
can be represented by several bytes.  If you want to read the file in
arbitrary-sized chunks (say, 1024 or 4096 bytes), you need to write
error-handling code to catch the case where only part of the bytes
encoding a single Unicode character are read at the end of a chunk.  One
solution would be to read the entire file into memory and then perform
the decoding, but that prevents you from working with files that are
extremely large; if you need to read a 2 GiB file, you need 2 GiB of
RAM.  (More, really, since for at least a moment you’d need to have both
the encoded string and its Unicode version in memory.)

The solution would be to use the low-level decoding interface to catch
the case of partial coding sequences.  The work of implementing this has
already been done for you: the built-in *note open(): 316. function can
return a file-like object that assumes the file’s contents are in a
specified encoding and accepts Unicode parameters for methods such as
*note read(): 2056. and *note write(): 2045.  This works through *note
open(): 316.'s 'encoding' and 'errors' parameters which are interpreted
just like those in *note str.encode(): ad4. and *note bytes.decode():
ad5.

Reading Unicode from a file is therefore simple:

     with open('unicode.txt', encoding='utf-8') as f:
         for line in f:
             print(repr(line))

It’s also possible to open files in update mode, allowing both reading
and writing:

     with open('test', encoding='utf-8', mode='w+') as f:
         f.write('\u4500 blah blah blah\n')
         f.seek(0)
         print(repr(f.readline()[:1]))

The Unicode character ‘U+FEFF’ is used as a byte-order mark (BOM), and
is often written as the first character of a file in order to assist
with autodetection of the file’s byte ordering.  Some encodings, such as
UTF-16, expect a BOM to be present at the start of a file; when such an
encoding is used, the BOM will be automatically written as the first
character and will be silently dropped when the file is read.  There are
variants of these encodings, such as “utf-16-le” and “utf-16-be” for
little-endian and big-endian encodings, that specify one particular byte
ordering and don’t skip the BOM.

In some areas, it is also convention to use a «BOM» at the start of
UTF-8 encoded files; the name is misleading since UTF-8 is not
byte-order dependent.  The mark simply announces that the file is
encoded in UTF-8.  For reading such files, use the “utf-8-sig” codec to
automatically skip the mark if present.

* Menu:

* Unicode filenames::
* Tips for Writing Unicode-aware Programs::
* References: References<5>.


File: python.info,  Node: Unicode filenames,  Next: Tips for Writing Unicode-aware Programs,  Up: Reading and Writing Unicode Data

9.13.3.1 Unicode filenames
..........................

Most of the operating systems in common use today support filenames that
contain arbitrary Unicode characters.  Usually this is implemented by
converting the Unicode string into some encoding that varies depending
on the system.  Today Python is converging on using UTF-8: Python on
MacOS has used UTF-8 for several versions, and Python 3.6 switched to
using UTF-8 on Windows as well.  On Unix systems, there will only be a
*note filesystem encoding: 75e.  if you’ve set the ‘LANG’ or ‘LC_CTYPE’
environment variables; if you haven’t, the default encoding is again
UTF-8.

The *note sys.getfilesystemencoding(): e55. function returns the
encoding to use on your current system, in case you want to do the
encoding manually, but there’s not much reason to bother.  When opening
a file for reading or writing, you can usually just provide the Unicode
string as the filename, and it will be automatically converted to the
right encoding for you:

     filename = 'filename\u4500abc'
     with open(filename, 'w') as f:
         f.write('blah\n')

Functions in the *note os: a5. module such as *note os.stat(): 26d. will
also accept Unicode filenames.

The *note os.listdir(): 1302. function returns filenames, which raises
an issue: should it return the Unicode version of filenames, or should
it return bytes containing the encoded versions?  *note os.listdir():
1302. can do both, depending on whether you provided the directory path
as bytes or a Unicode string.  If you pass a Unicode string as the path,
filenames will be decoded using the filesystem’s encoding and a list of
Unicode strings will be returned, while passing a byte path will return
the filenames as bytes.  For example, assuming the default *note
filesystem encoding: 75e. is UTF-8, running the following program:

     fn = 'filename\u4500abc'
     f = open(fn, 'w')
     f.close()

     import os
     print(os.listdir(b'.'))
     print(os.listdir('.'))

will produce the following output:

     $ python listdir-test.py
     [b'filename\xe4\x94\x80abc', ...]
     ['filename\u4500abc', ...]

The first list contains UTF-8-encoded filenames, and the second list
contains the Unicode versions.

Note that on most occasions, you should can just stick with using
Unicode with these APIs.  The bytes APIs should only be used on systems
where undecodable file names can be present; that’s pretty much only
Unix systems now.


File: python.info,  Node: Tips for Writing Unicode-aware Programs,  Next: References<5>,  Prev: Unicode filenames,  Up: Reading and Writing Unicode Data

9.13.3.2 Tips for Writing Unicode-aware Programs
................................................

This section provides some suggestions on writing software that deals
with Unicode.

The most important tip is:

     Software should only work with Unicode strings internally, decoding
     the input data as soon as possible and encoding the output only at
     the end.

If you attempt to write processing functions that accept both Unicode
and byte strings, you will find your program vulnerable to bugs wherever
you combine the two different kinds of strings.  There is no automatic
encoding or decoding: if you do e.g.  ‘str + bytes’, a *note TypeError:
198. will be raised.

When using data coming from a web browser or some other untrusted
source, a common technique is to check for illegal characters in a
string before using the string in a generated command line or storing it
in a database.  If you’re doing this, be careful to check the decoded
string, not the encoded bytes data; some encodings may have interesting
properties, such as not being bijective or not being fully
ASCII-compatible.  This is especially true if the input data also
specifies the encoding, since the attacker can then choose a clever way
to hide malicious text in the encoded bytestream.

* Menu:

* Converting Between File Encodings::
* Files in an Unknown Encoding::


File: python.info,  Node: Converting Between File Encodings,  Next: Files in an Unknown Encoding,  Up: Tips for Writing Unicode-aware Programs

9.13.3.3 Converting Between File Encodings
..........................................

The *note StreamRecoder: 1dbc. class can transparently convert between
encodings, taking a stream that returns data in encoding #1 and behaving
like a stream returning data in encoding #2.

For example, if you have an input file 'f' that’s in Latin-1, you can
wrap it with a *note StreamRecoder: 1dbc. to return bytes encoded in
UTF-8:

     new_f = codecs.StreamRecoder(f,
         # en/decoder: used by read() to encode its results and
         # by write() to decode its input.
         codecs.getencoder('utf-8'), codecs.getdecoder('utf-8'),

         # reader/writer: used to read and write to the stream.
         codecs.getreader('latin-1'), codecs.getwriter('latin-1') )


File: python.info,  Node: Files in an Unknown Encoding,  Prev: Converting Between File Encodings,  Up: Tips for Writing Unicode-aware Programs

9.13.3.4 Files in an Unknown Encoding
.....................................

What can you do if you need to make a change to a file, but don’t know
the file’s encoding?  If you know the encoding is ASCII-compatible and
only want to examine or modify the ASCII parts, you can open the file
with the ‘surrogateescape’ error handler:

     with open(fname, 'r', encoding="ascii", errors="surrogateescape") as f:
         data = f.read()

     # make changes to the string 'data'

     with open(fname + '.new', 'w',
               encoding="ascii", errors="surrogateescape") as f:
         f.write(data)

The ‘surrogateescape’ error handler will decode any non-ASCII bytes as
code points in a special range running from U+DC80 to U+DCFF. These code
points will then turn back into the same bytes when the
‘surrogateescape’ error handler is used to encode the data and write it
back out.


File: python.info,  Node: References<5>,  Prev: Tips for Writing Unicode-aware Programs,  Up: Reading and Writing Unicode Data

9.13.3.5 References
...................

One section of Mastering Python 3 Input/Output(1), a PyCon 2010 talk by
David Beazley, discusses text processing and binary data handling.

The PDF slides for Marc-André Lemburg's presentation "Writing
Unicode-aware Applications in Python"(2) discuss questions of character
encodings as well as how to internationalize and localize an
application.  These slides cover Python 2.x only.

The Guts of Unicode in Python(3) is a PyCon 2013 talk by Benjamin
Peterson that discusses the internal Unicode representation in Python
3.3.

   ---------- Footnotes ----------

   (1) https://pyvideo.org/video/289/pycon-2010-mastering-python-3-i-o

   (2) 
https://downloads.egenix.com/python/LSM2005-Developing-Unicode-aware-applications-in-Python.pdf

   (3) https://pyvideo.org/video/1768/the-guts-of-unicode-in-python


File: python.info,  Node: Acknowledgements<10>,  Prev: Reading and Writing Unicode Data,  Up: Unicode HOWTO

9.13.4 Acknowledgements
-----------------------

The initial draft of this document was written by Andrew Kuchling.  It
has since been revised further by Alexander Belopolsky, Georg Brandl,
Andrew Kuchling, and Ezio Melotti.

Thanks to the following people who have noted errors or offered
suggestions on this article: Éric Araujo, Nicholas Bastin, Nick Coghlan,
Marius Gedminas, Kent Johnson, Ken Krugler, Marc-André Lemburg, Martin
von Löwis, Terry J. Reedy, Serhiy Storchaka, Eryk Sun, Chad Whitacre,
Graham Wideman.


File: python.info,  Node: HOWTO Fetch Internet Resources Using The urllib Package,  Next: An introduction to the ipaddress module,  Prev: Unicode HOWTO,  Up: Python HOWTOs

9.14 HOWTO Fetch Internet Resources Using The urllib Package
============================================================


Author: Michael Foord(1)

* Menu:

* Introduction: Introduction<16>.
* Fetching URLs::
* Handling Exceptions::
* info and geturl::
* Openers and Handlers::
* Basic Authentication::
* Proxies::
* Sockets and Layers::
* Footnotes::

   ---------- Footnotes ----------

   (1) https://agileabstractions.com/


File: python.info,  Node: Introduction<16>,  Next: Fetching URLs,  Up: HOWTO Fetch Internet Resources Using The urllib Package

9.14.1 Introduction
-------------------

Related Articles
................

You may also find useful the following article on fetching web resources
with Python:

   * Basic Authentication(1)

          A tutorial on 'Basic Authentication', with examples in Python.

'urllib.request' is a Python module for fetching URLs (Uniform Resource
Locators).  It offers a very simple interface, in the form of the
'urlopen' function.  This is capable of fetching URLs using a variety of
different protocols.  It also offers a slightly more complex interface
for handling common situations - like basic authentication, cookies,
proxies and so on.  These are provided by objects called handlers and
openers.

urllib.request supports fetching URLs for many «URL schemes» (identified
by the string before the ‘":"’ in URL - for example ‘"ftp"’ is the URL
scheme of ‘"ftp://python.org/"’) using their associated network
protocols (e.g.  FTP, HTTP). This tutorial focuses on the most common
case, HTTP.

For straightforward situations 'urlopen' is very easy to use.  But as
soon as you encounter errors or non-trivial cases when opening HTTP
URLs, you will need some understanding of the HyperText Transfer
Protocol.  The most comprehensive and authoritative reference to HTTP is
RFC 2616(2).  This is a technical document and not intended to be easy
to read.  This HOWTO aims to illustrate using 'urllib', with enough
detail about HTTP to help you through.  It is not intended to replace
the *note urllib.request: 111. docs, but is supplementary to them.

   ---------- Footnotes ----------

   (1) 
https://web.archive.org/web/20201215133350/http://www.voidspace.org.uk/python/articles/authentication.shtml

   (2) https://datatracker.ietf.org/doc/html/rfc2616.html


File: python.info,  Node: Fetching URLs,  Next: Handling Exceptions,  Prev: Introduction<16>,  Up: HOWTO Fetch Internet Resources Using The urllib Package

9.14.2 Fetching URLs
--------------------

The simplest way to use urllib.request is as follows:

     import urllib.request
     with urllib.request.urlopen('http://python.org/') as response:
        html = response.read()

If you wish to retrieve a resource via URL and store it in a temporary
location, you can do so via the *note shutil.copyfileobj(): c54. and
*note tempfile.NamedTemporaryFile(): 6ee. functions:

     import shutil
     import tempfile
     import urllib.request

     with urllib.request.urlopen('http://python.org/') as response:
         with tempfile.NamedTemporaryFile(delete=False) as tmp_file:
             shutil.copyfileobj(response, tmp_file)

     with open(tmp_file.name) as html:
         pass

Many uses of urllib will be that simple (note that instead of an “http:”
URL we could have used a URL starting with “ftp:”, “file:”, etc.).
However, it’s the purpose of this tutorial to explain the more
complicated cases, concentrating on HTTP.

HTTP is based on requests and responses - the client makes requests and
servers send responses.  urllib.request mirrors this with a ‘Request’
object which represents the HTTP request you are making.  In its
simplest form you create a Request object that specifies the URL you
want to fetch.  Calling ‘urlopen’ with this Request object returns a
response object for the URL requested.  This response is a file-like
object, which means you can for example call ‘.read()’ on the response:

     import urllib.request

     req = urllib.request.Request('http://python.org/')
     with urllib.request.urlopen(req) as response:
        the_page = response.read()

Note that urllib.request makes use of the same Request interface to
handle all URL schemes.  For example, you can make an FTP request like
so:

     req = urllib.request.Request('ftp://example.com/')

In the case of HTTP, there are two extra things that Request objects
allow you to do: First, you can pass data to be sent to the server.
Second, you can pass extra information («metadata») 'about' the data or
about the request itself, to the server - this information is sent as
HTTP «headers».  Let’s look at each of these in turn.

* Menu:

* Data::
* Headers::


File: python.info,  Node: Data,  Next: Headers,  Up: Fetching URLs

9.14.2.1 Data
.............

Sometimes you want to send data to a URL (often the URL will refer to a
CGI (Common Gateway Interface) script or other web application).  With
HTTP, this is often done using what’s known as a 'POST' request.  This
is often what your browser does when you submit a HTML form that you
filled in on the web.  Not all POSTs have to come from forms: you can
use a POST to transmit arbitrary data to your own application.  In the
common case of HTML forms, the data needs to be encoded in a standard
way, and then passed to the Request object as the ‘data’ argument.  The
encoding is done using a function from the *note urllib.parse: 110.
library.

     import urllib.parse
     import urllib.request

     url = 'http://www.someserver.com/cgi-bin/register.cgi'
     values = {'name' : 'Michael Foord',
               'location' : 'Northampton',
               'language' : 'Python' }

     data = urllib.parse.urlencode(values)
     data = data.encode('ascii') # data should be bytes
     req = urllib.request.Request(url, data)
     with urllib.request.urlopen(req) as response:
        the_page = response.read()

Note that other encodings are sometimes required (e.g.  for file upload
from HTML forms - see HTML Specification, Form Submission(1) for more
details).

If you do not pass the ‘data’ argument, urllib uses a 'GET' request.
One way in which GET and POST requests differ is that POST requests
often have «side-effects»: they change the state of the system in some
way (for example by placing an order with the website for a
hundredweight of tinned spam to be delivered to your door).  Though the
HTTP standard makes it clear that POSTs are intended to 'always' cause
side-effects, and GET requests 'never' to cause side-effects, nothing
prevents a GET request from having side-effects, nor a POST requests
from having no side-effects.  Data can also be passed in an HTTP GET
request by encoding it in the URL itself.

This is done as follows:

     >>> import urllib.request
     >>> import urllib.parse
     >>> data = {}
     >>> data['name'] = 'Somebody Here'
     >>> data['location'] = 'Northampton'
     >>> data['language'] = 'Python'
     >>> url_values = urllib.parse.urlencode(data)
     >>> print(url_values)  # The order may differ from below.
     name=Somebody+Here&language=Python&location=Northampton
     >>> url = 'http://www.example.com/example.cgi'
     >>> full_url = url + '?' + url_values
     >>> data = urllib.request.urlopen(full_url)

Notice that the full URL is created by adding a ‘?’ to the URL, followed
by the encoded values.

   ---------- Footnotes ----------

   (1) https://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13


File: python.info,  Node: Headers,  Prev: Data,  Up: Fetching URLs

9.14.2.2 Headers
................

We’ll discuss here one particular HTTP header, to illustrate how to add
headers to your HTTP request.

Some websites (1) dislike being browsed by programs, or send different
versions to different browsers (2).  By default urllib identifies itself
as ‘Python-urllib/x.y’ (where ‘x’ and ‘y’ are the major and minor
version numbers of the Python release, e.g.  ‘Python-urllib/2.5’), which
may confuse the site, or just plain not work.  The way a browser
identifies itself is through the ‘User-Agent’ header (3).  When you
create a Request object you can pass a dictionary of headers in.  The
following example makes the same request as above, but identifies itself
as a version of Internet Explorer (4).

     import urllib.parse
     import urllib.request

     url = 'http://www.someserver.com/cgi-bin/register.cgi'
     user_agent = 'Mozilla/5.0 (Windows NT 6.1; Win64; x64)'
     values = {'name': 'Michael Foord',
               'location': 'Northampton',
               'language': 'Python' }
     headers = {'User-Agent': user_agent}

     data = urllib.parse.urlencode(values)
     data = data.encode('ascii')
     req = urllib.request.Request(url, data, headers)
     with urllib.request.urlopen(req) as response:
        the_page = response.read()

The response also has two useful methods.  See the section on *note info
and geturl: 57d8. which comes after we have a look at what happens when
things go wrong.

   ---------- Footnotes ----------

   (1) Google for example.

   (2) Browser sniffing is a very bad practice for website design -
building sites using web standards is much more sensible.  Unfortunately
a lot of sites still send different versions to different browsers.

   (3) The user agent for MSIE 6 is '“Mozilla/4.0 (compatible; MSIE 6.0;
Windows NT 5.1; SV1; .NET CLR 1.1.4322)”'

   (4) For details of more HTTP request headers, see Quick Reference to
HTTP Headers (https://jkorpela.fi/http.html).


File: python.info,  Node: Handling Exceptions,  Next: info and geturl,  Prev: Fetching URLs,  Up: HOWTO Fetch Internet Resources Using The urllib Package

9.14.3 Handling Exceptions
--------------------------

'urlopen' raises *note URLError: 2be. when it cannot handle a response
(though as usual with Python APIs, built-in exceptions such as *note
ValueError: 2ec, *note TypeError: 198. etc.  may also be raised).

*note HTTPError: 11e0. is the subclass of *note URLError: 2be. raised in
the specific case of HTTP URLs.

The exception classes are exported from the *note urllib.error: 10f.
module.

* Menu:

* URLError::
* HTTPError::
* Wrapping it Up::


File: python.info,  Node: URLError,  Next: HTTPError,  Up: Handling Exceptions

9.14.3.1 URLError
.................

Often, URLError is raised because there is no network connection (no
route to the specified server), or the specified server doesn’t exist.
In this case, the exception raised will have a “reason” attribute, which
is a tuple containing an error code and a text error message.

e.g.

     >>> req = urllib.request.Request('http://www.pretend_server.org')
     >>> try: urllib.request.urlopen(req)
     ... except urllib.error.URLError as e:
     ...     print(e.reason)
     ...
     (4, 'getaddrinfo failed')


File: python.info,  Node: HTTPError,  Next: Wrapping it Up,  Prev: URLError,  Up: Handling Exceptions

9.14.3.2 HTTPError
..................

Every HTTP response from the server contains a numeric «status code».
Sometimes the status code indicates that the server is unable to fulfil
the request.  The default handlers will handle some of these responses
for you (for example, if the response is a «redirection» that requests
the client fetch the document from a different URL, urllib will handle
that for you).  For those it can’t handle, urlopen will raise an *note
HTTPError: 11e0.  Typical errors include “404” (page not found), “403”
(request forbidden), and “401” (authentication required).

See section 10 of RFC 2616(1) for a reference on all the HTTP error
codes.

The *note HTTPError: 11e0. instance raised will have an integer “code”
attribute, which corresponds to the error sent by the server.

* Menu:

* Error Codes::

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2616.html


File: python.info,  Node: Error Codes,  Up: HTTPError

9.14.3.3 Error Codes
....................

Because the default handlers handle redirects (codes in the 300 range),
and codes in the 100–299 range indicate success, you will usually only
see error codes in the 400–599 range.

*note http.server.BaseHTTPRequestHandler.responses: 3f96. is a useful
dictionary of response codes that shows all the response codes used by
RFC 2616(1).  An excerpt from the dictionary is shown below

     responses = {
         ...
         <HTTPStatus.OK: 200>: ('OK', 'Request fulfilled, document follows'),
         ...
         <HTTPStatus.FORBIDDEN: 403>: ('Forbidden',
                                       'Request forbidden -- authorization will '
                                       'not help'),
         <HTTPStatus.NOT_FOUND: 404>: ('Not Found',
                                       'Nothing matches the given URI'),
         ...
         <HTTPStatus.IM_A_TEAPOT: 418>: ("I'm a Teapot",
                                         'Server refuses to brew coffee because '
                                         'it is a teapot'),
         ...
         <HTTPStatus.SERVICE_UNAVAILABLE: 503>: ('Service Unavailable',
                                                 'The server cannot process the '
                                                 'request due to a high load'),
         ...
         }

When an error is raised the server responds by returning an HTTP error
code 'and' an error page.  You can use the *note HTTPError: 11e0.
instance as a response on the page returned.  This means that as well as
the code attribute, it also has read, geturl, and info, methods as
returned by the ‘urllib.response’ module:

     >>> req = urllib.request.Request('http://www.python.org/fish.html')
     >>> try:
     ...     urllib.request.urlopen(req)
     ... except urllib.error.HTTPError as e:
     ...     print(e.code)
     ...     print(e.read())
     ...
     404
     b'<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
       "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">\n\n\n<html
       ...
       <title>Page Not Found</title>\n
       ...

   ---------- Footnotes ----------

   (1) https://datatracker.ietf.org/doc/html/rfc2616.html


File: python.info,  Node: Wrapping it Up,  Prev: HTTPError,  Up: Handling Exceptions

9.14.3.4 Wrapping it Up
.......................

So if you want to be prepared for *note HTTPError: 11e0. 'or' *note
URLError: 2be. there are two basic approaches.  I prefer the second
approach.

* Menu:

* Number 1::
* Number 2::


File: python.info,  Node: Number 1,  Next: Number 2,  Up: Wrapping it Up

9.14.3.5 Number 1
.................

     from urllib.request import Request, urlopen
     from urllib.error import URLError, HTTPError
     req = Request(someurl)
     try:
         response = urlopen(req)
     except HTTPError as e:
         print('The server couldn\'t fulfill the request.')
         print('Error code: ', e.code)
     except URLError as e:
         print('We failed to reach a server.')
         print('Reason: ', e.reason)
     else:
         # everything is fine

     Nota: The ‘except HTTPError’ 'must' come first, otherwise ‘except
     URLError’ will 'also' catch an *note HTTPError: 11e0.


File: python.info,  Node: Number 2,  Prev: Number 1,  Up: Wrapping it Up

9.14.3.6 Number 2
.................

     from urllib.request import Request, urlopen
     from urllib.error import URLError
     req = Request(someurl)
     try:
         response = urlopen(req)
     except URLError as e:
         if hasattr(e, 'reason'):
             print('We failed to reach a server.')
             print('Reason: ', e.reason)
         elif hasattr(e, 'code'):
             print('The server couldn\'t fulfill the request.')
             print('Error code: ', e.code)
     else:
         # everything is fine


File: python.info,  Node: info and geturl,  Next: Openers and Handlers,  Prev: Handling Exceptions,  Up: HOWTO Fetch Internet Resources Using The urllib Package

9.14.4 info and geturl
----------------------

The response returned by urlopen (or the *note HTTPError: 11e0.
instance) has two useful methods ‘info()’ and ‘geturl()’ and is defined
in the module *note urllib.response: 112.

   * 'geturl' - this returns the real URL of the page fetched.  This is
     useful because ‘urlopen’ (or the opener object used) may have
     followed a redirect.  The URL of the page fetched may not be the
     same as the URL requested.

   * 'info' - this returns a dictionary-like object that describes the
     page fetched, particularly the headers sent by the server.  It is
     currently an *note http.client.HTTPMessage: 3faf. instance.

Typical headers include “Content-length”, “Content-type”, and so on.
See the Quick Reference to HTTP Headers(1) for a useful listing of HTTP
headers with brief explanations of their meaning and use.

   ---------- Footnotes ----------

   (1) https://jkorpela.fi/http.html


File: python.info,  Node: Openers and Handlers,  Next: Basic Authentication,  Prev: info and geturl,  Up: HOWTO Fetch Internet Resources Using The urllib Package

9.14.5 Openers and Handlers
---------------------------

When you fetch a URL you use an opener (an instance of the perhaps
confusingly named *note urllib.request.OpenerDirector: 3eff.).  Normally
we have been using the default opener - via ‘urlopen’ - but you can
create custom openers.  Openers use handlers.  All the «heavy lifting»
is done by the handlers.  Each handler knows how to open URLs for a
particular URL scheme (http, ftp, etc.), or how to handle an aspect of
URL opening, for example HTTP redirections or HTTP cookies.

You will want to create openers if you want to fetch URLs with specific
handlers installed, for example to get an opener that handles cookies,
or to get an opener that does not handle redirections.

To create an opener, instantiate an ‘OpenerDirector’, and then call
‘.add_handler(some_handler_instance)’ repeatedly.

Alternatively, you can use ‘build_opener’, which is a convenience
function for creating opener objects with a single function call.
‘build_opener’ adds several handlers by default, but provides a quick
way to add more and/or override the default handlers.

Other sorts of handlers you might want to can handle proxies,
authentication, and other common but slightly specialised situations.

‘install_opener’ can be used to make an ‘opener’ object the (global)
default opener.  This means that calls to ‘urlopen’ will use the opener
you have installed.

Opener objects have an ‘open’ method, which can be called directly to
fetch urls in the same way as the ‘urlopen’ function: there’s no need to
call ‘install_opener’, except as a convenience.


File: python.info,  Node: Basic Authentication,  Next: Proxies,  Prev: Openers and Handlers,  Up: HOWTO Fetch Internet Resources Using The urllib Package

9.14.6 Basic Authentication
---------------------------

To illustrate creating and installing a handler we will use the
‘HTTPBasicAuthHandler’.  For a more detailed discussion of this subject
– including an explanation of how Basic Authentication works - see the
Basic Authentication Tutorial(1).

When authentication is required, the server sends a header (as well as
the 401 error code) requesting authentication.  This specifies the
authentication scheme and a “realm”.  The header looks like:
‘WWW-Authenticate: SCHEME realm="REALM"’.

e.g.

     WWW-Authenticate: Basic realm="cPanel Users"

The client should then retry the request with the appropriate name and
password for the realm included as a header in the request.  This is
“basic authentication”.  In order to simplify this process we can create
an instance of ‘HTTPBasicAuthHandler’ and an opener to use this handler.

The ‘HTTPBasicAuthHandler’ uses an object called a password manager to
handle the mapping of URLs and realms to passwords and usernames.  If
you know what the realm is (from the authentication header sent by the
server), then you can use a ‘HTTPPasswordMgr’.  Frequently one doesn’t
care what the realm is.  In that case, it is convenient to use
‘HTTPPasswordMgrWithDefaultRealm’.  This allows you to specify a default
username and password for a URL. This will be supplied in the absence of
you providing an alternative combination for a specific realm.  We
indicate this by providing ‘None’ as the realm argument to the
‘add_password’ method.

The top-level URL is the first URL that requires authentication.  URLs
«deeper» than the URL you pass to .add_password() will also match.

     # create a password manager
     password_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm()

     # Add the username and password.
     # If we knew the realm, we could use it instead of None.
     top_level_url = "http://example.com/foo/"
     password_mgr.add_password(None, top_level_url, username, password)

     handler = urllib.request.HTTPBasicAuthHandler(password_mgr)

     # create "opener" (OpenerDirector instance)
     opener = urllib.request.build_opener(handler)

     # use the opener to fetch a URL
     opener.open(a_url)

     # Install the opener.
     # Now all calls to urllib.request.urlopen use our opener.
     urllib.request.install_opener(opener)

     Nota: In the above example we only supplied our
     ‘HTTPBasicAuthHandler’ to ‘build_opener’.  By default openers have
     the handlers for normal situations – ‘ProxyHandler’ (if a proxy
     setting such as an ‘http_proxy’ environment variable is set),
     ‘UnknownHandler’, ‘HTTPHandler’, ‘HTTPDefaultErrorHandler’,
     ‘HTTPRedirectHandler’, ‘FTPHandler’, ‘FileHandler’, ‘DataHandler’,
     ‘HTTPErrorProcessor’.

‘top_level_url’ is in fact 'either' a full URL (including the “http:”
scheme component and the hostname and optionally the port number) e.g.
‘"http://example.com/"’ 'or' an «authority» (i.e.  the hostname,
optionally including the port number) e.g.  ‘"example.com"’ or
‘"example.com:8080"’ (the latter example includes a port number).  The
authority, if present, must NOT contain the «userinfo» component - for
example ‘"joe:password@example.com"’ is not correct.

   ---------- Footnotes ----------

   (1) 
https://web.archive.org/web/20201215133350/http://www.voidspace.org.uk/python/articles/authentication.shtml


File: python.info,  Node: Proxies,  Next: Sockets and Layers,  Prev: Basic Authentication,  Up: HOWTO Fetch Internet Resources Using The urllib Package

9.14.7 Proxies
--------------

'urllib' will auto-detect your proxy settings and use those.  This is
through the ‘ProxyHandler’, which is part of the normal handler chain
when a proxy setting is detected.  Normally that’s a good thing, but
there are occasions when it may not be helpful (1).  One way to do this
is to setup our own ‘ProxyHandler’, with no proxies defined.  This is
done using similar steps to setting up a *note Basic Authentication:
57e1. handler:

     >>> proxy_support = urllib.request.ProxyHandler({})
     >>> opener = urllib.request.build_opener(proxy_support)
     >>> urllib.request.install_opener(opener)

     Nota: Currently ‘urllib.request’ 'does not' support fetching of
     ‘https’ locations through a proxy.  However, this can be enabled by
     extending urllib.request as shown in the recipe (2).

     Nota: ‘HTTP_PROXY’ will be ignored if a variable ‘REQUEST_METHOD’
     is set; see the documentation on *note getproxies(): 3efc.

   ---------- Footnotes ----------

   (1) In my case I have to use a proxy to access the internet at work.
If you attempt to fetch 'localhost' URLs through this proxy it blocks
them.  IE is set to use the proxy, which urllib picks up on.  In order
to test scripts with a localhost server, I have to prevent urllib from
using the proxy.

   (2) urllib opener for SSL proxy (CONNECT method): ASPN Cookbook
Recipe
(https://code.activestate.com/recipes/456195-urrlib2-opener-for-ssl-proxy-connect-method/).


File: python.info,  Node: Sockets and Layers,  Next: Footnotes,  Prev: Proxies,  Up: HOWTO Fetch Internet Resources Using The urllib Package

9.14.8 Sockets and Layers
-------------------------

The Python support for fetching resources from the web is layered.
urllib uses the *note http.client: 73. library, which in turn uses the
socket library.

As of Python 2.3 you can specify how long a socket should wait for a
response before timing out.  This can be useful in applications which
have to fetch web pages.  By default the socket module has 'no timeout'
and can hang.  Currently, the socket timeout is not exposed at the
http.client or urllib.request levels.  However, you can set the default
timeout globally for all sockets using

     import socket
     import urllib.request

     # timeout in seconds
     timeout = 10
     socket.setdefaulttimeout(timeout)

     # this call to urllib.request.urlopen now uses the default timeout
     # we have set in the socket module
     req = urllib.request.Request('http://www.voidspace.org.uk')
     response = urllib.request.urlopen(req)

__________________________________________________________________


File: python.info,  Node: Footnotes,  Prev: Sockets and Layers,  Up: HOWTO Fetch Internet Resources Using The urllib Package

9.14.9 Footnotes
----------------

This document was reviewed and revised by John Lee.


File: python.info,  Node: An introduction to the ipaddress module,  Next: Instrumenting CPython with DTrace and SystemTap,  Prev: HOWTO Fetch Internet Resources Using The urllib Package,  Up: Python HOWTOs

9.15 An introduction to the ipaddress module
============================================


author: Peter Moody


author: Nick Coghlan

Overview
........

This document aims to provide a gentle introduction to the *note
ipaddress: 84. module.  It is aimed primarily at users that aren’t
already familiar with IP networking terminology, but may also be useful
to network engineers wanting an overview of how *note ipaddress: 84.
represents IP network addressing concepts.

* Menu:

* Creating Address/Network/Interface objects::
* Inspecting Address/Network/Interface Objects::
* Networks as lists of Addresses::
* Comparisons: Comparisons<3>.
* Using IP Addresses with other modules::
* Getting more detail when instance creation fails::


File: python.info,  Node: Creating Address/Network/Interface objects,  Next: Inspecting Address/Network/Interface Objects,  Up: An introduction to the ipaddress module

9.15.1 Creating Address/Network/Interface objects
-------------------------------------------------

Since *note ipaddress: 84. is a module for inspecting and manipulating
IP addresses, the first thing you’ll want to do is create some objects.
You can use *note ipaddress: 84. to create objects from strings and
integers.

* Menu:

* A Note on IP Versions::
* IP Host Addresses::
* Defining Networks::
* Host Interfaces::


File: python.info,  Node: A Note on IP Versions,  Next: IP Host Addresses,  Up: Creating Address/Network/Interface objects

9.15.1.1 A Note on IP Versions
..............................

For readers that aren’t particularly familiar with IP addressing, it’s
important to know that the Internet Protocol (IP) is currently in the
process of moving from version 4 of the protocol to version 6.  This
transition is occurring largely because version 4 of the protocol
doesn’t provide enough addresses to handle the needs of the whole world,
especially given the increasing number of devices with direct
connections to the internet.

Explaining the details of the differences between the two versions of
the protocol is beyond the scope of this introduction, but readers need
to at least be aware that these two versions exist, and it will
sometimes be necessary to force the use of one version or the other.


File: python.info,  Node: IP Host Addresses,  Next: Defining Networks,  Prev: A Note on IP Versions,  Up: Creating Address/Network/Interface objects

9.15.1.2 IP Host Addresses
..........................

Addresses, often referred to as «host addresses» are the most basic unit
when working with IP addressing.  The simplest way to create addresses
is to use the *note ipaddress.ip_address(): 41b1. factory function,
which automatically determines whether to create an IPv4 or IPv6 address
based on the passed in value:

     >>> ipaddress.ip_address('192.0.2.1')
     IPv4Address('192.0.2.1')
     >>> ipaddress.ip_address('2001:DB8::1')
     IPv6Address('2001:db8::1')

Addresses can also be created directly from integers.  Values that will
fit within 32 bits are assumed to be IPv4 addresses:

     >>> ipaddress.ip_address(3221225985)
     IPv4Address('192.0.2.1')
     >>> ipaddress.ip_address(42540766411282592856903984951653826561)
     IPv6Address('2001:db8::1')

To force the use of IPv4 or IPv6 addresses, the relevant classes can be
invoked directly.  This is particularly useful to force creation of IPv6
addresses for small integers:

     >>> ipaddress.ip_address(1)
     IPv4Address('0.0.0.1')
     >>> ipaddress.IPv4Address(1)
     IPv4Address('0.0.0.1')
     >>> ipaddress.IPv6Address(1)
     IPv6Address('::1')


File: python.info,  Node: Defining Networks,  Next: Host Interfaces,  Prev: IP Host Addresses,  Up: Creating Address/Network/Interface objects

9.15.1.3 Defining Networks
..........................

Host addresses are usually grouped together into IP networks, so *note
ipaddress: 84. provides a way to create, inspect and manipulate network
definitions.  IP network objects are constructed from strings that
define the range of host addresses that are part of that network.  The
simplest form for that information is a «network address/network prefix»
pair, where the prefix defines the number of leading bits that are
compared to determine whether or not an address is part of the network
and the network address defines the expected value of those bits.

As for addresses, a factory function is provided that determines the
correct IP version automatically:

     >>> ipaddress.ip_network('192.0.2.0/24')
     IPv4Network('192.0.2.0/24')
     >>> ipaddress.ip_network('2001:db8::0/96')
     IPv6Network('2001:db8::/96')

Network objects cannot have any host bits set.  The practical effect of
this is that ‘192.0.2.1/24’ does not describe a network.  Such
definitions are referred to as interface objects since the
ip-on-a-network notation is commonly used to describe network interfaces
of a computer on a given network and are described further in the next
section.

By default, attempting to create a network object with host bits set
will result in *note ValueError: 2ec. being raised.  To request that the
additional bits instead be coerced to zero, the flag ‘strict=False’ can
be passed to the constructor:

     >>> ipaddress.ip_network('192.0.2.1/24')
     Traceback (most recent call last):
        ...
     ValueError: 192.0.2.1/24 has host bits set
     >>> ipaddress.ip_network('192.0.2.1/24', strict=False)
     IPv4Network('192.0.2.0/24')

While the string form offers significantly more flexibility, networks
can also be defined with integers, just like host addresses.  In this
case, the network is considered to contain only the single address
identified by the integer, so the network prefix includes the entire
network address:

     >>> ipaddress.ip_network(3221225984)
     IPv4Network('192.0.2.0/32')
     >>> ipaddress.ip_network(42540766411282592856903984951653826560)
     IPv6Network('2001:db8::/128')

As with addresses, creation of a particular kind of network can be
forced by calling the class constructor directly instead of using the
factory function.


File: python.info,  Node: Host Interfaces,  Prev: Defining Networks,  Up: Creating Address/Network/Interface objects

9.15.1.4 Host Interfaces
........................

As mentioned just above, if you need to describe an address on a
particular network, neither the address nor the network classes are
sufficient.  Notation like ‘192.0.2.1/24’ is commonly used by network
engineers and the people who write tools for firewalls and routers as
shorthand for «the host ‘192.0.2.1’ on the network ‘192.0.2.0/24’»,
Accordingly, *note ipaddress: 84. provides a set of hybrid classes that
associate an address with a particular network.  The interface for
creation is identical to that for defining network objects, except that
the address portion isn’t constrained to being a network address.

     >>> ipaddress.ip_interface('192.0.2.1/24')
     IPv4Interface('192.0.2.1/24')
     >>> ipaddress.ip_interface('2001:db8::1/96')
     IPv6Interface('2001:db8::1/96')

Integer inputs are accepted (as with networks), and use of a particular
IP version can be forced by calling the relevant constructor directly.


File: python.info,  Node: Inspecting Address/Network/Interface Objects,  Next: Networks as lists of Addresses,  Prev: Creating Address/Network/Interface objects,  Up: An introduction to the ipaddress module

9.15.2 Inspecting Address/Network/Interface Objects
---------------------------------------------------

You’ve gone to the trouble of creating an
IPv(4|6)(Address|Network|Interface) object, so you probably want to get
information about it.  *note ipaddress: 84. tries to make doing this
easy and intuitive.

Extracting the IP version:

     >>> addr4 = ipaddress.ip_address('192.0.2.1')
     >>> addr6 = ipaddress.ip_address('2001:db8::1')
     >>> addr6.version
     6
     >>> addr4.version
     4

Obtaining the network from an interface:

     >>> host4 = ipaddress.ip_interface('192.0.2.1/24')
     >>> host4.network
     IPv4Network('192.0.2.0/24')
     >>> host6 = ipaddress.ip_interface('2001:db8::1/96')
     >>> host6.network
     IPv6Network('2001:db8::/96')

Finding out how many individual addresses are in a network:

     >>> net4 = ipaddress.ip_network('192.0.2.0/24')
     >>> net4.num_addresses
     256
     >>> net6 = ipaddress.ip_network('2001:db8::0/96')
     >>> net6.num_addresses
     4294967296

Iterating through the «usable» addresses on a network:

     >>> net4 = ipaddress.ip_network('192.0.2.0/24')
     >>> for x in net4.hosts():
     ...     print(x)
     192.0.2.1
     192.0.2.2
     192.0.2.3
     192.0.2.4
     ...
     192.0.2.252
     192.0.2.253
     192.0.2.254

Obtaining the netmask (i.e.  set bits corresponding to the network
prefix) or the hostmask (any bits that are not part of the netmask):

     >>> net4 = ipaddress.ip_network('192.0.2.0/24')
     >>> net4.netmask
     IPv4Address('255.255.255.0')
     >>> net4.hostmask
     IPv4Address('0.0.0.255')
     >>> net6 = ipaddress.ip_network('2001:db8::0/96')
     >>> net6.netmask
     IPv6Address('ffff:ffff:ffff:ffff:ffff:ffff::')
     >>> net6.hostmask
     IPv6Address('::ffff:ffff')

Exploding or compressing the address:

     >>> addr6.exploded
     '2001:0db8:0000:0000:0000:0000:0000:0001'
     >>> addr6.compressed
     '2001:db8::1'
     >>> net6.exploded
     '2001:0db8:0000:0000:0000:0000:0000:0000/96'
     >>> net6.compressed
     '2001:db8::/96'

While IPv4 doesn’t support explosion or compression, the associated
objects still provide the relevant properties so that version neutral
code can easily ensure the most concise or most verbose form is used for
IPv6 addresses while still correctly handling IPv4 addresses.


File: python.info,  Node: Networks as lists of Addresses,  Next: Comparisons<3>,  Prev: Inspecting Address/Network/Interface Objects,  Up: An introduction to the ipaddress module

9.15.3 Networks as lists of Addresses
-------------------------------------

It’s sometimes useful to treat networks as lists.  This means it is
possible to index them like this:

     >>> net4[1]
     IPv4Address('192.0.2.1')
     >>> net4[-1]
     IPv4Address('192.0.2.255')
     >>> net6[1]
     IPv6Address('2001:db8::1')
     >>> net6[-1]
     IPv6Address('2001:db8::ffff:ffff')

It also means that network objects lend themselves to using the list
membership test syntax like this:

     if address in network:
         # do something

Containment testing is done efficiently based on the network prefix:

     >>> addr4 = ipaddress.ip_address('192.0.2.1')
     >>> addr4 in ipaddress.ip_network('192.0.2.0/24')
     True
     >>> addr4 in ipaddress.ip_network('192.0.3.0/24')
     False


File: python.info,  Node: Comparisons<3>,  Next: Using IP Addresses with other modules,  Prev: Networks as lists of Addresses,  Up: An introduction to the ipaddress module

9.15.4 Comparisons
------------------

*note ipaddress: 84. provides some simple, hopefully intuitive ways to
compare objects, where it makes sense:

     >>> ipaddress.ip_address('192.0.2.1') < ipaddress.ip_address('192.0.2.2')
     True

A *note TypeError: 198. exception is raised if you try to compare
objects of different versions or different types.


File: python.info,  Node: Using IP Addresses with other modules,  Next: Getting more detail when instance creation fails,  Prev: Comparisons<3>,  Up: An introduction to the ipaddress module

9.15.5 Using IP Addresses with other modules
--------------------------------------------

Other modules that use IP addresses (such as *note socket: d1.) usually
won’t accept objects from this module directly.  Instead, they must be
coerced to an integer or string that the other module will accept:

     >>> addr4 = ipaddress.ip_address('192.0.2.1')
     >>> str(addr4)
     '192.0.2.1'
     >>> int(addr4)
     3221225985


File: python.info,  Node: Getting more detail when instance creation fails,  Prev: Using IP Addresses with other modules,  Up: An introduction to the ipaddress module

9.15.6 Getting more detail when instance creation fails
-------------------------------------------------------

When creating address/network/interface objects using the
version-agnostic factory functions, any errors will be reported as *note
ValueError: 2ec. with a generic error message that simply says the
passed in value was not recognized as an object of that type.  The lack
of a specific error is because it’s necessary to know whether the value
is 'supposed' to be IPv4 or IPv6 in order to provide more detail on why
it has been rejected.

To support use cases where it is useful to have access to this
additional detail, the individual class constructors actually raise the
*note ValueError: 2ec. subclasses *note ipaddress.AddressValueError:
41b6. and *note ipaddress.NetmaskValueError: 41d7. to indicate exactly
which part of the definition failed to parse correctly.

The error messages are significantly more detailed when using the class
constructors directly.  For example:

     >>> ipaddress.ip_address("192.168.0.256")
     Traceback (most recent call last):
       ...
     ValueError: '192.168.0.256' does not appear to be an IPv4 or IPv6 address
     >>> ipaddress.IPv4Address("192.168.0.256")
     Traceback (most recent call last):
       ...
     ipaddress.AddressValueError: Octet 256 (> 255) not permitted in '192.168.0.256'

     >>> ipaddress.ip_network("192.168.0.1/64")
     Traceback (most recent call last):
       ...
     ValueError: '192.168.0.1/64' does not appear to be an IPv4 or IPv6 network
     >>> ipaddress.IPv4Network("192.168.0.1/64")
     Traceback (most recent call last):
       ...
     ipaddress.NetmaskValueError: '64' is not a valid netmask

However, both of the module specific exceptions have *note ValueError:
2ec. as their parent class, so if you’re not concerned with the
particular type of error, you can still write code like the following:

     try:
         network = ipaddress.IPv4Network(address)
     except ValueError:
         print('address/netmask is invalid for IPv4:', address)


File: python.info,  Node: Instrumenting CPython with DTrace and SystemTap,  Next: Python support for the Linux perf profiler,  Prev: An introduction to the ipaddress module,  Up: Python HOWTOs

9.16 Instrumenting CPython with DTrace and SystemTap
====================================================


author: David Malcolm


author: Łukasz Langa

DTrace and SystemTap are monitoring tools, each providing a way to
inspect what the processes on a computer system are doing.  They both
use domain-specific languages allowing a user to write scripts which:

   - filter which processes are to be observed

   - gather data from the processes of interest

   - generate reports on the data

As of Python 3.6, CPython can be built with embedded «markers», also
known as «probes», that can be observed by a DTrace or SystemTap script,
making it easier to monitor what the CPython processes on a system are
doing.

'Dettaglio dell’implementazione di CPython:' DTrace markers are
implementation details of the CPython interpreter.  No guarantees are
made about probe compatibility between versions of CPython.  DTrace
scripts can stop working or work incorrectly without warning when
changing CPython versions.

* Menu:

* Enabling the static markers::
* Static DTrace probes::
* Static SystemTap markers::
* Available static markers::
* SystemTap Tapsets::
* Examples: Examples<40>.


File: python.info,  Node: Enabling the static markers,  Next: Static DTrace probes,  Up: Instrumenting CPython with DTrace and SystemTap

9.16.1 Enabling the static markers
----------------------------------

macOS comes with built-in support for DTrace.  On Linux, in order to
build CPython with the embedded markers for SystemTap, the SystemTap
development tools must be installed.

On a Linux machine, this can be done via:

     $ yum install systemtap-sdt-devel

or:

     $ sudo apt-get install systemtap-sdt-dev

CPython must then be *note configured with the -with-dtrace option:
2192.:

     checking for --with-dtrace... yes

On macOS, you can list available DTrace probes by running a Python
process in the background and listing all probes made available by the
Python provider:

     $ python3.6 -q &
     $ sudo dtrace -l -P python$!  # or: dtrace -l -m python3.6

        ID   PROVIDER            MODULE                          FUNCTION NAME
     29564 python18035        python3.6          _PyEval_EvalFrameDefault function-entry
     29565 python18035        python3.6             dtrace_function_entry function-entry
     29566 python18035        python3.6          _PyEval_EvalFrameDefault function-return
     29567 python18035        python3.6            dtrace_function_return function-return
     29568 python18035        python3.6                           collect gc-done
     29569 python18035        python3.6                           collect gc-start
     29570 python18035        python3.6          _PyEval_EvalFrameDefault line
     29571 python18035        python3.6                 maybe_dtrace_line line

On Linux, you can verify if the SystemTap static markers are present in
the built binary by seeing if it contains a «.note.stapsdt» section.

     $ readelf -S ./python | grep .note.stapsdt
     [30] .note.stapsdt        NOTE         0000000000000000 00308d78

If you’ve built Python as a shared library (with the *note
-enable-shared: a65. configure option), you need to look instead within
the shared library.  For example:

     $ readelf -S libpython3.3dm.so.1.0 | grep .note.stapsdt
     [29] .note.stapsdt        NOTE         0000000000000000 00365b68

Sufficiently modern readelf can print the metadata:

     $ readelf -n ./python

     Displaying notes found at file offset 0x00000254 with length 0x00000020:
         Owner                 Data size          Description
         GNU                  0x00000010          NT_GNU_ABI_TAG (ABI version tag)
             OS: Linux, ABI: 2.6.32

     Displaying notes found at file offset 0x00000274 with length 0x00000024:
         Owner                 Data size          Description
         GNU                  0x00000014          NT_GNU_BUILD_ID (unique build ID bitstring)
             Build ID: df924a2b08a7e89f6e11251d4602022977af2670

     Displaying notes found at file offset 0x002d6c30 with length 0x00000144:
         Owner                 Data size          Description
         stapsdt              0x00000031          NT_STAPSDT (SystemTap probe descriptors)
             Provider: python
             Name: gc__start
             Location: 0x00000000004371c3, Base: 0x0000000000630ce2, Semaphore: 0x00000000008d6bf6
             Arguments: -4@%ebx
         stapsdt              0x00000030          NT_STAPSDT (SystemTap probe descriptors)
             Provider: python
             Name: gc__done
             Location: 0x00000000004374e1, Base: 0x0000000000630ce2, Semaphore: 0x00000000008d6bf8
             Arguments: -8@%rax
         stapsdt              0x00000045          NT_STAPSDT (SystemTap probe descriptors)
             Provider: python
             Name: function__entry
             Location: 0x000000000053db6c, Base: 0x0000000000630ce2, Semaphore: 0x00000000008d6be8
             Arguments: 8@%rbp 8@%r12 -4@%eax
         stapsdt              0x00000046          NT_STAPSDT (SystemTap probe descriptors)
             Provider: python
             Name: function__return
             Location: 0x000000000053dba8, Base: 0x0000000000630ce2, Semaphore: 0x00000000008d6bea
             Arguments: 8@%rbp 8@%r12 -4@%eax

The above metadata contains information for SystemTap describing how it
can patch strategically placed machine code instructions to enable the
tracing hooks used by a SystemTap script.


File: python.info,  Node: Static DTrace probes,  Next: Static SystemTap markers,  Prev: Enabling the static markers,  Up: Instrumenting CPython with DTrace and SystemTap

9.16.2 Static DTrace probes
---------------------------

The following example DTrace script can be used to show the call/return
hierarchy of a Python script, only tracing within the invocation of a
function called «start».  In other words, import-time function
invocations are not going to be listed:

     self int indent;

     python$target:::function-entry
     /copyinstr(arg1) == "start"/
     {
             self->trace = 1;
     }

     python$target:::function-entry
     /self->trace/
     {
             printf("%d\t%*s:", timestamp, 15, probename);
             printf("%*s", self->indent, "");
             printf("%s:%s:%d\n", basename(copyinstr(arg0)), copyinstr(arg1), arg2);
             self->indent++;
     }

     python$target:::function-return
     /self->trace/
     {
             self->indent--;
             printf("%d\t%*s:", timestamp, 15, probename);
             printf("%*s", self->indent, "");
             printf("%s:%s:%d\n", basename(copyinstr(arg0)), copyinstr(arg1), arg2);
     }

     python$target:::function-return
     /copyinstr(arg1) == "start"/
     {
             self->trace = 0;
     }

It can be invoked like this:

     $ sudo dtrace -q -s call_stack.d -c "python3.6 script.py"

The output looks like this:

     156641360502280  function-entry:call_stack.py:start:23
     156641360518804  function-entry: call_stack.py:function_1:1
     156641360532797  function-entry:  call_stack.py:function_3:9
     156641360546807 function-return:  call_stack.py:function_3:10
     156641360563367 function-return: call_stack.py:function_1:2
     156641360578365  function-entry: call_stack.py:function_2:5
     156641360591757  function-entry:  call_stack.py:function_1:1
     156641360605556  function-entry:   call_stack.py:function_3:9
     156641360617482 function-return:   call_stack.py:function_3:10
     156641360629814 function-return:  call_stack.py:function_1:2
     156641360642285 function-return: call_stack.py:function_2:6
     156641360656770  function-entry: call_stack.py:function_3:9
     156641360669707 function-return: call_stack.py:function_3:10
     156641360687853  function-entry: call_stack.py:function_4:13
     156641360700719 function-return: call_stack.py:function_4:14
     156641360719640  function-entry: call_stack.py:function_5:18
     156641360732567 function-return: call_stack.py:function_5:21
     156641360747370 function-return:call_stack.py:start:28


File: python.info,  Node: Static SystemTap markers,  Next: Available static markers,  Prev: Static DTrace probes,  Up: Instrumenting CPython with DTrace and SystemTap

9.16.3 Static SystemTap markers
-------------------------------

The low-level way to use the SystemTap integration is to use the static
markers directly.  This requires you to explicitly state the binary file
containing them.

For example, this SystemTap script can be used to show the call/return
hierarchy of a Python script:

     probe process("python").mark("function__entry") {
          filename = user_string($arg1);
          funcname = user_string($arg2);
          lineno = $arg3;

          printf("%s => %s in %s:%d\\n",
                 thread_indent(1), funcname, filename, lineno);
     }

     probe process("python").mark("function__return") {
         filename = user_string($arg1);
         funcname = user_string($arg2);
         lineno = $arg3;

         printf("%s <= %s in %s:%d\\n",
                thread_indent(-1), funcname, filename, lineno);
     }

It can be invoked like this:

     $ stap \
       show-call-hierarchy.stp \
       -c "./python test.py"

The output looks like this:

     11408 python(8274):        => __contains__ in Lib/_abcoll.py:362
     11414 python(8274):         => __getitem__ in Lib/os.py:425
     11418 python(8274):          => encode in Lib/os.py:490
     11424 python(8274):          <= encode in Lib/os.py:493
     11428 python(8274):         <= __getitem__ in Lib/os.py:426
     11433 python(8274):        <= __contains__ in Lib/_abcoll.py:366

where the columns are:

   - time in microseconds since start of script

   - name of executable

   - PID of process

and the remainder indicates the call/return hierarchy as the script
executes.

For a *note -enable-shared: a65. build of CPython, the markers are
contained within the libpython shared library, and the probe’s dotted
path needs to reflect this.  For example, this line from the above
example:

     probe process("python").mark("function__entry") {

should instead read:

     probe process("python").library("libpython3.6dm.so.1.0").mark("function__entry") {

(assuming a *note debug build: 50a. of CPython 3.6)


File: python.info,  Node: Available static markers,  Next: SystemTap Tapsets,  Prev: Static SystemTap markers,  Up: Instrumenting CPython with DTrace and SystemTap

9.16.4 Available static markers
-------------------------------

 -- Object: function__entry(str filename, str funcname, int lineno)

     This marker indicates that execution of a Python function has
     begun.  It is only triggered for pure-Python (bytecode) functions.

     The filename, function name, and line number are provided back to
     the tracing script as positional arguments, which must be accessed
     using ‘$arg1’, ‘$arg2’, ‘$arg3’:

             * ‘$arg1’ : ‘(const char *)’ filename, accessible using
               ‘user_string($arg1)’

             * ‘$arg2’ : ‘(const char *)’ function name, accessible
               using ‘user_string($arg2)’

             * ‘$arg3’ : ‘int’ line number

 -- Object: function__return(str filename, str funcname, int lineno)

     This marker is the converse of ‘function__entry()’, and indicates
     that execution of a Python function has ended (either via ‘return’,
     or via an exception).  It is only triggered for pure-Python
     (bytecode) functions.

     The arguments are the same as for ‘function__entry()’

 -- Object: line(str filename, str funcname, int lineno)

     This marker indicates a Python line is about to be executed.  It is
     the equivalent of line-by-line tracing with a Python profiler.  It
     is not triggered within C functions.

     The arguments are the same as for ‘function__entry()’.

 -- Object: gc__start(int generation)

     Fires when the Python interpreter starts a garbage collection
     cycle.  ‘arg0’ is the generation to scan, like *note gc.collect():
     1b3.

 -- Object: gc__done(long collected)

     Fires when the Python interpreter finishes a garbage collection
     cycle.  ‘arg0’ is the number of collected objects.

 -- Object: import__find__load__start(str modulename)

     Fires before *note importlib: 7b. attempts to find and load the
     module.  ‘arg0’ is the module name.

     Added in version 3.7.

 -- Object: import__find__load__done(str modulename, int found)

     Fires after *note importlib: 7b.’s find_and_load function is
     called.  ‘arg0’ is the module name, ‘arg1’ indicates if module was
     successfully loaded.

     Added in version 3.7.

 -- Object: audit(str event, void *tuple)

     Fires when *note sys.audit(): 1903. or *note PySys_Audit(): 613. is
     called.  ‘arg0’ is the event name as C string, ‘arg1’ is a *note
     PyObject: 5df. pointer to a tuple object.

     Added in version 3.8.


File: python.info,  Node: SystemTap Tapsets,  Next: Examples<40>,  Prev: Available static markers,  Up: Instrumenting CPython with DTrace and SystemTap

9.16.5 SystemTap Tapsets
------------------------

The higher-level way to use the SystemTap integration is to use a
«tapset»: SystemTap’s equivalent of a library, which hides some of the
lower-level details of the static markers.

Here is a tapset file, based on a non-shared build of CPython:

     /*
        Provide a higher-level wrapping around the function__entry and
        function__return markers:
      \*/
     probe python.function.entry = process("python").mark("function__entry")
     {
         filename = user_string($arg1);
         funcname = user_string($arg2);
         lineno = $arg3;
         frameptr = $arg4
     }
     probe python.function.return = process("python").mark("function__return")
     {
         filename = user_string($arg1);
         funcname = user_string($arg2);
         lineno = $arg3;
         frameptr = $arg4
     }

If this file is installed in SystemTap’s tapset directory (e.g.
‘/usr/share/systemtap/tapset’), then these additional probepoints become
available:

 -- Object: python.function.entry(str filename, str funcname, int
          lineno, frameptr)

     This probe point indicates that execution of a Python function has
     begun.  It is only triggered for pure-Python (bytecode) functions.

 -- Object: python.function.return(str filename, str funcname, int
          lineno, frameptr)

     This probe point is the converse of ‘python.function.return’, and
     indicates that execution of a Python function has ended (either via
     ‘return’, or via an exception).  It is only triggered for
     pure-Python (bytecode) functions.


File: python.info,  Node: Examples<40>,  Prev: SystemTap Tapsets,  Up: Instrumenting CPython with DTrace and SystemTap

9.16.6 Examples
---------------

This SystemTap script uses the tapset above to more cleanly implement
the example given above of tracing the Python function-call hierarchy,
without needing to directly name the static markers:

     probe python.function.entry
     {
       printf("%s => %s in %s:%d\n",
              thread_indent(1), funcname, filename, lineno);
     }

     probe python.function.return
     {
       printf("%s <= %s in %s:%d\n",
              thread_indent(-1), funcname, filename, lineno);
     }

The following script uses the tapset above to provide a top-like view of
all running CPython code, showing the top 20 most frequently entered
bytecode frames, each second, across the whole system:

     global fn_calls;

     probe python.function.entry
     {
         fn_calls[pid(), filename, funcname, lineno] += 1;
     }

     probe timer.ms(1000) {
         printf("\033[2J\033[1;1H") /* clear screen \*/
         printf("%6s %80s %6s %30s %6s\n",
                "PID", "FILENAME", "LINE", "FUNCTION", "CALLS")
         foreach ([pid, filename, funcname, lineno] in fn_calls- limit 20) {
             printf("%6d %80s %6d %30s %6d\n",
                 pid, filename, lineno, funcname,
                 fn_calls[pid, filename, funcname, lineno]);
         }
         delete fn_calls;
     }


File: python.info,  Node: Python support for the Linux perf profiler,  Next: Annotations Best Practices,  Prev: Instrumenting CPython with DTrace and SystemTap,  Up: Python HOWTOs

9.17 Python support for the Linux ‘perf’ profiler
=================================================


author: Pablo Galindo

The Linux perf profiler(1) is a very powerful tool that allows you to
profile and obtain information about the performance of your
application.  ‘perf’ also has a very vibrant ecosystem of tools that aid
with the analysis of the data that it produces.

The main problem with using the ‘perf’ profiler with Python applications
is that ‘perf’ only gets information about native symbols, that is, the
names of functions and procedures written in C. This means that the
names and file names of Python functions in your code will not appear in
the output of ‘perf’.

Since Python 3.12, the interpreter can run in a special mode that allows
Python functions to appear in the output of the ‘perf’ profiler.  When
this mode is enabled, the interpreter will interpose a small piece of
code compiled on the fly before the execution of every Python function
and it will teach ‘perf’ the relationship between this piece of code and
the associated Python function using *note perf map files: 524a.

     Nota: Support for the ‘perf’ profiler is currently only available
     for Linux on select architectures.  Check the output of the
     ‘configure’ build step or check the output of ‘python -m sysconfig
     | grep HAVE_PERF_TRAMPOLINE’ to see if your system is supported.

For example, consider the following script:

     def foo(n):
         result = 0
         for _ in range(n):
             result += 1
         return result

     def bar(n):
         foo(n)

     def baz(n):
         bar(n)

     if __name__ == "__main__":
         baz(1000000)

We can run ‘perf’ to sample CPU stack traces at 9999 hertz:

     $ perf record -F 9999 -g -o perf.data python my_script.py

Then we can use ‘perf report’ to analyze the data:

     $ perf report --stdio -n -g

     # Children      Self       Samples  Command     Shared Object       Symbol
     # ........  ........  ............  ..........  ..................  ..........................................
     #
         91.08%     0.00%             0  python.exe  python.exe          [.] _start
                 |
                 ---_start
                 |
                     --90.71%--__libc_start_main
                             Py_BytesMain
                             |
                             |--56.88%--pymain_run_python.constprop.0
                             |          |
                             |          |--56.13%--_PyRun_AnyFileObject
                             |          |          _PyRun_SimpleFileObject
                             |          |          |
                             |          |          |--55.02%--run_mod
                             |          |          |          |
                             |          |          |           --54.65%--PyEval_EvalCode
                             |          |          |                     _PyEval_EvalFrameDefault
                             |          |          |                     PyObject_Vectorcall
                             |          |          |                     _PyEval_Vector
                             |          |          |                     _PyEval_EvalFrameDefault
                             |          |          |                     PyObject_Vectorcall
                             |          |          |                     _PyEval_Vector
                             |          |          |                     _PyEval_EvalFrameDefault
                             |          |          |                     PyObject_Vectorcall
                             |          |          |                     _PyEval_Vector
                             |          |          |                     |
                             |          |          |                     |--51.67%--_PyEval_EvalFrameDefault
                             |          |          |                     |          |
                             |          |          |                     |          |--11.52%--_PyLong_Add
                             |          |          |                     |          |          |
                             |          |          |                     |          |          |--2.97%--_PyObject_Malloc
     ...

As you can see, the Python functions are not shown in the output, only
‘_PyEval_EvalFrameDefault’ (the function that evaluates the Python
bytecode) shows up.  Unfortunately that’s not very useful because all
Python functions use the same C function to evaluate bytecode so we
cannot know which Python function corresponds to which
bytecode-evaluating function.

Instead, if we run the same experiment with ‘perf’ support enabled we
get:

     $ perf report --stdio -n -g

     # Children      Self       Samples  Command     Shared Object       Symbol
     # ........  ........  ............  ..........  ..................  .....................................................................
     #
         90.58%     0.36%             1  python.exe  python.exe          [.] _start
                 |
                 ---_start
                 |
                     --89.86%--__libc_start_main
                             Py_BytesMain
                             |
                             |--55.43%--pymain_run_python.constprop.0
                             |          |
                             |          |--54.71%--_PyRun_AnyFileObject
                             |          |          _PyRun_SimpleFileObject
                             |          |          |
                             |          |          |--53.62%--run_mod
                             |          |          |          |
                             |          |          |           --53.26%--PyEval_EvalCode
                             |          |          |                     py::<module>:/src/script.py
                             |          |          |                     _PyEval_EvalFrameDefault
                             |          |          |                     PyObject_Vectorcall
                             |          |          |                     _PyEval_Vector
                             |          |          |                     py::baz:/src/script.py
                             |          |          |                     _PyEval_EvalFrameDefault
                             |          |          |                     PyObject_Vectorcall
                             |          |          |                     _PyEval_Vector
                             |          |          |                     py::bar:/src/script.py
                             |          |          |                     _PyEval_EvalFrameDefault
                             |          |          |                     PyObject_Vectorcall
                             |          |          |                     _PyEval_Vector
                             |          |          |                     py::foo:/src/script.py
                             |          |          |                     |
                             |          |          |                     |--51.81%--_PyEval_EvalFrameDefault
                             |          |          |                     |          |
                             |          |          |                     |          |--13.77%--_PyLong_Add
                             |          |          |                     |          |          |
                             |          |          |                     |          |          |--3.26%--_PyObject_Malloc

* Menu:

* How to enable perf profiling support::
* How to obtain the best results::
* How to work without frame pointers::

   ---------- Footnotes ----------

   (1) https://perf.wiki.kernel.org


File: python.info,  Node: How to enable perf profiling support,  Next: How to obtain the best results,  Up: Python support for the Linux perf profiler

9.17.1 How to enable ‘perf’ profiling support
---------------------------------------------

‘perf’ profiling support can be enabled either from the start using the
environment variable *note PYTHONPERFSUPPORT: 69a. or the *note -X perf:
16f. option, or dynamically using *note sys.activate_stack_trampoline():
69b. and *note sys.deactivate_stack_trampoline(): 69c.

The ‘sys’ functions take precedence over the ‘-X’ option, the ‘-X’
option takes precedence over the environment variable.

Example, using the environment variable:

     $ PYTHONPERFSUPPORT=1 perf record -F 9999 -g -o perf.data python my_script.py
     $ perf report -g -i perf.data

Example, using the ‘-X’ option:

     $ perf record -F 9999 -g -o perf.data python -X perf my_script.py
     $ perf report -g -i perf.data

Example, using the *note sys: df. APIs in file ‘example.py’:

     import sys

     sys.activate_stack_trampoline("perf")
     do_profiled_stuff()
     sys.deactivate_stack_trampoline()

     non_profiled_stuff()

…then:

     $ perf record -F 9999 -g -o perf.data python ./example.py
     $ perf report -g -i perf.data


File: python.info,  Node: How to obtain the best results,  Next: How to work without frame pointers,  Prev: How to enable perf profiling support,  Up: Python support for the Linux perf profiler

9.17.2 How to obtain the best results
-------------------------------------

For best results, Python should be compiled with
‘CFLAGS="-fno-omit-frame-pointer -mno-omit-leaf-frame-pointer"’ as this
allows profilers to unwind using only the frame pointer and not on DWARF
debug information.  This is because as the code that is interposed to
allow ‘perf’ support is dynamically generated it doesn’t have any DWARF
debugging information available.

You can check if your system has been compiled with this flag by
running:

     $ python -m sysconfig | grep 'no-omit-frame-pointer'

If you don’t see any output it means that your interpreter has not been
compiled with frame pointers and therefore it may not be able to show
Python functions in the output of ‘perf’.


File: python.info,  Node: How to work without frame pointers,  Prev: How to obtain the best results,  Up: Python support for the Linux perf profiler

9.17.3 How to work without frame pointers
-----------------------------------------

If you are working with a Python interpreter that has been compiled
without frame pointers, you can still use the ‘perf’ profiler, but the
overhead will be a bit higher because Python needs to generate unwinding
information for every Python function call on the fly.  Additionally,
‘perf’ will take more time to process the data because it will need to
use the DWARF debugging information to unwind the stack and this is a
slow process.

To enable this mode, you can use the environment variable *note
PYTHON_PERF_JIT_SUPPORT: 4b0. or the *note -X perf_jit: 16f. option,
which will enable the JIT mode for the ‘perf’ profiler.

     Nota: Due to a bug in the ‘perf’ tool, only ‘perf’ versions higher
     than v6.8 will work with the JIT mode.  The fix was also backported
     to the v6.7.2 version of the tool.

     Note that when checking the version of the ‘perf’ tool (which can
     be done by running ‘perf version’) you must take into account that
     some distros add some custom version numbers including a ‘-’
     character.  This means that ‘perf 6.7-3’ is not necessarily ‘perf
     6.7.3’.

When using the perf JIT mode, you need an extra step before you can run
‘perf report’.  You need to call the ‘perf inject’ command to inject the
JIT information into the ‘perf.data’ file.:

     $ perf record -F 9999 -g -k 1 --call-graph dwarf -o perf.data python -Xperf_jit my_script.py
     $ perf inject -i perf.data --jit --output perf.jit.data
     $ perf report -g -i perf.jit.data

or using the environment variable:

     $ PYTHON_PERF_JIT_SUPPORT=1 perf record -F 9999 -g --call-graph dwarf -o perf.data python my_script.py
     $ perf inject -i perf.data --jit --output perf.jit.data
     $ perf report -g -i perf.jit.data

‘perf inject --jit’ command will read ‘perf.data’, automatically pick up
the perf dump file that Python creates (in ‘/tmp/perf-$PID.dump’), and
then create ‘perf.jit.data’ which merges all the JIT information
together.  It should also create a lot of ‘jitted-XXXX-N.so’ files in
the current directory which are ELF images for all the JIT trampolines
that were created by Python.

     Avvertimento: When using ‘--call-graph dwarf’, the ‘perf’ tool will
     take snapshots of the stack of the process being profiled and save
     the information in the ‘perf.data’ file.  By default, the size of
     the stack dump is 8192 bytes, but you can change the size by
     passing it after a comma like ‘--call-graph dwarf,16384’.

     The size of the stack dump is important because if the size is too
     small ‘perf’ will not be able to unwind the stack and the output
     will be incomplete.  On the other hand, if the size is too big,
     then ‘perf’ won’t be able to sample the process as frequently as it
     would like as the overhead will be higher.

     The stack size is particularly important when profiling Python code
     compiled with low optimization levels (like ‘-O0’), as these builds
     tend to have larger stack frames.  If you are compiling Python with
     ‘-O0’ and not seeing Python functions in your profiling output, try
     increasing the stack dump size to 65528 bytes (the maximum):

          $ perf record -F 9999 -g -k 1 --call-graph dwarf,65528 -o perf.data python -Xperf_jit my_script.py

     Different compilation flags can significantly impact stack sizes:

        - Builds with ‘-O0’ typically have much larger stack frames than
          those with ‘-O1’ or higher

        - Adding optimizations (‘-O1’, ‘-O2’, etc.)  typically reduces
          stack size

        - Frame pointers (‘-fno-omit-frame-pointer’) generally provide
          more reliable stack unwinding


File: python.info,  Node: Annotations Best Practices,  Next: Isolating Extension Modules,  Prev: Python support for the Linux perf profiler,  Up: Python HOWTOs

9.18 Annotations Best Practices
===============================


author: Larry Hastings

Abstract
........

This document is designed to encapsulate the best practices for working
with annotations dicts.  If you write Python code that examines
‘__annotations__’ on Python objects, we encourage you to follow the
guidelines described below.

The document is organized into four sections: best practices for
accessing the annotations of an object in Python versions 3.10 and
newer, best practices for accessing the annotations of an object in
Python versions 3.9 and older, other best practices for
‘__annotations__’ that apply to any Python version, and quirks of
‘__annotations__’.

Note that this document is specifically about working with
‘__annotations__’, not uses 'for' annotations.  If you’re looking for
information on how to use «type hints» in your code, please see the
*note typing: 10a. module.

* Menu:

* Accessing The Annotations Dict Of An Object In Python 3.10 And Newer: Accessing The Annotations Dict Of An Object In Python 3 10 And Newer.
* Accessing The Annotations Dict Of An Object In Python 3.9 And Older: Accessing The Annotations Dict Of An Object In Python 3 9 And Older.
* Manually Un-Stringizing Stringized Annotations::
* Best Practices For __annotations__ In Any Python Version::
* __annotations__ Quirks::


File: python.info,  Node: Accessing The Annotations Dict Of An Object In Python 3 10 And Newer,  Next: Accessing The Annotations Dict Of An Object In Python 3 9 And Older,  Up: Annotations Best Practices

9.18.1 Accessing The Annotations Dict Of An Object In Python 3.10 And Newer
---------------------------------------------------------------------------

Python 3.10 adds a new function to the standard library: *note
inspect.get_annotations(): a16.  In Python versions 3.10 through 3.13,
calling this function is the best practice for accessing the annotations
dict of any object that supports annotations.  This function can also
«un-stringize» stringized annotations for you.

In Python 3.14, there is a new *note annotationlib: 6. module with
functionality for working with annotations.  This includes a *note
annotationlib.get_annotations(): 459. function, which supersedes *note
inspect.get_annotations(): a16.

If for some reason *note inspect.get_annotations(): a16. isn’t viable
for your use case, you may access the ‘__annotations__’ data member
manually.  Best practice for this changed in Python 3.10 as well: as of
Python 3.10, ‘o.__annotations__’ is guaranteed to 'always' work on
Python functions, classes, and modules.  If you’re certain the object
you’re examining is one of these three 'specific' objects, you may
simply use ‘o.__annotations__’ to get at the object’s annotations dict.

However, other types of callables–for example, callables created by
*note functools.partial(): 217.–may not have an ‘__annotations__’
attribute defined.  When accessing the ‘__annotations__’ of a possibly
unknown object, best practice in Python versions 3.10 and newer is to
call *note getattr(): dcc. with three arguments, for example ‘getattr(o,
'__annotations__', None)’.

Before Python 3.10, accessing ‘__annotations__’ on a class that defines
no annotations but that has a parent class with annotations would return
the parent’s ‘__annotations__’.  In Python 3.10 and newer, the child
class’s annotations will be an empty dict instead.


File: python.info,  Node: Accessing The Annotations Dict Of An Object In Python 3 9 And Older,  Next: Manually Un-Stringizing Stringized Annotations,  Prev: Accessing The Annotations Dict Of An Object In Python 3 10 And Newer,  Up: Annotations Best Practices

9.18.2 Accessing The Annotations Dict Of An Object In Python 3.9 And Older
--------------------------------------------------------------------------

In Python 3.9 and older, accessing the annotations dict of an object is
much more complicated than in newer versions.  The problem is a design
flaw in these older versions of Python, specifically to do with class
annotations.

Best practice for accessing the annotations dict of other
objects–functions, other callables, and modules–is the same as best
practice for 3.10, assuming you aren’t calling *note
inspect.get_annotations(): a16.: you should use three-argument *note
getattr(): dcc. to access the object’s ‘__annotations__’ attribute.

Unfortunately, this isn’t best practice for classes.  The problem is
that, since ‘__annotations__’ is optional on classes, and because
classes can inherit attributes from their base classes, accessing the
‘__annotations__’ attribute of a class may inadvertently return the
annotations dict of a 'base class.'  As an example:

     class Base:
         a: int = 3
         b: str = 'abc'

     class Derived(Base):
         pass

     print(Derived.__annotations__)

This will print the annotations dict from ‘Base’, not ‘Derived’.

Your code will have to have a separate code path if the object you’re
examining is a class (‘isinstance(o, type)’).  In that case, best
practice relies on an implementation detail of Python 3.9 and before: if
a class has annotations defined, they are stored in the class’s *note
__dict__: e59. dictionary.  Since the class may or may not have
annotations defined, best practice is to call the *note get(): 201e.
method on the class dict.

To put it all together, here is some sample code that safely accesses
the ‘__annotations__’ attribute on an arbitrary object in Python 3.9 and
before:

     if isinstance(o, type):
         ann = o.__dict__.get('__annotations__', None)
     else:
         ann = getattr(o, '__annotations__', None)

After running this code, ‘ann’ should be either a dictionary or ‘None’.
You’re encouraged to double-check the type of ‘ann’ using *note
isinstance(): 2ad. before further examination.

Note that some exotic or malformed type objects may not have a *note
__dict__: e59. attribute, so for extra safety you may also wish to use
*note getattr(): dcc. to access ‘__dict__’.


File: python.info,  Node: Manually Un-Stringizing Stringized Annotations,  Next: Best Practices For __annotations__ In Any Python Version,  Prev: Accessing The Annotations Dict Of An Object In Python 3 9 And Older,  Up: Annotations Best Practices

9.18.3 Manually Un-Stringizing Stringized Annotations
-----------------------------------------------------

In situations where some annotations may be «stringized», and you wish
to evaluate those strings to produce the Python values they represent,
it really is best to call *note inspect.get_annotations(): a16. to do
this work for you.

If you’re using Python 3.9 or older, or if for some reason you can’t use
*note inspect.get_annotations(): a16, you’ll need to duplicate its
logic.  You’re encouraged to examine the implementation of *note
inspect.get_annotations(): a16. in the current Python version and follow
a similar approach.

In a nutshell, if you wish to evaluate a stringized annotation on an
arbitrary object ‘o’:

   * If ‘o’ is a module, use ‘o.__dict__’ as the ‘globals’ when calling
     *note eval(): 4a4.

   * If ‘o’ is a class, use ‘sys.modules[o.__module__].__dict__’ as the
     ‘globals’, and ‘dict(vars(o))’ as the ‘locals’, when calling *note
     eval(): 4a4.

   * If ‘o’ is a wrapped callable using *note
     functools.update_wrapper(): 1224, *note functools.wraps(): 115f, or
     *note functools.partial(): 217, iteratively unwrap it by accessing
     either ‘o.__wrapped__’ or ‘o.func’ as appropriate, until you have
     found the root unwrapped function.

   * If ‘o’ is a callable (but not a class), use *note o.__globals__:
     14db. as the globals when calling *note eval(): 4a4.

However, not all string values used as annotations can be successfully
turned into Python values by *note eval(): 4a4.  String values could
theoretically contain any valid string, and in practice there are valid
use cases for type hints that require annotating with string values that
specifically 'can’t' be evaluated.  For example:

   * PEP 604(1) union types using ‘|’, before support for this was added
     to Python 3.10.

   * Definitions that aren’t needed at runtime, only imported when *note
     typing.TYPE_CHECKING: ef2. is true.

If *note eval(): 4a4. attempts to evaluate such values, it will fail and
raise an exception.  So, when designing a library API that works with
annotations, it’s recommended to only attempt to evaluate string values
when explicitly requested to by the caller.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0604/


File: python.info,  Node: Best Practices For __annotations__ In Any Python Version,  Next: __annotations__ Quirks,  Prev: Manually Un-Stringizing Stringized Annotations,  Up: Annotations Best Practices

9.18.4 Best Practices For ‘__annotations__’ In Any Python Version
-----------------------------------------------------------------

   * You should avoid assigning to the ‘__annotations__’ member of
     objects directly.  Let Python manage setting ‘__annotations__’.

   * If you do assign directly to the ‘__annotations__’ member of an
     object, you should always set it to a ‘dict’ object.

   * You should avoid accessing ‘__annotations__’ directly on any
     object.  Instead, use *note annotationlib.get_annotations(): 459.
     (Python 3.14+) or *note inspect.get_annotations(): a16. (Python
     3.10+).

   * If you do directly access the ‘__annotations__’ member of an
     object, you should ensure that it’s a dictionary before attempting
     to examine its contents.

   * You should avoid modifying ‘__annotations__’ dicts.

   * You should avoid deleting the ‘__annotations__’ attribute of an
     object.


File: python.info,  Node: __annotations__ Quirks,  Prev: Best Practices For __annotations__ In Any Python Version,  Up: Annotations Best Practices

9.18.5 ‘__annotations__’ Quirks
-------------------------------

In all versions of Python 3, function objects lazy-create an annotations
dict if no annotations are defined on that object.  You can delete the
‘__annotations__’ attribute using ‘del fn.__annotations__’, but if you
then access ‘fn.__annotations__’ the object will create a new empty dict
that it will store and return as its annotations.  Deleting the
annotations on a function before it has lazily created its annotations
dict will throw an ‘AttributeError’; using ‘del fn.__annotations__’
twice in a row is guaranteed to always throw an ‘AttributeError’.

Everything in the above paragraph also applies to class and module
objects in Python 3.10 and newer.

In all versions of Python 3, you can set ‘__annotations__’ on a function
object to ‘None’.  However, subsequently accessing the annotations on
that object using ‘fn.__annotations__’ will lazy-create an empty
dictionary as per the first paragraph of this section.  This is 'not'
true of modules and classes, in any Python version; those objects permit
setting ‘__annotations__’ to any Python value, and will retain whatever
value is set.

If Python stringizes your annotations for you (using ‘from __future__
import annotations’), and you specify a string as an annotation, the
string will itself be quoted.  In effect the annotation is quoted
'twice.'  For example:

     from __future__ import annotations
     def foo(a: "str"): pass

     print(foo.__annotations__)

This prints ‘{'a': "'str'"}’.  This shouldn’t really be considered a
«quirk»; it’s mentioned here simply because it might be surprising.

If you use a class with a custom metaclass and access ‘__annotations__’
on the class, you may observe unexpected behavior; see 749(1) for some
examples.  You can avoid these quirks by using *note
annotationlib.get_annotations(): 459. on Python 3.14+ or *note
inspect.get_annotations(): a16. on Python 3.10+.  On earlier versions of
Python, you can avoid these bugs by accessing the annotations from the
class’s *note __dict__: e59. (for example,
‘cls.__dict__.get('__annotations__', None)’).

In some versions of Python, instances of classes may have an
‘__annotations__’ attribute.  However, this is not supported
functionality.  If you need the annotations of an instance, you can use
*note type(): f46. to access its class (for example,
‘annotationlib.get_annotations(type(myinstance))’ on Python 3.14+).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0749/#pep749-metaclasses


File: python.info,  Node: Isolating Extension Modules,  Next: timer file descriptor HOWTO,  Prev: Annotations Best Practices,  Up: Python HOWTOs

9.19 Isolating Extension Modules
================================

Abstract
........

Traditionally, state belonging to Python extension modules was kept in C
‘static’ variables, which have process-wide scope.  This document
describes problems of such per-process state and shows a safer way:
per-module state.

The document also describes how to switch to per-module state where
possible.  This transition involves allocating space for that state,
potentially switching from static types to heap types, and—perhaps most
importantly—accessing per-module state from code.

* Menu:

* Who should read this::
* Background: Background<2>.
* Making Modules Safe with Multiple Interpreters::
* Heap Types: Heap Types<2>.
* Open Issues::


File: python.info,  Node: Who should read this,  Next: Background<2>,  Up: Isolating Extension Modules

9.19.1 Who should read this
---------------------------

This guide is written for maintainers of *note C-API: 1fa6. extensions
who would like to make that extension safer to use in applications where
Python itself is used as a library.


File: python.info,  Node: Background<2>,  Next: Making Modules Safe with Multiple Interpreters,  Prev: Who should read this,  Up: Isolating Extension Modules

9.19.2 Background
-----------------

An 'interpreter' is the context in which Python code runs.  It contains
configuration (e.g.  the import path) and runtime state (e.g.  the set
of imported modules).

Python supports running multiple interpreters in one process.  There are
two cases to think about—users may run interpreters:

   - in sequence, with several *note Py_InitializeEx(): 510b./*note
     Py_FinalizeEx(): f13. cycles, and

   - in parallel, managing «sub-interpreters» using *note
     Py_NewInterpreter(): 1b19./*note Py_EndInterpreter(): 182d.

Both cases (and combinations of them) would be most useful when
embedding Python within a library.  Libraries generally shouldn’t make
assumptions about the application that uses them, which include assuming
a process-wide «main Python interpreter».

Historically, Python extension modules don’t handle this use case well.
Many extension modules (and even some stdlib modules) use 'per-process'
global state, because C ‘static’ variables are extremely easy to use.
Thus, data that should be specific to an interpreter ends up being
shared between interpreters.  Unless the extension developer is careful,
it is very easy to introduce edge cases that lead to crashes when a
module is loaded in more than one interpreter in the same process.

Unfortunately, 'per-interpreter' state is not easy to achieve.
Extension authors tend to not keep multiple interpreters in mind when
developing, and it is currently cumbersome to test the behavior.

* Menu:

* Enter Per-Module State::
* Isolated Module Objects::
* Surprising Edge Cases::


File: python.info,  Node: Enter Per-Module State,  Next: Isolated Module Objects,  Up: Background<2>

9.19.2.1 Enter Per-Module State
...............................

Instead of focusing on per-interpreter state, Python’s C API is evolving
to better support the more granular 'per-module' state.  This means that
C-level data should be attached to a 'module object'.  Each interpreter
creates its own module object, keeping the data separate.  For testing
the isolation, multiple module objects corresponding to a single
extension can even be loaded in a single interpreter.

Per-module state provides an easy way to think about lifetime and
resource ownership: the extension module will initialize when a module
object is created, and clean up when it’s freed.  In this regard, a
module is just like any other *note PyObject: 5df.*; there are no «on
interpreter shutdown» hooks to think—or forget—about.

Note that there are use cases for different kinds of «globals»:
per-process, per-interpreter, per-thread or per-task state.  With
per-module state as the default, these are still possible, but you
should treat them as exceptional cases: if you need them, you should
give them additional care and testing.  (Note that this guide does not
cover them.)


File: python.info,  Node: Isolated Module Objects,  Next: Surprising Edge Cases,  Prev: Enter Per-Module State,  Up: Background<2>

9.19.2.2 Isolated Module Objects
................................

The key point to keep in mind when developing an extension module is
that several module objects can be created from a single shared library.
For example:

     >>> import sys
     >>> import binascii
     >>> old_binascii = binascii
     >>> del sys.modules['binascii']
     >>> import binascii  # create a new module object
     >>> old_binascii == binascii
     False

As a rule of thumb, the two modules should be completely independent.
All objects and state specific to the module should be encapsulated
within the module object, not shared with other module objects, and
cleaned up when the module object is deallocated.  Since this just is a
rule of thumb, exceptions are possible (see *note Managing Global State:
580f.), but they will need more thought and attention to edge cases.

While some modules could do with less stringent restrictions, isolated
modules make it easier to set clear expectations and guidelines that
work across a variety of use cases.


File: python.info,  Node: Surprising Edge Cases,  Prev: Isolated Module Objects,  Up: Background<2>

9.19.2.3 Surprising Edge Cases
..............................

Note that isolated modules do create some surprising edge cases.  Most
notably, each module object will typically not share its classes and
exceptions with other similar modules.  Continuing from the *note
example above: 580e, note that ‘old_binascii.Error’ and ‘binascii.Error’
are separate objects.  In the following code, the exception is 'not'
caught:

     >>> old_binascii.Error == binascii.Error
     False
     >>> try:
     ...     old_binascii.unhexlify(b'qwertyuiop')
     ... except binascii.Error:
     ...     print('boo')
     ...
     Traceback (most recent call last):
       File "<stdin>", line 2, in <module>
     binascii.Error: Non-hexadecimal digit found

This is expected.  Notice that pure-Python modules behave the same way:
it is a part of how Python works.

The goal is to make extension modules safe at the C level, not to make
hacks behave intuitively.  Mutating ‘sys.modules’ «manually» counts as a
hack.


File: python.info,  Node: Making Modules Safe with Multiple Interpreters,  Next: Heap Types<2>,  Prev: Background<2>,  Up: Isolating Extension Modules

9.19.3 Making Modules Safe with Multiple Interpreters
-----------------------------------------------------

* Menu:

* Managing Global State::
* Managing Per-Module State::
* Opt-Out; Limiting to One Module Object per Process: Opt-Out Limiting to One Module Object per Process.
* Module State Access from Functions::


File: python.info,  Node: Managing Global State,  Next: Managing Per-Module State,  Up: Making Modules Safe with Multiple Interpreters

9.19.3.1 Managing Global State
..............................

Sometimes, the state associated with a Python module is not specific to
that module, but to the entire process (or something else «more global»
than a module).  For example:

   - The ‘readline’ module manages 'the' terminal.

   - A module running on a circuit board wants to control 'the' on-board
     LED.

In these cases, the Python module should provide 'access' to the global
state, rather than 'own' it.  If possible, write the module so that
multiple copies of it can access the state independently (along with
other libraries, whether for Python or other languages).  If that is not
possible, consider explicit locking.

If it is necessary to use process-global state, the simplest way to
avoid issues with multiple interpreters is to explicitly prevent a
module from being loaded more than once per process—see *note Opt-Out;
Limiting to One Module Object per Process: 51e8.


File: python.info,  Node: Managing Per-Module State,  Next: Opt-Out Limiting to One Module Object per Process,  Prev: Managing Global State,  Up: Making Modules Safe with Multiple Interpreters

9.19.3.2 Managing Per-Module State
..................................

To use per-module state, use *note multi-phase extension module
initialization: 51eb.  This signals that your module supports multiple
interpreters correctly.

Set ‘PyModuleDef.m_size’ to a positive number to request that many bytes
of storage local to the module.  Usually, this will be set to the size
of some module-specific ‘struct’, which can store all of the module’s
C-level state.  In particular, it is where you should put pointers to
classes (including exceptions, but excluding static types) and settings
(e.g.  ‘csv’’s *note field_size_limit: 1b79.) which the C code needs to
function.

     Nota: Another option is to store state in the module’s ‘__dict__’,
     but you must avoid crashing when users modify ‘__dict__’ from
     Python code.  This usually means error- and type-checking at the C
     level, which is easy to get wrong and hard to test sufficiently.

     However, if module state is not needed in C code, storing it in
     ‘__dict__’ only is a good idea.

If the module state includes ‘PyObject’ pointers, the module object must
hold references to those objects and implement the module-level hooks
‘m_traverse’, ‘m_clear’ and ‘m_free’.  These work like ‘tp_traverse’,
‘tp_clear’ and ‘tp_free’ of a class.  Adding them will require some work
and make the code longer; this is the price for modules which can be
unloaded cleanly.

An example of a module with per-module state is currently available as
xxlimited(1); example module initialization shown at the bottom of the
file.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/blob/master/Modules/xxlimited.c


File: python.info,  Node: Opt-Out Limiting to One Module Object per Process,  Next: Module State Access from Functions,  Prev: Managing Per-Module State,  Up: Making Modules Safe with Multiple Interpreters

9.19.3.3 Opt-Out: Limiting to One Module Object per Process
...........................................................

A non-negative ‘PyModuleDef.m_size’ signals that a module supports
multiple interpreters correctly.  If this is not yet the case for your
module, you can explicitly make your module loadable only once per
process.  For example:

     // A process-wide flag
     static int loaded = 0;

     // Mutex to provide thread safety (only needed for free-threaded Python)
     static PyMutex modinit_mutex = {0};

     static int
     exec_module(PyObject* module)
     {
         PyMutex_Lock(&modinit_mutex);
         if (loaded) {
             PyMutex_Unlock(&modinit_mutex);
             PyErr_SetString(PyExc_ImportError,
                             "cannot load module more than once per process");
             return -1;
         }
         loaded = 1;
         PyMutex_Unlock(&modinit_mutex);
         // ... rest of initialization
     }

If your module’s *note PyModuleDef.m_clear: b74. function is able to
prepare for future re-initialization, it should clear the ‘loaded’ flag.
In this case, your module won’t support multiple instances existing
'concurrently', but it will, for example, support being loaded after
Python runtime shutdown (*note Py_FinalizeEx(): f13.) and
re-initialization (*note Py_Initialize(): 460.).


File: python.info,  Node: Module State Access from Functions,  Prev: Opt-Out Limiting to One Module Object per Process,  Up: Making Modules Safe with Multiple Interpreters

9.19.3.4 Module State Access from Functions
...........................................

Accessing the state from module-level functions is straightforward.
Functions get the module object as their first argument; for extracting
the state, you can use ‘PyModule_GetState’:

     static PyObject *
     func(PyObject *module, PyObject *args)
     {
         my_struct *state = (my_struct*)PyModule_GetState(module);
         if (state == NULL) {
             return NULL;
         }
         // ... rest of logic
     }

     Nota: ‘PyModule_GetState’ may return ‘NULL’ without setting an
     exception if there is no module state, i.e.  ‘PyModuleDef.m_size’
     was zero.  In your own module, you’re in control of ‘m_size’, so
     this is easy to prevent.


File: python.info,  Node: Heap Types<2>,  Next: Open Issues,  Prev: Making Modules Safe with Multiple Interpreters,  Up: Isolating Extension Modules

9.19.4 Heap Types
-----------------

Traditionally, types defined in C code are 'static'; that is, ‘static
PyTypeObject’ structures defined directly in code and initialized using
‘PyType_Ready()’.

Such types are necessarily shared across the process.  Sharing them
between module objects requires paying attention to any state they own
or access.  To limit the possible issues, static types are immutable at
the Python level: for example, you can’t set ‘str.myattribute = 123’.

'Dettaglio dell’implementazione di CPython:' Sharing truly immutable
objects between interpreters is fine, as long as they don’t provide
access to mutable objects.  However, in CPython, every Python object has
a mutable implementation detail: the reference count.  Changes to the
refcount are guarded by the GIL. Thus, code that shares any Python
objects across interpreters implicitly depends on CPython’s current,
process-wide GIL.

Because they are immutable and process-global, static types cannot
access «their» module state.  If any method of such a type requires
access to module state, the type must be converted to a 'heap-allocated
type', or 'heap type' for short.  These correspond more closely to
classes created by Python’s ‘class’ statement.

For new modules, using heap types by default is a good rule of thumb.

* Menu:

* Changing Static Types to Heap Types::
* Defining Heap Types::
* Garbage-Collection Protocol::
* Module State Access from Classes::
* Module State Access from Regular Methods::
* Module State Access from Slot Methods, Getters and Setters: Module State Access from Slot Methods Getters and Setters.
* Lifetime of the Module State::


File: python.info,  Node: Changing Static Types to Heap Types,  Next: Defining Heap Types,  Up: Heap Types<2>

9.19.4.1 Changing Static Types to Heap Types
............................................

Static types can be converted to heap types, but note that the heap type
API was not designed for «lossless» conversion from static types—that
is, creating a type that works exactly like a given static type.  So,
when rewriting the class definition in a new API, you are likely to
unintentionally change a few details (e.g.  pickleability or inherited
slots).  Always test the details that are important to you.

Watch out for the following two points in particular (but note that this
is not a comprehensive list):

   * Unlike static types, heap type objects are mutable by default.  Use
     the *note Py_TPFLAGS_IMMUTABLETYPE: 3cf. flag to prevent
     mutability.

   * Heap types inherit *note tp_new: 7a0. by default, so it may become
     possible to instantiate them from Python code.  You can prevent
     this with the *note Py_TPFLAGS_DISALLOW_INSTANTIATION: 7a3. flag.


File: python.info,  Node: Defining Heap Types,  Next: Garbage-Collection Protocol,  Prev: Changing Static Types to Heap Types,  Up: Heap Types<2>

9.19.4.2 Defining Heap Types
............................

Heap types can be created by filling a *note PyType_Spec: 1a71.
structure, a description or «blueprint» of a class, and calling *note
PyType_FromModuleAndSpec(): 774. to construct a new class object.

     Nota: Other functions, like *note PyType_FromSpec(): 79e, can also
     create heap types, but *note PyType_FromModuleAndSpec(): 774.
     associates the module with the class, allowing access to the module
     state from methods.

The class should generally be stored in 'both' the module state (for
safe access from C) and the module’s ‘__dict__’ (for access from Python
code).


File: python.info,  Node: Garbage-Collection Protocol,  Next: Module State Access from Classes,  Prev: Defining Heap Types,  Up: Heap Types<2>

9.19.4.3 Garbage-Collection Protocol
....................................

Instances of heap types hold a reference to their type.  This ensures
that the type isn’t destroyed before all its instances are, but may
result in reference cycles that need to be broken by the garbage
collector.

To avoid memory leaks, instances of heap types must implement the
garbage collection protocol.  That is, heap types should:

   - Have the *note Py_TPFLAGS_HAVE_GC: 982. flag.

   - Define a traverse function using *note Py_tp_traverse: 5175, which
     visits the type (e.g.  using ‘Py_VISIT(Py_TYPE(self))’).

Please refer to the documentation of *note Py_TPFLAGS_HAVE_GC: 982. and
*note tp_traverse: 983. for additional considerations.

The API for defining heap types grew organically, leaving it somewhat
awkward to use in its current state.  The following sections will guide
you through common issues.

* Menu:

* tp_traverse in Python 3.8 and lower: tp_traverse in Python 3 8 and lower.
* Delegating tp_traverse::
* Defining tp_dealloc::
* Not overriding tp_free::
* Avoiding PyObject_New::


File: python.info,  Node: tp_traverse in Python 3 8 and lower,  Next: Delegating tp_traverse,  Up: Garbage-Collection Protocol

9.19.4.4 ‘tp_traverse’ in Python 3.8 and lower
..............................................

The requirement to visit the type from ‘tp_traverse’ was added in Python
3.9.  If you support Python 3.8 and lower, the traverse function must
'not' visit the type, so it must be more complicated:

     static int my_traverse(PyObject *self, visitproc visit, void *arg)
     {
         if (Py_Version >= 0x03090000) {
             Py_VISIT(Py_TYPE(self));
         }
         return 0;
     }

Unfortunately, *note Py_Version: 381. was only added in Python 3.11.  As
a replacement, use:

   * *note PY_VERSION_HEX: 382, if not using the stable ABI, or

   * *note sys.version_info: 8b0. (via *note PySys_GetObject(): 62a. and
     *note PyArg_ParseTuple(): 3c1.).


File: python.info,  Node: Delegating tp_traverse,  Next: Defining tp_dealloc,  Prev: tp_traverse in Python 3 8 and lower,  Up: Garbage-Collection Protocol

9.19.4.5 Delegating ‘tp_traverse’
.................................

If your traverse function delegates to the *note tp_traverse: 983. of
its base class (or another type), ensure that ‘Py_TYPE(self)’ is visited
only once.  Note that only heap type are expected to visit the type in
‘tp_traverse’.

For example, if your traverse function includes:

     base->tp_traverse(self, visit, arg)

…and ‘base’ may be a static type, then it should also include:

     if (base->tp_flags & Py_TPFLAGS_HEAPTYPE) {
         // a heap type's tp_traverse already visited Py_TYPE(self)
     } else {
         if (Py_Version >= 0x03090000) {
             Py_VISIT(Py_TYPE(self));
         }
     }

It is not necessary to handle the type’s reference count in *note
tp_new: 7a0. and *note tp_clear: 4ecb.


File: python.info,  Node: Defining tp_dealloc,  Next: Not overriding tp_free,  Prev: Delegating tp_traverse,  Up: Garbage-Collection Protocol

9.19.4.6 Defining ‘tp_dealloc’
..............................

If your type has a custom *note tp_dealloc: 4ea5. function, it needs to:

   - call *note PyObject_GC_UnTrack(): 170c. before any fields are
     invalidated, and

   - decrement the reference count of the type.

To keep the type valid while ‘tp_free’ is called, the type’s refcount
needs to be decremented 'after' the instance is deallocated.  For
example:

     static void my_dealloc(PyObject *self)
     {
         PyObject_GC_UnTrack(self);
         ...
         PyTypeObject *type = Py_TYPE(self);
         type->tp_free(self);
         Py_DECREF(type);
     }

The default ‘tp_dealloc’ function does this, so if your type does 'not'
override ‘tp_dealloc’ you don’t need to add it.


File: python.info,  Node: Not overriding tp_free,  Next: Avoiding PyObject_New,  Prev: Defining tp_dealloc,  Up: Garbage-Collection Protocol

9.19.4.7 Not overriding ‘tp_free’
.................................

The *note tp_free: 4eb8. slot of a heap type must be set to *note
PyObject_GC_Del(): 170a.  This is the default; do not override it.


File: python.info,  Node: Avoiding PyObject_New,  Prev: Not overriding tp_free,  Up: Garbage-Collection Protocol

9.19.4.8 Avoiding ‘PyObject_New’
................................

GC-tracked objects need to be allocated using GC-aware functions.

If you use *note PyObject_New(): b7e. or *note PyObject_NewVar(): b7f.:

   - Get and call type’s *note tp_alloc: 4eb9. slot, if possible.  That
     is, replace ‘TYPE *o = PyObject_New(TYPE, typeobj)’ with:

          TYPE *o = typeobj->tp_alloc(typeobj, 0);

     Replace ‘o = PyObject_NewVar(TYPE, typeobj, size)’ with the same,
     but use size instead of the 0.

   - If the above is not possible (e.g.  inside a custom ‘tp_alloc’),
     call *note PyObject_GC_New(): c9b. or *note PyObject_GC_NewVar():
     c9c.:

          TYPE *o = PyObject_GC_New(TYPE, typeobj);

          TYPE *o = PyObject_GC_NewVar(TYPE, typeobj, size);


File: python.info,  Node: Module State Access from Classes,  Next: Module State Access from Regular Methods,  Prev: Garbage-Collection Protocol,  Up: Heap Types<2>

9.19.4.9 Module State Access from Classes
.........................................

If you have a type object defined with *note PyType_FromModuleAndSpec():
774, you can call *note PyType_GetModule(): b68. to get the associated
module, and then *note PyModule_GetState(): b79. to get the module’s
state.

To save a some tedious error-handling boilerplate code, you can combine
these two steps with *note PyType_GetModuleState(): b69, resulting in:

     my_struct *state = (my_struct*)PyType_GetModuleState(type);
     if (state == NULL) {
         return NULL;
     }


File: python.info,  Node: Module State Access from Regular Methods,  Next: Module State Access from Slot Methods Getters and Setters,  Prev: Module State Access from Classes,  Up: Heap Types<2>

9.19.4.10 Module State Access from Regular Methods
..................................................

Accessing the module-level state from methods of a class is somewhat
more complicated, but is possible thanks to API introduced in Python
3.9.  To get the state, you need to first get the 'defining class', and
then get the module state from it.

The largest roadblock is getting 'the class a method was defined in', or
that method’s «defining class» for short.  The defining class can have a
reference to the module it is part of.

Do not confuse the defining class with ‘Py_TYPE(self)’.  If the method
is called on a 'subclass' of your type, ‘Py_TYPE(self)’ will refer to
that subclass, which may be defined in different module than yours.

     Nota: The following Python code can illustrate the concept.
     ‘Base.get_defining_class’ returns ‘Base’ even if ‘type(self) ==
     Sub’:

          class Base:
              def get_type_of_self(self):
                  return type(self)

              def get_defining_class(self):
                  return __class__

          class Sub(Base):
              pass

For a method to get its «defining class», it must use the *note
METH_METHOD | METH_FASTCALL | METH_KEYWORDS: 19f1. *note calling
convention: 16de. and the corresponding *note PyCMethod: 969. signature:

     PyObject *PyCMethod(
         PyObject *self,               // object the method was called on
         PyTypeObject *defining_class, // defining class
         PyObject *const *args,        // C array of arguments
         Py_ssize_t nargs,             // length of "args"
         PyObject *kwnames)            // NULL, or dict of keyword arguments

Once you have the defining class, call *note PyType_GetModuleState():
b69. to get the state of its associated module.

For example:

     static PyObject *
     example_method(PyObject *self,
             PyTypeObject *defining_class,
             PyObject *const *args,
             Py_ssize_t nargs,
             PyObject *kwnames)
     {
         my_struct *state = (my_struct*)PyType_GetModuleState(defining_class);
         if (state == NULL) {
             return NULL;
         }
         ... // rest of logic
     }

     PyDoc_STRVAR(example_method_doc, "...");

     static PyMethodDef my_methods[] = {
         {"example_method",
           (PyCFunction)(void(*)(void))example_method,
           METH_METHOD|METH_FASTCALL|METH_KEYWORDS,
           example_method_doc}
         {NULL},
     }


File: python.info,  Node: Module State Access from Slot Methods Getters and Setters,  Next: Lifetime of the Module State,  Prev: Module State Access from Regular Methods,  Up: Heap Types<2>

9.19.4.11 Module State Access from Slot Methods, Getters and Setters
....................................................................

     Nota: This is new in Python 3.11.

Slot methods—the fast C equivalents for special methods, such as *note
nb_add: 52bb. for *note __add__: 23c3. or *note tp_new: 7a0. for
initialization—have a very simple API that doesn’t allow passing in the
defining class, unlike with *note PyCMethod: 969.  The same goes for
getters and setters defined with *note PyGetSetDef: db4.

To access the module state in these cases, use the *note
PyType_GetModuleByDef(): 635. function, and pass in the module
definition.  Once you have the module, call *note PyModule_GetState():
b79. to get the state:

     PyObject *module = PyType_GetModuleByDef(Py_TYPE(self), &module_def);
     my_struct *state = (my_struct*)PyModule_GetState(module);
     if (state == NULL) {
         return NULL;
     }

‘PyType_GetModuleByDef()’ works by searching the *note method resolution
order: 25bd. (i.e.  all superclasses) for the first superclass that has
a corresponding module.

     Nota: In very exotic cases (inheritance chains spanning multiple
     modules created from the same definition),
     ‘PyType_GetModuleByDef()’ might not return the module of the true
     defining class.  However, it will always return a module with the
     same definition, ensuring a compatible C memory layout.


File: python.info,  Node: Lifetime of the Module State,  Prev: Module State Access from Slot Methods Getters and Setters,  Up: Heap Types<2>

9.19.4.12 Lifetime of the Module State
......................................

When a module object is garbage-collected, its module state is freed.
For each pointer to (a part of) the module state, you must hold a
reference to the module object.

Usually this is not an issue, because types created with *note
PyType_FromModuleAndSpec(): 774, and their instances, hold a reference
to the module.  However, you must be careful in reference counting when
you reference module state from other places, such as callbacks for
external libraries.


File: python.info,  Node: Open Issues,  Prev: Heap Types<2>,  Up: Isolating Extension Modules

9.19.5 Open Issues
------------------

Several issues around per-module state and heap types are still open.

Discussions about improving the situation are best held on the discuss
forum under c-api tag(1).

* Menu:

* Per-Class Scope::
* Lossless Conversion to Heap Types::

   ---------- Footnotes ----------

   (1) https://discuss.python.org/c/core-dev/c-api/30


File: python.info,  Node: Per-Class Scope,  Next: Lossless Conversion to Heap Types,  Up: Open Issues

9.19.5.1 Per-Class Scope
........................

It is currently (as of Python 3.11) not possible to attach state to
individual 'types' without relying on CPython implementation details
(which may change in the future—perhaps, ironically, to allow a proper
solution for per-class scope).


File: python.info,  Node: Lossless Conversion to Heap Types,  Prev: Per-Class Scope,  Up: Open Issues

9.19.5.2 Lossless Conversion to Heap Types
..........................................

The heap type API was not designed for «lossless» conversion from static
types; that is, creating a type that works exactly like a given static
type.


File: python.info,  Node: timer file descriptor HOWTO,  Next: The Python 2 3 Method Resolution Order,  Prev: Isolating Extension Modules,  Up: Python HOWTOs

9.20 timer file descriptor HOWTO
================================


Release: 1.13

This HOWTO discusses Python’s support for the linux timer file
descriptor.

* Menu:

* Examples: Examples<41>.


File: python.info,  Node: Examples<41>,  Up: timer file descriptor HOWTO

9.20.1 Examples
---------------

The following example shows how to use a timer file descriptor to
execute a function twice a second:

     # Practical scripts should use really use a non-blocking timer,
     # we use a blocking timer here for simplicity.
     import os, time

     # Create the timer file descriptor
     fd = os.timerfd_create(time.CLOCK_REALTIME)

     # Start the timer in 1 second, with an interval of half a second
     os.timerfd_settime(fd, initial=1, interval=0.5)

     try:
         # Process timer events four times.
         for _ in range(4):
             # read() will block until the timer expires
             _ = os.read(fd, 8)
             print("Timer expired")
     finally:
         # Remember to close the timer file descriptor!
         os.close(fd)

To avoid the precision loss caused by the *note float: 196. type, timer
file descriptors allow specifying initial expiration and interval in
integer nanoseconds with ‘_ns’ variants of the functions.

This example shows how *note epoll(): 1196. can be used with timer file
descriptors to wait until the file descriptor is ready for reading:

     import os, time, select, socket, sys

     # Create an epoll object
     ep = select.epoll()

     # In this example, use loopback address to send "stop" command to the server.
     #
     # $ telnet 127.0.0.1 1234
     # Trying 127.0.0.1...
     # Connected to 127.0.0.1.
     # Escape character is '^]'.
     # stop
     # Connection closed by foreign host.
     #
     sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     sock.bind(("127.0.0.1", 1234))
     sock.setblocking(False)
     sock.listen(1)
     ep.register(sock, select.EPOLLIN)

     # Create timer file descriptors in non-blocking mode.
     num = 3
     fds = []
     for _ in range(num):
         fd = os.timerfd_create(time.CLOCK_REALTIME, flags=os.TFD_NONBLOCK)
         fds.append(fd)
         # Register the timer file descriptor for read events
         ep.register(fd, select.EPOLLIN)

     # Start the timer with os.timerfd_settime_ns() in nanoseconds.
     # Timer 1 fires every 0.25 seconds; timer 2 every 0.5 seconds; etc
     for i, fd in enumerate(fds, start=1):
         one_sec_in_nsec = 10**9
         i = i * one_sec_in_nsec
         os.timerfd_settime_ns(fd, initial=i//4, interval=i//4)

     timeout = 3
     try:
         conn = None
         is_active = True
         while is_active:
             # Wait for the timer to expire for 3 seconds.
             # epoll.poll() returns a list of (fd, event) pairs.
             # fd is a file descriptor.
             # sock and conn[=returned value of socket.accept()] are socket objects, not file descriptors.
             # So use sock.fileno() and conn.fileno() to get the file descriptors.
             events = ep.poll(timeout)

             # If more than one timer file descriptors are ready for reading at once,
             # epoll.poll() returns a list of (fd, event) pairs.
             #
             # In this example settings,
             #    1st timer fires every 0.25 seconds in 0.25 seconds. (0.25, 0.5, 0.75, 1.0, ...)
             #    2nd timer every 0.5 seconds in 0.5 seconds. (0.5, 1.0, 1.5, 2.0, ...)
             #    3rd timer every 0.75 seconds in 0.75 seconds. (0.75, 1.5, 2.25, 3.0, ...)
             #
             #    In 0.25 seconds, only 1st timer fires.
             #    In 0.5 seconds, 1st timer and 2nd timer fires at once.
             #    In 0.75 seconds, 1st timer and 3rd timer fires at once.
             #    In 1.5 seconds, 1st timer, 2nd timer and 3rd timer fires at once.
             #
             # If a timer file descriptor is signaled more than once since
             # the last os.read() call, os.read() returns the number of signaled
             # as host order of class bytes.
             print(f"Signaled events={events}")
             for fd, event in events:
                 if event & select.EPOLLIN:
                     if fd == sock.fileno():
                         # Check if there is a connection request.
                         print(f"Accepting connection {fd}")
                         conn, addr = sock.accept()
                         conn.setblocking(False)
                         print(f"Accepted connection {conn} from {addr}")
                         ep.register(conn, select.EPOLLIN)
                     elif conn and fd == conn.fileno():
                         # Check if there is data to read.
                         print(f"Reading data {fd}")
                         data = conn.recv(1024)
                         if data:
                             # You should catch UnicodeDecodeError exception for safety.
                             cmd = data.decode()
                             if cmd.startswith("stop"):
                                 print(f"Stopping server")
                                 is_active = False
                             else:
                                 print(f"Unknown command: {cmd}")
                         else:
                             # No more data, close connection
                             print(f"Closing connection {fd}")
                             ep.unregister(conn)
                             conn.close()
                             conn = None
                     elif fd in fds:
                         print(f"Reading timer {fd}")
                         count = int.from_bytes(os.read(fd, 8), byteorder=sys.byteorder)
                         print(f"Timer {fds.index(fd) + 1} expired {count} times")
                     else:
                         print(f"Unknown file descriptor {fd}")
     finally:
         for fd in fds:
             ep.unregister(fd)
             os.close(fd)
         ep.close()

This example shows how *note select(): fa2. can be used with timer file
descriptors to wait until the file descriptor is ready for reading:

     import os, time, select, socket, sys

     # In this example, use loopback address to send "stop" command to the server.
     #
     # $ telnet 127.0.0.1 1234
     # Trying 127.0.0.1...
     # Connected to 127.0.0.1.
     # Escape character is '^]'.
     # stop
     # Connection closed by foreign host.
     #
     sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     sock.bind(("127.0.0.1", 1234))
     sock.setblocking(False)
     sock.listen(1)

     # Create timer file descriptors in non-blocking mode.
     num = 3
     fds = [os.timerfd_create(time.CLOCK_REALTIME, flags=os.TFD_NONBLOCK)
            for _ in range(num)]
     select_fds = fds + [sock]

     # Start the timers with os.timerfd_settime() in seconds.
     # Timer 1 fires every 0.25 seconds; timer 2 every 0.5 seconds; etc
     for i, fd in enumerate(fds, start=1):
        os.timerfd_settime(fd, initial=i/4, interval=i/4)

     timeout = 3
     try:
         conn = None
         is_active = True
         while is_active:
            # Wait for the timer to expire for 3 seconds.
            # select.select() returns a list of file descriptors or objects.
            rfd, wfd, xfd = select.select(select_fds, select_fds, select_fds, timeout)
            for fd in rfd:
                if fd == sock:
                    # Check if there is a connection request.
                    print(f"Accepting connection {fd}")
                    conn, addr = sock.accept()
                    conn.setblocking(False)
                    print(f"Accepted connection {conn} from {addr}")
                    select_fds.append(conn)
                elif conn and fd == conn:
                    # Check if there is data to read.
                    print(f"Reading data {fd}")
                    data = conn.recv(1024)
                    if data:
                        # You should catch UnicodeDecodeError exception for safety.
                        cmd = data.decode()
                        if cmd.startswith("stop"):
                            print(f"Stopping server")
                            is_active = False
                        else:
                            print(f"Unknown command: {cmd}")
                    else:
                        # No more data, close connection
                        print(f"Closing connection {fd}")
                        select_fds.remove(conn)
                        conn.close()
                        conn = None
                elif fd in fds:
                    print(f"Reading timer {fd}")
                    count = int.from_bytes(os.read(fd, 8), byteorder=sys.byteorder)
                    print(f"Timer {fds.index(fd) + 1} expired {count} times")
                else:
                    print(f"Unknown file descriptor {fd}")
     finally:
         for fd in fds:
            os.close(fd)
         sock.close()
         sock = None


File: python.info,  Node: The Python 2 3 Method Resolution Order,  Next: Python support for free threading,  Prev: timer file descriptor HOWTO,  Up: Python HOWTOs

9.21 The Python 2.3 Method Resolution Order
===========================================

     Nota: This is a historical document, provided as an appendix to the
     official documentation.  The Method Resolution Order discussed here
     was 'introduced' in Python 2.3, but it is still used in later
     versions – including Python 3.

By Michele Simionato(1).


Abstract: 'This document is intended for Python programmers who want to
understand the C3 Method Resolution Order used in Python 2.3.  Although
it is not intended for newbies, it is quite pedagogical with many worked
out examples.  I am not aware of other publicly available documents with
the same scope, therefore it should be useful.'

Disclaimer:

     'I donate this document to the Python Software Foundation, under
     the Python 2.3 license.  As usual in these circumstances, I warn
     the reader that what follows' should 'be correct, but I don’t give
     any warranty.  Use it at your own risk and peril!'

Acknowledgments:

     'All the people of the Python mailing list who sent me their
     support.  Paul Foley who pointed out various imprecisions and made
     me to add the part on local precedence ordering.  David Goodger for
     help with the formatting in reStructuredText.  David Mertz for help
     with the editing.  Finally, Guido van Rossum who enthusiastically
     added this document to the official Python 2.3 home-page.'

* Menu:

* The beginning::
* The C3 Method Resolution Order::
* Examples: Examples<42>.
* Bad Method Resolution Orders::
* The end::
* Resources::

   ---------- Footnotes ----------

   (1) https://www.phyast.pitt.edu/~micheles/


File: python.info,  Node: The beginning,  Next: The C3 Method Resolution Order,  Up: The Python 2 3 Method Resolution Order

9.21.1 The beginning
--------------------

     'Felix qui potuit rerum cognoscere causas' – Virgilius

Everything started with a post by Samuele Pedroni to the Python
development mailing list (1).  In his post, Samuele showed that the
Python 2.2 method resolution order is not monotonic and he proposed to
replace it with the C3 method resolution order.  Guido agreed with his
arguments and therefore now Python 2.3 uses C3.  The C3 method itself
has nothing to do with Python, since it was invented by people working
on Dylan and it is described in a paper intended for lispers (2).  The
present paper gives a (hopefully) readable discussion of the C3
algorithm for Pythonistas who want to understand the reasons for the
change.

First of all, let me point out that what I am going to say only applies
to the 'new style classes' introduced in Python 2.2: 'classic classes'
maintain their old method resolution order, depth first and then left to
right.  Therefore, there is no breaking of old code for classic classes;
and even if in principle there could be breaking of code for Python 2.2
new style classes, in practice the cases in which the C3 resolution
order differs from the Python 2.2 method resolution order are so rare
that no real breaking of code is expected.  Therefore:

     'Don’t be scared!'

Moreover, unless you make strong use of multiple inheritance and you
have non-trivial hierarchies, you don’t need to understand the C3
algorithm, and you can easily skip this paper.  On the other hand, if
you really want to know how multiple inheritance works, then this paper
is for you.  The good news is that things are not as complicated as you
might expect.

Let me begin with some basic definitions.

  1. Given a class C in a complicated multiple inheritance hierarchy, it
     is a non-trivial task to specify the order in which methods are
     overridden, i.e.  to specify the order of the ancestors of C.

  2. The list of the ancestors of a class C, including the class itself,
     ordered from the nearest ancestor to the furthest, is called the
     class precedence list or the 'linearization' of C.

  3. The 'Method Resolution Order' (MRO) is the set of rules that
     construct the linearization.  In the Python literature, the idiom
     «the MRO of C» is also used as a synonymous for the linearization
     of the class C.

  4. For instance, in the case of single inheritance hierarchy, if C is
     a subclass of C1, and C1 is a subclass of C2, then the
     linearization of C is simply the list [C, C1 , C2].  However, with
     multiple inheritance hierarchies, the construction of the
     linearization is more cumbersome, since it is more difficult to
     construct a linearization that respects 'local precedence ordering'
     and 'monotonicity'.

  5. I will discuss the local precedence ordering later, but I can give
     the definition of monotonicity here.  A MRO is monotonic when the
     following is true: 'if C1 precedes C2 in the linearization of C,
     then C1 precedes C2 in the linearization of any subclass of C'.
     Otherwise, the innocuous operation of deriving a new class could
     change the resolution order of methods, potentially introducing
     very subtle bugs.  Examples where this happens will be shown later.

  6. Not all classes admit a linearization.  There are cases, in
     complicated hierarchies, where it is not possible to derive a class
     such that its linearization respects all the desired properties.

Here I give an example of this situation.  Consider the hierarchy

     >>> O = object
     >>> class X(O): pass
     >>> class Y(O): pass
     >>> class A(X,Y): pass
     >>> class B(Y,X): pass

which can be represented with the following inheritance graph, where I
have denoted with O the ‘object’ class, which is the beginning of any
hierarchy for new style classes:

           -----------
          |           |
          |    O      |
          |  /   \    |
           - X    Y  /
             |  / | /
             | /  |/
             A    B
             \   /
               ?

In this case, it is not possible to derive a new class C from A and B,
since X precedes Y in A, but Y precedes X in B, therefore the method
resolution order would be ambiguous in C.

Python 2.3 raises an exception in this situation (TypeError: MRO
conflict among bases Y, X) forbidding the naive programmer from creating
ambiguous hierarchies.  Python 2.2 instead does not raise an exception,
but chooses an 'ad hoc' ordering (CABXYO in this case).

   ---------- Footnotes ----------

   (1) The thread on python-dev started by Samuele Pedroni:
‘https://mail.python.org/pipermail/python-dev/2002-October/029035.html’

   (2) The paper 'A Monotonic Superclass Linearization for Dylan':
‘https://doi.org/10.1145/236337.236343’


File: python.info,  Node: The C3 Method Resolution Order,  Next: Examples<42>,  Prev: The beginning,  Up: The Python 2 3 Method Resolution Order

9.21.2 The C3 Method Resolution Order
-------------------------------------

Let me introduce a few simple notations which will be useful for the
following discussion.  I will use the shortcut notation:

     C1 C2 ... CN

to indicate the list of classes [C1, C2, … , CN].

The 'head' of the list is its first element:

     head = C1

whereas the 'tail' is the rest of the list:

     tail = C2 ... CN.

I shall also use the notation:

     C + (C1 C2 ... CN) = C C1 C2 ... CN

to denote the sum of the lists [C] + [C1, C2, … ,CN].

Now I can explain how the MRO works in Python 2.3.

Consider a class C in a multiple inheritance hierarchy, with C
inheriting from the base classes B1, B2, … , BN. We want to compute the
linearization L[C] of the class C. The rule is the following:

     'the linearization of C is the sum of C plus the merge of the
     linearizations of the parents and the list of the parents.'

In symbolic notation:

     L[C(B1 ... BN)] = C + merge(L[B1] ... L[BN], B1 ... BN)

In particular, if C is the ‘object’ class, which has no parents, the
linearization is trivial:

     L[object] = object.

However, in general one has to compute the merge according to the
following prescription:

     'take the head of the first list, i.e L[B1][0]; if this head is not
     in the tail of any of the other lists, then add it to the
     linearization of C and remove it from the lists in the merge,
     otherwise look at the head of the next list and take it, if it is a
     good head.  Then repeat the operation until all the class are
     removed or it is impossible to find good heads.  In this case, it
     is impossible to construct the merge, Python 2.3 will refuse to
     create the class C and will raise an exception.'

This prescription ensures that the merge operation 'preserves' the
ordering, if the ordering can be preserved.  On the other hand, if the
order cannot be preserved (as in the example of serious order
disagreement discussed above) then the merge cannot be computed.

The computation of the merge is trivial if C has only one parent (single
inheritance); in this case:

     L[C(B)] = C + merge(L[B],B) = C + L[B]

However, in the case of multiple inheritance things are more cumbersome
and I don’t expect you can understand the rule without a couple of
examples ;-)


File: python.info,  Node: Examples<42>,  Next: Bad Method Resolution Orders,  Prev: The C3 Method Resolution Order,  Up: The Python 2 3 Method Resolution Order

9.21.3 Examples
---------------

First example.  Consider the following hierarchy:

     >>> O = object
     >>> class F(O): pass
     >>> class E(O): pass
     >>> class D(O): pass
     >>> class C(D,F): pass
     >>> class B(D,E): pass
     >>> class A(B,C): pass

In this case the inheritance graph can be drawn as:

                                    6
                                   ---
          Level 3                 | O |                  (more general)
                                /  ---  \
                               /    |    \                      |
                              /     |     \                     |
                             /      |      \                    |
                            ---    ---    ---                   |
          Level 2        3 | D | 4| E |  | F | 5                |
                            ---    ---    ---                   |
                             \  \ _ /       |                   |
                              \    / \ _    |                   |
                               \  /      \  |                   |
                                ---      ---                    |
          Level 1            1 | B |    | C | 2                 |
                                ---      ---                    |
                                  \      /                      |
                                   \    /                      \ /
                                     ---
          Level 0                 0 | A |                (more specialized)
                                     ---

The linearizations of O,D,E and F are trivial:

     L[O] = O
     L[D] = D O
     L[E] = E O
     L[F] = F O

The linearization of B can be computed as:

     L[B] = B + merge(DO, EO, DE)

We see that D is a good head, therefore we take it and we are reduced to
compute ‘merge(O,EO,E)’.  Now O is not a good head, since it is in the
tail of the sequence EO. In this case the rule says that we have to skip
to the next sequence.  Then we see that E is a good head; we take it and
we are reduced to compute ‘merge(O,O)’ which gives O. Therefore:

     L[B] =  B D E O

Using the same procedure one finds:

     L[C] = C + merge(DO,FO,DF)
          = C + D + merge(O,FO,F)
          = C + D + F + merge(O,O)
          = C D F O

Now we can compute:

     L[A] = A + merge(BDEO,CDFO,BC)
          = A + B + merge(DEO,CDFO,C)
          = A + B + C + merge(DEO,DFO)
          = A + B + C + D + merge(EO,FO)
          = A + B + C + D + E + merge(O,FO)
          = A + B + C + D + E + F + merge(O,O)
          = A B C D E F O

In this example, the linearization is ordered in a pretty nice way
according to the inheritance level, in the sense that lower levels (i.e.
more specialized classes) have higher precedence (see the inheritance
graph).  However, this is not the general case.

I leave as an exercise for the reader to compute the linearization for
my second example:

     >>> O = object
     >>> class F(O): pass
     >>> class E(O): pass
     >>> class D(O): pass
     >>> class C(D,F): pass
     >>> class B(E,D): pass
     >>> class A(B,C): pass

The only difference with the previous example is the change B(D,E) –>
B(E,D); however even such a little modification completely changes the
ordering of the hierarchy:

                                     6
                                    ---
          Level 3                  | O |
                                 /  ---  \
                                /    |    \
                               /     |     \
                              /      |      \
                            ---     ---    ---
          Level 2        2 | E | 4 | D |  | F | 5
                            ---     ---    ---
                             \      / \     /
                              \    /   \   /
                               \  /     \ /
                                ---     ---
          Level 1            1 | B |   | C | 3
                                ---     ---
                                 \       /
                                  \     /
                                    ---
          Level 0                0 | A |
                                    ---

Notice that the class E, which is in the second level of the hierarchy,
precedes the class C, which is in the first level of the hierarchy, i.e.
E is more specialized than C, even if it is in a higher level.

A lazy programmer can obtain the MRO directly from Python 2.2, since in
this case it coincides with the Python 2.3 linearization.  It is enough
to invoke the *note mro(): 2360. method of class A:

     >>> A.mro()
     [<class 'A'>, <class 'B'>, <class 'E'>,
     <class 'C'>, <class 'D'>, <class 'F'>,
     <class 'object'>]

Finally, let me consider the example discussed in the first section,
involving a serious order disagreement.  In this case, it is
straightforward to compute the linearizations of O, X, Y, A and B:

          L[O] = 0
          L[X] = X O
          L[Y] = Y O
          L[A] = A X Y O
          L[B] = B Y X O

However, it is impossible to compute the linearization for a class C
that inherits from A and B:

     L[C] = C + merge(AXYO, BYXO, AB)
          = C + A + merge(XYO, BYXO, B)
          = C + A + B + merge(XYO, YXO)

At this point we cannot merge the lists XYO and YXO, since X is in the
tail of YXO whereas Y is in the tail of XYO: therefore there are no good
heads and the C3 algorithm stops.  Python 2.3 raises an error and
refuses to create the class C.


File: python.info,  Node: Bad Method Resolution Orders,  Next: The end,  Prev: Examples<42>,  Up: The Python 2 3 Method Resolution Order

9.21.4 Bad Method Resolution Orders
-----------------------------------

A MRO is 'bad' when it breaks such fundamental properties as local
precedence ordering and monotonicity.  In this section, I will show that
both the MRO for classic classes and the MRO for new style classes in
Python 2.2 are bad.

It is easier to start with the local precedence ordering.  Consider the
following example:

     >>> F=type('Food',(),{'remember2buy':'spam'})
     >>> E=type('Eggs',(F,),{'remember2buy':'eggs'})
     >>> G=type('GoodFood',(F,E),{}) # under Python 2.3 this is an error!

with inheritance diagram

                       O
                       |
          (buy spam)   F
                       | \
                       | E   (buy eggs)
                       | /
                       G

                (buy eggs or spam ?)

We see that class G inherits from F and E, with F 'before' E: therefore
we would expect the attribute 'G.remember2buy' to be inherited by
'F.remember2buy' and not by 'E.remember2buy': nevertheless Python 2.2
gives

     >>> G.remember2buy
     'eggs'

This is a breaking of local precedence ordering since the order in the
local precedence list, i.e.  the list of the parents of G, is not
preserved in the Python 2.2 linearization of G:

     L[G,P22]= G E F object   # F *follows* E

One could argue that the reason why F follows E in the Python 2.2
linearization is that F is less specialized than E, since F is the
superclass of E; nevertheless the breaking of local precedence ordering
is quite non-intuitive and error prone.  This is particularly true since
it is a different from old style classes:

     >>> class F: remember2buy='spam'
     >>> class E(F): remember2buy='eggs'
     >>> class G(F,E): pass
     >>> G.remember2buy
     'spam'

In this case the MRO is GFEF and the local precedence ordering is
preserved.

As a general rule, hierarchies such as the previous one should be
avoided, since it is unclear if F should override E or vice-versa.
Python 2.3 solves the ambiguity by raising an exception in the creation
of class G, effectively stopping the programmer from generating
ambiguous hierarchies.  The reason for that is that the C3 algorithm
fails when the merge:

     merge(FO,EFO,FE)

cannot be computed, because F is in the tail of EFO and E is in the tail
of FE.

The real solution is to design a non-ambiguous hierarchy, i.e.  to
derive G from E and F (the more specific first) and not from F and E; in
this case the MRO is GEF without any doubt.

                     O
                     |
                     F (spam)
                   / |
          (eggs)   E |
                   \ |
                     G
                       (eggs, no doubt)

Python 2.3 forces the programmer to write good hierarchies (or, at
least, less error-prone ones).

On a related note, let me point out that the Python 2.3 algorithm is
smart enough to recognize obvious mistakes, as the duplication of
classes in the list of parents:

     >>> class A(object): pass
     >>> class C(A,A): pass # error
     Traceback (most recent call last):
       File "<stdin>", line 1, in ?
     TypeError: duplicate base class A

Python 2.2 (both for classic classes and new style classes) in this
situation, would not raise any exception.

Finally, I would like to point out two lessons we have learned from this
example:

  1. despite the name, the MRO determines the resolution order of
     attributes, not only of methods;

  2. the default food for Pythonistas is spam !  (but you already knew
     that ;-)

Having discussed the issue of local precedence ordering, let me now
consider the issue of monotonicity.  My goal is to show that neither the
MRO for classic classes nor that for Python 2.2 new style classes is
monotonic.

To prove that the MRO for classic classes is non-monotonic is rather
trivial, it is enough to look at the diamond diagram:

             C
            / \
           /   \
          A     B
           \   /
            \ /
             D

One easily discerns the inconsistency:

     L[B,P21] = B C        # B precedes C : B's methods win
     L[D,P21] = D A C B C  # B follows C  : C's methods win!

On the other hand, there are no problems with the Python 2.2 and 2.3
MROs, they give both:

     L[D] = D A B C

Guido points out in his essay (1) that the classic MRO is not so bad in
practice, since one can typically avoids diamonds for classic classes.
But all new style classes inherit from ‘object’, therefore diamonds are
unavoidable and inconsistencies shows up in every multiple inheritance
graph.

The MRO of Python 2.2 makes breaking monotonicity difficult, but not
impossible.  The following example, originally provided by Samuele
Pedroni, shows that the MRO of Python 2.2 is non-monotonic:

     >>> class A(object): pass
     >>> class B(object): pass
     >>> class C(object): pass
     >>> class D(object): pass
     >>> class E(object): pass
     >>> class K1(A,B,C): pass
     >>> class K2(D,B,E): pass
     >>> class K3(D,A):   pass
     >>> class Z(K1,K2,K3): pass

Here are the linearizations according to the C3 MRO (the reader should
verify these linearizations as an exercise and draw the inheritance
diagram ;-)

     L[A] = A O
     L[B] = B O
     L[C] = C O
     L[D] = D O
     L[E] = E O
     L[K1]= K1 A B C O
     L[K2]= K2 D B E O
     L[K3]= K3 D A O
     L[Z] = Z K1 K2 K3 D A B C E O

Python 2.2 gives exactly the same linearizations for A, B, C, D, E, K1,
K2 and K3, but a different linearization for Z:

     L[Z,P22] = Z K1 K3 A K2 D B C E O

It is clear that this linearization is 'wrong', since A comes before D
whereas in the linearization of K3 A comes 'after' D. In other words, in
K3 methods derived by D override methods derived by A, but in Z, which
still is a subclass of K3, methods derived by A override methods derived
by D! This is a violation of monotonicity.  Moreover, the Python 2.2
linearization of Z is also inconsistent with local precedence ordering,
since the local precedence list of the class Z is [K1, K2, K3] (K2
precedes K3), whereas in the linearization of Z K2 'follows' K3.  These
problems explain why the 2.2 rule has been dismissed in favor of the C3
rule.

   ---------- Footnotes ----------

   (1) Guido van Rossum’s essay, 'Unifying types and classes in Python
2.2':
‘https://web.archive.org/web/20140210194412/http://www.python.org/download/releases/2.2.2/descrintro’


File: python.info,  Node: The end,  Next: Resources,  Prev: Bad Method Resolution Orders,  Up: The Python 2 3 Method Resolution Order

9.21.5 The end
--------------

This section is for the impatient reader, who skipped all the previous
sections and jumped immediately to the end.  This section is for the
lazy programmer too, who didn’t want to exercise her/his brain.
Finally, it is for the programmer with some hubris, otherwise s/he would
not be reading a paper on the C3 method resolution order in multiple
inheritance hierarchies ;-) These three virtues taken all together (and
'not' separately) deserve a prize: the prize is a short Python 2.2
script that allows you to compute the 2.3 MRO without risk to your
brain.  Simply change the last line to play with the various examples I
have discussed in this paper.:

     #<mro.py>

     """C3 algorithm by Samuele Pedroni (with readability enhanced by me)."""

     class __metaclass__(type):
         "All classes are metamagically modified to be nicely printed"
         __repr__ = lambda cls: cls.__name__

     class ex_2:
         "Serious order disagreement" #From Guido
         class O: pass
         class X(O): pass
         class Y(O): pass
         class A(X,Y): pass
         class B(Y,X): pass
         try:
             class Z(A,B): pass #creates Z(A,B) in Python 2.2
         except TypeError:
             pass # Z(A,B) cannot be created in Python 2.3

     class ex_5:
         "My first example"
         class O: pass
         class F(O): pass
         class E(O): pass
         class D(O): pass
         class C(D,F): pass
         class B(D,E): pass
         class A(B,C): pass

     class ex_6:
         "My second example"
         class O: pass
         class F(O): pass
         class E(O): pass
         class D(O): pass
         class C(D,F): pass
         class B(E,D): pass
         class A(B,C): pass

     class ex_9:
         "Difference between Python 2.2 MRO and C3" #From Samuele
         class O: pass
         class A(O): pass
         class B(O): pass
         class C(O): pass
         class D(O): pass
         class E(O): pass
         class K1(A,B,C): pass
         class K2(D,B,E): pass
         class K3(D,A): pass
         class Z(K1,K2,K3): pass

     def merge(seqs):
         print '\n\nCPL[%s]=%s' % (seqs[0][0],seqs),
         res = []; i=0
         while 1:
           nonemptyseqs=[seq for seq in seqs if seq]
           if not nonemptyseqs: return res
           i+=1; print '\n',i,'round: candidates...',
           for seq in nonemptyseqs: # find merge candidates among seq heads
               cand = seq[0]; print ' ',cand,
               nothead=[s for s in nonemptyseqs if cand in s[1:]]
               if nothead: cand=None #reject candidate
               else: break
           if not cand: raise "Inconsistent hierarchy"
           res.append(cand)
           for seq in nonemptyseqs: # remove cand
               if seq[0] == cand: del seq[0]

     def mro(C):
         "Compute the class precedence list (mro) according to C3"
         return merge([[C]]+map(mro,C.__bases__)+[list(C.__bases__)])

     def print_mro(C):
         print '\nMRO[%s]=%s' % (C,mro(C))
         print '\nP22 MRO[%s]=%s' % (C,C.mro())

     print_mro(ex_9.Z)

     #</mro.py>

That’s all folks,

     enjoy !


File: python.info,  Node: Resources,  Prev: The end,  Up: The Python 2 3 Method Resolution Order

9.21.6 Resources
----------------


File: python.info,  Node: Python support for free threading,  Next: C API Extension Support for Free Threading,  Prev: The Python 2 3 Method Resolution Order,  Up: Python HOWTOs

9.22 Python support for free threading
======================================

Starting with the 3.13 release, CPython has support for a build of
Python called *note free threading: 1f4. where the *note global
interpreter lock: 474. (GIL) is disabled.  Free-threaded execution
allows for full utilization of the available processing power by running
threads in parallel on available CPU cores.  While not all software will
benefit from this automatically, programs designed with threading in
mind will run faster on multi-core hardware.

Some third-party packages, in particular ones with an *note extension
module: 223a, may not be ready for use in a free-threaded build, and
will re-enable the *note GIL: 164.

This document describes the implications of free threading for Python
code.  See *note C API Extension Support for Free Threading: 5836. for
information on how to write C extensions that support the free-threaded
build.

Vedi anche
..........

PEP 703(1) – Making the Global Interpreter Lock Optional in CPython for
an overall description of free-threaded Python.

* Menu:

* Installation: Installation<2>.
* Identifying free-threaded Python::
* The global interpreter lock in free-threaded Python::
* Thread safety::
* Known limitations::
* Behavioral changes::

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0703/


File: python.info,  Node: Installation<2>,  Next: Identifying free-threaded Python,  Up: Python support for free threading

9.22.1 Installation
-------------------

Starting with Python 3.13, the official macOS and Windows installers
optionally support installing free-threaded Python binaries.  The
installers are available at ‘https://www.python.org/downloads/’.

For information on other platforms, see the Installing a Free-Threaded
Python(1), a community-maintained installation guide for installing
free-threaded Python.

When building CPython from source, the *note -disable-gil: 49a.
configure option should be used to build a free-threaded Python
interpreter.

   ---------- Footnotes ----------

   (1) https://py-free-threading.github.io/installing-cpython/


File: python.info,  Node: Identifying free-threaded Python,  Next: The global interpreter lock in free-threaded Python,  Prev: Installation<2>,  Up: Python support for free threading

9.22.2 Identifying free-threaded Python
---------------------------------------

To check if the current interpreter supports free-threading, *note
python -VV: 49c. and *note sys.version: 49d. contain «free-threading
build».  The new *note sys._is_gil_enabled(): 490e. function can be used
to check whether the GIL is actually disabled in the running process.

The ‘sysconfig.get_config_var("Py_GIL_DISABLED")’ configuration variable
can be used to determine whether the build supports free threading.  If
the variable is set to ‘1’, then the build supports free threading.
This is the recommended mechanism for decisions related to the build
configuration.


File: python.info,  Node: The global interpreter lock in free-threaded Python,  Next: Thread safety,  Prev: Identifying free-threaded Python,  Up: Python support for free threading

9.22.3 The global interpreter lock in free-threaded Python
----------------------------------------------------------

Free-threaded builds of CPython support optionally running with the GIL
enabled at runtime using the environment variable *note PYTHON_GIL: 49b.
or the command-line option *note -X gil: 16f.

The GIL may also automatically be enabled when importing a C-API
extension module that is not explicitly marked as supporting free
threading.  A warning will be printed in this case.

In addition to individual package documentation, the following websites
track the status of popular packages support for free threading:

   * ‘https://py-free-threading.github.io/tracking/’

   * ‘https://hugovk.github.io/free-threaded-wheels/’


File: python.info,  Node: Thread safety,  Next: Known limitations,  Prev: The global interpreter lock in free-threaded Python,  Up: Python support for free threading

9.22.4 Thread safety
--------------------

The free-threaded build of CPython aims to provide similar thread-safety
behavior at the Python level to the default GIL-enabled build.  Built-in
types like *note dict: 183, *note list: 24d, and *note set: 184. use
internal locks to protect against concurrent modifications in ways that
behave similarly to the GIL. However, Python has not historically
guaranteed specific behavior for concurrent modifications to these
built-in types, so this should be treated as a description of the
current implementation, not a guarantee of current or future behavior.

     Nota: It’s recommended to use the *note threading.Lock: 19dc. or
     other synchronization primitives instead of relying on the internal
     locks of built-in types, when possible.


File: python.info,  Node: Known limitations,  Next: Behavioral changes,  Prev: Thread safety,  Up: Python support for free threading

9.22.5 Known limitations
------------------------

This section describes known limitations of the free-threaded CPython
build.

* Menu:

* Immortalization::
* Frame objects: Frame objects<2>.
* Iterators: Iterators<2>.
* Single-threaded performance::


File: python.info,  Node: Immortalization,  Next: Frame objects<2>,  Up: Known limitations

9.22.5.1 Immortalization
........................

In the free-threaded build, some objects are *note immortal: 290.
Immortal objects are not deallocated and have reference counts that are
never modified.  This is done to avoid reference count contention that
would prevent efficient multi-threaded scaling.

As of the 3.14 release, immortalization is limited to:

   * Code constants: numeric literals, string literals, and tuple
     literals composed of other constants.

   * Strings interned by *note sys.intern(): 14e3.


File: python.info,  Node: Frame objects<2>,  Next: Iterators<2>,  Prev: Immortalization,  Up: Known limitations

9.22.5.2 Frame objects
......................

It is not safe to access *note frame.f_locals: 4a6. from a *note frame:
8f0. object if that frame is currently executing in another thread, and
doing so may crash the interpreter.


File: python.info,  Node: Iterators<2>,  Next: Single-threaded performance,  Prev: Frame objects<2>,  Up: Known limitations

9.22.5.3 Iterators
..................

It is generally not thread-safe to access the same iterator object from
multiple threads concurrently, and threads may see duplicate or missing
elements.


File: python.info,  Node: Single-threaded performance,  Prev: Iterators<2>,  Up: Known limitations

9.22.5.4 Single-threaded performance
....................................

The free-threaded build has additional overhead when executing Python
code compared to the default GIL-enabled build.  The amount of overhead
depends on the workload and hardware.  On the pyperformance benchmark
suite, the average overhead ranges from about 1% on macOS aarch64 to 8%
on x86-64 Linux systems.


File: python.info,  Node: Behavioral changes,  Prev: Known limitations,  Up: Python support for free threading

9.22.6 Behavioral changes
-------------------------

This section describes CPython behavioural changes with the
free-threaded build.

* Menu:

* Context variables::
* Warning filters::


File: python.info,  Node: Context variables,  Next: Warning filters,  Up: Behavioral changes

9.22.6.1 Context variables
..........................

In the free-threaded build, the flag *note thread_inherit_context: 175.
is set to true by default which causes threads created with *note
threading.Thread: 176. to start with a copy of the *note Context(): 177.
of the caller of *note start(): 178.  In the default GIL-enabled build,
the flag defaults to false so threads start with an empty *note
Context(): 177.


File: python.info,  Node: Warning filters,  Prev: Context variables,  Up: Behavioral changes

9.22.6.2 Warning filters
........................

In the free-threaded build, the flag *note context_aware_warnings: 18a.
is set to true by default.  In the default GIL-enabled build, the flag
defaults to false.  If the flag is true then the *note
warnings.catch_warnings: 179. context manager uses a context variable
for warning filters.  If the flag is false then *note catch_warnings:
179. modifies the global filters list, which is not thread-safe.  See
the *note warnings: 118. module for more details.


File: python.info,  Node: C API Extension Support for Free Threading,  Next: Remote debugging attachment protocol,  Prev: Python support for free threading,  Up: Python HOWTOs

9.23 C API Extension Support for Free Threading
===============================================

Starting with the 3.13 release, CPython has support for running with the
*note global interpreter lock: 474. (GIL) disabled in a configuration
called *note free threading: 1f4.  This document describes how to adapt
C API extensions to support free threading.

* Menu:

* Identifying the Free-Threaded Build in C::
* Module Initialization::
* General API Guidelines::
* Borrowed References::
* Memory Allocation APIs::
* Thread State and GIL APIs::
* Protecting Internal Extension State::
* Critical Sections::
* Building Extensions for the Free-Threaded Build::


File: python.info,  Node: Identifying the Free-Threaded Build in C,  Next: Module Initialization,  Up: C API Extension Support for Free Threading

9.23.1 Identifying the Free-Threaded Build in C
-----------------------------------------------

The CPython C API exposes the ‘Py_GIL_DISABLED’ macro: in the
free-threaded build it’s defined to ‘1’, and in the regular build it’s
not defined.  You can use it to enable code that only runs under the
free-threaded build:

     #ifdef Py_GIL_DISABLED
     /* code that only runs in the free-threaded build */
     #endif

     Nota: On Windows, this macro is not defined automatically, but must
     be specified to the compiler when building.  The *note
     sysconfig.get_config_var(): 174. function can be used to determine
     whether the current running interpreter had the macro defined.


File: python.info,  Node: Module Initialization,  Next: General API Guidelines,  Prev: Identifying the Free-Threaded Build in C,  Up: C API Extension Support for Free Threading

9.23.2 Module Initialization
----------------------------

Extension modules need to explicitly indicate that they support running
with the GIL disabled; otherwise importing the extension will raise a
warning and enable the GIL at runtime.

There are two ways to indicate that an extension module supports running
with the GIL disabled depending on whether the extension uses
multi-phase or single-phase initialization.

* Menu:

* Multi-Phase Initialization::
* Single-Phase Initialization::


File: python.info,  Node: Multi-Phase Initialization,  Next: Single-Phase Initialization,  Up: Module Initialization

9.23.2.1 Multi-Phase Initialization
...................................

Extensions that use multi-phase initialization (i.e., *note
PyModuleDef_Init(): 4e8c.) should add a *note Py_mod_gil: 483. slot in
the module definition.  If your extension supports older versions of
CPython, you should guard the slot with a *note PY_VERSION_HEX: 382.
check.

     static struct PyModuleDef_Slot module_slots[] = {
         ...
     #if PY_VERSION_HEX >= 0x030D0000
         {Py_mod_gil, Py_MOD_GIL_NOT_USED},
     #endif
         {0, NULL}
     };

     static struct PyModuleDef moduledef = {
         PyModuleDef_HEAD_INIT,
         .m_slots = module_slots,
         ...
     };


File: python.info,  Node: Single-Phase Initialization,  Prev: Multi-Phase Initialization,  Up: Module Initialization

9.23.2.2 Single-Phase Initialization
....................................

Extensions that use single-phase initialization (i.e., *note
PyModule_Create(): 51ef.) should call *note PyUnstable_Module_SetGIL():
49e. to indicate that they support running with the GIL disabled.  The
function is only defined in the free-threaded build, so you should guard
the call with ‘#ifdef Py_GIL_DISABLED’ to avoid compilation errors in
the regular build.

     static struct PyModuleDef moduledef = {
         PyModuleDef_HEAD_INIT,
         ...
     };

     PyMODINIT_FUNC
     PyInit_mymodule(void)
     {
         PyObject *m = PyModule_Create(&moduledef);
         if (m == NULL) {
             return NULL;
         }
     #ifdef Py_GIL_DISABLED
         PyUnstable_Module_SetGIL(m, Py_MOD_GIL_NOT_USED);
     #endif
         return m;
     }


File: python.info,  Node: General API Guidelines,  Next: Borrowed References,  Prev: Module Initialization,  Up: C API Extension Support for Free Threading

9.23.3 General API Guidelines
-----------------------------

Most of the C API is thread-safe, but there are some exceptions.

   * 'Struct Fields': Accessing fields in Python C API objects or
     structs directly is not thread-safe if the field may be
     concurrently modified.

   * 'Macros': Accessor macros like *note PyList_GET_ITEM: 4f37, *note
     PyList_SET_ITEM: 62f, and macros like *note
     PySequence_Fast_GET_SIZE: 3ca. that use the object returned by
     *note PySequence_Fast(): 188a. do not perform any error checking or
     locking.  These macros are not thread-safe if the container object
     may be modified concurrently.

   * 'Borrowed References': C API functions that return *note borrowed
     references: 3d7. may not be thread-safe if the containing object is
     modified concurrently.  See the section on *note borrowed
     references: 584b. for more information.

* Menu:

* Container Thread Safety::


File: python.info,  Node: Container Thread Safety,  Up: General API Guidelines

9.23.3.1 Container Thread Safety
................................

Containers like *note PyListObject: 5280, *note PyDictObject: 64f, and
*note PySetObject: 53a2. perform internal locking in the free-threaded
build.  For example, the *note PyList_Append(): 5017. will lock the list
before appending an item.

* Menu:

* PyDict_Next::


File: python.info,  Node: PyDict_Next,  Up: Container Thread Safety

9.23.3.2 ‘PyDict_Next’
......................

A notable exception is *note PyDict_Next(): 1977, which does not lock
the dictionary.  You should use *note Py_BEGIN_CRITICAL_SECTION: 5384.
to protect the dictionary while iterating over it if the dictionary may
be concurrently modified:

     Py_BEGIN_CRITICAL_SECTION(dict);
     PyObject *key, *value;
     Py_ssize_t pos = 0;
     while (PyDict_Next(dict, &pos, &key, &value)) {
         ...
     }
     Py_END_CRITICAL_SECTION();


File: python.info,  Node: Borrowed References,  Next: Memory Allocation APIs,  Prev: General API Guidelines,  Up: C API Extension Support for Free Threading

9.23.4 Borrowed References
--------------------------

Some C API functions return *note borrowed references: 3d7.  These APIs
are not thread-safe if the containing object is modified concurrently.
For example, it’s not safe to use *note PyList_GetItem(): 5ff. if the
list may be modified concurrently.

The following table lists some borrowed reference APIs and their
replacements that return *note strong references: 5e2.

Borrowed reference API                  Strong reference API
                                        
--------------------------------------------------------------------------------
                                        
*note PyList_GetItem(): 5ff.            *note PyList_GetItemRef(): 5fe.
                                        
                                        
*note PyList_GET_ITEM(): 4f37.          *note PyList_GetItemRef(): 5fe.
                                        
                                        
*note PyDict_GetItem(): 628.            *note PyDict_GetItemRef(): 5e0.
                                        
                                        
*note PyDict_GetItemWithError(): 5e1.   *note PyDict_GetItemRef(): 5e0.
                                        
                                        
*note PyDict_GetItemString(): 629.      *note PyDict_GetItemStringRef(): 421.
                                        
                                        
*note PyDict_SetDefault(): 5e4.         *note PyDict_SetDefaultRef(): 5e3.
                                        
                                        
*note PyDict_Next(): 1977.              none (see *note PyDict_Next: 584e.)
                                        
                                        
*note PyWeakref_GetObject(): 3dd.       *note PyWeakref_GetRef(): 3df.
                                        
                                        
*note PyWeakref_GET_OBJECT(): 3de.      *note PyWeakref_GetRef(): 3df.
                                        
                                        
*note PyImport_AddModule(): 5fc.        *note PyImport_AddModuleRef(): 5fb.
                                        
                                        
*note PyCell_GET(): 53e3.               *note PyCell_Get(): 53e2.
                                        

Not all APIs that return borrowed references are problematic.  For
example, *note PyTuple_GetItem(): 4ea0. is safe because tuples are
immutable.  Similarly, not all uses of the above APIs are problematic.
For example, *note PyDict_GetItem(): 628. is often used for parsing
keyword argument dictionaries in function calls; those keyword argument
dictionaries are effectively private (not accessible by other threads),
so using borrowed references in that context is safe.

Some of these functions were added in Python 3.13.  You can use the
pythoncapi-compat(1) package to provide implementations of these
functions for older Python versions.

   ---------- Footnotes ----------

   (1) https://github.com/python/pythoncapi-compat


File: python.info,  Node: Memory Allocation APIs,  Next: Thread State and GIL APIs,  Prev: Borrowed References,  Up: C API Extension Support for Free Threading

9.23.5 Memory Allocation APIs
-----------------------------

Python’s memory management C API provides functions in three different
*note allocation domains: 558a.: «raw», «mem», and «object».  For
thread-safety, the free-threaded build requires that only Python objects
are allocated using the object domain, and that all Python objects are
allocated using that domain.  This differs from the prior Python
versions, where this was only a best practice and not a hard
requirement.

     Nota: Search for uses of *note PyObject_Malloc(): e64. in your
     extension and check that the allocated memory is used for Python
     objects.  Use *note PyMem_Malloc(): e62. to allocate buffers
     instead of *note PyObject_Malloc(): e64.


File: python.info,  Node: Thread State and GIL APIs,  Next: Protecting Internal Extension State,  Prev: Memory Allocation APIs,  Up: C API Extension Support for Free Threading

9.23.6 Thread State and GIL APIs
--------------------------------

Python provides a set of functions and macros to manage thread state and
the GIL, such as:

   * *note PyGILState_Ensure(): 64a. and *note PyGILState_Release():
     64b.

   * *note PyEval_SaveThread(): 647. and *note PyEval_RestoreThread():
     648.

   * *note Py_BEGIN_ALLOW_THREADS: 4ea6. and *note Py_END_ALLOW_THREADS:
     c81.

These functions should still be used in the free-threaded build to
manage thread state even when the *note GIL: 164. is disabled.  For
example, if you create a thread outside of Python, you must call *note
PyGILState_Ensure(): 64a. before calling into the Python API to ensure
that the thread has a valid Python thread state.

You should continue to call *note PyEval_SaveThread(): 647. or *note
Py_BEGIN_ALLOW_THREADS: 4ea6. around blocking operations, such as I/O or
lock acquisitions, to allow other threads to run the *note cyclic
garbage collector: 17c0.


File: python.info,  Node: Protecting Internal Extension State,  Next: Critical Sections,  Prev: Thread State and GIL APIs,  Up: C API Extension Support for Free Threading

9.23.7 Protecting Internal Extension State
------------------------------------------

Your extension may have internal state that was previously protected by
the GIL. You may need to add locking to protect this state.  The
approach will depend on your extension, but some common patterns
include:

   * 'Caches': global caches are a common source of shared state.
     Consider using a lock to protect the cache or disabling it in the
     free-threaded build if the cache is not critical for performance.

   * 'Global State': global state may need to be protected by a lock or
     moved to thread local storage.  C11 and C++11 provide the
     ‘thread_local’ or ‘_Thread_local’ for thread-local storage(1).

   ---------- Footnotes ----------

   (1) https://en.cppreference.com/w/c/language/storage_duration


File: python.info,  Node: Critical Sections,  Next: Building Extensions for the Free-Threaded Build,  Prev: Protecting Internal Extension State,  Up: C API Extension Support for Free Threading

9.23.8 Critical Sections
------------------------

In the free-threaded build, CPython provides a mechanism called
«critical sections» to protect data that would otherwise be protected by
the GIL. While extension authors may not interact with the internal
critical section implementation directly, understanding their behavior
is crucial when using certain C API functions or managing shared state
in the free-threaded build.

* Menu:

* What Are Critical Sections?::
* Using Critical Sections::
* How Critical Sections Work::
* Deadlock Avoidance::
* Important Considerations::


File: python.info,  Node: What Are Critical Sections?,  Next: Using Critical Sections,  Up: Critical Sections

9.23.8.1 What Are Critical Sections?
....................................

Conceptually, critical sections act as a deadlock avoidance layer built
on top of simple mutexes.  Each thread maintains a stack of active
critical sections.  When a thread needs to acquire a lock associated
with a critical section (e.g., implicitly when calling a thread-safe C
API function like *note PyDict_SetItem(): 4ea2, or explicitly using
macros), it attempts to acquire the underlying mutex.


File: python.info,  Node: Using Critical Sections,  Next: How Critical Sections Work,  Prev: What Are Critical Sections?,  Up: Critical Sections

9.23.8.2 Using Critical Sections
................................

The primary APIs for using critical sections are:

   * *note Py_BEGIN_CRITICAL_SECTION: 5384. and *note
     Py_END_CRITICAL_SECTION: 5532. - For locking a single object

   * *note Py_BEGIN_CRITICAL_SECTION2: 5530. and *note
     Py_END_CRITICAL_SECTION2: 5534. - For locking two objects
     simultaneously

These macros must be used in matching pairs and must appear in the same
C scope, since they establish a new local scope.  These macros are
no-ops in non-free-threaded builds, so they can be safely added to code
that needs to support both build types.

A common use of a critical section would be to lock an object while
accessing an internal attribute of it.  For example, if an extension
type has an internal count field, you could use a critical section while
reading or writing that field:

     // read the count, returns new reference to internal count value
     PyObject *result;
     Py_BEGIN_CRITICAL_SECTION(obj);
     result = Py_NewRef(obj->count);
     Py_END_CRITICAL_SECTION();
     return result;

     // write the count, consumes reference from new_count
     Py_BEGIN_CRITICAL_SECTION(obj);
     obj->count = new_count;
     Py_END_CRITICAL_SECTION();


File: python.info,  Node: How Critical Sections Work,  Next: Deadlock Avoidance,  Prev: Using Critical Sections,  Up: Critical Sections

9.23.8.3 How Critical Sections Work
...................................

Unlike traditional locks, critical sections do not guarantee exclusive
access throughout their entire duration.  If a thread would block while
holding a critical section (e.g., by acquiring another lock or
performing I/O), the critical section is temporarily suspended—all locks
are released—and then resumed when the blocking operation completes.

This behavior is similar to what happens with the GIL when a thread
makes a blocking call.  The key differences are:

   * Critical sections operate on a per-object basis rather than
     globally

   * Critical sections follow a stack discipline within each thread (the
     «begin» and «end» macros enforce this since they must be paired and
     within the same scope)

   * Critical sections automatically release and reacquire locks around
     potential blocking operations


File: python.info,  Node: Deadlock Avoidance,  Next: Important Considerations,  Prev: How Critical Sections Work,  Up: Critical Sections

9.23.8.4 Deadlock Avoidance
...........................

Critical sections help avoid deadlocks in two ways:

  1. If a thread tries to acquire a lock that’s already held by another
     thread, it first suspends all of its active critical sections,
     temporarily releasing their locks

  2. When the blocking operation completes, only the top-most critical
     section is reacquired first

This means you cannot rely on nested critical sections to lock multiple
objects at once, as the inner critical section may suspend the outer
ones.  Instead, use *note Py_BEGIN_CRITICAL_SECTION2: 5530. to lock two
objects simultaneously.

Note that the locks described above are only *note PyMutex: 485. based
locks.  The critical section implementation does not know about or
affect other locking mechanisms that might be in use, like POSIX
mutexes.  Also note that while blocking on any *note PyMutex: 485.
causes the critical sections to be suspended, only the mutexes that are
part of the critical sections are released.  If *note PyMutex: 485. is
used without a critical section, it will not be released and therefore
does not get the same deadlock avoidance.


File: python.info,  Node: Important Considerations,  Prev: Deadlock Avoidance,  Up: Critical Sections

9.23.8.5 Important Considerations
.................................

   * Critical sections may temporarily release their locks, allowing
     other threads to modify the protected data.  Be careful about
     making assumptions about the state of the data after operations
     that might block.

   * Because locks can be temporarily released (suspended), entering a
     critical section does not guarantee exclusive access to the
     protected resource throughout the section’s duration.  If code
     within a critical section calls another function that blocks (e.g.,
     acquires another lock, performs blocking I/O), all locks held by
     the thread via critical sections will be released.  This is similar
     to how the GIL can be released during blocking calls.

   * Only the lock(s) associated with the most recently entered
     (top-most) critical section are guaranteed to be held at any given
     time.  Locks for outer, nested critical sections might have been
     suspended.

   * You can lock at most two objects simultaneously with these APIs.
     If you need to lock more objects, you’ll need to restructure your
     code.

   * While critical sections will not deadlock if you attempt to lock
     the same object twice, they are less efficient than purpose-built
     reentrant locks for this use case.

   * When using *note Py_BEGIN_CRITICAL_SECTION2: 5530, the order of the
     objects doesn’t affect correctness (the implementation handles
     deadlock avoidance), but it’s good practice to always lock objects
     in a consistent order.

   * Remember that the critical section macros are primarily for
     protecting access to 'Python objects' that might be involved in
     internal CPython operations susceptible to the deadlock scenarios
     described above.  For protecting purely internal extension state,
     standard mutexes or other synchronization primitives might be more
     appropriate.


File: python.info,  Node: Building Extensions for the Free-Threaded Build,  Prev: Critical Sections,  Up: C API Extension Support for Free Threading

9.23.9 Building Extensions for the Free-Threaded Build
------------------------------------------------------

C API extensions need to be built specifically for the free-threaded
build.  The wheels, shared libraries, and binaries are indicated by a
‘t’ suffix.

   * pypa/manylinux(1) supports the free-threaded build, with the ‘t’
     suffix, such as ‘python3.13t’.

   * pypa/cibuildwheel(2) supports the free-threaded build on Python
     3.13 and 3.14.  On Python 3.14, free-threaded wheels will be built
     by default.  On Python 3.13, you will need to set CIBW_ENABLE to
     cpython-freethreading(3).

* Menu:

* Limited C API and Stable ABI::
* Windows: Windows<84>.

   ---------- Footnotes ----------

   (1) https://github.com/pypa/manylinux

   (2) https://github.com/pypa/cibuildwheel

   (3) https://cibuildwheel.pypa.io/en/stable/options/#enable


File: python.info,  Node: Limited C API and Stable ABI,  Next: Windows<84>,  Up: Building Extensions for the Free-Threaded Build

9.23.9.1 Limited C API and Stable ABI
.....................................

The free-threaded build does not currently support the *note Limited C
API: 637. or the stable ABI. If you use setuptools(1) to build your
extension and currently set ‘py_limited_api=True’ you can use
‘py_limited_api=not sysconfig.get_config_var("Py_GIL_DISABLED")’ to opt
out of the limited API when building with the free-threaded build.

     Nota: You will need to build separate wheels specifically for the
     free-threaded build.  If you currently use the stable ABI, you can
     continue to build a single wheel for multiple non-free-threaded
     Python versions.

   ---------- Footnotes ----------

   (1) https://setuptools.pypa.io/en/latest/setuptools.html


File: python.info,  Node: Windows<84>,  Prev: Limited C API and Stable ABI,  Up: Building Extensions for the Free-Threaded Build

9.23.9.2 Windows
................

Due to a limitation of the official Windows installer, you will need to
manually define ‘Py_GIL_DISABLED=1’ when building extensions from
source.

Vedi anche
..........

Porting Extension Modules to Support Free-Threading(1): A
community-maintained porting guide for extension authors.

   ---------- Footnotes ----------

   (1) https://py-free-threading.github.io/porting/


File: python.info,  Node: Remote debugging attachment protocol,  Next: Permission requirements,  Prev: C API Extension Support for Free Threading,  Up: Python HOWTOs

9.24 Remote debugging attachment protocol
=========================================

This protocol enables external tools to attach to a running CPython
process and execute Python code remotely.

Most platforms require elevated privileges to attach to another Python
process.

* Menu:

* Disabling remote debugging::


File: python.info,  Node: Disabling remote debugging,  Up: Remote debugging attachment protocol

9.24.1 Disabling remote debugging
---------------------------------

To disable remote debugging support, use any of the following:

   * Set the *note PYTHON_DISABLE_REMOTE_DEBUG: 16e. environment
     variable to ‘1’ before starting the interpreter.

   * Use the *note -X disable_remote_debug: 16f. command-line option.

   * Compile Python with the *note -without-remote-debug: 170. build
     flag.


File: python.info,  Node: Permission requirements,  Next: Locating the PyRuntime structure,  Prev: Remote debugging attachment protocol,  Up: Python HOWTOs

9.25 Permission requirements
============================

Attaching to a running Python process for remote debugging requires
elevated privileges on most platforms.  The specific requirements and
troubleshooting steps depend on your operating system:

Linux
.....

The tracer process must have the ‘CAP_SYS_PTRACE’ capability or
equivalent privileges.  You can only trace processes you own and can
signal.  Tracing may fail if the process is already being traced, or if
it is running with set-user-ID or set-group-ID. Security modules like
Yama may further restrict tracing.

To temporarily relax ptrace restrictions (until reboot), run:

     ‘echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope’

     Nota: Disabling ‘ptrace_scope’ reduces system hardening and should
     only be done in trusted environments.

If running inside a container, use ‘--cap-add=SYS_PTRACE’ or
‘--privileged’, and run as root if needed.

Try re-running the command with elevated privileges:

     ‘sudo -E !!’

macOS
.....

To attach to another process, you typically need to run your debugging
tool with elevated privileges.  This can be done by using ‘sudo’ or
running as root.

Even when attaching to processes you own, macOS may block debugging
unless the debugger is run with root privileges due to system security
restrictions.

Windows
.......

To attach to another process, you usually need to run your debugging
tool with administrative privileges.  Start the command prompt or
terminal as Administrator.

Some processes may still be inaccessible even with Administrator rights,
unless you have the ‘SeDebugPrivilege’ privilege enabled.

To resolve file or folder access issues, adjust the security
permissions:

       1. Right-click the file or folder and select 'Properties'.

       2. Go to the 'Security' tab to view users and groups with access.

       3. Click 'Edit' to modify permissions.

       4. Select your user account.

       5. In 'Permissions', check 'Read' or 'Full control' as needed.

       6. Click 'Apply', then 'OK' to confirm.

     Nota: Ensure you’ve satisfied all *note Permission requirements:
     5862. before proceeding.

This section describes the low-level protocol that enables external
tools to inject and execute a Python script within a running CPython
process.

This mechanism forms the basis of the *note sys.remote_exec(): 16d.
function, which instructs a remote Python process to execute a ‘.py’
file.  However, this section does not document the usage of that
function.  Instead, it provides a detailed explanation of the underlying
protocol, which takes as input the ‘pid’ of a target Python process and
the path to a Python source file to be executed.  This information
supports independent reimplementation of the protocol, regardless of
programming language.

     Avvertimento: The execution of the injected script depends on the
     interpreter reaching a safe evaluation point.  As a result,
     execution may be delayed depending on the runtime state of the
     target process.

Once injected, the script is executed by the interpreter within the
target process the next time a safe evaluation point is reached.  This
approach enables remote execution capabilities without modifying the
behavior or structure of the running Python application.

Subsequent sections provide a step-by-step description of the protocol,
including techniques for locating interpreter structures in memory,
safely accessing internal fields, and triggering code execution.
Platform-specific variations are noted where applicable, and example
implementations are included to clarify each operation.


File: python.info,  Node: Locating the PyRuntime structure,  Next: Reading _Py_DebugOffsets,  Prev: Permission requirements,  Up: Python HOWTOs

9.26 Locating the PyRuntime structure
=====================================

CPython places the ‘PyRuntime’ structure in a dedicated binary section
to help external tools find it at runtime.  The name and format of this
section vary by platform.  For example, ‘.PyRuntime’ is used on ELF
systems, and ‘__DATA,__PyRuntime’ is used on macOS. Tools can find the
offset of this structure by examining the binary on disk.

The ‘PyRuntime’ structure contains CPython’s global interpreter state
and provides access to other internal data, including the list of
interpreters, thread states, and debugger support fields.

To work with a remote Python process, a debugger must first find the
memory address of the ‘PyRuntime’ structure in the target process.  This
address can’t be hardcoded or calculated from a symbol name, because it
depends on where the operating system loaded the binary.

The method for finding ‘PyRuntime’ depends on the platform, but the
steps are the same in general:

  1. Find the base address where the Python binary or shared library was
     loaded in the target process.

  2. Use the on-disk binary to locate the offset of the ‘.PyRuntime’
     section.

  3. Add the section offset to the base address to compute the address
     in memory.

The sections below explain how to do this on each supported platform and
include example code.

Linux (ELF)
...........

To find the ‘PyRuntime’ structure on Linux:

  1. Read the process’s memory map (for example, ‘/proc/<pid>/maps’) to
     find the address where the Python executable or ‘libpython’ was
     loaded.

  2. Parse the ELF section headers in the binary to get the offset of
     the ‘.PyRuntime’ section.

  3. Add that offset to the base address from step 1 to get the memory
     address of ‘PyRuntime’.

The following is an example implementation:

     def find_py_runtime_linux(pid: int) -> int:
         # Step 1: Try to find the Python executable in memory
         binary_path, base_address = find_mapped_binary(
             pid, name_contains="python"
         )

         # Step 2: Fallback to shared library if executable is not found
         if binary_path is None:
             binary_path, base_address = find_mapped_binary(
                 pid, name_contains="libpython"
             )

         # Step 3: Parse ELF headers to get .PyRuntime section offset
         section_offset = parse_elf_section_offset(
             binary_path, ".PyRuntime"
         )

         # Step 4: Compute PyRuntime address in memory
         return base_address + section_offset

On Linux systems, there are two main approaches to read memory from
another process.  The first is through the ‘/proc’ filesystem,
specifically by reading from ‘/proc/[pid]/mem’ which provides direct
access to the process’s memory.  This requires appropriate permissions -
either being the same user as the target process or having root access.
The second approach is using the ‘process_vm_readv()’ system call which
provides a more efficient way to copy memory between processes.  While
ptrace’s ‘PTRACE_PEEKTEXT’ operation can also be used to read memory, it
is significantly slower as it only reads one word at a time and requires
multiple context switches between the tracer and tracee processes.

For parsing ELF sections, the process involves reading and interpreting
the ELF file format structures from the binary file on disk.  The ELF
header contains a pointer to the section header table.  Each section
header contains metadata about a section including its name (stored in a
separate string table), offset, and size.  To find a specific section
like .PyRuntime, you need to walk through these headers and match the
section name.  The section header then provides the offset where that
section exists in the file, which can be used to calculate its runtime
address when the binary is loaded into memory.

You can read more about the ELF file format in the ELF specification(1).

macOS (Mach-O)
..............

To find the ‘PyRuntime’ structure on macOS:

  1. Call ‘task_for_pid()’ to get the ‘mach_port_t’ task port for the
     target process.  This handle is needed to read memory using APIs
     like ‘mach_vm_read_overwrite’ and ‘mach_vm_region’.

  2. Scan the memory regions to find the one containing the Python
     executable or ‘libpython’.

  3. Load the binary file from disk and parse the Mach-O headers to find
     the section named ‘PyRuntime’ in the ‘__DATA’ segment.  On macOS,
     symbol names are automatically prefixed with an underscore, so the
     ‘PyRuntime’ symbol appears as ‘_PyRuntime’ in the symbol table, but
     the section name is not affected.

The following is an example implementation:

     def find_py_runtime_macos(pid: int) -> int:
         # Step 1: Get access to the process's memory
         handle = get_memory_access_handle(pid)

         # Step 2: Try to find the Python executable in memory
         binary_path, base_address = find_mapped_binary(
             handle, name_contains="python"
         )

         # Step 3: Fallback to libpython if the executable is not found
         if binary_path is None:
             binary_path, base_address = find_mapped_binary(
                 handle, name_contains="libpython"
             )

         # Step 4: Parse Mach-O headers to get __DATA,__PyRuntime section offset
         section_offset = parse_macho_section_offset(
             binary_path, "__DATA", "__PyRuntime"
         )

         # Step 5: Compute the PyRuntime address in memory
         return base_address + section_offset

On macOS, accessing another process’s memory requires using Mach-O
specific APIs and file formats.  The first step is obtaining a
‘task_port’ handle via ‘task_for_pid()’, which provides access to the
target process’s memory space.  This handle enables memory operations
through APIs like ‘mach_vm_read_overwrite()’.

The process memory can be examined using ‘mach_vm_region()’ to scan
through the virtual memory space, while ‘proc_regionfilename()’ helps
identify which binary files are loaded at each memory region.  When the
Python binary or library is found, its Mach-O headers need to be parsed
to locate the ‘PyRuntime’ structure.

The Mach-O format organizes code and data into segments and sections.
The ‘PyRuntime’ structure lives in a section named ‘__PyRuntime’ within
the ‘__DATA’ segment.  The actual runtime address calculation involves
finding the ‘__TEXT’ segment which serves as the binary’s base address,
then locating the ‘__DATA’ segment containing our target section.  The
final address is computed by combining the base address with the
appropriate section offsets from the Mach-O headers.

Note that accessing another process’s memory on macOS typically requires
elevated privileges - either root access or special security
entitlements granted to the debugging process.

Windows (PE)
............

To find the ‘PyRuntime’ structure on Windows:

  1. Use the ToolHelp API to enumerate all modules loaded in the target
     process.  This is done using functions such as
     CreateToolhelp32Snapshot(2), Module32First(3), and Module32Next(4).

  2. Identify the module corresponding to ‘python.exe’ or
     ‘python`XY'.dll’, where ‘X’ and ‘Y’ are the major and minor version
     numbers of the Python version, and record its base address.

  3. Locate the ‘PyRuntim’ section.  Due to the PE format’s 8-character
     limit on section names (defined as ‘IMAGE_SIZEOF_SHORT_NAME’), the
     original name ‘PyRuntime’ is truncated.  This section contains the
     ‘PyRuntime’ structure.

  4. Retrieve the section’s relative virtual address (RVA) and add it to
     the base address of the module.

The following is an example implementation:

     def find_py_runtime_windows(pid: int) -> int:
         # Step 1: Try to find the Python executable in memory
         binary_path, base_address = find_loaded_module(
             pid, name_contains="python"
         )

         # Step 2: Fallback to shared pythonXY.dll if the executable is not
         # found
         if binary_path is None:
             binary_path, base_address = find_loaded_module(
                 pid, name_contains="python3"
             )

         # Step 3: Parse PE section headers to get the RVA of the PyRuntime
         # section. The section name appears as "PyRuntim" due to the
         # 8-character limit defined by the PE format (IMAGE_SIZEOF_SHORT_NAME).
         section_rva = parse_pe_section_offset(binary_path, "PyRuntim")

         # Step 4: Compute PyRuntime address in memory
         return base_address + section_rva

On Windows, accessing another process’s memory requires using the
Windows API functions like ‘CreateToolhelp32Snapshot()’ and
‘Module32First()/Module32Next()’ to enumerate loaded modules.  The
‘OpenProcess()’ function provides a handle to access the target
process’s memory space, enabling memory operations through
‘ReadProcessMemory()’.

The process memory can be examined by enumerating loaded modules to find
the Python binary or DLL. When found, its PE headers need to be parsed
to locate the ‘PyRuntime’ structure.

The PE format organizes code and data into sections.  The ‘PyRuntime’
structure lives in a section named «PyRuntim» (truncated from
«PyRuntime» due to PE’s 8-character name limit).  The actual runtime
address calculation involves finding the module’s base address from the
module entry, then locating our target section in the PE headers.  The
final address is computed by combining the base address with the
section’s virtual address from the PE section headers.

Note that accessing another process’s memory on Windows typically
requires appropriate privileges - either administrative access or the
‘SeDebugPrivilege’ privilege granted to the debugging process.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Executable_and_Linkable_Format

   (2) 
https://learn.microsoft.com/en-us/windows/win32/api/tlhelp32/nf-tlhelp32-createtoolhelp32snapshot

   (3) 
https://learn.microsoft.com/en-us/windows/win32/api/tlhelp32/nf-tlhelp32-module32first

   (4) 
https://learn.microsoft.com/en-us/windows/win32/api/tlhelp32/nf-tlhelp32-module32next


File: python.info,  Node: Reading _Py_DebugOffsets,  Next: Locating the interpreter and thread state,  Prev: Locating the PyRuntime structure,  Up: Python HOWTOs

9.27 Reading _Py_DebugOffsets
=============================

Once the address of the ‘PyRuntime’ structure has been determined, the
next step is to read the ‘_Py_DebugOffsets’ structure located at the
beginning of the ‘PyRuntime’ block.

This structure provides version-specific field offsets that are needed
to safely read interpreter and thread state memory.  These offsets vary
between CPython versions and must be checked before use to ensure they
are compatible.

To read and check the debug offsets, follow these steps:

  1. Read memory from the target process starting at the ‘PyRuntime’
     address, covering the same number of bytes as the
     ‘_Py_DebugOffsets’ structure.  This structure is located at the
     very start of the ‘PyRuntime’ memory block.  Its layout is defined
     in CPython’s internal headers and stays the same within a given
     minor version, but may change in major versions.

  2. Check that the structure contains valid data:

        - The ‘cookie’ field must match the expected debug marker.

        - The ‘version’ field must match the version of the Python
          interpreter used by the debugger.

        - If either the debugger or the target process is using a
          pre-release version (for example, an alpha, beta, or release
          candidate), the versions must match exactly.

        - The ‘free_threaded’ field must have the same value in both the
          debugger and the target process.

  3. If the structure is valid, the offsets it contains can be used to
     locate fields in memory.  If any check fails, the debugger should
     stop the operation to avoid reading memory in the wrong format.

The following is an example implementation that reads and checks
‘_Py_DebugOffsets’:

     def read_debug_offsets(pid: int, py_runtime_addr: int) -> DebugOffsets:
         # Step 1: Read memory from the target process at the PyRuntime address
         data = read_process_memory(
             pid, address=py_runtime_addr, size=DEBUG_OFFSETS_SIZE
         )

         # Step 2: Deserialize the raw bytes into a _Py_DebugOffsets structure
         debug_offsets = parse_debug_offsets(data)

         # Step 3: Validate the contents of the structure
         if debug_offsets.cookie != EXPECTED_COOKIE:
             raise RuntimeError("Invalid or missing debug cookie")
         if debug_offsets.version != LOCAL_PYTHON_VERSION:
             raise RuntimeError(
                 "Mismatch between caller and target Python versions"
             )
         if debug_offsets.free_threaded != LOCAL_FREE_THREADED:
             raise RuntimeError("Mismatch in free-threaded configuration")

         return debug_offsets

     Avvertimento: 'Process suspension recommended'

     To avoid race conditions and ensure memory consistency, it is
     strongly recommended that the target process be suspended before
     performing any operations that read or write internal interpreter
     state.  The Python runtime may concurrently mutate interpreter data
     structures—such as creating or destroying threads—during normal
     execution.  This can result in invalid memory reads or writes.

     A debugger may suspend execution by attaching to the process with
     ‘ptrace’ or by sending a ‘SIGSTOP’ signal.  Execution should only
     be resumed after debugger-side memory operations are complete.

          Nota: Some tools, such as profilers or sampling-based
          debuggers, may operate on a running process without
          suspension.  In such cases, tools must be explicitly designed
          to handle partially updated or inconsistent memory.  For most
          debugger implementations, suspending the process remains the
          safest and most robust approach.


File: python.info,  Node: Locating the interpreter and thread state,  Next: Writing control information,  Prev: Reading _Py_DebugOffsets,  Up: Python HOWTOs

9.28 Locating the interpreter and thread state
==============================================

Before code can be injected and executed in a remote Python process, the
debugger must choose a thread in which to schedule execution.  This is
necessary because the control fields used to perform remote code
injection are located in the ‘_PyRemoteDebuggerSupport’ structure, which
is embedded in a ‘PyThreadState’ object.  These fields are modified by
the debugger to request execution of injected scripts.

The ‘PyThreadState’ structure represents a thread running inside a
Python interpreter.  It maintains the thread’s evaluation context and
contains the fields required for debugger coordination.  Locating a
valid ‘PyThreadState’ is therefore a key prerequisite for triggering
execution remotely.

A thread is typically selected based on its role or ID. In most cases,
the main thread is used, but some tools may target a specific thread by
its native thread ID. Once the target thread is chosen, the debugger
must locate both the interpreter and the associated thread state
structures in memory.

The relevant internal structures are defined as follows:

   - ‘PyInterpreterState’ represents an isolated Python interpreter
     instance.  Each interpreter maintains its own set of imported
     modules, built-in state, and thread state list.  Although most
     Python applications use a single interpreter, CPython supports
     multiple interpreters in the same process.

   - ‘PyThreadState’ represents a thread running within an interpreter.
     It contains execution state and the control fields used by the
     debugger.

To locate a thread:

  1. Use the offset ‘runtime_state.interpreters_head’ to obtain the
     address of the first interpreter in the ‘PyRuntime’ structure.
     This is the entry point to the linked list of active interpreters.

  2. Use the offset ‘interpreter_state.threads_main’ to access the main
     thread state associated with the selected interpreter.  This is
     typically the most reliable thread to target.

  3. Optionally, use the offset ‘interpreter_state.threads_head’ to
     iterate through the linked list of all thread states.  Each
     ‘PyThreadState’ structure contains a ‘native_thread_id’ field,
     which may be compared to a target thread ID to find a specific
     thread.

  4. Once a valid ‘PyThreadState’ has been found, its address can be
     used in later steps of the protocol, such as writing debugger
     control fields and scheduling execution.

The following is an example implementation that locates the main thread
state:

     def find_main_thread_state(
         pid: int, py_runtime_addr: int, debug_offsets: DebugOffsets,
     ) -> int:
         # Step 1: Read interpreters_head from PyRuntime
         interp_head_ptr = (
             py_runtime_addr + debug_offsets.runtime_state.interpreters_head
         )
         interp_addr = read_pointer(pid, interp_head_ptr)
         if interp_addr == 0:
             raise RuntimeError("No interpreter found in the target process")

         # Step 2: Read the threads_main pointer from the interpreter
         threads_main_ptr = (
             interp_addr + debug_offsets.interpreter_state.threads_main
         )
         thread_state_addr = read_pointer(pid, threads_main_ptr)
         if thread_state_addr == 0:
             raise RuntimeError("Main thread state is not available")

         return thread_state_addr

The following example demonstrates how to locate a thread by its native
thread ID:

     def find_thread_by_id(
         pid: int,
         interp_addr: int,
         debug_offsets: DebugOffsets,
         target_tid: int,
     ) -> int:
         # Start at threads_head and walk the linked list
         thread_ptr = read_pointer(
             pid,
             interp_addr + debug_offsets.interpreter_state.threads_head
         )

         while thread_ptr:
             native_tid_ptr = (
                 thread_ptr + debug_offsets.thread_state.native_thread_id
             )
             native_tid = read_int(pid, native_tid_ptr)
             if native_tid == target_tid:
                 return thread_ptr
             thread_ptr = read_pointer(
                 pid,
                 thread_ptr + debug_offsets.thread_state.next
             )

         raise RuntimeError("Thread with the given ID was not found")

Once a valid thread state has been located, the debugger can proceed
with modifying its control fields and scheduling execution, as described
in the next section.


File: python.info,  Node: Writing control information,  Next: Summary,  Prev: Locating the interpreter and thread state,  Up: Python HOWTOs

9.29 Writing control information
================================

Once a valid ‘PyThreadState’ structure has been identified, the debugger
may modify control fields within it to schedule the execution of a
specified Python script.  These control fields are checked periodically
by the interpreter, and when set correctly, they trigger the execution
of remote code at a safe point in the evaluation loop.

Each ‘PyThreadState’ contains a ‘_PyRemoteDebuggerSupport’ structure
used for communication between the debugger and the interpreter.  The
locations of its fields are defined by the ‘_Py_DebugOffsets’ structure
and include the following:

   - ‘debugger_script_path’: A fixed-size buffer that holds the full
     path to a Python source file (‘.py’).  This file must be accessible
     and readable by the target process when execution is triggered.

   - ‘debugger_pending_call’: An integer flag.  Setting this to ‘1’
     tells the interpreter that a script is ready to be executed.

   - ‘eval_breaker’: A field checked by the interpreter during
     execution.  Setting bit 5 (‘_PY_EVAL_PLEASE_STOP_BIT’, value ‘1U <<
     5’) in this field causes the interpreter to pause and check for
     debugger activity.

To complete the injection, the debugger must perform the following
steps:

  1. Write the full script path into the ‘debugger_script_path’ buffer.

  2. Set ‘debugger_pending_call’ to ‘1’.

  3. Read the current value of ‘eval_breaker’, set bit 5
     (‘_PY_EVAL_PLEASE_STOP_BIT’), and write the updated value back.
     This signals the interpreter to check for debugger activity.

The following is an example implementation:

     def inject_script(
         pid: int,
         thread_state_addr: int,
         debug_offsets: DebugOffsets,
         script_path: str
     ) -> None:
         # Compute the base offset of _PyRemoteDebuggerSupport
         support_base = (
             thread_state_addr +
             debug_offsets.debugger_support.remote_debugger_support
         )

         # Step 1: Write the script path into debugger_script_path
         script_path_ptr = (
             support_base +
             debug_offsets.debugger_support.debugger_script_path
         )
         write_string(pid, script_path_ptr, script_path)

         # Step 2: Set debugger_pending_call to 1
         pending_ptr = (
             support_base +
             debug_offsets.debugger_support.debugger_pending_call
         )
         write_int(pid, pending_ptr, 1)

         # Step 3: Set _PY_EVAL_PLEASE_STOP_BIT (bit 5, value 1 << 5) in
         # eval_breaker
         eval_breaker_ptr = (
             thread_state_addr +
             debug_offsets.debugger_support.eval_breaker
         )
         breaker = read_int(pid, eval_breaker_ptr)
         breaker |= (1 << 5)
         write_int(pid, eval_breaker_ptr, breaker)

Once these fields are set, the debugger may resume the process (if it
was suspended).  The interpreter will process the request at the next
safe evaluation point, load the script from disk, and execute it.

It is the responsibility of the debugger to ensure that the script file
remains present and accessible to the target process during execution.

     Nota: Script execution is asynchronous.  The script file cannot be
     deleted immediately after injection.  The debugger should wait
     until the injected script has produced an observable effect before
     removing the file.  This effect depends on what the script is
     designed to do.  For example, a debugger might wait until the
     remote process connects back to a socket before removing the
     script.  Once such an effect is observed, it is safe to assume the
     file is no longer needed.


File: python.info,  Node: Summary,  Prev: Writing control information,  Up: Python HOWTOs

9.30 Summary
============

To inject and execute a Python script in a remote process:

  1. Locate the ‘PyRuntime’ structure in the target process’s memory.

  2. Read and validate the ‘_Py_DebugOffsets’ structure at the beginning
     of ‘PyRuntime’.

  3. Use the offsets to locate a valid ‘PyThreadState’.

  4. Write the path to a Python script into ‘debugger_script_path’.

  5. Set the ‘debugger_pending_call’ flag to ‘1’.

  6. Set ‘_PY_EVAL_PLEASE_STOP_BIT’ in the ‘eval_breaker’ field.

  7. Resume the process (if suspended).  The script will execute at the
     next safe evaluation point.

General:

   * *note A Conceptual Overview of asyncio: 379d.

   * *note Annotations Best Practices: 9db.

   * *note Argparse Tutorial: 3352.

   * *note Descriptor Guide: 16f4.

   * *note Enum HOWTO: 56c9.

   * *note Functional Programming HOWTO: 56fb.

   * *note An introduction to the ipaddress module: 41af.

   * *note Logging HOWTO: 571a.

   * *note Logging Cookbook: 13ff.

   * *note Regular Expression HOWTO: 2745.

   * *note Sorting Techniques: 25bb.

   * *note Unicode HOWTO: 14ac.

   * *note HOWTO Fetch Internet Resources Using The urllib Package:
     3f71.

Advanced development:

   * *note Curses Programming with Python: 3445.

   * *note Python support for free threading: 25f5.

   * *note C API Extension Support for Free Threading: 5836.

   * *note Isolating Extension Modules: 166.

   * *note The Python 2.3 Method Resolution Order: 16b1.

   * *note Socket Programming HOWTO: 3987.

   * *note timer file descriptor HOWTO: 5827.

   * *note Porting Extension Modules to Python 3: 14e8.

Debugging and profiling:

   * *note Debugging C API extensions and CPython Internals with GDB:
     56ba.

   * *note Instrumenting CPython with DTrace and SystemTap: e68.

   * *note Python support for the Linux perf profiler: 4af.

   * *note Remote debugging attachment protocol: 490f.


File: python.info,  Node: Python Frequently Asked Questions,  Next: Deprecations,  Prev: Python HOWTOs,  Up: Top

10 Python Frequently Asked Questions
************************************

* Menu:

* General Python FAQ::
* Programming FAQ::
* Design and History FAQ::
* Library and Extension FAQ::
* Extending/Embedding FAQ::
* Python on Windows FAQ::
* Graphic User Interface FAQ::
* «Why is Python Installed on my Computer?» FAQ::


File: python.info,  Node: General Python FAQ,  Next: Programming FAQ,  Up: Python Frequently Asked Questions

10.1 General Python FAQ
=======================

* Menu:

* General Information::
* Python in the real world::


File: python.info,  Node: General Information,  Next: Python in the real world,  Up: General Python FAQ

10.1.1 General Information
--------------------------

* Menu:

* What is Python?::
* What is the Python Software Foundation?::
* Are there copyright restrictions on the use of Python?::
* Why was Python created in the first place?::
* What is Python good for?::
* How does the Python version numbering scheme work?::
* How do I obtain a copy of the Python source?::
* How do I get documentation on Python?::
* I’ve never programmed before. Is there a Python tutorial?: I’ve never programmed before Is there a Python tutorial?.
* Is there a newsgroup or mailing list devoted to Python?::
* How do I get a beta test version of Python?::
* How do I submit bug reports and patches for Python?::
* Are there any published articles about Python that I can reference?::
* Are there any books on Python?::
* Where in the world is www.python.org located?: Where in the world is www python org located?.
* Why is it called Python?::
* Do I have to like «Monty Python’s Flying Circus»?::


File: python.info,  Node: What is Python?,  Next: What is the Python Software Foundation?,  Up: General Information

10.1.1.1 What is Python?
........................

Python is an interpreted, interactive, object-oriented programming
language.  It incorporates modules, exceptions, dynamic typing, very
high level dynamic data types, and classes.  It supports multiple
programming paradigms beyond object-oriented programming, such as
procedural and functional programming.  Python combines remarkable power
with very clear syntax.  It has interfaces to many system calls and
libraries, as well as to various window systems, and is extensible in C
or C++.  It is also usable as an extension language for applications
that need a programmable interface.  Finally, Python is portable: it
runs on many Unix variants including Linux and macOS, and on Windows.

To find out more, start with *note Tutorial su Python: 1fa4.  The
Beginner's Guide to Python(1) links to other introductory tutorials and
resources for learning Python.

   ---------- Footnotes ----------

   (1) https://wiki.python.org/moin/BeginnersGuide


File: python.info,  Node: What is the Python Software Foundation?,  Next: Are there copyright restrictions on the use of Python?,  Prev: What is Python?,  Up: General Information

10.1.1.2 What is the Python Software Foundation?
................................................

The Python Software Foundation is an independent non-profit organization
that holds the copyright on Python versions 2.1 and newer.  The PSF’s
mission is to advance open source technology related to the Python
programming language and to publicize the use of Python.  The PSF’s home
page is at ‘https://www.python.org/psf/’.

Donations to the PSF are tax-exempt in the US. If you use Python and
find it helpful, please contribute via the PSF donation page(1).

   ---------- Footnotes ----------

   (1) https://www.python.org/psf/donations/


File: python.info,  Node: Are there copyright restrictions on the use of Python?,  Next: Why was Python created in the first place?,  Prev: What is the Python Software Foundation?,  Up: General Information

10.1.1.3 Are there copyright restrictions on the use of Python?
...............................................................

You can do anything you want with the source, as long as you leave the
copyrights in and display those copyrights in any documentation about
Python that you produce.  If you honor the copyright rules, it’s OK to
use Python for commercial use, to sell copies of Python in source or
binary form (modified or unmodified), or to sell products that
incorporate Python in some form.  We would still like to know about all
commercial use of Python, of course.

See the license page(1) to find further explanations and the full text
of the PSF License.

The Python logo is trademarked, and in certain cases permission is
required to use it.  Consult the Trademark Usage Policy(2) for more
information.

   ---------- Footnotes ----------

   (1) https://docs.python.org/3/license.html

   (2) https://www.python.org/psf/trademarks/


File: python.info,  Node: Why was Python created in the first place?,  Next: What is Python good for?,  Prev: Are there copyright restrictions on the use of Python?,  Up: General Information

10.1.1.4 Why was Python created in the first place?
...................................................

Here’s a 'very' brief summary of what started it all, written by Guido
van Rossum:

     I had extensive experience with implementing an interpreted
     language in the ABC group at CWI, and from working with this group
     I had learned a lot about language design.  This is the origin of
     many Python features, including the use of indentation for
     statement grouping and the inclusion of very-high-level data types
     (although the details are all different in Python).

     I had a number of gripes about the ABC language, but also liked
     many of its features.  It was impossible to extend the ABC language
     (or its implementation) to remedy my complaints – in fact its lack
     of extensibility was one of its biggest problems.  I had some
     experience with using Modula-2+ and talked with the designers of
     Modula-3 and read the Modula-3 report.  Modula-3 is the origin of
     the syntax and semantics used for exceptions, and some other Python
     features.

     I was working in the Amoeba distributed operating system group at
     CWI. We needed a better way to do system administration than by
     writing either C programs or Bourne shell scripts, since Amoeba had
     its own system call interface which wasn’t easily accessible from
     the Bourne shell.  My experience with error handling in Amoeba made
     me acutely aware of the importance of exceptions as a programming
     language feature.

     It occurred to me that a scripting language with a syntax like ABC
     but with access to the Amoeba system calls would fill the need.  I
     realized that it would be foolish to write an Amoeba-specific
     language, so I decided that I needed a language that was generally
     extensible.

     During the 1989 Christmas holidays, I had a lot of time on my hand,
     so I decided to give it a try.  During the next year, while still
     mostly working on it in my own time, Python was used in the Amoeba
     project with increasing success, and the feedback from colleagues
     made me add many early improvements.

     In February 1991, after just over a year of development, I decided
     to post to USENET. The rest is in the ‘Misc/HISTORY’ file.


File: python.info,  Node: What is Python good for?,  Next: How does the Python version numbering scheme work?,  Prev: Why was Python created in the first place?,  Up: General Information

10.1.1.5 What is Python good for?
.................................

Python is a high-level general-purpose programming language that can be
applied to many different classes of problems.

The language comes with a large standard library that covers areas such
as string processing (regular expressions, Unicode, calculating
differences between files), internet protocols (HTTP, FTP, SMTP,
XML-RPC, POP, IMAP), software engineering (unit testing, logging,
profiling, parsing Python code), and operating system interfaces (system
calls, filesystems, TCP/IP sockets).  Look at the table of contents for
*note The Python Standard Library: 149. to get an idea of what’s
available.  A wide variety of third-party extensions are also available.
Consult the Python Package Index(1) to find packages of interest to you.

   ---------- Footnotes ----------

   (1) https://pypi.org


File: python.info,  Node: How does the Python version numbering scheme work?,  Next: How do I obtain a copy of the Python source?,  Prev: What is Python good for?,  Up: General Information

10.1.1.6 How does the Python version numbering scheme work?
...........................................................

Python versions are numbered «A.B.C» or «A.B»:

   * 'A' is the major version number – it is only incremented for really
     major changes in the language.

   * 'B' is the minor version number – it is incremented for less
     earth-shattering changes.

   * 'C' is the micro version number – it is incremented for each bugfix
     release.

Not all releases are bugfix releases.  In the run-up to a new feature
release, a series of development releases are made, denoted as alpha,
beta, or release candidate.  Alphas are early releases in which
interfaces aren’t yet finalized; it’s not unexpected to see an interface
change between two alpha releases.  Betas are more stable, preserving
existing interfaces but possibly adding new modules, and release
candidates are frozen, making no changes except as needed to fix
critical bugs.

Alpha, beta and release candidate versions have an additional suffix:

   * The suffix for an alpha version is «aN» for some small number 'N'.

   * The suffix for a beta version is «bN» for some small number 'N'.

   * The suffix for a release candidate version is «rcN» for some small
     number 'N'.

In other words, all versions labeled '2.0aN' precede the versions
labeled '2.0bN', which precede versions labeled '2.0rcN', and 'those'
precede 2.0.

You may also find version numbers with a «+» suffix, e.g.  «2.2+».
These are unreleased versions, built directly from the CPython
development repository.  In practice, after a final minor release is
made, the version is incremented to the next minor version, which
becomes the «a0» version, e.g.  «2.4a0».

See the Developer's Guide(1) for more information about the development
cycle, and PEP 387(2) to learn more about Python’s backward
compatibility policy.  See also the documentation for *note sys.version:
49d, *note sys.hexversion: 4909, and *note sys.version_info: 8b0.

   ---------- Footnotes ----------

   (1) https://devguide.python.org/developer-workflow/development-cycle/

   (2) https://peps.python.org/pep-0387/


File: python.info,  Node: How do I obtain a copy of the Python source?,  Next: How do I get documentation on Python?,  Prev: How does the Python version numbering scheme work?,  Up: General Information

10.1.1.7 How do I obtain a copy of the Python source?
.....................................................

The latest Python source distribution is always available from
python.org, at ‘https://www.python.org/downloads/’.  The latest
development sources can be obtained at
‘https://github.com/python/cpython/’.

The source distribution is a gzipped tar file containing the complete C
source, Sphinx-formatted documentation, Python library modules, example
programs, and several useful pieces of freely distributable software.
The source will compile and run out of the box on most UNIX platforms.

Consult the Getting Started section of the Python Developer's Guide(1)
for more information on getting the source code and compiling it.

   ---------- Footnotes ----------

   (1) https://devguide.python.org/setup/


File: python.info,  Node: How do I get documentation on Python?,  Next: I’ve never programmed before Is there a Python tutorial?,  Prev: How do I obtain a copy of the Python source?,  Up: General Information

10.1.1.8 How do I get documentation on Python?
..............................................

The standard documentation for the current stable version of Python is
available at ‘https://docs.python.org/3/’.  EPUB, plain text, and
downloadable HTML versions are also available at
‘https://docs.python.org/3/download.html’.

The documentation is written in reStructuredText and processed by the
Sphinx documentation tool(1).  The reStructuredText source for the
documentation is part of the Python source distribution.

   ---------- Footnotes ----------

   (1) https://www.sphinx-doc.org/


File: python.info,  Node: I’ve never programmed before Is there a Python tutorial?,  Next: Is there a newsgroup or mailing list devoted to Python?,  Prev: How do I get documentation on Python?,  Up: General Information

10.1.1.9 I’ve never programmed before. Is there a Python tutorial?
..................................................................

There are numerous tutorials and books available.  The standard
documentation includes *note Tutorial su Python: 1fa4.

Consult the Beginner's Guide(1) to find information for beginning Python
programmers, including lists of tutorials.

   ---------- Footnotes ----------

   (1) https://wiki.python.org/moin/BeginnersGuide


File: python.info,  Node: Is there a newsgroup or mailing list devoted to Python?,  Next: How do I get a beta test version of Python?,  Prev: I’ve never programmed before Is there a Python tutorial?,  Up: General Information

10.1.1.10 Is there a newsgroup or mailing list devoted to Python?
.................................................................

There is a newsgroup, ‘comp.lang.python’, and a mailing list,
python-list(1).  The newsgroup and mailing list are gatewayed into each
other – if you can read news it’s unnecessary to subscribe to the
mailing list.  ‘comp.lang.python’ is high-traffic, receiving hundreds of
postings every day, and Usenet readers are often more able to cope with
this volume.

Announcements of new software releases and events can be found in
comp.lang.python.announce, a low-traffic moderated list that receives
about five postings per day.  It’s available as the python-announce
mailing list(2).

More info about other mailing lists and newsgroups can be found at
‘https://www.python.org/community/lists/’.

   ---------- Footnotes ----------

   (1) https://mail.python.org/mailman/listinfo/python-list

   (2) 
https://mail.python.org/mailman3/lists/python-announce-list.python.org/


File: python.info,  Node: How do I get a beta test version of Python?,  Next: How do I submit bug reports and patches for Python?,  Prev: Is there a newsgroup or mailing list devoted to Python?,  Up: General Information

10.1.1.11 How do I get a beta test version of Python?
.....................................................

Alpha and beta releases are available from
‘https://www.python.org/downloads/’.  All releases are announced on the
comp.lang.python and comp.lang.python.announce newsgroups and on the
Python home page at ‘https://www.python.org/’; an RSS feed of news is
available.

You can also access the development version of Python through Git.  See
The Python Developer's Guide(1) for details.

   ---------- Footnotes ----------

   (1) https://devguide.python.org/


File: python.info,  Node: How do I submit bug reports and patches for Python?,  Next: Are there any published articles about Python that I can reference?,  Prev: How do I get a beta test version of Python?,  Up: General Information

10.1.1.12 How do I submit bug reports and patches for Python?
.............................................................

To report a bug or submit a patch, use the issue tracker at
‘https://github.com/python/cpython/issues’.

For more information on how Python is developed, consult the Python
Developer's Guide(1).

   ---------- Footnotes ----------

   (1) https://devguide.python.org/


File: python.info,  Node: Are there any published articles about Python that I can reference?,  Next: Are there any books on Python?,  Prev: How do I submit bug reports and patches for Python?,  Up: General Information

10.1.1.13 Are there any published articles about Python that I can reference?
.............................................................................

It’s probably best to cite your favorite book about Python.

The very first article(1) about Python was written in 1991 and is now
quite outdated.

     Guido van Rossum and Jelke de Boer, «Interactively Testing Remote
     Servers Using the Python Programming Language», CWI Quarterly,
     Volume 4, Issue 4 (December 1991), Amsterdam, pp 283–303.

   ---------- Footnotes ----------

   (1) https://ir.cwi.nl/pub/18204


File: python.info,  Node: Are there any books on Python?,  Next: Where in the world is www python org located?,  Prev: Are there any published articles about Python that I can reference?,  Up: General Information

10.1.1.14 Are there any books on Python?
........................................

Yes, there are many, and more are being published.  See the python.org
wiki at ‘https://wiki.python.org/moin/PythonBooks’ for a list.

You can also search online bookstores for «Python» and filter out the
Monty Python references; or perhaps search for «Python» and «language».


File: python.info,  Node: Where in the world is www python org located?,  Next: Why is it called Python?,  Prev: Are there any books on Python?,  Up: General Information

10.1.1.15 Where in the world is www.python.org located?
.......................................................

The Python project’s infrastructure is located all over the world and is
managed by the Python Infrastructure Team.  Details here(1).

   ---------- Footnotes ----------

   (1) https://infra.psf.io


File: python.info,  Node: Why is it called Python?,  Next: Do I have to like «Monty Python’s Flying Circus»?,  Prev: Where in the world is www python org located?,  Up: General Information

10.1.1.16 Why is it called Python?
..................................

When he began implementing Python, Guido van Rossum was also reading the
published scripts from "Monty Python's Flying Circus"(1), a BBC comedy
series from the 1970s.  Van Rossum thought he needed a name that was
short, unique, and slightly mysterious, so he decided to call the
language Python.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/Monty_Python


File: python.info,  Node: Do I have to like «Monty Python’s Flying Circus»?,  Prev: Why is it called Python?,  Up: General Information

10.1.1.17 Do I have to like «Monty Python’s Flying Circus»?
...........................................................

No, but it helps.  :)


File: python.info,  Node: Python in the real world,  Prev: General Information,  Up: General Python FAQ

10.1.2 Python in the real world
-------------------------------

* Menu:

* How stable is Python?::
* How many people are using Python?::
* Have any significant projects been done in Python?::
* What new developments are expected for Python in the future?::
* Is it reasonable to propose incompatible changes to Python?::
* Is Python a good language for beginning programmers?::


File: python.info,  Node: How stable is Python?,  Next: How many people are using Python?,  Up: Python in the real world

10.1.2.1 How stable is Python?
..............................

Very stable.  New, stable releases have been coming out roughly every 6
to 18 months since 1991, and this seems likely to continue.  As of
version 3.9, Python will have a new feature release every 12 months (
PEP 602(1)).

The developers issue bugfix releases of older versions, so the stability
of existing releases gradually improves.  Bugfix releases, indicated by
a third component of the version number (e.g.  3.5.3, 3.6.2), are
managed for stability; only fixes for known problems are included in a
bugfix release, and it’s guaranteed that interfaces will remain the same
throughout a series of bugfix releases.

The latest stable releases can always be found on the Python download
page(2).  Python 3.x is the recommended version and supported by most
widely used libraries.  Python 2.x is not maintained anymore(3).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0602/

   (2) https://www.python.org/downloads/

   (3) https://peps.python.org/pep-0373/


File: python.info,  Node: How many people are using Python?,  Next: Have any significant projects been done in Python?,  Prev: How stable is Python?,  Up: Python in the real world

10.1.2.2 How many people are using Python?
..........................................

There are probably millions of users, though it’s difficult to obtain an
exact count.

Python is available for free download, so there are no sales figures,
and it’s available from many different sites and packaged with many
Linux distributions, so download statistics don’t tell the whole story
either.

The comp.lang.python newsgroup is very active, but not all Python users
post to the group or even read it.


File: python.info,  Node: Have any significant projects been done in Python?,  Next: What new developments are expected for Python in the future?,  Prev: How many people are using Python?,  Up: Python in the real world

10.1.2.3 Have any significant projects been done in Python?
...........................................................

See ‘https://www.python.org/about/success’ for a list of projects that
use Python.  Consulting the proceedings for past Python conferences(1)
will reveal contributions from many different companies and
organizations.

High-profile Python projects include the Mailman mailing list manager(2)
and the Zope application server(3).  Several Linux distributions, most
notably Red Hat(4), have written part or all of their installer and
system administration software in Python.  Companies that use Python
internally include Google, Yahoo, and Lucasfilm Ltd.

   ---------- Footnotes ----------

   (1) https://www.python.org/community/workshops/

   (2) https://www.list.org

   (3) https://www.zope.dev

   (4) https://www.redhat.com


File: python.info,  Node: What new developments are expected for Python in the future?,  Next: Is it reasonable to propose incompatible changes to Python?,  Prev: Have any significant projects been done in Python?,  Up: Python in the real world

10.1.2.4 What new developments are expected for Python in the future?
.....................................................................

See ‘https://peps.python.org/’ for the Python Enhancement Proposals
(PEPs).  PEPs are design documents describing a suggested new feature
for Python, providing a concise technical specification and a rationale.
Look for a PEP titled «Python X.Y Release Schedule», where X.Y is a
version that hasn’t been publicly released yet.

New development is discussed on the python-dev mailing list(1).

   ---------- Footnotes ----------

   (1) https://mail.python.org/mailman3/lists/python-dev.python.org/


File: python.info,  Node: Is it reasonable to propose incompatible changes to Python?,  Next: Is Python a good language for beginning programmers?,  Prev: What new developments are expected for Python in the future?,  Up: Python in the real world

10.1.2.5 Is it reasonable to propose incompatible changes to Python?
....................................................................

In general, no.  There are already millions of lines of Python code
around the world, so any change in the language that invalidates more
than a very small fraction of existing programs has to be frowned upon.
Even if you can provide a conversion program, there’s still the problem
of updating all documentation; many books have been written about
Python, and we don’t want to invalidate them all at a single stroke.

Providing a gradual upgrade path is necessary if a feature has to be
changed.  PEP 5(1) describes the procedure followed for introducing
backward-incompatible changes while minimizing disruption for users.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0005/


File: python.info,  Node: Is Python a good language for beginning programmers?,  Prev: Is it reasonable to propose incompatible changes to Python?,  Up: Python in the real world

10.1.2.6 Is Python a good language for beginning programmers?
.............................................................

Yes.

It is still common to start students with a procedural and statically
typed language such as Pascal, C, or a subset of C++ or Java.  Students
may be better served by learning Python as their first language.  Python
has a very simple and consistent syntax and a large standard library
and, most importantly, using Python in a beginning programming course
lets students concentrate on important programming skills such as
problem decomposition and data type design.  With Python, students can
be quickly introduced to basic concepts such as loops and procedures.
They can probably even work with user-defined objects in their very
first course.

For a student who has never programmed before, using a statically typed
language seems unnatural.  It presents additional complexity that the
student must master and slows the pace of the course.  The students are
trying to learn to think like a computer, decompose problems, design
consistent interfaces, and encapsulate data.  While learning to use a
statically typed language is important in the long term, it is not
necessarily the best topic to address in the students” first programming
course.

Many other aspects of Python make it a good first language.  Like Java,
Python has a large standard library so that students can be assigned
programming projects very early in the course that 'do' something.
Assignments aren’t restricted to the standard four-function calculator
and check balancing programs.  By using the standard library, students
can gain the satisfaction of working on realistic applications as they
learn the fundamentals of programming.  Using the standard library also
teaches students about code reuse.  Third-party modules such as PyGame
are also helpful in extending the students” reach.

Python’s interactive interpreter enables students to test language
features while they’re programming.  They can keep a window with the
interpreter running while they enter their program’s source in another
window.  If they can’t remember the methods for a list, they can do
something like this:

     >>> L = []
     >>> dir(L)
     ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
     '__dir__', '__doc__', '__eq__', '__format__', '__ge__',
     '__getattribute__', '__getitem__', '__gt__', '__hash__', '__iadd__',
     '__imul__', '__init__', '__iter__', '__le__', '__len__', '__lt__',
     '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__',
     '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__',
     '__sizeof__', '__str__', '__subclasshook__', 'append', 'clear',
     'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
     'reverse', 'sort']
     >>> [d for d in dir(L) if '__' not in d]
     ['append', 'clear', 'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']

     >>> help(L.append)
     Help on built-in function append:

     append(...)
         L.append(object) -> None -- append object to end

     >>> L.append(1)
     >>> L
     [1]

With the interpreter, documentation is never far from the student as
they are programming.

There are also good IDEs for Python.  IDLE is a cross-platform IDE for
Python that is written in Python using Tkinter.  Emacs users will be
happy to know that there is a very good Python mode for Emacs.  All of
these programming environments provide syntax highlighting,
auto-indenting, and access to the interactive interpreter while coding.
Consult the Python wiki(1) for a full list of Python editing
environments.

If you want to discuss Python’s use in education, you may be interested
in joining the edu-sig mailing list(2).

   ---------- Footnotes ----------

   (1) https://wiki.python.org/moin/PythonEditors

   (2) https://www.python.org/community/sigs/current/edu-sig


File: python.info,  Node: Programming FAQ,  Next: Design and History FAQ,  Prev: General Python FAQ,  Up: Python Frequently Asked Questions

10.2 Programming FAQ
====================

* Menu:

* General Questions::
* Core Language::
* Numbers and strings::
* Performance: Performance<4>.
* Sequences (Tuples/Lists): Sequences Tuples/Lists.
* Objects::
* Modules: Modules<3>.


File: python.info,  Node: General Questions,  Next: Core Language,  Up: Programming FAQ

10.2.1 General Questions
------------------------

* Menu:

* Is there a source code level debugger with breakpoints, single-stepping, etc.?: Is there a source code level debugger with breakpoints single-stepping etc ?.
* Are there tools to help find bugs or perform static analysis?::
* How can I create a stand-alone binary from a Python script?::
* Are there coding standards or a style guide for Python programs?::


File: python.info,  Node: Is there a source code level debugger with breakpoints single-stepping etc ?,  Next: Are there tools to help find bugs or perform static analysis?,  Up: General Questions

10.2.1.1 Is there a source code level debugger with breakpoints, single-stepping, etc.?
.......................................................................................

Yes.

Several debuggers for Python are described below, and the built-in
function *note breakpoint(): 271. allows you to drop into any of them.

The pdb module is a simple but adequate console-mode debugger for
Python.  It is part of the standard Python library, and is *note
documented in the Library Reference Manual: aa.  You can also write your
own debugger by using the code for pdb as an example.

The IDLE interactive development environment, which is part of the
standard Python distribution (normally available as
Tools/scripts/idle3(1)), includes a graphical debugger.

PythonWin is a Python IDE that includes a GUI debugger based on pdb.
The PythonWin debugger colors breakpoints and has quite a few cool
features such as debugging non-PythonWin programs.  PythonWin is
available as part of pywin32(2) project and as a part of the
ActivePython(3) distribution.

Eric(4) is an IDE built on PyQt and the Scintilla editing component.

trepan3k(5) is a gdb-like debugger.

Visual Studio Code(6) is an IDE with debugging tools that integrates
with version-control software.

There are a number of commercial Python IDEs that include graphical
debuggers.  They include:

   * Wing IDE(7)

   * Komodo IDE(8)

   * PyCharm(9)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/blob/main/Tools/scripts/idle3

   (2) https://github.com/mhammond/pywin32

   (3) https://www.activestate.com/products/python/

   (4) https://eric-ide.python-projects.org/

   (5) https://github.com/rocky/python3-trepan/

   (6) https://code.visualstudio.com/

   (7) https://wingware.com/

   (8) https://www.activestate.com/products/komodo-ide/

   (9) https://www.jetbrains.com/pycharm/


File: python.info,  Node: Are there tools to help find bugs or perform static analysis?,  Next: How can I create a stand-alone binary from a Python script?,  Prev: Is there a source code level debugger with breakpoints single-stepping etc ?,  Up: General Questions

10.2.1.2 Are there tools to help find bugs or perform static analysis?
......................................................................

Yes.

Pylint(1) and Pyflakes(2) do basic checking that will help you catch
bugs sooner.

Static type checkers such as Mypy(3), Pyre(4), and Pytype(5) can check
type hints in Python source code.

   ---------- Footnotes ----------

   (1) https://pylint.pycqa.org/en/latest/index.html

   (2) https://github.com/PyCQA/pyflakes

   (3) https://mypy-lang.org/

   (4) https://pyre-check.org/

   (5) https://github.com/google/pytype


File: python.info,  Node: How can I create a stand-alone binary from a Python script?,  Next: Are there coding standards or a style guide for Python programs?,  Prev: Are there tools to help find bugs or perform static analysis?,  Up: General Questions

10.2.1.3 How can I create a stand-alone binary from a Python script?
....................................................................

You don’t need the ability to compile Python to C code if all you want
is a stand-alone program that users can download and run without having
to install the Python distribution first.  There are a number of tools
that determine the set of modules required by a program and bind these
modules together with a Python binary to produce a single executable.

One is to use the freeze tool, which is included in the Python source
tree as Tools/freeze(1).  It converts Python byte code to C arrays; with
a C compiler you can embed all your modules into a new program, which is
then linked with the standard Python modules.

It works by scanning your source recursively for import statements (in
both forms) and looking for the modules in the standard Python path as
well as in the source directory (for built-in modules).  It then turns
the bytecode for modules written in Python into C code (array
initializers that can be turned into code objects using the marshal
module) and creates a custom-made config file that only contains those
built-in modules which are actually used in the program.  It then
compiles the generated C code and links it with the rest of the Python
interpreter to form a self-contained binary which acts exactly like your
script.

The following packages can help with the creation of console and GUI
executables:

   * Nuitka(2) (Cross-platform)

   * PyInstaller(3) (Cross-platform)

   * PyOxidizer(4) (Cross-platform)

   * cx_Freeze(5) (Cross-platform)

   * py2app(6) (macOS only)

   * py2exe(7) (Windows only)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/main/Tools/freeze

   (2) https://nuitka.net/

   (3) https://pyinstaller.org/

   (4) https://pyoxidizer.readthedocs.io/en/stable/

   (5) https://marcelotduarte.github.io/cx_Freeze/

   (6) https://github.com/ronaldoussoren/py2app

   (7) https://www.py2exe.org/


File: python.info,  Node: Are there coding standards or a style guide for Python programs?,  Prev: How can I create a stand-alone binary from a Python script?,  Up: General Questions

10.2.1.4 Are there coding standards or a style guide for Python programs?
.........................................................................

Yes.  The coding style required for standard library modules is
documented as PEP 8(1).

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0008/


File: python.info,  Node: Core Language,  Next: Numbers and strings,  Prev: General Questions,  Up: Programming FAQ

10.2.2 Core Language
--------------------

* Menu:

* Why am I getting an UnboundLocalError when the variable has a value?::
* What are the rules for local and global variables in Python?::
* Why do lambdas defined in a loop with different values all return the same result?::
* How do I share global variables across modules?::
* What are the «best practices» for using import in a module?::
* Why are default values shared between objects?::
* How can I pass optional or keyword parameters from one function to another?::
* What is the difference between arguments and parameters?::
* Why did changing list “y” also change list “x”?::
* How do I write a function with output parameters (call by reference)?: How do I write a function with output parameters call by reference ?.
* How do you make a higher order function in Python?::
* How do I copy an object in Python?::
* How can I find the methods or attributes of an object?::
* How can my code discover the name of an object?::
* What’s up with the comma operator’s precedence?::
* Is there an equivalent of C’s «?;» ternary operator?: Is there an equivalent of C’s «? » ternary operator?.
* Is it possible to write obfuscated one-liners in Python?::
* What does the slash(/) in the parameter list of a function mean?: What does the slash / in the parameter list of a function mean?.


File: python.info,  Node: Why am I getting an UnboundLocalError when the variable has a value?,  Next: What are the rules for local and global variables in Python?,  Up: Core Language

10.2.2.1 Why am I getting an UnboundLocalError when the variable has a value?
.............................................................................

It can be a surprise to get the *note UnboundLocalError: 173d. in
previously working code when it is modified by adding an assignment
statement somewhere in the body of a function.

This code:

     >>> x = 10
     >>> def bar():
     ...     print(x)
     ...
     >>> bar()
     10

works, but this code:

     >>> x = 10
     >>> def foo():
     ...     print(x)
     ...     x += 1

results in an ‘UnboundLocalError’:

     >>> foo()
     Traceback (most recent call last):
       ...
     UnboundLocalError: local variable 'x' referenced before assignment

This is because when you make an assignment to a variable in a scope,
that variable becomes local to that scope and shadows any similarly
named variable in the outer scope.  Since the last statement in foo
assigns a new value to ‘x’, the compiler recognizes it as a local
variable.  Consequently when the earlier ‘print(x)’ attempts to print
the uninitialized local variable and an error results.

In the example above you can access the outer scope variable by
declaring it global:

     >>> x = 10
     >>> def foobar():
     ...     global x
     ...     print(x)
     ...     x += 1
     ...
     >>> foobar()
     10

This explicit declaration is required in order to remind you that
(unlike the superficially analogous situation with class and instance
variables) you are actually modifying the value of the variable in the
outer scope:

     >>> print(x)
     11

You can do a similar thing in a nested scope using the *note nonlocal:
14af. keyword:

     >>> def foo():
     ...    x = 10
     ...    def bar():
     ...        nonlocal x
     ...        print(x)
     ...        x += 1
     ...    bar()
     ...    print(x)
     ...
     >>> foo()
     10
     11


File: python.info,  Node: What are the rules for local and global variables in Python?,  Next: Why do lambdas defined in a loop with different values all return the same result?,  Prev: Why am I getting an UnboundLocalError when the variable has a value?,  Up: Core Language

10.2.2.2 What are the rules for local and global variables in Python?
.....................................................................

In Python, variables that are only referenced inside a function are
implicitly global.  If a variable is assigned a value anywhere within
the function’s body, it’s assumed to be a local unless explicitly
declared as global.

Though a bit surprising at first, a moment’s consideration explains
this.  On one hand, requiring *note global: 4ad. for assigned variables
provides a bar against unintended side-effects.  On the other hand, if
‘global’ was required for all global references, you’d be using ‘global’
all the time.  You’d have to declare as global every reference to a
built-in function or to a component of an imported module.  This clutter
would defeat the usefulness of the ‘global’ declaration for identifying
side-effects.


File: python.info,  Node: Why do lambdas defined in a loop with different values all return the same result?,  Next: How do I share global variables across modules?,  Prev: What are the rules for local and global variables in Python?,  Up: Core Language

10.2.2.3 Why do lambdas defined in a loop with different values all return the same result?
...........................................................................................

Assume you use a for loop to define a few different lambdas (or even
plain functions), e.g.:

     >>> squares = []
     >>> for x in range(5):
     ...     squares.append(lambda: x**2)

This gives you a list that contains 5 lambdas that calculate ‘x**2’.
You might expect that, when called, they would return, respectively,
‘0’, ‘1’, ‘4’, ‘9’, and ‘16’.  However, when you actually try you will
see that they all return ‘16’:

     >>> squares[2]()
     16
     >>> squares[4]()
     16

This happens because ‘x’ is not local to the lambdas, but is defined in
the outer scope, and it is accessed when the lambda is called — not when
it is defined.  At the end of the loop, the value of ‘x’ is ‘4’, so all
the functions now return ‘4**2’, i.e.  ‘16’.  You can also verify this
by changing the value of ‘x’ and see how the results of the lambdas
change:

     >>> x = 8
     >>> squares[2]()
     64

In order to avoid this, you need to save the values in variables local
to the lambdas, so that they don’t rely on the value of the global ‘x’:

     >>> squares = []
     >>> for x in range(5):
     ...     squares.append(lambda n=x: n**2)

Here, ‘n=x’ creates a new variable ‘n’ local to the lambda and computed
when the lambda is defined so that it has the same value that ‘x’ had at
that point in the loop.  This means that the value of ‘n’ will be ‘0’ in
the first lambda, ‘1’ in the second, ‘2’ in the third, and so on.
Therefore each lambda will now return the correct result:

     >>> squares[2]()
     4
     >>> squares[4]()
     16

Note that this behaviour is not peculiar to lambdas, but applies to
regular functions too.


File: python.info,  Node: How do I share global variables across modules?,  Next: What are the «best practices» for using import in a module?,  Prev: Why do lambdas defined in a loop with different values all return the same result?,  Up: Core Language

10.2.2.4 How do I share global variables across modules?
........................................................

The canonical way to share information across modules within a single
program is to create a special module (often called config or cfg).
Just import the config module in all modules of your application; the
module then becomes available as a global name.  Because there is only
one instance of each module, any changes made to the module object get
reflected everywhere.  For example:

config.py:

     x = 0   # Default value of the 'x' configuration setting

mod.py:

     import config
     config.x = 1

main.py:

     import config
     import mod
     print(config.x)

Note that using a module is also the basis for implementing the
singleton design pattern, for the same reason.


File: python.info,  Node: What are the «best practices» for using import in a module?,  Next: Why are default values shared between objects?,  Prev: How do I share global variables across modules?,  Up: Core Language

10.2.2.5 What are the «best practices» for using import in a module?
....................................................................

In general, don’t use ‘from modulename import *’.  Doing so clutters the
importer’s namespace, and makes it much harder for linters to detect
undefined names.

Import modules at the top of a file.  Doing so makes it clear what other
modules your code requires and avoids questions of whether the module
name is in scope.  Using one import per line makes it easy to add and
delete module imports, but using multiple imports per line uses less
screen space.

It’s good practice if you import modules in the following order:

  1. standard library modules – e.g.  *note sys: df, *note os: a5, *note
     argparse: 7, *note re: be.

  2. third-party library modules (anything installed in Python’s
     site-packages directory) – e.g.  ‘dateutil’, ‘requests’,
     ‘PIL.Image’

  3. locally developed modules

It is sometimes necessary to move imports to a function or class to
avoid problems with circular imports.  Gordon McMillan says:

     Circular imports are fine where both modules use the «import
     <module>» form of import.  They fail when the 2nd module wants to
     grab a name out of the first («from module import name») and the
     import is at the top level.  That’s because names in the 1st are
     not yet available, because the first module is busy importing the
     2nd.

In this case, if the second module is only used in one function, then
the import can easily be moved into that function.  By the time the
import is called, the first module will have finished initializing, and
the second module can do its import.

It may also be necessary to move imports out of the top level of code if
some of the modules are platform-specific.  In that case, it may not
even be possible to import all of the modules at the top of the file.
In this case, importing the correct modules in the corresponding
platform-specific code is a good option.

Only move imports into a local scope, such as inside a function
definition, if it’s necessary to solve a problem such as avoiding a
circular import or are trying to reduce the initialization time of a
module.  This technique is especially helpful if many of the imports are
unnecessary depending on how the program executes.  You may also want to
move imports into a function if the modules are only ever used in that
function.  Note that loading a module the first time may be expensive
because of the one time initialization of the module, but loading a
module multiple times is virtually free, costing only a couple of
dictionary lookups.  Even if the module name has gone out of scope, the
module is probably available in *note sys.modules: 17ce.


File: python.info,  Node: Why are default values shared between objects?,  Next: How can I pass optional or keyword parameters from one function to another?,  Prev: What are the «best practices» for using import in a module?,  Up: Core Language

10.2.2.6 Why are default values shared between objects?
.......................................................

This type of bug commonly bites neophyte programmers.  Consider this
function:

     def foo(mydict={}):  # Danger: shared reference to one dict for all calls
         ... compute something ...
         mydict[key] = value
         return mydict

The first time you call this function, ‘mydict’ contains a single item.
The second time, ‘mydict’ contains two items because when ‘foo()’ begins
executing, ‘mydict’ starts out with an item already in it.

It is often expected that a function call creates new objects for
default values.  This is not what happens.  Default values are created
exactly once, when the function is defined.  If that object is changed,
like the dictionary in this example, subsequent calls to the function
will refer to this changed object.

By definition, immutable objects such as numbers, strings, tuples, and
‘None’, are safe from change.  Changes to mutable objects such as
dictionaries, lists, and class instances can lead to confusion.

Because of this feature, it is good programming practice to not use
mutable objects as default values.  Instead, use ‘None’ as the default
value and inside the function, check if the parameter is ‘None’ and
create a new list/dictionary/whatever if it is.  For example, don’t
write:

     def foo(mydict={}):
         ...

but:

     def foo(mydict=None):
         if mydict is None:
             mydict = {}  # create a new dict for local namespace

This feature can be useful.  When you have a function that’s
time-consuming to compute, a common technique is to cache the parameters
and the resulting value of each call to the function, and return the
cached value if the same value is requested again.  This is called
«memoizing», and can be implemented like this:

     # Callers can only provide two parameters and optionally pass _cache by keyword
     def expensive(arg1, arg2, *, _cache={}):
         if (arg1, arg2) in _cache:
             return _cache[(arg1, arg2)]

         # Calculate the value
         result = ... expensive computation ...
         _cache[(arg1, arg2)] = result           # Store result in the cache
         return result

You could use a global variable containing a dictionary instead of the
default value; it’s a matter of taste.


File: python.info,  Node: How can I pass optional or keyword parameters from one function to another?,  Next: What is the difference between arguments and parameters?,  Prev: Why are default values shared between objects?,  Up: Core Language

10.2.2.7 How can I pass optional or keyword parameters from one function to another?
....................................................................................

Collect the arguments using the ‘*’ and ‘**’ specifiers in the
function’s parameter list; this gives you the positional arguments as a
tuple and the keyword arguments as a dictionary.  You can then pass
these arguments when calling another function by using ‘*’ and ‘**’:

     def f(x, *args, **kwargs):
         ...
         kwargs['width'] = '14.3c'
         ...
         g(x, *args, **kwargs)


File: python.info,  Node: What is the difference between arguments and parameters?,  Next: Why did changing list “y” also change list “x”?,  Prev: How can I pass optional or keyword parameters from one function to another?,  Up: Core Language

10.2.2.8 What is the difference between arguments and parameters?
.................................................................

*note Parameters: 2332. are defined by the names that appear in a
function definition, whereas *note arguments: 67b. are the values
actually passed to a function when calling it.  Parameters define what
*note kind of arguments: 2332. a function can accept.  For example,
given the function definition:

     def func(foo, bar=None, **kwargs):
         pass

'foo', 'bar' and 'kwargs' are parameters of ‘func’.  However, when
calling ‘func’, for example:

     func(42, bar=314, extra=somevar)

the values ‘42’, ‘314’, and ‘somevar’ are arguments.


File: python.info,  Node: Why did changing list “y” also change list “x”?,  Next: How do I write a function with output parameters call by reference ?,  Prev: What is the difference between arguments and parameters?,  Up: Core Language

10.2.2.9 Why did changing list “y” also change list “x”?
........................................................

If you wrote code like:

     >>> x = []
     >>> y = x
     >>> y.append(10)
     >>> y
     [10]
     >>> x
     [10]

you might be wondering why appending an element to ‘y’ changed ‘x’ too.

There are two factors that produce this result:

  1. Variables are simply names that refer to objects.  Doing ‘y = x’
     doesn’t create a copy of the list – it creates a new variable ‘y’
     that refers to the same object ‘x’ refers to.  This means that
     there is only one object (the list), and both ‘x’ and ‘y’ refer to
     it.

  2. Lists are *note mutable: 1fcd, which means that you can change
     their content.

After the call to *note append(): 23bc, the content of the mutable
object has changed from ‘[]’ to ‘[10]’.  Since both the variables refer
to the same object, using either name accesses the modified value
‘[10]’.

If we instead assign an immutable object to ‘x’:

     >>> x = 5  # ints are immutable
     >>> y = x
     >>> x = x + 1  # 5 can't be mutated, we are creating a new object here
     >>> x
     6
     >>> y
     5

we can see that in this case ‘x’ and ‘y’ are not equal anymore.  This is
because integers are *note immutable: 1fc8, and when we do ‘x = x + 1’
we are not mutating the int ‘5’ by incrementing its value; instead, we
are creating a new object (the int ‘6’) and assigning it to ‘x’ (that
is, changing which object ‘x’ refers to).  After this assignment we have
two objects (the ints ‘6’ and ‘5’) and two variables that refer to them
(‘x’ now refers to ‘6’ but ‘y’ still refers to ‘5’).

Some operations (for example ‘y.append(10)’ and ‘y.sort()’) mutate the
object, whereas superficially similar operations (for example ‘y = y +
[10]’ and *note sorted(y): dc9.) create a new object.  In general in
Python (and in all cases in the standard library) a method that mutates
an object will return ‘None’ to help avoid getting the two types of
operations confused.  So if you mistakenly write ‘y.sort()’ thinking it
will give you a sorted copy of ‘y’, you’ll instead end up with ‘None’,
which will likely cause your program to generate an easily diagnosed
error.

However, there is one class of operations where the same operation
sometimes has different behaviors with different types: the augmented
assignment operators.  For example, ‘+=’ mutates lists but not tuples or
ints (‘a_list += [1, 2, 3]’ is equivalent to ‘a_list.extend([1, 2, 3])’
and mutates ‘a_list’, whereas ‘some_tuple += (1, 2, 3)’ and ‘some_int +=
1’ create new objects).

In other words:

   * If we have a mutable object (*note list: 24d, *note dict: 183,
     *note set: 184, etc.), we can use some specific operations to
     mutate it and all the variables that refer to it will see the
     change.

   * If we have an immutable object (*note str: 169, *note int: 19b,
     *note tuple: 614, etc.), all the variables that refer to it will
     always see the same value, but operations that transform that value
     into a new value always return a new object.

If you want to know if two variables refer to the same object or not,
you can use the *note is: 34c. operator, or the built-in function *note
id(): 162a.


File: python.info,  Node: How do I write a function with output parameters call by reference ?,  Next: How do you make a higher order function in Python?,  Prev: Why did changing list “y” also change list “x”?,  Up: Core Language

10.2.2.10 How do I write a function with output parameters (call by reference)?
...............................................................................

Remember that arguments are passed by assignment in Python.  Since
assignment just creates references to objects, there’s no alias between
an argument name in the caller and callee, and so no call-by-reference
per se.  You can achieve the desired effect in a number of ways.

  1. By returning a tuple of the results:

          >>> def func1(a, b):
          ...     a = 'new-value'        # a and b are local names
          ...     b = b + 1              # assigned to new objects
          ...     return a, b            # return new values
          ...
          >>> x, y = 'old-value', 99
          >>> func1(x, y)
          ('new-value', 100)

     This is almost always the clearest solution.

  2. By using global variables.  This isn’t thread-safe, and is not
     recommended.

  3. By passing a mutable (changeable in-place) object:

          >>> def func2(a):
          ...     a[0] = 'new-value'     # 'a' references a mutable list
          ...     a[1] = a[1] + 1        # changes a shared object
          ...
          >>> args = ['old-value', 99]
          >>> func2(args)
          >>> args
          ['new-value', 100]

  4. By passing in a dictionary that gets mutated:

          >>> def func3(args):
          ...     args['a'] = 'new-value'     # args is a mutable dictionary
          ...     args['b'] = args['b'] + 1   # change it in-place
          ...
          >>> args = {'a': 'old-value', 'b': 99}
          >>> func3(args)
          >>> args
          {'a': 'new-value', 'b': 100}

  5. Or bundle up values in a class instance:

          >>> class Namespace:
          ...     def __init__(self, /, **args):
          ...         for key, value in args.items():
          ...             setattr(self, key, value)
          ...
          >>> def func4(args):
          ...     args.a = 'new-value'        # args is a mutable Namespace
          ...     args.b = args.b + 1         # change object in-place
          ...
          >>> args = Namespace(a='old-value', b=99)
          >>> func4(args)
          >>> vars(args)
          {'a': 'new-value', 'b': 100}

     There’s almost never a good reason to get this complicated.

Your best choice is to return a tuple containing the multiple results.


File: python.info,  Node: How do you make a higher order function in Python?,  Next: How do I copy an object in Python?,  Prev: How do I write a function with output parameters call by reference ?,  Up: Core Language

10.2.2.11 How do you make a higher order function in Python?
............................................................

You have two choices: you can use nested scopes or you can use callable
objects.  For example, suppose you wanted to define ‘linear(a,b)’ which
returns a function ‘f(x)’ that computes the value ‘a*x+b’.  Using nested
scopes:

     def linear(a, b):
         def result(x):
             return a * x + b
         return result

Or using a callable object:

     class linear:

         def __init__(self, a, b):
             self.a, self.b = a, b

         def __call__(self, x):
             return self.a * x + self.b

In both cases,

     taxes = linear(0.3, 2)

gives a callable object where ‘taxes(10e6) == 0.3 * 10e6 + 2’.

The callable object approach has the disadvantage that it is a bit
slower and results in slightly longer code.  However, note that a
collection of callables can share their signature via inheritance:

     class exponential(linear):
         # __init__ inherited
         def __call__(self, x):
             return self.a * (x ** self.b)

Object can encapsulate state for several methods:

     class counter:

         value = 0

         def set(self, x):
             self.value = x

         def up(self):
             self.value = self.value + 1

         def down(self):
             self.value = self.value - 1

     count = counter()
     inc, dec, reset = count.up, count.down, count.set

Here ‘inc()’, ‘dec()’ and ‘reset()’ act like functions which share the
same counting variable.


File: python.info,  Node: How do I copy an object in Python?,  Next: How can I find the methods or attributes of an object?,  Prev: How do you make a higher order function in Python?,  Up: Core Language

10.2.2.12 How do I copy an object in Python?
............................................

In general, try *note copy.copy(): 758. or *note copy.deepcopy(): d67.
for the general case.  Not all objects can be copied, but most can.

Some objects can be copied more easily.  Dictionaries have a *note
copy(): dcb. method:

     newdict = olddict.copy()

Sequences can be copied by slicing:

     new_l = l[:]


File: python.info,  Node: How can I find the methods or attributes of an object?,  Next: How can my code discover the name of an object?,  Prev: How do I copy an object in Python?,  Up: Core Language

10.2.2.13 How can I find the methods or attributes of an object?
................................................................

For an instance ‘x’ of a user-defined class, *note dir(x): 845. returns
an alphabetized list of the names containing the instance attributes and
methods and attributes defined by its class.


File: python.info,  Node: How can my code discover the name of an object?,  Next: What’s up with the comma operator’s precedence?,  Prev: How can I find the methods or attributes of an object?,  Up: Core Language

10.2.2.14 How can my code discover the name of an object?
.........................................................

Generally speaking, it can’t, because objects don’t really have names.
Essentially, assignment always binds a name to a value; the same is true
of ‘def’ and ‘class’ statements, but in that case the value is a
callable.  Consider the following code:

     >>> class A:
     ...     pass
     ...
     >>> B = A
     >>> a = B()
     >>> b = a
     >>> print(b)
     <__main__.A object at 0x16D07CC>
     >>> print(a)
     <__main__.A object at 0x16D07CC>

Arguably the class has a name: even though it is bound to two names and
invoked through the name ‘B’ the created instance is still reported as
an instance of class ‘A’.  However, it is impossible to say whether the
instance’s name is ‘a’ or ‘b’, since both names are bound to the same
value.

Generally speaking it should not be necessary for your code to «know the
names» of particular values.  Unless you are deliberately writing
introspective programs, this is usually an indication that a change of
approach might be beneficial.

In comp.lang.python, Fredrik Lundh once gave an excellent analogy in
answer to this question:

     The same way as you get the name of that cat you found on your
     porch: the cat (object) itself cannot tell you its name, and it
     doesn’t really care – so the only way to find out what it’s called
     is to ask all your neighbours (namespaces) if it’s their cat
     (object)…

     ….and don’t be surprised if you’ll find that it’s known by many
     names, or no name at all!


File: python.info,  Node: What’s up with the comma operator’s precedence?,  Next: Is there an equivalent of C’s «? » ternary operator?,  Prev: How can my code discover the name of an object?,  Up: Core Language

10.2.2.15 What’s up with the comma operator’s precedence?
.........................................................

Comma is not an operator in Python.  Consider this session:

     >>> "a" in "b", "a"
     (False, 'a')

Since the comma is not an operator, but a separator between expressions
the above is evaluated as if you had entered:

     ("a" in "b"), "a"

not:

     "a" in ("b", "a")

The same is true of the various assignment operators (‘=’, ‘+=’ etc).
They are not truly operators but syntactic delimiters in assignment
statements.


File: python.info,  Node: Is there an equivalent of C’s «? » ternary operator?,  Next: Is it possible to write obfuscated one-liners in Python?,  Prev: What’s up with the comma operator’s precedence?,  Up: Core Language

10.2.2.16 Is there an equivalent of C’s «?:» ternary operator?
..............................................................

Yes, there is.  The syntax is as follows:

     [on_true] if [expression] else [on_false]

     x, y = 50, 25
     small = x if x < y else y

Before this syntax was introduced in Python 2.5, a common idiom was to
use logical operators:

     [expression] and [on_true] or [on_false]

However, this idiom is unsafe, as it can give wrong results when
'on_true' has a false boolean value.  Therefore, it is always better to
use the ‘... if ... else ...’ form.


File: python.info,  Node: Is it possible to write obfuscated one-liners in Python?,  Next: What does the slash / in the parameter list of a function mean?,  Prev: Is there an equivalent of C’s «? » ternary operator?,  Up: Core Language

10.2.2.17 Is it possible to write obfuscated one-liners in Python?
..................................................................

Yes.  Usually this is done by nesting *note lambda: 14a5. within
‘lambda’.  See the following three examples, slightly adapted from Ulf
Bartelt:

     from functools import reduce

     # Primes < 1000
     print(list(filter(None,map(lambda y:y*reduce(lambda x,y:x*y!=0,
     map(lambda x,y=y:y%x,range(2,int(pow(y,0.5)+1))),1),range(2,1000)))))

     # First 10 Fibonacci numbers
     print(list(map(lambda x,f=lambda x,f:(f(x-1,f)+f(x-2,f)) if x>1 else 1:
     f(x,f), range(10))))

     # Mandelbrot set
     print((lambda Ru,Ro,Iu,Io,IM,Sx,Sy:reduce(lambda x,y:x+'\n'+y,map(lambda y,
     Iu=Iu,Io=Io,Ru=Ru,Ro=Ro,Sy=Sy,L=lambda yc,Iu=Iu,Io=Io,Ru=Ru,Ro=Ro,i=IM,
     Sx=Sx,Sy=Sy:reduce(lambda x,y:x+y,map(lambda x,xc=Ru,yc=yc,Ru=Ru,Ro=Ro,
     i=i,Sx=Sx,F=lambda xc,yc,x,y,k,f=lambda xc,yc,x,y,k,f:(k<=0)or (x*x+y*y
     >=4.0) or 1+f(xc,yc,x*x-y*y+xc,2.0*x*y+yc,k-1,f):f(xc,yc,x,y,k,f):chr(
     64+F(Ru+x*(Ro-Ru)/Sx,yc,0,0,i)),range(Sx))):L(Iu+y*(Io-Iu)/Sy),range(Sy
     ))))(-2.1, 0.7, -1.2, 1.2, 30, 80, 24))
     #    \___ ___/  \___ ___/  |   |   |__ lines on screen
     #        V          V      |   |______ columns on screen
     #        |          |      |__________ maximum of "iterations"
     #        |          |_________________ range on y axis
     #        |____________________________ range on x axis

Don’t try this at home, kids!


File: python.info,  Node: What does the slash / in the parameter list of a function mean?,  Prev: Is it possible to write obfuscated one-liners in Python?,  Up: Core Language

10.2.2.18 What does the slash(/) in the parameter list of a function mean?
..........................................................................

A slash in the argument list of a function denotes that the parameters
prior to it are positional-only.  Positional-only parameters are the
ones without an externally usable name.  Upon calling a function that
accepts positional-only parameters, arguments are mapped to parameters
based solely on their position.  For example, *note divmod(): b9b. is a
function that accepts positional-only parameters.  Its documentation
looks like this:

     >>> help(divmod)
     Help on built-in function divmod in module builtins:

     divmod(x, y, /)
         Return the tuple (x//y, x%y).  Invariant: div*y + mod == x.

The slash at the end of the parameter list means that both parameters
are positional-only.  Thus, calling *note divmod(): b9b. with keyword
arguments would lead to an error:

     >>> divmod(x=3, y=4)
     Traceback (most recent call last):
       File "<stdin>", line 1, in <module>
     TypeError: divmod() takes no keyword arguments


File: python.info,  Node: Numbers and strings,  Next: Performance<4>,  Prev: Core Language,  Up: Programming FAQ

10.2.3 Numbers and strings
--------------------------

* Menu:

* How do I specify hexadecimal and octal integers?::
* Why does -22 // 10 return -3?::
* How do I get int literal attribute instead of SyntaxError?::
* How do I convert a string to a number?::
* How do I convert a number to a string?::
* How do I modify a string in place?::
* How do I use strings to call functions/methods?::
* Is there an equivalent to Perl’s chomp() for removing trailing newlines from strings?: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?.
* Is there a scanf() or sscanf() equivalent?: Is there a scanf or sscanf equivalent?.
* What does UnicodeDecodeError or UnicodeEncodeError error mean?::
* Can I end a raw string with an odd number of backslashes?::


File: python.info,  Node: How do I specify hexadecimal and octal integers?,  Next: Why does -22 // 10 return -3?,  Up: Numbers and strings

10.2.3.1 How do I specify hexadecimal and octal integers?
.........................................................

To specify an octal digit, precede the octal value with a zero, and then
a lower or uppercase «o».  For example, to set the variable «a» to the
octal value «10» (8 in decimal), type:

     >>> a = 0o10
     >>> a
     8

Hexadecimal is just as easy.  Simply precede the hexadecimal number with
a zero, and then a lower or uppercase «x».  Hexadecimal digits can be
specified in lower or uppercase.  For example, in the Python
interpreter:

     >>> a = 0xa5
     >>> a
     165
     >>> b = 0XB2
     >>> b
     178


File: python.info,  Node: Why does -22 // 10 return -3?,  Next: How do I get int literal attribute instead of SyntaxError?,  Prev: How do I specify hexadecimal and octal integers?,  Up: Numbers and strings

10.2.3.2 Why does -22 // 10 return -3?
......................................

It’s primarily driven by the desire that ‘i % j’ have the same sign as
‘j’.  If you want that, and also want:

     i == (i // j) * j + (i % j)

then integer division has to return the floor.  C also requires that
identity to hold, and then compilers that truncate ‘i // j’ need to make
‘i % j’ have the same sign as ‘i’.

There are few real use cases for ‘i % j’ when ‘j’ is negative.  When ‘j’
is positive, there are many, and in virtually all of them it’s more
useful for ‘i % j’ to be ‘>= 0’.  If the clock says 10 now, what did it
say 200 hours ago?  ‘-190 % 12 == 2’ is useful; ‘-190 % 12 == -10’ is a
bug waiting to bite.


File: python.info,  Node: How do I get int literal attribute instead of SyntaxError?,  Next: How do I convert a string to a number?,  Prev: Why does -22 // 10 return -3?,  Up: Numbers and strings

10.2.3.3 How do I get int literal attribute instead of SyntaxError?
...................................................................

Trying to lookup an ‘int’ literal attribute in the normal manner gives a
*note SyntaxError: 18e. because the period is seen as a decimal point:

     >>> 1.__class__
       File "<stdin>", line 1
       1.__class__
        ^
     SyntaxError: invalid decimal literal

The solution is to separate the literal from the period with either a
space or parentheses.

     >>> 1 .__class__
     <class 'int'>
     >>> (1).__class__
     <class 'int'>


File: python.info,  Node: How do I convert a string to a number?,  Next: How do I convert a number to a string?,  Prev: How do I get int literal attribute instead of SyntaxError?,  Up: Numbers and strings

10.2.3.4 How do I convert a string to a number?
...............................................

For integers, use the built-in *note int(): 19b. type constructor, e.g.
‘int('144') == 144’.  Similarly, *note float(): 196. converts to a
floating-point number, e.g.  ‘float('144') == 144.0’.

By default, these interpret the number as decimal, so that ‘int('0144')
== 144’ holds true, and ‘int('0x144')’ raises *note ValueError: 2ec.
‘int(string, base)’ takes the base to convert from as a second optional
argument, so ‘int( '0x144', 16) == 324’.  If the base is specified as 0,
the number is interpreted using Python’s rules: a leading “0o” indicates
octal, and “0x” indicates a hex number.

Do not use the built-in function *note eval(): 4a4. if all you need is
to convert strings to numbers.  *note eval(): 4a4. will be significantly
slower and it presents a security risk: someone could pass you a Python
expression that might have unwanted side effects.  For example, someone
could pass ‘__import__('os').system("rm -rf $HOME")’ which would erase
your home directory.

*note eval(): 4a4. also has the effect of interpreting numbers as Python
expressions, so that e.g.  ‘eval('09')’ gives a syntax error because
Python does not allow leading “0” in a decimal number (except “0”).


File: python.info,  Node: How do I convert a number to a string?,  Next: How do I modify a string in place?,  Prev: How do I convert a string to a number?,  Up: Numbers and strings

10.2.3.5 How do I convert a number to a string?
...............................................

To convert, e.g., the number ‘144’ to the string ‘'144'’, use the
built-in type constructor *note str(): 169.  If you want a hexadecimal
or octal representation, use the built-in functions *note hex(): 14d7.
or *note oct(): 14d6.  For fancy formatting, see the *note f-strings:
19a. and *note Format String Syntax: 15a3. sections, e.g.
‘"{:04d}".format(144)’ yields ‘'0144'’ and ‘"{:.3f}".format(1.0/3.0)’
yields ‘'0.333'’.


File: python.info,  Node: How do I modify a string in place?,  Next: How do I use strings to call functions/methods?,  Prev: How do I convert a number to a string?,  Up: Numbers and strings

10.2.3.6 How do I modify a string in place?
...........................................

You can’t, because strings are immutable.  In most situations, you
should simply construct a new string from the various parts you want to
assemble it from.  However, if you need an object with the ability to
modify in-place unicode data, try using an *note io.StringIO: 112b.
object or the *note array: 8. module:

     >>> import io
     >>> s = "Hello, world"
     >>> sio = io.StringIO(s)
     >>> sio.getvalue()
     'Hello, world'
     >>> sio.seek(7)
     7
     >>> sio.write("there!")
     6
     >>> sio.getvalue()
     'Hello, there!'

     >>> import array
     >>> a = array.array('w', s)
     >>> print(a)
     array('w', 'Hello, world')
     >>> a[0] = 'y'
     >>> print(a)
     array('w', 'yello, world')
     >>> a.tounicode()
     'yello, world'


File: python.info,  Node: How do I use strings to call functions/methods?,  Next: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?,  Prev: How do I modify a string in place?,  Up: Numbers and strings

10.2.3.7 How do I use strings to call functions/methods?
........................................................

There are various techniques.

   * The best is to use a dictionary that maps strings to functions.
     The primary advantage of this technique is that the strings do not
     need to match the names of the functions.  This is also the primary
     technique used to emulate a case construct:

          def a():
              pass

          def b():
              pass

          dispatch = {'go': a, 'stop': b}  # Note lack of parens for funcs

          dispatch[get_input()]()  # Note trailing parens to call function

   * Use the built-in function *note getattr(): dcc.:

          import foo
          getattr(foo, 'bar')()

     Note that *note getattr(): dcc. works on any object, including
     classes, class instances, modules, and so on.

     This is used in several places in the standard library, like this:

          class Foo:
              def do_foo(self):
                  ...

              def do_bar(self):
                  ...

          f = getattr(foo_instance, 'do_' + opname)
          f()

   * Use *note locals(): 46f. to resolve the function name:

          def myFunc():
              print("hello")

          fname = "myFunc"

          f = locals()[fname]
          f()


File: python.info,  Node: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?,  Next: Is there a scanf or sscanf equivalent?,  Prev: How do I use strings to call functions/methods?,  Up: Numbers and strings

10.2.3.8 Is there an equivalent to Perl’s ‘chomp()’ for removing trailing newlines from strings?
................................................................................................

You can use ‘S.rstrip("\r\n")’ to remove all occurrences of any line
terminator from the end of the string ‘S’ without removing other
trailing whitespace.  If the string ‘S’ represents more than one line,
with several empty lines at the end, the line terminators for all the
blank lines will be removed:

     >>> lines = ("line 1 \r\n"
     ...          "\r\n"
     ...          "\r\n")
     >>> lines.rstrip("\n\r")
     'line 1 '

Since this is typically only desired when reading text one line at a
time, using ‘S.rstrip()’ this way works well.


File: python.info,  Node: Is there a scanf or sscanf equivalent?,  Next: What does UnicodeDecodeError or UnicodeEncodeError error mean?,  Prev: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?,  Up: Numbers and strings

10.2.3.9 Is there a ‘scanf()’ or ‘sscanf()’ equivalent?
.......................................................

Not as such.

For simple input parsing, the easiest approach is usually to split the
line into whitespace-delimited words using the *note split(): 10ac.
method of string objects and then convert decimal strings to numeric
values using *note int(): 19b. or *note float(): 196.  ‘split()’
supports an optional «sep» parameter which is useful if the line uses
something other than whitespace as a separator.

For more complicated input parsing, regular expressions are more
powerful than C’s ‘sscanf’ and better suited for the task.


File: python.info,  Node: What does UnicodeDecodeError or UnicodeEncodeError error mean?,  Next: Can I end a raw string with an odd number of backslashes?,  Prev: Is there a scanf or sscanf equivalent?,  Up: Numbers and strings

10.2.3.10 What does ‘UnicodeDecodeError’ or ‘UnicodeEncodeError’ error mean?
............................................................................

See the *note Unicode HOWTO: 14ac.


File: python.info,  Node: Can I end a raw string with an odd number of backslashes?,  Prev: What does UnicodeDecodeError or UnicodeEncodeError error mean?,  Up: Numbers and strings

10.2.3.11 Can I end a raw string with an odd number of backslashes?
...................................................................

A raw string ending with an odd number of backslashes will escape the
string’s quote:

     >>> r'C:\this\will\not\work\'
       File "<stdin>", line 1
         r'C:\this\will\not\work\'
         ^
     SyntaxError: unterminated string literal (detected at line 1)

There are several workarounds for this.  One is to use regular strings
and double the backslashes:

     >>> 'C:\\this\\will\\work\\'
     'C:\\this\\will\\work\\'

Another is to concatenate a regular string containing an escaped
backslash to the raw string:

     >>> r'C:\this\will\work' '\\'
     'C:\\this\\will\\work\\'

It is also possible to use *note os.path.join(): 1991. to append a
backslash on Windows:

     >>> os.path.join(r'C:\this\will\work', '')
     'C:\\this\\will\\work\\'

Note that while a backslash will «escape» a quote for the purposes of
determining where the raw string ends, no escaping occurs when
interpreting the value of the raw string.  That is, the backslash
remains present in the value of the raw string:

     >>> r'backslash\'preserved'
     "backslash\\'preserved"

Also see the specification in the *note language reference: 2288.


File: python.info,  Node: Performance<4>,  Next: Sequences Tuples/Lists,  Prev: Numbers and strings,  Up: Programming FAQ

10.2.4 Performance
------------------

* Menu:

* My program is too slow. How do I speed it up?: My program is too slow How do I speed it up?.
* What is the most efficient way to concatenate many strings together?::


File: python.info,  Node: My program is too slow How do I speed it up?,  Next: What is the most efficient way to concatenate many strings together?,  Up: Performance<4>

10.2.4.1 My program is too slow. How do I speed it up?
......................................................

That’s a tough one, in general.  First, here are a list of things to
remember before diving further:

   * Performance characteristics vary across Python implementations.
     This FAQ focuses on *note CPython: 906.

   * Behaviour can vary across operating systems, especially when
     talking about I/O or multi-threading.

   * You should always find the hot spots in your program 'before'
     attempting to optimize any code (see the *note profile: b4.
     module).

   * Writing benchmark scripts will allow you to iterate quickly when
     searching for improvements (see the *note timeit: f5. module).

   * It is highly recommended to have good code coverage (through unit
     testing or any other technique) before potentially introducing
     regressions hidden in sophisticated optimizations.

That being said, there are many tricks to speed up Python code.  Here
are some general principles which go a long way towards reaching
acceptable performance levels:

   * Making your algorithms faster (or changing to faster ones) can
     yield much larger benefits than trying to sprinkle
     micro-optimization tricks all over your code.

   * Use the right data structures.  Study documentation for the *note
     Tipi incorporati: 25c8. and the *note collections: 1e. module.

   * When the standard library provides a primitive for doing something,
     it is likely (although not guaranteed) to be faster than any
     alternative you may come up with.  This is doubly true for
     primitives written in C, such as builtins and some extension types.
     For example, be sure to use either the *note list.sort(): dca.
     built-in method or the related *note sorted(): dc9. function to do
     sorting (and see the *note Sorting Techniques: 25bb. for examples
     of moderately advanced usage).

   * Abstractions tend to create indirections and force the interpreter
     to work more.  If the levels of indirection outweigh the amount of
     useful work done, your program will be slower.  You should avoid
     excessive abstraction, especially under the form of tiny functions
     or methods (which are also often detrimental to readability).

If you have reached the limit of what pure Python can allow, there are
tools to take you further away.  For example, Cython(1) can compile a
slightly modified version of Python code into a C extension, and can be
used on many different platforms.  Cython can take advantage of
compilation (and optional type annotations) to make your code
significantly faster than when interpreted.  If you are confident in
your C programming skills, you can also *note write a C extension
module: 1fa5. yourself.

Vedi anche
..........

The wiki page devoted to performance tips(2).

   ---------- Footnotes ----------

   (1) https://cython.org

   (2) https://wiki.python.org/moin/PythonSpeed/PerformanceTips


File: python.info,  Node: What is the most efficient way to concatenate many strings together?,  Prev: My program is too slow How do I speed it up?,  Up: Performance<4>

10.2.4.2 What is the most efficient way to concatenate many strings together?
.............................................................................

*note str: 169. and *note bytes: 192. objects are immutable, therefore
concatenating many strings together is inefficient as each concatenation
creates a new object.  In the general case, the total runtime cost is
quadratic in the total string length.

To accumulate many *note str: 169. objects, the recommended idiom is to
place them into a list and call *note str.join(): 25e8. at the end:

     chunks = []
     for s in my_strings:
         chunks.append(s)
     result = ''.join(chunks)

(another reasonably efficient idiom is to use *note io.StringIO: 112b.)

To accumulate many *note bytes: 192. objects, the recommended idiom is
to extend a *note bytearray: 344. object using in-place concatenation
(the ‘+=’ operator):

     result = bytearray()
     for b in my_bytes_objects:
         result += b


File: python.info,  Node: Sequences Tuples/Lists,  Next: Objects,  Prev: Performance<4>,  Up: Programming FAQ

10.2.5 Sequences (Tuples/Lists)
-------------------------------

* Menu:

* How do I convert between tuples and lists?::
* What’s a negative index?::
* How do I iterate over a sequence in reverse order?::
* How do you remove duplicates from a list?::
* How do you remove multiple items from a list?::
* How do you make an array in Python?::
* How do I create a multidimensional list?::
* How do I apply a method or function to a sequence of objects?::
* Why does a_tuple[i] += [“item”] raise an exception when the addition works?::
* I want to do a complicated sort; can you do a Schwartzian Transform in Python?: I want to do a complicated sort can you do a Schwartzian Transform in Python?.
* How can I sort one list by values from another list?::


File: python.info,  Node: How do I convert between tuples and lists?,  Next: What’s a negative index?,  Up: Sequences Tuples/Lists

10.2.5.1 How do I convert between tuples and lists?
...................................................

The type constructor ‘tuple(seq)’ converts any sequence (actually, any
iterable) into a tuple with the same items in the same order.

For example, ‘tuple([1, 2, 3])’ yields ‘(1, 2, 3)’ and ‘tuple('abc')’
yields ‘('a', 'b', 'c')’.  If the argument is a tuple, it does not make
a copy but returns the same object, so it is cheap to call *note
tuple(): 614. when you aren’t sure that an object is already a tuple.

The type constructor ‘list(seq)’ converts any sequence or iterable into
a list with the same items in the same order.  For example, ‘list((1, 2,
3))’ yields ‘[1, 2, 3]’ and ‘list('abc')’ yields ‘['a', 'b', 'c']’.  If
the argument is a list, it makes a copy just like ‘seq[:]’ would.


File: python.info,  Node: What’s a negative index?,  Next: How do I iterate over a sequence in reverse order?,  Prev: How do I convert between tuples and lists?,  Up: Sequences Tuples/Lists

10.2.5.2 What’s a negative index?
.................................

Python sequences are indexed with positive numbers and negative numbers.
For positive numbers 0 is the first index 1 is the second index and so
forth.  For negative indices -1 is the last index and -2 is the
penultimate (next to last) index and so forth.  Think of ‘seq[-n]’ as
the same as ‘seq[len(seq)-n]’.

Using negative indices can be very convenient.  For example ‘S[:-1]’ is
all of the string except for its last character, which is useful for
removing the trailing newline from a string.


File: python.info,  Node: How do I iterate over a sequence in reverse order?,  Next: How do you remove duplicates from a list?,  Prev: What’s a negative index?,  Up: Sequences Tuples/Lists

10.2.5.3 How do I iterate over a sequence in reverse order?
...........................................................

Use the *note reversed(): a67. built-in function:

     for x in reversed(sequence):
         ...  # do something with x ...

This won’t touch your original sequence, but build a new copy with
reversed order to iterate over.


File: python.info,  Node: How do you remove duplicates from a list?,  Next: How do you remove multiple items from a list?,  Prev: How do I iterate over a sequence in reverse order?,  Up: Sequences Tuples/Lists

10.2.5.4 How do you remove duplicates from a list?
..................................................

See the Python Cookbook for a long discussion of many ways to do this:

     ‘https://code.activestate.com/recipes/52560/’

If you don’t mind reordering the list, sort it and then scan from the
end of the list, deleting duplicates as you go:

     if mylist:
         mylist.sort()
         last = mylist[-1]
         for i in range(len(mylist)-2, -1, -1):
             if last == mylist[i]:
                 del mylist[i]
             else:
                 last = mylist[i]

If all elements of the list may be used as set keys (i.e.  they are all
*note hashable: 825.) this is often faster

     mylist = list(set(mylist))

This converts the list into a set, thereby removing duplicates, and then
back into a list.


File: python.info,  Node: How do you remove multiple items from a list?,  Next: How do you make an array in Python?,  Prev: How do you remove duplicates from a list?,  Up: Sequences Tuples/Lists

10.2.5.5 How do you remove multiple items from a list?
......................................................

As with removing duplicates, explicitly iterating in reverse with a
delete condition is one possibility.  However, it is easier and faster
to use slice replacement with an implicit or explicit forward iteration.
Here are three variations:

     mylist[:] = filter(keep_function, mylist)
     mylist[:] = (x for x in mylist if keep_condition)
     mylist[:] = [x for x in mylist if keep_condition]

The list comprehension may be fastest.


File: python.info,  Node: How do you make an array in Python?,  Next: How do I create a multidimensional list?,  Prev: How do you remove multiple items from a list?,  Up: Sequences Tuples/Lists

10.2.5.6 How do you make an array in Python?
............................................

Use a list:

     ["this", 1, "is", "an", "array"]

Lists are equivalent to C or Pascal arrays in their time complexity; the
primary difference is that a Python list can contain objects of many
different types.

The ‘array’ module also provides methods for creating arrays of fixed
types with compact representations, but they are slower to index than
lists.  Also note that NumPy(1) and other third party packages define
array-like structures with various characteristics as well.

To get Lisp-style linked lists, you can emulate 'cons cells' using
tuples:

     lisp_list = ("like",  ("this",  ("example", None) ) )

If mutability is desired, you could use lists instead of tuples.  Here
the analogue of a Lisp 'car' is ‘lisp_list[0]’ and the analogue of 'cdr'
is ‘lisp_list[1]’.  Only do this if you’re sure you really need to,
because it’s usually a lot slower than using Python lists.

   ---------- Footnotes ----------

   (1) https://numpy.org/


File: python.info,  Node: How do I create a multidimensional list?,  Next: How do I apply a method or function to a sequence of objects?,  Prev: How do you make an array in Python?,  Up: Sequences Tuples/Lists

10.2.5.7 How do I create a multidimensional list?
.................................................

You probably tried to make a multidimensional array like this:

     >>> A = [[None] * 2] * 3

This looks correct if you print it:

     >>> A
     [[None, None], [None, None], [None, None]]

But when you assign a value, it shows up in multiple places:

     >>> A[0][0] = 5
     >>> A
     [[5, None], [5, None], [5, None]]

The reason is that replicating a list with ‘*’ doesn’t create copies, it
only creates references to the existing objects.  The ‘*3’ creates a
list containing 3 references to the same list of length two.  Changes to
one row will show in all rows, which is almost certainly not what you
want.

The suggested approach is to create a list of the desired length first
and then fill in each element with a newly created list:

     A = [None] * 3
     for i in range(3):
         A[i] = [None] * 2

This generates a list containing 3 different lists of length two.  You
can also use a list comprehension:

     w, h = 2, 3
     A = [[None] * w for i in range(h)]

Or, you can use an extension that provides a matrix datatype; NumPy(1)
is the best known.

   ---------- Footnotes ----------

   (1) https://numpy.org/


File: python.info,  Node: How do I apply a method or function to a sequence of objects?,  Next: Why does a_tuple[i] += [“item”] raise an exception when the addition works?,  Prev: How do I create a multidimensional list?,  Up: Sequences Tuples/Lists

10.2.5.8 How do I apply a method or function to a sequence of objects?
......................................................................

To call a method or function and accumulate the return values is a list,
a *note list comprehension: 8de. is an elegant solution:

     result = [obj.method() for obj in mylist]

     result = [function(obj) for obj in mylist]

To just run the method or function without saving the return values, a
plain *note for: 34a. loop will suffice:

     for obj in mylist:
         obj.method()

     for obj in mylist:
         function(obj)


File: python.info,  Node: Why does a_tuple[i] += [“item”] raise an exception when the addition works?,  Next: I want to do a complicated sort can you do a Schwartzian Transform in Python?,  Prev: How do I apply a method or function to a sequence of objects?,  Up: Sequences Tuples/Lists

10.2.5.9 Why does a_tuple[i] += [“item”] raise an exception when the addition works?
....................................................................................

This is because of a combination of the fact that augmented assignment
operators are 'assignment' operators, and the difference between mutable
and immutable objects in Python.

This discussion applies in general when augmented assignment operators
are applied to elements of a tuple that point to mutable objects, but
we’ll use a ‘list’ and ‘+=’ as our exemplar.

If you wrote:

     >>> a_tuple = (1, 2)
     >>> a_tuple[0] += 1
     Traceback (most recent call last):
        ...
     TypeError: 'tuple' object does not support item assignment

The reason for the exception should be immediately clear: ‘1’ is added
to the object ‘a_tuple[0]’ points to (‘1’), producing the result object,
‘2’, but when we attempt to assign the result of the computation, ‘2’,
to element ‘0’ of the tuple, we get an error because we can’t change
what an element of a tuple points to.

Under the covers, what this augmented assignment statement is doing is
approximately this:

     >>> result = a_tuple[0] + 1
     >>> a_tuple[0] = result
     Traceback (most recent call last):
       ...
     TypeError: 'tuple' object does not support item assignment

It is the assignment part of the operation that produces the error,
since a tuple is immutable.

When you write something like:

     >>> a_tuple = (['foo'], 'bar')
     >>> a_tuple[0] += ['item']
     Traceback (most recent call last):
       ...
     TypeError: 'tuple' object does not support item assignment

The exception is a bit more surprising, and even more surprising is the
fact that even though there was an error, the append worked:

     >>> a_tuple[0]
     ['foo', 'item']

To see why this happens, you need to know that (a) if an object
implements an *note __iadd__(): 23c5. magic method, it gets called when
the ‘+=’ augmented assignment is executed, and its return value is what
gets used in the assignment statement; and (b) for lists, ‘__iadd__()’
is equivalent to calling *note extend(): 23bf. on the list and returning
the list.  That’s why we say that for lists, ‘+=’ is a «shorthand» for
*note list.extend(): 602.:

     >>> a_list = []
     >>> a_list += [1]
     >>> a_list
     [1]

This is equivalent to:

     >>> result = a_list.__iadd__([1])
     >>> a_list = result

The object pointed to by a_list has been mutated, and the pointer to the
mutated object is assigned back to ‘a_list’.  The end result of the
assignment is a no-op, since it is a pointer to the same object that
‘a_list’ was previously pointing to, but the assignment still happens.

Thus, in our tuple example what is happening is equivalent to:

     >>> result = a_tuple[0].__iadd__(['item'])
     >>> a_tuple[0] = result
     Traceback (most recent call last):
       ...
     TypeError: 'tuple' object does not support item assignment

The ‘__iadd__()’ succeeds, and thus the list is extended, but even
though ‘result’ points to the same object that ‘a_tuple[0]’ already
points to, that final assignment still results in an error, because
tuples are immutable.


File: python.info,  Node: I want to do a complicated sort can you do a Schwartzian Transform in Python?,  Next: How can I sort one list by values from another list?,  Prev: Why does a_tuple[i] += [“item”] raise an exception when the addition works?,  Up: Sequences Tuples/Lists

10.2.5.10 I want to do a complicated sort: can you do a Schwartzian Transform in Python?
........................................................................................

The technique, attributed to Randal Schwartz of the Perl community,
sorts the elements of a list by a metric which maps each element to its
«sort value».  In Python, use the ‘key’ argument for the *note
list.sort(): dca. method:

     Isorted = L[:]
     Isorted.sort(key=lambda s: int(s[10:15]))


File: python.info,  Node: How can I sort one list by values from another list?,  Prev: I want to do a complicated sort can you do a Schwartzian Transform in Python?,  Up: Sequences Tuples/Lists

10.2.5.11 How can I sort one list by values from another list?
..............................................................

Merge them into an iterator of tuples, sort the resulting list, and then
pick out the element you want.

     >>> list1 = ["what", "I'm", "sorting", "by"]
     >>> list2 = ["something", "else", "to", "sort"]
     >>> pairs = zip(list1, list2)
     >>> pairs = sorted(pairs)
     >>> pairs
     [("I'm", 'else'), ('by', 'sort'), ('sorting', 'to'), ('what', 'something')]
     >>> result = [x[1] for x in pairs]
     >>> result
     ['else', 'sort', 'to', 'something']


File: python.info,  Node: Objects,  Next: Modules<3>,  Prev: Sequences Tuples/Lists,  Up: Programming FAQ

10.2.6 Objects
--------------

* Menu:

* What is a class?::
* What is a method?::
* What is self?::
* How do I check if an object is an instance of a given class or of a subclass of it?::
* What is delegation?::
* How do I call a method defined in a base class from a derived class that extends it?::
* How can I organize my code to make it easier to change the base class?::
* How do I create static class data and static class methods?::
* How can I overload constructors (or methods) in Python?: How can I overload constructors or methods in Python?.
* I try to use __spam and I get an error about _SomeClassName__spam.: I try to use __spam and I get an error about _SomeClassName__spam.
* My class defines __del__ but it is not called when I delete the object.: My class defines __del__ but it is not called when I delete the object.
* How do I get a list of all instances of a given class?::
* Why does the result of id() appear to be not unique?: Why does the result of id appear to be not unique?.
* When can I rely on identity tests with the is operator?::
* How can a subclass control what data is stored in an immutable instance?::
* How do I cache method calls?::


File: python.info,  Node: What is a class?,  Next: What is a method?,  Up: Objects

10.2.6.1 What is a class?
.........................

A class is the particular object type created by executing a class
statement.  Class objects are used as templates to create instance
objects, which embody both the data (attributes) and code (methods)
specific to a datatype.

A class can be based on one or more other classes, called its base
class(es).  It then inherits the attributes and methods of its base
classes.  This allows an object model to be successively refined by
inheritance.  You might have a generic ‘Mailbox’ class that provides
basic accessor methods for a mailbox, and subclasses such as
‘MboxMailbox’, ‘MaildirMailbox’, ‘OutlookMailbox’ that handle various
specific mailbox formats.


File: python.info,  Node: What is a method?,  Next: What is self?,  Prev: What is a class?,  Up: Objects

10.2.6.2 What is a method?
..........................

A method is a function on some object ‘x’ that you normally call as
‘x.name(arguments...)’.  Methods are defined as functions inside the
class definition:

     class C:
         def meth(self, arg):
             return arg * 2 + self.attribute


File: python.info,  Node: What is self?,  Next: How do I check if an object is an instance of a given class or of a subclass of it?,  Prev: What is a method?,  Up: Objects

10.2.6.3 What is self?
......................

Self is merely a conventional name for the first argument of a method.
A method defined as ‘meth(self, a, b, c)’ should be called as ‘x.meth(a,
b, c)’ for some instance ‘x’ of the class in which the definition
occurs; the called method will think it is called as ‘meth(x, a, b, c)’.

See also *note Why must “self” be used explicitly in method definitions
and calls?: 58c4.


File: python.info,  Node: How do I check if an object is an instance of a given class or of a subclass of it?,  Next: What is delegation?,  Prev: What is self?,  Up: Objects

10.2.6.4 How do I check if an object is an instance of a given class or of a subclass of it?
............................................................................................

Use the built-in function *note isinstance(obj, cls): 2ad.  You can
check if an object is an instance of any of a number of classes by
providing a tuple instead of a single class, e.g.  ‘isinstance(obj,
(class1, class2, ...))’, and can also check whether an object is one of
Python’s built-in types, e.g.  ‘isinstance(obj, str)’ or
‘isinstance(obj, (int, float, complex))’.

Note that *note isinstance(): 2ad. also checks for virtual inheritance
from an *note abstract base class: 13be.  So, the test will return
‘True’ for a registered class even if hasn’t directly or indirectly
inherited from it.  To test for «true inheritance», scan the *note MRO:
18c5. of the class:

     from collections.abc import Mapping

     class P:
          pass

     class C(P):
         pass

     Mapping.register(P)

     >>> c = C()
     >>> isinstance(c, C)        # direct
     True
     >>> isinstance(c, P)        # indirect
     True
     >>> isinstance(c, Mapping)  # virtual
     True

     # Actual inheritance chain
     >>> type(c).__mro__
     (<class 'C'>, <class 'P'>, <class 'object'>)

     # Test for "true inheritance"
     >>> Mapping in type(c).__mro__
     False

Note that most programs do not use *note isinstance(): 2ad. on
user-defined classes very often.  If you are developing the classes
yourself, a more proper object-oriented style is to define methods on
the classes that encapsulate a particular behaviour, instead of checking
the object’s class and doing a different thing based on what class it
is.  For example, if you have a function that does something:

     def search(obj):
         if isinstance(obj, Mailbox):
             ...  # code to search a mailbox
         elif isinstance(obj, Document):
             ...  # code to search a document
         elif ...

A better approach is to define a ‘search()’ method on all the classes
and just call it:

     class Mailbox:
         def search(self):
             ...  # code to search a mailbox

     class Document:
         def search(self):
             ...  # code to search a document

     obj.search()


File: python.info,  Node: What is delegation?,  Next: How do I call a method defined in a base class from a derived class that extends it?,  Prev: How do I check if an object is an instance of a given class or of a subclass of it?,  Up: Objects

10.2.6.5 What is delegation?
............................

Delegation is an object oriented technique (also called a design
pattern).  Let’s say you have an object ‘x’ and want to change the
behaviour of just one of its methods.  You can create a new class that
provides a new implementation of the method you’re interested in
changing and delegates all other methods to the corresponding method of
‘x’.

Python programmers can easily implement delegation.  For example, the
following class implements a class that behaves like a file but converts
all written data to uppercase:

     class UpperOut:

         def __init__(self, outfile):
             self._outfile = outfile

         def write(self, s):
             self._outfile.write(s.upper())

         def __getattr__(self, name):
             return getattr(self._outfile, name)

Here the ‘UpperOut’ class redefines the ‘write()’ method to convert the
argument string to uppercase before calling the underlying
‘self._outfile.write()’ method.  All other methods are delegated to the
underlying ‘self._outfile’ object.  The delegation is accomplished via
the *note __getattr__(): 6fb. method; consult *note the language
reference: 2395. for more information about controlling attribute
access.

Note that for more general cases delegation can get trickier.  When
attributes must be set as well as retrieved, the class must define a
*note __setattr__(): 2362. method too, and it must do so carefully.  The
basic implementation of ‘__setattr__()’ is roughly equivalent to the
following:

     class X:
         ...
         def __setattr__(self, name, value):
             self.__dict__[name] = value
         ...

Many *note __setattr__(): 2362. implementations call
‘object.__setattr__()’ to set an attribute on self without causing
infinite recursion:

     class X:
         def __setattr__(self, name, value):
             # Custom logic here...
             object.__setattr__(self, name, value)

Alternatively, it is possible to set attributes by inserting entries
into *note self.__dict__: 77e. directly.


File: python.info,  Node: How do I call a method defined in a base class from a derived class that extends it?,  Next: How can I organize my code to make it easier to change the base class?,  Prev: What is delegation?,  Up: Objects

10.2.6.6 How do I call a method defined in a base class from a derived class that extends it?
.............................................................................................

Use the built-in *note super(): 1a6. function:

     class Derived(Base):
         def meth(self):
             super().meth()  # calls Base.meth

In the example, *note super(): 1a6. will automatically determine the
instance from which it was called (the ‘self’ value), look up the *note
method resolution order: 25bd. (MRO) with ‘type(self).__mro__’, and
return the next in line after ‘Derived’ in the MRO: ‘Base’.


File: python.info,  Node: How can I organize my code to make it easier to change the base class?,  Next: How do I create static class data and static class methods?,  Prev: How do I call a method defined in a base class from a derived class that extends it?,  Up: Objects

10.2.6.7 How can I organize my code to make it easier to change the base class?
...............................................................................

You could assign the base class to an alias and derive from the alias.
Then all you have to change is the value assigned to the alias.
Incidentally, this trick is also handy if you want to decide dynamically
(e.g.  depending on availability of resources) which base class to use.
Example:

     class Base:
         ...

     BaseAlias = Base

     class Derived(BaseAlias):
         ...


File: python.info,  Node: How do I create static class data and static class methods?,  Next: How can I overload constructors or methods in Python?,  Prev: How can I organize my code to make it easier to change the base class?,  Up: Objects

10.2.6.8 How do I create static class data and static class methods?
....................................................................

Both static data and static methods (in the sense of C++ or Java) are
supported in Python.

For static data, simply define a class attribute.  To assign a new value
to the attribute, you have to explicitly use the class name in the
assignment:

     class C:
         count = 0   # number of times C.__init__ called

         def __init__(self):
             C.count = C.count + 1

         def getcount(self):
             return C.count  # or return self.count

‘c.count’ also refers to ‘C.count’ for any ‘c’ such that ‘isinstance(c,
C)’ holds, unless overridden by ‘c’ itself or by some class on the
base-class search path from ‘c.__class__’ back to ‘C’.

Caution: within a method of C, an assignment like ‘self.count = 42’
creates a new and unrelated instance named «count» in ‘self’’s own dict.
Rebinding of a class-static data name must always specify the class
whether inside a method or not:

     C.count = 314

Static methods are possible:

     class C:
         @staticmethod
         def static(arg1, arg2, arg3):
             # No 'self' parameter!
             ...

However, a far more straightforward way to get the effect of a static
method is via a simple module-level function:

     def getcount():
         return C.count

If your code is structured so as to define one class (or tightly related
class hierarchy) per module, this supplies the desired encapsulation.


File: python.info,  Node: How can I overload constructors or methods in Python?,  Next: I try to use __spam and I get an error about _SomeClassName__spam,  Prev: How do I create static class data and static class methods?,  Up: Objects

10.2.6.9 How can I overload constructors (or methods) in Python?
................................................................

This answer actually applies to all methods, but the question usually
comes up first in the context of constructors.

In C++ you’d write

     class C {
         C() { cout << "No arguments\n"; }
         C(int i) { cout << "Argument is " << i << "\n"; }
     }

In Python you have to write a single constructor that catches all cases
using default arguments.  For example:

     class C:
         def __init__(self, i=None):
             if i is None:
                 print("No arguments")
             else:
                 print("Argument is", i)

This is not entirely equivalent, but close enough in practice.

You could also try a variable-length argument list, e.g.

     def __init__(self, *args):
         ...

The same approach works for all method definitions.


File: python.info,  Node: I try to use __spam and I get an error about _SomeClassName__spam,  Next: My class defines __del__ but it is not called when I delete the object,  Prev: How can I overload constructors or methods in Python?,  Up: Objects

10.2.6.10 I try to use __spam and I get an error about _SomeClassName__spam.
............................................................................

Variable names with double leading underscores are «mangled» to provide
a simple but effective way to define class private variables.  Any
identifier of the form ‘__spam’ (at least two leading underscores, at
most one trailing underscore) is textually replaced with
‘_classname__spam’, where ‘classname’ is the current class name with any
leading underscores stripped.

The identifier can be used unchanged within the class, but to access it
outside the class, the mangled name must be used:

     class A:
         def __one(self):
             return 1
         def two(self):
             return 2 * self.__one()

     class B(A):
         def three(self):
             return 3 * self._A__one()

     four = 4 * A()._A__one()

In particular, this does not guarantee privacy since an outside user can
still deliberately access the private attribute; many Python programmers
never bother to use private variable names at all.

Vedi anche
..........

The *note private name mangling specifications: 208d. for details and
special cases.


File: python.info,  Node: My class defines __del__ but it is not called when I delete the object,  Next: How do I get a list of all instances of a given class?,  Prev: I try to use __spam and I get an error about _SomeClassName__spam,  Up: Objects

10.2.6.11 My class defines __del__ but it is not called when I delete the object.
.................................................................................

There are several possible reasons for this.

The *note del: 1b07. statement does not necessarily call *note
__del__(): 11ff. – it simply decrements the object’s reference count,
and if this reaches zero ‘__del__()’ is called.

If your data structures contain circular links (e.g.  a tree where each
child has a parent reference and each parent has a list of children) the
reference counts will never go back to zero.  Once in a while Python
runs an algorithm to detect such cycles, but the garbage collector might
run some time after the last reference to your data structure vanishes,
so your ‘__del__()’ method may be called at an inconvenient and random
time.  This is inconvenient if you’re trying to reproduce a problem.
Worse, the order in which object’s ‘__del__()’ methods are executed is
arbitrary.  You can run *note gc.collect(): 1b3. to force a collection,
but there 'are' pathological cases where objects will never be
collected.

Despite the cycle collector, it’s still a good idea to define an
explicit ‘close()’ method on objects to be called whenever you’re done
with them.  The ‘close()’ method can then remove attributes that refer
to subobjects.  Don’t call ‘__del__()’ directly – ‘__del__()’ should
call ‘close()’ and ‘close()’ should make sure that it can be called more
than once for the same object.

Another way to avoid cyclical references is to use the *note weakref:
11a. module, which allows you to point to objects without incrementing
their reference count.  Tree data structures, for instance, should use
weak references for their parent and sibling references (if they need
them!).

Finally, if your ‘__del__()’ method raises an exception, a warning
message is printed to *note sys.stderr: b35.


File: python.info,  Node: How do I get a list of all instances of a given class?,  Next: Why does the result of id appear to be not unique?,  Prev: My class defines __del__ but it is not called when I delete the object,  Up: Objects

10.2.6.12 How do I get a list of all instances of a given class?
................................................................

Python does not keep track of all instances of a class (or of a built-in
type).  You can program the class’s constructor to keep track of all
instances by keeping a list of weak references to each instance.


File: python.info,  Node: Why does the result of id appear to be not unique?,  Next: When can I rely on identity tests with the is operator?,  Prev: How do I get a list of all instances of a given class?,  Up: Objects

10.2.6.13 Why does the result of ‘id()’ appear to be not unique?
................................................................

The *note id(): 162a. builtin returns an integer that is guaranteed to
be unique during the lifetime of the object.  Since in CPython, this is
the object’s memory address, it happens frequently that after an object
is deleted from memory, the next freshly created object is allocated at
the same position in memory.  This is illustrated by this example:

     >>> id(1000)
     13901272
     >>> id(2000)
     13901272

The two ids belong to different integer objects that are created before,
and deleted immediately after execution of the ‘id()’ call.  To be sure
that objects whose id you want to examine are still alive, create
another reference to the object:

     >>> a = 1000; b = 2000
     >>> id(a)
     13901272
     >>> id(b)
     13891296


File: python.info,  Node: When can I rely on identity tests with the is operator?,  Next: How can a subclass control what data is stored in an immutable instance?,  Prev: Why does the result of id appear to be not unique?,  Up: Objects

10.2.6.14 When can I rely on identity tests with the 'is' operator?
...................................................................

The ‘is’ operator tests for object identity.  The test ‘a is b’ is
equivalent to ‘id(a) == id(b)’.

The most important property of an identity test is that an object is
always identical to itself, ‘a is a’ always returns ‘True’.  Identity
tests are usually faster than equality tests.  And unlike equality
tests, identity tests are guaranteed to return a boolean ‘True’ or
‘False’.

However, identity tests can 'only' be substituted for equality tests
when object identity is assured.  Generally, there are three
circumstances where identity is guaranteed:

  1. Assignments create new names but do not change object identity.
     After the assignment ‘new = old’, it is guaranteed that ‘new is
     old’.

  2. Putting an object in a container that stores object references does
     not change object identity.  After the list assignment ‘s[0] = x’,
     it is guaranteed that ‘s[0] is x’.

  3. If an object is a singleton, it means that only one instance of
     that object can exist.  After the assignments ‘a = None’ and ‘b =
     None’, it is guaranteed that ‘a is b’ because ‘None’ is a
     singleton.

In most other circumstances, identity tests are inadvisable and equality
tests are preferred.  In particular, identity tests should not be used
to check constants such as *note int: 19b. and *note str: 169. which
aren’t guaranteed to be singletons:

     >>> a = 1000
     >>> b = 500
     >>> c = b + 500
     >>> a is c
     False

     >>> a = 'Python'
     >>> b = 'Py'
     >>> c = b + 'thon'
     >>> a is c
     False

Likewise, new instances of mutable containers are never identical:

     >>> a = []
     >>> b = []
     >>> a is b
     False

In the standard library code, you will see several common patterns for
correctly using identity tests:

  1. As recommended by PEP 8(1), an identity test is the preferred way
     to check for ‘None’.  This reads like plain English in code and
     avoids confusion with other objects that may have boolean values
     that evaluate to false.

  2. Detecting optional arguments can be tricky when ‘None’ is a valid
     input value.  In those situations, you can create a singleton
     sentinel object guaranteed to be distinct from other objects.  For
     example, here is how to implement a method that behaves like *note
     dict.pop(): 5e6.:

          _sentinel = object()

          def pop(self, key, default=_sentinel):
              if key in self:
                  value = self[key]
                  del self[key]
                  return value
              if default is _sentinel:
                  raise KeyError(key)
              return default

  3. Container implementations sometimes need to augment equality tests
     with identity tests.  This prevents the code from being confused by
     objects such as ‘float('NaN')’ that are not equal to themselves.

For example, here is the implementation of
‘collections.abc.Sequence.__contains__()’:

     def __contains__(self, value):
         for v in self:
             if v is value or v == value:
                 return True
         return False

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0008/


File: python.info,  Node: How can a subclass control what data is stored in an immutable instance?,  Next: How do I cache method calls?,  Prev: When can I rely on identity tests with the is operator?,  Up: Objects

10.2.6.15 How can a subclass control what data is stored in an immutable instance?
..................................................................................

When subclassing an immutable type, override the *note __new__(): 7a1.
method instead of the *note __init__(): 8c0. method.  The latter only
runs 'after' an instance is created, which is too late to alter data in
an immutable instance.

All of these immutable classes have a different signature than their
parent class:

     from datetime import date

     class FirstOfMonthDate(date):
         "Always choose the first day of the month"
         def __new__(cls, year, month, day):
             return super().__new__(cls, year, month, 1)

     class NamedInt(int):
         "Allow text names for some numbers"
         xlat = {'zero': 0, 'one': 1, 'ten': 10}
         def __new__(cls, value):
             value = cls.xlat.get(value, value)
             return super().__new__(cls, value)

     class TitleStr(str):
         "Convert str to name suitable for a URL path"
         def __new__(cls, s):
             s = s.lower().replace(' ', '-')
             s = ''.join([c for c in s if c.isalnum() or c == '-'])
             return super().__new__(cls, s)

The classes can be used like this:

     >>> FirstOfMonthDate(2012, 2, 14)
     FirstOfMonthDate(2012, 2, 1)
     >>> NamedInt('ten')
     10
     >>> NamedInt(20)
     20
     >>> TitleStr('Blog: Why Python Rocks')
     'blog-why-python-rocks'


File: python.info,  Node: How do I cache method calls?,  Prev: How can a subclass control what data is stored in an immutable instance?,  Up: Objects

10.2.6.16 How do I cache method calls?
......................................

The two principal tools for caching methods are *note
functools.cached_property(): 764. and *note functools.lru_cache(): be4.
The former stores results at the instance level and the latter at the
class level.

The 'cached_property' approach only works with methods that do not take
any arguments.  It does not create a reference to the instance.  The
cached method result will be kept only as long as the instance is alive.

The advantage is that when an instance is no longer used, the cached
method result will be released right away.  The disadvantage is that if
instances accumulate, so too will the accumulated method results.  They
can grow without bound.

The 'lru_cache' approach works with methods that have *note hashable:
825. arguments.  It creates a reference to the instance unless special
efforts are made to pass in weak references.

The advantage of the least recently used algorithm is that the cache is
bounded by the specified 'maxsize'.  The disadvantage is that instances
are kept alive until they age out of the cache or until the cache is
cleared.

This example shows the various techniques:

     class Weather:
         "Lookup weather information on a government website"

         def __init__(self, station_id):
             self._station_id = station_id
             # The _station_id is private and immutable

         def current_temperature(self):
             "Latest hourly observation"
             # Do not cache this because old results
             # can be out of date.

         @cached_property
         def location(self):
             "Return the longitude/latitude coordinates of the station"
             # Result only depends on the station_id

         @lru_cache(maxsize=20)
         def historic_rainfall(self, date, units='mm'):
             "Rainfall on a given date"
             # Depends on the station_id, date, and units.

The above example assumes that the 'station_id' never changes.  If the
relevant instance attributes are mutable, the 'cached_property' approach
can’t be made to work because it cannot detect changes to the
attributes.

To make the 'lru_cache' approach work when the 'station_id' is mutable,
the class needs to define the *note __eq__(): cf4. and *note __hash__():
cf5. methods so that the cache can detect relevant attribute updates:

     class Weather:
         "Example with a mutable station identifier"

         def __init__(self, station_id):
             self.station_id = station_id

         def change_station(self, station_id):
             self.station_id = station_id

         def __eq__(self, other):
             return self.station_id == other.station_id

         def __hash__(self):
             return hash(self.station_id)

         @lru_cache(maxsize=20)
         def historic_rainfall(self, date, units='cm'):
             'Rainfall on a given date'
             # Depends on the station_id, date, and units.


File: python.info,  Node: Modules<3>,  Prev: Objects,  Up: Programming FAQ

10.2.7 Modules
--------------

* Menu:

* How do I create a .pyc file?: How do I create a pyc file?.
* How do I find the current module name?::
* How can I have modules that mutually import each other?::
* __import__(“x.y.z”) returns <module “x”>; how do I get z?: __import__ “x y z” returns <module “x”>; how do I get z?.
* When I edit an imported module and reimport it, the changes don’t show up. Why does this happen?: When I edit an imported module and reimport it the changes don’t show up Why does this happen?.


File: python.info,  Node: How do I create a pyc file?,  Next: How do I find the current module name?,  Up: Modules<3>

10.2.7.1 How do I create a .pyc file?
.....................................

When a module is imported for the first time (or when the source file
has changed since the current compiled file was created) a ‘.pyc’ file
containing the compiled code should be created in a ‘__pycache__’
subdirectory of the directory containing the ‘.py’ file.  The ‘.pyc’
file will have a filename that starts with the same name as the ‘.py’
file, and ends with ‘.pyc’, with a middle component that depends on the
particular ‘python’ binary that created it.  (See PEP 3147(1) for
details.)

One reason that a ‘.pyc’ file may not be created is a permissions
problem with the directory containing the source file, meaning that the
‘__pycache__’ subdirectory cannot be created.  This can happen, for
example, if you develop as one user but run as another, such as if you
are testing with a web server.

Unless the *note PYTHONDONTWRITEBYTECODE: 15d5. environment variable is
set, creation of a .pyc file is automatic if you’re importing a module
and Python has the ability (permissions, free space, etc…) to create a
‘__pycache__’ subdirectory and write the compiled module to that
subdirectory.

Running Python on a top level script is not considered an import and no
‘.pyc’ will be created.  For example, if you have a top-level module
‘foo.py’ that imports another module ‘xyz.py’, when you run ‘foo’ (by
typing ‘python foo.py’ as a shell command), a ‘.pyc’ will be created for
‘xyz’ because ‘xyz’ is imported, but no ‘.pyc’ file will be created for
‘foo’ since ‘foo.py’ isn’t being imported.

If you need to create a ‘.pyc’ file for ‘foo’ – that is, to create a
‘.pyc’ file for a module that is not imported – you can, using the *note
py_compile: b8. and *note compileall: 21. modules.

The *note py_compile: b8. module can manually compile any module.  One
way is to use the ‘compile()’ function in that module interactively:

     >>> import py_compile
     >>> py_compile.compile('foo.py')

This will write the ‘.pyc’ to a ‘__pycache__’ subdirectory in the same
location as ‘foo.py’ (or you can override that with the optional
parameter ‘cfile’).

You can also automatically compile all files in a directory or
directories using the *note compileall: 21. module.  You can do it from
the shell prompt by running ‘compileall.py’ and providing the path of a
directory containing Python files to compile:

     python -m compileall .

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-3147/


File: python.info,  Node: How do I find the current module name?,  Next: How can I have modules that mutually import each other?,  Prev: How do I create a pyc file?,  Up: Modules<3>

10.2.7.2 How do I find the current module name?
...............................................

A module can find out its own module name by looking at the predefined
global variable ‘__name__’.  If this has the value ‘'__main__'’, the
program is running as a script.  Many modules that are usually used by
importing them also provide a command-line interface or a self-test, and
only execute this code after checking ‘__name__’:

     def main():
         print('Running test...')
         ...

     if __name__ == '__main__':
         main()


File: python.info,  Node: How can I have modules that mutually import each other?,  Next: __import__ “x y z” returns <module “x”>; how do I get z?,  Prev: How do I find the current module name?,  Up: Modules<3>

10.2.7.3 How can I have modules that mutually import each other?
................................................................

Suppose you have the following modules:

‘foo.py’:

     from bar import bar_var
     foo_var = 1

‘bar.py’:

     from foo import foo_var
     bar_var = 2

The problem is that the interpreter will perform the following steps:

   * main imports ‘foo’

   * Empty globals for ‘foo’ are created

   * ‘foo’ is compiled and starts executing

   * ‘foo’ imports ‘bar’

   * Empty globals for ‘bar’ are created

   * ‘bar’ is compiled and starts executing

   * ‘bar’ imports ‘foo’ (which is a no-op since there already is a
     module named ‘foo’)

   * The import mechanism tries to read ‘foo_var’ from ‘foo’ globals, to
     set ‘bar.foo_var = foo.foo_var’

The last step fails, because Python isn’t done with interpreting ‘foo’
yet and the global symbol dictionary for ‘foo’ is still empty.

The same thing happens when you use ‘import foo’, and then try to access
‘foo.foo_var’ in global code.

There are (at least) three possible workarounds for this problem.

Guido van Rossum recommends avoiding all uses of ‘from <module> import
...’, and placing all code inside functions.  Initializations of global
variables and class variables should use constants or built-in functions
only.  This means everything from an imported module is referenced as
‘<module>.<name>’.

Jim Roskind suggests performing steps in the following order in each
module:

   * exports (globals, functions, and classes that don’t need imported
     base classes)

   * ‘import’ statements

   * active code (including globals that are initialized from imported
     values).

Van Rossum doesn’t like this approach much because the imports appear in
a strange place, but it does work.

Matthias Urlichs recommends restructuring your code so that the
recursive import is not necessary in the first place.

These solutions are not mutually exclusive.


File: python.info,  Node: __import__ “x y z” returns <module “x”>; how do I get z?,  Next: When I edit an imported module and reimport it the changes don’t show up Why does this happen?,  Prev: How can I have modules that mutually import each other?,  Up: Modules<3>

10.2.7.4 __import__(“x.y.z”) returns <module “x”>; how do I get z?
..................................................................

Consider using the convenience function *note import_module(): 73d. from
*note importlib: 7b. instead:

     z = importlib.import_module('x.y.z')


File: python.info,  Node: When I edit an imported module and reimport it the changes don’t show up Why does this happen?,  Prev: __import__ “x y z” returns <module “x”>; how do I get z?,  Up: Modules<3>

10.2.7.5 When I edit an imported module and reimport it, the changes don’t show up. Why does this happen?
.........................................................................................................

For reasons of efficiency as well as consistency, Python only reads the
module file on the first time a module is imported.  If it didn’t, in a
program consisting of many modules where each one imports the same basic
module, the basic module would be parsed and re-parsed many times.  To
force re-reading of a changed module, do this:

     import importlib
     import modname
     importlib.reload(modname)

Warning: this technique is not 100% fool-proof.  In particular, modules
containing statements like

     from modname import some_objects

will continue to work with the old version of the imported objects.  If
the module contains class definitions, existing class instances will
'not' be updated to use the new class definition.  This can result in
the following paradoxical behaviour:

     >>> import importlib
     >>> import cls
     >>> c = cls.C()                # Create an instance of C
     >>> importlib.reload(cls)
     <module 'cls' from 'cls.py'>
     >>> isinstance(c, cls.C)       # isinstance is false?!?
     False

The nature of the problem is made clear if you print out the «identity»
of the class objects:

     >>> hex(id(c.__class__))
     '0x7352a0'
     >>> hex(id(cls.C))
     '0x4198d0'


File: python.info,  Node: Design and History FAQ,  Next: Library and Extension FAQ,  Prev: Programming FAQ,  Up: Python Frequently Asked Questions

10.3 Design and History FAQ
===========================

* Menu:

* Why does Python use indentation for grouping of statements?::
* Why am I getting strange results with simple arithmetic operations?::
* Why are floating-point calculations so inaccurate?::
* Why are Python strings immutable?::
* Why must “self” be used explicitly in method definitions and calls?::
* Why can’t I use an assignment in an expression?::
* Why does Python use methods for some functionality (e.g. list.index()) but functions for other (e.g. len(list))?: Why does Python use methods for some functionality e g list index but functions for other e g len list ?.
* Why is join() a string method instead of a list or tuple method?: Why is join a string method instead of a list or tuple method?.
* How fast are exceptions?::
* Why isn’t there a switch or case statement in Python?::
* Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?::
* Why can’t lambda expressions contain statements?::
* Can Python be compiled to machine code, C or some other language?: Can Python be compiled to machine code C or some other language?.
* How does Python manage memory?::
* Why doesn’t CPython use a more traditional garbage collection scheme?::
* Why isn’t all memory freed when CPython exits?::
* Why are there separate tuple and list data types?::
* How are lists implemented in CPython?::
* How are dictionaries implemented in CPython?::
* Why must dictionary keys be immutable?::
* Why doesn’t list.sort() return the sorted list?: Why doesn’t list sort return the sorted list?.
* How do you specify and enforce an interface spec in Python?::
* Why is there no goto?::
* Why can’t raw strings (r-strings) end with a backslash?: Why can’t raw strings r-strings end with a backslash?.
* Why doesn’t Python have a «with» statement for attribute assignments?::
* Why don’t generators support the with statement?::
* Why are colons required for the if/while/def/class statements?::
* Why does Python allow commas at the end of lists and tuples?::


File: python.info,  Node: Why does Python use indentation for grouping of statements?,  Next: Why am I getting strange results with simple arithmetic operations?,  Up: Design and History FAQ

10.3.1 Why does Python use indentation for grouping of statements?
------------------------------------------------------------------

Guido van Rossum believes that using indentation for grouping is
extremely elegant and contributes a lot to the clarity of the average
Python program.  Most people learn to love this feature after a while.

Since there are no begin/end brackets there cannot be a disagreement
between grouping perceived by the parser and the human reader.
Occasionally C programmers will encounter a fragment of code like this:

     if (x <= y)
             x++;
             y--;
     z++;

Only the ‘x++’ statement is executed if the condition is true, but the
indentation leads many to believe otherwise.  Even experienced C
programmers will sometimes stare at it a long time wondering as to why
‘y’ is being decremented even for ‘x > y’.

Because there are no begin/end brackets, Python is much less prone to
coding-style conflicts.  In C there are many different ways to place the
braces.  After becoming used to reading and writing code using a
particular style, it is normal to feel somewhat uneasy when reading (or
being required to write) in a different one.

Many coding styles place begin/end brackets on a line by themselves.
This makes programs considerably longer and wastes valuable screen
space, making it harder to get a good overview of a program.  Ideally, a
function should fit on one screen (say, 20–30 lines).  20 lines of
Python can do a lot more work than 20 lines of C. This is not solely due
to the lack of begin/end brackets – the lack of declarations and the
high-level data types are also responsible – but the indentation-based
syntax certainly helps.


File: python.info,  Node: Why am I getting strange results with simple arithmetic operations?,  Next: Why are floating-point calculations so inaccurate?,  Prev: Why does Python use indentation for grouping of statements?,  Up: Design and History FAQ

10.3.2 Why am I getting strange results with simple arithmetic operations?
--------------------------------------------------------------------------

See the next question.


File: python.info,  Node: Why are floating-point calculations so inaccurate?,  Next: Why are Python strings immutable?,  Prev: Why am I getting strange results with simple arithmetic operations?,  Up: Design and History FAQ

10.3.3 Why are floating-point calculations so inaccurate?
---------------------------------------------------------

Users are often surprised by results like this:

     >>> 1.2 - 1.0
     0.19999999999999996

and think it is a bug in Python.  It’s not.  This has little to do with
Python, and much more to do with how the underlying platform handles
floating-point numbers.

The *note float: 196. type in CPython uses a C ‘double’ for storage.  A
*note float: 196. object’s value is stored in binary floating-point with
a fixed precision (typically 53 bits) and Python uses C operations,
which in turn rely on the hardware implementation in the processor, to
perform floating-point operations.  This means that as far as
floating-point operations are concerned, Python behaves like many
popular languages including C and Java.

Many numbers that can be written easily in decimal notation cannot be
expressed exactly in binary floating point.  For example, after:

     >>> x = 1.2

the value stored for ‘x’ is a (very good) approximation to the decimal
value ‘1.2’, but is not exactly equal to it.  On a typical machine, the
actual stored value is:

     1.0011001100110011001100110011001100110011001100110011 (binary)

which is exactly:

     1.1999999999999999555910790149937383830547332763671875 (decimal)

The typical precision of 53 bits provides Python floats with 15–16
decimal digits of accuracy.

For a fuller explanation, please see the *note floating-point
arithmetic: 20ea. chapter in the Python tutorial.


File: python.info,  Node: Why are Python strings immutable?,  Next: Why must “self” be used explicitly in method definitions and calls?,  Prev: Why are floating-point calculations so inaccurate?,  Up: Design and History FAQ

10.3.4 Why are Python strings immutable?
----------------------------------------

There are several advantages.

One is performance: knowing that a string is immutable means we can
allocate space for it at creation time, and the storage requirements are
fixed and unchanging.  This is also one of the reasons for the
distinction between tuples and lists.

Another advantage is that strings in Python are considered as
«elemental» as numbers.  No amount of activity will change the value 8
to anything else, and in Python, no amount of activity will change the
string «eight» to anything else.


File: python.info,  Node: Why must “self” be used explicitly in method definitions and calls?,  Next: Why can’t I use an assignment in an expression?,  Prev: Why are Python strings immutable?,  Up: Design and History FAQ

10.3.5 Why must “self” be used explicitly in method definitions and calls?
--------------------------------------------------------------------------

The idea was borrowed from Modula-3.  It turns out to be very useful,
for a variety of reasons.

First, it’s more obvious that you are using a method or instance
attribute instead of a local variable.  Reading ‘self.x’ or
‘self.meth()’ makes it absolutely clear that an instance variable or
method is used even if you don’t know the class definition by heart.  In
C++, you can sort of tell by the lack of a local variable declaration
(assuming globals are rare or easily recognizable) – but in Python,
there are no local variable declarations, so you’d have to look up the
class definition to be sure.  Some C++ and Java coding standards call
for instance attributes to have an ‘m_’ prefix, so this explicitness is
still useful in those languages, too.

Second, it means that no special syntax is necessary if you want to
explicitly reference or call the method from a particular class.  In
C++, if you want to use a method from a base class which is overridden
in a derived class, you have to use the ‘::’ operator – in Python you
can write ‘baseclass.methodname(self, <argument list>)’.  This is
particularly useful for *note __init__(): 8c0. methods, and in general
in cases where a derived class method wants to extend the base class
method of the same name and thus has to call the base class method
somehow.

Finally, for instance variables it solves a syntactic problem with
assignment: since local variables in Python are (by definition!)  those
variables to which a value is assigned in a function body (and that
aren’t explicitly declared global), there has to be some way to tell the
interpreter that an assignment was meant to assign to an instance
variable instead of to a local variable, and it should preferably be
syntactic (for efficiency reasons).  C++ does this through declarations,
but Python doesn’t have declarations and it would be a pity having to
introduce them just for this purpose.  Using the explicit ‘self.var’
solves this nicely.  Similarly, for using instance variables, having to
write ‘self.var’ means that references to unqualified names inside a
method don’t have to search the instance’s directories.  To put it
another way, local variables and instance variables live in two
different namespaces, and you need to tell Python which namespace to
use.


File: python.info,  Node: Why can’t I use an assignment in an expression?,  Next: Why does Python use methods for some functionality e g list index but functions for other e g len list ?,  Prev: Why must “self” be used explicitly in method definitions and calls?,  Up: Design and History FAQ

10.3.6 Why can’t I use an assignment in an expression?
------------------------------------------------------

Starting in Python 3.8, you can!

Assignment expressions using the walrus operator ‘:=’ assign a variable
in an expression:

     while chunk := fp.read(200):
        print(chunk)

See PEP 572(1) for more information.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0572/


File: python.info,  Node: Why does Python use methods for some functionality e g list index but functions for other e g len list ?,  Next: Why is join a string method instead of a list or tuple method?,  Prev: Why can’t I use an assignment in an expression?,  Up: Design and History FAQ

10.3.7 Why does Python use methods for some functionality (e.g. list.index()) but functions for other (e.g. len(list))?
-----------------------------------------------------------------------------------------------------------------------

As Guido said:

     (a) For some operations, prefix notation just reads better than
     postfix – prefix (and infix!)  operations have a long tradition in
     mathematics which likes notations where the visuals help the
     mathematician thinking about a problem.  Compare the easy with
     which we rewrite a formula like x*(a+b) into x*a + x*b to the
     clumsiness of doing the same thing using a raw OO notation.

     (b) When I read code that says len(x) I 'know' that it is asking
     for the length of something.  This tells me two things: the result
     is an integer, and the argument is some kind of container.  To the
     contrary, when I read x.len(), I have to already know that x is
     some kind of container implementing an interface or inheriting from
     a class that has a standard len().  Witness the confusion we
     occasionally have when a class that is not implementing a mapping
     has a get() or keys() method, or something that isn’t a file has a
     write() method.

-- ‘https://mail.python.org/pipermail/python-3000/2006-November/004643.html’


File: python.info,  Node: Why is join a string method instead of a list or tuple method?,  Next: How fast are exceptions?,  Prev: Why does Python use methods for some functionality e g list index but functions for other e g len list ?,  Up: Design and History FAQ

10.3.8 Why is join() a string method instead of a list or tuple method?
-----------------------------------------------------------------------

Strings became much more like other standard types starting in Python
1.6, when methods were added which give the same functionality that has
always been available using the functions of the string module.  Most of
these new methods have been widely accepted, but the one which appears
to make some programmers feel uncomfortable is:

     ", ".join(['1', '2', '4', '8', '16'])

which gives the result:

     "1, 2, 4, 8, 16"

There are two common arguments against this usage.

The first runs along the lines of: «It looks really ugly using a method
of a string literal (string constant)», to which the answer is that it
might, but a string literal is just a fixed value.  If the methods are
to be allowed on names bound to strings there is no logical reason to
make them unavailable on literals.

The second objection is typically cast as: «I am really telling a
sequence to join its members together with a string constant».  Sadly,
you aren’t.  For some reason there seems to be much less difficulty with
having *note split(): 10ac. as a string method, since in that case it is
easy to see that

     "1, 2, 4, 8, 16".split(", ")

is an instruction to a string literal to return the substrings delimited
by the given separator (or, by default, arbitrary runs of white space).

*note join(): 25e8. is a string method because in using it you are
telling the separator string to iterate over a sequence of strings and
insert itself between adjacent elements.  This method can be used with
any argument which obeys the rules for sequence objects, including any
new classes you might define yourself.  Similar methods exist for bytes
and bytearray objects.


File: python.info,  Node: How fast are exceptions?,  Next: Why isn’t there a switch or case statement in Python?,  Prev: Why is join a string method instead of a list or tuple method?,  Up: Design and History FAQ

10.3.9 How fast are exceptions?
-------------------------------

A *note try: 8f9./*note except: 1ab. block is extremely efficient if no
exceptions are raised.  Actually catching an exception is expensive.  In
versions of Python prior to 2.0 it was common to use this idiom:

     try:
         value = mydict[key]
     except KeyError:
         mydict[key] = getvalue(key)
         value = mydict[key]

This only made sense when you expected the dict to have the key almost
all the time.  If that wasn’t the case, you coded it like this:

     if key in mydict:
         value = mydict[key]
     else:
         value = mydict[key] = getvalue(key)

For this specific case, you could also use ‘value = dict.setdefault(key,
getvalue(key))’, but only if the ‘getvalue()’ call is cheap enough
because it is evaluated in all cases.


File: python.info,  Node: Why isn’t there a switch or case statement in Python?,  Next: Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?,  Prev: How fast are exceptions?,  Up: Design and History FAQ

10.3.10 Why isn’t there a switch or case statement in Python?
-------------------------------------------------------------

In general, structured switch statements execute one block of code when
an expression has a particular value or set of values.  Since Python
3.10 one can easily match literal values, or constants within a
namespace, with a ‘match ... case’ statement.  An older alternative is a
sequence of ‘if... elif... elif... else’.

For cases where you need to choose from a very large number of
possibilities, you can create a dictionary mapping case values to
functions to call.  For example:

     functions = {'a': function_1,
                  'b': function_2,
                  'c': self.method_1}

     func = functions[value]
     func()

For calling methods on objects, you can simplify yet further by using
the *note getattr(): dcc. built-in to retrieve methods with a particular
name:

     class MyVisitor:
         def visit_a(self):
             ...

         def dispatch(self, value):
             method_name = 'visit_' + str(value)
             method = getattr(self, method_name)
             method()

It’s suggested that you use a prefix for the method names, such as
‘visit_’ in this example.  Without such a prefix, if values are coming
from an untrusted source, an attacker would be able to call any method
on your object.

Imitating switch with fallthrough, as with C’s switch-case-default, is
possible, much harder, and less needed.


File: python.info,  Node: Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?,  Next: Why can’t lambda expressions contain statements?,  Prev: Why isn’t there a switch or case statement in Python?,  Up: Design and History FAQ

10.3.11 Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?
----------------------------------------------------------------------------------------------------------------

Answer 1: Unfortunately, the interpreter pushes at least one C stack
frame for each Python stack frame.  Also, extensions can call back into
Python at almost random moments.  Therefore, a complete threads
implementation requires thread support for C.

Answer 2: Fortunately, there is Stackless Python(1), which has a
completely redesigned interpreter loop that avoids the C stack.

   ---------- Footnotes ----------

   (1) https://github.com/stackless-dev/stackless/wiki


File: python.info,  Node: Why can’t lambda expressions contain statements?,  Next: Can Python be compiled to machine code C or some other language?,  Prev: Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?,  Up: Design and History FAQ

10.3.12 Why can’t lambda expressions contain statements?
--------------------------------------------------------

Python lambda expressions cannot contain statements because Python’s
syntactic framework can’t handle statements nested inside expressions.
However, in Python, this is not a serious problem.  Unlike lambda forms
in other languages, where they add functionality, Python lambdas are
only a shorthand notation if you’re too lazy to define a function.

Functions are already first class objects in Python, and can be declared
in a local scope.  Therefore the only advantage of using a lambda
instead of a locally defined function is that you don’t need to invent a
name for the function – but that’s just a local variable to which the
function object (which is exactly the same type of object that a lambda
expression yields) is assigned!


File: python.info,  Node: Can Python be compiled to machine code C or some other language?,  Next: How does Python manage memory?,  Prev: Why can’t lambda expressions contain statements?,  Up: Design and History FAQ

10.3.13 Can Python be compiled to machine code, C or some other language?
-------------------------------------------------------------------------

Cython(1) compiles a modified version of Python with optional
annotations into C extensions.  Nuitka(2) is an up-and-coming compiler
of Python into C++ code, aiming to support the full Python language.

   ---------- Footnotes ----------

   (1) https://cython.org/

   (2) https://nuitka.net/


File: python.info,  Node: How does Python manage memory?,  Next: Why doesn’t CPython use a more traditional garbage collection scheme?,  Prev: Can Python be compiled to machine code C or some other language?,  Up: Design and History FAQ

10.3.14 How does Python manage memory?
--------------------------------------

The details of Python memory management depend on the implementation.
The standard implementation of Python, *note CPython: 906, uses
reference counting to detect inaccessible objects, and another mechanism
to collect reference cycles, periodically executing a cycle detection
algorithm which looks for inaccessible cycles and deletes the objects
involved.  The *note gc: 64. module provides functions to perform a
garbage collection, obtain debugging statistics, and tune the
collector’s parameters.

Other implementations (such as Jython(1) or PyPy(2)), however, can rely
on a different mechanism such as a full-blown garbage collector.  This
difference can cause some subtle porting problems if your Python code
depends on the behavior of the reference counting implementation.

In some Python implementations, the following code (which is fine in
CPython) will probably run out of file descriptors:

     for file in very_long_list_of_files:
         f = open(file)
         c = f.read(1)

Indeed, using CPython’s reference counting and destructor scheme, each
new assignment to ‘f’ closes the previous file.  With a traditional GC,
however, those file objects will only get collected (and closed) at
varying and possibly long intervals.

If you want to write code that will work with any Python implementation,
you should explicitly close the file or use the *note with: 186.
statement; this will work regardless of memory management scheme:

     for file in very_long_list_of_files:
         with open(file) as f:
             c = f.read(1)

   ---------- Footnotes ----------

   (1) https://www.jython.org

   (2) https://pypy.org


File: python.info,  Node: Why doesn’t CPython use a more traditional garbage collection scheme?,  Next: Why isn’t all memory freed when CPython exits?,  Prev: How does Python manage memory?,  Up: Design and History FAQ

10.3.15 Why doesn’t CPython use a more traditional garbage collection scheme?
-----------------------------------------------------------------------------

For one thing, this is not a C standard feature and hence it’s not
portable.  (Yes, we know about the Boehm GC library.  It has bits of
assembler code for 'most' common platforms, not for all of them, and
although it is mostly transparent, it isn’t completely transparent;
patches are required to get Python to work with it.)

Traditional GC also becomes a problem when Python is embedded into other
applications.  While in a standalone Python it’s fine to replace the
standard ‘malloc()’ and ‘free()’ with versions provided by the GC
library, an application embedding Python may want to have its 'own'
substitute for ‘malloc()’ and ‘free()’, and may not want Python’s.
Right now, CPython works with anything that implements ‘malloc()’ and
‘free()’ properly.


File: python.info,  Node: Why isn’t all memory freed when CPython exits?,  Next: Why are there separate tuple and list data types?,  Prev: Why doesn’t CPython use a more traditional garbage collection scheme?,  Up: Design and History FAQ

10.3.16 Why isn’t all memory freed when CPython exits?
------------------------------------------------------

Objects referenced from the global namespaces of Python modules are not
always deallocated when Python exits.  This may happen if there are
circular references.  There are also certain bits of memory that are
allocated by the C library that are impossible to free (e.g.  a tool
like Purify will complain about these).  Python is, however, aggressive
about cleaning up memory on exit and does try to destroy every single
object.

If you want to force Python to delete certain things on deallocation use
the *note atexit: d. module to run a function that will force those
deletions.


File: python.info,  Node: Why are there separate tuple and list data types?,  Next: How are lists implemented in CPython?,  Prev: Why isn’t all memory freed when CPython exits?,  Up: Design and History FAQ

10.3.17 Why are there separate tuple and list data types?
---------------------------------------------------------

Lists and tuples, while similar in many respects, are generally used in
fundamentally different ways.  Tuples can be thought of as being similar
to Pascal ‘records’ or C ‘structs’; they’re small collections of related
data which may be of different types which are operated on as a group.
For example, a Cartesian coordinate is appropriately represented as a
tuple of two or three numbers.

Lists, on the other hand, are more like arrays in other languages.  They
tend to hold a varying number of objects all of which have the same type
and which are operated on one-by-one.  For example, *note
os.listdir('.'): 1302. returns a list of strings representing the files
in the current directory.  Functions which operate on this output would
generally not break if you added another file or two to the directory.

Tuples are immutable, meaning that once a tuple has been created, you
can’t replace any of its elements with a new value.  Lists are mutable,
meaning that you can always change a list’s elements.  Only immutable
elements can be used as dictionary keys, and hence only tuples and not
lists can be used as keys.


File: python.info,  Node: How are lists implemented in CPython?,  Next: How are dictionaries implemented in CPython?,  Prev: Why are there separate tuple and list data types?,  Up: Design and History FAQ

10.3.18 How are lists implemented in CPython?
---------------------------------------------

CPython’s lists are really variable-length arrays, not Lisp-style linked
lists.  The implementation uses a contiguous array of references to
other objects, and keeps a pointer to this array and the array’s length
in a list head structure.

This makes indexing a list ‘a[i]’ an operation whose cost is independent
of the size of the list or the value of the index.

When items are appended or inserted, the array of references is resized.
Some cleverness is applied to improve the performance of appending items
repeatedly; when the array must be grown, some extra space is allocated
so the next few times don’t require an actual resize.


File: python.info,  Node: How are dictionaries implemented in CPython?,  Next: Why must dictionary keys be immutable?,  Prev: How are lists implemented in CPython?,  Up: Design and History FAQ

10.3.19 How are dictionaries implemented in CPython?
----------------------------------------------------

CPython’s dictionaries are implemented as resizable hash tables.
Compared to B-trees, this gives better performance for lookup (the most
common operation by far) under most circumstances, and the
implementation is simpler.

Dictionaries work by computing a hash code for each key stored in the
dictionary using the *note hash(): 802. built-in function.  The hash
code varies widely depending on the key and a per-process seed; for
example, ‘'Python'’ could hash to ‘-539294296’ while ‘'python'’, a
string that differs by a single bit, could hash to ‘1142331976’.  The
hash code is then used to calculate a location in an internal array
where the value will be stored.  Assuming that you’re storing keys that
all have different hash values, this means that dictionaries take
constant time – 'O'(1), in Big-O notation – to retrieve a key.


File: python.info,  Node: Why must dictionary keys be immutable?,  Next: Why doesn’t list sort return the sorted list?,  Prev: How are dictionaries implemented in CPython?,  Up: Design and History FAQ

10.3.20 Why must dictionary keys be immutable?
----------------------------------------------

The hash table implementation of dictionaries uses a hash value
calculated from the key value to find the key.  If the key were a
mutable object, its value could change, and thus its hash could also
change.  But since whoever changes the key object can’t tell that it was
being used as a dictionary key, it can’t move the entry around in the
dictionary.  Then, when you try to look up the same object in the
dictionary it won’t be found because its hash value is different.  If
you tried to look up the old value it wouldn’t be found either, because
the value of the object found in that hash bin would be different.

If you want a dictionary indexed with a list, simply convert the list to
a tuple first; the function ‘tuple(L)’ creates a tuple with the same
entries as the list ‘L’.  Tuples are immutable and can therefore be used
as dictionary keys.

Some unacceptable solutions that have been proposed:

   - Hash lists by their address (object ID). This doesn’t work because
     if you construct a new list with the same value it won’t be found;
     e.g.:

          mydict = {[1, 2]: '12'}
          print(mydict[[1, 2]])

     would raise a *note KeyError: 5e7. exception because the id of the
     ‘[1, 2]’ used in the second line differs from that in the first
     line.  In other words, dictionary keys should be compared using
     ‘==’, not using *note is: 34c.

   - Make a copy when using a list as a key.  This doesn’t work because
     the list, being a mutable object, could contain a reference to
     itself, and then the copying code would run into an infinite loop.

   - Allow lists as keys but tell the user not to modify them.  This
     would allow a class of hard-to-track bugs in programs when you
     forgot or modified a list by accident.  It also invalidates an
     important invariant of dictionaries: every value in ‘d.keys()’ is
     usable as a key of the dictionary.

   - Mark lists as read-only once they are used as a dictionary key.
     The problem is that it’s not just the top-level object that could
     change its value; you could use a tuple containing a list as a key.
     Entering anything as a key into a dictionary would require marking
     all objects reachable from there as read-only – and again,
     self-referential objects could cause an infinite loop.

There is a trick to get around this if you need to, but use it at your
own risk: You can wrap a mutable structure inside a class instance which
has both a *note __eq__(): cf4. and a *note __hash__(): cf5. method.
You must then make sure that the hash value for all such wrapper objects
that reside in a dictionary (or other hash based structure), remain
fixed while the object is in the dictionary (or other structure).

     class ListWrapper:
         def __init__(self, the_list):
             self.the_list = the_list

         def __eq__(self, other):
             return self.the_list == other.the_list

         def __hash__(self):
             l = self.the_list
             result = 98767 - len(l)*555
             for i, el in enumerate(l):
                 try:
                     result = result + (hash(el) % 9999999) * 1001 + i
                 except Exception:
                     result = (result % 7777777) + i * 333
             return result

Note that the hash computation is complicated by the possibility that
some members of the list may be unhashable and also by the possibility
of arithmetic overflow.

Furthermore it must always be the case that if ‘o1 == o2’ (ie
‘o1.__eq__(o2) is True’) then ‘hash(o1) == hash(o2)’ (ie, ‘o1.__hash__()
== o2.__hash__()’), regardless of whether the object is in a dictionary
or not.  If you fail to meet these restrictions dictionaries and other
hash based structures will misbehave.

In the case of ‘ListWrapper’, whenever the wrapper object is in a
dictionary the wrapped list must not change to avoid anomalies.  Don’t
do this unless you are prepared to think hard about the requirements and
the consequences of not meeting them correctly.  Consider yourself
warned.


File: python.info,  Node: Why doesn’t list sort return the sorted list?,  Next: How do you specify and enforce an interface spec in Python?,  Prev: Why must dictionary keys be immutable?,  Up: Design and History FAQ

10.3.21 Why doesn’t list.sort() return the sorted list?
-------------------------------------------------------

In situations where performance matters, making a copy of the list just
to sort it would be wasteful.  Therefore, *note list.sort(): dca. sorts
the list in place.  In order to remind you of that fact, it does not
return the sorted list.  This way, you won’t be fooled into accidentally
overwriting a list when you need a sorted copy but also need to keep the
unsorted version around.

If you want to return a new list, use the built-in *note sorted(): dc9.
function instead.  This function creates a new list from a provided
iterable, sorts it and returns it.  For example, here’s how to iterate
over the keys of a dictionary in sorted order:

     for key in sorted(mydict):
         ...  # do whatever with mydict[key]...


File: python.info,  Node: How do you specify and enforce an interface spec in Python?,  Next: Why is there no goto?,  Prev: Why doesn’t list sort return the sorted list?,  Up: Design and History FAQ

10.3.22 How do you specify and enforce an interface spec in Python?
-------------------------------------------------------------------

An interface specification for a module as provided by languages such as
C++ and Java describes the prototypes for the methods and functions of
the module.  Many feel that compile-time enforcement of interface
specifications helps in the construction of large programs.

Python 2.6 adds an *note abc: 4. module that lets you define Abstract
Base Classes (ABCs).  You can then use *note isinstance(): 2ad. and
*note issubclass(): 9c6. to check whether an instance or a class
implements a particular ABC. The *note collections.abc: 1f. module
defines a set of useful ABCs such as *note Iterable: 2691, *note
Container: 2693, and *note MutableMapping: 12b4.

For Python, many of the advantages of interface specifications can be
obtained by an appropriate test discipline for components.

A good test suite for a module can both provide a regression test and
serve as a module interface specification and a set of examples.  Many
Python modules can be run as a script to provide a simple «self test.»
Even modules which use complex external interfaces can often be tested
in isolation using trivial «stub» emulations of the external interface.
The *note doctest: 3e. and *note unittest: 10c. modules or third-party
test frameworks can be used to construct exhaustive test suites that
exercise every line of code in a module.

An appropriate testing discipline can help build large complex
applications in Python as well as having interface specifications would.
In fact, it can be better because an interface specification cannot test
certain properties of a program.  For example, the *note list.append():
8dd. method is expected to add new elements to the end of some internal
list; an interface specification cannot test that your *note
list.append(): 8dd. implementation will actually do this correctly, but
it’s trivial to check this property in a test suite.

Writing test suites is very helpful, and you might want to design your
code to make it easily tested.  One increasingly popular technique,
test-driven development, calls for writing parts of the test suite
first, before you write any of the actual code.  Of course Python allows
you to be sloppy and not write test cases at all.


File: python.info,  Node: Why is there no goto?,  Next: Why can’t raw strings r-strings end with a backslash?,  Prev: How do you specify and enforce an interface spec in Python?,  Up: Design and History FAQ

10.3.23 Why is there no goto?
-----------------------------

In the 1970s people realized that unrestricted goto could lead to messy
«spaghetti» code that was hard to understand and revise.  In a
high-level language, it is also unneeded as long as there are ways to
branch (in Python, with *note if: 181. statements and *note or: 34d,
*note and: 349, and *note if: 181./*note else: 17c. expressions) and
loop (with *note while: 195b. and *note for: 34a. statements, possibly
containing *note continue: 180. and *note break: 17f.).

One can also use exceptions to provide a «structured goto» that works
even across function calls.  Many feel that exceptions can conveniently
emulate all reasonable uses of the ‘go’ or ‘goto’ constructs of C,
Fortran, and other languages.  For example:

     class label(Exception): pass  # declare a label

     try:
         ...
         if condition: raise label()  # goto label
         ...
     except label:  # where to goto
         pass
     ...

This doesn’t allow you to jump into the middle of a loop, but that’s
usually considered an abuse of ‘goto’ anyway.  Use sparingly.


File: python.info,  Node: Why can’t raw strings r-strings end with a backslash?,  Next: Why doesn’t Python have a «with» statement for attribute assignments?,  Prev: Why is there no goto?,  Up: Design and History FAQ

10.3.24 Why can’t raw strings (r-strings) end with a backslash?
---------------------------------------------------------------

More precisely, they can’t end with an odd number of backslashes: the
unpaired backslash at the end escapes the closing quote character,
leaving an unterminated string.

Raw strings were designed to ease creating input for processors (chiefly
regular expression engines) that want to do their own backslash escape
processing.  Such processors consider an unmatched trailing backslash to
be an error anyway, so raw strings disallow that.  In return, they allow
you to pass on the string quote character by escaping it with a
backslash.  These rules work well when r-strings are used for their
intended purpose.

If you’re trying to build Windows pathnames, note that all Windows
system calls accept forward slashes too:

     f = open("/mydir/file.txt")  # works fine!

If you’re trying to build a pathname for a DOS command, try e.g.  one of

     dir = r"\this\is\my\dos\dir" "\\"
     dir = r"\this\is\my\dos\dir\ "[:-1]
     dir = "\\this\\is\\my\\dos\\dir\\"


File: python.info,  Node: Why doesn’t Python have a «with» statement for attribute assignments?,  Next: Why don’t generators support the with statement?,  Prev: Why can’t raw strings r-strings end with a backslash?,  Up: Design and History FAQ

10.3.25 Why doesn’t Python have a «with» statement for attribute assignments?
-----------------------------------------------------------------------------

Python has a *note with: 186. statement that wraps the execution of a
block, calling code on the entrance and exit from the block.  Some
languages have a construct that looks like this:

     with obj:
         a = 1               # equivalent to obj.a = 1
         total = total + 1   # obj.total = obj.total + 1

In Python, such a construct would be ambiguous.

Other languages, such as Object Pascal, Delphi, and C++, use static
types, so it’s possible to know, in an unambiguous way, what member is
being assigned to.  This is the main point of static typing – the
compiler 'always' knows the scope of every variable at compile time.

Python uses dynamic types.  It is impossible to know in advance which
attribute will be referenced at runtime.  Member attributes may be added
or removed from objects on the fly.  This makes it impossible to know,
from a simple reading, what attribute is being referenced: a local one,
a global one, or a member attribute?

For instance, take the following incomplete snippet:

     def foo(a):
         with a:
             print(x)

The snippet assumes that ‘a’ must have a member attribute called ‘x’.
However, there is nothing in Python that tells the interpreter this.
What should happen if ‘a’ is, let us say, an integer?  If there is a
global variable named ‘x’, will it be used inside the *note with: 186.
block?  As you see, the dynamic nature of Python makes such choices much
harder.

The primary benefit of *note with: 186. and similar language features
(reduction of code volume) can, however, easily be achieved in Python by
assignment.  Instead of:

     function(args).mydict[index][index].a = 21
     function(args).mydict[index][index].b = 42
     function(args).mydict[index][index].c = 63

write this:

     ref = function(args).mydict[index][index]
     ref.a = 21
     ref.b = 42
     ref.c = 63

This also has the side-effect of increasing execution speed because name
bindings are resolved at run-time in Python, and the second version only
needs to perform the resolution once.

Similar proposals that would introduce syntax to further reduce code
volume, such as using a “leading dot”, have been rejected in favour of
explicitness (see
‘https://mail.python.org/pipermail/python-ideas/2016-May/040070.html’).


File: python.info,  Node: Why don’t generators support the with statement?,  Next: Why are colons required for the if/while/def/class statements?,  Prev: Why doesn’t Python have a «with» statement for attribute assignments?,  Up: Design and History FAQ

10.3.26 Why don’t generators support the with statement?
--------------------------------------------------------

For technical reasons, a generator used directly as a context manager
would not work correctly.  When, as is most common, a generator is used
as an iterator run to completion, no closing is needed.  When it is,
wrap it as *note contextlib.closing(generator): 1591. in the *note with:
186. statement.


File: python.info,  Node: Why are colons required for the if/while/def/class statements?,  Next: Why does Python allow commas at the end of lists and tuples?,  Prev: Why don’t generators support the with statement?,  Up: Design and History FAQ

10.3.27 Why are colons required for the if/while/def/class statements?
----------------------------------------------------------------------

The colon is required primarily to enhance readability (one of the
results of the experimental ABC language).  Consider this:

     if a == b
         print(a)

versus

     if a == b:
         print(a)

Notice how the second one is slightly easier to read.  Notice further
how a colon sets off the example in this FAQ answer; it’s a standard
usage in English.

Another minor reason is that the colon makes it easier for editors with
syntax highlighting; they can look for colons to decide when indentation
needs to be increased instead of having to do a more elaborate parsing
of the program text.


File: python.info,  Node: Why does Python allow commas at the end of lists and tuples?,  Prev: Why are colons required for the if/while/def/class statements?,  Up: Design and History FAQ

10.3.28 Why does Python allow commas at the end of lists and tuples?
--------------------------------------------------------------------

Python lets you add a trailing comma at the end of lists, tuples, and
dictionaries:

     [1, 2, 3,]
     ('a', 'b', 'c',)
     d = {
         "A": [1, 5],
         "B": [6, 7],  # last trailing comma is optional but good style
     }

There are several reasons to allow this.

When you have a literal value for a list, tuple, or dictionary spread
across multiple lines, it’s easier to add more elements because you
don’t have to remember to add a comma to the previous line.  The lines
can also be reordered without creating a syntax error.

Accidentally omitting the comma can lead to errors that are hard to
diagnose.  For example:

     x = [
       "fee",
       "fie"
       "foo",
       "fum"
     ]

This list looks like it has four elements, but it actually contains
three: «fee», «fiefoo» and «fum».  Always adding the comma avoids this
source of error.

Allowing the trailing comma may also make programmatic code generation
easier.


File: python.info,  Node: Library and Extension FAQ,  Next: Extending/Embedding FAQ,  Prev: Design and History FAQ,  Up: Python Frequently Asked Questions

10.4 Library and Extension FAQ
==============================

* Menu:

* General Library Questions::
* Common tasks::
* Threads::
* Input and Output::
* Network/Internet Programming::
* Databases::
* Mathematics and Numerics::


File: python.info,  Node: General Library Questions,  Next: Common tasks,  Up: Library and Extension FAQ

10.4.1 General Library Questions
--------------------------------

* Menu:

* How do I find a module or application to perform task X?::
* Where is the math.py (socket.py, regex.py, etc.) source file?: Where is the math py socket py regex py etc source file?.
* How do I make a Python script executable on Unix?::
* Is there a curses/termcap package for Python?::
* Is there an equivalent to C’s onexit() in Python?: Is there an equivalent to C’s onexit in Python?.
* Why don’t my signal handlers work?::


File: python.info,  Node: How do I find a module or application to perform task X?,  Next: Where is the math py socket py regex py etc source file?,  Up: General Library Questions

10.4.1.1 How do I find a module or application to perform task X?
.................................................................

Check *note the Library Reference: 149. to see if there’s a relevant
standard library module.  (Eventually you’ll learn what’s in the
standard library and will be able to skip this step.)

For third-party packages, search the Python Package Index(1) or try
Google(2) or another web search engine.  Searching for «Python» plus a
keyword or two for your topic of interest will usually find something
helpful.

   ---------- Footnotes ----------

   (1) https://pypi.org

   (2) https://www.google.com


File: python.info,  Node: Where is the math py socket py regex py etc source file?,  Next: How do I make a Python script executable on Unix?,  Prev: How do I find a module or application to perform task X?,  Up: General Library Questions

10.4.1.2 Where is the math.py (socket.py, regex.py, etc.) source file?
......................................................................

If you can’t find a source file for a module it may be a built-in or
dynamically loaded module implemented in C, C++ or other compiled
language.  In this case you may not have the source file or it may be
something like ‘mathmodule.c’, somewhere in a C source directory (not on
the Python Path).

There are (at least) three kinds of modules in Python:

  1. modules written in Python (.py);

  2. modules written in C and dynamically loaded (.dll, .pyd, .so, .sl,
     etc);

  3. modules written in C and linked with the interpreter; to get a list
     of these, type:

          import sys
          print(sys.builtin_module_names)


File: python.info,  Node: How do I make a Python script executable on Unix?,  Next: Is there a curses/termcap package for Python?,  Prev: Where is the math py socket py regex py etc source file?,  Up: General Library Questions

10.4.1.3 How do I make a Python script executable on Unix?
..........................................................

You need to do two things: the script file’s mode must be executable and
the first line must begin with ‘#!’ followed by the path of the Python
interpreter.

The first is done by executing ‘chmod +x scriptfile’ or perhaps ‘chmod
755 scriptfile’.

The second can be done in a number of ways.  The most straightforward
way is to write

     #!/usr/local/bin/python

as the very first line of your file, using the pathname for where the
Python interpreter is installed on your platform.

If you would like the script to be independent of where the Python
interpreter lives, you can use the ‘env’ program.  Almost all Unix
variants support the following, assuming the Python interpreter is in a
directory on the user’s ‘PATH’:

     #!/usr/bin/env python

'Don’t' do this for CGI scripts.  The ‘PATH’ variable for CGI scripts is
often very minimal, so you need to use the actual absolute pathname of
the interpreter.

Occasionally, a user’s environment is so full that the ‘/usr/bin/env’
program fails; or there’s no env program at all.  In that case, you can
try the following hack (due to Alex Rezinsky):

     #! /bin/sh
     """:"
     exec python $0 ${1+"$@"}
     """

The minor disadvantage is that this defines the script’s __doc__ string.
However, you can fix that by adding

     __doc__ = """...Whatever..."""


File: python.info,  Node: Is there a curses/termcap package for Python?,  Next: Is there an equivalent to C’s onexit in Python?,  Prev: How do I make a Python script executable on Unix?,  Up: General Library Questions

10.4.1.4 Is there a curses/termcap package for Python?
......................................................

For Unix variants: The standard Python source distribution comes with a
curses module in the Modules(1) subdirectory, though it’s not compiled
by default.  (Note that this is not available in the Windows
distribution – there is no curses module for Windows.)

The *note curses: 2f. module supports basic curses features as well as
many additional functions from ncurses and SYSV curses such as colour,
alternative character set support, pads, and mouse support.  This means
the module isn’t compatible with operating systems that only have BSD
curses, but there don’t seem to be any currently maintained OSes that
fall into this category.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Modules


File: python.info,  Node: Is there an equivalent to C’s onexit in Python?,  Next: Why don’t my signal handlers work?,  Prev: Is there a curses/termcap package for Python?,  Up: General Library Questions

10.4.1.5 Is there an equivalent to C’s onexit() in Python?
..........................................................

The *note atexit: d. module provides a register function that is similar
to C’s ‘onexit()’.


File: python.info,  Node: Why don’t my signal handlers work?,  Prev: Is there an equivalent to C’s onexit in Python?,  Up: General Library Questions

10.4.1.6 Why don’t my signal handlers work?
...........................................

The most common problem is that the signal handler is declared with the
wrong argument list.  It is called as

     handler(signum, frame)

so it should be declared with two parameters:

     def handler(signum, frame):
         ...


File: python.info,  Node: Common tasks,  Next: Threads,  Prev: General Library Questions,  Up: Library and Extension FAQ

10.4.2 Common tasks
-------------------

* Menu:

* How do I test a Python program or component?::
* How do I create documentation from doc strings?::
* How do I get a single keypress at a time?::


File: python.info,  Node: How do I test a Python program or component?,  Next: How do I create documentation from doc strings?,  Up: Common tasks

10.4.2.1 How do I test a Python program or component?
.....................................................

Python comes with two testing frameworks.  The *note doctest: 3e. module
finds examples in the docstrings for a module and runs them, comparing
the output with the expected output given in the docstring.

The *note unittest: 10c. module is a fancier testing framework modelled
on Java and Smalltalk testing frameworks.

To make testing easier, you should use good modular design in your
program.  Your program should have almost all functionality encapsulated
in either functions or class methods – and this sometimes has the
surprising and delightful effect of making the program run faster
(because local variable accesses are faster than global accesses).
Furthermore the program should avoid depending on mutating global
variables, since this makes testing much more difficult to do.

The «global main logic» of your program may be as simple as

     if __name__ == "__main__":
         main_logic()

at the bottom of the main module of your program.

Once your program is organized as a tractable collection of function and
class behaviours, you should write test functions that exercise the
behaviours.  A test suite that automates a sequence of tests can be
associated with each module.  This sounds like a lot of work, but since
Python is so terse and flexible it’s surprisingly easy.  You can make
coding much more pleasant and fun by writing your test functions in
parallel with the «production code», since this makes it easy to find
bugs and even design flaws earlier.

«Support modules» that are not intended to be the main module of a
program may include a self-test of the module.

     if __name__ == "__main__":
         self_test()

Even programs that interact with complex external interfaces may be
tested when the external interfaces are unavailable by using «fake»
interfaces implemented in Python.


File: python.info,  Node: How do I create documentation from doc strings?,  Next: How do I get a single keypress at a time?,  Prev: How do I test a Python program or component?,  Up: Common tasks

10.4.2.2 How do I create documentation from doc strings?
........................................................

The *note pydoc: ba. module can create HTML from the doc strings in your
Python source code.  An alternative for creating API documentation
purely from docstrings is epydoc(1).  Sphinx(2) can also include
docstring content.

   ---------- Footnotes ----------

   (1) https://epydoc.sourceforge.net/

   (2) https://www.sphinx-doc.org


File: python.info,  Node: How do I get a single keypress at a time?,  Prev: How do I create documentation from doc strings?,  Up: Common tasks

10.4.2.3 How do I get a single keypress at a time?
..................................................

For Unix variants there are several solutions.  It’s straightforward to
do this using curses, but curses is a fairly large module to learn.


File: python.info,  Node: Threads,  Next: Input and Output,  Prev: Common tasks,  Up: Library and Extension FAQ

10.4.3 Threads
--------------

* Menu:

* How do I program using threads?::
* None of my threads seem to run; why?: None of my threads seem to run why?.
* How do I parcel out work among a bunch of worker threads?::
* What kinds of global value mutation are thread-safe?::
* Can’t we get rid of the Global Interpreter Lock?::


File: python.info,  Node: How do I program using threads?,  Next: None of my threads seem to run why?,  Up: Threads

10.4.3.1 How do I program using threads?
........................................

Be sure to use the *note threading: f3. module and not the *note
_thread: 2. module.  The *note threading: f3. module builds convenient
abstractions on top of the low-level primitives provided by the *note
_thread: 2. module.


File: python.info,  Node: None of my threads seem to run why?,  Next: How do I parcel out work among a bunch of worker threads?,  Prev: How do I program using threads?,  Up: Threads

10.4.3.2 None of my threads seem to run: why?
.............................................

As soon as the main thread exits, all threads are killed.  Your main
thread is running too quickly, giving the threads no time to do any
work.

A simple fix is to add a sleep to the end of the program that’s long
enough for all the threads to finish:

     import threading, time

     def thread_task(name, n):
         for i in range(n):
             print(name, i)

     for i in range(10):
         T = threading.Thread(target=thread_task, args=(str(i), i))
         T.start()

     time.sleep(10)  # <---------------------------!

But now (on many platforms) the threads don’t run in parallel, but
appear to run sequentially, one at a time!  The reason is that the OS
thread scheduler doesn’t start a new thread until the previous thread is
blocked.

A simple fix is to add a tiny sleep to the start of the run function:

     def thread_task(name, n):
         time.sleep(0.001)  # <--------------------!
         for i in range(n):
             print(name, i)

     for i in range(10):
         T = threading.Thread(target=thread_task, args=(str(i), i))
         T.start()

     time.sleep(10)

Instead of trying to guess a good delay value for *note time.sleep():
8ad, it’s better to use some kind of semaphore mechanism.  One idea is
to use the *note queue: bb. module to create a queue object, let each
thread append a token to the queue when it finishes, and let the main
thread read as many tokens from the queue as there are threads.


File: python.info,  Node: How do I parcel out work among a bunch of worker threads?,  Next: What kinds of global value mutation are thread-safe?,  Prev: None of my threads seem to run why?,  Up: Threads

10.4.3.3 How do I parcel out work among a bunch of worker threads?
..................................................................

The easiest way is to use the *note concurrent.futures: 24. module,
especially the *note ThreadPoolExecutor: 94a. class.

Or, if you want fine control over the dispatching algorithm, you can
write your own logic manually.  Use the *note queue: bb. module to
create a queue containing a list of jobs.  The *note Queue: 159c. class
maintains a list of objects and has a ‘.put(obj)’ method that adds items
to the queue and a ‘.get()’ method to return them.  The class will take
care of the locking necessary to ensure that each job is handed out
exactly once.

Here’s a trivial example:

     import threading, queue, time

     # The worker thread gets jobs off the queue.  When the queue is empty, it
     # assumes there will be no more work and exits.
     # (Realistically workers will run until terminated.)
     def worker():
         print('Running worker')
         time.sleep(0.1)
         while True:
             try:
                 arg = q.get(block=False)
             except queue.Empty:
                 print('Worker', threading.current_thread(), end=' ')
                 print('queue empty')
                 break
             else:
                 print('Worker', threading.current_thread(), end=' ')
                 print('running with argument', arg)
                 time.sleep(0.5)

     # Create queue
     q = queue.Queue()

     # Start a pool of 5 workers
     for i in range(5):
         t = threading.Thread(target=worker, name='worker %i' % (i+1))
         t.start()

     # Begin adding work to the queue
     for i in range(50):
         q.put(i)

     # Give threads time to run
     print('Main thread sleeping')
     time.sleep(5)

When run, this will produce the following output:

     Running worker
     Running worker
     Running worker
     Running worker
     Running worker
     Main thread sleeping
     Worker <Thread(worker 1, started 130283832797456)> running with argument 0
     Worker <Thread(worker 2, started 130283824404752)> running with argument 1
     Worker <Thread(worker 3, started 130283816012048)> running with argument 2
     Worker <Thread(worker 4, started 130283807619344)> running with argument 3
     Worker <Thread(worker 5, started 130283799226640)> running with argument 4
     Worker <Thread(worker 1, started 130283832797456)> running with argument 5
     ...

Consult the module’s documentation for more details; the *note Queue:
159c. class provides a featureful interface.


File: python.info,  Node: What kinds of global value mutation are thread-safe?,  Next: Can’t we get rid of the Global Interpreter Lock?,  Prev: How do I parcel out work among a bunch of worker threads?,  Up: Threads

10.4.3.4 What kinds of global value mutation are thread-safe?
.............................................................

A *note global interpreter lock: 474. (GIL) is used internally to ensure
that only one thread runs in the Python VM at a time.  In general,
Python offers to switch among threads only between bytecode
instructions; how frequently it switches can be set via *note
sys.setswitchinterval(): b46.  Each bytecode instruction and therefore
all the C implementation code reached from each instruction is therefore
atomic from the point of view of a Python program.

In theory, this means an exact accounting requires an exact
understanding of the PVM bytecode implementation.  In practice, it means
that operations on shared variables of built-in data types (ints, lists,
dicts, etc) that «look atomic» really are.

For example, the following operations are all atomic (L, L1, L2 are
lists, D, D1, D2 are dicts, x, y are objects, i, j are ints):

     L.append(x)
     L1.extend(L2)
     x = L[i]
     x = L.pop()
     L1[i:j] = L2
     L.sort()
     x = y
     x.field = y
     D[x] = y
     D1.update(D2)
     D.keys()

These aren’t:

     i = i+1
     L.append(L[-1])
     L[i] = L[j]
     D[x] = D[x] + 1

Operations that replace other objects may invoke those other objects”
*note __del__(): 11ff. method when their reference count reaches zero,
and that can affect things.  This is especially true for the mass
updates to dictionaries and lists.  When in doubt, use a mutex!


File: python.info,  Node: Can’t we get rid of the Global Interpreter Lock?,  Prev: What kinds of global value mutation are thread-safe?,  Up: Threads

10.4.3.5 Can’t we get rid of the Global Interpreter Lock?
.........................................................

The *note global interpreter lock: 474. (GIL) is often seen as a
hindrance to Python’s deployment on high-end multiprocessor server
machines, because a multi-threaded Python program effectively only uses
one CPU, due to the insistence that (almost) all Python code can only
run while the GIL is held.

With the approval of PEP 703(1) work is now underway to remove the GIL
from the CPython implementation of Python.  Initially it will be
implemented as an optional compiler flag when building the interpreter,
and so separate builds will be available with and without the GIL.
Long-term, the hope is to settle on a single build, once the performance
implications of removing the GIL are fully understood.  Python 3.13 is
likely to be the first release containing this work, although it may not
be completely functional in this release.

The current work to remove the GIL is based on a fork of Python 3.9 with
the GIL removed(2) by Sam Gross.  Prior to that, in the days of Python
1.5, Greg Stein actually implemented a comprehensive patch set (the
«free threading» patches) that removed the GIL and replaced it with
fine-grained locking.  Adam Olsen did a similar experiment in his
python-safethread(3) project.  Unfortunately, both of these earlier
experiments exhibited a sharp drop in single-thread performance (at
least 30% slower), due to the amount of fine-grained locking necessary
to compensate for the removal of the GIL. The Python 3.9 fork is the
first attempt at removing the GIL with an acceptable performance impact.

The presence of the GIL in current Python releases doesn’t mean that you
can’t make good use of Python on multi-CPU machines!  You just have to
be creative with dividing the work up between multiple 'processes'
rather than multiple 'threads'.  The *note ProcessPoolExecutor: 1d6.
class in the new *note concurrent.futures: 24. module provides an easy
way of doing so; the *note multiprocessing: 98. module provides a
lower-level API in case you want more control over dispatching of tasks.

Judicious use of C extensions will also help; if you use a C extension
to perform a time-consuming task, the extension can release the GIL
while the thread of execution is in the C code and allow other threads
to get some work done.  Some standard library modules such as *note
zlib: 139. and *note hashlib: 6c. already do this.

An alternative approach to reducing the impact of the GIL is to make the
GIL a per-interpreter-state lock rather than truly global.  This was
*note first implemented in Python 3.12: 670. and is available in the C
API. A Python interface to it is expected in Python 3.13.  The main
limitation to it at the moment is likely to be 3rd party extension
modules, since these must be written with multiple interpreters in mind
in order to be usable, so many older extension modules will not be
usable.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0703/

   (2) https://github.com/colesbury/nogil

   (3) https://code.google.com/archive/p/python-safethread


File: python.info,  Node: Input and Output,  Next: Network/Internet Programming,  Prev: Threads,  Up: Library and Extension FAQ

10.4.4 Input and Output
-----------------------

* Menu:

* How do I delete a file? (And other file questions…): How do I delete a file? And other file questions….
* How do I copy a file?::
* How do I read (or write) binary data?: How do I read or write binary data?.
* I can’t seem to use os.read() on a pipe created with os.popen(); why?: I can’t seem to use os read on a pipe created with os popen ; why?.
* How do I access the serial (RS232) port?: How do I access the serial RS232 port?.
* Why doesn’t closing sys.stdout (stdin, stderr) really close it?: Why doesn’t closing sys stdout stdin stderr really close it?.


File: python.info,  Node: How do I delete a file? And other file questions…,  Next: How do I copy a file?,  Up: Input and Output

10.4.4.1 How do I delete a file? (And other file questions…)
............................................................

Use ‘os.remove(filename)’ or ‘os.unlink(filename)’; for documentation,
see the *note os: a5. module.  The two functions are identical; *note
unlink(): 12fd. is simply the name of the Unix system call for this
function.

To remove a directory, use *note os.rmdir(): 12fb.; use *note
os.mkdir(): 52c. to create one.  ‘os.makedirs(path)’ will create any
intermediate directories in ‘path’ that don’t exist.
‘os.removedirs(path)’ will remove intermediate directories as long as
they’re empty; if you want to delete an entire directory tree and its
contents, use *note shutil.rmtree(): 356.

To rename a file, use ‘os.rename(old_path, new_path)’.

To truncate a file, open it using ‘f = open(filename, "rb+")’, and use
‘f.truncate(offset)’; offset defaults to the current seek position.
There’s also ‘os.ftruncate(fd, offset)’ for files opened with *note
os.open(): f94, where 'fd' is the file descriptor (a small integer).

The *note shutil: ca. module also contains a number of functions to work
on files including *note copyfile(): c50, *note copytree(): c20, and
*note rmtree(): 356.


File: python.info,  Node: How do I copy a file?,  Next: How do I read or write binary data?,  Prev: How do I delete a file? And other file questions…,  Up: Input and Output

10.4.4.2 How do I copy a file?
..............................

The *note shutil: ca. module contains a *note copyfile(): c50. function.
Note that on Windows NTFS volumes, it does not copy alternate data
streams(1) nor resource forks(2) on macOS HFS+ volumes, though both are
now rarely used.  It also doesn’t copy file permissions and metadata,
though using *note shutil.copy2(): c52. instead will preserve most
(though not all) of it.

   ---------- Footnotes ----------

   (1) https://en.wikipedia.org/wiki/NTFS#Alternate_data_stream_(ADS)

   (2) https://en.wikipedia.org/wiki/Resource_fork


File: python.info,  Node: How do I read or write binary data?,  Next: I can’t seem to use os read on a pipe created with os popen ; why?,  Prev: How do I copy a file?,  Up: Input and Output

10.4.4.3 How do I read (or write) binary data?
..............................................

To read or write complex binary data formats, it’s best to use the *note
struct: db. module.  It allows you to take a string containing binary
data (usually numbers) and convert it to Python objects; and vice versa.

For example, the following code reads two 2-byte integers and one 4-byte
integer in big-endian format from a file:

     import struct

     with open(filename, "rb") as f:
         s = f.read(8)
         x, y, z = struct.unpack(">hhl", s)

The “>” in the format string forces big-endian data; the letter “h”
reads one «short integer» (2 bytes), and “l” reads one «long integer» (4
bytes) from the string.

For data that is more regular (e.g.  a homogeneous list of ints or
floats), you can also use the *note array: 8. module.

     Nota: To read and write binary data, it is mandatory to open the
     file in binary mode (here, passing ‘"rb"’ to *note open(): 316.).
     If you use ‘"r"’ instead (the default), the file will be open in
     text mode and ‘f.read()’ will return *note str: 169. objects rather
     than *note bytes: 192. objects.


File: python.info,  Node: I can’t seem to use os read on a pipe created with os popen ; why?,  Next: How do I access the serial RS232 port?,  Prev: How do I read or write binary data?,  Up: Input and Output

10.4.4.4 I can’t seem to use os.read() on a pipe created with os.popen(); why?
..............................................................................

*note os.read(): f97. is a low-level function which takes a file
descriptor, a small integer representing the opened file.  *note
os.popen(): 31a. creates a high-level file object, the same type
returned by the built-in *note open(): 316. function.  Thus, to read 'n'
bytes from a pipe 'p' created with *note os.popen(): 31a, you need to
use ‘p.read(n)’.


File: python.info,  Node: How do I access the serial RS232 port?,  Next: Why doesn’t closing sys stdout stdin stderr really close it?,  Prev: I can’t seem to use os read on a pipe created with os popen ; why?,  Up: Input and Output

10.4.4.5 How do I access the serial (RS232) port?
.................................................

For Win32, OSX, Linux, BSD, Jython, IronPython:

     pyserial(1)

For Unix, see a Usenet post by Mitch Chapman:

     ‘https://groups.google.com/groups?selm=34A04430.CF9@ohioee.com’

   ---------- Footnotes ----------

   (1) https://pypi.org/project/pyserial/


File: python.info,  Node: Why doesn’t closing sys stdout stdin stderr really close it?,  Prev: How do I access the serial RS232 port?,  Up: Input and Output

10.4.4.6 Why doesn’t closing sys.stdout (stdin, stderr) really close it?
........................................................................

Python *note file objects: 13cb. are a high-level layer of abstraction
on low-level C file descriptors.

For most file objects you create in Python via the built-in *note
open(): 316. function, ‘f.close()’ marks the Python file object as being
closed from Python’s point of view, and also arranges to close the
underlying C file descriptor.  This also happens automatically in ‘f’’s
destructor, when ‘f’ becomes garbage.

But stdin, stdout and stderr are treated specially by Python, because of
the special status also given to them by C. Running ‘sys.stdout.close()’
marks the Python-level file object as being closed, but does 'not' close
the associated C file descriptor.

To close the underlying C file descriptor for one of these three, you
should first be sure that’s what you really want to do (e.g., you may
confuse extension modules trying to do I/O). If it is, use *note
os.close(): d6d.:

     os.close(stdin.fileno())
     os.close(stdout.fileno())
     os.close(stderr.fileno())

Or you can use the numeric constants 0, 1 and 2, respectively.


File: python.info,  Node: Network/Internet Programming,  Next: Databases,  Prev: Input and Output,  Up: Library and Extension FAQ

10.4.5 Network/Internet Programming
-----------------------------------

* Menu:

* What WWW tools are there for Python?::
* What module should I use to help with generating HTML?::
* How do I send mail from a Python script?::
* How do I avoid blocking in the connect() method of a socket?: How do I avoid blocking in the connect method of a socket?.


File: python.info,  Node: What WWW tools are there for Python?,  Next: What module should I use to help with generating HTML?,  Up: Network/Internet Programming

10.4.5.1 What WWW tools are there for Python?
.............................................

See the chapters titled *note Internet Protocols and Support: 3ea4. and
*note Internet Data Handling: 3a97. in the Library Reference Manual.
Python has many modules that will help you build server-side and
client-side web systems.

A summary of available frameworks is maintained by Paul Boddie at
‘https://wiki.python.org/moin/WebProgramming’.


File: python.info,  Node: What module should I use to help with generating HTML?,  Next: How do I send mail from a Python script?,  Prev: What WWW tools are there for Python?,  Up: Network/Internet Programming

10.4.5.2 What module should I use to help with generating HTML?
...............................................................

You can find a collection of useful links on the Web Programming wiki
page(1).

   ---------- Footnotes ----------

   (1) https://wiki.python.org/moin/WebProgramming


File: python.info,  Node: How do I send mail from a Python script?,  Next: How do I avoid blocking in the connect method of a socket?,  Prev: What module should I use to help with generating HTML?,  Up: Network/Internet Programming

10.4.5.3 How do I send mail from a Python script?
.................................................

Use the standard library module *note smtplib: cf.

Here’s a very simple interactive mail sender that uses it.  This method
will work on any host that supports an SMTP listener.

     import sys, smtplib

     fromaddr = input("From: ")
     toaddrs  = input("To: ").split(',')
     print("Enter message, end with ^D:")
     msg = ''
     while True:
         line = sys.stdin.readline()
         if not line:
             break
         msg += line

     # The actual mail send
     server = smtplib.SMTP('localhost')
     server.sendmail(fromaddr, toaddrs, msg)
     server.quit()

A Unix-only alternative uses sendmail.  The location of the sendmail
program varies between systems; sometimes it is ‘/usr/lib/sendmail’,
sometimes ‘/usr/sbin/sendmail’.  The sendmail manual page will help you
out.  Here’s some sample code:

     import os

     SENDMAIL = "/usr/sbin/sendmail"  # sendmail location
     p = os.popen("%s -t -i" % SENDMAIL, "w")
     p.write("To: receiver@example.com\n")
     p.write("Subject: test\n")
     p.write("\n")  # blank line separating headers from body
     p.write("Some text\n")
     p.write("some more text\n")
     sts = p.close()
     if sts != 0:
         print("Sendmail exit status", sts)


File: python.info,  Node: How do I avoid blocking in the connect method of a socket?,  Prev: How do I send mail from a Python script?,  Up: Network/Internet Programming

10.4.5.4 How do I avoid blocking in the connect() method of a socket?
.....................................................................

The *note select: c6. module is commonly used to help with asynchronous
I/O on sockets.

To prevent the TCP connect from blocking, you can set the socket to
non-blocking mode.  Then when you do the *note connect(): fa5, you will
either connect immediately (unlikely) or get an exception that contains
the error number as ‘.errno’.  ‘errno.EINPROGRESS’ indicates that the
connection is in progress, but hasn’t finished yet.  Different OSes will
return different values, so you’re going to have to check what’s
returned on your system.

You can use the *note connect_ex(): 1740. method to avoid creating an
exception.  It will just return the errno value.  To poll, you can call
*note connect_ex(): 1740. again later – ‘0’ or ‘errno.EISCONN’ indicate
that you’re connected – or you can pass this socket to *note
select.select(): fa2. to check if it’s writable.

     Nota: The *note asyncio: b. module provides a general purpose
     single-threaded and concurrent asynchronous library, which can be
     used for writing non-blocking network code.  The third-party
     Twisted(1) library is a popular and feature-rich alternative.

   ---------- Footnotes ----------

   (1) https://twisted.org/


File: python.info,  Node: Databases,  Next: Mathematics and Numerics,  Prev: Network/Internet Programming,  Up: Library and Extension FAQ

10.4.6 Databases
----------------

* Menu:

* Are there any interfaces to database packages in Python?::
* How do you implement persistent objects in Python?::


File: python.info,  Node: Are there any interfaces to database packages in Python?,  Next: How do you implement persistent objects in Python?,  Up: Databases

10.4.6.1 Are there any interfaces to database packages in Python?
.................................................................

Yes.

Interfaces to disk-based hashes such as *note DBM: 38. and *note GDBM:
37. are also included with standard Python.  There is also the *note
sqlite3: d4. module, which provides a lightweight disk-based relational
database.

Support for most relational databases is available.  See the
DatabaseProgramming wiki page(1) for details.

   ---------- Footnotes ----------

   (1) https://wiki.python.org/moin/DatabaseProgramming


File: python.info,  Node: How do you implement persistent objects in Python?,  Prev: Are there any interfaces to database packages in Python?,  Up: Databases

10.4.6.2 How do you implement persistent objects in Python?
...........................................................

The *note pickle: ab. library module solves this in a very general way
(though you still can’t store things like open files, sockets or
windows), and the *note shelve: c8. library module uses pickle and
(g)dbm to create persistent mappings containing arbitrary Python
objects.


File: python.info,  Node: Mathematics and Numerics,  Prev: Databases,  Up: Library and Extension FAQ

10.4.7 Mathematics and Numerics
-------------------------------

* Menu:

* How do I generate random numbers in Python?::


File: python.info,  Node: How do I generate random numbers in Python?,  Up: Mathematics and Numerics

10.4.7.1 How do I generate random numbers in Python?
....................................................

The standard module *note random: bd. implements a random number
generator.  Usage is simple:

     import random
     random.random()

This returns a random floating-point number in the range [0, 1).

There are also many other specialized generators in this module, such
as:

   * ‘randrange(a, b)’ chooses an integer in the range [a, b).

   * ‘uniform(a, b)’ chooses a floating-point number in the range [a,
     b).

   * ‘normalvariate(mean, sdev)’ samples the normal (Gaussian)
     distribution.

Some higher-level functions operate on sequences directly, such as:

   * ‘choice(S)’ chooses a random element from a given sequence.

   * ‘shuffle(L)’ shuffles a list in-place, i.e.  permutes it randomly.

There’s also a ‘Random’ class you can instantiate to create independent
multiple random number generators.


File: python.info,  Node: Extending/Embedding FAQ,  Next: Python on Windows FAQ,  Prev: Library and Extension FAQ,  Up: Python Frequently Asked Questions

10.5 Extending/Embedding FAQ
============================

* Menu:

* Can I create my own functions in C?::
* Can I create my own functions in C++?::
* Writing C is hard; are there any alternatives?::
* How can I execute arbitrary Python statements from C?::
* How can I evaluate an arbitrary Python expression from C?::
* How do I extract C values from a Python object?::
* How do I use Py_BuildValue() to create a tuple of arbitrary length?: How do I use Py_BuildValue to create a tuple of arbitrary length?.
* How do I call an object’s method from C?::
* How do I catch the output from PyErr_Print() (or anything that prints to stdout/stderr)?: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?.
* How do I access a module written in Python from C?::
* How do I interface to C++ objects from Python?::
* I added a module using the Setup file and the make fails; why?::
* How do I debug an extension?::
* I want to compile a Python module on my Linux system, but some files are missing. Why?: I want to compile a Python module on my Linux system but some files are missing Why?.
* How do I tell «incomplete input» from «invalid input»?::
* How do I find undefined g++ symbols __builtin_new or __pure_virtual?::
* Can I create an object class with some methods implemented in C and others in Python (e.g. through inheritance)?: Can I create an object class with some methods implemented in C and others in Python e g through inheritance ?.


File: python.info,  Node: Can I create my own functions in C?,  Next: Can I create my own functions in C++?,  Up: Extending/Embedding FAQ

10.5.1 Can I create my own functions in C?
------------------------------------------

Yes, you can create built-in modules containing functions, variables,
exceptions and even new types in C. This is explained in the document
*note Extending and Embedding the Python Interpreter: 1fa5.

Most intermediate or advanced Python books will also cover this topic.


File: python.info,  Node: Can I create my own functions in C++?,  Next: Writing C is hard; are there any alternatives?,  Prev: Can I create my own functions in C?,  Up: Extending/Embedding FAQ

10.5.2 Can I create my own functions in C++?
--------------------------------------------

Yes, using the C compatibility features found in C++.  Place ‘extern "C"
{ ... }’ around the Python include files and put ‘extern "C"’ before
each function that is going to be called by the Python interpreter.
Global or static C++ objects with constructors are probably not a good
idea.


File: python.info,  Node: Writing C is hard; are there any alternatives?,  Next: How can I execute arbitrary Python statements from C?,  Prev: Can I create my own functions in C++?,  Up: Extending/Embedding FAQ

10.5.3 Writing C is hard; are there any alternatives?
-----------------------------------------------------

There are a number of alternatives to writing your own C extensions,
depending on what you’re trying to do.  *note Recommended third party
tools: 4e77. offer both simpler and more sophisticated approaches to
creating C and C++ extensions for Python.


File: python.info,  Node: How can I execute arbitrary Python statements from C?,  Next: How can I evaluate an arbitrary Python expression from C?,  Prev: Writing C is hard; are there any alternatives?,  Up: Extending/Embedding FAQ

10.5.4 How can I execute arbitrary Python statements from C?
------------------------------------------------------------

The highest-level function to do this is *note PyRun_SimpleString():
4ef4. which takes a single string argument to be executed in the context
of the module ‘__main__’ and returns ‘0’ for success and ‘-1’ when an
exception occurred (including *note SyntaxError: 18e.).  If you want
more control, use *note PyRun_String(): 1da8.; see the source for *note
PyRun_SimpleString(): 4ef4. in ‘Python/pythonrun.c’.


File: python.info,  Node: How can I evaluate an arbitrary Python expression from C?,  Next: How do I extract C values from a Python object?,  Prev: How can I execute arbitrary Python statements from C?,  Up: Extending/Embedding FAQ

10.5.5 How can I evaluate an arbitrary Python expression from C?
----------------------------------------------------------------

Call the function *note PyRun_String(): 1da8. from the previous question
with the start symbol *note Py_eval_input: 5199.; it parses an
expression, evaluates it and returns its value.


File: python.info,  Node: How do I extract C values from a Python object?,  Next: How do I use Py_BuildValue to create a tuple of arbitrary length?,  Prev: How can I evaluate an arbitrary Python expression from C?,  Up: Extending/Embedding FAQ

10.5.6 How do I extract C values from a Python object?
------------------------------------------------------

That depends on the object’s type.  If it’s a tuple, *note
PyTuple_Size(): 50b0. returns its length and *note PyTuple_GetItem():
4ea0. returns the item at a specified index.  Lists have similar
functions, *note PyList_Size(): 1621. and *note PyList_GetItem(): 5ff.

For bytes, *note PyBytes_Size(): 4f5f. returns its length and *note
PyBytes_AsStringAndSize(): 4f57. provides a pointer to its value and its
length.  Note that Python bytes objects may contain null bytes so C’s
‘strlen()’ should not be used.

To test the type of an object, first make sure it isn’t ‘NULL’, and then
use *note PyBytes_Check(): 15a7, *note PyTuple_Check(): 5369, *note
PyList_Check(): 537a, etc.

There is also a high-level API to Python objects which is provided by
the so-called “abstract” interface – read ‘Include/abstract.h’ for
further details.  It allows interfacing with any kind of Python sequence
using calls like *note PySequence_Length(): 5080, *note
PySequence_GetItem(): 1e1c, etc.  as well as many other useful protocols
such as numbers (*note PyNumber_Index(): a95. et al.)  and mappings in
the PyMapping APIs.


File: python.info,  Node: How do I use Py_BuildValue to create a tuple of arbitrary length?,  Next: How do I call an object’s method from C?,  Prev: How do I extract C values from a Python object?,  Up: Extending/Embedding FAQ

10.5.7 How do I use Py_BuildValue() to create a tuple of arbitrary length?
--------------------------------------------------------------------------

You can’t.  Use *note PyTuple_Pack(): 50af. instead.


File: python.info,  Node: How do I call an object’s method from C?,  Next: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?,  Prev: How do I use Py_BuildValue to create a tuple of arbitrary length?,  Up: Extending/Embedding FAQ

10.5.8 How do I call an object’s method from C?
-----------------------------------------------

The *note PyObject_CallMethod(): 640. function can be used to call an
arbitrary method of an object.  The parameters are the object, the name
of the method to call, a format string like that used with *note
Py_BuildValue(): 3c2, and the argument values:

     PyObject *
     PyObject_CallMethod(PyObject *object, const char *method_name,
                         const char *arg_format, ...);

This works for any object that has methods – whether built-in or
user-defined.  You are responsible for eventually *note Py_DECREF():
791.“ing the return value.

To call, e.g., a file object’s «seek» method with arguments 10, 0
(assuming the file object pointer is «f»):

     res = PyObject_CallMethod(f, "seek", "(ii)", 10, 0);
     if (res == NULL) {
             ... an exception occurred ...
     }
     else {
             Py_DECREF(res);
     }

Note that since *note PyObject_CallObject(): 4e95. 'always' wants a
tuple for the argument list, to call a function without arguments, pass
«()» for the format, and to call a function with one argument, surround
the argument in parentheses, e.g.  «(i)».


File: python.info,  Node: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?,  Next: How do I access a module written in Python from C?,  Prev: How do I call an object’s method from C?,  Up: Extending/Embedding FAQ

10.5.9 How do I catch the output from PyErr_Print() (or anything that prints to stdout/stderr)?
-----------------------------------------------------------------------------------------------

In Python code, define an object that supports the ‘write()’ method.
Assign this object to *note sys.stdout: ccf. and *note sys.stderr: b35.
Call print_error, or just allow the standard traceback mechanism to
work.  Then, the output will go wherever your ‘write()’ method sends it.

The easiest way to do this is to use the *note io.StringIO: 112b. class:

     >>> import io, sys
     >>> sys.stdout = io.StringIO()
     >>> print('foo')
     >>> print('hello world!')
     >>> sys.stderr.write(sys.stdout.getvalue())
     foo
     hello world!

A custom object to do the same would look like this:

     >>> import io, sys
     >>> class StdoutCatcher(io.TextIOBase):
     ...     def __init__(self):
     ...         self.data = []
     ...     def write(self, stuff):
     ...         self.data.append(stuff)
     ...
     >>> import sys
     >>> sys.stdout = StdoutCatcher()
     >>> print('foo')
     >>> print('hello world!')
     >>> sys.stderr.write(''.join(sys.stdout.data))
     foo
     hello world!


File: python.info,  Node: How do I access a module written in Python from C?,  Next: How do I interface to C++ objects from Python?,  Prev: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?,  Up: Extending/Embedding FAQ

10.5.10 How do I access a module written in Python from C?
----------------------------------------------------------

You can get a pointer to the module object as follows:

     module = PyImport_ImportModule("<modulename>");

If the module hasn’t been imported yet (i.e.  it is not yet present in
*note sys.modules: 17ce.), this initializes the module; otherwise it
simply returns the value of ‘sys.modules["<modulename>"]’.  Note that it
doesn’t enter the module into any namespace – it only ensures it has
been initialized and is stored in *note sys.modules: 17ce.

You can then access the module’s attributes (i.e.  any name defined in
the module) as follows:

     attr = PyObject_GetAttrString(module, "<attrname>");

Calling *note PyObject_SetAttrString(): 1976. to assign to variables in
the module also works.


File: python.info,  Node: How do I interface to C++ objects from Python?,  Next: I added a module using the Setup file and the make fails; why?,  Prev: How do I access a module written in Python from C?,  Up: Extending/Embedding FAQ

10.5.11 How do I interface to C++ objects from Python?
------------------------------------------------------

Depending on your requirements, there are many approaches.  To do this
manually, begin by reading *note the «Extending and Embedding» document:
1fa5.  Realize that for the Python run-time system, there isn’t a whole
lot of difference between C and C++ – so the strategy of building a new
Python type around a C structure (pointer) type will also work for C++
objects.

For C++ libraries, see *note Writing C is hard; are there any
alternatives?: 5921.


File: python.info,  Node: I added a module using the Setup file and the make fails; why?,  Next: How do I debug an extension?,  Prev: How do I interface to C++ objects from Python?,  Up: Extending/Embedding FAQ

10.5.12 I added a module using the Setup file and the make fails; why?
----------------------------------------------------------------------

Setup must end in a newline, if there is no newline there, the build
process fails.  (Fixing this requires some ugly shell script hackery,
and this bug is so minor that it doesn’t seem worth the effort.)


File: python.info,  Node: How do I debug an extension?,  Next: I want to compile a Python module on my Linux system but some files are missing Why?,  Prev: I added a module using the Setup file and the make fails; why?,  Up: Extending/Embedding FAQ

10.5.13 How do I debug an extension?
------------------------------------

When using GDB with dynamically loaded extensions, you can’t set a
breakpoint in your extension until your extension is loaded.

In your ‘.gdbinit’ file (or interactively), add the command:

     br _PyImport_LoadDynamicModule

Then, when you run GDB:

     $ gdb /local/bin/python
     gdb) run myscript.py
     gdb) continue # repeat until your extension is loaded
     gdb) finish   # so that your extension is loaded
     gdb) br myfunction.c:50
     gdb) continue


File: python.info,  Node: I want to compile a Python module on my Linux system but some files are missing Why?,  Next: How do I tell «incomplete input» from «invalid input»?,  Prev: How do I debug an extension?,  Up: Extending/Embedding FAQ

10.5.14 I want to compile a Python module on my Linux system, but some files are missing. Why?
----------------------------------------------------------------------------------------------

Most packaged versions of Python omit some files required for compiling
Python extensions.

For Red Hat, install the python3-devel RPM to get the necessary files.

For Debian, run ‘apt-get install python3-dev’.


File: python.info,  Node: How do I tell «incomplete input» from «invalid input»?,  Next: How do I find undefined g++ symbols __builtin_new or __pure_virtual?,  Prev: I want to compile a Python module on my Linux system but some files are missing Why?,  Up: Extending/Embedding FAQ

10.5.15 How do I tell «incomplete input» from «invalid input»?
--------------------------------------------------------------

Sometimes you want to emulate the Python interactive interpreter’s
behavior, where it gives you a continuation prompt when the input is
incomplete (e.g.  you typed the start of an «if» statement or you didn’t
close your parentheses or triple string quotes), but it gives you a
syntax error message immediately when the input is invalid.

In Python you can use the *note codeop: 1d. module, which approximates
the parser’s behavior sufficiently.  IDLE uses this, for example.

The easiest way to do it in C is to call *note PyRun_InteractiveLoop():
51a1. (perhaps in a separate thread) and let the Python interpreter
handle the input for you.  You can also set the *note
PyOS_ReadlineFunctionPointer(): 7a6. to point at your custom input
function.  See ‘Modules/readline.c’ and ‘Parser/myreadline.c’ for more
hints.


File: python.info,  Node: How do I find undefined g++ symbols __builtin_new or __pure_virtual?,  Next: Can I create an object class with some methods implemented in C and others in Python e g through inheritance ?,  Prev: How do I tell «incomplete input» from «invalid input»?,  Up: Extending/Embedding FAQ

10.5.16 How do I find undefined g++ symbols __builtin_new or __pure_virtual?
----------------------------------------------------------------------------

To dynamically load g++ extension modules, you must recompile Python,
relink it using g++ (change LINKCC in the Python Modules Makefile), and
link your extension module using g++ (e.g., ‘g++ -shared -o mymodule.so
mymodule.o’).


File: python.info,  Node: Can I create an object class with some methods implemented in C and others in Python e g through inheritance ?,  Prev: How do I find undefined g++ symbols __builtin_new or __pure_virtual?,  Up: Extending/Embedding FAQ

10.5.17 Can I create an object class with some methods implemented in C and others in Python (e.g. through inheritance)?
------------------------------------------------------------------------------------------------------------------------

Yes, you can inherit from built-in classes such as *note int: 19b, *note
list: 24d, *note dict: 183, etc.

The Boost Python Library (BPL,
‘https://www.boost.org/libs/python/doc/index.html’) provides a way of
doing this from C++ (i.e.  you can inherit from an extension class
written in C++ using the BPL).


File: python.info,  Node: Python on Windows FAQ,  Next: Graphic User Interface FAQ,  Prev: Extending/Embedding FAQ,  Up: Python Frequently Asked Questions

10.6 Python on Windows FAQ
==========================

* Menu:

* How do I run a Python program under Windows?::
* How do I make Python scripts executable?::
* Why does Python sometimes take so long to start?::
* How do I make an executable from a Python script?::
* Is a *.pyd file the same as a DLL?: Is a * pyd file the same as a DLL?.
* How can I embed Python into a Windows application?::
* How do I keep editors from inserting tabs into my Python source?::
* How do I check for a keypress without blocking?::
* How do I solve the missing api-ms-win-crt-runtime-l1-1-0.dll error?: How do I solve the missing api-ms-win-crt-runtime-l1-1-0 dll error?.


File: python.info,  Node: How do I run a Python program under Windows?,  Next: How do I make Python scripts executable?,  Up: Python on Windows FAQ

10.6.1 How do I run a Python program under Windows?
---------------------------------------------------

This is not necessarily a straightforward question.  If you are already
familiar with running programs from the Windows command line then
everything will seem obvious; otherwise, you might need a little more
guidance.

Unless you use some sort of integrated development environment, you will
end up 'typing' Windows commands into what is referred to as a «Command
prompt window».  Usually you can create such a window from your search
bar by searching for ‘cmd’.  You should be able to recognize when you
have started such a window because you will see a Windows «command
prompt», which usually looks like this:

     C:\>

The letter may be different, and there might be other things after it,
so you might just as easily see something like:

     D:\YourName\Projects\Python>

depending on how your computer has been set up and what else you have
recently done with it.  Once you have started such a window, you are
well on the way to running Python programs.

You need to realize that your Python scripts have to be processed by
another program called the Python 'interpreter'.  The interpreter reads
your script, compiles it into bytecodes, and then executes the bytecodes
to run your program.  So, how do you arrange for the interpreter to
handle your Python?

First, you need to make sure that your command window recognises the
word «py» as an instruction to start the interpreter.  If you have
opened a command window, you should try entering the command ‘py’ and
hitting return:

     C:\Users\YourName> py

You should then see something like:

     Python 3.6.4 (v3.6.4:d48eceb, Dec 19 2017, 06:04:45) [MSC v.1900 32 bit (Intel)] on win32
     Type "help", "copyright", "credits" or "license" for more information.
     >>>

You have started the interpreter in «interactive mode».  That means you
can enter Python statements or expressions interactively and have them
executed or evaluated while you wait.  This is one of Python’s strongest
features.  Check it by entering a few expressions of your choice and
seeing the results:

     >>> print("Hello")
     Hello
     >>> "Hello" * 3
     'HelloHelloHello'

Many people use the interactive mode as a convenient yet highly
programmable calculator.  When you want to end your interactive Python
session, call the *note exit(): 25c6. function or hold the ‘Ctrl’ key
down while you enter a ‘Z’, then hit the «‘Enter’» key to get back to
your Windows command prompt.

You may also find that you have a Start-menu entry such as Start ‣
Programs ‣ Python 3.x ‣ Python (command line) that results in you seeing
the ‘>>>’ prompt in a new window.  If so, the window will disappear
after you call the *note exit(): 25c6. function or enter the ‘Ctrl’-‘Z’
character; Windows is running a single «python» command in the window,
and closes it when you terminate the interpreter.

Now that we know the ‘py’ command is recognized, you can give your
Python script to it.  You’ll have to give either an absolute or a
relative path to the Python script.  Let’s say your Python script is
located in your desktop and is named ‘hello.py’, and your command prompt
is nicely opened in your home directory so you’re seeing something
similar to:

     C:\Users\YourName>

So now you’ll ask the ‘py’ command to give your script to Python by
typing ‘py’ followed by your script path:

     C:\Users\YourName> py Desktop\hello.py
     hello


File: python.info,  Node: How do I make Python scripts executable?,  Next: Why does Python sometimes take so long to start?,  Prev: How do I run a Python program under Windows?,  Up: Python on Windows FAQ

10.6.2 How do I make Python scripts executable?
-----------------------------------------------

On Windows, the standard Python installer already associates the .py
extension with a file type (Python.File) and gives that file type an
open command that runs the interpreter (‘D:\Program
Files\Python\python.exe "%1" %*’).  This is enough to make scripts
executable from the command prompt as “foo.py”.  If you’d rather be able
to execute the script by simple typing “foo” with no extension you need
to add .py to the PATHEXT environment variable.


File: python.info,  Node: Why does Python sometimes take so long to start?,  Next: How do I make an executable from a Python script?,  Prev: How do I make Python scripts executable?,  Up: Python on Windows FAQ

10.6.3 Why does Python sometimes take so long to start?
-------------------------------------------------------

Usually Python starts very quickly on Windows, but occasionally there
are bug reports that Python suddenly begins to take a long time to start
up.  This is made even more puzzling because Python will work fine on
other Windows systems which appear to be configured identically.

The problem may be caused by a misconfiguration of virus checking
software on the problem machine.  Some virus scanners have been known to
introduce startup overhead of two orders of magnitude when the scanner
is configured to monitor all reads from the filesystem.  Try checking
the configuration of virus scanning software on your systems to ensure
that they are indeed configured identically.  McAfee, when configured to
scan all file system read activity, is a particular offender.


File: python.info,  Node: How do I make an executable from a Python script?,  Next: Is a * pyd file the same as a DLL?,  Prev: Why does Python sometimes take so long to start?,  Up: Python on Windows FAQ

10.6.4 How do I make an executable from a Python script?
--------------------------------------------------------

See *note How can I create a stand-alone binary from a Python script?:
588d. for a list of tools that can be used to make executables.


File: python.info,  Node: Is a * pyd file the same as a DLL?,  Next: How can I embed Python into a Windows application?,  Prev: How do I make an executable from a Python script?,  Up: Python on Windows FAQ

10.6.5 Is a ‘*.pyd’ file the same as a DLL?
-------------------------------------------

Yes, .pyd files are dll’s, but there are a few differences.  If you have
a DLL named ‘foo.pyd’, then it must have a function ‘PyInit_foo()’.  You
can then write Python «import foo», and Python will search for foo.pyd
(as well as foo.py, foo.pyc) and if it finds it, will attempt to call
‘PyInit_foo()’ to initialize it.  You do not link your .exe with
foo.lib, as that would cause Windows to require the DLL to be present.

Note that the search path for foo.pyd is PYTHONPATH, not the same as the
path that Windows uses to search for foo.dll.  Also, foo.pyd need not be
present to run your program, whereas if you linked your program with a
dll, the dll is required.  Of course, foo.pyd is required if you want to
say ‘import foo’.  In a DLL, linkage is declared in the source code with
‘__declspec(dllexport)’.  In a .pyd, linkage is defined in a list of
available functions.


File: python.info,  Node: How can I embed Python into a Windows application?,  Next: How do I keep editors from inserting tabs into my Python source?,  Prev: Is a * pyd file the same as a DLL?,  Up: Python on Windows FAQ

10.6.6 How can I embed Python into a Windows application?
---------------------------------------------------------

Embedding the Python interpreter in a Windows app can be summarized as
follows:

  1. Do 'not' build Python into your .exe file directly.  On Windows,
     Python must be a DLL to handle importing modules that are
     themselves DLL’s.  (This is the first key undocumented fact.)
     Instead, link to ‘python`NN'.dll’; it is typically installed in
     ‘C:\Windows\System’.  'NN' is the Python version, a number such as
     «33» for Python 3.3.

     You can link to Python in two different ways.  Load-time linking
     means linking against ‘python`NN'.lib’, while run-time linking
     means linking against ‘python`NN'.dll’.  (General note:
     ‘python`NN'.lib’ is the so-called «import lib» corresponding to
     ‘python`NN'.dll’.  It merely defines symbols for the linker.)

     Run-time linking greatly simplifies link options; everything
     happens at run time.  Your code must load ‘python`NN'.dll’ using
     the Windows ‘LoadLibraryEx()’ routine.  The code must also use
     access routines and data in ‘python`NN'.dll’ (that is, Python’s C
     API’s) using pointers obtained by the Windows ‘GetProcAddress()’
     routine.  Macros can make using these pointers transparent to any C
     code that calls routines in Python’s C API.

  2. If you use SWIG, it is easy to create a Python «extension module»
     that will make the app’s data and methods available to Python.
     SWIG will handle just about all the grungy details for you.  The
     result is C code that you link 'into' your .exe file (!)  You do
     'not' have to create a DLL file, and this also simplifies linking.

  3. SWIG will create an init function (a C function) whose name depends
     on the name of the extension module.  For example, if the name of
     the module is leo, the init function will be called initleo().  If
     you use SWIG shadow classes, as you should, the init function will
     be called initleoc().  This initializes a mostly hidden helper
     class used by the shadow class.

     The reason you can link the C code in step 2 into your .exe file is
     that calling the initialization function is equivalent to importing
     the module into Python!  (This is the second key undocumented
     fact.)

  4. In short, you can use the following code to initialize the Python
     interpreter with your extension module.

          #include <Python.h>
          ...
          Py_Initialize();  // Initialize Python.
          initmyAppc();  // Initialize (import) the helper class.
          PyRun_SimpleString("import myApp");  // Import the shadow class.

  5. There are two problems with Python’s C API which will become
     apparent if you use a compiler other than MSVC, the compiler used
     to build pythonNN.dll.

     Problem 1: The so-called «Very High Level» functions that take
     ‘FILE *’ arguments will not work in a multi-compiler environment
     because each compiler’s notion of a ‘struct FILE’ will be
     different.  From an implementation standpoint these are very low
     level functions.

     Problem 2: SWIG generates the following code when generating
     wrappers to void functions:

          Py_INCREF(Py_None);
          _resultobj = Py_None;
          return _resultobj;

     Alas, Py_None is a macro that expands to a reference to a complex
     data structure called _Py_NoneStruct inside pythonNN.dll.  Again,
     this code will fail in a mult-compiler environment.  Replace such
     code by:

          return Py_BuildValue("");

     It may be possible to use SWIG’s ‘%typemap’ command to make the
     change automatically, though I have not been able to get this to
     work (I’m a complete SWIG newbie).

  6. Using a Python shell script to put up a Python interpreter window
     from inside your Windows app is not a good idea; the resulting
     window will be independent of your app’s windowing system.  Rather,
     you (or the wxPythonWindow class) should create a «native»
     interpreter window.  It is easy to connect that window to the
     Python interpreter.  You can redirect Python’s i/o to _any_ object
     that supports read and write, so all you need is a Python object
     (defined in your extension module) that contains read() and write()
     methods.


File: python.info,  Node: How do I keep editors from inserting tabs into my Python source?,  Next: How do I check for a keypress without blocking?,  Prev: How can I embed Python into a Windows application?,  Up: Python on Windows FAQ

10.6.7 How do I keep editors from inserting tabs into my Python source?
-----------------------------------------------------------------------

The FAQ does not recommend using tabs, and the Python style guide, PEP
8(1), recommends 4 spaces for distributed Python code; this is also the
Emacs python-mode default.

Under any editor, mixing tabs and spaces is a bad idea.  MSVC is no
different in this respect, and is easily configured to use spaces: Take
Tools ‣ Options ‣ Tabs, and for file type «Default» set «Tab size» and
«Indent size» to 4, and select the «Insert spaces» radio button.

Python raises *note IndentationError: 9ad. or *note TabError: 766. if
mixed tabs and spaces are causing problems in leading whitespace.  You
may also run the *note tabnanny: e3. module to check a directory tree in
batch mode.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0008/


File: python.info,  Node: How do I check for a keypress without blocking?,  Next: How do I solve the missing api-ms-win-crt-runtime-l1-1-0 dll error?,  Prev: How do I keep editors from inserting tabs into my Python source?,  Up: Python on Windows FAQ

10.6.8 How do I check for a keypress without blocking?
------------------------------------------------------

Use the *note msvcrt: 97. module.  This is a standard Windows-specific
extension module.  It defines a function ‘kbhit()’ which checks whether
a keyboard hit is present, and ‘getch()’ which gets one character
without echoing it.


File: python.info,  Node: How do I solve the missing api-ms-win-crt-runtime-l1-1-0 dll error?,  Prev: How do I check for a keypress without blocking?,  Up: Python on Windows FAQ

10.6.9 How do I solve the missing api-ms-win-crt-runtime-l1-1-0.dll error?
--------------------------------------------------------------------------

This can occur on Python 3.5 and later when using Windows 8.1 or earlier
without all updates having been installed.  First ensure your operating
system is supported and is up to date, and if that does not resolve the
issue, visit the Microsoft support page(1) for guidance on manually
installing the C Runtime update.

   ---------- Footnotes ----------

   (1) https://support.microsoft.com/en-us/help/3118401/


File: python.info,  Node: Graphic User Interface FAQ,  Next: «Why is Python Installed on my Computer?» FAQ,  Prev: Python on Windows FAQ,  Up: Python Frequently Asked Questions

10.7 Graphic User Interface FAQ
===============================

* Menu:

* General GUI Questions::
* What GUI toolkits exist for Python?::
* Tkinter questions::


File: python.info,  Node: General GUI Questions,  Next: What GUI toolkits exist for Python?,  Up: Graphic User Interface FAQ

10.7.1 General GUI Questions
----------------------------


File: python.info,  Node: What GUI toolkits exist for Python?,  Next: Tkinter questions,  Prev: General GUI Questions,  Up: Graphic User Interface FAQ

10.7.2 What GUI toolkits exist for Python?
------------------------------------------

Standard builds of Python include an object-oriented interface to the
Tcl/Tk widget set, called *note tkinter: 42c8.  This is probably the
easiest to install (since it comes included with most binary
distributions(1) of Python) and use.  For more info about Tk, including
pointers to the source, see the Tcl/Tk home page(2).  Tcl/Tk is fully
portable to the macOS, Windows, and Unix platforms.

Depending on what platform(s) you are aiming at, there are also several
alternatives.  A list of cross-platform(3) and platform-specific(4) GUI
frameworks can be found on the python wiki.

   ---------- Footnotes ----------

   (1) https://www.python.org/downloads/

   (2) https://www.tcl.tk

   (3) 
https://wiki.python.org/moin/GuiProgramming#Cross-Platform_Frameworks

   (4) 
https://wiki.python.org/moin/GuiProgramming#Platform-specific_Frameworks


File: python.info,  Node: Tkinter questions,  Prev: What GUI toolkits exist for Python?,  Up: Graphic User Interface FAQ

10.7.3 Tkinter questions
------------------------

* Menu:

* How do I freeze Tkinter applications?::
* Can I have Tk events handled while waiting for I/O?::
* I can’t get key bindings to work in Tkinter; why?: I can’t get key bindings to work in Tkinter why?.


File: python.info,  Node: How do I freeze Tkinter applications?,  Next: Can I have Tk events handled while waiting for I/O?,  Up: Tkinter questions

10.7.3.1 How do I freeze Tkinter applications?
..............................................

Freeze is a tool to create stand-alone applications.  When freezing
Tkinter applications, the applications will not be truly stand-alone, as
the application will still need the Tcl and Tk libraries.

One solution is to ship the application with the Tcl and Tk libraries,
and point to them at run-time using the ‘TCL_LIBRARY’ and ‘TK_LIBRARY’
environment variables.

Various third-party freeze libraries such as py2exe and cx_Freeze have
handling for Tkinter applications built-in.


File: python.info,  Node: Can I have Tk events handled while waiting for I/O?,  Next: I can’t get key bindings to work in Tkinter why?,  Prev: How do I freeze Tkinter applications?,  Up: Tkinter questions

10.7.3.2 Can I have Tk events handled while waiting for I/O?
............................................................

On platforms other than Windows, yes, and you don’t even need threads!
But you’ll have to restructure your I/O code a bit.  Tk has the
equivalent of Xt’s ‘XtAddInput()’ call, which allows you to register a
callback function which will be called from the Tk mainloop when I/O is
possible on a file descriptor.  See *note File Handlers: 42e6.


File: python.info,  Node: I can’t get key bindings to work in Tkinter why?,  Prev: Can I have Tk events handled while waiting for I/O?,  Up: Tkinter questions

10.7.3.3 I can’t get key bindings to work in Tkinter: why?
..........................................................

An often-heard complaint is that event handlers *note bound: 42e1. to
events with the ‘bind()’ method don’t get handled even when the
appropriate key is pressed.

The most common cause is that the widget to which the binding applies
doesn’t have «keyboard focus».  Check out the Tk documentation for the
focus command.  Usually a widget is given the keyboard focus by clicking
in it (but not for labels; see the takefocus option).


File: python.info,  Node: «Why is Python Installed on my Computer?» FAQ,  Prev: Graphic User Interface FAQ,  Up: Python Frequently Asked Questions

10.8 «Why is Python Installed on my Computer?» FAQ
==================================================

* Menu:

* What is Python?: What is Python?<2>.
* Why is Python installed on my machine?::
* Can I delete Python?::


File: python.info,  Node: What is Python?<2>,  Next: Why is Python installed on my machine?,  Up: «Why is Python Installed on my Computer?» FAQ

10.8.1 What is Python?
----------------------

Python is a programming language.  It’s used for many different
applications.  It’s used in some high schools and colleges as an
introductory programming language because Python is easy to learn, but
it’s also used by professional software developers at places such as
Google, NASA, and Lucasfilm Ltd.

If you wish to learn more about Python, start with the Beginner's Guide
to Python(1).

   ---------- Footnotes ----------

   (1) https://wiki.python.org/moin/BeginnersGuide


File: python.info,  Node: Why is Python installed on my machine?,  Next: Can I delete Python?,  Prev: What is Python?<2>,  Up: «Why is Python Installed on my Computer?» FAQ

10.8.2 Why is Python installed on my machine?
---------------------------------------------

If you find Python installed on your system but don’t remember
installing it, there are several possible ways it could have gotten
there.

   * Perhaps another user on the computer wanted to learn programming
     and installed it; you’ll have to figure out who’s been using the
     machine and might have installed it.

   * A third-party application installed on the machine might have been
     written in Python and included a Python installation.  There are
     many such applications, from GUI programs to network servers and
     administrative scripts.

   * Some Windows machines also have Python installed.  At this writing
     we’re aware of computers from Hewlett-Packard and Compaq that
     include Python.  Apparently some of HP/Compaq’s administrative
     tools are written in Python.

   * Many Unix-compatible operating systems, such as macOS and some
     Linux distributions, have Python installed by default; it’s
     included in the base installation.


File: python.info,  Node: Can I delete Python?,  Prev: Why is Python installed on my machine?,  Up: «Why is Python Installed on my Computer?» FAQ

10.8.3 Can I delete Python?
---------------------------

That depends on where Python came from.

If someone installed it deliberately, you can remove it without hurting
anything.  On Windows, use the Add/Remove Programs icon in the Control
Panel.

If Python was installed by a third-party application, you can also
remove it, but that application will no longer work.  You should use
that application’s uninstaller rather than removing Python directly.

If Python came with your operating system, removing it is not
recommended.  If you remove it, whatever tools were written in Python
will no longer run, and some of them might be important to you.
Reinstalling the whole system would then be required to fix things
again.


File: python.info,  Node: Deprecations,  Next: Glossary,  Prev: Python Frequently Asked Questions,  Up: Top

11 Deprecations
***************

* Menu:

* Pending removal in Python 3.15: Pending removal in Python 3 15<7>.
* Pending removal in Python 3.16: Pending removal in Python 3 16<7>.
* Pending removal in Python 3.17: Pending removal in Python 3 17<4>.
* Pending removal in Python 3.18: Pending removal in Python 3 18<5>.
* Pending removal in Python 3.19: Pending removal in Python 3 19<3>.
* Pending removal in future versions: Pending removal in future versions<7>.
* C API deprecations::


File: python.info,  Node: Pending removal in Python 3 15<7>,  Next: Pending removal in Python 3 16<7>,  Up: Deprecations

11.1 Pending removal in Python 3.15
===================================

   * The import system:

        * Setting *note __cached__: 321. on a module while failing to
          set *note __spec__.cached: 322. is deprecated.  In Python
          3.15, ‘__cached__’ will cease to be set or take into
          consideration by the import system or standard library.
          (gh-97879(1))

        * Setting *note __package__: 323. on a module while failing to
          set *note __spec__.parent: 324. is deprecated.  In Python
          3.15, ‘__package__’ will cease to be set or take into
          consideration by the import system or standard library.
          (gh-97879(2))

   * *note ctypes: 2e.:

        * The undocumented ‘ctypes.SetPointerType()’ function has been
          deprecated since Python 3.13.

   * *note http.server: 76.:

        * The obsolete and rarely used *note CGIHTTPRequestHandler: 325.
          has been deprecated since Python 3.13.  No direct replacement
          exists.  'Anything' is better than CGI to interface a web
          server with a request handler.

        * The ‘--cgi’ flag to the ‘python -m http.server’ command-line
          interface has been deprecated since Python 3.13.

   * *note importlib: 7b.:

        * ‘load_module()’ method: use ‘exec_module()’ instead.

   * *note locale: 8a.:

        * The *note getdefaultlocale(): 326. function has been
          deprecated since Python 3.11.  Its removal was originally
          planned for Python 3.13 (gh-90817(3)), but has been postponed
          to Python 3.15.  Use *note getlocale(): 327, *note
          setlocale(): 328, and *note getencoding(): 329. instead.
          (Contributed by Hugo van Kemenade in gh-111187(4).)

   * *note pathlib: a8.:

        * *note PurePath.is_reserved(): 32a. has been deprecated since
          Python 3.13.  Use *note os.path.isreserved(): 32b. to detect
          reserved paths on Windows.

   * *note platform: af.:

        * *note java_ver(): 32c. has been deprecated since Python 3.13.
          This function is only useful for Jython support, has a
          confusing API, and is largely untested.

   * *note sysconfig: e1.:

        * The 'check_home' argument of *note
          sysconfig.is_python_build(): 32d. has been deprecated since
          Python 3.12.

   * *note threading: f3.:

        * *note RLock(): 32e. will take no arguments in Python 3.15.
          Passing any arguments has been deprecated since Python 3.14,
          as the Python version does not permit any arguments, but the C
          version allows any number of positional or keyword arguments,
          ignoring every argument.

   * *note types: 109.:

        * *note types.CodeType: 32f.: Accessing *note co_lnotab: 330.
          was deprecated in PEP 626(5) since 3.10 and was planned to be
          removed in 3.12, but it only got a proper *note
          DeprecationWarning: 1a3. in 3.12.  May be removed in 3.15.
          (Contributed by Nikita Sobolev in gh-101866(6).)

   * *note typing: 10a.:

        * The undocumented keyword argument syntax for creating *note
          NamedTuple: 331. classes (for example, ‘Point =
          NamedTuple("Point", x=int, y=int)’) has been deprecated since
          Python 3.13.  Use the class-based syntax or the functional
          syntax instead.

        * When using the functional syntax of *note TypedDict: 332.s,
          failing to pass a value to the 'fields' parameter (‘TD =
          TypedDict("TD")’) or passing ‘None’ (‘TD = TypedDict("TD",
          None)’) has been deprecated since Python 3.13.  Use ‘class
          TD(TypedDict): pass’ or ‘TD = TypedDict("TD", {})’ to create a
          TypedDict with zero field.

        * The *note typing.no_type_check_decorator(): 333. decorator
          function has been deprecated since Python 3.13.  After eight
          years in the *note typing: 10a. module, it has yet to be
          supported by any major type checker.

   * *note wave: 119.:

        * The *note getmark(): 334, ‘setmark()’, and *note getmarkers():
          335. methods of the *note Wave_read: 336. and *note
          Wave_write: 337. classes have been deprecated since Python
          3.13.

   * *note zipimport: 138.:

        * *note load_module(): 338. has been deprecated since Python
          3.10.  Use *note exec_module(): 339. instead.  (Contributed by
          Jiahao Li in gh-125746(7).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/97879

   (2) https://github.com/python/cpython/issues/97879

   (3) https://github.com/python/cpython/issues/90817

   (4) https://github.com/python/cpython/issues/111187

   (5) https://peps.python.org/pep-0626/

   (6) https://github.com/python/cpython/issues/101866

   (7) https://github.com/python/cpython/issues/125746


File: python.info,  Node: Pending removal in Python 3 16<7>,  Next: Pending removal in Python 3 17<4>,  Prev: Pending removal in Python 3 15<7>,  Up: Deprecations

11.2 Pending removal in Python 3.16
===================================

   * The import system:

        * Setting *note __loader__: 33b. on a module while failing to
          set *note __spec__.loader: 33c. is deprecated.  In Python
          3.16, ‘__loader__’ will cease to be set or taken into
          consideration by the import system or the standard library.

   * *note array: 8.:

        * The ‘'u'’ format code (‘wchar_t’) has been deprecated in
          documentation since Python 3.3 and at runtime since Python
          3.13.  Use the ‘'w'’ format code (*note Py_UCS4: 33d.) for
          Unicode characters instead.

   * *note asyncio: b.:

        * ‘asyncio.iscoroutinefunction()’ is deprecated and will be
          removed in Python 3.16; use *note
          inspect.iscoroutinefunction(): 30d. instead.  (Contributed by
          Jiahao Li and Kumar Aditya in gh-122875(1).)

        * *note asyncio: b. policy system is deprecated and will be
          removed in Python 3.16.  In particular, the following classes
          and functions are deprecated:

             * *note asyncio.AbstractEventLoopPolicy: 30e.

             * *note asyncio.DefaultEventLoopPolicy: 30f.

             * *note asyncio.WindowsSelectorEventLoopPolicy: 310.

             * *note asyncio.WindowsProactorEventLoopPolicy: 311.

             * *note asyncio.get_event_loop_policy(): 312.

             * *note asyncio.set_event_loop_policy(): 313.

          Users should use *note asyncio.run(): 2f3. or *note
          asyncio.Runner: 2f5. with 'loop_factory' to use the desired
          event loop implementation.

          For example, to use *note asyncio.SelectorEventLoop: 314. on
          Windows:

               import asyncio

               async def main():
                   ...

               asyncio.run(main(), loop_factory=asyncio.SelectorEventLoop)

          (Contributed by Kumar Aditya in gh-127949(2).)

   * *note builtins: 13.:

        * Bitwise inversion on boolean types, ‘~True’ or ‘~False’ has
          been deprecated since Python 3.12, as it produces surprising
          and unintuitive results (‘-2’ and ‘-1’).  Use ‘not x’ instead
          for the logical negation of a Boolean.  In the rare case that
          you need the bitwise inversion of the underlying integer,
          convert to ‘int’ explicitly (‘~int(x)’).

   * *note functools: 63.:

        * Calling the Python implementation of *note functools.reduce():
          21a. with 'function' or 'sequence' as keyword arguments has
          been deprecated since Python 3.14.

   * *note logging: 8b.:

     Support for custom logging handlers with the 'strm' argument is
     deprecated and scheduled for removal in Python 3.16.  Define
     handlers with the 'stream' argument instead.  (Contributed by
     Mariusz Felisiak in gh-115032(3).)

   * *note mimetypes: 93.:

        * Valid extensions start with a “.” or are empty for *note
          mimetypes.MimeTypes.add_type(): 319.  Undotted extensions are
          deprecated and will raise a *note ValueError: 2ec. in Python
          3.16.  (Contributed by Hugo van Kemenade in gh-75223(4).)

   * *note shutil: ca.:

        * The ‘ExecError’ exception has been deprecated since Python
          3.14.  It has not been used by any function in ‘shutil’ since
          Python 3.4, and is now an alias of *note RuntimeError: 244.

   * *note symtable: de.:

        * The *note Class.get_methods: 31d. method has been deprecated
          since Python 3.14.

   * *note sys: df.:

        * The *note _enablelegacywindowsfsencoding(): 33e. function has
          been deprecated since Python 3.13.  Use the *note
          PYTHONLEGACYWINDOWSFSENCODING: 33f. environment variable
          instead.

   * *note sysconfig: e1.:

        * The ‘sysconfig.expand_makefile_vars()’ function has been
          deprecated since Python 3.14.  Use the ‘vars’ argument of
          *note sysconfig.get_paths(): 340. instead.

   * *note tarfile: e4.:

        * The undocumented and unused ‘TarFile.tarfile’ attribute has
          been deprecated since Python 3.13.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/122875

   (2) https://github.com/python/cpython/issues/127949

   (3) https://github.com/python/cpython/issues/115032

   (4) https://github.com/python/cpython/issues/75223


File: python.info,  Node: Pending removal in Python 3 17<4>,  Next: Pending removal in Python 3 18<5>,  Prev: Pending removal in Python 3 16<7>,  Up: Deprecations

11.3 Pending removal in Python 3.17
===================================

   * *note collections.abc: 1f.:

        - *note collections.abc.ByteString: 342. is scheduled for
          removal in Python 3.17.

          Use ‘isinstance(obj, collections.abc.Buffer)’ to test if ‘obj’
          implements the *note buffer protocol: 260. at runtime.  For
          use in type annotations, either use *note Buffer: 343. or a
          union that explicitly specifies the types your code supports
          (e.g., ‘bytes | bytearray | memoryview’).

          ‘ByteString’ was originally intended to be an abstract class
          that would serve as a supertype of both *note bytes: 192. and
          *note bytearray: 344.  However, since the ABC never had any
          methods, knowing that an object was an instance of
          ‘ByteString’ never actually told you anything useful about the
          object.  Other common buffer types such as *note memoryview:
          165. were also never understood as subtypes of ‘ByteString’
          (either at runtime or by static type checkers).

          See PEP 688(1) for more details.  (Contributed by Shantanu
          Jain in gh-91896(2).)

   * *note typing: 10a.:

        - Before Python 3.14, old-style unions were implemented using
          the private class ‘typing._UnionGenericAlias’.  This class is
          no longer needed for the implementation, but it has been
          retained for backward compatibility, with removal scheduled
          for Python 3.17.  Users should use documented introspection
          helpers like *note typing.get_origin(): 2ab. and *note
          typing.get_args(): 2ac. instead of relying on private
          implementation details.

        - *note typing.ByteString: 345, deprecated since Python 3.9, is
          scheduled for removal in Python 3.17.

          Use ‘isinstance(obj, collections.abc.Buffer)’ to test if ‘obj’
          implements the *note buffer protocol: 260. at runtime.  For
          use in type annotations, either use *note Buffer: 343. or a
          union that explicitly specifies the types your code supports
          (e.g., ‘bytes | bytearray | memoryview’).

          ‘ByteString’ was originally intended to be an abstract class
          that would serve as a supertype of both *note bytes: 192. and
          *note bytearray: 344.  However, since the ABC never had any
          methods, knowing that an object was an instance of
          ‘ByteString’ never actually told you anything useful about the
          object.  Other common buffer types such as *note memoryview:
          165. were also never understood as subtypes of ‘ByteString’
          (either at runtime or by static type checkers).

          See PEP 688(3) for more details.  (Contributed by Shantanu
          Jain in gh-91896(4).)

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0688/#current-options

   (2) https://github.com/python/cpython/issues/91896

   (3) https://peps.python.org/pep-0688/#current-options

   (4) https://github.com/python/cpython/issues/91896


File: python.info,  Node: Pending removal in Python 3 18<5>,  Next: Pending removal in Python 3 19<3>,  Prev: Pending removal in Python 3 17<4>,  Up: Deprecations

11.4 Pending removal in Python 3.18
===================================

   * *note decimal: 3a.:

        * The non-standard and undocumented *note Decimal: 1fe. format
          specifier ‘'N'’, which is only supported in the ‘decimal’
          module’s C implementation, has been deprecated since Python
          3.13.  (Contributed by Serhiy Storchaka in gh-89902(1).)

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/89902


File: python.info,  Node: Pending removal in Python 3 19<3>,  Next: Pending removal in future versions<7>,  Prev: Pending removal in Python 3 18<5>,  Up: Deprecations

11.5 Pending removal in Python 3.19
===================================

   * *note ctypes: 2e.:

        * Implicitly switching to the MSVC-compatible struct layout by
          setting *note _pack_: 317. but not *note _layout_: 1e7. on
          non-Windows platforms.


File: python.info,  Node: Pending removal in future versions<7>,  Next: C API deprecations,  Prev: Pending removal in Python 3 19<3>,  Up: Deprecations

11.6 Pending removal in future versions
=======================================

The following APIs will be removed in the future, although there is
currently no date scheduled for their removal.

   * *note argparse: 7.:

        * Nesting argument groups and nesting mutually exclusive groups
          are deprecated.

        * Passing the undocumented keyword argument 'prefix_chars' to
          *note add_argument_group(): 2eb. is now deprecated.

        * The *note argparse.FileType: 30c. type converter is
          deprecated.

   * *note builtins: 13.:

        * Generators: ‘throw(type, exc, tb)’ and ‘athrow(type, exc, tb)’
          signature is deprecated: use ‘throw(exc)’ and ‘athrow(exc)’
          instead, the single argument signature.

        * Currently Python accepts numeric literals immediately followed
          by keywords, for example ‘0in x’, ‘1or x’, ‘0if 1else 2’.  It
          allows confusing and ambiguous expressions like ‘[0x1for x in
          y]’ (which can be interpreted as ‘[0x1 for x in y]’ or ‘[0x1f
          or x in y]’).  A syntax warning is raised if the numeric
          literal is immediately followed by one of keywords *note and:
          349, *note else: 17c, *note for: 34a, *note if: 181, *note in:
          34b, *note is: 34c. and *note or: 34d.  In a future release it
          will be changed to a syntax error.  (gh-87999(1))

        * Support for ‘__index__()’ and ‘__int__()’ method returning
          non-int type: these methods will be required to return an
          instance of a strict subclass of *note int: 19b.

        * Support for ‘__float__()’ method returning a strict subclass
          of *note float: 196.: these methods will be required to return
          an instance of *note float: 196.

        * Support for ‘__complex__()’ method returning a strict subclass
          of *note complex: 197.: these methods will be required to
          return an instance of *note complex: 197.

        * Delegation of ‘int()’ to ‘__trunc__()’ method.

        * Passing a complex number as the 'real' or 'imag' argument in
          the *note complex(): 197. constructor is now deprecated; it
          should only be passed as a single positional argument.
          (Contributed by Serhiy Storchaka in gh-109218(2).)

   * *note calendar: 15.: ‘calendar.January’ and ‘calendar.February’
     constants are deprecated and replaced by *note calendar.JANUARY:
     34e. and *note calendar.FEBRUARY: 34f.  (Contributed by Prince
     Roshan in gh-103636(3).)

   * *note codecs: 1c.: use *note open(): 316. instead of *note
     codecs.open(): 315.  (gh-133038(4))

   * *note codeobject.co_lnotab: 330.: use the *note
     codeobject.co_lines(): 350. method instead.

   * *note datetime: 34.:

        * *note utcnow(): 351.: use
          ‘datetime.datetime.now(tz=datetime.UTC)’.

        * *note utcfromtimestamp(): 352.: use
          ‘datetime.datetime.fromtimestamp(timestamp, tz=datetime.UTC)’.

   * *note gettext: 67.: Plural value must be an integer.

   * *note importlib: 7b.:

        * *note cache_from_source(): 353. 'debug_override' parameter is
          deprecated: use the 'optimization' parameter instead.

   * *note importlib.metadata: 7e.:

        * ‘EntryPoints’ tuple interface.

        * Implicit ‘None’ on return values.

   * *note logging: 8b.: the ‘warn()’ method has been deprecated since
     Python 3.3, use *note warning(): 354. instead.

   * *note mailbox: 8f.: Use of StringIO input and text mode is
     deprecated, use BytesIO and binary mode instead.

   * *note os: a5.: Calling *note os.register_at_fork(): 355. in
     multi-threaded process.

   * ‘pydoc.ErrorDuringImport’: A tuple value for 'exc_info' parameter
     is deprecated, use an exception instance.

   * *note re: be.: More strict rules are now applied for numerical
     group references and group names in regular expressions.  Only
     sequence of ASCII digits is now accepted as a numerical reference.
     The group name in bytes patterns and replacement strings can now
     only contain ASCII letters and digits and underscore.  (Contributed
     by Serhiy Storchaka in gh-91760(5).)

   * ‘sre_compile’, ‘sre_constants’ and ‘sre_parse’ modules.

   * *note shutil: ca.: *note rmtree(): 356.”s 'onerror' parameter is
     deprecated in Python 3.12; use the 'onexc' parameter instead.

   * *note ssl: d5. options and protocols:

        * *note ssl.SSLContext: 357. without protocol argument is
          deprecated.

        * *note ssl.SSLContext: 357.: *note set_npn_protocols(): 358.
          and ‘selected_npn_protocol()’ are deprecated: use ALPN
          instead.

        * ‘ssl.OP_NO_SSL*’ options

        * ‘ssl.OP_NO_TLS*’ options

        * ‘ssl.PROTOCOL_SSLv3’

        * ‘ssl.PROTOCOL_TLS’

        * ‘ssl.PROTOCOL_TLSv1’

        * ‘ssl.PROTOCOL_TLSv1_1’

        * ‘ssl.PROTOCOL_TLSv1_2’

        * ‘ssl.TLSVersion.SSLv3’

        * ‘ssl.TLSVersion.TLSv1’

        * ‘ssl.TLSVersion.TLSv1_1’

   * *note threading: f3. methods:

        * ‘threading.Condition.notifyAll()’: use *note notify_all():
          359.

        * ‘threading.Event.isSet()’: use *note is_set(): 35a.

        * ‘threading.Thread.isDaemon()’, *note
          threading.Thread.setDaemon(): 35b.: use *note
          threading.Thread.daemon: 35c. attribute.

        * ‘threading.Thread.getName()’, *note
          threading.Thread.setName(): 35d.: use *note
          threading.Thread.name: 2a0. attribute.

        * ‘threading.currentThread()’: use *note
          threading.current_thread(): 35e.

        * ‘threading.activeCount()’: use *note threading.active_count():
          35f.

   * *note typing.Text: 360. (gh-92332(6)).

   * The internal class ‘typing._UnionGenericAlias’ is no longer used to
     implement *note typing.Union: 2a8.  To preserve compatibility with
     users using this private class, a compatibility shim will be
     provided until at least Python 3.17.  (Contributed by Jelle
     Zijlstra in gh-105499(7).)

   * *note unittest.IsolatedAsyncioTestCase: 361.: it is deprecated to
     return a value that is not ‘None’ from a test case.

   * *note urllib.parse: 110. deprecated functions: *note urlparse():
     362. instead

        * ‘splitattr()’

        * ‘splithost()’

        * ‘splitnport()’

        * ‘splitpasswd()’

        * ‘splitport()’

        * ‘splitquery()’

        * ‘splittag()’

        * ‘splittype()’

        * ‘splituser()’

        * ‘splitvalue()’

        * ‘to_bytes()’

   * *note wsgiref: 11e.: ‘SimpleHandler.stdout.write()’ should not do
     partial writes.

   * *note xml.etree.ElementTree: 12b.: Testing the truth value of an
     *note Element: 363. is deprecated.  In a future release it will
     always return ‘True’.  Prefer explicit ‘len(elem)’ or ‘elem is not
     None’ tests instead.

   * *note sys._clear_type_cache(): 292. is deprecated: use *note
     sys._clear_internal_caches(): 364. instead.

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/issues/87999

   (2) https://github.com/python/cpython/issues/109218

   (3) https://github.com/python/cpython/issues/103636

   (4) https://github.com/python/cpython/issues/133038

   (5) https://github.com/python/cpython/issues/91760

   (6) https://github.com/python/cpython/issues/92332

   (7) https://github.com/python/cpython/issues/105499


File: python.info,  Node: C API deprecations,  Prev: Pending removal in future versions<7>,  Up: Deprecations

11.7 C API deprecations
=======================

* Menu:

* Pending removal in Python 3.15: Pending removal in Python 3 15<8>.
* Pending removal in Python 3.18: Pending removal in Python 3 18<6>.
* Pending removal in future versions: Pending removal in future versions<8>.


File: python.info,  Node: Pending removal in Python 3 15<8>,  Next: Pending removal in Python 3 18<6>,  Up: C API deprecations

11.7.1 Pending removal in Python 3.15
-------------------------------------

   * The *note PyImport_ImportModuleNoBlock(): 3db.: Use *note
     PyImport_ImportModule(): 3dc. instead.

   * *note PyWeakref_GetObject(): 3dd. and *note PyWeakref_GET_OBJECT():
     3de.: Use *note PyWeakref_GetRef(): 3df. instead.  The
     pythoncapi-compat project(1) can be used to get *note
     PyWeakref_GetRef(): 3df. on Python 3.12 and older.

   * *note Py_UNICODE: 3e0. type and the ‘Py_UNICODE_WIDE’ macro: Use
     ‘wchar_t’ instead.

   * ‘PyUnicode_AsDecodedObject()’: Use *note PyCodec_Decode(): 3e1.
     instead.

   * ‘PyUnicode_AsDecodedUnicode()’: Use *note PyCodec_Decode(): 3e1.
     instead; Note that some codecs (for example, «base64») may return a
     type other than *note str: 169, such as *note bytes: 192.

   * ‘PyUnicode_AsEncodedObject()’: Use *note PyCodec_Encode(): 3e2.
     instead.

   * ‘PyUnicode_AsEncodedUnicode()’: Use *note PyCodec_Encode(): 3e2.
     instead; Note that some codecs (for example, «base64») may return a
     type other than *note bytes: 192, such as *note str: 169.

   * Python initialization functions, deprecated in Python 3.13:

        * *note Py_GetPath(): 3e3.: Use *note
          PyConfig_Get("module_search_paths"): 37c. (*note sys.path:
          3e4.) instead.

        * *note Py_GetPrefix(): 3e5.: Use *note
          PyConfig_Get("base_prefix"): 37c. (*note sys.base_prefix:
          3e6.) instead.  Use *note PyConfig_Get("prefix"): 37c. (*note
          sys.prefix: 3e7.) if *note virtual environments: 3e8. need to
          be handled.

        * *note Py_GetExecPrefix(): 3e9.: Use *note
          PyConfig_Get("base_exec_prefix"): 37c. (*note
          sys.base_exec_prefix: 3ea.) instead.  Use *note
          PyConfig_Get("exec_prefix"): 37c. (*note sys.exec_prefix:
          3eb.) if *note virtual environments: 3e8. need to be handled.

        * *note Py_GetProgramFullPath(): 3ec.: Use *note
          PyConfig_Get("executable"): 37c. (*note sys.executable: 3ed.)
          instead.

        * *note Py_GetProgramName(): 3ee.: Use *note
          PyConfig_Get("executable"): 37c. (*note sys.executable: 3ed.)
          instead.

        * *note Py_GetPythonHome(): 3ef.: Use *note
          PyConfig_Get("home"): 37c. or the *note PYTHONHOME: 3f0.
          environment variable instead.

     The pythoncapi-compat project(2) can be used to get *note
     PyConfig_Get(): 37c. on Python 3.13 and older.

   * Functions to configure Python’s initialization, deprecated in
     Python 3.11:

        * ‘PySys_SetArgvEx()’: Set *note PyConfig.argv: 3f1. instead.

        * ‘PySys_SetArgv()’: Set *note PyConfig.argv: 3f1. instead.

        * ‘Py_SetProgramName()’: Set *note PyConfig.program_name: 3f2.
          instead.

        * ‘Py_SetPythonHome()’: Set *note PyConfig.home: 3f3. instead.

        * *note PySys_ResetWarnOptions(): 3f4.: Clear *note
          sys.warnoptions: 3f5. and ‘warnings.filters’ instead.

     The *note Py_InitializeFromConfig(): 3f6. API should be used with
     *note PyConfig: 3f7. instead.

   * Global configuration variables:

        * *note Py_DebugFlag: 3f8.: Use *note PyConfig.parser_debug:
          3f9. or *note PyConfig_Get("parser_debug"): 37c. instead.

        * *note Py_VerboseFlag: 3fa.: Use *note PyConfig.verbose: 3fb.
          or *note PyConfig_Get("verbose"): 37c. instead.

        * *note Py_QuietFlag: 3fc.: Use *note PyConfig.quiet: 3fd. or
          *note PyConfig_Get("quiet"): 37c. instead.

        * *note Py_InteractiveFlag: 3fe.: Use *note
          PyConfig.interactive: 3ff. or *note
          PyConfig_Get("interactive"): 37c. instead.

        * *note Py_InspectFlag: 400.: Use *note PyConfig.inspect: 401.
          or *note PyConfig_Get("inspect"): 37c. instead.

        * *note Py_OptimizeFlag: 402.: Use *note
          PyConfig.optimization_level: 403. or *note
          PyConfig_Get("optimization_level"): 37c. instead.

        * *note Py_NoSiteFlag: 404.: Use *note PyConfig.site_import:
          405. or *note PyConfig_Get("site_import"): 37c. instead.

        * *note Py_BytesWarningFlag: 406.: Use *note
          PyConfig.bytes_warning: 407. or *note
          PyConfig_Get("bytes_warning"): 37c. instead.

        * *note Py_FrozenFlag: 408.: Use *note
          PyConfig.pathconfig_warnings: 409. or *note
          PyConfig_Get("pathconfig_warnings"): 37c. instead.

        * *note Py_IgnoreEnvironmentFlag: 40a.: Use *note
          PyConfig.use_environment: 40b. or *note
          PyConfig_Get("use_environment"): 37c. instead.

        * *note Py_DontWriteBytecodeFlag: 40c.: Use *note
          PyConfig.write_bytecode: 40d. or *note
          PyConfig_Get("write_bytecode"): 37c. instead.

        * *note Py_NoUserSiteDirectory: 40e.: Use *note
          PyConfig.user_site_directory: 40f. or *note
          PyConfig_Get("user_site_directory"): 37c. instead.

        * *note Py_UnbufferedStdioFlag: 410.: Use *note
          PyConfig.buffered_stdio: 411. or *note
          PyConfig_Get("buffered_stdio"): 37c. instead.

        * *note Py_HashRandomizationFlag: 412.: Use *note
          PyConfig.use_hash_seed: 413. and *note PyConfig.hash_seed:
          414. or *note PyConfig_Get("hash_seed"): 37c. instead.

        * *note Py_IsolatedFlag: 415.: Use *note PyConfig.isolated: 416.
          or *note PyConfig_Get("isolated"): 37c. instead.

        * *note Py_LegacyWindowsFSEncodingFlag: 417.: Use *note
          PyPreConfig.legacy_windows_fs_encoding: 418. or *note
          PyConfig_Get("legacy_windows_fs_encoding"): 37c. instead.

        * *note Py_LegacyWindowsStdioFlag: 419.: Use *note
          PyConfig.legacy_windows_stdio: 41a. or *note
          PyConfig_Get("legacy_windows_stdio"): 37c. instead.

        * ‘Py_FileSystemDefaultEncoding’,
          ‘Py_HasFileSystemDefaultEncoding’: Use *note
          PyConfig.filesystem_encoding: 41b. or *note
          PyConfig_Get("filesystem_encoding"): 37c. instead.

        * ‘Py_FileSystemDefaultEncodeErrors’: Use *note
          PyConfig.filesystem_errors: 41c. or *note
          PyConfig_Get("filesystem_errors"): 37c. instead.

        * ‘Py_UTF8Mode’: Use *note PyPreConfig.utf8_mode: 41d. or *note
          PyConfig_Get("utf8_mode"): 37c. instead.  (see *note
          Py_PreInitialize(): 41e.)

     The *note Py_InitializeFromConfig(): 3f6. API should be used with
     *note PyConfig: 3f7. to set these options.  Or *note
     PyConfig_Get(): 37c. can be used to get these options at runtime.

   ---------- Footnotes ----------

   (1) https://github.com/python/pythoncapi-compat/

   (2) https://github.com/python/pythoncapi-compat/


File: python.info,  Node: Pending removal in Python 3 18<6>,  Next: Pending removal in future versions<8>,  Prev: Pending removal in Python 3 15<8>,  Up: C API deprecations

11.7.2 Pending removal in Python 3.18
-------------------------------------

   * The following private functions are deprecated and planned for
     removal in Python 3.18:

        * ‘_PyBytes_Join()’: use *note PyBytes_Join(): 383.

        * ‘_PyDict_GetItemStringWithError()’: use *note
          PyDict_GetItemStringRef(): 421.

        * ‘_PyDict_Pop()’: use *note PyDict_Pop(): 422.

        * ‘_PyLong_Sign()’: use *note PyLong_GetSign(): 39a.

        * ‘_PyLong_FromDigits()’ and ‘_PyLong_New()’: use *note
          PyLongWriter_Create(): 3aa.

        * ‘_PyThreadState_UncheckedGet()’: use *note
          PyThreadState_GetUnchecked(): 423.

        * ‘_PyUnicode_AsString()’: use *note PyUnicode_AsUTF8(): 424.

        * ‘_PyUnicodeWriter_Init()’: replace
          ‘_PyUnicodeWriter_Init(&writer)’ with *note writer =
          PyUnicodeWriter_Create(0): 3b4.

        * ‘_PyUnicodeWriter_Finish()’: replace
          ‘_PyUnicodeWriter_Finish(&writer)’ with *note
          PyUnicodeWriter_Finish(writer): 3b7.

        * ‘_PyUnicodeWriter_Dealloc()’: replace
          ‘_PyUnicodeWriter_Dealloc(&writer)’ with *note
          PyUnicodeWriter_Discard(writer): 3b6.

        * ‘_PyUnicodeWriter_WriteChar()’: replace
          ‘_PyUnicodeWriter_WriteChar(&writer, ch)’ with *note
          PyUnicodeWriter_WriteChar(writer, ch): 3ba.

        * ‘_PyUnicodeWriter_WriteStr()’: replace
          ‘_PyUnicodeWriter_WriteStr(&writer, str)’ with *note
          PyUnicodeWriter_WriteStr(writer, str): 3bc.

        * ‘_PyUnicodeWriter_WriteSubstring()’: replace
          ‘_PyUnicodeWriter_WriteSubstring(&writer, str, start, end)’
          with *note PyUnicodeWriter_WriteSubstring(writer, str, start,
          end): 3bd.

        * ‘_PyUnicodeWriter_WriteASCIIString()’: replace
          ‘_PyUnicodeWriter_WriteASCIIString(&writer, str)’ with *note
          PyUnicodeWriter_WriteASCII(writer, str): 3b9.

        * ‘_PyUnicodeWriter_WriteLatin1String()’: replace
          ‘_PyUnicodeWriter_WriteLatin1String(&writer, str)’ with *note
          PyUnicodeWriter_WriteUTF8(writer, str): 3bf.

        * ‘_PyUnicodeWriter_Prepare()’: (no replacement).

        * ‘_PyUnicodeWriter_PrepareKind()’: (no replacement).

        * ‘_Py_HashPointer()’: use *note Py_HashPointer(): 425.

        * ‘_Py_fopen_obj()’: use *note Py_fopen(): 393.

     The pythoncapi-compat project(1) can be used to get these new
     public functions on Python 3.13 and older.  (Contributed by Victor
     Stinner in gh-128863(2).)

   ---------- Footnotes ----------

   (1) https://github.com/python/pythoncapi-compat/

   (2) https://github.com/python/cpython/issues/128863


File: python.info,  Node: Pending removal in future versions<8>,  Prev: Pending removal in Python 3 18<6>,  Up: C API deprecations

11.7.3 Pending removal in future versions
-----------------------------------------

The following APIs are deprecated and will be removed, although there is
currently no date scheduled for their removal.

   * *note Py_TPFLAGS_HAVE_FINALIZE: 427.: Unneeded since Python 3.8.

   * *note PyErr_Fetch(): 428.: Use *note PyErr_GetRaisedException():
     429. instead.

   * *note PyErr_NormalizeException(): 42a.: Use *note
     PyErr_GetRaisedException(): 429. instead.

   * *note PyErr_Restore(): 42b.: Use *note PyErr_SetRaisedException():
     42c. instead.

   * *note PyModule_GetFilename(): 42d.: Use *note
     PyModule_GetFilenameObject(): 42e. instead.

   * *note PyOS_AfterFork(): 42f.: Use *note PyOS_AfterFork_Child():
     430. instead.

   * *note PySlice_GetIndicesEx(): 431.: Use *note PySlice_Unpack():
     432. and *note PySlice_AdjustIndices(): 433. instead.

   * *note PyUnicode_READY(): 434.: Unneeded since Python 3.12

   * ‘PyErr_Display()’: Use *note PyErr_DisplayException(): 435.
     instead.

   * ‘_PyErr_ChainExceptions()’: Use ‘_PyErr_ChainExceptions1()’
     instead.

   * ‘PyBytesObject.ob_shash’ member: call *note PyObject_Hash(): 436.
     instead.

   * Thread Local Storage (TLS) API:

        * *note PyThread_create_key(): 437.: Use *note
          PyThread_tss_alloc(): 438. instead.

        * *note PyThread_delete_key(): 439.: Use *note
          PyThread_tss_free(): 43a. instead.

        * *note PyThread_set_key_value(): 43b.: Use *note
          PyThread_tss_set(): 43c. instead.

        * *note PyThread_get_key_value(): 43d.: Use *note
          PyThread_tss_get(): 43e. instead.

        * *note PyThread_delete_key_value(): 43f.: Use *note
          PyThread_tss_delete(): 440. instead.

        * *note PyThread_ReInitTLS(): 441.: Unneeded since Python 3.7.


File: python.info,  Node: Glossary,  Next: About this documentation,  Prev: Deprecations,  Up: Top

12 Glossary
***********

‘>>>’

     The default Python prompt of the *note interactive: 1b5. shell.
     Often seen for code examples which can be executed interactively in
     the interpreter.

‘...’

     Can refer to:

        * The default Python prompt of the *note interactive: 1b5. shell
          when entering the code for an indented code block, when within
          a pair of matching left and right delimiters (parentheses,
          square brackets, curly braces or triple quotes), or after
          specifying a decorator.

        * The three dots form of the *note Ellipsis: 1fe6. object.

abstract base class

     Abstract base classes complement *note duck-typing: 595e. by
     providing a way to define interfaces when other techniques like
     *note hasattr(): 6fa. would be clumsy or subtly wrong (for example
     with *note magic methods: 2397.).  ABCs introduce virtual
     subclasses, which are classes that don’t inherit from a class but
     are still recognized by *note isinstance(): 2ad. and *note
     issubclass(): 9c6.; see the *note abc: 4. module documentation.
     Python comes with many built-in ABCs for data structures (in the
     *note collections.abc: 1f. module), numbers (in the *note numbers:
     a2. module), streams (in the *note io: 83. module), import finders
     and loaders (in the *note importlib.abc: 7c. module).  You can
     create your own ABCs with the *note abc: 4. module.

annotate function

     A function that can be called to retrieve the *note annotations:
     15c. of an object.  This function is accessible as the *note
     __annotate__: 196b. attribute of functions, classes, and modules.
     Annotate functions are a subset of *note evaluate functions: 44d6.

annotation

     A label associated with a variable, a class attribute or a function
     parameter or return value, used by convention as a *note type hint:
     23b1.

     Annotations of local variables cannot be accessed at runtime, but
     annotations of global variables, class attributes, and functions
     can be retrieved by calling *note annotationlib.get_annotations():
     459. on modules, classes, and functions, respectively.

     See *note variable annotation: f53, *note function annotation:
     2003, PEP 484(1), PEP 526(2), and PEP 649(3), which describe this
     functionality.  Also see *note Annotations Best Practices: 9db. for
     best practices on working with annotations.

argument

     A value passed to a *note function: 2491. (or *note method: 184c.)
     when calling the function.  There are two kinds of argument:

        * 'keyword argument': an argument preceded by an identifier
          (e.g.  ‘name=’) in a function call or passed as a value in a
          dictionary preceded by ‘**’.  For example, ‘3’ and ‘5’ are
          both keyword arguments in the following calls to *note
          complex(): 197.:

               complex(real=3, imag=5)
               complex(**{'real': 3, 'imag': 5})

        * 'positional argument': an argument that is not a keyword
          argument.  Positional arguments can appear at the beginning of
          an argument list and/or be passed as elements of an *note
          iterable: 142f. preceded by ‘*’.  For example, ‘3’ and ‘5’ are
          both positional arguments in the following calls:

               complex(3, 5)
               complex(*(3, 5))

     Arguments are assigned to the named local variables in a function
     body.  See the *note Calls: f7f. section for the rules governing
     this assignment.  Syntactically, any expression can be used to
     represent an argument; the evaluated value is assigned to the local
     variable.

     See also the *note parameter: 2332. glossary entry, the FAQ
     question on *note the difference between arguments and parameters:
     5898, and PEP 362(4).

asynchronous context manager

     An object which controls the environment seen in an *note async
     with: 185. statement by defining *note __aenter__(): 2401. and
     *note __aexit__(): 1989. methods.  Introduced by PEP 492(5).

asynchronous generator

     A function which returns an *note asynchronous generator iterator:
     4900.  It looks like a coroutine function defined with *note async
     def: 7ee. except that it contains *note yield: bc4. expressions for
     producing a series of values usable in an *note async for: ca3.
     loop.

     Usually refers to an asynchronous generator function, but may refer
     to an 'asynchronous generator iterator' in some contexts.  In cases
     where the intended meaning isn’t clear, using the full terms avoids
     ambiguity.

     An asynchronous generator function may contain *note await: 18d.
     expressions as well as *note async for: ca3, and *note async with:
     185. statements.

asynchronous generator iterator

     An object created by an *note asynchronous generator: 2476.
     function.

     This is an *note asynchronous iterator: 4c8. which when called
     using the *note __anext__(): 186a. method returns an awaitable
     object which will execute the body of the asynchronous generator
     function until the next *note yield: bc4. expression.

     Each *note yield: bc4. temporarily suspends processing, remembering
     the execution state (including local variables and pending
     try-statements).  When the 'asynchronous generator iterator'
     effectively resumes with another awaitable returned by *note
     __anext__(): 186a, it picks up where it left off.  See PEP 492(6)
     and PEP 525(7).

asynchronous iterable

     An object, that can be used in an *note async for: ca3. statement.
     Must return an *note asynchronous iterator: 4c8. from its *note
     __aiter__(): df8. method.  Introduced by PEP 492(8).

asynchronous iterator

     An object that implements the *note __aiter__(): df8. and *note
     __anext__(): 186a. methods.  *note __anext__(): 186a. must return
     an *note awaitable: 4ca. object.  *note async for: ca3. resolves
     the awaitables returned by an asynchronous iterator’s *note
     __anext__(): 186a. method until it raises a *note
     StopAsyncIteration: 1df7. exception.  Introduced by PEP 492(9).

atomic operation

     An operation that appears to execute as a single, indivisible step:
     no other thread can observe it half-done, and its effects become
     visible all at once.  Python does not guarantee that high-level
     statements are atomic (for example, ‘x += 1’ performs multiple
     bytecode operations and is not atomic).  Atomicity is only
     guaranteed where explicitly documented.  See also *note race
     condition: 595f. and *note data race: 5960.

attached thread state

     A *note thread state: 182e. that is active for the current OS
     thread.

     When a *note thread state: 182e. is attached, the OS thread has
     access to the full Python C API and can safely invoke the bytecode
     interpreter.

     Unless a function explicitly notes otherwise, attempting to call
     the C API without an attached thread state will result in a fatal
     error or undefined behavior.  A thread state can be attached and
     detached explicitly by the user through the C API, or implicitly by
     the runtime, including during blocking C calls and by the bytecode
     interpreter in between calls.

     On most builds of Python, having an attached thread state implies
     that the caller holds the *note GIL: 164. for the current
     interpreter, so only one OS thread can have an attached thread
     state at a given moment.  In *note free-threaded: 1f4. builds of
     Python, threads can concurrently hold an attached thread state,
     allowing for true parallelism of the bytecode interpreter.

attribute

     A value associated with an object which is usually referenced by
     name using dotted expressions.  For example, if an object 'o' has
     an attribute 'a' it would be referenced as 'o.a'.

     It is possible to give an object an attribute whose name is not an
     identifier as defined by *note Names (identifiers and keywords):
     2289, for example using *note setattr(): 259a, if the object allows
     it.  Such an attribute will not be accessible using a dotted
     expression, and would instead need to be retrieved with *note
     getattr(): dcc.

awaitable

     An object that can be used in an *note await: 18d. expression.  Can
     be a *note coroutine: 6ba. or an object with an *note __await__():
     f77. method.  See also PEP 492(10).

BDFL

     Benevolent Dictator For Life, a.k.a.  Guido van Rossum(11),
     Python’s creator.

binary file

     A *note file object: 13cb. able to read and write *note bytes-like
     objects: 193.  Examples of binary files are files opened in binary
     mode (‘'rb'’, ‘'wb'’ or ‘'rb+'’), *note sys.stdin.buffer: 760,
     *note sys.stdout.buffer: ccf, and instances of *note io.BytesIO:
     10a6. and *note gzip.GzipFile: 65c.

     See also *note text file: 2057. for a file object able to read and
     write *note str: 169. objects.

borrowed reference

     In Python’s C API, a borrowed reference is a reference to an
     object, where the code using the object does not own the reference.
     It becomes a dangling pointer if the object is destroyed.  For
     example, a garbage collection can remove the last *note strong
     reference: 5e2. to the object and so destroy it.

     Calling *note Py_INCREF(): 790. on the *note borrowed reference:
     3d7. is recommended to convert it to a *note strong reference: 5e2.
     in-place, except when the object cannot be destroyed before the
     last usage of the borrowed reference.  The *note Py_NewRef(): a9c.
     function can be used to create a new *note strong reference: 5e2.

bytes-like object

     An object that supports the *note Buffer Protocol: 260. and can
     export a C-*note contiguous: 2669. buffer.  This includes all *note
     bytes: 192, *note bytearray: 344, and *note array.array: 4bf.
     objects, as well as many common *note memoryview: 165. objects.
     Bytes-like objects can be used for various operations that work
     with binary data; these include compression, saving to a binary
     file, and sending over a socket.

     Some operations need the binary data to be mutable.  The
     documentation often refers to these as «read-write bytes-like
     objects».  Example mutable buffer objects include *note bytearray:
     344. and a *note memoryview: 165. of a *note bytearray: 344.  Other
     operations require the binary data to be stored in immutable
     objects («read-only bytes-like objects»); examples of these include
     *note bytes: 192. and a *note memoryview: 165. of a *note bytes:
     192. object.

bytecode

     Python source code is compiled into bytecode, the internal
     representation of a Python program in the CPython interpreter.  The
     bytecode is also cached in ‘.pyc’ files so that executing the same
     file is faster the second time (recompilation from source to
     bytecode can be avoided).  This «intermediate language» is said to
     run on a *note virtual machine: 3a41. that executes the machine
     code corresponding to each bytecode.  Do note that bytecodes are
     not expected to work between different Python virtual machines, nor
     to be stable between Python releases.

     A list of bytecode instructions can be found in the documentation
     for *note the dis module: 7d0.

callable

     A callable is an object that can be called, possibly with a set of
     arguments (see *note argument: 67b.), with the following syntax:

          callable(argument1, argument2, argumentN)

     A *note function: 2491, and by extension a *note method: 184c, is a
     callable.  An instance of a class that implements the *note
     __call__(): 77b. method is also a callable.

callback

     A subroutine function which is passed as an argument to be executed
     at some point in the future.

class

     A template for creating user-defined objects.  Class definitions
     normally contain method definitions which operate on instances of
     the class.

class variable

     A variable defined in a class and intended to be modified only at
     class level (i.e., not in an instance of the class).

closure variable

     A *note free variable: 240c. referenced from a *note nested scope:
     2373. that is defined in an outer scope rather than being resolved
     at runtime from the globals or builtin namespaces.  May be
     explicitly defined with the *note nonlocal: 14af. keyword to allow
     write access, or implicitly defined if the variable is only being
     read.

     For example, in the ‘inner’ function in the following code, both
     ‘x’ and ‘print’ are *note free variables: 240c, but only ‘x’ is a
     'closure variable':

          def outer():
              x = 0
              def inner():
                  nonlocal x
                  x += 1
                  print(x)
              return inner

     Due to the *note codeobject.co_freevars: 232e. attribute (which,
     despite its name, only includes the names of closure variables
     rather than listing all referenced free variables), the more
     general *note free variable: 240c. term is sometimes used even when
     the intended meaning is to refer specifically to closure variables.

complex number

     An extension of the familiar real number system in which all
     numbers are expressed as a sum of a real part and an imaginary
     part.  Imaginary numbers are real multiples of the imaginary unit
     (the square root of ‘-1’), often written ‘i’ in mathematics or ‘j’
     in engineering.  Python has built-in support for complex numbers,
     which are written with this latter notation; the imaginary part is
     written with a ‘j’ suffix, e.g., ‘3+1j’.  To get access to complex
     equivalents of the *note math: 92. module, use *note cmath: 19.
     Use of complex numbers is a fairly advanced mathematical feature.
     If you’re not aware of a need for them, it’s almost certain you can
     safely ignore them.

concurrency

     The ability of a computer program to perform multiple tasks at the
     same time.  Python provides libraries for writing programs that
     make use of different forms of concurrency.  *note asyncio: b. is a
     library for dealing with asynchronous tasks and coroutines.  *note
     threading: f3. provides access to operating system threads and
     *note multiprocessing: 98. to operating system processes.
     Multi-core processors can execute threads and processes on
     different CPU cores at the same time (see *note parallelism:
     5965.).

concurrent modification

     When multiple threads modify shared data at the same time.
     Concurrent modification without proper synchronization can cause
     *note race conditions: 595f, and might also trigger a *note data
     race: 5960, data corruption, or both.

context

     This term has different meanings depending on where and how it is
     used.  Some common meanings:

        * The temporary state or environment established by a *note
          context manager: 1e1. via a *note with: 186. statement.

        * The collection of key­value bindings associated with a
          particular *note contextvars.Context: 177. object and accessed
          via *note ContextVar: 185d. objects.  Also see *note context
          variable: 5967.

        * A *note contextvars.Context: 177. object.  Also see *note
          current context: 194c.

context management protocol

     The *note __enter__(): 7e5. and *note __exit__(): 1508. methods
     called by the *note with: 186. statement.  See PEP 343(12).

context manager

     An object which implements the *note context management protocol:
     194d. and controls the environment seen in a *note with: 186.
     statement.  See PEP 343(13).

context variable

     A variable whose value depends on which context is the *note
     current context: 194c.  Values are accessed via *note
     contextvars.ContextVar: 185d. objects.  Context variables are
     primarily used to isolate state between concurrent asynchronous
     tasks.

contiguous

     A buffer is considered contiguous exactly if it is either
     'C-contiguous' or 'Fortran contiguous'.  Zero-dimensional buffers
     are C and Fortran contiguous.  In one-dimensional arrays, the items
     must be laid out in memory next to each other, in order of
     increasing indexes starting from zero.  In multidimensional
     C-contiguous arrays, the last index varies the fastest when
     visiting items in order of memory address.  However, in Fortran
     contiguous arrays, the first index varies the fastest.

coroutine

     Coroutines are a more generalized form of subroutines.  Subroutines
     are entered at one point and exited at another point.  Coroutines
     can be entered, exited, and resumed at many different points.  They
     can be implemented with the *note async def: 7ee. statement.  See
     also PEP 492(14).

coroutine function

     A function which returns a *note coroutine: 6ba. object.  A
     coroutine function may be defined with the *note async def: 7ee.
     statement, and may contain *note await: 18d, *note async for: ca3,
     and *note async with: 185. keywords.  These were introduced by PEP
     492(15).

CPython

     The canonical implementation of the Python programming language, as
     distributed on python.org(16).  The term «CPython» is used when
     necessary to distinguish this implementation from others such as
     Jython or IronPython.

current context

     The *note context: 194b. (*note contextvars.Context: 177. object)
     that is currently used by *note ContextVar: 185d. objects to access
     (get or set) the values of *note context variables: 5967.  Each
     thread has its own current context.  Frameworks for executing
     asynchronous tasks (see *note asyncio: b.) associate each task with
     a context which becomes the current context whenever the task
     starts or resumes execution.

cyclic isolate

     A subgroup of one or more objects that reference each other in a
     reference cycle, but are not referenced by objects outside the
     group.  The goal of the *note cyclic garbage collector: 17c0. is to
     identify these groups and break the reference cycles so that the
     memory can be reclaimed.

data race

     A situation where multiple threads access the same memory location
     concurrently, at least one of the accesses is a write, and the
     threads do not use any synchronization to control their access.
     Data races lead to *note non-deterministic: 5968. behavior and can
     cause data corruption.  Proper use of *note locks: 5969. and other
     *note synchronization primitives: 596a. prevents data races.  Note
     that data races can only happen in native code, but that *note
     native code: 596b. might be exposed in a Python API. See also *note
     race condition: 595f. and *note thread-safe: 596c.

deadlock

     A situation in which two or more tasks (threads, processes, or
     coroutines) wait indefinitely for each other to release resources
     or complete actions, preventing any from making progress.  For
     example, if thread A holds lock 1 and waits for lock 2, while
     thread B holds lock 2 and waits for lock 1, both threads will wait
     indefinitely.  In Python this often arises from acquiring multiple
     locks in conflicting orders or from circular join/await
     dependencies.  Deadlocks can be avoided by always acquiring
     multiple *note locks: 5969. in a consistent order.  See also *note
     lock: 5969. and *note reentrant: 596e.

decorator

     A function returning another function, usually applied as a
     function transformation using the ‘@wrapper’ syntax.  Common
     examples for decorators are *note classmethod(): 48f. and *note
     staticmethod(): 453.

     The decorator syntax is merely syntactic sugar, the following two
     function definitions are semantically equivalent:

          def f(arg):
              ...
          f = staticmethod(f)

          @staticmethod
          def f(arg):
              ...

     The same concept exists for classes, but is less commonly used
     there.  See the documentation for *note function definitions: 2002.
     and *note class definitions: 14df. for more about decorators.

descriptor

     Any object which defines the methods *note __get__(): 16ef, *note
     __set__(): 239b, or *note __delete__(): 1937.  When a class
     attribute is a descriptor, its special binding behavior is
     triggered upon attribute lookup.  Normally, using 'a.b' to get, set
     or delete an attribute looks up the object named 'b' in the class
     dictionary for 'a', but if 'b' is a descriptor, the respective
     descriptor method gets called.  Understanding descriptors is a key
     to a deep understanding of Python because they are the basis for
     many features including functions, methods, properties, class
     methods, static methods, and reference to super classes.

     For more information about descriptors” methods, see *note
     Implementing Descriptors: e4b. or the *note Descriptor How To
     Guide: 16f4.

dictionary

     An associative array, where arbitrary keys are mapped to values.
     The keys can be any object with *note __hash__(): cf5. and *note
     __eq__(): cf4. methods.  Called a hash in Perl.

dictionary comprehension

     A compact way to process all or part of the elements in an iterable
     and return a dictionary with the results.  ‘results = {n: n ** 2
     for n in range(10)}’ generates a dictionary containing key ‘n’
     mapped to value ‘n ** 2’.  See *note Displays for lists, sets and
     dictionaries: 7ed.

dictionary view

     The objects returned from *note dict.keys(): 9d2, *note
     dict.values(): 9d3, and *note dict.items(): 9d4. are called
     dictionary views.  They provide a dynamic view on the dictionary’s
     entries, which means that when the dictionary changes, the view
     reflects these changes.  To force the dictionary view to become a
     full list use ‘list(dictview)’.  See *note Oggetti vista del
     dizionario: 25f4.

docstring

     A string literal which appears as the first expression in a class,
     function or module.  While ignored when the suite is executed, it
     is recognized by the compiler and put into the *note __doc__: b23.
     attribute of the enclosing class, function or module.  Since it is
     available via introspection, it is the canonical place for
     documentation of the object.

duck-typing

     A programming style which does not look at an object’s type to
     determine if it has the right interface; instead, the method or
     attribute is simply called or used («If it looks like a duck and
     quacks like a duck, it must be a duck.») By emphasizing interfaces
     rather than specific types, well-designed code improves its
     flexibility by allowing polymorphic substitution.  Duck-typing
     avoids tests using *note type(): f46. or *note isinstance(): 2ad.
     (Note, however, that duck-typing can be complemented with *note
     abstract base classes: 13be.)  Instead, it typically employs *note
     hasattr(): 6fa. tests or *note EAFP: 305e. programming.

dunder

     An informal short-hand for «double underscore», used when talking
     about a *note special method: 1c48.  For example, ‘__init__’ is
     often pronounced «dunder init».

EAFP

     Easier to ask for forgiveness than permission.  This common Python
     coding style assumes the existence of valid keys or attributes and
     catches exceptions if the assumption proves false.  This clean and
     fast style is characterized by the presence of many *note try: 8f9.
     and *note except: 1ab. statements.  The technique contrasts with
     the *note LBYL: 5971. style common to many other languages such as
     C.

evaluate function

     A function that can be called to evaluate a lazily evaluated
     attribute of an object, such as the value of type aliases created
     with the *note type: 66d. statement.

expression

     A piece of syntax which can be evaluated to some value.  In other
     words, an expression is an accumulation of expression elements like
     literals, names, attribute access, operators or function calls
     which all return a value.  In contrast to many other languages, not
     all language constructs are expressions.  There are also *note
     statement: 2be2.s which cannot be used as expressions, such as
     *note while: 195b.  Assignments are also statements, not
     expressions.

extension module

     A module written in C or C++, using Python’s C API to interact with
     the core and with user code.

f-string

f-strings

     String literals prefixed with ‘f’ or ‘F’ are commonly called
     «f-strings» which is short for *note formatted string literals:
     19a.  See also PEP 498(17).

file object

     An object exposing a file-oriented API (with methods such as
     ‘read()’ or ‘write()’) to an underlying resource.  Depending on the
     way it was created, a file object can mediate access to a real
     on-disk file or to another type of storage or communication device
     (for example standard input/output, in-memory buffers, sockets,
     pipes, etc.).  File objects are also called 'file-like objects' or
     'streams'.

     There are actually three categories of file objects: raw *note
     binary files: 2058, buffered *note binary files: 2058. and *note
     text files: 2057.  Their interfaces are defined in the *note io:
     83. module.  The canonical way to create a file object is by using
     the *note open(): 316. function.

file-like object

     A synonym for *note file object: 13cb.

filesystem encoding and error handler

     Encoding and error handler used by Python to decode bytes from the
     operating system and encode Unicode to the operating system.

     The filesystem encoding must guarantee to successfully decode all
     bytes below 128.  If the file system encoding fails to provide this
     guarantee, API functions can raise *note UnicodeError: 462.

     The *note sys.getfilesystemencoding(): e55. and *note
     sys.getfilesystemencodeerrors(): ee4. functions can be used to get
     the filesystem encoding and error handler.

     The *note filesystem encoding and error handler: 75e. are
     configured at Python startup by the *note PyConfig_Read(): 994.
     function: see *note filesystem_encoding: 41b. and *note
     filesystem_errors: 41c. members of *note PyConfig: 3f7.

     See also the *note locale encoding: 54b.

finder

     An object that tries to find the *note loader: 1a10. for a module
     that is being imported.

     There are two types of finder: *note meta path finders: 1272. for
     use with *note sys.meta_path: f29, and *note path entry finders:
     1273. for use with *note sys.path_hooks: 1226.

     See *note Finders and loaders: 242a. and *note importlib: 7b. for
     much more detail.

floor division

     Mathematical division that rounds down to nearest integer.  The
     floor division operator is ‘//’.  For example, the expression ‘11
     // 4’ evaluates to ‘2’ in contrast to the ‘2.75’ returned by float
     true division.  Note that ‘(-11) // 4’ is ‘-3’ because that is
     ‘-2.75’ rounded 'downward'.  See PEP 238(18).

free threading

     A threading model where multiple threads can run Python bytecode
     simultaneously within the same interpreter.  This is in contrast to
     the *note global interpreter lock: 474. which allows only one
     thread to execute Python bytecode at a time.  See PEP 703(19).

free variable

     Formally, as defined in the *note language execution model: 2409, a
     free variable is any variable used in a namespace which is not a
     local variable in that namespace.  See *note closure variable:
     187b. for an example.  Pragmatically, due to the name of the *note
     codeobject.co_freevars: 232e. attribute, the term is also sometimes
     used as a synonym for *note closure variable: 187b.

function

     A series of statements which returns some value to a caller.  It
     can also be passed zero or more *note arguments: 67b. which may be
     used in the execution of the body.  See also *note parameter: 2332,
     *note method: 184c, and the *note Function definitions: 2002.
     section.

function annotation

     An *note annotation: 15c. of a function parameter or return value.

     Function annotations are usually used for *note type hints: 23b1.:
     for example, this function is expected to take two *note int: 19b.
     arguments and is also expected to have an *note int: 19b. return
     value:

          def sum_two_numbers(a: int, b: int) -> int:
             return a + b

     Function annotation syntax is explained in section *note Function
     definitions: 2002.

     See *note variable annotation: f53. and PEP 484(20), which describe
     this functionality.  Also see *note Annotations Best Practices:
     9db. for best practices on working with annotations.

__future__

     A *note future statement: 45d, ‘from __future__ import <feature>’,
     directs the compiler to compile the current module using syntax or
     semantics that will become standard in a future release of Python.
     The *note __future__: 0. module documents the possible values of
     'feature'.  By importing this module and evaluating its variables,
     you can see when a new feature was first added to the language and
     when it will (or did) become the default:

          >>> import __future__
          >>> __future__.division
          _Feature((2, 2, 0, 'alpha', 2), (3, 0, 0, 'alpha', 0), 8192)

garbage collection

     The process of freeing memory when it is not used anymore.  Python
     performs garbage collection via reference counting and a cyclic
     garbage collector that is able to detect and break reference
     cycles.  The garbage collector can be controlled using the *note
     gc: 64. module.

generator

     A function which returns a *note generator iterator: ddb.  It looks
     like a normal function except that it contains *note yield: bc4.
     expressions for producing a series of values usable in a for-loop
     or that can be retrieved one at a time with the *note next(): 9da.
     function.

     Usually refers to a generator function, but may refer to a
     'generator iterator' in some contexts.  In cases where the intended
     meaning isn’t clear, using the full terms avoids ambiguity.

generator iterator

     An object created by a *note generator: 1263. function.

     Each *note yield: bc4. temporarily suspends processing, remembering
     the execution state (including local variables and pending
     try-statements).  When the 'generator iterator' resumes, it picks
     up where it left off (in contrast to functions which start fresh on
     every invocation).

generator expression

     An *note expression: 23b5. that returns an *note iterator: 4c9.  It
     looks like a normal expression followed by a ‘for’ clause defining
     a loop variable, range, and an optional ‘if’ clause.  The combined
     expression generates values for an enclosing function:

          >>> sum(i*i for i in range(10))         # sum of squares 0, 1, 4, ... 81
          285

generic function

     A function composed of multiple functions implementing the same
     operation for different types.  Which implementation should be used
     during a call is determined by the dispatch algorithm.

     See also the *note single dispatch: be7. glossary entry, the *note
     functools.singledispatch(): 84c. decorator, and PEP 443(21).

generic type

     A *note type: 1ce6. that can be parameterized; typically a *note
     container class: 23ba. such as *note list: 24d. or *note dict: 183.
     Used for *note type hints: 23b1. and *note annotations: 15c.

     For more details, see *note generic alias types: 8c2, PEP 483(22),
     PEP 484(23), PEP 585(24), and the *note typing: 10a. module.

GIL

     See *note global interpreter lock: 474.

global interpreter lock

     The mechanism used by the *note CPython: 906. interpreter to assure
     that only one thread executes Python *note bytecode: 4ab. at a
     time.  This simplifies the CPython implementation by making the
     object model (including critical built-in types such as *note dict:
     183.) implicitly safe against concurrent access.  Locking the
     entire interpreter makes it easier for the interpreter to be
     multi-threaded, at the expense of much of the parallelism afforded
     by multi-processor machines.

     However, some extension modules, either standard or third-party,
     are designed so as to release the GIL when doing computationally
     intensive tasks such as compression or hashing.  Also, the GIL is
     always released when doing I/O.

     As of Python 3.13, the GIL can be disabled using the *note
     -disable-gil: 49a. build configuration.  After building Python with
     this option, code must be run with *note -X gil=0: 16f. or after
     setting the *note PYTHON_GIL=0: 49b. environment variable.  This
     feature enables improved performance for multi-threaded
     applications and makes it easier to use multi-core CPUs
     efficiently.  For more details, see PEP 703(25).

     In prior versions of Python’s C API, a function might declare that
     it requires the GIL to be held in order to use it.  This refers to
     having an *note attached thread state: 4eba.

global state

     Data that is accessible throughout a program, such as module-level
     variables, class variables, or C static variables in *note
     extension modules: 223a.  In multi-threaded programs, global state
     shared between threads typically requires synchronization to avoid
     *note race conditions: 595f. and *note data races: 5960.

hash-based pyc

     A bytecode cache file that uses the hash rather than the
     last-modified time of the corresponding source file to determine
     its validity.  See *note Cached bytecode invalidation: 803.

hashable

     An object is 'hashable' if it has a hash value which never changes
     during its lifetime (it needs a *note __hash__(): cf5. method), and
     can be compared to other objects (it needs an *note __eq__(): cf4.
     method).  Hashable objects which compare equal must have the same
     hash value.

     Hashability makes an object usable as a dictionary key and a set
     member, because these data structures use the hash value
     internally.

     Most of Python’s immutable built-in objects are hashable; mutable
     containers (such as lists or dictionaries) are not; immutable
     containers (such as tuples and frozensets) are only hashable if
     their elements are hashable.  Objects which are instances of
     user-defined classes are hashable by default.  They all compare
     unequal (except with themselves), and their hash value is derived
     from their *note id(): 162a.

IDLE

     An Integrated Development and Learning Environment for Python.
     *note IDLE — Python editor and shell: 1217. is a basic editor and
     interpreter environment which ships with the standard distribution
     of Python.

immortal

     'Immortal objects' are a CPython implementation detail introduced
     in PEP 683(26).

     If an object is immortal, its *note reference count: 4eb2. is never
     modified, and therefore it is never deallocated while the
     interpreter is running.  For example, *note True: e09. and *note
     None: 886. are immortal in CPython.

     Immortal objects can be identified via *note sys._is_immortal():
     28f, or via *note PyUnstable_IsImmortal(): 3c4. in the C API.

immutable

     An object with a fixed value.  Immutable objects include numbers,
     strings and tuples.  Such an object cannot be altered.  A new
     object has to be created if a different value has to be stored.
     They play an important role in places where a constant hash value
     is needed, for example as a key in a dictionary.  Immutable objects
     are inherently *note thread-safe: 596c. because their state cannot
     be modified after creation, eliminating concerns about improperly
     synchronized *note concurrent modification: 5966.

import path

     A list of locations (or *note path entries: 243b.) that are
     searched by the *note path based finder: 2430. for modules to
     import.  During import, this list of locations usually comes from
     *note sys.path: 3e4, but for subpackages it may also come from the
     parent package’s ‘__path__’ attribute.

importing

     The process by which Python code in one module is made available to
     Python code in another module.

importer

     An object that both finds and loads a module; both a *note finder:
     2351. and *note loader: 1a10. object.

interactive

     Python has an interactive interpreter which means you can enter
     statements and expressions at the interpreter prompt, immediately
     execute them and see their results.  Just launch ‘python’ with no
     arguments (possibly by selecting it from your computer’s main
     menu).  It is a very powerful way to test out new ideas or inspect
     modules and packages (remember ‘help(x)’).  For more on interactive
     mode, see *note Modalità Interattiva: 495.

interpreted

     Python is an interpreted language, as opposed to a compiled one,
     though the distinction can be blurry because of the presence of the
     bytecode compiler.  This means that source files can be run
     directly without explicitly creating an executable which is then
     run.  Interpreted languages typically have a shorter
     development/debug cycle than compiled ones, though their programs
     generally also run more slowly.  See also *note interactive: 1b5.

interpreter shutdown

     When asked to shut down, the Python interpreter enters a special
     phase where it gradually releases all allocated resources, such as
     modules and various critical internal structures.  It also makes
     several calls to the *note garbage collector: 17c0.  This can
     trigger the execution of code in user-defined destructors or
     weakref callbacks.  Code executed during the shutdown phase can
     encounter various exceptions as the resources it relies on may not
     function anymore (common examples are library modules or the
     warnings machinery).

     The main reason for interpreter shutdown is that the ‘__main__’
     module or the script being run has finished executing.

iterable

     An object capable of returning its members one at a time.  Examples
     of iterables include all sequence types (such as *note list: 24d,
     *note str: 169, and *note tuple: 614.) and some non-sequence types
     like *note dict: 183, *note file objects: 13cb, and objects of any
     classes you define with an *note __iter__(): e6b. method or with a
     *note __getitem__(): 588. method that implements *note sequence:
     717. semantics.

     Iterables can be used in a *note for: 34a. loop and in many other
     places where a sequence is needed (*note zip(): 1a0, *note map():
     19f, …).  When an iterable object is passed as an argument to the
     built-in function *note iter(): 9d9, it returns an iterator for the
     object.  This iterator is good for one pass over the set of values.
     When using iterables, it is usually not necessary to call *note
     iter(): 9d9. or deal with iterator objects yourself.  The *note
     for: 34a. statement does that automatically for you, creating a
     temporary unnamed variable to hold the iterator for the duration of
     the loop.  See also *note iterator: 4c9, *note sequence: 717, and
     *note generator: 1263.

iterator

     An object representing a stream of data.  Repeated calls to the
     iterator’s *note __next__(): 14d5. method (or passing it to the
     built-in function *note next(): 9da.) return successive items in
     the stream.  When no more data are available a *note StopIteration:
     df7. exception is raised instead.  At this point, the iterator
     object is exhausted and any further calls to its ‘__next__()’
     method just raise *note StopIteration: df7. again.  Iterators are
     required to have an *note __iter__(): 2097. method that returns the
     iterator object itself so every iterator is also iterable and may
     be used in most places where other iterables are accepted.  One
     notable exception is code which attempts multiple iteration passes.
     A container object (such as a *note list: 24d.) produces a fresh
     new iterator each time you pass it to the *note iter(): 9d9.
     function or use it in a *note for: 34a. loop.  Attempting this with
     an iterator will just return the same exhausted iterator object
     used in the previous iteration pass, making it appear like an empty
     container.

     More information can be found in *note Tipi di Iteratore: 25b3.

     'Dettaglio dell’implementazione di CPython:' CPython does not
     consistently apply the requirement that an iterator define *note
     __iter__(): 2097.  And also please note that *note free-threaded:
     1f4. CPython does not guarantee *note thread-safe: 596c. behavior
     of iterator operations.

key function

     A key function or collation function is a callable that returns a
     value used for sorting or ordering.  For example, *note
     locale.strxfrm(): 17a5. is used to produce a sort key that is aware
     of locale specific sort conventions.

     A number of tools in Python accept key functions to control how
     elements are ordered or grouped.  They include *note min(): 110d,
     *note max(): 110e, *note sorted(): dc9, *note list.sort(): dca,
     *note heapq.merge(): 1007, *note heapq.nsmallest(): 298a, *note
     heapq.nlargest(): 2989, and *note itertools.groupby(): 2b8b.

     There are several ways to create a key function.  For example.  the
     *note str.casefold(): fd8. method can serve as a key function for
     case insensitive sorts.  Alternatively, a key function can be built
     from a *note lambda: 14a5. expression such as ‘lambda r: (r[0],
     r[2])’.  Also, *note operator.attrgetter(): 1035, *note
     operator.itemgetter(): c59, and *note operator.methodcaller():
     1036. are three key function constructors.  See the *note Sorting
     HOW TO: 25bb. for examples of how to create and use key functions.

keyword argument

     See *note argument: 67b.

lambda

     An anonymous inline function consisting of a single *note
     expression: 23b5. which is evaluated when the function is called.
     The syntax to create a lambda function is ‘lambda [parameters]:
     expression’

LBYL

     Look before you leap.  This coding style explicitly tests for
     pre-conditions before making calls or lookups.  This style
     contrasts with the *note EAFP: 305e. approach and is characterized
     by the presence of many *note if: 181. statements.

     In a multi-threaded environment, the LBYL approach can risk
     introducing a *note race condition: 595f. between «the looking» and
     «the leaping».  For example, the code, ‘if key in mapping: return
     mapping[key]’ can fail if another thread removes 'key' from
     'mapping' after the test, but before the lookup.  This issue can be
     solved with *note locks: 5969. or by using the *note EAFP: 305e.
     approach.  See also *note thread-safe: 596c.

lexical analyzer

     Formal name for the 'tokenizer'; see *note token: 2271.

list

     A built-in Python *note sequence: 717.  Despite its name it is more
     akin to an array in other languages than to a linked list since
     access to elements is 'O'(1).

list comprehension

     A compact way to process all or part of the elements in a sequence
     and return a list with the results.  ‘result = ['{:#04x}'.format(x)
     for x in range(256) if x % 2 == 0]’ generates a list of strings
     containing even hex numbers (0x..)  in the range from 0 to 255.
     The *note if: 181. clause is optional.  If omitted, all elements in
     ‘range(256)’ are processed.

lock

     A *note synchronization primitive: 596a. that allows only one
     thread at a time to access a shared resource.  A thread must
     acquire a lock before accessing the protected resource and release
     it afterward.  If a thread attempts to acquire a lock that is
     already held by another thread, it will block until the lock
     becomes available.  Python’s *note threading: f3. module provides
     *note Lock: 19dc. (a basic lock) and *note RLock: 32e. (a *note
     reentrant: 596e. lock).  Locks are used to prevent *note race
     conditions: 595f. and ensure *note thread-safe: 596c. access to
     shared data.  Alternative design patterns to locks exist such as
     queues, producer/consumer patterns, and thread-local state.  See
     also *note deadlock: 596d, and *note reentrant: 596e.

loader

     An object that loads a module.  It must define the ‘exec_module()’
     and ‘create_module()’ methods to implement the *note Loader: 10c9.
     interface.  A loader is typically returned by a *note finder: 2351.
     See also:

        * *note Finders and loaders: 242a.

        * *note importlib.abc.Loader: 10c9.

        * PEP 302(27)

locale encoding

     On Unix, it is the encoding of the LC_CTYPE locale.  It can be set
     with *note locale.setlocale(locale.LC_CTYPE, new_locale): 328.

     On Windows, it is the ANSI code page (ex: ‘"cp1252"’).

     On Android and VxWorks, Python uses ‘"utf-8"’ as the locale
     encoding.

     *note locale.getencoding(): 329. can be used to get the locale
     encoding.

     See also the *note filesystem encoding and error handler: 75e.

magic method

     An informal synonym for *note special method: 1c48.

mapping

     A container object that supports arbitrary key lookups and
     implements the methods specified in the *note
     collections.abc.Mapping: ac9. or *note
     collections.abc.MutableMapping: 12b4. *note abstract base classes:
     a7a.  Examples include *note dict: 183, *note
     collections.defaultdict: 13c4, *note collections.OrderedDict: 7f4.
     and *note collections.Counter: 1299.

meta path finder

     A *note finder: 2351. returned by a search of *note sys.meta_path:
     f29.  Meta path finders are related to, but different from *note
     path entry finders: 1273.

     See *note importlib.abc.MetaPathFinder: a70. for the methods that
     meta path finders implement.

metaclass

     The class of a class.  Class definitions create a class name, a
     class dictionary, and a list of base classes.  The metaclass is
     responsible for taking those three arguments and creating the
     class.  Most object oriented programming languages provide a
     default implementation.  What makes Python special is that it is
     possible to create custom metaclasses.  Most users never need this
     tool, but when the need arises, metaclasses can provide powerful,
     elegant solutions.  They have been used for logging attribute
     access, adding thread-safety, tracking object creation,
     implementing singletons, and many other tasks.

     More information can be found in *note Metaclasses: 23a4.

method

     A function which is defined inside a class body.  If called as an
     attribute of an instance of that class, the method will get the
     instance object as its first *note argument: 67b. (which is usually
     called ‘self’).  See *note function: 2491. and *note nested scope:
     2373.

method resolution order

     Method Resolution Order is the order in which base classes are
     searched for a member during lookup.  See *note The Python 2.3
     Method Resolution Order: 16b1. for details of the algorithm used by
     the Python interpreter since the 2.3 release.

module

     An object that serves as an organizational unit of Python code.
     Modules have a namespace containing arbitrary Python objects.
     Modules are loaded into Python by the process of *note importing:
     2420.

     See also *note package: 233.

module spec

     A namespace containing the import-related information used to load
     a module.  An instance of *note importlib.machinery.ModuleSpec:
     2255.

     See also *note Module specs: 234d.

MRO

     See *note method resolution order: 25bd.

mutable

     An *note object: 5979. with state that is allowed to change during
     the course of the program.  In multi-threaded programs, mutable
     objects that are shared between threads require careful
     synchronization to avoid *note race conditions: 595f.  See also
     *note immutable: 1fc8, *note thread-safe: 596c, and *note
     concurrent modification: 5966.

named tuple

     The term «named tuple» applies to any type or class that inherits
     from tuple and whose indexable elements are also accessible using
     named attributes.  The type or class may have other features as
     well.

     Several built-in types are named tuples, including the values
     returned by *note time.localtime(): 1700. and *note os.stat(): 26d.
     Another example is *note sys.float_info: 1db7.:

          >>> sys.float_info[1]                   # indexed access
          1024
          >>> sys.float_info.max_exp              # named field access
          1024
          >>> isinstance(sys.float_info, tuple)   # kind of tuple
          True

     Some named tuples are built-in types (such as the above examples).
     Alternatively, a named tuple can be created from a regular class
     definition that inherits from *note tuple: 614. and that defines
     named fields.  Such a class can be written by hand, or it can be
     created by inheriting *note typing.NamedTuple: 331, or with the
     factory function *note collections.namedtuple(): 4e1.  The latter
     techniques also add some extra methods that may not be found in
     hand-written or built-in named tuples.

namespace

     The place where a variable is stored.  Namespaces are implemented
     as dictionaries.  There are the local, global and built-in
     namespaces as well as nested namespaces in objects (in methods).
     Namespaces support modularity by preventing naming conflicts.  For
     instance, the functions *note builtins.open: 316. and *note
     os.open(): f94. are distinguished by their namespaces.  Namespaces
     also aid readability and maintainability by making it clear which
     module implements a function.  For instance, writing *note
     random.seed(): 147b. or *note itertools.islice(): d45. makes it
     clear that those functions are implemented by the *note random: bd.
     and *note itertools: 85. modules, respectively.

namespace package

     A *note package: 233. which serves only as a container for
     subpackages.  Namespace packages may have no physical
     representation, and specifically are not like a *note regular
     package: 2424. because they have no ‘__init__.py’ file.

     Namespace packages allow several individually installable packages
     to have a common parent package.  Otherwise, it is recommended to
     use a *note regular package: 2424.

     For more information, see PEP 420(28) and *note Namespace packages:
     2426.

     See also *note module: 19c6.

native code

     Code that is compiled to machine instructions and runs directly on
     the processor, as opposed to code that is interpreted or runs in a
     virtual machine.  In the context of Python, native code typically
     refers to C, C++, Rust or Fortran code in *note extension modules:
     223a. that can be called from Python.  See also *note extension
     module: 223a.

nested scope

     The ability to refer to a variable in an enclosing definition.  For
     instance, a function defined inside another function can refer to
     variables in the outer function.  Note that nested scopes by
     default work only for reference and not for assignment.  Local
     variables both read and write in the innermost scope.  Likewise,
     global variables read and write to the global namespace.  The *note
     nonlocal: 14af. allows writing to outer scopes.

new-style class

     Old name for the flavor of classes now used for all class objects.
     In earlier Python versions, only new-style classes could use
     Python’s newer, versatile features like *note __slots__: 16f2,
     descriptors, properties, *note __getattribute__(): dcd, class
     methods, and static methods.

non-deterministic

     Behavior where the outcome of a program can vary between executions
     with the same inputs.  In multi-threaded programs,
     non-deterministic behavior often results from *note race
     conditions: 595f. where the relative timing or interleaving of
     threads affects the result.  Proper synchronization using *note
     locks: 5969. and other *note synchronization primitives: 596a.
     helps ensure deterministic behavior.

object

     Any data with state (attributes or value) and defined behavior
     (methods).  Also the ultimate base class of any *note new-style
     class: 2cf0.

optimized scope

     A scope where target local variable names are reliably known to the
     compiler when the code is compiled, allowing optimization of read
     and write access to these names.  The local namespaces for
     functions, generators, coroutines, comprehensions, and generator
     expressions are optimized in this fashion.  Note: most interpreter
     optimizations are applied to all scopes, only those relying on a
     known set of local and nonlocal variable names are restricted to
     optimized scopes.

optional module

     An *note extension module: 223a. that is part of the *note standard
     library: 597a, but may be absent in some builds of *note CPython:
     906, usually due to missing third-party libraries or because the
     module is not available for a given platform.

     See *note Requirements for optional modules: 2141. for a list of
     optional modules that require third-party libraries.

package

     A Python *note module: 19c6. which can contain submodules or
     recursively, subpackages.  Technically, a package is a Python
     module with a ‘__path__’ attribute.

     See also *note regular package: 2424. and *note namespace package:
     2b2.

parallelism

     Executing multiple operations at the same time (e.g.  on multiple
     CPU cores).  In Python builds with the *note global interpreter
     lock (GIL): 474, only one thread runs Python bytecode at a time, so
     taking advantage of multiple CPU cores typically involves multiple
     processes (e.g.  *note multiprocessing: 98.) or native extensions
     that release the GIL. In *note free-threaded: 1f4. Python, multiple
     Python threads can run Python code simultaneously on different
     cores.

parameter

     A named entity in a *note function: 2491. (or method) definition
     that specifies an *note argument: 67b. (or in some cases,
     arguments) that the function can accept.  There are five kinds of
     parameter:

        * 'positional-or-keyword': specifies an argument that can be
          passed either *note positionally: 67b. or as a *note keyword
          argument: 67b.  This is the default kind of parameter, for
          example 'foo' and 'bar' in the following:

               def func(foo, bar=None): ...

        * 'positional-only': specifies an argument that can be supplied
          only by position.  Positional-only parameters can be defined
          by including a ‘/’ character in the parameter list of the
          function definition after them, for example 'posonly1' and
          'posonly2' in the following:

               def func(posonly1, posonly2, /, positional_or_keyword): ...

        * 'keyword-only': specifies an argument that can be supplied
          only by keyword.  Keyword-only parameters can be defined by
          including a single var-positional parameter or bare ‘*’ in the
          parameter list of the function definition before them, for
          example 'kw_only1' and 'kw_only2' in the following:

               def func(arg, *, kw_only1, kw_only2): ...

        * 'var-positional': specifies that an arbitrary sequence of
          positional arguments can be provided (in addition to any
          positional arguments already accepted by other parameters).
          Such a parameter can be defined by prepending the parameter
          name with ‘*’, for example 'args' in the following:

               def func(*args, **kwargs): ...

        * 'var-keyword': specifies that arbitrarily many keyword
          arguments can be provided (in addition to any keyword
          arguments already accepted by other parameters).  Such a
          parameter can be defined by prepending the parameter name with
          ‘**’, for example 'kwargs' in the example above.

     Parameters can specify both optional and required arguments, as
     well as default values for some optional arguments.

     See also the *note argument: 67b. glossary entry, the FAQ question
     on *note the difference between arguments and parameters: 5898, the
     *note inspect.Parameter: 4e5. class, the *note Function
     definitions: 2002. section, and PEP 362(29).

path entry

     A single location on the *note import path: 242d. which the *note
     path based finder: 2430. consults to find modules for importing.

path entry finder

     A *note finder: 2351. returned by a callable on *note
     sys.path_hooks: 1226. (i.e.  a *note path entry hook: 243d.) which
     knows how to locate modules given a *note path entry: 243b.

     See *note importlib.abc.PathEntryFinder: a71. for the methods that
     path entry finders implement.

path entry hook

     A callable on the *note sys.path_hooks: 1226. list which returns a
     *note path entry finder: 1273. if it knows how to find modules on a
     specific *note path entry: 243b.

path based finder

     One of the default *note meta path finders: 1272. which searches an
     *note import path: 242d. for modules.

path-like object

     An object representing a file system path.  A path-like object is
     either a *note str: 169. or *note bytes: 192. object representing a
     path, or an object implementing the *note os.PathLike: e4d.
     protocol.  An object that supports the *note os.PathLike: e4d.
     protocol can be converted to a *note str: 169. or *note bytes: 192.
     file system path by calling the *note os.fspath(): e4f. function;
     *note os.fsdecode(): e50. and *note os.fsencode(): e51. can be used
     to guarantee a *note str: 169. or *note bytes: 192. result instead,
     respectively.  Introduced by PEP 519(30).

PEP

     Python Enhancement Proposal.  A PEP is a design document providing
     information to the Python community, or describing a new feature
     for Python or its processes or environment.  PEPs should provide a
     concise technical specification and a rationale for proposed
     features.

     PEPs are intended to be the primary mechanisms for proposing major
     new features, for collecting community input on an issue, and for
     documenting the design decisions that have gone into Python.  The
     PEP author is responsible for building consensus within the
     community and documenting dissenting opinions.

     See PEP 1(31).

portion

     A set of files in a single directory (possibly stored in a zip
     file) that contribute to a namespace package, as defined in PEP
     420(32).

positional argument

     See *note argument: 67b.

provisional API

     A provisional API is one which has been deliberately excluded from
     the standard library’s backwards compatibility guarantees.  While
     major changes to such interfaces are not expected, as long as they
     are marked provisional, backwards incompatible changes (up to and
     including removal of the interface) may occur if deemed necessary
     by core developers.  Such changes will not be made gratuitously –
     they will occur only if serious fundamental flaws are uncovered
     that were missed prior to the inclusion of the API.

     Even for provisional APIs, backwards incompatible changes are seen
     as a «solution of last resort» - every attempt will still be made
     to find a backwards compatible resolution to any identified
     problems.

     This process allows the standard library to continue to evolve over
     time, without locking in problematic design errors for extended
     periods of time.  See PEP 411(33) for more details.

provisional package

     See *note provisional API: 3d1.

Python 3000

     Nickname for the Python 3.x release line (coined long ago when the
     release of version 3 was something in the distant future.)  This is
     also abbreviated «Py3k».

Pythonic

     An idea or piece of code which closely follows the most common
     idioms of the Python language, rather than implementing code using
     concepts common to other languages.  For example, a common idiom in
     Python is to loop over all elements of an iterable using a *note
     for: 34a. statement.  Many other languages don’t have this type of
     construct, so people unfamiliar with Python sometimes use a
     numerical counter instead:

          for i in range(len(food)):
              print(food[i])

     As opposed to the cleaner, Pythonic method:

          for piece in food:
              print(piece)

qualified name

     A dotted name showing the «path» from a module’s global scope to a
     class, function or method defined in that module, as defined in PEP
     3155(34).  For top-level functions and classes, the qualified name
     is the same as the object’s name:

          >>> class C:
          ...     class D:
          ...         def meth(self):
          ...             pass
          ...
          >>> C.__qualname__
          'C'
          >>> C.D.__qualname__
          'C.D'
          >>> C.D.meth.__qualname__
          'C.D.meth'

     When used to refer to modules, the 'fully qualified name' means the
     entire dotted path to the module, including any parent packages,
     e.g.  ‘email.mime.text’:

          >>> import email.mime.text
          >>> email.mime.text.__name__
          'email.mime.text'

race condition

     A condition of a program where the its behavior depends on the
     relative timing or ordering of events, particularly in
     multi-threaded programs.  Race conditions can lead to *note
     non-deterministic: 5968. behavior and bugs that are difficult to
     reproduce.  A *note data race: 5960. is a specific type of race
     condition involving unsynchronized access to shared memory.  The
     *note LBYL: 5971. coding style is particularly susceptible to race
     conditions in multi-threaded code.  Using *note locks: 5969. and
     other *note synchronization primitives: 596a. helps prevent race
     conditions.

reference count

     The number of references to an object.  When the reference count of
     an object drops to zero, it is deallocated.  Some objects are *note
     immortal: 290. and have reference counts that are never modified,
     and therefore the objects are never deallocated.  Reference
     counting is generally not visible to Python code, but it is a key
     element of the *note CPython: 906. implementation.  Programmers can
     call the *note sys.getrefcount(): 2ce. function to return the
     reference count for a particular object.

     In *note CPython: 906, reference counts are not considered to be
     stable or well-defined values; the number of references to an
     object, and how that number is affected by Python code, may be
     different between versions.

regular package

     A traditional *note package: 233, such as a directory containing an
     ‘__init__.py’ file.

     See also *note namespace package: 2b2.

reentrant

     A property of a function or *note lock: 5969. that allows it to be
     called or acquired multiple times by the same thread without
     causing errors or a *note deadlock: 596d.

     For functions, reentrancy means the function can be safely called
     again before a previous invocation has completed, which is
     important when functions may be called recursively or from signal
     handlers.  Thread-unsafe functions may be *note non-deterministic:
     5968. if they’re called reentrantly in a multithreaded program.

     For locks, Python’s *note threading.RLock: 32e. (reentrant lock) is
     reentrant, meaning a thread that already holds the lock can acquire
     it again without blocking.  In contrast, *note threading.Lock:
     19dc. is not reentrant - attempting to acquire it twice from the
     same thread will cause a deadlock.

     See also *note lock: 5969. and *note deadlock: 596d.

REPL

     An acronym for the «read–eval–print loop», another name for the
     *note interactive: 1b5. interpreter shell.

__slots__

     A declaration inside a class that saves memory by pre-declaring
     space for instance attributes and eliminating instance
     dictionaries.  Though popular, the technique is somewhat tricky to
     get right and is best reserved for rare cases where there are large
     numbers of instances in a memory-critical application.

sequence

     An *note iterable: 142f. which supports efficient element access
     using integer indices via the *note __getitem__(): 588. special
     method and defines a *note __len__(): 1777. method that returns the
     length of the sequence.  Some built-in sequence types are *note
     list: 24d, *note str: 169, *note tuple: 614, and *note bytes: 192.
     Note that *note dict: 183. also supports *note __getitem__(): 588.
     and ‘__len__()’, but is considered a mapping rather than a sequence
     because the lookups use arbitrary *note hashable: 825. keys rather
     than integers.

     The *note collections.abc.Sequence: 13cc. abstract base class
     defines a much richer interface that goes beyond just *note
     __getitem__(): 588. and *note __len__(): 1777, adding *note
     count(): 23be, *note index(): 1961, *note __contains__(): 15c1, and
     *note __reversed__(): e88.  Types that implement this expanded
     interface can be registered explicitly using *note register():
     1290.  For more documentation on sequence methods generally, see
     *note Common Sequence Operations: 25e6.

set comprehension

     A compact way to process all or part of the elements in an iterable
     and return a set with the results.  ‘results = {c for c in
     'abracadabra' if c not in 'abc'}’ generates the set of strings
     ‘{'r', 'd'}’.  See *note Displays for lists, sets and dictionaries:
     7ed.

single dispatch

     A form of *note generic function: be6. dispatch where the
     implementation is chosen based on the type of a single argument.

slice

     An object usually containing a portion of a *note sequence: 717.  A
     slice is created using the subscript notation, ‘[]’ with colons
     between numbers when several are given, such as in
     ‘variable_name[1:3:5]’.  The bracket (subscript) notation uses
     *note slice: 695. objects internally.

soft deprecated

     A soft deprecated API should not be used in new code, but it is
     safe for already existing code to use it.  The API remains
     documented and tested, but will not be enhanced further.

     Soft deprecation, unlike normal deprecation, does not plan on
     removing the API and will not emit warnings.

     See PEP 387: Soft Deprecation(35).

special method

     A method that is called implicitly by Python to execute a certain
     operation on a type, such as addition.  Such methods have names
     starting and ending with double underscores.  Special methods are
     documented in *note Special method names: e6a.

standard library

     The collection of *note packages: 233, *note modules: 19c6. and
     *note extension modules: 223a. distributed as a part of the
     official Python interpreter package.  The exact membership of the
     collection may vary based on platform, available system libraries,
     or other criteria.  Documentation can be found at *note The Python
     Standard Library: 149.

     See also *note sys.stdlib_module_names: a44. for a list of all
     possible standard library module names.

statement

     A statement is part of a suite (a «block» of code).  A statement is
     either an *note expression: 23b5. or one of several constructs with
     a keyword, such as *note if: 181, *note while: 195b. or *note for:
     34a.

static type checker

     An external tool that reads Python code and analyzes it, looking
     for issues such as incorrect types.  See also *note type hints:
     23b1. and the *note typing: 10a. module.

stdlib

     An abbreviation of *note standard library: 597a.

strong reference

     In Python’s C API, a strong reference is a reference to an object
     which is owned by the code holding the reference.  The strong
     reference is taken by calling *note Py_INCREF(): 790. when the
     reference is created and released with *note Py_DECREF(): 791. when
     the reference is deleted.

     The *note Py_NewRef(): a9c. function can be used to create a strong
     reference to an object.  Usually, the *note Py_DECREF(): 791.
     function must be called on the strong reference before exiting the
     scope of the strong reference, to avoid leaking one reference.

     See also *note borrowed reference: 3d7.

synchronization primitive

     A basic building block for coordinating (synchronizing) the
     execution of multiple threads to ensure *note thread-safe: 596c.
     access to shared resources.  Python’s *note threading: f3. module
     provides several synchronization primitives including *note Lock:
     19dc, *note RLock: 32e, *note Semaphore: 135e, *note Condition:
     135d, *note Event: 1360, and *note Barrier: 13eb.  Additionally,
     the *note queue: bb. module provides multi-producer, multi-consumer
     queues that are especially useful in multithreaded programs.  These
     primitives help prevent *note race conditions: 595f. and coordinate
     thread execution.  See also *note lock: 5969.

t-string

t-strings

     String literals prefixed with ‘t’ or ‘T’ are commonly called
     «t-strings» which is short for *note template string literals:
     17e2.

text encoding

     A string in Python is a sequence of Unicode code points (in range
     ‘U+0000’–‘U+10FFFF’).  To store or transfer a string, it needs to
     be serialized as a sequence of bytes.

     Serializing a string into a sequence of bytes is known as
     «encoding», and recreating the string from the sequence of bytes is
     known as «decoding».

     There are a variety of different text serialization *note codecs:
     fba, which are collectively referred to as «text encodings».

text file

     A *note file object: 13cb. able to read and write *note str: 169.
     objects.  Often, a text file actually accesses a byte-oriented
     datastream and handles the *note text encoding: 25b7.
     automatically.  Examples of text files are files opened in text
     mode (‘'r'’ or ‘'w'’), *note sys.stdin: 760, *note sys.stdout: ccf,
     and instances of *note io.StringIO: 112b.

     See also *note binary file: 2058. for a file object able to read
     and write *note bytes-like objects: 193.

thread state

     The information used by the *note CPython: 906. runtime to run in
     an OS thread.  For example, this includes the current exception, if
     any, and the state of the bytecode interpreter.

     Each thread state is bound to a single OS thread, but threads may
     have many thread states available.  At most, one of them may be
     *note attached: 4eba. at once.

     An *note attached thread state: 4eba. is required to call most of
     Python’s C API, unless a function explicitly documents otherwise.
     The bytecode interpreter only runs under an attached thread state.

     Each thread state belongs to a single interpreter, but each
     interpreter may have many thread states, including multiple for the
     same OS thread.  Thread states from multiple interpreters may be
     bound to the same thread, but only one can be *note attached: 4eba.
     in that thread at any given moment.

     See *note Thread State and the Global Interpreter Lock: 54f8. for
     more information.

thread-safe

     A module, function, or class that behaves correctly when used by
     multiple threads concurrently.  Thread-safe code uses appropriate
     *note synchronization primitives: 596a. like *note locks: 5969. to
     protect shared mutable state, or is designed to avoid shared
     mutable state entirely.  In the *note free-threaded: 1f4. build,
     built-in types like *note dict: 183, *note list: 24d, and *note
     set: 184. use internal locking to make many operations thread-safe,
     although thread safety is not necessarily guaranteed.  Code that is
     not thread-safe may experience *note race conditions: 595f. and
     *note data races: 5960. when used in multi-threaded programs.

token

     A small unit of source code, generated by the *note lexical
     analyzer: 227e. (also called the 'tokenizer').  Names, numbers,
     strings, operators, newlines and similar are represented by tokens.

     The *note tokenize: 101. module exposes Python’s lexical analyzer.
     The *note token: 100. module contains information on the various
     types of tokens.

triple-quoted string

     A string which is bound by three instances of either a quotation
     mark (») or an apostrophe (“).  While they don’t provide any
     functionality not available with single-quoted strings, they are
     useful for a number of reasons.  They allow you to include
     unescaped single and double quotes within a string and they can
     span multiple lines without the use of the continuation character,
     making them especially useful when writing docstrings.

type

     The type of a Python object determines what kind of object it is;
     every object has a type.  An object’s type is accessible as its
     *note __class__: 16b4. attribute or can be retrieved with
     ‘type(obj)’.

type alias

     A synonym for a type, created by assigning the type to an
     identifier.

     Type aliases are useful for simplifying *note type hints: 23b1.
     For example:

          def remove_gray_shades(
                  colors: list[tuple[int, int, int]]) -> list[tuple[int, int, int]]:
              pass

     could be made more readable like this:

          Color = tuple[int, int, int]

          def remove_gray_shades(colors: list[Color]) -> list[Color]:
              pass

     See *note typing: 10a. and PEP 484(36), which describe this
     functionality.

type hint

     An *note annotation: 15c. that specifies the expected type for a
     variable, a class attribute, or a function parameter or return
     value.

     Type hints are optional and are not enforced by Python but they are
     useful to *note static type checkers: 574.  They can also aid IDEs
     with code completion and refactoring.

     Type hints of global variables, class attributes, and functions,
     but not local variables, can be accessed using *note
     typing.get_type_hints(): 8c1.

     See *note typing: 10a. and PEP 484(37), which describe this
     functionality.

universal newlines

     A manner of interpreting text streams in which all of the following
     are recognized as ending a line: the Unix end-of-line convention
     ‘'\n'’, the Windows convention ‘'\r\n'’, and the old Macintosh
     convention ‘'\r'’.  See PEP 278(38) and PEP 3116(39), as well as
     *note bytes.splitlines(): 2604. for an additional use.

variable annotation

     An *note annotation: 15c. of a variable or a class attribute.

     When annotating a variable or a class attribute, assignment is
     optional:

          class C:
              field: 'annotation'

     Variable annotations are usually used for *note type hints: 23b1.:
     for example this variable is expected to take *note int: 19b.
     values:

          count: int = 0

     Variable annotation syntax is explained in section *note Annotated
     assignment statements: 24e7.

     See *note function annotation: 2003, PEP 484(40) and PEP 526(41),
     which describe this functionality.  Also see *note Annotations Best
     Practices: 9db. for best practices on working with annotations.

virtual environment

     A cooperatively isolated runtime environment that allows Python
     users and applications to install and upgrade Python distribution
     packages without interfering with the behaviour of other Python
     applications running on the same system.

     See also *note venv: 117.

virtual machine

     A computer defined entirely in software.  Python’s virtual machine
     executes the *note bytecode: 4ab. emitted by the bytecode compiler.

walrus operator

     A light-hearted way to refer to the *note assignment expression:
     24b9. operator ‘:=’ because it looks a bit like a walrus if you
     turn your head.

Zen of Python

     Listing of Python design principles and philosophies that are
     helpful in understanding and using the language.  The listing can
     be found by typing «‘import this’» at the interactive prompt.

   ---------- Footnotes ----------

   (1) https://peps.python.org/pep-0484/

   (2) https://peps.python.org/pep-0526/

   (3) https://peps.python.org/pep-0649/

   (4) https://peps.python.org/pep-0362/

   (5) https://peps.python.org/pep-0492/

   (6) https://peps.python.org/pep-0492/

   (7) https://peps.python.org/pep-0525/

   (8) https://peps.python.org/pep-0492/

   (9) https://peps.python.org/pep-0492/

   (10) https://peps.python.org/pep-0492/

   (11) https://gvanrossum.github.io/

   (12) https://peps.python.org/pep-0343/

   (13) https://peps.python.org/pep-0343/

   (14) https://peps.python.org/pep-0492/

   (15) https://peps.python.org/pep-0492/

   (16) https://www.python.org

   (17) https://peps.python.org/pep-0498/

   (18) https://peps.python.org/pep-0238/

   (19) https://peps.python.org/pep-0703/

   (20) https://peps.python.org/pep-0484/

   (21) https://peps.python.org/pep-0443/

   (22) https://peps.python.org/pep-0483/

   (23) https://peps.python.org/pep-0484/

   (24) https://peps.python.org/pep-0585/

   (25) https://peps.python.org/pep-0703/

   (26) https://peps.python.org/pep-0683/

   (27) https://peps.python.org/pep-0302/

   (28) https://peps.python.org/pep-0420/

   (29) https://peps.python.org/pep-0362/

   (30) https://peps.python.org/pep-0519/

   (31) https://peps.python.org/pep-0001/

   (32) https://peps.python.org/pep-0420/

   (33) https://peps.python.org/pep-0411/

   (34) https://peps.python.org/pep-3155/

   (35) https://peps.python.org/pep-0387/#soft-deprecation

   (36) https://peps.python.org/pep-0484/

   (37) https://peps.python.org/pep-0484/

   (38) https://peps.python.org/pep-0278/

   (39) https://peps.python.org/pep-3116/

   (40) https://peps.python.org/pep-0484/

   (41) https://peps.python.org/pep-0526/


File: python.info,  Node: About this documentation,  Next: Come comportarsi con i bug,  Prev: Glossary,  Up: Top

13 About this documentation
***************************

Python’s documentation is generated from reStructuredText(1) sources
using Sphinx(2), a documentation generator originally created for Python
and now maintained as an independent project.

Lo sviluppo della documentazione e della sua toolchain è uno lavoro
svolto esclusivamente da volontari, proprio come lo stesso Python.  Se
si desidera contribuire, si prega di dare un’occhiata alla pagina *note
Come comportarsi con i bug: 4f02. per avere maggiori informazioni su
come farlo.  Nuovi volontari sono sempre i benvenuti!

Molte grazie a:

   * Fred L. Drake, Jr., the creator of the original Python
     documentation toolset and author of much of the content;

   * the Docutils(3) project for creating reStructuredText and the
     Docutils suite;

   * Fredrik Lundh for his Alternative Python Reference project from
     which Sphinx got many good ideas.

* Menu:

* Contributors to the Python documentation::

   ---------- Footnotes ----------

   (1) https://docutils.sourceforge.io/rst.html

   (2) https://www.sphinx-doc.org/

   (3) https://docutils.sourceforge.io/


File: python.info,  Node: Contributors to the Python documentation,  Up: About this documentation

13.1 Contributors to the Python documentation
=============================================

Many people have contributed to the Python language, the Python standard
library, and the Python documentation.  See Misc/ACKS(1) in the Python
source distribution for a partial list of contributors.

È solo con il contributo dei membri della comunità di Python che Python
ha una documentazione così meravigliosa — Grazie!

   ---------- Footnotes ----------

   (1) https://github.com/python/cpython/tree/3.14/Misc/ACKS


File: python.info,  Node: Come comportarsi con i bug,  Next: Copyright,  Prev: About this documentation,  Up: Top

14 Come comportarsi con i 'bug'
*******************************

Python è un linguaggio di programmazione maturo che ha ottenuto una
reputazione di stabilità.  Al fine di mantenere questa reputazione, gli
sviluppatori saranno contenti di ricevere delle segnalazioni nel caso
dovessi trovare eventuali errori in Python.

A volte può essere più veloce correggere da soli i bug e contribuire
mediante patch a Python, in quanto questo snellisce il processo e
coinvolge meno persone.  Impara come fare leggendo: *note contribute:
598b.

* Menu:

* Errori nella Documentazione::
* Utilizzo dell’Issue Tracker di Python::
* Come iniziare a contribuire a Python in autonomia::


File: python.info,  Node: Errori nella Documentazione,  Next: Utilizzo dell’Issue Tracker di Python,  Up: Come comportarsi con i bug

14.1 Errori nella Documentazione
================================

If you find a bug in this documentation or would like to propose an
improvement, please submit a bug report on the *note issue tracker: 557.
If you have a suggestion on how to fix it, include that as well.

If the bug or suggested improvement concerns the translation of this
documentation, submit the report to the translation’s repository(1)
instead.

È possibile anche aprire un argomento di discussione sul nostro forum
Discourse sulla documentazione(2).

If you find a bug in the theme (HTML / CSS / JavaScript) of the
documentation, please submit a bug report on the python-doc-theme issue
tracker(3).

Vedi anche
..........

Documentation bugs(4)

     Un elenco dei bug della documentazione che sono stati inviati al
     sistema di segnalazione dei problemi di Python.

Issue Tracking(5)

     Panoramica del processo coinvolto nella segnalazione di un
     miglioramento sul tracker.

Aiutare con la Documentazione(6)

     Guida completa per le persone interessate a contribuire alla
     documentazione di Python.

Traduzioni della Documentazione(7)

     Un elenco delle pagine GitHub per la traduzione della
     documentazione e i loro contatti principali.

   ---------- Footnotes ----------

   (1) https://github.com/python/python-docs-it

   (2) https://discuss.python.org/c/documentation/26

   (3) https://github.com/python/python-docs-theme

   (4) 
https://github.com/python/cpython/issues?q=is%3Aissue+is%3Aopen+label%3Adocs

   (5) https://devguide.python.org/tracker/

   (6) 
https://devguide.python.org/docquality/#helping-with-documentation

   (7) https://devguide.python.org/documentation/translating/


File: python.info,  Node: Utilizzo dell’Issue Tracker di Python,  Next: Come iniziare a contribuire a Python in autonomia,  Prev: Errori nella Documentazione,  Up: Come comportarsi con i bug

14.2 Utilizzo dell’Issue Tracker di Python
==========================================

I report sui problemi di Python stesso devono essere inviati tramite il
sistema di segnalazione dei problemi su GitHub
(‘https://github.com/python/cpython/issues’).  Il sistema di
segnalazione dei problemi su GitHub offre un modulo web che consente di
inserire e inviare agli sviluppatori le informazioni pertinenti.

Il primo passo per presentare un report è determinare se il problema è
già stato segnalato.  Il vantaggio di farlo, oltre a risparmiare tempo
agli sviluppatori, è scoprire cosa è stato fatto per risolverlo;
potrebbe essere che il problema sia già stato risolto per la prossima
versione, o che siano necessarie ulteriori informazioni (in tal caso sei
invitato a fornirle se puoi!).  Per farlo, cerca nel tracker utilizzando
la casella di ricerca in cima alla pagina.

Se il problema che stai segnalando non è già nell’elenco, accedi a
GitHub.  Se non hai già un account GitHub, crea un nuovo account
utilizzando il link «Sign up».  Non è possibile inviare un report di bug
in modo anonimo.

Essendo ora loggato, puoi inviare un problema.  Clicca sul pulsante «New
issue» nella barra superiore per segnalare un nuovo problema.

Il form di invio ha due campi, «Titolo» e «Commento».

Per il campo «Titolo», inserisci una 'molto' breve descrizione del
problema; meno di dieci parole è considerato buono.

Nel campo «Commento», descrivi in dettaglio il problema, includendo ciò
che ti aspettavi e ciò che è successo.  Assicurati di includere se sono
stati coinvolti moduli di estensione e quale piattaforma hardware e
software stavate utilizzando (incluse le informazioni sulle versioni, se
dovesse essere utile).

Ogni report del problema verrà esaminato da uno sviluppatore che
determinerà cosa deve essere fatto per correggere il problema.
Riceverai un aggiornamento ogni volta che viene intrapresa un’azione sul
problema.

Vedi anche
..........

Come segnalare efficacemente i bug(1)

     Articolo che specifica come creare un’utile segnalazione riguardo
     un 'bug'.  Descrive che tipo di informazione è utile e perché è
     utile.

Linee Guida per la segnalazione dei *Bug*(2)

     Informazioni su come scrivere una buona segnalazione di 'bug'.
     Alcune di queste sono specifiche del progetto Mozilla, ma
     descrivono le buone pratiche generali.

   ---------- Footnotes ----------

   (1) https://www.chiark.greenend.org.uk/~sgtatham/bugs.html

   (2) https://bugzilla.mozilla.org/page.cgi?id=bug-writing.html


File: python.info,  Node: Come iniziare a contribuire a Python in autonomia,  Prev: Utilizzo dell’Issue Tracker di Python,  Up: Come comportarsi con i bug

14.3 Come iniziare a contribuire a Python in autonomia
======================================================

Oltre a segnalare i bug che trovate, saranno apprezzate anche le
eventuali 'patch' per correggerli.  Puoi trovare maggiori informazioni
su come iniziare ad applicare la patch Python nella Python Developer’s
Guide(1).  Se avete domande, la core-mentorship mailing list(2) è un
luogo amichevole per ottenere risposte a tutte le domande relative al
processo di risoluzione dei problemi in Python.

   ---------- Footnotes ----------

   (1) https://devguide.python.org/

   (2) 
https://mail.python.org/mailman3/lists/core-mentorship.python.org/


File: python.info,  Node: Copyright,  Next: Storia e licenza,  Prev: Come comportarsi con i bug,  Up: Top

15 Copyright
************

Python e questa documentazione sono protetti da:

Copyright © 2001 Python Software Foundation.  All rights reserved.

Copyright © 2000 BeOpen.com.  Tutti i diritti riservati.

Copyright © 1995-2000 Corporation for National Research Initiatives.
Tutti i diritti riservati.

Copyright © 1991-1995 Stichting Mathematisch Centrum.  Tutti i diritti
riservati.

__________________________________________________________________

Fare riferimento a *note Storia e licenza: 5992. per informazioni
complete su licenza e permessi.


File: python.info,  Node: Storia e licenza,  Next: Indice del modulo Python,  Prev: Copyright,  Up: Top

16 Storia e licenza
*******************

* Menu:

* Storia del software::
* Termini e condizioni di accesso o di utilizzo di Python::
* Licenze e riconoscimenti per il software incorporato::


File: python.info,  Node: Storia del software,  Next: Termini e condizioni di accesso o di utilizzo di Python,  Up: Storia e licenza

16.1 Storia del software
========================

Python was created in the early 1990s by Guido van Rossum at Stichting
Mathematisch Centrum (CWI, see ‘https://www.cwi.nl’) in the Netherlands
as a successor of a language called ABC. Guido remains Python’s
principal author, although it includes many contributions from others.

In 1995, Guido continued his work on Python at the Corporation for
National Research Initiatives (CNRI, see
‘https://www.cnri.reston.va.us’) in Reston, Virginia where he released
several versions of the software.

In May 2000, Guido and the Python core development team moved to
BeOpen.com to form the BeOpen PythonLabs team.  In October of the same
year, the PythonLabs team moved to Digital Creations, which became Zope
Corporation.  In 2001, the Python Software Foundation (PSF, see
‘https://www.python.org/psf/’) was formed, a non-profit organization
created specifically to own Python-related Intellectual Property.  Zope
Corporation was a sponsoring member of the PSF.

All Python releases are Open Source (see ‘https://opensource.org’ for
the Open Source Definition).  Historically, most, but not all, Python
releases have also been GPL-compatible; the table below summarizes the
various releases.

Rilascio             Derivato da        Anno             Proprietario     GPL-compatible?  (1)
                                                                          
----------------------------------------------------------------------------------------------------
                                                                          
Da 0.9.0 a 1.2       n/d                1991-1995        CWI              sì
                                                                          
                                                                          
Da 1.3 a 1.5.2       1.2                1995-1999        CNRI             sì
                                                                          
                                                                          
1.6                  1.5.2              2000             CNRI             no
                                                                          
                                                                          
2.0                  1.6                2000             BeOpen.com       no
                                                                          
                                                                          
1.6.1                1.6                2001             CNRI             yes (2)
                                                                          
                                                                          
2.1                  2.0+1.6.1          2001             PSF              no
                                                                          
                                                                          
2.0.1                2.0+1.6.1          2001             PSF              sì
                                                                          
                                                                          
2.1.1                2.1+2.0.1          2001             PSF              sì
                                                                          
                                                                          
2.1.2                2.1.1              2002             PSF              sì
                                                                          
                                                                          
2.1.3                2.1.2              2002             PSF              sì
                                                                          
                                                                          
2.2 e superiori      2.1.1              2001-adesso      PSF              sì
                                                                          

     Nota: 
       1. GPL-compatible doesn’t mean that we’re distributing Python
          under the GPL. All Python licenses, unlike the GPL, let you
          distribute a modified version without making your changes open
          source.  The GPL-compatible licenses make it possible to
          combine Python with other software that is released under the
          GPL; the others don’t.

       2. According to Richard Stallman, 1.6.1 is not GPL-compatible,
          because its license has a choice of law clause.  According to
          CNRI, however, Stallman’s lawyer has told CNRI’s lawyer that
          1.6.1 is «not incompatible» with the GPL.

Grazie ai tanti volontari esterni che hanno lavorato sotto la direzione
di Guido per rendere possibili queste 'release'.


File: python.info,  Node: Termini e condizioni di accesso o di utilizzo di Python,  Next: Licenze e riconoscimenti per il software incorporato,  Prev: Storia del software,  Up: Storia e licenza

16.2 Termini e condizioni di accesso o di utilizzo di Python
============================================================

Python software and documentation are licensed under the Python Software
Foundation License Version 2.

Starting with Python 3.8.6, examples, recipes, and other code in the
documentation are dual licensed under the PSF License Version 2 and the
*note Zero-Clause BSD license: 5998.

Some software incorporated into Python is under different licenses.  The
licenses are listed with code falling under that license.  See *note
Licenze e riconoscimenti per il software incorporato: 5999. for an
incomplete list of these licenses.

* Menu:

* PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2::
* CONTRATTO DI LICENZA DI BEOPEN.COM PER PYTHON 2.0: CONTRATTO DI LICENZA DI BEOPEN COM PER PYTHON 2 0.
* CNRI CONTRATTO DI LICENZA PER PYTHON 1.6.1: CNRI CONTRATTO DI LICENZA PER PYTHON 1 6 1.
* CWI CONTRATTO DI LICENZA PER PYTHON DA 0.9.0 A 1.2: CWI CONTRATTO DI LICENZA PER PYTHON DA 0 9 0 A 1 2.
* ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON DOCUMENTATION::


File: python.info,  Node: PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2,  Next: CONTRATTO DI LICENZA DI BEOPEN COM PER PYTHON 2 0,  Up: Termini e condizioni di accesso o di utilizzo di Python

16.2.1 PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
---------------------------------------------------

     1. This LICENSE AGREEMENT is between the Python Software Foundation ("PSF"), and
        the Individual or Organization ("Licensee") accessing and otherwise using this
        software ("Python") in source or binary form and its associated documentation.

     2. Subject to the terms and conditions of this License Agreement, PSF hereby
        grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce,
        analyze, test, perform and/or display publicly, prepare derivative works,
        distribute, and otherwise use Python alone or in any derivative
        version, provided, however, that PSF's License Agreement and PSF's notice of
        copyright, i.e., "Copyright © 2001 Python Software Foundation; All Rights
        Reserved" are retained in Python alone or in any derivative version
        prepared by Licensee.

     3. In the event Licensee prepares a derivative work that is based on or
        incorporates Python or any part thereof, and wants to make the
        derivative work available to others as provided herein, then Licensee hereby
        agrees to include in any such work a brief summary of the changes made to Python.

     4. PSF is making Python available to Licensee on an "AS IS" basis.
        PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.  BY WAY OF
        EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND DISCLAIMS ANY REPRESENTATION OR
        WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT THE
        USE OF PYTHON WILL NOT INFRINGE ANY THIRD PARTY RIGHTS.

     5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON
        FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS A RESULT OF
        MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON, OR ANY DERIVATIVE
        THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.

     6. This License Agreement will automatically terminate upon a material breach of
        its terms and conditions.

     7. Nothing in this License Agreement shall be deemed to create any relationship
        of agency, partnership, or joint venture between PSF and Licensee.  This License
        Agreement does not grant permission to use PSF trademarks or trade name in a
        trademark sense to endorse or promote products or services of Licensee, or any
        third party.

     8. By copying, installing or otherwise using Python, Licensee agrees
        to be bound by the terms and conditions of this License Agreement.


File: python.info,  Node: CONTRATTO DI LICENZA DI BEOPEN COM PER PYTHON 2 0,  Next: CNRI CONTRATTO DI LICENZA PER PYTHON 1 6 1,  Prev: PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2,  Up: Termini e condizioni di accesso o di utilizzo di Python

16.2.2 CONTRATTO DI LICENZA DI BEOPEN.COM PER PYTHON 2.0
--------------------------------------------------------

BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1

     1. This LICENSE AGREEMENT is between BeOpen.com ("BeOpen"), having an office at
        160 Saratoga Avenue, Santa Clara, CA 95051, and the Individual or Organization
        ("Licensee") accessing and otherwise using this software in source or binary
        form and its associated documentation ("the Software").

     2. Subject to the terms and conditions of this BeOpen Python License Agreement,
        BeOpen hereby grants Licensee a non-exclusive, royalty-free, world-wide license
        to reproduce, analyze, test, perform and/or display publicly, prepare derivative
        works, distribute, and otherwise use the Software alone or in any derivative
        version, provided, however, that the BeOpen Python License is retained in the
        Software, alone or in any derivative version prepared by Licensee.

     3. BeOpen is making the Software available to Licensee on an "AS IS" basis.
        BEOPEN MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.  BY WAY OF
        EXAMPLE, BUT NOT LIMITATION, BEOPEN MAKES NO AND DISCLAIMS ANY REPRESENTATION OR
        WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT THE
        USE OF THE SOFTWARE WILL NOT INFRINGE ANY THIRD PARTY RIGHTS.

     4. BEOPEN SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF THE SOFTWARE FOR
        ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS A RESULT OF USING,
        MODIFYING OR DISTRIBUTING THE SOFTWARE, OR ANY DERIVATIVE THEREOF, EVEN IF
        ADVISED OF THE POSSIBILITY THEREOF.

     5. This License Agreement will automatically terminate upon a material breach of
        its terms and conditions.

     6. This License Agreement shall be governed by and interpreted in all respects
        by the law of the State of California, excluding conflict of law provisions.
        Nothing in this License Agreement shall be deemed to create any relationship of
        agency, partnership, or joint venture between BeOpen and Licensee.  This License
        Agreement does not grant permission to use BeOpen trademarks or trade names in a
        trademark sense to endorse or promote products or services of Licensee, or any
        third party.  As an exception, the "BeOpen Python" logos available at
        ‘http://www.pythonlabs.com/logos.html’ may be used according to the permissions
        granted on that web page.

     7. By copying, installing or otherwise using the software, Licensee agrees to be
        bound by the terms and conditions of this License Agreement.


File: python.info,  Node: CNRI CONTRATTO DI LICENZA PER PYTHON 1 6 1,  Next: CWI CONTRATTO DI LICENZA PER PYTHON DA 0 9 0 A 1 2,  Prev: CONTRATTO DI LICENZA DI BEOPEN COM PER PYTHON 2 0,  Up: Termini e condizioni di accesso o di utilizzo di Python

16.2.3 CNRI CONTRATTO DI LICENZA PER PYTHON 1.6.1
-------------------------------------------------

     1. This LICENSE AGREEMENT is between the Corporation for National Research
        Initiatives, having an office at 1895 Preston White Drive, Reston, VA 20191
        ("CNRI"), and the Individual or Organization ("Licensee") accessing and
        otherwise using Python 1.6.1 software in source or binary form and its
        associated documentation.

     2. Subject to the terms and conditions of this License Agreement, CNRI hereby
        grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce,
        analyze, test, perform and/or display publicly, prepare derivative works,
        distribute, and otherwise use Python 1.6.1 alone or in any derivative version,
        provided, however, that CNRI's License Agreement and CNRI's notice of copyright,
        i.e., "Copyright © 1995-2001 Corporation for National Research Initiatives; All
        Rights Reserved" are retained in Python 1.6.1 alone or in any derivative version
        prepared by Licensee.  Alternately, in lieu of CNRI's License Agreement,
        Licensee may substitute the following text (omitting the quotes): "Python 1.6.1
        is made available subject to the terms and conditions in CNRI's License
        Agreement.  This Agreement together with Python 1.6.1 may be located on the
        internet using the following unique, persistent identifier (known as a handle):
        1895.22/1013.  This Agreement may also be obtained from a proxy server on the
        internet using the following URL: ‘http://hdl.handle.net/1895.22/1013’".

     3. In the event Licensee prepares a derivative work that is based on or
        incorporates Python 1.6.1 or any part thereof, and wants to make the derivative
        work available to others as provided herein, then Licensee hereby agrees to
        include in any such work a brief summary of the changes made to Python 1.6.1.

     4. CNRI is making Python 1.6.1 available to Licensee on an "AS IS" basis.  CNRI
        MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.  BY WAY OF EXAMPLE,
        BUT NOT LIMITATION, CNRI MAKES NO AND DISCLAIMS ANY REPRESENTATION OR WARRANTY
        OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF
        PYTHON 1.6.1 WILL NOT INFRINGE ANY THIRD PARTY RIGHTS.

     5. CNRI SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON 1.6.1 FOR
        ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS A RESULT OF
        MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON 1.6.1, OR ANY DERIVATIVE
        THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.

     6. This License Agreement will automatically terminate upon a material breach of
        its terms and conditions.

     7. This License Agreement shall be governed by the federal intellectual property
        law of the United States, including without limitation the federal copyright
        law, and, to the extent such U.S. federal law does not apply, by the law of the
        Commonwealth of Virginia, excluding Virginia's conflict of law provisions.
        Notwithstanding the foregoing, with regard to derivative works based on Python
        1.6.1 that incorporate non-separable material that was previously distributed
        under the GNU General Public License (GPL), the law of the Commonwealth of
        Virginia shall govern this License Agreement only as to issues arising under or
        with respect to Paragraphs 4, 5, and 7 of this License Agreement.  Nothing in
        this License Agreement shall be deemed to create any relationship of agency,
        partnership, or joint venture between CNRI and Licensee.  This License Agreement
        does not grant permission to use CNRI trademarks or trade name in a trademark
        sense to endorse or promote products or services of Licensee, or any third
        party.

     8. By clicking on the "ACCEPT" button where indicated, or by copying, installing
        or otherwise using Python 1.6.1, Licensee agrees to be bound by the terms and
        conditions of this License Agreement.


File: python.info,  Node: CWI CONTRATTO DI LICENZA PER PYTHON DA 0 9 0 A 1 2,  Next: ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON DOCUMENTATION,  Prev: CNRI CONTRATTO DI LICENZA PER PYTHON 1 6 1,  Up: Termini e condizioni di accesso o di utilizzo di Python

16.2.4 CWI CONTRATTO DI LICENZA PER PYTHON DA 0.9.0 A 1.2
---------------------------------------------------------

     Copyright © 1991 - 1995, Stichting Mathematisch Centrum Amsterdam, The
     Netherlands.  All rights reserved.

     Permission to use, copy, modify, and distribute this software and its
     documentation for any purpose and without fee is hereby granted, provided that
     the above copyright notice appear in all copies and that both that copyright
     notice and this permission notice appear in supporting documentation, and that
     the name of Stichting Mathematisch Centrum or CWI not be used in advertising or
     publicity pertaining to distribution of the software without specific, written
     prior permission.

     STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
     SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
     EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE FOR ANY SPECIAL, INDIRECT
     OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
     DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
     ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
     SOFTWARE.


File: python.info,  Node: ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON DOCUMENTATION,  Prev: CWI CONTRATTO DI LICENZA PER PYTHON DA 0 9 0 A 1 2,  Up: Termini e condizioni di accesso o di utilizzo di Python

16.2.5 ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON DOCUMENTATION
-------------------------------------------------------------------

     Permission to use, copy, modify, and/or distribute this software for any
     purpose with or without fee is hereby granted.

     THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
     REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
     AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
     INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
     LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
     OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
     PERFORMANCE OF THIS SOFTWARE.


File: python.info,  Node: Licenze e riconoscimenti per il software incorporato,  Prev: Termini e condizioni di accesso o di utilizzo di Python,  Up: Storia e licenza

16.3 Licenze e riconoscimenti per il software incorporato
=========================================================

Questa sezione è una lista incompleta, ma in crescita, di licenze e
riconoscimenti per software di terze parti incorporate nella
distribuzione Python.

* Menu:

* Mersenne Twister::
* Socket::
* Servizi di socket asincrone::
* Gestione dei cookie::
* Tracciabilità dell’esecuzione::
* Funzioni UUencode e UUdecode::
* Chiamate di procedura remota XML::
* test_epoll::
* Select kqueue::
* SipHash24::
* strtod e dtoa::
* 7.4 OpenSSL: 7 4 OpenSSL.
* expat::
* libffi::
* zlib: zlib<4>.
* cfuhash::
* libmpdec::
* W3C C14N test suite::
* mimalloc::
* asyncio: asyncio<15>.
* Global Unbounded Sequences (GUS): Global Unbounded Sequences GUS.
* Zstandard bindings::


File: python.info,  Node: Mersenne Twister,  Next: Socket,  Up: Licenze e riconoscimenti per il software incorporato

16.3.1 Mersenne Twister
-----------------------

The ‘_random’ C extension underlying the *note random: bd. module
includes code based on a download from
‘http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/MT2002/emt19937ar.html’.
The following are the verbatim comments from the original code:

     A C-program for MT19937, with initialization improved 2002/1/26.
     Coded by Takuji Nishimura and Makoto Matsumoto.

     Before using, initialize the state by using init_genrand(seed)
     or init_by_array(init_key, key_length).

     Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
     All rights reserved.

     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
     are met:

      1. Redistributions of source code must retain the above copyright
         notice, this list of conditions and the following disclaimer.

      2. Redistributions in binary form must reproduce the above copyright
         notice, this list of conditions and the following disclaimer in the
         documentation and/or other materials provided with the distribution.

      3. The names of its contributors may not be used to endorse or promote
         products derived from this software without specific prior written
         permission.

     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


     Any feedback is very welcome.
     http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
     email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)


File: python.info,  Node: Socket,  Next: Servizi di socket asincrone,  Prev: Mersenne Twister,  Up: Licenze e riconoscimenti per il software incorporato

16.3.2 Socket
-------------

The *note socket: d1. module uses the functions, ‘getaddrinfo()’, and
‘getnameinfo()’, which are coded in separate source files from the WIDE
Project, ‘https://www.wide.ad.jp/’.

     Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
     All rights reserved.

     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
     are met:
     1. Redistributions of source code must retain the above copyright
        notice, this list of conditions and the following disclaimer.
     2. Redistributions in binary form must reproduce the above copyright
        notice, this list of conditions and the following disclaimer in the
        documentation and/or other materials provided with the distribution.
     3. Neither the name of the project nor the names of its contributors
        may be used to endorse or promote products derived from this software
        without specific prior written permission.

     THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS "AS IS" AND
     ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
     FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.


File: python.info,  Node: Servizi di socket asincrone,  Next: Gestione dei cookie,  Prev: Socket,  Up: Licenze e riconoscimenti per il software incorporato

16.3.3 Servizi di socket asincrone
----------------------------------

The ‘test.support.asynchat’ and ‘test.support.asyncore’ modules contain
the following notice:

     Copyright 1996 by Sam Rushing

                             All Rights Reserved

     Permission to use, copy, modify, and distribute this software and
     its documentation for any purpose and without fee is hereby
     granted, provided that the above copyright notice appear in all
     copies and that both that copyright notice and this permission
     notice appear in supporting documentation, and that the name of Sam
     Rushing not be used in advertising or publicity pertaining to
     distribution of the software without specific, written prior
     permission.

     SAM RUSHING DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
     INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
     NO EVENT SHALL SAM RUSHING BE LIABLE FOR ANY SPECIAL, INDIRECT OR
     CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
     OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
     NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
     CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.


File: python.info,  Node: Gestione dei cookie,  Next: Tracciabilità dell’esecuzione,  Prev: Servizi di socket asincrone,  Up: Licenze e riconoscimenti per il software incorporato

16.3.4 Gestione dei cookie
--------------------------

Il modulo *note http.cookies: 75. contiene il seguente avviso:

     Copyright 2000 by Timothy O'Malley <timo@alum.mit.edu>

                    All Rights Reserved

     Permission to use, copy, modify, and distribute this software
     and its documentation for any purpose and without fee is hereby
     granted, provided that the above copyright notice appear in all
     copies and that both that copyright notice and this permission
     notice appear in supporting documentation, and that the name of
     Timothy O'Malley  not be used in advertising or publicity
     pertaining to distribution of the software without specific, written
     prior permission.

     Timothy O'Malley DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
     SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
     AND FITNESS, IN NO EVENT SHALL Timothy O'Malley BE LIABLE FOR
     ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
     WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
     ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
     PERFORMANCE OF THIS SOFTWARE.


File: python.info,  Node: Tracciabilità dell’esecuzione,  Next: Funzioni UUencode e UUdecode,  Prev: Gestione dei cookie,  Up: Licenze e riconoscimenti per il software incorporato

16.3.5 Tracciabilità dell’esecuzione
------------------------------------

Il modulo *note trace: 103. contiene il seguente avviso:

     portions copyright 2001, Autonomous Zones Industries, Inc., all rights...
     err...  reserved and offered to the public under the terms of the
     Python 2.2 license.
     Author: Zooko O'Whielacronx
     http://zooko.com/
     mailto:zooko@zooko.com

     Copyright 2000, Mojam Media, Inc., all rights reserved.
     Author: Skip Montanaro

     Copyright 1999, Bioreason, Inc., all rights reserved.
     Author: Andrew Dalke

     Copyright 1995-1997, Automatrix, Inc., all rights reserved.
     Author: Skip Montanaro

     Copyright 1991-1995, Stichting Mathematisch Centrum, all rights reserved.


     Permission to use, copy, modify, and distribute this Python software and
     its associated documentation for any purpose without fee is hereby
     granted, provided that the above copyright notice appears in all copies,
     and that both that copyright notice and this permission notice appear in
     supporting documentation, and that the name of neither Automatrix,
     Bioreason or Mojam Media be used in advertising or publicity pertaining to
     distribution of the software without specific, written prior permission.


File: python.info,  Node: Funzioni UUencode e UUdecode,  Next: Chiamate di procedura remota XML,  Prev: Tracciabilità dell’esecuzione,  Up: Licenze e riconoscimenti per il software incorporato

16.3.6 Funzioni UUencode e UUdecode
-----------------------------------

The ‘uu’ codec contains the following notice:

     Copyright 1994 by Lance Ellinghouse
     Cathedral City, California Republic, United States of America.
                            All Rights Reserved
     Permission to use, copy, modify, and distribute this software and its
     documentation for any purpose and without fee is hereby granted,
     provided that the above copyright notice appear in all copies and that
     both that copyright notice and this permission notice appear in
     supporting documentation, and that the name of Lance Ellinghouse
     not be used in advertising or publicity pertaining to distribution
     of the software without specific, written prior permission.
     LANCE ELLINGHOUSE DISCLAIMS ALL WARRANTIES WITH REGARD TO
     THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
     FITNESS, IN NO EVENT SHALL LANCE ELLINGHOUSE CENTRUM BE LIABLE
     FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
     OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

     Modified by Jack Jansen, CWI, July 1995:
     - Use binascii module to do the actual line-by-line conversion
       between ascii and binary. This results in a 1000-fold speedup. The C
       version is still 5 times faster, though.
     - Arguments more compliant with Python standard


File: python.info,  Node: Chiamate di procedura remota XML,  Next: test_epoll,  Prev: Funzioni UUencode e UUdecode,  Up: Licenze e riconoscimenti per il software incorporato

16.3.7 Chiamate di procedura remota XML
---------------------------------------

Il modulo *note xmlrpc.client: 134. contiene il seguente avviso:

         The XML-RPC client interface is

     Copyright (c) 1999-2002 by Secret Labs AB
     Copyright (c) 1999-2002 by Fredrik Lundh

     By obtaining, using, and/or copying this software and/or its
     associated documentation, you agree that you have read, understood,
     and will comply with the following terms and conditions:

     Permission to use, copy, modify, and distribute this software and
     its associated documentation for any purpose and without fee is
     hereby granted, provided that the above copyright notice appears in
     all copies, and that both that copyright notice and this permission
     notice appear in supporting documentation, and that the name of
     Secret Labs AB or the author not be used in advertising or publicity
     pertaining to distribution of the software without specific, written
     prior permission.

     SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
     TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
     ABILITY AND FITNESS.  IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
     BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
     DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
     WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
     ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
     OF THIS SOFTWARE.


File: python.info,  Node: test_epoll,  Next: Select kqueue,  Prev: Chiamate di procedura remota XML,  Up: Licenze e riconoscimenti per il software incorporato

16.3.8 test_epoll
-----------------

The ‘test.test_epoll’ module contains the following notice:

     Copyright (c) 2001-2006 Twisted Matrix Laboratories.

     Permission is hereby granted, free of charge, to any person obtaining
     a copy of this software and associated documentation files (the
     "Software"), to deal in the Software without restriction, including
     without limitation the rights to use, copy, modify, merge, publish,
     distribute, sublicense, and/or sell copies of the Software, and to
     permit persons to whom the Software is furnished to do so, subject to
     the following conditions:

     The above copyright notice and this permission notice shall be
     included in all copies or substantial portions of the Software.

     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


File: python.info,  Node: Select kqueue,  Next: SipHash24,  Prev: test_epoll,  Up: Licenze e riconoscimenti per il software incorporato

16.3.9 Select kqueue
--------------------

Il modulo *note select: c6. contiene il seguente avviso per
l’interfaccia kqueue:

     Copyright (c) 2000 Doug White, 2006 James Knight, 2007 Christian Heimes
     All rights reserved.

     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
     are met:
     1. Redistributions of source code must retain the above copyright
        notice, this list of conditions and the following disclaimer.
     2. Redistributions in binary form must reproduce the above copyright
        notice, this list of conditions and the following disclaimer in the
        documentation and/or other materials provided with the distribution.

     THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
     ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.


File: python.info,  Node: SipHash24,  Next: strtod e dtoa,  Prev: Select kqueue,  Up: Licenze e riconoscimenti per il software incorporato

16.3.10 SipHash24
-----------------

The file ‘Python/pyhash.c’ contains Marek Majkowski” implementation of
Dan Bernstein’s SipHash24 algorithm.  It contains the following note:

     <MIT License>
     Copyright (c) 2013  Marek Majkowski <marek@popcount.org>

     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
     in the Software without restriction, including without limitation the rights
     to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     copies of the Software, and to permit persons to whom the Software is
     furnished to do so, subject to the following conditions:

     The above copyright notice and this permission notice shall be included in
     all copies or substantial portions of the Software.
     </MIT License>

     Original location:
        https://github.com/majek/csiphash/

     Solution inspired by code from:
        Samuel Neves (supercop/crypto_auth/siphash24/little)
        djb (supercop/crypto_auth/siphash24/little2)
        Jean-Philippe Aumasson (https://131002.net/siphash/siphash24.c)


File: python.info,  Node: strtod e dtoa,  Next: 7 4 OpenSSL,  Prev: SipHash24,  Up: Licenze e riconoscimenti per il software incorporato

16.3.11 strtod e dtoa
---------------------

The file ‘Python/dtoa.c’, which supplies C functions dtoa and strtod for
conversion of C doubles to and from strings, is derived from the file of
the same name by David M. Gay, currently available from
‘https://web.archive.org/web/20220517033456/http://www.netlib.org/fp/dtoa.c’.
The original file, as retrieved on March 16, 2009, contains the
following copyright and licensing notice:

     /****************************************************************
      *
      * The author of this software is David M. Gay.
      *
      * Copyright (c) 1991, 2000, 2001 by Lucent Technologies.
      *
      * Permission to use, copy, modify, and distribute this software for any
      * purpose without fee is hereby granted, provided that this entire notice
      * is included in all copies of any software which is or includes a copy
      * or modification of this software and in all copies of the supporting
      * documentation for such software.
      *
      * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
      * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHOR NOR LUCENT MAKES ANY
      * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
      * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
      *
      ***************************************************************/


File: python.info,  Node: 7 4 OpenSSL,  Next: expat,  Prev: strtod e dtoa,  Up: Licenze e riconoscimenti per il software incorporato

16.3.12 7.4 OpenSSL
-------------------

The modules *note hashlib: 6c, *note posix: b2. and *note ssl: d5. use
the OpenSSL library for added performance if made available by the
operating system.  Additionally, the Windows and macOS installers for
Python may include a copy of the OpenSSL libraries, so we include a copy
of the OpenSSL license here.  For the OpenSSL 3.0 release, and later
releases derived from that, the Apache License v2 applies:

                                   Apache License
                             Version 2.0, January 2004
                          https://www.apache.org/licenses/

     TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

     1. Definitions.

        "License" shall mean the terms and conditions for use, reproduction,
        and distribution as defined by Sections 1 through 9 of this document.

        "Licensor" shall mean the copyright owner or entity authorized by
        the copyright owner that is granting the License.

        "Legal Entity" shall mean the union of the acting entity and all
        other entities that control, are controlled by, or are under common
        control with that entity. For the purposes of this definition,
        "control" means (i) the power, direct or indirect, to cause the
        direction or management of such entity, whether by contract or
        otherwise, or (ii) ownership of fifty percent (50%) or more of the
        outstanding shares, or (iii) beneficial ownership of such entity.

        "You" (or "Your") shall mean an individual or Legal Entity
        exercising permissions granted by this License.

        "Source" form shall mean the preferred form for making modifications,
        including but not limited to software source code, documentation
        source, and configuration files.

        "Object" form shall mean any form resulting from mechanical
        transformation or translation of a Source form, including but
        not limited to compiled object code, generated documentation,
        and conversions to other media types.

        "Work" shall mean the work of authorship, whether in Source or
        Object form, made available under the License, as indicated by a
        copyright notice that is included in or attached to the work
        (an example is provided in the Appendix below).

        "Derivative Works" shall mean any work, whether in Source or Object
        form, that is based on (or derived from) the Work and for which the
        editorial revisions, annotations, elaborations, or other modifications
        represent, as a whole, an original work of authorship. For the purposes
        of this License, Derivative Works shall not include works that remain
        separable from, or merely link (or bind by name) to the interfaces of,
        the Work and Derivative Works thereof.

        "Contribution" shall mean any work of authorship, including
        the original version of the Work and any modifications or additions
        to that Work or Derivative Works thereof, that is intentionally
        submitted to Licensor for inclusion in the Work by the copyright owner
        or by an individual or Legal Entity authorized to submit on behalf of
        the copyright owner. For the purposes of this definition, "submitted"
        means any form of electronic, verbal, or written communication sent
        to the Licensor or its representatives, including but not limited to
        communication on electronic mailing lists, source code control systems,
        and issue tracking systems that are managed by, or on behalf of, the
        Licensor for the purpose of discussing and improving the Work, but
        excluding communication that is conspicuously marked or otherwise
        designated in writing by the copyright owner as "Not a Contribution."

        "Contributor" shall mean Licensor and any individual or Legal Entity
        on behalf of whom a Contribution has been received by Licensor and
        subsequently incorporated within the Work.

     2. Grant of Copyright License. Subject to the terms and conditions of
        this License, each Contributor hereby grants to You a perpetual,
        worldwide, non-exclusive, no-charge, royalty-free, irrevocable
        copyright license to reproduce, prepare Derivative Works of,
        publicly display, publicly perform, sublicense, and distribute the
        Work and such Derivative Works in Source or Object form.

     3. Grant of Patent License. Subject to the terms and conditions of
        this License, each Contributor hereby grants to You a perpetual,
        worldwide, non-exclusive, no-charge, royalty-free, irrevocable
        (except as stated in this section) patent license to make, have made,
        use, offer to sell, sell, import, and otherwise transfer the Work,
        where such license applies only to those patent claims licensable
        by such Contributor that are necessarily infringed by their
        Contribution(s) alone or by combination of their Contribution(s)
        with the Work to which such Contribution(s) was submitted. If You
        institute patent litigation against any entity (including a
        cross-claim or counterclaim in a lawsuit) alleging that the Work
        or a Contribution incorporated within the Work constitutes direct
        or contributory patent infringement, then any patent licenses
        granted to You under this License for that Work shall terminate
        as of the date such litigation is filed.

     4. Redistribution. You may reproduce and distribute copies of the
        Work or Derivative Works thereof in any medium, with or without
        modifications, and in Source or Object form, provided that You
        meet the following conditions:

        (a) You must give any other recipients of the Work or
            Derivative Works a copy of this License; and

        (b) You must cause any modified files to carry prominent notices
            stating that You changed the files; and

        (c) You must retain, in the Source form of any Derivative Works
            that You distribute, all copyright, patent, trademark, and
            attribution notices from the Source form of the Work,
            excluding those notices that do not pertain to any part of
            the Derivative Works; and

        (d) If the Work includes a "NOTICE" text file as part of its
            distribution, then any Derivative Works that You distribute must
            include a readable copy of the attribution notices contained
            within such NOTICE file, excluding those notices that do not
            pertain to any part of the Derivative Works, in at least one
            of the following places: within a NOTICE text file distributed
            as part of the Derivative Works; within the Source form or
            documentation, if provided along with the Derivative Works; or,
            within a display generated by the Derivative Works, if and
            wherever such third-party notices normally appear. The contents
            of the NOTICE file are for informational purposes only and
            do not modify the License. You may add Your own attribution
            notices within Derivative Works that You distribute, alongside
            or as an addendum to the NOTICE text from the Work, provided
            that such additional attribution notices cannot be construed
            as modifying the License.

        You may add Your own copyright statement to Your modifications and
        may provide additional or different license terms and conditions
        for use, reproduction, or distribution of Your modifications, or
        for any such Derivative Works as a whole, provided Your use,
        reproduction, and distribution of the Work otherwise complies with
        the conditions stated in this License.

     5. Submission of Contributions. Unless You explicitly state otherwise,
        any Contribution intentionally submitted for inclusion in the Work
        by You to the Licensor shall be under the terms and conditions of
        this License, without any additional terms or conditions.
        Notwithstanding the above, nothing herein shall supersede or modify
        the terms of any separate license agreement you may have executed
        with Licensor regarding such Contributions.

     6. Trademarks. This License does not grant permission to use the trade
        names, trademarks, service marks, or product names of the Licensor,
        except as required for reasonable and customary use in describing the
        origin of the Work and reproducing the content of the NOTICE file.

     7. Disclaimer of Warranty. Unless required by applicable law or
        agreed to in writing, Licensor provides the Work (and each
        Contributor provides its Contributions) on an "AS IS" BASIS,
        WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
        implied, including, without limitation, any warranties or conditions
        of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
        PARTICULAR PURPOSE. You are solely responsible for determining the
        appropriateness of using or redistributing the Work and assume any
        risks associated with Your exercise of permissions under this License.

     8. Limitation of Liability. In no event and under no legal theory,
        whether in tort (including negligence), contract, or otherwise,
        unless required by applicable law (such as deliberate and grossly
        negligent acts) or agreed to in writing, shall any Contributor be
        liable to You for damages, including any direct, indirect, special,
        incidental, or consequential damages of any character arising as a
        result of this License or out of the use or inability to use the
        Work (including but not limited to damages for loss of goodwill,
        work stoppage, computer failure or malfunction, or any and all
        other commercial damages or losses), even if such Contributor
        has been advised of the possibility of such damages.

     9. Accepting Warranty or Additional Liability. While redistributing
        the Work or Derivative Works thereof, You may choose to offer,
        and charge a fee for, acceptance of support, warranty, indemnity,
        or other liability obligations and/or rights consistent with this
        License. However, in accepting such obligations, You may act only
        on Your own behalf and on Your sole responsibility, not on behalf
        of any other Contributor, and only if You agree to indemnify,
        defend, and hold each Contributor harmless for any liability
        incurred by, or claims asserted against, such Contributor by reason
        of your accepting any such warranty or additional liability.

     END OF TERMS AND CONDITIONS


File: python.info,  Node: expat,  Next: libffi,  Prev: 7 4 OpenSSL,  Up: Licenze e riconoscimenti per il software incorporato

16.3.13 expat
-------------

The *note pyexpat: 12c. extension is built using an included copy of the
expat sources unless the build is configured ‘--with-system-expat’:

     Copyright (c) 1998, 1999, 2000 Thai Open Source Software Center Ltd
                                    and Clark Cooper

     Permission is hereby granted, free of charge, to any person obtaining
     a copy of this software and associated documentation files (the
     "Software"), to deal in the Software without restriction, including
     without limitation the rights to use, copy, modify, merge, publish,
     distribute, sublicense, and/or sell copies of the Software, and to
     permit persons to whom the Software is furnished to do so, subject to
     the following conditions:

     The above copyright notice and this permission notice shall be included
     in all copies or substantial portions of the Software.

     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
     IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
     CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
     TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
     SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


File: python.info,  Node: libffi,  Next: zlib<4>,  Prev: expat,  Up: Licenze e riconoscimenti per il software incorporato

16.3.14 libffi
--------------

The ‘_ctypes’ C extension underlying the *note ctypes: 2e. module is
built using an included copy of the libffi sources unless the build is
configured ‘--with-system-libffi’:

     Copyright (c) 1996-2008  Red Hat, Inc and others.

     Permission is hereby granted, free of charge, to any person obtaining
     a copy of this software and associated documentation files (the
     "Software"), to deal in the Software without restriction, including
     without limitation the rights to use, copy, modify, merge, publish,
     distribute, sublicense, and/or sell copies of the Software, and to
     permit persons to whom the Software is furnished to do so, subject to
     the following conditions:

     The above copyright notice and this permission notice shall be included
     in all copies or substantial portions of the Software.

     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
     HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
     WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     DEALINGS IN THE SOFTWARE.


File: python.info,  Node: zlib<4>,  Next: cfuhash,  Prev: libffi,  Up: Licenze e riconoscimenti per il software incorporato

16.3.15 zlib
------------

L’estensione *note zlib: 139. è costruita usando una copia dei sorgenti
zlib se la versione zlib trovata sul sistema è troppo vecchia per essere
usata per la build:

     Copyright (C) 1995-2011 Jean-loup Gailly and Mark Adler

     This software is provided 'as-is', without any express or implied
     warranty.  In no event will the authors be held liable for any damages
     arising from the use of this software.

     Permission is granted to anyone to use this software for any purpose,
     including commercial applications, and to alter it and redistribute it
     freely, subject to the following restrictions:

     1. The origin of this software must not be misrepresented; you must not
        claim that you wrote the original software. If you use this software
        in a product, an acknowledgment in the product documentation would be
        appreciated but is not required.

     2. Altered source versions must be plainly marked as such, and must not be
        misrepresented as being the original software.

     3. This notice may not be removed or altered from any source distribution.

     Jean-loup Gailly        Mark Adler
     jloup@gzip.org          madler@alumni.caltech.edu


File: python.info,  Node: cfuhash,  Next: libmpdec,  Prev: zlib<4>,  Up: Licenze e riconoscimenti per il software incorporato

16.3.16 cfuhash
---------------

L’implementazione della tabella hash utilizzata da *note tracemalloc:
105. si basa sul progetto cfuhash:

     Copyright (c) 2005 Don Owens
     All rights reserved.

     This code is released under the BSD license:

     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
     are met:

       * Redistributions of source code must retain the above copyright
         notice, this list of conditions and the following disclaimer.

       * Redistributions in binary form must reproduce the above
         copyright notice, this list of conditions and the following
         disclaimer in the documentation and/or other materials provided
         with the distribution.

       * Neither the name of the author nor the names of its
         contributors may be used to endorse or promote products derived
         from this software without specific prior written permission.

     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
     COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     OF THE POSSIBILITY OF SUCH DAMAGE.


File: python.info,  Node: libmpdec,  Next: W3C C14N test suite,  Prev: cfuhash,  Up: Licenze e riconoscimenti per il software incorporato

16.3.17 libmpdec
----------------

The ‘_decimal’ C extension underlying the *note decimal: 3a. module is
built using an included copy of the libmpdec library unless the build is
configured ‘--with-system-libmpdec’:

     Copyright (c) 2008-2020 Stefan Krah. All rights reserved.

     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
     are met:

     1. Redistributions of source code must retain the above copyright
        notice, this list of conditions and the following disclaimer.

     2. Redistributions in binary form must reproduce the above copyright
        notice, this list of conditions and the following disclaimer in the
        documentation and/or other materials provided with the distribution.

     THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
     ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.


File: python.info,  Node: W3C C14N test suite,  Next: mimalloc,  Prev: libmpdec,  Up: Licenze e riconoscimenti per il software incorporato

16.3.18 W3C C14N test suite
---------------------------

The C14N 2.0 test suite in the *note test: e8. package
(‘Lib/test/xmltestdata/c14n-20/’) was retrieved from the W3C website at
‘https://www.w3.org/TR/xml-c14n2-testcases/’ and is distributed under
the 3-clause BSD license:

     Copyright (c) 2013 W3C(R) (MIT, ERCIM, Keio, Beihang),
     All Rights Reserved.

     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
     are met:

     * Redistributions of works must retain the original copyright notice,
       this list of conditions and the following disclaimer.
     * Redistributions in binary form must reproduce the original copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.
     * Neither the name of the W3C nor the names of its contributors may be
       used to endorse or promote products derived from this work without
       specific prior written permission.

     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


File: python.info,  Node: mimalloc,  Next: asyncio<15>,  Prev: W3C C14N test suite,  Up: Licenze e riconoscimenti per il software incorporato

16.3.19 mimalloc
----------------

MIT License:

     Copyright (c) 2018-2021 Microsoft Corporation, Daan Leijen

     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
     in the Software without restriction, including without limitation the rights
     to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     copies of the Software, and to permit persons to whom the Software is
     furnished to do so, subject to the following conditions:

     The above copyright notice and this permission notice shall be included in all
     copies or substantial portions of the Software.

     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
     AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     SOFTWARE.


File: python.info,  Node: asyncio<15>,  Next: Global Unbounded Sequences GUS,  Prev: mimalloc,  Up: Licenze e riconoscimenti per il software incorporato

16.3.20 asyncio
---------------

Parts of the *note asyncio: b. module are incorporated from uvloop
0.16(1), which is distributed under the MIT license:

     Copyright (c) 2015-2021 MagicStack Inc.  http://magic.io

     Permission is hereby granted, free of charge, to any person obtaining
     a copy of this software and associated documentation files (the
     "Software"), to deal in the Software without restriction, including
     without limitation the rights to use, copy, modify, merge, publish,
     distribute, sublicense, and/or sell copies of the Software, and to
     permit persons to whom the Software is furnished to do so, subject to
     the following conditions:

     The above copyright notice and this permission notice shall be
     included in all copies or substantial portions of the Software.

     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

   ---------- Footnotes ----------

   (1) https://github.com/MagicStack/uvloop/tree/v0.16.0


File: python.info,  Node: Global Unbounded Sequences GUS,  Next: Zstandard bindings,  Prev: asyncio<15>,  Up: Licenze e riconoscimenti per il software incorporato

16.3.21 Global Unbounded Sequences (GUS)
----------------------------------------

The file ‘Python/qsbr.c’ is adapted from FreeBSD’s «Global Unbounded
Sequences» safe memory reclamation scheme in subr_smr.c(1).  The file is
distributed under the 2-Clause BSD License:

     Copyright (c) 2019,2020 Jeffrey Roberson <jeff@FreeBSD.org>

     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
     are met:
     1. Redistributions of source code must retain the above copyright
        notice unmodified, this list of conditions, and the following
        disclaimer.
     2. Redistributions in binary form must reproduce the above copyright
        notice, this list of conditions and the following disclaimer in the
        documentation and/or other materials provided with the distribution.

     THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
     IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

   ---------- Footnotes ----------

   (1) 
https://github.com/freebsd/freebsd-src/blob/main/sys/kern/subr_smr.c


File: python.info,  Node: Zstandard bindings,  Prev: Global Unbounded Sequences GUS,  Up: Licenze e riconoscimenti per il software incorporato

16.3.22 Zstandard bindings
--------------------------

Zstandard bindings in ‘Modules/_zstd’ and ‘Lib/compression/zstd’ are
based on code from the pyzstd library(1), copyright Ma Lin and
contributors.  The pyzstd code is distributed under the 3-Clause BSD
License:

     Copyright (c) 2020-present, Ma Lin and contributors.
     All rights reserved.

     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions are met:

     1. Redistributions of source code must retain the above copyright notice, this
        list of conditions and the following disclaimer.

     2. Redistributions in binary form must reproduce the above copyright notice,
        this list of conditions and the following disclaimer in the documentation
        and/or other materials provided with the distribution.

     3. Neither the name of the copyright holder nor the names of its
        contributors may be used to endorse or promote products derived from
        this software without specific prior written permission.

     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
     AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
     FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
     CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

   ---------- Footnotes ----------

   (1) https://github.com/Rogdham/pyzstd/


File: python.info,  Node: Indice del modulo Python,  Next: Indice,  Prev: Storia e licenza,  Up: Top

Indice del modulo Python
************************

* Menu:

* __future__: 0. Future statement definitions
* __main__: 1. The environment where top-level code is run. Covers
                        command-line interfaces, import-time
                        behavior, and ''__name__ ==
                        '__main__'''.
* _thread: 2. Low-level threading API.
* _tkinter: 3. A binary module that contains the low-level interface
                        to Tcl/Tk.
* abc: 4. Abstract base classes according to :pep:'3119'.
* aifc: 5. Removed in 3.13.
* annotationlib: 6. Functionality for introspecting annotations
* argparse: 7. Command-line option and argument parsing library.
* array: 8. Space efficient arrays of uniformly typed numeric
                        values.
* ast: 9. Abstract Syntax Tree classes and manipulation.
* asynchat: a. Removed in 3.12.
* asyncio: b. Asynchronous I/O.
* asyncore: c. Removed in 3.12.
* atexit: d. Register and execute cleanup functions.
* audioop: e. Removed in 3.13.
* base64: f. RFC 4648: Base16, Base32, Base64 Data
                        Encodings; Base85 and Ascii85
* bdb: 10. Debugger framework.
* binascii: 11. Tools for converting between binary and various ASCII-
                        encoded binary representations.
* bisect: 12. Array bisection algorithms for binary searching.
* builtins: 13. The module that provides the built-in namespace.
* bz2: 14. Interfaces for bzip2 compression and decompression.
* calendar: 15. Functions for working with calendars, including
                        some emulation of the Unix cal program.
* cgi: 16. Removed in 3.13.
* cgitb: 17. Removed in 3.13.
* chunk: 18. Removed in 3.13.
* cmath: 19. Mathematical functions for complex numbers.
* cmd: 1a. Build line-oriented command interpreters.
* code: 1b. Facilities to implement read-eval-print loops.
* codecs: 1c. Encode and decode data and streams.
* codeop: 1d. Compile (possibly incomplete) Python code.
* collections: 1e. Container datatypes
* collections.abc: 1f. Abstract base classes for containers
* colorsys: 20. Conversion functions between RGB and other color
                        systems.
* compileall: 21. Tools for byte-compiling all Python source files in a
                        directory tree.
* compression: 22.
* compression.zstd: 23. Low-level interface to compression and decompression
                        routines in the zstd library.
* concurrent.futures: 24. Execute computations concurrently using threads or
                        processes.
* concurrent.interpreters: 25. Multiple interpreters in the same process
* configparser: 26. Configuration file parser.
* contextlib: 27. Utilities for with-statement contexts.
* contextvars: 28. Context Variables
* copy: 29. Shallow and deep copy operations.
* copyreg: 2a. Register pickle support functions.
* cProfile: 2b.
* crypt: 2c. Removed in 3.13.
* csv: 2d. Write and read tabular data to and from delimited
                        files.
* ctypes: 2e. A foreign function library for Python.
* curses: 2f. An interface to the curses library, providing
                        portable terminal handling.
* curses.ascii: 30. Constants and set-membership functions for ASCII
                        characters.
* curses.panel: 31. A panel stack extension that adds depth to curses
                        windows.
* curses.textpad: 32. Emacs-like input editing in a curses window.
* dataclasses: 33. Generate special methods on user-defined classes.
* datetime: 34. Basic date and time types.
* dbm: 35. Interfaces to various Unix "database" formats.
* dbm.dumb: 36. Portable implementation of the simple DBM interface.
* dbm.gnu: 37. GNU database manager
* dbm.ndbm: 38. The New Database Manager
* dbm.sqlite3: 39. SQLite backend for dbm
* decimal: 3a. Implementation of the General Decimal Arithmetic
                        Specification.
* difflib: 3b. Helpers for computing differences between objects.
* dis: 3c. Disassembler for Python bytecode.
* distutils: 3d. Removed in 3.12.
* doctest: 3e. Test pieces of code within docstrings.
* email: 3f. Package supporting the parsing,
                        manipulating, and generating email messages.
* email.charset: 40. Character Sets
* email.contentmanager: 41. Storing and Retrieving Content from MIME Parts
* email.encoders: 42. Encoders for email message payloads.
* email.errors: 43. The exception classes used by the email package.
* email.generator: 44. Generate flat text email messages from a message
                        structure.
* email.header: 45. Representing non-ASCII headers
* email.headerregistry: 46. Automatic Parsing of headers based on the field name
* email.iterators: 47. Iterate over a message object tree.
* email.message: 48. The base class representing email messages.
* email.mime: 49. Build MIME messages.
* email.mime.application: 4a.
* email.mime.audio: 4b.
* email.mime.base: 4c.
* email.mime.image: 4d.
* email.mime.message: 4e.
* email.mime.multipart: 4f.
* email.mime.nonmultipart: 50.
* email.mime.text: 51.
* email.parser: 52. Parse flat text email messages to produce a message
                        object structure.
* email.policy: 53. Controlling the parsing and generating of messages
* email.utils: 54. Miscellaneous email package utilities.
* encodings: 55. Encodings package
* encodings.idna: 56. Internationalized Domain Names implementation
* encodings.mbcs: 57. Windows ANSI codepage
* encodings.utf_8_sig: 58. UTF-8 codec with BOM signature
* ensurepip: 59. Bootstrapping the "pip" installer into an existing
                        Python installation or virtual environment.
* enum: 5a. Implementation of an enumeration class.
* errno: 5b. Standard errno system symbols.
* faulthandler: 5c. Dump the Python traceback.
* fcntl: 5d. The fcntl() and ioctl() system calls.
* filecmp: 5e. Compare files efficiently.
* fileinput: 5f. Loop over standard input or a list of files.
* fnmatch: 60. Unix shell style filename pattern matching.
* fractions: 61. Rational numbers.
* ftplib: 62. FTP protocol client (requires sockets).
* functools: 63. Higher-order functions and operations on callable
                        objects.
* gc: 64. Interface to the cycle-detecting garbage collector.
* getopt: 65. Portable parser for command line options; support both
                        short and long option names.
* getpass: 66. Portable reading of passwords and retrieval of the
                        userid.
* gettext: 67. Multilingual internationalization services.
* glob: 68. Unix shell style pathname pattern expansion.
* graphlib: 69. Functionality to operate with graph-like structures
* grp: 6a. The group database (getgrnam() and friends).
* gzip: 6b. Interfaces for gzip compression and decompression
                        using file objects.
* hashlib: 6c. Secure hash and message digest algorithms.
* heapq: 6d. Heap queue algorithm (a.k.a. priority queue).
* hmac: 6e. Keyed-Hashing for Message Authentication (HMAC)
                        implementation
* html: 6f. Helpers for manipulating HTML.
* html.entities: 70. Definitions of HTML general entities.
* html.parser: 71. A simple parser that can handle HTML and XHTML.
* http: 72. HTTP status codes and messages
* http.client: 73. HTTP and HTTPS protocol client (requires sockets).
* http.cookiejar: 74. Classes for automatic handling of HTTP cookies.
* http.cookies: 75. Support for HTTP state management (cookies).
* http.server: 76. HTTP server and request handlers.
* idlelib: 77. Implementation package for the IDLE shell/editor.
* imaplib: 78. IMAP4 protocol client (requires sockets).
* imghdr: 79. Removed in 3.13.
* imp: 7a. Removed in 3.12.
* importlib: 7b. The implementation of the import machinery.
* importlib.abc: 7c. Abstract base classes related to import
* importlib.machinery: 7d. Importers and path hooks
* importlib.metadata: 7e. Accessing package metadata
* importlib.resources: 7f. Package resource reading, opening, and
                        access
* importlib.resources.abc: 80. Abstract base classes for resources
* importlib.util: 81. Utility code for importers
* inspect: 82. Extract information and source code from live objects.
* io: 83. Core tools for working with streams.
* ipaddress: 84. IPv4/IPv6 manipulation library.
* itertools: 85. Functions creating iterators for efficient looping.
* json: 86. Encode and decode the JSON format.
* json.tool: 87. A command-line interface to validate and pretty-print
                        JSON.
* keyword: 88. Test whether a string is a keyword in Python.
* linecache: 89. Provides random access to individual lines from text
                        files.
* locale: 8a. Internationalization services.
* logging: 8b. Flexible event logging system for applications.
* logging.config: 8c. Configuration of the logging module.
* logging.handlers: 8d. Handlers for the logging module.
* lzma: 8e. A Python wrapper for the liblzma compression library.
* mailbox: 8f. Manipulate mailboxes in various formats
* mailcap: 90. Removed in 3.13.
* marshal: 91. Convert Python objects to streams of bytes and back
                        (with different constraints).
* math: 92. Mathematical functions (sin() etc.).
* mimetypes: 93. Mapping of filename extensions to MIME types.
* mmap: 94. Interface to memory-mapped files for Unix and Windows.
* modulefinder: 95. Find modules used by a script.
* msilib: 96. Removed in 3.13.
* msvcrt: 97. Miscellaneous useful routines from the MS VC++
                        runtime.
* multiprocessing: 98. Process-based parallelism.
* multiprocessing.connection: 99. API for dealing with sockets.
* multiprocessing.dummy: 9a. Dumb wrapper around threading.
* multiprocessing.managers: 9b. Share data between process with shared objects.
* multiprocessing.pool: 9c. Create pools of processes.
* multiprocessing.shared_memory: 9d. Provides shared memory for direct access
                                 across processes.
* multiprocessing.sharedctypes: 9e. Allocate ctypes objects from shared memory.
* netrc: 9f. Loading of .netrc files.
* nis: a0. Removed in 3.13.
* nntplib: a1. Removed in 3.13.
* numbers: a2. Numeric abstract base classes (Complex,
                        Real, Integral, etc.).
* operator: a3. Functions corresponding to the standard operators.
* optparse: a4. Command-line option parsing library.
* os: a5. Miscellaneous operating system interfaces.
* os.path: a6. Operations on pathnames.
* ossaudiodev: a7. Removed in 3.13.
* pathlib: a8. Object-oriented filesystem paths
* pathlib.types: a9. pathlib types for static type checking
* pdb: aa. The Python debugger for interactive interpreters.
* pickle: ab. Convert Python objects to streams of bytes and back.
* pickletools: ac. Contains extensive comments about the pickle protocols
                        and pickle-machine opcodes, as well as some
                        useful functions.
* pipes: ad. Removed in 3.13.
* pkgutil: ae. Utilities for the import system.
* platform: af. Retrieves as much platform identifying data as
                        possible.
* plistlib: b0. Generate and parse Apple plist files.
* poplib: b1. POP3 protocol client (requires sockets).
* posix: b2. The most common POSIX system calls (normally used via
                        module os).
* pprint: b3. Data pretty printer.
* profile: b4. Python source profiler.
* pstats: b5. Statistics object for use with the profiler.
* pty: b6. Pseudo-Terminal Handling for Unix.
* pwd: b7. The password database (getpwnam() and friends).
* py_compile: b8. Generate byte-code files from Python source files.
* pyclbr: b9. Supports information extraction for a Python module
                        browser.
* pydoc: ba. Documentation generator and online help system.
* queue: bb. A synchronized queue class.
* quopri: bc. Encode and decode files using the MIME quoted-
                        printable encoding.
* random: bd. Generate pseudo-random numbers with various common
                        distributions.
* re: be. Regular expression operations.
* readline: bf. GNU readline support for Python.
* reprlib: c0. Alternate repr() implementation with size limits.
* resource: c1. An interface to provide resource usage information on
                        the current process.
* rlcompleter: c2. Python identifier completion, suitable for the
                        GNU readline library.
* runpy: c3. Locate and run Python modules without importing them
                        first.
* sched: c4. General purpose event scheduler.
* secrets: c5. Generate secure random numbers for managing secrets.
* select: c6. Wait for I/O completion on multiple streams.
* selectors: c7. High-level I/O multiplexing.
* shelve: c8. Python object persistence.
* shlex: c9. Simple lexical analysis for Unix shell-like languages.
* shutil: ca. High-level file operations, including copying.
* signal: cb. Set handlers for asynchronous events.
* site: cc. Module responsible for site-specific configuration.
* sitecustomize: cd.
* smtpd: ce. Removed in 3.12.
* smtplib: cf. SMTP protocol client (requires sockets).
* sndhdr: d0. Removed in 3.13.
* socket: d1. Low-level networking interface.
* socketserver: d2. A framework for network servers.
* spwd: d3. Removed in 3.13.
* sqlite3: d4. A DB-API 2.0 implementation using SQLite 3.x.
* ssl: d5. TLS/SSL wrapper for socket objects
* stat: d6. Utilities for interpreting the results of
                        os.stat(), os.lstat() and os.fstat().
* statistics: d7. Mathematical statistics functions
* string: d8. Common string operations.
* string.templatelib: d9. Support for template string literals.
* stringprep: da. String preparation, as per RFC 3453
* struct: db. Interpret bytes as packed binary data.
* subprocess: dc. Subprocess management.
* sunau: dd. Removed in 3.13.
* symtable: de. Interface to the compiler's internal symbol tables.
* sys: df. Access system-specific parameters and functions.
* sys.monitoring: e0. Access and control event monitoring
* sysconfig: e1. Python's configuration information
* syslog: e2. An interface to the Unix syslog library routines.
* tabnanny: e3. Tool for detecting white space related problems in
                        Python source files in a directory tree.
* tarfile: e4. Read and write tar-format archive files.
* telnetlib: e5. Removed in 3.13.
* tempfile: e6. Generate temporary files and directories.
* termios: e7. POSIX style tty control.
* test: e8. Regression tests package containing the testing suite
                        for Python.
* test.regrtest: e9. Drives the regression test suite.
* test.support: ea. Support for Python's regression test suite.
* test.support.bytecode_helper: eb. Support tools for testing correct bytecode
                                generation.
* test.support.import_helper: ec. Support for import tests.
* test.support.os_helper: ed. Support for os tests.
* test.support.script_helper: ee. Support for Python's script execution tests.
* test.support.socket_helper: ef. Support for socket tests.
* test.support.threading_helper: f0. Support for threading tests.
* test.support.warnings_helper: f1. Support for warnings tests.
* textwrap: f2. Text wrapping and filling
* threading: f3. Thread-based parallelism.
* time: f4. Time access and conversions.
* timeit: f5. Measure the execution time of small code snippets.
* tkinter: f6. Interface to Tcl/Tk for graphical user interfaces
* tkinter.colorchooser: f7. Color choosing dialog
* tkinter.commondialog: f8. Tkinter base class for dialogs
* tkinter.dnd: f9. Tkinter drag-and-drop interface
* tkinter.filedialog: fa. Dialog classes for file selection
* tkinter.font: fb. Tkinter font-wrapping class
* tkinter.messagebox: fc. Various types of alert dialogs
* tkinter.scrolledtext: fd. Text widget with a vertical scroll bar.
* tkinter.simpledialog: fe. Simple dialog windows
* tkinter.ttk: ff. Tk themed widget set
* token: 100. Constants representing terminal nodes of the parse
                        tree.
* tokenize: 101. Lexical scanner for Python source code.
* tomllib: 102. Parse TOML files.
* trace: 103. Trace or track Python statement execution.
* traceback: 104. Print or retrieve a stack traceback.
* tracemalloc: 105. Trace memory allocations.
* tty: 106. Utility functions that perform common terminal control
                        operations.
* turtle: 107. An educational framework for simple graphics
                        applications
* turtledemo: 108. A viewer for example turtle scripts
* types: 109. Names for built-in types.
* typing: 10a. Support for type hints (see :pep:'484').
* unicodedata: 10b. Access the Unicode Database.
* unittest: 10c. Unit testing framework for Python.
* unittest.mock: 10d. Mock object library.
* urllib: 10e.
* urllib.error: 10f. Exception classes raised by urllib.request.
* urllib.parse: 110. Parse URLs into or assemble them from components.
* urllib.request: 111. Extensible library for opening URLs.
* urllib.response: 112. Response classes used by urllib.
* urllib.robotparser: 113. Load a robots.txt file and answer questions about
                        fetchability of other URLs.
* usercustomize: 114.
* uu: 115. Removed in 3.13.
* uuid: 116. UUID objects (universally unique identifiers)
                        according to RFC 9562
* venv: 117. Creation of virtual environments.
* warnings: 118. Issue warning messages and control their disposition.
* wave: 119. Provide an interface to the WAV sound format.
* weakref: 11a. Support for weak references and weak dictionaries.
* webbrowser: 11b. Easy-to-use controller for web browsers.
* winreg: 11c. Routines and objects for manipulating the Windows
                        registry.
* winsound: 11d. Access to the sound-playing machinery for Windows.
* wsgiref: 11e. WSGI Utilities and Reference Implementation.
* wsgiref.handlers: 11f. WSGI server/gateway base classes.
* wsgiref.headers: 120. WSGI response header tools.
* wsgiref.simple_server: 121. A simple WSGI HTTP server.
* wsgiref.types: 122. WSGI types for static type checking
* wsgiref.util: 123. WSGI environment utilities.
* wsgiref.validate: 124. WSGI conformance checker.
* xdrlib: 125. Removed in 3.13.
* xml: 126. Package containing XML processing modules
* xml.dom: 127. Document Object Model API for Python.
* xml.dom.minidom: 128. Minimal Document Object Model (DOM) implementation.
* xml.dom.pulldom: 129. Support for building partial DOM trees from SAX
                        events.
* xml.etree.ElementInclude: 12a.
* xml.etree.ElementTree: 12b. Implementation of the ElementTree API.
* xml.parsers.expat: 12c. An interface to the Expat non-validating XML parser.
* xml.parsers.expat.errors: 12d.
* xml.parsers.expat.model: 12e.
* xml.sax: 12f. Package containing SAX2 base classes and convenience
                        functions.
* xml.sax.handler: 130. Base classes for SAX event handlers.
* xml.sax.saxutils: 131. Convenience functions and classes for use with SAX.
* xml.sax.xmlreader: 132. Interface which SAX-compliant XML parsers must
                        implement.
* xmlrpc: 133. Server and client modules implementing XML-RPC.
* xmlrpc.client: 134. XML-RPC client access.
* xmlrpc.server: 135. Basic XML-RPC server implementations.
* zipapp: 136. Manage executable Python zip archives
* zipfile: 137. Read and write ZIP-format archive files.
* zipimport: 138. Support for importing Python modules from ZIP
                        archives.
* zlib: 139. Low-level interface to compression and decompression
                        routines compatible with gzip.
* zoneinfo: 13a. IANA time zone support


File: python.info,  Node: Indice,  Prev: Indice del modulo Python,  Up: Top

Indice
******

[index]
* Menu:

* _ (underscore);gettext:                GNU gettext API.    (line   32)
* _ (underscore);in numeric literal:     Numeric literals.   (line   20)
* _ (underscore);in numeric literal <1>: Integer literals.   (line   64)
* _ (underscore);in string formatting:   Format Specification Mini-Language.
                                                             (line  136)
* __, identifiers:                       Soft Keywords.      (line   24)
* __abs__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line   85)
* __abs__() (object metodo):             Emulating numeric types.
                                                             (line  116)
* __add__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line   90)
* __add__() (object metodo):             Emulating numeric types.
                                                             (line   11)
* __aenter__() (object metodo):          Asynchronous Context Managers.
                                                             (line   14)
* __aexit__() (object metodo):           Asynchronous Context Managers.
                                                             (line   19)
* __aiter__() (object metodo):           Asynchronous Iterators.
                                                             (line   14)
* __all__:                               Importare * Da un Pacchetto.
                                                             (line    6)
* __all__ (module attributo):            The import statement.
                                                             (line   84)
* __all__ (optional module attribute):   The import statement.
                                                             (line   84)
* __all__ (package variable):            Importing Modules<2>.
                                                             (line    9)
* __and__() (enum.Flag metodo):          Data Types<2>.      (line  504)
* __and__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line   95)
* __and__() (object metodo):             Emulating numeric types.
                                                             (line   11)
* __anext__() (agen metodo):             Asynchronous generator-iterator methods.
                                                             (line   10)
* __anext__() (object metodo):           Asynchronous Iterators.
                                                             (line   18)
* __annotate__ (class attribute):        Special attributes. (line    6)
* __annotate__ (function attribute):     Special writable attributes.
                                                             (line    6)
* __annotate__ (function attributo):     Special writable attributes.
                                                             (line   55)
* __annotate__ (module attribute):       Modules<2>.         (line   21)
* __annotate__ (module attributo):       Other writable attributes on module objects.
                                                             (line   23)
* __annotate__() (object metodo):        Annotations.        (line   20)
* __annotate__() (type metodo):          Special attributes. (line   72)
* __annotations__ (class attribute):     Special attributes. (line    6)
* __annotations__ (function attribute):  Special writable attributes.
                                                             (line    6)
* __annotations__ (function attributo):  Special writable attributes.
                                                             (line   45)
* __annotations__ (module attribute):    Modules<2>.         (line   21)
* __annotations__ (module attributo):    Other writable attributes on module objects.
                                                             (line   14)
* __annotations__ (object attributo):    Annotations.        (line   10)
* __annotations__ (type attributo):      Special attributes. (line   44)
* __args__ (genericalias attributo):     Attributi Speciali per oggetti GenericAlias.
                                                             (line   16)
* __await__() (object metodo):           Awaitable Objects.  (line   14)
* __base__ (class attribute):            Special attributes. (line    6)
* __base__ (type attributo):             Special attributes. (line   33)
* __bases__ (class attribute):           Special attributes. (line    6)
* __bases__ (type attributo):            Special attributes. (line   27)
* __bool__() (object method):            Emulating container types.
                                                             (line   46)
* __bool__() (object metodo):            Basic customization.
                                                             (line  322)
* __bound__ (typing.TypeVar attributo):  Building generic types and type aliases.
                                                             (line  175)
* __breakpointhook__ (nel modulo sys):   sys — System-specific parameters and functions.
                                                             (line  420)
* __buffer__() (object metodo):          Emulating buffer types.
                                                             (line   15)
* __builtins__ (function attribute):     Special read-only attributes.
                                                             (line    6)
* __builtins__ (function attributo):     Special read-only attributes.
                                                             (line   10)
* __bytes__() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  129)
* __bytes__() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  139)
* __bytes__() (object metodo):           Basic customization.
                                                             (line  146)
* __cached__ (module attribute):         Modules<2>.         (line   21)
* __cached__ (module attributo):         Import-related attributes on module objects.
                                                             (line  138)
* __call__() (argparse.Action metodo):   Action classes.     (line   28)
* __call__() (email.headerregistry.HeaderRegistry metodo): email headerregistry Custom Header Objects.
                                                             (line  390)
* __call__() (enum.EnumType metodo):     Data Types<2>.      (line   20)
* __call__() (nel modulo operator):      operator — Standard operators as functions.
                                                             (line  233)
* __call__() (object method):            Calls.              (line  159)
* __call__() (object metodo):            Emulating callable objects.
                                                             (line    6)
* __call__() (weakref.finalize metodo):  weakref — Weak references.
                                                             (line  295)
* __callback__ (weakref.ref attributo):  weakref — Weak references.
                                                             (line  126)
* __cause__ (BaseException attributo):   Exception context.  (line    9)
* __cause__ (exception attribute):       The raise statement.
                                                             (line   30)
* __cause__ (exception attribute) <1>:   Exception context.  (line    6)
* __cause__ (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line   44)
* __ceil__() (fractions.Fraction metodo): fractions — Rational numbers.
                                                             (line  201)
* __ceil__() (object metodo):            Emulating numeric types.
                                                             (line  146)
* __class__ (instance attribute):        Special attributes<2>.
                                                             (line    6)
* __class__ (method cell):               Creating the class object.
                                                             (line    6)
* __class__ (module attribute):          Customizing module attribute access.
                                                             (line    6)
* __class__ (module attributo):          Customizing module attribute access.
                                                             (line   24)
* __class__ (object attributo):          Special attributes<2>.
                                                             (line    6)
* __class__ (unittest.mock.Mock attributo): The Mock Class.  (line  561)
* __class_getitem__() (object metodo della classe): Emulating generic types.
                                                             (line   32)
* __classcell__ (class namespace entry): Creating the class object.
                                                             (line    6)
* __closure__ (function attribute):      Special read-only attributes.
                                                             (line    6)
* __closure__ (function attributo):      Special read-only attributes.
                                                             (line   22)
* __code__ (attributo dell'oggetto funzione): Oggetti Codice.
                                                             (line    6)
* __code__ (function attribute):         Special writable attributes.
                                                             (line    6)
* __code__ (function attributo):         Special writable attributes.
                                                             (line   36)
* __complex__() (object metodo):         Emulating numeric types.
                                                             (line  124)
* __concat__() (nel modulo operator):    operator — Standard operators as functions.
                                                             (line  188)
* __constraints__ (typing.TypeVar attributo): Building generic types and type aliases.
                                                             (line  196)
* __contains__() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  179)
* __contains__() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  304)
* __contains__() (enum.EnumType metodo): Data Types<2>.      (line   65)
* __contains__() (enum.Flag metodo):     Data Types<2>.      (line  442)
* __contains__() (mailbox.Mailbox metodo): Mailbox objects.  (line  204)
* __contains__() (nel modulo operator):  operator — Standard operators as functions.
                                                             (line  193)
* __contains__() (object metodo):        Emulating container types.
                                                             (line  155)
* __context__ (BaseException attributo): Exception context.  (line    9)
* __context__ (exception attribute):     The raise statement.
                                                             (line   30)
* __context__ (exception attribute) <1>: Exception context.  (line    6)
* __context__ (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line   48)
* __contravariant__ (typing.TypeVar attributo): Building generic types and type aliases.
                                                             (line  163)
* __copy__() (copy protocol):            copy — Shallow and deep copy operations.
                                                             (line   80)
* __covariant__ (typing.TypeVar attributo): Building generic types and type aliases.
                                                             (line  159)
* __debug__:                             The assert statement.
                                                             (line   21)
* __debug__ (variabile built-in):        Built-in Constants. (line   70)
* __deepcopy__() (copy protocol):        copy — Shallow and deep copy operations.
                                                             (line   80)
* __default__ (typing.ParamSpec attributo): Building generic types and type aliases.
                                                             (line  475)
* __default__ (typing.TypeVar attributo): Building generic types and type aliases.
                                                             (line  218)
* __default__ (typing.TypeVarTuple attributo): Building generic types and type aliases.
                                                             (line  362)
* __defaults__ (function attribute):     Special writable attributes.
                                                             (line    6)
* __defaults__ (function attributo):     Special writable attributes.
                                                             (line   30)
* __del__() (io.IOBase metodo):          I/O Base Classes.   (line  164)
* __del__() (object metodo):             Basic customization.
                                                             (line   53)
* __delattr__() (object metodo):         Customizing attribute access.
                                                             (line   69)
* __delete__() (object metodo):          Implementing Descriptors.
                                                             (line   42)
* __delitem__() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  226)
* __delitem__() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  338)
* __delitem__() (mailbox.Mailbox metodo): Mailbox objects.   (line   77)
* __delitem__() (mailbox.MH metodo):     MH objects.         (line   79)
* __delitem__() (nel modulo operator):   operator — Standard operators as functions.
                                                             (line  203)
* __delitem__() (object metodo):         Emulating container types.
                                                             (line  113)
* __dict__ (class attribute):            Special attributes. (line    6)
* __dict__ (function attribute):         Special writable attributes.
                                                             (line    6)
* __dict__ (function attributo):         Special writable attributes.
                                                             (line   40)
* __dict__ (instance attribute):         Special attributes<2>.
                                                             (line    6)
* __dict__ (module attribute):           Module dictionaries.
                                                             (line    8)
* __dict__ (module attribute) <1>:       Module Objects.     (line   49)
* __dict__ (module attributo):           Module dictionaries.
                                                             (line    8)
* __dict__ (object attributo):           Special attributes<2>.
                                                             (line   10)
* __dict__ (type attributo):             Special attributes. (line   22)
* __dir__ (module attribute):            Customizing module attribute access.
                                                             (line    6)
* __dir__() (enum.Enum metodo):          Data Types<2>.      (line  176)
* __dir__() (enum.EnumType metodo):      Data Types<2>.      (line   79)
* __dir__() (module metodo):             Customizing module attribute access.
                                                             (line    6)
* __dir__() (object metodo):             Customizing attribute access.
                                                             (line   78)
* __dir__() (unittest.mock.Mock metodo): The Mock Class.     (line  300)
* __displayhook__ (nel modulo sys):      sys — System-specific parameters and functions.
                                                             (line  420)
* __divmod__() (object metodo):          Emulating numeric types.
                                                             (line   11)
* __doc__ (class attribute):             Special attributes. (line    6)
* __doc__ (definition attributo):        Attributi Speciali. (line   26)
* __doc__ (function attribute):          Special writable attributes.
                                                             (line    6)
* __doc__ (function attributo):          Special writable attributes.
                                                             (line   12)
* __doc__ (method attribute):            Instance methods.   (line    9)
* __doc__ (method attributo):            Instance methods.   (line   18)
* __doc__ (module attribute):            Modules<2>.         (line   21)
* __doc__ (module attribute) <1>:        Module Objects.     (line   26)
* __doc__ (module attributo):            Other writable attributes on module objects.
                                                             (line    9)
* __doc__ (type attributo):              Special attributes. (line   40)
* __enter__() (contextmanager metodo):   Tipi di gestori di contesti.
                                                             (line   13)
* __enter__() (object metodo):           With Statement Context Managers.
                                                             (line   22)
* __enter__() (winreg.PyHKEY metodo):    Registry Handle Objects.
                                                             (line   52)
* __eq__() (email.charset.Charset metodo): email charset Representing character sets.
                                                             (line  150)
* __eq__() (email.header.Header metodo): email header Internationalized headers.
                                                             (line  170)
* __eq__() (memoryview metodo):          Memory Views.       (line  122)
* __eq__() (metodo di istanza):          Confronti.          (line   51)
* __eq__() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line   24)
* __eq__() (object metodo):              Basic customization.
                                                             (line  181)
* __excepthook__ (nel modulo sys):       sys — System-specific parameters and functions.
                                                             (line  420)
* __excepthook__ (nel modulo threading): Reference<2>.       (line   65)
* __exit__() (contextmanager metodo):    Tipi di gestori di contesti.
                                                             (line   34)
* __exit__() (object metodo):            With Statement Context Managers.
                                                             (line   28)
* __exit__() (winreg.PyHKEY metodo):     Registry Handle Objects.
                                                             (line   52)
* __file__ (module attribute):           Modules<2>.         (line   21)
* __file__ (module attribute) <1>:       Module Objects.     (line   26)
* __file__ (module attribute) <2>:       Module Objects.     (line  103)
* __file__ (module attributo):           Import-related attributes on module objects.
                                                             (line  136)
* __firstlineno__ (class attribute):     Special attributes. (line    6)
* __firstlineno__ (type attributo):      Special attributes. (line   93)
* __float__() (object metodo):           Emulating numeric types.
                                                             (line  124)
* __floor__() (fractions.Fraction metodo): fractions — Rational numbers.
                                                             (line  191)
* __floor__() (object metodo):           Emulating numeric types.
                                                             (line  146)
* __floordiv__() (nel modulo operator):  operator — Standard operators as functions.
                                                             (line  100)
* __floordiv__() (object metodo):        Emulating numeric types.
                                                             (line   11)
* __format__:                            Funzioni Incorporate.
                                                             (line  819)
* __format__() (datetime.date metodo):   date Objects.       (line  337)
* __format__() (datetime.datetime metodo): datetime Objects. (line  761)
* __format__() (datetime.time metodo):   time Objects.       (line  245)
* __format__() (enum.Enum metodo):       Data Types<2>.      (line  320)
* __format__() (fractions.Fraction metodo): fractions — Rational numbers.
                                                             (line  218)
* __format__() (ipaddress.IPv4Address metodo): Address objects.
                                                             (line  199)
* __format__() (ipaddress.IPv6Address metodo): Address objects.
                                                             (line  331)
* __format__() (object metodo):          Basic customization.
                                                             (line  153)
* __forward_arg__ (annotationlib.ForwardRef attributo): Classes<4>.
                                                             (line   59)
* __fspath__() (os.PathLike metodo):     Process Parameters. (line  150)
* __func__ (method attribute):           Instance methods.   (line    9)
* __func__ (method attributo):           Instance methods.   (line   15)
* __future__:                            Glossary.           (line  697)
* __future__;future statement:           Future statements.  (line    6)
* __ge__() (metodo di istanza):          Confronti.          (line   51)
* __ge__() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line   24)
* __ge__() (object metodo):              Basic customization.
                                                             (line  181)
* __get__() (object metodo):             Implementing Descriptors.
                                                             (line   15)
* __getattr__ (module attribute):        Customizing module attribute access.
                                                             (line    6)
* __getattr__() (module metodo):         Customizing module attribute access.
                                                             (line    6)
* __getattr__() (object metodo):         Customizing attribute access.
                                                             (line   10)
* __getattribute__() (object metodo):    Customizing attribute access.
                                                             (line   33)
* __getitem__() (email.headerregistry.HeaderRegistry metodo): email headerregistry Custom Header Objects.
                                                             (line  385)
* __getitem__() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  189)
* __getitem__() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  313)
* __getitem__() (enum.EnumType metodo):  Data Types<2>.      (line   87)
* __getitem__() (mailbox.Mailbox metodo): Mailbox objects.   (line  149)
* __getitem__() (mapping object method): Special method names.
                                                             (line    6)
* __getitem__() (nel modulo operator):   operator — Standard operators as functions.
                                                             (line  208)
* __getitem__() (object metodo):         Emulating container types.
                                                             (line   83)
* __getitem__() (re.Match metodo):       Match Objects.      (line   90)
* __getnewargs__() (object metodo):      Pickling Class Instances.
                                                             (line   47)
* __getnewargs_ex__() (object metodo):   Pickling Class Instances.
                                                             (line   29)
* __getstate__() (copy protocol):        Handling Stateful Objects.
                                                             (line    6)
* __getstate__() (object metodo):        Pickling Class Instances.
                                                             (line   61)
* __globals__ (function attribute):      Special read-only attributes.
                                                             (line    6)
* __globals__ (function attributo):      Special read-only attributes.
                                                             (line   16)
* __gt__() (metodo di istanza):          Confronti.          (line   51)
* __gt__() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line   24)
* __gt__() (object metodo):              Basic customization.
                                                             (line  181)
* __hash__() (object metodo):            Basic customization.
                                                             (line  240)
* __iadd__() (nel modulo operator):      In-place Operators. (line   36)
* __iadd__() (object metodo):            Emulating numeric types.
                                                             (line   85)
* __iand__() (nel modulo operator):      In-place Operators. (line   41)
* __iand__() (object metodo):            Emulating numeric types.
                                                             (line   85)
* __iconcat__() (nel modulo operator):   In-place Operators. (line   46)
* __ifloordiv__() (nel modulo operator): In-place Operators. (line   52)
* __ifloordiv__() (object metodo):       Emulating numeric types.
                                                             (line   85)
* __ilshift__() (nel modulo operator):   In-place Operators. (line   57)
* __ilshift__() (object metodo):         Emulating numeric types.
                                                             (line   85)
* __imatmul__() (nel modulo operator):   In-place Operators. (line   72)
* __imatmul__() (object metodo):         Emulating numeric types.
                                                             (line   85)
* __imod__() (nel modulo operator):      In-place Operators. (line   62)
* __imod__() (object metodo):            Emulating numeric types.
                                                             (line   85)
* __import__() (nel modulo importlib):   Functions<12>.      (line    6)
* __imul__() (nel modulo operator):      In-place Operators. (line   67)
* __imul__() (object metodo):            Emulating numeric types.
                                                             (line   85)
* __index__() (nel modulo operator):     operator — Standard operators as functions.
                                                             (line  105)
* __index__() (object metodo):           Emulating numeric types.
                                                             (line  132)
* __infer_variance__ (typing.TypeVar attributo): Building generic types and type aliases.
                                                             (line  168)
* __init__() (asyncio.Future metodo):    Future and Task private constructors.
                                                             (line   17)
* __init__() (asyncio.Task metodo):      Future and Task private constructors.
                                                             (line   23)
* __init__() (difflib.HtmlDiff metodo):  difflib — Helpers for computing deltas.
                                                             (line   92)
* __init__() (enum.Enum metodo):         Data Types<2>.      (line  227)
* __init__() (logging.Handler metodo):   Handler Objects.    (line   13)
* __init__() (logging.logging.Formatter metodo): Formatters. (line   13)
* __init__() (object metodo):            Basic customization.
                                                             (line   37)
* __init_subclass__() (enum.Enum metodo): Data Types<2>.     (line  240)
* __init_subclass__() (object metodo della classe): Customizing class creation.
                                                             (line   13)
* __instancecheck__() (type metodo):     Customizing instance and subclass checks.
                                                             (line   15)
* __int__() (object metodo):             Emulating numeric types.
                                                             (line  124)
* __interactivehook__ (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line 1224)
* __inv__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  114)
* __invert__() (nel modulo operator):    operator — Standard operators as functions.
                                                             (line  114)
* __invert__() (object metodo):          Emulating numeric types.
                                                             (line  116)
* __ior__() (nel modulo operator):       In-place Operators. (line   79)
* __ior__() (object metodo):             Emulating numeric types.
                                                             (line   85)
* __ipow__() (nel modulo operator):      In-place Operators. (line   84)
* __ipow__() (object metodo):            Emulating numeric types.
                                                             (line   85)
* __irshift__() (nel modulo operator):   In-place Operators. (line   89)
* __irshift__() (object metodo):         Emulating numeric types.
                                                             (line   85)
* __isub__() (nel modulo operator):      In-place Operators. (line   94)
* __isub__() (object metodo):            Emulating numeric types.
                                                             (line   85)
* __iter__() (container metodo):         Tipi di Iteratore.  (line   15)
* __iter__() (enum.EnumType metodo):     Data Types<2>.      (line   95)
* __iter__() (iterator metodo):          Tipi di Iteratore.  (line   31)
* __iter__() (mailbox.Mailbox metodo):   Mailbox objects.    (line  117)
* __iter__() (object metodo):            Emulating container types.
                                                             (line  127)
* __iter__() (unittest.TestSuite metodo): Grouping tests.    (line   60)
* __itruediv__() (nel modulo operator):  In-place Operators. (line   99)
* __itruediv__() (object metodo):        Emulating numeric types.
                                                             (line   85)
* __ixor__() (nel modulo operator):      In-place Operators. (line  104)
* __ixor__() (object metodo):            Emulating numeric types.
                                                             (line   85)
* __kwdefaults__ (function attribute):   Special writable attributes.
                                                             (line    6)
* __kwdefaults__ (function attributo):   Special writable attributes.
                                                             (line   62)
* __le__() (metodo di istanza):          Confronti.          (line   51)
* __le__() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line   24)
* __le__() (object metodo):              Basic customization.
                                                             (line  181)
* __len__() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  175)
* __len__() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  300)
* __len__() (enum.EnumType metodo):      Data Types<2>.      (line  102)
* __len__() (mailbox.Mailbox metodo):    Mailbox objects.    (line  209)
* __len__() (mapping object method):     Basic customization.
                                                             (line  324)
* __len__() (object metodo):             Emulating container types.
                                                             (line   44)
* __length_hint__() (object metodo):     Emulating container types.
                                                             (line   59)
* __loader__ (module attribute):         Modules<2>.         (line   21)
* __loader__ (module attribute) <1>:     Module Objects.     (line   26)
* __loader__ (module attributo):         Import-related attributes on module objects.
                                                             (line   98)
* __lshift__() (nel modulo operator):    operator — Standard operators as functions.
                                                             (line  122)
* __lshift__() (object metodo):          Emulating numeric types.
                                                             (line   11)
* __lt__() (metodo di istanza):          Confronti.          (line   51)
* __lt__() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line   24)
* __lt__() (object metodo):              Basic customization.
                                                             (line  181)
* __matmul__() (nel modulo operator):    operator — Standard operators as functions.
                                                             (line  137)
* __matmul__() (object metodo):          Emulating numeric types.
                                                             (line   11)
* __members__ (enum.EnumType attributo): Data Types<2>.      (line  109)
* __missing__():                         Tipi di Mapping — dict.
                                                             (line  118)
* __missing__() (collections.defaultdict metodo): defaultdict objects.
                                                             (line   22)
* __missing__() (object metodo):         Emulating container types.
                                                             (line  122)
* __mod__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  127)
* __mod__() (object metodo):             Emulating numeric types.
                                                             (line   11)
* __module__ (class attribute):          Special attributes. (line    6)
* __module__ (definition attributo):     Attributi Speciali. (line   22)
* __module__ (function attribute):       Special writable attributes.
                                                             (line    6)
* __module__ (function attributo):       Special writable attributes.
                                                             (line   26)
* __module__ (method attribute):         Instance methods.   (line    9)
* __module__ (method attributo):         Instance methods.   (line   28)
* __module__ (type attributo):           Special attributes. (line   18)
* __module__ (typing.NewType attributo): Other special directives.
                                                             (line  125)
* __module__ (typing.TypeAliasType attributo): Building generic types and type aliases.
                                                             (line  573)
* __mro__ (type attributo):              Special attributes. (line  101)
* __mro_entries__() (object metodo):     Resolving MRO entries.
                                                             (line    6)
* __mul__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  132)
* __mul__() (object metodo):             Emulating numeric types.
                                                             (line   11)
* __mutable_keys__ (typing.TypedDict attributo): Other special directives.
                                                             (line  465)
* __name__ (class attribute):            Special attributes. (line    6)
* __name__ (definition attributo):       Attributi Speciali. (line   10)
* __name__ (function attribute):         Special writable attributes.
                                                             (line    6)
* __name__ (function attributo):         Special writable attributes.
                                                             (line   16)
* __name__ (method attribute):           Instance methods.   (line    9)
* __name__ (method attributo):           Instance methods.   (line   24)
* __name__ (module attribute):           Modules<2>.         (line   21)
* __name__ (module attribute) <1>:       Module Objects.     (line   26)
* __name__ (module attribute) <2>:       Module Objects.     (line   67)
* __name__ (module attributo):           Import-related attributes on module objects.
                                                             (line   37)
* __name__ (property attributo):         Funzioni Incorporate.
                                                             (line 1756)
* __name__ (type attributo):             Special attributes. (line   10)
* __name__ (typing.NewType attributo):   Other special directives.
                                                             (line  129)
* __name__ (typing.ParamSpec attributo): Building generic types and type aliases.
                                                             (line  471)
* __name__ (typing.TypeAliasType attributo): Building generic types and type aliases.
                                                             (line  565)
* __name__ (typing.TypeVar attributo):   Building generic types and type aliases.
                                                             (line  155)
* __name__ (typing.TypeVarTuple attributo): Building generic types and type aliases.
                                                             (line  358)
* __ne__() (email.charset.Charset metodo): email charset Representing character sets.
                                                             (line  155)
* __ne__() (email.header.Header metodo): email header Internationalized headers.
                                                             (line  175)
* __ne__() (metodo di istanza):          Confronti.          (line   51)
* __ne__() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line   24)
* __ne__() (object metodo):              Basic customization.
                                                             (line  181)
* __neg__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  144)
* __neg__() (object metodo):             Emulating numeric types.
                                                             (line  116)
* __new__() (enum.Enum metodo):          Data Types<2>.      (line  268)
* __new__() (object metodo):             Basic customization.
                                                             (line    6)
* __new__() (string.templatelib.Interpolation metodo): Types.
                                                             (line  280)
* __new__() (string.templatelib.Template metodo): Types.     (line  106)
* __next__() (csv.csvreader metodo):     Reader Objects.     (line    9)
* __next__() (generator metodo):         Generator-iterator methods.
                                                             (line   12)
* __next__() (iterator metodo):          Tipi di Iteratore.  (line   39)
* __not__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line   49)
* __notes__ (BaseException attributo):   Base classes.       (line   58)
* __notes__ (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line   66)
* __objclass__ (object attributo):       Implementing Descriptors.
                                                             (line   50)
* __optional_keys__ (typing.TypedDict attributo): Other special directives.
                                                             (line  416)
* __or__() (enum.Flag metodo):           Data Types<2>.      (line  497)
* __or__() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line  149)
* __or__() (object metodo):              Emulating numeric types.
                                                             (line   11)
* __origin__ (genericalias attributo):   Attributi Speciali per oggetti GenericAlias.
                                                             (line    9)
* __package__ (module attribute):        Modules<2>.         (line   21)
* __package__ (module attribute) <1>:    Module Objects.     (line   26)
* __package__ (module attributo):        Import-related attributes on module objects.
                                                             (line   55)
* __parameters__ (genericalias attributo): Attributi Speciali per oggetti GenericAlias.
                                                             (line   25)
* __path__ (module attribute):           Modules<2>.         (line   21)
* __path__ (module attributo):           Import-related attributes on module objects.
                                                             (line  125)
* __pointer_type__ (ctypes._CData attributo): Data types.    (line   71)
* __pos__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  154)
* __pos__() (object metodo):             Emulating numeric types.
                                                             (line  116)
* __post_init__() (nel modulo dataclasses): Post-init processing.
                                                             (line    6)
* __pow__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  159)
* __pow__() (object metodo):             Emulating numeric types.
                                                             (line   11)
* __prepare__ (metaclass method):        Preparing the class namespace.
                                                             (line    6)
* __PYVENV_LAUNCHER__:                   PyConfig.           (line  187)
* __PYVENV_LAUNCHER__ <1>:               PyConfig.           (line  731)
* __qualname__ (definition attributo):   Attributi Speciali. (line   15)
* __qualname__ (function attributo):     Special writable attributes.
                                                             (line   20)
* __qualname__ (type attributo):         Special attributes. (line   14)
* __radd__() (object metodo):            Emulating numeric types.
                                                             (line   42)
* __rand__() (object metodo):            Emulating numeric types.
                                                             (line   42)
* __rdivmod__() (object metodo):         Emulating numeric types.
                                                             (line   42)
* __readonly_keys__ (typing.TypedDict attributo): Other special directives.
                                                             (line  457)
* __reduce__() (object metodo):          Pickling Class Instances.
                                                             (line  124)
* __reduce_ex__() (object metodo):       Pickling Class Instances.
                                                             (line  180)
* __release_buffer__() (object metodo):  Emulating buffer types.
                                                             (line   25)
* __replace__() (replace protocol):      copy — Shallow and deep copy operations.
                                                             (line   98)
* __repr__() (enum.Enum metodo):         Data Types<2>.      (line  285)
* __repr__() (multiprocessing.managers.BaseProxy metodo): Proxy Objects.
                                                             (line  145)
* __repr__() (netrc.netrc metodo):       netrc Objects.      (line   16)
* __repr__() (object metodo):            Basic customization.
                                                             (line  114)
* __required_keys__ (typing.TypedDict attributo): Other special directives.
                                                             (line  412)
* __reversed__() (enum.EnumType metodo): Data Types<2>.      (line  114)
* __reversed__() (object metodo):        Emulating container types.
                                                             (line  134)
* __rfloordiv__() (object metodo):       Emulating numeric types.
                                                             (line   42)
* __rlshift__() (object metodo):         Emulating numeric types.
                                                             (line   42)
* __rmatmul__() (object metodo):         Emulating numeric types.
                                                             (line   42)
* __rmod__() (object metodo):            Emulating numeric types.
                                                             (line   42)
* __rmul__() (object metodo):            Emulating numeric types.
                                                             (line   42)
* __ror__() (object metodo):             Emulating numeric types.
                                                             (line   42)
* __round__() (fractions.Fraction metodo): fractions — Rational numbers.
                                                             (line  207)
* __round__() (object metodo):           Emulating numeric types.
                                                             (line  146)
* __rpow__() (object metodo):            Emulating numeric types.
                                                             (line   42)
* __rrshift__() (object metodo):         Emulating numeric types.
                                                             (line   42)
* __rshift__() (nel modulo operator):    operator — Standard operators as functions.
                                                             (line  164)
* __rshift__() (object metodo):          Emulating numeric types.
                                                             (line   11)
* __rsub__() (object metodo):            Emulating numeric types.
                                                             (line   42)
* __rtruediv__() (object metodo):        Emulating numeric types.
                                                             (line   42)
* __rxor__() (object metodo):            Emulating numeric types.
                                                             (line   42)
* __self__ (method attribute):           Instance methods.   (line    9)
* __self__ (method attributo):           Instance methods.   (line   11)
* __set__() (object metodo):             Implementing Descriptors.
                                                             (line   33)
* __set_name__() (object metodo):        Customizing class creation.
                                                             (line   47)
* __setattr__() (object metodo):         Customizing attribute access.
                                                             (line   54)
* __setitem__() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  204)
* __setitem__() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  324)
* __setitem__() (mailbox.Mailbox metodo): Mailbox objects.   (line   91)
* __setitem__() (mailbox.Maildir metodo): Maildir objects.   (line  193)
* __setitem__() (nel modulo operator):   operator — Standard operators as functions.
                                                             (line  217)
* __setitem__() (object metodo):         Emulating container types.
                                                             (line  104)
* __setstate__() (copy protocol):        Handling Stateful Objects.
                                                             (line    6)
* __setstate__() (object metodo):        Pickling Class Instances.
                                                             (line   88)
* __slots__:                             Glossary.           (line 1554)
* __spec__ (module attribute):           Modules<2>.         (line   21)
* __spec__ (module attributo):           Import-related attributes on module objects.
                                                             (line   46)
* __static_attributes__ (class attribute): Special attributes.
                                                             (line    6)
* __static_attributes__ (type attributo): Special attributes.
                                                             (line   86)
* __stderr__ (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line 2055)
* __stdin__ (nel modulo sys):            sys — System-specific parameters and functions.
                                                             (line 2055)
* __stdout__ (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line 2055)
* __str__() (datetime.date metodo):      date Objects.       (line  310)
* __str__() (datetime.datetime metodo):  datetime Objects.   (line  731)
* __str__() (datetime.time metodo):      time Objects.       (line  235)
* __str__() (email.charset.Charset metodo): email charset Representing character sets.
                                                             (line  145)
* __str__() (email.header.Header metodo): email header Internationalized headers.
                                                             (line  158)
* __str__() (email.headerregistry.Address metodo): email headerregistry Custom Header Objects.
                                                             (line  447)
* __str__() (email.headerregistry.Group metodo): email headerregistry Custom Header Objects.
                                                             (line  482)
* __str__() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line   95)
* __str__() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  102)
* __str__() (enum.Enum metodo):          Data Types<2>.      (line  303)
* __str__() (multiprocessing.managers.BaseProxy metodo): Proxy Objects.
                                                             (line  149)
* __str__() (object metodo):             Basic customization.
                                                             (line  131)
* __sub__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  169)
* __sub__() (object metodo):             Emulating numeric types.
                                                             (line   11)
* __subclasscheck__() (type metodo):     Customizing instance and subclass checks.
                                                             (line   21)
* __subclasses__() (type metodo):        Special methods.    (line   15)
* __subclasshook__() (abc.ABCMeta metodo): abc — Abstract Base Classes.
                                                             (line   92)
* __supertype__ (typing.NewType attributo): Other special directives.
                                                             (line  133)
* __suppress_context__ (BaseException attributo): Exception context.
                                                             (line    9)
* __suppress_context__ (exception attribute): Exception context.
                                                             (line    6)
* __suppress_context__ (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line   61)
* __test__ (module attributo):           Which Docstrings Are Examined?.
                                                             (line    9)
* __total__ (typing.TypedDict attributo): Other special directives.
                                                             (line  387)
* __traceback__ (BaseException attributo): Base classes.     (line   44)
* __traceback__ (exception attribute):   The raise statement.
                                                             (line    6)
* __truediv__() (importlib.resources.abc.Traversable metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line  139)
* __truediv__() (nel modulo operator):   operator — Standard operators as functions.
                                                             (line  174)
* __truediv__() (object metodo):         Emulating numeric types.
                                                             (line   11)
* __trunc__() (object metodo):           Emulating numeric types.
                                                             (line  146)
* __type_params__ (class attribute):     Special attributes. (line    6)
* __type_params__ (definition attributo): Attributi Speciali.
                                                             (line   31)
* __type_params__ (function attribute):  Special writable attributes.
                                                             (line    6)
* __type_params__ (function attributo):  Special writable attributes.
                                                             (line   66)
* __type_params__ (type attributo):      Special attributes. (line   79)
* __type_params__ (typing.TypeAliasType attributo): Building generic types and type aliases.
                                                             (line  581)
* __unpacked__ (genericalias attributo): Attributi Speciali per oggetti GenericAlias.
                                                             (line   41)
* __unraisablehook__ (nel modulo sys):   sys — System-specific parameters and functions.
                                                             (line  420)
* __value__ (typing.TypeAliasType attributo): Building generic types and type aliases.
                                                             (line  593)
* __xor__() (enum.Flag metodo):          Data Types<2>.      (line  513)
* __xor__() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  180)
* __xor__() (object metodo):             Emulating numeric types.
                                                             (line   11)
* _, identifiers:                        Soft Keywords.      (line   25)
* _add_alias_() (enum.Enum metodo):      Data Types<2>.      (line  342)
* _add_value_alias_() (enum.Enum metodo): Data Types<2>.     (line  355)
* _align_ (ctypes.Structure attributo):  Structured data types.
                                                             (line  111)
* _anonymous_ (ctypes.Structure attributo): Structured data types.
                                                             (line  163)
* _asdict() (collections.somenamedtuple metodo): namedtuple Factory Function for Tuples with Named Fields.
                                                             (line  110)
* _b_base_ (ctypes._CData attributo):    Data types.         (line   81)
* _b_needsfree_ (ctypes._CData attributo): Data types.       (line   88)
* _callmethod() (multiprocessing.managers.BaseProxy metodo): Proxy Objects.
                                                             (line   96)
* _CData (classe in ctypes):             Data types.         (line    6)
* _CFuncPtr (classe in ctypes):          Foreign functions.  (line   22)
* _clear_internal_caches() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line  194)
* _clear_type_cache() (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line  182)
* _current_exceptions() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line  222)
* _current_frames() (nel modulo sys):    sys — System-specific parameters and functions.
                                                             (line  202)
* _debugmallocstats() (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line  278)
* _emscripten_info (nel modulo sys):     sys — System-specific parameters and functions.
                                                             (line  343)
* _enablelegacywindowsfsencoding() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line 1961)
* _enter_task() (nel modulo asyncio):    Task lifetime support.
                                                             (line   22)
* _exit() (nel modulo os):               Process Management. (line  123)
* _Feature (classe in __future__):       Module Contents<5>. (line   54)
* _field_defaults (collections.somenamedtuple attributo): namedtuple Factory Function for Tuples with Named Fields.
                                                             (line  159)
* _field_types (ast.AST attributo):      Node classes.       (line   39)
* _fields (ast.AST attributo):           Node classes.       (line   22)
* _fields (collections.somenamedtuple attributo): namedtuple Factory Function for Tuples with Named Fields.
                                                             (line  146)
* _fields_ (ctypes.Structure attributo): Structured data types.
                                                             (line   46)
* _flush() (wsgiref.handlers.BaseHandler metodo): wsgiref handlers – server/gateway base classes.
                                                             (line  117)
* _for_archive() (zipfile.ZipInfo metodo): zipfile — Work with ZIP archives.
                                                             (line   83)
* _frozen (C struct):                    Importing Modules<2>.
                                                             (line  275)
* _generate_next_value_() (enum.Enum metodo): Data Types<2>. (line  198)
* _get_child_mock() (unittest.mock.Mock metodo): The Mock Class.
                                                             (line  309)
* _get_preferred_schemes() (nel modulo sysconfig): Installation path functions.
                                                             (line   41)
* _getframe() (nel modulo sys):          sys — System-specific parameters and functions.
                                                             (line  916)
* _getframemodulename() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line  931)
* _getvalue() (multiprocessing.managers.BaseProxy metodo): Proxy Objects.
                                                             (line  138)
* _handle (ctypes.PyDLL attributo):      Loading shared libraries.
                                                             (line  157)
* _ignore_ (enum.Enum attributo):        Data Types<2>.      (line  167)
* _incompatible_extension_module_restrictions() (nel modulo importlib.util): importlib util – Utility code for importers.
                                                             (line  168)
* _inittab (C struct):                   Importing Modules<2>.
                                                             (line  312)
* _inittab.initfunc (C member):          Importing Modules<2>.
                                                             (line  324)
* _inittab.name (C member):              Importing Modules<2>.
                                                             (line  320)
* _is_gil_enabled() (nel modulo sys):    sys — System-specific parameters and functions.
                                                             (line 1254)
* _is_immortal() (nel modulo sys):       sys — System-specific parameters and functions.
                                                             (line 1342)
* _is_interned() (nel modulo sys):       sys — System-specific parameters and functions.
                                                             (line 1358)
* _jit (nel modulo sys):                 sys — System-specific parameters and functions.
                                                             (line 1273)
* _jit.is_active() (nel modulo sys):     sys — System-specific parameters and functions.
                                                             (line 1301)
* _jit.is_available() (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line 1284)
* _jit.is_enabled() (nel modulo sys):    sys — System-specific parameters and functions.
                                                             (line 1292)
* _layout_ (ctypes.Structure attributo): Structured data types.
                                                             (line  132)
* _leave_task() (nel modulo asyncio):    Task lifetime support.
                                                             (line   30)
* _length_ (ctypes.Array attributo):     Arrays and pointers.
                                                             (line   18)
* _log (logging.LoggerAdapter attributo): LoggerAdapter Objects.
                                                             (line   36)
* _make() (collections.somenamedtuple metodo della classe): namedtuple Factory Function for Tuples with Named Fields.
                                                             (line  101)
* _makeResult() (unittest.TextTestRunner metodo): Loading and running tests.
                                                             (line  494)
* _missing_() (enum.Enum metodo):        Data Types<2>.      (line  245)
* _name (ctypes.PyDLL attributo):        Loading shared libraries.
                                                             (line  161)
* _name_ (enum.Enum attributo):          Data Types<2>.      (line  154)
* _numeric_repr_() (enum.Flag metodo):   Data Types<2>.      (line  533)
* _objects (ctypes._CData attributo):    Data types.         (line   93)
* _order_ (enum.Enum attributo):         Data Types<2>.      (line  162)
* _pack_ (ctypes.Structure attributo):   Structured data types.
                                                             (line   87)
* _parse() (gettext.NullTranslations metodo): The NullTranslations class.
                                                             (line   21)
* _Pointer (classe in ctypes):           Arrays and pointers.
                                                             (line   39)
* _Py_c_diff (C function):               Complex Numbers as C Structures.
                                                             (line   33)
* _Py_c_neg (C function):                Complex Numbers as C Structures.
                                                             (line   39)
* _Py_c_pow (C function):                Complex Numbers as C Structures.
                                                             (line   59)
* _Py_c_prod (C function):               Complex Numbers as C Structures.
                                                             (line   44)
* _Py_c_quot (C function):               Complex Numbers as C Structures.
                                                             (line   50)
* _Py_c_sum (C function):                Complex Numbers as C Structures.
                                                             (line   27)
* _Py_NoneStruct (C var):                Allocating Objects on the Heap.
                                                             (line  143)
* _Py_TPFLAGS_HAVE_VECTORCALL (C macro): PyTypeObject Slots. (line  842)
* _PyBytes_Resize (C function):          Bytes Objects.      (line  201)
* _PyCode_GetExtra (C function):         Extra information.  (line   35)
* _PyCode_SetExtra (C function):         Extra information.  (line   51)
* _PyEval_RequestCodeExtraIndex (C function): Extra information.
                                                             (line   14)
* _PyFrameEvalFunction (C type):         Low-level API.      (line  219)
* _PyInterpreterFrame (C struct):        Internal Frames.    (line    8)
* _PyInterpreterState_GetEvalFrameFunc (C function): Low-level API.
                                                             (line  234)
* _PyInterpreterState_SetEvalFrameFunc (C function): Low-level API.
                                                             (line  244)
* _PyObject_GetDictPtr (C function):     Object Protocol.    (line  287)
* _PyObject_New (C function):            Allocating Objects on the Heap.
                                                             (line    6)
* _PyObject_NewVar (C function):         Allocating Objects on the Heap.
                                                             (line    9)
* _PyObject_Vectorcall (C function):     Object Calling API. (line  199)
* _PyTuple_Resize (C function):          Tuple Objects.      (line  106)
* _register_task() (nel modulo asyncio): Task lifetime support.
                                                             (line   10)
* _replace() (collections.somenamedtuple metodo): namedtuple Factory Function for Tuples with Named Fields.
                                                             (line  128)
* _setroot() (xml.etree.ElementTree.ElementTree metodo): ElementTree Objects.
                                                             (line   15)
* _SimpleCData (classe in ctypes):       Fundamental data types<2>.
                                                             (line    6)
* _structure() (nel modulo email.iterators): email iterators Iterators.
                                                             (line   44)
* _type_ (ctypes._Pointer attributo):    Arrays and pointers.
                                                             (line   54)
* _type_ (ctypes.Array attributo):       Arrays and pointers.
                                                             (line   24)
* _unregister_task() (nel modulo asyncio): Task lifetime support.
                                                             (line   16)
* _value_ (enum.Enum attributo):         Data Types<2>.      (line  158)
* _write() (wsgiref.handlers.BaseHandler metodo): wsgiref handlers – server/gateway base classes.
                                                             (line  109)
* _xoptions (nel modulo sys):            sys — System-specific parameters and functions.
                                                             (line 2241)
* - (meno);nella formattazione stile printf: Formattazione delle stringhe in stile printf.
                                                             (line   71)
* - (meno);nella formattazione stile printf <1>: Formattazione Bytes stile printf.
                                                             (line   65)
* - (meno);operatore binario:            Tipi Numerici — int float complex.
                                                             (line   30)
* - (meno);operatore unario:             Tipi Numerici — int float complex.
                                                             (line   30)
* - (minus);binary operator:             Binary arithmetic operations.
                                                             (line   89)
* - (minus);in doctests:                 Option Flags.       (line  164)
* - (minus);in glob-style wildcards:     glob — Unix style pathname pattern expansion.
                                                             (line   10)
* - (minus);in glob-style wildcards <1>: fnmatch — Unix filename pattern matching.
                                                             (line   15)
* - (minus);in regular expressions:      Regular Expression Syntax.
                                                             (line  178)
* - (minus);in string formatting:        Format Specification Mini-Language.
                                                             (line   77)
* - (minus);unary operator:              Unary arithmetic and bitwise operations.
                                                             (line   10)
* -=;augmented assignment:               Augmented assignment statements.
                                                             (line    6)
* ->;annotazioni delle funzioni:         Annotationi delle Funzioni.
                                                             (line    6)
* ->;function annotations:               Function definitions.
                                                             (line  111)
* , (comma):                             Parenthesized forms.
                                                             (line   20)
* , (comma);argument list:               Slicings.           (line   39)
* , (comma);expression list:             List displays.      (line    6)
* , (comma);expression list <1>:         Set displays.       (line    6)
* , (comma);expression list <2>:         Expression lists.   (line    6)
* , (comma);expression list <3>:         The assert statement.
                                                             (line    6)
* , (comma);expression list <4>:         Class definitions.  (line    6)
* , (comma);identifier list:             The global statement.
                                                             (line    6)
* , (comma);identifier list <1>:         The nonlocal statement.
                                                             (line    6)
* , (comma);import statement:            The import statement.
                                                             (line    6)
* , (comma);in dictionary displays:      Dictionary displays.
                                                             (line    6)
* , (comma);in string formatting:        Format Specification Mini-Language.
                                                             (line  136)
* , (comma);in target list:              Assignment statements.
                                                             (line   35)
* , (comma);parameter list:              Function definitions.
                                                             (line    6)
* , (comma);slicing:                     Slicings.           (line    6)
* , (comma);with statement:              The with statement. (line    6)
* ; (colon);annotated variable:          Annotated assignment statements.
                                                             (line    6)
* ; (colon);compound statement:          The if statement.   (line    6)
* ; (colon);compound statement <1>:      The while statement.
                                                             (line    6)
* ; (colon);compound statement <2>:      The for statement.  (line    6)
* ; (colon);compound statement <3>:      The try statement.  (line    6)
* ; (colon);compound statement <4>:      The with statement. (line    6)
* ; (colon);compound statement <5>:      The match statement.
                                                             (line    6)
* ; (colon);compound statement <6>:      Function definitions.
                                                             (line    6)
* ; (colon);compound statement <7>:      Class definitions.  (line    6)
* ; (colon);function annotations:        Function definitions.
                                                             (line  111)
* ; (colon);in dictionary expressions:   Dictionary displays.
                                                             (line    6)
* ; (colon);in formatted string literal: Raw string literals.
                                                             (line   25)
* ; (colon);in formatted string literal <1>: Metodi per le Stringhe.
                                                             (line  912)
* ; (colon);in SQL statements:           Cursor objects.     (line   24)
* ; (colon);in string formatting:        Format String Syntax.
                                                             (line   14)
* ; (colon);lambda expression:           Lambdas.            (line    6)
* ; (colon);path separator (POSIX):      Miscellaneous System Information.
                                                             (line  138)
* ; (colon);slicing:                     Slicings.           (line    6)
* ; (due punti);annotazioni delle funzioni: Annotationi delle Funzioni.
                                                             (line    6)
* ; (semicolon):                         Compound statements.
                                                             (line   18)
* ; (semicolon) <1>:                     Miscellaneous System Information.
                                                             (line  138)
* ;= (colon equals):                     Boolean operations. (line   38)
* ! (exclamation mark);in formatted string literal: Metodi per le Stringhe.
                                                             (line  912)
* ! (exclamation);in a command interpreter: Cmd Objects.     (line   27)
* ! (exclamation);in curses module:      curses ascii — Utilities for ASCII characters.
                                                             (line  229)
* ! (exclamation);in formatted string literal: Raw string literals.
                                                             (line   25)
* ! (exclamation);in glob-style wildcards: glob — Unix style pathname pattern expansion.
                                                             (line   10)
* ! (exclamation);in glob-style wildcards <1>: fnmatch — Unix filename pattern matching.
                                                             (line   15)
* ! (exclamation);in string formatting:  Format String Syntax.
                                                             (line   14)
* ! (exclamation);in struct format strings: Byte Order Size and Alignment.
                                                             (line   13)
* ! (pdb command):                       Debugger commands.  (line  413)
* ! f-string:                            Metodi per le Stringhe.
                                                             (line  912)
* ! formatted string literal:            Metodi per le Stringhe.
                                                             (line  912)
* ! patterns:                            Patterns.           (line    6)
* ? (question mark);in a command interpreter: Cmd Objects.   (line   27)
* ? (question mark);in argparse module:  nargs.              (line   24)
* ? (question mark);in AST grammar:      Node classes.       (line   22)
* ? (question mark);in glob-style wildcards: glob — Unix style pathname pattern expansion.
                                                             (line   10)
* ? (question mark);in glob-style wildcards <1>: fnmatch — Unix filename pattern matching.
                                                             (line   15)
* ? (question mark);in regular expressions: Regular Expression Syntax.
                                                             (line   81)
* ? (question mark);in SQL statements:   Cursor objects.     (line   24)
* ? (question mark);in struct format strings: Format Characters.
                                                             (line   96)
* ? (question mark);in struct format strings <1>: Format Characters.
                                                             (line  187)
* ? (question mark);replacement character: Error Handlers.   (line   15)
* ??;in regular expressions:             Regular Expression Syntax.
                                                             (line   86)
* ?+;in regular expressions:             Regular Expression Syntax.
                                                             (line   96)
* . (dot);attribute reference:           Attribute references.
                                                             (line    6)
* . (dot);in glob-style wildcards:       glob — Unix style pathname pattern expansion.
                                                             (line   10)
* . (dot);in numeric literal:            Integer literals.   (line   65)
* . (dot);in pathnames:                  Miscellaneous System Information.
                                                             (line  104)
* . (dot);in pathnames <1>:              Miscellaneous System Information.
                                                             (line  132)
* . (dot);in regular expressions:        Regular Expression Syntax.
                                                             (line   46)
* . (dot);in string formatting:          Format String Syntax.
                                                             (line   14)
* . (punto);nella formattazione stile printf: Formattazione delle stringhe in stile printf.
                                                             (line   31)
* . (punto);nella formattazione stile printf <1>: Formattazione Bytes stile printf.
                                                             (line   25)
* ..;in pathnames:                       Miscellaneous System Information.
                                                             (line  110)
* ...:                                   Glossary.           (line   10)
* ...;ellipsis literal:                  else Clauses on Loops.
                                                             (line   57)
* ...;ellipsis literal <1>:              Ellipsis.           (line    6)
* ...;ellipsis literal <2>:              Built-in Constants. (line   62)
* ...;ellipsis literal <3>:              Annotating callable objects.
                                                             (line   28)
* ...;ellipsis literal <4>:              Annotating tuples.  (line   42)
* ...;ellipsis literal <5>:              Special forms.      (line   85)
* ...;ellipsis literal <6>:              Glossary.           (line   22)
* ...;in doctests:                       Option Flags.       (line   47)
* ...;interpreter prompt:                How are Docstring Examples Recognized?.
                                                             (line   26)
* ...;interpreter prompt <1>:            sys — System-specific parameters and functions.
                                                             (line 1624)
* ...;letterale ellissi:                 L’Oggetto Null.     (line   12)
* ...;placeholder:                       textwrap — Text wrapping and filling.
                                                             (line  282)
* ...;placeholder <1>:                   PrettyPrinter Objects.
                                                             (line    6)
* ...;placeholder <2>:                   reprlib — Alternate repr implementation.
                                                             (line   61)
* .ini;file:                             configparser — Configuration file parser.
                                                             (line    8)
* .pdbrc;file:                           Debugger commands.  (line   63)
* ' (single quote);string literal:       Literals.           (line   15)
* ''';string literal:                    String and Bytes literals.
                                                             (line   33)
* " (double quote);string literal:       Literals.           (line   14)
* """;string literal:                    String and Bytes literals.
                                                             (line   33)
* (?;;in regular expressions:            Regular Expression Syntax.
                                                             (line  287)
* (?;in regular expressions:             Regular Expression Syntax.
                                                             (line  248)
* (?!;in regular expressions:            Regular Expression Syntax.
                                                             (line  405)
* (?(;in regular expressions:            Regular Expression Syntax.
                                                             (line  448)
* (?#;in regular expressions:            Regular Expression Syntax.
                                                             (line  394)
* (?<!;in regular expressions:           Regular Expression Syntax.
                                                             (line  439)
* (?<=;in regular expressions:           Regular Expression Syntax.
                                                             (line  411)
* (?=;in regular expressions:            Regular Expression Syntax.
                                                             (line  398)
* (?P<;in regular expressions:           Regular Expression Syntax.
                                                             (line  350)
* (?P=;in regular expressions:           Regular Expression Syntax.
                                                             (line  389)
* () (parentesi);nella formattazione stile printf: Formattazione delle stringhe in stile printf.
                                                             (line   31)
* () (parentesi);nella formattazione stile printf <1>: Formattazione Bytes stile printf.
                                                             (line   25)
* () (parentheses);call:                 Slicings.           (line   39)
* () (parentheses);class definition:     Class definitions.  (line    6)
* () (parentheses);function definition:  Function definitions.
                                                             (line    6)
* () (parentheses);generator expression: Generator expressions.
                                                             (line    6)
* () (parentheses);in assignment target list: Assignment statements.
                                                             (line   35)
* () (parentheses);in regular expressions: Regular Expression Syntax.
                                                             (line  239)
* () (parentheses);tuple display:        Parenthesized forms.
                                                             (line    6)
* [] (square brackets);in assignment target list: Assignment statements.
                                                             (line   35)
* [] (square brackets);in glob-style wildcards: glob — Unix style pathname pattern expansion.
                                                             (line   10)
* [] (square brackets);in glob-style wildcards <1>: fnmatch — Unix filename pattern matching.
                                                             (line   15)
* [] (square brackets);in regular expressions: Regular Expression Syntax.
                                                             (line  171)
* [] (square brackets);in string formatting: Format String Syntax.
                                                             (line   14)
* [] (square brackets);list expression:  List displays.      (line    6)
* [] (square brackets);subscription:     Subscriptions.      (line    6)
* {} (curly brackets);dictionary expression: Dictionary displays.
                                                             (line    6)
* {} (curly brackets);in formatted string literal: Raw string literals.
                                                             (line   25)
* {} (curly brackets);in formatted string literal <1>: Metodi per le Stringhe.
                                                             (line  912)
* {} (curly brackets);in regular expressions: Regular Expression Syntax.
                                                             (line  115)
* {} (curly brackets);in string formatting: Format String Syntax.
                                                             (line   14)
* {} (curly brackets);set expression:    Set displays.       (line    6)
* @ (at);class definition:               Class definitions.  (line   44)
* @ (at);function definition:            Function definitions.
                                                             (line   35)
* @ (at);in struct format strings:       Byte Order Size and Alignment.
                                                             (line   13)
* * (asterisco);nella formattazione stile printf: Formattazione delle stringhe in stile printf.
                                                             (line   31)
* * (asterisco);nella formattazione stile printf <1>: Formattazione Bytes stile printf.
                                                             (line   25)
* * (asterisco);nelle chiamate di funzione: Liste di Argomenti Arbitrarie.
                                                             (line    6)
* * (asterisk);function definition:      Function definitions.
                                                             (line   94)
* * (asterisk);import statement:         The import statement.
                                                             (line   80)
* * (asterisk);in argparse module:       nargs.              (line   55)
* * (asterisk);in assignment target list: Assignment statements.
                                                             (line   35)
* * (asterisk);in AST grammar:           Node classes.       (line   22)
* * (asterisk);in expression lists:      Expression lists.   (line   18)
* * (asterisk);in function calls:        Calls.              (line   73)
* * (asterisk);in glob-style wildcards:  glob — Unix style pathname pattern expansion.
                                                             (line   10)
* * (asterisk);in glob-style wildcards <1>: fnmatch — Unix filename pattern matching.
                                                             (line   15)
* * (asterisk);in regular expressions:   Regular Expression Syntax.
                                                             (line   69)
* *?;in regular expressions:             Regular Expression Syntax.
                                                             (line   86)
* **;function definition:                Function definitions.
                                                             (line   94)
* **;in dictionary displays:             Dictionary displays.
                                                             (line   23)
* **;in function calls:                  Calls.              (line  100)
* **;in glob-style wildcards:            glob — Unix style pathname pattern expansion.
                                                             (line   51)
* **;nelle chiamate di funzione:         Spacchettamento delle Liste di Argomenti.
                                                             (line   20)
* **=;augmented assignment:              Augmented assignment statements.
                                                             (line    6)
* *+;in regular expressions:             Regular Expression Syntax.
                                                             (line   96)
* *=;augmented assignment:               Augmented assignment statements.
                                                             (line    6)
* / (slash);function definition:         Function definitions.
                                                             (line   94)
* / (slash);in pathnames:                Miscellaneous System Information.
                                                             (line  116)
* / (slash);in pathnames <1>:            Miscellaneous System Information.
                                                             (line  125)
* //=;augmented assignment:              Augmented assignment statements.
                                                             (line    6)
* /=;augmented assignment:               Augmented assignment statements.
                                                             (line    6)
* \ (backslash);escape sequence:         Formal grammar.     (line   28)
* \ (backslash);escape sequence <1>:     Error Handlers.     (line   15)
* \ (backslash);in pathnames (Windows):  Miscellaneous System Information.
                                                             (line  116)
* \ (backslash);in regular expressions:  Regular Expression Syntax.
                                                             (line  156)
* \ (backslash);in regular expressions <1>: Regular Expression Syntax.
                                                             (line  190)
* \ (backslash);in regular expressions <2>: Regular Expression Syntax.
                                                             (line  467)
* \\;escape sequence:                    Formal grammar.     (line   28)
* \\;in regular expressions:             Regular Expression Syntax.
                                                             (line  597)
* \a;escape sequence:                    Formal grammar.     (line   28)
* \A;in regular expressions:             Regular Expression Syntax.
                                                             (line  479)
* \a;in regular expressions:             Regular Expression Syntax.
                                                             (line  597)
* \b;escape sequence:                    Formal grammar.     (line   28)
* \b;in regular expressions:             Regular Expression Syntax.
                                                             (line  483)
* \B;in regular expressions:             Regular Expression Syntax.
                                                             (line  501)
* \b;in regular expressions <1>:         Regular Expression Syntax.
                                                             (line  597)
* \d;in regular expressions:             Regular Expression Syntax.
                                                             (line  514)
* \D;in regular expressions:             Regular Expression Syntax.
                                                             (line  529)
* \f;escape sequence:                    Formal grammar.     (line   28)
* \f;in regular expressions:             Regular Expression Syntax.
                                                             (line  597)
* \g;in regular expressions:             Functions.          (line  213)
* \n;escape sequence:                    Formal grammar.     (line   28)
* \N;escape sequence:                    Formal grammar.     (line   28)
* \N;escape sequence <1>:                Error Handlers.     (line   54)
* \n;in regular expressions:             Regular Expression Syntax.
                                                             (line  597)
* \N;in regular expressions:             Regular Expression Syntax.
                                                             (line  597)
* \r;escape sequence:                    Formal grammar.     (line   28)
* \r;in regular expressions:             Regular Expression Syntax.
                                                             (line  597)
* \s;in regular expressions:             Regular Expression Syntax.
                                                             (line  536)
* \S;in regular expressions:             Regular Expression Syntax.
                                                             (line  552)
* \t;escape sequence:                    Formal grammar.     (line   28)
* \t;in regular expressions:             Regular Expression Syntax.
                                                             (line  597)
* \u;escape sequence:                    Formal grammar.     (line   28)
* \U;escape sequence:                    Formal grammar.     (line   27)
* \u;escape sequence <1>:                Error Handlers.     (line   15)
* \U;escape sequence <1>:                Error Handlers.     (line   15)
* \u;in regular expressions:             Regular Expression Syntax.
                                                             (line  597)
* \U;in regular expressions:             Regular Expression Syntax.
                                                             (line  597)
* \v;escape sequence:                    Formal grammar.     (line   28)
* \v;in regular expressions:             Regular Expression Syntax.
                                                             (line  597)
* \w;in regular expressions:             Regular Expression Syntax.
                                                             (line  559)
* \W;in regular expressions:             Regular Expression Syntax.
                                                             (line  576)
* \x;escape sequence:                    Formal grammar.     (line   28)
* \x;escape sequence <1>:                Error Handlers.     (line   15)
* \x;in regular expressions:             Regular Expression Syntax.
                                                             (line  597)
* \z;in regular expressions:             Regular Expression Syntax.
                                                             (line  587)
* \Z;in regular expressions:             Regular Expression Syntax.
                                                             (line  587)
* &=;augmented assignment:               Augmented assignment statements.
                                                             (line    6)
* # (cancelletto);nella formattazione stile printf: Formattazione delle stringhe in stile printf.
                                                             (line   71)
* # (cancelletto);nella formattazione stile printf <1>: Formattazione Bytes stile printf.
                                                             (line   65)
* # (hash);comment:                      Comments.           (line    6)
* # (hash);comment <1>:                  site — Site-specific configuration hook.
                                                             (line   57)
* # (hash);commento:                     Un’introduzione informale a Python.
                                                             (line   14)
* # (hash);in doctests:                  Option Flags.       (line  165)
* # (hash);in regular expressions:       Flags.              (line  130)
* # (hash);in string formatting:         Format Specification Mini-Language.
                                                             (line  100)
* # (hash);source encoding declaration:  Encoding declarations.
                                                             (line    6)
* % (percent);datetime format:           timezone Objects.   (line   71)
* % (percent);datetime format <1>:       Functions<4>.       (line  320)
* % (percent);datetime format <2>:       Functions<4>.       (line  479)
* % (percent);environment variables expansion (Windows): os path — Common pathname manipulations.
                                                             (line  160)
* % (percent);environment variables expansion (Windows) <1>: Functions<13>.
                                                             (line  228)
* % (percent);interpolation in configuration files: Interpolation of values.
                                                             (line   10)
* % (percento);formattazione stile printf: Formattazione delle stringhe in stile printf.
                                                             (line    6)
* % (percento);formattazione stile printf <1>: Formattazione Bytes stile printf.
                                                             (line    6)
* %=;augmented assignment:               Augmented assignment statements.
                                                             (line    6)
* ^ (caret);in curses module:            curses ascii — Utilities for ASCII characters.
                                                             (line  229)
* ^ (caret);in regular expressions:      Regular Expression Syntax.
                                                             (line   53)
* ^ (caret);in regular expressions <1>:  Regular Expression Syntax.
                                                             (line  200)
* ^ (caret);in string formatting:        Format Specification Mini-Language.
                                                             (line   47)
* ^ (caret);marker:                      What About Exceptions?.
                                                             (line   93)
* ^ (caret);marker <1>:                  Module-Level Functions<2>.
                                                             (line   36)
* ^=;augmented assignment:               Augmented assignment statements.
                                                             (line    6)
* + (più);nella formattazione stile printf: Formattazione delle stringhe in stile printf.
                                                             (line   71)
* + (più);nella formattazione stile printf <1>: Formattazione Bytes stile printf.
                                                             (line   65)
* + (più);operatore binario:             Tipi Numerici — int float complex.
                                                             (line   30)
* + (più);operatore unario:              Tipi Numerici — int float complex.
                                                             (line   30)
* + (plus);binary operator:              Binary arithmetic operations.
                                                             (line   77)
* + (plus);in argparse module:           nargs.              (line   67)
* + (plus);in doctests:                  Option Flags.       (line  165)
* + (plus);in regular expressions:       Regular Expression Syntax.
                                                             (line   75)
* + (plus);in string formatting:         Format Specification Mini-Language.
                                                             (line   77)
* + (plus);unary operator:               Unary arithmetic and bitwise operations.
                                                             (line   14)
* +?;in regular expressions:             Regular Expression Syntax.
                                                             (line   86)
* ++;in regular expressions:             Regular Expression Syntax.
                                                             (line   96)
* +=;augmented assignment:               Augmented assignment statements.
                                                             (line    6)
* < (less);in string formatting:         Format Specification Mini-Language.
                                                             (line   47)
* < (less);in struct format strings:     Byte Order Size and Alignment.
                                                             (line   13)
* <<=;augmented assignment:              Augmented assignment statements.
                                                             (line    6)
* <BLANKLINE>:                           Option Flags.       (line   28)
* = (equals);assignment statement:       Assignment statements.
                                                             (line    6)
* = (equals);class definition:           Metaclasses.        (line    6)
* = (equals);for help in debugging using string literals: Raw string literals.
                                                             (line   25)
* = (equals);for help in debugging using string literals <1>: Metodi per le Stringhe.
                                                             (line  911)
* = (equals);function definition:        Function definitions.
                                                             (line   69)
* = (equals);in function calls:          Slicings.           (line   38)
* = (equals);in string formatting:       Format Specification Mini-Language.
                                                             (line   47)
* = (equals);in struct format strings:   Byte Order Size and Alignment.
                                                             (line   13)
* > (greater);in string formatting:      Format Specification Mini-Language.
                                                             (line   47)
* > (greater);in struct format strings:  Byte Order Size and Alignment.
                                                             (line   13)
* >>=;augmented assignment:              Augmented assignment statements.
                                                             (line    6)
* >>>:                                   Glossary.           (line    6)
* >>>;interpreter prompt:                How are Docstring Examples Recognized?.
                                                             (line   26)
* >>>;interpreter prompt <1>:            sys — System-specific parameters and functions.
                                                             (line 1624)
* | (vertical bar);in regular expressions: Regular Expression Syntax.
                                                             (line  226)
* |=;augmented assignment:               Augmented assignment statements.
                                                             (line    6)
* ~ (tilde);home directory expansion:    os path — Common pathname manipulations.
                                                             (line  136)
* $ (dollar);environment variables expansion: os path — Common pathname manipulations.
                                                             (line  160)
* $ (dollar);in regular expressions:     Regular Expression Syntax.
                                                             (line   58)
* $ (dollar);in template strings:        Template strings $-strings.
                                                             (line   23)
* $ (dollar);interpolation in configuration files: Interpolation of values.
                                                             (line   41)
* 0b;integer literal:                    Numeric literals.   (line   20)
* 0o;integer literal:                    Numeric literals.   (line   20)
* 0x;integer literal:                    Numeric literals.   (line   20)
* 2-digit years:                         time — Time access and conversions.
                                                             (line   34)
* A (nel modulo re):                     Flags.              (line   16)
* A_ALTCHARSET (nel modulo curses):      Constants<6>.       (line   65)
* A_ATTRIBUTES (nel modulo curses):      Constants<6>.       (line  126)
* A_BLINK (nel modulo curses):           Constants<6>.       (line   68)
* A_BOLD (nel modulo curses):            Constants<6>.       (line   71)
* A_CHARTEXT (nel modulo curses):        Constants<6>.       (line  129)
* A_COLOR (nel modulo curses):           Constants<6>.       (line  132)
* A_DIM (nel modulo curses):             Constants<6>.       (line   74)
* A_HORIZONTAL (nel modulo curses):      Constants<6>.       (line   99)
* A_INVIS (nel modulo curses):           Constants<6>.       (line   77)
* A_ITALIC (nel modulo curses):          Constants<6>.       (line   80)
* A_LEFT (nel modulo curses):            Constants<6>.       (line  102)
* A_LOW (nel modulo curses):             Constants<6>.       (line  105)
* A_NORMAL (nel modulo curses):          Constants<6>.       (line   83)
* A_PROTECT (nel modulo curses):         Constants<6>.       (line   86)
* A_REVERSE (nel modulo curses):         Constants<6>.       (line   89)
* A_RIGHT (nel modulo curses):           Constants<6>.       (line  108)
* A_STANDOUT (nel modulo curses):        Constants<6>.       (line   93)
* A_TOP (nel modulo curses):             Constants<6>.       (line  111)
* A_UNDERLINE (nel modulo curses):       Constants<6>.       (line   96)
* A_VERTICAL (nel modulo curses):        Constants<6>.       (line  114)
* a2b_base64() (nel modulo binascii):    binascii — Convert between binary and ASCII.
                                                             (line   40)
* a2b_hex() (nel modulo binascii):       binascii — Convert between binary and ASCII.
                                                             (line  144)
* a2b_qp() (nel modulo binascii):        binascii — Convert between binary and ASCII.
                                                             (line   70)
* a2b_uu() (nel modulo binascii):        binascii — Convert between binary and ASCII.
                                                             (line   25)
* a85decode() (nel modulo base64):       Base85 Encodings.   (line   52)
* a85encode() (nel modulo base64):       Base85 Encodings.   (line   28)
* ABC (classe in abc):                   abc — Abstract Base Classes.
                                                             (line   27)
* ABCMeta (classe in abc):               abc — Abstract Base Classes.
                                                             (line   52)
* ABDAY_1 (nel modulo locale):           locale — Internationalization services.
                                                             (line  240)
* ABDAY_2 (nel modulo locale):           locale — Internationalization services.
                                                             (line  240)
* ABDAY_3 (nel modulo locale):           locale — Internationalization services.
                                                             (line  240)
* ABDAY_4 (nel modulo locale):           locale — Internationalization services.
                                                             (line  240)
* ABDAY_5 (nel modulo locale):           locale — Internationalization services.
                                                             (line  240)
* ABDAY_6 (nel modulo locale):           locale — Internationalization services.
                                                             (line  240)
* ABDAY_7 (nel modulo locale):           locale — Internationalization services.
                                                             (line  240)
* abiflags (nel modulo sys):             sys — System-specific parameters and functions.
                                                             (line   13)
* ABMON_1 (nel modulo locale):           locale — Internationalization services.
                                                             (line  265)
* ABMON_10 (nel modulo locale):          locale — Internationalization services.
                                                             (line  265)
* ABMON_11 (nel modulo locale):          locale — Internationalization services.
                                                             (line  265)
* ABMON_12 (nel modulo locale):          locale — Internationalization services.
                                                             (line  265)
* ABMON_2 (nel modulo locale):           locale — Internationalization services.
                                                             (line  265)
* ABMON_3 (nel modulo locale):           locale — Internationalization services.
                                                             (line  265)
* ABMON_4 (nel modulo locale):           locale — Internationalization services.
                                                             (line  265)
* ABMON_5 (nel modulo locale):           locale — Internationalization services.
                                                             (line  265)
* ABMON_6 (nel modulo locale):           locale — Internationalization services.
                                                             (line  265)
* ABMON_7 (nel modulo locale):           locale — Internationalization services.
                                                             (line  265)
* ABMON_8 (nel modulo locale):           locale — Internationalization services.
                                                             (line  265)
* ABMON_9 (nel modulo locale):           locale — Internationalization services.
                                                             (line  265)
* abort (C function):                    Process Control.    (line    7)
* ABORT (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  147)
* abort_clients() (asyncio.Server metodo): Server Objects.   (line   56)
* abort() (asyncio.Barrier metodo):      Barrier.            (line   87)
* abort() (asyncio.DatagramTransport metodo): Datagram Transports.
                                                             (line   20)
* abort() (asyncio.WriteTransport metodo): Write-only Transports.
                                                             (line    6)
* abort() (ftplib.FTP metodo):           FTP objects.        (line  153)
* abort() (nel modulo os):               Process Management. (line   16)
* abort() (threading.Barrier metodo):    Barrier objects.    (line   82)
* ABORTRETRYIGNORE (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  162)
* ABOVE_NORMAL_PRIORITY_CLASS (nel modulo subprocess): Windows Constants.
                                                             (line   68)
* above() (curses.panel.Panel metodo):   Panel Objects.      (line   13)
* abs() (decimal.Context metodo):        Context objects.    (line  270)
* abs() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line   85)
* absolute_import (nel modulo __future__): Module Contents<5>.
                                                             (line   26)
* absolute() (pathlib.Path metodo):      Expanding and resolving paths.
                                                             (line   38)
* AbsoluteLinkError:                     tarfile — Read and write tar archive files.
                                                             (line  299)
* AbsolutePathError:                     tarfile — Read and write tar archive files.
                                                             (line  285)
* abspath() (nel modulo os.path):        os path — Common pathname manipulations.
                                                             (line   49)
* abstract base class:                   Glossary.           (line   23)
* AbstractAsyncContextManager (classe in contextlib): Utilities.
                                                             (line   19)
* AbstractBasicAuthHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  383)
* abstractclassmethod() (nel modulo abc): abc — Abstract Base Classes.
                                                             (line  238)
* AbstractContextManager (classe in contextlib): Utilities.  (line    8)
* AbstractDigestAuthHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  422)
* AbstractEventLoop (classe in asyncio): Event Loop Implementations.
                                                             (line   53)
* AbstractEventLoopPolicy (classe in asyncio): Policy Objects.
                                                             (line    8)
* abstractmethod() (nel modulo abc):     abc — Abstract Base Classes.
                                                             (line  161)
* abstractproperty() (nel modulo abc):   abc — Abstract Base Classes.
                                                             (line  282)
* AbstractSet (classe in typing):        Aliases to container ABCs in collections abc.
                                                             (line    6)
* abstractstaticmethod() (nel modulo abc): abc — Abstract Base Classes.
                                                             (line  260)
* accept() (multiprocessing.connection.Listener metodo): Listeners and Clients.
                                                             (line   84)
* accept() (socket.socket metodo):       Socket Objects.     (line   13)
* access() (nel modulo os):              Files and Directories.
                                                             (line   51)
* accumulate() (nel modulo itertools):   Itertool Functions. (line   10)
* ACK (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   37)
* aclose() (agen metodo):                Asynchronous generator-iterator methods.
                                                             (line   61)
* aclose() (contextlib.AsyncExitStack metodo): Utilities.    (line  650)
* aclosing() (nel modulo contextlib):    Utilities.          (line  187)
* acos() (nel modulo cmath):             Trigonometric functions<2>.
                                                             (line    6)
* acos() (nel modulo math):              Trigonometric functions.
                                                             (line    6)
* acosh() (nel modulo cmath):            Hyperbolic functions<2>.
                                                             (line    6)
* acosh() (nel modulo math):             Hyperbolic functions.
                                                             (line    9)
* acquire() (_thread.lock metodo):       _thread — Low-level threading API.
                                                             (line  145)
* acquire() (asyncio.Condition metodo):  Condition.          (line   47)
* acquire() (asyncio.Lock metodo):       Lock.               (line   35)
* acquire() (asyncio.Semaphore metodo):  Semaphore.          (line   42)
* acquire() (logging.Handler metodo):    Handler Objects.    (line   26)
* acquire() (multiprocessing.Lock metodo): Synchronization primitives.
                                                             (line   86)
* acquire() (multiprocessing.RLock metodo): Synchronization primitives.
                                                             (line  150)
* acquire() (threading.Condition metodo): Condition objects. (line   86)
* acquire() (threading.Lock metodo):     Lock objects.       (line   43)
* acquire() (threading.RLock metodo):    RLock objects.      (line   44)
* acquire() (threading.Semaphore metodo): Semaphore objects. (line   35)
* ACS_BBSS (nel modulo curses):          Constants<6>.       (line  470)
* ACS_BLOCK (nel modulo curses):         Constants<6>.       (line  473)
* ACS_BOARD (nel modulo curses):         Constants<6>.       (line  476)
* ACS_BSBS (nel modulo curses):          Constants<6>.       (line  479)
* ACS_BSSB (nel modulo curses):          Constants<6>.       (line  482)
* ACS_BSSS (nel modulo curses):          Constants<6>.       (line  485)
* ACS_BTEE (nel modulo curses):          Constants<6>.       (line  488)
* ACS_BULLET (nel modulo curses):        Constants<6>.       (line  491)
* ACS_CKBOARD (nel modulo curses):       Constants<6>.       (line  494)
* ACS_DARROW (nel modulo curses):        Constants<6>.       (line  497)
* ACS_DEGREE (nel modulo curses):        Constants<6>.       (line  500)
* ACS_DIAMOND (nel modulo curses):       Constants<6>.       (line  503)
* ACS_GEQUAL (nel modulo curses):        Constants<6>.       (line  506)
* ACS_HLINE (nel modulo curses):         Constants<6>.       (line  509)
* ACS_LANTERN (nel modulo curses):       Constants<6>.       (line  512)
* ACS_LARROW (nel modulo curses):        Constants<6>.       (line  515)
* ACS_LEQUAL (nel modulo curses):        Constants<6>.       (line  518)
* ACS_LLCORNER (nel modulo curses):      Constants<6>.       (line  521)
* ACS_LRCORNER (nel modulo curses):      Constants<6>.       (line  524)
* ACS_LTEE (nel modulo curses):          Constants<6>.       (line  527)
* ACS_NEQUAL (nel modulo curses):        Constants<6>.       (line  530)
* ACS_PI (nel modulo curses):            Constants<6>.       (line  533)
* ACS_PLMINUS (nel modulo curses):       Constants<6>.       (line  536)
* ACS_PLUS (nel modulo curses):          Constants<6>.       (line  539)
* ACS_RARROW (nel modulo curses):        Constants<6>.       (line  542)
* ACS_RTEE (nel modulo curses):          Constants<6>.       (line  545)
* ACS_S1 (nel modulo curses):            Constants<6>.       (line  548)
* ACS_S3 (nel modulo curses):            Constants<6>.       (line  551)
* ACS_S7 (nel modulo curses):            Constants<6>.       (line  554)
* ACS_S9 (nel modulo curses):            Constants<6>.       (line  557)
* ACS_SBBS (nel modulo curses):          Constants<6>.       (line  560)
* ACS_SBSB (nel modulo curses):          Constants<6>.       (line  563)
* ACS_SBSS (nel modulo curses):          Constants<6>.       (line  566)
* ACS_SSBB (nel modulo curses):          Constants<6>.       (line  569)
* ACS_SSBS (nel modulo curses):          Constants<6>.       (line  572)
* ACS_SSSB (nel modulo curses):          Constants<6>.       (line  575)
* ACS_SSSS (nel modulo curses):          Constants<6>.       (line  578)
* ACS_STERLING (nel modulo curses):      Constants<6>.       (line  581)
* ACS_TTEE (nel modulo curses):          Constants<6>.       (line  584)
* ACS_UARROW (nel modulo curses):        Constants<6>.       (line  587)
* ACS_ULCORNER (nel modulo curses):      Constants<6>.       (line  590)
* ACS_URCORNER (nel modulo curses):      Constants<6>.       (line  593)
* ACS_VLINE (nel modulo curses):         Constants<6>.       (line  596)
* Action (classe in argparse):           Action classes.     (line   11)
* action (optparse.Option attributo):    Option attributes.  (line   19)
* ACTIONS (optparse.Option attributo):   Adding new actions. (line   31)
* activate_stack_trampoline() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line 1888)
* active_children() (nel modulo multiprocessing): Miscellaneous<4>.
                                                             (line    6)
* active_count() (nel modulo threading): Reference<2>.       (line    8)
* actual() (tkinter.font.Font metodo):   tkinter font — Tkinter font wrapper.
                                                             (line   47)
* Add (classe in ast):                   Expressions<2>.     (line   53)
* add_alias() (nel modulo email.charset): email charset Representing character sets.
                                                             (line  193)
* add_alternative() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  640)
* add_argument_group() (argparse.ArgumentParser metodo): Argument groups.
                                                             (line    6)
* add_argument() (argparse.ArgumentParser metodo): The add_argument method.
                                                             (line    6)
* add_attachment() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  652)
* add_cgi_vars() (wsgiref.handlers.BaseHandler metodo): wsgiref handlers – server/gateway base classes.
                                                             (line  135)
* add_charset() (nel modulo email.charset): email charset Representing character sets.
                                                             (line  164)
* add_codec() (nel modulo email.charset): email charset Representing character sets.
                                                             (line  202)
* add_cookie_header() (http.cookiejar.CookieJar metodo): CookieJar and FileCookieJar Objects.
                                                             (line   11)
* add_dll_directory() (nel modulo os):   Process Management. (line   24)
* add_done_callback() (asyncio.Future metodo): Future Object.
                                                             (line   81)
* add_done_callback() (asyncio.Task metodo): Task Object.    (line  101)
* add_done_callback() (concurrent.futures.Future metodo): Future Objects.
                                                             (line   66)
* add_fallback() (gettext.NullTranslations metodo): The NullTranslations class.
                                                             (line   28)
* add_flag() (mailbox.Maildir metodo):   Maildir objects.    (line  129)
* add_flag() (mailbox.MaildirMessage metodo): MaildirMessage objects.
                                                             (line   76)
* add_flag() (mailbox.mboxMessage metodo): mboxMessage objects.
                                                             (line   79)
* add_flag() (mailbox.MMDFMessage metodo): MMDFMessage objects.
                                                             (line   78)
* add_folder() (mailbox.Maildir metodo): Maildir objects.    (line   75)
* add_folder() (mailbox.MH metodo):      MH objects.         (line   45)
* add_get_handler() (email.contentmanager.ContentManager metodo): email contentmanager Managing MIME Content.
                                                             (line   75)
* add_handler() (urllib.request.OpenerDirector metodo): OpenerDirector Objects.
                                                             (line    8)
* add_header() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  260)
* add_header() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  371)
* add_header() (urllib.request.Request metodo): Request Objects.
                                                             (line   79)
* add_header() (wsgiref.headers.Headers metodo): wsgiref headers – WSGI response header tools.
                                                             (line   61)
* add_history() (nel modulo readline):   History list.       (line   38)
* add_label() (mailbox.BabylMessage metodo): BabylMessage objects.
                                                             (line   55)
* add_mutually_exclusive_group() (argparse.ArgumentParser metodo): Mutual exclusion.
                                                             (line    6)
* add_note() (BaseException metodo):     Base classes.       (line   50)
* add_option() (optparse.OptionParser metodo): Defining options.
                                                             (line   14)
* add_parent() (urllib.request.BaseHandler metodo): BaseHandler Objects.
                                                             (line   10)
* add_password() (urllib.request.HTTPPasswordMgr metodo): HTTPPasswordMgr Objects.
                                                             (line    9)
* add_password() (urllib.request.HTTPPasswordMgrWithPriorAuth metodo): HTTPPasswordMgrWithPriorAuth Objects.
                                                             (line   10)
* add_reader() (asyncio.loop metodo):    Watching file descriptors.
                                                             (line    6)
* add_related() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  627)
* add_section() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  122)
* add_section() (configparser.RawConfigParser metodo): RawConfigParser Objects.
                                                             (line   37)
* add_sequence() (mailbox.MHMessage metodo): MHMessage objects.
                                                             (line   41)
* add_set_handler() (email.contentmanager.ContentManager metodo): email contentmanager Managing MIME Content.
                                                             (line   80)
* add_signal_handler() (asyncio.loop metodo): Unix signals.  (line    6)
* add_subparsers() (argparse.ArgumentParser metodo): Subcommands.
                                                             (line    6)
* add_type() (mimetypes.MimeTypes metodo): MimeTypes objects.
                                                             (line  104)
* add_type() (nel modulo mimetypes):     mimetypes — Map filenames to MIME types.
                                                             (line  124)
* add_unredirected_header() (urllib.request.Request metodo): Request Objects.
                                                             (line   91)
* add_writer() (asyncio.loop metodo):    Watching file descriptors.
                                                             (line   20)
* add() (decimal.Context metodo):        Context objects.    (line  274)
* add() (graphlib.TopologicalSorter metodo): graphlib — Functionality to operate with graph-like structures.
                                                             (line   81)
* add() (mailbox.Mailbox metodo):        Mailbox objects.    (line   59)
* add() (mailbox.Maildir metodo):        Maildir objects.    (line  193)
* add() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line   90)
* add() (pstats.Stats metodo):           The Stats Class.    (line   49)
* add() (set metodo):                    Tipi di Insiemi — set frozenset.
                                                             (line  207)
* add() (tarfile.TarFile metodo):        TarFile Objects.    (line  273)
* add() (tkinter.ttk.Notebook metodo):   ttk Notebook.       (line    8)
* addAsyncCleanup() (unittest.IsolatedAsyncioTestCase metodo): Test cases.
                                                             (line  956)
* addaudithook() (nel modulo sys):       sys — System-specific parameters and functions.
                                                             (line   26)
* addch() (curses.window metodo):        Window Objects.     (line   11)
* addClassCleanup() (unittest.TestCase metodo della classe): Test cases.
                                                             (line  875)
* addCleanup() (unittest.TestCase metodo): Test cases.       (line  835)
* addcomponent() (turtle.Shape metodo):  Public classes.     (line   66)
* addDuration() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  440)
* addError() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  370)
* addExpectedFailure() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  406)
* addFailure() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  381)
* addfile() (tarfile.TarFile metodo):    TarFile Objects.    (line  292)
* addFilter() (logging.Handler metodo):  Handler Objects.    (line   53)
* addFilter() (logging.Logger metodo):   Logger Objects.     (line  327)
* addHandler() (logging.Logger metodo):  Logger Objects.     (line  344)
* addinfourl (classe in urllib.response): urllib response — Response classes used by urllib.
                                                             (line   12)
* addition:                              Binary arithmetic operations.
                                                             (line   77)
* addLevelName() (nel modulo logging):   Module-Level Functions.
                                                             (line  128)
* addModuleCleanup() (nel modulo unittest): setUpModule and tearDownModule.
                                                             (line   22)
* addnstr() (curses.window metodo):      Window Objects.     (line   25)
* AddPackagePath() (nel modulo modulefinder): modulefinder — Find modules used by a script.
                                                             (line   16)
* addr_spec (email.headerregistry.Address attributo): email headerregistry Custom Header Objects.
                                                             (line  441)
* Address (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  403)
* address (email.headerregistry.SingleAddressHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  222)
* address (multiprocessing.connection.Listener attributo): Listeners and Clients.
                                                             (line   99)
* address (multiprocessing.managers.BaseManager attributo): Managers.
                                                             (line  139)
* address_exclude() (ipaddress.IPv4Network metodo): Network objects.
                                                             (line  160)
* address_exclude() (ipaddress.IPv6Network metodo): Network objects.
                                                             (line  343)
* address_family (socketserver.BaseServer attributo): Server Objects<2>.
                                                             (line   66)
* address_string() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  380)
* addresses (email.headerregistry.AddressHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  195)
* addresses (email.headerregistry.Group attributo): email headerregistry Custom Header Objects.
                                                             (line  477)
* AddressHeader (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  180)
* addressof() (nel modulo ctypes):       Utility functions.  (line    6)
* AddressValueError:                     Custom Exceptions.  (line    9)
* addshape() (nel modulo turtle):        Settings and special methods.
                                                             (line   71)
* addsitedir() (nel modulo site):        Module contents<5>. (line   52)
* addSkip() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  398)
* addstr() (curses.window metodo):       Window Objects.     (line   33)
* addSubTest() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  424)
* addSuccess() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  392)
* addTest() (unittest.TestSuite metodo): Grouping tests.     (line   25)
* addTests() (unittest.TestSuite metodo): Grouping tests.    (line   30)
* addTypeEqualityFunc() (unittest.TestCase metodo): Test cases.
                                                             (line  652)
* addUnexpectedSuccess() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  416)
* adjust_int_max_str_digits() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  774)
* adjusted() (decimal.Decimal metodo):   Decimal objects.    (line  116)
* adler32() (nel modulo zlib):           zlib — Compression compatible with gzip.
                                                             (line   29)
* AF_ALG (nel modulo socket):            Constants<8>.       (line  272)
* AF_BLUETOOTH (nel modulo socket):      Constants<8>.       (line  307)
* AF_CAN (nel modulo socket):            Constants<8>.       (line  135)
* AF_DIVERT (nel modulo socket):         Constants<8>.       (line  211)
* AF_HYPERV (nel modulo socket):         Constants<8>.       (line  445)
* AF_INET (nel modulo socket):           Constants<8>.       (line   11)
* AF_INET6 (nel modulo socket):          Constants<8>.       (line   11)
* AF_LINK (nel modulo socket):           Constants<8>.       (line  296)
* AF_PACKET (nel modulo socket):         Constants<8>.       (line  221)
* AF_QIPCRTR (nel modulo socket):        Constants<8>.       (line  406)
* AF_RDS (nel modulo socket):            Constants<8>.       (line  243)
* AF_UNIX (nel modulo socket):           Constants<8>.       (line   11)
* AF_UNSPEC (nel modulo socket):         Constants<8>.       (line   21)
* AF_VSOCK (nel modulo socket):          Constants<8>.       (line  283)
* alarm() (nel modulo signal):           Module contents<2>. (line  297)
* ALERT_DESCRIPTION_HANDSHAKE_FAILURE (nel modulo ssl): Constants<9>.
                                                             (line  516)
* ALERT_DESCRIPTION_INTERNAL_ERROR (nel modulo ssl): Constants<9>.
                                                             (line  516)
* AlertDescription (classe in ssl):      Constants<9>.       (line  530)
* algorithm (sys.hash_info attributo):   sys — System-specific parameters and functions.
                                                             (line 1091)
* algorithms_available (nel modulo hashlib): Attributes.     (line   17)
* algorithms_guaranteed (nel modulo hashlib): Attributes.    (line    8)
* alias (classe in ast):                 Imports.            (line   38)
* alias (pdb command):                   Debugger commands.  (line  385)
* alignment() (nel modulo ctypes):       Utility functions.  (line   14)
* alive (weakref.finalize attributo):    weakref — Weak references.
                                                             (line  312)
* ALL_COMPLETED (nel modulo asyncio):    Waiting Primitives. (line   45)
* ALL_COMPLETED (nel modulo concurrent.futures): Module Functions.
                                                             (line   40)
* all_errors (nel modulo ftplib):        Module variables.   (line   27)
* all_features (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line  100)
* all_frames (tracemalloc.Filter attributo): Filter.         (line   59)
* all_properties (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line  132)
* all_suffixes() (nel modulo importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line   57)
* all_tasks() (nel modulo asyncio):      Introspection.      (line   16)
* allocate_lock() (nel modulo _thread):  _thread — Low-level threading API.
                                                             (line   83)
* allocfunc (C type):                    Slot Type typedefs. (line    6)
* ALLOW_MISSING (nel modulo os.path):    os path — Common pathname manipulations.
                                                             (line  426)
* allow_reuse_address (socketserver.BaseServer attributo): Server Objects<2>.
                                                             (line   96)
* allowed_domains() (http.cookiejar.DefaultCookiePolicy metodo): DefaultCookiePolicy Objects.
                                                             (line   65)
* ALT_DIGITS (nel modulo locale):        locale — Internationalization services.
                                                             (line  345)
* alt() (nel modulo curses.ascii):       curses ascii — Utilities for ASCII characters.
                                                             (line  221)
* altsep (nel modulo os):                Miscellaneous System Information.
                                                             (line  125)
* altzone (nel modulo time):             Timezone Constants. (line    6)
* ALWAYS_EQ (nel modulo test.support):   test support — Utilities for the Python test suite.
                                                             (line  192)
* ALWAYS_TYPED_ACTIONS (optparse.Option attributo): Adding new actions.
                                                             (line   43)
* AmbiguousOptionError:                  Exceptions<11>.     (line   25)
* AMPER (nel modulo token):              token — Constants used with Python parse trees.
                                                             (line  248)
* AMPEREQUAL (nel modulo token):         token — Constants used with Python parse trees.
                                                             (line  314)
* Anchor (classe in importlib.resources): importlib resources – Package resource reading opening and access.
                                                             (line   46)
* anchor (pathlib.PurePath attributo):   Methods and properties.
                                                             (line   65)
* And (classe in ast):                   Expressions<2>.     (line   86)
* and_() (nel modulo operator):          operator — Standard operators as functions.
                                                             (line   95)
* android_ver() (nel modulo platform):   Android platform.   (line    6)
* AnnAssign (classe in ast):             Statements.         (line   41)
* annotate function:                     Glossary.           (line   37)
* Annotated (nel modulo typing):         Special forms.      (line  297)
* annotated;assignment:                  Annotated assignment statements.
                                                             (line    6)
* annotation:                            Glossary.           (line   45)
* annotation (inspect.Parameter attributo): Introspecting callables with the Signature object.
                                                             (line  242)
* ANNOTATION (symtable.SymbolTableType attributo): Examining Symbol Tables.
                                                             (line   26)
* annotations (nel modulo __future__):   Module Contents<5>. (line   47)
* annotations_to_string() (nel modulo annotationlib): Functions<11>.
                                                             (line    6)
* annotazione;annotazione di tipo; suggerimento di tipo: Tipi di annotazione di tipo — Alias generico Union.
                                                             (line    6)
* anonymous;function:                    Lambdas.            (line    6)
* answer_challenge() (nel modulo multiprocessing.connection): Listeners and Clients.
                                                             (line   25)
* anticipate_failure() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  473)
* Any (nel modulo typing):               Special types.      (line    9)
* ANY (nel modulo unittest.mock):        ANY.                (line    6)
* ANY_CONTIGUOUS (inspect.BufferFlags attributo): Buffer flags.
                                                             (line   29)
* AnyStr (nel modulo typing):            Special types.      (line   21)
* api_version (nel modulo sys):          sys — System-specific parameters and functions.
                                                             (line 2197)
* apilevel (nel modulo sqlite3):         Module constants.   (line   65)
* apop() (poplib.POP3 metodo):           POP3 Objects.       (line   42)
* append_history_file() (nel modulo readline): History file. (line   27)
* append() (array.array metodo):         array — Efficient arrays of numeric values.
                                                             (line  122)
* append() (collections.deque metodo):   deque objects.      (line   35)
* append() (email.header.Header metodo): email header Internationalized headers.
                                                             (line   96)
* append() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line   33)
* append() (sequence metodo):            Tipi di Sequenza Mutabili.
                                                             (line   71)
* append() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line   87)
* appendChild() (xml.dom.Node metodo):   Node Objects.       (line  115)
* appendleft() (collections.deque metodo): deque objects.    (line   39)
* AppleFrameworkLoader (classe in importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line  444)
* application_uri() (nel modulo wsgiref.util): wsgiref util – WSGI environment utilities.
                                                             (line   34)
* apply_async() (multiprocessing.pool.Pool metodo): Process Pools.
                                                             (line   79)
* apply_defaults() (inspect.BoundArguments metodo): Introspecting callables with the Signature object.
                                                             (line  387)
* apply() (multiprocessing.pool.Pool metodo): Process Pools. (line   71)
* APRIL (nel modulo calendar):           calendar — General calendar-related functions.
                                                             (line  490)
* architecture() (nel modulo platform):  Cross platform.     (line    6)
* archive (zipimport.zipimporter attributo): zipimporter Objects.
                                                             (line   96)
* AREGTYPE (nel modulo tarfile):         tarfile — Read and write tar archive files.
                                                             (line  324)
* aRepr (nel modulo reprlib):            reprlib — Alternate repr implementation.
                                                             (line   44)
* arg (classe in ast):                   Function and class definitions.
                                                             (line   68)
* args (BaseException attributo):        Base classes.       (line   17)
* args (functools.partial attributo):    partial Objects.    (line   15)
* args (inspect.BoundArguments attributo): Introspecting callables with the Signature object.
                                                             (line  372)
* args (pdb command):                    Debugger commands.  (line  274)
* args (subprocess.CompletedProcess attributo): Using the subprocess Module.
                                                             (line  106)
* args (subprocess.Popen attributo):     Popen Objects.      (line  109)
* args (typing.ParamSpec attributo):     Building generic types and type aliases.
                                                             (line  456)
* args_from_interpreter_flags() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  340)
* argtypes (ctypes._CFuncPtr attributo): Foreign functions.  (line   46)
* argument:                              Glossary.           (line   60)
* argument;call semantics:               Slicings.           (line   39)
* argument;difference from parameter:    How can I pass optional or keyword parameters from one function to another?.
                                                             (line   17)
* argument;function definition:          Function definitions.
                                                             (line   69)
* ArgumentDefaultsHelpFormatter (classe in argparse): formatter_class.
                                                             (line   10)
* ArgumentError:                         Exceptions<9>.      (line    6)
* ArgumentError <1>:                     Exceptions<10>.     (line    6)
* ArgumentParser (classe in argparse):   ArgumentParser objects.
                                                             (line    6)
* arguments (classe in ast):             Function and class definitions.
                                                             (line   49)
* arguments (inspect.BoundArguments attributo): Introspecting callables with the Signature object.
                                                             (line  353)
* ArgumentTypeError:                     Exceptions<10>.     (line   14)
* argv (in module sys):                  Process-wide parameters.
                                                             (line  225)
* argv (in module sys) <1>:              PyConfig.           (line  130)
* argv (nel modulo sys):                 sys — System-specific parameters and functions.
                                                             (line   71)
* arithmetic;conversion:                 Arithmetic conversions.
                                                             (line    6)
* ArithmeticError:                       Base classes.       (line   72)
* aritmetica:                            Tipi Numerici — int float complex.
                                                             (line   30)
* array (classe in array):               array — Efficient arrays of numeric values.
                                                             (line   88)
* Array (classe in ctypes):              Arrays and pointers.
                                                             (line    6)
* Array() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  215)
* ARRAY() (nel modulo ctypes):           Arrays and pointers.
                                                             (line   31)
* Array() (nel modulo multiprocessing.sharedctypes): The multiprocessing sharedctypes module.
                                                             (line   51)
* Array() (nel modulo multiprocessing):  Shared ctypes Objects.
                                                             (line   42)
* arrays:                                array — Efficient arrays of numeric values.
                                                             (line    6)
* arraysize (sqlite3.Cursor attributo):  Cursor objects.     (line  174)
* AS pattern, OR pattern, capture pattern, wildcard pattern: Patterns.
                                                             (line    6)
* as_bytes() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  107)
* as_bytes() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  107)
* as_completed() (nel modulo asyncio):   Waiting Primitives. (line   60)
* as_completed() (nel modulo concurrent.futures): Module Functions.
                                                             (line   44)
* as_digested_dict (compression.zstd.ZstdDict attributo): Zstandard dictionaries.
                                                             (line  143)
* as_file() (nel modulo importlib.resources): importlib resources – Package resource reading opening and access.
                                                             (line   74)
* as_integer_ratio():                    fractions — Rational numbers.
                                                             (line   16)
* as_integer_ratio() (decimal.Decimal metodo): Decimal objects.
                                                             (line  124)
* as_integer_ratio() (float metodo):     Metodi aggiuntivi su Float.
                                                             (line   26)
* as_integer_ratio() (fractions.Fraction metodo): fractions — Rational numbers.
                                                             (line  126)
* as_integer_ratio() (int metodo):       Metodi Aggiuntivi sui Tipi Integer.
                                                             (line  165)
* as_posix() (pathlib.PurePath metodo):  Methods and properties.
                                                             (line  178)
* as_string() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line   61)
* as_string() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line   61)
* as_tuple() (decimal.Decimal metodo):   Decimal objects.    (line  138)
* as_undigested_dict (compression.zstd.ZstdDict attributo): Zstandard dictionaries.
                                                             (line  147)
* as_uri() (pathlib.Path metodo):        Parsing and generating URIs.
                                                             (line   47)
* as;except clause:                      except clause.      (line   31)
* as;import statement:                   The import statement.
                                                             (line   39)
* as;match statement:                    The match statement.
                                                             (line    6)
* as;with statement:                     The with statement. (line    6)
* ASCII:                                 Literals.           (line   15)
* ASCII (nel modulo re):                 Flags.              (line   16)
* ascii_letters (nel modulo string):     String constants.   (line    8)
* ascii_lowercase (nel modulo string):   String constants.   (line   14)
* ascii_uppercase (nel modulo string):   String constants.   (line   19)
* ascii() (nel modulo curses.ascii):     curses ascii — Utilities for ASCII characters.
                                                             (line  212)
* asctime() (nel modulo time):           Functions<4>.       (line    6)
* asdict() (nel modulo dataclasses):     Module contents<4>. (line  344)
* asend() (agen metodo):                 Asynchronous generator-iterator methods.
                                                             (line   28)
* asin() (nel modulo cmath):             Trigonometric functions<2>.
                                                             (line   12)
* asin() (nel modulo math):              Trigonometric functions.
                                                             (line   11)
* asinh() (nel modulo cmath):            Hyperbolic functions<2>.
                                                             (line   11)
* asinh() (nel modulo math):             Hyperbolic functions.
                                                             (line   13)
* askcolor() (nel modulo tkinter.colorchooser): tkinter colorchooser — Color choosing dialog.
                                                             (line   17)
* askdirectory() (nel modulo tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line   54)
* askfloat() (nel modulo tkinter.simpledialog): tkinter simpledialog — Standard Tkinter input dialogs.
                                                             (line   14)
* askinteger() (nel modulo tkinter.simpledialog): tkinter simpledialog — Standard Tkinter input dialogs.
                                                             (line   14)
* askokcancel() (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  119)
* askopenfile() (nel modulo tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line   31)
* askopenfilename() (nel modulo tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line   42)
* askopenfilenames() (nel modulo tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line   42)
* askopenfiles() (nel modulo tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line   31)
* askquestion() (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  113)
* askretrycancel() (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  126)
* asksaveasfile() (nel modulo tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line   37)
* asksaveasfilename() (nel modulo tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line   49)
* askstring() (nel modulo tkinter.simpledialog): tkinter simpledialog — Standard Tkinter input dialogs.
                                                             (line   14)
* askyesno() (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  133)
* askyesnocancel() (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  139)
* Assert (classe in ast):                Statements.         (line  127)
* assert_any_await() (unittest.mock.AsyncMock metodo): The Mock Class.
                                                             (line  845)
* assert_any_call() (unittest.mock.Mock metodo): The Mock Class.
                                                             (line  150)
* assert_awaited_once_with() (unittest.mock.AsyncMock metodo): The Mock Class.
                                                             (line  828)
* assert_awaited_once() (unittest.mock.AsyncMock metodo): The Mock Class.
                                                             (line  795)
* assert_awaited_with() (unittest.mock.AsyncMock metodo): The Mock Class.
                                                             (line  811)
* assert_awaited() (unittest.mock.AsyncMock metodo): The Mock Class.
                                                             (line  775)
* assert_called_once_with() (unittest.mock.Mock metodo): The Mock Class.
                                                             (line  135)
* assert_called_once() (unittest.mock.Mock metodo): The Mock Class.
                                                             (line  107)
* assert_called_with() (unittest.mock.Mock metodo): The Mock Class.
                                                             (line  125)
* assert_called() (unittest.mock.Mock metodo): The Mock Class.
                                                             (line   96)
* assert_has_awaits() (unittest.mock.AsyncMock metodo): The Mock Class.
                                                             (line  862)
* assert_has_calls() (unittest.mock.Mock metodo): The Mock Class.
                                                             (line  166)
* assert_never() (nel modulo typing):    Functions and decorators.
                                                             (line   44)
* assert_not_awaited() (unittest.mock.AsyncMock metodo): The Mock Class.
                                                             (line  889)
* assert_not_called() (unittest.mock.Mock metodo): The Mock Class.
                                                             (line  187)
* assert_python_failure() (nel modulo test.support.script_helper): test support script_helper — Utilities for the Python execution tests.
                                                             (line   57)
* assert_python_ok() (nel modulo test.support.script_helper): test support script_helper — Utilities for the Python execution tests.
                                                             (line   40)
* assert_type() (nel modulo typing):     Functions and decorators.
                                                             (line   15)
* assertAlmostEqual() (unittest.TestCase metodo): Test cases.
                                                             (line  545)
* assertCountEqual() (unittest.TestCase metodo): Test cases. (line  602)
* assertDictEqual() (unittest.TestCase metodo): Test cases.  (line  740)
* assertEndsWith() (unittest.TestCase metodo): Test cases.   (line  627)
* assertEqual() (unittest.TestCase metodo): Test cases.      (line  183)
* assertFalse() (unittest.TestCase metodo): Test cases.      (line  208)
* assertGreater() (unittest.TestCase metodo): Test cases.    (line  570)
* assertGreaterEqual() (unittest.TestCase metodo): Test cases.
                                                             (line  570)
* assertHasAttr() (unittest.TestCase metodo): Test cases.    (line  637)
* assertIn() (unittest.TestCase metodo): Test cases.         (line  235)
* assertInBytecode() (test.support.bytecode_helper.BytecodeTestCase metodo): test support bytecode_helper — Support tools for testing correct bytecode generation.
                                                             (line   22)
* AssertionError:                        Concrete exceptions.
                                                             (line    8)
* assertIs() (unittest.TestCase metodo): Test cases.         (line  220)
* assertIsInstance() (unittest.TestCase metodo): Test cases. (line  242)
* assertIsNone() (unittest.TestCase metodo): Test cases.     (line  228)
* assertIsNot() (unittest.TestCase metodo): Test cases.      (line  220)
* assertIsNotNone() (unittest.TestCase metodo): Test cases.  (line  228)
* assertIsSubclass() (unittest.TestCase metodo): Test cases. (line  252)
* assertLess() (unittest.TestCase metodo): Test cases.       (line  570)
* assertLessEqual() (unittest.TestCase metodo): Test cases.  (line  570)
* assertListEqual() (unittest.TestCase metodo): Test cases.  (line  717)
* assertLogs() (unittest.TestCase metodo): Test cases.       (line  427)
* assertMultiLineEqual() (unittest.TestCase metodo): Test cases.
                                                             (line  692)
* assertNoLogs() (unittest.TestCase metodo): Test cases.     (line  471)
* assertNotAlmostEqual() (unittest.TestCase metodo): Test cases.
                                                             (line  545)
* assertNotEndsWith() (unittest.TestCase metodo): Test cases.
                                                             (line  629)
* assertNotEqual() (unittest.TestCase metodo): Test cases.   (line  203)
* assertNotHasAttr() (unittest.TestCase metodo): Test cases. (line  639)
* assertNotIn() (unittest.TestCase metodo): Test cases.      (line  235)
* assertNotInBytecode() (test.support.bytecode_helper.BytecodeTestCase metodo): test support bytecode_helper — Support tools for testing correct bytecode generation.
                                                             (line   28)
* assertNotIsInstance() (unittest.TestCase metodo): Test cases.
                                                             (line  242)
* assertNotIsSubclass() (unittest.TestCase metodo): Test cases.
                                                             (line  252)
* assertNotRegex() (unittest.TestCase metodo): Test cases.   (line  583)
* assertNotStartsWith() (unittest.TestCase metodo): Test cases.
                                                             (line  619)
* assertRaises() (unittest.TestCase metodo): Test cases.     (line  292)
* assertRaisesRegex() (unittest.TestCase metodo): Test cases.
                                                             (line  333)
* assertRegex() (unittest.TestCase metodo): Test cases.      (line  583)
* assertSequenceEqual() (unittest.TestCase metodo): Test cases.
                                                             (line  702)
* assertSetEqual() (unittest.TestCase metodo): Test cases.   (line  728)
* assertStartsWith() (unittest.TestCase metodo): Test cases. (line  617)
* assertTrue() (unittest.TestCase metodo): Test cases.       (line  208)
* assertTupleEqual() (unittest.TestCase metodo): Test cases. (line  717)
* assertWarns() (unittest.TestCase metodo): Test cases.      (line  361)
* assertWarnsRegex() (unittest.TestCase metodo): Test cases. (line  402)
* Assign (classe in ast):                Statements.         (line    6)
* assignment expression:                 Boolean operations. (line   38)
* assignment;expression:                 Boolean operations. (line   37)
* assignment;statement:                  Mutable sequences.  (line    6)
* assignment;statement <1>:              Assignment statements.
                                                             (line    6)
* assume_default_colors() (nel modulo curses): Functions<5>. (line   18)
* AST (classe in ast):                   Node classes.       (line    6)
* ast command line option; -a:           Command-line usage<7>.
                                                             (line   29)
* ast command line option; -feature-version: Command-line usage<7>.
                                                             (line   38)
* ast command line option; -h:           Command-line usage<7>.
                                                             (line   15)
* ast command line option; -help:        Command-line usage<7>.
                                                             (line   15)
* ast command line option; -i:           Command-line usage<7>.
                                                             (line   33)
* ast command line option; -include-attributes: Command-line usage<7>.
                                                             (line   29)
* ast command line option; -indent:      Command-line usage<7>.
                                                             (line   33)
* ast command line option; -m:           Command-line usage<7>.
                                                             (line   19)
* ast command line option; -mode:        Command-line usage<7>.
                                                             (line   19)
* ast command line option; -no-type-comments: Command-line usage<7>.
                                                             (line   25)
* ast command line option; -O:           Command-line usage<7>.
                                                             (line   45)
* ast command line option; -optimize:    Command-line usage<7>.
                                                             (line   45)
* ast command line option; -show-empty:  Command-line usage<7>.
                                                             (line   52)
* astimezone() (datetime.datetime metodo): datetime Objects. (line  479)
* astuple() (nel modulo dataclasses):    Module contents<4>. (line  376)
* async for;in comprehensions:           Displays for lists sets and dictionaries.
                                                             (line   14)
* AsyncContextDecorator (classe in contextlib): Utilities.   (line  462)
* AsyncContextManager (classe in typing): Aliases to contextlib ABCs.
                                                             (line   24)
* asynccontextmanager() (nel modulo contextlib): Utilities.  (line   94)
* AsyncExitStack (classe in contextlib): Utilities.          (line  621)
* AsyncFor (classe in ast):              Async and await.    (line   34)
* AsyncFunctionDef (classe in ast):      Async and await.    (line    6)
* AsyncGenerator (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  186)
* AsyncGenerator (classe in typing):     Aliases to asynchronous ABCs in collections abc.
                                                             (line   21)
* AsyncGeneratorType (nel modulo types): Standard Interpreter Types.
                                                             (line   49)
* asynchronous context manager:          Glossary.           (line   93)
* asynchronous generator:                Glossary.           (line   99)
* asynchronous generator iterator:       Glossary.           (line  116)
* asynchronous generator;asynchronous iterator: Asynchronous generator functions.
                                                             (line    6)
* asynchronous generator;function:       Asynchronous generator functions.
                                                             (line    6)
* asynchronous iterable:                 Glossary.           (line  133)
* asynchronous iterator:                 Glossary.           (line  139)
* asyncio.subprocess.DEVNULL (variabile built-in): Constants<7>.
                                                             (line   23)
* asyncio.subprocess.PIPE (variabile built-in): Constants<7>.
                                                             (line    6)
* asyncio.subprocess.Process (classe built-in): Interacting with Subprocesses.
                                                             (line   11)
* asyncio.subprocess.STDOUT (variabile built-in): Constants<7>.
                                                             (line   17)
* AsyncIterable (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  172)
* AsyncIterable (classe in typing):      Aliases to asynchronous ABCs in collections abc.
                                                             (line   39)
* AsyncIterator (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  179)
* AsyncIterator (classe in typing):      Aliases to asynchronous ABCs in collections abc.
                                                             (line   49)
* AsyncMock (classe in unittest.mock):   The Mock Class.     (line  703)
* AsyncResult (classe in multiprocessing.pool): Process Pools.
                                                             (line  199)
* asyncSetUp() (unittest.IsolatedAsyncioTestCase metodo): Test cases.
                                                             (line  932)
* asyncTearDown() (unittest.IsolatedAsyncioTestCase metodo): Test cases.
                                                             (line  941)
* AsyncWith (classe in ast):             Async and await.    (line   34)
* AT (nel modulo token):                 token — Constants used with Python parse trees.
                                                             (line  338)
* at_eof() (asyncio.StreamReader metodo): StreamReader.      (line   85)
* atan() (nel modulo cmath):             Trigonometric functions<2>.
                                                             (line   17)
* atan() (nel modulo math):              Trigonometric functions.
                                                             (line   16)
* atan2() (nel modulo math):             Trigonometric functions.
                                                             (line   21)
* atanh() (nel modulo cmath):            Hyperbolic functions<2>.
                                                             (line   17)
* atanh() (nel modulo math):             Hyperbolic functions.
                                                             (line   17)
* ATEQUAL (nel modulo token):            token — Constants used with Python parse trees.
                                                             (line  341)
* atexit (weakref.finalize attributo):   weakref — Weak references.
                                                             (line  317)
* athrow() (agen metodo):                Asynchronous generator-iterator methods.
                                                             (line   43)
* atof() (nel modulo locale):            locale — Internationalization services.
                                                             (line  525)
* atoi() (nel modulo locale):            locale — Internationalization services.
                                                             (line  531)
* atom:                                  Atoms.              (line    6)
* atomic operation:                      Glossary.           (line  148)
* attach_mock() (unittest.mock.Mock metodo): The Mock Class. (line  258)
* attach() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  168)
* attached thread state:                 Glossary.           (line  158)
* attempted (doctest.TestResults attributo): TestResults objects.
                                                             (line   12)
* AttlistDeclHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  296)
* attrgetter() (nel modulo operator):    operator — Standard operators as functions.
                                                             (line  246)
* attrib (xml.etree.ElementTree.Element attributo): Element Objects.
                                                             (line   45)
* attribute:                             The standard type hierarchy.
                                                             (line   13)
* attribute <1>:                         Glossary.           (line  181)
* Attribute (classe in ast):             Expressions<2>.     (line  170)
* attribute;assignment:                  Assignment statements.
                                                             (line    6)
* attribute;assignment <1>:              Assignment statements.
                                                             (line   76)
* attribute;deletion:                    The del statement.  (line   20)
* attribute;reference:                   Attribute references.
                                                             (line    6)
* AttributeError:                        Concrete exceptions.
                                                             (line   12)
* attributes (xml.dom.Node attributo):   Node Objects.       (line   26)
* AttributesImpl (classe in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers.
                                                             (line   69)
* AttributesNSImpl (classe in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers.
                                                             (line   80)
* attroff() (curses.window metodo):      Window Objects.     (line   55)
* attron() (curses.window metodo):       Window Objects.     (line   60)
* attrset() (curses.window metodo):      Window Objects.     (line   65)
* audit events:                          Debugging and Profiling.
                                                             (line   13)
* audit() (nel modulo sys):              sys — System-specific parameters and functions.
                                                             (line   92)
* auditing:                              sys — System-specific parameters and functions.
                                                             (line   94)
* AugAssign (classe in ast):             Statements.         (line   95)
* augmented;assignment:                  Augmented assignment statements.
                                                             (line    6)
* AUGUST (nel modulo calendar):          calendar — General calendar-related functions.
                                                             (line  490)
* auth() (ftplib.FTP_TLS metodo):        FTP_TLS objects.    (line   88)
* auth() (smtplib.SMTP metodo):          SMTP Objects.       (line  141)
* authenticate() (imaplib.IMAP4 metodo): IMAP4 Objects.      (line   37)
* AuthenticationError:                   Process and exceptions.
                                                             (line  294)
* authenticators() (netrc.netrc metodo): netrc Objects.      (line    8)
* authkey (multiprocessing.Process attributo): Process and exceptions.
                                                             (line  174)
* auto (classe in enum):                 Utilities and Decorators.
                                                             (line    6)
* autocommit (sqlite3.Connection attributo): Connection objects.
                                                             (line  733)
* autorange() (timeit.Timer metodo):     Python Interface.   (line   95)
* available_timezones() (nel modulo zoneinfo): Functions<2>. (line    6)
* avoids_symlink_attacks (shutil.rmtree attributo): Directory and files operations.
                                                             (line  345)
* Await (classe in ast):                 Async and await.    (line   14)
* await_args (unittest.mock.AsyncMock attributo): The Mock Class.
                                                             (line  918)
* await_args_list (unittest.mock.AsyncMock attributo): The Mock Class.
                                                             (line  936)
* await_count (unittest.mock.AsyncMock attributo): The Mock Class.
                                                             (line  902)
* await;in comprehensions:               Displays for lists sets and dictionaries.
                                                             (line   45)
* awaitable:                             Glossary.           (line  194)
* Awaitable (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  132)
* Awaitable (classe in typing):          Aliases to asynchronous ABCs in collections abc.
                                                             (line   59)
* b';bytes literal:                      Unrecognized escape sequences.
                                                             (line   25)
* b";bytes literal:                      Unrecognized escape sequences.
                                                             (line   24)
* b16decode() (nel modulo base64):       RFC 4648 Encodings. (line  123)
* b16encode() (nel modulo base64):       RFC 4648 Encodings. (line  118)
* b2a_base64() (nel modulo binascii):    binascii — Convert between binary and ASCII.
                                                             (line   61)
* b2a_hex() (nel modulo binascii):       binascii — Convert between binary and ASCII.
                                                             (line  114)
* b2a_qp() (nel modulo binascii):        binascii — Convert between binary and ASCII.
                                                             (line   77)
* b2a_uu() (nel modulo binascii):        binascii — Convert between binary and ASCII.
                                                             (line   31)
* b32decode() (nel modulo base64):       RFC 4648 Encodings. (line   78)
* b32encode() (nel modulo base64):       RFC 4648 Encodings. (line   73)
* b32hexdecode() (nel modulo base64):    RFC 4648 Encodings. (line  106)
* b32hexencode() (nel modulo base64):    RFC 4648 Encodings. (line   99)
* b64decode() (nel modulo base64):       RFC 4648 Encodings. (line   25)
* b64encode() (nel modulo base64):       RFC 4648 Encodings. (line   10)
* b85decode() (nel modulo base64):       Base85 Encodings.   (line   84)
* b85encode() (nel modulo base64):       Base85 Encodings.   (line   73)
* Babyl (classe in mailbox):             Babyl objects.      (line    6)
* BabylMessage (classe in mailbox):      BabylMessage objects.
                                                             (line    6)
* back() (nel modulo turtle):            Turtle motion.      (line   24)
* backend (nel modulo readline):         readline — GNU readline interface.
                                                             (line   54)
* backslash character:                   Explicit line joining.
                                                             (line    6)
* backslashreplace_errors() (nel modulo codecs): Error Handlers.
                                                             (line  161)
* backslashreplace;error handler's name: Error Handlers.     (line   15)
* backup() (sqlite3.Connection metodo):  Connection objects. (line  531)
* backward() (nel modulo turtle):        Turtle motion.      (line   24)
* BadGzipFile:                           gzip — Support for gzip files.
                                                             (line   68)
* BadOptionError:                        Exceptions<11>.     (line   21)
* BadStatusLine:                         http client — HTTP protocol client.
                                                             (line  178)
* BadZipFile:                            zipfile — Work with ZIP archives.
                                                             (line   30)
* BadZipfile:                            zipfile — Work with ZIP archives.
                                                             (line   36)
* Barrier (classe in asyncio):           Barrier.            (line    6)
* Barrier (classe in multiprocessing):   Synchronization primitives.
                                                             (line   13)
* Barrier (classe in threading):         Barrier objects.    (line   36)
* Barrier() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  162)
* base_exec_prefix (nel modulo sys):     sys — System-specific parameters and functions.
                                                             (line  123)
* base_prefix (nel modulo sys):          sys — System-specific parameters and functions.
                                                             (line  136)
* base64;encoding:                       base64 — Base16 Base32 Base64 Base85 Data Encodings.
                                                             (line    8)
* BaseCGIHandler (classe in wsgiref.handlers): wsgiref handlers – server/gateway base classes.
                                                             (line   53)
* BaseCookie (classe in http.cookies):   http cookies — HTTP state management.
                                                             (line   40)
* BaseException:                         Base classes.       (line    9)
* BaseExceptionGroup:                    Exception groups.   (line   14)
* BaseHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  323)
* BaseHandler (classe in wsgiref.handlers): wsgiref handlers – server/gateway base classes.
                                                             (line   89)
* BaseHeader (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line   37)
* BaseHTTPRequestHandler (classe in http.server): http server — HTTP servers.
                                                             (line   98)
* BaseManager (classe in multiprocessing.managers): Managers.
                                                             (line   23)
* basename() (nel modulo os.path):       os path — Common pathname manipulations.
                                                             (line   62)
* BaseProtocol (classe in asyncio):      Base Protocols.     (line    6)
* BaseProxy (classe in multiprocessing.managers): Proxy Objects.
                                                             (line   92)
* BaseRequestHandler (classe in socketserver): Request Handler Objects.
                                                             (line    6)
* BaseRotatingHandler (classe in logging.handlers): BaseRotatingHandler.
                                                             (line   12)
* BaseSelector (classe in selectors):    Classes<3>.         (line   53)
* BaseServer (classe in socketserver):   Server Objects<2>.  (line    6)
* BaseTransport (classe in asyncio):     Transports Hierarchy.
                                                             (line    6)
* basicConfig() (nel modulo logging):    Module-Level Functions.
                                                             (line  204)
* BasicContext (nel modulo decimal):     Context objects.    (line   74)
* BasicInterpolation (classe in configparser): Interpolation of values.
                                                             (line   10)
* batched() (nel modulo itertools):      Itertool Functions. (line   73)
* baudrate() (nel modulo curses):        Functions<5>.       (line   33)
* bbox() (tkinter.ttk.Treeview metodo):  ttk Treeview.       (line    8)
* BDADDR_ANY (nel modulo socket):        Constants<8>.       (line  315)
* BDADDR_BREDR (nel modulo socket):      Constants<8>.       (line  323)
* BDADDR_LE_PUBLIC (nel modulo socket):  Constants<8>.       (line  323)
* BDADDR_LE_RANDOM (nel modulo socket):  Constants<8>.       (line  323)
* BDADDR_LOCAL (nel modulo socket):      Constants<8>.       (line  315)
* Bdb (classe in bdb):                   bdb — Debugger framework.
                                                             (line  129)
* BdbQuit:                               bdb — Debugger framework.
                                                             (line   15)
* BDFL:                                  Glossary.           (line  200)
* beep() (nel modulo curses):            Functions<5>.       (line   41)
* Beep() (nel modulo winsound):          winsound — Sound-playing interface for Windows.
                                                             (line   14)
* begin_fill() (nel modulo turtle):      Filling.            (line   35)
* begin_poly() (nel modulo turtle):      Special Turtle methods.
                                                             (line   18)
* BEL (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   40)
* BELOW_NORMAL_PRIORITY_CLASS (nel modulo subprocess): Windows Constants.
                                                             (line   75)
* below() (curses.panel.Panel metodo):   Panel Objects.      (line   17)
* benchmarking:                          Functions<4>.       (line  216)
* benchmarking <1>:                      Functions<4>.       (line  247)
* benchmarking <2>:                      Functions<4>.       (line  616)
* Benchmarking:                          timeit — Measure execution time of small code snippets.
                                                             (line    8)
* betavariate() (nel modulo random):     Real-valued distributions.
                                                             (line   33)
* bgcolor() (nel modulo turtle):         Window control.     (line    6)
* bgpic() (nel modulo turtle):           Window control.     (line   48)
* bidirectional() (nel modulo unicodedata): unicodedata — Unicode Database.
                                                             (line   90)
* bigaddrspacetest() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  593)
* BigEndianStructure (classe in ctypes): Structured data types.
                                                             (line   25)
* BigEndianUnion (classe in ctypes):     Structured data types.
                                                             (line   13)
* bigmemtest() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  577)
* bin() (nel modulo enum):               Utilities and Decorators.
                                                             (line  109)
* binario;letterali:                     Tipi Numerici — int float complex.
                                                             (line   19)
* Binary (classe in xmlrpc.client):      Binary Objects.     (line    6)
* binary file:                           Glossary.           (line  205)
* binary literal:                        Numeric literals.   (line    6)
* binary semaphores:                     _thread — Low-level threading API.
                                                             (line    6)
* BINARY_OP (opcode):                    Python Bytecode Instructions.
                                                             (line  256)
* BINARY_SLICE (opcode):                 Python Bytecode Instructions.
                                                             (line  287)
* binary;arithmetic;operation:           Binary arithmetic operations.
                                                             (line    6)
* binary;bitwise;operation:              Binary bitwise operations.
                                                             (line    6)
* binaryfunc (C type):                   Slot Type typedefs. (line  110)
* BinaryIO (classe in typing):           ABCs and Protocols for working with I/O.
                                                             (line    6)
* bind (widgets):                        Bindings and Events.
                                                             (line    6)
* bind_partial() (inspect.Signature metodo): Introspecting callables with the Signature object.
                                                             (line  138)
* bind_port() (nel modulo test.support.socket_helper): test support socket_helper — Utilities for socket tests.
                                                             (line   37)
* bind_textdomain_codeset() (nel modulo locale): Access to message catalogs.
                                                             (line   16)
* bind_unix_socket() (nel modulo test.support.socket_helper): test support socket_helper — Utilities for socket tests.
                                                             (line   54)
* bind() (inspect.Signature metodo):     Introspecting callables with the Signature object.
                                                             (line  131)
* bind() (socket.socket metodo):         Socket Objects.     (line   31)
* binding;name:                          Binding of names.   (line    6)
* binding;name <1>:                      Assignment statements.
                                                             (line    6)
* bindtextdomain() (nel modulo gettext): GNU gettext API.    (line   14)
* bindtextdomain() (nel modulo locale):  Access to message catalogs.
                                                             (line   14)
* binomialvariate() (nel modulo random): Discrete distributions.
                                                             (line    8)
* BinOp (classe in ast):                 Expressions<2>.     (line   41)
* bisect_left() (nel modulo bisect):     bisect — Array bisection algorithm.
                                                             (line   33)
* bisect_right() (nel modulo bisect):    bisect — Array bisection algorithm.
                                                             (line   58)
* bisect() (nel modulo bisect):          bisect — Array bisection algorithm.
                                                             (line   58)
* bit_count() (int metodo):              Metodi Aggiuntivi sui Tipi Integer.
                                                             (line   36)
* bit_length() (int metodo):             Metodi Aggiuntivi sui Tipi Integer.
                                                             (line    9)
* bit_offset (ctypes.CField attributo):  Structured data types.
                                                             (line  285)
* bit_size (ctypes.CField attributo):    Structured data types.
                                                             (line  285)
* BitAnd (classe in ast):                Expressions<2>.     (line   53)
* BitOr (classe in ast):                 Expressions<2>.     (line   53)
* bits_per_digit (sys.int_info attributo): sys — System-specific parameters and functions.
                                                             (line 1198)
* bitwise;and:                           Binary bitwise operations.
                                                             (line   12)
* bitwise;operazioni:                    Operazioni Bitwise sui Tipi Integer.
                                                             (line    6)
* bitwise;or:                            Binary bitwise operations.
                                                             (line   20)
* bitwise;xor:                           Binary bitwise operations.
                                                             (line   16)
* BitXor (classe in ast):                Expressions<2>.     (line   53)
* bk() (nel modulo turtle):              Turtle motion.      (line   24)
* bkgd() (curses.window metodo):         Window Objects.     (line   70)
* bkgdset() (curses.window metodo):      Window Objects.     (line   82)
* blake2b, blake2s:                      BLAKE2.             (line    6)
* blake2b.MAX_DIGEST_SIZE (nel modulo hashlib): Constants<5>.
                                                             (line   24)
* blake2b.MAX_KEY_SIZE (nel modulo hashlib): Constants<5>.   (line   18)
* blake2b.PERSON_SIZE (nel modulo hashlib): Constants<5>.    (line   12)
* blake2b.SALT_SIZE (nel modulo hashlib): Constants<5>.      (line    6)
* blake2b() (nel modulo hashlib):        Creating hash objects.
                                                             (line    8)
* blake2s.MAX_DIGEST_SIZE (nel modulo hashlib): Constants<5>.
                                                             (line   26)
* blake2s.MAX_KEY_SIZE (nel modulo hashlib): Constants<5>.   (line   20)
* blake2s.PERSON_SIZE (nel modulo hashlib): Constants<5>.    (line   14)
* blake2s.SALT_SIZE (nel modulo hashlib): Constants<5>.      (line    8)
* blake2s() (nel modulo hashlib):        Creating hash objects.
                                                             (line   13)
* blank line:                            Blank lines.        (line    6)
* BLKTYPE (nel modulo tarfile):          tarfile — Read and write tar archive files.
                                                             (line  341)
* Blob (classe in sqlite3):              Blob objects.       (line    6)
* blobopen() (sqlite3.Connection metodo): Connection objects.
                                                             (line   34)
* block:                                 Structure of a program.
                                                             (line    6)
* block_on_close (socketserver.ThreadingMixIn attributo): Server Creation Notes.
                                                             (line   45)
* block_size (hmac.HMAC attributo):      hmac — Keyed-Hashing for Message Authentication.
                                                             (line   98)
* blocked_domains() (http.cookiejar.DefaultCookiePolicy metodo): DefaultCookiePolicy Objects.
                                                             (line   52)
* BlockingIOError:                       OS exceptions.      (line    9)
* BlockingIOError <1>:                   High-level Module Interface.
                                                             (line   67)
* blocksize (http.client.HTTPConnection attributo): HTTPConnection Objects.
                                                             (line  162)
* BNF:                                   Notation.           (line    6)
* BNF <1>:                               Expressions.        (line    6)
* body_encode() (email.charset.Charset metodo): email charset Representing character sets.
                                                             (line  135)
* body_encoding (email.charset.Charset attributo): email charset Representing character sets.
                                                             (line   67)
* body_line_iterator() (nel modulo email.iterators): email iterators Iterators.
                                                             (line   14)
* body() (tkinter.simpledialog.Dialog metodo): tkinter simpledialog — Standard Tkinter input dialogs.
                                                             (line   25)
* BOLD (nel modulo tkinter.font):        tkinter font — Tkinter font wrapper.
                                                             (line   15)
* BOM (nel modulo codecs):               codecs — Codec registry and base classes.
                                                             (line  275)
* BOM_BE (nel modulo codecs):            codecs — Codec registry and base classes.
                                                             (line  275)
* BOM_LE (nel modulo codecs):            codecs — Codec registry and base classes.
                                                             (line  275)
* BOM_UTF16 (nel modulo codecs):         codecs — Codec registry and base classes.
                                                             (line  275)
* BOM_UTF16_BE (nel modulo codecs):      codecs — Codec registry and base classes.
                                                             (line  275)
* BOM_UTF16_LE (nel modulo codecs):      codecs — Codec registry and base classes.
                                                             (line  275)
* BOM_UTF32 (nel modulo codecs):         codecs — Codec registry and base classes.
                                                             (line  275)
* BOM_UTF32_BE (nel modulo codecs):      codecs — Codec registry and base classes.
                                                             (line  275)
* BOM_UTF32_LE (nel modulo codecs):      codecs — Codec registry and base classes.
                                                             (line  275)
* BOM_UTF8 (nel modulo codecs):          codecs — Codec registry and base classes.
                                                             (line  275)
* bool (classe built-in):                Funzioni Incorporate.
                                                             (line  136)
* BOOLEAN_STATES (configparser.ConfigParser attributo): Customizing Parser Behaviour.
                                                             (line  246)
* Boolean;operation:                     Boolean operations. (line    6)
* Booleano;operazioni:                   Test del Valore di Verità.
                                                             (line    6)
* Booleano;operazioni <1>:               Operazioni Booleane — and or not.
                                                             (line    6)
* Booleano;tipo:                         Funzioni Incorporate.
                                                             (line  147)
* Booleano;valori:                       Tipo Booleano - bool.
                                                             (line    9)
* BooleanOptionalAction (classe in argparse): Action classes.
                                                             (line   64)
* BoolOp (classe in ast):                Expressions<2>.     (line   69)
* bootstrap() (nel modulo ensurepip):    Module API.         (line   13)
* border() (curses.window metodo):       Window Objects.     (line   93)
* borrowed reference:                    Glossary.           (line  216)
* bottom_panel() (nel modulo curses.panel): Functions<6>.    (line    8)
* bottom() (curses.panel.Panel metodo):  Panel Objects.      (line   21)
* BoundArguments (classe in inspect):    Introspecting callables with the Signature object.
                                                             (line  347)
* BoundaryError:                         email errors Exception and Defect classes.
                                                             (line   38)
* BoundedSemaphore (classe in asyncio):  BoundedSemaphore.   (line    6)
* BoundedSemaphore (classe in multiprocessing): Synchronization primitives.
                                                             (line   22)
* BoundedSemaphore (classe in threading): Semaphore objects. (line   74)
* BoundedSemaphore() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  169)
* bounds() (compression.zstd.CompressionParameter metodo): Advanced parameter control.
                                                             (line   28)
* bounds() (compression.zstd.DecompressionParameter metodo): Advanced parameter control.
                                                             (line  279)
* box() (curses.window metodo):          Window Objects.     (line  132)
* bpbynumber (bdb.Breakpoint attributo): bdb — Debugger framework.
                                                             (line  110)
* bpformat() (bdb.Breakpoint metodo):    bdb — Debugger framework.
                                                             (line   56)
* bplist (bdb.Breakpoint attributo):     bdb — Debugger framework.
                                                             (line  115)
* bpprint() (bdb.Breakpoint metodo):     bdb — Debugger framework.
                                                             (line   75)
* BRANCH_LEFT (monitoring event):        Events.             (line    8)
* BRANCH_RIGHT (monitoring event):       Events.             (line   17)
* Break (classe in ast):                 Control flow.       (line   99)
* break (pdb command):                   Debugger commands.  (line  106)
* break_anywhere() (bdb.Bdb metodo):     bdb — Debugger framework.
                                                             (line  289)
* break_here() (bdb.Bdb metodo):         bdb — Debugger framework.
                                                             (line  280)
* break_long_words (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  254)
* break_on_hyphens (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  264)
* Breakpoint (classe in bdb):            bdb — Debugger framework.
                                                             (line   22)
* breakpointhook() (nel modulo sys):     sys — System-specific parameters and functions.
                                                             (line  241)
* breakpoints:                           Help menu Shell and Editor.
                                                             (line   29)
* broadcast_address (ipaddress.IPv4Network attributo): Network objects.
                                                             (line   91)
* broadcast_address (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  312)
* broken (asyncio.Barrier attributo):    Barrier.            (line  103)
* broken (threading.Barrier attributo):  Barrier objects.    (line  101)
* BrokenBarrierError:                    Barrier objects.    (line  106)
* BrokenBarrierError <1>:                Barrier.            (line  108)
* BrokenExecutor:                        Exception classes.  (line   18)
* BrokenInterpreterPool:                 Exception classes.  (line   41)
* BrokenPipeError:                       OS exceptions.      (line   38)
* BrokenProcessPool:                     Exception classes.  (line   49)
* BrokenThreadPool:                      Exception classes.  (line   33)
* BROWSER:                               webbrowser.         (line    6)
* BROWSER <1>:                           webbrowser.         (line   10)
* BROWSER <2>:                           Library<23>.        (line  420)
* BROWSER <3>:                           Library<23>.        (line  424)
* BROWSER <4>:                           webbrowser — Convenient web-browser controller.
                                                             (line   20)
* BROWSER <5>:                           webbrowser — Convenient web-browser controller.
                                                             (line   30)
* BROWSER <6>:                           webbrowser — Convenient web-browser controller.
                                                             (line   41)
* BROWSER <7>:                           Command-line interface<6>.
                                                             (line   86)
* BS (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line   43)
* BsdDbShelf (classe in shelve):         Restrictions.       (line   60)
* btlazy2 (compression.zstd.Strategy attributo): Advanced parameter control.
                                                             (line  319)
* btopt (compression.zstd.Strategy attributo): Advanced parameter control.
                                                             (line  321)
* BTPROTO_HCI (nel modulo socket):       Constants<8>.       (line  307)
* BTPROTO_L2CAP (nel modulo socket):     Constants<8>.       (line  307)
* BTPROTO_RFCOMM (nel modulo socket):    Constants<8>.       (line  307)
* BTPROTO_SCO (nel modulo socket):       Constants<8>.       (line  307)
* btultra (compression.zstd.Strategy attributo): Advanced parameter control.
                                                             (line  323)
* btultra2 (compression.zstd.Strategy attributo): Advanced parameter control.
                                                             (line  325)
* buf (multiprocessing.shared_memory.SharedMemory attributo): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  116)
* Buffer (classe in collections.abc):    Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  196)
* buffer (io.TextIOBase attributo):      Text I/O<2>.        (line   30)
* buffer (unittest.TestResult attributo): Loading and running tests.
                                                             (line  295)
* buffer interface;(see buffer protocol): Iterator Protocol. (line   65)
* buffer object;(see buffer protocol):   Iterator Protocol.  (line   64)
* buffer protocol:                       Iterator Protocol.  (line   65)
* buffer_info() (array.array metodo):    array — Efficient arrays of numeric values.
                                                             (line  126)
* buffer_size (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  170)
* buffer_text (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  177)
* buffer_updated() (asyncio.BufferedProtocol metodo): Buffered Streaming Protocols.
                                                             (line   33)
* buffer_used (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  188)
* BufferedIOBase (classe in io):         I/O Base Classes.   (line  224)
* BufferedProtocol (classe in asyncio):  Base Protocols.     (line   15)
* BufferedRandom (classe in io):         Buffered Streams.   (line  140)
* BufferedReader (classe in io):         Buffered Streams.   (line   59)
* BufferedRWPair (classe in io):         Buffered Streams.   (line  155)
* BufferedWriter (classe in io):         Buffered Streams.   (line   98)
* BufferError:                           Base classes.       (line   78)
* BufferFlags (classe in inspect):       Buffer flags.       (line    6)
* BufferingFormatter (classe in logging): Formatter Objects. (line  131)
* BufferingHandler (classe in logging.handlers): MemoryHandler.
                                                             (line   19)
* BufferTooShort:                        Process and exceptions.
                                                             (line  286)
* BUILD_INTERPOLATION (opcode):          Python Bytecode Instructions.
                                                             (line  666)
* BUILD_LIST (opcode):                   Python Bytecode Instructions.
                                                             (line  707)
* BUILD_MAP (opcode):                    Python Bytecode Instructions.
                                                             (line  715)
* build_opener() (nel modulo urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  120)
* BUILD_SET (opcode):                    Python Bytecode Instructions.
                                                             (line  711)
* BUILD_SLICE (opcode):                  Python Bytecode Instructions.
                                                             (line 1190)
* BUILD_STRING (opcode):                 Python Bytecode Instructions.
                                                             (line  725)
* BUILD_TEMPLATE (opcode):               Python Bytecode Instructions.
                                                             (line  654)
* BUILD_TUPLE (opcode):                  Python Bytecode Instructions.
                                                             (line  694)
* built-in function; __import__():       Funzioni Incorporate.
                                                             (line 2286)
* built-in function; abs():              Funzioni Incorporate.
                                                             (line   43)
* built-in function; aiter():            Funzioni Incorporate.
                                                             (line   50)
* built-in function; all():              Funzioni Incorporate.
                                                             (line   61)
* built-in function; anext():            Funzioni Incorporate.
                                                             (line   72)
* built-in function; any():              Funzioni Incorporate.
                                                             (line   91)
* built-in function; ascii():            Funzioni Incorporate.
                                                             (line  102)
* built-in function; bin():              Funzioni Incorporate.
                                                             (line  111)
* built-in function; breakpoint():       Funzioni Incorporate.
                                                             (line  149)
* built-in function; callable():         Funzioni Incorporate.
                                                             (line  230)
* built-in function; chr():              Funzioni Incorporate.
                                                             (line  243)
* built-in function; classmethod():      Funzioni Incorporate.
                                                             (line  254)
* built-in function; compile():          Funzioni Incorporate.
                                                             (line  293)
* built-in function; delattr():          Funzioni Incorporate.
                                                             (line  456)
* built-in function; dir():              Funzioni Incorporate.
                                                             (line  480)
* built-in function; divmod():           Funzioni Incorporate.
                                                             (line  543)
* built-in function; enumerate():        Funzioni Incorporate.
                                                             (line  555)
* built-in function; eval():             Funzioni Incorporate.
                                                             (line  578)
* built-in function; exec():             Funzioni Incorporate.
                                                             (line  657)
* built-in function; filter():           Funzioni Incorporate.
                                                             (line  732)
* built-in function; format():           Funzioni Incorporate.
                                                             (line  819)
* built-in function; getattr():          Funzioni Incorporate.
                                                             (line  853)
* built-in function; globals():          Funzioni Incorporate.
                                                             (line  871)
* built-in function; hasattr():          Funzioni Incorporate.
                                                             (line  878)
* built-in function; hash():             Funzioni Incorporate.
                                                             (line  886)
* built-in function; help():             Funzioni Incorporate.
                                                             (line  899)
* built-in function; hex():              Funzioni Incorporate.
                                                             (line  925)
* built-in function; id():               Funzioni Incorporate.
                                                             (line  956)
* built-in function; input():            Funzioni Incorporate.
                                                             (line  968)
* built-in function; isinstance():       Funzioni Incorporate.
                                                             (line 1070)
* built-in function; issubclass():       Funzioni Incorporate.
                                                             (line 1087)
* built-in function; iter():             Funzioni Incorporate.
                                                             (line 1101)
* built-in function; len():              Funzioni Incorporate.
                                                             (line 1132)
* built-in function; locals():           Funzioni Incorporate.
                                                             (line 1149)
* built-in function; map():              Funzioni Incorporate.
                                                             (line 1204)
* built-in function; max():              Funzioni Incorporate.
                                                             (line 1218)
* built-in function; min():              Funzioni Incorporate.
                                                             (line 1255)
* built-in function; multiprocessing.Manager(): Managers.    (line   12)
* built-in function; next():             Funzioni Incorporate.
                                                             (line 1287)
* built-in function; oct():              Funzioni Incorporate.
                                                             (line 1307)
* built-in function; open():             Funzioni Incorporate.
                                                             (line 1331)
* built-in function; ord():              Funzioni Incorporate.
                                                             (line 1585)
* built-in function; pow():              Funzioni Incorporate.
                                                             (line 1598)
* built-in function; print():            Funzioni Incorporate.
                                                             (line 1641)
* built-in function; property.deleter(): Funzioni Incorporate.
                                                             (line 1720)
* built-in function; property.getter():  Funzioni Incorporate.
                                                             (line 1716)
* built-in function; property.setter():  Funzioni Incorporate.
                                                             (line 1718)
* built-in function; repr():             Funzioni Incorporate.
                                                             (line 1771)
* built-in function; reversed():         Funzioni Incorporate.
                                                             (line 1796)
* built-in function; round():            Funzioni Incorporate.
                                                             (line 1804)
* built-in function; setattr():          Funzioni Incorporate.
                                                             (line 1842)
* built-in function; sorted():           Funzioni Incorporate.
                                                             (line 1894)
* built-in function; staticmethod():     Funzioni Incorporate.
                                                             (line 1931)
* built-in function; sum():              Funzioni Incorporate.
                                                             (line 1991)
* built-in function; vars():             Funzioni Incorporate.
                                                             (line 2162)
* built-in function; zip():              Funzioni Incorporate.
                                                             (line 2187)
* built-in function;__import__:          Importing Modules<2>.
                                                             (line   32)
* built-in function;abs:                 Emulating numeric types.
                                                             (line  121)
* built-in function;abs <1>:             Number Protocol.    (line  101)
* built-in function;ascii:               Object Protocol.    (line  345)
* built-in function;bytes:               Basic customization.
                                                             (line  148)
* built-in function;bytes <1>:           Object Protocol.    (line  368)
* built-in function;call:                Calls.              (line  143)
* built-in function;chr:                 Immutable sequences.
                                                             (line   15)
* built-in function;classmethod:         Implementing functions and methods.
                                                             (line  195)
* built-in function;compile:             The global statement.
                                                             (line   23)
* built-in function;compile <1>:         Standard Interpreter Types.
                                                             (line   58)
* built-in function;compile <2>:         Importing Modules<2>.
                                                             (line  133)
* built-in function;complex:             Emulating numeric types.
                                                             (line  128)
* built-in function;divmod:              Emulating numeric types.
                                                             (line   26)
* built-in function;divmod <1>:          Emulating numeric types.
                                                             (line   57)
* built-in function;divmod <2>:          Number Protocol.    (line   72)
* built-in function;eval:                The global statement.
                                                             (line   23)
* built-in function;eval <1>:            Expression input.   (line    6)
* built-in function;eval <2>:            Functions<3>.       (line   87)
* built-in function;eval <3>:            PrettyPrinter Objects.
                                                             (line   69)
* built-in function;exec:                The global statement.
                                                             (line   23)
* built-in function;float:               Emulating numeric types.
                                                             (line  128)
* built-in function;float <1>:           Number Protocol.    (line  272)
* built-in function;hash:                Basic customization.
                                                             (line  242)
* built-in function;hash <1>:            Object Protocol.    (line  419)
* built-in function;hash <2>:            PyTypeObject Slots. (line  452)
* built-in function;id:                  Objects values and types.
                                                             (line   10)
* built-in function;int:                 Emulating numeric types.
                                                             (line  128)
* built-in function;int <1>:             Number Protocol.    (line  264)
* built-in function;len:                 Sequences.          (line    6)
* built-in function;len <1>:             Set types.          (line    6)
* built-in function;len <2>:             Mappings.           (line    6)
* built-in function;len <3>:             Emulating container types.
                                                             (line   46)
* built-in function;len <4>:             Object Protocol.    (line  466)
* built-in function;len <5>:             Sequence Protocol.  (line   16)
* built-in function;len <6>:             Mapping Protocol.   (line   19)
* built-in function;len <7>:             List Objects.       (line   41)
* built-in function;len <8>:             Dictionary Objects. (line  238)
* built-in function;len <9>:             Set Objects.        (line  100)
* built-in function;open:                I/O objects also known as file objects.
                                                             (line    6)
* built-in function;ord:                 Immutable sequences.
                                                             (line   15)
* built-in function;pow:                 Emulating numeric types.
                                                             (line   26)
* built-in function;pow <1>:             Emulating numeric types.
                                                             (line   26)
* built-in function;pow <2>:             Emulating numeric types.
                                                             (line   57)
* built-in function;pow <3>:             Number Protocol.    (line   81)
* built-in function;pow <4>:             Number Protocol.    (line  212)
* built-in function;print:               Basic customization.
                                                             (line  153)
* built-in function;range:               The for statement.  (line   37)
* built-in function;repr:                Expression statements.
                                                             (line   17)
* built-in function;repr <1>:            Finalization and De-allocation.
                                                             (line   94)
* built-in function;repr <2>:            Object Protocol.    (line  332)
* built-in function;repr <3>:            PyTypeObject Slots. (line  387)
* built-in function;round:               Emulating numeric types.
                                                             (line  151)
* built-in function;slice:               Slice objects.      (line    6)
* built-in function;slice <1>:           Python Bytecode Instructions.
                                                             (line 1192)
* built-in function;staticmethod:        Implementing functions and methods.
                                                             (line  203)
* built-in function;tuple:               Sequence Protocol.  (line  127)
* built-in function;tuple <1>:           List Objects.       (line  162)
* built-in function;type:                Objects values and types.
                                                             (line   10)
* built-in function;type <1>:            Metaclasses.        (line    6)
* built-in function;type <2>:            Object Protocol.    (line  448)
* built-in method;call:                  Calls.              (line  143)
* built-in;method:                       Built-in methods.   (line    6)
* builtin_module_names (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line  156)
* BuiltinFunctionType (nel modulo types): Standard Interpreter Types.
                                                             (line   81)
* BuiltinImporter (classe in importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line   67)
* BuiltinMethodType (nel modulo types):  Standard Interpreter Types.
                                                             (line   81)
* burst() (imaplib.IMAP4.Idler metodo):  IMAP4 Objects.      (line  161)
* busy_retry() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  214)
* BUTTON_ALT (nel modulo curses):        Constants<6>.       (line  627)
* BUTTON_CTRL (nel modulo curses):       Constants<6>.       (line  624)
* BUTTON_SHIFT (nel modulo curses):      Constants<6>.       (line  621)
* buttonbox() (tkinter.simpledialog.Dialog metodo): tkinter simpledialog — Standard Tkinter input dialogs.
                                                             (line   30)
* BUTTONn_CLICKED (nel modulo curses):   Constants<6>.       (line  612)
* BUTTONn_DOUBLE_CLICKED (nel modulo curses): Constants<6>.  (line  615)
* BUTTONn_PRESSED (nel modulo curses):   Constants<6>.       (line  606)
* BUTTONn_RELEASED (nel modulo curses):  Constants<6>.       (line  609)
* BUTTONn_TRIPLE_CLICKED (nel modulo curses): Constants<6>.  (line  618)
* bye() (nel modulo turtle):             Methods specific to Screen not inherited from TurtleScreen.
                                                             (line    6)
* byref() (nel modulo ctypes):           Utility functions.  (line   19)
* byte:                                  Immutable sequences.
                                                             (line   39)
* byte_offset (ctypes.CField attributo): Structured data types.
                                                             (line  256)
* byte_size (ctypes.CField attributo):   Structured data types.
                                                             (line  264)
* bytearray:                             Mutable sequences.  (line   25)
* bytearray (classe built-in):           Oggetti Bytearray.  (line    9)
* bytearray;formattazione:               Formattazione Bytes stile printf.
                                                             (line    6)
* bytearray;interpolazione:              Formattazione Bytes stile printf.
                                                             (line    6)
* bytearray;metodi:                      Operazioni su Bytes e Bytearray.
                                                             (line    6)
* bytecode:                              Code objects.       (line    6)
* bytecode <1>:                          Glossary.           (line  249)
* Bytecode (classe in dis):              Bytecode analysis.  (line   12)
* BYTECODE_SUFFIXES (nel modulo importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line   40)
* Bytecode.codeobj (nel modulo dis):     Bytecode analysis.  (line   54)
* Bytecode.first_line (nel modulo dis):  Bytecode analysis.  (line   58)
* BytecodeTestCase (classe in test.support.bytecode_helper): test support bytecode_helper — Support tools for testing correct bytecode generation.
                                                             (line   13)
* byteorder (nel modulo sys):            sys — System-specific parameters and functions.
                                                             (line  149)
* bytes:                                 Immutable sequences.
                                                             (line   39)
* bytes (classe built-in):               Oggetti bytes.      (line   12)
* bytes (uuid.UUID attributo):           uuid — UUID objects according to RFC 9562.
                                                             (line   89)
* bytes literal:                         Literals.           (line   15)
* bytes_le (uuid.UUID attributo):        uuid — UUID objects according to RFC 9562.
                                                             (line   94)
* bytes_warning (sys.flags attributo):   sys — System-specific parameters and functions.
                                                             (line  568)
* bytes-like object:                     Glossary.           (line  230)
* bytes;formattazione:                   Formattazione Bytes stile printf.
                                                             (line    6)
* bytes;interpolazione:                  Formattazione Bytes stile printf.
                                                             (line    6)
* bytes;metodi:                          Operazioni su Bytes e Bytearray.
                                                             (line    6)
* bytes;str (classe incorporata):        Tipo Sequenza di Testo — str.
                                                             (line   68)
* BytesFeedParser (classe in email.parser): FeedParser API.  (line   28)
* BytesGenerator (classe in email.generator): email generator Generating MIME documents.
                                                             (line   42)
* BytesHeaderParser (classe in email.parser): Parser API.    (line   68)
* BytesIO (classe in io):                Buffered Streams.   (line    9)
* BytesParser (classe in email.parser):  Parser API.         (line   18)
* ByteString (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   68)
* ByteString (classe in typing):         Aliases to container ABCs in collections abc.
                                                             (line   14)
* byteswap() (array.array metodo):       array — Efficient arrays of numeric values.
                                                             (line  146)
* BytesWarning:                          Warnings.           (line   80)
* BZ2Compressor (classe in bz2):         Incremental de compression.
                                                             (line    6)
* BZ2Decompressor (classe in bz2):       Incremental de compression.
                                                             (line   33)
* BZ2File (classe in bz2):               De compression of files.
                                                             (line   40)
* C:                                     Formal grammar.     (line   28)
* c_bool (classe in ctypes):             Fundamental data types<2>.
                                                             (line  228)
* c_byte (classe in ctypes):             Fundamental data types<2>.
                                                             (line   45)
* c_char (classe in ctypes):             Fundamental data types<2>.
                                                             (line   51)
* c_char_p (classe in ctypes):           Fundamental data types<2>.
                                                             (line   58)
* C_CONTIGUOUS (inspect.BufferFlags attributo): Buffer flags.
                                                             (line   25)
* c_contiguous (memoryview attributo):   Memory Views.       (line  516)
* c_double (classe in ctypes):           Fundamental data types<2>.
                                                             (line   65)
* c_double_complex (classe in ctypes):   Fundamental data types<2>.
                                                             (line   81)
* c_float (classe in ctypes):            Fundamental data types<2>.
                                                             (line   76)
* c_float_complex (classe in ctypes):    Fundamental data types<2>.
                                                             (line   88)
* c_int (classe in ctypes):              Fundamental data types<2>.
                                                             (line  102)
* c_int16 (classe in ctypes):            Fundamental data types<2>.
                                                             (line  114)
* c_int32 (classe in ctypes):            Fundamental data types<2>.
                                                             (line  119)
* c_int64 (classe in ctypes):            Fundamental data types<2>.
                                                             (line  124)
* c_int8 (classe in ctypes):             Fundamental data types<2>.
                                                             (line  109)
* c_long (classe in ctypes):             Fundamental data types<2>.
                                                             (line  129)
* c_longdouble (classe in ctypes):       Fundamental data types<2>.
                                                             (line   70)
* c_longdouble_complex (classe in ctypes): Fundamental data types<2>.
                                                             (line   95)
* c_longlong (classe in ctypes):         Fundamental data types<2>.
                                                             (line  134)
* C_RAISE (monitoring event):            Events.             (line   25)
* C_RETURN (monitoring event):           Events.             (line   30)
* c_short (classe in ctypes):            Fundamental data types<2>.
                                                             (line  140)
* c_size_t (classe in ctypes):           Fundamental data types<2>.
                                                             (line  145)
* c_ssize_t (classe in ctypes):          Fundamental data types<2>.
                                                             (line  149)
* c_time_t (classe in ctypes):           Fundamental data types<2>.
                                                             (line  155)
* c_ubyte (classe in ctypes):            Fundamental data types<2>.
                                                             (line  161)
* c_uint (classe in ctypes):             Fundamental data types<2>.
                                                             (line  167)
* c_uint16 (classe in ctypes):           Fundamental data types<2>.
                                                             (line  179)
* c_uint32 (classe in ctypes):           Fundamental data types<2>.
                                                             (line  184)
* c_uint64 (classe in ctypes):           Fundamental data types<2>.
                                                             (line  189)
* c_uint8 (classe in ctypes):            Fundamental data types<2>.
                                                             (line  174)
* c_ulong (classe in ctypes):            Fundamental data types<2>.
                                                             (line  194)
* c_ulonglong (classe in ctypes):        Fundamental data types<2>.
                                                             (line  199)
* c_ushort (classe in ctypes):           Fundamental data types<2>.
                                                             (line  205)
* c_void_p (classe in ctypes):           Fundamental data types<2>.
                                                             (line  210)
* c_wchar (classe in ctypes):            Fundamental data types<2>.
                                                             (line  215)
* c_wchar_p (classe in ctypes):          Fundamental data types<2>.
                                                             (line  222)
* C-contiguous:                          shape strides suboffsets.
                                                             (line   34)
* C-contiguous <1>:                      Glossary.           (line  390)
* C;language:                            The standard type hierarchy.
                                                             (line    6)
* C;language <1>:                        numbers Real float. (line    6)
* C;language <2>:                        Built-in functions. (line    6)
* C;language <3>:                        Comparisons.        (line    6)
* C;linguaggio:                          Tipi Numerici — int float complex.
                                                             (line    6)
* C;structures:                          struct — Interpret bytes as packed binary data.
                                                             (line    8)
* C14NWriterTarget (classe in xml.etree.ElementTree): TreeBuilder Objects.
                                                             (line   94)
* CACHE (opcode):                        Python Bytecode Instructions.
                                                             (line  191)
* cache_clear() (functools.lru_cache metodo): functools — Higher-order functions and operations on callable objects.
                                                             (line  202)
* cache_from_source() (nel modulo importlib.util): importlib util – Utility code for importers.
                                                             (line   21)
* cache_info() (functools.lru_cache metodo): functools — Higher-order functions and operations on callable objects.
                                                             (line  197)
* cache() (nel modulo functools):        functools — Higher-order functions and operations on callable objects.
                                                             (line   16)
* cached (importlib.machinery.ModuleSpec attributo): importlib machinery – Importers and path hooks.
                                                             (line  423)
* cached_property() (nel modulo functools): functools — Higher-order functions and operations on callable objects.
                                                             (line   49)
* CacheFTPHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  485)
* calcobjsize() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  456)
* calcsize() (nel modulo struct):        Functions and Exceptions.
                                                             (line   55)
* calcvobjsize() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  462)
* Calendar (classe in calendar):         calendar — General calendar-related functions.
                                                             (line   27)
* calendar command line option; -c:      Command-line usage. (line  120)
* calendar command line option; -css:    Command-line usage. (line  120)
* calendar command line option; -e:      Command-line usage. (line   66)
* calendar command line option; -encoding: Command-line usage.
                                                             (line   66)
* calendar command line option; -f:      Command-line usage. (line   75)
* calendar command line option; -first-weekday: Command-line usage.
                                                             (line   75)
* calendar command line option; -h:      Command-line usage. (line   57)
* calendar command line option; -help:   Command-line usage. (line   57)
* calendar command line option; -L:      Command-line usage. (line   61)
* calendar command line option; -l:      Command-line usage. (line  100)
* calendar command line option; -lines:  Command-line usage. (line  100)
* calendar command line option; -locale: Command-line usage. (line   61)
* calendar command line option; -m:      Command-line usage. (line  111)
* calendar command line option; -months: Command-line usage. (line  111)
* calendar command line option; -s:      Command-line usage. (line  106)
* calendar command line option; -spacing: Command-line usage.
                                                             (line  106)
* calendar command line option; -t:      Command-line usage. (line   71)
* calendar command line option; -type:   Command-line usage. (line   71)
* calendar command line option; -w:      Command-line usage. (line   94)
* calendar command line option; -width:  Command-line usage. (line   94)
* calendar command line option; month:   Command-line usage. (line   86)
* calendar command line option; year:    Command-line usage. (line   82)
* calendar() (nel modulo calendar):      calendar — General calendar-related functions.
                                                             (line  412)
* call:                                  Slicings.           (line   39)
* Call (classe in ast):                  Expressions<2>.     (line  121)
* CALL (monitoring event):               Events.             (line   21)
* CALL (opcode):                         Python Bytecode Instructions.
                                                             (line 1077)
* call_annotate_function() (nel modulo annotationlib): Functions<11>.
                                                             (line   26)
* call_args (unittest.mock.Mock attributo): The Mock Class.  (line  438)
* call_args_list (unittest.mock.Mock attributo): The Mock Class.
                                                             (line  483)
* call_at() (asyncio.loop metodo):       Scheduling delayed callbacks.
                                                             (line   41)
* call_count (unittest.mock.Mock attributo): The Mock Class. (line  331)
* call_evaluate_function() (nel modulo annotationlib): Functions<11>.
                                                             (line   55)
* call_exception_handler() (asyncio.loop metodo): Error Handling API.
                                                             (line   45)
* CALL_FUNCTION_EX (opcode):             Python Bytecode Instructions.
                                                             (line 1129)
* call_in_thread() (concurrent.interpreters.Interpreter metodo): Interpreter objects.
                                                             (line   53)
* CALL_INTRINSIC_1 (opcode):             Python Bytecode Instructions.
                                                             (line 1341)
* CALL_INTRINSIC_2 (opcode):             Python Bytecode Instructions.
                                                             (line 1402)
* CALL_KW (opcode):                      Python Bytecode Instructions.
                                                             (line 1102)
* call_later() (asyncio.loop metodo):    Scheduling delayed callbacks.
                                                             (line   10)
* call_list() (unittest.mock.call metodo): call.             (line   20)
* call_soon_threadsafe() (asyncio.loop metodo): Scheduling callbacks.
                                                             (line   24)
* call_soon() (asyncio.loop metodo):     Scheduling callbacks.
                                                             (line    6)
* call_tracing() (nel modulo sys):       sys — System-specific parameters and functions.
                                                             (line  165)
* call;instance:                         Emulating callable objects.
                                                             (line    8)
* call() (concurrent.interpreters.Interpreter metodo): Interpreter objects.
                                                             (line   48)
* call() (nel modulo operator):          operator — Standard operators as functions.
                                                             (line  233)
* call() (nel modulo subprocess):        Older high-level API.
                                                             (line   10)
* call() (nel modulo unittest.mock):     call.               (line    6)
* callable:                              Glossary.           (line  264)
* Callable (classe in collections.abc):  Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   19)
* Callable (nel modulo typing):          Aliases to other ABCs in collections abc.
                                                             (line   22)
* CallableProxyType (nel modulo weakref): weakref — Weak references.
                                                             (line  340)
* callback:                              Glossary.           (line  275)
* callback (optparse.Option attributo):  Option attributes.  (line   68)
* callback_args (optparse.Option attributo): Option attributes.
                                                             (line   74)
* callback_kwargs (optparse.Option attributo): Option attributes.
                                                             (line   74)
* callback() (contextlib.ExitStack metodo): Utilities.       (line  582)
* callbacks (nel modulo gc):             gc — Garbage Collector interface.
                                                             (line  290)
* called (unittest.mock.Mock attributo): The Mock Class.     (line  319)
* CalledProcessError:                    Using the subprocess Module.
                                                             (line  206)
* calloc (C function):                   Overview<4>.        (line   33)
* CAN (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   97)
* CAN_BCM (nel modulo socket):           Constants<8>.       (line  154)
* can_change_color() (nel modulo curses): Functions<5>.      (line   45)
* can_fetch() (urllib.robotparser.RobotFileParser metodo): urllib robotparser — Parser for robots txt.
                                                             (line   33)
* CAN_ISOTP (nel modulo socket):         Constants<8>.       (line  193)
* CAN_J1939 (nel modulo socket):         Constants<8>.       (line  202)
* CAN_RAW_FD_FRAMES (nel modulo socket): Constants<8>.       (line  169)
* CAN_RAW_JOIN_FILTERS (nel modulo socket): Constants<8>.    (line  182)
* can_symlink() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   78)
* can_write_eof() (asyncio.StreamWriter metodo): StreamWriter.
                                                             (line   50)
* can_write_eof() (asyncio.WriteTransport metodo): Write-only Transports.
                                                             (line   14)
* can_xattr() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   82)
* CANCEL (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  155)
* cancel_command() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line   82)
* cancel_dump_traceback_later() (nel modulo faulthandler): Dumping the tracebacks after a timeout.
                                                             (line   29)
* cancel_join_thread() (multiprocessing.Queue metodo): Pipes and Queues.
                                                             (line  202)
* cancel() (asyncio.Future metodo):      Future Object.      (line  113)
* cancel() (asyncio.Handle metodo):      Callback Handles.   (line   18)
* cancel() (asyncio.Task metodo):        Task Object.        (line  199)
* cancel() (concurrent.futures.Future metodo): Future Objects.
                                                             (line   16)
* cancel() (sched.scheduler metodo):     Scheduler Objects.  (line   41)
* cancel() (threading.Timer metodo):     Timer objects.      (line   36)
* cancel() (tkinter.dnd.DndHandler metodo): tkinter dnd — Drag and drop support.
                                                             (line   48)
* cancelled() (asyncio.Future metodo):   Future Object.      (line   71)
* cancelled() (asyncio.Handle metodo):   Callback Handles.   (line   23)
* cancelled() (asyncio.Task metodo):     Task Object.        (line  263)
* cancelled() (concurrent.futures.Future metodo): Future Objects.
                                                             (line   23)
* CancelledError:                        Exception classes.  (line    6)
* CancelledError <1>:                    Exceptions<15>.     (line   18)
* cancelling() (asyncio.Task metodo):    Task Object.        (line  320)
* CannotSendHeader:                      http client — HTTP protocol client.
                                                             (line  170)
* CannotSendRequest:                     http client — HTTP protocol client.
                                                             (line  166)
* canonic() (bdb.Bdb metodo):            bdb — Debugger framework.
                                                             (line  161)
* canonical() (decimal.Context metodo):  Context objects.    (line  278)
* canonical() (decimal.Decimal metodo):  Decimal objects.    (line  143)
* canonicalize() (nel modulo xml.etree.ElementTree): Functions<8>.
                                                             (line    6)
* capa() (poplib.POP3 metodo):           POP3 Objects.       (line   24)
* capitalize() (bytearray metodo):       Operazioni su Bytes e Bytearray.
                                                             (line  484)
* capitalize() (bytes metodo):           Operazioni su Bytes e Bytearray.
                                                             (line  484)
* capitalize() (str metodo):             Metodi per le Stringhe.
                                                             (line   23)
* capitals (decimal.Context attributo):  Context objects.    (line  155)
* CapsuleType (classe in types):         Standard Interpreter Types.
                                                             (line  297)
* capture_call_graph() (nel modulo asyncio): Call Graph Introspection.
                                                             (line   77)
* captured_stderr() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  350)
* captured_stdin() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  350)
* captured_stdout() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  350)
* captureWarnings() (nel modulo logging): Integration with the warnings module.
                                                             (line    9)
* capwords() (nel modulo string):        Helper functions.   (line    6)
* case block:                            Irrefutable Case Blocks.
                                                             (line    6)
* casefold() (str metodo):               Metodi per le Stringhe.
                                                             (line   33)
* cast() (memoryview metodo):            Memory Views.       (line  293)
* cast() (nel modulo ctypes):            Utility functions.  (line   50)
* cast() (nel modulo typing):            Functions and decorators.
                                                             (line    6)
* catch_threading_exception() (nel modulo test.support.threading_helper): test support threading_helper — Utilities for threading tests.
                                                             (line   47)
* catch_unraisable_exception() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  632)
* catch_warnings (classe in warnings):   Available Context Managers.
                                                             (line    6)
* category() (nel modulo unicodedata):   unicodedata — Unicode Database.
                                                             (line   80)
* cbreak() (nel modulo curses):          Functions<5>.       (line   50)
* cbrt() (nel modulo math):              Power exponential and logarithmic functions.
                                                             (line    6)
* CC:                                    New Improved and Deprecated Modules<4>.
                                                             (line   58)
* ccc() (ftplib.FTP_TLS metodo):         FTP_TLS objects.    (line   98)
* cdf() (statistics.NormalDist metodo):  NormalDist objects. (line   86)
* CDLL (classe in ctypes):               Loading shared libraries.
                                                             (line    9)
* ceil() (nel modulo math):              Tipi Numerici — int float complex.
                                                             (line  117)
* ceil() (nel modulo math) <1>:          Floating point arithmetic.
                                                             (line    6)
* CellType (nel modulo types):           Standard Interpreter Types.
                                                             (line   70)
* center() (bytearray metodo):           Operazioni su Bytes e Bytearray.
                                                             (line  301)
* center() (bytes metodo):               Operazioni su Bytes e Bytearray.
                                                             (line  301)
* center() (str metodo):                 Metodi per le Stringhe.
                                                             (line   56)
* CERT_NONE (nel modulo ssl):            Constants<9>.       (line   11)
* CERT_OPTIONAL (nel modulo ssl):        Constants<9>.       (line   24)
* CERT_REQUIRED (nel modulo ssl):        Constants<9>.       (line   40)
* cert_store_stats() (ssl.SSLContext metodo): SSL Contexts.  (line   88)
* cert_time_to_seconds() (nel modulo ssl): Certificate handling.
                                                             (line    6)
* CertificateError:                      Exceptions<18>.     (line   94)
* certificates:                          SSL Contexts.       (line  762)
* CField (classe in ctypes):             Structured data types.
                                                             (line  214)
* CFLAGS:                                New Improved and Deprecated Modules<4>.
                                                             (line   59)
* CFLAGS <1>:                            Performance options.
                                                             (line   28)
* CFLAGS <2>:                            Compiler flags.     (line   26)
* CFLAGS <3>:                            Compiler flags.     (line   28)
* CFLAGS <4>:                            Compiler flags.     (line   32)
* CFLAGS <5>:                            Compiler flags.     (line   54)
* CFLAGS <6>:                            Linker flags.       (line   18)
* CFLAGS_NODIST:                         Compiler flags.     (line   24)
* CFLAGS_NODIST <1>:                     Compiler flags.     (line   61)
* CFLAGS_NODIST <2>:                     Linker flags.       (line   26)
* cfmakecbreak() (nel modulo tty):       tty — Terminal control functions.
                                                             (line   28)
* cfmakeraw() (nel modulo tty):          tty — Terminal control functions.
                                                             (line   20)
* CFUNCTYPE() (nel modulo ctypes):       Function prototypes.
                                                             (line   15)
* cget() (tkinter.font.Font metodo):     tkinter font — Tkinter font wrapper.
                                                             (line   51)
* cgi_directories (http.server.CGIHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  514)
* CGIHandler (classe in wsgiref.handlers): wsgiref handlers – server/gateway base classes.
                                                             (line   11)
* CGIHTTPRequestHandler (classe in http.server): http server — HTTP servers.
                                                             (line  488)
* CGIXMLRPCRequestHandler (classe in xmlrpc.server): xmlrpc server — Basic XML-RPC servers.
                                                             (line   51)
* chain_log (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line   73)
* chain() (nel modulo itertools):        Itertool Functions. (line  107)
* chaining;comparisons:                  Comparisons.        (line   19)
* ChainMap (classe in collections):      ChainMap objects.   (line   16)
* ChainMap (classe in typing):           Aliases to types in collections.
                                                             (line   28)
* change_cwd() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   86)
* CHANNEL_BINDING_TYPES (nel modulo ssl): Constants<9>.      (line  477)
* CHAR_MAX (nel modulo locale):          locale — Internationalization services.
                                                             (line  593)
* character:                             Immutable sequences.
                                                             (line   15)
* character <1>:                         Subscriptions.      (line   58)
* character <2>:                         unicodedata — Unicode Database.
                                                             (line    6)
* CharacterDataHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  328)
* characters_written (BlockingIOError attributo): OS exceptions.
                                                             (line   19)
* characters() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line  127)
* charmap_build() (nel modulo codecs):   codecs — Codec registry and base classes.
                                                             (line   45)
* Charset (classe in email.charset):     email charset Representing character sets.
                                                             (line   24)
* charset() (gettext.NullTranslations metodo): The NullTranslations class.
                                                             (line   68)
* chdir() (nel modulo contextlib):       Utilities.          (line  364)
* chdir() (nel modulo os):               Files and Directories.
                                                             (line  116)
* check (lzma.LZMADecompressor attributo): Compressing and decompressing data in memory<2>.
                                                             (line  159)
* check__all__() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  712)
* check_call() (nel modulo subprocess):  Older high-level API.
                                                             (line   43)
* check_disallow_instantiation() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  766)
* CHECK_EG_MATCH (opcode):               Python Bytecode Instructions.
                                                             (line  470)
* CHECK_EXC_MATCH (opcode):              Python Bytecode Instructions.
                                                             (line  462)
* check_free_after_iterating() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  700)
* check_hostname (ssl.SSLContext attributo): SSL Contexts.   (line  493)
* check_impl_detail() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  314)
* check_no_resource_warning() (nel modulo test.support.warnings_helper): test support warnings_helper — Utilities for warnings tests.
                                                             (line   25)
* check_output() (doctest.OutputChecker metodo): OutputChecker objects.
                                                             (line   17)
* check_output() (nel modulo subprocess): Older high-level API.
                                                             (line   80)
* check_returncode() (subprocess.CompletedProcess metodo): Using the subprocess Module.
                                                             (line  135)
* check_syntax_error() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  606)
* check_syntax_warning() (nel modulo test.support.warnings_helper): test support warnings_helper — Utilities for warnings tests.
                                                             (line   32)
* check_unused_args() (string.Formatter metodo): Custom String Formatting.
                                                             (line   95)
* check_warnings() (nel modulo test.support.warnings_helper): test support warnings_helper — Utilities for warnings tests.
                                                             (line   48)
* check() (imaplib.IMAP4 metodo):        IMAP4 Objects.      (line   58)
* check() (nel modulo tabnanny):         tabnanny — Detection of ambiguous indentation.
                                                             (line   17)
* checkcache() (nel modulo linecache):   linecache — Random access to text lines.
                                                             (line   49)
* CHECKED_HASH (py_compile.PycInvalidationMode attributo): py_compile — Compile Python source files.
                                                             (line  109)
* checkfuncname() (nel modulo bdb):      bdb — Debugger framework.
                                                             (line  503)
* checksizeof() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  468)
* checksum_flag (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  205)
* checksum;Cyclic Redundancy Check:      zlib — Compression compatible with gzip.
                                                             (line  123)
* chflags() (nel modulo os):             Files and Directories.
                                                             (line  135)
* chgat() (curses.window metodo):        Window Objects.     (line  138)
* childNodes (xml.dom.Node attributo):   Node Objects.       (line   49)
* ChildProcessError:                     OS exceptions.      (line   25)
* children (pyclbr.Class attributo):     Class Objects.      (line   35)
* children (pyclbr.Function attributo):  Function Objects.   (line   34)
* children (tkinter.Tk attributo):       Tkinter Modules.    (line   88)
* chksum (tarfile.TarInfo attributo):    TarInfo Objects.    (line  137)
* chmod() (nel modulo os):               Files and Directories.
                                                             (line  176)
* chmod() (pathlib.Path metodo):         Permissions and ownership.
                                                             (line   38)
* choice() (nel modulo random):          Functions for sequences.
                                                             (line    6)
* choice() (nel modulo secrets):         Random numbers.     (line   15)
* choices (optparse.Option attributo):   Option attributes.  (line   63)
* choices() (nel modulo random):         Functions for sequences.
                                                             (line   11)
* Chooser (classe in tkinter.colorchooser): tkinter colorchooser — Color choosing dialog.
                                                             (line   15)
* chown() (nel modulo os):               Files and Directories.
                                                             (line  246)
* chown() (nel modulo shutil):           Directory and files operations.
                                                             (line  419)
* chroot() (nel modulo os):              Files and Directories.
                                                             (line  274)
* CHRTYPE (nel modulo tarfile):          tarfile — Read and write tar archive files.
                                                             (line  337)
* ciclo;su sequenza mutabile:            Operazioni Comuni sulle Sequenze.
                                                             (line   69)
* cipher() (ssl.SSLSocket metodo):       SSL Sockets.        (line  233)
* circle() (nel modulo turtle):          Turtle motion.      (line  211)
* CIRCUMFLEX (nel modulo token):         token — Constants used with Python parse trees.
                                                             (line  287)
* CIRCUMFLEXEQUAL (nel modulo token):    token — Constants used with Python parse trees.
                                                             (line  320)
* clamp (decimal.Context attributo):     Context objects.    (line  161)
* Clamped (classe in decimal):           Signals.            (line   20)
* class:                                 Glossary.           (line  280)
* Class (classe in pyclbr):              Class Objects.      (line    6)
* Class (classe in symtable):            Examining Symbol Tables.
                                                             (line  150)
* CLASS (symtable.SymbolTableType attributo): Examining Symbol Tables.
                                                             (line   19)
* class instance;attribute:              Class instances.    (line    6)
* class instance;attribute;assignment:   Class instances.    (line   21)
* class instance;call:                   Calls.              (line  153)
* class object;call:                     Custom classes.     (line   19)
* class object;call <1>:                 Custom classes.     (line   31)
* class object;call <2>:                 Calls.              (line  149)
* class variable:                        Glossary.           (line  286)
* class;attribute:                       Custom classes.     (line   19)
* class;attribute;assignment:            Custom classes.     (line   28)
* class;body:                            Executing the class body.
                                                             (line    6)
* class;constructor:                     Basic customization.
                                                             (line   39)
* class;definition:                      The return statement.
                                                             (line    6)
* class;definition <1>:                  Class definitions.  (line    6)
* class;instance:                        Class instances.    (line    6)
* class;name:                            Class definitions.  (line    6)
* ClassDef (classe in ast):              Function and class definitions.
                                                             (line  169)
* ClassMethodDescriptorType (nel modulo types): Standard Interpreter Types.
                                                             (line  116)
* ClassVar (nel modulo typing):          Special forms.      (line  200)
* clause:                                Compound statements.
                                                             (line   18)
* CLD_CONTINUED (nel modulo os):         Process Management. (line 1060)
* CLD_DUMPED (nel modulo os):            Process Management. (line 1060)
* CLD_EXITED (nel modulo os):            Process Management. (line 1060)
* CLD_KILLED (nel modulo os):            Process Management. (line 1060)
* CLD_STOPPED (nel modulo os):           Process Management. (line 1060)
* CLD_TRAPPED (nel modulo os):           Process Management. (line 1060)
* clean() (mailbox.Maildir metodo):      Maildir objects.    (line   86)
* cleandoc() (nel modulo inspect):       Retrieving source code.
                                                             (line   71)
* CleanImport (classe in test.support.import_helper): test support import_helper — Utilities for import tests.
                                                             (line   87)
* cleanup functions:                     Process Control.    (line   34)
* CLEANUP_THROW (opcode):                Python Bytecode Instructions.
                                                             (line  360)
* cleanup() (tempfile.TemporaryDirectory metodo): tempfile — Generate temporary files and directories.
                                                             (line  202)
* clear (pdb command):                   Debugger commands.  (line  135)
* Clear Breakpoint:                      Help menu Shell and Editor.
                                                             (line   30)
* clear_all_breaks() (bdb.Bdb metodo):   bdb — Debugger framework.
                                                             (line  395)
* clear_all_file_breaks() (bdb.Bdb metodo): bdb — Debugger framework.
                                                             (line  390)
* clear_bpbynumber() (bdb.Bdb metodo):   bdb — Debugger framework.
                                                             (line  384)
* clear_break() (bdb.Bdb metodo):        bdb — Debugger framework.
                                                             (line  379)
* clear_cache() (nel modulo filecmp):    filecmp — File and Directory Comparisons.
                                                             (line   56)
* clear_cache() (zoneinfo.ZoneInfo metodo della classe): The ZoneInfo class.
                                                             (line   61)
* clear_content() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  672)
* clear_flags() (decimal.Context metodo): Context objects.   (line  192)
* clear_frames() (nel modulo traceback): Module-Level Functions<2>.
                                                             (line  177)
* clear_history() (nel modulo readline): History list.       (line    8)
* clear_memo() (pickle.Pickler metodo):  Module Interface.   (line  237)
* clear_overloads() (nel modulo typing): Functions and decorators.
                                                             (line  303)
* clear_session_cookies() (http.cookiejar.CookieJar metodo): CookieJar and FileCookieJar Objects.
                                                             (line   90)
* clear_tool_id() (nel modulo sys.monitoring): Registering and using tools.
                                                             (line   13)
* clear_traces() (nel modulo tracemalloc): Functions<10>.    (line    6)
* clear_traps() (decimal.Context metodo): Context objects.   (line  196)
* clear() (array.array metodo):          array — Efficient arrays of numeric values.
                                                             (line  225)
* clear() (asyncio.Event metodo):        Event.              (line   58)
* clear() (collections.deque metodo):    deque objects.      (line   43)
* clear() (curses.window metodo):        Window Objects.     (line  154)
* clear() (dict metodo):                 Tipi di Mapping — dict.
                                                             (line  166)
* clear() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  668)
* clear() (frame metodo):                Frame object methods.
                                                             (line    8)
* clear() (http.cookiejar.CookieJar metodo): CookieJar and FileCookieJar Objects.
                                                             (line   78)
* clear() (mailbox.Mailbox metodo):      Mailbox objects.    (line  213)
* clear() (nel modulo turtle):           More drawing control.
                                                             (line   23)
* clear() (sequence metodo):             Tipi di Sequenza Mutabili.
                                                             (line   76)
* clear() (set metodo):                  Tipi di Insiemi — set frozenset.
                                                             (line  225)
* clear() (threading.Event metodo):      Event objects.      (line   37)
* clear() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line   58)
* clearcache() (nel modulo linecache):   linecache — Random access to text lines.
                                                             (line   44)
* clearok() (curses.window metodo):      Window Objects.     (line  159)
* clearscreen() (nel modulo turtle):     Window control.     (line   73)
* clearstamp() (nel modulo turtle):      Turtle motion.      (line  290)
* clearstamps() (nel modulo turtle):     Turtle motion.      (line  309)
* client_address (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  118)
* client_address (socketserver.BaseRequestHandler attributo): Request Handler Objects.
                                                             (line   47)
* Client() (nel modulo multiprocessing.connection): Listeners and Clients.
                                                             (line   34)
* CLOCK_BOOTTIME (nel modulo time):      Clock ID Constants. (line    9)
* clock_getres() (nel modulo time):      Functions<4>.       (line   40)
* clock_gettime_ns() (nel modulo time):  Functions<4>.       (line   63)
* clock_gettime() (nel modulo time):     Functions<4>.       (line   50)
* CLOCK_HIGHRES (nel modulo time):       Clock ID Constants. (line   23)
* CLOCK_MONOTONIC (nel modulo time):     Clock ID Constants. (line   34)
* CLOCK_MONOTONIC_RAW (nel modulo time): Clock ID Constants. (line   43)
* CLOCK_MONOTONIC_RAW_APPROX (nel modulo time): Clock ID Constants.
                                                             (line   52)
* CLOCK_PROCESS_CPUTIME_ID (nel modulo time): Clock ID Constants.
                                                             (line   61)
* CLOCK_PROF (nel modulo time):          Clock ID Constants. (line   69)
* CLOCK_REALTIME (nel modulo time):      Clock ID Constants. (line  129)
* clock_seq (uuid.UUID attributo):       uuid — UUID objects according to RFC 9562.
                                                             (line  138)
* clock_seq_hi_variant (uuid.UUID attributo): uuid — UUID objects according to RFC 9562.
                                                             (line  119)
* clock_seq_low (uuid.UUID attributo):   uuid — UUID objects according to RFC 9562.
                                                             (line  123)
* clock_settime_ns() (nel modulo time):  Functions<4>.       (line   84)
* clock_settime() (nel modulo time):     Functions<4>.       (line   72)
* CLOCK_TAI (nel modulo time):           Clock ID Constants. (line   77)
* CLOCK_THREAD_CPUTIME_ID (nel modulo time): Clock ID Constants.
                                                             (line   89)
* CLOCK_UPTIME (nel modulo time):        Clock ID Constants. (line   97)
* CLOCK_UPTIME_RAW (nel modulo time):    Clock ID Constants. (line  107)
* CLOCK_UPTIME_RAW_APPROX (nel modulo time): Clock ID Constants.
                                                             (line  117)
* CLONE_FILES (nel modulo os):           Process Parameters. (line  654)
* CLONE_FS (nel modulo os):              Process Parameters. (line  654)
* CLONE_NEWCGROUP (nel modulo os):       Process Parameters. (line  654)
* CLONE_NEWIPC (nel modulo os):          Process Parameters. (line  654)
* CLONE_NEWNET (nel modulo os):          Process Parameters. (line  654)
* CLONE_NEWNS (nel modulo os):           Process Parameters. (line  654)
* CLONE_NEWPID (nel modulo os):          Process Parameters. (line  654)
* CLONE_NEWTIME (nel modulo os):         Process Parameters. (line  654)
* CLONE_NEWUSER (nel modulo os):         Process Parameters. (line  654)
* CLONE_NEWUTS (nel modulo os):          Process Parameters. (line  654)
* CLONE_SIGHAND (nel modulo os):         Process Parameters. (line  654)
* CLONE_SYSVSEM (nel modulo os):         Process Parameters. (line  654)
* CLONE_THREAD (nel modulo os):          Process Parameters. (line  654)
* CLONE_VM (nel modulo os):              Process Parameters. (line  654)
* clone() (email.generator.BytesGenerator metodo): email generator Generating MIME documents.
                                                             (line  112)
* clone() (email.generator.Generator metodo): email generator Generating MIME documents.
                                                             (line  209)
* clone() (email.policy.Policy metodo):  email policy Policy Objects.
                                                             (line  223)
* clone() (nel modulo turtle):           Special Turtle methods.
                                                             (line   44)
* cloneNode() (xml.dom.Node metodo):     Node Objects.       (line  147)
* close (in module os):                  Sub-interpreter support.
                                                             (line  198)
* close_clients() (asyncio.Server metodo): Server Objects.   (line   44)
* close_connection (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  127)
* close() (asyncio.BaseTransport metodo): Base Transport.    (line    6)
* close() (asyncio.loop metodo):         Running and stopping the loop.
                                                             (line   43)
* close() (asyncio.Runner metodo):       Runner context manager.
                                                             (line   57)
* close() (asyncio.Server metodo):       Server Objects.     (line   32)
* close() (asyncio.StreamWriter metodo): StreamWriter.       (line   40)
* close() (asyncio.SubprocessTransport metodo): Subprocess Transports.
                                                             (line   59)
* close() (concurrent.interpreters.Interpreter metodo): Interpreter objects.
                                                             (line   31)
* close() (contextlib.ExitStack metodo): Utilities.          (line  614)
* close() (coroutine metodo):            Coroutine Objects.  (line   50)
* close() (dbm.dumb.dumbdbm metodo):     dbm dumb — Portable DBM implementation.
                                                             (line   81)
* close() (dbm.gnu.gdbm metodo):         dbm gnu — GNU database manager.
                                                             (line   94)
* close() (dbm.ndbm.ndbm metodo):        dbm ndbm — New Database Manager.
                                                             (line   80)
* close() (dbm.sqlite3.sqlite3 metodo):  dbm sqlite3 — SQLite backend for dbm.
                                                             (line   54)
* close() (email.parser.BytesFeedParser metodo): FeedParser API.
                                                             (line   65)
* close() (ftplib.FTP metodo):           FTP objects.        (line  370)
* close() (generator metodo):            Generator-iterator methods.
                                                             (line   65)
* close() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line   15)
* close() (http.client.HTTPConnection metodo): HTTPConnection Objects.
                                                             (line  158)
* close() (imaplib.IMAP4 metodo):        IMAP4 Objects.      (line   62)
* close() (io.IOBase metodo):            I/O Base Classes.   (line   48)
* close() (logging.FileHandler metodo):  FileHandler.        (line   27)
* close() (logging.Handler metodo):      Handler Objects.    (line   74)
* close() (logging.handlers.MemoryHandler metodo): MemoryHandler.
                                                             (line   57)
* close() (logging.handlers.NTEventLogHandler metodo): NTEventLogHandler.
                                                             (line   29)
* close() (logging.handlers.SocketHandler metodo): SocketHandler.
                                                             (line   20)
* close() (logging.handlers.SysLogHandler metodo): SysLogHandler.
                                                             (line   52)
* close() (mailbox.Mailbox metodo):      Mailbox objects.    (line  270)
* close() (mailbox.Maildir metodo):      Maildir objects.    (line  215)
* close() (mailbox.MH metodo):           MH objects.         (line  107)
* close() (mmap.mmap metodo):            mmap — Memory-mapped file support.
                                                             (line  183)
* close() (multiprocessing.connection.Connection metodo): Connection Objects.
                                                             (line   35)
* close() (multiprocessing.connection.Listener metodo): Listeners and Clients.
                                                             (line   91)
* close() (multiprocessing.pool.Pool metodo): Process Pools. (line  176)
* close() (multiprocessing.Process metodo): Process and exceptions.
                                                             (line  250)
* close() (multiprocessing.Queue metodo): Pipes and Queues.  (line  178)
* close() (multiprocessing.shared_memory.SharedMemory metodo): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line   93)
* close() (multiprocessing.SimpleQueue metodo): Pipes and Queues.
                                                             (line  232)
* close() (nel modulo fileinput):        fileinput — Iterate over lines from multiple input streams.
                                                             (line  132)
* close() (nel modulo os):               File Descriptor Operations.
                                                             (line   21)
* close() (nel modulo socket):           Other functions<2>. (line    9)
* close() (os.scandir metodo):           Files and Directories.
                                                             (line  880)
* close() (select.devpoll metodo):       /dev/poll Polling Objects.
                                                             (line   12)
* close() (select.epoll metodo):         Edge and Level Trigger Polling epoll Objects.
                                                             (line   71)
* close() (select.kqueue metodo):        Kqueue Objects.     (line    6)
* close() (selectors.BaseSelector metodo): Classes<3>.       (line  137)
* close() (shelve.Shelf metodo):         shelve — Python object persistence.
                                                             (line   77)
* close() (socket.socket metodo):        Socket Objects.     (line   42)
* close() (sqlite3.Blob metodo):         Blob objects.       (line   37)
* close() (sqlite3.Connection metodo):   Connection objects. (line   88)
* close() (sqlite3.Cursor metodo):       Cursor objects.     (line  157)
* close() (tarfile.TarFile metodo):      TarFile Objects.    (line  326)
* close() (urllib.request.BaseHandler metodo): BaseHandler Objects.
                                                             (line   14)
* close() (wave.Wave_read metodo):       Wave_read Objects.  (line   13)
* close() (wave.Wave_write metodo):      Wave_write Objects. (line   29)
* Close() (winreg.PyHKEY metodo):        Registry Handle Objects.
                                                             (line   30)
* close() (xml.etree.ElementTree.TreeBuilder metodo): TreeBuilder Objects.
                                                             (line   28)
* close() (xml.etree.ElementTree.XMLParser metodo): XMLParser Objects.
                                                             (line   20)
* close() (xml.etree.ElementTree.XMLPullParser metodo): XMLPullParser Objects.
                                                             (line   41)
* close() (xml.sax.xmlreader.IncrementalParser metodo): IncrementalParser Objects.
                                                             (line   13)
* close() (zipfile.ZipFile metodo):      ZipFile objects.    (line  112)
* CloseBoundaryNotFoundDefect:           email errors Exception and Defect classes.
                                                             (line   85)
* closed (http.client.HTTPResponse attributo): HTTPResponse Objects.
                                                             (line   75)
* closed (io.IOBase attributo):          I/O Base Classes.   (line   58)
* closed (mmap.mmap attributo):          mmap — Memory-mapped file support.
                                                             (line  189)
* closed (select.devpoll attributo):     /dev/poll Polling Objects.
                                                             (line   18)
* closed (select.epoll attributo):       Edge and Level Trigger Polling epoll Objects.
                                                             (line   75)
* closed (select.kqueue attributo):      Kqueue Objects.     (line   10)
* CloseKey() (nel modulo winreg):        Functions<13>.      (line    8)
* closelog() (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line   78)
* closerange() (nel modulo os):          File Descriptor Operations.
                                                             (line   32)
* closing() (nel modulo contextlib):     Utilities.          (line  152)
* closure variable:                      Glossary.           (line  291)
* clrtobot() (curses.window metodo):     Window Objects.     (line  164)
* clrtoeol() (curses.window metodo):     Window Objects.     (line  170)
* Cmd (classe in cmd):                   cmd — Support for line-oriented command interpreters.
                                                             (line   15)
* cmd (subprocess.CalledProcessError attributo): Using the subprocess Module.
                                                             (line  217)
* cmd (subprocess.TimeoutExpired attributo): Using the subprocess Module.
                                                             (line  174)
* cmdloop() (cmd.Cmd metodo):            Cmd Objects.        (line    8)
* cmdqueue (cmd.Cmd attributo):          Cmd Objects.        (line  143)
* cmp_op (nel modulo dis):               Opcode collections. (line   21)
* cmp_to_key() (nel modulo functools):   functools — Higher-order functions and operations on callable objects.
                                                             (line  118)
* cmp() (nel modulo filecmp):            filecmp — File and Directory Comparisons.
                                                             (line   16)
* cmpfiles() (nel modulo filecmp):       filecmp — File and Directory Comparisons.
                                                             (line   36)
* CMSG_LEN() (nel modulo socket):        Other functions<2>. (line  336)
* CMSG_SPACE() (nel modulo socket):      Other functions<2>. (line  353)
* co_argcount (code object attribute):   Code objects.       (line   16)
* co_argcount (codeobject attributo):    Special read-only attributes<2>.
                                                             (line   14)
* CO_ASYNC_GENERATOR (C macro):          Code Object Flags.  (line   48)
* CO_ASYNC_GENERATOR (nel modulo inspect): Code Objects Bit Flags.
                                                             (line   52)
* co_cellvars (code object attribute):   Code objects.       (line   16)
* co_cellvars (codeobject attributo):    Special read-only attributes<2>.
                                                             (line   39)
* co_code (code object attribute):       Code objects.       (line   16)
* co_code (codeobject attributo):        Special read-only attributes<2>.
                                                             (line   54)
* co_consts (code object attribute):     Code objects.       (line   16)
* co_consts (codeobject attributo):      Special read-only attributes<2>.
                                                             (line   58)
* CO_COROUTINE (C macro):                Code Object Flags.  (line   42)
* CO_COROUTINE (nel modulo inspect):     Code Objects Bit Flags.
                                                             (line   35)
* co_filename (code object attribute):   Code objects.       (line   16)
* co_filename (codeobject attributo):    Special read-only attributes<2>.
                                                             (line   66)
* co_firstlineno (code object attribute): Code objects.      (line   16)
* co_firstlineno (codeobject attributo): Special read-only attributes<2>.
                                                             (line   70)
* co_flags (code object attribute):      Code objects.       (line   16)
* co_flags (codeobject attributo):       Special read-only attributes<2>.
                                                             (line   85)
* co_freevars (code object attribute):   Code objects.       (line   16)
* co_freevars (codeobject attributo):    Special read-only attributes<2>.
                                                             (line   45)
* CO_FUTURE_ABSOLUTE_IMPORT (C macro):   Code Object Flags.  (line   60)
* CO_FUTURE_ANNOTATIONS (C macro):       Code Object Flags.  (line   75)
* CO_FUTURE_DIVISION (C macro):          Code Object Flags.  (line   57)
* CO_FUTURE_GENERATOR_STOP (C macro):    Code Object Flags.  (line   72)
* CO_FUTURE_PRINT_FUNCTION (C macro):    Code Object Flags.  (line   66)
* CO_FUTURE_UNICODE_LITERALS (C macro):  Code Object Flags.  (line   69)
* CO_FUTURE_WITH_STATEMENT (C macro):    Code Object Flags.  (line   63)
* CO_GENERATOR (C macro):                Code Object Flags.  (line   39)
* CO_GENERATOR (nel modulo inspect):     Code Objects Bit Flags.
                                                             (line   30)
* CO_HAS_DOCSTRING (C macro):            Code Object Flags.  (line   51)
* CO_HAS_DOCSTRING (nel modulo inspect): Code Objects Bit Flags.
                                                             (line   60)
* CO_ITERABLE_COROUTINE (C macro):       Code Object Flags.  (line   45)
* CO_ITERABLE_COROUTINE (nel modulo inspect): Code Objects Bit Flags.
                                                             (line   43)
* co_kwonlyargcount (code object attribute): Code objects.   (line   16)
* co_kwonlyargcount (codeobject attributo): Special read-only attributes<2>.
                                                             (line   25)
* co_lines() (codeobject metodo):        Methods on code objects.
                                                             (line   43)
* co_lnotab (code object attribute):     Code objects.       (line   16)
* co_lnotab (codeobject attributo):      Special read-only attributes<2>.
                                                             (line   73)
* CO_METHOD (C macro):                   Code Object Flags.  (line   54)
* CO_METHOD (nel modulo inspect):        Code Objects Bit Flags.
                                                             (line   68)
* co_name (code object attribute):       Code objects.       (line   16)
* co_name (codeobject attributo):        Special read-only attributes<2>.
                                                             (line    6)
* co_names (code object attribute):      Code objects.       (line   16)
* co_names (codeobject attributo):       Special read-only attributes<2>.
                                                             (line   62)
* CO_NESTED (C macro):                   Code Object Flags.  (line   36)
* CO_NESTED (nel modulo inspect):        Code Objects Bit Flags.
                                                             (line   26)
* CO_NEWLOCALS (C macro):                Code Object Flags.  (line   27)
* CO_NEWLOCALS (nel modulo inspect):     Code Objects Bit Flags.
                                                             (line   13)
* co_nlocals (code object attribute):    Code objects.       (line   16)
* co_nlocals (codeobject attributo):     Special read-only attributes<2>.
                                                             (line   30)
* CO_OPTIMIZED (C macro):                Code Object Flags.  (line   24)
* CO_OPTIMIZED (nel modulo inspect):     Code Objects Bit Flags.
                                                             (line    9)
* co_positions() (codeobject metodo):    Methods on code objects.
                                                             (line    6)
* co_posonlyargcount (code object attribute): Code objects.  (line   16)
* co_posonlyargcount (codeobject attributo): Special read-only attributes<2>.
                                                             (line   20)
* co_qualname (code object attribute):   Code objects.       (line   16)
* co_qualname (codeobject attributo):    Special read-only attributes<2>.
                                                             (line    9)
* co_stacksize (code object attribute):  Code objects.       (line   16)
* co_stacksize (codeobject attributo):   Special read-only attributes<2>.
                                                             (line   82)
* CO_VARARGS (C macro):                  Code Object Flags.  (line   30)
* CO_VARARGS (nel modulo inspect):       Code Objects Bit Flags.
                                                             (line   18)
* CO_VARKEYWORDS (C macro):              Code Object Flags.  (line   33)
* CO_VARKEYWORDS (nel modulo inspect):   Code Objects Bit Flags.
                                                             (line   22)
* co_varnames (code object attribute):   Code objects.       (line   16)
* co_varnames (codeobject attributo):    Special read-only attributes<2>.
                                                             (line   34)
* code (SystemExit attributo):           Concrete exceptions.
                                                             (line  413)
* code (urllib.error.HTTPError attributo): urllib error — Exception classes raised by urllib request.
                                                             (line   43)
* code (urllib.response.addinfourl attributo): urllib response — Response classes used by urllib.
                                                             (line   40)
* code (xml.etree.ElementTree.ParseError attributo): Exceptions<21>.
                                                             (line   14)
* code (xml.parsers.expat.ExpatError attributo): ExpatError Exceptions.
                                                             (line    9)
* code object:                           Code objects.       (line    6)
* code object <1>:                       marshal — Internal Python object serialization.
                                                             (line   37)
* code object <2>:                       Cell Objects.       (line   58)
* code_context (inspect.FrameInfo attributo): The interpreter stack.
                                                             (line   32)
* code_context (inspect.Traceback attributo): The interpreter stack.
                                                             (line   73)
* code_info() (nel modulo dis):          Analysis functions. (line   11)
* code;block:                            Execution model.    (line    6)
* Codec (classe in codecs):              Stateless Encoding and Decoding.
                                                             (line    9)
* CodecInfo (classe in codecs):          codecs — Codec registry and base classes.
                                                             (line   67)
* CodecRegistryError:                    encodings — Encodings package.
                                                             (line   53)
* Codecs:                                codecs — Codec registry and base classes.
                                                             (line    8)
* Codecs;decode:                         codecs — Codec registry and base classes.
                                                             (line    8)
* Codecs;encode:                         codecs — Codec registry and base classes.
                                                             (line    8)
* codecs.escape_decode() (nel modulo codecs): Standalone Codec Functions.
                                                             (line   22)
* codecs.escape_encode() (nel modulo codecs): Standalone Codec Functions.
                                                             (line   12)
* coded_value (http.cookies.Morsel attributo): Morsel Objects.
                                                             (line   67)
* codepoint2name (nel modulo html.entities): html entities — Definitions of HTML general entities.
                                                             (line   35)
* codes (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   16)
* CODESET (nel modulo locale):           locale — Internationalization services.
                                                             (line  198)
* CodeType (classe in types):            Standard Interpreter Types.
                                                             (line   56)
* codifica;stile:                        Intermezzo Stile di Codifica.
                                                             (line    6)
* col_offset (ast.AST attributo):        Node classes.       (line   50)
* collapse_addresses() (nel modulo ipaddress): Other Module Level Functions.
                                                             (line   43)
* collapse_rfc2231_value() (nel modulo email.utils): email utils Miscellaneous utilities.
                                                             (line  200)
* collect() (nel modulo gc):             gc — Garbage Collector interface.
                                                             (line   34)
* collectedDurations (unittest.TestResult attributo): Loading and running tests.
                                                             (line  279)
* Collection (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   37)
* Collection (classe in typing):         Aliases to container ABCs in collections abc.
                                                             (line   37)
* colno (json.JSONDecodeError attributo): Exceptions<19>.    (line   27)
* colno (re.PatternError attributo):     Exceptions<2>.      (line   32)
* colno (tomllib.TOMLDecodeError attributo): tomllib — Parse TOML files.
                                                             (line   81)
* colno (traceback.FrameSummary attributo): FrameSummary Objects.
                                                             (line   57)
* colon (mailbox.Maildir attributo):     Maildir objects.    (line   45)
* COLON (nel modulo token):              token — Constants used with Python parse trees.
                                                             (line  224)
* COLONEQUAL (nel modulo token):         token — Constants used with Python parse trees.
                                                             (line  350)
* COLOR_BLACK (nel modulo curses):       Constants<6>.       (line  639)
* COLOR_BLUE (nel modulo curses):        Constants<6>.       (line  642)
* color_content() (nel modulo curses):   Functions<5>.       (line   60)
* COLOR_CYAN (nel modulo curses):        Constants<6>.       (line  645)
* COLOR_GREEN (nel modulo curses):       Constants<6>.       (line  648)
* COLOR_MAGENTA (nel modulo curses):     Constants<6>.       (line  651)
* color_pair() (nel modulo curses):      Functions<5>.       (line   68)
* COLOR_PAIRS (nel modulo curses):       Constants<6>.       (line   39)
* COLOR_RED (nel modulo curses):         Constants<6>.       (line  654)
* COLOR_WHITE (nel modulo curses):       Constants<6>.       (line  657)
* COLOR_YELLOW (nel modulo curses):      Constants<6>.       (line  660)
* color() (nel modulo turtle):           Color control.      (line  112)
* colormode() (nel modulo turtle):       Settings and special methods.
                                                             (line   34)
* COLORS (nel modulo curses):            Constants<6>.       (line   34)
* COLS (nel modulo curses):              Constants<6>.       (line   44)
* column() (tkinter.ttk.Treeview metodo): ttk Treeview.      (line   35)
* columnize() (cmd.Cmd metodo):          Cmd Objects.        (line   88)
* COLUMNS:                               Functions<5>.       (line  611)
* COLUMNS <1>:                           Functions<5>.       (line  614)
* columns (os.terminal_size attributo):  Querying the size of a terminal.
                                                             (line   30)
* comb() (nel modulo math):              Number-theoretic functions.
                                                             (line    6)
* combinations_with_replacement() (nel modulo itertools): Itertool Functions.
                                                             (line  172)
* combinations() (nel modulo itertools): Itertool Functions. (line  130)
* combine() (datetime.datetime metodo della classe): datetime Objects.
                                                             (line  180)
* combining() (nel modulo unicodedata):  unicodedata — Unicode Database.
                                                             (line  101)
* Combobox (classe in tkinter.ttk):      ttk Combobox.       (line    6)
* COMError:                              Exceptions<9>.      (line   11)
* comma:                                 Parenthesized forms.
                                                             (line   20)
* COMMA (nel modulo token):              token — Constants used with Python parse trees.
                                                             (line  227)
* command (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  140)
* command line:                          Complete Python programs.
                                                             (line   25)
* command line option; -?:               Generic options.    (line    6)
* command line option; -b:               Miscellaneous options.
                                                             (line    6)
* command line option; -B:               Miscellaneous options.
                                                             (line   16)
* command line option; -build:           Cross Compiling Options.
                                                             (line   12)
* command line option; -c:               Interface options.  (line   37)
* command line option; -check-hash-based-pycs: Miscellaneous options.
                                                             (line   21)
* command line option; -d:               Miscellaneous options.
                                                             (line   35)
* command line option; -disable-gil:     General Options.    (line  218)
* command line option; -disable-ipv6:    General Options.    (line   16)
* command line option; -disable-safety:  Security Options.   (line   57)
* command line option; -disable-test-modules: Install Options.
                                                             (line   24)
* command line option; -E:               Miscellaneous options.
                                                             (line   43)
* command line option; -enable-big-digits: General Options.  (line   21)
* command line option; -enable-bolt:     Performance options.
                                                             (line   63)
* command line option; -enable-experimental-jit: General Options.
                                                             (line  230)
* command line option; -enable-framework: macOS Options.     (line   15)
* command line option; -enable-framework <1>: macOS Options. (line   17)
* command line option; -enable-framework <2>: iOS Options.   (line    8)
* command line option; -enable-loadable-sqlite-extensions: General Options.
                                                             (line    6)
* command line option; -enable-optimizations: Performance options.
                                                             (line   10)
* command line option; -enable-profiling: Performance options.
                                                             (line  139)
* command line option; -enable-pystats:  General Options.    (line  125)
* command line option; -enable-shared:   Linker options<2>.  (line    6)
* command line option; -enable-slower-safety: Security Options.
                                                             (line   76)
* command line option; -enable-universalsdk: macOS Options.  (line    8)
* command line option; -enable-universalsdk <1>: macOS Options.
                                                             (line   10)
* command line option; -enable-wasm-dynamic-linking: WebAssembly Options.
                                                             (line    6)
* command line option; -enable-wasm-pthreads: WebAssembly Options.
                                                             (line   16)
* command line option; -exec-prefix:     Install Options.    (line   16)
* command line option; -h:               Generic options.    (line    6)
* command line option; -help:            Generic options.    (line    6)
* command line option; -help-all:        Generic options.    (line   27)
* command line option; -help-env:        Generic options.    (line   13)
* command line option; -help-xoptions:   Generic options.    (line   20)
* command line option; -host:            Cross Compiling Options.
                                                             (line   16)
* command line option; -i:               Miscellaneous options.
                                                             (line   50)
* command line option; -I:               Miscellaneous options.
                                                             (line   71)
* command line option; -m:               Interface options.  (line   54)
* command line option; -O:               Miscellaneous options.
                                                             (line   83)
* command line option; -OO:              Miscellaneous options.
                                                             (line   93)
* command line option; -P:               Miscellaneous options.
                                                             (line  102)
* command line option; -prefix:          Install Options.    (line    6)
* command line option; -q:               Miscellaneous options.
                                                             (line  121)
* command line option; -R:               Miscellaneous options.
                                                             (line  128)
* command line option; -s:               Miscellaneous options.
                                                             (line  154)
* command line option; -S:               Miscellaneous options.
                                                             (line  166)
* command line option; -u:               Miscellaneous options.
                                                             (line  174)
* command line option; -V:               Generic options.    (line   33)
* command line option; -v:               Miscellaneous options.
                                                             (line  184)
* command line option; -version:         Generic options.    (line   33)
* command line option; -W:               Miscellaneous options.
                                                             (line  197)
* command line option; -with-address-sanitizer: Debug options.
                                                             (line   59)
* command line option; -with-app-store-compliance: macOS Options.
                                                             (line   56)
* command line option; -with-app-store-compliance <1>: macOS Options.
                                                             (line   58)
* command line option; -with-assertions: Debug options.      (line   34)
* command line option; -with-build-python: Cross Compiling Options.
                                                             (line   20)
* command line option; -with-builtin-hashlib-hashes: Security Options.
                                                             (line   21)
* command line option; -with-computed-gotos: Performance options.
                                                             (line  100)
* command line option; -with-dbmliborder: General Options.   (line   68)
* command line option; -with-dtrace:     Debug options.      (line   51)
* command line option; -with-ensurepip:  Install Options.    (line   32)
* command line option; -with-framework-name: macOS Options.  (line   51)
* command line option; -with-framework-name <1>: iOS Options.
                                                             (line   13)
* command line option; -with-hash-algorithm: Security Options.
                                                             (line    6)
* command line option; -with-libc:       Libraries options.  (line   64)
* command line option; -with-libm:       Libraries options.  (line   59)
* command line option; -with-libs:       Libraries options.  (line    6)
* command line option; -with-lto:        Performance options.
                                                             (line   47)
* command line option; -with-memory-sanitizer: Debug options.
                                                             (line   69)
* command line option; -with-openssl:    Libraries options.  (line   69)
* command line option; -with-openssl-rpath: Libraries options.
                                                             (line   75)
* command line option; -with-pkg-config: General Options.    (line  112)
* command line option; -with-platlibdir: General Options.    (line   90)
* command line option; -with-pydebug:    Debug options.      (line    6)
* command line option; -with-readline:   Libraries options.  (line   41)
* command line option; -with-ssl-default-suites: Security Options.
                                                             (line   40)
* command line option; -with-strict-overflow: Performance options.
                                                             (line  143)
* command line option; -with-suffix:     General Options.    (line   32)
* command line option; -with-system-expat: Libraries options.
                                                             (line   10)
* command line option; -with-system-libmpdec: Libraries options.
                                                             (line   15)
* command line option; -with-tail-call-interp: Performance options.
                                                             (line  105)
* command line option; -with-thread-sanitizer: Debug options.
                                                             (line   83)
* command line option; -with-trace-refs: Debug options.      (line   11)
* command line option; -with-tzpath:     General Options.    (line   44)
* command line option; -with-undefined-behavior-sanitizer: Debug options.
                                                             (line   76)
* command line option; -with-universal-archs: macOS Options. (line   23)
* command line option; -with-valgrind:   Debug options.      (line   47)
* command line option; -with-wheel-pkg-dir: General Options. (line  100)
* command line option; -without-c-locale-coercion: General Options.
                                                             (line   81)
* command line option; -without-decimal-contextvar: General Options.
                                                             (line   57)
* command line option; -without-doc-strings: Performance options.
                                                             (line  129)
* command line option; -without-mimalloc: Performance options.
                                                             (line  115)
* command line option; -without-pymalloc: Performance options.
                                                             (line  122)
* command line option; -without-readline: Libraries options. (line   51)
* command line option; -without-remote-debug: Performance options.
                                                             (line  148)
* command line option; -without-static-libpython: Linker options<2>.
                                                             (line   11)
* command line option; -x:               Miscellaneous options.
                                                             (line  258)
* command line option; -X:               Miscellaneous options.
                                                             (line  263)
* command line option; BOLT_APPLY_FLAGS: Performance options.
                                                             (line   88)
* command line option; BOLT_INSTRUMENT_FLAGS: Performance options.
                                                             (line   94)
* command line option; BZIP2_CFLAGS:     Options for third-party dependencies.
                                                             (line    8)
* command line option; BZIP2_LIBS:       Options for third-party dependencies.
                                                             (line   10)
* command line option; CC:               C compiler options. (line    6)
* command line option; CFLAGS:           C compiler options. (line   10)
* command line option; CONFIG_SITE:      Cross Compiling Options.
                                                             (line   26)
* command line option; CPP:              C compiler options. (line   14)
* command line option; CPPFLAGS:         C compiler options. (line   18)
* command line option; CURSES_CFLAGS:    Options for third-party dependencies.
                                                             (line   15)
* command line option; CURSES_LIBS:      Options for third-party dependencies.
                                                             (line   17)
* command line option; GDBM_CFLAGS:      Options for third-party dependencies.
                                                             (line   22)
* command line option; GDBM_LIBS:        Options for third-party dependencies.
                                                             (line   24)
* command line option; HOSTRUNNER:       Cross Compiling Options.
                                                             (line   38)
* command line option; LDFLAGS:          Linker options.     (line    6)
* command line option; LIBEDIT_CFLAGS:   Options for third-party dependencies.
                                                             (line   28)
* command line option; LIBEDIT_LIBS:     Options for third-party dependencies.
                                                             (line   30)
* command line option; LIBFFI_CFLAGS:    Options for third-party dependencies.
                                                             (line   35)
* command line option; LIBFFI_LIBS:      Options for third-party dependencies.
                                                             (line   37)
* command line option; LIBLZMA_CFLAGS:   Options for third-party dependencies.
                                                             (line   52)
* command line option; LIBLZMA_LIBS:     Options for third-party dependencies.
                                                             (line   54)
* command line option; LIBMPDEC_CFLAGS:  Options for third-party dependencies.
                                                             (line   42)
* command line option; LIBMPDEC_LIBS:    Options for third-party dependencies.
                                                             (line   44)
* command line option; LIBREADLINE_CFLAGS: Options for third-party dependencies.
                                                             (line   59)
* command line option; LIBREADLINE_LIBS: Options for third-party dependencies.
                                                             (line   61)
* command line option; LIBS:             Linker options.     (line   10)
* command line option; LIBSQLITE3_CFLAGS: Options for third-party dependencies.
                                                             (line   66)
* command line option; LIBSQLITE3_LIBS:  Options for third-party dependencies.
                                                             (line   68)
* command line option; LIBUUID_CFLAGS:   Options for third-party dependencies.
                                                             (line   73)
* command line option; LIBUUID_LIBS:     Options for third-party dependencies.
                                                             (line   75)
* command line option; LIBZSTD_CFLAGS:   Options for third-party dependencies.
                                                             (line   80)
* command line option; LIBZSTD_LIBS:     Options for third-party dependencies.
                                                             (line   82)
* command line option; MACHDEP:          Linker options.     (line   14)
* command line option; PANEL_CFLAGS:     Options for third-party dependencies.
                                                             (line   89)
* command line option; PANEL_LIBS:       Options for third-party dependencies.
                                                             (line   91)
* command line option; PKG_CONFIG:       General Options.    (line  259)
* command line option; PKG_CONFIG_LIBDIR: General Options.   (line  263)
* command line option; PKG_CONFIG_PATH:  General Options.    (line  265)
* command line option; TCLTK_CFLAGS:     Options for third-party dependencies.
                                                             (line   98)
* command line option; TCLTK_LIBS:       Options for third-party dependencies.
                                                             (line  100)
* command line option; ZLIB_CFLAGS:      Options for third-party dependencies.
                                                             (line  104)
* command line option; ZLIB_LIBS:        Options for third-party dependencies.
                                                             (line  106)
* CommandCompiler (classe in codeop):    codeop — Compile Python code.
                                                             (line   65)
* commands (pdb command):                Debugger commands.  (line  169)
* comment:                               Comments.           (line    6)
* comment (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   62)
* comment (http.cookies.Morsel attributo): Morsel Objects.   (line   13)
* COMMENT (nel modulo token):            token — Constants used with Python parse trees.
                                                             (line   71)
* comment (zipfile.ZipFile attributo):   ZipFile objects.    (line  369)
* comment (zipfile.ZipInfo attributo):   ZipInfo objects.    (line  103)
* comment_url (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   67)
* Comment() (nel modulo xml.etree.ElementTree): Functions<8>.
                                                             (line   72)
* comment() (xml.etree.ElementTree.TreeBuilder metodo): TreeBuilder Objects.
                                                             (line   49)
* comment() (xml.sax.handler.LexicalHandler metodo): LexicalHandler Objects.
                                                             (line   18)
* commenters (shlex.shlex attributo):    shlex Objects.      (line   85)
* CommentHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  386)
* commit() (sqlite3.Connection metodo):  Connection objects. (line   72)
* common (filecmp.dircmp attributo):     The dircmp class.   (line   63)
* Common Vulnerabilities and Exposures; CVE 2008-5983: Build and C API Changes<8>.
                                                             (line   77)
* Common Vulnerabilities and Exposures; CVE 2008-5983 <1>: Build and C API Changes<9>.
                                                             (line   47)
* Common Vulnerabilities and Exposures; CVE 2008-5983 <2>: Process-wide parameters.
                                                             (line  263)
* Common Vulnerabilities and Exposures; CVE 2012-0876: Security<49>.
                                                             (line   23)
* Common Vulnerabilities and Exposures; CVE 2012-0876 <1>: Security<52>.
                                                             (line   14)
* Common Vulnerabilities and Exposures; CVE 2012-0876 <2>: Security<58>.
                                                             (line   14)
* Common Vulnerabilities and Exposures; CVE 2013-0340: Security<29>.
                                                             (line   22)
* Common Vulnerabilities and Exposures; CVE 2013-1753: Library<206>.
                                                             (line  193)
* Common Vulnerabilities and Exposures; CVE 2014-0224: PEP 466 Network Security Enhancements for Python 2 7.
                                                             (line   30)
* Common Vulnerabilities and Exposures; CVE 2014-4616: Library<206>.
                                                             (line 1122)
* Common Vulnerabilities and Exposures; CVE 2015-1283: Security<55>.
                                                             (line    6)
* Common Vulnerabilities and Exposures; CVE 2015-1283 <1>: Security<60>.
                                                             (line    6)
* Common Vulnerabilities and Exposures; CVE 2016-0718: Security<49>.
                                                             (line   22)
* Common Vulnerabilities and Exposures; CVE 2016-0718 <1>: Security<49>.
                                                             (line   23)
* Common Vulnerabilities and Exposures; CVE 2016-0718 <2>: Security<49>.
                                                             (line   35)
* Common Vulnerabilities and Exposures; CVE 2016-0718 <3>: Security<52>.
                                                             (line   13)
* Common Vulnerabilities and Exposures; CVE 2016-0718 <4>: Security<52>.
                                                             (line   14)
* Common Vulnerabilities and Exposures; CVE 2016-0718 <5>: Security<53>.
                                                             (line    7)
* Common Vulnerabilities and Exposures; CVE 2016-0718 <6>: Security<58>.
                                                             (line   13)
* Common Vulnerabilities and Exposures; CVE 2016-0718 <7>: Security<58>.
                                                             (line   14)
* Common Vulnerabilities and Exposures; CVE 2016-0718 <8>: Security<58>.
                                                             (line   26)
* Common Vulnerabilities and Exposures; CVE 2016-0772: Security<55>.
                                                             (line    8)
* Common Vulnerabilities and Exposures; CVE 2016-0772 <1>: Security<60>.
                                                             (line    8)
* Common Vulnerabilities and Exposures; CVE 2016-1000110: Library<185>.
                                                             (line   82)
* Common Vulnerabilities and Exposures; CVE 2016-1000110 <1>: Library<192>.
                                                             (line  267)
* Common Vulnerabilities and Exposures; CVE 2016-2183: Library<184>.
                                                             (line  178)
* Common Vulnerabilities and Exposures; CVE 2016-2183 <1>: Library<192>.
                                                             (line  205)
* Common Vulnerabilities and Exposures; CVE 2016-3189: Windows<30>.
                                                             (line   25)
* Common Vulnerabilities and Exposures; CVE 2016-4472: Security<49>.
                                                             (line   35)
* Common Vulnerabilities and Exposures; CVE 2016-4472 <1>: Security<53>.
                                                             (line    7)
* Common Vulnerabilities and Exposures; CVE 2016-4472 <2>: Security<58>.
                                                             (line   26)
* Common Vulnerabilities and Exposures; CVE 2016-5300: Security<49>.
                                                             (line   24)
* Common Vulnerabilities and Exposures; CVE 2016-5300 <1>: Security<52>.
                                                             (line   15)
* Common Vulnerabilities and Exposures; CVE 2016-5300 <2>: Security<58>.
                                                             (line   15)
* Common Vulnerabilities and Exposures; CVE 2016-9063: Security<49>.
                                                             (line   21)
* Common Vulnerabilities and Exposures; CVE 2016-9063 <1>: Security<52>.
                                                             (line   12)
* Common Vulnerabilities and Exposures; CVE 2016-9063 <2>: Security<58>.
                                                             (line   12)
* Common Vulnerabilities and Exposures; CVE 2017-1000158: Security<57>.
                                                             (line   21)
* Common Vulnerabilities and Exposures; CVE 2017-9233: Security<49>.
                                                             (line   20)
* Common Vulnerabilities and Exposures; CVE 2017-9233 <1>: Security<52>.
                                                             (line   11)
* Common Vulnerabilities and Exposures; CVE 2017-9233 <2>: Security<58>.
                                                             (line   11)
* Common Vulnerabilities and Exposures; CVE 2018-1060: Security<46>.
                                                             (line   48)
* Common Vulnerabilities and Exposures; CVE 2018-1060 <1>: Security<47>.
                                                             (line   15)
* Common Vulnerabilities and Exposures; CVE 2018-1060 <2>: Security<50>.
                                                             (line   11)
* Common Vulnerabilities and Exposures; CVE 2018-1061: Security<46>.
                                                             (line   49)
* Common Vulnerabilities and Exposures; CVE 2018-1061 <1>: Security<47>.
                                                             (line   16)
* Common Vulnerabilities and Exposures; CVE 2018-1061 <2>: Security<50>.
                                                             (line   12)
* Common Vulnerabilities and Exposures; CVE 2018-14647: Security<46>.
                                                             (line   26)
* Common Vulnerabilities and Exposures; CVE 2018-25032: Windows<30>.
                                                             (line    6)
* Common Vulnerabilities and Exposures; CVE 2018-8970: Security<46>.
                                                             (line   38)
* Common Vulnerabilities and Exposures; CVE 2018-8970 <1>: Security<47>.
                                                             (line    6)
* Common Vulnerabilities and Exposures; CVE 2019-12900: Windows<30>.
                                                             (line   26)
* Common Vulnerabilities and Exposures; CVE 2019-15903: Security<42>.
                                                             (line   20)
* Common Vulnerabilities and Exposures; CVE 2019-18348: Security<39>.
                                                             (line    7)
* Common Vulnerabilities and Exposures; CVE 2019-20907: Library<149>.
                                                             (line  186)
* Common Vulnerabilities and Exposures; CVE 2019-5010: Security<46>.
                                                             (line    6)
* Common Vulnerabilities and Exposures; CVE 2019-9740: Security<44>.
                                                             (line    9)
* Common Vulnerabilities and Exposures; CVE 2019-9948: Security<43>.
                                                             (line    6)
* Common Vulnerabilities and Exposures; CVE 2020-10735: Other CPython Implementation Changes.
                                                             (line   56)
* Common Vulnerabilities and Exposures; CVE 2020-10735 <1>: Notable security feature in 3 10 7.
                                                             (line   10)
* Common Vulnerabilities and Exposures; CVE 2020-10735 <2>: Notable security feature in 3 9 14.
                                                             (line   10)
* Common Vulnerabilities and Exposures; CVE 2020-10735 <3>: Notable security feature in 3 8 14.
                                                             (line   10)
* Common Vulnerabilities and Exposures; CVE 2020-10735 <4>: Notable security feature in 3 7 14.
                                                             (line   10)
* Common Vulnerabilities and Exposures; CVE 2020-10735 <5>: Limitazione della lunghezza di conversione delle stringhe di interi.
                                                             (line   22)
* Common Vulnerabilities and Exposures; CVE 2020-15523: Security<36>.
                                                             (line   13)
* Common Vulnerabilities and Exposures; CVE 2020-15801: Security<36>.
                                                             (line    7)
* Common Vulnerabilities and Exposures; CVE 2020-8492: Security<38>.
                                                             (line   11)
* Common Vulnerabilities and Exposures; CVE 2021-3426: Security<31>.
                                                             (line    6)
* Common Vulnerabilities and Exposures; CVE 2022-26488: Windows<30>.
                                                             (line   28)
* Common Vulnerabilities and Exposures; CVE 2022-37434: Windows<27>.
                                                             (line    6)
* Common Vulnerabilities and Exposures; CVE 2022-42919: Security<27>.
                                                             (line   24)
* Common Vulnerabilities and Exposures; CVE 2022-4303: Security<23>.
                                                             (line   10)
* Common Vulnerabilities and Exposures; CVE 2022-4303 <1>: Security<23>.
                                                             (line   11)
* Common Vulnerabilities and Exposures; CVE 2023-0286: Security<23>.
                                                             (line   10)
* Common Vulnerabilities and Exposures; CVE 2023-24329: Security<22>.
                                                             (line   19)
* Common Vulnerabilities and Exposures; CVE 2023-27043: email<2>.
                                                             (line   22)
* Common Vulnerabilities and Exposures; CVE 2023-27043 <1>: Library<61>.
                                                             (line  429)
* Common Vulnerabilities and Exposures; CVE 2023-40217: Security<21>.
                                                             (line   10)
* Common Vulnerabilities and Exposures; CVE 2023-52425: xml. (line    6)
* Common Vulnerabilities and Exposures; CVE 2023-52425 <1>: Security<18>.
                                                             (line    6)
* Common Vulnerabilities and Exposures; CVE 2023-52425 <2>: Documentation<16>.
                                                             (line    6)
* Common Vulnerabilities and Exposures; CVE 2023-52425 <3>: XML security.
                                                             (line   57)
* Common Vulnerabilities and Exposures; CVE 2024-12718: tarfile.
                                                             (line   12)
* Common Vulnerabilities and Exposures; CVE 2024-12718 <1>: tarfile.
                                                             (line   20)
* Common Vulnerabilities and Exposures; CVE 2024-12718 <2>: Security<8>.
                                                             (line   15)
* Common Vulnerabilities and Exposures; CVE 2024-4030: os<2>.
                                                             (line   38)
* Common Vulnerabilities and Exposures; CVE 2024-4030 <1>: tempfile.
                                                             (line    8)
* Common Vulnerabilities and Exposures; CVE 2024-4030 <2>: Security<16>.
                                                             (line   54)
* Common Vulnerabilities and Exposures; CVE 2025-4138: tarfile.
                                                             (line    8)
* Common Vulnerabilities and Exposures; CVE 2025-4138 <1>: Security<8>.
                                                             (line   15)
* Common Vulnerabilities and Exposures; CVE 2025-4330: tarfile.
                                                             (line   19)
* Common Vulnerabilities and Exposures; CVE 2025-4330 <1>: Security<8>.
                                                             (line   15)
* Common Vulnerabilities and Exposures; CVE 2025-4435: tarfile.
                                                             (line   24)
* Common Vulnerabilities and Exposures; CVE 2025-4517: os path.
                                                             (line   10)
* Common Vulnerabilities and Exposures; CVE 2025-4517 <1>: Security<8>.
                                                             (line   16)
* Common Weakness Enumeration; CWE 257:  Recipes and best practices.
                                                             (line   16)
* Common Weakness Enumeration; CWE 295:  ssl<3>.             (line   22)
* Common Weakness Enumeration; CWE 295 <1>: Library<86>.     (line  514)
* common_dirs (filecmp.dircmp attributo): The dircmp class.  (line   75)
* common_files (filecmp.dircmp attributo): The dircmp class. (line   79)
* common_funny (filecmp.dircmp attributo): The dircmp class. (line   83)
* common_types (nel modulo mimetypes):   mimetypes — Map filenames to MIME types.
                                                             (line  161)
* commonpath() (nel modulo os.path):     os path — Common pathname manipulations.
                                                             (line   73)
* commonprefix() (nel modulo os.path):   os path — Common pathname manipulations.
                                                             (line   89)
* communicate() (asyncio.subprocess.Process metodo): Interacting with Subprocesses.
                                                             (line   50)
* communicate() (subprocess.Popen metodo): Popen Objects.    (line   36)
* Compare (classe in ast):               Expressions<2>.     (line   91)
* compare_digest() (nel modulo hmac):    hmac — Keyed-Hashing for Message Authentication.
                                                             (line  116)
* compare_digest() (nel modulo secrets): Other functions.    (line    6)
* compare_networks() (ipaddress.IPv4Network metodo): Network objects.
                                                             (line  237)
* compare_networks() (ipaddress.IPv6Network metodo): Network objects.
                                                             (line  353)
* COMPARE_OP (opcode):                   Python Bytecode Instructions.
                                                             (line  820)
* compare_signal() (decimal.Context metodo): Context objects.
                                                             (line  286)
* compare_signal() (decimal.Decimal metodo): Decimal objects.
                                                             (line  160)
* compare_to() (tracemalloc.Snapshot metodo): Snapshot.      (line   13)
* compare_total_mag() (decimal.Context metodo): Context objects.
                                                             (line  294)
* compare_total_mag() (decimal.Decimal metodo): Decimal objects.
                                                             (line  192)
* compare_total() (decimal.Context metodo): Context objects. (line  290)
* compare_total() (decimal.Decimal metodo): Decimal objects. (line  167)
* compare() (decimal.Context metodo):    Context objects.    (line  282)
* compare() (decimal.Decimal metodo):    Decimal objects.    (line  149)
* compare() (difflib.Differ metodo):     Differ Objects.     (line   38)
* compare() (nel modulo ast):            Compiler flags<2>.  (line   35)
* comparison:                            Comparisons.        (line    6)
* COMPARISON_FLAGS (nel modulo doctest): Option Flags.       (line  102)
* comparisons:                           Basic customization.
                                                             (line  188)
* Compat32 (classe in email.policy):     email policy Policy Objects.
                                                             (line  563)
* compat32 (nel modulo email.policy):    email policy Policy Objects.
                                                             (line  618)
* Compile (classe in codeop):            codeop — Compile Python code.
                                                             (line   56)
* compile_command() (nel modulo code):   code — Interpreter base classes.
                                                             (line   60)
* compile_command() (nel modulo codeop): codeop — Compile Python code.
                                                             (line   29)
* compile_dir() (nel modulo compileall): Public functions.   (line    6)
* compile_file() (nel modulo compileall): Public functions.  (line   96)
* compile_path() (nel modulo compileall): Public functions.  (line  161)
* compile() (nel modulo py_compile):     py_compile — Compile Python source files.
                                                             (line   24)
* compile() (nel modulo re):             Functions.          (line    6)
* compileall command line option; -b:    Command-line use.   (line   66)
* compileall command line option; -d:    Command-line use.   (line   32)
* compileall command line option; -e:    Command-line use.   (line  107)
* compileall command line option; -f:    Command-line use.   (line   22)
* compileall command line option; -hardlink-dupes: Command-line use.
                                                             (line  111)
* compileall command line option; -i:    Command-line use.   (line   60)
* compileall command line option; -invalidation-mode: Command-line use.
                                                             (line   87)
* compileall command line option; -j:    Command-line use.   (line   81)
* compileall command line option; -l:    Command-line use.   (line   17)
* compileall command line option; -o:    Command-line use.   (line  101)
* compileall command line option; -p:    Command-line use.   (line   47)
* compileall command line option; -q:    Command-line use.   (line   26)
* compileall command line option; -r:    Command-line use.   (line   74)
* compileall command line option; -s:    Command-line use.   (line   40)
* compileall command line option; -x:    Command-line use.   (line   54)
* compileall command line option; directory: Command-line use.
                                                             (line    9)
* compileall command line option; file:  Command-line use.   (line    9)
* compiler_flag (__future__._Feature attributo): Module Contents<5>.
                                                             (line   91)
* complete_statement() (nel modulo sqlite3): Module functions.
                                                             (line  104)
* complete() (rlcompleter.Completer metodo): rlcompleter — Completion function for GNU readline.
                                                             (line   43)
* completedefault() (cmd.Cmd metodo):    Cmd Objects.        (line   82)
* CompletedProcess (classe in subprocess): Using the subprocess Module.
                                                             (line  101)
* Completer (classe in rlcompleter):     rlcompleter — Completion function for GNU readline.
                                                             (line   39)
* complex (classe built-in):             Funzioni Incorporate.
                                                             (line  375)
* Complex (classe in numbers):           The numeric tower.  (line    6)
* complex literal:                       Numeric literals.   (line    6)
* complex number:                        Glossary.           (line  319)
* complex;number:                        numbers Complex complex.
                                                             (line    6)
* compound;statement:                    Compound statements.
                                                             (line    6)
* comprehension (classe in ast):         Comprehensions.     (line   58)
* comprehensions:                        Displays for lists sets and dictionaries.
                                                             (line    6)
* compress_size (zipfile.ZipInfo attributo): ZipInfo objects.
                                                             (line  154)
* compress_type (zipfile.ZipInfo attributo): ZipInfo objects.
                                                             (line   99)
* compress() (bz2.BZ2Compressor metodo): Incremental de compression.
                                                             (line   15)
* compress() (compression.zstd.ZstdCompressor metodo): Compressing and decompressing data in memory.
                                                             (line   78)
* compress() (lzma.LZMACompressor metodo): Compressing and decompressing data in memory<2>.
                                                             (line   81)
* compress() (nel modulo bz2):           One-shot de compression.
                                                             (line    6)
* compress() (nel modulo compression.zstd): Compressing and decompressing data in memory.
                                                             (line    6)
* compress() (nel modulo gzip):          gzip — Support for gzip files.
                                                             (line  196)
* compress() (nel modulo itertools):     Itertool Functions. (line  214)
* compress() (nel modulo lzma):          Compressing and decompressing data in memory<2>.
                                                             (line  183)
* compress() (nel modulo zlib):          zlib — Compression compatible with gzip.
                                                             (line   44)
* compress() (zlib.Compress metodo):     zlib — Compression compatible with gzip.
                                                             (line  203)
* compressed (ipaddress.IPv4Address attributo): Address objects.
                                                             (line   62)
* compressed (ipaddress.IPv4Network attributo): Network objects.
                                                             (line  107)
* compressed (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  255)
* compressed (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  320)
* compression_level (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line   39)
* COMPRESSION_LEVEL_DEFAULT (nel modulo compression.zstd): Miscellaneous<2>.
                                                             (line   28)
* compression() (ssl.SSLSocket metodo):  SSL Sockets.        (line  251)
* CompressionError:                      tarfile — Read and write tar archive files.
                                                             (line  255)
* CompressionParameter (classe in compression.zstd): Advanced parameter control.
                                                             (line    6)
* compressobj() (nel modulo zlib):       zlib — Compression compatible with gzip.
                                                             (line   81)
* COMSPEC:                               Process Management. (line  786)
* COMSPEC <1>:                           Popen Constructor.  (line  112)
* concat() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line  188)
* concatenamento;confronti:              Confronti.          (line    6)
* Concatenate (nel modulo typing):       Special forms.      (line   81)
* concatenazione;operazione:             Operazioni Comuni sulle Sequenze.
                                                             (line   22)
* concurrency:                           Glossary.           (line  332)
* concurrent modification:               Glossary.           (line  344)
* cond (bdb.Breakpoint attributo):       bdb — Debugger framework.
                                                             (line   96)
* Condition (classe in asyncio):         Condition.          (line    6)
* Condition (classe in multiprocessing): Synchronization primitives.
                                                             (line   45)
* Condition (classe in threading):       Condition objects.  (line   72)
* condition (pdb command):               Debugger commands.  (line  162)
* Condition() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  174)
* Conditional;expression:                Boolean operations. (line    6)
* conditional;expression:                Conditional expressions.
                                                             (line    6)
* config() (tkinter.font.Font metodo):   tkinter font — Tkinter font wrapper.
                                                             (line   55)
* ConfigParser (classe in configparser): ConfigParser Objects.
                                                             (line    6)
* configuration information:             sysconfig — Provide access to Python’s configuration information.
                                                             (line   10)
* configuration;file:                    configparser — Configuration file parser.
                                                             (line    8)
* configure_mock() (unittest.mock.Mock metodo): The Mock Class.
                                                             (line  265)
* configure() (tkinter.ttk.Style metodo): Ttk Styling.       (line   24)
* CONFORM (enum.FlagBoundary attributo): Data Types<2>.      (line  694)
* confstr_names (nel modulo os):         Miscellaneous System Information.
                                                             (line   28)
* confstr() (nel modulo os):             Miscellaneous System Information.
                                                             (line    6)
* conjugate() (decimal.Decimal metodo):  Decimal objects.    (line  204)
* conjugate() (metodo numero complesso): Tipi Numerici — int float complex.
                                                             (line  104)
* conjugate() (numbers.Complex metodo):  The numeric tower.  (line   23)
* connect_accepted_socket() (asyncio.loop metodo): Creating network servers.
                                                             (line  145)
* connect_ex() (socket.socket metodo):   Socket Objects.     (line   87)
* connect_read_pipe() (asyncio.loop metodo): Working with pipes.
                                                             (line    6)
* connect_write_pipe() (asyncio.loop metodo): Working with pipes.
                                                             (line   22)
* connect() (ftplib.FTP metodo):         FTP objects.        (line   89)
* connect() (http.client.HTTPConnection metodo): HTTPConnection Objects.
                                                             (line  149)
* connect() (multiprocessing.managers.BaseManager metodo): Managers.
                                                             (line   78)
* connect() (nel modulo sqlite3):        Module functions.   (line    6)
* connect() (smtplib.SMTP metodo):       SMTP Objects.       (line   33)
* connect() (socket.socket metodo):      Socket Objects.     (line   63)
* Connection (classe in multiprocessing.connection): Connection Objects.
                                                             (line   13)
* Connection (classe in sqlite3):        Connection objects. (line    6)
* connection (sqlite3.Cursor attributo): Cursor objects.     (line  183)
* connection_lost() (asyncio.BaseProtocol metodo): Base Protocol.
                                                             (line   23)
* connection_made() (asyncio.BaseProtocol metodo): Base Protocol.
                                                             (line   15)
* ConnectionAbortedError:                OS exceptions.      (line   45)
* ConnectionError:                       OS exceptions.      (line   30)
* ConnectionRefusedError:                OS exceptions.      (line   51)
* ConnectionResetError:                  OS exceptions.      (line   57)
* ConnectRegistry() (nel modulo winreg): Functions<13>.      (line   17)
* const (optparse.Option attributo):     Option attributes.  (line   58)
* constant:                              Literals.           (line    6)
* Constant (classe in ast):              Literals<3>.        (line    6)
* constructor() (nel modulo copyreg):    copyreg — Register pickle support functions.
                                                             (line   17)
* consumed (asyncio.LimitOverrunError attributo): Exceptions<15>.
                                                             (line   67)
* container:                             Objects values and types.
                                                             (line   66)
* container <1>:                         Custom classes.     (line   19)
* Container (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line    6)
* Container (classe in typing):          Aliases to container ABCs in collections abc.
                                                             (line   47)
* CONTAINS_OP (opcode):                  Python Bytecode Instructions.
                                                             (line  835)
* contains() (nel modulo operator):      operator — Standard operators as functions.
                                                             (line  193)
* contenitore;iterazione su:             Tipi di Iteratore.  (line    6)
* content (urllib.error.ContentTooShortError attributo): urllib error — Exception classes raised by urllib request.
                                                             (line   72)
* content_disposition (email.headerregistry.ContentDispositionHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  285)
* content_manager (email.policy.EmailPolicy attributo): email policy Policy Objects.
                                                             (line  419)
* content_size_flag (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  179)
* content_type (email.headerregistry.ContentTypeHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  272)
* ContentDispositionHeader (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  280)
* ContentHandler (classe in xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line   18)
* ContentManager (classe in email.contentmanager): email contentmanager Managing MIME Content.
                                                             (line   12)
* contents (ctypes._Pointer attributo):  Arrays and pointers.
                                                             (line   58)
* contents() (importlib.resources.abc.ResourceReader metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line   71)
* contents() (nel modulo importlib.resources): Functional API.
                                                             (line  150)
* ContentTooShortError:                  urllib error — Exception classes raised by urllib request.
                                                             (line   66)
* ContentTransferEncodingHeader (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  290)
* ContentTypeHeader (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  267)
* context:                               Glossary.           (line  351)
* Context (classe in contextvars):       Manual Context Management.
                                                             (line   20)
* Context (classe in decimal):           Context objects.    (line  124)
* context (ssl.SSLSocket attributo):     SSL Sockets.        (line  344)
* context management protocol:           Glossary.           (line  368)
* context manager:                       With Statement Context Managers.
                                                             (line   14)
* context manager <1>:                   Glossary.           (line  372)
* context variable:                      Glossary.           (line  378)
* context_aware_warnings (sys.flags attributo): sys — System-specific parameters and functions.
                                                             (line  601)
* context_diff() (nel modulo difflib):   difflib — Helpers for computing deltas.
                                                             (line  155)
* ContextDecorator (classe in contextlib): Utilities.        (line  382)
* ContextManager (classe in typing):     Aliases to contextlib ABCs.
                                                             (line    6)
* contextmanager() (nel modulo contextlib): Utilities.       (line   31)
* ContextVar (classe in contextvars):    Context Variables.  (line    6)
* CONTIG (inspect.BufferFlags attributo): Buffer flags.      (line   33)
* CONTIG_RO (inspect.BufferFlags attributo): Buffer flags.   (line   35)
* contiguous:                            shape strides suboffsets.
                                                             (line   34)
* contiguous <1>:                        Glossary.           (line  386)
* contiguous (memoryview attributo):     Memory Views.       (line  530)
* Continue (classe in ast):              Control flow.       (line   99)
* CONTINUE (compression.zstd.ZstdCompressor attributo): Compressing and decompressing data in memory.
                                                             (line  131)
* continue (pdb command):                Debugger commands.  (line  237)
* CONTINUOUS (enum.EnumCheck attributo): Data Types<2>.      (line  633)
* control() (select.kqueue metodo):      Kqueue Objects.     (line   22)
* controllo I/O;buffering:               Funzioni Incorporate.
                                                             (line 1539)
* controlnames (nel modulo curses.ascii): curses ascii — Utilities for ASCII characters.
                                                             (line  240)
* CONTTYPE (nel modulo tarfile):         tarfile — Read and write tar archive files.
                                                             (line  353)
* conversion (string.templatelib.Interpolation attributo): Types.
                                                             (line  240)
* convert_arg_line_to_args() (argparse.ArgumentParser metodo): Customizing file parsing.
                                                             (line    6)
* convert_field() (string.Formatter metodo): Custom String Formatting.
                                                             (line  112)
* CONVERT_VALUE (opcode):                Python Bytecode Instructions.
                                                             (line 1216)
* convert() (nel modulo string.templatelib): Helper functions<2>.
                                                             (line    6)
* Cookie (classe in http.cookiejar):     http cookiejar — Cookie handling for HTTP clients.
                                                             (line  113)
* CookieError:                           http cookies — HTTP state management.
                                                             (line   35)
* CookieJar (classe in http.cookiejar):  http cookiejar — Cookie handling for HTTP clients.
                                                             (line   46)
* cookiejar (urllib.request.HTTPCookieProcessor attributo): HTTPCookieProcessor Objects.
                                                             (line    8)
* CookiePolicy (classe in http.cookiejar): http cookiejar — Cookie handling for HTTP clients.
                                                             (line   77)
* Coordinated Universal Time:            time — Time access and conversions.
                                                             (line   39)
* Copy:                                  Help menu Shell and Editor.
                                                             (line   30)
* COPY (opcode):                         Python Bytecode Instructions.
                                                             (line  173)
* copy_abs() (decimal.Context metodo):   Context objects.    (line  299)
* copy_abs() (decimal.Decimal metodo):   Decimal objects.    (line  209)
* copy_context() (nel modulo contextvars): Manual Context Management.
                                                             (line    6)
* copy_decimal() (decimal.Context metodo): Context objects.  (line  206)
* copy_file_range() (nel modulo os):     File Descriptor Operations.
                                                             (line   44)
* COPY_FREE_VARS (opcode):               Python Bytecode Instructions.
                                                             (line 1056)
* copy_into() (pathlib.Path metodo):     Copying moving and deleting.
                                                             (line   31)
* copy_location() (nel modulo ast):      ast helpers.        (line  161)
* copy_negate() (decimal.Context metodo): Context objects.   (line  303)
* copy_negate() (decimal.Decimal metodo): Decimal objects.   (line  215)
* copy_sign() (decimal.Context metodo):  Context objects.    (line  307)
* copy_sign() (decimal.Decimal metodo):  Decimal objects.    (line  221)
* copy;protocol:                         Pickling Class Instances.
                                                             (line  111)
* copy() (collections.deque metodo):     deque objects.      (line   47)
* copy() (contextvars.Context metodo):   Manual Context Management.
                                                             (line  103)
* copy() (decimal.Context metodo):       Context objects.    (line  202)
* copy() (dict metodo):                  Tipi di Mapping — dict.
                                                             (line  170)
* copy() (frozenset metodo):             Tipi di Insiemi — set frozenset.
                                                             (line  134)
* copy() (hashlib.hash metodo):          Hash Objects.       (line   51)
* copy() (hmac.HMAC metodo):             hmac — Keyed-Hashing for Message Authentication.
                                                             (line   86)
* copy() (http.cookies.Morsel metodo):   Morsel Objects.     (line  113)
* copy() (imaplib.IMAP4 metodo):         IMAP4 Objects.      (line   68)
* copy() (nel modulo copy):              copy — Shallow and deep copy operations.
                                                             (line   18)
* copy() (nel modulo multiprocessing.sharedctypes): The multiprocessing sharedctypes module.
                                                             (line   91)
* copy() (nel modulo shutil):            Directory and files operations.
                                                             (line  138)
* copy() (pathlib.Path metodo):          Copying moving and deleting.
                                                             (line    6)
* copy() (sequence metodo):              Tipi di Sequenza Mutabili.
                                                             (line   83)
* copy() (set metodo):                   Tipi di Insiemi — set frozenset.
                                                             (line  134)
* copy() (tkinter.font.Font metodo):     tkinter font — Tkinter font wrapper.
                                                             (line   59)
* copy() (types.MappingProxyType metodo): Standard Interpreter Types.
                                                             (line  260)
* copy() (zlib.Compress metodo):         zlib — Compression compatible with gzip.
                                                             (line  225)
* copy() (zlib.Decompress metodo):       zlib — Compression compatible with gzip.
                                                             (line  294)
* copy2() (nel modulo shutil):           Directory and files operations.
                                                             (line  171)
* CopyComPointer() (nel modulo ctypes):  Utility functions.  (line   33)
* copyfile() (nel modulo shutil):        Directory and files operations.
                                                             (line   25)
* copyfileobj() (nel modulo shutil):     Directory and files operations.
                                                             (line    6)
* copying files:                         shutil — High-level file operations.
                                                             (line    8)
* copymode() (nel modulo shutil):        Directory and files operations.
                                                             (line   75)
* copyright (in module sys):             Process-wide parameters.
                                                             (line  197)
* copyright (nel modulo sys):            sys — System-specific parameters and functions.
                                                             (line  177)
* copyright (variabile built-in):        Constants added by the site module.
                                                             (line   26)
* copysign() (nel modulo math):          Floating point manipulation functions.
                                                             (line    6)
* copystat() (nel modulo shutil):        Directory and files operations.
                                                             (line   93)
* copytree() (nel modulo shutil):        Directory and files operations.
                                                             (line  211)
* coroutine:                             Special method lookup.
                                                             (line   74)
* coroutine <1>:                         Yield expressions.  (line   54)
* coroutine <2>:                         Glossary.           (line  397)
* Coroutine (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  150)
* Coroutine (classe in typing):          Aliases to asynchronous ABCs in collections abc.
                                                             (line    6)
* coroutine function:                    Glossary.           (line  405)
* coroutine;function:                    Coroutine functions.
                                                             (line    6)
* coroutine() (nel modulo types):        Coroutine Utility Functions.
                                                             (line    6)
* CoroutineType (nel modulo types):      Standard Interpreter Types.
                                                             (line   42)
* correlation() (nel modulo statistics): Function details.   (line  580)
* cos() (nel modulo cmath):              Trigonometric functions<2>.
                                                             (line   23)
* cos() (nel modulo math):               Trigonometric functions.
                                                             (line   31)
* cosh() (nel modulo cmath):             Hyperbolic functions<2>.
                                                             (line   23)
* cosh() (nel modulo math):              Hyperbolic functions.
                                                             (line   21)
* count (tracemalloc.Statistic attributo): Statistic.        (line   15)
* count (tracemalloc.StatisticDiff attributo): StatisticDiff.
                                                             (line   15)
* count_diff (tracemalloc.StatisticDiff attributo): StatisticDiff.
                                                             (line   20)
* count() (array.array metodo):          array — Efficient arrays of numeric values.
                                                             (line  154)
* count() (bytearray metodo):            Operazioni su Bytes e Bytearray.
                                                             (line   37)
* count() (bytes metodo):                Operazioni su Bytes e Bytearray.
                                                             (line   37)
* count() (collections.deque metodo):    deque objects.      (line   53)
* count() (memoryview metodo):           Memory Views.       (line  392)
* count() (multiprocessing.shared_memory.ShareableList metodo): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  332)
* count() (nel modulo itertools):        Itertool Functions. (line  227)
* count() (sequence metodo):             Operazioni Comuni sulle Sequenze.
                                                             (line  179)
* count() (str metodo):                  Metodi per le Stringhe.
                                                             (line   70)
* Counter (classe in collections):       Counter objects.    (line   24)
* Counter (classe in typing):            Aliases to types in collections.
                                                             (line   39)
* countOf() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  199)
* countTestCases() (unittest.TestCase metodo): Test cases.   (line  801)
* countTestCases() (unittest.TestSuite metodo): Grouping tests.
                                                             (line   55)
* covariance() (nel modulo statistics):  Function details.   (line  558)
* CoverageResults (classe in trace):     Programmatic Interface.
                                                             (line   47)
* CPPFLAGS:                              New Improved and Deprecated Modules<4>.
                                                             (line   59)
* CPPFLAGS <1>:                          Preprocessor flags. (line    8)
* CPPFLAGS <2>:                          Preprocessor flags. (line   18)
* CPPFLAGS <3>:                          Linker flags.       (line   50)
* cProfile command line option; -m:      Instant User’s Manual.
                                                             (line   99)
* cProfile command line option; -o:      Instant User’s Manual.
                                                             (line   89)
* cProfile command line option; -s:      Instant User’s Manual.
                                                             (line   93)
* CPU time:                              Functions<4>.       (line  247)
* CPU time <1>:                          Functions<4>.       (line  616)
* cpu_count() (nel modulo multiprocessing): Miscellaneous<4>.
                                                             (line   13)
* cpu_count() (nel modulo os):           Miscellaneous System Information.
                                                             (line   37)
* CPython:                               Glossary.           (line  413)
* cpython_only() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  550)
* CR (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line   64)
* crawl_delay() (urllib.robotparser.RobotFileParser metodo): urllib robotparser — Parser for robots txt.
                                                             (line   50)
* CRC (zipfile.ZipInfo attributo):       ZipInfo objects.    (line  150)
* crc_hqx() (nel modulo binascii):       binascii — Convert between binary and ASCII.
                                                             (line   91)
* crc32() (nel modulo binascii):         binascii — Convert between binary and ASCII.
                                                             (line   98)
* crc32() (nel modulo zlib):             zlib — Compression compatible with gzip.
                                                             (line  121)
* create_aggregate() (sqlite3.Connection metodo): Connection objects.
                                                             (line  158)
* create_archive() (nel modulo zipapp):  Python API.         (line    8)
* create_autospec() (nel modulo unittest.mock): create_autospec.
                                                             (line    6)
* CREATE_BREAKAWAY_FROM_JOB (nel modulo subprocess): Windows Constants.
                                                             (line  140)
* create_collation() (sqlite3.Connection metodo): Connection objects.
                                                             (line  302)
* create_configuration() (venv.EnvBuilder metodo): API<2>.   (line  149)
* create_connection() (asyncio.loop metodo): Opening network connections.
                                                             (line    6)
* create_connection() (nel modulo socket): Creating sockets. (line   84)
* create_datagram_endpoint() (asyncio.loop metodo): Opening network connections.
                                                             (line  157)
* create_decimal_from_float() (decimal.Context metodo): Context objects.
                                                             (line  234)
* create_decimal() (decimal.Context metodo): Context objects.
                                                             (line  210)
* create_default_context() (nel modulo ssl): Context creation.
                                                             (line    9)
* CREATE_DEFAULT_ERROR_MODE (nel modulo subprocess): Windows Constants.
                                                             (line  130)
* create_eager_task_factory() (nel modulo asyncio): Eager Task Factory.
                                                             (line   32)
* create_empty_file() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   95)
* create_function() (sqlite3.Connection metodo): Connection objects.
                                                             (line  115)
* create_future() (asyncio.loop metodo): Creating Futures and Tasks.
                                                             (line    6)
* create_git_ignore_file() (venv.EnvBuilder metodo): API<2>. (line  216)
* create_module() (importlib.abc.Loader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  103)
* create_module() (importlib.machinery.ExtensionFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  315)
* create_module() (zipimport.zipimporter metodo): zipimporter Objects.
                                                             (line   23)
* CREATE_NEW_CONSOLE (nel modulo subprocess): Windows Constants.
                                                             (line   54)
* CREATE_NEW_PROCESS_GROUP (nel modulo subprocess): Windows Constants.
                                                             (line   59)
* CREATE_NO_WINDOW (nel modulo subprocess): Windows Constants.
                                                             (line  115)
* create_queue() (nel modulo concurrent.interpreters): Reference<4>.
                                                             (line   30)
* create_server() (asyncio.loop metodo): Creating network servers.
                                                             (line    6)
* create_server() (nel modulo socket):   Creating sockets.   (line  115)
* create_stats() (profile.Profile metodo): profile and cProfile Module Reference.
                                                             (line   86)
* create_string_buffer() (nel modulo ctypes): Utility functions.
                                                             (line   57)
* create_subprocess_exec() (nel modulo asyncio): Creating Subprocesses.
                                                             (line    6)
* create_subprocess_shell() (nel modulo asyncio): Creating Subprocesses.
                                                             (line   26)
* create_system (zipfile.ZipInfo attributo): ZipInfo objects.
                                                             (line  114)
* create_task() (asyncio.loop metodo):   Creating Futures and Tasks.
                                                             (line   17)
* create_task() (asyncio.TaskGroup metodo): Task Groups.     (line   17)
* create_task() (nel modulo asyncio):    Creating Tasks.     (line   10)
* create_unicode_buffer() (nel modulo ctypes): Utility functions.
                                                             (line   99)
* create_unix_connection() (asyncio.loop metodo): Opening network connections.
                                                             (line  243)
* create_unix_server() (asyncio.loop metodo): Creating network servers.
                                                             (line  115)
* create_version (zipfile.ZipInfo attributo): ZipInfo objects.
                                                             (line  118)
* create_window_function() (sqlite3.Connection metodo): Connection objects.
                                                             (line  213)
* create() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line   72)
* create() (nel modulo concurrent.interpreters): Reference<4>.
                                                             (line   25)
* create() (nel modulo venv):            API<2>.             (line  236)
* create() (venv.EnvBuilder metodo):     API<2>.             (line   63)
* createAttribute() (xml.dom.Document metodo): Document Objects.
                                                             (line   46)
* createAttributeNS() (xml.dom.Document metodo): Document Objects.
                                                             (line   53)
* createComment() (xml.dom.Document metodo): Document Objects.
                                                             (line   34)
* createDocument() (xml.dom.DOMImplementation metodo): DOMImplementation Objects.
                                                             (line   16)
* createDocumentType() (xml.dom.DOMImplementation metodo): DOMImplementation Objects.
                                                             (line   26)
* createElement() (xml.dom.Document metodo): Document Objects.
                                                             (line   14)
* createElementNS() (xml.dom.Document metodo): Document Objects.
                                                             (line   21)
* createfilehandler() (_tkinter.Widget.tk metodo): File Handlers.
                                                             (line   27)
* CreateKey() (nel modulo winreg):       Functions<13>.      (line   35)
* CreateKeyEx() (nel modulo winreg):     Functions<13>.      (line   63)
* createLock() (logging.Handler metodo): Handler Objects.    (line   20)
* createLock() (logging.NullHandler metodo): NullHandler.    (line   24)
* createProcessingInstruction() (xml.dom.Document metodo): Document Objects.
                                                             (line   40)
* createSocket() (logging.handlers.SocketHandler metodo): SocketHandler.
                                                             (line   72)
* createSocket() (logging.handlers.SysLogHandler metodo): SysLogHandler.
                                                             (line   56)
* createTextNode() (xml.dom.Document metodo): Document Objects.
                                                             (line   28)
* credits (variabile built-in):          Constants added by the site module.
                                                             (line   26)
* CRITICAL (nel modulo logging):         Logging Levels.     (line   45)
* critical() (logging.Logger metodo):    Logger Objects.     (line  309)
* critical() (nel modulo logging):       Module-Level Functions.
                                                             (line   86)
* CRNCYSTR (nel modulo locale):          locale — Internationalization services.
                                                             (line  306)
* CRT_ASSEMBLY_VERSION (nel modulo msvcrt): Other Functions. (line   89)
* CRT_ASSERT (nel modulo msvcrt):        Other Functions.    (line   66)
* CRT_ERROR (nel modulo msvcrt):         Other Functions.    (line   61)
* CRT_WARN (nel modulo msvcrt):          Other Functions.    (line   56)
* CRTDBG_MODE_DEBUG (nel modulo msvcrt): Other Functions.    (line   70)
* CRTDBG_MODE_FILE (nel modulo msvcrt):  Other Functions.    (line   74)
* CRTDBG_MODE_WNDW (nel modulo msvcrt):  Other Functions.    (line   80)
* CRTDBG_REPORT_MODE (nel modulo msvcrt): Other Functions.   (line   85)
* CrtSetReportFile() (nel modulo msvcrt): Other Functions.   (line   48)
* CrtSetReportMode() (nel modulo msvcrt): Other Functions.   (line   40)
* cryptography:                          Cryptographic Services.
                                                             (line    6)
* cssclass_month (calendar.HTMLCalendar attributo): calendar — General calendar-related functions.
                                                             (line  293)
* cssclass_month_head (calendar.HTMLCalendar attributo): calendar — General calendar-related functions.
                                                             (line  286)
* cssclass_noday (calendar.HTMLCalendar attributo): calendar — General calendar-related functions.
                                                             (line  272)
* cssclass_year (calendar.HTMLCalendar attributo): calendar — General calendar-related functions.
                                                             (line  300)
* cssclass_year_head (calendar.HTMLCalendar attributo): calendar — General calendar-related functions.
                                                             (line  307)
* cssclasses (calendar.HTMLCalendar attributo): calendar — General calendar-related functions.
                                                             (line  259)
* cssclasses_weekday_head (calendar.HTMLCalendar attributo): calendar — General calendar-related functions.
                                                             (line  279)
* csv:                                   csv — CSV File Reading and Writing.
                                                             (line    8)
* cte (email.headerregistry.ContentTransferEncodingHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  294)
* cte_type (email.policy.Policy attributo): email policy Policy Objects.
                                                             (line  160)
* ctermid() (nel modulo os):             Process Parameters. (line    9)
* ctime() (datetime.date metodo):        date Objects.       (line  314)
* ctime() (datetime.datetime metodo):    datetime Objects.   (line  736)
* ctime() (nel modulo time):             Functions<4>.       (line   93)
* CTRL_BREAK_EVENT (nel modulo signal):  Module contents<2>. (line  227)
* CTRL_C_EVENT (nel modulo signal):      Module contents<2>. (line  218)
* ctrl() (nel modulo curses.ascii):      curses ascii — Utilities for ASCII characters.
                                                             (line  216)
* curdir (nel modulo os):                Miscellaneous System Information.
                                                             (line  104)
* currency() (nel modulo locale):        locale — Internationalization services.
                                                             (line  490)
* current context:                       Glossary.           (line  420)
* current_process() (nel modulo multiprocessing): Miscellaneous<4>.
                                                             (line   35)
* current_task() (nel modulo asyncio):   Introspection.      (line    6)
* current_thread() (nel modulo threading): Reference<2>.     (line   16)
* current() (tkinter.ttk.Combobox metodo): ttk Combobox.     (line    8)
* CurrentByteIndex (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  245)
* CurrentColumnNumber (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  249)
* currentframe() (nel modulo inspect):   The interpreter stack.
                                                             (line  163)
* CurrentLineNumber (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  253)
* curs_set() (nel modulo curses):        Functions<5>.       (line   76)
* Cursor (classe in sqlite3):            Cursor objects.     (line   19)
* cursor() (sqlite3.Connection metodo):  Connection objects. (line   27)
* cursyncup() (curses.window metodo):    Window Objects.     (line  174)
* Cut:                                   Help menu Shell and Editor.
                                                             (line   30)
* cutoff (sys.hash_info attributo):      sys — System-specific parameters and functions.
                                                             (line 1104)
* cwd() (ftplib.FTP metodo):             FTP objects.        (line  337)
* cwd() (pathlib.Path metodo della classe): Expanding and resolving paths.
                                                             (line   30)
* cycle() (nel modulo itertools):        Itertool Functions. (line  249)
* CycleError:                            Exceptions<3>.      (line    8)
* cyclic isolate:                        Glossary.           (line  430)
* Cyclic Redundancy Check:               zlib — Compression compatible with gzip.
                                                             (line  123)
* D_FMT (nel modulo locale):             locale — Internationalization services.
                                                             (line  209)
* D_T_FMT (nel modulo locale):           locale — Internationalization services.
                                                             (line  203)
* daemon (multiprocessing.Process attributo): Process and exceptions.
                                                             (line  134)
* daemon (threading.Thread attributo):   Thread objects.     (line  240)
* daemon_threads (socketserver.ThreadingMixIn attributo): Server Creation Notes.
                                                             (line   62)
* dangling;else:                         Compound statements.
                                                             (line   55)
* data:                                  Objects values and types.
                                                             (line    6)
* data (collections.UserDict attributo): UserDict objects.   (line   24)
* data (collections.UserList attributo): UserList objects.   (line   29)
* data (collections.UserString attributo): UserString objects.
                                                             (line   24)
* data (plistlib.UID attributo):         plistlib — Generate and parse Apple plist files.
                                                             (line  147)
* data (select.kevent attributo):        Kevent Objects.     (line  175)
* data (selectors.SelectorKey attributo): Classes<3>.        (line   48)
* data (urllib.request.Request attributo): Request Objects.  (line   39)
* data (xml.dom.Comment attributo):      Comment Objects.    (line    9)
* data (xml.dom.ProcessingInstruction attributo): ProcessingInstruction Objects.
                                                             (line   14)
* data (xml.dom.Text attributo):         Text and CDATASection Objects.
                                                             (line   15)
* data (xmlrpc.client.Binary attributo): Binary Objects.     (line   12)
* data race:                             Glossary.           (line  438)
* data_filter() (nel modulo tarfile):    Default named filters.
                                                             (line   36)
* data_open() (urllib.request.DataHandler metodo): DataHandler Objects.
                                                             (line    6)
* data_received() (asyncio.Protocol metodo): Streaming Protocols.
                                                             (line   13)
* data;tabular:                          csv — CSV File Reading and Writing.
                                                             (line    8)
* data;type:                             The standard type hierarchy.
                                                             (line    6)
* data() (xml.etree.ElementTree.TreeBuilder metodo): TreeBuilder Objects.
                                                             (line   33)
* DatabaseError:                         Exceptions<6>.      (line   44)
* databases:                             dbm dumb — Portable DBM implementation.
                                                             (line    8)
* dataclass_transform() (nel modulo typing): Functions and decorators.
                                                             (line  114)
* dataclass() (nel modulo dataclasses):  Module contents<4>. (line    6)
* DataError:                             Exceptions<6>.      (line   51)
* datagram_received() (asyncio.DatagramProtocol metodo): Datagram Protocols.
                                                             (line    9)
* DatagramHandler (classe in logging.handlers): DatagramHandler.
                                                             (line   10)
* DatagramProtocol (classe in asyncio):  Base Protocols.     (line   20)
* DatagramRequestHandler (classe in socketserver): Request Handler Objects.
                                                             (line   56)
* DatagramTransport (classe in asyncio): Transports Hierarchy.
                                                             (line   43)
* DataHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  475)
* date (classe in datetime):             date Objects.       (line   13)
* date_time (zipfile.ZipInfo attributo): ZipInfo objects.    (line   55)
* date_time_string() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  367)
* date() (datetime.datetime metodo):     datetime Objects.   (line  442)
* DateHeader (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  136)
* datetime (classe in datetime):         datetime Objects.   (line   17)
* DateTime (classe in xmlrpc.client):    DateTime Objects.   (line    6)
* datetime (email.headerregistry.DateHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  145)
* Day (classe in calendar):              calendar — General calendar-related functions.
                                                             (line  460)
* day (datetime.date attributo):         date Objects.       (line  154)
* day (datetime.datetime attributo):     datetime Objects.   (line  313)
* DAY_1 (nel modulo locale):             locale — Internationalization services.
                                                             (line  226)
* DAY_2 (nel modulo locale):             locale — Internationalization services.
                                                             (line  226)
* DAY_3 (nel modulo locale):             locale — Internationalization services.
                                                             (line  226)
* DAY_4 (nel modulo locale):             locale — Internationalization services.
                                                             (line  226)
* DAY_5 (nel modulo locale):             locale — Internationalization services.
                                                             (line  226)
* DAY_6 (nel modulo locale):             locale — Internationalization services.
                                                             (line  226)
* DAY_7 (nel modulo locale):             locale — Internationalization services.
                                                             (line  226)
* day_abbr (nel modulo calendar):        calendar — General calendar-related functions.
                                                             (line  438)
* day_name (nel modulo calendar):        calendar — General calendar-related functions.
                                                             (line  429)
* daylight (nel modulo time):            Timezone Constants. (line   13)
* Daylight Saving Time:                  time — Time access and conversions.
                                                             (line   45)
* days (datetime.timedelta attributo):   timedelta Objects.  (line  110)
* DbfilenameShelf (classe in shelve):    Restrictions.       (line   73)
* DC1 (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   76)
* DC2 (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   79)
* DC3 (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   82)
* DC4 (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   85)
* dcgettext() (nel modulo locale):       Access to message catalogs.
                                                             (line   10)
* deactivate_stack_trampoline() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line 1906)
* deadlock:                              Glossary.           (line  450)
* deallocation, object:                  Finalization and De-allocation.
                                                             (line    6)
* debug (imaplib.IMAP4 attributo):       IMAP4 Objects.      (line  479)
* DEBUG (nel modulo logging):            Logging Levels.     (line   24)
* DEBUG (nel modulo re):                 Flags.              (line   32)
* debug (pdb command):                   Debugger commands.  (line  456)
* debug (shlex.shlex attributo):         shlex Objects.      (line  162)
* debug (sys.flags attributo):           sys — System-specific parameters and functions.
                                                             (line  538)
* debug (zipfile.ZipFile attributo):     ZipFile objects.    (line  363)
* DEBUG_BYTECODE_SUFFIXES (nel modulo importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line   20)
* DEBUG_COLLECTABLE (nel modulo gc):     gc — Garbage Collector interface.
                                                             (line  334)
* DEBUG_LEAK (nel modulo gc):            gc — Garbage Collector interface.
                                                             (line  354)
* DEBUG_SAVEALL (nel modulo gc):         gc — Garbage Collector interface.
                                                             (line  348)
* debug_src() (nel modulo doctest):      Debugging.          (line  147)
* DEBUG_STATS (nel modulo gc):           gc — Garbage Collector interface.
                                                             (line  329)
* DEBUG_UNCOLLECTABLE (nel modulo gc):   gc — Garbage Collector interface.
                                                             (line  338)
* debug() (logging.Logger metodo):       Logger Objects.     (line  186)
* debug() (nel modulo doctest):          Debugging.          (line  124)
* debug() (nel modulo logging):          Module-Level Functions.
                                                             (line   46)
* debug() (unittest.TestCase metodo):    Test cases.         (line  120)
* debug() (unittest.TestSuite metodo):   Grouping tests.     (line   48)
* debugger:                              Reference<2>.       (line  132)
* debugger <1>:                          Debug menu Shell window only.
                                                             (line   15)
* debugger <2>:                          sys — System-specific parameters and functions.
                                                             (line  979)
* debugger <3>:                          sys — System-specific parameters and functions.
                                                             (line 1743)
* debugger;configuration;file:           Debugger commands.  (line   63)
* debugging:                             pdb — The Python Debugger.
                                                             (line    8)
* debugging;assertions:                  The assert statement.
                                                             (line    6)
* debuglevel (http.client.HTTPResponse attributo): HTTPResponse Objects.
                                                             (line   69)
* DebugRunner (classe in doctest):       Debugging.          (line  168)
* DECEMBER (nel modulo calendar):        calendar — General calendar-related functions.
                                                             (line  490)
* Decimal (classe in decimal):           Decimal objects.    (line    6)
* decimal literal:                       Numeric literals.   (line    6)
* decimal() (nel modulo unicodedata):    unicodedata — Unicode Database.
                                                             (line   51)
* DecimalException (classe in decimal):  Signals.            (line   29)
* decode (codecs.CodecInfo attributo):   codecs — Codec registry and base classes.
                                                             (line   78)
* decode_header() (nel modulo email.header): email header Internationalized headers.
                                                             (line  183)
* decode_params() (nel modulo email.utils): email utils Miscellaneous utilities.
                                                             (line  217)
* decode_rfc2231() (nel modulo email.utils): email utils Miscellaneous utilities.
                                                             (line  187)
* decode_source() (nel modulo importlib.util): importlib util – Utility code for importers.
                                                             (line   72)
* decode() (bytearray metodo):           Operazioni su Bytes e Bytearray.
                                                             (line   94)
* decode() (bytes metodo):               Operazioni su Bytes e Bytearray.
                                                             (line   94)
* decode() (codecs.Codec metodo):        Stateless Encoding and Decoding.
                                                             (line   29)
* decode() (codecs.IncrementalDecoder metodo): IncrementalDecoder Objects.
                                                             (line   28)
* decode() (json.JSONDecoder metodo):    Encoders and Decoders.
                                                             (line   87)
* decode() (nel modulo base64):          Legacy Interface.   (line    6)
* decode() (nel modulo codecs):          codecs — Codec registry and base classes.
                                                             (line   34)
* decode() (nel modulo quopri):          quopri — Encode and decode MIME quoted-printable data.
                                                             (line   19)
* decode() (xmlrpc.client.Binary metodo): Binary Objects.    (line   20)
* decode() (xmlrpc.client.DateTime metodo): DateTime Objects.
                                                             (line   13)
* decodebytes() (nel modulo base64):     Legacy Interface.   (line   13)
* DecodedGenerator (classe in email.generator): email generator Generating MIME documents.
                                                             (line  233)
* decodestring() (nel modulo quopri):    quopri — Encode and decode MIME quoted-printable data.
                                                             (line   41)
* decomposition() (nel modulo unicodedata): unicodedata — Unicode Database.
                                                             (line  124)
* decompress() (bz2.BZ2Decompressor metodo): Incremental de compression.
                                                             (line   45)
* decompress() (compression.zstd.ZstdDecompressor metodo): Compressing and decompressing data in memory.
                                                             (line  186)
* decompress() (lzma.LZMADecompressor metodo): Compressing and decompressing data in memory<2>.
                                                             (line  132)
* decompress() (nel modulo bz2):         One-shot de compression.
                                                             (line   16)
* decompress() (nel modulo compression.zstd): Compressing and decompressing data in memory.
                                                             (line   31)
* decompress() (nel modulo gzip):        gzip — Support for gzip files.
                                                             (line  223)
* decompress() (nel modulo lzma):        Compressing and decompressing data in memory<2>.
                                                             (line  192)
* decompress() (nel modulo zlib):        zlib — Compression compatible with gzip.
                                                             (line  135)
* decompress() (zlib.Decompress metodo): zlib — Compression compatible with gzip.
                                                             (line  263)
* decompressed_size (compression.zstd.FrameInfo attributo): Miscellaneous<2>.
                                                             (line   16)
* DecompressionParameter (classe in compression.zstd): Advanced parameter control.
                                                             (line  259)
* decompressobj() (nel modulo zlib):     zlib — Compression compatible with gzip.
                                                             (line  180)
* decorator:                             Glossary.           (line  463)
* DEDENT (nel modulo token):             token — Constants used with Python parse trees.
                                                             (line   91)
* DEDENT token:                          Indentation.        (line   33)
* DEDENT token <1>:                      Compound statements.
                                                             (line   55)
* dedent() (nel modulo textwrap):        textwrap — Text wrapping and filling.
                                                             (line   77)
* deepcopy() (nel modulo copy):          copy — Shallow and deep copy operations.
                                                             (line   22)
* DEF_BUF_SIZE (nel modulo zlib):        zlib — Compression compatible with gzip.
                                                             (line  320)
* DEF_MEM_LEVEL (nel modulo zlib):       zlib — Compression compatible with gzip.
                                                             (line  316)
* def_prog_mode() (nel modulo curses):   Functions<5>.       (line   85)
* def_shell_mode() (nel modulo curses):  Functions<5>.       (line   92)
* default (inspect.Parameter attributo): Introspecting callables with the Signature object.
                                                             (line  236)
* default (nel modulo email.policy):     email policy Policy Objects.
                                                             (line  504)
* DEFAULT (nel modulo unittest.mock):    DEFAULT.            (line    6)
* default (optparse.Option attributo):   Option attributes.  (line   44)
* DEFAULT_BUFFER_SIZE (nel modulo io):   High-level Module Interface.
                                                             (line    6)
* default_bufsize (nel modulo xml.dom.pulldom): xml dom pulldom — Support for building partial DOM trees.
                                                             (line  103)
* default_exception_handler() (asyncio.loop metodo): Error Handling API.
                                                             (line   34)
* default_factory (collections.defaultdict attributo): defaultdict objects.
                                                             (line   50)
* DEFAULT_FORMAT (nel modulo tarfile):   tarfile — Read and write tar archive files.
                                                             (line  385)
* DEFAULT_IGNORES (nel modulo filecmp):  The dircmp class.   (line  115)
* default_loader() (nel modulo xml.etree.ElementInclude): Functions<9>.
                                                             (line    6)
* default_max_str_digits (sys.int_info attributo): sys — System-specific parameters and functions.
                                                             (line 1207)
* default_open() (urllib.request.BaseHandler metodo): BaseHandler Objects.
                                                             (line   30)
* DEFAULT_PROTOCOL (nel modulo pickle):  Module Interface.   (line   21)
* DEFAULT_TIMEOUT (unittest.mock.ThreadingMock attributo): The Mock Class.
                                                             (line 1000)
* default_timer() (nel modulo timeit):   Python Interface.   (line   34)
* default;parameter;value:               Function definitions.
                                                             (line   69)
* default() (cmd.Cmd metodo):            Cmd Objects.        (line   76)
* default() (json.JSONEncoder metodo):   Encoders and Decoders.
                                                             (line  202)
* DefaultContext (nel modulo decimal):   Context objects.    (line   99)
* DefaultCookiePolicy (classe in http.cookiejar): http cookiejar — Cookie handling for HTTP clients.
                                                             (line   82)
* defaultdict (classe in collections):   defaultdict objects.
                                                             (line    6)
* DefaultDict (classe in typing):        Aliases to types in collections.
                                                             (line    6)
* DefaultEventLoopPolicy (classe in asyncio): Policy Objects.
                                                             (line   38)
* DefaultHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  401)
* DefaultHandlerExpand() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  408)
* defaults() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  113)
* DefaultSelector (classe in selectors): Classes<3>.         (line  161)
* defaultTestLoader (nel modulo unittest): Loading and running tests.
                                                             (line  460)
* defaultTestResult() (unittest.TestCase metodo): Test cases.
                                                             (line  806)
* defects (email.headerregistry.BaseHeader attributo): email headerregistry Custom Header Objects.
                                                             (line   52)
* defects (email.message.EmailMessage attributo): email message Representing an email message.
                                                             (line  712)
* defects (email.message.Message attributo): email message Message Representing an email message using the compat32 API.
                                                             (line  728)
* definizione;for:                       Istruzioni for.     (line    6)
* DEFLATED (nel modulo zlib):            zlib — Compression compatible with gzip.
                                                             (line  307)
* defpath (nel modulo os):               Miscellaneous System Information.
                                                             (line  144)
* DefragResult (classe in urllib.parse): Structured Parse Results.
                                                             (line   40)
* DefragResultBytes (classe in urllib.parse): Structured Parse Results.
                                                             (line   65)
* degrees() (nel modulo math):           Angular conversion. (line    6)
* degrees() (nel modulo turtle):         Settings for measurement.
                                                             (line    6)
* Del (classe in ast):                   Variables.          (line   11)
* DEL (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line  124)
* del_param() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  383)
* del_param() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  546)
* delay_output() (nel modulo curses):    Functions<5>.       (line  100)
* delay() (nel modulo turtle):           Animation control.  (line   19)
* delayload (http.cookiejar.FileCookieJar attributo): CookieJar and FileCookieJar Objects.
                                                             (line  159)
* delch() (curses.window metodo):        Window Objects.     (line  179)
* dele() (poplib.POP3 metodo):           POP3 Objects.       (line   68)
* Delete (classe in ast):                Statements.         (line  139)
* DELETE_ATTR (opcode):                  Python Bytecode Instructions.
                                                             (line  601)
* DELETE_DEREF (opcode):                 Python Bytecode Instructions.
                                                             (line 1046)
* DELETE_FAST (opcode):                  Python Bytecode Instructions.
                                                             (line 1007)
* DELETE_GLOBAL (opcode):                Python Bytecode Instructions.
                                                             (line  615)
* DELETE_NAME (opcode):                  Python Bytecode Instructions.
                                                             (line  555)
* DELETE_SUBSCR (opcode):                Python Bytecode Instructions.
                                                             (line  279)
* delete() (ftplib.FTP metodo):          FTP objects.        (line  330)
* delete() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line   76)
* delete() (tkinter.ttk.Treeview metodo): ttk Treeview.      (line   73)
* deleteacl() (imaplib.IMAP4 metodo):    IMAP4 Objects.      (line   80)
* deletefilehandler() (_tkinter.Widget.tk metodo): File Handlers.
                                                             (line   37)
* DeleteKey() (nel modulo winreg):       Functions<13>.      (line  102)
* DeleteKeyEx() (nel modulo winreg):     Functions<13>.      (line  124)
* deleteln() (curses.window metodo):     Window Objects.     (line  183)
* deleteMe() (bdb.Breakpoint metodo):    bdb — Debugger framework.
                                                             (line   42)
* DeleteValue() (nel modulo winreg):     Functions<13>.      (line  160)
* deletion;target:                       The del statement.  (line    6)
* deletion;target;list:                  The del statement.  (line    6)
* delimiter (csv.Dialect attributo):     Dialects and Formatting Parameters.
                                                             (line   19)
* delimiters:                            Operators and delimiters.
                                                             (line    6)
* delitem() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  203)
* deliver_challenge() (nel modulo multiprocessing.connection): Listeners and Clients.
                                                             (line   15)
* delocalize() (nel modulo locale):      locale — Internationalization services.
                                                             (line  511)
* demo_app() (nel modulo wsgiref.simple_server): wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line   36)
* denominator (fractions.Fraction attributo): fractions — Rational numbers.
                                                             (line  121)
* denominator (numbers.Rational attributo): The numeric tower.
                                                             (line   55)
* deprecated() (nel modulo warnings):    Available Functions.
                                                             (line  141)
* DeprecationWarning:                    Warnings.           (line   17)
* deque (classe in collections):         deque objects.      (line    6)
* Deque (classe in typing):              Aliases to types in collections.
                                                             (line   49)
* dequeue() (logging.handlers.QueueListener metodo): QueueListener.
                                                             (line   56)
* DER_cert_to_PEM_cert() (nel modulo ssl): Certificate handling.
                                                             (line   52)
* derive() (BaseExceptionGroup metodo):  Exception groups.   (line   76)
* derwin() (curses.window metodo):       Window Objects.     (line  188)
* descrgetfunc (C type):                 Slot Type typedefs. (line   69)
* description (inspect.Parameter.kind attributo): Introspecting callables with the Signature object.
                                                             (line  302)
* description (sqlite3.Cursor attributo): Cursor objects.    (line  196)
* descriptor:                            Glossary.           (line  485)
* descrsetfunc (C type):                 Slot Type typedefs. (line   73)
* deserialize() (sqlite3.Connection metodo): Connection objects.
                                                             (line  699)
* dest (optparse.Option attributo):      Option attributes.  (line   35)
* destructor:                            Basic customization.
                                                             (line   55)
* destructor <1>:                        Assignment statements.
                                                             (line   71)
* destructor (C type):                   Slot Type typedefs. (line   24)
* detach() (io.BufferedIOBase metodo):   I/O Base Classes.   (line  259)
* detach() (io.TextIOBase metodo):       Text I/O<2>.        (line   37)
* detach() (socket.socket metodo):       Socket Objects.     (line  101)
* detach() (tkinter.ttk.Treeview metodo): ttk Treeview.      (line   79)
* detach() (weakref.finalize metodo):    weakref — Weak references.
                                                             (line  301)
* Detach() (winreg.PyHKEY metodo):       Registry Handle Objects.
                                                             (line   36)
* DETACHED_PROCESS (nel modulo subprocess): Windows Constants.
                                                             (line  122)
* details (ctypes.COMError attributo):   Exceptions<9>.      (line   23)
* detect_api_mismatch() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  674)
* detect_encoding() (nel modulo tokenize): Tokenizing Input. (line   76)
* deterministic profiling:               Introduction to the profilers.
                                                             (line    6)
* dev_mode (sys.flags attributo):        sys — System-specific parameters and functions.
                                                             (line  577)
* device_encoding() (nel modulo os):     File Descriptor Operations.
                                                             (line   81)
* devmajor (tarfile.TarInfo attributo):  TarInfo Objects.    (line  141)
* devminor (tarfile.TarInfo attributo):  TarInfo Objects.    (line  145)
* devnull (nel modulo os):               Miscellaneous System Information.
                                                             (line  159)
* DEVNULL (nel modulo subprocess):       Using the subprocess Module.
                                                             (line  142)
* devpoll() (nel modulo select):         select — Waiting for I/O completion.
                                                             (line   36)
* DevpollSelector (classe in selectors): Classes<3>.         (line  184)
* dfast (compression.zstd.Strategy attributo): Advanced parameter control.
                                                             (line  311)
* dgettext() (nel modulo gettext):       GNU gettext API.    (line   39)
* dgettext() (nel modulo locale):        Access to message catalogs.
                                                             (line    8)
* Dialect (classe in csv):               Module Contents<3>. (line  188)
* dialect (csv.csvreader attributo):     Reader Objects.     (line   19)
* dialect (csv.csvwriter attributo):     Writer Objects.     (line   33)
* Dialog (classe in tkinter.commondialog): tkinter commondialog — Dialog window templates.
                                                             (line   14)
* Dialog (classe in tkinter.simpledialog): tkinter simpledialog — Standard Tkinter input dialogs.
                                                             (line   21)
* dict (classe built-in):                Tipi di Mapping — dict.
                                                             (line   20)
* Dict (classe in ast):                  Literals<3>.        (line  167)
* Dict (classe in typing):               Aliases to built-in types.
                                                             (line    6)
* dict_content (compression.zstd.ZstdDict attributo): Zstandard dictionaries.
                                                             (line  121)
* dict_id (compression.zstd.ZstdDict attributo): Zstandard dictionaries.
                                                             (line  128)
* dict_id_flag (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  215)
* DICT_MERGE (opcode):                   Python Bytecode Instructions.
                                                             (line  765)
* DICT_UPDATE (opcode):                  Python Bytecode Instructions.
                                                             (line  754)
* dict() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  224)
* DictComp (classe in ast):              Comprehensions.     (line    6)
* dictConfig() (nel modulo logging.config): Configuration functions.
                                                             (line   13)
* dictionary:                            Glossary.           (line  502)
* dictionary comprehension:              Glossary.           (line  508)
* dictionary view:                       Glossary.           (line  516)
* dictionary_id (compression.zstd.FrameInfo attributo): Miscellaneous<2>.
                                                             (line   20)
* dictionary;comprehensions:             Dictionary displays.
                                                             (line    6)
* dictionary;display:                    Dictionary displays.
                                                             (line    6)
* DictReader (classe in csv):            Module Contents<3>. (line  105)
* DictWriter (classe in csv):            Module Contents<3>. (line  152)
* diff_bytes() (nel modulo difflib):     difflib — Helpers for computing deltas.
                                                             (line  337)
* diff_files (filecmp.dircmp attributo): The dircmp class.   (line   94)
* Differ (classe in difflib):            difflib — Helpers for computing deltas.
                                                             (line   50)
* difference_update() (set metodo):      Tipi di Insiemi — set frozenset.
                                                             (line  194)
* difference() (frozenset metodo):       Tipi di Insiemi — set frozenset.
                                                             (line  118)
* difference() (set metodo):             Tipi di Insiemi — set frozenset.
                                                             (line  118)
* dig (sys.float_info attributo):        sys — System-specific parameters and functions.
                                                             (line  659)
* digest_size (hmac.HMAC attributo):     hmac — Keyed-Hashing for Message Authentication.
                                                             (line   94)
* digest() (hashlib.hash metodo):        Hash Objects.       (line   38)
* digest() (hashlib.shake metodo):       SHAKE variable length digests.
                                                             (line   15)
* digest() (hmac.HMAC metodo):           hmac — Keyed-Hashing for Message Authentication.
                                                             (line   60)
* digest() (nel modulo hmac):            hmac — Keyed-Hashing for Message Authentication.
                                                             (line   33)
* digit() (nel modulo unicodedata):      unicodedata — Unicode Database.
                                                             (line   62)
* digits (nel modulo string):            String constants.   (line   24)
* dimensione buffer, I/O:                Funzioni Incorporate.
                                                             (line 1539)
* dir() (ftplib.FTP metodo):             FTP objects.        (line  312)
* dircmp (classe in filecmp):            The dircmp class.   (line    6)
* Directory (classe in tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line   71)
* directory;changing:                    Files and Directories.
                                                             (line  118)
* directory;creating:                    Files and Directories.
                                                             (line  548)
* directory;deleting:                    Directory and files operations.
                                                             (line  286)
* directory;deleting <1>:                Files and Directories.
                                                             (line  738)
* directory;traversal:                   Files and Directories.
                                                             (line 1655)
* directory;traversal <1>:               Files and Directories.
                                                             (line 1756)
* directory;walking:                     Files and Directories.
                                                             (line 1655)
* directory;walking <1>:                 Files and Directories.
                                                             (line 1756)
* DirEntry (classe in os):               Files and Directories.
                                                             (line  919)
* dirname() (nel modulo os.path):        os path — Common pathname manipulations.
                                                             (line  107)
* dirs_double_event() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line   86)
* dirs_select_event() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line   90)
* DirsOnSysPath (classe in test.support.import_helper): test support import_helper — Utilities for import tests.
                                                             (line   97)
* DIRTYPE (nel modulo tarfile):          tarfile — Read and write tar archive files.
                                                             (line  345)
* dis command line option; -C:           Command-line interface<12>.
                                                             (line   17)
* dis command line option; -h:           Command-line interface<12>.
                                                             (line   13)
* dis command line option; -help:        Command-line interface<12>.
                                                             (line   13)
* dis command line option; -O:           Command-line interface<12>.
                                                             (line   23)
* dis command line option; -P:           Command-line interface<12>.
                                                             (line   29)
* dis command line option; -S:           Command-line interface<12>.
                                                             (line   35)
* dis command line option; -show-caches: Command-line interface<12>.
                                                             (line   17)
* dis command line option; -show-offsets: Command-line interface<12>.
                                                             (line   23)
* dis command line option; -show-positions: Command-line interface<12>.
                                                             (line   29)
* dis command line option; -specialized: Command-line interface<12>.
                                                             (line   35)
* dis() (dis.Bytecode metodo):           Bytecode analysis.  (line   62)
* dis() (nel modulo dis):                Analysis functions. (line   40)
* dis() (nel modulo pickletools):        Programmatic interface.
                                                             (line    6)
* DISABLE (nel modulo sys.monitoring):   Disabling events.   (line    6)
* disable (pdb command):                 Debugger commands.  (line  142)
* disable_current_event() (bdb.Bdb metodo): bdb — Debugger framework.
                                                             (line  432)
* disable_faulthandler() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  374)
* disable_gc() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  386)
* disable_interspersed_args() (optparse.OptionParser metodo): Querying and manipulating your option parser.
                                                             (line   10)
* disable() (bdb.Breakpoint metodo):     bdb — Debugger framework.
                                                             (line   52)
* disable() (nel modulo faulthandler):   Fault handler state.
                                                             (line   37)
* disable() (nel modulo gc):             gc — Garbage Collector interface.
                                                             (line   26)
* disable() (nel modulo logging):        Module-Level Functions.
                                                             (line  105)
* disable() (profile.Profile metodo):    profile and cProfile Module Reference.
                                                             (line   82)
* disabled (logging.Logger attributo):   Logger Objects.     (line   97)
* DisableReflectionKey() (nel modulo winreg): Functions<13>. (line  482)
* disassemble() (nel modulo dis):        Analysis functions. (line  104)
* discard (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   58)
* discard() (mailbox.Mailbox metodo):    Mailbox objects.    (line   77)
* discard() (mailbox.MH metodo):         MH objects.         (line   79)
* discard() (set metodo):                Tipi di Insiemi — set frozenset.
                                                             (line  216)
* disco() (nel modulo dis):              Analysis functions. (line  104)
* discover() (unittest.TestLoader metodo): Loading and running tests.
                                                             (line  117)
* disk_usage() (nel modulo shutil):      Directory and files operations.
                                                             (line  400)
* dispatch_call() (bdb.Bdb metodo):      bdb — Debugger framework.
                                                             (line  237)
* dispatch_exception() (bdb.Bdb metodo): bdb — Debugger framework.
                                                             (line  257)
* dispatch_line() (bdb.Bdb metodo):      bdb — Debugger framework.
                                                             (line  227)
* dispatch_return() (bdb.Bdb metodo):    bdb — Debugger framework.
                                                             (line  247)
* dispatch_table (pickle.Pickler attributo): Module Interface.
                                                             (line  186)
* DISPLAY:                               Tkinter Modules.    (line   27)
* display (pdb command):                 Debugger commands.  (line  302)
* display_name (email.headerregistry.Address attributo): email headerregistry Custom Header Objects.
                                                             (line  426)
* display_name (email.headerregistry.Group attributo): email headerregistry Custom Header Objects.
                                                             (line  471)
* displayhook() (nel modulo sys):        sys — System-specific parameters and functions.
                                                             (line  299)
* dist() (nel modulo math):              Summation and product functions.
                                                             (line    6)
* distance() (nel modulo turtle):        Tell Turtle’s state.
                                                             (line   68)
* distb() (nel modulo dis):              Analysis functions. (line   85)
* Distribution (classe in importlib.metadata): Distributions.
                                                             (line   14)
* distribution() (nel modulo importlib.metadata): Distributions.
                                                             (line    6)
* Div (classe in ast):                   Expressions<2>.     (line   53)
* divide_int() (decimal.Context metodo): Context objects.    (line  315)
* divide() (decimal.Context metodo):     Context objects.    (line  311)
* division:                              Binary arithmetic operations.
                                                             (line   37)
* division (nel modulo __future__):      Module Contents<5>. (line   22)
* DivisionByZero (classe in decimal):    Signals.            (line   34)
* divmod() (decimal.Context metodo):     Context objects.    (line  319)
* DLE (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   73)
* DllCanUnloadNow() (nel modulo ctypes): Utility functions.  (line  113)
* DllGetClassObject() (nel modulo ctypes): Utility functions.
                                                             (line  121)
* dllhandle (nel modulo sys):            sys — System-specific parameters and functions.
                                                             (line  293)
* dllist() (nel modulo ctypes.util):     Utility functions.  (line  153)
* dnd_start() (nel modulo tkinter.dnd):  tkinter dnd — Drag and drop support.
                                                             (line   65)
* DndHandler (classe in tkinter.dnd):    tkinter dnd — Drag and drop support.
                                                             (line   43)
* dngettext() (nel modulo gettext):      GNU gettext API.    (line   58)
* dnpgettext() (nel modulo gettext):     GNU gettext API.    (line   69)
* do_clear() (bdb.Bdb metodo):           bdb — Debugger framework.
                                                             (line  320)
* do_command() (curses.textpad.Textbox metodo): Textbox objects.
                                                             (line   30)
* do_GET() (http.server.SimpleHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  433)
* do_handshake() (ssl.SSLSocket metodo): SSL Sockets.        (line  126)
* do_HEAD() (http.server.SimpleHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  426)
* do_help() (cmd.Cmd metodo):            Cmd Objects.        (line   49)
* do_POST() (http.server.CGIHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  521)
* doc (json.JSONDecodeError attributo):  Exceptions<19>.     (line   15)
* doc (tomllib.TOMLDecodeError attributo): tomllib — Parse TOML files.
                                                             (line   69)
* doc_header (cmd.Cmd attributo):        Cmd Objects.        (line  155)
* DocCGIXMLRPCRequestHandler (classe in xmlrpc.server): Documenting XMLRPC server.
                                                             (line   23)
* DocFileSuite() (nel modulo doctest):   Unittest API.       (line   24)
* doClassCleanups() (unittest.TestCase metodo della classe): Test cases.
                                                             (line  900)
* doCleanups() (unittest.TestCase metodo): Test cases.       (line  858)
* docmd() (smtplib.SMTP metodo):         SMTP Objects.       (line   17)
* docstring:                             Class definitions.  (line    6)
* docstring <1>:                         Glossary.           (line  526)
* docstring (doctest.DocTest attributo): DocTest Objects.    (line   49)
* docstrings:                            Definizione di Funzioni.
                                                             (line   21)
* docstrings <1>:                        Stringhe di Documentazione.
                                                             (line    6)
* DocTest (classe in doctest):           DocTest Objects.    (line    6)
* doctest command line option; -f:       Command-line Usage. (line   35)
* doctest command line option; -fail-fast: Command-line Usage.
                                                             (line   35)
* doctest command line option; -o:       Command-line Usage. (line   28)
* doctest command line option; -option:  Command-line Usage. (line   28)
* doctest command line option; -v:       Command-line Usage. (line   11)
* doctest command line option; -verbose: Command-line Usage. (line   11)
* DocTestFailure:                        Debugging.          (line  186)
* DocTestFinder (classe in doctest):     DocTestFinder objects.
                                                             (line    6)
* DocTestParser (classe in doctest):     DocTestParser objects.
                                                             (line    6)
* DocTestRunner (classe in doctest):     DocTestRunner objects.
                                                             (line    6)
* DocTestSuite() (nel modulo doctest):   Unittest API.       (line  100)
* doctype() (xml.etree.ElementTree.TreeBuilder metodo): TreeBuilder Objects.
                                                             (line   67)
* documentation string:                  Special read-only attributes<2>.
                                                             (line  104)
* documentation;generation:              pydoc — Documentation generator and online help system.
                                                             (line    8)
* documentation;online:                  pydoc — Documentation generator and online help system.
                                                             (line    8)
* documentElement (xml.dom.Document attributo): Document Objects.
                                                             (line   10)
* DocXMLRPCRequestHandler (classe in xmlrpc.server): Documenting XMLRPC server.
                                                             (line   28)
* DocXMLRPCServer (classe in xmlrpc.server): Documenting XMLRPC server.
                                                             (line   11)
* does_esmtp (smtplib.SMTP attributo):   SMTP Objects.       (line  361)
* domain (email.headerregistry.Address attributo): email headerregistry Custom Header Objects.
                                                             (line  437)
* domain (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   41)
* domain (http.cookies.Morsel attributo): Morsel Objects.    (line   13)
* domain (tracemalloc.DomainFilter attributo): DomainFilter. (line   20)
* domain (tracemalloc.Filter attributo): Filter.             (line   32)
* domain (tracemalloc.Trace attributo):  Trace.              (line   16)
* domain_initial_dot (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   90)
* domain_return_ok() (http.cookiejar.CookiePolicy metodo): CookiePolicy Objects.
                                                             (line   27)
* domain_specified (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   86)
* DomainFilter (classe in tracemalloc):  DomainFilter.       (line    6)
* DomainLiberal (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line  156)
* DomainRFC2965Match (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line  149)
* DomainStrict (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line  161)
* DomainStrictNoDots (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line  136)
* DomainStrictNonDomain (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line  142)
* DOMEventStream (classe in xml.dom.pulldom): DOMEventStream Objects.
                                                             (line    6)
* DOMException:                          Exceptions<22>.     (line   18)
* doModuleCleanups() (nel modulo unittest): setUpModule and tearDownModule.
                                                             (line   45)
* DomstringSizeErr:                      Exceptions<22>.     (line   23)
* done() (asyncio.Future metodo):        Future Object.      (line   63)
* done() (asyncio.Task metodo):          Task Object.        (line   66)
* done() (concurrent.futures.Future metodo): Future Objects. (line   32)
* done() (graphlib.TopologicalSorter metodo): graphlib — Functionality to operate with graph-like structures.
                                                             (line  143)
* done() (nel modulo turtle):            Using screen events.
                                                             (line  106)
* DONT_ACCEPT_BLANKLINE (nel modulo doctest): Option Flags.  (line   28)
* DONT_ACCEPT_TRUE_FOR_1 (nel modulo doctest): Option Flags. (line   16)
* dont_write_bytecode (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line  335)
* dont_write_bytecode (sys.flags attributo): sys — System-specific parameters and functions.
                                                             (line  553)
* doRollover() (logging.handlers.RotatingFileHandler metodo): RotatingFileHandler.
                                                             (line   43)
* doRollover() (logging.handlers.TimedRotatingFileHandler metodo): TimedRotatingFileHandler.
                                                             (line  106)
* DOT (nel modulo token):                token — Constants used with Python parse trees.
                                                             (line  260)
* dot() (nel modulo turtle):             Turtle motion.      (line  252)
* DOTALL (nel modulo re):                Flags.              (line  108)
* doublequote (csv.Dialect attributo):   Dialects and Formatting Parameters.
                                                             (line   24)
* DOUBLESLASH (nel modulo token):        token — Constants used with Python parse trees.
                                                             (line  332)
* DOUBLESLASHEQUAL (nel modulo token):   token — Constants used with Python parse trees.
                                                             (line  335)
* DOUBLESTAR (nel modulo token):         token — Constants used with Python parse trees.
                                                             (line  296)
* DOUBLESTAREQUAL (nel modulo token):    token — Constants used with Python parse trees.
                                                             (line  329)
* doupdate() (nel modulo curses):        Functions<5>.       (line  104)
* down (pdb command):                    Debugger commands.  (line   96)
* down() (nel modulo turtle):            Drawing state.      (line    6)
* dpgettext() (nel modulo gettext):      GNU gettext API.    (line   65)
* drain() (asyncio.StreamWriter metodo): StreamWriter.       (line   69)
* drive (pathlib.PurePath attributo):    Methods and properties.
                                                             (line   15)
* drop_whitespace (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  207)
* dropwhile() (nel modulo itertools):    Itertool Functions. (line  270)
* dst() (datetime.datetime metodo):      datetime Objects.   (line  538)
* dst() (datetime.time metodo):          time Objects.       (line  263)
* dst() (datetime.timezone metodo):      timezone Objects.   (line   57)
* dst() (datetime.tzinfo metodo):        tzinfo Objects.     (line   65)
* DTDHandler (classe in xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line   24)
* duck-typing:                           Glossary.           (line  535)
* dump_c_stack() (nel modulo faulthandler): Dumping the C stack.
                                                             (line    8)
* dump_stats() (profile.Profile metodo): profile and cProfile Module Reference.
                                                             (line  104)
* dump_stats() (pstats.Stats metodo):    The Stats Class.    (line   59)
* dump_traceback_later() (nel modulo faulthandler): Dumping the tracebacks after a timeout.
                                                             (line    6)
* dump_traceback() (nel modulo faulthandler): Dumping the traceback.
                                                             (line    6)
* dump() (nel modulo ast):               ast helpers.        (line  269)
* dump() (nel modulo json):              Basic Usage.        (line    6)
* dump() (nel modulo marshal):           marshal — Internal Python object serialization.
                                                             (line   72)
* dump() (nel modulo pickle):            Module Interface.   (line   39)
* dump() (nel modulo plistlib):          plistlib — Generate and parse Apple plist files.
                                                             (line   93)
* dump() (nel modulo xml.etree.ElementTree): Functions<8>.   (line   86)
* dump() (pickle.Pickler metodo):        Module Interface.   (line  162)
* dump() (tracemalloc.Snapshot metodo):  Snapshot.           (line   29)
* dumps() (nel modulo json):             Basic Usage.        (line   93)
* dumps() (nel modulo marshal):          marshal — Internal Python object serialization.
                                                             (line  114)
* dumps() (nel modulo pickle):           Module Interface.   (line   52)
* dumps() (nel modulo plistlib):         plistlib — Generate and parse Apple plist files.
                                                             (line  130)
* dumps() (nel modulo xmlrpc.client):    Convenience Functions.
                                                             (line    6)
* dunder:                                Glossary.           (line  548)
* dup() (nel modulo os):                 File Descriptor Operations.
                                                             (line   93)
* dup() (socket.socket metodo):          Socket Objects.     (line  109)
* dup2() (nel modulo os):                File Descriptor Operations.
                                                             (line  107)
* DuplicateOptionError:                  Exceptions<8>.      (line   24)
* DuplicateSectionError:                 Exceptions<8>.      (line   14)
* dwFlags (subprocess.STARTUPINFO attributo): Windows Popen Helpers.
                                                             (line   20)
* DynamicClassAttribute() (nel modulo types): Additional Utility Classes and Functions.
                                                             (line   55)
* e (nel modulo cmath):                  Constants<3>.       (line   10)
* e (nel modulo math):                   Constants<2>.       (line   10)
* e;in numeric literal:                  Integer literals.   (line   65)
* E2BIG (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line   54)
* EACCES (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line   80)
* EADDRINUSE (nel modulo errno):         errno — Standard errno system symbols.
                                                             (line  432)
* EADDRNOTAVAIL (nel modulo errno):      errno — Standard errno system symbols.
                                                             (line  436)
* EADV (nel modulo errno):               errno — Standard errno system symbols.
                                                             (line  306)
* EAFNOSUPPORT (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  428)
* EAFP:                                  Glossary.           (line  554)
* EAGAIN (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line   71)
* eager_task_factory() (nel modulo asyncio): Eager Task Factory.
                                                             (line    6)
* EALREADY (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  507)
* east_asian_width() (nel modulo unicodedata): unicodedata — Unicode Database.
                                                             (line  108)
* EAUTH (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  587)
* EBADARCH (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  593)
* EBADE (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  242)
* EBADEXEC (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  599)
* EBADF (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line   62)
* EBADFD (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  342)
* EBADMACHO (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  605)
* EBADMSG (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  330)
* EBADR (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  246)
* EBADRPC (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  671)
* EBADRQC (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  258)
* EBADSLT (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  262)
* EBFONT (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  270)
* EBUSY (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line   93)
* ECANCELED (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  698)
* ECHILD (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line   66)
* echo() (nel modulo curses):            Functions<5>.       (line  120)
* echochar() (curses.window metodo):     Window Objects.     (line  198)
* ECHRNG (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  210)
* ECOMM (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  314)
* ECONNABORTED (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  452)
* ECONNREFUSED (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  488)
* ECONNRESET (nel modulo errno):         errno — Standard errno system symbols.
                                                             (line  457)
* EDEADLK (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  173)
* EDEADLOCK (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  266)
* EDESTADDRREQ (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  390)
* EDEVERR (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  611)
* edit() (curses.textpad.Textbox metodo): Textbox objects.   (line   19)
* EDOM (nel modulo errno):               errno — Standard errno system symbols.
                                                             (line  165)
* EDOTDOT (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  326)
* EDQUOT (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  541)
* EEXIST (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line   97)
* EFAULT (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line   85)
* EFBIG (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  140)
* EFD_CLOEXEC (nel modulo os):           Files and Directories.
                                                             (line 1931)
* EFD_NONBLOCK (nel modulo os):          Files and Directories.
                                                             (line 1940)
* EFD_SEMAPHORE (nel modulo os):         Files and Directories.
                                                             (line 1949)
* effective() (nel modulo bdb):          bdb — Debugger framework.
                                                             (line  514)
* EFTYPE (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  617)
* ehlo_or_helo_if_needed() (smtplib.SMTP metodo): SMTP Objects.
                                                             (line   75)
* ehlo_resp (smtplib.SMTP attributo):    SMTP Objects.       (line  357)
* ehlo() (smtplib.SMTP metodo):          SMTP Objects.       (line   58)
* EHOSTDOWN (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  493)
* EHOSTUNREACH (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  497)
* EHWPOISON (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  501)
* EIDRM (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  206)
* EILSEQ (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  370)
* EINPROGRESS (nel modulo errno):        errno — Standard errno system symbols.
                                                             (line  512)
* EINTR (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line   41)
* EINVAL (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  120)
* EIO (nel modulo errno):                errno — Standard errno system symbols.
                                                             (line   46)
* EISCONN (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  466)
* EISDIR (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  115)
* EISNAM (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  533)
* EJECT (enum.FlagBoundary attributo):   Data Types<2>.      (line  708)
* EKEYEXPIRED (nel modulo errno):        errno — Standard errno system symbols.
                                                             (line  563)
* EKEYREJECTED (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  571)
* EKEYREVOKED (nel modulo errno):        errno — Standard errno system symbols.
                                                             (line  567)
* EL2HLT (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  238)
* EL2NSYNC (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  214)
* EL3HLT (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  218)
* EL3RST (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  222)
* Element (classe in xml.etree.ElementTree): Element Objects.
                                                             (line    6)
* element_create() (tkinter.ttk.Style metodo): Ttk Styling.  (line  131)
* element_names() (tkinter.ttk.Style metodo): Ttk Styling.   (line  252)
* element_options() (tkinter.ttk.Style metodo): Ttk Styling. (line  256)
* ElementDeclHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  290)
* elements() (collections.Counter metodo): Counter objects.  (line   67)
* ElementTree (classe in xml.etree.ElementTree): ElementTree Objects.
                                                             (line    6)
* ELIBACC (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  350)
* ELIBBAD (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  354)
* ELIBEXEC (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  366)
* ELIBMAX (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  362)
* ELIBSCN (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  358)
* ELLIPSIS (nel modulo doctest):         Option Flags.       (line   47)
* ELLIPSIS (nel modulo token):           token — Constants used with Python parse trees.
                                                             (line  347)
* Ellipsis (variabile built-in):         Built-in Constants. (line   62)
* EllipsisType (nel modulo types):       Standard Interpreter Types.
                                                             (line  144)
* ELNRNG (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  226)
* ELOCKUNMAPPED (nel modulo errno):      errno — Standard errno system symbols.
                                                             (line  579)
* ELOOP (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  193)
* else;conditional expression:           Conditional expressions.
                                                             (line    6)
* EM (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line  100)
* EmailMessage (classe in email.message): email message Representing an email message.
                                                             (line   52)
* EmailPolicy (classe in email.policy):  email policy Policy Objects.
                                                             (line  360)
* Emax (decimal.Context attributo):      Context objects.    (line  148)
* EMEDIUMTYPE (nel modulo errno):        errno — Standard errno system symbols.
                                                             (line  555)
* EMFILE (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  128)
* Emin (decimal.Context attributo):      Context objects.    (line  148)
* emit() (logging.FileHandler metodo):   FileHandler.        (line   31)
* emit() (logging.Handler metodo):       Handler Objects.    (line  109)
* emit() (logging.handlers.BufferingHandler metodo): MemoryHandler.
                                                             (line   24)
* emit() (logging.handlers.DatagramHandler metodo): DatagramHandler.
                                                             (line   29)
* emit() (logging.handlers.HTTPHandler metodo): HTTPHandler. (line   36)
* emit() (logging.handlers.NTEventLogHandler metodo): NTEventLogHandler.
                                                             (line   38)
* emit() (logging.handlers.QueueHandler metodo): QueueHandler.
                                                             (line   43)
* emit() (logging.handlers.RotatingFileHandler metodo): RotatingFileHandler.
                                                             (line   47)
* emit() (logging.handlers.SMTPHandler metodo): SMTPHandler. (line   35)
* emit() (logging.handlers.SocketHandler metodo): SocketHandler.
                                                             (line   24)
* emit() (logging.handlers.SysLogHandler metodo): SysLogHandler.
                                                             (line   67)
* emit() (logging.handlers.TimedRotatingFileHandler metodo): TimedRotatingFileHandler.
                                                             (line  110)
* emit() (logging.handlers.WatchedFileHandler metodo): WatchedFileHandler.
                                                             (line   50)
* emit() (logging.NullHandler metodo):   NullHandler.        (line   16)
* emit() (logging.StreamHandler metodo): StreamHandler.      (line   17)
* EMLINK (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  156)
* Empty:                                 queue — A synchronized queue class.
                                                             (line   82)
* empty (inspect.Parameter attributo):   Introspecting callables with the Signature object.
                                                             (line  219)
* empty (inspect.Signature attributo):   Introspecting callables with the Signature object.
                                                             (line  109)
* EMPTY_NAMESPACE (nel modulo xml.dom):  Module Contents<4>. (line   35)
* empty;list:                            List displays.      (line    6)
* empty;tuple:                           Immutable sequences.
                                                             (line   29)
* empty;tuple <1>:                       Parenthesized forms.
                                                             (line   16)
* empty() (asyncio.Queue metodo):        Queue.              (line   27)
* empty() (multiprocessing.Queue metodo): Pipes and Queues.  (line  120)
* empty() (multiprocessing.SimpleQueue metodo): Pipes and Queues.
                                                             (line  242)
* empty() (queue.Queue metodo):          Queue Objects.      (line   15)
* empty() (queue.SimpleQueue metodo):    SimpleQueue Objects.
                                                             (line   14)
* empty() (sched.scheduler metodo):      Scheduler Objects.  (line   47)
* emptyline() (cmd.Cmd metodo):          Cmd Objects.        (line   70)
* emscripten_version (sys._emscripten_info attributo): sys — System-specific parameters and functions.
                                                             (line  349)
* EMSGSIZE (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  394)
* EMULTIHOP (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  322)
* enable (pdb command):                  Debugger commands.  (line  149)
* enable_callback_tracebacks() (nel modulo sqlite3): Module functions.
                                                             (line  125)
* enable_interspersed_args() (optparse.OptionParser metodo): Querying and manipulating your option parser.
                                                             (line   31)
* enable_load_extension() (sqlite3.Connection metodo): Connection objects.
                                                             (line  426)
* enable_long_distance_matching (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  132)
* enable_traversal() (tkinter.ttk.Notebook metodo): ttk Notebook.
                                                             (line   75)
* ENABLE_USER_SITE (nel modulo site):    Module contents<5>. (line   10)
* enable() (bdb.Breakpoint metodo):      bdb — Debugger framework.
                                                             (line   48)
* enable() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line   84)
* enable() (nel modulo faulthandler):    Fault handler state.
                                                             (line    6)
* enable() (nel modulo gc):              gc — Garbage Collector interface.
                                                             (line   22)
* enable() (profile.Profile metodo):     profile and cProfile Module Reference.
                                                             (line   78)
* EnableControlFlowGuard:                Build<42>.          (line   47)
* enabled (bdb.Breakpoint attributo):    bdb — Debugger framework.
                                                             (line  106)
* EnableReflectionKey() (nel modulo winreg): Functions<13>.  (line  500)
* ENAMETOOLONG (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  177)
* ENAVAIL (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  529)
* enclose() (curses.window metodo):      Window Objects.     (line  203)
* encode (codecs.CodecInfo attributo):   codecs — Codec registry and base classes.
                                                             (line   78)
* encode_7or8bit() (nel modulo email.encoders): email encoders Encoders.
                                                             (line   57)
* encode_base64() (nel modulo email.encoders): email encoders Encoders.
                                                             (line   49)
* encode_noop() (nel modulo email.encoders): email encoders Encoders.
                                                             (line   63)
* encode_quopri() (nel modulo email.encoders): email encoders Encoders.
                                                             (line   42)
* encode_rfc2231() (nel modulo email.utils): email utils Miscellaneous utilities.
                                                             (line  191)
* encode() (codecs.Codec metodo):        Stateless Encoding and Decoding.
                                                             (line   11)
* encode() (codecs.IncrementalEncoder metodo): IncrementalEncoder Objects.
                                                             (line   28)
* encode() (email.header.Header metodo): email header Internationalized headers.
                                                             (line  125)
* encode() (json.JSONEncoder metodo):    Encoders and Decoders.
                                                             (line  221)
* encode() (nel modulo base64):          Legacy Interface.   (line   21)
* encode() (nel modulo codecs):          codecs — Codec registry and base classes.
                                                             (line   23)
* encode() (nel modulo quopri):          quopri — Encode and decode MIME quoted-printable data.
                                                             (line   29)
* encode() (str metodo):                 Metodi per le Stringhe.
                                                             (line   92)
* encode() (xmlrpc.client.Binary metodo): Binary Objects.    (line   25)
* encode() (xmlrpc.client.DateTime metodo): DateTime Objects.
                                                             (line   17)
* encodebytes() (nel modulo base64):     Legacy Interface.   (line   31)
* EncodedFile() (nel modulo codecs):     codecs — Codec registry and base classes.
                                                             (line  215)
* encodePriority() (logging.handlers.SysLogHandler metodo): SysLogHandler.
                                                             (line  101)
* encodestring() (nel modulo quopri):    quopri — Encode and decode MIME quoted-printable data.
                                                             (line   46)
* encoding (curses.window attributo):    Window Objects.     (line  213)
* encoding (io.TextIOBase attributo):    Text I/O<2>.        (line   15)
* ENCODING (nel modulo tarfile):         tarfile — Read and write tar archive files.
                                                             (line  319)
* ENCODING (nel modulo token):           token — Constants used with Python parse trees.
                                                             (line  161)
* encoding (UnicodeError attributo):     Concrete exceptions.
                                                             (line  451)
* encoding declarations (source file):   Encoding declarations.
                                                             (line    6)
* encodings_map (mimetypes.MimeTypes attributo): MimeTypes objects.
                                                             (line   33)
* encodings_map (nel modulo mimetypes):  mimetypes — Map filenames to MIME types.
                                                             (line  153)
* EncodingWarning:                       Warnings.           (line   72)
* end (UnicodeError attributo):          Concrete exceptions.
                                                             (line  471)
* END_ASYNC_FOR (opcode):                Python Bytecode Instructions.
                                                             (line  347)
* end_col_offset (ast.AST attributo):    Node classes.       (line   50)
* end_colno (traceback.FrameSummary attributo): FrameSummary Objects.
                                                             (line   62)
* end_fill() (nel modulo turtle):        Filling.            (line   39)
* END_FOR (opcode):                      Python Bytecode Instructions.
                                                             (line  159)
* end_headers() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  322)
* end_lineno (ast.AST attributo):        Node classes.       (line   50)
* end_lineno (SyntaxError attributo):    Concrete exceptions.
                                                             (line  343)
* end_lineno (traceback.FrameSummary attributo): FrameSummary Objects.
                                                             (line   49)
* end_lineno (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line   99)
* end_ns() (xml.etree.ElementTree.TreeBuilder metodo): TreeBuilder Objects.
                                                             (line   86)
* end_offset (SyntaxError attributo):    Concrete exceptions.
                                                             (line  349)
* end_offset (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line  115)
* end_poly() (nel modulo turtle):        Special Turtle methods.
                                                             (line   23)
* END_SEND (opcode):                     Python Bytecode Instructions.
                                                             (line  166)
* end() (re.Match metodo):               Match Objects.      (line  147)
* end() (xml.etree.ElementTree.TreeBuilder metodo): TreeBuilder Objects.
                                                             (line   38)
* endCDATA() (xml.sax.handler.LexicalHandler metodo): LexicalHandler Objects.
                                                             (line   39)
* EndCdataSectionHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  397)
* EndDoctypeDeclHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  285)
* endDocument() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line   40)
* endDTD() (xml.sax.handler.LexicalHandler metodo): LexicalHandler Objects.
                                                             (line   28)
* endElement() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line   94)
* EndElementHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  320)
* endElementNS() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line  119)
* endheaders() (http.client.HTTPConnection metodo): HTTPConnection Objects.
                                                             (line  190)
* ENDMARKER (nel modulo token):          token — Constants used with Python parse trees.
                                                             (line  156)
* EndNamespaceDeclHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  376)
* endpos (re.Match attributo):           Match Objects.      (line  186)
* endPrefixMapping() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line   73)
* endswith() (bytearray metodo):         Operazioni su Bytes e Bytearray.
                                                             (line  126)
* endswith() (bytes metodo):             Operazioni su Bytes e Bytearray.
                                                             (line  126)
* endswith() (str metodo):               Metodi per le Stringhe.
                                                             (line  125)
* endwin() (nel modulo curses):          Functions<5>.       (line  125)
* ENEEDAUTH (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  623)
* ENETDOWN (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  440)
* ENETRESET (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  448)
* ENETUNREACH (nel modulo errno):        errno — Standard errno system symbols.
                                                             (line  444)
* ENFILE (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  124)
* ENOANO (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  254)
* ENOATTR (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  629)
* ENOBUFS (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  462)
* ENOCSI (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  234)
* ENODATA (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  278)
* ENODEV (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  106)
* ENOENT (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line   31)
* ENOEXEC (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line   58)
* ENOKEY (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  559)
* ENOLCK (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  181)
* ENOLINK (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  302)
* ENOMEDIUM (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  551)
* ENOMEM (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line   76)
* ENOMSG (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  202)
* ENONET (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  290)
* ENOPKG (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  294)
* ENOPOLICY (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  635)
* ENOPROTOOPT (nel modulo errno):        errno — Standard errno system symbols.
                                                             (line  402)
* ENOSPC (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  144)
* ENOSR (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  286)
* ENOSTR (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  274)
* ENOSYS (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  185)
* ENOTACTIVE (nel modulo errno):         errno — Standard errno system symbols.
                                                             (line  583)
* ENOTBLK (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line   89)
* ENOTCAPABLE (nel modulo errno):        errno — Standard errno system symbols.
                                                             (line  689)
* ENOTCONN (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  470)
* ENOTDIR (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  110)
* ENOTEMPTY (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  189)
* ENOTNAM (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  525)
* ENOTRECOVERABLE (nel modulo errno):    errno — Standard errno system symbols.
                                                             (line  710)
* ENOTSOCK (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  386)
* ENOTSUP (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  418)
* ENOTTY (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  132)
* ENOTUNIQ (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  338)
* ENQ (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   34)
* enqueue_sentinel() (logging.handlers.QueueListener metodo): QueueListener.
                                                             (line  100)
* enqueue() (logging.handlers.QueueHandler metodo): QueueHandler.
                                                             (line   86)
* ensure_directories() (venv.EnvBuilder metodo): API<2>.     (line   91)
* ensure_future() (nel modulo asyncio):  Future Functions.   (line   19)
* ensurepip command line option; -altinstall: Command-line interface<9>.
                                                             (line   42)
* ensurepip command line option; -default-pip: Command-line interface<9>.
                                                             (line   47)
* ensurepip command line option; -root:  Command-line interface<9>.
                                                             (line   25)
* ensurepip command line option; -user:  Command-line interface<9>.
                                                             (line   31)
* enter_async_context() (contextlib.AsyncExitStack metodo): Utilities.
                                                             (line  631)
* enter_context() (contextlib.ExitStack metodo): Utilities.  (line  546)
* enter() (sched.scheduler metodo):      Scheduler Objects.  (line   30)
* enterabs() (sched.scheduler metodo):   Scheduler Objects.  (line    9)
* enterAsyncContext() (unittest.IsolatedAsyncioTestCase metodo): Test cases.
                                                             (line  961)
* enterClassContext() (unittest.TestCase metodo della classe): Test cases.
                                                             (line  891)
* enterContext() (unittest.TestCase metodo): Test cases.     (line  849)
* enterModuleContext() (nel modulo unittest): setUpModule and tearDownModule.
                                                             (line   36)
* entities (xml.dom.DocumentType attributo): DocumentType Objects.
                                                             (line   38)
* EntityDeclHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  349)
* entitydefs (nel modulo html.entities): html entities — Definitions of HTML general entities.
                                                             (line   25)
* EntityResolver (classe in xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line   31)
* entry_points() (nel modulo importlib.metadata): Entry points.
                                                             (line    6)
* EntryPoint (classe in importlib.metadata): Entry points.   (line   26)
* EntryPoints (classe in importlib.metadata): Entry points.  (line   18)
* Enum (classe in enum):                 Data Types<2>.      (line  121)
* enum_certificates() (nel modulo ssl):  Certificate handling.
                                                             (line   87)
* enum_crls() (nel modulo ssl):          Certificate handling.
                                                             (line  110)
* EnumCheck (classe in enum):            Data Types<2>.      (line  612)
* EnumDict (classe in enum):             Data Types<2>.      (line  739)
* enumerate() (nel modulo threading):    Reference<2>.       (line   98)
* EnumKey() (nel modulo winreg):         Functions<13>.      (line  172)
* EnumType (classe in enum):             Data Types<2>.      (line    6)
* EnumValue() (nel modulo winreg):       Functions<13>.      (line  191)
* EnvBuilder (classe in venv):           API<2>.             (line   11)
* environ (nel modulo os):               Process Parameters. (line   16)
* environ (nel modulo posix):            Notable Module Contents.
                                                             (line    9)
* environb (nel modulo os):              Process Parameters. (line   63)
* environment:                           Resolution of names.
                                                             (line   12)
* environment variables;deleting:        Process Parameters. (line  611)
* environment variables;setting:         Process Parameters. (line  377)
* EnvironmentError:                      Concrete exceptions.
                                                             (line  511)
* Environments;virtual:                  venv — Creation of virtual environments.
                                                             (line   10)
* EnvironmentVarGuard (classe in test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   49)
* ENXIO (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line   50)
* eof (bz2.BZ2Decompressor attributo):   Incremental de compression.
                                                             (line   72)
* eof (compression.zstd.ZstdDecompressor attributo): Compressing and decompressing data in memory.
                                                             (line  211)
* eof (lzma.LZMADecompressor attributo): Compressing and decompressing data in memory<2>.
                                                             (line  165)
* eof (shlex.shlex attributo):           shlex Objects.      (line  178)
* eof (ssl.MemoryBIO attributo):         Memory BIO Support<2>.
                                                             (line  143)
* eof (zlib.Decompress attributo):       zlib — Compression compatible with gzip.
                                                             (line  253)
* eof_received() (asyncio.BufferedProtocol metodo): Buffered Streaming Protocols.
                                                             (line   40)
* eof_received() (asyncio.Protocol metodo): Streaming Protocols.
                                                             (line   30)
* EOFError:                              Concrete exceptions.
                                                             (line   33)
* EOFError (built-in exception):         File Objects.       (line   44)
* EOPNOTSUPP (nel modulo errno):         errno — Standard errno system symbols.
                                                             (line  414)
* EOT (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   31)
* EOVERFLOW (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  334)
* EOWNERDEAD (nel modulo errno):         errno — Standard errno system symbols.
                                                             (line  704)
* EPERM (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line   26)
* EPFNOSUPPORT (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  424)
* epilogue (email.message.EmailMessage attributo): email message Representing an email message.
                                                             (line  704)
* epilogue (email.message.Message attributo): email message Message Representing an email message using the compat32 API.
                                                             (line  718)
* EPIPE (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  160)
* epoch:                                 time — Time access and conversions.
                                                             (line   20)
* epoll() (nel modulo select):           select — Waiting for I/O completion.
                                                             (line   55)
* EpollSelector (classe in selectors):   Classes<3>.         (line  175)
* EPROCLIM (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  641)
* EPROCUNAVAIL (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  647)
* EPROGMISMATCH (nel modulo errno):      errno — Standard errno system symbols.
                                                             (line  653)
* EPROGUNAVAIL (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  659)
* EPROTO (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  318)
* EPROTONOSUPPORT (nel modulo errno):    errno — Standard errno system symbols.
                                                             (line  406)
* EPROTOTYPE (nel modulo errno):         errno — Standard errno system symbols.
                                                             (line  398)
* epsilon (sys.float_info attributo):    sys — System-specific parameters and functions.
                                                             (line  652)
* EPWROFF (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  665)
* Eq (classe in ast):                    Expressions<2>.     (line  108)
* eq() (nel modulo operator):            operator — Standard operators as functions.
                                                             (line   24)
* EQEQUAL (nel modulo token):            token — Constants used with Python parse trees.
                                                             (line  272)
* EQFULL (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  545)
* EQUAL (nel modulo token):              token — Constants used with Python parse trees.
                                                             (line  257)
* ERA (nel modulo locale):               locale — Internationalization services.
                                                             (line  313)
* ERA_D_FMT (nel modulo locale):         locale — Internationalization services.
                                                             (line  335)
* ERA_D_T_FMT (nel modulo locale):       locale — Internationalization services.
                                                             (line  330)
* ERA_T_FMT (nel modulo locale):         locale — Internationalization services.
                                                             (line  340)
* ERANGE (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  169)
* erase() (curses.window metodo):        Window Objects.     (line  223)
* erasechar() (nel modulo curses):       Functions<5>.       (line  129)
* EREMCHG (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  346)
* EREMOTE (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  298)
* EREMOTEIO (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  537)
* ERESTART (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  374)
* erf() (nel modulo math):               Special functions.  (line    6)
* erfc() (nel modulo math):              Special functions.  (line   20)
* ERFKILL (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  575)
* EROFS (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  152)
* ERPCMISMATCH (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  677)
* ERR (nel modulo curses):               Constants<6>.       (line    8)
* errcheck (ctypes._CFuncPtr attributo): Foreign functions.  (line   70)
* errcode (xmlrpc.client.ProtocolError attributo): ProtocolError Objects.
                                                             (line   17)
* errmsg (xmlrpc.client.ProtocolError attributo): ProtocolError Objects.
                                                             (line   21)
* errno (OSError attributo):             Concrete exceptions.
                                                             (line  173)
* error:                                 Functions and Exceptions.
                                                             (line    8)
* Error:                                 copy — Shallow and deep copy operations.
                                                             (line   33)
* Error <1>:                             Directory and files operations.
                                                             (line  493)
* error <1>:                             dbm — Interfaces to Unix «databases».
                                                             (line   22)
* error <2>:                             dbm gnu — GNU database manager.
                                                             (line   22)
* error <3>:                             dbm ndbm — New Database Manager.
                                                             (line   28)
* error <4>:                             dbm dumb — Portable DBM implementation.
                                                             (line   23)
* Error <2>:                             Exceptions<6>.      (line   15)
* error <5>:                             zlib — Compression compatible with gzip.
                                                             (line   25)
* Error <3>:                             Module Contents<3>. (line  336)
* Error <4>:                             Exceptions<8>.      (line    6)
* error <6>:                             os — Miscellaneous operating system interfaces.
                                                             (line   51)
* error <7>:                             Functions<5>.       (line    8)
* error <8>:                             _thread — Low-level threading API.
                                                             (line   21)
* error <9>:                             Exceptions<17>.     (line    6)
* error <10>:                            select — Waiting for I/O completion.
                                                             (line   29)
* Error <5>:                             Exceptions<20>.     (line    8)
* Error <6>:                             binascii — Convert between binary and ASCII.
                                                             (line  157)
* error <11>:                            xml parsers expat — Fast XML parsing using Expat.
                                                             (line   30)
* Error <7>:                             Command-line interface<6>.
                                                             (line   26)
* Error <8>:                             wave — Read and write WAV files.
                                                             (line   52)
* Error <9>:                             locale — Internationalization services.
                                                             (line   22)
* error <12>:                            resource — Resource usage information.
                                                             (line   19)
* error <13>:                            getopt — C-style parser for command line options.
                                                             (line  108)
* ERROR (nel modulo logging):            Logging Levels.     (line   40)
* ERROR (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  192)
* error handling:                        Exceptions.         (line    6)
* error_body (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  266)
* error_content_type (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  204)
* error_headers (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  259)
* error_leader() (shlex.shlex metodo):   shlex Objects.      (line   69)
* error_message_format (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  196)
* error_output() (wsgiref.handlers.BaseHandler metodo): wsgiref handlers – server/gateway base classes.
                                                             (line  229)
* error_perm:                            Module variables.   (line   16)
* error_proto:                           Module variables.   (line   21)
* error_proto <1>:                       poplib — POP3 protocol client.
                                                             (line   89)
* error_received() (asyncio.DatagramProtocol metodo): Datagram Protocols.
                                                             (line   15)
* error_reply:                           Module variables.   (line    6)
* error_status (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  253)
* error_temp:                            Module variables.   (line   11)
* error() (argparse.ArgumentParser metodo): Exiting methods. (line   19)
* error() (logging.Logger metodo):       Logger Objects.     (line  304)
* error() (nel modulo logging):          Module-Level Functions.
                                                             (line   80)
* error() (urllib.request.OpenerDirector metodo): OpenerDirector Objects.
                                                             (line   58)
* error() (xml.sax.handler.ErrorHandler metodo): ErrorHandler Objects.
                                                             (line   16)
* ErrorByteIndex (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  220)
* errorcode (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line   13)
* ErrorCode (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  224)
* ErrorColumnNumber (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  230)
* ErrorHandler (classe in xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line   38)
* errorlevel (tarfile.TarFile attributo): TarFile Objects.   (line  225)
* ErrorLineNumber (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  234)
* errors:                                Exceptions.         (line    6)
* errors (io.TextIOBase attributo):      Text I/O<2>.        (line   20)
* errors (unittest.TestLoader attributo): Loading and running tests.
                                                             (line   17)
* errors (unittest.TestResult attributo): Loading and running tests.
                                                             (line  248)
* Errors;logging:                        logging — Logging facility for Python.
                                                             (line    8)
* ErrorStream (classe in wsgiref.types): wsgiref types – WSGI types for static type checking.
                                                             (line   28)
* ErrorString() (nel modulo xml.parsers.expat): xml parsers expat — Fast XML parsing using Expat.
                                                             (line   41)
* ERRORTOKEN (nel modulo token):         token — Constants used with Python parse trees.
                                                             (line  195)
* esadecimale;letterali:                 Tipi Numerici — int float complex.
                                                             (line   19)
* ESC (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line  106)
* escape (shlex.shlex attributo):        shlex Objects.      (line  110)
* escape sequence:                       Formal grammar.     (line   28)
* escape() (nel modulo glob):            glob — Unix style pathname pattern expansion.
                                                             (line  104)
* escape() (nel modulo html):            html — HyperText Markup Language support.
                                                             (line   12)
* escape() (nel modulo re):              Functions.          (line  256)
* escape() (nel modulo xml.sax.saxutils): xml sax saxutils — SAX Utilities.
                                                             (line   14)
* escapechar (csv.Dialect attributo):    Dialects and Formatting Parameters.
                                                             (line   35)
* escapedquotes (shlex.shlex attributo): shlex Objects.      (line  122)
* ESHLIBVERS (nel modulo errno):         errno — Standard errno system symbols.
                                                             (line  683)
* ESHUTDOWN (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  474)
* esmtp_features (smtplib.SMTP attributo): SMTP Objects.     (line  366)
* ESOCKTNOSUPPORT (nel modulo errno):    errno — Standard errno system symbols.
                                                             (line  410)
* ESPIPE (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  148)
* ESRCH (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line   36)
* ESRMNT (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  310)
* ESTALE (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  517)
* ESTRPIPE (nel modulo errno):           errno — Standard errno system symbols.
                                                             (line  378)
* ETB (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   94)
* ETH_P_ALL (nel modulo socket):         Constants<8>.       (line  231)
* ETHERTYPE_ARP (nel modulo socket):     Constants<8>.       (line  465)
* ETHERTYPE_IP (nel modulo socket):      Constants<8>.       (line  465)
* ETHERTYPE_IPV6 (nel modulo socket):    Constants<8>.       (line  465)
* ETHERTYPE_VLAN (nel modulo socket):    Constants<8>.       (line  465)
* ETIME (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  282)
* ETIMEDOUT (nel modulo errno):          errno — Standard errno system symbols.
                                                             (line  483)
* Etiny() (decimal.Context metodo):      Context objects.    (line  253)
* ETOOMANYREFS (nel modulo errno):       errno — Standard errno system symbols.
                                                             (line  479)
* Etop() (decimal.Context metodo):       Context objects.    (line  259)
* ETX (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   28)
* ETXTBSY (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  136)
* EUCLEAN (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  521)
* EUNATCH (nel modulo errno):            errno — Standard errno system symbols.
                                                             (line  230)
* EUSERS (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  382)
* evaluate function:                     Glossary.           (line  564)
* evaluate_bound() (typing.TypeVar metodo): Building generic types and type aliases.
                                                             (line  184)
* evaluate_constraints() (typing.TypeVar metodo): Building generic types and type aliases.
                                                             (line  206)
* evaluate_default() (typing.ParamSpec metodo): Building generic types and type aliases.
                                                             (line  482)
* evaluate_default() (typing.TypeVar metodo): Building generic types and type aliases.
                                                             (line  225)
* evaluate_default() (typing.TypeVarTuple metodo): Building generic types and type aliases.
                                                             (line  369)
* evaluate_forward_ref() (nel modulo typing): Introspection helpers.
                                                             (line  174)
* evaluate_value() (typing.TypeAliasType metodo): Building generic types and type aliases.
                                                             (line  610)
* evaluate() (annotationlib.ForwardRef metodo): Classes<4>.  (line   65)
* evaluation;order:                      Evaluation order.   (line    6)
* Event (classe in asyncio):             Event.              (line    6)
* Event (classe in multiprocessing):     Synchronization primitives.
                                                             (line   58)
* Event (classe in threading):           Event objects.      (line   14)
* event scheduling:                      sched — Event scheduler.
                                                             (line    8)
* EVENT_READ (nel modulo selectors):     Classes<3>.         (line   23)
* EVENT_WRITE (nel modulo selectors):    Classes<3>.         (line   26)
* Event() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  185)
* eventfd_read() (nel modulo os):        Files and Directories.
                                                             (line 1911)
* eventfd_write() (nel modulo os):       Files and Directories.
                                                             (line 1921)
* eventfd() (nel modulo os):             Files and Directories.
                                                             (line 1858)
* EventLoop (classe in asyncio):         Event Loop Implementations.
                                                             (line   43)
* events (selectors.SelectorKey attributo): Classes<3>.      (line   44)
* events (widgets):                      Bindings and Events.
                                                             (line    6)
* EWOULDBLOCK (nel modulo errno):        errno — Standard errno system symbols.
                                                             (line  197)
* EX_CANTCREAT (nel modulo os):          Process Management. (line  207)
* EX_CONFIG (nel modulo os):             Process Management. (line  243)
* EX_DATAERR (nel modulo os):            Process Management. (line  156)
* EX_IOERR (nel modulo os):              Process Management. (line  214)
* EX_NOHOST (nel modulo os):             Process Management. (line  175)
* EX_NOINPUT (nel modulo os):            Process Management. (line  162)
* EX_NOPERM (nel modulo os):             Process Management. (line  236)
* EX_NOTFOUND (nel modulo os):           Process Management. (line  250)
* EX_NOUSER (nel modulo os):             Process Management. (line  169)
* EX_OK (nel modulo os):                 Process Management. (line  141)
* EX_OSERR (nel modulo os):              Process Management. (line  193)
* EX_OSFILE (nel modulo os):             Process Management. (line  200)
* EX_PROTOCOL (nel modulo os):           Process Management. (line  229)
* EX_SOFTWARE (nel modulo os):           Process Management. (line  187)
* EX_TEMPFAIL (nel modulo os):           Process Management. (line  221)
* EX_UNAVAILABLE (nel modulo os):        Process Management. (line  181)
* EX_USAGE (nel modulo os):              Process Management. (line  149)
* EXACT_TOKEN_TYPES (nel modulo token):  token — Constants used with Python parse trees.
                                                             (line  362)
* Example (classe in doctest):           Example Objects.    (line    6)
* example (doctest.DocTestFailure attributo): Debugging.     (line  200)
* example (doctest.UnexpectedException attributo): Debugging.
                                                             (line  221)
* examples (doctest.DocTest attributo):  DocTest Objects.    (line   17)
* exc_info (doctest.UnexpectedException attributo): Debugging.
                                                             (line  225)
* exc_info (in module sys):              Traceback objects.  (line    6)
* exc_info (in module sys) <1>:          Exceptions<23>.     (line   45)
* exc_info() (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line  448)
* exc_msg (doctest.Example attributo):   Example Objects.    (line   31)
* exc_type (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line   79)
* exc_type_str (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line   85)
* excel (classe in csv):                 Module Contents<3>. (line  207)
* excel_tab (classe in csv):             Module Contents<3>. (line  213)
* ExceptHandler (classe in ast):         Control flow.       (line  201)
* excepthook() (nel modulo sys):         sys — System-specific parameters and functions.
                                                             (line  392)
* excepthook() (nel modulo threading):   Reference<2>.       (line   26)
* exception:                             Exceptions.         (line    6)
* exception <1>:                         The raise statement.
                                                             (line    6)
* Exception:                             Base classes.       (line   66)
* EXCEPTION (nel modulo _tkinter):       File Handlers.      (line   41)
* exception handler:                     Exceptions.         (line    6)
* EXCEPTION_HANDLED (monitoring event):  Events.             (line   35)
* exception;AssertionError:              The assert statement.
                                                             (line   21)
* exception;AttributeError:              Attribute references.
                                                             (line   10)
* exception;chaining:                    The raise statement.
                                                             (line   30)
* exception;chaining <1>:                Exception context.  (line    6)
* exception;GeneratorExit:               Generator-iterator methods.
                                                             (line   65)
* exception;GeneratorExit <1>:           Asynchronous generator-iterator methods.
                                                             (line   61)
* exception;handler:                     Traceback objects.  (line    6)
* exception;ImportError:                 The import statement.
                                                             (line    6)
* exception;NameError:                   Identifiers Names.  (line   10)
* exception;StopAsyncIteration:          Asynchronous generator-iterator methods.
                                                             (line   10)
* exception;StopIteration:               Generator-iterator methods.
                                                             (line   12)
* exception;StopIteration <1>:           The yield statement.
                                                             (line    6)
* exception;TypeError:                   Unary arithmetic and bitwise operations.
                                                             (line   23)
* exception;ValueError:                  Shifting operations.
                                                             (line   20)
* exception;ZeroDivisionError:           Binary arithmetic operations.
                                                             (line   37)
* exception() (asyncio.Future metodo):   Future Object.      (line  123)
* exception() (asyncio.Task metodo):     Task Object.        (line   87)
* exception() (concurrent.futures.Future metodo): Future Objects.
                                                             (line   52)
* exception() (logging.Logger metodo):   Logger Objects.     (line  320)
* exception() (nel modulo logging):      Module-Level Functions.
                                                             (line   92)
* exception() (nel modulo sys):          sys — System-specific parameters and functions.
                                                             (line  436)
* ExceptionGroup:                        Exception groups.   (line   12)
* exceptions (BaseExceptionGroup attributo): Exception groups.
                                                             (line   38)
* exceptions (pdb command):              Debugger commands.  (line  466)
* exceptions (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line   53)
* excinfo (concurrent.interpreters.ExecutionFailed attributo): Exceptions<12>.
                                                             (line   21)
* EXCLAMATION (nel modulo token):        token — Constants used with Python parse trees.
                                                             (line  353)
* exclusive;or:                          Binary bitwise operations.
                                                             (line   16)
* EXDEV (nel modulo errno):              errno — Standard errno system symbols.
                                                             (line  102)
* exec_module() (importlib.abc.InspectLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  262)
* exec_module() (importlib.abc.Loader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  114)
* exec_module() (importlib.abc.SourceLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  409)
* exec_module() (importlib.machinery.ExtensionFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  322)
* exec_module() (zipimport.zipimporter metodo): zipimporter Objects.
                                                             (line   31)
* exec_prefix (nel modulo sys):          sys — System-specific parameters and functions.
                                                             (line  468)
* exec() (concurrent.interpreters.Interpreter metodo): Interpreter objects.
                                                             (line   43)
* execl() (nel modulo os):               Process Management. (line   53)
* execle() (nel modulo os):              Process Management. (line   53)
* execlp() (nel modulo os):              Process Management. (line   53)
* execlpe() (nel modulo os):             Process Management. (line   53)
* executable (in module sys):            Process-wide parameters.
                                                             (line  122)
* executable (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line  494)
* Executable Zip Files:                  zipapp — Manage executable Python zip archives.
                                                             (line   10)
* execute() (sqlite3.Connection metodo): Connection objects. (line   97)
* execute() (sqlite3.Cursor metodo):     Cursor objects.     (line   24)
* executemany() (sqlite3.Connection metodo): Connection objects.
                                                             (line  103)
* executemany() (sqlite3.Cursor metodo): Cursor objects.     (line   59)
* executescript() (sqlite3.Connection metodo): Connection objects.
                                                             (line  109)
* executescript() (sqlite3.Cursor metodo): Cursor objects.   (line  101)
* execution model:                       Execution model.    (line    6)
* execution;frame:                       Structure of a program.
                                                             (line   18)
* execution;frame <1>:                   Class definitions.  (line    6)
* execution;stack:                       Traceback objects.  (line    6)
* ExecutionFailed:                       Exceptions<12>.     (line   16)
* ExecutionLoader (classe in importlib.abc): importlib abc – Abstract base classes related to import.
                                                             (line  275)
* Executor (classe in concurrent.futures): Executor Objects. (line    6)
* execv() (nel modulo os):               Process Management. (line   53)
* execve() (nel modulo os):              Process Management. (line   53)
* execvp() (nel modulo os):              Process Management. (line   53)
* execvpe() (nel modulo os):             Process Management. (line   53)
* EXFULL (nel modulo errno):             errno — Standard errno system symbols.
                                                             (line  250)
* exists() (nel modulo os.path):         os path — Common pathname manipulations.
                                                             (line  115)
* exists() (pathlib.Path metodo):        Querying file type and status.
                                                             (line   45)
* exists() (pathlib.types.PathInfo metodo): Protocols.       (line   17)
* exists() (tkinter.ttk.Treeview metodo): ttk Treeview.      (line   89)
* exists() (zipfile.Path metodo):        Path objects.       (line   74)
* exit (C function):                     Process Control.    (line   23)
* exit (variabile built-in):             Constants added by the site module.
                                                             (line   11)
* exit() (argparse.ArgumentParser metodo): Exiting methods.  (line    6)
* exit() (nel modulo _thread):           _thread — Low-level threading API.
                                                             (line   78)
* exit() (nel modulo sys):               sys — System-specific parameters and functions.
                                                             (line  501)
* exitcode (multiprocessing.Process attributo): Process and exceptions.
                                                             (line  159)
* exitonclick() (nel modulo turtle):     Methods specific to Screen not inherited from TurtleScreen.
                                                             (line   10)
* ExitStack (classe in contextlib):      Utilities.          (line  503)
* exp() (decimal.Context metodo):        Context objects.    (line  324)
* exp() (decimal.Decimal metodo):        Decimal objects.    (line  234)
* exp() (nel modulo cmath):              Power and logarithmic functions.
                                                             (line    6)
* exp() (nel modulo math):               Power exponential and logarithmic functions.
                                                             (line   12)
* exp2() (nel modulo math):              Power exponential and logarithmic functions.
                                                             (line   18)
* expand_tabs (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  173)
* expand() (re.Match metodo):            Match Objects.      (line   23)
* ExpandEnvironmentStrings() (nel modulo winreg): Functions<13>.
                                                             (line  228)
* expandNode() (xml.dom.pulldom.DOMEventStream metodo): DOMEventStream Objects.
                                                             (line   21)
* expandtabs() (bytearray metodo):       Operazioni su Bytes e Bytearray.
                                                             (line  496)
* expandtabs() (bytes metodo):           Operazioni su Bytes e Bytearray.
                                                             (line  496)
* expandtabs() (str metodo):             Metodi per le Stringhe.
                                                             (line  145)
* expanduser() (nel modulo os.path):     os path — Common pathname manipulations.
                                                             (line  136)
* expanduser() (pathlib.Path metodo):    Expanding and resolving paths.
                                                             (line   18)
* expandvars() (nel modulo os.path):     os path — Common pathname manipulations.
                                                             (line  160)
* Expat:                                 xml parsers expat — Fast XML parsing using Expat.
                                                             (line   11)
* ExpatError:                            xml parsers expat — Fast XML parsing using Expat.
                                                             (line   24)
* expected (asyncio.IncompleteReadError attributo): Exceptions<15>.
                                                             (line   52)
* expectedFailure() (nel modulo unittest): Skipping tests and expected failures.
                                                             (line   98)
* expectedFailures (unittest.TestResult attributo): Loading and running tests.
                                                             (line  268)
* expired() (asyncio.Timeout metodo):    Timeouts.           (line   72)
* expires (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   53)
* expires (http.cookies.Morsel attributo): Morsel Objects.   (line   13)
* exploded (ipaddress.IPv4Address attributo): Address objects.
                                                             (line   64)
* exploded (ipaddress.IPv4Network attributo): Network objects.
                                                             (line  109)
* exploded (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  263)
* exploded (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  322)
* expm1() (nel modulo math):             Power exponential and logarithmic functions.
                                                             (line   24)
* expovariate() (nel modulo random):     Real-valued distributions.
                                                             (line   38)
* Expr (classe in ast):                  Expressions<2>.     (line    6)
* expression:                            Expressions.        (line    6)
* expression <1>:                        Glossary.           (line  570)
* Expression (classe in ast):            Root nodes.         (line   26)
* expression (string.templatelib.Interpolation attributo): Types.
                                                             (line  222)
* expression;list:                       Expression lists.   (line    6)
* expression;list <1>:                   Expression statements.
                                                             (line    6)
* expression;list <2>:                   Expression statements.
                                                             (line    6)
* expression;statement:                  Expression statements.
                                                             (line    6)
* expunge() (imaplib.IMAP4 metodo):      IMAP4 Objects.      (line   93)
* extend_path() (nel modulo pkgutil):    pkgutil — Package extension utility.
                                                             (line   19)
* extend() (array.array metodo):         array — Efficient arrays of numeric values.
                                                             (line  158)
* extend() (collections.deque metodo):   deque objects.      (line   59)
* extend() (sequence metodo):            Tipi di Sequenza Mutabili.
                                                             (line   94)
* extend() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line   93)
* EXTENDED_ARG (opcode):                 Python Bytecode Instructions.
                                                             (line 1208)
* ExtendedContext (nel modulo decimal):  Context objects.    (line   85)
* ExtendedInterpolation (classe in configparser): Interpolation of values.
                                                             (line   41)
* extendleft() (collections.deque metodo): deque objects.    (line   64)
* extension module:                      Glossary.           (line  581)
* EXTENSION_SUFFIXES (nel modulo importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line   50)
* extension;module:                      The standard type hierarchy.
                                                             (line    6)
* ExtensionFileLoader (classe in importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line  289)
* extensions_map (http.server.SimpleHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  412)
* External Data Representation:          Data stream format. (line    6)
* external_attr (zipfile.ZipInfo attributo): ZipInfo objects.
                                                             (line  142)
* ExternalClashError:                    Exceptions<20>.     (line   24)
* ExternalEntityParserCreate() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line   44)
* ExternalEntityRefHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  424)
* extra (zipfile.ZipInfo attributo):     ZipInfo objects.    (line  108)
* extract_cookies() (http.cookiejar.CookieJar metodo): CookieJar and FileCookieJar Objects.
                                                             (line   31)
* extract_stack() (nel modulo traceback): Module-Level Functions<2>.
                                                             (line   94)
* extract_tb() (nel modulo traceback):   Module-Level Functions<2>.
                                                             (line   82)
* extract_version (zipfile.ZipInfo attributo): ZipInfo objects.
                                                             (line  122)
* extract() (tarfile.TarFile metodo):    TarFile Objects.    (line  178)
* extract() (traceback.StackSummary metodo della classe): StackSummary Objects.
                                                             (line   12)
* extract() (zipfile.ZipFile metodo):    ZipFile objects.    (line  193)
* extractall() (tarfile.TarFile metodo): TarFile Objects.    (line  138)
* extractall() (zipfile.ZipFile metodo): ZipFile objects.    (line  220)
* ExtractError:                          tarfile — Read and write tar archive files.
                                                             (line  265)
* extractfile() (tarfile.TarFile metodo): TarFile Objects.   (line  209)
* extraction_filter (tarfile.TarFile attributo): TarFile Objects.
                                                             (line  245)
* extsep (nel modulo os):                Miscellaneous System Information.
                                                             (line  132)
* f_back (frame attribute):              Frame objects.      (line   10)
* f_back (frame attributo):              Special read-only attributes<3>.
                                                             (line    6)
* f_builtins (frame attribute):          Frame objects.      (line   10)
* f_builtins (frame attributo):          Special read-only attributes<3>.
                                                             (line   29)
* f_code (frame attribute):              Frame objects.      (line   10)
* f_code (frame attributo):              Special read-only attributes<3>.
                                                             (line   10)
* F_CONTIGUOUS (inspect.BufferFlags attributo): Buffer flags.
                                                             (line   27)
* f_contiguous (memoryview attributo):   Memory Views.       (line  523)
* f_generator (frame attribute):         Frame objects.      (line   10)
* f_generator (frame attributo):         Special read-only attributes<3>.
                                                             (line   38)
* f_globals (frame attribute):           Frame objects.      (line   10)
* f_globals (frame attributo):           Special read-only attributes<3>.
                                                             (line   25)
* f_lasti (frame attribute):             Frame objects.      (line   10)
* f_lasti (frame attributo):             Special read-only attributes<3>.
                                                             (line   33)
* f_lineno (frame attribute):            Special read-only attributes<3>.
                                                             (line   44)
* f_lineno (frame attributo):            Special writable attributes<2>.
                                                             (line   23)
* f_locals (frame attribute):            Frame objects.      (line   10)
* f_locals (frame attributo):            Special read-only attributes<3>.
                                                             (line   16)
* F_LOCK (nel modulo os):                File Descriptor Operations.
                                                             (line  281)
* F_OK (nel modulo os):                  Files and Directories.
                                                             (line  107)
* F_TEST (nel modulo os):                File Descriptor Operations.
                                                             (line  281)
* F_TLOCK (nel modulo os):               File Descriptor Operations.
                                                             (line  281)
* f_trace (frame attribute):             Special read-only attributes<3>.
                                                             (line   45)
* f_trace (frame attributo):             Special writable attributes<2>.
                                                             (line    6)
* f_trace_lines (frame attribute):       Special read-only attributes<3>.
                                                             (line   45)
* f_trace_lines (frame attributo):       Special writable attributes<2>.
                                                             (line   12)
* f_trace_opcodes (frame attribute):     Special read-only attributes<3>.
                                                             (line   45)
* f_trace_opcodes (frame attributo):     Special writable attributes<2>.
                                                             (line   16)
* F_ULOCK (nel modulo os):               File Descriptor Operations.
                                                             (line  281)
* f-string:                              Formattazione Avanzata dell’Output.
                                                             (line   98)
* f-string <1>:                          Raw string literals.
                                                             (line   25)
* f-string <2>:                          Glossary.           (line  586)
* f-strings:                             Metodi per le Stringhe.
                                                             (line  912)
* f-strings <1>:                         Glossary.           (line  589)
* f';formatted string literal:           Raw string literals.
                                                             (line   25)
* f";formatted string literal:           Raw string literals.
                                                             (line   25)
* fabs() (nel modulo math):              Floating point arithmetic.
                                                             (line   13)
* factorial() (nel modulo math):         Number-theoretic functions.
                                                             (line   23)
* factory() (importlib.util.LazyLoader metodo della classe): importlib util – Utility code for importers.
                                                             (line  222)
* FAIL_FAST (nel modulo doctest):        Option Flags.       (line  138)
* fail() (unittest.TestCase metodo):     Test cases.         (line  752)
* failed (doctest.TestResults attributo): TestResults objects.
                                                             (line    8)
* failfast (unittest.TestResult attributo): Loading and running tests.
                                                             (line  306)
* failureException (unittest.TestCase attributo): Test cases.
                                                             (line  757)
* failures (doctest.DocTestRunner attributo): DocTestRunner objects.
                                                             (line  139)
* failures (unittest.TestResult attributo): Loading and running tests.
                                                             (line  254)
* FakePath (classe in test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   60)
* False:                                 numbers Integral.   (line   27)
* False (Oggetto integrato):             Test del Valore di Verità.
                                                             (line   18)
* False (variabile built-in):            Built-in Constants. (line    8)
* falso:                                 Test del Valore di Verità.
                                                             (line    6)
* Falso:                                 Test del Valore di Verità.
                                                             (line   26)
* Falso <1>:                             Tipo Booleano - bool.
                                                             (line    9)
* families() (nel modulo tkinter.font):  tkinter font — Tkinter font wrapper.
                                                             (line   88)
* family (socket.socket attributo):      Socket Objects.     (line  621)
* fast (compression.zstd.Strategy attributo): Advanced parameter control.
                                                             (line  309)
* fast (pickle.Pickler attributo):       Module Interface.   (line  225)
* fatalError() (xml.sax.handler.ErrorHandler metodo): ErrorHandler Objects.
                                                             (line   24)
* Fault (classe in xmlrpc.client):       Fault Objects.      (line    6)
* faultCode (xmlrpc.client.Fault attributo): Fault Objects.  (line   11)
* faultString (xmlrpc.client.Fault attributo): Fault Objects.
                                                             (line   15)
* fchdir() (nel modulo os):              Files and Directories.
                                                             (line  282)
* fchmod() (nel modulo os):              File Descriptor Operations.
                                                             (line  122)
* fchown() (nel modulo os):              File Descriptor Operations.
                                                             (line  138)
* fcntl() (nel modulo fcntl):            fcntl — The fcntl and ioctl system calls.
                                                             (line   71)
* fd (selectors.SelectorKey attributo):  Classes<3>.         (line   40)
* fd_count() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line  100)
* fd() (nel modulo turtle):              Turtle motion.      (line    6)
* fdatasync() (nel modulo os):           File Descriptor Operations.
                                                             (line  153)
* fdopen() (nel modulo os):              File Object Creation.
                                                             (line    9)
* feature_external_ges (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line   81)
* feature_external_pes (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line   93)
* feature_namespace_prefixes (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line   60)
* feature_namespaces (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line   53)
* feature_string_interning (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line   67)
* feature_validation (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line   74)
* FEBRUARY (nel modulo calendar):        calendar — General calendar-related functions.
                                                             (line  490)
* feed_eof() (asyncio.StreamReader metodo): StreamReader.    (line   16)
* feed() (email.parser.BytesFeedParser metodo): FeedParser API.
                                                             (line   56)
* feed() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line    8)
* feed() (xml.etree.ElementTree.XMLParser metodo): XMLParser Objects.
                                                             (line   27)
* feed() (xml.etree.ElementTree.XMLPullParser metodo): XMLPullParser Objects.
                                                             (line   18)
* feed() (xml.sax.xmlreader.IncrementalParser metodo): IncrementalParser Objects.
                                                             (line    9)
* FeedParser (classe in email.parser):   FeedParser API.     (line   71)
* fetch() (imaplib.IMAP4 metodo):        IMAP4 Objects.      (line   99)
* fetchall() (sqlite3.Cursor metodo):    Cursor objects.     (line  150)
* fetchmany() (sqlite3.Cursor metodo):   Cursor objects.     (line  130)
* fetchone() (sqlite3.Cursor metodo):    Cursor objects.     (line  123)
* FF (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line   61)
* fflags (select.kevent attributo):      Kevent Objects.     (line   90)
* Field (classe in dataclasses):         Module contents<4>. (line  308)
* field_size_limit() (nel modulo csv):   Module Contents<3>. (line   96)
* field() (nel modulo dataclasses):      Module contents<4>. (line  206)
* fieldnames (csv.DictReader attributo): Reader Objects.     (line   31)
* fields (uuid.UUID attributo):          uuid — UUID objects according to RFC 9562.
                                                             (line   99)
* fields() (nel modulo dataclasses):     Module contents<4>. (line  336)
* FIFOTYPE (nel modulo tarfile):         tarfile — Read and write tar archive files.
                                                             (line  349)
* file (bdb.Breakpoint attributo):       bdb — Debugger framework.
                                                             (line   82)
* file (pyclbr.Class attributo):         Class Objects.      (line   12)
* file (pyclbr.Function attributo):      Function Objects.   (line   11)
* file object:                           Glossary.           (line  594)
* file object;io module:                 Overview<2>.        (line    6)
* FILE_ATTRIBUTE_ARCHIVE (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_COMPRESSED (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_DEVICE (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_DIRECTORY (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_ENCRYPTED (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_HIDDEN (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_INTEGRITY_STREAM (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_NO_SCRUB_DATA (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_NORMAL (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_NOT_CONTENT_INDEXED (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_OFFLINE (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_READONLY (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_REPARSE_POINT (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_SPARSE_FILE (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_SYSTEM (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_TEMPORARY (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* FILE_ATTRIBUTE_VIRTUAL (nel modulo stat): stat — Interpreting stat results.
                                                             (line  453)
* file_digest() (nel modulo hashlib):    File hashing.       (line    9)
* file_open() (urllib.request.FileHandler metodo): FileHandler Objects.
                                                             (line    6)
* file_size (zipfile.ZipInfo attributo): ZipInfo objects.    (line  158)
* file-like object:                      Glossary.           (line  610)
* file;byte-code:                        py_compile — Compile Python source files.
                                                             (line    8)
* file;copying:                          shutil — High-level file operations.
                                                             (line    8)
* file;large files:                      Large File Support. (line    6)
* file;mime.types:                       mimetypes — Map filenames to MIME types.
                                                             (line  141)
* file;modalità:                         Funzioni Incorporate.
                                                             (line 1359)
* fileConfig() (nel modulo logging.config): Configuration functions.
                                                             (line   61)
* FileCookieJar (classe in http.cookiejar): http cookiejar — Cookie handling for HTTP clients.
                                                             (line   57)
* FileDialog (classe in tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line   78)
* FileExistsError:                       OS exceptions.      (line   63)
* FileFinder (classe in importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line  154)
* FileHandler (classe in logging):       FileHandler.        (line   10)
* FileHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  471)
* FileInput (classe in fileinput):       fileinput — Iterate over lines from multiple input streams.
                                                             (line  139)
* FileIO (classe in io):                 Raw File I/O.       (line    6)
* filelineno() (nel modulo fileinput):   fileinput — Iterate over lines from multiple input streams.
                                                             (line  104)
* FileLoader (classe in importlib.abc):  importlib abc – Abstract base classes related to import.
                                                             (line  294)
* filemode() (nel modulo stat):          stat — Interpreting stat results.
                                                             (line  122)
* filename (doctest.DocTest attributo):  DocTest Objects.    (line   36)
* filename (http.cookiejar.FileCookieJar attributo): CookieJar and FileCookieJar Objects.
                                                             (line  154)
* filename (inspect.FrameInfo attributo): The interpreter stack.
                                                             (line   17)
* filename (inspect.Traceback attributo): The interpreter stack.
                                                             (line   58)
* filename (netrc.NetrcParseError attributo): netrc — netrc file processing.
                                                             (line   57)
* filename (OSError attributo):          Concrete exceptions.
                                                             (line  195)
* filename (SyntaxError attributo):      Concrete exceptions.
                                                             (line  324)
* filename (traceback.FrameSummary attributo): FrameSummary Objects.
                                                             (line   28)
* filename (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line   91)
* filename (tracemalloc.Frame attributo): Frame.             (line   13)
* filename (zipfile.ZipFile attributo):  ZipFile objects.    (line  359)
* filename (zipfile.ZipInfo attributo):  ZipInfo objects.    (line   51)
* filename_only (nel modulo tabnanny):   tabnanny — Detection of ambiguous indentation.
                                                             (line   31)
* filename_pattern (tracemalloc.Filter attributo): Filter.   (line   55)
* filename() (nel modulo fileinput):     fileinput — Iterate over lines from multiple input streams.
                                                             (line   86)
* filename2 (OSError attributo):         Concrete exceptions.
                                                             (line  195)
* filenames;pathname expansion:          glob — Unix style pathname pattern expansion.
                                                             (line    8)
* filenames;wildcard expansion:          fnmatch — Unix filename pattern matching.
                                                             (line    8)
* fileno() (bz2.BZ2File metodo):         De compression of files.
                                                             (line   88)
* fileno() (http.client.HTTPResponse metodo): HTTPResponse Objects.
                                                             (line   36)
* fileno() (io.IOBase metodo):           I/O Base Classes.   (line   62)
* fileno() (multiprocessing.connection.Connection metodo): Connection Objects.
                                                             (line   31)
* fileno() (nel modulo fileinput):       fileinput — Iterate over lines from multiple input streams.
                                                             (line   91)
* fileno() (select.devpoll metodo):      /dev/poll Polling Objects.
                                                             (line   24)
* fileno() (select.epoll metodo):        Edge and Level Trigger Polling epoll Objects.
                                                             (line   79)
* fileno() (select.kqueue metodo):       Kqueue Objects.     (line   14)
* fileno() (selectors.DevpollSelector metodo): Classes<3>.   (line  188)
* fileno() (selectors.EpollSelector metodo): Classes<3>.     (line  179)
* fileno() (selectors.KqueueSelector metodo): Classes<3>.    (line  199)
* fileno() (socket.socket metodo):       Socket Objects.     (line  119)
* fileno() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line   15)
* FileNotFoundError:                     OS exceptions.      (line   68)
* fileobj (selectors.SelectorKey attributo): Classes<3>.     (line   36)
* files_double_event() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line   94)
* files_select_event() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line   98)
* files() (importlib.resources.abc.TraversableResources metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line  172)
* files() (nel modulo importlib.metadata): Distribution files.
                                                             (line    6)
* files() (nel modulo importlib.resources): importlib resources – Package resource reading opening and access.
                                                             (line   52)
* filesystem encoding and error handler: Glossary.           (line  614)
* FileType (classe in argparse):         FileType objects.   (line    6)
* FileWrapper (classe in wsgiref.types): wsgiref types – WSGI types for static type checking.
                                                             (line   32)
* FileWrapper (classe in wsgiref.util):  wsgiref util – WSGI environment utilities.
                                                             (line  117)
* fill() (nel modulo textwrap):          textwrap — Text wrapping and filling.
                                                             (line   33)
* fill() (nel modulo turtle):            Filling.            (line   16)
* fill() (textwrap.TextWrapper metodo):  textwrap — Text wrapping and filling.
                                                             (line  301)
* fillcolor() (nel modulo turtle):       Color control.      (line   62)
* filling() (nel modulo turtle):         Filling.            (line    6)
* fillvalue (reprlib.Repr attributo):    Repr Objects.       (line   10)
* Filter (classe in logging):            Filter Objects.     (line   13)
* Filter (classe in tracemalloc):        Filter.             (line    6)
* filter (select.kevent attributo):      Kevent Objects.     (line   15)
* filter_command() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line  102)
* FILTER_DIR (nel modulo unittest.mock): FILTER_DIR.         (line    6)
* filter_traces() (tracemalloc.Snapshot metodo): Snapshot.   (line   35)
* filter() (logging.Filter metodo):      Filter Objects.     (line   20)
* filter() (logging.Handler metodo):     Handler Objects.    (line   61)
* filter() (logging.Logger metodo):      Logger Objects.     (line  335)
* filter() (nel modulo curses):          Functions<5>.       (line  136)
* filter() (nel modulo fnmatch):         fnmatch — Unix filename pattern matching.
                                                             (line   75)
* FilterError:                           tarfile — Read and write tar archive files.
                                                             (line  276)
* filterfalse() (nel modulo fnmatch):    fnmatch — Unix filename pattern matching.
                                                             (line   82)
* filterfalse() (nel modulo itertools):  Itertool Functions. (line  291)
* filterwarnings() (nel modulo warnings): Available Functions.
                                                             (line  112)
* Final (nel modulo typing):             Special forms.      (line  231)
* final() (nel modulo typing):           Functions and decorators.
                                                             (line  311)
* finalization, of objects:              Finalization and De-allocation.
                                                             (line    6)
* finalize (classe in weakref):          weakref — Weak references.
                                                             (line  268)
* finalize_dict() (nel modulo compression.zstd): Zstandard dictionaries.
                                                             (line   28)
* finalizer:                             Basic customization.
                                                             (line   55)
* find_class() (pickle protocol):        Restricting Globals.
                                                             (line    6)
* find_class() (pickle.Unpickler metodo): Module Interface.  (line  309)
* find_library() (nel modulo ctypes.util): Utility functions.
                                                             (line  129)
* find_longest_match() (difflib.SequenceMatcher metodo): SequenceMatcher Objects.
                                                             (line   64)
* find_msvcrt() (nel modulo ctypes.util): Utility functions. (line  141)
* find_spec() (importlib.abc.MetaPathFinder metodo): importlib abc – Abstract base classes related to import.
                                                             (line   35)
* find_spec() (importlib.abc.PathEntryFinder metodo): importlib abc – Abstract base classes related to import.
                                                             (line   71)
* find_spec() (importlib.machinery.FileFinder metodo): importlib machinery – Importers and path hooks.
                                                             (line  184)
* find_spec() (importlib.machinery.PathFinder metodo della classe): importlib machinery – Importers and path hooks.
                                                             (line  117)
* find_spec() (nel modulo importlib.util): importlib util – Utility code for importers.
                                                             (line  101)
* find_spec() (zipimport.zipimporter metodo): zipimporter Objects.
                                                             (line   38)
* find_unused_port() (nel modulo test.support.socket_helper): test support socket_helper — Utilities for socket tests.
                                                             (line   15)
* find_user_password() (urllib.request.HTTPPasswordMgr metodo): HTTPPasswordMgr Objects.
                                                             (line   16)
* find_user_password() (urllib.request.HTTPPasswordMgrWithPriorAuth metodo): HTTPPasswordMgrWithPriorAuth Objects.
                                                             (line   19)
* find() (bytearray metodo):             Operazioni su Bytes e Bytearray.
                                                             (line  138)
* find() (bytes metodo):                 Operazioni su Bytes e Bytearray.
                                                             (line  138)
* find() (doctest.DocTestFinder metodo): DocTestFinder objects.
                                                             (line   32)
* find() (mmap.mmap metodo):             mmap — Memory-mapped file support.
                                                             (line  195)
* find() (nel modulo gettext):           Class-based API.    (line   14)
* find() (str metodo):                   Metodi per le Stringhe.
                                                             (line  169)
* find() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line  101)
* find() (xml.etree.ElementTree.ElementTree metodo): ElementTree Objects.
                                                             (line   21)
* findall() (nel modulo re):             Functions.          (line  131)
* findall() (re.Pattern metodo):         Regular Expression Objects.
                                                             (line   85)
* findall() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line  110)
* findall() (xml.etree.ElementTree.ElementTree metodo): ElementTree Objects.
                                                             (line   26)
* findCaller() (logging.Logger metodo):  Logger Objects.     (line  352)
* finder:                                Finders and loaders.
                                                             (line    6)
* finder <1>:                            Glossary.           (line  634)
* finder;find_spec:                      The meta path.      (line    6)
* findfile() (nel modulo test.support):  test support — Utilities for the Python test suite.
                                                             (line  293)
* finditer() (nel modulo re):            Functions.          (line  157)
* finditer() (re.Pattern metodo):        Regular Expression Objects.
                                                             (line   91)
* findlabels() (nel modulo dis):         Analysis functions. (line  190)
* findlinestarts() (nel modulo dis):     Analysis functions. (line  173)
* findtext() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line  119)
* findtext() (xml.etree.ElementTree.ElementTree metodo): ElementTree Objects.
                                                             (line   31)
* finish_request() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line  129)
* finish() (socketserver.BaseRequestHandler metodo): Request Handler Objects.
                                                             (line   35)
* finish() (tkinter.dnd.DndHandler metodo): tkinter dnd — Drag and drop support.
                                                             (line   52)
* FIRST_COMPLETED (nel modulo asyncio):  Waiting Primitives. (line   35)
* FIRST_COMPLETED (nel modulo concurrent.futures): Module Functions.
                                                             (line   30)
* FIRST_EXCEPTION (nel modulo asyncio):  Waiting Primitives. (line   39)
* FIRST_EXCEPTION (nel modulo concurrent.futures): Module Functions.
                                                             (line   34)
* firstChild (xml.dom.Node attributo):   Node Objects.       (line   54)
* FirstHeaderLineIsContinuationDefect:   email errors Exception and Defect classes.
                                                             (line   92)
* firstkey() (dbm.gnu.gdbm metodo):      dbm gnu — GNU database manager.
                                                             (line   98)
* firstweekday (calendar.Calendar attributo): calendar — General calendar-related functions.
                                                             (line   40)
* firstweekday() (nel modulo calendar):  calendar — General calendar-related functions.
                                                             (line  360)
* fix_missing_locations() (nel modulo ast): ast helpers.     (line  145)
* fix_sentence_endings (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  228)
* Flag (classe in enum):                 Data Types<2>.      (line  435)
* flag_bits (zipfile.ZipInfo attributo): ZipInfo objects.    (line  130)
* FlagBoundary (classe in enum):         Data Types<2>.      (line  671)
* flags (decimal.Context attributo):     Context objects.    (line  142)
* flags (nel modulo sys):                sys — System-specific parameters and functions.
                                                             (line  532)
* flags (re.Pattern attributo):          Regular Expression Objects.
                                                             (line  107)
* flags (select.kevent attributo):       Kevent Objects.     (line   52)
* flash() (nel modulo curses):           Functions<5>.       (line  147)
* flatten() (email.generator.BytesGenerator metodo): email generator Generating MIME documents.
                                                             (line   80)
* flatten() (email.generator.Generator metodo): email generator Generating MIME documents.
                                                             (line  176)
* flattening;objects:                    pickle — Python object serialization.
                                                             (line    8)
* float (classe built-in):               Funzioni Incorporate.
                                                             (line  749)
* float_info (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line  637)
* float_repr_style (nel modulo sys):     sys — System-specific parameters and functions.
                                                             (line  745)
* floating-point literal:                Numeric literals.   (line    6)
* floating-point;letterali:              Tipi Numerici — int float complex.
                                                             (line   19)
* floating-point;number:                 numbers Real float. (line    6)
* FloatingPointError:                    Concrete exceptions.
                                                             (line   40)
* FloatOperation (classe in decimal):    Signals.            (line  102)
* flock() (nel modulo fcntl):            fcntl — The fcntl and ioctl system calls.
                                                             (line  171)
* floor division:                        Glossary.           (line  646)
* floor() (nel modulo math):             Tipi Numerici — int float complex.
                                                             (line  117)
* floor() (nel modulo math) <1>:         Floating point arithmetic.
                                                             (line   17)
* FloorDiv (classe in ast):              Expressions<2>.     (line   53)
* floordiv() (nel modulo operator):      operator — Standard operators as functions.
                                                             (line  100)
* FLUSH_BLOCK (compression.zstd.ZstdCompressor attributo): Compressing and decompressing data in memory.
                                                             (line  138)
* FLUSH_FRAME (compression.zstd.ZstdCompressor attributo): Compressing and decompressing data in memory.
                                                             (line  145)
* flush_headers() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  331)
* flush_std_streams() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  425)
* flush() (bz2.BZ2Compressor metodo):    Incremental de compression.
                                                             (line   25)
* flush() (compression.zstd.ZstdCompressor metodo): Compressing and decompressing data in memory.
                                                             (line   98)
* flush() (io.BufferedWriter metodo):    Buffered Streams.   (line  126)
* flush() (io.IOBase metodo):            I/O Base Classes.   (line   68)
* flush() (logging.Handler metodo):      Handler Objects.    (line   69)
* flush() (logging.handlers.BufferingHandler metodo): MemoryHandler.
                                                             (line   30)
* flush() (logging.handlers.MemoryHandler metodo): MemoryHandler.
                                                             (line   62)
* flush() (logging.StreamHandler metodo): StreamHandler.     (line   25)
* flush() (lzma.LZMACompressor metodo):  Compressing and decompressing data in memory<2>.
                                                             (line   91)
* flush() (mailbox.Mailbox metodo):      Mailbox objects.    (line  250)
* flush() (mailbox.Maildir metodo):      Maildir objects.    (line  204)
* flush() (mailbox.MH metodo):           MH objects.         (line  102)
* flush() (mmap.mmap metodo):            mmap — Memory-mapped file support.
                                                             (line  205)
* flush() (xml.etree.ElementTree.XMLParser metodo): XMLParser Objects.
                                                             (line   31)
* flush() (xml.etree.ElementTree.XMLPullParser metodo): XMLPullParser Objects.
                                                             (line   22)
* flush() (zlib.Compress metodo):        zlib — Compression compatible with gzip.
                                                             (line  211)
* flush() (zlib.Decompress metodo):      zlib — Compression compatible with gzip.
                                                             (line  284)
* flushinp() (nel modulo curses):        Functions<5>.       (line  154)
* FlushKey() (nel modulo winreg):        Functions<13>.      (line  239)
* fma() (decimal.Context metodo):        Context objects.    (line  328)
* fma() (decimal.Decimal metodo):        Decimal objects.    (line  287)
* fma() (nel modulo math):               Floating point arithmetic.
                                                             (line   23)
* fmean() (nel modulo statistics):       Function details.   (line   49)
* fmod() (nel modulo math):              Floating point arithmetic.
                                                             (line   38)
* FMT_BINARY (nel modulo plistlib):      plistlib — Generate and parse Apple plist files.
                                                             (line  162)
* FMT_XML (nel modulo plistlib):         plistlib — Generate and parse Apple plist files.
                                                             (line  156)
* fnmatch() (nel modulo fnmatch):        fnmatch — Unix filename pattern matching.
                                                             (line   50)
* fnmatchcase() (nel modulo fnmatch):    fnmatch — Unix filename pattern matching.
                                                             (line   69)
* focus() (tkinter.ttk.Treeview metodo): ttk Treeview.       (line   93)
* fold (datetime.datetime attributo):    datetime Objects.   (line  339)
* fold (datetime.time attributo):        time Objects.       (line   71)
* fold_binary() (email.policy.Compat32 metodo): email policy Policy Objects.
                                                             (line  608)
* fold_binary() (email.policy.EmailPolicy metodo): email policy Policy Objects.
                                                             (line  487)
* fold_binary() (email.policy.Policy metodo): email policy Policy Objects.
                                                             (line  351)
* fold() (email.headerregistry.BaseHeader metodo): email headerregistry Custom Header Objects.
                                                             (line   72)
* fold() (email.policy.Compat32 metodo): email policy Policy Objects.
                                                             (line  600)
* fold() (email.policy.EmailPolicy metodo): email policy Policy Objects.
                                                             (line  467)
* fold() (email.policy.Policy metodo):   email policy Policy Objects.
                                                             (line  336)
* Font (classe in tkinter.font):         tkinter font — Tkinter font wrapper.
                                                             (line   20)
* For (classe in ast):                   Control flow.       (line   44)
* FOR_ITER (opcode):                     Python Bytecode Instructions.
                                                             (line  925)
* for;in comprehensions:                 Displays for lists sets and dictionaries.
                                                             (line   14)
* forget() (nel modulo test.support.import_helper): test support import_helper — Utilities for import tests.
                                                             (line   11)
* forget() (tkinter.ttk.Notebook metodo): ttk Notebook.      (line   18)
* fork() (nel modulo os):                Process Management. (line  256)
* fork() (nel modulo pty):               pty — Pseudo-terminal utilities.
                                                             (line   22)
* ForkingMixIn (classe in socketserver): Server Creation Notes.
                                                             (line   27)
* ForkingTCPServer (classe in socketserver): Server Creation Notes.
                                                             (line   74)
* ForkingUDPServer (classe in socketserver): Server Creation Notes.
                                                             (line   74)
* ForkingUnixDatagramServer (classe in socketserver): Server Creation Notes.
                                                             (line   74)
* ForkingUnixStreamServer (classe in socketserver): Server Creation Notes.
                                                             (line   74)
* forkpty() (nel modulo os):             Process Management. (line  300)
* Format (classe in annotationlib):      Classes<4>.         (line    6)
* FORMAT (inspect.BufferFlags attributo): Buffer flags.      (line   19)
* format (memoryview attributo):         Memory Views.       (line  462)
* format (multiprocessing.shared_memory.ShareableList attributo): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  341)
* format (struct.Struct attributo):      Classes<2>.         (line   54)
* format_call_graph() (nel modulo asyncio): Call Graph Introspection.
                                                             (line   70)
* format_datetime() (nel modulo email.utils): email utils Miscellaneous utilities.
                                                             (line  173)
* format_exc() (nel modulo traceback):   Module-Level Functions<2>.
                                                             (line  164)
* format_exception_only() (nel modulo traceback): Module-Level Functions<2>.
                                                             (line  118)
* format_exception_only() (traceback.TracebackException metodo): TracebackException Objects.
                                                             (line  155)
* format_exception() (nel modulo traceback): Module-Level Functions<2>.
                                                             (line  148)
* format_field() (string.Formatter metodo): Custom String Formatting.
                                                             (line  106)
* format_frame_summary() (traceback.StackSummary metodo): StackSummary Objects.
                                                             (line   53)
* format_help() (argparse.ArgumentParser metodo): Printing help.
                                                             (line   30)
* format_list() (nel modulo traceback):  Module-Level Functions<2>.
                                                             (line  108)
* format_map() (str metodo):             Metodi per le Stringhe.
                                                             (line  226)
* FORMAT_SIMPLE (opcode):                Python Bytecode Instructions.
                                                             (line 1234)
* format_spec (string.templatelib.Interpolation attributo): Types.
                                                             (line  258)
* format_stack_entry() (bdb.Bdb metodo): bdb — Debugger framework.
                                                             (line  462)
* format_stack() (nel modulo traceback): Module-Level Functions<2>.
                                                             (line  173)
* format_string() (nel modulo locale):   locale — Internationalization services.
                                                             (line  472)
* format_tb() (nel modulo traceback):    Module-Level Functions<2>.
                                                             (line  169)
* format_usage() (argparse.Action metodo): Action classes.   (line   57)
* format_usage() (argparse.ArgumentParser metodo): Printing help.
                                                             (line   25)
* FORMAT_WITH_SPEC (opcode):             Python Bytecode Instructions.
                                                             (line 1246)
* format() (built-in function);__str__() (object method): Basic customization.
                                                             (line  131)
* format() (inspect.Signature metodo):   Introspecting callables with the Signature object.
                                                             (line  166)
* format() (logging.BufferingFormatter metodo): Formatter Objects.
                                                             (line  154)
* format() (logging.Formatter metodo):   Formatter Objects.  (line   51)
* format() (logging.Handler metodo):     Handler Objects.    (line  104)
* format() (pprint.PrettyPrinter metodo): PrettyPrinter Objects.
                                                             (line   83)
* format() (str metodo):                 Metodi per le Stringhe.
                                                             (line  191)
* format() (string.Formatter metodo):    Custom String Formatting.
                                                             (line   17)
* format() (traceback.StackSummary metodo): StackSummary Objects.
                                                             (line   38)
* format() (traceback.TracebackException metodo): TracebackException Objects.
                                                             (line  143)
* format() (tracemalloc.Traceback metodo): Traceback.        (line   37)
* formataddr() (nel modulo email.utils): email utils Miscellaneous utilities.
                                                             (line   71)
* formatargvalues() (nel modulo inspect): Classes and functions<2>.
                                                             (line   73)
* formatdate() (nel modulo email.utils): email utils Miscellaneous utilities.
                                                             (line  152)
* formatday() (calendar.TextCalendar metodo): calendar — General calendar-related functions.
                                                             (line  156)
* FormatError:                           Exceptions<20>.     (line   31)
* FormatError() (nel modulo ctypes):     Utility functions.  (line  169)
* formatException() (logging.Formatter metodo): Formatter Objects.
                                                             (line  116)
* formatFooter() (logging.BufferingFormatter metodo): Formatter Objects.
                                                             (line  147)
* formatHeader() (logging.BufferingFormatter metodo): Formatter Objects.
                                                             (line  140)
* formatmonth() (calendar.HTMLCalendar metodo): calendar — General calendar-related functions.
                                                             (line  229)
* formatmonth() (calendar.TextCalendar metodo): calendar — General calendar-related functions.
                                                             (line  185)
* formatmonthname() (calendar.HTMLCalendar metodo): calendar — General calendar-related functions.
                                                             (line  250)
* formatmonthname() (calendar.TextCalendar metodo): calendar — General calendar-related functions.
                                                             (line  194)
* formatStack() (logging.Formatter metodo): Formatter Objects.
                                                             (line  124)
* formattazione stile printf:            Formattazione delle stringhe in stile printf.
                                                             (line    6)
* formattazione stile printf <1>:        Formattazione Bytes stile printf.
                                                             (line    6)
* formattazione stile sprintf:           Formattazione delle stringhe in stile printf.
                                                             (line    6)
* formattazione stile sprintf <1>:       Formattazione Bytes stile printf.
                                                             (line    6)
* formattazione, stringa (%):            Formattazione delle stringhe in stile printf.
                                                             (line    6)
* formattazione;bytearray (%):           Formattazione Bytes stile printf.
                                                             (line    6)
* formattazione;bytes (%):               Formattazione Bytes stile printf.
                                                             (line    6)
* formatted string literal:              Formattazione Avanzata dell’Output.
                                                             (line   98)
* formatted string literal <1>:          Raw string literals.
                                                             (line   25)
* formatted string literals:             Metodi per le Stringhe.
                                                             (line  912)
* FormattedValue (classe in ast):        Literals<3>.        (line   18)
* Formatter (classe in logging):         Formatter Objects.  (line    6)
* Formatter (classe in string):          Custom String Formatting.
                                                             (line   13)
* formatTime() (logging.Formatter metodo): Formatter Objects.
                                                             (line   76)
* formatwarning() (nel modulo warnings): Available Functions.
                                                             (line  103)
* formatweek() (calendar.TextCalendar metodo): calendar — General calendar-related functions.
                                                             (line  163)
* formatweekday() (calendar.TextCalendar metodo): calendar — General calendar-related functions.
                                                             (line  171)
* formatweekheader() (calendar.TextCalendar metodo): calendar — General calendar-related functions.
                                                             (line  178)
* formatyear() (calendar.HTMLCalendar metodo): calendar — General calendar-related functions.
                                                             (line  235)
* formatyear() (calendar.TextCalendar metodo): calendar — General calendar-related functions.
                                                             (line  208)
* formatyearpage() (calendar.HTMLCalendar metodo): calendar — General calendar-related functions.
                                                             (line  240)
* Fortran contiguous:                    shape strides suboffsets.
                                                             (line   33)
* Fortran contiguous <1>:                Glossary.           (line  390)
* forward() (nel modulo turtle):         Turtle motion.      (line    6)
* FORWARDREF (annotationlib.Format attributo): Classes<4>.   (line   30)
* ForwardRef (classe in annotationlib):  Classes<4>.         (line   49)
* ForwardRef (classe in typing):         Introspection helpers.
                                                             (line  153)
* fp (urllib.error.HTTPError attributo): urllib error — Exception classes raised by urllib request.
                                                             (line   62)
* fpathconf() (nel modulo os):           File Descriptor Operations.
                                                             (line  162)
* Fraction (classe in fractions):        fractions — Rational numbers.
                                                             (line   16)
* Frame (classe in tracemalloc):         Frame.              (line    6)
* frame (inspect.FrameInfo attributo):   The interpreter stack.
                                                             (line   13)
* frame (tkinter.scrolledtext.ScrolledText attributo): tkinter scrolledtext — Scrolled Text Widget.
                                                             (line   26)
* FrameInfo (classe in compression.zstd): Miscellaneous<2>.  (line   12)
* FrameInfo (classe in inspect):         The interpreter stack.
                                                             (line   11)
* FrameSummary (classe in traceback):    FrameSummary Objects.
                                                             (line   11)
* FrameType (nel modulo types):          Standard Interpreter Types.
                                                             (line  198)
* free (C function):                     Overview<4>.        (line   33)
* free threading:                        Glossary.           (line  654)
* free variable:                         Glossary.           (line  661)
* free_tool_id() (nel modulo sys.monitoring): Registering and using tools.
                                                             (line   18)
* free;variable:                         Binding of names.   (line   48)
* freedesktop_os_release() (nel modulo platform): Linux platforms.
                                                             (line    6)
* freefunc (C type):                     Slot Type typedefs. (line   27)
* freeze utility:                        Importing Modules<2>.
                                                             (line  277)
* freeze_support() (nel modulo multiprocessing): Miscellaneous<4>.
                                                             (line   50)
* freeze() (nel modulo gc):              gc — Garbage Collector interface.
                                                             (line  237)
* frexp() (nel modulo math):             Floating point manipulation functions.
                                                             (line   12)
* FRIDAY (nel modulo calendar):          calendar — General calendar-related functions.
                                                             (line  447)
* from_address() (ctypes._CData metodo): Data types.         (line   42)
* from_buffer_copy() (ctypes._CData metodo): Data types.     (line   31)
* from_buffer() (ctypes._CData metodo):  Data types.         (line   19)
* from_bytes() (int metodo della classe): Metodi Aggiuntivi sui Tipi Integer.
                                                             (line  114)
* from_callable() (inspect.Signature metodo della classe): Introspecting callables with the Signature object.
                                                             (line  188)
* from_decimal() (fractions.Fraction metodo della classe): fractions — Rational numbers.
                                                             (line  151)
* from_exception() (traceback.TracebackException metodo della classe): TracebackException Objects.
                                                             (line  126)
* from_file() (zipfile.ZipInfo metodo della classe): ZipInfo objects.
                                                             (line   14)
* from_file() (zoneinfo.ZoneInfo metodo della classe): The ZoneInfo class.
                                                             (line   28)
* from_float() (decimal.Decimal metodo della classe): Decimal objects.
                                                             (line  245)
* from_float() (fractions.Fraction metodo della classe): fractions — Rational numbers.
                                                             (line  140)
* from_iterable() (itertools.chain metodo della classe): Itertool Functions.
                                                             (line  119)
* from_list() (traceback.StackSummary metodo della classe): StackSummary Objects.
                                                             (line   31)
* from_number() (complex metodo della classe): Additional Methods on Complex.
                                                             (line   10)
* from_number() (decimal.Decimal metodo della classe): Decimal objects.
                                                             (line  272)
* from_number() (float metodo della classe): Metodi aggiuntivi su Float.
                                                             (line    9)
* from_number() (fractions.Fraction metodo della classe): fractions — Rational numbers.
                                                             (line  160)
* from_param() (ctypes._CData metodo):   Data types.         (line   51)
* from_samples() (statistics.NormalDist metodo della classe): NormalDist objects.
                                                             (line   45)
* from_traceback() (dis.Bytecode metodo della classe): Bytecode analysis.
                                                             (line   48)
* from_uri() (pathlib.Path metodo della classe): Parsing and generating URIs.
                                                             (line   12)
* from;import statement:                 Binding of names.   (line    9)
* from;import statement <1>:             The import statement.
                                                             (line   52)
* from;yield from expression:            Yield expressions.  (line   66)
* frombuf() (tarfile.TarInfo metodo della classe): TarInfo Objects.
                                                             (line   37)
* frombytes() (array.array metodo):      array — Efficient arrays of numeric values.
                                                             (line  166)
* fromfd() (nel modulo socket):          Creating sockets.   (line  160)
* fromfd() (select.epoll metodo):        Edge and Level Trigger Polling epoll Objects.
                                                             (line   83)
* fromfd() (select.kqueue metodo):       Kqueue Objects.     (line   18)
* fromfile() (array.array metodo):       array — Efficient arrays of numeric values.
                                                             (line  176)
* fromhex() (bytearray metodo della classe): Oggetti Bytearray.
                                                             (line   38)
* fromhex() (bytes metodo della classe): Oggetti bytes.      (line   69)
* fromhex() (float metodo della classe): Metodi aggiuntivi su Float.
                                                             (line   58)
* fromisocalendar() (datetime.date metodo della classe): date Objects.
                                                             (line   91)
* fromisocalendar() (datetime.datetime metodo della classe): datetime Objects.
                                                             (line  246)
* fromisoformat() (datetime.date metodo della classe): date Objects.
                                                             (line   63)
* fromisoformat() (datetime.datetime metodo della classe): datetime Objects.
                                                             (line  197)
* fromisoformat() (datetime.time metodo della classe): time Objects.
                                                             (line  107)
* fromkeys() (collections.Counter metodo): Counter objects.  (line  117)
* fromkeys() (dict metodo della classe): Tipi di Mapping — dict.
                                                             (line  174)
* fromlist() (array.array metodo):       array — Efficient arrays of numeric values.
                                                             (line  184)
* fromordinal() (datetime.date metodo della classe): date Objects.
                                                             (line   54)
* fromordinal() (datetime.datetime metodo della classe): datetime Objects.
                                                             (line  171)
* fromshare() (nel modulo socket):       Creating sockets.   (line  178)
* fromstring() (nel modulo xml.etree.ElementTree): Functions<8>.
                                                             (line   99)
* fromstringlist() (nel modulo xml.etree.ElementTree): Functions<8>.
                                                             (line  107)
* fromtarfile() (tarfile.TarInfo metodo della classe): TarInfo Objects.
                                                             (line   44)
* fromtimestamp() (datetime.date metodo della classe): date Objects.
                                                             (line   35)
* fromtimestamp() (datetime.datetime metodo della classe): datetime Objects.
                                                             (line  100)
* fromunicode() (array.array metodo):    array — Efficient arrays of numeric values.
                                                             (line  190)
* fromutc() (datetime.timezone metodo):  timezone Objects.   (line   61)
* fromutc() (datetime.tzinfo metodo):    tzinfo Objects.     (line  163)
* FrozenImporter (classe in importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line   81)
* FrozenInstanceError:                   Module contents<4>. (line  520)
* frozenset (classe built-in):           Tipi di Insiemi — set frozenset.
                                                             (line   34)
* FrozenSet (classe in typing):          Aliases to built-in types.
                                                             (line   42)
* FS (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line  109)
* fs_is_case_insensitive() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line  104)
* FS_NONASCII (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   11)
* fsdecode() (nel modulo os):            Process Parameters. (line  118)
* fsencode() (nel modulo os):            Process Parameters. (line  105)
* fspath() (nel modulo os):              Process Parameters. (line  131)
* fstat() (nel modulo os):               File Descriptor Operations.
                                                             (line  184)
* fstatvfs() (nel modulo os):            File Descriptor Operations.
                                                             (line  196)
* fstring:                               Formattazione Avanzata dell’Output.
                                                             (line   98)
* fstring <1>:                           Raw string literals.
                                                             (line   25)
* fstring <2>:                           Metodi per le Stringhe.
                                                             (line  912)
* FSTRING_END (nel modulo token):        token — Constants used with Python parse trees.
                                                             (line  116)
* FSTRING_MIDDLE (nel modulo token):     token — Constants used with Python parse trees.
                                                             (line  105)
* FSTRING_START (nel modulo token):      token — Constants used with Python parse trees.
                                                             (line   96)
* fsum() (nel modulo math):              Summation and product functions.
                                                             (line   18)
* fsync() (nel modulo os):               File Descriptor Operations.
                                                             (line  204)
* FTP:                                   urllib request Restrictions.
                                                             (line   37)
* FTP (classe in ftplib):                FTP objects.        (line    6)
* ftp_open() (urllib.request.FTPHandler metodo): FTPHandler Objects.
                                                             (line    6)
* FTP_TLS (classe in ftplib):            FTP_TLS objects.    (line    6)
* FTP;ftplib (standard module):          ftplib — FTP protocol client.
                                                             (line    8)
* FTP;protocol:                          urllib request Restrictions.
                                                             (line    6)
* FTP;protocol <1>:                      ftplib — FTP protocol client.
                                                             (line    8)
* FTPHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  481)
* ftruncate() (nel modulo os):           File Descriptor Operations.
                                                             (line  217)
* Full:                                  queue — A synchronized queue class.
                                                             (line   88)
* FULL (inspect.BufferFlags attributo):  Buffer flags.       (line   45)
* full_match() (pathlib.PurePath metodo): Methods and properties.
                                                             (line  260)
* FULL_RO (inspect.BufferFlags attributo): Buffer flags.     (line   47)
* full_url (urllib.request.Request attributo): Request Objects.
                                                             (line   11)
* full() (asyncio.Queue metodo):         Queue.              (line   31)
* full() (multiprocessing.Queue metodo): Pipes and Queues.   (line  129)
* full() (queue.Queue metodo):           Queue Objects.      (line   22)
* fullmatch() (nel modulo re):           Functions.          (line   67)
* fullmatch() (re.Pattern metodo):       Regular Expression Objects.
                                                             (line   62)
* fully_trusted_filter() (nel modulo tarfile): Default named filters.
                                                             (line    9)
* func (functools.partial attributo):    partial Objects.    (line    9)
* funcname (bdb.Breakpoint attributo):   bdb — Debugger framework.
                                                             (line  101)
* function:                              Glossary.           (line  670)
* Function (classe in pyclbr):           Function Objects.   (line    6)
* Function (classe in symtable):         Examining Symbol Tables.
                                                             (line  122)
* function (inspect.FrameInfo attributo): The interpreter stack.
                                                             (line   27)
* function (inspect.Traceback attributo): The interpreter stack.
                                                             (line   68)
* FUNCTION (symtable.SymbolTableType attributo): Examining Symbol Tables.
                                                             (line   15)
* function annotation:                   Glossary.           (line  678)
* function;annotations:                  Function definitions.
                                                             (line  111)
* function;argument:                     Callable types.     (line    6)
* function;call:                         Callable types.     (line    6)
* function;call <1>:                     Calls.              (line  132)
* function;call <2>:                     Calls.              (line  143)
* function;definition:                   The return statement.
                                                             (line    6)
* function;definition <1>:               Function definitions.
                                                             (line    6)
* function;generator:                    The yield statement.
                                                             (line    6)
* function;name:                         Function definitions.
                                                             (line    6)
* function;name <1>:                     Function definitions.
                                                             (line    6)
* FunctionDef (classe in ast):           Function and class definitions.
                                                             (line    6)
* FunctionTestCase (classe in unittest): Test cases.         (line 1020)
* FunctionType (classe in ast):          Root nodes.         (line   57)
* FunctionType (nel modulo types):       Standard Interpreter Types.
                                                             (line   25)
* funny_files (filecmp.dircmp attributo): The dircmp class.  (line   99)
* funzione built-in;help:                Interfaccia del Sistema Operativo.
                                                             (line   20)
* funzione incorporata;apri:             Lettura e Scrittura di File.
                                                             (line    6)
* funzione incorporata;exec:             Funzioni Incorporate.
                                                             (line  657)
* funzione integrata;compilare:          Oggetti Codice.     (line    6)
* funzione integrata;complex:            Tipi Numerici — int float complex.
                                                             (line   30)
* funzione integrata;eval:               Oggetti Codice.     (line   17)
* funzione integrata;exec:               Oggetti Codice.     (line   17)
* funzione integrata;float:              Tipi Numerici — int float complex.
                                                             (line   30)
* funzione integrata;hash:               Tipi di Sequenza Immutabili.
                                                             (line    6)
* funzione integrata;int:                Tipi Numerici — int float complex.
                                                             (line   30)
* funzione integrata;len:                Operazioni Comuni sulle Sequenze.
                                                             (line   22)
* funzione integrata;len <1>:            Tipi di Mapping — dict.
                                                             (line    6)
* funzione integrata;max:                Operazioni Comuni sulle Sequenze.
                                                             (line   22)
* funzione integrata;min:                Operazioni Comuni sulle Sequenze.
                                                             (line   22)
* funzione integrata;type:               Oggetti Tipo.       (line    6)
* funzione;annotazioni:                  Annotationi delle Funzioni.
                                                             (line    6)
* Future (classe in asyncio):            Future Object.      (line    6)
* Future (classe in concurrent.futures): Future Objects.     (line   10)
* future_add_to_awaited_by() (nel modulo asyncio): Low level utility functions.
                                                             (line   14)
* future_discard_from_awaited_by() (nel modulo asyncio): Low level utility functions.
                                                             (line   26)
* future;statement:                      Future statements.  (line    6)
* FutureWarning:                         Warnings.           (line   55)
* fwalk() (nel modulo os):               Files and Directories.
                                                             (line 1753)
* gaierror:                              Exceptions<17>.     (line   27)
* gamma() (nel modulo math):             Special functions.  (line   29)
* gammavariate() (nel modulo random):    Real-valued distributions.
                                                             (line   48)
* garbage (nel modulo gc):               gc — Garbage Collector interface.
                                                             (line  271)
* garbage collection:                    Objects values and types.
                                                             (line   36)
* garbage collection <1>:                Glossary.           (line  712)
* gather() (curses.textpad.Textbox metodo): Textbox objects. (line  109)
* gather() (nel modulo asyncio):         Running Tasks Concurrently.
                                                             (line    6)
* gauss() (nel modulo random):           Real-valued distributions.
                                                             (line   61)
* gc_collect() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  378)
* gcd() (nel modulo math):               Number-theoretic functions.
                                                             (line   30)
* gcvisitobjects_t (C type):             Querying Garbage Collector State.
                                                             (line   26)
* ge() (nel modulo operator):            operator — Standard operators as functions.
                                                             (line   24)
* generate_tokens() (nel modulo tokenize): Tokenizing Input. (line   38)
* generator:                             Glossary.           (line  721)
* generator <1>:                         Glossary.           (line  721)
* Generator (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   56)
* Generator (classe in email.generator): email generator Generating MIME documents.
                                                             (line  140)
* Generator (classe in typing):          Aliases to other ABCs in collections abc.
                                                             (line   38)
* generator expression:                  Glossary.           (line  743)
* generator expression <1>:              Glossary.           (line  743)
* generator iterator:                    Glossary.           (line  731)
* generator_stop (nel modulo __future__): Module Contents<5>.
                                                             (line   43)
* generator;expression:                  Generator expressions.
                                                             (line    6)
* generator;function:                    Generator functions.
                                                             (line    6)
* generator;function <1>:                Yield expressions.  (line    6)
* generator;function <2>:                The yield statement.
                                                             (line    6)
* generator;iterator:                    Generator functions.
                                                             (line    6)
* generator;iterator <1>:                The yield statement.
                                                             (line    6)
* GeneratorExit:                         Concrete exceptions.
                                                             (line   44)
* GeneratorExp (classe in ast):          Comprehensions.     (line    6)
* generators (nel modulo __future__):    Module Contents<5>. (line   18)
* GeneratorType (nel modulo types):      Standard Interpreter Types.
                                                             (line   37)
* Generic (classe in typing):            Building generic types and type aliases.
                                                             (line   15)
* generic function:                      Glossary.           (line  752)
* generic type:                          Glossary.           (line  760)
* generic_visit() (ast.NodeVisitor metodo): ast helpers.     (line  201)
* generic;special;attribute:             The standard type hierarchy.
                                                             (line   13)
* GenericAlias (classe in types):        Standard Interpreter Types.
                                                             (line  150)
* Generico;Alias:                        Tipo Generic Alias. (line    6)
* genops() (nel modulo pickletools):     Programmatic interface.
                                                             (line   22)
* geometric_mean() (nel modulo statistics): Function details.
                                                             (line   77)
* gestore di contesto:                   Tipi di gestori di contesti.
                                                             (line    6)
* GET_AITER (opcode):                    Python Bytecode Instructions.
                                                             (line  331)
* get_all_breaks() (bdb.Bdb metodo):     bdb — Debugger framework.
                                                             (line  424)
* get_all_start_methods() (nel modulo multiprocessing): Miscellaneous<4>.
                                                             (line   76)
* get_all() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  254)
* get_all() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  365)
* get_all() (wsgiref.headers.Headers metodo): wsgiref headers – WSGI response header tools.
                                                             (line   51)
* GET_ANEXT (opcode):                    Python Bytecode Instructions.
                                                             (line  340)
* get_annotate_from_class_namespace() (nel modulo annotationlib): Functions<11>.
                                                             (line  105)
* get_annotations() (nel modulo annotationlib): Functions<11>.
                                                             (line  118)
* get_annotations() (nel modulo inspect): Classes and functions<2>.
                                                             (line  156)
* get_app() (wsgiref.simple_server.WSGIServer metodo): wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line   69)
* get_archive_formats() (nel modulo shutil): Archiving operations.
                                                             (line   69)
* get_args() (nel modulo typing):        Introspection helpers.
                                                             (line   86)
* get_asyncgen_hooks() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line 1041)
* get_attribute() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  627)
* GET_AWAITABLE (opcode):                Python Bytecode Instructions.
                                                             (line  312)
* get_begidx() (nel modulo readline):    Completion.         (line   40)
* get_blocking() (nel modulo os):        File Descriptor Operations.
                                                             (line  230)
* get_body_encoding() (email.charset.Charset metodo): email charset Representing character sets.
                                                             (line   96)
* get_body() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  518)
* get_boundary() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  403)
* get_boundary() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  583)
* get_bpbynumber() (bdb.Bdb metodo):     bdb — Debugger framework.
                                                             (line  400)
* get_break() (bdb.Bdb metodo):          bdb — Debugger framework.
                                                             (line  409)
* get_breaks() (bdb.Bdb metodo):         bdb — Debugger framework.
                                                             (line  414)
* get_buffer() (asyncio.BufferedProtocol metodo): Buffered Streaming Protocols.
                                                             (line   21)
* get_bytes() (mailbox.Mailbox metodo):  Mailbox objects.    (line  168)
* get_bytes() (mailbox.mbox metodo):     mbox objects.       (line   32)
* get_bytes() (mailbox.MMDF metodo):     MMDF objects.       (line   29)
* get_ca_certs() (ssl.SSLContext metodo): SSL Contexts.      (line  178)
* get_cache_token() (nel modulo abc):    abc — Abstract Base Classes.
                                                             (line  326)
* get_channel_binding() (ssl.SSLSocket metodo): SSL Sockets. (line  262)
* get_charset() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  269)
* get_charsets() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  431)
* get_charsets() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  617)
* get_children() (symtable.SymbolTable metodo): Examining Symbol Tables.
                                                             (line  118)
* get_children() (tkinter.ttk.Treeview metodo): ttk Treeview.
                                                             (line   19)
* get_ciphers() (ssl.SSLContext metodo): SSL Contexts.       (line  192)
* get_clock_info() (nel modulo time):    Functions<4>.       (line  105)
* get_close_matches() (nel modulo difflib): difflib — Helpers for computing deltas.
                                                             (line  205)
* get_code() (importlib.abc.InspectLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  209)
* get_code() (importlib.abc.SourceLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  404)
* get_code() (importlib.machinery.ExtensionFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  334)
* get_code() (importlib.machinery.SourcelessFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  270)
* get_code() (zipimport.zipimporter metodo): zipimporter Objects.
                                                             (line   45)
* get_completer_delims() (nel modulo readline): Completion.  (line   50)
* get_completer() (nel modulo readline): Completion.         (line   29)
* get_completion_type() (nel modulo readline): Completion.   (line   34)
* get_config_h_filename() (nel modulo sysconfig): Other functions<3>.
                                                             (line   64)
* get_config_var() (nel modulo sysconfig): Configuration variables.
                                                             (line   26)
* get_config_vars() (nel modulo sysconfig): Configuration variables.
                                                             (line   16)
* get_content_charset() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  424)
* get_content_charset() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  606)
* get_content_disposition() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  455)
* get_content_disposition() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  631)
* get_content_maintype() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  324)
* get_content_maintype() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  435)
* get_content_subtype() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  330)
* get_content_subtype() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  441)
* get_content_type() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  308)
* get_content_type() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  419)
* get_content() (email.contentmanager.ContentManager metodo): email contentmanager Managing MIME Content.
                                                             (line   19)
* get_content() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  582)
* get_content() (nel modulo email.contentmanager): Content Manager Instances.
                                                             (line   24)
* get_context() (asyncio.Handle metodo): Callback Handles.   (line   11)
* get_context() (asyncio.Task metodo):   Task Object.        (line  170)
* get_context() (nel modulo multiprocessing): Miscellaneous<4>.
                                                             (line   85)
* get_coro() (asyncio.Task metodo):      Task Object.        (line  157)
* get_coroutine_origin_tracking_depth() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line 1055)
* get_count() (nel modulo gc):           gc — Garbage Collector interface.
                                                             (line  147)
* get_current_history_length() (nel modulo readline): History list.
                                                             (line   14)
* get_current() (nel modulo concurrent.interpreters): Reference<4>.
                                                             (line   13)
* get_data() (importlib.abc.FileLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  326)
* get_data() (importlib.abc.ResourceLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  189)
* get_data() (nel modulo pkgutil):       pkgutil — Package extension utility.
                                                             (line  147)
* get_data() (zipimport.zipimporter metodo): zipimporter Objects.
                                                             (line   50)
* get_date() (mailbox.MaildirMessage metodo): MaildirMessage objects.
                                                             (line   92)
* get_debug() (asyncio.loop metodo):     Enabling debug mode.
                                                             (line    6)
* get_debug() (nel modulo gc):           gc — Garbage Collector interface.
                                                             (line   70)
* get_default_backend() (nel modulo pdb): Command-line interface<8>.
                                                             (line  169)
* get_default_scheme() (nel modulo sysconfig): Installation path functions.
                                                             (line   14)
* get_default_type() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  335)
* get_default_type() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  446)
* get_default_verify_paths() (nel modulo ssl): Certificate handling.
                                                             (line   62)
* get_default() (argparse.ArgumentParser metodo): Parser defaults.
                                                             (line   35)
* get_dialect() (nel modulo csv):        Module Contents<3>. (line   86)
* get_disassembly_as_string() (test.support.bytecode_helper.BytecodeTestCase metodo): test support bytecode_helper — Support tools for testing correct bytecode generation.
                                                             (line   18)
* get_docstring() (nel modulo ast):      ast helpers.        (line  122)
* get_doctest() (doctest.DocTestParser metodo): DocTestParser objects.
                                                             (line   13)
* get_endidx() (nel modulo readline):    Completion.         (line   40)
* get_environ() (wsgiref.simple_server.WSGIRequestHandler metodo): wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line   91)
* get_errno() (nel modulo ctypes):       Utility functions.  (line  185)
* get_escdelay() (nel modulo curses):    Functions<5>.       (line  464)
* get_event_loop_policy() (nel modulo asyncio): Getting and Setting the Policy.
                                                             (line    9)
* get_event_loop() (asyncio.AbstractEventLoopPolicy metodo): Policy Objects.
                                                             (line   12)
* get_event_loop() (nel modulo asyncio): Event Loop.         (line   39)
* get_events() (nel modulo sys.monitoring): Setting events globally.
                                                             (line    9)
* get_examples() (doctest.DocTestParser metodo): DocTestParser objects.
                                                             (line   22)
* get_exception_handler() (asyncio.loop metodo): Error Handling API.
                                                             (line   27)
* get_exec_path() (nel modulo os):       Process Parameters. (line  190)
* get_extra_info() (asyncio.BaseTransport metodo): Base Transport.
                                                             (line   21)
* get_extra_info() (asyncio.StreamWriter metodo): StreamWriter.
                                                             (line   64)
* get_field() (string.Formatter metodo): Custom String Formatting.
                                                             (line   57)
* get_file_breaks() (bdb.Bdb metodo):    bdb — Debugger framework.
                                                             (line  419)
* get_file() (mailbox.Babyl metodo):     Babyl objects.      (line   49)
* get_file() (mailbox.Mailbox metodo):   Mailbox objects.    (line  184)
* get_file() (mailbox.Maildir metodo):   Maildir objects.    (line  221)
* get_file() (mailbox.mbox metodo):      mbox objects.       (line   39)
* get_file() (mailbox.MH metodo):        MH objects.         (line   96)
* get_file() (mailbox.MMDF metodo):      MMDF objects.       (line   36)
* get_filename() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  393)
* get_filename() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  573)
* get_filename() (importlib.abc.ExecutionLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  281)
* get_filename() (importlib.abc.FileLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  322)
* get_filename() (importlib.machinery.ExtensionFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  342)
* get_filename() (zipimport.zipimporter metodo): zipimporter Objects.
                                                             (line   58)
* get_filter() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line  106)
* get_flags() (mailbox.Maildir metodo):  Maildir objects.    (line   92)
* get_flags() (mailbox.MaildirMessage metodo): MaildirMessage objects.
                                                             (line   63)
* get_flags() (mailbox.mboxMessage metodo): mboxMessage objects.
                                                             (line   64)
* get_flags() (mailbox.MMDFMessage metodo): MMDFMessage objects.
                                                             (line   63)
* get_folder() (mailbox.Maildir metodo): Maildir objects.    (line   69)
* get_folder() (mailbox.MH metodo):      MH objects.         (line   39)
* get_frame_info() (nel modulo compression.zstd): Miscellaneous<2>.
                                                             (line    6)
* get_frees() (symtable.Function metodo): Examining Symbol Tables.
                                                             (line  145)
* get_freeze_count() (nel modulo gc):    gc — Garbage Collector interface.
                                                             (line  262)
* get_from() (mailbox.mboxMessage metodo): mboxMessage objects.
                                                             (line   47)
* get_from() (mailbox.MMDFMessage metodo): MMDFMessage objects.
                                                             (line   46)
* get_full_url() (urllib.request.Request metodo): Request Objects.
                                                             (line  107)
* get_globals() (symtable.Function metodo): Examining Symbol Tables.
                                                             (line  136)
* get_grouped_opcodes() (difflib.SequenceMatcher metodo): SequenceMatcher Objects.
                                                             (line  168)
* get_handle_inheritable() (nel modulo os): Inheritance of File Descriptors.
                                                             (line   36)
* get_header() (urllib.request.Request metodo): Request Objects.
                                                             (line  121)
* get_history_item() (nel modulo readline): History list.    (line   20)
* get_history_length() (nel modulo readline): History file.  (line   40)
* get_id() (symtable.SymbolTable metodo): Examining Symbol Tables.
                                                             (line   69)
* get_ident() (nel modulo _thread):      _thread — Low-level threading API.
                                                             (line   88)
* get_ident() (nel modulo threading):    Reference<2>.       (line   73)
* get_identifiers() (string.Template metodo): Template strings $-strings.
                                                             (line   85)
* get_identifiers() (symtable.SymbolTable metodo): Examining Symbol Tables.
                                                             (line  103)
* get_importer() (nel modulo pkgutil):   pkgutil — Package extension utility.
                                                             (line   55)
* get_info() (mailbox.Maildir metodo):   Maildir objects.    (line  155)
* get_info() (mailbox.MaildirMessage metodo): MaildirMessage objects.
                                                             (line  102)
* get_inheritable() (nel modulo os):     Inheritance of File Descriptors.
                                                             (line   27)
* get_inheritable() (socket.socket metodo): Socket Objects.  (line  128)
* get_instructions() (nel modulo dis):   Analysis functions. (line  146)
* get_int_max_str_digits() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line  851)
* get_interpreter() (nel modulo zipapp): Python API.         (line   83)
* GET_ITER (opcode):                     Python Bytecode Instructions.
                                                             (line  228)
* get_key() (selectors.BaseSelector metodo): Classes<3>.     (line  145)
* get_labels() (mailbox.Babyl metodo):   Babyl objects.      (line   35)
* get_labels() (mailbox.BabylMessage metodo): BabylMessage objects.
                                                             (line   47)
* get_last_error() (nel modulo ctypes):  Utility functions.  (line  193)
* GET_LEN (opcode):                      Python Bytecode Instructions.
                                                             (line  509)
* get_line_buffer() (nel modulo readline): Line buffer.      (line    8)
* get_lineno() (symtable.SymbolTable metodo): Examining Symbol Tables.
                                                             (line   85)
* get_local_events() (nel modulo sys.monitoring): Per code object events.
                                                             (line   11)
* get_locals() (symtable.Function metodo): Examining Symbol Tables.
                                                             (line  132)
* get_logger() (nel modulo multiprocessing): Logging<2>.     (line   11)
* get_loop() (asyncio.Future metodo):    Future Object.      (line  136)
* get_loop() (asyncio.Runner metodo):    Runner context manager.
                                                             (line   65)
* get_loop() (asyncio.Server metodo):    Server Objects.     (line   69)
* get_main() (nel modulo concurrent.interpreters): Reference<4>.
                                                             (line   18)
* get_makefile_filename() (nel modulo sysconfig): Other functions<3>.
                                                             (line   68)
* get_map() (selectors.BaseSelector metodo): Classes<3>.     (line  153)
* get_matching_blocks() (difflib.SequenceMatcher metodo): SequenceMatcher Objects.
                                                             (line  107)
* get_message() (mailbox.Mailbox metodo): Mailbox objects.   (line  161)
* get_method() (urllib.request.Request metodo): Request Objects.
                                                             (line   69)
* get_methods() (symtable.Class metodo): Examining Symbol Tables.
                                                             (line  155)
* get_mixed_type_key() (nel modulo ipaddress): Other Module Level Functions.
                                                             (line   56)
* get_name() (asyncio.Task metodo):      Task Object.        (line  177)
* get_name() (symtable.Symbol metodo):   Examining Symbol Tables.
                                                             (line  199)
* get_name() (symtable.SymbolTable metodo): Examining Symbol Tables.
                                                             (line   73)
* get_namespace() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  310)
* get_namespaces() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  306)
* get_native_id() (nel modulo _thread):  _thread — Low-level threading API.
                                                             (line   96)
* get_native_id() (nel modulo threading): Reference<2>.      (line   83)
* get_nonlocals() (symtable.Function metodo): Examining Symbol Tables.
                                                             (line  140)
* get_nonstandard_attr() (http.cookiejar.Cookie metodo): Cookie Objects<2>.
                                                             (line  102)
* get_nowait() (asyncio.Queue metodo):   Queue.              (line   48)
* get_nowait() (multiprocessing.Queue metodo): Pipes and Queues.
                                                             (line  170)
* get_nowait() (queue.Queue metodo):     Queue Objects.      (line   66)
* get_nowait() (queue.SimpleQueue metodo): SimpleQueue Objects.
                                                             (line   51)
* get_object_traceback() (nel modulo tracemalloc): Functions<10>.
                                                             (line   12)
* get_objects() (nel modulo gc):         gc — Garbage Collector interface.
                                                             (line   74)
* get_opcodes() (difflib.SequenceMatcher metodo): SequenceMatcher Objects.
                                                             (line  125)
* get_option_group() (optparse.OptionParser metodo): Grouping Options.
                                                             (line  103)
* get_option() (optparse.OptionParser metodo): Querying and manipulating your option parser.
                                                             (line   37)
* get_origin() (nel modulo typing):      Introspection helpers.
                                                             (line   63)
* get_original_bases() (nel modulo types): Dynamic Type Creation.
                                                             (line   72)
* get_original_stdout() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  335)
* get_osfhandle() (nel modulo msvcrt):   File Operations.    (line   58)
* get_output_charset() (email.charset.Charset metodo): email charset Representing character sets.
                                                             (line  111)
* get_overloads() (nel modulo typing):   Functions and decorators.
                                                             (line  286)
* get_pagesize() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  302)
* get_param() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  481)
* get_parameters() (symtable.Function metodo): Examining Symbol Tables.
                                                             (line  127)
* get_params() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  460)
* get_path_names() (nel modulo sysconfig): Installation path functions.
                                                             (line   57)
* get_path() (nel modulo sysconfig):     Installation path functions.
                                                             (line   62)
* get_paths() (nel modulo sysconfig):    Installation path functions.
                                                             (line   93)
* get_payload() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  181)
* get_pid() (asyncio.SubprocessTransport metodo): Subprocess Transports.
                                                             (line    6)
* get_pipe_transport() (asyncio.SubprocessTransport metodo): Subprocess Transports.
                                                             (line   10)
* get_platform() (nel modulo sysconfig): Other functions<3>. (line   11)
* get_poly() (nel modulo turtle):        Special Turtle methods.
                                                             (line   29)
* get_preferred_scheme() (nel modulo sysconfig): Installation path functions.
                                                             (line   24)
* get_protocol_members() (nel modulo typing): Introspection helpers.
                                                             (line  104)
* get_protocol() (asyncio.BaseTransport metodo): Base Transport.
                                                             (line   88)
* get_proxy_response_headers() (http.client.HTTPConnection metodo): HTTPConnection Objects.
                                                             (line  140)
* get_python_version() (nel modulo sysconfig): Other functions<3>.
                                                             (line    6)
* get_ready() (graphlib.TopologicalSorter metodo): graphlib — Functionality to operate with graph-like structures.
                                                             (line  158)
* get_referents() (nel modulo gc):       gc — Garbage Collector interface.
                                                             (line  179)
* get_referrers() (nel modulo gc):       gc — Garbage Collector interface.
                                                             (line  157)
* get_request() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line  135)
* get_resource_value() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  268)
* get_returncode() (asyncio.SubprocessTransport metodo): Subprocess Transports.
                                                             (line   29)
* get_running_loop() (nel modulo asyncio): Event Loop.       (line   29)
* get_scheme_names() (nel modulo sysconfig): Installation path functions.
                                                             (line    9)
* get_scheme() (wsgiref.handlers.BaseHandler metodo): wsgiref handlers – server/gateway base classes.
                                                             (line  192)
* get_selection() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line  110)
* get_sequences() (mailbox.MH metodo):   MH objects.         (line   56)
* get_sequences() (mailbox.MHMessage metodo): MHMessage objects.
                                                             (line   32)
* get_server_certificate() (nel modulo ssl): Certificate handling.
                                                             (line   29)
* get_server() (multiprocessing.managers.BaseManager metodo): Managers.
                                                             (line   65)
* get_shapepoly() (nel modulo turtle):   Appearance.         (line  169)
* get_source_segment() (nel modulo ast): ast helpers.        (line  133)
* get_source() (importlib.abc.InspectLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  223)
* get_source() (importlib.abc.SourceLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  422)
* get_source() (importlib.machinery.ExtensionFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  338)
* get_source() (importlib.machinery.SourcelessFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  275)
* get_source() (zipimport.zipimporter metodo): zipimporter Objects.
                                                             (line   66)
* get_stack() (asyncio.Task metodo):     Task Object.        (line  121)
* get_stack() (bdb.Bdb metodo):          bdb — Debugger framework.
                                                             (line  453)
* get_start_method() (nel modulo multiprocessing): Miscellaneous<4>.
                                                             (line  100)
* get_starttag_text() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line   32)
* get_stats_profile() (pstats.Stats metodo): The Stats Class.
                                                             (line  225)
* get_stats() (nel modulo gc):           gc — Garbage Collector interface.
                                                             (line   93)
* get_stderr() (wsgiref.handlers.BaseHandler metodo): wsgiref handlers – server/gateway base classes.
                                                             (line  129)
* get_stderr() (wsgiref.simple_server.WSGIRequestHandler metodo): wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line  101)
* get_stdin() (wsgiref.handlers.BaseHandler metodo): wsgiref handlers – server/gateway base classes.
                                                             (line  123)
* get_string() (mailbox.Mailbox metodo): Mailbox objects.    (line  176)
* get_string() (mailbox.mbox metodo):    mbox objects.       (line   50)
* get_subdir() (mailbox.MaildirMessage metodo): MaildirMessage objects.
                                                             (line   47)
* get_symbols() (symtable.SymbolTable metodo): Examining Symbol Tables.
                                                             (line  113)
* get_tabsize() (nel modulo curses):     Functions<5>.       (line  479)
* get_task_factory() (asyncio.loop metodo): Creating Futures and Tasks.
                                                             (line   80)
* get_terminal_size() (nel modulo os):   Querying the size of a terminal.
                                                             (line    8)
* get_terminal_size() (nel modulo shutil): Querying the size of the output terminal.
                                                             (line    6)
* get_threshold() (nel modulo gc):       gc — Garbage Collector interface.
                                                             (line  152)
* get_token() (shlex.shlex metodo):      shlex Objects.      (line    8)
* get_tool() (nel modulo sys.monitoring): Registering and using tools.
                                                             (line   23)
* get_traceback_limit() (nel modulo tracemalloc): Functions<10>.
                                                             (line   22)
* get_traced_memory() (nel modulo tracemalloc): Functions<10>.
                                                             (line   32)
* get_tracemalloc_memory() (nel modulo tracemalloc): Functions<10>.
                                                             (line   56)
* get_type_hints() (nel modulo typing):  Introspection helpers.
                                                             (line    6)
* get_type() (symtable.SymbolTable metodo): Examining Symbol Tables.
                                                             (line   53)
* get_unixfrom() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  152)
* get_unixfrom() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  163)
* get_unpack_formats() (nel modulo shutil): Archiving operations.
                                                             (line  199)
* get_unverified_chain() (ssl.SSLSocket metodo): SSL Sockets.
                                                             (line  226)
* get_usage() (optparse.OptionParser metodo): Other methods. (line   22)
* get_value() (multiprocessing.Semaphore metodo): Synchronization primitives.
                                                             (line  218)
* get_value() (string.Formatter metodo): Custom String Formatting.
                                                             (line   69)
* get_verified_chain() (ssl.SSLSocket metodo): SSL Sockets.  (line  217)
* get_version() (optparse.OptionParser metodo): Printing a version string.
                                                             (line   34)
* get_visible() (mailbox.BabylMessage metodo): BabylMessage objects.
                                                             (line   63)
* get_wch() (curses.window metodo):      Window Objects.     (line  243)
* get_write_buffer_limits() (asyncio.WriteTransport metodo): Write-only Transports.
                                                             (line   23)
* get_write_buffer_size() (asyncio.WriteTransport metodo): Write-only Transports.
                                                             (line   19)
* GET_YIELD_FROM_ITER (opcode):          Python Bytecode Instructions.
                                                             (line  232)
* get() (asyncio.Queue metodo):          Queue.              (line   39)
* get() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  224)
* get() (contextvars.Context metodo):    Manual Context Management.
                                                             (line  118)
* get() (contextvars.ContextVar metodo): Context Variables.  (line   30)
* get() (dict metodo):                   Tipi di Mapping — dict.
                                                             (line  186)
* get() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  245)
* get() (email.message.Message metodo):  email message Message Representing an email message using the compat32 API.
                                                             (line  357)
* get() (mailbox.Mailbox metodo):        Mailbox objects.    (line  149)
* get() (multiprocessing.pool.AsyncResult metodo): Process Pools.
                                                             (line  204)
* get() (multiprocessing.Queue metodo):  Pipes and Queues.   (line  155)
* get() (multiprocessing.SimpleQueue metodo): Pipes and Queues.
                                                             (line  249)
* get() (nel modulo webbrowser):         Command-line interface<6>.
                                                             (line   68)
* get() (queue.Queue metodo):            Queue Objects.      (line   46)
* get() (queue.SimpleQueue metodo):      SimpleQueue Objects.
                                                             (line   40)
* get() (tkinter.ttk.Combobox metodo):   ttk Combobox.       (line   15)
* get() (tkinter.ttk.Spinbox metodo):    ttk Spinbox.        (line    8)
* get() (types.MappingProxyType metodo): Standard Interpreter Types.
                                                             (line  264)
* get() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line   64)
* getacl() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line  106)
* getaddresses() (nel modulo email.utils): email utils Miscellaneous utilities.
                                                             (line   85)
* getaddrinfo() (asyncio.loop metodo):   DNS.                (line    6)
* getaddrinfo() (nel modulo socket):     Other functions<2>. (line   17)
* getallocatedblocks() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line  757)
* getandroidapilevel() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line  778)
* getannotation() (imaplib.IMAP4 metodo): IMAP4 Objects.     (line  111)
* getargvalues() (nel modulo inspect):   Classes and functions<2>.
                                                             (line   62)
* getasyncgenlocals() (nel modulo inspect): Current State of Generators Coroutines and Asynchronous Generators.
                                                             (line  100)
* getasyncgenstate() (nel modulo inspect): Current State of Generators Coroutines and Asynchronous Generators.
                                                             (line   47)
* getatime() (nel modulo os.path):       os path — Common pathname manipulations.
                                                             (line  172)
* getattr_static() (nel modulo inspect): Fetching attributes statically.
                                                             (line   16)
* getattrfunc (C type):                  Slot Type typedefs. (line   43)
* getAttribute() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   31)
* getAttributeNode() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   37)
* getAttributeNodeNS() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   47)
* getAttributeNS() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   41)
* getattrofunc (C type):                 Slot Type typedefs. (line   54)
* GetBase() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line   31)
* getbegyx() (curses.window metodo):     Window Objects.     (line  227)
* getbkgd() (curses.window metodo):      Window Objects.     (line  231)
* getblocking() (socket.socket metodo):  Socket Objects.     (line  165)
* getboolean() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  258)
* getbuffer() (io.BytesIO metodo):       Buffered Streams.   (line   22)
* getbufferproc (C type):                Slot Type typedefs. (line   98)
* getByteStream() (xml.sax.xmlreader.InputSource metodo): InputSource Objects.
                                                             (line   48)
* getcallargs() (nel modulo inspect):    Classes and functions<2>.
                                                             (line   92)
* getcanvas() (nel modulo turtle):       Settings and special methods.
                                                             (line   55)
* getch() (curses.window metodo):        Window Objects.     (line  236)
* getch() (nel modulo msvcrt):           Console I/O.        (line   11)
* getCharacterStream() (xml.sax.xmlreader.InputSource metodo): InputSource Objects.
                                                             (line   64)
* getche() (nel modulo msvcrt):          Console I/O.        (line   26)
* getChild() (logging.Logger metodo):    Logger Objects.     (line  162)
* getChildren() (logging.Logger metodo): Logger Objects.     (line  174)
* getclasstree() (nel modulo inspect):   Classes and functions<2>.
                                                             (line    6)
* getclosurevars() (nel modulo inspect): Classes and functions<2>.
                                                             (line  123)
* getcode() (http.client.HTTPResponse metodo): HTTPResponse Objects.
                                                             (line   89)
* getcode() (urllib.response.addinfourl metodo): urllib response — Response classes used by urllib.
                                                             (line   45)
* getColumnNumber() (xml.sax.xmlreader.Locator metodo): Locator Objects.
                                                             (line    8)
* getcomments() (nel modulo inspect):    Retrieving source code.
                                                             (line   18)
* getcompname() (wave.Wave_read metodo): Wave_read Objects.  (line   41)
* getcomptype() (wave.Wave_read metodo): Wave_read Objects.  (line   36)
* getconfig() (sqlite3.Connection metodo): Connection objects.
                                                             (line  649)
* getContentHandler() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   21)
* getcontext() (nel modulo decimal):     Context objects.    (line   14)
* getcoroutinelocals() (nel modulo inspect): Current State of Generators Coroutines and Asynchronous Generators.
                                                             (line   92)
* getcoroutinestate() (nel modulo inspect): Current State of Generators Coroutines and Asynchronous Generators.
                                                             (line   28)
* getctime() (nel modulo os.path):       os path — Common pathname manipulations.
                                                             (line  188)
* getcwd() (nel modulo os):              Files and Directories.
                                                             (line  294)
* getcwdb() (nel modulo os):             Files and Directories.
                                                             (line  298)
* getdecoder() (nel modulo codecs):      codecs — Codec registry and base classes.
                                                             (line  116)
* getdefaultencoding() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line  789)
* getdefaultlocale() (nel modulo locale): locale — Internationalization services.
                                                             (line  360)
* getdefaulttimeout() (nel modulo socket): Other functions<2>.
                                                             (line  375)
* getdlopenflags() (nel modulo sys):     sys — System-specific parameters and functions.
                                                             (line  794)
* getdoc() (nel modulo inspect):         Retrieving source code.
                                                             (line    6)
* getDOMImplementation() (nel modulo xml.dom): Module Contents<4>.
                                                             (line   17)
* getDTDHandler() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   30)
* getEffectiveLevel() (logging.Logger metodo): Logger Objects.
                                                             (line  152)
* getegid() (nel modulo os):             Process Parameters. (line  200)
* getElementsByTagName() (xml.dom.Document metodo): Document Objects.
                                                             (line   61)
* getElementsByTagName() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   14)
* getElementsByTagNameNS() (xml.dom.Document metodo): Document Objects.
                                                             (line   66)
* getElementsByTagNameNS() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   18)
* getencoder() (nel modulo codecs):      codecs — Codec registry and base classes.
                                                             (line  108)
* getencoding() (nel modulo locale):     locale — Internationalization services.
                                                             (line  424)
* getEncoding() (xml.sax.xmlreader.InputSource metodo): InputSource Objects.
                                                             (line   32)
* getEntityResolver() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   39)
* getenv() (nel modulo os):              Process Parameters. (line  158)
* getenvb() (nel modulo os):             Process Parameters. (line  174)
* getErrorHandler() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   50)
* geteuid() (nel modulo os):             Process Parameters. (line  208)
* getEvent() (xml.dom.pulldom.DOMEventStream metodo): DOMEventStream Objects.
                                                             (line   11)
* getEventCategory() (logging.handlers.NTEventLogHandler metodo): NTEventLogHandler.
                                                             (line   43)
* getEventType() (logging.handlers.NTEventLogHandler metodo): NTEventLogHandler.
                                                             (line   49)
* getException() (xml.sax.SAXException metodo): SAXException Objects.
                                                             (line   13)
* getFeature() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   69)
* getfile() (nel modulo inspect):        Retrieving source code.
                                                             (line   27)
* getFilesToDelete() (logging.handlers.TimedRotatingFileHandler metodo): TimedRotatingFileHandler.
                                                             (line  115)
* getfilesystemencodeerrors() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line  834)
* getfilesystemencoding() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line  803)
* getfirstweekday() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line   48)
* getfloat() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  251)
* getfqdn() (nel modulo socket):         Other functions<2>. (line   99)
* getframeinfo() (nel modulo inspect):   The interpreter stack.
                                                             (line  125)
* getframerate() (wave.Wave_read metodo): Wave_read Objects. (line   28)
* getfullargspec() (nel modulo inspect): Classes and functions<2>.
                                                             (line   17)
* getgeneratorlocals() (nel modulo inspect): Current State of Generators Coroutines and Asynchronous Generators.
                                                             (line   72)
* getgeneratorstate() (nel modulo inspect): Current State of Generators Coroutines and Asynchronous Generators.
                                                             (line   12)
* getgid() (nel modulo os):              Process Parameters. (line  214)
* getgrall() (nel modulo grp):           grp — The group database.
                                                             (line   58)
* getgrgid() (nel modulo grp):           grp — The group database.
                                                             (line   44)
* getgrnam() (nel modulo grp):           grp — The group database.
                                                             (line   53)
* getgrouplist() (nel modulo os):        Process Parameters. (line  223)
* getgroups() (nel modulo os):           Process Parameters. (line  234)
* getHandlerByName() (nel modulo logging): Module-Level Functions.
                                                             (line  183)
* getHandlerNames() (nel modulo logging): Module-Level Functions.
                                                             (line  190)
* getheader() (http.client.HTTPResponse metodo): HTTPResponse Objects.
                                                             (line   24)
* getheaders() (http.client.HTTPResponse metodo): HTTPResponse Objects.
                                                             (line   32)
* gethostbyaddr() (in module socket):    Process Parameters. (line  576)
* gethostbyaddr() (nel modulo socket):   Other functions<2>. (line  156)
* gethostbyname_ex() (nel modulo socket): Other functions<2>.
                                                             (line  126)
* gethostbyname() (nel modulo socket):   Other functions<2>. (line  111)
* gethostname() (in module socket):      Process Parameters. (line  576)
* gethostname() (nel modulo socket):     Other functions<2>. (line  143)
* getincrementaldecoder() (nel modulo codecs): codecs — Codec registry and base classes.
                                                             (line  132)
* getincrementalencoder() (nel modulo codecs): codecs — Codec registry and base classes.
                                                             (line  124)
* getinfo() (zipfile.ZipFile metodo):    ZipFile objects.    (line  117)
* getinnerframes() (nel modulo inspect): The interpreter stack.
                                                             (line  148)
* GetInputContext() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line   37)
* getint() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  244)
* getitem() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  208)
* getiterfunc (C type):                  Slot Type typedefs. (line   86)
* getitimer() (nel modulo signal):       Module contents<2>. (line  464)
* getkey() (curses.window metodo):       Window Objects.     (line  251)
* GetLastError() (nel modulo ctypes):    Utility functions.  (line  177)
* getLength() (xml.sax.xmlreader.Attributes metodo): The Attributes Interface.
                                                             (line   11)
* getLevelName() (nel modulo logging):   Module-Level Functions.
                                                             (line  150)
* getLevelNamesMapping() (nel modulo logging): Module-Level Functions.
                                                             (line  141)
* getlimit() (sqlite3.Connection metodo): Connection objects.
                                                             (line  593)
* getline() (nel modulo linecache):      linecache — Random access to text lines.
                                                             (line   23)
* getLineNumber() (xml.sax.xmlreader.Locator metodo): Locator Objects.
                                                             (line   12)
* getloadavg() (nel modulo os):          Miscellaneous System Information.
                                                             (line   52)
* getlocale() (nel modulo locale):       locale — Internationalization services.
                                                             (line  387)
* getLogger() (nel modulo logging):      Module-Level Functions.
                                                             (line    9)
* getLoggerClass() (nel modulo logging): Module-Level Functions.
                                                             (line   23)
* getlogin() (nel modulo os):            Process Parameters. (line  257)
* getLogRecordFactory() (nel modulo logging): Module-Level Functions.
                                                             (line   34)
* getMandatoryRelease() (__future__._Feature metodo): Module Contents<5>.
                                                             (line   77)
* getmark() (wave.Wave_read metodo):     Wave_read Objects.  (line   72)
* getmarkers() (wave.Wave_read metodo):  Wave_read Objects.  (line   64)
* getmaxyx() (curses.window metodo):     Window Objects.     (line  258)
* getmember() (tarfile.TarFile metodo):  TarFile Objects.    (line  103)
* getmembers_static() (nel modulo inspect): Types and members.
                                                             (line  377)
* getmembers() (nel modulo inspect):     Types and members.  (line  364)
* getmembers() (tarfile.TarFile metodo): TarFile Objects.    (line  111)
* getMessage() (logging.LogRecord metodo): LogRecord Objects.
                                                             (line   64)
* getMessage() (xml.sax.SAXException metodo): SAXException Objects.
                                                             (line    9)
* getMessageID() (logging.handlers.NTEventLogHandler metodo): NTEventLogHandler.
                                                             (line   60)
* getmodule() (nel modulo inspect):      Retrieving source code.
                                                             (line   33)
* getmodulename() (nel modulo inspect):  Types and members.  (line  393)
* getmouse() (nel modulo curses):        Functions<5>.       (line  160)
* getmro() (nel modulo inspect):         Classes and functions<2>.
                                                             (line   84)
* getmtime() (nel modulo os.path):       os path — Common pathname manipulations.
                                                             (line  179)
* getName() (threading.Thread metodo):   Thread objects.     (line  197)
* getNameByQName() (xml.sax.xmlreader.AttributesNS metodo): The AttributesNS Interface.
                                                             (line   16)
* getnameinfo() (asyncio.loop metodo):   DNS.                (line   11)
* getnameinfo() (nel modulo socket):     Other functions<2>. (line  172)
* getnames() (tarfile.TarFile metodo):   TarFile Objects.    (line  117)
* getNames() (xml.sax.xmlreader.Attributes metodo): The Attributes Interface.
                                                             (line   15)
* getnchannels() (wave.Wave_read metodo): Wave_read Objects. (line   19)
* getnframes() (wave.Wave_read metodo):  Wave_read Objects.  (line   32)
* getnode() (nel modulo uuid):           uuid — UUID objects according to RFC 9562.
                                                             (line  177)
* getobjects() (nel modulo sys):         sys — System-specific parameters and functions.
                                                             (line  948)
* getopt() (nel modulo getopt):          getopt — C-style parser for command line options.
                                                             (line   33)
* GetoptError:                           getopt — C-style parser for command line options.
                                                             (line   97)
* getOptionalRelease() (__future__._Feature metodo): Module Contents<5>.
                                                             (line   72)
* getouterframes() (nel modulo inspect): The interpreter stack.
                                                             (line  133)
* getoutput() (nel modulo subprocess):   Legacy Shell Invocation Functions.
                                                             (line   45)
* getpagesize() (nel modulo resource):   Resource Usage.     (line  101)
* getparams() (wave.Wave_read metodo):   Wave_read Objects.  (line   46)
* getparyx() (curses.window metodo):     Window Objects.     (line  262)
* getpass() (nel modulo getpass):        getpass — Portable password input.
                                                             (line   17)
* GetPassWarning:                        getpass — Portable password input.
                                                             (line   50)
* getpeercert() (ssl.SSLSocket metodo):  SSL Sockets.        (line  148)
* getpeername() (socket.socket metodo):  Socket Objects.     (line  136)
* getpen() (nel modulo turtle):          Special Turtle methods.
                                                             (line   52)
* getpgid() (nel modulo os):             Process Parameters. (line  268)
* getpgrp() (nel modulo os):             Process Parameters. (line  276)
* getpid() (nel modulo os):              Process Parameters. (line  282)
* getpos() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line   28)
* getppid() (nel modulo os):             Process Parameters. (line  289)
* getpreferredencoding() (nel modulo locale): locale — Internationalization services.
                                                             (line  399)
* getpriority() (nel modulo os):         Process Parameters. (line  300)
* getprofile() (nel modulo sys):         sys — System-specific parameters and functions.
                                                             (line  973)
* getprofile() (nel modulo threading):   Reference<2>.       (line  152)
* getProperty() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   83)
* getprotobyname() (nel modulo socket):  Other functions<2>. (line  192)
* getproxies() (nel modulo urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  210)
* getPublicId() (xml.sax.xmlreader.InputSource metodo): InputSource Objects.
                                                             (line   10)
* getPublicId() (xml.sax.xmlreader.Locator metodo): Locator Objects.
                                                             (line   16)
* getpwall() (nel modulo pwd):           pwd — The password database.
                                                             (line   63)
* getpwnam() (nel modulo pwd):           pwd — The password database.
                                                             (line   59)
* getpwuid() (nel modulo pwd):           pwd — The password database.
                                                             (line   55)
* getQNameByName() (xml.sax.xmlreader.AttributesNS metodo): The AttributesNS Interface.
                                                             (line   20)
* getQNames() (xml.sax.xmlreader.AttributesNS metodo): The AttributesNS Interface.
                                                             (line   24)
* getquota() (imaplib.IMAP4 metodo):     IMAP4 Objects.      (line  116)
* getquotaroot() (imaplib.IMAP4 metodo): IMAP4 Objects.      (line  121)
* getrandbits() (nel modulo random):     Functions for integers.
                                                             (line   37)
* getrandbits() (random.Random metodo):  Alternative Generator.
                                                             (line   42)
* getrandom() (nel modulo os):           Random numbers<2>.  (line    6)
* getreader() (nel modulo codecs):       codecs — Codec registry and base classes.
                                                             (line  140)
* getrecursionlimit() (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line  880)
* getrefcount() (nel modulo sys):        sys — System-specific parameters and functions.
                                                             (line  859)
* GetReparseDeferralEnabled() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  111)
* getresgid() (nel modulo os):           Process Parameters. (line  347)
* getresponse() (http.client.HTTPConnection metodo): HTTPConnection Objects.
                                                             (line   80)
* getresuid() (nel modulo os):           Process Parameters. (line  338)
* getrlimit() (nel modulo resource):     Resource Limits.    (line   24)
* getroot() (xml.etree.ElementTree.ElementTree metodo): ElementTree Objects.
                                                             (line   36)
* getrusage() (nel modulo resource):     Resource Usage.     (line    8)
* getsampwidth() (wave.Wave_read metodo): Wave_read Objects. (line   24)
* getscreen() (nel modulo turtle):       Special Turtle methods.
                                                             (line   63)
* getservbyname() (nel modulo socket):   Other functions<2>. (line  203)
* getservbyport() (nel modulo socket):   Other functions<2>. (line  214)
* GetSetDescriptorType (nel modulo types): Standard Interpreter Types.
                                                             (line  203)
* getshapes() (nel modulo turtle):       Settings and special methods.
                                                             (line   64)
* getsid() (nel modulo os):              Process Parameters. (line  534)
* getsignal() (nel modulo signal):       Module contents<2>. (line  312)
* getsitepackages() (nel modulo site):   Module contents<5>. (line   58)
* getsize() (nel modulo os.path):        os path — Common pathname manipulations.
                                                             (line  199)
* getsizeof() (nel modulo sys):          sys — System-specific parameters and functions.
                                                             (line  887)
* getsockname() (socket.socket metodo):  Socket Objects.     (line  144)
* getsockopt() (socket.socket metodo):   Socket Objects.     (line  150)
* getsource() (nel modulo inspect):      Retrieving source code.
                                                             (line   59)
* getsourcefile() (nel modulo inspect):  Retrieving source code.
                                                             (line   38)
* getsourcelines() (nel modulo inspect): Retrieving source code.
                                                             (line   45)
* getstate() (codecs.IncrementalDecoder metodo): IncrementalDecoder Objects.
                                                             (line   44)
* getstate() (codecs.IncrementalEncoder metodo): IncrementalEncoder Objects.
                                                             (line   42)
* getstate() (nel modulo random):        Bookkeeping functions.
                                                             (line   32)
* getstate() (random.Random metodo):     Alternative Generator.
                                                             (line   24)
* getstatusoutput() (nel modulo subprocess): Legacy Shell Invocation Functions.
                                                             (line   11)
* getstr() (curses.window metodo):       Window Objects.     (line  268)
* getSubject() (logging.handlers.SMTPHandler metodo): SMTPHandler.
                                                             (line   39)
* getswitchinterval() (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line  909)
* getSystemId() (xml.sax.xmlreader.InputSource metodo): InputSource Objects.
                                                             (line   18)
* getSystemId() (xml.sax.xmlreader.Locator metodo): Locator Objects.
                                                             (line   20)
* getsyx() (nel modulo curses):          Functions<5>.       (line  178)
* gettarinfo() (tarfile.TarFile metodo): TarFile Objects.    (line  304)
* gettempdir() (nel modulo tempfile):    tempfile — Generate temporary files and directories.
                                                             (line  322)
* gettempdirb() (nel modulo tempfile):   tempfile — Generate temporary files and directories.
                                                             (line  354)
* gettempprefix() (nel modulo tempfile): tempfile — Generate temporary files and directories.
                                                             (line  360)
* gettempprefixb() (nel modulo tempfile): tempfile — Generate temporary files and directories.
                                                             (line  365)
* getter (C type):                       Defining Getters and Setters.
                                                             (line   33)
* getTestCaseNames() (unittest.TestLoader metodo): Loading and running tests.
                                                             (line  111)
* gettext() (gettext.GNUTranslations metodo): The GNUTranslations class.
                                                             (line   38)
* gettext() (gettext.NullTranslations metodo): The NullTranslations class.
                                                             (line   35)
* gettext() (nel modulo gettext):        GNU gettext API.    (line   32)
* gettext() (nel modulo locale):         Access to message catalogs.
                                                             (line    6)
* gettimeout() (socket.socket metodo):   Socket Objects.     (line  174)
* gettrace() (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line  977)
* gettrace() (nel modulo threading):     Reference<2>.       (line  130)
* getturtle() (nel modulo turtle):       Special Turtle methods.
                                                             (line   52)
* getType() (xml.sax.xmlreader.Attributes metodo): The Attributes Interface.
                                                             (line   19)
* getuid() (nel modulo os):              Process Parameters. (line  356)
* getunicodeinternedsize() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line  772)
* geturl() (http.client.HTTPResponse metodo): HTTPResponse Objects.
                                                             (line   79)
* geturl() (urllib.parse.urllib.parse.SplitResult metodo): Structured Parse Results.
                                                             (line   12)
* geturl() (urllib.response.addinfourl metodo): urllib response — Response classes used by urllib.
                                                             (line   30)
* getuser() (nel modulo getpass):        getpass — Portable password input.
                                                             (line   55)
* getuserbase() (nel modulo site):       Module contents<5>. (line   64)
* getusersitepackages() (nel modulo site): Module contents<5>.
                                                             (line   72)
* getvalue() (io.BytesIO metodo):        Buffered Streams.   (line   39)
* getvalue() (io.StringIO metodo):       Text I/O<2>.        (line  269)
* getValue() (xml.sax.xmlreader.Attributes metodo): The Attributes Interface.
                                                             (line   24)
* getValueByQName() (xml.sax.xmlreader.AttributesNS metodo): The AttributesNS Interface.
                                                             (line   12)
* getwch() (nel modulo msvcrt):          Console I/O.        (line   21)
* getwche() (nel modulo msvcrt):         Console I/O.        (line   31)
* getweakrefcount() (nel modulo weakref): weakref — Weak references.
                                                             (line  156)
* getweakrefs() (nel modulo weakref):    weakref — Weak references.
                                                             (line  161)
* getwelcome() (ftplib.FTP metodo):      FTP objects.        (line  122)
* getwelcome() (poplib.POP3 metodo):     POP3 Objects.       (line   20)
* getwin() (nel modulo curses):          Functions<5>.       (line  184)
* getwindowsversion() (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line  988)
* getwriter() (nel modulo codecs):       codecs — Codec registry and base classes.
                                                             (line  148)
* getxattr() (nel modulo os):            Linux extended attributes.
                                                             (line   10)
* getyx() (curses.window metodo):        Window Objects.     (line  282)
* gid (tarfile.TarInfo attributo):       TarInfo Objects.    (line  113)
* GIL:                                   Glossary.           (line  769)
* gil (sys.flags attributo):             sys — System-specific parameters and functions.
                                                             (line  594)
* glob() (nel modulo glob):              glob — Unix style pathname pattern expansion.
                                                             (line   29)
* glob() (pathlib.Path metodo):          Reading directories.
                                                             (line   30)
* Global (classe in ast):                Function and class definitions.
                                                             (line  145)
* global interpreter lock:               Thread State and the Global Interpreter Lock.
                                                             (line    6)
* global interpreter lock <1>:           Glossary.           (line  773)
* global state:                          Glossary.           (line  801)
* global_enum() (nel modulo enum):       Utilities and Decorators.
                                                             (line   92)
* global;name;binding:                   The global statement.
                                                             (line    6)
* global;namespace:                      Special read-only attributes.
                                                             (line    6)
* globs (doctest.DocTest attributo):     DocTest Objects.    (line   22)
* gmtime() (nel modulo time):            Functions<4>.       (line  139)
* gname (tarfile.TarInfo attributo):     TarInfo Objects.    (line  129)
* GNOME:                                 The Catalog constructor.
                                                             (line    6)
* GNU_FORMAT (nel modulo tarfile):       tarfile — Read and write tar archive files.
                                                             (line  377)
* gnu_getopt() (nel modulo getopt):      getopt — C-style parser for command line options.
                                                             (line   75)
* GNUTranslations (classe in gettext):   The GNUTranslations class.
                                                             (line   33)
* GNUTYPE_LONGLINK (nel modulo tarfile): tarfile — Read and write tar archive files.
                                                             (line  361)
* GNUTYPE_LONGNAME (nel modulo tarfile): tarfile — Read and write tar archive files.
                                                             (line  357)
* GNUTYPE_SPARSE (nel modulo tarfile):   tarfile — Read and write tar archive files.
                                                             (line  365)
* go() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line  114)
* got (doctest.DocTestFailure attributo): Debugging.         (line  204)
* goto() (nel modulo turtle):            Turtle motion.      (line   74)
* grammar:                               Notation.           (line    6)
* grantpt() (nel modulo os):             File Descriptor Operations.
                                                             (line  249)
* Graphical User Interface:              Graphical user interfaces with Tk.
                                                             (line    6)
* GREATER (nel modulo token):            token — Constants used with Python parse trees.
                                                             (line  254)
* GREATEREQUAL (nel modulo token):       token — Constants used with Python parse trees.
                                                             (line  281)
* greedy (compression.zstd.Strategy attributo): Advanced parameter control.
                                                             (line  313)
* Greenwich Mean Time:                   time — Time access and conversions.
                                                             (line   39)
* GRND_NONBLOCK (nel modulo os):         Random numbers<2>.  (line   76)
* GRND_RANDOM (nel modulo os):           Random numbers<2>.  (line   89)
* Group (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  457)
* group() (pathlib.Path metodo):         Permissions and ownership.
                                                             (line   22)
* group() (re.Match metodo):             Match Objects.      (line   36)
* groupby() (nel modulo itertools):      Itertool Functions. (line  308)
* groupdict() (re.Match metodo):         Match Objects.      (line  136)
* groupindex (re.Pattern attributo):     Regular Expression Objects.
                                                             (line  118)
* grouping:                              Indentation.        (line    6)
* groups (email.headerregistry.AddressHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  188)
* groups (re.Pattern attributo):         Regular Expression Objects.
                                                             (line  114)
* groups() (re.Match metodo):            Match Objects.      (line  113)
* GS (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line  112)
* Gt (classe in ast):                    Expressions<2>.     (line  108)
* gt() (nel modulo operator):            operator — Standard operators as functions.
                                                             (line   24)
* GtE (classe in ast):                   Expressions<2>.     (line  108)
* guard:                                 Guards.             (line    6)
* guess_all_extensions() (mimetypes.MimeTypes metodo): MimeTypes objects.
                                                             (line   72)
* guess_all_extensions() (nel modulo mimetypes): mimetypes — Map filenames to MIME types.
                                                             (line   67)
* guess_extension() (mimetypes.MimeTypes metodo): MimeTypes objects.
                                                             (line   55)
* guess_extension() (nel modulo mimetypes): mimetypes — Map filenames to MIME types.
                                                             (line   79)
* guess_file_type() (mimetypes.MimeTypes metodo): MimeTypes objects.
                                                             (line   65)
* guess_file_type() (nel modulo mimetypes): mimetypes — Map filenames to MIME types.
                                                             (line   58)
* guess_scheme() (nel modulo wsgiref.util): wsgiref util – WSGI environment utilities.
                                                             (line   14)
* guess_type() (mimetypes.MimeTypes metodo): MimeTypes objects.
                                                             (line   60)
* guess_type() (nel modulo mimetypes):   mimetypes — Map filenames to MIME types.
                                                             (line   24)
* GUI:                                   Graphical user interfaces with Tk.
                                                             (line    6)
* gzip command line option; -best:       Command-line options.
                                                             (line   14)
* gzip command line option; -d:          Command-line options.
                                                             (line   18)
* gzip command line option; -decompress: Command-line options.
                                                             (line   18)
* gzip command line option; -fast:       Command-line options.
                                                             (line   10)
* gzip command line option; -h:          Command-line options.
                                                             (line   22)
* gzip command line option; -help:       Command-line options.
                                                             (line   22)
* gzip command line option; file:        Command-line options.
                                                             (line    6)
* GzipFile (classe in gzip):             gzip — Support for gzip files.
                                                             (line   76)
* halfdelay() (nel modulo curses):       Functions<5>.       (line  226)
* Handle (classe in asyncio):            Callback Handles.   (line    6)
* handle an exception:                   Exceptions.         (line    6)
* handle_charref() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line   92)
* handle_comment() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line  101)
* handle_data() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line   80)
* handle_decl() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line  114)
* handle_defect() (email.policy.Policy metodo): email policy Policy Objects.
                                                             (line  235)
* handle_endtag() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line   64)
* handle_entityref() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line   85)
* handle_error() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line  141)
* handle_expect_100() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  252)
* handle_one_request() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  246)
* handle_pi() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line  122)
* handle_request() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line   22)
* handle_request() (xmlrpc.server.CGIXMLRPCRequestHandler metodo): CGIXMLRPCRequestHandler.
                                                             (line   50)
* handle_startendtag() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line   71)
* handle_starttag() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line   45)
* handle_timeout() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line  151)
* handle() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  239)
* handle() (logging.Handler metodo):     Handler Objects.    (line   83)
* handle() (logging.handlers.QueueListener metodo): QueueListener.
                                                             (line   73)
* handle() (logging.Logger metodo):      Logger Objects.     (line  367)
* handle() (logging.NullHandler metodo): NullHandler.        (line   20)
* handle() (socketserver.BaseRequestHandler metodo): Request Handler Objects.
                                                             (line   20)
* handle() (wsgiref.simple_server.WSGIRequestHandler metodo): wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line  106)
* handleError() (logging.Handler metodo): Handler Objects.   (line   90)
* handleError() (logging.handlers.SocketHandler metodo): SocketHandler.
                                                             (line   33)
* Handler (classe in logging):           Handler Objects.    (line   11)
* Handlers (classe in signal):           Module contents<2>. (line   24)
* handlers (logging.Logger attributo):   Logger Objects.     (line   87)
* hardlink_to() (pathlib.Path metodo):   Creating files and directories.
                                                             (line   73)
* harmonic_mean() (nel modulo statistics): Function details. (line   97)
* HAS_ALPN (nel modulo ssl):             Constants<9>.       (line  382)
* has_children() (symtable.SymbolTable metodo): Examining Symbol Tables.
                                                             (line   98)
* has_colors() (nel modulo curses):      Functions<5>.       (line  191)
* has_default() (typing.ParamSpec metodo): Building generic types and type aliases.
                                                             (line  494)
* has_default() (typing.TypeVar metodo): Building generic types and type aliases.
                                                             (line  237)
* has_default() (typing.TypeVarTuple metodo): Building generic types and type aliases.
                                                             (line  381)
* has_dualstack_ipv6() (nel modulo socket): Creating sockets.
                                                             (line  153)
* HAS_ECDH (nel modulo ssl):             Constants<9>.       (line  398)
* has_extended_color_support() (nel modulo curses): Functions<5>.
                                                             (line  196)
* has_extn() (smtplib.SMTP metodo):      SMTP Objects.       (line   85)
* has_header() (csv.Sniffer metodo):     Module Contents<3>. (line  242)
* has_header() (urllib.request.Request metodo): Request Objects.
                                                             (line   95)
* has_ic() (nel modulo curses):          Functions<5>.       (line  207)
* has_il() (nel modulo curses):          Functions<5>.       (line  214)
* has_ipv6 (nel modulo socket):          Constants<8>.       (line  302)
* has_key() (nel modulo curses):         Functions<5>.       (line  221)
* has_location (importlib.machinery.ModuleSpec attributo): importlib machinery – Importers and path hooks.
                                                             (line  437)
* HAS_NEVER_CHECK_COMMON_NAME (nel modulo ssl): Constants<9>.
                                                             (line  390)
* has_nonstandard_attr() (http.cookiejar.Cookie metodo): Cookie Objects<2>.
                                                             (line   98)
* HAS_NPN (nel modulo ssl):              Constants<9>.       (line  413)
* has_option() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  142)
* has_option() (optparse.OptionParser metodo): Querying and manipulating your option parser.
                                                             (line   42)
* HAS_PHA (nel modulo ssl):              Constants<9>.       (line  471)
* HAS_PSK (nel modulo ssl):              Constants<9>.       (line  465)
* has_section() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  133)
* HAS_SNI (nel modulo ssl):              Constants<9>.       (line  406)
* HAS_SSLv2 (nel modulo ssl):            Constants<9>.       (line  423)
* HAS_SSLv3 (nel modulo ssl):            Constants<9>.       (line  430)
* has_ticket (ssl.SSLSession attributo): SSL session.        (line   20)
* HAS_TLSv1 (nel modulo ssl):            Constants<9>.       (line  437)
* HAS_TLSv1_1 (nel modulo ssl):          Constants<9>.       (line  444)
* HAS_TLSv1_2 (nel modulo ssl):          Constants<9>.       (line  451)
* HAS_TLSv1_3 (nel modulo ssl):          Constants<9>.       (line  458)
* hasarg (nel modulo dis):               Opcode collections. (line   25)
* hasAttribute() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   22)
* hasAttributeNS() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   26)
* hasAttributes() (xml.dom.Node metodo): Node Objects.       (line   94)
* hasChildNodes() (xml.dom.Node metodo): Node Objects.       (line   98)
* hascompare (nel modulo dis):           Opcode collections. (line   58)
* hasconst (nel modulo dis):             Opcode collections. (line   31)
* hasexc (nel modulo dis):               Opcode collections. (line   62)
* hasFeature() (xml.dom.DOMImplementation metodo): DOMImplementation Objects.
                                                             (line   11)
* hasfree (nel modulo dis):              Opcode collections. (line   35)
* hash character:                        Comments.           (line    6)
* hash_bits (sys.hash_info attributo):   sys — System-specific parameters and functions.
                                                             (line 1096)
* hash_info (nel modulo sys):            sys — System-specific parameters and functions.
                                                             (line 1065)
* hash_log (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line   63)
* hash_randomization (sys.flags attributo): sys — System-specific parameters and functions.
                                                             (line  574)
* hash-based pyc:                        Glossary.           (line  809)
* hash.block_size (nel modulo hashlib):  Hash Objects.       (line   13)
* hash.digest_size (nel modulo hashlib): Hash Objects.       (line    9)
* hashable:                              Dictionary displays.
                                                             (line   37)
* hashable <1>:                          Glossary.           (line  815)
* Hashable (classe in collections.abc):  Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   11)
* Hashable (classe in typing):           Aliases to other ABCs in collections abc.
                                                             (line   54)
* hasHandlers() (logging.Logger metodo): Logger Objects.     (line  382)
* hashfunc (C type):                     Slot Type typedefs. (line   77)
* hasjabs (nel modulo dis):              Opcode collections. (line   75)
* hasjrel (nel modulo dis):              Opcode collections. (line   68)
* hasjump (nel modulo dis):              Opcode collections. (line   47)
* haslocal (nel modulo dis):             Opcode collections. (line   54)
* hasname (nel modulo dis):              Opcode collections. (line   43)
* HAVE_ARGUMENT (opcode):                Python Bytecode Instructions.
                                                             (line 1321)
* HAVE_CONTEXTVAR (nel modulo decimal):  Constants<4>.       (line   35)
* HAVE_DOCSTRINGS (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  180)
* HAVE_THREADS (nel modulo decimal):     Constants<4>.       (line   28)
* HCI_CHANNEL_CONTROL (nel modulo socket): Constants<8>.     (line  393)
* HCI_CHANNEL_LOGGING (nel modulo socket): Constants<8>.     (line  393)
* HCI_CHANNEL_MONITOR (nel modulo socket): Constants<8>.     (line  393)
* HCI_CHANNEL_RAW (nel modulo socket):   Constants<8>.       (line  393)
* HCI_CHANNEL_USER (nel modulo socket):  Constants<8>.       (line  393)
* HCI_DATA_DIR (nel modulo socket):      Constants<8>.       (line  371)
* HCI_DEV_NONE (nel modulo socket):      Constants<8>.       (line  384)
* HCI_FILTER (nel modulo socket):        Constants<8>.       (line  371)
* HCI_TIME_STAMP (nel modulo socket):    Constants<8>.       (line  371)
* Header (classe in email.header):       email header Internationalized headers.
                                                             (line   60)
* header_encode_lines() (email.charset.Charset metodo): email charset Representing character sets.
                                                             (line  125)
* header_encode() (email.charset.Charset metodo): email charset Representing character sets.
                                                             (line  118)
* header_encoding (email.charset.Charset attributo): email charset Representing character sets.
                                                             (line   59)
* header_factory (email.policy.EmailPolicy attributo): email policy Policy Objects.
                                                             (line  408)
* header_fetch_parse() (email.policy.Compat32 metodo): email policy Policy Objects.
                                                             (line  594)
* header_fetch_parse() (email.policy.EmailPolicy metodo): email policy Policy Objects.
                                                             (line  458)
* header_fetch_parse() (email.policy.Policy metodo): email policy Policy Objects.
                                                             (line  319)
* header_items() (urllib.request.Request metodo): Request Objects.
                                                             (line  126)
* header_max_count() (email.policy.EmailPolicy metodo): email policy Policy Objects.
                                                             (line  435)
* header_max_count() (email.policy.Policy metodo): email policy Policy Objects.
                                                             (line  260)
* header_offset (zipfile.ZipInfo attributo): ZipInfo objects.
                                                             (line  146)
* header_source_parse() (email.policy.Compat32 metodo): email policy Policy Objects.
                                                             (line  582)
* header_source_parse() (email.policy.EmailPolicy metodo): email policy Policy Objects.
                                                             (line  441)
* header_source_parse() (email.policy.Policy metodo): email policy Policy Objects.
                                                             (line  282)
* header_store_parse() (email.policy.Compat32 metodo): email policy Policy Objects.
                                                             (line  590)
* header_store_parse() (email.policy.EmailPolicy metodo): email policy Policy Objects.
                                                             (line  449)
* header_store_parse() (email.policy.Policy metodo): email policy Policy Objects.
                                                             (line  303)
* HeaderDefect:                          email errors Exception and Defect classes.
                                                             (line   60)
* HeaderError:                           tarfile — Read and write tar archive files.
                                                             (line  271)
* HeaderParseError:                      email errors Exception and Defect classes.
                                                             (line   26)
* HeaderParser (classe in email.parser): Parser API.         (line  108)
* HeaderRegistry (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  299)
* Headers (classe in wsgiref.headers):   wsgiref headers – WSGI response header tools.
                                                             (line    9)
* headers (http.client.HTTPResponse attributo): HTTPResponse Objects.
                                                             (line   56)
* headers (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  156)
* headers (urllib.error.HTTPError attributo): urllib error — Exception classes raised by urllib request.
                                                             (line   55)
* headers (urllib.response.addinfourl attributo): urllib response — Response classes used by urllib.
                                                             (line   19)
* headers (xmlrpc.client.ProtocolError attributo): ProtocolError Objects.
                                                             (line   25)
* HeaderWriteError:                      email errors Exception and Defect classes.
                                                             (line   50)
* heading() (nel modulo turtle):         Tell Turtle’s state.
                                                             (line   58)
* heading() (tkinter.ttk.Treeview metodo): ttk Treeview.     (line   99)
* heapify_max() (nel modulo heapq):      heapq — Heap queue algorithm.
                                                             (line   97)
* heapify() (nel modulo heapq):          heapq — Heap queue algorithm.
                                                             (line   55)
* heapmin() (nel modulo msvcrt):         Other Functions.    (line    6)
* heappop_max() (nel modulo heapq):      heapq — Heap queue algorithm.
                                                             (line  110)
* heappop() (nel modulo heapq):          heapq — Heap queue algorithm.
                                                             (line   64)
* heappush_max() (nel modulo heapq):     heapq — Heap queue algorithm.
                                                             (line  103)
* heappush() (nel modulo heapq):         heapq — Heap queue algorithm.
                                                             (line   59)
* heappushpop_max() (nel modulo heapq):  heapq — Heap queue algorithm.
                                                             (line  119)
* heappushpop() (nel modulo heapq):      heapq — Heap queue algorithm.
                                                             (line   71)
* heapreplace_max() (nel modulo heapq):  heapq — Heap queue algorithm.
                                                             (line  128)
* heapreplace() (nel modulo heapq):      heapq — Heap queue algorithm.
                                                             (line   78)
* helo_resp (smtplib.SMTP attributo):    SMTP Objects.       (line  353)
* helo() (smtplib.SMTP metodo):          SMTP Objects.       (line   47)
* help (optparse.Option attributo):      Option attributes.  (line   80)
* help (pdb command):                    Debugger commands.  (line   77)
* help;online:                           pydoc — Documentation generator and online help system.
                                                             (line    8)
* herror:                                Exceptions<17>.     (line   13)
* hex (uuid.UUID attributo):             uuid — UUID objects according to RFC 9562.
                                                             (line  142)
* hex() (bytearray metodo):              Oggetti Bytearray.  (line   59)
* hex() (bytes metodo):                  Oggetti bytes.      (line   90)
* hex() (float metodo):                  Metodi aggiuntivi su Float.
                                                             (line   51)
* hex() (memoryview metodo):             Memory Views.       (line  201)
* hexadecimal literal:                   Numeric literals.   (line    6)
* hexdigest() (hashlib.hash metodo):     Hash Objects.       (line   44)
* hexdigest() (hashlib.shake metodo):    SHAKE variable length digests.
                                                             (line   21)
* hexdigest() (hmac.HMAC metodo):        hmac — Keyed-Hashing for Message Authentication.
                                                             (line   73)
* hexdigits (nel modulo string):         String constants.   (line   28)
* hexlify() (nel modulo binascii):       binascii — Convert between binary and ASCII.
                                                             (line  114)
* hexversion (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line 1114)
* hidden() (curses.panel.Panel metodo):  Panel Objects.      (line   25)
* hide_cookie2 (http.cookiejar.CookiePolicy attributo): CookiePolicy Objects.
                                                             (line   76)
* hide() (curses.panel.Panel metodo):    Panel Objects.      (line   30)
* hide() (tkinter.ttk.Notebook metodo):  ttk Notebook.       (line   23)
* hideturtle() (nel modulo turtle):      Visibility.         (line    6)
* HierarchyRequestErr:                   Exceptions<22>.     (line   29)
* HIGH_PRIORITY_CLASS (nel modulo subprocess): Windows Constants.
                                                             (line   82)
* HIGHEST_PROTOCOL (nel modulo pickle):  Module Interface.   (line   14)
* hits (bdb.Breakpoint attributo):       bdb — Debugger framework.
                                                             (line  124)
* HKEY_CLASSES_ROOT (nel modulo winreg): HKEY_* Constants.   (line    6)
* HKEY_CURRENT_CONFIG (nel modulo winreg): HKEY_* Constants. (line   38)
* HKEY_CURRENT_USER (nel modulo winreg): HKEY_* Constants.   (line   12)
* HKEY_DYN_DATA (nel modulo winreg):     HKEY_* Constants.   (line   43)
* HKEY_LOCAL_MACHINE (nel modulo winreg): HKEY_* Constants.  (line   19)
* HKEY_PERFORMANCE_DATA (nel modulo winreg): HKEY_* Constants.
                                                             (line   31)
* HKEY_USERS (nel modulo winreg):        HKEY_* Constants.   (line   25)
* hline() (curses.window metodo):        Window Objects.     (line  287)
* hls_to_rgb() (nel modulo colorsys):    colorsys — Conversions between color systems.
                                                             (line   40)
* HMAC (classe in hmac):                 hmac — Keyed-Hashing for Message Authentication.
                                                             (line   47)
* HOME:                                  os path<5>.         (line   15)
* HOME <1>:                              Changes in the Python API<5>.
                                                             (line  118)
* HOME <2>:                              Windows<47>.        (line   15)
* HOME <3>:                              Windows<47>.        (line   18)
* HOME <4>:                              os path — Common pathname manipulations.
                                                             (line  141)
* HOME <5>:                              os path — Common pathname manipulations.
                                                             (line  158)
* HOME <6>:                              Tkinter Modules.    (line   66)
* home() (nel modulo turtle):            Turtle motion.      (line  195)
* home() (pathlib.Path metodo della classe): Expanding and resolving paths.
                                                             (line    6)
* HOMEDRIVE:                             os path — Common pathname manipulations.
                                                             (line  148)
* HOMEPATH:                              os path — Common pathname manipulations.
                                                             (line  148)
* hook_compressed() (nel modulo fileinput): fileinput — Iterate over lines from multiple input streams.
                                                             (line  196)
* hook_encoded() (nel modulo fileinput): fileinput — Iterate over lines from multiple input streams.
                                                             (line  216)
* hooks;import:                          Import hooks.       (line    6)
* hooks;meta:                            Import hooks.       (line    6)
* hooks;path:                            Import hooks.       (line    6)
* host (urllib.request.Request attributo): Request Objects.  (line   25)
* hostmask (ipaddress.IPv4Network attributo): Network objects.
                                                             (line   97)
* hostmask (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  314)
* hostname_checks_common_name (ssl.SSLContext attributo): SSL Contexts.
                                                             (line  614)
* hosts (netrc.netrc attributo):         netrc Objects.      (line   23)
* hosts() (ipaddress.IPv4Network metodo): Network objects.   (line  136)
* hosts() (ipaddress.IPv6Network metodo): Network objects.   (line  332)
* hour (datetime.datetime attributo):    datetime Objects.   (line  318)
* hour (datetime.time attributo):        time Objects.       (line   50)
* HRESULT (classe in ctypes):            Fundamental data types<2>.
                                                             (line  234)
* hresult (ctypes.COMError attributo):   Exceptions<9>.      (line   15)
* hStdError (subprocess.STARTUPINFO attributo): Windows Popen Helpers.
                                                             (line   43)
* hStdInput (subprocess.STARTUPINFO attributo): Windows Popen Helpers.
                                                             (line   28)
* hStdOutput (subprocess.STARTUPINFO attributo): Windows Popen Helpers.
                                                             (line   36)
* hsv_to_rgb() (nel modulo colorsys):    colorsys — Conversions between color systems.
                                                             (line   48)
* HT (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line   49)
* ht() (nel modulo turtle):              Visibility.         (line    6)
* HTML:                                  html parser — Simple HTML and XHTML parser.
                                                             (line    8)
* HTML <1>:                              urllib request Restrictions.
                                                             (line   29)
* html5 (nel modulo html.entities):      html entities — Definitions of HTML general entities.
                                                             (line   14)
* HTMLCalendar (classe in calendar):     calendar — General calendar-related functions.
                                                             (line  223)
* HtmlDiff (classe in difflib):          difflib — Helpers for computing deltas.
                                                             (line   82)
* HTMLParser (classe in html.parser):    html parser — Simple HTML and XHTML parser.
                                                             (line   14)
* htonl() (nel modulo socket):           Other functions<2>. (line  242)
* htons() (nel modulo socket):           Other functions<2>. (line  249)
* HTTP (nel modulo email.policy):        email policy Policy Objects.
                                                             (line  525)
* http_error_301() (urllib.request.HTTPRedirectHandler metodo): HTTPRedirectHandler Objects.
                                                             (line   35)
* http_error_302() (urllib.request.HTTPRedirectHandler metodo): HTTPRedirectHandler Objects.
                                                             (line   42)
* http_error_303() (urllib.request.HTTPRedirectHandler metodo): HTTPRedirectHandler Objects.
                                                             (line   48)
* http_error_307() (urllib.request.HTTPRedirectHandler metodo): HTTPRedirectHandler Objects.
                                                             (line   54)
* http_error_308() (urllib.request.HTTPRedirectHandler metodo): HTTPRedirectHandler Objects.
                                                             (line   61)
* http_error_401() (urllib.request.HTTPBasicAuthHandler metodo): HTTPBasicAuthHandler Objects.
                                                             (line    6)
* http_error_401() (urllib.request.HTTPDigestAuthHandler metodo): HTTPDigestAuthHandler Objects.
                                                             (line    6)
* http_error_407() (urllib.request.ProxyBasicAuthHandler metodo): ProxyBasicAuthHandler Objects.
                                                             (line    6)
* http_error_407() (urllib.request.ProxyDigestAuthHandler metodo): ProxyDigestAuthHandler Objects.
                                                             (line    6)
* http_error_auth_reqed() (urllib.request.AbstractBasicAuthHandler metodo): AbstractBasicAuthHandler Objects.
                                                             (line    6)
* http_error_auth_reqed() (urllib.request.AbstractDigestAuthHandler metodo): AbstractDigestAuthHandler Objects.
                                                             (line    6)
* http_error_default() (urllib.request.BaseHandler metodo): BaseHandler Objects.
                                                             (line   66)
* http_open() (urllib.request.HTTPHandler metodo): HTTPHandler Objects.
                                                             (line    6)
* HTTP_PORT (nel modulo http.client):    http client — HTTP protocol client.
                                                             (line  201)
* http_response() (urllib.request.HTTPErrorProcessor metodo): HTTPErrorProcessor Objects.
                                                             (line    6)
* http_version (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  307)
* HTTP;http (standard module):           http — HTTP modules.
                                                             (line    8)
* HTTP;http.client (standard module):    http client — HTTP protocol client.
                                                             (line    8)
* HTTP;protocol:                         urllib request Restrictions.
                                                             (line    6)
* HTTP;protocol <1>:                     urllib request Restrictions.
                                                             (line   29)
* HTTP;protocol <2>:                     http — HTTP modules.
                                                             (line    8)
* HTTP;protocol <3>:                     http client — HTTP protocol client.
                                                             (line    8)
* HTTP;protocol <4>:                     http server — HTTP servers.
                                                             (line    8)
* http.server command line option; -b:   Command-line interface<7>.
                                                             (line   21)
* http.server command line option; -bind: Command-line interface<7>.
                                                             (line   21)
* http.server command line option; -cgi: Command-line interface<7>.
                                                             (line   54)
* http.server command line option; -d:   Command-line interface<7>.
                                                             (line   34)
* http.server command line option; -directory: Command-line interface<7>.
                                                             (line   34)
* http.server command line option; -p:   Command-line interface<7>.
                                                             (line   44)
* http.server command line option; -protocol: Command-line interface<7>.
                                                             (line   44)
* http.server command line option; -tls-cert: Command-line interface<7>.
                                                             (line   70)
* http.server command line option; -tls-key: Command-line interface<7>.
                                                             (line   78)
* http.server command line option; -tls-password-file: Command-line interface<7>.
                                                             (line   86)
* http.server command line option; port: Command-line interface<7>.
                                                             (line   14)
* http.server;security:                  Security considerations<3>.
                                                             (line    6)
* HTTPBasicAuthHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  406)
* HTTPConnection (classe in http.client): http client — HTTP protocol client.
                                                             (line   31)
* HTTPCookieProcessor (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  337)
* httpd:                                 http server — HTTP servers.
                                                             (line    8)
* HTTPDefaultErrorHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  328)
* HTTPDigestAuthHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  433)
* HTTPError:                             urllib error — Exception classes raised by urllib request.
                                                             (line   31)
* HTTPErrorProcessor (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  494)
* HTTPException:                         http client — HTTP protocol client.
                                                             (line  132)
* HTTPHandler (classe in logging.handlers): HTTPHandler.     (line   10)
* HTTPHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  457)
* HTTPMessage (classe in http.client):   HTTPMessage Objects.
                                                             (line    6)
* HTTPMethod (classe in http):           HTTP status category.
                                                             (line   38)
* httponly (http.cookies.Morsel attributo): Morsel Objects.  (line   13)
* HTTPPasswordMgr (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  363)
* HTTPPasswordMgrWithDefaultRealm (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  367)
* HTTPPasswordMgrWithPriorAuth (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  373)
* HTTPRedirectHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  333)
* HTTPResponse (classe in http.client):  http client — HTTP protocol client.
                                                             (line  100)
* https_open() (urllib.request.HTTPSHandler metodo): HTTPSHandler Objects.
                                                             (line    6)
* HTTPS_PORT (nel modulo http.client):   http client — HTTP protocol client.
                                                             (line  205)
* https_response() (urllib.request.HTTPErrorProcessor metodo): HTTPErrorProcessor Objects.
                                                             (line   18)
* HTTPSConnection (classe in http.client): http client — HTTP protocol client.
                                                             (line   62)
* HTTPServer (classe in http.server):    http server — HTTP servers.
                                                             (line   30)
* HTTPSHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  461)
* HTTPSServer (classe in http.server):   http server — HTTP servers.
                                                             (line   47)
* HTTPStatus (classe in http):           http — HTTP modules.
                                                             (line   27)
* HV_GUID_BROADCAST (nel modulo socket): Constants<8>.       (line  445)
* HV_GUID_CHILDREN (nel modulo socket):  Constants<8>.       (line  445)
* HV_GUID_LOOPBACK (nel modulo socket):  Constants<8>.       (line  445)
* HV_GUID_PARENT (nel modulo socket):    Constants<8>.       (line  445)
* HV_GUID_WILDCARD (nel modulo socket):  Constants<8>.       (line  445)
* HV_GUID_ZERO (nel modulo socket):      Constants<8>.       (line  445)
* HV_PROTOCOL_RAW (nel modulo socket):   Constants<8>.       (line  445)
* HVSOCKET_ADDRESS_FLAG_PASSTHRU (nel modulo socket): Constants<8>.
                                                             (line  445)
* HVSOCKET_CONNECT_TIMEOUT (nel modulo socket): Constants<8>.
                                                             (line  445)
* HVSOCKET_CONNECT_TIMEOUT_MAX (nel modulo socket): Constants<8>.
                                                             (line  445)
* HVSOCKET_CONNECTED_SUSPEND (nel modulo socket): Constants<8>.
                                                             (line  445)
* hypot() (nel modulo math):             Summation and product functions.
                                                             (line   33)
* I (nel modulo re):                     Flags.              (line   38)
* I/O con buffer di linea:               Funzioni Incorporate.
                                                             (line 1539)
* I/O control;buffering:                 Socket Objects.     (line  213)
* I/O non bufferizzato:                  Funzioni Incorporate.
                                                             (line 1539)
* iadd() (nel modulo operator):          In-place Operators. (line   36)
* iand() (nel modulo operator):          In-place Operators. (line   41)
* iconcat() (nel modulo operator):       In-place Operators. (line   46)
* id (concurrent.interpreters.Interpreter attributo): Interpreter objects.
                                                             (line   14)
* id (concurrent.interpreters.Queue attributo): Communicating Between Interpreters.
                                                             (line   16)
* id (ssl.SSLSession attributo):         SSL session.        (line   12)
* id() (unittest.TestCase metodo):       Test cases.         (line  816)
* idcok() (curses.window metodo):        Window Objects.     (line  294)
* ident (select.kevent attributo):       Kevent Objects.     (line    8)
* ident (threading.Thread attributo):    Thread objects.     (line  205)
* identchars (cmd.Cmd attributo):        Cmd Objects.        (line  135)
* identifier:                            Names identifiers and keywords.
                                                             (line    6)
* identifier <1>:                        Identifiers Names.  (line    6)
* identify_column() (tkinter.ttk.Treeview metodo): ttk Treeview.
                                                             (line  143)
* identify_element() (tkinter.ttk.Treeview metodo): ttk Treeview.
                                                             (line  172)
* identify_region() (tkinter.ttk.Treeview metodo): ttk Treeview.
                                                             (line  150)
* identify_row() (tkinter.ttk.Treeview metodo): ttk Treeview.
                                                             (line  139)
* identify() (tkinter.ttk.Notebook metodo): ttk Notebook.    (line   32)
* identify() (tkinter.ttk.Treeview metodo): ttk Treeview.    (line  133)
* identify() (tkinter.ttk.Widget metodo): ttk Widget.        (line   11)
* identity of an object:                 Objects values and types.
                                                             (line   10)
* identity;test:                         Membership test operations.
                                                             (line   39)
* IDLE:                                  IDLE — Python editor and shell<2>.
                                                             (line    8)
* IDLE <1>:                              Glossary.           (line  835)
* idle command line option; -:           Command-line usage<5>.
                                                             (line   49)
* idle command line option; -c:          Command-line usage<5>.
                                                             (line   13)
* idle command line option; -d:          Command-line usage<5>.
                                                             (line   19)
* idle command line option; -e:          Command-line usage<5>.
                                                             (line   23)
* idle command line option; -h:          Command-line usage<5>.
                                                             (line   27)
* idle command line option; -i:          Command-line usage<5>.
                                                             (line   31)
* idle command line option; -r:          Command-line usage<5>.
                                                             (line   35)
* idle command line option; -s:          Command-line usage<5>.
                                                             (line   39)
* idle command line option; -t:          Command-line usage<5>.
                                                             (line   45)
* IDLE_PRIORITY_CLASS (nel modulo subprocess): Windows Constants.
                                                             (line   89)
* idle() (imaplib.IMAP4 metodo):         IMAP4 Objects.      (line  126)
* IDLESTARTUP:                           IDLE<37>.           (line  176)
* IDLESTARTUP <1>:                       IDLE<41>.           (line    9)
* IDLESTARTUP <2>:                       IDLE<47>.           (line    9)
* IDLESTARTUP <3>:                       Startup and Code Execution.
                                                             (line    7)
* IDLESTARTUP <4>:                       Command-line usage<5>.
                                                             (line   41)
* idlok() (curses.window metodo):        Window Objects.     (line  302)
* IEEE_CONTEXT_MAX_BITS (nel modulo decimal): Constants<4>.  (line   25)
* IEEEContext() (nel modulo decimal):    Context objects.    (line   62)
* If (classe in ast):                    Control flow.       (line    9)
* if_indextoname() (nel modulo socket):  Other functions<2>. (line  444)
* if_nameindex() (nel modulo socket):    Other functions<2>. (line  401)
* if_nametoindex() (nel modulo socket):  Other functions<2>. (line  426)
* if;conditional expression:             Conditional expressions.
                                                             (line    6)
* if;in comprehensions:                  Displays for lists sets and dictionaries.
                                                             (line   14)
* IfExp (classe in ast):                 Expressions<2>.     (line  157)
* ifloordiv() (nel modulo operator):     In-place Operators. (line   52)
* iglob() (nel modulo glob):             glob — Unix style pathname pattern expansion.
                                                             (line   80)
* ignorableWhitespace() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line  148)
* ignore (bdb.Breakpoint attributo):     bdb — Debugger framework.
                                                             (line  120)
* IGNORE (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  151)
* ignore (pdb command):                  Debugger commands.  (line  153)
* ignore_environment (sys.flags attributo): sys — System-specific parameters and functions.
                                                             (line  562)
* ignore_errors() (nel modulo codecs):   Error Handlers.     (line  147)
* IGNORE_EXCEPTION_DETAIL (nel modulo doctest): Option Flags.
                                                             (line   56)
* ignore_patterns() (nel modulo shutil): Directory and files operations.
                                                             (line  204)
* ignore_warnings() (nel modulo test.support.warnings_helper): test support warnings_helper — Utilities for warnings tests.
                                                             (line   11)
* ignore;error handler's name:           Error Handlers.     (line   15)
* IGNORECASE (nel modulo re):            Flags.              (line   38)
* IISCGIHandler (classe in wsgiref.handlers): wsgiref handlers – server/gateway base classes.
                                                             (line   24)
* IllegalMonthError:                     calendar — General calendar-related functions.
                                                             (line  518)
* IllegalWeekdayError:                   calendar — General calendar-related functions.
                                                             (line  527)
* ilshift() (nel modulo operator):       In-place Operators. (line   57)
* imag (numbers.Complex attributo):      The numeric tower.  (line   19)
* imag (sys.hash_info attributo):        sys — System-specific parameters and functions.
                                                             (line 1087)
* imaginary literal:                     Numeric literals.   (line    6)
* imap_unordered() (multiprocessing.pool.Pool metodo): Process Pools.
                                                             (line  149)
* imap() (multiprocessing.pool.Pool metodo): Process Pools.  (line  134)
* IMAP4 (classe in imaplib):             imaplib — IMAP4 protocol client.
                                                             (line   25)
* IMAP4_SSL (classe in imaplib):         imaplib — IMAP4 protocol client.
                                                             (line   75)
* IMAP4_SSL;protocol:                    imaplib — IMAP4 protocol client.
                                                             (line    8)
* IMAP4_stream (classe in imaplib):      imaplib — IMAP4 protocol client.
                                                             (line  106)
* IMAP4_stream;protocol:                 imaplib — IMAP4 protocol client.
                                                             (line    8)
* IMAP4;protocol:                        imaplib — IMAP4 protocol client.
                                                             (line    8)
* IMAP4.abort:                           imaplib — IMAP4 protocol client.
                                                             (line   59)
* IMAP4.error:                           imaplib — IMAP4 protocol client.
                                                             (line   54)
* IMAP4.readonly:                        imaplib — IMAP4 protocol client.
                                                             (line   66)
* imatmul() (nel modulo operator):       In-place Operators. (line   72)
* immedok() (curses.window metodo):      Window Objects.     (line  308)
* immortal:                              Glossary.           (line  842)
* immutabile;sequenza;tipi:              Tipi di Sequenza Immutabili.
                                                             (line    6)
* immutable:                             Glossary.           (line  855)
* immutable object:                      Objects values and types.
                                                             (line   10)
* immutable;data;type:                   Literals<2>.        (line   17)
* immutable;object:                      Literals<2>.        (line   17)
* immutable;object <1>:                  Dictionary displays.
                                                             (line   37)
* imod() (nel modulo operator):          In-place Operators. (line   62)
* impl_detail() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  554)
* implementation (nel modulo sys):       sys — System-specific parameters and functions.
                                                             (line 1137)
* Import (classe in ast):                Imports.            (line    6)
* import hooks:                          Import hooks.       (line    6)
* import machinery:                      The import system.  (line    6)
* import path:                           Glossary.           (line  866)
* import_curses (C macro):               Curses C API.       (line   15)
* import_fresh_module() (nel modulo test.support.import_helper): test support import_helper — Utilities for import tests.
                                                             (line   16)
* IMPORT_FROM (opcode):                  Python Bytecode Instructions.
                                                             (line  850)
* import_module() (nel modulo importlib): Functions<12>.     (line   15)
* import_module() (nel modulo test.support.import_helper): test support import_helper — Utilities for import tests.
                                                             (line   52)
* IMPORT_NAME (opcode):                  Python Bytecode Instructions.
                                                             (line  841)
* importer:                              Glossary.           (line  879)
* ImportError:                           Concrete exceptions.
                                                             (line   52)
* ImportFrom (classe in ast):            Imports.            (line   20)
* importing:                             Glossary.           (line  874)
* ImportWarning:                         Warnings.           (line   61)
* ImproperConnectionState:               http client — HTTP protocol client.
                                                             (line  162)
* imul() (nel modulo operator):          In-place Operators. (line   67)
* In (classe in ast):                    Expressions<2>.     (line  108)
* in_dll() (ctypes._CData metodo):       Data types.         (line   63)
* in_table_a1() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   40)
* in_table_b1() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   45)
* in_table_c11_c12() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   69)
* in_table_c11() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   60)
* in_table_c12() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   64)
* in_table_c21_c22() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   84)
* in_table_c21() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   74)
* in_table_c22() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   79)
* in_table_c3() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   89)
* in_table_c4() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   93)
* in_table_c5() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   98)
* in_table_c6() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line  102)
* in_table_c7() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line  107)
* in_table_c8() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line  112)
* in_table_c9() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line  117)
* in_table_d1() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line  121)
* in_table_d2() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line  126)
* in_transaction (sqlite3.Connection attributo): Connection objects.
                                                             (line  767)
* inch() (curses.window metodo):         Window Objects.     (line  316)
* include() (nel modulo xml.etree.ElementInclude): Functions<9>.
                                                             (line   17)
* inclusive (tracemalloc.DomainFilter attributo): DomainFilter.
                                                             (line   12)
* inclusive (tracemalloc.Filter attributo): Filter.          (line   40)
* inclusive;or:                          Binary bitwise operations.
                                                             (line   20)
* Incomplete:                            binascii — Convert between binary and ASCII.
                                                             (line  161)
* IncompleteRead:                        http client — HTTP protocol client.
                                                             (line  158)
* IncompleteReadError:                   Exceptions<15>.     (line   44)
* incorporato;tipi:                      Tipi incorporati.   (line    9)
* incr_item():                           Exceptions<23>.     (line   78)
* incr_item() <1>:                       Exceptions<23>.     (line  123)
* increment_lineno() (nel modulo ast):   ast helpers.        (line  155)
* IncrementalDecoder (classe in codecs): IncrementalDecoder Objects.
                                                             (line   11)
* incrementaldecoder (codecs.CodecInfo attributo): codecs — Codec registry and base classes.
                                                             (line   87)
* IncrementalEncoder (classe in codecs): IncrementalEncoder Objects.
                                                             (line   11)
* incrementalencoder (codecs.CodecInfo attributo): codecs — Codec registry and base classes.
                                                             (line   87)
* IncrementalNewlineDecoder (classe in io): Text I/O<2>.     (line  291)
* IncrementalParser (classe in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers.
                                                             (line   20)
* indent (doctest.Example attributo):    Example Objects.    (line   47)
* INDENT (nel modulo token):             token — Constants used with Python parse trees.
                                                             (line   86)
* indent (reprlib.Repr attributo):       Repr Objects.       (line   54)
* INDENT token:                          Indentation.        (line   33)
* indent() (nel modulo textwrap):        textwrap — Text wrapping and filling.
                                                             (line  108)
* indent() (nel modulo xml.etree.ElementTree): Functions<8>. (line  118)
* indentation:                           Indentation.        (line    6)
* IndentationError:                      Concrete exceptions.
                                                             (line  364)
* index (inspect.FrameInfo attributo):   The interpreter stack.
                                                             (line   37)
* index (inspect.Traceback attributo):   The interpreter stack.
                                                             (line   78)
* index operation:                       Sequences.          (line    6)
* index() (array.array metodo):          array — Efficient arrays of numeric values.
                                                             (line  198)
* index() (bytearray metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  161)
* index() (bytes metodo):                Operazioni su Bytes e Bytearray.
                                                             (line  161)
* index() (collections.abc.ByteString metodo): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   83)
* index() (collections.deque metodo):    deque objects.      (line   70)
* index() (memoryview metodo):           Memory Views.       (line  398)
* index() (multiprocessing.shared_memory.ShareableList metodo): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  336)
* index() (nel modulo operator):         operator — Standard operators as functions.
                                                             (line  105)
* index() (sequence metodo):             Operazioni Comuni sulle Sequenze.
                                                             (line  183)
* index() (str metodo):                  Metodi per le Stringhe.
                                                             (line  242)
* index() (tkinter.ttk.Notebook metodo): ttk Notebook.       (line   37)
* index() (tkinter.ttk.Treeview metodo): ttk Treeview.       (line  178)
* IndexError:                            Concrete exceptions.
                                                             (line   80)
* indexOf() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  213)
* IndexSizeErr:                          Exceptions<22>.     (line   34)
* indices() (slice metodo):              Slice objects.      (line   16)
* INDIRECT (inspect.BufferFlags attributo): Buffer flags.    (line   31)
* inet_aton() (nel modulo socket):       Other functions<2>. (line  259)
* inet_ntoa() (nel modulo socket):       Other functions<2>. (line  279)
* inet_ntop() (nel modulo socket):       Other functions<2>. (line  314)
* inet_pton() (nel modulo socket):       Other functions<2>. (line  296)
* Inexact (classe in decimal):           Signals.            (line   43)
* inf (nel modulo cmath):                Constants<3>.       (line   20)
* inf (nel modulo math):                 Constants<2>.       (line   24)
* inf (sys.hash_info attributo):         sys — System-specific parameters and functions.
                                                             (line 1079)
* infile (shlex.shlex attributo):        shlex Objects.      (line  140)
* Infinito:                              Funzioni Incorporate.
                                                             (line  753)
* infj (nel modulo cmath):               Constants<3>.       (line   26)
* INFO (nel modulo logging):             Logging Levels.     (line   29)
* INFO (nel modulo tkinter.messagebox):  tkinter messagebox — Tkinter message prompts.
                                                             (line  194)
* info (pathlib.Path attributo):         Querying file type and status.
                                                             (line  170)
* info() (dis.Bytecode metodo):          Bytecode analysis.  (line   68)
* info() (gettext.NullTranslations metodo): The NullTranslations class.
                                                             (line   63)
* info() (http.client.HTTPResponse metodo): HTTPResponse Objects.
                                                             (line   84)
* info() (logging.Logger metodo):        Logger Objects.     (line  290)
* info() (nel modulo logging):           Module-Level Functions.
                                                             (line   64)
* info() (urllib.response.addinfourl metodo): urllib response — Response classes used by urllib.
                                                             (line   35)
* infolist() (zipfile.ZipFile metodo):   ZipFile objects.    (line  124)
* inheritance:                           Class definitions.  (line    6)
* ini file:                              configparser — Configuration file parser.
                                                             (line    8)
* init_color() (nel modulo curses):      Functions<5>.       (line  235)
* init_pair() (nel modulo curses):       Functions<5>.       (line  247)
* init() (nel modulo mimetypes):         mimetypes — Map filenames to MIME types.
                                                             (line   95)
* inited (nel modulo mimetypes):         mimetypes — Map filenames to MIME types.
                                                             (line  134)
* initgroups() (nel modulo os):          Process Parameters. (line  365)
* initial_indent (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  216)
* initproc (C type):                     Slot Type typedefs. (line   35)
* initscr() (nel modulo curses):         Functions<5>.       (line  261)
* InitVar (classe in dataclasses):       Module contents<4>. (line  327)
* inode() (os.DirEntry metodo):          Files and Directories.
                                                             (line  970)
* input:                                 Expression input.   (line    6)
* input_charset (email.charset.Charset attributo): email charset Representing character sets.
                                                             (line   53)
* input_codec (email.charset.Charset attributo): email charset Representing character sets.
                                                             (line   82)
* input() (nel modulo fileinput):        fileinput — Iterate over lines from multiple input streams.
                                                             (line   56)
* InputSource (classe in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers.
                                                             (line   51)
* InputStream (classe in wsgiref.types): wsgiref types – WSGI types for static type checking.
                                                             (line   24)
* inquiry (C type):                      Supporting Cyclic Garbage Collection.
                                                             (line  271)
* insch() (curses.window metodo):        Window Objects.     (line  322)
* insdelln() (curses.window metodo):     Window Objects.     (line  329)
* insert_text() (nel modulo readline):   Line buffer.        (line   13)
* insert() (array.array metodo):         array — Efficient arrays of numeric values.
                                                             (line  209)
* insert() (collections.deque metodo):   deque objects.      (line   78)
* insert() (sequence metodo):            Tipi di Sequenza Mutabili.
                                                             (line  100)
* insert() (tkinter.ttk.Notebook metodo): ttk Notebook.      (line   42)
* insert() (tkinter.ttk.Treeview metodo): ttk Treeview.      (line  183)
* insert() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line  130)
* insertBefore() (xml.dom.Node metodo):  Node Objects.       (line  121)
* insertln() (curses.window metodo):     Window Objects.     (line  337)
* insnstr() (curses.window metodo):      Window Objects.     (line  342)
* insort_left() (nel modulo bisect):     bisect — Array bisection algorithm.
                                                             (line   72)
* insort_right() (nel modulo bisect):    bisect — Array bisection algorithm.
                                                             (line   90)
* insort() (nel modulo bisect):          bisect — Array bisection algorithm.
                                                             (line   90)
* inspect (sys.flags attributo):         sys — System-specific parameters and functions.
                                                             (line  541)
* inspect command line option; -details: Command-line interface<10>.
                                                             (line   13)
* InspectLoader (classe in importlib.abc): importlib abc – Abstract base classes related to import.
                                                             (line  204)
* insstr() (curses.window metodo):       Window Objects.     (line  353)
* install_opener() (nel modulo urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  111)
* install_scripts() (venv.EnvBuilder metodo): API<2>.        (line  184)
* install() (gettext.NullTranslations metodo): The NullTranslations class.
                                                             (line   72)
* install() (nel modulo gettext):        Class-based API.    (line   69)
* installHandler() (nel modulo unittest): Signal Handling.   (line   29)
* instance;call:                         Calls.              (line  159)
* instate() (tkinter.ttk.Widget metodo): ttk Widget.         (line   18)
* instr() (curses.window metodo):        Window Objects.     (line  363)
* instream (shlex.shlex attributo):      shlex Objects.      (line  146)
* Instruction (classe in dis):           Python Bytecode Instructions.
                                                             (line   10)
* INSTRUCTION (monitoring event):        Events.             (line   39)
* Instruction.arg (nel modulo dis):      Python Bytecode Instructions.
                                                             (line   34)
* Instruction.argrepr (nel modulo dis):  Python Bytecode Instructions.
                                                             (line   46)
* Instruction.argval (nel modulo dis):   Python Bytecode Instructions.
                                                             (line   42)
* Instruction.baseopcode (nel modulo dis): Python Bytecode Instructions.
                                                             (line   24)
* Instruction.baseopname (nel modulo dis): Python Bytecode Instructions.
                                                             (line   29)
* Instruction.cache_info (nel modulo dis): Python Bytecode Instructions.
                                                             (line   92)
* Instruction.cache_offset (nel modulo dis): Python Bytecode Instructions.
                                                             (line   61)
* Instruction.end_offset (nel modulo dis): Python Bytecode Instructions.
                                                             (line   65)
* Instruction.is_jump_target (nel modulo dis): Python Bytecode Instructions.
                                                             (line   78)
* Instruction.jump_target (nel modulo dis): Python Bytecode Instructions.
                                                             (line   82)
* Instruction.line_number (nel modulo dis): Python Bytecode Instructions.
                                                             (line   73)
* Instruction.offset (nel modulo dis):   Python Bytecode Instructions.
                                                             (line   51)
* Instruction.oparg (nel modulo dis):    Python Bytecode Instructions.
                                                             (line   38)
* Instruction.opcode (nel modulo dis):   Python Bytecode Instructions.
                                                             (line   14)
* Instruction.opname (nel modulo dis):   Python Bytecode Instructions.
                                                             (line   20)
* Instruction.positions (nel modulo dis): Python Bytecode Instructions.
                                                             (line   87)
* Instruction.start_offset (nel modulo dis): Python Bytecode Instructions.
                                                             (line   55)
* Instruction.starts_line (nel modulo dis): Python Bytecode Instructions.
                                                             (line   69)
* int (classe built-in):                 Funzioni Incorporate.
                                                             (line  993)
* int (uuid.UUID attributo):             uuid — UUID objects according to RFC 9562.
                                                             (line  146)
* int_info (nel modulo sys):             sys — System-specific parameters and functions.
                                                             (line 1193)
* int_max_str_digits (sys.flags attributo): sys — System-specific parameters and functions.
                                                             (line  587)
* Int2AP() (nel modulo imaplib):         imaplib — IMAP4 protocol client.
                                                             (line  120)
* integer:                               Immutable sequences.
                                                             (line   15)
* integer literal:                       Numeric literals.   (line    6)
* integer;representation:                numbers Integral.   (line    9)
* Integral (classe in numbers):          The numeric tower.  (line   59)
* Integrated Development Environment:    IDLE — Python editor and shell<2>.
                                                             (line    8)
* IntegrityError:                        Exceptions<6>.      (line   65)
* IntEnum (classe in enum):              Data Types<2>.      (line  368)
* interact (pdb command):                Debugger commands.  (line  363)
* interact() (code.InteractiveConsole metodo): Interactive Console Objects.
                                                             (line   10)
* interact() (nel modulo code):          code — Interpreter base classes.
                                                             (line   42)
* interactive:                           Glossary.           (line  884)
* Interactive (classe in ast):           Root nodes.         (line   37)
* interactive (sys.flags attributo):     sys — System-specific parameters and functions.
                                                             (line  544)
* interactive mode:                      Complete Python programs.
                                                             (line   19)
* InteractiveConsole (classe in code):   code — Interpreter base classes.
                                                             (line   30)
* InteractiveInterpreter (classe in code): code — Interpreter base classes.
                                                             (line   15)
* InterfaceError:                        Exceptions<6>.      (line   37)
* intern() (nel modulo sys):             sys — System-specific parameters and functions.
                                                             (line 1238)
* internal type:                         Internal types.     (line    6)
* internal_attr (zipfile.ZipInfo attributo): ZipInfo objects.
                                                             (line  138)
* Internaldate2tuple() (nel modulo imaplib): imaplib — IMAP4 protocol client.
                                                             (line  114)
* InternalError:                         Exceptions<6>.      (line   71)
* internalSubset (xml.dom.DocumentType attributo): DocumentType Objects.
                                                             (line   27)
* Internet:                              Internet Protocols and Support.
                                                             (line    6)
* INTERNET_TIMEOUT (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line   82)
* intero;letterali:                      Tipi Numerici — int float complex.
                                                             (line   19)
* interpolated string literal:           Formattazione Avanzata dell’Output.
                                                             (line   98)
* interpolated string literal <1>:       Raw string literals.
                                                             (line   25)
* interpolated string literal <2>:       Metodi per le Stringhe.
                                                             (line  912)
* Interpolation (classe in ast):         Literals<3>.        (line   92)
* Interpolation (classe in string.templatelib): Types.       (line  193)
* InterpolationDepthError:               Exceptions<8>.      (line   42)
* InterpolationError:                    Exceptions<8>.      (line   37)
* InterpolationMissingOptionError:       Exceptions<8>.      (line   49)
* interpolations (string.templatelib.Template attributo): Types.
                                                             (line   74)
* InterpolationSyntaxError:              Exceptions<8>.      (line   54)
* interpolazione, stringa (%):           Formattazione delle stringhe in stile printf.
                                                             (line    6)
* interpolazione;bytearray (%):          Formattazione Bytes stile printf.
                                                             (line    6)
* interpolazione;bytes (%):              Formattazione Bytes stile printf.
                                                             (line    6)
* interpreted:                           Glossary.           (line  894)
* interpreter:                           Top-level components.
                                                             (line    6)
* Interpreter (classe in concurrent.interpreters): Interpreter objects.
                                                             (line    6)
* interpreter lock:                      Thread State and the Global Interpreter Lock.
                                                             (line    6)
* interpreter prompts:                   sys — System-specific parameters and functions.
                                                             (line 1624)
* interpreter shutdown:                  Glossary.           (line  904)
* interpreter_requires_environment() (nel modulo test.support.script_helper): test support script_helper — Utilities for the Python execution tests.
                                                             (line    9)
* InterpreterError:                      Exceptions<12>.     (line    6)
* InterpreterNotFoundError:              Exceptions<12>.     (line   11)
* InterpreterPoolExecutor (classe in concurrent.futures): InterpreterPoolExecutor.
                                                             (line   54)
* interrupt_main() (nel modulo _thread): _thread — Low-level threading API.
                                                             (line   56)
* interrupt() (multiprocessing.Process metodo): Process and exceptions.
                                                             (line  205)
* interrupt() (sqlite3.Connection metodo): Connection objects.
                                                             (line  340)
* InterruptedError:                      OS exceptions.      (line   73)
* interruzioni di riga universali;open() funzione incorporata: Funzioni Incorporate.
                                                             (line 1473)
* intersection_update() (set metodo):    Tipi di Insiemi — set frozenset.
                                                             (line  187)
* intersection() (frozenset metodo):     Tipi di Insiemi — set frozenset.
                                                             (line  110)
* intersection() (set metodo):           Tipi di Insiemi — set frozenset.
                                                             (line  110)
* IntFlag (classe in enum):              Data Types<2>.      (line  548)
* intro (cmd.Cmd attributo):             Cmd Objects.        (line  150)
* InuseAttributeErr:                     Exceptions<22>.     (line   39)
* inv_cdf() (statistics.NormalDist metodo): NormalDist objects.
                                                             (line   92)
* inv() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line  114)
* InvalidAccessErr:                      Exceptions<22>.     (line   44)
* invalidate_caches() (importlib.abc.MetaPathFinder metodo): importlib abc – Abstract base classes related to import.
                                                             (line   49)
* invalidate_caches() (importlib.abc.PathEntryFinder metodo): importlib abc – Abstract base classes related to import.
                                                             (line   84)
* invalidate_caches() (importlib.machinery.FileFinder metodo): importlib machinery – Importers and path hooks.
                                                             (line  191)
* invalidate_caches() (importlib.machinery.PathFinder metodo della classe): importlib machinery – Importers and path hooks.
                                                             (line  140)
* invalidate_caches() (nel modulo importlib): Functions<12>. (line   41)
* invalidate_caches() (nel modulo platform): Cross platform. (line  167)
* invalidate_caches() (zipimport.zipimporter metodo): zipimporter Objects.
                                                             (line   89)
* InvalidBase64CharactersDefect:         email errors Exception and Defect classes.
                                                             (line  129)
* InvalidBase64LengthDefect:             email errors Exception and Defect classes.
                                                             (line  135)
* InvalidBase64PaddingDefect:            email errors Exception and Defect classes.
                                                             (line  123)
* InvalidCharacterErr:                   Exceptions<22>.     (line   49)
* InvalidDateDefect:                     email errors Exception and Defect classes.
                                                             (line  141)
* InvalidFileException:                  plistlib — Generate and parse Apple plist files.
                                                             (line  170)
* InvalidModificationErr:                Exceptions<22>.     (line   57)
* InvalidOperation (classe in decimal):  Signals.            (line   51)
* InvalidStateErr:                       Exceptions<22>.     (line   61)
* InvalidStateError:                     Exception classes.  (line   26)
* InvalidStateError <1>:                 Exceptions<15>.     (line   30)
* InvalidTZPathWarning:                  Exceptions and warnings.
                                                             (line   12)
* InvalidURL:                            http client — HTTP protocol client.
                                                             (line  141)
* InvalidWriteError:                     Exceptions<8>.      (line   87)
* inversion:                             Unary arithmetic and bitwise operations.
                                                             (line   18)
* Invert (classe in ast):                Expressions<2>.     (line   27)
* invert() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line  114)
* invocation:                            Callable types.     (line    6)
* IO (classe in typing):                 ABCs and Protocols for working with I/O.
                                                             (line    6)
* IO_REPARSE_TAG_APPEXECLINK (nel modulo stat): stat — Interpreting stat results.
                                                             (line  477)
* IO_REPARSE_TAG_MOUNT_POINT (nel modulo stat): stat — Interpreting stat results.
                                                             (line  477)
* IO_REPARSE_TAG_SYMLINK (nel modulo stat): stat — Interpreting stat results.
                                                             (line  477)
* IOBase (classe in io):                 I/O Base Classes.   (line    6)
* IOCTL_VM_SOCKETS_GET_LOCAL_CID (nel modulo socket): Constants<8>.
                                                             (line  283)
* ioctl() (nel modulo fcntl):            fcntl — The fcntl and ioctl system calls.
                                                             (line  110)
* ioctl() (socket.socket metodo):        Socket Objects.     (line  180)
* IOError:                               Concrete exceptions.
                                                             (line  513)
* ior() (nel modulo operator):           In-place Operators. (line   79)
* ios_ver() (nel modulo platform):       iOS platform.       (line    6)
* ip (ipaddress.IPv4Interface attributo): Interface objects. (line   19)
* ip (ipaddress.IPv6Interface attributo): Interface objects. (line   74)
* ip_address() (nel modulo ipaddress):   Convenience factory functions.
                                                             (line    9)
* ip_interface() (nel modulo ipaddress): Convenience factory functions.
                                                             (line   37)
* ip_network() (nel modulo ipaddress):   Convenience factory functions.
                                                             (line   23)
* ipow() (nel modulo operator):          In-place Operators. (line   84)
* ipv4_mapped (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  303)
* IPv4Address (classe in ipaddress):     Address objects.    (line   13)
* IPv4Interface (classe in ipaddress):   Interface objects.  (line    9)
* IPv4Network (classe in ipaddress):     Network objects.    (line   13)
* IPV6_ENABLED (nel modulo test.support.socket_helper): test support socket_helper — Utilities for socket tests.
                                                             (line   11)
* ipv6_mapped (ipaddress.IPv4Address attributo): Address objects.
                                                             (line  192)
* IPv6Address (classe in ipaddress):     Address objects.    (line  224)
* IPv6Interface (classe in ipaddress):   Interface objects.  (line   64)
* IPv6Network (classe in ipaddress):     Network objects.    (line  253)
* irrefutable case block:                Irrefutable Case Blocks.
                                                             (line    6)
* irshift() (nel modulo operator):       In-place Operators. (line   89)
* Is (classe in ast):                    Expressions<2>.     (line  108)
* is_() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line   63)
* is_absolute() (pathlib.PurePath metodo): Methods and properties.
                                                             (line  189)
* is_active() (graphlib.TopologicalSorter metodo): graphlib — Functionality to operate with graph-like structures.
                                                             (line  118)
* is_alive() (multiprocessing.Process metodo): Process and exceptions.
                                                             (line  126)
* is_alive() (threading.Thread metodo):  Thread objects.     (line  231)
* is_android (nel modulo test.support):  test support — Utilities for the Python test suite.
                                                             (line   40)
* is_annotated() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  239)
* is_anonymous (ctypes.CField attributo): Structured data types.
                                                             (line  299)
* is_apple (nel modulo test.support):    test support — Utilities for the Python test suite.
                                                             (line   56)
* is_apple_mobile (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line   52)
* is_assigned() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  270)
* is_async (pyclbr.Function attributo):  Function Objects.   (line   41)
* is_attachment() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  445)
* is_authenticated() (urllib.request.HTTPPasswordMgrWithPriorAuth metodo): HTTPPasswordMgrWithPriorAuth Objects.
                                                             (line   30)
* is_bitfield (ctypes.CField attributo): Structured data types.
                                                             (line  281)
* is_block_device() (pathlib.Path metodo): Querying file type and status.
                                                             (line  137)
* is_blocked() (http.cookiejar.DefaultCookiePolicy metodo): DefaultCookiePolicy Objects.
                                                             (line   60)
* is_canonical() (decimal.Context metodo): Context objects.  (line  332)
* is_canonical() (decimal.Decimal metodo): Decimal objects.  (line  295)
* is_char_device() (pathlib.Path metodo): Querying file type and status.
                                                             (line  144)
* IS_CHARACTER_JUNK() (nel modulo difflib): difflib — Helpers for computing deltas.
                                                             (line  362)
* is_check_supported() (nel modulo lzma): Miscellaneous<3>.  (line    6)
* is_closed() (asyncio.loop metodo):     Running and stopping the loop.
                                                             (line   39)
* is_closing() (asyncio.BaseTransport metodo): Base Transport.
                                                             (line   17)
* is_closing() (asyncio.StreamWriter metodo): StreamWriter.  (line  110)
* is_comp_cell() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  281)
* is_comp_iter() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  274)
* is_dataclass() (nel modulo dataclasses): Module contents<4>.
                                                             (line  477)
* is_declared_global() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  230)
* is_dir() (importlib.resources.abc.Traversable metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line  106)
* is_dir() (os.DirEntry metodo):         Files and Directories.
                                                             (line  981)
* is_dir() (pathlib.Path metodo):        Querying file type and status.
                                                             (line   80)
* is_dir() (pathlib.types.PathInfo metodo): Protocols.       (line   26)
* is_dir() (zipfile.Path metodo):        Path objects.       (line   57)
* is_dir() (zipfile.ZipInfo metodo):     ZipInfo objects.    (line   43)
* is_emscripten (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line   44)
* is_enabled() (nel modulo faulthandler): Fault handler state.
                                                             (line   42)
* is_expired() (http.cookiejar.Cookie metodo): Cookie Objects<2>.
                                                             (line  113)
* is_fifo() (pathlib.Path metodo):       Querying file type and status.
                                                             (line  130)
* is_file() (importlib.resources.abc.Traversable metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line  110)
* is_file() (os.DirEntry metodo):        Files and Directories.
                                                             (line 1010)
* is_file() (pathlib.Path metodo):       Querying file type and status.
                                                             (line   67)
* is_file() (pathlib.types.PathInfo metodo): Protocols.      (line   37)
* is_file() (zipfile.Path metodo):       Path objects.       (line   61)
* is_finalized() (nel modulo gc):        gc — Garbage Collector interface.
                                                             (line  217)
* is_finalizing() (nel modulo sys):      sys — System-specific parameters and functions.
                                                             (line 1264)
* is_finite() (decimal.Context metodo):  Context objects.    (line  336)
* is_finite() (decimal.Decimal metodo):  Decimal objects.    (line  302)
* is_free_class() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  250)
* is_free() (symtable.Symbol metodo):    Examining Symbol Tables.
                                                             (line  245)
* is_global (ipaddress.IPv4Address attributo): Address objects.
                                                             (line  139)
* is_global (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  283)
* is_global() (symtable.Symbol metodo):  Examining Symbol Tables.
                                                             (line  222)
* is_hop_by_hop() (nel modulo wsgiref.util): wsgiref util – WSGI environment utilities.
                                                             (line  112)
* is_imported() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  207)
* is_infinite() (decimal.Context metodo): Context objects.   (line  340)
* is_infinite() (decimal.Decimal metodo): Decimal objects.   (line  307)
* is_integer() (float metodo):           Metodi aggiuntivi su Float.
                                                             (line   33)
* is_integer() (fractions.Fraction metodo): fractions — Rational numbers.
                                                             (line  134)
* is_integer() (int metodo):             Metodi Aggiuntivi sui Tipi Integer.
                                                             (line  174)
* is_junction() (os.DirEntry metodo):    Files and Directories.
                                                             (line 1045)
* is_junction() (pathlib.Path metodo):   Querying file type and status.
                                                             (line  101)
* is_jython (nel modulo test.support):   test support — Utilities for the Python test suite.
                                                             (line   36)
* IS_LINE_JUNK() (nel modulo difflib):   difflib — Helpers for computing deltas.
                                                             (line  355)
* is_linetouched() (curses.window metodo): Window Objects.   (line  377)
* is_link_local (ipaddress.IPv4Address attributo): Address objects.
                                                             (line  187)
* is_link_local (ipaddress.IPv4Network attributo): Network objects.
                                                             (line   80)
* is_link_local (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  293)
* is_link_local (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  308)
* is_local() (symtable.Symbol metodo):   Examining Symbol Tables.
                                                             (line  235)
* is_loopback (ipaddress.IPv4Address attributo): Address objects.
                                                             (line  182)
* is_loopback (ipaddress.IPv4Network attributo): Network objects.
                                                             (line   78)
* is_loopback (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  291)
* is_loopback (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  306)
* is_mount() (pathlib.Path metodo):      Querying file type and status.
                                                             (line  108)
* is_multicast (ipaddress.IPv4Address attributo): Address objects.
                                                             (line   96)
* is_multicast (ipaddress.IPv4Network attributo): Network objects.
                                                             (line   70)
* is_multicast (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  279)
* is_multicast (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  298)
* is_multipart() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  134)
* is_multipart() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  146)
* is_namespace() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  288)
* is_nan() (decimal.Context metodo):     Context objects.    (line  344)
* is_nan() (decimal.Decimal metodo):     Decimal objects.    (line  312)
* is_nested() (symtable.SymbolTable metodo): Examining Symbol Tables.
                                                             (line   94)
* is_none() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line   71)
* is_nonlocal() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  226)
* is_normal() (decimal.Context metodo):  Context objects.    (line  349)
* is_normal() (decimal.Decimal metodo):  Decimal objects.    (line  317)
* is_normalized() (nel modulo unicodedata): unicodedata — Unicode Database.
                                                             (line  169)
* is_not_allowed() (http.cookiejar.DefaultCookiePolicy metodo): DefaultCookiePolicy Objects.
                                                             (line   74)
* is_not_none() (nel modulo operator):   operator — Standard operators as functions.
                                                             (line   77)
* is_not() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line   67)
* IS_OP (opcode):                        Python Bytecode Instructions.
                                                             (line  829)
* is_optimized() (symtable.SymbolTable metodo): Examining Symbol Tables.
                                                             (line   90)
* is_package() (importlib.abc.InspectLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  236)
* is_package() (importlib.abc.SourceLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  427)
* is_package() (importlib.machinery.ExtensionFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  329)
* is_package() (importlib.machinery.SourceFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  221)
* is_package() (importlib.machinery.SourcelessFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  265)
* is_package() (zipimport.zipimporter metodo): zipimporter Objects.
                                                             (line   73)
* is_parameter() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  212)
* is_private (ipaddress.IPv4Address attributo): Address objects.
                                                             (line  101)
* is_private (ipaddress.IPv4Network attributo): Network objects.
                                                             (line   72)
* is_private (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  281)
* is_private (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  300)
* is_protocol() (nel modulo typing):     Introspection helpers.
                                                             (line  119)
* is_python_build() (nel modulo sysconfig): Other functions<3>.
                                                             (line   46)
* is_qnan() (decimal.Context metodo):    Context objects.    (line  354)
* is_qnan() (decimal.Decimal metodo):    Decimal objects.    (line  323)
* is_reading() (asyncio.ReadTransport metodo): Read-only Transports.
                                                             (line    6)
* is_referenced() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  203)
* is_relative_to() (pathlib.PurePath metodo): Methods and properties.
                                                             (line  208)
* is_reserved (ipaddress.IPv4Address attributo): Address objects.
                                                             (line  167)
* is_reserved (ipaddress.IPv4Network attributo): Network objects.
                                                             (line   76)
* is_reserved (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  289)
* is_reserved (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  304)
* is_reserved() (pathlib.PurePath metodo): Methods and properties.
                                                             (line  232)
* is_resource_enabled() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  262)
* is_resource() (importlib.resources.abc.ResourceReader metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line   62)
* is_resource() (nel modulo importlib.resources): Functional API.
                                                             (line  136)
* is_running() (asyncio.loop metodo):    Running and stopping the loop.
                                                             (line   35)
* is_running() (concurrent.interpreters.Interpreter metodo): Interpreter objects.
                                                             (line   26)
* is_safe (uuid.UUID attributo):         uuid — UUID objects according to RFC 9562.
                                                             (line  168)
* is_serving() (asyncio.Server metodo):  Server Objects.     (line  117)
* is_set() (asyncio.Event metodo):       Event.              (line   65)
* is_set() (threading.Event metodo):     Event objects.      (line   25)
* is_signed() (decimal.Context metodo):  Context objects.    (line  359)
* is_signed() (decimal.Decimal metodo):  Decimal objects.    (line  328)
* is_site_local (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  295)
* is_site_local (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  358)
* is_skipped_module() (bdb.Bdb metodo):  bdb — Debugger framework.
                                                             (line  271)
* is_snan() (decimal.Context metodo):    Context objects.    (line  363)
* is_snan() (decimal.Decimal metodo):    Decimal objects.    (line  334)
* is_socket() (pathlib.Path metodo):     Querying file type and status.
                                                             (line  123)
* is_stack_trampoline_active() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line 1916)
* is_subnormal() (decimal.Context metodo): Context objects.  (line  368)
* is_subnormal() (decimal.Decimal metodo): Decimal objects.  (line  339)
* is_symlink() (os.DirEntry metodo):     Files and Directories.
                                                             (line 1026)
* is_symlink() (pathlib.Path metodo):    Querying file type and status.
                                                             (line   93)
* is_symlink() (pathlib.types.PathInfo metodo): Protocols.   (line   48)
* is_symlink() (zipfile.Path metodo):    Path objects.       (line   65)
* is_tarfile() (nel modulo tarfile):     tarfile — Read and write tar archive files.
                                                             (line  235)
* is_term_resized() (nel modulo curses): Functions<5>.       (line  269)
* is_tracing() (nel modulo tracemalloc): Functions<10>.      (line   61)
* is_tracked() (nel modulo gc):          gc — Garbage Collector interface.
                                                             (line  194)
* is_type_parameter() (symtable.Symbol metodo): Examining Symbol Tables.
                                                             (line  216)
* is_typeddict() (nel modulo typing):    Introspection helpers.
                                                             (line  134)
* is_unspecified (ipaddress.IPv4Address attributo): Address objects.
                                                             (line  162)
* is_unspecified (ipaddress.IPv4Network attributo): Network objects.
                                                             (line   74)
* is_unspecified (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  287)
* is_unspecified (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  302)
* is_valid() (string.Template metodo):   Template strings $-strings.
                                                             (line   77)
* is_wasi (nel modulo test.support):     test support — Utilities for the Python test suite.
                                                             (line   48)
* is_wintouched() (curses.window metodo): Window Objects.    (line  384)
* is_zero() (decimal.Context metodo):    Context objects.    (line  372)
* is_zero() (decimal.Decimal metodo):    Decimal objects.    (line  344)
* is_zipfile() (nel modulo zipfile):     zipfile — Work with ZIP archives.
                                                             (line   93)
* isabs() (nel modulo os.path):          os path — Common pathname manipulations.
                                                             (line  206)
* isabstract() (nel modulo inspect):     Types and members.  (line  574)
* IsADirectoryError:                     OS exceptions.      (line   83)
* isalnum() (bytearray metodo):          Operazioni su Bytes e Bytearray.
                                                             (line  526)
* isalnum() (bytes metodo):              Operazioni su Bytes e Bytearray.
                                                             (line  526)
* isalnum() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  134)
* isalnum() (str metodo):                Metodi per le Stringhe.
                                                             (line  256)
* isalpha() (bytearray metodo):          Operazioni su Bytes e Bytearray.
                                                             (line  544)
* isalpha() (bytes metodo):              Operazioni su Bytes e Bytearray.
                                                             (line  544)
* isalpha() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  139)
* isalpha() (str metodo):                Metodi per le Stringhe.
                                                             (line  264)
* isascii() (bytearray metodo):          Operazioni su Bytes e Bytearray.
                                                             (line  559)
* isascii() (bytes metodo):              Operazioni su Bytes e Bytearray.
                                                             (line  559)
* isascii() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  144)
* isascii() (str metodo):                Metodi per le Stringhe.
                                                             (line  284)
* isasyncgen() (nel modulo inspect):     Types and members.  (line  534)
* isasyncgenfunction() (nel modulo inspect): Types and members.
                                                             (line  513)
* isatty() (io.IOBase metodo):           I/O Base Classes.   (line   73)
* isatty() (nel modulo os):              File Descriptor Operations.
                                                             (line  261)
* isawaitable() (nel modulo inspect):    Types and members.  (line  492)
* isblank() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  148)
* isblk() (tarfile.TarInfo metodo):      TarInfo Objects.    (line  210)
* isbuiltin() (nel modulo inspect):      Types and members.  (line  554)
* ischr() (tarfile.TarInfo metodo):      TarInfo Objects.    (line  206)
* isclass() (nel modulo inspect):        Types and members.  (line  413)
* isclose() (nel modulo cmath):          Classification functions.
                                                             (line   23)
* isclose() (nel modulo math):           Floating point manipulation functions.
                                                             (line   25)
* iscntrl() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  152)
* iscode() (nel modulo inspect):         Types and members.  (line  550)
* iscoroutine() (nel modulo asyncio):    Introspection.      (line   26)
* iscoroutine() (nel modulo inspect):    Types and members.  (line  485)
* iscoroutinefunction() (nel modulo inspect): Types and members.
                                                             (line  449)
* isctrl() (nel modulo curses.ascii):    curses ascii — Utilities for ASCII characters.
                                                             (line  193)
* isDaemon() (threading.Thread metodo):  Thread objects.     (line  253)
* isdatadescriptor() (nel modulo inspect): Types and members.
                                                             (line  601)
* isdecimal() (str metodo):              Metodi per le Stringhe.
                                                             (line  297)
* isdev() (tarfile.TarInfo metodo):      TarInfo Objects.    (line  218)
* isdevdrive() (nel modulo os.path):     os path — Common pathname manipulations.
                                                             (line  274)
* isdigit() (bytearray metodo):          Operazioni su Bytes e Bytearray.
                                                             (line  568)
* isdigit() (bytes metodo):              Operazioni su Bytes e Bytearray.
                                                             (line  568)
* isdigit() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  157)
* isdigit() (str metodo):                Metodi per le Stringhe.
                                                             (line  313)
* isdir() (nel modulo os.path):          os path — Common pathname manipulations.
                                                             (line  230)
* isdir() (tarfile.TarInfo metodo):      TarInfo Objects.    (line  194)
* isdisjoint() (frozenset metodo):       Tipi di Insiemi — set frozenset.
                                                             (line   71)
* isdisjoint() (set metodo):             Tipi di Insiemi — set frozenset.
                                                             (line   71)
* isdown() (nel modulo turtle):          Drawing state.      (line   86)
* iselement() (nel modulo xml.etree.ElementTree): Functions<8>.
                                                             (line  130)
* isenabled() (nel modulo gc):           gc — Garbage Collector interface.
                                                             (line   30)
* isEnabledFor() (logging.Logger metodo): Logger Objects.    (line  144)
* isendwin() (nel modulo curses):        Functions<5>.       (line  274)
* ISEOF() (nel modulo token):            token — Constants used with Python parse trees.
                                                             (line   39)
* isfifo() (tarfile.TarInfo metodo):     TarInfo Objects.    (line  214)
* isfile() (nel modulo os.path):         os path — Common pathname manipulations.
                                                             (line  222)
* isfile() (tarfile.TarInfo metodo):     TarInfo Objects.    (line  185)
* isfinite() (nel modulo cmath):         Classification functions.
                                                             (line    6)
* isfinite() (nel modulo math):          Floating point manipulation functions.
                                                             (line   60)
* isfirstline() (nel modulo fileinput):  fileinput — Iterate over lines from multiple input streams.
                                                             (line  111)
* isframe() (nel modulo inspect):        Types and members.  (line  546)
* isfunction() (nel modulo inspect):     Types and members.  (line  428)
* isfuture() (nel modulo asyncio):       Future Functions.   (line    6)
* isgenerator() (nel modulo inspect):    Types and members.  (line  445)
* isgeneratorfunction() (nel modulo inspect): Types and members.
                                                             (line  433)
* isgetsetdescriptor() (nel modulo inspect): Types and members.
                                                             (line  614)
* isgraph() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  162)
* isidentifier() (str metodo):           Metodi per le Stringhe.
                                                             (line  323)
* isinf() (nel modulo cmath):            Classification functions.
                                                             (line   13)
* isinf() (nel modulo math):             Floating point manipulation functions.
                                                             (line   67)
* isjunction() (nel modulo os.path):     os path — Common pathname manipulations.
                                                             (line  238)
* iskeyword() (nel modulo keyword):      keyword — Testing for Python keywords.
                                                             (line   13)
* isleap() (nel modulo calendar):        calendar — General calendar-related functions.
                                                             (line  364)
* islice() (nel modulo itertools):       Itertool Functions. (line  370)
* islink() (nel modulo os.path):         os path — Common pathname manipulations.
                                                             (line  246)
* islnk() (tarfile.TarInfo metodo):      TarInfo Objects.    (line  202)
* islower() (bytearray metodo):          Operazioni su Bytes e Bytearray.
                                                             (line  583)
* islower() (bytes metodo):              Operazioni su Bytes e Bytearray.
                                                             (line  583)
* islower() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  166)
* islower() (str metodo):                Metodi per le Stringhe.
                                                             (line  342)
* ismemberdescriptor() (nel modulo inspect): Types and members.
                                                             (line  623)
* ismeta() (nel modulo curses.ascii):    curses ascii — Utilities for ASCII characters.
                                                             (line  197)
* ismethod() (nel modulo inspect):       Types and members.  (line  418)
* ismethoddescriptor() (nel modulo inspect): Types and members.
                                                             (line  578)
* ismethodwrapper() (nel modulo inspect): Types and members. (line  559)
* ismodule() (nel modulo inspect):       Types and members.  (line  409)
* ismount() (nel modulo os.path):        os path — Common pathname manipulations.
                                                             (line  254)
* isnan() (nel modulo cmath):            Classification functions.
                                                             (line   18)
* isnan() (nel modulo math):             Floating point manipulation functions.
                                                             (line   72)
* ISNONTERMINAL() (nel modulo token):    token — Constants used with Python parse trees.
                                                             (line   35)
* IsNot (classe in ast):                 Expressions<2>.     (line  108)
* isnumeric() (str metodo):              Metodi per le Stringhe.
                                                             (line  349)
* isocalendar() (datetime.date metodo):  date Objects.       (line  274)
* isocalendar() (datetime.datetime metodo): datetime Objects.
                                                             (line  649)
* isoformat() (datetime.date metodo):    date Objects.       (line  301)
* isoformat() (datetime.datetime metodo): datetime Objects.  (line  654)
* isoformat() (datetime.time metodo):    time Objects.       (line  181)
* isolated (sys.flags attributo):        sys — System-specific parameters and functions.
                                                             (line  547)
* IsolatedAsyncioTestCase (classe in unittest): Test cases.  (line  917)
* isolation_level (sqlite3.Connection attributo): Connection objects.
                                                             (line  777)
* isoweekday() (datetime.date metodo):   date Objects.       (line  267)
* isoweekday() (datetime.datetime metodo): datetime Objects. (line  643)
* ispackage() (nel modulo inspect):      Types and members.  (line  422)
* isprint() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  170)
* isprintable() (str metodo):            Metodi per le Stringhe.
                                                             (line  371)
* ispunct() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  174)
* isqrt() (nel modulo math):             Number-theoretic functions.
                                                             (line   43)
* isreadable() (nel modulo pprint):      Functions<3>.       (line   85)
* isreadable() (pprint.PrettyPrinter metodo): PrettyPrinter Objects.
                                                             (line   67)
* isrecursive() (nel modulo pprint):     Functions<3>.       (line   94)
* isrecursive() (pprint.PrettyPrinter metodo): PrettyPrinter Objects.
                                                             (line   75)
* isreg() (tarfile.TarInfo metodo):      TarInfo Objects.    (line  190)
* isreserved() (nel modulo os.path):     os path — Common pathname manipulations.
                                                             (line  293)
* isReservedKey() (http.cookies.Morsel metodo): Morsel Objects.
                                                             (line   79)
* isroutine() (nel modulo inspect):      Types and members.  (line  569)
* isSameNode() (xml.dom.Node metodo):    Node Objects.       (line  102)
* issoftkeyword() (nel modulo keyword):  keyword — Testing for Python keywords.
                                                             (line   24)
* isspace() (bytearray metodo):          Operazioni su Bytes e Bytearray.
                                                             (line  600)
* isspace() (bytes metodo):              Operazioni su Bytes e Bytearray.
                                                             (line  600)
* isspace() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  179)
* isspace() (str metodo):                Metodi per le Stringhe.
                                                             (line  395)
* isstdin() (nel modulo fileinput):      fileinput — Iterate over lines from multiple input streams.
                                                             (line  116)
* issubset() (frozenset metodo):         Tipi di Insiemi — set frozenset.
                                                             (line   78)
* issubset() (set metodo):               Tipi di Insiemi — set frozenset.
                                                             (line   78)
* issuperset() (frozenset metodo):       Tipi di Insiemi — set frozenset.
                                                             (line   90)
* issuperset() (set metodo):             Tipi di Insiemi — set frozenset.
                                                             (line   90)
* issym() (tarfile.TarInfo metodo):      TarInfo Objects.    (line  198)
* ISTERMINAL() (nel modulo token):       token — Constants used with Python parse trees.
                                                             (line   31)
* istitle() (bytearray metodo):          Operazioni su Bytes e Bytearray.
                                                             (line  609)
* istitle() (bytes metodo):              Operazioni su Bytes e Bytearray.
                                                             (line  609)
* istitle() (str metodo):                Metodi per le Stringhe.
                                                             (line  405)
* istraceback() (nel modulo inspect):    Types and members.  (line  542)
* istruzione;del:                        Tipi di Sequenza Mutabili.
                                                             (line   17)
* istruzione;del <1>:                    Tipi di Mapping — dict.
                                                             (line    6)
* istruzione;if:                         Test del Valore di Verità.
                                                             (line    6)
* istruzione;import:                     Funzioni Incorporate.
                                                             (line 2289)
* istruzione;while:                      Test del Valore di Verità.
                                                             (line    6)
* isub() (nel modulo operator):          In-place Operators. (line   94)
* isupper() (bytearray metodo):          Operazioni su Bytes e Bytearray.
                                                             (line  624)
* isupper() (bytes metodo):              Operazioni su Bytes e Bytearray.
                                                             (line  624)
* isupper() (nel modulo curses.ascii):   curses ascii — Utilities for ASCII characters.
                                                             (line  184)
* isupper() (str metodo):                Metodi per le Stringhe.
                                                             (line  424)
* isvisible() (nel modulo turtle):       Visibility.         (line   22)
* isxdigit() (nel modulo curses.ascii):  curses ascii — Utilities for ASCII characters.
                                                             (line  188)
* ITALIC (nel modulo tkinter.font):      tkinter font — Tkinter font wrapper.
                                                             (line   15)
* item selection:                        Sequences.          (line    6)
* item() (tkinter.ttk.Treeview metodo):  ttk Treeview.       (line  202)
* item() (xml.dom.NamedNodeMap metodo):  NamedNodeMap Objects.
                                                             (line   12)
* item() (xml.dom.NodeList metodo):      NodeList Objects.   (line   15)
* itemgetter() (nel modulo operator):    operator — Standard operators as functions.
                                                             (line  283)
* items() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  271)
* items() (contextvars.Context metodo):  Manual Context Management.
                                                             (line  141)
* items() (dict metodo):                 Tipi di Mapping — dict.
                                                             (line  193)
* items() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  240)
* items() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  352)
* items() (mailbox.Mailbox metodo):      Mailbox objects.    (line  143)
* items() (types.MappingProxyType metodo): Standard Interpreter Types.
                                                             (line  271)
* items() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line   71)
* itemsize (array.array attributo):      array — Efficient arrays of numeric values.
                                                             (line  117)
* itemsize (memoryview attributo):       Memory Views.       (line  475)
* ItemsView (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  125)
* ItemsView (classe in typing):          Aliases to container ABCs in collections abc.
                                                             (line   55)
* iter_attachments() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  560)
* iter_child_nodes() (nel modulo ast):   ast helpers.        (line  172)
* iter_fields() (nel modulo ast):        ast helpers.        (line  167)
* iter_importers() (nel modulo pkgutil): pkgutil — Package extension utility.
                                                             (line   69)
* iter_modules() (nel modulo pkgutil):   pkgutil — Package extension utility.
                                                             (line   87)
* iter_parts() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  576)
* iter_unpack() (nel modulo struct):     Functions and Exceptions.
                                                             (line   42)
* iter_unpack() (struct.Struct metodo):  Classes<2>.         (line   46)
* iter() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line  136)
* iter() (xml.etree.ElementTree.ElementTree metodo): ElementTree Objects.
                                                             (line   40)
* iterable:                              Glossary.           (line  919)
* Iterable (classe in collections.abc):  Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   26)
* Iterable (classe in typing):           Aliases to other ABCs in collections abc.
                                                             (line    6)
* iterable;unpacking:                    Expression lists.   (line   18)
* iterator:                              Glossary.           (line  941)
* Iterator (classe in collections.abc):  Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   43)
* Iterator (classe in typing):           Aliases to other ABCs in collections abc.
                                                             (line   14)
* iterdecode() (nel modulo codecs):      codecs — Codec registry and base classes.
                                                             (line  247)
* iterdir() (importlib.resources.abc.Traversable metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line  102)
* iterdir() (pathlib.Path metodo):       Reading directories.
                                                             (line    6)
* iterdir() (zipfile.Path metodo):       Path objects.       (line   53)
* iterdump() (sqlite3.Connection metodo): Connection objects.
                                                             (line  502)
* iterencode() (json.JSONEncoder metodo): Encoders and Decoders.
                                                             (line  229)
* iterencode() (nel modulo codecs):      codecs — Codec registry and base classes.
                                                             (line  234)
* iterfind() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line  147)
* iterfind() (xml.etree.ElementTree.ElementTree metodo): ElementTree Objects.
                                                             (line   47)
* iteritems() (mailbox.Mailbox metodo):  Mailbox objects.    (line  134)
* iterkeys() (mailbox.Mailbox metodo):   Mailbox objects.    (line  108)
* itermonthdates() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line   67)
* itermonthdays() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line   75)
* itermonthdays2() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line   83)
* itermonthdays3() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line   91)
* itermonthdays4() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line  101)
* iternextfunc (C type):                 Slot Type typedefs. (line   90)
* iterparse() (nel modulo xml.etree.ElementTree): Functions<8>.
                                                             (line  136)
* itertext() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line  156)
* itervalues() (mailbox.Mailbox metodo): Mailbox objects.    (line  117)
* iterweekdays() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line   61)
* ITIMER_PROF (nel modulo signal):       Module contents<2>. (line  251)
* ITIMER_REAL (nel modulo signal):       Module contents<2>. (line  241)
* ITIMER_VIRTUAL (nel modulo signal):    Module contents<2>. (line  246)
* ItimerError:                           Module contents<2>. (line  284)
* itruediv() (nel modulo operator):      In-place Operators. (line   99)
* ixor() (nel modulo operator):          In-place Operators. (line  104)
* j;in numeric literal:                  Floating-point literals.
                                                             (line   56)
* JANUARY (nel modulo calendar):         calendar — General calendar-related functions.
                                                             (line  490)
* java_ver() (nel modulo platform):      Java platform.      (line    6)
* Java;language:                         numbers Real float. (line    6)
* job_size (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  233)
* join_thread() (multiprocessing.Queue metodo): Pipes and Queues.
                                                             (line  190)
* join_thread() (nel modulo test.support.threading_helper): test support threading_helper — Utilities for threading tests.
                                                             (line   11)
* join() (asyncio.Queue metodo):         Queue.              (line   53)
* join() (bytearray metodo):             Operazioni su Bytes e Bytearray.
                                                             (line  173)
* join() (bytes metodo):                 Operazioni su Bytes e Bytearray.
                                                             (line  173)
* join() (multiprocessing.JoinableQueue metodo): Pipes and Queues.
                                                             (line  281)
* join() (multiprocessing.pool.Pool metodo): Process Pools.  (line  188)
* join() (multiprocessing.Process metodo): Process and exceptions.
                                                             (line   99)
* join() (nel modulo os.path):           os path — Common pathname manipulations.
                                                             (line  315)
* join() (nel modulo shlex):             shlex — Simple lexical analysis.
                                                             (line   29)
* join() (queue.Queue metodo):           Queue Objects.      (line   88)
* join() (str metodo):                   Metodi per le Stringhe.
                                                             (line  439)
* join() (threading.Thread metodo):      Thread objects.     (line  147)
* JoinableQueue (classe in multiprocessing): Pipes and Queues.
                                                             (line  257)
* JoinedStr (classe in ast):             Literals<3>.        (line   42)
* joinpath() (importlib.resources.abc.Traversable metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line  114)
* joinpath() (pathlib.PurePath metodo):  Methods and properties.
                                                             (line  246)
* joinpath() (zipfile.Path metodo):      Path objects.       (line  114)
* js_output() (http.cookies.BaseCookie metodo): Cookie Objects.
                                                             (line   32)
* js_output() (http.cookies.Morsel metodo): Morsel Objects.  (line   90)
* json command line option; -compact:    Command-line options<4>.
                                                             (line   48)
* json command line option; -h:          Command-line options<4>.
                                                             (line   54)
* json command line option; -help:       Command-line options<4>.
                                                             (line   54)
* json command line option; -indent:     Command-line options<4>.
                                                             (line   48)
* json command line option; -json-lines: Command-line options<4>.
                                                             (line   42)
* json command line option; -no-ensure-ascii: Command-line options<4>.
                                                             (line   35)
* json command line option; -no-indent:  Command-line options<4>.
                                                             (line   48)
* json command line option; -sort-keys:  Command-line options<4>.
                                                             (line   29)
* json command line option; -tab:        Command-line options<4>.
                                                             (line   48)
* json command line option; infile:      Command-line options<4>.
                                                             (line    6)
* json command line option; outfile:     Command-line options<4>.
                                                             (line   24)
* JSONDecodeError:                       Exceptions<19>.     (line    6)
* JSONDecoder (classe in json):          Encoders and Decoders.
                                                             (line    6)
* JSONEncoder (classe in json):          Encoders and Decoders.
                                                             (line  104)
* JULY (nel modulo calendar):            calendar — General calendar-related functions.
                                                             (line  490)
* JUMP (monitoring event):               Events.             (line   43)
* JUMP (opcode):                         Python Bytecode Instructions.
                                                             (line 1491)
* jump (pdb command):                    Debugger commands.  (line  241)
* JUMP_BACKWARD (opcode):                Python Bytecode Instructions.
                                                             (line  860)
* JUMP_BACKWARD_NO_INTERRUPT (opcode):   Python Bytecode Instructions.
                                                             (line  866)
* JUMP_FORWARD (opcode):                 Python Bytecode Instructions.
                                                             (line  856)
* JUMP_IF_FALSE (opcode):                Python Bytecode Instructions.
                                                             (line 1497)
* JUMP_IF_TRUE (opcode):                 Python Bytecode Instructions.
                                                             (line 1497)
* JUMP_NO_INTERRUPT (opcode):            Python Bytecode Instructions.
                                                             (line 1491)
* JUNE (nel modulo calendar):            calendar — General calendar-related functions.
                                                             (line  490)
* kbhit() (nel modulo msvcrt):           Console I/O.        (line    6)
* kde_random() (nel modulo statistics):  Function details.   (line  185)
* kde() (nel modulo statistics):         Function details.   (line  137)
* KEEP (enum.FlagBoundary attributo):    Data Types<2>.      (line  722)
* kevent() (nel modulo select):          select — Waiting for I/O completion.
                                                             (line  110)
* key:                                   Dictionary displays.
                                                             (line    6)
* key (http.cookies.Morsel attributo):   Morsel Objects.     (line   71)
* key (zoneinfo.ZoneInfo attributo):     The ZoneInfo class. (line   78)
* key function:                          Glossary.           (line  969)
* KEY_A1 (nel modulo curses):            Constants<6>.       (line  234)
* KEY_A3 (nel modulo curses):            Constants<6>.       (line  237)
* KEY_ALL_ACCESS (nel modulo winreg):    Access Rights.      (line    8)
* KEY_B2 (nel modulo curses):            Constants<6>.       (line  240)
* KEY_BACKSPACE (nel modulo curses):     Constants<6>.       (line  164)
* KEY_BEG (nel modulo curses):           Constants<6>.       (line  252)
* KEY_BREAK (nel modulo curses):         Constants<6>.       (line  146)
* KEY_BTAB (nel modulo curses):          Constants<6>.       (line  249)
* KEY_C1 (nel modulo curses):            Constants<6>.       (line  243)
* KEY_C3 (nel modulo curses):            Constants<6>.       (line  246)
* KEY_CANCEL (nel modulo curses):        Constants<6>.       (line  255)
* KEY_CATAB (nel modulo curses):         Constants<6>.       (line  216)
* KEY_CLEAR (nel modulo curses):         Constants<6>.       (line  189)
* KEY_CLOSE (nel modulo curses):         Constants<6>.       (line  258)
* KEY_COMMAND (nel modulo curses):       Constants<6>.       (line  261)
* KEY_COPY (nel modulo curses):          Constants<6>.       (line  264)
* KEY_CREATE (nel modulo curses):        Constants<6>.       (line  267)
* KEY_CREATE_LINK (nel modulo winreg):   Access Rights.      (line   51)
* KEY_CREATE_SUB_KEY (nel modulo winreg): Access Rights.     (line   38)
* KEY_CTAB (nel modulo curses):          Constants<6>.       (line  213)
* KEY_DC (nel modulo curses):            Constants<6>.       (line  180)
* KEY_DL (nel modulo curses):            Constants<6>.       (line  174)
* KEY_DOWN (nel modulo curses):          Constants<6>.       (line  149)
* KEY_EIC (nel modulo curses):           Constants<6>.       (line  186)
* KEY_END (nel modulo curses):           Constants<6>.       (line  270)
* KEY_ENTER (nel modulo curses):         Constants<6>.       (line  219)
* KEY_ENUMERATE_SUB_KEYS (nel modulo winreg): Access Rights. (line   42)
* KEY_EOL (nel modulo curses):           Constants<6>.       (line  195)
* KEY_EOS (nel modulo curses):           Constants<6>.       (line  192)
* KEY_EXECUTE (nel modulo winreg):       Access Rights.      (line   26)
* KEY_EXIT (nel modulo curses):          Constants<6>.       (line  273)
* KEY_F0 (nel modulo curses):            Constants<6>.       (line  167)
* KEY_FIND (nel modulo curses):          Constants<6>.       (line  276)
* KEY_Fn (nel modulo curses):            Constants<6>.       (line  171)
* KEY_HELP (nel modulo curses):          Constants<6>.       (line  279)
* KEY_HOME (nel modulo curses):          Constants<6>.       (line  161)
* KEY_IC (nel modulo curses):            Constants<6>.       (line  183)
* KEY_IL (nel modulo curses):            Constants<6>.       (line  177)
* KEY_LEFT (nel modulo curses):          Constants<6>.       (line  155)
* KEY_LL (nel modulo curses):            Constants<6>.       (line  231)
* KEY_MARK (nel modulo curses):          Constants<6>.       (line  282)
* KEY_MAX (nel modulo curses):           Constants<6>.       (line  423)
* KEY_MESSAGE (nel modulo curses):       Constants<6>.       (line  285)
* KEY_MIN (nel modulo curses):           Constants<6>.       (line  143)
* KEY_MOUSE (nel modulo curses):         Constants<6>.       (line  417)
* KEY_MOVE (nel modulo curses):          Constants<6>.       (line  288)
* KEY_NEXT (nel modulo curses):          Constants<6>.       (line  291)
* KEY_NOTIFY (nel modulo winreg):        Access Rights.      (line   46)
* KEY_NPAGE (nel modulo curses):         Constants<6>.       (line  204)
* KEY_OPEN (nel modulo curses):          Constants<6>.       (line  294)
* KEY_OPTIONS (nel modulo curses):       Constants<6>.       (line  297)
* KEY_PPAGE (nel modulo curses):         Constants<6>.       (line  207)
* KEY_PREVIOUS (nel modulo curses):      Constants<6>.       (line  300)
* KEY_PRINT (nel modulo curses):         Constants<6>.       (line  228)
* KEY_QUERY_VALUE (nel modulo winreg):   Access Rights.      (line   30)
* KEY_READ (nel modulo winreg):          Access Rights.      (line   20)
* KEY_REDO (nel modulo curses):          Constants<6>.       (line  303)
* KEY_REFERENCE (nel modulo curses):     Constants<6>.       (line  306)
* KEY_REFRESH (nel modulo curses):       Constants<6>.       (line  309)
* KEY_REPLACE (nel modulo curses):       Constants<6>.       (line  312)
* KEY_RESET (nel modulo curses):         Constants<6>.       (line  225)
* KEY_RESIZE (nel modulo curses):        Constants<6>.       (line  420)
* KEY_RESTART (nel modulo curses):       Constants<6>.       (line  315)
* KEY_RESUME (nel modulo curses):        Constants<6>.       (line  318)
* KEY_RIGHT (nel modulo curses):         Constants<6>.       (line  158)
* KEY_SAVE (nel modulo curses):          Constants<6>.       (line  321)
* KEY_SBEG (nel modulo curses):          Constants<6>.       (line  324)
* KEY_SCANCEL (nel modulo curses):       Constants<6>.       (line  327)
* KEY_SCOMMAND (nel modulo curses):      Constants<6>.       (line  330)
* KEY_SCOPY (nel modulo curses):         Constants<6>.       (line  333)
* KEY_SCREATE (nel modulo curses):       Constants<6>.       (line  336)
* KEY_SDC (nel modulo curses):           Constants<6>.       (line  339)
* KEY_SDL (nel modulo curses):           Constants<6>.       (line  342)
* KEY_SELECT (nel modulo curses):        Constants<6>.       (line  345)
* KEY_SEND (nel modulo curses):          Constants<6>.       (line  348)
* KEY_SEOL (nel modulo curses):          Constants<6>.       (line  351)
* KEY_SET_VALUE (nel modulo winreg):     Access Rights.      (line   34)
* KEY_SEXIT (nel modulo curses):         Constants<6>.       (line  354)
* KEY_SF (nel modulo curses):            Constants<6>.       (line  198)
* KEY_SFIND (nel modulo curses):         Constants<6>.       (line  357)
* KEY_SHELP (nel modulo curses):         Constants<6>.       (line  360)
* KEY_SHOME (nel modulo curses):         Constants<6>.       (line  363)
* KEY_SIC (nel modulo curses):           Constants<6>.       (line  366)
* KEY_SLEFT (nel modulo curses):         Constants<6>.       (line  369)
* KEY_SMESSAGE (nel modulo curses):      Constants<6>.       (line  372)
* KEY_SMOVE (nel modulo curses):         Constants<6>.       (line  375)
* KEY_SNEXT (nel modulo curses):         Constants<6>.       (line  378)
* KEY_SOPTIONS (nel modulo curses):      Constants<6>.       (line  381)
* KEY_SPREVIOUS (nel modulo curses):     Constants<6>.       (line  384)
* KEY_SPRINT (nel modulo curses):        Constants<6>.       (line  387)
* KEY_SR (nel modulo curses):            Constants<6>.       (line  201)
* KEY_SREDO (nel modulo curses):         Constants<6>.       (line  390)
* KEY_SREPLACE (nel modulo curses):      Constants<6>.       (line  393)
* KEY_SRESET (nel modulo curses):        Constants<6>.       (line  222)
* KEY_SRIGHT (nel modulo curses):        Constants<6>.       (line  396)
* KEY_SRSUME (nel modulo curses):        Constants<6>.       (line  399)
* KEY_SSAVE (nel modulo curses):         Constants<6>.       (line  402)
* KEY_SSUSPEND (nel modulo curses):      Constants<6>.       (line  405)
* KEY_STAB (nel modulo curses):          Constants<6>.       (line  210)
* KEY_SUNDO (nel modulo curses):         Constants<6>.       (line  408)
* KEY_SUSPEND (nel modulo curses):       Constants<6>.       (line  411)
* KEY_UNDO (nel modulo curses):          Constants<6>.       (line  414)
* KEY_UP (nel modulo curses):            Constants<6>.       (line  152)
* KEY_WOW64_32KEY (nel modulo winreg):   64-bit Specific.    (line   14)
* KEY_WOW64_64KEY (nel modulo winreg):   64-bit Specific.    (line    8)
* KEY_WRITE (nel modulo winreg):         Access Rights.      (line   15)
* key/value pair:                        Dictionary displays.
                                                             (line    6)
* KeyboardInterrupt:                     Concrete exceptions.
                                                             (line   91)
* KeyboardInterrupt (built-in exception): Signal Handling<2>.
                                                             (line    7)
* KeyboardInterrupt (built-in exception) <1>: Signal Handling<2>.
                                                             (line   34)
* KeyboardInterrupt (built-in exception) <2>: Signal Handling<2>.
                                                             (line   44)
* KeyError:                              Concrete exceptions.
                                                             (line   86)
* keylog_filename (ssl.SSLContext attributo): SSL Contexts.  (line  528)
* keyname() (nel modulo curses):         Functions<5>.       (line  279)
* keypad() (curses.window metodo):       Window Objects.     (line  389)
* keyrefs() (weakref.WeakKeyDictionary metodo): weakref — Weak references.
                                                             (line  210)
* keys() (contextvars.Context metodo):   Manual Context Management.
                                                             (line  133)
* keys() (dict metodo):                  Tipi di Mapping — dict.
                                                             (line  199)
* keys() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  232)
* keys() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  344)
* keys() (mailbox.Mailbox metodo):       Mailbox objects.    (line  112)
* keys() (sqlite3.Row metodo):           Row objects.        (line   19)
* keys() (types.MappingProxyType metodo): Standard Interpreter Types.
                                                             (line  276)
* keys() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line   76)
* KeysView (classe in collections.abc):  Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  125)
* KeysView (classe in typing):           Aliases to container ABCs in collections abc.
                                                             (line   64)
* keyword:                               Keywords.           (line    6)
* keyword <1>:                           Soft Keywords.      (line    6)
* keyword (classe in ast):               Expressions<2>.     (line  151)
* keyword argument:                      Glossary.           (line  992)
* keyword;as:                            The import statement.
                                                             (line    6)
* keyword;as <1>:                        The try statement.  (line    6)
* keyword;as <2>:                        The with statement. (line    6)
* keyword;as <3>:                        The match statement.
                                                             (line    6)
* keyword;async:                         Coroutine function definition.
                                                             (line    9)
* keyword;await:                         Calls.              (line  161)
* keyword;await <1>:                     Coroutine function definition.
                                                             (line    9)
* keyword;case:                          The match statement.
                                                             (line    6)
* keyword;elif:                          The if statement.   (line    6)
* keyword;else:                          The break statement.
                                                             (line   12)
* keyword;else <1>:                      The if statement.   (line    6)
* keyword;else <2>:                      The while statement.
                                                             (line    6)
* keyword;else <3>:                      The for statement.  (line    6)
* keyword;else <4>:                      The try statement.  (line    6)
* keyword;else <5>:                      except* clause.     (line   66)
* keyword;except:                        The try statement.  (line    6)
* keyword;except_star:                   except clause.      (line   83)
* keyword;finally:                       The return statement.
                                                             (line   17)
* keyword;finally <1>:                   The break statement.
                                                             (line   18)
* keyword;finally <2>:                   The continue statement.
                                                             (line    6)
* keyword;finally <3>:                   The try statement.  (line    6)
* keyword;finally <4>:                   else clause.        (line   11)
* keyword;from:                          Yield expressions.  (line    6)
* keyword;from <1>:                      The import statement.
                                                             (line    6)
* keyword;if:                            The match statement.
                                                             (line    6)
* keyword;in:                            The for statement.  (line    6)
* keyword;yield:                         Yield expressions.  (line    6)
* keywords (functools.partial attributo): partial Objects.   (line   20)
* kill_python() (nel modulo test.support.script_helper): test support script_helper — Utilities for the Python execution tests.
                                                             (line   77)
* kill_workers() (concurrent.futures.ProcessPoolExecutor metodo): ProcessPoolExecutor.
                                                             (line  111)
* kill() (asyncio.subprocess.Process metodo): Interacting with Subprocesses.
                                                             (line  106)
* kill() (asyncio.SubprocessTransport metodo): Subprocess Transports.
                                                             (line   35)
* kill() (multiprocessing.Process metodo): Process and exceptions.
                                                             (line  243)
* kill() (nel modulo os):                Process Management. (line  327)
* kill() (subprocess.Popen metodo):      Popen Objects.      (line  100)
* killchar() (nel modulo curses):        Functions<5>.       (line  289)
* killpg() (nel modulo os):              Process Management. (line  349)
* kind (inspect.Parameter attributo):    Introspecting callables with the Signature object.
                                                             (line  248)
* knownfiles (nel modulo mimetypes):     mimetypes — Map filenames to MIME types.
                                                             (line  139)
* kqueue() (nel modulo select):          select — Waiting for I/O completion.
                                                             (line   99)
* KqueueSelector (classe in selectors):  Classes<3>.         (line  195)
* KW_ONLY (nel modulo dataclasses):      Module contents<4>. (line  493)
* kwargs (inspect.BoundArguments attributo): Introspecting callables with the Signature object.
                                                             (line  377)
* kwargs (typing.ParamSpec attributo):   Building generic types and type aliases.
                                                             (line  458)
* kwlist (nel modulo keyword):           keyword — Testing for Python keywords.
                                                             (line   17)
* L (nel modulo re):                     Flags.              (line   58)
* L2CAP_LM (nel modulo socket):          Constants<8>.       (line  346)
* lambda:                                Glossary.           (line  995)
* Lambda (classe in ast):                Function and class definitions.
                                                             (line   32)
* lambda;expression:                     Lambdas.            (line    6)
* lambda;expression <1>:                 Function definitions.
                                                             (line  124)
* lambda;form:                           Lambdas.            (line    6)
* LambdaType (nel modulo types):         Standard Interpreter Types.
                                                             (line   25)
* LANG:                                  GNU gettext API.    (line   21)
* LANG <1>:                              Class-based API.    (line   26)
* LANG <2>:                              locale — Internationalization services.
                                                             (line   63)
* LANG <3>:                              locale — Internationalization services.
                                                             (line  368)
* LANG <4>:                              locale — Internationalization services.
                                                             (line  372)
* LANGUAGE:                              GNU gettext API.    (line   20)
* LANGUAGE <1>:                          Class-based API.    (line   25)
* large files:                           Large File Support. (line    6)
* LARGEST (nel modulo test.support):     test support — Utilities for the Python test suite.
                                                             (line  202)
* LargeZipFile:                          zipfile — Work with ZIP archives.
                                                             (line   43)
* last_accepted (multiprocessing.connection.Listener attributo): Listeners and Clients.
                                                             (line  103)
* last_exc (nel modulo sys):             sys — System-specific parameters and functions.
                                                             (line 1329)
* last_mode (compression.zstd.ZstdCompressor attributo): Compressing and decompressing data in memory.
                                                             (line  151)
* last_traceback (in module sys):        Traceback objects.  (line    6)
* last_traceback (nel modulo sys):       sys — System-specific parameters and functions.
                                                             (line 1368)
* last_type (nel modulo sys):            sys — System-specific parameters and functions.
                                                             (line 1368)
* last_value (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line 1368)
* lastChild (xml.dom.Node attributo):    Node Objects.       (line   59)
* lastcmd (cmd.Cmd attributo):           Cmd Objects.        (line  139)
* lastgroup (re.Match attributo):        Match Objects.      (line  201)
* lastindex (re.Match attributo):        Match Objects.      (line  193)
* lastResort (nel modulo logging):       Module-Level Attributes.
                                                             (line    6)
* lastrowid (sqlite3.Cursor attributo):  Cursor objects.     (line  206)
* layout() (tkinter.ttk.Style metodo):   Ttk Styling.        (line   96)
* lazy (compression.zstd.Strategy attributo): Advanced parameter control.
                                                             (line  315)
* lazy2 (compression.zstd.Strategy attributo): Advanced parameter control.
                                                             (line  317)
* lazycache() (nel modulo linecache):    linecache — Random access to text lines.
                                                             (line   56)
* LazyLoader (classe in importlib.util): importlib util – Utility code for importers.
                                                             (line  192)
* LBRACE (nel modulo token):             token — Constants used with Python parse trees.
                                                             (line  266)
* LBYL:                                  Glossary.           (line 1002)
* LC_ALL:                                GNU gettext API.    (line   20)
* LC_ALL <1>:                            Class-based API.    (line   25)
* LC_ALL (nel modulo locale):            locale — Internationalization services.
                                                             (line  584)
* LC_COLLATE (nel modulo locale):        locale — Internationalization services.
                                                             (line  550)
* LC_CTYPE (nel modulo locale):          locale — Internationalization services.
                                                             (line  536)
* LC_MESSAGES:                           GNU gettext API.    (line   20)
* LC_MESSAGES <1>:                       Class-based API.    (line   26)
* LC_MESSAGES (nel modulo locale):       locale — Internationalization services.
                                                             (line  566)
* LC_MONETARY (nel modulo locale):       locale — Internationalization services.
                                                             (line  561)
* LC_NUMERIC (nel modulo locale):        locale — Internationalization services.
                                                             (line  576)
* LC_TIME (nel modulo locale):           locale — Internationalization services.
                                                             (line  556)
* lchflags() (nel modulo os):            Files and Directories.
                                                             (line  307)
* lchmod() (nel modulo os):              Files and Directories.
                                                             (line  321)
* lchmod() (pathlib.Path metodo):        Permissions and ownership.
                                                             (line   57)
* lchown() (nel modulo os):              Files and Directories.
                                                             (line  342)
* lcm() (nel modulo math):               Number-theoretic functions.
                                                             (line   56)
* ldexp() (nel modulo math):             Floating point manipulation functions.
                                                             (line   77)
* LDFLAGS:                               New Improved and Deprecated Modules<4>.
                                                             (line   59)
* LDFLAGS <1>:                           Preprocessor flags. (line   18)
* LDFLAGS <2>:                           Linker flags.       (line   15)
* LDFLAGS <3>:                           Linker flags.       (line   18)
* LDFLAGS <4>:                           Linker flags.       (line   28)
* LDFLAGS <5>:                           Linker flags.       (line   31)
* LDFLAGS <6>:                           Linker flags.       (line   35)
* LDFLAGS <7>:                           Linker flags.       (line   50)
* LDFLAGS_NODIST:                        Linker flags.       (line   26)
* LDFLAGS_NODIST <1>:                    Linker flags.       (line   40)
* ldm_bucket_size_log (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  162)
* ldm_hash_log (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  147)
* ldm_hash_rate_log (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  170)
* ldm_min_match (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  155)
* le() (nel modulo operator):            operator — Standard operators as functions.
                                                             (line   24)
* leading whitespace:                    Indentation.        (line    6)
* leapdays() (nel modulo calendar):      calendar — General calendar-related functions.
                                                             (line  369)
* leaveok() (curses.window metodo):      Window Objects.     (line  396)
* left (filecmp.dircmp attributo):       The dircmp class.   (line   45)
* left_list (filecmp.dircmp attributo):  The dircmp class.   (line   53)
* left_only (filecmp.dircmp attributo):  The dircmp class.   (line   67)
* left() (nel modulo turtle):            Turtle motion.      (line   57)
* LEFTSHIFT (nel modulo token):          token — Constants used with Python parse trees.
                                                             (line  290)
* LEFTSHIFTEQUAL (nel modulo token):     token — Constants used with Python parse trees.
                                                             (line  323)
* LEGACY_TRANSACTION_CONTROL (nel modulo sqlite3): Module constants.
                                                             (line    6)
* lenfunc (C type):                      Slot Type typedefs. (line   94)
* length (xml.dom.NamedNodeMap attributo): NamedNodeMap Objects.
                                                             (line    8)
* length (xml.dom.NodeList attributo):   NodeList Objects.   (line   21)
* length_hint() (nel modulo operator):   operator — Standard operators as functions.
                                                             (line  222)
* LESS (nel modulo token):               token — Constants used with Python parse trees.
                                                             (line  251)
* LESSEQUAL (nel modulo token):          token — Constants used with Python parse trees.
                                                             (line  278)
* level (logging.Logger attributo):      Logger Objects.     (line   33)
* lexical analysis:                      Lexical analysis.   (line    6)
* lexical analyzer:                      Glossary.           (line 1017)
* lexical definitions:                   Notation.           (line  107)
* LexicalHandler (classe in xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line   45)
* lexists() (nel modulo os.path):        os path — Common pathname manipulations.
                                                             (line  128)
* LF (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line   52)
* lgamma() (nel modulo math):            Special functions.  (line   35)
* libc_ver() (nel modulo platform):      Unix platforms.     (line    6)
* LIBRARIES_ASSEMBLY_NAME_PREFIX (nel modulo msvcrt): Other Functions.
                                                             (line   98)
* library (nel modulo dbm.ndbm):         dbm ndbm — New Database Manager.
                                                             (line   34)
* library (ssl.SSLError attributo):      Exceptions<18>.     (line   19)
* LibraryLoader (classe in ctypes):      Loading shared libraries.
                                                             (line  170)
* license (variabile built-in):          Constants added by the site module.
                                                             (line   32)
* LifoQueue (classe in asyncio):         LIFO Queue.         (line    6)
* LifoQueue (classe in queue):           queue — A synchronized queue class.
                                                             (line   42)
* light-weight processes:                _thread — Low-level threading API.
                                                             (line    6)
* limit_denominator() (fractions.Fraction metodo): fractions — Rational numbers.
                                                             (line  169)
* LimitOverrunError:                     Exceptions<15>.     (line   61)
* line (bdb.Breakpoint attributo):       bdb — Debugger framework.
                                                             (line   86)
* LINE (monitoring event):               Events.             (line   47)
* line (traceback.FrameSummary attributo): FrameSummary Objects.
                                                             (line   43)
* line continuation:                     Explicit line joining.
                                                             (line    6)
* line joining:                          Logical lines.      (line    6)
* line joining <1>:                      Explicit line joining.
                                                             (line    6)
* line structure:                        Line structure.     (line    6)
* line_buffering (io.TextIOWrapper attributo): Text I/O<2>.  (line  175)
* line_num (csv.csvreader attributo):    Reader Objects.     (line   23)
* linear_regression() (nel modulo statistics): Function details.
                                                             (line  628)
* lineno (ast.AST attributo):            Node classes.       (line   50)
* lineno (doctest.DocTest attributo):    DocTest Objects.    (line   42)
* lineno (doctest.Example attributo):    Example Objects.    (line   41)
* lineno (inspect.FrameInfo attributo):  The interpreter stack.
                                                             (line   22)
* lineno (inspect.Traceback attributo):  The interpreter stack.
                                                             (line   63)
* lineno (json.JSONDecodeError attributo): Exceptions<19>.   (line   23)
* lineno (netrc.NetrcParseError attributo): netrc — netrc file processing.
                                                             (line   61)
* lineno (pyclbr.Class attributo):       Class Objects.      (line   24)
* lineno (pyclbr.Function attributo):    Function Objects.   (line   23)
* lineno (re.PatternError attributo):    Exceptions<2>.      (line   28)
* lineno (shlex.shlex attributo):        shlex Objects.      (line  169)
* lineno (SyntaxError attributo):        Concrete exceptions.
                                                             (line  328)
* lineno (tomllib.TOMLDecodeError attributo): tomllib — Parse TOML files.
                                                             (line   77)
* lineno (traceback.FrameSummary attributo): FrameSummary Objects.
                                                             (line   34)
* lineno (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line   95)
* lineno (tracemalloc.Filter attributo): Filter.             (line   50)
* lineno (tracemalloc.Frame attributo):  Frame.              (line   17)
* lineno (xml.parsers.expat.ExpatError attributo): ExpatError Exceptions.
                                                             (line   27)
* lineno() (nel modulo fileinput):       fileinput — Iterate over lines from multiple input streams.
                                                             (line   97)
* LINES:                                 Functions<5>.       (line  140)
* LINES <1>:                             Functions<5>.       (line  611)
* LINES <2>:                             Functions<5>.       (line  613)
* LINES (nel modulo curses):             Constants<6>.       (line   51)
* lines (os.terminal_size attributo):    Querying the size of a terminal.
                                                             (line   34)
* linesep (email.policy.Policy attributo): email policy Policy Objects.
                                                             (line  153)
* linesep (nel modulo os):               Miscellaneous System Information.
                                                             (line  150)
* lineterminator (csv.Dialect attributo): Dialects and Formatting Parameters.
                                                             (line   55)
* LineTooLong:                           http client — HTTP protocol client.
                                                             (line  183)
* link() (nel modulo os):                Files and Directories.
                                                             (line  356)
* linked_to_musl() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  597)
* LinkFallbackError:                     tarfile — Read and write tar archive files.
                                                             (line  308)
* linkname (tarfile.TarInfo attributo):  TarInfo Objects.    (line   95)
* LinkOutsideDestinationError:           tarfile — Read and write tar archive files.
                                                             (line  303)
* list:                                  Glossary.           (line 1021)
* list (classe built-in):                Liste<2>.           (line   10)
* List (classe in ast):                  Literals<3>.        (line  129)
* List (classe in typing):               Aliases to built-in types.
                                                             (line   18)
* list (pdb command):                    Debugger commands.  (line  251)
* list comprehension:                    Glossary.           (line 1027)
* list_all() (nel modulo concurrent.interpreters): Reference<4>.
                                                             (line    8)
* LIST_APPEND (opcode):                  Python Bytecode Instructions.
                                                             (line  381)
* list_dialects() (nel modulo csv):      Module Contents<3>. (line   92)
* LIST_EXTEND (opcode):                  Python Bytecode Instructions.
                                                             (line  732)
* list_folders() (mailbox.Maildir metodo): Maildir objects.  (line   65)
* list_folders() (mailbox.MH metodo):    MH objects.         (line   35)
* list;comprehensions:                   List displays.      (line    6)
* list;display:                          List displays.      (line    6)
* list() (imaplib.IMAP4 metodo):         IMAP4 Objects.      (line  205)
* list() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  233)
* list() (poplib.POP3 metodo):           POP3 Objects.       (line   57)
* list() (tarfile.TarFile metodo):       TarFile Objects.    (line  122)
* ListComp (classe in ast):              Comprehensions.     (line    6)
* listdir() (nel modulo os):             Files and Directories.
                                                             (line  379)
* listdrives() (nel modulo os):          Files and Directories.
                                                             (line  416)
* listen() (nel modulo logging.config):  Configuration functions.
                                                             (line  118)
* listen() (nel modulo turtle):          Using screen events.
                                                             (line    6)
* listen() (socket.socket metodo):       Socket Objects.     (line  197)
* Listener (classe in multiprocessing.connection): Listeners and Clients.
                                                             (line   50)
* listener (logging.handlers.QueueHandler attributo): QueueHandler.
                                                             (line   92)
* listMethods() (xmlrpc.client.ServerProxy.system metodo): ServerProxy Objects.
                                                             (line   17)
* listmounts() (nel modulo os):          Files and Directories.
                                                             (line  435)
* listvolumes() (nel modulo os):         Files and Directories.
                                                             (line  459)
* listxattr() (nel modulo os):           Linux extended attributes.
                                                             (line   26)
* literal:                               Literals.           (line    6)
* literal <1>:                           Literals<2>.        (line    6)
* Literal (nel modulo typing):           Special forms.      (line  139)
* literal_eval() (nel modulo ast):       ast helpers.        (line   84)
* LiteralString (nel modulo typing):     Special types.      (line   67)
* LittleEndianStructure (classe in ctypes): Structured data types.
                                                             (line   29)
* LittleEndianUnion (classe in ctypes):  Structured data types.
                                                             (line   19)
* ljust() (bytearray metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  314)
* ljust() (bytes metodo):                Operazioni su Bytes e Bytearray.
                                                             (line  314)
* ljust() (str metodo):                  Metodi per le Stringhe.
                                                             (line  454)
* LK_LOCK (nel modulo msvcrt):           File Operations.    (line   19)
* LK_NBLCK (nel modulo msvcrt):          File Operations.    (line   27)
* LK_NBRLCK (nel modulo msvcrt):         File Operations.    (line   27)
* LK_RLCK (nel modulo msvcrt):           File Operations.    (line   19)
* LK_UNLCK (nel modulo msvcrt):          File Operations.    (line   33)
* ll (pdb command):                      Debugger commands.  (line  267)
* LMTP (classe in smtplib):              smtplib — SMTP protocol client.
                                                             (line  106)
* ln() (decimal.Context metodo):         Context objects.    (line  376)
* ln() (decimal.Decimal metodo):         Decimal objects.    (line  349)
* LNKTYPE (nel modulo tarfile):          tarfile — Read and write tar archive files.
                                                             (line  329)
* Load (classe in ast):                  Variables.          (line   11)
* LOAD_ATTR (opcode):                    Python Bytecode Instructions.
                                                             (line  772)
* LOAD_BUILD_CLASS (opcode):             Python Bytecode Instructions.
                                                             (line  504)
* load_cert_chain() (ssl.SSLContext metodo): SSL Contexts.   (line  101)
* LOAD_CLOSURE (opcode):                 Python Bytecode Instructions.
                                                             (line 1503)
* LOAD_COMMON_CONSTANT (opcode):         Python Bytecode Instructions.
                                                             (line  495)
* LOAD_CONST (opcode):                   Python Bytecode Instructions.
                                                             (line  619)
* LOAD_CONST_IMMORTAL (opcode):          Python Bytecode Instructions.
                                                             (line 1486)
* load_default_certs() (ssl.SSLContext metodo): SSL Contexts.
                                                             (line  132)
* LOAD_DEREF (opcode):                   Python Bytecode Instructions.
                                                             (line 1018)
* load_dh_params() (ssl.SSLContext metodo): SSL Contexts.    (line  353)
* load_extension() (sqlite3.Connection metodo): Connection objects.
                                                             (line  474)
* LOAD_FAST (opcode):                    Python Bytecode Instructions.
                                                             (line  942)
* LOAD_FAST_AND_CLEAR (opcode):          Python Bytecode Instructions.
                                                             (line  980)
* LOAD_FAST_BORROW (opcode):             Python Bytecode Instructions.
                                                             (line  951)
* LOAD_FAST_BORROW_LOAD_FAST_BORROW (opcode): Python Bytecode Instructions.
                                                             (line  965)
* LOAD_FAST_CHECK (opcode):              Python Bytecode Instructions.
                                                             (line  972)
* LOAD_FAST_LOAD_FAST (opcode):          Python Bytecode Instructions.
                                                             (line  958)
* LOAD_FROM_DICT_OR_DEREF (opcode):      Python Bytecode Instructions.
                                                             (line 1026)
* LOAD_FROM_DICT_OR_GLOBALS (opcode):    Python Bytecode Instructions.
                                                             (line  644)
* LOAD_GLOBAL (opcode):                  Python Bytecode Instructions.
                                                             (line  935)
* LOAD_LOCALS (opcode):                  Python Bytecode Instructions.
                                                             (line  635)
* load_module() (importlib.abc.FileLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  315)
* load_module() (importlib.abc.InspectLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  268)
* load_module() (importlib.abc.Loader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  127)
* load_module() (importlib.abc.SourceLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  415)
* load_module() (importlib.machinery.SourceFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  236)
* load_module() (importlib.machinery.SourcelessFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  280)
* load_module() (zipimport.zipimporter metodo): zipimporter Objects.
                                                             (line   79)
* LOAD_NAME (opcode):                    Python Bytecode Instructions.
                                                             (line  629)
* load_package_tests() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  659)
* LOAD_SMALL_INT (opcode):               Python Bytecode Instructions.
                                                             (line  623)
* LOAD_SPECIAL (opcode):                 Python Bytecode Instructions.
                                                             (line 1440)
* LOAD_SUPER_ATTR (opcode):              Python Bytecode Instructions.
                                                             (line  790)
* load_verify_locations() (ssl.SSLContext metodo): SSL Contexts.
                                                             (line  149)
* load() (http.cookiejar.FileCookieJar metodo): CookieJar and FileCookieJar Objects.
                                                             (line  126)
* load() (http.cookies.BaseCookie metodo): Cookie Objects.   (line   40)
* load() (nel modulo json):              Basic Usage.        (line  109)
* load() (nel modulo marshal):           marshal — Internal Python object serialization.
                                                             (line   92)
* load() (nel modulo pickle):            Module Interface.   (line   64)
* load() (nel modulo plistlib):          plistlib — Generate and parse Apple plist files.
                                                             (line   46)
* load() (nel modulo tomllib):           tomllib — Parse TOML files.
                                                             (line   32)
* load() (pickle.Unpickler metodo):      Module Interface.   (line  287)
* load() (tracemalloc.Snapshot metodo della classe): Snapshot.
                                                             (line   50)
* loader:                                Finders and loaders.
                                                             (line    6)
* loader <1>:                            Glossary.           (line 1051)
* Loader (classe in importlib.abc):      importlib abc – Abstract base classes related to import.
                                                             (line   91)
* loader (importlib.machinery.ModuleSpec attributo): importlib machinery – Importers and path hooks.
                                                             (line  388)
* loader_state (importlib.machinery.ModuleSpec attributo): importlib machinery – Importers and path hooks.
                                                             (line  417)
* LoadError:                             http cookiejar — Cookie handling for HTTP clients.
                                                             (line   34)
* LoadFileDialog (classe in tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line  135)
* LoadKey() (nel modulo winreg):         Functions<13>.      (line  258)
* LoadLibrary() (ctypes.LibraryLoader metodo): Loading shared libraries.
                                                             (line  181)
* loads() (nel modulo json):             Basic Usage.        (line  190)
* loads() (nel modulo marshal):          marshal — Internal Python object serialization.
                                                             (line  131)
* loads() (nel modulo pickle):           Module Interface.   (line   82)
* loads() (nel modulo plistlib):         plistlib — Generate and parse Apple plist files.
                                                             (line   82)
* loads() (nel modulo tomllib):          tomllib — Parse TOML files.
                                                             (line   48)
* loads() (nel modulo xmlrpc.client):    Convenience Functions.
                                                             (line   19)
* loadTestsFromModule() (unittest.TestLoader metodo): Loading and running tests.
                                                             (line   41)
* loadTestsFromName() (unittest.TestLoader metodo): Loading and running tests.
                                                             (line   70)
* loadTestsFromNames() (unittest.TestLoader metodo): Loading and running tests.
                                                             (line  104)
* loadTestsFromTestCase() (unittest.TestLoader metodo): Loading and running tests.
                                                             (line   29)
* local (classe in threading):           Thread-local data.  (line  127)
* LOCAL_CREDS (nel modulo socket):       Constants<8>.       (line  413)
* LOCAL_CREDS_PERSISTENT (nel modulo socket): Constants<8>.  (line  413)
* localcontext() (nel modulo decimal):   Context objects.    (line   25)
* LOCALE (nel modulo re):                Flags.              (line   58)
* locale encoding:                       Glossary.           (line 1065)
* localeconv() (nel modulo locale):      locale — Internationalization services.
                                                             (line   67)
* LocaleHTMLCalendar (classe in calendar): calendar — General calendar-related functions.
                                                             (line  336)
* LocaleTextCalendar (classe in calendar): calendar — General calendar-related functions.
                                                             (line  330)
* localize() (nel modulo locale):        locale — Internationalization services.
                                                             (line  518)
* localName (xml.dom.Attr attributo):    Attr Objects.       (line   13)
* localName (xml.dom.Node attributo):    Node Objects.       (line   64)
* localtime() (nel modulo email.utils):  email utils Miscellaneous utilities.
                                                             (line   13)
* localtime() (nel modulo time):         Functions<4>.       (line  149)
* Locator (classe in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers.
                                                             (line   43)
* lock:                                  Glossary.           (line 1036)
* Lock (classe in asyncio):              Lock.               (line    6)
* Lock (classe in multiprocessing):      Synchronization primitives.
                                                             (line   65)
* Lock (classe in threading):            Lock objects.       (line   33)
* lock (sys.thread_info attributo):      sys — System-specific parameters and functions.
                                                             (line 2113)
* LOCK_EX (nel modulo fcntl):            fcntl — The fcntl and ioctl system calls.
                                                             (line  199)
* LOCK_NB (nel modulo fcntl):            fcntl — The fcntl and ioctl system calls.
                                                             (line  203)
* LOCK_SH (nel modulo fcntl):            fcntl — The fcntl and ioctl system calls.
                                                             (line  195)
* LOCK_UN (nel modulo fcntl):            fcntl — The fcntl and ioctl system calls.
                                                             (line  191)
* lock, interpreter:                     Thread State and the Global Interpreter Lock.
                                                             (line    6)
* lock() (mailbox.Babyl metodo):         Babyl objects.      (line   60)
* lock() (mailbox.Mailbox metodo):       Mailbox objects.    (line  257)
* lock() (mailbox.Maildir metodo):       Maildir objects.    (line  209)
* lock() (mailbox.mbox metodo):          mbox objects.       (line   57)
* lock() (mailbox.MH metodo):            MH objects.         (line   87)
* lock() (mailbox.MMDF metodo):          MMDF objects.       (line   47)
* Lock() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  190)
* locked() (_thread.lock metodo):        _thread — Low-level threading API.
                                                             (line  178)
* locked() (asyncio.Condition metodo):   Condition.          (line   63)
* locked() (asyncio.Lock metodo):        Lock.               (line   58)
* locked() (asyncio.Semaphore metodo):   Semaphore.          (line   50)
* locked() (multiprocessing.BoundedSemaphore metodo): Synchronization primitives.
                                                             (line   34)
* locked() (multiprocessing.Lock metodo): Synchronization primitives.
                                                             (line  124)
* locked() (multiprocessing.RLock metodo): Synchronization primitives.
                                                             (line  199)
* locked() (multiprocessing.Semaphore metodo): Synchronization primitives.
                                                             (line  226)
* locked() (threading.Condition metodo): Condition objects.  (line   98)
* locked() (threading.Lock metodo):      Lock objects.       (line   90)
* locked() (threading.RLock metodo):     RLock objects.      (line  110)
* lockf() (nel modulo fcntl):            fcntl — The fcntl and ioctl system calls.
                                                             (line  184)
* lockf() (nel modulo os):               File Descriptor Operations.
                                                             (line  266)
* locking() (nel modulo msvcrt):         File Operations.    (line    6)
* LockType (nel modulo _thread):         _thread — Low-level threading API.
                                                             (line   28)
* LOG_ALERT (nel modulo syslog):         syslog — Unix syslog library routines.
                                                             (line  112)
* LOG_AUTH (nel modulo syslog):          syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_AUTHPRIV (nel modulo syslog):      syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_CONS (nel modulo syslog):          syslog — Unix syslog library routines.
                                                             (line  158)
* LOG_CRIT (nel modulo syslog):          syslog — Unix syslog library routines.
                                                             (line  112)
* LOG_CRON (nel modulo syslog):          syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_DAEMON (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  123)
* log_date_time_string() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  376)
* LOG_DEBUG (nel modulo syslog):         syslog — Unix syslog library routines.
                                                             (line  112)
* LOG_EMERG (nel modulo syslog):         syslog — Unix syslog library routines.
                                                             (line  112)
* LOG_ERR (nel modulo syslog):           syslog — Unix syslog library routines.
                                                             (line  112)
* log_error() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  345)
* log_exception() (wsgiref.handlers.BaseHandler metodo): wsgiref handlers – server/gateway base classes.
                                                             (line  213)
* LOG_FTP (nel modulo syslog):           syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_INFO (nel modulo syslog):          syslog — Unix syslog library routines.
                                                             (line  112)
* LOG_INSTALL (nel modulo syslog):       syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_KERN (nel modulo syslog):          syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_LAUNCHD (nel modulo syslog):       syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_LOCAL0 (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_LOCAL1 (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_LOCAL2 (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_LOCAL3 (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_LOCAL4 (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_LOCAL5 (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_LOCAL6 (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_LOCAL7 (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_LPR (nel modulo syslog):           syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_MAIL (nel modulo syslog):          syslog — Unix syslog library routines.
                                                             (line  123)
* log_message() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  351)
* LOG_NDELAY (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  158)
* LOG_NETINFO (nel modulo syslog):       syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_NEWS (nel modulo syslog):          syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_NOTICE (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  112)
* LOG_NOWAIT (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  158)
* LOG_ODELAY (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  158)
* LOG_PERROR (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  158)
* LOG_PID (nel modulo syslog):           syslog — Unix syslog library routines.
                                                             (line  158)
* LOG_RAS (nel modulo syslog):           syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_REMOTEAUTH (nel modulo syslog):    syslog — Unix syslog library routines.
                                                             (line  123)
* log_request() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  338)
* LOG_SYSLOG (nel modulo syslog):        syslog — Unix syslog library routines.
                                                             (line  123)
* log_to_stderr() (nel modulo multiprocessing): Logging<2>.  (line   24)
* LOG_USER (nel modulo syslog):          syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_UUCP (nel modulo syslog):          syslog — Unix syslog library routines.
                                                             (line  123)
* LOG_WARNING (nel modulo syslog):       syslog — Unix syslog library routines.
                                                             (line  112)
* log() (logging.Logger metodo):         Logger Objects.     (line  315)
* log() (nel modulo cmath):              Power and logarithmic functions.
                                                             (line   11)
* log() (nel modulo logging):            Module-Level Functions.
                                                             (line   99)
* log() (nel modulo math):               Power exponential and logarithmic functions.
                                                             (line   40)
* log10() (decimal.Context metodo):      Context objects.    (line  380)
* log10() (decimal.Decimal metodo):      Decimal objects.    (line  355)
* log10() (nel modulo cmath):            Power and logarithmic functions.
                                                             (line   17)
* log10() (nel modulo math):             Power exponential and logarithmic functions.
                                                             (line   67)
* log1p() (nel modulo math):             Power exponential and logarithmic functions.
                                                             (line   48)
* log2() (nel modulo math):              Power exponential and logarithmic functions.
                                                             (line   53)
* logb() (decimal.Context metodo):       Context objects.    (line  384)
* logb() (decimal.Decimal metodo):       Decimal objects.    (line  361)
* Logger (classe in logging):            Logger Objects.     (line   24)
* LoggerAdapter (classe in logging):     LoggerAdapter Objects.
                                                             (line   11)
* logical line:                          Logical lines.      (line    6)
* logical_and() (decimal.Context metodo): Context objects.   (line  388)
* logical_and() (decimal.Decimal metodo): Decimal objects.   (line  369)
* logical_invert() (decimal.Context metodo): Context objects.
                                                             (line  393)
* logical_invert() (decimal.Decimal metodo): Decimal objects.
                                                             (line  375)
* logical_or() (decimal.Context metodo): Context objects.    (line  397)
* logical_or() (decimal.Decimal metodo): Decimal objects.    (line  380)
* logical_xor() (decimal.Context metodo): Context objects.   (line  402)
* logical_xor() (decimal.Decimal metodo): Decimal objects.   (line  386)
* login_cram_md5() (imaplib.IMAP4 metodo): IMAP4 Objects.    (line  216)
* login_tty() (nel modulo os):           File Descriptor Operations.
                                                             (line  292)
* login() (ftplib.FTP metodo):           FTP objects.        (line  129)
* login() (imaplib.IMAP4 metodo):        IMAP4 Objects.      (line  211)
* login() (smtplib.SMTP metodo):         SMTP Objects.       (line  102)
* LOGNAME:                               Process Parameters. (line  262)
* LOGNAME <1>:                           getpass — Portable password input.
                                                             (line   59)
* lognormvariate() (nel modulo random):  Real-valued distributions.
                                                             (line   78)
* logout() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line  225)
* LogRecord (classe in logging):         LogRecord Objects.  (line   11)
* LONG_MAX (C macro):                    Integer Objects.    (line  167)
* LONG_TIMEOUT (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  110)
* longMessage (unittest.TestCase attributo): Test cases.     (line  766)
* longname() (nel modulo curses):        Functions<5>.       (line  296)
* lookup_error() (nel modulo codecs):    Error Handlers.     (line  130)
* lookup() (nel modulo codecs):          codecs — Codec registry and base classes.
                                                             (line   56)
* lookup() (nel modulo unicodedata):     unicodedata — Unicode Database.
                                                             (line   22)
* lookup() (symtable.SymbolTable metodo): Examining Symbol Tables.
                                                             (line  108)
* lookup() (tkinter.ttk.Style metodo):   Ttk Styling.        (line   81)
* LookupError:                           Base classes.       (line   83)
* loop control;target:                   The break statement.
                                                             (line   12)
* loop_factory (unittest.IsolatedAsyncioTestCase attributo): Test cases.
                                                             (line  924)
* loop;statement:                        The break statement.
                                                             (line    6)
* loop;statement <1>:                    The continue statement.
                                                             (line    6)
* loop;statement <2>:                    The while statement.
                                                             (line    6)
* loop;statement <3>:                    The for statement.  (line    6)
* LOOPBACK_TIMEOUT (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line   65)
* lower() (bytearray metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  642)
* lower() (bytes metodo):                Operazioni su Bytes e Bytearray.
                                                             (line  642)
* lower() (str metodo):                  Metodi per le Stringhe.
                                                             (line  473)
* LPAR (nel modulo token):               token — Constants used with Python parse trees.
                                                             (line  212)
* lpAttributeList (subprocess.STARTUPINFO attributo): Windows Popen Helpers.
                                                             (line   61)
* lru_cache() (nel modulo functools):    functools — Higher-order functions and operations on callable objects.
                                                             (line  143)
* lseek() (nel modulo os):               File Descriptor Operations.
                                                             (line  303)
* LShift (classe in ast):                Expressions<2>.     (line   53)
* lshift() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line  122)
* LSQB (nel modulo token):               token — Constants used with Python parse trees.
                                                             (line  218)
* lstat() (nel modulo os):               Files and Directories.
                                                             (line  480)
* lstat() (pathlib.Path metodo):         Querying file type and status.
                                                             (line   39)
* lstrip() (bytearray metodo):           Operazioni su Bytes e Bytearray.
                                                             (line  327)
* lstrip() (bytes metodo):               Operazioni su Bytes e Bytearray.
                                                             (line  327)
* lstrip() (str metodo):                 Metodi per le Stringhe.
                                                             (line  484)
* lsub() (imaplib.IMAP4 metodo):         IMAP4 Objects.      (line  232)
* Lt (classe in ast):                    Expressions<2>.     (line  108)
* lt() (nel modulo operator):            operator — Standard operators as functions.
                                                             (line   24)
* lt() (nel modulo turtle):              Turtle motion.      (line   57)
* LtE (classe in ast):                   Expressions<2>.     (line  108)
* LWPCookieJar (classe in http.cookiejar): FileCookieJar subclasses and co-operation with web browsers.
                                                             (line   28)
* LZMACompressor (classe in lzma):       Compressing and decompressing data in memory<2>.
                                                             (line    6)
* LZMADecompressor (classe in lzma):     Compressing and decompressing data in memory<2>.
                                                             (line  100)
* LZMAError:                             lzma — Compression using the LZMA algorithm.
                                                             (line   29)
* LZMAFile (classe in lzma):             Reading and writing compressed files<2>.
                                                             (line   45)
* M (nel modulo re):                     Flags.              (line   82)
* mac_ver() (nel modulo platform):       macOS platform.     (line    6)
* machine() (nel modulo platform):       Cross platform.     (line   35)
* macros (netrc.netrc attributo):        netrc Objects.      (line   29)
* MADV_AUTOSYNC (nel modulo mmap):       MADV_* Constants.   (line    6)
* MADV_CORE (nel modulo mmap):           MADV_* Constants.   (line    6)
* MADV_DODUMP (nel modulo mmap):         MADV_* Constants.   (line    6)
* MADV_DOFORK (nel modulo mmap):         MADV_* Constants.   (line    6)
* MADV_DONTDUMP (nel modulo mmap):       MADV_* Constants.   (line    6)
* MADV_DONTFORK (nel modulo mmap):       MADV_* Constants.   (line    6)
* MADV_DONTNEED (nel modulo mmap):       MADV_* Constants.   (line    6)
* MADV_FREE (nel modulo mmap):           MADV_* Constants.   (line    6)
* MADV_FREE_REUSABLE (nel modulo mmap):  MADV_* Constants.   (line    6)
* MADV_FREE_REUSE (nel modulo mmap):     MADV_* Constants.   (line    6)
* MADV_HUGEPAGE (nel modulo mmap):       MADV_* Constants.   (line    6)
* MADV_HWPOISON (nel modulo mmap):       MADV_* Constants.   (line    6)
* MADV_MERGEABLE (nel modulo mmap):      MADV_* Constants.   (line    6)
* MADV_NOCORE (nel modulo mmap):         MADV_* Constants.   (line    6)
* MADV_NOHUGEPAGE (nel modulo mmap):     MADV_* Constants.   (line    6)
* MADV_NORMAL (nel modulo mmap):         MADV_* Constants.   (line    6)
* MADV_NOSYNC (nel modulo mmap):         MADV_* Constants.   (line    6)
* MADV_PROTECT (nel modulo mmap):        MADV_* Constants.   (line    6)
* MADV_RANDOM (nel modulo mmap):         MADV_* Constants.   (line    6)
* MADV_REMOVE (nel modulo mmap):         MADV_* Constants.   (line    6)
* MADV_SEQUENTIAL (nel modulo mmap):     MADV_* Constants.   (line    6)
* MADV_SOFT_OFFLINE (nel modulo mmap):   MADV_* Constants.   (line    6)
* MADV_UNMERGEABLE (nel modulo mmap):    MADV_* Constants.   (line    6)
* MADV_WILLNEED (nel modulo mmap):       MADV_* Constants.   (line    6)
* madvise() (mmap.mmap metodo):          mmap — Memory-mapped file support.
                                                             (line  225)
* magic method:                          Glossary.           (line 1079)
* MAGIC_NUMBER (nel modulo importlib.util): importlib util – Utility code for importers.
                                                             (line   13)
* magic;method:                          Glossary.           (line 1083)
* MagicMock (classe in unittest.mock):   Magic Mock.         (line    9)
* Mailbox (classe in mailbox):           Mailbox objects.    (line    6)
* Maildir (classe in mailbox):           Maildir objects.    (line    6)
* MaildirMessage (classe in mailbox):    MaildirMessage objects.
                                                             (line    6)
* main_thread() (nel modulo threading):  Reference<2>.       (line  106)
* main():                                Process-wide parameters.
                                                             (line    7)
* main() <1>:                            Process-wide parameters.
                                                             (line  225)
* main() <2>:                            PyConfig.           (line  130)
* main() (nel modulo site):              Module contents<5>. (line   42)
* main() (nel modulo unittest):          Loading and running tests.
                                                             (line  517)
* mainloop() (nel modulo turtle):        Using screen events.
                                                             (line  106)
* maintype (email.headerregistry.ContentTypeHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  276)
* major (email.headerregistry.MIMEVersionHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  247)
* major() (nel modulo os):               Files and Directories.
                                                             (line  627)
* make_alternative() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  607)
* make_archive() (nel modulo shutil):    Archiving operations.
                                                             (line   14)
* make_bad_fd() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line  109)
* MAKE_CELL (opcode):                    Python Bytecode Instructions.
                                                             (line 1011)
* make_cookies() (http.cookiejar.CookieJar metodo): CookieJar and FileCookieJar Objects.
                                                             (line   61)
* make_dataclass() (nel modulo dataclasses): Module contents<4>.
                                                             (line  396)
* make_file() (difflib.HtmlDiff metodo): difflib — Helpers for computing deltas.
                                                             (line  112)
* MAKE_FUNCTION (opcode):                Python Bytecode Instructions.
                                                             (line 1150)
* make_header() (nel modulo email.header): email header Internationalized headers.
                                                             (line  220)
* make_legacy_pyc() (nel modulo test.support.import_helper): test support import_helper — Utilities for import tests.
                                                             (line   80)
* make_mixed() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  617)
* make_msgid() (nel modulo email.utils): email utils Miscellaneous utilities.
                                                             (line   27)
* make_parser() (nel modulo xml.sax):    xml sax — Support for SAX2 parsers.
                                                             (line   27)
* make_pkg() (nel modulo test.support.script_helper): test support script_helper — Utilities for the Python execution tests.
                                                             (line   97)
* make_related() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  598)
* make_script() (nel modulo test.support.script_helper): test support script_helper — Utilities for the Python execution tests.
                                                             (line   82)
* make_server() (nel modulo wsgiref.simple_server): wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line   14)
* make_table() (difflib.HtmlDiff metodo): difflib — Helpers for computing deltas.
                                                             (line  144)
* make_zip_pkg() (nel modulo test.support.script_helper): test support script_helper — Utilities for the Python execution tests.
                                                             (line  103)
* make_zip_script() (nel modulo test.support.script_helper): test support script_helper — Utilities for the Python execution tests.
                                                             (line   89)
* makedev() (nel modulo os):             Files and Directories.
                                                             (line  637)
* makedirs() (nel modulo os):            Files and Directories.
                                                             (line  546)
* makeelement() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line  164)
* makefile() (socket method):            I/O objects also known as file objects.
                                                             (line    6)
* makefile() (socket.socket metodo):     Socket Objects.     (line  210)
* makeLogRecord() (nel modulo logging):  Module-Level Functions.
                                                             (line  196)
* makePickle() (logging.handlers.SocketHandler metodo): SocketHandler.
                                                             (line   45)
* makeRecord() (logging.Logger metodo):  Logger Objects.     (line  376)
* makeSocket() (logging.handlers.DatagramHandler metodo): DatagramHandler.
                                                             (line   37)
* makeSocket() (logging.handlers.SocketHandler metodo): SocketHandler.
                                                             (line   39)
* maketrans() (bytearray metodo statico): Operazioni su Bytes e Bytearray.
                                                             (line  183)
* maketrans() (bytes metodo statico):    Operazioni su Bytes e Bytearray.
                                                             (line  183)
* maketrans() (str metodo statico):      Metodi per le Stringhe.
                                                             (line  507)
* MalformedHeaderDefect:                 email errors Exception and Defect classes.
                                                             (line  108)
* malloc (C function):                   Overview<4>.        (line   33)
* manager (logging.LoggerAdapter attributo): LoggerAdapter Objects.
                                                             (line   32)
* mangle_from_ (email.policy.Compat32 attributo): email policy Policy Objects.
                                                             (line  575)
* mangle_from_ (email.policy.Policy attributo): email policy Policy Objects.
                                                             (line  187)
* MANPAGER:                              pydoc — Documentation generator and online help system.
                                                             (line   46)
* MANPAGER <1>:                          pydoc — Documentation generator and online help system.
                                                             (line   48)
* mant_dig (sys.float_info attributo):   sys — System-specific parameters and functions.
                                                             (line  664)
* MAP_32BIT (nel modulo mmap):           MAP_* Constants.    (line    6)
* MAP_ADD (opcode):                      Python Bytecode Instructions.
                                                             (line  390)
* MAP_ALIGNED_SUPER (nel modulo mmap):   MAP_* Constants.    (line    6)
* MAP_ANON (nel modulo mmap):            MAP_* Constants.    (line    6)
* MAP_ANONYMOUS (nel modulo mmap):       MAP_* Constants.    (line    6)
* map_async() (multiprocessing.pool.Pool metodo): Process Pools.
                                                             (line  115)
* MAP_CONCEAL (nel modulo mmap):         MAP_* Constants.    (line    6)
* MAP_DENYWRITE (nel modulo mmap):       MAP_* Constants.    (line    6)
* MAP_EXECUTABLE (nel modulo mmap):      MAP_* Constants.    (line    6)
* MAP_HASSEMAPHORE (nel modulo mmap):    MAP_* Constants.    (line    6)
* MAP_JIT (nel modulo mmap):             MAP_* Constants.    (line    6)
* MAP_NOCACHE (nel modulo mmap):         MAP_* Constants.    (line    6)
* MAP_NOEXTEND (nel modulo mmap):        MAP_* Constants.    (line    6)
* MAP_NORESERVE (nel modulo mmap):       MAP_* Constants.    (line    6)
* MAP_POPULATE (nel modulo mmap):        MAP_* Constants.    (line    6)
* MAP_PRIVATE (nel modulo mmap):         MAP_* Constants.    (line    6)
* MAP_RESILIENT_CODESIGN (nel modulo mmap): MAP_* Constants. (line    6)
* MAP_RESILIENT_MEDIA (nel modulo mmap): MAP_* Constants.    (line    6)
* MAP_SHARED (nel modulo mmap):          MAP_* Constants.    (line    6)
* MAP_STACK (nel modulo mmap):           MAP_* Constants.    (line    6)
* map_table_b2() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   50)
* map_table_b3() (nel modulo stringprep): stringprep — Internet String Preparation.
                                                             (line   55)
* map_to_type() (email.headerregistry.HeaderRegistry metodo): email headerregistry Custom Header Objects.
                                                             (line  377)
* MAP_TPRO (nel modulo mmap):            MAP_* Constants.    (line    6)
* MAP_TRANSLATED_ALLOW_EXECUTE (nel modulo mmap): MAP_* Constants.
                                                             (line    6)
* MAP_UNIX03 (nel modulo mmap):          MAP_* Constants.    (line    6)
* map() (concurrent.futures.Executor metodo): Executor Objects.
                                                             (line   22)
* map() (multiprocessing.pool.Pool metodo): Process Pools.   (line   98)
* map() (tkinter.ttk.Style metodo):      Ttk Styling.        (line   48)
* mapLogRecord() (logging.handlers.HTTPHandler metodo): HTTPHandler.
                                                             (line   27)
* mapping:                               Glossary.           (line 1083)
* Mapping (classe in collections.abc):   Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  120)
* Mapping (classe in typing):            Aliases to container ABCs in collections abc.
                                                             (line   72)
* MappingProxyType (classe in types):    Standard Interpreter Types.
                                                             (line  228)
* MappingView (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  125)
* MappingView (classe in typing):        Aliases to container ABCs in collections abc.
                                                             (line   80)
* mapPriority() (logging.handlers.SysLogHandler metodo): SysLogHandler.
                                                             (line  207)
* maps (collections.ChainMap attributo): ChainMap objects.   (line   39)
* MARCH (nel modulo calendar):           calendar — General calendar-related functions.
                                                             (line  490)
* markcoroutinefunction() (nel modulo inspect): Types and members.
                                                             (line  469)
* marshalling;objects:                   pickle — Python object serialization.
                                                             (line    8)
* mascheramento;operazioni:              Operazioni Bitwise sui Tipi Integer.
                                                             (line    6)
* master (tkinter.Tk attributo):         Tkinter Modules.    (line   77)
* Match (classe in ast):                 Pattern matching.   (line    6)
* Match (classe in re):                  Match Objects.      (line   15)
* Match (classe in typing):              Aliases to other concrete types.
                                                             (line    6)
* match_case (classe in ast):            Pattern matching.   (line   15)
* MATCH_CLASS (opcode):                  Python Bytecode Instructions.
                                                             (line 1259)
* MATCH_KEYS (opcode):                   Python Bytecode Instructions.
                                                             (line  535)
* MATCH_MAPPING (opcode):                Python Bytecode Instructions.
                                                             (line  516)
* MATCH_SEQUENCE (opcode):               Python Bytecode Instructions.
                                                             (line  525)
* match_value() (test.support.Matcher metodo): test support — Utilities for the Python test suite.
                                                             (line  822)
* match;case:                            The match statement.
                                                             (line    6)
* match() (nel modulo re):               Functions.          (line   48)
* match() (pathlib.PurePath metodo):     Methods and properties.
                                                             (line  291)
* match() (re.Pattern metodo):           Regular Expression Objects.
                                                             (line   43)
* MatchAs (classe in ast):               Pattern matching.   (line  293)
* MatchClass (classe in ast):            Pattern matching.   (line  230)
* Matcher (classe in test.support):      test support — Utilities for the Python test suite.
                                                             (line  816)
* matches() (test.support.Matcher metodo): test support — Utilities for the Python test suite.
                                                             (line  818)
* MatchMapping (classe in ast):          Pattern matching.   (line  184)
* MatchOr (classe in ast):               Pattern matching.   (line  333)
* MatchSequence (classe in ast):         Pattern matching.   (line  114)
* MatchSingleton (classe in ast):        Pattern matching.   (line   90)
* MatchStar (classe in ast):             Pattern matching.   (line  144)
* MatchValue (classe in ast):            Pattern matching.   (line   63)
* matmul() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line  137)
* MatMult (classe in ast):               Expressions<2>.     (line   53)
* matrix multiplication:                 Binary arithmetic operations.
                                                             (line   29)
* max (datetime.date attributo):         date Objects.       (line  135)
* max (datetime.datetime attributo):     datetime Objects.   (line  293)
* max (datetime.time attributo):         time Objects.       (line   37)
* max (datetime.timedelta attributo):    timedelta Objects.  (line   93)
* MAX (nel modulo uuid):                 uuid — UUID objects according to RFC 9562.
                                                             (line  324)
* max (sys.float_info attributo):        sys — System-specific parameters and functions.
                                                             (line  669)
* max_10_exp (sys.float_info attributo): sys — System-specific parameters and functions.
                                                             (line  678)
* max_children (socketserver.ThreadingMixIn attributo): Server Creation Notes.
                                                             (line   55)
* max_count (email.headerregistry.BaseHeader attributo): email headerregistry Custom Header Objects.
                                                             (line   60)
* MAX_EMAX (nel modulo decimal):         Constants<4>.       (line   16)
* max_exp (sys.float_info attributo):    sys — System-specific parameters and functions.
                                                             (line  673)
* MAX_INTERPOLATION_DEPTH (nel modulo configparser): ConfigParser Objects.
                                                             (line  350)
* max_line_length (email.policy.Policy attributo): email policy Policy Objects.
                                                             (line  146)
* max_lines (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  274)
* max_mag() (decimal.Context metodo):    Context objects.    (line  411)
* max_mag() (decimal.Decimal metodo):    Decimal objects.    (line  399)
* max_memuse (nel modulo test.support):  test support — Utilities for the Python test suite.
                                                             (line  162)
* MAX_PREC (nel modulo decimal):         Constants<4>.       (line   13)
* max_prefixlen (ipaddress.IPv4Address attributo): Address objects.
                                                             (line   51)
* max_prefixlen (ipaddress.IPv4Network attributo): Network objects.
                                                             (line   65)
* max_prefixlen (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  277)
* max_prefixlen (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  296)
* MAX_Py_ssize_t (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  158)
* MAX_WBITS (nel modulo zlib):           zlib — Compression compatible with gzip.
                                                             (line  311)
* max() (decimal.Context metodo):        Context objects.    (line  407)
* max() (decimal.Decimal metodo):        Decimal objects.    (line  392)
* maxarray (reprlib.Repr attributo):     Repr Objects.       (line   22)
* maxdeque (reprlib.Repr attributo):     Repr Objects.       (line   22)
* maxdict (reprlib.Repr attributo):      Repr Objects.       (line   22)
* maxDiff (unittest.TestCase attributo): Test cases.         (line  783)
* maxfrozenset (reprlib.Repr attributo): Repr Objects.       (line   22)
* MAXIMUM_SUPPORTED (ssl.TLSVersion attributo): Constants<9>.
                                                             (line  571)
* maximum_version (ssl.SSLContext attributo): SSL Contexts.  (line  539)
* maxlen (collections.deque attributo):  deque objects.      (line  120)
* maxlevel (reprlib.Repr attributo):     Repr Objects.       (line   17)
* maxlist (reprlib.Repr attributo):      Repr Objects.       (line   22)
* maxlong (reprlib.Repr attributo):      Repr Objects.       (line   34)
* maxother (reprlib.Repr attributo):     Repr Objects.       (line   47)
* maxset (reprlib.Repr attributo):       Repr Objects.       (line   22)
* maxsize (asyncio.Queue attributo):     Queue.              (line   23)
* maxsize (nel modulo sys):              sys — System-specific parameters and functions.
                                                             (line 1376)
* maxstring (reprlib.Repr attributo):    Repr Objects.       (line   39)
* maxtuple (reprlib.Repr attributo):     Repr Objects.       (line   22)
* maxunicode (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line 1382)
* MAXYEAR (nel modulo datetime):         Constants.          (line   13)
* MAY (nel modulo calendar):             calendar — General calendar-related functions.
                                                             (line  490)
* MB_ICONASTERISK (nel modulo winsound): winsound — Sound-playing interface for Windows.
                                                             (line  155)
* MB_ICONERROR (nel modulo winsound):    winsound — Sound-playing interface for Windows.
                                                             (line  175)
* MB_ICONEXCLAMATION (nel modulo winsound): winsound — Sound-playing interface for Windows.
                                                             (line  159)
* MB_ICONHAND (nel modulo winsound):     winsound — Sound-playing interface for Windows.
                                                             (line  163)
* MB_ICONINFORMATION (nel modulo winsound): winsound — Sound-playing interface for Windows.
                                                             (line  181)
* MB_ICONQUESTION (nel modulo winsound): winsound — Sound-playing interface for Windows.
                                                             (line  167)
* MB_ICONSTOP (nel modulo winsound):     winsound — Sound-playing interface for Windows.
                                                             (line  187)
* MB_ICONWARNING (nel modulo winsound):  winsound — Sound-playing interface for Windows.
                                                             (line  193)
* MB_OK (nel modulo winsound):           winsound — Sound-playing interface for Windows.
                                                             (line  171)
* mbox (classe in mailbox):              mbox objects.       (line    6)
* mboxMessage (classe in mailbox):       mboxMessage objects.
                                                             (line    6)
* md5() (nel modulo hashlib):            Constructors.       (line   20)
* mean (statistics.NormalDist attributo): NormalDist objects.
                                                             (line   21)
* mean() (nel modulo statistics):        Function details.   (line   10)
* measure() (tkinter.font.Font metodo):  tkinter font — Tkinter font wrapper.
                                                             (line   63)
* median (statistics.NormalDist attributo): NormalDist objects.
                                                             (line   26)
* median_grouped() (nel modulo statistics): Function details.
                                                             (line  274)
* median_high() (nel modulo statistics): Function details.   (line  256)
* median_low() (nel modulo statistics):  Function details.   (line  238)
* median() (nel modulo statistics):      Function details.   (line  211)
* member_names (enum.EnumDict attributo): Data Types<2>.     (line  754)
* member() (nel modulo enum):            Utilities and Decorators.
                                                             (line   80)
* MemberDescriptorType (nel modulo types): Standard Interpreter Types.
                                                             (line  211)
* membership;test:                       Membership test operations.
                                                             (line   36)
* memfd_create() (nel modulo os):        Files and Directories.
                                                             (line 1814)
* memmove() (nel modulo ctypes):         Utility functions.  (line  203)
* MemoryBIO (classe in ssl):             Memory BIO Support<2>.
                                                             (line  134)
* MemoryError:                           Concrete exceptions.
                                                             (line  107)
* MemoryHandler (classe in logging.handlers): MemoryHandler. (line   41)
* memoryview (classe built-in):          Memory Views.       (line   10)
* memoryview_at() (nel modulo ctypes):   Utility functions.  (line  301)
* memset() (nel modulo ctypes):          Utility functions.  (line  209)
* merge() (nel modulo heapq):            heapq — Heap queue algorithm.
                                                             (line  142)
* message (BaseExceptionGroup attributo): Exception groups.  (line   33)
* Message (classe in email.message):     email message Message Representing an email message using the compat32 API.
                                                             (line   49)
* Message (classe in mailbox):           Message objects.    (line    6)
* Message (classe in tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line   21)
* message digest, MD5:                   hashlib — Secure hashes and message digests.
                                                             (line    8)
* message_factory (email.policy.Policy attributo): email policy Policy Objects.
                                                             (line  196)
* message_from_binary_file() (nel modulo email): Parser API. (line  131)
* message_from_bytes() (nel modulo email): Parser API.       (line  118)
* message_from_file() (nel modulo email): Parser API.        (line  154)
* message_from_string() (nel modulo email): Parser API.      (line  144)
* MessageBeep() (nel modulo winsound):   winsound — Sound-playing interface for Windows.
                                                             (line   33)
* MessageClass (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  220)
* MessageDefect:                         email errors Exception and Defect classes.
                                                             (line   55)
* MessageError:                          email errors Exception and Defect classes.
                                                             (line   13)
* MessageParseError:                     email errors Exception and Defect classes.
                                                             (line   19)
* messages (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   22)
* meta hooks:                            Import hooks.       (line    6)
* meta path finder:                      Glossary.           (line 1093)
* meta_path (nel modulo sys):            sys — System-specific parameters and functions.
                                                             (line 1392)
* meta() (nel modulo curses):            Functions<5>.       (line  303)
* metaclass:                             Metaclasses.        (line    6)
* metaclass <1>:                         Glossary.           (line 1102)
* metaclass hint:                        Determining the appropriate metaclass.
                                                             (line    6)
* metadata() (nel modulo importlib.metadata): Distribution metadata.
                                                             (line    6)
* MetaPathFinder (classe in importlib.abc): importlib abc – Abstract base classes related to import.
                                                             (line   27)
* metavar (optparse.Option attributo):   Option attributes.  (line   88)
* MetavarTypeHelpFormatter (classe in argparse): formatter_class.
                                                             (line   10)
* METH_CLASS (C macro):                  Implementing functions and methods.
                                                             (line  194)
* METH_COEXIST (C macro):                Implementing functions and methods.
                                                             (line  213)
* METH_FASTCALL (C macro):               Implementing functions and methods.
                                                             (line  124)
* METH_KEYWORDS (C macro):               Implementing functions and methods.
                                                             (line  108)
* METH_METHOD (C macro):                 Implementing functions and methods.
                                                             (line  151)
* METH_NOARGS (C macro):                 Implementing functions and methods.
                                                             (line  169)
* METH_O (C macro):                      Implementing functions and methods.
                                                             (line  181)
* METH_STATIC (C macro):                 Implementing functions and methods.
                                                             (line  202)
* METH_VARARGS (C macro):                Implementing functions and methods.
                                                             (line   98)
* method:                                Glossary.           (line 1117)
* method (urllib.request.Request attributo): Request Objects.
                                                             (line   52)
* method resolution order:               Glossary.           (line 1125)
* method_calls (unittest.mock.Mock attributo): The Mock Class.
                                                             (line  506)
* method;call:                           Calls.              (line  143)
* methodcaller() (nel modulo operator):  operator — Standard operators as functions.
                                                             (line  333)
* MethodDescriptorType (nel modulo types): Standard Interpreter Types.
                                                             (line  109)
* methodHelp() (xmlrpc.client.ServerProxy.system metodo): ServerProxy Objects.
                                                             (line   43)
* methods (pyclbr.Class attributo):      Class Objects.      (line   50)
* methodSignature() (xmlrpc.client.ServerProxy.system metodo): ServerProxy Objects.
                                                             (line   22)
* MethodType (in module types):          Function Objects<3>.
                                                             (line   14)
* MethodType (in module types) <1>:      Method Objects.     (line   12)
* MethodType (nel modulo types):         Standard Interpreter Types.
                                                             (line   77)
* MethodWrapperType (nel modulo types):  Standard Interpreter Types.
                                                             (line   96)
* metrics() (tkinter.font.Font metodo):  tkinter font — Tkinter font wrapper.
                                                             (line   69)
* MFD_ALLOW_SEALING (nel modulo os):     Files and Directories.
                                                             (line 1832)
* MFD_CLOEXEC (nel modulo os):           Files and Directories.
                                                             (line 1832)
* MFD_HUGE_16GB (nel modulo os):         Files and Directories.
                                                             (line 1832)
* MFD_HUGE_16MB (nel modulo os):         Files and Directories.
                                                             (line 1832)
* MFD_HUGE_1GB (nel modulo os):          Files and Directories.
                                                             (line 1832)
* MFD_HUGE_1MB (nel modulo os):          Files and Directories.
                                                             (line 1832)
* MFD_HUGE_256MB (nel modulo os):        Files and Directories.
                                                             (line 1832)
* MFD_HUGE_2GB (nel modulo os):          Files and Directories.
                                                             (line 1832)
* MFD_HUGE_2MB (nel modulo os):          Files and Directories.
                                                             (line 1832)
* MFD_HUGE_32MB (nel modulo os):         Files and Directories.
                                                             (line 1832)
* MFD_HUGE_512KB (nel modulo os):        Files and Directories.
                                                             (line 1832)
* MFD_HUGE_512MB (nel modulo os):        Files and Directories.
                                                             (line 1832)
* MFD_HUGE_64KB (nel modulo os):         Files and Directories.
                                                             (line 1832)
* MFD_HUGE_8MB (nel modulo os):          Files and Directories.
                                                             (line 1832)
* MFD_HUGE_MASK (nel modulo os):         Files and Directories.
                                                             (line 1832)
* MFD_HUGE_SHIFT (nel modulo os):        Files and Directories.
                                                             (line 1832)
* MFD_HUGETLB (nel modulo os):           Files and Directories.
                                                             (line 1832)
* MH (classe in mailbox):                MH objects.         (line    6)
* MHMessage (classe in mailbox):         MHMessage objects.  (line    6)
* microsecond (datetime.datetime attributo): datetime Objects.
                                                             (line  330)
* microsecond (datetime.time attributo): time Objects.       (line   62)
* microseconds (datetime.timedelta attributo): timedelta Objects.
                                                             (line  129)
* MIME;base64 encoding:                  base64 — Base16 Base32 Base64 Base85 Data Encodings.
                                                             (line    8)
* MIME;content type:                     mimetypes — Map filenames to MIME types.
                                                             (line    8)
* MIME;headers:                          mimetypes — Map filenames to MIME types.
                                                             (line   26)
* MIME;headers <1>:                      mimetypes — Map filenames to MIME types.
                                                             (line   60)
* MIME;quoted-printable encoding:        quopri — Encode and decode MIME quoted-printable data.
                                                             (line    8)
* MIMEApplication (classe in email.mime.application): email mime Creating email and MIME objects from scratch.
                                                             (line   95)
* MIMEAudio (classe in email.mime.audio): email mime Creating email and MIME objects from scratch.
                                                             (line  125)
* MIMEBase (classe in email.mime.base):  email mime Creating email and MIME objects from scratch.
                                                             (line   30)
* MIMEImage (classe in email.mime.image): email mime Creating email and MIME objects from scratch.
                                                             (line  157)
* MIMEMessage (classe in email.mime.message): email mime Creating email and MIME objects from scratch.
                                                             (line  190)
* MIMEMultipart (classe in email.mime.multipart): email mime Creating email and MIME objects from scratch.
                                                             (line   66)
* MIMENonMultipart (classe in email.mime.nonmultipart): email mime Creating email and MIME objects from scratch.
                                                             (line   55)
* MIMEPart (classe in email.message):    email message Representing an email message.
                                                             (line  718)
* MIMEText (classe in email.mime.text):  email mime Creating email and MIME objects from scratch.
                                                             (line  208)
* MimeTypes (classe in mimetypes):       MimeTypes objects.  (line   10)
* mimetypes command line option; -e:     Command-line usage<4>.
                                                             (line   18)
* mimetypes command line option; -extension: Command-line usage<4>.
                                                             (line   18)
* mimetypes command line option; -h:     Command-line usage<4>.
                                                             (line   13)
* mimetypes command line option; -help:  Command-line usage<4>.
                                                             (line   13)
* mimetypes command line option; -l:     Command-line usage<4>.
                                                             (line   23)
* mimetypes command line option; -lenient: Command-line usage<4>.
                                                             (line   23)
* MIMEVersionHeader (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  234)
* min (datetime.date attributo):         date Objects.       (line  131)
* min (datetime.datetime attributo):     datetime Objects.   (line  288)
* min (datetime.time attributo):         time Objects.       (line   33)
* min (datetime.timedelta attributo):    timedelta Objects.  (line   88)
* min (sys.float_info attributo):        sys — System-specific parameters and functions.
                                                             (line  683)
* min_10_exp (sys.float_info attributo): sys — System-specific parameters and functions.
                                                             (line  696)
* MIN_EMIN (nel modulo decimal):         Constants<4>.       (line   19)
* MIN_ETINY (nel modulo decimal):        Constants<4>.       (line   22)
* min_exp (sys.float_info attributo):    sys — System-specific parameters and functions.
                                                             (line  691)
* min_mag() (decimal.Context metodo):    Context objects.    (line  419)
* min_mag() (decimal.Decimal metodo):    Decimal objects.    (line  411)
* min_match (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line   93)
* min() (decimal.Context metodo):        Context objects.    (line  415)
* min() (decimal.Decimal metodo):        Decimal objects.    (line  404)
* MINEQUAL (nel modulo token):           token — Constants used with Python parse trees.
                                                             (line  302)
* MINIMUM_SUPPORTED (ssl.TLSVersion attributo): Constants<9>.
                                                             (line  569)
* minimum_version (ssl.SSLContext attributo): SSL Contexts.  (line  557)
* minor (email.headerregistry.MIMEVersionHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  251)
* minor() (nel modulo os):               Files and Directories.
                                                             (line  632)
* minus:                                 Unary arithmetic and bitwise operations.
                                                             (line   10)
* MINUS (nel modulo token):              token — Constants used with Python parse trees.
                                                             (line  236)
* minus() (decimal.Context metodo):      Context objects.    (line  423)
* minute (datetime.datetime attributo):  datetime Objects.   (line  322)
* minute (datetime.time attributo):      time Objects.       (line   54)
* MINYEAR (nel modulo datetime):         Constants.          (line    8)
* mirrored() (nel modulo unicodedata):   unicodedata — Unicode Database.
                                                             (line  114)
* misc_header (cmd.Cmd attributo):       Cmd Objects.        (line  160)
* MisplacedEnvelopeHeaderDefect:         email errors Exception and Defect classes.
                                                             (line   96)
* MISSING (contextvars.Token attributo): Context Variables.  (line  130)
* MISSING (nel modulo dataclasses):      Module contents<4>. (line  489)
* MISSING (nel modulo sys.monitoring):   Callback function arguments.
                                                             (line    6)
* MISSING_C_DOCSTRINGS (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  172)
* missing_compiler_executable() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  705)
* MissingHeaderBodySeparatorDefect:      email errors Exception and Defect classes.
                                                             (line  100)
* MissingSectionHeaderError:             Exceptions<8>.      (line   60)
* mkd() (ftplib.FTP metodo):             FTP objects.        (line  341)
* mkdir() (nel modulo os):               Files and Directories.
                                                             (line  512)
* mkdir() (pathlib.Path metodo):         Creating files and directories.
                                                             (line   21)
* mkdir() (zipfile.ZipFile metodo):      ZipFile objects.    (line  345)
* mkdtemp() (nel modulo tempfile):       tempfile — Generate temporary files and directories.
                                                             (line  291)
* mkfifo() (nel modulo os):              Files and Directories.
                                                             (line  586)
* mknod() (nel modulo os):               Files and Directories.
                                                             (line  607)
* mkstemp() (nel modulo tempfile):       tempfile — Generate temporary files and directories.
                                                             (line  230)
* mktemp() (nel modulo tempfile):        Deprecated functions and variables.
                                                             (line   15)
* mktime_tz() (nel modulo email.utils):  email utils Miscellaneous utilities.
                                                             (line  146)
* mktime() (nel modulo time):            Functions<4>.       (line  162)
* mlsd() (ftplib.FTP metodo):            FTP objects.        (line  287)
* mmap (classe in mmap):                 mmap — Memory-mapped file support.
                                                             (line   54)
* MMDF (classe in mailbox):              MMDF objects.       (line    6)
* MMDFMessage (classe in mailbox):       MMDFMessage objects.
                                                             (line    6)
* Mock (classe in unittest.mock):        The Mock Class.     (line   24)
* mock_add_spec() (unittest.mock.Mock metodo): The Mock Class.
                                                             (line  249)
* mock_calls (unittest.mock.Mock attributo): The Mock Class. (line  524)
* mock_open() (nel modulo unittest.mock): mock_open.         (line    6)
* Mod (classe in ast):                   Expressions<2>.     (line   53)
* mod() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line  127)
* modalità binaria:                      Funzioni Incorporate.
                                                             (line 1539)
* modalità testo:                        Funzioni Incorporate.
                                                             (line 1539)
* mode (bz2.BZ2File attributo):          De compression of files.
                                                             (line  130)
* mode (compression.zstd.ZstdFile attributo): Reading and writing compressed files.
                                                             (line  106)
* mode (gzip.GzipFile attributo):        gzip — Support for gzip files.
                                                             (line  149)
* mode (io.FileIO attributo):            Raw File I/O.       (line   56)
* mode (lzma.LZMAFile attributo):        Reading and writing compressed files<2>.
                                                             (line  100)
* mode (statistics.NormalDist attributo): NormalDist objects.
                                                             (line   31)
* mode (tarfile.TarInfo attributo):      TarInfo Objects.    (line   78)
* mode() (nel modulo statistics):        Function details.   (line  323)
* mode() (nel modulo turtle):            Settings and special methods.
                                                             (line    6)
* modf() (nel modulo math):              Floating point arithmetic.
                                                             (line   55)
* modified() (urllib.robotparser.RobotFileParser metodo): urllib robotparser — Parser for robots txt.
                                                             (line   45)
* modify() (select.devpoll metodo):      /dev/poll Polling Objects.
                                                             (line   49)
* modify() (select.epoll metodo):        Edge and Level Trigger Polling epoll Objects.
                                                             (line   91)
* modify() (select.poll metodo):         Polling Objects.    (line   60)
* modify() (selectors.BaseSelector metodo): Classes<3>.      (line   94)
* module:                                Glossary.           (line 1132)
* Module (classe in ast):                Root nodes.         (line    6)
* module (pyclbr.Class attributo):       Class Objects.      (line   16)
* module (pyclbr.Function attributo):    Function Objects.   (line   15)
* MODULE (symtable.SymbolTableType attributo): Examining Symbol Tables.
                                                             (line   11)
* Module browser:                        File menu Shell and Editor.
                                                             (line   22)
* module spec:                           Finders and loaders.
                                                             (line    6)
* module spec <1>:                       Glossary.           (line 1141)
* module_from_spec() (nel modulo importlib.util): importlib util – Utility code for importers.
                                                             (line  121)
* module; __future__:                    __future__ — Future statement definitions.
                                                             (line    6)
* module; __main__:                      __main__ — Top-level code environment.
                                                             (line    6)
* module; _thread:                       _thread — Low-level threading API.
                                                             (line    6)
* module; _tkinter:                      Tkinter Modules.    (line  150)
* module; abc:                           abc — Abstract Base Classes.
                                                             (line    6)
* module; aifc:                          aifc — Read and write AIFF and AIFC files.
                                                             (line    6)
* module; annotationlib:                 annotationlib — Functionality for introspecting annotations.
                                                             (line    6)
* module; argparse:                      argparse — Parser for command-line options arguments and subcommands.
                                                             (line    6)
* module; array:                         array — Efficient arrays of numeric values.
                                                             (line    6)
* module; ast:                           ast — Abstract syntax trees.
                                                             (line    6)
* module; asynchat:                      asynchat — Asynchronous socket command/response handler.
                                                             (line    6)
* module; asyncio:                       asyncio — Asynchronous I/O.
                                                             (line    6)
* module; asyncore:                      asyncore — Asynchronous socket handler.
                                                             (line    6)
* module; atexit:                        atexit — Exit handlers.
                                                             (line    6)
* module; audioop:                       audioop — Manipulate raw audio data.
                                                             (line    6)
* module; base64:                        base64 — Base16 Base32 Base64 Base85 Data Encodings.
                                                             (line    6)
* module; bdb:                           bdb — Debugger framework.
                                                             (line    6)
* module; binascii:                      binascii — Convert between binary and ASCII.
                                                             (line    6)
* module; bisect:                        bisect — Array bisection algorithm.
                                                             (line    6)
* module; builtins:                      builtins — Built-in objects.
                                                             (line    6)
* module; bz2:                           bz2 — Support for bzip2 compression.
                                                             (line    6)
* module; calendar:                      calendar — General calendar-related functions.
                                                             (line    6)
* module; cgi:                           cgi — Common Gateway Interface support.
                                                             (line    6)
* module; cgitb:                         cgitb — Traceback manager for CGI scripts.
                                                             (line    6)
* module; chunk:                         chunk — Read IFF chunked data.
                                                             (line    6)
* module; cmath:                         cmath — Mathematical functions for complex numbers.
                                                             (line    6)
* module; cmd:                           cmd — Support for line-oriented command interpreters.
                                                             (line    6)
* module; code:                          code — Interpreter base classes.
                                                             (line    6)
* module; codecs:                        codecs — Codec registry and base classes.
                                                             (line    6)
* module; codeop:                        codeop — Compile Python code.
                                                             (line    6)
* module; collections:                   collections — Container datatypes.
                                                             (line    6)
* module; collections.abc:               collections abc — Abstract Base Classes for Containers.
                                                             (line    6)
* module; colorsys:                      colorsys — Conversions between color systems.
                                                             (line    6)
* module; compileall:                    compileall — Byte-compile Python libraries.
                                                             (line    6)
* module; compression:                   The compression package.
                                                             (line    6)
* module; compression.zstd:              compression zstd — Compression compatible with the Zstandard format.
                                                             (line    6)
* module; concurrent.futures:            concurrent futures — Launching parallel tasks.
                                                             (line    6)
* module; concurrent.interpreters:       concurrent interpreters — Multiple interpreters in the same process.
                                                             (line    6)
* module; configparser:                  configparser — Configuration file parser.
                                                             (line    6)
* module; contextlib:                    contextlib — Utilities for with-statement contexts.
                                                             (line    6)
* module; contextvars:                   contextvars — Context Variables.
                                                             (line    6)
* module; copy:                          copy — Shallow and deep copy operations.
                                                             (line    6)
* module; copyreg:                       copyreg — Register pickle support functions.
                                                             (line    6)
* module; cProfile:                      profile and cProfile Module Reference.
                                                             (line    6)
* module; crypt:                         crypt — Function to check Unix passwords.
                                                             (line    6)
* module; csv:                           csv — CSV File Reading and Writing.
                                                             (line    6)
* module; ctypes:                        ctypes — A foreign function library for Python.
                                                             (line    6)
* module; curses:                        curses — Terminal handling for character-cell displays.
                                                             (line    6)
* module; curses.ascii:                  curses ascii — Utilities for ASCII characters.
                                                             (line    6)
* module; curses.panel:                  curses panel — A panel stack extension for curses.
                                                             (line    6)
* module; curses.textpad:                curses textpad — Text input widget for curses programs.
                                                             (line    6)
* module; dataclasses:                   dataclasses — Data Classes.
                                                             (line    6)
* module; datetime:                      datetime — Basic date and time types.
                                                             (line    6)
* module; dbm:                           dbm — Interfaces to Unix «databases».
                                                             (line    6)
* module; dbm.dumb:                      dbm dumb — Portable DBM implementation.
                                                             (line    6)
* module; dbm.gnu:                       dbm gnu — GNU database manager.
                                                             (line    6)
* module; dbm.ndbm:                      dbm ndbm — New Database Manager.
                                                             (line    6)
* module; dbm.sqlite3:                   dbm sqlite3 — SQLite backend for dbm.
                                                             (line    6)
* module; decimal:                       decimal — Decimal fixed-point and floating-point arithmetic.
                                                             (line    6)
* module; difflib:                       difflib — Helpers for computing deltas.
                                                             (line    6)
* module; dis:                           dis — Disassembler for Python bytecode.
                                                             (line    6)
* module; distutils:                     distutils — Building and installing Python modules.
                                                             (line    6)
* module; doctest:                       doctest — Test interactive Python examples.
                                                             (line    6)
* module; email:                         email — An email and MIME handling package.
                                                             (line    6)
* module; email.charset:                 email charset Representing character sets.
                                                             (line    6)
* module; email.contentmanager:          email contentmanager Managing MIME Content.
                                                             (line    6)
* module; email.encoders:                email encoders Encoders.
                                                             (line    6)
* module; email.errors:                  email errors Exception and Defect classes.
                                                             (line    6)
* module; email.generator:               email generator Generating MIME documents.
                                                             (line    6)
* module; email.header:                  email header Internationalized headers.
                                                             (line    6)
* module; email.headerregistry:          email headerregistry Custom Header Objects.
                                                             (line    6)
* module; email.iterators:               email iterators Iterators.
                                                             (line    6)
* module; email.message:                 email message Representing an email message.
                                                             (line    6)
* module; email.mime:                    email mime Creating email and MIME objects from scratch.
                                                             (line    6)
* module; email.mime.application:        email mime Creating email and MIME objects from scratch.
                                                             (line   95)
* module; email.mime.audio:              email mime Creating email and MIME objects from scratch.
                                                             (line  125)
* module; email.mime.base:               email mime Creating email and MIME objects from scratch.
                                                             (line   30)
* module; email.mime.image:              email mime Creating email and MIME objects from scratch.
                                                             (line  157)
* module; email.mime.message:            email mime Creating email and MIME objects from scratch.
                                                             (line  190)
* module; email.mime.multipart:          email mime Creating email and MIME objects from scratch.
                                                             (line   66)
* module; email.mime.nonmultipart:       email mime Creating email and MIME objects from scratch.
                                                             (line   55)
* module; email.mime.text:               email mime Creating email and MIME objects from scratch.
                                                             (line  208)
* module; email.parser:                  email parser Parsing email messages.
                                                             (line    6)
* module; email.policy:                  email policy Policy Objects.
                                                             (line    6)
* module; email.utils:                   email utils Miscellaneous utilities.
                                                             (line    6)
* module; encodings:                     encodings — Encodings package.
                                                             (line    6)
* module; encodings.idna:                encodings idna — Internationalized Domain Names in Applications.
                                                             (line    6)
* module; encodings.mbcs:                encodings mbcs — Windows ANSI codepage.
                                                             (line    6)
* module; encodings.utf_8_sig:           encodings utf_8_sig — UTF-8 codec with BOM signature.
                                                             (line    6)
* module; ensurepip:                     ensurepip — Bootstrapping the pip installer.
                                                             (line    6)
* module; enum:                          enum — Support for enumerations.
                                                             (line    6)
* module; errno:                         errno — Standard errno system symbols.
                                                             (line    6)
* module; faulthandler:                  faulthandler — Dump the Python traceback.
                                                             (line    6)
* module; fcntl:                         fcntl — The fcntl and ioctl system calls.
                                                             (line    6)
* module; filecmp:                       filecmp — File and Directory Comparisons.
                                                             (line    6)
* module; fileinput:                     fileinput — Iterate over lines from multiple input streams.
                                                             (line    6)
* module; fnmatch:                       fnmatch — Unix filename pattern matching.
                                                             (line    6)
* module; fractions:                     fractions — Rational numbers.
                                                             (line    6)
* module; ftplib:                        ftplib — FTP protocol client.
                                                             (line    6)
* module; functools:                     functools — Higher-order functions and operations on callable objects.
                                                             (line    6)
* module; gc:                            gc — Garbage Collector interface.
                                                             (line    6)
* module; getopt:                        getopt — C-style parser for command line options.
                                                             (line    6)
* module; getpass:                       getpass — Portable password input.
                                                             (line    6)
* module; gettext:                       gettext — Multilingual internationalization services.
                                                             (line    6)
* module; glob:                          glob — Unix style pathname pattern expansion.
                                                             (line    6)
* module; graphlib:                      graphlib — Functionality to operate with graph-like structures.
                                                             (line    6)
* module; grp:                           grp — The group database.
                                                             (line    6)
* module; gzip:                          gzip — Support for gzip files.
                                                             (line    6)
* module; hashlib:                       hashlib — Secure hashes and message digests.
                                                             (line    6)
* module; heapq:                         heapq — Heap queue algorithm.
                                                             (line    6)
* module; hmac:                          hmac — Keyed-Hashing for Message Authentication.
                                                             (line    6)
* module; html:                          html — HyperText Markup Language support.
                                                             (line    6)
* module; html.entities:                 html entities — Definitions of HTML general entities.
                                                             (line    6)
* module; html.parser:                   html parser — Simple HTML and XHTML parser.
                                                             (line    6)
* module; http:                          http — HTTP modules.
                                                             (line    6)
* module; http.client:                   http client — HTTP protocol client.
                                                             (line    6)
* module; http.cookiejar:                http cookiejar — Cookie handling for HTTP clients.
                                                             (line    6)
* module; http.cookies:                  http cookies — HTTP state management.
                                                             (line    6)
* module; http.server:                   http server — HTTP servers.
                                                             (line    6)
* module; idlelib:                       idlelib — implementation of IDLE application.
                                                             (line    6)
* module; imaplib:                       imaplib — IMAP4 protocol client.
                                                             (line    6)
* module; imghdr:                        imghdr — Determine the type of an image.
                                                             (line    6)
* module; imp:                           imp — Access the import internals.
                                                             (line    6)
* module; importlib:                     importlib — The implementation of import.
                                                             (line    6)
* module; importlib.abc:                 importlib abc – Abstract base classes related to import.
                                                             (line    6)
* module; importlib.machinery:           importlib machinery – Importers and path hooks.
                                                             (line    6)
* module; importlib.metadata:            importlib metadata – Accessing package metadata.
                                                             (line    6)
* module; importlib.resources:           importlib resources – Package resource reading opening and access.
                                                             (line    6)
* module; importlib.resources.abc:       importlib resources abc – Abstract base classes for resources.
                                                             (line    6)
* module; importlib.util:                importlib util – Utility code for importers.
                                                             (line    6)
* module; inspect:                       inspect — Inspect live objects.
                                                             (line    6)
* module; io:                            io — Core tools for working with streams.
                                                             (line    6)
* module; ipaddress:                     ipaddress — IPv4/IPv6 manipulation library.
                                                             (line    6)
* module; itertools:                     itertools — Functions creating iterators for efficient looping.
                                                             (line    6)
* module; json:                          json — JSON encoder and decoder.
                                                             (line    6)
* module; json.tool:                     Command-line interface<5>.
                                                             (line    6)
* module; keyword:                       keyword — Testing for Python keywords.
                                                             (line    6)
* module; linecache:                     linecache — Random access to text lines.
                                                             (line    6)
* module; locale:                        locale — Internationalization services.
                                                             (line    6)
* module; logging:                       logging — Logging facility for Python.
                                                             (line    6)
* module; logging.config:                logging config — Logging configuration.
                                                             (line    6)
* module; logging.handlers:              logging handlers — Logging handlers.
                                                             (line    6)
* module; lzma:                          lzma — Compression using the LZMA algorithm.
                                                             (line    6)
* module; mailbox:                       mailbox — Manipulate mailboxes in various formats.
                                                             (line    6)
* module; mailcap:                       mailcap — Mailcap file handling.
                                                             (line    6)
* module; marshal:                       marshal — Internal Python object serialization.
                                                             (line    6)
* module; math:                          math — Mathematical functions.
                                                             (line    6)
* module; mimetypes:                     mimetypes — Map filenames to MIME types.
                                                             (line    6)
* module; mmap:                          mmap — Memory-mapped file support.
                                                             (line    6)
* module; modulefinder:                  modulefinder — Find modules used by a script.
                                                             (line    6)
* module; msilib:                        msilib — Read and write Microsoft Installer files.
                                                             (line    6)
* module; msvcrt:                        msvcrt — Useful routines from the MS VC++ runtime.
                                                             (line    6)
* module; multiprocessing:               multiprocessing — Process-based parallelism.
                                                             (line    6)
* module; multiprocessing.connection:    Listeners and Clients.
                                                             (line    6)
* module; multiprocessing.dummy:         The multiprocessing dummy module.
                                                             (line    6)
* module; multiprocessing.managers:      Managers.           (line   19)
* module; multiprocessing.pool:          Process Pools.      (line    6)
* module; multiprocessing.shared_memory: multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line    6)
* module; multiprocessing.sharedctypes:  The multiprocessing sharedctypes module.
                                                             (line    6)
* module; netrc:                         netrc — netrc file processing.
                                                             (line    6)
* module; nis:                           nis — Interface to Sun’s NIS Yellow Pages.
                                                             (line    6)
* module; nntplib:                       nntplib — NNTP protocol client.
                                                             (line    6)
* module; numbers:                       numbers — Numeric abstract base classes.
                                                             (line    6)
* module; operator:                      operator — Standard operators as functions.
                                                             (line    6)
* module; optparse:                      optparse — Parser for command line options.
                                                             (line    6)
* module; os:                            os — Miscellaneous operating system interfaces.
                                                             (line    6)
* module; os.path:                       os path — Common pathname manipulations.
                                                             (line    6)
* module; ossaudiodev:                   ossaudiodev — Access to OSS-compatible audio devices.
                                                             (line    6)
* module; pathlib:                       pathlib — Object-oriented filesystem paths.
                                                             (line    6)
* module; pathlib.types:                 Protocols.          (line    6)
* module; pdb:                           pdb — The Python Debugger.
                                                             (line    6)
* module; pickle:                        pickle — Python object serialization.
                                                             (line    6)
* module; pickletools:                   pickletools — Tools for pickle developers.
                                                             (line    6)
* module; pipes:                         pipes — Interface to shell pipelines.
                                                             (line    6)
* module; pkgutil:                       pkgutil — Package extension utility.
                                                             (line    6)
* module; platform:                      platform — Access to underlying platform’s identifying data.
                                                             (line    6)
* module; plistlib:                      plistlib — Generate and parse Apple plist files.
                                                             (line    6)
* module; poplib:                        poplib — POP3 protocol client.
                                                             (line    6)
* module; posix:                         posix — The most common POSIX system calls.
                                                             (line    6)
* module; pprint:                        pprint — Data pretty printer.
                                                             (line    6)
* module; profile:                       profile and cProfile Module Reference.
                                                             (line    6)
* module; pstats:                        The Stats Class.    (line    9)
* module; pty:                           pty — Pseudo-terminal utilities.
                                                             (line    6)
* module; pwd:                           pwd — The password database.
                                                             (line    6)
* module; py_compile:                    py_compile — Compile Python source files.
                                                             (line    6)
* module; pyclbr:                        pyclbr — Python module browser support.
                                                             (line    6)
* module; pydoc:                         pydoc — Documentation generator and online help system.
                                                             (line    6)
* module; queue:                         queue — A synchronized queue class.
                                                             (line    6)
* module; quopri:                        quopri — Encode and decode MIME quoted-printable data.
                                                             (line    6)
* module; random:                        random — Generate pseudo-random numbers.
                                                             (line    6)
* module; re:                            re — Regular expression operations.
                                                             (line    6)
* module; readline:                      readline — GNU readline interface.
                                                             (line    6)
* module; reprlib:                       reprlib — Alternate repr implementation.
                                                             (line    6)
* module; resource:                      resource — Resource usage information.
                                                             (line    6)
* module; rlcompleter:                   rlcompleter — Completion function for GNU readline.
                                                             (line    6)
* module; runpy:                         runpy — Locating and executing Python modules.
                                                             (line    6)
* module; sched:                         sched — Event scheduler.
                                                             (line    6)
* module; secrets:                       secrets — Generate secure random numbers for managing secrets.
                                                             (line    6)
* module; select:                        select — Waiting for I/O completion.
                                                             (line    6)
* module; selectors:                     selectors — High-level I/O multiplexing.
                                                             (line    6)
* module; shelve:                        shelve — Python object persistence.
                                                             (line    6)
* module; shlex:                         shlex — Simple lexical analysis.
                                                             (line    6)
* module; shutil:                        shutil — High-level file operations.
                                                             (line    6)
* module; signal:                        signal — Set handlers for asynchronous events.
                                                             (line    6)
* module; site:                          site — Site-specific configuration hook.
                                                             (line    6)
* module; sitecustomize:                 sitecustomize.      (line    6)
* module; smtpd:                         smtpd — SMTP Server.
                                                             (line    6)
* module; smtplib:                       smtplib — SMTP protocol client.
                                                             (line    6)
* module; sndhdr:                        sndhdr — Determine type of sound file.
                                                             (line    6)
* module; socket:                        socket — Low-level networking interface.
                                                             (line    6)
* module; socketserver:                  socketserver — A framework for network servers.
                                                             (line    6)
* module; spwd:                          spwd — The shadow password database.
                                                             (line    6)
* module; sqlite3:                       sqlite3 — DB-API 2 0 interface for SQLite databases.
                                                             (line    6)
* module; ssl:                           ssl — TLS/SSL wrapper for socket objects.
                                                             (line    6)
* module; stat:                          stat — Interpreting stat results.
                                                             (line    6)
* module; statistics:                    statistics — Mathematical statistics functions.
                                                             (line    6)
* module; string:                        string — Common string operations.
                                                             (line    6)
* module; string.templatelib:            string templatelib — Support for template string literals.
                                                             (line    6)
* module; stringprep:                    stringprep — Internet String Preparation.
                                                             (line    6)
* module; struct:                        struct — Interpret bytes as packed binary data.
                                                             (line    6)
* module; subprocess:                    subprocess — Subprocess management.
                                                             (line    6)
* module; sunau:                         sunau — Read and write Sun AU files.
                                                             (line    6)
* module; symtable:                      symtable — Access to the compiler’s symbol tables.
                                                             (line    6)
* module; sys:                           sys — System-specific parameters and functions.
                                                             (line    6)
* module; sys.monitoring:                sys monitoring — Execution event monitoring.
                                                             (line    6)
* module; sysconfig:                     sysconfig — Provide access to Python’s configuration information.
                                                             (line    6)
* module; syslog:                        syslog — Unix syslog library routines.
                                                             (line    6)
* module; tabnanny:                      tabnanny — Detection of ambiguous indentation.
                                                             (line    6)
* module; tarfile:                       tarfile — Read and write tar archive files.
                                                             (line    6)
* module; telnetlib:                     telnetlib — Telnet client.
                                                             (line    6)
* module; tempfile:                      tempfile — Generate temporary files and directories.
                                                             (line    6)
* module; termios:                       termios — POSIX style tty control.
                                                             (line    6)
* module; test:                          test — Regression tests package for Python.
                                                             (line    6)
* module; test.regrtest:                 Running tests using the command-line interface.
                                                             (line    6)
* module; test.support:                  test support — Utilities for the Python test suite.
                                                             (line    6)
* module; test.support.bytecode_helper:  test support bytecode_helper — Support tools for testing correct bytecode generation.
                                                             (line    6)
* module; test.support.import_helper:    test support import_helper — Utilities for import tests.
                                                             (line    6)
* module; test.support.os_helper:        test support os_helper — Utilities for os tests.
                                                             (line    6)
* module; test.support.script_helper:    test support script_helper — Utilities for the Python execution tests.
                                                             (line    6)
* module; test.support.socket_helper:    test support socket_helper — Utilities for socket tests.
                                                             (line    6)
* module; test.support.threading_helper: test support threading_helper — Utilities for threading tests.
                                                             (line    6)
* module; test.support.warnings_helper:  test support warnings_helper — Utilities for warnings tests.
                                                             (line    6)
* module; textwrap:                      textwrap — Text wrapping and filling.
                                                             (line    6)
* module; threading:                     threading — Thread-based parallelism.
                                                             (line    6)
* module; time:                          time — Time access and conversions.
                                                             (line    6)
* module; timeit:                        timeit — Measure execution time of small code snippets.
                                                             (line    6)
* module; tkinter:                       tkinter — Python interface to Tcl/Tk.
                                                             (line    6)
* module; tkinter.colorchooser:          tkinter colorchooser — Color choosing dialog.
                                                             (line    6)
* module; tkinter.commondialog:          tkinter commondialog — Dialog window templates.
                                                             (line    6)
* module; tkinter.dnd:                   tkinter dnd — Drag and drop support.
                                                             (line    6)
* module; tkinter.filedialog:            tkinter filedialog — File selection dialogs.
                                                             (line    6)
* module; tkinter.font:                  tkinter font — Tkinter font wrapper.
                                                             (line    6)
* module; tkinter.messagebox:            tkinter messagebox — Tkinter message prompts.
                                                             (line    6)
* module; tkinter.scrolledtext:          tkinter scrolledtext — Scrolled Text Widget.
                                                             (line    6)
* module; tkinter.simpledialog:          tkinter simpledialog — Standard Tkinter input dialogs.
                                                             (line    6)
* module; tkinter.ttk:                   tkinter ttk — Tk themed widgets.
                                                             (line    6)
* module; token:                         token — Constants used with Python parse trees.
                                                             (line    6)
* module; tokenize:                      tokenize — Tokenizer for Python source.
                                                             (line    6)
* module; tomllib:                       tomllib — Parse TOML files.
                                                             (line    6)
* module; trace:                         trace — Trace or track Python statement execution.
                                                             (line    6)
* module; traceback:                     traceback — Print or retrieve a stack traceback.
                                                             (line    6)
* module; tracemalloc:                   tracemalloc — Trace memory allocations.
                                                             (line    6)
* module; tty:                           tty — Terminal control functions.
                                                             (line    6)
* module; turtle:                        turtle — Turtle graphics.
                                                             (line    6)
* module; turtledemo:                    turtledemo — Demo scripts.
                                                             (line    6)
* module; types:                         types — Dynamic type creation and names for built-in types.
                                                             (line    6)
* module; typing:                        typing — Support for type hints.
                                                             (line    6)
* module; unicodedata:                   unicodedata — Unicode Database.
                                                             (line    6)
* module; unittest:                      unittest — Unit testing framework.
                                                             (line    6)
* module; unittest.mock:                 unittest mock — mock object library.
                                                             (line    6)
* module; urllib:                        urllib — URL handling modules.
                                                             (line    6)
* module; urllib.error:                  urllib error — Exception classes raised by urllib request.
                                                             (line    6)
* module; urllib.parse:                  urllib parse — Parse URLs into components.
                                                             (line    6)
* module; urllib.request:                urllib request — Extensible library for opening URLs.
                                                             (line    6)
* module; urllib.response:               urllib response — Response classes used by urllib.
                                                             (line    6)
* module; urllib.robotparser:            urllib robotparser — Parser for robots txt.
                                                             (line    6)
* module; usercustomize:                 usercustomize.      (line    6)
* module; uu:                            uu — Encode and decode uuencode files.
                                                             (line    6)
* module; uuid:                          uuid — UUID objects according to RFC 9562.
                                                             (line    8)
* module; venv:                          venv — Creation of virtual environments.
                                                             (line    6)
* module; warnings:                      warnings — Warning control.
                                                             (line    6)
* module; wave:                          wave — Read and write WAV files.
                                                             (line    6)
* module; weakref:                       weakref — Weak references.
                                                             (line    6)
* module; webbrowser:                    webbrowser — Convenient web-browser controller.
                                                             (line    6)
* module; winreg:                        winreg — Windows registry access.
                                                             (line    6)
* module; winsound:                      winsound — Sound-playing interface for Windows.
                                                             (line    6)
* module; wsgiref:                       wsgiref — WSGI Utilities and Reference Implementation.
                                                             (line    6)
* module; wsgiref.handlers:              wsgiref handlers – server/gateway base classes.
                                                             (line    6)
* module; wsgiref.headers:               wsgiref headers – WSGI response header tools.
                                                             (line    6)
* module; wsgiref.simple_server:         wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line    6)
* module; wsgiref.types:                 wsgiref types – WSGI types for static type checking.
                                                             (line    6)
* module; wsgiref.util:                  wsgiref util – WSGI environment utilities.
                                                             (line    6)
* module; wsgiref.validate:              wsgiref validate — WSGI conformance checker.
                                                             (line    6)
* module; xdrlib:                        xdrlib — Encode and decode XDR data.
                                                             (line    6)
* module; xml:                           XML Processing Modules.
                                                             (line    6)
* module; xml.dom:                       xml dom — The Document Object Model API.
                                                             (line    6)
* module; xml.dom.minidom:               xml dom minidom — Minimal DOM implementation.
                                                             (line    6)
* module; xml.dom.pulldom:               xml dom pulldom — Support for building partial DOM trees.
                                                             (line    6)
* module; xml.etree.ElementInclude:      Functions<9>.       (line    6)
* module; xml.etree.ElementTree:         xml etree ElementTree — The ElementTree XML API.
                                                             (line    6)
* module; xml.parsers.expat:             xml parsers expat — Fast XML parsing using Expat.
                                                             (line    6)
* module; xml.parsers.expat.errors:      Expat error constants.
                                                             (line    6)
* module; xml.parsers.expat.model:       Content Model Descriptions.
                                                             (line    6)
* module; xml.sax:                       xml sax — Support for SAX2 parsers.
                                                             (line    6)
* module; xml.sax.handler:               xml sax handler — Base classes for SAX handlers.
                                                             (line    6)
* module; xml.sax.saxutils:              xml sax saxutils — SAX Utilities.
                                                             (line    6)
* module; xml.sax.xmlreader:             xml sax xmlreader — Interface for XML parsers.
                                                             (line    6)
* module; xmlrpc:                        xmlrpc — XMLRPC server and client modules.
                                                             (line    6)
* module; xmlrpc.client:                 xmlrpc client — XML-RPC client access.
                                                             (line    6)
* module; xmlrpc.server:                 xmlrpc server — Basic XML-RPC servers.
                                                             (line    6)
* module; zipapp:                        zipapp — Manage executable Python zip archives.
                                                             (line    6)
* module; zipfile:                       zipfile — Work with ZIP archives.
                                                             (line    6)
* module; zipimport:                     zipimport — Import modules from Zip archives.
                                                             (line    6)
* module; zlib:                          zlib — Compression compatible with gzip.
                                                             (line    6)
* module; zoneinfo:                      zoneinfo — IANA time zone support.
                                                             (line    6)
* module;__main__:                       Resolution of names.
                                                             (line   54)
* module;__main__ <1>:                   Complete Python programs.
                                                             (line    6)
* module;__main__ <2>:                   Complete Python programs.
                                                             (line   19)
* module;__main__ <3>:                   runpy — Locating and executing Python modules.
                                                             (line   30)
* module;__main__ <4>:                   runpy — Locating and executing Python modules.
                                                             (line  101)
* module;__main__ <5>:                   Embedding Python<2>.
                                                             (line   12)
* module;__main__ <6>:                   Initializing and finalizing the interpreter.
                                                             (line    7)
* module;__main__ <7>:                   Sub-interpreter support.
                                                             (line  112)
* module;__main__ <8>:                   Sub-interpreter support.
                                                             (line  199)
* module;_locale:                        locale — Internationalization services.
                                                             (line   16)
* module;_thread:                        High-level API.     (line   53)
* module;array:                          Mutable sequences.  (line   10)
* module;base64:                         binascii — Convert between binary and ASCII.
                                                             (line    6)
* module;bdb:                            pdb — The Python Debugger.
                                                             (line   17)
* module;builtins:                       Complete Python programs.
                                                             (line    6)
* module;builtins <1>:                   Embedding Python<2>.
                                                             (line   12)
* module;builtins <2>:                   Initializing and finalizing the interpreter.
                                                             (line    7)
* module;builtins <3>:                   Sub-interpreter support.
                                                             (line  112)
* module;builtins <4>:                   Sub-interpreter support.
                                                             (line  199)
* module;cmd:                            pdb — The Python Debugger.
                                                             (line   17)
* module;collections:                    Mutable sequences.  (line   11)
* module;copy:                           copyreg — Register pickle support functions.
                                                             (line    8)
* module;dbm.gnu:                        Dictionaries.       (line   25)
* module;dbm.gnu <1>:                    Restrictions.       (line    6)
* module;dbm.ndbm:                       Dictionaries.       (line   25)
* module;dbm.ndbm <1>:                   Restrictions.       (line    6)
* module;errno:                          Concrete exceptions.
                                                             (line  156)
* module;glob:                           fnmatch — Unix filename pattern matching.
                                                             (line   34)
* module;importing:                      The import statement.
                                                             (line    6)
* module;io:                             I/O objects also known as file objects.
                                                             (line    6)
* module;math:                           Constants<3>.       (line   47)
* module;namespace:                      Modules<2>.         (line   21)
* module;os:                             posix — The most common POSIX system calls.
                                                             (line   14)
* module;pickle:                         copy — Shallow and deep copy operations.
                                                             (line   75)
* module;pickle <1>:                     copyreg — Register pickle support functions.
                                                             (line    8)
* module;pickle <2>:                     shelve — Python object persistence.
                                                             (line    8)
* module;pickle <3>:                     marshal — Internal Python object serialization.
                                                             (line   15)
* module;pty:                            File Descriptor Operations.
                                                             (line  483)
* module;pwd:                            os path — Common pathname manipulations.
                                                             (line  141)
* module;pyexpat:                        xml parsers expat — Fast XML parsing using Expat.
                                                             (line   19)
* module;re:                             fnmatch — Unix filename pattern matching.
                                                             (line    8)
* module;search;path:                    linecache — Random access to text lines.
                                                             (line   30)
* module;search;path <1>:                sys — System-specific parameters and functions.
                                                             (line 1452)
* module;search;path <2>:                site — Site-specific configuration hook.
                                                             (line   14)
* module;search;path <3>:                Embedding Python<2>.
                                                             (line   12)
* module;search;path <4>:                Initializing and finalizing the interpreter.
                                                             (line    7)
* module;search;path <5>:                Process-wide parameters.
                                                             (line  142)
* module;shelve:                         marshal — Internal Python object serialization.
                                                             (line   15)
* module;signal:                         _thread — Low-level threading API.
                                                             (line  195)
* module;signal <1>:                     Signal Handling<2>. (line    7)
* module;signal <2>:                     Signal Handling<2>. (line   34)
* module;signal <3>:                     Signal Handling<2>. (line   44)
* module;socket:                         Internet Protocols and Support.
                                                             (line    6)
* module;stat:                           Files and Directories.
                                                             (line 1119)
* module;struct:                         Socket Objects.     (line  573)
* module;sys:                            except clause.      (line   60)
* module;sys <1>:                        Complete Python programs.
                                                             (line    6)
* module;sys <2>:                        Embedding Python<2>.
                                                             (line   12)
* module;sys <3>:                        Initializing and finalizing the interpreter.
                                                             (line    7)
* module;sys <4>:                        Sub-interpreter support.
                                                             (line  112)
* module;sys <5>:                        Sub-interpreter support.
                                                             (line  199)
* module;urllib.request:                 http client — HTTP protocol client.
                                                             (line    8)
* ModuleFinder (classe in modulefinder): modulefinder — Find modules used by a script.
                                                             (line   26)
* ModuleInfo (classe in pkgutil):        pkgutil — Package extension utility.
                                                             (line   13)
* ModuleNotFoundError:                   Concrete exceptions.
                                                             (line   72)
* modules (in module sys):               Importing Modules<2>.
                                                             (line    9)
* modules (in module sys) <1>:           Initializing and finalizing the interpreter.
                                                             (line    7)
* modules (modulefinder.ModuleFinder attributo): modulefinder — Find modules used by a script.
                                                             (line   49)
* modules (nel modulo sys):              sys — System-specific parameters and functions.
                                                             (line 1425)
* modules_cleanup() (nel modulo test.support.import_helper): test support import_helper — Utilities for import tests.
                                                             (line   71)
* modules_setup() (nel modulo test.support.import_helper): test support import_helper — Utilities for import tests.
                                                             (line   67)
* ModuleSpec (classe in importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line  366)
* ModuleType (classe in types):          Standard Interpreter Types.
                                                             (line  123)
* ModuleType (in module types):          Module Objects.     (line    7)
* modulo:                                Binary arithmetic operations.
                                                             (line   49)
* modulo;array:                          Tipi di sequenze binarie — bytes bytearray memoryview.
                                                             (line    6)
* modulo;builtins:                       La funzione dir.    (line   46)
* modulo;builtins <1>:                   Funzioni Incorporate.
                                                             (line 2289)
* modulo;cerca;percorso:                 Il percorso di ricerca del modulo.
                                                             (line    6)
* modulo;json:                           Salvare dati strutturati con json.
                                                             (line    6)
* modulo;math:                           Tipi Numerici — int float complex.
                                                             (line  117)
* modulo;re:                             Metodi per le Stringhe.
                                                             (line    6)
* modulo;sys:                            Moduli Standard.    (line    6)
* modulo;sys <1>:                        Funzioni Incorporate.
                                                             (line 1539)
* modulo;tipi:                           Oggetti Tipo.       (line    6)
* modulus (sys.hash_info attributo):     sys — System-specific parameters and functions.
                                                             (line 1075)
* MON_1 (nel modulo locale):             locale — Internationalization services.
                                                             (line  250)
* MON_10 (nel modulo locale):            locale — Internationalization services.
                                                             (line  250)
* MON_11 (nel modulo locale):            locale — Internationalization services.
                                                             (line  250)
* MON_12 (nel modulo locale):            locale — Internationalization services.
                                                             (line  250)
* MON_2 (nel modulo locale):             locale — Internationalization services.
                                                             (line  250)
* MON_3 (nel modulo locale):             locale — Internationalization services.
                                                             (line  250)
* MON_4 (nel modulo locale):             locale — Internationalization services.
                                                             (line  250)
* MON_5 (nel modulo locale):             locale — Internationalization services.
                                                             (line  250)
* MON_6 (nel modulo locale):             locale — Internationalization services.
                                                             (line  250)
* MON_7 (nel modulo locale):             locale — Internationalization services.
                                                             (line  250)
* MON_8 (nel modulo locale):             locale — Internationalization services.
                                                             (line  250)
* MON_9 (nel modulo locale):             locale — Internationalization services.
                                                             (line  250)
* MONDAY (nel modulo calendar):          calendar — General calendar-related functions.
                                                             (line  447)
* monotonic_ns() (nel modulo time):      Functions<4>.       (line  208)
* monotonic() (nel modulo time):         Functions<4>.       (line  175)
* month (calendar.IllegalMonthError attributo): calendar — General calendar-related functions.
                                                             (line  523)
* Month (classe in calendar):            calendar — General calendar-related functions.
                                                             (line  508)
* month (datetime.date attributo):       date Objects.       (line  150)
* month (datetime.datetime attributo):   datetime Objects.   (line  309)
* month_abbr (nel modulo calendar):      calendar — General calendar-related functions.
                                                             (line  479)
* month_name (nel modulo calendar):      calendar — General calendar-related functions.
                                                             (line  468)
* month() (nel modulo calendar):         calendar — General calendar-related functions.
                                                             (line  402)
* monthcalendar() (nel modulo calendar): calendar — General calendar-related functions.
                                                             (line  391)
* monthdatescalendar() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line  111)
* monthdays2calendar() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line  117)
* monthdayscalendar() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line  123)
* monthrange() (nel modulo calendar):    calendar — General calendar-related functions.
                                                             (line  386)
* Morsel (classe in http.cookies):       Morsel Objects.     (line    6)
* most_common() (collections.Counter metodo): Counter objects.
                                                             (line   78)
* mouseinterval() (nel modulo curses):   Functions<5>.       (line  308)
* mousemask() (nel modulo curses):       Functions<5>.       (line  315)
* move_into() (pathlib.Path metodo):     Copying moving and deleting.
                                                             (line  100)
* move_to_end() (collections.OrderedDict metodo): OrderedDict objects.
                                                             (line   74)
* move() (curses.panel.Panel metodo):    Panel Objects.      (line   35)
* move() (curses.window metodo):         Window Objects.     (line  405)
* move() (mmap.mmap metodo):             mmap — Memory-mapped file support.
                                                             (line  238)
* move() (nel modulo shutil):            Directory and files operations.
                                                             (line  354)
* move() (pathlib.Path metodo):          Copying moving and deleting.
                                                             (line   83)
* move() (tkinter.ttk.Treeview metodo):  ttk Treeview.       (line  211)
* MozillaCookieJar (classe in http.cookiejar): FileCookieJar subclasses and co-operation with web browsers.
                                                             (line    9)
* MRO:                                   Glossary.           (line 1149)
* mro() (type metodo):                   Special methods.    (line    9)
* msg (http.client.HTTPResponse attributo): HTTPResponse Objects.
                                                             (line   40)
* msg (json.JSONDecodeError attributo):  Exceptions<19>.     (line   11)
* msg (netrc.NetrcParseError attributo): netrc — netrc file processing.
                                                             (line   53)
* msg (re.PatternError attributo):       Exceptions<2>.      (line   15)
* msg (tomllib.TOMLDecodeError attributo): tomllib — Parse TOML files.
                                                             (line   65)
* msg (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line  122)
* mtime (gzip.GzipFile attributo):       gzip — Support for gzip files.
                                                             (line  156)
* mtime (tarfile.TarInfo attributo):     TarInfo Objects.    (line   69)
* mtime() (urllib.robotparser.RobotFileParser metodo): urllib robotparser — Parser for robots txt.
                                                             (line   39)
* mul() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line  132)
* Mult (classe in ast):                  Expressions<2>.     (line   53)
* MultiCall (classe in xmlrpc.client):   MultiCall Objects.  (line    9)
* MULTILINE (nel modulo re):             Flags.              (line   82)
* MultilineContinuationError:            Exceptions<8>.      (line   73)
* multimode() (nel modulo statistics):   Function details.   (line  357)
* MultipartConversionError:              email errors Exception and Defect classes.
                                                             (line   42)
* MultipartInvariantViolationDefect:     email errors Exception and Defect classes.
                                                             (line  116)
* multiplication:                        Binary arithmetic operations.
                                                             (line   16)
* multiply() (decimal.Context metodo):   Context objects.    (line  428)
* mutable:                               Glossary.           (line 1153)
* mutable object:                        Objects values and types.
                                                             (line   10)
* mutable;sequenza;tipi:                 Tipi di Sequenza Mutabili.
                                                             (line    6)
* MutableMapping (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  120)
* MutableMapping (classe in typing):     Aliases to container ABCs in collections abc.
                                                             (line   88)
* MutableSequence (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   68)
* MutableSequence (classe in typing):    Aliases to container ABCs in collections abc.
                                                             (line   96)
* MutableSet (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  115)
* MutableSet (classe in typing):         Aliases to container ABCs in collections abc.
                                                             (line  104)
* mvderwin() (curses.window metodo):     Window Objects.     (line  409)
* mvwin() (curses.window metodo):        Window Objects.     (line  416)
* myrights() (imaplib.IMAP4 metodo):     IMAP4 Objects.      (line  239)
* N_TOKENS (nel modulo token):           token — Constants used with Python parse trees.
                                                             (line  358)
* n_waiting (asyncio.Barrier attributo): Barrier.            (line   98)
* n_waiting (threading.Barrier attributo): Barrier objects.  (line   97)
* NAK (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   88)
* name:                                  Names identifiers and keywords.
                                                             (line    6)
* name <1>:                              Binding of names.   (line    6)
* name <2>:                              Identifiers Names.  (line    6)
* name (AttributeError attributo):       Concrete exceptions.
                                                             (line   22)
* name (bz2.BZ2File attributo):          De compression of files.
                                                             (line  136)
* Name (classe in ast):                  Variables.          (line    6)
* name (codecs.CodecInfo attributo):     codecs — Codec registry and base classes.
                                                             (line   74)
* name (compression.zstd.ZstdFile attributo): Reading and writing compressed files.
                                                             (line  110)
* name (contextvars.ContextVar attributo): Context Variables.
                                                             (line   24)
* name (ctypes.CField attributo):        Structured data types.
                                                             (line  248)
* name (doctest.DocTest attributo):      DocTest Objects.    (line   30)
* name (email.headerregistry.BaseHeader attributo): email headerregistry Custom Header Objects.
                                                             (line   45)
* name (enum.Enum attributo):            Data Types<2>.      (line  125)
* name (gzip.GzipFile attributo):        gzip — Support for gzip files.
                                                             (line  164)
* name (hashlib.hash attributo):         Hash Objects.       (line   19)
* name (hmac.HMAC attributo):            hmac — Keyed-Hashing for Message Authentication.
                                                             (line  104)
* name (http.cookiejar.Cookie attributo): Cookie Objects<2>. (line   28)
* name (ImportError attributo):          Concrete exceptions.
                                                             (line   61)
* name (importlib.abc.FileLoader attributo): importlib abc – Abstract base classes related to import.
                                                             (line  307)
* name (importlib.machinery.AppleFrameworkLoader attributo): importlib machinery – Importers and path hooks.
                                                             (line  502)
* name (importlib.machinery.ExtensionFileLoader attributo): importlib machinery – Importers and path hooks.
                                                             (line  307)
* name (importlib.machinery.ModuleSpec attributo): importlib machinery – Importers and path hooks.
                                                             (line  382)
* name (importlib.machinery.SourceFileLoader attributo): importlib machinery – Importers and path hooks.
                                                             (line  213)
* name (importlib.machinery.SourcelessFileLoader attributo): importlib machinery – Importers and path hooks.
                                                             (line  257)
* name (importlib.resources.abc.Traversable attributo): importlib resources abc – Abstract base classes for resources.
                                                             (line   97)
* name (inspect.Parameter attributo):    Introspecting callables with the Signature object.
                                                             (line  224)
* name (io.FileIO attributo):            Raw File I/O.       (line   60)
* name (logging.Logger attributo):       Logger Objects.     (line   26)
* name (lzma.LZMAFile attributo):        Reading and writing compressed files<2>.
                                                             (line  106)
* name (multiprocessing.Process attributo): Process and exceptions.
                                                             (line  115)
* name (multiprocessing.shared_memory.SharedMemory attributo): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  120)
* name (NameError attributo):            Concrete exceptions.
                                                             (line  126)
* name (nel modulo os):                  os — Miscellaneous operating system interfaces.
                                                             (line   55)
* NAME (nel modulo token):               token — Constants used with Python parse trees.
                                                             (line   45)
* name (os.DirEntry attributo):          Files and Directories.
                                                             (line  945)
* name (pathlib.PurePath attributo):     Methods and properties.
                                                             (line  122)
* name (pyclbr.Class attributo):         Class Objects.      (line   20)
* name (pyclbr.Function attributo):      Function Objects.   (line   19)
* name (sys.thread_info attributo):      sys — System-specific parameters and functions.
                                                             (line 2100)
* name (tarfile.TarInfo attributo):      TarInfo Objects.    (line   61)
* name (tempfile.TemporaryDirectory attributo): tempfile — Generate temporary files and directories.
                                                             (line  194)
* name (threading.Thread attributo):     Thread objects.     (line  180)
* name (traceback.FrameSummary attributo): FrameSummary Objects.
                                                             (line   38)
* name (webbrowser.controller attributo): Browser controller objects.
                                                             (line   10)
* name (xml.dom.Attr attributo):         Attr Objects.       (line    8)
* name (xml.dom.DocumentType attributo): DocumentType Objects.
                                                             (line   33)
* name (zipfile.Path attributo):         Path objects.       (line   31)
* name;binding:                          The import statement.
                                                             (line    6)
* name;binding <1>:                      The import statement.
                                                             (line   52)
* name;binding <2>:                      Function definitions.
                                                             (line    6)
* name;binding <3>:                      Function definitions.
                                                             (line    6)
* name;binding <4>:                      Class definitions.  (line    6)
* name;mangling:                         Identifiers Names.  (line   14)
* name() (nel modulo unicodedata):       unicodedata — Unicode Database.
                                                             (line   40)
* name2codepoint (nel modulo html.entities): html entities — Definitions of HTML general entities.
                                                             (line   30)
* named expression:                      Boolean operations. (line   38)
* Named Shared Memory:                   multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line   10)
* named tuple:                           Glossary.           (line 1162)
* NAMED_FLAGS (enum.EnumCheck attributo): Data Types<2>.     (line  648)
* NamedExpr (classe in ast):             Expressions<2>.     (line  184)
* NamedTemporaryFile() (nel modulo tempfile): tempfile — Generate temporary files and directories.
                                                             (line   74)
* NamedTuple (classe in typing):         Other special directives.
                                                             (line   10)
* namedtuple() (nel modulo collections): namedtuple Factory Function for Tuples with Named Fields.
                                                             (line   11)
* NameError:                             Concrete exceptions.
                                                             (line  118)
* NameError (built-in exception):        Resolution of names.
                                                             (line   16)
* namelist() (zipfile.ZipFile metodo):   ZipFile objects.    (line  131)
* nameprep() (nel modulo encodings.idna): encodings idna — Internationalized Domain Names in Applications.
                                                             (line   50)
* namer (logging.handlers.BaseRotatingHandler attributo): BaseRotatingHandler.
                                                             (line   17)
* namereplace_errors() (nel modulo codecs): Error Handlers.  (line  181)
* namereplace;error handler's name:      Error Handlers.     (line   54)
* names() (nel modulo tkinter.font):     tkinter font — Tkinter font wrapper.
                                                             (line   92)
* namespace:                             Naming and binding. (line    6)
* namespace <1>:                         Glossary.           (line 1189)
* Namespace (classe in argparse):        The Namespace object.
                                                             (line    6)
* Namespace (classe in multiprocessing.managers): Managers.  (line  256)
* namespace package:                     Glossary.           (line 1203)
* NAMESPACE_DNS (nel modulo uuid):       uuid — UUID objects according to RFC 9562.
                                                             (line  276)
* NAMESPACE_OID (nel modulo uuid):       uuid — UUID objects according to RFC 9562.
                                                             (line  285)
* NAMESPACE_URL (nel modulo uuid):       uuid — UUID objects according to RFC 9562.
                                                             (line  281)
* NAMESPACE_X500 (nel modulo uuid):      uuid — UUID objects according to RFC 9562.
                                                             (line  289)
* namespace() (imaplib.IMAP4 metodo):    IMAP4 Objects.      (line  244)
* Namespace() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  195)
* NamespaceErr:                          Exceptions<22>.     (line   66)
* NamespaceLoader (classe in importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line  348)
* namespaceURI (xml.dom.Node attributo): Node Objects.       (line   74)
* nametofont() (nel modulo tkinter.font): tkinter font — Tkinter font wrapper.
                                                             (line   96)
* NaN:                                   Funzioni Incorporate.
                                                             (line  753)
* nan (nel modulo cmath):                Constants<3>.       (line   33)
* nan (nel modulo math):                 Constants<2>.       (line   31)
* nan (sys.hash_info attributo):         sys — System-specific parameters and functions.
                                                             (line 1083)
* nanj (nel modulo cmath):               Constants<3>.       (line   40)
* NannyNag:                              tabnanny — Detection of ambiguous indentation.
                                                             (line   37)
* napms() (nel modulo curses):           Functions<5>.       (line  324)
* nargs (optparse.Option attributo):     Option attributes.  (line   50)
* native code:                           Glossary.           (line 1219)
* native_id (threading.Thread attributo): Thread objects.    (line  213)
* nb_workers (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  223)
* nbytes (memoryview attributo):         Memory Views.       (line  421)
* ncurses_version (nel modulo curses):   Constants<6>.       (line   22)
* ND (inspect.BufferFlags attributo):    Buffer flags.       (line   21)
* ndiff() (nel modulo difflib):          difflib — Helpers for computing deltas.
                                                             (line  233)
* ndim (memoryview attributo):           Memory Views.       (line  488)
* ne() (nel modulo operator):            operator — Standard operators as functions.
                                                             (line   24)
* needs_input (bz2.BZ2Decompressor attributo): Incremental de compression.
                                                             (line   85)
* needs_input (compression.zstd.ZstdDecompressor attributo): Compressing and decompressing data in memory.
                                                             (line  221)
* needs_input (lzma.LZMADecompressor attributo): Compressing and decompressing data in memory<2>.
                                                             (line  175)
* neg() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line  144)
* negation:                              Unary arithmetic and bitwise operations.
                                                             (line   10)
* nested scope:                          Glossary.           (line 1228)
* nested_scopes (nel modulo __future__): Module Contents<5>. (line   14)
* netmask (ipaddress.IPv4Network attributo): Network objects.
                                                             (line  101)
* netmask (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  316)
* NetmaskValueError:                     Custom Exceptions.  (line   13)
* netrc (classe in netrc):               netrc — netrc file processing.
                                                             (line   13)
* NetrcParseError:                       netrc — netrc file processing.
                                                             (line   47)
* netscape (http.cookiejar.CookiePolicy attributo): CookiePolicy Objects.
                                                             (line   68)
* network (ipaddress.IPv4Interface attributo): Interface objects.
                                                             (line   28)
* network (ipaddress.IPv6Interface attributo): Interface objects.
                                                             (line   76)
* network_address (ipaddress.IPv4Network attributo): Network objects.
                                                             (line   86)
* network_address (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  310)
* Never (nel modulo typing):             Special types.      (line   99)
* NEVER_EQ (nel modulo test.support):    test support — Utilities for the Python test suite.
                                                             (line  197)
* new_child() (collections.ChainMap metodo): ChainMap objects.
                                                             (line   46)
* new_class() (nel modulo types):        Dynamic Type Creation.
                                                             (line    6)
* new_event_loop() (asyncio.AbstractEventLoopPolicy metodo): Policy Objects.
                                                             (line   27)
* new_event_loop() (nel modulo asyncio): Event Loop.         (line   71)
* new_panel() (nel modulo curses.panel): Functions<6>.       (line   12)
* new-style class:                       Glossary.           (line 1238)
* new() (nel modulo hashlib):            Constructors.       (line    6)
* new() (nel modulo hmac):               hmac — Keyed-Hashing for Message Authentication.
                                                             (line   15)
* newfunc (C type):                      Slot Type typedefs. (line   31)
* NEWLINE (nel modulo token):            token — Constants used with Python parse trees.
                                                             (line   76)
* NEWLINE token:                         Logical lines.      (line    6)
* NEWLINE token <1>:                     Compound statements.
                                                             (line   55)
* newline universali;metodo bytearray.splitlines: Operazioni su Bytes e Bytearray.
                                                             (line  661)
* newline universali;metodo bytes.splitlines: Operazioni su Bytes e Bytearray.
                                                             (line  661)
* newline universali;metodo str.splitlines: Metodi per le Stringhe.
                                                             (line  715)
* newlines (io.TextIOBase attributo):    Text I/O<2>.        (line   24)
* newpad() (nel modulo curses):          Functions<5>.       (line  328)
* NewType (classe in typing):            Other special directives.
                                                             (line  112)
* newwin() (nel modulo curses):          Functions<5>.       (line  348)
* next (pdb command):                    Debugger commands.  (line  213)
* next_minus() (decimal.Context metodo): Context objects.    (line  432)
* next_minus() (decimal.Decimal metodo): Decimal objects.    (line  416)
* next_plus() (decimal.Context metodo):  Context objects.    (line  436)
* next_plus() (decimal.Decimal metodo):  Decimal objects.    (line  422)
* next_toward() (decimal.Context metodo): Context objects.   (line  440)
* next_toward() (decimal.Decimal metodo): Decimal objects.   (line  428)
* next() (tarfile.TarFile metodo):       TarFile Objects.    (line  132)
* next() (tkinter.ttk.Treeview metodo):  ttk Treeview.       (line  222)
* nextafter() (nel modulo math):         Floating point manipulation functions.
                                                             (line   82)
* nextfile() (nel modulo fileinput):     fileinput — Iterate over lines from multiple input streams.
                                                             (line  121)
* nextkey() (dbm.gnu.gdbm metodo):       dbm gnu — GNU database manager.
                                                             (line  106)
* nextSibling (xml.dom.Node attributo):  Node Objects.       (line   42)
* ngettext() (gettext.GNUTranslations metodo): The GNUTranslations class.
                                                             (line   47)
* ngettext() (gettext.NullTranslations metodo): The NullTranslations class.
                                                             (line   41)
* ngettext() (nel modulo gettext):       GNU gettext API.    (line   44)
* nice() (nel modulo os):                Process Management. (line  358)
* NIL (nel modulo uuid):                 uuid — UUID objects according to RFC 9562.
                                                             (line  317)
* NL (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line   55)
* NL (nel modulo token):                 token — Constants used with Python parse trees.
                                                             (line   80)
* nl_langinfo() (nel modulo locale):     locale — Internationalization services.
                                                             (line  186)
* nl() (nel modulo curses):              Functions<5>.       (line  358)
* nlargest() (nel modulo heapq):         heapq — Heap queue algorithm.
                                                             (line  169)
* nlst() (ftplib.FTP metodo):            FTP objects.        (line  302)
* NO (nel modulo tkinter.messagebox):    tkinter messagebox — Tkinter message prompts.
                                                             (line  159)
* no_animation() (nel modulo turtle):    Animation control.  (line    6)
* no_cache() (zoneinfo.ZoneInfo metodo della classe): The ZoneInfo class.
                                                             (line   44)
* NO_EVENTS (monitoring event):          Events.             (line  105)
* no_proxy:                              urllib request — Extensible library for opening URLs.
                                                             (line  354)
* no_site (sys.flags attributo):         sys — System-specific parameters and functions.
                                                             (line  559)
* no_tracing() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  565)
* no_type_check_decorator() (nel modulo typing): Functions and decorators.
                                                             (line  360)
* no_type_check() (nel modulo typing):   Functions and decorators.
                                                             (line  348)
* no_user_site (sys.flags attributo):    sys — System-specific parameters and functions.
                                                             (line  556)
* NoBoundaryInMultipartDefect:           email errors Exception and Defect classes.
                                                             (line   75)
* nocbreak() (nel modulo curses):        Functions<5>.       (line  364)
* NoDataAllowedErr:                      Exceptions<22>.     (line   83)
* node (uuid.UUID attributo):            uuid — UUID objects according to RFC 9562.
                                                             (line  127)
* node() (nel modulo platform):          Cross platform.     (line   43)
* NoDefault (nel modulo typing):         Introspection helpers.
                                                             (line  197)
* nodelay() (curses.window metodo):      Window Objects.     (line  420)
* nodeName (xml.dom.Node attributo):     Node Objects.       (line   79)
* NodeTransformer (classe in ast):       ast helpers.        (line  224)
* nodeType (xml.dom.Node attributo):     Node Objects.       (line    8)
* nodeValue (xml.dom.Node attributo):    Node Objects.       (line   88)
* NodeVisitor (classe in ast):           ast helpers.        (line  184)
* noecho() (nel modulo curses):          Functions<5>.       (line  369)
* NOEXPR (nel modulo locale):            locale — Internationalization services.
                                                             (line  295)
* NOFLAG (nel modulo re):                Flags.              (line   96)
* nome;offuscamento:                     Variabili Private.  (line   14)
* NoModificationAllowedErr:              Exceptions<22>.     (line   88)
* non-deterministic:                     Glossary.           (line 1246)
* NonCallableMagicMock (classe in unittest.mock): Magic Mock.
                                                             (line   22)
* NonCallableMock (classe in unittest.mock): The Mock Class. (line  582)
* None (Oggetto integrato):              Test del Valore di Verità.
                                                             (line   18)
* None (variabile built-in):             Built-in Constants. (line   18)
* NoneType (nel modulo types):           Standard Interpreter Types.
                                                             (line   19)
* nonl() (nel modulo curses):            Functions<5>.       (line  373)
* Nonlocal (classe in ast):              Function and class definitions.
                                                             (line  145)
* nonmember() (nel modulo enum):         Utilities and Decorators.
                                                             (line   86)
* noop() (imaplib.IMAP4 metodo):         IMAP4 Objects.      (line  248)
* noop() (poplib.POP3 metodo):           POP3 Objects.       (line   79)
* NoOptionError:                         Exceptions<8>.      (line   32)
* NOP (opcode):                          Python Bytecode Instructions.
                                                             (line  134)
* noqiflush() (nel modulo curses):       Functions<5>.       (line  383)
* noraw() (nel modulo curses):           Functions<5>.       (line  391)
* NoReturn (nel modulo typing):          Special types.      (line   99)
* NORMAL (nel modulo tkinter.font):      tkinter font — Tkinter font wrapper.
                                                             (line   15)
* NORMAL_PRIORITY_CLASS (nel modulo subprocess): Windows Constants.
                                                             (line   96)
* NormalDist (classe in statistics):     NormalDist objects. (line   13)
* normalize_encoding() (nel modulo encodings): encodings — Encodings package.
                                                             (line    8)
* NORMALIZE_WHITESPACE (nel modulo doctest): Option Flags.   (line   37)
* normalize() (decimal.Context metodo):  Context objects.    (line  444)
* normalize() (decimal.Decimal metodo):  Decimal objects.    (line  436)
* normalize() (nel modulo locale):       locale — Internationalization services.
                                                             (line  446)
* normalize() (nel modulo unicodedata):  unicodedata — Unicode Database.
                                                             (line  133)
* normalize() (xml.dom.Node metodo):     Node Objects.       (line  141)
* normalvariate() (nel modulo random):   Real-valued distributions.
                                                             (line   85)
* normcase() (nel modulo os.path):       os path — Common pathname manipulations.
                                                             (line  350)
* normpath() (nel modulo os.path):       os path — Common pathname manipulations.
                                                             (line  359)
* NoSectionError:                        Exceptions<8>.      (line   10)
* NoSuchMailboxError:                    Exceptions<20>.     (line   12)
* Not (classe in ast):                   Expressions<2>.     (line   27)
* not_() (nel modulo operator):          operator — Standard operators as functions.
                                                             (line   49)
* NOT_TAKEN (opcode):                    Python Bytecode Instructions.
                                                             (line  139)
* NotADirectoryError:                    OS exceptions.      (line   89)
* notation:                              Notation.           (line    6)
* notationDecl() (xml.sax.handler.DTDHandler metodo): DTDHandler Objects.
                                                             (line    8)
* NotationDeclHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  363)
* notations (xml.dom.DocumentType attributo): DocumentType Objects.
                                                             (line   46)
* NotConnected:                          http client — HTTP protocol client.
                                                             (line  137)
* Notebook (classe in tkinter.ttk):      ttk Notebook.       (line    6)
* NotEmptyError:                         Exceptions<20>.     (line   19)
* NotEq (classe in ast):                 Expressions<2>.     (line  108)
* NOTEQUAL (nel modulo token):           token — Constants used with Python parse trees.
                                                             (line  275)
* NotFoundErr:                           Exceptions<22>.     (line   72)
* notify_all() (asyncio.Condition metodo): Condition.        (line   67)
* notify_all() (threading.Condition metodo): Condition objects.
                                                             (line  180)
* notify() (asyncio.Condition metodo):   Condition.          (line   54)
* notify() (threading.Condition metodo): Condition objects.  (line  160)
* notimeout() (curses.window metodo):    Window Objects.     (line  424)
* NotImplemented (variabile built-in):   Built-in Constants. (line   25)
* NotImplementedError:                   Concrete exceptions.
                                                             (line  133)
* NotImplementedType (nel modulo types): Standard Interpreter Types.
                                                             (line  103)
* NotIn (classe in ast):                 Expressions<2>.     (line  108)
* NotRequired (nel modulo typing):       Special forms.      (line  267)
* NOTSET (nel modulo logging):           Logging Levels.     (line   16)
* NotShareableError:                     Exceptions<12>.     (line   26)
* NotStandaloneHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  414)
* NotSupportedErr:                       Exceptions<22>.     (line   78)
* NotSupportedError:                     Exceptions<6>.      (line   85)
* noutrefresh() (curses.window metodo):  Window Objects.     (line  432)
* NOVEMBER (nel modulo calendar):        calendar — General calendar-related functions.
                                                             (line  490)
* now() (datetime.datetime metodo della classe): datetime Objects.
                                                             (line   61)
* npgettext() (gettext.GNUTranslations metodo): The GNUTranslations class.
                                                             (line   79)
* npgettext() (gettext.NullTranslations metodo): The NullTranslations class.
                                                             (line   55)
* npgettext() (nel modulo gettext):      GNU gettext API.    (line   67)
* NSIG (nel modulo signal):              Module contents<2>. (line  236)
* nsmallest() (nel modulo heapq):        heapq — Heap queue algorithm.
                                                             (line  177)
* NTEventLogHandler (classe in logging.handlers): NTEventLogHandler.
                                                             (line   11)
* ntohl() (nel modulo socket):           Other functions<2>. (line  225)
* ntohs() (nel modulo socket):           Other functions<2>. (line  232)
* ntransfercmd() (ftplib.FTP metodo):    FTP objects.        (line  279)
* NUL (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   19)
* null;operation:                        The pass statement. (line    6)
* null;operation <1>:                    The pass statement. (line    6)
* nullcontext() (nel modulo contextlib): Utilities.          (line  220)
* NullHandler (classe in logging):       NullHandler.        (line   12)
* NullTranslations (classe in gettext):  The NullTranslations class.
                                                             (line   13)
* num_addresses (ipaddress.IPv4Network attributo): Network objects.
                                                             (line  128)
* num_addresses (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  328)
* num_tickets (ssl.SSLContext attributo): SSL Contexts.      (line  564)
* number:                                Numeric literals.   (line    6)
* Number (classe in numbers):            numbers — Numeric abstract base classes.
                                                             (line   15)
* NUMBER (nel modulo token):             token — Constants used with Python parse trees.
                                                             (line   50)
* number_class() (decimal.Context metodo): Context objects.  (line  448)
* number_class() (decimal.Decimal metodo): Decimal objects.  (line  459)
* numerator (fractions.Fraction attributo): fractions — Rational numbers.
                                                             (line  117)
* numerator (numbers.Rational attributo): The numeric tower. (line   51)
* numeric literal:                       Numeric literals.   (line    6)
* numeric() (nel modulo unicodedata):    unicodedata — Unicode Database.
                                                             (line   71)
* numerico;conversioni:                  Tipi Numerici — int float complex.
                                                             (line  117)
* numerico;letterali:                    Tipi Numerici — int float complex.
                                                             (line   19)
* numero complesso;letterali:            Tipi Numerici — int float complex.
                                                             (line   19)
* numinput() (nel modulo turtle):        Input methods.      (line   22)
* O_APPEND (nel modulo os):              File Descriptor Operations.
                                                             (line  421)
* O_ASYNC (nel modulo os):               File Descriptor Operations.
                                                             (line  464)
* O_BINARY (nel modulo os):              File Descriptor Operations.
                                                             (line  443)
* O_CLOEXEC (nel modulo os):             File Descriptor Operations.
                                                             (line  431)
* O_CREAT (nel modulo os):               File Descriptor Operations.
                                                             (line  421)
* O_DIRECT (nel modulo os):              File Descriptor Operations.
                                                             (line  464)
* O_DIRECTORY (nel modulo os):           File Descriptor Operations.
                                                             (line  464)
* O_DSYNC (nel modulo os):               File Descriptor Operations.
                                                             (line  431)
* O_EVTONLY (nel modulo os):             File Descriptor Operations.
                                                             (line  453)
* O_EXCL (nel modulo os):                File Descriptor Operations.
                                                             (line  421)
* O_EXLOCK (nel modulo os):              File Descriptor Operations.
                                                             (line  464)
* O_FSYNC (nel modulo os):               File Descriptor Operations.
                                                             (line  453)
* O_NDELAY (nel modulo os):              File Descriptor Operations.
                                                             (line  431)
* O_NOATIME (nel modulo os):             File Descriptor Operations.
                                                             (line  464)
* O_NOCTTY (nel modulo os):              File Descriptor Operations.
                                                             (line  431)
* O_NOFOLLOW (nel modulo os):            File Descriptor Operations.
                                                             (line  464)
* O_NOFOLLOW_ANY (nel modulo os):        File Descriptor Operations.
                                                             (line  453)
* O_NOINHERIT (nel modulo os):           File Descriptor Operations.
                                                             (line  443)
* O_NONBLOCK (nel modulo os):            File Descriptor Operations.
                                                             (line  431)
* O_PATH (nel modulo os):                File Descriptor Operations.
                                                             (line  464)
* O_RANDOM (nel modulo os):              File Descriptor Operations.
                                                             (line  443)
* O_RDONLY (nel modulo os):              File Descriptor Operations.
                                                             (line  421)
* O_RDWR (nel modulo os):                File Descriptor Operations.
                                                             (line  421)
* O_RSYNC (nel modulo os):               File Descriptor Operations.
                                                             (line  431)
* O_SEQUENTIAL (nel modulo os):          File Descriptor Operations.
                                                             (line  443)
* O_SHLOCK (nel modulo os):              File Descriptor Operations.
                                                             (line  464)
* O_SHORT_LIVED (nel modulo os):         File Descriptor Operations.
                                                             (line  443)
* O_SYMLINK (nel modulo os):             File Descriptor Operations.
                                                             (line  453)
* O_SYNC (nel modulo os):                File Descriptor Operations.
                                                             (line  431)
* O_TEMPORARY (nel modulo os):           File Descriptor Operations.
                                                             (line  443)
* O_TEXT (nel modulo os):                File Descriptor Operations.
                                                             (line  443)
* O_TMPFILE (nel modulo os):             File Descriptor Operations.
                                                             (line  464)
* O_TRUNC (nel modulo os):               File Descriptor Operations.
                                                             (line  421)
* O_WRONLY (nel modulo os):              File Descriptor Operations.
                                                             (line  421)
* obj (AttributeError attributo):        Concrete exceptions.
                                                             (line   26)
* obj (memoryview attributo):            Memory Views.       (line  410)
* object:                                Objects values and types.
                                                             (line    6)
* object <1>:                            Glossary.           (line 1256)
* object (classe built-in):              Funzioni Incorporate.
                                                             (line 1296)
* object (UnicodeError attributo):       Concrete exceptions.
                                                             (line  459)
* object; PickleBuffer:                  MemoryView objects. (line   84)
* object;asynchronous-generator:         Asynchronous generator functions<2>.
                                                             (line   66)
* object;Boolean:                        numbers Integral.   (line   27)
* object;built-in function:              Built-in functions. (line    6)
* object;built-in function <1>:          Calls.              (line  143)
* object;built-in method:                Built-in methods.   (line    6)
* object;built-in method <1>:            Calls.              (line  143)
* object;bytearray:                      Byte Array Objects. (line    6)
* object;bytes:                          Bytes Objects.      (line    9)
* object;callable:                       Callable types.     (line    6)
* object;callable <1>:                   Slicings.           (line   39)
* object;Capsule:                        Capsules<2>.        (line    6)
* object;class:                          Custom classes.     (line   19)
* object;class <1>:                      Calls.              (line  149)
* object;class <2>:                      Class definitions.  (line    6)
* object;class instance:                 Custom classes.     (line   19)
* object;class instance <1>:             Class instances.    (line    6)
* object;class instance <2>:             Calls.              (line  153)
* object;code:                           Code objects.       (line    6)
* object;code <1>:                       marshal — Internal Python object serialization.
                                                             (line   37)
* object;code <2>:                       Cell Objects.       (line   59)
* object;complex:                        numbers Complex complex.
                                                             (line    6)
* object;complex number:                 Complex Number Objects.
                                                             (line    6)
* object;deallocation:                   Finalization and De-allocation.
                                                             (line    6)
* object;dictionary:                     Dictionaries.       (line    6)
* object;dictionary <1>:                 Custom classes.     (line   19)
* object;dictionary <2>:                 Basic customization.
                                                             (line  242)
* object;dictionary <3>:                 Dictionary displays.
                                                             (line    6)
* object;dictionary <4>:                 Subscriptions.      (line    6)
* object;dictionary <5>:                 Assignment statements.
                                                             (line  115)
* object;dictionary <6>:                 Dictionary Objects. (line    6)
* object;Ellipsis:                       Ellipsis.           (line    6)
* object;file:                           File Objects.       (line    6)
* object;finalization:                   Finalization and De-allocation.
                                                             (line    6)
* object;floating-point:                 numbers Real float. (line    6)
* object;floating-point <1>:             Floating-Point Objects.
                                                             (line    6)
* object;frame:                          Frame objects.      (line    6)
* object;frozenset:                      Set types.          (line   29)
* object;frozenset <1>:                  Set Objects.        (line    6)
* object;function:                       User-defined functions.
                                                             (line    6)
* object;function <1>:                   Built-in functions. (line    6)
* object;function <2>:                   Calls.              (line  132)
* object;function <3>:                   Calls.              (line  143)
* object;function <4>:                   Function definitions.
                                                             (line    6)
* object;function <5>:                   Function Objects<3>.
                                                             (line    6)
* object;generator:                      Special read-only attributes<2>.
                                                             (line   89)
* object;generator <1>:                  Generator expressions.
                                                             (line    6)
* object;generator <2>:                  Yield expressions.  (line  110)
* object;immutable:                      Immutable sequences.
                                                             (line    6)
* object;immutable sequence:             Immutable sequences.
                                                             (line    6)
* object;instance:                       Custom classes.     (line   19)
* object;instance <1>:                   Class instances.    (line    6)
* object;instance <2>:                   Calls.              (line  153)
* object;instancemethod:                 Instance Method Objects.
                                                             (line    6)
* object;integer:                        numbers Integral.   (line    6)
* object;integer <1>:                    Integer Objects.    (line    6)
* object;list:                           Mutable sequences.  (line   18)
* object;list <1>:                       List displays.      (line    6)
* object;list <2>:                       Attribute references.
                                                             (line   10)
* object;list <3>:                       Subscriptions.      (line    6)
* object;list <4>:                       Slicings.           (line    6)
* object;list <5>:                       Assignment statements.
                                                             (line  106)
* object;list <6>:                       List Objects.       (line    6)
* object;long integer:                   Integer Objects.    (line    6)
* object;mapping:                        Mappings.           (line    6)
* object;mapping <1>:                    Class instances.    (line   26)
* object;mapping <2>:                    Subscriptions.      (line    6)
* object;mapping <3>:                    Assignment statements.
                                                             (line  115)
* object;mapping <4>:                    Container Objects.  (line    6)
* object;memoryview:                     Ellipsis Object.    (line   19)
* object;method:                         Instance methods.   (line    6)
* object;method <1>:                     Built-in methods.   (line    6)
* object;method <2>:                     Calls.              (line  143)
* object;method <3>:                     Method Objects.     (line    6)
* object;module:                         Modules<2>.         (line    6)
* object;module <1>:                     Attribute references.
                                                             (line   10)
* object;module <2>:                     Module Objects.     (line    6)
* object;mutable:                        Mutable sequences.  (line    6)
* object;mutable <1>:                    Assignment statements.
                                                             (line    6)
* object;mutable <2>:                    Assignment statements.
                                                             (line  101)
* object;mutable sequence:               Mutable sequences.  (line    6)
* object;None:                           None.               (line    6)
* object;None <1>:                       Expression statements.
                                                             (line   17)
* object;None <2>:                       The None Object.    (line    6)
* object;NotImplemented:                 NotImplemented.     (line    6)
* object;numeric:                        numbers Number.     (line    6)
* object;numeric <1>:                    Class instances.    (line   26)
* object;numeric <2>:                    Numeric Objects.    (line    6)
* object;sequence:                       Sequences.          (line    6)
* object;sequence <1>:                   Class instances.    (line   26)
* object;sequence <2>:                   Subscriptions.      (line    6)
* object;sequence <3>:                   Slicings.           (line    6)
* object;sequence <4>:                   Membership test operations.
                                                             (line   36)
* object;sequence <5>:                   Assignment statements.
                                                             (line  106)
* object;sequence <6>:                   The for statement.  (line    6)
* object;sequence <7>:                   Sequence Objects.   (line    6)
* object;set:                            Set types.          (line   23)
* object;set <1>:                        Set displays.       (line    6)
* object;set <2>:                        Set Objects.        (line    6)
* object;set type:                       Set types.          (line    6)
* object;slice:                          Emulating container types.
                                                             (line   71)
* object;socket:                         socket — Low-level networking interface.
                                                             (line   22)
* object;string:                         Subscriptions.      (line    6)
* object;string <1>:                     Slicings.           (line    6)
* object;traceback:                      Traceback objects.  (line    6)
* object;traceback <1>:                  The raise statement.
                                                             (line   21)
* object;traceback <2>:                  except clause.      (line   60)
* object;traceback <3>:                  sys — System-specific parameters and functions.
                                                             (line  459)
* object;traceback <4>:                  traceback — Print or retrieve a stack traceback.
                                                             (line   19)
* object;tuple:                          Immutable sequences.
                                                             (line   29)
* object;tuple <1>:                      Subscriptions.      (line    6)
* object;tuple <2>:                      Slicings.           (line    6)
* object;tuple <3>:                      Expression lists.   (line   13)
* object;tuple <4>:                      Tuple Objects.      (line    6)
* object;type:                           Objects Types and Reference Counts.
                                                             (line    6)
* object;type <1>:                       Type Objects.       (line    6)
* object;user-defined function:          User-defined functions.
                                                             (line    6)
* object;user-defined function <1>:      Calls.              (line  132)
* object;user-defined function <2>:      Function definitions.
                                                             (line    6)
* object;user-defined method:            Instance methods.   (line    6)
* object.__match_args__ (variabile built-in): Customizing positional arguments in class pattern matching.
                                                             (line   12)
* object.__slots__ (variabile built-in): __slots__<2>.       (line   14)
* objobjargproc (C type):                Slot Type typedefs. (line  136)
* objobjproc (C type):                   Slot Type typedefs. (line  132)
* octal literal:                         Numeric literals.   (line    6)
* octdigits (nel modulo string):         String constants.   (line   32)
* OCTOBER (nel modulo calendar):         calendar — General calendar-related functions.
                                                             (line  490)
* offset (ctypes.CField attributo):      Structured data types.
                                                             (line  256)
* offset (SyntaxError attributo):        Concrete exceptions.
                                                             (line  333)
* offset (tarfile.TarInfo attributo):    TarInfo Objects.    (line  149)
* offset (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line  110)
* offset (xml.parsers.expat.ExpatError attributo): ExpatError Exceptions.
                                                             (line   32)
* offset_data (tarfile.TarInfo attributo): TarInfo Objects.  (line  153)
* oggetti;confrontare:                   Confronti.          (line   44)
* oggetto codice:                        Metodi.             (line   45)
* oggetto file;open() funzione incorporata: Funzioni Incorporate.
                                                             (line 1331)
* oggetto;Booleano:                      Tipi Numerici — int float complex.
                                                             (line    6)
* oggetto;bytearray:                     Tipi di Sequenza Mutabili.
                                                             (line    6)
* oggetto;bytearray <1>:                 Tipi di sequenze binarie — bytes bytearray memoryview.
                                                             (line    6)
* oggetto;bytearray <2>:                 Oggetti Bytearray.  (line    6)
* oggetto;bytes:                         Tipi di sequenze binarie — bytes bytearray memoryview.
                                                             (line    6)
* oggetto;bytes <1>:                     Oggetti bytes.      (line    6)
* oggetto;codice:                        Metodi.             (line   46)
* oggetto;dizionario:                    Tipi di Mapping — dict.
                                                             (line    6)
* oggetto;file:                          Lettura e Scrittura di File.
                                                             (line    6)
* oggetto;floating-point:                Tipi Numerici — int float complex.
                                                             (line    6)
* oggetto;GenericAlias:                  Tipo Generic Alias. (line    6)
* oggetto;intero:                        Tipi Numerici — int float complex.
                                                             (line    6)
* oggetto;io.StringIO:                   Tipo Sequenza di Testo — str.
                                                             (line   39)
* oggetto;list:                          Tipi di Sequenza Mutabili.
                                                             (line    6)
* oggetto;list <1>:                      Liste<2>.           (line    6)
* oggetto;mapping:                       Tipi di Mapping — dict.
                                                             (line    6)
* oggetto;memoryview:                    Tipi di sequenze binarie — bytes bytearray memoryview.
                                                             (line    6)
* oggetto;metodo:                        Oggetti Istanza.    (line   26)
* oggetto;metodo <1>:                    Metodi.             (line    6)
* oggetto;numerico:                      Confronti.          (line   44)
* oggetto;numerico <1>:                  Tipi Numerici — int float complex.
                                                             (line    6)
* oggetto;numero complesso:              Tipi Numerici — int float complex.
                                                             (line    6)
* oggetto;range:                         Intervalli.         (line    6)
* oggetto;sequenza:                      Operazioni Comuni sulle Sequenze.
                                                             (line    6)
* oggetto;set:                           Tipi di Insiemi — set frozenset.
                                                             (line    6)
* oggetto;stringa:                       Intervalli.         (line  129)
* oggetto;tipo:                          Funzioni Incorporate.
                                                             (line 2119)
* oggetto;tupla:                         Tipi di Sequenza Immutabili.
                                                             (line    6)
* oggetto;tupla <1>:                     Tuple.              (line    6)
* oggetto;Union:                         Tipo Unione.        (line    6)
* OK (nel modulo curses):                Constants<6>.       (line   13)
* OK (nel modulo tkinter.messagebox):    tkinter messagebox — Tkinter message prompts.
                                                             (line  153)
* ok_command() (tkinter.filedialog.LoadFileDialog metodo): Native Load/Save Dialogs.
                                                             (line  140)
* ok_command() (tkinter.filedialog.SaveFileDialog metodo): Native Load/Save Dialogs.
                                                             (line  150)
* ok_event() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line  119)
* OKCANCEL (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  171)
* old_value (contextvars.Token attributo): Context Variables.
                                                             (line  123)
* OleDLL (classe in ctypes):             Loading shared libraries.
                                                             (line   35)
* on_motion() (tkinter.dnd.DndHandler metodo): tkinter dnd — Drag and drop support.
                                                             (line   56)
* on_release() (tkinter.dnd.DndHandler metodo): tkinter dnd — Drag and drop support.
                                                             (line   61)
* onclick() (nel modulo turtle):         Using screen events.
                                                             (line   56)
* ondrag() (nel modulo turtle):          Using events.       (line   57)
* onecmd() (cmd.Cmd metodo):             Cmd Objects.        (line   59)
* onkey() (nel modulo turtle):           Using screen events.
                                                             (line   12)
* onkeypress() (nel modulo turtle):      Using screen events.
                                                             (line   35)
* onkeyrelease() (nel modulo turtle):    Using screen events.
                                                             (line   12)
* onrelease() (nel modulo turtle):       Using events.       (line   30)
* onscreenclick() (nel modulo turtle):   Using screen events.
                                                             (line   56)
* ontimer() (nel modulo turtle):         Using screen events.
                                                             (line   86)
* OP (nel modulo token):                 token — Constants used with Python parse trees.
                                                             (line   62)
* OP_ALL (nel modulo ssl):               Constants<9>.       (line  211)
* OP_CIPHER_SERVER_PREFERENCE (nel modulo ssl): Constants<9>.
                                                             (line  300)
* OP_ENABLE_KTLS (nel modulo ssl):       Constants<9>.       (line  358)
* OP_ENABLE_MIDDLEBOX_COMPAT (nel modulo ssl): Constants<9>. (line  324)
* OP_IGNORE_UNEXPECTED_EOF (nel modulo ssl): Constants<9>.   (line  350)
* OP_LEGACY_SERVER_CONNECT (nel modulo ssl): Constants<9>.   (line  375)
* OP_NO_COMPRESSION (nel modulo ssl):    Constants<9>.       (line  333)
* OP_NO_RENEGOTIATION (nel modulo ssl):  Constants<9>.       (line  290)
* OP_NO_SSLv2 (nel modulo ssl):          Constants<9>.       (line  219)
* OP_NO_SSLv3 (nel modulo ssl):          Constants<9>.       (line  229)
* OP_NO_TICKET (nel modulo ssl):         Constants<9>.       (line  344)
* OP_NO_TLSv1 (nel modulo ssl):          Constants<9>.       (line  239)
* OP_NO_TLSv1_1 (nel modulo ssl):        Constants<9>.       (line  251)
* OP_NO_TLSv1_2 (nel modulo ssl):        Constants<9>.       (line  263)
* OP_NO_TLSv1_3 (nel modulo ssl):        Constants<9>.       (line  275)
* OP_SINGLE_DH_USE (nel modulo ssl):     Constants<9>.       (line  308)
* OP_SINGLE_ECDH_USE (nel modulo ssl):   Constants<9>.       (line  316)
* Open (classe in tkinter.filedialog):   Native Load/Save Dialogs.
                                                             (line   60)
* open_binary() (nel modulo importlib.resources): Functional API.
                                                             (line   35)
* open_code() (nel modulo io):           High-level Module Interface.
                                                             (line   22)
* open_connection() (nel modulo asyncio): Streams.           (line   42)
* open_flags (nel modulo dbm.gnu):       dbm gnu — GNU database manager.
                                                             (line   28)
* open_new_tab() (nel modulo webbrowser): Command-line interface<6>.
                                                             (line   60)
* open_new_tab() (webbrowser.controller metodo): Browser controller objects.
                                                             (line   26)
* open_new() (nel modulo webbrowser):    Command-line interface<6>.
                                                             (line   52)
* open_new() (webbrowser.controller metodo): Browser controller objects.
                                                             (line   20)
* open_osfhandle() (nel modulo msvcrt):  File Operations.    (line   44)
* open_resource() (importlib.resources.abc.ResourceReader metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line   47)
* open_text() (nel modulo importlib.resources): Functional API.
                                                             (line   51)
* open_unix_connection() (nel modulo asyncio): Streams.      (line  118)
* open_urlresource() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  616)
* open() (imaplib.IMAP4 metodo):         IMAP4 Objects.      (line  252)
* open() (importlib.resources.abc.Traversable metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line  144)
* open() (nel modulo bz2):               De compression of files.
                                                             (line    6)
* open() (nel modulo codecs):            codecs — Codec registry and base classes.
                                                             (line  182)
* open() (nel modulo compression.zstd):  Reading and writing compressed files.
                                                             (line    6)
* open() (nel modulo dbm.dumb):          dbm dumb — Portable DBM implementation.
                                                             (line   29)
* open() (nel modulo dbm.gnu):           dbm gnu — GNU database manager.
                                                             (line   33)
* open() (nel modulo dbm.ndbm):          dbm ndbm — New Database Manager.
                                                             (line   38)
* open() (nel modulo dbm.sqlite3):       dbm sqlite3 — SQLite backend for dbm.
                                                             (line   22)
* open() (nel modulo dbm):               dbm — Interfaces to Unix «databases».
                                                             (line   49)
* open() (nel modulo gzip):              gzip — Support for gzip files.
                                                             (line   33)
* open() (nel modulo io):                High-level Module Interface.
                                                             (line   12)
* open() (nel modulo lzma):              Reading and writing compressed files<2>.
                                                             (line    6)
* open() (nel modulo os):                File Descriptor Operations.
                                                             (line  376)
* open() (nel modulo shelve):            shelve — Python object persistence.
                                                             (line   17)
* open() (nel modulo tarfile):           tarfile — Read and write tar archive files.
                                                             (line   55)
* open() (nel modulo tokenize):          Tokenizing Input.   (line   99)
* open() (nel modulo wave):              wave — Read and write WAV files.
                                                             (line   21)
* open() (nel modulo webbrowser):        Command-line interface<6>.
                                                             (line   32)
* open() (pathlib.Path metodo):          Reading and writing files.
                                                             (line    6)
* open() (tarfile.TarFile metodo della classe): TarFile Objects.
                                                             (line   98)
* open() (urllib.request.OpenerDirector metodo): OpenerDirector Objects.
                                                             (line   46)
* open() (webbrowser.controller metodo): Browser controller objects.
                                                             (line   14)
* open() (zipfile.Path metodo):          Path objects.       (line   35)
* open() (zipfile.ZipFile metodo):       ZipFile objects.    (line  135)
* OpenerDirector (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  317)
* OpenKey() (nel modulo winreg):         Functions<13>.      (line  286)
* OpenKeyEx() (nel modulo winreg):       Functions<13>.      (line  286)
* openlog() (nel modulo syslog):         syslog — Unix syslog library routines.
                                                             (line   51)
* openpty() (nel modulo os):             File Descriptor Operations.
                                                             (line  481)
* openpty() (nel modulo pty):            pty — Pseudo-terminal utilities.
                                                             (line   35)
* OPENSSL_VERSION (nel modulo ssl):      Constants<9>.       (line  485)
* OPENSSL_VERSION_INFO (nel modulo ssl): Constants<9>.       (line  495)
* OPENSSL_VERSION_NUMBER (nel modulo ssl): Constants<9>.     (line  505)
* OpenSSL;(use in module hashlib):       Hash algorithms.    (line   18)
* OpenSSL;(use in module ssl):           ssl — TLS/SSL wrapper for socket objects.
                                                             (line    8)
* OperationalError:                      Exceptions<6>.      (line   57)
* operator;- (minus):                    Unary arithmetic and bitwise operations.
                                                             (line   10)
* operator;- (minus) <1>:                Binary arithmetic operations.
                                                             (line   89)
* operator;!=:                           Comparisons.        (line    6)
* operator;@ (at):                       Binary arithmetic operations.
                                                             (line   29)
* operator;* (asterisk):                 Binary arithmetic operations.
                                                             (line   16)
* operator;**:                           The power operator. (line    6)
* operator;/ (slash):                    Binary arithmetic operations.
                                                             (line   37)
* operator;//:                           Binary arithmetic operations.
                                                             (line   37)
* operator;& (ampersand):                Binary bitwise operations.
                                                             (line   12)
* operator;% (percent):                  Binary arithmetic operations.
                                                             (line   49)
* operator;^ (caret):                    Binary bitwise operations.
                                                             (line   16)
* operator;+ (plus):                     Unary arithmetic and bitwise operations.
                                                             (line   14)
* operator;+ (plus) <1>:                 Binary arithmetic operations.
                                                             (line   77)
* operator;< (less):                     Comparisons.        (line    6)
* operator;<<:                           Shifting operations.
                                                             (line    6)
* operator;<=:                           Comparisons.        (line    6)
* operator;==:                           Comparisons.        (line    6)
* operator;> (greater):                  Comparisons.        (line    6)
* operator;>=:                           Comparisons.        (line    6)
* operator;>>:                           Shifting operations.
                                                             (line    6)
* operator;| (vertical bar):             Binary bitwise operations.
                                                             (line   20)
* operator;~ (tilde):                    Unary arithmetic and bitwise operations.
                                                             (line   18)
* operator;and:                          Boolean operations. (line   21)
* operator;in:                           Membership test operations.
                                                             (line   36)
* operator;is:                           Membership test operations.
                                                             (line   39)
* operator;is not:                       Membership test operations.
                                                             (line   39)
* operator;not:                          Boolean operations. (line   18)
* operator;not in:                       Membership test operations.
                                                             (line   36)
* operator;or:                           Boolean operations. (line   25)
* operator;overloading:                  Special method names.
                                                             (line    6)
* operator;precedence:                   Operator precedence.
                                                             (line    6)
* operatore;- (meno):                    Tipi Numerici — int float complex.
                                                             (line   30)
* operatore;!=:                          Confronti.          (line    6)
* operatore;* (asterisco):               Tipi Numerici — int float complex.
                                                             (line   30)
* operatore;**:                          Tipi Numerici — int float complex.
                                                             (line   30)
* operatore;/ (barra):                   Tipi Numerici — int float complex.
                                                             (line   30)
* operatore;//:                          Tipi Numerici — int float complex.
                                                             (line   30)
* operatore;& (e commerciale):           Operazioni Bitwise sui Tipi Integer.
                                                             (line    6)
* operatore;% (percento):                Tipi Numerici — int float complex.
                                                             (line   30)
* operatore;^ (circonflesso):            Operazioni Bitwise sui Tipi Integer.
                                                             (line    6)
* operatore;+ (più):                     Tipi Numerici — int float complex.
                                                             (line   30)
* operatore;< (minore):                  Confronti.          (line    6)
* operatore;<<:                          Operazioni Bitwise sui Tipi Integer.
                                                             (line    6)
* operatore;<=:                          Confronti.          (line    6)
* operatore;==:                          Confronti.          (line    6)
* operatore;> (maggiore):                Confronti.          (line    6)
* operatore;>=:                          Confronti.          (line    6)
* operatore;>>:                          Operazioni Bitwise sui Tipi Integer.
                                                             (line    6)
* operatore;| (barra verticale):         Operazioni Bitwise sui Tipi Integer.
                                                             (line    6)
* operatore;~ (tilde):                   Operazioni Bitwise sui Tipi Integer.
                                                             (line    6)
* operatore;confronto:                   Confronti.          (line    6)
* operatore;e:                           Test del Valore di Verità.
                                                             (line   26)
* operatore;e <1>:                       Operazioni Booleane — and or not.
                                                             (line   24)
* operatore;è:                           Confronti.          (line    6)
* operatore;in:                          Confronti.          (line   67)
* operatore;in <1>:                      Operazioni Comuni sulle Sequenze.
                                                             (line   22)
* operatore;non:                         Operazioni Booleane — and or not.
                                                             (line   24)
* operatore;non è:                       Confronti.          (line    6)
* operatore;non in:                      Confronti.          (line   67)
* operatore;non in <1>:                  Operazioni Comuni sulle Sequenze.
                                                             (line   22)
* operatore;oppure:                      Test del Valore di Verità.
                                                             (line   26)
* operatore;oppure <1>:                  Operazioni Booleane — and or not.
                                                             (line   24)
* operators:                             Operators and delimiters.
                                                             (line    6)
* operazioni su;dizionario;type:         Tipi di Mapping — dict.
                                                             (line    6)
* operazioni su;intero;tipi:             Operazioni Bitwise sui Tipi Integer.
                                                             (line    6)
* operazioni su;list;type:               Tipi di Sequenza Mutabili.
                                                             (line   17)
* operazioni su;mapping;tipi:            Tipi di Mapping — dict.
                                                             (line    6)
* operazioni su;numerico;tipi:           Tipi Numerici — int float complex.
                                                             (line  104)
* operazioni su;sequenza;tipi:           Operazioni Comuni sulle Sequenze.
                                                             (line   22)
* operazioni su;sequenza;tipi <1>:       Tipi di Sequenza Mutabili.
                                                             (line   17)
* opmap (nel modulo dis):                Opcode collections. (line   17)
* opname (nel modulo dis):               Opcode collections. (line   13)
* OPT:                                   Debug options.      (line   39)
* optim_args_from_interpreter_flags() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  345)
* optimize (sys.flags attributo):        sys — System-specific parameters and functions.
                                                             (line  550)
* optimize() (nel modulo pickletools):   Programmatic interface.
                                                             (line   31)
* optimized scope:                       Glossary.           (line 1262)
* OPTIMIZED_BYTECODE_SUFFIXES (nel modulo importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line   30)
* Option (classe in optparse):           Option attributes.  (line    6)
* Optional (nel modulo typing):          Special forms.      (line   59)
* optional module:                       Glossary.           (line 1273)
* OptionConflictError:                   Exceptions<11>.     (line   11)
* OptionError:                           Exceptions<11>.     (line    6)
* OptionGroup (classe in optparse):      Grouping Options.   (line   12)
* OptionParser (classe in optparse):     Creating the parser.
                                                             (line    9)
* Options (classe in ssl):               Constants<9>.       (line  340)
* options (doctest.Example attributo):   Example Objects.    (line   53)
* options (ssl.SSLContext attributo):    SSL Contexts.       (line  572)
* options() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  138)
* OptionValueError:                      Exceptions<11>.     (line   16)
* optionxform() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  324)
* Or (classe in ast):                    Expressions<2>.     (line   86)
* or_() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line  149)
* ordered_attributes (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  195)
* OrderedDict (classe in collections):   OrderedDict objects.
                                                             (line   60)
* OrderedDict (classe in typing):        Aliases to types in collections.
                                                             (line   17)
* orig_argv (nel modulo sys):            sys — System-specific parameters and functions.
                                                             (line 1437)
* origin (importlib.machinery.ModuleSpec attributo): importlib machinery – Importers and path hooks.
                                                             (line  394)
* origin_req_host (urllib.request.Request attributo): Request Objects.
                                                             (line   30)
* origin_server (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  295)
* os_environ (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  169)
* OSError:                               Concrete exceptions.
                                                             (line  151)
* ottale;letterali:                      Tipi Numerici — int float complex.
                                                             (line   19)
* OUT_TO_DEFAULT (nel modulo msvcrt):    Other Functions.    (line   20)
* OUT_TO_MSGBOX (nel modulo msvcrt):     Other Functions.    (line   30)
* OUT_TO_STDERR (nel modulo msvcrt):     Other Functions.    (line   25)
* output:                                Expression statements.
                                                             (line   17)
* output (subprocess.CalledProcessError attributo): Using the subprocess Module.
                                                             (line  221)
* output (subprocess.TimeoutExpired attributo): Using the subprocess Module.
                                                             (line  182)
* output (unittest.TestCase attributo):  Test cases.         (line  456)
* output_charset (email.charset.Charset attributo): email charset Representing character sets.
                                                             (line   74)
* output_codec (email.charset.Charset attributo): email charset Representing character sets.
                                                             (line   88)
* output_difference() (doctest.OutputChecker metodo): OutputChecker objects.
                                                             (line   27)
* output() (http.cookies.BaseCookie metodo): Cookie Objects. (line   24)
* output() (http.cookies.Morsel metodo): Morsel Objects.     (line   83)
* OutputChecker (classe in doctest):     OutputChecker objects.
                                                             (line    6)
* OutputString() (http.cookies.Morsel metodo): Morsel Objects.
                                                             (line   98)
* OutsideDestinationError:               tarfile — Read and write tar archive files.
                                                             (line  289)
* Overflow (classe in decimal):          Signals.            (line   68)
* OverflowError:                         Concrete exceptions.
                                                             (line  216)
* OverflowError (built-in exception):    Integer Objects.    (line  167)
* OverflowError (built-in exception) <1>: Integer Objects.   (line  224)
* OverflowError (built-in exception) <2>: Integer Objects.   (line  268)
* OverflowError (built-in exception) <3>: Integer Objects.   (line  280)
* OverflowError (built-in exception) <4>: Integer Objects.   (line  292)
* OverflowError (built-in exception) <5>: Integer Objects.   (line  305)
* overlap_log (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  242)
* overlap() (statistics.NormalDist metodo): NormalDist objects.
                                                             (line  102)
* overlaps() (ipaddress.IPv4Network metodo): Network objects.
                                                             (line  155)
* overlaps() (ipaddress.IPv6Network metodo): Network objects.
                                                             (line  341)
* overlay() (curses.window metodo):      Window Objects.     (line  439)
* overload() (nel modulo typing):        Functions and decorators.
                                                             (line  247)
* override() (nel modulo typing):        Functions and decorators.
                                                             (line  372)
* overwrite() (curses.window metodo):    Window Objects.     (line  452)
* owner() (pathlib.Path metodo):         Permissions and ownership.
                                                             (line    6)
* p (pdb command):                       Debugger commands.  (line  279)
* P_ALL (nel modulo os):                 Process Management. (line  973)
* P_DETACH (nel modulo os):              Process Management. (line  703)
* P_NOWAIT (nel modulo os):              Process Management. (line  683)
* P_NOWAITO (nel modulo os):             Process Management. (line  683)
* P_OVERLAY (nel modulo os):             Process Management. (line  703)
* P_PGID (nel modulo os):                Process Management. (line  973)
* P_PID (nel modulo os):                 Process Management. (line  973)
* P_PIDFD (nel modulo os):               Process Management. (line  973)
* P_WAIT (nel modulo os):                Process Management. (line  693)
* pack_into() (nel modulo struct):       Functions and Exceptions.
                                                             (line   19)
* pack_into() (struct.Struct metodo):    Classes<2>.         (line   29)
* pack() (mailbox.MH metodo):            MH objects.         (line   67)
* pack() (nel modulo struct):            Functions and Exceptions.
                                                             (line   13)
* pack() (struct.Struct metodo):         Classes<2>.         (line   24)
* package:                               Packages.           (line    6)
* package <1>:                           site — Site-specific configuration hook.
                                                             (line   79)
* package <2>:                           Glossary.           (line 1283)
* package variable;__all__:              Importing Modules<2>.
                                                             (line    9)
* package;namespace:                     Namespace packages. (line    6)
* package;portion:                       Namespace packages. (line    6)
* package;regular:                       Regular packages.   (line    6)
* PackageMetadata (classe in importlib.metadata): Distribution metadata.
                                                             (line   14)
* PackageNotFoundError:                  Overview<3>.        (line   35)
* PackagePath (classe in importlib.metadata): Distribution files.
                                                             (line   18)
* packages_distributions() (nel modulo importlib.metadata): Mapping import to distribution packages.
                                                             (line    6)
* packed (ipaddress.IPv4Address attributo): Address objects. (line   75)
* packed (ipaddress.IPv6Address attributo): Address objects. (line  271)
* packing (widgets):                     The Packer.         (line    6)
* packing;binary;data:                   struct — Interpret bytes as packed binary data.
                                                             (line    8)
* PAGER:                                 pydoc — Documentation generator and online help system.
                                                             (line   46)
* pair_content() (nel modulo curses):    Functions<5>.       (line  396)
* pair_number() (nel modulo curses):     Functions<5>.       (line  402)
* pairwise() (nel modulo itertools):     Itertool Functions. (line  415)
* parallelism:                           Glossary.           (line 1292)
* parameter:                             Glossary.           (line 1303)
* Parameter (classe in inspect):         Introspecting callables with the Signature object.
                                                             (line  209)
* parameter;call semantics:              Calls.              (line   25)
* parameter;difference from argument:    How can I pass optional or keyword parameters from one function to another?.
                                                             (line   16)
* parameter;function definition:         Class Patterns.     (line  140)
* ParameterizedMIMEHeader (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  255)
* parameters (inspect.Signature attributo): Introspecting callables with the Signature object.
                                                             (line  114)
* params (email.headerregistry.ParameterizedMIMEHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  263)
* ParamSpec (classe in ast):             Type parameters.    (line   36)
* ParamSpec (classe in typing):          Building generic types and type aliases.
                                                             (line  399)
* ParamSpecArgs (nel modulo typing):     Building generic types and type aliases.
                                                             (line  531)
* ParamSpecKwargs (nel modulo typing):   Building generic types and type aliases.
                                                             (line  531)
* paramstyle (nel modulo sqlite3):       Module constants.   (line   70)
* pardir (nel modulo os):                Miscellaneous System Information.
                                                             (line  110)
* parent (importlib.machinery.ModuleSpec attributo): importlib machinery – Importers and path hooks.
                                                             (line  430)
* parent (logging.Logger attributo):     Logger Objects.     (line   42)
* parent (pathlib.PurePath attributo):   Methods and properties.
                                                             (line   94)
* parent (pyclbr.Class attributo):       Class Objects.      (line   28)
* parent (pyclbr.Function attributo):    Function Objects.   (line   27)
* parent (urllib.request.BaseHandler attributo): BaseHandler Objects.
                                                             (line   25)
* parent_process() (nel modulo multiprocessing): Miscellaneous<4>.
                                                             (line   42)
* parent() (tkinter.ttk.Treeview metodo): ttk Treeview.      (line  227)
* parenthesized form:                    Parenthesized forms.
                                                             (line    6)
* parentNode (xml.dom.Node attributo):   Node Objects.       (line   17)
* parents (collections.ChainMap attributo): ChainMap objects.
                                                             (line   64)
* parents (pathlib.PurePath attributo):  Methods and properties.
                                                             (line   78)
* paretovariate() (nel modulo random):   Real-valued distributions.
                                                             (line  101)
* parse_and_bind() (nel modulo readline): Init file.         (line    8)
* parse_args() (argparse.ArgumentParser metodo): The parse_args method.
                                                             (line    6)
* parse_args() (optparse.OptionParser metodo): Parsing arguments.
                                                             (line    9)
* PARSE_COLNAMES (nel modulo sqlite3):   Module constants.   (line   35)
* parse_config_h() (nel modulo sysconfig): Other functions<3>.
                                                             (line   53)
* PARSE_DECLTYPES (nel modulo sqlite3):  Module constants.   (line   13)
* parse_headers() (nel modulo http.client): http client — HTTP protocol client.
                                                             (line  111)
* parse_intermixed_args() (argparse.ArgumentParser metodo): Intermixed parsing.
                                                             (line    6)
* parse_known_args() (argparse.ArgumentParser metodo): Partial parsing.
                                                             (line    6)
* parse_known_intermixed_args() (argparse.ArgumentParser metodo): Intermixed parsing.
                                                             (line    9)
* parse_qs() (nel modulo urllib.parse):  URL Parsing.        (line  153)
* parse_qsl() (nel modulo urllib.parse): URL Parsing.        (line  204)
* parse() (doctest.DocTestParser metodo): DocTestParser objects.
                                                             (line   29)
* parse() (email.parser.BytesParser metodo): Parser API.     (line   35)
* parse() (email.parser.Parser metodo):  Parser API.         (line   87)
* parse() (nel modulo ast):              ast helpers.        (line    9)
* parse() (nel modulo xml.dom.minidom):  xml dom minidom — Minimal DOM implementation.
                                                             (line   35)
* parse() (nel modulo xml.dom.pulldom):  xml dom pulldom — Support for building partial DOM trees.
                                                             (line   85)
* parse() (nel modulo xml.etree.ElementTree): Functions<8>.  (line  178)
* parse() (nel modulo xml.sax):          xml sax — Support for SAX2 parsers.
                                                             (line   38)
* parse() (string.Formatter metodo):     Custom String Formatting.
                                                             (line   40)
* parse() (urllib.robotparser.RobotFileParser metodo): urllib robotparser — Parser for robots txt.
                                                             (line   29)
* parse() (xml.etree.ElementTree.ElementTree metodo): ElementTree Objects.
                                                             (line   54)
* Parse() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line    8)
* parse() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line    8)
* parseaddr() (nel modulo email.utils):  email utils Miscellaneous utilities.
                                                             (line   57)
* parsebytes() (email.parser.BytesParser metodo): Parser API.
                                                             (line   55)
* parsedate_to_datetime() (nel modulo email.utils): email utils Miscellaneous utilities.
                                                             (line  130)
* parsedate_tz() (nel modulo email.utils): email utils Miscellaneous utilities.
                                                             (line  119)
* parsedate() (nel modulo email.utils):  email utils Miscellaneous utilities.
                                                             (line  107)
* ParseError (classe in xml.etree.ElementTree): Exceptions<21>.
                                                             (line    6)
* ParseFile() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line   16)
* ParseFlags() (nel modulo imaplib):     imaplib — IMAP4 protocol client.
                                                             (line  125)
* parser:                                Lexical analysis.   (line    6)
* Parser (classe in email.parser):       Parser API.         (line   76)
* parser (pathlib.PurePath attributo):   Methods and properties.
                                                             (line    8)
* ParserCreate() (nel modulo xml.parsers.expat): xml parsers expat — Fast XML parsing using Expat.
                                                             (line   45)
* ParseResult (classe in urllib.parse):  Structured Parse Results.
                                                             (line   48)
* ParseResultBytes (classe in urllib.parse): Structured Parse Results.
                                                             (line   73)
* parsestr() (email.parser.Parser metodo): Parser API.       (line   97)
* parseString() (nel modulo xml.dom.minidom): xml dom minidom — Minimal DOM implementation.
                                                             (line   48)
* parseString() (nel modulo xml.dom.pulldom): xml dom pulldom — Support for building partial DOM trees.
                                                             (line   98)
* parseString() (nel modulo xml.sax):    xml sax — Support for SAX2 parsers.
                                                             (line   49)
* ParsingError:                          Exceptions<8>.      (line   65)
* partial (asyncio.IncompleteReadError attributo): Exceptions<15>.
                                                             (line   56)
* partial() (imaplib.IMAP4 metodo):      IMAP4 Objects.      (line  271)
* partial() (nel modulo functools):      functools — Higher-order functions and operations on callable objects.
                                                             (line  329)
* partialmethod (classe in functools):   functools — Higher-order functions and operations on callable objects.
                                                             (line  399)
* parties (asyncio.Barrier attributo):   Barrier.            (line   94)
* parties (threading.Barrier attributo): Barrier objects.    (line   93)
* partition() (bytearray metodo):        Operazioni su Bytes e Bytearray.
                                                             (line  194)
* partition() (bytes metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  194)
* partition() (str metodo):              Metodi per le Stringhe.
                                                             (line  525)
* partitioned (http.cookies.Morsel attributo): Morsel Objects.
                                                             (line   13)
* parts (pathlib.PurePath attributo):    Accessing individual parts.
                                                             (line    9)
* Pass (classe in ast):                  Statements.         (line  154)
* pass_() (poplib.POP3 metodo):          POP3 Objects.       (line   36)
* Paste:                                 Help menu Shell and Editor.
                                                             (line   30)
* patch.dict() (nel modulo unittest.mock): patch dict.       (line    6)
* patch.multiple() (nel modulo unittest.mock): patch multiple.
                                                             (line    6)
* patch.object() (nel modulo unittest.mock): patch object.   (line    6)
* patch.stopall() (nel modulo unittest.mock): patch methods start and stop.
                                                             (line   70)
* patch() (nel modulo test.support):     test support — Utilities for the Python test suite.
                                                             (line  687)
* patch() (nel modulo unittest.mock):    patch.              (line    9)
* PATH:                                  Changes in the Python API<5>.
                                                             (line  145)
* PATH <1>:                              Changes in “python” Command Behavior<2>.
                                                             (line    6)
* PATH <2>:                              Changes in “python” Command Behavior<2>.
                                                             (line   11)
* PATH <3>:                              Changes in “python” Command Behavior<2>.
                                                             (line   12)
* PATH <4>:                              macOS<8>.           (line   14)
* PATH <5>:                              Windows<28>.        (line   56)
* PATH <6>:                              Windows<32>.        (line   14)
* PATH <7>:                              Security<44>.       (line   16)
* PATH <8>:                              Security<44>.       (line   20)
* PATH <9>:                              Il percorso di ricerca del modulo.
                                                             (line   17)
* PATH <10>:                             Script Eseguibili Python.
                                                             (line   11)
* PATH <11>:                             Environment variables.
                                                             (line   27)
* PATH <12>:                             Miscellaneous.      (line   16)
* PATH <13>:                             Installation.       (line   19)
* PATH <14>:                             Installation.       (line   24)
* PATH <15>:                             Installation.       (line   32)
* PATH <16>:                             Configuration.      (line  114)
* PATH <17>:                             Shebang lines.      (line   40)
* PATH <18>:                             Shebang lines.      (line   42)
* PATH <19>:                             Shebang lines.      (line   49)
* PATH <20>:                             Advanced installation.
                                                             (line   10)
* PATH <21>:                             Advanced installation.
                                                             (line   28)
* PATH <22>:                             Advanced installation.
                                                             (line   31)
* PATH <23>:                             Installing free-threaded binaries.
                                                             (line   18)
* PATH <24>:                             Troubleshooting.    (line   33)
* PATH <25>:                             Troubleshooting.    (line   52)
* PATH <26>:                             Troubleshooting.    (line   68)
* PATH <27>:                             Troubleshooting.    (line  110)
* PATH <28>:                             Installation steps. (line   34)
* PATH <29>:                             Installation steps. (line   58)
* PATH <30>:                             Installing without UI.
                                                             (line   77)
* PATH <31>:                             Installing without UI.
                                                             (line   81)
* PATH <32>:                             Python launcher for Windows deprecated.
                                                             (line   17)
* PATH <33>:                             From the command-line.
                                                             (line    9)
* PATH <34>:                             Shebang lines<2>.   (line   54)
* PATH <35>:                             Shebang lines<2>.   (line   60)
* PATH <36>:                             Shebang lines<2>.   (line   62)
* PATH <37>:                             Shebang lines<2>.   (line   67)
* PATH <38>:                             Comparison to the os and os path modules.
                                                             (line   41)
* PATH <39>:                             Directory and files operations.
                                                             (line  449)
* PATH <40>:                             Directory and files operations.
                                                             (line  454)
* PATH <41>:                             Process Management. (line   45)
* PATH <42>:                             Process Management. (line   86)
* PATH <43>:                             Process Management. (line   89)
* PATH <44>:                             Process Management. (line   92)
* PATH <45>:                             Process Management. (line  549)
* PATH <46>:                             Process Management. (line  636)
* PATH <47>:                             Process Management. (line  640)
* PATH <48>:                             Process Management. (line  642)
* PATH <49>:                             Miscellaneous System Information.
                                                             (line  141)
* PATH <50>:                             Popen Constructor.  (line   35)
* PATH <51>:                             webbrowser — Convenient web-browser controller.
                                                             (line   59)
* PATH <52>:                             webbrowser — Convenient web-browser controller.
                                                             (line   33)
* PATH <53>:                             How venvs work.     (line   16)
* PATH <54>:                             How venvs work.     (line   61)
* PATH <55>:                             How venvs work.     (line   66)
* PATH <56>:                             site — Site-specific configuration hook.
                                                             (line   71)
* PATH <57>:                             Embedding Python<2>.
                                                             (line   31)
* PATH <58>:                             Embedding Python<2>.
                                                             (line   37)
* PATH <59>:                             How do I make a Python script executable on Unix?.
                                                             (line   24)
* PATH <60>:                             How do I make a Python script executable on Unix?.
                                                             (line   28)
* Path (classe in pathlib):              Concrete paths.     (line   11)
* Path (classe in zipfile):              Path objects.       (line    6)
* path (http.cookiejar.Cookie attributo): Cookie Objects<2>. (line   45)
* path (http.cookies.Morsel attributo):  Morsel Objects.     (line   13)
* path (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  144)
* path (ImportError attributo):          Concrete exceptions.
                                                             (line   65)
* path (importlib.abc.FileLoader attributo): importlib abc – Abstract base classes related to import.
                                                             (line  311)
* path (importlib.machinery.AppleFrameworkLoader attributo): importlib machinery – Importers and path hooks.
                                                             (line  506)
* path (importlib.machinery.ExtensionFileLoader attributo): importlib machinery – Importers and path hooks.
                                                             (line  311)
* path (importlib.machinery.FileFinder attributo): importlib machinery – Importers and path hooks.
                                                             (line  180)
* path (importlib.machinery.SourceFileLoader attributo): importlib machinery – Importers and path hooks.
                                                             (line  217)
* path (importlib.machinery.SourcelessFileLoader attributo): importlib machinery – Importers and path hooks.
                                                             (line  261)
* path (in module sys):                  Embedding Python<2>.
                                                             (line   12)
* path (in module sys) <1>:              Initializing and finalizing the interpreter.
                                                             (line    7)
* path (in module sys) <2>:              Process-wide parameters.
                                                             (line  142)
* path (nel modulo sys):                 sys — System-specific parameters and functions.
                                                             (line 1450)
* path (os.DirEntry attributo):          Files and Directories.
                                                             (line  955)
* path based finder:                     The Path Based Finder.
                                                             (line    6)
* path based finder <1>:                 Glossary.           (line 1375)
* Path browser:                          File menu Shell and Editor.
                                                             (line   22)
* path entry:                            Glossary.           (line 1355)
* path entry finder:                     Glossary.           (line 1360)
* path entry hook:                       Glossary.           (line 1369)
* path hooks:                            Import hooks.       (line    6)
* path_hook() (importlib.machinery.FileFinder metodo della classe): importlib machinery – Importers and path hooks.
                                                             (line  195)
* path_hooks (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line 1483)
* path_importer_cache (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line 1492)
* path_mtime() (importlib.abc.SourceLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  377)
* path_return_ok() (http.cookiejar.CookiePolicy metodo): CookiePolicy Objects.
                                                             (line   56)
* path_stats() (importlib.abc.SourceLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  355)
* path_stats() (importlib.machinery.SourceFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  226)
* path-like object:                      Glossary.           (line 1380)
* path;configuration;file:               site — Site-specific configuration hook.
                                                             (line   79)
* path;operations:                       pathlib — Object-oriented filesystem paths.
                                                             (line   10)
* path;operations <1>:                   os path — Common pathname manipulations.
                                                             (line    9)
* Path.stem (nel modulo zipfile):        Path objects.       (line   86)
* Path.suffix (nel modulo zipfile):      Path objects.       (line   79)
* Path.suffixes (nel modulo zipfile):    Path objects.       (line   92)
* path() (nel modulo importlib.resources): Functional API.   (line  110)
* pathconf_names (nel modulo os):        Files and Directories.
                                                             (line  666)
* pathconf() (nel modulo os):            Files and Directories.
                                                             (line  642)
* PathEntryFinder (classe in importlib.abc): importlib abc – Abstract base classes related to import.
                                                             (line   59)
* PATHEXT:                               Other Improvements<2>.
                                                             (line   30)
* PATHEXT <1>:                           Library<134>.       (line  138)
* PATHEXT <2>:                           Installing without UI.
                                                             (line   77)
* PATHEXT <3>:                           Installing without UI.
                                                             (line   81)
* PATHEXT <4>:                           Directory and files operations.
                                                             (line  464)
* PathFinder (classe in importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line  108)
* PathInfo (classe in pathlib.types):    Protocols.          (line   11)
* PathLike (classe in os):               Process Parameters. (line  143)
* pathname2url() (nel modulo urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  142)
* pathsep (nel modulo os):               Miscellaneous System Information.
                                                             (line  138)
* Pattern (classe in re):                Regular Expression Objects.
                                                             (line    6)
* Pattern (classe in typing):            Aliases to other concrete types.
                                                             (line    6)
* pattern (re.Pattern attributo):        Regular Expression Objects.
                                                             (line  124)
* pattern (re.PatternError attributo):   Exceptions<2>.      (line   19)
* pattern matching:                      The match statement.
                                                             (line    6)
* PatternError:                          Exceptions<2>.      (line    6)
* pause_reading() (asyncio.ReadTransport metodo): Read-only Transports.
                                                             (line   12)
* pause_writing() (asyncio.BaseProtocol metodo): Base Protocol.
                                                             (line   40)
* pause() (nel modulo signal):           Module contents<2>. (line  340)
* PAX_FORMAT (nel modulo tarfile):       tarfile — Read and write tar archive files.
                                                             (line  381)
* pax_headers (tarfile.TarFile attributo): TarFile Objects.  (line  331)
* pax_headers (tarfile.TarInfo attributo): TarInfo Objects.  (line  161)
* pbkdf2_hmac() (nel modulo hashlib):    Key derivation.     (line   11)
* pd() (nel modulo turtle):              Drawing state.      (line    6)
* Pdb (class in pdb):                    pdb — The Python Debugger.
                                                             (line   17)
* Pdb (classe in pdb):                   Command-line interface<8>.
                                                             (line  180)
* pdb command line option; -c:           Command-line interface<8>.
                                                             (line   18)
* pdb command line option; -command:     Command-line interface<8>.
                                                             (line   18)
* pdb command line option; -m:           Command-line interface<8>.
                                                             (line   25)
* pdb command line option; -p:           Command-line interface<8>.
                                                             (line   33)
* pdb command line option; -pid:         Command-line interface<8>.
                                                             (line   33)
* pdf() (statistics.NormalDist metodo):  NormalDist objects. (line   74)
* peek() (bz2.BZ2File metodo):           De compression of files.
                                                             (line   74)
* peek() (compression.zstd.ZstdFile metodo): Reading and writing compressed files.
                                                             (line   93)
* peek() (gzip.GzipFile metodo):         gzip — Support for gzip files.
                                                             (line  135)
* peek() (io.BufferedReader metodo):     Buffered Streams.   (line   78)
* peek() (lzma.LZMAFile metodo):         Reading and writing compressed files<2>.
                                                             (line   87)
* peek() (weakref.finalize metodo):      weakref — Weak references.
                                                             (line  307)
* PEM_cert_to_DER_cert() (nel modulo ssl): Certificate handling.
                                                             (line   57)
* pen() (nel modulo turtle):             Drawing state.      (line   33)
* pencolor() (nel modulo turtle):        Color control.      (line    6)
* pending (ssl.MemoryBIO attributo):     Memory BIO Support<2>.
                                                             (line  139)
* pending() (ssl.SSLSocket metodo):      SSL Sockets.        (line  339)
* PendingDeprecationWarning:             Warnings.           (line   28)
* pendown() (nel modulo turtle):         Drawing state.      (line    6)
* pensize() (nel modulo turtle):         Drawing state.      (line   18)
* penup() (nel modulo turtle):           Drawing state.      (line   12)
* PEP:                                   Glossary.           (line 1392)
* PERCENT (nel modulo token):            token — Constants used with Python parse trees.
                                                             (line  263)
* PERCENTEQUAL (nel modulo token):       token — Constants used with Python parse trees.
                                                             (line  311)
* perf_counter_ns() (nel modulo time):   Functions<4>.       (line  238)
* perf_counter() (nel modulo time):      Functions<4>.       (line  214)
* Performance:                           timeit — Measure execution time of small code snippets.
                                                             (line    8)
* perm() (nel modulo math):              Number-theoretic functions.
                                                             (line   66)
* PermissionError:                       OS exceptions.      (line   97)
* permutations() (nel modulo itertools): Itertool Functions. (line  438)
* persistence:                           pickle — Python object serialization.
                                                             (line    8)
* persistent_id (pickle protocol):       Persistence of External Objects.
                                                             (line    6)
* persistent_id() (pickle.Pickler metodo): Module Interface. (line  167)
* persistent_load (pickle protocol):     Persistence of External Objects.
                                                             (line    6)
* persistent_load() (pickle.Unpickler metodo): Module Interface.
                                                             (line  294)
* persistent;objects:                    pickle — Python object serialization.
                                                             (line    8)
* PF_CAN (nel modulo socket):            Constants<8>.       (line  135)
* PF_DIVERT (nel modulo socket):         Constants<8>.       (line  211)
* PF_PACKET (nel modulo socket):         Constants<8>.       (line  221)
* PF_RDS (nel modulo socket):            Constants<8>.       (line  243)
* pformat() (nel modulo pprint):         Functions<3>.       (line   76)
* pformat() (pprint.PrettyPrinter metodo): PrettyPrinter Objects.
                                                             (line   51)
* pgettext() (gettext.GNUTranslations metodo): The GNUTranslations class.
                                                             (line   68)
* pgettext() (gettext.NullTranslations metodo): The NullTranslations class.
                                                             (line   47)
* pgettext() (nel modulo gettext):       GNU gettext API.    (line   63)
* PGO (nel modulo test.support):         test support — Utilities for the Python test suite.
                                                             (line  124)
* phase() (nel modulo cmath):            Conversions to and from polar coordinates.
                                                             (line   20)
* Philbrick, Geoff:                      Keyword Parameters for Extension Functions.
                                                             (line   25)
* physical line:                         Logical lines.      (line    6)
* physical line <1>:                     Explicit line joining.
                                                             (line    6)
* physical line <2>:                     Formal grammar.     (line   28)
* pi (nel modulo cmath):                 Constants<3>.       (line    6)
* pi (nel modulo math):                  Constants<2>.       (line    6)
* pi() (xml.etree.ElementTree.TreeBuilder metodo): TreeBuilder Objects.
                                                             (line   56)
* pickle command line option; pickle_file: Command-line interface.
                                                             (line   16)
* pickle() (nel modulo copyreg):         copyreg — Register pickle support functions.
                                                             (line   23)
* PickleBuffer (classe in pickle):       Module Interface.   (line  324)
* PickleError:                           Module Interface.   (line  101)
* Pickler (classe in pickle):            Module Interface.   (line  127)
* pickletools command line option; -a:   Command-line options<6>.
                                                             (line    6)
* pickletools command line option; -annotate: Command-line options<6>.
                                                             (line    6)
* pickletools command line option; -indentlevel: Command-line options<6>.
                                                             (line   14)
* pickletools command line option; -l:   Command-line options<6>.
                                                             (line   14)
* pickletools command line option; -m:   Command-line options<6>.
                                                             (line   18)
* pickletools command line option; -memo: Command-line options<6>.
                                                             (line   18)
* pickletools command line option; -o:   Command-line options<6>.
                                                             (line   10)
* pickletools command line option; -output: Command-line options<6>.
                                                             (line   10)
* pickletools command line option; -p:   Command-line options<6>.
                                                             (line   23)
* pickletools command line option; -preamble: Command-line options<6>.
                                                             (line   23)
* pickletools command line option; pickle_file: Command-line options<6>.
                                                             (line   28)
* pickling;objects:                      pickle — Python object serialization.
                                                             (line    8)
* PicklingError:                         Module Interface.   (line  106)
* pid (asyncio.subprocess.Process attributo): Interacting with Subprocesses.
                                                             (line  138)
* pid (multiprocessing.Process attributo): Process and exceptions.
                                                             (line  154)
* pid (subprocess.Popen attributo):      Popen Objects.      (line  150)
* PIDFD_NONBLOCK (nel modulo os):        Process Management. (line  378)
* pidfd_open() (nel modulo os):          Process Management. (line  365)
* pidfd_send_signal() (nel modulo signal): Module contents<2>.
                                                             (line  358)
* PIP_USER:                              Windows<49>.        (line  102)
* PIPE (nel modulo subprocess):          Using the subprocess Module.
                                                             (line  150)
* PIPE_BUF (nel modulo select):          select — Waiting for I/O completion.
                                                             (line  164)
* pipe_connection_lost() (asyncio.SubprocessProtocol metodo): Subprocess Protocols.
                                                             (line   19)
* pipe_data_received() (asyncio.SubprocessProtocol metodo): Subprocess Protocols.
                                                             (line   10)
* PIPE_MAX_SIZE (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  128)
* Pipe() (nel modulo multiprocessing):   Pipes and Queues.   (line   80)
* pipe() (nel modulo os):                File Descriptor Operations.
                                                             (line  493)
* pipe2() (nel modulo os):               File Descriptor Operations.
                                                             (line  504)
* Placeholder (nel modulo functools):    functools — Higher-order functions and operations on callable objects.
                                                             (line  321)
* placeholder (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  282)
* platform (in module sys):              Process-wide parameters.
                                                             (line  180)
* platform (nel modulo sys):             sys — System-specific parameters and functions.
                                                             (line 1502)
* platform command line option; -nonaliased: Command-line usage<3>.
                                                             (line   19)
* platform command line option; -terse:  Command-line usage<3>.
                                                             (line   13)
* platform() (nel modulo platform):      Cross platform.     (line   48)
* platlibdir (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line 1574)
* PlaySound() (nel modulo winsound):     winsound — Sound-playing interface for Windows.
                                                             (line   22)
* plist;file:                            plistlib — Generate and parse Apple plist files.
                                                             (line    8)
* plock() (nel modulo os):               Process Management. (line  390)
* plus:                                  Unary arithmetic and bitwise operations.
                                                             (line   14)
* PLUS (nel modulo token):               token — Constants used with Python parse trees.
                                                             (line  233)
* plus() (decimal.Context metodo):       Context objects.    (line  452)
* PLUSEQUAL (nel modulo token):          token — Constants used with Python parse trees.
                                                             (line  299)
* pm() (nel modulo pdb):                 Command-line interface<8>.
                                                             (line  150)
* POINTER() (nel modulo ctypes):         Utility functions.  (line  215)
* pointer() (nel modulo ctypes):         Utility functions.  (line  229)
* polar() (nel modulo cmath):            Conversions to and from polar coordinates.
                                                             (line   38)
* Policy (classe in email.policy):       email policy Policy Objects.
                                                             (line  129)
* poll() (multiprocessing.connection.Connection metodo): Connection Objects.
                                                             (line   42)
* poll() (nel modulo select):            select — Waiting for I/O completion.
                                                             (line   91)
* poll() (select.devpoll metodo):        /dev/poll Polling Objects.
                                                             (line   65)
* poll() (select.epoll metodo):          Edge and Level Trigger Polling epoll Objects.
                                                             (line  102)
* poll() (select.poll metodo):           Polling Objects.    (line   77)
* poll() (subprocess.Popen metodo):      Popen Objects.      (line    8)
* PollSelector (classe in selectors):    Classes<3>.         (line  171)
* poly() (nel modulo turtle):            Special Turtle methods.
                                                             (line    6)
* Pool (classe in multiprocessing.pool): Process Pools.      (line    9)
* pop_all() (contextlib.ExitStack metodo): Utilities.        (line  594)
* POP_BLOCK (opcode):                    Python Bytecode Instructions.
                                                             (line 1481)
* POP_EXCEPT (opcode):                   Python Bytecode Instructions.
                                                             (line  435)
* POP_ITER (opcode):                     Python Bytecode Instructions.
                                                             (line  147)
* POP_JUMP_IF_FALSE (opcode):            Python Bytecode Instructions.
                                                             (line  889)
* POP_JUMP_IF_NONE (opcode):             Python Bytecode Instructions.
                                                             (line  915)
* POP_JUMP_IF_NOT_NONE (opcode):         Python Bytecode Instructions.
                                                             (line  905)
* POP_JUMP_IF_TRUE (opcode):             Python Bytecode Instructions.
                                                             (line  873)
* pop_source() (shlex.shlex metodo):     shlex Objects.      (line   63)
* POP_TOP (opcode):                      Python Bytecode Instructions.
                                                             (line  153)
* pop() (array.array metodo):            array — Efficient arrays of numeric values.
                                                             (line  215)
* pop() (collections.deque metodo):      deque objects.      (line   87)
* pop() (dict metodo):                   Tipi di Mapping — dict.
                                                             (line  204)
* pop() (mailbox.Mailbox metodo):        Mailbox objects.    (line  217)
* pop() (sequence metodo):               Tipi di Sequenza Mutabili.
                                                             (line  105)
* pop() (set metodo):                    Tipi di Insiemi — set frozenset.
                                                             (line  220)
* POP3 (classe in poplib):               poplib — POP3 protocol client.
                                                             (line   34)
* POP3_SSL (classe in poplib):           poplib — POP3 protocol client.
                                                             (line   54)
* POP3;protocol:                         poplib — POP3 protocol client.
                                                             (line    8)
* Popen (classe in subprocess):          Popen Constructor.  (line   11)
* popen() (in module os):                I/O objects also known as file objects.
                                                             (line    6)
* popen() (in module os) <1>:            select — Waiting for I/O completion.
                                                             (line  145)
* popen() (nel modulo os):               Process Management. (line  397)
* popitem() (collections.OrderedDict metodo): OrderedDict objects.
                                                             (line   67)
* popitem() (dict metodo):               Tipi di Mapping — dict.
                                                             (line  213)
* popitem() (mailbox.Mailbox metodo):    Mailbox objects.    (line  226)
* popleft() (collections.deque metodo):  deque objects.      (line   92)
* port (http.cookiejar.Cookie attributo): Cookie Objects<2>. (line   36)
* port_specified (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   81)
* portion:                               Glossary.           (line 1408)
* pos (json.JSONDecodeError attributo):  Exceptions<19>.     (line   19)
* pos (re.Match attributo):              Match Objects.      (line  179)
* pos (re.PatternError attributo):       Exceptions<2>.      (line   23)
* pos (tomllib.TOMLDecodeError attributo): tomllib — Parse TOML files.
                                                             (line   73)
* pos() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line  154)
* pos() (nel modulo turtle):             Tell Turtle’s state.
                                                             (line    6)
* position (xml.etree.ElementTree.ParseError attributo): Exceptions<21>.
                                                             (line   20)
* position() (nel modulo turtle):        Tell Turtle’s state.
                                                             (line    6)
* positional argument:                   Glossary.           (line 1414)
* Positions (classe in dis):             Python Bytecode Instructions.
                                                             (line  110)
* positions (inspect.FrameInfo attributo): The interpreter stack.
                                                             (line   42)
* positions (inspect.Traceback attributo): The interpreter stack.
                                                             (line   83)
* Positions.col_offset (nel modulo dis): Python Bytecode Instructions.
                                                             (line  119)
* Positions.end_col_offset (nel modulo dis): Python Bytecode Instructions.
                                                             (line  121)
* Positions.end_lineno (nel modulo dis): Python Bytecode Instructions.
                                                             (line  117)
* Positions.lineno (nel modulo dis):     Python Bytecode Instructions.
                                                             (line  115)
* POSIX Shared Memory:                   multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line   10)
* POSIX_FADV_DONTNEED (nel modulo os):   File Descriptor Operations.
                                                             (line  538)
* POSIX_FADV_NOREUSE (nel modulo os):    File Descriptor Operations.
                                                             (line  538)
* POSIX_FADV_NORMAL (nel modulo os):     File Descriptor Operations.
                                                             (line  538)
* POSIX_FADV_RANDOM (nel modulo os):     File Descriptor Operations.
                                                             (line  538)
* POSIX_FADV_SEQUENTIAL (nel modulo os): File Descriptor Operations.
                                                             (line  538)
* POSIX_FADV_WILLNEED (nel modulo os):   File Descriptor Operations.
                                                             (line  538)
* posix_fadvise() (nel modulo os):       File Descriptor Operations.
                                                             (line  524)
* posix_fallocate() (nel modulo os):     File Descriptor Operations.
                                                             (line  515)
* posix_openpt() (nel modulo os):        File Descriptor Operations.
                                                             (line  565)
* POSIX_SPAWN_CLOSE (nel modulo os):     Process Management. (line  468)
* POSIX_SPAWN_CLOSEFROM (nel modulo os): Process Management. (line  480)
* POSIX_SPAWN_DUP2 (nel modulo os):      Process Management. (line  474)
* POSIX_SPAWN_OPEN (nel modulo os):      Process Management. (line  462)
* posix_spawn() (nel modulo os):         Process Management. (line  439)
* posix_spawnp() (nel modulo os):        Process Management. (line  541)
* POSIX;I/O control:                     termios — POSIX style tty control.
                                                             (line    6)
* PosixPath (classe in pathlib):         Concrete paths.     (line   22)
* post_handshake_auth (ssl.SSLContext attributo): SSL Contexts.
                                                             (line  590)
* post_mortem() (nel modulo pdb):        Command-line interface<8>.
                                                             (line  140)
* post_setup() (venv.EnvBuilder metodo): API<2>.             (line  178)
* postcmd() (cmd.Cmd metodo):            Cmd Objects.        (line  104)
* postloop() (cmd.Cmd metodo):           Cmd Objects.        (line  122)
* Pow (classe in ast):                   Expressions<2>.     (line   53)
* pow() (nel modulo math):               Power exponential and logarithmic functions.
                                                             (line   72)
* pow() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line  159)
* power;operation:                       The power operator. (line    6)
* power() (decimal.Context metodo):      Context objects.    (line  458)
* pp (pdb command):                      Debugger commands.  (line  287)
* pp() (nel modulo pprint):              Functions<3>.       (line    6)
* pprint() (nel modulo pprint):          Functions<3>.       (line   67)
* pprint() (pprint.PrettyPrinter metodo): PrettyPrinter Objects.
                                                             (line   57)
* prcal() (nel modulo calendar):         calendar — General calendar-related functions.
                                                             (line  407)
* pread() (nel modulo os):               File Descriptor Operations.
                                                             (line  552)
* preadv() (nel modulo os):              File Descriptor Operations.
                                                             (line  583)
* preamble (email.message.EmailMessage attributo): email message Representing an email message.
                                                             (line  680)
* preamble (email.message.Message attributo): email message Message Representing an email message using the compat32 API.
                                                             (line  694)
* prec (decimal.Context attributo):      Context objects.    (line  132)
* precmd() (cmd.Cmd metodo):             Cmd Objects.        (line   94)
* prefix (nel modulo sys):               sys — System-specific parameters and functions.
                                                             (line 1599)
* prefix (xml.dom.Attr attributo):       Attr Objects.       (line   18)
* prefix (xml.dom.Node attributo):       Node Objects.       (line   69)
* prefix (zipimport.zipimporter attributo): zipimporter Objects.
                                                             (line  101)
* PREFIXES (nel modulo site):            Module contents<5>. (line    6)
* prefixlen (ipaddress.IPv4Network attributo): Network objects.
                                                             (line  132)
* prefixlen (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  330)
* preloop() (cmd.Cmd metodo):            Cmd Objects.        (line  116)
* prepare_class() (nel modulo types):    Dynamic Type Creation.
                                                             (line   23)
* prepare_input_source() (nel modulo xml.sax.saxutils): xml sax saxutils — SAX Utilities.
                                                             (line   82)
* prepare_main() (concurrent.interpreters.Interpreter metodo): Interpreter objects.
                                                             (line   35)
* prepare() (graphlib.TopologicalSorter metodo): graphlib — Functionality to operate with graph-like structures.
                                                             (line  100)
* prepare() (logging.handlers.QueueHandler metodo): QueueHandler.
                                                             (line   53)
* prepare() (logging.handlers.QueueListener metodo): QueueListener.
                                                             (line   64)
* PrepareProtocol (classe in sqlite3):   PrepareProtocol objects.
                                                             (line    6)
* PrettyPrinter (classe in pprint):      PrettyPrinter Objects.
                                                             (line    6)
* prev() (tkinter.ttk.Treeview metodo):  ttk Treeview.       (line  232)
* previousSibling (xml.dom.Node attributo): Node Objects.    (line   32)
* primary:                               Primaries.          (line    6)
* print_call_graph() (nel modulo asyncio): Call Graph Introspection.
                                                             (line   17)
* print_callees() (pstats.Stats metodo): The Stats Class.    (line  217)
* print_callers() (pstats.Stats metodo): The Stats Class.    (line  196)
* print_exc() (nel modulo traceback):    Module-Level Functions<2>.
                                                             (line   58)
* print_exc() (timeit.Timer metodo):     Python Interface.   (line  138)
* print_exception() (nel modulo traceback): Module-Level Functions<2>.
                                                             (line   24)
* print_function (nel modulo __future__): Module Contents<5>.
                                                             (line   35)
* print_help() (argparse.ArgumentParser metodo): Printing help.
                                                             (line   16)
* print_last() (nel modulo traceback):   Module-Level Functions<2>.
                                                             (line   63)
* print_list() (nel modulo traceback):   Module-Level Functions<2>.
                                                             (line  101)
* print_stack() (asyncio.Task metodo):   Task Object.        (line  143)
* print_stack() (nel modulo traceback):  Module-Level Functions<2>.
                                                             (line   70)
* print_stats() (profile.Profile metodo): profile and cProfile Module Reference.
                                                             (line   91)
* print_stats() (pstats.Stats metodo):   The Stats Class.    (line  164)
* print_tb() (nel modulo traceback):     Module-Level Functions<2>.
                                                             (line    6)
* print_usage() (argparse.ArgumentParser metodo): Printing help.
                                                             (line   10)
* print_usage() (optparse.OptionParser metodo): Other methods.
                                                             (line   15)
* print_version() (optparse.OptionParser metodo): Printing a version string.
                                                             (line   26)
* print_warning() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  433)
* print() (built-in function);__str__() (object method): Basic customization.
                                                             (line  131)
* print() (traceback.TracebackException metodo): TracebackException Objects.
                                                             (line  136)
* printable (nel modulo string):         String constants.   (line   41)
* printdir() (zipfile.ZipFile metodo):   ZipFile objects.    (line  242)
* PRIO_DARWIN_BG (nel modulo os):        Process Parameters. (line  326)
* PRIO_DARWIN_NONUI (nel modulo os):     Process Parameters. (line  326)
* PRIO_DARWIN_PROCESS (nel modulo os):   Process Parameters. (line  326)
* PRIO_DARWIN_THREAD (nel modulo os):    Process Parameters. (line  326)
* PRIO_PGRP (nel modulo os):             Process Parameters. (line  315)
* PRIO_PROCESS (nel modulo os):          Process Parameters. (line  315)
* PRIO_USER (nel modulo os):             Process Parameters. (line  315)
* PriorityQueue (classe in asyncio):     Priority Queue.     (line    6)
* PriorityQueue (classe in queue):       queue — A synchronized queue class.
                                                             (line   50)
* private;names:                         Identifiers Names.  (line   14)
* prlimit() (nel modulo resource):       Resource Limits.    (line   56)
* prmonth() (calendar.TextCalendar metodo): calendar — General calendar-related functions.
                                                             (line  203)
* prmonth() (nel modulo calendar):       calendar — General calendar-related functions.
                                                             (line  398)
* ProactorEventLoop (classe in asyncio): Event Loop Implementations.
                                                             (line   31)
* procedure;call:                        Expression statements.
                                                             (line   17)
* Process (classe in multiprocessing):   Process and exceptions.
                                                             (line    6)
* process_cpu_count() (nel modulo os):   Miscellaneous System Information.
                                                             (line   60)
* process_exited() (asyncio.SubprocessProtocol metodo): Subprocess Protocols.
                                                             (line   26)
* process_request() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line  160)
* process_time_ns() (nel modulo time):   Functions<4>.       (line  258)
* process_time() (nel modulo time):      Functions<4>.       (line  245)
* process_tokens() (nel modulo tabnanny): tabnanny — Detection of ambiguous indentation.
                                                             (line   42)
* process;group:                         Process Parameters. (line  216)
* process;group <1>:                     Process Parameters. (line  278)
* process;id:                            Process Parameters. (line  284)
* process;id of parent:                  Process Parameters. (line  291)
* process;killing:                       Process Management. (line  329)
* process;killing <1>:                   Process Management. (line  351)
* process;scheduling priority:           Process Parameters. (line  302)
* process;scheduling priority <1>:       Process Parameters. (line  491)
* process;signalling:                    Process Management. (line  329)
* process;signalling <1>:                Process Management. (line  351)
* process() (logging.LoggerAdapter metodo): LoggerAdapter Objects.
                                                             (line   23)
* ProcessError:                          Process and exceptions.
                                                             (line  282)
* processes, light-weight:               _thread — Low-level threading API.
                                                             (line    6)
* ProcessingInstruction() (nel modulo xml.etree.ElementTree): Functions<8>.
                                                             (line  185)
* processingInstruction() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line  162)
* ProcessingInstructionHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  324)
* ProcessLookupError:                    OS exceptions.      (line  107)
* processor time:                        Functions<4>.       (line  247)
* processor time <1>:                    Functions<4>.       (line  616)
* processor() (nel modulo platform):     Cross platform.     (line   69)
* ProcessPoolExecutor (classe in concurrent.futures): ProcessPoolExecutor.
                                                             (line   27)
* prod() (nel modulo math):              Summation and product functions.
                                                             (line   51)
* product() (nel modulo itertools):      Itertool Functions. (line  490)
* Profile (classe in profile):           profile and cProfile Module Reference.
                                                             (line   35)
* profile function:                      Reference<2>.       (line  138)
* profile function <1>:                  Reference<2>.       (line  154)
* profile function <2>:                  sys — System-specific parameters and functions.
                                                             (line  975)
* profile function <3>:                  sys — System-specific parameters and functions.
                                                             (line 1655)
* PROFILE_TASK:                          Build<22>.          (line   13)
* PROFILE_TASK <1>:                      Performance options.
                                                             (line   12)
* profiler:                              sys — System-specific parameters and functions.
                                                             (line  975)
* profiler <1>:                          sys — System-specific parameters and functions.
                                                             (line 1655)
* profiling, deterministic:              Introduction to the profilers.
                                                             (line    6)
* program:                               Complete Python programs.
                                                             (line    6)
* ProgrammingError:                      Exceptions<6>.      (line   78)
* Progressbar (classe in tkinter.ttk):   ttk Progressbar.    (line    6)
* prompt (cmd.Cmd attributo):            Cmd Objects.        (line  131)
* prompts, interpreter:                  sys — System-specific parameters and functions.
                                                             (line 1624)
* propagate (logging.Logger attributo):  Logger Objects.     (line   50)
* property (classe built-in):            Funzioni Incorporate.
                                                             (line 1669)
* property list:                         plistlib — Generate and parse Apple plist files.
                                                             (line    8)
* property_declaration_handler (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line  111)
* property_dom_node (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line  118)
* property_lexical_handler (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line  104)
* property_xml_string (nel modulo xml.sax.handler): xml sax handler — Base classes for SAX handlers.
                                                             (line  125)
* property() (nel modulo enum):          Utilities and Decorators.
                                                             (line   39)
* PropertyMock (classe in unittest.mock): The Mock Class.    (line  651)
* prot_c() (ftplib.FTP_TLS metodo):      FTP_TLS objects.    (line  110)
* prot_p() (ftplib.FTP_TLS metodo):      FTP_TLS objects.    (line  106)
* proto (socket.socket attributo):       Socket Objects.     (line  629)
* Protocol (classe in asyncio):          Base Protocols.     (line   10)
* Protocol (classe in typing):           Other special directives.
                                                             (line  142)
* protocol (ssl.SSLContext attributo):   SSL Contexts.       (line  609)
* PROTOCOL_SSLv23 (nel modulo ssl):      Constants<9>.       (line  161)
* PROTOCOL_SSLv3 (nel modulo ssl):       Constants<9>.       (line  168)
* PROTOCOL_TLS (nel modulo ssl):         Constants<9>.       (line  131)
* PROTOCOL_TLS_CLIENT (nel modulo ssl):  Constants<9>.       (line  144)
* PROTOCOL_TLS_SERVER (nel modulo ssl):  Constants<9>.       (line  153)
* PROTOCOL_TLSv1 (nel modulo ssl):       Constants<9>.       (line  184)
* PROTOCOL_TLSv1_1 (nel modulo ssl):     Constants<9>.       (line  191)
* PROTOCOL_TLSv1_2 (nel modulo ssl):     Constants<9>.       (line  201)
* protocol_version (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  209)
* PROTOCOL_VERSION (imaplib.IMAP4 attributo): IMAP4 Objects. (line  474)
* ProtocolError (classe in xmlrpc.client): ProtocolError Objects.
                                                             (line    6)
* protocollo buffer;str (classe incorporata): Tipo Sequenza di Testo — str.
                                                             (line   68)
* protocollo buffer;tipi di sequenze binarie: Formattazione delle stringhe in stile printf.
                                                             (line  197)
* protocollo di gestione del contesto:   Tipi di gestori di contesti.
                                                             (line    6)
* protocollo iteratore:                  Tipi di Iteratore.  (line    6)
* protocollo;gestione del contesto:      Tipi di gestori di contesti.
                                                             (line    6)
* protocollo;iteratore:                  Tipi di Iteratore.  (line    6)
* provisional API:                       Glossary.           (line 1418)
* provisional package:                   Glossary.           (line 1438)
* proxy() (nel modulo weakref):          weakref — Weak references.
                                                             (line  136)
* proxyauth() (imaplib.IMAP4 metodo):    IMAP4 Objects.      (line  276)
* ProxyBasicAuthHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  415)
* ProxyDigestAuthHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  450)
* ProxyHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  341)
* ProxyType (nel modulo weakref):        weakref — Weak references.
                                                             (line  336)
* ProxyTypes (nel modulo weakref):       weakref — Weak references.
                                                             (line  344)
* pryear() (calendar.TextCalendar metodo): calendar — General calendar-related functions.
                                                             (line  218)
* ps1 (nel modulo sys):                  sys — System-specific parameters and functions.
                                                             (line 1621)
* ps2 (nel modulo sys):                  sys — System-specific parameters and functions.
                                                             (line 1621)
* pstdev() (nel modulo statistics):      Function details.   (line  371)
* pthread_getcpuclockid() (nel modulo time): Functions<4>.   (line   21)
* pthread_kill() (nel modulo signal):    Module contents<2>. (line  373)
* pthread_sigmask() (nel modulo signal): Module contents<2>. (line  403)
* pthreads:                              _thread — Low-level threading API.
                                                             (line   16)
* pthreads (sys._emscripten_info attributo): sys — System-specific parameters and functions.
                                                             (line  359)
* ptsname() (nel modulo os):             File Descriptor Operations.
                                                             (line  642)
* pu() (nel modulo turtle):              Drawing state.      (line   12)
* publicId (xml.dom.DocumentType attributo): DocumentType Objects.
                                                             (line   17)
* PullDOM (classe in xml.dom.pulldom):   xml dom pulldom — Support for building partial DOM trees.
                                                             (line   77)
* punctuation (nel modulo string):       String constants.   (line   36)
* punctuation_chars (shlex.shlex attributo): shlex Objects.  (line  183)
* PurePath (classe in pathlib):          Pure paths.         (line   10)
* PurePosixPath (classe in pathlib):     Pure paths.         (line   72)
* PureWindowsPath (classe in pathlib):   Pure paths.         (line   82)
* purge() (nel modulo re):               Functions.          (line  290)
* Purpose.CLIENT_AUTH (nel modulo ssl):  Constants<9>.       (line  546)
* Purpose.SERVER_AUTH (nel modulo ssl):  Constants<9>.       (line  537)
* push_async_callback() (contextlib.AsyncExitStack metodo): Utilities.
                                                             (line  645)
* push_async_exit() (contextlib.AsyncExitStack metodo): Utilities.
                                                             (line  640)
* PUSH_EXC_INFO (opcode):                Python Bytecode Instructions.
                                                             (line  454)
* PUSH_NULL (opcode):                    Python Bytecode Instructions.
                                                             (line 1143)
* push_source() (shlex.shlex metodo):    shlex Objects.      (line   56)
* push_token() (shlex.shlex metodo):     shlex Objects.      (line   16)
* push() (code.InteractiveConsole metodo): Interactive Console Objects.
                                                             (line   28)
* push() (contextlib.ExitStack metodo):  Utilities.          (line  561)
* put_nowait() (asyncio.Queue metodo):   Queue.              (line   73)
* put_nowait() (multiprocessing.Queue metodo): Pipes and Queues.
                                                             (line  151)
* put_nowait() (queue.Queue metodo):     Queue Objects.      (line   42)
* put_nowait() (queue.SimpleQueue metodo): SimpleQueue Objects.
                                                             (line   35)
* put() (asyncio.Queue metodo):          Queue.              (line   65)
* put() (multiprocessing.Queue metodo):  Pipes and Queues.   (line  135)
* put() (multiprocessing.SimpleQueue metodo): Pipes and Queues.
                                                             (line  253)
* put() (queue.Queue metodo):            Queue Objects.      (line   29)
* put() (queue.SimpleQueue metodo):      SimpleQueue Objects.
                                                             (line   20)
* putch() (nel modulo msvcrt):           Console I/O.        (line   36)
* putenv() (nel modulo os):              Process Parameters. (line  375)
* putheader() (http.client.HTTPConnection metodo): HTTPConnection Objects.
                                                             (line  183)
* putp() (nel modulo curses):            Functions<5>.       (line  408)
* putrequest() (http.client.HTTPConnection metodo): HTTPConnection Objects.
                                                             (line  172)
* putwch() (nel modulo msvcrt):          Console I/O.        (line   40)
* putwin() (curses.window metodo):       Window Objects.     (line  465)
* pvariance() (nel modulo statistics):   Function details.   (line  380)
* pwd() (ftplib.FTP metodo):             FTP objects.        (line  345)
* pwrite() (nel modulo os):              File Descriptor Operations.
                                                             (line  656)
* pwritev() (nel modulo os):             File Descriptor Operations.
                                                             (line  667)
* Py_ABS (C macro):                      Useful macros.      (line   12)
* Py_AddPendingCall (C function):        Asynchronous Notifications.
                                                             (line   10)
* Py_ALWAYS_INLINE (C macro):            Useful macros.      (line   21)
* Py_am_aiter (C macro):                 Async Object Structures.
                                                             (line   41)
* Py_am_anext (C macro):                 Async Object Structures.
                                                             (line   56)
* Py_am_await (C macro):                 Async Object Structures.
                                                             (line   26)
* Py_am_send (C macro):                  Async Object Structures.
                                                             (line   68)
* Py_ARRAY_LENGTH (C macro):             Useful macros.      (line  234)
* Py_ASNATIVEBYTES_ALLOW_INDEX (C macro): Integer Objects.   (line  539)
* Py_ASNATIVEBYTES_BIG_ENDIAN (C macro): Integer Objects.    (line  519)
* Py_ASNATIVEBYTES_DEFAULTS (C macro):   Integer Objects.    (line  515)
* Py_ASNATIVEBYTES_LITTLE_ENDIAN (C macro): Integer Objects. (line  523)
* Py_ASNATIVEBYTES_NATIVE_ENDIAN (C macro): Integer Objects. (line  527)
* Py_ASNATIVEBYTES_REJECT_NEGATIVE (C macro): Integer Objects.
                                                             (line  535)
* Py_ASNATIVEBYTES_UNSIGNED_BUFFER (C macro): Integer Objects.
                                                             (line  531)
* Py_AtExit (C function):                Process Control.    (line   33)
* Py_AUDIT_READ (C macro):               Member flags.       (line   12)
* Py_AuditHookFunction (C type):         System Functions.   (line  151)
* Py_BEGIN_ALLOW_THREADS (C macro):      Detaching the thread state from extension code.
                                                             (line   19)
* Py_BEGIN_ALLOW_THREADS (C macro) <1>:  High-level API.     (line  211)
* Py_BEGIN_CRITICAL_SECTION (C macro):   Python Critical Section API.
                                                             (line   64)
* Py_BEGIN_CRITICAL_SECTION_MUTEX (C macro): Python Critical Section API.
                                                             (line   79)
* Py_BEGIN_CRITICAL_SECTION2 (C macro):  Python Critical Section API.
                                                             (line  110)
* Py_BEGIN_CRITICAL_SECTION2_MUTEX (C macro): Python Critical Section API.
                                                             (line  126)
* Py_bf_getbuffer (C macro):             Buffer Object Structures.
                                                             (line   16)
* Py_bf_releasebuffer (C macro):         Buffer Object Structures.
                                                             (line   67)
* Py_BLOCK_THREADS (C macro):            High-level API.     (line  225)
* Py_buffer (C type):                    Buffer structure.   (line   25)
* Py_buffer.buf (C member):              Buffer structure.   (line   27)
* Py_buffer.format (C member):           Buffer structure.   (line   89)
* Py_buffer.internal (C member):         Buffer structure.   (line  152)
* Py_buffer.itemsize (C member):         Buffer structure.   (line   69)
* Py_buffer.len (C member):              Buffer structure.   (line   52)
* Py_buffer.ndim (C member):             Buffer structure.   (line   98)
* Py_buffer.obj (C member):              Buffer structure.   (line   39)
* Py_buffer.readonly (C member):         Buffer structure.   (line   64)
* Py_buffer.shape (C member):            Buffer structure.   (line  107)
* Py_buffer.strides (C member):          Buffer structure.   (line  120)
* Py_buffer.suboffsets (C member):       Buffer structure.   (line  133)
* Py_BUILD_ASSERT (C macro):             Useful macros.      (line  165)
* Py_BUILD_ASSERT_EXPR (C macro):        Useful macros.      (line  177)
* Py_BuildValue (C function):            Building values.    (line    6)
* Py_BytesMain (C function):             Initializing and finalizing the interpreter.
                                                             (line  126)
* Py_BytesWarningFlag (C var):           Global configuration variables.
                                                             (line   15)
* Py_CHARMASK (C macro):                 Useful macros.      (line   46)
* Py_CLEANUP_SUPPORTED (C macro):        Other objects.      (line   40)
* Py_CLEAR (C function):                 Reference Counting. (line  153)
* Py_CompileString (C function):         The Very High Level Layer.
                                                             (line  229)
* Py_CompileString (C function) <1>:     Available start symbols.
                                                             (line    8)
* Py_CompileString (C function) <2>:     Available start symbols.
                                                             (line   13)
* Py_CompileString (C function) <3>:     Available start symbols.
                                                             (line   20)
* Py_CompileString (C function) <4>:     Available start symbols.
                                                             (line   26)
* Py_CompileStringExFlags (C function):  The Very High Level Layer.
                                                             (line  262)
* Py_CompileStringFlags (C function):    The Very High Level Layer.
                                                             (line  236)
* Py_CompileStringObject (C function):   The Very High Level Layer.
                                                             (line  242)
* Py_complex (C type):                   Complex Numbers as C Structures.
                                                             (line   10)
* Py_complex.imag (C member):            Complex Numbers as C Structures.
                                                             (line   17)
* Py_complex.real (C member):            Complex Numbers as C Structures.
                                                             (line   17)
* Py_CONSTANT_ELLIPSIS (C macro):        Object Protocol.    (line   28)
* Py_CONSTANT_EMPTY_BYTES (C macro):     Object Protocol.    (line   43)
* Py_CONSTANT_EMPTY_STR (C macro):       Object Protocol.    (line   40)
* Py_CONSTANT_EMPTY_TUPLE (C macro):     Object Protocol.    (line   46)
* Py_CONSTANT_FALSE (C macro):           Object Protocol.    (line   22)
* Py_CONSTANT_NONE (C macro):            Object Protocol.    (line   19)
* Py_CONSTANT_NOT_IMPLEMENTED (C macro): Object Protocol.    (line   31)
* Py_CONSTANT_ONE (C macro):             Object Protocol.    (line   37)
* Py_CONSTANT_TRUE (C macro):            Object Protocol.    (line   25)
* Py_CONSTANT_ZERO (C macro):            Object Protocol.    (line   34)
* PY_CXX_CONST (C macro):                API Functions.      (line  115)
* Py_DEBUG (C macro):                    Debugging Builds.   (line   17)
* Py_DEBUG (nel modulo test.support):    test support — Utilities for the Python test suite.
                                                             (line  133)
* Py_DebugFlag (C var):                  Global configuration variables.
                                                             (line   29)
* Py_DecodeLocale (C function):          Operating System Utilities.
                                                             (line  131)
* Py_DECREF (C function):                Reference Counts<2>.
                                                             (line   18)
* Py_DECREF (C function) <1>:            Reference Counting. (line  113)
* Py_DecRef (C function):                Reference Counting. (line  176)
* Py_DEPRECATED (C macro):               Useful macros.      (line   51)
* Py_DontWriteBytecodeFlag (C var):      Global configuration variables.
                                                             (line   43)
* Py_DTSF_ADD_DOT_0 (C macro):           String conversion and formatting.
                                                             (line  135)
* Py_DTSF_ALT (C macro):                 String conversion and formatting.
                                                             (line  139)
* Py_DTSF_NO_NEG_0 (C macro):            String conversion and formatting.
                                                             (line  144)
* Py_DTSF_SIGN (C macro):                String conversion and formatting.
                                                             (line  130)
* Py_DTST_FINITE (C macro):              String conversion and formatting.
                                                             (line  157)
* Py_DTST_INFINITE (C macro):            String conversion and formatting.
                                                             (line  160)
* Py_DTST_NAN (C macro):                 String conversion and formatting.
                                                             (line  163)
* Py_Ellipsis (C var):                   Ellipsis Object.    (line   11)
* Py_EncodeLocale (C function):          Operating System Utilities.
                                                             (line  184)
* Py_END_ALLOW_THREADS (C macro):        Detaching the thread state from extension code.
                                                             (line   19)
* Py_END_ALLOW_THREADS (C macro) <1>:    High-level API.     (line  218)
* Py_END_CRITICAL_SECTION (C macro):     Python Critical Section API.
                                                             (line   97)
* Py_END_CRITICAL_SECTION2 (C macro):    Python Critical Section API.
                                                             (line  144)
* Py_EndInterpreter (C function):        Sub-interpreter support.
                                                             (line  208)
* Py_EnterRecursiveCall (C function):    Recursion Control.  (line   13)
* Py_EQ (C macro):                       PyTypeObject Slots. (line 1275)
* Py_eval_input (C var):                 Available start symbols.
                                                             (line    6)
* Py_Exit (C function):                  Process Control.    (line   22)
* Py_ExitStatusException (C function):   PyStatus.           (line   65)
* Py_EXPORTED_SYMBOL (C macro):          Useful macros.      (line  248)
* Py_False (C var):                      Boolean Objects.    (line   21)
* Py_FatalError (C function):            Process Control.    (line    6)
* Py_FatalError():                       Process-wide parameters.
                                                             (line  225)
* Py_fclose (C function):                Operating System Utilities.
                                                             (line  247)
* Py_FdIsInteractive (C function):       Operating System Utilities.
                                                             (line   18)
* Py_file_input (C var):                 Available start symbols.
                                                             (line   11)
* Py_Finalize (C function):              Initializing and finalizing the interpreter.
                                                             (line  121)
* Py_FinalizeEx (C function):            Process Control.    (line   23)
* Py_FinalizeEx (C function) <1>:        Process Control.    (line   34)
* Py_FinalizeEx (C function) <2>:        Initializing and finalizing the interpreter.
                                                             (line    7)
* Py_FinalizeEx (C function) <3>:        Initializing and finalizing the interpreter.
                                                             (line   64)
* Py_FinalizeEx (C function) <4>:        Sub-interpreter support.
                                                             (line  171)
* Py_FinalizeEx (C function) <5>:        Sub-interpreter support.
                                                             (line  209)
* Py_fopen (C function):                 Operating System Utilities.
                                                             (line  227)
* Py_FrozenFlag (C var):                 Global configuration variables.
                                                             (line   57)
* Py_func_type_input (C var):            Available start symbols.
                                                             (line   24)
* Py_GE (C macro):                       PyTypeObject Slots. (line 1284)
* Py_GenericAlias (C function):          Objects for Type Hinting.
                                                             (line   10)
* Py_GenericAliasType (C var):           Objects for Type Hinting.
                                                             (line   42)
* Py_GetArgcArgv (C function):           Py_GetArgcArgv.     (line    6)
* Py_GetBuildInfo (C function):          Process-wide parameters.
                                                             (line  212)
* Py_GetCompiler (C function):           Process-wide parameters.
                                                             (line  201)
* Py_GetConstant (C function):           Object Protocol.    (line    6)
* Py_GetConstantBorrowed (C function):   Object Protocol.    (line   57)
* Py_GetCopyright (C function):          Process-wide parameters.
                                                             (line  191)
* Py_GETENV (C macro):                   Useful macros.      (line   62)
* Py_GetExecPrefix (C function):         Embedding Python<2>.
                                                             (line   42)
* Py_GetExecPrefix (C function) <1>:     Process-wide parameters.
                                                             (line   71)
* Py_GetPath (C function):               Embedding Python<2>.
                                                             (line   42)
* Py_GetPath (C function) <1>:           Process-wide parameters.
                                                             (line  141)
* Py_GetPath():                          Process-wide parameters.
                                                             (line    7)
* Py_GetPlatform (C function):           Process-wide parameters.
                                                             (line  179)
* Py_GetPrefix (C function):             Embedding Python<2>.
                                                             (line   42)
* Py_GetPrefix (C function) <1>:         Process-wide parameters.
                                                             (line   46)
* Py_GetProgramFullPath (C function):    Embedding Python<2>.
                                                             (line   42)
* Py_GetProgramFullPath (C function) <1>: Process-wide parameters.
                                                             (line  121)
* Py_GetProgramName (C function):        Process-wide parameters.
                                                             (line   30)
* Py_GetPythonHome (C function):         Process-wide parameters.
                                                             (line  315)
* Py_GetRecursionLimit (C function):     Recursion Control.  (line   70)
* Py_GetVersion (C function):            Process-wide parameters.
                                                             (line  165)
* Py_GT (C macro):                       PyTypeObject Slots. (line 1281)
* Py_HASH_ALGORITHM (C macro):           PyHash API.         (line   21)
* Py_HASH_CUTOFF (C macro):              PyHash API.         (line   44)
* Py_HASH_FNV (C macro):                 PyHash API.         (line   31)
* Py_HASH_SIPHASH13 (C macro):           PyHash API.         (line   31)
* Py_HASH_SIPHASH24 (C macro):           PyHash API.         (line   31)
* Py_hash_t (C type):                    PyHash API.         (line    9)
* Py_HashBuffer (C function):            PyHash API.         (line  153)
* Py_HashPointer (C function):           PyHash API.         (line  144)
* Py_HashRandomizationFlag (C var):      Global configuration variables.
                                                             (line   70)
* PY_HAVE_THREAD_NATIVE_ID (C macro):    Operating System Thread APIs.
                                                             (line   50)
* Py_hexdigits (C var):                  Codec utility variables.
                                                             (line    6)
* Py_HUGE_VAL (C macro):                 Floating-Point Objects.
                                                             (line   86)
* Py_IgnoreEnvironmentFlag (C var):      Global configuration variables.
                                                             (line   85)
* Py_IMPORTED_SYMBOL (C macro):          Useful macros.      (line  256)
* Py_INCREF (C function):                Reference Counts<2>.
                                                             (line   18)
* Py_INCREF (C function) <1>:            Reference Counting. (line   51)
* Py_IncRef (C function):                Reference Counting. (line  170)
* Py_INFINITY (C macro):                 Floating-Point Objects.
                                                             (line   70)
* Py_Initialize (C function):            Embedding Python<2>.
                                                             (line   12)
* Py_Initialize (C function) <1>:        Initializing and finalizing the interpreter.
                                                             (line    6)
* Py_Initialize (C function) <2>:        Sub-interpreter support.
                                                             (line  171)
* Py_Initialize():                       Process-wide parameters.
                                                             (line    7)
* Py_InitializeEx (C function):          Initializing and finalizing the interpreter.
                                                             (line   30)
* Py_InitializeFromConfig (C function):  Initializing and finalizing the interpreter.
                                                             (line   40)
* Py_InitializeFromInitConfig (C function): Initialize Python.
                                                             (line    6)
* Py_InspectFlag (C var):                Global configuration variables.
                                                             (line   98)
* Py_InteractiveFlag (C var):            Global configuration variables.
                                                             (line  114)
* PY_INVALID_STACK_EFFECT (C macro):     Stack Effects.      (line   11)
* Py_Is (C function):                    Base object types and macros.
                                                             (line   93)
* Py_IS_FINITE (C macro):                Floating-Point Objects.
                                                             (line  135)
* Py_IS_INFINITY (C macro):              Floating-Point Objects.
                                                             (line  144)
* Py_IS_NAN (C macro):                   Floating-Point Objects.
                                                             (line  152)
* Py_IS_TYPE (C function):               Base object types and macros.
                                                             (line  132)
* Py_ISALNUM (C macro):                  Character classification and conversion.
                                                             (line   10)
* Py_ISALPHA (C macro):                  Character classification and conversion.
                                                             (line   14)
* Py_ISDIGIT (C macro):                  Character classification and conversion.
                                                             (line   19)
* Py_IsFalse (C function):               Base object types and macros.
                                                             (line  113)
* Py_IsFinalizing (C function):          Initializing and finalizing the interpreter.
                                                             (line   57)
* Py_IsInitialized (C function):         Embedding Python<2>.
                                                             (line   51)
* Py_IsInitialized (C function) <1>:     Initializing and finalizing the interpreter.
                                                             (line   51)
* Py_ISLOWER (C macro):                  Character classification and conversion.
                                                             (line   23)
* Py_IsNone (C function):                Base object types and macros.
                                                             (line   99)
* Py_IsolatedFlag (C var):               Global configuration variables.
                                                             (line  124)
* Py_ISSPACE (C macro):                  Character classification and conversion.
                                                             (line   33)
* Py_IsTrue (C function):                Base object types and macros.
                                                             (line  106)
* Py_ISUPPER (C macro):                  Character classification and conversion.
                                                             (line   28)
* Py_ISXDIGIT (C macro):                 Character classification and conversion.
                                                             (line   38)
* Py_LE (C macro):                       PyTypeObject Slots. (line 1272)
* Py_LeaveRecursiveCall (C function):    Recursion Control.  (line   34)
* Py_LegacyWindowsFSEncodingFlag (C var): Global configuration variables.
                                                             (line  140)
* Py_LegacyWindowsStdioFlag (C var):     Global configuration variables.
                                                             (line  160)
* Py_LIMITED_API (C macro):              Limited C API.      (line   11)
* Py_LOCAL (C macro):                    Useful macros.      (line   67)
* Py_LOCAL_INLINE (C macro):             Useful macros.      (line   73)
* Py_LOCAL_SYMBOL (C macro):             Useful macros.      (line   78)
* PY_LOCK_ACQUIRED (C enumerator):       Legacy Locking APIs.
                                                             (line   24)
* PY_LOCK_FAILURE (C enumerator):        Legacy Locking APIs.
                                                             (line   20)
* PY_LOCK_INTR (C enumerator):           Legacy Locking APIs.
                                                             (line   28)
* Py_LT (C macro):                       PyTypeObject Slots. (line 1269)
* Py_Main (C function):                  Initializing and finalizing the interpreter.
                                                             (line  134)
* PY_MAJOR_VERSION (C macro):            Build-time version constants.
                                                             (line   13)
* Py_MakePendingCalls (C function):      Asynchronous Notifications.
                                                             (line   56)
* Py_MARSHAL_VERSION (C macro):          Data marshalling support.
                                                             (line   17)
* Py_MATH_E (C macro):                   Floating-Point Objects.
                                                             (line   93)
* Py_MATH_El (C macro):                  Floating-Point Objects.
                                                             (line   98)
* Py_MATH_PI (C macro):                  Floating-Point Objects.
                                                             (line  102)
* Py_MATH_PIl (C macro):                 Floating-Point Objects.
                                                             (line  107)
* Py_MATH_TAU (C macro):                 Floating-Point Objects.
                                                             (line  112)
* Py_MAX (C macro):                      Useful macros.      (line   87)
* Py_MEMBER_SIZE (C macro):              Useful macros.      (line   93)
* Py_MEMCPY (C macro):                   Useful macros.      (line   99)
* PY_MICRO_VERSION (C macro):            Build-time version constants.
                                                             (line   21)
* Py_MIN (C macro):                      Useful macros.      (line  107)
* PY_MINOR_VERSION (C macro):            Build-time version constants.
                                                             (line   17)
* Py_mod_create (C macro):               Module slots.       (line   21)
* Py_mod_exec (C macro):                 Module slots.       (line   57)
* Py_mod_gil (C macro):                  Module slots.       (line  102)
* Py_MOD_GIL_NOT_USED (C macro):         Module slots.       (line  112)
* Py_MOD_GIL_USED (C macro):             Module slots.       (line  106)
* Py_mod_multiple_interpreters (C macro): Module slots.      (line   71)
* Py_MOD_MULTIPLE_INTERPRETERS_NOT_SUPPORTED (C macro): Module slots.
                                                             (line   75)
* Py_MOD_MULTIPLE_INTERPRETERS_SUPPORTED (C macro): Module slots.
                                                             (line   79)
* Py_MOD_PER_INTERPRETER_GIL_SUPPORTED (C macro): Module slots.
                                                             (line   85)
* PY_MONITORING_EVENT_BRANCH_LEFT (C macro): Managing the Monitoring State.
                                                             (line   44)
* PY_MONITORING_EVENT_BRANCH_RIGHT (C macro): Managing the Monitoring State.
                                                             (line   47)
* PY_MONITORING_EVENT_C_RAISE (C macro): Managing the Monitoring State.
                                                             (line   53)
* PY_MONITORING_EVENT_C_RETURN (C macro): Managing the Monitoring State.
                                                             (line   56)
* PY_MONITORING_EVENT_CALL (C macro):    Managing the Monitoring State.
                                                             (line   50)
* PY_MONITORING_EVENT_EXCEPTION_HANDLED (C macro): Managing the Monitoring State.
                                                             (line   59)
* PY_MONITORING_EVENT_INSTRUCTION (C macro): Managing the Monitoring State.
                                                             (line   62)
* PY_MONITORING_EVENT_JUMP (C macro):    Managing the Monitoring State.
                                                             (line   65)
* PY_MONITORING_EVENT_LINE (C macro):    Managing the Monitoring State.
                                                             (line   68)
* PY_MONITORING_EVENT_PY_RESUME (C macro): Managing the Monitoring State.
                                                             (line   71)
* PY_MONITORING_EVENT_PY_RETURN (C macro): Managing the Monitoring State.
                                                             (line   74)
* PY_MONITORING_EVENT_PY_START (C macro): Managing the Monitoring State.
                                                             (line   77)
* PY_MONITORING_EVENT_PY_THROW (C macro): Managing the Monitoring State.
                                                             (line   80)
* PY_MONITORING_EVENT_PY_UNWIND (C macro): Managing the Monitoring State.
                                                             (line   83)
* PY_MONITORING_EVENT_PY_YIELD (C macro): Managing the Monitoring State.
                                                             (line   86)
* PY_MONITORING_EVENT_RAISE (C macro):   Managing the Monitoring State.
                                                             (line   89)
* PY_MONITORING_EVENT_RERAISE (C macro): Managing the Monitoring State.
                                                             (line   92)
* PY_MONITORING_EVENT_STOP_ITERATION (C macro): Managing the Monitoring State.
                                                             (line   95)
* PY_MONITORING_IS_INSTRUMENTED_EVENT (C function): Managing the Monitoring State.
                                                             (line  103)
* Py_mp_ass_subscript (C macro):         Mapping Object Structures.
                                                             (line   37)
* Py_mp_length (C macro):                Mapping Object Structures.
                                                             (line   15)
* Py_mp_subscript (C macro):             Mapping Object Structures.
                                                             (line   25)
* Py_NAN (C macro):                      Floating-Point Objects.
                                                             (line   78)
* Py_nb_absolute (C macro):              Number Object Structures.
                                                             (line  121)
* Py_nb_add (C macro):                   Number Object Structures.
                                                             (line   73)
* Py_nb_and (C macro):                   Number Object Structures.
                                                             (line  149)
* Py_nb_bool (C macro):                  Number Object Structures.
                                                             (line  126)
* Py_nb_divmod (C macro):                Number Object Structures.
                                                             (line   97)
* Py_nb_float (C macro):                 Number Object Structures.
                                                             (line  172)
* Py_nb_floor_divide (C macro):          Number Object Structures.
                                                             (line  238)
* Py_nb_index (C macro):                 Number Object Structures.
                                                             (line  263)
* Py_nb_inplace_add (C macro):           Number Object Structures.
                                                             (line  178)
* Py_nb_inplace_and (C macro):           Number Object Structures.
                                                             (line  220)
* Py_nb_inplace_floor_divide (C macro):  Number Object Structures.
                                                             (line  251)
* Py_nb_inplace_lshift (C macro):        Number Object Structures.
                                                             (line  208)
* Py_nb_inplace_matrix_multiply (C macro): Number Object Structures.
                                                             (line  276)
* Py_nb_inplace_multiply (C macro):      Number Object Structures.
                                                             (line  190)
* Py_nb_inplace_or (C macro):            Number Object Structures.
                                                             (line  232)
* Py_nb_inplace_power (C macro):         Number Object Structures.
                                                             (line  202)
* Py_nb_inplace_remainder (C macro):     Number Object Structures.
                                                             (line  196)
* Py_nb_inplace_rshift (C macro):        Number Object Structures.
                                                             (line  214)
* Py_nb_inplace_subtract (C macro):      Number Object Structures.
                                                             (line  184)
* Py_nb_inplace_true_divide (C macro):   Number Object Structures.
                                                             (line  258)
* Py_nb_inplace_xor (C macro):           Number Object Structures.
                                                             (line  226)
* Py_nb_int (C macro):                   Number Object Structures.
                                                             (line  164)
* Py_nb_invert (C macro):                Number Object Structures.
                                                             (line  132)
* Py_nb_lshift (C macro):                Number Object Structures.
                                                             (line  138)
* Py_nb_matrix_multiply (C macro):       Number Object Structures.
                                                             (line  269)
* Py_nb_multiply (C macro):              Number Object Structures.
                                                             (line   85)
* Py_nb_negative (C macro):              Number Object Structures.
                                                             (line  109)
* Py_nb_or (C macro):                    Number Object Structures.
                                                             (line  159)
* Py_nb_positive (C macro):              Number Object Structures.
                                                             (line  115)
* Py_nb_power (C macro):                 Number Object Structures.
                                                             (line  103)
* Py_nb_remainder (C macro):             Number Object Structures.
                                                             (line   91)
* Py_nb_rshift (C macro):                Number Object Structures.
                                                             (line  144)
* Py_nb_subtract (C macro):              Number Object Structures.
                                                             (line   79)
* Py_nb_true_divide (C macro):           Number Object Structures.
                                                             (line  244)
* Py_nb_xor (C macro):                   Number Object Structures.
                                                             (line  154)
* Py_NE (C macro):                       PyTypeObject Slots. (line 1278)
* Py_NewInterpreter (C function):        Sub-interpreter support.
                                                             (line  198)
* Py_NewInterpreterFromConfig (C function): Sub-interpreter support.
                                                             (line  109)
* Py_NewRef (C function):                Reference Counting. (line   81)
* Py_NO_INLINE (C macro):                Useful macros.      (line  113)
* Py_NO_LINK_LIB (C macro):              Differences Between Unix and Windows.
                                                             (line   55)
* Py_None (C var):                       The None Object.    (line   11)
* Py_NoSiteFlag (C var):                 Global configuration variables.
                                                             (line  178)
* Py_NotImplemented (C var):             Object Protocol.    (line   71)
* Py_NoUserSiteDirectory (C var):        Global configuration variables.
                                                             (line  194)
* py_object (classe in ctypes):          Fundamental data types<2>.
                                                             (line  241)
* Py_OpenCodeHookFunction (C type):      File Objects.       (line   65)
* Py_OptimizeFlag (C var):               Global configuration variables.
                                                             (line  208)
* Py_PACK_FULL_VERSION (C function):     Bit-packing macros. (line    6)
* Py_PACK_VERSION (C function):          Bit-packing macros. (line   64)
* Py_PreInitialize (C function):         Preinitialize Python with PyPreConfig.
                                                             (line   21)
* Py_PreInitializeFromArgs (C function): Preinitialize Python with PyPreConfig.
                                                             (line   38)
* Py_PreInitializeFromBytesArgs (C function): Preinitialize Python with PyPreConfig.
                                                             (line   28)
* Py_PRINT_RAW (C macro):                Object Protocol.    (line   82)
* Py_PRINT_RAW (C macro) <1>:            File Objects.       (line  117)
* Py_QuietFlag (C var):                  Global configuration variables.
                                                             (line  219)
* Py_READONLY (C macro):                 Member flags.       (line    8)
* Py_REFCNT (C function):                Reference Counting. (line    9)
* Py_RELATIVE_OFFSET (C macro):          Member flags.       (line   16)
* PY_RELEASE_LEVEL (C macro):            Build-time version constants.
                                                             (line   25)
* PY_RELEASE_SERIAL (C macro):           Build-time version constants.
                                                             (line   30)
* Py_REMOTE_DEBUG (C macro):             Performance options.
                                                             (line  157)
* Py_ReprEnter (C function):             Recursion Control.  (line   48)
* Py_ReprLeave (C function):             Recursion Control.  (line   65)
* PY_RESUME (monitoring event):          Events.             (line   52)
* PY_RETURN (monitoring event):          Events.             (line   57)
* Py_RETURN_FALSE (C macro):             Boolean Objects.    (line   37)
* Py_RETURN_INF (C macro):               Floating-Point Objects.
                                                             (line  126)
* Py_RETURN_NAN (C macro):               Floating-Point Objects.
                                                             (line  119)
* Py_RETURN_NONE (C macro):              The None Object.    (line   19)
* Py_RETURN_NOTIMPLEMENTED (C macro):    Object Protocol.    (line   76)
* Py_RETURN_RICHCOMPARE (C macro):       PyTypeObject Slots. (line 1290)
* Py_RETURN_TRUE (C macro):              Boolean Objects.    (line   41)
* Py_RunMain (C function):               Initializing and finalizing the interpreter.
                                                             (line  182)
* Py_SET_REFCNT (C function):            Reference Counting. (line   38)
* Py_SET_SIZE (C function):              Base object types and macros.
                                                             (line  165)
* Py_SET_TYPE (C function):              Base object types and macros.
                                                             (line  139)
* Py_SetProgramName (C function):        Process-wide parameters.
                                                             (line    6)
* Py_SetPythonHome (C function):         Process-wide parameters.
                                                             (line  296)
* Py_SetRecursionLimit (C function):     Recursion Control.  (line   84)
* Py_SETREF (C macro):                   Reference Counting. (line  182)
* Py_single_input (C var):               Available start symbols.
                                                             (line   18)
* Py_SIZE (C function):                  Base object types and macros.
                                                             (line  157)
* Py_sq_ass_item (C macro):              Sequence Object Structures.
                                                             (line   66)
* Py_sq_concat (C macro):                Sequence Object Structures.
                                                             (line   26)
* Py_sq_contains (C macro):              Sequence Object Structures.
                                                             (line   79)
* Py_sq_inplace_concat (C macro):        Sequence Object Structures.
                                                             (line   90)
* Py_sq_inplace_repeat (C macro):        Sequence Object Structures.
                                                             (line  104)
* Py_sq_item (C macro):                  Sequence Object Structures.
                                                             (line   47)
* Py_sq_length (C macro):                Sequence Object Structures.
                                                             (line   15)
* Py_sq_repeat (C macro):                Sequence Object Structures.
                                                             (line   36)
* Py_ssize_t (C type):                   Types<2>.           (line   14)
* PY_SSIZE_T_MAX (C macro):              Integer Objects.    (line  268)
* PY_START (monitoring event):           Events.             (line   62)
* Py_STRINGIFY (C macro):                Useful macros.      (line  125)
* Py_T_BOOL (C macro):                   Member types.       (line   85)
* Py_T_BYTE (C macro):                   Member types.       (line   20)
* Py_T_CHAR (C macro):                   Member types.       (line  100)
* Py_T_DOUBLE (C macro):                 Member types.       (line   80)
* Py_T_FLOAT (C macro):                  Member types.       (line   75)
* Py_T_INT (C macro):                    Member types.       (line   30)
* Py_T_LONG (C macro):                   Member types.       (line   35)
* Py_T_LONGLONG (C macro):               Member types.       (line   40)
* Py_T_OBJECT_EX (C macro):              Member types.       (line  105)
* Py_T_PYSSIZET (C macro):               Member types.       (line   70)
* Py_T_SHORT (C macro):                  Member types.       (line   25)
* Py_T_STRING (C macro):                 Member types.       (line   90)
* Py_T_STRING_INPLACE (C macro):         Member types.       (line   95)
* Py_T_UBYTE (C macro):                  Member types.       (line   45)
* Py_T_UINT (C macro):                   Member types.       (line   50)
* Py_T_ULONG (C macro):                  Member types.       (line   60)
* Py_T_ULONGLONG (C macro):              Member types.       (line   65)
* Py_T_USHORT (C macro):                 Member types.       (line   55)
* PY_THROW (monitoring event):           Events.             (line   67)
* Py_TOLOWER (C macro):                  Character classification and conversion.
                                                             (line   43)
* Py_TOUPPER (C macro):                  Character classification and conversion.
                                                             (line   47)
* Py_tp_alloc (C macro):                 PyTypeObject Slots. (line 1652)
* Py_tp_base (C macro):                  PyTypeObject Slots. (line 1463)
* Py_tp_bases (C macro):                 PyTypeObject Slots. (line 1783)
* Py_tp_call (C macro):                  PyTypeObject Slots. (line  495)
* Py_tp_clear (C macro):                 PyTypeObject Slots. (line 1086)
* Py_tp_dealloc (C macro):               PyTypeObject Slots. (line  137)
* Py_tp_del (C macro):                   PyTypeObject Slots. (line 1859)
* Py_tp_descr_get (C macro):             PyTypeObject Slots. (line 1535)
* Py_tp_descr_set (C macro):             PyTypeObject Slots. (line 1551)
* Py_tp_doc (C macro):                   PyTypeObject Slots. (line  968)
* Py_tp_finalize (C macro):              PyTypeObject Slots. (line 1875)
* Py_tp_free (C macro):                  PyTypeObject Slots. (line 1719)
* Py_tp_getattr (C macro):               PyTypeObject Slots. (line  323)
* Py_tp_getattro (C macro):              PyTypeObject Slots. (line  540)
* Py_tp_getset (C macro):                PyTypeObject Slots. (line 1445)
* Py_tp_hash (C macro):                  PyTypeObject Slots. (line  450)
* Py_tp_init (C macro):                  PyTypeObject Slots. (line 1613)
* Py_tp_is_gc (C macro):                 PyTypeObject Slots. (line 1751)
* Py_tp_iter (C macro):                  PyTypeObject Slots. (line 1361)
* Py_tp_iternext (C macro):              PyTypeObject Slots. (line 1381)
* Py_tp_members (C macro):               PyTypeObject Slots. (line 1426)
* Py_tp_methods (C macro):               PyTypeObject Slots. (line 1407)
* Py_tp_new (C macro):                   PyTypeObject Slots. (line 1677)
* Py_tp_repr (C macro):                  PyTypeObject Slots. (line  385)
* Py_tp_richcompare (C macro):           PyTypeObject Slots. (line 1246)
* Py_tp_setattr (C macro):               PyTypeObject Slots. (line  346)
* Py_tp_setattro (C macro):              PyTypeObject Slots. (line  570)
* Py_tp_str (C macro):                   PyTypeObject Slots. (line  510)
* Py_tp_token (C macro):                 Creating Heap-Allocated Types.
                                                             (line  279)
* Py_tp_traverse (C macro):              PyTypeObject Slots. (line  982)
* Py_TP_USE_SPEC (C macro):              Creating Heap-Allocated Types.
                                                             (line  308)
* Py_tp_vectorcall (C macro):            PyTypeObject Slots. (line 2045)
* Py_TPFLAGS_BASE_EXC_SUBCLASS (C macro): PyTypeObject Slots.
                                                             (line  818)
* Py_TPFLAGS_BASETYPE (C macro):         PyTypeObject Slots. (line  668)
* Py_TPFLAGS_BYTES_SUBCLASS (C macro):   PyTypeObject Slots. (line  812)
* Py_TPFLAGS_DEFAULT (C macro):          PyTypeObject Slots. (line  718)
* Py_TPFLAGS_DICT_SUBCLASS (C macro):    PyTypeObject Slots. (line  816)
* Py_TPFLAGS_DISALLOW_INSTANTIATION (C macro): PyTypeObject Slots.
                                                             (line  880)
* Py_TPFLAGS_HAVE_FINALIZE (C macro):    PyTypeObject Slots. (line  831)
* Py_TPFLAGS_HAVE_GC (C macro):          PyTypeObject Slots. (line  696)
* Py_TPFLAGS_HAVE_VECTORCALL (C macro):  PyTypeObject Slots. (line  842)
* Py_TPFLAGS_HEAPTYPE (C macro):         PyTypeObject Slots. (line  650)
* Py_TPFLAGS_IMMUTABLETYPE (C macro):    PyTypeObject Slots. (line  866)
* Py_TPFLAGS_ITEMS_AT_END (C macro):     PyTypeObject Slots. (line  786)
* Py_TPFLAGS_LIST_SUBCLASS (C macro):    PyTypeObject Slots. (line  808)
* Py_TPFLAGS_LONG_SUBCLASS (C macro):    PyTypeObject Slots. (line  806)
* Py_TPFLAGS_MANAGED_DICT (C macro):     PyTypeObject Slots. (line  754)
* Py_TPFLAGS_MANAGED_WEAKREF (C macro):  PyTypeObject Slots. (line  774)
* Py_TPFLAGS_MAPPING (C macro):          PyTypeObject Slots. (line  908)
* Py_TPFLAGS_METHOD_DESCRIPTOR (C macro): PyTypeObject Slots.
                                                             (line  729)
* Py_TPFLAGS_READY (C macro):            PyTypeObject Slots. (line  678)
* Py_TPFLAGS_READYING (C macro):         PyTypeObject Slots. (line  687)
* Py_TPFLAGS_SEQUENCE (C macro):         PyTypeObject Slots. (line  932)
* Py_TPFLAGS_TUPLE_SUBCLASS (C macro):   PyTypeObject Slots. (line  810)
* Py_TPFLAGS_TYPE_SUBCLASS (C macro):    PyTypeObject Slots. (line  820)
* Py_TPFLAGS_UNICODE_SUBCLASS (C macro): PyTypeObject Slots. (line  814)
* Py_TPFLAGS_VALID_VERSION_TAG (C macro): PyTypeObject Slots.
                                                             (line  956)
* Py_tracefunc (C type):                 Profiling and Tracing.
                                                             (line   18)
* Py_True (C var):                       Boolean Objects.    (line   29)
* Py_tss_NEEDS_INIT (C macro):           Thread Specific Storage TSS API.
                                                             (line   28)
* Py_tss_t (C type):                     Thread Specific Storage TSS API.
                                                             (line   17)
* Py_TYPE (C function):                  Base object types and macros.
                                                             (line  120)
* Py_UCS1 (C type):                      Unicode Type.       (line   19)
* Py_UCS2 (C type):                      Unicode Type.       (line   19)
* Py_UCS4 (C type):                      Unicode Type.       (line   19)
* Py_uhash_t (C type):                   PyHash API.         (line   15)
* Py_UNBLOCK_THREADS (C macro):          High-level API.     (line  230)
* Py_UnbufferedStdioFlag (C var):        Global configuration variables.
                                                             (line  234)
* Py_UNICODE (C type):                   Deprecated API<2>.  (line    8)
* Py_UNICODE_HIGH_SURROGATE (C function): Unicode Character Properties.
                                                             (line  107)
* Py_UNICODE_IS_HIGH_SURROGATE (C function): Unicode Character Properties.
                                                             (line   99)
* Py_UNICODE_IS_LOW_SURROGATE (C function): Unicode Character Properties.
                                                             (line  103)
* Py_UNICODE_IS_SURROGATE (C function):  Unicode Character Properties.
                                                             (line   95)
* Py_UNICODE_ISALNUM (C function):       Unicode Character Properties.
                                                             (line   52)
* Py_UNICODE_ISALPHA (C function):       Unicode Character Properties.
                                                             (line   47)
* Py_UNICODE_ISDECIMAL (C function):     Unicode Character Properties.
                                                             (line   35)
* Py_UNICODE_ISDIGIT (C function):       Unicode Character Properties.
                                                             (line   39)
* Py_UNICODE_ISLINEBREAK (C function):   Unicode Character Properties.
                                                             (line   30)
* Py_UNICODE_ISLOWER (C function):       Unicode Character Properties.
                                                             (line   15)
* Py_UNICODE_ISNUMERIC (C function):     Unicode Character Properties.
                                                             (line   43)
* Py_UNICODE_ISPRINTABLE (C function):   Unicode Character Properties.
                                                             (line   57)
* Py_UNICODE_ISSPACE (C function):       Unicode Character Properties.
                                                             (line   10)
* Py_UNICODE_ISTITLE (C function):       Unicode Character Properties.
                                                             (line   25)
* Py_UNICODE_ISUPPER (C function):       Unicode Character Properties.
                                                             (line   20)
* Py_UNICODE_JOIN_SURROGATES (C function): Unicode Character Properties.
                                                             (line  119)
* Py_UNICODE_LOW_SURROGATE (C function): Unicode Character Properties.
                                                             (line  113)
* Py_UNICODE_REPLACEMENT_CHARACTER (C macro): Generic Codecs.
                                                             (line    8)
* Py_UNICODE_TODECIMAL (C function):     Unicode Character Properties.
                                                             (line   76)
* Py_UNICODE_TODIGIT (C function):       Unicode Character Properties.
                                                             (line   82)
* Py_UNICODE_TOLOWER (C function):       Unicode Character Properties.
                                                             (line   64)
* Py_UNICODE_TONUMERIC (C function):     Unicode Character Properties.
                                                             (line   88)
* Py_UNICODE_TOTITLE (C function):       Unicode Character Properties.
                                                             (line   72)
* Py_UNICODE_TOUPPER (C function):       Unicode Character Properties.
                                                             (line   68)
* Py_UNREACHABLE (C macro):              Useful macros.      (line  132)
* Py_UNUSED (C macro):                   Useful macros.      (line  157)
* PY_UNWIND (monitoring event):          Events.             (line   71)
* Py_VaBuildValue (C function):          Building values.    (line  214)
* PY_VECTORCALL_ARGUMENTS_OFFSET (C macro): The Vectorcall Protocol.
                                                             (line   69)
* Py_VerboseFlag (C var):                Global configuration variables.
                                                             (line  247)
* Py_Version (C var):                    Run-time version.   (line    6)
* PY_VERSION_HEX (C macro):              Build-time version constants.
                                                             (line   34)
* Py_VISIT (C macro):                    Supporting Cyclic Garbage Collection.
                                                             (line  253)
* Py_XDECREF (C function):               Exceptions<23>.     (line  123)
* Py_XDECREF (C function) <1>:           Reference Counting. (line  147)
* Py_XINCREF (C function):               Reference Counting. (line   74)
* Py_XNewRef (C function):               Reference Counting. (line  105)
* Py_XSETREF (C macro):                  Reference Counting. (line  208)
* PY_YIELD (monitoring event):           Events.             (line   77)
* PyAIter_Check (C function):            Iterator Protocol.  (line   14)
* PyAnySet_Check (C function):           Set Objects.        (line   54)
* PyAnySet_CheckExact (C function):      Set Objects.        (line   67)
* PyAPI_DATA (C macro):                  Useful macros.      (line  269)
* PyAPI_FUNC (C macro):                  Useful macros.      (line  262)
* PyArg_Parse (C function):              API Functions.      (line   55)
* PyArg_ParseTuple (C function):         Extracting Parameters in Extension Functions.
                                                             (line    6)
* PyArg_ParseTuple (C function) <1>:     API Functions.      (line    6)
* PyArg_ParseTupleAndKeywords (C function): Keyword Parameters for Extension Functions.
                                                             (line    6)
* PyArg_ParseTupleAndKeywords (C function) <1>: API Functions.
                                                             (line   19)
* PyArg_UnpackTuple (C function):        API Functions.      (line   75)
* PyArg_ValidateKeywordArguments (C function): API Functions.
                                                             (line   47)
* PyArg_VaParse (C function):            API Functions.      (line   13)
* PyArg_VaParseTupleAndKeywords (C function): API Functions. (line   40)
* PyASCIIObject (C type):                Unicode Type.       (line   29)
* PyAsyncGen_CheckExact (C function):    Asynchronous Generator Objects.
                                                             (line   32)
* PyAsyncGen_New (C function):           Asynchronous Generator Objects.
                                                             (line   19)
* PyAsyncGen_Type (C var):               Asynchronous Generator Objects.
                                                             (line   11)
* PyAsyncGenASend_CheckExact (C macro):  Deprecated API<5>.  (line    6)
* PyAsyncMethods (C type):               Async Object Structures.
                                                             (line    8)
* PyAsyncMethods.am_aiter (C member):    Async Object Structures.
                                                             (line   38)
* PyAsyncMethods.am_anext (C member):    Async Object Structures.
                                                             (line   53)
* PyAsyncMethods.am_await (C member):    Async Object Structures.
                                                             (line   23)
* PyAsyncMethods.am_send (C member):     Async Object Structures.
                                                             (line   65)
* PyBaseObject_Type (C var):             Base object types and macros.
                                                             (line   89)
* PyBool_Check (C function):             Boolean Objects.    (line   16)
* PyBool_FromLong (C function):          Boolean Objects.    (line   45)
* PyBool_Type (C var):                   Boolean Objects.    (line   11)
* PyBUF_ANY_CONTIGUOUS (C macro):        contiguity requests.
                                                             (line   24)
* PyBUF_C_CONTIGUOUS (C macro):          contiguity requests.
                                                             (line   14)
* PyBUF_CONTIG (C macro):                compound requests.  (line   48)
* PyBUF_CONTIG_RO (C macro):             compound requests.  (line   53)
* PyBUF_F_CONTIGUOUS (C macro):          contiguity requests.
                                                             (line   19)
* PyBUF_FORMAT (C macro):                readonly format.    (line   21)
* PyBUF_FULL (C macro):                  compound requests.  (line   18)
* PyBUF_FULL_RO (C macro):               compound requests.  (line   23)
* PyBUF_INDIRECT (C macro):              shape strides suboffsets.
                                                             (line   14)
* PyBUF_MAX_NDIM (C macro):              Buffer structure.   (line  162)
* PyBUF_ND (C macro):                    shape strides suboffsets.
                                                             (line   24)
* PyBUF_READ (C macro):                  MemoryView objects. (line   24)
* PyBUF_RECORDS (C macro):               compound requests.  (line   28)
* PyBUF_RECORDS_RO (C macro):            compound requests.  (line   33)
* PyBUF_SIMPLE (C macro):                shape strides suboffsets.
                                                             (line   29)
* PyBUF_STRIDED (C macro):               compound requests.  (line   38)
* PyBUF_STRIDED_RO (C macro):            compound requests.  (line   43)
* PyBUF_STRIDES (C macro):               shape strides suboffsets.
                                                             (line   19)
* PyBUF_WRITABLE (C macro):              readonly format.    (line    6)
* PyBUF_WRITE (C macro):                 MemoryView objects. (line   28)
* PyBUF_WRITEABLE (C macro):             readonly format.    (line   16)
* PyBuffer_FillContiguousStrides (C function): Buffer-related functions.
                                                             (line   87)
* PyBuffer_FillInfo (C function):        Buffer-related functions.
                                                             (line   96)
* PyBuffer_FromContiguous (C function):  Buffer-related functions.
                                                             (line   63)
* PyBuffer_GetPointer (C function):      Buffer-related functions.
                                                             (line   57)
* PyBuffer_IsContiguous (C function):    Buffer-related functions.
                                                             (line   49)
* PyBuffer_Release (C function):         Buffer-related functions.
                                                             (line   31)
* PyBuffer_SizeFromFormat (C function):  Buffer-related functions.
                                                             (line   41)
* PyBuffer_ToContiguous (C function):    Buffer-related functions.
                                                             (line   70)
* PyBufferProcs (C type):                Buffer Protocol.    (line   20)
* PyBufferProcs (C type) <1>:            Buffer Object Structures.
                                                             (line    6)
* PyBufferProcs.bf_getbuffer (C member): Buffer Object Structures.
                                                             (line   12)
* PyBufferProcs.bf_releasebuffer (C member): Buffer Object Structures.
                                                             (line   63)
* PyByteArray_AS_STRING (C function):    Macros.             (line    8)
* PyByteArray_AsString (C function):     Direct API functions.
                                                             (line   35)
* PyByteArray_Check (C function):        Type check macros.  (line    6)
* PyByteArray_CheckExact (C function):   Type check macros.  (line   11)
* PyByteArray_Concat (C function):       Direct API functions.
                                                             (line   22)
* PyByteArray_FromObject (C function):   Direct API functions.
                                                             (line    6)
* PyByteArray_FromStringAndSize (C function): Direct API functions.
                                                             (line   14)
* PyByteArray_GET_SIZE (C function):     Macros.             (line   13)
* PyByteArray_Resize (C function):       Direct API functions.
                                                             (line   40)
* PyByteArray_Size (C function):         Direct API functions.
                                                             (line   30)
* PyByteArray_Type (C var):              Byte Array Objects. (line   11)
* PyByteArrayIter_Type (C var):          Other Iterator Objects.
                                                             (line    6)
* PyByteArrayObject (C type):            Byte Array Objects. (line    6)
* PyBytes_AS_STRING (C function):        Bytes Objects.      (line  139)
* PyBytes_AsString (C function):         Bytes Objects.      (line  128)
* PyBytes_AsStringAndSize (C function):  Bytes Objects.      (line  144)
* PyBytes_Check (C function):            Bytes Objects.      (line   19)
* PyBytes_CheckExact (C function):       Bytes Objects.      (line   24)
* PyBytes_Concat (C function):           Bytes Objects.      (line  166)
* PyBytes_ConcatAndDel (C function):     Bytes Objects.      (line  176)
* PyBytes_DecodeEscape (C function):     Bytes Objects.      (line  233)
* PyBytes_FromFormat (C function):       Bytes Objects.      (line   44)
* PyBytes_FromFormatV (C function):      Bytes Objects.      (line  109)
* PyBytes_FromObject (C function):       Bytes Objects.      (line  115)
* PyBytes_FromString (C function):       Bytes Objects.      (line   30)
* PyBytes_FromStringAndSize (C function): Bytes Objects.     (line   36)
* PyBytes_GET_SIZE (C function):         Bytes Objects.      (line  124)
* PyBytes_Join (C function):             Bytes Objects.      (line  183)
* PyBytes_Repr (C function):             Bytes Objects.      (line  214)
* PyBytes_Size (C function):             Bytes Objects.      (line  120)
* PyBytes_Type (C var):                  Bytes Objects.      (line   14)
* PyBytesIter_Type (C var):              Other Iterator Objects.
                                                             (line    9)
* PyBytesObject (C type):                Bytes Objects.      (line    9)
* pycache_prefix (nel modulo sys):       sys — System-specific parameters and functions.
                                                             (line  371)
* PyCallable_Check (C function):         Call Support API.   (line    6)
* PyCallIter_Check (C function):         Iterator Objects.   (line   34)
* PyCallIter_New (C function):           Iterator Objects.   (line   39)
* PyCallIter_Type (C var):               Iterator Objects.   (line   29)
* PyCapsule (C type):                    Capsules<2>.        (line   11)
* PyCapsule_CheckExact (C function):     Capsules<2>.        (line   34)
* PyCapsule_Destructor (C type):         Capsules<2>.        (line   25)
* PyCapsule_GetContext (C function):     Capsules<2>.        (line   80)
* PyCapsule_GetDestructor (C function):  Capsules<2>.        (line   69)
* PyCapsule_GetName (C function):        Capsules<2>.        (line   90)
* PyCapsule_GetPointer (C function):     Capsules<2>.        (line   59)
* PyCapsule_Import (C function):         Capsules<2>.        (line  100)
* PyCapsule_IsValid (C function):        Capsules<2>.        (line  122)
* PyCapsule_New (C function):            Capsules<2>.        (line   39)
* PyCapsule_SetContext (C function):     Capsules<2>.        (line  138)
* PyCapsule_SetDestructor (C function):  Capsules<2>.        (line  146)
* PyCapsule_SetName (C function):        Capsules<2>.        (line  154)
* PyCapsule_SetPointer (C function):     Capsules<2>.        (line  164)
* PyCapsule_Type (C var):                Capsules<2>.        (line   20)
* PyCell_Check (C function):             Cell Objects.       (line   24)
* PyCell_Get (C function):               Cell Objects.       (line   34)
* PyCell_GET (C function):               Cell Objects.       (line   39)
* PyCell_New (C function):               Cell Objects.       (line   29)
* PyCell_Set (C function):               Cell Objects.       (line   44)
* PyCell_SET (C function):               Cell Objects.       (line   53)
* PyCell_Type (C var):                   Cell Objects.       (line   20)
* PyCellObject (C type):                 Cell Objects.       (line   16)
* PyCF_ALLOW_TOP_LEVEL_AWAIT (C macro):  The Very High Level Layer.
                                                             (line  346)
* PyCF_ALLOW_TOP_LEVEL_AWAIT (nel modulo ast): Compiler flags<2>.
                                                             (line    9)
* PyCF_ONLY_AST (C macro):               The Very High Level Layer.
                                                             (line  346)
* PyCF_ONLY_AST (nel modulo ast):        Compiler flags<2>.  (line   16)
* PyCF_OPTIMIZED_AST (C macro):          The Very High Level Layer.
                                                             (line  346)
* PyCF_OPTIMIZED_AST (nel modulo ast):   Compiler flags<2>.  (line   21)
* PyCF_TYPE_COMMENTS (C macro):          The Very High Level Layer.
                                                             (line  346)
* PyCF_TYPE_COMMENTS (nel modulo ast):   Compiler flags<2>.  (line   28)
* PyCFunction (C type):                  Implementing functions and methods.
                                                             (line    6)
* PyCFunction_Check (C function):        Implementing functions and methods.
                                                             (line  274)
* PyCFunction_CheckExact (C function):   Implementing functions and methods.
                                                             (line  279)
* PyCFunction_GET_FLAGS (C function):    Implementing functions and methods.
                                                             (line  306)
* PyCFunction_GET_FUNCTION (C function): Implementing functions and methods.
                                                             (line  322)
* PyCFunction_GET_SELF (C function):     Implementing functions and methods.
                                                             (line  342)
* PyCFunction_GetFlags (C function):     Implementing functions and methods.
                                                             (line  296)
* PyCFunction_GetFunction (C function):  Implementing functions and methods.
                                                             (line  311)
* PyCFunction_GetSelf (C function):      Implementing functions and methods.
                                                             (line  327)
* PyCFunction_New (C function):          Implementing functions and methods.
                                                             (line  290)
* PyCFunction_NewEx (C function):        Implementing functions and methods.
                                                             (line  284)
* PyCFunction_Type (C var):              Implementing functions and methods.
                                                             (line  269)
* PyCFunctionFast (C type):              Implementing functions and methods.
                                                             (line   29)
* PyCFunctionFastWithKeywords (C type):  Implementing functions and methods.
                                                             (line   38)
* PyCFunctionWithKeywords (C type):      Implementing functions and methods.
                                                             (line   20)
* PycInvalidationMode (classe in py_compile): py_compile — Compile Python source files.
                                                             (line   92)
* PyClassMethod_New (C function):        Built-in descriptors.
                                                             (line   23)
* PyClassMethod_Type (C var):            Built-in descriptors.
                                                             (line   11)
* PyClassMethodDescr_Type (C var):       Built-in descriptors.
                                                             (line   16)
* PyCMethod (C type):                    Implementing functions and methods.
                                                             (line   49)
* PyCMethod_Check (C function):          Implementing functions and methods.
                                                             (line  231)
* PyCMethod_CheckExact (C function):     Implementing functions and methods.
                                                             (line  236)
* PyCMethod_New (C function):            Implementing functions and methods.
                                                             (line  241)
* PyCMethod_Type (C var):                Implementing functions and methods.
                                                             (line  225)
* PyCode_Addr2Line (C function):         Code Objects.       (line   98)
* PyCode_Addr2Location (C function):     Code Objects.       (line  107)
* PyCode_AddWatcher (C function):        Code Objects.       (line  164)
* PyCode_Check (C function):             Code Objects.       (line   20)
* PyCode_ClearWatcher (C function):      Code Objects.       (line  173)
* PyCode_GetCellvars (C function):       Code Objects.       (line  143)
* PyCode_GetCode (C function):           Code Objects.       (line  119)
* PyCode_GetFreevars (C function):       Code Objects.       (line  154)
* PyCode_GetNumFree (C function):        Code Objects.       (line   25)
* PyCode_GetVarnames (C function):       Code Objects.       (line  133)
* PyCode_New (C function):               Code Objects.       (line   64)
* PyCode_NewEmpty (C function):          Code Objects.       (line   91)
* PyCode_NewWithPosOnlyArgs (C function): Code Objects.      (line   68)
* PyCode_Optimize (C function):          Code Objects.       (line  225)
* PyCode_Type (C var):                   Code Objects.       (line   15)
* PyCode_WatchCallback (C type):         Code Objects.       (line  189)
* PyCodec_BackslashReplaceErrors (C function): Registry API for Unicode encoding error handlers.
                                                             (line   58)
* PyCodec_Decode (C function):           Codec registry and support functions.
                                                             (line   38)
* PyCodec_Decoder (C function):          Codec lookup API.   (line   16)
* PyCodec_Encode (C function):           Codec registry and support functions.
                                                             (line   27)
* PyCodec_Encoder (C function):          Codec lookup API.   (line   11)
* PyCodec_IgnoreErrors (C function):     Registry API for Unicode encoding error handlers.
                                                             (line   40)
* PyCodec_IncrementalDecoder (C function): Codec lookup API. (line   27)
* PyCodec_IncrementalEncoder (C function): Codec lookup API. (line   21)
* PyCodec_KnownEncoding (C function):    Codec registry and support functions.
                                                             (line   22)
* PyCodec_LookupError (C function):      Registry API for Unicode encoding error handlers.
                                                             (line   27)
* PyCodec_NameReplaceErrors (C function): Registry API for Unicode encoding error handlers.
                                                             (line   64)
* PyCodec_Register (C function):         Codec registry and support functions.
                                                             (line    6)
* PyCodec_RegisterError (C function):    Registry API for Unicode encoding error handlers.
                                                             (line    6)
* PyCodec_ReplaceErrors (C function):    Registry API for Unicode encoding error handlers.
                                                             (line   46)
* PyCodec_StreamReader (C function):     Codec lookup API.   (line   33)
* PyCodec_StreamWriter (C function):     Codec lookup API.   (line   39)
* PyCodec_StrictErrors (C function):     Registry API for Unicode encoding error handlers.
                                                             (line   35)
* PyCodec_Unregister (C function):       Codec registry and support functions.
                                                             (line   14)
* PyCodec_XMLCharRefReplaceErrors (C function): Registry API for Unicode encoding error handlers.
                                                             (line   52)
* PyCodeEvent (C type):                  Code Objects.       (line  182)
* PyCodeObject (C type):                 Code Objects.       (line   10)
* PyCompactUnicodeObject (C type):       Unicode Type.       (line   29)
* PyCompile_OpcodeStackEffect (C function): Stack Effects.   (line   19)
* PyCompile_OpcodeStackEffectWithJump (C function): Stack Effects.
                                                             (line   28)
* PyCompileError:                        py_compile — Compile Python source files.
                                                             (line   19)
* PyCompilerFlags (C struct):            The Very High Level Layer.
                                                             (line  318)
* PyCompilerFlags.cf_feature_version (C member): The Very High Level Layer.
                                                             (line  334)
* PyCompilerFlags.cf_flags (C member):   The Very High Level Layer.
                                                             (line  330)
* PyComplex_AsCComplex (C function):     Complex Numbers as Python Objects.
                                                             (line   73)
* PyComplex_Check (C function):          Complex Numbers as Python Objects.
                                                             (line   16)
* PyComplex_CheckExact (C function):     Complex Numbers as Python Objects.
                                                             (line   22)
* PyComplex_FromCComplex (C function):   Complex Numbers as Python Objects.
                                                             (line   28)
* PyComplex_FromDoubles (C function):    Complex Numbers as Python Objects.
                                                             (line   34)
* PyComplex_ImagAsDouble (C function):   Complex Numbers as Python Objects.
                                                             (line   57)
* PyComplex_RealAsDouble (C function):   Complex Numbers as Python Objects.
                                                             (line   41)
* PyComplex_Type (C var):                Complex Numbers as Python Objects.
                                                             (line   11)
* PyComplexObject (C type):              Complex Numbers as Python Objects.
                                                             (line    6)
* PyConfig (C type):                     PyConfig.           (line    6)
* PyConfig_Clear (C function):           PyConfig.           (line   97)
* PyConfig_Get (C function):             Runtime Python configuration API.
                                                             (line   16)
* PyConfig_GetInt (C function):          Runtime Python configuration API.
                                                             (line   43)
* PyConfig_InitIsolatedConfig (C function): PyConfig.        (line   20)
* PyConfig_InitPythonConfig (C function): PyConfig.          (line   15)
* PyConfig_Names (C function):           Runtime Python configuration API.
                                                             (line   53)
* PyConfig_Read (C function):            PyConfig.           (line   66)
* PyConfig_Set (C function):             Runtime Python configuration API.
                                                             (line   67)
* PyConfig_SetArgv (C function):         PyConfig.           (line   41)
* PyConfig_SetBytesArgv (C function):    PyConfig.           (line   49)
* PyConfig_SetBytesString (C function):  PyConfig.           (line   32)
* PyConfig_SetString (C function):       PyConfig.           (line   25)
* PyConfig_SetWideStringList (C function): PyConfig.         (line   58)
* PyConfig._pystats (C member):          PyConfig.           (line 1022)
* PyConfig.argv (C member):              PyConfig.           (line  128)
* PyConfig.base_exec_prefix (C member):  PyConfig.           (line  173)
* PyConfig.base_executable (C member):   PyConfig.           (line  183)
* PyConfig.base_prefix (C member):       PyConfig.           (line  197)
* PyConfig.buffered_stdio (C member):    PyConfig.           (line  207)
* PyConfig.bytes_warning (C member):     PyConfig.           (line  220)
* PyConfig.check_hash_pycs_mode (C member): PyConfig.        (line  257)
* PyConfig.code_debug_ranges (C member): PyConfig.           (line  243)
* PyConfig.configure_c_stdio (C member): PyConfig.           (line  277)
* PyConfig.cpu_count (C member):         PyConfig.           (line  515)
* PyConfig.dev_mode (C member):          PyConfig.           (line  292)
* PyConfig.dump_refs (C member):         PyConfig.           (line  301)
* PyConfig.dump_refs_file (C member):    PyConfig.           (line  315)
* PyConfig.exec_prefix (C member):       PyConfig.           (line  326)
* PyConfig.executable (C member):        PyConfig.           (line  338)
* PyConfig.faulthandler (C member):      PyConfig.           (line  349)
* PyConfig.filesystem_encoding (C member): PyConfig.         (line  361)
* PyConfig.filesystem_errors (C member): PyConfig.           (line  394)
* PyConfig.hash_seed (C member):         PyConfig.           (line  426)
* PyConfig.home (C member):              PyConfig.           (line  441)
* PyConfig.import_time (C member):       PyConfig.           (line  452)
* PyConfig.inspect (C member):           PyConfig.           (line  466)
* PyConfig.install_signal_handlers (C member): PyConfig.     (line  481)
* PyConfig.int_max_str_digits (C member): PyConfig.          (line  495)
* PyConfig.interactive (C member):       PyConfig.           (line  487)
* PyConfig.isolated (C member):          PyConfig.           (line  529)
* PyConfig.legacy_windows_stdio (C member): PyConfig.        (line  554)
* PyConfig.malloc_stats (C member):      PyConfig.           (line  571)
* PyConfig.module_search_paths (C member): PyConfig.         (line  615)
* PyConfig.module_search_paths_set (C member): PyConfig.     (line  617)
* PyConfig.optimization_level (C member): PyConfig.          (line  631)
* PyConfig.orig_argv (C member):         PyConfig.           (line  647)
* PyConfig.parse_argv (C member):        PyConfig.           (line  665)
* PyConfig.parser_debug (C member):      PyConfig.           (line  686)
* PyConfig.pathconfig_warnings (C member): PyConfig.         (line  700)
* PyConfig.perf_profiling (C member):    PyConfig.           (line  894)
* PyConfig.platlibdir (C member):        PyConfig.           (line  584)
* PyConfig.prefix (C member):            PyConfig.           (line  712)
* PyConfig.program_name (C member):      PyConfig.           (line  723)
* PyConfig.pycache_prefix (C member):    PyConfig.           (line  744)
* PyConfig.pythonpath_env (C member):    PyConfig.           (line  604)
* PyConfig.quiet (C member):             PyConfig.           (line  757)
* PyConfig.run_command (C member):       PyConfig.           (line  766)
* PyConfig.run_filename (C member):      PyConfig.           (line  774)
* PyConfig.run_module (C member):        PyConfig.           (line  788)
* PyConfig.run_presite (C member):       PyConfig.           (line  796)
* PyConfig.safe_path (C member):         PyConfig.           (line  151)
* PyConfig.show_ref_count (C member):    PyConfig.           (line  810)
* PyConfig.site_import (C member):       PyConfig.           (line  822)
* PyConfig.skip_source_first_line (C member): PyConfig.      (line  841)
* PyConfig.stdio_encoding (C member):    PyConfig.           (line  853)
* PyConfig.stdio_errors (C member):      PyConfig.           (line  855)
* PyConfig.stdlib_dir (C member):        PyConfig.           (line  921)
* PyConfig.tracemalloc (C member):       PyConfig.           (line  883)
* PyConfig.use_environment (C member):   PyConfig.           (line  929)
* PyConfig.use_frozen_modules (C member): PyConfig.          (line  416)
* PyConfig.use_hash_seed (C member):     PyConfig.           (line  428)
* PyConfig.use_system_logger (C member): PyConfig.           (line  940)
* PyConfig.user_site_directory (C member): PyConfig.         (line  952)
* PyConfig.verbose (C member):           PyConfig.           (line  965)
* PyConfig.warn_default_encoding (C member): PyConfig.       (line  233)
* PyConfig.warnoptions (C member):       PyConfig.           (line  982)
* PyConfig.write_bytecode (C member):    PyConfig.           (line 1002)
* PyConfig.xoptions (C member):          PyConfig.           (line 1015)
* PyContext (C type):                    Context Variables Objects.
                                                             (line   26)
* PyContext_AddWatcher (C function):     Context Variables Objects.
                                                             (line   97)
* PyContext_CheckExact (C function):     Context Variables Objects.
                                                             (line   55)
* PyContext_ClearWatcher (C function):   Context Variables Objects.
                                                             (line  107)
* PyContext_Copy (C function):           Context Variables Objects.
                                                             (line   76)
* PyContext_CopyCurrent (C function):    Context Variables Objects.
                                                             (line   81)
* PyContext_Enter (C function):          Context Variables Objects.
                                                             (line   86)
* PyContext_Exit (C function):           Context Variables Objects.
                                                             (line   91)
* PyContext_New (C function):            Context Variables Objects.
                                                             (line   72)
* PyContext_Type (C var):                Context Variables Objects.
                                                             (line   41)
* PyContext_WatchCallback (C type):      Context Variables Objects.
                                                             (line  127)
* PyContextEvent (C type):               Context Variables Objects.
                                                             (line  116)
* PyContextToken (C type):               Context Variables Objects.
                                                             (line   36)
* PyContextToken_CheckExact (C function): Context Variables Objects.
                                                             (line   65)
* PyContextToken_Type (C var):           Context Variables Objects.
                                                             (line   49)
* PyContextVar (C type):                 Context Variables Objects.
                                                             (line   31)
* PyContextVar_CheckExact (C function):  Context Variables Objects.
                                                             (line   60)
* PyContextVar_Get (C function):         Context Variables Objects.
                                                             (line  157)
* PyContextVar_New (C function):         Context Variables Objects.
                                                             (line  149)
* PyContextVar_Reset (C function):       Context Variables Objects.
                                                             (line  181)
* PyContextVar_Set (C function):         Context Variables Objects.
                                                             (line  175)
* PyContextVar_Type (C var):             Context Variables Objects.
                                                             (line   45)
* PyCoro_CheckExact (C function):        Coroutine Objects<2>.
                                                             (line   19)
* PyCoro_New (C function):               Coroutine Objects<2>.
                                                             (line   24)
* PyCoro_Type (C var):                   Coroutine Objects<2>.
                                                             (line   15)
* PyCoroObject (C type):                 Coroutine Objects<2>.
                                                             (line   11)
* PyCurses_API (C var):                  Curses C API.       (line   29)
* PyCurses_API_pointers (C macro):       Curses C API.       (line   52)
* PyCurses_CAPSULE_NAME (C macro):       Internal data.      (line    9)
* PyCursesInitialised (C macro):         Curses C API.       (line   85)
* PyCursesInitialisedColor (C macro):    Curses C API.       (line   99)
* PyCursesSetupTermCalled (C macro):     Curses C API.       (line   71)
* PyCursesWindow_Check (C function):     Curses C API.       (line   62)
* PyCursesWindow_Type (C var):           Curses C API.       (line   57)
* PyDate_Check (C function):             DateTime Objects<2>.
                                                             (line  104)
* PyDate_CheckExact (C function):        DateTime Objects<2>.
                                                             (line  110)
* PyDate_FromDate (C function):          DateTime Objects<2>.
                                                             (line  161)
* PyDate_FromTimestamp (C function):     DateTime Objects<2>.
                                                             (line  336)
* PyDateTime_CAPI (C type):              DateTime Objects<2>.
                                                             (line   28)
* PyDateTime_CAPSULE_NAME (C macro):     Internal data<2>.   (line    9)
* PyDateTime_Check (C function):         DateTime Objects<2>.
                                                             (line  115)
* PyDateTime_CheckExact (C function):    DateTime Objects<2>.
                                                             (line  121)
* PyDateTime_Date (C type):              DateTime Objects<2>.
                                                             (line   43)
* PyDateTime_DATE_GET_FOLD (C function): DateTime Objects<2>.
                                                             (line  258)
* PyDateTime_DATE_GET_HOUR (C function): DateTime Objects<2>.
                                                             (line  241)
* PyDateTime_DATE_GET_MICROSECOND (C function): DateTime Objects<2>.
                                                             (line  253)
* PyDateTime_DATE_GET_MINUTE (C function): DateTime Objects<2>.
                                                             (line  245)
* PyDateTime_DATE_GET_SECOND (C function): DateTime Objects<2>.
                                                             (line  249)
* PyDateTime_DATE_GET_TZINFO (C function): DateTime Objects<2>.
                                                             (line  264)
* PyDateTime_DateTime (C type):          DateTime Objects<2>.
                                                             (line   48)
* PyDateTime_DateTimeType (C var):       DateTime Objects<2>.
                                                             (line   69)
* PyDateTime_DateType (C var):           DateTime Objects<2>.
                                                             (line   63)
* PyDateTime_Delta (C type):             DateTime Objects<2>.
                                                             (line   58)
* PyDateTime_DELTA_GET_DAYS (C function): DateTime Objects<2>.
                                                             (line  308)
* PyDateTime_DELTA_GET_MICROSECONDS (C function): DateTime Objects<2>.
                                                             (line  320)
* PyDateTime_DELTA_GET_SECONDS (C function): DateTime Objects<2>.
                                                             (line  314)
* PyDateTime_DeltaType (C var):          DateTime Objects<2>.
                                                             (line   81)
* PyDateTime_FromDateAndTime (C function): DateTime Objects<2>.
                                                             (line  166)
* PyDateTime_FromDateAndTimeAndFold (C function): DateTime Objects<2>.
                                                             (line  173)
* PyDateTime_FromTimestamp (C function): DateTime Objects<2>.
                                                             (line  329)
* PyDateTime_GET_DAY (C function):       DateTime Objects<2>.
                                                             (line  233)
* PyDateTime_GET_MONTH (C function):     DateTime Objects<2>.
                                                             (line  229)
* PyDateTime_GET_YEAR (C function):      DateTime Objects<2>.
                                                             (line  225)
* PyDateTime_IMPORT (C macro):           DateTime Objects<2>.
                                                             (line   14)
* PyDateTime_Time (C type):              DateTime Objects<2>.
                                                             (line   53)
* PyDateTime_TIME_GET_FOLD (C function): DateTime Objects<2>.
                                                             (line  291)
* PyDateTime_TIME_GET_HOUR (C function): DateTime Objects<2>.
                                                             (line  275)
* PyDateTime_TIME_GET_MICROSECOND (C function): DateTime Objects<2>.
                                                             (line  287)
* PyDateTime_TIME_GET_MINUTE (C function): DateTime Objects<2>.
                                                             (line  279)
* PyDateTime_TIME_GET_SECOND (C function): DateTime Objects<2>.
                                                             (line  283)
* PyDateTime_TIME_GET_TZINFO (C function): DateTime Objects<2>.
                                                             (line  297)
* PyDateTime_TimeType (C var):           DateTime Objects<2>.
                                                             (line   75)
* PyDateTime_TimeZone_UTC (C var):       DateTime Objects<2>.
                                                             (line   95)
* PyDateTime_TZInfoType (C var):         DateTime Objects<2>.
                                                             (line   87)
* PyDateTimeAPI (C var):                 DateTime Objects<2>.
                                                             (line   36)
* PyDelta_Check (C function):            DateTime Objects<2>.
                                                             (line  137)
* PyDelta_CheckExact (C function):       DateTime Objects<2>.
                                                             (line  143)
* PyDelta_FromDSU (C function):          DateTime Objects<2>.
                                                             (line  196)
* PyDescr_IsData (C function):           Descriptor Objects. (line   66)
* PyDescr_NewClassMethod (C function):   Descriptor Objects. (line   61)
* PyDescr_NewGetSet (C function):        Descriptor Objects. (line   13)
* PyDescr_NewMember (C function):        Descriptor Objects. (line   18)
* PyDescr_NewMethod (C function):        Descriptor Objects. (line   37)
* PyDescr_NewWrapper (C function):       Descriptor Objects. (line   49)
* PyDict_AddWatcher (C function):        Dictionary Objects. (line  347)
* PyDict_Check (C function):             Dictionary Objects. (line   16)
* PyDict_CheckExact (C function):        Dictionary Objects. (line   21)
* PyDict_Clear (C function):             Dictionary Objects. (line   49)
* PyDict_ClearWatcher (C function):      Dictionary Objects. (line  356)
* PyDict_Contains (C function):          Dictionary Objects. (line   53)
* PyDict_ContainsString (C function):    Dictionary Objects. (line   59)
* PyDict_Copy (C function):              Dictionary Objects. (line   67)
* PyDict_DelItem (C function):           Dictionary Objects. (line   86)
* PyDict_DelItemString (C function):     Dictionary Objects. (line   93)
* PyDict_GET_SIZE (C function):          Dictionary Objects. (line  243)
* PyDict_GetItem (C function):           Dictionary Objects. (line  115)
* PyDict_GetItemRef (C function):        Dictionary Objects. (line   98)
* PyDict_GetItemString (C function):     Dictionary Objects. (line  139)
* PyDict_GetItemStringRef (C function):  Dictionary Objects. (line  152)
* PyDict_GetItemWithError (C function):  Dictionary Objects. (line  131)
* PyDict_Items (C function):             Dictionary Objects. (line  222)
* PyDict_Keys (C function):              Dictionary Objects. (line  227)
* PyDict_Merge (C function):             Dictionary Objects. (line  314)
* PyDict_MergeFromSeq2 (C function):     Dictionary Objects. (line  332)
* PyDict_New (C function):               Dictionary Objects. (line   26)
* PyDict_Next (C function):              Dictionary Objects. (line  247)
* PyDict_Pop (C function):               Dictionary Objects. (line  194)
* PyDict_PopString (C function):         Dictionary Objects. (line  213)
* PyDict_SetDefault (C function):        Dictionary Objects. (line  161)
* PyDict_SetDefaultRef (C function):     Dictionary Objects. (line  173)
* PyDict_SetItem (C function):           Dictionary Objects. (line   72)
* PyDict_SetItemString (C function):     Dictionary Objects. (line   80)
* PyDict_Size (C function):              Dictionary Objects. (line  237)
* PyDict_Type (C var):                   Dictionary Objects. (line   11)
* PyDict_Unwatch (C function):           Dictionary Objects. (line  373)
* PyDict_Update (C function):            Dictionary Objects. (line  324)
* PyDict_Values (C function):            Dictionary Objects. (line  232)
* PyDict_Watch (C function):             Dictionary Objects. (line  364)
* PyDict_WatchCallback (C type):         Dictionary Objects. (line  392)
* PyDict_WatchEvent (C type):            Dictionary Objects. (line  383)
* PyDictItems_Check (C function):        Dictionary View Objects.
                                                             (line   38)
* PyDictItems_Type (C var):              Dictionary View Objects.
                                                             (line   33)
* PyDictIterItem_Type (C var):           Other Iterator Objects.
                                                             (line   42)
* PyDictIterKey_Type (C var):            Other Iterator Objects.
                                                             (line   30)
* PyDictIterValue_Type (C var):          Other Iterator Objects.
                                                             (line   36)
* PyDictKeys_Check (C function):         Dictionary View Objects.
                                                             (line   18)
* PyDictKeys_Type (C var):               Dictionary View Objects.
                                                             (line   13)
* PyDictObject (C type):                 Dictionary Objects. (line    6)
* PyDictProxy_New (C function):          Dictionary Objects. (line   31)
* PyDictProxy_Type (C var):              Dictionary Objects. (line   39)
* PyDictRevIterItem_Type (C var):        Other Iterator Objects.
                                                             (line   45)
* PyDictRevIterKey_Type (C var):         Other Iterator Objects.
                                                             (line   33)
* PyDictRevIterValue_Type (C var):       Other Iterator Objects.
                                                             (line   39)
* PyDictValues_Check (C function):       Dictionary View Objects.
                                                             (line   28)
* PyDictValues_Type (C var):             Dictionary View Objects.
                                                             (line   23)
* PyDictViewSet_Check (C function):      Dictionary View Objects.
                                                             (line    6)
* PyDLL (classe in ctypes):              Loading shared libraries.
                                                             (line   70)
* PyDoc_STR (C macro):                   Useful macros.      (line  208)
* PyDoc_STRVAR (C macro):                Useful macros.      (line  190)
* PyDoc_VAR (C macro):                   Useful macros.      (line  224)
* PyEllipsis_Type (C var):               Ellipsis Object.    (line    6)
* PyEnum_Type (C var):                   Builtin Iterator Types.
                                                             (line   13)
* PyErr_BadArgument (C function):        Raising exceptions. (line   47)
* PyErr_BadInternalCall (C function):    Raising exceptions. (line  232)
* PyErr_CheckSignals (C function):       Signal Handling<2>. (line    6)
* PyErr_Clear (C function):              Exceptions<23>.     (line   25)
* PyErr_Clear (C function) <1>:          Exceptions<23>.     (line  123)
* PyErr_Clear (C function) <2>:          Printing and clearing.
                                                             (line    6)
* PyErr_DisplayException (C function):   Printing and clearing.
                                                             (line   66)
* PyErr_ExceptionMatches (C function):   Exceptions<23>.     (line  123)
* PyErr_ExceptionMatches (C function) <1>: Querying the error indicator.
                                                             (line   23)
* PyErr_Fetch (C function):              Finalization and De-allocation.
                                                             (line   35)
* PyErr_Fetch (C function) <1>:          Querying the error indicator.
                                                             (line   75)
* PyErr_Format (C function):             Raising exceptions. (line   25)
* PyErr_FormatUnraisable (C function):   Printing and clearing.
                                                             (line   55)
* PyErr_FormatV (C function):            Raising exceptions. (line   34)
* PyErr_GetExcInfo (C function):         Querying the error indicator.
                                                             (line  179)
* PyErr_GetHandledException (C function): Querying the error indicator.
                                                             (line  150)
* PyErr_GetRaisedException (C function): Querying the error indicator.
                                                             (line   37)
* PyErr_GivenExceptionMatches (C function): Querying the error indicator.
                                                             (line   29)
* PyErr_NewException (C function):       Exception Classes.  (line    6)
* PyErr_NewExceptionWithDoc (C function): Exception Classes. (line   24)
* PyErr_NoMemory (C function):           Raising exceptions. (line   53)
* PyErr_NormalizeException (C function): Querying the error indicator.
                                                             (line  126)
* PyErr_Occurred (C function):           Exceptions<23>.     (line   12)
* PyErr_Occurred (C function) <1>:       Querying the error indicator.
                                                             (line    6)
* PyErr_Print (C function):              Printing and clearing.
                                                             (line   30)
* PyErr_PrintEx (C function):            Printing and clearing.
                                                             (line   10)
* PyErr_ProgramText (C function):        Raising exceptions. (line  249)
* PyErr_ProgramTextObject (C function):  Raising exceptions. (line  239)
* PyErr_RangedSyntaxLocationObject (C function): Raising exceptions.
                                                             (line  207)
* PyErr_ResourceWarning (C function):    Issuing warnings.   (line   79)
* PyErr_Restore (C function):            Finalization and De-allocation.
                                                             (line   35)
* PyErr_Restore (C function) <1>:        Querying the error indicator.
                                                             (line  103)
* PyErr_SetExcFromWindowsErr (C function): Raising exceptions.
                                                             (line  120)
* PyErr_SetExcFromWindowsErrWithFilename (C function): Raising exceptions.
                                                             (line  166)
* PyErr_SetExcFromWindowsErrWithFilenameObject (C function): Raising exceptions.
                                                             (line  142)
* PyErr_SetExcFromWindowsErrWithFilenameObjects (C function): Raising exceptions.
                                                             (line  154)
* PyErr_SetExcInfo (C function):         Querying the error indicator.
                                                             (line  198)
* PyErr_SetFromErrno (C function):       Raising exceptions. (line   59)
* PyErr_SetFromErrnoWithFilename (C function): Raising exceptions.
                                                             (line   97)
* PyErr_SetFromErrnoWithFilenameObject (C function): Raising exceptions.
                                                             (line   76)
* PyErr_SetFromErrnoWithFilenameObjects (C function): Raising exceptions.
                                                             (line   86)
* PyErr_SetFromWindowsErr (C function):  Raising exceptions. (line  104)
* PyErr_SetFromWindowsErrWithFilename (C function): Raising exceptions.
                                                             (line  129)
* PyErr_SetHandledException (C function): Querying the error indicator.
                                                             (line  166)
* PyErr_SetImportError (C function):     Raising exceptions. (line  176)
* PyErr_SetImportErrorSubclass (C function): Raising exceptions.
                                                             (line  187)
* PyErr_SetInterrupt (C function):       Signal Handling<2>. (line   33)
* PyErr_SetInterruptEx (C function):     Signal Handling<2>. (line   43)
* PyErr_SetNone (C function):            Raising exceptions. (line   43)
* PyErr_SetObject (C function):          Raising exceptions. (line   20)
* PyErr_SetRaisedException (C function): Querying the error indicator.
                                                             (line   65)
* PyErr_SetString (C function):          Exceptions<23>.     (line   25)
* PyErr_SetString (C function) <1>:      Raising exceptions. (line   10)
* PyErr_SyntaxLocation (C function):     Raising exceptions. (line  226)
* PyErr_SyntaxLocationEx (C function):   Raising exceptions. (line  217)
* PyErr_SyntaxLocationObject (C function): Raising exceptions.
                                                             (line  197)
* PyErr_WarnEx (C function):             Issuing warnings.   (line   19)
* PyErr_WarnExplicit (C function):       Issuing warnings.   (line   53)
* PyErr_WarnExplicitFormat (C function): Issuing warnings.   (line   69)
* PyErr_WarnExplicitObject (C function): Issuing warnings.   (line   41)
* PyErr_WarnFormat (C function):         Issuing warnings.   (line   61)
* PyErr_WriteUnraisable (C function):    Printing and clearing.
                                                             (line   33)
* PyEval_AcquireThread (C function):     Low-level API.      (line  279)
* PyEval_AcquireThread():                High-level API.     (line   35)
* PyEval_EvalCode (C function):          The Very High Level Layer.
                                                             (line  271)
* PyEval_EvalCodeEx (C function):        The Very High Level Layer.
                                                             (line  278)
* PyEval_EvalFrame (C function):         The Very High Level Layer.
                                                             (line  291)
* PyEval_EvalFrameEx (C function):       The Very High Level Layer.
                                                             (line  298)
* PyEval_GetBuiltins (C function):       Reflection.         (line    6)
* PyEval_GetFrame (C function):          Reflection.         (line   60)
* PyEval_GetFrameBuiltins (C function):  Reflection.         (line   67)
* PyEval_GetFrameGlobals (C function):   Reflection.         (line   89)
* PyEval_GetFrameLocals (C function):    Reflection.         (line   75)
* PyEval_GetFuncDesc (C function):       Reflection.         (line  103)
* PyEval_GetFuncName (C function):       Reflection.         (line   98)
* PyEval_GetGlobals (C function):        Reflection.         (line   50)
* PyEval_GetLocals (C function):         Reflection.         (line   17)
* PyEval_InitThreads (C function):       High-level API.     (line   34)
* PyEval_InitThreads():                  Initializing and finalizing the interpreter.
                                                             (line    7)
* PyEval_MergeCompilerFlags (C function): The Very High Level Layer.
                                                             (line  313)
* PyEval_ReleaseThread (C function):     Low-level API.      (line  304)
* PyEval_ReleaseThread():                High-level API.     (line   35)
* PyEval_RestoreThread (C function):     Detaching the thread state from extension code.
                                                             (line   31)
* PyEval_RestoreThread (C function) <1>: High-level API.     (line   58)
* PyEval_RestoreThread():                High-level API.     (line   35)
* PyEval_SaveThread (C function):        Detaching the thread state from extension code.
                                                             (line   31)
* PyEval_SaveThread (C function) <1>:    High-level API.     (line   53)
* PyEval_SaveThread():                   High-level API.     (line   35)
* PyEval_SetProfile (C function):        Profiling and Tracing.
                                                             (line  117)
* PyEval_SetProfileAllThreads (C function): Profiling and Tracing.
                                                             (line  132)
* PyEval_SetTrace (C function):          Profiling and Tracing.
                                                             (line  147)
* PyEval_SetTraceAllThreads (C function): Profiling and Tracing.
                                                             (line  162)
* PyExc_ArithmeticError (C var):         Exception types.    (line   23)
* PyExc_AssertionError (C var):          Exception types.    (line   27)
* PyExc_AttributeError (C var):          Exception types.    (line   31)
* PyExc_BaseException (C var):           Exception types.    (line   10)
* PyExc_BaseExceptionGroup (C var):      Exception types.    (line   14)
* PyExc_BlockingIOError (C var):         Exception types.    (line   35)
* PyExc_BrokenPipeError (C var):         Exception types.    (line   40)
* PyExc_BufferError (C var):             Exception types.    (line   45)
* PyExc_BytesWarning (C var):            Warning types.      (line   13)
* PyExc_ChildProcessError (C var):       Exception types.    (line   49)
* PyExc_ConnectionAbortedError (C var):  Exception types.    (line   54)
* PyExc_ConnectionError (C var):         Exception types.    (line   59)
* PyExc_ConnectionRefusedError (C var):  Exception types.    (line   64)
* PyExc_ConnectionResetError (C var):    Exception types.    (line   69)
* PyExc_DeprecationWarning (C var):      Warning types.      (line   17)
* PyExc_EncodingWarning (C var):         Warning types.      (line   21)
* PyExc_EnvironmentError (C var):        OSError aliases.    (line   15)
* PyExc_EOFError (C var):                Exception types.    (line   74)
* PyExc_Exception (C var):               Exception types.    (line   19)
* PyExc_FileExistsError (C var):         Exception types.    (line   78)
* PyExc_FileNotFoundError (C var):       Exception types.    (line   83)
* PyExc_FloatingPointError (C var):      Exception types.    (line   88)
* PyExc_FutureWarning (C var):           Warning types.      (line   26)
* PyExc_GeneratorExit (C var):           Exception types.    (line   92)
* PyExc_ImportError (C var):             Exception types.    (line   96)
* PyExc_ImportWarning (C var):           Warning types.      (line   30)
* PyExc_IndentationError (C var):        Exception types.    (line  100)
* PyExc_IndexError (C var):              Exception types.    (line  104)
* PyExc_InterruptedError (C var):        Exception types.    (line  108)
* PyExc_IOError (C var):                 OSError aliases.    (line   21)
* PyExc_IsADirectoryError (C var):       Exception types.    (line  113)
* PyExc_KeyboardInterrupt (C var):       Exception types.    (line  122)
* PyExc_KeyError (C var):                Exception types.    (line  118)
* PyExc_LookupError (C var):             Exception types.    (line  126)
* PyExc_MemoryError (C var):             Exception types.    (line  130)
* PyExc_ModuleNotFoundError (C var):     Exception types.    (line  134)
* PyExc_NameError (C var):               Exception types.    (line  139)
* PyExc_NotADirectoryError (C var):      Exception types.    (line  143)
* PyExc_NotImplementedError (C var):     Exception types.    (line  148)
* PyExc_OSError (C var):                 Exception types.    (line  152)
* PyExc_OverflowError (C var):           Exception types.    (line  155)
* PyExc_PendingDeprecationWarning (C var): Warning types.    (line   34)
* PyExc_PermissionError (C var):         Exception types.    (line  159)
* PyExc_ProcessLookupError (C var):      Exception types.    (line  164)
* PyExc_PythonFinalizationError (C var): Exception types.    (line  169)
* PyExc_RecursionError (C var):          Exception types.    (line  172)
* PyExc_ReferenceError (C var):          Exception types.    (line  177)
* PyExc_ResourceWarning (C var):         Warning types.      (line   38)
* PyExc_RuntimeError (C var):            Exception types.    (line  181)
* PyExc_RuntimeWarning (C var):          Warning types.      (line   43)
* PyExc_StopAsyncIteration (C var):      Exception types.    (line  185)
* PyExc_StopIteration (C var):           Exception types.    (line  190)
* PyExc_SyntaxError (C var):             Exception types.    (line  194)
* PyExc_SyntaxWarning (C var):           Warning types.      (line   47)
* PyExc_SystemError (C var):             Exception types.    (line  198)
* PyExc_SystemExit (C var):              Exception types.    (line  202)
* PyExc_TabError (C var):                Exception types.    (line  206)
* PyExc_TimeoutError (C var):            Exception types.    (line  210)
* PyExc_TypeError (C var):               Exception types.    (line  215)
* PyExc_UnboundLocalError (C var):       Exception types.    (line  219)
* PyExc_UnicodeDecodeError (C var):      Exception types.    (line  223)
* PyExc_UnicodeEncodeError (C var):      Exception types.    (line  227)
* PyExc_UnicodeError (C var):            Exception types.    (line  231)
* PyExc_UnicodeTranslateError (C var):   Exception types.    (line  235)
* PyExc_UnicodeWarning (C var):          Warning types.      (line   51)
* PyExc_UserWarning (C var):             Warning types.      (line   55)
* PyExc_ValueError (C var):              Exception types.    (line  239)
* PyExc_Warning (C var):                 Warning types.      (line   10)
* PyExc_WindowsError (C var):            OSError aliases.    (line   27)
* PyExc_ZeroDivisionError (C var):       Exception types.    (line  243)
* PyException_GetArgs (C function):      Exception Objects.  (line   62)
* PyException_GetCause (C function):     Exception Objects.  (line   44)
* PyException_GetContext (C function):   Exception Objects.  (line   28)
* PyException_GetTraceback (C function): Exception Objects.  (line   15)
* PyException_SetArgs (C function):      Exception Objects.  (line   67)
* PyException_SetCause (C function):     Exception Objects.  (line   52)
* PyException_SetContext (C function):   Exception Objects.  (line   37)
* PyException_SetTraceback (C function): Exception Objects.  (line   23)
* PyExceptionClass_Check (C function):   Exception Classes.  (line   34)
* PyExceptionClass_Name (C function):    Exception Classes.  (line   39)
* PyExceptionInstance_Check (C function): Exception Objects. (line    6)
* PyExceptionInstance_Class (C macro):   Exception Objects.  (line   11)
* PyFile_FromFd (C function):            File Objects.       (line   15)
* PyFile_GetLine (C function):           File Objects.       (line   41)
* PyFile_NewStdPrinter (C function):     Deprecated API<4>.  (line   10)
* PyFile_OpenCode (C function):          File Objects.       (line  108)
* PyFile_OpenCodeObject (C function):    File Objects.       (line   92)
* PyFile_SetOpenCodeHook (C function):   File Objects.       (line   57)
* PyFile_WriteObject (C function):       File Objects.       (line  115)
* PyFile_WriteString (C function):       File Objects.       (line  125)
* PyFilter_Type (C var):                 Builtin Iterator Types.
                                                             (line   17)
* PyFloat_AS_DOUBLE (C function):        Floating-Point Objects.
                                                             (line   51)
* PyFloat_AsDouble (C function):         Floating-Point Objects.
                                                             (line   38)
* PyFloat_Check (C function):            Floating-Point Objects.
                                                             (line   16)
* PyFloat_CheckExact (C function):       Floating-Point Objects.
                                                             (line   22)
* PyFloat_FromDouble (C function):       Floating-Point Objects.
                                                             (line   33)
* PyFloat_FromString (C function):       Floating-Point Objects.
                                                             (line   28)
* PyFloat_GetInfo (C function):          Floating-Point Objects.
                                                             (line   56)
* PyFloat_GetMax (C function):           Floating-Point Objects.
                                                             (line   62)
* PyFloat_GetMin (C function):           Floating-Point Objects.
                                                             (line   66)
* PyFloat_Pack2 (C function):            Pack functions.     (line   22)
* PyFloat_Pack4 (C function):            Pack functions.     (line   26)
* PyFloat_Pack8 (C function):            Pack functions.     (line   30)
* PyFloat_Type (C var):                  Floating-Point Objects.
                                                             (line   11)
* PyFloat_Unpack2 (C function):          Unpack functions.   (line   20)
* PyFloat_Unpack4 (C function):          Unpack functions.   (line   24)
* PyFloat_Unpack8 (C function):          Unpack functions.   (line   28)
* PyFloatObject (C type):                Floating-Point Objects.
                                                             (line    6)
* PyFrame_Check (C function):            Frame Objects.      (line   37)
* PyFrame_FastToLocals (C function):     Legacy Local Variable APIs.
                                                             (line   21)
* PyFrame_FastToLocalsWithError (C function): Legacy Local Variable APIs.
                                                             (line   32)
* PyFrame_GetBack (C function):          Frame Objects.      (line   44)
* PyFrame_GetBuiltins (C function):      Frame Objects.      (line   54)
* PyFrame_GetCode (C function):          Frame Objects.      (line   63)
* PyFrame_GetGenerator (C function):     Frame Objects.      (line   74)
* PyFrame_GetGlobals (C function):       Frame Objects.      (line   85)
* PyFrame_GetLasti (C function):         Frame Objects.      (line   94)
* PyFrame_GetLineNumber (C function):    Frame Objects.      (line  144)
* PyFrame_GetLocals (C function):        Frame Objects.      (line  127)
* PyFrame_GetVar (C function):           Frame Objects.      (line  102)
* PyFrame_GetVarString (C function):     Frame Objects.      (line  119)
* PyFrame_LocalsToFast (C function):     Legacy Local Variable APIs.
                                                             (line    9)
* PyFrame_New (C function):              Frame Objects.      (line   29)
* PyFrame_Type (C var):                  Frame Objects.      (line   21)
* PyFrameLocalsProxy_Check (C function): Frame Locals Proxies.
                                                             (line   20)
* PyFrameLocalsProxy_Type (C var):       Frame Locals Proxies.
                                                             (line   16)
* PyFrameObject (C type):                Frame Objects.      (line    6)
* PyFrozenSet_Check (C function):        Set Objects.        (line   49)
* PyFrozenSet_CheckExact (C function):   Set Objects.        (line   73)
* PyFrozenSet_New (C function):          Set Objects.        (line   87)
* PyFrozenSet_Type (C var):              Set Objects.        (line   35)
* PyFunction_AddWatcher (C function):    Function Objects<3>.
                                                             (line  150)
* PyFunction_Check (C function):         Function Objects<3>.
                                                             (line   18)
* PyFunction_ClearWatcher (C function):  Function Objects<3>.
                                                             (line  160)
* PyFunction_GET_ANNOTATIONS (C function): Function Objects<3>.
                                                             (line  132)
* PyFunction_GET_CLOSURE (C function):   Function Objects<3>.
                                                             (line  132)
* PyFunction_GET_CODE (C function):      Function Objects<3>.
                                                             (line  132)
* PyFunction_GET_DEFAULTS (C function):  Function Objects<3>.
                                                             (line  132)
* PyFunction_GET_GLOBALS (C function):   Function Objects<3>.
                                                             (line  132)
* PyFunction_GET_KW_DEFAULTS (C function): Function Objects<3>.
                                                             (line  132)
* PyFunction_GET_MODULE (C function):    Function Objects<3>.
                                                             (line  132)
* PyFunction_GetAnnotations (C function): Function Objects<3>.
                                                             (line  118)
* PyFunction_GetClosure (C function):    Function Objects<3>.
                                                             (line  104)
* PyFunction_GetCode (C function):       Function Objects<3>.
                                                             (line   46)
* PyFunction_GetDefaults (C function):   Function Objects<3>.
                                                             (line   64)
* PyFunction_GetGlobals (C function):    Function Objects<3>.
                                                             (line   50)
* PyFunction_GetKwDefaults (C function): Function Objects<3>.
                                                             (line   88)
* PyFunction_GetModule (C function):     Function Objects<3>.
                                                             (line   55)
* PyFunction_New (C function):           Function Objects<3>.
                                                             (line   24)
* PyFunction_NewWithQualName (C function): Function Objects<3>.
                                                             (line   36)
* PyFunction_SetAnnotations (C function): Function Objects<3>.
                                                             (line  124)
* PyFunction_SetClosure (C function):    Function Objects<3>.
                                                             (line  110)
* PyFunction_SetDefaults (C function):   Function Objects<3>.
                                                             (line   70)
* PyFunction_SetKwDefaults (C function): Function Objects<3>.
                                                             (line   94)
* PyFunction_SetVectorcall (C function): Function Objects<3>.
                                                             (line   78)
* PyFunction_Type (C var):               Function Objects<3>.
                                                             (line   12)
* PyFunction_WatchCallback (C type):     Function Objects<3>.
                                                             (line  185)
* PyFunction_WatchEvent (C type):        Function Objects<3>.
                                                             (line  169)
* PyFunctionObject (C type):             Function Objects<3>.
                                                             (line    8)
* PYFUNCTYPE() (nel modulo ctypes):      Function prototypes.
                                                             (line   35)
* PyGC_Collect (C function):             Controlling the Garbage Collector State.
                                                             (line    9)
* PyGC_Disable (C function):             Controlling the Garbage Collector State.
                                                             (line   27)
* PyGC_Enable (C function):              Controlling the Garbage Collector State.
                                                             (line   20)
* PyGC_IsEnabled (C function):           Controlling the Garbage Collector State.
                                                             (line   34)
* PyGen_Check (C function):              Generator Objects.  (line   19)
* PyGen_CheckExact (C function):         Generator Objects.  (line   24)
* PyGen_GetCode (C function):            Generator Objects.  (line   43)
* PyGen_New (C function):                Generator Objects.  (line   29)
* PyGen_NewWithQualName (C function):    Generator Objects.  (line   35)
* PyGen_Type (C var):                    Generator Objects.  (line   15)
* PyGenObject (C type):                  Generator Objects.  (line   11)
* PyGetSetDef (C type):                  Defining Getters and Setters.
                                                             (line    6)
* PyGetSetDef.closure (C member):        Defining Getters and Setters.
                                                             (line   28)
* PyGetSetDef.doc (C member):            Defining Getters and Setters.
                                                             (line   24)
* PyGetSetDef.get (C member):            Defining Getters and Setters.
                                                             (line   15)
* PyGetSetDef.name (C member):           Defining Getters and Setters.
                                                             (line   11)
* PyGetSetDef.set (C member):            Defining Getters and Setters.
                                                             (line   19)
* PyGetSetDescr_Type (C var):            Descriptor Objects. (line   30)
* PyGILState_Check (C function):         High-level API.     (line  190)
* PyGILState_Ensure (C function):        High-level API.     (line  127)
* PyGILState_GetThisThreadState (C function): High-level API.
                                                             (line  171)
* PyGILState_Release (C function):       High-level API.     (line  161)
* PyGILState_STATE (C type):             High-level API.     (line  112)
* PyGILState_STATE.PyGILState_LOCKED (C enumerator): High-level API.
                                                             (line  117)
* PyGILState_STATE.PyGILState_UNLOCKED (C enumerator): High-level API.
                                                             (line  122)
* PyHASH_BITS (C macro):                 PyHash API.         (line   73)
* PyHash_FuncDef (C type):               PyHash API.         (line  101)
* PyHash_FuncDef.hash (C member):        PyHash API.         (line  105)
* PyHash_FuncDef.hash_bits (C member):   PyHash API.         (line  117)
* PyHash_FuncDef.name (C member):        PyHash API.         (line  110)
* PyHash_FuncDef.seed_bits (C member):   PyHash API.         (line  124)
* PyHash_GetFuncDef (C function):        PyHash API.         (line  133)
* PyHASH_IMAG (C macro):                 PyHash API.         (line   93)
* PyHASH_INF (C macro):                  PyHash API.         (line   85)
* PyHASH_MODULUS (C macro):              PyHash API.         (line   64)
* PyHASH_MULTIPLIER (C macro):           PyHash API.         (line   79)
* PyImport_AddModule (C function):       Importing Modules<2>.
                                                             (line  124)
* PyImport_AddModuleObject (C function): Importing Modules<2>.
                                                             (line  115)
* PyImport_AddModuleRef (C function):    Importing Modules<2>.
                                                             (line   92)
* PyImport_AppendInittab (C function):   Importing Modules<2>.
                                                             (line  302)
* PyImport_ExecCodeModule (C function):  Importing Modules<2>.
                                                             (line  130)
* PyImport_ExecCodeModuleEx (C function): Importing Modules<2>.
                                                             (line  170)
* PyImport_ExecCodeModuleObject (C function): Importing Modules<2>.
                                                             (line  179)
* PyImport_ExecCodeModuleWithPathnames (C function): Importing Modules<2>.
                                                             (line  194)
* PyImport_ExtendInittab (C function):   Importing Modules<2>.
                                                             (line  329)
* PyImport_FrozenModules (C var):        Importing Modules<2>.
                                                             (line  293)
* PyImport_GetImporter (C function):     Importing Modules<2>.
                                                             (line  243)
* PyImport_GetMagicNumber (C function):  Importing Modules<2>.
                                                             (line  211)
* PyImport_GetMagicTag (C function):     Importing Modules<2>.
                                                             (line  219)
* PyImport_GetModule (C function):       Importing Modules<2>.
                                                             (line  233)
* PyImport_GetModuleDict (C function):   Importing Modules<2>.
                                                             (line  227)
* PyImport_Import (C function):          Importing Modules<2>.
                                                             (line   74)
* PyImport_ImportFrozenModule (C function): Importing Modules<2>.
                                                             (line  270)
* PyImport_ImportFrozenModuleObject (C function): Importing Modules<2>.
                                                             (line  256)
* PyImport_ImportModule (C function):    Importing Modules<2>.
                                                             (line    6)
* PyImport_ImportModuleAttr (C function): Importing Modules<2>.
                                                             (line  350)
* PyImport_ImportModuleAttrString (C function): Importing Modules<2>.
                                                             (line  364)
* PyImport_ImportModuleEx (C function):  Importing Modules<2>.
                                                             (line   29)
* PyImport_ImportModuleLevel (C function): Importing Modules<2>.
                                                             (line   63)
* PyImport_ImportModuleLevelObject (C function): Importing Modules<2>.
                                                             (line   46)
* PyImport_ImportModuleNoBlock (C function): Importing Modules<2>.
                                                             (line   14)
* PyImport_Inittab (C var):              Importing Modules<2>.
                                                             (line  344)
* PyImport_ReloadModule (C function):    Importing Modules<2>.
                                                             (line   85)
* PyIndex_Check (C function):            Number Protocol.    (line  313)
* PyInit_modulename (C function):        Initialization function.
                                                             (line    9)
* PyInitConfig (C struct):               Create Config.      (line    6)
* PyInitConfig_AddModule (C function):   Module.             (line    6)
* PyInitConfig_Create (C function):      Create Config.      (line   10)
* PyInitConfig_Free (C function):        Create Config.      (line   19)
* PyInitConfig_FreeStrList (C function): Get Options.        (line   55)
* PyInitConfig_GetError (C function):    Error Handling.     (line    6)
* PyInitConfig_GetExitCode (C function): Error Handling.     (line   24)
* PyInitConfig_GetInt (C function):      Get Options.        (line   17)
* PyInitConfig_GetStr (C function):      Get Options.        (line   26)
* PyInitConfig_GetStrList (C function):  Get Options.        (line   42)
* PyInitConfig_HasOption (C function):   Get Options.        (line   10)
* PyInitConfig_SetInt (C function):      Set Options.        (line   15)
* PyInitConfig_SetStr (C function):      Set Options.        (line   24)
* PyInitConfig_SetStrList (C function):  Set Options.        (line   34)
* PyInstanceMethod_Check (C function):   Instance Method Objects.
                                                             (line   15)
* PyInstanceMethod_Function (C function): Instance Method Objects.
                                                             (line   28)
* PyInstanceMethod_GET_FUNCTION (C function): Instance Method Objects.
                                                             (line   33)
* PyInstanceMethod_New (C function):     Instance Method Objects.
                                                             (line   21)
* PyInstanceMethod_Type (C var):         Instance Method Objects.
                                                             (line   10)
* PyInterpreterConfig (C type):          Sub-interpreter support.
                                                             (line   24)
* PyInterpreterConfig_DEFAULT_GIL (C macro): Sub-interpreter support.
                                                             (line   93)
* PyInterpreterConfig_OWN_GIL (C macro): Sub-interpreter support.
                                                             (line  102)
* PyInterpreterConfig_SHARED_GIL (C macro): Sub-interpreter support.
                                                             (line   98)
* PyInterpreterConfig.allow_daemon_threads (C member): Sub-interpreter support.
                                                             (line   69)
* PyInterpreterConfig.allow_exec (C member): Sub-interpreter support.
                                                             (line   54)
* PyInterpreterConfig.allow_fork (C member): Sub-interpreter support.
                                                             (line   45)
* PyInterpreterConfig.allow_threads (C member): Sub-interpreter support.
                                                             (line   64)
* PyInterpreterConfig.check_multi_interp_extensions (C member): Sub-interpreter support.
                                                             (line   76)
* PyInterpreterConfig.gil (C member):    Sub-interpreter support.
                                                             (line   88)
* PyInterpreterConfig.use_main_obmalloc (C member): Sub-interpreter support.
                                                             (line   35)
* PyInterpreterState (C type):           High-level API.     (line    9)
* PyInterpreterState_Clear (C function): Low-level API.      (line   22)
* PyInterpreterState_Delete (C function): Low-level API.     (line   31)
* PyInterpreterState_Get (C function):   Low-level API.      (line  182)
* PyInterpreterState_GetDict (C function): Low-level API.    (line  202)
* PyInterpreterState_GetID (C function): Low-level API.      (line  192)
* PyInterpreterState_Head (C function):  Advanced Debugger Support.
                                                             (line    9)
* PyInterpreterState_Main (C function):  Advanced Debugger Support.
                                                             (line   15)
* PyInterpreterState_New (C function):   Low-level API.      (line   12)
* PyInterpreterState_Next (C function):  Advanced Debugger Support.
                                                             (line   20)
* PyInterpreterState_ThreadHead (C function): Advanced Debugger Support.
                                                             (line   26)
* PyIter_Check (C function):             Iterator Protocol.  (line    8)
* PyIter_Next (C function):              Iterator Protocol.  (line   30)
* PyIter_NextItem (C function):          Iterator Protocol.  (line   21)
* PyIter_Send (C function):              Iterator Protocol.  (line   49)
* PYLAUNCHER_ALLOW_INSTALL:              Windows<16>.        (line   24)
* PYLAUNCHER_ALLOW_INSTALL <1>:          Windows<30>.        (line   15)
* PyList_Append (C function):            List Objects.       (line  105)
* PyList_AsTuple (C function):           List Objects.       (line  160)
* PyList_Check (C function):             List Objects.       (line   16)
* PyList_CheckExact (C function):        List Objects.       (line   21)
* PyList_Clear (C function):             List Objects.       (line  139)
* PyList_Extend (C function):            List Objects.       (line  128)
* PyList_GET_ITEM (C function):          List Objects.       (line   68)
* PyList_GET_SIZE (C function):          List Objects.       (line   46)
* PyList_GetItem (C function):           Reference Count Details.
                                                             (line  117)
* PyList_GetItem (C function) <1>:       List Objects.       (line   61)
* PyList_GetItemRef (C function):        List Objects.       (line   50)
* PyList_GetSlice (C function):          List Objects.       (line  111)
* PyList_Insert (C function):            List Objects.       (line   98)
* PyList_New (C function):               List Objects.       (line   26)
* PyList_Reverse (C function):           List Objects.       (line  155)
* PyList_SET_ITEM (C function):          List Objects.       (line   83)
* PyList_SetItem (C function):           Reference Count Details.
                                                             (line   26)
* PyList_SetItem (C function) <1>:       List Objects.       (line   73)
* PyList_SetSlice (C function):          List Objects.       (line  119)
* PyList_Size (C function):              List Objects.       (line   40)
* PyList_Sort (C function):              List Objects.       (line  150)
* PyList_Type (C var):                   List Objects.       (line   11)
* PyListIter_Type (C var):               Other Iterator Objects.
                                                             (line   12)
* PyListObject (C type):                 List Objects.       (line    6)
* PyListRevIter_Type (C var):            Other Iterator Objects.
                                                             (line   15)
* PyLockStatus (C type):                 Legacy Locking APIs.
                                                             (line   16)
* PyLong_AS_LONG (C function):           Integer Objects.    (line  186)
* PyLong_AsDouble (C function):          Integer Objects.    (line  397)
* PyLong_AsInt (C function):             Integer Objects.    (line  195)
* PyLong_AsInt32 (C function):           Integer Objects.    (line  356)
* PyLong_AsInt64 (C function):           Integer Objects.    (line  356)
* PyLong_AsLong (C function):            Integer Objects.    (line  166)
* PyLong_AsLongAndOverflow (C function): Integer Objects.    (line  202)
* PyLong_AsLongLong (C function):        Integer Objects.    (line  223)
* PyLong_AsLongLongAndOverflow (C function): Integer Objects.
                                                             (line  243)
* PyLong_AsNativeBytes (C function):     Integer Objects.    (line  418)
* PyLong_AsPid (C macro):                Integer Objects.    (line  578)
* PyLong_AsSize_t (C function):          Integer Objects.    (line  291)
* PyLong_AsSsize_t (C function):         Integer Objects.    (line  266)
* PyLong_AsUInt32 (C function):          Integer Objects.    (line  375)
* PyLong_AsUInt64 (C function):          Integer Objects.    (line  375)
* PyLong_AsUnsignedLong (C function):    Integer Objects.    (line  279)
* PyLong_AsUnsignedLongLong (C function): Integer Objects.   (line  303)
* PyLong_AsUnsignedLongLongMask (C function): Integer Objects.
                                                             (line  337)
* PyLong_AsUnsignedLongMask (C function): Integer Objects.   (line  319)
* PyLong_AsVoidPtr (C function):         Integer Objects.    (line  408)
* PyLong_BASE (C macro):                 Deprecated API.     (line   20)
* PyLong_Check (C function):             Integer Objects.    (line   23)
* PyLong_CheckExact (C function):        Integer Objects.    (line   28)
* PyLong_Export (C function):            Export API.         (line   89)
* PyLong_FreeExport (C function):        Export API.         (line  107)
* PyLong_FromDouble (C function):        Integer Objects.    (line   86)
* PyLong_FromInt32 (C function):         Integer Objects.    (line   64)
* PyLong_FromInt64 (C function):         Integer Objects.    (line   64)
* PyLong_FromLong (C function):          Integer Objects.    (line   33)
* PyLong_FromLongLong (C function):      Integer Objects.    (line   59)
* PyLong_FromNativeBytes (C function):   Integer Objects.    (line  128)
* PyLong_FromPid (C macro):              Integer Objects.    (line  156)
* PyLong_FromSize_t (C function):        Integer Objects.    (line   54)
* PyLong_FromSsize_t (C function):       Integer Objects.    (line   49)
* PyLong_FromString (C function):        Integer Objects.    (line   91)
* PyLong_FromUInt32 (C function):        Integer Objects.    (line   78)
* PyLong_FromUInt64 (C function):        Integer Objects.    (line   78)
* PyLong_FromUnicodeObject (C function): Integer Objects.    (line  115)
* PyLong_FromUnsignedLong (C function):  Integer Objects.    (line   43)
* PyLong_FromUnsignedLongLong (C function): Integer Objects. (line   72)
* PyLong_FromUnsignedNativeBytes (C function): Integer Objects.
                                                             (line  143)
* PyLong_FromVoidPtr (C function):       Integer Objects.    (line  122)
* PyLong_GetInfo (C function):           Integer Objects.    (line  630)
* PyLong_GetNativeLayout (C function):   Export API.         (line   46)
* PyLong_GetSign (C function):           Integer Objects.    (line  588)
* PyLong_IsNegative (C function):        Integer Objects.    (line  610)
* PyLong_IsPositive (C function):        Integer Objects.    (line  600)
* PyLong_IsZero (C function):            Integer Objects.    (line  620)
* PyLong_MASK (C macro):                 Deprecated API.     (line   24)
* PyLong_SHIFT (C macro):                Deprecated API.     (line   15)
* PyLong_Type (C var):                   Integer Objects.    (line   18)
* PyLongExport (C struct):               Export API.         (line   58)
* PyLongExport.digits (C member):        Export API.         (line   85)
* PyLongExport.ndigits (C member):       Export API.         (line   80)
* PyLongExport.negative (C member):      Export API.         (line   75)
* PyLongExport.value (C member):         Export API.         (line   70)
* PyLongLayout (C struct):               Export API.         (line    8)
* PyLongLayout.bits_per_digit (C member): Export API.        (line   20)
* PyLongLayout.digit_endianness (C member): Export API.      (line   38)
* PyLongLayout.digit_size (C member):    Export API.         (line   25)
* PyLongLayout.digits_order (C member):  Export API.         (line   30)
* PyLongObject (C type):                 Integer Objects.    (line   13)
* PyLongRangeIter_Type (C var):          Other Iterator Objects.
                                                             (line   27)
* PyLongWriter (C struct):               PyLongWriter API.   (line   10)
* PyLongWriter_Create (C function):      PyLongWriter API.   (line   17)
* PyLongWriter_Discard (C function):     PyLongWriter API.   (line   59)
* PyLongWriter_Finish (C function):      PyLongWriter API.   (line   45)
* PyMap_Type (C var):                    Builtin Iterator Types.
                                                             (line   21)
* PyMapping_Check (C function):          Mapping Protocol.   (line    9)
* PyMapping_DelItem (C function):        Mapping Protocol.   (line   60)
* PyMapping_DelItemString (C function):  Mapping Protocol.   (line   64)
* PyMapping_GetItemString (C function):  Mapping Protocol.   (line   24)
* PyMapping_GetOptionalItem (C function): Mapping Protocol.  (line   31)
* PyMapping_GetOptionalItemString (C function): Mapping Protocol.
                                                             (line   45)
* PyMapping_HasKey (C function):         Mapping Protocol.   (line   89)
* PyMapping_HasKeyString (C function):   Mapping Protocol.   (line  100)
* PyMapping_HasKeyStringWithError (C function): Mapping Protocol.
                                                             (line   80)
* PyMapping_HasKeyWithError (C function): Mapping Protocol.  (line   71)
* PyMapping_Items (C function):          Mapping Protocol.   (line  129)
* PyMapping_Keys (C function):           Mapping Protocol.   (line  113)
* PyMapping_Length (C function):         Mapping Protocol.   (line   17)
* PyMapping_SetItemString (C function):  Mapping Protocol.   (line   54)
* PyMapping_Size (C function):           Mapping Protocol.   (line   17)
* PyMapping_Values (C function):         Mapping Protocol.   (line  121)
* PyMappingMethods (C type):             Mapping Object Structures.
                                                             (line    6)
* PyMappingMethods.mp_ass_subscript (C member): Mapping Object Structures.
                                                             (line   33)
* PyMappingMethods.mp_length (C member): Mapping Object Structures.
                                                             (line   11)
* PyMappingMethods.mp_subscript (C member): Mapping Object Structures.
                                                             (line   21)
* PyMarshal_ReadLastObjectFromFile (C function): Data marshalling support.
                                                             (line   75)
* PyMarshal_ReadLongFromFile (C function): Data marshalling support.
                                                             (line   48)
* PyMarshal_ReadObjectFromFile (C function): Data marshalling support.
                                                             (line   66)
* PyMarshal_ReadObjectFromString (C function): Data marshalling support.
                                                             (line   91)
* PyMarshal_ReadShortFromFile (C function): Data marshalling support.
                                                             (line   57)
* PyMarshal_WriteLongToFile (C function): Data marshalling support.
                                                             (line   21)
* PyMarshal_WriteObjectToFile (C function): Data marshalling support.
                                                             (line   31)
* PyMarshal_WriteObjectToString (C function): Data marshalling support.
                                                             (line   40)
* PyMem_Calloc (C function):             Memory Interface.   (line   28)
* PyMem_Del (C function):                Memory Interface.   (line   84)
* PyMem_DEL (C macro):                   Deprecated aliases<2>.
                                                             (line   28)
* PYMEM_DOMAIN_MEM (C macro):            Customize Memory Allocators.
                                                             (line   53)
* PYMEM_DOMAIN_OBJ (C macro):            Customize Memory Allocators.
                                                             (line   65)
* PYMEM_DOMAIN_RAW (C macro):            Customize Memory Allocators.
                                                             (line   41)
* PyMem_Free (C function):               Memory Interface.   (line   56)
* PyMem_FREE (C macro):                  Deprecated aliases<2>.
                                                             (line   25)
* PyMem_GetAllocator (C function):       Customize Memory Allocators.
                                                             (line   77)
* PyMem_Malloc (C function):             Memory Interface.   (line   19)
* PyMem_MALLOC (C macro):                Deprecated aliases<2>.
                                                             (line   13)
* PyMem_New (C macro):                   Memory Interface.   (line   68)
* PyMem_NEW (C macro):                   Deprecated aliases<2>.
                                                             (line   16)
* PyMem_RawCalloc (C function):          Raw Memory Interface.
                                                             (line   25)
* PyMem_RawFree (C function):            Raw Memory Interface.
                                                             (line   53)
* PyMem_RawMalloc (C function):          Raw Memory Interface.
                                                             (line   16)
* PyMem_RawRealloc (C function):         Raw Memory Interface.
                                                             (line   37)
* PyMem_Realloc (C function):            Memory Interface.   (line   40)
* PyMem_REALLOC (C macro):               Deprecated aliases<2>.
                                                             (line   19)
* PyMem_Resize (C macro):                Memory Interface.   (line   74)
* PyMem_RESIZE (C macro):                Deprecated aliases<2>.
                                                             (line   22)
* PyMem_SetAllocator (C function):       Customize Memory Allocators.
                                                             (line   82)
* PyMem_SetupDebugHooks (C function):    Customize Memory Allocators.
                                                             (line  125)
* PyMemAllocatorDomain (C type):         Customize Memory Allocators.
                                                             (line   37)
* PyMemAllocatorEx (C type):             Customize Memory Allocators.
                                                             (line    8)
* PyMember_GetOne (C function):          Accessing attributes of extension types.
                                                             (line   76)
* PyMember_SetOne (C function):          Accessing attributes of extension types.
                                                             (line   85)
* PyMemberDef (C type):                  Accessing attributes of extension types.
                                                             (line    6)
* PyMemberDef.doc (C member):            Accessing attributes of extension types.
                                                             (line   36)
* PyMemberDef.flags (C member):          Accessing attributes of extension types.
                                                             (line   31)
* PyMemberDef.name (C member):           Accessing attributes of extension types.
                                                             (line   14)
* PyMemberDef.offset (C member):         Accessing attributes of extension types.
                                                             (line   26)
* PyMemberDef.type (C member):           Accessing attributes of extension types.
                                                             (line   21)
* PyMemberDescr_Type (C var):            Descriptor Objects. (line   23)
* PyMemoryView_Check (C function):       MemoryView objects. (line   61)
* PyMemoryView_FromBuffer (C function):  MemoryView objects. (line   41)
* PyMemoryView_FromMemory (C function):  MemoryView objects. (line   32)
* PyMemoryView_FromObject (C function):  MemoryView objects. (line   15)
* PyMemoryView_GET_BASE (C function):    MemoryView objects. (line   75)
* PyMemoryView_GET_BUFFER (C function):  MemoryView objects. (line   67)
* PyMemoryView_GetContiguous (C function): MemoryView objects.
                                                             (line   49)
* PyMemoryView_Type (C var):             MemoryView objects. (line   10)
* PyMethod_Check (C function):           Method Objects.     (line   16)
* PyMethod_Function (C function):        Method Objects.     (line   30)
* PyMethod_GET_FUNCTION (C function):    Method Objects.     (line   34)
* PyMethod_GET_SELF (C function):        Method Objects.     (line   43)
* PyMethod_New (C function):             Method Objects.     (line   22)
* PyMethod_Self (C function):            Method Objects.     (line   39)
* PyMethod_Type (C var):                 Method Objects.     (line   10)
* PyMethodDef (C type):                  Implementing functions and methods.
                                                             (line   63)
* PyMethodDef.ml_doc (C member):         Implementing functions and methods.
                                                             (line   80)
* PyMethodDef.ml_flags (C member):       Implementing functions and methods.
                                                             (line   76)
* PyMethodDef.ml_meth (C member):        Implementing functions and methods.
                                                             (line   72)
* PyMethodDef.ml_name (C member):        Implementing functions and methods.
                                                             (line   68)
* PyMethodDescr_Type (C var):            Descriptor Objects. (line   42)
* PyMODINIT_FUNC (C macro):              Initialization function.
                                                             (line   31)
* PyModule_Add (C function):             Support functions.  (line   63)
* PyModule_AddFunctions (C function):    Support functions.  (line  158)
* PyModule_AddIntConstant (C function):  Support functions.  (line  113)
* PyModule_AddIntMacro (C macro):        Support functions.  (line  136)
* PyModule_AddObject (C function):       Support functions.  (line   79)
* PyModule_AddObjectRef (C function):    Support functions.  (line   11)
* PyModule_AddStringConstant (C function): Support functions.
                                                             (line  124)
* PyModule_AddStringMacro (C macro):     Support functions.  (line  144)
* PyModule_AddType (C function):         Support functions.  (line  148)
* PyModule_Check (C function):           Module Objects.     (line   13)
* PyModule_CheckExact (C function):      Module Objects.     (line   18)
* PyModule_Create (C function):          Creating extension modules dynamically.
                                                             (line   10)
* PyModule_Create2 (C function):         Creating extension modules dynamically.
                                                             (line   17)
* PyModule_ExecDef (C function):         Creating extension modules dynamically.
                                                             (line   64)
* PyModule_FromDefAndSpec (C function):  Creating extension modules dynamically.
                                                             (line   34)
* PyModule_FromDefAndSpec2 (C function): Creating extension modules dynamically.
                                                             (line   43)
* PyModule_GetDef (C function):          Module Objects.     (line   90)
* PyModule_GetDict (C function):         Module Objects.     (line   46)
* PyModule_GetFilename (C function):     Module Objects.     (line  113)
* PyModule_GetFilenameObject (C function): Module Objects.   (line  100)
* PyModule_GetName (C function):         Module Objects.     (line   75)
* PyModule_GetNameObject (C function):   Module Objects.     (line   64)
* PyModule_GetState (C function):        Module Objects.     (line   84)
* PyModule_New (C function):             Module Objects.     (line   41)
* PyModule_NewObject (C function):       Module Objects.     (line   23)
* PyModule_SetDocString (C function):    Support functions.  (line  180)
* PyModule_Type (C var):                 Module Objects.     (line    6)
* PyModuleDef (C type):                  Module definitions. (line   22)
* PyModuleDef_Init (C function):         Multi-phase initialization.
                                                             (line   11)
* PyModuleDef_Slot (C type):             Module slots.       (line    6)
* PyModuleDef_Slot.slot (C member):      Module slots.       (line    8)
* PyModuleDef_Slot.value (C member):     Module slots.       (line   13)
* PyModuleDef.m_base (C member):         Module definitions. (line   30)
* PyModuleDef.m_clear (C member):        Module definitions. (line  100)
* PyModuleDef.m_doc (C member):          Module definitions. (line   38)
* PyModuleDef.m_free (C member):         Module definitions. (line  122)
* PyModuleDef.m_methods (C member):      Module definitions. (line   67)
* PyModuleDef.m_name (C member):         Module definitions. (line   34)
* PyModuleDef.m_size (C member):         Module definitions. (line   43)
* PyModuleDef.m_slots (C member):        Module definitions. (line   73)
* PyModuleDef.m_slots.m_reload (C member): Module definitions.
                                                             (line   82)
* PyModuleDef.m_traverse (C member):     Module definitions. (line   84)
* PyMonitoring_EnterScope (C function):  Managing the Monitoring State.
                                                             (line    9)
* PyMonitoring_ExitScope (C function):   Managing the Monitoring State.
                                                             (line   98)
* PyMonitoring_FireBranchLeftEvent (C function): Generating Execution Events.
                                                             (line   70)
* PyMonitoring_FireBranchRightEvent (C function): Generating Execution Events.
                                                             (line   76)
* PyMonitoring_FireCallEvent (C function): Generating Execution Events.
                                                             (line   53)
* PyMonitoring_FireCRaiseEvent (C function): Generating Execution Events.
                                                             (line   99)
* PyMonitoring_FireCReturnEvent (C function): Generating Execution Events.
                                                             (line   82)
* PyMonitoring_FireExceptionHandledEvent (C function): Generating Execution Events.
                                                             (line  111)
* PyMonitoring_FireJumpEvent (C function): Generating Execution Events.
                                                             (line   64)
* PyMonitoring_FireLineEvent (C function): Generating Execution Events.
                                                             (line   59)
* PyMonitoring_FirePyResumeEvent (C function): Generating Execution Events.
                                                             (line   38)
* PyMonitoring_FirePyReturnEvent (C function): Generating Execution Events.
                                                             (line   43)
* PyMonitoring_FirePyStartEvent (C function): Generating Execution Events.
                                                             (line   33)
* PyMonitoring_FirePyThrowEvent (C function): Generating Execution Events.
                                                             (line   87)
* PyMonitoring_FirePyUnwindEvent (C function): Generating Execution Events.
                                                             (line  117)
* PyMonitoring_FirePyYieldEvent (C function): Generating Execution Events.
                                                             (line   48)
* PyMonitoring_FireRaiseEvent (C function): Generating Execution Events.
                                                             (line   93)
* PyMonitoring_FireReraiseEvent (C function): Generating Execution Events.
                                                             (line  105)
* PyMonitoring_FireStopIterationEvent (C function): Generating Execution Events.
                                                             (line  123)
* PyMonitoringState (C type):            Generating Execution Events.
                                                             (line   22)
* PyMutex (C type):                      Synchronization Primitives<2>.
                                                             (line    8)
* PyMutex_IsLocked (C function):         Synchronization Primitives<2>.
                                                             (line   41)
* PyMutex_Lock (C function):             Synchronization Primitives<2>.
                                                             (line   25)
* PyMutex_Unlock (C function):           Synchronization Primitives<2>.
                                                             (line   34)
* PyNumber_Absolute (C function):        Number Protocol.    (line   99)
* PyNumber_Add (C function):             Number Protocol.    (line   14)
* PyNumber_And (C function):             Number Protocol.    (line  126)
* PyNumber_AsSsize_t (C function):       Number Protocol.    (line  298)
* PyNumber_Check (C function):           Number Protocol.    (line    6)
* PyNumber_Divmod (C function):          Number Protocol.    (line   69)
* PyNumber_Float (C function):           Number Protocol.    (line  270)
* PyNumber_FloorDivide (C function):     Number Protocol.    (line   44)
* PyNumber_Index (C function):           Number Protocol.    (line  278)
* PyNumber_InPlaceAdd (C function):      Number Protocol.    (line  147)
* PyNumber_InPlaceAnd (C function):      Number Protocol.    (line  238)
* PyNumber_InPlaceFloorDivide (C function): Number Protocol. (line  181)
* PyNumber_InPlaceLshift (C function):   Number Protocol.    (line  222)
* PyNumber_InPlaceMatrixMultiply (C function): Number Protocol.
                                                             (line  171)
* PyNumber_InPlaceMultiply (C function): Number Protocol.    (line  163)
* PyNumber_InPlaceOr (C function):       Number Protocol.    (line  254)
* PyNumber_InPlacePower (C function):    Number Protocol.    (line  209)
* PyNumber_InPlaceRemainder (C function): Number Protocol.   (line  201)
* PyNumber_InPlaceRshift (C function):   Number Protocol.    (line  230)
* PyNumber_InPlaceSubtract (C function): Number Protocol.    (line  155)
* PyNumber_InPlaceTrueDivide (C function): Number Protocol.  (line  189)
* PyNumber_InPlaceXor (C function):      Number Protocol.    (line  246)
* PyNumber_Invert (C function):          Number Protocol.    (line  106)
* PyNumber_Long (C function):            Number Protocol.    (line  262)
* PyNumber_Lshift (C function):          Number Protocol.    (line  112)
* PyNumber_MatrixMultiply (C function):  Number Protocol.    (line   35)
* PyNumber_Multiply (C function):        Number Protocol.    (line   28)
* PyNumber_Negative (C function):        Number Protocol.    (line   89)
* PyNumber_Or (C function):              Number Protocol.    (line  140)
* PyNumber_Positive (C function):        Number Protocol.    (line   94)
* PyNumber_Power (C function):           Number Protocol.    (line   78)
* PyNumber_Remainder (C function):       Number Protocol.    (line   62)
* PyNumber_Rshift (C function):          Number Protocol.    (line  119)
* PyNumber_Subtract (C function):        Number Protocol.    (line   21)
* PyNumber_ToBase (C function):          Number Protocol.    (line  288)
* PyNumber_TrueDivide (C function):      Number Protocol.    (line   51)
* PyNumber_Xor (C function):             Number Protocol.    (line  133)
* PyNumberMethods (C type):              Number Object Structures.
                                                             (line    6)
* PyNumberMethods.nb_absolute (C member): Number Object Structures.
                                                             (line  117)
* PyNumberMethods.nb_add (C member):     Number Object Structures.
                                                             (line   70)
* PyNumberMethods.nb_and (C member):     Number Object Structures.
                                                             (line  146)
* PyNumberMethods.nb_bool (C member):    Number Object Structures.
                                                             (line  123)
* PyNumberMethods.nb_divmod (C member):  Number Object Structures.
                                                             (line   93)
* PyNumberMethods.nb_float (C member):   Number Object Structures.
                                                             (line  168)
* PyNumberMethods.nb_floor_divide (C member): Number Object Structures.
                                                             (line  234)
* PyNumberMethods.nb_index (C member):   Number Object Structures.
                                                             (line  259)
* PyNumberMethods.nb_inplace_add (C member): Number Object Structures.
                                                             (line  174)
* PyNumberMethods.nb_inplace_and (C member): Number Object Structures.
                                                             (line  216)
* PyNumberMethods.nb_inplace_floor_divide (C member): Number Object Structures.
                                                             (line  246)
* PyNumberMethods.nb_inplace_lshift (C member): Number Object Structures.
                                                             (line  204)
* PyNumberMethods.nb_inplace_matrix_multiply (C member): Number Object Structures.
                                                             (line  271)
* PyNumberMethods.nb_inplace_multiply (C member): Number Object Structures.
                                                             (line  186)
* PyNumberMethods.nb_inplace_or (C member): Number Object Structures.
                                                             (line  228)
* PyNumberMethods.nb_inplace_power (C member): Number Object Structures.
                                                             (line  198)
* PyNumberMethods.nb_inplace_remainder (C member): Number Object Structures.
                                                             (line  192)
* PyNumberMethods.nb_inplace_rshift (C member): Number Object Structures.
                                                             (line  210)
* PyNumberMethods.nb_inplace_subtract (C member): Number Object Structures.
                                                             (line  180)
* PyNumberMethods.nb_inplace_true_divide (C member): Number Object Structures.
                                                             (line  253)
* PyNumberMethods.nb_inplace_xor (C member): Number Object Structures.
                                                             (line  222)
* PyNumberMethods.nb_int (C member):     Number Object Structures.
                                                             (line  161)
* PyNumberMethods.nb_invert (C member):  Number Object Structures.
                                                             (line  128)
* PyNumberMethods.nb_lshift (C member):  Number Object Structures.
                                                             (line  134)
* PyNumberMethods.nb_matrix_multiply (C member): Number Object Structures.
                                                             (line  265)
* PyNumberMethods.nb_multiply (C member): Number Object Structures.
                                                             (line   81)
* PyNumberMethods.nb_negative (C member): Number Object Structures.
                                                             (line  105)
* PyNumberMethods.nb_or (C member):      Number Object Structures.
                                                             (line  156)
* PyNumberMethods.nb_positive (C member): Number Object Structures.
                                                             (line  111)
* PyNumberMethods.nb_power (C member):   Number Object Structures.
                                                             (line   99)
* PyNumberMethods.nb_remainder (C member): Number Object Structures.
                                                             (line   87)
* PyNumberMethods.nb_reserved (C member): Number Object Structures.
                                                             (line  166)
* PyNumberMethods.nb_rshift (C member):  Number Object Structures.
                                                             (line  140)
* PyNumberMethods.nb_subtract (C member): Number Object Structures.
                                                             (line   75)
* PyNumberMethods.nb_true_divide (C member): Number Object Structures.
                                                             (line  240)
* PyNumberMethods.nb_xor (C member):     Number Object Structures.
                                                             (line  151)
* PyObject (C type):                     Base object types and macros.
                                                             (line   14)
* PyObject_ASCII (C function):           Object Protocol.    (line  343)
* PyObject_AsFileDescriptor (C function): File Objects.      (line   33)
* PyObject_Bytes (C function):           Object Protocol.    (line  366)
* PyObject_Call (C function):            Object Calling API. (line   57)
* PyObject_CallFinalizer (C function):   Functions<14>.      (line    9)
* PyObject_CallFinalizerFromDealloc (C function): Functions<14>.
                                                             (line   21)
* PyObject_CallFunction (C function):    Object Calling API. (line  108)
* PyObject_CallFunctionObjArgs (C function): Object Calling API.
                                                             (line  150)
* PyObject_CallMethod (C function):      Object Calling API. (line  127)
* PyObject_CallMethodNoArgs (C function): Object Calling API.
                                                             (line  175)
* PyObject_CallMethodObjArgs (C function): Object Calling API.
                                                             (line  163)
* PyObject_CallMethodOneArg (C function): Object Calling API.
                                                             (line  187)
* PyObject_CallNoArgs (C function):      Object Calling API. (line   73)
* PyObject_CallObject (C function):      Calling Python Functions from C.
                                                             (line   64)
* PyObject_CallObject (C function) <1>:  Object Calling API. (line   96)
* PyObject_Calloc (C function):          Object allocators.  (line   30)
* PyObject_CallOneArg (C function):      Object Calling API. (line   85)
* PyObject_CheckBuffer (C function):     Buffer-related functions.
                                                             (line    6)
* PyObject_ClearManagedDict (C function): Object Protocol.   (line  595)
* PyObject_ClearWeakRefs (C function):   Weak Reference Objects<2>.
                                                             (line  117)
* PyObject_CopyData (C function):        Buffer-related functions.
                                                             (line   80)
* PyObject_DEL (C macro):                Deprecated aliases<3>.
                                                             (line   34)
* PyObject_Del (C macro):                Deprecated aliases<3>.
                                                             (line   37)
* PyObject_DelAttr (C function):         Object Protocol.    (line  241)
* PyObject_DelAttrString (C function):   Object Protocol.    (line  247)
* PyObject_DelItem (C function):         Object Protocol.    (line  498)
* PyObject_DelItemString (C function):   Object Protocol.    (line  503)
* PyObject_Dir (C function):             Object Protocol.    (line  509)
* PyObject_Format (C function):          Object Protocol.    (line  320)
* PyObject_Free (C function):            Object allocators.  (line   58)
* PyObject_FREE (C macro):               Deprecated aliases<3>.
                                                             (line   31)
* PyObject_GC_Del (C function):          Supporting Cyclic Garbage Collection.
                                                             (line  181)
* PyObject_GC_IsFinalized (C function):  Supporting Cyclic Garbage Collection.
                                                             (line  171)
* PyObject_GC_IsTracked (C function):    Supporting Cyclic Garbage Collection.
                                                             (line  161)
* PyObject_GC_New (C macro):             Supporting Cyclic Garbage Collection.
                                                             (line   56)
* PyObject_GC_NewVar (C macro):          Supporting Cyclic Garbage Collection.
                                                             (line   83)
* PyObject_GC_Resize (C macro):          Supporting Cyclic Garbage Collection.
                                                             (line  135)
* PyObject_GC_Track (C function):        Supporting Cyclic Garbage Collection.
                                                             (line  145)
* PyObject_GC_UnTrack (C function):      Supporting Cyclic Garbage Collection.
                                                             (line  207)
* PyObject_GenericGetAttr (C function):  Object Protocol.    (line  187)
* PyObject_GenericGetDict (C function):  Object Protocol.    (line  262)
* PyObject_GenericHash (C function):     PyHash API.         (line  171)
* PyObject_GenericSetAttr (C function):  Object Protocol.    (line  229)
* PyObject_GenericSetDict (C function):  Object Protocol.    (line  279)
* PyObject_GetAIter (C function):        Object Protocol.    (line  533)
* PyObject_GetArenaAllocator (C function): Customize pymalloc Arena Allocator.
                                                             (line   26)
* PyObject_GetAttr (C function):         Object Protocol.    (line  143)
* PyObject_GetAttrString (C function):   Object Protocol.    (line  153)
* PyObject_GetBuffer (C function):       Buffer-related functions.
                                                             (line   12)
* PyObject_GetItem (C function):         Object Protocol.    (line  484)
* PyObject_GetItemData (C function):     Object Protocol.    (line  574)
* PyObject_GetIter (C function):         Object Protocol.    (line  519)
* PyObject_GetOptionalAttr (C function): Object Protocol.    (line  163)
* PyObject_GetOptionalAttrString (C function): Object Protocol.
                                                             (line  178)
* PyObject_GetTypeData (C function):     Object Protocol.    (line  544)
* PyObject_HasAttr (C function):         Object Protocol.    (line  115)
* PyObject_HasAttrString (C function):   Object Protocol.    (line  128)
* PyObject_HasAttrStringWithError (C function): Object Protocol.
                                                             (line  106)
* PyObject_HasAttrWithError (C function): Object Protocol.   (line   97)
* PyObject_Hash (C function):            Object Protocol.    (line  418)
* PyObject_HashNotImplemented (C function): Object Protocol. (line  428)
* PyObject_HEAD (C macro):               Base object types and macros.
                                                             (line   69)
* PyObject_HEAD_INIT (C macro):          Base object types and macros.
                                                             (line  171)
* PyObject_Init (C function):            Allocating Objects on the Heap.
                                                             (line   13)
* PyObject_INIT (C macro):               Deprecated aliases<3>.
                                                             (line   19)
* PyObject_INIT_VAR (C macro):           Deprecated aliases<3>.
                                                             (line   22)
* PyObject_InitVar (C function):         Allocating Objects on the Heap.
                                                             (line   32)
* PyObject_IS_GC (C function):           Supporting Cyclic Garbage Collection.
                                                             (line  153)
* PyObject_IsInstance (C function):      Object Protocol.    (line  397)
* PyObject_IsSubclass (C function):      Object Protocol.    (line  376)
* PyObject_IsTrue (C function):          Object Protocol.    (line  436)
* PyObject_Length (C function):          Object Protocol.    (line  464)
* PyObject_LengthHint (C function):      Object Protocol.    (line  473)
* PyObject_Malloc (C function):          Object allocators.  (line   21)
* PyObject_MALLOC (C macro):             Deprecated aliases<3>.
                                                             (line   25)
* PyObject_New (C macro):                Allocating Objects on the Heap.
                                                             (line   42)
* PyObject_NEW (C macro):                Deprecated aliases<3>.
                                                             (line   13)
* PyObject_NEW_VAR (C macro):            Deprecated aliases<3>.
                                                             (line   16)
* PyObject_NewVar (C macro):             Allocating Objects on the Heap.
                                                             (line   91)
* PyObject_Not (C function):             Object Protocol.    (line  441)
* PyObject_Print (C function):           Object Protocol.    (line   89)
* PyObject_Realloc (C function):         Object allocators.  (line   42)
* PyObject_REALLOC (C macro):            Deprecated aliases<3>.
                                                             (line   28)
* PyObject_Repr (C function):            Object Protocol.    (line  330)
* PyObject_RichCompare (C function):     Object Protocol.    (line  297)
* PyObject_RichCompareBool (C function): Object Protocol.    (line  309)
* PyObject_SelfIter (C function):        Object Protocol.    (line  527)
* PyObject_SetArenaAllocator (C function): Customize pymalloc Arena Allocator.
                                                             (line   31)
* PyObject_SetAttr (C function):         Object Protocol.    (line  199)
* PyObject_SetAttrString (C function):   Object Protocol.    (line  211)
* PyObject_SetItem (C function):         Object Protocol.    (line  491)
* PyObject_Size (C function):            Object Protocol.    (line  464)
* PyObject_Str (C function):             Object Protocol.    (line  354)
* PyObject_Type (C function):            Object Protocol.    (line  446)
* PyObject_TypeCheck (C function):       Object Protocol.    (line  459)
* PyObject_VAR_HEAD (C macro):           Base object types and macros.
                                                             (line   79)
* PyObject_Vectorcall (C function):      Object Calling API. (line  199)
* PyObject_VectorcallDict (C function):  Object Calling API. (line  217)
* PyObject_VectorcallMethod (C function): Object Calling API.
                                                             (line  233)
* PyObject_VisitManagedDict (C function): Object Protocol.   (line  585)
* PyObject.ob_refcnt (C member):         Base object types and macros.
                                                             (line   27)
* PyObject.ob_type (C member):           Base object types and macros.
                                                             (line   37)
* PyObjectArenaAllocator (C type):       Customize pymalloc Arena Allocator.
                                                             (line    8)
* PyODict_Check (C function):            Ordered Dictionaries.
                                                             (line   16)
* PyODict_CheckExact (C function):       Ordered Dictionaries.
                                                             (line   22)
* PyODict_Contains (C macro):            Ordered Dictionaries.
                                                             (line   79)
* PyODict_DelItem (C function):          Ordered Dictionaries.
                                                             (line   57)
* PyODict_GetItem (C macro):             Ordered Dictionaries.
                                                             (line   70)
* PyODict_GetItemString (C macro):       Ordered Dictionaries.
                                                             (line   76)
* PyODict_GetItemWithError (C macro):    Ordered Dictionaries.
                                                             (line   73)
* PyODict_New (C function):              Ordered Dictionaries.
                                                             (line   42)
* PyODict_SetItem (C function):          Ordered Dictionaries.
                                                             (line   48)
* PyODict_Size (C macro):                Ordered Dictionaries.
                                                             (line   82)
* PyODict_SIZE (C macro):                Ordered Dictionaries.
                                                             (line   85)
* PyODict_Type (C var):                  Ordered Dictionaries.
                                                             (line   11)
* PyODictItems_Type (C var):             Ordered Dictionaries.
                                                             (line   37)
* PyODictIter_Type (C var):              Other Iterator Objects.
                                                             (line   48)
* PyODictKeys_Type (C var):              Ordered Dictionaries.
                                                             (line   28)
* PyODictValues_Type (C var):            Ordered Dictionaries.
                                                             (line   32)
* PyOS_AfterFork (C function):           Operating System Utilities.
                                                             (line   79)
* PyOS_AfterFork_Child (C function):     Operating System Utilities.
                                                             (line   56)
* PyOS_AfterFork_Parent (C function):    Operating System Utilities.
                                                             (line   42)
* PyOS_BeforeFork (C function):          Operating System Utilities.
                                                             (line   29)
* PyOS_CheckStack (C function):          Operating System Utilities.
                                                             (line   89)
* PyOS_double_to_string (C function):    String conversion and formatting.
                                                             (line  118)
* PyOS_FSPath (C function):              Operating System Utilities.
                                                             (line    6)
* PyOS_getsig (C function):              Operating System Utilities.
                                                             (line  103)
* PyOS_InputHook (C var):                The Very High Level Layer.
                                                             (line  144)
* PyOS_InterruptOccurred (C function):   Operating System Utilities.
                                                             (line  115)
* PyOS_mystricmp (C function):           String conversion and formatting.
                                                             (line  172)
* PyOS_mystrnicmp (C function):          String conversion and formatting.
                                                             (line  172)
* PyOS_ReadlineFunctionPointer (C var):  The Very High Level Layer.
                                                             (line  156)
* PyOS_setsig (C function):              Operating System Utilities.
                                                             (line  108)
* PyOS_sighandler_t (C type):            Operating System Utilities.
                                                             (line  100)
* PyOS_snprintf (C function):            String conversion and formatting.
                                                             (line    8)
* PyOS_stricmp (C function):             String conversion and formatting.
                                                             (line  191)
* PyOS_string_to_double (C function):    String conversion and formatting.
                                                             (line   85)
* PyOS_strnicmp (C function):            String conversion and formatting.
                                                             (line  191)
* PyOS_strtol (C function):              String conversion and formatting.
                                                             (line   72)
* PyOS_strtoul (C function):             String conversion and formatting.
                                                             (line   50)
* PyOS_vsnprintf (C function):           String conversion and formatting.
                                                             (line   14)
* PyPickleBuffer_Check (C function):     Pickle buffer objects.
                                                             (line   18)
* PyPickleBuffer_FromObject (C function): Pickle buffer objects.
                                                             (line   23)
* PyPickleBuffer_GetBuffer (C function): Pickle buffer objects.
                                                             (line   37)
* PyPickleBuffer_Release (C function):   Pickle buffer objects.
                                                             (line   51)
* PyPickleBuffer_Type (C var):           Pickle buffer objects.
                                                             (line   12)
* PyPreConfig (C type):                  PyPreConfig.        (line    6)
* PyPreConfig_InitIsolatedConfig (C function): PyPreConfig.  (line   18)
* PyPreConfig_InitPythonConfig (C function): PyPreConfig.    (line   12)
* PyPreConfig.allocator (C member):      PyPreConfig.        (line   26)
* PyPreConfig.coerce_c_locale (C member): PyPreConfig.       (line   82)
* PyPreConfig.coerce_c_locale_warn (C member): PyPreConfig.  (line   93)
* PyPreConfig.configure_locale (C member): PyPreConfig.      (line   71)
* PyPreConfig.dev_mode (C member):       PyPreConfig.        (line   99)
* PyPreConfig.isolated (C member):       PyPreConfig.        (line  106)
* PyPreConfig.legacy_windows_fs_encoding (C member): PyPreConfig.
                                                             (line  112)
* PyPreConfig.parse_argv (C member):     PyPreConfig.        (line  131)
* PyPreConfig.use_environment (C member): PyPreConfig.       (line  140)
* PyPreConfig.utf8_mode (C member):      PyPreConfig.        (line  147)
* PyProperty_Type (C var):               Descriptor Objects. (line    9)
* PyRange_Check (C function):            Range Objects.      (line   10)
* PyRange_Type (C var):                  Range Objects.      (line    6)
* PyRangeIter_Type (C var):              Other Iterator Objects.
                                                             (line   24)
* PyRefTracer (C type):                  Reference tracing.  (line    8)
* PyRefTracer_CREATE (C var):            Reference tracing.  (line   21)
* PyRefTracer_DESTROY (C var):           Reference tracing.  (line   26)
* PyRefTracer_GetTracer (C function):    Reference tracing.  (line   51)
* PyRefTracer_SetTracer (C function):    Reference tracing.  (line   31)
* PyReversed_Type (C var):               Builtin Iterator Types.
                                                             (line   24)
* PyRun_AnyFile (C function):            The Very High Level Layer.
                                                             (line   25)
* PyRun_AnyFileEx (C function):          The Very High Level Layer.
                                                             (line   37)
* PyRun_AnyFileExFlags (C function):     The Very High Level Layer.
                                                             (line   43)
* PyRun_AnyFileFlags (C function):       The Very High Level Layer.
                                                             (line   31)
* PyRun_File (C function):               The Very High Level Layer.
                                                             (line  199)
* PyRun_FileEx (C function):             The Very High Level Layer.
                                                             (line  205)
* PyRun_FileExFlags (C function):        The Very High Level Layer.
                                                             (line  219)
* PyRun_FileFlags (C function):          The Very High Level Layer.
                                                             (line  212)
* PyRun_InteractiveLoop (C function):    The Very High Level Layer.
                                                             (line  128)
* PyRun_InteractiveLoopFlags (C function): The Very High Level Layer.
                                                             (line  135)
* PyRun_InteractiveOne (C function):     The Very High Level Layer.
                                                             (line  114)
* PyRun_InteractiveOneFlags (C function): The Very High Level Layer.
                                                             (line  121)
* PyRun_InteractiveOneObject (C function): The Very High Level Layer.
                                                             (line  100)
* PyRun_SimpleFile (C function):         The Very High Level Layer.
                                                             (line   75)
* PyRun_SimpleFileEx (C function):       The Very High Level Layer.
                                                             (line   81)
* PyRun_SimpleFileExFlags (C function):  The Very High Level Layer.
                                                             (line   87)
* PyRun_SimpleString (C function):       The Very High Level Layer.
                                                             (line   55)
* PyRun_SimpleStringFlags (C function):  The Very High Level Layer.
                                                             (line   61)
* PyRun_String (C function):             The Very High Level Layer.
                                                             (line  180)
* PyRun_StringFlags (C function):        The Very High Level Layer.
                                                             (line  186)
* PySendResult (C type):                 Iterator Protocol.  (line   42)
* PySeqIter_Check (C function):          Iterator Objects.   (line   18)
* PySeqIter_New (C function):            Iterator Objects.   (line   23)
* PySeqIter_Type (C var):                Iterator Objects.   (line   12)
* PySequence_Check (C function):         Sequence Protocol.  (line    6)
* PySequence_Concat (C function):        Sequence Protocol.  (line   21)
* PySequence_Contains (C function):      Sequence Protocol.  (line   99)
* PySequence_Count (C function):         Sequence Protocol.  (line   92)
* PySequence_DelItem (C function):       Sequence Protocol.  (line   75)
* PySequence_DelSlice (C function):      Sequence Protocol.  (line   86)
* PySequence_Fast (C function):          Sequence Protocol.  (line  135)
* PySequence_Fast_GET_ITEM (C function): Sequence Protocol.  (line  159)
* PySequence_Fast_GET_SIZE (C function): Sequence Protocol.  (line  150)
* PySequence_Fast_ITEMS (C function):    Sequence Protocol.  (line  166)
* PySequence_GetItem (C function):       Reference Count Details.
                                                             (line  117)
* PySequence_GetItem (C function) <1>:   Sequence Protocol.  (line   51)
* PySequence_GetSlice (C function):      Sequence Protocol.  (line   57)
* PySequence_In (C function):            Sequence Protocol.  (line  105)
* PySequence_Index (C function):         Sequence Protocol.  (line  112)
* PySequence_InPlaceConcat (C function): Sequence Protocol.  (line   35)
* PySequence_InPlaceRepeat (C function): Sequence Protocol.  (line   43)
* PySequence_ITEM (C function):          Sequence Protocol.  (line  177)
* PySequence_Length (C function):        Sequence Protocol.  (line   14)
* PySequence_List (C function):          Sequence Protocol.  (line  118)
* PySequence_Repeat (C function):        Sequence Protocol.  (line   28)
* PySequence_SetItem (C function):       Sequence Protocol.  (line   64)
* PySequence_SetSlice (C function):      Sequence Protocol.  (line   80)
* PySequence_Size (C function):          Sequence Protocol.  (line   14)
* PySequence_Tuple (C function):         Sequence Protocol.  (line  125)
* PySequenceMethods (C type):            Sequence Object Structures.
                                                             (line    6)
* PySequenceMethods.sq_ass_item (C member): Sequence Object Structures.
                                                             (line   62)
* PySequenceMethods.sq_concat (C member): Sequence Object Structures.
                                                             (line   22)
* PySequenceMethods.sq_contains (C member): Sequence Object Structures.
                                                             (line   75)
* PySequenceMethods.sq_inplace_concat (C member): Sequence Object Structures.
                                                             (line   86)
* PySequenceMethods.sq_inplace_repeat (C member): Sequence Object Structures.
                                                             (line  100)
* PySequenceMethods.sq_item (C member):  Sequence Object Structures.
                                                             (line   43)
* PySequenceMethods.sq_length (C member): Sequence Object Structures.
                                                             (line   11)
* PySequenceMethods.sq_repeat (C member): Sequence Object Structures.
                                                             (line   32)
* PySet_Add (C function):                Set Objects.        (line  120)
* PySet_Check (C function):              Set Objects.        (line   44)
* PySet_CheckExact (C function):         Set Objects.        (line   60)
* PySet_Clear (C function):              Set Objects.        (line  153)
* PySet_Contains (C function):           Set Objects.        (line  111)
* PySet_Discard (C function):            Set Objects.        (line  135)
* PySet_GET_SIZE (C function):           Set Objects.        (line  107)
* PySet_MINSIZE (C macro):               Deprecated API<3>.  (line    6)
* PySet_New (C function):                Set Objects.        (line   78)
* PySet_Pop (C function):                Set Objects.        (line  145)
* PySet_Size (C function):               Set Objects.        (line   99)
* PySet_Type (C var):                    Set Objects.        (line   31)
* PySetIter_Type (C var):                Other Iterator Objects.
                                                             (line   18)
* PySetObject (C type):                  Set Objects.        (line   19)
* PySignal_SetWakeupFd (C function):     Signal Handling<2>. (line   69)
* PySlice_AdjustIndices (C function):    Slice Objects.      (line  100)
* PySlice_Check (C function):            Slice Objects.      (line   11)
* PySlice_GetIndices (C function):       Slice Objects.      (line   28)
* PySlice_GetIndicesEx (C function):     Slice Objects.      (line   44)
* PySlice_New (C function):              Slice Objects.      (line   16)
* PySlice_Type (C var):                  Slice Objects.      (line    6)
* PySlice_Unpack (C function):           Slice Objects.      (line   87)
* PyState_AddModule (C function):        Module lookup single-phase initialization.
                                                             (line   25)
* PyState_FindModule (C function):       Module lookup single-phase initialization.
                                                             (line   15)
* PyState_RemoveModule (C function):     Module lookup single-phase initialization.
                                                             (line   53)
* PyStaticMethod_New (C function):       Built-in descriptors.
                                                             (line   38)
* PyStaticMethod_Type (C var):           Built-in descriptors.
                                                             (line   33)
* PyStatus (C type):                     PyStatus.           (line    6)
* PyStatus_Error (C function):           PyStatus.           (line   34)
* PyStatus_Exception (C function):       PyStatus.           (line   51)
* PyStatus_Exit (C function):            PyStatus.           (line   45)
* PyStatus_IsError (C function):         PyStatus.           (line   57)
* PyStatus_IsExit (C function):          PyStatus.           (line   61)
* PyStatus_NoMemory (C function):        PyStatus.           (line   41)
* PyStatus_Ok (C function):              PyStatus.           (line   30)
* PyStatus.err_msg (C member):           PyStatus.           (line   20)
* PyStatus.exitcode (C member):          PyStatus.           (line   16)
* PyStatus.func (C member):              PyStatus.           (line   24)
* PyStdPrinter_Type (C var):             Deprecated API<4>.  (line   15)
* PyStructSequence_Desc (C type):        Struct Sequence Objects.
                                                             (line   33)
* PyStructSequence_Desc.doc (C member):  Struct Sequence Objects.
                                                             (line   42)
* PyStructSequence_Desc.fields (C member): Struct Sequence Objects.
                                                             (line   46)
* PyStructSequence_Desc.n_in_sequence (C member): Struct Sequence Objects.
                                                             (line   51)
* PyStructSequence_Desc.name (C member): Struct Sequence Objects.
                                                             (line   37)
* PyStructSequence_Field (C type):       Struct Sequence Objects.
                                                             (line   56)
* PyStructSequence_Field.doc (C member): Struct Sequence Objects.
                                                             (line   70)
* PyStructSequence_Field.name (C member): Struct Sequence Objects.
                                                             (line   64)
* PyStructSequence_GET_ITEM (C function): Struct Sequence Objects.
                                                             (line   97)
* PyStructSequence_GetItem (C function): Struct Sequence Objects.
                                                             (line   88)
* PyStructSequence_InitType (C function): Struct Sequence Objects.
                                                             (line   20)
* PyStructSequence_InitType2 (C function): Struct Sequence Objects.
                                                             (line   25)
* PyStructSequence_New (C function):     Struct Sequence Objects.
                                                             (line   80)
* PyStructSequence_NewType (C function): Struct Sequence Objects.
                                                             (line   11)
* PyStructSequence_SET_ITEM (C function): Struct Sequence Objects.
                                                             (line  117)
* PyStructSequence_SetItem (C function): Struct Sequence Objects.
                                                             (line  105)
* PyStructSequence_UnnamedField (C var): Struct Sequence Objects.
                                                             (line   74)
* PySuper_Type (C var):                  Built-in descriptors.
                                                             (line    6)
* PySys_AddAuditHook (C function):       System Functions.   (line  117)
* PySys_Audit (C function):              System Functions.   (line   76)
* PySys_AuditTuple (C function):         System Functions.   (line  109)
* PySys_FormatStderr (C function):       System Functions.   (line   60)
* PySys_FormatStdout (C function):       System Functions.   (line   52)
* PySys_GetObject (C function):          System Functions.   (line   11)
* PySys_GetXOptions (C function):        System Functions.   (line   67)
* PySys_ResetWarnOptions (C function):   System Functions.   (line   23)
* PySys_SetArgv (C function):            Process-wide parameters.
                                                             (line  275)
* PySys_SetArgvEx (C function):          Process-wide parameters.
                                                             (line  223)
* PySys_SetObject (C function):          System Functions.   (line   17)
* PySys_WriteStderr (C function):        System Functions.   (line   48)
* PySys_WriteStdout (C function):        System Functions.   (line   31)
* Python 3000:                           Glossary.           (line 1442)
* Python Editor:                         IDLE — Python editor and shell<2>.
                                                             (line    8)
* Python Enhancement Proposals; PEP 0007#documentation-strings: Documentation<28>.
                                                             (line   35)
* Python Enhancement Proposals; PEP 0249#threadsafety: Module constants.
                                                             (line  108)
* Python Enhancement Proposals; PEP 0453#recommendations-for-downstream-distributors: Bootstrapping pip By Default.
                                                             (line   39)
* Python Enhancement Proposals; PEP 0477#disabling-ensurepip-by-downstream-distributors: Bootstrapping pip By Default<2>.
                                                             (line   29)
* Python Enhancement Proposals; PEP 0564#annex-clocks-resolution-in-python: PEP 564 New Time Functions With Nanosecond Resolution.
                                                             (line   26)
* Python Enhancement Proposals; PEP 0626#out-of-process-debuggers-and-profilers: Code Objects.
                                                             (line  105)
* Python Enhancement Proposals; PEP 0632#migration-advice: Sommario – Punti salienti del rilascio.
                                                             (line  118)
* Python Enhancement Proposals; PEP 0683: Reference Counting.
                                                             (line   70)
* Python Enhancement Proposals; PEP 1:   New Development Process.
                                                             (line   67)
* Python Enhancement Proposals; PEP 1 <1>: New Development Process.
                                                             (line   82)
* Python Enhancement Proposals; PEP 1 <2>: Glossary.         (line 1408)
* Python Enhancement Proposals; PEP 100: Unicode<2>.         (line   15)
* Python Enhancement Proposals; PEP 11:  Build changes.      (line   19)
* Python Enhancement Proposals; PEP 11 <1>: Support for mobile platforms.
                                                             (line    6)
* Python Enhancement Proposals; PEP 11 <2>: Support for mobile platforms.
                                                             (line   15)
* Python Enhancement Proposals; PEP 11 <3>: Build Changes.   (line    6)
* Python Enhancement Proposals; PEP 11 <4>: Build Changes.   (line   10)
* Python Enhancement Proposals; PEP 11 <5>: Build Changes.   (line   14)
* Python Enhancement Proposals; PEP 11 <6>: Build Changes.   (line   17)
* Python Enhancement Proposals; PEP 11 <7>: Build Changes<2>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 11 <8>: PEP 538 Legacy C Locale Coercion.
                                                             (line   19)
* Python Enhancement Proposals; PEP 11 <9>: Unsupported Operating Systems.
                                                             (line    6)
* Python Enhancement Proposals; PEP 11 <10>: Library Changes.
                                                             (line   15)
* Python Enhancement Proposals; PEP 11 <11>: Build<32>.      (line   56)
* Python Enhancement Proposals; PEP 11 <12>: Build<32>.      (line  107)
* Python Enhancement Proposals; PEP 11 <13>: Build<70>.      (line   14)
* Python Enhancement Proposals; PEP 11 <14>: Build Requirements.
                                                             (line   28)
* Python Enhancement Proposals; PEP 11 <15>: Supported Windows versions.
                                                             (line    6)
* Python Enhancement Proposals; PEP 11#tier-2: Summary – Release Highlights.
                                                             (line  139)
* Python Enhancement Proposals; PEP 11#tier-3: Summary – Release highlights.
                                                             (line   74)
* Python Enhancement Proposals; PEP 11#tier-3 <1>: Build changes.
                                                             (line    6)
* Python Enhancement Proposals; PEP 11#tier-3 <2>: Summary – Release Highlights.
                                                             (line  134)
* Python Enhancement Proposals; PEP 11#tier-3 <3>: Summary – Release Highlights.
                                                             (line  137)
* Python Enhancement Proposals; PEP 11#tier-3 <4>: Build Changes<2>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 201: New Development Process.
                                                             (line   86)
* Python Enhancement Proposals; PEP 205: PEP 205 Weak References.
                                                             (line   82)
* Python Enhancement Proposals; PEP 205 <1>: weakref — Weak references.
                                                             (line  353)
* Python Enhancement Proposals; PEP 207: PEP 207 Rich Comparisons.
                                                             (line   71)
* Python Enhancement Proposals; PEP 207 <1>: PEP 207 Rich Comparisons.
                                                             (line   77)
* Python Enhancement Proposals; PEP 208: PEP 208 New Coercion Model.
                                                             (line   30)
* Python Enhancement Proposals; PEP 217: PEP 217 Interactive Display Hook.
                                                             (line   27)
* Python Enhancement Proposals; PEP 218: PEP 218 Built-In Set Objects.
                                                             (line   50)
* Python Enhancement Proposals; PEP 218 <1>: Other Language Changes<16>.
                                                             (line   12)
* Python Enhancement Proposals; PEP 218 <2>: PEP 218 A Standard Set Datatype.
                                                             (line   81)
* Python Enhancement Proposals; PEP 227: PEP 227 Nested Scopes.
                                                             (line   96)
* Python Enhancement Proposals; PEP 227 <1>: PEP 227 Nested Scopes<2>.
                                                             (line   96)
* Python Enhancement Proposals; PEP 227 <2>: Module Contents<5>.
                                                             (line   14)
* Python Enhancement Proposals; PEP 229: PEP 229 New Build System.
                                                             (line   39)
* Python Enhancement Proposals; PEP 230: PEP 230 Warning Framework.
                                                             (line   73)
* Python Enhancement Proposals; PEP 232: PEP 232 Function Attributes.
                                                             (line   36)
* Python Enhancement Proposals; PEP 234: PEP 234 Iterators.  (line  124)
* Python Enhancement Proposals; PEP 235: Introduction<12>.   (line   51)
* Python Enhancement Proposals; PEP 236: PEP 227 Nested Scopes<2>.
                                                             (line   87)
* Python Enhancement Proposals; PEP 236 <1>: PEP 227 Nested Scopes<2>.
                                                             (line   88)
* Python Enhancement Proposals; PEP 236 <2>: PEP 236 __future__ Directives.
                                                             (line   29)
* Python Enhancement Proposals; PEP 236 <3>: Future statements.
                                                             (line   85)
* Python Enhancement Proposals; PEP 236 <4>: Module Contents<5>.
                                                             (line  106)
* Python Enhancement Proposals; PEP 237: Integers.           (line    6)
* Python Enhancement Proposals; PEP 237 <1>: PEP 237 Unifying Long Integers and Integers.
                                                             (line   22)
* Python Enhancement Proposals; PEP 237 <2>: Other Language Changes<16>.
                                                             (line   18)
* Python Enhancement Proposals; PEP 237 <3>: PEP 237 Unifying Long Integers and Integers<2>.
                                                             (line   37)
* Python Enhancement Proposals; PEP 237 <4>: Formattazione delle stringhe in stile printf.
                                                             (line  189)
* Python Enhancement Proposals; PEP 237 <5>: Formattazione Bytes stile printf.
                                                             (line  191)
* Python Enhancement Proposals; PEP 238: Integers.           (line   10)
* Python Enhancement Proposals; PEP 238 <1>: PEP 238 Changing the Division Operator.
                                                             (line   21)
* Python Enhancement Proposals; PEP 238 <2>: PEP 238 Changing the Division Operator.
                                                             (line   27)
* Python Enhancement Proposals; PEP 238 <3>: PEP 238 Changing the Division Operator.
                                                             (line   68)
* Python Enhancement Proposals; PEP 238 <4>: Module Contents<5>.
                                                             (line   22)
* Python Enhancement Proposals; PEP 238 <5>: Glossary.       (line  654)
* Python Enhancement Proposals; PEP 241: PEP 241 Metadata in Python Packages.
                                                             (line   16)
* Python Enhancement Proposals; PEP 241 <1>: PEP 241 Metadata in Python Packages.
                                                             (line   29)
* Python Enhancement Proposals; PEP 241 <2>: PEP 241 Metadata in Python Packages.
                                                             (line   36)
* Python Enhancement Proposals; PEP 243: PEP 241 Metadata in Python Packages.
                                                             (line   40)
* Python Enhancement Proposals; PEP 246: Documentation<27>.  (line   48)
* Python Enhancement Proposals; PEP 246 <1>: PrepareProtocol objects.
                                                             (line    8)
* Python Enhancement Proposals; PEP 247: hmac<4>.            (line   20)
* Python Enhancement Proposals; PEP 249: sqlite3<3>.         (line   11)
* Python Enhancement Proposals; PEP 249 <1>: The sqlite3 package.
                                                             (line   18)
* Python Enhancement Proposals; PEP 249 <2>: The sqlite3 package.
                                                             (line  110)
* Python Enhancement Proposals; PEP 249 <3>: Library<76>.    (line  124)
* Python Enhancement Proposals; PEP 249 <4>: Library<91>.    (line  296)
* Python Enhancement Proposals; PEP 249 <5>: sqlite3 — DB-API 2 0 interface for SQLite databases.
                                                             (line   16)
* Python Enhancement Proposals; PEP 249 <6>: sqlite3 — DB-API 2 0 interface for SQLite databases.
                                                             (line   48)
* Python Enhancement Proposals; PEP 249 <7>: Module functions.
                                                             (line   72)
* Python Enhancement Proposals; PEP 249 <8>: Connection objects.
                                                             (line  735)
* Python Enhancement Proposals; PEP 249 <9>: Connection objects.
                                                             (line  738)
* Python Enhancement Proposals; PEP 249 <10>: Connection objects.
                                                             (line  750)
* Python Enhancement Proposals; PEP 249 <11>: Exceptions<6>. (line    6)
* Python Enhancement Proposals; PEP 249 <12>: How to use placeholders to bind values in SQL queries.
                                                             (line   53)
* Python Enhancement Proposals; PEP 249 <13>: Transaction control via the autocommit attribute.
                                                             (line   10)
* Python Enhancement Proposals; PEP 249 <14>: Transaction control via the autocommit attribute.
                                                             (line   30)
* Python Enhancement Proposals; PEP 252: Related Links.      (line   17)
* Python Enhancement Proposals; PEP 252 <1>: Related Links.  (line   17)
* Python Enhancement Proposals; PEP 252 <2>: Implementing Descriptors.
                                                             (line   26)
* Python Enhancement Proposals; PEP 253: Old and New Classes.
                                                             (line   28)
* Python Enhancement Proposals; PEP 253 <1>: Multiple Inheritance The Diamond Rule.
                                                             (line    8)
* Python Enhancement Proposals; PEP 253 <2>: Related Links.  (line   17)
* Python Enhancement Proposals; PEP 253 <3>: Related Links.  (line   19)
* Python Enhancement Proposals; PEP 253 <4>: Related Links.  (line   21)
* Python Enhancement Proposals; PEP 255: PEP 255 Simple Generators.
                                                             (line   45)
* Python Enhancement Proposals; PEP 255 <1>: PEP 255 Simple Generators.
                                                             (line  131)
* Python Enhancement Proposals; PEP 255 <2>: PEP 255 Simple Generators<2>.
                                                             (line   43)
* Python Enhancement Proposals; PEP 255 <3>: PEP 255 Simple Generators<2>.
                                                             (line  129)
* Python Enhancement Proposals; PEP 255 <4>: Yield expressions.
                                                             (line   90)
* Python Enhancement Proposals; PEP 255 <5>: Module Contents<5>.
                                                             (line   18)
* Python Enhancement Proposals; PEP 261: Unicode Changes.    (line   18)
* Python Enhancement Proposals; PEP 261 <1>: Unicode Changes.
                                                             (line   61)
* Python Enhancement Proposals; PEP 263: Other Language Changes<15>.
                                                             (line   99)
* Python Enhancement Proposals; PEP 263 <1>: PEP 263 Source Code Encodings.
                                                             (line   29)
* Python Enhancement Proposals; PEP 263 <2>: Core and Builtins<101>.
                                                             (line   30)
* Python Enhancement Proposals; PEP 263 <3>: Introduction<12>.
                                                             (line   55)
* Python Enhancement Proposals; PEP 263 <4>: Tokenizing Input.
                                                             (line   35)
* Python Enhancement Proposals; PEP 263 <5>: Tokenizing Input.
                                                             (line   88)
* Python Enhancement Proposals; PEP 263 <6>: Unicode Literals in Python Source Code.
                                                             (line   48)
* Python Enhancement Proposals; PEP 264: Other Changes and Fixes<3>.
                                                             (line   55)
* Python Enhancement Proposals; PEP 273: PEP 273 Importing Modules from ZIP Archives.
                                                             (line   41)
* Python Enhancement Proposals; PEP 273 <1>: PEP 273 Importing Modules from ZIP Archives.
                                                             (line   44)
* Python Enhancement Proposals; PEP 273 <2>: zipimport — Import modules from Zip archives.
                                                             (line   44)
* Python Enhancement Proposals; PEP 273 <3>: zipimport — Import modules from Zip archives.
                                                             (line   47)
* Python Enhancement Proposals; PEP 274: New Syntax.         (line   39)
* Python Enhancement Proposals; PEP 277: PEP 277 Unicode file name support for Windows NT.
                                                             (line   32)
* Python Enhancement Proposals; PEP 278: PEP 278 Universal Newline Support.
                                                             (line   33)
* Python Enhancement Proposals; PEP 278 <1>: Glossary.       (line 1821)
* Python Enhancement Proposals; PEP 279: PEP 279 enumerate.  (line   27)
* Python Enhancement Proposals; PEP 282: PEP 282 The logging Package.
                                                             (line  105)
* Python Enhancement Proposals; PEP 282 <1>: PEP 282 The logging Package.
                                                             (line  111)
* Python Enhancement Proposals; PEP 282 <2>: Archiving operations.
                                                             (line   48)
* Python Enhancement Proposals; PEP 282 <3>: Integration with the warnings module.
                                                             (line   36)
* Python Enhancement Proposals; PEP 285: PEP 285 A Boolean Type.
                                                             (line   47)
* Python Enhancement Proposals; PEP 285 <1>: PEP 285 A Boolean Type.
                                                             (line   70)
* Python Enhancement Proposals; PEP 288: PEP 342 New Generator Features.
                                                             (line  146)
* Python Enhancement Proposals; PEP 289: PEP 289 Generator Expressions.
                                                             (line   55)
* Python Enhancement Proposals; PEP 289 <1>: Other Language Changes<16>.
                                                             (line   15)
* Python Enhancement Proposals; PEP 289 <2>: Python documentation.
                                                             (line   12)
* Python Enhancement Proposals; PEP 292: PEP 292 Simpler String Substitutions.
                                                             (line   45)
* Python Enhancement Proposals; PEP 292 <1>: Template strings $-strings.
                                                             (line   16)
* Python Enhancement Proposals; PEP 293: PEP 293 Codec Error Handling Callbacks.
                                                             (line   33)
* Python Enhancement Proposals; PEP 3000: Python 3 0.        (line   43)
* Python Enhancement Proposals; PEP 301: PEP 301 Package Index and Metadata for Distutils.
                                                             (line   45)
* Python Enhancement Proposals; PEP 302: Using importlib as the Implementation of Import.
                                                             (line   13)
* Python Enhancement Proposals; PEP 302 <1>: Visible Changes.
                                                             (line   18)
* Python Enhancement Proposals; PEP 302 <2>: Porting Python code.
                                                             (line   71)
* Python Enhancement Proposals; PEP 302 <3>: New Improved and Deprecated Modules<2>.
                                                             (line  106)
* Python Enhancement Proposals; PEP 302 <4>: New Improved and Removed Modules.
                                                             (line  289)
* Python Enhancement Proposals; PEP 302 <5>: PEP 273 Importing Modules from ZIP Archives.
                                                             (line   46)
* Python Enhancement Proposals; PEP 302 <6>: PEP 302 New Import Hooks.
                                                             (line   13)
* Python Enhancement Proposals; PEP 302 <7>: PEP 302 New Import Hooks.
                                                             (line   38)
* Python Enhancement Proposals; PEP 302 <8>: PEP 302 New Import Hooks.
                                                             (line   62)
* Python Enhancement Proposals; PEP 302 <9>: The import system.
                                                             (line   42)
* Python Enhancement Proposals; PEP 302 <10>: References.    (line   10)
* Python Enhancement Proposals; PEP 302 <11>: Funzioni Incorporate.
                                                             (line 2298)
* Python Enhancement Proposals; PEP 302 <12>: linecache — Random access to text lines.
                                                             (line   35)
* Python Enhancement Proposals; PEP 302 <13>: sys — System-specific parameters and functions.
                                                             (line 1490)
* Python Enhancement Proposals; PEP 302 <14>: sys — System-specific parameters and functions.
                                                             (line 1500)
* Python Enhancement Proposals; PEP 302 <15>: zipimport — Import modules from Zip archives.
                                                             (line   49)
* Python Enhancement Proposals; PEP 302 <16>: pkgutil — Package extension utility.
                                                             (line   66)
* Python Enhancement Proposals; PEP 302 <17>: pkgutil — Package extension utility.
                                                             (line   84)
* Python Enhancement Proposals; PEP 302 <18>: pkgutil — Package extension utility.
                                                             (line  105)
* Python Enhancement Proposals; PEP 302 <19>: pkgutil — Package extension utility.
                                                             (line  144)
* Python Enhancement Proposals; PEP 302 <20>: runpy — Locating and executing Python modules.
                                                             (line   32)
* Python Enhancement Proposals; PEP 302 <21>: Introduction<12>.
                                                             (line   59)
* Python Enhancement Proposals; PEP 302 <22>: importlib abc – Abstract base classes related to import.
                                                             (line   93)
* Python Enhancement Proposals; PEP 302 <23>: importlib abc – Abstract base classes related to import.
                                                             (line  180)
* Python Enhancement Proposals; PEP 302 <24>: importlib abc – Abstract base classes related to import.
                                                             (line  207)
* Python Enhancement Proposals; PEP 302 <25>: importlib abc – Abstract base classes related to import.
                                                             (line  279)
* Python Enhancement Proposals; PEP 302 <26>: Glossary.      (line 1064)
* Python Enhancement Proposals; PEP 305: PEP 305 Comma-separated Files.
                                                             (line   42)
* Python Enhancement Proposals; PEP 305 <1>: csv — CSV File Reading and Writing.
                                                             (line   38)
* Python Enhancement Proposals; PEP 307: PEP 307 Pickle Enhancements.
                                                             (line    8)
* Python Enhancement Proposals; PEP 307 <1>: PEP 307 Pickle Enhancements.
                                                             (line   30)
* Python Enhancement Proposals; PEP 307 <2>: PEP 307 Pickle Enhancements.
                                                             (line   42)
* Python Enhancement Proposals; PEP 307 <3>: Data stream format.
                                                             (line   32)
* Python Enhancement Proposals; PEP 308: PEP 308 Conditional Expressions.
                                                             (line   72)
* Python Enhancement Proposals; PEP 308 <1>: PEP 308 Conditional Expressions.
                                                             (line   78)
* Python Enhancement Proposals; PEP 308 <2>: Conditional expressions.
                                                             (line   17)
* Python Enhancement Proposals; PEP 309: PEP 309 Partial Function Application.
                                                             (line   73)
* Python Enhancement Proposals; PEP 3100: Python 3 0.        (line   44)
* Python Enhancement Proposals; PEP 3101: PEP 3101 A New Approach To String Formatting.
                                                             (line    3)
* Python Enhancement Proposals; PEP 3101 <1>: PEP 3101 A New Approach To String Formatting.
                                                             (line    8)
* Python Enhancement Proposals; PEP 3101 <2>: PEP 3101 Advanced String Formatting.
                                                             (line  162)
* Python Enhancement Proposals; PEP 3101 <3>: Custom String Formatting.
                                                             (line    8)
* Python Enhancement Proposals; PEP 3101 <4>: Custom String Formatting.
                                                             (line   63)
* Python Enhancement Proposals; PEP 3102: New Syntax.        (line   14)
* Python Enhancement Proposals; PEP 3104: New Syntax.        (line   25)
* Python Enhancement Proposals; PEP 3104 <1>: The nonlocal statement.
                                                             (line   25)
* Python Enhancement Proposals; PEP 3105: Print Is A Function.
                                                             (line    8)
* Python Enhancement Proposals; PEP 3105 <1>: PEP 3105 print As a Function.
                                                             (line   35)
* Python Enhancement Proposals; PEP 3105 <2>: Module Contents<5>.
                                                             (line   35)
* Python Enhancement Proposals; PEP 3106: PEP 3106 Dictionary Views.
                                                             (line   58)
* Python Enhancement Proposals; PEP 3107: PEP 563 Postponed Evaluation of Annotations.
                                                             (line    7)
* Python Enhancement Proposals; PEP 3107 <1>: PEP 484 - Type Hints.
                                                             (line    7)
* Python Enhancement Proposals; PEP 3107 <2>: New Syntax.    (line    6)
* Python Enhancement Proposals; PEP 3107 <3>: Annotationi delle Funzioni.
                                                             (line    8)
* Python Enhancement Proposals; PEP 3107 <4>: Function definitions.
                                                             (line  143)
* Python Enhancement Proposals; PEP 3107 <5>: Annotation semantics.
                                                             (line   10)
* Python Enhancement Proposals; PEP 3107 <6>: Annotation semantics.
                                                             (line   45)
* Python Enhancement Proposals; PEP 3108: Library Changes.   (line    7)
* Python Enhancement Proposals; PEP 3108 <1>: Library Changes.
                                                             (line   17)
* Python Enhancement Proposals; PEP 3108 <2>: Library Changes.
                                                             (line   95)
* Python Enhancement Proposals; PEP 3109: Changed Syntax.    (line    6)
* Python Enhancement Proposals; PEP 3109 <1>: Changes To Exceptions.
                                                             (line   29)
* Python Enhancement Proposals; PEP 3110: Changed Syntax.    (line   16)
* Python Enhancement Proposals; PEP 3110 <1>: Changes To Exceptions.
                                                             (line   35)
* Python Enhancement Proposals; PEP 3110 <2>: PEP 3110 Exception-Handling Changes.
                                                             (line   48)
* Python Enhancement Proposals; PEP 3111: Builtins.          (line   12)
* Python Enhancement Proposals; PEP 3112: PEP 3112 Byte Literals.
                                                             (line   76)
* Python Enhancement Proposals; PEP 3112 <1>: Module Contents<5>.
                                                             (line   39)
* Python Enhancement Proposals; PEP 3113: Removed Syntax.    (line    6)
* Python Enhancement Proposals; PEP 3114: Operators And Special Methods.
                                                             (line   19)
* Python Enhancement Proposals; PEP 3115: types<8>.          (line   10)
* Python Enhancement Proposals; PEP 3115 <1>: Changed Syntax.
                                                             (line   18)
* Python Enhancement Proposals; PEP 3115 <2>: Preparing the class namespace.
                                                             (line   21)
* Python Enhancement Proposals; PEP 3115 <3>: Class definitions.
                                                             (line   84)
* Python Enhancement Proposals; PEP 3115 <4>: Dynamic Type Creation.
                                                             (line   54)
* Python Enhancement Proposals; PEP 3115 <5>: Function and class definitions.
                                                             (line  181)
* Python Enhancement Proposals; PEP 3116: Optimizations<12>. (line    8)
* Python Enhancement Proposals; PEP 3116 <1>: PEP 3116 New I/O Library.
                                                             (line   73)
* Python Enhancement Proposals; PEP 3116 <2>: Glossary.      (line 1821)
* Python Enhancement Proposals; PEP 3118: Pickle protocol 5 with out-of-band data buffers.
                                                             (line   13)
* Python Enhancement Proposals; PEP 3118 <1>: PEP 3118 New memoryview implementation and buffer protocol documentation.
                                                             (line    6)
* Python Enhancement Proposals; PEP 3118 <2>: API changes.   (line   29)
* Python Enhancement Proposals; PEP 3118 <3>: Build and C API Changes<4>.
                                                             (line    8)
* Python Enhancement Proposals; PEP 3118 <4>: Build and C API Changes<7>.
                                                             (line   12)
* Python Enhancement Proposals; PEP 3118 <5>: PEP 3118 Revised Buffer Protocol.
                                                             (line   46)
* Python Enhancement Proposals; PEP 3118 <6>: Library<172>.  (line   99)
* Python Enhancement Proposals; PEP 3118 <7>: Library<177>.  (line   61)
* Python Enhancement Proposals; PEP 3118 <8>: Library<206>.  (line  958)
* Python Enhancement Proposals; PEP 3118 <9>: Memory Views.  (line  124)
* Python Enhancement Proposals; PEP 3118 <10>: Module Interface.
                                                             (line   27)
* Python Enhancement Proposals; PEP 3119: PEP 3119 Abstract Base Classes.
                                                             (line  138)
* Python Enhancement Proposals; PEP 3119 <1>: Customizing instance and subclass checks.
                                                             (line   35)
* Python Enhancement Proposals; PEP 3119 <2>: Examples and Recipes.
                                                             (line   73)
* Python Enhancement Proposals; PEP 3119 <3>: abc — Abstract Base Classes.
                                                             (line   11)
* Python Enhancement Proposals; PEP 3119 <4>: Object Protocol.
                                                             (line  387)
* Python Enhancement Proposals; PEP 3119 <5>: Object Protocol.
                                                             (line  407)
* Python Enhancement Proposals; PEP 3120: Text Vs Data Instead Of Unicode Vs 8-bit.
                                                             (line  107)
* Python Enhancement Proposals; PEP 3120 <1>: Introduction<12>.
                                                             (line   91)
* Python Enhancement Proposals; PEP 3121: Build and C API Changes<7>.
                                                             (line   14)
* Python Enhancement Proposals; PEP 3121 <1>: Library<146>.  (line    6)
* Python Enhancement Proposals; PEP 3121 <2>: Module definitions.
                                                             (line   65)
* Python Enhancement Proposals; PEP 3123: Build and C API Changes<7>.
                                                             (line   16)
* Python Enhancement Proposals; PEP 3127: PEP 3127 Integer Literal Support and Syntax.
                                                             (line   47)
* Python Enhancement Proposals; PEP 3129: PEP 3129 Class Decorators.
                                                             (line   24)
* Python Enhancement Proposals; PEP 3129 <1>: Function definitions.
                                                             (line  165)
* Python Enhancement Proposals; PEP 3129 <2>: Class definitions.
                                                             (line   90)
* Python Enhancement Proposals; PEP 3131: Text Vs Data Instead Of Unicode Vs 8-bit.
                                                             (line  109)
* Python Enhancement Proposals; PEP 3131 <1>: Library<161>.  (line  600)
* Python Enhancement Proposals; PEP 3131 <2>: Non-ASCII characters in names.
                                                             (line   91)
* Python Enhancement Proposals; PEP 3132: New Syntax.        (line   29)
* Python Enhancement Proposals; PEP 3132 <1>: Assignment statements.
                                                             (line  158)
* Python Enhancement Proposals; PEP 3134: Changed Syntax.    (line    6)
* Python Enhancement Proposals; PEP 3134 <1>: Changes To Exceptions.
                                                             (line   40)
* Python Enhancement Proposals; PEP 3134 <2>: Changes To Exceptions.
                                                             (line   61)
* Python Enhancement Proposals; PEP 3134 <3>: Library<91>.   (line   48)
* Python Enhancement Proposals; PEP 3134 <4>: Base classes.  (line   29)
* Python Enhancement Proposals; PEP 3135: Builtins.          (line    6)
* Python Enhancement Proposals; PEP 3135 <1>: Creating the class object.
                                                             (line   53)
* Python Enhancement Proposals; PEP 3137: PEP 3137 The memoryview Object.
                                                             (line   49)
* Python Enhancement Proposals; PEP 3138: Text Vs Data Instead Of Unicode Vs 8-bit.
                                                             (line  103)
* Python Enhancement Proposals; PEP 314: PEP 314 Metadata for Python Software Packages v1 1.
                                                             (line   42)
* Python Enhancement Proposals; PEP 3141: PEP 3141 A Type Hierarchy for Numbers.
                                                             (line   43)
* Python Enhancement Proposals; PEP 3141 <1>: numbers — Numeric abstract base classes.
                                                             (line   10)
* Python Enhancement Proposals; PEP 3141 <2>: abc — Abstract Base Classes.
                                                             (line   12)
* Python Enhancement Proposals; PEP 3144: ipaddress<6>.      (line   10)
* Python Enhancement Proposals; PEP 3147: PEP 421 Adding sys implementation.
                                                             (line   21)
* Python Enhancement Proposals; PEP 3147 <1>: PEP 3147 PYC Repository Directories.
                                                             (line   69)
* Python Enhancement Proposals; PEP 3147 <2>: File Python «compilati».
                                                             (line   49)
* Python Enhancement Proposals; PEP 3147 <3>: Import-related attributes on module objects.
                                                             (line  156)
* Python Enhancement Proposals; PEP 3147 <4>: test support import_helper — Utilities for import tests.
                                                             (line   82)
* Python Enhancement Proposals; PEP 3147 <5>: runpy — Locating and executing Python modules.
                                                             (line   87)
* Python Enhancement Proposals; PEP 3147 <6>: Introduction<12>.
                                                             (line   95)
* Python Enhancement Proposals; PEP 3147 <7>: importlib util – Utility code for importers.
                                                             (line   24)
* Python Enhancement Proposals; PEP 3147 <8>: importlib util – Utility code for importers.
                                                             (line   60)
* Python Enhancement Proposals; PEP 3147 <9>: importlib util – Utility code for importers.
                                                             (line   64)
* Python Enhancement Proposals; PEP 3147 <10>: py_compile — Compile Python source files.
                                                             (line   30)
* Python Enhancement Proposals; PEP 3147 <11>: py_compile — Compile Python source files.
                                                             (line   71)
* Python Enhancement Proposals; PEP 3147 <12>: Command-line use.
                                                             (line   70)
* Python Enhancement Proposals; PEP 3147 <13>: Public functions.
                                                             (line   40)
* Python Enhancement Proposals; PEP 3147 <14>: Public functions.
                                                             (line  122)
* Python Enhancement Proposals; PEP 3147 <15>: Importing Modules<2>.
                                                             (line  221)
* Python Enhancement Proposals; PEP 3147 <16>: How do I create a pyc file?.
                                                             (line   12)
* Python Enhancement Proposals; PEP 3148: PEP 3148 The concurrent futures module.
                                                             (line   51)
* Python Enhancement Proposals; PEP 3148 <1>: Module Functions.
                                                             (line   61)
* Python Enhancement Proposals; PEP 3149: PEP 3149 ABI Version Tagged so Files.
                                                             (line   33)
* Python Enhancement Proposals; PEP 3149 <1>: Core and Builtins<200>.
                                                             (line    9)
* Python Enhancement Proposals; PEP 3149 <2>: sys — System-specific parameters and functions.
                                                             (line   16)
* Python Enhancement Proposals; PEP 3151: PEP 3151 Reworking the OS and IO exception hierarchy.
                                                             (line   85)
* Python Enhancement Proposals; PEP 3151 <1>: OS exceptions. (line  123)
* Python Enhancement Proposals; PEP 3151 <2>: Exceptions<17>.
                                                             (line   10)
* Python Enhancement Proposals; PEP 3151 <3>: select — Waiting for I/O completion.
                                                             (line   33)
* Python Enhancement Proposals; PEP 3151 <4>: resource — Resource usage information.
                                                             (line   23)
* Python Enhancement Proposals; PEP 3151 <5>: Exception types.
                                                             (line  255)
* Python Enhancement Proposals; PEP 3154: Summary – Release Highlights<3>.
                                                             (line   57)
* Python Enhancement Proposals; PEP 3154 <1>: pickle<5>.     (line   16)
* Python Enhancement Proposals; PEP 3154 <2>: Library<161>.  (line 1280)
* Python Enhancement Proposals; PEP 3154 <3>: Data stream format.
                                                             (line   42)
* Python Enhancement Proposals; PEP 3155: PEP 3155 Qualified name for classes and functions.
                                                             (line   63)
* Python Enhancement Proposals; PEP 3155 <1>: Glossary.      (line 1471)
* Python Enhancement Proposals; PEP 3156: Summary – Release Highlights<3>.
                                                             (line   31)
* Python Enhancement Proposals; PEP 3156 <1>: Summary – Release Highlights<3>.
                                                             (line   44)
* Python Enhancement Proposals; PEP 3156 <2>: asyncio<14>.   (line    6)
* Python Enhancement Proposals; PEP 3156 <3>: asyncio<14>.   (line   17)
* Python Enhancement Proposals; PEP 3156 <4>: selectors<2>.  (line    6)
* Python Enhancement Proposals; PEP 318: PEP 318 Decorators for Functions and Methods.
                                                             (line  101)
* Python Enhancement Proposals; PEP 318 <1>: PEP 318 Decorators for Functions and Methods.
                                                             (line  125)
* Python Enhancement Proposals; PEP 318 <2>: Other Language Changes<16>.
                                                             (line    9)
* Python Enhancement Proposals; PEP 318 <3>: Function definitions.
                                                             (line  162)
* Python Enhancement Proposals; PEP 318 <4>: Class definitions.
                                                             (line   93)
* Python Enhancement Proposals; PEP 322: PEP 322 Reverse Iteration.
                                                             (line   35)
* Python Enhancement Proposals; PEP 322 <1>: Other Language Changes<16>.
                                                             (line   13)
* Python Enhancement Proposals; PEP 324: PEP 324 New subprocess Module.
                                                             (line   86)
* Python Enhancement Proposals; PEP 324 <1>: subprocess — Subprocess management.
                                                             (line   25)
* Python Enhancement Proposals; PEP 325: PEP 342 New Generator Features.
                                                             (line  147)
* Python Enhancement Proposals; PEP 327: The Context type.   (line   56)
* Python Enhancement Proposals; PEP 328: Porting Python code.
                                                             (line   36)
* Python Enhancement Proposals; PEP 328 <1>: Removed Syntax. (line   29)
* Python Enhancement Proposals; PEP 328 <2>: PEP 328 Absolute and Relative Imports.
                                                             (line    6)
* Python Enhancement Proposals; PEP 328 <3>: PEP 328 Absolute and Relative Imports.
                                                             (line   82)
* Python Enhancement Proposals; PEP 328 <4>: PEP 328 Multi-line Imports.
                                                             (line   35)
* Python Enhancement Proposals; PEP 328 <5>: Other Language Changes<16>.
                                                             (line   21)
* Python Enhancement Proposals; PEP 328 <6>: References.     (line   20)
* Python Enhancement Proposals; PEP 328 <7>: Funzioni Incorporate.
                                                             (line 2317)
* Python Enhancement Proposals; PEP 328 <8>: Module Contents<5>.
                                                             (line   26)
* Python Enhancement Proposals; PEP 328 <9>: Introduction<12>.
                                                             (line   63)
* Python Enhancement Proposals; PEP 331: PEP 331 Locale-Independent Float/String Conversions.
                                                             (line   38)
* Python Enhancement Proposals; PEP 333: The wsgiref package.
                                                             (line    8)
* Python Enhancement Proposals; PEP 333 <1>: The wsgiref package.
                                                             (line   31)
* Python Enhancement Proposals; PEP 3333: New Modules<2>.    (line    9)
* Python Enhancement Proposals; PEP 3333 <1>: PEP 3333 Python Web Server Gateway Interface v1 0 1.
                                                             (line   50)
* Python Enhancement Proposals; PEP 3333 <2>: wsgiref — WSGI Utilities and Reference Implementation.
                                                             (line   26)
* Python Enhancement Proposals; PEP 3333 <3>: wsgiref util – WSGI environment utilities.
                                                             (line    8)
* Python Enhancement Proposals; PEP 3333 <4>: wsgiref util – WSGI environment utilities.
                                                             (line   10)
* Python Enhancement Proposals; PEP 3333 <5>: wsgiref util – WSGI environment utilities.
                                                             (line   30)
* Python Enhancement Proposals; PEP 3333 <6>: wsgiref util – WSGI environment utilities.
                                                             (line   76)
* Python Enhancement Proposals; PEP 3333 <7>: wsgiref headers – WSGI response header tools.
                                                             (line   12)
* Python Enhancement Proposals; PEP 3333 <8>: wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line   21)
* Python Enhancement Proposals; PEP 3333 <9>: wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line   99)
* Python Enhancement Proposals; PEP 3333 <10>: wsgiref validate — WSGI conformance checker.
                                                             (line   13)
* Python Enhancement Proposals; PEP 3333 <11>: wsgiref validate — WSGI conformance checker.
                                                             (line   40)
* Python Enhancement Proposals; PEP 3333 <12>: wsgiref handlers – server/gateway base classes.
                                                             (line  238)
* Python Enhancement Proposals; PEP 3333 <13>: wsgiref handlers – server/gateway base classes.
                                                             (line  256)
* Python Enhancement Proposals; PEP 3333 <14>: wsgiref handlers – server/gateway base classes.
                                                             (line  263)
* Python Enhancement Proposals; PEP 3333 <15>: wsgiref handlers – server/gateway base classes.
                                                             (line  272)
* Python Enhancement Proposals; PEP 3333 <16>: wsgiref handlers – server/gateway base classes.
                                                             (line  315)
* Python Enhancement Proposals; PEP 3333 <17>: wsgiref types – WSGI types for static type checking.
                                                             (line    7)
* Python Enhancement Proposals; PEP 3333 <18>: wsgiref types – WSGI types for static type checking.
                                                             (line   14)
* Python Enhancement Proposals; PEP 3333#input-and-error-streams: wsgiref types – WSGI types for static type checking.
                                                             (line   26)
* Python Enhancement Proposals; PEP 3333#input-and-error-streams <1>: wsgiref types – WSGI types for static type checking.
                                                             (line   30)
* Python Enhancement Proposals; PEP 3333#optional-platform-specific-file-handling: wsgiref types – WSGI types for static type checking.
                                                             (line   34)
* Python Enhancement Proposals; PEP 3333#the-start-response-callable: wsgiref types – WSGI types for static type checking.
                                                             (line   13)
* Python Enhancement Proposals; PEP 338: PEP 338 Executing Modules as Scripts.
                                                             (line   21)
* Python Enhancement Proposals; PEP 338 <1>: Interface options.
                                                             (line  103)
* Python Enhancement Proposals; PEP 338 <2>: References.     (line   24)
* Python Enhancement Proposals; PEP 338 <3>: runpy — Locating and executing Python modules.
                                                             (line  178)
* Python Enhancement Proposals; PEP 339: Build and C API Changes<10>.
                                                             (line   46)
* Python Enhancement Proposals; PEP 341: PEP 341 Unified try/except/finally.
                                                             (line   44)
* Python Enhancement Proposals; PEP 342: PEP 342 New Generator Features.
                                                             (line   42)
* Python Enhancement Proposals; PEP 342 <1>: PEP 342 New Generator Features.
                                                             (line  140)
* Python Enhancement Proposals; PEP 342 <2>: Porting to Python 2 5.
                                                             (line   15)
* Python Enhancement Proposals; PEP 342 <3>: Yield expressions.
                                                             (line   95)
* Python Enhancement Proposals; PEP 342 <4>: Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   59)
* Python Enhancement Proposals; PEP 342 <5>: Passing values into a generator.
                                                             (line   25)
* Python Enhancement Proposals; PEP 342 <6>: Python documentation.
                                                             (line   14)
* Python Enhancement Proposals; PEP 343: The contextlib module.
                                                             (line   64)
* Python Enhancement Proposals; PEP 343 <1>: PEP 342 New Generator Features.
                                                             (line  129)
* Python Enhancement Proposals; PEP 343 <2>: The contextlib module<2>.
                                                             (line   64)
* Python Enhancement Proposals; PEP 343 <3>: With Statement Context Managers.
                                                             (line   46)
* Python Enhancement Proposals; PEP 343 <4>: The with statement.
                                                             (line  111)
* Python Enhancement Proposals; PEP 343 <5>: Using a context manager as a function decorator.
                                                             (line   51)
* Python Enhancement Proposals; PEP 343 <6>: Module Contents<5>.
                                                             (line   31)
* Python Enhancement Proposals; PEP 343 <7>: Glossary.       (line  372)
* Python Enhancement Proposals; PEP 343 <8>: Glossary.       (line  378)
* Python Enhancement Proposals; PEP 347: Build and C API Changes<10>.
                                                             (line   10)
* Python Enhancement Proposals; PEP 352: Changes To Exceptions.
                                                             (line    9)
* Python Enhancement Proposals; PEP 352 <1>: Deprecations and Removals.
                                                             (line    9)
* Python Enhancement Proposals; PEP 352 <2>: PEP 352 Exceptions as New-Style Classes.
                                                             (line   58)
* Python Enhancement Proposals; PEP 353: Porting to Python 3 10<2>.
                                                             (line    9)
* Python Enhancement Proposals; PEP 353 <1>: PEP 353 Using ssize_t as the index type.
                                                             (line   49)
* Python Enhancement Proposals; PEP 353 <2>: PEP 353 Using ssize_t as the index type.
                                                             (line   55)
* Python Enhancement Proposals; PEP 353 <3>: Build and C API Changes<10>.
                                                             (line   20)
* Python Enhancement Proposals; PEP 353 <4>: C API<45>.      (line   80)
* Python Enhancement Proposals; PEP 353 <5>: Types<2>.       (line   17)
* Python Enhancement Proposals; PEP 356: What’s New in Python 2 5.
                                                             (line   10)
* Python Enhancement Proposals; PEP 357: PEP 357 The “__index__” method.
                                                             (line   39)
* Python Enhancement Proposals; PEP 361: What’s New in Python 2 6.
                                                             (line   10)
* Python Enhancement Proposals; PEP 362: PEP 362 Function Signature Object.
                                                             (line   19)
* Python Enhancement Proposals; PEP 362 <1>: Introspecting callables with the Signature object.
                                                             (line  418)
* Python Enhancement Proposals; PEP 362 <2>: Glossary.       (line   93)
* Python Enhancement Proposals; PEP 362 <3>: Glossary.       (line 1355)
* Python Enhancement Proposals; PEP 366: Visible Changes.    (line   24)
* Python Enhancement Proposals; PEP 366 <1>: Import-related attributes on module objects.
                                                             (line   63)
* Python Enhancement Proposals; PEP 366 <2>: References.     (line   17)
* Python Enhancement Proposals; PEP 366 <3>: References.     (line   21)
* Python Enhancement Proposals; PEP 366 <4>: runpy — Locating and executing Python modules.
                                                             (line  182)
* Python Enhancement Proposals; PEP 366 <5>: Introduction<12>.
                                                             (line   67)
* Python Enhancement Proposals; PEP 370: PEP 370 Per-user site-packages Directory.
                                                             (line   36)
* Python Enhancement Proposals; PEP 370 <1>: Library<86>.    (line  603)
* Python Enhancement Proposals; PEP 370 <2>: Miscellaneous options.
                                                             (line  164)
* Python Enhancement Proposals; PEP 370 <3>: Environment variables.
                                                             (line  205)
* Python Enhancement Proposals; PEP 370 <4>: Environment variables.
                                                             (line  217)
* Python Enhancement Proposals; PEP 370 <5>: Command-line interface<11>.
                                                             (line   37)
* Python Enhancement Proposals; PEP 371: PEP 371 The multiprocessing Package.
                                                             (line  147)
* Python Enhancement Proposals; PEP 372: PEP 372 Ordered Dictionaries.
                                                             (line   31)
* Python Enhancement Proposals; PEP 372 <1>: PEP 372 Adding an Ordered Dictionary to collections.
                                                             (line   97)
* Python Enhancement Proposals; PEP 373: The Future for Python 2 x.
                                                             (line   23)
* Python Enhancement Proposals; PEP 373 <1>: How stable is Python?.
                                                             (line   20)
* Python Enhancement Proposals; PEP 378: PEP 378 Format Specifier for Thousands Separator.
                                                             (line   32)
* Python Enhancement Proposals; PEP 378 <1>: PEP 378 Format Specifier for Thousands Separator<2>.
                                                             (line   37)
* Python Enhancement Proposals; PEP 378 <2>: Format Specification Mini-Language.
                                                             (line  156)
* Python Enhancement Proposals; PEP 380: PEP 380 Syntax for Delegating to a Subgenerator.
                                                             (line   66)
* Python Enhancement Proposals; PEP 380 <1>: Yield expressions.
                                                             (line  100)
* Python Enhancement Proposals; PEP 380#use-of-stopiteration-to-return-values: The STOP_ITERATION event.
                                                             (line    6)
* Python Enhancement Proposals; PEP 383: Documentation<28>.  (line   29)
* Python Enhancement Proposals; PEP 383 <1>: Error Handlers. (line   50)
* Python Enhancement Proposals; PEP 383 <2>: Socket families.
                                                             (line   15)
* Python Enhancement Proposals; PEP 383 <3>: Locale Encoding.
                                                             (line   15)
* Python Enhancement Proposals; PEP 383 <4>: Locale Encoding.
                                                             (line   52)
* Python Enhancement Proposals; PEP 383 <5>: File System Encoding.
                                                             (line    7)
* Python Enhancement Proposals; PEP 384: Removed<5>.         (line   53)
* Python Enhancement Proposals; PEP 384 <1>: PEP 384 Defining a Stable ABI.
                                                             (line   24)
* Python Enhancement Proposals; PEP 384 <2>: C API<39>.      (line  100)
* Python Enhancement Proposals; PEP 385: Code Repository.    (line   13)
* Python Enhancement Proposals; PEP 387: Warnings.           (line   26)
* Python Enhancement Proposals; PEP 387 <1>: Warnings.       (line   41)
* Python Enhancement Proposals; PEP 387 <2>: C API Stability.
                                                             (line    7)
* Python Enhancement Proposals; PEP 387 <3>: Stable ABI.     (line   13)
* Python Enhancement Proposals; PEP 387 <4>: How does the Python version numbering scheme work?.
                                                             (line   46)
* Python Enhancement Proposals; PEP 389: PEP 389 Argparse Command Line Parsing Module.
                                                             (line   92)
* Python Enhancement Proposals; PEP 389 <1>: PEP 389 The argparse Module for Parsing Command Lines.
                                                             (line  100)
* Python Enhancement Proposals; PEP 391: PEP 391 Dictionary Based Configuration for Logging.
                                                             (line   52)
* Python Enhancement Proposals; PEP 391 <1>: PEP 391 Dictionary-Based Configuration For Logging.
                                                             (line   95)
* Python Enhancement Proposals; PEP 392: What’s New In Python 3 2.
                                                             (line   17)
* Python Enhancement Proposals; PEP 393: Removed<5>.         (line   26)
* Python Enhancement Proposals; PEP 393 <1>: Porting to Python 3 9<2>.
                                                             (line   45)
* Python Enhancement Proposals; PEP 393 <2>: Removed<7>.     (line  101)
* Python Enhancement Proposals; PEP 393 <3>: PEP 393 Flexible String Representation.
                                                             (line   16)
* Python Enhancement Proposals; PEP 393 <4>: Functionality.  (line    6)
* Python Enhancement Proposals; PEP 393 <5>: Performance and resource usage.
                                                             (line   29)
* Python Enhancement Proposals; PEP 393 <6>: Optimizations<10>.
                                                             (line    8)
* Python Enhancement Proposals; PEP 393 <7>: Build and C API Changes<4>.
                                                             (line   12)
* Python Enhancement Proposals; PEP 393 <8>: Deprecated Python modules functions and methods<4>.
                                                             (line   10)
* Python Enhancement Proposals; PEP 393 <9>: Deprecated functions and types of the C API<3>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 393 <10>: Porting C code.
                                                             (line   17)
* Python Enhancement Proposals; PEP 393 <11>: C API<37>.     (line  143)
* Python Enhancement Proposals; PEP 393 <12>: Encodings and Unicode.
                                                             (line    7)
* Python Enhancement Proposals; PEP 393 <13>: sys — System-specific parameters and functions.
                                                             (line 1387)
* Python Enhancement Proposals; PEP 393 <14>: Unicode Objects.
                                                             (line    6)
* Python Enhancement Proposals; PEP 397: PEP 486 Make the Python Launcher aware of virtual environments.
                                                             (line    6)
* Python Enhancement Proposals; PEP 397 <1>: PEP 397 Python Launcher for Windows.
                                                             (line   31)
* Python Enhancement Proposals; PEP 397 <2>: Python launcher for Windows deprecated.
                                                             (line   22)
* Python Enhancement Proposals; PEP 398: What’s New In Python 3 3.
                                                             (line   13)
* Python Enhancement Proposals; PEP 4:   Library Changes.    (line   13)
* Python Enhancement Proposals; PEP 405: PEP 405 Virtual Environments.
                                                             (line   22)
* Python Enhancement Proposals; PEP 405 <1>: venv — Creation of virtual environments.
                                                             (line   47)
* Python Enhancement Proposals; PEP 409: PEP 409 Suppressing exception context.
                                                             (line   63)
* Python Enhancement Proposals; PEP 411: sys — System-specific parameters and functions.
                                                             (line 1053)
* Python Enhancement Proposals; PEP 411 <1>: sys — System-specific parameters and functions.
                                                             (line 1063)
* Python Enhancement Proposals; PEP 411 <2>: sys — System-specific parameters and functions.
                                                             (line 1866)
* Python Enhancement Proposals; PEP 411 <3>: sys — System-specific parameters and functions.
                                                             (line 1886)
* Python Enhancement Proposals; PEP 411 <4>: Glossary.       (line 1438)
* Python Enhancement Proposals; PEP 412: PEP 412 Key-Sharing Dictionary.
                                                             (line   15)
* Python Enhancement Proposals; PEP 412 <1>: functools — Higher-order functions and operations on callable objects.
                                                             (line   90)
* Python Enhancement Proposals; PEP 414: PEP 414 Explicit Unicode literals.
                                                             (line   17)
* Python Enhancement Proposals; PEP 414 <1>: String prefixes.
                                                             (line   35)
* Python Enhancement Proposals; PEP 418: time<8>.            (line    6)
* Python Enhancement Proposals; PEP 420: PEP 420 Implicit Namespace Packages.
                                                             (line    9)
* Python Enhancement Proposals; PEP 420 <1>: PEP 420 Implicit Namespace Packages.
                                                             (line   14)
* Python Enhancement Proposals; PEP 420 <2>: Core and Builtins<185>.
                                                             (line   56)
* Python Enhancement Proposals; PEP 420 <3>: Core and Builtins<190>.
                                                             (line  114)
* Python Enhancement Proposals; PEP 420 <4>: The import system.
                                                             (line   45)
* Python Enhancement Proposals; PEP 420 <5>: Namespace packages.
                                                             (line   27)
* Python Enhancement Proposals; PEP 420 <6>: __path__ attributes on modules.
                                                             (line   23)
* Python Enhancement Proposals; PEP 420 <7>: __path__ attributes on modules.
                                                             (line   23)
* Python Enhancement Proposals; PEP 420 <8>: References.     (line   11)
* Python Enhancement Proposals; PEP 420 <9>: References.     (line   13)
* Python Enhancement Proposals; PEP 420 <10>: References.    (line   13)
* Python Enhancement Proposals; PEP 420 <11>: Introduction<12>.
                                                             (line   71)
* Python Enhancement Proposals; PEP 420 <12>: Glossary.      (line 1216)
* Python Enhancement Proposals; PEP 420 <13>: Glossary.      (line 1413)
* Python Enhancement Proposals; PEP 421: SimpleNamespace.    (line   16)
* Python Enhancement Proposals; PEP 421 <1>: sys — System-specific parameters and functions.
                                                             (line 1183)
* Python Enhancement Proposals; PEP 421 <2>: sys — System-specific parameters and functions.
                                                             (line 1191)
* Python Enhancement Proposals; PEP 424: Other Language Changes<9>.
                                                             (line   57)
* Python Enhancement Proposals; PEP 424 <1>: operator<4>.    (line    8)
* Python Enhancement Proposals; PEP 428: Summary – Release Highlights<3>.
                                                             (line   40)
* Python Enhancement Proposals; PEP 428 <1>: pathlib<14>.    (line   17)
* Python Enhancement Proposals; PEP 428 <2>: pathlib — Object-oriented filesystem paths.
                                                             (line   41)
* Python Enhancement Proposals; PEP 429: What’s New In Python 3 4.
                                                             (line   16)
* Python Enhancement Proposals; PEP 432: Other CPython implementation changes.
                                                             (line    7)
* Python Enhancement Proposals; PEP 432 <1>: Core and Builtins<168>.
                                                             (line  312)
* Python Enhancement Proposals; PEP 434: PEP 434 IDLE Enhancement Exception for All Branches.
                                                             (line    6)
* Python Enhancement Proposals; PEP 434 <1>: idlelib — implementation of IDLE application.
                                                             (line   17)
* Python Enhancement Proposals; PEP 435: Summary – Release Highlights<3>.
                                                             (line   36)
* Python Enhancement Proposals; PEP 435 <1>: enum<9>.        (line    6)
* Python Enhancement Proposals; PEP 435 <2>: enum<9>.        (line   15)
* Python Enhancement Proposals; PEP 436: Summary – Release Highlights<3>.
                                                             (line  120)
* Python Enhancement Proposals; PEP 436 <1>: PEP 436 Argument Clinic.
                                                             (line    6)
* Python Enhancement Proposals; PEP 436 <2>: PEP 436 Argument Clinic.
                                                             (line   28)
* Python Enhancement Proposals; PEP 441: zipapp<2>.          (line    6)
* Python Enhancement Proposals; PEP 441 <1>: zipapp<2>.      (line   24)
* Python Enhancement Proposals; PEP 442: Removed<6>.         (line   68)
* Python Enhancement Proposals; PEP 442 <1>: Summary – Release Highlights<3>.
                                                             (line  113)
* Python Enhancement Proposals; PEP 442 <2>: Summary – Release Highlights<3>.
                                                             (line  115)
* Python Enhancement Proposals; PEP 442 <3>: PEP 442 Safe Object Finalization.
                                                             (line    6)
* Python Enhancement Proposals; PEP 442 <4>: PEP 442 Safe Object Finalization.
                                                             (line   21)
* Python Enhancement Proposals; PEP 442 <5>: C API<52>.      (line   55)
* Python Enhancement Proposals; PEP 442 <6>: gc — Garbage Collector interface.
                                                             (line  286)
* Python Enhancement Proposals; PEP 442 <7>: Thin Ice.       (line   38)
* Python Enhancement Proposals; PEP 442 <8>: Finalization and De-allocation.
                                                             (line   93)
* Python Enhancement Proposals; PEP 442 <9>: Cyclic Isolate Destruction.
                                                             (line   42)
* Python Enhancement Proposals; PEP 442 <10>: PyTypeObject Slots.
                                                             (line 2032)
* Python Enhancement Proposals; PEP 443: Summary – Release Highlights<3>.
                                                             (line   55)
* Python Enhancement Proposals; PEP 443 <1>: functools<6>.   (line   22)
* Python Enhancement Proposals; PEP 443 <2>: Glossary.       (line  760)
* Python Enhancement Proposals; PEP 445: Summary – Release Highlights<3>.
                                                             (line  118)
* Python Enhancement Proposals; PEP 445 <1>: PEP 445 Customization of CPython Memory Allocators.
                                                             (line    6)
* Python Enhancement Proposals; PEP 445 <2>: PEP 445 Customization of CPython Memory Allocators.
                                                             (line   12)
* Python Enhancement Proposals; PEP 445 <3>: Other Improvements<2>.
                                                             (line   63)
* Python Enhancement Proposals; PEP 446: Summary – Release Highlights<3>.
                                                             (line   14)
* Python Enhancement Proposals; PEP 446 <1>: Summary – Release Highlights<3>.
                                                             (line   78)
* Python Enhancement Proposals; PEP 446 <2>: PEP 446 Newly Created File Descriptors Are Non-Inheritable.
                                                             (line    6)
* Python Enhancement Proposals; PEP 446 <3>: PEP 446 Newly Created File Descriptors Are Non-Inheritable.
                                                             (line   26)
* Python Enhancement Proposals; PEP 446 <4>: Core and Builtins<56>.
                                                             (line   20)
* Python Enhancement Proposals; PEP 446 <5>: Operating System Utilities.
                                                             (line  241)
* Python Enhancement Proposals; PEP 448: PEP 448 - Additional Unpacking Generalizations.
                                                             (line    6)
* Python Enhancement Proposals; PEP 448 <1>: PEP 448 - Additional Unpacking Generalizations.
                                                             (line   39)
* Python Enhancement Proposals; PEP 448 <2>: Documentation<75>.
                                                             (line   10)
* Python Enhancement Proposals; PEP 448 <3>: Documentation<79>.
                                                             (line    9)
* Python Enhancement Proposals; PEP 448 <4>: Core and Builtins<193>.
                                                             (line   12)
* Python Enhancement Proposals; PEP 448 <5>: Core and Builtins<196>.
                                                             (line    9)
* Python Enhancement Proposals; PEP 448 <6>: Dictionary displays.
                                                             (line   29)
* Python Enhancement Proposals; PEP 448 <7>: Calls.          (line  122)
* Python Enhancement Proposals; PEP 448 <8>: Expression lists.
                                                             (line   24)
* Python Enhancement Proposals; PEP 450: Summary – Release Highlights<3>.
                                                             (line   47)
* Python Enhancement Proposals; PEP 450 <1>: statistics<5>.  (line    6)
* Python Enhancement Proposals; PEP 450 <2>: statistics<5>.  (line   14)
* Python Enhancement Proposals; PEP 451: zipimport<2>.       (line    8)
* Python Enhancement Proposals; PEP 451 <1>: zipimport<3>.   (line    6)
* Python Enhancement Proposals; PEP 451 <2>: PEP 489 Multi-phase extension module initialization.
                                                             (line    7)
* Python Enhancement Proposals; PEP 451 <3>: Summary – Release Highlights<3>.
                                                             (line   22)
* Python Enhancement Proposals; PEP 451 <4>: PEP 451 A ModuleSpec Type for the Import System.
                                                             (line    6)
* Python Enhancement Proposals; PEP 451 <5>: Library<86>.    (line  455)
* Python Enhancement Proposals; PEP 451 <6>: Core and Builtins<185>.
                                                             (line   75)
* Python Enhancement Proposals; PEP 451 <7>: References.     (line   26)
* Python Enhancement Proposals; PEP 451 <8>: sys — System-specific parameters and functions.
                                                             (line 1419)
* Python Enhancement Proposals; PEP 451 <9>: runpy — Locating and executing Python modules.
                                                             (line   90)
* Python Enhancement Proposals; PEP 451 <10>: runpy — Locating and executing Python modules.
                                                             (line  167)
* Python Enhancement Proposals; PEP 451 <11>: runpy — Locating and executing Python modules.
                                                             (line  186)
* Python Enhancement Proposals; PEP 451 <12>: Introduction<12>.
                                                             (line   75)
* Python Enhancement Proposals; PEP 451 <13>: Module slots.  (line   31)
* Python Enhancement Proposals; PEP 453: Summary – Release Highlights<3>.
                                                             (line   12)
* Python Enhancement Proposals; PEP 453 <1>: Summary – Release Highlights<3>.
                                                             (line   34)
* Python Enhancement Proposals; PEP 453 <2>: Bootstrapping pip By Default.
                                                             (line    6)
* Python Enhancement Proposals; PEP 453 <3>: Documentation Changes.
                                                             (line   21)
* Python Enhancement Proposals; PEP 453 <4>: ensurepip<2>.   (line    7)
* Python Enhancement Proposals; PEP 453 <5>: venv<7>.        (line   13)
* Python Enhancement Proposals; PEP 453 <6>: Other Improvements<2>.
                                                             (line   73)
* Python Enhancement Proposals; PEP 453 <7>: PEP 477 Backport ensurepip PEP 453 to Python 2 7.
                                                             (line    6)
* Python Enhancement Proposals; PEP 453 <8>: Bootstrapping pip By Default<2>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 453 <9>: Documentation Changes<2>.
                                                             (line   21)
* Python Enhancement Proposals; PEP 453 <10>: ensurepip — Bootstrapping the pip installer.
                                                             (line   40)
* Python Enhancement Proposals; PEP 454: Summary – Release Highlights<3>.
                                                             (line   50)
* Python Enhancement Proposals; PEP 454 <1>: tracemalloc<4>. (line    6)
* Python Enhancement Proposals; PEP 454 <2>: tracemalloc<4>. (line   22)
* Python Enhancement Proposals; PEP 456: Summary – Release Highlights<3>.
                                                             (line   75)
* Python Enhancement Proposals; PEP 456 <1>: PEP 456 Secure and Interchangeable Hash Algorithm.
                                                             (line    6)
* Python Enhancement Proposals; PEP 456 <2>: PyHash API.     (line  140)
* Python Enhancement Proposals; PEP 461: PEP 461 - percent formatting support for bytes and bytearray.
                                                             (line    6)
* Python Enhancement Proposals; PEP 461 <1>: PEP 461 - percent formatting support for bytes and bytearray.
                                                             (line   41)
* Python Enhancement Proposals; PEP 461 <2>: Formattazione Bytes stile printf.
                                                             (line  200)
* Python Enhancement Proposals; PEP 465: PEP 465 - A dedicated infix operator for matrix multiplication.
                                                             (line    6)
* Python Enhancement Proposals; PEP 465 <1>: PEP 465 - A dedicated infix operator for matrix multiplication.
                                                             (line   45)
* Python Enhancement Proposals; PEP 465 <2>: Build and C API Changes<3>.
                                                             (line   43)
* Python Enhancement Proposals; PEP 465 <3>: Tools/Demos<61>.
                                                             (line   39)
* Python Enhancement Proposals; PEP 466: PEP 466 Network Security Enhancements for Python 2 7.
                                                             (line    6)
* Python Enhancement Proposals; PEP 466 <1>: PEP 466 Network Security Enhancements for Python 2 7.
                                                             (line   11)
* Python Enhancement Proposals; PEP 466 <2>: PEP 466 Network Security Enhancements for Python 2 7.
                                                             (line   21)
* Python Enhancement Proposals; PEP 466 <3>: PEP 466 Network Security Enhancements for Python 2 7.
                                                             (line   32)
* Python Enhancement Proposals; PEP 468: PEP 468 Preserving Keyword Argument Order.
                                                             (line   12)
* Python Enhancement Proposals; PEP 468 <1>: Library<179>.   (line   87)
* Python Enhancement Proposals; PEP 468 <2>: OrderedDict objects.
                                                             (line  105)
* Python Enhancement Proposals; PEP 471: PEP 471 - os scandir function – a better and faster directory iterator.
                                                             (line    6)
* Python Enhancement Proposals; PEP 471 <1>: PEP 471 - os scandir function – a better and faster directory iterator.
                                                             (line   29)
* Python Enhancement Proposals; PEP 471 <2>: Library<205>.   (line    6)
* Python Enhancement Proposals; PEP 475: PEP 475 Retry system calls failing with EINTR.
                                                             (line   32)
* Python Enhancement Proposals; PEP 475 <1>: PEP 475 Retry system calls failing with EINTR.
                                                             (line   77)
* Python Enhancement Proposals; PEP 475 <2>: Changes in the Python API<9>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 475 <3>: Library<170>.   (line  228)
* Python Enhancement Proposals; PEP 475 <4>: Library<203>.   (line  143)
* Python Enhancement Proposals; PEP 475 <5>: Funzioni Incorporate.
                                                             (line 1570)
* Python Enhancement Proposals; PEP 475 <6>: OS exceptions.  (line   80)
* Python Enhancement Proposals; PEP 475 <7>: File Descriptor Operations.
                                                             (line  410)
* Python Enhancement Proposals; PEP 475 <8>: File Descriptor Operations.
                                                             (line  751)
* Python Enhancement Proposals; PEP 475 <9>: File Descriptor Operations.
                                                             (line  987)
* Python Enhancement Proposals; PEP 475 <10>: Process Management.
                                                             (line  942)
* Python Enhancement Proposals; PEP 475 <11>: I/O Base Classes.
                                                             (line  282)
* Python Enhancement Proposals; PEP 475 <12>: I/O Base Classes.
                                                             (line  300)
* Python Enhancement Proposals; PEP 475 <13>: Functions<4>.  (line  311)
* Python Enhancement Proposals; PEP 475 <14>: Socket Objects.
                                                             (line   28)
* Python Enhancement Proposals; PEP 475 <15>: Socket Objects.
                                                             (line   83)
* Python Enhancement Proposals; PEP 475 <16>: Socket Objects.
                                                             (line  246)
* Python Enhancement Proposals; PEP 475 <17>: Socket Objects.
                                                             (line  261)
* Python Enhancement Proposals; PEP 475 <18>: Socket Objects.
                                                             (line  338)
* Python Enhancement Proposals; PEP 475 <19>: Socket Objects.
                                                             (line  413)
* Python Enhancement Proposals; PEP 475 <20>: Socket Objects.
                                                             (line  433)
* Python Enhancement Proposals; PEP 475 <21>: Socket Objects.
                                                             (line  453)
* Python Enhancement Proposals; PEP 475 <22>: Socket Objects.
                                                             (line  498)
* Python Enhancement Proposals; PEP 475 <23>: select — Waiting for I/O completion.
                                                             (line  161)
* Python Enhancement Proposals; PEP 475 <24>: /dev/poll Polling Objects.
                                                             (line   82)
* Python Enhancement Proposals; PEP 475 <25>: Edge and Level Trigger Polling epoll Objects.
                                                             (line  108)
* Python Enhancement Proposals; PEP 475 <26>: Polling Objects.
                                                             (line   94)
* Python Enhancement Proposals; PEP 475 <27>: Kqueue Objects.
                                                             (line   36)
* Python Enhancement Proposals; PEP 475 <28>: Classes<3>.    (line  133)
* Python Enhancement Proposals; PEP 475 <29>: Module contents<2>.
                                                             (line  619)
* Python Enhancement Proposals; PEP 475 <30>: Module contents<2>.
                                                             (line  638)
* Python Enhancement Proposals; PEP 476: PEP 476 Enabling certificate verification by default for stdlib http clients<2>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 477: PEP 477 Backport ensurepip PEP 453 to Python 2 7.
                                                             (line    6)
* Python Enhancement Proposals; PEP 478: What’s New In Python 3 5.
                                                             (line   17)
* Python Enhancement Proposals; PEP 479: Changes in Python Behavior.
                                                             (line   11)
* Python Enhancement Proposals; PEP 479 <1>: PEP 479 Change StopIteration handling inside generators.
                                                             (line   12)
* Python Enhancement Proposals; PEP 479 <2>: PEP 479 Change StopIteration handling inside generators.
                                                             (line   47)
* Python Enhancement Proposals; PEP 479 <3>: Library<161>.   (line 1268)
* Python Enhancement Proposals; PEP 479 <4>: Library<165>.   (line   52)
* Python Enhancement Proposals; PEP 479 <5>: Core and Builtins<164>.
                                                             (line   34)
* Python Enhancement Proposals; PEP 479 <6>: Library<173>.   (line   95)
* Python Enhancement Proposals; PEP 479 <7>: Library<186>.   (line   80)
* Python Enhancement Proposals; PEP 479 <8>: Library<192>.   (line  326)
* Python Enhancement Proposals; PEP 479 <9>: Concrete exceptions.
                                                             (line  298)
* Python Enhancement Proposals; PEP 479 <10>: Concrete exceptions.
                                                             (line  301)
* Python Enhancement Proposals; PEP 479 <11>: Module Contents<5>.
                                                             (line   43)
* Python Enhancement Proposals; PEP 483: PEP 484 - Type Hints.
                                                             (line   47)
* Python Enhancement Proposals; PEP 483 <1>: Glossary.       (line  768)
* Python Enhancement Proposals; PEP 484: PEP 695 Sintassi dei Parametri di Tipo.
                                                             (line    6)
* Python Enhancement Proposals; PEP 484 <1>: Nuove funzionalità relative agli hint di tipo.
                                                             (line    6)
* Python Enhancement Proposals; PEP 484 <2>: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa.
                                                             (line    6)
* Python Enhancement Proposals; PEP 484 <3>: New Features Related to Type Hints.
                                                             (line    6)
* Python Enhancement Proposals; PEP 484 <4>: PEP 646 Variadic generics.
                                                             (line    6)
* Python Enhancement Proposals; PEP 484 <5>: New Features Related to Type Hints<2>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 484 <6>: PEP 612 Parameter Specification Variables.
                                                             (line    7)
* Python Enhancement Proposals; PEP 484 <7>: PEP 613 TypeAlias.
                                                             (line    6)
* Python Enhancement Proposals; PEP 484 <8>: ast<5>.         (line   17)
* Python Enhancement Proposals; PEP 484 <9>: ast<5>.         (line   20)
* Python Enhancement Proposals; PEP 484 <10>: PEP 560 Core Support for typing module and Generic Types.
                                                             (line    6)
* Python Enhancement Proposals; PEP 484 <11>: PEP 526 Syntax for variable annotations.
                                                             (line    6)
* Python Enhancement Proposals; PEP 484 <12>: PEP 484 - Type Hints.
                                                             (line   16)
* Python Enhancement Proposals; PEP 484 <13>: PEP 484 - Type Hints.
                                                             (line   41)
* Python Enhancement Proposals; PEP 484 <14>: Annotationi delle Funzioni.
                                                             (line    8)
* Python Enhancement Proposals; PEP 484 <15>: Emulating generic types.
                                                             (line   15)
* Python Enhancement Proposals; PEP 484 <16>: Annotated assignment statements.
                                                             (line   45)
* Python Enhancement Proposals; PEP 484 <17>: Function definitions.
                                                             (line  147)
* Python Enhancement Proposals; PEP 484 <18>: Attributi Speciali per oggetti GenericAlias.
                                                             (line   51)
* Python Enhancement Proposals; PEP 484 <19>: NewType.       (line   63)
* Python Enhancement Proposals; PEP 484 <20>: Nominal vs structural subtyping.
                                                             (line    6)
* Python Enhancement Proposals; PEP 484 <21>: Nominal vs structural subtyping.
                                                             (line   14)
* Python Enhancement Proposals; PEP 484 <22>: Building generic types and type aliases.
                                                             (line  113)
* Python Enhancement Proposals; PEP 484 <23>: Functions and decorators.
                                                             (line  280)
* Python Enhancement Proposals; PEP 484 <24>: Root nodes.    (line   60)
* Python Enhancement Proposals; PEP 484 <25>: ast helpers.   (line   18)
* Python Enhancement Proposals; PEP 484 <26>: ast helpers.   (line   29)
* Python Enhancement Proposals; PEP 484 <27>: Compiler flags<2>.
                                                             (line   30)
* Python Enhancement Proposals; PEP 484 <28>: Available start symbols.
                                                             (line   28)
* Python Enhancement Proposals; PEP 484 <29>: Available start symbols.
                                                             (line   37)
* Python Enhancement Proposals; PEP 484 <30>: Glossary.      (line   58)
* Python Enhancement Proposals; PEP 484 <31>: Glossary.      (line  695)
* Python Enhancement Proposals; PEP 484 <32>: Glossary.      (line  768)
* Python Enhancement Proposals; PEP 484 <33>: Glossary.      (line 1796)
* Python Enhancement Proposals; PEP 484 <34>: Glossary.      (line 1813)
* Python Enhancement Proposals; PEP 484 <35>: Glossary.      (line 1843)
* Python Enhancement Proposals; PEP 484#annotating-instance-and-class-methods: PEP 673 Self type.
                                                             (line    8)
* Python Enhancement Proposals; PEP 485: PEP 485 A function for testing approximate equality.
                                                             (line    6)
* Python Enhancement Proposals; PEP 485 <1>: PEP 485 A function for testing approximate equality.
                                                             (line   36)
* Python Enhancement Proposals; PEP 485 <2>: Library<201>.   (line   10)
* Python Enhancement Proposals; PEP 485 <3>: Floating point manipulation functions.
                                                             (line   58)
* Python Enhancement Proposals; PEP 485 <4>: Classification functions.
                                                             (line   56)
* Python Enhancement Proposals; PEP 486: PEP 486 Make the Python Launcher aware of virtual environments.
                                                             (line    6)
* Python Enhancement Proposals; PEP 486 <1>: PEP 486 Make the Python Launcher aware of virtual environments.
                                                             (line   14)
* Python Enhancement Proposals; PEP 486 <2>: Windows<81>.    (line    6)
* Python Enhancement Proposals; PEP 487: PEP 487 Simpler customization of class creation.
                                                             (line   32)
* Python Enhancement Proposals; PEP 487 <1>: PEP 487 Descriptor Protocol Enhancements.
                                                             (line    6)
* Python Enhancement Proposals; PEP 487 <2>: PEP 487 Descriptor Protocol Enhancements.
                                                             (line   33)
* Python Enhancement Proposals; PEP 487 <3>: Changes in the Python API<8>.
                                                             (line  103)
* Python Enhancement Proposals; PEP 487 <4>: Documentation<65>.
                                                             (line   52)
* Python Enhancement Proposals; PEP 487 <5>: Documentation<72>.
                                                             (line    8)
* Python Enhancement Proposals; PEP 487 <6>: Core and Builtins<182>.
                                                             (line   46)
* Python Enhancement Proposals; PEP 488: PEP 488 Elimination of PYO files.
                                                             (line    6)
* Python Enhancement Proposals; PEP 488 <1>: PEP 488 Elimination of PYO files.
                                                             (line   20)
* Python Enhancement Proposals; PEP 488 <2>: Changes in the Python API<9>.
                                                             (line   80)
* Python Enhancement Proposals; PEP 488 <3>: Core and Builtins<200>.
                                                             (line   15)
* Python Enhancement Proposals; PEP 488 <4>: Miscellaneous options.
                                                             (line   88)
* Python Enhancement Proposals; PEP 488 <5>: Miscellaneous options.
                                                             (line   90)
* Python Enhancement Proposals; PEP 488 <6>: Miscellaneous options.
                                                             (line   97)
* Python Enhancement Proposals; PEP 488 <7>: Miscellaneous options.
                                                             (line   99)
* Python Enhancement Proposals; PEP 488 <8>: test support import_helper — Utilities for import tests.
                                                             (line   82)
* Python Enhancement Proposals; PEP 488 <9>: Introduction<12>.
                                                             (line   79)
* Python Enhancement Proposals; PEP 488 <10>: importlib util – Utility code for importers.
                                                             (line   24)
* Python Enhancement Proposals; PEP 488 <11>: importlib util – Utility code for importers.
                                                             (line   64)
* Python Enhancement Proposals; PEP 488 <12>: py_compile — Compile Python source files.
                                                             (line   31)
* Python Enhancement Proposals; PEP 489: PEP 489 Multi-phase extension module initialization.
                                                             (line    6)
* Python Enhancement Proposals; PEP 489 <1>: PEP 489 Multi-phase extension module initialization.
                                                             (line   18)
* Python Enhancement Proposals; PEP 489 <2>: Build and C API Changes<3>.
                                                             (line   37)
* Python Enhancement Proposals; PEP 489 <3>: Library<45>.    (line   84)
* Python Enhancement Proposals; PEP 489 <4>: C API<15>.      (line   23)
* Python Enhancement Proposals; PEP 489 <5>: Library<54>.    (line  254)
* Python Enhancement Proposals; PEP 489 <6>: Library<70>.    (line   24)
* Python Enhancement Proposals; PEP 489 <7>: Library<125>.   (line   64)
* Python Enhancement Proposals; PEP 489 <8>: Library<125>.   (line   79)
* Python Enhancement Proposals; PEP 489 <9>: Library<127>.   (line   28)
* Python Enhancement Proposals; PEP 489 <10>: Library<128>.  (line   68)
* Python Enhancement Proposals; PEP 489 <11>: Library<128>.  (line  177)
* Python Enhancement Proposals; PEP 489 <12>: Library<129>.  (line    7)
* Python Enhancement Proposals; PEP 489 <13>: Library<132>.  (line  103)
* Python Enhancement Proposals; PEP 489 <14>: C API<43>.     (line   11)
* Python Enhancement Proposals; PEP 489 <15>: C API<43>.     (line   14)
* Python Enhancement Proposals; PEP 489 <16>: C API<43>.     (line   17)
* Python Enhancement Proposals; PEP 489 <17>: C API<43>.     (line   20)
* Python Enhancement Proposals; PEP 489 <18>: C API<43>.     (line   23)
* Python Enhancement Proposals; PEP 489 <19>: C API<43>.     (line   26)
* Python Enhancement Proposals; PEP 489 <20>: C API<43>.     (line   29)
* Python Enhancement Proposals; PEP 489 <21>: C API<43>.     (line   38)
* Python Enhancement Proposals; PEP 489 <22>: C API<43>.     (line   41)
* Python Enhancement Proposals; PEP 489 <23>: C API<43>.     (line   44)
* Python Enhancement Proposals; PEP 489 <24>: C API<43>.     (line   47)
* Python Enhancement Proposals; PEP 489 <25>: Library<134>.  (line   31)
* Python Enhancement Proposals; PEP 489 <26>: Library<135>.  (line    7)
* Python Enhancement Proposals; PEP 489 <27>: Library<136>.  (line    7)
* Python Enhancement Proposals; PEP 489 <28>: Library<136>.  (line   10)
* Python Enhancement Proposals; PEP 489 <29>: Library<136>.  (line   13)
* Python Enhancement Proposals; PEP 489 <30>: Library<136>.  (line   16)
* Python Enhancement Proposals; PEP 489 <31>: Library<137>.  (line    7)
* Python Enhancement Proposals; PEP 489 <32>: Library<137>.  (line   10)
* Python Enhancement Proposals; PEP 489 <33>: Library<137>.  (line   13)
* Python Enhancement Proposals; PEP 489 <34>: Library<139>.  (line    7)
* Python Enhancement Proposals; PEP 489 <35>: Library<141>.  (line    7)
* Python Enhancement Proposals; PEP 489 <36>: Library<142>.  (line    7)
* Python Enhancement Proposals; PEP 489 <37>: Library<149>.  (line   75)
* Python Enhancement Proposals; PEP 489 <38>: Library<149>.  (line   78)
* Python Enhancement Proposals; PEP 489 <39>: Library<149>.  (line  423)
* Python Enhancement Proposals; PEP 489 <40>: Core and Builtins<147>.
                                                             (line   28)
* Python Enhancement Proposals; PEP 489 <41>: Core and Builtins<147>.
                                                             (line   35)
* Python Enhancement Proposals; PEP 489 <42>: Core and Builtins<147>.
                                                             (line   50)
* Python Enhancement Proposals; PEP 489 <43>: Core and Builtins<148>.
                                                             (line   46)
* Python Enhancement Proposals; PEP 489 <44>: Core and Builtins<148>.
                                                             (line   49)
* Python Enhancement Proposals; PEP 489 <45>: Core and Builtins<148>.
                                                             (line   51)
* Python Enhancement Proposals; PEP 489 <46>: Core and Builtins<148>.
                                                             (line   71)
* Python Enhancement Proposals; PEP 489 <47>: Core and Builtins<148>.
                                                             (line   75)
* Python Enhancement Proposals; PEP 489 <48>: Core and Builtins<149>.
                                                             (line   17)
* Python Enhancement Proposals; PEP 489 <49>: Core and Builtins<149>.
                                                             (line   20)
* Python Enhancement Proposals; PEP 489 <50>: Core and Builtins<149>.
                                                             (line   40)
* Python Enhancement Proposals; PEP 489 <51>: Core and Builtins<149>.
                                                             (line   54)
* Python Enhancement Proposals; PEP 489 <52>: Core and Builtins<149>.
                                                             (line  109)
* Python Enhancement Proposals; PEP 489 <53>: Core and Builtins<149>.
                                                             (line  118)
* Python Enhancement Proposals; PEP 489 <54>: Core and Builtins<150>.
                                                             (line   29)
* Python Enhancement Proposals; PEP 489 <55>: Core and Builtins<150>.
                                                             (line   32)
* Python Enhancement Proposals; PEP 489 <56>: Core and Builtins<150>.
                                                             (line   52)
* Python Enhancement Proposals; PEP 489 <57>: Core and Builtins<150>.
                                                             (line   55)
* Python Enhancement Proposals; PEP 489 <58>: Core and Builtins<150>.
                                                             (line   58)
* Python Enhancement Proposals; PEP 489 <59>: Core and Builtins<151>.
                                                             (line   62)
* Python Enhancement Proposals; PEP 489 <60>: Introduction<12>.
                                                             (line   83)
* Python Enhancement Proposals; PEP 489 <61>: importlib machinery – Importers and path hooks.
                                                             (line   77)
* Python Enhancement Proposals; PEP 489 <62>: importlib machinery – Importers and path hooks.
                                                             (line  299)
* Python Enhancement Proposals; PEP 489 <63>: importlib machinery – Importers and path hooks.
                                                             (line  318)
* Python Enhancement Proposals; PEP 489 <64>: importlib machinery – Importers and path hooks.
                                                             (line  324)
* Python Enhancement Proposals; PEP 489 <65>: importlib util – Utility code for importers.
                                                             (line  183)
* Python Enhancement Proposals; PEP 489 <66>: Creating extensions without third party tools.
                                                             (line   14)
* Python Enhancement Proposals; PEP 489 <67>: Defining extension modules.
                                                             (line   45)
* Python Enhancement Proposals; PEP 489 <68>: Initialization function.
                                                             (line   60)
* Python Enhancement Proposals; PEP 489 <69>: Sub-interpreter support.
                                                             (line   81)
* Python Enhancement Proposals; PEP 492: PEP 525 Asynchronous Generators.
                                                             (line    6)
* Python Enhancement Proposals; PEP 492 <1>: New Keywords.   (line    7)
* Python Enhancement Proposals; PEP 492 <2>: PEP 492 - Coroutines with async and await syntax.
                                                             (line    6)
* Python Enhancement Proposals; PEP 492 <3>: PEP 492 - Coroutines with async and await syntax.
                                                             (line   97)
* Python Enhancement Proposals; PEP 492 <4>: New Keywords<2>.
                                                             (line    7)
* Python Enhancement Proposals; PEP 492 <5>: Changes in the C API<8>.
                                                             (line   25)
* Python Enhancement Proposals; PEP 492 <6>: Core and Builtins<167>.
                                                             (line   98)
* Python Enhancement Proposals; PEP 492 <7>: Library<187>.   (line   51)
* Python Enhancement Proposals; PEP 492 <8>: Library<193>.   (line   16)
* Python Enhancement Proposals; PEP 492 <9>: Core and Builtins<197>.
                                                             (line   14)
* Python Enhancement Proposals; PEP 492 <10>: Awaitable Objects.
                                                             (line   33)
* Python Enhancement Proposals; PEP 492 <11>: Yield expressions.
                                                             (line  107)
* Python Enhancement Proposals; PEP 492 <12>: The async with statement.
                                                             (line   45)
* Python Enhancement Proposals; PEP 492 <13>: Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  189)
* Python Enhancement Proposals; PEP 492 <14>: Code Objects Bit Flags.
                                                             (line   38)
* Python Enhancement Proposals; PEP 492 <15>: Code Objects Bit Flags.
                                                             (line   47)
* Python Enhancement Proposals; PEP 492 <16>: Glossary.      (line   99)
* Python Enhancement Proposals; PEP 492 <17>: Glossary.      (line  132)
* Python Enhancement Proposals; PEP 492 <18>: Glossary.      (line  139)
* Python Enhancement Proposals; PEP 492 <19>: Glossary.      (line  148)
* Python Enhancement Proposals; PEP 492 <20>: Glossary.      (line  200)
* Python Enhancement Proposals; PEP 492 <21>: Glossary.      (line  405)
* Python Enhancement Proposals; PEP 492 <22>: Glossary.      (line  412)
* Python Enhancement Proposals; PEP 493: PEP 493 HTTPS verification migration tools for Python 2 7.
                                                             (line    6)
* Python Enhancement Proposals; PEP 494: What’s New In Python 3 6.
                                                             (line   17)
* Python Enhancement Proposals; PEP 495: PEP 495 Local Time Disambiguation.
                                                             (line   13)
* Python Enhancement Proposals; PEP 495 <1>: PEP 495 Local Time Disambiguation.
                                                             (line   36)
* Python Enhancement Proposals; PEP 495 <2>: Library<185>.   (line   96)
* Python Enhancement Proposals; PEP 495 <3>: Using ZoneInfo. (line   34)
* Python Enhancement Proposals; PEP 498: PEP 498 Formatted string literals.
                                                             (line    6)
* Python Enhancement Proposals; PEP 498 <1>: PEP 498 Formatted string literals.
                                                             (line   27)
* Python Enhancement Proposals; PEP 498 <2>: Core and Builtins<185>.
                                                             (line  283)
* Python Enhancement Proposals; PEP 498 <3>: f-strings.      (line  151)
* Python Enhancement Proposals; PEP 498 <4>: Glossary.       (line  594)
* Python Enhancement Proposals; PEP 5:   PEP 230 Warning Framework.
                                                             (line   66)
* Python Enhancement Proposals; PEP 5 <1>: Is it reasonable to propose incompatible changes to Python?.
                                                             (line   14)
* Python Enhancement Proposals; PEP 506: secrets.            (line   19)
* Python Enhancement Proposals; PEP 506 <1>: Library<188>.   (line   60)
* Python Enhancement Proposals; PEP 506 <2>: secrets — Generate secure random numbers for managing secrets.
                                                             (line   24)
* Python Enhancement Proposals; PEP 509: C API<15>.          (line   16)
* Python Enhancement Proposals; PEP 511: Changes in the Python API<8>.
                                                             (line   33)
* Python Enhancement Proposals; PEP 514: Windows py exe launcher improvements.
                                                             (line    8)
* Python Enhancement Proposals; PEP 514 <1>: Windows<30>.    (line   13)
* Python Enhancement Proposals; PEP 514 <2>: Windows<73>.    (line    8)
* Python Enhancement Proposals; PEP 514 <3>: From the command-line.
                                                             (line   45)
* Python Enhancement Proposals; PEP 515: fractions<4>.       (line    6)
* Python Enhancement Proposals; PEP 515 <1>: PEP 515 Underscores in Numeric Literals.
                                                             (line    6)
* Python Enhancement Proposals; PEP 515 <2>: PEP 515 Underscores in Numeric Literals.
                                                             (line   32)
* Python Enhancement Proposals; PEP 515 <3>: Core and Builtins<181>.
                                                             (line   15)
* Python Enhancement Proposals; PEP 515 <4>: Core and Builtins<181>.
                                                             (line   43)
* Python Enhancement Proposals; PEP 515 <5>: Format Specification Mini-Language.
                                                             (line  159)
* Python Enhancement Proposals; PEP 515 <6>: fractions — Rational numbers.
                                                             (line   97)
* Python Enhancement Proposals; PEP 519: PEP 519 Adding a file system path protocol.
                                                             (line   62)
* Python Enhancement Proposals; PEP 519 <1>: Library<185>.   (line    6)
* Python Enhancement Proposals; PEP 519 <2>: Core and Builtins<184>.
                                                             (line   19)
* Python Enhancement Proposals; PEP 519 <3>: Library<187>.   (line   31)
* Python Enhancement Proposals; PEP 519 <4>: Library<187>.   (line   42)
* Python Enhancement Proposals; PEP 519 <5>: Library<187>.   (line   44)
* Python Enhancement Proposals; PEP 519 <6>: C API<73>.      (line    6)
* Python Enhancement Proposals; PEP 519 <7>: Glossary.       (line 1392)
* Python Enhancement Proposals; PEP 520: PEP 520 Preserving Class Attribute Definition Order.
                                                             (line   17)
* Python Enhancement Proposals; PEP 523: Nuove Funzionalità<2>.
                                                             (line   19)
* Python Enhancement Proposals; PEP 523 <1>: Porting to Python 3 11<2>.
                                                             (line   33)
* Python Enhancement Proposals; PEP 523 <2>: Porting to Python 3 9<2>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 523 <3>: PEP 523 Adding a frame evaluation API to CPython.
                                                             (line   12)
* Python Enhancement Proposals; PEP 523 <4>: PEP 523 Adding a frame evaluation API to CPython.
                                                             (line   26)
* Python Enhancement Proposals; PEP 523 <5>: Core and Builtins<59>.
                                                             (line   23)
* Python Enhancement Proposals; PEP 523 <6>: Tools/Demos<43>.
                                                             (line    7)
* Python Enhancement Proposals; PEP 523 <7>: Tools/Demos<47>.
                                                             (line    7)
* Python Enhancement Proposals; PEP 523 <8>: Core and Builtins<181>.
                                                             (line   83)
* Python Enhancement Proposals; PEP 523 <9>: Internal Frames.
                                                             (line    6)
* Python Enhancement Proposals; PEP 523 <10>: Low-level API. (line  240)
* Python Enhancement Proposals; PEP 523 <11>: Low-level API. (line  249)
* Python Enhancement Proposals; PEP 524: Summary – Release highlights<6>.
                                                             (line   77)
* Python Enhancement Proposals; PEP 524 <1>: os<9>.          (line   20)
* Python Enhancement Proposals; PEP 524 <2>: os<9>.          (line   25)
* Python Enhancement Proposals; PEP 524 <3>: Library<184>.   (line  150)
* Python Enhancement Proposals; PEP 524 <4>: Library<184>.   (line  154)
* Python Enhancement Proposals; PEP 524 <5>: Random numbers<2>.
                                                             (line   42)
* Python Enhancement Proposals; PEP 525: PEP 525 Asynchronous Generators.
                                                             (line   23)
* Python Enhancement Proposals; PEP 525 <1>: Core and Builtins<181>.
                                                             (line   49)
* Python Enhancement Proposals; PEP 525 <2>: Yield expressions.
                                                             (line  105)
* Python Enhancement Proposals; PEP 525 <3>: Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  189)
* Python Enhancement Proposals; PEP 525 <4>: sys — System-specific parameters and functions.
                                                             (line 1050)
* Python Enhancement Proposals; PEP 525 <5>: sys — System-specific parameters and functions.
                                                             (line 1861)
* Python Enhancement Proposals; PEP 525 <6>: Code Objects Bit Flags.
                                                             (line   56)
* Python Enhancement Proposals; PEP 525 <7>: Asynchronous Generator Objects.
                                                             (line    9)
* Python Enhancement Proposals; PEP 525 <8>: Glossary.       (line  133)
* Python Enhancement Proposals; PEP 526: Other Language Changes<3>.
                                                             (line   56)
* Python Enhancement Proposals; PEP 526 <1>: ast<5>.         (line   18)
* Python Enhancement Proposals; PEP 526 <2>: PEP 563 Postponed Evaluation of Annotations.
                                                             (line    8)
* Python Enhancement Proposals; PEP 526 <3>: PEP 526 Syntax for variable annotations.
                                                             (line   30)
* Python Enhancement Proposals; PEP 526 <4>: typing<10>.     (line   23)
* Python Enhancement Proposals; PEP 526 <5>: Core and Builtins<181>.
                                                             (line   51)
* Python Enhancement Proposals; PEP 526 <6>: Annotated assignment statements.
                                                             (line   39)
* Python Enhancement Proposals; PEP 526 <7>: Function definitions.
                                                             (line  151)
* Python Enhancement Proposals; PEP 526 <8>: Special forms.  (line  204)
* Python Enhancement Proposals; PEP 526 <9>: Other special directives.
                                                             (line   71)
* Python Enhancement Proposals; PEP 526 <10>: dataclasses — Data Classes.
                                                             (line   16)
* Python Enhancement Proposals; PEP 526 <11>: Class variables.
                                                             (line    8)
* Python Enhancement Proposals; PEP 526 <12>: Annotation semantics.
                                                             (line   11)
* Python Enhancement Proposals; PEP 526 <13>: Annotation semantics.
                                                             (line   47)
* Python Enhancement Proposals; PEP 526 <14>: ast helpers.   (line   18)
* Python Enhancement Proposals; PEP 526 <15>: Compiler flags<2>.
                                                             (line   30)
* Python Enhancement Proposals; PEP 526 <16>: Glossary.      (line   58)
* Python Enhancement Proposals; PEP 526 <17>: Glossary.      (line 1843)
* Python Enhancement Proposals; PEP 528: PEP 528 Change Windows console encoding to UTF-8.
                                                             (line   17)
* Python Enhancement Proposals; PEP 528 <1>: UTF-8 mode.     (line   33)
* Python Enhancement Proposals; PEP 528 <2>: Global configuration variables.
                                                             (line  172)
* Python Enhancement Proposals; PEP 528 <3>: PyConfig.       (line  568)
* Python Enhancement Proposals; PEP 529: Changes in the Python API<5>.
                                                             (line    7)
* Python Enhancement Proposals; PEP 529 <1>: PEP 529 Change Windows filesystem encoding to UTF-8.
                                                             (line   22)
* Python Enhancement Proposals; PEP 529 <2>: Documentation<28>.
                                                             (line   29)
* Python Enhancement Proposals; PEP 529 <3>: Library<156>.   (line  619)
* Python Enhancement Proposals; PEP 529 <4>: Windows<68>.    (line   14)
* Python Enhancement Proposals; PEP 529 <5>: Environment variables.
                                                             (line  356)
* Python Enhancement Proposals; PEP 529 <6>: UTF-8 mode.     (line   36)
* Python Enhancement Proposals; PEP 529 <7>: Files and Directories.
                                                             (line  303)
* Python Enhancement Proposals; PEP 529 <8>: sys — System-specific parameters and functions.
                                                             (line  828)
* Python Enhancement Proposals; PEP 529 <9>: sys — System-specific parameters and functions.
                                                             (line 1981)
* Python Enhancement Proposals; PEP 529 <10>: File System Encoding.
                                                             (line    7)
* Python Enhancement Proposals; PEP 529 <11>: Global configuration variables.
                                                             (line  154)
* Python Enhancement Proposals; PEP 530: PEP 530 Asynchronous Comprehensions.
                                                             (line    6)
* Python Enhancement Proposals; PEP 530 <1>: PEP 530 Asynchronous Comprehensions.
                                                             (line   19)
* Python Enhancement Proposals; PEP 530 <2>: Core and Builtins<181>.
                                                             (line  145)
* Python Enhancement Proposals; PEP 530 <3>: Displays for lists sets and dictionaries.
                                                             (line   56)
* Python Enhancement Proposals; PEP 538: PEP 538 Legacy C Locale Coercion.
                                                             (line   11)
* Python Enhancement Proposals; PEP 538 <1>: PEP 538 Legacy C Locale Coercion.
                                                             (line   36)
* Python Enhancement Proposals; PEP 538 <2>: PEP 538 Legacy C Locale Coercion.
                                                             (line   48)
* Python Enhancement Proposals; PEP 538 <3>: PEP 540 Forced UTF-8 Runtime Mode.
                                                             (line   27)
* Python Enhancement Proposals; PEP 538 <4>: Documentation<55>.
                                                             (line   68)
* Python Enhancement Proposals; PEP 538 <5>: Documentation<56>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 538 <6>: Core and Builtins<168>.
                                                             (line  134)
* Python Enhancement Proposals; PEP 538 <7>: Environment variables.
                                                             (line  425)
* Python Enhancement Proposals; PEP 538 <8>: General Options.
                                                             (line   88)
* Python Enhancement Proposals; PEP 538 <9>: locale — Internationalization services.
                                                             (line  540)
* Python Enhancement Proposals; PEP 538 <10>: Python Configuration.
                                                             (line   13)
* Python Enhancement Proposals; PEP 539: PEP 539 New C API for Thread-Local Storage.
                                                             (line   12)
* Python Enhancement Proposals; PEP 539 <1>: PEP 539 New C API for Thread-Local Storage.
                                                             (line   30)
* Python Enhancement Proposals; PEP 539 <2>: C API<62>.      (line   13)
* Python Enhancement Proposals; PEP 539 <3>: Thread Specific Storage TSS API.
                                                             (line   15)
* Python Enhancement Proposals; PEP 540: PEP 540 Forced UTF-8 Runtime Mode.
                                                             (line   18)
* Python Enhancement Proposals; PEP 540 <1>: PEP 540 Forced UTF-8 Runtime Mode.
                                                             (line   35)
* Python Enhancement Proposals; PEP 540 <2>: Core and Builtins<165>.
                                                             (line   63)
* Python Enhancement Proposals; PEP 540 <3>: Python UTF-8 Mode.
                                                             (line    6)
* Python Enhancement Proposals; PEP 540 <4>: locale — Internationalization services.
                                                             (line  540)
* Python Enhancement Proposals; PEP 540 <5>: Python Configuration.
                                                             (line   14)
* Python Enhancement Proposals; PEP 544: typing<9>.          (line   32)
* Python Enhancement Proposals; PEP 544 <1>: Nominal vs structural subtyping.
                                                             (line   23)
* Python Enhancement Proposals; PEP 544 <2>: Other special directives.
                                                             (line  164)
* Python Enhancement Proposals; PEP 545: PEP 545 Python Documentation Translations.
                                                             (line    6)
* Python Enhancement Proposals; PEP 545 <1>: PEP 545 Python Documentation Translations.
                                                             (line   20)
* Python Enhancement Proposals; PEP 552: Other CPython Implementation Changes.
                                                             (line   16)
* Python Enhancement Proposals; PEP 552 <1>: PEP 552 Hash-based pyc Files.
                                                             (line   15)
* Python Enhancement Proposals; PEP 552 <2>: PEP 552 Hash-based pyc Files.
                                                             (line   35)
* Python Enhancement Proposals; PEP 552 <3>: Library<161>.   (line  795)
* Python Enhancement Proposals; PEP 552 <4>: Core and Builtins<165>.
                                                             (line   75)
* Python Enhancement Proposals; PEP 552 <5>: Introduction<12>.
                                                             (line   87)
* Python Enhancement Proposals; PEP 552 <6>: py_compile — Compile Python source files.
                                                             (line   82)
* Python Enhancement Proposals; PEP 552 <7>: PyConfig.       (line  275)
* Python Enhancement Proposals; PEP 553: PEP 553 Built-in breakpoint.
                                                             (line   20)
* Python Enhancement Proposals; PEP 553 <1>: Core and Builtins<167>.
                                                             (line   72)
* Python Enhancement Proposals; PEP 554: PEP 684 Un GIL per interprete.
                                                             (line   10)
* Python Enhancement Proposals; PEP 554 <1>: concurrent interpreters — Multiple interpreters in the same process.
                                                             (line   36)
* Python Enhancement Proposals; PEP 554 <2>: A Per-Interpreter GIL.
                                                             (line   13)
* Python Enhancement Proposals; PEP 557: dataclasses<3>.     (line   26)
* Python Enhancement Proposals; PEP 557 <1>: dataclasses — Data Classes.
                                                             (line   13)
* Python Enhancement Proposals; PEP 560: PEP 560 Core Support for typing module and Generic Types.
                                                             (line   20)
* Python Enhancement Proposals; PEP 560 <1>: types<5>.       (line   12)
* Python Enhancement Proposals; PEP 560 <2>: Core and Builtins<165>.
                                                             (line   66)
* Python Enhancement Proposals; PEP 560 <3>: Resolving MRO entries.
                                                             (line   30)
* Python Enhancement Proposals; PEP 560 <4>: __class_getitem__ versus __getitem__.
                                                             (line   85)
* Python Enhancement Proposals; PEP 560 <5>: Dynamic Type Creation.
                                                             (line   60)
* Python Enhancement Proposals; PEP 560 <6>: Dynamic Type Creation.
                                                             (line   76)
* Python Enhancement Proposals; PEP 560 <7>: Dynamic Type Creation.
                                                             (line  114)
* Python Enhancement Proposals; PEP 562: PEP 562 Customization of Access to Module Attributes.
                                                             (line   16)
* Python Enhancement Proposals; PEP 562 <1>: Library<168>.   (line   63)
* Python Enhancement Proposals; PEP 562 <2>: Core and Builtins<165>.
                                                             (line   69)
* Python Enhancement Proposals; PEP 562 <3>: Customizing module attribute access.
                                                             (line   58)
* Python Enhancement Proposals; PEP 563: from __future__ import annotations.
                                                             (line    6)
* Python Enhancement Proposals; PEP 563 <1>: PEP 563 may not be the future.
                                                             (line    6)
* Python Enhancement Proposals; PEP 563 <2>: PEP 563 Postponed Evaluation of Annotations.
                                                             (line   51)
* Python Enhancement Proposals; PEP 563 <3>: Library<118>.   (line  300)
* Python Enhancement Proposals; PEP 563 <4>: Core and Builtins<131>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 563 <5>: Future statements.
                                                             (line   34)
* Python Enhancement Proposals; PEP 563 <6>: Function definitions.
                                                             (line  156)
* Python Enhancement Proposals; PEP 563 <7>: Module Contents<5>.
                                                             (line   47)
* Python Enhancement Proposals; PEP 563 <8>: Annotation semantics.
                                                             (line   15)
* Python Enhancement Proposals; PEP 563 <9>: Annotation semantics.
                                                             (line   52)
* Python Enhancement Proposals; PEP 564: PEP 564 New Time Functions With Nanosecond Resolution.
                                                             (line    8)
* Python Enhancement Proposals; PEP 564 <1>: PEP 564 New Time Functions With Nanosecond Resolution.
                                                             (line   33)
* Python Enhancement Proposals; PEP 564 <2>: time<5>.        (line    6)
* Python Enhancement Proposals; PEP 564 <3>: Library<170>.   (line  299)
* Python Enhancement Proposals; PEP 565: PEP 565 Show DeprecationWarning in __main__.
                                                             (line   41)
* Python Enhancement Proposals; PEP 565 <1>: Warnings.       (line   23)
* Python Enhancement Proposals; PEP 566: Distribution metadata.
                                                             (line   34)
* Python Enhancement Proposals; PEP 567: contextvars<2>.     (line   20)
* Python Enhancement Proposals; PEP 567 <1>: asyncio<10>.    (line   19)
* Python Enhancement Proposals; PEP 567 <2>: Documentation<55>.
                                                             (line   86)
* Python Enhancement Proposals; PEP 567 <3>: Documentation<57>.
                                                             (line    9)
* Python Enhancement Proposals; PEP 567 <4>: Core and Builtins<164>.
                                                             (line   63)
* Python Enhancement Proposals; PEP 567 <5>: contextvars — Context Variables.
                                                             (line   18)
* Python Enhancement Proposals; PEP 567 <6>: Scheduling callbacks.
                                                             (line   42)
* Python Enhancement Proposals; PEP 567 <7>: Scheduling delayed callbacks.
                                                             (line   35)
* Python Enhancement Proposals; PEP 567 <8>: Scheduling delayed callbacks.
                                                             (line   57)
* Python Enhancement Proposals; PEP 567 <9>: Future Object.  (line  104)
* Python Enhancement Proposals; PEP 570: Positional-only parameters.
                                                             (line   70)
* Python Enhancement Proposals; PEP 570 <1>: Changes in the Python API<5>.
                                                             (line  161)
* Python Enhancement Proposals; PEP 570 <2>: Core and Builtins<155>.
                                                             (line   36)
* Python Enhancement Proposals; PEP 570 <3>: Function definitions.
                                                             (line  108)
* Python Enhancement Proposals; PEP 572: Altre modifiche al Linguaggio.
                                                             (line   31)
* Python Enhancement Proposals; PEP 572 <1>: Assignment expressions.
                                                             (line   41)
* Python Enhancement Proposals; PEP 572 <2>: CPython bytecode changes<5>.
                                                             (line   27)
* Python Enhancement Proposals; PEP 572 <3>: Core and Builtins<66>.
                                                             (line   40)
* Python Enhancement Proposals; PEP 572 <4>: Documentation<46>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 572 <5>: Core and Builtins<153>.
                                                             (line  184)
* Python Enhancement Proposals; PEP 572 <6>: Core and Builtins<158>.
                                                             (line   92)
* Python Enhancement Proposals; PEP 572 <7>: Dictionary displays.
                                                             (line   48)
* Python Enhancement Proposals; PEP 572 <8>: Assignment expressions<2>.
                                                             (line   29)
* Python Enhancement Proposals; PEP 572 <9>: Capture Patterns.
                                                             (line   17)
* Python Enhancement Proposals; PEP 572 <10>: Why can’t I use an assignment in an expression?.
                                                             (line   14)
* Python Enhancement Proposals; PEP 573: Summary – Release highlights<4>.
                                                             (line   27)
* Python Enhancement Proposals; PEP 573 <1>: New Features<8>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 573 <2>: Core and Builtins<147>.
                                                             (line   19)
* Python Enhancement Proposals; PEP 573 <3>: C API<46>.      (line   57)
* Python Enhancement Proposals; PEP 574: Pickle protocol 5 with out-of-band data buffers.
                                                             (line   17)
* Python Enhancement Proposals; PEP 574 <1>: Data stream format.
                                                             (line   47)
* Python Enhancement Proposals; PEP 574 <2>: Example<4>.     (line   63)
* Python Enhancement Proposals; PEP 578: PEP 578 Python Runtime Audit Hooks.
                                                             (line   12)
* Python Enhancement Proposals; PEP 578 <1>: Audit events table.
                                                             (line    8)
* Python Enhancement Proposals; PEP 578 <2>: sys — System-specific parameters and functions.
                                                             (line   58)
* Python Enhancement Proposals; PEP 578 <3>: System Functions.
                                                             (line  139)
* Python Enhancement Proposals; PEP 584: Summary – Release highlights<4>.
                                                             (line    8)
* Python Enhancement Proposals; PEP 584 <1>: Dictionary Merge & Update Operators.
                                                             (line   19)
* Python Enhancement Proposals; PEP 584 <2>: Library<151>.   (line  193)
* Python Enhancement Proposals; PEP 584 <3>: Library<151>.   (line  196)
* Python Enhancement Proposals; PEP 584 <4>: Library<151>.   (line  210)
* Python Enhancement Proposals; PEP 584 <5>: Library<152>.   (line   49)
* Python Enhancement Proposals; PEP 584 <6>: Library<152>.   (line   62)
* Python Enhancement Proposals; PEP 584 <7>: Library<152>.   (line  120)
* Python Enhancement Proposals; PEP 584 <8>: Library<152>.   (line  142)
* Python Enhancement Proposals; PEP 584 <9>: ChainMap objects.
                                                             (line   92)
* Python Enhancement Proposals; PEP 584 <10>: defaultdict objects.
                                                             (line   57)
* Python Enhancement Proposals; PEP 584 <11>: OrderedDict objects.
                                                             (line  110)
* Python Enhancement Proposals; PEP 584 <12>: weakref — Weak references.
                                                             (line  201)
* Python Enhancement Proposals; PEP 584 <13>: weakref — Weak references.
                                                             (line  221)
* Python Enhancement Proposals; PEP 584 <14>: Standard Interpreter Types.
                                                             (line  237)
* Python Enhancement Proposals; PEP 584 <15>: Process Parameters.
                                                             (line   60)
* Python Enhancement Proposals; PEP 584 <16>: Process Parameters.
                                                             (line   76)
* Python Enhancement Proposals; PEP 585: Summary – Release highlights<4>.
                                                             (line   10)
* Python Enhancement Proposals; PEP 585 <1>: Type Hinting Generics in Standard Collections.
                                                             (line   18)
* Python Enhancement Proposals; PEP 585 <2>: Library<73>.    (line  158)
* Python Enhancement Proposals; PEP 585 <3>: Library<104>.   (line  124)
* Python Enhancement Proposals; PEP 585 <4>: Documentation<34>.
                                                             (line   31)
* Python Enhancement Proposals; PEP 585 <5>: Attributi Speciali per oggetti GenericAlias.
                                                             (line   55)
* Python Enhancement Proposals; PEP 585 <6>: collections abc — Abstract Base Classes for Containers.
                                                             (line   87)
* Python Enhancement Proposals; PEP 585 <7>: Standard Interpreter Types.
                                                             (line  176)
* Python Enhancement Proposals; PEP 585 <8>: Introspection helpers.
                                                             (line  162)
* Python Enhancement Proposals; PEP 585 <9>: Deprecated aliases.
                                                             (line   10)
* Python Enhancement Proposals; PEP 585 <10>: Aliases to built-in types.
                                                             (line   15)
* Python Enhancement Proposals; PEP 585 <11>: Aliases to built-in types.
                                                             (line   27)
* Python Enhancement Proposals; PEP 585 <12>: Aliases to built-in types.
                                                             (line   39)
* Python Enhancement Proposals; PEP 585 <13>: Aliases to built-in types.
                                                             (line   47)
* Python Enhancement Proposals; PEP 585 <14>: Aliases to built-in types.
                                                             (line   58)
* Python Enhancement Proposals; PEP 585 <15>: Aliases to built-in types.
                                                             (line   71)
* Python Enhancement Proposals; PEP 585 <16>: Aliases to types in collections.
                                                             (line   14)
* Python Enhancement Proposals; PEP 585 <17>: Aliases to types in collections.
                                                             (line   25)
* Python Enhancement Proposals; PEP 585 <18>: Aliases to types in collections.
                                                             (line   36)
* Python Enhancement Proposals; PEP 585 <19>: Aliases to types in collections.
                                                             (line   46)
* Python Enhancement Proposals; PEP 585 <20>: Aliases to types in collections.
                                                             (line   56)
* Python Enhancement Proposals; PEP 585 <21>: Aliases to other concrete types.
                                                             (line   18)
* Python Enhancement Proposals; PEP 585 <22>: Aliases to container ABCs in collections abc.
                                                             (line   11)
* Python Enhancement Proposals; PEP 585 <23>: Aliases to container ABCs in collections abc.
                                                             (line   44)
* Python Enhancement Proposals; PEP 585 <24>: Aliases to container ABCs in collections abc.
                                                             (line   52)
* Python Enhancement Proposals; PEP 585 <25>: Aliases to container ABCs in collections abc.
                                                             (line   61)
* Python Enhancement Proposals; PEP 585 <26>: Aliases to container ABCs in collections abc.
                                                             (line   69)
* Python Enhancement Proposals; PEP 585 <27>: Aliases to container ABCs in collections abc.
                                                             (line   77)
* Python Enhancement Proposals; PEP 585 <28>: Aliases to container ABCs in collections abc.
                                                             (line   85)
* Python Enhancement Proposals; PEP 585 <29>: Aliases to container ABCs in collections abc.
                                                             (line   93)
* Python Enhancement Proposals; PEP 585 <30>: Aliases to container ABCs in collections abc.
                                                             (line  102)
* Python Enhancement Proposals; PEP 585 <31>: Aliases to container ABCs in collections abc.
                                                             (line  109)
* Python Enhancement Proposals; PEP 585 <32>: Aliases to container ABCs in collections abc.
                                                             (line  117)
* Python Enhancement Proposals; PEP 585 <33>: Aliases to container ABCs in collections abc.
                                                             (line  125)
* Python Enhancement Proposals; PEP 585 <34>: Aliases to asynchronous ABCs in collections abc.
                                                             (line   18)
* Python Enhancement Proposals; PEP 585 <35>: Aliases to asynchronous ABCs in collections abc.
                                                             (line   33)
* Python Enhancement Proposals; PEP 585 <36>: Aliases to asynchronous ABCs in collections abc.
                                                             (line   46)
* Python Enhancement Proposals; PEP 585 <37>: Aliases to asynchronous ABCs in collections abc.
                                                             (line   56)
* Python Enhancement Proposals; PEP 585 <38>: Aliases to asynchronous ABCs in collections abc.
                                                             (line   66)
* Python Enhancement Proposals; PEP 585 <39>: Aliases to other ABCs in collections abc.
                                                             (line   11)
* Python Enhancement Proposals; PEP 585 <40>: Aliases to other ABCs in collections abc.
                                                             (line   19)
* Python Enhancement Proposals; PEP 585 <41>: Aliases to other ABCs in collections abc.
                                                             (line   31)
* Python Enhancement Proposals; PEP 585 <42>: Aliases to other ABCs in collections abc.
                                                             (line   48)
* Python Enhancement Proposals; PEP 585 <43>: Aliases to other ABCs in collections abc.
                                                             (line   66)
* Python Enhancement Proposals; PEP 585 <44>: Aliases to contextlib ABCs.
                                                             (line   19)
* Python Enhancement Proposals; PEP 585 <45>: Aliases to contextlib ABCs.
                                                             (line   38)
* Python Enhancement Proposals; PEP 585 <46>: Deprecation Timeline of Major Features.
                                                             (line   15)
* Python Enhancement Proposals; PEP 585 <47>: Glossary.      (line  769)
* Python Enhancement Proposals; PEP 586: typing<6>.          (line    8)
* Python Enhancement Proposals; PEP 586 <1>: typing<8>.      (line    6)
* Python Enhancement Proposals; PEP 586 <2>: typing<9>.      (line   18)
* Python Enhancement Proposals; PEP 586 <3>: Special forms.  (line  161)
* Python Enhancement Proposals; PEP 587: Python configuration C API.
                                                             (line   10)
* Python Enhancement Proposals; PEP 587 <1>: Python configuration C API.
                                                             (line   17)
* Python Enhancement Proposals; PEP 587 <2>: Python configuration C API.
                                                             (line   34)
* Python Enhancement Proposals; PEP 587 <3>: Removed C APIs. (line   15)
* Python Enhancement Proposals; PEP 587 <4>: Removed C APIs<2>.
                                                             (line  104)
* Python Enhancement Proposals; PEP 587 <5>: Deprecated<3>.  (line   34)
* Python Enhancement Proposals; PEP 587 <6>: PEP 587 Python Initialization Configuration.
                                                             (line    6)
* Python Enhancement Proposals; PEP 587 <7>: PEP 587 Python Initialization Configuration.
                                                             (line   83)
* Python Enhancement Proposals; PEP 587 <8>: C API<11>.      (line   31)
* Python Enhancement Proposals; PEP 587 <9>: C API<37>.      (line  125)
* Python Enhancement Proposals; PEP 587 <10>: Core and Builtins<153>.
                                                             (line   76)
* Python Enhancement Proposals; PEP 587 <11>: C API<53>.     (line    6)
* Python Enhancement Proposals; PEP 587 <12>: PyConfig C API.
                                                             (line   32)
* Python Enhancement Proposals; PEP 589: typing<9>.          (line    8)
* Python Enhancement Proposals; PEP 590: Removed C APIs<2>.  (line  135)
* Python Enhancement Proposals; PEP 590 <1>: Porting to Python 3 11<2>.
                                                             (line   98)
* Python Enhancement Proposals; PEP 590 <2>: Optimizations<4>.
                                                             (line   55)
* Python Enhancement Proposals; PEP 590 <3>: Summary – Release highlights<4>.
                                                             (line   33)
* Python Enhancement Proposals; PEP 590 <4>: Optimizations<5>.
                                                             (line   37)
* Python Enhancement Proposals; PEP 590 <5>: PEP 590 Vectorcall a fast calling protocol for CPython.
                                                             (line   14)
* Python Enhancement Proposals; PEP 590 <6>: Core and Builtins<49>.
                                                             (line  145)
* Python Enhancement Proposals; PEP 590 <7>: Library<63>.    (line 1079)
* Python Enhancement Proposals; PEP 590 <8>: C API<22>.      (line  146)
* Python Enhancement Proposals; PEP 590 <9>: Core and Builtins<71>.
                                                             (line  113)
* Python Enhancement Proposals; PEP 590 <10>: Library<91>.   (line   69)
* Python Enhancement Proposals; PEP 590 <11>: Core and Builtins<93>.
                                                             (line   57)
* Python Enhancement Proposals; PEP 590 <12>: Core and Builtins<102>.
                                                             (line  118)
* Python Enhancement Proposals; PEP 590 <13>: Core and Builtins<111>.
                                                             (line    7)
* Python Enhancement Proposals; PEP 590 <14>: Core and Builtins<117>.
                                                             (line   12)
* Python Enhancement Proposals; PEP 590 <15>: Core and Builtins<117>.
                                                             (line   59)
* Python Enhancement Proposals; PEP 590 <16>: Core and Builtins<132>.
                                                             (line   10)
* Python Enhancement Proposals; PEP 590 <17>: Core and Builtins<132>.
                                                             (line   16)
* Python Enhancement Proposals; PEP 590 <18>: Core and Builtins<148>.
                                                             (line   39)
* Python Enhancement Proposals; PEP 590 <19>: Core and Builtins<148>.
                                                             (line   91)
* Python Enhancement Proposals; PEP 590 <20>: Core and Builtins<149>.
                                                             (line   42)
* Python Enhancement Proposals; PEP 590 <21>: Core and Builtins<149>.
                                                             (line   50)
* Python Enhancement Proposals; PEP 590 <22>: Core and Builtins<149>.
                                                             (line   67)
* Python Enhancement Proposals; PEP 590 <23>: C API<53>.     (line   17)
* Python Enhancement Proposals; PEP 590 <24>: The Vectorcall Protocol.
                                                             (line    8)
* Python Enhancement Proposals; PEP 591: typing<9>.          (line   25)
* Python Enhancement Proposals; PEP 591 <1>: Special forms.  (line  249)
* Python Enhancement Proposals; PEP 591 <2>: Functions and decorators.
                                                             (line  335)
* Python Enhancement Proposals; PEP 593: Summary – Release highlights<4>.
                                                             (line   20)
* Python Enhancement Proposals; PEP 593 <1>: typing<7>.      (line    6)
* Python Enhancement Proposals; PEP 593 <2>: Library<153>.   (line   91)
* Python Enhancement Proposals; PEP 593 <3>: Special forms.  (line  438)
* Python Enhancement Proposals; PEP 593 <4>: Introspection helpers.
                                                             (line   56)
* Python Enhancement Proposals; PEP 594: Summary – Release Highlights.
                                                             (line   21)
* Python Enhancement Proposals; PEP 594 <1>: PEP 594 Remove «dead batteries» from the standard library.
                                                             (line    6)
* Python Enhancement Proposals; PEP 594 <2>: Pending removal in Python 3 13.
                                                             (line    6)
* Python Enhancement Proposals; PEP 594 <3>: asynchat e asyncore.
                                                             (line    6)
* Python Enhancement Proposals; PEP 594 <4>: smtpd.          (line    6)
* Python Enhancement Proposals; PEP 594 <5>: Summary – Release highlights<2>.
                                                             (line   46)
* Python Enhancement Proposals; PEP 594 <6>: Modules.        (line    6)
* Python Enhancement Proposals; PEP 594 <7>: Library<63>.    (line  845)
* Python Enhancement Proposals; PEP 594 <8>: Library<63>.    (line  848)
* Python Enhancement Proposals; PEP 594 <9>: Library<63>.    (line  851)
* Python Enhancement Proposals; PEP 594 <10>: Library<63>.   (line  859)
* Python Enhancement Proposals; PEP 594 <11>: Library<63>.   (line  863)
* Python Enhancement Proposals; PEP 594 <12>: Library<63>.   (line  869)
* Python Enhancement Proposals; PEP 594 <13>: Library<63>.   (line  872)
* Python Enhancement Proposals; PEP 594 <14>: Library<63>.   (line  887)
* Python Enhancement Proposals; PEP 594 <15>: Library<63>.   (line  890)
* Python Enhancement Proposals; PEP 594 <16>: Library<63>.   (line  897)
* Python Enhancement Proposals; PEP 594 <17>: Library<63>.   (line  900)
* Python Enhancement Proposals; PEP 594 <18>: Library<63>.   (line  903)
* Python Enhancement Proposals; PEP 594 <19>: Library<63>.   (line  906)
* Python Enhancement Proposals; PEP 594 <20>: Library<63>.   (line  909)
* Python Enhancement Proposals; PEP 594 <21>: Library<63>.   (line  964)
* Python Enhancement Proposals; PEP 594 <22>: Library<63>.   (line  967)
* Python Enhancement Proposals; PEP 594 <23>: Library<63>.   (line  970)
* Python Enhancement Proposals; PEP 594 <24>: Library<63>.   (line  973)
* Python Enhancement Proposals; PEP 594 <25>: Library<76>.   (line  105)
* Python Enhancement Proposals; PEP 594 <26>: Library<86>.   (line  681)
* Python Enhancement Proposals; PEP 594 <27>: Library<88>.   (line   94)
* Python Enhancement Proposals; PEP 594 <28>: Library<91>.   (line  124)
* Python Enhancement Proposals; PEP 594 <29>: Library<91>.   (line  150)
* Python Enhancement Proposals; PEP 594 <30>: Tests<29>.     (line   25)
* Python Enhancement Proposals; PEP 594 <31>: Superseded Modules.
                                                             (line   21)
* Python Enhancement Proposals; PEP 594 <32>: aifc — Read and write AIFF and AIFC files.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <33>: asynchat — Asynchronous socket command/response handler.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <34>: asyncore — Asynchronous socket handler.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <35>: audioop — Manipulate raw audio data.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <36>: cgi — Common Gateway Interface support.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <37>: cgitb — Traceback manager for CGI scripts.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <38>: chunk — Read IFF chunked data.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <39>: crypt — Function to check Unix passwords.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <40>: imghdr — Determine the type of an image.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <41>: mailcap — Mailcap file handling.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <42>: msilib — Read and write Microsoft Installer files.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <43>: nis — Interface to Sun’s NIS Yellow Pages.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <44>: nntplib — NNTP protocol client.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <45>: ossaudiodev — Access to OSS-compatible audio devices.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <46>: pipes — Interface to shell pipelines.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <47>: smtpd — SMTP Server.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <48>: sndhdr — Determine type of sound file.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <49>: spwd — The shadow password database.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <50>: sunau — Read and write Sun AU files.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <51>: telnetlib — Telnet client.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <52>: uu — Encode and decode uuencode files.
                                                             (line   10)
* Python Enhancement Proposals; PEP 594 <53>: xdrlib — Encode and decode XDR data.
                                                             (line   10)
* Python Enhancement Proposals; PEP 596: What’s New In Python 3 9.
                                                             (line   16)
* Python Enhancement Proposals; PEP 597: Summary – Release highlights<3>.
                                                             (line   46)
* Python Enhancement Proposals; PEP 597 <1>: Library<120>.   (line   44)
* Python Enhancement Proposals; PEP 597 <2>: Opt-in EncodingWarning.
                                                             (line    6)
* Python Enhancement Proposals; PEP 602: Summary – Release Highlights.
                                                             (line  164)
* Python Enhancement Proposals; PEP 602 <1>: Summary – Release highlights<4>.
                                                             (line   58)
* Python Enhancement Proposals; PEP 602 <2>: How stable is Python?.
                                                             (line    8)
* Python Enhancement Proposals; PEP 604: Summary – Release highlights<3>.
                                                             (line   27)
* Python Enhancement Proposals; PEP 604 <1>: PEP 604 New Type Union Operator.
                                                             (line   28)
* Python Enhancement Proposals; PEP 604 <2>: Library<128>.   (line   25)
* Python Enhancement Proposals; PEP 604 <3>: Documentation<43>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 604 <4>: Tipo Unione.    (line  107)
* Python Enhancement Proposals; PEP 604 <5>: Manually Un-Stringizing Stringized Annotations.
                                                             (line   42)
* Python Enhancement Proposals; PEP 610: Distributions.      (line   49)
* Python Enhancement Proposals; PEP 612: Summary – Release highlights<3>.
                                                             (line   29)
* Python Enhancement Proposals; PEP 612 <1>: PEP 612 Parameter Specification Variables.
                                                             (line   25)
* Python Enhancement Proposals; PEP 612 <2>: Library<115>.   (line  691)
* Python Enhancement Proposals; PEP 612 <3>: Library<118>.   (line   95)
* Python Enhancement Proposals; PEP 612 <4>: Library<127>.   (line   17)
* Python Enhancement Proposals; PEP 612 <5>: Library<128>.   (line   25)
* Python Enhancement Proposals; PEP 612 <6>: Library<128>.   (line  119)
* Python Enhancement Proposals; PEP 612 <7>: Annotating callable objects.
                                                             (line   77)
* Python Enhancement Proposals; PEP 612 <8>: User-defined generic types.
                                                             (line  180)
* Python Enhancement Proposals; PEP 612 <9>: Special forms.  (line  132)
* Python Enhancement Proposals; PEP 612 <10>: Building generic types and type aliases.
                                                             (line  524)
* Python Enhancement Proposals; PEP 612 <11>: Aliases to other ABCs in collections abc.
                                                             (line   35)
* Python Enhancement Proposals; PEP 613: Summary – Release highlights<3>.
                                                             (line   31)
* Python Enhancement Proposals; PEP 613 <1>: PEP 613 TypeAlias.
                                                             (line   21)
* Python Enhancement Proposals; PEP 613 <2>: Library<134>.   (line   98)
* Python Enhancement Proposals; PEP 613 <3>: Special types.  (line  228)
* Python Enhancement Proposals; PEP 614: Summary – Release highlights<4>.
                                                             (line   12)
* Python Enhancement Proposals; PEP 614 <1>: Other Language Changes<4>.
                                                             (line   38)
* Python Enhancement Proposals; PEP 614 <2>: Core and Builtins<149>.
                                                             (line  112)
* Python Enhancement Proposals; PEP 614 <3>: Function definitions.
                                                             (line   57)
* Python Enhancement Proposals; PEP 614 <4>: Class definitions.
                                                             (line   60)
* Python Enhancement Proposals; PEP 615: Summary – Release highlights<4>.
                                                             (line   50)
* Python Enhancement Proposals; PEP 615 <1>: zoneinfo.       (line   37)
* Python Enhancement Proposals; PEP 615 <2>: Library<150>.   (line   54)
* Python Enhancement Proposals; PEP 615 <3>: zoneinfo — IANA time zone support.
                                                             (line   14)
* Python Enhancement Proposals; PEP 616: Summary – Release highlights<4>.
                                                             (line   16)
* Python Enhancement Proposals; PEP 616 <1>: New String Methods to Remove Prefixes and Suffixes.
                                                             (line    9)
* Python Enhancement Proposals; PEP 616 <2>: Core and Builtins<148>.
                                                             (line   82)
* Python Enhancement Proposals; PEP 617: PEP 701 Formalizzazione sintattica delle f-string.
                                                             (line   73)
* Python Enhancement Proposals; PEP 617 <1>: Modules.        (line   30)
* Python Enhancement Proposals; PEP 617 <2>: Parenthesized context managers.
                                                             (line   45)
* Python Enhancement Proposals; PEP 617 <3>: Summary – Release highlights<4>.
                                                             (line   30)
* Python Enhancement Proposals; PEP 617 <4>: New Parser.     (line   21)
* Python Enhancement Proposals; PEP 617 <5>: Deprecated<6>.  (line   95)
* Python Enhancement Proposals; PEP 617 <6>: Library<115>.   (line  178)
* Python Enhancement Proposals; PEP 617 <7>: Library<151>.   (line   34)
* Python Enhancement Proposals; PEP 617 <8>: Notation.       (line   49)
* Python Enhancement Proposals; PEP 618: Summary – Release highlights<3>.
                                                             (line   19)
* Python Enhancement Proposals; PEP 618 <1>: Other Language Changes<3>.
                                                             (line   17)
* Python Enhancement Proposals; PEP 618 <2>: Core and Builtins<143>.
                                                             (line   10)
* Python Enhancement Proposals; PEP 623: Sommario – Punti salienti del rilascio.
                                                             (line  114)
* Python Enhancement Proposals; PEP 623 <1>: Ottimizzazioni. (line    8)
* Python Enhancement Proposals; PEP 623 <2>: Rimosso<2>.     (line   11)
* Python Enhancement Proposals; PEP 623 <3>: Summary – Release highlights<3>.
                                                             (line   41)
* Python Enhancement Proposals; PEP 623 <4>: C API<30>.      (line   21)
* Python Enhancement Proposals; PEP 623 <5>: Core and Builtins<118>.
                                                             (line   10)
* Python Enhancement Proposals; PEP 623 <6>: Documentation<38>.
                                                             (line   10)
* Python Enhancement Proposals; PEP 623 <7>: Unicode Objects.
                                                             (line   17)
* Python Enhancement Proposals; PEP 624: Summary – Release highlights<2>.
                                                             (line   49)
* Python Enhancement Proposals; PEP 624 <1>: Removed<3>.     (line   97)
* Python Enhancement Proposals; PEP 624 <2>: Summary – Release highlights<3>.
                                                             (line   44)
* Python Enhancement Proposals; PEP 624 <3>: C API<37>.      (line  143)
* Python Enhancement Proposals; PEP 624#alternative-apis: Removed<3>.
                                                             (line   97)
* Python Enhancement Proposals; PEP 626: Pending removal in Python 3 15.
                                                             (line   77)
* Python Enhancement Proposals; PEP 626 <1>: Pending removal in Python 3 15<3>.
                                                             (line   77)
* Python Enhancement Proposals; PEP 626 <2>: Deprecato.      (line  231)
* Python Enhancement Proposals; PEP 626 <3>: Pending removal in Python 3 15<5>.
                                                             (line   77)
* Python Enhancement Proposals; PEP 626 <4>: Summary – Release highlights<3>.
                                                             (line   23)
* Python Enhancement Proposals; PEP 626 <5>: Core and Builtins<79>.
                                                             (line   45)
* Python Enhancement Proposals; PEP 626 <6>: Methods on code objects.
                                                             (line   81)
* Python Enhancement Proposals; PEP 626 <7>: Analysis functions.
                                                             (line  183)
* Python Enhancement Proposals; PEP 626 <8>: Pending removal in Python 3 15<7>.
                                                             (line   77)
* Python Enhancement Proposals; PEP 628: cmath.              (line    7)
* Python Enhancement Proposals; PEP 628 <1>: math<7>.        (line    7)
* Python Enhancement Proposals; PEP 628 <2>: Library<185>.   (line   32)
* Python Enhancement Proposals; PEP 630: C API<15>.          (line   24)
* Python Enhancement Proposals; PEP 630#type-checking: New features in the C API.
                                                             (line  141)
* Python Enhancement Proposals; PEP 632: Sommario – Punti salienti del rilascio.
                                                             (line  118)
* Python Enhancement Proposals; PEP 632 <1>: distutils.      (line    7)
* Python Enhancement Proposals; PEP 632 <2>: Summary – Release highlights<3>.
                                                             (line   39)
* Python Enhancement Proposals; PEP 632 <3>: distutils<2>.   (line   14)
* Python Enhancement Proposals; PEP 632 <4>: Library<76>.    (line   41)
* Python Enhancement Proposals; PEP 632 <5>: distutils — Building and installing Python modules.
                                                             (line   10)
* Python Enhancement Proposals; PEP 634: Summary – Release highlights<3>.
                                                             (line    8)
* Python Enhancement Proposals; PEP 634 <1>: Other Key Features.
                                                             (line   53)
* Python Enhancement Proposals; PEP 634 <2>: Core and Builtins<83>.
                                                             (line   55)
* Python Enhancement Proposals; PEP 634 <3>: Core and Builtins<114>.
                                                             (line   20)
* Python Enhancement Proposals; PEP 634 <4>: Core and Builtins<119>.
                                                             (line   16)
* Python Enhancement Proposals; PEP 634 <5>: Customizing positional arguments in class pattern matching.
                                                             (line   32)
* Python Enhancement Proposals; PEP 634 <6>: The match statement.
                                                             (line   33)
* Python Enhancement Proposals; PEP 634 <7>: Class Patterns. (line  136)
* Python Enhancement Proposals; PEP 634 <8>: PyTypeObject Slots.
                                                             (line  928)
* Python Enhancement Proposals; PEP 634 <9>: PyTypeObject Slots.
                                                             (line  952)
* Python Enhancement Proposals; PEP 635: Summary – Release highlights<3>.
                                                             (line   10)
* Python Enhancement Proposals; PEP 635 <1>: Other Key Features.
                                                             (line   54)
* Python Enhancement Proposals; PEP 636: Summary – Release highlights<3>.
                                                             (line   12)
* Python Enhancement Proposals; PEP 636 <1>: Other Key Features.
                                                             (line   54)
* Python Enhancement Proposals; PEP 636 <2>: Istruzioni match.
                                                             (line  186)
* Python Enhancement Proposals; PEP 636 <3>: The match statement.
                                                             (line   35)
* Python Enhancement Proposals; PEP 636 <4>: Class Patterns. (line  138)
* Python Enhancement Proposals; PEP 644: hashlib.            (line    8)
* Python Enhancement Proposals; PEP 644 <1>: Summary – Release highlights<3>.
                                                             (line   37)
* Python Enhancement Proposals; PEP 644 <2>: hashlib<3>.     (line    7)
* Python Enhancement Proposals; PEP 644 <3>: ssl<4>.         (line    7)
* Python Enhancement Proposals; PEP 644 <4>: Build Changes<3>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 644 <5>: Core and Builtins<56>.
                                                             (line  167)
* Python Enhancement Proposals; PEP 644 <6>: Library<86>.    (line  523)
* Python Enhancement Proposals; PEP 644 <7>: Build<43>.      (line    9)
* Python Enhancement Proposals; PEP 644 <8>: ssl — TLS/SSL wrapper for socket objects.
                                                             (line   61)
* Python Enhancement Proposals; PEP 646: PEP 646 Variadic generics.
                                                             (line    7)
* Python Enhancement Proposals; PEP 646 <1>: PEP 646 Variadic generics.
                                                             (line   18)
* Python Enhancement Proposals; PEP 646 <2>: Library<4>.     (line  251)
* Python Enhancement Proposals; PEP 646 <3>: Subscriptions.  (line   30)
* Python Enhancement Proposals; PEP 646 <4>: Expression lists.
                                                             (line   27)
* Python Enhancement Proposals; PEP 646 <5>: Function definitions.
                                                             (line  122)
* Python Enhancement Proposals; PEP 646 <6>: Building generic types and type aliases.
                                                             (line  356)
* Python Enhancement Proposals; PEP 647: Summary – Release highlights<3>.
                                                             (line   33)
* Python Enhancement Proposals; PEP 647 <1>: PEP 647 User-Defined Type Guards.
                                                             (line    9)
* Python Enhancement Proposals; PEP 647 <2>: Library<118>.   (line  182)
* Python Enhancement Proposals; PEP 647 <3>: Special forms.  (line  552)
* Python Enhancement Proposals; PEP 649: Summary – Release highlights.
                                                             (line   32)
* Python Enhancement Proposals; PEP 649 <1>: PEP 649 & PEP 749 Deferred evaluation of annotations.
                                                             (line    3)
* Python Enhancement Proposals; PEP 649 <2>: PEP 649 & PEP 749 Deferred evaluation of annotations.
                                                             (line   41)
* Python Enhancement Proposals; PEP 649 <3>: PEP 649 & PEP 749 Deferred evaluation of annotations.
                                                             (line   47)
* Python Enhancement Proposals; PEP 649 <4>: typing.         (line   28)
* Python Enhancement Proposals; PEP 649 <5>: Changes in annotations PEP 649 and PEP 749.
                                                             (line    6)
* Python Enhancement Proposals; PEP 649 <6>: Library<45>.    (line  791)
* Python Enhancement Proposals; PEP 649 <7>: Core and Builtins<46>.
                                                             (line   63)
* Python Enhancement Proposals; PEP 649 <8>: Core and Builtins<46>.
                                                             (line  115)
* Python Enhancement Proposals; PEP 649 <9>: Core and Builtins<46>.
                                                             (line  134)
* Python Enhancement Proposals; PEP 649 <10>: Special writable attributes.
                                                             (line   52)
* Python Enhancement Proposals; PEP 649 <11>: Other writable attributes on module objects.
                                                             (line   21)
* Python Enhancement Proposals; PEP 649 <12>: Special attributes.
                                                             (line   69)
* Python Enhancement Proposals; PEP 649 <13>: Annotations.   (line   48)
* Python Enhancement Proposals; PEP 649 <14>: Annotation scopes.
                                                             (line   63)
* Python Enhancement Proposals; PEP 649 <15>: Constant.      (line   15)
* Python Enhancement Proposals; PEP 649 <16>: Module Contents<5>.
                                                             (line  131)
* Python Enhancement Proposals; PEP 649 <17>: Module Contents<5>.
                                                             (line   49)
* Python Enhancement Proposals; PEP 649 <18>: annotationlib — Functionality for introspecting annotations.
                                                             (line   56)
* Python Enhancement Proposals; PEP 649 <19>: annotationlib — Functionality for introspecting annotations.
                                                             (line   59)
* Python Enhancement Proposals; PEP 649 <20>: Annotation semantics.
                                                             (line   18)
* Python Enhancement Proposals; PEP 649 <21>: Annotation semantics.
                                                             (line   57)
* Python Enhancement Proposals; PEP 649 <22>: Glossary.      (line   58)
* Python Enhancement Proposals; PEP 649#the-stringizer-and-the-fake-globals-environment: Functions<11>.
                                                             (line   50)
* Python Enhancement Proposals; PEP 652: PEP 652 Maintaining the Stable ABI.
                                                             (line   11)
* Python Enhancement Proposals; PEP 652 <1>: C API<38>.      (line   41)
* Python Enhancement Proposals; PEP 654: PEP 654 Exception Groups and except*.
                                                             (line    6)
* Python Enhancement Proposals; PEP 654 <1>: PEP 654 Exception Groups and except*.
                                                             (line   13)
* Python Enhancement Proposals; PEP 654 <2>: New opcodes.    (line   18)
* Python Enhancement Proposals; PEP 654 <3>: Core and Builtins<76>.
                                                             (line   23)
* Python Enhancement Proposals; PEP 654 <4>: Core and Builtins<99>.
                                                             (line   20)
* Python Enhancement Proposals; PEP 654 <5>: Core and Builtins<102>.
                                                             (line   88)
* Python Enhancement Proposals; PEP 655: PEP 655 Marking individual TypedDict items as required or not-required.
                                                             (line   30)
* Python Enhancement Proposals; PEP 655 <1>: Library<88>.    (line  266)
* Python Enhancement Proposals; PEP 655 <2>: Special forms.  (line  263)
* Python Enhancement Proposals; PEP 655 <3>: Special forms.  (line  272)
* Python Enhancement Proposals; PEP 655 <4>: Other special directives.
                                                             (line  483)
* Python Enhancement Proposals; PEP 657: PEP 657 Fine-grained error locations in tracebacks.
                                                             (line   55)
* Python Enhancement Proposals; PEP 657 <1>: inspect<3>.     (line   17)
* Python Enhancement Proposals; PEP 657 <2>: Library<88>.    (line  223)
* Python Enhancement Proposals; PEP 657 <3>: Core and Builtins<110>.
                                                             (line   11)
* Python Enhancement Proposals; PEP 659: Free-threaded mode improvements.
                                                             (line   10)
* Python Enhancement Proposals; PEP 659 <1>: PEP 659 Specializing Adaptive Interpreter.
                                                             (line    6)
* Python Enhancement Proposals; PEP 659 <2>: PEP 659 Specializing Adaptive Interpreter.
                                                             (line   30)
* Python Enhancement Proposals; PEP 667: New deprecations.   (line  116)
* Python Enhancement Proposals; PEP 667 <1>: Summary – Release Highlights.
                                                             (line   40)
* Python Enhancement Proposals; PEP 667 <2>: Defined mutation semantics for locals.
                                                             (line    8)
* Python Enhancement Proposals; PEP 667 <3>: Defined mutation semantics for locals.
                                                             (line   41)
* Python Enhancement Proposals; PEP 667 <4>: Deprecated C APIs<2>.
                                                             (line   33)
* Python Enhancement Proposals; PEP 667 <5>: Changes in the Python API<2>.
                                                             (line   17)
* Python Enhancement Proposals; PEP 667 <6>: Changes in the Python API<2>.
                                                             (line   26)
* Python Enhancement Proposals; PEP 667 <7>: Changes in the Python API<2>.
                                                             (line   32)
* Python Enhancement Proposals; PEP 667 <8>: Funzioni Incorporate.
                                                             (line 1197)
* Python Enhancement Proposals; PEP 667 <9>: Command-line interface<8>.
                                                             (line   76)
* Python Enhancement Proposals; PEP 667 <10>: Reflection.    (line   44)
* Python Enhancement Proposals; PEP 667 <11>: Frame Objects. (line  141)
* Python Enhancement Proposals; PEP 667 <12>: Frame Locals Proxies.
                                                             (line   14)
* Python Enhancement Proposals; PEP 667 <13>: Legacy Local Variable APIs.
                                                             (line   45)
* Python Enhancement Proposals; PEP 669: Summary – Release Highlights.
                                                             (line  110)
* Python Enhancement Proposals; PEP 669 <1>: New Features<2>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 669 <2>: PEP 669 Monitoraggio a basso impatto per CPython.
                                                             (line    6)
* Python Enhancement Proposals; PEP 669 <3>: Core and Builtins<60>.
                                                             (line   68)
* Python Enhancement Proposals; PEP 670: Summary – Release highlights<2>.
                                                             (line   51)
* Python Enhancement Proposals; PEP 670 <1>: Porting to Python 3 11<2>.
                                                             (line   12)
* Python Enhancement Proposals; PEP 672: Non-ASCII characters in names.
                                                             (line   93)
* Python Enhancement Proposals; PEP 673: PEP 673 Self type.  (line   32)
* Python Enhancement Proposals; PEP 673 <1>: Library<95>.    (line  134)
* Python Enhancement Proposals; PEP 673 <2>: Special types.  (line  194)
* Python Enhancement Proposals; PEP 675: PEP 675 Arbitrary literal string type.
                                                             (line   32)
* Python Enhancement Proposals; PEP 675 <1>: Library<91>.    (line   59)
* Python Enhancement Proposals; PEP 675 <2>: Special types.  (line   95)
* Python Enhancement Proposals; PEP 676: Documentation<29>.  (line    8)
* Python Enhancement Proposals; PEP 678: Altre modifiche al Linguaggio.
                                                             (line   36)
* Python Enhancement Proposals; PEP 678 <1>: PEP 678 Exceptions can be enriched with notes.
                                                             (line   11)
* Python Enhancement Proposals; PEP 678 <2>: Core and Builtins<60>.
                                                             (line   48)
* Python Enhancement Proposals; PEP 678 <3>: Core and Builtins<62>.
                                                             (line   20)
* Python Enhancement Proposals; PEP 678 <4>: Core and Builtins<83>.
                                                             (line  118)
* Python Enhancement Proposals; PEP 680: Summary – Release highlights<2>.
                                                             (line   20)
* Python Enhancement Proposals; PEP 680 <1>: New Modules<2>. (line    6)
* Python Enhancement Proposals; PEP 680 <2>: Library<91>.    (line  205)
* Python Enhancement Proposals; PEP 681: PEP 681 Data class transforms.
                                                             (line   30)
* Python Enhancement Proposals; PEP 681 <1>: Library<88>.    (line  110)
* Python Enhancement Proposals; PEP 681 <2>: Functions and decorators.
                                                             (line  243)
* Python Enhancement Proposals; PEP 682: Other Language Changes<2>.
                                                             (line   49)
* Python Enhancement Proposals; PEP 682 <1>: Format Specification Mini-Language.
                                                             (line   97)
* Python Enhancement Proposals; PEP 683: Nuove Funzionalità<2>.
                                                             (line  158)
* Python Enhancement Proposals; PEP 683 <1>: Core and Builtins<59>.
                                                             (line   70)
* Python Enhancement Proposals; PEP 683 <2>: Reference Counting.
                                                             (line  131)
* Python Enhancement Proposals; PEP 683 <3>: Glossary.       (line  847)
* Python Enhancement Proposals; PEP 684: PEP 734 Multiple interpreters in the standard library.
                                                             (line   33)
* Python Enhancement Proposals; PEP 684 <1>: PEP 684 Un GIL per interprete.
                                                             (line    6)
* Python Enhancement Proposals; PEP 684 <2>: Nuove Funzionalità<2>.
                                                             (line  196)
* Python Enhancement Proposals; PEP 684 <3>: concurrent interpreters — Multiple interpreters in the same process.
                                                             (line   40)
* Python Enhancement Proposals; PEP 684 <4>: sys — System-specific parameters and functions.
                                                             (line 1175)
* Python Enhancement Proposals; PEP 684 <5>: High-level API. (line   21)
* Python Enhancement Proposals; PEP 684 <6>: A Per-Interpreter GIL.
                                                             (line   14)
* Python Enhancement Proposals; PEP 686: Python UTF-8 Mode.  (line   71)
* Python Enhancement Proposals; PEP 686 <1>: Text Encoding.  (line   32)
* Python Enhancement Proposals; PEP 687: Library<59>.        (line  137)
* Python Enhancement Proposals; PEP 687 <1>: Core and Builtins<58>.
                                                             (line  326)
* Python Enhancement Proposals; PEP 687 <2>: Library<66>.    (line  293)
* Python Enhancement Proposals; PEP 687 <3>: Library<66>.    (line  300)
* Python Enhancement Proposals; PEP 687 <4>: Library<66>.    (line  333)
* Python Enhancement Proposals; PEP 687 <5>: Library<66>.    (line  336)
* Python Enhancement Proposals; PEP 687 <6>: Library<66>.    (line  346)
* Python Enhancement Proposals; PEP 687 <7>: Library<66>.    (line  403)
* Python Enhancement Proposals; PEP 687 <8>: Library<68>.    (line    6)
* Python Enhancement Proposals; PEP 687 <9>: Library<69>.    (line  111)
* Python Enhancement Proposals; PEP 687 <10>: Library<69>.   (line  118)
* Python Enhancement Proposals; PEP 688: PEP 688 Rendere accessibile il protocollo buffer in Python.
                                                             (line    6)
* Python Enhancement Proposals; PEP 688 <1>: Core and Builtins<60>.
                                                             (line   76)
* Python Enhancement Proposals; PEP 688 <2>: Emulating buffer types.
                                                             (line   39)
* Python Enhancement Proposals; PEP 688 <3>: Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  199)
* Python Enhancement Proposals; PEP 688#current-options: Pending removal in Python 3 17.
                                                             (line   26)
* Python Enhancement Proposals; PEP 688#current-options <1>: Pending removal in Python 3 17.
                                                             (line   58)
* Python Enhancement Proposals; PEP 688#current-options <2>: Pending removal in Python 3 17<2>.
                                                             (line   26)
* Python Enhancement Proposals; PEP 688#current-options <3>: Pending removal in Python 3 17<2>.
                                                             (line   58)
* Python Enhancement Proposals; PEP 688#current-options <4>: Deprecato.
                                                             (line   71)
* Python Enhancement Proposals; PEP 688#current-options <5>: Pending removal in Python 3 17<3>.
                                                             (line   26)
* Python Enhancement Proposals; PEP 688#current-options <6>: Pending removal in Python 3 17<3>.
                                                             (line   58)
* Python Enhancement Proposals; PEP 688#current-options <7>: Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  113)
* Python Enhancement Proposals; PEP 688#current-options <8>: Aliases to container ABCs in collections abc.
                                                             (line   33)
* Python Enhancement Proposals; PEP 688#current-options <9>: Pending removal in Python 3 17<4>.
                                                             (line   26)
* Python Enhancement Proposals; PEP 688#current-options <10>: Pending removal in Python 3 17<4>.
                                                             (line   58)
* Python Enhancement Proposals; PEP 689: C API<25>.          (line   26)
* Python Enhancement Proposals; PEP 692: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa.
                                                             (line   10)
* Python Enhancement Proposals; PEP 692 <1>: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa.
                                                             (line   21)
* Python Enhancement Proposals; PEP 692 <2>: Library<66>.    (line  120)
* Python Enhancement Proposals; PEP 692 <3>: Documentation<20>.
                                                             (line   11)
* Python Enhancement Proposals; PEP 692 <4>: Special forms.  (line  632)
* Python Enhancement Proposals; PEP 693: Novità in Python 3 12.
                                                             (line   16)
* Python Enhancement Proposals; PEP 695: PEP 695 Sintassi dei Parametri di Tipo.
                                                             (line   10)
* Python Enhancement Proposals; PEP 695 <1>: PEP 695 Sintassi dei Parametri di Tipo.
                                                             (line   63)
* Python Enhancement Proposals; PEP 695 <2>: Modifiche al bytecode di CPython.
                                                             (line   42)
* Python Enhancement Proposals; PEP 695 <3>: Library<45>.    (line  814)
* Python Enhancement Proposals; PEP 695 <4>: Library<54>.    (line  123)
* Python Enhancement Proposals; PEP 695 <5>: Library<63>.    (line   95)
* Python Enhancement Proposals; PEP 695 <6>: Library<63>.    (line  661)
* Python Enhancement Proposals; PEP 695 <7>: Library<63>.    (line  856)
* Python Enhancement Proposals; PEP 695 <8>: Library<63>.    (line  949)
* Python Enhancement Proposals; PEP 695 <9>: Core and Builtins<59>.
                                                             (line   10)
* Python Enhancement Proposals; PEP 695 <10>: Core and Builtins<59>.
                                                             (line  105)
* Python Enhancement Proposals; PEP 695 <11>: Library<66>.   (line   10)
* Python Enhancement Proposals; PEP 695 <12>: Annotation scopes.
                                                             (line   57)
* Python Enhancement Proposals; PEP 695 <13>: The type statement.
                                                             (line   40)
* Python Enhancement Proposals; PEP 695 <14>: Special types. (line   60)
* Python Enhancement Proposals; PEP 695 <15>: Building generic types and type aliases.
                                                             (line  113)
* Python Enhancement Proposals; PEP 695 <16>: Building generic types and type aliases.
                                                             (line  248)
* Python Enhancement Proposals; PEP 695 <17>: Building generic types and type aliases.
                                                             (line  394)
* Python Enhancement Proposals; PEP 695 <18>: Building generic types and type aliases.
                                                             (line  513)
* Python Enhancement Proposals; PEP 695 <19>: Deprecation Timeline of Major Features.
                                                             (line   30)
* Python Enhancement Proposals; PEP 696: Summary – Release Highlights.
                                                             (line  115)
* Python Enhancement Proposals; PEP 696 <1>: Core and Builtins<49>.
                                                             (line  165)
* Python Enhancement Proposals; PEP 696 <2>: Annotation scopes.
                                                             (line   60)
* Python Enhancement Proposals; PEP 696 <3>: Type parameter lists.
                                                             (line    8)
* Python Enhancement Proposals; PEP 697: Nuove Funzionalità<2>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 697 <1>: Nuove Funzionalità<2>.
                                                             (line   35)
* Python Enhancement Proposals; PEP 697 <2>: C API<23>.      (line   38)
* Python Enhancement Proposals; PEP 698: PEP 698 Decoratore Override per tipizzazione statica.
                                                             (line   30)
* Python Enhancement Proposals; PEP 698 <1>: Library<69>.    (line  100)
* Python Enhancement Proposals; PEP 698 <2>: Functions and decorators.
                                                             (line  407)
* Python Enhancement Proposals; PEP 699: Pending removal in Python 3 14<2>.
                                                             (line    7)
* Python Enhancement Proposals; PEP 699 <1>: Deprecato<2>.   (line    6)
* Python Enhancement Proposals; PEP 699 <2>: Pending removal in Python 3 14<4>.
                                                             (line    7)
* Python Enhancement Proposals; PEP 699 <3>: C API<15>.      (line   15)
* Python Enhancement Proposals; PEP 699 <4>: Build<27>.      (line   15)
* Python Enhancement Proposals; PEP 7:   Build and C API Changes<2>.
                                                             (line    9)
* Python Enhancement Proposals; PEP 7 <1>: Build Requirements.
                                                             (line   28)
* Python Enhancement Proposals; PEP 7 <2>: Coding standards. (line    7)
* Python Enhancement Proposals; PEP 7 <3>: Useful macros.    (line  196)
* Python Enhancement Proposals; PEP 7 <4>: Useful macros.    (line  214)
* Python Enhancement Proposals; PEP 701: PEP 701 Formalizzazione sintattica delle f-string.
                                                             (line    6)
* Python Enhancement Proposals; PEP 701 <1>: PEP 701 Formalizzazione sintattica delle f-string.
                                                             (line   70)
* Python Enhancement Proposals; PEP 701 <2>: tokenize.       (line    6)
* Python Enhancement Proposals; PEP 701 <3>: Ottimizzazioni. (line   28)
* Python Enhancement Proposals; PEP 701 <4>: Modifiche nell’API di Python.
                                                             (line   81)
* Python Enhancement Proposals; PEP 701 <5>: Modifiche nell’API di Python.
                                                             (line   83)
* Python Enhancement Proposals; PEP 701 <6>: Modifiche nell’API di Python.
                                                             (line  105)
* Python Enhancement Proposals; PEP 701 <7>: f-strings.      (line  153)
* Python Enhancement Proposals; PEP 702: Summary – Release Highlights.
                                                             (line  119)
* Python Enhancement Proposals; PEP 702 <1>: warnings.       (line    6)
* Python Enhancement Proposals; PEP 702 <2>: Library<61>.    (line  469)
* Python Enhancement Proposals; PEP 702 <3>: Available Functions.
                                                             (line  187)
* Python Enhancement Proposals; PEP 703: Free-threaded mode improvements.
                                                             (line    6)
* Python Enhancement Proposals; PEP 703 <1>: New features in the C API.
                                                             (line  193)
* Python Enhancement Proposals; PEP 703 <2>: Summary – Release Highlights.
                                                             (line   10)
* Python Enhancement Proposals; PEP 703 <3>: Summary – Release Highlights.
                                                             (line   46)
* Python Enhancement Proposals; PEP 703 <4>: Free-threaded CPython.
                                                             (line   54)
* Python Enhancement Proposals; PEP 703 <5>: C API<14>.      (line   21)
* Python Enhancement Proposals; PEP 703 <6>: Core and Builtins<46>.
                                                             (line  169)
* Python Enhancement Proposals; PEP 703 <7>: Core and Builtins<52>.
                                                             (line   11)
* Python Enhancement Proposals; PEP 703 <8>: C API<21>.      (line  137)
* Python Enhancement Proposals; PEP 703 <9>: Installing free-threaded binaries<2>.
                                                             (line    8)
* Python Enhancement Proposals; PEP 703 <10>: Installing Free-threaded Binaries.
                                                             (line    9)
* Python Enhancement Proposals; PEP 703 <11>: GIL and performance considerations.
                                                             (line   16)
* Python Enhancement Proposals; PEP 703 <12>: Python support for free threading.
                                                             (line   26)
* Python Enhancement Proposals; PEP 703 <13>: Can’t we get rid of the Global Interpreter Lock?.
                                                             (line   12)
* Python Enhancement Proposals; PEP 703 <14>: Glossary.      (line  661)
* Python Enhancement Proposals; PEP 703 <15>: Glossary.      (line  797)
* Python Enhancement Proposals; PEP 705: Summary – Release Highlights.
                                                             (line  123)
* Python Enhancement Proposals; PEP 705 <1>: typing<2>.      (line    6)
* Python Enhancement Proposals; PEP 705 <2>: Library<59>.    (line   17)
* Python Enhancement Proposals; PEP 705 <3>: Special forms.  (line  293)
* Python Enhancement Proposals; PEP 706: Altre modifiche al Linguaggio.
                                                             (line   84)
* Python Enhancement Proposals; PEP 706 <1>: tarfile<2>.     (line   13)
* Python Enhancement Proposals; PEP 706 <2>: tarfile<3>.     (line   13)
* Python Enhancement Proposals; PEP 706 <3>: tarfile<4>.     (line   13)
* Python Enhancement Proposals; PEP 706 <4>: tarfile<6>.     (line   13)
* Python Enhancement Proposals; PEP 706 <5>: Extraction filters.
                                                             (line   27)
* Python Enhancement Proposals; PEP 709: Changes in the Python API<2>.
                                                             (line   26)
* Python Enhancement Proposals; PEP 709 <1>: PEP 709 Inlining delle comprehension.
                                                             (line    9)
* Python Enhancement Proposals; PEP 709 <2>: PEP 709 Inlining delle comprehension.
                                                             (line   38)
* Python Enhancement Proposals; PEP 709 <3>: Modifiche al bytecode di CPython.
                                                             (line   34)
* Python Enhancement Proposals; PEP 709 <4>: Core and Builtins<60>.
                                                             (line   78)
* Python Enhancement Proposals; PEP 709 <5>: Funzioni Incorporate.
                                                             (line 1195)
* Python Enhancement Proposals; PEP 719: What’s New In Python 3 13.
                                                             (line   16)
* Python Enhancement Proposals; PEP 730: Summary – Release Highlights.
                                                             (line  133)
* Python Enhancement Proposals; PEP 730 <1>: Support for mobile platforms.
                                                             (line    6)
* Python Enhancement Proposals; PEP 730 <2>: Support for mobile platforms.
                                                             (line   25)
* Python Enhancement Proposals; PEP 734: Summary – Release highlights.
                                                             (line   35)
* Python Enhancement Proposals; PEP 734 <1>: PEP 734 Multiple interpreters in the standard library.
                                                             (line    3)
* Python Enhancement Proposals; PEP 734 <2>: PEP 734 Multiple interpreters in the standard library.
                                                             (line   97)
* Python Enhancement Proposals; PEP 734 <3>: Library<18>.    (line   44)
* Python Enhancement Proposals; PEP 734 <4>: Library<41>.    (line  348)
* Python Enhancement Proposals; PEP 734 <5>: Library<54>.    (line  161)
* Python Enhancement Proposals; PEP 734 <6>: InterpreterPoolExecutor.
                                                             (line   50)
* Python Enhancement Proposals; PEP 734 <7>: concurrent interpreters — Multiple interpreters in the same process.
                                                             (line   38)
* Python Enhancement Proposals; PEP 734 <8>: sys — System-specific parameters and functions.
                                                             (line 1175)
* Python Enhancement Proposals; PEP 737: Changed C APIs.     (line   44)
* Python Enhancement Proposals; PEP 737 <1>: C API<17>.      (line    6)
* Python Enhancement Proposals; PEP 737 <2>: C API<17>.      (line   49)
* Python Enhancement Proposals; PEP 738: Summary – Release Highlights.
                                                             (line  136)
* Python Enhancement Proposals; PEP 738 <1>: Support for mobile platforms.
                                                             (line   15)
* Python Enhancement Proposals; PEP 738 <2>: Support for mobile platforms.
                                                             (line   25)
* Python Enhancement Proposals; PEP 738 <3>: Library<54>.    (line   54)
* Python Enhancement Proposals; PEP 739: build-details json. (line   19)
* Python Enhancement Proposals; PEP 739 <1>: Build<6>.       (line   21)
* Python Enhancement Proposals; PEP 739 <2>: Build<7>.       (line    7)
* Python Enhancement Proposals; PEP 739 <3>: Core and Builtins<26>.
                                                             (line  101)
* Python Enhancement Proposals; PEP 741: Summary – Release highlights.
                                                             (line   69)
* Python Enhancement Proposals; PEP 741 <1>: Python configuration C API.
                                                             (line   34)
* Python Enhancement Proposals; PEP 741 <2>: C API<11>.      (line   27)
* Python Enhancement Proposals; PEP 741 <3>: C API<15>.      (line   39)
* Python Enhancement Proposals; PEP 741 <4>: PyInitConfig C API.
                                                             (line   18)
* Python Enhancement Proposals; PEP 742: Summary – Release Highlights.
                                                             (line  127)
* Python Enhancement Proposals; PEP 742 <1>: typing<2>.      (line    9)
* Python Enhancement Proposals; PEP 742 <2>: Library<54>.    (line  239)
* Python Enhancement Proposals; PEP 742 <3>: Special forms.  (line  530)
* Python Enhancement Proposals; PEP 744: Binary releases for the experimental just-in-time compiler.
                                                             (line   34)
* Python Enhancement Proposals; PEP 744 <1>: Summary – Release Highlights.
                                                             (line   11)
* Python Enhancement Proposals; PEP 744 <2>: Summary – Release Highlights.
                                                             (line   50)
* Python Enhancement Proposals; PEP 744 <3>: An experimental just-in-time JIT compiler.
                                                             (line   60)
* Python Enhancement Proposals; PEP 745: What’s new in Python 3 14.
                                                             (line   16)
* Python Enhancement Proposals; PEP 749: Summary – Release highlights.
                                                             (line   32)
* Python Enhancement Proposals; PEP 749 <1>: PEP 649 & PEP 749 Deferred evaluation of annotations.
                                                             (line    3)
* Python Enhancement Proposals; PEP 749 <2>: PEP 649 & PEP 749 Deferred evaluation of annotations.
                                                             (line   41)
* Python Enhancement Proposals; PEP 749 <3>: PEP 649 & PEP 749 Deferred evaluation of annotations.
                                                             (line   51)
* Python Enhancement Proposals; PEP 749 <4>: Changes in annotations PEP 649 and PEP 749.
                                                             (line    6)
* Python Enhancement Proposals; PEP 749 <5>: Library<45>.    (line  528)
* Python Enhancement Proposals; PEP 749 <6>: Library<45>.    (line  791)
* Python Enhancement Proposals; PEP 749 <7>: Annotation scopes.
                                                             (line   63)
* Python Enhancement Proposals; PEP 749 <8>: Annotations<2>. (line   42)
* Python Enhancement Proposals; PEP 749 <9>: Module Contents<5>.
                                                             (line  131)
* Python Enhancement Proposals; PEP 749 <10>: annotationlib — Functionality for introspecting annotations.
                                                             (line   59)
* Python Enhancement Proposals; PEP 749 <11>: Annotation semantics.
                                                             (line   19)
* Python Enhancement Proposals; PEP 749#pep749-metaclasses: Special attributes.
                                                             (line   60)
* Python Enhancement Proposals; PEP 749#pep749-metaclasses <1>: __annotations__ Quirks.
                                                             (line   40)
* Python Enhancement Proposals; PEP 750: Summary – Release highlights.
                                                             (line   38)
* Python Enhancement Proposals; PEP 750 <1>: PEP 750 Template string literals.
                                                             (line    3)
* Python Enhancement Proposals; PEP 750 <2>: PEP 750 Template string literals.
                                                             (line   72)
* Python Enhancement Proposals; PEP 750 <3>: Core and Builtins<13>.
                                                             (line   20)
* Python Enhancement Proposals; PEP 750 <4>: Library<22>.    (line  140)
* Python Enhancement Proposals; PEP 750 <5>: Core and Builtins<22>.
                                                             (line   43)
* Python Enhancement Proposals; PEP 750 <6>: string templatelib — Support for template string literals.
                                                             (line   17)
* Python Enhancement Proposals; PEP 757: New features in the C API.
                                                             (line  114)
* Python Enhancement Proposals; PEP 757 <1>: C API<11>.      (line   76)
* Python Enhancement Proposals; PEP 757 <2>: C API<13>.      (line   41)
* Python Enhancement Proposals; PEP 758: Summary – Release highlights.
                                                             (line   40)
* Python Enhancement Proposals; PEP 758 <1>: PEP 758 Allow except and except* expressions without brackets.
                                                             (line   15)
* Python Enhancement Proposals; PEP 758 <2>: Library<24>.    (line    6)
* Python Enhancement Proposals; PEP 758 <3>: Core and Builtins<24>.
                                                             (line   27)
* Python Enhancement Proposals; PEP 758 <4>: The try statement.
                                                             (line   27)
* Python Enhancement Proposals; PEP 761: Summary – Release highlights.
                                                             (line   81)
* Python Enhancement Proposals; PEP 761 <1>: Discontinuation of PGP signatures.
                                                             (line   11)
* Python Enhancement Proposals; PEP 765: Summary – Release highlights.
                                                             (line   43)
* Python Enhancement Proposals; PEP 765 <1>: PEP 765 Control flow in finally blocks.
                                                             (line    8)
* Python Enhancement Proposals; PEP 765 <2>: Core and Builtins<7>.
                                                             (line   62)
* Python Enhancement Proposals; PEP 765 <3>: Definizione di Azioni di Pulizia.
                                                             (line   41)
* Python Enhancement Proposals; PEP 765 <4>: Definizione di Azioni di Pulizia.
                                                             (line   53)
* Python Enhancement Proposals; PEP 765 <5>: finally clause. (line   47)
* Python Enhancement Proposals; PEP 768: Summary – Release highlights.
                                                             (line   45)
* Python Enhancement Proposals; PEP 768 <1>: PEP 768 Safe external debugger interface.
                                                             (line    3)
* Python Enhancement Proposals; PEP 768 <2>: PEP 768 Safe external debugger interface.
                                                             (line   53)
* Python Enhancement Proposals; PEP 768 <3>: Core and Builtins<18>.
                                                             (line    6)
* Python Enhancement Proposals; PEP 768 <4>: Core and Builtins<22>.
                                                             (line   36)
* Python Enhancement Proposals; PEP 768 <5>: Core and Builtins<24>.
                                                             (line   17)
* Python Enhancement Proposals; PEP 768 <6>: Miscellaneous options.
                                                             (line  383)
* Python Enhancement Proposals; PEP 768 <7>: Miscellaneous options.
                                                             (line  390)
* Python Enhancement Proposals; PEP 768 <8>: Environment variables.
                                                             (line  496)
* Python Enhancement Proposals; PEP 768 <9>: Performance options.
                                                             (line  150)
* Python Enhancement Proposals; PEP 768 <10>: Performance options.
                                                             (line  153)
* Python Enhancement Proposals; PEP 768 <11>: sys — System-specific parameters and functions.
                                                             (line 1959)
* Python Enhancement Proposals; PEP 776: Summary – Release highlights.
                                                             (line   73)
* Python Enhancement Proposals; PEP 776 <1>: Build changes.  (line    6)
* Python Enhancement Proposals; PEP 779: Summary – Release highlights.
                                                             (line   78)
* Python Enhancement Proposals; PEP 779 <1>: Free-threaded Python is officially supported.
                                                             (line   28)
* Python Enhancement Proposals; PEP 784: Summary – Release highlights.
                                                             (line   58)
* Python Enhancement Proposals; PEP 784 <1>: PEP 784 Zstandard support in the standard library.
                                                             (line    3)
* Python Enhancement Proposals; PEP 784 <2>: PEP 784 Zstandard support in the standard library.
                                                             (line   41)
* Python Enhancement Proposals; PEP 8:   Library Changes.    (line   26)
* Python Enhancement Proposals; PEP 8 <1>: Library<170>.     (line  124)
* Python Enhancement Proposals; PEP 8 <2>: IDLE<63>.         (line   81)
* Python Enhancement Proposals; PEP 8 <3>: Intermezzo Stile di Codifica.
                                                             (line   13)
* Python Enhancement Proposals; PEP 8 <4>: Editors and IDEs. (line    7)
* Python Enhancement Proposals; PEP 8 <5>: Value comparisons.
                                                             (line   61)
* Python Enhancement Proposals; PEP 8 <6>: Funzioni Incorporate.
                                                             (line 1920)
* Python Enhancement Proposals; PEP 8 <7>: Odds and Ends.    (line   35)
* Python Enhancement Proposals; PEP 8 <8>: Are there coding standards or a style guide for Python programs?.
                                                             (line    7)
* Python Enhancement Proposals; PEP 8 <9>: When can I rely on identity tests with the is operator?.
                                                             (line   59)
* Python Enhancement Proposals; PEP 8 <10>: How do I keep editors from inserting tabs into my Python source?.
                                                             (line    6)
* PYTHON_ABI_VERSION (C macro):          Creating extension modules dynamically.
                                                             (line   78)
* PYTHON_API_VERSION (C macro):          Creating extension modules dynamically.
                                                             (line   71)
* PYTHON_BASIC_REPL:                     Default interactive shell.
                                                             (line    7)
* PYTHON_BASIC_REPL <1>:                 A better interactive interpreter.
                                                             (line   27)
* PYTHON_BASIC_REPL <2>:                 Library<45>.        (line   52)
* PYTHON_BASIC_REPL <3>:                 Library<45>.        (line   56)
* PYTHON_BASIC_REPL <4>:                 Core and Builtins<46>.
                                                             (line   13)
* PYTHON_BASIC_REPL <5>:                 Modalità Interattiva<2>.
                                                             (line   24)
* PYTHON_BASIC_REPL <6>:                 Example.            (line   80)
* PYTHON_BASIC_REPL <7>:                 asyncio — Asynchronous I/O.
                                                             (line   81)
* python_branch() (nel modulo platform): Cross platform.     (line   88)
* python_build() (nel modulo platform):  Cross platform.     (line   78)
* PYTHON_COLORS:                         Summary – Release Highlights.
                                                             (line   57)
* PYTHON_COLORS <1>:                     Improved error messages<2>.
                                                             (line    8)
* PYTHON_COLORS <2>:                     doctest.            (line    7)
* PYTHON_COLORS <3>:                     Controlling color.  (line   22)
* PYTHON_COLORS <4>:                     color.              (line   24)
* python_compiler() (nel modulo platform): Cross platform.   (line   83)
* PYTHON_CONTEXT_AWARE_WARNINGS:         Library<23>.        (line  369)
* PYTHON_CONTEXT_AWARE_WARNINGS <1>:     Miscellaneous options.
                                                             (line  434)
* PYTHON_CONTEXT_AWARE_WARNINGS <2>:     sys — System-specific parameters and functions.
                                                             (line  601)
* PYTHON_CONTEXT_AWARE_WARNINGS <3>:     Concurrent safety of Context Managers.
                                                             (line   41)
* PYTHON_CPU_COUNT:                      os<2>.              (line   11)
* PYTHON_CPU_COUNT <1>:                  Miscellaneous options.
                                                             (line  398)
* PYTHON_CPU_COUNT <2>:                  Miscellaneous System Information.
                                                             (line   49)
* PYTHON_CPU_COUNT <3>:                  Miscellaneous System Information.
                                                             (line   69)
* PYTHON_CPU_COUNT <4>:                  Miscellaneous<4>.   (line   31)
* PYTHON_CPU_COUNT <5>:                  PyConfig.           (line  523)
* PYTHON_DISABLE_REMOTE_DEBUG:           PEP 768 Safe external debugger interface.
                                                             (line   40)
* PYTHON_DISABLE_REMOTE_DEBUG <1>:       Miscellaneous options.
                                                             (line  389)
* PYTHON_DISABLE_REMOTE_DEBUG <2>:       Disabling remote debugging.
                                                             (line    8)
* PYTHON_DOM:                            Module Contents<4>. (line   23)
* PYTHON_FROZEN_MODULES:                 Other Language Changes.
                                                             (line   46)
* PYTHON_FROZEN_MODULES <1>:             Core and Builtins<57>.
                                                             (line  105)
* PYTHON_FROZEN_MODULES <2>:             Miscellaneous options.
                                                             (line  357)
* PYTHON_FROZEN_MODULES <3>:             PyConfig.           (line  420)
* PYTHON_GIL:                            Free-threaded CPython.
                                                             (line   22)
* PYTHON_GIL <1>:                        Free-threaded CPython.
                                                             (line   38)
* PYTHON_GIL <2>:                        Core and Builtins<42>.
                                                             (line   50)
* PYTHON_GIL <3>:                        Miscellaneous options.
                                                             (line  416)
* PYTHON_GIL <4>:                        sys — System-specific parameters and functions.
                                                             (line  594)
* PYTHON_GIL <5>:                        The global interpreter lock in free-threaded Python.
                                                             (line    7)
* PYTHON_GIL <6>:                        Glossary.           (line  794)
* PYTHON_HISTORY:                        Other Language Changes.
                                                             (line   57)
* PYTHON_HISTORY <1>:                    Library<61>.        (line  544)
* python_implementation() (nel modulo platform): Cross platform.
                                                             (line   92)
* python_is_optimized() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  273)
* PYTHON_JIT:                            Binary releases for the experimental just-in-time compiler.
                                                             (line    8)
* PYTHON_JIT <1>:                        General Options.    (line  238)
* PYTHON_JIT <2>:                        General Options.    (line  241)
* PYTHON_JIT <3>:                        General Options.    (line  246)
* PYTHON_JIT <4>:                        sys — System-specific parameters and functions.
                                                             (line 1297)
* PYTHON_MANAGER_AUTOMATIC_INSTALL:      Installing runtimes.
                                                             (line   41)
* PYTHON_MANAGER_DEFAULT:                Basic use.          (line   46)
* PYTHON_MANAGER_DEFAULT <1>:            Troubleshooting.    (line   76)
* PYTHON_PERF_JIT_SUPPORT:               Other Language Changes.
                                                             (line   52)
* PYTHON_PERF_JIT_SUPPORT <1>:           Miscellaneous options.
                                                             (line  376)
* PYTHON_PERF_JIT_SUPPORT <2>:           PyConfig.           (line  908)
* PYTHON_PERF_JIT_SUPPORT <3>:           How to work without frame pointers.
                                                             (line   14)
* PYTHON_PRESITE:                        Miscellaneous options.
                                                             (line  410)
* PYTHON_PRESITE <1>:                    PyConfig.           (line  802)
* PYTHON_PRESITE=package.module:         Core and Builtins<57>.
                                                             (line  154)
* python_revision() (nel modulo platform): Cross platform.   (line   97)
* PYTHON_THREAD_INHERIT_CONTEXT:         Core and Builtins<23>.
                                                             (line  135)
* PYTHON_THREAD_INHERIT_CONTEXT <1>:     Miscellaneous options.
                                                             (line  426)
* PYTHON_THREAD_INHERIT_CONTEXT <2>:     sys — System-specific parameters and functions.
                                                             (line  597)
* PYTHON_TLBC:                           Miscellaneous options.
                                                             (line  442)
* python_version_tuple() (nel modulo platform): Cross platform.
                                                             (line  109)
* python_version() (nel modulo platform): Cross platform.    (line  102)
* python-m-py_compile command line option; -: Command-Line Interface<5>.
                                                             (line   13)
* python-m-py_compile command line option; -q: Command-Line Interface<5>.
                                                             (line   19)
* python-m-py_compile command line option; -quiet: Command-Line Interface<5>.
                                                             (line   19)
* python-m-py_compile command line option; <file>: Command-Line Interface<5>.
                                                             (line   13)
* python-m-sqlite3-[-h]-[-v]-[filename]-[sql] command line option; -h: Command-line interface<2>.
                                                             (line   14)
* python-m-sqlite3-[-h]-[-v]-[filename]-[sql] command line option; -help: Command-line interface<2>.
                                                             (line   14)
* python-m-sqlite3-[-h]-[-v]-[filename]-[sql] command line option; -v: Command-line interface<2>.
                                                             (line   18)
* python-m-sqlite3-[-h]-[-v]-[filename]-[sql] command line option; -version: Command-line interface<2>.
                                                             (line   18)
* PYTHONASYNCIODEBUG:                    Enabling debug mode.
                                                             (line   10)
* PYTHONASYNCIODEBUG <1>:                Debug Mode.         (line   11)
* PYTHONASYNCIODEBUG <2>:                Effects of the Python Development Mode.
                                                             (line   65)
* PYTHONBREAKPOINT:                      PEP 553 Built-in breakpoint.
                                                             (line   13)
* PYTHONBREAKPOINT <1>:                  Funzioni Incorporate.
                                                             (line  165)
* PYTHONBREAKPOINT <2>:                  sys — System-specific parameters and functions.
                                                             (line  256)
* PYTHONBREAKPOINT <3>:                  sys — System-specific parameters and functions.
                                                             (line  270)
* PYTHONBREAKPOINT <4>:                  sys — System-specific parameters and functions.
                                                             (line  274)
* PYTHONCASEOK:                          Changes in the Python API<4>.
                                                             (line   29)
* PYTHONCASEOK <1>:                      PEP 235 Importing Modules on Case-Insensitive Platforms.
                                                             (line   17)
* PYTHONCASEOK <2>:                      Library<152>.       (line  144)
* PYTHONCASEOK <3>:                      Funzioni Incorporate.
                                                             (line 2359)
* PYTHONCOERCECLOCALE:                   PEP 538 Legacy C Locale Coercion.
                                                             (line   13)
* PYTHONCOERCECLOCALE <1>:               General Options.    (line   88)
* PYTHONCOERCECLOCALE <2>:               Python UTF-8 Mode.  (line   57)
* PYTHONCOERCECLOCALE <3>:               Python Configuration.
                                                             (line   15)
* PYTHONDEBUG:                           Miscellaneous options.
                                                             (line   37)
* PYTHONDEBUG <1>:                       Python Debug Build. (line   20)
* PYTHONDEBUG <2>:                       Global configuration variables.
                                                             (line   38)
* PYTHONDEBUG <3>:                       PyConfig.           (line  693)
* PYTHONDEVMODE:                         Python Development Mode -X dev.
                                                             (line    6)
* PYTHONDEVMODE <1>:                     Miscellaneous options.
                                                             (line  316)
* PYTHONDEVMODE <2>:                     Python Development Mode.
                                                             (line   14)
* PYTHONDEVMODE <3>:                     PyConfig.           (line  296)
* PYTHONDONTWRITEBYTECODE:               Interpreter Changes<2>.
                                                             (line   16)
* PYTHONDONTWRITEBYTECODE <1>:           New and Improved Modules<2>.
                                                             (line  626)
* PYTHONDONTWRITEBYTECODE <2>:           Miscellaneous options.
                                                             (line   19)
* PYTHONDONTWRITEBYTECODE <3>:           sys — System-specific parameters and functions.
                                                             (line  340)
* PYTHONDONTWRITEBYTECODE <4>:           Global configuration variables.
                                                             (line   52)
* PYTHONDONTWRITEBYTECODE <5>:           PyConfig.           (line 1007)
* PYTHONDONTWRITEBYTECODE <6>:           How do I create a pyc file?.
                                                             (line   21)
* PYTHONDUMPREFS:                        Debug build uses the same ABI as release build.
                                                             (line   15)
* PYTHONDUMPREFS <1>:                    Build<59>.          (line   54)
* PYTHONDUMPREFS <2>:                    Debug options.      (line   22)
* PYTHONDUMPREFS <3>:                    Debug options.      (line   24)
* PYTHONDUMPREFS <4>:                    PyConfig.           (line  307)
* PYTHONDUMPREFSFILE:                    Core and Builtins<108>.
                                                             (line   16)
* PYTHONDUMPREFSFILE <1>:                PyConfig.           (line  319)
* PYTHONEXECUTABLE:                      PyConfig.           (line  728)
* PYTHONFAULTHANDLER:                    faulthandler<5>.    (line   12)
* PYTHONFAULTHANDLER <1>:                Miscellaneous options.
                                                             (line  268)
* PYTHONFAULTHANDLER <2>:                Effects of the Python Development Mode.
                                                             (line   59)
* PYTHONFAULTHANDLER <3>:                faulthandler — Dump the Python traceback.
                                                             (line   15)
* PYTHONFAULTHANDLER <4>:                PyConfig.           (line  356)
* PythonFinalizationError:               Concrete exceptions.
                                                             (line  226)
* PYTHONHASHSEED:                        Builtin functions and types.
                                                             (line   17)
* PYTHONHASHSEED <1>:                    Porting Python code.
                                                             (line    6)
* PYTHONHASHSEED <2>:                    Core and Builtins<165>.
                                                             (line   30)
* PYTHONHASHSEED <3>:                    Miscellaneous options.
                                                             (line  130)
* PYTHONHASHSEED <4>:                    Miscellaneous options.
                                                             (line  147)
* PYTHONHASHSEED <5>:                    Environment variables.
                                                             (line  157)
* PYTHONHASHSEED <6>:                    Basic customization.
                                                             (line  317)
* PYTHONHASHSEED <7>:                    Global configuration variables.
                                                             (line   77)
* PYTHONHASHSEED <8>:                    Global configuration variables.
                                                             (line   80)
* PYTHONHASHSEED <9>:                    PyConfig.           (line  436)
* PYTHONHOME:                            Pending removal in Python 3 15<2>.
                                                             (line   58)
* PYTHONHOME <1>:                        Deprecated C APIs<2>.
                                                             (line   26)
* PYTHONHOME <2>:                        Pending removal in Python 3 15<4>.
                                                             (line   58)
* PYTHONHOME <3>:                        Pending removal in Python 3 15<6>.
                                                             (line   58)
* PYTHONHOME <4>:                        Summary – Release highlights<6>.
                                                             (line  107)
* PYTHONHOME <5>:                        Miscellaneous options.
                                                             (line   46)
* PYTHONHOME <6>:                        Environment variables.
                                                             (line   19)
* PYTHONHOME <7>:                        Environment variables.
                                                             (line   21)
* PYTHONHOME <8>:                        Environment variables.
                                                             (line   38)
* PYTHONHOME <9>:                        Finding modules.    (line   29)
* PYTHONHOME <10>:                       Finding modules.    (line   47)
* PYTHONHOME <11>:                       Finding modules.    (line   81)
* PYTHONHOME <12>:                       Adding Python to an iOS project.
                                                             (line   87)
* PYTHONHOME <13>:                       test support script_helper — Utilities for the Python execution tests.
                                                             (line   25)
* PYTHONHOME <14>:                       The initialization of the sys path module search path.
                                                             (line   30)
* PYTHONHOME <15>:                       The initialization of the sys path module search path.
                                                             (line   56)
* PYTHONHOME <16>:                       Virtual Environments.
                                                             (line   19)
* PYTHONHOME <17>:                       Embedding Python<2>.
                                                             (line   38)
* PYTHONHOME <18>:                       Embedding Python<2>.
                                                             (line   44)
* PYTHONHOME <19>:                       Global configuration variables.
                                                             (line   92)
* PYTHONHOME <20>:                       Process-wide parameters.
                                                             (line  302)
* PYTHONHOME <21>:                       Process-wide parameters.
                                                             (line  318)
* PYTHONHOME <22>:                       Process-wide parameters.
                                                             (line  327)
* PYTHONHOME <23>:                       PyConfig.           (line  444)
* PYTHONHOME <24>:                       PyConfig.           (line  446)
* PYTHONHOME <25>:                       Pending removal in Python 3 15<8>.
                                                             (line   58)
* Pythonic:                              Glossary.           (line 1448)
* PYTHONINSPECT:                         Other Changes and Fixes<2>.
                                                             (line   13)
* PYTHONINSPECT <1>:                     Core and Builtins.  (line   57)
* PYTHONINSPECT <2>:                     Miscellaneous options.
                                                             (line   68)
* PYTHONINSPECT <3>:                     Global configuration variables.
                                                             (line  109)
* PYTHONINSPECT <4>:                     PyConfig.           (line  476)
* PYTHONINTMAXSTRDIGITS:                 Core and Builtins<74>.
                                                             (line   74)
* PYTHONINTMAXSTRDIGITS <1>:             Miscellaneous options.
                                                             (line  290)
* PYTHONINTMAXSTRDIGITS <2>:             Configurazione del limite.
                                                             (line   10)
* PYTHONINTMAXSTRDIGITS <3>:             Configurazione del limite.
                                                             (line   17)
* PYTHONINTMAXSTRDIGITS <4>:             sys — System-specific parameters and functions.
                                                             (line 1215)
* PYTHONINTMAXSTRDIGITS <5>:             PyConfig.           (line  507)
* PYTHONIOENCODING:                      Other Improvements<2>.
                                                             (line   75)
* PYTHONIOENCODING <1>:                  Interpreter Changes<2>.
                                                             (line   23)
* PYTHONIOENCODING <2>:                  Environment variables.
                                                             (line  408)
* PYTHONIOENCODING <3>:                  Python UTF-8 Mode.  (line   29)
* PYTHONIOENCODING <4>:                  sys — System-specific parameters and functions.
                                                             (line 2027)
* PYTHONIOENCODING <5>:                  PyConfig.           (line  862)
* PYTHONLEGACYWINDOWSFSENCODING:         Pending removal in Python 3 16.
                                                             (line  102)
* PYTHONLEGACYWINDOWSFSENCODING <1>:     New Deprecations.   (line  131)
* PYTHONLEGACYWINDOWSFSENCODING <2>:     Pending removal in Python 3 16<3>.
                                                             (line  102)
* PYTHONLEGACYWINDOWSFSENCODING <3>:     Pending removal in Python 3 16<5>.
                                                             (line  102)
* PYTHONLEGACYWINDOWSFSENCODING <4>:     PEP 529 Change Windows filesystem encoding to UTF-8.
                                                             (line   18)
* PYTHONLEGACYWINDOWSFSENCODING <5>:     Windows<18>.        (line   37)
* PYTHONLEGACYWINDOWSFSENCODING <6>:     sys — System-specific parameters and functions.
                                                             (line 1967)
* PYTHONLEGACYWINDOWSFSENCODING <7>:     sys — System-specific parameters and functions.
                                                             (line 1978)
* PYTHONLEGACYWINDOWSFSENCODING <8>:     sys — System-specific parameters and functions.
                                                             (line 1984)
* PYTHONLEGACYWINDOWSFSENCODING <9>:     Global configuration variables.
                                                             (line  151)
* PYTHONLEGACYWINDOWSFSENCODING <10>:    PyPreConfig.        (line  123)
* PYTHONLEGACYWINDOWSFSENCODING <11>:    Pending removal in Python 3 16<7>.
                                                             (line  102)
* PYTHONLEGACYWINDOWSSTDIO:              PEP 528 Change Windows console encoding to UTF-8.
                                                             (line   12)
* PYTHONLEGACYWINDOWSSTDIO <1>:          Environment variables.
                                                             (line  193)
* PYTHONLEGACYWINDOWSSTDIO <2>:          sys — System-specific parameters and functions.
                                                             (line 2031)
* PYTHONLEGACYWINDOWSSTDIO <3>:          Global configuration variables.
                                                             (line  169)
* PYTHONLEGACYWINDOWSSTDIO <4>:          PyConfig.           (line  560)
* PYTHONMALLOC:                          PYTHONMALLOC environment variable.
                                                             (line    6)
* PYTHONMALLOC <1>:                      Changes in the C API<7>.
                                                             (line    9)
* PYTHONMALLOC <2>:                      Core and Builtins<185>.
                                                             (line   90)
* PYTHONMALLOC <3>:                      Environment variables.
                                                             (line  335)
* PYTHONMALLOC <4>:                      Performance options.
                                                             (line  120)
* PYTHONMALLOC <5>:                      Performance options.
                                                             (line  127)
* PYTHONMALLOC <6>:                      Effects of the Python Development Mode.
                                                             (line   46)
* PYTHONMALLOC <7>:                      Effects of the Python Development Mode.
                                                             (line   50)
* PYTHONMALLOC <8>:                      Overview<4>.        (line   75)
* PYTHONMALLOC <9>:                      Default Memory Allocators.
                                                             (line   26)
* PYTHONMALLOC <10>:                     Debug hooks on the Python memory allocators.
                                                             (line   11)
* PYTHONMALLOC <11>:                     The pymalloc allocator.
                                                             (line   27)
* PYTHONMALLOCSTATS:                     Core and Builtins<185>.
                                                             (line   96)
* PYTHONMALLOCSTATS <1>:                 PyConfig.           (line  576)
* PYTHONMALLOCSTATS <2>:                 Overview<4>.        (line   78)
* PYTHONNODEBUGRANGES:                   PEP 657 Fine-grained error locations in tracebacks.
                                                             (line   63)
* PYTHONNODEBUGRANGES <1>:               Miscellaneous options.
                                                             (line  345)
* PYTHONNODEBUGRANGES <2>:               Methods on code objects.
                                                             (line   40)
* PYTHONNODEBUGRANGES <3>:               PyConfig.           (line  249)
* PYTHONNOUSERSITE:                      PEP 370 Per-user site-packages Directory.
                                                             (line   30)
* PYTHONNOUSERSITE <1>:                  Miscellaneous options.
                                                             (line  159)
* PYTHONNOUSERSITE <2>:                  Module contents<5>. (line   15)
* PYTHONNOUSERSITE <3>:                  Global configuration variables.
                                                             (line  203)
* PYTHONNOUSERSITE <4>:                  PyConfig.           (line  960)
* PYTHONOPTIMIZE:                        Miscellaneous options.
                                                             (line   88)
* PYTHONOPTIMIZE <1>:                    Global configuration variables.
                                                             (line  214)
* PYTHONOPTIMIZE <2>:                    PyConfig.           (line  643)
* PYTHONPATH:                            Changes in “python” Command Behavior<2>.
                                                             (line    8)
* PYTHONPATH <1>:                        Changes in “python” Command Behavior<2>.
                                                             (line    9)
* PYTHONPATH <2>:                        Il percorso di ricerca del modulo.
                                                             (line   16)
* PYTHONPATH <3>:                        Moduli Standard.    (line   34)
* PYTHONPATH <4>:                        Moduli Standard.    (line   35)
* PYTHONPATH <5>:                        Miscellaneous options.
                                                             (line   45)
* PYTHONPATH <6>:                        Environment variables.
                                                             (line   32)
* PYTHONPATH <7>:                        Environment variables.
                                                             (line   39)
* PYTHONPATH <8>:                        Environment variables.
                                                             (line   42)
* PYTHONPATH <9>:                        Finding modules.    (line   15)
* PYTHONPATH <10>:                       Finding modules.    (line   38)
* PYTHONPATH <11>:                       Finding modules.    (line   81)
* PYTHONPATH <12>:                       Adding Python to an iOS project.
                                                             (line   90)
* PYTHONPATH <13>:                       Adding Python to an iOS project.
                                                             (line  116)
* PYTHONPATH <14>:                       Adding Python to an iOS project.
                                                             (line  122)
* PYTHONPATH <15>:                       Path entry finders. (line    6)
* PYTHONPATH <16>:                       Path entry finders. (line   23)
* PYTHONPATH <17>:                       test support script_helper — Utilities for the Python execution tests.
                                                             (line   26)
* PYTHONPATH <18>:                       sys — System-specific parameters and functions.
                                                             (line 1453)
* PYTHONPATH <19>:                       sys — System-specific parameters and functions.
                                                             (line 1458)
* PYTHONPATH <20>:                       The initialization of the sys path module search path.
                                                             (line   14)
* PYTHONPATH <21>:                       The initialization of the sys path module search path.
                                                             (line   18)
* PYTHONPATH <22>:                       Embedding Python<2>.
                                                             (line   39)
* PYTHONPATH <23>:                       Embedding Python<2>.
                                                             (line   45)
* PYTHONPATH <24>:                       Global configuration variables.
                                                             (line   91)
* PYTHONPATH <25>:                       PyConfig.           (line  609)
* PYTHONPERFSUPPORT:                     Altre modifiche al Linguaggio.
                                                             (line   92)
* PYTHONPERFSUPPORT <1>:                 Miscellaneous options.
                                                             (line  365)
* PYTHONPERFSUPPORT <2>:                 PyConfig.           (line  904)
* PYTHONPERFSUPPORT <3>:                 How to enable perf profiling support.
                                                             (line    7)
* PYTHONPLATLIBDIR:                      Core and Builtins<144>.
                                                             (line   47)
* PYTHONPLATLIBDIR <1>:                  The initialization of the sys path module search path.
                                                             (line   51)
* PYTHONPLATLIBDIR <2>:                  PyConfig.           (line  588)
* PYTHONPROFILEIMPORTTIME:               Other Language Changes<6>.
                                                             (line   47)
* PYTHONPROFILEIMPORTTIME <1>:           Core and Builtins<167>.
                                                             (line   66)
* PYTHONPROFILEIMPORTTIME <2>:           Miscellaneous options.
                                                             (line  306)
* PYTHONPROFILEIMPORTTIME <3>:           PyConfig.           (line  458)
* PYTHONPYCACHEPREFIX:                   Parallel filesystem cache for compiled bytecode files.
                                                             (line    6)
* PYTHONPYCACHEPREFIX <1>:               Core and Builtins<158>.
                                                             (line  402)
* PYTHONPYCACHEPREFIX <2>:               Miscellaneous options.
                                                             (line  329)
* PYTHONPYCACHEPREFIX <3>:               sys — System-specific parameters and functions.
                                                             (line  386)
* PYTHONPYCACHEPREFIX <4>:               PyConfig.           (line  750)
* PYTHONREGRTEST_UNICODE_GUARD:          Tests<28>.          (line   13)
* PYTHONSAFEPATH:                        Summary – Release highlights<2>.
                                                             (line   27)
* PYTHONSAFEPATH <1>:                    Other Language Changes<2>.
                                                             (line   37)
* PYTHONSAFEPATH <2>:                    Security<28>.       (line    6)
* PYTHONSAFEPATH <3>:                    Miscellaneous options.
                                                             (line  116)
* PYTHONSAFEPATH <4>:                    sys — System-specific parameters and functions.
                                                             (line 1470)
* PYTHONSAFEPATH <5>:                    Security Considerations<3>.
                                                             (line   47)
* PYTHONSAFEPATH <6>:                    PyConfig.           (line  166)
* PYTHONSTARTUP:                         Default interactive shell.
                                                             (line   16)
* PYTHONSTARTUP <1>:                     sys<12>.            (line   17)
* PYTHONSTARTUP <2>:                     sys<12>.            (line   21)
* PYTHONSTARTUP <3>:                     Library.            (line  141)
* PYTHONSTARTUP <4>:                     Core and Builtins<10>.
                                                             (line   41)
* PYTHONSTARTUP <5>:                     IDLE<37>.           (line  176)
* PYTHONSTARTUP <6>:                     IDLE<41>.           (line    9)
* PYTHONSTARTUP <7>:                     IDLE<47>.           (line    9)
* PYTHONSTARTUP <8>:                     Il File di Avvio Interattivo.
                                                             (line    8)
* PYTHONSTARTUP <9>:                     Miscellaneous options.
                                                             (line   64)
* PYTHONSTARTUP <10>:                    Environment variables.
                                                             (line  118)
* PYTHONSTARTUP <11>:                    Example.            (line   10)
* PYTHONSTARTUP <12>:                    asyncio — Asynchronous I/O.
                                                             (line   91)
* PYTHONSTARTUP <13>:                    Startup and Code Execution.
                                                             (line    7)
* PYTHONSTARTUP <14>:                    Command-line usage<5>.
                                                             (line   42)
* PYTHONSTARTUP <15>:                    sys — System-specific parameters and functions.
                                                             (line 1228)
* PYTHONSTARTUP <16>:                    Readline configuration.
                                                             (line   12)
* PYTHONTRACEMALLOC:                     Miscellaneous options.
                                                             (line  285)
* PYTHONTRACEMALLOC <1>:                 tracemalloc — Trace memory allocations.
                                                             (line   25)
* PYTHONTRACEMALLOC <2>:                 tracemalloc — Trace memory allocations.
                                                             (line   32)
* PYTHONTRACEMALLOC <3>:                 Functions<10>.      (line   90)
* PYTHONTRACEMALLOC <4>:                 PyConfig.           (line  890)
* PYTHONTZPATH:                          Exceptions and warnings.
                                                             (line   14)
* PYTHONUNBUFFERED:                      Core and Builtins<151>.
                                                             (line  107)
* PYTHONUNBUFFERED <1>:                  Miscellaneous options.
                                                             (line  179)
* PYTHONUNBUFFERED <2>:                  sys — System-specific parameters and functions.
                                                             (line 2038)
* PYTHONUNBUFFERED <3>:                  Global configuration variables.
                                                             (line  242)
* PYTHONUNBUFFERED <4>:                  PyConfig.           (line  213)
* PYTHONUOPS:                            Core and Builtins<58>.
                                                             (line   27)
* PYTHONUOPS <1>:                        Core and Builtins<58>.
                                                             (line  179)
* PYTHONUOPS <2>:                        Core and Builtins<58>.
                                                             (line  258)
* PYTHONUOPS <3>:                        Core and Builtins<58>.
                                                             (line  317)
* PYTHONUOPS <4>:                        Core and Builtins<58>.
                                                             (line  382)
* PYTHONUSERBASE:                        PEP 370 Per-user site-packages Directory.
                                                             (line   23)
* PYTHONUSERBASE <1>:                    Module contents<5>. (line   40)
* PYTHONUSERBASE <2>:                    Module contents<5>. (line   68)
* PYTHONUSERSITE:                        test support script_helper — Utilities for the Python execution tests.
                                                             (line   26)
* PYTHONUTF8:                            PEP 540 Forced UTF-8 Runtime Mode.
                                                             (line    6)
* PYTHONUTF8 <1>:                        Miscellaneous options.
                                                             (line  323)
* PYTHONUTF8 <2>:                        Environment variables.
                                                             (line  418)
* PYTHONUTF8 <3>:                        UTF-8 mode.         (line   18)
* PYTHONUTF8 <4>:                        Python UTF-8 Mode.  (line   52)
* PYTHONUTF8 <5>:                        Python UTF-8 Mode.  (line   54)
* PYTHONUTF8 <6>:                        sys — System-specific parameters and functions.
                                                             (line 2029)
* PYTHONUTF8 <7>:                        PyPreConfig.        (line  152)
* PYTHONUTF8 <8>:                        Python Configuration.
                                                             (line   14)
* PYTHONVERBOSE:                         Miscellaneous options.
                                                             (line  195)
* PYTHONVERBOSE <1>:                     Global configuration variables.
                                                             (line  259)
* PYTHONVERBOSE <2>:                     PyConfig.           (line  977)
* PYTHONWARNDEFAULTENCODING:             Optional EncodingWarning and encoding="locale" option.
                                                             (line   19)
* PYTHONWARNDEFAULTENCODING <1>:         Library<120>.       (line   45)
* PYTHONWARNDEFAULTENCODING <2>:         Miscellaneous options.
                                                             (line  335)
* PYTHONWARNDEFAULTENCODING <3>:         Opt-in EncodingWarning.
                                                             (line    9)
* PYTHONWARNINGS:                        warnings<3>.        (line   21)
* PYTHONWARNINGS <1>:                    Other Language Changes<11>.
                                                             (line  160)
* PYTHONWARNINGS <2>:                    Changes to the Handling of Deprecation Warnings.
                                                             (line   25)
* PYTHONWARNINGS <3>:                    Interpreter Changes.
                                                             (line    6)
* PYTHONWARNINGS <4>:                    Documentation<27>.  (line   67)
* PYTHONWARNINGS <5>:                    Miscellaneous options.
                                                             (line  249)
* PYTHONWARNINGS <6>:                    Effects of the Python Development Mode.
                                                             (line   30)
* PYTHONWARNINGS <7>:                    The Warnings Filter.
                                                             (line   49)
* PYTHONWARNINGS <8>:                    The Warnings Filter.
                                                             (line   59)
* PYTHONWARNINGS <9>:                    Describing Warning Filters.
                                                             (line    7)
* PYTHONWARNINGS <10>:                   Describing Warning Filters.
                                                             (line   21)
* PYTHONWARNINGS <11>:                   Default Warning Filter.
                                                             (line    7)
* PYTHONWARNINGS <12>:                   PyConfig.           (line  996)
* PyThread_acquire_lock (C function):    Legacy Locking APIs.
                                                             (line   76)
* PyThread_acquire_lock_timed (C function): Legacy Locking APIs.
                                                             (line   53)
* PyThread_allocate_lock (C function):   Legacy Locking APIs.
                                                             (line   32)
* PyThread_create_key (C function):      Thread Local Storage TLS API.
                                                             (line   18)
* PyThread_delete_key (C function):      Thread Local Storage TLS API.
                                                             (line   21)
* PyThread_delete_key_value (C function): Thread Local Storage TLS API.
                                                             (line   30)
* PyThread_exit_thread (C function):     Operating System Thread APIs.
                                                             (line   71)
* PyThread_free_lock (C function):       Legacy Locking APIs.
                                                             (line   46)
* PyThread_get_key_value (C function):   Thread Local Storage TLS API.
                                                             (line   27)
* PyThread_get_stacksize (C function):   Operating System Thread APIs.
                                                             (line  110)
* PyThread_get_thread_ident (C function): Operating System Thread APIs.
                                                             (line   26)
* PyThread_get_thread_native_id (C function): Operating System Thread APIs.
                                                             (line   54)
* PyThread_GetInfo (C function):         Operating System Thread APIs.
                                                             (line   38)
* PyThread_init_thread (C function):     Operating System Thread APIs.
                                                             (line   94)
* PYTHREAD_INVALID_THREAD_ID (C macro):  Operating System Thread APIs.
                                                             (line    6)
* PyThread_ReInitTLS (C function):       Thread Local Storage TLS API.
                                                             (line   33)
* PyThread_release_lock (C function):    Legacy Locking APIs.
                                                             (line   95)
* PyThread_set_key_value (C function):   Thread Local Storage TLS API.
                                                             (line   24)
* PyThread_set_stacksize (C function):   Operating System Thread APIs.
                                                             (line   99)
* PyThread_start_new_thread (C function): Operating System Thread APIs.
                                                             (line   12)
* PyThread_tss_alloc (C function):       Dynamic Allocation. (line   11)
* PyThread_tss_create (C function):      Methods.            (line   16)
* PyThread_tss_delete (C function):      Methods.            (line   24)
* PyThread_tss_free (C function):        Dynamic Allocation. (line   17)
* PyThread_tss_get (C function):         Methods.            (line   39)
* PyThread_tss_is_created (C function):  Methods.            (line   11)
* PyThread_tss_set (C function):         Methods.            (line   33)
* PyThread_type_lock (C type):           Legacy Locking APIs.
                                                             (line   12)
* PyThreadState (C type):                Thread State and the Global Interpreter Lock.
                                                             (line   24)
* PyThreadState (C type) <1>:            High-level API.     (line   25)
* PyThreadState_Clear (C function):      Low-level API.      (line   45)
* PyThreadState_Delete (C function):     Low-level API.      (line   57)
* PyThreadState_DeleteCurrent (C function): Low-level API.   (line   63)
* PyThreadState_EnterTracing (C function): Low-level API.    (line  104)
* PyThreadState_Get (C function):        High-level API.     (line   73)
* PyThreadState_GetDict (C function):    Low-level API.      (line  253)
* PyThreadState_GetFrame (C function):   Low-level API.      (line   72)
* PyThreadState_GetID (C function):      Low-level API.      (line   86)
* PyThreadState_GetInterpreter (C function): Low-level API.  (line   95)
* PyThreadState_GetUnchecked (C function): High-level API.   (line   82)
* PyThreadState_LeaveTracing (C function): Low-level API.    (line  113)
* PyThreadState_New (C function):        Low-level API.      (line   39)
* PyThreadState_Next (C function):       Advanced Debugger Support.
                                                             (line   32)
* PyThreadState_SetAsyncExc (C function): Low-level API.     (line  263)
* PyThreadState_Swap (C function):       High-level API.     (line   91)
* PyThreadState.interp (C member):       High-level API.     (line   30)
* PyTime_AsSecondsDouble (C function):   Conversion functions.
                                                             (line    6)
* PyTime_Check (C function):             DateTime Objects<2>.
                                                             (line  126)
* PyTime_CheckExact (C function):        DateTime Objects<2>.
                                                             (line  132)
* PyTime_FromTime (C function):          DateTime Objects<2>.
                                                             (line  182)
* PyTime_FromTimeAndFold (C function):   DateTime Objects<2>.
                                                             (line  188)
* PyTime_MAX (C var):                    Types<3>.           (line   24)
* PyTime_MIN (C var):                    Types<3>.           (line   20)
* PyTime_Monotonic (C function):         Clock Functions.    (line   21)
* PyTime_MonotonicRaw (C function):      Raw Clock Functions.
                                                             (line   16)
* PyTime_PerfCounter (C function):       Clock Functions.    (line   26)
* PyTime_PerfCounterRaw (C function):    Raw Clock Functions.
                                                             (line   22)
* PyTime_t (C type):                     Types<3>.           (line    6)
* PyTime_Time (C function):              Clock Functions.    (line   31)
* PyTime_TimeRaw (C function):           Raw Clock Functions.
                                                             (line   28)
* PyTimeZone_FromOffset (C function):    DateTime Objects<2>.
                                                             (line  204)
* PyTimeZone_FromOffsetAndName (C function): DateTime Objects<2>.
                                                             (line  212)
* PyTrace_C_CALL (C var):                Profiling and Tracing.
                                                             (line   94)
* PyTrace_C_EXCEPTION (C var):           Profiling and Tracing.
                                                             (line   99)
* PyTrace_C_RETURN (C var):              Profiling and Tracing.
                                                             (line  104)
* PyTrace_CALL (C var):                  Profiling and Tracing.
                                                             (line   62)
* PyTrace_EXCEPTION (C var):             Profiling and Tracing.
                                                             (line   70)
* PyTrace_LINE (C var):                  Profiling and Tracing.
                                                             (line   82)
* PyTrace_OPCODE (C var):                Profiling and Tracing.
                                                             (line  109)
* PyTrace_RETURN (C var):                Profiling and Tracing.
                                                             (line   89)
* PyTraceBack_Check (C function):        Tracebacks.         (line   11)
* PyTraceBack_Here (C function):         Tracebacks.         (line   16)
* PyTraceBack_Print (C function):        Tracebacks.         (line   27)
* PyTraceBack_Type (C var):              Tracebacks.         (line    6)
* PyTraceMalloc_Track (C function):      tracemalloc C API.  (line    8)
* PyTraceMalloc_Untrack (C function):    tracemalloc C API.  (line   20)
* PyTuple_Check (C function):            Tuple Objects.      (line   16)
* PyTuple_CheckExact (C function):       Tuple Objects.      (line   21)
* PyTuple_GET_ITEM (C function):         Tuple Objects.      (line   61)
* PyTuple_GET_SIZE (C function):         Tuple Objects.      (line   44)
* PyTuple_GetItem (C function):          Tuple Objects.      (line   48)
* PyTuple_GetSlice (C function):         Tuple Objects.      (line   66)
* PyTuple_New (C function):              Tuple Objects.      (line   26)
* PyTuple_Pack (C function):             Tuple Objects.      (line   31)
* PyTuple_SET_ITEM (C function):         Tuple Objects.      (line   87)
* PyTuple_SetItem (C function):          Reference Count Details.
                                                             (line   26)
* PyTuple_SetItem (C function) <1>:      Tuple Objects.      (line   76)
* PyTuple_Size (C function):             Tuple Objects.      (line   39)
* PyTuple_Type (C var):                  Tuple Objects.      (line   11)
* PyTupleIter_Type (C var):              Other Iterator Objects.
                                                             (line   21)
* PyTupleObject (C type):                Tuple Objects.      (line    6)
* PyType_AddWatcher (C function):        Type Objects.       (line   67)
* PyType_Check (C function):             Type Objects.       (line   15)
* PyType_CheckExact (C function):        Type Objects.       (line   21)
* PyType_ClearCache (C function):        Type Objects.       (line   27)
* PyType_ClearWatcher (C function):      Type Objects.       (line   80)
* PyType_FastSubclass (C function):      Type Objects.       (line  138)
* PyType_Freeze (C function):            Creating Heap-Allocated Types.
                                                             (line  115)
* PyType_FromMetaclass (C function):     Creating Heap-Allocated Types.
                                                             (line    9)
* PyType_FromModuleAndSpec (C function): Creating Heap-Allocated Types.
                                                             (line   56)
* PyType_FromSpec (C function):          Creating Heap-Allocated Types.
                                                             (line   97)
* PyType_FromSpecWithBases (C function): Creating Heap-Allocated Types.
                                                             (line   78)
* PyType_GenericAlloc (C function):      Type Objects.       (line  166)
* PyType_GenericNew (C function):        Type Objects.       (line  188)
* PyType_GetBaseByToken (C function):    Type Objects.       (line  319)
* PyType_GetDict (C function):           Type Objects.       (line   43)
* PyType_GetFlags (C function):          Type Objects.       (line   31)
* PyType_GetFullyQualifiedName (C function): Type Objects.   (line  228)
* PyType_GetModule (C function):         Type Objects.       (line  263)
* PyType_GetModuleByDef (C function):    Type Objects.       (line  297)
* PyType_GetModuleName (C function):     Type Objects.       (line  238)
* PyType_GetModuleState (C function):    Type Objects.       (line  283)
* PyType_GetName (C function):           Type Objects.       (line  211)
* PyType_GetQualName (C function):       Type Objects.       (line  219)
* PyType_GetSlot (C function):           Type Objects.       (line  246)
* PyType_GetTypeDataSize (C function):   Object Protocol.    (line  557)
* PyType_HasFeature (C function):        Type Objects.       (line  133)
* PyType_IS_GC (C function):             Type Objects.       (line  152)
* PyType_IsSubtype (C function):         Type Objects.       (line  157)
* PyType_Modified (C function):          Type Objects.       (line   61)
* PyType_Ready (C function):             Type Objects.       (line  195)
* PyType_Slot (C type):                  Creating Heap-Allocated Types.
                                                             (line  197)
* PyType_Slot.pfunc (C member):          Creating Heap-Allocated Types.
                                                             (line  266)
* PyType_Slot.slot (C member):           Creating Heap-Allocated Types.
                                                             (line  202)
* PyType_Spec (C type):                  Creating Heap-Allocated Types.
                                                             (line  130)
* PyType_Spec.basicsize (C member):      Creating Heap-Allocated Types.
                                                             (line  139)
* PyType_Spec.flags (C member):          Creating Heap-Allocated Types.
                                                             (line  183)
* PyType_Spec.itemsize (C member):       Creating Heap-Allocated Types.
                                                             (line  157)
* PyType_Spec.name (C member):           Creating Heap-Allocated Types.
                                                             (line  134)
* PyType_Spec.slots (C member):          Creating Heap-Allocated Types.
                                                             (line  190)
* PyType_SUPPORTS_WEAKREFS (C function): Type Objects.       (line  351)
* PyType_Type (C var):                   Type Objects.       (line   10)
* PyType_Unwatch (C function):           Type Objects.       (line  108)
* PyType_Watch (C function):             Type Objects.       (line   92)
* PyType_WatchCallback (C type):         Type Objects.       (line  122)
* PyTypeObject (C type):                 Type Objects.       (line    6)
* PyTypeObject.tp_alloc (C member):      PyTypeObject Slots. (line 1649)
* PyTypeObject.tp_as_async (C member):   PyTypeObject Slots. (line  366)
* PyTypeObject.tp_as_buffer (C member):  PyTypeObject Slots. (line  598)
* PyTypeObject.tp_as_mapping (C member): PyTypeObject Slots. (line  435)
* PyTypeObject.tp_as_number (C member):  PyTypeObject Slots. (line  411)
* PyTypeObject.tp_as_sequence (C member): PyTypeObject Slots.
                                                             (line  423)
* PyTypeObject.tp_base (C member):       PyTypeObject Slots. (line 1460)
* PyTypeObject.tp_bases (C member):      PyTypeObject Slots. (line 1780)
* PyTypeObject.tp_basicsize (C member):  PyTypeObject Slots. (line   48)
* PyTypeObject.tp_cache (C member):      PyTypeObject Slots. (line 1817)
* PyTypeObject.tp_call (C member):       PyTypeObject Slots. (line  492)
* PyTypeObject.tp_clear (C member):      PyTypeObject Slots. (line 1083)
* PyTypeObject.tp_dealloc (C member):    PyTypeObject Slots. (line  134)
* PyTypeObject.tp_del (C member):        PyTypeObject Slots. (line 1856)
* PyTypeObject.tp_descr_get (C member):  PyTypeObject Slots. (line 1531)
* PyTypeObject.tp_descr_set (C member):  PyTypeObject Slots. (line 1547)
* PyTypeObject.tp_dict (C member):       PyTypeObject Slots. (line 1495)
* PyTypeObject.tp_dictoffset (C member): PyTypeObject Slots. (line 1566)
* PyTypeObject.tp_doc (C member):        PyTypeObject Slots. (line  965)
* PyTypeObject.tp_finalize (C member):   PyTypeObject Slots. (line 1871)
* PyTypeObject.tp_flags (C member):      PyTypeObject Slots. (line  610)
* PyTypeObject.tp_free (C member):       PyTypeObject Slots. (line 1716)
* PyTypeObject.tp_getattr (C member):    PyTypeObject Slots. (line  319)
* PyTypeObject.tp_getattro (C member):   PyTypeObject Slots. (line  536)
* PyTypeObject.tp_getset (C member):     PyTypeObject Slots. (line 1441)
* PyTypeObject.tp_hash (C member):       PyTypeObject Slots. (line  447)
* PyTypeObject.tp_init (C member):       PyTypeObject Slots. (line 1610)
* PyTypeObject.tp_is_gc (C member):      PyTypeObject Slots. (line 1748)
* PyTypeObject.tp_itemsize (C member):   PyTypeObject Slots. (line   48)
* PyTypeObject.tp_iter (C member):       PyTypeObject Slots. (line 1358)
* PyTypeObject.tp_iternext (C member):   PyTypeObject Slots. (line 1377)
* PyTypeObject.tp_members (C member):    PyTypeObject Slots. (line 1422)
* PyTypeObject.tp_methods (C member):    PyTypeObject Slots. (line 1403)
* PyTypeObject.tp_mro (C member):        PyTypeObject Slots. (line 1803)
* PyTypeObject.tp_name (C member):       PyTypeObject Slots. (line   12)
* PyTypeObject.tp_new (C member):        PyTypeObject Slots. (line 1674)
* PyTypeObject.tp_repr (C member):       PyTypeObject Slots. (line  382)
* PyTypeObject.tp_richcompare (C member): PyTypeObject Slots.
                                                             (line 1242)
* PyTypeObject.tp_setattr (C member):    PyTypeObject Slots. (line  342)
* PyTypeObject.tp_setattro (C member):   PyTypeObject Slots. (line  566)
* PyTypeObject.tp_str (C member):        PyTypeObject Slots. (line  507)
* PyTypeObject.tp_subclasses (C member): PyTypeObject Slots. (line 1825)
* PyTypeObject.tp_traverse (C member):   PyTypeObject Slots. (line  978)
* PyTypeObject.tp_vectorcall (C member): PyTypeObject Slots. (line 2041)
* PyTypeObject.tp_vectorcall_offset (C member): PyTypeObject Slots.
                                                             (line  279)
* PyTypeObject.tp_version_tag (C member): PyTypeObject Slots.
                                                             (line 1863)
* PyTypeObject.tp_watched (C member):    PyTypeObject Slots. (line 2084)
* PyTypeObject.tp_weaklist (C member):   PyTypeObject Slots. (line 1841)
* PyTypeObject.tp_weaklistoffset (C member): PyTypeObject Slots.
                                                             (line 1322)
* PyTZInfo_Check (C function):           DateTime Objects<2>.
                                                             (line  148)
* PyTZInfo_CheckExact (C function):      DateTime Objects<2>.
                                                             (line  154)
* PyUnicode_1BYTE_DATA (C function):     Unicode Type.       (line   79)
* PyUnicode_1BYTE_KIND (C macro):        Unicode Type.       (line   94)
* PyUnicode_2BYTE_DATA (C function):     Unicode Type.       (line   79)
* PyUnicode_2BYTE_KIND (C macro):        Unicode Type.       (line   94)
* PyUnicode_4BYTE_DATA (C function):     Unicode Type.       (line   79)
* PyUnicode_4BYTE_KIND (C macro):        Unicode Type.       (line   94)
* PyUnicode_Append (C function):         Creating and accessing Unicode strings.
                                                             (line  320)
* PyUnicode_AppendAndDel (C function):   Creating and accessing Unicode strings.
                                                             (line  331)
* PyUnicode_AsASCIIString (C function):  ASCII Codecs.       (line   16)
* PyUnicode_AsCharmapString (C function): Character Map Codecs.
                                                             (line   31)
* PyUnicode_AsEncodedString (C function): Generic Codecs.    (line   27)
* PyUnicode_AsLatin1String (C function): Latin-1 Codecs.     (line   17)
* PyUnicode_AsMBCSString (C function):   MBCS codecs for Windows.
                                                             (line   37)
* PyUnicode_AsRawUnicodeEscapeString (C function): Raw-Unicode-Escape Codecs.
                                                             (line   15)
* PyUnicode_AsUCS4 (C function):         Creating and accessing Unicode strings.
                                                             (line  452)
* PyUnicode_AsUCS4Copy (C function):     Creating and accessing Unicode strings.
                                                             (line  462)
* PyUnicode_AsUnicodeEscapeString (C function): Unicode-Escape Codecs.
                                                             (line   15)
* PyUnicode_AsUTF16String (C function):  UTF-16 Codecs.      (line   48)
* PyUnicode_AsUTF32String (C function):  UTF-32 Codecs.      (line   47)
* PyUnicode_AsUTF8 (C function):         UTF-8 Codecs.       (line   65)
* PyUnicode_AsUTF8AndSize (C function):  UTF-8 Codecs.       (line   35)
* PyUnicode_AsUTF8String (C function):   UTF-8 Codecs.       (line   25)
* PyUnicode_AsWideChar (C function):     wchar_t Support.    (line   16)
* PyUnicode_AsWideCharString (C function): wchar_t Support.  (line   34)
* PyUnicode_BuildEncodingMap (C function): Creating and accessing Unicode strings.
                                                             (line  337)
* PyUnicode_Check (C function):          Unicode Type.       (line   60)
* PyUnicode_CHECK_INTERNED (C function): Methods and Slot Functions.
                                                             (line  277)
* PyUnicode_CheckExact (C function):     Unicode Type.       (line   65)
* PyUnicode_Compare (C function):        Methods and Slot Functions.
                                                             (line  132)
* PyUnicode_CompareWithASCIIString (C function): Methods and Slot Functions.
                                                             (line  191)
* PyUnicode_Concat (C function):         Methods and Slot Functions.
                                                             (line   12)
* PyUnicode_Contains (C function):       Methods and Slot Functions.
                                                             (line  225)
* PyUnicode_CopyCharacters (C function): Creating and accessing Unicode strings.
                                                             (line  366)
* PyUnicode_Count (C function):          Methods and Slot Functions.
                                                             (line  118)
* PyUnicode_DATA (C function):           Unicode Type.       (line  114)
* PyUnicode_Decode (C function):         Generic Codecs.     (line   17)
* PyUnicode_DecodeASCII (C function):    ASCII Codecs.       (line    9)
* PyUnicode_DecodeCharmap (C function):  Character Map Codecs.
                                                             (line   15)
* PyUnicode_DecodeCodePageStateful (C function): MBCS codecs for Windows.
                                                             (line   29)
* PyUnicode_DecodeFSDefault (C function): File System Encoding.
                                                             (line   75)
* PyUnicode_DecodeFSDefaultAndSize (C function): File System Encoding.
                                                             (line   58)
* PyUnicode_DecodeLatin1 (C function):   Latin-1 Codecs.     (line   10)
* PyUnicode_DecodeLocale (C function):   Locale Encoding.    (line   37)
* PyUnicode_DecodeLocaleAndSize (C function): Locale Encoding.
                                                             (line    9)
* PyUnicode_DecodeMBCS (C function):     MBCS codecs for Windows.
                                                             (line   12)
* PyUnicode_DecodeMBCSStateful (C function): MBCS codecs for Windows.
                                                             (line   19)
* PyUnicode_DecodeRawUnicodeEscape (C function): Raw-Unicode-Escape Codecs.
                                                             (line    8)
* PyUnicode_DecodeUnicodeEscape (C function): Unicode-Escape Codecs.
                                                             (line    8)
* PyUnicode_DecodeUTF16 (C function):    UTF-16 Codecs.      (line    8)
* PyUnicode_DecodeUTF16Stateful (C function): UTF-16 Codecs. (line   36)
* PyUnicode_DecodeUTF32 (C function):    UTF-32 Codecs.      (line    8)
* PyUnicode_DecodeUTF32Stateful (C function): UTF-32 Codecs. (line   35)
* PyUnicode_DecodeUTF7 (C function):     UTF-7 Codecs.       (line    8)
* PyUnicode_DecodeUTF7Stateful (C function): UTF-7 Codecs.   (line   15)
* PyUnicode_DecodeUTF8 (C function):     UTF-8 Codecs.       (line    8)
* PyUnicode_DecodeUTF8Stateful (C function): UTF-8 Codecs.   (line   15)
* PyUnicode_EncodeCodePage (C function): MBCS codecs for Windows.
                                                             (line   45)
* PyUnicode_EncodeFSDefault (C function): File System Encoding.
                                                             (line   87)
* PyUnicode_EncodeLocale (C function):   Locale Encoding.    (line   46)
* PyUnicode_Equal (C function):          Methods and Slot Functions.
                                                             (line  145)
* PyUnicode_EqualToUTF8 (C function):    Methods and Slot Functions.
                                                             (line  182)
* PyUnicode_EqualToUTF8AndSize (C function): Methods and Slot Functions.
                                                             (line  169)
* PyUnicode_Fill (C function):           Creating and accessing Unicode strings.
                                                             (line  396)
* PyUnicode_Find (C function):           Methods and Slot Functions.
                                                             (line   91)
* PyUnicode_FindChar (C function):       Methods and Slot Functions.
                                                             (line  102)
* PyUnicode_Format (C function):         Methods and Slot Functions.
                                                             (line  219)
* PyUnicode_FromEncodedObject (C function): Creating and accessing Unicode strings.
                                                             (line  303)
* PyUnicode_FromFormat (C function):     Creating and accessing Unicode strings.
                                                             (line   83)
* PyUnicode_FromFormatV (C function):    Creating and accessing Unicode strings.
                                                             (line  277)
* PyUnicode_FromKindAndData (C function): Creating and accessing Unicode strings.
                                                             (line   43)
* PyUnicode_FromObject (C function):     Creating and accessing Unicode strings.
                                                             (line  283)
* PyUnicode_FromOrdinal (C function):    Creating and accessing Unicode strings.
                                                             (line  294)
* PyUnicode_FromString (C function):     Creating and accessing Unicode strings.
                                                             (line   77)
* PyUnicode_FromStringAndSize (C function): Creating and accessing Unicode strings.
                                                             (line   60)
* PyUnicode_FromWideChar (C function):   wchar_t Support.    (line    8)
* PyUnicode_FSConverter (C function):    File System Encoding.
                                                             (line   13)
* PyUnicode_FSDecoder (C function):      File System Encoding.
                                                             (line   37)
* PyUnicode_GET_LENGTH (C function):     Unicode Type.       (line   70)
* PyUnicode_GetDefaultEncoding (C function): Creating and accessing Unicode strings.
                                                             (line  349)
* PyUnicode_GetLength (C function):      Creating and accessing Unicode strings.
                                                             (line  357)
* PyUnicode_InternFromString (C function): Methods and Slot Functions.
                                                             (line  259)
* PyUnicode_InternInPlace (C function):  Methods and Slot Functions.
                                                             (line  233)
* PyUnicode_IS_ASCII (C function):       Unicode Type.       (line  176)
* PyUnicode_IS_COMPACT (C macro):        Unicode Type.       (line   44)
* PyUnicode_IS_COMPACT_ASCII (C macro):  Unicode Type.       (line   51)
* PyUnicode_IS_READY (C function):       Deprecated API<2>.  (line   31)
* PyUnicode_IsIdentifier (C function):   Unicode Type.       (line  167)
* PyUnicode_Join (C function):           Methods and Slot Functions.
                                                             (line   77)
* PyUnicode_KIND (C function):           Unicode Type.       (line  105)
* PyUnicode_MAX_CHAR_VALUE (C function): Unicode Type.       (line  157)
* PyUnicode_New (C function):            Creating and accessing Unicode strings.
                                                             (line    9)
* PyUnicode_Partition (C function):      Methods and Slot Functions.
                                                             (line   48)
* PyUnicode_READ (C function):           Unicode Type.       (line  139)
* PyUnicode_READ_CHAR (C function):      Unicode Type.       (line  148)
* PyUnicode_ReadChar (C function):       Creating and accessing Unicode strings.
                                                             (line  430)
* PyUnicode_READY (C function):          Deprecated API<2>.  (line   20)
* PyUnicode_Replace (C function):        Methods and Slot Functions.
                                                             (line  124)
* PyUnicode_Resize (C function):         Creating and accessing Unicode strings.
                                                             (line  380)
* PyUnicode_RichCompare (C function):    Methods and Slot Functions.
                                                             (line  201)
* PyUnicode_RPartition (C function):     Methods and Slot Functions.
                                                             (line   63)
* PyUnicode_RSplit (C function):         Methods and Slot Functions.
                                                             (line   30)
* PyUnicode_Split (C function):          Methods and Slot Functions.
                                                             (line   17)
* PyUnicode_Splitlines (C function):     Methods and Slot Functions.
                                                             (line   40)
* PyUnicode_Substring (C function):      Creating and accessing Unicode strings.
                                                             (line  442)
* PyUnicode_Tailmatch (C function):      Methods and Slot Functions.
                                                             (line   83)
* PyUnicode_Translate (C function):      Character Map Codecs.
                                                             (line   46)
* PyUnicode_Type (C var):                Unicode Type.       (line    9)
* PyUnicode_WRITE (C function):          Unicode Type.       (line  122)
* PyUnicode_WriteChar (C function):      Creating and accessing Unicode strings.
                                                             (line  414)
* PyUnicodeDecodeError_Create (C function): Unicode Exception Objects.
                                                             (line    9)
* PyUnicodeDecodeError_GetEncoding (C function): Unicode Exception Objects.
                                                             (line   17)
* PyUnicodeDecodeError_GetEnd (C function): Unicode Exception Objects.
                                                             (line   68)
* PyUnicodeDecodeError_GetObject (C function): Unicode Exception Objects.
                                                             (line   25)
* PyUnicodeDecodeError_GetReason (C function): Unicode Exception Objects.
                                                             (line   97)
* PyUnicodeDecodeError_GetStart (C function): Unicode Exception Objects.
                                                             (line   35)
* PyUnicodeDecodeError_SetEnd (C function): Unicode Exception Objects.
                                                             (line   82)
* PyUnicodeDecodeError_SetReason (C function): Unicode Exception Objects.
                                                             (line  107)
* PyUnicodeDecodeError_SetStart (C function): Unicode Exception Objects.
                                                             (line   54)
* PyUnicodeEncodeError_GetEncoding (C function): Unicode Exception Objects.
                                                             (line   17)
* PyUnicodeEncodeError_GetEnd (C function): Unicode Exception Objects.
                                                             (line   68)
* PyUnicodeEncodeError_GetObject (C function): Unicode Exception Objects.
                                                             (line   25)
* PyUnicodeEncodeError_GetReason (C function): Unicode Exception Objects.
                                                             (line   97)
* PyUnicodeEncodeError_GetStart (C function): Unicode Exception Objects.
                                                             (line   35)
* PyUnicodeEncodeError_SetEnd (C function): Unicode Exception Objects.
                                                             (line   82)
* PyUnicodeEncodeError_SetReason (C function): Unicode Exception Objects.
                                                             (line  107)
* PyUnicodeEncodeError_SetStart (C function): Unicode Exception Objects.
                                                             (line   54)
* PyUnicodeIter_Type (C var):            Unicode Type.       (line   14)
* PyUnicodeObject (C type):              Unicode Type.       (line   29)
* PyUnicodeTranslateError_GetEnd (C function): Unicode Exception Objects.
                                                             (line   68)
* PyUnicodeTranslateError_GetObject (C function): Unicode Exception Objects.
                                                             (line   25)
* PyUnicodeTranslateError_GetReason (C function): Unicode Exception Objects.
                                                             (line   97)
* PyUnicodeTranslateError_GetStart (C function): Unicode Exception Objects.
                                                             (line   35)
* PyUnicodeTranslateError_SetEnd (C function): Unicode Exception Objects.
                                                             (line   82)
* PyUnicodeTranslateError_SetReason (C function): Unicode Exception Objects.
                                                             (line  107)
* PyUnicodeTranslateError_SetStart (C function): Unicode Exception Objects.
                                                             (line   54)
* PyUnicodeWriter (C type):              PyUnicodeWriter.    (line   11)
* PyUnicodeWriter_Create (C function):   PyUnicodeWriter.    (line   18)
* PyUnicodeWriter_DecodeUTF8Stateful (C function): PyUnicodeWriter.
                                                             (line  147)
* PyUnicodeWriter_Discard (C function):  PyUnicodeWriter.    (line   40)
* PyUnicodeWriter_Finish (C function):   PyUnicodeWriter.    (line   30)
* PyUnicodeWriter_Format (C function):   PyUnicodeWriter.    (line  138)
* PyUnicodeWriter_WriteASCII (C function): PyUnicodeWriter.  (line   71)
* PyUnicodeWriter_WriteChar (C function): PyUnicodeWriter.   (line   49)
* PyUnicodeWriter_WriteRepr (C function): PyUnicodeWriter.   (line  117)
* PyUnicodeWriter_WriteStr (C function): PyUnicodeWriter.    (line  108)
* PyUnicodeWriter_WriteSubstring (C function): PyUnicodeWriter.
                                                             (line  126)
* PyUnicodeWriter_WriteUCS4 (C function): PyUnicodeWriter.   (line   98)
* PyUnicodeWriter_WriteUTF8 (C function): PyUnicodeWriter.   (line   57)
* PyUnicodeWriter_WriteWideChar (C function): PyUnicodeWriter.
                                                             (line   87)
* PyUnstable:                            Unstable C API.     (line    6)
* PyUnstable_AtExit (C function):        Initializing and finalizing the interpreter.
                                                             (line  214)
* PyUnstable_Code_GetExtra (C function): Extra information.  (line   35)
* PyUnstable_Code_GetFirstFree (C function): Code Objects.   (line   31)
* PyUnstable_Code_New (C function):      Code Objects.       (line   41)
* PyUnstable_Code_NewWithPosOnlyArgs (C function): Code Objects.
                                                             (line   68)
* PyUnstable_Code_SetExtra (C function): Extra information.  (line   51)
* PyUnstable_EnableTryIncRef (C function): Object Protocol.  (line  750)
* PyUnstable_Eval_RequestCodeExtraIndex (C function): Extra information.
                                                             (line   14)
* PyUnstable_Exc_PrepReraiseStar (C function): Exception Objects.
                                                             (line   71)
* PyUnstable_GC_VisitObjects (C function): Querying Garbage Collector State.
                                                             (line    9)
* PyUnstable_InterpreterFrame_GetCode (C function): Internal Frames.
                                                             (line   14)
* PyUnstable_InterpreterFrame_GetLasti (C function): Internal Frames.
                                                             (line   24)
* PyUnstable_InterpreterFrame_GetLine (C function): Internal Frames.
                                                             (line   32)
* PyUnstable_IsImmortal (C function):    Object Protocol.    (line  666)
* PyUnstable_Long_CompactValue (C function): Integer Objects.
                                                             (line  658)
* PyUnstable_Long_IsCompact (C function): Integer Objects.   (line  640)
* PyUnstable_Module_SetGIL (C function): Support functions.  (line  192)
* PyUnstable_Object_ClearWeakRefsNoCallbacks (C function): Weak Reference Objects<2>.
                                                             (line  125)
* PyUnstable_Object_EnableDeferredRefcount (C function): Object Protocol.
                                                             (line  604)
* PyUnstable_Object_GC_NewWithExtraData (C function): Supporting Cyclic Garbage Collection.
                                                             (line  110)
* PyUnstable_Object_IsUniquelyReferenced (C function): Object Protocol.
                                                             (line  759)
* PyUnstable_Object_IsUniqueReferencedTemporary (C function): Object Protocol.
                                                             (line  633)
* PyUnstable_PerfMapState_Fini (C function): Support for Perf Maps.
                                                             (line   48)
* PyUnstable_PerfMapState_Init (C function): Support for Perf Maps.
                                                             (line   19)
* PyUnstable_ThreadState_ResetStackProtection (C function): Low-level API.
                                                             (line  162)
* PyUnstable_ThreadState_SetStackProtection (C function): Low-level API.
                                                             (line  123)
* PyUnstable_TryIncRef (C function):     Object Protocol.    (line  677)
* PyUnstable_Type_AssignVersionTag (C function): Type Objects.
                                                             (line  340)
* PyUnstable_WritePerfMapEntry (C function): Support for Perf Maps.
                                                             (line   33)
* PyVarObject (C type):                  Base object types and macros.
                                                             (line   42)
* PyVarObject_HEAD_INIT (C macro):       Base object types and macros.
                                                             (line  179)
* PyVarObject.ob_size (C member):        Base object types and macros.
                                                             (line   52)
* PyVectorcall_Call (C function):        Vectorcall Support API.
                                                             (line   33)
* PyVectorcall_Function (C function):    Vectorcall Support API.
                                                             (line   19)
* PyVectorcall_NARGS (C function):       Vectorcall Support API.
                                                             (line    6)
* PyWeakref_Check (C function):          Weak Reference Objects<2>.
                                                             (line   11)
* PyWeakref_CheckProxy (C function):     Weak Reference Objects<2>.
                                                             (line   26)
* PyWeakref_CheckRef (C function):       Weak Reference Objects<2>.
                                                             (line   16)
* PyWeakref_CheckRefExact (C function):  Weak Reference Objects<2>.
                                                             (line   21)
* PyWeakref_GET_OBJECT (C function):     Weak Reference Objects<2>.
                                                             (line  101)
* PyWeakref_GetObject (C function):      Weak Reference Objects<2>.
                                                             (line   85)
* PyWeakref_GetRef (C function):         Weak Reference Objects<2>.
                                                             (line   71)
* PyWeakref_IsDead (C function):         Weak Reference Objects<2>.
                                                             (line  109)
* PyWeakref_NewProxy (C function):       Weak Reference Objects<2>.
                                                             (line   51)
* PyWeakref_NewRef (C function):         Weak Reference Objects<2>.
                                                             (line   31)
* PyWideStringList (C type):             PyWideStringList.   (line    6)
* PyWideStringList_Append (C function):  PyWideStringList.   (line   15)
* PyWideStringList_Insert (C function):  PyWideStringList.   (line   22)
* PyWideStringList.items (C member):     PyWideStringList.   (line   41)
* PyWideStringList.length (C member):    PyWideStringList.   (line   37)
* PyWrapper_New (C function):            Descriptor Objects. (line   72)
* PyWrapperDescr_Type (C var):           Descriptor Objects. (line   53)
* PyZip_Type (C var):                    Builtin Iterator Types.
                                                             (line   28)
* PyZipFile (classe in zipfile):         PyZipFile objects.  (line   10)
* qiflush() (nel modulo curses):         Functions<5>.       (line  414)
* QName (classe in xml.etree.ElementTree): QName Objects.    (line    6)
* qsize() (asyncio.Queue metodo):        Queue.              (line   80)
* qsize() (multiprocessing.Queue metodo): Pipes and Queues.  (line  110)
* qsize() (queue.Queue metodo):          Queue Objects.      (line    9)
* qsize() (queue.SimpleQueue metodo):    SimpleQueue Objects.
                                                             (line    9)
* qualified name:                        Glossary.           (line 1467)
* quantiles() (nel modulo statistics):   Function details.   (line  501)
* quantiles() (statistics.NormalDist metodo): NormalDist objects.
                                                             (line  109)
* quantize() (decimal.Context metodo):   Context objects.    (line  499)
* quantize() (decimal.Decimal metodo):   Decimal objects.    (line  493)
* QueryInfoKey() (nel modulo winreg):    Functions<13>.      (line  319)
* QueryReflectionKey() (nel modulo winreg): Functions<13>.   (line  516)
* QueryValue() (nel modulo winreg):      Functions<13>.      (line  348)
* QueryValueEx() (nel modulo winreg):    Functions<13>.      (line  368)
* QUESTION (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  196)
* Queue (classe in asyncio):             Queue.              (line    6)
* Queue (classe in concurrent.interpreters): Communicating Between Interpreters.
                                                             (line    6)
* Queue (classe in multiprocessing):     Pipes and Queues.   (line   93)
* Queue (classe in queue):               queue — A synchronized queue class.
                                                             (line   34)
* queue (sched.scheduler attributo):     Scheduler Objects.  (line   73)
* Queue() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  200)
* QueueEmpty:                            Exceptions<14>.     (line    6)
* QueueEmptyError:                       Communicating Between Interpreters.
                                                             (line   22)
* QueueFull:                             Exceptions<14>.     (line   11)
* QueueFullError:                        Communicating Between Interpreters.
                                                             (line   28)
* QueueHandler (classe in logging.handlers): QueueHandler.   (line   21)
* QueueListener (classe in logging.handlers): QueueListener. (line   25)
* QueueShutDown:                         Exceptions<14>.     (line   16)
* quick_ratio() (difflib.SequenceMatcher metodo): SequenceMatcher Objects.
                                                             (line  204)
* quiet (sys.flags attributo):           sys — System-specific parameters and functions.
                                                             (line  571)
* quit (pdb command):                    Debugger commands.  (line  441)
* quit (variabile built-in):             Constants added by the site module.
                                                             (line   11)
* quit() (ftplib.FTP metodo):            FTP objects.        (line  361)
* quit() (poplib.POP3 metodo):           POP3 Objects.       (line   83)
* quit() (smtplib.SMTP metodo):          SMTP Objects.       (line  341)
* quit() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line  123)
* quitting (bdb.Bdb attribute):          bdb — Debugger framework.
                                                             (line  363)
* QUOTE_ALL (nel modulo csv):            Module Contents<3>. (line  272)
* quote_from_bytes() (nel modulo urllib.parse): URL Quoting. (line   53)
* QUOTE_MINIMAL (nel modulo csv):        Module Contents<3>. (line  276)
* QUOTE_NONE (nel modulo csv):           Module Contents<3>. (line  296)
* QUOTE_NONNUMERIC (nel modulo csv):     Module Contents<3>. (line  282)
* QUOTE_NOTNULL (nel modulo csv):        Module Contents<3>. (line  309)
* quote_plus() (nel modulo urllib.parse): URL Quoting.       (line   42)
* QUOTE_STRINGS (nel modulo csv):        Module Contents<3>. (line  321)
* quote() (nel modulo email.utils):      email utils Miscellaneous utilities.
                                                             (line   45)
* quote() (nel modulo shlex):            shlex — Simple lexical analysis.
                                                             (line   43)
* quote() (nel modulo urllib.parse):     URL Quoting.        (line   13)
* quoteattr() (nel modulo xml.sax.saxutils): xml sax saxutils — SAX Utilities.
                                                             (line   38)
* quotechar (csv.Dialect attributo):     Dialects and Formatting Parameters.
                                                             (line   64)
* quoted-printable;encoding:             quopri — Encode and decode MIME quoted-printable data.
                                                             (line    8)
* quotes (shlex.shlex attributo):        shlex Objects.      (line  115)
* quoting (csv.Dialect attributo):       Dialects and Formatting Parameters.
                                                             (line   75)
* R_OK (nel modulo os):                  Files and Directories.
                                                             (line  107)
* r';raw string literal:                 Bytes literals.     (line   21)
* r";raw string literal:                 Bytes literals.     (line   20)
* race condition:                        Glossary.           (line 1494)
* radians() (nel modulo math):           Angular conversion. (line   10)
* radians() (nel modulo turtle):         Settings for measurement.
                                                             (line   28)
* radix (sys.float_info attributo):      sys — System-specific parameters and functions.
                                                             (line  700)
* radix() (decimal.Context metodo):      Context objects.    (line  504)
* radix() (decimal.Decimal metodo):      Decimal objects.    (line  522)
* RADIXCHAR (nel modulo locale):         locale — Internationalization services.
                                                             (line  280)
* Raise (classe in ast):                 Statements.         (line  113)
* RAISE (monitoring event):              Events.             (line   82)
* raise an exception:                    Exceptions.         (line    6)
* raise_on_defect (email.policy.Policy attributo): email policy Policy Objects.
                                                             (line  181)
* raise_signal() (nel modulo signal):    Module contents<2>. (line  352)
* RAISE_VARARGS (opcode):                Python Bytecode Instructions.
                                                             (line 1064)
* raiseExceptions (nel modulo logging):  Module-Level Attributes.
                                                             (line   19)
* raising;exception:                     The raise statement.
                                                             (line    6)
* RAND_add() (nel modulo ssl):           Random generation.  (line   30)
* RAND_bytes() (nel modulo ssl):         Random generation.  (line    6)
* RAND_status() (nel modulo ssl):        Random generation.  (line   23)
* randbelow() (nel modulo secrets):      Random numbers.     (line   19)
* randbits() (nel modulo secrets):       Random numbers.     (line   23)
* randbytes() (nel modulo random):       Functions for bytes.
                                                             (line    6)
* randbytes() (random.Random metodo):    Alternative Generator.
                                                             (line   47)
* randint() (nel modulo random):         Functions for integers.
                                                             (line   32)
* Random (classe in random):             Alternative Generator.
                                                             (line    6)
* random command line option; -c:        Command-line usage<2>.
                                                             (line   18)
* random command line option; -choice:   Command-line usage<2>.
                                                             (line   18)
* random command line option; -f:        Command-line usage<2>.
                                                             (line   29)
* random command line option; -float:    Command-line usage<2>.
                                                             (line   29)
* random command line option; -h:        Command-line usage<2>.
                                                             (line   14)
* random command line option; -help:     Command-line usage<2>.
                                                             (line   14)
* random command line option; -i:        Command-line usage<2>.
                                                             (line   23)
* random command line option; -integer:  Command-line usage<2>.
                                                             (line   23)
* random() (nel modulo random):          Real-valued distributions.
                                                             (line   11)
* random() (random.Random metodo):       Alternative Generator.
                                                             (line   34)
* randrange() (nel modulo random):       Functions for integers.
                                                             (line    6)
* range (classe built-in):               Intervalli.         (line   10)
* RARROW (nel modulo token):             token — Constants used with Python parse trees.
                                                             (line  344)
* ratio() (difflib.SequenceMatcher metodo): SequenceMatcher Objects.
                                                             (line  180)
* Rational (classe in numbers):          The numeric tower.  (line   41)
* raw (io.BufferedIOBase attributo):     I/O Base Classes.   (line  252)
* raw_data_manager (nel modulo email.contentmanager): Content Manager Instances.
                                                             (line   11)
* raw_decode() (json.JSONDecoder metodo): Encoders and Decoders.
                                                             (line   95)
* raw_input() (code.InteractiveConsole metodo): Interactive Console Objects.
                                                             (line   45)
* raw() (nel modulo curses):             Functions<5>.       (line  421)
* raw() (pickle.PickleBuffer metodo):    Module Interface.   (line  340)
* RawArray() (nel modulo multiprocessing.sharedctypes): The multiprocessing sharedctypes module.
                                                             (line   16)
* RawConfigParser (classe in configparser): RawConfigParser Objects.
                                                             (line    6)
* RawDescriptionHelpFormatter (classe in argparse): formatter_class.
                                                             (line   10)
* RawIOBase (classe in io):              I/O Base Classes.   (line  170)
* RawPen (classe in turtle):             Public classes.     (line    6)
* RawTextHelpFormatter (classe in argparse): formatter_class.
                                                             (line   10)
* RawTurtle (classe in turtle):          Public classes.     (line    6)
* RawValue() (nel modulo multiprocessing.sharedctypes): The multiprocessing sharedctypes module.
                                                             (line   33)
* RBRACE (nel modulo token):             token — Constants used with Python parse trees.
                                                             (line  269)
* re (re.Match attributo):               Match Objects.      (line  206)
* READ (inspect.BufferFlags attributo):  Buffer flags.       (line   49)
* read_binary() (nel modulo importlib.resources): Functional API.
                                                             (line   75)
* read_byte() (mmap.mmap metodo):        mmap — Memory-mapped file support.
                                                             (line  256)
* read_bytes() (importlib.resources.abc.Traversable metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line  153)
* read_bytes() (pathlib.Path metodo):    Reading and writing files.
                                                             (line   35)
* read_bytes() (zipfile.Path metodo):    Path objects.       (line  110)
* read_dict() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  208)
* read_environ() (nel modulo wsgiref.handlers): wsgiref handlers – server/gateway base classes.
                                                             (line  313)
* read_events() (xml.etree.ElementTree.XMLPullParser metodo): XMLPullParser Objects.
                                                             (line   48)
* read_file() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  186)
* read_history_file() (nel modulo readline): History file.   (line    8)
* read_init_file() (nel modulo readline): Init file.         (line   13)
* read_mime_types() (nel modulo mimetypes): mimetypes — Map filenames to MIME types.
                                                             (line  116)
* READ_RESTRICTED (C macro):             Member flags.       (line   29)
* read_string() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  198)
* read_text() (importlib.resources.abc.Traversable metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line  157)
* read_text() (nel modulo importlib.resources): Functional API.
                                                             (line   89)
* read_text() (pathlib.Path metodo):     Reading and writing files.
                                                             (line   18)
* read_text() (zipfile.Path metodo):     Path objects.       (line   98)
* read_token() (shlex.shlex metodo):     shlex Objects.      (line   20)
* read_windows_registry() (mimetypes.MimeTypes metodo): MimeTypes objects.
                                                             (line   93)
* read() (asyncio.StreamReader metodo):  StreamReader.       (line   20)
* read() (codecs.StreamReader metodo):   StreamReader Objects.
                                                             (line   34)
* read() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  149)
* read() (http.client.HTTPResponse metodo): HTTPResponse Objects.
                                                             (line   13)
* read() (imaplib.IMAP4 metodo):         IMAP4 Objects.      (line  281)
* read() (io.BufferedIOBase metodo):     I/O Base Classes.   (line  273)
* read() (io.BufferedReader metodo):     Buffered Streams.   (line   85)
* read() (io.RawIOBase metodo):          I/O Base Classes.   (line  184)
* read() (io.Reader metodo):             Static Typing.      (line   18)
* read() (io.TextIOBase metodo):         Text I/O<2>.        (line   52)
* read() (mimetypes.MimeTypes metodo):   MimeTypes objects.  (line   77)
* read() (mmap.mmap metodo):             mmap — Memory-mapped file support.
                                                             (line  245)
* read() (nel modulo os):                File Descriptor Operations.
                                                             (line  733)
* read() (sqlite3.Blob metodo):          Blob objects.       (line   45)
* read() (ssl.MemoryBIO metodo):         Memory BIO Support<2>.
                                                             (line  148)
* read() (ssl.SSLSocket metodo):         SSL Sockets.        (line   76)
* read() (urllib.robotparser.RobotFileParser metodo): urllib robotparser — Parser for robots txt.
                                                             (line   25)
* read() (zipfile.ZipFile metodo):       ZipFile objects.    (line  251)
* read1() (bz2.BZ2File metodo):          De compression of files.
                                                             (line  112)
* read1() (io.BufferedIOBase metodo):    I/O Base Classes.   (line  297)
* read1() (io.BufferedReader metodo):    Buffered Streams.   (line   90)
* read1() (io.BytesIO metodo):           Buffered Streams.   (line   44)
* READABLE (nel modulo _tkinter):        File Handlers.      (line   41)
* readable() (bz2.BZ2File metodo):       De compression of files.
                                                             (line   94)
* readable() (io.IOBase metodo):         I/O Base Classes.   (line   78)
* readall() (io.RawIOBase metodo):       I/O Base Classes.   (line  199)
* readbuffer_encode() (nel modulo codecs): codecs — Codec registry and base classes.
                                                             (line  261)
* Reader (classe in io):                 Static Typing.      (line   10)
* reader() (nel modulo csv):             Module Contents<3>. (line    8)
* ReadError:                             tarfile — Read and write tar archive files.
                                                             (line  250)
* readexactly() (asyncio.StreamReader metodo): StreamReader. (line   46)
* readfp() (mimetypes.MimeTypes metodo): MimeTypes objects.  (line   85)
* readframes() (wave.Wave_read metodo):  Wave_read Objects.  (line   52)
* readinto() (bz2.BZ2File metodo):       De compression of files.
                                                             (line  122)
* readinto() (http.client.HTTPResponse metodo): HTTPResponse Objects.
                                                             (line   17)
* readinto() (io.BufferedIOBase metodo): I/O Base Classes.   (line  309)
* readinto() (io.RawIOBase metodo):      I/O Base Classes.   (line  204)
* readinto() (nel modulo os):            File Descriptor Operations.
                                                             (line  754)
* readinto1() (io.BufferedIOBase metodo): I/O Base Classes.  (line  322)
* readinto1() (io.BytesIO metodo):       Buffered Streams.   (line   52)
* readline() (asyncio.StreamReader metodo): StreamReader.    (line   35)
* readline() (codecs.StreamReader metodo): StreamReader Objects.
                                                             (line   60)
* readline() (imaplib.IMAP4 metodo):     IMAP4 Objects.      (line  286)
* readline() (io.IOBase metodo):         I/O Base Classes.   (line   83)
* readline() (io.TextIOBase metodo):     Text I/O<2>.        (line   58)
* readline() (mmap.mmap metodo):         mmap — Memory-mapped file support.
                                                             (line  261)
* readlines() (codecs.StreamReader metodo): StreamReader Objects.
                                                             (line   71)
* readlines() (io.IOBase metodo):        I/O Base Classes.   (line   92)
* readlink() (nel modulo os):            Files and Directories.
                                                             (line  675)
* readlink() (pathlib.Path metodo):      Expanding and resolving paths.
                                                             (line   80)
* readmodule_ex() (nel modulo pyclbr):   pyclbr — Python module browser support.
                                                             (line   31)
* readmodule() (nel modulo pyclbr):      pyclbr — Python module browser support.
                                                             (line   19)
* READONLY (C macro):                    Member flags.       (line   34)
* readonly (memoryview attributo):       Memory Views.       (line  458)
* ReadOnly (nel modulo typing):          Special forms.      (line  276)
* ReadTransport (classe in asyncio):     Transports Hierarchy.
                                                             (line   20)
* readuntil() (asyncio.StreamReader metodo): StreamReader.   (line   55)
* readv() (nel modulo os):               File Descriptor Operations.
                                                             (line  919)
* ready() (multiprocessing.pool.AsyncResult metodo): Process Pools.
                                                             (line  217)
* Real (classe in numbers):              The numeric tower.  (line   28)
* real (numbers.Complex attributo):      The numeric tower.  (line   15)
* real_max_memuse (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  167)
* real_quick_ratio() (difflib.SequenceMatcher metodo): SequenceMatcher Objects.
                                                             (line  209)
* realloc (C function):                  Overview<4>.        (line   33)
* realpath() (nel modulo os.path):       os path — Common pathname manipulations.
                                                             (line  377)
* REALTIME_PRIORITY_CLASS (nel modulo subprocess): Windows Constants.
                                                             (line  103)
* reap_children() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  620)
* reap_threads() (nel modulo test.support.threading_helper): test support threading_helper — Utilities for threading tests.
                                                             (line   17)
* reason (http.client.HTTPResponse attributo): HTTPResponse Objects.
                                                             (line   65)
* reason (ssl.SSLError attributo):       Exceptions<18>.     (line   27)
* reason (UnicodeError attributo):       Concrete exceptions.
                                                             (line  455)
* reason (urllib.error.HTTPError attributo): urllib error — Exception classes raised by urllib request.
                                                             (line   50)
* reason (urllib.error.URLError attributo): urllib error — Exception classes raised by urllib request.
                                                             (line   22)
* reattach() (tkinter.ttk.Treeview metodo): ttk Treeview.    (line  237)
* rebinding;name:                        Assignment statements.
                                                             (line    6)
* recent() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line  291)
* recipients (smtplib.SMTPRecipientsRefused attributo): smtplib — SMTP protocol client.
                                                             (line  164)
* reconfigure() (io.TextIOWrapper metodo): Text I/O<2>.      (line  186)
* record_original_stdout() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  330)
* RECORDS (inspect.BufferFlags attributo): Buffer flags.     (line   41)
* records (unittest.TestCase attributo): Test cases.         (line  451)
* RECORDS_RO (inspect.BufferFlags attributo): Buffer flags.  (line   43)
* rect() (nel modulo cmath):             Conversions to and from polar coordinates.
                                                             (line   44)
* rectangle() (nel modulo curses.textpad): curses textpad — Text input widget for curses programs.
                                                             (line   15)
* RecursionError:                        Concrete exceptions.
                                                             (line  249)
* recursive_repr() (nel modulo reprlib): reprlib — Alternate repr implementation.
                                                             (line   61)
* recv_bytes_into() (multiprocessing.connection.Connection metodo): Connection Objects.
                                                             (line   79)
* recv_bytes() (multiprocessing.connection.Connection metodo): Connection Objects.
                                                             (line   65)
* recv_fds() (nel modulo socket):        Other functions<2>. (line  476)
* recv_into() (socket.socket metodo):    Socket Objects.     (line  390)
* recv() (multiprocessing.connection.Connection metodo): Connection Objects.
                                                             (line   24)
* recv() (socket.socket metodo):         Socket Objects.     (line  234)
* recvfrom_into() (socket.socket metodo): Socket Objects.    (line  380)
* recvfrom() (socket.socket metodo):     Socket Objects.     (line  249)
* recvmsg_into() (socket.socket metodo): Socket Objects.     (line  341)
* recvmsg() (socket.socket metodo):      Socket Objects.     (line  268)
* redirect_request() (urllib.request.HTTPRedirectHandler metodo): HTTPRedirectHandler Objects.
                                                             (line   15)
* redirect_stderr() (nel modulo contextlib): Utilities.      (line  355)
* redirect_stdout() (nel modulo contextlib): Utilities.      (line  315)
* redisplay() (nel modulo readline):     Line buffer.        (line   19)
* redrawln() (curses.window metodo):     Window Objects.     (line  471)
* redrawwin() (curses.window metodo):    Window Objects.     (line  477)
* reduce() (nel modulo functools):       functools — Higher-order functions and operations on callable objects.
                                                             (line  444)
* reducer_override() (pickle.Pickler metodo): Module Interface.
                                                             (line  210)
* reentrant:                             Glossary.           (line 1529)
* ref (classe in weakref):               weakref — Weak references.
                                                             (line   90)
* refcount_test() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  570)
* reference count:                       Glossary.           (line 1506)
* reference counting:                    Objects values and types.
                                                             (line   36)
* ReferenceError:                        Concrete exceptions.
                                                             (line  258)
* ReferenceType (nel modulo weakref):    weakref — Weak references.
                                                             (line  332)
* refold_source (email.policy.EmailPolicy attributo): email policy Policy Objects.
                                                             (line  388)
* refresh() (curses.window metodo):      Window Objects.     (line  482)
* REG_BINARY (nel modulo winreg):        Value Types.        (line    8)
* REG_DWORD (nel modulo winreg):         Value Types.        (line   12)
* REG_DWORD_BIG_ENDIAN (nel modulo winreg): Value Types.     (line   21)
* REG_DWORD_LITTLE_ENDIAN (nel modulo winreg): Value Types.  (line   16)
* REG_EXPAND_SZ (nel modulo winreg):     Value Types.        (line   25)
* REG_FULL_RESOURCE_DESCRIPTOR (nel modulo winreg): Value Types.
                                                             (line   60)
* REG_LINK (nel modulo winreg):          Value Types.        (line   30)
* REG_MULTI_SZ (nel modulo winreg):      Value Types.        (line   34)
* REG_NONE (nel modulo winreg):          Value Types.        (line   39)
* REG_QWORD (nel modulo winreg):         Value Types.        (line   43)
* REG_QWORD_LITTLE_ENDIAN (nel modulo winreg): Value Types.  (line   49)
* REG_RESOURCE_LIST (nel modulo winreg): Value Types.        (line   56)
* REG_RESOURCE_REQUIREMENTS_LIST (nel modulo winreg): Value Types.
                                                             (line   64)
* REG_SZ (nel modulo winreg):            Value Types.        (line   68)
* RegexFlag (classe in re):              Flags.              (line    9)
* register_adapter() (nel modulo sqlite3): Module functions. (line  138)
* register_archive_format() (nel modulo shutil): Archiving operations.
                                                             (line   96)
* register_at_fork() (nel modulo os):    Process Management. (line  561)
* register_callback() (nel modulo sys.monitoring): Registering callback functions.
                                                             (line    6)
* register_converter() (nel modulo sqlite3): Module functions.
                                                             (line  145)
* register_defect() (email.policy.Policy metodo): email policy Policy Objects.
                                                             (line  246)
* register_dialect() (nel modulo csv):   Module Contents<3>. (line   70)
* register_error() (nel modulo codecs):  Error Handlers.     (line  101)
* register_function() (xmlrpc.server.CGIXMLRPCRequestHandler metodo): CGIXMLRPCRequestHandler.
                                                             (line    9)
* register_function() (xmlrpc.server.SimpleXMLRPCServer metodo): SimpleXMLRPCServer Objects.
                                                             (line   10)
* register_instance() (xmlrpc.server.CGIXMLRPCRequestHandler metodo): CGIXMLRPCRequestHandler.
                                                             (line   26)
* register_instance() (xmlrpc.server.SimpleXMLRPCServer metodo): SimpleXMLRPCServer Objects.
                                                             (line   27)
* register_introspection_functions() (xmlrpc.server.CGIXMLRPCRequestHandler metodo): CGIXMLRPCRequestHandler.
                                                             (line   41)
* register_introspection_functions() (xmlrpc.server.SimpleXMLRPCServer metodo): SimpleXMLRPCServer Objects.
                                                             (line   55)
* register_multicall_functions() (xmlrpc.server.CGIXMLRPCRequestHandler metodo): CGIXMLRPCRequestHandler.
                                                             (line   46)
* register_multicall_functions() (xmlrpc.server.SimpleXMLRPCServer metodo): SimpleXMLRPCServer Objects.
                                                             (line   60)
* register_namespace() (nel modulo xml.etree.ElementTree): Functions<8>.
                                                             (line  200)
* register_optionflag() (nel modulo doctest): Option Flags.  (line  154)
* register_shape() (nel modulo turtle):  Settings and special methods.
                                                             (line   71)
* register_unpack_format() (nel modulo shutil): Archiving operations.
                                                             (line  171)
* register() (abc.ABCMeta metodo):       abc — Abstract Base Classes.
                                                             (line   69)
* register() (argparse.ArgumentParser metodo): Registering custom types or actions.
                                                             (line    6)
* register() (functools.singledispatch metodo): functools — Higher-order functions and operations on callable objects.
                                                             (line  494)
* register() (multiprocessing.managers.BaseManager metodo): Managers.
                                                             (line   94)
* register() (nel modulo atexit):        atexit — Exit handlers.
                                                             (line   26)
* register() (nel modulo codecs):        codecs — Codec registry and base classes.
                                                             (line  159)
* register() (nel modulo faulthandler):  Dumping the traceback on a user signal.
                                                             (line    6)
* register() (nel modulo webbrowser):    Command-line interface<6>.
                                                             (line   74)
* register() (select.devpoll metodo):    /dev/poll Polling Objects.
                                                             (line   30)
* register() (select.epoll metodo):      Edge and Level Trigger Polling epoll Objects.
                                                             (line   87)
* register() (select.poll metodo):       Polling Objects.    (line   15)
* register() (selectors.BaseSelector metodo): Classes<3>.    (line   65)
* registerDOMImplementation() (nel modulo xml.dom): Module Contents<4>.
                                                             (line    8)
* registerResult() (nel modulo unittest): Signal Handling.   (line   35)
* REGTYPE (nel modulo tarfile):          tarfile — Read and write tar archive files.
                                                             (line  324)
* regular package:                       Glossary.           (line 1522)
* relative_to() (pathlib.PurePath metodo): Methods and properties.
                                                             (line  316)
* relative;import:                       The import statement.
                                                             (line   99)
* relative;URL:                          urllib parse — Parse URLs into components.
                                                             (line    8)
* release() (_thread.lock metodo):       _thread — Low-level threading API.
                                                             (line  173)
* release() (asyncio.Condition metodo):  Condition.          (line   78)
* release() (asyncio.Lock metodo):       Lock.               (line   49)
* release() (asyncio.Semaphore metodo):  Semaphore.          (line   54)
* release() (logging.Handler metodo):    Handler Objects.    (line   31)
* release() (memoryview metodo):         Memory Views.       (line  256)
* release() (multiprocessing.Lock metodo): Synchronization primitives.
                                                             (line  114)
* release() (multiprocessing.RLock metodo): Synchronization primitives.
                                                             (line  180)
* release() (nel modulo platform):       Cross platform.     (line  117)
* release() (pickle.PickleBuffer metodo): Module Interface.  (line  348)
* release() (threading.Condition metodo): Condition objects. (line   92)
* release() (threading.Lock metodo):     Lock objects.       (line   76)
* release() (threading.RLock metodo):    RLock objects.      (line   94)
* release() (threading.Semaphore metodo): Semaphore objects. (line   64)
* releasebufferproc (C type):            Slot Type typedefs. (line  102)
* reload_environ() (nel modulo os):      Process Parameters. (line   79)
* reload() (nel modulo importlib):       Functions<12>.      (line   56)
* relpath() (nel modulo os.path):        os path — Common pathname manipulations.
                                                             (line  433)
* remainder_near() (decimal.Context metodo): Context objects.
                                                             (line  515)
* remainder_near() (decimal.Decimal metodo): Decimal objects.
                                                             (line  528)
* remainder() (decimal.Context metodo):  Context objects.    (line  508)
* remainder() (nel modulo math):         Floating point arithmetic.
                                                             (line   65)
* remote_exec() (nel modulo sys):        sys — System-specific parameters and functions.
                                                             (line 1924)
* RemoteDisconnected:                    http client — HTTP protocol client.
                                                             (line  188)
* remove_done_callback() (asyncio.Future metodo): Future Object.
                                                             (line  106)
* remove_done_callback() (asyncio.Task metodo): Task Object. (line  111)
* remove_flag() (mailbox.Maildir metodo): Maildir objects.   (line  142)
* remove_flag() (mailbox.MaildirMessage metodo): MaildirMessage objects.
                                                             (line   84)
* remove_flag() (mailbox.mboxMessage metodo): mboxMessage objects.
                                                             (line   85)
* remove_flag() (mailbox.MMDFMessage metodo): MMDFMessage objects.
                                                             (line   84)
* remove_folder() (mailbox.Maildir metodo): Maildir objects. (line   80)
* remove_folder() (mailbox.MH metodo):   MH objects.         (line   50)
* remove_header() (urllib.request.Request metodo): Request Objects.
                                                             (line  100)
* remove_history_item() (nel modulo readline): History list. (line   26)
* remove_label() (mailbox.BabylMessage metodo): BabylMessage objects.
                                                             (line   59)
* remove_option() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  311)
* remove_option() (optparse.OptionParser metodo): Querying and manipulating your option parser.
                                                             (line   47)
* remove_reader() (asyncio.loop metodo): Watching file descriptors.
                                                             (line   15)
* remove_section() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  318)
* remove_sequence() (mailbox.MHMessage metodo): MHMessage objects.
                                                             (line   46)
* remove_signal_handler() (asyncio.loop metodo): Unix signals.
                                                             (line   26)
* remove_writer() (asyncio.loop metodo): Watching file descriptors.
                                                             (line   32)
* remove() (array.array metodo):         array — Efficient arrays of numeric values.
                                                             (line  221)
* remove() (collections.deque metodo):   deque objects.      (line   97)
* remove() (mailbox.Mailbox metodo):     Mailbox objects.    (line   77)
* remove() (mailbox.MH metodo):          MH objects.         (line   79)
* remove() (nel modulo os):              Files and Directories.
                                                             (line  712)
* remove() (sequence metodo):            Tipi di Sequenza Mutabili.
                                                             (line  110)
* remove() (set metodo):                 Tipi di Insiemi — set frozenset.
                                                             (line  211)
* remove() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line  170)
* removeAttribute() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   52)
* removeAttributeNode() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   57)
* removeAttributeNS() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   62)
* removeChild() (xml.dom.Node metodo):   Node Objects.       (line  128)
* removedirs() (nel modulo os):          Files and Directories.
                                                             (line  736)
* removeFilter() (logging.Handler metodo): Handler Objects.  (line   57)
* removeFilter() (logging.Logger metodo): Logger Objects.    (line  331)
* removeHandler() (logging.Logger metodo): Logger Objects.   (line  348)
* removeHandler() (nel modulo unittest): Signal Handling.    (line   52)
* removeprefix() (bytearray metodo):     Operazioni su Bytes e Bytearray.
                                                             (line   54)
* removeprefix() (bytes metodo):         Operazioni su Bytes e Bytearray.
                                                             (line   54)
* removeprefix() (str metodo):           Metodi per le Stringhe.
                                                             (line  533)
* removeResult() (nel modulo unittest):  Signal Handling.    (line   46)
* removesuffix() (bytearray metodo):     Operazioni su Bytes e Bytearray.
                                                             (line   74)
* removesuffix() (bytes metodo):         Operazioni su Bytes e Bytearray.
                                                             (line   74)
* removesuffix() (str metodo):           Metodi per le Stringhe.
                                                             (line  548)
* removexattr() (nel modulo os):         Linux extended attributes.
                                                             (line   41)
* rename() (ftplib.FTP metodo):          FTP objects.        (line  326)
* rename() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line  296)
* rename() (nel modulo os):              Files and Directories.
                                                             (line  753)
* rename() (pathlib.Path metodo):        Copying moving and deleting.
                                                             (line   41)
* renames() (nel modulo os):             Files and Directories.
                                                             (line  790)
* reopenIfNeeded() (logging.handlers.WatchedFileHandler metodo): WatchedFileHandler.
                                                             (line   41)
* reorganize() (dbm.gnu.gdbm metodo):    dbm gnu — GNU database manager.
                                                             (line  117)
* repeat() (nel modulo itertools):       Itertool Functions. (line  531)
* repeat() (nel modulo timeit):          Python Interface.   (line   19)
* repeat() (timeit.Timer metodo):        Python Interface.   (line  113)
* REPL:                                  Glossary.           (line 1549)
* replace_errors() (nel modulo codecs):  Error Handlers.     (line  154)
* replace_header() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  301)
* replace_header() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  412)
* replace_history_item() (nel modulo readline): History list.
                                                             (line   32)
* replace_whitespace (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  188)
* replace;error handler's name:          Error Handlers.     (line   15)
* replace() (bytearray metodo):          Operazioni su Bytes e Bytearray.
                                                             (line  207)
* replace() (bytes metodo):              Operazioni su Bytes e Bytearray.
                                                             (line  207)
* replace() (codeobject metodo):         Methods on code objects.
                                                             (line   85)
* replace() (curses.panel.Panel metodo): Panel Objects.      (line   39)
* replace() (datetime.date metodo):      date Objects.       (line  224)
* replace() (datetime.datetime metodo):  datetime Objects.   (line  464)
* replace() (datetime.time metodo):      time Objects.       (line  167)
* replace() (inspect.Parameter metodo):  Introspecting callables with the Signature object.
                                                             (line  321)
* replace() (inspect.Signature metodo):  Introspecting callables with the Signature object.
                                                             (line  146)
* replace() (nel modulo copy):           copy — Shallow and deep copy operations.
                                                             (line   26)
* replace() (nel modulo dataclasses):    Module contents<4>. (line  446)
* replace() (nel modulo os):             Files and Directories.
                                                             (line  808)
* replace() (pathlib.Path metodo):       Copying moving and deleting.
                                                             (line   69)
* replace() (str metodo):                Metodi per le Stringhe.
                                                             (line  563)
* replace() (tarfile.TarInfo metodo):    TarInfo Objects.    (line  166)
* replaceChild() (xml.dom.Node metodo):  Node Objects.       (line  135)
* ReplacePackage() (nel modulo modulefinder): modulefinder — Find modules used by a script.
                                                             (line   21)
* REPORT_CDIFF (nel modulo doctest):     Option Flags.       (line  113)
* REPORT_ERRMODE (nel modulo msvcrt):    Other Functions.    (line   35)
* report_failure() (doctest.DocTestRunner metodo): DocTestRunner objects.
                                                             (line   76)
* report_full_closure() (filecmp.dircmp metodo): The dircmp class.
                                                             (line   32)
* REPORT_NDIFF (nel modulo doctest):     Option Flags.       (line  118)
* REPORT_ONLY_FIRST_FAILURE (nel modulo doctest): Option Flags.
                                                             (line  127)
* report_partial_closure() (filecmp.dircmp metodo): The dircmp class.
                                                             (line   27)
* report_start() (doctest.DocTestRunner metodo): DocTestRunner objects.
                                                             (line   54)
* report_success() (doctest.DocTestRunner metodo): DocTestRunner objects.
                                                             (line   65)
* REPORT_UDIFF (nel modulo doctest):     Option Flags.       (line  108)
* report_unexpected_exception() (doctest.DocTestRunner metodo): DocTestRunner objects.
                                                             (line   87)
* report() (filecmp.dircmp metodo):      The dircmp class.   (line   22)
* report() (modulefinder.ModuleFinder metodo): modulefinder — Find modules used by a script.
                                                             (line   38)
* REPORTING_FLAGS (nel modulo doctest):  Option Flags.       (line  146)
* Repr (classe in reprlib):              reprlib — Alternate repr implementation.
                                                             (line   17)
* repr() (built-in function);__repr__() (object method): Basic customization.
                                                             (line  114)
* repr() (nel modulo reprlib):           reprlib — Alternate repr implementation.
                                                             (line   51)
* repr() (reprlib.Repr metodo):          Repr Objects.       (line  107)
* repr1() (reprlib.Repr metodo):         Repr Objects.       (line  112)
* ReprEnum (classe in enum):             Data Types<2>.      (line  596)
* reprfunc (C type):                     Slot Type typedefs. (line   39)
* Request (classe in urllib.request):    urllib request — Extensible library for opening URLs.
                                                             (line  231)
* request (socketserver.BaseRequestHandler attributo): Request Handler Objects.
                                                             (line   42)
* request_queue_size (socketserver.BaseServer attributo): Server Objects<2>.
                                                             (line  102)
* request_rate() (urllib.robotparser.RobotFileParser metodo): urllib robotparser — Parser for robots txt.
                                                             (line   60)
* request_uri() (nel modulo wsgiref.util): wsgiref util – WSGI environment utilities.
                                                             (line   27)
* request_version (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  151)
* request() (http.client.HTTPConnection metodo): HTTPConnection Objects.
                                                             (line    8)
* RequestHandlerClass (socketserver.BaseServer attributo): Server Objects<2>.
                                                             (line   75)
* requestline (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  133)
* Required (nel modulo typing):          Special forms.      (line  257)
* requires_bz2() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  529)
* requires_docstrings() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  541)
* requires_freebsd_version() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  497)
* requires_gil_enabled() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  512)
* requires_gzip() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  525)
* requires_IEEE_754() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  517)
* requires_limited_api() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  545)
* requires_linux_version() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  502)
* requires_lzma() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  533)
* requires_mac_version() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  507)
* requires_resource() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  537)
* requires_zlib() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  521)
* requires() (nel modulo importlib.metadata): Distribution requirements.
                                                             (line    6)
* requires() (nel modulo test.support):  test support — Utilities for the Python test suite.
                                                             (line  281)
* RERAISE (monitoring event):            Events.             (line   87)
* RERAISE (opcode):                      Python Bytecode Instructions.
                                                             (line  443)
* reschedule() (asyncio.Timeout metodo): Timeouts.           (line   68)
* reserved (zipfile.ZipInfo attributo):  ZipInfo objects.    (line  126)
* reserved word:                         Keywords.           (line    6)
* RESERVED_FUTURE (nel modulo uuid):     uuid — UUID objects according to RFC 9562.
                                                             (line  311)
* RESERVED_MICROSOFT (nel modulo uuid):  uuid — UUID objects according to RFC 9562.
                                                             (line  307)
* RESERVED_NCS (nel modulo uuid):        uuid — UUID objects according to RFC 9562.
                                                             (line  297)
* reset_mock() (unittest.mock.AsyncMock metodo): The Mock Class.
                                                             (line  896)
* reset_mock() (unittest.mock.Mock metodo): The Mock Class.  (line  202)
* reset_peak() (nel modulo tracemalloc): Functions<10>.      (line   38)
* reset_prog_mode() (nel modulo curses): Functions<5>.       (line  427)
* reset_shell_mode() (nel modulo curses): Functions<5>.      (line  432)
* reset_tzpath() (nel modulo zoneinfo):  Functions<2>.       (line   27)
* reset() (asyncio.Barrier metodo):      Barrier.            (line   78)
* reset() (bdb.Bdb metodo):              bdb — Debugger framework.
                                                             (line  185)
* reset() (codecs.IncrementalDecoder metodo): IncrementalDecoder Objects.
                                                             (line   40)
* reset() (codecs.IncrementalEncoder metodo): IncrementalEncoder Objects.
                                                             (line   35)
* reset() (codecs.StreamReader metodo):  StreamReader Objects.
                                                             (line   83)
* reset() (codecs.StreamWriter metodo):  StreamWriter Objects.
                                                             (line   42)
* reset() (contextvars.ContextVar metodo): Context Variables.
                                                             (line   84)
* reset() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line   23)
* reset() (nel modulo turtle):           More drawing control.
                                                             (line    6)
* reset() (threading.Barrier metodo):    Barrier objects.    (line   71)
* reset() (xml.dom.pulldom.DOMEventStream metodo): DOMEventStream Objects.
                                                             (line   37)
* reset() (xml.sax.xmlreader.IncrementalParser metodo): IncrementalParser Objects.
                                                             (line   19)
* resetbuffer() (code.InteractiveConsole metodo): Interactive Console Objects.
                                                             (line   41)
* resetscreen() (nel modulo turtle):     Window control.     (line   86)
* resetty() (nel modulo curses):         Functions<5>.       (line  437)
* resetwarnings() (nel modulo warnings): Available Functions.
                                                             (line  134)
* resize_term() (nel modulo curses):     Functions<5>.       (line  442)
* resize() (bytearray metodo):           Oggetti Bytearray.  (line   76)
* resize() (curses.window metodo):       Window Objects.     (line  501)
* resize() (mmap.mmap metodo):           mmap — Memory-mapped file support.
                                                             (line  267)
* resize() (nel modulo ctypes):          Utility functions.  (line  237)
* resizemode() (nel modulo turtle):      Appearance.         (line   24)
* resizeterm() (nel modulo curses):      Functions<5>.       (line  452)
* resolution (datetime.date attributo):  date Objects.       (line  139)
* resolution (datetime.datetime attributo): datetime Objects.
                                                             (line  298)
* resolution (datetime.time attributo):  time Objects.       (line   42)
* resolution (datetime.timedelta attributo): timedelta Objects.
                                                             (line   99)
* resolve_bases() (nel modulo types):    Dynamic Type Creation.
                                                             (line   58)
* resolve_name() (nel modulo importlib.util): importlib util – Utility code for importers.
                                                             (line   80)
* resolve_name() (nel modulo pkgutil):   pkgutil — Package extension utility.
                                                             (line  173)
* resolve() (pathlib.Path metodo):       Expanding and resolving paths.
                                                             (line   49)
* resolveEntity() (xml.sax.handler.EntityResolver metodo): EntityResolver Objects.
                                                             (line    6)
* resource_path() (importlib.resources.abc.ResourceReader metodo): importlib resources abc – Abstract base classes for resources.
                                                             (line   55)
* ResourceDenied:                        test support — Utilities for the Python test suite.
                                                             (line   22)
* ResourceLoader (classe in importlib.abc): importlib abc – Abstract base classes related to import.
                                                             (line  175)
* ResourceReader (classe in importlib.resources.abc): importlib resources abc – Abstract base classes for resources.
                                                             (line   12)
* ResourceWarning:                       Warnings.           (line   85)
* response() (imaplib.IMAP4 metodo):     IMAP4 Objects.      (line  300)
* ResponseNotReady:                      http client — HTTP protocol client.
                                                             (line  174)
* responses (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  226)
* responses (nel modulo http.client):    http client — HTTP protocol client.
                                                             (line  209)
* restart (pdb command):                 Debugger commands.  (line  428)
* restart_events() (bdb.Bdb metodo):     bdb — Debugger framework.
                                                             (line  440)
* restart_events() (nel modulo sys.monitoring): Disabling events.
                                                             (line   25)
* restore() (nel modulo difflib):        difflib — Helpers for computing deltas.
                                                             (line  271)
* restore() (test.support.SaveSignals metodo): test support — Utilities for the Python test suite.
                                                             (line  811)
* RESTRICTED (C macro):                  Member flags.       (line   29)
* restricted;execution:                  Builtins and restricted execution.
                                                             (line    6)
* restype (ctypes._CFuncPtr attributo):  Foreign functions.  (line   32)
* result() (asyncio.Future metodo):      Future Object.      (line   32)
* result() (asyncio.Task metodo):        Task Object.        (line   73)
* result() (concurrent.futures.Future metodo): Future Objects.
                                                             (line   37)
* results() (trace.Trace metodo):        Programmatic Interface.
                                                             (line   40)
* RESUME (opcode):                       Python Bytecode Instructions.
                                                             (line 1276)
* resume_reading() (asyncio.ReadTransport metodo): Read-only Transports.
                                                             (line   21)
* resume_writing() (asyncio.BaseProtocol metodo): Base Protocol.
                                                             (line   44)
* retr() (poplib.POP3 metodo):           POP3 Objects.       (line   63)
* retrbinary() (ftplib.FTP metodo):      FTP objects.        (line  176)
* retrlines() (ftplib.FTP metodo):       FTP objects.        (line  201)
* RETRY (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  149)
* RETRYCANCEL (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  176)
* Return (classe in ast):                Function and class definitions.
                                                             (line  114)
* return (pdb command):                  Debugger commands.  (line  233)
* return_annotation (inspect.Signature attributo): Introspecting callables with the Signature object.
                                                             (line  125)
* RETURN_GENERATOR (opcode):             Python Bytecode Instructions.
                                                             (line 1301)
* return_ok() (http.cookiejar.CookiePolicy metodo): CookiePolicy Objects.
                                                             (line   18)
* RETURN_VALUE (opcode):                 Python Bytecode Instructions.
                                                             (line  410)
* return_value (unittest.mock.Mock attributo): The Mock Class.
                                                             (line  344)
* returncode (asyncio.subprocess.Process attributo): Interacting with Subprocesses.
                                                             (line  146)
* returncode (subprocess.CalledProcessError attributo): Using the subprocess Module.
                                                             (line  212)
* returncode (subprocess.CompletedProcess attributo): Using the subprocess Module.
                                                             (line  111)
* returncode (subprocess.Popen attributo): Popen Objects.    (line  157)
* retval (pdb command):                  Debugger commands.  (line  462)
* reveal_type() (nel modulo typing):     Functions and decorators.
                                                             (line   82)
* reverse_order() (pstats.Stats metodo): The Stats Class.    (line  157)
* reverse_pointer (ipaddress.IPv4Address attributo): Address objects.
                                                             (line   81)
* reverse_pointer (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  273)
* reverse() (array.array metodo):        array — Efficient arrays of numeric values.
                                                             (line  231)
* reverse() (collections.deque metodo):  deque objects.      (line  102)
* reverse() (sequence metodo):           Tipi di Sequenza Mutabili.
                                                             (line  117)
* Reversible (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   49)
* Reversible (classe in typing):         Aliases to other ABCs in collections abc.
                                                             (line   61)
* revert() (http.cookiejar.FileCookieJar metodo): CookieJar and FileCookieJar Objects.
                                                             (line  142)
* rewind() (wave.Wave_read metodo):      Wave_read Objects.  (line   57)
* RFC_4122 (nel modulo uuid):            uuid — UUID objects according to RFC 9562.
                                                             (line  301)
* RFC; RFC 1123:                         Functions<4>.       (line  750)
* RFC; RFC 1123 <1>:                     Functions<4>.       (line  763)
* RFC; RFC 1123 <2>:                     Functions<4>.       (line  780)
* RFC; RFC 1321:                         hashlib — Secure hashes and message digests.
                                                             (line   15)
* RFC; RFC 1422:                         Certificates.       (line   38)
* RFC; RFC 1422 <1>:                     TLS 1 3.            (line   41)
* RFC; RFC 1494:                         mimetypes.          (line   39)
* RFC; RFC 1521:                         Security Considerations<2>.
                                                             (line   18)
* RFC; RFC 1521 <1>:                     quopri — Encode and decode MIME quoted-printable data.
                                                             (line   11)
* RFC; RFC 1521 <2>:                     quopri — Encode and decode MIME quoted-printable data.
                                                             (line   37)
* RFC; RFC 1522:                         binascii — Convert between binary and ASCII.
                                                             (line   86)
* RFC; RFC 1522 <1>:                     quopri — Encode and decode MIME quoted-printable data.
                                                             (line   25)
* RFC; RFC 1522 <2>:                     quopri — Encode and decode MIME quoted-printable data.
                                                             (line   39)
* RFC; RFC 1730:                         imaplib — IMAP4 protocol client.
                                                             (line   14)
* RFC; RFC 1738:                         URL Quoting.        (line  192)
* RFC; RFC 1750:                         Random generation.  (line   34)
* RFC; RFC 1808:                         urllib<4>.          (line   23)
* RFC; RFC 1808 <1>:                     urllib parse — Parse URLs into components.
                                                             (line   34)
* RFC; RFC 1808 <2>:                     URL Parsing.        (line   42)
* RFC; RFC 1808 <3>:                     URL Quoting.        (line  186)
* RFC; RFC 1869:                         smtplib — SMTP protocol client.
                                                             (line   13)
* RFC; RFC 1869 <1>:                     smtplib — SMTP protocol client.
                                                             (line  202)
* RFC; RFC 1870:                         smtpd<4>.           (line    6)
* RFC; RFC 1939:                         poplib — POP3 protocol client.
                                                             (line   11)
* RFC; RFC 1939 <1>:                     poplib — POP3 protocol client.
                                                             (line   13)
* RFC; RFC 2033:                         New and Improved Modules<2>.
                                                             (line  568)
* RFC; RFC 2045:                         email — An email and MIME handling package.
                                                             (line   15)
* RFC; RFC 2045 <1>:                     email message Representing an email message.
                                                             (line  316)
* RFC; RFC 2045 <2>:                     email message Representing an email message.
                                                             (line  318)
* RFC; RFC 2045 <3>:                     email message Representing an email message.
                                                             (line  321)
* RFC; RFC 2045 <4>:                     email headerregistry Custom Header Objects.
                                                             (line  239)
* RFC; RFC 2045 <5>:                     email headerregistry Custom Header Objects.
                                                             (line  297)
* RFC; RFC 2045 <6>:                     email message Message Representing an email message using the compat32 API.
                                                             (line  425)
* RFC; RFC 2045 <7>:                     email message Message Representing an email message using the compat32 API.
                                                             (line  429)
* RFC; RFC 2045 <8>:                     email message Message Representing an email message using the compat32 API.
                                                             (line  432)
* RFC; RFC 2045 <9>:                     email message Message Representing an email message using the compat32 API.
                                                             (line  529)
* RFC; RFC 2045 <10>:                    email header Internationalized headers.
                                                             (line   31)
* RFC; RFC 2045 <11>:                    base64 — Base16 Base32 Base64 Base85 Data Encodings.
                                                             (line   24)
* RFC; RFC 2045 <12>:                    base64 — Base16 Base32 Base64 Base85 Data Encodings.
                                                             (line   25)
* RFC; RFC 2045 <13>:                    Legacy Interface.   (line   29)
* RFC; RFC 2045 <14>:                    Legacy Interface.   (line   37)
* RFC; RFC 2045 Section 6.8:             Binary Objects.     (line   31)
* RFC; RFC 2046:                         email — An email and MIME handling package.
                                                             (line   15)
* RFC; RFC 2046 <1>:                     Content Manager Instances.
                                                             (line   93)
* RFC; RFC 2046 <2>:                     email header Internationalized headers.
                                                             (line   32)
* RFC; RFC 2047:                         PEP 3333 Python Web Server Gateway Interface v1 0 1.
                                                             (line   21)
* RFC; RFC 2047 <1>:                     email<7>.           (line   27)
* RFC; RFC 2047 <2>:                     email — An email and MIME handling package.
                                                             (line   16)
* RFC; RFC 2047 <3>:                     email policy Policy Objects.
                                                             (line  364)
* RFC; RFC 2047 <4>:                     email policy Policy Objects.
                                                             (line  370)
* RFC; RFC 2047 <5>:                     email headerregistry Custom Header Objects.
                                                             (line   78)
* RFC; RFC 2047 <6>:                     email headerregistry Custom Header Objects.
                                                             (line  123)
* RFC; RFC 2047 <7>:                     email headerregistry Custom Header Objects.
                                                             (line  128)
* RFC; RFC 2047 <8>:                     email header Internationalized headers.
                                                             (line   32)
* RFC; RFC 2047 <9>:                     email header Internationalized headers.
                                                             (line   55)
* RFC; RFC 2047 <10>:                    email header Internationalized headers.
                                                             (line  117)
* RFC; RFC 2047 <11>:                    email header Internationalized headers.
                                                             (line  141)
* RFC; RFC 2047 <12>:                    email utils Miscellaneous utilities.
                                                             (line   78)
* RFC; RFC 2060:                         imaplib — IMAP4 protocol client.
                                                             (line   13)
* RFC; RFC 2060 <1>:                     IMAP4 Objects.      (line  398)
* RFC; RFC 2068:                         http cookies — HTTP state management.
                                                             (line   16)
* RFC; RFC 2104:                         hmac.               (line    6)
* RFC; RFC 2104 <1>:                     New and Improved Modules<3>.
                                                             (line   35)
* RFC; RFC 2104 <2>:                     Library<28>.        (line    6)
* RFC; RFC 2104 <3>:                     hmac — Keyed-Hashing for Message Authentication.
                                                             (line   10)
* RFC; RFC 2109:                         http cookies — HTTP state management.
                                                             (line   15)
* RFC; RFC 2109 <1>:                     http cookies — HTTP state management.
                                                             (line   37)
* RFC; RFC 2109 <2>:                     http cookies — HTTP state management.
                                                             (line   68)
* RFC; RFC 2109 <3>:                     Morsel Objects.     (line    8)
* RFC; RFC 2109 <4>:                     Morsel Objects.     (line   11)
* RFC; RFC 2109 <5>:                     Morsel Objects.     (line  109)
* RFC; RFC 2109 <6>:                     Morsel Objects.     (line  122)
* RFC; RFC 2109 <7>:                     http cookiejar — Cookie handling for HTTP clients.
                                                             (line   18)
* RFC; RFC 2109 <8>:                     http cookiejar — Cookie handling for HTTP clients.
                                                             (line  103)
* RFC; RFC 2109 <9>:                     http cookiejar — Cookie handling for HTTP clients.
                                                             (line  115)
* RFC; RFC 2109 <10>:                    http cookiejar — Cookie handling for HTTP clients.
                                                             (line  142)
* RFC; RFC 2109 <11>:                    DefaultCookiePolicy Objects.
                                                             (line   86)
* RFC; RFC 2109 <12>:                    Cookie Objects<2>.  (line   11)
* RFC; RFC 2109 <13>:                    Cookie Objects<2>.  (line   23)
* RFC; RFC 2109 <14>:                    Cookie Objects<2>.  (line   74)
* RFC; RFC 2177:                         imaplib.            (line    7)
* RFC; RFC 2177 <1>:                     IMAP4 Objects.      (line  129)
* RFC; RFC 2183:                         email — An email and MIME handling package.
                                                             (line   16)
* RFC; RFC 2183 <1>:                     email message Representing an email message.
                                                             (line  460)
* RFC; RFC 2183 <2>:                     email message Message Representing an email message using the compat32 API.
                                                             (line  636)
* RFC; RFC 2231:                         Library<18>.        (line   68)
* RFC; RFC 2231 <1>:                     Library<54>.        (line  135)
* RFC; RFC 2231 <2>:                     email — An email and MIME handling package.
                                                             (line   16)
* RFC; RFC 2231 <3>:                     email message Representing an email message.
                                                             (line  280)
* RFC; RFC 2231 <4>:                     email message Representing an email message.
                                                             (line  283)
* RFC; RFC 2231 <5>:                     email message Representing an email message.
                                                             (line  365)
* RFC; RFC 2231 <6>:                     email message Message Representing an email message using the compat32 API.
                                                             (line  388)
* RFC; RFC 2231 <7>:                     email message Message Representing an email message using the compat32 API.
                                                             (line  392)
* RFC; RFC 2231 <8>:                     email message Message Representing an email message using the compat32 API.
                                                             (line  494)
* RFC; RFC 2231 <9>:                     email message Message Representing an email message using the compat32 API.
                                                             (line  502)
* RFC; RFC 2231 <10>:                    email message Message Representing an email message using the compat32 API.
                                                             (line  536)
* RFC; RFC 2231 <11>:                    email header Internationalized headers.
                                                             (line   32)
* RFC; RFC 2231 <12>:                    email utils Miscellaneous utilities.
                                                             (line  189)
* RFC; RFC 2231 <13>:                    email utils Miscellaneous utilities.
                                                             (line  194)
* RFC; RFC 2231 <14>:                    email utils Miscellaneous utilities.
                                                             (line  203)
* RFC; RFC 2231 <15>:                    email utils Miscellaneous utilities.
                                                             (line  210)
* RFC; RFC 2231 <16>:                    email utils Miscellaneous utilities.
                                                             (line  219)
* RFC; RFC 2295:                         HTTP status codes.  (line  184)
* RFC; RFC 2324:                         HTTP status codes.  (line  133)
* RFC; RFC 2342:                         New and Improved Modules<3>.
                                                             (line   94)
* RFC; RFC 2342 <1>:                     IMAP4 Objects.      (line  246)
* RFC; RFC 2361:                         mimetypes.          (line   57)
* RFC; RFC 2368:                         URL Quoting.        (line  182)
* RFC; RFC 2373:                         Address objects.    (line   99)
* RFC; RFC 2373 <1>:                     Address objects.    (line  165)
* RFC; RFC 2373 <2>:                     Address objects.    (line  185)
* RFC; RFC 2396:                         urllib parse<5>.    (line    6)
* RFC; RFC 2396 <1>:                     urllib<4>.          (line   24)
* RFC; RFC 2396 <2>:                     URL Parsing.        (line  264)
* RFC; RFC 2396 <3>:                     URL Quoting.        (line   25)
* RFC; RFC 2396 <4>:                     URL Quoting.        (line  177)
* RFC; RFC 2397:                         DataHandler Objects.
                                                             (line    9)
* RFC; RFC 2449:                         POP3 Objects.       (line   26)
* RFC; RFC 2487:                         New and Improved Modules<3>.
                                                             (line   86)
* RFC; RFC 2518:                         HTTP status codes.  (line   19)
* RFC; RFC 2595:                         poplib — POP3 protocol client.
                                                             (line   14)
* RFC; RFC 2595 <1>:                     POP3 Objects.       (line  116)
* RFC; RFC 2616:                         PEP 3333 Python Web Server Gateway Interface v1 0 1.
                                                             (line   20)
* RFC; RFC 2616 <1>:                     wsgiref util – WSGI environment utilities.
                                                             (line  115)
* RFC; RFC 2616 <2>:                     wsgiref validate — WSGI conformance checker.
                                                             (line   27)
* RFC; RFC 2616 <3>:                     HTTPRedirectHandler Objects.
                                                             (line    8)
* RFC; RFC 2616 <4>:                     HTTPRedirectHandler Objects.
                                                             (line   28)
* RFC; RFC 2616 <5>:                     urllib error — Exception classes raised by urllib request.
                                                             (line   45)
* RFC; RFC 2616 <6>:                     Introduction<16>.   (line   34)
* RFC; RFC 2616 <7>:                     HTTPError.          (line   15)
* RFC; RFC 2616 <8>:                     Error Codes.        (line   11)
* RFC; RFC 2616 Section 14.23:           HTTPConnection Objects.
                                                             (line   31)
* RFC; RFC 2616 Section 5.1.2:           HTTPConnection Objects.
                                                             (line   13)
* RFC; RFC 2616 Section 5.1.2 <1>:       HTTPConnection Objects.
                                                             (line   32)
* RFC; RFC 2640:                         Changes in the Python API<4>.
                                                             (line   36)
* RFC; RFC 2640 <1>:                     Tests<45>.          (line   22)
* RFC; RFC 2640 <2>:                     ftplib — FTP protocol client.
                                                             (line   18)
* RFC; RFC 2640 <3>:                     FTP objects.        (line   64)
* RFC; RFC 2640 <4>:                     FTP_TLS objects.    (line   64)
* RFC; RFC 2732:                         urllib parse<6>.    (line   10)
* RFC; RFC 2732 <1>:                     New and Improved Modules.
                                                             (line  644)
* RFC; RFC 2732 <2>:                     URL Quoting.        (line  173)
* RFC; RFC 2774:                         HTTP status codes.  (line  193)
* RFC; RFC 2818:                         ssl<13>.            (line   16)
* RFC; RFC 2821:                         email — An email and MIME handling package.
                                                             (line   12)
* RFC; RFC 2822:                         New and Improved Modules<3>.
                                                             (line   98)
* RFC; RFC 2822 <1>:                     Functions<4>.       (line  752)
* RFC; RFC 2822 <2>:                     Functions<4>.       (line  765)
* RFC; RFC 2822 <3>:                     Functions<4>.       (line  782)
* RFC; RFC 2822 <4>:                     email message Message Representing an email message using the compat32 API.
                                                             (line  278)
* RFC; RFC 2822 <5>:                     email header Internationalized headers.
                                                             (line   20)
* RFC; RFC 2822 <6>:                     email header Internationalized headers.
                                                             (line   23)
* RFC; RFC 2822 <7>:                     email header Internationalized headers.
                                                             (line   31)
* RFC; RFC 2822 <8>:                     email header Internationalized headers.
                                                             (line   88)
* RFC; RFC 2822 <9>:                     email header Internationalized headers.
                                                             (line  116)
* RFC; RFC 2822 <10>:                    email header Internationalized headers.
                                                             (line  134)
* RFC; RFC 2822 <11>:                    email utils Miscellaneous utilities.
                                                             (line   29)
* RFC; RFC 2822 <12>:                    email utils Miscellaneous utilities.
                                                             (line  109)
* RFC; RFC 2822 <13>:                    email utils Miscellaneous utilities.
                                                             (line  112)
* RFC; RFC 2822 <14>:                    email utils Miscellaneous utilities.
                                                             (line  237)
* RFC; RFC 2822 <15>:                    email utils Miscellaneous utilities.
                                                             (line  155)
* RFC; RFC 2964:                         http cookiejar — Cookie handling for HTTP clients.
                                                             (line  155)
* RFC; RFC 2965:                         urllib request — Extensible library for opening URLs.
                                                             (line  276)
* RFC; RFC 2965 <1>:                     urllib request — Extensible library for opening URLs.
                                                             (line  284)
* RFC; RFC 2965 <2>:                     Request Objects.    (line   50)
* RFC; RFC 2965 <3>:                     http cookiejar — Cookie handling for HTTP clients.
                                                             (line   16)
* RFC; RFC 2965 <4>:                     http cookiejar — Cookie handling for HTTP clients.
                                                             (line  103)
* RFC; RFC 2965 <5>:                     http cookiejar — Cookie handling for HTTP clients.
                                                             (line  115)
* RFC; RFC 2965 <6>:                     http cookiejar — Cookie handling for HTTP clients.
                                                             (line  144)
* RFC; RFC 2965 <7>:                     http cookiejar — Cookie handling for HTTP clients.
                                                             (line  146)
* RFC; RFC 2965 <8>:                     http cookiejar — Cookie handling for HTTP clients.
                                                             (line  153)
* RFC; RFC 2965 <9>:                     FileCookieJar subclasses and co-operation with web browsers.
                                                             (line   16)
* RFC; RFC 2965 <10>:                    CookiePolicy Objects.
                                                             (line   74)
* RFC; RFC 2965 <11>:                    CookiePolicy Objects.
                                                             (line   79)
* RFC; RFC 2965 <12>:                    DefaultCookiePolicy Objects.
                                                             (line    8)
* RFC; RFC 2965 <13>:                    DefaultCookiePolicy Objects.
                                                             (line   90)
* RFC; RFC 2965 <14>:                    DefaultCookiePolicy Objects.
                                                             (line  101)
* RFC; RFC 2965 <15>:                    DefaultCookiePolicy Objects.
                                                             (line  105)
* RFC; RFC 2965 <16>:                    DefaultCookiePolicy Objects.
                                                             (line  114)
* RFC; RFC 2965 <17>:                    DefaultCookiePolicy Objects.
                                                             (line  151)
* RFC; RFC 2965 <18>:                    Cookie Objects<2>.  (line   23)
* RFC; RFC 2965 <19>:                    Examples<30>.       (line   25)
* RFC; RFC 3056:                         Address objects.    (line  320)
* RFC; RFC 3164:                         Logging to syslog with RFC5424 support.
                                                             (line    7)
* RFC; RFC 3171:                         Address objects.    (line   98)
* RFC; RFC 3207:                         New and Improved Modules<2>.
                                                             (line  573)
* RFC; RFC 3229:                         HTTP status codes.  (line   52)
* RFC; RFC 3280:                         SSL Sockets.        (line  161)
* RFC; RFC 3330:                         Address objects.    (line  184)
* RFC; RFC 3339:                         Displaying the date/time in messages.
                                                             (line   18)
* RFC; RFC 3362:                         mimetypes.          (line   41)
* RFC; RFC 3454:                         Security<26>.       (line   19)
* RFC; RFC 3454 <1>:                     stringprep — Internet String Preparation.
                                                             (line   17)
* RFC; RFC 3454 <2>:                     stringprep — Internet String Preparation.
                                                             (line   26)
* RFC; RFC 3490:                         Text Encodings.     (line   14)
* RFC; RFC 3490 <1>:                     encodings idna — Internationalized Domain Names in Applications.
                                                             (line    6)
* RFC; RFC 3490 <2>:                     encodings idna — Internationalized Domain Names in Applications.
                                                             (line   57)
* RFC; RFC 3490 <3>:                     encodings idna — Internationalized Domain Names in Applications.
                                                             (line   62)
* RFC; RFC 3490 Section 3.1:             encodings idna — Internationalized Domain Names in Applications.
                                                             (line   27)
* RFC; RFC 3491:                         Security<26>.       (line   21)
* RFC; RFC 3492:                         Text Encodings.     (line   36)
* RFC; RFC 3492 <1>:                     encodings idna — Internationalized Domain Names in Applications.
                                                             (line    7)
* RFC; RFC 3493:                         Example<7>.         (line  227)
* RFC; RFC 3501:                         IMAP4 Objects.      (line  409)
* RFC; RFC 3542:                         Library<161>.       (line  351)
* RFC; RFC 3542 <1>:                     Other functions<2>. (line  341)
* RFC; RFC 3548:                         New Improved and Deprecated Modules<3>.
                                                             (line   16)
* RFC; RFC 3548 <1>:                     binascii — Convert between binary and ASCII.
                                                             (line   50)
* RFC; RFC 3548 <2>:                     binascii — Convert between binary and ASCII.
                                                             (line   65)
* RFC; RFC 3596 Section 2.5:             Library<45>.        (line  340)
* RFC; RFC 3659:                         FTP objects.        (line  290)
* RFC; RFC 3745:                         mimetypes.          (line   43)
* RFC; RFC 3879:                         Address objects.    (line  180)
* RFC; RFC 3879 <1>:                     Address objects.    (line  298)
* RFC; RFC 3927:                         Address objects.    (line  189)
* RFC; RFC 3950:                         mimetypes.          (line   46)
* RFC; RFC 3986:                         urllib parse.       (line   17)
* RFC; RFC 3986 <1>:                     urllib parse<3>.    (line    7)
* RFC; RFC 3986 <2>:                     urllib parse<4>.    (line    7)
* RFC; RFC 3986 <3>:                     urllib parse<5>.    (line    6)
* RFC; RFC 3986 <4>:                     urllib<4>.          (line   22)
* RFC; RFC 3986 <5>:                     New and Improved Modules.
                                                             (line  623)
* RFC; RFC 3986 <6>:                     Porting to Python 2 7.
                                                             (line   80)
* RFC; RFC 3986 <7>:                     Library<41>.        (line  197)
* RFC; RFC 3986 <8>:                     urllib parse — Parse URLs into components.
                                                             (line   35)
* RFC; RFC 3986 <9>:                     URL Parsing.        (line  143)
* RFC; RFC 3986 <10>:                    URL Parsing.        (line  383)
* RFC; RFC 3986 <11>:                    URL parsing security.
                                                             (line   25)
* RFC; RFC 3986 <12>:                    URL Quoting.        (line   25)
* RFC; RFC 3986 <13>:                    URL Quoting.        (line  165)
* RFC; RFC 3986 <14>:                    http server — HTTP servers.
                                                             (line  148)
* RFC; RFC 4007:                         Address objects.    (line  241)
* RFC; RFC 4007 <1>:                     Address objects.    (line  312)
* RFC; RFC 4047:                         mimetypes.          (line   49)
* RFC; RFC 4086:                         TLS 1 3.            (line   45)
* RFC; RFC 4122:                         New Improved and Removed Modules.
                                                             (line  416)
* RFC; RFC 4122 <1>:                     New Improved and Removed Modules.
                                                             (line  421)
* RFC; RFC 4122 <2>:                     uuid — UUID objects according to RFC 9562.
                                                             (line   15)
* RFC; RFC 4122 <3>:                     uuid — UUID objects according to RFC 9562.
                                                             (line  183)
* RFC; RFC 4122 <4>:                     uuid — UUID objects according to RFC 9562.
                                                             (line  303)
* RFC; RFC 4122 <5>:                     uuid — UUID objects according to RFC 9562.
                                                             (line  304)
* RFC; RFC 4180:                         csv — CSV File Reading and Writing.
                                                             (line   13)
* RFC; RFC 4193:                         Address objects.    (line  300)
* RFC; RFC 4217:                         FTP_TLS objects.    (line   11)
* RFC; RFC 4291:                         Library<63>.        (line 1075)
* RFC; RFC 4291 <1>:                     Library<115>.       (line  653)
* RFC; RFC 4291 <2>:                     Address objects.    (line  195)
* RFC; RFC 4291 <3>:                     Address objects.    (line  235)
* RFC; RFC 4337:                         mimetypes.          (line   60)
* RFC; RFC 4380:                         Address objects.    (line  327)
* RFC; RFC 4627:                         json — JSON encoder and decoder.
                                                             (line   11)
* RFC; RFC 4627 <1>:                     Top-level Non-Object Non-Array Values.
                                                             (line    6)
* RFC; RFC 4648:                         Documentation<35>.  (line   32)
* RFC; RFC 4648 <1>:                     base64 — Base16 Base32 Base64 Base85 Data Encodings.
                                                             (line   12)
* RFC; RFC 4648 <2>:                     base64 — Base16 Base32 Base64 Base85 Data Encodings.
                                                             (line   18)
* RFC; RFC 4648 <3>:                     RFC 4648 Encodings. (line    6)
* RFC; RFC 4648 <4>:                     RFC 4648 Encodings. (line   87)
* RFC; RFC 4648 <5>:                     RFC 4648 Encodings. (line  102)
* RFC; RFC 4648 <6>:                     RFC 4648 Encodings. (line  109)
* RFC; RFC 4648 <7>:                     Security Considerations<2>.
                                                             (line    6)
* RFC; RFC 4648 <8>:                     Security Considerations<3>.
                                                             (line    8)
* RFC; RFC 4918:                         HTTP status codes.  (line   46)
* RFC; RFC 4918 <1>:                     HTTP status codes.  (line  142)
* RFC; RFC 4918 <2>:                     HTTP status codes.  (line  145)
* RFC; RFC 4918 <3>:                     HTTP status codes.  (line  187)
* RFC; RFC 4954:                         SMTP Objects.       (line  135)
* RFC; RFC 4954 <1>:                     SMTP Objects.       (line  158)
* RFC; RFC 5161:                         imaplib<3>.         (line   11)
* RFC; RFC 5161 <1>:                     IMAP4 Objects.      (line   86)
* RFC; RFC 5246:                         Constants<9>.       (line  521)
* RFC; RFC 5246 <1>:                     TLS 1 3.            (line   53)
* RFC; RFC 5280:                         ssl<2>.             (line   10)
* RFC; RFC 5280 <1>:                     Other Changes.      (line   20)
* RFC; RFC 5280 <2>:                     Changes in the Python API<9>.
                                                             (line   96)
* RFC; RFC 5280 <3>:                     Context creation.   (line   40)
* RFC; RFC 5280 <4>:                     Context creation.   (line   65)
* RFC; RFC 5280 <5>:                     Certificate handling.
                                                             (line   22)
* RFC; RFC 5280 <6>:                     TLS 1 3.            (line   49)
* RFC; RFC 5321:                         smtpd<4>.           (line    6)
* RFC; RFC 5321 <1>:                     email headerregistry Custom Header Objects.
                                                             (line  453)
* RFC; RFC 5322:                         Batterie Incluse.   (line   16)
* RFC; RFC 5322 <1>:                     Functions<4>.       (line  752)
* RFC; RFC 5322 <2>:                     Functions<4>.       (line  765)
* RFC; RFC 5322 <3>:                     Functions<4>.       (line  463)
* RFC; RFC 5322 <4>:                     Functions<4>.       (line  782)
* RFC; RFC 5322 <5>:                     email — An email and MIME handling package.
                                                             (line   14)
* RFC; RFC 5322 <6>:                     email message Representing an email message.
                                                             (line   20)
* RFC; RFC 5322 <7>:                     email message Representing an email message.
                                                             (line   31)
* RFC; RFC 5322 <8>:                     Parser API.         (line   42)
* RFC; RFC 5322 <9>:                     email generator Generating MIME documents.
                                                             (line  102)
* RFC; RFC 5322 <10>:                    email generator Generating MIME documents.
                                                             (line  196)
* RFC; RFC 5322 <11>:                    email policy Policy Objects.
                                                             (line  149)
* RFC; RFC 5322 <12>:                    email policy Policy Objects.
                                                             (line  343)
* RFC; RFC 5322 <13>:                    email policy Policy Objects.
                                                             (line  364)
* RFC; RFC 5322 <14>:                    email policy Policy Objects.
                                                             (line  370)
* RFC; RFC 5322 <15>:                    email policy Policy Objects.
                                                             (line  382)
* RFC; RFC 5322 <16>:                    email policy Policy Objects.
                                                             (line  415)
* RFC; RFC 5322 <17>:                    email errors Exception and Defect classes.
                                                             (line   28)
* RFC; RFC 5322 <18>:                    email headerregistry Custom Header Objects.
                                                             (line   16)
* RFC; RFC 5322 <19>:                    email headerregistry Custom Header Objects.
                                                             (line  117)
* RFC; RFC 5322 <20>:                    email headerregistry Custom Header Objects.
                                                             (line  122)
* RFC; RFC 5322 <21>:                    email headerregistry Custom Header Objects.
                                                             (line  123)
* RFC; RFC 5322 <22>:                    email headerregistry Custom Header Objects.
                                                             (line  138)
* RFC; RFC 5322 <23>:                    email headerregistry Custom Header Objects.
                                                             (line  159)
* RFC; RFC 5322 <24>:                    email headerregistry Custom Header Objects.
                                                             (line  416)
* RFC; RFC 5322 <25>:                    email headerregistry Custom Header Objects.
                                                             (line  450)
* RFC; RFC 5322 <26>:                    email headerregistry Custom Header Objects.
                                                             (line  484)
* RFC; RFC 5322 <27>:                    email message Message Representing an email message using the compat32 API.
                                                             (line   21)
* RFC; RFC 5322 <28>:                    Message objects.    (line   17)
* RFC; RFC 5322 <29>:                    http client — HTTP protocol client.
                                                             (line  115)
* RFC; RFC 5322 <30>:                    SMTP Objects.       (line  314)
* RFC; RFC 5322 <31>:                    http server — HTTP servers.
                                                             (line  163)
* RFC; RFC 5322 Section 2.2:             Library<27>.        (line  171)
* RFC; RFC 5334:                         mimetypes.          (line   62)
* RFC; RFC 5424:                         SysLogHandler.      (line   77)
* RFC; RFC 5424 <1>:                     Inserting a BOM into messages sent to a SysLogHandler.
                                                             (line    6)
* RFC; RFC 5424 <2>:                     Inserting a BOM into messages sent to a SysLogHandler.
                                                             (line   19)
* RFC; RFC 5424 <3>:                     Inserting a BOM into messages sent to a SysLogHandler.
                                                             (line   43)
* RFC; RFC 5424 <4>:                     Logging to syslog with RFC5424 support.
                                                             (line    6)
* RFC; RFC 5424 Section 6:               Inserting a BOM into messages sent to a SysLogHandler.
                                                             (line    9)
* RFC; RFC 5735:                         Address objects.    (line  164)
* RFC; RFC 5789:                         HTTP methods.       (line   37)
* RFC; RFC 5842:                         HTTP status codes.  (line   49)
* RFC; RFC 5842 <1>:                     HTTP status codes.  (line  190)
* RFC; RFC 5891:                         encodings idna — Internationalized Domain Names in Applications.
                                                             (line   11)
* RFC; RFC 5894:                         Security<26>.       (line   20)
* RFC; RFC 5895:                         encodings idna — Internationalized Domain Names in Applications.
                                                             (line   11)
* RFC; RFC 5929:                         SSL Sockets.        (line  271)
* RFC; RFC 6066:                         Constants<9>.       (line  409)
* RFC; RFC 6066 <1>:                     SSL Contexts.       (line  290)
* RFC; RFC 6066 <2>:                     TLS 1 3.            (line   57)
* RFC; RFC 6152:                         smtpd<2>.           (line   15)
* RFC; RFC 6531:                         email<4>.           (line   19)
* RFC; RFC 6531 <1>:                     smtpd<2>.           (line   21)
* RFC; RFC 6531 <2>:                     smtplib<2>.         (line   15)
* RFC; RFC 6531 <3>:                     email message Representing an email message.
                                                             (line  103)
* RFC; RFC 6531 <4>:                     email policy Policy Objects.
                                                             (line  386)
* RFC; RFC 6531 <5>:                     smtplib — SMTP protocol client.
                                                             (line   68)
* RFC; RFC 6532:                         email<4>.           (line   18)
* RFC; RFC 6532 <1>:                     email — An email and MIME handling package.
                                                             (line   14)
* RFC; RFC 6532 <2>:                     email message Representing an email message.
                                                             (line   20)
* RFC; RFC 6532 <3>:                     Parser API.         (line   43)
* RFC; RFC 6532 <4>:                     email policy Policy Objects.
                                                             (line  384)
* RFC; RFC 6585:                         HTTP status codes.  (line  154)
* RFC; RFC 6585 <1>:                     HTTP status codes.  (line  157)
* RFC; RFC 6585 <2>:                     HTTP status codes.  (line  160)
* RFC; RFC 6585 <3>:                     HTTP status codes.  (line  196)
* RFC; RFC 6713:                         mimetypes.          (line   64)
* RFC; RFC 6855:                         imaplib<3>.         (line   12)
* RFC; RFC 6855 <1>:                     imaplib<3>.         (line   14)
* RFC; RFC 6855 <2>:                     IMAP4 Objects.      (line   88)
* RFC; RFC 6855 <3>:                     IMAP4 Objects.      (line   90)
* RFC; RFC 6856:                         poplib<2>.          (line    6)
* RFC; RFC 6856 <1>:                     POP3 Objects.       (line  109)
* RFC; RFC 7159:                         json — JSON encoder and decoder.
                                                             (line   10)
* RFC; RFC 7159 <1>:                     Standard Compliance and Interoperability.
                                                             (line    6)
* RFC; RFC 7159 <2>:                     Top-level Non-Object Non-Array Values.
                                                             (line    9)
* RFC; RFC 7230:                         urllib request — Extensible library for opening URLs.
                                                             (line  246)
* RFC; RFC 7230 <1>:                     HTTPConnection Objects.
                                                             (line  198)
* RFC; RFC 7301:                         Application-Layer Protocol Negotiation Support.
                                                             (line   10)
* RFC; RFC 7301 <1>:                     Constants<9>.       (line  386)
* RFC; RFC 7301 <2>:                     SSL Contexts.       (line  258)
* RFC; RFC 7525:                         TLS 1 3.            (line   65)
* RFC; RFC 7538:                         Library<105>.       (line  171)
* RFC; RFC 7616:                         urllib.             (line    8)
* RFC; RFC 7616 <1>:                     Library<37>.        (line    8)
* RFC; RFC 7693:                         BLAKE2.             (line    6)
* RFC; RFC 7725:                         HTTP status codes.  (line  163)
* RFC; RFC 7903:                         mimetypes.          (line   51)
* RFC; RFC 7914:                         Key derivation.     (line   53)
* RFC; RFC 8081:                         mimetypes.          (line   15)
* RFC; RFC 8089:                         Parsing and generating URIs.
                                                             (line    7)
* RFC; RFC 8089 Section 3:               urllib request — Extensible library for opening URLs.
                                                             (line  183)
* RFC; RFC 821:                          smtplib — SMTP protocol client.
                                                             (line   12)
* RFC; RFC 821 <1>:                      smtplib — SMTP protocol client.
                                                             (line  197)
* RFC; RFC 822:                          New and Improved Modules<3>.
                                                             (line   98)
* RFC; RFC 822 <1>:                      Functions<4>.       (line  745)
* RFC; RFC 822 <2>:                      Functions<4>.       (line  748)
* RFC; RFC 822 <3>:                      Functions<4>.       (line  758)
* RFC; RFC 822 <4>:                      Functions<4>.       (line  761)
* RFC; RFC 822 <5>:                      Functions<4>.       (line  775)
* RFC; RFC 822 <6>:                      Functions<4>.       (line  778)
* RFC; RFC 822 <7>:                      email Examples.     (line   36)
* RFC; RFC 822 <8>:                      email header Internationalized headers.
                                                             (line   21)
* RFC; RFC 822 <9>:                      HTTPConnection Objects.
                                                             (line  185)
* RFC; RFC 822 <10>:                     SMTP Objects.       (line   94)
* RFC; RFC 822 <11>:                     SMTP Objects.       (line  229)
* RFC; RFC 822 <12>:                     SMTP Objects.       (line  230)
* RFC; RFC 822 <13>:                     SMTP Example.       (line   10)
* RFC; RFC 822 <14>:                     The GNUTranslations class.
                                                             (line   13)
* RFC; RFC 8297:                         HTTP status codes.  (line   22)
* RFC; RFC 8305:                         Opening network connections.
                                                             (line   77)
* RFC; RFC 8305 <1>:                     Opening network connections.
                                                             (line   86)
* RFC; RFC 8470:                         HTTP status codes.  (line  148)
* RFC; RFC 850:                          Library<39>.        (line  212)
* RFC; RFC 9110:                         Library<39>.        (line  212)
* RFC; RFC 9110 <1>:                     HTTP status codes.  (line   13)
* RFC; RFC 9110 <2>:                     HTTP status codes.  (line   16)
* RFC; RFC 9110 <3>:                     HTTP status codes.  (line   25)
* RFC; RFC 9110 <4>:                     HTTP status codes.  (line   28)
* RFC; RFC 9110 <5>:                     HTTP status codes.  (line   31)
* RFC; RFC 9110 <6>:                     HTTP status codes.  (line   34)
* RFC; RFC 9110 <7>:                     HTTP status codes.  (line   37)
* RFC; RFC 9110 <8>:                     HTTP status codes.  (line   40)
* RFC; RFC 9110 <9>:                     HTTP status codes.  (line   43)
* RFC; RFC 9110 <10>:                    HTTP status codes.  (line   55)
* RFC; RFC 9110 <11>:                    HTTP status codes.  (line   58)
* RFC; RFC 9110 <12>:                    HTTP status codes.  (line   61)
* RFC; RFC 9110 <13>:                    HTTP status codes.  (line   64)
* RFC; RFC 9110 <14>:                    HTTP status codes.  (line   67)
* RFC; RFC 9110 <15>:                    HTTP status codes.  (line   70)
* RFC; RFC 9110 <16>:                    HTTP status codes.  (line   73)
* RFC; RFC 9110 <17>:                    HTTP status codes.  (line   76)
* RFC; RFC 9110 <18>:                    HTTP status codes.  (line   79)
* RFC; RFC 9110 <19>:                    HTTP status codes.  (line   82)
* RFC; RFC 9110 <20>:                    HTTP status codes.  (line   85)
* RFC; RFC 9110 <21>:                    HTTP status codes.  (line   88)
* RFC; RFC 9110 <22>:                    HTTP status codes.  (line   91)
* RFC; RFC 9110 <23>:                    HTTP status codes.  (line   94)
* RFC; RFC 9110 <24>:                    HTTP status codes.  (line   97)
* RFC; RFC 9110 <25>:                    HTTP status codes.  (line  100)
* RFC; RFC 9110 <26>:                    HTTP status codes.  (line  103)
* RFC; RFC 9110 <27>:                    HTTP status codes.  (line  106)
* RFC; RFC 9110 <28>:                    HTTP status codes.  (line  109)
* RFC; RFC 9110 <29>:                    HTTP status codes.  (line  112)
* RFC; RFC 9110 <30>:                    HTTP status codes.  (line  115)
* RFC; RFC 9110 <31>:                    HTTP status codes.  (line  118)
* RFC; RFC 9110 <32>:                    HTTP status codes.  (line  121)
* RFC; RFC 9110 <33>:                    HTTP status codes.  (line  124)
* RFC; RFC 9110 <34>:                    HTTP status codes.  (line  127)
* RFC; RFC 9110 <35>:                    HTTP status codes.  (line  130)
* RFC; RFC 9110 <36>:                    HTTP status codes.  (line  136)
* RFC; RFC 9110 <37>:                    HTTP status codes.  (line  139)
* RFC; RFC 9110 <38>:                    HTTP status codes.  (line  151)
* RFC; RFC 9110 <39>:                    HTTP status codes.  (line  166)
* RFC; RFC 9110 <40>:                    HTTP status codes.  (line  169)
* RFC; RFC 9110 <41>:                    HTTP status codes.  (line  172)
* RFC; RFC 9110 <42>:                    HTTP status codes.  (line  175)
* RFC; RFC 9110 <43>:                    HTTP status codes.  (line  178)
* RFC; RFC 9110 <44>:                    HTTP status codes.  (line  181)
* RFC; RFC 9110 <45>:                    HTTP status category.
                                                             (line   15)
* RFC; RFC 9110 <46>:                    HTTP status category.
                                                             (line   18)
* RFC; RFC 9110 <47>:                    HTTP status category.
                                                             (line   21)
* RFC; RFC 9110 <48>:                    HTTP status category.
                                                             (line   24)
* RFC; RFC 9110 <49>:                    HTTP status category.
                                                             (line   27)
* RFC; RFC 9110 <50>:                    HTTP methods.       (line   13)
* RFC; RFC 9110 <51>:                    HTTP methods.       (line   16)
* RFC; RFC 9110 <52>:                    HTTP methods.       (line   19)
* RFC; RFC 9110 <53>:                    HTTP methods.       (line   22)
* RFC; RFC 9110 <54>:                    HTTP methods.       (line   25)
* RFC; RFC 9110 <55>:                    HTTP methods.       (line   28)
* RFC; RFC 9110 <56>:                    HTTP methods.       (line   31)
* RFC; RFC 9110 <57>:                    HTTP methods.       (line   34)
* RFC; RFC 9239:                         Library<86>.        (line   74)
* RFC; RFC 9512:                         mimetypes.          (line   68)
* RFC; RFC 9512 <1>:                     Library<23>.        (line  274)
* RFC; RFC 9559:                         mimetypes.          (line   27)
* RFC; RFC 9559 <1>:                     Library<41>.        (line  105)
* RFC; RFC 9562:                         uuid.               (line    8)
* RFC; RFC 9562 <1>:                     uuid.               (line   12)
* RFC; RFC 9562 <2>:                     Library<29>.        (line  256)
* RFC; RFC 9562 <3>:                     Library<29>.        (line  259)
* RFC; RFC 9562 <4>:                     Library<32>.        (line  174)
* RFC; RFC 9562 <5>:                     Library<41>.        (line  373)
* RFC; RFC 9562 <6>:                     uuid — UUID objects according to RFC 9562.
                                                             (line    6)
* RFC; RFC 9562 <7>:                     uuid — UUID objects according to RFC 9562.
                                                             (line   14)
* RFC; RFC 9562 <8>:                     uuid — UUID objects according to RFC 9562.
                                                             (line   76)
* RFC; RFC 9562 <9>:                     uuid — UUID objects according to RFC 9562.
                                                             (line  152)
* RFC; RFC 9562 <10>:                    uuid — UUID objects according to RFC 9562.
                                                             (line  305)
* RFC; RFC 9562 <11>:                    uuid — UUID objects according to RFC 9562.
                                                             (line  334)
* RFC; RFC 9562 Section 5.1:             uuid — UUID objects according to RFC 9562.
                                                             (line  199)
* RFC; RFC 9562 Section 5.10:            uuid — UUID objects according to RFC 9562.
                                                             (line  327)
* RFC; RFC 9562 Section 5.3:             uuid — UUID objects according to RFC 9562.
                                                             (line  213)
* RFC; RFC 9562 Section 5.4:             uuid — UUID objects according to RFC 9562.
                                                             (line  219)
* RFC; RFC 9562 Section 5.5:             uuid — UUID objects according to RFC 9562.
                                                             (line  225)
* RFC; RFC 9562 Section 5.6:             uuid — UUID objects according to RFC 9562.
                                                             (line  231)
* RFC; RFC 9562 Section 5.7:             uuid — UUID objects according to RFC 9562.
                                                             (line  248)
* RFC; RFC 9562 Section 5.8:             uuid — UUID objects according to RFC 9562.
                                                             (line  258)
* RFC; RFC 9562 Section 5.9:             uuid — UUID objects according to RFC 9562.
                                                             (line  320)
* RFC; RFC 9562 Section 6.10-3:          Library<18>.        (line   33)
* RFC; RFC 959:                          ftplib — FTP protocol client.
                                                             (line   16)
* RFC; RFC 9639:                         mimetypes.          (line   66)
* rfc2109 (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   72)
* rfc2109_as_netscape (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line   83)
* rfc2965 (http.cookiejar.CookiePolicy attributo): CookiePolicy Objects.
                                                             (line   72)
* rfile (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  165)
* rfile (socketserver.DatagramRequestHandler attributo): Request Handler Objects.
                                                             (line   63)
* rfind() (bytearray metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  222)
* rfind() (bytes metodo):                Operazioni su Bytes e Bytearray.
                                                             (line  222)
* rfind() (mmap.mmap metodo):            mmap — Memory-mapped file support.
                                                             (line  286)
* rfind() (str metodo):                  Metodi per le Stringhe.
                                                             (line  578)
* rgb_to_hls() (nel modulo colorsys):    colorsys — Conversions between color systems.
                                                             (line   36)
* rgb_to_hsv() (nel modulo colorsys):    colorsys — Conversions between color systems.
                                                             (line   44)
* rgb_to_yiq() (nel modulo colorsys):    colorsys — Conversions between color systems.
                                                             (line   28)
* rglob() (pathlib.Path metodo):         Reading directories.
                                                             (line   83)
* richcmpfunc (C type):                  Slot Type typedefs. (line   81)
* right (filecmp.dircmp attributo):      The dircmp class.   (line   49)
* right_list (filecmp.dircmp attributo): The dircmp class.   (line   58)
* right_only (filecmp.dircmp attributo): The dircmp class.   (line   71)
* right() (nel modulo turtle):           Turtle motion.      (line   40)
* RIGHTSHIFT (nel modulo token):         token — Constants used with Python parse trees.
                                                             (line  293)
* RIGHTSHIFTEQUAL (nel modulo token):    token — Constants used with Python parse trees.
                                                             (line  326)
* rindex() (bytearray metodo):           Operazioni su Bytes e Bytearray.
                                                             (line  237)
* rindex() (bytes metodo):               Operazioni su Bytes e Bytearray.
                                                             (line  237)
* rindex() (str metodo):                 Metodi per le Stringhe.
                                                             (line  592)
* ripetizione;operazione:                Operazioni Comuni sulle Sequenze.
                                                             (line   22)
* rjust() (bytearray metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  356)
* rjust() (bytes metodo):                Operazioni su Bytes e Bytearray.
                                                             (line  356)
* rjust() (str metodo):                  Metodi per le Stringhe.
                                                             (line  597)
* RLIM_INFINITY (nel modulo resource):   Resource Limits.    (line   20)
* RLIMIT_AS (nel modulo resource):       Resource Limits.    (line  149)
* RLIMIT_CORE (nel modulo resource):     Resource Limits.    (line   91)
* RLIMIT_CPU (nel modulo resource):      Resource Limits.    (line   98)
* RLIMIT_DATA (nel modulo resource):     Resource Limits.    (line  110)
* RLIMIT_FSIZE (nel modulo resource):    Resource Limits.    (line  106)
* RLIMIT_KQUEUES (nel modulo resource):  Resource Limits.    (line  225)
* RLIMIT_MEMLOCK (nel modulo resource):  Resource Limits.    (line  138)
* RLIMIT_MSGQUEUE (nel modulo resource): Resource Limits.    (line  154)
* RLIMIT_NICE (nel modulo resource):     Resource Limits.    (line  162)
* RLIMIT_NOFILE (nel modulo resource):   Resource Limits.    (line  129)
* RLIMIT_NPROC (nel modulo resource):    Resource Limits.    (line  125)
* RLIMIT_NPTS (nel modulo resource):     Resource Limits.    (line  217)
* RLIMIT_OFILE (nel modulo resource):    Resource Limits.    (line  134)
* RLIMIT_RSS (nel modulo resource):      Resource Limits.    (line  120)
* RLIMIT_RTPRIO (nel modulo resource):   Resource Limits.    (line  171)
* RLIMIT_RTTIME (nel modulo resource):   Resource Limits.    (line  179)
* RLIMIT_SBSIZE (nel modulo resource):   Resource Limits.    (line  196)
* RLIMIT_SIGPENDING (nel modulo resource): Resource Limits.  (line  188)
* RLIMIT_STACK (nel modulo resource):    Resource Limits.    (line  114)
* RLIMIT_SWAP (nel modulo resource):     Resource Limits.    (line  206)
* RLIMIT_VMEM (nel modulo resource):     Resource Limits.    (line  142)
* RLock (classe in multiprocessing):     Synchronization primitives.
                                                             (line  131)
* RLock (classe in threading):           RLock objects.      (line   32)
* RLock() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  205)
* rmd() (ftplib.FTP metodo):             FTP objects.        (line  349)
* rmdir() (nel modulo os):               Files and Directories.
                                                             (line  829)
* rmdir() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line  114)
* rmdir() (pathlib.Path metodo):         Copying moving and deleting.
                                                             (line  121)
* rmtree() (nel modulo shutil):          Directory and files operations.
                                                             (line  283)
* rmtree() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line  121)
* RobotFileParser (classe in urllib.robotparser): urllib robotparser — Parser for robots txt.
                                                             (line   16)
* robots.txt:                            urllib robotparser — Parser for robots txt.
                                                             (line    8)
* rollback() (sqlite3.Connection metodo): Connection objects.
                                                             (line   80)
* rollover() (tempfile.SpooledTemporaryFile metodo): tempfile — Generate temporary files and directories.
                                                             (line  162)
* ROMAN (nel modulo tkinter.font):       tkinter font — Tkinter font wrapper.
                                                             (line   15)
* root (pathlib.PurePath attributo):     Methods and properties.
                                                             (line   31)
* rotate() (collections.deque metodo):   deque objects.      (line  109)
* rotate() (decimal.Context metodo):     Context objects.    (line  521)
* rotate() (decimal.Decimal metodo):     Decimal objects.    (line  547)
* rotate() (logging.handlers.BaseRotatingHandler metodo): BaseRotatingHandler.
                                                             (line   74)
* RotatingFileHandler (classe in logging.handlers): RotatingFileHandler.
                                                             (line    9)
* rotation_filename() (logging.handlers.BaseRotatingHandler metodo): BaseRotatingHandler.
                                                             (line   58)
* rotator (logging.handlers.BaseRotatingHandler attributo): BaseRotatingHandler.
                                                             (line   49)
* ROUND_05UP (nel modulo decimal):       Rounding modes.     (line   34)
* ROUND_CEILING (nel modulo decimal):    Rounding modes.     (line    6)
* ROUND_DOWN (nel modulo decimal):       Rounding modes.     (line   10)
* ROUND_FLOOR (nel modulo decimal):      Rounding modes.     (line   14)
* ROUND_HALF_DOWN (nel modulo decimal):  Rounding modes.     (line   18)
* ROUND_HALF_EVEN (nel modulo decimal):  Rounding modes.     (line   22)
* ROUND_HALF_UP (nel modulo decimal):    Rounding modes.     (line   26)
* ROUND_UP (nel modulo decimal):         Rounding modes.     (line   30)
* Rounded (classe in decimal):           Signals.            (line   79)
* rounding (decimal.Context attributo):  Context objects.    (line  137)
* rounds (sys.float_info attributo):     sys — System-specific parameters and functions.
                                                             (line  704)
* Row (classe in sqlite3):               Row objects.        (line    6)
* row_factory (sqlite3.Connection attributo): Connection objects.
                                                             (line  796)
* row_factory (sqlite3.Cursor attributo): Cursor objects.    (line  233)
* rowcount (sqlite3.Cursor attributo):   Cursor objects.     (line  222)
* RPAR (nel modulo token):               token — Constants used with Python parse trees.
                                                             (line  215)
* rpartition() (bytearray metodo):       Operazioni su Bytes e Bytearray.
                                                             (line  249)
* rpartition() (bytes metodo):           Operazioni su Bytes e Bytearray.
                                                             (line  249)
* rpartition() (str metodo):             Metodi per le Stringhe.
                                                             (line  605)
* rpc_paths (xmlrpc.server.SimpleXMLRPCRequestHandler attributo): SimpleXMLRPCServer Objects.
                                                             (line   64)
* rpop() (poplib.POP3 metodo):           POP3 Objects.       (line   47)
* RS (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line  115)
* rset() (poplib.POP3 metodo):           POP3 Objects.       (line   75)
* RShift (classe in ast):                Expressions<2>.     (line   53)
* rshift() (nel modulo operator):        operator — Standard operators as functions.
                                                             (line  164)
* rsplit() (bytearray metodo):           Operazioni su Bytes e Bytearray.
                                                             (line  369)
* rsplit() (bytes metodo):               Operazioni su Bytes e Bytearray.
                                                             (line  369)
* rsplit() (str metodo):                 Metodi per le Stringhe.
                                                             (line  624)
* RSQB (nel modulo token):               token — Constants used with Python parse trees.
                                                             (line  221)
* rstrip() (bytearray metodo):           Operazioni su Bytes e Bytearray.
                                                             (line  381)
* rstrip() (bytes metodo):               Operazioni su Bytes e Bytearray.
                                                             (line  381)
* rstrip() (str metodo):                 Metodi per le Stringhe.
                                                             (line  634)
* rt() (nel modulo turtle):              Turtle motion.      (line   40)
* RTLD_DEEPBIND (nel modulo os):         Miscellaneous System Information.
                                                             (line  164)
* RTLD_GLOBAL (nel modulo os):           Miscellaneous System Information.
                                                             (line  164)
* RTLD_LAZY (nel modulo os):             Miscellaneous System Information.
                                                             (line  164)
* RTLD_LOCAL (nel modulo os):            Miscellaneous System Information.
                                                             (line  164)
* RTLD_NODELETE (nel modulo os):         Miscellaneous System Information.
                                                             (line  164)
* RTLD_NOLOAD (nel modulo os):           Miscellaneous System Information.
                                                             (line  164)
* RTLD_NOW (nel modulo os):              Miscellaneous System Information.
                                                             (line  164)
* ruler (cmd.Cmd attributo):             Cmd Objects.        (line  172)
* run (pdb command):                     Debugger commands.  (line  428)
* Run script:                            Format menu Editor window only.
                                                             (line   53)
* run_concurrently() (nel modulo test.support.threading_helper): test support threading_helper — Utilities for threading tests.
                                                             (line   82)
* run_coroutine_threadsafe() (nel modulo asyncio): Scheduling From Other Threads.
                                                             (line    6)
* run_docstring_examples() (nel modulo doctest): Basic API.  (line  127)
* run_forever() (asyncio.loop metodo):   Running and stopping the loop.
                                                             (line   16)
* run_in_executor() (asyncio.loop metodo): Executing code in thread or process pools.
                                                             (line    6)
* run_in_subinterp() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  695)
* run_module() (nel modulo runpy):       runpy — Locating and executing Python modules.
                                                             (line   27)
* run_path() (nel modulo runpy):         runpy — Locating and executing Python modules.
                                                             (line   98)
* run_python_until_end() (nel modulo test.support.script_helper): test support script_helper — Utilities for the Python execution tests.
                                                             (line   30)
* run_script() (modulefinder.ModuleFinder metodo): modulefinder — Find modules used by a script.
                                                             (line   44)
* run_until_complete() (asyncio.loop metodo): Running and stopping the loop.
                                                             (line    6)
* run_with_locale() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  484)
* run_with_tz() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  492)
* run() (asyncio.Runner metodo):         Runner context manager.
                                                             (line   36)
* run() (bdb.Bdb metodo):                bdb — Debugger framework.
                                                             (line  480)
* run() (contextvars.Context metodo):    Manual Context Management.
                                                             (line   64)
* run() (doctest.DocTestRunner metodo):  DocTestRunner objects.
                                                             (line  101)
* run() (multiprocessing.Process metodo): Process and exceptions.
                                                             (line   68)
* run() (nel modulo asyncio):            Running an asyncio Program.
                                                             (line    6)
* run() (nel modulo pdb):                Command-line interface<8>.
                                                             (line   83)
* run() (nel modulo profile):            profile and cProfile Module Reference.
                                                             (line    9)
* run() (nel modulo subprocess):         Using the subprocess Module.
                                                             (line   11)
* run() (pdb.Pdb metodo):                Command-line interface<8>.
                                                             (line  240)
* run() (profile.Profile metodo):        profile and cProfile Module Reference.
                                                             (line  108)
* run() (sched.scheduler metodo):        Scheduler Objects.  (line   51)
* run() (threading.Thread metodo):       Thread objects.     (line  124)
* run() (trace.Trace metodo):            Programmatic Interface.
                                                             (line   22)
* run() (unittest.IsolatedAsyncioTestCase metodo): Test cases.
                                                             (line  970)
* run() (unittest.TestCase metodo):      Test cases.         (line   83)
* run() (unittest.TestSuite metodo):     Grouping tests.     (line   41)
* run() (unittest.TextTestRunner metodo): Loading and running tests.
                                                             (line  509)
* run() (wsgiref.handlers.BaseHandler metodo): wsgiref handlers – server/gateway base classes.
                                                             (line   99)
* runcall() (bdb.Bdb metodo):            bdb — Debugger framework.
                                                             (line  497)
* runcall() (nel modulo pdb):            Command-line interface<8>.
                                                             (line  102)
* runcall() (pdb.Pdb metodo):            Command-line interface<8>.
                                                             (line  240)
* runcall() (profile.Profile metodo):    profile and cProfile Module Reference.
                                                             (line  117)
* runcode() (code.InteractiveInterpreter metodo): Interactive Interpreter Objects.
                                                             (line   33)
* runctx() (bdb.Bdb metodo):             bdb — Debugger framework.
                                                             (line  492)
* runctx() (nel modulo profile):         profile and cProfile Module Reference.
                                                             (line   23)
* runctx() (profile.Profile metodo):     profile and cProfile Module Reference.
                                                             (line  112)
* runctx() (trace.Trace metodo):         Programmatic Interface.
                                                             (line   28)
* runeval() (bdb.Bdb metodo):            bdb — Debugger framework.
                                                             (line  486)
* runeval() (nel modulo pdb):            Command-line interface<8>.
                                                             (line   95)
* runeval() (pdb.Pdb metodo):            Command-line interface<8>.
                                                             (line  240)
* runfunc() (trace.Trace metodo):        Programmatic Interface.
                                                             (line   35)
* Runner (classe in asyncio):            Runner context manager.
                                                             (line    6)
* running() (concurrent.futures.Future metodo): Future Objects.
                                                             (line   27)
* runsource() (code.InteractiveInterpreter metodo): Interactive Interpreter Objects.
                                                             (line    6)
* runtime (sys._emscripten_info attributo): sys — System-specific parameters and functions.
                                                             (line  354)
* runtime_checkable() (nel modulo typing): Other special directives.
                                                             (line  188)
* RuntimeError:                          Concrete exceptions.
                                                             (line  266)
* RuntimeWarning:                        Warnings.           (line   51)
* RUSAGE_BOTH (nel modulo resource):     Resource Usage.     (line  122)
* RUSAGE_CHILDREN (nel modulo resource): Resource Usage.     (line  116)
* RUSAGE_SELF (nel modulo resource):     Resource Usage.     (line  110)
* RUSAGE_THREAD (nel modulo resource):   Resource Usage.     (line  128)
* RWF_APPEND (nel modulo os):            File Descriptor Operations.
                                                             (line  719)
* RWF_DSYNC (nel modulo os):             File Descriptor Operations.
                                                             (line  699)
* RWF_HIPRI (nel modulo os):             File Descriptor Operations.
                                                             (line  629)
* RWF_NOWAIT (nel modulo os):            File Descriptor Operations.
                                                             (line  614)
* RWF_SYNC (nel modulo os):              File Descriptor Operations.
                                                             (line  709)
* S (nel modulo re):                     Flags.              (line  108)
* S_ENFMT (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  318)
* S_IEXEC (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  332)
* S_IFBLK (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  207)
* S_IFCHR (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  215)
* S_IFDIR (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  211)
* S_IFDOOR (nel modulo stat):            stat — Interpreting stat results.
                                                             (line  223)
* S_IFIFO (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  219)
* S_IFLNK (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  199)
* S_IFMT() (nel modulo stat):            stat — Interpreting stat results.
                                                             (line   79)
* S_IFPORT (nel modulo stat):            stat — Interpreting stat results.
                                                             (line  229)
* S_IFREG (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  203)
* S_IFSOCK (nel modulo stat):            stat — Interpreting stat results.
                                                             (line  195)
* S_IFWHT (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  235)
* S_IMODE() (nel modulo stat):           stat — Interpreting stat results.
                                                             (line   72)
* S_IREAD (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  324)
* S_IRGRP (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  290)
* S_IROTH (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  306)
* S_IRUSR (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  274)
* S_IRWXG (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  286)
* S_IRWXO (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  302)
* S_IRWXU (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  270)
* S_ISBLK() (nel modulo stat):           stat — Interpreting stat results.
                                                             (line   31)
* S_ISCHR() (nel modulo stat):           stat — Interpreting stat results.
                                                             (line   26)
* S_ISDIR() (nel modulo stat):           stat — Interpreting stat results.
                                                             (line   22)
* S_ISDOOR() (nel modulo stat):          stat — Interpreting stat results.
                                                             (line   51)
* S_ISFIFO() (nel modulo stat):          stat — Interpreting stat results.
                                                             (line   39)
* S_ISGID (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  252)
* S_ISLNK() (nel modulo stat):           stat — Interpreting stat results.
                                                             (line   43)
* S_ISPORT() (nel modulo stat):          stat — Interpreting stat results.
                                                             (line   57)
* S_ISREG() (nel modulo stat):           stat — Interpreting stat results.
                                                             (line   35)
* S_ISSOCK() (nel modulo stat):          stat — Interpreting stat results.
                                                             (line   47)
* S_ISUID (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  248)
* S_ISVTX (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  263)
* S_ISWHT() (nel modulo stat):           stat — Interpreting stat results.
                                                             (line   63)
* S_IWGRP (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  294)
* S_IWOTH (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  310)
* S_IWRITE (nel modulo stat):            stat — Interpreting stat results.
                                                             (line  328)
* S_IWUSR (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  278)
* S_IXGRP (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  298)
* S_IXOTH (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  314)
* S_IXUSR (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  282)
* safe (uuid.SafeUUID attributo):        uuid — UUID objects according to RFC 9562.
                                                             (line   36)
* safe_path (sys.flags attributo):       sys — System-specific parameters and functions.
                                                             (line  584)
* safe_substitute() (string.Template metodo): Template strings $-strings.
                                                             (line   60)
* saferepr() (nel modulo pprint):        Functions<3>.       (line  101)
* SafeUUID (classe in uuid):             uuid — UUID objects according to RFC 9562.
                                                             (line   32)
* same_files (filecmp.dircmp attributo): The dircmp class.   (line   89)
* same_quantum() (decimal.Context metodo): Context objects.  (line  525)
* same_quantum() (decimal.Decimal metodo): Decimal objects.  (line  559)
* samefile() (nel modulo os.path):       os path — Common pathname manipulations.
                                                             (line  446)
* samefile() (pathlib.Path metodo):      Querying file type and status.
                                                             (line  151)
* SameFileError:                         Directory and files operations.
                                                             (line   68)
* sameopenfile() (nel modulo os.path):   os path — Common pathname manipulations.
                                                             (line  460)
* samesite (http.cookies.Morsel attributo): Morsel Objects.  (line   13)
* samestat() (nel modulo os.path):       os path — Common pathname manipulations.
                                                             (line  469)
* sample() (nel modulo random):          Functions for sequences.
                                                             (line   71)
* samples() (statistics.NormalDist metodo): NormalDist objects.
                                                             (line   58)
* SATURDAY (nel modulo calendar):        calendar — General calendar-related functions.
                                                             (line  447)
* save() (http.cookiejar.FileCookieJar metodo): CookieJar and FileCookieJar Objects.
                                                             (line  106)
* save() (nel modulo turtle):            Methods specific to Screen not inherited from TurtleScreen.
                                                             (line   20)
* save() (test.support.SaveSignals metodo): test support — Utilities for the Python test suite.
                                                             (line  806)
* SaveAs (classe in tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line   60)
* SAVEDCWD (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   15)
* SaveFileDialog (classe in tkinter.filedialog): Native Load/Save Dialogs.
                                                             (line  145)
* SaveKey() (nel modulo winreg):         Functions<13>.      (line  395)
* SaveSignals (classe in test.support):  test support — Utilities for the Python test suite.
                                                             (line  801)
* savetty() (nel modulo curses):         Functions<5>.       (line  459)
* SAX2DOM (classe in xml.dom.pulldom):   xml dom pulldom — Support for building partial DOM trees.
                                                             (line   81)
* SAXException:                          xml sax — Support for SAX2 parsers.
                                                             (line   86)
* SAXNotRecognizedException:             xml sax — Support for SAX2 parsers.
                                                             (line  111)
* SAXNotSupportedException:              xml sax — Support for SAX2 parsers.
                                                             (line  118)
* SAXParseException:                     xml sax — Support for SAX2 parsers.
                                                             (line  103)
* scaleb() (decimal.Context metodo):     Context objects.    (line  529)
* scaleb() (decimal.Decimal metodo):     Decimal objects.    (line  569)
* scandir() (nel modulo os):             Files and Directories.
                                                             (line  846)
* scanf (C function):                    Simulating scanf.   (line    6)
* SCHED_BATCH (nel modulo os):           Interface to the scheduler.
                                                             (line   19)
* SCHED_DEADLINE (nel modulo os):        Interface to the scheduler.
                                                             (line   24)
* SCHED_FIFO (nel modulo os):            Interface to the scheduler.
                                                             (line   44)
* sched_get_priority_max() (nel modulo os): Interface to the scheduler.
                                                             (line   75)
* sched_get_priority_min() (nel modulo os): Interface to the scheduler.
                                                             (line   70)
* sched_getaffinity() (nel modulo os):   Interface to the scheduler.
                                                             (line  122)
* sched_getparam() (nel modulo os):      Interface to the scheduler.
                                                             (line   99)
* sched_getscheduler() (nel modulo os):  Interface to the scheduler.
                                                             (line   87)
* SCHED_IDLE (nel modulo os):            Interface to the scheduler.
                                                             (line   30)
* SCHED_NORMAL (nel modulo os):          Interface to the scheduler.
                                                             (line   34)
* SCHED_OTHER (nel modulo os):           Interface to the scheduler.
                                                             (line   15)
* sched_param (classe in os):            Interface to the scheduler.
                                                             (line   58)
* sched_priority (os.sched_param attributo): Interface to the scheduler.
                                                             (line   66)
* SCHED_RESET_ON_FORK (nel modulo os):   Interface to the scheduler.
                                                             (line   52)
* SCHED_RR (nel modulo os):              Interface to the scheduler.
                                                             (line   48)
* sched_rr_get_interval() (nel modulo os): Interface to the scheduler.
                                                             (line  105)
* sched_setaffinity() (nel modulo os):   Interface to the scheduler.
                                                             (line  115)
* sched_setparam() (nel modulo os):      Interface to the scheduler.
                                                             (line   93)
* sched_setscheduler() (nel modulo os):  Interface to the scheduler.
                                                             (line   80)
* SCHED_SPORADIC (nel modulo os):        Interface to the scheduler.
                                                             (line   40)
* sched_yield() (nel modulo os):         Interface to the scheduler.
                                                             (line  110)
* scheduler (classe in sched):           sched — Event scheduler.
                                                             (line   13)
* SCM_CREDS2 (nel modulo socket):        Constants<8>.       (line  413)
* scope:                                 Naming and binding. (line    6)
* scope <1>:                             Resolution of names.
                                                             (line    6)
* scope_id (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  310)
* Screen (classe in turtle):             Public classes.     (line   30)
* screensize() (nel modulo turtle):      Window control.     (line   90)
* script_from_examples() (nel modulo doctest): Debugging.    (line   72)
* scroll() (curses.window metodo):       Window Objects.     (line  509)
* ScrolledCanvas (classe in turtle):     Public classes.     (line   34)
* ScrolledText (classe in tkinter.scrolledtext): tkinter scrolledtext — Scrolled Text Widget.
                                                             (line   24)
* scrollok() (curses.window metodo):     Window Objects.     (line  513)
* scrypt() (nel modulo hashlib):         Key derivation.     (line   49)
* seal() (nel modulo unittest.mock):     Sealing mocks.      (line    6)
* search_function() (nel modulo encodings): encodings — Encodings package.
                                                             (line   23)
* search_log (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line   84)
* search() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line  305)
* search() (nel modulo re):              Functions.          (line   36)
* search() (re.Pattern metodo):          Regular Expression Objects.
                                                             (line   15)
* second (datetime.datetime attributo):  datetime Objects.   (line  326)
* second (datetime.time attributo):      time Objects.       (line   58)
* seconds (datetime.timedelta attributo): timedelta Objects. (line  114)
* seconds since the epoch:               time — Time access and conversions.
                                                             (line   24)
* SECTCRE (configparser.ConfigParser attributo): Customizing Parser Behaviour.
                                                             (line  301)
* sections() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  117)
* secure (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   49)
* secure (http.cookies.Morsel attributo): Morsel Objects.    (line   13)
* secure hash algorithm, SHA1, SHA2, SHA224, SHA256, SHA384, SHA512, SHA3, Shake, Blake2: hashlib — Secure hashes and message digests.
                                                             (line    8)
* Secure Sockets Layer:                  ssl — TLS/SSL wrapper for socket objects.
                                                             (line    8)
* security considerations:               xdrlib — Encode and decode XDR data.
                                                             (line   15)
* security_level (ssl.SSLContext attributo): SSL Contexts.   (line  626)
* see() (tkinter.ttk.Treeview metodo):   ttk Treeview.       (line  241)
* seed_bits (sys.hash_info attributo):   sys — System-specific parameters and functions.
                                                             (line 1100)
* seed() (nel modulo random):            Bookkeeping functions.
                                                             (line    6)
* seed() (random.Random metodo):         Alternative Generator.
                                                             (line   19)
* SEEK_CUR (nel modulo os):              File Descriptor Operations.
                                                             (line  327)
* SEEK_DATA (nel modulo os):             File Descriptor Operations.
                                                             (line  351)
* SEEK_END (nel modulo os):              File Descriptor Operations.
                                                             (line  327)
* SEEK_HOLE (nel modulo os):             File Descriptor Operations.
                                                             (line  351)
* SEEK_SET (nel modulo os):              File Descriptor Operations.
                                                             (line  327)
* seek() (io.IOBase metodo):             I/O Base Classes.   (line  106)
* seek() (io.TextIOBase metodo):         Text I/O<2>.        (line   66)
* seek() (io.TextIOWrapper metodo):      Text I/O<2>.        (line  209)
* seek() (mmap.mmap metodo):             mmap — Memory-mapped file support.
                                                             (line  296)
* seek() (sqlite3.Blob metodo):          Blob objects.       (line   63)
* seekable() (bz2.BZ2File metodo):       De compression of files.
                                                             (line  100)
* seekable() (io.IOBase metodo):         I/O Base Classes.   (line  129)
* seekable() (mmap.mmap metodo):         mmap — Memory-mapped file support.
                                                             (line  307)
* select() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line  322)
* select() (nel modulo select):          select — Waiting for I/O completion.
                                                             (line  117)
* select() (selectors.BaseSelector metodo): Classes<3>.      (line  108)
* select() (tkinter.ttk.Notebook metodo): ttk Notebook.      (line   53)
* selected_alpn_protocol() (ssl.SSLSocket metodo): SSL Sockets.
                                                             (line  277)
* selected_npn_protocol() (ssl.SSLSocket metodo): SSL Sockets.
                                                             (line  287)
* selection_add() (tkinter.ttk.Treeview metodo): ttk Treeview.
                                                             (line  264)
* selection_remove() (tkinter.ttk.Treeview metodo): ttk Treeview.
                                                             (line  271)
* selection_set() (tkinter.ttk.Treeview metodo): ttk Treeview.
                                                             (line  257)
* selection_toggle() (tkinter.ttk.Treeview metodo): ttk Treeview.
                                                             (line  278)
* selection() (tkinter.ttk.Treeview metodo): ttk Treeview.   (line  249)
* selector (urllib.request.Request attributo): Request Objects.
                                                             (line   34)
* SelectorEventLoop (classe in asyncio): Event Loop Implementations.
                                                             (line   11)
* SelectorKey (classe in selectors):     Classes<3>.         (line   29)
* SelectSelector (classe in selectors):  Classes<3>.         (line  167)
* Self (nel modulo typing):              Special types.      (line  138)
* Semaphore (classe in asyncio):         Semaphore.          (line    6)
* Semaphore (classe in multiprocessing): Synchronization primitives.
                                                             (line  206)
* Semaphore (classe in threading):       Semaphore objects.  (line   19)
* Semaphore() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  210)
* semaphores, binary:                    _thread — Low-level threading API.
                                                             (line    6)
* SEMI (nel modulo token):               token — Constants used with Python parse trees.
                                                             (line  230)
* SEND (opcode):                         Python Bytecode Instructions.
                                                             (line 1310)
* send_bytes() (multiprocessing.connection.Connection metodo): Connection Objects.
                                                             (line   54)
* send_error() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  263)
* send_fds() (nel modulo socket):        Other functions<2>. (line  462)
* send_header() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  299)
* send_message() (smtplib.SMTP metodo):  SMTP Objects.       (line  304)
* send_response_only() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  312)
* send_response() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  283)
* send_signal() (asyncio.subprocess.Process metodo): Interacting with Subprocesses.
                                                             (line   86)
* send_signal() (asyncio.SubprocessTransport metodo): Subprocess Transports.
                                                             (line   44)
* send_signal() (subprocess.Popen metodo): Popen Objects.    (line   83)
* send() (coroutine metodo):             Coroutine Objects.  (line   23)
* send() (generator metodo):             Generator-iterator methods.
                                                             (line   27)
* send() (http.client.HTTPConnection metodo): HTTPConnection Objects.
                                                             (line  217)
* send() (imaplib.IMAP4 metodo):         IMAP4 Objects.      (line  329)
* send() (logging.handlers.DatagramHandler metodo): DatagramHandler.
                                                             (line   43)
* send() (logging.handlers.SocketHandler metodo): SocketHandler.
                                                             (line   63)
* send() (multiprocessing.connection.Connection metodo): Connection Objects.
                                                             (line   15)
* send() (socket.socket metodo):         Socket Objects.     (line  399)
* sendall() (socket.socket metodo):      Socket Objects.     (line  416)
* sendcmd() (ftplib.FTP metodo):         FTP objects.        (line  158)
* sendfile() (asyncio.loop metodo):      Transferring files. (line    6)
* sendfile() (nel modulo os):            File Descriptor Operations.
                                                             (line  781)
* sendfile() (socket.socket metodo):     Socket Objects.     (line  512)
* sendfile() (wsgiref.handlers.BaseHandler metodo): wsgiref handlers – server/gateway base classes.
                                                             (line  282)
* SendfileNotAvailableError:             Exceptions<15>.     (line   37)
* sendfunc (C type):                     Slot Type typedefs. (line  114)
* sendmail() (smtplib.SMTP metodo):      SMTP Objects.       (line  226)
* sendmsg_afalg() (socket.socket metodo): Socket Objects.    (line  501)
* sendmsg() (socket.socket metodo):      Socket Objects.     (line  456)
* sendto() (asyncio.DatagramTransport metodo): Datagram Transports.
                                                             (line    6)
* sendto() (socket.socket metodo):       Socket Objects.     (line  436)
* sentinel (multiprocessing.Process attributo): Process and exceptions.
                                                             (line  189)
* sentinel (nel modulo unittest.mock):   sentinel.           (line    6)
* sep (nel modulo os):                   Miscellaneous System Information.
                                                             (line  116)
* SEPTEMBER (nel modulo calendar):       calendar — General calendar-related functions.
                                                             (line  490)
* sequence:                              Glossary.           (line 1562)
* Sequence (classe in collections.abc):  Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   68)
* Sequence (classe in typing):           Aliases to container ABCs in collections abc.
                                                             (line  112)
* sequence;item:                         Subscriptions.      (line    6)
* SequenceMatcher (classe in difflib):   SequenceMatcher Objects.
                                                             (line    8)
* sequenza mutabile;ciclo su:            Operazioni Comuni sulle Sequenze.
                                                             (line   69)
* sequenza;iterazione:                   Tipi di Iteratore.  (line    6)
* serialize() (sqlite3.Connection metodo): Connection objects.
                                                             (line  678)
* serializing;objects:                   pickle — Python object serialization.
                                                             (line    8)
* serve_forever() (asyncio.Server metodo): Server Objects.   (line   91)
* serve_forever() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line   33)
* Server (classe in asyncio):            Server Objects.     (line   12)
* server (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  123)
* server (socketserver.BaseRequestHandler attributo): Request Handler Objects.
                                                             (line   52)
* server_activate() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line  168)
* server_address (socketserver.BaseServer attributo): Server Objects<2>.
                                                             (line   80)
* server_bind() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line  174)
* server_close() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line   62)
* server_hostname (ssl.SSLSocket attributo): SSL Sockets.    (line  357)
* server_side (ssl.SSLSocket attributo): SSL Sockets.        (line  350)
* server_software (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  179)
* server_version (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  182)
* server_version (http.server.SimpleHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  407)
* ServerProxy (classe in xmlrpc.client): xmlrpc client — XML-RPC client access.
                                                             (line   30)
* service_actions() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line   46)
* session (ssl.SSLSocket attributo):     SSL Sockets.        (line  371)
* session_reused (ssl.SSLSocket attributo): SSL Sockets.     (line  381)
* session_stats() (ssl.SSLContext metodo): SSL Contexts.     (line  481)
* set (classe built-in):                 Tipi di Insiemi — set frozenset.
                                                             (line   34)
* Set (classe in ast):                   Literals<3>.        (line  154)
* Set (classe in collections.abc):       Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  115)
* Set (classe in typing):                Aliases to built-in types.
                                                             (line   30)
* Set Breakpoint:                        Help menu Shell and Editor.
                                                             (line   30)
* set comprehension:                     Glossary.           (line 1583)
* SET_ADD (opcode):                      Python Bytecode Instructions.
                                                             (line  372)
* set_all():                             Reference Count Details.
                                                             (line   98)
* set_allowed_domains() (http.cookiejar.DefaultCookiePolicy metodo): DefaultCookiePolicy Objects.
                                                             (line   70)
* set_alpn_protocols() (ssl.SSLContext metodo): SSL Contexts.
                                                             (line  252)
* set_app() (wsgiref.simple_server.WSGIServer metodo): wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line   64)
* set_asyncgen_hooks() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line 1843)
* set_authorizer() (sqlite3.Connection metodo): Connection objects.
                                                             (line  346)
* set_auto_history() (nel modulo readline): History list.    (line   43)
* set_blocked_domains() (http.cookiejar.DefaultCookiePolicy metodo): DefaultCookiePolicy Objects.
                                                             (line   56)
* set_blocking() (nel modulo os):        File Descriptor Operations.
                                                             (line  842)
* set_boundary() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  411)
* set_boundary() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  591)
* set_break() (bdb.Bdb metodo):          bdb — Debugger framework.
                                                             (line  371)
* set_charset() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  238)
* set_children() (tkinter.ttk.Treeview metodo): ttk Treeview.
                                                             (line   25)
* set_ciphers() (ssl.SSLContext metodo): SSL Contexts.       (line  238)
* set_completer_delims() (nel modulo readline): Completion.  (line   50)
* set_completer() (nel modulo readline): Completion.         (line   14)
* set_completion_display_matches_hook() (nel modulo readline): Completion.
                                                             (line   59)
* set_content() (email.contentmanager.ContentManager metodo): email contentmanager Managing MIME Content.
                                                             (line   40)
* set_content() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  590)
* set_content() (nel modulo email.contentmanager): Content Manager Instances.
                                                             (line   35)
* set_continue() (bdb.Bdb metodo):       bdb — Debugger framework.
                                                             (line  356)
* set_cookie_if_ok() (http.cookiejar.CookieJar metodo): CookieJar and FileCookieJar Objects.
                                                             (line   69)
* set_cookie() (http.cookiejar.CookieJar metodo): CookieJar and FileCookieJar Objects.
                                                             (line   73)
* set_coroutine_origin_tracking_depth() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line 1868)
* set_data() (importlib.abc.SourceLoader metodo): importlib abc – Abstract base classes related to import.
                                                             (line  391)
* set_data() (importlib.machinery.SourceFileLoader metodo): importlib machinery – Importers and path hooks.
                                                             (line  231)
* set_date() (mailbox.MaildirMessage metodo): MaildirMessage objects.
                                                             (line   97)
* set_debug() (asyncio.loop metodo):     Enabling debug mode.
                                                             (line   14)
* set_debug() (nel modulo gc):           gc — Garbage Collector interface.
                                                             (line   63)
* set_debuglevel() (ftplib.FTP metodo):  FTP objects.        (line   74)
* set_debuglevel() (http.client.HTTPConnection metodo): HTTPConnection Objects.
                                                             (line   93)
* set_debuglevel() (poplib.POP3 metodo): POP3 Objects.       (line   11)
* set_debuglevel() (smtplib.SMTP metodo): SMTP Objects.      (line    8)
* set_default_backend() (nel modulo pdb): Command-line interface<8>.
                                                             (line  155)
* set_default_executor() (asyncio.loop metodo): Executing code in thread or process pools.
                                                             (line   81)
* set_default_type() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  342)
* set_default_type() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  453)
* set_default_verify_paths() (ssl.SSLContext metodo): SSL Contexts.
                                                             (line  229)
* set_defaults() (argparse.ArgumentParser metodo): Parser defaults.
                                                             (line    6)
* set_defaults() (optparse.OptionParser metodo): Other methods.
                                                             (line   27)
* set_ecdh_curve() (ssl.SSLContext metodo): SSL Contexts.    (line  366)
* set_errno() (nel modulo ctypes):       Utility functions.  (line  245)
* set_error_mode() (nel modulo msvcrt):  Other Functions.    (line   12)
* set_escdelay() (nel modulo curses):    Functions<5>.       (line  470)
* set_event_loop_policy() (nel modulo asyncio): Getting and Setting the Policy.
                                                             (line   16)
* set_event_loop() (asyncio.AbstractEventLoopPolicy metodo): Policy Objects.
                                                             (line   23)
* set_event_loop() (nel modulo asyncio): Event Loop.         (line   67)
* set_events() (nel modulo sys.monitoring): Setting events globally.
                                                             (line   13)
* set_exception_handler() (asyncio.loop metodo): Error Handling API.
                                                             (line    8)
* set_exception() (asyncio.Future metodo): Future Object.    (line   56)
* set_exception() (concurrent.futures.Future metodo): Future Objects.
                                                             (line  117)
* set_executable() (nel modulo multiprocessing): Miscellaneous<4>.
                                                             (line  118)
* set_filter() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line  127)
* set_flags() (mailbox.Maildir metodo):  Maildir objects.    (line  110)
* set_flags() (mailbox.MaildirMessage metodo): MaildirMessage objects.
                                                             (line   72)
* set_flags() (mailbox.mboxMessage metodo): mboxMessage objects.
                                                             (line   72)
* set_flags() (mailbox.MMDFMessage metodo): MMDFMessage objects.
                                                             (line   71)
* set_forkserver_preload() (nel modulo multiprocessing): Miscellaneous<4>.
                                                             (line  134)
* set_from() (mailbox.mboxMessage metodo): mboxMessage objects.
                                                             (line   53)
* set_from() (mailbox.MMDFMessage metodo): MMDFMessage objects.
                                                             (line   52)
* SET_FUNCTION_ATTRIBUTE (opcode):       Python Bytecode Instructions.
                                                             (line 1165)
* set_handle_inheritable() (nel modulo os): Inheritance of File Descriptors.
                                                             (line   42)
* set_history_length() (nel modulo readline): History file.  (line   40)
* set_info() (mailbox.Maildir metodo):   Maildir objects.    (line  172)
* set_info() (mailbox.MaildirMessage metodo): MaildirMessage objects.
                                                             (line  108)
* set_inheritable() (nel modulo os):     Inheritance of File Descriptors.
                                                             (line   32)
* set_inheritable() (socket.socket metodo): Socket Objects.  (line  529)
* set_int_max_str_digits() (nel modulo sys): sys — System-specific parameters and functions.
                                                             (line 1645)
* set_labels() (mailbox.BabylMessage metodo): BabylMessage objects.
                                                             (line   51)
* set_last_error() (nel modulo ctypes):  Utility functions.  (line  254)
* set_local_events() (nel modulo sys.monitoring): Per code object events.
                                                             (line   16)
* set_memlimit() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  325)
* set_name() (asyncio.Task metodo):      Task Object.        (line  187)
* set_next() (bdb.Bdb metodo):           bdb — Debugger framework.
                                                             (line  334)
* set_nonstandard_attr() (http.cookiejar.Cookie metodo): Cookie Objects<2>.
                                                             (line  107)
* set_npn_protocols() (ssl.SSLContext metodo): SSL Contexts. (line  267)
* set_ok() (http.cookiejar.CookiePolicy metodo): CookiePolicy Objects.
                                                             (line    9)
* set_param() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  351)
* set_param() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  521)
* set_pasv() (ftplib.FTP metodo):        FTP objects.        (line  214)
* set_payload() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  227)
* set_pledged_input_size() (compression.zstd.ZstdCompressor metodo): Compressing and decompressing data in memory.
                                                             (line  108)
* set_policy() (http.cookiejar.CookieJar metodo): CookieJar and FileCookieJar Objects.
                                                             (line   57)
* set_pre_input_hook() (nel modulo readline): Startup hooks. (line   14)
* set_progress_handler() (sqlite3.Connection metodo): Connection objects.
                                                             (line  379)
* set_protocol() (asyncio.BaseTransport metodo): Base Transport.
                                                             (line   81)
* set_proxy() (urllib.request.Request metodo): Request Objects.
                                                             (line  115)
* set_psk_client_callback() (ssl.SSLContext metodo): SSL Contexts.
                                                             (line  661)
* set_psk_server_callback() (ssl.SSLContext metodo): SSL Contexts.
                                                             (line  713)
* set_quit() (bdb.Bdb metodo):           bdb — Debugger framework.
                                                             (line  361)
* set_result() (asyncio.Future metodo):  Future Object.      (line   49)
* set_result() (concurrent.futures.Future metodo): Future Objects.
                                                             (line  105)
* set_return() (bdb.Bdb metodo):         bdb — Debugger framework.
                                                             (line  338)
* set_running_or_notify_cancel() (concurrent.futures.Future metodo): Future Objects.
                                                             (line   85)
* set_selection() (tkinter.filedialog.FileDialog metodo): Native Load/Save Dialogs.
                                                             (line  131)
* set_seq1() (difflib.SequenceMatcher metodo): SequenceMatcher Objects.
                                                             (line   54)
* set_seq2() (difflib.SequenceMatcher metodo): SequenceMatcher Objects.
                                                             (line   59)
* set_seqs() (difflib.SequenceMatcher metodo): SequenceMatcher Objects.
                                                             (line   44)
* set_sequences() (mailbox.MH metodo):   MH objects.         (line   61)
* set_sequences() (mailbox.MHMessage metodo): MHMessage objects.
                                                             (line   37)
* set_server_documentation() (xmlrpc.server.DocCGIXMLRPCRequestHandler metodo): DocCGIXMLRPCRequestHandler.
                                                             (line   24)
* set_server_documentation() (xmlrpc.server.DocXMLRPCServer metodo): DocXMLRPCServer Objects.
                                                             (line   24)
* set_server_name() (xmlrpc.server.DocCGIXMLRPCRequestHandler metodo): DocCGIXMLRPCRequestHandler.
                                                             (line   18)
* set_server_name() (xmlrpc.server.DocXMLRPCServer metodo): DocXMLRPCServer Objects.
                                                             (line   18)
* set_server_title() (xmlrpc.server.DocCGIXMLRPCRequestHandler metodo): DocCGIXMLRPCRequestHandler.
                                                             (line   13)
* set_server_title() (xmlrpc.server.DocXMLRPCServer metodo): DocXMLRPCServer Objects.
                                                             (line   13)
* set_servername_callback() (ssl.SSLContext metodo): SSL Contexts.
                                                             (line  338)
* set_start_method() (nel modulo multiprocessing): Miscellaneous<4>.
                                                             (line  151)
* set_startup_hook() (nel modulo readline): Startup hooks.   (line    6)
* set_step() (bdb.Bdb metodo):           bdb — Debugger framework.
                                                             (line  330)
* set_subdir() (mailbox.MaildirMessage metodo): MaildirMessage objects.
                                                             (line   58)
* set_tabsize() (nel modulo curses):     Functions<5>.       (line  485)
* set_task_factory() (asyncio.loop metodo): Creating Futures and Tasks.
                                                             (line   58)
* set_threshold() (nel modulo gc):       gc — Garbage Collector interface.
                                                             (line  112)
* set_trace_async() (nel modulo pdb):    Command-line interface<8>.
                                                             (line  126)
* set_trace_callback() (sqlite3.Connection metodo): Connection objects.
                                                             (line  397)
* set_trace() (bdb.Bdb metodo):          bdb — Debugger framework.
                                                             (line  347)
* set_trace() (nel modulo bdb):          bdb — Debugger framework.
                                                             (line  530)
* set_trace() (nel modulo pdb):          Command-line interface<8>.
                                                             (line  109)
* set_trace() (pdb.Pdb metodo):          Command-line interface<8>.
                                                             (line  240)
* set_tunnel() (http.client.HTTPConnection metodo): HTTPConnection Objects.
                                                             (line  103)
* set_type() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  554)
* set_unittest_reportflags() (nel modulo doctest): Unittest API.
                                                             (line  169)
* set_unixfrom() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  146)
* set_unixfrom() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  158)
* set_until() (bdb.Bdb metodo):          bdb — Debugger framework.
                                                             (line  342)
* SET_UPDATE (opcode):                   Python Bytecode Instructions.
                                                             (line  743)
* set_url() (urllib.robotparser.RobotFileParser metodo): urllib robotparser — Parser for robots txt.
                                                             (line   21)
* set_usage() (optparse.OptionParser metodo): Other methods. (line    8)
* set_userptr() (curses.panel.Panel metodo): Panel Objects.  (line   43)
* set_visible() (mailbox.BabylMessage metodo): BabylMessage objects.
                                                             (line   68)
* set_wakeup_fd() (nel modulo signal):   Module contents<2>. (line  471)
* set_write_buffer_limits() (asyncio.WriteTransport metodo): Write-only Transports.
                                                             (line   33)
* set;comprehensions:                    Set displays.       (line    6)
* set;display:                           Set displays.       (line    6)
* set() (asyncio.Event metodo):          Event.              (line   51)
* set() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  286)
* set() (configparser.RawConfigParser metodo): RawConfigParser Objects.
                                                             (line   55)
* set() (contextvars.ContextVar metodo): Context Variables.  (line   46)
* set() (http.cookies.Morsel metodo):    Morsel Objects.     (line   75)
* set() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  240)
* set() (test.support.os_helper.EnvironmentVarGuard metodo): test support os_helper — Utilities for os tests.
                                                             (line   66)
* set() (threading.Event metodo):        Event objects.      (line   31)
* set() (tkinter.ttk.Combobox metodo):   ttk Combobox.       (line   19)
* set() (tkinter.ttk.Spinbox metodo):    ttk Spinbox.        (line   12)
* set() (tkinter.ttk.Treeview metodo):   ttk Treeview.       (line  285)
* set() (xml.etree.ElementTree.Element metodo): Element Objects.
                                                             (line   81)
* setacl() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line  336)
* SetAllocTrackerActivationThreshold() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  121)
* SetAllocTrackerMaximumAmplification() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  136)
* setannotation() (imaplib.IMAP4 metodo): IMAP4 Objects.     (line  341)
* setattrfunc (C type):                  Slot Type typedefs. (line   48)
* setAttribute() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   67)
* setAttributeNode() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   71)
* setAttributeNodeNS() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   79)
* setAttributeNS() (xml.dom.Element metodo): Element Objects<2>.
                                                             (line   87)
* setattrofunc (C type):                 Slot Type typedefs. (line   61)
* SetBase() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line   22)
* setblocking() (socket.socket metodo):  Socket Objects.     (line  536)
* setByteStream() (xml.sax.xmlreader.InputSource metodo): InputSource Objects.
                                                             (line   36)
* setcbreak() (nel modulo tty):          tty — Terminal control functions.
                                                             (line   54)
* setCharacterStream() (xml.sax.xmlreader.InputSource metodo): InputSource Objects.
                                                             (line   55)
* SetComp (classe in ast):               Comprehensions.     (line    6)
* setcomptype() (wave.Wave_write metodo): Wave_write Objects.
                                                             (line   59)
* setconfig() (sqlite3.Connection metodo): Connection objects.
                                                             (line  662)
* setContentHandler() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   25)
* setcontext() (nel modulo decimal):     Context objects.    (line   18)
* setDaemon() (threading.Thread metodo): Thread objects.     (line  253)
* setdefault() (dict metodo):            Tipi di Mapping — dict.
                                                             (line  235)
* setdefault() (http.cookies.Morsel metodo): Morsel Objects. (line  120)
* setdefaulttimeout() (nel modulo socket): Other functions<2>.
                                                             (line  382)
* setdlopenflags() (nel modulo sys):     sys — System-specific parameters and functions.
                                                             (line 1632)
* setDocumentLocator() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line   10)
* setDTDHandler() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   34)
* setegid() (nel modulo os):             Process Parameters. (line  401)
* setEncoding() (xml.sax.xmlreader.InputSource metodo): InputSource Objects.
                                                             (line   22)
* setEntityResolver() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   43)
* setErrorHandler() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   54)
* seteuid() (nel modulo os):             Process Parameters. (line  407)
* setFeature() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   76)
* setfirstweekday() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line   54)
* setfirstweekday() (nel modulo calendar): calendar — General calendar-related functions.
                                                             (line  349)
* setFormatter() (logging.Handler metodo): Handler Objects.  (line   48)
* setframerate() (wave.Wave_write metodo): Wave_write Objects.
                                                             (line   45)
* setgid() (nel modulo os):              Process Parameters. (line  413)
* setgroups() (nel modulo os):           Process Parameters. (line  419)
* seth() (nel modulo turtle):            Turtle motion.      (line  166)
* setheading() (nel modulo turtle):      Turtle motion.      (line  166)
* sethostname() (nel modulo socket):     Other functions<2>. (line  389)
* setinputsizes() (sqlite3.Cursor metodo): Cursor objects.   (line  166)
* setitem() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  217)
* setitimer() (nel modulo signal):       Module contents<2>. (line  442)
* setLevel() (logging.Handler metodo):   Handler Objects.    (line   35)
* setLevel() (logging.Logger metodo):    Logger Objects.     (line  105)
* setlimit() (sqlite3.Connection metodo): Connection objects.
                                                             (line  616)
* setlocale() (nel modulo locale):       locale — Internationalization services.
                                                             (line   27)
* setLocale() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   60)
* setLoggerClass() (nel modulo logging): Module-Level Functions.
                                                             (line  323)
* setlogmask() (nel modulo syslog):      syslog — Unix syslog library routines.
                                                             (line   98)
* setLogRecordFactory() (nel modulo logging): Module-Level Functions.
                                                             (line  334)
* setMaxConns() (urllib.request.CacheFTPHandler metodo): CacheFTPHandler Objects.
                                                             (line   13)
* setmode() (nel modulo msvcrt):         File Operations.    (line   38)
* setName() (threading.Thread metodo):   Thread objects.     (line  197)
* setnchannels() (wave.Wave_write metodo): Wave_write Objects.
                                                             (line   37)
* setnframes() (wave.Wave_write metodo): Wave_write Objects. (line   52)
* setns() (nel modulo os):               Process Parameters. (line  434)
* setoutputsize() (sqlite3.Cursor metodo): Cursor objects.   (line  170)
* SetParamEntityParsing() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line   54)
* setparams() (wave.Wave_write metodo):  Wave_write Objects. (line   64)
* setpassword() (zipfile.ZipFile metodo): ZipFile objects.   (line  246)
* setpgid() (nel modulo os):             Process Parameters. (line  481)
* setpgrp() (nel modulo os):             Process Parameters. (line  473)
* setpos() (nel modulo turtle):          Turtle motion.      (line   74)
* setpos() (wave.Wave_read metodo):      Wave_read Objects.  (line   83)
* setposition() (nel modulo turtle):     Turtle motion.      (line   74)
* setpriority() (nel modulo os):         Process Parameters. (line  489)
* setprofile_all_threads() (nel modulo threading): Reference<2>.
                                                             (line  142)
* setprofile() (nel modulo sys):         sys — System-specific parameters and functions.
                                                             (line 1653)
* setprofile() (nel modulo threading):   Reference<2>.       (line  136)
* setProperty() (xml.sax.xmlreader.XMLReader metodo): XMLReader Objects.
                                                             (line   90)
* setPublicId() (xml.sax.xmlreader.InputSource metodo): InputSource Objects.
                                                             (line    6)
* setquota() (imaplib.IMAP4 metodo):     IMAP4 Objects.      (line  346)
* setraw() (nel modulo tty):             tty — Terminal control functions.
                                                             (line   43)
* setrecursionlimit() (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line 1710)
* setregid() (nel modulo os):            Process Parameters. (line  506)
* SetReparseDeferralEnabled() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line   82)
* setresgid() (nel modulo os):           Process Parameters. (line  512)
* setresuid() (nel modulo os):           Process Parameters. (line  520)
* setreuid() (nel modulo os):            Process Parameters. (line  528)
* setrlimit() (nel modulo resource):     Resource Limits.    (line   31)
* setsampwidth() (wave.Wave_write metodo): Wave_write Objects.
                                                             (line   41)
* setscrreg() (curses.window metodo):    Window Objects.     (line  523)
* setsid() (nel modulo os):              Process Parameters. (line  541)
* setsockopt() (socket.socket metodo):   Socket Objects.     (line  569)
* setstate() (codecs.IncrementalDecoder metodo): IncrementalDecoder Objects.
                                                             (line   60)
* setstate() (codecs.IncrementalEncoder metodo): IncrementalEncoder Objects.
                                                             (line   51)
* setstate() (nel modulo random):        Bookkeeping functions.
                                                             (line   38)
* setstate() (random.Random metodo):     Alternative Generator.
                                                             (line   29)
* setStream() (logging.StreamHandler metodo): StreamHandler. (line   32)
* setswitchinterval (in module sys):     Thread State and the Global Interpreter Lock.
                                                             (line   16)
* setswitchinterval() (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line 1728)
* setswitchinterval() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  308)
* setSystemId() (xml.sax.xmlreader.InputSource metodo): InputSource Objects.
                                                             (line   14)
* setsyx() (nel modulo curses):          Functions<5>.       (line  493)
* setTarget() (logging.handlers.MemoryHandler metodo): MemoryHandler.
                                                             (line   69)
* setter (C type):                       Defining Getters and Setters.
                                                             (line   42)
* settimeout() (socket.socket metodo):   Socket Objects.     (line  553)
* setTimeout() (urllib.request.CacheFTPHandler metodo): CacheFTPHandler Objects.
                                                             (line    9)
* settrace_all_threads() (nel modulo threading): Reference<2>.
                                                             (line  120)
* settrace() (nel modulo sys):           sys — System-specific parameters and functions.
                                                             (line 1741)
* settrace() (nel modulo threading):     Reference<2>.       (line  114)
* setuid() (nel modulo os):              Process Parameters. (line  548)
* setundobuffer() (nel modulo turtle):   Special Turtle methods.
                                                             (line   73)
* SETUP_ANNOTATIONS (opcode):            Python Bytecode Instructions.
                                                             (line  426)
* SETUP_CLEANUP (opcode):                Python Bytecode Instructions.
                                                             (line 1463)
* setup_environ() (wsgiref.handlers.BaseHandler metodo): wsgiref handlers – server/gateway base classes.
                                                             (line  200)
* SETUP_FINALLY (opcode):                Python Bytecode Instructions.
                                                             (line 1456)
* setup_python() (venv.EnvBuilder metodo): API<2>.           (line  154)
* setup_scripts() (venv.EnvBuilder metodo): API<2>.          (line  162)
* setup_testing_defaults() (nel modulo wsgiref.util): wsgiref util – WSGI environment utilities.
                                                             (line   70)
* SETUP_WITH (opcode):                   Python Bytecode Instructions.
                                                             (line 1471)
* setup() (nel modulo turtle):           Methods specific to Screen not inherited from TurtleScreen.
                                                             (line   39)
* setup() (socketserver.BaseRequestHandler metodo): Request Handler Objects.
                                                             (line   14)
* setUp() (unittest.TestCase metodo):    Test cases.         (line   33)
* setUpClass() (unittest.TestCase metodo): Test cases.       (line   55)
* setUpModule() (nel modulo unittest):   setUpModule and tearDownModule.
                                                             (line    6)
* setupterm() (nel modulo curses):       Functions<5>.       (line  498)
* SetValue() (nel modulo winreg):        Functions<13>.      (line  419)
* SetValueEx() (nel modulo winreg):      Functions<13>.      (line  450)
* setworldcoordinates() (nel modulo turtle): Window control. (line  117)
* setx() (nel modulo turtle):            Turtle motion.      (line  138)
* setxattr() (nel modulo os):            Linux extended attributes.
                                                             (line   57)
* sety() (nel modulo turtle):            Turtle motion.      (line  152)
* SF_APPEND (nel modulo stat):           stat — Interpreting stat results.
                                                             (line  415)
* SF_ARCHIVED (nel modulo stat):         stat — Interpreting stat results.
                                                             (line  407)
* SF_DATALESS (nel modulo stat):         stat — Interpreting stat results.
                                                             (line  439)
* SF_FIRMLINK (nel modulo stat):         stat — Interpreting stat results.
                                                             (line  433)
* SF_IMMUTABLE (nel modulo stat):        stat — Interpreting stat results.
                                                             (line  411)
* SF_MNOWAIT (nel modulo os):            File Descriptor Operations.
                                                             (line  821)
* SF_NOCACHE (nel modulo os):            File Descriptor Operations.
                                                             (line  832)
* SF_NODISKIO (nel modulo os):           File Descriptor Operations.
                                                             (line  821)
* SF_NOUNLINK (nel modulo stat):         stat — Interpreting stat results.
                                                             (line  425)
* SF_RESTRICTED (nel modulo stat):       stat — Interpreting stat results.
                                                             (line  419)
* SF_SETTABLE (nel modulo stat):         stat — Interpreting stat results.
                                                             (line  385)
* SF_SNAPSHOT (nel modulo stat):         stat — Interpreting stat results.
                                                             (line  429)
* SF_SUPPORTED (nel modulo stat):        stat — Interpreting stat results.
                                                             (line  391)
* SF_SYNC (nel modulo os):               File Descriptor Operations.
                                                             (line  821)
* SF_SYNTHETIC (nel modulo stat):        stat — Interpreting stat results.
                                                             (line  399)
* sha1() (nel modulo hashlib):           Constructors.       (line   22)
* sha224() (nel modulo hashlib):         Constructors.       (line   24)
* sha256() (nel modulo hashlib):         Constructors.       (line   26)
* sha3_224() (nel modulo hashlib):       Constructors.       (line   32)
* sha3_256() (nel modulo hashlib):       Constructors.       (line   34)
* sha3_384() (nel modulo hashlib):       Constructors.       (line   36)
* sha3_512() (nel modulo hashlib):       Constructors.       (line   38)
* sha384() (nel modulo hashlib):         Constructors.       (line   28)
* sha512() (nel modulo hashlib):         Constructors.       (line   30)
* shake_128() (nel modulo hashlib):      SHAKE variable length digests.
                                                             (line    6)
* shake_256() (nel modulo hashlib):      SHAKE variable length digests.
                                                             (line    8)
* Shape (classe in turtle):              Public classes.     (line   43)
* shape (memoryview attributo):          Memory Views.       (line  493)
* shape() (nel modulo turtle):           Appearance.         (line    6)
* shapesize() (nel modulo turtle):       Appearance.         (line   52)
* shapetransform() (nel modulo turtle):  Appearance.         (line  137)
* share() (socket.socket metodo):        Socket Objects.     (line  601)
* ShareableList (classe in multiprocessing.shared_memory): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  272)
* ShareableList() (multiprocessing.managers.SharedMemoryManager metodo): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  232)
* Shared Memory:                         multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line   10)
* shared_ciphers() (ssl.SSLSocket metodo): SSL Sockets.      (line  240)
* shared_memory (sys._emscripten_info attributo): sys — System-specific parameters and functions.
                                                             (line  363)
* SharedMemory (classe in multiprocessing.shared_memory): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line   33)
* SharedMemory() (multiprocessing.managers.SharedMemoryManager metodo): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  227)
* SharedMemoryManager (classe in multiprocessing.managers): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  200)
* shearfactor() (nel modulo turtle):     Appearance.         (line   83)
* Shelf (classe in shelve):              Restrictions.       (line   27)
* shield() (nel modulo asyncio):         Shielding From Cancellation.
                                                             (line    6)
* shift_path_info() (nel modulo wsgiref.util): wsgiref util – WSGI environment utilities.
                                                             (line   40)
* shift;operazioni:                      Operazioni Bitwise sui Tipi Integer.
                                                             (line    6)
* shift() (decimal.Context metodo):      Context objects.    (line  534)
* shift() (decimal.Decimal metodo):      Decimal objects.    (line  575)
* shifting;operation:                    Shifting operations.
                                                             (line    6)
* shlex (classe in shlex):               shlex — Simple lexical analysis.
                                                             (line   92)
* shm (multiprocessing.shared_memory.ShareableList attributo): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  346)
* SHORT_TIMEOUT (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line   97)
* shortDescription() (unittest.TestCase metodo): Test cases. (line  822)
* shorten() (nel modulo textwrap):       textwrap — Text wrapping and filling.
                                                             (line   49)
* shouldFlush() (logging.handlers.BufferingHandler metodo): MemoryHandler.
                                                             (line   36)
* shouldFlush() (logging.handlers.MemoryHandler metodo): MemoryHandler.
                                                             (line   73)
* shouldRollover() (logging.handlers.RotatingFileHandler metodo): RotatingFileHandler.
                                                             (line   52)
* shouldRollover() (logging.handlers.TimedRotatingFileHandler metodo): TimedRotatingFileHandler.
                                                             (line  121)
* shouldStop (unittest.TestResult attributo): Loading and running tests.
                                                             (line  286)
* show_code() (nel modulo dis):          Analysis functions. (line   26)
* show_flag_values() (nel modulo enum):  Utilities and Decorators.
                                                             (line  102)
* show() (curses.panel.Panel metodo):    Panel Objects.      (line   49)
* show() (tkinter.commondialog.Dialog metodo): tkinter commondialog — Dialog window templates.
                                                             (line   16)
* show() (tkinter.messagebox.Message metodo): tkinter messagebox — Tkinter message prompts.
                                                             (line   82)
* showerror() (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  105)
* showinfo() (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line   91)
* showsyntaxerror() (code.InteractiveInterpreter metodo): Interactive Interpreter Objects.
                                                             (line   44)
* showtraceback() (code.InteractiveInterpreter metodo): Interactive Interpreter Objects.
                                                             (line   53)
* showturtle() (nel modulo turtle):      Visibility.         (line   15)
* showwarning() (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line   99)
* showwarning() (nel modulo warnings):   Available Functions.
                                                             (line   91)
* shuffle() (nel modulo random):         Functions for sequences.
                                                             (line   54)
* SHUT_RD (nel modulo socket):           Constants<8>.       (line  476)
* SHUT_RDWR (nel modulo socket):         Constants<8>.       (line  476)
* SHUT_WR (nel modulo socket):           Constants<8>.       (line  476)
* ShutDown:                              queue — A synchronized queue class.
                                                             (line   94)
* shutdown_asyncgens() (asyncio.loop metodo): Running and stopping the loop.
                                                             (line   56)
* shutdown_default_executor() (asyncio.loop metodo): Running and stopping the loop.
                                                             (line   77)
* shutdown() (asyncio.Queue metodo):     Queue.              (line   84)
* shutdown() (concurrent.futures.Executor metodo): Executor Objects.
                                                             (line   62)
* shutdown() (imaplib.IMAP4 metodo):     IMAP4 Objects.      (line  351)
* shutdown() (multiprocessing.managers.BaseManager metodo): Managers.
                                                             (line   86)
* shutdown() (nel modulo logging):       Module-Level Functions.
                                                             (line  312)
* shutdown() (queue.Queue metodo):       Terminating queues. (line    9)
* shutdown() (socket.socket metodo):     Socket Objects.     (line  592)
* shutdown() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line   55)
* SI (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line   70)
* side_effect (unittest.mock.Mock attributo): The Mock Class.
                                                             (line  370)
* SIG_BLOCK (nel modulo signal):         Module contents<2>. (line  259)
* SIG_DFL (nel modulo signal):           Module contents<2>. (line   45)
* SIG_IGN (nel modulo signal):           Module contents<2>. (line   53)
* SIG_SETMASK (nel modulo signal):       Module contents<2>. (line  274)
* SIG_UNBLOCK (nel modulo signal):       Module contents<2>. (line  266)
* SIGABRT (nel modulo signal):           Module contents<2>. (line   58)
* SIGALRM (nel modulo signal):           Module contents<2>. (line   62)
* SIGBREAK (nel modulo signal):          Module contents<2>. (line   68)
* SIGBUS (nel modulo signal):            Module contents<2>. (line   74)
* SIGCHLD (nel modulo signal):           Module contents<2>. (line   80)
* SIGCLD (nel modulo signal):            Module contents<2>. (line   86)
* SIGCONT (nel modulo signal):           Module contents<2>. (line   92)
* SIGFPE (nel modulo signal):            Module contents<2>. (line   98)
* SIGHUP (nel modulo signal):            Module contents<2>. (line  108)
* SIGILL (nel modulo signal):            Module contents<2>. (line  115)
* SIGINT (C macro):                      Signal Handling<2>. (line    7)
* SIGINT (C macro) <1>:                  Signal Handling<2>. (line   34)
* SIGINT (nel modulo signal):            Module contents<2>. (line  119)
* siginterrupt() (nel modulo signal):    Module contents<2>. (line  517)
* SIGKILL (nel modulo signal):           Module contents<2>. (line  125)
* Sigmasks (classe in signal):           Module contents<2>. (line   31)
* signal() (nel modulo signal):          Module contents<2>. (line  532)
* Signals (classe in signal):            Module contents<2>. (line   17)
* Signature (classe in inspect):         Introspecting callables with the Signature object.
                                                             (line   83)
* signature (inspect.BoundArguments attributo): Introspecting callables with the Signature object.
                                                             (line  383)
* signature() (nel modulo inspect):      Introspecting callables with the Signature object.
                                                             (line   12)
* sigpending() (nel modulo signal):      Module contents<2>. (line  560)
* SIGPIPE (nel modulo signal):           Module contents<2>. (line  133)
* SIGPROF (nel modulo signal):           Module contents<2>. (line  141)
* SIGQUIT (nel modulo signal):           Module contents<2>. (line  147)
* SIGSEGV (nel modulo signal):           Module contents<2>. (line  153)
* SIGSTKFLT (nel modulo signal):         Module contents<2>. (line  161)
* SIGSTOP (nel modulo signal):           Module contents<2>. (line  157)
* SIGTERM (nel modulo signal):           Module contents<2>. (line  173)
* sigtimedwait() (nel modulo signal):    Module contents<2>. (line  621)
* SIGUSR1 (nel modulo signal):           Module contents<2>. (line  177)
* SIGUSR2 (nel modulo signal):           Module contents<2>. (line  183)
* SIGVTALRM (nel modulo signal):         Module contents<2>. (line  189)
* sigwait() (nel modulo signal):         Module contents<2>. (line  575)
* sigwaitinfo() (nel modulo signal):     Module contents<2>. (line  592)
* SIGWINCH (nel modulo signal):          Module contents<2>. (line  195)
* SIGXCPU (nel modulo signal):           Module contents<2>. (line  201)
* SIMPLE (inspect.BufferFlags attributo): Buffer flags.      (line   15)
* Simple Mail Transfer Protocol:         smtplib — SMTP protocol client.
                                                             (line    8)
* simple;statement:                      Simple statements.  (line    6)
* SimpleCookie (classe in http.cookies): http cookies — HTTP state management.
                                                             (line   50)
* simplefilter() (nel modulo warnings):  Available Functions.
                                                             (line  125)
* SimpleHandler (classe in wsgiref.handlers): wsgiref handlers – server/gateway base classes.
                                                             (line   70)
* SimpleHTTPRequestHandler (classe in http.server): http server — HTTP servers.
                                                             (line  388)
* SimpleNamespace (classe in types):     Additional Utility Classes and Functions.
                                                             (line    6)
* SimpleQueue (classe in multiprocessing): Pipes and Queues. (line  224)
* SimpleQueue (classe in queue):         queue — A synchronized queue class.
                                                             (line   75)
* SimpleXMLRPCRequestHandler (classe in xmlrpc.server): xmlrpc server — Basic XML-RPC servers.
                                                             (line   65)
* SimpleXMLRPCServer (classe in xmlrpc.server): xmlrpc server — Basic XML-RPC servers.
                                                             (line   24)
* sin() (nel modulo cmath):              Trigonometric functions<2>.
                                                             (line   27)
* sin() (nel modulo math):               Trigonometric functions.
                                                             (line   35)
* single dispatch:                       Glossary.           (line 1591)
* SingleAddressHeader (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  217)
* singledispatch() (nel modulo functools): functools — Higher-order functions and operations on callable objects.
                                                             (line  477)
* singledispatchmethod (classe in functools): functools — Higher-order functions and operations on callable objects.
                                                             (line  649)
* singleton;tuple:                       Immutable sequences.
                                                             (line   29)
* sinh() (nel modulo cmath):             Hyperbolic functions<2>.
                                                             (line   27)
* sinh() (nel modulo math):              Hyperbolic functions.
                                                             (line   25)
* SIO_KEEPALIVE_VALS (nel modulo socket): Constants<8>.      (line  256)
* SIO_LOOPBACK_FAST_PATH (nel modulo socket): Constants<8>.  (line  256)
* SIO_RCVALL (nel modulo socket):        Constants<8>.       (line  256)
* site command line option; -user-base:  Command-line interface<11>.
                                                             (line   18)
* site command line option; -user-site:  Command-line interface<11>.
                                                             (line   22)
* site_maps() (urllib.robotparser.RobotFileParser metodo): urllib robotparser — Parser for robots txt.
                                                             (line   71)
* site-packages;directory:               site — Site-specific configuration hook.
                                                             (line   25)
* sitecustomize:                         I Moduli di Personalizzazione.
                                                             (line    6)
* sitecustomize <1>:                     I Moduli di Personalizzazione.
                                                             (line   20)
* sixtofour (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  317)
* size (ctypes.CField attributo):        Structured data types.
                                                             (line  272)
* size (multiprocessing.shared_memory.SharedMemory attributo): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  125)
* size (struct.Struct attributo):        Classes<2>.         (line   61)
* size (tarfile.TarInfo attributo):      TarInfo Objects.    (line   65)
* size (tracemalloc.Statistic attributo): Statistic.         (line   19)
* size (tracemalloc.StatisticDiff attributo): StatisticDiff. (line   26)
* size (tracemalloc.Trace attributo):    Trace.              (line   24)
* size_diff (tracemalloc.StatisticDiff attributo): StatisticDiff.
                                                             (line   32)
* SIZE_MAX (C macro):                    Integer Objects.    (line  292)
* size() (ftplib.FTP metodo):            FTP objects.        (line  353)
* size() (mmap.mmap metodo):             mmap — Memory-mapped file support.
                                                             (line  314)
* Sized (classe in collections.abc):     Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line   15)
* Sized (classe in typing):              Aliases to other ABCs in collections abc.
                                                             (line   69)
* sizeof_digit (sys.int_info attributo): sys — System-specific parameters and functions.
                                                             (line 1203)
* sizeof() (nel modulo ctypes):          Utility functions.  (line  265)
* SKIP (nel modulo doctest):             Option Flags.       (line   90)
* skip_if_broken_multiprocessing_synchronize() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  758)
* skip_unless_bind_unix_socket() (nel modulo test.support.socket_helper): test support socket_helper — Utilities for socket tests.
                                                             (line   59)
* skip_unless_symlink() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line  129)
* skip_unless_xattr() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line  134)
* skip() (nel modulo unittest):          Skipping tests and expected failures.
                                                             (line   85)
* skipIf() (nel modulo unittest):        Skipping tests and expected failures.
                                                             (line   90)
* skipinitialspace (csv.Dialect attributo): Dialects and Formatting Parameters.
                                                             (line   82)
* skipped (doctest.TestResults attributo): TestResults objects.
                                                             (line   16)
* skipped (unittest.TestResult attributo): Loading and running tests.
                                                             (line  261)
* skippedEntity() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line  174)
* skips (doctest.DocTestRunner attributo): DocTestRunner objects.
                                                             (line  143)
* SkipTest:                              Skipping tests and expected failures.
                                                             (line  105)
* skipTest() (unittest.TestCase metodo): Test cases.         (line   97)
* skipUnless() (nel modulo unittest):    Skipping tests and expected failures.
                                                             (line   94)
* SLASH (nel modulo token):              token — Constants used with Python parse trees.
                                                             (line  242)
* SLASHEQUAL (nel modulo token):         token — Constants used with Python parse trees.
                                                             (line  308)
* sleep() (nel modulo asyncio):          Sleeping.           (line    6)
* sleep() (nel modulo time):             Functions<4>.       (line  265)
* sleeping_retry() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  236)
* slice:                                 Slicings.           (line    6)
* slice <1>:                             Glossary.           (line 1596)
* slice (classe built-in):               Funzioni Incorporate.
                                                             (line 1864)
* Slice (classe in ast):                 Subscripting.       (line   27)
* slice;assegnazione:                    Tipi di Sequenza Mutabili.
                                                             (line   17)
* slice;operazione:                      Operazioni Comuni sulle Sequenze.
                                                             (line   22)
* slicing:                               Sequences.          (line   14)
* slicing <1>:                           Mutable sequences.  (line    6)
* slicing <2>:                           Slicings.           (line    6)
* slicing;assignment:                    Assignment statements.
                                                             (line  125)
* slow_callback_duration (asyncio.loop attributo): Enabling debug mode.
                                                             (line   21)
* SMALLEST (nel modulo test.support):    test support — Utilities for the Python test suite.
                                                             (line  207)
* SMTP (classe in smtplib):              smtplib — SMTP protocol client.
                                                             (line   21)
* SMTP (nel modulo email.policy):        email policy Policy Objects.
                                                             (line  510)
* smtp_code (smtplib.SMTPResponseException attributo): smtplib — SMTP protocol client.
                                                             (line  146)
* smtp_error (smtplib.SMTPResponseException attributo): smtplib — SMTP protocol client.
                                                             (line  150)
* SMTP_SSL (classe in smtplib):          smtplib — SMTP protocol client.
                                                             (line   75)
* SMTP;protocol:                         smtplib — SMTP protocol client.
                                                             (line    8)
* SMTPAuthenticationError:               smtplib — SMTP protocol client.
                                                             (line  189)
* SMTPConnectError:                      smtplib — SMTP protocol client.
                                                             (line  174)
* SMTPDataError:                         smtplib — SMTP protocol client.
                                                             (line  170)
* SMTPException:                         smtplib — SMTP protocol client.
                                                             (line  126)
* SMTPHandler (classe in logging.handlers): SMTPHandler.     (line   10)
* SMTPHeloError:                         smtplib — SMTP protocol client.
                                                             (line  179)
* SMTPNotSupportedError:                 smtplib — SMTP protocol client.
                                                             (line  183)
* SMTPRecipientsRefused:                 smtplib — SMTP protocol client.
                                                             (line  160)
* SMTPResponseException:                 smtplib — SMTP protocol client.
                                                             (line  140)
* SMTPSenderRefused:                     smtplib — SMTP protocol client.
                                                             (line  154)
* SMTPServerDisconnected:                smtplib — SMTP protocol client.
                                                             (line  134)
* SMTPUTF8 (nel modulo email.policy):    email policy Policy Objects.
                                                             (line  516)
* Snapshot (classe in tracemalloc):      Snapshot.           (line    6)
* SND_ALIAS (nel modulo winsound):       winsound — Sound-playing interface for Windows.
                                                             (line   49)
* SND_APPLICATION (nel modulo winsound): winsound — Sound-playing interface for Windows.
                                                             (line  130)
* SND_ASYNC (nel modulo winsound):       winsound — Sound-playing interface for Windows.
                                                             (line  111)
* SND_FILENAME (nel modulo winsound):    winsound — Sound-playing interface for Windows.
                                                             (line   44)
* SND_LOOP (nel modulo winsound):        winsound — Sound-playing interface for Windows.
                                                             (line   90)
* SND_MEMORY (nel modulo winsound):      winsound — Sound-playing interface for Windows.
                                                             (line   96)
* SND_NODEFAULT (nel modulo winsound):   winsound — Sound-playing interface for Windows.
                                                             (line  115)
* SND_NOSTOP (nel modulo winsound):      winsound — Sound-playing interface for Windows.
                                                             (line  120)
* SND_NOWAIT (nel modulo winsound):      winsound — Sound-playing interface for Windows.
                                                             (line  124)
* SND_PURGE (nel modulo winsound):       winsound — Sound-playing interface for Windows.
                                                             (line  105)
* SND_SENTRY (nel modulo winsound):      winsound — Sound-playing interface for Windows.
                                                             (line  136)
* SND_SYNC (nel modulo winsound):        winsound — Sound-playing interface for Windows.
                                                             (line  142)
* SND_SYSTEM (nel modulo winsound):      winsound — Sound-playing interface for Windows.
                                                             (line  148)
* sni_callback (ssl.SSLContext attributo): SSL Contexts.     (line  285)
* sniff() (csv.Sniffer metodo):          Module Contents<3>. (line  235)
* Sniffer (classe in csv):               Module Contents<3>. (line  228)
* SO (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line   67)
* SO_HCI_EVT_FILTER (nel modulo socket): Constants<8>.       (line  371)
* SO_HCI_PKT_FILTER (nel modulo socket): Constants<8>.       (line  371)
* SO_INCOMING_CPU (nel modulo socket):   Constants<8>.       (line  427)
* SO_REUSEPORT_LB (nel modulo socket):   Constants<8>.       (line  436)
* sock_accept() (asyncio.loop metodo):   Working with socket objects directly.
                                                             (line  108)
* SOCK_CLOEXEC (nel modulo socket):      Constants<8>.       (line   38)
* sock_connect() (asyncio.loop metodo):  Working with socket objects directly.
                                                             (line   88)
* SOCK_DGRAM (nel modulo socket):        Constants<8>.       (line   27)
* SOCK_MAX_SIZE (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  140)
* SOCK_NONBLOCK (nel modulo socket):     Constants<8>.       (line   38)
* SOCK_RAW (nel modulo socket):          Constants<8>.       (line   27)
* SOCK_RDM (nel modulo socket):          Constants<8>.       (line   27)
* sock_recv_into() (asyncio.loop metodo): Working with socket objects directly.
                                                             (line   26)
* sock_recv() (asyncio.loop metodo):     Working with socket objects directly.
                                                             (line   12)
* sock_recvfrom_into() (asyncio.loop metodo): Working with socket objects directly.
                                                             (line   48)
* sock_recvfrom() (asyncio.loop metodo): Working with socket objects directly.
                                                             (line   37)
* sock_sendall() (asyncio.loop metodo):  Working with socket objects directly.
                                                             (line   59)
* sock_sendfile() (asyncio.loop metodo): Working with socket objects directly.
                                                             (line  131)
* sock_sendto() (asyncio.loop metodo):   Working with socket objects directly.
                                                             (line   77)
* SOCK_SEQPACKET (nel modulo socket):    Constants<8>.       (line   27)
* SOCK_STREAM (nel modulo socket):       Constants<8>.       (line   27)
* socket (classe in socket):             Creating sockets.   (line    8)
* socket (socketserver.BaseServer attributo): Server Objects<2>.
                                                             (line   89)
* socket_type (socketserver.BaseServer attributo): Server Objects<2>.
                                                             (line  112)
* socket() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line  356)
* socket() (in module socket):           select — Waiting for I/O completion.
                                                             (line  145)
* SocketHandler (classe in logging.handlers): SocketHandler. (line   10)
* socketpair() (nel modulo socket):      Creating sockets.   (line   65)
* sockets (asyncio.Server attributo):    Server Objects.     (line  128)
* SocketType (nel modulo socket):        Creating sockets.   (line  188)
* soft deprecated:                       Glossary.           (line 1604)
* soft keyword:                          Soft Keywords.      (line    6)
* SOFT_KEYWORD (nel modulo token):       token — Constants used with Python parse trees.
                                                             (line  187)
* softkwlist (nel modulo keyword):       keyword — Testing for Python keywords.
                                                             (line   30)
* SOH (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   22)
* SOL_ALG (nel modulo socket):           Constants<8>.       (line  272)
* SOL_BLUETOOTH (nel modulo socket):     Constants<8>.       (line  334)
* SOL_HCI (nel modulo socket):           Constants<8>.       (line  334)
* SOL_L2CAP (nel modulo socket):         Constants<8>.       (line  334)
* SOL_RDS (nel modulo socket):           Constants<8>.       (line  243)
* SOL_RFCOMM (nel modulo socket):        Constants<8>.       (line  334)
* SOL_SCO (nel modulo socket):           Constants<8>.       (line  334)
* SOMAXCONN (nel modulo socket):         Constants<8>.       (line   54)
* sort_stats() (pstats.Stats metodo):    The Stats Class.    (line   67)
* sort() (imaplib.IMAP4 metodo):         IMAP4 Objects.      (line  360)
* sort() (list metodo):                  Liste<2>.           (line   40)
* sortdict() (nel modulo test.support):  test support — Utilities for the Python test suite.
                                                             (line  289)
* sortTestMethodsUsing (unittest.TestLoader attributo): Loading and running tests.
                                                             (line  197)
* sottoscrizione;assegnazione:           Tipi di Sequenza Mutabili.
                                                             (line   17)
* sottoscrizione;operazione:             Operazioni Comuni sulle Sequenze.
                                                             (line   22)
* source (doctest.Example attributo):    Example Objects.    (line   17)
* source (pdb command):                  Debugger commands.  (line  296)
* source (shlex.shlex attributo):        shlex Objects.      (line  151)
* source character set:                  Encoding declarations.
                                                             (line    6)
* SOURCE_DATE_EPOCH:                     zipfile.            (line   11)
* SOURCE_DATE_EPOCH <1>:                 py_compile<3>.      (line    7)
* SOURCE_DATE_EPOCH <2>:                 Library<161>.       (line  452)
* SOURCE_DATE_EPOCH <3>:                 Build<67>.          (line   15)
* SOURCE_DATE_EPOCH <4>:                 py_compile — Compile Python source files.
                                                             (line   66)
* SOURCE_DATE_EPOCH <5>:                 py_compile — Compile Python source files.
                                                             (line   82)
* SOURCE_DATE_EPOCH <6>:                 py_compile — Compile Python source files.
                                                             (line   86)
* SOURCE_DATE_EPOCH <7>:                 Command-line use.   (line   97)
* source_from_cache() (nel modulo importlib.util): importlib util – Utility code for importers.
                                                             (line   58)
* source_hash() (nel modulo importlib.util): importlib util – Utility code for importers.
                                                             (line  160)
* SOURCE_SUFFIXES (nel modulo importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line   13)
* source_to_code() (importlib.abc.InspectLoader metodo statico): importlib abc – Abstract base classes related to import.
                                                             (line  245)
* SourceFileLoader (classe in importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line  205)
* sourcehook() (shlex.shlex metodo):     shlex Objects.      (line   26)
* SourcelessFileLoader (classe in importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line  245)
* SourceLoader (classe in importlib.abc): importlib abc – Abstract base classes related to import.
                                                             (line  330)
* SP (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line  121)
* space:                                 Indentation.        (line    6)
* space;in string formatting:            Format Specification Mini-Language.
                                                             (line   77)
* span() (re.Match metodo):              Match Objects.      (line  172)
* sparse (tarfile.TarInfo attributo):    TarInfo Objects.    (line  157)
* spawn_python() (nel modulo test.support.script_helper): test support script_helper — Utilities for the Python execution tests.
                                                             (line   69)
* spawn() (nel modulo pty):              pty — Pseudo-terminal utilities.
                                                             (line   42)
* spawnl() (nel modulo os):              Process Management. (line  597)
* spawnle() (nel modulo os):             Process Management. (line  597)
* spawnlp() (nel modulo os):             Process Management. (line  597)
* spawnlpe() (nel modulo os):            Process Management. (line  597)
* spawnv() (nel modulo os):              Process Management. (line  597)
* spawnve() (nel modulo os):             Process Management. (line  597)
* spawnvp() (nel modulo os):             Process Management. (line  597)
* spawnvpe() (nel modulo os):            Process Management. (line  597)
* spazio;nella formattazione stile printf: Formattazione delle stringhe in stile printf.
                                                             (line   71)
* spazio;nella formattazione stile printf <1>: Formattazione Bytes stile printf.
                                                             (line   65)
* spec_from_file_location() (nel modulo importlib.util): importlib util – Utility code for importers.
                                                             (line  148)
* spec_from_loader() (nel modulo importlib.util): importlib util – Utility code for importers.
                                                             (line  137)
* special method:                        Glossary.           (line 1615)
* special;attribute:                     The standard type hierarchy.
                                                             (line   13)
* special;method:                        Glossary.           (line 1619)
* SpecialFileError:                      Directory and files operations.
                                                             (line   61)
* SpecialFileError <1>:                  tarfile — Read and write tar archive files.
                                                             (line  294)
* specified_attributes (xml.parsers.expat.xmlparser attributo): XMLParser Objects<2>.
                                                             (line  205)
* speed() (nel modulo turtle):           Turtle motion.      (line  336)
* Spinbox (classe in tkinter.ttk):       ttk Spinbox.        (line    6)
* SPLICE_F_MORE (nel modulo os):         File Descriptor Operations.
                                                             (line  913)
* SPLICE_F_MOVE (nel modulo os):         File Descriptor Operations.
                                                             (line  913)
* SPLICE_F_NONBLOCK (nel modulo os):     File Descriptor Operations.
                                                             (line  913)
* splice() (nel modulo os):              File Descriptor Operations.
                                                             (line  862)
* split() (BaseExceptionGroup metodo):   Exception groups.   (line   70)
* split() (bytearray metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  410)
* split() (bytes metodo):                Operazioni su Bytes e Bytearray.
                                                             (line  410)
* split() (nel modulo os.path):          os path — Common pathname manipulations.
                                                             (line  479)
* split() (nel modulo re):               Functions.          (line   80)
* split() (nel modulo shlex):            shlex — Simple lexical analysis.
                                                             (line   17)
* split() (re.Pattern metodo):           Regular Expression Objects.
                                                             (line   80)
* split() (str metodo):                  Metodi per le Stringhe.
                                                             (line  657)
* splitdrive() (nel modulo os.path):     os path — Common pathname manipulations.
                                                             (line  494)
* splitext() (nel modulo os.path):       os path — Common pathname manipulations.
                                                             (line  549)
* splitlines() (bytearray metodo):       Operazioni su Bytes e Bytearray.
                                                             (line  661)
* splitlines() (bytes metodo):           Operazioni su Bytes e Bytearray.
                                                             (line  661)
* splitlines() (str metodo):             Metodi per le Stringhe.
                                                             (line  715)
* SplitResult (classe in urllib.parse):  Structured Parse Results.
                                                             (line   55)
* SplitResultBytes (classe in urllib.parse): Structured Parse Results.
                                                             (line   82)
* splitroot() (nel modulo os.path):      os path — Common pathname manipulations.
                                                             (line  518)
* SpooledTemporaryFile (classe in tempfile): tempfile — Generate temporary files and directories.
                                                             (line  152)
* SQLITE_DBCONFIG_DEFENSIVE (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_DQS_DDL (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_DQS_DML (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_ENABLE_FKEY (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_ENABLE_QPSG (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_ENABLE_TRIGGER (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_ENABLE_VIEW (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_LEGACY_ALTER_TABLE (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_LEGACY_FILE_FORMAT (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_RESET_DATABASE (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_TRIGGER_EQP (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_TRUSTED_SCHEMA (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DBCONFIG_WRITABLE_SCHEMA (nel modulo sqlite3): Module constants.
                                                             (line  127)
* SQLITE_DENY (nel modulo sqlite3):      Module constants.   (line   49)
* sqlite_errorcode (sqlite3.Error attributo): Exceptions<6>. (line   24)
* sqlite_errorname (sqlite3.Error attributo): Exceptions<6>. (line   30)
* SQLITE_IGNORE (nel modulo sqlite3):    Module constants.   (line   49)
* SQLITE_OK (nel modulo sqlite3):        Module constants.   (line   49)
* sqlite_version (nel modulo sqlite3):   Module constants.   (line   78)
* sqlite_version_info (nel modulo sqlite3): Module constants.
                                                             (line   83)
* sqrt() (decimal.Context metodo):       Context objects.    (line  538)
* sqrt() (decimal.Decimal metodo):       Decimal objects.    (line  586)
* sqrt() (nel modulo cmath):             Power and logarithmic functions.
                                                             (line   22)
* sqrt() (nel modulo math):              Power exponential and logarithmic functions.
                                                             (line   90)
* ssizeargfunc (C type):                 Slot Type typedefs. (line  124)
* ssizeobjargproc (C type):              Slot Type typedefs. (line  128)
* SSL:                                   ssl — TLS/SSL wrapper for socket objects.
                                                             (line    8)
* ssl_version (ftplib.FTP_TLS attributo): FTP_TLS objects.   (line   83)
* SSLCertVerificationError:              Exceptions<18>.     (line   79)
* SSLContext (classe in ssl):            SSL Contexts.       (line   14)
* SSLEOFError:                           Exceptions<18>.     (line   71)
* SSLError:                              Exceptions<18>.     (line    6)
* SSLErrorNumber (classe in ssl):        Constants<9>.       (line  555)
* SSLKEYLOGFILE:                         Context creation.   (line   34)
* SSLKEYLOGFILE <1>:                     Context creation.   (line   83)
* SSLObject (classe in ssl):             Memory BIO Support<2>.
                                                             (line   30)
* sslobject_class (ssl.SSLContext attributo): SSL Contexts.  (line  472)
* SSLSession (classe in ssl):            SSL session.        (line    8)
* SSLSocket (classe in ssl):             SSL Sockets.        (line    6)
* sslsocket_class (ssl.SSLContext attributo): SSL Contexts.  (line  446)
* SSLSyscallError:                       Exceptions<18>.     (line   62)
* SSLv3 (ssl.TLSVersion attributo):      Constants<9>.       (line  577)
* SSLWantReadError:                      Exceptions<18>.     (line   44)
* SSLWantWriteError:                     Exceptions<18>.     (line   53)
* SSLZeroReturnError:                    Exceptions<18>.     (line   35)
* ST_ATIME (nel modulo stat):            stat — Interpreting stat results.
                                                             (line  164)
* st_atime (os.stat_result attributo):   Files and Directories.
                                                             (line 1194)
* st_atime_ns (os.stat_result attributo): Files and Directories.
                                                             (line 1211)
* st_birthtime (os.stat_result attributo): Files and Directories.
                                                             (line 1237)
* st_birthtime_ns (os.stat_result attributo): Files and Directories.
                                                             (line 1245)
* st_blksize (os.stat_result attributo): Files and Directories.
                                                             (line 1282)
* st_blocks (os.stat_result attributo):  Files and Directories.
                                                             (line 1277)
* st_creator (os.stat_result attributo): Files and Directories.
                                                             (line 1318)
* ST_CTIME (nel modulo stat):            stat — Interpreting stat results.
                                                             (line  172)
* st_ctime (os.stat_result attributo):   Files and Directories.
                                                             (line 1202)
* st_ctime_ns (os.stat_result attributo): Files and Directories.
                                                             (line 1225)
* ST_DEV (nel modulo stat):              stat — Interpreting stat results.
                                                             (line  143)
* st_dev (os.stat_result attributo):     Files and Directories.
                                                             (line 1170)
* st_file_attributes (os.stat_result attributo): Files and Directories.
                                                             (line 1328)
* st_flags (os.stat_result attributo):   Files and Directories.
                                                             (line 1292)
* st_fstype (os.stat_result attributo):  Files and Directories.
                                                             (line 1307)
* st_gen (os.stat_result attributo):     Files and Directories.
                                                             (line 1300)
* ST_GID (nel modulo stat):              stat — Interpreting stat results.
                                                             (line  155)
* st_gid (os.stat_result attributo):     Files and Directories.
                                                             (line 1182)
* ST_INO (nel modulo stat):              stat — Interpreting stat results.
                                                             (line  139)
* st_ino (os.stat_result attributo):     Files and Directories.
                                                             (line 1161)
* ST_MODE (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  135)
* st_mode (os.stat_result attributo):    Files and Directories.
                                                             (line 1157)
* ST_MTIME (nel modulo stat):            stat — Interpreting stat results.
                                                             (line  168)
* st_mtime (os.stat_result attributo):   Files and Directories.
                                                             (line 1198)
* st_mtime_ns (os.stat_result attributo): Files and Directories.
                                                             (line 1218)
* ST_NLINK (nel modulo stat):            stat — Interpreting stat results.
                                                             (line  147)
* st_nlink (os.stat_result attributo):   Files and Directories.
                                                             (line 1174)
* st_rdev (os.stat_result attributo):    Files and Directories.
                                                             (line 1288)
* st_reparse_tag (os.stat_result attributo): Files and Directories.
                                                             (line 1338)
* st_rsize (os.stat_result attributo):   Files and Directories.
                                                             (line 1314)
* ST_SIZE (nel modulo stat):             stat — Interpreting stat results.
                                                             (line  159)
* st_size (os.stat_result attributo):    Files and Directories.
                                                             (line 1186)
* st_type (os.stat_result attributo):    Files and Directories.
                                                             (line 1322)
* ST_UID (nel modulo stat):              stat — Interpreting stat results.
                                                             (line  151)
* st_uid (os.stat_result attributo):     Files and Directories.
                                                             (line 1178)
* st() (nel modulo turtle):              Visibility.         (line   15)
* stack (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line   75)
* stack viewer:                          Debug menu Shell window only.
                                                             (line   15)
* stack_effect() (nel modulo dis):       Analysis functions. (line  195)
* stack_size() (nel modulo _thread):     _thread — Low-level threading API.
                                                             (line  111)
* stack_size() (nel modulo threading):   Reference<2>.       (line  158)
* stack;trace:                           Traceback objects.  (line    6)
* stack() (nel modulo inspect):          The interpreter stack.
                                                             (line  173)
* stackable;streams:                     codecs — Codec registry and base classes.
                                                             (line    8)
* StackSummary (classe in traceback):    StackSummary Objects.
                                                             (line   10)
* stamp() (nel modulo turtle):           Turtle motion.      (line  280)
* Standard C:                            Formal grammar.     (line   28)
* standard input:                        Complete Python programs.
                                                             (line   25)
* standard library:                      Glossary.           (line 1622)
* standard_b64decode() (nel modulo base64): RFC 4648 Encodings.
                                                             (line   54)
* standard_b64encode() (nel modulo base64): RFC 4648 Encodings.
                                                             (line   49)
* standard;output:                       Expression statements.
                                                             (line   17)
* standend() (curses.window metodo):     Window Objects.     (line  528)
* standout() (curses.window metodo):     Window Objects.     (line  533)
* STAR (nel modulo token):               token — Constants used with Python parse trees.
                                                             (line  239)
* STAREQUAL (nel modulo token):          token — Constants used with Python parse trees.
                                                             (line  305)
* starmap_async() (multiprocessing.pool.Pool metodo): Process Pools.
                                                             (line  167)
* starmap() (multiprocessing.pool.Pool metodo): Process Pools.
                                                             (line  156)
* starmap() (nel modulo itertools):      Itertool Functions. (line  553)
* Starred (classe in ast):               Variables.          (line   40)
* start (range attributo):               Intervalli.         (line   63)
* start (slice attributo):               Funzioni Incorporate.
                                                             (line 1878)
* start (slice object attribute):        Slice objects.      (line   10)
* start (slice object attribute) <1>:    Slicings.           (line   26)
* start (UnicodeError attributo):        Concrete exceptions.
                                                             (line  463)
* start_color() (nel modulo curses):     Functions<5>.       (line  506)
* start_new_thread() (nel modulo _thread): _thread — Low-level threading API.
                                                             (line   32)
* start_ns() (xml.etree.ElementTree.TreeBuilder metodo): TreeBuilder Objects.
                                                             (line   76)
* start_server() (nel modulo asyncio):   Streams.            (line   76)
* start_serving() (asyncio.Server metodo): Server Objects.   (line   75)
* start_threads() (nel modulo test.support.threading_helper): test support threading_helper — Utilities for threading tests.
                                                             (line   22)
* start_tls() (asyncio.loop metodo):     TLS Upgrade.        (line    6)
* start_tls() (asyncio.StreamWriter metodo): StreamWriter.   (line   84)
* start_trace() (bdb.Bdb metodo):        bdb — Debugger framework.
                                                             (line  171)
* start_unix_server() (nel modulo asyncio): Streams.         (line  146)
* start() (logging.handlers.QueueListener metodo): QueueListener.
                                                             (line   81)
* start() (multiprocessing.managers.BaseManager metodo): Managers.
                                                             (line   59)
* start() (multiprocessing.Process metodo): Process and exceptions.
                                                             (line   91)
* start() (nel modulo tracemalloc):      Functions<10>.      (line   68)
* start() (re.Match metodo):             Match Objects.      (line  147)
* start() (threading.Thread metodo):     Thread objects.     (line  106)
* start() (tkinter.ttk.Progressbar metodo): ttk Progressbar. (line    8)
* start() (xml.etree.ElementTree.TreeBuilder metodo): TreeBuilder Objects.
                                                             (line   43)
* StartBoundaryNotFoundDefect:           email errors Exception and Defect classes.
                                                             (line   80)
* startCDATA() (xml.sax.handler.LexicalHandler metodo): LexicalHandler Objects.
                                                             (line   32)
* StartCdataSectionHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  391)
* StartDoctypeDeclHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  274)
* startDocument() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line   32)
* startDTD() (xml.sax.handler.LexicalHandler metodo): LexicalHandler Objects.
                                                             (line   23)
* startElement() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line   82)
* StartElementHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  312)
* startElementNS() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line  101)
* STARTF_FORCEOFFFEEDBACK (nel modulo subprocess): Windows Constants.
                                                             (line   47)
* STARTF_FORCEONFEEDBACK (nel modulo subprocess): Windows Constants.
                                                             (line   38)
* STARTF_USESHOWWINDOW (nel modulo subprocess): Windows Constants.
                                                             (line   33)
* STARTF_USESTDHANDLES (nel modulo subprocess): Windows Constants.
                                                             (line   27)
* startfile() (nel modulo os):           Process Management. (line  715)
* StartNamespaceDeclHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  370)
* startPrefixMapping() (xml.sax.handler.ContentHandler metodo): ContentHandler Objects.
                                                             (line   49)
* StartResponse (classe in wsgiref.types): wsgiref types – WSGI types for static type checking.
                                                             (line   11)
* startswith() (bytearray metodo):       Operazioni su Bytes e Bytearray.
                                                             (line  262)
* startswith() (bytes metodo):           Operazioni su Bytes e Bytearray.
                                                             (line  262)
* startswith() (str metodo):             Metodi per le Stringhe.
                                                             (line  790)
* startTest() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  349)
* startTestRun() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  358)
* starttls() (imaplib.IMAP4 metodo):     IMAP4 Objects.      (line  378)
* starttls() (smtplib.SMTP metodo):      SMTP Objects.       (line  185)
* STARTUPINFO (classe in subprocess):    Windows Popen Helpers.
                                                             (line    9)
* stat_result (classe in os):            Files and Directories.
                                                             (line 1149)
* stat() (nel modulo os):                Files and Directories.
                                                             (line 1093)
* stat() (os.DirEntry metodo):           Files and Directories.
                                                             (line 1056)
* stat() (pathlib.Path metodo):          Querying file type and status.
                                                             (line   21)
* stat() (poplib.POP3 metodo):           POP3 Objects.       (line   52)
* state() (tkinter.ttk.Widget metodo):   ttk Widget.         (line   25)
* statement:                             Glossary.           (line 1634)
* statement grouping:                    Indentation.        (line    6)
* statement;assert:                      The assert statement.
                                                             (line    6)
* statement;assert <1>:                  Concrete exceptions.
                                                             (line   10)
* statement;assignment, annotated:       Annotated assignment statements.
                                                             (line    6)
* statement;assignment, augmented:       Augmented assignment statements.
                                                             (line    6)
* statement;async def:                   Coroutines<2>.      (line    8)
* statement;async for:                   Coroutine function definition.
                                                             (line   29)
* statement;async with:                  The async for statement.
                                                             (line   43)
* statement;break:                       The break statement.
                                                             (line    6)
* statement;break <1>:                   The while statement.
                                                             (line   17)
* statement;break <2>:                   The for statement.  (line   21)
* statement;break <3>:                   except* clause.     (line   66)
* statement;break <4>:                   finally clause.     (line   26)
* statement;class:                       Class definitions.  (line    6)
* statement;continue:                    The continue statement.
                                                             (line    6)
* statement;continue <1>:                The while statement.
                                                             (line   17)
* statement;continue <2>:                The for statement.  (line   21)
* statement;continue <3>:                except* clause.     (line   65)
* statement;continue <4>:                finally clause.     (line   26)
* statement;def:                         Function definitions.
                                                             (line    6)
* statement;del:                         Basic customization.
                                                             (line   55)
* statement;del <1>:                     The del statement.  (line    6)
* statement;except:                      Built-in Exceptions.
                                                             (line    6)
* statement;for:                         The break statement.
                                                             (line    6)
* statement;for <1>:                     The continue statement.
                                                             (line    6)
* statement;for <2>:                     The for statement.  (line    6)
* statement;global:                      The del statement.  (line   15)
* statement;global <1>:                  The global statement.
                                                             (line    6)
* statement;if:                          The if statement.   (line    6)
* statement;import:                      Modules<2>.         (line    6)
* statement;import <1>:                  The import statement.
                                                             (line    6)
* statement;import <2>:                  site — Site-specific configuration hook.
                                                             (line   57)
* statement;match:                       The match statement.
                                                             (line    6)
* statement;nonlocal:                    The nonlocal statement.
                                                             (line    6)
* statement;pass:                        The pass statement. (line    6)
* statement;raise:                       The raise statement.
                                                             (line    6)
* statement;raise <1>:                   Built-in Exceptions.
                                                             (line   14)
* statement;return:                      The return statement.
                                                             (line    6)
* statement;return <1>:                  except* clause.     (line   66)
* statement;return <2>:                  finally clause.     (line   26)
* statement;try:                         Traceback objects.  (line   31)
* statement;try <1>:                     The try statement.  (line    6)
* statement;try <2>:                     Built-in Exceptions.
                                                             (line    6)
* statement;type:                        The type statement. (line    6)
* statement;while:                       The break statement.
                                                             (line    6)
* statement;while <1>:                   The continue statement.
                                                             (line    6)
* statement;while <2>:                   The while statement.
                                                             (line    6)
* statement;with:                        With Statement Context Managers.
                                                             (line   14)
* statement;with <1>:                    The with statement. (line    6)
* statement;yield:                       The yield statement.
                                                             (line    6)
* static type checker:                   Glossary.           (line 1641)
* static_order() (graphlib.TopologicalSorter metodo): graphlib — Functionality to operate with graph-like structures.
                                                             (line  170)
* Statistic (classe in tracemalloc):     Statistic.          (line    6)
* StatisticDiff (classe in tracemalloc): StatisticDiff.      (line    6)
* statistics() (tracemalloc.Snapshot metodo): Snapshot.      (line   56)
* StatisticsError:                       Exceptions<4>.      (line    8)
* Stats (classe in pstats):              The Stats Class.    (line    9)
* status (http.client.HTTPResponse attributo): HTTPResponse Objects.
                                                             (line   61)
* status (urllib.response.addinfourl attributo): urllib response — Response classes used by urllib.
                                                             (line   24)
* status() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line  391)
* statvfs() (nel modulo os):             Files and Directories.
                                                             (line 1390)
* STD_ERROR_HANDLE (nel modulo subprocess): Windows Constants.
                                                             (line   18)
* STD_INPUT_HANDLE (nel modulo subprocess): Windows Constants.
                                                             (line    8)
* STD_OUTPUT_HANDLE (nel modulo subprocess): Windows Constants.
                                                             (line   13)
* stderr (asyncio.subprocess.Process attributo): Interacting with Subprocesses.
                                                             (line  126)
* stderr (in module sys):                I/O objects also known as file objects.
                                                             (line    6)
* stderr (in module sys) <1>:            Sub-interpreter support.
                                                             (line  112)
* stderr (in module sys) <2>:            Sub-interpreter support.
                                                             (line  199)
* stderr (nel modulo sys):               sys — System-specific parameters and functions.
                                                             (line 1986)
* stderr (subprocess.CalledProcessError attributo): Using the subprocess Module.
                                                             (line  230)
* stderr (subprocess.CompletedProcess attributo): Using the subprocess Module.
                                                             (line  129)
* stderr (subprocess.Popen attributo):   Popen Objects.      (line  135)
* stderr (subprocess.TimeoutExpired attributo): Using the subprocess Module.
                                                             (line  194)
* stdev (statistics.NormalDist attributo): NormalDist objects.
                                                             (line   35)
* stdev() (nel modulo statistics):       Function details.   (line  435)
* stdin (asyncio.subprocess.Process attributo): Interacting with Subprocesses.
                                                             (line  116)
* stdin (in module sys):                 I/O objects also known as file objects.
                                                             (line    6)
* stdin (in module sys) <1>:             Sub-interpreter support.
                                                             (line  112)
* stdin (in module sys) <2>:             Sub-interpreter support.
                                                             (line  199)
* stdin (nel modulo sys):                sys — System-specific parameters and functions.
                                                             (line 1986)
* stdin (subprocess.Popen attributo):    Popen Objects.      (line  116)
* stdio:                                 I/O objects also known as file objects.
                                                             (line    6)
* stdlib:                                Glossary.           (line 1647)
* stdlib_module_names (nel modulo sys):  sys — System-specific parameters and functions.
                                                             (line 2076)
* stdout (asyncio.subprocess.Process attributo): Interacting with Subprocesses.
                                                             (line  121)
* stdout (in module sys):                I/O objects also known as file objects.
                                                             (line    6)
* stdout (in module sys) <1>:            Sub-interpreter support.
                                                             (line  112)
* stdout (in module sys) <2>:            Sub-interpreter support.
                                                             (line  199)
* STDOUT (nel modulo subprocess):        Using the subprocess Module.
                                                             (line  157)
* stdout (nel modulo sys):               sys — System-specific parameters and functions.
                                                             (line 1986)
* stdout (subprocess.CalledProcessError attributo): Using the subprocess Module.
                                                             (line  226)
* stdout (subprocess.CompletedProcess attributo): Using the subprocess Module.
                                                             (line  119)
* stdout (subprocess.Popen attributo):   Popen Objects.      (line  125)
* stdout (subprocess.TimeoutExpired attributo): Using the subprocess Module.
                                                             (line  190)
* stem (pathlib.PurePath attributo):     Methods and properties.
                                                             (line  167)
* step (pdb command):                    Debugger commands.  (line  207)
* step (range attributo):                Intervalli.         (line   72)
* step (slice attributo):                Funzioni Incorporate.
                                                             (line 1882)
* step (slice object attribute):         Slice objects.      (line   10)
* step (slice object attribute) <1>:     Slicings.           (line   26)
* step() (tkinter.ttk.Progressbar metodo): ttk Progressbar.  (line   15)
* stls() (poplib.POP3 metodo):           POP3 Objects.       (line  114)
* stop (range attributo):                Intervalli.         (line   68)
* stop (slice attributo):                Funzioni Incorporate.
                                                             (line 1880)
* stop (slice object attribute):         Slice objects.      (line   10)
* stop (slice object attribute) <1>:     Slicings.           (line   26)
* stop_here() (bdb.Bdb metodo):          bdb — Debugger framework.
                                                             (line  275)
* STOP_ITERATION (monitoring event):     Events.             (line   92)
* stop_trace() (bdb.Bdb metodo):         bdb — Debugger framework.
                                                             (line  178)
* stop() (asyncio.loop metodo):          Running and stopping the loop.
                                                             (line   31)
* stop() (logging.handlers.QueueListener metodo): QueueListener.
                                                             (line   91)
* stop() (nel modulo tracemalloc):       Functions<10>.      (line   98)
* stop() (tkinter.ttk.Progressbar metodo): ttk Progressbar.  (line   21)
* stop() (unittest.TestResult metodo):   Loading and running tests.
                                                             (line  329)
* StopAsyncIteration:                    Concrete exceptions.
                                                             (line  305)
* StopIteration:                         Concrete exceptions.
                                                             (line  272)
* stopListening() (nel modulo logging.config): Configuration functions.
                                                             (line  174)
* stopTest() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  353)
* stopTestRun() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  364)
* storbinary() (ftplib.FTP metodo):      FTP objects.        (line  219)
* Store (classe in ast):                 Variables.          (line   11)
* STORE_ACTIONS (optparse.Option attributo): Adding new actions.
                                                             (line   35)
* STORE_ATTR (opcode):                   Python Bytecode Instructions.
                                                             (line  590)
* STORE_DEREF (opcode):                  Python Bytecode Instructions.
                                                             (line 1038)
* STORE_FAST (opcode):                   Python Bytecode Instructions.
                                                             (line  988)
* STORE_FAST_LOAD_FAST (opcode):         Python Bytecode Instructions.
                                                             (line  999)
* STORE_FAST_STORE_FAST (opcode):        Python Bytecode Instructions.
                                                             (line  992)
* STORE_GLOBAL (opcode):                 Python Bytecode Instructions.
                                                             (line  611)
* STORE_NAME (opcode):                   Python Bytecode Instructions.
                                                             (line  548)
* STORE_SLICE (opcode):                  Python Bytecode Instructions.
                                                             (line  298)
* STORE_SUBSCR (opcode):                 Python Bytecode Instructions.
                                                             (line  270)
* store() (imaplib.IMAP4 metodo):        IMAP4 Objects.      (line  395)
* storlines() (ftplib.FTP metodo):       FTP objects.        (line  248)
* str (classe built-in):                 Tipo Sequenza di Testo — str.
                                                             (line   48)
* str (classe incorporata);(vedi anche stringa): Intervalli. (line  130)
* str_digits_check_threshold (sys.int_info attributo): sys — System-specific parameters and functions.
                                                             (line 1212)
* str() (nel modulo locale):             locale — Internationalization services.
                                                             (line  505)
* Strategy (classe in compression.zstd): Advanced parameter control.
                                                             (line  296)
* strategy (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  121)
* strcoll() (nel modulo locale):         locale — Internationalization services.
                                                             (line  457)
* StreamError:                           tarfile — Read and write tar archive files.
                                                             (line  260)
* StreamHandler (classe in logging):     StreamHandler.      (line   11)
* StreamReader (classe in asyncio):      StreamReader.       (line    6)
* StreamReader (classe in codecs):       StreamReader Objects.
                                                             (line   10)
* streamreader (codecs.CodecInfo attributo): codecs — Codec registry and base classes.
                                                             (line   96)
* StreamReaderWriter (classe in codecs): StreamReaderWriter Objects.
                                                             (line   12)
* StreamRecoder (classe in codecs):      StreamRecoder Objects.
                                                             (line   13)
* StreamRequestHandler (classe in socketserver): Request Handler Objects.
                                                             (line   56)
* streams:                               codecs — Codec registry and base classes.
                                                             (line    8)
* StreamWriter (classe in asyncio):      StreamWriter.       (line    6)
* StreamWriter (classe in codecs):       StreamWriter Objects.
                                                             (line   10)
* streamwriter (codecs.CodecInfo attributo): codecs — Codec registry and base classes.
                                                             (line   96)
* StrEnum (classe in enum):              Data Types<2>.      (line  398)
* strerror (C function):                 Raising exceptions. (line   62)
* strerror (OSError attributo):          Concrete exceptions.
                                                             (line  189)
* strerror() (nel modulo os):            Process Parameters. (line  554)
* strftime() (datetime.date metodo):     date Objects.       (line  330)
* strftime() (datetime.datetime metodo): datetime Objects.   (line  755)
* strftime() (datetime.time metodo):     time Objects.       (line  239)
* strftime() (nel modulo time):          Functions<4>.       (line  320)
* strict (csv.Dialect attributo):        Dialects and Formatting Parameters.
                                                             (line   89)
* STRICT (enum.FlagBoundary attributo):  Data Types<2>.      (line  676)
* strict (nel modulo email.policy):      email policy Policy Objects.
                                                             (line  531)
* strict_domain (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line   95)
* strict_errors() (nel modulo codecs):   Error Handlers.     (line  141)
* strict_ns_domain (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line  117)
* strict_ns_set_initial_dollar (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line  122)
* strict_ns_set_path (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line  127)
* strict_ns_unverifiable (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line  112)
* strict_rfc2965_unverifiable (http.cookiejar.DefaultCookiePolicy attributo): DefaultCookiePolicy Objects.
                                                             (line  103)
* strict;error handler's name:           Error Handlers.     (line   15)
* STRIDED (inspect.BufferFlags attributo): Buffer flags.     (line   37)
* STRIDED_RO (inspect.BufferFlags attributo): Buffer flags.  (line   39)
* STRIDES (inspect.BufferFlags attributo): Buffer flags.     (line   23)
* strides (memoryview attributo):        Memory Views.       (line  502)
* STRING (annotationlib.Format attributo): Classes<4>.       (line   37)
* STRING (nel modulo token):             token — Constants used with Python parse trees.
                                                             (line   54)
* string (re.Match attributo):           Match Objects.      (line  211)
* string literal:                        Literals.           (line   15)
* string_at() (nel modulo ctypes):       Utility functions.  (line  270)
* string;__format__() (object method):   Basic customization.
                                                             (line  153)
* string;__str__() (object method):      Basic customization.
                                                             (line  131)
* string;conversion:                     Basic customization.
                                                             (line  153)
* string;conversion <1>:                 Expression statements.
                                                             (line   17)
* string;formatted literal:              Formattazione Avanzata dell’Output.
                                                             (line   98)
* string;formatted literal <1>:          Raw string literals.
                                                             (line   25)
* string;immutable sequences:            Immutable sequences.
                                                             (line   13)
* string;interpolated literal:           Formattazione Avanzata dell’Output.
                                                             (line   98)
* string;interpolated literal <1>:       Raw string literals.
                                                             (line   25)
* string;item:                           Subscriptions.      (line   58)
* string;object representation:          Finalization and De-allocation.
                                                             (line   95)
* string;PyObject_Str (C function):      Object Protocol.    (line  354)
* stringa;format() (funzione incorporata): Funzioni Incorporate.
                                                             (line  819)
* stringa;formattazione, printf:         Formattazione delle stringhe in stile printf.
                                                             (line    6)
* stringa;formatted literal:             Metodi per le Stringhe.
                                                             (line  912)
* stringa;interpolated literal:          Metodi per le Stringhe.
                                                             (line  912)
* stringa;interpolazione, printf:        Formattazione delle stringhe in stile printf.
                                                             (line    6)
* stringa;metodi:                        Tipo Sequenza di Testo — str.
                                                             (line   95)
* stringa;str (classe incorporata):      Tipo Sequenza di Testo — str.
                                                             (line   48)
* stringa;str() (funzione incorporata):  Funzioni Incorporate.
                                                             (line 1976)
* stringa;tipo di sequenza di testo:     Intervalli.         (line  130)
* stringhe di documentazione:            Definizione di Funzioni.
                                                             (line   21)
* stringhe di documentazione <1>:        Stringhe di Documentazione.
                                                             (line    6)
* stringhe, documentazione:              Definizione di Funzioni.
                                                             (line   21)
* stringhe, documentazione <1>:          Stringhe di Documentazione.
                                                             (line    6)
* StringIO (classe in io):               Text I/O<2>.        (line  244)
* strings (string.templatelib.Template attributo): Types.    (line   45)
* strip_dirs() (pstats.Stats metodo):    The Stats Class.    (line   34)
* strip() (bytearray metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  457)
* strip() (bytes metodo):                Operazioni su Bytes e Bytearray.
                                                             (line  457)
* strip() (str metodo):                  Metodi per le Stringhe.
                                                             (line  798)
* stripspaces (curses.textpad.Textbox attributo): Textbox objects.
                                                             (line  115)
* strong reference:                      Glossary.           (line 1651)
* strptime() (datetime.date metodo della classe): date Objects.
                                                             (line   99)
* strptime() (datetime.datetime metodo della classe): datetime Objects.
                                                             (line  255)
* strptime() (datetime.time metodo della classe): time Objects.
                                                             (line  148)
* strptime() (nel modulo time):          Functions<4>.       (line  479)
* strsignal() (nel modulo signal):       Module contents<2>. (line  323)
* Struct (classe in struct):             Classes<2>.         (line    8)
* struct_time (classe in time):          Functions<4>.       (line  513)
* structmember.h:                        Member types.       (line  121)
* Structure (classe in ctypes):          Structured data types.
                                                             (line   36)
* strxfrm() (nel modulo locale):         locale — Internationalization services.
                                                             (line  464)
* STX (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   25)
* Style (classe in tkinter.ttk):         Ttk Styling.        (line   20)
* Sub (classe in ast):                   Expressions<2>.     (line   53)
* SUB (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line  103)
* sub() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line  169)
* sub() (nel modulo re):                 Functions.          (line  171)
* sub() (re.Pattern metodo):             Regular Expression Objects.
                                                             (line   97)
* subclassing;immutable types:           Basic customization.
                                                             (line    8)
* subdirs (filecmp.dircmp attributo):    The dircmp class.   (line  104)
* SubElement() (nel modulo xml.etree.ElementTree): Functions<8>.
                                                             (line  210)
* subgroup() (BaseExceptionGroup metodo): Exception groups.  (line   43)
* submit() (concurrent.futures.Executor metodo): Executor Objects.
                                                             (line   12)
* submodule_search_locations (importlib.machinery.ModuleSpec attributo): importlib machinery – Importers and path hooks.
                                                             (line  404)
* subn() (nel modulo re):                Functions.          (line  247)
* subn() (re.Pattern metodo):            Regular Expression Objects.
                                                             (line  102)
* subnet_of() (ipaddress.IPv4Network metodo): Network objects.
                                                             (line  215)
* subnet_of() (ipaddress.IPv6Network metodo): Network objects.
                                                             (line  349)
* subnets() (ipaddress.IPv4Network metodo): Network objects. (line  173)
* subnets() (ipaddress.IPv6Network metodo): Network objects. (line  345)
* Subnormal (classe in decimal):         Signals.            (line   88)
* suboffsets (memoryview attributo):     Memory Views.       (line  511)
* subpad() (curses.window metodo):       Window Objects.     (line  537)
* subprocess_exec() (asyncio.loop metodo): Running Subprocesses.
                                                             (line   16)
* subprocess_shell() (asyncio.loop metodo): Running Subprocesses.
                                                             (line  118)
* SubprocessError:                       Using the subprocess Module.
                                                             (line  163)
* SubprocessProtocol (classe in asyncio): Base Protocols.    (line   24)
* SubprocessTransport (classe in asyncio): Transports Hierarchy.
                                                             (line   50)
* subscribe() (imaplib.IMAP4 metodo):    IMAP4 Objects.      (line  419)
* Subscript (classe in ast):             Subscripting.       (line    6)
* subscription:                          Sequences.          (line    6)
* subscription <1>:                      Mutable sequences.  (line    6)
* subscription <2>:                      Mappings.           (line    6)
* subscription <3>:                      Subscriptions.      (line    6)
* subscription;assignment:               Assignment statements.
                                                             (line  101)
* subsequent_indent (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  222)
* substitute() (string.Template metodo): Template strings $-strings.
                                                             (line   50)
* subTest() (unittest.TestCase metodo):  Test cases.         (line  105)
* subtract() (collections.Counter metodo): Counter objects.  (line   89)
* subtract() (decimal.Context metodo):   Context objects.    (line  542)
* subtraction:                           Binary arithmetic operations.
                                                             (line   89)
* subtype (email.headerregistry.ContentTypeHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  278)
* subwin() (curses.window metodo):       Window Objects.     (line  544)
* successful() (multiprocessing.pool.AsyncResult metodo): Process Pools.
                                                             (line  221)
* suffix (pathlib.PurePath attributo):   Methods and properties.
                                                             (line  137)
* suffix_map (mimetypes.MimeTypes attributo): MimeTypes objects.
                                                             (line   23)
* suffix_map (nel modulo mimetypes):     mimetypes — Map filenames to MIME types.
                                                             (line  145)
* suffixes (pathlib.PurePath attributo): Methods and properties.
                                                             (line  153)
* suite:                                 Compound statements.
                                                             (line   18)
* suiteClass (unittest.TestLoader attributo): Loading and running tests.
                                                             (line  203)
* sum_list():                            Reference Count Details.
                                                             (line  143)
* sum_sequence():                        Reference Count Details.
                                                             (line  170)
* sum_sequence() <1>:                    Exceptions<23>.     (line   65)
* summarize_address_range() (nel modulo ipaddress): Other Module Level Functions.
                                                             (line   27)
* summarize() (doctest.DocTestRunner metodo): DocTestRunner objects.
                                                             (line  123)
* sumprod() (nel modulo math):           Summation and product functions.
                                                             (line   62)
* SUNDAY (nel modulo calendar):          calendar — General calendar-related functions.
                                                             (line  447)
* super (classe built-in):               Funzioni Incorporate.
                                                             (line 2015)
* super (pyclbr.Class attributo):        Class Objects.      (line   42)
* supernet_of() (ipaddress.IPv4Network metodo): Network objects.
                                                             (line  226)
* supernet_of() (ipaddress.IPv6Network metodo): Network objects.
                                                             (line  351)
* supernet() (ipaddress.IPv4Network metodo): Network objects.
                                                             (line  199)
* supernet() (ipaddress.IPv6Network metodo): Network objects.
                                                             (line  347)
* supports_bytes_environ (nel modulo os): Process Parameters.
                                                             (line  560)
* supports_dir_fd (nel modulo os):       Files and Directories.
                                                             (line 1433)
* supports_effective_ids (nel modulo os): Files and Directories.
                                                             (line 1458)
* supports_fd (nel modulo os):           Files and Directories.
                                                             (line 1477)
* supports_follow_symlinks (nel modulo os): Files and Directories.
                                                             (line 1496)
* supports_unicode_filenames (nel modulo os.path): os path — Common pathname manipulations.
                                                             (line  579)
* SupportsAbs (classe in typing):        Protocols<4>.       (line    9)
* SupportsBytes (classe in typing):      Protocols<4>.       (line   14)
* SupportsComplex (classe in typing):    Protocols<4>.       (line   18)
* SupportsFloat (classe in typing):      Protocols<4>.       (line   22)
* SupportsIndex (classe in typing):      Protocols<4>.       (line   26)
* SupportsInt (classe in typing):        Protocols<4>.       (line   32)
* SupportsRound (classe in typing):      Protocols<4>.       (line   36)
* suppress() (nel modulo contextlib):    Utilities.          (line  268)
* SuppressCrashReport (classe in test.support): test support — Utilities for the Python test suite.
                                                             (line  786)
* surrogateescape;error handler's name:  Error Handlers.     (line   15)
* surrogatepass;error handler's name:    Error Handlers.     (line   73)
* SW_HIDE (nel modulo subprocess):       Windows Constants.  (line   23)
* SWAP (opcode):                         Python Bytecode Instructions.
                                                             (line  183)
* swap_attr() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  391)
* swap_item() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  408)
* swapcase() (bytearray metodo):         Operazioni su Bytes e Bytearray.
                                                             (line  688)
* swapcase() (bytes metodo):             Operazioni su Bytes e Bytearray.
                                                             (line  688)
* swapcase() (str metodo):               Metodi per le Stringhe.
                                                             (line  822)
* Symbol (classe in symtable):           Examining Symbol Tables.
                                                             (line  194)
* SymbolTable (classe in symtable):      Examining Symbol Tables.
                                                             (line   49)
* SymbolTableType (classe in symtable):  Examining Symbol Tables.
                                                             (line    6)
* symlink_to() (pathlib.Path metodo):    Creating files and directories.
                                                             (line   45)
* symlink() (nel modulo os):             Files and Directories.
                                                             (line 1519)
* symmetric_difference_update() (set metodo): Tipi di Insiemi — set frozenset.
                                                             (line  200)
* symmetric_difference() (frozenset metodo): Tipi di Insiemi — set frozenset.
                                                             (line  126)
* symmetric_difference() (set metodo):   Tipi di Insiemi — set frozenset.
                                                             (line  126)
* symtable() (nel modulo symtable):      Generating Symbol Tables.
                                                             (line    6)
* SYMTYPE (nel modulo tarfile):          tarfile — Read and write tar archive files.
                                                             (line  333)
* SYN (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   91)
* sync() (dbm.dumb.dumbdbm metodo):      dbm dumb — Portable DBM implementation.
                                                             (line   85)
* sync() (dbm.gnu.gdbm metodo):          dbm gnu — GNU database manager.
                                                             (line  126)
* sync() (nel modulo os):                Files and Directories.
                                                             (line 1568)
* sync() (shelve.Shelf metodo):          shelve — Python object persistence.
                                                             (line   69)
* syncdown() (curses.window metodo):     Window Objects.     (line  554)
* synchronization primitive:             Glossary.           (line 1666)
* synchronized() (nel modulo multiprocessing.sharedctypes): The multiprocessing sharedctypes module.
                                                             (line   96)
* SyncManager (classe in multiprocessing.managers): Managers.
                                                             (line  152)
* syncok() (curses.window metodo):       Window Objects.     (line  560)
* syncup() (curses.window metodo):       Window Objects.     (line  565)
* syntax:                                Notation.           (line    6)
* SyntaxErr:                             Exceptions<22>.     (line   93)
* SyntaxError:                           Concrete exceptions.
                                                             (line  312)
* SyntaxWarning:                         Warnings.           (line   43)
* sys_version (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  189)
* sys.exc_info:                          Traceback objects.  (line    6)
* sys.exception:                         Traceback objects.  (line    6)
* sys.last_traceback:                    Traceback objects.  (line    6)
* sys.meta_path:                         The meta path.      (line    6)
* sys.modules:                           The module cache.   (line    6)
* sys.path:                              Path entry finders. (line    6)
* sys.path_hooks:                        Path entry finders. (line    6)
* sys.path_importer_cache:               Path entry finders. (line    6)
* sys.stderr:                            I/O objects also known as file objects.
                                                             (line    6)
* sys.stdin:                             I/O objects also known as file objects.
                                                             (line    6)
* sys.stdout:                            I/O objects also known as file objects.
                                                             (line    6)
* sysconf_names (nel modulo os):         Miscellaneous System Information.
                                                             (line   87)
* sysconf() (nel modulo os):             Miscellaneous System Information.
                                                             (line   77)
* syslog() (nel modulo syslog):          syslog — Unix syslog library routines.
                                                             (line   20)
* SysLogHandler (classe in logging.handlers): SysLogHandler. (line   10)
* system_alias() (nel modulo platform):  Cross platform.     (line  132)
* system_must_validate_cert() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  479)
* system() (nel modulo os):              Process Management. (line  770)
* system() (nel modulo platform):        Cross platform.     (line  122)
* SystemError:                           Concrete exceptions.
                                                             (line  374)
* SystemError (built-in exception):      Module Objects.     (line   67)
* SystemError (built-in exception) <1>:  Module Objects.     (line  103)
* SystemExit:                            Concrete exceptions.
                                                             (line  391)
* SystemExit (built-in exception):       Exceptions.         (line   26)
* systemId (xml.dom.DocumentType attributo): DocumentType Objects.
                                                             (line   22)
* SystemRandom (classe in random):       Alternative Generator.
                                                             (line   52)
* SystemRandom (classe in secrets):      Random numbers.     (line    9)
* T_BOOL (C macro):                      Member types.       (line  121)
* T_BYTE (C macro):                      Member types.       (line  121)
* T_CHAR (C macro):                      Member types.       (line  121)
* T_DOUBLE (C macro):                    Member types.       (line  121)
* T_FLOAT (C macro):                     Member types.       (line  121)
* T_FMT (nel modulo locale):             locale — Internationalization services.
                                                             (line  215)
* T_FMT_AMPM (nel modulo locale):        locale — Internationalization services.
                                                             (line  221)
* T_INT (C macro):                       Member types.       (line  121)
* T_LONG (C macro):                      Member types.       (line  121)
* T_LONGLONG (C macro):                  Member types.       (line  121)
* T_NONE (C macro):                      Member types.       (line  132)
* T_OBJECT (C macro):                    Member types.       (line  126)
* T_OBJECT_EX (C macro):                 Member types.       (line  121)
* T_PYSSIZET (C macro):                  Member types.       (line  121)
* T_SHORT (C macro):                     Member types.       (line  121)
* T_STRING (C macro):                    Member types.       (line  121)
* T_STRING_INPLACE (C macro):            Member types.       (line  121)
* T_UBYTE (C macro):                     Member types.       (line  121)
* T_UINT (C macro):                      Member types.       (line  121)
* T_ULONG (C macro):                     Member types.       (line  121)
* T_ULONGULONG (C macro):                Member types.       (line  121)
* T_USHORT (C macro):                    Member types.       (line  121)
* t-string:                              Glossary.           (line 1679)
* t-strings:                             Glossary.           (line 1682)
* tab:                                   Indentation.        (line    6)
* TAB (nel modulo curses.ascii):         curses ascii — Utilities for ASCII characters.
                                                             (line   46)
* tab() (tkinter.ttk.Notebook metodo):   ttk Notebook.       (line   62)
* TabError:                              Concrete exceptions.
                                                             (line  369)
* tabs() (tkinter.ttk.Notebook metodo):  ttk Notebook.       (line   71)
* tabsize (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  179)
* tag (xml.etree.ElementTree.Element attributo): Element Objects.
                                                             (line   16)
* tag_bind() (tkinter.ttk.Treeview metodo): ttk Treeview.    (line  293)
* tag_configure() (tkinter.ttk.Treeview metodo): ttk Treeview.
                                                             (line  299)
* tag_has() (tkinter.ttk.Treeview metodo): ttk Treeview.     (line  309)
* tagName (xml.dom.Element attributo):   Element Objects<2>. (line    9)
* tail (xml.etree.ElementTree.Element attributo): Element Objects.
                                                             (line   21)
* take_snapshot() (nel modulo tracemalloc): Functions<10>.   (line  110)
* takewhile() (nel modulo itertools):    Itertool Functions. (line  569)
* tan() (nel modulo cmath):              Trigonometric functions<2>.
                                                             (line   31)
* tan() (nel modulo math):               Trigonometric functions.
                                                             (line   39)
* tanh() (nel modulo cmath):             Hyperbolic functions<2>.
                                                             (line   31)
* tanh() (nel modulo math):              Hyperbolic functions.
                                                             (line   29)
* tar_filter() (nel modulo tarfile):     Default named filters.
                                                             (line   15)
* TarError:                              tarfile — Read and write tar archive files.
                                                             (line  246)
* TarFile (classe in tarfile):           TarFile Objects.    (line   22)
* tarfile command line option; -c:       Command-line options<3>.
                                                             (line   11)
* tarfile command line option; -create:  Command-line options<3>.
                                                             (line   11)
* tarfile command line option; -e:       Command-line options<3>.
                                                             (line   16)
* tarfile command line option; -extract: Command-line options<3>.
                                                             (line   16)
* tarfile command line option; -filter:  Command-line options<3>.
                                                             (line   31)
* tarfile command line option; -l:       Command-line options<3>.
                                                             (line    6)
* tarfile command line option; -list:    Command-line options<3>.
                                                             (line    6)
* tarfile command line option; -t:       Command-line options<3>.
                                                             (line   22)
* tarfile command line option; -test:    Command-line options<3>.
                                                             (line   22)
* tarfile command line option; -v:       Command-line options<3>.
                                                             (line   27)
* tarfile command line option; -verbose: Command-line options<3>.
                                                             (line   27)
* target:                                Assignment statements.
                                                             (line   27)
* target (xml.dom.ProcessingInstruction attributo): ProcessingInstruction Objects.
                                                             (line    9)
* target_length (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line  105)
* target;list:                           Assignment statements.
                                                             (line   27)
* target;list <1>:                       The for statement.  (line    6)
* target;list;assignment:                Assignment statements.
                                                             (line   35)
* TarInfo (classe in tarfile):           TarInfo Objects.    (line   33)
* tarinfo (tarfile.FilterError attributo): tarfile — Read and write tar archive files.
                                                             (line  280)
* Task (classe in asyncio):              Task Object.        (line    6)
* task_done() (asyncio.Queue metodo):    Queue.              (line  118)
* task_done() (multiprocessing.JoinableQueue metodo): Pipes and Queues.
                                                             (line  266)
* task_done() (queue.Queue metodo):      Queue Objects.      (line   73)
* TaskGroup (classe in asyncio):         Task Groups.        (line    9)
* tau (nel modulo cmath):                Constants<3>.       (line   14)
* tau (nel modulo math):                 Constants<2>.       (line   14)
* tb_frame (traceback attribute):        Traceback objects.  (line   31)
* tb_frame (traceback attributo):        Traceback objects.  (line   33)
* tb_lasti (traceback attribute):        Traceback objects.  (line   31)
* tb_lasti (traceback attributo):        Traceback objects.  (line   44)
* tb_lineno (traceback attribute):       Traceback objects.  (line   31)
* tb_lineno (traceback attributo):       Traceback objects.  (line   41)
* tb_locals (unittest.TestResult attributo): Loading and running tests.
                                                             (line  313)
* tb_next (traceback attribute):         Traceback objects.  (line   52)
* tb_next (traceback attributo):         Traceback objects.  (line   52)
* tbreak (pdb command):                  Debugger commands.  (line  130)
* tcdrain() (nel modulo termios):        termios — POSIX style tty control.
                                                             (line   65)
* tcflow() (nel modulo termios):         termios — POSIX style tty control.
                                                             (line   76)
* tcflush() (nel modulo termios):        termios — POSIX style tty control.
                                                             (line   70)
* tcgetattr() (nel modulo termios):      termios — POSIX style tty control.
                                                             (line   28)
* tcgetpgrp() (nel modulo os):           File Descriptor Operations.
                                                             (line  936)
* tcgetwinsize() (nel modulo termios):   termios — POSIX style tty control.
                                                             (line   83)
* Tcl() (nel modulo tkinter):            Tkinter Modules.    (line   94)
* TCPServer (classe in socketserver):    socketserver — A framework for network servers.
                                                             (line   20)
* TCSADRAIN (nel modulo termios):        termios — POSIX style tty control.
                                                             (line   50)
* TCSAFLUSH (nel modulo termios):        termios — POSIX style tty control.
                                                             (line   54)
* TCSANOW (nel modulo termios):          termios — POSIX style tty control.
                                                             (line   46)
* tcsendbreak() (nel modulo termios):    termios — POSIX style tty control.
                                                             (line   59)
* tcsetattr() (nel modulo termios):      termios — POSIX style tty control.
                                                             (line   39)
* tcsetpgrp() (nel modulo os):           File Descriptor Operations.
                                                             (line  943)
* tcsetwinsize() (nel modulo termios):   termios — POSIX style tty control.
                                                             (line   91)
* tearDown() (unittest.TestCase metodo): Test cases.         (line   41)
* tearDownClass() (unittest.TestCase metodo): Test cases.    (line   69)
* tearDownModule() (nel modulo unittest): setUpModule and tearDownModule.
                                                             (line    6)
* tee() (nel modulo itertools):          Itertool Functions. (line  588)
* teleport() (nel modulo turtle):        Turtle motion.      (line  104)
* tell() (io.IOBase metodo):             I/O Base Classes.   (line  135)
* tell() (io.TextIOBase metodo):         Text I/O<2>.        (line   88)
* tell() (io.TextIOWrapper metodo):      Text I/O<2>.        (line  238)
* tell() (mmap.mmap metodo):             mmap — Memory-mapped file support.
                                                             (line  319)
* tell() (sqlite3.Blob metodo):          Blob objects.       (line   59)
* tell() (wave.Wave_read metodo):        Wave_read Objects.  (line   87)
* tell() (wave.Wave_write metodo):       Wave_write Objects. (line   70)
* TEMP:                                  tempfile — Generate temporary files and directories.
                                                             (line  333)
* temp_cwd() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line  138)
* temp_dir() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line  153)
* temp_umask() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line  163)
* tempdir (nel modulo tempfile):         tempfile — Generate temporary files and directories.
                                                             (line  380)
* Template (classe in string.templatelib): Types.            (line    6)
* Template (classe in string):           Template strings $-strings.
                                                             (line   45)
* template (string.Template attributo):  Template strings $-strings.
                                                             (line   95)
* TemplateStr (classe in ast):           Literals<3>.        (line   66)
* temporary (bdb.Breakpoint attributo):  bdb — Debugger framework.
                                                             (line   91)
* temporary;file:                        tempfile — Generate temporary files and directories.
                                                             (line    8)
* temporary;file name:                   tempfile — Generate temporary files and directories.
                                                             (line    8)
* TemporaryDirectory (classe in tempfile): tempfile — Generate temporary files and directories.
                                                             (line  184)
* TemporaryFile() (nel modulo tempfile): tempfile — Generate temporary files and directories.
                                                             (line   28)
* teredo (ipaddress.IPv6Address attributo): Address objects. (line  324)
* TERM:                                  Functions<5>.       (line  501)
* TERM <1>:                              Functions<5>.       (line  528)
* termattrs() (nel modulo curses):       Functions<5>.       (line  520)
* terminal_size (classe in os):          Querying the size of a terminal.
                                                             (line   25)
* terminate_workers() (concurrent.futures.ProcessPoolExecutor metodo): ProcessPoolExecutor.
                                                             (line   98)
* terminate() (asyncio.subprocess.Process metodo): Interacting with Subprocesses.
                                                             (line   96)
* terminate() (asyncio.SubprocessTransport metodo): Subprocess Transports.
                                                             (line   49)
* terminate() (multiprocessing.pool.Pool metodo): Process Pools.
                                                             (line  182)
* terminate() (multiprocessing.Process metodo): Process and exceptions.
                                                             (line  226)
* terminate() (subprocess.Popen metodo): Popen Objects.      (line   94)
* termination model:                     Exceptions.         (line   20)
* terminator (logging.StreamHandler attributo): StreamHandler.
                                                             (line   47)
* termname() (nel modulo curses):        Functions<5>.       (line  526)
* ternary;operator:                      Conditional expressions.
                                                             (line    6)
* ternaryfunc (C type):                  Slot Type typedefs. (line  120)
* test (doctest.DocTestFailure attributo): Debugging.        (line  195)
* test (doctest.UnexpectedException attributo): Debugging.   (line  216)
* TEST_DATA_DIR (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  154)
* TEST_HOME_DIR (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  150)
* TEST_HTTP_URL (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  188)
* TEST_SUPPORT_DIR (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  145)
* TestCase (classe in unittest):         Test cases.         (line    6)
* TestFailed:                            test support — Utilities for the Python test suite.
                                                             (line   16)
* testfile() (nel modulo doctest):       Basic API.          (line   12)
* TESTFN (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   19)
* TESTFN_NONASCII (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   25)
* TESTFN_UNDECODABLE (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   39)
* TESTFN_UNENCODABLE (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   33)
* TESTFN_UNICODE (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line   45)
* TestLoader (classe in unittest):       Loading and running tests.
                                                             (line    6)
* testMethodPrefix (unittest.TestLoader attributo): Loading and running tests.
                                                             (line  189)
* testmod() (nel modulo doctest):        Basic API.          (line   90)
* testNamePatterns (unittest.TestLoader attributo): Loading and running tests.
                                                             (line  211)
* TestResult (classe in unittest):       Loading and running tests.
                                                             (line  228)
* TestResults (classe in doctest):       TestResults objects.
                                                             (line    6)
* testsource() (nel modulo doctest):     Debugging.          (line  106)
* testsRun (unittest.TestResult attributo): Loading and running tests.
                                                             (line  291)
* TestSuite (classe in unittest):        Grouping tests.     (line    6)
* testzip() (zipfile.ZipFile metodo):    ZipFile objects.    (line  269)
* Text (classe in typing):               Aliases to other concrete types.
                                                             (line   21)
* text (ctypes.COMError attributo):      Exceptions<9>.      (line   19)
* text (SyntaxError attributo):          Concrete exceptions.
                                                             (line  339)
* text (traceback.TracebackException attributo): TracebackException Objects.
                                                             (line  106)
* text (xml.etree.ElementTree.Element attributo): Element Objects.
                                                             (line   21)
* text encoding:                         Glossary.           (line 1687)
* text file:                             Glossary.           (line 1700)
* text_encoding() (nel modulo io):       High-level Module Interface.
                                                             (line   38)
* text_factory (sqlite3.Connection attributo): Connection objects.
                                                             (line  808)
* Textbox (classe in curses.textpad):    Textbox objects.    (line    8)
* TextCalendar (classe in calendar):     calendar — General calendar-related functions.
                                                             (line  150)
* textdomain() (nel modulo gettext):     GNU gettext API.    (line   26)
* textdomain() (nel modulo locale):      Access to message catalogs.
                                                             (line   12)
* textinput() (nel modulo turtle):       Input methods.      (line    6)
* TextIO (classe in typing):             ABCs and Protocols for working with I/O.
                                                             (line    6)
* TextIOBase (classe in io):             Text I/O<2>.        (line    6)
* TextIOWrapper (classe in io):          Text I/O<2>.        (line   99)
* TextTestResult (classe in unittest):   Loading and running tests.
                                                             (line  448)
* TextTestRunner (classe in unittest):   Loading and running tests.
                                                             (line  466)
* TextWrapper (classe in textwrap):      textwrap — Text wrapping and filling.
                                                             (line  146)
* TFD_CLOEXEC (nel modulo os):           Timer File Descriptors.
                                                             (line  203)
* TFD_NONBLOCK (nel modulo os):          Timer File Descriptors.
                                                             (line  192)
* TFD_TIMER_ABSTIME (nel modulo os):     Timer File Descriptors.
                                                             (line  213)
* TFD_TIMER_CANCEL_ON_SET (nel modulo os): Timer File Descriptors.
                                                             (line  224)
* theme_create() (tkinter.ttk.Style metodo): Ttk Styling.    (line  260)
* theme_names() (tkinter.ttk.Style metodo): Ttk Styling.     (line  308)
* theme_settings() (tkinter.ttk.Style metodo): Ttk Styling.  (line  270)
* theme_use() (tkinter.ttk.Style metodo): Ttk Styling.       (line  312)
* THOUSEP (nel modulo locale):           locale — Internationalization services.
                                                             (line  284)
* Thread (classe in threading):          Thread objects.     (line   57)
* thread state:                          Glossary.           (line 1712)
* thread_info (nel modulo sys):          sys — System-specific parameters and functions.
                                                             (line 2095)
* thread_inherit_context (sys.flags attributo): sys — System-specific parameters and functions.
                                                             (line  597)
* thread_time_ns() (nel modulo time):    Functions<4>.       (line  632)
* thread_time() (nel modulo time):       Functions<4>.       (line  614)
* thread_unsafe() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  560)
* thread-safe:                           Glossary.           (line 1735)
* thread() (imaplib.IMAP4 metodo):       IMAP4 Objects.      (line  423)
* threading_cleanup() (nel modulo test.support.threading_helper): test support threading_helper — Utilities for threading tests.
                                                             (line   31)
* threading_setup() (nel modulo test.support.threading_helper): test support threading_helper — Utilities for threading tests.
                                                             (line   37)
* ThreadingHTTPServer (classe in http.server): http server — HTTP servers.
                                                             (line   37)
* ThreadingHTTPSServer (classe in http.server): http server — HTTP servers.
                                                             (line   82)
* ThreadingMixIn (classe in socketserver): Server Creation Notes.
                                                             (line   27)
* ThreadingMock (classe in unittest.mock): The Mock Class.   (line  956)
* ThreadingTCPServer (classe in socketserver): Server Creation Notes.
                                                             (line   74)
* ThreadingUDPServer (classe in socketserver): Server Creation Notes.
                                                             (line   74)
* ThreadingUnixDatagramServer (classe in socketserver): Server Creation Notes.
                                                             (line   74)
* ThreadingUnixStreamServer (classe in socketserver): Server Creation Notes.
                                                             (line   74)
* ThreadPool (classe in multiprocessing.pool): The multiprocessing dummy module.
                                                             (line   16)
* ThreadPoolExecutor (classe in concurrent.futures): ThreadPoolExecutor.
                                                             (line   39)
* threads;POSIX:                         _thread — Low-level threading API.
                                                             (line   16)
* threadsafety (nel modulo sqlite3):     Module constants.   (line   88)
* throw() (coroutine metodo):            Coroutine Objects.  (line   33)
* throw() (generator metodo):            Generator-iterator methods.
                                                             (line   38)
* THURSDAY (nel modulo calendar):        calendar — General calendar-related functions.
                                                             (line  447)
* ticket_lifetime_hint (ssl.SSLSession attributo): SSL session.
                                                             (line   18)
* tigetflag() (nel modulo curses):       Functions<5>.       (line  531)
* tigetnum() (nel modulo curses):        Functions<5>.       (line  538)
* tigetstr() (nel modulo curses):        Functions<5>.       (line  545)
* TILDE (nel modulo token):              token — Constants used with Python parse trees.
                                                             (line  284)
* tilt() (nel modulo turtle):            Appearance.         (line  101)
* tiltangle() (nel modulo turtle):       Appearance.         (line  117)
* time (classe in datetime):             time Objects.       (line   10)
* time (ssl.SSLSession attributo):       SSL session.        (line   14)
* time (uuid.UUID attributo):            uuid — UUID objects according to RFC 9562.
                                                             (line  131)
* time_hi_version (uuid.UUID attributo): uuid — UUID objects according to RFC 9562.
                                                             (line  115)
* time_low (uuid.UUID attributo):        uuid — UUID objects according to RFC 9562.
                                                             (line  107)
* time_mid (uuid.UUID attributo):        uuid — UUID objects according to RFC 9562.
                                                             (line  111)
* time_ns() (nel modulo time):           Functions<4>.       (line  607)
* time() (asyncio.loop metodo):          Scheduling delayed callbacks.
                                                             (line   64)
* time() (datetime.datetime metodo):     datetime Objects.   (line  446)
* time() (nel modulo time):              Functions<4>.       (line  571)
* Time2Internaldate() (nel modulo imaplib): imaplib — IMAP4 protocol client.
                                                             (line  129)
* timedelta (classe in datetime):        timedelta Objects.  (line    9)
* TimedRotatingFileHandler (classe in logging.handlers): TimedRotatingFileHandler.
                                                             (line   10)
* timegm() (nel modulo calendar):        calendar — General calendar-related functions.
                                                             (line  418)
* timeit command line option; -h:        Command-Line Interface<3>.
                                                             (line   44)
* timeit command line option; -help:     Command-Line Interface<3>.
                                                             (line   44)
* timeit command line option; -n:        Command-Line Interface<3>.
                                                             (line   13)
* timeit command line option; -number:   Command-Line Interface<3>.
                                                             (line   13)
* timeit command line option; -p:        Command-Line Interface<3>.
                                                             (line   25)
* timeit command line option; -process:  Command-Line Interface<3>.
                                                             (line   25)
* timeit command line option; -r:        Command-Line Interface<3>.
                                                             (line   17)
* timeit command line option; -repeat:   Command-Line Interface<3>.
                                                             (line   17)
* timeit command line option; -s:        Command-Line Interface<3>.
                                                             (line   21)
* timeit command line option; -setup:    Command-Line Interface<3>.
                                                             (line   21)
* timeit command line option; -u:        Command-Line Interface<3>.
                                                             (line   33)
* timeit command line option; -unit:     Command-Line Interface<3>.
                                                             (line   33)
* timeit command line option; -v:        Command-Line Interface<3>.
                                                             (line   40)
* timeit command line option; -verbose:  Command-Line Interface<3>.
                                                             (line   40)
* timeit() (nel modulo timeit):          Python Interface.   (line    8)
* timeit() (timeit.Timer metodo):        Python Interface.   (line   74)
* timeout:                               Exceptions<17>.     (line   40)
* Timeout (classe in asyncio):           Timeouts.           (line   50)
* timeout (socketserver.BaseServer attributo): Server Objects<2>.
                                                             (line  118)
* timeout (ssl.SSLSession attributo):    SSL session.        (line   16)
* timeout (subprocess.TimeoutExpired attributo): Using the subprocess Module.
                                                             (line  178)
* timeout_at() (nel modulo asyncio):     Timeouts.           (line   98)
* TIMEOUT_MAX (nel modulo _thread):      _thread — Low-level threading API.
                                                             (line  135)
* TIMEOUT_MAX (nel modulo threading):    Reference<2>.       (line  184)
* timeout() (curses.window metodo):      Window Objects.     (line  570)
* timeout() (nel modulo asyncio):        Timeouts.           (line    6)
* TimeoutError:                          OS exceptions.      (line  112)
* TimeoutError <1>:                      Process and exceptions.
                                                             (line  298)
* TimeoutError <2>:                      Exception classes.  (line   10)
* TimeoutError <3>:                      Exceptions<15>.     (line   10)
* TimeoutExpired:                        Using the subprocess Module.
                                                             (line  169)
* Timer (classe in threading):           Timer objects.      (line   25)
* Timer (classe in timeit):              Python Interface.   (line   43)
* timerfd_create() (nel modulo os):      Timer File Descriptors.
                                                             (line   11)
* timerfd_gettime_ns() (nel modulo os):  Timer File Descriptors.
                                                             (line  183)
* timerfd_gettime() (nel modulo os):     Timer File Descriptors.
                                                             (line  163)
* timerfd_settime_ns() (nel modulo os):  Timer File Descriptors.
                                                             (line  152)
* timerfd_settime() (nel modulo os):     Timer File Descriptors.
                                                             (line   84)
* TimerHandle (classe in asyncio):       Callback Handles.   (line   29)
* times() (nel modulo os):               Process Management. (line  807)
* TIMESTAMP (py_compile.PycInvalidationMode attributo): py_compile — Compile Python source files.
                                                             (line  102)
* timestamp() (datetime.datetime metodo): datetime Objects.  (line  600)
* timetuple() (datetime.date metodo):    date Objects.       (line  240)
* timetuple() (datetime.datetime metodo): datetime Objects.  (line  554)
* timetz() (datetime.datetime metodo):   datetime Objects.   (line  455)
* timezone (classe in datetime):         timezone Objects.   (line   14)
* timezone (nel modulo time):            Timezone Constants. (line   17)
* title() (bytearray metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  713)
* title() (bytes metodo):                Operazioni su Bytes e Bytearray.
                                                             (line  713)
* title() (nel modulo turtle):           Methods specific to Screen not inherited from TurtleScreen.
                                                             (line   68)
* title() (str metodo):                  Metodi per le Stringhe.
                                                             (line  828)
* Tk:                                    Graphical user interfaces with Tk.
                                                             (line    6)
* Tk (classe in tkinter):                Tkinter Modules.    (line   14)
* tk (tkinter.Tk attributo):             Tkinter Modules.    (line   70)
* Tk Option Data Types:                  Tk Option Data Types.
                                                             (line    6)
* Tkinter:                               Graphical user interfaces with Tk.
                                                             (line    6)
* TLS:                                   ssl — TLS/SSL wrapper for socket objects.
                                                             (line    8)
* TLSv1 (ssl.TLSVersion attributo):      Constants<9>.       (line  579)
* TLSv1_1 (ssl.TLSVersion attributo):    Constants<9>.       (line  581)
* TLSv1_2 (ssl.TLSVersion attributo):    Constants<9>.       (line  583)
* TLSv1_3 (ssl.TLSVersion attributo):    Constants<9>.       (line  585)
* TLSVersion (classe in ssl):            Constants<9>.       (line  561)
* tm_gmtoff (time.struct_time attributo): Functions<4>.      (line  556)
* tm_hour (time.struct_time attributo):  Functions<4>.       (line  533)
* tm_isdst (time.struct_time attributo): Functions<4>.       (line  550)
* tm_mday (time.struct_time attributo):  Functions<4>.       (line  530)
* tm_min (time.struct_time attributo):   Functions<4>.       (line  536)
* tm_mon (time.struct_time attributo):   Functions<4>.       (line  527)
* tm_sec (time.struct_time attributo):   Functions<4>.       (line  539)
* tm_wday (time.struct_time attributo):  Functions<4>.       (line  544)
* tm_yday (time.struct_time attributo):  Functions<4>.       (line  547)
* tm_year (time.struct_time attributo):  Functions<4>.       (line  524)
* tm_zone (time.struct_time attributo):  Functions<4>.       (line  553)
* TMP:                                   tempfile — Generate temporary files and directories.
                                                             (line  335)
* TMPDIR:                                Library<22>.        (line   79)
* TMPDIR <1>:                            Tests<27>.          (line   68)
* TMPDIR <2>:                            tempfile — Generate temporary files and directories.
                                                             (line  331)
* TO_BOOL (opcode):                      Python Bytecode Instructions.
                                                             (line  240)
* to_bytes() (int metodo):               Metodi Aggiuntivi sui Tipi Integer.
                                                             (line   57)
* to_eng_string() (decimal.Context metodo): Context objects. (line  546)
* to_eng_string() (decimal.Decimal metodo): Decimal objects. (line  590)
* to_integral_exact() (decimal.Context metodo): Context objects.
                                                             (line  556)
* to_integral_exact() (decimal.Decimal metodo): Decimal objects.
                                                             (line  609)
* to_integral_value() (decimal.Decimal metodo): Decimal objects.
                                                             (line  617)
* to_integral() (decimal.Decimal metodo): Decimal objects.   (line  603)
* to_sci_string() (decimal.Context metodo): Context objects. (line  560)
* to_thread() (nel modulo asyncio):      Running in Threads. (line    6)
* ToASCII() (nel modulo encodings.idna): encodings idna — Internationalized Domain Names in Applications.
                                                             (line   55)
* tobuf() (tarfile.TarInfo metodo):      TarInfo Objects.    (line   49)
* tobytes() (array.array metodo):        array — Efficient arrays of numeric values.
                                                             (line  235)
* tobytes() (memoryview metodo):         Memory Views.       (line  174)
* today() (datetime.date metodo della classe): date Objects. (line   29)
* today() (datetime.datetime metodo della classe): datetime Objects.
                                                             (line   47)
* tofile() (array.array metodo):         array — Efficient arrays of numeric values.
                                                             (line  244)
* tok_name (nel modulo token):           token — Constants used with Python parse trees.
                                                             (line   25)
* token:                                 Lexical analysis.   (line    6)
* token <1>:                             Glossary.           (line 1748)
* Token (classe in contextvars):         Context Variables.  (line  103)
* token (shlex.shlex attributo):         shlex Objects.      (line  173)
* token_bytes() (nel modulo secrets):    Generating tokens.  (line   10)
* token_hex() (nel modulo secrets):      Generating tokens.  (line   19)
* token_urlsafe() (nel modulo secrets):  Generating tokens.  (line   28)
* TokenError:                            Tokenizing Input.   (line  106)
* tokenize command line option; -e:      Command-Line Usage<4>.
                                                             (line   19)
* tokenize command line option; -exact:  Command-Line Usage<4>.
                                                             (line   19)
* tokenize command line option; -h:      Command-Line Usage<4>.
                                                             (line   15)
* tokenize command line option; -help:   Command-Line Usage<4>.
                                                             (line   15)
* tokenize() (nel modulo tokenize):      Tokenizing Input.   (line    8)
* tolist() (array.array metodo):         array — Efficient arrays of numeric values.
                                                             (line  249)
* tolist() (memoryview metodo):          Memory Views.       (line  219)
* TOMLDecodeError:                       tomllib — Parse TOML files.
                                                             (line   60)
* toordinal() (datetime.date metodo):    date Objects.       (line  255)
* toordinal() (datetime.datetime metodo): datetime Objects.  (line  595)
* top_panel() (nel modulo curses.panel): Functions<6>.       (line   19)
* top() (curses.panel.Panel metodo):     Panel Objects.      (line   53)
* top() (poplib.POP3 metodo):            POP3 Objects.       (line   87)
* TopologicalSorter (classe in graphlib): graphlib — Functionality to operate with graph-like structures.
                                                             (line   10)
* toprettyxml() (xml.dom.minidom.Node metodo): DOM Objects.  (line   72)
* toreadonly() (memoryview metodo):      Memory Views.       (line  236)
* tostring() (nel modulo xml.etree.ElementTree): Functions<8>.
                                                             (line  223)
* tostringlist() (nel modulo xml.etree.ElementTree): Functions<8>.
                                                             (line  246)
* total_changes (sqlite3.Connection attributo): Connection objects.
                                                             (line  818)
* total_nframe (tracemalloc.Traceback attributo): Traceback. (line   28)
* total_ordering() (nel modulo functools): functools — Higher-order functions and operations on callable objects.
                                                             (line  272)
* total_seconds() (datetime.timedelta metodo): timedelta Objects.
                                                             (line  246)
* total() (collections.Counter metodo):  Counter objects.    (line  104)
* touch() (pathlib.Path metodo):         Creating files and directories.
                                                             (line    6)
* touchline() (curses.window metodo):    Window Objects.     (line  580)
* touchwin() (curses.window metodo):     Window Objects.     (line  587)
* tounicode() (array.array metodo):      array — Efficient arrays of numeric values.
                                                             (line  253)
* ToUnicode() (nel modulo encodings.idna): encodings idna — Internationalized Domain Names in Applications.
                                                             (line   60)
* towards() (nel modulo turtle):         Tell Turtle’s state.
                                                             (line   15)
* toxml() (xml.dom.minidom.Node metodo): DOM Objects.        (line   52)
* tparm() (nel modulo curses):           Functions<5>.       (line  552)
* Trace (classe in trace):               Programmatic Interface.
                                                             (line    6)
* Trace (classe in tracemalloc):         Trace.              (line    6)
* trace command line option; -c:         Main options.       (line   12)
* trace command line option; -C:         Modifiers.          (line   11)
* trace command line option; -count:     Main options.       (line   12)
* trace command line option; -coverdir:  Modifiers.          (line   11)
* trace command line option; -f:         Modifiers.          (line    6)
* trace command line option; -file:      Modifiers.          (line    6)
* trace command line option; -g:         Modifiers.          (line   33)
* trace command line option; -help:      Command-Line Usage<2>.
                                                             (line   15)
* trace command line option; -ignore-dir: Filters.           (line   14)
* trace command line option; -ignore-module: Filters.        (line    8)
* trace command line option; -l:         Main options.       (line   23)
* trace command line option; -listfuncs: Main options.       (line   23)
* trace command line option; -m:         Modifiers.          (line   17)
* trace command line option; -missing:   Modifiers.          (line   17)
* trace command line option; -no-report: Modifiers.          (line   27)
* trace command line option; -r:         Main options.       (line   27)
* trace command line option; -R:         Modifiers.          (line   27)
* trace command line option; -report:    Main options.       (line   27)
* trace command line option; -s:         Modifiers.          (line   22)
* trace command line option; -summary:   Modifiers.          (line   22)
* trace command line option; -t:         Main options.       (line   19)
* trace command line option; -T:         Main options.       (line   33)
* trace command line option; -timing:    Modifiers.          (line   33)
* trace command line option; -trace:     Main options.       (line   19)
* trace command line option; -trackcalls: Main options.      (line   33)
* trace command line option; -version:   Command-Line Usage<2>.
                                                             (line   19)
* trace function:                        Reference<2>.       (line  116)
* trace function <1>:                    Reference<2>.       (line  132)
* trace function <2>:                    sys — System-specific parameters and functions.
                                                             (line  979)
* trace function <3>:                    sys — System-specific parameters and functions.
                                                             (line 1743)
* trace_dispatch() (bdb.Bdb metodo):     bdb — Debugger framework.
                                                             (line  191)
* trace() (nel modulo inspect):          The interpreter stack.
                                                             (line  186)
* Traceback (classe in inspect):         The interpreter stack.
                                                             (line   56)
* Traceback (classe in tracemalloc):     Traceback.          (line    6)
* traceback (tracemalloc.Statistic attributo): Statistic.    (line   23)
* traceback (tracemalloc.StatisticDiff attributo): StatisticDiff.
                                                             (line   38)
* traceback (tracemalloc.Trace attributo): Trace.            (line   28)
* traceback_limit (tracemalloc.Snapshot attributo): Snapshot.
                                                             (line   83)
* traceback_limit (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  223)
* TracebackException (classe in traceback): TracebackException Objects.
                                                             (line   15)
* tracebacklimit (nel modulo sys):       sys — System-specific parameters and functions.
                                                             (line 2131)
* TracebackType (classe in types):       Standard Interpreter Types.
                                                             (line  189)
* tracer() (nel modulo turtle):          Animation control.  (line   36)
* traces (tracemalloc.Snapshot attributo): Snapshot.         (line   89)
* trailing;comma:                        Expression lists.   (line   29)
* train_dict() (nel modulo compression.zstd): Zstandard dictionaries.
                                                             (line    6)
* transfercmd() (ftplib.FTP metodo):     FTP objects.        (line  258)
* transient_internet() (nel modulo test.support.socket_helper): test support socket_helper — Utilities for socket tests.
                                                             (line   64)
* translate() (bytearray metodo):        Operazioni su Bytes e Bytearray.
                                                             (line  274)
* translate() (bytes metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  274)
* translate() (nel modulo fnmatch):      fnmatch — Unix filename pattern matching.
                                                             (line   91)
* translate() (nel modulo glob):         glob — Unix style pathname pattern expansion.
                                                             (line  114)
* translate() (str metodo):              Metodi per le Stringhe.
                                                             (line  865)
* translation() (nel modulo gettext):    Class-based API.    (line   44)
* transport (asyncio.StreamWriter attributo): StreamWriter.  (line   60)
* Transport (classe in asyncio):         Transports Hierarchy.
                                                             (line   29)
* Transport Layer Security:              ssl — TLS/SSL wrapper for socket objects.
                                                             (line    8)
* traps (decimal.Context attributo):     Context objects.    (line  142)
* Traversable (classe in importlib.resources.abc): importlib resources abc – Abstract base classes for resources.
                                                             (line   89)
* TraversableResources (classe in importlib.resources.abc): importlib resources abc – Abstract base classes for resources.
                                                             (line  161)
* traverseproc (C type):                 Supporting Cyclic Garbage Collection.
                                                             (line  234)
* TreeBuilder (classe in xml.etree.ElementTree): TreeBuilder Objects.
                                                             (line    6)
* Treeview (classe in tkinter.ttk):      ttk Treeview.       (line    6)
* triangular() (nel modulo random):      Real-valued distributions.
                                                             (line   25)
* tries (doctest.DocTestRunner attributo): DocTestRunner objects.
                                                             (line  135)
* triple-quoted string:                  String and Bytes literals.
                                                             (line   33)
* triple-quoted string <1>:              Glossary.           (line 1758)
* True:                                  numbers Integral.   (line   27)
* True (variabile built-in):             Built-in Constants. (line   13)
* truediv() (nel modulo operator):       operator — Standard operators as functions.
                                                             (line  174)
* trunc() (nel modulo math):             Tipi Numerici — int float complex.
                                                             (line  117)
* trunc() (nel modulo math) <1>:         Floating point arithmetic.
                                                             (line   87)
* truncate() (io.IOBase metodo):         I/O Base Classes.   (line  139)
* truncate() (nel modulo os):            Files and Directories.
                                                             (line 1576)
* truth() (nel modulo operator):         operator — Standard operators as functions.
                                                             (line   57)
* Try (classe in ast):                   Control flow.       (line  130)
* TryStar (classe in ast):               Control flow.       (line  173)
* TSTRING_END (nel modulo token):        token — Constants used with Python parse trees.
                                                             (line  147)
* TSTRING_MIDDLE (nel modulo token):     token — Constants used with Python parse trees.
                                                             (line  134)
* TSTRING_START (nel modulo token):      token — Constants used with Python parse trees.
                                                             (line  123)
* ttk:                                   tkinter ttk — Tk themed widgets.
                                                             (line    8)
* tty;I/O control:                       termios — POSIX style tty control.
                                                             (line    6)
* ttyname() (nel modulo os):             File Descriptor Operations.
                                                             (line  951)
* TUESDAY (nel modulo calendar):         calendar — General calendar-related functions.
                                                             (line  447)
* tuple (classe built-in):               Tuple.              (line   13)
* Tuple (classe in ast):                 Literals<3>.        (line  129)
* Tuple (nel modulo typing):             Aliases to built-in types.
                                                             (line   50)
* Turtle (classe in turtle):             Public classes.     (line   16)
* turtles() (nel modulo turtle):         Settings and special methods.
                                                             (line  110)
* TurtleScreen (classe in turtle):       Public classes.     (line   22)
* turtlesize() (nel modulo turtle):      Appearance.         (line   52)
* type:                                  The standard type hierarchy.
                                                             (line    6)
* type <1>:                              Glossary.           (line 1768)
* type (classe built-in):                Funzioni Incorporate.
                                                             (line 2115)
* Type (classe in typing):               Aliases to built-in types.
                                                             (line   61)
* type (ctypes.CField attributo):        Structured data types.
                                                             (line  252)
* type (optparse.Option attributo):      Option attributes.  (line   27)
* type (socket.socket attributo):        Socket Objects.     (line  625)
* type (tarfile.TarInfo attributo):      TarInfo Objects.    (line   86)
* type (urllib.request.Request attributo): Request Objects.  (line   21)
* type alias:                            Glossary.           (line 1775)
* type hint:                             Glossary.           (line 1797)
* type of an object:                     Objects values and types.
                                                             (line   10)
* type parameters:                       Type parameter lists.
                                                             (line   11)
* TYPE_ALIAS (symtable.SymbolTableType attributo): Examining Symbol Tables.
                                                             (line   31)
* type_check_only() (nel modulo typing): Functions and decorators.
                                                             (line  411)
* TYPE_CHECKER (optparse.Option attributo): Adding new types.
                                                             (line   16)
* TYPE_CHECKING (nel modulo typing):     Constant.           (line    6)
* type_comment (ast.arg attributo):      Function and class definitions.
                                                             (line   74)
* type_comment (ast.Assign attributo):   Statements.         (line   15)
* type_comment (ast.For attributo):      Control flow.       (line   54)
* type_comment (ast.FunctionDef attributo): Function and class definitions.
                                                             (line   25)
* type_comment (ast.With attributo):     Control flow.       (line  236)
* TYPE_COMMENT (nel modulo token):       token — Constants used with Python parse trees.
                                                             (line  181)
* TYPE_IGNORE (nel modulo token):        token — Constants used with Python parse trees.
                                                             (line  174)
* TYPE_PARAMETERS (symtable.SymbolTableType attributo): Examining Symbol Tables.
                                                             (line   35)
* type_repr() (nel modulo annotationlib): Functions<11>.     (line  227)
* TYPE_VARIABLE (symtable.SymbolTableType attributo): Examining Symbol Tables.
                                                             (line   40)
* type;hierarchy:                        The standard type hierarchy.
                                                             (line    6)
* typeahead() (nel modulo curses):       Functions<5>.       (line  560)
* TypeAlias (classe in ast):             Statements.         (line  163)
* TypeAlias (nel modulo typing):         Special types.      (line  198)
* TypeAliasType (classe in typing):      Building generic types and type aliases.
                                                             (line  552)
* typecode (array.array attributo):      array — Efficient arrays of numeric values.
                                                             (line  113)
* typecodes (nel modulo array):          array — Efficient arrays of numeric values.
                                                             (line   82)
* TYPED_ACTIONS (optparse.Option attributo): Adding new actions.
                                                             (line   39)
* typed_subpart_iterator() (nel modulo email.iterators): email iterators Iterators.
                                                             (line   26)
* TypedDict (classe in typing):          Other special directives.
                                                             (line  248)
* TypeError:                             Concrete exceptions.
                                                             (line  418)
* TypeGuard (nel modulo typing):         Special forms.      (line  534)
* TypeIgnore (classe in ast):            Type annotations.   (line    6)
* TypeIs (nel modulo typing):            Special forms.      (line  444)
* TYPES (optparse.Option attributo):     Adding new types.   (line   11)
* types_map (mimetypes.MimeTypes attributo): MimeTypes objects.
                                                             (line   39)
* types_map (nel modulo mimetypes):      mimetypes — Map filenames to MIME types.
                                                             (line  157)
* types_map_inv (mimetypes.MimeTypes attributo): MimeTypes objects.
                                                             (line   47)
* types, internal:                       Internal types.     (line    6)
* TypeVar (classe in ast):               Type parameters.    (line    9)
* TypeVar (classe in typing):            Building generic types and type aliases.
                                                             (line   54)
* TypeVarTuple (classe in ast):          Type parameters.    (line   68)
* TypeVarTuple (classe in typing):       Building generic types and type aliases.
                                                             (line  253)
* TZ:                                    Functions<4>.       (line  642)
* TZ <1>:                                Functions<4>.       (line  643)
* TZ <2>:                                Functions<4>.       (line  651)
* TZ <3>:                                Functions<4>.       (line  656)
* TZ <4>:                                Functions<4>.       (line  658)
* TZ <5>:                                Functions<4>.       (line  719)
* tzinfo (classe in datetime):           tzinfo Objects.     (line    6)
* tzinfo (datetime.datetime attributo):  datetime Objects.   (line  334)
* tzinfo (datetime.time attributo):      time Objects.       (line   66)
* tzname (nel modulo time):              Timezone Constants. (line   23)
* tzname() (datetime.datetime metodo):   datetime Objects.   (line  548)
* tzname() (datetime.time metodo):       time Objects.       (line  273)
* tzname() (datetime.timezone metodo):   timezone Objects.   (line   42)
* tzname() (datetime.tzinfo metodo):     tzinfo Objects.     (line  123)
* TZPATH (nel modulo zoneinfo):          Globals.            (line    6)
* tzset() (nel modulo time):             Functions<4>.       (line  639)
* U (nel modulo re):                     Flags.              (line  117)
* u';string literal:                     Triple-quoted strings.
                                                             (line   23)
* u";string literal:                     Triple-quoted strings.
                                                             (line   22)
* UAdd (classe in ast):                  Expressions<2>.     (line   27)
* ucd_3_2_0 (nel modulo unicodedata):    unicodedata — Unicode Database.
                                                             (line  183)
* udata (select.kevent attributo):       Kevent Objects.     (line  179)
* UDPServer (classe in socketserver):    socketserver — A framework for network servers.
                                                             (line   30)
* UF_APPEND (nel modulo stat):           stat — Interpreting stat results.
                                                             (line  353)
* UF_COMPRESSED (nel modulo stat):       stat — Interpreting stat results.
                                                             (line  365)
* UF_DATAVAULT (nel modulo stat):        stat — Interpreting stat results.
                                                             (line  375)
* UF_HIDDEN (nel modulo stat):           stat — Interpreting stat results.
                                                             (line  381)
* UF_IMMUTABLE (nel modulo stat):        stat — Interpreting stat results.
                                                             (line  349)
* UF_NODUMP (nel modulo stat):           stat — Interpreting stat results.
                                                             (line  345)
* UF_NOUNLINK (nel modulo stat):         stat — Interpreting stat results.
                                                             (line  361)
* UF_OPAQUE (nel modulo stat):           stat — Interpreting stat results.
                                                             (line  357)
* UF_SETTABLE (nel modulo stat):         stat — Interpreting stat results.
                                                             (line  339)
* UF_TRACKED (nel modulo stat):          stat — Interpreting stat results.
                                                             (line  369)
* UID (classe in plistlib):              plistlib — Generate and parse Apple plist files.
                                                             (line  141)
* uid (tarfile.TarInfo attributo):       TarInfo Objects.    (line  105)
* uid() (imaplib.IMAP4 metodo):          IMAP4 Objects.      (line  446)
* uidl() (poplib.POP3 metodo):           POP3 Objects.       (line   99)
* ULONG_MAX (C macro):                   Integer Objects.    (line  280)
* ulp() (nel modulo math):               Floating point manipulation functions.
                                                             (line  108)
* umask() (nel modulo os):               Process Parameters. (line  567)
* unalias (pdb command):                 Debugger commands.  (line  409)
* uname (tarfile.TarInfo attributo):     TarInfo Objects.    (line  121)
* uname() (nel modulo os):               Process Parameters. (line  574)
* uname() (nel modulo platform):         Cross platform.     (line  146)
* UNARY_INVERT (opcode):                 Python Bytecode Instructions.
                                                             (line  224)
* UNARY_NEGATIVE (opcode):               Python Bytecode Instructions.
                                                             (line  213)
* UNARY_NOT (opcode):                    Python Bytecode Instructions.
                                                             (line  217)
* unary;arithmetic;operation:            Unary arithmetic and bitwise operations.
                                                             (line    6)
* unary;bitwise;operation:               Unary arithmetic and bitwise operations.
                                                             (line    6)
* unaryfunc (C type):                    Slot Type typedefs. (line  106)
* UnaryOp (classe in ast):               Expressions<2>.     (line   22)
* unbinding;name:                        The del statement.  (line   15)
* UnboundLocalError:                     Resolution of names.
                                                             (line   16)
* UnboundLocalError <1>:                 Concrete exceptions.
                                                             (line  436)
* UNC paths;and os.makedirs():           Files and Directories.
                                                             (line  548)
* uncancel() (asyncio.Task metodo):      Task Object.        (line  271)
* UNCHECKED_HASH (py_compile.PycInvalidationMode attributo): py_compile — Compile Python source files.
                                                             (line  115)
* unconsumed_tail (zlib.Decompress attributo): zlib — Compression compatible with gzip.
                                                             (line  244)
* unctrl() (nel modulo curses.ascii):    curses ascii — Utilities for ASCII characters.
                                                             (line  229)
* unctrl() (nel modulo curses):          Functions<5>.       (line  572)
* Underflow (classe in decimal):         Signals.            (line   95)
* undisplay (pdb command):               Debugger commands.  (line  356)
* undo() (nel modulo turtle):            Turtle motion.      (line  325)
* undobufferentries() (nel modulo turtle): Special Turtle methods.
                                                             (line   86)
* undoc_header (cmd.Cmd attributo):      Cmd Objects.        (line  166)
* unescape() (nel modulo html):          html — HyperText Markup Language support.
                                                             (line   24)
* unescape() (nel modulo xml.sax.saxutils): xml sax saxutils — SAX Utilities.
                                                             (line   28)
* UnexpectedException:                   Debugging.          (line  208)
* unexpectedSuccesses (unittest.TestResult attributo): Loading and running tests.
                                                             (line  274)
* unfreeze() (nel modulo gc):            gc — Garbage Collector interface.
                                                             (line  255)
* unget_wch() (nel modulo curses):       Functions<5>.       (line  592)
* ungetch() (nel modulo curses):         Functions<5>.       (line  579)
* ungetch() (nel modulo msvcrt):         Console I/O.        (line   45)
* ungetmouse() (nel modulo curses):      Functions<5>.       (line  601)
* ungetwch() (nel modulo msvcrt):        Console I/O.        (line   51)
* unhexlify() (nel modulo binascii):     binascii — Convert between binary and ASCII.
                                                             (line  144)
* Unicode:                               Immutable sequences.
                                                             (line   15)
* Unicode <1>:                           unicodedata — Unicode Database.
                                                             (line    6)
* Unicode <2>:                           codecs — Codec registry and base classes.
                                                             (line    8)
* UNICODE (nel modulo re):               Flags.              (line  117)
* unicode_literals (nel modulo __future__): Module Contents<5>.
                                                             (line   39)
* Unicode;database:                      unicodedata — Unicode Database.
                                                             (line    6)
* UnicodeDecodeError:                    Concrete exceptions.
                                                             (line  484)
* UnicodeEncodeError:                    Concrete exceptions.
                                                             (line  479)
* UnicodeError:                          Concrete exceptions.
                                                             (line  442)
* UnicodeTranslateError:                 Concrete exceptions.
                                                             (line  489)
* UnicodeWarning:                        Warnings.           (line   68)
* unidata_version (nel modulo unicodedata): unicodedata — Unicode Database.
                                                             (line  179)
* unified_diff() (nel modulo difflib):   difflib — Helpers for computing deltas.
                                                             (line  293)
* uniform() (nel modulo random):         Real-valued distributions.
                                                             (line   16)
* UnimplementedFileMode:                 http client — HTTP protocol client.
                                                             (line  154)
* Union (classe in ctypes):              Structured data types.
                                                             (line    6)
* Union (classe in typing):              Special forms.      (line    9)
* union() (frozenset metodo):            Tipi di Insiemi — set frozenset.
                                                             (line  102)
* union() (set metodo):                  Tipi di Insiemi — set frozenset.
                                                             (line  102)
* unione;type:                           Tipo Unione.        (line    6)
* UnionType (classe in types):           Standard Interpreter Types.
                                                             (line  180)
* UNIQUE (enum.EnumCheck attributo):     Data Types<2>.      (line  618)
* unique() (nel modulo enum):            Utilities and Decorators.
                                                             (line   53)
* unittest command line option; -b:      Command-line options<5>.
                                                             (line    8)
* unittest command line option; -buffer: Command-line options<5>.
                                                             (line    8)
* unittest command line option; -c:      Command-line options<5>.
                                                             (line   15)
* unittest command line option; -catch:  Command-line options<5>.
                                                             (line   15)
* unittest command line option; -durations: Command-line options<5>.
                                                             (line   49)
* unittest command line option; -f:      Command-line options<5>.
                                                             (line   24)
* unittest command line option; -failfast: Command-line options<5>.
                                                             (line   24)
* unittest command line option; -k:      Command-line options<5>.
                                                             (line   28)
* unittest command line option; -locals: Command-line options<5>.
                                                             (line   45)
* unittest-discover command line option; -p: Test Discovery. (line   35)
* unittest-discover command line option; -pattern: Test Discovery.
                                                             (line   35)
* unittest-discover command line option; -s: Test Discovery. (line   31)
* unittest-discover command line option; -start-directory: Test Discovery.
                                                             (line   31)
* unittest-discover command line option; -t: Test Discovery. (line   39)
* unittest-discover command line option; -top-level-directory: Test Discovery.
                                                             (line   39)
* unittest-discover command line option; -v: Test Discovery. (line   27)
* unittest-discover command line option; -verbose: Test Discovery.
                                                             (line   27)
* universal newlines:                    Glossary.           (line 1814)
* universal newlines;csv.reader function: Module Contents<3>.
                                                             (line    8)
* universal newlines;importlib.abc.InspectLoader.get_source method: importlib abc – Abstract base classes related to import.
                                                             (line  220)
* universal newlines;io.IncrementalNewlineDecoder class: Text I/O<2>.
                                                             (line  291)
* universal newlines;io.TextIOWrapper class: Text I/O<2>.    (line  127)
* universal newlines;subprocess module:  Frequently Used Arguments.
                                                             (line   33)
* universal newlines;What's new:         PEP 3116 New I/O Library.
                                                             (line   45)
* universal newlines;What's new <1>:     New Improved and Removed Modules.
                                                             (line  138)
* universal newlines;What's new <2>:     PEP 324 New subprocess Module.
                                                             (line   36)
* universal newlines;What's new <3>:     PEP 277 Unicode file name support for Windows NT.
                                                             (line   36)
* UNIX:                                  Complete Python programs.
                                                             (line   25)
* unix_dialect (classe in csv):          Module Contents<3>. (line  219)
* unix_shell (nel modulo test.support):  test support — Utilities for the Python test suite.
                                                             (line   61)
* UNIX;file control:                     fcntl — The fcntl and ioctl system calls.
                                                             (line    6)
* UNIX;I/O control:                      fcntl — The fcntl and ioctl system calls.
                                                             (line    6)
* UnixDatagramServer (classe in socketserver): socketserver — A framework for network servers.
                                                             (line   37)
* UnixStreamServer (classe in socketserver): socketserver — A framework for network servers.
                                                             (line   37)
* unknown (uuid.SafeUUID attributo):     uuid — UUID objects according to RFC 9562.
                                                             (line   45)
* unknown_decl() (html.parser.HTMLParser metodo): HTMLParser Methods.
                                                             (line  136)
* unknown_open() (urllib.request.BaseHandler metodo): BaseHandler Objects.
                                                             (line   56)
* unknown_open() (urllib.request.UnknownHandler metodo): UnknownHandler Objects.
                                                             (line    6)
* UnknownHandler (classe in urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  490)
* UnknownProtocol:                       http client — HTTP protocol client.
                                                             (line  146)
* UnknownTransferEncoding:               http client — HTTP protocol client.
                                                             (line  150)
* unlink() (multiprocessing.shared_memory.SharedMemory metodo): multiprocessing shared_memory — Shared memory for direct access across processes.
                                                             (line  103)
* unlink() (nel modulo os):              Files and Directories.
                                                             (line 1594)
* unlink() (nel modulo test.support.os_helper): test support os_helper — Utilities for os tests.
                                                             (line  167)
* unlink() (pathlib.Path metodo):        Copying moving and deleting.
                                                             (line  108)
* unlink() (xml.dom.minidom.Node metodo): DOM Objects.       (line   10)
* unload() (nel modulo test.support.import_helper): test support import_helper — Utilities for import tests.
                                                             (line   76)
* unlock() (mailbox.Babyl metodo):       Babyl objects.      (line   60)
* unlock() (mailbox.Mailbox metodo):     Mailbox objects.    (line  266)
* unlock() (mailbox.Maildir metodo):     Maildir objects.    (line  209)
* unlock() (mailbox.mbox metodo):        mbox objects.       (line   57)
* unlock() (mailbox.MH metodo):          MH objects.         (line   87)
* unlock() (mailbox.MMDF metodo):        MMDF objects.       (line   47)
* unlockpt() (nel modulo os):            File Descriptor Operations.
                                                             (line  959)
* UNNAMED_SECTION (nel modulo configparser): ConfigParser Objects.
                                                             (line  345)
* UnnamedSectionDisabledError:           Exceptions<8>.      (line   80)
* Unpack (nel modulo typing):            Special forms.      (line  591)
* unpack_archive() (nel modulo shutil):  Archiving operations.
                                                             (line  129)
* UNPACK_EX (opcode):                    Python Bytecode Instructions.
                                                             (line  569)
* unpack_from() (nel modulo struct):     Functions and Exceptions.
                                                             (line   34)
* unpack_from() (struct.Struct metodo):  Classes<2>.         (line   40)
* UNPACK_SEQUENCE (opcode):              Python Bytecode Instructions.
                                                             (line  560)
* unpack() (nel modulo struct):          Functions and Exceptions.
                                                             (line   26)
* unpack() (struct.Struct metodo):       Classes<2>.         (line   34)
* unpacking;dictionary:                  Dictionary displays.
                                                             (line   23)
* unpacking;in function calls:           Calls.              (line   73)
* unparse() (nel modulo ast):            ast helpers.        (line   68)
* unparsedEntityDecl() (xml.sax.handler.DTDHandler metodo): DTDHandler Objects.
                                                             (line   12)
* UnparsedEntityDeclHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  340)
* Unpickler (classe in pickle):          Module Interface.   (line  246)
* UnpicklingError:                       Module Interface.   (line  114)
* unquote_plus() (nel modulo urllib.parse): URL Quoting.     (line   81)
* unquote_to_bytes() (nel modulo urllib.parse): URL Quoting. (line   91)
* unquote() (nel modulo email.utils):    email utils Miscellaneous utilities.
                                                             (line   50)
* unquote() (nel modulo urllib.parse):   URL Quoting.        (line   61)
* unraisablehook() (nel modulo sys):     sys — System-specific parameters and functions.
                                                             (line 2139)
* unreachable object:                    Objects values and types.
                                                             (line   36)
* unrecognized escape sequence:          Hexadecimal Unicode characters.
                                                             (line   17)
* unregister_archive_format() (nel modulo shutil): Archiving operations.
                                                             (line  124)
* unregister_dialect() (nel modulo csv): Module Contents<3>. (line   80)
* unregister_unpack_format() (nel modulo shutil): Archiving operations.
                                                             (line  195)
* unregister() (nel modulo atexit):      atexit — Exit handlers.
                                                             (line   58)
* unregister() (nel modulo codecs):      codecs — Codec registry and base classes.
                                                             (line  170)
* unregister() (nel modulo faulthandler): Dumping the traceback on a user signal.
                                                             (line   23)
* unregister() (select.devpoll metodo):  /dev/poll Polling Objects.
                                                             (line   55)
* unregister() (select.epoll metodo):    Edge and Level Trigger Polling epoll Objects.
                                                             (line   95)
* unregister() (select.poll metodo):     Polling Objects.    (line   67)
* unregister() (selectors.BaseSelector metodo): Classes<3>.  (line   80)
* unsafe (uuid.SafeUUID attributo):      uuid — UUID objects according to RFC 9562.
                                                             (line   41)
* unselect() (imaplib.IMAP4 metodo):     IMAP4 Objects.      (line  457)
* unset() (test.support.os_helper.EnvironmentVarGuard metodo): test support os_helper — Utilities for os tests.
                                                             (line   71)
* unsetenv() (nel modulo os):            Process Parameters. (line  609)
* unshare() (nel modulo os):             Process Parameters. (line  630)
* UnstructuredHeader (classe in email.headerregistry): email headerregistry Custom Header Objects.
                                                             (line  115)
* unsubscribe() (imaplib.IMAP4 metodo):  IMAP4 Objects.      (line  453)
* UnsupportedOperation:                  Exceptions<5>.      (line    6)
* UnsupportedOperation <1>:              High-level Module Interface.
                                                             (line   72)
* until (pdb command):                   Debugger commands.  (line  222)
* untokenize() (nel modulo tokenize):    Tokenizing Input.   (line   57)
* untouchwin() (curses.window metodo):   Window Objects.     (line  592)
* unused_data (bz2.BZ2Decompressor attributo): Incremental de compression.
                                                             (line   78)
* unused_data (compression.zstd.ZstdDecompressor attributo): Compressing and decompressing data in memory.
                                                             (line  215)
* unused_data (lzma.LZMADecompressor attributo): Compressing and decompressing data in memory<2>.
                                                             (line  169)
* unused_data (zlib.Decompress attributo): zlib — Compression compatible with gzip.
                                                             (line  236)
* unverifiable (urllib.request.Request attributo): Request Objects.
                                                             (line   47)
* unwrap() (nel modulo inspect):         Classes and functions<2>.
                                                             (line  139)
* unwrap() (nel modulo urllib.parse):    URL Parsing.        (line  411)
* unwrap() (ssl.SSLSocket metodo):       SSL Sockets.        (line  298)
* up (pdb command):                      Debugger commands.  (line  101)
* up() (nel modulo turtle):              Drawing state.      (line   12)
* update_abstractmethods() (nel modulo abc): abc — Abstract Base Classes.
                                                             (line  337)
* update_authenticated() (urllib.request.HTTPPasswordMgrWithPriorAuth metodo): HTTPPasswordMgrWithPriorAuth Objects.
                                                             (line   24)
* update_lines_cols() (nel modulo curses): Functions<5>.     (line  585)
* update_panels() (nel modulo curses.panel): Functions<6>.   (line   23)
* update_visible() (mailbox.BabylMessage metodo): BabylMessage objects.
                                                             (line   76)
* update_wrapper() (nel modulo functools): functools — Higher-order functions and operations on callable objects.
                                                             (line  699)
* update() (collections.Counter metodo): Counter objects.    (line  122)
* update() (dict metodo):                Tipi di Mapping — dict.
                                                             (line  241)
* update() (hashlib.hash metodo):        Hash Objects.       (line   31)
* update() (hmac.HMAC metodo):           hmac — Keyed-Hashing for Message Authentication.
                                                             (line   51)
* update() (http.cookies.Morsel metodo): Morsel Objects.     (line  105)
* update() (mailbox.Mailbox metodo):     Mailbox objects.    (line  236)
* update() (mailbox.Maildir metodo):     Maildir objects.    (line  193)
* update() (nel modulo turtle):          Animation control.  (line   59)
* update() (set metodo):                 Tipi di Insiemi — set frozenset.
                                                             (line  181)
* update() (trace.CoverageResults metodo): Programmatic Interface.
                                                             (line   52)
* upgrade_dependencies() (venv.EnvBuilder metodo): API<2>.   (line  167)
* upper() (bytearray metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  758)
* upper() (bytes metodo):                Operazioni su Bytes e Bytearray.
                                                             (line  758)
* upper() (str metodo):                  Metodi per le Stringhe.
                                                             (line  885)
* urandom() (nel modulo os):             Random numbers<2>.  (line   29)
* URL:                                   urllib parse — Parse URLs into components.
                                                             (line    8)
* URL <1>:                               urllib robotparser — Parser for robots txt.
                                                             (line    8)
* URL <2>:                               http server — HTTP servers.
                                                             (line    8)
* url (http.client.HTTPResponse attributo): HTTPResponse Objects.
                                                             (line   51)
* url (urllib.error.HTTPError attributo): urllib error — Exception classes raised by urllib request.
                                                             (line   39)
* url (urllib.response.addinfourl attributo): urllib response — Response classes used by urllib.
                                                             (line   14)
* url (xmlrpc.client.ProtocolError attributo): ProtocolError Objects.
                                                             (line   13)
* URL;parsing:                           urllib parse — Parse URLs into components.
                                                             (line    8)
* url2pathname() (nel modulo urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line  169)
* urlcleanup() (nel modulo urllib.request): Legacy interface.
                                                             (line   62)
* urldefrag() (nel modulo urllib.parse): URL Parsing.        (line  385)
* urlencode() (nel modulo urllib.parse): URL Quoting.        (line  104)
* URLError:                              urllib error — Exception classes raised by urllib request.
                                                             (line   17)
* urljoin() (nel modulo urllib.parse):   URL Parsing.        (line  348)
* urlopen() (nel modulo urllib.request): urllib request — Extensible library for opening URLs.
                                                             (line   33)
* urlparse() (nel modulo urllib.parse):  URL Parsing.        (line    9)
* urlretrieve() (nel modulo urllib.request): Legacy interface.
                                                             (line   10)
* urlsafe_b64decode() (nel modulo base64): RFC 4648 Encodings.
                                                             (line   66)
* urlsafe_b64encode() (nel modulo base64): RFC 4648 Encodings.
                                                             (line   59)
* urlsplit() (nel modulo urllib.parse):  URL Parsing.        (line  257)
* urlunparse() (nel modulo urllib.parse): URL Parsing.       (line  249)
* urlunsplit() (nel modulo urllib.parse): URL Parsing.       (line  339)
* urn (uuid.UUID attributo):             uuid — UUID objects according to RFC 9562.
                                                             (line  150)
* US (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line  118)
* use_default_colors() (nel modulo curses): Functions<5>.    (line  616)
* use_env() (nel modulo curses):         Functions<5>.       (line  606)
* use_rawinput (cmd.Cmd attributo):      Cmd Objects.        (line  177)
* USE_STACKCHECK (C macro):              Operating System Utilities.
                                                             (line   91)
* use_tool_id() (nel modulo sys.monitoring): Registering and using tools.
                                                             (line    6)
* UseForeignDTD() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line   63)
* USER:                                  getpass — Portable password input.
                                                             (line   59)
* USER_BASE (nel modulo site):           Module contents<5>. (line   31)
* user_call() (bdb.Bdb metodo):          bdb — Debugger framework.
                                                             (line  296)
* user_exception() (bdb.Bdb metodo):     bdb — Debugger framework.
                                                             (line  315)
* user_line() (bdb.Bdb metodo):          bdb — Debugger framework.
                                                             (line  304)
* user_return() (bdb.Bdb metodo):        bdb — Debugger framework.
                                                             (line  310)
* USER_SITE (nel modulo site):           Module contents<5>. (line   19)
* user-defined;function:                 User-defined functions.
                                                             (line    6)
* user-defined;function;call:            Calls.              (line  132)
* user-defined;method:                   Instance methods.   (line    6)
* user;effective id:                     Process Parameters. (line  210)
* user;id:                               Process Parameters. (line  358)
* user;id, setting:                      Process Parameters. (line  550)
* user() (poplib.POP3 metodo):           POP3 Objects.       (line   31)
* usercustomize:                         I Moduli di Personalizzazione.
                                                             (line    7)
* usercustomize <1>:                     I Moduli di Personalizzazione.
                                                             (line   22)
* UserDict (classe in collections):      UserDict objects.   (line   12)
* UserList (classe in collections):      UserList objects.   (line   16)
* USERNAME:                              os path — Common pathname manipulations.
                                                             (line  150)
* USERNAME <1>:                          Process Parameters. (line  262)
* USERNAME <2>:                          getpass — Portable password input.
                                                             (line   60)
* username (email.headerregistry.Address attributo): email headerregistry Custom Header Objects.
                                                             (line  432)
* USERPROFILE:                           os path<5>.         (line   14)
* USERPROFILE <1>:                       Changes in the Python API<5>.
                                                             (line  117)
* USERPROFILE <2>:                       Windows<47>.        (line   15)
* USERPROFILE <3>:                       os path — Common pathname manipulations.
                                                             (line  147)
* userptr() (curses.panel.Panel metodo): Panel Objects.      (line   57)
* UserString (classe in collections):    UserString objects. (line   12)
* UserWarning:                           Warnings.           (line   13)
* USTAR_FORMAT (nel modulo tarfile):     tarfile — Read and write tar archive files.
                                                             (line  373)
* USub (classe in ast):                  Expressions<2>.     (line   27)
* UTC:                                   time — Time access and conversions.
                                                             (line   39)
* utc (datetime.timezone attributo):     timezone Objects.   (line   68)
* UTC (nel modulo datetime):             Constants.          (line   18)
* utcfromtimestamp() (datetime.datetime metodo della classe): datetime Objects.
                                                             (line  131)
* utcnow() (datetime.datetime metodo della classe): datetime Objects.
                                                             (line   81)
* utcoffset() (datetime.datetime metodo): datetime Objects.  (line  528)
* utcoffset() (datetime.time metodo):    time Objects.       (line  253)
* utcoffset() (datetime.timezone metodo): timezone Objects.  (line   30)
* utcoffset() (datetime.tzinfo metodo):  tzinfo Objects.     (line   38)
* utctimetuple() (datetime.datetime metodo): datetime Objects.
                                                             (line  573)
* utf8 (email.policy.EmailPolicy attributo): email policy Policy Objects.
                                                             (line  380)
* utf8_enabled (imaplib.IMAP4 attributo): IMAP4 Objects.     (line  485)
* utf8_mode (sys.flags attributo):       sys — System-specific parameters and functions.
                                                             (line  581)
* utf8() (poplib.POP3 metodo):           POP3 Objects.       (line  106)
* utime() (nel modulo os):               Files and Directories.
                                                             (line 1608)
* UUID (classe in uuid):                 uuid — UUID objects according to RFC 9562.
                                                             (line   50)
* uuid command line option; -C:          Command-Line Usage. (line   42)
* uuid command line option; -count:      Command-Line Usage. (line   42)
* uuid command line option; -h:          Command-Line Usage. (line   15)
* uuid command line option; -help:       Command-Line Usage. (line   15)
* uuid command line option; -n:          Command-Line Usage. (line   28)
* uuid command line option; -N:          Command-Line Usage. (line   36)
* uuid command line option; -name:       Command-Line Usage. (line   36)
* uuid command line option; -namespace:  Command-Line Usage. (line   28)
* uuid command line option; -u:          Command-Line Usage. (line   19)
* uuid command line option; -uuid:       Command-Line Usage. (line   19)
* uuid1() (nel modulo uuid):             uuid — UUID objects according to RFC 9562.
                                                             (line  196)
* uuid3() (nel modulo uuid):             uuid — UUID objects according to RFC 9562.
                                                             (line  209)
* uuid4() (nel modulo uuid):             uuid — UUID objects according to RFC 9562.
                                                             (line  216)
* uuid5() (nel modulo uuid):             uuid — UUID objects according to RFC 9562.
                                                             (line  221)
* uuid6() (nel modulo uuid):             uuid — UUID objects according to RFC 9562.
                                                             (line  228)
* uuid7() (nel modulo uuid):             uuid — UUID objects according to RFC 9562.
                                                             (line  246)
* uuid8() (nel modulo uuid):             uuid — UUID objects according to RFC 9562.
                                                             (line  256)
* v4_int_to_packed() (nel modulo ipaddress): Other Module Level Functions.
                                                             (line    8)
* v6_int_to_packed() (nel modulo ipaddress): Other Module Level Functions.
                                                             (line   20)
* valid_signals() (nel modulo signal):   Module contents<2>. (line  332)
* validator() (nel modulo wsgiref.validate): wsgiref validate — WSGI conformance checker.
                                                             (line   22)
* value:                                 Dictionary displays.
                                                             (line    6)
* VALUE (annotationlib.Format attributo): Classes<4>.        (line   14)
* value (ctypes._SimpleCData attributo): Fundamental data types<2>.
                                                             (line   17)
* value (enum.Enum attributo):           Data Types<2>.      (line  132)
* value (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   32)
* value (http.cookies.Morsel attributo): Morsel Objects.     (line   63)
* value (StopIteration attributo):       Concrete exceptions.
                                                             (line  278)
* value (string.templatelib.Interpolation attributo): Types. (line  215)
* value (xml.dom.Attr attributo):        Attr Objects.       (line   23)
* value of an object:                    Objects values and types.
                                                             (line   10)
* value_decode() (http.cookies.BaseCookie metodo): Cookie Objects.
                                                             (line    6)
* value_encode() (http.cookies.BaseCookie metodo): Cookie Objects.
                                                             (line   13)
* VALUE_WITH_FAKE_GLOBALS (annotationlib.Format attributo): Classes<4>.
                                                             (line   19)
* Value() (multiprocessing.managers.SyncManager metodo): Managers.
                                                             (line  219)
* Value() (nel modulo multiprocessing.sharedctypes): The multiprocessing sharedctypes module.
                                                             (line   71)
* Value() (nel modulo multiprocessing):  Shared ctypes Objects.
                                                             (line    9)
* ValueError:                            Concrete exceptions.
                                                             (line  494)
* valuerefs() (weakref.WeakValueDictionary metodo): weakref — Weak references.
                                                             (line  227)
* Values (classe in optparse):           Defining options.   (line   84)
* values (string.templatelib.Template attributo): Types.     (line   90)
* values() (contextvars.Context metodo): Manual Context Management.
                                                             (line  137)
* values() (dict metodo):                Tipi di Mapping — dict.
                                                             (line  259)
* values() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  236)
* values() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  348)
* values() (mailbox.Mailbox metodo):     Mailbox objects.    (line  129)
* values() (types.MappingProxyType metodo): Standard Interpreter Types.
                                                             (line  280)
* ValuesView (classe in collections.abc): Collections Abstract Base Classes – Detailed Descriptions.
                                                             (line  125)
* ValuesView (classe in typing):         Aliases to container ABCs in collections abc.
                                                             (line  120)
* var (contextvars.Token attributo):     Context Variables.  (line  118)
* variabile d'ambiente, __PYVENV_LAUNCHER__: PyConfig.       (line  187)
* variabile d'ambiente, __PYVENV_LAUNCHER__ <1>: PyConfig.   (line  731)
* variabile d'ambiente, BASECFLAGS:      Compiler flags.     (line   66)
* variabile d'ambiente, BASECPPFLAGS:    Preprocessor flags. (line   22)
* variabile d'ambiente, BLDSHARED:       Linker flags.       (line   67)
* variabile d'ambiente, BROWSER:         webbrowser.         (line    6)
* variabile d'ambiente, BROWSER <1>:     webbrowser.         (line   10)
* variabile d'ambiente, BROWSER <2>:     Library<23>.        (line  420)
* variabile d'ambiente, BROWSER <3>:     Library<23>.        (line  424)
* variabile d'ambiente, BROWSER <4>:     webbrowser — Convenient web-browser controller.
                                                             (line   20)
* variabile d'ambiente, BROWSER <5>:     webbrowser — Convenient web-browser controller.
                                                             (line   30)
* variabile d'ambiente, BROWSER <6>:     webbrowser — Convenient web-browser controller.
                                                             (line   41)
* variabile d'ambiente, BROWSER <7>:     Command-line interface<6>.
                                                             (line   86)
* variabile d'ambiente, CC:              New Improved and Deprecated Modules<4>.
                                                             (line   58)
* variabile d'ambiente, CC <1>:          Compiler flags.     (line    6)
* variabile d'ambiente, CCSHARED:        Compiler flags.     (line   81)
* variabile d'ambiente, CFLAGS:          New Improved and Deprecated Modules<4>.
                                                             (line   59)
* variabile d'ambiente, CFLAGS <1>:      Performance options.
                                                             (line   28)
* variabile d'ambiente, CFLAGS <2>:      Compiler flags.     (line   18)
* variabile d'ambiente, CFLAGS <3>:      Compiler flags.     (line   26)
* variabile d'ambiente, CFLAGS <4>:      Compiler flags.     (line   28)
* variabile d'ambiente, CFLAGS <5>:      Compiler flags.     (line   32)
* variabile d'ambiente, CFLAGS <6>:      Compiler flags.     (line   54)
* variabile d'ambiente, CFLAGS <7>:      Linker flags.       (line   18)
* variabile d'ambiente, CFLAGS_ALIASING: Compiler flags.     (line   74)
* variabile d'ambiente, CFLAGS_NODIST:   Compiler flags.     (line   22)
* variabile d'ambiente, CFLAGS_NODIST <1>: Compiler flags.   (line   24)
* variabile d'ambiente, CFLAGS_NODIST <2>: Compiler flags.   (line   61)
* variabile d'ambiente, CFLAGS_NODIST <3>: Linker flags.     (line   26)
* variabile d'ambiente, CFLAGSFORSHARED: Compiler flags.     (line   87)
* variabile d'ambiente, COLUMNS:         Functions<5>.       (line  611)
* variabile d'ambiente, COLUMNS <1>:     Functions<5>.       (line  614)
* variabile d'ambiente, COMPILEALL_OPTS: Compiler flags.     (line   41)
* variabile d'ambiente, COMSPEC:         Process Management. (line  786)
* variabile d'ambiente, COMSPEC <1>:     Popen Constructor.  (line  112)
* variabile d'ambiente, CONFIGURE_CFLAGS: Compiler flags.    (line   52)
* variabile d'ambiente, CONFIGURE_CFLAGS_NODIST: Compiler flags.
                                                             (line   59)
* variabile d'ambiente, CONFIGURE_CPPFLAGS: Preprocessor flags.
                                                             (line    6)
* variabile d'ambiente, CONFIGURE_LDFLAGS: Linker flags.     (line   13)
* variabile d'ambiente, CONFIGURE_LDFLAGS_NODIST: Linker flags.
                                                             (line   38)
* variabile d'ambiente, CPPFLAGS:        New Improved and Deprecated Modules<4>.
                                                             (line   59)
* variabile d'ambiente, CPPFLAGS <1>:    Preprocessor flags. (line    8)
* variabile d'ambiente, CPPFLAGS <2>:    Preprocessor flags. (line   13)
* variabile d'ambiente, CPPFLAGS <3>:    Preprocessor flags. (line   18)
* variabile d'ambiente, CPPFLAGS <4>:    Linker flags.       (line   50)
* variabile d'ambiente, CXX:             Compiler flags.     (line   12)
* variabile d'ambiente, DISPLAY:         Tkinter Modules.    (line   27)
* variabile d'ambiente, EnableControlFlowGuard: Build<42>.   (line   47)
* variabile d'ambiente, EXTRA_CFLAGS:    Compiler flags.     (line   48)
* variabile d'ambiente, HOME:            os path<5>.         (line   15)
* variabile d'ambiente, HOME <1>:        Changes in the Python API<5>.
                                                             (line  118)
* variabile d'ambiente, HOME <2>:        Windows<47>.        (line   15)
* variabile d'ambiente, HOME <3>:        Windows<47>.        (line   18)
* variabile d'ambiente, HOME <4>:        os path — Common pathname manipulations.
                                                             (line  141)
* variabile d'ambiente, HOME <5>:        os path — Common pathname manipulations.
                                                             (line  158)
* variabile d'ambiente, HOME <6>:        Tkinter Modules.    (line   66)
* variabile d'ambiente, HOMEDRIVE:       os path — Common pathname manipulations.
                                                             (line  148)
* variabile d'ambiente, HOMEPATH:        os path — Common pathname manipulations.
                                                             (line  148)
* variabile d'ambiente, IDLESTARTUP:     IDLE<37>.           (line  176)
* variabile d'ambiente, IDLESTARTUP <1>: IDLE<41>.           (line    9)
* variabile d'ambiente, IDLESTARTUP <2>: IDLE<47>.           (line    9)
* variabile d'ambiente, IDLESTARTUP <3>: Startup and Code Execution.
                                                             (line    7)
* variabile d'ambiente, IDLESTARTUP <4>: Command-line usage<5>.
                                                             (line   41)
* variabile d'ambiente, LANG:            GNU gettext API.    (line   21)
* variabile d'ambiente, LANG <1>:        Class-based API.    (line   26)
* variabile d'ambiente, LANG <2>:        locale — Internationalization services.
                                                             (line   63)
* variabile d'ambiente, LANG <3>:        locale — Internationalization services.
                                                             (line  368)
* variabile d'ambiente, LANG <4>:        locale — Internationalization services.
                                                             (line  372)
* variabile d'ambiente, LANGUAGE:        GNU gettext API.    (line   20)
* variabile d'ambiente, LANGUAGE <1>:    Class-based API.    (line   25)
* variabile d'ambiente, LC_ALL:          GNU gettext API.    (line   20)
* variabile d'ambiente, LC_ALL <1>:      Class-based API.    (line   25)
* variabile d'ambiente, LC_MESSAGES:     GNU gettext API.    (line   20)
* variabile d'ambiente, LC_MESSAGES <1>: Class-based API.    (line   26)
* variabile d'ambiente, LDFLAGS:         New Improved and Deprecated Modules<4>.
                                                             (line   59)
* variabile d'ambiente, LDFLAGS <1>:     Preprocessor flags. (line   18)
* variabile d'ambiente, LDFLAGS <2>:     Linker flags.       (line   15)
* variabile d'ambiente, LDFLAGS <3>:     Linker flags.       (line   18)
* variabile d'ambiente, LDFLAGS <4>:     Linker flags.       (line   28)
* variabile d'ambiente, LDFLAGS <5>:     Linker flags.       (line   31)
* variabile d'ambiente, LDFLAGS <6>:     Linker flags.       (line   35)
* variabile d'ambiente, LDFLAGS <7>:     Linker flags.       (line   45)
* variabile d'ambiente, LDFLAGS <8>:     Linker flags.       (line   50)
* variabile d'ambiente, LDFLAGS_NODIST:  Linker flags.       (line   24)
* variabile d'ambiente, LDFLAGS_NODIST <1>: Linker flags.    (line   26)
* variabile d'ambiente, LDFLAGS_NODIST <2>: Linker flags.    (line   40)
* variabile d'ambiente, LDSHARED:        Linker flags.       (line   61)
* variabile d'ambiente, LIBS:            Linker flags.       (line   54)
* variabile d'ambiente, LINES:           Functions<5>.       (line  140)
* variabile d'ambiente, LINES <1>:       Functions<5>.       (line  611)
* variabile d'ambiente, LINES <2>:       Functions<5>.       (line  613)
* variabile d'ambiente, LINKCC:          Linker flags.       (line    6)
* variabile d'ambiente, LOGNAME:         Process Parameters. (line  262)
* variabile d'ambiente, LOGNAME <1>:     getpass — Portable password input.
                                                             (line   59)
* variabile d'ambiente, MANPAGER:        pydoc — Documentation generator and online help system.
                                                             (line   46)
* variabile d'ambiente, MANPAGER <1>:    pydoc — Documentation generator and online help system.
                                                             (line   48)
* variabile d'ambiente, no_proxy:        urllib request — Extensible library for opening URLs.
                                                             (line  354)
* variabile d'ambiente, OPT:             Debug options.      (line   39)
* variabile d'ambiente, OPT <1>:         Compiler flags.     (line   70)
* variabile d'ambiente, PAGER:           pydoc — Documentation generator and online help system.
                                                             (line   46)
* variabile d'ambiente, PATH:            Changes in the Python API<5>.
                                                             (line  145)
* variabile d'ambiente, PATH <1>:        Changes in “python” Command Behavior<2>.
                                                             (line    6)
* variabile d'ambiente, PATH <2>:        Changes in “python” Command Behavior<2>.
                                                             (line   11)
* variabile d'ambiente, PATH <3>:        Changes in “python” Command Behavior<2>.
                                                             (line   12)
* variabile d'ambiente, PATH <4>:        macOS<8>.           (line   14)
* variabile d'ambiente, PATH <5>:        Windows<28>.        (line   56)
* variabile d'ambiente, PATH <6>:        Windows<32>.        (line   14)
* variabile d'ambiente, PATH <7>:        Security<44>.       (line   16)
* variabile d'ambiente, PATH <8>:        Security<44>.       (line   20)
* variabile d'ambiente, PATH <9>:        Il percorso di ricerca del modulo.
                                                             (line   17)
* variabile d'ambiente, PATH <10>:       Script Eseguibili Python.
                                                             (line   11)
* variabile d'ambiente, PATH <11>:       Environment variables.
                                                             (line   27)
* variabile d'ambiente, PATH <12>:       Miscellaneous.      (line   16)
* variabile d'ambiente, PATH <13>:       Installation.       (line   19)
* variabile d'ambiente, PATH <14>:       Installation.       (line   24)
* variabile d'ambiente, PATH <15>:       Installation.       (line   32)
* variabile d'ambiente, PATH <16>:       Configuration.      (line  114)
* variabile d'ambiente, PATH <17>:       Shebang lines.      (line   40)
* variabile d'ambiente, PATH <18>:       Shebang lines.      (line   42)
* variabile d'ambiente, PATH <19>:       Shebang lines.      (line   49)
* variabile d'ambiente, PATH <20>:       Advanced installation.
                                                             (line   10)
* variabile d'ambiente, PATH <21>:       Advanced installation.
                                                             (line   28)
* variabile d'ambiente, PATH <22>:       Advanced installation.
                                                             (line   31)
* variabile d'ambiente, PATH <23>:       Installing free-threaded binaries.
                                                             (line   18)
* variabile d'ambiente, PATH <24>:       Troubleshooting.    (line   33)
* variabile d'ambiente, PATH <25>:       Troubleshooting.    (line   52)
* variabile d'ambiente, PATH <26>:       Troubleshooting.    (line   68)
* variabile d'ambiente, PATH <27>:       Troubleshooting.    (line  110)
* variabile d'ambiente, PATH <28>:       Installation steps. (line   34)
* variabile d'ambiente, PATH <29>:       Installation steps. (line   58)
* variabile d'ambiente, PATH <30>:       Installing without UI.
                                                             (line   77)
* variabile d'ambiente, PATH <31>:       Installing without UI.
                                                             (line   81)
* variabile d'ambiente, PATH <32>:       Python launcher for Windows deprecated.
                                                             (line   17)
* variabile d'ambiente, PATH <33>:       From the command-line.
                                                             (line    9)
* variabile d'ambiente, PATH <34>:       Shebang lines<2>.   (line   54)
* variabile d'ambiente, PATH <35>:       Shebang lines<2>.   (line   60)
* variabile d'ambiente, PATH <36>:       Shebang lines<2>.   (line   62)
* variabile d'ambiente, PATH <37>:       Shebang lines<2>.   (line   67)
* variabile d'ambiente, PATH <38>:       Comparison to the os and os path modules.
                                                             (line   41)
* variabile d'ambiente, PATH <39>:       Directory and files operations.
                                                             (line  449)
* variabile d'ambiente, PATH <40>:       Directory and files operations.
                                                             (line  454)
* variabile d'ambiente, PATH <41>:       Process Management. (line   45)
* variabile d'ambiente, PATH <42>:       Process Management. (line   86)
* variabile d'ambiente, PATH <43>:       Process Management. (line   89)
* variabile d'ambiente, PATH <44>:       Process Management. (line   92)
* variabile d'ambiente, PATH <45>:       Process Management. (line  549)
* variabile d'ambiente, PATH <46>:       Process Management. (line  636)
* variabile d'ambiente, PATH <47>:       Process Management. (line  640)
* variabile d'ambiente, PATH <48>:       Process Management. (line  642)
* variabile d'ambiente, PATH <49>:       Miscellaneous System Information.
                                                             (line  141)
* variabile d'ambiente, PATH <50>:       Popen Constructor.  (line   35)
* variabile d'ambiente, PATH <51>:       webbrowser — Convenient web-browser controller.
                                                             (line   59)
* variabile d'ambiente, PATH <52>:       webbrowser — Convenient web-browser controller.
                                                             (line   33)
* variabile d'ambiente, PATH <53>:       How venvs work.     (line   16)
* variabile d'ambiente, PATH <54>:       How venvs work.     (line   61)
* variabile d'ambiente, PATH <55>:       How venvs work.     (line   66)
* variabile d'ambiente, PATH <56>:       site — Site-specific configuration hook.
                                                             (line   71)
* variabile d'ambiente, PATH <57>:       Embedding Python<2>.
                                                             (line   31)
* variabile d'ambiente, PATH <58>:       Embedding Python<2>.
                                                             (line   37)
* variabile d'ambiente, PATH <59>:       How do I make a Python script executable on Unix?.
                                                             (line   24)
* variabile d'ambiente, PATH <60>:       How do I make a Python script executable on Unix?.
                                                             (line   28)
* variabile d'ambiente, PATHEXT:         Other Improvements<2>.
                                                             (line   30)
* variabile d'ambiente, PATHEXT <1>:     Library<134>.       (line  138)
* variabile d'ambiente, PATHEXT <2>:     Installing without UI.
                                                             (line   77)
* variabile d'ambiente, PATHEXT <3>:     Installing without UI.
                                                             (line   81)
* variabile d'ambiente, PATHEXT <4>:     Directory and files operations.
                                                             (line  464)
* variabile d'ambiente, PIP_USER:        Windows<49>.        (line  102)
* variabile d'ambiente, PROFILE_TASK:    Build<22>.          (line   13)
* variabile d'ambiente, PROFILE_TASK <1>: Performance options.
                                                             (line   12)
* variabile d'ambiente, PROFILE_TASK <2>: Performance options.
                                                             (line   35)
* variabile d'ambiente, PURIFY:          Compiler flags.     (line  130)
* variabile d'ambiente, PY_BUILTIN_MODULE_CFLAGS: Compiler flags.
                                                             (line  121)
* variabile d'ambiente, PY_CFLAGS:       Compiler flags.     (line   94)
* variabile d'ambiente, PY_CFLAGS_NODIST: Compiler flags.    (line   99)
* variabile d'ambiente, PY_CORE_CFLAGS:  Compiler flags.     (line  115)
* variabile d'ambiente, PY_CORE_LDFLAGS: Linker flags.       (line   83)
* variabile d'ambiente, PY_CPPFLAGS:     Preprocessor flags. (line   26)
* variabile d'ambiente, PY_LDFLAGS:      Linker flags.       (line   73)
* variabile d'ambiente, PY_LDFLAGS_NODIST: Linker flags.     (line   77)
* variabile d'ambiente, PY_STDMODULE_CFLAGS: Compiler flags. (line  106)
* variabile d'ambiente, PYLAUNCHER_ALLOW_INSTALL: Windows<16>.
                                                             (line   24)
* variabile d'ambiente, PYLAUNCHER_ALLOW_INSTALL <1>: Windows<30>.
                                                             (line   15)
* variabile d'ambiente, PYTHON_BASIC_REPL: Default interactive shell.
                                                             (line    7)
* variabile d'ambiente, PYTHON_BASIC_REPL <1>: A better interactive interpreter.
                                                             (line   27)
* variabile d'ambiente, PYTHON_BASIC_REPL <2>: Library<45>.  (line   52)
* variabile d'ambiente, PYTHON_BASIC_REPL <3>: Library<45>.  (line   56)
* variabile d'ambiente, PYTHON_BASIC_REPL <4>: Core and Builtins<46>.
                                                             (line   13)
* variabile d'ambiente, PYTHON_BASIC_REPL <5>: Modalità Interattiva<2>.
                                                             (line   24)
* variabile d'ambiente, PYTHON_BASIC_REPL <6>: Environment variables.
                                                             (line  538)
* variabile d'ambiente, PYTHON_BASIC_REPL <7>: Example.      (line   80)
* variabile d'ambiente, PYTHON_BASIC_REPL <8>: asyncio — Asynchronous I/O.
                                                             (line   81)
* variabile d'ambiente, PYTHON_COLORS:   Summary – Release Highlights.
                                                             (line   57)
* variabile d'ambiente, PYTHON_COLORS <1>: Improved error messages<2>.
                                                             (line    8)
* variabile d'ambiente, PYTHON_COLORS <2>: doctest.          (line    7)
* variabile d'ambiente, PYTHON_COLORS <3>: Controlling color.
                                                             (line   22)
* variabile d'ambiente, PYTHON_COLORS <4>: Environment variables.
                                                             (line  530)
* variabile d'ambiente, PYTHON_COLORS <5>: color.            (line   24)
* variabile d'ambiente, PYTHON_CONTEXT_AWARE_WARNINGS: Library<23>.
                                                             (line  369)
* variabile d'ambiente, PYTHON_CONTEXT_AWARE_WARNINGS <1>: Miscellaneous options.
                                                             (line  434)
* variabile d'ambiente, PYTHON_CONTEXT_AWARE_WARNINGS <2>: Environment variables.
                                                             (line  578)
* variabile d'ambiente, PYTHON_CONTEXT_AWARE_WARNINGS <3>: sys — System-specific parameters and functions.
                                                             (line  601)
* variabile d'ambiente, PYTHON_CONTEXT_AWARE_WARNINGS <4>: Concurrent safety of Context Managers.
                                                             (line   41)
* variabile d'ambiente, PYTHON_CPU_COUNT: os<2>.             (line   11)
* variabile d'ambiente, PYTHON_CPU_COUNT <1>: Miscellaneous options.
                                                             (line  398)
* variabile d'ambiente, PYTHON_CPU_COUNT <2>: Environment variables.
                                                             (line  506)
* variabile d'ambiente, PYTHON_CPU_COUNT <3>: Miscellaneous System Information.
                                                             (line   49)
* variabile d'ambiente, PYTHON_CPU_COUNT <4>: Miscellaneous System Information.
                                                             (line   69)
* variabile d'ambiente, PYTHON_CPU_COUNT <5>: Miscellaneous<4>.
                                                             (line   31)
* variabile d'ambiente, PYTHON_CPU_COUNT <6>: PyConfig.      (line  523)
* variabile d'ambiente, PYTHON_DISABLE_REMOTE_DEBUG: PEP 768 Safe external debugger interface.
                                                             (line   40)
* variabile d'ambiente, PYTHON_DISABLE_REMOTE_DEBUG <1>: Miscellaneous options.
                                                             (line  389)
* variabile d'ambiente, PYTHON_DISABLE_REMOTE_DEBUG <2>: Environment variables.
                                                             (line  493)
* variabile d'ambiente, PYTHON_DISABLE_REMOTE_DEBUG <3>: Disabling remote debugging.
                                                             (line    8)
* variabile d'ambiente, PYTHON_DOM:      Module Contents<4>. (line   23)
* variabile d'ambiente, PYTHON_FROZEN_MODULES: Other Language Changes.
                                                             (line   46)
* variabile d'ambiente, PYTHON_FROZEN_MODULES <1>: Core and Builtins<57>.
                                                             (line  105)
* variabile d'ambiente, PYTHON_FROZEN_MODULES <2>: Miscellaneous options.
                                                             (line  357)
* variabile d'ambiente, PYTHON_FROZEN_MODULES <3>: Environment variables.
                                                             (line  516)
* variabile d'ambiente, PYTHON_FROZEN_MODULES <4>: PyConfig. (line  420)
* variabile d'ambiente, PYTHON_GIL:      Free-threaded CPython.
                                                             (line   22)
* variabile d'ambiente, PYTHON_GIL <1>:  Free-threaded CPython.
                                                             (line   38)
* variabile d'ambiente, PYTHON_GIL <2>:  Core and Builtins<42>.
                                                             (line   50)
* variabile d'ambiente, PYTHON_GIL <3>:  Miscellaneous options.
                                                             (line  416)
* variabile d'ambiente, PYTHON_GIL <4>:  Environment variables.
                                                             (line  555)
* variabile d'ambiente, PYTHON_GIL <5>:  sys — System-specific parameters and functions.
                                                             (line  594)
* variabile d'ambiente, PYTHON_GIL <6>:  The global interpreter lock in free-threaded Python.
                                                             (line    7)
* variabile d'ambiente, PYTHON_GIL <7>:  Glossary.           (line  794)
* variabile d'ambiente, PYTHON_HISTORY:  Other Language Changes.
                                                             (line   57)
* variabile d'ambiente, PYTHON_HISTORY <1>: Library<61>.     (line  544)
* variabile d'ambiente, PYTHON_HISTORY <2>: Environment variables.
                                                             (line  547)
* variabile d'ambiente, PYTHON_JIT:      Binary releases for the experimental just-in-time compiler.
                                                             (line    8)
* variabile d'ambiente, PYTHON_JIT <1>:  Environment variables.
                                                             (line  588)
* variabile d'ambiente, PYTHON_JIT <2>:  General Options.    (line  238)
* variabile d'ambiente, PYTHON_JIT <3>:  General Options.    (line  241)
* variabile d'ambiente, PYTHON_JIT <4>:  General Options.    (line  246)
* variabile d'ambiente, PYTHON_JIT <5>:  sys — System-specific parameters and functions.
                                                             (line 1297)
* variabile d'ambiente, PYTHON_MANAGER_AUTOMATIC_INSTALL: Installing runtimes.
                                                             (line   41)
* variabile d'ambiente, PYTHON_MANAGER_AUTOMATIC_INSTALL <1>: Configuration.
                                                             (line   58)
* variabile d'ambiente, PYTHON_MANAGER_DEFAULT: Basic use.   (line   46)
* variabile d'ambiente, PYTHON_MANAGER_DEFAULT <1>: Configuration.
                                                             (line   37)
* variabile d'ambiente, PYTHON_MANAGER_DEFAULT <2>: Troubleshooting.
                                                             (line   76)
* variabile d'ambiente, PYTHON_PERF_JIT_SUPPORT: Other Language Changes.
                                                             (line   52)
* variabile d'ambiente, PYTHON_PERF_JIT_SUPPORT <1>: Miscellaneous options.
                                                             (line  376)
* variabile d'ambiente, PYTHON_PERF_JIT_SUPPORT <2>: Environment variables.
                                                             (line  480)
* variabile d'ambiente, PYTHON_PERF_JIT_SUPPORT <3>: PyConfig.
                                                             (line  908)
* variabile d'ambiente, PYTHON_PERF_JIT_SUPPORT <4>: How to work without frame pointers.
                                                             (line   14)
* variabile d'ambiente, PYTHON_PRESITE:  Miscellaneous options.
                                                             (line  410)
* variabile d'ambiente, PYTHON_PRESITE <1>: Debug-mode variables.
                                                             (line   25)
* variabile d'ambiente, PYTHON_PRESITE <2>: PyConfig.        (line  802)
* variabile d'ambiente, PYTHON_PRESITE=package.module: Core and Builtins<57>.
                                                             (line  154)
* variabile d'ambiente, PYTHON_THREAD_INHERIT_CONTEXT: Core and Builtins<23>.
                                                             (line  135)
* variabile d'ambiente, PYTHON_THREAD_INHERIT_CONTEXT <1>: Miscellaneous options.
                                                             (line  426)
* variabile d'ambiente, PYTHON_THREAD_INHERIT_CONTEXT <2>: Environment variables.
                                                             (line  567)
* variabile d'ambiente, PYTHON_THREAD_INHERIT_CONTEXT <3>: sys — System-specific parameters and functions.
                                                             (line  597)
* variabile d'ambiente, PYTHON_TLBC:     Miscellaneous options.
                                                             (line  442)
* variabile d'ambiente, PYTHON_TLBC <1>: Environment variables.
                                                             (line  596)
* variabile d'ambiente, PYTHONASYNCIODEBUG: Environment variables.
                                                             (line  283)
* variabile d'ambiente, PYTHONASYNCIODEBUG <1>: Enabling debug mode.
                                                             (line   10)
* variabile d'ambiente, PYTHONASYNCIODEBUG <2>: Debug Mode.  (line   11)
* variabile d'ambiente, PYTHONASYNCIODEBUG <3>: Effects of the Python Development Mode.
                                                             (line   65)
* variabile d'ambiente, PYTHONBREAKPOINT: PEP 553 Built-in breakpoint.
                                                             (line   13)
* variabile d'ambiente, PYTHONBREAKPOINT <1>: Environment variables.
                                                             (line   81)
* variabile d'ambiente, PYTHONBREAKPOINT <2>: Funzioni Incorporate.
                                                             (line  165)
* variabile d'ambiente, PYTHONBREAKPOINT <3>: sys — System-specific parameters and functions.
                                                             (line  256)
* variabile d'ambiente, PYTHONBREAKPOINT <4>: sys — System-specific parameters and functions.
                                                             (line  270)
* variabile d'ambiente, PYTHONBREAKPOINT <5>: sys — System-specific parameters and functions.
                                                             (line  274)
* variabile d'ambiente, PYTHONCASEOK:    Changes in the Python API<4>.
                                                             (line   29)
* variabile d'ambiente, PYTHONCASEOK <1>: PEP 235 Importing Modules on Case-Insensitive Platforms.
                                                             (line   17)
* variabile d'ambiente, PYTHONCASEOK <2>: Library<152>.      (line  144)
* variabile d'ambiente, PYTHONCASEOK <3>: Environment variables.
                                                             (line  132)
* variabile d'ambiente, PYTHONCASEOK <4>: Funzioni Incorporate.
                                                             (line 2359)
* variabile d'ambiente, PYTHONCOERCECLOCALE: PEP 538 Legacy C Locale Coercion.
                                                             (line   13)
* variabile d'ambiente, PYTHONCOERCECLOCALE <1>: Environment variables.
                                                             (line  371)
* variabile d'ambiente, PYTHONCOERCECLOCALE <2>: General Options.
                                                             (line   88)
* variabile d'ambiente, PYTHONCOERCECLOCALE <3>: Python UTF-8 Mode.
                                                             (line   57)
* variabile d'ambiente, PYTHONCOERCECLOCALE <4>: Python Configuration.
                                                             (line   15)
* variabile d'ambiente, PYTHONDEBUG:     Miscellaneous options.
                                                             (line   37)
* variabile d'ambiente, PYTHONDEBUG <1>: Environment variables.
                                                             (line   94)
* variabile d'ambiente, PYTHONDEBUG <2>: Python Debug Build. (line   20)
* variabile d'ambiente, PYTHONDEBUG <3>: Global configuration variables.
                                                             (line   38)
* variabile d'ambiente, PYTHONDEBUG <4>: PyConfig.           (line  693)
* variabile d'ambiente, PYTHONDEVMODE:   Python Development Mode -X dev.
                                                             (line    6)
* variabile d'ambiente, PYTHONDEVMODE <1>: Miscellaneous options.
                                                             (line  316)
* variabile d'ambiente, PYTHONDEVMODE <2>: Environment variables.
                                                             (line  427)
* variabile d'ambiente, PYTHONDEVMODE <3>: Python Development Mode.
                                                             (line   14)
* variabile d'ambiente, PYTHONDEVMODE <4>: PyConfig.         (line  296)
* variabile d'ambiente, PYTHONDONTWRITEBYTECODE: Interpreter Changes<2>.
                                                             (line   16)
* variabile d'ambiente, PYTHONDONTWRITEBYTECODE <1>: New and Improved Modules<2>.
                                                             (line  626)
* variabile d'ambiente, PYTHONDONTWRITEBYTECODE <2>: Miscellaneous options.
                                                             (line   19)
* variabile d'ambiente, PYTHONDONTWRITEBYTECODE <3>: Environment variables.
                                                             (line  137)
* variabile d'ambiente, PYTHONDONTWRITEBYTECODE <4>: sys — System-specific parameters and functions.
                                                             (line  340)
* variabile d'ambiente, PYTHONDONTWRITEBYTECODE <5>: Global configuration variables.
                                                             (line   52)
* variabile d'ambiente, PYTHONDONTWRITEBYTECODE <6>: PyConfig.
                                                             (line 1007)
* variabile d'ambiente, PYTHONDONTWRITEBYTECODE <7>: How do I create a pyc file?.
                                                             (line   21)
* variabile d'ambiente, PYTHONDUMPREFS:  Debug build uses the same ABI as release build.
                                                             (line   15)
* variabile d'ambiente, PYTHONDUMPREFS <1>: Build<59>.       (line   54)
* variabile d'ambiente, PYTHONDUMPREFS <2>: Debug-mode variables.
                                                             (line    6)
* variabile d'ambiente, PYTHONDUMPREFS <3>: Debug options.   (line   22)
* variabile d'ambiente, PYTHONDUMPREFS <4>: Debug options.   (line   24)
* variabile d'ambiente, PYTHONDUMPREFS <5>: PyConfig.        (line  307)
* variabile d'ambiente, PYTHONDUMPREFSFILE: Core and Builtins<108>.
                                                             (line   16)
* variabile d'ambiente, PYTHONDUMPREFSFILE <1>: Debug-mode variables.
                                                             (line   14)
* variabile d'ambiente, PYTHONDUMPREFSFILE <2>: PyConfig.    (line  319)
* variabile d'ambiente, PYTHONEXECUTABLE: Environment variables.
                                                             (line  219)
* variabile d'ambiente, PYTHONEXECUTABLE <1>: PyConfig.      (line  728)
* variabile d'ambiente, PYTHONFAULTHANDLER: faulthandler<5>. (line   12)
* variabile d'ambiente, PYTHONFAULTHANDLER <1>: Miscellaneous options.
                                                             (line  268)
* variabile d'ambiente, PYTHONFAULTHANDLER <2>: Environment variables.
                                                             (line  247)
* variabile d'ambiente, PYTHONFAULTHANDLER <3>: Effects of the Python Development Mode.
                                                             (line   59)
* variabile d'ambiente, PYTHONFAULTHANDLER <4>: faulthandler — Dump the Python traceback.
                                                             (line   15)
* variabile d'ambiente, PYTHONFAULTHANDLER <5>: PyConfig.    (line  356)
* variabile d'ambiente, PYTHONHASHSEED:  Builtin functions and types.
                                                             (line   17)
* variabile d'ambiente, PYTHONHASHSEED <1>: Porting Python code.
                                                             (line    6)
* variabile d'ambiente, PYTHONHASHSEED <2>: Core and Builtins<165>.
                                                             (line   30)
* variabile d'ambiente, PYTHONHASHSEED <3>: Miscellaneous options.
                                                             (line  130)
* variabile d'ambiente, PYTHONHASHSEED <4>: Miscellaneous options.
                                                             (line  147)
* variabile d'ambiente, PYTHONHASHSEED <5>: Environment variables.
                                                             (line  152)
* variabile d'ambiente, PYTHONHASHSEED <6>: Environment variables.
                                                             (line  157)
* variabile d'ambiente, PYTHONHASHSEED <7>: Basic customization.
                                                             (line  317)
* variabile d'ambiente, PYTHONHASHSEED <8>: Global configuration variables.
                                                             (line   77)
* variabile d'ambiente, PYTHONHASHSEED <9>: Global configuration variables.
                                                             (line   80)
* variabile d'ambiente, PYTHONHASHSEED <10>: PyConfig.       (line  436)
* variabile d'ambiente, PYTHONHOME:      Pending removal in Python 3 15<2>.
                                                             (line   58)
* variabile d'ambiente, PYTHONHOME <1>:  Deprecated C APIs<2>.
                                                             (line   26)
* variabile d'ambiente, PYTHONHOME <2>:  Pending removal in Python 3 15<4>.
                                                             (line   58)
* variabile d'ambiente, PYTHONHOME <3>:  Pending removal in Python 3 15<6>.
                                                             (line   58)
* variabile d'ambiente, PYTHONHOME <4>:  Summary – Release highlights<6>.
                                                             (line  107)
* variabile d'ambiente, PYTHONHOME <5>:  Miscellaneous options.
                                                             (line   46)
* variabile d'ambiente, PYTHONHOME <6>:  Environment variables.
                                                             (line   11)
* variabile d'ambiente, PYTHONHOME <7>:  Environment variables.
                                                             (line   19)
* variabile d'ambiente, PYTHONHOME <8>:  Environment variables.
                                                             (line   21)
* variabile d'ambiente, PYTHONHOME <9>:  Environment variables.
                                                             (line   38)
* variabile d'ambiente, PYTHONHOME <10>: Finding modules.    (line   29)
* variabile d'ambiente, PYTHONHOME <11>: Finding modules.    (line   47)
* variabile d'ambiente, PYTHONHOME <12>: Finding modules.    (line   81)
* variabile d'ambiente, PYTHONHOME <13>: Adding Python to an iOS project.
                                                             (line   87)
* variabile d'ambiente, PYTHONHOME <14>: test support script_helper — Utilities for the Python execution tests.
                                                             (line   25)
* variabile d'ambiente, PYTHONHOME <15>: The initialization of the sys path module search path.
                                                             (line   30)
* variabile d'ambiente, PYTHONHOME <16>: The initialization of the sys path module search path.
                                                             (line   56)
* variabile d'ambiente, PYTHONHOME <17>: Virtual Environments.
                                                             (line   19)
* variabile d'ambiente, PYTHONHOME <18>: Embedding Python<2>.
                                                             (line   38)
* variabile d'ambiente, PYTHONHOME <19>: Embedding Python<2>.
                                                             (line   44)
* variabile d'ambiente, PYTHONHOME <20>: Global configuration variables.
                                                             (line   92)
* variabile d'ambiente, PYTHONHOME <21>: Process-wide parameters.
                                                             (line  302)
* variabile d'ambiente, PYTHONHOME <22>: Process-wide parameters.
                                                             (line  318)
* variabile d'ambiente, PYTHONHOME <23>: Process-wide parameters.
                                                             (line  327)
* variabile d'ambiente, PYTHONHOME <24>: PyConfig.           (line  444)
* variabile d'ambiente, PYTHONHOME <25>: PyConfig.           (line  446)
* variabile d'ambiente, PYTHONHOME <26>: Pending removal in Python 3 15<8>.
                                                             (line   58)
* variabile d'ambiente, PYTHONINSPECT:   Other Changes and Fixes<2>.
                                                             (line   13)
* variabile d'ambiente, PYTHONINSPECT <1>: Core and Builtins.
                                                             (line   57)
* variabile d'ambiente, PYTHONINSPECT <2>: Miscellaneous options.
                                                             (line   68)
* variabile d'ambiente, PYTHONINSPECT <3>: Environment variables.
                                                             (line  103)
* variabile d'ambiente, PYTHONINSPECT <4>: Global configuration variables.
                                                             (line  109)
* variabile d'ambiente, PYTHONINSPECT <5>: PyConfig.         (line  476)
* variabile d'ambiente, PYTHONINTMAXSTRDIGITS: Core and Builtins<74>.
                                                             (line   74)
* variabile d'ambiente, PYTHONINTMAXSTRDIGITS <1>: Miscellaneous options.
                                                             (line  290)
* variabile d'ambiente, PYTHONINTMAXSTRDIGITS <2>: Environment variables.
                                                             (line  170)
* variabile d'ambiente, PYTHONINTMAXSTRDIGITS <3>: Configurazione del limite.
                                                             (line   10)
* variabile d'ambiente, PYTHONINTMAXSTRDIGITS <4>: Configurazione del limite.
                                                             (line   17)
* variabile d'ambiente, PYTHONINTMAXSTRDIGITS <5>: sys — System-specific parameters and functions.
                                                             (line 1215)
* variabile d'ambiente, PYTHONINTMAXSTRDIGITS <6>: PyConfig. (line  507)
* variabile d'ambiente, PYTHONIOENCODING: Other Improvements<2>.
                                                             (line   75)
* variabile d'ambiente, PYTHONIOENCODING <1>: Interpreter Changes<2>.
                                                             (line   23)
* variabile d'ambiente, PYTHONIOENCODING <2>: Environment variables.
                                                             (line  178)
* variabile d'ambiente, PYTHONIOENCODING <3>: Environment variables.
                                                             (line  408)
* variabile d'ambiente, PYTHONIOENCODING <4>: Python UTF-8 Mode.
                                                             (line   29)
* variabile d'ambiente, PYTHONIOENCODING <5>: sys — System-specific parameters and functions.
                                                             (line 2027)
* variabile d'ambiente, PYTHONIOENCODING <6>: PyConfig.      (line  862)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING: Pending removal in Python 3 16.
                                                             (line  102)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <1>: New Deprecations.
                                                             (line  131)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <2>: Pending removal in Python 3 16<3>.
                                                             (line  102)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <3>: Pending removal in Python 3 16<5>.
                                                             (line  102)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <4>: PEP 529 Change Windows filesystem encoding to UTF-8.
                                                             (line   18)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <5>: Windows<18>.
                                                             (line   37)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <6>: Environment variables.
                                                             (line  344)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <7>: sys — System-specific parameters and functions.
                                                             (line 1967)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <8>: sys — System-specific parameters and functions.
                                                             (line 1978)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <9>: sys — System-specific parameters and functions.
                                                             (line 1984)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <10>: Global configuration variables.
                                                             (line  151)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <11>: PyPreConfig.
                                                             (line  123)
* variabile d'ambiente, PYTHONLEGACYWINDOWSFSENCODING <12>: Pending removal in Python 3 16<7>.
                                                             (line  102)
* variabile d'ambiente, PYTHONLEGACYWINDOWSSTDIO: PEP 528 Change Windows console encoding to UTF-8.
                                                             (line   12)
* variabile d'ambiente, PYTHONLEGACYWINDOWSSTDIO <1>: Environment variables.
                                                             (line  193)
* variabile d'ambiente, PYTHONLEGACYWINDOWSSTDIO <2>: Environment variables.
                                                             (line  358)
* variabile d'ambiente, PYTHONLEGACYWINDOWSSTDIO <3>: sys — System-specific parameters and functions.
                                                             (line 2031)
* variabile d'ambiente, PYTHONLEGACYWINDOWSSTDIO <4>: Global configuration variables.
                                                             (line  169)
* variabile d'ambiente, PYTHONLEGACYWINDOWSSTDIO <5>: PyConfig.
                                                             (line  560)
* variabile d'ambiente, PYTHONMALLOC:    PYTHONMALLOC environment variable.
                                                             (line    6)
* variabile d'ambiente, PYTHONMALLOC <1>: Changes in the C API<7>.
                                                             (line    9)
* variabile d'ambiente, PYTHONMALLOC <2>: Core and Builtins<185>.
                                                             (line   90)
* variabile d'ambiente, PYTHONMALLOC <3>: Environment variables.
                                                             (line  290)
* variabile d'ambiente, PYTHONMALLOC <4>: Environment variables.
                                                             (line  335)
* variabile d'ambiente, PYTHONMALLOC <5>: Performance options.
                                                             (line  120)
* variabile d'ambiente, PYTHONMALLOC <6>: Performance options.
                                                             (line  127)
* variabile d'ambiente, PYTHONMALLOC <7>: Effects of the Python Development Mode.
                                                             (line   46)
* variabile d'ambiente, PYTHONMALLOC <8>: Effects of the Python Development Mode.
                                                             (line   50)
* variabile d'ambiente, PYTHONMALLOC <9>: Overview<4>.       (line   75)
* variabile d'ambiente, PYTHONMALLOC <10>: Default Memory Allocators.
                                                             (line   26)
* variabile d'ambiente, PYTHONMALLOC <11>: Debug hooks on the Python memory allocators.
                                                             (line   11)
* variabile d'ambiente, PYTHONMALLOC <12>: The pymalloc allocator.
                                                             (line   27)
* variabile d'ambiente, PYTHONMALLOCSTATS: Core and Builtins<185>.
                                                             (line   96)
* variabile d'ambiente, PYTHONMALLOCSTATS <1>: Environment variables.
                                                             (line  329)
* variabile d'ambiente, PYTHONMALLOCSTATS <2>: PyConfig.     (line  576)
* variabile d'ambiente, PYTHONMALLOCSTATS <3>: Overview<4>.  (line   78)
* variabile d'ambiente, PYTHONNODEBUGRANGES: PEP 657 Fine-grained error locations in tracebacks.
                                                             (line   63)
* variabile d'ambiente, PYTHONNODEBUGRANGES <1>: Miscellaneous options.
                                                             (line  345)
* variabile d'ambiente, PYTHONNODEBUGRANGES <2>: Environment variables.
                                                             (line  457)
* variabile d'ambiente, PYTHONNODEBUGRANGES <3>: Methods on code objects.
                                                             (line   40)
* variabile d'ambiente, PYTHONNODEBUGRANGES <4>: PyConfig.   (line  249)
* variabile d'ambiente, PYTHONNOUSERSITE: PEP 370 Per-user site-packages Directory.
                                                             (line   30)
* variabile d'ambiente, PYTHONNOUSERSITE <1>: Miscellaneous options.
                                                             (line  159)
* variabile d'ambiente, PYTHONNOUSERSITE <2>: Environment variables.
                                                             (line  197)
* variabile d'ambiente, PYTHONNOUSERSITE <3>: Module contents<5>.
                                                             (line   15)
* variabile d'ambiente, PYTHONNOUSERSITE <4>: Global configuration variables.
                                                             (line  203)
* variabile d'ambiente, PYTHONNOUSERSITE <5>: PyConfig.      (line  960)
* variabile d'ambiente, PYTHONOPTIMIZE:  Miscellaneous options.
                                                             (line   88)
* variabile d'ambiente, PYTHONOPTIMIZE <1>: Environment variables.
                                                             (line   75)
* variabile d'ambiente, PYTHONOPTIMIZE <2>: Global configuration variables.
                                                             (line  214)
* variabile d'ambiente, PYTHONOPTIMIZE <3>: PyConfig.        (line  643)
* variabile d'ambiente, PYTHONPATH:      Changes in “python” Command Behavior<2>.
                                                             (line    8)
* variabile d'ambiente, PYTHONPATH <1>:  Changes in “python” Command Behavior<2>.
                                                             (line    9)
* variabile d'ambiente, PYTHONPATH <2>:  Il percorso di ricerca del modulo.
                                                             (line   16)
* variabile d'ambiente, PYTHONPATH <3>:  Moduli Standard.    (line   34)
* variabile d'ambiente, PYTHONPATH <4>:  Moduli Standard.    (line   35)
* variabile d'ambiente, PYTHONPATH <5>:  Miscellaneous options.
                                                             (line   45)
* variabile d'ambiente, PYTHONPATH <6>:  Environment variables.
                                                             (line   24)
* variabile d'ambiente, PYTHONPATH <7>:  Environment variables.
                                                             (line   32)
* variabile d'ambiente, PYTHONPATH <8>:  Environment variables.
                                                             (line   39)
* variabile d'ambiente, PYTHONPATH <9>:  Environment variables.
                                                             (line   42)
* variabile d'ambiente, PYTHONPATH <10>: Finding modules.    (line   15)
* variabile d'ambiente, PYTHONPATH <11>: Finding modules.    (line   38)
* variabile d'ambiente, PYTHONPATH <12>: Finding modules.    (line   81)
* variabile d'ambiente, PYTHONPATH <13>: Adding Python to an iOS project.
                                                             (line   90)
* variabile d'ambiente, PYTHONPATH <14>: Adding Python to an iOS project.
                                                             (line  116)
* variabile d'ambiente, PYTHONPATH <15>: Adding Python to an iOS project.
                                                             (line  122)
* variabile d'ambiente, PYTHONPATH <16>: Path entry finders. (line   23)
* variabile d'ambiente, PYTHONPATH <17>: test support script_helper — Utilities for the Python execution tests.
                                                             (line   26)
* variabile d'ambiente, PYTHONPATH <18>: sys — System-specific parameters and functions.
                                                             (line 1453)
* variabile d'ambiente, PYTHONPATH <19>: sys — System-specific parameters and functions.
                                                             (line 1458)
* variabile d'ambiente, PYTHONPATH <20>: The initialization of the sys path module search path.
                                                             (line   14)
* variabile d'ambiente, PYTHONPATH <21>: The initialization of the sys path module search path.
                                                             (line   18)
* variabile d'ambiente, PYTHONPATH <22>: Embedding Python<2>.
                                                             (line   39)
* variabile d'ambiente, PYTHONPATH <23>: Embedding Python<2>.
                                                             (line   45)
* variabile d'ambiente, PYTHONPATH <24>: Global configuration variables.
                                                             (line   91)
* variabile d'ambiente, PYTHONPATH <25>: PyConfig.           (line  609)
* variabile d'ambiente, PYTHONPERFSUPPORT: Altre modifiche al Linguaggio.
                                                             (line   92)
* variabile d'ambiente, PYTHONPERFSUPPORT <1>: Miscellaneous options.
                                                             (line  365)
* variabile d'ambiente, PYTHONPERFSUPPORT <2>: Environment variables.
                                                             (line  468)
* variabile d'ambiente, PYTHONPERFSUPPORT <3>: PyConfig.     (line  904)
* variabile d'ambiente, PYTHONPERFSUPPORT <4>: How to enable perf profiling support.
                                                             (line    7)
* variabile d'ambiente, PYTHONPLATLIBDIR: Core and Builtins<144>.
                                                             (line   47)
* variabile d'ambiente, PYTHONPLATLIBDIR <1>: Environment variables.
                                                             (line   54)
* variabile d'ambiente, PYTHONPLATLIBDIR <2>: The initialization of the sys path module search path.
                                                             (line   51)
* variabile d'ambiente, PYTHONPLATLIBDIR <3>: PyConfig.      (line  588)
* variabile d'ambiente, PYTHONPROFILEIMPORTTIME: Other Language Changes<6>.
                                                             (line   47)
* variabile d'ambiente, PYTHONPROFILEIMPORTTIME <1>: Core and Builtins<167>.
                                                             (line   66)
* variabile d'ambiente, PYTHONPROFILEIMPORTTIME <2>: Miscellaneous options.
                                                             (line  306)
* variabile d'ambiente, PYTHONPROFILEIMPORTTIME <3>: Environment variables.
                                                             (line  271)
* variabile d'ambiente, PYTHONPROFILEIMPORTTIME <4>: PyConfig.
                                                             (line  458)
* variabile d'ambiente, PYTHONPYCACHEPREFIX: Parallel filesystem cache for compiled bytecode files.
                                                             (line    6)
* variabile d'ambiente, PYTHONPYCACHEPREFIX <1>: Core and Builtins<158>.
                                                             (line  402)
* variabile d'ambiente, PYTHONPYCACHEPREFIX <2>: Miscellaneous options.
                                                             (line  329)
* variabile d'ambiente, PYTHONPYCACHEPREFIX <3>: Environment variables.
                                                             (line  143)
* variabile d'ambiente, PYTHONPYCACHEPREFIX <4>: sys — System-specific parameters and functions.
                                                             (line  386)
* variabile d'ambiente, PYTHONPYCACHEPREFIX <5>: PyConfig.   (line  750)
* variabile d'ambiente, PYTHONREGRTEST_UNICODE_GUARD: Tests<28>.
                                                             (line   13)
* variabile d'ambiente, PYTHONSAFEPATH:  Summary – Release highlights<2>.
                                                             (line   27)
* variabile d'ambiente, PYTHONSAFEPATH <1>: Other Language Changes<2>.
                                                             (line   37)
* variabile d'ambiente, PYTHONSAFEPATH <2>: Security<28>.    (line    6)
* variabile d'ambiente, PYTHONSAFEPATH <3>: Miscellaneous options.
                                                             (line  116)
* variabile d'ambiente, PYTHONSAFEPATH <4>: Environment variables.
                                                             (line   46)
* variabile d'ambiente, PYTHONSAFEPATH <5>: sys — System-specific parameters and functions.
                                                             (line 1470)
* variabile d'ambiente, PYTHONSAFEPATH <6>: Security Considerations<3>.
                                                             (line   47)
* variabile d'ambiente, PYTHONSAFEPATH <7>: PyConfig.        (line  166)
* variabile d'ambiente, PYTHONSTARTUP:   Default interactive shell.
                                                             (line   16)
* variabile d'ambiente, PYTHONSTARTUP <1>: sys<12>.          (line   17)
* variabile d'ambiente, PYTHONSTARTUP <2>: sys<12>.          (line   21)
* variabile d'ambiente, PYTHONSTARTUP <3>: Library.          (line  141)
* variabile d'ambiente, PYTHONSTARTUP <4>: Core and Builtins<10>.
                                                             (line   41)
* variabile d'ambiente, PYTHONSTARTUP <5>: IDLE<37>.         (line  176)
* variabile d'ambiente, PYTHONSTARTUP <6>: IDLE<41>.         (line    9)
* variabile d'ambiente, PYTHONSTARTUP <7>: IDLE<47>.         (line    9)
* variabile d'ambiente, PYTHONSTARTUP <8>: Il File di Avvio Interattivo.
                                                             (line    8)
* variabile d'ambiente, PYTHONSTARTUP <9>: Miscellaneous options.
                                                             (line   64)
* variabile d'ambiente, PYTHONSTARTUP <10>: Environment variables.
                                                             (line   61)
* variabile d'ambiente, PYTHONSTARTUP <11>: Environment variables.
                                                             (line  118)
* variabile d'ambiente, PYTHONSTARTUP <12>: Example.         (line   10)
* variabile d'ambiente, PYTHONSTARTUP <13>: asyncio — Asynchronous I/O.
                                                             (line   91)
* variabile d'ambiente, PYTHONSTARTUP <14>: Startup and Code Execution.
                                                             (line    7)
* variabile d'ambiente, PYTHONSTARTUP <15>: Command-line usage<5>.
                                                             (line   42)
* variabile d'ambiente, PYTHONSTARTUP <16>: sys — System-specific parameters and functions.
                                                             (line 1228)
* variabile d'ambiente, PYTHONSTARTUP <17>: Readline configuration.
                                                             (line   12)
* variabile d'ambiente, PYTHONTRACEMALLOC: Miscellaneous options.
                                                             (line  285)
* variabile d'ambiente, PYTHONTRACEMALLOC <1>: Environment variables.
                                                             (line  258)
* variabile d'ambiente, PYTHONTRACEMALLOC <2>: tracemalloc — Trace memory allocations.
                                                             (line   25)
* variabile d'ambiente, PYTHONTRACEMALLOC <3>: tracemalloc — Trace memory allocations.
                                                             (line   32)
* variabile d'ambiente, PYTHONTRACEMALLOC <4>: Functions<10>.
                                                             (line   90)
* variabile d'ambiente, PYTHONTRACEMALLOC <5>: PyConfig.     (line  890)
* variabile d'ambiente, PYTHONTZPATH:    Environment configuration.
                                                             (line   11)
* variabile d'ambiente, PYTHONTZPATH <1>: Exceptions and warnings.
                                                             (line   14)
* variabile d'ambiente, PYTHONUNBUFFERED: Core and Builtins<151>.
                                                             (line  107)
* variabile d'ambiente, PYTHONUNBUFFERED <1>: Miscellaneous options.
                                                             (line  179)
* variabile d'ambiente, PYTHONUNBUFFERED <2>: Environment variables.
                                                             (line  121)
* variabile d'ambiente, PYTHONUNBUFFERED <3>: sys — System-specific parameters and functions.
                                                             (line 2038)
* variabile d'ambiente, PYTHONUNBUFFERED <4>: Global configuration variables.
                                                             (line  242)
* variabile d'ambiente, PYTHONUNBUFFERED <5>: PyConfig.      (line  213)
* variabile d'ambiente, PYTHONUOPS:      Core and Builtins<58>.
                                                             (line   27)
* variabile d'ambiente, PYTHONUOPS <1>:  Core and Builtins<58>.
                                                             (line  179)
* variabile d'ambiente, PYTHONUOPS <2>:  Core and Builtins<58>.
                                                             (line  258)
* variabile d'ambiente, PYTHONUOPS <3>:  Core and Builtins<58>.
                                                             (line  317)
* variabile d'ambiente, PYTHONUOPS <4>:  Core and Builtins<58>.
                                                             (line  382)
* variabile d'ambiente, PYTHONUSERBASE:  PEP 370 Per-user site-packages Directory.
                                                             (line   23)
* variabile d'ambiente, PYTHONUSERBASE <1>: Environment variables.
                                                             (line  207)
* variabile d'ambiente, PYTHONUSERBASE <2>: Module contents<5>.
                                                             (line   40)
* variabile d'ambiente, PYTHONUSERBASE <3>: Module contents<5>.
                                                             (line   68)
* variabile d'ambiente, PYTHONUSERSITE:  test support script_helper — Utilities for the Python execution tests.
                                                             (line   26)
* variabile d'ambiente, PYTHONUTF8:      PEP 540 Forced UTF-8 Runtime Mode.
                                                             (line    6)
* variabile d'ambiente, PYTHONUTF8 <1>:  Miscellaneous options.
                                                             (line  323)
* variabile d'ambiente, PYTHONUTF8 <2>:  Environment variables.
                                                             (line  418)
* variabile d'ambiente, PYTHONUTF8 <3>:  Environment variables.
                                                             (line  436)
* variabile d'ambiente, PYTHONUTF8 <4>:  UTF-8 mode.         (line   18)
* variabile d'ambiente, PYTHONUTF8 <5>:  Python UTF-8 Mode.  (line   52)
* variabile d'ambiente, PYTHONUTF8 <6>:  Python UTF-8 Mode.  (line   54)
* variabile d'ambiente, PYTHONUTF8 <7>:  sys — System-specific parameters and functions.
                                                             (line 2029)
* variabile d'ambiente, PYTHONUTF8 <8>:  PyPreConfig.        (line  152)
* variabile d'ambiente, PYTHONUTF8 <9>:  Python Configuration.
                                                             (line   14)
* variabile d'ambiente, PYTHONVERBOSE:   Miscellaneous options.
                                                             (line  195)
* variabile d'ambiente, PYTHONVERBOSE <1>: Environment variables.
                                                             (line  126)
* variabile d'ambiente, PYTHONVERBOSE <2>: Global configuration variables.
                                                             (line  259)
* variabile d'ambiente, PYTHONVERBOSE <3>: PyConfig.         (line  977)
* variabile d'ambiente, PYTHONWARNDEFAULTENCODING: Optional EncodingWarning and encoding="locale" option.
                                                             (line   19)
* variabile d'ambiente, PYTHONWARNDEFAULTENCODING <1>: Library<120>.
                                                             (line   45)
* variabile d'ambiente, PYTHONWARNDEFAULTENCODING <2>: Miscellaneous options.
                                                             (line  335)
* variabile d'ambiente, PYTHONWARNDEFAULTENCODING <3>: Environment variables.
                                                             (line  447)
* variabile d'ambiente, PYTHONWARNDEFAULTENCODING <4>: Opt-in EncodingWarning.
                                                             (line    9)
* variabile d'ambiente, PYTHONWARNINGS:  warnings<3>.        (line   21)
* variabile d'ambiente, PYTHONWARNINGS <1>: Other Language Changes<11>.
                                                             (line  160)
* variabile d'ambiente, PYTHONWARNINGS <2>: Changes to the Handling of Deprecation Warnings.
                                                             (line   25)
* variabile d'ambiente, PYTHONWARNINGS <3>: Interpreter Changes.
                                                             (line    6)
* variabile d'ambiente, PYTHONWARNINGS <4>: Documentation<27>.
                                                             (line   67)
* variabile d'ambiente, PYTHONWARNINGS <5>: Miscellaneous options.
                                                             (line  249)
* variabile d'ambiente, PYTHONWARNINGS <6>: Environment variables.
                                                             (line  225)
* variabile d'ambiente, PYTHONWARNINGS <7>: Effects of the Python Development Mode.
                                                             (line   30)
* variabile d'ambiente, PYTHONWARNINGS <8>: The Warnings Filter.
                                                             (line   49)
* variabile d'ambiente, PYTHONWARNINGS <9>: The Warnings Filter.
                                                             (line   59)
* variabile d'ambiente, PYTHONWARNINGS <10>: Describing Warning Filters.
                                                             (line    7)
* variabile d'ambiente, PYTHONWARNINGS <11>: Describing Warning Filters.
                                                             (line   21)
* variabile d'ambiente, PYTHONWARNINGS <12>: Default Warning Filter.
                                                             (line    7)
* variabile d'ambiente, PYTHONWARNINGS <13>: PyConfig.       (line  996)
* variabile d'ambiente, SOURCE_DATE_EPOCH: zipfile.          (line   11)
* variabile d'ambiente, SOURCE_DATE_EPOCH <1>: py_compile<3>.
                                                             (line    7)
* variabile d'ambiente, SOURCE_DATE_EPOCH <2>: Library<161>. (line  452)
* variabile d'ambiente, SOURCE_DATE_EPOCH <3>: Build<67>.    (line   15)
* variabile d'ambiente, SOURCE_DATE_EPOCH <4>: py_compile — Compile Python source files.
                                                             (line   66)
* variabile d'ambiente, SOURCE_DATE_EPOCH <5>: py_compile — Compile Python source files.
                                                             (line   82)
* variabile d'ambiente, SOURCE_DATE_EPOCH <6>: py_compile — Compile Python source files.
                                                             (line   86)
* variabile d'ambiente, SOURCE_DATE_EPOCH <7>: Command-line use.
                                                             (line   97)
* variabile d'ambiente, SSLKEYLOGFILE:   Context creation.   (line   34)
* variabile d'ambiente, SSLKEYLOGFILE <1>: Context creation. (line   83)
* variabile d'ambiente, TEMP:            tempfile — Generate temporary files and directories.
                                                             (line  333)
* variabile d'ambiente, TERM:            Functions<5>.       (line  501)
* variabile d'ambiente, TERM <1>:        Functions<5>.       (line  528)
* variabile d'ambiente, TMP:             tempfile — Generate temporary files and directories.
                                                             (line  335)
* variabile d'ambiente, TMPDIR:          Library<22>.        (line   79)
* variabile d'ambiente, TMPDIR <1>:      Tests<27>.          (line   68)
* variabile d'ambiente, TMPDIR <2>:      tempfile — Generate temporary files and directories.
                                                             (line  331)
* variabile d'ambiente, TZ:              Functions<4>.       (line  642)
* variabile d'ambiente, TZ <1>:          Functions<4>.       (line  643)
* variabile d'ambiente, TZ <2>:          Functions<4>.       (line  651)
* variabile d'ambiente, TZ <3>:          Functions<4>.       (line  656)
* variabile d'ambiente, TZ <4>:          Functions<4>.       (line  658)
* variabile d'ambiente, TZ <5>:          Functions<4>.       (line  719)
* variabile d'ambiente, USER:            getpass — Portable password input.
                                                             (line   59)
* variabile d'ambiente, USERNAME:        os path — Common pathname manipulations.
                                                             (line  150)
* variabile d'ambiente, USERNAME <1>:    Process Parameters. (line  262)
* variabile d'ambiente, USERNAME <2>:    getpass — Portable password input.
                                                             (line   60)
* variabile d'ambiente, USERPROFILE:     os path<5>.         (line   14)
* variabile d'ambiente, USERPROFILE <1>: Changes in the Python API<5>.
                                                             (line  117)
* variabile d'ambiente, USERPROFILE <2>: Windows<47>.        (line   15)
* variabile d'ambiente, USERPROFILE <3>: os path — Common pathname manipulations.
                                                             (line  147)
* variable annotation:                   Glossary.           (line 1822)
* variance (statistics.NormalDist attributo): NormalDist objects.
                                                             (line   40)
* variance() (nel modulo statistics):    Function details.   (line  444)
* variant (uuid.UUID attributo):         uuid — UUID objects according to RFC 9562.
                                                             (line  154)
* VBAR (nel modulo token):               token — Constants used with Python parse trees.
                                                             (line  245)
* vbar (tkinter.scrolledtext.ScrolledText attributo): tkinter scrolledtext — Scrolled Text Widget.
                                                             (line   30)
* VBAREQUAL (nel modulo token):          token — Constants used with Python parse trees.
                                                             (line  317)
* VC_ASSEMBLY_PUBLICKEYTOKEN (nel modulo msvcrt): Other Functions.
                                                             (line   93)
* Vec2D (classe in turtle):              Public classes.     (line   86)
* vectorcallfunc (C type):               The Vectorcall Protocol.
                                                             (line   41)
* venv command line option; -clear:      Creating virtual environments.
                                                             (line   64)
* venv command line option; -copies:     Creating virtual environments.
                                                             (line   59)
* venv command line option; -prompt:     Creating virtual environments.
                                                             (line   79)
* venv command line option; -symlinks:   Creating virtual environments.
                                                             (line   54)
* venv command line option; -system-site-packages: Creating virtual environments.
                                                             (line   49)
* venv command line option; -upgrade:    Creating virtual environments.
                                                             (line   69)
* venv command line option; -upgrade-deps: Creating virtual environments.
                                                             (line   83)
* venv command line option; -without-pip: Creating virtual environments.
                                                             (line   74)
* venv command line option; -without-scm-ignore-files: Creating virtual environments.
                                                             (line   87)
* venv command line option; ENV_DIR:     Creating virtual environments.
                                                             (line   44)
* VERBOSE (nel modulo re):               Flags.              (line  127)
* verbose (nel modulo tabnanny):         tabnanny — Detection of ambiguous indentation.
                                                             (line   26)
* verbose (nel modulo test.support):     test support — Utilities for the Python test suite.
                                                             (line   30)
* verbose (sys.flags attributo):         sys — System-specific parameters and functions.
                                                             (line  565)
* VERIFY_ALLOW_PROXY_CERTS (nel modulo ssl): Constants<9>.   (line   98)
* verify_client_post_handshake() (ssl.SSLSocket metodo): SSL Sockets.
                                                             (line  307)
* verify_code (ssl.SSLCertVerificationError attributo): Exceptions<18>.
                                                             (line   86)
* VERIFY_CRL_CHECK_CHAIN (nel modulo ssl): Constants<9>.     (line   84)
* VERIFY_CRL_CHECK_LEAF (nel modulo ssl): Constants<9>.      (line   73)
* VERIFY_DEFAULT (nel modulo ssl):       Constants<9>.       (line   65)
* verify_flags (ssl.SSLContext attributo): SSL Contexts.     (line  633)
* verify_generated_headers (email.policy.Policy attributo): email policy Policy Objects.
                                                             (line  204)
* verify_message (ssl.SSLCertVerificationError attributo): Exceptions<18>.
                                                             (line   90)
* verify_mode (ssl.SSLContext attributo): SSL Contexts.      (line  648)
* verify_request() (socketserver.BaseServer metodo): Server Objects<2>.
                                                             (line  179)
* VERIFY_X509_PARTIAL_CHAIN (nel modulo ssl): Constants<9>.  (line  114)
* VERIFY_X509_STRICT (nel modulo ssl):   Constants<9>.       (line   91)
* VERIFY_X509_TRUSTED_FIRST (nel modulo ssl): Constants<9>.  (line  105)
* verify() (nel modulo enum):            Utilities and Decorators.
                                                             (line   72)
* verify() (smtplib.SMTP metodo):        SMTP Objects.       (line   91)
* VerifyFlags (classe in ssl):           Constants<9>.       (line  125)
* VerifyMode (classe in ssl):            Constants<9>.       (line   59)
* verità;valore:                         Test del Valore di Verità.
                                                             (line    6)
* vero:                                  Test del Valore di Verità.
                                                             (line   10)
* Vero:                                  Test del Valore di Verità.
                                                             (line   26)
* Vero <1>:                              Tipo Booleano - bool.
                                                             (line    9)
* version (email.headerregistry.MIMEVersionHeader attributo): email headerregistry Custom Header Objects.
                                                             (line  242)
* version (http.client.HTTPResponse attributo): HTTPResponse Objects.
                                                             (line   46)
* version (http.cookiejar.Cookie attributo): Cookie Objects<2>.
                                                             (line   20)
* version (http.cookies.Morsel attributo): Morsel Objects.   (line   13)
* version (in module sys):               Process-wide parameters.
                                                             (line  171)
* version (in module sys) <1>:           Process-wide parameters.
                                                             (line  208)
* version (in module sys) <2>:           Process-wide parameters.
                                                             (line  219)
* version (ipaddress.IPv4Address attributo): Address objects.
                                                             (line   45)
* version (ipaddress.IPv4Network attributo): Network objects.
                                                             (line   63)
* version (ipaddress.IPv6Address attributo): Address objects.
                                                             (line  275)
* version (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  294)
* version (nel modulo curses):           Constants<6>.       (line   18)
* version (nel modulo marshal):          marshal — Internal Python object serialization.
                                                             (line  150)
* version (nel modulo sys):              sys — System-specific parameters and functions.
                                                             (line 2188)
* version (sys.thread_info attributo):   sys — System-specific parameters and functions.
                                                             (line 2124)
* version (uuid.UUID attributo):         uuid — UUID objects according to RFC 9562.
                                                             (line  161)
* version_info (nel modulo sys):         sys — System-specific parameters and functions.
                                                             (line 2205)
* version_string() (http.server.BaseHTTPRequestHandler metodo): http server — HTTP servers.
                                                             (line  361)
* version() (nel modulo ensurepip):      Module API.         (line    8)
* version() (nel modulo importlib.metadata): Distribution versions.
                                                             (line    6)
* version() (nel modulo platform):       Cross platform.     (line  138)
* version() (ssl.SSLSocket metodo):      SSL Sockets.        (line  329)
* vformat() (string.Formatter metodo):   Custom String Formatting.
                                                             (line   26)
* virtual environment:                   Glossary.           (line 1845)
* virtual machine:                       Glossary.           (line 1854)
* visit_Constant() (ast.NodeVisitor metodo): ast helpers.    (line  210)
* visit() (ast.NodeVisitor metodo):      ast helpers.        (line  194)
* visitproc (C type):                    Supporting Cyclic Garbage Collection.
                                                             (line  222)
* vline() (curses.window metodo):        Window Objects.     (line  597)
* voidcmd() (ftplib.FTP metodo):         FTP objects.        (line  166)
* volume (zipfile.ZipInfo attributo):    ZipInfo objects.    (line  134)
* vonmisesvariate() (nel modulo random): Real-valued distributions.
                                                             (line   93)
* VT (nel modulo curses.ascii):          curses ascii — Utilities for ASCII characters.
                                                             (line   58)
* W_OK (nel modulo os):                  Files and Directories.
                                                             (line  107)
* wait_closed() (asyncio.Server metodo): Server Objects.     (line  123)
* wait_closed() (asyncio.StreamWriter metodo): StreamWriter. (line  117)
* wait_for() (asyncio.Condition metodo): Condition.          (line  102)
* wait_for() (nel modulo asyncio):       Timeouts.           (line  118)
* wait_for() (threading.Condition metodo): Condition objects.
                                                             (line  136)
* wait_process() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  441)
* wait_threads_exit() (nel modulo test.support.threading_helper): test support threading_helper — Utilities for threading tests.
                                                             (line   41)
* wait_until_any_call_with() (unittest.mock.ThreadingMock metodo): The Mock Class.
                                                             (line  986)
* wait_until_called() (unittest.mock.ThreadingMock metodo): The Mock Class.
                                                             (line  971)
* wait() (asyncio.Barrier metodo):       Barrier.            (line   52)
* wait() (asyncio.Condition metodo):     Condition.          (line   85)
* wait() (asyncio.Event metodo):         Event.              (line   44)
* wait() (asyncio.subprocess.Process metodo): Interacting with Subprocesses.
                                                             (line   38)
* wait() (multiprocessing.pool.AsyncResult metodo): Process Pools.
                                                             (line  212)
* wait() (nel modulo asyncio):           Waiting Primitives. (line    6)
* wait() (nel modulo concurrent.futures): Module Functions.  (line    6)
* wait() (nel modulo multiprocessing.connection): Listeners and Clients.
                                                             (line  113)
* wait() (nel modulo os):                Process Management. (line  835)
* wait() (subprocess.Popen metodo):      Popen Objects.      (line   13)
* wait() (threading.Barrier metodo):     Barrier objects.    (line   43)
* wait() (threading.Condition metodo):   Condition objects.  (line  105)
* wait() (threading.Event metodo):       Event objects.      (line   43)
* wait3() (nel modulo os):               Process Management. (line  945)
* wait4() (nel modulo os):               Process Management. (line  959)
* waitid() (nel modulo os):              Process Management. (line  859)
* waitpid() (nel modulo os):             Process Management. (line  898)
* waitstatus_to_exitcode() (nel modulo os): Process Management.
                                                             (line 1077)
* walk_packages() (nel modulo pkgutil):  pkgutil — Package extension utility.
                                                             (line  108)
* walk_stack() (nel modulo traceback):   Module-Level Functions<2>.
                                                             (line  185)
* walk_tb() (nel modulo traceback):      Module-Level Functions<2>.
                                                             (line  199)
* walk() (email.message.EmailMessage metodo): email message Representing an email message.
                                                             (line  467)
* walk() (email.message.Message metodo): email message Message Representing an email message using the compat32 API.
                                                             (line  640)
* walk() (nel modulo ast):               ast helpers.        (line  177)
* walk() (nel modulo os):                Files and Directories.
                                                             (line 1652)
* walk() (pathlib.Path metodo):          Reading directories.
                                                             (line  111)
* walrus operator:                       Boolean operations. (line   38)
* walrus operator <1>:                   Glossary.           (line 1860)
* want (doctest.Example attributo):      Example Objects.    (line   23)
* warn_default_encoding (sys.flags attributo): sys — System-specific parameters and functions.
                                                             (line  591)
* warn_explicit() (nel modulo warnings): Available Functions.
                                                             (line   62)
* warn() (nel modulo warnings):          Available Functions.
                                                             (line    6)
* Warning:                               Warnings.           (line    9)
* Warning <1>:                           Exceptions<6>.      (line    8)
* WARNING (nel modulo logging):          Logging Levels.     (line   33)
* WARNING (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  198)
* warning() (logging.Logger metodo):     Logger Objects.     (line  295)
* warning() (nel modulo logging):        Module-Level Functions.
                                                             (line   70)
* warning() (xml.sax.handler.ErrorHandler metodo): ErrorHandler Objects.
                                                             (line   29)
* warnings:                              warnings — Warning control.
                                                             (line    8)
* WarningsRecorder (classe in test.support.warnings_helper): test support warnings_helper — Utilities for warnings tests.
                                                             (line  118)
* warnoptions (nel modulo sys):          sys — System-specific parameters and functions.
                                                             (line 2218)
* wasSuccessful() (unittest.TestResult metodo): Loading and running tests.
                                                             (line  320)
* WatchedFileHandler (classe in logging.handlers): WatchedFileHandler.
                                                             (line   24)
* Wave_read (classe in wave):            Wave_read Objects.  (line    6)
* Wave_write (classe in wave):           Wave_write Objects. (line    6)
* WCONTINUED (nel modulo os):            Process Management. (line  999)
* WCOREDUMP() (nel modulo os):           Process Management. (line 1117)
* WeakKeyDictionary (classe in weakref): weakref — Weak references.
                                                             (line  166)
* WeakMethod (classe in weakref):        weakref — Weak references.
                                                             (line  236)
* WeakSet (classe in weakref):           weakref — Weak references.
                                                             (line  231)
* WeakValueDictionary (classe in weakref): weakref — Weak references.
                                                             (line  214)
* webbrowser command line option; -n:    Command-line interface<6>.
                                                             (line   10)
* webbrowser command line option; -new-tab: Command-line interface<6>.
                                                             (line   14)
* webbrowser command line option; -new-window: Command-line interface<6>.
                                                             (line   10)
* webbrowser command line option; -t:    Command-line interface<6>.
                                                             (line   14)
* WEDNESDAY (nel modulo calendar):       calendar — General calendar-related functions.
                                                             (line  447)
* weekday (calendar.IllegalWeekdayError attributo): calendar — General calendar-related functions.
                                                             (line  532)
* weekday() (datetime.date metodo):      date Objects.       (line  261)
* weekday() (datetime.datetime metodo):  datetime Objects.   (line  637)
* weekday() (nel modulo calendar):       calendar — General calendar-related functions.
                                                             (line  376)
* weekheader() (nel modulo calendar):    calendar — General calendar-related functions.
                                                             (line  381)
* weibullvariate() (nel modulo random):  Real-valued distributions.
                                                             (line  105)
* WEXITED (nel modulo os):               Process Management. (line 1008)
* WEXITSTATUS() (nel modulo os):         Process Management. (line 1163)
* wfile (http.server.BaseHTTPRequestHandler attributo): http server — HTTP servers.
                                                             (line  170)
* wfile (socketserver.DatagramRequestHandler attributo): Request Handler Objects.
                                                             (line   68)
* whatis (pdb command):                  Debugger commands.  (line  292)
* when() (asyncio.Timeout metodo):       Timeouts.           (line   63)
* when() (asyncio.TimerHandle metodo):   Callback Handles.   (line   36)
* whence (concurrent.interpreters.Interpreter attributo): Interpreter objects.
                                                             (line   20)
* where (pdb command):                   Debugger commands.  (line   85)
* which() (nel modulo shutil):           Directory and files operations.
                                                             (line  439)
* whichdb() (nel modulo dbm):            dbm — Interfaces to Unix «databases».
                                                             (line   29)
* While (classe in ast):                 Control flow.       (line   77)
* whitespace (nel modulo string):        String constants.   (line   52)
* whitespace (shlex.shlex attributo):    shlex Objects.      (line  104)
* whitespace_split (shlex.shlex attributo): shlex Objects.   (line  128)
* Widget (classe in tkinter.ttk):        ttk Widget.         (line    9)
* width (sys.hash_info attributo):       sys — System-specific parameters and functions.
                                                             (line 1071)
* width (textwrap.TextWrapper attributo): textwrap — Text wrapping and filling.
                                                             (line  166)
* width() (nel modulo turtle):           Drawing state.      (line   18)
* WIFCONTINUED() (nel modulo os):        Process Management. (line 1127)
* WIFEXITED() (nel modulo os):           Process Management. (line 1155)
* WIFSIGNALED() (nel modulo os):         Process Management. (line 1148)
* WIFSTOPPED() (nel modulo os):          Process Management. (line 1137)
* win32_code_page_search_function() (nel modulo encodings): encodings — Encodings package.
                                                             (line   39)
* win32_edition() (nel modulo platform): Windows platform.   (line   22)
* win32_is_iot() (nel modulo platform):  Windows platform.   (line   31)
* win32_ver() (nel modulo platform):     Windows platform.   (line    6)
* WinDLL (classe in ctypes):             Loading shared libraries.
                                                             (line   54)
* window (classe in curses):             Window Objects.     (line    6)
* window manager (widgets):              The Window Manager. (line    6)
* window_height() (nel modulo turtle):   Settings and special methods.
                                                             (line  117)
* window_log (compression.zstd.CompressionParameter attributo): Advanced parameter control.
                                                             (line   53)
* window_log_max (compression.zstd.DecompressionParameter attributo): Advanced parameter control.
                                                             (line  287)
* window_width() (nel modulo turtle):    Settings and special methods.
                                                             (line  124)
* window() (curses.panel.Panel metodo):  Panel Objects.      (line   62)
* Windows:                               Complete Python programs.
                                                             (line   25)
* Windows ini file:                      configparser — Configuration file parser.
                                                             (line    8)
* WindowsError:                          Concrete exceptions.
                                                             (line  515)
* WindowsPath (classe in pathlib):       Concrete paths.     (line   36)
* WindowsProactorEventLoopPolicy (classe in asyncio): Policy Objects.
                                                             (line   67)
* WindowsRegistryFinder (classe in importlib.machinery): importlib machinery – Importers and path hooks.
                                                             (line   93)
* WindowsSelectorEventLoopPolicy (classe in asyncio): Policy Objects.
                                                             (line   56)
* winerror (OSError attributo):          Concrete exceptions.
                                                             (line  177)
* WinError() (nel modulo ctypes):        Utility functions.  (line  279)
* WINFUNCTYPE() (nel modulo ctypes):     Function prototypes.
                                                             (line   25)
* WinSock:                               select — Waiting for I/O completion.
                                                             (line  153)
* winver (nel modulo sys):               sys — System-specific parameters and functions.
                                                             (line 2224)
* With (classe in ast):                  Control flow.       (line  230)
* WITH_EXCEPT_START (opcode):            Python Bytecode Instructions.
                                                             (line  482)
* with_hostmask (ipaddress.IPv4Interface attributo): Interface objects.
                                                             (line   55)
* with_hostmask (ipaddress.IPv4Network attributo): Network objects.
                                                             (line  123)
* with_hostmask (ipaddress.IPv6Interface attributo): Interface objects.
                                                             (line   82)
* with_hostmask (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  326)
* with_name() (pathlib.PurePath metodo): Methods and properties.
                                                             (line  361)
* with_netmask (ipaddress.IPv4Interface attributo): Interface objects.
                                                             (line   46)
* with_netmask (ipaddress.IPv4Network attributo): Network objects.
                                                             (line  118)
* with_netmask (ipaddress.IPv6Interface attributo): Interface objects.
                                                             (line   80)
* with_netmask (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  324)
* with_prefixlen (ipaddress.IPv4Interface attributo): Interface objects.
                                                             (line   37)
* with_prefixlen (ipaddress.IPv4Network attributo): Network objects.
                                                             (line  105)
* with_prefixlen (ipaddress.IPv6Interface attributo): Interface objects.
                                                             (line   78)
* with_prefixlen (ipaddress.IPv6Network attributo): Network objects.
                                                             (line  318)
* with_pymalloc() (nel modulo test.support): test support — Utilities for the Python test suite.
                                                             (line  277)
* with_segments() (pathlib.PurePath metodo): Methods and properties.
                                                             (line  421)
* with_statement (nel modulo __future__): Module Contents<5>.
                                                             (line   31)
* with_stem() (pathlib.PurePath metodo): Methods and properties.
                                                             (line  377)
* with_suffix() (pathlib.PurePath metodo): Methods and properties.
                                                             (line  400)
* with_traceback() (BaseException metodo): Base classes.     (line   25)
* withitem (classe in ast):              Control flow.       (line  241)
* WNOHANG (nel modulo os):               Process Management. (line 1042)
* WNOWAIT (nel modulo os):               Process Management. (line 1050)
* wordchars (shlex.shlex attributo):     shlex Objects.      (line   91)
* World Wide Web:                        Internet Protocols and Support.
                                                             (line    6)
* World Wide Web <1>:                    urllib parse — Parse URLs into components.
                                                             (line    8)
* World Wide Web <2>:                    urllib robotparser — Parser for robots txt.
                                                             (line    8)
* wrap_bio() (ssl.SSLContext metodo):    SSL Contexts.       (line  455)
* wrap_future() (nel modulo asyncio):    Future Functions.   (line   53)
* wrap_socket() (ssl.SSLContext metodo): SSL Contexts.       (line  388)
* wrap() (nel modulo textwrap):          textwrap — Text wrapping and filling.
                                                             (line   16)
* wrap() (textwrap.TextWrapper metodo):  textwrap — Text wrapping and filling.
                                                             (line  292)
* wrapper() (nel modulo curses):         Functions<5>.       (line  620)
* WrapperDescriptorType (nel modulo types): Standard Interpreter Types.
                                                             (line   88)
* wraps() (nel modulo functools):        functools — Higher-order functions and operations on callable objects.
                                                             (line  747)
* WRITABLE (inspect.BufferFlags attributo): Buffer flags.    (line   17)
* WRITABLE (nel modulo _tkinter):        File Handlers.      (line   41)
* writable() (bz2.BZ2File metodo):       De compression of files.
                                                             (line  106)
* writable() (io.IOBase metodo):         I/O Base Classes.   (line  152)
* WRITE (inspect.BufferFlags attributo): Buffer flags.       (line   51)
* write_byte() (mmap.mmap metodo):       mmap — Memory-mapped file support.
                                                             (line  339)
* write_bytes() (pathlib.Path metodo):   Reading and writing files.
                                                             (line   67)
* write_docstringdict() (nel modulo turtle): Translation of docstrings into different languages.
                                                             (line   10)
* write_eof() (asyncio.StreamWriter metodo): StreamWriter.   (line   55)
* write_eof() (asyncio.WriteTransport metodo): Write-only Transports.
                                                             (line   74)
* write_eof() (ssl.MemoryBIO metodo):    Memory BIO Support<2>.
                                                             (line  161)
* write_history_file() (nel modulo readline): History file.  (line   17)
* WRITE_RESTRICTED (C macro):            Member flags.       (line   29)
* write_results() (trace.CoverageResults metodo): Programmatic Interface.
                                                             (line   57)
* write_text() (pathlib.Path metodo):    Reading and writing files.
                                                             (line   48)
* write_through (io.TextIOWrapper attributo): Text I/O<2>.   (line  179)
* write() (asyncio.StreamWriter metodo): StreamWriter.       (line   15)
* write() (asyncio.WriteTransport metodo): Write-only Transports.
                                                             (line   60)
* write() (code.InteractiveInterpreter metodo): Interactive Interpreter Objects.
                                                             (line   63)
* write() (codecs.StreamWriter metodo):  StreamWriter Objects.
                                                             (line   31)
* write() (configparser.ConfigParser metodo): ConfigParser Objects.
                                                             (line  293)
* write() (email.generator.BytesGenerator metodo): email generator Generating MIME documents.
                                                             (line  118)
* write() (email.generator.Generator metodo): email generator Generating MIME documents.
                                                             (line  215)
* write() (io.BufferedIOBase metodo):    I/O Base Classes.   (line  335)
* write() (io.BufferedWriter metodo):    Buffered Streams.   (line  132)
* write() (io.RawIOBase metodo):         I/O Base Classes.   (line  212)
* write() (io.TextIOBase metodo):        Text I/O<2>.        (line   94)
* write() (io.Writer metodo):            Static Typing.      (line   40)
* write() (mmap.mmap metodo):            mmap — Memory-mapped file support.
                                                             (line  323)
* write() (nel modulo os):               File Descriptor Operations.
                                                             (line  971)
* write() (nel modulo turtle):           More drawing control.
                                                             (line   29)
* write() (sqlite3.Blob metodo):         Blob objects.       (line   53)
* write() (ssl.MemoryBIO metodo):        Memory BIO Support<2>.
                                                             (line  153)
* write() (ssl.SSLSocket metodo):        SSL Sockets.        (line   96)
* write() (xml.etree.ElementTree.ElementTree metodo): ElementTree Objects.
                                                             (line   62)
* write() (zipfile.ZipFile metodo):      ZipFile objects.    (line  279)
* writeframes() (wave.Wave_write metodo): Wave_write Objects.
                                                             (line   83)
* writeframesraw() (wave.Wave_write metodo): Wave_write Objects.
                                                             (line   76)
* writeheader() (csv.DictWriter metodo): Writer Objects.     (line   39)
* writelines() (asyncio.StreamWriter metodo): StreamWriter.  (line   29)
* writelines() (asyncio.WriteTransport metodo): Write-only Transports.
                                                             (line   67)
* writelines() (codecs.StreamWriter metodo): StreamWriter Objects.
                                                             (line   35)
* writelines() (io.IOBase metodo):       I/O Base Classes.   (line  158)
* writepy() (zipfile.PyZipFile metodo):  PyZipFile objects.  (line   21)
* Writer (classe in io):                 Static Typing.      (line   32)
* writer() (nel modulo csv):             Module Contents<3>. (line   39)
* writerow() (csv.csvwriter metodo):     Writer Objects.     (line   16)
* writerows() (csv.csvwriter metodo):    Writer Objects.     (line   25)
* writestr() (zipfile.ZipFile metodo):   ZipFile objects.    (line  315)
* WriteTransport (classe in asyncio):    Transports Hierarchy.
                                                             (line   11)
* writev() (nel modulo os):              File Descriptor Operations.
                                                             (line  990)
* writexml() (xml.dom.minidom.Node metodo): DOM Objects.     (line   27)
* writing;values:                        Expression statements.
                                                             (line   17)
* WrongDocumentErr:                      Exceptions<22>.     (line   97)
* wsgi_file_wrapper (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  275)
* wsgi_multiprocess (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  156)
* wsgi_multithread (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  149)
* wsgi_run_once (wsgiref.handlers.BaseHandler attributo): wsgiref handlers – server/gateway base classes.
                                                             (line  163)
* WSGIApplication (nel modulo wsgiref.types): wsgiref types – WSGI types for static type checking.
                                                             (line   20)
* WSGIEnvironment (nel modulo wsgiref.types): wsgiref types – WSGI types for static type checking.
                                                             (line   16)
* WSGIRequestHandler (classe in wsgiref.simple_server): wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line   78)
* WSGIServer (classe in wsgiref.simple_server): wsgiref simple_server – a simple WSGI HTTP server.
                                                             (line   48)
* wShowWindow (subprocess.STARTUPINFO attributo): Windows Popen Helpers.
                                                             (line   50)
* WSTOPPED (nel modulo os):              Process Management. (line 1020)
* WSTOPSIG() (nel modulo os):            Process Management. (line 1172)
* wstring_at() (nel modulo ctypes):      Utility functions.  (line  292)
* WTERMSIG() (nel modulo os):            Process Management. (line 1181)
* WUNTRACED (nel modulo os):             Process Management. (line 1031)
* WWW:                                   Internet Protocols and Support.
                                                             (line    6)
* WWW <1>:                               urllib parse — Parse URLs into components.
                                                             (line    8)
* WWW <2>:                               urllib robotparser — Parser for robots txt.
                                                             (line    8)
* WWW;server:                            http server — HTTP servers.
                                                             (line    8)
* X (nel modulo re):                     Flags.              (line  127)
* X_OK (nel modulo os):                  Files and Directories.
                                                             (line  107)
* X509 certificate:                      SSL Contexts.       (line  761)
* xatom() (imaplib.IMAP4 metodo):        IMAP4 Objects.      (line  467)
* XATTR_CREATE (nel modulo os):          Linux extended attributes.
                                                             (line   88)
* XATTR_REPLACE (nel modulo os):         Linux extended attributes.
                                                             (line   94)
* XATTR_SIZE_MAX (nel modulo os):        Linux extended attributes.
                                                             (line   83)
* xcor() (nel modulo turtle):            Tell Turtle’s state.
                                                             (line   34)
* XHTML:                                 html parser — Simple HTML and XHTML parser.
                                                             (line    8)
* XHTML_NAMESPACE (nel modulo xml.dom):  Module Contents<4>. (line   53)
* XML_ERROR_ABORTED (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  180)
* XML_ERROR_AMPLIFICATION_LIMIT_BREACH (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  215)
* XML_ERROR_ASYNC_ENTITY (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   29)
* XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   31)
* XML_ERROR_BAD_CHAR_REF (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   37)
* XML_ERROR_BINARY_ENTITY_REF (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   42)
* XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  135)
* XML_ERROR_DUPLICATE_ATTRIBUTE (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   47)
* XML_ERROR_ENTITY_DECLARED_IN_PE (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  126)
* XML_ERROR_EXTERNAL_ENTITY_HANDLING (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  116)
* XML_ERROR_FEATURE_REQUIRES_XML_DTD (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  128)
* XML_ERROR_FINISHED (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  184)
* XML_ERROR_INCOMPLETE_PE (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  152)
* XML_ERROR_INCORRECT_ENCODING (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   51)
* XML_ERROR_INVALID_ARGUMENT (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  207)
* XML_ERROR_INVALID_TOKEN (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   53)
* XML_ERROR_JUNK_AFTER_DOC_ELEMENT (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   59)
* XML_ERROR_MISPLACED_XML_PI (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   64)
* XML_ERROR_NO_BUFFER (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  211)
* XML_ERROR_NO_ELEMENTS (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   69)
* XML_ERROR_NO_MEMORY (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   74)
* XML_ERROR_NOT_STANDALONE (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  118)
* XML_ERROR_NOT_STARTED (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  220)
* XML_ERROR_NOT_SUSPENDED (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  175)
* XML_ERROR_PARAM_ENTITY_REF (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   78)
* XML_ERROR_PARTIAL_CHAR (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   82)
* XML_ERROR_PUBLICID (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  165)
* XML_ERROR_RECURSIVE_ENTITY_REF (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   86)
* XML_ERROR_RESERVED_NAMESPACE_URI (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  202)
* XML_ERROR_RESERVED_PREFIX_XML (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  192)
* XML_ERROR_RESERVED_PREFIX_XMLNS (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  197)
* XML_ERROR_SUSPEND_PE (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  190)
* XML_ERROR_SUSPENDED (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  169)
* XML_ERROR_SYNTAX (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   91)
* XML_ERROR_TAG_MISMATCH (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   95)
* XML_ERROR_TEXT_DECL (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  160)
* XML_ERROR_UNBOUND_PREFIX (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  142)
* XML_ERROR_UNCLOSED_CDATA_SECTION (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  112)
* XML_ERROR_UNCLOSED_TOKEN (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line   99)
* XML_ERROR_UNDECLARING_PREFIX (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  147)
* XML_ERROR_UNDEFINED_ENTITY (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  104)
* XML_ERROR_UNEXPECTED_STATE (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  124)
* XML_ERROR_UNKNOWN_ENCODING (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  108)
* XML_ERROR_XML_DECL (nel modulo xml.parsers.expat.errors): Expat error constants.
                                                             (line  156)
* XML_NAMESPACE (nel modulo xml.dom):    Module Contents<4>. (line   42)
* XML() (nel modulo xml.etree.ElementTree): Functions<8>.    (line  273)
* xmlcharrefreplace_errors() (nel modulo codecs): Error Handlers.
                                                             (line  172)
* xmlcharrefreplace;error handler's name: Error Handlers.    (line   54)
* XmlDeclHandler() (xml.parsers.expat.xmlparser metodo): XMLParser Objects<2>.
                                                             (line  263)
* XMLFilterBase (classe in xml.sax.saxutils): xml sax saxutils — SAX Utilities.
                                                             (line   73)
* XMLGenerator (classe in xml.sax.saxutils): xml sax saxutils — SAX Utilities.
                                                             (line   56)
* XMLID() (nel modulo xml.etree.ElementTree): Functions<8>.  (line  281)
* XMLNS_NAMESPACE (nel modulo xml.dom):  Module Contents<4>. (line   47)
* XMLParser (classe in xml.etree.ElementTree): XMLParser Objects.
                                                             (line    6)
* XMLParserType (nel modulo xml.parsers.expat): xml parsers expat — Fast XML parsing using Expat.
                                                             (line   34)
* XMLPullParser (classe in xml.etree.ElementTree): XMLPullParser Objects.
                                                             (line    6)
* XMLReader (classe in xml.sax.xmlreader): xml sax xmlreader — Interface for XML parsers.
                                                             (line   16)
* xor() (nel modulo operator):           operator — Standard operators as functions.
                                                             (line  180)
* xview() (tkinter.ttk.Treeview metodo): ttk Treeview.       (line  317)
* ycor() (nel modulo turtle):            Tell Turtle’s state.
                                                             (line   46)
* year (datetime.date attributo):        date Objects.       (line  146)
* year (datetime.datetime attributo):    datetime Objects.   (line  305)
* Year 2038:                             time — Time access and conversions.
                                                             (line   29)
* yeardatescalendar() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line  128)
* yeardays2calendar() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line  136)
* yeardayscalendar() (calendar.Calendar metodo): calendar — General calendar-related functions.
                                                             (line  143)
* YES (nel modulo tkinter.messagebox):   tkinter messagebox — Tkinter message prompts.
                                                             (line  157)
* YESEXPR (nel modulo locale):           locale — Internationalization services.
                                                             (line  289)
* YESNO (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  181)
* YESNOCANCEL (nel modulo tkinter.messagebox): tkinter messagebox — Tkinter message prompts.
                                                             (line  186)
* Yield (classe in ast):                 Function and class definitions.
                                                             (line  124)
* YIELD_VALUE (opcode):                  Python Bytecode Instructions.
                                                             (line  414)
* yield;examples:                        Generator-iterator methods.
                                                             (line   83)
* yield;expression:                      Yield expressions.  (line    6)
* yield;yield from (in What's New):      PEP 3151 Reworking the OS and IO exception hierarchy.
                                                             (line   88)
* YieldFrom (classe in ast):             Function and class definitions.
                                                             (line  124)
* yiq_to_rgb() (nel modulo colorsys):    colorsys — Conversions between color systems.
                                                             (line   32)
* yview() (tkinter.ttk.Treeview metodo): ttk Treeview.       (line  321)
* Z_BEST_COMPRESSION (nel modulo zlib):  zlib — Compression compatible with gzip.
                                                             (line  334)
* Z_BEST_SPEED (nel modulo zlib):        zlib — Compression compatible with gzip.
                                                             (line  330)
* Z_BLOCK (nel modulo zlib):             zlib — Compression compatible with gzip.
                                                             (line  400)
* Z_DEFAULT_COMPRESSION (nel modulo zlib): zlib — Compression compatible with gzip.
                                                             (line  338)
* Z_DEFAULT_STRATEGY (nel modulo zlib):  zlib — Compression compatible with gzip.
                                                             (line  343)
* Z_FILTERED (nel modulo zlib):          zlib — Compression compatible with gzip.
                                                             (line  347)
* Z_FINISH (nel modulo zlib):            zlib — Compression compatible with gzip.
                                                             (line  395)
* Z_FIXED (nel modulo zlib):             zlib — Compression compatible with gzip.
                                                             (line  365)
* Z_FULL_FLUSH (nel modulo zlib):        zlib — Compression compatible with gzip.
                                                             (line  390)
* Z_HUFFMAN_ONLY (nel modulo zlib):      zlib — Compression compatible with gzip.
                                                             (line  351)
* Z_NO_COMPRESSION (nel modulo zlib):    zlib — Compression compatible with gzip.
                                                             (line  324)
* Z_NO_FLUSH (nel modulo zlib):          zlib — Compression compatible with gzip.
                                                             (line  375)
* Z_PARTIAL_FLUSH (nel modulo zlib):     zlib — Compression compatible with gzip.
                                                             (line  381)
* Z_RLE (nel modulo zlib):               zlib — Compression compatible with gzip.
                                                             (line  355)
* Z_SYNC_FLUSH (nel modulo zlib):        zlib — Compression compatible with gzip.
                                                             (line  385)
* Z_TREES (nel modulo zlib):             zlib — Compression compatible with gzip.
                                                             (line  409)
* z;in string formatting:                Format Specification Mini-Language.
                                                             (line   93)
* z85decode() (nel modulo base64):       Base85 Encodings.   (line  100)
* z85encode() (nel modulo base64):       Base85 Encodings.   (line   92)
* Zen of Python:                         Glossary.           (line 1865)
* ZeroDivisionError:                     Concrete exceptions.
                                                             (line  501)
* zfill() (bytearray metodo):            Operazioni su Bytes e Bytearray.
                                                             (line  777)
* zfill() (bytes metodo):                Operazioni su Bytes e Bytearray.
                                                             (line  777)
* zfill() (str metodo):                  Metodi per le Stringhe.
                                                             (line  896)
* ZIP_BZIP2 (nel modulo zipfile):        zipfile — Work with ZIP archives.
                                                             (line  111)
* ZIP_DEFLATED (nel modulo zipfile):     zipfile — Work with ZIP archives.
                                                             (line  106)
* zip_longest() (nel modulo itertools):  Itertool Functions. (line  661)
* ZIP_LZMA (nel modulo zipfile):         zipfile — Work with ZIP archives.
                                                             (line  118)
* ZIP_STORED (nel modulo zipfile):       zipfile — Work with ZIP archives.
                                                             (line  102)
* ZIP_ZSTANDARD (nel modulo zipfile):    zipfile — Work with ZIP archives.
                                                             (line  125)
* zipapp command line option; -c:        Command-Line Interface<4>.
                                                             (line   45)
* zipapp command line option; -compress: Command-Line Interface<4>.
                                                             (line   45)
* zipapp command line option; -h:        Command-Line Interface<4>.
                                                             (line   61)
* zipapp command line option; -help:     Command-Line Interface<4>.
                                                             (line   61)
* zipapp command line option; -info:     Command-Line Interface<4>.
                                                             (line   55)
* zipapp command line option; -m:        Command-Line Interface<4>.
                                                             (line   35)
* zipapp command line option; -main:     Command-Line Interface<4>.
                                                             (line   35)
* zipapp command line option; -o:        Command-Line Interface<4>.
                                                             (line   18)
* zipapp command line option; -output:   Command-Line Interface<4>.
                                                             (line   18)
* zipapp command line option; -p:        Command-Line Interface<4>.
                                                             (line   29)
* zipapp command line option; -python:   Command-Line Interface<4>.
                                                             (line   29)
* ZipFile (classe in zipfile):           ZipFile objects.    (line    6)
* zipfile command line option; -c:       Command-line options<2>.
                                                             (line   11)
* zipfile command line option; -create:  Command-line options<2>.
                                                             (line   11)
* zipfile command line option; -e:       Command-line options<2>.
                                                             (line   16)
* zipfile command line option; -extract: Command-line options<2>.
                                                             (line   16)
* zipfile command line option; -l:       Command-line options<2>.
                                                             (line    6)
* zipfile command line option; -list:    Command-line options<2>.
                                                             (line    6)
* zipfile command line option; -metadata-encoding: Command-line options<2>.
                                                             (line   26)
* zipfile command line option; -t:       Command-line options<2>.
                                                             (line   21)
* zipfile command line option; -test:    Command-line options<2>.
                                                             (line   21)
* zipimporter (classe in zipimport):     zipimporter Objects.
                                                             (line    8)
* ZipImportError:                        zipimport — Import modules from Zip archives.
                                                             (line   58)
* ZipInfo (classe in zipfile):           zipfile — Work with ZIP archives.
                                                             (line   65)
* ZLIB_RUNTIME_VERSION (nel modulo zlib): zlib — Compression compatible with gzip.
                                                             (line  429)
* ZLIB_VERSION (nel modulo zlib):        zlib — Compression compatible with gzip.
                                                             (line  422)
* ZLIBNG_VERSION (nel modulo zlib):      zlib — Compression compatible with gzip.
                                                             (line  436)
* ZoneInfo (classe in zoneinfo):         The ZoneInfo class. (line    6)
* ZoneInfoNotFoundError:                 Exceptions and warnings.
                                                             (line    6)
* zscore() (statistics.NormalDist metodo): NormalDist objects.
                                                             (line  120)
* zstd_version_info (nel modulo compression.zstd): Miscellaneous<2>.
                                                             (line   32)
* ZstdCompressor (classe in compression.zstd): Compressing and decompressing data in memory.
                                                             (line   50)
* ZstdDecompressor (classe in compression.zstd): Compressing and decompressing data in memory.
                                                             (line  159)
* ZstdDict (classe in compression.zstd): Zstandard dictionaries.
                                                             (line   53)
* ZstdError:                             Exceptions<7>.      (line    6)
* ZstdFile (classe in compression.zstd): Reading and writing compressed files.
                                                             (line   49)

                                                                       
   



Tag Table:
Node: Top350
Ref: contents doc552
Ref: 13b552
Node: Novità in Python247350
Ref: whatsnew/index doc247446
Ref: 13c247446
Ref: whatsnew/index python-documentation-contents247446
Ref: 13d247446
Ref: whatsnew/index what-s-new-in-python247446
Ref: 13e247446
Ref: whatsnew/index whatsnew-index247446
Ref: 13f247446
Node: What’s new in Python 3 14249092
Ref: whatsnew/3 14 doc249209
Ref: 140249209
Ref: whatsnew/3 14 what-s-new-in-python-3-14249209
Ref: 141249209
Ref: What’s new in Python 3 14-Footnote-1249930
Node: Summary – Release highlights249972
Ref: whatsnew/3 14 summary-release-highlights250087
Ref: 143250087
Ref: Summary – Release highlights-Footnote-1253075
Ref: Summary – Release highlights-Footnote-2253117
Ref: Summary – Release highlights-Footnote-3253159
Ref: Summary – Release highlights-Footnote-4253201
Ref: Summary – Release highlights-Footnote-5253243
Ref: Summary – Release highlights-Footnote-6253285
Ref: Summary – Release highlights-Footnote-7253327
Ref: Summary – Release highlights-Footnote-8253369
Ref: Summary – Release highlights-Footnote-9253411
Ref: Summary – Release highlights-Footnote-10253453
Ref: Summary – Release highlights-Footnote-11253496
Ref: Summary – Release highlights-Footnote-12253546
Ref: Summary – Release highlights-Footnote-13253589
Node: New features253632
Ref: whatsnew/3 14 new-features253778
Ref: 15a253778
Node: PEP 649 & PEP 749 Deferred evaluation of annotations254484
Ref: whatsnew/3 14 pep-649-pep-749-deferred-evaluation-of-annotations254647
Ref: 15b254647
Ref: whatsnew/3 14 whatsnew314-deferred-annotations254647
Ref: 145254647
Ref: PEP 649 & PEP 749 Deferred evaluation of annotations-Footnote-1256688
Ref: PEP 649 & PEP 749 Deferred evaluation of annotations-Footnote-2256730
Ref: PEP 649 & PEP 749 Deferred evaluation of annotations-Footnote-3256786
Ref: PEP 649 & PEP 749 Deferred evaluation of annotations-Footnote-4256828
Ref: PEP 649 & PEP 749 Deferred evaluation of annotations-Footnote-5256870
Node: PEP 734 Multiple interpreters in the standard library256912
Ref: whatsnew/3 14 pep-734-multiple-interpreters-in-the-standard-library257116
Ref: 162257116
Ref: whatsnew/3 14 whatsnew314-multiple-interpreters257116
Ref: 146257116
Ref: PEP 734 Multiple interpreters in the standard library-Footnote-1261476
Ref: PEP 734 Multiple interpreters in the standard library-Footnote-2261518
Ref: PEP 734 Multiple interpreters in the standard library-Footnote-3261574
Node: PEP 750 Template string literals261616
Ref: whatsnew/3 14 pep-750-template-string-literals261808
Ref: 168261808
Ref: whatsnew/3 14 whatsnew314-template-string-literals261808
Ref: 144261808
Ref: PEP 750 Template string literals-Footnote-1264640
Ref: PEP 750 Template string literals-Footnote-2264696
Node: PEP 768 Safe external debugger interface264738
Ref: whatsnew/3 14 pep-768-safe-external-debugger-interface264902
Ref: 16c264902
Ref: whatsnew/3 14 whatsnew314-remote-debugging264902
Ref: 14e264902
Ref: PEP 768 Safe external debugger interface-Footnote-1266894
Ref: PEP 768 Safe external debugger interface-Footnote-2266950
Node: A new type of interpreter266992
Ref: whatsnew/3 14 a-new-type-of-interpreter267155
Ref: 171267155
Ref: whatsnew/3 14 whatsnew314-tail-call-interpreter267155
Ref: 14f267155
Ref: A new type of interpreter-Footnote-1268773
Ref: A new type of interpreter-Footnote-2268821
Node: Free-threaded mode improvements268877
Ref: whatsnew/3 14 free-threaded-mode-improvements269023
Ref: 173269023
Ref: whatsnew/3 14 whatsnew314-free-threaded-cpython269023
Ref: 150269023
Ref: Free-threaded mode improvements-Footnote-1271351
Ref: Free-threaded mode improvements-Footnote-2271393
Node: Improved error messages271435
Ref: whatsnew/3 14 improved-error-messages271605
Ref: 17a271605
Ref: whatsnew/3 14 whatsnew314-improved-error-messages271605
Ref: 151271605
Ref: Improved error messages-Footnote-1276178
Ref: Improved error messages-Footnote-2276234
Ref: Improved error messages-Footnote-3276290
Ref: Improved error messages-Footnote-4276346
Ref: Improved error messages-Footnote-5276401
Ref: Improved error messages-Footnote-6276457
Ref: Improved error messages-Footnote-7276513
Ref: Improved error messages-Footnote-8276569
Ref: Improved error messages-Footnote-9276625
Ref: Improved error messages-Footnote-10276681
Node: PEP 784 Zstandard support in the standard library276738
Ref: whatsnew/3 14 pep-784-zstandard-support-in-the-standard-library276911
Ref: 187276911
Ref: whatsnew/3 14 whatsnew314-zstandard276911
Ref: 148276911
Ref: PEP 784 Zstandard support in the standard library-Footnote-1278564
Ref: PEP 784 Zstandard support in the standard library-Footnote-2278605
Ref: PEP 784 Zstandard support in the standard library-Footnote-3278661
Node: Asyncio introspection capabilities278703
Ref: whatsnew/3 14 asyncio-introspection-capabilities278885
Ref: 188278885
Ref: whatsnew/3 14 whatsnew314-asyncio-introspection278885
Ref: 147278885
Ref: Asyncio introspection capabilities-Footnote-1284520
Node: Concurrent safe warnings control284575
Ref: whatsnew/3 14 concurrent-safe-warnings-control284699
Ref: 189284699
Ref: whatsnew/3 14 whatsnew314-concurrent-warnings-control284699
Ref: 153284699
Ref: Concurrent safe warnings control-Footnote-1285381
Node: Other language changes285437
Ref: whatsnew/3 14 other-language-changes285564
Ref: 18b285564
Ref: Other language changes-Footnote-1287066
Ref: Other language changes-Footnote-2287122
Ref: Other language changes-Footnote-3287177
Ref: Other language changes-Footnote-4287233
Ref: Other language changes-Footnote-5287289
Node: Built-ins287345
Ref: whatsnew/3 14 built-ins287450
Ref: 18f287450
Ref: Built-ins-Footnote-1289628
Ref: Built-ins-Footnote-2289684
Ref: Built-ins-Footnote-3289739
Ref: Built-ins-Footnote-4289794
Ref: Built-ins-Footnote-5289850
Ref: Built-ins-Footnote-6289906
Ref: Built-ins-Footnote-7289962
Ref: Built-ins-Footnote-8290018
Ref: Built-ins-Footnote-9290074
Node: Command line and environment290130
Ref: whatsnew/3 14 command-line-and-environment290305
Ref: 1a7290305
Ref: Command line and environment-Footnote-1291224
Ref: Command line and environment-Footnote-2291280
Ref: Command line and environment-Footnote-3291336
Ref: Command line and environment-Footnote-4291368
Node: PEP 758 Allow except and except* expressions without brackets291424
Ref: whatsnew/3 14 pep-758-allow-except-and-except-expressions-without-brackets291628
Ref: 1aa291628
Ref: whatsnew/3 14 whatsnew314-bracketless-except291628
Ref: 14c291628
Ref: PEP 758 Allow except and except* expressions without brackets-Footnote-1292226
Ref: PEP 758 Allow except and except* expressions without brackets-Footnote-2292268
Node: PEP 765 Control flow in finally blocks292324
Ref: whatsnew/3 14 pep-765-control-flow-in-finally-blocks292530
Ref: 1ad292530
Ref: whatsnew/3 14 whatsnew314-finally-syntaxwarning292530
Ref: 14d292530
Ref: PEP 765 Control flow in finally blocks-Footnote-1293722
Ref: PEP 765 Control flow in finally blocks-Footnote-2293764
Node: Incremental garbage collection293820
Ref: whatsnew/3 14 incremental-garbage-collection293990
Ref: 1b2293990
Ref: whatsnew/3 14 whatsnew314-incremental-gc293990
Ref: 152293990
Ref: Incremental garbage collection-Footnote-1294811
Node: Default interactive shell294867
Ref: whatsnew/3 14 default-interactive-shell294990
Ref: 1b4294990
Ref: whatsnew/3 14 whatsnew314-pyrepl-highlighting295059
Ref: 154295059
Ref: Default interactive shell-Footnote-1296338
Ref: Default interactive shell-Footnote-2296394
Node: New modules296449
Ref: whatsnew/3 14 new-modules296580
Ref: 1b9296580
Ref: New modules-Footnote-1297744
Ref: New modules-Footnote-2297800
Ref: New modules-Footnote-3297856
Ref: New modules-Footnote-4297912
Node: Improved modules297968
Ref: whatsnew/3 14 improved-modules298090
Ref: 1ba298090
Node: argparse298947
Ref: whatsnew/3 14 argparse299020
Ref: 1bb299020
Ref: argparse-Footnote-1299893
Ref: argparse-Footnote-2299948
Ref: argparse-Footnote-3300004
Node: ast300060
Ref: whatsnew/3 14 ast300149
Ref: 1be300149
Ref: ast-Footnote-1301113
Ref: ast-Footnote-2301168
Ref: ast-Footnote-3301224
Ref: ast-Footnote-4301280
Ref: ast-Footnote-5301336
Ref: ast-Footnote-6301392
Node: asyncio301448
Ref: whatsnew/3 14 asyncio301537
Ref: 1c6301537
Ref: asyncio-Footnote-1302670
Ref: asyncio-Footnote-2302726
Node: calendar302781
Ref: whatsnew/3 14 calendar302885
Ref: 1ce302885
Ref: whatsnew/3 14 whatsnew314-color-calendar302920
Ref: 1cf302920
Ref: calendar-Footnote-1303207
Node: concurrent futures303263
Ref: whatsnew/3 14 concurrent-futures303372
Ref: 1d1303372
Ref: whatsnew/3 14 whatsnew314-concurrent-futures-interp-pool303427
Ref: 167303427
Ref: whatsnew/3 14 whatsnew314-concurrent-futures-start-method303854
Ref: 1d3303854
Ref: concurrent futures-Footnote-1305334
Ref: concurrent futures-Footnote-2305390
Ref: concurrent futures-Footnote-3305445
Ref: concurrent futures-Footnote-4305501
Node: configparser305556
Ref: whatsnew/3 14 configparser305668
Ref: 1dd305668
Ref: configparser-Footnote-1306063
Node: contextvars306119
Ref: whatsnew/3 14 contextvars306219
Ref: 1e0306219
Ref: contextvars-Footnote-1306437
Node: ctypes306493
Ref: whatsnew/3 14 ctypes306587
Ref: 1e3306587
Ref: ctypes-Footnote-1309065
Ref: ctypes-Footnote-2309120
Ref: ctypes-Footnote-3309175
Ref: ctypes-Footnote-4309231
Ref: ctypes-Footnote-5309287
Ref: ctypes-Footnote-6309343
Ref: ctypes-Footnote-7309399
Ref: ctypes-Footnote-8309454
Ref: ctypes-Footnote-9309510
Ref: ctypes-Footnote-10309566
Ref: ctypes-Footnote-11309623
Node: curses309680
Ref: whatsnew/3 14 curses309771
Ref: 1f5309771
Ref: curses-Footnote-1310073
Node: datetime310129
Ref: whatsnew/3 14 datetime310221
Ref: 1f8310221
Ref: datetime-Footnote-1310470
Node: decimal310525
Ref: whatsnew/3 14 decimal310618
Ref: 1fc310618
Ref: decimal-Footnote-1311048
Ref: decimal-Footnote-2311104
Node: difflib311159
Ref: whatsnew/3 14 difflib311247
Ref: 200311247
Ref: difflib-Footnote-1311494
Node: dis311550
Ref: whatsnew/3 14 dis311636
Ref: 202311636
Ref: dis-Footnote-1312360
Ref: dis-Footnote-2312416
Node: errno312472
Ref: whatsnew/3 14 errno312563
Ref: 20a312563
Ref: errno-Footnote-1312737
Node: faulthandler312793
Ref: whatsnew/3 14 faulthandler312888
Ref: 20c312888
Ref: faulthandler-Footnote-1313234
Node: fnmatch313290
Ref: whatsnew/3 14 fnmatch313389
Ref: 210313389
Ref: fnmatch-Footnote-1313604
Node: fractions313659
Ref: whatsnew/3 14 fractions313755
Ref: 212313755
Ref: fractions-Footnote-1314170
Ref: fractions-Footnote-2314225
Node: functools314281
Ref: whatsnew/3 14 functools314376
Ref: 215314376
Ref: functools-Footnote-1314906
Ref: functools-Footnote-2314962
Node: getopt315018
Ref: whatsnew/3 14 getopt315111
Ref: 21b315111
Ref: getopt-Footnote-1315440
Ref: getopt-Footnote-2315496
Node: getpass315552
Ref: whatsnew/3 14 getpass315644
Ref: 21c315644
Ref: getpass-Footnote-1316015
Node: graphlib316070
Ref: whatsnew/3 14 graphlib316161
Ref: 21e316161
Ref: graphlib-Footnote-1316407
Node: heapq316463
Ref: whatsnew/3 14 heapq316551
Ref: 220316551
Node: hmac316892
Ref: whatsnew/3 14 hmac316976
Ref: 226316976
Ref: hmac-Footnote-1317328
Ref: hmac-Footnote-2317387
Ref: hmac-Footnote-3317435
Node: http317490
Ref: whatsnew/3 14 http317576
Ref: 227317576
Ref: http-Footnote-1318437
Ref: http-Footnote-2318493
Node: imaplib318548
Ref: whatsnew/3 14 imaplib318637
Ref: 22c318637
Ref: imaplib-Footnote-1318858
Ref: imaplib-Footnote-2318917
Node: inspect318972
Ref: whatsnew/3 14 inspect319059
Ref: 22e319059
Ref: inspect-Footnote-1319737
Ref: inspect-Footnote-2319793
Ref: inspect-Footnote-3319849
Node: io319905
Ref: whatsnew/3 14 io319989
Ref: 234319989
Ref: io-Footnote-1320529
Ref: io-Footnote-2320585
Node: json320641
Ref: whatsnew/3 14 json320727
Ref: 23b320727
Ref: json-Footnote-1321513
Ref: json-Footnote-2321569
Ref: json-Footnote-3321625
Node: linecache321681
Ref: whatsnew/3 14 linecache321781
Ref: 23f321781
Ref: linecache-Footnote-1321982
Node: logging handlers322038
Ref: whatsnew/3 14 logging-handlers322138
Ref: 241322138
Ref: logging handlers-Footnote-1322557
Ref: logging handlers-Footnote-2322613
Node: math322669
Ref: whatsnew/3 14 math322769
Ref: 245322769
Ref: math-Footnote-1322988
Node: mimetypes323044
Ref: whatsnew/3 14 mimetypes323143
Ref: 246323143
Ref: mimetypes-Footnote-1326432
Ref: mimetypes-Footnote-2326487
Ref: mimetypes-Footnote-3326546
Ref: mimetypes-Footnote-4326605
Ref: mimetypes-Footnote-5326664
Ref: mimetypes-Footnote-6326723
Ref: mimetypes-Footnote-7326782
Ref: mimetypes-Footnote-8326841
Ref: mimetypes-Footnote-9326900
Ref: mimetypes-Footnote-10326959
Ref: mimetypes-Footnote-11327019
Ref: mimetypes-Footnote-12327079
Ref: mimetypes-Footnote-13327139
Ref: mimetypes-Footnote-14327199
Ref: mimetypes-Footnote-15327259
Ref: mimetypes-Footnote-16327319
Ref: mimetypes-Footnote-17327407
Ref: mimetypes-Footnote-18327507
Ref: mimetypes-Footnote-19327562
Ref: mimetypes-Footnote-20327618
Ref: mimetypes-Footnote-21327675
Ref: mimetypes-Footnote-22327731
Ref: mimetypes-Footnote-23327787
Node: multiprocessing327844
Ref: whatsnew/3 14 multiprocessing327947
Ref: 248327947
Ref: whatsnew/3 14 whatsnew314-multiprocessing-start-method327998
Ref: 249327998
Ref: multiprocessing-Footnote-1330130
Ref: multiprocessing-Footnote-2330185
Ref: multiprocessing-Footnote-3330240
Ref: multiprocessing-Footnote-4330296
Ref: multiprocessing-Footnote-5330352
Node: operator330408
Ref: whatsnew/3 14 operator330504
Ref: 254330504
Ref: operator-Footnote-1330900
Node: os330956
Ref: whatsnew/3 14 os331044
Ref: 257331044
Ref: os-Footnote-1331753
Ref: os-Footnote-2331809
Ref: os-Footnote-3331865
Node: os path331921
Ref: whatsnew/3 14 os-path332008
Ref: 261332008
Ref: os path-Footnote-1332399
Node: pathlib332454
Ref: whatsnew/3 14 pathlib332542
Ref: 265332542
Ref: pathlib-Footnote-1333530
Ref: pathlib-Footnote-2333585
Node: pdb333641
Ref: whatsnew/3 14 pdb333728
Ref: 26f333728
Ref: pdb-Footnote-1336880
Ref: pdb-Footnote-2336936
Ref: pdb-Footnote-3336992
Ref: pdb-Footnote-4337048
Ref: pdb-Footnote-5337104
Ref: pdb-Footnote-6337160
Ref: pdb-Footnote-7337216
Ref: pdb-Footnote-8337272
Ref: pdb-Footnote-9337328
Ref: pdb-Footnote-10337384
Node: pickle337441
Ref: whatsnew/3 14 pickle337529
Ref: 27a337529
Ref: pickle-Footnote-1337900
Node: platform337956
Ref: whatsnew/3 14 platform338046
Ref: 27c338046
Ref: platform-Footnote-1338292
Node: pydoc338348
Ref: whatsnew/3 14 pydoc338434
Ref: 27e338434
Ref: pydoc-Footnote-1338683
Node: re338739
Ref: whatsnew/3 14 re338823
Ref: 27f338823
Ref: re-Footnote-1339364
Ref: re-Footnote-2339420
Node: socket339476
Ref: whatsnew/3 14 socket339558
Ref: 280339558
Ref: socket-Footnote-1340795
Ref: socket-Footnote-2340851
Ref: socket-Footnote-3340907
Ref: socket-Footnote-4340962
Ref: socket-Footnote-5341018
Ref: socket-Footnote-6341073
Ref: socket-Footnote-7341129
Ref: socket-Footnote-8341185
Node: ssl341241
Ref: whatsnew/3 14 ssl341327
Ref: 285341327
Ref: ssl-Footnote-1341597
Node: struct341653
Ref: whatsnew/3 14 struct341741
Ref: 287341741
Ref: struct-Footnote-1342032
Node: symtable342088
Ref: whatsnew/3 14 symtable342176
Ref: 288342176
Ref: symtable-Footnote-1342475
Node: sys342531
Ref: whatsnew/3 14 sys342627
Ref: 28d342627
Ref: sys-Footnote-1343926
Ref: sys-Footnote-2343982
Ref: sys-Footnote-3344038
Ref: sys-Footnote-4344094
Ref: sys-Footnote-5344150
Node: sys monitoring344206
Ref: whatsnew/3 14 sys-monitoring344303
Ref: 294344303
Ref: sys monitoring-Footnote-1344588
Node: sysconfig344644
Ref: whatsnew/3 14 sysconfig344745
Ref: 297344745
Ref: sysconfig-Footnote-1344944
Node: tarfile345000
Ref: whatsnew/3 14 tarfile345096
Ref: 299345096
Ref: tarfile-Footnote-1346198
Ref: tarfile-Footnote-2346254
Ref: tarfile-Footnote-3346309
Ref: tarfile-Footnote-4346365
Ref: tarfile-Footnote-5346421
Ref: tarfile-Footnote-6346476
Ref: tarfile-Footnote-7346532
Ref: tarfile-Footnote-8346588
Node: threading346643
Ref: whatsnew/3 14 threading346737
Ref: 29f346737
Ref: threading-Footnote-1346993
Node: tkinter347048
Ref: whatsnew/3 14 tkinter347141
Ref: 2a1347141
Ref: tkinter-Footnote-1347533
Ref: tkinter-Footnote-2347589
Node: turtle347645
Ref: whatsnew/3 14 turtle347734
Ref: 2a2347734
Ref: turtle-Footnote-1348001
Node: types348057
Ref: whatsnew/3 14 types348145
Ref: 2a6348145
Ref: types-Footnote-1348392
Node: typing348448
Ref: whatsnew/3 14 typing348541
Ref: 2aa348541
Ref: whatsnew/3 14 whatsnew314-typing-union348574
Ref: 2a9348574
Ref: typing-Footnote-1351626
Ref: typing-Footnote-2351668
Node: unicodedata351724
Ref: whatsnew/3 14 unicodedata351820
Ref: 2af351820
Node: unittest351926
Ref: whatsnew/3 14 unittest352022
Ref: 2b0352022
Ref: whatsnew/3 14 whatsnew314-color-unittest352059
Ref: 2b1352059
Ref: unittest-Footnote-1353225
Ref: unittest-Footnote-2353281
Ref: unittest-Footnote-3353336
Node: urllib353391
Ref: whatsnew/3 14 urllib353480
Ref: 2bc353480
Ref: urllib-Footnote-1354948
Ref: urllib-Footnote-2355007
Ref: urllib-Footnote-3355063
Node: uuid355119
Ref: whatsnew/3 14 uuid355210
Ref: 2c1355210
Ref: uuid-Footnote-1355851
Ref: uuid-Footnote-2355910
Ref: uuid-Footnote-3355965
Ref: uuid-Footnote-4356024
Ref: uuid-Footnote-5356080
Node: webbrowser356136
Ref: whatsnew/3 14 webbrowser356228
Ref: 2c8356228
Node: zipfile356580
Ref: whatsnew/3 14 zipfile356659
Ref: 2c9356659
Ref: zipfile-Footnote-1357153
Ref: zipfile-Footnote-2357209
Node: Optimizations357264
Ref: whatsnew/3 14 optimizations357382
Ref: 2cd357382
Ref: Optimizations-Footnote-1358647
Node: asyncio<2>358703
Ref: whatsnew/3 14 id2358778
Ref: 2d1358778
Ref: asyncio<2>-Footnote-1359534
Ref: asyncio<2>-Footnote-2359590
Node: base64359646
Ref: whatsnew/3 14 base64359733
Ref: 2d2359733
Ref: base64-Footnote-1359956
Node: bdb360012
Ref: whatsnew/3 14 bdb360099
Ref: 2d4360099
Ref: bdb-Footnote-1360410
Node: difflib<2>360466
Ref: whatsnew/3 14 id3360549
Ref: 2d6360549
Ref: difflib<2>-Footnote-1360760
Node: gc360816
Ref: whatsnew/3 14 gc360901
Ref: 2d8360901
Ref: gc-Footnote-1362490
Node: io<2>362546
Ref: whatsnew/3 14 id4362631
Ref: 2dd362631
Ref: io<2>-Footnote-1362927
Ref: io<2>-Footnote-2362983
Node: pathlib<2>363038
Ref: whatsnew/3 14 id5363127
Ref: 2de363127
Ref: pathlib<2>-Footnote-1363380
Node: pdb<2>363436
Ref: whatsnew/3 14 id6363528
Ref: 2e0363528
Ref: pdb<2>-Footnote-1364049
Node: textwrap364105
Ref: whatsnew/3 14 textwrap364194
Ref: 2e3364194
Node: uuid<2>364495
Ref: whatsnew/3 14 id7364582
Ref: 2e4364582
Ref: uuid<2>-Footnote-1365002
Ref: uuid<2>-Footnote-2365058
Node: zlib365114
Ref: whatsnew/3 14 zlib365184
Ref: 2e8365184
Ref: zlib-Footnote-1365835
Ref: zlib-Footnote-2365878
Node: Removed365933
Ref: whatsnew/3 14 removed366045
Ref: 2e9366045
Node: argparse<2>366279
Ref: whatsnew/3 14 id8366349
Ref: 2ea366349
Ref: argparse<2>-Footnote-1367157
Ref: argparse<2>-Footnote-2367213
Node: ast<2>367269
Ref: whatsnew/3 14 id9367358
Ref: 2ee367358
Ref: ast<2>-Footnote-1368437
Ref: ast<2>-Footnote-2368493
Node: asyncio<3>368549
Ref: whatsnew/3 14 id10368632
Ref: 2f1368632
Ref: asyncio<3>-Footnote-1371441
Ref: asyncio<3>-Footnote-2371497
Node: email371553
Ref: whatsnew/3 14 email371643
Ref: 2f6371643
Ref: email-Footnote-1371906
Node: importlib abc371962
Ref: whatsnew/3 14 importlib-abc372051
Ref: 2f8372051
Ref: importlib abc-Footnote-1372479
Node: itertools372534
Ref: whatsnew/3 14 itertools372628
Ref: 2fb372628
Ref: itertools-Footnote-1372941
Node: pathlib<3>372997
Ref: whatsnew/3 14 id11373085
Ref: 2fc373085
Ref: pathlib<3>-Footnote-1373609
Ref: pathlib<3>-Footnote-2373664
Node: pkgutil373719
Ref: whatsnew/3 14 pkgutil373801
Ref: 2ff373801
Ref: pkgutil-Footnote-1374047
Node: pty374102
Ref: whatsnew/3 14 pty374181
Ref: 300374181
Ref: pty-Footnote-1374459
Node: sqlite3374515
Ref: whatsnew/3 14 sqlite3374596
Ref: 302374596
Ref: sqlite3-Footnote-1375184
Ref: sqlite3-Footnote-2375240
Ref: sqlite3-Footnote-3375296
Node: urllib<2>375352
Ref: whatsnew/3 14 id12375421
Ref: 306375421
Ref: urllib<2>-Footnote-1376133
Ref: urllib<2>-Footnote-2376189
Node: Deprecated376244
Ref: whatsnew/3 14 deprecated376367
Ref: 30a376367
Node: New deprecations376802
Ref: whatsnew/3 14 new-deprecations376904
Ref: 30b376904
Ref: New deprecations-Footnote-1382999
Ref: New deprecations-Footnote-2383055
Ref: New deprecations-Footnote-3383111
Ref: New deprecations-Footnote-4383166
Ref: New deprecations-Footnote-5383222
Ref: New deprecations-Footnote-6383278
Ref: New deprecations-Footnote-7383334
Ref: New deprecations-Footnote-8383390
Ref: New deprecations-Footnote-9383446
Ref: New deprecations-Footnote-10383502
Ref: New deprecations-Footnote-11383559
Ref: New deprecations-Footnote-12383615
Ref: New deprecations-Footnote-13383672
Ref: New deprecations-Footnote-14383729
Ref: New deprecations-Footnote-15383786
Ref: New deprecations-Footnote-16383829
Ref: New deprecations-Footnote-17383886
Ref: New deprecations-Footnote-18383943
Ref: New deprecations-Footnote-19384000
Ref: New deprecations-Footnote-20384057
Node: Pending removal in Python 3 15384114
Ref: whatsnew/3 14 pending-removal-in-python-3-15384255
Ref: 320384255
Ref: Pending removal in Python 3 15-Footnote-1388810
Ref: Pending removal in Python 3 15-Footnote-2388865
Ref: Pending removal in Python 3 15-Footnote-3388920
Ref: Pending removal in Python 3 15-Footnote-4388975
Ref: Pending removal in Python 3 15-Footnote-5389031
Ref: Pending removal in Python 3 15-Footnote-6389073
Ref: Pending removal in Python 3 15-Footnote-7389129
Node: Pending removal in Python 3 16389185
Ref: whatsnew/3 14 pending-removal-in-python-3-16389340
Ref: 33a389340
Ref: Pending removal in Python 3 16-Footnote-1393584
Ref: Pending removal in Python 3 16-Footnote-2393640
Ref: Pending removal in Python 3 16-Footnote-3393696
Ref: Pending removal in Python 3 16-Footnote-4393752
Node: Pending removal in Python 3 17393807
Ref: whatsnew/3 14 pending-removal-in-python-3-17393962
Ref: 341393962
Ref: Pending removal in Python 3 17-Footnote-1396896
Ref: Pending removal in Python 3 17-Footnote-2396954
Ref: Pending removal in Python 3 17-Footnote-3397009
Ref: Pending removal in Python 3 17-Footnote-4397067
Node: Pending removal in Python 3 18397122
Ref: whatsnew/3 14 pending-removal-in-python-3-18397277
Ref: 346397277
Ref: Pending removal in Python 3 18-Footnote-1397705
Node: Pending removal in Python 3 19397760
Ref: whatsnew/3 14 pending-removal-in-python-3-19397919
Ref: 347397919
Node: Pending removal in future versions398197
Ref: whatsnew/3 14 pending-removal-in-future-versions398317
Ref: 348398317
Ref: Pending removal in future versions-Footnote-1405582
Ref: Pending removal in future versions-Footnote-2405637
Ref: Pending removal in future versions-Footnote-3405693
Ref: Pending removal in future versions-Footnote-4405749
Ref: Pending removal in future versions-Footnote-5405805
Ref: Pending removal in future versions-Footnote-6405860
Ref: Pending removal in future versions-Footnote-7405915
Node: CPython bytecode changes405971
Ref: whatsnew/3 14 cpython-bytecode-changes406100
Ref: 365406100
Ref: CPython bytecode changes-Footnote-1408003
Ref: CPython bytecode changes-Footnote-2408059
Ref: CPython bytecode changes-Footnote-3408115
Ref: CPython bytecode changes-Footnote-4408171
Ref: CPython bytecode changes-Footnote-5408227
Ref: CPython bytecode changes-Footnote-6408283
Ref: CPython bytecode changes-Footnote-7408339
Node: Pseudo-instructions408395
Ref: whatsnew/3 14 pseudo-instructions408475
Ref: 371408475
Ref: Pseudo-instructions-Footnote-1410114
Ref: Pseudo-instructions-Footnote-2410170
Ref: Pseudo-instructions-Footnote-3410226
Ref: Pseudo-instructions-Footnote-4410282
Ref: Pseudo-instructions-Footnote-5410338
Ref: Pseudo-instructions-Footnote-6410394
Ref: Pseudo-instructions-Footnote-7410450
Node: C API changes410506
Ref: whatsnew/3 14 c-api-changes410638
Ref: 377410638
Node: Python configuration C API410819
Ref: whatsnew/3 14 python-configuration-c-api410929
Ref: 378410929
Ref: whatsnew/3 14 whatsnew314-capi-config410929
Ref: 155410929
Ref: Python configuration C API-Footnote-1412284
Ref: Python configuration C API-Footnote-2412326
Ref: Python configuration C API-Footnote-3412368
Ref: Python configuration C API-Footnote-4412424
Ref: Python configuration C API-Footnote-5412466
Node: New features in the C API412508
Ref: whatsnew/3 14 new-features-in-the-c-api412648
Ref: 37e412648
Ref: New features in the C API-Footnote-1419801
Ref: New features in the C API-Footnote-2419857
Ref: New features in the C API-Footnote-3419913
Ref: New features in the C API-Footnote-4419969
Ref: New features in the C API-Footnote-5420025
Ref: New features in the C API-Footnote-6420081
Ref: New features in the C API-Footnote-7420137
Ref: New features in the C API-Footnote-8420193
Ref: New features in the C API-Footnote-9420249
Ref: New features in the C API-Footnote-10420305
Ref: New features in the C API-Footnote-11420362
Ref: New features in the C API-Footnote-12420419
Ref: New features in the C API-Footnote-13420462
Ref: New features in the C API-Footnote-14420519
Ref: New features in the C API-Footnote-15420576
Ref: New features in the C API-Footnote-16420633
Ref: New features in the C API-Footnote-17420690
Ref: New features in the C API-Footnote-18420747
Ref: New features in the C API-Footnote-19420804
Ref: New features in the C API-Footnote-20420861
Ref: New features in the C API-Footnote-21420918
Ref: New features in the C API-Footnote-22420984
Ref: New features in the C API-Footnote-23421041
Ref: New features in the C API-Footnote-24421084
Ref: New features in the C API-Footnote-25421141
Node: Limited C API changes421198
Ref: whatsnew/3 14 limited-c-api-changes421326
Ref: 3c8421326
Ref: Limited C API changes-Footnote-1421972
Ref: Limited C API changes-Footnote-2422028
Ref: Limited C API changes-Footnote-3422084
Node: Removed C APIs422139
Ref: whatsnew/3 14 removed-c-apis422259
Ref: 3cd422259
Ref: whatsnew/3 14 whatsnew314-c-api-removed422259
Ref: 3ce422259
Ref: Removed C APIs-Footnote-1423288
Ref: Removed C APIs-Footnote-2423344
Ref: Removed C APIs-Footnote-3423400
Ref: Removed C APIs-Footnote-4423442
Ref: Removed C APIs-Footnote-5423498
Ref: Removed C APIs-Footnote-6423554
Node: Deprecated C APIs423610
Ref: whatsnew/3 14 deprecated-c-apis423700
Ref: 3d3423700
Ref: whatsnew/3 14 whatsnew314-c-api-deprecated423700
Ref: 3d4423700
Ref: Deprecated C APIs-Footnote-1425324
Ref: Deprecated C APIs-Footnote-2425380
Ref: Deprecated C APIs-Footnote-3425436
Ref: Deprecated C APIs-Footnote-4425491
Node: Pending removal in Python 3 15<2>425547
Ref: whatsnew/3 14 id13425676
Ref: 3da425676
Ref: Pending removal in Python 3 15<2>-Footnote-1432331
Ref: Pending removal in Python 3 15<2>-Footnote-2432384
Node: Pending removal in Python 3 16<2>432437
Ref: whatsnew/3 14 id14432608
Ref: 41f432608
Node: Pending removal in Python 3 18<2>432731
Ref: whatsnew/3 14 id15432906
Ref: 420432906
Ref: Pending removal in Python 3 18<2>-Footnote-1435581
Ref: Pending removal in Python 3 18<2>-Footnote-2435634
Node: Pending removal in future versions<2>435690
Ref: whatsnew/3 14 id16435823
Ref: 426435823
Node: Build changes437662
Ref: whatsnew/3 14 build-changes437792
Ref: 442437792
Ref: whatsnew/3 14 whatsnew314-build-changes437792
Ref: 156437792
Ref: Build changes-Footnote-1440311
Ref: Build changes-Footnote-2440353
Ref: Build changes-Footnote-3440402
Ref: Build changes-Footnote-4440483
Ref: Build changes-Footnote-5440539
Ref: Build changes-Footnote-6440595
Ref: Build changes-Footnote-7440651
Ref: Build changes-Footnote-8440701
Ref: Build changes-Footnote-9440757
Ref: Build changes-Footnote-10440799
Ref: Build changes-Footnote-11440856
Ref: Build changes-Footnote-12440913
Ref: Build changes-Footnote-13440970
Ref: Build changes-Footnote-14441026
Ref: Build changes-Footnote-15441083
Node: build-details json441140
Ref: whatsnew/3 14 build-details-json441250
Ref: 447441250
Ref: whatsnew/3 14 whatsnew314-build-details441250
Ref: 448441250
Ref: build-details json-Footnote-1442017
Node: Discontinuation of PGP signatures442059
Ref: whatsnew/3 14 discontinuation-of-pgp-signatures442222
Ref: 44a442222
Ref: whatsnew/3 14 whatsnew314-no-more-pgp442222
Ref: 158442222
Ref: Discontinuation of PGP signatures-Footnote-1442658
Ref: Discontinuation of PGP signatures-Footnote-2442718
Ref: Discontinuation of PGP signatures-Footnote-3442752
Node: Free-threaded Python is officially supported442794
Ref: whatsnew/3 14 free-threaded-python-is-officially-supported442997
Ref: 44b442997
Ref: whatsnew/3 14 whatsnew314-free-threaded-now-supported442997
Ref: 157442997
Ref: Free-threaded Python is officially supported-Footnote-1444107
Ref: Free-threaded Python is officially supported-Footnote-2444150
Ref: Free-threaded Python is officially supported-Footnote-3444193
Ref: Free-threaded Python is officially supported-Footnote-4444235
Node: Binary releases for the experimental just-in-time compiler444282
Ref: whatsnew/3 14 binary-releases-for-the-experimental-just-in-time-compiler444443
Ref: 44c444443
Ref: whatsnew/3 14 whatsnew314-jit-compiler444443
Ref: 159444443
Ref: Binary releases for the experimental just-in-time compiler-Footnote-1445991
Node: Porting to Python 3 14446033
Ref: whatsnew/3 14 porting-to-python-3-14446175
Ref: 14b446175
Node: Changes in the Python API446500
Ref: whatsnew/3 14 changes-in-the-python-api446635
Ref: 451446635
Ref: Changes in the Python API-Footnote-1449046
Ref: Changes in the Python API-Footnote-2449102
Ref: Changes in the Python API-Footnote-3449157
Node: Changes in annotations PEP 649 and PEP 749449213
Ref: whatsnew/3 14 changes-in-annotations-pep-649-and-pep-749449377
Ref: 455449377
Ref: whatsnew/3 14 whatsnew314-porting-annotations449377
Ref: 161449377
Node: Implications for annotated code449942
Ref: whatsnew/3 14 implications-for-annotated-code450104
Ref: 456450104
Node: Implications for readers of __annotations__450895
Ref: whatsnew/3 14 implications-for-readers-of-annotations451081
Ref: 457451081
Ref: Implications for readers of __annotations__-Footnote-1451902
Node: Related changes451954
Ref: whatsnew/3 14 related-changes452143
Ref: 45a452143
Node: from __future__ import annotations453187
Ref: whatsnew/3 14 from-future-import-annotations453324
Ref: 45c453324
Ref: from __future__ import annotations-Footnote-1453993
Node: Changes in the C API454035
Ref: whatsnew/3 14 changes-in-the-c-api454165
Ref: 45e454165
Ref: whatsnew/3 14 whatsnew314-refcount455121
Ref: 2d0455121
Ref: Changes in the C API-Footnote-1457317
Ref: Changes in the C API-Footnote-2457373
Ref: Changes in the C API-Footnote-3457429
Node: Notable changes in 3 14 1457482
Ref: whatsnew/3 14 notable-changes-in-3-14-1457602
Ref: 464457602
Ref: whatsnew/3 14 pythoncapi-compat-project457602
Ref: 465457602
Ref: Notable changes in 3 14 1-Footnote-1458006
Node: What’s New In Python 3 13458062
Ref: whatsnew/3 13 doc458210
Ref: 468458210
Ref: whatsnew/3 13 translation-repo458210
Ref: 469458210
Ref: whatsnew/3 13 what-s-new-in-python-3-13458210
Ref: 46a458210
Ref: What’s New In Python 3 13-Footnote-1458941
Node: Summary – Release Highlights458983
Ref: whatsnew/3 13 summary-release-highlights459098
Ref: 46b459098
Ref: whatsnew/3 13 whatsnew313-better-interactive-interpreter459393
Ref: 46c459393
Ref: whatsnew/3 13 whatsnew313-free-threaded-cpython459463
Ref: 46d459463
Ref: whatsnew/3 13 whatsnew313-jit-compiler459517
Ref: 46e459517
Ref: whatsnew/3 13 whatsnew313-pep594459991
Ref: 471459991
Ref: Summary – Release Highlights-Footnote-1465916
Ref: Summary – Release Highlights-Footnote-2465958
Ref: Summary – Release Highlights-Footnote-3466000
Ref: Summary – Release Highlights-Footnote-4466042
Ref: Summary – Release Highlights-Footnote-5466084
Ref: Summary – Release Highlights-Footnote-6466126
Ref: Summary – Release Highlights-Footnote-7466168
Ref: Summary – Release Highlights-Footnote-8466198
Ref: Summary – Release Highlights-Footnote-9466238
Ref: Summary – Release Highlights-Footnote-10466280
Ref: Summary – Release Highlights-Footnote-11466323
Ref: Summary – Release Highlights-Footnote-12466366
Ref: Summary – Release Highlights-Footnote-13466409
Ref: Summary – Release Highlights-Footnote-14466452
Ref: Summary – Release Highlights-Footnote-15466495
Ref: Summary – Release Highlights-Footnote-16466545
Ref: Summary – Release Highlights-Footnote-17466588
Ref: Summary – Release Highlights-Footnote-18466638
Ref: Summary – Release Highlights-Footnote-19466688
Node: New Features466731
Ref: whatsnew/3 13 new-features466877
Ref: 490466877
Node: A better interactive interpreter467249
Ref: whatsnew/3 13 a-better-interactive-interpreter467365
Ref: 491467365
Ref: A better interactive interpreter-Footnote-1468686
Ref: A better interactive interpreter-Footnote-2468712
Node: Improved error messages<2>468768
Ref: whatsnew/3 13 improved-error-messages468914
Ref: 496468914
Ref: whatsnew/3 13 whatsnew313-improved-error-messages468914
Ref: 473468914
Ref: Improved error messages<2>-Footnote-1471358
Ref: Improved error messages<2>-Footnote-2471388
Ref: Improved error messages<2>-Footnote-3471421
Ref: Improved error messages<2>-Footnote-4471477
Ref: Improved error messages<2>-Footnote-5471532
Node: Free-threaded CPython471588
Ref: whatsnew/3 13 free-threaded-cpython471743
Ref: 497471743
Ref: Free-threaded CPython-Footnote-1474747
Ref: Free-threaded CPython-Footnote-2474789
Node: An experimental just-in-time JIT compiler474842
Ref: whatsnew/3 13 an-experimental-just-in-time-jit-compiler475008
Ref: 49f475008
Ref: An experimental just-in-time JIT compiler-Footnote-1477621
Ref: An experimental just-in-time JIT compiler-Footnote-2477693
Node: Defined mutation semantics for locals477735
Ref: whatsnew/3 13 defined-mutation-semantics-for-locals477908
Ref: 4a1477908
Ref: whatsnew/3 13 whatsnew313-locals-semantics477908
Ref: 470477908
Ref: Defined mutation semantics for locals-Footnote-1480521
Ref: Defined mutation semantics for locals-Footnote-2480563
Ref: Defined mutation semantics for locals-Footnote-3480605
Node: Support for mobile platforms480660
Ref: whatsnew/3 13 support-for-mobile-platforms480783
Ref: 4a9480783
Ref: whatsnew/3 13 whatsnew313-platform-support480783
Ref: 48e480783
Ref: Support for mobile platforms-Footnote-1481834
Ref: Support for mobile platforms-Footnote-2481876
Ref: Support for mobile platforms-Footnote-3481918
Ref: Support for mobile platforms-Footnote-4481974
Ref: Support for mobile platforms-Footnote-5482016
Ref: Support for mobile platforms-Footnote-6482058
Ref: Support for mobile platforms-Footnote-7482114
Ref: Support for mobile platforms-Footnote-8482156
Node: Other Language Changes482198
Ref: whatsnew/3 13 other-language-changes482325
Ref: 4aa482325
Ref: Other Language Changes-Footnote-1487158
Ref: Other Language Changes-Footnote-2487213
Ref: Other Language Changes-Footnote-3487269
Ref: Other Language Changes-Footnote-4487325
Ref: Other Language Changes-Footnote-5487381
Ref: Other Language Changes-Footnote-6487437
Ref: Other Language Changes-Footnote-7487493
Ref: Other Language Changes-Footnote-8487542
Ref: Other Language Changes-Footnote-9487598
Ref: Other Language Changes-Footnote-10487653
Ref: Other Language Changes-Footnote-11487710
Ref: Other Language Changes-Footnote-12487767
Ref: Other Language Changes-Footnote-13487824
Ref: Other Language Changes-Footnote-14487881
Ref: Other Language Changes-Footnote-15487938
Ref: Other Language Changes-Footnote-16487995
Ref: Other Language Changes-Footnote-17488052
Ref: Other Language Changes-Footnote-18488108
Node: New Modules488165
Ref: whatsnew/3 13 new-modules488296
Ref: 4ba488296
Ref: New Modules-Footnote-1488520
Node: Improved Modules488576
Ref: whatsnew/3 13 improved-modules488701
Ref: 4bb488701
Node: argparse<3>489631
Ref: whatsnew/3 13 argparse489709
Ref: 4bc489709
Ref: argparse<3>-Footnote-1490032
Node: array490087
Ref: whatsnew/3 13 array490180
Ref: 4be490180
Ref: array-Footnote-1490616
Ref: array-Footnote-2490671
Node: ast<3>490727
Ref: whatsnew/3 13 ast490819
Ref: 4c2490819
Ref: ast<3>-Footnote-1492379
Ref: ast<3>-Footnote-2492435
Ref: ast<3>-Footnote-3492491
Ref: ast<3>-Footnote-4492547
Node: asyncio<4>492603
Ref: whatsnew/3 13 asyncio492699
Ref: 4c6492699
Ref: asyncio<4>-Footnote-1496461
Ref: asyncio<4>-Footnote-2496516
Ref: asyncio<4>-Footnote-3496572
Ref: asyncio<4>-Footnote-4496628
Ref: asyncio<4>-Footnote-5496684
Ref: asyncio<4>-Footnote-6496740
Ref: asyncio<4>-Footnote-7496795
Ref: asyncio<4>-Footnote-8496851
Ref: asyncio<4>-Footnote-9496907
Node: base64<2>496963
Ref: whatsnew/3 13 base64497063
Ref: 4d9497063
Ref: base64<2>-Footnote-1497358
Ref: base64<2>-Footnote-2497398
Node: compileall497453
Ref: whatsnew/3 13 compileall497564
Ref: 4da497564
Ref: compileall-Footnote-1497856
Node: concurrent futures<2>497912
Ref: whatsnew/3 13 concurrent-futures498029
Ref: 4dd498029
Ref: concurrent futures<2>-Footnote-1498337
Node: configparser<2>498393
Ref: whatsnew/3 13 configparser498504
Ref: 4de498504
Ref: configparser<2>-Footnote-1498834
Node: copy498889
Ref: whatsnew/3 13 copy498988
Ref: 4e0498988
Ref: copy-Footnote-1499905
Node: ctypes<2>499961
Ref: whatsnew/3 13 ctypes500048
Ref: 4e8500048
Ref: ctypes<2>-Footnote-1500983
Ref: ctypes<2>-Footnote-2501039
Node: dbm501095
Ref: whatsnew/3 13 dbm501184
Ref: 4ea501184
Ref: dbm-Footnote-1501638
Ref: dbm-Footnote-2501694
Node: dis<2>501750
Ref: whatsnew/3 13 dis501837
Ref: 4eb501837
Ref: dis<2>-Footnote-1502591
Ref: dis<2>-Footnote-2502647
Node: doctest502703
Ref: whatsnew/3 13 doctest502795
Ref: 4ee502795
Ref: whatsnew/3 13 whatsnew313-doctest502795
Ref: 475502795
Ref: doctest-Footnote-1503442
Ref: doctest-Footnote-2503472
Ref: doctest-Footnote-3503505
Ref: doctest-Footnote-4503561
Node: email<2>503617
Ref: whatsnew/3 13 email503707
Ref: 4f2503707
Ref: email<2>-Footnote-1504839
Ref: email<2>-Footnote-2504895
Ref: email<2>-Footnote-3504951
Node: enum505007
Ref: whatsnew/3 13 enum505102
Ref: 4f6505102
Node: fractions<2>505235
Ref: whatsnew/3 13 fractions505326
Ref: 4f9505326
Ref: fractions<2>-Footnote-1505644
Node: glob505700
Ref: whatsnew/3 13 glob505796
Ref: 4fb505796
Ref: glob-Footnote-1506045
Node: importlib506100
Ref: whatsnew/3 13 importlib506189
Ref: 4fd506189
Ref: importlib-Footnote-1507090
Ref: importlib-Footnote-2507146
Node: io<3>507202
Ref: whatsnew/3 13 io507296
Ref: 505507296
Ref: io<3>-Footnote-1507722
Node: ipaddress507777
Ref: whatsnew/3 13 ipaddress507874
Ref: 50b507874
Ref: ipaddress-Footnote-1508333
Ref: ipaddress-Footnote-2508389
Node: itertools<2>508445
Ref: whatsnew/3 13 itertools508544
Ref: 511508544
Ref: itertools<2>-Footnote-1508844
Node: marshal508900
Ref: whatsnew/3 13 marshal508997
Ref: 513508997
Ref: marshal-Footnote-1509332
Node: math<2>509388
Ref: whatsnew/3 13 math509485
Ref: 514509485
Ref: math<2>-Footnote-1509978
Node: mimetypes<2>510033
Ref: whatsnew/3 13 mimetypes510127
Ref: 516510127
Ref: mimetypes<2>-Footnote-1510444
Node: mmap510499
Ref: whatsnew/3 13 mmap510604
Ref: 519510604
Ref: mmap-Footnote-1511417
Ref: mmap-Footnote-2511473
Ref: mmap-Footnote-3511529
Node: multiprocessing<2>511584
Ref: whatsnew/3 13 multiprocessing511682
Ref: 51d511682
Ref: multiprocessing<2>-Footnote-1511986
Node: os<2>512042
Ref: whatsnew/3 13 os512146
Ref: 51e512146
Ref: os<2>-Footnote-1514614
Ref: os<2>-Footnote-2514670
Ref: os<2>-Footnote-3514726
Ref: os<2>-Footnote-4514780
Ref: os<2>-Footnote-5514836
Ref: os<2>-Footnote-6514891
Ref: os<2>-Footnote-7514947
Ref: os<2>-Footnote-8515002
Ref: os<2>-Footnote-9515058
Ref: os<2>-Footnote-10515114
Node: os path<2>515171
Ref: whatsnew/3 13 os-path515267
Ref: 531515267
Ref: os path<2>-Footnote-1515890
Ref: os path<2>-Footnote-2515945
Ref: os path<2>-Footnote-3516000
Node: pathlib<4>516055
Ref: whatsnew/3 13 pathlib516152
Ref: 533516152
Ref: pathlib<4>-Footnote-1517676
Ref: pathlib<4>-Footnote-2517731
Ref: pathlib<4>-Footnote-3517787
Ref: pathlib<4>-Footnote-4517842
Ref: pathlib<4>-Footnote-5517897
Ref: pathlib<4>-Footnote-6517952
Ref: pathlib<4>-Footnote-7518008
Node: pdb<3>518064
Ref: whatsnew/3 13 pdb518156
Ref: 53e518156
Ref: pdb<3>-Footnote-1519291
Ref: pdb<3>-Footnote-2519347
Ref: pdb<3>-Footnote-3519403
Ref: pdb<3>-Footnote-4519459
Ref: pdb<3>-Footnote-5519515
Node: queue519571
Ref: whatsnew/3 13 queue519659
Ref: 542519659
Ref: queue-Footnote-1519894
Node: random519950
Ref: whatsnew/3 13 random520037
Ref: 545520037
Ref: random-Footnote-1520211
Node: re<2>520267
Ref: whatsnew/3 13 re520355
Ref: 546520355
Node: shutil520514
Ref: whatsnew/3 13 shutil520600
Ref: 548520600
Ref: shutil-Footnote-1520828
Node: site520883
Ref: whatsnew/3 13 site520974
Ref: 54a520974
Ref: site-Footnote-1521225
Node: sqlite3<2>521281
Ref: whatsnew/3 13 sqlite3521372
Ref: 54c521372
Ref: sqlite3<2>-Footnote-1521813
Ref: sqlite3<2>-Footnote-2521869
Node: ssl<2>521924
Ref: whatsnew/3 13 ssl522021
Ref: 551522021
Ref: ssl<2>-Footnote-1522710
Ref: ssl<2>-Footnote-2522769
Node: statistics522825
Ref: whatsnew/3 13 statistics522922
Ref: 552522922
Ref: statistics-Footnote-1523431
Ref: statistics-Footnote-2523487
Node: subprocess523543
Ref: whatsnew/3 13 subprocess523640
Ref: 555523640
Ref: whatsnew/3 13 whatsnew313-subprocess523640
Ref: 556523640
Ref: subprocess-Footnote-1524580
Node: sys<2>524636
Ref: whatsnew/3 13 sys524731
Ref: 558524731
Ref: sys<2>-Footnote-1525020
Node: tempfile525075
Ref: whatsnew/3 13 tempfile525164
Ref: 55a525164
Ref: tempfile-Footnote-1525509
Ref: tempfile-Footnote-2525564
Node: time525620
Ref: whatsnew/3 13 time525713
Ref: 55b525713
Ref: time-Footnote-1526361
Ref: time-Footnote-2526416
Node: tkinter<2>526471
Ref: whatsnew/3 13 tkinter526565
Ref: 55e526565
Ref: tkinter<2>-Footnote-1528831
Ref: tkinter<2>-Footnote-2528886
Ref: tkinter<2>-Footnote-3528941
Ref: tkinter<2>-Footnote-4528996
Ref: tkinter<2>-Footnote-5529051
Ref: tkinter<2>-Footnote-6529106
Ref: tkinter<2>-Footnote-7529161
Ref: tkinter<2>-Footnote-8529217
Ref: tkinter<2>-Footnote-9529273
Node: traceback529329
Ref: whatsnew/3 13 traceback529427
Ref: 561529427
Ref: traceback-Footnote-1530157
Ref: traceback-Footnote-2530213
Node: types<2>530269
Ref: whatsnew/3 13 types530366
Ref: 567530366
Ref: types<2>-Footnote-1530693
Node: typing<2>530749
Ref: whatsnew/3 13 typing530851
Ref: 568530851
Ref: typing<2>-Footnote-1531837
Ref: typing<2>-Footnote-2531879
Ref: typing<2>-Footnote-3531921
Ref: typing<2>-Footnote-4531977
Ref: typing<2>-Footnote-5532033
Ref: typing<2>-Footnote-6532089
Node: unicodedata<2>532144
Ref: whatsnew/3 13 unicodedata532242
Ref: 56f532242
Ref: unicodedata<2>-Footnote-1532430
Ref: unicodedata<2>-Footnote-2532486
Node: venv532542
Ref: whatsnew/3 13 venv532639
Ref: 570532639
Ref: venv-Footnote-1533133
Node: warnings533189
Ref: whatsnew/3 13 warnings533275
Ref: 573533275
Ref: warnings-Footnote-1533739
Ref: warnings-Footnote-2533781
Node: xml533837
Ref: whatsnew/3 13 xml533928
Ref: 575533928
Ref: xml-Footnote-1534694
Ref: xml-Footnote-2534750
Ref: xml-Footnote-3534806
Node: zipimport534861
Ref: whatsnew/3 13 zipimport534935
Ref: 57b534935
Ref: zipimport-Footnote-1535139
Ref: zipimport-Footnote-2535201
Node: Optimizations<2>535256
Ref: whatsnew/3 13 optimizations535394
Ref: 57c535394
Ref: Optimizations<2>-Footnote-1536601
Ref: Optimizations<2>-Footnote-2536657
Ref: Optimizations<2>-Footnote-3536713
Node: Removed Modules And APIs536769
Ref: whatsnew/3 13 removed-modules-and-apis536907
Ref: 57e536907
Node: PEP 594 Remove «dead batteries» from the standard library537418
Ref: whatsnew/3 13 pep-594-remove-dead-batteries-from-the-standard-library537551
Ref: 57f537551
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-1542815
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-2542857
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-3542905
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-4542951
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-5543000
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-6543044
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-7543088
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-8543135
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-9543184
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-10543225
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-11543272
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-12543319
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-13543362
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-14543410
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-15543460
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-16543524
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-17543568
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-18543613
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-19543661
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-20543712
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-21543764
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-22543806
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-23543858
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-24543900
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-25543950
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-26543994
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-27544039
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-28544087
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-29544138
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-30544184
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-31544234
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-32544280
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-33544324
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-34544378
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-35544425
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-36544476
Ref: PEP 594 Remove «dead batteries» from the standard library-Footnote-37544533
Node: 2to3544590
Ref: whatsnew/3 13 to3544740
Ref: 583544740
Ref: 2to3-Footnote-1544967
Node: builtins545023
Ref: whatsnew/3 13 builtins545129
Ref: 584545129
Ref: builtins-Footnote-1545872
Ref: builtins-Footnote-2545927
Ref: builtins-Footnote-3545982
Node: configparser<3>546037
Ref: whatsnew/3 13 id3546157
Ref: 586546157
Ref: configparser<3>-Footnote-1546441
Node: importlib metadata546497
Ref: whatsnew/3 13 importlib-metadata546615
Ref: 587546615
Ref: importlib metadata-Footnote-1546872
Node: locale546928
Ref: whatsnew/3 13 locale547037
Ref: 58a547037
Ref: locale-Footnote-1547300
Node: opcode547356
Ref: whatsnew/3 13 opcode547455
Ref: 58b547455
Ref: opcode-Footnote-1548080
Ref: opcode-Footnote-2548136
Node: optparse548192
Ref: whatsnew/3 13 optparse548295
Ref: 58c548295
Ref: optparse-Footnote-1549085
Node: pathlib<5>549141
Ref: whatsnew/3 13 id4549243
Ref: 58d549243
Ref: pathlib<5>-Footnote-1549521
Node: re<3>549576
Ref: whatsnew/3 13 id5549681
Ref: 58e549681
Ref: re<3>-Footnote-1549947
Node: tkinter tix550003
Ref: whatsnew/3 13 tkinter-tix550107
Ref: 58f550107
Ref: tkinter tix-Footnote-1550382
Node: turtle<2>550437
Ref: whatsnew/3 13 turtle550545
Ref: 590550545
Ref: turtle<2>-Footnote-1550815
Node: typing<3>550871
Ref: whatsnew/3 13 id6550979
Ref: 591550979
Ref: typing<3>-Footnote-1551465
Ref: typing<3>-Footnote-2551520
Node: unittest<2>551576
Ref: whatsnew/3 13 unittest551684
Ref: 592551684
Ref: unittest<2>-Footnote-1552386
Ref: unittest<2>-Footnote-2552442
Node: urllib<3>552498
Ref: whatsnew/3 13 urllib552610
Ref: 597552610
Ref: urllib<3>-Footnote-1553217
Node: webbrowser<2>553273
Ref: whatsnew/3 13 webbrowser553365
Ref: 599553365
Ref: webbrowser<2>-Footnote-1553856
Ref: webbrowser<2>-Footnote-2553912
Node: New Deprecations553968
Ref: whatsnew/3 13 new-deprecations554114
Ref: 59b554114
Ref: New Deprecations-Footnote-1562718
Ref: New Deprecations-Footnote-2562773
Ref: New Deprecations-Footnote-3562828
Ref: New Deprecations-Footnote-4562884
Ref: New Deprecations-Footnote-5562940
Ref: New Deprecations-Footnote-6562995
Ref: New Deprecations-Footnote-7563051
Ref: New Deprecations-Footnote-8563106
Ref: New Deprecations-Footnote-9563162
Ref: New Deprecations-Footnote-10563218
Ref: New Deprecations-Footnote-11563275
Ref: New Deprecations-Footnote-12563331
Ref: New Deprecations-Footnote-13563387
Ref: New Deprecations-Footnote-14563443
Ref: New Deprecations-Footnote-15563500
Ref: New Deprecations-Footnote-16563556
Ref: New Deprecations-Footnote-17563613
Ref: New Deprecations-Footnote-18563670
Ref: New Deprecations-Footnote-19563727
Ref: New Deprecations-Footnote-20563783
Ref: New Deprecations-Footnote-21563840
Ref: New Deprecations-Footnote-22563897
Ref: New Deprecations-Footnote-23563954
Ref: New Deprecations-Footnote-24564011
Ref: New Deprecations-Footnote-25564068
Ref: New Deprecations-Footnote-26564125
Ref: New Deprecations-Footnote-27564182
Node: Pending removal in Python 3 14564239
Ref: whatsnew/3 13 pending-removal-in-python-3-14564364
Ref: 5ae564364
Ref: Pending removal in Python 3 14-Footnote-1568575
Ref: Pending removal in Python 3 14-Footnote-2568630
Ref: Pending removal in Python 3 14-Footnote-3568685
Ref: Pending removal in Python 3 14-Footnote-4568740
Ref: Pending removal in Python 3 14-Footnote-5568795
Ref: Pending removal in Python 3 14-Footnote-6568851
Ref: Pending removal in Python 3 14-Footnote-7568906
Ref: Pending removal in Python 3 14-Footnote-8568961
Ref: Pending removal in Python 3 14-Footnote-9569017
Ref: Pending removal in Python 3 14-Footnote-10569072
Ref: Pending removal in Python 3 14-Footnote-11569128
Node: Pending removal in Python 3 15<3>569184
Ref: whatsnew/3 13 pending-removal-in-python-3-15569351
Ref: 5b3569351
Ref: Pending removal in Python 3 15<3>-Footnote-1573906
Ref: Pending removal in Python 3 15<3>-Footnote-2573961
Ref: Pending removal in Python 3 15<3>-Footnote-3574016
Ref: Pending removal in Python 3 15<3>-Footnote-4574071
Ref: Pending removal in Python 3 15<3>-Footnote-5574127
Ref: Pending removal in Python 3 15<3>-Footnote-6574169
Ref: Pending removal in Python 3 15<3>-Footnote-7574225
Node: Pending removal in Python 3 16<3>574281
Ref: whatsnew/3 13 pending-removal-in-python-3-16574451
Ref: 5b4574451
Ref: Pending removal in Python 3 16<3>-Footnote-1578695
Ref: Pending removal in Python 3 16<3>-Footnote-2578751
Ref: Pending removal in Python 3 16<3>-Footnote-3578807
Ref: Pending removal in Python 3 16<3>-Footnote-4578863
Node: Pending removal in Python 3 17<2>578918
Ref: whatsnew/3 13 pending-removal-in-python-3-17579088
Ref: 5b5579088
Ref: Pending removal in Python 3 17<2>-Footnote-1582022
Ref: Pending removal in Python 3 17<2>-Footnote-2582080
Ref: Pending removal in Python 3 17<2>-Footnote-3582135
Ref: Pending removal in Python 3 17<2>-Footnote-4582193
Node: Pending removal in Python 3 18<3>582248
Ref: whatsnew/3 13 pending-removal-in-python-3-18582418
Ref: 5b6582418
Ref: Pending removal in Python 3 18<3>-Footnote-1582846
Node: Pending removal in Python 3 19<2>582901
Ref: whatsnew/3 13 pending-removal-in-python-3-19583075
Ref: 5b7583075
Node: Pending removal in future versions<3>583353
Ref: whatsnew/3 13 pending-removal-in-future-versions583485
Ref: 5b8583485
Ref: Pending removal in future versions<3>-Footnote-1590750
Ref: Pending removal in future versions<3>-Footnote-2590805
Ref: Pending removal in future versions<3>-Footnote-3590861
Ref: Pending removal in future versions<3>-Footnote-4590917
Ref: Pending removal in future versions<3>-Footnote-5590973
Ref: Pending removal in future versions<3>-Footnote-6591028
Ref: Pending removal in future versions<3>-Footnote-7591083
Node: CPython Bytecode Changes591139
Ref: whatsnew/3 13 cpython-bytecode-changes591274
Ref: 5b9591274
Ref: CPython Bytecode Changes-Footnote-1591715
Node: C API Changes591771
Ref: whatsnew/3 13 c-api-changes591903
Ref: 5bc591903
Node: New Features<2>592114
Ref: whatsnew/3 13 id7592202
Ref: 5bd592202
Ref: New Features<2>-Footnote-1603123
Ref: New Features<2>-Footnote-2603165
Ref: New Features<2>-Footnote-3603221
Ref: New Features<2>-Footnote-4603277
Ref: New Features<2>-Footnote-5603333
Ref: New Features<2>-Footnote-6603389
Ref: New Features<2>-Footnote-7603445
Ref: New Features<2>-Footnote-8603501
Ref: New Features<2>-Footnote-9603557
Ref: New Features<2>-Footnote-10603613
Ref: New Features<2>-Footnote-11603670
Ref: New Features<2>-Footnote-12603727
Ref: New Features<2>-Footnote-13603783
Ref: New Features<2>-Footnote-14603840
Ref: New Features<2>-Footnote-15603897
Ref: New Features<2>-Footnote-16603954
Ref: New Features<2>-Footnote-17604011
Ref: New Features<2>-Footnote-18604068
Ref: New Features<2>-Footnote-19604125
Ref: New Features<2>-Footnote-20604182
Ref: New Features<2>-Footnote-21604238
Ref: New Features<2>-Footnote-22604295
Ref: New Features<2>-Footnote-23604352
Ref: New Features<2>-Footnote-24604406
Ref: New Features<2>-Footnote-25604463
Ref: New Features<2>-Footnote-26604519
Ref: New Features<2>-Footnote-27604575
Ref: New Features<2>-Footnote-28604632
Ref: New Features<2>-Footnote-29604689
Ref: New Features<2>-Footnote-30604746
Ref: New Features<2>-Footnote-31604803
Ref: New Features<2>-Footnote-32604860
Node: Changed C APIs604917
Ref: whatsnew/3 13 changed-c-apis605035
Ref: 623605035
Ref: Changed C APIs-Footnote-1607630
Ref: Changed C APIs-Footnote-2607685
Ref: Changed C APIs-Footnote-3607741
Ref: Changed C APIs-Footnote-4607797
Ref: Changed C APIs-Footnote-5607853
Ref: Changed C APIs-Footnote-6607895
Ref: Changed C APIs-Footnote-7607951
Ref: Changed C APIs-Footnote-8608007
Node: Limited C API Changes608063
Ref: whatsnew/3 13 limited-c-api-changes608183
Ref: 630608183
Ref: Limited C API Changes-Footnote-1608886
Ref: Limited C API Changes-Footnote-2608941
Ref: Limited C API Changes-Footnote-3608997
Node: Removed C APIs<2>609053
Ref: whatsnew/3 13 removed-c-apis609179
Ref: 638609179
Ref: Removed C APIs<2>-Footnote-1615522
Ref: Removed C APIs<2>-Footnote-2615578
Ref: Removed C APIs<2>-Footnote-3615633
Ref: Removed C APIs<2>-Footnote-4615689
Ref: Removed C APIs<2>-Footnote-5615731
Ref: Removed C APIs<2>-Footnote-6615787
Ref: Removed C APIs<2>-Footnote-7615843
Ref: Removed C APIs<2>-Footnote-8615899
Ref: Removed C APIs<2>-Footnote-9615952
Ref: Removed C APIs<2>-Footnote-10616008
Ref: Removed C APIs<2>-Footnote-11616051
Ref: Removed C APIs<2>-Footnote-12616108
Ref: Removed C APIs<2>-Footnote-13616165
Ref: Removed C APIs<2>-Footnote-14616222
Node: Deprecated C APIs<2>616279
Ref: whatsnew/3 13 deprecated-c-apis616375
Ref: 64d616375
Ref: Deprecated C APIs<2>-Footnote-1619130
Ref: Deprecated C APIs<2>-Footnote-2619186
Ref: Deprecated C APIs<2>-Footnote-3619228
Ref: Deprecated C APIs<2>-Footnote-4619284
Ref: Deprecated C APIs<2>-Footnote-5619339
Ref: Deprecated C APIs<2>-Footnote-6619395
Ref: Deprecated C APIs<2>-Footnote-7619448
Node: Pending removal in Python 3 14<2>619504
Ref: whatsnew/3 13 id8619636
Ref: 64e619636
Ref: Pending removal in Python 3 14<2>-Footnote-1619956
Ref: Pending removal in Python 3 14<2>-Footnote-2619998
Ref: Pending removal in Python 3 14<2>-Footnote-3620054
Node: Pending removal in Python 3 15<4>620109
Ref: whatsnew/3 13 id9620283
Ref: 650620283
Ref: Pending removal in Python 3 15<4>-Footnote-1626938
Ref: Pending removal in Python 3 15<4>-Footnote-2626991
Node: Pending removal in Python 3 16<4>627044
Ref: whatsnew/3 13 id10627218
Ref: 651627218
Node: Pending removal in Python 3 18<4>627341
Ref: whatsnew/3 13 id11627519
Ref: 652627519
Ref: Pending removal in Python 3 18<4>-Footnote-1630194
Ref: Pending removal in Python 3 18<4>-Footnote-2630247
Node: Pending removal in future versions<4>630303
Ref: whatsnew/3 13 id12630439
Ref: 653630439
Node: Build Changes632280
Ref: whatsnew/3 13 build-changes632410
Ref: 654632410
Ref: whatsnew/3 13 pythoncapi-compat-project632410
Ref: 655632410
Ref: Build Changes-Footnote-1634988
Ref: Build Changes-Footnote-2635030
Ref: Build Changes-Footnote-3635086
Ref: Build Changes-Footnote-4635128
Ref: Build Changes-Footnote-5635184
Ref: Build Changes-Footnote-6635226
Ref: Build Changes-Footnote-7635282
Ref: Build Changes-Footnote-8635324
Ref: Build Changes-Footnote-9635380
Ref: Build Changes-Footnote-10635435
Ref: Build Changes-Footnote-11635492
Ref: Build Changes-Footnote-12635549
Ref: Build Changes-Footnote-13635597
Ref: Build Changes-Footnote-14635654
Ref: Build Changes-Footnote-15635711
Ref: Build Changes-Footnote-16635768
Node: Porting to Python 3 13635824
Ref: whatsnew/3 13 porting-to-python-3-13635964
Ref: 472635964
Node: Changes in the Python API<2>636250
Ref: whatsnew/3 13 changes-in-the-python-api636369
Ref: 658636369
Ref: whatsnew/3 13 pep667-porting-notes-py636440
Ref: 4a7636440
Ref: Changes in the Python API<2>-Footnote-1639983
Ref: Changes in the Python API<2>-Footnote-2640025
Ref: Changes in the Python API<2>-Footnote-3640067
Ref: Changes in the Python API<2>-Footnote-4640109
Ref: Changes in the Python API<2>-Footnote-5640151
Ref: Changes in the Python API<2>-Footnote-6640207
Ref: Changes in the Python API<2>-Footnote-7640263
Ref: Changes in the Python API<2>-Footnote-8640318
Node: Changes in the C API<2>640374
Ref: whatsnew/3 13 changes-in-the-c-api640493
Ref: 65f640493
Ref: whatsnew/3 13 pep667-porting-notes-c643148
Ref: 4a8643148
Ref: Changes in the C API<2>-Footnote-1646924
Ref: Changes in the C API<2>-Footnote-2646980
Ref: Changes in the C API<2>-Footnote-3647036
Ref: Changes in the C API<2>-Footnote-4647092
Ref: Changes in the C API<2>-Footnote-5647147
Ref: Changes in the C API<2>-Footnote-6647203
Node: Regression Test Changes647256
Ref: whatsnew/3 13 regression-test-changes647374
Ref: 665647374
Ref: Regression Test Changes-Footnote-1647815
Node: Novità in Python 3 12647871
Ref: whatsnew/3 12 doc648019
Ref: 667648019
Ref: whatsnew/3 12 translation-repo648019
Ref: 668648019
Ref: whatsnew/3 12 what-s-new-in-python-3-12648019
Ref: 669648019
Ref: Novità in Python 3 12-Footnote-1648814
Node: Sommario – Punti salienti del rilascio648856
Ref: whatsnew/3 12 summary-release-highlights648983
Ref: 66a648983
Ref: Sommario – Punti salienti del rilascio-Footnote-1654142
Ref: Sommario – Punti salienti del rilascio-Footnote-2654190
Ref: Sommario – Punti salienti del rilascio-Footnote-3654232
Ref: Sommario – Punti salienti del rilascio-Footnote-4654274
Ref: Sommario – Punti salienti del rilascio-Footnote-5654333
Ref: Sommario – Punti salienti del rilascio-Footnote-6654412
Node: Nuove Funzionalità654467
Ref: whatsnew/3 12 new-features654649
Ref: 680654649
Node: PEP 695 Sintassi dei Parametri di Tipo655303
Ref: whatsnew/3 12 pep-695-type-parameter-syntax655455
Ref: 681655455
Ref: whatsnew/3 12 whatsnew312-pep695655455
Ref: 66c655455
Ref: PEP 695 Sintassi dei Parametri di Tipo-Footnote-1658234
Ref: PEP 695 Sintassi dei Parametri di Tipo-Footnote-2658276
Ref: PEP 695 Sintassi dei Parametri di Tipo-Footnote-3658318
Ref: PEP 695 Sintassi dei Parametri di Tipo-Footnote-4658360
Node: PEP 701 Formalizzazione sintattica delle f-string658416
Ref: whatsnew/3 12 pep-701-syntactic-formalization-of-f-strings658606
Ref: 687658606
Ref: whatsnew/3 12 whatsnew312-pep701658606
Ref: 66f658606
Ref: PEP 701 Formalizzazione sintattica delle f-string-Footnote-1663362
Ref: PEP 701 Formalizzazione sintattica delle f-string-Footnote-2663404
Ref: PEP 701 Formalizzazione sintattica delle f-string-Footnote-3663446
Ref: PEP 701 Formalizzazione sintattica delle f-string-Footnote-4663488
Node: PEP 684 Un GIL per interprete663544
Ref: whatsnew/3 12 pep-684-a-per-interpreter-gil663744
Ref: 689663744
Ref: whatsnew/3 12 whatsnew312-pep684663744
Ref: 670663744
Ref: PEP 684 Un GIL per interprete-Footnote-1664878
Ref: PEP 684 Un GIL per interprete-Footnote-2664920
Ref: PEP 684 Un GIL per interprete-Footnote-3664962
Node: PEP 669 Monitoraggio a basso impatto per CPython665018
Ref: whatsnew/3 12 pep-669-low-impact-monitoring-for-cpython665227
Ref: 68b665227
Ref: whatsnew/3 12 whatsnew312-pep669665227
Ref: 671665227
Ref: PEP 669 Monitoraggio a basso impatto per CPython-Footnote-1665819
Ref: PEP 669 Monitoraggio a basso impatto per CPython-Footnote-2665861
Node: PEP 688 Rendere accessibile il protocollo buffer in Python665917
Ref: whatsnew/3 12 pep-688-making-the-buffer-protocol-accessible-in-python666133
Ref: 68c666133
Ref: whatsnew/3 12 whatsnew312-pep688666133
Ref: 673666133
Ref: PEP 688 Rendere accessibile il protocollo buffer in Python-Footnote-1666852
Ref: PEP 688 Rendere accessibile il protocollo buffer in Python-Footnote-2666894
Node: PEP 709 Inlining delle comprehension666950
Ref: whatsnew/3 12 pep-709-comprehension-inlining667147
Ref: 68f667147
Ref: whatsnew/3 12 whatsnew312-pep709667147
Ref: 679667147
Ref: PEP 709 Inlining delle comprehension-Footnote-1669012
Ref: PEP 709 Inlining delle comprehension-Footnote-2669054
Node: Messaggi di errore migliorati669096
Ref: whatsnew/3 12 improved-error-messages669226
Ref: 672669226
Ref: Messaggi di errore migliorati-Footnote-1671686
Ref: Messaggi di errore migliorati-Footnote-2671741
Ref: Messaggi di errore migliorati-Footnote-3671796
Ref: Messaggi di errore migliorati-Footnote-4671851
Node: Nuove funzionalità relative agli hint di tipo671906
Ref: whatsnew/3 12 new-features-related-to-type-hints672077
Ref: 690672077
Ref: Nuove funzionalità relative agli hint di tipo-Footnote-1672595
Node: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa672637
Ref: whatsnew/3 12 pep-692-using-typeddict-for-more-precise-kwargs-typing672852
Ref: 691672852
Ref: whatsnew/3 12 whatsnew312-pep692672852
Ref: 67a672852
Ref: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa-Footnote-1673595
Ref: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa-Footnote-2673637
Ref: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa-Footnote-3673679
Ref: PEP 692 Utilizzo di TypedDict per una digitazione **kwargs più precisa-Footnote-4673721
Node: PEP 698 Decoratore Override per tipizzazione statica673777
Ref: whatsnew/3 12 pep-698-override-decorator-for-static-typing673992
Ref: 692673992
Ref: whatsnew/3 12 whatsnew312-pep698673992
Ref: 67c673992
Ref: PEP 698 Decoratore Override per tipizzazione statica-Footnote-1675008
Ref: PEP 698 Decoratore Override per tipizzazione statica-Footnote-2675050
Node: Altre modifiche al Linguaggio675106
Ref: whatsnew/3 12 other-language-changes675270
Ref: 693675270
Ref: Altre modifiche al Linguaggio-Footnote-1680406
Ref: Altre modifiche al Linguaggio-Footnote-2680461
Ref: Altre modifiche al Linguaggio-Footnote-3680516
Ref: Altre modifiche al Linguaggio-Footnote-4680571
Ref: Altre modifiche al Linguaggio-Footnote-5680613
Ref: Altre modifiche al Linguaggio-Footnote-6680669
Ref: Altre modifiche al Linguaggio-Footnote-7680711
Ref: Altre modifiche al Linguaggio-Footnote-8680766
Ref: Altre modifiche al Linguaggio-Footnote-9680822
Ref: Altre modifiche al Linguaggio-Footnote-10680877
Ref: Altre modifiche al Linguaggio-Footnote-11680933
Ref: Altre modifiche al Linguaggio-Footnote-12680989
Ref: Altre modifiche al Linguaggio-Footnote-13681046
Ref: Altre modifiche al Linguaggio-Footnote-14681103
Ref: Altre modifiche al Linguaggio-Footnote-15681159
Ref: Altre modifiche al Linguaggio-Footnote-16681202
Ref: Altre modifiche al Linguaggio-Footnote-17681258
Node: Nuovi Moduli681314
Ref: whatsnew/3 12 new-modules681449
Ref: 69e681449
Node: Moduli Migliorati681503
Ref: whatsnew/3 12 improved-modules681623
Ref: 69f681623
Node: array<2>682303
Ref: whatsnew/3 12 array682384
Ref: 6a0682384
Ref: array<2>-Footnote-1682613
Node: asyncio<5>682668
Ref: whatsnew/3 12 asyncio682769
Ref: 6a1682769
Ref: asyncio<5>-Footnote-1684872
Ref: asyncio<5>-Footnote-2684927
Ref: asyncio<5>-Footnote-3684983
Ref: asyncio<5>-Footnote-4685039
Ref: asyncio<5>-Footnote-5685095
Ref: asyncio<5>-Footnote-6685150
Ref: asyncio<5>-Footnote-7685205
Ref: asyncio<5>-Footnote-8685260
Ref: asyncio<5>-Footnote-9685316
Ref: asyncio<5>-Footnote-10685372
Node: calendar<2>685428
Ref: whatsnew/3 12 calendar685524
Ref: 6a9685524
Ref: calendar<2>-Footnote-1685793
Node: csv685849
Ref: whatsnew/3 12 csv685941
Ref: 6ac685941
Node: dis<3>686175
Ref: whatsnew/3 12 dis686268
Ref: 6b1686268
Ref: dis<3>-Footnote-1686910
Ref: dis<3>-Footnote-2686965
Node: fractions<3>687020
Ref: whatsnew/3 12 fractions687129
Ref: 6b4687129
Ref: fractions<3>-Footnote-1687357
Node: importlib resources687413
Ref: whatsnew/3 12 importlib-resources687526
Ref: 6b5687526
Ref: importlib resources-Footnote-1687906
Ref: importlib resources-Footnote-2687961
Node: inspect<2>688017
Ref: whatsnew/3 12 inspect688130
Ref: 6b8688130
Ref: inspect<2>-Footnote-1688955
Ref: inspect<2>-Footnote-2689010
Ref: inspect<2>-Footnote-3689065
Node: itertools<3>689121
Ref: whatsnew/3 12 itertools689225
Ref: 6be689225
Ref: itertools<3>-Footnote-1689490
Node: matematica689545
Ref: whatsnew/3 12 math689644
Ref: 6bf689644
Ref: matematica-Footnote-1690090
Ref: matematica-Footnote-2690146
Node: os<3>690201
Ref: whatsnew/3 12 os690298
Ref: 6c2690298
Ref: os<3>-Footnote-1691715
Ref: os<3>-Footnote-2691770
Ref: os<3>-Footnote-3691825
Ref: os<3>-Footnote-4691881
Node: os path<3>691936
Ref: whatsnew/3 12 os-path692033
Ref: 6ca692033
Ref: os path<3>-Footnote-1692443
Ref: os path<3>-Footnote-2692498
Node: pathlib<6>692554
Ref: whatsnew/3 12 pathlib692657
Ref: 6cd692657
Ref: pathlib<6>-Footnote-1694061
Ref: pathlib<6>-Footnote-2694116
Ref: pathlib<6>-Footnote-3694171
Node: platform<2>694226
Ref: whatsnew/3 12 platform694325
Ref: 6d5694325
Ref: platform<2>-Footnote-1694670
Node: pdb<4>694725
Ref: whatsnew/3 12 pdb694823
Ref: 6d6694823
Ref: pdb<4>-Footnote-1695130
Node: random<2>695186
Ref: whatsnew/3 12 random695282
Ref: 6d7695282
Ref: random<2>-Footnote-1695598
Ref: random<2>-Footnote-2695653
Node: shutil<2>695709
Ref: whatsnew/3 12 shutil695809
Ref: 6da695809
Ref: shutil<2>-Footnote-1697348
Ref: shutil<2>-Footnote-2697403
Ref: shutil<2>-Footnote-3697459
Ref: shutil<2>-Footnote-4697515
Ref: shutil<2>-Footnote-5697571
Node: sqlite3<3>697627
Ref: whatsnew/3 12 sqlite3697728
Ref: 6dd697728
Ref: sqlite3<3>-Footnote-1698748
Ref: sqlite3<3>-Footnote-2698803
Ref: sqlite3<3>-Footnote-3698845
Ref: sqlite3<3>-Footnote-4698900
Ref: sqlite3<3>-Footnote-5698956
Node: statistica699012
Ref: whatsnew/3 12 statistics699110
Ref: 6e3699110
Ref: statistica-Footnote-1699403
Node: sys<3>699458
Ref: whatsnew/3 12 sys699557
Ref: 6e5699557
Ref: sys<3>-Footnote-1701192
Ref: sys<3>-Footnote-2701248
Ref: sys<3>-Footnote-3701303
Ref: sys<3>-Footnote-4701359
Node: tempfile<2>701415
Ref: whatsnew/3 12 tempfile701516
Ref: 6ed701516
Ref: tempfile<2>-Footnote-1701916
Node: threading<2>701971
Ref: whatsnew/3 12 threading702076
Ref: 6ef702076
Ref: threading<2>-Footnote-1702452
Node: tkinter<3>702507
Ref: whatsnew/3 12 tkinter702609
Ref: 6f2702609
Ref: tkinter<3>-Footnote-1703110
Node: tokenize703165
Ref: whatsnew/3 12 tokenize703263
Ref: 6f3703263
Ref: tokenize-Footnote-1703619
Ref: tokenize-Footnote-2703661
Node: types<3>703717
Ref: whatsnew/3 12 types703814
Ref: 6f5703814
Ref: types<3>-Footnote-1704122
Node: typing<4>704178
Ref: whatsnew/3 12 typing704281
Ref: 6f8704281
Ref: whatsnew/3 12 whatsnew-typing-py312704281
Ref: 6f9704281
Ref: typing<4>-Footnote-1707145
Ref: typing<4>-Footnote-2707201
Ref: typing<4>-Footnote-3707256
Ref: typing<4>-Footnote-4707312
Ref: typing<4>-Footnote-5707368
Node: unicodedata<3>707423
Ref: whatsnew/3 12 unicodedata707529
Ref: 6fd707529
Ref: unicodedata<3>-Footnote-1707731
Node: unittest<3>707786
Ref: whatsnew/3 12 unittest707890
Ref: 6fe707890
Ref: unittest<3>-Footnote-1708694
Node: uuid<3>708749
Ref: whatsnew/3 12 uuid708830
Ref: 6ff708830
Ref: uuid<3>-Footnote-1709010
Node: Ottimizzazioni709065
Ref: whatsnew/3 12 optimizations709205
Ref: 700709205
Ref: Ottimizzazioni-Footnote-1710796
Ref: Ottimizzazioni-Footnote-2710838
Ref: Ottimizzazioni-Footnote-3710893
Ref: Ottimizzazioni-Footnote-4710948
Ref: Ottimizzazioni-Footnote-5711004
Ref: Ottimizzazioni-Footnote-6711059
Ref: Ottimizzazioni-Footnote-7711115
Ref: Ottimizzazioni-Footnote-8711157
Ref: Ottimizzazioni-Footnote-9711213
Node: Modifiche al bytecode di CPython711269
Ref: whatsnew/3 12 cpython-bytecode-changes711405
Ref: 704711405
Ref: Modifiche al bytecode di CPython-Footnote-1713492
Ref: Modifiche al bytecode di CPython-Footnote-2713547
Ref: Modifiche al bytecode di CPython-Footnote-3713603
Ref: Modifiche al bytecode di CPython-Footnote-4713658
Ref: Modifiche al bytecode di CPython-Footnote-5713713
Ref: Modifiche al bytecode di CPython-Footnote-6713768
Ref: Modifiche al bytecode di CPython-Footnote-7713824
Ref: Modifiche al bytecode di CPython-Footnote-8713879
Ref: Modifiche al bytecode di CPython-Footnote-9713935
Ref: Modifiche al bytecode di CPython-Footnote-10713977
Ref: Modifiche al bytecode di CPython-Footnote-11714034
Ref: Modifiche al bytecode di CPython-Footnote-12714090
Ref: Modifiche al bytecode di CPython-Footnote-13714133
Ref: Modifiche al bytecode di CPython-Footnote-14714190
Ref: Modifiche al bytecode di CPython-Footnote-15714247
Node: Demos e Tools714304
Ref: whatsnew/3 12 demos-and-tools714435
Ref: 710714435
Ref: Demos e Tools-Footnote-1714901
Ref: Demos e Tools-Footnote-2714949
Ref: Demos e Tools-Footnote-3715004
Ref: Demos e Tools-Footnote-4715052
Node: Deprecato715107
Ref: whatsnew/3 12 deprecated715213
Ref: 711715213
Ref: Deprecato-Footnote-1726701
Ref: Deprecato-Footnote-2726756
Ref: Deprecato-Footnote-3726811
Ref: Deprecato-Footnote-4726866
Ref: Deprecato-Footnote-5726921
Ref: Deprecato-Footnote-6726977
Ref: Deprecato-Footnote-7727033
Ref: Deprecato-Footnote-8727091
Ref: Deprecato-Footnote-9727146
Ref: Deprecato-Footnote-10727202
Ref: Deprecato-Footnote-11727258
Ref: Deprecato-Footnote-12727314
Ref: Deprecato-Footnote-13727371
Ref: Deprecato-Footnote-14727427
Ref: Deprecato-Footnote-15727483
Ref: Deprecato-Footnote-16727539
Ref: Deprecato-Footnote-17727595
Ref: Deprecato-Footnote-18727698
Ref: Deprecato-Footnote-19727755
Ref: Deprecato-Footnote-20727811
Ref: Deprecato-Footnote-21727868
Ref: Deprecato-Footnote-22727925
Ref: Deprecato-Footnote-23727981
Ref: Deprecato-Footnote-24728037
Ref: Deprecato-Footnote-25728093
Ref: Deprecato-Footnote-26728149
Ref: Deprecato-Footnote-27728205
Ref: Deprecato-Footnote-28728261
Ref: Deprecato-Footnote-29728318
Ref: Deprecato-Footnote-30728361
Node: Pending removal in Python 3 13728418
Ref: whatsnew/3 12 pending-removal-in-python-3-13728536
Ref: 720728536
Ref: Pending removal in Python 3 13-Footnote-1729602
Ref: Pending removal in Python 3 13-Footnote-2729644
Ref: Pending removal in Python 3 13-Footnote-3729699
Ref: Pending removal in Python 3 13-Footnote-4729754
Ref: Pending removal in Python 3 13-Footnote-5729809
Ref: Pending removal in Python 3 13-Footnote-6729864
Ref: Pending removal in Python 3 13-Footnote-7729919
Ref: Pending removal in Python 3 13-Footnote-8729974
Ref: Pending removal in Python 3 13-Footnote-9730029
Ref: Pending removal in Python 3 13-Footnote-10730084
Ref: Pending removal in Python 3 13-Footnote-11730140
Node: Pending removal in Python 3 14<3>730196
Ref: whatsnew/3 12 pending-removal-in-python-3-14730356
Ref: 721730356
Ref: Pending removal in Python 3 14<3>-Footnote-1734628
Ref: Pending removal in Python 3 14<3>-Footnote-2734683
Ref: Pending removal in Python 3 14<3>-Footnote-3734738
Ref: Pending removal in Python 3 14<3>-Footnote-4734793
Ref: Pending removal in Python 3 14<3>-Footnote-5734848
Ref: Pending removal in Python 3 14<3>-Footnote-6734904
Ref: Pending removal in Python 3 14<3>-Footnote-7734959
Ref: Pending removal in Python 3 14<3>-Footnote-8735014
Ref: Pending removal in Python 3 14<3>-Footnote-9735070
Ref: Pending removal in Python 3 14<3>-Footnote-10735125
Ref: Pending removal in Python 3 14<3>-Footnote-11735181
Node: Pending removal in Python 3 15<5>735237
Ref: whatsnew/3 12 pending-removal-in-python-3-15735400
Ref: 722735400
Ref: Pending removal in Python 3 15<5>-Footnote-1739957
Ref: Pending removal in Python 3 15<5>-Footnote-2740012
Ref: Pending removal in Python 3 15<5>-Footnote-3740067
Ref: Pending removal in Python 3 15<5>-Footnote-4740122
Ref: Pending removal in Python 3 15<5>-Footnote-5740178
Ref: Pending removal in Python 3 15<5>-Footnote-6740220
Ref: Pending removal in Python 3 15<5>-Footnote-7740276
Node: Pending removal in Python 3 16<5>740332
Ref: whatsnew/3 12 pending-removal-in-python-3-16740495
Ref: 723740495
Ref: Pending removal in Python 3 16<5>-Footnote-1744741
Ref: Pending removal in Python 3 16<5>-Footnote-2744797
Ref: Pending removal in Python 3 16<5>-Footnote-3744853
Ref: Pending removal in Python 3 16<5>-Footnote-4744909
Node: Pending removal in Python 3 17<3>744964
Ref: whatsnew/3 12 pending-removal-in-python-3-17745131
Ref: 724745131
Ref: Pending removal in Python 3 17<3>-Footnote-1748067
Ref: Pending removal in Python 3 17<3>-Footnote-2748125
Ref: Pending removal in Python 3 17<3>-Footnote-3748180
Ref: Pending removal in Python 3 17<3>-Footnote-4748238
Node: Pending removal in future versions<5>748293
Ref: whatsnew/3 12 pending-removal-in-future-versions748418
Ref: 725748418
Ref: Pending removal in future versions<5>-Footnote-1755682
Ref: Pending removal in future versions<5>-Footnote-2755737
Ref: Pending removal in future versions<5>-Footnote-3755793
Ref: Pending removal in future versions<5>-Footnote-4755849
Ref: Pending removal in future versions<5>-Footnote-5755905
Ref: Pending removal in future versions<5>-Footnote-6755960
Ref: Pending removal in future versions<5>-Footnote-7756015
Node: Rimosso756071
Ref: whatsnew/3 12 removed756185
Ref: 726756185
Ref: whatsnew/3 12 whatsnew312-removed756185
Ref: 727756185
Node: asynchat e asyncore756616
Ref: whatsnew/3 12 asynchat-and-asyncore756703
Ref: 728756703
Ref: asynchat e asyncore-Footnote-1757018
Ref: asynchat e asyncore-Footnote-2757060
Node: configparser<4>757115
Ref: whatsnew/3 12 configparser757220
Ref: 729757220
Ref: configparser<4>-Footnote-1757928
Node: distutils757983
Ref: whatsnew/3 12 distutils758078
Ref: 72c758078
Ref: whatsnew/3 12 whatsnew312-removed-distutils758078
Ref: 72d758078
Ref: distutils-Footnote-1758544
Ref: distutils-Footnote-2758586
Node: ensurepip758641
Ref: whatsnew/3 12 ensurepip758728
Ref: 72e758728
Ref: ensurepip-Footnote-1759809
Node: enum<2>759864
Ref: whatsnew/3 12 enum759948
Ref: 72f759948
Ref: enum<2>-Footnote-1760204
Node: ftplib760259
Ref: whatsnew/3 12 ftplib760338
Ref: 730760338
Ref: ftplib-Footnote-1760598
Node: gzip760653
Ref: whatsnew/3 12 gzip760732
Ref: 731760732
Ref: gzip-Footnote-1761169
Node: hashlib761224
Ref: whatsnew/3 12 hashlib761309
Ref: 733761309
Ref: hashlib-Footnote-1761736
Ref: hashlib-Footnote-2761778
Node: importlib<2>761833
Ref: whatsnew/3 12 importlib761917
Ref: 735761917
Ref: importlib<2>-Footnote-1762804
Ref: importlib<2>-Footnote-2762859
Ref: importlib<2>-Footnote-3762914
Ref: importlib<2>-Footnote-4762969
Ref: importlib<2>-Footnote-5763024
Node: imp763079
Ref: whatsnew/3 12 imp763161
Ref: 736763161
Ref: whatsnew/3 12 whatsnew312-removed-imp763161
Ref: 737763161
Ref: imp-Footnote-1767299
Node: io<4>767354
Ref: whatsnew/3 12 io767433
Ref: 740767433
Ref: io<4>-Footnote-1767882
Node: locale<2>767937
Ref: whatsnew/3 12 locale768018
Ref: 742768018
Ref: locale<2>-Footnote-1768291
Node: smtpd768346
Ref: whatsnew/3 12 smtpd768432
Ref: 744768432
Ref: smtpd-Footnote-1768788
Ref: smtpd-Footnote-2768830
Ref: smtpd-Footnote-3768873
Node: sqlite3<4>768928
Ref: whatsnew/3 12 id2769011
Ref: 745769011
Ref: sqlite3<4>-Footnote-1769832
Node: ssl<3>769887
Ref: whatsnew/3 12 ssl769976
Ref: 746769976
Ref: ssl<3>-Footnote-1771106
Ref: ssl<3>-Footnote-2771161
Ref: ssl<3>-Footnote-3771216
Ref: ssl<3>-Footnote-4771272
Node: unittest<4>771327
Ref: whatsnew/3 12 id3771419
Ref: 74a771419
Ref: whatsnew/3 12 unittest-testcase-removed-aliases771547
Ref: 67f771547
Ref: unittest<4>-Footnote-1776234
Node: webbrowser<3>776289
Ref: whatsnew/3 12 webbrowser776396
Ref: 756776396
Ref: webbrowser<3>-Footnote-1776710
Node: xml etree ElementTree776766
Ref: whatsnew/3 12 xml-etree-elementtree776874
Ref: 757776874
Ref: xml etree ElementTree-Footnote-1777345
Node: zipimport<2>777400
Ref: whatsnew/3 12 zipimport777500
Ref: 759777500
Ref: zipimport<2>-Footnote-1777834
Ref: zipimport<2>-Footnote-2777876
Node: Altri777931
Ref: whatsnew/3 12 others778001
Ref: 75a778001
Ref: Altri-Footnote-1778990
Ref: Altri-Footnote-2779044
Ref: Altri-Footnote-3779099
Ref: Altri-Footnote-4779154
Ref: Altri-Footnote-5779209
Node: Porting a Python 3 12779264
Ref: whatsnew/3 12 porting-to-python-3-12779389
Ref: 75b779389
Ref: whatsnew/3 12 whatsnew312-porting-to-python312779389
Ref: 6f4779389
Node: Modifiche nell’API di Python779633
Ref: whatsnew/3 12 changes-in-the-python-api779721
Ref: 75c779721
Ref: Modifiche nell’API di Python-Footnote-1786639
Ref: Modifiche nell’API di Python-Footnote-2786694
Ref: Modifiche nell’API di Python-Footnote-3786749
Ref: Modifiche nell’API di Python-Footnote-4786792
Ref: Modifiche nell’API di Python-Footnote-5786847
Ref: Modifiche nell’API di Python-Footnote-6786902
Ref: Modifiche nell’API di Python-Footnote-7786957
Ref: Modifiche nell’API di Python-Footnote-8787013
Ref: Modifiche nell’API di Python-Footnote-9787055
Ref: Modifiche nell’API di Python-Footnote-10787097
Ref: Modifiche nell’API di Python-Footnote-11787140
Node: Modifiche alla Build787197
Ref: whatsnew/3 12 build-changes787336
Ref: 767787336
Ref: Modifiche alla Build-Footnote-1789219
Ref: Modifiche alla Build-Footnote-2789274
Ref: Modifiche alla Build-Footnote-3789329
Ref: Modifiche alla Build-Footnote-4789384
Ref: Modifiche alla Build-Footnote-5789439
Ref: Modifiche alla Build-Footnote-6789494
Node: Modifiche all’API C789549
Ref: whatsnew/3 12 c-api-changes789658
Ref: 768789658
Node: Nuove Funzionalità<2>789873
Ref: whatsnew/3 12 id4789986
Ref: 769789986
Ref: whatsnew/3 12 whatsnew312-pep697790044
Ref: 677790044
Ref: whatsnew/3 12 whatsnew312-pep683796698
Ref: 678796698
Ref: Nuove Funzionalità<2>-Footnote-1798667
Ref: Nuove Funzionalità<2>-Footnote-2798709
Ref: Nuove Funzionalità<2>-Footnote-3798751
Ref: Nuove Funzionalità<2>-Footnote-4798807
Ref: Nuove Funzionalità<2>-Footnote-5798849
Ref: Nuove Funzionalità<2>-Footnote-6798905
Ref: Nuove Funzionalità<2>-Footnote-7798960
Ref: Nuove Funzionalità<2>-Footnote-8799015
Ref: Nuove Funzionalità<2>-Footnote-9799070
Ref: Nuove Funzionalità<2>-Footnote-10799125
Ref: Nuove Funzionalità<2>-Footnote-11799181
Ref: Nuove Funzionalità<2>-Footnote-12799237
Ref: Nuove Funzionalità<2>-Footnote-13799293
Ref: Nuove Funzionalità<2>-Footnote-14799349
Ref: Nuove Funzionalità<2>-Footnote-15799405
Ref: Nuove Funzionalità<2>-Footnote-16799462
Ref: Nuove Funzionalità<2>-Footnote-17799519
Ref: Nuove Funzionalità<2>-Footnote-18799576
Ref: Nuove Funzionalità<2>-Footnote-19799633
Ref: Nuove Funzionalità<2>-Footnote-20799676
Ref: Nuove Funzionalità<2>-Footnote-21799732
Ref: Nuove Funzionalità<2>-Footnote-22799775
Ref: Nuove Funzionalità<2>-Footnote-23799832
Node: Porting a Python 3 12<2>799889
Ref: whatsnew/3 12 id5800023
Ref: 792800023
Ref: Porting a Python 3 12<2>-Footnote-1808043
Ref: Porting a Python 3 12<2>-Footnote-2808098
Ref: Porting a Python 3 12<2>-Footnote-3808153
Ref: Porting a Python 3 12<2>-Footnote-4808208
Ref: Porting a Python 3 12<2>-Footnote-5808263
Ref: Porting a Python 3 12<2>-Footnote-6808318
Ref: Porting a Python 3 12<2>-Footnote-7808373
Ref: Porting a Python 3 12<2>-Footnote-8808429
Node: Deprecato<2>808485
Ref: whatsnew/3 12 id6808607
Ref: 7aa808607
Ref: Deprecato<2>-Footnote-1814127
Ref: Deprecato<2>-Footnote-2814169
Ref: Deprecato<2>-Footnote-3814225
Ref: Deprecato<2>-Footnote-4814280
Ref: Deprecato<2>-Footnote-5814335
Ref: Deprecato<2>-Footnote-6814390
Ref: Deprecato<2>-Footnote-7814446
Ref: Deprecato<2>-Footnote-8814502
Node: Pending removal in Python 3 14<4>814558
Ref: whatsnew/3 12 id7814682
Ref: 7b4814682
Ref: Pending removal in Python 3 14<4>-Footnote-1814996
Ref: Pending removal in Python 3 14<4>-Footnote-2815038
Ref: Pending removal in Python 3 14<4>-Footnote-3815094
Node: Pending removal in Python 3 15<6>815149
Ref: whatsnew/3 12 id8815315
Ref: 7b5815315
Ref: Pending removal in Python 3 15<6>-Footnote-1821972
Ref: Pending removal in Python 3 15<6>-Footnote-2822025
Node: Pending removal in Python 3 16<6>822078
Ref: whatsnew/3 12 id9822248
Ref: 7b6822248
Node: Pending removal in future versions<6>822371
Ref: whatsnew/3 12 id10822499
Ref: 7b7822499
Node: Rimosso<2>824333
Ref: whatsnew/3 12 id11824422
Ref: 7b8824422
Ref: Rimosso<2>-Footnote-1825339
Ref: Rimosso<2>-Footnote-2825394
Ref: Rimosso<2>-Footnote-3825436
Node: What’s New In Python 3 11825491
Ref: whatsnew/3 11 doc825639
Ref: 7b9825639
Ref: whatsnew/3 11 translation-repo825639
Ref: 7ba825639
Ref: whatsnew/3 11 what-s-new-in-python-3-11825639
Ref: 7bb825639
Node: Summary – Release highlights<2>826681
Ref: whatsnew/3 11 summary-release-highlights826802
Ref: 7bc826802
Ref: whatsnew/3 11 whatsnew311-summary826802
Ref: 7bd826802
Ref: Summary – Release highlights<2>-Footnote-1828330
Ref: Summary – Release highlights<2>-Footnote-2828372
Ref: Summary – Release highlights<2>-Footnote-3828397
Ref: Summary – Release highlights<2>-Footnote-4828439
Ref: Summary – Release highlights<2>-Footnote-5828481
Node: New Features<3>828523
Ref: whatsnew/3 11 new-features828687
Ref: 7cd828687
Ref: whatsnew/3 11 whatsnew311-features828687
Ref: 7ce828687
Node: PEP 657 Fine-grained error locations in tracebacks829097
Ref: whatsnew/3 11 pep-657-fine-grained-error-locations-in-tracebacks829244
Ref: 7cf829244
Ref: whatsnew/3 11 whatsnew311-pep657829244
Ref: 7c1829244
Ref: PEP 657 Fine-grained error locations in tracebacks-Footnote-1832015
Ref: PEP 657 Fine-grained error locations in tracebacks-Footnote-2832057
Node: PEP 654 Exception Groups and except*832122
Ref: whatsnew/3 11 pep-654-exception-groups-and-except832323
Ref: 7d5832323
Ref: whatsnew/3 11 whatsnew311-pep654832323
Ref: 7bf832323
Ref: PEP 654 Exception Groups and except*-Footnote-1832991
Ref: PEP 654 Exception Groups and except*-Footnote-2833033
Ref: PEP 654 Exception Groups and except*-Footnote-3833075
Node: PEP 678 Exceptions can be enriched with notes833140
Ref: whatsnew/3 11 pep-678-exceptions-can-be-enriched-with-notes833327
Ref: 7d6833327
Ref: whatsnew/3 11 whatsnew311-pep678833327
Ref: 7c0833327
Ref: PEP 678 Exceptions can be enriched with notes-Footnote-1833840
Ref: PEP 678 Exceptions can be enriched with notes-Footnote-2833882
Node: Windows py exe launcher improvements833947
Ref: whatsnew/3 11 whatsnew311-windows-launcher834089
Ref: 7d9834089
Ref: whatsnew/3 11 windows-py-exe-launcher-improvements834089
Ref: 7da834089
Ref: whatsnew/3 11 new-feat-related-type-hints-311835402
Ref: 7dc835402
Ref: Windows py exe launcher improvements-Footnote-1835440
Ref: Windows py exe launcher improvements-Footnote-2835482
Node: New Features Related to Type Hints835513
Ref: whatsnew/3 11 new-features-related-to-type-hints835669
Ref: 7dd835669
Ref: whatsnew/3 11 whatsnew311-typing-features835669
Ref: 7de835669
Ref: New Features Related to Type Hints-Footnote-1836325
Node: PEP 646 Variadic generics836367
Ref: whatsnew/3 11 pep-646-variadic-generics836542
Ref: 7df836542
Ref: whatsnew/3 11 whatsnew311-pep646836542
Ref: 7c5836542
Ref: PEP 646 Variadic generics-Footnote-1837520
Ref: PEP 646 Variadic generics-Footnote-2837562
Ref: PEP 646 Variadic generics-Footnote-3837604
Ref: PEP 646 Variadic generics-Footnote-4837646
Node: PEP 655 Marking individual TypedDict items as required or not-required837711
Ref: whatsnew/3 11 pep-655-marking-individual-typeddict-items-as-required-or-not-required837912
Ref: 7e0837912
Ref: whatsnew/3 11 whatsnew311-pep655837912
Ref: 7c6837912
Ref: PEP 655 Marking individual TypedDict items as required or not-required-Footnote-1839132
Ref: PEP 655 Marking individual TypedDict items as required or not-required-Footnote-2839174
Node: PEP 673 Self type839239
Ref: whatsnew/3 11 pep-673-self-type839452
Ref: 7e3839452
Ref: whatsnew/3 11 whatsnew311-pep673839452
Ref: 7c7839452
Ref: PEP 673 Self type-Footnote-1840496
Ref: PEP 673 Self type-Footnote-2840577
Ref: PEP 673 Self type-Footnote-3840619
Node: PEP 675 Arbitrary literal string type840684
Ref: whatsnew/3 11 pep-675-arbitrary-literal-string-type840856
Ref: 7e6840856
Ref: whatsnew/3 11 whatsnew311-pep675840856
Ref: 7c8840856
Ref: PEP 675 Arbitrary literal string type-Footnote-1842250
Ref: PEP 675 Arbitrary literal string type-Footnote-2842292
Node: PEP 681 Data class transforms842357
Ref: whatsnew/3 11 pep-681-data-class-transforms842541
Ref: 7e8842541
Ref: whatsnew/3 11 whatsnew311-pep681842541
Ref: 7c9842541
Ref: PEP 681 Data class transforms-Footnote-1843572
Ref: PEP 681 Data class transforms-Footnote-2843614
Node: PEP 563 may not be the future843669
Ref: whatsnew/3 11 pep-563-may-not-be-the-future843807
Ref: 7e9843807
Ref: whatsnew/3 11 whatsnew311-pep563-deferred843807
Ref: 7ea843807
Ref: PEP 563 may not be the future-Footnote-1844202
Ref: PEP 563 may not be the future-Footnote-2844244
Node: Other Language Changes<2>844355
Ref: whatsnew/3 11 other-language-changes844532
Ref: 7eb844532
Ref: whatsnew/3 11 whatsnew311-other-lang-changes844532
Ref: 7ec844532
Ref: whatsnew/3 11 whatsnew311-pythonsafepath846341
Ref: 7c4846341
Ref: Other Language Changes<2>-Footnote-1847689
Ref: Other Language Changes<2>-Footnote-2847754
Ref: Other Language Changes<2>-Footnote-3847819
Ref: Other Language Changes<2>-Footnote-4847884
Ref: Other Language Changes<2>-Footnote-5847949
Ref: Other Language Changes<2>-Footnote-6848004
Ref: Other Language Changes<2>-Footnote-7848069
Ref: Other Language Changes<2>-Footnote-8848124
Ref: Other Language Changes<2>-Footnote-9848166
Ref: Other Language Changes<2>-Footnote-10848221
Node: Other CPython Implementation Changes848277
Ref: whatsnew/3 11 other-cpython-implementation-changes848434
Ref: 7fc848434
Ref: whatsnew/3 11 whatsnew311-other-implementation-changes848434
Ref: 7fd848434
Ref: Other CPython Implementation Changes-Footnote-1851688
Ref: Other CPython Implementation Changes-Footnote-2851753
Ref: Other CPython Implementation Changes-Footnote-3851795
Ref: Other CPython Implementation Changes-Footnote-4851860
Ref: Other CPython Implementation Changes-Footnote-5851925
Ref: Other CPython Implementation Changes-Footnote-6851990
Ref: Other CPython Implementation Changes-Footnote-7852055
Ref: Other CPython Implementation Changes-Footnote-8852120
Node: New Modules<2>852176
Ref: whatsnew/3 11 new-modules852327
Ref: 80d852327
Ref: whatsnew/3 11 whatsnew311-new-modules852327
Ref: 80e852327
Ref: New Modules<2>-Footnote-1852676
Ref: New Modules<2>-Footnote-2852701
Ref: New Modules<2>-Footnote-3852743
Ref: New Modules<2>-Footnote-4852808
Ref: New Modules<2>-Footnote-5852850
Node: Improved Modules<2>852915
Ref: whatsnew/3 11 improved-modules853046
Ref: 80f853046
Ref: whatsnew/3 11 whatsnew311-improved-modules853046
Ref: 810853046
Node: asyncio<6>853850
Ref: whatsnew/3 11 asyncio853935
Ref: 811853935
Ref: whatsnew/3 11 whatsnew311-asyncio853935
Ref: 812853935
Ref: asyncio<6>-Footnote-1855853
Ref: asyncio<6>-Footnote-2855908
Ref: asyncio<6>-Footnote-3855963
Ref: asyncio<6>-Footnote-4856018
Ref: asyncio<6>-Footnote-5856073
Ref: asyncio<6>-Footnote-6856138
Node: contextlib856203
Ref: whatsnew/3 11 contextlib856308
Ref: 81f856308
Ref: whatsnew/3 11 whatsnew311-contextlib856308
Ref: 820856308
Ref: contextlib-Footnote-1856623
Node: dataclasses856688
Ref: whatsnew/3 11 dataclasses856794
Ref: 823856794
Ref: whatsnew/3 11 whatsnew311-dataclasses856794
Ref: 824856794
Ref: dataclasses-Footnote-1857136
Node: datetime<2>857201
Ref: whatsnew/3 11 datetime857304
Ref: 826857304
Ref: whatsnew/3 11 whatsnew311-datetime857304
Ref: 827857304
Ref: datetime<2>-Footnote-1857843
Ref: datetime<2>-Footnote-2857898
Node: enum<3>857953
Ref: whatsnew/3 11 enum858050
Ref: 82c858050
Ref: whatsnew/3 11 whatsnew311-enum858050
Ref: 82d858050
Node: fcntl860696
Ref: whatsnew/3 11 fcntl860794
Ref: 846860794
Ref: whatsnew/3 11 whatsnew311-fcntl860794
Ref: 847860794
Node: fractions<4>861029
Ref: whatsnew/3 11 fractions861132
Ref: 848861132
Ref: whatsnew/3 11 whatsnew311-fractions861132
Ref: 849861132
Ref: fractions<4>-Footnote-1861550
Ref: fractions<4>-Footnote-2861592
Ref: fractions<4>-Footnote-3861657
Node: functools<2>861722
Ref: whatsnew/3 11 functools861827
Ref: 84a861827
Ref: whatsnew/3 11 whatsnew311-functools861827
Ref: 84b861827
Ref: functools<2>-Footnote-1862899
Node: gzip<2>862964
Ref: whatsnew/3 11 gzip863067
Ref: 84d863067
Ref: whatsnew/3 11 whatsnew311-gzip863067
Ref: 84e863067
Ref: gzip<2>-Footnote-1863779
Node: hashlib<2>863835
Ref: whatsnew/3 11 hashlib863942
Ref: 851863942
Ref: whatsnew/3 11 whatsnew311-hashlib863942
Ref: 852863942
Ref: hashlib<2>-Footnote-1864765
Ref: hashlib<2>-Footnote-2864797
Ref: hashlib<2>-Footnote-3864862
Ref: hashlib<2>-Footnote-4864927
Node: IDLE and idlelib864982
Ref: whatsnew/3 11 idle-and-idlelib865092
Ref: 856865092
Ref: whatsnew/3 11 whatsnew311-idle865092
Ref: 857865092
Ref: IDLE and idlelib-Footnote-1865426
Ref: IDLE and idlelib-Footnote-2865491
Node: inspect<3>865546
Ref: whatsnew/3 11 inspect865655
Ref: 858865655
Ref: whatsnew/3 11 whatsnew311-inspect865655
Ref: 859865655
Ref: inspect<3>-Footnote-1866742
Ref: inspect<3>-Footnote-2866807
Ref: inspect<3>-Footnote-3866872
Ref: inspect<3>-Footnote-4866914
Node: locale<3>866969
Ref: whatsnew/3 11 locale867069
Ref: 865867069
Ref: whatsnew/3 11 whatsnew311-locale867069
Ref: 866867069
Node: logging867296
Ref: whatsnew/3 11 logging867393
Ref: 868867393
Ref: whatsnew/3 11 whatsnew311-logging867393
Ref: 869867393
Ref: logging-Footnote-1868052
Ref: logging-Footnote-2868107
Node: math<3>868162
Ref: whatsnew/3 11 math868261
Ref: 86f868261
Ref: whatsnew/3 11 whatsnew311-math868261
Ref: 870868261
Ref: math<3>-Footnote-1869034
Ref: math<3>-Footnote-2869099
Ref: math<3>-Footnote-3869164
Ref: math<3>-Footnote-4869229
Node: operator<2>869294
Ref: whatsnew/3 11 operator869391
Ref: 875869391
Ref: whatsnew/3 11 whatsnew311-operator869391
Ref: 876869391
Ref: operator<2>-Footnote-1869653
Node: os<4>869718
Ref: whatsnew/3 11 os869818
Ref: 877869818
Ref: whatsnew/3 11 whatsnew311-os869818
Ref: 878869818
Ref: os<4>-Footnote-1870067
Node: pathlib<7>870132
Ref: whatsnew/3 11 pathlib870226
Ref: 879870226
Ref: whatsnew/3 11 whatsnew311-pathlib870226
Ref: 87a870226
Ref: pathlib<7>-Footnote-1870547
Ref: pathlib<7>-Footnote-2870612
Node: re<4>870677
Ref: whatsnew/3 11 re870775
Ref: 87d870775
Ref: whatsnew/3 11 whatsnew311-re870775
Ref: 87e870775
Ref: re<4>-Footnote-1871077
Node: shutil<3>871143
Ref: whatsnew/3 11 shutil871240
Ref: 87f871240
Ref: whatsnew/3 11 whatsnew311-shutil871240
Ref: 880871240
Ref: shutil<3>-Footnote-1871434
Node: socket<2>871499
Ref: whatsnew/3 11 socket871601
Ref: 881871601
Ref: whatsnew/3 11 whatsnew311-socket871601
Ref: 882871601
Ref: socket<2>-Footnote-1872014
Ref: socket<2>-Footnote-2872079
Node: sqlite3<5>872144
Ref: whatsnew/3 11 sqlite3872243
Ref: 884872243
Ref: whatsnew/3 11 whatsnew311-sqlite3872243
Ref: 885872243
Ref: sqlite3<5>-Footnote-1874587
Ref: sqlite3<5>-Footnote-2874652
Ref: sqlite3<5>-Footnote-3874717
Ref: sqlite3<5>-Footnote-4874782
Ref: sqlite3<5>-Footnote-5874847
Ref: sqlite3<5>-Footnote-6874912
Ref: sqlite3<5>-Footnote-7874977
Ref: sqlite3<5>-Footnote-8875042
Ref: sqlite3<5>-Footnote-9875107
Ref: sqlite3<5>-Footnote-10875172
Ref: sqlite3<5>-Footnote-11875238
Node: string875304
Ref: whatsnew/3 11 string875400
Ref: 894875400
Ref: whatsnew/3 11 whatsnew311-string875400
Ref: 895875400
Ref: string-Footnote-1875725
Node: sys<4>875780
Ref: whatsnew/3 11 sys875878
Ref: 899875878
Ref: whatsnew/3 11 whatsnew311-sys875878
Ref: 89a875878
Ref: sys<4>-Footnote-1876571
Ref: sys<4>-Footnote-2876636
Ref: sys<4>-Footnote-3876701
Node: sysconfig<2>876756
Ref: whatsnew/3 11 sysconfig876859
Ref: 89e876859
Ref: whatsnew/3 11 whatsnew311-sysconfig876859
Ref: 89f876859
Ref: sysconfig<2>-Footnote-1877672
Node: tempfile<3>877737
Ref: whatsnew/3 11 tempfile877846
Ref: 8a1877846
Ref: whatsnew/3 11 whatsnew311-tempfile877846
Ref: 8a2877846
Ref: tempfile<3>-Footnote-1878255
Node: threading<3>878310
Ref: whatsnew/3 11 threading878414
Ref: 8a6878414
Ref: whatsnew/3 11 whatsnew311-threading878414
Ref: 8a7878414
Ref: threading<3>-Footnote-1878919
Node: time<2>878984
Ref: whatsnew/3 11 time879087
Ref: 8ab879087
Ref: whatsnew/3 11 whatsnew311-time879087
Ref: 8ac879087
Ref: time<2>-Footnote-1879888
Ref: time<2>-Footnote-2879953
Ref: time<2>-Footnote-3880050
Ref: time<2>-Footnote-4880115
Node: tkinter<4>880180
Ref: whatsnew/3 11 tkinter880283
Ref: 8ae880283
Ref: whatsnew/3 11 whatsnew311-tkinter880283
Ref: 8af880283
Ref: tkinter<4>-Footnote-1880566
Node: traceback<2>880621
Ref: whatsnew/3 11 traceback880726
Ref: 8b1880726
Ref: whatsnew/3 11 whatsnew311-traceback880726
Ref: 8b2880726
Ref: traceback<2>-Footnote-1881218
Ref: traceback<2>-Footnote-2881283
Node: typing<5>881348
Ref: whatsnew/3 11 typing881457
Ref: 8b5881457
Ref: whatsnew/3 11 whatsnew311-typing881457
Ref: 8b6881457
Ref: typing<5>-Footnote-1884749
Ref: typing<5>-Footnote-2884804
Ref: typing<5>-Footnote-3884859
Ref: typing<5>-Footnote-4884914
Ref: typing<5>-Footnote-5884969
Ref: typing<5>-Footnote-6885034
Ref: typing<5>-Footnote-7885089
Ref: typing<5>-Footnote-8885144
Ref: typing<5>-Footnote-9885199
Ref: typing<5>-Footnote-10885254
Ref: typing<5>-Footnote-11885310
Ref: typing<5>-Footnote-12885366
Ref: typing<5>-Footnote-13885422
Ref: typing<5>-Footnote-14885478
Ref: typing<5>-Footnote-15885534
Node: unicodedata<4>885590
Ref: whatsnew/3 11 unicodedata885698
Ref: 8c5885698
Ref: whatsnew/3 11 whatsnew311-unicodedata885698
Ref: 8c6885698
Ref: unicodedata<4>-Footnote-1885897
Node: unittest<5>885962
Ref: whatsnew/3 11 unittest886068
Ref: 8c7886068
Ref: whatsnew/3 11 whatsnew311-unittest886068
Ref: 8c8886068
Ref: unittest<5>-Footnote-1886470
Node: venv<2>886535
Ref: whatsnew/3 11 venv886638
Ref: 8cd886638
Ref: whatsnew/3 11 whatsnew311-venv886638
Ref: 8ce886638
Ref: venv<2>-Footnote-1887261
Node: warnings<2>887326
Ref: whatsnew/3 11 warnings887428
Ref: 8cf887428
Ref: whatsnew/3 11 whatsnew311-warnings887428
Ref: 8d0887428
Ref: warnings<2>-Footnote-1887759
Node: zipfile<2>887824
Ref: whatsnew/3 11 whatsnew311-zipfile887910
Ref: 8d2887910
Ref: whatsnew/3 11 zipfile887910
Ref: 8d3887910
Ref: zipfile<2>-Footnote-1888501
Ref: zipfile<2>-Footnote-2888566
Ref: zipfile<2>-Footnote-3888621
Node: Optimizations<3>888676
Ref: whatsnew/3 11 optimizations888807
Ref: 8da888807
Ref: whatsnew/3 11 whatsnew311-optimizations888807
Ref: 8db888807
Ref: Optimizations<3>-Footnote-1891219
Ref: Optimizations<3>-Footnote-2891284
Ref: Optimizations<3>-Footnote-3891339
Ref: Optimizations<3>-Footnote-4891394
Ref: Optimizations<3>-Footnote-5891449
Ref: Optimizations<3>-Footnote-6891514
Ref: Optimizations<3>-Footnote-7891569
Ref: Optimizations<3>-Footnote-8891634
Ref: Optimizations<3>-Footnote-9891689
Node: Faster CPython891754
Ref: whatsnew/3 11 faster-cpython891893
Ref: 8e6891893
Ref: whatsnew/3 11 whatsnew311-faster-cpython891893
Ref: 7be891893
Ref: Faster CPython-Footnote-1892478
Ref: Faster CPython-Footnote-2892544
Node: Faster Startup892592
Ref: whatsnew/3 11 faster-startup892680
Ref: 8e9892680
Ref: whatsnew/3 11 whatsnew311-faster-startup892680
Ref: 8e7892680
Node: Frozen imports / Static code objects892778
Ref: whatsnew/3 11 frozen-imports-static-code-objects892865
Ref: 8ea892865
Ref: whatsnew/3 11 whatsnew311-faster-imports892865
Ref: 8eb892865
Node: Faster Runtime893697
Ref: whatsnew/3 11 faster-runtime893798
Ref: 8ed893798
Ref: whatsnew/3 11 whatsnew311-faster-runtime893798
Ref: 8e8893798
Node: Cheaper lazy Python frames894037
Ref: whatsnew/3 11 cheaper-lazy-python-frames894152
Ref: 8ee894152
Ref: whatsnew/3 11 whatsnew311-lazy-python-frames894152
Ref: 8ef894152
Ref: whatsnew/3 11 inline-calls895095
Ref: 8f3895095
Ref: Cheaper lazy Python frames-Footnote-1895133
Node: Inlined Python function calls895198
Ref: whatsnew/3 11 inlined-python-function-calls895363
Ref: 8f4895363
Ref: whatsnew/3 11 whatsnew311-inline-calls895363
Ref: 8f5895363
Ref: Inlined Python function calls-Footnote-1896317
Node: PEP 659 Specializing Adaptive Interpreter896382
Ref: whatsnew/3 11 pep-659-specializing-adaptive-interpreter896512
Ref: 8f6896512
Ref: whatsnew/3 11 whatsnew311-pep659896512
Ref: 4a0896512
Ref: PEP 659 Specializing Adaptive Interpreter-Footnote-1903922
Ref: PEP 659 Specializing Adaptive Interpreter-Footnote-2903964
Ref: PEP 659 Specializing Adaptive Interpreter-Footnote-3904006
Ref: PEP 659 Specializing Adaptive Interpreter-Footnote-4904131
Node: Misc904356
Ref: whatsnew/3 11 misc904446
Ref: 8f7904446
Ref: whatsnew/3 11 whatsnew311-faster-cpython-misc904446
Ref: 8f8904446
Ref: Misc-Footnote-1905459
Ref: Misc-Footnote-2905524
Ref: Misc-Footnote-3905589
Ref: Misc-Footnote-4905654
Ref: Misc-Footnote-5905719
Ref: Misc-Footnote-6905790
Node: FAQ905845
Ref: whatsnew/3 11 faq905926
Ref: 8fa905926
Ref: whatsnew/3 11 whatsnew311-faster-cpython-faq905926
Ref: 8fb905926
Node: How should I write my code to utilize these speedups?906221
Ref: whatsnew/3 11 faster-cpython-faq-my-code906357
Ref: 8fc906357
Ref: whatsnew/3 11 how-should-i-write-my-code-to-utilize-these-speedups906357
Ref: 8fd906357
Node: Will CPython 3 11 use more memory?906652
Ref: whatsnew/3 11 faster-cpython-faq-memory906843
Ref: 8fe906843
Ref: whatsnew/3 11 will-cpython-3-11-use-more-memory906843
Ref: 8ff906843
Node: I don’t see any speedups in my workload Why?907106
Ref: whatsnew/3 11 faster-cpython-ymmv907268
Ref: 900907268
Ref: whatsnew/3 11 i-don-t-see-any-speedups-in-my-workload-why907268
Ref: 901907268
Node: Is there a JIT compiler?907858
Ref: whatsnew/3 11 faster-cpython-jit907977
Ref: 902907977
Ref: whatsnew/3 11 is-there-a-jit-compiler907977
Ref: 903907977
Node: About908097
Ref: whatsnew/3 11 about908165
Ref: 904908165
Ref: whatsnew/3 11 whatsnew311-faster-cpython-about908165
Ref: 905908165
Node: CPython bytecode changes<2>908474
Ref: whatsnew/3 11 cpython-bytecode-changes908610
Ref: 907908610
Ref: whatsnew/3 11 whatsnew311-bytecode-changes908610
Ref: 908908610
Node: New opcodes909157
Ref: whatsnew/3 11 new-opcodes909257
Ref: 90a909257
Ref: whatsnew/3 11 whatsnew311-added-opcodes909257
Ref: 90b909257
Ref: New opcodes-Footnote-1910039
Node: Replaced opcodes910081
Ref: whatsnew/3 11 replaced-opcodes910213
Ref: 914910213
Ref: whatsnew/3 11 whatsnew311-replaced-opcodes910213
Ref: 915910213
Ref: whatsnew/3 11 whatsnew311-changed-opcodes912932
Ref: 91c912932
Ref: whatsnew/3 11 whatsnew311-removed-opcodes912932
Ref: 91d912932
Ref: Replaced opcodes-Footnote-1912968
Node: Changed/removed opcodes913186
Ref: whatsnew/3 11 changed-removed-opcodes913298
Ref: 91e913298
Ref: whatsnew/3 11 whatsnew311-changed-removed-opcodes913298
Ref: 91f913298
Ref: whatsnew/3 11 whatsnew311-deprecated913886
Ref: 922913886
Ref: Changed/removed opcodes-Footnote-1913923
Node: Deprecated<2>913978
Ref: whatsnew/3 11 deprecated914130
Ref: 923914130
Ref: whatsnew/3 11 whatsnew311-python-api-deprecated914130
Ref: 924914130
Ref: whatsnew/3 11 whatsnew311-deprecated-language914292
Ref: 926914292
Node: Language/Builtins914358
Ref: whatsnew/3 11 language-builtins914441
Ref: 927914441
Ref: whatsnew/3 11 whatsnew311-deprecated-builtins914441
Ref: 928914441
Ref: Language/Builtins-Footnote-1915664
Ref: Language/Builtins-Footnote-2915729
Ref: Language/Builtins-Footnote-3915784
Ref: Language/Builtins-Footnote-4915839
Node: Modules915904
Ref: whatsnew/3 11 modules916012
Ref: 929916012
Ref: whatsnew/3 11 whatsnew311-deprecated-modules916012
Ref: 92a916012
Ref: whatsnew/3 11 whatsnew311-pep594916047
Ref: 7ca916047
Ref: Modules-Footnote-1918257
Ref: Modules-Footnote-2918299
Ref: Modules-Footnote-3918364
Ref: Modules-Footnote-4918419
Ref: Modules-Footnote-5918484
Ref: Modules-Footnote-6918526
Ref: Modules-Footnote-7918591
Node: Standard Library918656
Ref: whatsnew/3 11 standard-library918738
Ref: 92b918738
Ref: whatsnew/3 11 whatsnew311-deprecated-stdlib918738
Ref: 92c918738
Ref: whatsnew/3 11 whatsnew311-pending-removal923595
Ref: 931923595
Ref: Standard Library-Footnote-1923632
Ref: Standard Library-Footnote-2923697
Ref: Standard Library-Footnote-3923762
Ref: Standard Library-Footnote-4923817
Ref: Standard Library-Footnote-5923872
Ref: Standard Library-Footnote-6923927
Ref: Standard Library-Footnote-7923982
Ref: Standard Library-Footnote-8924047
Ref: Standard Library-Footnote-9924102
Ref: Standard Library-Footnote-10924157
Ref: Standard Library-Footnote-11924223
Ref: Standard Library-Footnote-12924288
Node: Pending Removal in Python 3 12924344
Ref: whatsnew/3 11 pending-removal-in-python-3-12924479
Ref: 932924479
Ref: whatsnew/3 11 whatsnew311-python-api-pending-removal924479
Ref: 933924479
Ref: whatsnew/3 11 whatsnew311-removed930117
Ref: 937930117
Node: Removed<2>930117
Ref: whatsnew/3 11 removed930261
Ref: 938930261
Ref: whatsnew/3 11 whatsnew311-python-api-removed930261
Ref: 939930261
Ref: whatsnew/3 11 whatsnew311-porting934926
Ref: 945934926
Ref: Removed<2>-Footnote-1934963
Ref: Removed<2>-Footnote-2935028
Ref: Removed<2>-Footnote-3935093
Ref: Removed<2>-Footnote-4935158
Ref: Removed<2>-Footnote-5935223
Ref: Removed<2>-Footnote-6935288
Ref: Removed<2>-Footnote-7935353
Ref: Removed<2>-Footnote-8935418
Ref: Removed<2>-Footnote-9935483
Ref: Removed<2>-Footnote-10935548
Ref: Removed<2>-Footnote-11935614
Ref: Removed<2>-Footnote-12935680
Ref: Removed<2>-Footnote-13935746
Ref: Removed<2>-Footnote-14935812
Ref: Removed<2>-Footnote-15935854
Node: Porting to Python 3 11935908
Ref: whatsnew/3 11 porting-to-python-3-11936038
Ref: 946936038
Ref: whatsnew/3 11 whatsnew311-python-api-porting936038
Ref: 947936038
Ref: Porting to Python 3 11-Footnote-1939083
Ref: Porting to Python 3 11-Footnote-2939148
Ref: Porting to Python 3 11-Footnote-3939203
Ref: Porting to Python 3 11-Footnote-4939268
Ref: Porting to Python 3 11-Footnote-5939333
Ref: Porting to Python 3 11-Footnote-6939398
Ref: Porting to Python 3 11-Footnote-7939463
Ref: Porting to Python 3 11-Footnote-8939528
Node: Build Changes<2>939593
Ref: whatsnew/3 11 build-changes939729
Ref: 951939729
Ref: whatsnew/3 11 whatsnew311-build-changes939729
Ref: 952939729
Ref: Build Changes<2>-Footnote-1943963
Ref: Build Changes<2>-Footnote-2944005
Ref: Build Changes<2>-Footnote-3944054
Ref: Build Changes<2>-Footnote-4944087
Ref: Build Changes<2>-Footnote-5944119
Ref: Build Changes<2>-Footnote-6944145
Ref: Build Changes<2>-Footnote-7944174
Ref: Build Changes<2>-Footnote-8944229
Ref: Build Changes<2>-Footnote-9944284
Ref: Build Changes<2>-Footnote-10944339
Ref: Build Changes<2>-Footnote-11944383
Ref: Build Changes<2>-Footnote-12944467
Ref: Build Changes<2>-Footnote-13944533
Ref: Build Changes<2>-Footnote-14944599
Ref: Build Changes<2>-Footnote-15944665
Ref: Build Changes<2>-Footnote-16944713
Ref: Build Changes<2>-Footnote-17944779
Ref: Build Changes<2>-Footnote-18944845
Ref: Build Changes<2>-Footnote-19944873
Ref: Build Changes<2>-Footnote-20944939
Ref: Build Changes<2>-Footnote-21945002
Ref: Build Changes<2>-Footnote-22945030
Ref: Build Changes<2>-Footnote-23945096
Ref: Build Changes<2>-Footnote-24945162
Ref: Build Changes<2>-Footnote-25945228
Ref: Build Changes<2>-Footnote-26945294
Ref: Build Changes<2>-Footnote-27945344
Ref: Build Changes<2>-Footnote-28945410
Ref: Build Changes<2>-Footnote-29945476
Ref: Build Changes<2>-Footnote-30945542
Ref: Build Changes<2>-Footnote-31945608
Ref: Build Changes<2>-Footnote-32945674
Ref: Build Changes<2>-Footnote-33945740
Node: C API Changes<2>945806
Ref: whatsnew/3 11 c-api-changes945945
Ref: 955945945
Ref: whatsnew/3 11 whatsnew311-c-api945945
Ref: 956945945
Node: New Features<4>946205
Ref: whatsnew/3 11 id5946307
Ref: 957946307
Ref: whatsnew/3 11 whatsnew311-c-api-new-features946307
Ref: 958946307
Ref: New Features<4>-Footnote-1949161
Ref: New Features<4>-Footnote-2949226
Ref: New Features<4>-Footnote-3949291
Ref: New Features<4>-Footnote-4949356
Ref: New Features<4>-Footnote-5949421
Ref: New Features<4>-Footnote-6949486
Ref: New Features<4>-Footnote-7949551
Ref: New Features<4>-Footnote-8949616
Ref: New Features<4>-Footnote-9949681
Node: Porting to Python 3 11<2>949736
Ref: whatsnew/3 11 id6949860
Ref: 979949860
Ref: whatsnew/3 11 whatsnew311-c-api-porting949860
Ref: 948949860
Ref: whatsnew/3 11 whatsnew311-pep670949925
Ref: 7cc949925
Ref: whatsnew/3 11 pyframeobject-3-11-hiding957342
Ref: 98c957342
Ref: Porting to Python 3 11<2>-Footnote-1963299
Ref: Porting to Python 3 11<2>-Footnote-2963362
Ref: Porting to Python 3 11<2>-Footnote-3963404
Ref: Porting to Python 3 11<2>-Footnote-4963459
Ref: Porting to Python 3 11<2>-Footnote-5963524
Ref: Porting to Python 3 11<2>-Footnote-6963589
Ref: Porting to Python 3 11<2>-Footnote-7963654
Ref: Porting to Python 3 11<2>-Footnote-8963696
Ref: Porting to Python 3 11<2>-Footnote-9963761
Ref: Porting to Python 3 11<2>-Footnote-10963816
Ref: Porting to Python 3 11<2>-Footnote-11963872
Ref: Porting to Python 3 11<2>-Footnote-12963938
Ref: Porting to Python 3 11<2>-Footnote-13963981
Ref: Porting to Python 3 11<2>-Footnote-14964047
Ref: Porting to Python 3 11<2>-Footnote-15964113
Ref: Porting to Python 3 11<2>-Footnote-16964179
Ref: Porting to Python 3 11<2>-Footnote-17964245
Ref: Porting to Python 3 11<2>-Footnote-18964311
Ref: Porting to Python 3 11<2>-Footnote-19964377
Ref: Porting to Python 3 11<2>-Footnote-20964433
Ref: Porting to Python 3 11<2>-Footnote-21964486
Ref: Porting to Python 3 11<2>-Footnote-22964552
Ref: Porting to Python 3 11<2>-Footnote-23964618
Ref: Porting to Python 3 11<2>-Footnote-24964671
Node: Deprecated<3>964704
Ref: whatsnew/3 11 id7964846
Ref: 995964846
Ref: whatsnew/3 11 whatsnew311-c-api-deprecated964846
Ref: 925964846
Ref: Deprecated<3>-Footnote-1965815
Ref: Deprecated<3>-Footnote-2965857
Ref: Deprecated<3>-Footnote-3965912
Node: Pending Removal in Python 3 12<2>965977
Ref: whatsnew/3 11 id8966104
Ref: 997966104
Ref: whatsnew/3 11 whatsnew311-c-api-pending-removal966104
Ref: 934966104
Node: Removed<3>966854
Ref: whatsnew/3 11 id9966959
Ref: 999966959
Ref: whatsnew/3 11 whatsnew311-c-api-removed966959
Ref: 93a966959
Ref: whatsnew/3 11 whatsnew311-pep624969219
Ref: 7cb969219
Ref: Removed<3>-Footnote-1970159
Ref: Removed<3>-Footnote-2970224
Ref: Removed<3>-Footnote-3970289
Ref: Removed<3>-Footnote-4970354
Ref: Removed<3>-Footnote-5970419
Ref: Removed<3>-Footnote-6970484
Ref: Removed<3>-Footnote-7970549
Ref: Removed<3>-Footnote-8970614
Ref: Removed<3>-Footnote-9970679
Ref: Removed<3>-Footnote-10970744
Ref: Removed<3>-Footnote-11970787
Ref: Removed<3>-Footnote-12970847
Node: Notable changes in 3 11 4970913
Ref: whatsnew/3 11 notable-changes-in-3-11-4971061
Ref: 99f971061
Node: tarfile<2>971161
Ref: whatsnew/3 11 tarfile971233
Ref: 9a0971233
Ref: tarfile<2>-Footnote-1971837
Node: Notable changes in 3 11 5971879
Ref: whatsnew/3 11 notable-changes-in-3-11-5972002
Ref: 9a1972002
Node: OpenSSL972091
Ref: whatsnew/3 11 openssl972160
Ref: 9a2972160
Node: What’s New In Python 3 10972279
Ref: whatsnew/3 10 doc972431
Ref: 9a3972431
Ref: whatsnew/3 10 translation-repo972431
Ref: 9a4972431
Ref: whatsnew/3 10 what-s-new-in-python-3-10972431
Ref: 9a5972431
Node: Summary – Release highlights<3>973477
Ref: whatsnew/3 10 summary-release-highlights973598
Ref: 9a6973598
Ref: Summary – Release highlights<3>-Footnote-1974751
Ref: Summary – Release highlights<3>-Footnote-2974793
Ref: Summary – Release highlights<3>-Footnote-3974835
Ref: Summary – Release highlights<3>-Footnote-4974877
Ref: Summary – Release highlights<3>-Footnote-5974942
Ref: Summary – Release highlights<3>-Footnote-6974984
Ref: Summary – Release highlights<3>-Footnote-7975026
Ref: Summary – Release highlights<3>-Footnote-8975068
Ref: Summary – Release highlights<3>-Footnote-9975110
Ref: Summary – Release highlights<3>-Footnote-10975152
Ref: Summary – Release highlights<3>-Footnote-11975195
Ref: Summary – Release highlights<3>-Footnote-12975238
Ref: Summary – Release highlights<3>-Footnote-13975281
Ref: Summary – Release highlights<3>-Footnote-14975324
Ref: Summary – Release highlights<3>-Footnote-15975367
Node: New Features<5>975410
Ref: whatsnew/3 10 new-features975577
Ref: 9a7975577
Node: Parenthesized context managers975945
Ref: whatsnew/3 10 parenthesized-context-managers976057
Ref: 9a8976057
Ref: whatsnew/3 10 whatsnew310-pep563976057
Ref: 9a9976057
Ref: Parenthesized context managers-Footnote-1977301
Ref: Parenthesized context managers-Footnote-2977343
Ref: Parenthesized context managers-Footnote-3977408
Node: Better error messages977473
Ref: whatsnew/3 10 better-error-messages977652
Ref: 9aa977652
Node: SyntaxErrors977797
Ref: whatsnew/3 10 syntaxerrors977893
Ref: 9ab977893
Ref: SyntaxErrors-Footnote-1983230
Ref: SyntaxErrors-Footnote-2983295
Ref: SyntaxErrors-Footnote-3983360
Ref: SyntaxErrors-Footnote-4983425
Ref: SyntaxErrors-Footnote-5983490
Ref: SyntaxErrors-Footnote-6983555
Ref: SyntaxErrors-Footnote-7983620
Ref: SyntaxErrors-Footnote-8983685
Ref: SyntaxErrors-Footnote-9983750
Ref: SyntaxErrors-Footnote-10983815
Ref: SyntaxErrors-Footnote-11983881
Node: IndentationErrors983947
Ref: whatsnew/3 10 indentationerrors984067
Ref: 9ac984067
Node: AttributeErrors984484
Ref: whatsnew/3 10 attributeerrors984602
Ref: 9ae984602
Ref: AttributeErrors-Footnote-1985360
Node: NameErrors985425
Ref: whatsnew/3 10 nameerrors985517
Ref: 9af985517
Ref: NameErrors-Footnote-1986335
Node: PEP 626 Precise line numbers for debugging and other tools986400
Ref: whatsnew/3 10 pep-626-precise-line-numbers-for-debugging-and-other-tools986584
Ref: 9b0986584
Node: PEP 634 Structural Pattern Matching987279
Ref: whatsnew/3 10 pep-634-structural-pattern-matching987495
Ref: 9b2987495
Node: Syntax and operations988282
Ref: whatsnew/3 10 syntax-and-operations988404
Ref: 9b3988404
Node: Declarative approach989470
Ref: whatsnew/3 10 declarative-approach989634
Ref: 9b4989634
Node: Simple pattern match to a literal990803
Ref: whatsnew/3 10 simple-pattern-match-to-a-literal990982
Ref: 9b5990982
Node: Behavior without the wildcard992351
Ref: whatsnew/3 10 behavior-without-the-wildcard992450
Ref: 9b6992450
Node: Patterns with a literal and variable993032
Ref: whatsnew/3 10 patterns-with-a-literal-and-variable993211
Ref: 9b7993211
Node: Patterns and classes994179
Ref: whatsnew/3 10 patterns-and-classes994340
Ref: 9b8994340
Node: Patterns with positional parameters995279
Ref: whatsnew/3 10 patterns-with-positional-parameters995371
Ref: 9b9995371
Node: Nested patterns995956
Ref: whatsnew/3 10 nested-patterns996114
Ref: 9ba996114
Node: Complex patterns and the wildcard996753
Ref: whatsnew/3 10 complex-patterns-and-the-wildcard996896
Ref: 9bb996896
Node: Guard997470
Ref: whatsnew/3 10 guard997616
Ref: 9bc997616
Node: Other Key Features998058
Ref: whatsnew/3 10 other-key-features998162
Ref: 9bd998162
Ref: Other Key Features-Footnote-11000334
Ref: Other Key Features-Footnote-21000376
Ref: Other Key Features-Footnote-31000418
Node: Optional EncodingWarning and encoding="locale" option1000460
Ref: whatsnew/3 10 optional-encodingwarning-and-encoding-locale-option1000609
Ref: 9be1000609
Ref: whatsnew/3 10 whatsnew310-pep5971000609
Ref: 9bf1000609
Node: New Features Related to Type Hints<2>1001509
Ref: whatsnew/3 10 new-feat-related-type-hints1001668
Ref: 9c31001668
Ref: whatsnew/3 10 new-features-related-to-type-hints1001668
Ref: 9c41001668
Ref: New Features Related to Type Hints<2>-Footnote-11002169
Node: PEP 604 New Type Union Operator1002211
Ref: whatsnew/3 10 pep-604-new-type-union-operator1002366
Ref: 9c51002366
Ref: PEP 604 New Type Union Operator-Footnote-11003441
Ref: PEP 604 New Type Union Operator-Footnote-21003483
Ref: PEP 604 New Type Union Operator-Footnote-31003548
Node: PEP 612 Parameter Specification Variables1003613
Ref: whatsnew/3 10 pep-612-parameter-specification-variables1003794
Ref: 9c81003794
Ref: PEP 612 Parameter Specification Variables-Footnote-11005081
Ref: PEP 612 Parameter Specification Variables-Footnote-21005123
Ref: PEP 612 Parameter Specification Variables-Footnote-31005165
Ref: PEP 612 Parameter Specification Variables-Footnote-41005230
Node: PEP 613 TypeAlias1005295
Ref: whatsnew/3 10 pep-613-typealias1005477
Ref: 9cd1005477
Ref: PEP 613 TypeAlias-Footnote-11006305
Ref: PEP 613 TypeAlias-Footnote-21006347
Ref: PEP 613 TypeAlias-Footnote-31006389
Node: PEP 647 User-Defined Type Guards1006454
Ref: whatsnew/3 10 pep-647-user-defined-type-guards1006586
Ref: 9cf1006586
Ref: PEP 647 User-Defined Type Guards-Footnote-11007074
Ref: PEP 647 User-Defined Type Guards-Footnote-21007116
Node: Other Language Changes<3>1007181
Ref: whatsnew/3 10 other-language-changes1007339
Ref: 9d01007339
Ref: Other Language Changes<3>-Footnote-11012023
Ref: Other Language Changes<3>-Footnote-21012088
Ref: Other Language Changes<3>-Footnote-31012153
Ref: Other Language Changes<3>-Footnote-41012195
Ref: Other Language Changes<3>-Footnote-51012260
Ref: Other Language Changes<3>-Footnote-61012325
Ref: Other Language Changes<3>-Footnote-71012390
Ref: Other Language Changes<3>-Footnote-81012455
Ref: Other Language Changes<3>-Footnote-91012520
Ref: Other Language Changes<3>-Footnote-101012562
Ref: Other Language Changes<3>-Footnote-111012628
Ref: Other Language Changes<3>-Footnote-121012694
Ref: Other Language Changes<3>-Footnote-131012760
Ref: Other Language Changes<3>-Footnote-141012826
Ref: Other Language Changes<3>-Footnote-151012892
Ref: Other Language Changes<3>-Footnote-161012958
Node: New Modules<3>1013024
Ref: whatsnew/3 10 new-modules1013164
Ref: 9dd1013164
Node: Improved Modules<3>1013213
Ref: whatsnew/3 10 improved-modules1013344
Ref: 9de1013344
Node: asyncio<7>1014513
Ref: whatsnew/3 10 asyncio1014599
Ref: 9df1014599
Ref: asyncio<7>-Footnote-11014777
Node: argparse<4>1014842
Ref: whatsnew/3 10 argparse1014945
Ref: 9e11014945
Ref: argparse<4>-Footnote-11015231
Node: array<3>1015295
Ref: whatsnew/3 10 array1015411
Ref: 9e21015411
Ref: array<3>-Footnote-11015653
Node: asynchat asyncore smtpd1015718
Ref: whatsnew/3 10 asynchat-asyncore-smtpd1015832
Ref: 9e41015832
Node: base64<3>1016092
Ref: whatsnew/3 10 base641016204
Ref: 9e51016204
Node: bdb<2>1016371
Ref: whatsnew/3 10 bdb1016466
Ref: 9e81016466
Ref: bdb<2>-Footnote-11016635
Node: bisect1016700
Ref: whatsnew/3 10 bisect1016792
Ref: 9e91016792
Ref: bisect-Footnote-11017009
Node: codecs1017073
Ref: whatsnew/3 10 codecs1017174
Ref: 9ea1017174
Ref: codecs-Footnote-11017371
Node: collections abc1017436
Ref: whatsnew/3 10 collections-abc1017544
Ref: 9ec1017544
Ref: collections abc-Footnote-11018465
Node: contextlib<2>1018530
Ref: whatsnew/3 10 contextlib1018641
Ref: 9ef1018641
Ref: contextlib<2>-Footnote-11019163
Ref: contextlib<2>-Footnote-21019228
Node: curses<2>1019293
Ref: whatsnew/3 10 curses1019403
Ref: 9f31019403
Ref: curses<2>-Footnote-11020100
Ref: curses<2>-Footnote-21020165
Node: dataclasses<2>1020230
Ref: whatsnew/3 10 dataclasses1020339
Ref: 9f91020339
Node: __slots__1020430
Ref: whatsnew/3 10 slots1020518
Ref: 9fa1020518
Ref: __slots__-Footnote-11020720
Node: Keyword-only fields1020785
Ref: whatsnew/3 10 keyword-only-fields1020873
Ref: 9fb1020873
Ref: Keyword-only fields-Footnote-11022346
Node: distutils<2>1022411
Ref: whatsnew/3 10 distutils1022521
Ref: 9fc1022521
Ref: whatsnew/3 10 distutils-deprecated1022521
Ref: 9351022521
Ref: distutils<2>-Footnote-11023429
Ref: distutils<2>-Footnote-21023471
Node: doctest<2>1023536
Ref: whatsnew/3 10 doctest1023641
Ref: 9fd1023641
Ref: doctest<2>-Footnote-11023845
Node: encodings1023910
Ref: whatsnew/3 10 encodings1024010
Ref: 9fe1024010
Ref: encodings-Footnote-11024206
Node: enum<4>1024271
Ref: whatsnew/3 10 enum1024370
Ref: a001024370
Ref: enum<4>-Footnote-11024843
Ref: enum<4>-Footnote-21024908
Node: fileinput1024973
Ref: whatsnew/3 10 fileinput1025078
Ref: a011025078
Ref: fileinput-Footnote-11025511
Ref: fileinput-Footnote-21025576
Node: faulthandler<2>1025640
Ref: whatsnew/3 10 faulthandler1025743
Ref: a041025743
Ref: faulthandler<2>-Footnote-11025985
Node: gc<2>1026050
Ref: whatsnew/3 10 gc1026151
Ref: a051026151
Ref: gc<2>-Footnote-11026376
Node: glob<2>1026441
Ref: whatsnew/3 10 glob1026537
Ref: a091026537
Ref: glob<2>-Footnote-11026801
Node: hashlib<3>1026866
Ref: whatsnew/3 10 hashlib1026964
Ref: a0b1026964
Ref: hashlib<3>-Footnote-11027507
Ref: hashlib<3>-Footnote-21027549
Ref: hashlib<3>-Footnote-31027614
Ref: hashlib<3>-Footnote-41027679
Node: hmac<2>1027744
Ref: whatsnew/3 10 hmac1027854
Ref: a0c1027854
Ref: hmac<2>-Footnote-11028040
Node: IDLE and idlelib<2>1028105
Ref: whatsnew/3 10 idle-and-idlelib1028226
Ref: a0d1028226
Ref: IDLE and idlelib<2>-Footnote-11030316
Ref: IDLE and idlelib<2>-Footnote-21030381
Ref: IDLE and idlelib<2>-Footnote-31030446
Ref: IDLE and idlelib<2>-Footnote-41030511
Ref: IDLE and idlelib<2>-Footnote-51030576
Ref: IDLE and idlelib<2>-Footnote-61030641
Ref: IDLE and idlelib<2>-Footnote-71030706
Ref: IDLE and idlelib<2>-Footnote-81030771
Node: importlib metadata<2>1030826
Ref: whatsnew/3 10 importlib-metadata1030950
Ref: a121030950
Ref: importlib metadata<2>-Footnote-11031544
Node: inspect<4>1031617
Ref: whatsnew/3 10 inspect1031734
Ref: a151031734
Ref: inspect<4>-Footnote-11032937
Ref: inspect<4>-Footnote-21033002
Node: itertools<4>1033067
Ref: whatsnew/3 10 itertools1033175
Ref: a171033175
Ref: itertools<4>-Footnote-11033341
Node: linecache<2>1033406
Ref: whatsnew/3 10 linecache1033509
Ref: a191033509
Ref: linecache<2>-Footnote-11033717
Node: os<5>1033782
Ref: whatsnew/3 10 os1033883
Ref: a1a1033883
Ref: os<5>-Footnote-11034622
Ref: os<5>-Footnote-21034687
Ref: os<5>-Footnote-31034752
Ref: os<5>-Footnote-41034817
Node: os path<4>1034882
Ref: whatsnew/3 10 os-path1034981
Ref: a211034981
Ref: os path<4>-Footnote-11035292
Node: pathlib<8>1035357
Ref: whatsnew/3 10 pathlib1035462
Ref: a221035462
Ref: pathlib<8>-Footnote-11036171
Ref: pathlib<8>-Footnote-21036236
Ref: pathlib<8>-Footnote-31036301
Ref: pathlib<8>-Footnote-41036366
Node: platform<3>1036431
Ref: whatsnew/3 10 platform1036532
Ref: a281036532
Ref: platform<3>-Footnote-11036801
Ref: platform<3>-Footnote-21036874
Node: pprint1036939
Ref: whatsnew/3 10 pprint1037040
Ref: a2a1037040
Ref: pprint-Footnote-11037374
Ref: pprint-Footnote-21037439
Node: py_compile1037504
Ref: whatsnew/3 10 py-compile1037600
Ref: a2c1037600
Ref: py_compile-Footnote-11037808
Node: pyclbr1037873
Ref: whatsnew/3 10 pyclbr1037969
Ref: a2d1037969
Ref: pyclbr-Footnote-11038313
Node: shelve1038378
Ref: whatsnew/3 10 shelve1038477
Ref: a301038477
Ref: shelve-Footnote-11038750
Node: statistics<2>1038815
Ref: whatsnew/3 10 statistics1038915
Ref: a321038915
Ref: statistics<2>-Footnote-11039170
Node: site<2>1039235
Ref: whatsnew/3 10 site1039338
Ref: a351039338
Ref: site<2>-Footnote-11039536
Node: socket<3>1039601
Ref: whatsnew/3 10 socket1039697
Ref: a361039697
Ref: socket<3>-Footnote-11040143
Ref: socket<3>-Footnote-21040208
Ref: socket<3>-Footnote-31040273
Node: ssl<4>1040338
Ref: whatsnew/3 10 ssl1040437
Ref: a391040437
Ref: ssl<4>-Footnote-11042278
Ref: ssl<4>-Footnote-21042320
Ref: ssl<4>-Footnote-31042385
Ref: ssl<4>-Footnote-41042450
Ref: ssl<4>-Footnote-51042515
Ref: ssl<4>-Footnote-61042580
Ref: ssl<4>-Footnote-71042645
Ref: ssl<4>-Footnote-81042710
Ref: ssl<4>-Footnote-91042775
Ref: ssl<4>-Footnote-101042840
Ref: ssl<4>-Footnote-111042906
Ref: ssl<4>-Footnote-121042972
Ref: ssl<4>-Footnote-131043038
Ref: ssl<4>-Footnote-141043104
Ref: ssl<4>-Footnote-151043170
Node: sqlite3<6>1043236
Ref: whatsnew/3 10 sqlite31043332
Ref: a401043332
Ref: sqlite3<6>-Footnote-11043568
Node: sys<5>1043633
Ref: whatsnew/3 10 sys1043730
Ref: a421043730
Ref: sys<5>-Footnote-11044115
Ref: sys<5>-Footnote-21044180
Node: _thread1044245
Ref: whatsnew/3 10 thread1044344
Ref: a451044344
Ref: _thread-Footnote-11044600
Node: threading<4>1044665
Ref: whatsnew/3 10 threading1044770
Ref: a471044770
Ref: threading<4>-Footnote-11045312
Ref: threading<4>-Footnote-21045377
Node: traceback<3>1045442
Ref: whatsnew/3 10 traceback1045548
Ref: a4e1045548
Ref: traceback<3>-Footnote-11045876
Node: types<4>1045941
Ref: whatsnew/3 10 types1046044
Ref: a521046044
Ref: types<4>-Footnote-11046353
Node: typing<6>1046418
Ref: whatsnew/3 10 typing1046520
Ref: a561046520
Ref: typing<6>-Footnote-11048740
Ref: typing<6>-Footnote-21048782
Ref: typing<6>-Footnote-31048847
Ref: typing<6>-Footnote-41048912
Ref: typing<6>-Footnote-51048977
Node: unittest<6>1049042
Ref: whatsnew/3 10 unittest1049148
Ref: a591049148
Ref: unittest<6>-Footnote-11049364
Node: urllib parse1049429
Ref: whatsnew/3 10 urllib-parse1049532
Ref: a5c1049532
Ref: urllib parse-Footnote-11050681
Ref: urllib parse-Footnote-21050746
Ref: urllib parse-Footnote-31050805
Node: xml<2>1050860
Ref: whatsnew/3 10 xml1050964
Ref: a5d1050964
Ref: xml<2>-Footnote-11051180
Node: zipimport<3>1051245
Ref: whatsnew/3 10 zipimport1051328
Ref: a5f1051328
Ref: zipimport<3>-Footnote-11051708
Ref: zipimport<3>-Footnote-21051750
Ref: zipimport<3>-Footnote-31051815
Node: Optimizations<4>1051880
Ref: whatsnew/3 10 optimizations1052010
Ref: a631052010
Ref: Optimizations<4>-Footnote-11055498
Ref: Optimizations<4>-Footnote-21055563
Ref: Optimizations<4>-Footnote-31055628
Ref: Optimizations<4>-Footnote-41055693
Ref: Optimizations<4>-Footnote-51055758
Ref: Optimizations<4>-Footnote-61055823
Ref: Optimizations<4>-Footnote-71055944
Ref: Optimizations<4>-Footnote-81056009
Ref: Optimizations<4>-Footnote-91056074
Ref: Optimizations<4>-Footnote-101056139
Ref: Optimizations<4>-Footnote-111056205
Ref: Optimizations<4>-Footnote-121056271
Ref: Optimizations<4>-Footnote-131056314
Ref: Optimizations<4>-Footnote-141056380
Ref: Optimizations<4>-Footnote-151056446
Ref: Optimizations<4>-Footnote-161056512
Ref: Optimizations<4>-Footnote-171056578
Ref: Optimizations<4>-Footnote-181056644
Node: Deprecated<4>1056710
Ref: whatsnew/3 10 deprecated1056831
Ref: a691056831
Ref: whatsnew/3 10 whatsnew310-deprecated1056831
Ref: a3e1056831
Ref: Deprecated<4>-Footnote-11066246
Ref: Deprecated<4>-Footnote-21066311
Ref: Deprecated<4>-Footnote-31066376
Ref: Deprecated<4>-Footnote-41066441
Ref: Deprecated<4>-Footnote-51066506
Ref: Deprecated<4>-Footnote-61066571
Ref: Deprecated<4>-Footnote-71066636
Ref: Deprecated<4>-Footnote-81066701
Ref: Deprecated<4>-Footnote-91066766
Ref: Deprecated<4>-Footnote-101066831
Ref: Deprecated<4>-Footnote-111066897
Ref: Deprecated<4>-Footnote-121066963
Ref: Deprecated<4>-Footnote-131067029
Ref: Deprecated<4>-Footnote-141067095
Ref: Deprecated<4>-Footnote-151067154
Ref: Deprecated<4>-Footnote-161067220
Ref: Deprecated<4>-Footnote-171067276
Ref: Deprecated<4>-Footnote-181067342
Ref: Deprecated<4>-Footnote-191067408
Ref: Deprecated<4>-Footnote-201067474
Node: Removed<4>1067540
Ref: whatsnew/3 10 removed1067667
Ref: a771067667
Ref: whatsnew/3 10 whatsnew310-removed1067667
Ref: a781067667
Ref: Removed<4>-Footnote-11070907
Ref: Removed<4>-Footnote-21070972
Ref: Removed<4>-Footnote-31071037
Ref: Removed<4>-Footnote-41071102
Ref: Removed<4>-Footnote-51071167
Ref: Removed<4>-Footnote-61071232
Ref: Removed<4>-Footnote-71071297
Node: Porting to Python 3 101071362
Ref: whatsnew/3 10 porting-to-python-3-101071503
Ref: a7d1071503
Node: Changes in the Python syntax1071822
Ref: whatsnew/3 10 changes-in-the-python-syntax1071946
Ref: a7e1071946
Ref: Changes in the Python syntax-Footnote-11072541
Node: Changes in the Python API<3>1072606
Ref: whatsnew/3 10 changes-in-the-python-api1072762
Ref: a7f1072762
Ref: whatsnew/3 10 changes-python-api1072762
Ref: a7c1072762
Ref: Changes in the Python API<3>-Footnote-11075691
Ref: Changes in the Python API<3>-Footnote-21075756
Ref: Changes in the Python API<3>-Footnote-31075821
Ref: Changes in the Python API<3>-Footnote-41075886
Ref: Changes in the Python API<3>-Footnote-51075951
Ref: Changes in the Python API<3>-Footnote-61076016
Node: Changes in the C API<3>1076081
Ref: whatsnew/3 10 changes-in-the-c-api1076200
Ref: a861076200
Node: CPython bytecode changes<3>1078672
Ref: whatsnew/3 10 cpython-bytecode-changes1078819
Ref: a8c1078819
Ref: CPython bytecode changes<3>-Footnote-11079118
Node: Build Changes<3>1079183
Ref: whatsnew/3 10 build-changes1079324
Ref: a8d1079324
Ref: Build Changes<3>-Footnote-11081788
Ref: Build Changes<3>-Footnote-21081830
Ref: Build Changes<3>-Footnote-31081895
Ref: Build Changes<3>-Footnote-41081960
Ref: Build Changes<3>-Footnote-51082025
Ref: Build Changes<3>-Footnote-61082090
Ref: Build Changes<3>-Footnote-71082155
Ref: Build Changes<3>-Footnote-81082220
Ref: Build Changes<3>-Footnote-91082285
Ref: Build Changes<3>-Footnote-101082350
Ref: Build Changes<3>-Footnote-111082416
Node: C API Changes<3>1082482
Ref: whatsnew/3 10 c-api-changes1082630
Ref: a921082630
Node: PEP 652 Maintaining the Stable ABI1082896
Ref: whatsnew/3 10 pep-652-maintaining-the-stable-abi1083007
Ref: a931083007
Ref: PEP 652 Maintaining the Stable ABI-Footnote-11083440
Ref: PEP 652 Maintaining the Stable ABI-Footnote-21083482
Node: New Features<6>1083547
Ref: whatsnew/3 10 id11083692
Ref: a941083692
Ref: New Features<6>-Footnote-11088319
Ref: New Features<6>-Footnote-21088384
Ref: New Features<6>-Footnote-31088449
Ref: New Features<6>-Footnote-41088514
Ref: New Features<6>-Footnote-51088579
Ref: New Features<6>-Footnote-61088644
Ref: New Features<6>-Footnote-71088709
Ref: New Features<6>-Footnote-81088776
Ref: New Features<6>-Footnote-91088841
Ref: New Features<6>-Footnote-101088906
Ref: New Features<6>-Footnote-111088972
Ref: New Features<6>-Footnote-121089038
Ref: New Features<6>-Footnote-131089104
Ref: New Features<6>-Footnote-141089170
Ref: New Features<6>-Footnote-151089236
Ref: New Features<6>-Footnote-161089302
Ref: New Features<6>-Footnote-171089368
Ref: New Features<6>-Footnote-181089434
Node: Porting to Python 3 10<2>1089500
Ref: whatsnew/3 10 id21089624
Ref: aa91089624
Ref: Porting to Python 3 10<2>-Footnote-11093310
Ref: Porting to Python 3 10<2>-Footnote-21093352
Ref: Porting to Python 3 10<2>-Footnote-31093417
Ref: Porting to Python 3 10<2>-Footnote-41093482
Ref: Porting to Python 3 10<2>-Footnote-51093547
Ref: Porting to Python 3 10<2>-Footnote-61093612
Ref: Porting to Python 3 10<2>-Footnote-71093677
Ref: Porting to Python 3 10<2>-Footnote-81093742
Ref: Porting to Python 3 10<2>-Footnote-91093807
Ref: Porting to Python 3 10<2>-Footnote-101093872
Ref: Porting to Python 3 10<2>-Footnote-111093938
Node: Deprecated<5>1094004
Ref: whatsnew/3 10 id31094123
Ref: aaf1094123
Ref: Deprecated<5>-Footnote-11094422
Node: Removed<5>1094487
Ref: whatsnew/3 10 id41094572
Ref: ab11094572
Ref: Removed<5>-Footnote-11099576
Ref: Removed<5>-Footnote-21099641
Ref: Removed<5>-Footnote-31099683
Ref: Removed<5>-Footnote-41099748
Ref: Removed<5>-Footnote-51099813
Ref: Removed<5>-Footnote-61099878
Ref: Removed<5>-Footnote-71099943
Ref: Removed<5>-Footnote-81100008
Ref: Removed<5>-Footnote-91100073
Ref: Removed<5>-Footnote-101100115
Ref: Removed<5>-Footnote-111100181
Ref: Removed<5>-Footnote-121100247
Ref: Removed<5>-Footnote-131100313
Ref: Removed<5>-Footnote-141100379
Ref: Removed<5>-Footnote-151100445
Ref: Removed<5>-Footnote-161100511
Node: Notable security feature in 3 10 71100577
Ref: whatsnew/3 10 notable-security-feature-in-3-10-71100743
Ref: abe1100743
Ref: Notable security feature in 3 10 7-Footnote-11101473
Node: Notable security feature in 3 10 81101529
Ref: whatsnew/3 10 notable-security-feature-in-3-10-81101705
Ref: abf1101705
Ref: Notable security feature in 3 10 8-Footnote-11102127
Node: Notable changes in 3 10 121102182
Ref: whatsnew/3 10 notable-changes-in-3-10-121102315
Ref: ac01102315
Node: tarfile<3>1102417
Ref: whatsnew/3 10 tarfile1102490
Ref: ac11102490
Ref: tarfile<3>-Footnote-11103094
Node: What’s New In Python 3 91103136
Ref: whatsnew/3 9 doc1103287
Ref: ac21103287
Ref: whatsnew/3 9 translation-repo1103287
Ref: ac31103287
Ref: whatsnew/3 9 what-s-new-in-python-3-91103287
Ref: ac41103287
Ref: What’s New In Python 3 9-Footnote-11104539
Node: Summary – Release highlights<4>1104581
Ref: whatsnew/3 9 summary-release-highlights1104738
Ref: ac51104738
Ref: Summary – Release highlights<4>-Footnote-11106692
Ref: Summary – Release highlights<4>-Footnote-21106734
Ref: Summary – Release highlights<4>-Footnote-31106776
Ref: Summary – Release highlights<4>-Footnote-41106818
Ref: Summary – Release highlights<4>-Footnote-51106860
Ref: Summary – Release highlights<4>-Footnote-61106902
Ref: Summary – Release highlights<4>-Footnote-71106944
Ref: Summary – Release highlights<4>-Footnote-81106986
Ref: Summary – Release highlights<4>-Footnote-91107028
Ref: Summary – Release highlights<4>-Footnote-101107070
Node: You should check for DeprecationWarning in your code1107113
Ref: whatsnew/3 9 you-should-check-for-deprecationwarning-in-your-code1107294
Ref: ac61107294
Node: New Features<7>1108984
Ref: whatsnew/3 9 new-features1109157
Ref: acb1109157
Node: Dictionary Merge & Update Operators1109366
Ref: whatsnew/3 9 dictionary-merge-update-operators1109512
Ref: acc1109512
Ref: Dictionary Merge & Update Operators-Footnote-11110267
Ref: Dictionary Merge & Update Operators-Footnote-21110309
Node: New String Methods to Remove Prefixes and Suffixes1110374
Ref: whatsnew/3 9 new-string-methods-to-remove-prefixes-and-suffixes1110574
Ref: acd1110574
Ref: New String Methods to Remove Prefixes and Suffixes-Footnote-11111085
Ref: New String Methods to Remove Prefixes and Suffixes-Footnote-21111127
Node: Type Hinting Generics in Standard Collections1111192
Ref: whatsnew/3 9 type-hinting-generics-in-standard-collections1111367
Ref: ad01111367
Ref: Type Hinting Generics in Standard Collections-Footnote-11112069
Ref: Type Hinting Generics in Standard Collections-Footnote-21112111
Node: New Parser1112176
Ref: whatsnew/3 9 new-parser1112292
Ref: ad11112292
Ref: New Parser-Footnote-11113227
Ref: New Parser-Footnote-21113292
Ref: New Parser-Footnote-31113340
Ref: New Parser-Footnote-41113382
Node: Other Language Changes<4>1113447
Ref: whatsnew/3 9 other-language-changes1113582
Ref: ad21113582
Ref: Other Language Changes<4>-Footnote-11116688
Ref: Other Language Changes<4>-Footnote-21116753
Ref: Other Language Changes<4>-Footnote-31116818
Ref: Other Language Changes<4>-Footnote-41116883
Ref: Other Language Changes<4>-Footnote-51116948
Ref: Other Language Changes<4>-Footnote-61116990
Ref: Other Language Changes<4>-Footnote-71117055
Ref: Other Language Changes<4>-Footnote-81117120
Ref: Other Language Changes<4>-Footnote-91117185
Ref: Other Language Changes<4>-Footnote-101117250
Ref: Other Language Changes<4>-Footnote-111117316
Node: New Modules<4>1117382
Ref: whatsnew/3 9 new-modules1117521
Ref: adc1117521
Node: zoneinfo1117606
Ref: whatsnew/3 9 zoneinfo1117685
Ref: add1117685
Ref: zoneinfo-Footnote-11118797
Ref: zoneinfo-Footnote-21118838
Node: graphlib<2>1118880
Ref: whatsnew/3 9 graphlib1118959
Ref: adf1118959
Ref: graphlib<2>-Footnote-11119283
Node: Improved Modules<4>1119348
Ref: whatsnew/3 9 improved-modules1119478
Ref: ae11119478
Node: ast<4>1120321
Ref: whatsnew/3 9 ast1120402
Ref: ae21120402
Ref: ast<4>-Footnote-11121070
Ref: ast<4>-Footnote-21121135
Ref: ast<4>-Footnote-31121200
Node: asyncio<8>1121265
Ref: whatsnew/3 9 asyncio1121368
Ref: ae51121368
Ref: asyncio<8>-Footnote-11123091
Ref: asyncio<8>-Footnote-21123156
Ref: asyncio<8>-Footnote-31123221
Ref: asyncio<8>-Footnote-41123286
Ref: asyncio<8>-Footnote-51123351
Ref: asyncio<8>-Footnote-61123416
Node: compileall<2>1123481
Ref: whatsnew/3 9 compileall1123599
Ref: aea1123599
Ref: compileall<2>-Footnote-11124189
Ref: compileall<2>-Footnote-21124254
Node: concurrent futures<3>1124319
Ref: whatsnew/3 9 concurrent-futures1124436
Ref: aeb1124436
Ref: concurrent futures<3>-Footnote-11125315
Ref: concurrent futures<3>-Footnote-21125380
Ref: concurrent futures<3>-Footnote-31125445
Node: curses<3>1125510
Ref: whatsnew/3 9 curses1125625
Ref: aed1125625
Ref: curses<3>-Footnote-11125899
Node: datetime<3>1125964
Ref: whatsnew/3 9 datetime1126070
Ref: af21126070
Ref: datetime<3>-Footnote-11126388
Node: distutils<3>1126453
Ref: whatsnew/3 9 distutils1126558
Ref: af51126558
Ref: distutils<3>-Footnote-11126809
Node: fcntl<2>1126874
Ref: whatsnew/3 9 fcntl1126977
Ref: af61126977
Ref: fcntl<2>-Footnote-11127184
Node: ftplib<2>1127249
Ref: whatsnew/3 9 ftplib1127345
Ref: af71127345
Ref: ftplib<2>-Footnote-11127635
Node: gc<3>1127700
Ref: whatsnew/3 9 gc1127798
Ref: afa1127798
Ref: gc<3>-Footnote-11128336
Ref: gc<3>-Footnote-21128401
Node: hashlib<4>1128466
Ref: whatsnew/3 9 hashlib1128562
Ref: afc1128562
Ref: hashlib<4>-Footnote-11129071
Ref: hashlib<4>-Footnote-21129136
Node: http<2>1129201
Ref: whatsnew/3 9 http1129311
Ref: afd1129311
Ref: http<2>-Footnote-11129583
Ref: http<2>-Footnote-21129648
Node: IDLE and idlelib<3>1129713
Ref: whatsnew/3 9 idle-and-idlelib1129823
Ref: aff1129823
Ref: IDLE and idlelib<3>-Footnote-11131035
Ref: IDLE and idlelib<3>-Footnote-21131099
Ref: IDLE and idlelib<3>-Footnote-31131164
Ref: IDLE and idlelib<3>-Footnote-41131229
Ref: IDLE and idlelib<3>-Footnote-51131294
Ref: IDLE and idlelib<3>-Footnote-61131359
Ref: IDLE and idlelib<3>-Footnote-71131424
Node: imaplib<2>1131489
Ref: whatsnew/3 9 imaplib1131604
Ref: b001131604
Ref: imaplib<2>-Footnote-11132440
Ref: imaplib<2>-Footnote-21132505
Node: importlib<3>1132570
Ref: whatsnew/3 9 importlib1132676
Ref: b071132676
Ref: importlib<3>-Footnote-11133468
Ref: importlib<3>-Footnote-21133533
Ref: importlib<3>-Footnote-31133598
Node: inspect<5>1133663
Ref: whatsnew/3 9 inspect1133771
Ref: b091133771
Ref: inspect<5>-Footnote-11134003
Ref: inspect<5>-Footnote-21134068
Node: ipaddress<2>1134133
Ref: whatsnew/3 9 ipaddress1134236
Ref: b0b1134236
Ref: ipaddress<2>-Footnote-11134801
Ref: ipaddress<2>-Footnote-21134866
Node: math<4>1134931
Ref: whatsnew/3 9 math1135042
Ref: b0d1135042
Ref: math<4>-Footnote-11135758
Ref: math<4>-Footnote-21135823
Ref: math<4>-Footnote-31135888
Ref: math<4>-Footnote-41135953
Ref: math<4>-Footnote-51136018
Node: multiprocessing<3>1136083
Ref: whatsnew/3 9 multiprocessing1136189
Ref: b111136189
Ref: multiprocessing<3>-Footnote-11136445
Node: nntplib1136510
Ref: whatsnew/3 9 nntplib1136614
Ref: b141136614
Ref: nntplib-Footnote-11136898
Node: os<6>1136963
Ref: whatsnew/3 9 os1137059
Ref: b151137059
Ref: os<6>-Footnote-11137815
Ref: os<6>-Footnote-21137880
Ref: os<6>-Footnote-31137945
Ref: os<6>-Footnote-41138010
Ref: os<6>-Footnote-51138075
Ref: os<6>-Footnote-61138140
Node: pathlib<9>1138205
Ref: whatsnew/3 9 pathlib1138300
Ref: b1a1138300
Ref: pathlib<9>-Footnote-11138514
Node: pdb<5>1138579
Ref: whatsnew/3 9 pdb1138675
Ref: b1d1138675
Ref: pdb<5>-Footnote-11138863
Node: poplib1138928
Ref: whatsnew/3 9 poplib1139023
Ref: b1e1139023
Ref: poplib-Footnote-11139317
Node: pprint<2>1139382
Ref: whatsnew/3 9 pprint1139479
Ref: b211139479
Ref: pprint<2>-Footnote-11139675
Node: pydoc<2>1139740
Ref: whatsnew/3 9 pydoc1139840
Ref: b221139840
Ref: pydoc<2>-Footnote-11140107
Node: random<3>1140172
Ref: whatsnew/3 9 random1140269
Ref: b241140269
Ref: random<3>-Footnote-11140470
Node: signal1140535
Ref: whatsnew/3 9 signal1140631
Ref: b261140631
Ref: signal-Footnote-11140861
Node: smtplib1140926
Ref: whatsnew/3 9 smtplib1141022
Ref: b281141022
Ref: smtplib-Footnote-11141434
Ref: smtplib-Footnote-21141499
Node: socket<4>1141564
Ref: whatsnew/3 9 socket1141661
Ref: b2c1141661
Ref: socket<4>-Footnote-11142247
Ref: socket<4>-Footnote-21142312
Ref: socket<4>-Footnote-31142377
Node: time<3>1142442
Ref: whatsnew/3 9 time1142538
Ref: b311142538
Ref: time<3>-Footnote-11142868
Node: sys<6>1142933
Ref: whatsnew/3 9 sys1143031
Ref: b331143031
Ref: sys<6>-Footnote-11143696
Ref: sys<6>-Footnote-21143763
Node: tracemalloc1143828
Ref: whatsnew/3 9 tracemalloc1143928
Ref: b361143928
Ref: tracemalloc-Footnote-11144212
Node: typing<7>1144277
Ref: whatsnew/3 9 typing1144385
Ref: b381144385
Ref: typing<7>-Footnote-11144741
Node: unicodedata<5>1144783
Ref: whatsnew/3 9 unicodedata1144887
Ref: b3a1144887
Ref: unicodedata<5>-Footnote-11145040
Node: venv<3>1145105
Ref: whatsnew/3 9 venv1145206
Ref: b3b1145206
Ref: venv<3>-Footnote-11145668
Node: xml<3>1145733
Ref: whatsnew/3 9 xml1145811
Ref: b3c1145811
Ref: xml<3>-Footnote-11146171
Node: Optimizations<5>1146236
Ref: whatsnew/3 9 optimizations1146365
Ref: b3d1146365
Ref: Optimizations<5>-Footnote-11152130
Ref: Optimizations<5>-Footnote-21152195
Ref: Optimizations<5>-Footnote-31152260
Ref: Optimizations<5>-Footnote-41152325
Ref: Optimizations<5>-Footnote-51152390
Ref: Optimizations<5>-Footnote-61152432
Ref: Optimizations<5>-Footnote-71152497
Ref: Optimizations<5>-Footnote-81152561
Ref: Optimizations<5>-Footnote-91152626
Ref: Optimizations<5>-Footnote-101152691
Ref: Optimizations<5>-Footnote-111152757
Ref: Optimizations<5>-Footnote-121152886
Node: Deprecated<6>1152935
Ref: whatsnew/3 9 deprecated1153055
Ref: b421153055
Ref: Deprecated<6>-Footnote-11158087
Ref: Deprecated<6>-Footnote-21158152
Ref: Deprecated<6>-Footnote-31158217
Ref: Deprecated<6>-Footnote-41158282
Ref: Deprecated<6>-Footnote-51158347
Ref: Deprecated<6>-Footnote-61158412
Ref: Deprecated<6>-Footnote-71158477
Ref: Deprecated<6>-Footnote-81158542
Ref: Deprecated<6>-Footnote-91158607
Ref: Deprecated<6>-Footnote-101158672
Ref: Deprecated<6>-Footnote-111158738
Ref: Deprecated<6>-Footnote-121158804
Ref: Deprecated<6>-Footnote-131158870
Ref: Deprecated<6>-Footnote-141158936
Ref: Deprecated<6>-Footnote-151159002
Ref: Deprecated<6>-Footnote-161159045
Ref: Deprecated<6>-Footnote-171159085
Ref: Deprecated<6>-Footnote-181159124
Ref: Deprecated<6>-Footnote-191159190
Node: Removed<6>1159256
Ref: whatsnew/3 9 removed1159381
Ref: b441159381
Ref: whatsnew/3 9 removed-in-python-391159381
Ref: aca1159381
Ref: Removed<6>-Footnote-11165529
Ref: Removed<6>-Footnote-21165594
Ref: Removed<6>-Footnote-31165659
Ref: Removed<6>-Footnote-41165724
Ref: Removed<6>-Footnote-51165789
Ref: Removed<6>-Footnote-61165854
Ref: Removed<6>-Footnote-71165919
Ref: Removed<6>-Footnote-81165984
Ref: Removed<6>-Footnote-91166049
Ref: Removed<6>-Footnote-101166114
Ref: Removed<6>-Footnote-111166180
Ref: Removed<6>-Footnote-121166223
Ref: Removed<6>-Footnote-131166289
Ref: Removed<6>-Footnote-141166355
Ref: Removed<6>-Footnote-151166421
Ref: Removed<6>-Footnote-161166487
Ref: Removed<6>-Footnote-171166553
Ref: Removed<6>-Footnote-181166619
Ref: Removed<6>-Footnote-191166685
Ref: Removed<6>-Footnote-201166751
Ref: Removed<6>-Footnote-211166817
Ref: Removed<6>-Footnote-221166883
Node: Porting to Python 3 91166949
Ref: whatsnew/3 9 porting-to-python-3-91167077
Ref: b531167077
Node: Changes in the Python API<4>1167418
Ref: whatsnew/3 9 changes-in-the-python-api1167536
Ref: b541167536
Ref: Changes in the Python API<4>-Footnote-11171732
Ref: Changes in the Python API<4>-Footnote-21171797
Ref: Changes in the Python API<4>-Footnote-31171862
Ref: Changes in the Python API<4>-Footnote-41171927
Ref: Changes in the Python API<4>-Footnote-51171986
Ref: Changes in the Python API<4>-Footnote-61172051
Ref: Changes in the Python API<4>-Footnote-71172116
Ref: Changes in the Python API<4>-Footnote-81172181
Ref: Changes in the Python API<4>-Footnote-91172246
Ref: Changes in the Python API<4>-Footnote-101172311
Ref: Changes in the Python API<4>-Footnote-111172377
Node: Changes in the C API<4>1172443
Ref: whatsnew/3 9 changes-in-the-c-api1172597
Ref: b5f1172597
Ref: Changes in the C API<4>-Footnote-11174732
Ref: Changes in the C API<4>-Footnote-21174797
Ref: Changes in the C API<4>-Footnote-31174862
Node: CPython bytecode changes<4>1174927
Ref: whatsnew/3 9 cpython-bytecode-changes1175044
Ref: b611175044
Ref: CPython bytecode changes<4>-Footnote-11175856
Ref: CPython bytecode changes<4>-Footnote-21175921
Node: Build Changes<4>1175986
Ref: whatsnew/3 9 build-changes1176120
Ref: b641176120
Ref: Build Changes<4>-Footnote-11178536
Ref: Build Changes<4>-Footnote-21178603
Ref: Build Changes<4>-Footnote-31178668
Ref: Build Changes<4>-Footnote-41178733
Ref: Build Changes<4>-Footnote-51178798
Ref: Build Changes<4>-Footnote-61178863
Ref: Build Changes<4>-Footnote-71178928
Ref: Build Changes<4>-Footnote-81178993
Node: C API Changes<4>1179058
Ref: whatsnew/3 9 c-api-changes1179202
Ref: b661179202
Node: New Features<8>1179362
Ref: whatsnew/3 9 id11179463
Ref: b671179463
Ref: New Features<8>-Footnote-11182484
Ref: New Features<8>-Footnote-21182526
Ref: New Features<8>-Footnote-31182591
Ref: New Features<8>-Footnote-41182656
Ref: New Features<8>-Footnote-51182721
Ref: New Features<8>-Footnote-61182786
Ref: New Features<8>-Footnote-71182851
Ref: New Features<8>-Footnote-81182916
Ref: New Features<8>-Footnote-91182981
Ref: New Features<8>-Footnote-101183046
Ref: New Features<8>-Footnote-111183112
Ref: New Features<8>-Footnote-121183178
Node: Porting to Python 3 9<2>1183244
Ref: whatsnew/3 9 id21183364
Ref: b721183364
Ref: Porting to Python 3 9<2>-Footnote-11187187
Ref: Porting to Python 3 9<2>-Footnote-21187229
Ref: Porting to Python 3 9<2>-Footnote-31187294
Ref: Porting to Python 3 9<2>-Footnote-41187359
Ref: Porting to Python 3 9<2>-Footnote-51187423
Ref: Porting to Python 3 9<2>-Footnote-61187488
Ref: Porting to Python 3 9<2>-Footnote-71187553
Ref: Porting to Python 3 9<2>-Footnote-81187595
Ref: Porting to Python 3 9<2>-Footnote-91187660
Ref: Porting to Python 3 9<2>-Footnote-101187725
Ref: Porting to Python 3 9<2>-Footnote-111187791
Node: Removed<7>1187857
Ref: whatsnew/3 9 id31187953
Ref: b851187953
Ref: Removed<7>-Footnote-11191894
Ref: Removed<7>-Footnote-21191959
Ref: Removed<7>-Footnote-31192024
Ref: Removed<7>-Footnote-41192089
Ref: Removed<7>-Footnote-51192154
Ref: Removed<7>-Footnote-61192219
Ref: Removed<7>-Footnote-71192284
Ref: Removed<7>-Footnote-81192349
Ref: Removed<7>-Footnote-91192414
Ref: Removed<7>-Footnote-101192479
Ref: Removed<7>-Footnote-111192545
Ref: Removed<7>-Footnote-121192588
Ref: Removed<7>-Footnote-131192654
Node: Notable changes in Python 3 9 11192720
Ref: whatsnew/3 9 notable-changes-in-python-3-9-11192879
Ref: b881192879
Node: typing<8>1193093
Ref: whatsnew/3 9 id41193227
Ref: b891193227
Ref: typing<8>-Footnote-11194419
Ref: typing<8>-Footnote-21194461
Node: macOS 11 0 Big Sur and Apple Silicon Mac support1194526
Ref: whatsnew/3 9 macos-11-0-big-sur-and-apple-silicon-mac-support1194660
Ref: b8a1194660
Ref: macOS 11 0 Big Sur and Apple Silicon Mac support-Footnote-11195468
Node: Notable changes in Python 3 9 21195533
Ref: whatsnew/3 9 notable-changes-in-python-3-9-21195707
Ref: b8b1195707
Node: collections abc<2>1195868
Ref: whatsnew/3 9 collections-abc1195978
Ref: b8c1195978
Ref: collections abc<2>-Footnote-11196957
Node: urllib parse<2>1197022
Ref: whatsnew/3 9 urllib-parse1197132
Ref: b8d1197132
Ref: urllib parse<2>-Footnote-11197816
Node: Notable changes in Python 3 9 31197881
Ref: whatsnew/3 9 notable-changes-in-python-3-9-31198055
Ref: b8e1198055
Ref: Notable changes in Python 3 9 3-Footnote-11198526
Node: Notable changes in Python 3 9 51198581
Ref: whatsnew/3 9 notable-changes-in-python-3-9-51198758
Ref: b8f1198758
Node: urllib parse<3>1198880
Ref: whatsnew/3 9 id51198963
Ref: b901198963
Ref: urllib parse<3>-Footnote-11199492
Ref: urllib parse<3>-Footnote-21199551
Node: Notable security feature in 3 9 141199606
Ref: whatsnew/3 9 notable-security-feature-in-3-9-141199777
Ref: b911199777
Ref: Notable security feature in 3 9 14-Footnote-11200507
Node: Notable changes in 3 9 171200563
Ref: whatsnew/3 9 notable-changes-in-3-9-171200694
Ref: b921200694
Node: tarfile<4>1200794
Ref: whatsnew/3 9 tarfile1200866
Ref: b931200866
Ref: tarfile<4>-Footnote-11201470
Node: What’s New In Python 3 81201512
Ref: whatsnew/3 8 doc1201662
Ref: b941201662
Ref: whatsnew/3 8 translation-repo1201662
Ref: b951201662
Ref: whatsnew/3 8 what-s-new-in-python-3-81201662
Ref: b961201662
Node: Summary – Release highlights<5>1203006
Ref: whatsnew/3 8 summary-release-highlights1203126
Ref: b971203126
Node: New Features<9>1203199
Ref: whatsnew/3 8 new-features1203353
Ref: b981203353
Node: Assignment expressions1203976
Ref: whatsnew/3 8 assignment-expressions1204085
Ref: b991204085
Ref: Assignment expressions-Footnote-11205589
Ref: Assignment expressions-Footnote-21205686
Ref: Assignment expressions-Footnote-31205728
Node: Positional-only parameters1205793
Ref: whatsnew/3 8 positional-only-parameters1205964
Ref: b9a1205964
Ref: Positional-only parameters-Footnote-11208646
Ref: Positional-only parameters-Footnote-21208708
Ref: Positional-only parameters-Footnote-31208750
Node: Parallel filesystem cache for compiled bytecode files1208815
Ref: whatsnew/3 8 parallel-filesystem-cache-for-compiled-bytecode-files1209010
Ref: b9c1209010
Ref: Parallel filesystem cache for compiled bytecode files-Footnote-11209652
Node: Debug build uses the same ABI as release build1209717
Ref: whatsnew/3 8 debug-build-uses-the-same-abi-as-release-build1209952
Ref: b9f1209952
Ref: Debug build uses the same ABI as release build-Footnote-11212309
Ref: Debug build uses the same ABI as release build-Footnote-21212374
Ref: Debug build uses the same ABI as release build-Footnote-31212439
Ref: Debug build uses the same ABI as release build-Footnote-41212504
Node: f-strings support = for self-documenting expressions and debugging1212569
Ref: whatsnew/3 8 bpo-36817-whatsnew1212785
Ref: ba11212785
Ref: whatsnew/3 8 f-strings-support-for-self-documenting-expressions-and-debugging1212785
Ref: ba21212785
Ref: f-strings support = for self-documenting expressions and debugging-Footnote-11213874
Node: PEP 578 Python Runtime Audit Hooks1213939
Ref: whatsnew/3 8 pep-578-python-runtime-audit-hooks1214152
Ref: ba31214152
Ref: PEP 578 Python Runtime Audit Hooks-Footnote-11214635
Node: PEP 587 Python Initialization Configuration1214677
Ref: whatsnew/3 8 pep-587-python-initialization-configuration1214878
Ref: ba41214878
Ref: PEP 587 Python Initialization Configuration-Footnote-11216865
Ref: PEP 587 Python Initialization Configuration-Footnote-21216907
Ref: PEP 587 Python Initialization Configuration-Footnote-31216949
Node: PEP 590 Vectorcall a fast calling protocol for CPython1217014
Ref: whatsnew/3 8 pep-590-vectorcall-a-fast-calling-protocol-for-cpython1217228
Ref: bbf1217228
Ref: PEP 590 Vectorcall a fast calling protocol for CPython-Footnote-11217836
Ref: PEP 590 Vectorcall a fast calling protocol for CPython-Footnote-21217878
Node: Pickle protocol 5 with out-of-band data buffers1217943
Ref: whatsnew/3 8 pickle-protocol-5-with-out-of-band-data-buffers1218105
Ref: bc01218105
Ref: Pickle protocol 5 with out-of-band data buffers-Footnote-11218857
Ref: Pickle protocol 5 with out-of-band data buffers-Footnote-21218899
Ref: Pickle protocol 5 with out-of-band data buffers-Footnote-31218941
Node: Other Language Changes<5>1219006
Ref: whatsnew/3 8 other-language-changes1219141
Ref: bc11219141
Ref: Other Language Changes<5>-Footnote-11226533
Ref: Other Language Changes<5>-Footnote-21226598
Ref: Other Language Changes<5>-Footnote-31226663
Ref: Other Language Changes<5>-Footnote-41226728
Ref: Other Language Changes<5>-Footnote-51226793
Ref: Other Language Changes<5>-Footnote-61226858
Ref: Other Language Changes<5>-Footnote-71226923
Ref: Other Language Changes<5>-Footnote-81226988
Ref: Other Language Changes<5>-Footnote-91227053
Ref: Other Language Changes<5>-Footnote-101227118
Ref: Other Language Changes<5>-Footnote-111227184
Ref: Other Language Changes<5>-Footnote-121227252
Ref: Other Language Changes<5>-Footnote-131227318
Ref: Other Language Changes<5>-Footnote-141227388
Ref: Other Language Changes<5>-Footnote-151227448
Ref: Other Language Changes<5>-Footnote-161227514
Ref: Other Language Changes<5>-Footnote-171227580
Node: New Modules<5>1227646
Ref: whatsnew/3 8 new-modules1227785
Ref: bca1227785
Ref: New Modules<5>-Footnote-11228863
Node: Improved Modules<5>1228928
Ref: whatsnew/3 8 improved-modules1229058
Ref: bcb1229058
Node: ast<5>1230084
Ref: whatsnew/3 8 ast1230165
Ref: bcc1230165
Ref: ast<5>-Footnote-11231195
Ref: ast<5>-Footnote-21231260
Ref: ast<5>-Footnote-31231302
Ref: ast<5>-Footnote-41231344
Ref: ast<5>-Footnote-51231386
Node: asyncio<9>1231451
Ref: whatsnew/3 8 asyncio1231552
Ref: bce1231552
Ref: asyncio<9>-Footnote-11234706
Ref: asyncio<9>-Footnote-21234771
Ref: asyncio<9>-Footnote-31234836
Ref: asyncio<9>-Footnote-41234901
Ref: asyncio<9>-Footnote-51234966
Ref: asyncio<9>-Footnote-61235031
Ref: asyncio<9>-Footnote-71235096
Ref: asyncio<9>-Footnote-81235161
Ref: asyncio<9>-Footnote-91235226
Ref: asyncio<9>-Footnote-101235279
Node: builtins<2>1235345
Ref: whatsnew/3 8 builtins1235451
Ref: bd41235451
Ref: builtins<2>-Footnote-11235950
Node: collections1236015
Ref: whatsnew/3 8 collections1236119
Ref: bd51236119
Ref: collections-Footnote-11236641
Node: cProfile1236706
Ref: whatsnew/3 8 cprofile1236805
Ref: bd71236805
Ref: cProfile-Footnote-11237155
Node: csv<2>1237220
Ref: whatsnew/3 8 csv1237317
Ref: bd91237317
Ref: csv<2>-Footnote-11237634
Node: curses<4>1237699
Ref: whatsnew/3 8 curses1237797
Ref: curses<4>-Footnote-11238041
Node: ctypes<3>1238106
Ref: whatsnew/3 8 ctypes1238209
Ref: bdd1238209
Ref: ctypes<3>-Footnote-11238698
Node: datetime<4>1238763
Ref: whatsnew/3 8 datetime1238869
Ref: be01238869
Ref: datetime<4>-Footnote-11239304
Node: functools<3>1239369
Ref: whatsnew/3 8 functools1239471
Ref: be31239471
Ref: functools<3>-Footnote-11241013
Ref: functools<3>-Footnote-21241078
Ref: functools<3>-Footnote-31241143
Node: gc<4>1241208
Ref: whatsnew/3 8 gc1241306
Ref: be81241306
Ref: gc<4>-Footnote-11241539
Node: gettext1241604
Ref: whatsnew/3 8 gettext1241697
Ref: be91241697
Ref: gettext-Footnote-11241898
Node: gzip<3>1241962
Ref: whatsnew/3 8 gzip1242069
Ref: beb1242069
Ref: gzip<3>-Footnote-11242486
Ref: gzip<3>-Footnote-21242551
Node: IDLE and idlelib<4>1242615
Ref: whatsnew/3 8 idle-and-idlelib1242725
Ref: bed1242725
Ref: IDLE and idlelib<4>-Footnote-11244692
Ref: IDLE and idlelib<4>-Footnote-21244759
Ref: IDLE and idlelib<4>-Footnote-31244823
Ref: IDLE and idlelib<4>-Footnote-41244888
Ref: IDLE and idlelib<4>-Footnote-51244953
Ref: IDLE and idlelib<4>-Footnote-61245018
Ref: IDLE and idlelib<4>-Footnote-71245082
Ref: IDLE and idlelib<4>-Footnote-81245147
Node: inspect<6>1245212
Ref: whatsnew/3 8 inspect1245320
Ref: bee1245320
Ref: inspect<6>-Footnote-11246086
Node: io<5>1246151
Ref: whatsnew/3 8 io1246252
Ref: bf01246252
Ref: io<5>-Footnote-11246600
Node: itertools<5>1246665
Ref: whatsnew/3 8 itertools1246765
Ref: bf11246765
Ref: itertools<5>-Footnote-11247143
Node: json tool1247208
Ref: whatsnew/3 8 json-tool1247313
Ref: bf31247313
Ref: json tool-Footnote-11247520
Node: logging<2>1247585
Ref: whatsnew/3 8 logging1247685
Ref: bf41247685
Ref: logging<2>-Footnote-11248400
Node: math<5>1248465
Ref: whatsnew/3 8 math1248563
Ref: bf61248563
Ref: math<5>-Footnote-11250312
Ref: math<5>-Footnote-21250377
Ref: math<5>-Footnote-31250442
Ref: math<5>-Footnote-41250507
Ref: math<5>-Footnote-51250572
Ref: math<5>-Footnote-61250637
Ref: math<5>-Footnote-71250702
Ref: math<5>-Footnote-81250767
Node: mmap<2>1250832
Ref: whatsnew/3 8 mmap1250938
Ref: bfc1250938
Ref: mmap<2>-Footnote-11251168
Node: multiprocessing<4>1251233
Ref: whatsnew/3 8 multiprocessing1251337
Ref: bfe1251337
Ref: multiprocessing<4>-Footnote-11251641
Ref: multiprocessing<4>-Footnote-21251706
Node: os<7>1251771
Ref: whatsnew/3 8 os1251878
Ref: bff1251878
Ref: os<7>-Footnote-11253402
Ref: os<7>-Footnote-21253467
Ref: os<7>-Footnote-31253532
Node: os path<5>1253597
Ref: whatsnew/3 8 os-path1253697
Ref: c041253697
Ref: os path<5>-Footnote-11254720
Ref: os path<5>-Footnote-21254785
Ref: os path<5>-Footnote-31254850
Node: pathlib<10>1254915
Ref: whatsnew/3 8 pathlib1255019
Ref: c0c1255019
Ref: pathlib<10>-Footnote-11255928
Ref: pathlib<10>-Footnote-21255993
Node: pickle<2>1256058
Ref: whatsnew/3 8 pickle1256160
Ref: c141256160
Ref: pickle<2>-Footnote-11256498
Node: plistlib1256563
Ref: whatsnew/3 8 plistlib1256663
Ref: c171256663
Ref: plistlib-Footnote-11256901
Node: pprint<3>1256966
Ref: whatsnew/3 8 pprint1257070
Ref: c191257070
Ref: pprint<3>-Footnote-11258135
Node: py_compile<2>1258200
Ref: whatsnew/3 8 py-compile1258301
Ref: c1b1258301
Ref: py_compile<2>-Footnote-11258490
Node: shlex1258555
Ref: whatsnew/3 8 shlex1258656
Ref: c1d1258656
Ref: shlex-Footnote-11258860
Node: shutil<4>1258925
Ref: whatsnew/3 8 shutil1259022
Ref: c1f1259022
Ref: shutil<4>-Footnote-11259675
Ref: shutil<4>-Footnote-21259740
Ref: shutil<4>-Footnote-31259805
Node: socket<5>1259870
Ref: whatsnew/3 8 socket1259968
Ref: c211259968
Ref: socket<5>-Footnote-11260543
Ref: socket<5>-Footnote-21260608
Node: ssl<5>1260673
Ref: whatsnew/3 8 ssl1260775
Ref: c271260775
Ref: ssl<5>-Footnote-11261037
Node: statistics<3>1261102
Ref: whatsnew/3 8 statistics1261201
Ref: c2a1261201
Ref: statistics<3>-Footnote-11262932
Ref: statistics<3>-Footnote-21262997
Ref: statistics<3>-Footnote-31263062
Ref: statistics<3>-Footnote-41263127
Ref: statistics<3>-Footnote-51263192
Node: sys<7>1263257
Ref: whatsnew/3 8 sys1263360
Ref: c301263360
Ref: sys<7>-Footnote-11263801
Node: tarfile<5>1263866
Ref: whatsnew/3 8 tarfile1263968
Ref: c311263968
Ref: tarfile<5>-Footnote-11264386
Node: threading<5>1264451
Ref: whatsnew/3 8 threading1264558
Ref: c321264558
Ref: threading<5>-Footnote-11265294
Ref: threading<5>-Footnote-21265361
Node: tokenize<2>1265426
Ref: whatsnew/3 8 tokenize1265533
Ref: c361265533
Ref: tokenize<2>-Footnote-11265859
Node: tkinter<5>1265924
Ref: whatsnew/3 8 tkinter1266026
Ref: c371266026
Ref: tkinter<5>-Footnote-11266569
Ref: tkinter<5>-Footnote-21266634
Ref: tkinter<5>-Footnote-31266699
Node: time<4>1266764
Ref: whatsnew/3 8 time1266864
Ref: c381266864
Ref: time<4>-Footnote-11267043
Node: typing<9>1267108
Ref: whatsnew/3 8 typing1267212
Ref: c3a1267212
Ref: typing<9>-Footnote-11268682
Ref: typing<9>-Footnote-21268724
Ref: typing<9>-Footnote-31268766
Ref: typing<9>-Footnote-41268808
Node: unicodedata<6>1268850
Ref: whatsnew/3 8 unicodedata1268958
Ref: c3d1268958
Ref: unicodedata<6>-Footnote-11269387
Ref: unicodedata<6>-Footnote-21269449
Ref: unicodedata<6>-Footnote-31269514
Node: unittest<7>1269579
Ref: whatsnew/3 8 unittest1269685
Ref: c3f1269685
Ref: unittest<7>-Footnote-11270981
Ref: unittest<7>-Footnote-21271046
Ref: unittest<7>-Footnote-31271111
Ref: unittest<7>-Footnote-41271176
Node: venv<4>1271241
Ref: whatsnew/3 8 venv1271340
Ref: c461271340
Ref: venv<4>-Footnote-11271592
Node: weakref1271657
Ref: whatsnew/3 8 weakref1271751
Ref: c471271751
Ref: weakref-Footnote-11272044
Node: xml<4>1272109
Ref: whatsnew/3 8 xml1272202
Ref: c491272202
Ref: xml<4>-Footnote-11273358
Ref: xml<4>-Footnote-21273423
Ref: xml<4>-Footnote-31273488
Ref: xml<4>-Footnote-41273553
Ref: xml<4>-Footnote-51273618
Node: xmlrpc1273683
Ref: whatsnew/3 8 xmlrpc1273760
Ref: c4d1273760
Ref: xmlrpc-Footnote-11274152
Node: Optimizations<6>1274217
Ref: whatsnew/3 8 optimizations1274356
Ref: c4f1274356
Ref: Optimizations<6>-Footnote-11278722
Ref: Optimizations<6>-Footnote-21278787
Ref: Optimizations<6>-Footnote-31278852
Ref: Optimizations<6>-Footnote-41278917
Ref: Optimizations<6>-Footnote-51278982
Ref: Optimizations<6>-Footnote-61279047
Ref: Optimizations<6>-Footnote-71279112
Ref: Optimizations<6>-Footnote-81279177
Ref: Optimizations<6>-Footnote-91279242
Ref: Optimizations<6>-Footnote-101279307
Ref: Optimizations<6>-Footnote-111279373
Ref: Optimizations<6>-Footnote-121279439
Ref: Optimizations<6>-Footnote-131279505
Node: Build and C API Changes1279571
Ref: whatsnew/3 8 build-and-c-api-changes1279704
Ref: c5a1279704
Ref: Build and C API Changes-Footnote-11285281
Ref: Build and C API Changes-Footnote-21285346
Ref: Build and C API Changes-Footnote-31285411
Ref: Build and C API Changes-Footnote-41285476
Ref: Build and C API Changes-Footnote-51285541
Ref: Build and C API Changes-Footnote-61285606
Ref: Build and C API Changes-Footnote-71285671
Ref: Build and C API Changes-Footnote-81285736
Ref: Build and C API Changes-Footnote-91285801
Ref: Build and C API Changes-Footnote-101285866
Ref: Build and C API Changes-Footnote-111285932
Ref: Build and C API Changes-Footnote-121285998
Node: Deprecated<7>1286064
Ref: whatsnew/3 8 deprecated1286205
Ref: c641286205
Ref: Deprecated<7>-Footnote-11292071
Ref: Deprecated<7>-Footnote-21292136
Ref: Deprecated<7>-Footnote-31292201
Ref: Deprecated<7>-Footnote-41292266
Ref: Deprecated<7>-Footnote-51292330
Ref: Deprecated<7>-Footnote-61292395
Ref: Deprecated<7>-Footnote-71292460
Ref: Deprecated<7>-Footnote-81292525
Ref: Deprecated<7>-Footnote-91292590
Ref: Deprecated<7>-Footnote-101292655
Ref: Deprecated<7>-Footnote-111292721
Ref: Deprecated<7>-Footnote-121292787
Ref: Deprecated<7>-Footnote-131292853
Node: API and Feature Removals1292919
Ref: whatsnew/3 8 api-and-feature-removals1293058
Ref: c7b1293058
Ref: API and Feature Removals-Footnote-11295878
Ref: API and Feature Removals-Footnote-21295933
Ref: API and Feature Removals-Footnote-31295998
Ref: API and Feature Removals-Footnote-41296063
Ref: API and Feature Removals-Footnote-51296128
Ref: API and Feature Removals-Footnote-61296193
Ref: API and Feature Removals-Footnote-71296258
Ref: API and Feature Removals-Footnote-81296323
Ref: API and Feature Removals-Footnote-91296388
Ref: API and Feature Removals-Footnote-101296453
Ref: API and Feature Removals-Footnote-111296519
Node: Porting to Python 3 81296585
Ref: whatsnew/3 8 porting-to-python-3-81296742
Ref: c7e1296742
Node: Changes in Python behavior1297134
Ref: whatsnew/3 8 changes-in-python-behavior1297255
Ref: c7f1297255
Ref: Changes in Python behavior-Footnote-11299622
Ref: Changes in Python behavior-Footnote-21299687
Ref: Changes in Python behavior-Footnote-31299752
Ref: Changes in Python behavior-Footnote-41299817
Ref: Changes in Python behavior-Footnote-51299882
Ref: Changes in Python behavior-Footnote-61299947
Node: Changes in the Python API<5>1300012
Ref: whatsnew/3 8 changes-in-the-python-api1300165
Ref: c831300165
Ref: whatsnew/3 8 bpo-36085-whatsnew1307208
Ref: c971307208
Ref: Changes in the Python API<5>-Footnote-11308868
Ref: Changes in the Python API<5>-Footnote-21308910
Ref: Changes in the Python API<5>-Footnote-31308975
Ref: Changes in the Python API<5>-Footnote-41309040
Ref: Changes in the Python API<5>-Footnote-51309105
Ref: Changes in the Python API<5>-Footnote-61309170
Ref: Changes in the Python API<5>-Footnote-71309235
Ref: Changes in the Python API<5>-Footnote-81309300
Ref: Changes in the Python API<5>-Footnote-91309365
Ref: Changes in the Python API<5>-Footnote-101309430
Ref: Changes in the Python API<5>-Footnote-111309496
Ref: Changes in the Python API<5>-Footnote-121309562
Ref: Changes in the Python API<5>-Footnote-131309628
Ref: Changes in the Python API<5>-Footnote-141309694
Ref: Changes in the Python API<5>-Footnote-151309760
Ref: Changes in the Python API<5>-Footnote-161309826
Ref: Changes in the Python API<5>-Footnote-171309892
Ref: Changes in the Python API<5>-Footnote-181309957
Ref: Changes in the Python API<5>-Footnote-191310023
Ref: Changes in the Python API<5>-Footnote-201310089
Ref: Changes in the Python API<5>-Footnote-211310155
Ref: Changes in the Python API<5>-Footnote-221310221
Ref: Changes in the Python API<5>-Footnote-231310287
Ref: Changes in the Python API<5>-Footnote-241310353
Ref: Changes in the Python API<5>-Footnote-251310419
Ref: Changes in the Python API<5>-Footnote-261310485
Ref: Changes in the Python API<5>-Footnote-271310551
Node: Changes in the C API<5>1310594
Ref: whatsnew/3 8 changes-in-the-c-api1310748
Ref: c991310748
Ref: Changes in the C API<5>-Footnote-11316586
Ref: Changes in the C API<5>-Footnote-21316651
Ref: Changes in the C API<5>-Footnote-31316716
Ref: Changes in the C API<5>-Footnote-41316781
Ref: Changes in the C API<5>-Footnote-51316846
Ref: Changes in the C API<5>-Footnote-61316911
Ref: Changes in the C API<5>-Footnote-71316976
Ref: Changes in the C API<5>-Footnote-81317041
Node: CPython bytecode changes<5>1317106
Ref: whatsnew/3 8 cpython-bytecode-changes1317247
Ref: ca11317247
Ref: CPython bytecode changes<5>-Footnote-11318572
Ref: CPython bytecode changes<5>-Footnote-21318637
Ref: CPython bytecode changes<5>-Footnote-31318702
Ref: CPython bytecode changes<5>-Footnote-41318744
Node: Demos and Tools1318809
Ref: whatsnew/3 8 demos-and-tools1318918
Ref: ca51318918
Ref: Demos and Tools-Footnote-11322215
Ref: Demos and Tools-Footnote-21322280
Ref: Demos and Tools-Footnote-31322408
Node: Notable changes in Python 3 8 11322456
Ref: whatsnew/3 8 notable-changes-in-python-3-8-11322620
Ref: ca61322620
Ref: Notable changes in Python 3 8 1-Footnote-11323131
Node: Notable changes in Python 3 8 21323196
Ref: whatsnew/3 8 notable-changes-in-python-3-8-21323370
Ref: ca71323370
Ref: Notable changes in Python 3 8 2-Footnote-11323692
Node: Notable changes in Python 3 8 31323747
Ref: whatsnew/3 8 notable-changes-in-python-3-8-31323921
Ref: ca81323921
Ref: Notable changes in Python 3 8 3-Footnote-11324308
Node: Notable changes in Python 3 8 81324363
Ref: whatsnew/3 8 notable-changes-in-python-3-8-81324537
Ref: ca91324537
Ref: Notable changes in Python 3 8 8-Footnote-11325255
Node: Notable changes in Python 3 8 91325320
Ref: whatsnew/3 8 notable-changes-in-python-3-8-91325495
Ref: caa1325495
Ref: Notable changes in Python 3 8 9-Footnote-11325966
Node: Notable changes in Python 3 8 101326021
Ref: whatsnew/3 8 notable-changes-in-python-3-8-101326200
Ref: cab1326200
Node: macOS 11 0 Big Sur and Apple Silicon Mac support<2>1326398
Ref: whatsnew/3 8 macos-11-0-big-sur-and-apple-silicon-mac-support1326518
Ref: cac1326518
Ref: macOS 11 0 Big Sur and Apple Silicon Mac support<2>-Footnote-11327493
Node: Notable changes in Python 3 8 10<2>1327548
Ref: whatsnew/3 8 id11327728
Ref: cad1327728
Node: urllib parse<4>1327852
Ref: whatsnew/3 8 urllib-parse1327939
Ref: cae1327939
Ref: urllib parse<4>-Footnote-11328469
Ref: urllib parse<4>-Footnote-21328528
Node: Notable changes in Python 3 8 121328593
Ref: whatsnew/3 8 notable-changes-in-python-3-8-121328775
Ref: caf1328775
Node: Changes in the Python API<6>1328925
Ref: whatsnew/3 8 id21329022
Ref: cb01329022
Ref: Changes in the Python API<6>-Footnote-11329633
Node: Notable security feature in 3 8 141329698
Ref: whatsnew/3 8 notable-security-feature-in-3-8-141329870
Ref: cb11329870
Ref: Notable security feature in 3 8 14-Footnote-11330600
Node: Notable changes in 3 8 171330656
Ref: whatsnew/3 8 notable-changes-in-3-8-171330787
Ref: cb21330787
Node: tarfile<6>1330887
Ref: whatsnew/3 8 id31330959
Ref: cb31330959
Ref: tarfile<6>-Footnote-11331563
Node: What’s New In Python 3 71331605
Ref: whatsnew/3 7 doc1331755
Ref: cb41331755
Ref: whatsnew/3 7 translation-repo1331755
Ref: cb51331755
Ref: whatsnew/3 7 what-s-new-in-python-3-71331755
Ref: cb61331755
Node: Summary – Release Highlights<2>1333230
Ref: whatsnew/3 7 summary-release-highlights1333351
Ref: cb71333351
Ref: Summary – Release Highlights<2>-Footnote-11335498
Ref: Summary – Release Highlights<2>-Footnote-21335578
Ref: Summary – Release Highlights<2>-Footnote-31335614
Ref: Summary – Release Highlights<2>-Footnote-41335650
Node: New Features<10>1335686
Ref: whatsnew/3 7 new-features1335841
Ref: ccb1335841
Node: PEP 563 Postponed Evaluation of Annotations1336938
Ref: whatsnew/3 7 pep-563-postponed-evaluation-of-annotations1337075
Ref: ccc1337075
Ref: whatsnew/3 7 whatsnew37-pep5631337075
Ref: cb81337075
Ref: PEP 563 Postponed Evaluation of Annotations-Footnote-11338843
Ref: PEP 563 Postponed Evaluation of Annotations-Footnote-21338885
Ref: PEP 563 Postponed Evaluation of Annotations-Footnote-31338927
Node: PEP 538 Legacy C Locale Coercion1338969
Ref: whatsnew/3 7 pep-538-legacy-c-locale-coercion1339148
Ref: ccd1339148
Ref: whatsnew/3 7 whatsnew37-pep5381339148
Ref: cc21339148
Ref: PEP 538 Legacy C Locale Coercion-Footnote-11341537
Ref: PEP 538 Legacy C Locale Coercion-Footnote-21341579
Ref: PEP 538 Legacy C Locale Coercion-Footnote-31341621
Ref: PEP 538 Legacy C Locale Coercion-Footnote-41341663
Node: PEP 540 Forced UTF-8 Runtime Mode1341705
Ref: whatsnew/3 7 pep-540-forced-utf-8-runtime-mode1341868
Ref: cd01341868
Ref: whatsnew/3 7 whatsnew37-pep5401341868
Ref: cc31341868
Ref: PEP 540 Forced UTF-8 Runtime Mode-Footnote-11343436
Ref: PEP 540 Forced UTF-8 Runtime Mode-Footnote-21343478
Ref: PEP 540 Forced UTF-8 Runtime Mode-Footnote-31343520
Node: PEP 553 Built-in breakpoint1343562
Ref: whatsnew/3 7 pep-553-built-in-breakpoint1343735
Ref: cd21343735
Ref: whatsnew/3 7 whatsnew37-pep5531343735
Ref: cbc1343735
Ref: PEP 553 Built-in breakpoint-Footnote-11344578
Node: PEP 539 New C API for Thread-Local Storage1344620
Ref: whatsnew/3 7 pep-539-new-c-api-for-thread-local-storage1344812
Ref: cd51344812
Ref: whatsnew/3 7 whatsnew37-pep5391344812
Ref: cc71344812
Ref: PEP 539 New C API for Thread-Local Storage-Footnote-11346311
Ref: PEP 539 New C API for Thread-Local Storage-Footnote-21346353
Node: PEP 562 Customization of Access to Module Attributes1346395
Ref: whatsnew/3 7 pep-562-customization-of-access-to-module-attributes1346613
Ref: cd91346613
Ref: whatsnew/3 7 whatsnew37-pep5621346613
Ref: cbd1346613
Ref: PEP 562 Customization of Access to Module Attributes-Footnote-11347204
Node: PEP 564 New Time Functions With Nanosecond Resolution1347246
Ref: whatsnew/3 7 pep-564-new-time-functions-with-nanosecond-resolution1347465
Ref: cdc1347465
Ref: whatsnew/3 7 whatsnew37-pep5641347465
Ref: cc11347465
Ref: PEP 564 New Time Functions With Nanosecond Resolution-Footnote-11348552
Ref: PEP 564 New Time Functions With Nanosecond Resolution-Footnote-21348594
Ref: PEP 564 New Time Functions With Nanosecond Resolution-Footnote-31348671
Node: PEP 565 Show DeprecationWarning in __main__1348713
Ref: whatsnew/3 7 pep-565-show-deprecationwarning-in-main1348936
Ref: ce31348936
Ref: whatsnew/3 7 whatsnew37-pep5651348936
Ref: cc61348936
Ref: PEP 565 Show DeprecationWarning in __main__-Footnote-11350872
Node: PEP 560 Core Support for typing module and Generic Types1350914
Ref: whatsnew/3 7 pep-560-core-support-for-typing-module-and-generic-types1351112
Ref: ce41351112
Ref: whatsnew/3 7 whatsnew37-pep5601351112
Ref: cbe1351112
Ref: PEP 560 Core Support for typing module and Generic Types-Footnote-11352079
Ref: PEP 560 Core Support for typing module and Generic Types-Footnote-21352121
Node: PEP 552 Hash-based pyc Files1352163
Ref: whatsnew/3 7 pep-552-hash-based-pyc-files1352359
Ref: ce61352359
Ref: whatsnew/3 7 whatsnew37-pep5521352359
Ref: cc41352359
Ref: PEP 552 Hash-based pyc Files-Footnote-11354035
Ref: PEP 552 Hash-based pyc Files-Footnote-21354076
Ref: PEP 552 Hash-based pyc Files-Footnote-31354118
Node: PEP 545 Python Documentation Translations1354160
Ref: whatsnew/3 7 pep-545-python-documentation-translations1354330
Ref: ce71354330
Ref: whatsnew/3 7 whatsnew37-pep5451354330
Ref: cc81354330
Ref: PEP 545 Python Documentation Translations-Footnote-11354918
Ref: PEP 545 Python Documentation Translations-Footnote-21354960
Node: Python Development Mode -X dev1355002
Ref: whatsnew/3 7 python-development-mode-x-dev1355135
Ref: ce81355135
Ref: whatsnew/3 7 whatsnew37-devmode1355135
Ref: cc51355135
Node: Other Language Changes<6>1355589
Ref: whatsnew/3 7 other-language-changes1355725
Ref: cea1355725
Ref: Other Language Changes<6>-Footnote-11358117
Ref: Other Language Changes<6>-Footnote-21358182
Ref: Other Language Changes<6>-Footnote-31358247
Ref: Other Language Changes<6>-Footnote-41358312
Ref: Other Language Changes<6>-Footnote-51358377
Ref: Other Language Changes<6>-Footnote-61358442
Ref: Other Language Changes<6>-Footnote-71358507
Ref: Other Language Changes<6>-Footnote-81358572
Ref: Other Language Changes<6>-Footnote-91358637
Ref: Other Language Changes<6>-Footnote-101358702
Node: New Modules<6>1358768
Ref: whatsnew/3 7 new-modules1358907
Ref: cf01358907
Node: contextvars<2>1359063
Ref: whatsnew/3 7 contextvars1359151
Ref: cf11359151
Ref: whatsnew/3 7 whatsnew37-pep5671359151
Ref: cb91359151
Ref: contextvars<2>-Footnote-11359884
Node: dataclasses<3>1359926
Ref: whatsnew/3 7 dataclasses1360045
Ref: cf31360045
Ref: whatsnew/3 7 whatsnew37-pep5571360045
Ref: cba1360045
Ref: dataclasses<3>-Footnote-11360720
Node: importlib resources<2>1360762
Ref: whatsnew/3 7 importlib-resources1360858
Ref: cf61360858
Ref: whatsnew/3 7 whatsnew37-importlib-resources1360858
Ref: cbb1360858
Ref: importlib resources<2>-Footnote-11361604
Ref: importlib resources<2>-Footnote-21361669
Node: Improved Modules<6>1361731
Ref: whatsnew/3 7 improved-modules1361861
Ref: cf71361861
Node: argparse<5>1363321
Ref: whatsnew/3 7 argparse1363408
Ref: cf81363408
Ref: argparse<5>-Footnote-11363642
Node: asyncio<10>1363707
Ref: whatsnew/3 7 asyncio1363811
Ref: cfa1363811
Ref: whatsnew/3 7 whatsnew37-asyncio1363811
Ref: cc01363811
Ref: asyncio<10>-Footnote-11370102
Ref: asyncio<10>-Footnote-21370167
Ref: asyncio<10>-Footnote-31370209
Ref: asyncio<10>-Footnote-41370274
Ref: asyncio<10>-Footnote-51370339
Ref: asyncio<10>-Footnote-61370404
Ref: asyncio<10>-Footnote-71370469
Ref: asyncio<10>-Footnote-81370534
Ref: asyncio<10>-Footnote-91370599
Ref: asyncio<10>-Footnote-101370664
Ref: asyncio<10>-Footnote-111370730
Ref: asyncio<10>-Footnote-121370796
Ref: asyncio<10>-Footnote-131370862
Ref: asyncio<10>-Footnote-141370928
Ref: asyncio<10>-Footnote-151370994
Ref: asyncio<10>-Footnote-161371060
Ref: asyncio<10>-Footnote-171371126
Ref: asyncio<10>-Footnote-181371192
Ref: asyncio<10>-Footnote-191371258
Ref: asyncio<10>-Footnote-201371324
Ref: asyncio<10>-Footnote-211371390
Ref: asyncio<10>-Footnote-221371456
Ref: asyncio<10>-Footnote-231371522
Ref: asyncio<10>-Footnote-241371588
Node: binascii1371654
Ref: whatsnew/3 7 binascii1371758
Ref: d171371758
Ref: binascii-Footnote-11372037
Node: calendar<3>1372102
Ref: whatsnew/3 7 calendar1372209
Ref: d191372209
Ref: calendar<3>-Footnote-11372459
Node: collections<2>1372524
Ref: whatsnew/3 7 collections1372636
Ref: d1b1372636
Ref: collections<2>-Footnote-11372827
Node: compileall<3>1372892
Ref: whatsnew/3 7 compileall1373014
Ref: d1c1373014
Ref: compileall<3>-Footnote-11373411
Node: concurrent futures<4>1373476
Ref: whatsnew/3 7 concurrent-futures1373597
Ref: d1e1373597
Ref: concurrent futures<4>-Footnote-11374039
Ref: concurrent futures<4>-Footnote-21374104
Node: contextlib<3>1374169
Ref: whatsnew/3 7 contextlib1374288
Ref: d1f1374288
Ref: contextlib<3>-Footnote-11374818
Ref: contextlib<3>-Footnote-21374883
Ref: contextlib<3>-Footnote-31374948
Ref: contextlib<3>-Footnote-41375013
Node: cProfile<2>1375078
Ref: whatsnew/3 7 cprofile1375181
Ref: d241375181
Ref: cProfile<2>-Footnote-11375407
Node: crypt1375472
Ref: whatsnew/3 7 crypt1375573
Ref: d251375573
Ref: crypt-Footnote-11375894
Ref: crypt-Footnote-21375959
Node: datetime<5>1376024
Ref: whatsnew/3 7 datetime1376120
Ref: d261376120
Ref: datetime<5>-Footnote-11376531
Ref: datetime<5>-Footnote-21376596
Node: dbm<2>1376660
Ref: whatsnew/3 7 dbm1376761
Ref: d281376761
Node: decimal<2>1376906
Ref: whatsnew/3 7 decimal1377002
Ref: d291377002
Ref: decimal<2>-Footnote-11377223
Node: dis<4>1377288
Ref: whatsnew/3 7 dis1377390
Ref: d2a1377390
Ref: dis<4>-Footnote-11377793
Node: distutils<4>1377858
Ref: whatsnew/3 7 distutils1377957
Ref: d2b1377957
Ref: distutils<4>-Footnote-11378205
Node: enum<5>1378270
Ref: whatsnew/3 7 enum1378375
Ref: d2c1378375
Ref: enum<5>-Footnote-11379056
Ref: enum<5>-Footnote-21379121
Node: functools<4>1379186
Ref: whatsnew/3 7 functools1379284
Ref: d2e1379284
Ref: functools<4>-Footnote-11379513
Node: gc<5>1379578
Ref: whatsnew/3 7 gc1379676
Ref: d2f1379676
Ref: gc<5>-Footnote-11380215
Node: hmac<3>1380280
Ref: whatsnew/3 7 hmac1380377
Ref: d331380377
Ref: hmac<3>-Footnote-11380640
Node: http client1380705
Ref: whatsnew/3 7 http-client1380808
Ref: d361380808
Ref: http client-Footnote-11381065
Node: http server1381130
Ref: whatsnew/3 7 http-server1381242
Ref: d391381242
Ref: http server-Footnote-11382125
Ref: http server-Footnote-21382190
Ref: http server-Footnote-31382255
Node: idlelib and IDLE1382320
Ref: whatsnew/3 7 idlelib-and-idle1382433
Ref: d3d1382433
Ref: idlelib and IDLE-Footnote-11385440
Ref: idlelib and IDLE-Footnote-21385505
Ref: idlelib and IDLE-Footnote-31385572
Ref: idlelib and IDLE-Footnote-41385637
Ref: idlelib and IDLE-Footnote-51385702
Ref: idlelib and IDLE-Footnote-61385767
Ref: idlelib and IDLE-Footnote-71385832
Ref: idlelib and IDLE-Footnote-81385897
Ref: idlelib and IDLE-Footnote-91385962
Ref: idlelib and IDLE-Footnote-101386027
Ref: idlelib and IDLE-Footnote-111386095
Ref: idlelib and IDLE-Footnote-121386160
Ref: idlelib and IDLE-Footnote-131386226
Node: importlib<4>1386292
Ref: whatsnew/3 7 importlib1386399
Ref: d3e1386399
Ref: importlib<4>-Footnote-11387286
Ref: importlib<4>-Footnote-21387351
Ref: importlib<4>-Footnote-31387416
Node: io<6>1387481
Ref: whatsnew/3 7 io1387584
Ref: d411387584
Ref: io<6>-Footnote-11387849
Ref: io<6>-Footnote-21387914
Node: ipaddress<3>1387979
Ref: whatsnew/3 7 ipaddress1388082
Ref: d431388082
Ref: ipaddress<3>-Footnote-11388402
Node: itertools<6>1388467
Ref: whatsnew/3 7 itertools1388574
Ref: d441388574
Ref: itertools<6>-Footnote-11388811
Node: locale<4>1388876
Ref: whatsnew/3 7 locale1388981
Ref: d461388981
Ref: locale<4>-Footnote-11389395
Node: logging<3>1389460
Ref: whatsnew/3 7 logging1389560
Ref: d471389560
Ref: logging<3>-Footnote-11390084
Ref: logging<3>-Footnote-21390149
Ref: logging<3>-Footnote-31390214
Node: math<6>1390279
Ref: whatsnew/3 7 math1390382
Ref: d4b1390382
Ref: math<6>-Footnote-11390595
Node: mimetypes<3>1390660
Ref: whatsnew/3 7 mimetypes1390759
Ref: d4d1390759
Ref: mimetypes<3>-Footnote-11390974
Node: msilib1391039
Ref: whatsnew/3 7 msilib1391149
Ref: d4e1391149
Ref: msilib-Footnote-11391344
Node: multiprocessing<5>1391409
Ref: whatsnew/3 7 multiprocessing1391512
Ref: d4f1391512
Ref: multiprocessing<5>-Footnote-11392165
Ref: multiprocessing<5>-Footnote-21392230
Ref: multiprocessing<5>-Footnote-31392295
Node: os<8>1392360
Ref: whatsnew/3 7 os1392468
Ref: d531392468
Ref: os<8>-Footnote-11393766
Ref: os<8>-Footnote-21393831
Ref: os<8>-Footnote-31393896
Ref: os<8>-Footnote-41393961
Ref: os<8>-Footnote-51394026
Ref: os<8>-Footnote-61394091
Ref: os<8>-Footnote-71394156
Node: pathlib<11>1394221
Ref: whatsnew/3 7 pathlib1394317
Ref: d5e1394317
Ref: pathlib<11>-Footnote-11394577
Node: pdb<6>1394642
Ref: whatsnew/3 7 pdb1394746
Ref: d5f1394746
Ref: pdb<6>-Footnote-11395156
Ref: pdb<6>-Footnote-21395221
Node: py_compile<3>1395286
Ref: whatsnew/3 7 py-compile1395387
Ref: d601395387
Ref: py_compile<3>-Footnote-11395841
Ref: py_compile<3>-Footnote-21395882
Node: pydoc<3>1395947
Ref: whatsnew/3 7 pydoc1396050
Ref: d611396050
Ref: pydoc<3>-Footnote-11396274
Node: queue<2>1396339
Ref: whatsnew/3 7 queue1396434
Ref: d621396434
Ref: queue<2>-Footnote-11396617
Node: re<5>1396682
Ref: whatsnew/3 7 re1396778
Ref: d641396778
Ref: re<5>-Footnote-11397860
Ref: re<5>-Footnote-21397925
Ref: re<5>-Footnote-31397990
Ref: re<5>-Footnote-41398055
Ref: re<5>-Footnote-51398120
Node: signal<2>1398185
Ref: whatsnew/3 7 signal1398282
Ref: d681398282
Ref: signal<2>-Footnote-11398601
Node: socket<6>1398666
Ref: whatsnew/3 7 socket1398770
Ref: d6a1398770
Ref: socket<6>-Footnote-11399876
Ref: socket<6>-Footnote-21399941
Ref: socket<6>-Footnote-31400006
Ref: socket<6>-Footnote-41400071
Ref: socket<6>-Footnote-51400136
Ref: socket<6>-Footnote-61400201
Node: socketserver1400266
Ref: whatsnew/3 7 socketserver1400371
Ref: d701400371
Node: sqlite3<7>1400861
Ref: whatsnew/3 7 sqlite31400963
Ref: d741400963
Ref: sqlite3<7>-Footnote-11401405
Ref: sqlite3<7>-Footnote-21401470
Node: ssl<6>1401535
Ref: whatsnew/3 7 ssl1401634
Ref: d761401634
Ref: ssl<6>-Footnote-11404900
Ref: ssl<6>-Footnote-21404965
Ref: ssl<6>-Footnote-31405030
Ref: ssl<6>-Footnote-41405095
Ref: ssl<6>-Footnote-51405160
Ref: ssl<6>-Footnote-61405225
Ref: ssl<6>-Footnote-71405290
Ref: ssl<6>-Footnote-81405355
Ref: ssl<6>-Footnote-91405420
Ref: ssl<6>-Footnote-101405485
Ref: ssl<6>-Footnote-111405551
Ref: ssl<6>-Footnote-121405617
Ref: ssl<6>-Footnote-131405683
Ref: ssl<6>-Footnote-141405749
Node: string<2>1405805
Ref: whatsnew/3 7 string1405907
Ref: d7f1405907
Ref: string<2>-Footnote-11406184
Node: subprocess<2>1406251
Ref: whatsnew/3 7 subprocess1406353
Ref: d801406353
Ref: subprocess<2>-Footnote-11407675
Ref: subprocess<2>-Footnote-21407740
Ref: subprocess<2>-Footnote-31407805
Ref: subprocess<2>-Footnote-41407870
Node: sys<8>1407935
Ref: whatsnew/3 7 sys1408035
Ref: d841408035
Ref: sys<8>-Footnote-11408775
Ref: sys<8>-Footnote-21408840
Ref: sys<8>-Footnote-31408905
Node: time<5>1408970
Ref: whatsnew/3 7 time1409067
Ref: d881409067
Ref: time<5>-Footnote-11410276
Ref: time<5>-Footnote-21410318
Node: tkinter<6>1410383
Ref: whatsnew/3 7 tkinter1410488
Ref: d8e1410488
Ref: tkinter<6>-Footnote-11410669
Node: tracemalloc<2>1410734
Ref: whatsnew/3 7 tracemalloc1410840
Ref: d901410840
Ref: tracemalloc<2>-Footnote-11411306
Node: types<5>1411371
Ref: whatsnew/3 7 types1411481
Ref: d931411481
Ref: types<5>-Footnote-11411996
Ref: types<5>-Footnote-21412061
Ref: types<5>-Footnote-31412126
Ref: types<5>-Footnote-41412168
Node: unicodedata<7>1412233
Ref: whatsnew/3 7 unicodedata1412340
Ref: d981412340
Ref: unicodedata<7>-Footnote-11412543
Node: unittest<8>1412599
Ref: whatsnew/3 7 unittest1412711
Ref: d991412711
Ref: unittest<8>-Footnote-11413116
Node: unittest mock1413181
Ref: whatsnew/3 7 unittest-mock1413294
Ref: d9a1413294
Ref: unittest mock-Footnote-11413812
Ref: unittest mock-Footnote-21413877
Node: urllib parse<5>1413942
Ref: whatsnew/3 7 urllib-parse1414046
Ref: d9d1414046
Ref: urllib parse<5>-Footnote-11414359
Ref: urllib parse<5>-Footnote-21414418
Ref: urllib parse<5>-Footnote-31414477
Node: uu1414542
Ref: whatsnew/3 7 uu1414640
Ref: d9f1414640
Ref: uu-Footnote-11414906
Node: uuid<4>1414971
Ref: whatsnew/3 7 uuid1415065
Ref: da01415065
Ref: uuid<4>-Footnote-11415705
Ref: uuid<4>-Footnote-21415770
Node: warnings<3>1415835
Ref: whatsnew/3 7 warnings1415933
Ref: da41415933
Ref: warnings<3>-Footnote-11417358
Ref: warnings<3>-Footnote-21417423
Ref: warnings<3>-Footnote-31417488
Ref: warnings<3>-Footnote-41417553
Node: xml<5>1417618
Ref: whatsnew/3 7 xml1417718
Ref: da61417718
Ref: xml<5>-Footnote-11418002
Node: xml etree1418057
Ref: whatsnew/3 7 xml-etree1418159
Ref: da71418159
Ref: xml etree-Footnote-11418500
Node: xmlrpc server1418565
Ref: whatsnew/3 7 xmlrpc-server1418667
Ref: da91418667
Ref: xmlrpc server-Footnote-11418878
Node: zipapp1418942
Ref: whatsnew/3 7 zipapp1419045
Ref: daa1419045
Ref: zipapp-Footnote-11419569
Ref: zipapp-Footnote-21419634
Node: zipfile<3>1419699
Ref: whatsnew/3 7 zipfile1419780
Ref: dac1419780
Ref: zipfile<3>-Footnote-11420145
Ref: zipfile<3>-Footnote-21420210
Node: C API Changes<5>1420275
Ref: whatsnew/3 7 c-api-changes1420407
Ref: dad1420407
Ref: C API Changes<5>-Footnote-11424908
Ref: C API Changes<5>-Footnote-21424973
Ref: C API Changes<5>-Footnote-31425038
Ref: C API Changes<5>-Footnote-41425103
Ref: C API Changes<5>-Footnote-51425168
Ref: C API Changes<5>-Footnote-61425233
Ref: C API Changes<5>-Footnote-71425298
Ref: C API Changes<5>-Footnote-81425363
Ref: C API Changes<5>-Footnote-91425428
Ref: C API Changes<5>-Footnote-101425493
Ref: C API Changes<5>-Footnote-111425559
Ref: C API Changes<5>-Footnote-121425625
Ref: C API Changes<5>-Footnote-131425691
Ref: C API Changes<5>-Footnote-141425757
Ref: C API Changes<5>-Footnote-151425823
Ref: C API Changes<5>-Footnote-161425888
Ref: C API Changes<5>-Footnote-171425954
Ref: C API Changes<5>-Footnote-181426020
Ref: C API Changes<5>-Footnote-191426086
Ref: C API Changes<5>-Footnote-201426152
Node: Build Changes<5>1426218
Ref: whatsnew/3 7 build-changes1426347
Ref: dc61426347
Ref: Build Changes<5>-Footnote-11427480
Ref: Build Changes<5>-Footnote-21427545
Ref: Build Changes<5>-Footnote-31427610
Node: Optimizations<7>1427675
Ref: whatsnew/3 7 optimizations1427827
Ref: dc71427827
Ref: whatsnew/3 7 whatsnew37-perf1427827
Ref: cc91427827
Ref: whatsnew/3 7 whatsnew37-asyncio-perf1428521
Ref: cfb1428521
Ref: Optimizations<7>-Footnote-11433103
Ref: Optimizations<7>-Footnote-21433168
Ref: Optimizations<7>-Footnote-31433233
Ref: Optimizations<7>-Footnote-41433298
Ref: Optimizations<7>-Footnote-51433363
Ref: Optimizations<7>-Footnote-61433428
Ref: Optimizations<7>-Footnote-71433493
Ref: Optimizations<7>-Footnote-81433558
Ref: Optimizations<7>-Footnote-91433623
Ref: Optimizations<7>-Footnote-101433688
Ref: Optimizations<7>-Footnote-111433754
Ref: Optimizations<7>-Footnote-121433820
Ref: Optimizations<7>-Footnote-131433886
Ref: Optimizations<7>-Footnote-141433952
Ref: Optimizations<7>-Footnote-151434018
Ref: Optimizations<7>-Footnote-161434084
Ref: Optimizations<7>-Footnote-171434150
Ref: Optimizations<7>-Footnote-181434216
Ref: Optimizations<7>-Footnote-191434282
Ref: Optimizations<7>-Footnote-201434348
Ref: Optimizations<7>-Footnote-211434414
Ref: Optimizations<7>-Footnote-221434480
Ref: Optimizations<7>-Footnote-231434546
Ref: Optimizations<7>-Footnote-241434612
Ref: Optimizations<7>-Footnote-251434678
Ref: Optimizations<7>-Footnote-261434744
Ref: Optimizations<7>-Footnote-271434810
Ref: Optimizations<7>-Footnote-281434876
Ref: Optimizations<7>-Footnote-291434942
Ref: Optimizations<7>-Footnote-301435008
Node: Other CPython Implementation Changes<2>1435074
Ref: whatsnew/3 7 other-cpython-implementation-changes1435236
Ref: dd71435236
Ref: Other CPython Implementation Changes<2>-Footnote-11436643
Ref: Other CPython Implementation Changes<2>-Footnote-21436708
Ref: Other CPython Implementation Changes<2>-Footnote-31436773
Ref: Other CPython Implementation Changes<2>-Footnote-41436838
Ref: Other CPython Implementation Changes<2>-Footnote-51436903
Node: Deprecated Python Behavior1436968
Ref: whatsnew/3 7 deprecated-python-behavior1437161
Ref: dda1437161
Ref: Deprecated Python Behavior-Footnote-11438270
Ref: Deprecated Python Behavior-Footnote-21438335
Node: Deprecated Python modules functions and methods1438400
Ref: whatsnew/3 7 deprecated-python-modules-functions-and-methods1438597
Ref: ddc1438597
Node: aifc1438996
Ref: whatsnew/3 7 aifc1439104
Ref: ddd1439104
Ref: aifc-Footnote-11439324
Node: asyncio<11>1439389
Ref: whatsnew/3 7 id21439520
Ref: dde1439520
Ref: whatsnew/3 7 whatsnew37-asyncio-deprecated1439520
Ref: d161439520
Ref: asyncio<11>-Footnote-11440045
Ref: asyncio<11>-Footnote-21440110
Node: collections<3>1440175
Ref: whatsnew/3 7 id31440308
Ref: ddf1440308
Ref: collections<3>-Footnote-11440687
Node: dbm<3>1440752
Ref: whatsnew/3 7 id41440881
Ref: de01440881
Ref: dbm<3>-Footnote-11441282
Node: enum<6>1441347
Ref: whatsnew/3 7 id51441472
Ref: de11441472
Ref: enum<6>-Footnote-11441933
Node: gettext<2>1441998
Ref: whatsnew/3 7 gettext1442129
Ref: de21442129
Ref: gettext<2>-Footnote-11442374
Node: importlib<5>1442439
Ref: whatsnew/3 7 id61442572
Ref: de31442572
Ref: importlib<5>-Footnote-11443082
Node: locale<5>1443147
Ref: whatsnew/3 7 id71443277
Ref: de51443277
Ref: locale<5>-Footnote-11443480
Node: macpath1443545
Ref: whatsnew/3 7 macpath1443675
Ref: de61443675
Ref: macpath-Footnote-11443865
Node: threading<6>1443929
Ref: whatsnew/3 7 threading1444059
Ref: de71444059
Ref: threading<6>-Footnote-11444357
Node: socket<7>1444422
Ref: whatsnew/3 7 id81444551
Ref: de81444551
Ref: socket<7>-Footnote-11444896
Node: ssl<7>1444961
Ref: whatsnew/3 7 id91445083
Ref: de91445083
Ref: ssl<7>-Footnote-11445295
Node: sunau1445360
Ref: whatsnew/3 7 sunau1445479
Ref: dea1445479
Ref: sunau-Footnote-11445705
Node: sys<9>1445770
Ref: whatsnew/3 7 id101445887
Ref: deb1445887
Ref: sys<9>-Footnote-11446204
Node: wave1446269
Ref: whatsnew/3 7 wave1446372
Ref: dec1446372
Ref: wave-Footnote-11446600
Node: Deprecated functions and types of the C API1446665
Ref: whatsnew/3 7 deprecated-functions-and-types-of-the-c-api1446861
Ref: ded1446861
Ref: Deprecated functions and types of the C API-Footnote-11447519
Ref: Deprecated functions and types of the C API-Footnote-21447584
Node: Platform Support Removals1447649
Ref: whatsnew/3 7 id111447825
Ref: dee1447825
Ref: whatsnew/3 7 platform-support-removals1447825
Ref: d791447825
Ref: Platform Support Removals-Footnote-11449229
Ref: Platform Support Removals-Footnote-21449296
Node: API and Feature Removals<2>1449376
Ref: whatsnew/3 7 api-and-feature-removals1449524
Ref: def1449524
Ref: API and Feature Removals<2>-Footnote-11452431
Ref: API and Feature Removals<2>-Footnote-21452496
Ref: API and Feature Removals<2>-Footnote-31452561
Node: Module Removals1452626
Ref: whatsnew/3 7 module-removals1452769
Ref: df31452769
Ref: Module Removals-Footnote-11453104
Node: Windows-only Changes1453169
Ref: whatsnew/3 7 windows-only-changes1453306
Ref: df41453306
Ref: Windows-only Changes-Footnote-11454183
Ref: Windows-only Changes-Footnote-21454248
Node: Porting to Python 3 71454313
Ref: whatsnew/3 7 porting-to-python-3-71454466
Ref: df51454466
Ref: whatsnew/3 7 porting-to-python-371454466
Ref: cca1454466
Node: Changes in Python Behavior1454928
Ref: whatsnew/3 7 changes-in-python-behavior1455049
Ref: df61455049
Ref: Changes in Python Behavior-Footnote-11456915
Ref: Changes in Python Behavior-Footnote-21456980
Ref: Changes in Python Behavior-Footnote-31457022
Ref: Changes in Python Behavior-Footnote-41457087
Ref: Changes in Python Behavior-Footnote-51457152
Ref: Changes in Python Behavior-Footnote-61457217
Node: Changes in the Python API<7>1457282
Ref: whatsnew/3 7 changes-in-the-python-api1457435
Ref: df91457435
Ref: Changes in the Python API<7>-Footnote-11467004
Ref: Changes in the Python API<7>-Footnote-21467069
Ref: Changes in the Python API<7>-Footnote-31467134
Ref: Changes in the Python API<7>-Footnote-41467199
Ref: Changes in the Python API<7>-Footnote-51467264
Ref: Changes in the Python API<7>-Footnote-61467329
Ref: Changes in the Python API<7>-Footnote-71467394
Ref: Changes in the Python API<7>-Footnote-81467459
Ref: Changes in the Python API<7>-Footnote-91467524
Ref: Changes in the Python API<7>-Footnote-101467589
Ref: Changes in the Python API<7>-Footnote-111467655
Ref: Changes in the Python API<7>-Footnote-121467721
Ref: Changes in the Python API<7>-Footnote-131467787
Ref: Changes in the Python API<7>-Footnote-141467853
Ref: Changes in the Python API<7>-Footnote-151467896
Ref: Changes in the Python API<7>-Footnote-161467962
Ref: Changes in the Python API<7>-Footnote-171468028
Ref: Changes in the Python API<7>-Footnote-181468094
Ref: Changes in the Python API<7>-Footnote-191468160
Ref: Changes in the Python API<7>-Footnote-201468226
Ref: Changes in the Python API<7>-Footnote-211468292
Ref: Changes in the Python API<7>-Footnote-221468358
Ref: Changes in the Python API<7>-Footnote-231468424
Ref: Changes in the Python API<7>-Footnote-241468490
Ref: Changes in the Python API<7>-Footnote-251468556
Ref: Changes in the Python API<7>-Footnote-261468622
Ref: Changes in the Python API<7>-Footnote-271468688
Ref: Changes in the Python API<7>-Footnote-281468754
Ref: Changes in the Python API<7>-Footnote-291468820
Ref: Changes in the Python API<7>-Footnote-301468886
Node: Changes in the C API<6>1468952
Ref: whatsnew/3 7 changes-in-the-c-api1469106
Ref: e191469106
Ref: Changes in the C API<6>-Footnote-11469742
Node: CPython bytecode changes<6>1469807
Ref: whatsnew/3 7 cpython-bytecode-changes1469956
Ref: e1a1469956
Ref: CPython bytecode changes<6>-Footnote-11470296
Ref: CPython bytecode changes<6>-Footnote-21470361
Node: Windows-only Changes<2>1470426
Ref: whatsnew/3 7 id121470588
Ref: e1b1470588
Ref: Windows-only Changes<2>-Footnote-11470909
Node: Other CPython implementation changes1470974
Ref: whatsnew/3 7 id131471100
Ref: e1d1471100
Ref: Other CPython implementation changes-Footnote-11473430
Ref: Other CPython implementation changes-Footnote-21473472
Ref: Other CPython implementation changes-Footnote-31473537
Node: Notable changes in Python 3 7 11473602
Ref: whatsnew/3 7 notable-changes-in-python-3-7-11473766
Ref: e1f1473766
Ref: Notable changes in Python 3 7 1-Footnote-11474706
Ref: Notable changes in Python 3 7 1-Footnote-21474771
Ref: Notable changes in Python 3 7 1-Footnote-31474836
Node: Notable changes in Python 3 7 21474901
Ref: whatsnew/3 7 notable-changes-in-python-3-7-21475075
Ref: e221475075
Node: Notable changes in Python 3 7 61475570
Ref: whatsnew/3 7 notable-changes-in-python-3-7-61475745
Ref: e231475745
Ref: Notable changes in Python 3 7 6-Footnote-11476256
Node: Notable changes in Python 3 7 101476321
Ref: whatsnew/3 7 notable-changes-in-python-3-7-101476497
Ref: e241476497
Ref: Notable changes in Python 3 7 10-Footnote-11477217
Node: Notable changes in Python 3 7 111477282
Ref: whatsnew/3 7 notable-changes-in-python-3-7-111477461
Ref: e251477461
Ref: Notable changes in Python 3 7 11-Footnote-11478378
Ref: Notable changes in Python 3 7 11-Footnote-21478433
Node: Notable security feature in 3 7 141478488
Ref: whatsnew/3 7 notable-security-feature-in-3-7-141478626
Ref: e261478626
Ref: Notable security feature in 3 7 14-Footnote-11479356
Node: What’s New In Python 3 61479412
Ref: whatsnew/3 6 doc1479562
Ref: e271479562
Ref: whatsnew/3 6 translation-repo1479562
Ref: e281479562
Ref: whatsnew/3 6 what-s-new-in-python-3-61479562
Ref: e291479562
Ref: What’s New In Python 3 6-Footnote-11480909
Ref: What’s New In Python 3 6-Footnote-21480969
Node: Summary – Release highlights<6>1481011
Ref: whatsnew/3 6 summary-release-highlights1481132
Ref: e2a1481132
Ref: Summary – Release highlights<6>-Footnote-11485371
Ref: Summary – Release highlights<6>-Footnote-21485451
Ref: Summary – Release highlights<6>-Footnote-31485541
Node: New Features<11>1485583
Ref: whatsnew/3 6 new-features1485738
Ref: e3e1485738
Ref: whatsnew/3 6 pypy-dict-implementation1485738
Ref: e3f1485738
Node: PEP 498 Formatted string literals1487148
Ref: whatsnew/3 6 pep-498-formatted-string-literals1487282
Ref: e401487282
Ref: whatsnew/3 6 whatsnew36-pep4981487282
Ref: e2b1487282
Ref: PEP 498 Formatted string literals-Footnote-11488270
Ref: PEP 498 Formatted string literals-Footnote-21488312
Node: PEP 526 Syntax for variable annotations1488354
Ref: whatsnew/3 6 pep-526-syntax-for-variable-annotations1488536
Ref: e411488536
Ref: whatsnew/3 6 whatsnew36-pep5261488536
Ref: e2d1488536
Ref: PEP 526 Syntax for variable annotations-Footnote-11489784
Ref: PEP 526 Syntax for variable annotations-Footnote-21489826
Ref: PEP 526 Syntax for variable annotations-Footnote-31489868
Ref: PEP 526 Syntax for variable annotations-Footnote-41489903
Node: PEP 515 Underscores in Numeric Literals1489944
Ref: whatsnew/3 6 pep-515-underscores-in-numeric-literals1490124
Ref: e421490124
Ref: whatsnew/3 6 whatsnew36-pep5151490124
Ref: e2c1490124
Ref: PEP 515 Underscores in Numeric Literals-Footnote-11491197
Ref: PEP 515 Underscores in Numeric Literals-Footnote-21491239
Node: PEP 525 Asynchronous Generators1491281
Ref: whatsnew/3 6 pep-525-asynchronous-generators1491457
Ref: e431491457
Ref: whatsnew/3 6 whatsnew36-pep5251491457
Ref: e2e1491457
Ref: PEP 525 Asynchronous Generators-Footnote-11492296
Ref: PEP 525 Asynchronous Generators-Footnote-21492338
Node: PEP 530 Asynchronous Comprehensions1492380
Ref: whatsnew/3 6 pep-530-asynchronous-comprehensions1492564
Ref: e441492564
Ref: whatsnew/3 6 whatsnew36-pep5301492564
Ref: e2f1492564
Ref: PEP 530 Asynchronous Comprehensions-Footnote-11493126
Ref: PEP 530 Asynchronous Comprehensions-Footnote-21493168
Node: PEP 487 Simpler customization of class creation1493210
Ref: whatsnew/3 6 pep-487-simpler-customization-of-class-creation1493403
Ref: e451493403
Ref: whatsnew/3 6 whatsnew36-pep4871493403
Ref: e321493403
Ref: PEP 487 Simpler customization of class creation-Footnote-11494499
Node: PEP 487 Descriptor Protocol Enhancements1494541
Ref: whatsnew/3 6 pep-487-descriptor-protocol-enhancements1494741
Ref: e481494741
Ref: whatsnew/3 6 whatsnew36-pep487-descriptors1494741
Ref: e491494741
Ref: PEP 487 Descriptor Protocol Enhancements-Footnote-11495996
Ref: PEP 487 Descriptor Protocol Enhancements-Footnote-21496038
Node: PEP 519 Adding a file system path protocol1496080
Ref: whatsnew/3 6 pep-519-adding-a-file-system-path-protocol1496266
Ref: e4c1496266
Ref: whatsnew/3 6 whatsnew36-pep5191496266
Ref: e371496266
Ref: PEP 519 Adding a file system path protocol-Footnote-11499097
Node: PEP 495 Local Time Disambiguation1499139
Ref: whatsnew/3 6 pep-495-local-time-disambiguation1499336
Ref: e521499336
Ref: whatsnew/3 6 whatsnew36-pep4951499336
Ref: e381499336
Ref: PEP 495 Local Time Disambiguation-Footnote-11500753
Ref: PEP 495 Local Time Disambiguation-Footnote-21500795
Node: PEP 529 Change Windows filesystem encoding to UTF-81500837
Ref: whatsnew/3 6 pep-529-change-windows-filesystem-encoding-to-utf-81501040
Ref: e541501040
Ref: whatsnew/3 6 whatsnew36-pep5291501040
Ref: e3c1501040
Ref: PEP 529 Change Windows filesystem encoding to UTF-8-Footnote-11502070
Node: PEP 528 Change Windows console encoding to UTF-81502112
Ref: whatsnew/3 6 pep-528-change-windows-console-encoding-to-utf-81502333
Ref: e561502333
Ref: whatsnew/3 6 whatsnew36-pep5281502333
Ref: e3b1502333
Ref: PEP 528 Change Windows console encoding to UTF-8-Footnote-11503040
Node: PEP 520 Preserving Class Attribute Definition Order1503082
Ref: whatsnew/3 6 pep-520-preserving-class-attribute-definition-order1503293
Ref: e581503293
Ref: whatsnew/3 6 whatsnew36-pep5201503293
Ref: e331503293
Ref: PEP 520 Preserving Class Attribute Definition Order-Footnote-11503937
Node: PEP 468 Preserving Keyword Argument Order1503979
Ref: whatsnew/3 6 pep-468-preserving-keyword-argument-order1504165
Ref: e5b1504165
Ref: whatsnew/3 6 whatsnew36-pep4681504165
Ref: e341504165
Ref: PEP 468 Preserving Keyword Argument Order-Footnote-11504530
Node: New dict implementation1504572
Ref: whatsnew/3 6 new-dict-implementation1504755
Ref: e5c1504755
Ref: whatsnew/3 6 whatsnew36-compactdict1504755
Ref: e311504755
Ref: New dict implementation-Footnote-11505731
Ref: New dict implementation-Footnote-21505811
Ref: New dict implementation-Footnote-31505901
Ref: New dict implementation-Footnote-41505966
Node: PEP 523 Adding a frame evaluation API to CPython1506046
Ref: whatsnew/3 6 pep-523-adding-a-frame-evaluation-api-to-cpython1506221
Ref: e5d1506221
Ref: whatsnew/3 6 whatsnew36-pep5231506221
Ref: e5e1506221
Ref: PEP 523 Adding a frame evaluation API to CPython-Footnote-11507396
Ref: PEP 523 Adding a frame evaluation API to CPython-Footnote-21507438
Node: PYTHONMALLOC environment variable1507480
Ref: whatsnew/3 6 pythonmalloc-environment-variable1507668
Ref: e5f1507668
Ref: whatsnew/3 6 whatsnew36-pythonmalloc1507668
Ref: e361507668
Ref: PYTHONMALLOC environment variable-Footnote-11510851
Ref: PYTHONMALLOC environment variable-Footnote-21510916
Node: DTrace and SystemTap probing support1510981
Ref: whatsnew/3 6 dtrace-and-systemtap-probing-support1511112
Ref: e671511112
Ref: whatsnew/3 6 whatsnew36-tracing1511112
Ref: e351511112
Ref: DTrace and SystemTap probing support-Footnote-11511955
Node: Other Language Changes<7>1512020
Ref: whatsnew/3 6 other-language-changes1512156
Ref: e691512156
Ref: Other Language Changes<7>-Footnote-11513541
Ref: Other Language Changes<7>-Footnote-21513606
Ref: Other Language Changes<7>-Footnote-31513671
Ref: Other Language Changes<7>-Footnote-41513736
Node: New Modules<7>1513801
Ref: whatsnew/3 6 new-modules1513940
Ref: e6d1513940
Node: secrets1513999
Ref: whatsnew/3 6 secrets1514057
Ref: e6e1514057
Ref: whatsnew/3 6 whatsnew36-pep5061514057
Ref: e301514057
Ref: secrets-Footnote-11514749
Node: Improved Modules<7>1514791
Ref: whatsnew/3 6 improved-modules1514921
Ref: e6f1514921
Node: array<4>1516434
Ref: whatsnew/3 6 array1516513
Ref: e701516513
Ref: array<4>-Footnote-11516806
Node: ast<6>1516871
Ref: whatsnew/3 6 ast1516970
Ref: e711516970
Ref: ast<6>-Footnote-11517219
Node: asyncio<12>1517284
Ref: whatsnew/3 6 asyncio1517386
Ref: e721517386
Ref: asyncio<12>-Footnote-11520733
Ref: asyncio<12>-Footnote-21520798
Ref: asyncio<12>-Footnote-31520843
Ref: asyncio<12>-Footnote-41520908
Ref: asyncio<12>-Footnote-51520973
Ref: asyncio<12>-Footnote-61521038
Ref: asyncio<12>-Footnote-71521103
Ref: asyncio<12>-Footnote-81521168
Ref: asyncio<12>-Footnote-91521233
Ref: asyncio<12>-Footnote-101521298
Ref: asyncio<12>-Footnote-111521364
Ref: asyncio<12>-Footnote-121521430
Node: binascii<2>1521496
Ref: whatsnew/3 6 binascii1521597
Ref: e7c1521597
Ref: binascii<2>-Footnote-11521882
Node: cmath1521947
Ref: whatsnew/3 6 cmath1522051
Ref: e7e1522051
Ref: cmath-Footnote-11522522
Ref: cmath-Footnote-21522587
Ref: cmath-Footnote-31522629
Node: collections<4>1522694
Ref: whatsnew/3 6 collections1522808
Ref: e851522808
Ref: collections<4>-Footnote-11523914
Ref: collections<4>-Footnote-21523979
Ref: collections<4>-Footnote-31524044
Ref: collections<4>-Footnote-41524109
Ref: collections<4>-Footnote-51524174
Ref: collections<4>-Footnote-61524239
Node: concurrent futures<5>1524304
Ref: whatsnew/3 6 concurrent-futures1524426
Ref: e8a1524426
Ref: concurrent futures<5>-Footnote-11524757
Node: contextlib<4>1524822
Ref: whatsnew/3 6 contextlib1524941
Ref: e8b1524941
Ref: contextlib<4>-Footnote-11525437
Node: datetime<6>1525502
Ref: whatsnew/3 6 datetime1525610
Ref: e8e1525610
Ref: datetime<6>-Footnote-11526632
Ref: datetime<6>-Footnote-21526697
Ref: datetime<6>-Footnote-31526762
Ref: datetime<6>-Footnote-41526827
Node: decimal<3>1526892
Ref: whatsnew/3 6 decimal1526999
Ref: e931526999
Ref: decimal<3>-Footnote-11527412
Node: distutils<5>1527477
Ref: whatsnew/3 6 distutils1527581
Ref: e951527581
Ref: distutils<5>-Footnote-11527955
Node: email<3>1528020
Ref: whatsnew/3 6 email1528126
Ref: e961528126
Ref: email<3>-Footnote-11529042
Ref: email<3>-Footnote-21529107
Ref: email<3>-Footnote-31529172
Node: encodings<2>1529237
Ref: whatsnew/3 6 encodings1529338
Ref: e9a1529338
Ref: encodings<2>-Footnote-11529633
Node: enum<7>1529698
Ref: whatsnew/3 6 enum1529806
Ref: e9b1529806
Ref: enum<7>-Footnote-11530563
Node: faulthandler<3>1530628
Ref: whatsnew/3 6 faulthandler1530736
Ref: e9e1530736
Ref: faulthandler<3>-Footnote-11530999
Node: fileinput<2>1531064
Ref: whatsnew/3 6 fileinput1531175
Ref: e9f1531175
Ref: fileinput<2>-Footnote-11531363
Node: hashlib<5>1531428
Ref: whatsnew/3 6 hashlib1531538
Ref: ea11531538
Ref: hashlib<5>-Footnote-11532587
Ref: hashlib<5>-Footnote-21532652
Ref: hashlib<5>-Footnote-31532717
Ref: hashlib<5>-Footnote-41532782
Node: http client<2>1532847
Ref: whatsnew/3 6 http-client1532964
Ref: ea81532964
Ref: http client<2>-Footnote-11533224
Node: idlelib and IDLE<2>1533289
Ref: whatsnew/3 6 idlelib-and-idle1533408
Ref: eab1533408
Ref: idlelib and IDLE<2>-Footnote-11536882
Ref: idlelib and IDLE<2>-Footnote-21536947
Ref: idlelib and IDLE<2>-Footnote-31537012
Ref: idlelib and IDLE<2>-Footnote-41537079
Ref: idlelib and IDLE<2>-Footnote-51537144
Ref: idlelib and IDLE<2>-Footnote-61537209
Ref: idlelib and IDLE<2>-Footnote-71537274
Ref: idlelib and IDLE<2>-Footnote-81537339
Ref: idlelib and IDLE<2>-Footnote-91537404
Ref: idlelib and IDLE<2>-Footnote-101537469
Ref: idlelib and IDLE<2>-Footnote-111537535
Node: importlib<6>1537603
Ref: whatsnew/3 6 importlib1537718
Ref: eac1537718
Ref: importlib<6>-Footnote-11538545
Node: inspect<7>1538610
Ref: whatsnew/3 6 inspect1538713
Ref: eb21538713
Ref: inspect<7>-Footnote-11539488
Ref: inspect<7>-Footnote-21539553
Node: json<2>1539618
Ref: whatsnew/3 6 json1539719
Ref: eb31539719
Ref: json<2>-Footnote-11539991
Node: logging<4>1540056
Ref: whatsnew/3 6 logging1540154
Ref: eb51540154
Ref: logging<4>-Footnote-11540418
Node: math<7>1540483
Ref: whatsnew/3 6 math1540592
Ref: eb71540592
Ref: math<7>-Footnote-11540824
Ref: math<7>-Footnote-21540889
Node: multiprocessing<6>1540931
Ref: whatsnew/3 6 multiprocessing1541035
Ref: eb81541035
Ref: multiprocessing<6>-Footnote-11541264
Node: os<9>1541328
Ref: whatsnew/3 6 os1541436
Ref: eb91541436
Ref: os<9>-Footnote-11542436
Ref: os<9>-Footnote-21542501
Ref: os<9>-Footnote-31542543
Node: pathlib<12>1542585
Ref: whatsnew/3 6 pathlib1542681
Ref: ebc1542681
Ref: pathlib<12>-Footnote-11542915
Node: pdb<7>1542980
Ref: whatsnew/3 6 pdb1543080
Ref: ebd1543080
Node: pickle<3>1543237
Ref: whatsnew/3 6 pickle1543337
Ref: ebe1543337
Ref: pickle<3>-Footnote-11543654
Node: pickletools1543719
Ref: whatsnew/3 6 pickletools1543821
Ref: ebf1543821
Ref: pickletools-Footnote-11544049
Node: pydoc<4>1544114
Ref: whatsnew/3 6 pydoc1544216
Ref: ec11544216
Ref: pydoc<4>-Footnote-11544610
Ref: pydoc<4>-Footnote-21544674
Node: random<4>1544739
Ref: whatsnew/3 6 random1544835
Ref: ec21544835
Ref: random<4>-Footnote-11545090
Node: re<6>1545155
Ref: whatsnew/3 6 re1545251
Ref: ec41545251
Ref: re<6>-Footnote-11545962
Ref: re<6>-Footnote-21546028
Ref: re<6>-Footnote-31546093
Node: readline1546158
Ref: whatsnew/3 6 readline1546256
Ref: ec61546256
Ref: readline-Footnote-11546487
Node: rlcompleter1546552
Ref: whatsnew/3 6 rlcompleter1546653
Ref: ec81546653
Ref: rlcompleter-Footnote-11546957
Ref: rlcompleter-Footnote-21547022
Node: shlex<2>1547087
Ref: whatsnew/3 6 shlex1547187
Ref: ec91547187
Ref: shlex<2>-Footnote-11547477
Node: site<3>1547544
Ref: whatsnew/3 6 site1547643
Ref: ecc1547643
Ref: site<3>-Footnote-11547907
Node: sqlite3<8>1547972
Ref: whatsnew/3 6 sqlite31548072
Ref: ecd1548072
Ref: sqlite3<8>-Footnote-11548275
Node: socket<8>1548340
Ref: whatsnew/3 6 socket1548448
Ref: ecf1548448
Ref: socket<8>-Footnote-11549405
Ref: socket<8>-Footnote-21549470
Ref: socket<8>-Footnote-31549535
Ref: socket<8>-Footnote-41549600
Ref: socket<8>-Footnote-51549665
Node: socketserver<2>1549730
Ref: whatsnew/3 6 socketserver1549834
Ref: ed61549834
Ref: socketserver<2>-Footnote-11550469
Ref: socketserver<2>-Footnote-21550534
Node: ssl<8>1550599
Ref: whatsnew/3 6 ssl1550707
Ref: eda1550707
Ref: ssl<8>-Footnote-11552134
Ref: ssl<8>-Footnote-21552199
Ref: ssl<8>-Footnote-31552264
Ref: ssl<8>-Footnote-41552329
Ref: ssl<8>-Footnote-51552394
Ref: ssl<8>-Footnote-61552459
Ref: ssl<8>-Footnote-71552524
Ref: ssl<8>-Footnote-81552589
Node: statistics<4>1552644
Ref: whatsnew/3 6 statistics1552746
Ref: ede1552746
Ref: statistics<4>-Footnote-11552936
Node: struct<2>1553001
Ref: whatsnew/3 6 struct1553110
Ref: ee01553110
Ref: struct<2>-Footnote-11553341
Node: subprocess<3>1553406
Ref: whatsnew/3 6 subprocess1553509
Ref: ee11553509
Ref: subprocess<3>-Footnote-11554202
Ref: subprocess<3>-Footnote-21554267
Node: sys<10>1554331
Ref: whatsnew/3 6 sys1554434
Ref: ee31554434
Ref: sys<10>-Footnote-11555035
Ref: sys<10>-Footnote-21555100
Node: telnetlib1555165
Ref: whatsnew/3 6 telnetlib1555262
Ref: ee61555262
Ref: telnetlib-Footnote-11555437
Node: time<6>1555502
Ref: whatsnew/3 6 time1555598
Ref: ee71555598
Node: timeit1555737
Ref: whatsnew/3 6 timeit1555834
Ref: ee91555834
Ref: timeit-Footnote-11556293
Ref: timeit-Footnote-21556357
Node: tkinter<7>1556422
Ref: whatsnew/3 6 tkinter1556524
Ref: eec1556524
Ref: tkinter<7>-Footnote-11556968
Node: traceback<4>1557033
Ref: whatsnew/3 6 traceback1557143
Ref: eed1557143
Ref: whatsnew/3 6 whatsnew36-traceback1557143
Ref: e6c1557143
Ref: traceback<4>-Footnote-11557778
Node: tracemalloc<3>1557843
Ref: whatsnew/3 6 tracemalloc1557953
Ref: eee1557953
Ref: tracemalloc<3>-Footnote-11558314
Node: typing<10>1558379
Ref: whatsnew/3 6 typing1558491
Ref: ef01558491
Ref: whatsnew/3 6 whatsnew36-typing1558491
Ref: e391558491
Ref: typing<10>-Footnote-11560143
Ref: typing<10>-Footnote-21560193
Ref: typing<10>-Footnote-31560258
Ref: typing<10>-Footnote-41560323
Ref: typing<10>-Footnote-51560365
Ref: typing<10>-Footnote-61560415
Ref: typing<10>-Footnote-71560467
Node: unicodedata<8>1560519
Ref: whatsnew/3 6 unicodedata1560633
Ref: ef41560633
Ref: unicodedata<8>-Footnote-11560821
Node: unittest mock<2>1560872
Ref: whatsnew/3 6 unittest-mock1560990
Ref: ef51560990
Ref: unittest mock<2>-Footnote-11561507
Ref: unittest mock<2>-Footnote-21561572
Node: urllib request1561637
Ref: whatsnew/3 6 urllib-request1561759
Ref: ef91561759
Ref: urllib request-Footnote-11562131
Node: urllib robotparser1562196
Ref: whatsnew/3 6 urllib-robotparser1562309
Ref: efb1562309
Ref: urllib robotparser-Footnote-11562554
Node: venv<5>1562619
Ref: whatsnew/3 6 venv1562729
Ref: efd1562729
Ref: venv<5>-Footnote-11563016
Node: warnings<4>1563081
Ref: whatsnew/3 6 warnings1563179
Ref: efe1563179
Ref: warnings<4>-Footnote-11564452
Ref: warnings<4>-Footnote-21564517
Node: winreg1564582
Ref: whatsnew/3 6 winreg1564681
Ref: f001564681
Ref: winreg-Footnote-11564854
Node: winsound1564919
Ref: whatsnew/3 6 winsound1565020
Ref: f021565020
Ref: winsound-Footnote-11565219
Node: xmlrpc client1565284
Ref: whatsnew/3 6 xmlrpc-client1565389
Ref: f061565389
Ref: xmlrpc client-Footnote-11565682
Node: zipfile<4>1565747
Ref: whatsnew/3 6 zipfile1565851
Ref: f071565851
Ref: zipfile<4>-Footnote-11566385
Ref: zipfile<4>-Footnote-21566450
Node: zlib<2>1566515
Ref: whatsnew/3 6 zlib1566597
Ref: f0a1566597
Ref: zlib<2>-Footnote-11566853
Ref: zlib<2>-Footnote-21566918
Node: Optimizations<8>1566983
Ref: whatsnew/3 6 optimizations1567125
Ref: f0c1567125
Ref: Optimizations<8>-Footnote-11570994
Ref: Optimizations<8>-Footnote-21571059
Ref: Optimizations<8>-Footnote-31571124
Ref: Optimizations<8>-Footnote-41571189
Ref: Optimizations<8>-Footnote-51571254
Ref: Optimizations<8>-Footnote-61571319
Ref: Optimizations<8>-Footnote-71571384
Ref: Optimizations<8>-Footnote-81571449
Ref: Optimizations<8>-Footnote-91571514
Ref: Optimizations<8>-Footnote-101571579
Ref: Optimizations<8>-Footnote-111571645
Ref: Optimizations<8>-Footnote-121571711
Ref: Optimizations<8>-Footnote-131571777
Ref: Optimizations<8>-Footnote-141571843
Ref: Optimizations<8>-Footnote-151571909
Ref: Optimizations<8>-Footnote-161571975
Ref: Optimizations<8>-Footnote-171572041
Ref: Optimizations<8>-Footnote-181572107
Ref: Optimizations<8>-Footnote-191572173
Ref: Optimizations<8>-Footnote-201572239
Ref: Optimizations<8>-Footnote-211572305
Node: Build and C API Changes<2>1572371
Ref: whatsnew/3 6 build-and-c-api-changes1572512
Ref: f121572512
Ref: Build and C API Changes<2>-Footnote-11574965
Ref: Build and C API Changes<2>-Footnote-21575007
Ref: Build and C API Changes<2>-Footnote-31575072
Ref: Build and C API Changes<2>-Footnote-41575137
Ref: Build and C API Changes<2>-Footnote-51575202
Ref: Build and C API Changes<2>-Footnote-61575266
Ref: Build and C API Changes<2>-Footnote-71575331
Ref: Build and C API Changes<2>-Footnote-81575396
Ref: Build and C API Changes<2>-Footnote-91575461
Ref: Build and C API Changes<2>-Footnote-101575526
Node: Other Improvements1575592
Ref: whatsnew/3 6 other-improvements1575730
Ref: f181575730
Node: Deprecated<8>1576099
Ref: whatsnew/3 6 deprecated1576221
Ref: f1a1576221
Node: New Keywords1576557
Ref: whatsnew/3 6 new-keywords1576654
Ref: f1b1576654
Ref: New Keywords-Footnote-11577047
Node: Deprecated Python behavior1577089
Ref: whatsnew/3 6 deprecated-python-behavior1577245
Ref: f1c1577245
Ref: Deprecated Python behavior-Footnote-11578452
Ref: Deprecated Python behavior-Footnote-21578517
Ref: Deprecated Python behavior-Footnote-31578582
Node: Deprecated Python modules functions and methods<2>1578647
Ref: whatsnew/3 6 deprecated-python-modules-functions-and-methods1578797
Ref: f1e1578797
Node: asynchat1579107
Ref: whatsnew/3 6 asynchat1579219
Ref: f1f1579219
Ref: asynchat-Footnote-11579403
Node: asyncore1579468
Ref: whatsnew/3 6 asyncore1579595
Ref: f201579595
Ref: asyncore-Footnote-11579779
Node: dbm<4>1579844
Ref: whatsnew/3 6 dbm1579975
Ref: f211579975
Ref: dbm<4>-Footnote-11580335
Node: distutils<6>1580400
Ref: whatsnew/3 6 id21580526
Ref: f221580526
Ref: distutils<6>-Footnote-11580856
Node: grp1580921
Ref: whatsnew/3 6 grp1581053
Ref: f231581053
Ref: grp-Footnote-11581251
Node: importlib<7>1581316
Ref: whatsnew/3 6 id31581442
Ref: f251581442
Node: os<10>1582096
Ref: whatsnew/3 6 id41582224
Ref: f2a1582224
Ref: os<10>-Footnote-11582518
Ref: os<10>-Footnote-21582583
Node: re<7>1582648
Ref: whatsnew/3 6 id51582770
Ref: f2b1582770
Ref: re<7>-Footnote-11583096
Node: ssl<9>1583161
Ref: whatsnew/3 6 id61583287
Ref: f2c1583287
Ref: ssl<9>-Footnote-11584082
Ref: ssl<9>-Footnote-21584147
Ref: ssl<9>-Footnote-31584212
Node: tkinter<8>1584277
Ref: whatsnew/3 6 id71584405
Ref: f2d1584405
Node: venv<6>1584558
Ref: whatsnew/3 6 id81584671
Ref: f2e1584671
Ref: whatsnew/3 6 whatsnew36-venv1584671
Ref: f2f1584671
Ref: venv<6>-Footnote-11585022
Node: xml<6>1585087
Ref: whatsnew/3 6 xml1585257
Ref: f301585257
Ref: xml<6>-Footnote-11585561
Node: Deprecated functions and types of the C API<2>1585616
Ref: whatsnew/3 6 deprecated-functions-and-types-of-the-c-api1585760
Ref: f311585760
Node: Deprecated Build Options1586109
Ref: whatsnew/3 6 deprecated-build-options1586238
Ref: f331586238
Node: Removed<8>1586679
Ref: whatsnew/3 6 removed1586804
Ref: f341586804
Node: API and Feature Removals<3>1586902
Ref: whatsnew/3 6 api-and-feature-removals1586976
Ref: f351586976
Ref: API and Feature Removals<3>-Footnote-11589067
Ref: API and Feature Removals<3>-Footnote-21589132
Node: Porting to Python 3 61589210
Ref: whatsnew/3 6 porting-to-python-3-61589353
Ref: f381589353
Node: Changes in “python” Command Behavior1589739
Ref: whatsnew/3 6 changes-in-python-command-behavior1589874
Ref: f391589874
Ref: Changes in “python” Command Behavior-Footnote-11590354
Node: Changes in the Python API<8>1590419
Ref: whatsnew/3 6 changes-in-the-python-api1590586
Ref: f3a1590586
Ref: Changes in the Python API<8>-Footnote-11600701
Ref: Changes in the Python API<8>-Footnote-21600765
Ref: Changes in the Python API<8>-Footnote-31600807
Ref: Changes in the Python API<8>-Footnote-41600872
Ref: Changes in the Python API<8>-Footnote-51600937
Ref: Changes in the Python API<8>-Footnote-61601002
Ref: Changes in the Python API<8>-Footnote-71601067
Ref: Changes in the Python API<8>-Footnote-81601132
Ref: Changes in the Python API<8>-Footnote-91601197
Ref: Changes in the Python API<8>-Footnote-101601262
Ref: Changes in the Python API<8>-Footnote-111601328
Ref: Changes in the Python API<8>-Footnote-121601371
Ref: Changes in the Python API<8>-Footnote-131601437
Ref: Changes in the Python API<8>-Footnote-141601503
Ref: Changes in the Python API<8>-Footnote-151601569
Ref: Changes in the Python API<8>-Footnote-161601635
Ref: Changes in the Python API<8>-Footnote-171601700
Ref: Changes in the Python API<8>-Footnote-181601766
Ref: Changes in the Python API<8>-Footnote-191601832
Ref: Changes in the Python API<8>-Footnote-201601898
Node: Changes in the C API<7>1601964
Ref: whatsnew/3 6 changes-in-the-c-api1602118
Ref: f4c1602118
Ref: Changes in the C API<7>-Footnote-11602772
Ref: Changes in the C API<7>-Footnote-21602837
Node: CPython bytecode changes<7>1602901
Ref: whatsnew/3 6 cpython-bytecode-changes1603018
Ref: f4e1603018
Ref: CPython bytecode changes<7>-Footnote-11604638
Ref: CPython bytecode changes<7>-Footnote-21604703
Ref: CPython bytecode changes<7>-Footnote-31604768
Ref: CPython bytecode changes<7>-Footnote-41604833
Ref: CPython bytecode changes<7>-Footnote-51604898
Ref: CPython bytecode changes<7>-Footnote-61604963
Ref: CPython bytecode changes<7>-Footnote-71605028
Ref: CPython bytecode changes<7>-Footnote-81605093
Ref: CPython bytecode changes<7>-Footnote-91605158
Node: Notable changes in Python 3 6 21605223
Ref: whatsnew/3 6 notable-changes-in-python-3-6-21605387
Ref: f541605387
Node: New make regen-all build target1605551
Ref: whatsnew/3 6 new-make-regen-all-build-target1605693
Ref: f551605693
Ref: New make regen-all build target-Footnote-11606482
Ref: New make regen-all build target-Footnote-21606550
Node: Removal of make touch build target1606615
Ref: whatsnew/3 6 removal-of-make-touch-build-target1606757
Ref: f561606757
Ref: Removal of make touch build target-Footnote-11607192
Node: Notable changes in Python 3 6 41607257
Ref: whatsnew/3 6 notable-changes-in-python-3-6-41607431
Ref: f571607431
Ref: Notable changes in Python 3 6 4-Footnote-11607804
Ref: Notable changes in Python 3 6 4-Footnote-21607869
Node: Notable changes in Python 3 6 51607934
Ref: whatsnew/3 6 notable-changes-in-python-3-6-51608108
Ref: f581608108
Ref: Notable changes in Python 3 6 5-Footnote-11608411
Node: Notable changes in Python 3 6 71608476
Ref: whatsnew/3 6 notable-changes-in-python-3-6-71608651
Ref: f591608651
Ref: Notable changes in Python 3 6 7-Footnote-11609160
Ref: Notable changes in Python 3 6 7-Footnote-21609215
Node: Notable changes in Python 3 6 101609280
Ref: whatsnew/3 6 notable-changes-in-python-3-6-101609456
Ref: f5a1609456
Ref: Notable changes in Python 3 6 10-Footnote-11609969
Node: Notable changes in Python 3 6 131610034
Ref: whatsnew/3 6 notable-changes-in-python-3-6-131610211
Ref: f5b1610211
Ref: Notable changes in Python 3 6 13-Footnote-11610931
Node: Notable changes in Python 3 6 141610996
Ref: whatsnew/3 6 notable-changes-in-python-3-6-141611132
Ref: f5c1611132
Ref: Notable changes in Python 3 6 14-Footnote-11612049
Ref: Notable changes in Python 3 6 14-Footnote-21612104
Node: What’s New In Python 3 51612159
Ref: whatsnew/3 5 doc1612309
Ref: f5d1612309
Ref: whatsnew/3 5 translation-repo1612309
Ref: f5e1612309
Ref: whatsnew/3 5 what-s-new-in-python-3-51612309
Ref: f5f1612309
Ref: What’s New In Python 3 5-Footnote-11613253
Ref: What’s New In Python 3 5-Footnote-21613313
Node: Summary – Release highlights<7>1613355
Ref: whatsnew/3 5 summary-release-highlights1613476
Ref: f601613476
Ref: Summary – Release highlights<7>-Footnote-11617207
Ref: Summary – Release highlights<7>-Footnote-21617271
Ref: Summary – Release highlights<7>-Footnote-31617336
Ref: Summary – Release highlights<7>-Footnote-41617401
Ref: Summary – Release highlights<7>-Footnote-51617466
Ref: Summary – Release highlights<7>-Footnote-61617531
Ref: Summary – Release highlights<7>-Footnote-71617596
Node: New Features<12>1617661
Ref: whatsnew/3 5 new-features1617816
Ref: f731617816
Node: PEP 492 - Coroutines with async and await syntax1618914
Ref: whatsnew/3 5 pep-492-coroutines-with-async-and-await-syntax1619086
Ref: f741619086
Ref: whatsnew/3 5 whatsnew-pep-4921619086
Ref: f611619086
Ref: PEP 492 - Coroutines with async and await syntax-Footnote-11622175
Ref: PEP 492 - Coroutines with async and await syntax-Footnote-21622217
Node: PEP 465 - A dedicated infix operator for matrix multiplication1622259
Ref: whatsnew/3 5 pep-465-a-dedicated-infix-operator-for-matrix-multiplication1622486
Ref: f7a1622486
Ref: whatsnew/3 5 whatsnew-pep-4651622486
Ref: f621622486
Ref: PEP 465 - A dedicated infix operator for matrix multiplication-Footnote-11623895
Ref: PEP 465 - A dedicated infix operator for matrix multiplication-Footnote-21623937
Node: PEP 448 - Additional Unpacking Generalizations1623979
Ref: whatsnew/3 5 pep-448-additional-unpacking-generalizations1624218
Ref: f7e1624218
Ref: whatsnew/3 5 whatsnew-pep-4481624218
Ref: f631624218
Ref: PEP 448 - Additional Unpacking Generalizations-Footnote-11625317
Ref: PEP 448 - Additional Unpacking Generalizations-Footnote-21625359
Node: PEP 461 - percent formatting support for bytes and bytearray1625401
Ref: whatsnew/3 5 pep-461-percent-formatting-support-for-bytes-and-bytearray1625598
Ref: f821625598
Ref: whatsnew/3 5 whatsnew-pep-4611625598
Ref: f661625598
Ref: PEP 461 - percent formatting support for bytes and bytearray-Footnote-11627140
Ref: PEP 461 - percent formatting support for bytes and bytearray-Footnote-21627182
Node: PEP 484 - Type Hints1627224
Ref: whatsnew/3 5 pep-484-type-hints1627447
Ref: f841627447
Ref: whatsnew/3 5 whatsnew-pep-4841627447
Ref: f641627447
Ref: PEP 484 - Type Hints-Footnote-11629106
Ref: PEP 484 - Type Hints-Footnote-21629148
Ref: PEP 484 - Type Hints-Footnote-31629190
Ref: PEP 484 - Type Hints-Footnote-41629220
Ref: PEP 484 - Type Hints-Footnote-51629262
Node: PEP 471 - os scandir function – a better and faster directory iterator1629304
Ref: whatsnew/3 5 pep-471-os-scandir-function-a-better-and-faster-directory-iterator1629512
Ref: f851629512
Ref: whatsnew/3 5 whatsnew-pep-4711629512
Ref: f6f1629512
Ref: PEP 471 - os scandir function – a better and faster directory iterator-Footnote-11630874
Ref: PEP 471 - os scandir function – a better and faster directory iterator-Footnote-21630916
Node: PEP 475 Retry system calls failing with EINTR1630958
Ref: whatsnew/3 5 pep-475-retry-system-calls-failing-with-eintr1631201
Ref: f871631201
Ref: whatsnew/3 5 whatsnew-pep-4751631201
Ref: f881631201
Ref: PEP 475 Retry system calls failing with EINTR-Footnote-11634271
Ref: PEP 475 Retry system calls failing with EINTR-Footnote-21634313
Node: PEP 479 Change StopIteration handling inside generators1634355
Ref: whatsnew/3 5 pep-479-change-stopiteration-handling-inside-generators1634577
Ref: fae1634577
Ref: whatsnew/3 5 whatsnew-pep-4791634577
Ref: f1d1634577
Ref: PEP 479 Change StopIteration handling inside generators-Footnote-11636513
Ref: PEP 479 Change StopIteration handling inside generators-Footnote-21636555
Node: PEP 485 A function for testing approximate equality1636597
Ref: whatsnew/3 5 pep-485-a-function-for-testing-approximate-equality1636836
Ref: fb01636836
Ref: whatsnew/3 5 whatsnew-pep-4851636836
Ref: fb11636836
Ref: PEP 485 A function for testing approximate equality-Footnote-11638023
Ref: PEP 485 A function for testing approximate equality-Footnote-21638065
Node: PEP 486 Make the Python Launcher aware of virtual environments1638107
Ref: whatsnew/3 5 pep-486-make-the-python-launcher-aware-of-virtual-environments1638323
Ref: fb41638323
Ref: whatsnew/3 5 whatsnew-pep-4861638323
Ref: fb51638323
Ref: PEP 486 Make the Python Launcher aware of virtual environments-Footnote-11638903
Ref: PEP 486 Make the Python Launcher aware of virtual environments-Footnote-21638945
Ref: PEP 486 Make the Python Launcher aware of virtual environments-Footnote-31638987
Node: PEP 488 Elimination of PYO files1639029
Ref: whatsnew/3 5 pep-488-elimination-of-pyo-files1639245
Ref: fb61639245
Ref: whatsnew/3 5 whatsnew-pep-4881639245
Ref: f6b1639245
Ref: PEP 488 Elimination of PYO files-Footnote-11640117
Ref: PEP 488 Elimination of PYO files-Footnote-21640159
Node: PEP 489 Multi-phase extension module initialization1640201
Ref: whatsnew/3 5 pep-489-multi-phase-extension-module-initialization1640346
Ref: fb81640346
Ref: whatsnew/3 5 whatsnew-pep-4891640346
Ref: f6c1640346
Ref: PEP 489 Multi-phase extension module initialization-Footnote-11641115
Ref: PEP 489 Multi-phase extension module initialization-Footnote-21641157
Ref: PEP 489 Multi-phase extension module initialization-Footnote-31641199
Node: Other Language Changes<8>1641241
Ref: whatsnew/3 5 other-language-changes1641377
Ref: fb91641377
Ref: Other Language Changes<8>-Footnote-11642377
Ref: Other Language Changes<8>-Footnote-21642442
Ref: Other Language Changes<8>-Footnote-31642507
Ref: Other Language Changes<8>-Footnote-41642572
Ref: Other Language Changes<8>-Footnote-51642637
Ref: Other Language Changes<8>-Footnote-61642702
Ref: Other Language Changes<8>-Footnote-71642767
Node: New Modules<8>1642832
Ref: whatsnew/3 5 new-modules1642971
Ref: fbb1642971
Node: typing<11>1643063
Ref: whatsnew/3 5 typing1643142
Ref: fbc1643142
Node: zipapp<2>1643355
Ref: whatsnew/3 5 whatsnew-zipapp1643434
Ref: f651643434
Ref: whatsnew/3 5 zipapp1643434
Ref: fbd1643434
Ref: zipapp<2>-Footnote-11644150
Ref: zipapp<2>-Footnote-21644192
Ref: zipapp<2>-Footnote-31644259
Ref: zipapp<2>-Footnote-41644324
Node: Improved Modules<8>1644366
Ref: whatsnew/3 5 improved-modules1644506
Ref: fbe1644506
Node: argparse<6>1646232
Ref: whatsnew/3 5 argparse1646319
Ref: fbf1646319
Ref: argparse<6>-Footnote-11646644
Node: asyncio<13>1646709
Ref: whatsnew/3 5 asyncio1646808
Ref: fc21646808
Ref: asyncio<13>-Footnote-11650288
Ref: asyncio<13>-Footnote-21650353
Ref: asyncio<13>-Footnote-31650418
Node: bz21650463
Ref: whatsnew/3 5 bz21650554
Ref: fcb1650554
Ref: bz2-Footnote-11650811
Node: cgi1650876
Ref: whatsnew/3 5 cgi1650964
Ref: fcd1650964
Ref: cgi-Footnote-11651161
Node: cmath<2>1651226
Ref: whatsnew/3 5 cmath1651315
Ref: fce1651315
Ref: cmath<2>-Footnote-11651531
Node: code1651596
Ref: whatsnew/3 5 code1651696
Ref: fcf1651696
Ref: code-Footnote-11651949
Node: collections<5>1652014
Ref: whatsnew/3 5 collections1652124
Ref: fd11652124
Ref: whatsnew/3 5 whatsnew-ordereddict1652167
Ref: f6d1652167
Ref: collections<5>-Footnote-11653451
Ref: collections<5>-Footnote-21653516
Ref: collections<5>-Footnote-31653581
Ref: collections<5>-Footnote-41653646
Ref: collections<5>-Footnote-51653711
Node: collections abc<3>1653776
Ref: whatsnew/3 5 collections-abc1653895
Ref: fdc1653895
Ref: collections abc<3>-Footnote-11654567
Ref: collections abc<3>-Footnote-21654632
Ref: collections abc<3>-Footnote-31654697
Ref: collections abc<3>-Footnote-41654762
Node: compileall<4>1654810
Ref: whatsnew/3 5 compileall1654936
Ref: fe21654936
Ref: compileall<4>-Footnote-11655813
Ref: compileall<4>-Footnote-21655878
Ref: compileall<4>-Footnote-31655943
Node: concurrent futures<6>1656008
Ref: whatsnew/3 5 concurrent-futures1656131
Ref: fe51656131
Ref: concurrent futures<6>-Footnote-11656635
Ref: concurrent futures<6>-Footnote-21656700
Node: configparser<5>1656765
Ref: whatsnew/3 5 configparser1656888
Ref: fe61656888
Ref: configparser<5>-Footnote-11657841
Node: contextlib<5>1657906
Ref: whatsnew/3 5 contextlib1658014
Ref: fe71658014
Ref: contextlib<5>-Footnote-11658626
Node: csv<3>1658691
Ref: whatsnew/3 5 csv1658793
Ref: fea1658793
Ref: csv<3>-Footnote-11658999
Node: curses<5>1659064
Ref: whatsnew/3 5 curses1659159
Ref: fec1659159
Ref: curses<5>-Footnote-11659449
Node: dbm<5>1659513
Ref: whatsnew/3 5 dbm1659612
Ref: ff01659612
Ref: dbm<5>-Footnote-11659817
Node: difflib<3>1659882
Ref: whatsnew/3 5 difflib1659984
Ref: ff11659984
Ref: difflib<3>-Footnote-11660522
Ref: difflib<3>-Footnote-21660586
Node: distutils<7>1660651
Ref: whatsnew/3 5 distutils1660757
Ref: ff41660757
Ref: distutils<7>-Footnote-11661210
Ref: distutils<7>-Footnote-21661274
Node: doctest<3>1661339
Ref: whatsnew/3 5 doctest1661443
Ref: ff51661443
Ref: doctest<3>-Footnote-11661730
Node: email<4>1661795
Ref: whatsnew/3 5 email1661894
Ref: ff81661894
Ref: email<4>-Footnote-11663007
Ref: email<4>-Footnote-21663072
Ref: email<4>-Footnote-31663137
Ref: email<4>-Footnote-41663196
Ref: email<4>-Footnote-51663255
Ref: email<4>-Footnote-61663320
Node: enum<8>1663385
Ref: whatsnew/3 5 enum1663489
Ref: ffe1663489
Ref: enum<8>-Footnote-11663882
Node: faulthandler<4>1663947
Ref: whatsnew/3 5 faulthandler1664055
Ref: fff1664055
Ref: faulthandler<4>-Footnote-11664372
Node: functools<5>1664437
Ref: whatsnew/3 5 functools1664545
Ref: 10031664545
Ref: whatsnew/3 5 whatsnew-lrucache1664586
Ref: f701664586
Ref: functools<5>-Footnote-11664812
Node: glob<3>1664877
Ref: whatsnew/3 5 glob1664977
Ref: 10041664977
Ref: glob<3>-Footnote-11665231
Node: gzip<4>1665296
Ref: whatsnew/3 5 gzip1665392
Ref: 10051665392
Ref: gzip<4>-Footnote-11665619
Node: heapq<2>1665684
Ref: whatsnew/3 5 heapq1665780
Ref: 10061665780
Ref: heapq<2>-Footnote-11666424
Node: http<3>1666489
Ref: whatsnew/3 5 http1666592
Ref: 10091666592
Ref: http<3>-Footnote-11666840
Node: http client<3>1666905
Ref: whatsnew/3 5 http-client1667019
Ref: 100a1667019
Ref: http client<3>-Footnote-11667768
Node: idlelib and IDLE<3>1667832
Ref: whatsnew/3 5 idlelib-and-idle1667949
Ref: 100e1667949
Node: imaplib<3>1668345
Ref: whatsnew/3 5 imaplib1668454
Ref: 100f1668454
Ref: imaplib<3>-Footnote-11669337
Ref: imaplib<3>-Footnote-21669401
Ref: imaplib<3>-Footnote-31669460
Ref: imaplib<3>-Footnote-41669519
Ref: imaplib<3>-Footnote-51669578
Ref: imaplib<3>-Footnote-61669643
Node: imghdr1669708
Ref: whatsnew/3 5 imghdr1669810
Ref: 10121669810
Ref: imghdr-Footnote-11670100
Ref: imghdr-Footnote-21670132
Ref: imghdr-Footnote-31670197
Ref: imghdr-Footnote-41670240
Node: importlib<8>1670305
Ref: whatsnew/3 5 importlib1670407
Ref: 10131670407
Ref: importlib<8>-Footnote-11671248
Ref: importlib<8>-Footnote-21671313
Ref: importlib<8>-Footnote-31671378
Node: inspect<8>1671443
Ref: whatsnew/3 5 inspect1671544
Ref: 10171671544
Ref: inspect<8>-Footnote-11673108
Ref: inspect<8>-Footnote-21673173
Ref: inspect<8>-Footnote-31673238
Ref: inspect<8>-Footnote-41673303
Ref: inspect<8>-Footnote-51673368
Ref: inspect<8>-Footnote-61673433
Ref: inspect<8>-Footnote-71673498
Ref: inspect<8>-Footnote-81673563
Node: io<7>1673628
Ref: whatsnew/3 5 io1673729
Ref: 101d1673729
Ref: io<7>-Footnote-11674032
Node: ipaddress<4>1674097
Ref: whatsnew/3 5 ipaddress1674195
Ref: 10211674195
Ref: ipaddress<4>-Footnote-11675232
Ref: ipaddress<4>-Footnote-21675297
Node: json<3>1675362
Ref: whatsnew/3 5 json1675467
Ref: 10231675467
Ref: json<3>-Footnote-11675970
Ref: json<3>-Footnote-21676035
Node: linecache<3>1676100
Ref: whatsnew/3 5 linecache1676202
Ref: 10251676202
Ref: linecache<3>-Footnote-11676615
Node: locale<6>1676680
Ref: whatsnew/3 5 locale1676785
Ref: 10271676785
Ref: locale<6>-Footnote-11677353
Node: logging<5>1677418
Ref: whatsnew/3 5 logging1677515
Ref: 10291677515
Ref: logging<5>-Footnote-11678492
Ref: logging<5>-Footnote-21678557
Node: lzma1678622
Ref: whatsnew/3 5 lzma1678717
Ref: 102f1678717
Ref: lzma-Footnote-11678982
Node: math<8>1679047
Ref: whatsnew/3 5 math1679150
Ref: 10311679150
Ref: math<8>-Footnote-11679694
Ref: math<8>-Footnote-21679759
Ref: math<8>-Footnote-31679824
Node: multiprocessing<7>1679889
Ref: whatsnew/3 5 multiprocessing1679999
Ref: 10321679999
Ref: multiprocessing<7>-Footnote-11680252
Node: operator<3>1680317
Ref: whatsnew/3 5 operator1680426
Ref: 10341680426
Ref: operator<3>-Footnote-11680837
Ref: operator<3>-Footnote-21680902
Node: os<11>1680967
Ref: whatsnew/3 5 os1681069
Ref: 10391681069
Ref: os<11>-Footnote-11682926
Ref: os<11>-Footnote-21682991
Ref: os<11>-Footnote-31683056
Ref: os<11>-Footnote-41683121
Ref: os<11>-Footnote-51683186
Ref: os<11>-Footnote-61683251
Node: pathlib<13>1683316
Ref: whatsnew/3 5 pathlib1683416
Ref: 10411683416
Ref: pathlib<13>-Footnote-11684896
Ref: pathlib<13>-Footnote-21684961
Ref: pathlib<13>-Footnote-31685026
Ref: pathlib<13>-Footnote-41685091
Ref: pathlib<13>-Footnote-51685156
Node: pickle<4>1685221
Ref: whatsnew/3 5 pickle1685324
Ref: 10491685324
Ref: pickle<4>-Footnote-11685642
Node: poplib<2>1685707
Ref: whatsnew/3 5 poplib1685804
Ref: 104a1685804
Ref: poplib<2>-Footnote-11686049
Ref: poplib<2>-Footnote-21686108
Node: re<8>1686173
Ref: whatsnew/3 5 re1686272
Ref: 104c1686272
Ref: re<8>-Footnote-11687515
Ref: re<8>-Footnote-21687579
Ref: re<8>-Footnote-31687644
Ref: re<8>-Footnote-41687711
Node: readline<2>1687776
Ref: whatsnew/3 5 readline1687875
Ref: 10521687875
Ref: readline<2>-Footnote-11688141
Node: selectors1688206
Ref: whatsnew/3 5 selectors1688309
Ref: 10541688309
Ref: selectors-Footnote-11688533
Node: shutil<5>1688598
Ref: whatsnew/3 5 shutil1688699
Ref: 10551688699
Ref: shutil<5>-Footnote-11689180
Ref: shutil<5>-Footnote-21689245
Node: signal<3>1689309
Ref: whatsnew/3 5 signal1689409
Ref: 10561689409
Ref: signal<3>-Footnote-11689876
Ref: signal<3>-Footnote-21689941
Node: smtpd<2>1690006
Ref: whatsnew/3 5 smtpd1690107
Ref: 10571690107
Ref: smtpd<2>-Footnote-11691745
Ref: smtpd<2>-Footnote-21691810
Ref: smtpd<2>-Footnote-31691869
Ref: smtpd<2>-Footnote-41691934
Ref: smtpd<2>-Footnote-51691993
Ref: smtpd<2>-Footnote-61692058
Node: smtplib<2>1692123
Ref: whatsnew/3 5 smtplib1692221
Ref: 10581692221
Ref: smtplib<2>-Footnote-11692848
Ref: smtplib<2>-Footnote-21692913
Ref: smtplib<2>-Footnote-31692978
Ref: smtplib<2>-Footnote-41693037
Node: sndhdr1693102
Ref: whatsnew/3 5 sndhdr1693201
Ref: 105d1693201
Ref: sndhdr-Footnote-11693406
Node: socket<9>1693471
Ref: whatsnew/3 5 socket1693567
Ref: 105e1693567
Ref: socket<9>-Footnote-11694543
Ref: socket<9>-Footnote-21694608
Ref: socket<9>-Footnote-31694673
Ref: socket<9>-Footnote-41694738
Node: ssl<10>1694803
Ref: whatsnew/3 5 ssl1694903
Ref: 10621694903
Node: Memory BIO Support1695034
Ref: whatsnew/3 5 memory-bio-support1695151
Ref: 10631695151
Ref: whatsnew/3 5 whatsnew-sslmemorybio1695151
Ref: f6e1695151
Ref: Memory BIO Support-Footnote-11696035
Node: Application-Layer Protocol Negotiation Support1696100
Ref: whatsnew/3 5 application-layer-protocol-negotiation-support1696239
Ref: 10651696239
Ref: Application-Layer Protocol Negotiation Support-Footnote-11696949
Ref: Application-Layer Protocol Negotiation Support-Footnote-21697014
Node: Other Changes1697073
Ref: whatsnew/3 5 other-changes1697185
Ref: 10691697185
Ref: Other Changes-Footnote-11698781
Ref: Other Changes-Footnote-21698846
Ref: Other Changes-Footnote-31698911
Ref: Other Changes-Footnote-41698976
Ref: Other Changes-Footnote-51699035
Ref: Other Changes-Footnote-61699100
Ref: Other Changes-Footnote-71699165
Ref: Other Changes-Footnote-81699230
Node: sqlite3<9>1699295
Ref: whatsnew/3 5 sqlite31699399
Ref: 10721699399
Ref: sqlite3<9>-Footnote-11699731
Ref: sqlite3<9>-Footnote-21699796
Node: subprocess<4>1699861
Ref: whatsnew/3 5 subprocess1699965
Ref: 10741699965
Ref: whatsnew/3 5 whatsnew-subprocess1699965
Ref: f711699965
Ref: subprocess<4>-Footnote-11700982
Node: sys<11>1701047
Ref: whatsnew/3 5 sys1701153
Ref: 10761701153
Ref: sys<11>-Footnote-11701805
Ref: sys<11>-Footnote-21701870
Node: sysconfig<3>1701935
Ref: whatsnew/3 5 sysconfig1702038
Ref: 10771702038
Ref: sysconfig<3>-Footnote-11702273
Node: tarfile<7>1702338
Ref: whatsnew/3 5 tarfile1702446
Ref: 10781702446
Ref: tarfile<7>-Footnote-11703362
Ref: tarfile<7>-Footnote-21703427
Ref: tarfile<7>-Footnote-31703492
Node: threading<7>1703557
Ref: whatsnew/3 5 threading1703660
Ref: 107c1703660
Ref: threading<7>-Footnote-11703915
Node: time<7>1703980
Ref: whatsnew/3 5 time1704082
Ref: 107e1704082
Ref: time<7>-Footnote-11704261
Node: timeit<2>1704326
Ref: whatsnew/3 5 timeit1704426
Ref: 107f1704426
Ref: timeit<2>-Footnote-11704894
Ref: timeit<2>-Footnote-21704959
Node: tkinter<9>1705023
Ref: whatsnew/3 5 tkinter1705128
Ref: 10811705128
Ref: tkinter<9>-Footnote-11705462
Node: traceback<5>1705527
Ref: whatsnew/3 5 traceback1705631
Ref: 10821705631
Ref: whatsnew/3 5 whatsnew-traceback1705631
Ref: f721705631
Ref: traceback<5>-Footnote-11706231
Ref: traceback<5>-Footnote-21706296
Ref: traceback<5>-Footnote-31706361
Node: types<6>1706426
Ref: whatsnew/3 5 types1706534
Ref: 10891706534
Ref: types<6>-Footnote-11706982
Ref: types<6>-Footnote-21707047
Node: unicodedata<9>1707112
Ref: whatsnew/3 5 unicodedata1707219
Ref: 108c1707219
Ref: unicodedata<9>-Footnote-11707373
Node: unittest<9>1707424
Ref: whatsnew/3 5 unittest1707539
Ref: 108d1707539
Ref: unittest<9>-Footnote-11708336
Ref: unittest<9>-Footnote-21708401
Ref: unittest<9>-Footnote-31708466
Node: unittest mock<3>1708531
Ref: whatsnew/3 5 unittest-mock1708641
Ref: 108f1708641
Ref: unittest mock<3>-Footnote-11709589
Ref: unittest mock<3>-Footnote-21709654
Ref: unittest mock<3>-Footnote-31709719
Ref: unittest mock<3>-Footnote-41709784
Ref: unittest mock<3>-Footnote-51709849
Ref: unittest mock<3>-Footnote-61709914
Node: urllib<4>1709979
Ref: whatsnew/3 5 urllib1710085
Ref: 10951710085
Ref: urllib<4>-Footnote-11711250
Ref: urllib<4>-Footnote-21711315
Ref: urllib<4>-Footnote-31711379
Ref: urllib<4>-Footnote-41711444
Ref: urllib<4>-Footnote-51711509
Ref: urllib<4>-Footnote-61711568
Ref: urllib<4>-Footnote-71711627
Ref: urllib<4>-Footnote-81711686
Node: wsgiref1711751
Ref: whatsnew/3 5 wsgiref1711850
Ref: 10991711850
Ref: wsgiref-Footnote-11712091
Node: xmlrpc<2>1712155
Ref: whatsnew/3 5 xmlrpc1712252
Ref: 109b1712252
Ref: xmlrpc<2>-Footnote-11712624
Ref: xmlrpc<2>-Footnote-21712689
Node: xml sax1712754
Ref: whatsnew/3 5 xml-sax1712854
Ref: 109c1712854
Ref: xml sax-Footnote-11713191
Ref: xml sax-Footnote-21713255
Node: zipfile<5>1713320
Ref: whatsnew/3 5 zipfile1713402
Ref: 109f1713402
Ref: zipfile<5>-Footnote-11713744
Ref: zipfile<5>-Footnote-21713809
Node: Other module-level changes1713874
Ref: whatsnew/3 5 other-module-level-changes1714016
Ref: 10a01714016
Ref: Other module-level changes-Footnote-11714345
Node: Optimizations<9>1714410
Ref: whatsnew/3 5 optimizations1714559
Ref: 10a11714559
Ref: Optimizations<9>-Footnote-11717630
Ref: Optimizations<9>-Footnote-21717695
Ref: Optimizations<9>-Footnote-31717760
Ref: Optimizations<9>-Footnote-41717825
Ref: Optimizations<9>-Footnote-51717890
Ref: Optimizations<9>-Footnote-61717955
Ref: Optimizations<9>-Footnote-71718020
Ref: Optimizations<9>-Footnote-81718085
Ref: Optimizations<9>-Footnote-91718150
Ref: Optimizations<9>-Footnote-101718215
Ref: Optimizations<9>-Footnote-111718281
Ref: Optimizations<9>-Footnote-121718347
Ref: Optimizations<9>-Footnote-131718413
Ref: Optimizations<9>-Footnote-141718479
Ref: Optimizations<9>-Footnote-151718545
Ref: Optimizations<9>-Footnote-161718611
Ref: Optimizations<9>-Footnote-171718677
Ref: Optimizations<9>-Footnote-181718743
Ref: Optimizations<9>-Footnote-191718809
Ref: Optimizations<9>-Footnote-201718875
Node: Build and C API Changes<3>1718941
Ref: whatsnew/3 5 build-and-c-api-changes1719077
Ref: 10ae1719077
Ref: Build and C API Changes<3>-Footnote-11722646
Ref: Build and C API Changes<3>-Footnote-21722711
Ref: Build and C API Changes<3>-Footnote-31722776
Ref: Build and C API Changes<3>-Footnote-41722841
Ref: Build and C API Changes<3>-Footnote-51722906
Ref: Build and C API Changes<3>-Footnote-61722971
Ref: Build and C API Changes<3>-Footnote-71723013
Ref: Build and C API Changes<3>-Footnote-81723078
Ref: Build and C API Changes<3>-Footnote-91723143
Ref: Build and C API Changes<3>-Footnote-101723185
Node: Deprecated<9>1723291
Ref: whatsnew/3 5 deprecated1723421
Ref: 10ba1723421
Node: New Keywords<2>1723700
Ref: whatsnew/3 5 new-keywords1723803
Ref: 10bb1723803
Ref: New Keywords<2>-Footnote-11724079
Node: Deprecated Python Behavior<2>1724121
Ref: whatsnew/3 5 deprecated-python-behavior1724262
Ref: 10bc1724262
Node: Unsupported Operating Systems1724679
Ref: whatsnew/3 5 unsupported-operating-systems1724855
Ref: 10bd1724855
Ref: Unsupported Operating Systems-Footnote-11725098
Node: Deprecated Python modules functions and methods<3>1725140
Ref: whatsnew/3 5 deprecated-python-modules-functions-and-methods1725278
Ref: 10be1725278
Ref: Deprecated Python modules functions and methods<3>-Footnote-11728196
Ref: Deprecated Python modules functions and methods<3>-Footnote-21728261
Ref: Deprecated Python modules functions and methods<3>-Footnote-31728325
Ref: Deprecated Python modules functions and methods<3>-Footnote-41728390
Ref: Deprecated Python modules functions and methods<3>-Footnote-51728455
Ref: Deprecated Python modules functions and methods<3>-Footnote-61728520
Ref: Deprecated Python modules functions and methods<3>-Footnote-71728585
Ref: Deprecated Python modules functions and methods<3>-Footnote-81728650
Node: Removed<9>1728715
Ref: whatsnew/3 5 removed1728840
Ref: 10c31728840
Node: API and Feature Removals<4>1728940
Ref: whatsnew/3 5 api-and-feature-removals1729014
Ref: 10c41729014
Ref: API and Feature Removals<4>-Footnote-11729873
Ref: API and Feature Removals<4>-Footnote-21729937
Node: Porting to Python 3 51730002
Ref: whatsnew/3 5 porting-to-python-3-51730145
Ref: 10c51730145
Node: Changes in Python behavior<2>1730492
Ref: whatsnew/3 5 changes-in-python-behavior1730616
Ref: 10c61730616
Node: Changes in the Python API<9>1731028
Ref: whatsnew/3 5 changes-in-the-python-api1731184
Ref: 10c71731184
Ref: Changes in the Python API<9>-Footnote-11738113
Ref: Changes in the Python API<9>-Footnote-21738155
Ref: Changes in the Python API<9>-Footnote-31738220
Ref: Changes in the Python API<9>-Footnote-41738285
Ref: Changes in the Python API<9>-Footnote-51738350
Ref: Changes in the Python API<9>-Footnote-61738415
Ref: Changes in the Python API<9>-Footnote-71738480
Ref: Changes in the Python API<9>-Footnote-81738545
Ref: Changes in the Python API<9>-Footnote-91738610
Ref: Changes in the Python API<9>-Footnote-101738675
Ref: Changes in the Python API<9>-Footnote-111738741
Ref: Changes in the Python API<9>-Footnote-121738807
Ref: Changes in the Python API<9>-Footnote-131738872
Ref: Changes in the Python API<9>-Footnote-141738915
Ref: Changes in the Python API<9>-Footnote-151738975
Ref: Changes in the Python API<9>-Footnote-161739041
Ref: Changes in the Python API<9>-Footnote-171739107
Ref: Changes in the Python API<9>-Footnote-181739173
Node: Changes in the C API<8>1739238
Ref: whatsnew/3 5 changes-in-the-c-api1739356
Ref: 10cf1739356
Ref: Changes in the C API<8>-Footnote-11740665
Ref: Changes in the C API<8>-Footnote-21740730
Ref: Changes in the C API<8>-Footnote-31740795
Node: Notable changes in Python 3 5 41740837
Ref: whatsnew/3 5 notable-changes-in-python-3-5-41740961
Ref: 10d31740961
Node: New make regen-all build target<2>1741200
Ref: whatsnew/3 5 new-make-regen-all-build-target1741348
Ref: 10d41741348
Ref: New make regen-all build target<2>-Footnote-11742139
Ref: New make regen-all build target<2>-Footnote-21742207
Node: Removal of make touch build target<2>1742272
Ref: whatsnew/3 5 removal-of-make-touch-build-target1742420
Ref: 10d51742420
Ref: Removal of make touch build target<2>-Footnote-11742857
Node: What’s New In Python 3 41742922
Ref: whatsnew/3 4 doc1743072
Ref: 10d61743072
Ref: whatsnew/3 4 translation-repo1743072
Ref: 10d71743072
Ref: whatsnew/3 4 what-s-new-in-python-3-41743072
Ref: 10d81743072
Ref: What’s New In Python 3 4-Footnote-11743815
Ref: What’s New In Python 3 4-Footnote-21743875
Node: Summary – Release Highlights<3>1743917
Ref: whatsnew/3 4 summary-release-highlights1744038
Ref: 10d91744038
Ref: Summary – Release Highlights<3>-Footnote-11748366
Ref: Summary – Release Highlights<3>-Footnote-21748408
Ref: Summary – Release Highlights<3>-Footnote-31748450
Ref: Summary – Release Highlights<3>-Footnote-41748515
Ref: Summary – Release Highlights<3>-Footnote-51748557
Ref: Summary – Release Highlights<3>-Footnote-61748622
Ref: Summary – Release Highlights<3>-Footnote-71748664
Ref: Summary – Release Highlights<3>-Footnote-81748706
Ref: Summary – Release Highlights<3>-Footnote-91748748
Ref: Summary – Release Highlights<3>-Footnote-101748790
Ref: Summary – Release Highlights<3>-Footnote-111748833
Ref: Summary – Release Highlights<3>-Footnote-121748876
Ref: Summary – Release Highlights<3>-Footnote-131748919
Ref: Summary – Release Highlights<3>-Footnote-141748962
Ref: Summary – Release Highlights<3>-Footnote-151749005
Ref: Summary – Release Highlights<3>-Footnote-161749070
Ref: Summary – Release Highlights<3>-Footnote-171749136
Ref: Summary – Release Highlights<3>-Footnote-181749179
Ref: Summary – Release Highlights<3>-Footnote-191749222
Ref: Summary – Release Highlights<3>-Footnote-201749288
Ref: Summary – Release Highlights<3>-Footnote-211749334
Ref: Summary – Release Highlights<3>-Footnote-221749377
Ref: Summary – Release Highlights<3>-Footnote-231749420
Ref: Summary – Release Highlights<3>-Footnote-241749486
Ref: Summary – Release Highlights<3>-Footnote-251749529
Node: New Features<13>1749572
Ref: whatsnew/3 4 new-features1749716
Ref: 10f41749716
Node: PEP 453 Explicit Bootstrapping of PIP in Python Installations1750208
Ref: whatsnew/3 4 pep-453-explicit-bootstrapping-of-pip-in-python-installations1750389
Ref: 10f51750389
Ref: whatsnew/3 4 whatsnew-pep-4531750389
Ref: 10da1750389
Node: Bootstrapping pip By Default1750603
Ref: whatsnew/3 4 bootstrapping-pip-by-default1750759
Ref: 10f61750759
Ref: Bootstrapping pip By Default-Footnote-11753662
Ref: Bootstrapping pip By Default-Footnote-21753704
Node: Documentation Changes1753791
Ref: whatsnew/3 4 documentation-changes1753947
Ref: 10f91753947
Ref: Documentation Changes-Footnote-11754890
Ref: Documentation Changes-Footnote-21754927
Node: PEP 446 Newly Created File Descriptors Are Non-Inheritable1754969
Ref: whatsnew/3 4 pep-446-newly-created-file-descriptors-are-non-inheritable1755189
Ref: 10fd1755189
Ref: whatsnew/3 4 whatsnew-pep-4461755189
Ref: 10db1755189
Ref: PEP 446 Newly Created File Descriptors Are Non-Inheritable-Footnote-11756220
Ref: PEP 446 Newly Created File Descriptors Are Non-Inheritable-Footnote-21756262
Node: Improvements to Codec Handling1756304
Ref: whatsnew/3 4 codec-handling-improvements1756510
Ref: 10dd1756510
Ref: whatsnew/3 4 improvements-to-codec-handling1756510
Ref: 11051756510
Ref: Improvements to Codec Handling-Footnote-11760722
Ref: Improvements to Codec Handling-Footnote-21760786
Ref: Improvements to Codec Handling-Footnote-31760851
Ref: Improvements to Codec Handling-Footnote-41760916
Node: PEP 451 A ModuleSpec Type for the Import System1760981
Ref: whatsnew/3 4 pep-451-a-modulespec-type-for-the-import-system1761154
Ref: 110a1761154
Ref: whatsnew/3 4 whatsnew-pep-4511761154
Ref: 10de1761154
Ref: PEP 451 A ModuleSpec Type for the Import System-Footnote-11762108
Ref: PEP 451 A ModuleSpec Type for the Import System-Footnote-21762150
Node: Other Language Changes<9>1762230
Ref: whatsnew/3 4 other-language-changes1762364
Ref: 110c1762364
Ref: Other Language Changes<9>-Footnote-11765012
Ref: Other Language Changes<9>-Footnote-21765077
Ref: Other Language Changes<9>-Footnote-31765142
Ref: Other Language Changes<9>-Footnote-41765207
Ref: Other Language Changes<9>-Footnote-51765274
Ref: Other Language Changes<9>-Footnote-61765339
Ref: Other Language Changes<9>-Footnote-71765404
Ref: Other Language Changes<9>-Footnote-81765469
Ref: Other Language Changes<9>-Footnote-91765534
Ref: Other Language Changes<9>-Footnote-101765599
Ref: Other Language Changes<9>-Footnote-111765665
Ref: Other Language Changes<9>-Footnote-121765708
Node: New Modules<9>1765774
Ref: whatsnew/3 4 new-modules1765904
Ref: 11111765904
Node: asyncio<14>1766132
Ref: whatsnew/3 4 asyncio1766215
Ref: 11121766215
Ref: whatsnew/3 4 whatsnew-asyncio1766215
Ref: 10e01766215
Ref: asyncio<14>-Footnote-11766817
Ref: asyncio<14>-Footnote-21766859
Node: ensurepip<2>1766901
Ref: whatsnew/3 4 ensurepip1767000
Ref: 11131767000
Ref: whatsnew/3 4 whatsnew-ensurepip1767000
Ref: 10e11767000
Ref: ensurepip<2>-Footnote-11768274
Node: enum<9>1768316
Ref: whatsnew/3 4 enum1768415
Ref: 11141768415
Ref: whatsnew/3 4 whatsnew-enum1768415
Ref: 10e21768415
Ref: enum<9>-Footnote-11768991
Ref: enum<9>-Footnote-21769033
Node: pathlib<14>1769075
Ref: whatsnew/3 4 pathlib1769174
Ref: 11151769174
Ref: whatsnew/3 4 whatsnew-pathlib1769174
Ref: 10e31769174
Ref: pathlib<14>-Footnote-11769798
Node: selectors<2>1769840
Ref: whatsnew/3 4 selectors1769945
Ref: 11161769945
Ref: whatsnew/3 4 whatsnew-selectors1769945
Ref: 10e41769945
Ref: selectors<2>-Footnote-11770205
Node: statistics<5>1770247
Ref: whatsnew/3 4 statistics1770355
Ref: 11171770355
Ref: whatsnew/3 4 whatsnew-statistics1770355
Ref: 10e51770355
Ref: statistics<5>-Footnote-11770826
Ref: statistics<5>-Footnote-21770868
Node: tracemalloc<4>1770910
Ref: whatsnew/3 4 tracemalloc1770997
Ref: 11181770997
Ref: whatsnew/3 4 whatsnew-tracemalloc1770997
Ref: 10e61770997
Ref: tracemalloc<4>-Footnote-11771668
Ref: tracemalloc<4>-Footnote-21771710
Node: Improved Modules<9>1771752
Ref: whatsnew/3 4 improved-modules1771896
Ref: 11191771896
Node: abc1773266
Ref: whatsnew/3 4 abc1773341
Ref: 111a1773341
Ref: abc-Footnote-11773867
Ref: abc-Footnote-21773932
Node: aifc<2>1773997
Ref: whatsnew/3 4 aifc1774092
Ref: 111e1774092
Ref: aifc<2>-Footnote-11774702
Ref: aifc<2>-Footnote-21774767
Ref: aifc<2>-Footnote-31774832
Node: argparse<7>1774896
Ref: whatsnew/3 4 argparse1774995
Ref: 111f1774995
Ref: argparse<7>-Footnote-11775243
Node: audioop1775308
Ref: whatsnew/3 4 audioop1775409
Ref: 11201775409
Ref: audioop-Footnote-11775935
Ref: audioop-Footnote-21776000
Ref: audioop-Footnote-31776065
Node: base64<4>1776130
Ref: whatsnew/3 4 base641776234
Ref: 11211776234
Ref: base64<4>-Footnote-11777071
Ref: base64<4>-Footnote-21777136
Node: collections<6>1777201
Ref: whatsnew/3 4 collections1777306
Ref: 11261777306
Ref: collections<6>-Footnote-11777639
Node: colorsys1777704
Ref: whatsnew/3 4 colorsys1777813
Ref: 11281777813
Ref: colorsys-Footnote-11778183
Node: contextlib<6>1778248
Ref: whatsnew/3 4 contextlib1778349
Ref: 11291778349
Ref: contextlib<6>-Footnote-11779539
Ref: contextlib<6>-Footnote-21779604
Ref: contextlib<6>-Footnote-31779669
Node: dbm<6>1779734
Ref: whatsnew/3 4 dbm1779833
Ref: 112d1779833
Ref: dbm<6>-Footnote-11780183
Node: dis<5>1780248
Ref: whatsnew/3 4 dis1780344
Ref: 112f1780344
Ref: dis<5>-Footnote-11782956
Ref: dis<5>-Footnote-21783021
Ref: dis<5>-Footnote-31783086
Node: doctest<4>1783151
Ref: whatsnew/3 4 doctest1783249
Ref: 11341783249
Ref: doctest<4>-Footnote-11784022
Ref: doctest<4>-Footnote-21784087
Ref: doctest<4>-Footnote-31784152
Node: email<5>1784216
Ref: whatsnew/3 4 email1784315
Ref: 11371784315
Ref: whatsnew/3 4 whatsnew-email-contentmanager1785569
Ref: 10ea1785569
Ref: email<5>-Footnote-11786501
Ref: email<5>-Footnote-21786566
Ref: email<5>-Footnote-31786631
Ref: email<5>-Footnote-41786696
Node: filecmp1786761
Ref: whatsnew/3 4 filecmp1786862
Ref: 113f1786862
Ref: filecmp-Footnote-11787613
Ref: filecmp-Footnote-21787678
Node: functools<6>1787743
Ref: whatsnew/3 4 functools1787841
Ref: 11431787841
Ref: whatsnew/3 4 whatsnew-singledispatch1788290
Ref: 10e71788290
Ref: functools<6>-Footnote-11789254
Ref: functools<6>-Footnote-21789318
Ref: functools<6>-Footnote-31789360
Ref: functools<6>-Footnote-41789425
Node: gc<6>1789490
Ref: whatsnew/3 4 gc1789588
Ref: 11451789588
Ref: gc<6>-Footnote-11789856
Node: glob<4>1789921
Ref: whatsnew/3 4 glob1790017
Ref: 11461790017
Ref: glob<4>-Footnote-11790324
Node: hashlib<6>1790388
Ref: whatsnew/3 4 hashlib1790486
Ref: 11481790486
Ref: hashlib<6>-Footnote-11791122
Ref: hashlib<6>-Footnote-21791167
Ref: hashlib<6>-Footnote-31791232
Node: hmac<4>1791297
Ref: whatsnew/3 4 hmac1791392
Ref: 114a1791392
Ref: hmac<4>-Footnote-11792424
Ref: hmac<4>-Footnote-21792489
Ref: hmac<4>-Footnote-31792554
Ref: hmac<4>-Footnote-41792596
Node: html1792661
Ref: whatsnew/3 4 html1792753
Ref: 114f1792753
Ref: html-Footnote-11793512
Ref: html-Footnote-21793576
Ref: html-Footnote-31793641
Node: http<4>1793706
Ref: whatsnew/3 4 http1793810
Ref: 11501793810
Ref: http<4>-Footnote-11794461
Ref: http<4>-Footnote-21794526
Node: idlelib and IDLE<4>1794591
Ref: whatsnew/3 4 idlelib-and-idle1794703
Ref: 11541794703
Node: importlib<9>1795099
Ref: whatsnew/3 4 importlib1795214
Ref: 11551795214
Ref: importlib<9>-Footnote-11797206
Ref: importlib<9>-Footnote-21797271
Ref: importlib<9>-Footnote-31797336
Ref: importlib<9>-Footnote-41797401
Ref: importlib<9>-Footnote-51797466
Ref: importlib<9>-Footnote-61797531
Ref: importlib<9>-Footnote-71797596
Node: inspect<9>1797661
Ref: whatsnew/3 4 inspect1797769
Ref: 115c1797769
Ref: inspect<9>-Footnote-11799482
Ref: inspect<9>-Footnote-21799547
Ref: inspect<9>-Footnote-31799612
Ref: inspect<9>-Footnote-41799677
Ref: inspect<9>-Footnote-51799742
Ref: inspect<9>-Footnote-61799807
Node: ipaddress<5>1799872
Ref: whatsnew/3 4 ipaddress1799978
Ref: 11601799978
Ref: ipaddress<5>-Footnote-11800507
Node: logging<6>1800572
Ref: whatsnew/3 4 logging1800678
Ref: 11621800678
Ref: logging<6>-Footnote-11801815
Ref: logging<6>-Footnote-21801879
Ref: logging<6>-Footnote-31801944
Node: marshal<2>1802009
Ref: whatsnew/3 4 marshal1802110
Ref: 11681802110
Ref: whatsnew/3 4 whatsnew-marshal-31802110
Ref: 10df1802110
Ref: marshal<2>-Footnote-11802789
Ref: marshal<2>-Footnote-21802854
Node: mmap<3>1802919
Ref: whatsnew/3 4 mmap1803028
Ref: 11691803028
Ref: mmap<3>-Footnote-11803201
Node: multiprocessing<8>1803265
Ref: whatsnew/3 4 multiprocessing1803375
Ref: 116a1803375
Ref: whatsnew/3 4 whatsnew-multiprocessing-no-fork1803428
Ref: 10e91803428
Ref: multiprocessing<8>-Footnote-11805243
Ref: multiprocessing<8>-Footnote-21805307
Ref: multiprocessing<8>-Footnote-31805372
Ref: multiprocessing<8>-Footnote-41805436
Node: operator<4>1805501
Ref: whatsnew/3 4 operator1805610
Ref: 116e1805610
Ref: operator<4>-Footnote-11806165
Ref: operator<4>-Footnote-21806207
Ref: operator<4>-Footnote-31806272
Node: os<12>1806337
Ref: whatsnew/3 4 os1806434
Ref: 11701806434
Ref: os<12>-Footnote-11807890
Ref: os<12>-Footnote-21807955
Ref: os<12>-Footnote-31808020
Ref: os<12>-Footnote-41808084
Node: pdb<8>1808149
Ref: whatsnew/3 4 pdb1808244
Ref: 11761808244
Ref: pdb<8>-Footnote-11809242
Ref: pdb<8>-Footnote-21809307
Node: pickle<5>1809372
Ref: whatsnew/3 4 pickle1809472
Ref: 11791809472
Ref: whatsnew/3 4 whatsnew-protocol-41809472
Ref: 10e81809472
Ref: pickle<5>-Footnote-11810073
Node: plistlib<2>1810115
Ref: whatsnew/3 4 plistlib1810218
Ref: 117a1810218
Ref: plistlib<2>-Footnote-11810755
Node: poplib<3>1810820
Ref: whatsnew/3 4 poplib1810923
Ref: 117d1810923
Ref: poplib<3>-Footnote-11811314
Node: pprint<4>1811378
Ref: whatsnew/3 4 pprint1811476
Ref: 11801811476
Ref: pprint<4>-Footnote-11812098
Ref: pprint<4>-Footnote-21812163
Node: pty<2>1812228
Ref: whatsnew/3 4 pty1812325
Ref: 11831812325
Node: pydoc<5>1812519
Ref: whatsnew/3 4 pydoc1812612
Ref: 11851812612
Ref: pydoc<5>-Footnote-11813669
Ref: pydoc<5>-Footnote-21813734
Node: re<9>1813799
Ref: whatsnew/3 4 re1813894
Ref: 11861813894
Ref: re<9>-Footnote-11814649
Ref: re<9>-Footnote-21814714
Ref: re<9>-Footnote-31814779
Node: resource1814844
Ref: whatsnew/3 4 resource1814937
Ref: 118b1814937
Ref: resource-Footnote-11815799
Ref: resource-Footnote-21815864
Ref: resource-Footnote-31815929
Node: select1815994
Ref: whatsnew/3 4 select1816091
Ref: 11951816091
Ref: select-Footnote-11816606
Ref: select-Footnote-21816671
Node: shelve<2>1816736
Ref: whatsnew/3 4 shelve1816834
Ref: 119c1816834
Ref: shelve<2>-Footnote-11817107
Node: shutil<6>1817172
Ref: whatsnew/3 4 shutil1817272
Ref: 119e1817272
Ref: shutil<6>-Footnote-11817647
Node: smtpd<3>1817714
Ref: whatsnew/3 4 smtpd1817815
Ref: 11a11817815
Ref: smtpd<3>-Footnote-11818175
Node: smtplib<3>1818240
Ref: whatsnew/3 4 smtplib1818342
Ref: 11a21818342
Ref: smtplib<3>-Footnote-11818705
Node: socket<10>1818769
Ref: whatsnew/3 4 socket1818874
Ref: 11a41818874
Ref: socket<10>-Footnote-11819661
Ref: socket<10>-Footnote-21819726
Node: sqlite3<10>1819790
Ref: whatsnew/3 4 sqlite31819892
Ref: 11a81819892
Ref: sqlite3<10>-Footnote-11820183
Ref: sqlite3<10>-Footnote-21820223
Node: ssl<11>1820288
Ref: whatsnew/3 4 ssl1820384
Ref: 11a91820384
Ref: whatsnew/3 4 whatsnew-tls-11-121820413
Ref: 10ec1820413
Ref: whatsnew/3 4 whatsnew34-sslcontext1820685
Ref: 10ef1820685
Ref: whatsnew/3 4 whatsnew34-win-cert-store1823369
Ref: 10ed1823369
Ref: whatsnew/3 4 whatsnew34-sni1823625
Ref: 10ee1823625
Ref: ssl<11>-Footnote-11824076
Ref: ssl<11>-Footnote-21824141
Ref: ssl<11>-Footnote-31824206
Ref: ssl<11>-Footnote-41824271
Ref: ssl<11>-Footnote-51824336
Ref: ssl<11>-Footnote-61824401
Ref: ssl<11>-Footnote-71824465
Ref: ssl<11>-Footnote-81824530
Ref: ssl<11>-Footnote-91824595
Ref: ssl<11>-Footnote-101824659
Node: stat1824725
Ref: whatsnew/3 4 stat1824819
Ref: 11bb1824819
Ref: stat-Footnote-11825296
Ref: stat-Footnote-21825361
Node: struct<3>1825426
Ref: whatsnew/3 4 struct1825526
Ref: 11c01825526
Ref: struct<3>-Footnote-11825860
Node: subprocess<5>1825925
Ref: whatsnew/3 4 subprocess1826029
Ref: 11c31826029
Ref: subprocess<5>-Footnote-11826484
Ref: subprocess<5>-Footnote-21826549
Node: sunau<2>1826614
Ref: whatsnew/3 4 sunau1826716
Ref: 11c71826716
Ref: sunau<2>-Footnote-11827500
Ref: sunau<2>-Footnote-21827565
Ref: sunau<2>-Footnote-31827630
Ref: sunau<2>-Footnote-41827695
Node: sys<12>1827759
Ref: whatsnew/3 4 sys1827858
Ref: 11c81827858
Ref: sys<12>-Footnote-11829150
Ref: sys<12>-Footnote-21829215
Node: tarfile<8>1829279
Ref: whatsnew/3 4 tarfile1829381
Ref: 11cc1829381
Ref: tarfile<8>-Footnote-11829700
Node: textwrap<2>1829765
Ref: whatsnew/3 4 textwrap1829872
Ref: 11ce1829872
Ref: textwrap<2>-Footnote-11830577
Ref: textwrap<2>-Footnote-21830642
Node: threading<8>1830707
Ref: whatsnew/3 4 threading1830816
Ref: 11d31830816
Ref: threading<8>-Footnote-11831162
Node: traceback<6>1831227
Ref: whatsnew/3 4 traceback1831333
Ref: 11d51831333
Ref: traceback<6>-Footnote-11831649
Node: types<7>1831716
Ref: whatsnew/3 4 types1831819
Ref: 11d71831819
Ref: types<7>-Footnote-11832330
Node: urllib<5>1832395
Ref: whatsnew/3 4 urllib1832498
Ref: 11d81832498
Ref: urllib<5>-Footnote-11833828
Ref: urllib<5>-Footnote-21833893
Ref: urllib<5>-Footnote-31833958
Ref: urllib<5>-Footnote-41834023
Ref: urllib<5>-Footnote-51834088
Ref: urllib<5>-Footnote-61834153
Node: unittest<10>1834218
Ref: whatsnew/3 4 unittest1834320
Ref: 11e21834320
Ref: unittest<10>-Footnote-11837488
Ref: unittest<10>-Footnote-21837553
Ref: unittest<10>-Footnote-31837618
Ref: unittest<10>-Footnote-41837683
Ref: unittest<10>-Footnote-51837748
Ref: unittest<10>-Footnote-61837813
Ref: unittest<10>-Footnote-71837878
Ref: unittest<10>-Footnote-81837943
Ref: unittest<10>-Footnote-91838008
Node: venv<7>1838073
Ref: whatsnew/3 4 venv1838173
Ref: 11ea1838173
Ref: venv<7>-Footnote-11838731
Ref: venv<7>-Footnote-21838796
Ref: venv<7>-Footnote-31838861
Node: wave<2>1838903
Ref: whatsnew/3 4 wave1839001
Ref: 11eb1839001
Ref: wave<2>-Footnote-11839648
Ref: wave<2>-Footnote-21839713
Ref: wave<2>-Footnote-31839778
Ref: wave<2>-Footnote-41839842
Node: weakref<2>1839906
Ref: whatsnew/3 4 weakref1840009
Ref: 11f01840009
Ref: weakref<2>-Footnote-11840633
Ref: weakref<2>-Footnote-21840698
Ref: weakref<2>-Footnote-31840763
Node: xml etree<2>1840828
Ref: whatsnew/3 4 xml-etree1840934
Ref: 11f41840934
Ref: xml etree<2>-Footnote-11841677
Ref: xml etree<2>-Footnote-21841742
Node: zipfile<6>1841807
Ref: whatsnew/3 4 zipfile1841894
Ref: 11f91841894
Ref: zipfile<6>-Footnote-11842434
Ref: zipfile<6>-Footnote-21842499
Node: CPython Implementation Changes1842564
Ref: whatsnew/3 4 cpython-implementation-changes1842708
Ref: 11fc1842708
Node: PEP 445 Customization of CPython Memory Allocators1843240
Ref: whatsnew/3 4 pep-445-customization-of-cpython-memory-allocators1843398
Ref: 11fd1843398
Ref: whatsnew/3 4 whatsnew-pep-4451843398
Ref: 10f21843398
Ref: PEP 445 Customization of CPython Memory Allocators-Footnote-11843799
Ref: PEP 445 Customization of CPython Memory Allocators-Footnote-21843841
Node: PEP 442 Safe Object Finalization1843883
Ref: whatsnew/3 4 pep-442-safe-object-finalization1844099
Ref: 11fe1844099
Ref: whatsnew/3 4 whatsnew-pep-4421844099
Ref: 10f11844099
Ref: PEP 442 Safe Object Finalization-Footnote-11844973
Ref: PEP 442 Safe Object Finalization-Footnote-21845015
Node: PEP 456 Secure and Interchangeable Hash Algorithm1845057
Ref: whatsnew/3 4 pep-456-secure-and-interchangeable-hash-algorithm1845246
Ref: 12001845246
Ref: whatsnew/3 4 whatsnew-pep-4561845246
Ref: 10eb1845246
Ref: PEP 456 Secure and Interchangeable Hash Algorithm-Footnote-11846195
Ref: PEP 456 Secure and Interchangeable Hash Algorithm-Footnote-21846237
Node: PEP 436 Argument Clinic1846302
Ref: whatsnew/3 4 pep-436-argument-clinic1846488
Ref: 12021846488
Ref: whatsnew/3 4 whatsnew-pep-4361846488
Ref: 10f31846488
Ref: PEP 436 Argument Clinic-Footnote-11847598
Ref: PEP 436 Argument Clinic-Footnote-21847640
Node: Other Build and C API Changes1847682
Ref: whatsnew/3 4 other-build-and-c-api-changes1847840
Ref: 12031847840
Ref: Other Build and C API Changes-Footnote-11849928
Ref: Other Build and C API Changes-Footnote-21849993
Ref: Other Build and C API Changes-Footnote-31850058
Ref: Other Build and C API Changes-Footnote-41850125
Ref: Other Build and C API Changes-Footnote-51850189
Ref: Other Build and C API Changes-Footnote-61850254
Ref: Other Build and C API Changes-Footnote-71850327
Ref: Other Build and C API Changes-Footnote-81850391
Ref: Other Build and C API Changes-Footnote-91850456
Node: Other Improvements<2>1850521
Ref: whatsnew/3 4 other-improvements1850681
Ref: 12071850681
Ref: whatsnew/3 4 other-improvements-3-41850681
Ref: 12081850681
Ref: whatsnew/3 4 whatsnew-isolated-mode1850738
Ref: 10dc1850738
Ref: Other Improvements<2>-Footnote-11854861
Ref: Other Improvements<2>-Footnote-21854926
Ref: Other Improvements<2>-Footnote-31854990
Ref: Other Improvements<2>-Footnote-41855055
Ref: Other Improvements<2>-Footnote-51855120
Ref: Other Improvements<2>-Footnote-61855185
Ref: Other Improvements<2>-Footnote-71855250
Ref: Other Improvements<2>-Footnote-81855345
Ref: Other Improvements<2>-Footnote-91855396
Ref: Other Improvements<2>-Footnote-101855461
Ref: Other Improvements<2>-Footnote-111855527
Ref: Other Improvements<2>-Footnote-121855593
Ref: Other Improvements<2>-Footnote-131855636
Ref: Other Improvements<2>-Footnote-141855702
Ref: Other Improvements<2>-Footnote-151855768
Ref: Other Improvements<2>-Footnote-161855834
Ref: Other Improvements<2>-Footnote-171855900
Ref: Other Improvements<2>-Footnote-181855943
Ref: Other Improvements<2>-Footnote-191856009
Ref: Other Improvements<2>-Footnote-201856075
Ref: Other Improvements<2>-Footnote-211856141
Node: Significant Optimizations1856207
Ref: whatsnew/3 4 significant-optimizations1856329
Ref: 120d1856329
Ref: Significant Optimizations-Footnote-11859137
Ref: Significant Optimizations-Footnote-21859202
Ref: Significant Optimizations-Footnote-31859267
Ref: Significant Optimizations-Footnote-41859332
Ref: Significant Optimizations-Footnote-51859397
Ref: Significant Optimizations-Footnote-61859462
Ref: Significant Optimizations-Footnote-71859527
Ref: Significant Optimizations-Footnote-81859591
Ref: Significant Optimizations-Footnote-91859656
Ref: Significant Optimizations-Footnote-101859721
Ref: Significant Optimizations-Footnote-111859787
Ref: Significant Optimizations-Footnote-121859853
Ref: Significant Optimizations-Footnote-131859919
Node: Deprecated<10>1859985
Ref: whatsnew/3 4 deprecated1860121
Ref: 12111860121
Ref: whatsnew/3 4 deprecated-3-41860121
Ref: 110b1860121
Node: Deprecations in the Python API1860563
Ref: whatsnew/3 4 deprecations-in-the-python-api1860672
Ref: 12121860672
Node: Deprecated Features1864321
Ref: whatsnew/3 4 deprecated-features1864430
Ref: 12161864430
Ref: Deprecated Features-Footnote-11864842
Ref: Deprecated Features-Footnote-21864907
Node: Removed<10>1864972
Ref: whatsnew/3 4 removed1865099
Ref: 12181865099
Node: Operating Systems No Longer Supported1865257
Ref: whatsnew/3 4 operating-systems-no-longer-supported1865378
Ref: 12191865378
Ref: Operating Systems No Longer Supported-Footnote-11865793
Ref: Operating Systems No Longer Supported-Footnote-21865858
Ref: Operating Systems No Longer Supported-Footnote-31865923
Node: API and Feature Removals<5>1865988
Ref: whatsnew/3 4 api-and-feature-removals1866131
Ref: 121a1866131
Ref: API and Feature Removals<5>-Footnote-11868585
Ref: API and Feature Removals<5>-Footnote-21868621
Ref: API and Feature Removals<5>-Footnote-31868686
Ref: API and Feature Removals<5>-Footnote-41868751
Ref: API and Feature Removals<5>-Footnote-51868816
Ref: API and Feature Removals<5>-Footnote-61868881
Ref: API and Feature Removals<5>-Footnote-71868945
Node: Code Cleanups1869010
Ref: whatsnew/3 4 code-cleanups1869107
Ref: 121c1869107
Ref: Code Cleanups-Footnote-11869771
Node: Porting to Python 3 41869836
Ref: whatsnew/3 4 porting-to-python-3-41869965
Ref: 121d1869965
Node: Changes in “python” Command Behavior<2>1870339
Ref: whatsnew/3 4 changes-in-python-command-behavior1870478
Ref: 121e1870478
Ref: Changes in “python” Command Behavior<2>-Footnote-11871593
Node: Changes in the Python API<10>1871658
Ref: whatsnew/3 4 changes-in-the-python-api1871829
Ref: 12201871829
Ref: Changes in the Python API<10>-Footnote-11885240
Ref: Changes in the Python API<10>-Footnote-21885305
Ref: Changes in the Python API<10>-Footnote-31885370
Ref: Changes in the Python API<10>-Footnote-41885435
Ref: Changes in the Python API<10>-Footnote-51885500
Ref: Changes in the Python API<10>-Footnote-61885565
Ref: Changes in the Python API<10>-Footnote-71885630
Ref: Changes in the Python API<10>-Footnote-81885695
Ref: Changes in the Python API<10>-Footnote-91885759
Ref: Changes in the Python API<10>-Footnote-101885824
Ref: Changes in the Python API<10>-Footnote-111885890
Ref: Changes in the Python API<10>-Footnote-121885956
Ref: Changes in the Python API<10>-Footnote-131886022
Ref: Changes in the Python API<10>-Footnote-141886088
Ref: Changes in the Python API<10>-Footnote-151886154
Ref: Changes in the Python API<10>-Footnote-161886220
Ref: Changes in the Python API<10>-Footnote-171886286
Ref: Changes in the Python API<10>-Footnote-181886352
Ref: Changes in the Python API<10>-Footnote-191886418
Ref: Changes in the Python API<10>-Footnote-201886484
Ref: Changes in the Python API<10>-Footnote-211886550
Ref: Changes in the Python API<10>-Footnote-221886616
Ref: Changes in the Python API<10>-Footnote-231886682
Ref: Changes in the Python API<10>-Footnote-241886747
Node: Changes in the C API<9>1886813
Ref: whatsnew/3 4 changes-in-the-c-api1886932
Ref: 122f1886932
Ref: Changes in the C API<9>-Footnote-11888699
Ref: Changes in the C API<9>-Footnote-21888764
Node: Changed in 3 4 31888829
Ref: whatsnew/3 4 changed-in-3-4-31888938
Ref: 12351888938
Node: PEP 476 Enabling certificate verification by default for stdlib http clients1889156
Ref: whatsnew/3 4 pep-4761889285
Ref: 12361889285
Ref: whatsnew/3 4 pep-476-enabling-certificate-verification-by-default-for-stdlib-http-clients1889285
Ref: 12371889285
Node: What’s New In Python 3 31890286
Ref: whatsnew/3 3 doc1890436
Ref: 12381890436
Ref: whatsnew/3 3 translation-repo1890436
Ref: 12391890436
Ref: whatsnew/3 3 what-s-new-in-python-3-31890436
Ref: 123a1890436
Ref: What’s New In Python 3 3-Footnote-11892387
Ref: What’s New In Python 3 3-Footnote-21892447
Node: Summary – Release highlights<8>1892489
Ref: whatsnew/3 3 summary-release-highlights1892622
Ref: 123b1892622
Node: PEP 405 Virtual Environments1893962
Ref: whatsnew/3 3 pep-4051894139
Ref: 123d1894139
Ref: whatsnew/3 3 pep-405-virtual-environments1894139
Ref: 12451894139
Ref: PEP 405 Virtual Environments-Footnote-11895133
Node: PEP 420 Implicit Namespace Packages1895175
Ref: whatsnew/3 3 pep-420-implicit-namespace-packages1895391
Ref: 12461895391
Ref: PEP 420 Implicit Namespace Packages-Footnote-11895908
Ref: PEP 420 Implicit Namespace Packages-Footnote-21895950
Node: PEP 3118 New memoryview implementation and buffer protocol documentation1895992
Ref: whatsnew/3 3 pep-3118-new-memoryview-implementation-and-buffer-protocol-documentation1896218
Ref: 12471896218
Ref: whatsnew/3 3 pep-3118-update1896218
Ref: 12481896218
Ref: PEP 3118 New memoryview implementation and buffer protocol documentation-Footnote-11897350
Node: Features1897392
Ref: whatsnew/3 3 features1897529
Ref: 12491897529
Ref: Features-Footnote-11898333
Node: API changes1898398
Ref: whatsnew/3 3 api-changes1898535
Ref: 124a1898535
Ref: API changes-Footnote-11899558
Ref: API changes-Footnote-21899623
Node: PEP 393 Flexible String Representation1899665
Ref: whatsnew/3 3 pep-3931899891
Ref: 12401899891
Ref: whatsnew/3 3 pep-393-flexible-string-representation1899891
Ref: 124d1899891
Ref: PEP 393 Flexible String Representation-Footnote-11900952
Node: Functionality1900994
Ref: whatsnew/3 3 functionality1901121
Ref: 124e1901121
Ref: Functionality-Footnote-11902571
Ref: Functionality-Footnote-21902613
Node: Performance and resource usage1902678
Ref: whatsnew/3 3 performance-and-resource-usage1902805
Ref: 12501902805
Ref: Performance and resource usage-Footnote-11904042
Node: PEP 397 Python Launcher for Windows1904084
Ref: whatsnew/3 3 pep-3971904290
Ref: 12511904290
Ref: whatsnew/3 3 pep-397-python-launcher-for-windows1904290
Ref: 12521904290
Ref: PEP 397 Python Launcher for Windows-Footnote-11905825
Ref: PEP 397 Python Launcher for Windows-Footnote-21905889
Node: PEP 3151 Reworking the OS and IO exception hierarchy1905931
Ref: whatsnew/3 3 pep-31511906146
Ref: 123e1906146
Ref: whatsnew/3 3 pep-3151-reworking-the-os-and-io-exception-hierarchy1906146
Ref: 12541906146
Ref: PEP 3151 Reworking the OS and IO exception hierarchy-Footnote-11908737
Node: PEP 380 Syntax for Delegating to a Subgenerator1908779
Ref: whatsnew/3 3 pep-3801908996
Ref: 123c1908996
Ref: whatsnew/3 3 pep-380-syntax-for-delegating-to-a-subgenerator1908996
Ref: 12621908996
Ref: PEP 380 Syntax for Delegating to a Subgenerator-Footnote-11911446
Node: PEP 409 Suppressing exception context1911488
Ref: whatsnew/3 3 pep-409-suppressing-exception-context1911686
Ref: 12641911686
Ref: PEP 409 Suppressing exception context-Footnote-11913780
Node: PEP 414 Explicit Unicode literals1913822
Ref: whatsnew/3 3 pep-414-explicit-unicode-literals1914022
Ref: 12651914022
Ref: PEP 414 Explicit Unicode literals-Footnote-11914739
Node: PEP 3155 Qualified name for classes and functions1914781
Ref: whatsnew/3 3 pep-3155-qualified-name-for-classes-and-functions1914974
Ref: 12661914974
Ref: PEP 3155 Qualified name for classes and functions-Footnote-11916593
Node: PEP 412 Key-Sharing Dictionary1916635
Ref: whatsnew/3 3 pep-4121916828
Ref: 12411916828
Ref: whatsnew/3 3 pep-412-key-sharing-dictionary1916828
Ref: 12691916828
Ref: PEP 412 Key-Sharing Dictionary-Footnote-11917353
Node: PEP 362 Function Signature Object1917395
Ref: whatsnew/3 3 pep-362-function-signature-object1917572
Ref: 126a1917572
Ref: PEP 362 Function Signature Object-Footnote-11918473
Node: PEP 421 Adding sys implementation1918515
Ref: whatsnew/3 3 pep-421-adding-sys-implementation1918709
Ref: 126c1918709
Ref: PEP 421 Adding sys implementation-Footnote-11919925
Node: SimpleNamespace1919967
Ref: whatsnew/3 3 simplenamespace1920052
Ref: 126d1920052
Ref: SimpleNamespace-Footnote-11920676
Node: Using importlib as the Implementation of Import1920718
Ref: whatsnew/3 3 importlib1920905
Ref: 123f1920905
Ref: whatsnew/3 3 using-importlib-as-the-implementation-of-import1920905
Ref: 126e1920905
Ref: Using importlib as the Implementation of Import-Footnote-11922183
Ref: Using importlib as the Implementation of Import-Footnote-21922247
Ref: Using importlib as the Implementation of Import-Footnote-31922312
Ref: Using importlib as the Implementation of Import-Footnote-41922377
Ref: Using importlib as the Implementation of Import-Footnote-51922442
Node: New APIs1922484
Ref: whatsnew/3 3 new-apis1922600
Ref: 12711922600
Node: Visible Changes1924445
Ref: whatsnew/3 3 visible-changes1924561
Ref: 12781924561
Ref: Visible Changes-Footnote-11926416
Ref: Visible Changes-Footnote-21926458
Node: Other Language Changes<10>1926500
Ref: whatsnew/3 3 other-language-changes1926681
Ref: 12791926681
Ref: Other Language Changes<10>-Footnote-11928646
Ref: Other Language Changes<10>-Footnote-21928711
Ref: Other Language Changes<10>-Footnote-31928776
Ref: Other Language Changes<10>-Footnote-41928841
Ref: Other Language Changes<10>-Footnote-51928906
Ref: Other Language Changes<10>-Footnote-61928971
Ref: Other Language Changes<10>-Footnote-71929036
Ref: Other Language Changes<10>-Footnote-81929101
Node: A Finer-Grained Import Lock1929166
Ref: whatsnew/3 3 a-finer-grained-import-lock1929327
Ref: 127c1929327
Ref: A Finer-Grained Import Lock-Footnote-11930072
Node: Builtin functions and types1930136
Ref: whatsnew/3 3 builtin-functions-and-types1930286
Ref: 127d1930286
Ref: Builtin functions and types-Footnote-11931524
Node: New Modules<10>1931588
Ref: whatsnew/3 3 new-modules1931731
Ref: 12801931731
Node: faulthandler<5>1931859
Ref: whatsnew/3 3 faulthandler1931947
Ref: 12811931947
Node: ipaddress<6>1932906
Ref: whatsnew/3 3 ipaddress1933010
Ref: 12881933010
Ref: ipaddress<6>-Footnote-11933356
Node: lzma<2>1933398
Ref: whatsnew/3 3 lzma1933478
Ref: 12891933478
Ref: lzma<2>-Footnote-11933792
Node: Improved Modules<10>1933856
Ref: whatsnew/3 3 improved-modules1933989
Ref: 128a1933989
Node: abc<2>1935326
Ref: whatsnew/3 3 abc1935406
Ref: 128b1935406
Ref: abc<2>-Footnote-11936392
Ref: abc<2>-Footnote-21936457
Node: array<5>1936522
Ref: whatsnew/3 3 array1936620
Ref: 12911936620
Ref: array<5>-Footnote-11936854
Node: base64<5>1936921
Ref: whatsnew/3 3 base641937024
Ref: 12921937024
Ref: base64<5>-Footnote-11937324
Node: binascii<3>1937389
Ref: whatsnew/3 3 binascii1937490
Ref: 12931937490
Ref: binascii<3>-Footnote-11937746
Node: bz2<2>1937811
Ref: whatsnew/3 3 bz21937912
Ref: 12941937912
Ref: bz2<2>-Footnote-11938887
Ref: bz2<2>-Footnote-21938951
Node: codecs<2>1939015
Ref: whatsnew/3 3 codecs1939119
Ref: 12971939119
Ref: codecs<2>-Footnote-11940441
Ref: codecs<2>-Footnote-21940506
Ref: codecs<2>-Footnote-31940571
Node: collections<7>1940636
Ref: whatsnew/3 3 collections1940747
Ref: 12981940747
Ref: collections<7>-Footnote-11941515
Ref: collections<7>-Footnote-21941580
Ref: collections<7>-Footnote-31941645
Ref: collections<7>-Footnote-41941710
Node: contextlib<7>1941775
Ref: whatsnew/3 3 contextlib1941885
Ref: 129a1941885
Ref: contextlib<7>-Footnote-11942480
Node: crypt<2>1942545
Ref: whatsnew/3 3 crypt1942650
Ref: 129b1942650
Ref: crypt<2>-Footnote-11942854
Node: curses<6>1942919
Ref: whatsnew/3 3 curses1943022
Ref: 129c1943022
Ref: curses<6>-Footnote-11943834
Node: datetime<7>1943898
Ref: whatsnew/3 3 datetime1944003
Ref: 12a11944003
Ref: datetime<7>-Footnote-11944664
Node: decimal<4>1944729
Ref: whatsnew/3 3 decimal1944833
Ref: 12a31944833
Ref: whatsnew/3 3 new-decimal1944833
Ref: 12421944833
Ref: decimal<4>-Footnote-11946539
Node: Features<2>1946603
Ref: whatsnew/3 3 id11946684
Ref: 12a41946684
Node: API changes<2>1947060
Ref: whatsnew/3 3 id21947141
Ref: 12a71947141
Node: email<6>1950014
Ref: whatsnew/3 3 email1950116
Ref: 12b91950116
Ref: whatsnew/3 3 new-email1950116
Ref: 12431950116
Node: Policy Framework1950247
Ref: whatsnew/3 3 policy-framework1950355
Ref: 12ba1950355
Node: Provisional Policy with New Header API1953273
Ref: whatsnew/3 3 provisional-policy-with-new-header-api1953407
Ref: 12be1953407
Node: Other API Changes1957989
Ref: whatsnew/3 3 other-api-changes1958098
Ref: 12c21958098
Node: ftplib<3>1958947
Ref: whatsnew/3 3 ftplib1959051
Ref: 12c81959051
Ref: ftplib<3>-Footnote-11959964
Ref: ftplib<3>-Footnote-21960028
Ref: ftplib<3>-Footnote-31960093
Node: functools<7>1960158
Ref: whatsnew/3 3 functools1960259
Ref: 12cd1960259
Ref: functools<7>-Footnote-11960607
Node: gc<7>1960672
Ref: whatsnew/3 3 gc1960771
Ref: 12ce1960771
Node: hmac<5>1960946
Ref: whatsnew/3 3 hmac1961040
Ref: 12d01961040
Ref: hmac<5>-Footnote-11961307
Node: http<5>1961372
Ref: whatsnew/3 3 http1961468
Ref: 12d21961468
Ref: http<5>-Footnote-11962154
Ref: http<5>-Footnote-21962218
Ref: http<5>-Footnote-31962283
Node: html<2>1962348
Ref: whatsnew/3 3 html1962447
Ref: 12d91962447
Ref: html<2>-Footnote-11963448
Ref: html<2>-Footnote-21963513
Ref: html<2>-Footnote-31963578
Ref: html<2>-Footnote-41963643
Ref: html<2>-Footnote-51963708
Ref: html<2>-Footnote-61963773
Ref: html<2>-Footnote-71963840
Ref: html<2>-Footnote-81963906
Ref: html<2>-Footnote-91963971
Ref: html<2>-Footnote-101964036
Ref: html<2>-Footnote-111964104
Ref: html<2>-Footnote-121964171
Ref: html<2>-Footnote-131964237
Ref: html<2>-Footnote-141964303
Ref: html<2>-Footnote-151964368
Ref: html<2>-Footnote-161964434
Node: imaplib<4>1964500
Ref: whatsnew/3 3 imaplib1964603
Ref: 12db1964603
Ref: imaplib<4>-Footnote-11964845
Node: inspect<10>1964909
Ref: whatsnew/3 3 inspect1965010
Ref: 12dc1965010
Ref: inspect<10>-Footnote-11965724
Ref: inspect<10>-Footnote-21965789
Node: io<8>1965854
Ref: whatsnew/3 3 io1965957
Ref: 12df1965957
Ref: io<8>-Footnote-11966607
Node: itertools<7>1966672
Ref: whatsnew/3 3 itertools1966774
Ref: 12e01966774
Node: logging<7>1966932
Ref: whatsnew/3 3 logging1967036
Ref: 12e11967036
Node: math<9>1967489
Ref: whatsnew/3 3 math1967588
Ref: 12e21967588
Ref: math<9>-Footnote-11967814
Node: mmap<4>1967879
Ref: whatsnew/3 3 mmap1967986
Ref: 12e41967986
Ref: mmap<4>-Footnote-11968324
Node: multiprocessing<9>1968389
Ref: whatsnew/3 3 multiprocessing1968499
Ref: 12e61968499
Ref: multiprocessing<9>-Footnote-11969676
Ref: multiprocessing<9>-Footnote-21969741
Ref: multiprocessing<9>-Footnote-31969805
Ref: multiprocessing<9>-Footnote-41969869
Node: nntplib<2>1969934
Ref: whatsnew/3 3 nntplib1970043
Ref: 12ef1970043
Ref: nntplib<2>-Footnote-11970603
Node: os<13>1970667
Ref: whatsnew/3 3 os1970764
Ref: 12f01970764
Ref: os<13>-Footnote-11978222
Ref: os<13>-Footnote-21978287
Ref: os<13>-Footnote-31978351
Ref: os<13>-Footnote-41978416
Ref: os<13>-Footnote-51978481
Ref: os<13>-Footnote-61978546
Ref: os<13>-Footnote-71978610
Ref: os<13>-Footnote-81978675
Ref: os<13>-Footnote-91978740
Ref: os<13>-Footnote-101978805
Ref: os<13>-Footnote-111978870
Node: pdb<9>1978936
Ref: whatsnew/3 3 pdb1979032
Ref: 13281979032
Ref: pdb<9>-Footnote-11979315
Node: pickle<6>1979380
Ref: whatsnew/3 3 pickle1979478
Ref: 13291979478
Ref: pickle<6>-Footnote-11979749
Node: pydoc<6>1979814
Ref: whatsnew/3 3 pydoc1979912
Ref: 132b1979912
Node: re<10>1980111
Ref: whatsnew/3 3 re1980205
Ref: 132c1980205
Ref: re<10>-Footnote-11980401
Node: sched1980465
Ref: whatsnew/3 3 sched1980560
Ref: 132d1980560
Ref: sched-Footnote-11981707
Ref: sched-Footnote-21981772
Ref: sched-Footnote-31981836
Ref: sched-Footnote-41981901
Ref: sched-Footnote-51981966
Node: select<2>1982031
Ref: whatsnew/3 3 select1982128
Ref: 13321982128
Ref: select<2>-Footnote-11982394
Node: shlex<3>1982458
Ref: whatsnew/3 3 shlex1982559
Ref: 13331982559
Node: shutil<7>1982866
Ref: whatsnew/3 3 shutil1982967
Ref: 13341982967
Ref: shutil<7>-Footnote-11984841
Ref: shutil<7>-Footnote-21984906
Ref: shutil<7>-Footnote-31984971
Ref: shutil<7>-Footnote-41985036
Ref: shutil<7>-Footnote-51985101
Ref: shutil<7>-Footnote-61985166
Ref: shutil<7>-Footnote-71985231
Ref: shutil<7>-Footnote-81985295
Node: signal<4>1985359
Ref: whatsnew/3 3 signal1985460
Ref: 13371985460
Ref: signal<4>-Footnote-11986533
Node: smtpd<4>1986597
Ref: whatsnew/3 3 smtpd1986699
Ref: 133e1986699
Ref: smtpd<4>-Footnote-11987182
Ref: smtpd<4>-Footnote-21987241
Ref: smtpd<4>-Footnote-31987300
Node: smtplib<4>1987364
Ref: whatsnew/3 3 smtplib1987467
Ref: 133f1987467
Ref: smtplib<4>-Footnote-11988221
Ref: smtplib<4>-Footnote-21988286
Ref: smtplib<4>-Footnote-31988351
Node: socket<11>1988415
Ref: whatsnew/3 3 socket1988525
Ref: 13411988525
Ref: socket<11>-Footnote-11989767
Ref: socket<11>-Footnote-21989831
Ref: socket<11>-Footnote-31989896
Ref: socket<11>-Footnote-41989985
Ref: socket<11>-Footnote-51990050
Node: socketserver<3>1990115
Ref: whatsnew/3 3 socketserver1990226
Ref: 13441990226
Ref: socketserver<3>-Footnote-11990604
Node: sqlite3<11>1990669
Ref: whatsnew/3 3 sqlite31990777
Ref: 13481990777
Ref: sqlite3<11>-Footnote-11991054
Node: ssl<12>1991119
Ref: whatsnew/3 3 ssl1991219
Ref: 13491991219
Ref: ssl<12>-Footnote-11993440
Ref: ssl<12>-Footnote-21993505
Ref: ssl<12>-Footnote-31993570
Ref: ssl<12>-Footnote-41993635
Ref: ssl<12>-Footnote-51993700
Ref: ssl<12>-Footnote-61993765
Ref: ssl<12>-Footnote-71993830
Ref: ssl<12>-Footnote-81993895
Ref: ssl<12>-Footnote-91993960
Ref: ssl<12>-Footnote-101994025
Ref: ssl<12>-Footnote-111994091
Node: stat<2>1994157
Ref: whatsnew/3 3 stat1994255
Ref: 13521994255
Ref: stat<2>-Footnote-11994553
Node: struct<4>1994618
Ref: whatsnew/3 3 struct1994722
Ref: 13541994722
Ref: struct<4>-Footnote-11994971
Node: subprocess<6>1995035
Ref: whatsnew/3 3 subprocess1995139
Ref: 13551995139
Ref: subprocess<6>-Footnote-11995477
Ref: subprocess<6>-Footnote-21995541
Node: sys<13>1995605
Ref: whatsnew/3 3 sys1995710
Ref: 13571995710
Ref: sys<13>-Footnote-11995931
Node: tarfile<9>1995996
Ref: whatsnew/3 3 tarfile1996099
Ref: 13591996099
Ref: tarfile<9>-Footnote-11996308
Node: tempfile<4>1996372
Ref: whatsnew/3 3 tempfile1996479
Ref: 135a1996479
Ref: tempfile<4>-Footnote-11996706
Node: textwrap<3>1996770
Ref: whatsnew/3 3 textwrap1996879
Ref: 135b1996879
Ref: textwrap<3>-Footnote-11997125
Node: threading<9>1997190
Ref: whatsnew/3 3 threading1997295
Ref: 135c1997295
Ref: threading<9>-Footnote-11998234
Ref: threading<9>-Footnote-21998299
Node: time<8>1998363
Ref: whatsnew/3 3 time1998465
Ref: 13631998465
Ref: time<8>-Footnote-11999437
Ref: time<8>-Footnote-21999479
Node: types<8>1999544
Ref: whatsnew/3 3 types1999646
Ref: 13681999646
Ref: types<8>-Footnote-11999986
Ref: types<8>-Footnote-22000051
Ref: types<8>-Footnote-32000093
Node: unittest<11>2000158
Ref: whatsnew/3 3 unittest2000262
Ref: 136b2000262
Ref: unittest<11>-Footnote-12000681
Node: urllib<6>2000746
Ref: whatsnew/3 3 urllib2000855
Ref: 13702000855
Ref: urllib<6>-Footnote-12001211
Node: webbrowser<4>2001278
Ref: whatsnew/3 3 webbrowser2001399
Ref: 13722001399
Ref: webbrowser<4>-Footnote-12001941
Ref: webbrowser<4>-Footnote-22002006
Node: xml etree ElementTree<2>2002071
Ref: whatsnew/3 3 xml-etree-elementtree2002190
Ref: 13732002190
Node: zlib<3>2002711
Ref: whatsnew/3 3 zlib2002808
Ref: 13742002808
Ref: zlib<3>-Footnote-12003284
Ref: zlib<3>-Footnote-22003349
Node: Optimizations<10>2003414
Ref: whatsnew/3 3 optimizations2003558
Ref: 13772003558
Ref: Optimizations<10>-Footnote-12004371
Ref: Optimizations<10>-Footnote-22004413
Ref: Optimizations<10>-Footnote-32004478
Ref: Optimizations<10>-Footnote-42004543
Node: Build and C API Changes<4>2004608
Ref: whatsnew/3 3 build-and-c-api-changes2004746
Ref: 124b2004746
Ref: Build and C API Changes<4>-Footnote-12006637
Ref: Build and C API Changes<4>-Footnote-22006679
Ref: Build and C API Changes<4>-Footnote-32006721
Node: Deprecated<11>2006786
Ref: whatsnew/3 3 deprecated2006928
Ref: 138d2006928
Node: Unsupported Operating Systems<2>2007267
Ref: whatsnew/3 3 unsupported-operating-systems2007409
Ref: 138e2007409
Node: Deprecated Python modules functions and methods<4>2007765
Ref: whatsnew/3 3 deprecated-python-modules-functions-and-methods2007962
Ref: 138f2007962
Ref: Deprecated Python modules functions and methods<4>-Footnote-12010314
Ref: Deprecated Python modules functions and methods<4>-Footnote-22010378
Ref: Deprecated Python modules functions and methods<4>-Footnote-32010420
Ref: Deprecated Python modules functions and methods<4>-Footnote-42010485
Ref: Deprecated Python modules functions and methods<4>-Footnote-52010550
Node: Deprecated functions and types of the C API<3>2010615
Ref: whatsnew/3 3 deprecated-functions-and-types-of-the-c-api2010799
Ref: 13932010799
Ref: Deprecated functions and types of the C API<3>-Footnote-12013825
Node: Deprecated features2013867
Ref: whatsnew/3 3 deprecated-features2013992
Ref: 139d2013992
Node: Porting to Python 3 32014217
Ref: whatsnew/3 3 porting-to-python-3-32014324
Ref: 139e2014324
Node: Porting Python code2014603
Ref: whatsnew/3 3 porting-python-code2014703
Ref: 12702014703
Ref: whatsnew/3 3 portingpythoncode2014703
Ref: 139f2014703
Ref: Porting Python code-Footnote-12021748
Ref: Porting Python code-Footnote-22021813
Ref: Porting Python code-Footnote-32021878
Ref: Porting Python code-Footnote-42021943
Ref: Porting Python code-Footnote-52021985
Ref: Porting Python code-Footnote-62022027
Ref: Porting Python code-Footnote-72022091
Ref: Porting Python code-Footnote-82022158
Ref: Porting Python code-Footnote-92022223
Ref: Porting Python code-Footnote-102022287
Node: Porting C code2022353
Ref: whatsnew/3 3 porting-c-code2022483
Ref: 124c2022483
Ref: Porting C code-Footnote-12023984
Node: Building C extensions2024026
Ref: whatsnew/3 3 building-c-extensions2024164
Ref: 13ae2024164
Ref: Building C extensions-Footnote-12024764
Node: Command Line Switch Changes2024829
Ref: whatsnew/3 3 command-line-switch-changes2024944
Ref: 13af2024944
Ref: Command Line Switch Changes-Footnote-12025512
Ref: Command Line Switch Changes-Footnote-22025577
Node: What’s New In Python 3 22025642
Ref: whatsnew/3 2 doc2025792
Ref: 13b12025792
Ref: whatsnew/3 2 translation-repo2025792
Ref: 13b22025792
Ref: whatsnew/3 2 what-s-new-in-python-3-22025792
Ref: 13b32025792
Ref: What’s New In Python 3 2-Footnote-12027195
Ref: What’s New In Python 3 2-Footnote-22027294
Node: PEP 384 Defining a Stable ABI2027336
Ref: whatsnew/3 2 pep-384-defining-a-stable-abi2027481
Ref: 13b42027481
Ref: PEP 384 Defining a Stable ABI-Footnote-12028578
Node: PEP 389 Argparse Command Line Parsing Module2028620
Ref: whatsnew/3 2 pep-389-argparse-command-line-parsing-module2028824
Ref: 13b52028824
Ref: PEP 389 Argparse Command Line Parsing Module-Footnote-12032969
Node: PEP 391 Dictionary Based Configuration for Logging2033011
Ref: whatsnew/3 2 pep-391-dictionary-based-configuration-for-logging2033224
Ref: 13b72033224
Ref: PEP 391 Dictionary Based Configuration for Logging-Footnote-12035527
Node: PEP 3148 The concurrent futures module2035569
Ref: whatsnew/3 2 pep-3148-the-concurrent-futures-module2035773
Ref: 13b92035773
Ref: PEP 3148 The concurrent futures module-Footnote-12038481
Node: PEP 3147 PYC Repository Directories2038523
Ref: whatsnew/3 2 pep-3147-pyc-repository-directories2038713
Ref: 13bd2038713
Ref: PEP 3147 PYC Repository Directories-Footnote-12041772
Node: PEP 3149 ABI Version Tagged so Files2041814
Ref: whatsnew/3 2 pep-3149-abi-version-tagged-so-files2042017
Ref: 13bf2042017
Ref: PEP 3149 ABI Version Tagged so Files-Footnote-12043271
Node: PEP 3333 Python Web Server Gateway Interface v1 0 12043313
Ref: whatsnew/3 2 pep-3333-python-web-server-gateway-interface-v1-0-12043507
Ref: 13c02043507
Ref: PEP 3333 Python Web Server Gateway Interface v1 0 1-Footnote-12045876
Ref: PEP 3333 Python Web Server Gateway Interface v1 0 1-Footnote-22045935
Ref: PEP 3333 Python Web Server Gateway Interface v1 0 1-Footnote-32045994
Node: Other Language Changes<11>2046036
Ref: whatsnew/3 2 other-language-changes2046229
Ref: 13c22046229
Ref: Other Language Changes<11>-Footnote-12055769
Ref: Other Language Changes<11>-Footnote-22055833
Ref: Other Language Changes<11>-Footnote-32055897
Ref: Other Language Changes<11>-Footnote-42055964
Ref: Other Language Changes<11>-Footnote-52056028
Ref: Other Language Changes<11>-Footnote-62056092
Ref: Other Language Changes<11>-Footnote-72056156
Ref: Other Language Changes<11>-Footnote-82056220
Ref: Other Language Changes<11>-Footnote-92056284
Ref: Other Language Changes<11>-Footnote-102056348
Ref: Other Language Changes<11>-Footnote-112056414
Ref: Other Language Changes<11>-Footnote-122056481
Ref: Other Language Changes<11>-Footnote-132056546
Ref: Other Language Changes<11>-Footnote-142056611
Ref: Other Language Changes<11>-Footnote-152056677
Ref: Other Language Changes<11>-Footnote-162056743
Node: New Improved and Deprecated Modules2056808
Ref: whatsnew/3 2 new-improved-and-deprecated-modules2056965
Ref: 13cf2056965
Node: email<7>2058998
Ref: whatsnew/3 2 email2059098
Ref: 13d02059098
Ref: email<7>-Footnote-12061083
Ref: email<7>-Footnote-22061142
Ref: email<7>-Footnote-32061206
Node: elementtree2061271
Ref: whatsnew/3 2 elementtree2061392
Ref: 13d82061392
Ref: elementtree-Footnote-12062879
Ref: elementtree-Footnote-22062979
Node: functools<8>2063043
Ref: whatsnew/3 2 functools2063168
Ref: 13df2063168
Ref: functools<8>-Footnote-12066644
Ref: functools<8>-Footnote-22066727
Ref: functools<8>-Footnote-32066806
Ref: functools<8>-Footnote-42066871
Ref: functools<8>-Footnote-52066936
Ref: functools<8>-Footnote-62067000
Ref: functools<8>-Footnote-72067064
Ref: functools<8>-Footnote-82067128
Node: itertools<8>2067180
Ref: whatsnew/3 2 itertools2067308
Ref: 13e32067308
Node: collections<8>2068001
Ref: whatsnew/3 2 collections2068130
Ref: 13e52068130
Ref: collections<8>-Footnote-12070379
Ref: collections<8>-Footnote-22070439
Node: threading<10>2070486
Ref: whatsnew/3 2 threading2070620
Ref: 13ea2070620
Ref: threading<10>-Footnote-12073386
Ref: threading<10>-Footnote-22073447
Ref: threading<10>-Footnote-32073546
Ref: threading<10>-Footnote-42073618
Node: datetime and time2073682
Ref: whatsnew/3 2 datetime-and-time2073810
Ref: 13ee2073810
Ref: datetime and time-Footnote-12076604
Ref: datetime and time-Footnote-22076671
Ref: datetime and time-Footnote-32076735
Ref: datetime and time-Footnote-42076799
Ref: datetime and time-Footnote-52076863
Ref: datetime and time-Footnote-62076930
Ref: datetime and time-Footnote-72076994
Node: math<10>2077059
Ref: whatsnew/3 2 math2077180
Ref: 13f22077180
Ref: math<10>-Footnote-12079063
Node: abc<3>2079116
Ref: whatsnew/3 2 abc2079225
Ref: 13f72079225
Ref: abc<3>-Footnote-12079852
Node: io<9>2079916
Ref: whatsnew/3 2 io2080024
Ref: 13f82080024
Ref: io<9>-Footnote-12081193
Node: reprlib2081257
Ref: whatsnew/3 2 reprlib2081369
Ref: 13fa2081369
Ref: reprlib-Footnote-12082352
Ref: reprlib-Footnote-22082416
Node: logging<8>2082480
Ref: whatsnew/3 2 logging2082593
Ref: 13fc2082593
Node: csv<4>2084452
Ref: whatsnew/3 2 csv2084571
Ref: 14042084571
Ref: csv<4>-Footnote-12085437
Ref: csv<4>-Footnote-22085501
Node: contextlib<8>2085568
Ref: whatsnew/3 2 contextlib2085698
Ref: 14082085698
Ref: contextlib<8>-Footnote-12087916
Node: decimal and fractions2087980
Ref: whatsnew/3 2 decimal-and-fractions2088107
Ref: 140b2088107
Ref: decimal and fractions-Footnote-12090541
Ref: decimal and fractions-Footnote-22090605
Ref: decimal and fractions-Footnote-32090669
Ref: decimal and fractions-Footnote-42090733
Ref: decimal and fractions-Footnote-52090797
Ref: decimal and fractions-Footnote-62090861
Node: ftp2090925
Ref: whatsnew/3 2 ftp2091044
Ref: 140f2091044
Ref: ftp-Footnote-12092389
Ref: ftp-Footnote-22092453
Ref: ftp-Footnote-32092517
Ref: ftp-Footnote-42092581
Node: popen2092645
Ref: whatsnew/3 2 popen2092752
Ref: 14102092752
Ref: popen-Footnote-12093059
Ref: popen-Footnote-22093123
Node: select<3>2093188
Ref: whatsnew/3 2 select2093308
Ref: 14112093308
Ref: select<3>-Footnote-12093742
Node: gzip and zipfile2093806
Ref: whatsnew/3 2 gzip-and-zipfile2093932
Ref: 14132093932
Ref: gzip and zipfile-Footnote-12095499
Ref: gzip and zipfile-Footnote-22095563
Ref: gzip and zipfile-Footnote-32095627
Ref: gzip and zipfile-Footnote-42095694
Ref: gzip and zipfile-Footnote-52095758
Ref: gzip and zipfile-Footnote-62095822
Node: tarfile<10>2095886
Ref: whatsnew/3 2 tarfile2096013
Ref: 14172096013
Ref: tarfile<10>-Footnote-12097589
Node: hashlib<7>2097653
Ref: whatsnew/3 2 hashlib2097770
Ref: 141a2097770
Ref: hashlib<7>-Footnote-12098527
Node: ast<7>2098591
Ref: whatsnew/3 2 ast2098703
Ref: 141b2098703
Node: os<14>2099642
Ref: whatsnew/3 2 os2099753
Ref: 141c2099753
Node: shutil<8>2100526
Ref: whatsnew/3 2 shutil2100642
Ref: 141f2100642
Node: sqlite3<12>2102812
Ref: whatsnew/3 2 sqlite32102929
Ref: 14212102929
Ref: sqlite3<12>-Footnote-12103578
Node: html<3>2103642
Ref: whatsnew/3 2 html2103760
Ref: 14222103760
Node: socket<12>2104049
Ref: whatsnew/3 2 socket2104163
Ref: 14232104163
Ref: socket<12>-Footnote-12104809
Ref: socket<12>-Footnote-22104873
Node: ssl<13>2104937
Ref: whatsnew/3 2 ssl2105048
Ref: 14252105048
Ref: ssl<13>-Footnote-12107146
Ref: ssl<13>-Footnote-22107205
Ref: ssl<13>-Footnote-32107277
Ref: ssl<13>-Footnote-42107341
Ref: ssl<13>-Footnote-52107405
Ref: ssl<13>-Footnote-62107469
Ref: ssl<13>-Footnote-72107533
Ref: ssl<13>-Footnote-82107597
Ref: ssl<13>-Footnote-92107661
Node: nntp2107725
Ref: whatsnew/3 2 nntp2107838
Ref: 14292107838
Ref: nntp-Footnote-12108393
Ref: nntp-Footnote-22108457
Node: certificates2108521
Ref: whatsnew/3 2 certificates2108637
Ref: 142a2108637
Ref: certificates-Footnote-12109035
Node: imaplib<5>2109099
Ref: whatsnew/3 2 imaplib2109225
Ref: 142c2109225
Ref: imaplib<5>-Footnote-12109499
Node: http client<4>2109563
Ref: whatsnew/3 2 http-client2109689
Ref: 142e2109689
Ref: http client<4>-Footnote-12111116
Node: unittest<12>2111181
Ref: whatsnew/3 2 unittest2111306
Ref: 14312111306
Ref: unittest<12>-Footnote-12115986
Ref: unittest<12>-Footnote-22116051
Ref: unittest<12>-Footnote-32116115
Node: random<5>2116179
Ref: whatsnew/3 2 random2116299
Ref: 14362116299
Ref: random<5>-Footnote-12116965
Node: poplib<4>2117029
Ref: whatsnew/3 2 poplib2117148
Ref: 14392117148
Ref: poplib<4>-Footnote-12117502
Node: asyncore<2>2117566
Ref: whatsnew/3 2 asyncore2117687
Ref: 143a2117687
Ref: asyncore<2>-Footnote-12118142
Node: tempfile<5>2118206
Ref: whatsnew/3 2 tempfile2118329
Ref: 143b2118329
Ref: tempfile<5>-Footnote-12118738
Node: inspect<11>2118802
Ref: whatsnew/3 2 inspect2118922
Ref: 143d2118922
Ref: inspect<11>-Footnote-12120297
Node: pydoc<7>2120362
Ref: whatsnew/3 2 pydoc2120477
Ref: 143f2120477
Ref: pydoc<7>-Footnote-12120796
Node: dis<6>2120860
Ref: whatsnew/3 2 dis2120970
Ref: 14402120970
Ref: dis<6>-Footnote-12123122
Node: dbm<7>2123186
Ref: whatsnew/3 2 dbm2123297
Ref: 14422123297
Ref: dbm<7>-Footnote-12123486
Node: ctypes<4>2123550
Ref: whatsnew/3 2 ctypes2123662
Ref: 14432123662
Node: site<4>2123781
Ref: whatsnew/3 2 site2123899
Ref: 14452123899
Ref: site<4>-Footnote-12125133
Node: sysconfig<4>2125197
Ref: whatsnew/3 2 sysconfig2125313
Ref: 14492125313
Node: pdb<10>2127540
Ref: whatsnew/3 2 pdb2127664
Ref: 144c2127664
Node: configparser<6>2128575
Ref: whatsnew/3 2 configparser2128702
Ref: 144d2128702
Node: urllib parse<6>2131568
Ref: whatsnew/3 2 urllib-parse2131695
Ref: 144e2131695
Ref: urllib parse<6>-Footnote-12133709
Ref: urllib parse<6>-Footnote-22133752
Ref: urllib parse<6>-Footnote-32133811
Ref: urllib parse<6>-Footnote-42133875
Ref: urllib parse<6>-Footnote-52133939
Node: mailbox2134003
Ref: whatsnew/3 2 mailbox2134125
Ref: 14522134125
Ref: mailbox-Footnote-12135706
Node: turtledemo2135770
Ref: whatsnew/3 2 turtledemo2135868
Ref: 14592135868
Ref: turtledemo-Footnote-12136305
Node: Multi-threading2136370
Ref: whatsnew/3 2 multi-threading2136518
Ref: 145a2136518
Ref: Multi-threading-Footnote-12138160
Ref: Multi-threading-Footnote-22138239
Ref: Multi-threading-Footnote-32138303
Ref: Multi-threading-Footnote-42138369
Node: Optimizations<11>2138433
Ref: whatsnew/3 2 optimizations2138553
Ref: 145c2138553
Ref: Optimizations<11>-Footnote-12142062
Ref: Optimizations<11>-Footnote-22142126
Ref: Optimizations<11>-Footnote-32142190
Ref: Optimizations<11>-Footnote-42142254
Ref: Optimizations<11>-Footnote-52142300
Ref: Optimizations<11>-Footnote-62142364
Ref: Optimizations<11>-Footnote-72142428
Ref: Optimizations<11>-Footnote-82142493
Ref: Optimizations<11>-Footnote-92142557
Ref: Optimizations<11>-Footnote-102142621
Ref: Optimizations<11>-Footnote-112142686
Ref: Optimizations<11>-Footnote-122142751
Ref: Optimizations<11>-Footnote-132142816
Ref: Optimizations<11>-Footnote-142142884
Ref: Optimizations<11>-Footnote-152142949
Ref: Optimizations<11>-Footnote-162143015
Node: Unicode2143080
Ref: whatsnew/3 2 unicode2143191
Ref: 14612143191
Ref: Unicode-Footnote-12143743
Ref: Unicode-Footnote-22143794
Ref: Unicode-Footnote-32143838
Node: Codecs2143910
Ref: whatsnew/3 2 codecs2144017
Ref: 14622144017
Ref: Codecs-Footnote-12144947
Node: Documentation2145014
Ref: whatsnew/3 2 documentation2145118
Ref: 14632145118
Ref: Documentation-Footnote-12146769
Ref: Documentation-Footnote-22146838
Ref: Documentation-Footnote-32146914
Ref: Documentation-Footnote-42146978
Node: IDLE2147042
Ref: whatsnew/3 2 idle2147155
Ref: 14672147155
Ref: IDLE-Footnote-12147541
Ref: IDLE-Footnote-22147605
Node: Code Repository2147669
Ref: whatsnew/3 2 code-repository2147795
Ref: 14682147795
Ref: Code Repository-Footnote-12148404
Ref: Code Repository-Footnote-22148443
Ref: Code Repository-Footnote-32148485
Ref: Code Repository-Footnote-42148539
Node: Build and C API Changes<5>2148583
Ref: whatsnew/3 2 build-and-c-api-changes2148726
Ref: 14692148726
Ref: Build and C API Changes<5>-Footnote-12152874
Ref: Build and C API Changes<5>-Footnote-22152939
Ref: Build and C API Changes<5>-Footnote-32153003
Ref: Build and C API Changes<5>-Footnote-42153067
Ref: Build and C API Changes<5>-Footnote-52153131
Ref: Build and C API Changes<5>-Footnote-62153195
Ref: Build and C API Changes<5>-Footnote-72153259
Ref: Build and C API Changes<5>-Footnote-82153323
Ref: Build and C API Changes<5>-Footnote-92153387
Ref: Build and C API Changes<5>-Footnote-102153451
Ref: Build and C API Changes<5>-Footnote-112153516
Ref: Build and C API Changes<5>-Footnote-122153581
Ref: Build and C API Changes<5>-Footnote-132153646
Ref: Build and C API Changes<5>-Footnote-142153711
Ref: Build and C API Changes<5>-Footnote-152153794
Node: Porting to Python 3 22153895
Ref: whatsnew/3 2 porting-to-python-3-22154014
Ref: 14722154014
Ref: Porting to Python 3 2-Footnote-12160857
Ref: Porting to Python 3 2-Footnote-22160921
Ref: Porting to Python 3 2-Footnote-32160985
Ref: Porting to Python 3 2-Footnote-42161030
Ref: Porting to Python 3 2-Footnote-52161095
Ref: Porting to Python 3 2-Footnote-62161160
Ref: Porting to Python 3 2-Footnote-72161225
Node: What’s New In Python 3 12161289
Ref: whatsnew/3 1 doc2161439
Ref: 14822161439
Ref: whatsnew/3 1 translation-repo2161439
Ref: 14832161439
Ref: whatsnew/3 1 what-s-new-in-python-3-12161439
Ref: 14842161439
Node: PEP 372 Ordered Dictionaries2162111
Ref: whatsnew/3 1 pep-372-ordered-dictionaries2162259
Ref: 14852162259
Ref: PEP 372 Ordered Dictionaries-Footnote-12164771
Ref: PEP 372 Ordered Dictionaries-Footnote-22164799
Node: PEP 378 Format Specifier for Thousands Separator2164841
Ref: whatsnew/3 1 pep-378-format-specifier-for-thousands-separator2165024
Ref: 14862165024
Ref: PEP 378 Format Specifier for Thousands Separator-Footnote-12166269
Node: Other Language Changes<12>2166311
Ref: whatsnew/3 1 other-language-changes2166504
Ref: 14872166504
Ref: Other Language Changes<12>-Footnote-12171305
Ref: Other Language Changes<12>-Footnote-22171372
Ref: Other Language Changes<12>-Footnote-32171436
Ref: Other Language Changes<12>-Footnote-42171500
Ref: Other Language Changes<12>-Footnote-52171564
Ref: Other Language Changes<12>-Footnote-62171609
Ref: Other Language Changes<12>-Footnote-72171673
Node: New Improved and Deprecated Modules<2>2171737
Ref: whatsnew/3 1 new-improved-and-deprecated-modules2171899
Ref: 14882171899
Ref: New Improved and Deprecated Modules<2>-Footnote-12180504
Ref: New Improved and Deprecated Modules<2>-Footnote-22180571
Ref: New Improved and Deprecated Modules<2>-Footnote-32180635
Ref: New Improved and Deprecated Modules<2>-Footnote-42180699
Ref: New Improved and Deprecated Modules<2>-Footnote-52180763
Ref: New Improved and Deprecated Modules<2>-Footnote-62180827
Ref: New Improved and Deprecated Modules<2>-Footnote-72180869
Ref: New Improved and Deprecated Modules<2>-Footnote-82180933
Ref: New Improved and Deprecated Modules<2>-Footnote-92180997
Ref: New Improved and Deprecated Modules<2>-Footnote-102181061
Ref: New Improved and Deprecated Modules<2>-Footnote-112181126
Ref: New Improved and Deprecated Modules<2>-Footnote-122181191
Ref: New Improved and Deprecated Modules<2>-Footnote-132181256
Node: Optimizations<12>2181321
Ref: whatsnew/3 1 optimizations2181464
Ref: 14982181464
Ref: Optimizations<12>-Footnote-12183643
Ref: Optimizations<12>-Footnote-22183685
Ref: Optimizations<12>-Footnote-32183749
Ref: Optimizations<12>-Footnote-42183813
Ref: Optimizations<12>-Footnote-52183877
Ref: Optimizations<12>-Footnote-62183903
Ref: Optimizations<12>-Footnote-72183967
Node: IDLE<2>2184031
Ref: whatsnew/3 1 idle2184162
Ref: 14992184162
Ref: IDLE<2>-Footnote-12184379
Node: Build and C API Changes<6>2184443
Ref: whatsnew/3 1 build-and-c-api-changes2184578
Ref: 149a2184578
Ref: Build and C API Changes<6>-Footnote-12186845
Ref: Build and C API Changes<6>-Footnote-22186909
Ref: Build and C API Changes<6>-Footnote-32186973
Ref: Build and C API Changes<6>-Footnote-42187037
Ref: Build and C API Changes<6>-Footnote-52187101
Node: Porting to Python 3 12187165
Ref: whatsnew/3 1 porting-to-python-3-12187284
Ref: 149e2187284
Node: What’s New In Python 3 02188416
Ref: whatsnew/3 0 doc2188566
Ref: 149f2188566
Ref: whatsnew/3 0 translation-repo2188566
Ref: 14a02188566
Ref: whatsnew/3 0 what-s-new-in-python-3-02188566
Ref: 14a12188566
Node: Common Stumbling Blocks2190420
Ref: whatsnew/3 0 common-stumbling-blocks2190541
Ref: 14a22190541
Node: Print Is A Function2190911
Ref: whatsnew/3 0 print-is-a-function2191035
Ref: 14a32191035
Ref: Print Is A Function-Footnote-12192722
Node: Views And Iterators Instead Of Lists2192764
Ref: whatsnew/3 0 views-and-iterators-instead-of-lists2192917
Ref: 14a42192917
Node: Ordering Comparisons2194759
Ref: whatsnew/3 0 ordering-comparisons2194901
Ref: 14a72194901
Node: Integers2196351
Ref: whatsnew/3 0 integers2196497
Ref: 14a92196497
Ref: Integers-Footnote-12197720
Ref: Integers-Footnote-22197762
Node: Text Vs Data Instead Of Unicode Vs 8-bit2197804
Ref: whatsnew/3 0 text-vs-data-instead-of-unicode-vs-8-bit2197921
Ref: 14aa2197921
Ref: Text Vs Data Instead Of Unicode Vs 8-bit-Footnote-12204516
Ref: Text Vs Data Instead Of Unicode Vs 8-bit-Footnote-22204558
Ref: Text Vs Data Instead Of Unicode Vs 8-bit-Footnote-32204600
Node: Overview Of Syntax Changes2204642
Ref: whatsnew/3 0 overview-of-syntax-changes2204809
Ref: 14ad2204809
Node: New Syntax2205021
Ref: whatsnew/3 0 new-syntax2205117
Ref: 14ae2205117
Ref: New Syntax-Footnote-12207678
Ref: New Syntax-Footnote-22207720
Ref: New Syntax-Footnote-32207762
Ref: New Syntax-Footnote-42207804
Ref: New Syntax-Footnote-52207846
Node: Changed Syntax2207888
Ref: whatsnew/3 0 changed-syntax2208007
Ref: 14b12208007
Ref: Changed Syntax-Footnote-12209686
Ref: Changed Syntax-Footnote-22209728
Ref: Changed Syntax-Footnote-32209770
Ref: Changed Syntax-Footnote-42209812
Node: Removed Syntax2209854
Ref: whatsnew/3 0 removed-syntax2209954
Ref: 14b22209954
Ref: Removed Syntax-Footnote-12211138
Ref: Removed Syntax-Footnote-22211180
Node: Changes Already Present In Python 2 62211222
Ref: whatsnew/3 0 changes-already-present-in-python-2-62211381
Ref: 14b42211381
Node: Library Changes2215250
Ref: whatsnew/3 0 library-changes2215427
Ref: 14c72215427
Ref: Library Changes-Footnote-12221682
Ref: Library Changes-Footnote-22221724
Ref: Library Changes-Footnote-32221766
Ref: Library Changes-Footnote-42221808
Ref: Library Changes-Footnote-52221850
Ref: Library Changes-Footnote-62221892
Node: PEP 3101 A New Approach To String Formatting2221934
Ref: whatsnew/3 0 pep-3101-a-new-approach-to-string-formatting2222095
Ref: 14cc2222095
Ref: PEP 3101 A New Approach To String Formatting-Footnote-12222487
Node: Changes To Exceptions2222529
Ref: whatsnew/3 0 changes-to-exceptions2222702
Ref: 14cd2222702
Ref: Changes To Exceptions-Footnote-12226239
Ref: Changes To Exceptions-Footnote-22226281
Ref: Changes To Exceptions-Footnote-32226323
Ref: Changes To Exceptions-Footnote-42226365
Ref: Changes To Exceptions-Footnote-52226407
Node: Miscellaneous Other Changes2226449
Ref: whatsnew/3 0 miscellaneous-other-changes2226604
Ref: 14d12226604
Node: Operators And Special Methods2226732
Ref: whatsnew/3 0 operators-and-special-methods2226842
Ref: 14d22226842
Ref: Operators And Special Methods-Footnote-12228524
Node: Builtins2228566
Ref: whatsnew/3 0 builtins2228676
Ref: 14de2228676
Ref: Builtins-Footnote-12231153
Ref: Builtins-Footnote-22231195
Node: Build and C API Changes<7>2231237
Ref: whatsnew/3 0 build-and-c-api-changes2231382
Ref: 14e42231382
Ref: Build and C API Changes<7>-Footnote-12232418
Ref: Build and C API Changes<7>-Footnote-22232460
Ref: Build and C API Changes<7>-Footnote-32232502
Node: Performance2232544
Ref: whatsnew/3 0 performance2232683
Ref: 14e62232683
Node: Porting To Python 3 02233004
Ref: whatsnew/3 0 porting-to-python-3-02233108
Ref: 14e72233108
Node: What’s New in Python 2 72234616
Ref: whatsnew/2 7 doc2234766
Ref: 14e92234766
Ref: whatsnew/2 7 translation-repo2234766
Ref: 14ea2234766
Ref: whatsnew/2 7 what-s-new-in-python-2-72234766
Ref: 14eb2234766
Node: The Future for Python 2 x2237229
Ref: whatsnew/2 7 the-future-for-python-2-x2237373
Ref: 14ec2237373
Ref: whatsnew/2 7 whatsnew27-python312237373
Ref: 14ed2237373
Ref: The Future for Python 2 x-Footnote-12240691
Ref: The Future for Python 2 x-Footnote-22240733
Node: Changes to the Handling of Deprecation Warnings2240770
Ref: whatsnew/2 7 changes-to-the-handling-of-deprecation-warnings2240942
Ref: 14ef2240942
Ref: Changes to the Handling of Deprecation Warnings-Footnote-12242517
Node: Python 3 1 Features2242581
Ref: whatsnew/2 7 python-3-1-features2242779
Ref: 14f02242779
Node: PEP 372 Adding an Ordered Dictionary to collections2244704
Ref: whatsnew/2 7 pep-03722244906
Ref: 14f12244906
Ref: whatsnew/2 7 pep-372-adding-an-ordered-dictionary-to-collections2244906
Ref: 14f42244906
Ref: PEP 372 Adding an Ordered Dictionary to collections-Footnote-12248522
Ref: PEP 372 Adding an Ordered Dictionary to collections-Footnote-22248550
Node: PEP 378 Format Specifier for Thousands Separator<2>2248592
Ref: whatsnew/2 7 pep-03782248828
Ref: 14f22248828
Ref: whatsnew/2 7 pep-378-format-specifier-for-thousands-separator2248828
Ref: 14f62248828
Ref: PEP 378 Format Specifier for Thousands Separator<2>-Footnote-12250345
Node: PEP 389 The argparse Module for Parsing Command Lines2250387
Ref: whatsnew/2 7 pep-389-the-argparse-module-for-parsing-command-lines2250622
Ref: 14f72250622
Ref: PEP 389 The argparse Module for Parsing Command Lines-Footnote-12254663
Node: PEP 391 Dictionary-Based Configuration For Logging2254705
Ref: whatsnew/2 7 pep-391-dictionary-based-configuration-for-logging2254914
Ref: 14f82254914
Ref: PEP 391 Dictionary-Based Configuration For Logging-Footnote-12258811
Node: PEP 3106 Dictionary Views2258853
Ref: whatsnew/2 7 pep-3106-dictionary-views2259039
Ref: 14ff2259039
Ref: PEP 3106 Dictionary Views-Footnote-12261160
Ref: PEP 3106 Dictionary Views-Footnote-22261202
Node: PEP 3137 The memoryview Object2261266
Ref: whatsnew/2 7 pep-3137-the-memoryview-object2261428
Ref: 15002261428
Ref: PEP 3137 The memoryview Object-Footnote-12263097
Ref: PEP 3137 The memoryview Object-Footnote-22263139
Node: Other Language Changes<13>2263203
Ref: whatsnew/2 7 other-language-changes2263364
Ref: 15012263364
Ref: Other Language Changes<13>-Footnote-12273339
Ref: Other Language Changes<13>-Footnote-22273403
Ref: Other Language Changes<13>-Footnote-32273467
Ref: Other Language Changes<13>-Footnote-42273531
Ref: Other Language Changes<13>-Footnote-52273595
Ref: Other Language Changes<13>-Footnote-62273659
Ref: Other Language Changes<13>-Footnote-72273723
Ref: Other Language Changes<13>-Footnote-82273787
Ref: Other Language Changes<13>-Footnote-92273851
Ref: Other Language Changes<13>-Footnote-102273915
Ref: Other Language Changes<13>-Footnote-112273980
Ref: Other Language Changes<13>-Footnote-122274045
Ref: Other Language Changes<13>-Footnote-132274110
Ref: Other Language Changes<13>-Footnote-142274175
Ref: Other Language Changes<13>-Footnote-152274243
Ref: Other Language Changes<13>-Footnote-162274308
Ref: Other Language Changes<13>-Footnote-172274373
Ref: Other Language Changes<13>-Footnote-182274438
Ref: Other Language Changes<13>-Footnote-192274506
Ref: Other Language Changes<13>-Footnote-202274571
Ref: Other Language Changes<13>-Footnote-212274636
Ref: Other Language Changes<13>-Footnote-222274701
Ref: Other Language Changes<13>-Footnote-232274766
Ref: Other Language Changes<13>-Footnote-242274831
Node: Interpreter Changes2274896
Ref: whatsnew/2 7 interpreter-changes2275004
Ref: 15052275004
Ref: whatsnew/2 7 new-27-interpreter2275004
Ref: 15062275004
Ref: Interpreter Changes-Footnote-12275663
Node: Optimizations<13>2275727
Ref: whatsnew/2 7 optimizations2275835
Ref: 15072275835
Ref: Optimizations<13>-Footnote-12280722
Ref: Optimizations<13>-Footnote-22280786
Ref: Optimizations<13>-Footnote-32280850
Ref: Optimizations<13>-Footnote-42280914
Ref: Optimizations<13>-Footnote-52280978
Ref: Optimizations<13>-Footnote-62281042
Ref: Optimizations<13>-Footnote-72281109
Ref: Optimizations<13>-Footnote-82281173
Ref: Optimizations<13>-Footnote-92281237
Ref: Optimizations<13>-Footnote-102281301
Ref: Optimizations<13>-Footnote-112281366
Ref: Optimizations<13>-Footnote-122281431
Ref: Optimizations<13>-Footnote-132281496
Node: New and Improved Modules2281561
Ref: whatsnew/2 7 new-and-improved-modules2281718
Ref: 15092281718
Ref: New and Improved Modules-Footnote-12317154
Ref: New and Improved Modules-Footnote-22317218
Ref: New and Improved Modules-Footnote-32317282
Ref: New and Improved Modules-Footnote-42317335
Ref: New and Improved Modules-Footnote-52317399
Ref: New and Improved Modules-Footnote-62317463
Ref: New and Improved Modules-Footnote-72317530
Ref: New and Improved Modules-Footnote-82317594
Ref: New and Improved Modules-Footnote-92317658
Ref: New and Improved Modules-Footnote-102317722
Ref: New and Improved Modules-Footnote-112317787
Ref: New and Improved Modules-Footnote-122317852
Ref: New and Improved Modules-Footnote-132317917
Ref: New and Improved Modules-Footnote-142317957
Ref: New and Improved Modules-Footnote-152318022
Ref: New and Improved Modules-Footnote-162318087
Ref: New and Improved Modules-Footnote-172318152
Ref: New and Improved Modules-Footnote-182318217
Ref: New and Improved Modules-Footnote-192318282
Ref: New and Improved Modules-Footnote-202318347
Ref: New and Improved Modules-Footnote-212318412
Ref: New and Improved Modules-Footnote-222318477
Ref: New and Improved Modules-Footnote-232318542
Ref: New and Improved Modules-Footnote-242318607
Ref: New and Improved Modules-Footnote-252318672
Ref: New and Improved Modules-Footnote-262318737
Ref: New and Improved Modules-Footnote-272318805
Ref: New and Improved Modules-Footnote-282318870
Ref: New and Improved Modules-Footnote-292318935
Ref: New and Improved Modules-Footnote-302319000
Ref: New and Improved Modules-Footnote-312319065
Ref: New and Improved Modules-Footnote-322319130
Ref: New and Improved Modules-Footnote-332319195
Ref: New and Improved Modules-Footnote-342319260
Ref: New and Improved Modules-Footnote-352319325
Ref: New and Improved Modules-Footnote-362319390
Ref: New and Improved Modules-Footnote-372319455
Ref: New and Improved Modules-Footnote-382319520
Ref: New and Improved Modules-Footnote-392319585
Ref: New and Improved Modules-Footnote-402319650
Ref: New and Improved Modules-Footnote-412319715
Ref: New and Improved Modules-Footnote-422319780
Ref: New and Improved Modules-Footnote-432319845
Ref: New and Improved Modules-Footnote-442319910
Ref: New and Improved Modules-Footnote-452319975
Ref: New and Improved Modules-Footnote-462320040
Ref: New and Improved Modules-Footnote-472320105
Ref: New and Improved Modules-Footnote-482320170
Ref: New and Improved Modules-Footnote-492320238
Ref: New and Improved Modules-Footnote-502320303
Ref: New and Improved Modules-Footnote-512320368
Ref: New and Improved Modules-Footnote-522320433
Ref: New and Improved Modules-Footnote-532320498
Ref: New and Improved Modules-Footnote-542320563
Ref: New and Improved Modules-Footnote-552320628
Ref: New and Improved Modules-Footnote-562320693
Ref: New and Improved Modules-Footnote-572320758
Ref: New and Improved Modules-Footnote-582320823
Ref: New and Improved Modules-Footnote-592320888
Ref: New and Improved Modules-Footnote-602320953
Ref: New and Improved Modules-Footnote-612321018
Ref: New and Improved Modules-Footnote-622321083
Ref: New and Improved Modules-Footnote-632321148
Ref: New and Improved Modules-Footnote-642321213
Ref: New and Improved Modules-Footnote-652321278
Ref: New and Improved Modules-Footnote-662321343
Ref: New and Improved Modules-Footnote-672321408
Ref: New and Improved Modules-Footnote-682321473
Ref: New and Improved Modules-Footnote-692321538
Ref: New and Improved Modules-Footnote-702321584
Ref: New and Improved Modules-Footnote-712321649
Ref: New and Improved Modules-Footnote-722321714
Ref: New and Improved Modules-Footnote-732321768
Ref: New and Improved Modules-Footnote-742321833
Ref: New and Improved Modules-Footnote-752321898
Ref: New and Improved Modules-Footnote-762321963
Ref: New and Improved Modules-Footnote-772322028
Ref: New and Improved Modules-Footnote-782322093
Ref: New and Improved Modules-Footnote-792322161
Ref: New and Improved Modules-Footnote-802322226
Ref: New and Improved Modules-Footnote-812322291
Ref: New and Improved Modules-Footnote-822322356
Ref: New and Improved Modules-Footnote-832322421
Ref: New and Improved Modules-Footnote-842322486
Ref: New and Improved Modules-Footnote-852322551
Ref: New and Improved Modules-Footnote-862322619
Ref: New and Improved Modules-Footnote-872322687
Ref: New and Improved Modules-Footnote-882322752
Ref: New and Improved Modules-Footnote-892322812
Ref: New and Improved Modules-Footnote-902322872
Ref: New and Improved Modules-Footnote-912322937
Ref: New and Improved Modules-Footnote-922323002
Ref: New and Improved Modules-Footnote-932323067
Ref: New and Improved Modules-Footnote-942323132
Ref: New and Improved Modules-Footnote-952323197
Ref: New and Improved Modules-Footnote-962323262
Ref: New and Improved Modules-Footnote-972323327
Node: New module importlib2323392
Ref: whatsnew/2 7 importlib-section2323502
Ref: 14f32323502
Ref: whatsnew/2 7 new-module-importlib2323502
Ref: 15332323502
Node: New module sysconfig2325042
Ref: whatsnew/2 7 new-module-sysconfig2325186
Ref: 15342325186
Node: ttk Themed Widgets for Tk2326513
Ref: whatsnew/2 7 ttk-themed-widgets-for-tk2326660
Ref: 15362326660
Ref: ttk Themed Widgets for Tk-Footnote-12327750
Ref: ttk Themed Widgets for Tk-Footnote-22327814
Node: Updated module unittest2327878
Ref: whatsnew/2 7 unittest-section2328035
Ref: 15372328035
Ref: whatsnew/2 7 updated-module-unittest2328035
Ref: 15382328035
Ref: Updated module unittest-Footnote-12336998
Ref: Updated module unittest-Footnote-22337042
Ref: Updated module unittest-Footnote-32337069
Ref: Updated module unittest-Footnote-42337106
Ref: Updated module unittest-Footnote-52337170
Ref: Updated module unittest-Footnote-62337234
Ref: Updated module unittest-Footnote-72337301
Ref: Updated module unittest-Footnote-82337365
Ref: Updated module unittest-Footnote-92337429
Ref: Updated module unittest-Footnote-102337493
Ref: Updated module unittest-Footnote-112337558
Ref: Updated module unittest-Footnote-122337623
Ref: Updated module unittest-Footnote-132337688
Ref: Updated module unittest-Footnote-142337753
Ref: Updated module unittest-Footnote-152337818
Node: Updated module ElementTree 1 32337883
Ref: whatsnew/2 7 elementtree-section2338006
Ref: 15532338006
Ref: whatsnew/2 7 updated-module-elementtree-1-32338006
Ref: 15542338006
Ref: Updated module ElementTree 1 3-Footnote-12342027
Node: Build and C API Changes<8>2342091
Ref: whatsnew/2 7 build-and-c-api-changes2342245
Ref: 15572342245
Ref: Build and C API Changes<8>-Footnote-12350939
Ref: Build and C API Changes<8>-Footnote-22351052
Ref: Build and C API Changes<8>-Footnote-32351116
Ref: Build and C API Changes<8>-Footnote-42351180
Ref: Build and C API Changes<8>-Footnote-52351244
Ref: Build and C API Changes<8>-Footnote-62351308
Ref: Build and C API Changes<8>-Footnote-72351372
Ref: Build and C API Changes<8>-Footnote-82351436
Ref: Build and C API Changes<8>-Footnote-92351491
Ref: Build and C API Changes<8>-Footnote-102351555
Ref: Build and C API Changes<8>-Footnote-112351620
Ref: Build and C API Changes<8>-Footnote-122351685
Ref: Build and C API Changes<8>-Footnote-132351750
Ref: Build and C API Changes<8>-Footnote-142351818
Ref: Build and C API Changes<8>-Footnote-152351886
Ref: Build and C API Changes<8>-Footnote-162351951
Ref: Build and C API Changes<8>-Footnote-172352016
Ref: Build and C API Changes<8>-Footnote-182352081
Ref: Build and C API Changes<8>-Footnote-192352146
Ref: Build and C API Changes<8>-Footnote-202352211
Ref: Build and C API Changes<8>-Footnote-212352279
Ref: Build and C API Changes<8>-Footnote-222352344
Node: Capsules2352409
Ref: whatsnew/2 7 capsules2352518
Ref: 15622352518
Ref: whatsnew/2 7 whatsnew27-capsules2352518
Ref: 15632352518
Ref: Capsules-Footnote-12354522
Node: Port-Specific Changes Windows2354586
Ref: whatsnew/2 7 port-specific-changes-windows2354734
Ref: 15662354734
Ref: Port-Specific Changes Windows-Footnote-12356530
Ref: Port-Specific Changes Windows-Footnote-22356594
Ref: Port-Specific Changes Windows-Footnote-32356658
Ref: Port-Specific Changes Windows-Footnote-42356722
Ref: Port-Specific Changes Windows-Footnote-52356789
Ref: Port-Specific Changes Windows-Footnote-62356853
Node: Port-Specific Changes Mac OS X2356917
Ref: whatsnew/2 7 port-specific-changes-mac-os-x2357086
Ref: 15722357086
Ref: Port-Specific Changes Mac OS X-Footnote-12358082
Ref: Port-Specific Changes Mac OS X-Footnote-22358146
Node: Port-Specific Changes FreeBSD2358211
Ref: whatsnew/2 7 port-specific-changes-freebsd2358342
Ref: 15732358342
Ref: Port-Specific Changes FreeBSD-Footnote-12358747
Node: Other Changes and Fixes2358811
Ref: whatsnew/2 7 other-changes-and-fixes2358962
Ref: 15742358962
Ref: Other Changes and Fixes-Footnote-12361157
Ref: Other Changes and Fixes-Footnote-22361221
Ref: Other Changes and Fixes-Footnote-32361288
Ref: Other Changes and Fixes-Footnote-42361352
Ref: Other Changes and Fixes-Footnote-52361416
Node: Porting to Python 2 72361480
Ref: whatsnew/2 7 porting-to-python-2-72361658
Ref: 15762361658
Ref: Porting to Python 2 7-Footnote-12367217
Ref: Porting to Python 2 7-Footnote-22367281
Ref: Porting to Python 2 7-Footnote-32367345
Ref: Porting to Python 2 7-Footnote-42367409
Ref: Porting to Python 2 7-Footnote-52367473
Ref: Porting to Python 2 7-Footnote-62367537
Ref: Porting to Python 2 7-Footnote-72367601
Ref: Porting to Python 2 7-Footnote-82367665
Ref: Porting to Python 2 7-Footnote-92367729
Ref: Porting to Python 2 7-Footnote-102367793
Ref: Porting to Python 2 7-Footnote-112367858
Ref: Porting to Python 2 7-Footnote-122367923
Ref: Porting to Python 2 7-Footnote-132367988
Ref: Porting to Python 2 7-Footnote-142368048
Node: New Features Added to Python 2 7 Maintenance Releases2368113
Ref: whatsnew/2 7 new-features-added-to-python-2-7-maintenance-releases2368284
Ref: 15772368284
Ref: whatsnew/2 7 py27-maintenance-enhancements2368284
Ref: 14ee2368284
Node: Two new environment variables for debug mode2369749
Ref: whatsnew/2 7 two-new-environment-variables-for-debug-mode2369943
Ref: 15782369943
Ref: Two new environment variables for debug mode-Footnote-12370624
Ref: Two new environment variables for debug mode-Footnote-22370689
Node: PEP 434 IDLE Enhancement Exception for All Branches2370754
Ref: whatsnew/2 7 pep-434-idle-enhancement-exception-for-all-branches2371009
Ref: 15792371009
Ref: PEP 434 IDLE Enhancement Exception for All Branches-Footnote-12371529
Node: PEP 466 Network Security Enhancements for Python 2 72371571
Ref: whatsnew/2 7 pep-466-network-security-enhancements-for-python-2-72371830
Ref: 157a2371830
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-12374065
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-22374107
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-32374149
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-42374214
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-52374279
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-62374321
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-72374386
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-82374451
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-92374506
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-102374548
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-112374614
Ref: PEP 466 Network Security Enhancements for Python 2 7-Footnote-122374680
Node: PEP 477 Backport ensurepip PEP 453 to Python 2 72374746
Ref: whatsnew/2 7 pep-477-backport-ensurepip-pep-453-to-python-2-72375033
Ref: 157d2375033
Ref: PEP 477 Backport ensurepip PEP 453 to Python 2 7-Footnote-12375529
Ref: PEP 477 Backport ensurepip PEP 453 to Python 2 7-Footnote-22375571
Node: Bootstrapping pip By Default<2>2375613
Ref: whatsnew/2 7 bootstrapping-pip-by-default2375762
Ref: 157e2375762
Ref: Bootstrapping pip By Default<2>-Footnote-12377431
Ref: Bootstrapping pip By Default<2>-Footnote-22377473
Node: Documentation Changes<2>2377563
Ref: whatsnew/2 7 documentation-changes2377712
Ref: 157f2377712
Ref: Documentation Changes<2>-Footnote-12378657
Ref: Documentation Changes<2>-Footnote-22378694
Node: PEP 476 Enabling certificate verification by default for stdlib http clients<2>2378736
Ref: whatsnew/2 7 pep-476-enabling-certificate-verification-by-default-for-stdlib-http-clients2379028
Ref: 15802379028
Ref: PEP 476 Enabling certificate verification by default for stdlib http clients<2>-Footnote-12380125
Node: PEP 493 HTTPS verification migration tools for Python 2 72380167
Ref: whatsnew/2 7 pep-493-https-verification-migration-tools-for-python-2-72380445
Ref: 15812380445
Ref: PEP 493 HTTPS verification migration tools for Python 2 7-Footnote-12381609
Node: New make regen-all build target<3>2381651
Ref: whatsnew/2 7 new-make-regen-all-build-target2381887
Ref: 15822381887
Ref: New make regen-all build target<3>-Footnote-12382679
Ref: New make regen-all build target<3>-Footnote-22382747
Node: Removal of make touch build target<3>2382812
Ref: whatsnew/2 7 removal-of-make-touch-build-target2382982
Ref: 15832382982
Ref: Removal of make touch build target<3>-Footnote-12383422
Node: Acknowledgements2383487
Ref: whatsnew/2 7 acknowledgements2383628
Ref: 15842383628
Ref: whatsnew/2 7 acks272383628
Ref: 15852383628
Node: What’s New in Python 2 62383901
Ref: whatsnew/2 6 doc2384051
Ref: 15862384051
Ref: whatsnew/2 6 translation-repo2384051
Ref: 15872384051
Ref: whatsnew/2 6 what-s-new-in-python-2-62384051
Ref: 15882384051
Ref: whatsnew/2 6 whats-new-in-2-62384051
Ref: 14b52384051
Ref: What’s New in Python 2 6-Footnote-12387113
Node: Python 3 02387155
Ref: whatsnew/2 6 python-3-02387271
Ref: 15892387271
Ref: Python 3 0-Footnote-12389386
Ref: Python 3 0-Footnote-22389428
Node: Changes to the Development Process2389470
Ref: whatsnew/2 6 changes-to-the-development-process2389627
Ref: 158a2389627
Node: New Issue Tracker Roundup2390145
Ref: whatsnew/2 6 new-issue-tracker-roundup2390304
Ref: 158b2390304
Ref: New Issue Tracker Roundup-Footnote-12392356
Ref: New Issue Tracker Roundup-Footnote-22392405
Ref: New Issue Tracker Roundup-Footnote-32392436
Ref: New Issue Tracker Roundup-Footnote-42392476
Ref: New Issue Tracker Roundup-Footnote-52392511
Node: New Documentation Format reStructuredText Using Sphinx2392549
Ref: whatsnew/2 6 new-documentation-format-restructuredtext-using-sphinx2392708
Ref: 158c2392708
Ref: New Documentation Format reStructuredText Using Sphinx-Footnote-12394828
Ref: New Documentation Format reStructuredText Using Sphinx-Footnote-22394887
Ref: New Documentation Format reStructuredText Using Sphinx-Footnote-32394936
Ref: New Documentation Format reStructuredText Using Sphinx-Footnote-42394972
Node: PEP 343 The “with” statement2395012
Ref: whatsnew/2 6 pep-03432395211
Ref: 14b62395211
Ref: whatsnew/2 6 pep-343-the-with-statement2395211
Ref: 158d2395211
Node: Writing Context Managers2398494
Ref: whatsnew/2 6 new-26-context-managers2398617
Ref: 14b72398617
Ref: whatsnew/2 6 writing-context-managers2398617
Ref: 158f2398617
Node: The contextlib module2403132
Ref: whatsnew/2 6 new-module-contextlib2403255
Ref: 14b82403255
Ref: whatsnew/2 6 the-contextlib-module2403255
Ref: 15902403255
Ref: The contextlib module-Footnote-12405773
Node: PEP 366 Explicit Relative Imports From a Main Module2405815
Ref: whatsnew/2 6 pep-03662406020
Ref: 14b92406020
Ref: whatsnew/2 6 pep-366-explicit-relative-imports-from-a-main-module2406020
Ref: 15922406020
Node: PEP 370 Per-user site-packages Directory2406779
Ref: whatsnew/2 6 pep-03702406987
Ref: 14ba2406987
Ref: whatsnew/2 6 pep-370-per-user-site-packages-directory2406987
Ref: 15942406987
Ref: PEP 370 Per-user site-packages Directory-Footnote-12408453
Node: PEP 371 The multiprocessing Package2408495
Ref: whatsnew/2 6 pep-03712408686
Ref: 14bb2408686
Ref: whatsnew/2 6 pep-371-the-multiprocessing-package2408686
Ref: 15982408686
Ref: PEP 371 The multiprocessing Package-Footnote-12413937
Node: PEP 3101 Advanced String Formatting2413979
Ref: whatsnew/2 6 pep-31012414158
Ref: 14bc2414158
Ref: whatsnew/2 6 pep-3101-advanced-string-formatting2414158
Ref: 15a22414158
Ref: PEP 3101 Advanced String Formatting-Footnote-12419877
Node: PEP 3105 print As a Function2419919
Ref: whatsnew/2 6 pep-31052420098
Ref: 14bd2420098
Ref: whatsnew/2 6 pep-3105-print-as-a-function2420098
Ref: 15a42420098
Ref: PEP 3105 print As a Function-Footnote-12421233
Node: PEP 3110 Exception-Handling Changes2421275
Ref: whatsnew/2 6 pep-31102421441
Ref: 14be2421441
Ref: whatsnew/2 6 pep-3110-exception-handling-changes2421441
Ref: 15a52421441
Ref: PEP 3110 Exception-Handling Changes-Footnote-12423038
Node: PEP 3112 Byte Literals2423080
Ref: whatsnew/2 6 pep-31122423242
Ref: 14bf2423242
Ref: whatsnew/2 6 pep-3112-byte-literals2423242
Ref: 15a62423242
Ref: PEP 3112 Byte Literals-Footnote-12426308
Node: PEP 3116 New I/O Library2426350
Ref: whatsnew/2 6 pep-31162426509
Ref: 14c02426509
Ref: whatsnew/2 6 pep-3116-new-i-o-library2426509
Ref: 15b22426509
Ref: PEP 3116 New I/O Library-Footnote-12430322
Node: PEP 3118 Revised Buffer Protocol2430364
Ref: whatsnew/2 6 pep-31182430531
Ref: 14c12430531
Ref: whatsnew/2 6 pep-3118-revised-buffer-protocol2430531
Ref: 15bc2430531
Ref: PEP 3118 Revised Buffer Protocol-Footnote-12432660
Node: PEP 3119 Abstract Base Classes2432702
Ref: whatsnew/2 6 pep-31192432888
Ref: 14c22432888
Ref: whatsnew/2 6 pep-3119-abstract-base-classes2432888
Ref: 15c02432888
Ref: PEP 3119 Abstract Base Classes-Footnote-12438278
Node: PEP 3127 Integer Literal Support and Syntax2438320
Ref: whatsnew/2 6 pep-31272438499
Ref: 14c32438499
Ref: whatsnew/2 6 pep-3127-integer-literal-support-and-syntax2438499
Ref: 15c22438499
Ref: PEP 3127 Integer Literal Support and Syntax-Footnote-12439854
Node: PEP 3129 Class Decorators2439896
Ref: whatsnew/2 6 pep-31292440082
Ref: 14c42440082
Ref: whatsnew/2 6 pep-3129-class-decorators2440082
Ref: 15c32440082
Ref: PEP 3129 Class Decorators-Footnote-12440486
Node: PEP 3141 A Type Hierarchy for Numbers2440528
Ref: whatsnew/2 6 pep-31412440697
Ref: 14c52440697
Ref: whatsnew/2 6 pep-3141-a-type-hierarchy-for-numbers2440697
Ref: 15c42440697
Ref: PEP 3141 A Type Hierarchy for Numbers-Footnote-12442904
Ref: PEP 3141 A Type Hierarchy for Numbers-Footnote-22442946
Ref: PEP 3141 A Type Hierarchy for Numbers-Footnote-32443044
Node: The fractions Module2443150
Ref: whatsnew/2 6 the-fractions-module2443244
Ref: 15c82443244
Node: Other Language Changes<14>2444851
Ref: whatsnew/2 6 other-language-changes2445022
Ref: 15c92445022
Ref: Other Language Changes<14>-Footnote-12453869
Ref: Other Language Changes<14>-Footnote-22453936
Ref: Other Language Changes<14>-Footnote-32454000
Ref: Other Language Changes<14>-Footnote-42454067
Ref: Other Language Changes<14>-Footnote-52454131
Ref: Other Language Changes<14>-Footnote-62454195
Ref: Other Language Changes<14>-Footnote-72454259
Ref: Other Language Changes<14>-Footnote-82454323
Ref: Other Language Changes<14>-Footnote-92454387
Ref: Other Language Changes<14>-Footnote-102454451
Ref: Other Language Changes<14>-Footnote-112454516
Ref: Other Language Changes<14>-Footnote-122454581
Ref: Other Language Changes<14>-Footnote-132454649
Ref: Other Language Changes<14>-Footnote-142454717
Ref: Other Language Changes<14>-Footnote-152454785
Ref: Other Language Changes<14>-Footnote-162454853
Node: Optimizations<14>2454921
Ref: whatsnew/2 6 optimizations2455032
Ref: 15d12455032
Ref: Optimizations<14>-Footnote-12457889
Ref: Optimizations<14>-Footnote-22457956
Ref: Optimizations<14>-Footnote-32458023
Ref: Optimizations<14>-Footnote-42458087
Node: Interpreter Changes<2>2458151
Ref: whatsnew/2 6 interpreter-changes2458262
Ref: 15d22458262
Ref: whatsnew/2 6 new-26-interpreter2458262
Ref: 15d32458262
Node: New and Improved Modules<2>2459839
Ref: whatsnew/2 6 new-and-improved-modules2459998
Ref: 15d62459998
Ref: New and Improved Modules<2>-Footnote-12502545
Ref: New and Improved Modules<2>-Footnote-22502612
Ref: New and Improved Modules<2>-Footnote-32502665
Ref: New and Improved Modules<2>-Footnote-42502729
Ref: New and Improved Modules<2>-Footnote-52502795
Ref: New and Improved Modules<2>-Footnote-62502859
Ref: New and Improved Modules<2>-Footnote-72502926
Ref: New and Improved Modules<2>-Footnote-82502990
Ref: New and Improved Modules<2>-Footnote-92503044
Ref: New and Improved Modules<2>-Footnote-102503111
Ref: New and Improved Modules<2>-Footnote-112503179
Ref: New and Improved Modules<2>-Footnote-122503247
Ref: New and Improved Modules<2>-Footnote-132503312
Ref: New and Improved Modules<2>-Footnote-142503377
Ref: New and Improved Modules<2>-Footnote-152503444
Ref: New and Improved Modules<2>-Footnote-162503509
Ref: New and Improved Modules<2>-Footnote-172503577
Ref: New and Improved Modules<2>-Footnote-182503642
Ref: New and Improved Modules<2>-Footnote-192503710
Ref: New and Improved Modules<2>-Footnote-202503778
Ref: New and Improved Modules<2>-Footnote-212503846
Ref: New and Improved Modules<2>-Footnote-222503913
Ref: New and Improved Modules<2>-Footnote-232503981
Ref: New and Improved Modules<2>-Footnote-242504049
Ref: New and Improved Modules<2>-Footnote-252504114
Ref: New and Improved Modules<2>-Footnote-262504179
Ref: New and Improved Modules<2>-Footnote-272504247
Ref: New and Improved Modules<2>-Footnote-282504315
Ref: New and Improved Modules<2>-Footnote-292504382
Ref: New and Improved Modules<2>-Footnote-302504447
Ref: New and Improved Modules<2>-Footnote-312504512
Ref: New and Improved Modules<2>-Footnote-322504577
Ref: New and Improved Modules<2>-Footnote-332504642
Ref: New and Improved Modules<2>-Footnote-342504707
Ref: New and Improved Modules<2>-Footnote-352504772
Ref: New and Improved Modules<2>-Footnote-362504837
Ref: New and Improved Modules<2>-Footnote-372504897
Ref: New and Improved Modules<2>-Footnote-382504964
Ref: New and Improved Modules<2>-Footnote-392505024
Ref: New and Improved Modules<2>-Footnote-402505091
Ref: New and Improved Modules<2>-Footnote-412505156
Ref: New and Improved Modules<2>-Footnote-422505223
Ref: New and Improved Modules<2>-Footnote-432505291
Ref: New and Improved Modules<2>-Footnote-442505356
Ref: New and Improved Modules<2>-Footnote-452505421
Ref: New and Improved Modules<2>-Footnote-462505486
Ref: New and Improved Modules<2>-Footnote-472505554
Ref: New and Improved Modules<2>-Footnote-482505619
Ref: New and Improved Modules<2>-Footnote-492505684
Ref: New and Improved Modules<2>-Footnote-502505752
Ref: New and Improved Modules<2>-Footnote-512505817
Ref: New and Improved Modules<2>-Footnote-522505885
Ref: New and Improved Modules<2>-Footnote-532505950
Ref: New and Improved Modules<2>-Footnote-542506018
Ref: New and Improved Modules<2>-Footnote-552506083
Ref: New and Improved Modules<2>-Footnote-562506151
Ref: New and Improved Modules<2>-Footnote-572506216
Ref: New and Improved Modules<2>-Footnote-582506284
Ref: New and Improved Modules<2>-Footnote-592506352
Ref: New and Improved Modules<2>-Footnote-602506417
Ref: New and Improved Modules<2>-Footnote-612506482
Ref: New and Improved Modules<2>-Footnote-622506549
Ref: New and Improved Modules<2>-Footnote-632506617
Node: The ast module2506685
Ref: whatsnew/2 6 the-ast-module2506798
Ref: 15eb2506798
Node: The future_builtins module2509459
Ref: whatsnew/2 6 the-future-builtins-module2509623
Ref: 15ec2509623
Node: The json module JavaScript Object Notation2510729
Ref: whatsnew/2 6 the-json-module-javascript-object-notation2510921
Ref: 15ee2510921
Node: The plistlib module A Property-List Parser2511933
Ref: whatsnew/2 6 the-plistlib-module-a-property-list-parser2512118
Ref: 15ef2512118
Node: ctypes Enhancements2513489
Ref: whatsnew/2 6 ctypes-enhancements2513652
Ref: 15f02513652
Ref: ctypes Enhancements-Footnote-12515419
Ref: ctypes Enhancements-Footnote-22515486
Node: Improved SSL Support2515550
Ref: whatsnew/2 6 improved-ssl-support2515662
Ref: 15f12515662
Ref: Improved SSL Support-Footnote-12516613
Node: Deprecations and Removals2516646
Ref: whatsnew/2 6 deprecations-and-removals2516805
Ref: 15f22516805
Ref: Deprecations and Removals-Footnote-12518667
Node: Build and C API Changes<9>2518709
Ref: whatsnew/2 6 build-and-c-api-changes2518862
Ref: 15f42518862
Ref: Build and C API Changes<9>-Footnote-12526400
Ref: Build and C API Changes<9>-Footnote-22526455
Ref: Build and C API Changes<9>-Footnote-32526510
Ref: Build and C API Changes<9>-Footnote-42526574
Ref: Build and C API Changes<9>-Footnote-52526641
Ref: Build and C API Changes<9>-Footnote-62526705
Ref: Build and C API Changes<9>-Footnote-72526769
Node: Port-Specific Changes Windows<2>2526836
Ref: whatsnew/2 6 port-specific-changes-windows2526973
Ref: 15fb2526973
Ref: Port-Specific Changes Windows<2>-Footnote-12529439
Ref: Port-Specific Changes Windows<2>-Footnote-22529505
Ref: Port-Specific Changes Windows<2>-Footnote-32529572
Node: Port-Specific Changes Mac OS X<2>2529636
Ref: whatsnew/2 6 port-specific-changes-mac-os-x2529808
Ref: 16002529808
Ref: Port-Specific Changes Mac OS X<2>-Footnote-12531079
Node: Port-Specific Changes IRIX2531146
Ref: whatsnew/2 6 port-specific-changes-irix2531277
Ref: 16012531277
Node: Porting to Python 2 62531796
Ref: whatsnew/2 6 porting-to-python-2-62531943
Ref: 16022531943
Ref: Porting to Python 2 6-Footnote-12535767
Ref: Porting to Python 2 6-Footnote-22535834
Ref: Porting to Python 2 6-Footnote-32535901
Node: Acknowledgements<2>2535968
Ref: whatsnew/2 6 acknowledgements2536080
Ref: 16042536080
Ref: whatsnew/2 6 acks2536080
Ref: 16052536080
Node: What’s New in Python 2 52536422
Ref: whatsnew/2 5 doc2536572
Ref: 16062536572
Ref: whatsnew/2 5 translation-repo2536572
Ref: 16072536572
Ref: whatsnew/2 5 what-s-new-in-python-2-52536572
Ref: 16082536572
Ref: What’s New in Python 2 5-Footnote-12540228
Node: PEP 308 Conditional Expressions2540270
Ref: whatsnew/2 5 pep-3082540409
Ref: 16092540409
Ref: whatsnew/2 5 pep-308-conditional-expressions2540409
Ref: 160e2540409
Ref: PEP 308 Conditional Expressions-Footnote-12543895
Ref: PEP 308 Conditional Expressions-Footnote-22543937
Node: PEP 309 Partial Function Application2543979
Ref: whatsnew/2 5 pep-3092544177
Ref: 160f2544177
Ref: whatsnew/2 5 pep-309-partial-function-application2544177
Ref: 16102544177
Ref: PEP 309 Partial Function Application-Footnote-12547026
Node: PEP 314 Metadata for Python Software Packages v1 12547068
Ref: whatsnew/2 5 pep-3142547272
Ref: 16112547272
Ref: whatsnew/2 5 pep-314-metadata-for-python-software-packages-v1-12547272
Ref: 16122547272
Ref: PEP 314 Metadata for Python Software Packages v1 1-Footnote-12549110
Node: PEP 328 Absolute and Relative Imports2549152
Ref: whatsnew/2 5 pep-3282549356
Ref: 160c2549356
Ref: whatsnew/2 5 pep-328-absolute-and-relative-imports2549356
Ref: 16132549356
Ref: PEP 328 Absolute and Relative Imports-Footnote-12553172
Ref: PEP 328 Absolute and Relative Imports-Footnote-22553214
Node: PEP 338 Executing Modules as Scripts2553256
Ref: whatsnew/2 5 pep-3382553444
Ref: 16142553444
Ref: whatsnew/2 5 pep-338-executing-modules-as-scripts2553444
Ref: 16152553444
Ref: PEP 338 Executing Modules as Scripts-Footnote-12554343
Node: PEP 341 Unified try/except/finally2554385
Ref: whatsnew/2 5 pep-3412554566
Ref: 160d2554566
Ref: whatsnew/2 5 pep-341-unified-try-except-finally2554566
Ref: 16162554566
Ref: PEP 341 Unified try/except/finally-Footnote-12556337
Node: PEP 342 New Generator Features2556379
Ref: whatsnew/2 5 pep-3422556559
Ref: 160b2556559
Ref: whatsnew/2 5 pep-342-new-generator-features2556559
Ref: 16172556559
Ref: PEP 342 New Generator Features-Footnote-12563228
Ref: PEP 342 New Generator Features-Footnote-22563270
Ref: PEP 342 New Generator Features-Footnote-32563312
Ref: PEP 342 New Generator Features-Footnote-42563354
Ref: PEP 342 New Generator Features-Footnote-52563396
Node: PEP 343 The “with” statement<2>2563438
Ref: whatsnew/2 5 pep-3432563623
Ref: 160a2563623
Ref: whatsnew/2 5 pep-343-the-with-statement2563623
Ref: 16182563623
Node: Writing Context Managers<2>2566645
Ref: whatsnew/2 5 new-25-context-managers2566777
Ref: 16192566777
Ref: whatsnew/2 5 writing-context-managers2566777
Ref: 161a2566777
Node: The contextlib module<2>2571174
Ref: whatsnew/2 5 contextlibmod2571306
Ref: 161b2571306
Ref: whatsnew/2 5 the-contextlib-module2571306
Ref: 161c2571306
Ref: The contextlib module<2>-Footnote-12573802
Node: PEP 352 Exceptions as New-Style Classes2573844
Ref: whatsnew/2 5 pep-3522574038
Ref: 161d2574038
Ref: whatsnew/2 5 pep-352-exceptions-as-new-style-classes2574038
Ref: 161e2574038
Ref: PEP 352 Exceptions as New-Style Classes-Footnote-12576530
Node: PEP 353 Using ssize_t as the index type2576572
Ref: whatsnew/2 5 pep-3532576765
Ref: 161f2576765
Ref: whatsnew/2 5 pep-353-using-ssize-t-as-the-index-type2576765
Ref: 16202576765
Ref: PEP 353 Using ssize_t as the index type-Footnote-12579667
Ref: PEP 353 Using ssize_t as the index type-Footnote-22579709
Node: PEP 357 The “__index__” method2579751
Ref: whatsnew/2 5 pep-3572579931
Ref: 16222579931
Ref: whatsnew/2 5 pep-357-the-index-method2579931
Ref: 16232579931
Ref: PEP 357 The “__index__” method-Footnote-12581644
Node: Other Language Changes<15>2581686
Ref: whatsnew/2 5 other-lang2581859
Ref: 16262581859
Ref: whatsnew/2 5 other-language-changes2581859
Ref: 16272581859
Ref: Other Language Changes<15>-Footnote-12588818
Node: Interactive Interpreter Changes2588860
Ref: whatsnew/2 5 interactive2588980
Ref: 162d2588980
Ref: whatsnew/2 5 interactive-interpreter-changes2588980
Ref: 162e2588980
Node: Optimizations<15>2589757
Ref: whatsnew/2 5 optimizations2589877
Ref: 16302589877
Ref: whatsnew/2 5 opts2589877
Ref: 16312589877
Node: New Improved and Removed Modules2593693
Ref: whatsnew/2 5 modules2593859
Ref: 16322593859
Ref: whatsnew/2 5 new-improved-and-removed-modules2593859
Ref: 16332593859
Ref: New Improved and Removed Modules-Footnote-12618368
Ref: New Improved and Removed Modules-Footnote-22618410
Ref: New Improved and Removed Modules-Footnote-32618469
Node: The ctypes package2618528
Ref: whatsnew/2 5 module-ctypes2618647
Ref: 163d2618647
Ref: whatsnew/2 5 the-ctypes-package2618647
Ref: 163e2618647
Node: The ElementTree package2621929
Ref: whatsnew/2 5 module-etree2622076
Ref: 163f2622076
Ref: whatsnew/2 5 the-elementtree-package2622076
Ref: 16402622076
Node: The hashlib package2627378
Ref: whatsnew/2 5 module-hashlib2627526
Ref: 16412627526
Ref: whatsnew/2 5 the-hashlib-package2627526
Ref: 16422627526
Node: The sqlite3 package2629115
Ref: whatsnew/2 5 module-sqlite2629259
Ref: 16432629259
Ref: whatsnew/2 5 the-sqlite3-package2629259
Ref: 16442629259
Ref: The sqlite3 package-Footnote-12633274
Ref: The sqlite3 package-Footnote-22633316
Node: The wsgiref package2633358
Ref: whatsnew/2 5 module-wsgiref2633474
Ref: 16452633474
Ref: whatsnew/2 5 the-wsgiref-package2633474
Ref: 16462633474
Ref: The wsgiref package-Footnote-12634461
Ref: The wsgiref package-Footnote-22634503
Node: Build and C API Changes<10>2634545
Ref: whatsnew/2 5 build-and-c-api-changes2634706
Ref: 16472634706
Ref: whatsnew/2 5 build-api2634706
Ref: 16482634706
Ref: Build and C API Changes<10>-Footnote-12641740
Ref: Build and C API Changes<10>-Footnote-22641782
Ref: Build and C API Changes<10>-Footnote-32641824
Node: Port-Specific Changes2641866
Ref: whatsnew/2 5 port-specific-changes2641951
Ref: 16542641951
Ref: whatsnew/2 5 ports2641951
Ref: 16552641951
Ref: Port-Specific Changes-Footnote-12642628
Node: Porting to Python 2 52642692
Ref: whatsnew/2 5 porting2642840
Ref: 16562642840
Ref: whatsnew/2 5 porting-to-python-2-52642840
Ref: 16572642840
Ref: Porting to Python 2 5-Footnote-12645669
Node: Acknowledgements<3>2645711
Ref: whatsnew/2 5 acknowledgements2645823
Ref: 16582645823
Node: What’s New in Python 2 42646317
Ref: whatsnew/2 4 doc2646467
Ref: 16592646467
Ref: whatsnew/2 4 translation-repo2646467
Ref: 165a2646467
Ref: whatsnew/2 4 what-s-new-in-python-2-42646467
Ref: 165b2646467
Node: PEP 218 Built-In Set Objects2648572
Ref: whatsnew/2 4 pep-218-built-in-set-objects2648715
Ref: 165c2648715
Ref: PEP 218 Built-In Set Objects-Footnote-12650955
Node: PEP 237 Unifying Long Integers and Integers2650997
Ref: whatsnew/2 4 pep-237-unifying-long-integers-and-integers2651178
Ref: 165d2651178
Ref: PEP 237 Unifying Long Integers and Integers-Footnote-12652223
Node: PEP 289 Generator Expressions2652265
Ref: whatsnew/2 4 pep-289-generator-expressions2652454
Ref: 165e2652454
Ref: PEP 289 Generator Expressions-Footnote-12654730
Node: PEP 292 Simpler String Substitutions2654772
Ref: whatsnew/2 4 pep-292-simpler-string-substitutions2654962
Ref: 165f2654962
Ref: PEP 292 Simpler String Substitutions-Footnote-12656763
Node: PEP 318 Decorators for Functions and Methods2656805
Ref: whatsnew/2 4 pep-318-decorators-for-functions-and-methods2656991
Ref: 16602656991
Ref: PEP 318 Decorators for Functions and Methods-Footnote-12661522
Ref: PEP 318 Decorators for Functions and Methods-Footnote-22661564
Node: PEP 322 Reverse Iteration2661606
Ref: whatsnew/2 4 pep-322-reverse-iteration2661785
Ref: 16622661785
Ref: PEP 322 Reverse Iteration-Footnote-12662751
Node: PEP 324 New subprocess Module2662793
Ref: whatsnew/2 4 pep-324-new-subprocess-module2662953
Ref: 16632662953
Ref: PEP 324 New subprocess Module-Footnote-12666740
Node: PEP 327 Decimal Data Type2666782
Ref: whatsnew/2 4 pep-327-decimal-data-type2666943
Ref: 16652666943
Node: Why is Decimal needed?2667515
Ref: whatsnew/2 4 why-is-decimal-needed2667624
Ref: 16662667624
Node: The Decimal type2670208
Ref: whatsnew/2 4 the-decimal-type2670342
Ref: 16672670342
Node: The Context type2673514
Ref: whatsnew/2 4 the-context-type2673617
Ref: 16682673617
Ref: The Context type-Footnote-12676228
Ref: The Context type-Footnote-22676270
Node: PEP 328 Multi-line Imports2676353
Ref: whatsnew/2 4 pep-328-multi-line-imports2676536
Ref: 16692676536
Ref: PEP 328 Multi-line Imports-Footnote-12678034
Node: PEP 331 Locale-Independent Float/String Conversions2678076
Ref: whatsnew/2 4 pep-331-locale-independent-float-string-conversions2678260
Ref: 166a2678260
Ref: PEP 331 Locale-Independent Float/String Conversions-Footnote-12679991
Ref: PEP 331 Locale-Independent Float/String Conversions-Footnote-22680081
Node: Other Language Changes<16>2680123
Ref: whatsnew/2 4 other-language-changes2680319
Ref: 166b2680319
Ref: Other Language Changes<16>-Footnote-12687303
Ref: Other Language Changes<16>-Footnote-22687345
Ref: Other Language Changes<16>-Footnote-32687387
Ref: Other Language Changes<16>-Footnote-42687429
Ref: Other Language Changes<16>-Footnote-52687471
Ref: Other Language Changes<16>-Footnote-62687513
Node: Optimizations<16>2687555
Ref: whatsnew/2 4 optimizations2687635
Ref: 166d2687635
Node: New Improved and Deprecated Modules<3>2690390
Ref: whatsnew/2 4 new-improved-and-deprecated-modules2690562
Ref: 166e2690562
Ref: New Improved and Deprecated Modules<3>-Footnote-12707873
Node: cookielib2707932
Ref: whatsnew/2 4 cookielib2708035
Ref: 16722708035
Node: doctest<5>2708975
Ref: whatsnew/2 4 doctest2709078
Ref: 16732709078
Node: Build and C API Changes<11>2711818
Ref: whatsnew/2 4 build-and-c-api-changes2711985
Ref: 16792711985
Node: Port-Specific Changes<2>2714618
Ref: whatsnew/2 4 port-specific-changes2714706
Ref: 16802714706
Node: Porting to Python 2 42714885
Ref: whatsnew/2 4 porting-to-python-2-42715033
Ref: 16812715033
Node: Acknowledgements<4>2717001
Ref: whatsnew/2 4 acknowledgements2717113
Ref: 16832717113
Ref: whatsnew/2 4 acks2717113
Ref: 16842717113
Node: What’s New in Python 2 32717446
Ref: whatsnew/2 3 doc2717596
Ref: 16852717596
Ref: whatsnew/2 3 translation-repo2717596
Ref: 16862717596
Ref: whatsnew/2 3 what-s-new-in-python-2-32717596
Ref: 16872717596
Node: PEP 218 A Standard Set Datatype2720615
Ref: whatsnew/2 3 pep-218-a-standard-set-datatype2720743
Ref: 16892720743
Ref: PEP 218 A Standard Set Datatype-Footnote-12723264
Node: PEP 255 Simple Generators2723306
Ref: whatsnew/2 3 pep-255-simple-generators2723472
Ref: 168e2723472
Ref: whatsnew/2 3 section-generators2723472
Ref: 168f2723472
Ref: PEP 255 Simple Generators-Footnote-12729654
Ref: PEP 255 Simple Generators-Footnote-22729696
Node: PEP 263 Source Code Encodings2729738
Ref: whatsnew/2 3 pep-263-source-code-encodings2729916
Ref: 16902729916
Ref: whatsnew/2 3 section-encodings2729916
Ref: 16912729916
Ref: PEP 263 Source Code Encodings-Footnote-12731132
Node: PEP 273 Importing Modules from ZIP Archives2731174
Ref: whatsnew/2 3 pep-273-importing-modules-from-zip-archives2731375
Ref: 16922731375
Ref: PEP 273 Importing Modules from ZIP Archives-Footnote-12733413
Ref: PEP 273 Importing Modules from ZIP Archives-Footnote-22733455
Ref: PEP 273 Importing Modules from ZIP Archives-Footnote-32733497
Node: PEP 277 Unicode file name support for Windows NT2733539
Ref: whatsnew/2 3 pep-277-unicode-file-name-support-for-windows-nt2733744
Ref: 16942733744
Ref: PEP 277 Unicode file name support for Windows NT-Footnote-12735229
Node: PEP 278 Universal Newline Support2735271
Ref: whatsnew/2 3 pep-278-universal-newline-support2735450
Ref: 16962735450
Ref: PEP 278 Universal Newline Support-Footnote-12736965
Node: PEP 279 enumerate2737007
Ref: whatsnew/2 3 pep-279-enumerate2737165
Ref: 16972737165
Ref: whatsnew/2 3 section-enumerate2737165
Ref: 16982737165
Ref: PEP 279 enumerate-Footnote-12738027
Node: PEP 282 The logging Package2738069
Ref: whatsnew/2 3 pep-282-the-logging-package2738216
Ref: 16992738216
Ref: PEP 282 The logging Package-Footnote-12743017
Ref: PEP 282 The logging Package-Footnote-22743059
Node: PEP 285 A Boolean Type2743101
Ref: whatsnew/2 3 pep-285-a-boolean-type2743269
Ref: 169f2743269
Ref: whatsnew/2 3 section-bool2743269
Ref: 16a02743269
Ref: PEP 285 A Boolean Type-Footnote-12745722
Ref: PEP 285 A Boolean Type-Footnote-22745764
Node: PEP 293 Codec Error Handling Callbacks2745806
Ref: whatsnew/2 3 pep-293-codec-error-handling-callbacks2745995
Ref: 16a12745995
Ref: PEP 293 Codec Error Handling Callbacks-Footnote-12747538
Node: PEP 301 Package Index and Metadata for Distutils2747580
Ref: whatsnew/2 3 pep-301-package-index-and-metadata-for-distutils2747771
Ref: 16a42747771
Ref: whatsnew/2 3 section-pep3012747771
Ref: 16a52747771
Ref: PEP 301 Package Index and Metadata for Distutils-Footnote-12749419
Ref: PEP 301 Package Index and Metadata for Distutils-Footnote-22749455
Node: PEP 302 New Import Hooks2749497
Ref: whatsnew/2 3 pep-302-new-import-hooks2749679
Ref: 16a62749679
Ref: whatsnew/2 3 section-pep3022749679
Ref: 16932749679
Ref: PEP 302 New Import Hooks-Footnote-12752290
Ref: PEP 302 New Import Hooks-Footnote-22752332
Ref: PEP 302 New Import Hooks-Footnote-32752374
Node: PEP 305 Comma-separated Files2752416
Ref: whatsnew/2 3 pep-305-comma-separated-files2752577
Ref: 16a72752577
Ref: whatsnew/2 3 section-pep3052752577
Ref: 16a82752577
Ref: PEP 305 Comma-separated Files-Footnote-12754062
Node: PEP 307 Pickle Enhancements2754104
Ref: whatsnew/2 3 pep-307-pickle-enhancements2754256
Ref: 16a92754256
Ref: whatsnew/2 3 section-pep3072754256
Ref: 16aa2754256
Ref: PEP 307 Pickle Enhancements-Footnote-12756233
Ref: PEP 307 Pickle Enhancements-Footnote-22756275
Ref: PEP 307 Pickle Enhancements-Footnote-32756317
Node: Extended Slices2756359
Ref: whatsnew/2 3 extended-slices2756508
Ref: 16ad2756508
Ref: whatsnew/2 3 section-slices2756508
Ref: 16ae2756508
Node: Other Language Changes<17>2759896
Ref: whatsnew/2 3 other-language-changes2760056
Ref: 16af2760056
Ref: Other Language Changes<17>-Footnote-12767848
Node: String Changes2767921
Ref: whatsnew/2 3 string-changes2768024
Ref: 16b52768024
Node: Optimizations<17>2770551
Ref: whatsnew/2 3 optimizations2770654
Ref: 16ba2770654
Node: New Improved and Deprecated Modules<4>2772117
Ref: whatsnew/2 3 new-improved-and-deprecated-modules2772301
Ref: 16bc2772301
Ref: New Improved and Deprecated Modules<4>-Footnote-12797092
Node: Date/Time Type2797132
Ref: whatsnew/2 3 date-time-type2797249
Ref: 16d02797249
Node: The optparse Module2799581
Ref: whatsnew/2 3 the-optparse-module2799698
Ref: 16d32799698
Node: Pymalloc A Specialized Object Allocator2801772
Ref: whatsnew/2 3 pymalloc-a-specialized-object-allocator2801957
Ref: 16d62801957
Ref: whatsnew/2 3 section-pymalloc2801957
Ref: 16d72801957
Node: Build and C API Changes<12>2805855
Ref: whatsnew/2 3 build-and-c-api-changes2806028
Ref: 16d92806028
Node: Port-Specific Changes<3>2809454
Ref: whatsnew/2 3 port-specific-changes2809542
Ref: 16df2809542
Node: Other Changes and Fixes<2>2810777
Ref: whatsnew/2 3 other-changes-and-fixes2810932
Ref: 16e02810932
Ref: whatsnew/2 3 section-other2810932
Ref: 16bb2810932
Node: Porting to Python 2 32813429
Ref: whatsnew/2 3 porting-to-python-2-32813576
Ref: 16e32813576
Node: Acknowledgements<5>2816385
Ref: whatsnew/2 3 acknowledgements2816497
Ref: 16e42816497
Ref: whatsnew/2 3 acks2816497
Ref: 16e52816497
Node: What’s New in Python 2 22817118
Ref: whatsnew/2 2 doc2817268
Ref: 16e62817268
Ref: whatsnew/2 2 translation-repo2817268
Ref: 16e72817268
Ref: whatsnew/2 2 what-s-new-in-python-2-22817268
Ref: 16e82817268
Node: Introduction2818003
Ref: whatsnew/2 2 introduction2818126
Ref: 16e92818126
Ref: Introduction-Footnote-12819096
Ref: Introduction-Footnote-22819145
Node: PEPs 252 and 253 Type and Class Changes2819194
Ref: whatsnew/2 2 peps-252-and-253-type-and-class-changes2819343
Ref: 16ea2819343
Node: Old and New Classes2822781
Ref: whatsnew/2 2 old-and-new-classes2822896
Ref: 16ed2822896
Ref: Old and New Classes-Footnote-12825302
Node: Descriptors2825344
Ref: whatsnew/2 2 descriptors2825505
Ref: 16ee2825505
Node: Multiple Inheritance The Diamond Rule2829372
Ref: whatsnew/2 2 multiple-inheritance-the-diamond-rule2829530
Ref: 16f02829530
Ref: Multiple Inheritance The Diamond Rule-Footnote-12832415
Node: Attribute Access2832457
Ref: whatsnew/2 2 attribute-access2832617
Ref: 16f12832617
Node: Related Links2836419
Ref: whatsnew/2 2 related-links2836533
Ref: 16f32836533
Ref: whatsnew/2 2 sect-rellinks2836533
Ref: 16ec2836533
Ref: Related Links-Footnote-12838008
Ref: Related Links-Footnote-22838050
Ref: Related Links-Footnote-32838092
Ref: Related Links-Footnote-42838134
Ref: Related Links-Footnote-52838176
Node: PEP 234 Iterators2838218
Ref: whatsnew/2 2 pep-234-iterators2838383
Ref: 16f52838383
Ref: PEP 234 Iterators-Footnote-12843266
Node: PEP 255 Simple Generators<2>2843308
Ref: whatsnew/2 2 pep-255-simple-generators2843480
Ref: 16f82843480
Ref: PEP 255 Simple Generators<2>-Footnote-12849539
Ref: PEP 255 Simple Generators<2>-Footnote-22849581
Node: PEP 237 Unifying Long Integers and Integers<2>2849623
Ref: whatsnew/2 2 pep-237-unifying-long-integers-and-integers2849816
Ref: 16f92849816
Ref: PEP 237 Unifying Long Integers and Integers<2>-Footnote-12851545
Node: PEP 238 Changing the Division Operator2851587
Ref: whatsnew/2 2 pep-238-changing-the-division-operator2851767
Ref: 16fa2851767
Ref: PEP 238 Changing the Division Operator-Footnote-12855420
Ref: PEP 238 Changing the Division Operator-Footnote-22855462
Ref: PEP 238 Changing the Division Operator-Footnote-32855504
Node: Unicode Changes2855546
Ref: whatsnew/2 2 unicode-changes2855701
Ref: 16fc2855701
Ref: Unicode Changes-Footnote-12858331
Ref: Unicode Changes-Footnote-22858373
Node: PEP 227 Nested Scopes2858415
Ref: whatsnew/2 2 pep-227-nested-scopes2858559
Ref: 16fd2858559
Ref: PEP 227 Nested Scopes-Footnote-12862907
Node: New and Improved Modules<3>2862949
Ref: whatsnew/2 2 new-and-improved-modules2863107
Ref: 16fe2863107
Ref: New and Improved Modules<3>-Footnote-12869811
Ref: New and Improved Modules<3>-Footnote-22869870
Ref: New and Improved Modules<3>-Footnote-32869929
Ref: New and Improved Modules<3>-Footnote-42869988
Ref: New and Improved Modules<3>-Footnote-52870047
Node: Interpreter Changes and Fixes2870105
Ref: whatsnew/2 2 interpreter-changes-and-fixes2870268
Ref: 17032870268
Node: Other Changes and Fixes<3>2875039
Ref: whatsnew/2 2 other-changes-and-fixes2875194
Ref: 17132875194
Ref: Other Changes and Fixes<3>-Footnote-12881862
Node: Acknowledgements<6>2881904
Ref: whatsnew/2 2 acknowledgements2882021
Ref: 17162882021
Node: What’s New in Python 2 12882622
Ref: whatsnew/2 1 doc2882772
Ref: 17172882772
Ref: whatsnew/2 1 translation-repo2882772
Ref: 17182882772
Ref: whatsnew/2 1 what-s-new-in-python-2-12882772
Ref: 17192882772
Node: Introduction<2>2883777
Ref: whatsnew/2 1 introduction2883888
Ref: 171a2883888
Node: PEP 227 Nested Scopes<2>2884984
Ref: whatsnew/2 1 pep-227-nested-scopes2885133
Ref: 171b2885133
Ref: PEP 227 Nested Scopes<2>-Footnote-12889503
Ref: PEP 227 Nested Scopes<2>-Footnote-22889545
Ref: PEP 227 Nested Scopes<2>-Footnote-32889587
Node: PEP 236 __future__ Directives2889629
Ref: whatsnew/2 1 pep-236-future-directives2889787
Ref: 171c2889787
Ref: PEP 236 __future__ Directives-Footnote-12891028
Node: PEP 207 Rich Comparisons2891070
Ref: whatsnew/2 1 pep-207-rich-comparisons2891229
Ref: 171d2891229
Ref: PEP 207 Rich Comparisons-Footnote-12894641
Ref: PEP 207 Rich Comparisons-Footnote-22894683
Node: PEP 230 Warning Framework2894725
Ref: whatsnew/2 1 pep-230-warning-framework2894879
Ref: 171f2894879
Ref: PEP 230 Warning Framework-Footnote-12898164
Ref: PEP 230 Warning Framework-Footnote-22898206
Node: PEP 229 New Build System2898248
Ref: whatsnew/2 1 pep-229-new-build-system2898401
Ref: 17212898401
Ref: PEP 229 New Build System-Footnote-12900325
Node: PEP 205 Weak References2900367
Ref: whatsnew/2 1 pep-205-weak-references2900522
Ref: 17222900522
Ref: PEP 205 Weak References-Footnote-12903639
Node: PEP 232 Function Attributes2903681
Ref: whatsnew/2 1 pep-232-function-attributes2903867
Ref: 17232903867
Ref: PEP 232 Function Attributes-Footnote-12905391
Node: PEP 235 Importing Modules on Case-Insensitive Platforms2905433
Ref: whatsnew/2 1 pep-235-importing-modules-on-case-insensitive-platforms2905628
Ref: 17242905628
Node: PEP 217 Interactive Display Hook2906531
Ref: whatsnew/2 1 pep-217-interactive-display-hook2906725
Ref: 17252906725
Ref: PEP 217 Interactive Display Hook-Footnote-12907658
Node: PEP 208 New Coercion Model2907700
Ref: whatsnew/2 1 pep-208-new-coercion-model2907874
Ref: 17272907874
Ref: PEP 208 New Coercion Model-Footnote-12909500
Node: PEP 241 Metadata in Python Packages2909542
Ref: whatsnew/2 1 pep-241-metadata-in-python-packages2909711
Ref: 17282909711
Ref: PEP 241 Metadata in Python Packages-Footnote-12911832
Ref: PEP 241 Metadata in Python Packages-Footnote-22911914
Ref: PEP 241 Metadata in Python Packages-Footnote-32911956
Ref: PEP 241 Metadata in Python Packages-Footnote-42911998
Ref: PEP 241 Metadata in Python Packages-Footnote-52912040
Node: New and Improved Modules<4>2912082
Ref: whatsnew/2 1 new-and-improved-modules2912251
Ref: 17292912251
Node: Other Changes and Fixes<4>2918108
Ref: whatsnew/2 1 other-changes-and-fixes2918261
Ref: 172a2918261
Node: Acknowledgements<7>2924216
Ref: whatsnew/2 1 acknowledgements2924333
Ref: 172e2924333
Node: What’s New in Python 2 02924624
Ref: whatsnew/2 0 doc2924757
Ref: 172f2924757
Ref: whatsnew/2 0 translation-repo2924757
Ref: 17302924757
Ref: whatsnew/2 0 what-s-new-in-python-2-02924757
Ref: 17312924757
Node: Introduction<3>2925445
Ref: whatsnew/2 0 introduction2925554
Ref: 17322925554
Node: What About Python 1 6?2926438
Ref: whatsnew/2 0 what-about-python-1-62926579
Ref: 17332926579
Node: New Development Process2927820
Ref: whatsnew/2 0 new-development-process2927956
Ref: 17342927956
Ref: New Development Process-Footnote-12933088
Ref: New Development Process-Footnote-22933130
Ref: New Development Process-Footnote-32933172
Node: Unicode<2>2933214
Ref: whatsnew/2 0 unicode2933347
Ref: 17352933347
Ref: Unicode<2>-Footnote-12939515
Node: List Comprehensions2939557
Ref: whatsnew/2 0 list-comprehensions2939687
Ref: 17362939687
Node: Augmented Assignment2943419
Ref: whatsnew/2 0 augmented-assignment2943553
Ref: 17372943553
Node: String Methods2945083
Ref: whatsnew/2 0 string-methods2945226
Ref: 17382945226
Node: Garbage Collection of Cycles2947079
Ref: whatsnew/2 0 garbage-collection-of-cycles2947220
Ref: 17392947220
Node: Other Core Changes2950563
Ref: whatsnew/2 0 other-core-changes2950704
Ref: 173a2950704
Node: Minor Language Changes2950989
Ref: whatsnew/2 0 minor-language-changes2951104
Ref: 173b2951104
Node: Changes to Built-in Functions2956185
Ref: whatsnew/2 0 changes-to-built-in-functions2956300
Ref: 173e2956300
Node: Porting to 2 02958586
Ref: whatsnew/2 0 porting-to-2-02958726
Ref: 173f2958726
Node: Extending/Embedding Changes2964070
Ref: whatsnew/2 0 extending-embedding-changes2964232
Ref: 17422964232
Node: Distutils Making Modules Easy to Install2968084
Ref: whatsnew/2 0 distutils-making-modules-easy-to-install2968243
Ref: 17472968243
Node: XML Modules2971594
Ref: whatsnew/2 0 xml-modules2971740
Ref: 17482971740
Node: SAX2 Support2972639
Ref: whatsnew/2 0 sax2-support2972719
Ref: 17492972719
Node: DOM Support2974379
Ref: whatsnew/2 0 dom-support2974489
Ref: 174d2974489
Node: Relationship to PyXML2977317
Ref: whatsnew/2 0 relationship-to-pyxml2977406
Ref: 174e2977406
Node: Module changes2978696
Ref: whatsnew/2 0 module-changes2978816
Ref: 174f2978816
Node: New modules<2>2981302
Ref: whatsnew/2 0 new-modules2981428
Ref: 17502981428
Node: IDLE Improvements2985430
Ref: whatsnew/2 0 idle-improvements2985572
Ref: 17512985572
Node: Deleted and Deprecated Modules2986707
Ref: whatsnew/2 0 deleted-and-deprecated-modules2986854
Ref: 17522986854
Node: Acknowledgements<8>2987606
Ref: whatsnew/2 0 acknowledgements2987727
Ref: 17532987727
Ref: Acknowledgements<8>-Footnote-12988303
Ref: Acknowledgements<8>-Footnote-22988343
Node: Changelog2988407
Ref: whatsnew/changelog doc2988505
Ref: 17542988505
Ref: whatsnew/changelog changelog2988505
Ref: 1422988505
Ref: whatsnew/changelog id12988505
Ref: 17552988505
Ref: whatsnew/changelog translation-repo2988505
Ref: 17562988505
Node: Python next2994500
Ref: whatsnew/changelog python-next2994585
Ref: 17572994585
Node: Windows2994819
Ref: whatsnew/changelog windows2994894
Ref: 17582994894
Ref: Windows-Footnote-12995097
Node: Tools/Demos2995153
Ref: whatsnew/changelog tools-demos2995242
Ref: 17592995242
Ref: Tools/Demos-Footnote-12995465
Node: Tests2995521
Ref: whatsnew/changelog tests2995611
Ref: 175a2995611
Ref: Tests-Footnote-12996318
Ref: Tests-Footnote-22996374
Ref: Tests-Footnote-32996429
Ref: Tests-Footnote-42996485
Ref: Tests-Footnote-52996541
Node: Security2996606
Ref: whatsnew/changelog security2996692
Ref: 175b2996692
Ref: Security-Footnote-12997782
Ref: Security-Footnote-22997838
Ref: Security-Footnote-32997894
Ref: Security-Footnote-42997950
Ref: Security-Footnote-52998006
Ref: Security-Footnote-62998062
Node: Library2998118
Ref: whatsnew/changelog library2998206
Ref: 175c2998206
Ref: Library-Footnote-13010160
Ref: Library-Footnote-23010216
Ref: Library-Footnote-33010272
Ref: Library-Footnote-43010328
Ref: Library-Footnote-53010384
Ref: Library-Footnote-63010440
Ref: Library-Footnote-73010496
Ref: Library-Footnote-83010552
Ref: Library-Footnote-93010608
Ref: Library-Footnote-103010664
Ref: Library-Footnote-113010721
Ref: Library-Footnote-123010777
Ref: Library-Footnote-133010834
Ref: Library-Footnote-143010891
Ref: Library-Footnote-153010948
Ref: Library-Footnote-163011005
Ref: Library-Footnote-173011062
Ref: Library-Footnote-183011119
Ref: Library-Footnote-193011176
Ref: Library-Footnote-203011233
Ref: Library-Footnote-213011290
Ref: Library-Footnote-223011347
Ref: Library-Footnote-233011404
Ref: Library-Footnote-243011461
Ref: Library-Footnote-253011518
Ref: Library-Footnote-263011575
Ref: Library-Footnote-273011632
Ref: Library-Footnote-283011689
Ref: Library-Footnote-293011746
Ref: Library-Footnote-303011803
Ref: Library-Footnote-313011860
Ref: Library-Footnote-323011917
Ref: Library-Footnote-333011974
Ref: Library-Footnote-343012031
Ref: Library-Footnote-353012088
Ref: Library-Footnote-363012145
Ref: Library-Footnote-373012202
Ref: Library-Footnote-383012259
Ref: Library-Footnote-393012316
Ref: Library-Footnote-403012373
Ref: Library-Footnote-413012430
Ref: Library-Footnote-423012487
Ref: Library-Footnote-433012544
Ref: Library-Footnote-443012601
Ref: Library-Footnote-453012658
Ref: Library-Footnote-463012715
Ref: Library-Footnote-473012772
Ref: Library-Footnote-483012829
Ref: Library-Footnote-493012886
Ref: Library-Footnote-503012943
Ref: Library-Footnote-513013000
Ref: Library-Footnote-523013057
Ref: Library-Footnote-533013114
Ref: Library-Footnote-543013171
Ref: Library-Footnote-553013227
Ref: Library-Footnote-563013284
Ref: Library-Footnote-573013340
Ref: Library-Footnote-583013397
Ref: Library-Footnote-593013454
Ref: Library-Footnote-603013511
Ref: Library-Footnote-613013568
Ref: Library-Footnote-623013625
Ref: Library-Footnote-633013681
Ref: Library-Footnote-643013738
Ref: Library-Footnote-653013795
Ref: Library-Footnote-663013852
Node: IDLE<3>3013909
Ref: whatsnew/changelog idle3014005
Ref: 17733014005
Ref: IDLE<3>-Footnote-13014154
Node: Documentation<2>3014210
Ref: whatsnew/changelog documentation3014316
Ref: 17743014316
Ref: Documentation<2>-Footnote-13014465
Node: Core and Builtins3014521
Ref: whatsnew/changelog core-and-builtins3014625
Ref: 17763014625
Ref: Core and Builtins-Footnote-13020078
Ref: Core and Builtins-Footnote-23020134
Ref: Core and Builtins-Footnote-33020190
Ref: Core and Builtins-Footnote-43020246
Ref: Core and Builtins-Footnote-53020302
Ref: Core and Builtins-Footnote-63020358
Ref: Core and Builtins-Footnote-73020414
Ref: Core and Builtins-Footnote-83020470
Ref: Core and Builtins-Footnote-93020526
Ref: Core and Builtins-Footnote-103020582
Ref: Core and Builtins-Footnote-113020639
Ref: Core and Builtins-Footnote-123020696
Ref: Core and Builtins-Footnote-133020753
Ref: Core and Builtins-Footnote-143020810
Ref: Core and Builtins-Footnote-153020867
Ref: Core and Builtins-Footnote-163020924
Ref: Core and Builtins-Footnote-173020981
Ref: Core and Builtins-Footnote-183021038
Ref: Core and Builtins-Footnote-193021095
Ref: Core and Builtins-Footnote-203021152
Ref: Core and Builtins-Footnote-213021209
Ref: Core and Builtins-Footnote-223021266
Ref: Core and Builtins-Footnote-233021323
Ref: Core and Builtins-Footnote-243021380
Ref: Core and Builtins-Footnote-253021437
Ref: Core and Builtins-Footnote-263021494
Ref: Core and Builtins-Footnote-273021551
Ref: Core and Builtins-Footnote-283021608
Ref: Core and Builtins-Footnote-293021665
Ref: Core and Builtins-Footnote-303021721
Ref: Core and Builtins-Footnote-313021778
Node: C API3021835
Ref: whatsnew/changelog c-api3021928
Ref: 17823021928
Ref: C API-Footnote-13022259
Ref: C API-Footnote-23022315
Node: Build3022371
Ref: whatsnew/changelog build3022438
Ref: 17833022438
Ref: Build-Footnote-13023167
Ref: Build-Footnote-23023223
Ref: Build-Footnote-33023279
Node: Python 3 14 2 final3023335
Ref: whatsnew/changelog python-3-14-2-final3023448
Ref: 17843023448
Node: Security<2>3023655
Ref: whatsnew/changelog id23023741
Ref: 17853023741
Ref: Security<2>-Footnote-13024318
Ref: Security<2>-Footnote-23024374
Node: Library<2>3024430
Ref: whatsnew/changelog id33024545
Ref: 17873024545
Ref: Library<2>-Footnote-13025927
Ref: Library<2>-Footnote-23025983
Ref: Library<2>-Footnote-33026039
Node: Core and Builtins<2>3026095
Ref: whatsnew/changelog id43026209
Ref: 17883026209
Ref: Core and Builtins<2>-Footnote-13026446
Node: Library<3>3026502
Ref: whatsnew/changelog id53026597
Ref: 17893026597
Ref: Library<3>-Footnote-13026785
Node: Python 3 14 1 final3026841
Ref: whatsnew/changelog python-3-14-1-final3026962
Ref: 178a3026962
Node: Windows<2>3027706
Ref: whatsnew/changelog id63027795
Ref: 178b3027795
Ref: Windows<2>-Footnote-13027989
Node: Tools/Demos<2>3028045
Ref: whatsnew/changelog id73028151
Ref: 178c3028151
Ref: Tools/Demos<2>-Footnote-13029119
Ref: Tools/Demos<2>-Footnote-23029175
Ref: Tools/Demos<2>-Footnote-33029231
Ref: Tools/Demos<2>-Footnote-43029287
Ref: Tools/Demos<2>-Footnote-53029343
Ref: Tools/Demos<2>-Footnote-63029399
Node: Tests<2>3029455
Ref: whatsnew/changelog id83029562
Ref: 178d3029562
Ref: Tests<2>-Footnote-13030222
Ref: Tests<2>-Footnote-23030278
Ref: Tests<2>-Footnote-33030334
Ref: Tests<2>-Footnote-43030390
Node: Security<3>3030446
Ref: whatsnew/changelog id93030549
Ref: 178e3030549
Ref: Security<3>-Footnote-13032266
Ref: Security<3>-Footnote-23032322
Ref: Security<3>-Footnote-33032378
Ref: Security<3>-Footnote-43032434
Ref: Security<3>-Footnote-53032490
Ref: Security<3>-Footnote-63032546
Ref: Security<3>-Footnote-73032602
Node: Library<4>3032658
Ref: whatsnew/changelog id103032760
Ref: 17913032760
Ref: Library<4>-Footnote-13052495
Ref: Library<4>-Footnote-23052550
Ref: Library<4>-Footnote-33052605
Ref: Library<4>-Footnote-43052661
Ref: Library<4>-Footnote-53052716
Ref: Library<4>-Footnote-63052772
Ref: Library<4>-Footnote-73052828
Ref: Library<4>-Footnote-83052884
Ref: Library<4>-Footnote-93052940
Ref: Library<4>-Footnote-103052996
Ref: Library<4>-Footnote-113053053
Ref: Library<4>-Footnote-123053110
Ref: Library<4>-Footnote-133053167
Ref: Library<4>-Footnote-143053224
Ref: Library<4>-Footnote-153053281
Ref: Library<4>-Footnote-163053338
Ref: Library<4>-Footnote-173053395
Ref: Library<4>-Footnote-183053452
Ref: Library<4>-Footnote-193053509
Ref: Library<4>-Footnote-203053566
Ref: Library<4>-Footnote-213053623
Ref: Library<4>-Footnote-223053680
Ref: Library<4>-Footnote-233053737
Ref: Library<4>-Footnote-243053794
Ref: Library<4>-Footnote-253053851
Ref: Library<4>-Footnote-263053908
Ref: Library<4>-Footnote-273053965
Ref: Library<4>-Footnote-283054022
Ref: Library<4>-Footnote-293054079
Ref: Library<4>-Footnote-303054136
Ref: Library<4>-Footnote-313054193
Ref: Library<4>-Footnote-323054250
Ref: Library<4>-Footnote-333054307
Ref: Library<4>-Footnote-343054364
Ref: Library<4>-Footnote-353054421
Ref: Library<4>-Footnote-363054478
Ref: Library<4>-Footnote-373054535
Ref: Library<4>-Footnote-383054592
Ref: Library<4>-Footnote-393054649
Ref: Library<4>-Footnote-403054706
Ref: Library<4>-Footnote-413054763
Ref: Library<4>-Footnote-423054820
Ref: Library<4>-Footnote-433054877
Ref: Library<4>-Footnote-443054934
Ref: Library<4>-Footnote-453054991
Ref: Library<4>-Footnote-463055048
Ref: Library<4>-Footnote-473055105
Ref: Library<4>-Footnote-483055162
Ref: Library<4>-Footnote-493055218
Ref: Library<4>-Footnote-503055274
Ref: Library<4>-Footnote-513055331
Ref: Library<4>-Footnote-523055371
Ref: Library<4>-Footnote-533055413
Ref: Library<4>-Footnote-543055470
Ref: Library<4>-Footnote-553055527
Ref: Library<4>-Footnote-563055584
Ref: Library<4>-Footnote-573055640
Ref: Library<4>-Footnote-583055697
Ref: Library<4>-Footnote-593055754
Ref: Library<4>-Footnote-603055811
Ref: Library<4>-Footnote-613055868
Ref: Library<4>-Footnote-623055925
Ref: Library<4>-Footnote-633055982
Ref: Library<4>-Footnote-643056039
Ref: Library<4>-Footnote-653056096
Ref: Library<4>-Footnote-663056153
Ref: Library<4>-Footnote-673056210
Ref: Library<4>-Footnote-683056253
Ref: Library<4>-Footnote-693056310
Ref: Library<4>-Footnote-703056367
Ref: Library<4>-Footnote-713056424
Ref: Library<4>-Footnote-723056481
Ref: Library<4>-Footnote-733056538
Ref: Library<4>-Footnote-743056595
Ref: Library<4>-Footnote-753056651
Ref: Library<4>-Footnote-763056708
Ref: Library<4>-Footnote-773056764
Ref: Library<4>-Footnote-783056821
Ref: Library<4>-Footnote-793056878
Ref: Library<4>-Footnote-803056935
Ref: Library<4>-Footnote-813056991
Ref: Library<4>-Footnote-823057048
Ref: Library<4>-Footnote-833057105
Ref: Library<4>-Footnote-843057162
Ref: Library<4>-Footnote-853057219
Ref: Library<4>-Footnote-863057276
Ref: Library<4>-Footnote-873057333
Ref: Library<4>-Footnote-883057390
Ref: Library<4>-Footnote-893057447
Ref: Library<4>-Footnote-903057504
Ref: Library<4>-Footnote-913057560
Ref: Library<4>-Footnote-923057616
Ref: Library<4>-Footnote-933057673
Ref: Library<4>-Footnote-943057730
Ref: Library<4>-Footnote-953057787
Ref: Library<4>-Footnote-963057843
Ref: Library<4>-Footnote-973057899
Ref: Library<4>-Footnote-983057956
Ref: Library<4>-Footnote-993058013
Ref: Library<4>-Footnote-1003058070
Ref: Library<4>-Footnote-1013058127
Ref: Library<4>-Footnote-1023058185
Ref: Library<4>-Footnote-1033058243
Ref: Library<4>-Footnote-1043058301
Ref: Library<4>-Footnote-1053058359
Ref: Library<4>-Footnote-1063058417
Ref: Library<4>-Footnote-1073058475
Ref: Library<4>-Footnote-1083058533
Ref: Library<4>-Footnote-1093058591
Ref: Library<4>-Footnote-1103058649
Ref: Library<4>-Footnote-1113058707
Ref: Library<4>-Footnote-1123058765
Ref: Library<4>-Footnote-1133058823
Ref: Library<4>-Footnote-1143058881
Ref: Library<4>-Footnote-1153058939
Ref: Library<4>-Footnote-1163058997
Ref: Library<4>-Footnote-1173059055
Ref: Library<4>-Footnote-1183059112
Ref: Library<4>-Footnote-1193059179
Node: IDLE<4>3059246
Ref: whatsnew/changelog id113059353
Ref: 17b33059353
Ref: IDLE<4>-Footnote-13059630
Ref: IDLE<4>-Footnote-23059685
Node: Documentation<3>3059741
Ref: whatsnew/changelog id123059858
Ref: 17b43059858
Ref: Documentation<3>-Footnote-13060341
Ref: Documentation<3>-Footnote-23060397
Ref: Documentation<3>-Footnote-33060462
Node: Core and Builtins<3>3060518
Ref: whatsnew/changelog id133060638
Ref: 17b63060638
Ref: Core and Builtins<3>-Footnote-13060833
Node: Library<5>3060889
Ref: whatsnew/changelog id143061013
Ref: 17b73061013
Ref: Library<5>-Footnote-13061193
Node: Core and Builtins<4>3061249
Ref: whatsnew/changelog id153061363
Ref: 17b83061363
Ref: Core and Builtins<4>-Footnote-13062798
Ref: Core and Builtins<4>-Footnote-23062854
Ref: Core and Builtins<4>-Footnote-33062910
Ref: Core and Builtins<4>-Footnote-43062966
Ref: Core and Builtins<4>-Footnote-53063022
Ref: Core and Builtins<4>-Footnote-63063078
Ref: Core and Builtins<4>-Footnote-73063134
Ref: Core and Builtins<4>-Footnote-83063190
Node: Library<6>3063246
Ref: whatsnew/changelog id163063370
Ref: 17ba3063370
Ref: Library<6>-Footnote-13063536
Node: Core and Builtins<5>3063592
Ref: whatsnew/changelog id173063706
Ref: 17bb3063706
Ref: Core and Builtins<5>-Footnote-13063993
Node: Library<7>3064049
Ref: whatsnew/changelog id183064173
Ref: 17bc3064173
Ref: Library<7>-Footnote-13064383
Node: Core and Builtins<6>3064439
Ref: whatsnew/changelog id193064553
Ref: 17bd3064553
Ref: Core and Builtins<6>-Footnote-13065827
Ref: Core and Builtins<6>-Footnote-23065883
Ref: Core and Builtins<6>-Footnote-33065939
Ref: Core and Builtins<6>-Footnote-43065995
Ref: Core and Builtins<6>-Footnote-53066051
Ref: Core and Builtins<6>-Footnote-63066107
Ref: Core and Builtins<6>-Footnote-73066163
Node: Library<8>3066219
Ref: whatsnew/changelog id203066343
Ref: 17c13066343
Ref: Library<8>-Footnote-13066675
Node: Core and Builtins<7>3066731
Ref: whatsnew/changelog id213066845
Ref: 17c53066845
Ref: Core and Builtins<7>-Footnote-13070143
Ref: Core and Builtins<7>-Footnote-23070199
Ref: Core and Builtins<7>-Footnote-33070255
Ref: Core and Builtins<7>-Footnote-43070311
Ref: Core and Builtins<7>-Footnote-53070367
Ref: Core and Builtins<7>-Footnote-63070423
Ref: Core and Builtins<7>-Footnote-73070479
Ref: Core and Builtins<7>-Footnote-83070535
Ref: Core and Builtins<7>-Footnote-93070591
Ref: Core and Builtins<7>-Footnote-103070647
Ref: Core and Builtins<7>-Footnote-113070704
Ref: Core and Builtins<7>-Footnote-123070761
Ref: Core and Builtins<7>-Footnote-133070818
Ref: Core and Builtins<7>-Footnote-143070875
Ref: Core and Builtins<7>-Footnote-153070932
Ref: Core and Builtins<7>-Footnote-163070989
Ref: Core and Builtins<7>-Footnote-173071032
Ref: Core and Builtins<7>-Footnote-183071089
Node: Library<9>3071145
Ref: whatsnew/changelog id223071269
Ref: 17c63071269
Ref: Library<9>-Footnote-13071440
Node: Core and Builtins<8>3071496
Ref: whatsnew/changelog id233071611
Ref: 17c73071611
Ref: Core and Builtins<8>-Footnote-13072477
Ref: Core and Builtins<8>-Footnote-23072533
Ref: Core and Builtins<8>-Footnote-33072589
Ref: Core and Builtins<8>-Footnote-43072645
Ref: Core and Builtins<8>-Footnote-53072701
Node: Library<10>3072756
Ref: whatsnew/changelog id243072881
Ref: 17cb3072881
Ref: Library<10>-Footnote-13073239
Ref: Library<10>-Footnote-23073295
Node: Core and Builtins<9>3073351
Ref: whatsnew/changelog id253073464
Ref: 17cc3073464
Ref: Core and Builtins<9>-Footnote-13074684
Ref: Core and Builtins<9>-Footnote-23074740
Ref: Core and Builtins<9>-Footnote-33074796
Ref: Core and Builtins<9>-Footnote-43074851
Ref: Core and Builtins<9>-Footnote-53074907
Ref: Core and Builtins<9>-Footnote-63074963
Node: C API<2>3075019
Ref: whatsnew/changelog id263075129
Ref: 17cd3075129
Ref: C API<2>-Footnote-13076468
Ref: C API<2>-Footnote-23076524
Ref: C API<2>-Footnote-33076580
Ref: C API<2>-Footnote-43076636
Ref: C API<2>-Footnote-53076692
Ref: C API<2>-Footnote-63076748
Node: Build<2>3076804
Ref: whatsnew/changelog id273076885
Ref: 17d03076885
Ref: Build<2>-Footnote-13078255
Ref: Build<2>-Footnote-23078311
Ref: Build<2>-Footnote-33078367
Ref: Build<2>-Footnote-43078423
Ref: Build<2>-Footnote-53078479
Ref: Build<2>-Footnote-63078535
Ref: Build<2>-Footnote-73078591
Ref: Build<2>-Footnote-83078647
Node: Python 3 14 0 final3078703
Ref: whatsnew/changelog python-3-14-0-final3078838
Ref: 17d13078838
Node: macOS3079044
Ref: whatsnew/changelog macos3079124
Ref: 17d23079124
Ref: macOS-Footnote-13079322
Ref: macOS-Footnote-23079378
Node: Windows<3>3079434
Ref: whatsnew/changelog id283079537
Ref: 17d33079537
Ref: Windows<3>-Footnote-13079674
Node: Tools/Demos<3>3079730
Ref: whatsnew/changelog id293079839
Ref: 17d43079839
Ref: Tools/Demos<3>-Footnote-13080460
Ref: Tools/Demos<3>-Footnote-23080516
Ref: Tools/Demos<3>-Footnote-33080572
Node: Security<4>3080628
Ref: whatsnew/changelog id303080738
Ref: 17d53080738
Ref: Security<4>-Footnote-13081071
Node: Library<11>3081127
Ref: whatsnew/changelog id313081214
Ref: 17d73081214
Ref: Library<11>-Footnote-13081339
Node: Python 3 14 0 release candidate 33081395
Ref: whatsnew/changelog python-3-14-0-release-candidate-33081544
Ref: 17d83081544
Node: Windows<4>3081812
Ref: whatsnew/changelog id323081915
Ref: 17d93081915
Ref: Windows<4>-Footnote-13082074
Node: Tools/Demos<4>3082130
Ref: whatsnew/changelog id333082253
Ref: 17da3082253
Ref: Tools/Demos<4>-Footnote-13082523
Node: Security<5>3082579
Ref: whatsnew/changelog id343082703
Ref: 17db3082703
Ref: Security<5>-Footnote-13083184
Node: Library<12>3083240
Ref: whatsnew/changelog id353083371
Ref: 17dc3083371
Ref: Library<12>-Footnote-13085853
Ref: Library<12>-Footnote-23085909
Ref: Library<12>-Footnote-33085965
Ref: Library<12>-Footnote-43086021
Ref: Library<12>-Footnote-53086077
Ref: Library<12>-Footnote-63086133
Ref: Library<12>-Footnote-73086189
Ref: Library<12>-Footnote-83086245
Ref: Library<12>-Footnote-93086300
Ref: Library<12>-Footnote-103086356
Ref: Library<12>-Footnote-113086413
Ref: Library<12>-Footnote-123086470
Ref: Library<12>-Footnote-133086526
Ref: Library<12>-Footnote-143086583
Ref: Library<12>-Footnote-153086640
Node: Core and Builtins<10>3086697
Ref: whatsnew/changelog id363086808
Ref: 17e03086808
Ref: Core and Builtins<10>-Footnote-13088494
Ref: Core and Builtins<10>-Footnote-23088549
Ref: Core and Builtins<10>-Footnote-33088605
Ref: Core and Builtins<10>-Footnote-43088661
Ref: Core and Builtins<10>-Footnote-53088717
Ref: Core and Builtins<10>-Footnote-63088773
Ref: Core and Builtins<10>-Footnote-73088829
Ref: Core and Builtins<10>-Footnote-83088885
Ref: Core and Builtins<10>-Footnote-93088941
Ref: Core and Builtins<10>-Footnote-103088997
Ref: Core and Builtins<10>-Footnote-113089054
Node: Python 3 14 0 release candidate 23089111
Ref: whatsnew/changelog python-3-14-0-release-candidate-23089274
Ref: 17e33089274
Node: macOS<2>3089578
Ref: whatsnew/changelog id373089675
Ref: 17e43089675
Ref: macOS<2>-Footnote-13090065
Ref: macOS<2>-Footnote-23090121
Node: Windows<5>3090177
Ref: whatsnew/changelog id383090294
Ref: 17e53090294
Ref: Windows<5>-Footnote-13090438
Node: Library<13>3090494
Ref: whatsnew/changelog id393090619
Ref: 17e63090619
Ref: Library<13>-Footnote-13092167
Ref: Library<13>-Footnote-23092223
Ref: Library<13>-Footnote-33092279
Ref: Library<13>-Footnote-43092335
Ref: Library<13>-Footnote-53092391
Ref: Library<13>-Footnote-63092447
Ref: Library<13>-Footnote-73092503
Ref: Library<13>-Footnote-83092559
Ref: Library<13>-Footnote-93092615
Node: Documentation<4>3092671
Ref: whatsnew/changelog id403092807
Ref: 17e73092807
Ref: Documentation<4>-Footnote-13092974
Node: Core and Builtins<11>3093030
Ref: whatsnew/changelog id413093163
Ref: 17e83093163
Ref: Core and Builtins<11>-Footnote-13094794
Ref: Core and Builtins<11>-Footnote-23094850
Ref: Core and Builtins<11>-Footnote-33094906
Ref: Core and Builtins<11>-Footnote-43094962
Ref: Core and Builtins<11>-Footnote-53095018
Ref: Core and Builtins<11>-Footnote-63095074
Ref: Core and Builtins<11>-Footnote-73095130
Node: C API<3>3095186
Ref: whatsnew/changelog id423095311
Ref: 17e93095311
Ref: C API<3>-Footnote-13095509
Node: Build<3>3095565
Ref: whatsnew/changelog id433095660
Ref: 17eb3095660
Ref: Build<3>-Footnote-13095776
Node: Python 3 14 0 release candidate 13095832
Ref: whatsnew/changelog python-3-14-0-release-candidate-13095982
Ref: 17ec3095982
Node: Tools/Demos<5>3096401
Ref: whatsnew/changelog id443096505
Ref: 17ed3096505
Ref: Tools/Demos<5>-Footnote-13096686
Node: Security<6>3096742
Ref: whatsnew/changelog id453096866
Ref: 17ee3096866
Ref: Security<6>-Footnote-13097249
Ref: Security<6>-Footnote-23097305
Node: Library<14>3097361
Ref: whatsnew/changelog id463097492
Ref: 17ef3097492
Ref: Library<14>-Footnote-13099260
Ref: Library<14>-Footnote-23099316
Ref: Library<14>-Footnote-33099372
Ref: Library<14>-Footnote-43099428
Ref: Library<14>-Footnote-53099484
Ref: Library<14>-Footnote-63099540
Ref: Library<14>-Footnote-73099596
Ref: Library<14>-Footnote-83099651
Ref: Library<14>-Footnote-93099707
Ref: Library<14>-Footnote-103099763
Ref: Library<14>-Footnote-113099820
Ref: Library<14>-Footnote-123099877
Ref: Library<14>-Footnote-133099934
Node: Core and Builtins<12>3099991
Ref: whatsnew/changelog id473100122
Ref: 17f03100122
Ref: Core and Builtins<12>-Footnote-13100337
Node: Library<15>3100393
Ref: whatsnew/changelog id483100534
Ref: 17f13100534
Ref: Library<15>-Footnote-13100692
Node: Core and Builtins<13>3100748
Ref: whatsnew/changelog id493100879
Ref: 17f23100879
Ref: Core and Builtins<13>-Footnote-13101819
Ref: Core and Builtins<13>-Footnote-23101875
Ref: Core and Builtins<13>-Footnote-33101931
Ref: Core and Builtins<13>-Footnote-43101987
Ref: Core and Builtins<13>-Footnote-53102043
Ref: Core and Builtins<13>-Footnote-63102099
Node: Library<16>3102141
Ref: whatsnew/changelog id503102282
Ref: 17f33102282
Ref: Library<16>-Footnote-13102463
Node: Core and Builtins<14>3102519
Ref: whatsnew/changelog id513102647
Ref: 17f43102647
Ref: Core and Builtins<14>-Footnote-13103313
Ref: Core and Builtins<14>-Footnote-23103369
Ref: Core and Builtins<14>-Footnote-33103425
Ref: Core and Builtins<14>-Footnote-43103480
Node: C API<4>3103536
Ref: whatsnew/changelog id523103661
Ref: 17f53103661
Ref: C API<4>-Footnote-13104120
Ref: C API<4>-Footnote-23104176
Ref: C API<4>-Footnote-33104232
Node: Build<4>3104288
Ref: whatsnew/changelog id533104383
Ref: 17f73104383
Ref: Build<4>-Footnote-13104576
Node: Python 3 14 0 beta 43104632
Ref: whatsnew/changelog python-3-14-0-beta-43104769
Ref: 17f83104769
Node: Tools/Demos<6>3105080
Ref: whatsnew/changelog id543105168
Ref: 17f93105168
Ref: Tools/Demos<6>-Footnote-13105560
Ref: Tools/Demos<6>-Footnote-23105616
Node: Tests<3>3105672
Ref: whatsnew/changelog id553105780
Ref: 17fa3105780
Ref: Tests<3>-Footnote-13106066
Ref: Tests<3>-Footnote-23106122
Node: Security<7>3106178
Ref: whatsnew/changelog id563106283
Ref: 17fb3106283
Ref: Security<7>-Footnote-13108181
Ref: Security<7>-Footnote-23108237
Ref: Security<7>-Footnote-33108293
Ref: Security<7>-Footnote-43108349
Node: Library<17>3108405
Ref: whatsnew/changelog id573108518
Ref: 17fc3108518
Ref: Library<17>-Footnote-13113234
Ref: Library<17>-Footnote-23113290
Ref: Library<17>-Footnote-33113346
Ref: Library<17>-Footnote-43113401
Ref: Library<17>-Footnote-53113457
Ref: Library<17>-Footnote-63113513
Ref: Library<17>-Footnote-73113568
Ref: Library<17>-Footnote-83113623
Ref: Library<17>-Footnote-93113679
Ref: Library<17>-Footnote-103113735
Ref: Library<17>-Footnote-113113792
Ref: Library<17>-Footnote-123113849
Ref: Library<17>-Footnote-133113906
Ref: Library<17>-Footnote-143113963
Ref: Library<17>-Footnote-153114020
Ref: Library<17>-Footnote-163114077
Ref: Library<17>-Footnote-173114134
Ref: Library<17>-Footnote-183114191
Ref: Library<17>-Footnote-193114248
Ref: Library<17>-Footnote-203114305
Ref: Library<17>-Footnote-213114362
Ref: Library<17>-Footnote-223114419
Ref: Library<17>-Footnote-233114476
Ref: Library<17>-Footnote-243114533
Ref: Library<17>-Footnote-253114589
Ref: Library<17>-Footnote-263114645
Node: Documentation<5>3114702
Ref: whatsnew/changelog id583114825
Ref: 18013114825
Ref: Documentation<5>-Footnote-13114995
Node: Core and Builtins<15>3115051
Ref: whatsnew/changelog id593115171
Ref: 18023115171
Ref: Core and Builtins<15>-Footnote-13116613
Ref: Core and Builtins<15>-Footnote-23116669
Ref: Core and Builtins<15>-Footnote-33116724
Ref: Core and Builtins<15>-Footnote-43116780
Ref: Core and Builtins<15>-Footnote-53116836
Ref: Core and Builtins<15>-Footnote-63116892
Ref: Core and Builtins<15>-Footnote-73116948
Ref: Core and Builtins<15>-Footnote-83117004
Ref: Core and Builtins<15>-Footnote-93117060
Node: C API<5>3117116
Ref: whatsnew/changelog id603117228
Ref: 18033117228
Ref: C API<5>-Footnote-13117400
Node: Build<5>3117456
Ref: whatsnew/changelog id613117538
Ref: 18043117538
Ref: Build<5>-Footnote-13117707
Node: Python 3 14 0 beta 33117763
Ref: whatsnew/changelog python-3-14-0-beta-33117887
Ref: 18053117887
Node: Windows<6>3118394
Ref: whatsnew/changelog id623118478
Ref: 18063118478
Ref: Windows<6>-Footnote-13118731
Node: Tests<4>3118787
Ref: whatsnew/changelog id633118891
Ref: 18073118891
Ref: Tests<4>-Footnote-13119224
Ref: Tests<4>-Footnote-23119280
Ref: Tests<4>-Footnote-33119336
Node: Security<8>3119392
Ref: whatsnew/changelog id643119497
Ref: 18083119497
Ref: Security<8>-Footnote-13120140
Ref: Security<8>-Footnote-23120196
Ref: Security<8>-Footnote-33120252
Ref: Security<8>-Footnote-43120308
Ref: Security<8>-Footnote-53120363
Ref: Security<8>-Footnote-63120418
Node: Library<18>3120473
Ref: whatsnew/changelog id653120586
Ref: 18093120586
Ref: Library<18>-Footnote-13124929
Ref: Library<18>-Footnote-23124984
Ref: Library<18>-Footnote-33125040
Ref: Library<18>-Footnote-43125096
Ref: Library<18>-Footnote-53125152
Ref: Library<18>-Footnote-63125208
Ref: Library<18>-Footnote-73125264
Ref: Library<18>-Footnote-83125320
Ref: Library<18>-Footnote-93125376
Ref: Library<18>-Footnote-103125432
Ref: Library<18>-Footnote-113125508
Ref: Library<18>-Footnote-123125565
Ref: Library<18>-Footnote-133125622
Ref: Library<18>-Footnote-143125679
Ref: Library<18>-Footnote-153125722
Ref: Library<18>-Footnote-163125779
Ref: Library<18>-Footnote-173125836
Ref: Library<18>-Footnote-183125893
Ref: Library<18>-Footnote-193125950
Ref: Library<18>-Footnote-203126007
Ref: Library<18>-Footnote-213126064
Ref: Library<18>-Footnote-223126124
Ref: Library<18>-Footnote-233126181
Ref: Library<18>-Footnote-243126238
Ref: Library<18>-Footnote-253126295
Ref: Library<18>-Footnote-263126352
Ref: Library<18>-Footnote-273126409
Ref: Library<18>-Footnote-283126466
Ref: Library<18>-Footnote-293126523
Node: Documentation<6>3126580
Ref: whatsnew/changelog id663126703
Ref: 18103126703
Ref: Documentation<6>-Footnote-13127054
Ref: Documentation<6>-Footnote-23127110
Node: Core and Builtins<16>3127175
Ref: whatsnew/changelog id673127298
Ref: 18113127298
Ref: Core and Builtins<16>-Footnote-13127808
Ref: Core and Builtins<16>-Footnote-23127864
Node: Library<19>3127920
Ref: whatsnew/changelog id683128048
Ref: 18123128048
Ref: Library<19>-Footnote-13128344
Node: Core and Builtins<17>3128400
Ref: whatsnew/changelog id693128518
Ref: 18133128518
Ref: Core and Builtins<17>-Footnote-13129419
Ref: Core and Builtins<17>-Footnote-23129475
Ref: Core and Builtins<17>-Footnote-33129531
Node: Library<20>3129587
Ref: whatsnew/changelog id703129715
Ref: 18143129715
Ref: Library<20>-Footnote-13129896
Node: Core and Builtins<18>3129952
Ref: whatsnew/changelog id713130070
Ref: 18153130070
Ref: Core and Builtins<18>-Footnote-13130428
Ref: Core and Builtins<18>-Footnote-23130484
Ref: Core and Builtins<18>-Footnote-33130526
Node: Library<21>3130582
Ref: whatsnew/changelog id723130710
Ref: 18163130710
Ref: Library<21>-Footnote-13130899
Node: Core and Builtins<19>3130955
Ref: whatsnew/changelog id733131070
Ref: 18173131070
Ref: Core and Builtins<19>-Footnote-13131880
Ref: Core and Builtins<19>-Footnote-23131936
Ref: Core and Builtins<19>-Footnote-33131992
Ref: Core and Builtins<19>-Footnote-43132048
Node: C API<6>3132104
Ref: whatsnew/changelog id743132216
Ref: 18183132216
Ref: C API<6>-Footnote-13133055
Ref: C API<6>-Footnote-23133111
Ref: C API<6>-Footnote-33133167
Node: Build<6>3133223
Ref: whatsnew/changelog id753133305
Ref: 181b3133305
Ref: Build<6>-Footnote-13134120
Ref: Build<6>-Footnote-23134176
Ref: Build<6>-Footnote-33134232
Ref: Build<6>-Footnote-43134288
Ref: Build<6>-Footnote-53134344
Ref: Build<6>-Footnote-63134400
Node: Python 3 14 0 beta 23134442
Ref: whatsnew/changelog python-3-14-0-beta-23134566
Ref: 181d3134566
Node: Windows<7>3134867
Ref: whatsnew/changelog id763134957
Ref: 181e3134957
Ref: Windows<7>-Footnote-13135903
Ref: Windows<7>-Footnote-23135959
Ref: Windows<7>-Footnote-33136014
Ref: Windows<7>-Footnote-43136070
Node: Tools/Demos<7>3136126
Ref: whatsnew/changelog id773136233
Ref: 181f3136233
Ref: Tools/Demos<7>-Footnote-13136433
Node: Tests<5>3136489
Ref: whatsnew/changelog id783136597
Ref: 18203136597
Ref: Tests<5>-Footnote-13137223
Ref: Tests<5>-Footnote-23137279
Ref: Tests<5>-Footnote-33137335
Node: Security<9>3137391
Ref: whatsnew/changelog id793137496
Ref: 18213137496
Ref: Security<9>-Footnote-13137869
Ref: Security<9>-Footnote-23137925
Node: Library<22>3137981
Ref: whatsnew/changelog id803138099
Ref: 18223138099
Ref: Library<22>-Footnote-13146021
Ref: Library<22>-Footnote-23146077
Ref: Library<22>-Footnote-33146132
Ref: Library<22>-Footnote-43146188
Ref: Library<22>-Footnote-53146244
Ref: Library<22>-Footnote-63146300
Ref: Library<22>-Footnote-73146356
Ref: Library<22>-Footnote-83146411
Ref: Library<22>-Footnote-93146467
Ref: Library<22>-Footnote-103146522
Ref: Library<22>-Footnote-113146579
Ref: Library<22>-Footnote-123146636
Ref: Library<22>-Footnote-133146693
Ref: Library<22>-Footnote-143146750
Ref: Library<22>-Footnote-153146806
Ref: Library<22>-Footnote-163146863
Ref: Library<22>-Footnote-173146920
Ref: Library<22>-Footnote-183146977
Ref: Library<22>-Footnote-193147034
Ref: Library<22>-Footnote-203147091
Ref: Library<22>-Footnote-213147148
Ref: Library<22>-Footnote-223147205
Ref: Library<22>-Footnote-233147262
Ref: Library<22>-Footnote-243147318
Ref: Library<22>-Footnote-253147375
Ref: Library<22>-Footnote-263147432
Ref: Library<22>-Footnote-273147489
Ref: Library<22>-Footnote-283147546
Ref: Library<22>-Footnote-293147603
Ref: Library<22>-Footnote-303147660
Ref: Library<22>-Footnote-313147716
Ref: Library<22>-Footnote-323147773
Ref: Library<22>-Footnote-333147830
Ref: Library<22>-Footnote-343147887
Ref: Library<22>-Footnote-353147944
Ref: Library<22>-Footnote-363147987
Ref: Library<22>-Footnote-373148044
Ref: Library<22>-Footnote-383148101
Ref: Library<22>-Footnote-393148158
Ref: Library<22>-Footnote-403148215
Ref: Library<22>-Footnote-413148271
Ref: Library<22>-Footnote-423148328
Ref: Library<22>-Footnote-433148384
Ref: Library<22>-Footnote-443148440
Ref: Library<22>-Footnote-453148496
Ref: Library<22>-Footnote-463148562
Node: Core and Builtins<20>3148619
Ref: whatsnew/changelog id813148734
Ref: 182a3148734
Ref: Core and Builtins<20>-Footnote-13151109
Ref: Core and Builtins<20>-Footnote-23151165
Ref: Core and Builtins<20>-Footnote-33151221
Ref: Core and Builtins<20>-Footnote-43151277
Ref: Core and Builtins<20>-Footnote-53151332
Ref: Core and Builtins<20>-Footnote-63151388
Ref: Core and Builtins<20>-Footnote-73151444
Ref: Core and Builtins<20>-Footnote-83151500
Ref: Core and Builtins<20>-Footnote-93151556
Ref: Core and Builtins<20>-Footnote-103151612
Ref: Core and Builtins<20>-Footnote-113151669
Ref: Core and Builtins<20>-Footnote-123151726
Ref: Core and Builtins<20>-Footnote-133151783
Ref: Core and Builtins<20>-Footnote-143151840
Ref: Core and Builtins<20>-Footnote-153151897
Ref: Core and Builtins<20>-Footnote-163151954
Ref: Core and Builtins<20>-Footnote-173152011
Node: C API<7>3152056
Ref: whatsnew/changelog id823152168
Ref: 182c3152168
Ref: C API<7>-Footnote-13152409
Node: Build<7>3152465
Ref: whatsnew/changelog id833152547
Ref: 182f3152547
Ref: Build<7>-Footnote-13152981
Ref: Build<7>-Footnote-23153037
Ref: Build<7>-Footnote-33153079
Ref: Build<7>-Footnote-43153135
Node: Python 3 14 0 beta 13153191
Ref: whatsnew/changelog python-3-14-0-beta-13153316
Ref: 18303153316
Node: Windows<8>3153830
Ref: whatsnew/changelog id843153920
Ref: 18313153920
Ref: Windows<8>-Footnote-13154252
Ref: Windows<8>-Footnote-23154308
Node: Tools/Demos<8>3154364
Ref: whatsnew/changelog id853154471
Ref: 18323154471
Ref: Tools/Demos<8>-Footnote-13154788
Ref: Tools/Demos<8>-Footnote-23154844
Node: Tests<6>3154900
Ref: whatsnew/changelog id863155009
Ref: 18333155009
Ref: Tests<6>-Footnote-13155986
Ref: Tests<6>-Footnote-23156042
Ref: Tests<6>-Footnote-33156097
Ref: Tests<6>-Footnote-43156153
Ref: Tests<6>-Footnote-53156209
Node: Security<10>3156265
Ref: whatsnew/changelog id873156371
Ref: 18343156371
Ref: Security<10>-Footnote-13156879
Node: Library<23>3156935
Ref: whatsnew/changelog id883157040
Ref: 18353157040
Ref: Library<23>-Footnote-13176435
Ref: Library<23>-Footnote-23176491
Ref: Library<23>-Footnote-33176547
Ref: Library<23>-Footnote-43176603
Ref: Library<23>-Footnote-53176659
Ref: Library<23>-Footnote-63176715
Ref: Library<23>-Footnote-73176771
Ref: Library<23>-Footnote-83176827
Ref: Library<23>-Footnote-93176883
Ref: Library<23>-Footnote-103176939
Ref: Library<23>-Footnote-113176996
Ref: Library<23>-Footnote-123177053
Ref: Library<23>-Footnote-133177110
Ref: Library<23>-Footnote-143177167
Ref: Library<23>-Footnote-153177224
Ref: Library<23>-Footnote-163177281
Ref: Library<23>-Footnote-173177338
Ref: Library<23>-Footnote-183177395
Ref: Library<23>-Footnote-193177452
Ref: Library<23>-Footnote-203177509
Ref: Library<23>-Footnote-213177566
Ref: Library<23>-Footnote-223177623
Ref: Library<23>-Footnote-233177680
Ref: Library<23>-Footnote-243177737
Ref: Library<23>-Footnote-253177794
Ref: Library<23>-Footnote-263177851
Ref: Library<23>-Footnote-273177908
Ref: Library<23>-Footnote-283177965
Ref: Library<23>-Footnote-293178022
Ref: Library<23>-Footnote-303178079
Ref: Library<23>-Footnote-313178136
Ref: Library<23>-Footnote-323178193
Ref: Library<23>-Footnote-333178249
Ref: Library<23>-Footnote-343178306
Ref: Library<23>-Footnote-353178363
Ref: Library<23>-Footnote-363178420
Ref: Library<23>-Footnote-373178477
Ref: Library<23>-Footnote-383178534
Ref: Library<23>-Footnote-393178591
Ref: Library<23>-Footnote-403178648
Ref: Library<23>-Footnote-413178705
Ref: Library<23>-Footnote-423178762
Ref: Library<23>-Footnote-433178819
Ref: Library<23>-Footnote-443178876
Ref: Library<23>-Footnote-453178933
Ref: Library<23>-Footnote-463178990
Ref: Library<23>-Footnote-473179047
Ref: Library<23>-Footnote-483179103
Ref: Library<23>-Footnote-493179160
Ref: Library<23>-Footnote-503179217
Ref: Library<23>-Footnote-513179274
Ref: Library<23>-Footnote-523179330
Ref: Library<23>-Footnote-533179387
Ref: Library<23>-Footnote-543179444
Ref: Library<23>-Footnote-553179501
Ref: Library<23>-Footnote-563179558
Ref: Library<23>-Footnote-573179615
Ref: Library<23>-Footnote-583179672
Ref: Library<23>-Footnote-593179729
Ref: Library<23>-Footnote-603179786
Ref: Library<23>-Footnote-613179843
Ref: Library<23>-Footnote-623179900
Ref: Library<23>-Footnote-633179957
Ref: Library<23>-Footnote-643180014
Ref: Library<23>-Footnote-653180071
Ref: Library<23>-Footnote-663180128
Ref: Library<23>-Footnote-673180185
Ref: Library<23>-Footnote-683180242
Ref: Library<23>-Footnote-693180299
Ref: Library<23>-Footnote-703180356
Ref: Library<23>-Footnote-713180416
Ref: Library<23>-Footnote-723180473
Ref: Library<23>-Footnote-733180530
Ref: Library<23>-Footnote-743180586
Ref: Library<23>-Footnote-753180643
Ref: Library<23>-Footnote-763180700
Ref: Library<23>-Footnote-773180757
Ref: Library<23>-Footnote-783180814
Ref: Library<23>-Footnote-793180871
Ref: Library<23>-Footnote-803180927
Ref: Library<23>-Footnote-813180984
Ref: Library<23>-Footnote-823181041
Ref: Library<23>-Footnote-833181097
Ref: Library<23>-Footnote-843181154
Ref: Library<23>-Footnote-853181211
Ref: Library<23>-Footnote-863181268
Ref: Library<23>-Footnote-873181325
Ref: Library<23>-Footnote-883181382
Ref: Library<23>-Footnote-893181438
Ref: Library<23>-Footnote-903181495
Ref: Library<23>-Footnote-913181552
Ref: Library<23>-Footnote-923181609
Ref: Library<23>-Footnote-933181666
Ref: Library<23>-Footnote-943181723
Ref: Library<23>-Footnote-953181780
Ref: Library<23>-Footnote-963181837
Ref: Library<23>-Footnote-973181894
Ref: Library<23>-Footnote-983181951
Ref: Library<23>-Footnote-993182008
Ref: Library<23>-Footnote-1003182065
Ref: Library<23>-Footnote-1013182122
Ref: Library<23>-Footnote-1023182180
Ref: Library<23>-Footnote-1033182238
Ref: Library<23>-Footnote-1043182295
Ref: Library<23>-Footnote-1053182353
Ref: Library<23>-Footnote-1063182411
Ref: Library<23>-Footnote-1073182478
Node: IDLE<5>3182535
Ref: whatsnew/changelog id893182644
Ref: 18453182644
Ref: IDLE<5>-Footnote-13182784
Node: Documentation<7>3182840
Ref: whatsnew/changelog id903182959
Ref: 18463182959
Ref: Documentation<7>-Footnote-13183318
Ref: Documentation<7>-Footnote-23183374
Node: Core and Builtins<21>3183430
Ref: whatsnew/changelog id913183553
Ref: 18483183553
Ref: Core and Builtins<21>-Footnote-13185187
Ref: Core and Builtins<21>-Footnote-23185243
Ref: Core and Builtins<21>-Footnote-33185299
Ref: Core and Builtins<21>-Footnote-43185355
Ref: Core and Builtins<21>-Footnote-53185411
Ref: Core and Builtins<21>-Footnote-63185466
Ref: Core and Builtins<21>-Footnote-73185522
Ref: Core and Builtins<21>-Footnote-83185578
Node: Library<24>3185634
Ref: whatsnew/changelog id923185762
Ref: 184a3185762
Ref: Library<24>-Footnote-13185964
Ref: Library<24>-Footnote-23186020
Node: Core and Builtins<22>3186062
Ref: whatsnew/changelog id933186180
Ref: 184b3186180
Ref: Core and Builtins<22>-Footnote-13188733
Ref: Core and Builtins<22>-Footnote-23188789
Ref: Core and Builtins<22>-Footnote-33188845
Ref: Core and Builtins<22>-Footnote-43188901
Ref: Core and Builtins<22>-Footnote-53188957
Ref: Core and Builtins<22>-Footnote-63189013
Ref: Core and Builtins<22>-Footnote-73189069
Ref: Core and Builtins<22>-Footnote-83189125
Ref: Core and Builtins<22>-Footnote-93189181
Ref: Core and Builtins<22>-Footnote-103189237
Ref: Core and Builtins<22>-Footnote-113189294
Ref: Core and Builtins<22>-Footnote-123189337
Ref: Core and Builtins<22>-Footnote-133189394
Ref: Core and Builtins<22>-Footnote-143189451
Ref: Core and Builtins<22>-Footnote-153189494
Ref: Core and Builtins<22>-Footnote-163189551
Ref: Core and Builtins<22>-Footnote-173189608
Ref: Core and Builtins<22>-Footnote-183189665
Node: Library<25>3189722
Ref: whatsnew/changelog id943189850
Ref: 184d3189850
Ref: Library<25>-Footnote-13190029
Node: Core and Builtins<23>3190085
Ref: whatsnew/changelog id953190203
Ref: 184e3190203
Ref: Core and Builtins<23>-Footnote-13197149
Ref: Core and Builtins<23>-Footnote-23197205
Ref: Core and Builtins<23>-Footnote-33197261
Ref: Core and Builtins<23>-Footnote-43197317
Ref: Core and Builtins<23>-Footnote-53197373
Ref: Core and Builtins<23>-Footnote-63197429
Ref: Core and Builtins<23>-Footnote-73197485
Ref: Core and Builtins<23>-Footnote-83197541
Ref: Core and Builtins<23>-Footnote-93197597
Ref: Core and Builtins<23>-Footnote-103197653
Ref: Core and Builtins<23>-Footnote-113197710
Ref: Core and Builtins<23>-Footnote-123197767
Ref: Core and Builtins<23>-Footnote-133197824
Ref: Core and Builtins<23>-Footnote-143197881
Ref: Core and Builtins<23>-Footnote-153197938
Ref: Core and Builtins<23>-Footnote-163197995
Ref: Core and Builtins<23>-Footnote-173198052
Ref: Core and Builtins<23>-Footnote-183198109
Ref: Core and Builtins<23>-Footnote-193198166
Ref: Core and Builtins<23>-Footnote-203198223
Ref: Core and Builtins<23>-Footnote-213198280
Ref: Core and Builtins<23>-Footnote-223198337
Ref: Core and Builtins<23>-Footnote-233198394
Ref: Core and Builtins<23>-Footnote-243198451
Ref: Core and Builtins<23>-Footnote-253198508
Ref: Core and Builtins<23>-Footnote-263198565
Ref: Core and Builtins<23>-Footnote-273198622
Ref: Core and Builtins<23>-Footnote-283198679
Ref: Core and Builtins<23>-Footnote-293198736
Ref: Core and Builtins<23>-Footnote-303198793
Ref: Core and Builtins<23>-Footnote-313198850
Ref: Core and Builtins<23>-Footnote-323198906
Ref: Core and Builtins<23>-Footnote-333198963
Ref: Core and Builtins<23>-Footnote-343199020
Ref: Core and Builtins<23>-Footnote-353199077
Ref: Core and Builtins<23>-Footnote-363199134
Node: Library<26>3199191
Ref: whatsnew/changelog id963199306
Ref: 18513199306
Ref: Library<26>-Footnote-13199462
Node: C API<8>3199517
Ref: whatsnew/changelog id973199619
Ref: 18523199619
Ref: C API<8>-Footnote-13202503
Ref: C API<8>-Footnote-23202559
Ref: C API<8>-Footnote-33202615
Ref: C API<8>-Footnote-43202671
Ref: C API<8>-Footnote-53202727
Ref: C API<8>-Footnote-63202783
Ref: C API<8>-Footnote-73202839
Ref: C API<8>-Footnote-83202895
Ref: C API<8>-Footnote-93202951
Ref: C API<8>-Footnote-103203007
Ref: C API<8>-Footnote-113203064
Ref: C API<8>-Footnote-123203121
Ref: C API<8>-Footnote-133203178
Node: Build<8>3203234
Ref: whatsnew/changelog id983203316
Ref: 18543203316
Ref: Build<8>-Footnote-13204575
Ref: Build<8>-Footnote-23204631
Ref: Build<8>-Footnote-33204687
Ref: Build<8>-Footnote-43204743
Ref: Build<8>-Footnote-53204799
Ref: Build<8>-Footnote-63204855
Ref: Build<8>-Footnote-73204911
Ref: Build<8>-Footnote-83204967
Node: Python 3 14 0 alpha 73205023
Ref: whatsnew/changelog python-3-14-0-alpha-73205149
Ref: 18553205149
Node: macOS<3>3205575
Ref: whatsnew/changelog id993205660
Ref: 18563205660
Ref: macOS<3>-Footnote-13205963
Ref: macOS<3>-Footnote-23206019
Ref: macOS<3>-Footnote-33206075
Node: Windows<9>3206131
Ref: whatsnew/changelog id1003206239
Ref: 18573206239
Ref: Windows<9>-Footnote-13206799
Ref: Windows<9>-Footnote-23206855
Ref: Windows<9>-Footnote-33206911
Ref: Windows<9>-Footnote-43206966
Node: Tools/Demos<9>3207022
Ref: whatsnew/changelog id1013207130
Ref: 18583207130
Ref: Tools/Demos<9>-Footnote-13207452
Ref: Tools/Demos<9>-Footnote-23207508
Node: Tests<7>3207564
Ref: whatsnew/changelog id1023207674
Ref: 18593207674
Ref: Tests<7>-Footnote-13208059
Ref: Tests<7>-Footnote-23208115
Node: Security<11>3208171
Ref: whatsnew/changelog id1033208278
Ref: 185b3208278
Ref: Security<11>-Footnote-13208992
Ref: Security<11>-Footnote-23209048
Ref: Security<11>-Footnote-33209104
Node: Library<27>3209160
Ref: whatsnew/changelog id1043209275
Ref: 185c3209275
Ref: Library<27>-Footnote-13217493
Ref: Library<27>-Footnote-23217549
Ref: Library<27>-Footnote-33217605
Ref: Library<27>-Footnote-43217661
Ref: Library<27>-Footnote-53217717
Ref: Library<27>-Footnote-63217773
Ref: Library<27>-Footnote-73217828
Ref: Library<27>-Footnote-83217884
Ref: Library<27>-Footnote-93217940
Ref: Library<27>-Footnote-103217996
Ref: Library<27>-Footnote-113218053
Ref: Library<27>-Footnote-123218110
Ref: Library<27>-Footnote-133218167
Ref: Library<27>-Footnote-143218224
Ref: Library<27>-Footnote-153218281
Ref: Library<27>-Footnote-163218338
Ref: Library<27>-Footnote-173218395
Ref: Library<27>-Footnote-183218452
Ref: Library<27>-Footnote-193218508
Ref: Library<27>-Footnote-203218565
Ref: Library<27>-Footnote-213218622
Ref: Library<27>-Footnote-223218679
Ref: Library<27>-Footnote-233218736
Ref: Library<27>-Footnote-243218793
Ref: Library<27>-Footnote-253218850
Ref: Library<27>-Footnote-263218907
Ref: Library<27>-Footnote-273218964
Ref: Library<27>-Footnote-283219020
Ref: Library<27>-Footnote-293219077
Ref: Library<27>-Footnote-303219133
Ref: Library<27>-Footnote-313219190
Ref: Library<27>-Footnote-323219247
Ref: Library<27>-Footnote-333219304
Ref: Library<27>-Footnote-343219361
Ref: Library<27>-Footnote-353219418
Ref: Library<27>-Footnote-363219475
Ref: Library<27>-Footnote-373219531
Ref: Library<27>-Footnote-383219588
Ref: Library<27>-Footnote-393219645
Ref: Library<27>-Footnote-403219702
Ref: Library<27>-Footnote-413219759
Ref: Library<27>-Footnote-423219816
Ref: Library<27>-Footnote-433219873
Ref: Library<27>-Footnote-443219930
Ref: Library<27>-Footnote-453220002
Ref: Library<27>-Footnote-463220059
Ref: Library<27>-Footnote-473220116
Ref: Library<27>-Footnote-483220173
Ref: Library<27>-Footnote-493220229
Ref: Library<27>-Footnote-503220286
Node: Documentation<8>3220352
Ref: whatsnew/changelog id1053220476
Ref: 18673220476
Ref: Documentation<8>-Footnote-13220675
Node: Core and Builtins<24>3220731
Ref: whatsnew/changelog id1063220855
Ref: 18683220855
Ref: Core and Builtins<24>-Footnote-13224238
Ref: Core and Builtins<24>-Footnote-23224294
Ref: Core and Builtins<24>-Footnote-33224350
Ref: Core and Builtins<24>-Footnote-43224406
Ref: Core and Builtins<24>-Footnote-53224462
Ref: Core and Builtins<24>-Footnote-63224504
Ref: Core and Builtins<24>-Footnote-73224560
Ref: Core and Builtins<24>-Footnote-83224616
Ref: Core and Builtins<24>-Footnote-93224658
Ref: Core and Builtins<24>-Footnote-103224714
Ref: Core and Builtins<24>-Footnote-113224771
Ref: Core and Builtins<24>-Footnote-123224828
Ref: Core and Builtins<24>-Footnote-133224885
Ref: Core and Builtins<24>-Footnote-143224942
Ref: Core and Builtins<24>-Footnote-153224999
Ref: Core and Builtins<24>-Footnote-163225056
Ref: Core and Builtins<24>-Footnote-173225113
Ref: Core and Builtins<24>-Footnote-183225170
Ref: Core and Builtins<24>-Footnote-193225227
Ref: Core and Builtins<24>-Footnote-203225284
Ref: Core and Builtins<24>-Footnote-213225341
Ref: Core and Builtins<24>-Footnote-223225398
Ref: Core and Builtins<24>-Footnote-233225455
Ref: Core and Builtins<24>-Footnote-243225511
Node: Library<28>3225568
Ref: whatsnew/changelog id1073225697
Ref: 186b3225697
Ref: Library<28>-Footnote-13225900
Ref: Library<28>-Footnote-23225955
Node: Core and Builtins<25>3226014
Ref: whatsnew/changelog id1083226130
Ref: 186c3226130
Ref: Core and Builtins<25>-Footnote-13226776
Ref: Core and Builtins<25>-Footnote-23226832
Ref: Core and Builtins<25>-Footnote-33226888
Ref: Core and Builtins<25>-Footnote-43226944
Ref: Core and Builtins<25>-Footnote-53227000
Node: C API<9>3227056
Ref: whatsnew/changelog id1093227169
Ref: 186d3227169
Ref: C API<9>-Footnote-13227425
Ref: C API<9>-Footnote-23227481
Node: Build<9>3227537
Ref: whatsnew/changelog id1103227620
Ref: 186e3227620
Ref: Build<9>-Footnote-13228481
Ref: Build<9>-Footnote-23228537
Ref: Build<9>-Footnote-33228593
Ref: Build<9>-Footnote-43228649
Ref: Build<9>-Footnote-53228705
Ref: Build<9>-Footnote-63228761
Node: Python 3 14 0 alpha 63228817
Ref: whatsnew/changelog python-3-14-0-alpha-63228944
Ref: 186f3228944
Node: macOS<4>3229442
Ref: whatsnew/changelog id1113229528
Ref: 18703229528
Ref: macOS<4>-Footnote-13229726
Node: Windows<10>3229782
Ref: whatsnew/changelog id1123229892
Ref: 18723229892
Ref: Windows<10>-Footnote-13230080
Ref: Windows<10>-Footnote-23230136
Node: Tools/Demos<10>3230203
Ref: whatsnew/changelog id1133230313
Ref: 18733230313
Ref: Tools/Demos<10>-Footnote-13231072
Ref: Tools/Demos<10>-Footnote-23231128
Ref: Tools/Demos<10>-Footnote-33231183
Ref: Tools/Demos<10>-Footnote-43231239
Ref: Tools/Demos<10>-Footnote-53231295
Ref: Tools/Demos<10>-Footnote-63231351
Ref: Tools/Demos<10>-Footnote-73231407
Node: Tests<8>3231463
Ref: whatsnew/changelog id1143231574
Ref: 18743231574
Ref: Tests<8>-Footnote-13232291
Ref: Tests<8>-Footnote-23232347
Ref: Tests<8>-Footnote-33232403
Ref: Tests<8>-Footnote-43232459
Ref: Tests<8>-Footnote-53232515
Node: Security<12>3232571
Ref: whatsnew/changelog id1153232678
Ref: 18753232678
Ref: Security<12>-Footnote-13233004
Node: Library<29>3233060
Ref: whatsnew/changelog id1163233175
Ref: 18763233175
Ref: Library<29>-Footnote-13245882
Ref: Library<29>-Footnote-23245938
Ref: Library<29>-Footnote-33245994
Ref: Library<29>-Footnote-43246050
Ref: Library<29>-Footnote-53246106
Ref: Library<29>-Footnote-63246161
Ref: Library<29>-Footnote-73246216
Ref: Library<29>-Footnote-83246271
Ref: Library<29>-Footnote-93246326
Ref: Library<29>-Footnote-103246382
Ref: Library<29>-Footnote-113246439
Ref: Library<29>-Footnote-123246496
Ref: Library<29>-Footnote-133246553
Ref: Library<29>-Footnote-143246610
Ref: Library<29>-Footnote-153246667
Ref: Library<29>-Footnote-163246724
Ref: Library<29>-Footnote-173246781
Ref: Library<29>-Footnote-183246838
Ref: Library<29>-Footnote-193246894
Ref: Library<29>-Footnote-203246951
Ref: Library<29>-Footnote-213247008
Ref: Library<29>-Footnote-223247064
Ref: Library<29>-Footnote-233247121
Ref: Library<29>-Footnote-243247178
Ref: Library<29>-Footnote-253247235
Ref: Library<29>-Footnote-263247292
Ref: Library<29>-Footnote-273247349
Ref: Library<29>-Footnote-283247406
Ref: Library<29>-Footnote-293247462
Ref: Library<29>-Footnote-303247519
Ref: Library<29>-Footnote-313247576
Ref: Library<29>-Footnote-323247633
Ref: Library<29>-Footnote-333247690
Ref: Library<29>-Footnote-343247747
Ref: Library<29>-Footnote-353247804
Ref: Library<29>-Footnote-363247861
Ref: Library<29>-Footnote-373247918
Ref: Library<29>-Footnote-383247975
Ref: Library<29>-Footnote-393248032
Ref: Library<29>-Footnote-403248088
Ref: Library<29>-Footnote-413248145
Ref: Library<29>-Footnote-423248202
Ref: Library<29>-Footnote-433248259
Ref: Library<29>-Footnote-443248316
Ref: Library<29>-Footnote-453248372
Ref: Library<29>-Footnote-463248429
Ref: Library<29>-Footnote-473248486
Ref: Library<29>-Footnote-483248543
Ref: Library<29>-Footnote-493248599
Ref: Library<29>-Footnote-503248656
Ref: Library<29>-Footnote-513248713
Ref: Library<29>-Footnote-523248770
Ref: Library<29>-Footnote-533248827
Ref: Library<29>-Footnote-543248883
Ref: Library<29>-Footnote-553248940
Ref: Library<29>-Footnote-563248997
Ref: Library<29>-Footnote-573249054
Ref: Library<29>-Footnote-583249111
Ref: Library<29>-Footnote-593249168
Ref: Library<29>-Footnote-603249225
Ref: Library<29>-Footnote-613249282
Ref: Library<29>-Footnote-623249339
Ref: Library<29>-Footnote-633249396
Ref: Library<29>-Footnote-643249452
Ref: Library<29>-Footnote-653249509
Ref: Library<29>-Footnote-663249566
Ref: Library<29>-Footnote-673249622
Ref: Library<29>-Footnote-683249682
Ref: Library<29>-Footnote-693249738
Ref: Library<29>-Footnote-703249798
Ref: Library<29>-Footnote-713249855
Ref: Library<29>-Footnote-723249912
Node: Documentation<9>3249968
Ref: whatsnew/changelog id1173250092
Ref: 187e3250092
Ref: Documentation<9>-Footnote-13250547
Ref: Documentation<9>-Footnote-23250603
Ref: Documentation<9>-Footnote-33250659
Node: Core and Builtins<26>3250714
Ref: whatsnew/changelog id1183250838
Ref: 18823250838
Ref: Core and Builtins<26>-Footnote-13255408
Ref: Core and Builtins<26>-Footnote-23255464
Ref: Core and Builtins<26>-Footnote-33255520
Ref: Core and Builtins<26>-Footnote-43255576
Ref: Core and Builtins<26>-Footnote-53255632
Ref: Core and Builtins<26>-Footnote-63255688
Ref: Core and Builtins<26>-Footnote-73255744
Ref: Core and Builtins<26>-Footnote-83255800
Ref: Core and Builtins<26>-Footnote-93255856
Ref: Core and Builtins<26>-Footnote-103255912
Ref: Core and Builtins<26>-Footnote-113255969
Ref: Core and Builtins<26>-Footnote-123256026
Ref: Core and Builtins<26>-Footnote-133256083
Ref: Core and Builtins<26>-Footnote-143256140
Ref: Core and Builtins<26>-Footnote-153256197
Ref: Core and Builtins<26>-Footnote-163256254
Ref: Core and Builtins<26>-Footnote-173256311
Ref: Core and Builtins<26>-Footnote-183256368
Ref: Core and Builtins<26>-Footnote-193256425
Ref: Core and Builtins<26>-Footnote-203256482
Ref: Core and Builtins<26>-Footnote-213256539
Ref: Core and Builtins<26>-Footnote-223256598
Ref: Core and Builtins<26>-Footnote-233256655
Ref: Core and Builtins<26>-Footnote-243256712
Ref: Core and Builtins<26>-Footnote-253256769
Ref: Core and Builtins<26>-Footnote-263256826
Ref: Core and Builtins<26>-Footnote-273256883
Ref: Core and Builtins<26>-Footnote-283256940
Ref: Core and Builtins<26>-Footnote-293256997
Ref: Core and Builtins<26>-Footnote-303257040
Ref: Core and Builtins<26>-Footnote-313257097
Ref: Core and Builtins<26>-Footnote-323257153
Node: Library<30>3257210
Ref: whatsnew/changelog id1193257339
Ref: 18843257339
Ref: Library<30>-Footnote-13257482
Node: Core and Builtins<27>3257538
Ref: whatsnew/changelog id1203257657
Ref: 18853257657
Ref: Core and Builtins<27>-Footnote-13260355
Ref: Core and Builtins<27>-Footnote-23260411
Ref: Core and Builtins<27>-Footnote-33260467
Ref: Core and Builtins<27>-Footnote-43260523
Ref: Core and Builtins<27>-Footnote-53260579
Ref: Core and Builtins<27>-Footnote-63260635
Ref: Core and Builtins<27>-Footnote-73260691
Ref: Core and Builtins<27>-Footnote-83260747
Ref: Core and Builtins<27>-Footnote-93260803
Ref: Core and Builtins<27>-Footnote-103260859
Ref: Core and Builtins<27>-Footnote-113260916
Ref: Core and Builtins<27>-Footnote-123260973
Ref: Core and Builtins<27>-Footnote-133261029
Ref: Core and Builtins<27>-Footnote-143261086
Node: Library<31>3261143
Ref: whatsnew/changelog id1213261272
Ref: 18873261272
Ref: Library<31>-Footnote-13261533
Node: Core and Builtins<28>3261589
Ref: whatsnew/changelog id1223261706
Ref: 18883261706
Ref: Core and Builtins<28>-Footnote-13261903
Node: C API<10>3261968
Ref: whatsnew/changelog id1233262083
Ref: 18893262083
Ref: C API<10>-Footnote-13264465
Ref: C API<10>-Footnote-23264521
Ref: C API<10>-Footnote-33264577
Ref: C API<10>-Footnote-43264633
Ref: C API<10>-Footnote-53264686
Node: Build<10>3264741
Ref: whatsnew/changelog id1243264826
Ref: 188b3264826
Ref: Build<10>-Footnote-13265949
Ref: Build<10>-Footnote-23266005
Ref: Build<10>-Footnote-33266061
Ref: Build<10>-Footnote-43266117
Ref: Build<10>-Footnote-53266173
Ref: Build<10>-Footnote-63266229
Ref: Build<10>-Footnote-73266285
Node: Python 3 14 0 alpha 53266340
Ref: whatsnew/changelog python-3-14-0-alpha-53266467
Ref: 188c3266467
Node: macOS<5>3266983
Ref: whatsnew/changelog id1253267073
Ref: 188d3267073
Ref: macOS<5>-Footnote-13267204
Node: Tools/Demos<11>3267259
Ref: whatsnew/changelog id1263267366
Ref: 188e3267366
Ref: Tools/Demos<11>-Footnote-13267665
Ref: Tools/Demos<11>-Footnote-23267721
Node: Tests<9>3267777
Ref: whatsnew/changelog id1273267888
Ref: 188f3267888
Ref: Tests<9>-Footnote-13268620
Ref: Tests<9>-Footnote-23268676
Ref: Tests<9>-Footnote-33268732
Node: Security<13>3268788
Ref: whatsnew/changelog id1283268895
Ref: 18903268895
Ref: Security<13>-Footnote-13270452
Ref: Security<13>-Footnote-23270508
Ref: Security<13>-Footnote-33270569
Ref: Security<13>-Footnote-43270625
Ref: Security<13>-Footnote-53270680
Node: Library<32>3270736
Ref: whatsnew/changelog id1293270842
Ref: 18913270842
Ref: Library<32>-Footnote-13282482
Ref: Library<32>-Footnote-23282538
Ref: Library<32>-Footnote-33282594
Ref: Library<32>-Footnote-43282650
Ref: Library<32>-Footnote-53282706
Ref: Library<32>-Footnote-63282762
Ref: Library<32>-Footnote-73282818
Ref: Library<32>-Footnote-83282874
Ref: Library<32>-Footnote-93282930
Ref: Library<32>-Footnote-103282986
Ref: Library<32>-Footnote-113283043
Ref: Library<32>-Footnote-123283100
Ref: Library<32>-Footnote-133283157
Ref: Library<32>-Footnote-143283214
Ref: Library<32>-Footnote-153283271
Ref: Library<32>-Footnote-163283328
Ref: Library<32>-Footnote-173283385
Ref: Library<32>-Footnote-183283442
Ref: Library<32>-Footnote-193283499
Ref: Library<32>-Footnote-203283556
Ref: Library<32>-Footnote-213283613
Ref: Library<32>-Footnote-223283670
Ref: Library<32>-Footnote-233283726
Ref: Library<32>-Footnote-243283783
Ref: Library<32>-Footnote-253283840
Ref: Library<32>-Footnote-263283897
Ref: Library<32>-Footnote-273283954
Ref: Library<32>-Footnote-283284011
Ref: Library<32>-Footnote-293284068
Ref: Library<32>-Footnote-303284125
Ref: Library<32>-Footnote-313284182
Ref: Library<32>-Footnote-323284239
Ref: Library<32>-Footnote-333284296
Ref: Library<32>-Footnote-343284353
Ref: Library<32>-Footnote-353284410
Ref: Library<32>-Footnote-363284467
Ref: Library<32>-Footnote-373284524
Ref: Library<32>-Footnote-383284581
Ref: Library<32>-Footnote-393284638
Ref: Library<32>-Footnote-403284695
Ref: Library<32>-Footnote-413284752
Ref: Library<32>-Footnote-423284809
Ref: Library<32>-Footnote-433284866
Ref: Library<32>-Footnote-443284923
Ref: Library<32>-Footnote-453284980
Ref: Library<32>-Footnote-463285037
Ref: Library<32>-Footnote-473285094
Ref: Library<32>-Footnote-483285154
Ref: Library<32>-Footnote-493285210
Ref: Library<32>-Footnote-503285267
Ref: Library<32>-Footnote-513285323
Ref: Library<32>-Footnote-523285380
Ref: Library<32>-Footnote-533285437
Ref: Library<32>-Footnote-543285494
Ref: Library<32>-Footnote-553285551
Ref: Library<32>-Footnote-563285608
Ref: Library<32>-Footnote-573285665
Ref: Library<32>-Footnote-583285722
Ref: Library<32>-Footnote-593285779
Ref: Library<32>-Footnote-603285836
Ref: Library<32>-Footnote-613285893
Ref: Library<32>-Footnote-623285950
Ref: Library<32>-Footnote-633286006
Ref: Library<32>-Footnote-643286063
Ref: Library<32>-Footnote-653286120
Ref: Library<32>-Footnote-663286177
Ref: Library<32>-Footnote-673286233
Ref: Library<32>-Footnote-683286290
Ref: Library<32>-Footnote-693286347
Ref: Library<32>-Footnote-703286403
Node: IDLE<6>3286469
Ref: whatsnew/changelog id1303286580
Ref: 189d3286580
Ref: IDLE<6>-Footnote-13286802
Node: Documentation<10>3286858
Ref: whatsnew/changelog id1313286979
Ref: 189e3286979
Ref: Documentation<10>-Footnote-13287403
Ref: Documentation<10>-Footnote-23287459
Node: Core and Builtins<29>3287514
Ref: whatsnew/changelog id1323287639
Ref: 18a03287639
Ref: Core and Builtins<29>-Footnote-13288753
Ref: Core and Builtins<29>-Footnote-23288809
Ref: Core and Builtins<29>-Footnote-33288865
Ref: Core and Builtins<29>-Footnote-43288921
Ref: Core and Builtins<29>-Footnote-53288977
Ref: Core and Builtins<29>-Footnote-63289033
Ref: Core and Builtins<29>-Footnote-73289089
Ref: Core and Builtins<29>-Footnote-83289145
Ref: Core and Builtins<29>-Footnote-93289201
Node: Library<33>3289257
Ref: whatsnew/changelog id1333289386
Ref: 18a33289386
Ref: Library<33>-Footnote-13289585
Node: Core and Builtins<30>3289641
Ref: whatsnew/changelog id1343289760
Ref: 18a43289760
Ref: Core and Builtins<30>-Footnote-13294314
Ref: Core and Builtins<30>-Footnote-23294370
Ref: Core and Builtins<30>-Footnote-33294426
Ref: Core and Builtins<30>-Footnote-43294482
Ref: Core and Builtins<30>-Footnote-53294538
Ref: Core and Builtins<30>-Footnote-63294594
Ref: Core and Builtins<30>-Footnote-73294650
Ref: Core and Builtins<30>-Footnote-83294706
Ref: Core and Builtins<30>-Footnote-93294762
Ref: Core and Builtins<30>-Footnote-103294818
Ref: Core and Builtins<30>-Footnote-113294875
Ref: Core and Builtins<30>-Footnote-123294932
Ref: Core and Builtins<30>-Footnote-133294989
Ref: Core and Builtins<30>-Footnote-143295046
Ref: Core and Builtins<30>-Footnote-153295103
Ref: Core and Builtins<30>-Footnote-163295160
Ref: Core and Builtins<30>-Footnote-173295217
Ref: Core and Builtins<30>-Footnote-183295274
Ref: Core and Builtins<30>-Footnote-193295331
Ref: Core and Builtins<30>-Footnote-203295388
Ref: Core and Builtins<30>-Footnote-213295445
Ref: Core and Builtins<30>-Footnote-223295502
Ref: Core and Builtins<30>-Footnote-233295559
Ref: Core and Builtins<30>-Footnote-243295616
Node: Library<34>3295673
Ref: whatsnew/changelog id1353295802
Ref: 18ad3295802
Ref: Library<34>-Footnote-13296063
Node: Core and Builtins<31>3296119
Ref: whatsnew/changelog id1363296238
Ref: 18ae3296238
Ref: Core and Builtins<31>-Footnote-13296522
Node: Library<35>3296578
Ref: whatsnew/changelog id1373296695
Ref: 18af3296695
Ref: Library<35>-Footnote-13296874
Node: C API<11>3296930
Ref: whatsnew/changelog id1383297035
Ref: 18b03297035
Ref: C API<11>-Footnote-13300234
Ref: C API<11>-Footnote-23300290
Ref: C API<11>-Footnote-33300345
Ref: C API<11>-Footnote-43300400
Ref: C API<11>-Footnote-53300456
Ref: C API<11>-Footnote-63300512
Ref: C API<11>-Footnote-73300554
Ref: C API<11>-Footnote-83300610
Ref: C API<11>-Footnote-93300652
Ref: C API<11>-Footnote-103300708
Ref: C API<11>-Footnote-113300765
Ref: C API<11>-Footnote-123300822
Ref: C API<11>-Footnote-133300876
Ref: C API<11>-Footnote-143300933
Ref: C API<11>-Footnote-153300990
Node: Build<11>3301033
Ref: whatsnew/changelog id1393301118
Ref: 18b33301118
Ref: Build<11>-Footnote-13301450
Ref: Build<11>-Footnote-23301506
Node: Python 3 14 0 alpha 43301562
Ref: whatsnew/changelog python-3-14-0-alpha-43301689
Ref: 18b43301689
Node: macOS<6>3302103
Ref: whatsnew/changelog id1403302193
Ref: 18b53302193
Ref: macOS<6>-Footnote-13302397
Node: Tools/Demos<12>3302453
Ref: whatsnew/changelog id1413302561
Ref: 18b63302561
Ref: Tools/Demos<12>-Footnote-13302815
Node: Tests<10>3302871
Ref: whatsnew/changelog id1423302982
Ref: 18b73302982
Ref: Tests<10>-Footnote-13303225
Node: Library<36>3303281
Ref: whatsnew/changelog id1433303398
Ref: 18b83303398
Ref: Library<36>-Footnote-13311948
Ref: Library<36>-Footnote-23312004
Ref: Library<36>-Footnote-33312059
Ref: Library<36>-Footnote-43312115
Ref: Library<36>-Footnote-53312171
Ref: Library<36>-Footnote-63312227
Ref: Library<36>-Footnote-73312283
Ref: Library<36>-Footnote-83312339
Ref: Library<36>-Footnote-93312395
Ref: Library<36>-Footnote-103312451
Ref: Library<36>-Footnote-113312508
Ref: Library<36>-Footnote-123312565
Ref: Library<36>-Footnote-133312622
Ref: Library<36>-Footnote-143312678
Ref: Library<36>-Footnote-153312735
Ref: Library<36>-Footnote-163312792
Ref: Library<36>-Footnote-173312849
Ref: Library<36>-Footnote-183312906
Ref: Library<36>-Footnote-193312963
Ref: Library<36>-Footnote-203313020
Ref: Library<36>-Footnote-213313077
Ref: Library<36>-Footnote-223313134
Ref: Library<36>-Footnote-233313190
Ref: Library<36>-Footnote-243313247
Ref: Library<36>-Footnote-253313304
Ref: Library<36>-Footnote-263313352
Ref: Library<36>-Footnote-273313397
Ref: Library<36>-Footnote-283313454
Ref: Library<36>-Footnote-293313511
Ref: Library<36>-Footnote-303313568
Ref: Library<36>-Footnote-313313624
Ref: Library<36>-Footnote-323313681
Ref: Library<36>-Footnote-333313737
Ref: Library<36>-Footnote-343313794
Ref: Library<36>-Footnote-353313851
Ref: Library<36>-Footnote-363313908
Ref: Library<36>-Footnote-373313965
Ref: Library<36>-Footnote-383314022
Ref: Library<36>-Footnote-393314079
Ref: Library<36>-Footnote-403314136
Ref: Library<36>-Footnote-413314193
Ref: Library<36>-Footnote-423314250
Ref: Library<36>-Footnote-433314307
Ref: Library<36>-Footnote-443314364
Ref: Library<36>-Footnote-453314421
Node: Core and Builtins<32>3314477
Ref: whatsnew/changelog id1443314596
Ref: 18bd3314596
Ref: Core and Builtins<32>-Footnote-13315408
Ref: Core and Builtins<32>-Footnote-23315464
Ref: Core and Builtins<32>-Footnote-33315520
Ref: Core and Builtins<32>-Footnote-43315576
Ref: Core and Builtins<32>-Footnote-53315632
Node: Library<37>3315688
Ref: whatsnew/changelog id1453315817
Ref: 18be3315817
Ref: Library<37>-Footnote-13316069
Ref: Library<37>-Footnote-23316125
Node: Core and Builtins<33>3316184
Ref: whatsnew/changelog id1463316303
Ref: 18bf3316303
Ref: Core and Builtins<33>-Footnote-13317421
Ref: Core and Builtins<33>-Footnote-23317477
Ref: Core and Builtins<33>-Footnote-33317533
Ref: Core and Builtins<33>-Footnote-43317589
Ref: Core and Builtins<33>-Footnote-53317645
Node: Library<38>3317701
Ref: whatsnew/changelog id1473317830
Ref: 18c13317830
Ref: Library<38>-Footnote-13318097
Node: Core and Builtins<34>3318153
Ref: whatsnew/changelog id1483318270
Ref: 18c23318270
Ref: Core and Builtins<34>-Footnote-13319731
Ref: Core and Builtins<34>-Footnote-23319787
Ref: Core and Builtins<34>-Footnote-33319842
Ref: Core and Builtins<34>-Footnote-43319898
Ref: Core and Builtins<34>-Footnote-53319978
Ref: Core and Builtins<34>-Footnote-63320034
Ref: Core and Builtins<34>-Footnote-73320090
Ref: Core and Builtins<34>-Footnote-83320146
Node: C API<12>3320202
Ref: whatsnew/changelog id1493320317
Ref: 18c63320317
Ref: C API<12>-Footnote-13321122
Ref: C API<12>-Footnote-23321178
Ref: C API<12>-Footnote-33321234
Ref: C API<12>-Footnote-43321290
Node: Build<12>3321346
Ref: whatsnew/changelog id1503321431
Ref: 18c83321431
Ref: Build<12>-Footnote-13322940
Ref: Build<12>-Footnote-23322996
Ref: Build<12>-Footnote-33323052
Ref: Build<12>-Footnote-43323108
Ref: Build<12>-Footnote-53323164
Ref: Build<12>-Footnote-63323219
Ref: Build<12>-Footnote-73323275
Ref: Build<12>-Footnote-83323331
Ref: Build<12>-Footnote-93323387
Ref: Build<12>-Footnote-103323435
Node: Python 3 14 0 alpha 33323492
Ref: whatsnew/changelog python-3-14-0-alpha-33323619
Ref: 18c93323619
Node: Windows<11>3324032
Ref: whatsnew/changelog id1513324125
Ref: 18ca3324125
Ref: Windows<11>-Footnote-13324524
Ref: Windows<11>-Footnote-23324580
Node: Tools/Demos<13>3324636
Ref: whatsnew/changelog id1523324747
Ref: 18cb3324747
Ref: Tools/Demos<13>-Footnote-13324936
Node: Tests<11>3324992
Ref: whatsnew/changelog id1533325104
Ref: 18cc3325104
Ref: Tests<11>-Footnote-13325773
Ref: Tests<11>-Footnote-23325829
Ref: Tests<11>-Footnote-33325885
Ref: Tests<11>-Footnote-43325941
Ref: Tests<11>-Footnote-53325997
Node: Security<14>3326053
Ref: whatsnew/changelog id1543326161
Ref: 18cd3326161
Ref: Security<14>-Footnote-13326491
Node: Library<39>3326547
Ref: whatsnew/changelog id1553326663
Ref: 18ce3326663
Ref: Library<39>-Footnote-13337230
Ref: Library<39>-Footnote-23337286
Ref: Library<39>-Footnote-33337342
Ref: Library<39>-Footnote-43337398
Ref: Library<39>-Footnote-53337454
Ref: Library<39>-Footnote-63337510
Ref: Library<39>-Footnote-73337566
Ref: Library<39>-Footnote-83337622
Ref: Library<39>-Footnote-93337678
Ref: Library<39>-Footnote-103337733
Ref: Library<39>-Footnote-113337790
Ref: Library<39>-Footnote-123337847
Ref: Library<39>-Footnote-133337904
Ref: Library<39>-Footnote-143337961
Ref: Library<39>-Footnote-153338018
Ref: Library<39>-Footnote-163338075
Ref: Library<39>-Footnote-173338132
Ref: Library<39>-Footnote-183338188
Ref: Library<39>-Footnote-193338245
Ref: Library<39>-Footnote-203338302
Ref: Library<39>-Footnote-213338359
Ref: Library<39>-Footnote-223338416
Ref: Library<39>-Footnote-233338473
Ref: Library<39>-Footnote-243338530
Ref: Library<39>-Footnote-253338587
Ref: Library<39>-Footnote-263338644
Ref: Library<39>-Footnote-273338701
Ref: Library<39>-Footnote-283338758
Ref: Library<39>-Footnote-293338815
Ref: Library<39>-Footnote-303338872
Ref: Library<39>-Footnote-313338929
Ref: Library<39>-Footnote-323338986
Ref: Library<39>-Footnote-333339043
Ref: Library<39>-Footnote-343339100
Ref: Library<39>-Footnote-353339157
Ref: Library<39>-Footnote-363339214
Ref: Library<39>-Footnote-373339271
Ref: Library<39>-Footnote-383339328
Ref: Library<39>-Footnote-393339385
Ref: Library<39>-Footnote-403339442
Ref: Library<39>-Footnote-413339499
Ref: Library<39>-Footnote-423339556
Ref: Library<39>-Footnote-433339613
Ref: Library<39>-Footnote-443339670
Ref: Library<39>-Footnote-453339727
Ref: Library<39>-Footnote-463339784
Ref: Library<39>-Footnote-473339840
Ref: Library<39>-Footnote-483339897
Ref: Library<39>-Footnote-493339954
Ref: Library<39>-Footnote-503340011
Ref: Library<39>-Footnote-513340068
Ref: Library<39>-Footnote-523340124
Ref: Library<39>-Footnote-533340181
Ref: Library<39>-Footnote-543340237
Ref: Library<39>-Footnote-553340294
Ref: Library<39>-Footnote-563340351
Ref: Library<39>-Footnote-573340410
Ref: Library<39>-Footnote-583340470
Ref: Library<39>-Footnote-593340527
Ref: Library<39>-Footnote-603340584
Ref: Library<39>-Footnote-613340641
Ref: Library<39>-Footnote-623340697
Ref: Library<39>-Footnote-633340753
Node: Documentation<11>3340809
Ref: whatsnew/changelog id1563340934
Ref: 18d63340934
Ref: Documentation<11>-Footnote-13341124
Node: Core and Builtins<35>3341180
Ref: whatsnew/changelog id1573341305
Ref: 18d83341305
Ref: Core and Builtins<35>-Footnote-13342860
Ref: Core and Builtins<35>-Footnote-23342916
Ref: Core and Builtins<35>-Footnote-33342972
Ref: Core and Builtins<35>-Footnote-43343028
Ref: Core and Builtins<35>-Footnote-53343084
Ref: Core and Builtins<35>-Footnote-63343140
Ref: Core and Builtins<35>-Footnote-73343196
Ref: Core and Builtins<35>-Footnote-83343252
Ref: Core and Builtins<35>-Footnote-93343308
Ref: Core and Builtins<35>-Footnote-103343364
Node: Library<40>3343421
Ref: whatsnew/changelog id1583343550
Ref: 18db3343550
Ref: Library<40>-Footnote-13344140
Node: Core and Builtins<36>3344196
Ref: whatsnew/changelog id1593344313
Ref: 18dc3344313
Ref: Core and Builtins<36>-Footnote-13347079
Ref: Core and Builtins<36>-Footnote-23347135
Ref: Core and Builtins<36>-Footnote-33347191
Ref: Core and Builtins<36>-Footnote-43347247
Ref: Core and Builtins<36>-Footnote-53347303
Ref: Core and Builtins<36>-Footnote-63347359
Ref: Core and Builtins<36>-Footnote-73347415
Ref: Core and Builtins<36>-Footnote-83347471
Ref: Core and Builtins<36>-Footnote-93347527
Ref: Core and Builtins<36>-Footnote-103347583
Ref: Core and Builtins<36>-Footnote-113347640
Ref: Core and Builtins<36>-Footnote-123347697
Ref: Core and Builtins<36>-Footnote-133347754
Ref: Core and Builtins<36>-Footnote-143347811
Ref: Core and Builtins<36>-Footnote-153347867
Ref: Core and Builtins<36>-Footnote-163347924
Node: C API<13>3347981
Ref: whatsnew/changelog id1603348096
Ref: 18e13348096
Ref: C API<13>-Footnote-13350442
Ref: C API<13>-Footnote-23350498
Ref: C API<13>-Footnote-33350554
Ref: C API<13>-Footnote-43350610
Ref: C API<13>-Footnote-53350666
Ref: C API<13>-Footnote-63350722
Ref: C API<13>-Footnote-73350778
Ref: C API<13>-Footnote-83350834
Ref: C API<13>-Footnote-93350890
Ref: C API<13>-Footnote-103350932
Node: Build<13>3350989
Ref: whatsnew/changelog id1613351074
Ref: 18e73351074
Ref: Build<13>-Footnote-13351621
Ref: Build<13>-Footnote-23351677
Ref: Build<13>-Footnote-33351733
Ref: Build<13>-Footnote-43351789
Ref: Build<13>-Footnote-53351845
Node: Python 3 14 0 alpha 23351901
Ref: whatsnew/changelog python-3-14-0-alpha-23352028
Ref: 18e83352028
Node: Windows<12>3352533
Ref: whatsnew/changelog id1623352626
Ref: 18e93352626
Ref: Windows<12>-Footnote-13353734
Ref: Windows<12>-Footnote-23353790
Ref: Windows<12>-Footnote-33353846
Ref: Windows<12>-Footnote-43353902
Ref: Windows<12>-Footnote-53353958
Ref: Windows<12>-Footnote-63354014
Ref: Windows<12>-Footnote-73354070
Ref: Windows<12>-Footnote-83354126
Ref: Windows<12>-Footnote-93354182
Node: Tools/Demos<14>3354238
Ref: whatsnew/changelog id1633354349
Ref: 18ea3354349
Ref: Tools/Demos<14>-Footnote-13354685
Ref: Tools/Demos<14>-Footnote-23354741
Node: Tests<12>3354797
Ref: whatsnew/changelog id1643354909
Ref: 18eb3354909
Ref: Tests<12>-Footnote-13355309
Ref: Tests<12>-Footnote-23355365
Ref: Tests<12>-Footnote-33355421
Node: Security<15>3355477
Ref: whatsnew/changelog id1653355585
Ref: 18ec3355585
Ref: Security<15>-Footnote-13355706
Node: Library<41>3355762
Ref: whatsnew/changelog id1663355878
Ref: 18ed3355878
Ref: Library<41>-Footnote-13374161
Ref: Library<41>-Footnote-23374216
Ref: Library<41>-Footnote-33374272
Ref: Library<41>-Footnote-43374327
Ref: Library<41>-Footnote-53374383
Ref: Library<41>-Footnote-63374439
Ref: Library<41>-Footnote-73374495
Ref: Library<41>-Footnote-83374551
Ref: Library<41>-Footnote-93374607
Ref: Library<41>-Footnote-103374663
Ref: Library<41>-Footnote-113374720
Ref: Library<41>-Footnote-123374777
Ref: Library<41>-Footnote-133374834
Ref: Library<41>-Footnote-143374891
Ref: Library<41>-Footnote-153374948
Ref: Library<41>-Footnote-163375005
Ref: Library<41>-Footnote-173375062
Ref: Library<41>-Footnote-183375119
Ref: Library<41>-Footnote-193375176
Ref: Library<41>-Footnote-203375233
Ref: Library<41>-Footnote-213375290
Ref: Library<41>-Footnote-223375347
Ref: Library<41>-Footnote-233375403
Ref: Library<41>-Footnote-243375463
Ref: Library<41>-Footnote-253375520
Ref: Library<41>-Footnote-263375577
Ref: Library<41>-Footnote-273375634
Ref: Library<41>-Footnote-283375691
Ref: Library<41>-Footnote-293375748
Ref: Library<41>-Footnote-303375805
Ref: Library<41>-Footnote-313375862
Ref: Library<41>-Footnote-323375919
Ref: Library<41>-Footnote-333375976
Ref: Library<41>-Footnote-343376033
Ref: Library<41>-Footnote-353376090
Ref: Library<41>-Footnote-363376147
Ref: Library<41>-Footnote-373376204
Ref: Library<41>-Footnote-383376261
Ref: Library<41>-Footnote-393376318
Ref: Library<41>-Footnote-403376375
Ref: Library<41>-Footnote-413376432
Ref: Library<41>-Footnote-423376489
Ref: Library<41>-Footnote-433376546
Ref: Library<41>-Footnote-443376603
Ref: Library<41>-Footnote-453376660
Ref: Library<41>-Footnote-463376717
Ref: Library<41>-Footnote-473376774
Ref: Library<41>-Footnote-483376834
Ref: Library<41>-Footnote-493376891
Ref: Library<41>-Footnote-503376948
Ref: Library<41>-Footnote-513377005
Ref: Library<41>-Footnote-523377062
Ref: Library<41>-Footnote-533377119
Ref: Library<41>-Footnote-543377176
Ref: Library<41>-Footnote-553377233
Ref: Library<41>-Footnote-563377290
Ref: Library<41>-Footnote-573377347
Ref: Library<41>-Footnote-583377404
Ref: Library<41>-Footnote-593377460
Ref: Library<41>-Footnote-603377517
Ref: Library<41>-Footnote-613377574
Ref: Library<41>-Footnote-623377631
Ref: Library<41>-Footnote-633377688
Ref: Library<41>-Footnote-643377745
Ref: Library<41>-Footnote-653377802
Ref: Library<41>-Footnote-663377858
Ref: Library<41>-Footnote-673377915
Ref: Library<41>-Footnote-683377972
Ref: Library<41>-Footnote-693378029
Ref: Library<41>-Footnote-703378086
Ref: Library<41>-Footnote-713378143
Ref: Library<41>-Footnote-723378200
Ref: Library<41>-Footnote-733378257
Ref: Library<41>-Footnote-743378314
Ref: Library<41>-Footnote-753378371
Ref: Library<41>-Footnote-763378428
Ref: Library<41>-Footnote-773378485
Ref: Library<41>-Footnote-783378542
Ref: Library<41>-Footnote-793378598
Ref: Library<41>-Footnote-803378655
Ref: Library<41>-Footnote-813378712
Ref: Library<41>-Footnote-823378769
Ref: Library<41>-Footnote-833378812
Ref: Library<41>-Footnote-843378868
Ref: Library<41>-Footnote-853378924
Ref: Library<41>-Footnote-863378980
Ref: Library<41>-Footnote-873379037
Ref: Library<41>-Footnote-883379093
Ref: Library<41>-Footnote-893379150
Ref: Library<41>-Footnote-903379206
Ref: Library<41>-Footnote-913379266
Ref: Library<41>-Footnote-923379323
Ref: Library<41>-Footnote-933379380
Ref: Library<41>-Footnote-943379437
Ref: Library<41>-Footnote-953379493
Ref: Library<41>-Footnote-963379550
Ref: Library<41>-Footnote-973379607
Ref: Library<41>-Footnote-983379663
Ref: Library<41>-Footnote-993379720
Ref: Library<41>-Footnote-1003379777
Ref: Library<41>-Footnote-1013379835
Ref: Library<41>-Footnote-1023379892
Ref: Library<41>-Footnote-1033379959
Node: Documentation<12>3380016
Ref: whatsnew/changelog id1673380141
Ref: 18fd3380141
Ref: Documentation<12>-Footnote-13380689
Ref: Documentation<12>-Footnote-23380745
Ref: Documentation<12>-Footnote-33380801
Node: Core and Builtins<37>3380856
Ref: whatsnew/changelog id1683380981
Ref: 18fe3380981
Ref: Core and Builtins<37>-Footnote-13381550
Ref: Core and Builtins<37>-Footnote-23381606
Ref: Core and Builtins<37>-Footnote-33381662
Node: Library<42>3381718
Ref: whatsnew/changelog id1693381847
Ref: 18ff3381847
Ref: Library<42>-Footnote-13382113
Node: Core and Builtins<38>3382169
Ref: whatsnew/changelog id1703382288
Ref: 19003382288
Ref: Core and Builtins<38>-Footnote-13382712
Ref: Core and Builtins<38>-Footnote-23382768
Node: Library<43>3382824
Ref: whatsnew/changelog id1713382953
Ref: 19013382953
Ref: Library<43>-Footnote-13383255
Node: Core and Builtins<39>3383311
Ref: whatsnew/changelog id1723383430
Ref: 19023383430
Ref: Core and Builtins<39>-Footnote-13388113
Ref: Core and Builtins<39>-Footnote-23388169
Ref: Core and Builtins<39>-Footnote-33388225
Ref: Core and Builtins<39>-Footnote-43388281
Ref: Core and Builtins<39>-Footnote-53388337
Ref: Core and Builtins<39>-Footnote-63388393
Ref: Core and Builtins<39>-Footnote-73388449
Ref: Core and Builtins<39>-Footnote-83388505
Ref: Core and Builtins<39>-Footnote-93388561
Ref: Core and Builtins<39>-Footnote-103388616
Ref: Core and Builtins<39>-Footnote-113388673
Ref: Core and Builtins<39>-Footnote-123388730
Ref: Core and Builtins<39>-Footnote-133388787
Ref: Core and Builtins<39>-Footnote-143388844
Ref: Core and Builtins<39>-Footnote-153388901
Ref: Core and Builtins<39>-Footnote-163388958
Ref: Core and Builtins<39>-Footnote-173389015
Ref: Core and Builtins<39>-Footnote-183389072
Ref: Core and Builtins<39>-Footnote-193389129
Ref: Core and Builtins<39>-Footnote-203389186
Ref: Core and Builtins<39>-Footnote-213389243
Ref: Core and Builtins<39>-Footnote-223389300
Ref: Core and Builtins<39>-Footnote-233389357
Ref: Core and Builtins<39>-Footnote-243389414
Ref: Core and Builtins<39>-Footnote-253389471
Ref: Core and Builtins<39>-Footnote-263389528
Ref: Core and Builtins<39>-Footnote-273389585
Node: Library<44>3389642
Ref: whatsnew/changelog id1733389759
Ref: 19043389759
Ref: Library<44>-Footnote-13390109
Ref: Library<44>-Footnote-23390165
Node: C API<14>3390221
Ref: whatsnew/changelog id1743390326
Ref: 19053390326
Ref: C API<14>-Footnote-13391341
Ref: C API<14>-Footnote-23391397
Ref: C API<14>-Footnote-33391453
Ref: C API<14>-Footnote-43391509
Ref: C API<14>-Footnote-53391565
Ref: C API<14>-Footnote-63391607
Ref: C API<14>-Footnote-73391663
Node: Build<14>3391719
Ref: whatsnew/changelog id1753391804
Ref: 19063391804
Ref: Build<14>-Footnote-13393416
Ref: Build<14>-Footnote-23393472
Ref: Build<14>-Footnote-33393528
Ref: Build<14>-Footnote-43393584
Ref: Build<14>-Footnote-53393639
Ref: Build<14>-Footnote-63393695
Ref: Build<14>-Footnote-73393751
Ref: Build<14>-Footnote-83393807
Ref: Build<14>-Footnote-93393863
Ref: Build<14>-Footnote-103393919
Ref: Build<14>-Footnote-113393985
Ref: Build<14>-Footnote-123394041
Ref: Build<14>-Footnote-133394098
Node: Python 3 14 0 alpha 13394155
Ref: whatsnew/changelog python-3-14-0-alpha-13394281
Ref: 19073394281
Node: macOS<7>3395138
Ref: whatsnew/changelog id1763395224
Ref: 19083395224
Ref: macOS<7>-Footnote-13395532
Ref: macOS<7>-Footnote-23395588
Ref: macOS<7>-Footnote-33395644
Node: Windows<13>3395700
Ref: whatsnew/changelog id1773395810
Ref: 19093395810
Ref: Windows<13>-Footnote-13397638
Ref: Windows<13>-Footnote-23397694
Ref: Windows<13>-Footnote-33397750
Ref: Windows<13>-Footnote-43397806
Ref: Windows<13>-Footnote-53397862
Ref: Windows<13>-Footnote-63397918
Ref: Windows<13>-Footnote-73397974
Ref: Windows<13>-Footnote-83398030
Ref: Windows<13>-Footnote-93398086
Ref: Windows<13>-Footnote-103398142
Ref: Windows<13>-Footnote-113398199
Ref: Windows<13>-Footnote-123398256
Ref: Windows<13>-Footnote-133398313
Ref: Windows<13>-Footnote-143398370
Ref: Windows<13>-Footnote-153398427
Ref: Windows<13>-Footnote-163398484
Node: Tools/Demos<15>3398540
Ref: whatsnew/changelog id1783398651
Ref: 190a3398651
Ref: Tools/Demos<15>-Footnote-13398857
Node: Tests<13>3398913
Ref: whatsnew/changelog id1793399025
Ref: 190b3399025
Ref: Tests<13>-Footnote-13402107
Ref: Tests<13>-Footnote-23402163
Ref: Tests<13>-Footnote-33402219
Ref: Tests<13>-Footnote-43402275
Ref: Tests<13>-Footnote-53402331
Ref: Tests<13>-Footnote-63402387
Ref: Tests<13>-Footnote-73402443
Ref: Tests<13>-Footnote-83402498
Ref: Tests<13>-Footnote-93402553
Ref: Tests<13>-Footnote-103402609
Ref: Tests<13>-Footnote-113402666
Ref: Tests<13>-Footnote-123402723
Ref: Tests<13>-Footnote-133402780
Ref: Tests<13>-Footnote-143402837
Ref: Tests<13>-Footnote-153402894
Ref: Tests<13>-Footnote-163402951
Ref: Tests<13>-Footnote-173403008
Ref: Tests<13>-Footnote-183403065
Node: Security<16>3403122
Ref: whatsnew/changelog id1803403230
Ref: 190f3403230
Ref: Security<16>-Footnote-13405541
Ref: Security<16>-Footnote-23405597
Ref: Security<16>-Footnote-33405653
Ref: Security<16>-Footnote-43405709
Ref: Security<16>-Footnote-53405765
Ref: Security<16>-Footnote-63405821
Ref: Security<16>-Footnote-73405877
Ref: Security<16>-Footnote-83405933
Ref: Security<16>-Footnote-93405989
Ref: Security<16>-Footnote-103406045
Ref: Security<16>-Footnote-113406102
Ref: Security<16>-Footnote-123406159
Ref: Security<16>-Footnote-133406216
Ref: Security<16>-Footnote-143406273
Node: Library<45>3406329
Ref: whatsnew/changelog id1813406435
Ref: 19103406435
Ref: Library<45>-Footnote-13461688
Ref: Library<45>-Footnote-23461744
Ref: Library<45>-Footnote-33461800
Ref: Library<45>-Footnote-43461855
Ref: Library<45>-Footnote-53461911
Ref: Library<45>-Footnote-63461966
Ref: Library<45>-Footnote-73462022
Ref: Library<45>-Footnote-83462078
Ref: Library<45>-Footnote-93462134
Ref: Library<45>-Footnote-103462190
Ref: Library<45>-Footnote-113462246
Ref: Library<45>-Footnote-123462303
Ref: Library<45>-Footnote-133462360
Ref: Library<45>-Footnote-143462417
Ref: Library<45>-Footnote-153462474
Ref: Library<45>-Footnote-163462531
Ref: Library<45>-Footnote-173462587
Ref: Library<45>-Footnote-183462644
Ref: Library<45>-Footnote-193462700
Ref: Library<45>-Footnote-203462757
Ref: Library<45>-Footnote-213462800
Ref: Library<45>-Footnote-223462857
Ref: Library<45>-Footnote-233462914
Ref: Library<45>-Footnote-243462970
Ref: Library<45>-Footnote-253463027
Ref: Library<45>-Footnote-263463083
Ref: Library<45>-Footnote-273463140
Ref: Library<45>-Footnote-283463196
Ref: Library<45>-Footnote-293463253
Ref: Library<45>-Footnote-303463310
Ref: Library<45>-Footnote-313463366
Ref: Library<45>-Footnote-323463423
Ref: Library<45>-Footnote-333463480
Ref: Library<45>-Footnote-343463537
Ref: Library<45>-Footnote-353463593
Ref: Library<45>-Footnote-363463650
Ref: Library<45>-Footnote-373463707
Ref: Library<45>-Footnote-383463763
Ref: Library<45>-Footnote-393463820
Ref: Library<45>-Footnote-403463876
Ref: Library<45>-Footnote-413463933
Ref: Library<45>-Footnote-423463990
Ref: Library<45>-Footnote-433464047
Ref: Library<45>-Footnote-443464103
Ref: Library<45>-Footnote-453464160
Ref: Library<45>-Footnote-463464217
Ref: Library<45>-Footnote-473464273
Ref: Library<45>-Footnote-483464330
Ref: Library<45>-Footnote-493464387
Ref: Library<45>-Footnote-503464444
Ref: Library<45>-Footnote-513464501
Ref: Library<45>-Footnote-523464558
Ref: Library<45>-Footnote-533464615
Ref: Library<45>-Footnote-543464671
Ref: Library<45>-Footnote-553464728
Ref: Library<45>-Footnote-563464784
Ref: Library<45>-Footnote-573464840
Ref: Library<45>-Footnote-583464896
Ref: Library<45>-Footnote-593464953
Ref: Library<45>-Footnote-603465009
Ref: Library<45>-Footnote-613465066
Ref: Library<45>-Footnote-623465123
Ref: Library<45>-Footnote-633465180
Ref: Library<45>-Footnote-643465236
Ref: Library<45>-Footnote-653465292
Ref: Library<45>-Footnote-663465348
Ref: Library<45>-Footnote-673465405
Ref: Library<45>-Footnote-683465462
Ref: Library<45>-Footnote-693465519
Ref: Library<45>-Footnote-703465576
Ref: Library<45>-Footnote-713465633
Ref: Library<45>-Footnote-723465690
Ref: Library<45>-Footnote-733465747
Ref: Library<45>-Footnote-743465804
Ref: Library<45>-Footnote-753465861
Ref: Library<45>-Footnote-763465917
Ref: Library<45>-Footnote-773465974
Ref: Library<45>-Footnote-783466031
Ref: Library<45>-Footnote-793466088
Ref: Library<45>-Footnote-803466145
Ref: Library<45>-Footnote-813466202
Ref: Library<45>-Footnote-823466259
Ref: Library<45>-Footnote-833466316
Ref: Library<45>-Footnote-843466373
Ref: Library<45>-Footnote-853466430
Ref: Library<45>-Footnote-863466487
Ref: Library<45>-Footnote-873466559
Ref: Library<45>-Footnote-883466616
Ref: Library<45>-Footnote-893466673
Ref: Library<45>-Footnote-903466730
Ref: Library<45>-Footnote-913466787
Ref: Library<45>-Footnote-923466844
Ref: Library<45>-Footnote-933466901
Ref: Library<45>-Footnote-943466958
Ref: Library<45>-Footnote-953467014
Ref: Library<45>-Footnote-963467071
Ref: Library<45>-Footnote-973467128
Ref: Library<45>-Footnote-983467184
Ref: Library<45>-Footnote-993467241
Ref: Library<45>-Footnote-1003467298
Ref: Library<45>-Footnote-1013467356
Ref: Library<45>-Footnote-1023467414
Ref: Library<45>-Footnote-1033467471
Ref: Library<45>-Footnote-1043467529
Ref: Library<45>-Footnote-1053467587
Ref: Library<45>-Footnote-1063467645
Ref: Library<45>-Footnote-1073467703
Ref: Library<45>-Footnote-1083467761
Ref: Library<45>-Footnote-1093467819
Ref: Library<45>-Footnote-1103467877
Ref: Library<45>-Footnote-1113467935
Ref: Library<45>-Footnote-1123467993
Ref: Library<45>-Footnote-1133468051
Ref: Library<45>-Footnote-1143468109
Ref: Library<45>-Footnote-1153468167
Ref: Library<45>-Footnote-1163468225
Ref: Library<45>-Footnote-1173468283
Ref: Library<45>-Footnote-1183468341
Ref: Library<45>-Footnote-1193468399
Ref: Library<45>-Footnote-1203468457
Ref: Library<45>-Footnote-1213468515
Ref: Library<45>-Footnote-1223468573
Ref: Library<45>-Footnote-1233468631
Ref: Library<45>-Footnote-1243468689
Ref: Library<45>-Footnote-1253468747
Ref: Library<45>-Footnote-1263468804
Ref: Library<45>-Footnote-1273468862
Ref: Library<45>-Footnote-1283468920
Ref: Library<45>-Footnote-1293468977
Ref: Library<45>-Footnote-1303469035
Ref: Library<45>-Footnote-1313469093
Ref: Library<45>-Footnote-1323469151
Ref: Library<45>-Footnote-1333469209
Ref: Library<45>-Footnote-1343469267
Ref: Library<45>-Footnote-1353469325
Ref: Library<45>-Footnote-1363469383
Ref: Library<45>-Footnote-1373469441
Ref: Library<45>-Footnote-1383469499
Ref: Library<45>-Footnote-1393469543
Ref: Library<45>-Footnote-1403469601
Ref: Library<45>-Footnote-1413469659
Ref: Library<45>-Footnote-1423469717
Ref: Library<45>-Footnote-1433469775
Ref: Library<45>-Footnote-1443469833
Ref: Library<45>-Footnote-1453469891
Ref: Library<45>-Footnote-1463469948
Ref: Library<45>-Footnote-1473470006
Ref: Library<45>-Footnote-1483470064
Ref: Library<45>-Footnote-1493470122
Ref: Library<45>-Footnote-1503470180
Ref: Library<45>-Footnote-1513470237
Ref: Library<45>-Footnote-1523470295
Ref: Library<45>-Footnote-1533470353
Ref: Library<45>-Footnote-1543470411
Ref: Library<45>-Footnote-1553470469
Ref: Library<45>-Footnote-1563470527
Ref: Library<45>-Footnote-1573470585
Ref: Library<45>-Footnote-1583470643
Ref: Library<45>-Footnote-1593470700
Ref: Library<45>-Footnote-1603470757
Ref: Library<45>-Footnote-1613470815
Ref: Library<45>-Footnote-1623470873
Ref: Library<45>-Footnote-1633470931
Ref: Library<45>-Footnote-1643470989
Ref: Library<45>-Footnote-1653471047
Ref: Library<45>-Footnote-1663471105
Ref: Library<45>-Footnote-1673471163
Ref: Library<45>-Footnote-1683471220
Ref: Library<45>-Footnote-1693471278
Ref: Library<45>-Footnote-1703471336
Ref: Library<45>-Footnote-1713471394
Ref: Library<45>-Footnote-1723471452
Ref: Library<45>-Footnote-1733471510
Ref: Library<45>-Footnote-1743471568
Ref: Library<45>-Footnote-1753471626
Ref: Library<45>-Footnote-1763471684
Ref: Library<45>-Footnote-1773471741
Ref: Library<45>-Footnote-1783471799
Ref: Library<45>-Footnote-1793471857
Ref: Library<45>-Footnote-1803471915
Ref: Library<45>-Footnote-1813471973
Ref: Library<45>-Footnote-1823472031
Ref: Library<45>-Footnote-1833472089
Ref: Library<45>-Footnote-1843472147
Ref: Library<45>-Footnote-1853472204
Ref: Library<45>-Footnote-1863472262
Ref: Library<45>-Footnote-1873472320
Ref: Library<45>-Footnote-1883472378
Ref: Library<45>-Footnote-1893472436
Ref: Library<45>-Footnote-1903472494
Ref: Library<45>-Footnote-1913472552
Ref: Library<45>-Footnote-1923472610
Ref: Library<45>-Footnote-1933472668
Ref: Library<45>-Footnote-1943472725
Ref: Library<45>-Footnote-1953472783
Ref: Library<45>-Footnote-1963472841
Ref: Library<45>-Footnote-1973472899
Ref: Library<45>-Footnote-1983472957
Ref: Library<45>-Footnote-1993473015
Ref: Library<45>-Footnote-2003473073
Ref: Library<45>-Footnote-2013473131
Ref: Library<45>-Footnote-2023473189
Ref: Library<45>-Footnote-2033473247
Ref: Library<45>-Footnote-2043473305
Ref: Library<45>-Footnote-2053473363
Ref: Library<45>-Footnote-2063473421
Ref: Library<45>-Footnote-2073473478
Ref: Library<45>-Footnote-2083473536
Ref: Library<45>-Footnote-2093473594
Ref: Library<45>-Footnote-2103473638
Ref: Library<45>-Footnote-2113473682
Ref: Library<45>-Footnote-2123473740
Ref: Library<45>-Footnote-2133473798
Ref: Library<45>-Footnote-2143473855
Ref: Library<45>-Footnote-2153473913
Ref: Library<45>-Footnote-2163473971
Ref: Library<45>-Footnote-2173474015
Ref: Library<45>-Footnote-2183474073
Ref: Library<45>-Footnote-2193474131
Ref: Library<45>-Footnote-2203474189
Ref: Library<45>-Footnote-2213474247
Ref: Library<45>-Footnote-2223474304
Ref: Library<45>-Footnote-2233474362
Ref: Library<45>-Footnote-2243474420
Ref: Library<45>-Footnote-2253474478
Ref: Library<45>-Footnote-2263474536
Ref: Library<45>-Footnote-2273474594
Ref: Library<45>-Footnote-2283474652
Ref: Library<45>-Footnote-2293474710
Ref: Library<45>-Footnote-2303474768
Ref: Library<45>-Footnote-2313474826
Ref: Library<45>-Footnote-2323474884
Ref: Library<45>-Footnote-2333474942
Ref: Library<45>-Footnote-2343475000
Ref: Library<45>-Footnote-2353475058
Ref: Library<45>-Footnote-2363475115
Ref: Library<45>-Footnote-2373475173
Ref: Library<45>-Footnote-2383475231
Ref: Library<45>-Footnote-2393475288
Ref: Library<45>-Footnote-2403475346
Ref: Library<45>-Footnote-2413475404
Ref: Library<45>-Footnote-2423475462
Ref: Library<45>-Footnote-2433475520
Ref: Library<45>-Footnote-2443475577
Ref: Library<45>-Footnote-2453475635
Ref: Library<45>-Footnote-2463475692
Ref: Library<45>-Footnote-2473475749
Ref: Library<45>-Footnote-2483475807
Ref: Library<45>-Footnote-2493475864
Ref: Library<45>-Footnote-2503475922
Ref: Library<45>-Footnote-2513475980
Ref: Library<45>-Footnote-2523476038
Ref: Library<45>-Footnote-2533476096
Ref: Library<45>-Footnote-2543476154
Ref: Library<45>-Footnote-2553476212
Ref: Library<45>-Footnote-2563476270
Ref: Library<45>-Footnote-2573476328
Ref: Library<45>-Footnote-2583476386
Ref: Library<45>-Footnote-2593476443
Ref: Library<45>-Footnote-2603476501
Ref: Library<45>-Footnote-2613476559
Ref: Library<45>-Footnote-2623476617
Ref: Library<45>-Footnote-2633476675
Ref: Library<45>-Footnote-2643476733
Ref: Library<45>-Footnote-2653476791
Ref: Library<45>-Footnote-2663476849
Ref: Library<45>-Footnote-2673476907
Ref: Library<45>-Footnote-2683476965
Ref: Library<45>-Footnote-2693477023
Ref: Library<45>-Footnote-2703477081
Ref: Library<45>-Footnote-2713477139
Ref: Library<45>-Footnote-2723477197
Ref: Library<45>-Footnote-2733477255
Ref: Library<45>-Footnote-2743477313
Ref: Library<45>-Footnote-2753477370
Ref: Library<45>-Footnote-2763477427
Ref: Library<45>-Footnote-2773477484
Ref: Library<45>-Footnote-2783477542
Ref: Library<45>-Footnote-2793477600
Ref: Library<45>-Footnote-2803477658
Ref: Library<45>-Footnote-2813477716
Ref: Library<45>-Footnote-2823477774
Ref: Library<45>-Footnote-2833477832
Ref: Library<45>-Footnote-2843477890
Ref: Library<45>-Footnote-2853477948
Ref: Library<45>-Footnote-2863478006
Ref: Library<45>-Footnote-2873478064
Ref: Library<45>-Footnote-2883478122
Ref: Library<45>-Footnote-2893478180
Ref: Library<45>-Footnote-2903478238
Ref: Library<45>-Footnote-2913478295
Ref: Library<45>-Footnote-2923478353
Ref: Library<45>-Footnote-2933478410
Ref: Library<45>-Footnote-2943478468
Ref: Library<45>-Footnote-2953478526
Ref: Library<45>-Footnote-2963478584
Ref: Library<45>-Footnote-2973478642
Ref: Library<45>-Footnote-2983478700
Ref: Library<45>-Footnote-2993478758
Ref: Library<45>-Footnote-3003478816
Ref: Library<45>-Footnote-3013478874
Ref: Library<45>-Footnote-3023478932
Ref: Library<45>-Footnote-3033478990
Ref: Library<45>-Footnote-3043479074
Ref: Library<45>-Footnote-3053479132
Ref: Library<45>-Footnote-3063479190
Ref: Library<45>-Footnote-3073479248
Ref: Library<45>-Footnote-3083479306
Ref: Library<45>-Footnote-3093479364
Ref: Library<45>-Footnote-3103479422
Ref: Library<45>-Footnote-3113479480
Ref: Library<45>-Footnote-3123479538
Ref: Library<45>-Footnote-3133479596
Ref: Library<45>-Footnote-3143479654
Ref: Library<45>-Footnote-3153479712
Ref: Library<45>-Footnote-3163479769
Ref: Library<45>-Footnote-3173479827
Ref: Library<45>-Footnote-3183479884
Ref: Library<45>-Footnote-3193479942
Ref: Library<45>-Footnote-3203480009
Ref: Library<45>-Footnote-3213480076
Ref: Library<45>-Footnote-3223480143
Ref: Library<45>-Footnote-3233480210
Ref: Library<45>-Footnote-3243480267
Node: IDLE<7>3480334
Ref: whatsnew/changelog id1823480445
Ref: 19493480445
Ref: IDLE<7>-Footnote-13481299
Ref: IDLE<7>-Footnote-23481355
Ref: IDLE<7>-Footnote-33481411
Ref: IDLE<7>-Footnote-43481467
Ref: IDLE<7>-Footnote-53481522
Ref: IDLE<7>-Footnote-63481578
Node: Documentation<13>3481634
Ref: whatsnew/changelog id1833481755
Ref: 194a3481755
Ref: Documentation<13>-Footnote-13484272
Ref: Documentation<13>-Footnote-23484328
Ref: Documentation<13>-Footnote-33484384
Ref: Documentation<13>-Footnote-43484440
Ref: Documentation<13>-Footnote-53484496
Ref: Documentation<13>-Footnote-63484552
Ref: Documentation<13>-Footnote-73484608
Ref: Documentation<13>-Footnote-83484663
Ref: Documentation<13>-Footnote-93484719
Ref: Documentation<13>-Footnote-103484775
Ref: Documentation<13>-Footnote-113484832
Ref: Documentation<13>-Footnote-123484889
Ref: Documentation<13>-Footnote-133484946
Node: Core and Builtins<40>3485012
Ref: whatsnew/changelog id1843485137
Ref: 19523485137
Ref: Core and Builtins<40>-Footnote-13485874
Ref: Core and Builtins<40>-Footnote-23485930
Ref: Core and Builtins<40>-Footnote-33485986
Ref: Core and Builtins<40>-Footnote-43486042
Node: Library<46>3486098
Ref: whatsnew/changelog id1853486227
Ref: 19543486227
Ref: Library<46>-Footnote-13486453
Node: Core and Builtins<41>3486509
Ref: whatsnew/changelog id1863486628
Ref: 19553486628
Ref: Core and Builtins<41>-Footnote-13490781
Ref: Core and Builtins<41>-Footnote-23490837
Ref: Core and Builtins<41>-Footnote-33490893
Ref: Core and Builtins<41>-Footnote-43490949
Ref: Core and Builtins<41>-Footnote-53491005
Ref: Core and Builtins<41>-Footnote-63491061
Ref: Core and Builtins<41>-Footnote-73491117
Ref: Core and Builtins<41>-Footnote-83491173
Ref: Core and Builtins<41>-Footnote-93491229
Ref: Core and Builtins<41>-Footnote-103491285
Ref: Core and Builtins<41>-Footnote-113491342
Ref: Core and Builtins<41>-Footnote-123491399
Ref: Core and Builtins<41>-Footnote-133491456
Ref: Core and Builtins<41>-Footnote-143491512
Ref: Core and Builtins<41>-Footnote-153491569
Ref: Core and Builtins<41>-Footnote-163491626
Ref: Core and Builtins<41>-Footnote-173491683
Ref: Core and Builtins<41>-Footnote-183491740
Ref: Core and Builtins<41>-Footnote-193491797
Ref: Core and Builtins<41>-Footnote-203491854
Ref: Core and Builtins<41>-Footnote-213491911
Ref: Core and Builtins<41>-Footnote-223491967
Ref: Core and Builtins<41>-Footnote-233492024
Ref: Core and Builtins<41>-Footnote-243492081
Node: Library<47>3492138
Ref: whatsnew/changelog id1873492267
Ref: 19573492267
Ref: Library<47>-Footnote-13492499
Node: Core and Builtins<42>3492555
Ref: whatsnew/changelog id1883492674
Ref: 19593492674
Ref: Core and Builtins<42>-Footnote-13500502
Ref: Core and Builtins<42>-Footnote-23500558
Ref: Core and Builtins<42>-Footnote-33500614
Ref: Core and Builtins<42>-Footnote-43500670
Ref: Core and Builtins<42>-Footnote-53500726
Ref: Core and Builtins<42>-Footnote-63500782
Ref: Core and Builtins<42>-Footnote-73500838
Ref: Core and Builtins<42>-Footnote-83500894
Ref: Core and Builtins<42>-Footnote-93500950
Ref: Core and Builtins<42>-Footnote-103501006
Ref: Core and Builtins<42>-Footnote-113501063
Ref: Core and Builtins<42>-Footnote-123501120
Ref: Core and Builtins<42>-Footnote-133501177
Ref: Core and Builtins<42>-Footnote-143501234
Ref: Core and Builtins<42>-Footnote-153501291
Ref: Core and Builtins<42>-Footnote-163501348
Ref: Core and Builtins<42>-Footnote-173501405
Ref: Core and Builtins<42>-Footnote-183501462
Ref: Core and Builtins<42>-Footnote-193501519
Ref: Core and Builtins<42>-Footnote-203501576
Ref: Core and Builtins<42>-Footnote-213501633
Ref: Core and Builtins<42>-Footnote-223501690
Ref: Core and Builtins<42>-Footnote-233501747
Ref: Core and Builtins<42>-Footnote-243501804
Ref: Core and Builtins<42>-Footnote-253501861
Ref: Core and Builtins<42>-Footnote-263501918
Ref: Core and Builtins<42>-Footnote-273501975
Ref: Core and Builtins<42>-Footnote-283502032
Ref: Core and Builtins<42>-Footnote-293502089
Ref: Core and Builtins<42>-Footnote-303502146
Ref: Core and Builtins<42>-Footnote-313502203
Ref: Core and Builtins<42>-Footnote-323502260
Ref: Core and Builtins<42>-Footnote-333502317
Ref: Core and Builtins<42>-Footnote-343502374
Ref: Core and Builtins<42>-Footnote-353502431
Ref: Core and Builtins<42>-Footnote-363502488
Ref: Core and Builtins<42>-Footnote-373502545
Ref: Core and Builtins<42>-Footnote-383502602
Ref: Core and Builtins<42>-Footnote-393502659
Ref: Core and Builtins<42>-Footnote-403502716
Ref: Core and Builtins<42>-Footnote-413502773
Ref: Core and Builtins<42>-Footnote-423502830
Ref: Core and Builtins<42>-Footnote-433502887
Ref: Core and Builtins<42>-Footnote-443502944
Ref: Core and Builtins<42>-Footnote-453503001
Ref: Core and Builtins<42>-Footnote-463503058
Node: Library<48>3503114
Ref: whatsnew/changelog id1893503243
Ref: 195e3503243
Ref: Library<48>-Footnote-13503440
Node: Core and Builtins<43>3503496
Ref: whatsnew/changelog id1903503615
Ref: 195f3503615
Ref: Core and Builtins<43>-Footnote-13506517
Ref: Core and Builtins<43>-Footnote-23506573
Ref: Core and Builtins<43>-Footnote-33506629
Ref: Core and Builtins<43>-Footnote-43506685
Ref: Core and Builtins<43>-Footnote-53506741
Ref: Core and Builtins<43>-Footnote-63506797
Ref: Core and Builtins<43>-Footnote-73506853
Ref: Core and Builtins<43>-Footnote-83506909
Ref: Core and Builtins<43>-Footnote-93506965
Ref: Core and Builtins<43>-Footnote-103507021
Ref: Core and Builtins<43>-Footnote-113507078
Ref: Core and Builtins<43>-Footnote-123507135
Ref: Core and Builtins<43>-Footnote-133507192
Ref: Core and Builtins<43>-Footnote-143507249
Ref: Core and Builtins<43>-Footnote-153507306
Ref: Core and Builtins<43>-Footnote-163507363
Ref: Core and Builtins<43>-Footnote-173507420
Ref: Core and Builtins<43>-Footnote-183507477
Node: Library<49>3507534
Ref: whatsnew/changelog id1913507663
Ref: 19633507663
Ref: Library<49>-Footnote-13507920
Node: Core and Builtins<44>3507976
Ref: whatsnew/changelog id1923508095
Ref: 19643508095
Ref: Core and Builtins<44>-Footnote-13510879
Ref: Core and Builtins<44>-Footnote-23510935
Ref: Core and Builtins<44>-Footnote-33510991
Ref: Core and Builtins<44>-Footnote-43511047
Ref: Core and Builtins<44>-Footnote-53511103
Ref: Core and Builtins<44>-Footnote-63511159
Ref: Core and Builtins<44>-Footnote-73511215
Ref: Core and Builtins<44>-Footnote-83511270
Ref: Core and Builtins<44>-Footnote-93511326
Ref: Core and Builtins<44>-Footnote-103511382
Ref: Core and Builtins<44>-Footnote-113511439
Ref: Core and Builtins<44>-Footnote-123511496
Ref: Core and Builtins<44>-Footnote-133511553
Ref: Core and Builtins<44>-Footnote-143511610
Ref: Core and Builtins<44>-Footnote-153511667
Node: Library<50>3511724
Ref: whatsnew/changelog id1933511853
Ref: 19653511853
Ref: Library<50>-Footnote-13512104
Node: Core and Builtins<45>3512160
Ref: whatsnew/changelog id1943512279
Ref: 19663512279
Ref: Core and Builtins<45>-Footnote-13512803
Ref: Core and Builtins<45>-Footnote-23512859
Node: Library<51>3512915
Ref: whatsnew/changelog id1953513044
Ref: 19673513044
Ref: Library<51>-Footnote-13513319
Node: Core and Builtins<46>3513375
Ref: whatsnew/changelog id1963513494
Ref: 19683513494
Ref: Core and Builtins<46>-Footnote-13520744
Ref: Core and Builtins<46>-Footnote-23520800
Ref: Core and Builtins<46>-Footnote-33520856
Ref: Core and Builtins<46>-Footnote-43520912
Ref: Core and Builtins<46>-Footnote-53520967
Ref: Core and Builtins<46>-Footnote-63521023
Ref: Core and Builtins<46>-Footnote-73521079
Ref: Core and Builtins<46>-Footnote-83521135
Ref: Core and Builtins<46>-Footnote-93521191
Ref: Core and Builtins<46>-Footnote-103521247
Ref: Core and Builtins<46>-Footnote-113521303
Ref: Core and Builtins<46>-Footnote-123521360
Ref: Core and Builtins<46>-Footnote-133521417
Ref: Core and Builtins<46>-Footnote-143521474
Ref: Core and Builtins<46>-Footnote-153521531
Ref: Core and Builtins<46>-Footnote-163521588
Ref: Core and Builtins<46>-Footnote-173521645
Ref: Core and Builtins<46>-Footnote-183521702
Ref: Core and Builtins<46>-Footnote-193521745
Ref: Core and Builtins<46>-Footnote-203521802
Ref: Core and Builtins<46>-Footnote-213521859
Ref: Core and Builtins<46>-Footnote-223521916
Ref: Core and Builtins<46>-Footnote-233521973
Ref: Core and Builtins<46>-Footnote-243522030
Ref: Core and Builtins<46>-Footnote-253522087
Ref: Core and Builtins<46>-Footnote-263522144
Ref: Core and Builtins<46>-Footnote-273522201
Ref: Core and Builtins<46>-Footnote-283522258
Ref: Core and Builtins<46>-Footnote-293522315
Ref: Core and Builtins<46>-Footnote-303522372
Ref: Core and Builtins<46>-Footnote-313522429
Ref: Core and Builtins<46>-Footnote-323522486
Ref: Core and Builtins<46>-Footnote-333522543
Ref: Core and Builtins<46>-Footnote-343522600
Ref: Core and Builtins<46>-Footnote-353522643
Ref: Core and Builtins<46>-Footnote-363522700
Ref: Core and Builtins<46>-Footnote-373522757
Ref: Core and Builtins<46>-Footnote-383522814
Ref: Core and Builtins<46>-Footnote-393522871
Ref: Core and Builtins<46>-Footnote-403522928
Ref: Core and Builtins<46>-Footnote-413522971
Ref: Core and Builtins<46>-Footnote-423523028
Ref: Core and Builtins<46>-Footnote-433523085
Ref: Core and Builtins<46>-Footnote-443523142
Ref: Core and Builtins<46>-Footnote-453523199
Ref: Core and Builtins<46>-Footnote-463523256
Ref: Core and Builtins<46>-Footnote-473523313
Ref: Core and Builtins<46>-Footnote-483523370
Ref: Core and Builtins<46>-Footnote-493523427
Ref: Core and Builtins<46>-Footnote-503523484
Node: Library<52>3523527
Ref: whatsnew/changelog id1973523656
Ref: 196c3523656
Ref: Library<52>-Footnote-13523884
Node: Core and Builtins<47>3523940
Ref: whatsnew/changelog id1983524057
Ref: 196f3524057
Ref: Core and Builtins<47>-Footnote-13525102
Ref: Core and Builtins<47>-Footnote-23525158
Ref: Core and Builtins<47>-Footnote-33525214
Ref: Core and Builtins<47>-Footnote-43525270
Ref: Core and Builtins<47>-Footnote-53525326
Ref: Core and Builtins<47>-Footnote-63525382
Ref: Core and Builtins<47>-Footnote-73525437
Ref: Core and Builtins<47>-Footnote-83525492
Node: C API<15>3525557
Ref: whatsnew/changelog id1993525672
Ref: 19703525672
Ref: C API<15>-Footnote-13537488
Ref: C API<15>-Footnote-23537544
Ref: C API<15>-Footnote-33537600
Ref: C API<15>-Footnote-43537656
Ref: C API<15>-Footnote-53537698
Ref: C API<15>-Footnote-63537740
Ref: C API<15>-Footnote-73537796
Ref: C API<15>-Footnote-83537852
Ref: C API<15>-Footnote-93537894
Ref: C API<15>-Footnote-103537936
Ref: C API<15>-Footnote-113537993
Ref: C API<15>-Footnote-123538050
Ref: C API<15>-Footnote-133538107
Ref: C API<15>-Footnote-143538164
Ref: C API<15>-Footnote-153538207
Ref: C API<15>-Footnote-163538264
Ref: C API<15>-Footnote-173538321
Ref: C API<15>-Footnote-183538378
Ref: C API<15>-Footnote-193538435
Ref: C API<15>-Footnote-203538492
Ref: C API<15>-Footnote-213538549
Ref: C API<15>-Footnote-223538606
Ref: C API<15>-Footnote-233538663
Ref: C API<15>-Footnote-243538720
Ref: C API<15>-Footnote-253538776
Ref: C API<15>-Footnote-263538833
Ref: C API<15>-Footnote-273538890
Ref: C API<15>-Footnote-283538947
Ref: C API<15>-Footnote-293539004
Ref: C API<15>-Footnote-303539061
Ref: C API<15>-Footnote-313539118
Ref: C API<15>-Footnote-323539175
Ref: C API<15>-Footnote-333539232
Ref: C API<15>-Footnote-343539288
Ref: C API<15>-Footnote-353539345
Ref: C API<15>-Footnote-363539402
Ref: C API<15>-Footnote-373539459
Ref: C API<15>-Footnote-383539516
Ref: C API<15>-Footnote-393539573
Ref: C API<15>-Footnote-403539630
Ref: C API<15>-Footnote-413539687
Ref: C API<15>-Footnote-423539744
Ref: C API<15>-Footnote-433539801
Ref: C API<15>-Footnote-443539858
Ref: C API<15>-Footnote-453539915
Ref: C API<15>-Footnote-463539972
Ref: C API<15>-Footnote-473540029
Ref: C API<15>-Footnote-483540086
Ref: C API<15>-Footnote-493540143
Ref: C API<15>-Footnote-503540200
Ref: C API<15>-Footnote-513540257
Ref: C API<15>-Footnote-523540313
Ref: C API<15>-Footnote-533540369
Node: Build<15>3540435
Ref: whatsnew/changelog id2003540520
Ref: 197e3540520
Ref: Build<15>-Footnote-13545088
Ref: Build<15>-Footnote-23545144
Ref: Build<15>-Footnote-33545200
Ref: Build<15>-Footnote-43545256
Ref: Build<15>-Footnote-53545312
Ref: Build<15>-Footnote-63545368
Ref: Build<15>-Footnote-73545424
Ref: Build<15>-Footnote-83545480
Ref: Build<15>-Footnote-93545536
Ref: Build<15>-Footnote-103545592
Ref: Build<15>-Footnote-113545649
Ref: Build<15>-Footnote-123545706
Ref: Build<15>-Footnote-133545763
Ref: Build<15>-Footnote-143545820
Ref: Build<15>-Footnote-153545877
Ref: Build<15>-Footnote-163545934
Ref: Build<15>-Footnote-173545991
Ref: Build<15>-Footnote-183546048
Ref: Build<15>-Footnote-193546105
Ref: Build<15>-Footnote-203546162
Ref: Build<15>-Footnote-213546219
Ref: Build<15>-Footnote-223546276
Ref: Build<15>-Footnote-233546333
Ref: Build<15>-Footnote-243546390
Ref: Build<15>-Footnote-253546447
Ref: Build<15>-Footnote-263546504
Ref: Build<15>-Footnote-273546561
Ref: Build<15>-Footnote-283546618
Ref: Build<15>-Footnote-293546675
Ref: Build<15>-Footnote-303546732
Ref: Build<15>-Footnote-313546789
Ref: Build<15>-Footnote-323546846
Node: Python 3 13 0 beta 13546903
Ref: whatsnew/changelog python-3-13-0-beta-13547029
Ref: 19803547029
Node: Security<17>3547424
Ref: whatsnew/changelog id2013547523
Ref: 19813547523
Ref: Security<17>-Footnote-13547918
Ref: Security<17>-Footnote-23547974
Node: Core and Builtins<48>3548030
Ref: whatsnew/changelog id2023548149
Ref: 19823548149
Ref: Core and Builtins<48>-Footnote-13549297
Ref: Core and Builtins<48>-Footnote-23549353
Ref: Core and Builtins<48>-Footnote-33549409
Node: Library<53>3549465
Ref: whatsnew/changelog id2033549593
Ref: 19833549593
Ref: Library<53>-Footnote-13549924
Node: Core and Builtins<49>3549979
Ref: whatsnew/changelog id2043550097
Ref: 19843550097
Ref: Core and Builtins<49>-Footnote-13558179
Ref: Core and Builtins<49>-Footnote-23558235
Ref: Core and Builtins<49>-Footnote-33558291
Ref: Core and Builtins<49>-Footnote-43558347
Ref: Core and Builtins<49>-Footnote-53558403
Ref: Core and Builtins<49>-Footnote-63558459
Ref: Core and Builtins<49>-Footnote-73558515
Ref: Core and Builtins<49>-Footnote-83558571
Ref: Core and Builtins<49>-Footnote-93558627
Ref: Core and Builtins<49>-Footnote-103558683
Ref: Core and Builtins<49>-Footnote-113558740
Ref: Core and Builtins<49>-Footnote-123558796
Ref: Core and Builtins<49>-Footnote-133558853
Ref: Core and Builtins<49>-Footnote-143558910
Ref: Core and Builtins<49>-Footnote-153558967
Ref: Core and Builtins<49>-Footnote-163559024
Ref: Core and Builtins<49>-Footnote-173559081
Ref: Core and Builtins<49>-Footnote-183559138
Ref: Core and Builtins<49>-Footnote-193559195
Ref: Core and Builtins<49>-Footnote-203559252
Ref: Core and Builtins<49>-Footnote-213559309
Ref: Core and Builtins<49>-Footnote-223559366
Ref: Core and Builtins<49>-Footnote-233559423
Ref: Core and Builtins<49>-Footnote-243559480
Ref: Core and Builtins<49>-Footnote-253559537
Ref: Core and Builtins<49>-Footnote-263559594
Ref: Core and Builtins<49>-Footnote-273559651
Ref: Core and Builtins<49>-Footnote-283559708
Ref: Core and Builtins<49>-Footnote-293559765
Ref: Core and Builtins<49>-Footnote-303559822
Ref: Core and Builtins<49>-Footnote-313559879
Ref: Core and Builtins<49>-Footnote-323559936
Ref: Core and Builtins<49>-Footnote-333559993
Ref: Core and Builtins<49>-Footnote-343560036
Ref: Core and Builtins<49>-Footnote-353560093
Ref: Core and Builtins<49>-Footnote-363560150
Ref: Core and Builtins<49>-Footnote-373560207
Ref: Core and Builtins<49>-Footnote-383560264
Ref: Core and Builtins<49>-Footnote-393560321
Ref: Core and Builtins<49>-Footnote-403560364
Ref: Core and Builtins<49>-Footnote-413560420
Ref: Core and Builtins<49>-Footnote-423560477
Ref: Core and Builtins<49>-Footnote-433560533
Ref: Core and Builtins<49>-Footnote-443560589
Node: Library<54>3560646
Ref: whatsnew/changelog id2053560770
Ref: 19873560770
Ref: Library<54>-Footnote-13577053
Ref: Library<54>-Footnote-23577109
Ref: Library<54>-Footnote-33577165
Ref: Library<54>-Footnote-43577221
Ref: Library<54>-Footnote-53577277
Ref: Library<54>-Footnote-63577333
Ref: Library<54>-Footnote-73577389
Ref: Library<54>-Footnote-83577445
Ref: Library<54>-Footnote-93577501
Ref: Library<54>-Footnote-103577557
Ref: Library<54>-Footnote-113577614
Ref: Library<54>-Footnote-123577671
Ref: Library<54>-Footnote-133577728
Ref: Library<54>-Footnote-143577785
Ref: Library<54>-Footnote-153577828
Ref: Library<54>-Footnote-163577885
Ref: Library<54>-Footnote-173577942
Ref: Library<54>-Footnote-183577999
Ref: Library<54>-Footnote-193578056
Ref: Library<54>-Footnote-203578113
Ref: Library<54>-Footnote-213578170
Ref: Library<54>-Footnote-223578227
Ref: Library<54>-Footnote-233578284
Ref: Library<54>-Footnote-243578341
Ref: Library<54>-Footnote-253578397
Ref: Library<54>-Footnote-263578454
Ref: Library<54>-Footnote-273578511
Ref: Library<54>-Footnote-283578568
Ref: Library<54>-Footnote-293578625
Ref: Library<54>-Footnote-303578682
Ref: Library<54>-Footnote-313578739
Ref: Library<54>-Footnote-323578782
Ref: Library<54>-Footnote-333578839
Ref: Library<54>-Footnote-343578896
Ref: Library<54>-Footnote-353578953
Ref: Library<54>-Footnote-363579009
Ref: Library<54>-Footnote-373579069
Ref: Library<54>-Footnote-383579125
Ref: Library<54>-Footnote-393579182
Ref: Library<54>-Footnote-403579239
Ref: Library<54>-Footnote-413579296
Ref: Library<54>-Footnote-423579352
Ref: Library<54>-Footnote-433579408
Ref: Library<54>-Footnote-443579451
Ref: Library<54>-Footnote-453579508
Ref: Library<54>-Footnote-463579565
Ref: Library<54>-Footnote-473579622
Ref: Library<54>-Footnote-483579679
Ref: Library<54>-Footnote-493579736
Ref: Library<54>-Footnote-503579793
Ref: Library<54>-Footnote-513579850
Ref: Library<54>-Footnote-523579907
Ref: Library<54>-Footnote-533579964
Ref: Library<54>-Footnote-543580021
Ref: Library<54>-Footnote-553580078
Ref: Library<54>-Footnote-563580135
Ref: Library<54>-Footnote-573580192
Ref: Library<54>-Footnote-583580249
Ref: Library<54>-Footnote-593580306
Ref: Library<54>-Footnote-603580363
Ref: Library<54>-Footnote-613580420
Ref: Library<54>-Footnote-623580477
Ref: Library<54>-Footnote-633580520
Ref: Library<54>-Footnote-643580577
Ref: Library<54>-Footnote-653580634
Ref: Library<54>-Footnote-663580691
Ref: Library<54>-Footnote-673580748
Ref: Library<54>-Footnote-683580791
Ref: Library<54>-Footnote-693580847
Ref: Library<54>-Footnote-703580903
Ref: Library<54>-Footnote-713580960
Ref: Library<54>-Footnote-723581017
Ref: Library<54>-Footnote-733581074
Ref: Library<54>-Footnote-743581130
Ref: Library<54>-Footnote-753581186
Ref: Library<54>-Footnote-763581243
Ref: Library<54>-Footnote-773581300
Ref: Library<54>-Footnote-783581357
Ref: Library<54>-Footnote-793581414
Ref: Library<54>-Footnote-803581470
Ref: Library<54>-Footnote-813581527
Ref: Library<54>-Footnote-823581584
Ref: Library<54>-Footnote-833581640
Ref: Library<54>-Footnote-843581697
Ref: Library<54>-Footnote-853581754
Ref: Library<54>-Footnote-863581810
Ref: Library<54>-Footnote-873581866
Ref: Library<54>-Footnote-883581932
Ref: Library<54>-Footnote-893581998
Ref: Library<54>-Footnote-903582064
Ref: Library<54>-Footnote-913582130
Node: Documentation<14>3582196
Ref: whatsnew/changelog id2063582308
Ref: 19953582308
Ref: Documentation<14>-Footnote-13582490
Node: Build<16>3582546
Ref: whatsnew/changelog id2073582658
Ref: 19963582658
Ref: Build<16>-Footnote-13583607
Ref: Build<16>-Footnote-23583663
Ref: Build<16>-Footnote-33583719
Ref: Build<16>-Footnote-43583775
Ref: Build<16>-Footnote-53583831
Ref: Build<16>-Footnote-63583887
Node: Windows<14>3583943
Ref: whatsnew/changelog id2083584046
Ref: 19973584046
Ref: Windows<14>-Footnote-13585085
Ref: Windows<14>-Footnote-23585141
Ref: Windows<14>-Footnote-33585197
Ref: Windows<14>-Footnote-43585253
Ref: Windows<14>-Footnote-53585309
Ref: Windows<14>-Footnote-63585365
Ref: Windows<14>-Footnote-73585420
Node: macOS<8>3585476
Ref: whatsnew/changelog id2093585577
Ref: 19983585577
Ref: macOS<8>-Footnote-13586021
Ref: macOS<8>-Footnote-23586077
Ref: macOS<8>-Footnote-33586133
Ref: macOS<8>-Footnote-43586189
Node: IDLE<8>3586244
Ref: whatsnew/changelog id2103586343
Ref: 19993586343
Ref: IDLE<8>-Footnote-13586484
Node: C API<16>3586549
Ref: whatsnew/changelog id2113586631
Ref: 199a3586631
Ref: C API<16>-Footnote-13587922
Ref: C API<16>-Footnote-23587978
Ref: C API<16>-Footnote-33588034
Ref: C API<16>-Footnote-43588090
Ref: C API<16>-Footnote-53588146
Ref: C API<16>-Footnote-63588202
Ref: C API<16>-Footnote-73588257
Node: Python 3 13 0 alpha 63588313
Ref: whatsnew/changelog python-3-13-0-alpha-63588439
Ref: 19a23588439
Node: Core and Builtins<50>3588794
Ref: whatsnew/changelog id2123588893
Ref: 19a33588893
Ref: Core and Builtins<50>-Footnote-13593560
Ref: Core and Builtins<50>-Footnote-23593616
Ref: Core and Builtins<50>-Footnote-33593672
Ref: Core and Builtins<50>-Footnote-43593728
Ref: Core and Builtins<50>-Footnote-53593784
Ref: Core and Builtins<50>-Footnote-63593840
Ref: Core and Builtins<50>-Footnote-73593896
Ref: Core and Builtins<50>-Footnote-83593952
Ref: Core and Builtins<50>-Footnote-93594007
Ref: Core and Builtins<50>-Footnote-103594054
Ref: Core and Builtins<50>-Footnote-113594111
Ref: Core and Builtins<50>-Footnote-123594168
Ref: Core and Builtins<50>-Footnote-133594225
Ref: Core and Builtins<50>-Footnote-143594282
Ref: Core and Builtins<50>-Footnote-153594339
Ref: Core and Builtins<50>-Footnote-163594396
Ref: Core and Builtins<50>-Footnote-173594453
Ref: Core and Builtins<50>-Footnote-183594510
Ref: Core and Builtins<50>-Footnote-193594567
Node: Library<55>3594624
Ref: whatsnew/changelog id2133594753
Ref: 19a63594753
Ref: Library<55>-Footnote-13595099
Ref: Library<55>-Footnote-23595155
Node: Core and Builtins<51>3595210
Ref: whatsnew/changelog id2143595329
Ref: 19a73595329
Ref: Core and Builtins<51>-Footnote-13595562
Node: Library<56>3595627
Ref: whatsnew/changelog id2153595752
Ref: 19a83595752
Ref: Library<56>-Footnote-13606542
Ref: Library<56>-Footnote-23606598
Ref: Library<56>-Footnote-33606654
Ref: Library<56>-Footnote-43606710
Ref: Library<56>-Footnote-53606766
Ref: Library<56>-Footnote-63606822
Ref: Library<56>-Footnote-73606878
Ref: Library<56>-Footnote-83606934
Ref: Library<56>-Footnote-93606990
Ref: Library<56>-Footnote-103607046
Ref: Library<56>-Footnote-113607103
Ref: Library<56>-Footnote-123607159
Ref: Library<56>-Footnote-133607215
Ref: Library<56>-Footnote-143607272
Ref: Library<56>-Footnote-153607329
Ref: Library<56>-Footnote-163607385
Ref: Library<56>-Footnote-173607442
Ref: Library<56>-Footnote-183607499
Ref: Library<56>-Footnote-193607556
Ref: Library<56>-Footnote-203607613
Ref: Library<56>-Footnote-213607670
Ref: Library<56>-Footnote-223607727
Ref: Library<56>-Footnote-233607784
Ref: Library<56>-Footnote-243607841
Ref: Library<56>-Footnote-253607898
Ref: Library<56>-Footnote-263607955
Ref: Library<56>-Footnote-273608011
Ref: Library<56>-Footnote-283608068
Ref: Library<56>-Footnote-293608125
Ref: Library<56>-Footnote-303608181
Ref: Library<56>-Footnote-313608238
Ref: Library<56>-Footnote-323608295
Ref: Library<56>-Footnote-333608351
Ref: Library<56>-Footnote-343608408
Ref: Library<56>-Footnote-353608476
Ref: Library<56>-Footnote-363608532
Ref: Library<56>-Footnote-373608589
Ref: Library<56>-Footnote-383608646
Ref: Library<56>-Footnote-393608703
Ref: Library<56>-Footnote-403608760
Ref: Library<56>-Footnote-413608816
Ref: Library<56>-Footnote-423608872
Ref: Library<56>-Footnote-433608928
Ref: Library<56>-Footnote-443608985
Ref: Library<56>-Footnote-453609042
Ref: Library<56>-Footnote-463609099
Ref: Library<56>-Footnote-473609156
Ref: Library<56>-Footnote-483609212
Ref: Library<56>-Footnote-493609268
Ref: Library<56>-Footnote-503609325
Ref: Library<56>-Footnote-513609382
Ref: Library<56>-Footnote-523609439
Ref: Library<56>-Footnote-533609496
Ref: Library<56>-Footnote-543609553
Ref: Library<56>-Footnote-553609609
Ref: Library<56>-Footnote-563609666
Ref: Library<56>-Footnote-573609723
Ref: Library<56>-Footnote-583609780
Ref: Library<56>-Footnote-593609836
Ref: Library<56>-Footnote-603609892
Ref: Library<56>-Footnote-613609958
Ref: Library<56>-Footnote-623610024
Ref: Library<56>-Footnote-633610090
Ref: Library<56>-Footnote-643610146
Node: Documentation<15>3610212
Ref: whatsnew/changelog id2163610325
Ref: 19b03610325
Ref: Documentation<15>-Footnote-13610738
Ref: Documentation<15>-Footnote-23610794
Ref: Documentation<15>-Footnote-33610850
Node: Tests<14>3610905
Ref: whatsnew/changelog id2173611016
Ref: 19b13611016
Ref: Tests<14>-Footnote-13612124
Ref: Tests<14>-Footnote-23612179
Ref: Tests<14>-Footnote-33612235
Ref: Tests<14>-Footnote-43612291
Ref: Tests<14>-Footnote-53612347
Ref: Tests<14>-Footnote-63612403
Ref: Tests<14>-Footnote-73612459
Node: Build<17>3612515
Ref: whatsnew/changelog id2183612620
Ref: 19b23612620
Ref: Build<17>-Footnote-13612898
Ref: Build<17>-Footnote-23612954
Ref: Build<17>-Footnote-33613010
Node: Windows<15>3613065
Ref: whatsnew/changelog id2193613170
Ref: 19b33613170
Ref: Windows<15>-Footnote-13614630
Ref: Windows<15>-Footnote-23614686
Ref: Windows<15>-Footnote-33614742
Ref: Windows<15>-Footnote-43614797
Ref: Windows<15>-Footnote-53614853
Ref: Windows<15>-Footnote-63614908
Node: C API<17>3614964
Ref: whatsnew/changelog id2203615051
Ref: 19b53615051
Ref: C API<17>-Footnote-13618319
Ref: C API<17>-Footnote-23618375
Ref: C API<17>-Footnote-33618417
Ref: C API<17>-Footnote-43618472
Ref: C API<17>-Footnote-53618528
Ref: C API<17>-Footnote-63618584
Ref: C API<17>-Footnote-73618640
Ref: C API<17>-Footnote-83618696
Ref: C API<17>-Footnote-93618752
Ref: C API<17>-Footnote-103618808
Ref: C API<17>-Footnote-113618865
Ref: C API<17>-Footnote-123618922
Ref: C API<17>-Footnote-133618979
Ref: C API<17>-Footnote-143619036
Ref: C API<17>-Footnote-153619079
Ref: C API<17>-Footnote-163619136
Ref: C API<17>-Footnote-173619193
Ref: C API<17>-Footnote-183619249
Ref: C API<17>-Footnote-193619306
Node: Python 3 13 0 alpha 53619363
Ref: whatsnew/changelog python-3-13-0-alpha-53619490
Ref: 19b83619490
Node: Security<18>3620007
Ref: whatsnew/changelog id2213620107
Ref: 19b93620107
Ref: Security<18>-Footnote-13620922
Ref: Security<18>-Footnote-23620978
Ref: Security<18>-Footnote-33621034
Node: Core and Builtins<52>3621090
Ref: whatsnew/changelog id2223621210
Ref: 19ba3621210
Ref: Core and Builtins<52>-Footnote-13622590
Ref: Core and Builtins<52>-Footnote-23622646
Ref: Core and Builtins<52>-Footnote-33622702
Ref: Core and Builtins<52>-Footnote-43622744
Ref: Core and Builtins<52>-Footnote-53622800
Ref: Core and Builtins<52>-Footnote-63622856
Ref: Core and Builtins<52>-Footnote-73622912
Ref: Core and Builtins<52>-Footnote-83622968
Ref: Core and Builtins<52>-Footnote-93623024
Ref: Core and Builtins<52>-Footnote-103623080
Ref: Core and Builtins<52>-Footnote-113623137
Ref: Core and Builtins<52>-Footnote-123623194
Node: Library<57>3623251
Ref: whatsnew/changelog id2233623380
Ref: 19bb3623380
Ref: Library<57>-Footnote-13623628
Node: Core and Builtins<53>3623684
Ref: whatsnew/changelog id2243623803
Ref: 19bc3623803
Ref: Core and Builtins<53>-Footnote-13624045
Node: Library<58>3624101
Ref: whatsnew/changelog id2253624230
Ref: 19bd3624230
Ref: Library<58>-Footnote-13624485
Node: Core and Builtins<54>3624541
Ref: whatsnew/changelog id2263624660
Ref: 19be3624660
Ref: Core and Builtins<54>-Footnote-13625489
Ref: Core and Builtins<54>-Footnote-23625545
Ref: Core and Builtins<54>-Footnote-33625601
Node: Library<59>3625656
Ref: whatsnew/changelog id2273625781
Ref: 19bf3625781
Ref: Library<59>-Footnote-13637583
Ref: Library<59>-Footnote-23637639
Ref: Library<59>-Footnote-33637695
Ref: Library<59>-Footnote-43637751
Ref: Library<59>-Footnote-53637807
Ref: Library<59>-Footnote-63637849
Ref: Library<59>-Footnote-73637905
Ref: Library<59>-Footnote-83637961
Ref: Library<59>-Footnote-93638017
Ref: Library<59>-Footnote-103638072
Ref: Library<59>-Footnote-113638128
Ref: Library<59>-Footnote-123638184
Ref: Library<59>-Footnote-133638240
Ref: Library<59>-Footnote-143638296
Ref: Library<59>-Footnote-153638353
Ref: Library<59>-Footnote-163638410
Ref: Library<59>-Footnote-173638466
Ref: Library<59>-Footnote-183638522
Ref: Library<59>-Footnote-193638579
Ref: Library<59>-Footnote-203638635
Ref: Library<59>-Footnote-213638692
Ref: Library<59>-Footnote-223638749
Ref: Library<59>-Footnote-233638806
Ref: Library<59>-Footnote-243638863
Ref: Library<59>-Footnote-253638919
Ref: Library<59>-Footnote-263638975
Ref: Library<59>-Footnote-273639032
Ref: Library<59>-Footnote-283639089
Ref: Library<59>-Footnote-293639146
Ref: Library<59>-Footnote-303639203
Ref: Library<59>-Footnote-313639260
Ref: Library<59>-Footnote-323639317
Ref: Library<59>-Footnote-333639374
Ref: Library<59>-Footnote-343639431
Ref: Library<59>-Footnote-353639488
Ref: Library<59>-Footnote-363639545
Ref: Library<59>-Footnote-373639588
Ref: Library<59>-Footnote-383639645
Ref: Library<59>-Footnote-393639702
Ref: Library<59>-Footnote-403639759
Ref: Library<59>-Footnote-413639816
Ref: Library<59>-Footnote-423639873
Ref: Library<59>-Footnote-433639930
Ref: Library<59>-Footnote-443639987
Ref: Library<59>-Footnote-453640044
Ref: Library<59>-Footnote-463640101
Ref: Library<59>-Footnote-473640158
Ref: Library<59>-Footnote-483640214
Ref: Library<59>-Footnote-493640271
Ref: Library<59>-Footnote-503640328
Ref: Library<59>-Footnote-513640384
Ref: Library<59>-Footnote-523640440
Ref: Library<59>-Footnote-533640497
Ref: Library<59>-Footnote-543640553
Ref: Library<59>-Footnote-553640610
Ref: Library<59>-Footnote-563640666
Ref: Library<59>-Footnote-573640723
Ref: Library<59>-Footnote-583640780
Ref: Library<59>-Footnote-593640836
Ref: Library<59>-Footnote-603640892
Ref: Library<59>-Footnote-613640948
Ref: Library<59>-Footnote-623641014
Ref: Library<59>-Footnote-633641080
Ref: Library<59>-Footnote-643641146
Ref: Library<59>-Footnote-653641212
Ref: Library<59>-Footnote-663641278
Ref: Library<59>-Footnote-673641344
Node: Documentation<16>3641410
Ref: whatsnew/changelog id2283641523
Ref: 19c83641523
Ref: Documentation<16>-Footnote-13641777
Ref: Documentation<16>-Footnote-23641833
Ref: Documentation<16>-Footnote-33641889
Node: Tests<15>3641945
Ref: whatsnew/changelog id2293642056
Ref: 19c93642056
Ref: Tests<15>-Footnote-13643251
Ref: Tests<15>-Footnote-23643306
Ref: Tests<15>-Footnote-33643361
Ref: Tests<15>-Footnote-43643417
Ref: Tests<15>-Footnote-53643473
Ref: Tests<15>-Footnote-63643529
Ref: Tests<15>-Footnote-73643585
Ref: Tests<15>-Footnote-83643641
Ref: Tests<15>-Footnote-93643697
Node: Build<18>3643753
Ref: whatsnew/changelog id2303643858
Ref: 19ca3643858
Ref: Build<18>-Footnote-13644770
Ref: Build<18>-Footnote-23644826
Ref: Build<18>-Footnote-33644881
Ref: Build<18>-Footnote-43644937
Ref: Build<18>-Footnote-53644992
Ref: Build<18>-Footnote-63645048
Ref: Build<18>-Footnote-73645104
Ref: Build<18>-Footnote-83645160
Ref: Build<18>-Footnote-93645216
Node: Windows<16>3645272
Ref: whatsnew/changelog id2313645376
Ref: 19cb3645376
Ref: Windows<16>-Footnote-13646460
Ref: Windows<16>-Footnote-23646516
Ref: Windows<16>-Footnote-33646572
Ref: Windows<16>-Footnote-43646628
Node: macOS<9>3646684
Ref: whatsnew/changelog id2323646786
Ref: 19cc3646786
Ref: macOS<9>-Footnote-13646918
Node: IDLE<9>3646974
Ref: whatsnew/changelog id2333647080
Ref: 19cd3647080
Ref: IDLE<9>-Footnote-13647264
Node: Tools/Demos<16>3647319
Ref: whatsnew/changelog id2343647426
Ref: 19ce3647426
Ref: Tools/Demos<16>-Footnote-13647669
Ref: Tools/Demos<16>-Footnote-23647725
Node: C API<18>3647790
Ref: whatsnew/changelog id2353647881
Ref: 19cf3647881
Ref: C API<18>-Footnote-13648452
Ref: C API<18>-Footnote-23648508
Node: Python 3 13 0 alpha 43648564
Ref: whatsnew/changelog python-3-13-0-alpha-43648691
Ref: 19d43648691
Node: Security<19>3649074
Ref: whatsnew/changelog id2363649174
Ref: 19d53649174
Ref: Security<19>-Footnote-13649435
Ref: Security<19>-Footnote-23649491
Node: Core and Builtins<55>3649547
Ref: whatsnew/changelog id2373649667
Ref: 19d63649667
Ref: Core and Builtins<55>-Footnote-13654975
Ref: Core and Builtins<55>-Footnote-23655031
Ref: Core and Builtins<55>-Footnote-33655087
Ref: Core and Builtins<55>-Footnote-43655143
Ref: Core and Builtins<55>-Footnote-53655199
Ref: Core and Builtins<55>-Footnote-63655255
Ref: Core and Builtins<55>-Footnote-73655311
Ref: Core and Builtins<55>-Footnote-83655367
Ref: Core and Builtins<55>-Footnote-93655423
Ref: Core and Builtins<55>-Footnote-103655479
Ref: Core and Builtins<55>-Footnote-113655535
Ref: Core and Builtins<55>-Footnote-123655592
Ref: Core and Builtins<55>-Footnote-133655649
Ref: Core and Builtins<55>-Footnote-143655706
Ref: Core and Builtins<55>-Footnote-153655763
Ref: Core and Builtins<55>-Footnote-163655820
Ref: Core and Builtins<55>-Footnote-173655877
Ref: Core and Builtins<55>-Footnote-183655934
Ref: Core and Builtins<55>-Footnote-193655991
Ref: Core and Builtins<55>-Footnote-203656048
Ref: Core and Builtins<55>-Footnote-213656105
Ref: Core and Builtins<55>-Footnote-223656162
Ref: Core and Builtins<55>-Footnote-233656219
Ref: Core and Builtins<55>-Footnote-243656276
Ref: Core and Builtins<55>-Footnote-253656333
Ref: Core and Builtins<55>-Footnote-263656390
Ref: Core and Builtins<55>-Footnote-273656447
Ref: Core and Builtins<55>-Footnote-283656510
Ref: Core and Builtins<55>-Footnote-293656567
Ref: Core and Builtins<55>-Footnote-303656623
Node: Library<60>3656680
Ref: whatsnew/changelog id2383656805
Ref: 19d93656805
Ref: Library<60>-Footnote-13670771
Ref: Library<60>-Footnote-23670827
Ref: Library<60>-Footnote-33670883
Ref: Library<60>-Footnote-43670939
Ref: Library<60>-Footnote-53670995
Ref: Library<60>-Footnote-63671051
Ref: Library<60>-Footnote-73671107
Ref: Library<60>-Footnote-83671163
Ref: Library<60>-Footnote-93671218
Ref: Library<60>-Footnote-103671273
Ref: Library<60>-Footnote-113671330
Ref: Library<60>-Footnote-123671386
Ref: Library<60>-Footnote-133671443
Ref: Library<60>-Footnote-143671499
Ref: Library<60>-Footnote-153671556
Ref: Library<60>-Footnote-163671613
Ref: Library<60>-Footnote-173671670
Ref: Library<60>-Footnote-183671727
Ref: Library<60>-Footnote-193671784
Ref: Library<60>-Footnote-203671840
Ref: Library<60>-Footnote-213671897
Ref: Library<60>-Footnote-223671954
Ref: Library<60>-Footnote-233672010
Ref: Library<60>-Footnote-243672067
Ref: Library<60>-Footnote-253672124
Ref: Library<60>-Footnote-263672180
Ref: Library<60>-Footnote-273672236
Ref: Library<60>-Footnote-283672292
Ref: Library<60>-Footnote-293672349
Ref: Library<60>-Footnote-303672405
Ref: Library<60>-Footnote-313672462
Ref: Library<60>-Footnote-323672519
Ref: Library<60>-Footnote-333672576
Ref: Library<60>-Footnote-343672633
Ref: Library<60>-Footnote-353672690
Ref: Library<60>-Footnote-363672747
Ref: Library<60>-Footnote-373672803
Ref: Library<60>-Footnote-383672860
Ref: Library<60>-Footnote-393672917
Ref: Library<60>-Footnote-403672974
Ref: Library<60>-Footnote-413673031
Ref: Library<60>-Footnote-423673088
Ref: Library<60>-Footnote-433673132
Ref: Library<60>-Footnote-443673189
Ref: Library<60>-Footnote-453673246
Ref: Library<60>-Footnote-463673303
Ref: Library<60>-Footnote-473673360
Ref: Library<60>-Footnote-483673416
Ref: Library<60>-Footnote-493673473
Ref: Library<60>-Footnote-503673530
Ref: Library<60>-Footnote-513673586
Ref: Library<60>-Footnote-523673643
Ref: Library<60>-Footnote-533673700
Ref: Library<60>-Footnote-543673756
Ref: Library<60>-Footnote-553673813
Ref: Library<60>-Footnote-563673870
Ref: Library<60>-Footnote-573673927
Ref: Library<60>-Footnote-583673983
Ref: Library<60>-Footnote-593674040
Ref: Library<60>-Footnote-603674096
Ref: Library<60>-Footnote-613674153
Ref: Library<60>-Footnote-623674210
Ref: Library<60>-Footnote-633674267
Ref: Library<60>-Footnote-643674323
Ref: Library<60>-Footnote-653674379
Ref: Library<60>-Footnote-663674436
Ref: Library<60>-Footnote-673674493
Ref: Library<60>-Footnote-683674549
Ref: Library<60>-Footnote-693674605
Ref: Library<60>-Footnote-703674662
Ref: Library<60>-Footnote-713674719
Ref: Library<60>-Footnote-723674776
Ref: Library<60>-Footnote-733674832
Ref: Library<60>-Footnote-743674889
Ref: Library<60>-Footnote-753674945
Ref: Library<60>-Footnote-763675002
Ref: Library<60>-Footnote-773675058
Node: Documentation<17>3675124
Ref: whatsnew/changelog id2393675237
Ref: 19e93675237
Ref: Documentation<17>-Footnote-13675808
Ref: Documentation<17>-Footnote-23675864
Node: Tests<16>3675920
Ref: whatsnew/changelog id2403676031
Ref: 19ea3676031
Ref: Tests<16>-Footnote-13676423
Ref: Tests<16>-Footnote-23676479
Node: Build<19>3676535
Ref: whatsnew/changelog id2413676640
Ref: 19eb3676640
Ref: Build<19>-Footnote-13677178
Ref: Build<19>-Footnote-23677234
Ref: Build<19>-Footnote-33677290
Ref: Build<19>-Footnote-43677346
Node: Windows<17>3677402
Ref: whatsnew/changelog id2423677507
Ref: 19ec3677507
Ref: Windows<17>-Footnote-13678260
Ref: Windows<17>-Footnote-23678316
Ref: Windows<17>-Footnote-33678372
Ref: Windows<17>-Footnote-43678428
Ref: Windows<17>-Footnote-53678484
Ref: Windows<17>-Footnote-63678540
Ref: Windows<17>-Footnote-73678596
Node: macOS<10>3678651
Ref: whatsnew/changelog id2433678755
Ref: 19ed3678755
Ref: macOS<10>-Footnote-13679294
Ref: macOS<10>-Footnote-23679350
Ref: macOS<10>-Footnote-33679406
Ref: macOS<10>-Footnote-43679462
Node: IDLE<10>3679517
Ref: whatsnew/changelog id2443679625
Ref: 19ef3679625
Ref: IDLE<10>-Footnote-13679960
Ref: IDLE<10>-Footnote-23680015
Node: Tools/Demos<17>3680071
Ref: whatsnew/changelog id2453680179
Ref: 19f03680179
Ref: Tools/Demos<17>-Footnote-13680792
Ref: Tools/Demos<17>-Footnote-23680848
Ref: Tools/Demos<17>-Footnote-33680904
Node: C API<19>3680960
Ref: whatsnew/changelog id2463681051
Ref: 19f23681051
Ref: C API<19>-Footnote-13682995
Ref: C API<19>-Footnote-23683051
Ref: C API<19>-Footnote-33683107
Ref: C API<19>-Footnote-43683163
Ref: C API<19>-Footnote-53683219
Ref: C API<19>-Footnote-63683275
Ref: C API<19>-Footnote-73683331
Node: Python 3 13 0 alpha 33683387
Ref: whatsnew/changelog python-3-13-0-alpha-33683514
Ref: 19f53683514
Node: Security<20>3683865
Ref: whatsnew/changelog id2473683965
Ref: 19f63683965
Ref: Security<20>-Footnote-13684254
Ref: Security<20>-Footnote-23684310
Node: Core and Builtins<56>3684366
Ref: whatsnew/changelog id2483684486
Ref: 19f73684486
Ref: Core and Builtins<56>-Footnote-13691881
Ref: Core and Builtins<56>-Footnote-23691937
Ref: Core and Builtins<56>-Footnote-33691993
Ref: Core and Builtins<56>-Footnote-43692049
Ref: Core and Builtins<56>-Footnote-53692105
Ref: Core and Builtins<56>-Footnote-63692160
Ref: Core and Builtins<56>-Footnote-73692202
Ref: Core and Builtins<56>-Footnote-83692258
Ref: Core and Builtins<56>-Footnote-93692314
Ref: Core and Builtins<56>-Footnote-103692370
Ref: Core and Builtins<56>-Footnote-113692427
Ref: Core and Builtins<56>-Footnote-123692483
Ref: Core and Builtins<56>-Footnote-133692540
Ref: Core and Builtins<56>-Footnote-143692597
Ref: Core and Builtins<56>-Footnote-153692654
Ref: Core and Builtins<56>-Footnote-163692711
Ref: Core and Builtins<56>-Footnote-173692768
Ref: Core and Builtins<56>-Footnote-183692825
Ref: Core and Builtins<56>-Footnote-193692882
Ref: Core and Builtins<56>-Footnote-203692939
Ref: Core and Builtins<56>-Footnote-213692996
Ref: Core and Builtins<56>-Footnote-223693053
Ref: Core and Builtins<56>-Footnote-233693110
Ref: Core and Builtins<56>-Footnote-243693167
Ref: Core and Builtins<56>-Footnote-253693223
Ref: Core and Builtins<56>-Footnote-263693280
Ref: Core and Builtins<56>-Footnote-273693337
Ref: Core and Builtins<56>-Footnote-283693393
Ref: Core and Builtins<56>-Footnote-293693450
Ref: Core and Builtins<56>-Footnote-303693507
Ref: Core and Builtins<56>-Footnote-313693564
Ref: Core and Builtins<56>-Footnote-323693621
Ref: Core and Builtins<56>-Footnote-333693678
Ref: Core and Builtins<56>-Footnote-343693734
Ref: Core and Builtins<56>-Footnote-353693791
Ref: Core and Builtins<56>-Footnote-363693848
Ref: Core and Builtins<56>-Footnote-373693905
Ref: Core and Builtins<56>-Footnote-383693962
Ref: Core and Builtins<56>-Footnote-393694018
Ref: Core and Builtins<56>-Footnote-403694075
Ref: Core and Builtins<56>-Footnote-413694132
Ref: Core and Builtins<56>-Footnote-423694189
Ref: Core and Builtins<56>-Footnote-433694245
Ref: Core and Builtins<56>-Footnote-443694311
Ref: Core and Builtins<56>-Footnote-453694377
Ref: Core and Builtins<56>-Footnote-463694420
Node: Library<61>3694486
Ref: whatsnew/changelog id2493694611
Ref: 19fc3694611
Ref: Library<61>-Footnote-13719832
Ref: Library<61>-Footnote-23719888
Ref: Library<61>-Footnote-33719944
Ref: Library<61>-Footnote-43720000
Ref: Library<61>-Footnote-53720056
Ref: Library<61>-Footnote-63720112
Ref: Library<61>-Footnote-73720168
Ref: Library<61>-Footnote-83720224
Ref: Library<61>-Footnote-93720280
Ref: Library<61>-Footnote-103720336
Ref: Library<61>-Footnote-113720392
Ref: Library<61>-Footnote-123720449
Ref: Library<61>-Footnote-133720506
Ref: Library<61>-Footnote-143720563
Ref: Library<61>-Footnote-153720620
Ref: Library<61>-Footnote-163720677
Ref: Library<61>-Footnote-173720734
Ref: Library<61>-Footnote-183720791
Ref: Library<61>-Footnote-193720848
Ref: Library<61>-Footnote-203720905
Ref: Library<61>-Footnote-213720961
Ref: Library<61>-Footnote-223721018
Ref: Library<61>-Footnote-233721074
Ref: Library<61>-Footnote-243721131
Ref: Library<61>-Footnote-253721188
Ref: Library<61>-Footnote-263721245
Ref: Library<61>-Footnote-273721302
Ref: Library<61>-Footnote-283721359
Ref: Library<61>-Footnote-293721416
Ref: Library<61>-Footnote-303721473
Ref: Library<61>-Footnote-313721530
Ref: Library<61>-Footnote-323721587
Ref: Library<61>-Footnote-333721643
Ref: Library<61>-Footnote-343721700
Ref: Library<61>-Footnote-353721757
Ref: Library<61>-Footnote-363721814
Ref: Library<61>-Footnote-373721870
Ref: Library<61>-Footnote-383721927
Ref: Library<61>-Footnote-393721984
Ref: Library<61>-Footnote-403722041
Ref: Library<61>-Footnote-413722098
Ref: Library<61>-Footnote-423722155
Ref: Library<61>-Footnote-433722212
Ref: Library<61>-Footnote-443722269
Ref: Library<61>-Footnote-453722326
Ref: Library<61>-Footnote-463722383
Ref: Library<61>-Footnote-473722439
Ref: Library<61>-Footnote-483722496
Ref: Library<61>-Footnote-493722552
Ref: Library<61>-Footnote-503722609
Ref: Library<61>-Footnote-513722666
Ref: Library<61>-Footnote-523722723
Ref: Library<61>-Footnote-533722780
Ref: Library<61>-Footnote-543722837
Ref: Library<61>-Footnote-553722894
Ref: Library<61>-Footnote-563722950
Ref: Library<61>-Footnote-573723007
Ref: Library<61>-Footnote-583723063
Ref: Library<61>-Footnote-593723119
Ref: Library<61>-Footnote-603723175
Ref: Library<61>-Footnote-613723232
Ref: Library<61>-Footnote-623723289
Ref: Library<61>-Footnote-633723345
Ref: Library<61>-Footnote-643723401
Ref: Library<61>-Footnote-653723458
Ref: Library<61>-Footnote-663723515
Ref: Library<61>-Footnote-673723572
Ref: Library<61>-Footnote-683723629
Ref: Library<61>-Footnote-693723686
Ref: Library<61>-Footnote-703723743
Ref: Library<61>-Footnote-713723799
Ref: Library<61>-Footnote-723723856
Ref: Library<61>-Footnote-733723913
Ref: Library<61>-Footnote-743723970
Ref: Library<61>-Footnote-753724027
Ref: Library<61>-Footnote-763724084
Ref: Library<61>-Footnote-773724141
Ref: Library<61>-Footnote-783724197
Ref: Library<61>-Footnote-793724254
Ref: Library<61>-Footnote-803724311
Ref: Library<61>-Footnote-813724368
Ref: Library<61>-Footnote-823724424
Ref: Library<61>-Footnote-833724481
Ref: Library<61>-Footnote-843724538
Ref: Library<61>-Footnote-853724595
Ref: Library<61>-Footnote-863724652
Ref: Library<61>-Footnote-873724708
Ref: Library<61>-Footnote-883724765
Ref: Library<61>-Footnote-893724821
Ref: Library<61>-Footnote-903724878
Ref: Library<61>-Footnote-913724935
Ref: Library<61>-Footnote-923724992
Ref: Library<61>-Footnote-933725049
Ref: Library<61>-Footnote-943725106
Ref: Library<61>-Footnote-953725162
Ref: Library<61>-Footnote-963725219
Ref: Library<61>-Footnote-973725275
Ref: Library<61>-Footnote-983725332
Ref: Library<61>-Footnote-993725388
Ref: Library<61>-Footnote-1003725444
Ref: Library<61>-Footnote-1013725501
Ref: Library<61>-Footnote-1023725559
Ref: Library<61>-Footnote-1033725617
Ref: Library<61>-Footnote-1043725675
Ref: Library<61>-Footnote-1053725733
Ref: Library<61>-Footnote-1063725790
Ref: Library<61>-Footnote-1073725847
Ref: Library<61>-Footnote-1083725905
Ref: Library<61>-Footnote-1093725963
Ref: Library<61>-Footnote-1103726021
Ref: Library<61>-Footnote-1113726078
Ref: Library<61>-Footnote-1123726136
Ref: Library<61>-Footnote-1133726194
Ref: Library<61>-Footnote-1143726251
Ref: Library<61>-Footnote-1153726309
Ref: Library<61>-Footnote-1163726353
Ref: Library<61>-Footnote-1173726411
Ref: Library<61>-Footnote-1183726468
Ref: Library<61>-Footnote-1193726525
Ref: Library<61>-Footnote-1203726582
Ref: Library<61>-Footnote-1213726649
Ref: Library<61>-Footnote-1223726716
Ref: Library<61>-Footnote-1233726783
Ref: Library<61>-Footnote-1243726850
Ref: Library<61>-Footnote-1253726917
Ref: Library<61>-Footnote-1263726984
Ref: Library<61>-Footnote-1273727051
Ref: Library<61>-Footnote-1283727118
Ref: Library<61>-Footnote-1293727185
Ref: Library<61>-Footnote-1303727252
Ref: Library<61>-Footnote-1313727319
Ref: Library<61>-Footnote-1323727386
Ref: Library<61>-Footnote-1333727453
Ref: Library<61>-Footnote-1343727520
Node: Documentation<18>3727587
Ref: whatsnew/changelog id2503727700
Ref: 1a163727700
Ref: Documentation<18>-Footnote-13728268
Ref: Documentation<18>-Footnote-23728324
Ref: Documentation<18>-Footnote-33728380
Ref: Documentation<18>-Footnote-43728435
Node: Tests<17>3728493
Ref: whatsnew/changelog id2513728604
Ref: 1a173728604
Ref: Tests<17>-Footnote-13730549
Ref: Tests<17>-Footnote-23730605
Ref: Tests<17>-Footnote-33730661
Ref: Tests<17>-Footnote-43730717
Ref: Tests<17>-Footnote-53730772
Ref: Tests<17>-Footnote-63730828
Ref: Tests<17>-Footnote-73730884
Ref: Tests<17>-Footnote-83730940
Ref: Tests<17>-Footnote-93730996
Ref: Tests<17>-Footnote-103731052
Node: Build<20>3731118
Ref: whatsnew/changelog id2523731223
Ref: 1a183731223
Ref: Build<20>-Footnote-13732467
Ref: Build<20>-Footnote-23732523
Ref: Build<20>-Footnote-33732579
Ref: Build<20>-Footnote-43732635
Ref: Build<20>-Footnote-53732691
Ref: Build<20>-Footnote-63732747
Ref: Build<20>-Footnote-73732803
Ref: Build<20>-Footnote-83732868
Node: Windows<18>3732933
Ref: whatsnew/changelog id2533733038
Ref: 1a193733038
Ref: Windows<18>-Footnote-13734879
Ref: Windows<18>-Footnote-23734935
Ref: Windows<18>-Footnote-33734991
Ref: Windows<18>-Footnote-43735047
Ref: Windows<18>-Footnote-53735103
Ref: Windows<18>-Footnote-63735158
Ref: Windows<18>-Footnote-73735213
Ref: Windows<18>-Footnote-83735269
Ref: Windows<18>-Footnote-93735325
Ref: Windows<18>-Footnote-103735380
Ref: Windows<18>-Footnote-113735436
Node: macOS<11>3735502
Ref: whatsnew/changelog id2543735606
Ref: 1a1a3735606
Ref: macOS<11>-Footnote-13738014
Ref: macOS<11>-Footnote-23738070
Ref: macOS<11>-Footnote-33738126
Ref: macOS<11>-Footnote-43738182
Ref: macOS<11>-Footnote-53738237
Ref: macOS<11>-Footnote-63738292
Ref: macOS<11>-Footnote-73738347
Ref: macOS<11>-Footnote-83738403
Ref: macOS<11>-Footnote-93738459
Ref: macOS<11>-Footnote-103738515
Ref: macOS<11>-Footnote-113738572
Ref: macOS<11>-Footnote-123738629
Node: IDLE<11>3738686
Ref: whatsnew/changelog id2553738788
Ref: 1a1b3738788
Ref: IDLE<11>-Footnote-13739368
Ref: IDLE<11>-Footnote-23739423
Ref: IDLE<11>-Footnote-33739479
Ref: IDLE<11>-Footnote-43739535
Ref: IDLE<11>-Footnote-53739591
Ref: IDLE<11>-Footnote-63739647
Node: C API<20>3739712
Ref: whatsnew/changelog id2563739796
Ref: 1a1c3739796
Ref: C API<20>-Footnote-13740519
Ref: C API<20>-Footnote-23740575
Ref: C API<20>-Footnote-33740631
Ref: C API<20>-Footnote-43740687
Node: Python 3 13 0 alpha 23740742
Ref: whatsnew/changelog python-3-13-0-alpha-23740869
Ref: 1a1d3740869
Node: Core and Builtins<57>3741190
Ref: whatsnew/changelog id2573741289
Ref: 1a1e3741289
Ref: Core and Builtins<57>-Footnote-13749125
Ref: Core and Builtins<57>-Footnote-23749181
Ref: Core and Builtins<57>-Footnote-33749237
Ref: Core and Builtins<57>-Footnote-43749293
Ref: Core and Builtins<57>-Footnote-53749349
Ref: Core and Builtins<57>-Footnote-63749405
Ref: Core and Builtins<57>-Footnote-73749461
Ref: Core and Builtins<57>-Footnote-83749517
Ref: Core and Builtins<57>-Footnote-93749572
Ref: Core and Builtins<57>-Footnote-103749627
Ref: Core and Builtins<57>-Footnote-113749683
Ref: Core and Builtins<57>-Footnote-123749740
Ref: Core and Builtins<57>-Footnote-133749797
Ref: Core and Builtins<57>-Footnote-143749854
Ref: Core and Builtins<57>-Footnote-153749911
Ref: Core and Builtins<57>-Footnote-163749968
Ref: Core and Builtins<57>-Footnote-173750025
Ref: Core and Builtins<57>-Footnote-183750082
Ref: Core and Builtins<57>-Footnote-193750139
Ref: Core and Builtins<57>-Footnote-203750196
Ref: Core and Builtins<57>-Footnote-213750253
Ref: Core and Builtins<57>-Footnote-223750310
Ref: Core and Builtins<57>-Footnote-233750367
Ref: Core and Builtins<57>-Footnote-243750424
Ref: Core and Builtins<57>-Footnote-253750481
Ref: Core and Builtins<57>-Footnote-263750538
Ref: Core and Builtins<57>-Footnote-273750595
Ref: Core and Builtins<57>-Footnote-283750652
Ref: Core and Builtins<57>-Footnote-293750709
Ref: Core and Builtins<57>-Footnote-303750765
Ref: Core and Builtins<57>-Footnote-313750821
Ref: Core and Builtins<57>-Footnote-323750878
Ref: Core and Builtins<57>-Footnote-333750935
Ref: Core and Builtins<57>-Footnote-343750992
Ref: Core and Builtins<57>-Footnote-353751049
Ref: Core and Builtins<57>-Footnote-363751106
Ref: Core and Builtins<57>-Footnote-373751163
Ref: Core and Builtins<57>-Footnote-383751220
Ref: Core and Builtins<57>-Footnote-393751277
Ref: Core and Builtins<57>-Footnote-403751334
Ref: Core and Builtins<57>-Footnote-413751391
Ref: Core and Builtins<57>-Footnote-423751448
Ref: Core and Builtins<57>-Footnote-433751505
Ref: Core and Builtins<57>-Footnote-443751561
Ref: Core and Builtins<57>-Footnote-453751627
Ref: Core and Builtins<57>-Footnote-463751684
Ref: Core and Builtins<57>-Footnote-473751750
Ref: Core and Builtins<57>-Footnote-483751807
Ref: Core and Builtins<57>-Footnote-493751864
Ref: Core and Builtins<57>-Footnote-503751921
Node: Library<62>3751987
Ref: whatsnew/changelog id2583752104
Ref: 1a213752104
Ref: Library<62>-Footnote-13762674
Ref: Library<62>-Footnote-23762730
Ref: Library<62>-Footnote-33762786
Ref: Library<62>-Footnote-43762842
Ref: Library<62>-Footnote-53762898
Ref: Library<62>-Footnote-63762954
Ref: Library<62>-Footnote-73763010
Ref: Library<62>-Footnote-83763066
Ref: Library<62>-Footnote-93763122
Ref: Library<62>-Footnote-103763178
Ref: Library<62>-Footnote-113763235
Ref: Library<62>-Footnote-123763291
Ref: Library<62>-Footnote-133763348
Ref: Library<62>-Footnote-143763405
Ref: Library<62>-Footnote-153763462
Ref: Library<62>-Footnote-163763519
Ref: Library<62>-Footnote-173763576
Ref: Library<62>-Footnote-183763633
Ref: Library<62>-Footnote-193763690
Ref: Library<62>-Footnote-203763746
Ref: Library<62>-Footnote-213763803
Ref: Library<62>-Footnote-223763860
Ref: Library<62>-Footnote-233763916
Ref: Library<62>-Footnote-243763973
Ref: Library<62>-Footnote-253764029
Ref: Library<62>-Footnote-263764086
Ref: Library<62>-Footnote-273764143
Ref: Library<62>-Footnote-283764200
Ref: Library<62>-Footnote-293764257
Ref: Library<62>-Footnote-303764314
Ref: Library<62>-Footnote-313764371
Ref: Library<62>-Footnote-323764428
Ref: Library<62>-Footnote-333764485
Ref: Library<62>-Footnote-343764542
Ref: Library<62>-Footnote-353764599
Ref: Library<62>-Footnote-363764656
Ref: Library<62>-Footnote-373764713
Ref: Library<62>-Footnote-383764770
Ref: Library<62>-Footnote-393764826
Ref: Library<62>-Footnote-403764882
Ref: Library<62>-Footnote-413764939
Ref: Library<62>-Footnote-423764996
Ref: Library<62>-Footnote-433765053
Ref: Library<62>-Footnote-443765109
Ref: Library<62>-Footnote-453765165
Ref: Library<62>-Footnote-463765222
Ref: Library<62>-Footnote-473765279
Ref: Library<62>-Footnote-483765336
Ref: Library<62>-Footnote-493765393
Ref: Library<62>-Footnote-503765449
Ref: Library<62>-Footnote-513765506
Ref: Library<62>-Footnote-523765563
Ref: Library<62>-Footnote-533765620
Ref: Library<62>-Footnote-543765676
Ref: Library<62>-Footnote-553765732
Ref: Library<62>-Footnote-563765788
Ref: Library<62>-Footnote-573765845
Ref: Library<62>-Footnote-583765902
Ref: Library<62>-Footnote-593765958
Ref: Library<62>-Footnote-603766014
Ref: Library<62>-Footnote-613766099
Ref: Library<62>-Footnote-623766155
Node: Tests<18>3766211
Ref: whatsnew/changelog id2593766316
Ref: 1a323766316
Ref: Tests<18>-Footnote-13767902
Ref: Tests<18>-Footnote-23767958
Ref: Tests<18>-Footnote-33768014
Ref: Tests<18>-Footnote-43768070
Ref: Tests<18>-Footnote-53768126
Ref: Tests<18>-Footnote-63768182
Ref: Tests<18>-Footnote-73768238
Ref: Tests<18>-Footnote-83768294
Node: Build<21>3768350
Ref: whatsnew/changelog id2603768455
Ref: 1a333768455
Ref: Build<21>-Footnote-13769441
Ref: Build<21>-Footnote-23769496
Ref: Build<21>-Footnote-33769552
Ref: Build<21>-Footnote-43769602
Ref: Build<21>-Footnote-53769658
Ref: Build<21>-Footnote-63769714
Node: Windows<19>3769769
Ref: whatsnew/changelog id2613769874
Ref: 1a343769874
Ref: Windows<19>-Footnote-13770328
Ref: Windows<19>-Footnote-23770384
Ref: Windows<19>-Footnote-33770440
Node: macOS<12>3770496
Ref: whatsnew/changelog id2623770600
Ref: 1a363770600
Ref: macOS<12>-Footnote-13771531
Ref: macOS<12>-Footnote-23771586
Ref: macOS<12>-Footnote-33771642
Ref: macOS<12>-Footnote-43771698
Ref: macOS<12>-Footnote-53771753
Node: IDLE<12>3771808
Ref: whatsnew/changelog id2633771916
Ref: 1a373771916
Ref: IDLE<12>-Footnote-13772254
Node: Tools/Demos<18>3772319
Ref: whatsnew/changelog id2643772427
Ref: 1a383772427
Ref: Tools/Demos<18>-Footnote-13772784
Node: C API<21>3772840
Ref: whatsnew/changelog id2653772931
Ref: 1a393772931
Ref: C API<21>-Footnote-13778303
Ref: C API<21>-Footnote-23778359
Ref: C API<21>-Footnote-33778415
Ref: C API<21>-Footnote-43778471
Ref: C API<21>-Footnote-53778527
Ref: C API<21>-Footnote-63778583
Ref: C API<21>-Footnote-73778639
Ref: C API<21>-Footnote-83778695
Ref: C API<21>-Footnote-93778751
Ref: C API<21>-Footnote-103778807
Ref: C API<21>-Footnote-113778864
Ref: C API<21>-Footnote-123778907
Ref: C API<21>-Footnote-133778964
Ref: C API<21>-Footnote-143779021
Ref: C API<21>-Footnote-153779078
Ref: C API<21>-Footnote-163779135
Ref: C API<21>-Footnote-173779192
Ref: C API<21>-Footnote-183779248
Ref: C API<21>-Footnote-193779304
Ref: C API<21>-Footnote-203779361
Node: Python 3 13 0 alpha 13779417
Ref: whatsnew/changelog python-3-13-0-alpha-13779543
Ref: 1a3a3779543
Node: Security<21>3779926
Ref: whatsnew/changelog id2663780026
Ref: 1a3b3780026
Ref: Security<21>-Footnote-13781294
Ref: Security<21>-Footnote-23781350
Ref: Security<21>-Footnote-33781406
Ref: Security<21>-Footnote-43781462
Ref: Security<21>-Footnote-53781518
Ref: Security<21>-Footnote-63781574
Ref: Security<21>-Footnote-73781629
Node: Core and Builtins<58>3781685
Ref: whatsnew/changelog id2673781805
Ref: 1a3c3781805
Ref: Core and Builtins<58>-Footnote-13812589
Ref: Core and Builtins<58>-Footnote-23812645
Ref: Core and Builtins<58>-Footnote-33812701
Ref: Core and Builtins<58>-Footnote-43812757
Ref: Core and Builtins<58>-Footnote-53812813
Ref: Core and Builtins<58>-Footnote-63812869
Ref: Core and Builtins<58>-Footnote-73812925
Ref: Core and Builtins<58>-Footnote-83812981
Ref: Core and Builtins<58>-Footnote-93813037
Ref: Core and Builtins<58>-Footnote-103813093
Ref: Core and Builtins<58>-Footnote-113813150
Ref: Core and Builtins<58>-Footnote-123813207
Ref: Core and Builtins<58>-Footnote-133813264
Ref: Core and Builtins<58>-Footnote-143813321
Ref: Core and Builtins<58>-Footnote-153813378
Ref: Core and Builtins<58>-Footnote-163813435
Ref: Core and Builtins<58>-Footnote-173813492
Ref: Core and Builtins<58>-Footnote-183813549
Ref: Core and Builtins<58>-Footnote-193813606
Ref: Core and Builtins<58>-Footnote-203813663
Ref: Core and Builtins<58>-Footnote-213813720
Ref: Core and Builtins<58>-Footnote-223813777
Ref: Core and Builtins<58>-Footnote-233813834
Ref: Core and Builtins<58>-Footnote-243813891
Ref: Core and Builtins<58>-Footnote-253813948
Ref: Core and Builtins<58>-Footnote-263814005
Ref: Core and Builtins<58>-Footnote-273814062
Ref: Core and Builtins<58>-Footnote-283814119
Ref: Core and Builtins<58>-Footnote-293814176
Ref: Core and Builtins<58>-Footnote-303814233
Ref: Core and Builtins<58>-Footnote-313814290
Ref: Core and Builtins<58>-Footnote-323814347
Ref: Core and Builtins<58>-Footnote-333814404
Ref: Core and Builtins<58>-Footnote-343814461
Ref: Core and Builtins<58>-Footnote-353814518
Ref: Core and Builtins<58>-Footnote-363814575
Ref: Core and Builtins<58>-Footnote-373814632
Ref: Core and Builtins<58>-Footnote-383814689
Ref: Core and Builtins<58>-Footnote-393814746
Ref: Core and Builtins<58>-Footnote-403814803
Ref: Core and Builtins<58>-Footnote-413814860
Ref: Core and Builtins<58>-Footnote-423814917
Ref: Core and Builtins<58>-Footnote-433814974
Ref: Core and Builtins<58>-Footnote-443815031
Ref: Core and Builtins<58>-Footnote-453815087
Ref: Core and Builtins<58>-Footnote-463815144
Ref: Core and Builtins<58>-Footnote-473815201
Ref: Core and Builtins<58>-Footnote-483815258
Ref: Core and Builtins<58>-Footnote-493815315
Ref: Core and Builtins<58>-Footnote-503815372
Ref: Core and Builtins<58>-Footnote-513815429
Ref: Core and Builtins<58>-Footnote-523815486
Ref: Core and Builtins<58>-Footnote-533815543
Ref: Core and Builtins<58>-Footnote-543815600
Ref: Core and Builtins<58>-Footnote-553815657
Ref: Core and Builtins<58>-Footnote-563815714
Ref: Core and Builtins<58>-Footnote-573815771
Ref: Core and Builtins<58>-Footnote-583815828
Ref: Core and Builtins<58>-Footnote-593815885
Ref: Core and Builtins<58>-Footnote-603815942
Ref: Core and Builtins<58>-Footnote-613815999
Ref: Core and Builtins<58>-Footnote-623816056
Ref: Core and Builtins<58>-Footnote-633816113
Ref: Core and Builtins<58>-Footnote-643816170
Ref: Core and Builtins<58>-Footnote-653816226
Ref: Core and Builtins<58>-Footnote-663816283
Ref: Core and Builtins<58>-Footnote-673816340
Ref: Core and Builtins<58>-Footnote-683816396
Ref: Core and Builtins<58>-Footnote-693816453
Ref: Core and Builtins<58>-Footnote-703816510
Ref: Core and Builtins<58>-Footnote-713816567
Ref: Core and Builtins<58>-Footnote-723816624
Ref: Core and Builtins<58>-Footnote-733816681
Ref: Core and Builtins<58>-Footnote-743816737
Ref: Core and Builtins<58>-Footnote-753816794
Ref: Core and Builtins<58>-Footnote-763816851
Ref: Core and Builtins<58>-Footnote-773816908
Ref: Core and Builtins<58>-Footnote-783816965
Ref: Core and Builtins<58>-Footnote-793817022
Ref: Core and Builtins<58>-Footnote-803817079
Ref: Core and Builtins<58>-Footnote-813817136
Ref: Core and Builtins<58>-Footnote-823817193
Ref: Core and Builtins<58>-Footnote-833817250
Ref: Core and Builtins<58>-Footnote-843817307
Ref: Core and Builtins<58>-Footnote-853817350
Ref: Core and Builtins<58>-Footnote-863817407
Ref: Core and Builtins<58>-Footnote-873817464
Ref: Core and Builtins<58>-Footnote-883817521
Ref: Core and Builtins<58>-Footnote-893817577
Ref: Core and Builtins<58>-Footnote-903817634
Ref: Core and Builtins<58>-Footnote-913817691
Ref: Core and Builtins<58>-Footnote-923817748
Ref: Core and Builtins<58>-Footnote-933817805
Ref: Core and Builtins<58>-Footnote-943817862
Ref: Core and Builtins<58>-Footnote-953817919
Ref: Core and Builtins<58>-Footnote-963817976
Ref: Core and Builtins<58>-Footnote-973818033
Ref: Core and Builtins<58>-Footnote-983818090
Ref: Core and Builtins<58>-Footnote-993818147
Ref: Core and Builtins<58>-Footnote-1003818204
Ref: Core and Builtins<58>-Footnote-1013818262
Ref: Core and Builtins<58>-Footnote-1023818320
Ref: Core and Builtins<58>-Footnote-1033818378
Ref: Core and Builtins<58>-Footnote-1043818436
Ref: Core and Builtins<58>-Footnote-1053818494
Ref: Core and Builtins<58>-Footnote-1063818552
Ref: Core and Builtins<58>-Footnote-1073818609
Ref: Core and Builtins<58>-Footnote-1083818666
Ref: Core and Builtins<58>-Footnote-1093818724
Ref: Core and Builtins<58>-Footnote-1103818782
Ref: Core and Builtins<58>-Footnote-1113818840
Ref: Core and Builtins<58>-Footnote-1123818898
Ref: Core and Builtins<58>-Footnote-1133818956
Ref: Core and Builtins<58>-Footnote-1143819014
Ref: Core and Builtins<58>-Footnote-1153819072
Ref: Core and Builtins<58>-Footnote-1163819130
Ref: Core and Builtins<58>-Footnote-1173819188
Ref: Core and Builtins<58>-Footnote-1183819246
Ref: Core and Builtins<58>-Footnote-1193819304
Ref: Core and Builtins<58>-Footnote-1203819362
Ref: Core and Builtins<58>-Footnote-1213819419
Ref: Core and Builtins<58>-Footnote-1223819477
Ref: Core and Builtins<58>-Footnote-1233819535
Ref: Core and Builtins<58>-Footnote-1243819592
Ref: Core and Builtins<58>-Footnote-1253819650
Ref: Core and Builtins<58>-Footnote-1263819708
Ref: Core and Builtins<58>-Footnote-1273819766
Ref: Core and Builtins<58>-Footnote-1283819824
Ref: Core and Builtins<58>-Footnote-1293819882
Ref: Core and Builtins<58>-Footnote-1303819940
Ref: Core and Builtins<58>-Footnote-1313819998
Ref: Core and Builtins<58>-Footnote-1323820056
Ref: Core and Builtins<58>-Footnote-1333820114
Ref: Core and Builtins<58>-Footnote-1343820172
Ref: Core and Builtins<58>-Footnote-1353820230
Ref: Core and Builtins<58>-Footnote-1363820288
Ref: Core and Builtins<58>-Footnote-1373820346
Ref: Core and Builtins<58>-Footnote-1383820404
Ref: Core and Builtins<58>-Footnote-1393820462
Ref: Core and Builtins<58>-Footnote-1403820520
Ref: Core and Builtins<58>-Footnote-1413820578
Ref: Core and Builtins<58>-Footnote-1423820636
Ref: Core and Builtins<58>-Footnote-1433820694
Ref: Core and Builtins<58>-Footnote-1443820752
Ref: Core and Builtins<58>-Footnote-1453820809
Ref: Core and Builtins<58>-Footnote-1463820867
Ref: Core and Builtins<58>-Footnote-1473820925
Ref: Core and Builtins<58>-Footnote-1483820982
Ref: Core and Builtins<58>-Footnote-1493821040
Ref: Core and Builtins<58>-Footnote-1503821098
Ref: Core and Builtins<58>-Footnote-1513821156
Ref: Core and Builtins<58>-Footnote-1523821214
Ref: Core and Builtins<58>-Footnote-1533821272
Ref: Core and Builtins<58>-Footnote-1543821330
Ref: Core and Builtins<58>-Footnote-1553821388
Ref: Core and Builtins<58>-Footnote-1563821446
Ref: Core and Builtins<58>-Footnote-1573821504
Ref: Core and Builtins<58>-Footnote-1583821562
Ref: Core and Builtins<58>-Footnote-1593821620
Ref: Core and Builtins<58>-Footnote-1603821678
Ref: Core and Builtins<58>-Footnote-1613821736
Ref: Core and Builtins<58>-Footnote-1623821794
Ref: Core and Builtins<58>-Footnote-1633821852
Ref: Core and Builtins<58>-Footnote-1643821910
Ref: Core and Builtins<58>-Footnote-1653821968
Ref: Core and Builtins<58>-Footnote-1663822026
Ref: Core and Builtins<58>-Footnote-1673822084
Ref: Core and Builtins<58>-Footnote-1683822141
Ref: Core and Builtins<58>-Footnote-1693822198
Ref: Core and Builtins<58>-Footnote-1703822255
Ref: Core and Builtins<58>-Footnote-1713822313
Node: Library<63>3822370
Ref: whatsnew/changelog id2683822495
Ref: 1a4e3822495
Ref: Library<63>-Footnote-13870895
Ref: Library<63>-Footnote-23870951
Ref: Library<63>-Footnote-33871007
Ref: Library<63>-Footnote-43871063
Ref: Library<63>-Footnote-53871118
Ref: Library<63>-Footnote-63871174
Ref: Library<63>-Footnote-73871230
Ref: Library<63>-Footnote-83871286
Ref: Library<63>-Footnote-93871341
Ref: Library<63>-Footnote-103871397
Ref: Library<63>-Footnote-113871453
Ref: Library<63>-Footnote-123871510
Ref: Library<63>-Footnote-133871567
Ref: Library<63>-Footnote-143871624
Ref: Library<63>-Footnote-153871681
Ref: Library<63>-Footnote-163871738
Ref: Library<63>-Footnote-173871795
Ref: Library<63>-Footnote-183871852
Ref: Library<63>-Footnote-193871909
Ref: Library<63>-Footnote-203871966
Ref: Library<63>-Footnote-213872023
Ref: Library<63>-Footnote-223872080
Ref: Library<63>-Footnote-233872137
Ref: Library<63>-Footnote-243872194
Ref: Library<63>-Footnote-253872237
Ref: Library<63>-Footnote-263872293
Ref: Library<63>-Footnote-273872350
Ref: Library<63>-Footnote-283872407
Ref: Library<63>-Footnote-293872464
Ref: Library<63>-Footnote-303872521
Ref: Library<63>-Footnote-313872578
Ref: Library<63>-Footnote-323872635
Ref: Library<63>-Footnote-333872692
Ref: Library<63>-Footnote-343872749
Ref: Library<63>-Footnote-353872806
Ref: Library<63>-Footnote-363872863
Ref: Library<63>-Footnote-373872920
Ref: Library<63>-Footnote-383872976
Ref: Library<63>-Footnote-393873033
Ref: Library<63>-Footnote-403873090
Ref: Library<63>-Footnote-413873147
Ref: Library<63>-Footnote-423873204
Ref: Library<63>-Footnote-433873261
Ref: Library<63>-Footnote-443873318
Ref: Library<63>-Footnote-453873375
Ref: Library<63>-Footnote-463873432
Ref: Library<63>-Footnote-473873489
Ref: Library<63>-Footnote-483873546
Ref: Library<63>-Footnote-493873603
Ref: Library<63>-Footnote-503873660
Ref: Library<63>-Footnote-513873716
Ref: Library<63>-Footnote-523873773
Ref: Library<63>-Footnote-533873829
Ref: Library<63>-Footnote-543873886
Ref: Library<63>-Footnote-553873943
Ref: Library<63>-Footnote-563874000
Ref: Library<63>-Footnote-573874057
Ref: Library<63>-Footnote-583874114
Ref: Library<63>-Footnote-593874171
Ref: Library<63>-Footnote-603874228
Ref: Library<63>-Footnote-613874285
Ref: Library<63>-Footnote-623874342
Ref: Library<63>-Footnote-633874399
Ref: Library<63>-Footnote-643874456
Ref: Library<63>-Footnote-653874513
Ref: Library<63>-Footnote-663874570
Ref: Library<63>-Footnote-673874627
Ref: Library<63>-Footnote-683874684
Ref: Library<63>-Footnote-693874741
Ref: Library<63>-Footnote-703874797
Ref: Library<63>-Footnote-713874854
Ref: Library<63>-Footnote-723874911
Ref: Library<63>-Footnote-733874968
Ref: Library<63>-Footnote-743875025
Ref: Library<63>-Footnote-753875082
Ref: Library<63>-Footnote-763875138
Ref: Library<63>-Footnote-773875195
Ref: Library<63>-Footnote-783875252
Ref: Library<63>-Footnote-793875309
Ref: Library<63>-Footnote-803875366
Ref: Library<63>-Footnote-813875423
Ref: Library<63>-Footnote-823875480
Ref: Library<63>-Footnote-833875537
Ref: Library<63>-Footnote-843875593
Ref: Library<63>-Footnote-853875649
Ref: Library<63>-Footnote-863875705
Ref: Library<63>-Footnote-873875761
Ref: Library<63>-Footnote-883875818
Ref: Library<63>-Footnote-893875875
Ref: Library<63>-Footnote-903875932
Ref: Library<63>-Footnote-913875989
Ref: Library<63>-Footnote-923876046
Ref: Library<63>-Footnote-933876102
Ref: Library<63>-Footnote-943876159
Ref: Library<63>-Footnote-953876216
Ref: Library<63>-Footnote-963876273
Ref: Library<63>-Footnote-973876329
Ref: Library<63>-Footnote-983876386
Ref: Library<63>-Footnote-993876443
Ref: Library<63>-Footnote-1003876500
Ref: Library<63>-Footnote-1013876558
Ref: Library<63>-Footnote-1023876616
Ref: Library<63>-Footnote-1033876674
Ref: Library<63>-Footnote-1043876732
Ref: Library<63>-Footnote-1053876790
Ref: Library<63>-Footnote-1063876848
Ref: Library<63>-Footnote-1073876906
Ref: Library<63>-Footnote-1083876963
Ref: Library<63>-Footnote-1093877021
Ref: Library<63>-Footnote-1103877078
Ref: Library<63>-Footnote-1113877136
Ref: Library<63>-Footnote-1123877193
Ref: Library<63>-Footnote-1133877250
Ref: Library<63>-Footnote-1143877307
Ref: Library<63>-Footnote-1153877365
Ref: Library<63>-Footnote-1163877423
Ref: Library<63>-Footnote-1173877481
Ref: Library<63>-Footnote-1183877539
Ref: Library<63>-Footnote-1193877597
Ref: Library<63>-Footnote-1203877655
Ref: Library<63>-Footnote-1213877713
Ref: Library<63>-Footnote-1223877771
Ref: Library<63>-Footnote-1233877829
Ref: Library<63>-Footnote-1243877887
Ref: Library<63>-Footnote-1253877945
Ref: Library<63>-Footnote-1263878003
Ref: Library<63>-Footnote-1273878061
Ref: Library<63>-Footnote-1283878119
Ref: Library<63>-Footnote-1293878177
Ref: Library<63>-Footnote-1303878235
Ref: Library<63>-Footnote-1313878293
Ref: Library<63>-Footnote-1323878351
Ref: Library<63>-Footnote-1333878409
Ref: Library<63>-Footnote-1343878467
Ref: Library<63>-Footnote-1353878525
Ref: Library<63>-Footnote-1363878582
Ref: Library<63>-Footnote-1373878640
Ref: Library<63>-Footnote-1383878698
Ref: Library<63>-Footnote-1393878756
Ref: Library<63>-Footnote-1403878814
Ref: Library<63>-Footnote-1413878872
Ref: Library<63>-Footnote-1423878930
Ref: Library<63>-Footnote-1433878988
Ref: Library<63>-Footnote-1443879046
Ref: Library<63>-Footnote-1453879104
Ref: Library<63>-Footnote-1463879162
Ref: Library<63>-Footnote-1473879220
Ref: Library<63>-Footnote-1483879278
Ref: Library<63>-Footnote-1493879336
Ref: Library<63>-Footnote-1503879393
Ref: Library<63>-Footnote-1513879451
Ref: Library<63>-Footnote-1523879508
Ref: Library<63>-Footnote-1533879566
Ref: Library<63>-Footnote-1543879624
Ref: Library<63>-Footnote-1553879682
Ref: Library<63>-Footnote-1563879740
Ref: Library<63>-Footnote-1573879798
Ref: Library<63>-Footnote-1583879856
Ref: Library<63>-Footnote-1593879914
Ref: Library<63>-Footnote-1603879972
Ref: Library<63>-Footnote-1613880030
Ref: Library<63>-Footnote-1623880088
Ref: Library<63>-Footnote-1633880146
Ref: Library<63>-Footnote-1643880204
Ref: Library<63>-Footnote-1653880262
Ref: Library<63>-Footnote-1663880320
Ref: Library<63>-Footnote-1673880377
Ref: Library<63>-Footnote-1683880434
Ref: Library<63>-Footnote-1693880492
Ref: Library<63>-Footnote-1703880550
Ref: Library<63>-Footnote-1713880608
Ref: Library<63>-Footnote-1723880666
Ref: Library<63>-Footnote-1733880710
Ref: Library<63>-Footnote-1743880768
Ref: Library<63>-Footnote-1753880826
Ref: Library<63>-Footnote-1763880884
Ref: Library<63>-Footnote-1773880942
Ref: Library<63>-Footnote-1783881000
Ref: Library<63>-Footnote-1793881058
Ref: Library<63>-Footnote-1803881116
Ref: Library<63>-Footnote-1813881174
Ref: Library<63>-Footnote-1823881232
Ref: Library<63>-Footnote-1833881290
Ref: Library<63>-Footnote-1843881348
Ref: Library<63>-Footnote-1853881406
Ref: Library<63>-Footnote-1863881464
Ref: Library<63>-Footnote-1873881522
Ref: Library<63>-Footnote-1883881580
Ref: Library<63>-Footnote-1893881638
Ref: Library<63>-Footnote-1903881696
Ref: Library<63>-Footnote-1913881754
Ref: Library<63>-Footnote-1923881812
Ref: Library<63>-Footnote-1933881870
Ref: Library<63>-Footnote-1943881928
Ref: Library<63>-Footnote-1953881986
Ref: Library<63>-Footnote-1963882044
Ref: Library<63>-Footnote-1973882102
Ref: Library<63>-Footnote-1983882159
Ref: Library<63>-Footnote-1993882217
Ref: Library<63>-Footnote-2003882275
Ref: Library<63>-Footnote-2013882333
Ref: Library<63>-Footnote-2023882391
Ref: Library<63>-Footnote-2033882449
Ref: Library<63>-Footnote-2043882507
Ref: Library<63>-Footnote-2053882565
Ref: Library<63>-Footnote-2063882622
Ref: Library<63>-Footnote-2073882680
Ref: Library<63>-Footnote-2083882738
Ref: Library<63>-Footnote-2093882796
Ref: Library<63>-Footnote-2103882854
Ref: Library<63>-Footnote-2113882911
Ref: Library<63>-Footnote-2123882969
Ref: Library<63>-Footnote-2133883027
Ref: Library<63>-Footnote-2143883085
Ref: Library<63>-Footnote-2153883143
Ref: Library<63>-Footnote-2163883201
Ref: Library<63>-Footnote-2173883259
Ref: Library<63>-Footnote-2183883317
Ref: Library<63>-Footnote-2193883361
Ref: Library<63>-Footnote-2203883419
Ref: Library<63>-Footnote-2213883463
Ref: Library<63>-Footnote-2223883521
Ref: Library<63>-Footnote-2233883565
Ref: Library<63>-Footnote-2243883623
Ref: Library<63>-Footnote-2253883667
Ref: Library<63>-Footnote-2263883725
Ref: Library<63>-Footnote-2273883769
Ref: Library<63>-Footnote-2283883827
Ref: Library<63>-Footnote-2293883871
Ref: Library<63>-Footnote-2303883929
Ref: Library<63>-Footnote-2313883987
Ref: Library<63>-Footnote-2323884031
Ref: Library<63>-Footnote-2333884089
Ref: Library<63>-Footnote-2343884133
Ref: Library<63>-Footnote-2353884191
Ref: Library<63>-Footnote-2363884249
Ref: Library<63>-Footnote-2373884307
Ref: Library<63>-Footnote-2383884365
Ref: Library<63>-Footnote-2393884409
Ref: Library<63>-Footnote-2403884467
Ref: Library<63>-Footnote-2413884511
Ref: Library<63>-Footnote-2423884558
Ref: Library<63>-Footnote-2433884615
Ref: Library<63>-Footnote-2443884673
Ref: Library<63>-Footnote-2453884717
Ref: Library<63>-Footnote-2463884775
Ref: Library<63>-Footnote-2473884819
Ref: Library<63>-Footnote-2483884877
Ref: Library<63>-Footnote-2493884921
Ref: Library<63>-Footnote-2503884979
Ref: Library<63>-Footnote-2513885023
Ref: Library<63>-Footnote-2523885081
Ref: Library<63>-Footnote-2533885125
Ref: Library<63>-Footnote-2543885183
Ref: Library<63>-Footnote-2553885241
Ref: Library<63>-Footnote-2563885299
Ref: Library<63>-Footnote-2573885357
Ref: Library<63>-Footnote-2583885414
Ref: Library<63>-Footnote-2593885472
Ref: Library<63>-Footnote-2603885516
Ref: Library<63>-Footnote-2613885574
Ref: Library<63>-Footnote-2623885632
Ref: Library<63>-Footnote-2633885690
Ref: Library<63>-Footnote-2643885748
Ref: Library<63>-Footnote-2653885792
Ref: Library<63>-Footnote-2663885850
Ref: Library<63>-Footnote-2673885894
Ref: Library<63>-Footnote-2683885952
Ref: Library<63>-Footnote-2693885996
Ref: Library<63>-Footnote-2703886054
Ref: Library<63>-Footnote-2713886098
Ref: Library<63>-Footnote-2723886156
Ref: Library<63>-Footnote-2733886213
Ref: Library<63>-Footnote-2743886271
Ref: Library<63>-Footnote-2753886329
Ref: Library<63>-Footnote-2763886387
Ref: Library<63>-Footnote-2773886445
Ref: Library<63>-Footnote-2783886503
Ref: Library<63>-Footnote-2793886561
Ref: Library<63>-Footnote-2803886619
Ref: Library<63>-Footnote-2813886677
Ref: Library<63>-Footnote-2823886735
Ref: Library<63>-Footnote-2833886793
Ref: Library<63>-Footnote-2843886850
Ref: Library<63>-Footnote-2853886908
Ref: Library<63>-Footnote-2863886966
Ref: Library<63>-Footnote-2873887024
Ref: Library<63>-Footnote-2883887081
Ref: Library<63>-Footnote-2893887139
Ref: Library<63>-Footnote-2903887196
Ref: Library<63>-Footnote-2913887253
Ref: Library<63>-Footnote-2923887310
Ref: Library<63>-Footnote-2933887367
Ref: Library<63>-Footnote-2943887424
Ref: Library<63>-Footnote-2953887481
Ref: Library<63>-Footnote-2963887538
Ref: Library<63>-Footnote-2973887605
Ref: Library<63>-Footnote-2983887666
Ref: Library<63>-Footnote-2993887733
Ref: Library<63>-Footnote-3003887777
Ref: Library<63>-Footnote-3013887844
Ref: Library<63>-Footnote-3023887911
Ref: Library<63>-Footnote-3033887978
Ref: Library<63>-Footnote-3043888045
Node: Documentation<19>3888112
Ref: whatsnew/changelog id2693888225
Ref: 1a623888225
Ref: Documentation<19>-Footnote-13890177
Ref: Documentation<19>-Footnote-23890233
Ref: Documentation<19>-Footnote-33890289
Ref: Documentation<19>-Footnote-43890345
Ref: Documentation<19>-Footnote-53890401
Ref: Documentation<19>-Footnote-63890457
Ref: Documentation<19>-Footnote-73890513
Ref: Documentation<19>-Footnote-83890569
Ref: Documentation<19>-Footnote-93890625
Ref: Documentation<19>-Footnote-103890680
Ref: Documentation<19>-Footnote-113890736
Ref: Documentation<19>-Footnote-123890793
Ref: Documentation<19>-Footnote-133890849
Ref: Documentation<19>-Footnote-143890906
Node: Tests<19>3890963
Ref: whatsnew/changelog id2703891074
Ref: 1a633891074
Ref: Tests<19>-Footnote-13904233
Ref: Tests<19>-Footnote-23904289
Ref: Tests<19>-Footnote-33904345
Ref: Tests<19>-Footnote-43904401
Ref: Tests<19>-Footnote-53904457
Ref: Tests<19>-Footnote-63904512
Ref: Tests<19>-Footnote-73904568
Ref: Tests<19>-Footnote-83904624
Ref: Tests<19>-Footnote-93904680
Ref: Tests<19>-Footnote-103904736
Ref: Tests<19>-Footnote-113904793
Ref: Tests<19>-Footnote-123904850
Ref: Tests<19>-Footnote-133904907
Ref: Tests<19>-Footnote-143904964
Ref: Tests<19>-Footnote-153905021
Ref: Tests<19>-Footnote-163905078
Ref: Tests<19>-Footnote-173905135
Ref: Tests<19>-Footnote-183905192
Ref: Tests<19>-Footnote-193905249
Ref: Tests<19>-Footnote-203905306
Ref: Tests<19>-Footnote-213905363
Ref: Tests<19>-Footnote-223905420
Ref: Tests<19>-Footnote-233905477
Ref: Tests<19>-Footnote-243905534
Ref: Tests<19>-Footnote-253905591
Ref: Tests<19>-Footnote-263905648
Ref: Tests<19>-Footnote-273905705
Ref: Tests<19>-Footnote-283905762
Ref: Tests<19>-Footnote-293905819
Ref: Tests<19>-Footnote-303905876
Ref: Tests<19>-Footnote-313905933
Ref: Tests<19>-Footnote-323905990
Ref: Tests<19>-Footnote-333906047
Ref: Tests<19>-Footnote-343906091
Ref: Tests<19>-Footnote-353906147
Ref: Tests<19>-Footnote-363906204
Ref: Tests<19>-Footnote-373906260
Ref: Tests<19>-Footnote-383906316
Ref: Tests<19>-Footnote-393906373
Ref: Tests<19>-Footnote-403906430
Ref: Tests<19>-Footnote-413906487
Ref: Tests<19>-Footnote-423906544
Ref: Tests<19>-Footnote-433906601
Ref: Tests<19>-Footnote-443906658
Ref: Tests<19>-Footnote-453906715
Ref: Tests<19>-Footnote-463906772
Ref: Tests<19>-Footnote-473906829
Ref: Tests<19>-Footnote-483906886
Ref: Tests<19>-Footnote-493906943
Ref: Tests<19>-Footnote-503907000
Ref: Tests<19>-Footnote-513907057
Ref: Tests<19>-Footnote-523907114
Ref: Tests<19>-Footnote-533907171
Ref: Tests<19>-Footnote-543907228
Ref: Tests<19>-Footnote-553907285
Ref: Tests<19>-Footnote-563907342
Ref: Tests<19>-Footnote-573907399
Ref: Tests<19>-Footnote-583907455
Ref: Tests<19>-Footnote-593907512
Node: Build<22>3907568
Ref: whatsnew/changelog id2713907673
Ref: 1a653907673
Ref: Build<22>-Footnote-13911669
Ref: Build<22>-Footnote-23911725
Ref: Build<22>-Footnote-33911781
Ref: Build<22>-Footnote-43911837
Ref: Build<22>-Footnote-53911893
Ref: Build<22>-Footnote-63911949
Ref: Build<22>-Footnote-73912005
Ref: Build<22>-Footnote-83912060
Ref: Build<22>-Footnote-93912116
Ref: Build<22>-Footnote-103912172
Ref: Build<22>-Footnote-113912228
Ref: Build<22>-Footnote-123912285
Ref: Build<22>-Footnote-133912342
Ref: Build<22>-Footnote-143912399
Ref: Build<22>-Footnote-153912456
Ref: Build<22>-Footnote-163912512
Ref: Build<22>-Footnote-173912569
Ref: Build<22>-Footnote-183912626
Ref: Build<22>-Footnote-193912683
Ref: Build<22>-Footnote-203912740
Ref: Build<22>-Footnote-213912796
Ref: Build<22>-Footnote-223912853
Ref: Build<22>-Footnote-233912909
Ref: Build<22>-Footnote-243912966
Node: Windows<20>3913023
Ref: whatsnew/changelog id2723913128
Ref: 1a673913128
Ref: Windows<20>-Footnote-13915635
Ref: Windows<20>-Footnote-23915691
Ref: Windows<20>-Footnote-33915747
Ref: Windows<20>-Footnote-43915802
Ref: Windows<20>-Footnote-53915858
Ref: Windows<20>-Footnote-63915914
Ref: Windows<20>-Footnote-73915969
Ref: Windows<20>-Footnote-83916025
Ref: Windows<20>-Footnote-93916081
Ref: Windows<20>-Footnote-103916137
Ref: Windows<20>-Footnote-113916194
Ref: Windows<20>-Footnote-123916250
Ref: Windows<20>-Footnote-133916307
Node: macOS<13>3916364
Ref: whatsnew/changelog id2733916468
Ref: 1a683916468
Ref: macOS<13>-Footnote-13916732
Ref: macOS<13>-Footnote-23916788
Ref: macOS<13>-Footnote-33916844
Node: IDLE<13>3916899
Ref: whatsnew/changelog id2743917007
Ref: 1a693917007
Ref: IDLE<13>-Footnote-13917198
Node: Tools/Demos<19>3917254
Ref: whatsnew/changelog id2753917362
Ref: 1a6a3917362
Ref: Tools/Demos<19>-Footnote-13919883
Ref: Tools/Demos<19>-Footnote-23919939
Ref: Tools/Demos<19>-Footnote-33919995
Ref: Tools/Demos<19>-Footnote-43920057
Ref: Tools/Demos<19>-Footnote-53920146
Ref: Tools/Demos<19>-Footnote-63920202
Ref: Tools/Demos<19>-Footnote-73920296
Ref: Tools/Demos<19>-Footnote-83920352
Ref: Tools/Demos<19>-Footnote-93920408
Ref: Tools/Demos<19>-Footnote-103920463
Ref: Tools/Demos<19>-Footnote-113920559
Ref: Tools/Demos<19>-Footnote-123920616
Ref: Tools/Demos<19>-Footnote-133920673
Ref: Tools/Demos<19>-Footnote-143920730
Ref: Tools/Demos<19>-Footnote-153920787
Ref: Tools/Demos<19>-Footnote-163920844
Ref: Tools/Demos<19>-Footnote-173920901
Ref: Tools/Demos<19>-Footnote-183920957
Node: C API<22>3921055
Ref: whatsnew/changelog id2763921146
Ref: 1a6b3921146
Ref: C API<22>-Footnote-13936079
Ref: C API<22>-Footnote-23936134
Ref: C API<22>-Footnote-33936190
Ref: C API<22>-Footnote-43936246
Ref: C API<22>-Footnote-53936302
Ref: C API<22>-Footnote-63936358
Ref: C API<22>-Footnote-73936414
Ref: C API<22>-Footnote-83936469
Ref: C API<22>-Footnote-93936525
Ref: C API<22>-Footnote-103936581
Ref: C API<22>-Footnote-113936638
Ref: C API<22>-Footnote-123936695
Ref: C API<22>-Footnote-133936752
Ref: C API<22>-Footnote-143936809
Ref: C API<22>-Footnote-153936866
Ref: C API<22>-Footnote-163936923
Ref: C API<22>-Footnote-173936980
Ref: C API<22>-Footnote-183937037
Ref: C API<22>-Footnote-193937094
Ref: C API<22>-Footnote-203937151
Ref: C API<22>-Footnote-213937208
Ref: C API<22>-Footnote-223937265
Ref: C API<22>-Footnote-233937322
Ref: C API<22>-Footnote-243937379
Ref: C API<22>-Footnote-253937436
Ref: C API<22>-Footnote-263937493
Ref: C API<22>-Footnote-273937550
Ref: C API<22>-Footnote-283937607
Ref: C API<22>-Footnote-293937664
Ref: C API<22>-Footnote-303937721
Ref: C API<22>-Footnote-313937778
Ref: C API<22>-Footnote-323937835
Ref: C API<22>-Footnote-333937878
Ref: C API<22>-Footnote-343937935
Ref: C API<22>-Footnote-353937992
Ref: C API<22>-Footnote-363938049
Ref: C API<22>-Footnote-373938106
Ref: C API<22>-Footnote-383938163
Ref: C API<22>-Footnote-393938220
Ref: C API<22>-Footnote-403938277
Ref: C API<22>-Footnote-413938334
Ref: C API<22>-Footnote-423938391
Ref: C API<22>-Footnote-433938448
Ref: C API<22>-Footnote-443938505
Ref: C API<22>-Footnote-453938562
Ref: C API<22>-Footnote-463938619
Ref: C API<22>-Footnote-473938676
Ref: C API<22>-Footnote-483938733
Ref: C API<22>-Footnote-493938790
Ref: C API<22>-Footnote-503938846
Ref: C API<22>-Footnote-513938903
Ref: C API<22>-Footnote-523938960
Ref: C API<22>-Footnote-533939017
Ref: C API<22>-Footnote-543939074
Ref: C API<22>-Footnote-553939131
Ref: C API<22>-Footnote-563939188
Ref: C API<22>-Footnote-573939245
Ref: C API<22>-Footnote-583939302
Ref: C API<22>-Footnote-593939368
Node: Python 3 12 0 beta 13939434
Ref: whatsnew/changelog python-3-12-0-beta-13939560
Ref: 1a763939560
Node: Security<22>3940033
Ref: whatsnew/changelog id2773940122
Ref: 1a773940122
Ref: Security<22>-Footnote-13940941
Ref: Security<22>-Footnote-23940996
Ref: Security<22>-Footnote-33941052
Ref: Security<22>-Footnote-43941107
Ref: Security<22>-Footnote-53941163
Node: Library<64>3941219
Ref: whatsnew/changelog id2783941338
Ref: 1a783941338
Ref: Library<64>-Footnote-13941555
Node: Core and Builtins<59>3941611
Ref: whatsnew/changelog id2793941729
Ref: 1a793941729
Ref: Core and Builtins<59>-Footnote-13948153
Ref: Core and Builtins<59>-Footnote-23948209
Ref: Core and Builtins<59>-Footnote-33948265
Ref: Core and Builtins<59>-Footnote-43948307
Ref: Core and Builtins<59>-Footnote-53948363
Ref: Core and Builtins<59>-Footnote-63948419
Ref: Core and Builtins<59>-Footnote-73948475
Ref: Core and Builtins<59>-Footnote-83948517
Ref: Core and Builtins<59>-Footnote-93948573
Ref: Core and Builtins<59>-Footnote-103948629
Ref: Core and Builtins<59>-Footnote-113948685
Ref: Core and Builtins<59>-Footnote-123948741
Ref: Core and Builtins<59>-Footnote-133948798
Ref: Core and Builtins<59>-Footnote-143948855
Ref: Core and Builtins<59>-Footnote-153948898
Ref: Core and Builtins<59>-Footnote-163948955
Ref: Core and Builtins<59>-Footnote-173949012
Ref: Core and Builtins<59>-Footnote-183949069
Ref: Core and Builtins<59>-Footnote-193949126
Ref: Core and Builtins<59>-Footnote-203949183
Ref: Core and Builtins<59>-Footnote-213949240
Ref: Core and Builtins<59>-Footnote-223949297
Ref: Core and Builtins<59>-Footnote-233949354
Ref: Core and Builtins<59>-Footnote-243949411
Ref: Core and Builtins<59>-Footnote-253949468
Node: Library<65>3949511
Ref: whatsnew/changelog id2803949639
Ref: 1a7a3949639
Ref: Library<65>-Footnote-13950062
Ref: Library<65>-Footnote-23950118
Node: Core and Builtins<60>3950174
Ref: whatsnew/changelog id2813950292
Ref: 1a7b3950292
Ref: Core and Builtins<60>-Footnote-13954340
Ref: Core and Builtins<60>-Footnote-23954396
Ref: Core and Builtins<60>-Footnote-33954452
Ref: Core and Builtins<60>-Footnote-43954508
Ref: Core and Builtins<60>-Footnote-53954564
Ref: Core and Builtins<60>-Footnote-63954620
Ref: Core and Builtins<60>-Footnote-73954676
Ref: Core and Builtins<60>-Footnote-83954732
Ref: Core and Builtins<60>-Footnote-93954787
Ref: Core and Builtins<60>-Footnote-103954843
Ref: Core and Builtins<60>-Footnote-113954899
Ref: Core and Builtins<60>-Footnote-123954955
Ref: Core and Builtins<60>-Footnote-133954998
Ref: Core and Builtins<60>-Footnote-143955055
Ref: Core and Builtins<60>-Footnote-153955112
Ref: Core and Builtins<60>-Footnote-163955169
Ref: Core and Builtins<60>-Footnote-173955225
Ref: Core and Builtins<60>-Footnote-183955282
Ref: Core and Builtins<60>-Footnote-193955339
Ref: Core and Builtins<60>-Footnote-203955382
Ref: Core and Builtins<60>-Footnote-213955438
Ref: Core and Builtins<60>-Footnote-223955495
Ref: Core and Builtins<60>-Footnote-233955538
Ref: Core and Builtins<60>-Footnote-243955594
Ref: Core and Builtins<60>-Footnote-253955637
Ref: Core and Builtins<60>-Footnote-263955693
Ref: Core and Builtins<60>-Footnote-273955749
Node: Library<66>3955815
Ref: whatsnew/changelog id2823955939
Ref: 1a7c3955939
Ref: Library<66>-Footnote-13979570
Ref: Library<66>-Footnote-23979635
Ref: Library<66>-Footnote-33979691
Ref: Library<66>-Footnote-43979733
Ref: Library<66>-Footnote-53979789
Ref: Library<66>-Footnote-63979845
Ref: Library<66>-Footnote-73979901
Ref: Library<66>-Footnote-83979957
Ref: Library<66>-Footnote-93980012
Ref: Library<66>-Footnote-103980068
Ref: Library<66>-Footnote-113980125
Ref: Library<66>-Footnote-123980182
Ref: Library<66>-Footnote-133980239
Ref: Library<66>-Footnote-143980296
Ref: Library<66>-Footnote-153980353
Ref: Library<66>-Footnote-163980410
Ref: Library<66>-Footnote-173980467
Ref: Library<66>-Footnote-183980543
Ref: Library<66>-Footnote-193980600
Ref: Library<66>-Footnote-203980657
Ref: Library<66>-Footnote-213980713
Ref: Library<66>-Footnote-223980770
Ref: Library<66>-Footnote-233980836
Ref: Library<66>-Footnote-243980893
Ref: Library<66>-Footnote-253980949
Ref: Library<66>-Footnote-263981005
Ref: Library<66>-Footnote-273981062
Ref: Library<66>-Footnote-283981119
Ref: Library<66>-Footnote-293981176
Ref: Library<66>-Footnote-303981233
Ref: Library<66>-Footnote-313981290
Ref: Library<66>-Footnote-323981347
Ref: Library<66>-Footnote-333981404
Ref: Library<66>-Footnote-343981447
Ref: Library<66>-Footnote-353981504
Ref: Library<66>-Footnote-363981561
Ref: Library<66>-Footnote-373981618
Ref: Library<66>-Footnote-383981675
Ref: Library<66>-Footnote-393981731
Ref: Library<66>-Footnote-403981788
Ref: Library<66>-Footnote-413981844
Ref: Library<66>-Footnote-423981901
Ref: Library<66>-Footnote-433981958
Ref: Library<66>-Footnote-443982015
Ref: Library<66>-Footnote-453982072
Ref: Library<66>-Footnote-463982129
Ref: Library<66>-Footnote-473982186
Ref: Library<66>-Footnote-483982242
Ref: Library<66>-Footnote-493982298
Ref: Library<66>-Footnote-503982355
Ref: Library<66>-Footnote-513982412
Ref: Library<66>-Footnote-523982469
Ref: Library<66>-Footnote-533982526
Ref: Library<66>-Footnote-543982582
Ref: Library<66>-Footnote-553982639
Ref: Library<66>-Footnote-563982695
Ref: Library<66>-Footnote-573982752
Ref: Library<66>-Footnote-583982809
Ref: Library<66>-Footnote-593982865
Ref: Library<66>-Footnote-603982921
Ref: Library<66>-Footnote-613982978
Ref: Library<66>-Footnote-623983035
Ref: Library<66>-Footnote-633983091
Ref: Library<66>-Footnote-643983148
Ref: Library<66>-Footnote-653983205
Ref: Library<66>-Footnote-663983262
Ref: Library<66>-Footnote-673983319
Ref: Library<66>-Footnote-683983376
Ref: Library<66>-Footnote-693983433
Ref: Library<66>-Footnote-703983490
Ref: Library<66>-Footnote-713983547
Ref: Library<66>-Footnote-723983604
Ref: Library<66>-Footnote-733983661
Ref: Library<66>-Footnote-743983718
Ref: Library<66>-Footnote-753983775
Ref: Library<66>-Footnote-763983832
Ref: Library<66>-Footnote-773983889
Ref: Library<66>-Footnote-783983946
Ref: Library<66>-Footnote-793983989
Ref: Library<66>-Footnote-803984046
Ref: Library<66>-Footnote-813984103
Ref: Library<66>-Footnote-823984146
Ref: Library<66>-Footnote-833984202
Ref: Library<66>-Footnote-843984258
Ref: Library<66>-Footnote-853984315
Ref: Library<66>-Footnote-863984372
Ref: Library<66>-Footnote-873984429
Ref: Library<66>-Footnote-883984486
Ref: Library<66>-Footnote-893984543
Ref: Library<66>-Footnote-903984586
Ref: Library<66>-Footnote-913984643
Ref: Library<66>-Footnote-923984686
Ref: Library<66>-Footnote-933984742
Ref: Library<66>-Footnote-943984799
Ref: Library<66>-Footnote-953984856
Ref: Library<66>-Footnote-963984899
Ref: Library<66>-Footnote-973984956
Ref: Library<66>-Footnote-983985013
Ref: Library<66>-Footnote-993985070
Ref: Library<66>-Footnote-1003985126
Ref: Library<66>-Footnote-1013985184
Ref: Library<66>-Footnote-1023985242
Ref: Library<66>-Footnote-1033985300
Ref: Library<66>-Footnote-1043985358
Ref: Library<66>-Footnote-1053985416
Ref: Library<66>-Footnote-1063985474
Ref: Library<66>-Footnote-1073985531
Ref: Library<66>-Footnote-1083985588
Ref: Library<66>-Footnote-1093985646
Ref: Library<66>-Footnote-1103985690
Ref: Library<66>-Footnote-1113985747
Ref: Library<66>-Footnote-1123985805
Ref: Library<66>-Footnote-1133985863
Ref: Library<66>-Footnote-1143985920
Ref: Library<66>-Footnote-1153985977
Ref: Library<66>-Footnote-1163986034
Ref: Library<66>-Footnote-1173986092
Ref: Library<66>-Footnote-1183986150
Ref: Library<66>-Footnote-1193986207
Ref: Library<66>-Footnote-1203986264
Ref: Library<66>-Footnote-1213986321
Ref: Library<66>-Footnote-1223986378
Ref: Library<66>-Footnote-1233986435
Ref: Library<66>-Footnote-1243986492
Ref: Library<66>-Footnote-1253986549
Ref: Library<66>-Footnote-1263986606
Ref: Library<66>-Footnote-1273986663
Ref: Library<66>-Footnote-1283986720
Ref: Library<66>-Footnote-1293986777
Ref: Library<66>-Footnote-1303986834
Ref: Library<66>-Footnote-1313986891
Ref: Library<66>-Footnote-1323986948
Ref: Library<66>-Footnote-1333987005
Ref: Library<66>-Footnote-1343987072
Ref: Library<66>-Footnote-1353987139
Ref: Library<66>-Footnote-1363987206
Ref: Library<66>-Footnote-1373987273
Ref: Library<66>-Footnote-1383987340
Ref: Library<66>-Footnote-1393987407
Ref: Library<66>-Footnote-1403987474
Node: Documentation<20>3987541
Ref: whatsnew/changelog id2833987653
Ref: 1a883987653
Ref: Documentation<20>-Footnote-13988426
Ref: Documentation<20>-Footnote-23988481
Ref: Documentation<20>-Footnote-33988537
Ref: Documentation<20>-Footnote-43988579
Ref: Documentation<20>-Footnote-53988634
Ref: Documentation<20>-Footnote-63988689
Node: Tests<20>3988744
Ref: whatsnew/changelog id2843988854
Ref: 1a893988854
Ref: Tests<20>-Footnote-13989763
Ref: Tests<20>-Footnote-23989819
Ref: Tests<20>-Footnote-33989875
Ref: Tests<20>-Footnote-43989930
Ref: Tests<20>-Footnote-53989986
Ref: Tests<20>-Footnote-63990042
Node: Build<23>3990097
Ref: whatsnew/changelog id2853990201
Ref: 1a8a3990201
Ref: Build<23>-Footnote-13991785
Ref: Build<23>-Footnote-23991841
Ref: Build<23>-Footnote-33991896
Ref: Build<23>-Footnote-43991952
Ref: Build<23>-Footnote-53992008
Ref: Build<23>-Footnote-63992064
Ref: Build<23>-Footnote-73992119
Ref: Build<23>-Footnote-83992174
Ref: Build<23>-Footnote-93992230
Node: Windows<21>3992285
Ref: whatsnew/changelog id2863992389
Ref: 1a8b3992389
Ref: Windows<21>-Footnote-13993244
Ref: Windows<21>-Footnote-23993300
Ref: Windows<21>-Footnote-33993355
Ref: Windows<21>-Footnote-43993411
Ref: Windows<21>-Footnote-53993467
Ref: Windows<21>-Footnote-63993523
Node: macOS<14>3993578
Ref: whatsnew/changelog id2873993681
Ref: 1a8c3993681
Ref: macOS<14>-Footnote-13994485
Ref: macOS<14>-Footnote-23994540
Ref: macOS<14>-Footnote-33994596
Ref: macOS<14>-Footnote-43994652
Ref: macOS<14>-Footnote-53994708
Ref: macOS<14>-Footnote-63994763
Node: IDLE<14>3994819
Ref: whatsnew/changelog id2883994926
Ref: 1a8d3994926
Ref: IDLE<14>-Footnote-13995210
Ref: IDLE<14>-Footnote-23995266
Ref: IDLE<14>-Footnote-33995322
Node: Tools/Demos<20>3995377
Ref: whatsnew/changelog id2893995484
Ref: 1a8e3995484
Ref: Tools/Demos<20>-Footnote-13995744
Node: C API<23>3995800
Ref: whatsnew/changelog id2903995890
Ref: 1a8f3995890
Ref: C API<23>-Footnote-13998872
Ref: C API<23>-Footnote-23998928
Ref: C API<23>-Footnote-33998984
Ref: C API<23>-Footnote-43999040
Ref: C API<23>-Footnote-53999096
Ref: C API<23>-Footnote-63999152
Ref: C API<23>-Footnote-73999208
Ref: C API<23>-Footnote-83999250
Ref: C API<23>-Footnote-93999306
Ref: C API<23>-Footnote-103999362
Ref: C API<23>-Footnote-113999418
Node: Python 3 12 0 alpha 73999474
Ref: whatsnew/changelog python-3-12-0-alpha-73999600
Ref: 1a963999600
Node: Core and Builtins<61>4000051
Ref: whatsnew/changelog id2914000150
Ref: 1a974000150
Ref: Core and Builtins<61>-Footnote-14001478
Ref: Core and Builtins<61>-Footnote-24001534
Ref: Core and Builtins<61>-Footnote-34001589
Ref: Core and Builtins<61>-Footnote-44001645
Ref: Core and Builtins<61>-Footnote-54001701
Ref: Core and Builtins<61>-Footnote-64001757
Ref: Core and Builtins<61>-Footnote-74001813
Ref: Core and Builtins<61>-Footnote-84001869
Ref: Core and Builtins<61>-Footnote-94001925
Ref: Core and Builtins<61>-Footnote-104001981
Node: Library<67>4002037
Ref: whatsnew/changelog id2924002166
Ref: 1a984002166
Ref: Library<67>-Footnote-14002473
Node: Core and Builtins<62>4002529
Ref: whatsnew/changelog id2934002646
Ref: 1a994002646
Ref: Core and Builtins<62>-Footnote-14003968
Ref: Core and Builtins<62>-Footnote-24004024
Ref: Core and Builtins<62>-Footnote-34004080
Ref: Core and Builtins<62>-Footnote-44004136
Ref: Core and Builtins<62>-Footnote-54004178
Ref: Core and Builtins<62>-Footnote-64004234
Ref: Core and Builtins<62>-Footnote-74004290
Ref: Core and Builtins<62>-Footnote-84004346
Node: Build<24>4004402
Ref: whatsnew/changelog id2944004529
Ref: 1a9a4004529
Ref: Build<24>-Footnote-14004709
Node: Core and Builtins<63>4004765
Ref: whatsnew/changelog id2954004882
Ref: 1a9b4004882
Ref: Core and Builtins<63>-Footnote-14005082
Node: Library<68>4005138
Ref: whatsnew/changelog id2964005263
Ref: 1a9c4005263
Ref: Library<68>-Footnote-14013202
Ref: Library<68>-Footnote-24013269
Ref: Library<68>-Footnote-34013311
Ref: Library<68>-Footnote-44013367
Ref: Library<68>-Footnote-54013423
Ref: Library<68>-Footnote-64013479
Ref: Library<68>-Footnote-74013535
Ref: Library<68>-Footnote-84013591
Ref: Library<68>-Footnote-94013647
Ref: Library<68>-Footnote-104013703
Ref: Library<68>-Footnote-114013760
Ref: Library<68>-Footnote-124013817
Ref: Library<68>-Footnote-134013874
Ref: Library<68>-Footnote-144013931
Ref: Library<68>-Footnote-154013988
Ref: Library<68>-Footnote-164014044
Ref: Library<68>-Footnote-174014100
Ref: Library<68>-Footnote-184014156
Ref: Library<68>-Footnote-194014213
Ref: Library<68>-Footnote-204014270
Ref: Library<68>-Footnote-214014327
Ref: Library<68>-Footnote-224014384
Ref: Library<68>-Footnote-234014441
Ref: Library<68>-Footnote-244014498
Ref: Library<68>-Footnote-254014554
Ref: Library<68>-Footnote-264014611
Ref: Library<68>-Footnote-274014667
Ref: Library<68>-Footnote-284014724
Ref: Library<68>-Footnote-294014781
Ref: Library<68>-Footnote-304014838
Ref: Library<68>-Footnote-314014894
Ref: Library<68>-Footnote-324014951
Ref: Library<68>-Footnote-334015008
Ref: Library<68>-Footnote-344015065
Ref: Library<68>-Footnote-354015121
Ref: Library<68>-Footnote-364015178
Ref: Library<68>-Footnote-374015234
Ref: Library<68>-Footnote-384015290
Ref: Library<68>-Footnote-394015346
Ref: Library<68>-Footnote-404015402
Ref: Library<68>-Footnote-414015458
Ref: Library<68>-Footnote-424015514
Ref: Library<68>-Footnote-434015570
Node: Documentation<21>4015636
Ref: whatsnew/changelog id2974015749
Ref: 1aa14015749
Ref: Documentation<21>-Footnote-14015948
Node: Tests<21>4016004
Ref: whatsnew/changelog id2984016115
Ref: 1aa24016115
Ref: Tests<21>-Footnote-14016472
Ref: Tests<21>-Footnote-24016528
Ref: Tests<21>-Footnote-34016584
Node: Build<25>4016640
Ref: whatsnew/changelog id2994016745
Ref: 1aa34016745
Ref: Build<25>-Footnote-14016991
Ref: Build<25>-Footnote-24017047
Node: Windows<22>4017103
Ref: whatsnew/changelog id3004017214
Ref: 1aa44017214
Ref: Windows<22>-Footnote-14017514
Ref: Windows<22>-Footnote-24017570
Node: Tools/Demos<21>4017625
Ref: whatsnew/changelog id3014017736
Ref: 1aa54017736
Ref: Tools/Demos<21>-Footnote-14017871
Node: C API<24>4017927
Ref: whatsnew/changelog id3024018018
Ref: 1aa64018018
Ref: C API<24>-Footnote-14018236
Node: Python 3 12 0 alpha 64018292
Ref: whatsnew/changelog python-3-12-0-alpha-64018419
Ref: 1aa74018419
Node: Security<23>4018752
Ref: whatsnew/changelog id3034018852
Ref: 1aa84018852
Ref: Security<23>-Footnote-14019790
Ref: Security<23>-Footnote-24019845
Ref: Security<23>-Footnote-34019901
Ref: Security<23>-Footnote-44019956
Ref: Security<23>-Footnote-54020011
Ref: Security<23>-Footnote-64020066
Ref: Security<23>-Footnote-74020127
Ref: Security<23>-Footnote-84020182
Ref: Security<23>-Footnote-94020230
Node: Core and Builtins<64>4020286
Ref: whatsnew/changelog id3044020406
Ref: 1aa94020406
Ref: Core and Builtins<64>-Footnote-14024039
Ref: Core and Builtins<64>-Footnote-24024095
Ref: Core and Builtins<64>-Footnote-34024151
Ref: Core and Builtins<64>-Footnote-44024207
Ref: Core and Builtins<64>-Footnote-54024263
Ref: Core and Builtins<64>-Footnote-64024319
Ref: Core and Builtins<64>-Footnote-74024375
Ref: Core and Builtins<64>-Footnote-84024431
Ref: Core and Builtins<64>-Footnote-94024487
Ref: Core and Builtins<64>-Footnote-104024543
Ref: Core and Builtins<64>-Footnote-114024600
Ref: Core and Builtins<64>-Footnote-124024657
Ref: Core and Builtins<64>-Footnote-134024713
Ref: Core and Builtins<64>-Footnote-144024770
Ref: Core and Builtins<64>-Footnote-154024827
Ref: Core and Builtins<64>-Footnote-164024883
Ref: Core and Builtins<64>-Footnote-174024939
Ref: Core and Builtins<64>-Footnote-184024996
Ref: Core and Builtins<64>-Footnote-194025053
Ref: Core and Builtins<64>-Footnote-204025110
Ref: Core and Builtins<64>-Footnote-214025167
Ref: Core and Builtins<64>-Footnote-224025224
Node: Library<69>4025280
Ref: whatsnew/changelog id3054025405
Ref: 1aad4025405
Ref: Library<69>-Footnote-14031246
Ref: Library<69>-Footnote-24031302
Ref: Library<69>-Footnote-34031358
Ref: Library<69>-Footnote-44031413
Ref: Library<69>-Footnote-54031468
Ref: Library<69>-Footnote-64031524
Ref: Library<69>-Footnote-74031580
Ref: Library<69>-Footnote-84031636
Ref: Library<69>-Footnote-94031692
Ref: Library<69>-Footnote-104031759
Ref: Library<69>-Footnote-114031815
Ref: Library<69>-Footnote-124031899
Ref: Library<69>-Footnote-134031956
Ref: Library<69>-Footnote-144032012
Ref: Library<69>-Footnote-154032069
Ref: Library<69>-Footnote-164032125
Ref: Library<69>-Footnote-174032181
Ref: Library<69>-Footnote-184032238
Ref: Library<69>-Footnote-194032295
Ref: Library<69>-Footnote-204032352
Ref: Library<69>-Footnote-214032409
Ref: Library<69>-Footnote-224032466
Ref: Library<69>-Footnote-234032523
Ref: Library<69>-Footnote-244032580
Ref: Library<69>-Footnote-254032636
Ref: Library<69>-Footnote-264032693
Ref: Library<69>-Footnote-274032736
Ref: Library<69>-Footnote-284032792
Ref: Library<69>-Footnote-294032849
Ref: Library<69>-Footnote-304032906
Ref: Library<69>-Footnote-314032949
Ref: Library<69>-Footnote-324033006
Ref: Library<69>-Footnote-334033062
Ref: Library<69>-Footnote-344033105
Ref: Library<69>-Footnote-354033161
Ref: Library<69>-Footnote-364033217
Node: Documentation<22>4033283
Ref: whatsnew/changelog id3064033396
Ref: 1ab74033396
Ref: Documentation<22>-Footnote-14033705
Ref: Documentation<22>-Footnote-24033760
Node: Tests<22>4033815
Ref: whatsnew/changelog id3074033926
Ref: 1ab94033926
Ref: Tests<22>-Footnote-14034500
Ref: Tests<22>-Footnote-24034556
Ref: Tests<22>-Footnote-34034611
Node: Build<26>4034666
Ref: whatsnew/changelog id3084034771
Ref: 1aba4034771
Ref: Build<26>-Footnote-14035450
Ref: Build<26>-Footnote-24035505
Ref: Build<26>-Footnote-34035560
Ref: Build<26>-Footnote-44035616
Node: Windows<23>4035671
Ref: whatsnew/changelog id3094035776
Ref: 1abc4035776
Ref: Windows<23>-Footnote-14036795
Ref: Windows<23>-Footnote-24036851
Ref: Windows<23>-Footnote-34036907
Ref: Windows<23>-Footnote-44036963
Ref: Windows<23>-Footnote-54037019
Ref: Windows<23>-Footnote-64037075
Ref: Windows<23>-Footnote-74037131
Ref: Windows<23>-Footnote-84037187
Node: macOS<15>4037243
Ref: whatsnew/changelog id3104037348
Ref: 1abd4037348
Ref: macOS<15>-Footnote-14037478
Node: C API<25>4037534
Ref: whatsnew/changelog id3114037619
Ref: 1abe4037619
Ref: C API<25>-Footnote-14038716
Ref: C API<25>-Footnote-24038772
Ref: C API<25>-Footnote-34038827
Ref: C API<25>-Footnote-44038883
Ref: C API<25>-Footnote-54038938
Node: Python 3 12 0 alpha 54038980
Ref: whatsnew/changelog python-3-12-0-alpha-54039107
Ref: 1abf4039107
Node: Security<24>4039400
Ref: whatsnew/changelog id3124039500
Ref: 1ac04039500
Ref: Security<24>-Footnote-14039878
Ref: Security<24>-Footnote-24039933
Node: Core and Builtins<65>4039981
Ref: whatsnew/changelog id3144040101
Ref: 1ac14040101
Ref: Core and Builtins<65>-Footnote-14043000
Ref: Core and Builtins<65>-Footnote-24043055
Ref: Core and Builtins<65>-Footnote-34043110
Ref: Core and Builtins<65>-Footnote-44043166
Ref: Core and Builtins<65>-Footnote-54043222
Ref: Core and Builtins<65>-Footnote-64043278
Ref: Core and Builtins<65>-Footnote-74043334
Ref: Core and Builtins<65>-Footnote-84043390
Ref: Core and Builtins<65>-Footnote-94043446
Ref: Core and Builtins<65>-Footnote-104043502
Ref: Core and Builtins<65>-Footnote-114043559
Ref: Core and Builtins<65>-Footnote-124043616
Ref: Core and Builtins<65>-Footnote-134043673
Ref: Core and Builtins<65>-Footnote-144043730
Ref: Core and Builtins<65>-Footnote-154043786
Ref: Core and Builtins<65>-Footnote-164043843
Node: Library<70>4043900
Ref: whatsnew/changelog id3154044025
Ref: 1ac44044025
Ref: Library<70>-Footnote-14049285
Ref: Library<70>-Footnote-24049350
Ref: Library<70>-Footnote-34049406
Ref: Library<70>-Footnote-44049462
Ref: Library<70>-Footnote-54049518
Ref: Library<70>-Footnote-64049574
Ref: Library<70>-Footnote-74049630
Ref: Library<70>-Footnote-84049685
Ref: Library<70>-Footnote-94049727
Ref: Library<70>-Footnote-104049783
Ref: Library<70>-Footnote-114049840
Ref: Library<70>-Footnote-124049897
Ref: Library<70>-Footnote-134049953
Ref: Library<70>-Footnote-144050010
Ref: Library<70>-Footnote-154050067
Ref: Library<70>-Footnote-164050124
Ref: Library<70>-Footnote-174050180
Ref: Library<70>-Footnote-184050237
Ref: Library<70>-Footnote-194050294
Ref: Library<70>-Footnote-204050350
Ref: Library<70>-Footnote-214050406
Ref: Library<70>-Footnote-224050462
Ref: Library<70>-Footnote-234050518
Ref: Library<70>-Footnote-244050574
Ref: Library<70>-Footnote-254050630
Ref: Library<70>-Footnote-264050686
Ref: Library<70>-Footnote-274050742
Ref: Library<70>-Footnote-284050808
Ref: Library<70>-Footnote-294050874
Ref: Library<70>-Footnote-304050940
Node: Documentation<23>4050996
Ref: whatsnew/changelog id3164051109
Ref: 1acd4051109
Ref: Documentation<23>-Footnote-14051394
Node: Tests<23>4051449
Ref: whatsnew/changelog id3174051560
Ref: 1ace4051560
Ref: Tests<23>-Footnote-14051722
Node: Build<27>4051778
Ref: whatsnew/changelog id3184051883
Ref: 1acf4051883
Ref: Build<27>-Footnote-14053322
Ref: Build<27>-Footnote-24053378
Ref: Build<27>-Footnote-34053434
Ref: Build<27>-Footnote-44053489
Ref: Build<27>-Footnote-54053545
Ref: Build<27>-Footnote-64053587
Ref: Build<27>-Footnote-74053643
Ref: Build<27>-Footnote-84053699
Ref: Build<27>-Footnote-94053754
Ref: Build<27>-Footnote-104053809
Node: Windows<24>4053865
Ref: whatsnew/changelog id3194053952
Ref: 1ad04053952
Ref: Windows<24>-Footnote-14055204
Ref: Windows<24>-Footnote-24055260
Ref: Windows<24>-Footnote-34055316
Ref: Windows<24>-Footnote-44055371
Ref: Windows<24>-Footnote-54055427
Ref: Windows<24>-Footnote-64055482
Ref: Windows<24>-Footnote-74055538
Node: Python 3 12 0 alpha 44055594
Ref: whatsnew/changelog python-3-12-0-alpha-44055721
Ref: 1ad14055721
Node: Core and Builtins<66>4056196
Ref: whatsnew/changelog id3204056295
Ref: 1ad24056295
Ref: Core and Builtins<66>-Footnote-14058201
Ref: Core and Builtins<66>-Footnote-24058257
Ref: Core and Builtins<66>-Footnote-34058312
Ref: Core and Builtins<66>-Footnote-44058367
Ref: Core and Builtins<66>-Footnote-54058423
Ref: Core and Builtins<66>-Footnote-64058479
Ref: Core and Builtins<66>-Footnote-74058535
Ref: Core and Builtins<66>-Footnote-84058591
Ref: Core and Builtins<66>-Footnote-94058647
Ref: Core and Builtins<66>-Footnote-104058703
Ref: Core and Builtins<66>-Footnote-114058759
Ref: Core and Builtins<66>-Footnote-124058802
Ref: Core and Builtins<66>-Footnote-134058859
Node: Library<71>4058916
Ref: whatsnew/changelog id3214059045
Ref: 1ad44059045
Ref: Library<71>-Footnote-14059234
Node: Core and Builtins<67>4059290
Ref: whatsnew/changelog id3224059409
Ref: 1ad64059409
Ref: Core and Builtins<67>-Footnote-14062142
Ref: Core and Builtins<67>-Footnote-24062198
Ref: Core and Builtins<67>-Footnote-34062254
Ref: Core and Builtins<67>-Footnote-44062309
Ref: Core and Builtins<67>-Footnote-54062365
Ref: Core and Builtins<67>-Footnote-64062420
Ref: Core and Builtins<67>-Footnote-74062476
Ref: Core and Builtins<67>-Footnote-84062531
Ref: Core and Builtins<67>-Footnote-94062586
Ref: Core and Builtins<67>-Footnote-104062641
Ref: Core and Builtins<67>-Footnote-114062698
Ref: Core and Builtins<67>-Footnote-124062755
Ref: Core and Builtins<67>-Footnote-134062812
Ref: Core and Builtins<67>-Footnote-144062869
Ref: Core and Builtins<67>-Footnote-154062925
Ref: Core and Builtins<67>-Footnote-164062981
Ref: Core and Builtins<67>-Footnote-174063037
Ref: Core and Builtins<67>-Footnote-184063093
Node: Library<72>4063149
Ref: whatsnew/changelog id3234063278
Ref: 1ad84063278
Ref: Library<72>-Footnote-14063416
Node: Core and Builtins<68>4063471
Ref: whatsnew/changelog id3244063590
Ref: 1ada4063590
Ref: Core and Builtins<68>-Footnote-14063865
Node: Library<73>4063930
Ref: whatsnew/changelog id3254064055
Ref: 1adb4064055
Ref: Library<73>-Footnote-14074352
Ref: Library<73>-Footnote-24074408
Ref: Library<73>-Footnote-34074464
Ref: Library<73>-Footnote-44074520
Ref: Library<73>-Footnote-54074576
Ref: Library<73>-Footnote-64074631
Ref: Library<73>-Footnote-74074686
Ref: Library<73>-Footnote-84074742
Ref: Library<73>-Footnote-94074798
Ref: Library<73>-Footnote-104074853
Ref: Library<73>-Footnote-114074910
Ref: Library<73>-Footnote-124074966
Ref: Library<73>-Footnote-134075023
Ref: Library<73>-Footnote-144075079
Ref: Library<73>-Footnote-154075135
Ref: Library<73>-Footnote-164075192
Ref: Library<73>-Footnote-174075249
Ref: Library<73>-Footnote-184075306
Ref: Library<73>-Footnote-194075363
Ref: Library<73>-Footnote-204075420
Ref: Library<73>-Footnote-214075477
Ref: Library<73>-Footnote-224075534
Ref: Library<73>-Footnote-234075590
Ref: Library<73>-Footnote-244075647
Ref: Library<73>-Footnote-254075704
Ref: Library<73>-Footnote-264075761
Ref: Library<73>-Footnote-274075817
Ref: Library<73>-Footnote-284075874
Ref: Library<73>-Footnote-294075931
Ref: Library<73>-Footnote-304075988
Ref: Library<73>-Footnote-314076045
Ref: Library<73>-Footnote-324076111
Ref: Library<73>-Footnote-334076168
Ref: Library<73>-Footnote-344076224
Ref: Library<73>-Footnote-354076280
Ref: Library<73>-Footnote-364076336
Ref: Library<73>-Footnote-374076392
Ref: Library<73>-Footnote-384076448
Ref: Library<73>-Footnote-394076504
Ref: Library<73>-Footnote-404076560
Ref: Library<73>-Footnote-414076616
Ref: Library<73>-Footnote-424076672
Ref: Library<73>-Footnote-434076715
Ref: Library<73>-Footnote-444076771
Ref: Library<73>-Footnote-454076827
Ref: Library<73>-Footnote-464076883
Ref: Library<73>-Footnote-474076939
Ref: Library<73>-Footnote-484076995
Ref: Library<73>-Footnote-494077051
Ref: Library<73>-Footnote-504077107
Ref: Library<73>-Footnote-514077163
Ref: Library<73>-Footnote-524077219
Ref: Library<73>-Footnote-534077275
Ref: Library<73>-Footnote-544077331
Ref: Library<73>-Footnote-554077397
Ref: Library<73>-Footnote-564077463
Node: Documentation<24>4077529
Ref: whatsnew/changelog id3264077642
Ref: 1ae54077642
Ref: Documentation<24>-Footnote-14078225
Ref: Documentation<24>-Footnote-24078281
Ref: Documentation<24>-Footnote-34078337
Node: Tests<24>4078402
Ref: whatsnew/changelog id3274078513
Ref: 1ae74078513
Ref: Tests<24>-Footnote-14078964
Ref: Tests<24>-Footnote-24079020
Ref: Tests<24>-Footnote-34079076
Node: Build<28>4079131
Ref: whatsnew/changelog id3284079236
Ref: 1ae84079236
Ref: Build<28>-Footnote-14080123
Ref: Build<28>-Footnote-24080179
Ref: Build<28>-Footnote-34080234
Node: Windows<25>4080299
Ref: whatsnew/changelog id3294080404
Ref: 1ae94080404
Ref: Windows<25>-Footnote-14081331
Ref: Windows<25>-Footnote-24081387
Ref: Windows<25>-Footnote-34081442
Ref: Windows<25>-Footnote-44081497
Ref: Windows<25>-Footnote-54081552
Ref: Windows<25>-Footnote-64081617
Node: macOS<16>4081682
Ref: whatsnew/changelog id3304081793
Ref: 1aec4081793
Ref: macOS<16>-Footnote-14082077
Ref: macOS<16>-Footnote-24082133
Node: Tools/Demos<22>4082189
Ref: whatsnew/changelog id3314082298
Ref: 1aed4082298
Ref: Tools/Demos<22>-Footnote-14082674
Ref: Tools/Demos<22>-Footnote-24082739
Node: C API<26>4082795
Ref: whatsnew/changelog id3324082886
Ref: 1aee4082886
Ref: C API<26>-Footnote-14083455
Ref: C API<26>-Footnote-24083510
Ref: C API<26>-Footnote-34083565
Node: Python 3 12 0 alpha 34083620
Ref: whatsnew/changelog python-3-12-0-alpha-34083747
Ref: 1aef4083747
Node: Security<25>4084180
Ref: whatsnew/changelog id3334084280
Ref: 1af04084280
Ref: Security<25>-Footnote-14084840
Ref: Security<25>-Footnote-24084896
Node: Core and Builtins<69>4084951
Ref: whatsnew/changelog id3344085071
Ref: 1af14085071
Ref: Core and Builtins<69>-Footnote-14086391
Ref: Core and Builtins<69>-Footnote-24086446
Ref: Core and Builtins<69>-Footnote-34086501
Ref: Core and Builtins<69>-Footnote-44086556
Ref: Core and Builtins<69>-Footnote-54086611
Ref: Core and Builtins<69>-Footnote-64086666
Ref: Core and Builtins<69>-Footnote-74086721
Node: Library<74>4086776
Ref: whatsnew/changelog id3354086905
Ref: 1af24086905
Ref: Library<74>-Footnote-14087240
Ref: Library<74>-Footnote-24087295
Node: Core and Builtins<70>4087350
Ref: whatsnew/changelog id3364087469
Ref: 1af34087469
Ref: Core and Builtins<70>-Footnote-14089280
Ref: Core and Builtins<70>-Footnote-24089335
Ref: Core and Builtins<70>-Footnote-34089390
Ref: Core and Builtins<70>-Footnote-44089445
Ref: Core and Builtins<70>-Footnote-54089500
Ref: Core and Builtins<70>-Footnote-64089555
Ref: Core and Builtins<70>-Footnote-74089610
Ref: Core and Builtins<70>-Footnote-84089675
Ref: Core and Builtins<70>-Footnote-94089740
Node: Library<75>4089805
Ref: whatsnew/changelog id3374089930
Ref: 1af44089930
Ref: Library<75>-Footnote-14096170
Ref: Library<75>-Footnote-24096226
Ref: Library<75>-Footnote-34096281
Ref: Library<75>-Footnote-44096336
Ref: Library<75>-Footnote-54096391
Ref: Library<75>-Footnote-64096446
Ref: Library<75>-Footnote-74096501
Ref: Library<75>-Footnote-84096556
Ref: Library<75>-Footnote-94096611
Ref: Library<75>-Footnote-104096666
Ref: Library<75>-Footnote-114096722
Ref: Library<75>-Footnote-124096778
Ref: Library<75>-Footnote-134096834
Ref: Library<75>-Footnote-144096890
Ref: Library<75>-Footnote-154096946
Ref: Library<75>-Footnote-164097002
Ref: Library<75>-Footnote-174097058
Ref: Library<75>-Footnote-184097114
Ref: Library<75>-Footnote-194097170
Ref: Library<75>-Footnote-204097226
Ref: Library<75>-Footnote-214097282
Ref: Library<75>-Footnote-224097338
Ref: Library<75>-Footnote-234097394
Ref: Library<75>-Footnote-244097450
Ref: Library<75>-Footnote-254097506
Ref: Library<75>-Footnote-264097562
Ref: Library<75>-Footnote-274097618
Ref: Library<75>-Footnote-284097674
Ref: Library<75>-Footnote-294097730
Ref: Library<75>-Footnote-304097786
Ref: Library<75>-Footnote-314097842
Ref: Library<75>-Footnote-324097908
Ref: Library<75>-Footnote-334097974
Ref: Library<75>-Footnote-344098040
Node: Documentation<25>4098106
Ref: whatsnew/changelog id3384098219
Ref: 1af84098219
Ref: Documentation<25>-Footnote-14098988
Ref: Documentation<25>-Footnote-24099043
Ref: Documentation<25>-Footnote-34099095
Ref: Documentation<25>-Footnote-44099119
Ref: Documentation<25>-Footnote-54099174
Ref: Documentation<25>-Footnote-64099229
Ref: Documentation<25>-Footnote-74099284
Node: Tests<25>4099349
Ref: whatsnew/changelog id3394099460
Ref: 1af94099460
Ref: Tests<25>-Footnote-14100237
Ref: Tests<25>-Footnote-24100292
Ref: Tests<25>-Footnote-34100347
Ref: Tests<25>-Footnote-44100402
Ref: Tests<25>-Footnote-54100457
Ref: Tests<25>-Footnote-64100512
Node: Build<29>4100567
Ref: whatsnew/changelog id3404100672
Ref: 1afa4100672
Ref: Build<29>-Footnote-14101636
Ref: Build<29>-Footnote-24101691
Ref: Build<29>-Footnote-34101746
Ref: Build<29>-Footnote-44101801
Ref: Build<29>-Footnote-54101856
Node: Windows<26>4101911
Ref: whatsnew/changelog id3414102016
Ref: 1afb4102016
Ref: Windows<26>-Footnote-14102545
Ref: Windows<26>-Footnote-24102600
Ref: Windows<26>-Footnote-34102655
Ref: Windows<26>-Footnote-44102710
Node: macOS<17>4102775
Ref: whatsnew/changelog id3424102886
Ref: 1afc4102886
Ref: macOS<17>-Footnote-14103156
Ref: macOS<17>-Footnote-24103211
Node: Tools/Demos<23>4103266
Ref: whatsnew/changelog id3434103375
Ref: 1afd4103375
Ref: Tools/Demos<23>-Footnote-14103867
Node: C API<27>4103922
Ref: whatsnew/changelog id3444104013
Ref: 1afe4104013
Ref: C API<27>-Footnote-14104834
Ref: C API<27>-Footnote-24104889
Ref: C API<27>-Footnote-34104944
Node: Python 3 12 0 alpha 24104999
Ref: whatsnew/changelog python-3-12-0-alpha-24105126
Ref: 1b004105126
Node: Security<26>4105523
Ref: whatsnew/changelog id3454105623
Ref: 1b014105623
Ref: Security<26>-Footnote-14106754
Ref: Security<26>-Footnote-24106809
Ref: Security<26>-Footnote-34106868
Ref: Security<26>-Footnote-44106927
Ref: Security<26>-Footnote-54106986
Node: Core and Builtins<71>4107041
Ref: whatsnew/changelog id3464107159
Ref: 1b024107159
Ref: Core and Builtins<71>-Footnote-14113903
Ref: Core and Builtins<71>-Footnote-24113958
Ref: Core and Builtins<71>-Footnote-34114013
Ref: Core and Builtins<71>-Footnote-44114068
Ref: Core and Builtins<71>-Footnote-54114123
Ref: Core and Builtins<71>-Footnote-64114178
Ref: Core and Builtins<71>-Footnote-74114233
Ref: Core and Builtins<71>-Footnote-84114288
Ref: Core and Builtins<71>-Footnote-94114343
Ref: Core and Builtins<71>-Footnote-104114398
Ref: Core and Builtins<71>-Footnote-114114454
Ref: Core and Builtins<71>-Footnote-124114510
Ref: Core and Builtins<71>-Footnote-134114566
Ref: Core and Builtins<71>-Footnote-144114622
Ref: Core and Builtins<71>-Footnote-154114678
Ref: Core and Builtins<71>-Footnote-164114734
Ref: Core and Builtins<71>-Footnote-174114790
Ref: Core and Builtins<71>-Footnote-184114846
Ref: Core and Builtins<71>-Footnote-194114902
Ref: Core and Builtins<71>-Footnote-204114958
Ref: Core and Builtins<71>-Footnote-214115014
Ref: Core and Builtins<71>-Footnote-224115070
Ref: Core and Builtins<71>-Footnote-234115126
Ref: Core and Builtins<71>-Footnote-244115182
Ref: Core and Builtins<71>-Footnote-254115225
Ref: Core and Builtins<71>-Footnote-264115281
Ref: Core and Builtins<71>-Footnote-274115337
Node: Build<30>4115393
Ref: whatsnew/changelog id3474115520
Ref: 1b094115520
Ref: Build<30>-Footnote-14115705
Node: Core and Builtins<72>4115760
Ref: whatsnew/changelog id3484115877
Ref: 1b0a4115877
Ref: Core and Builtins<72>-Footnote-14117014
Ref: Core and Builtins<72>-Footnote-24117069
Ref: Core and Builtins<72>-Footnote-34117124
Ref: Core and Builtins<72>-Footnote-44117179
Ref: Core and Builtins<72>-Footnote-54117234
Ref: Core and Builtins<72>-Footnote-64117289
Node: Library<76>4117344
Ref: whatsnew/changelog id3494117469
Ref: 1b0d4117469
Ref: Library<76>-Footnote-14123378
Ref: Library<76>-Footnote-24123433
Ref: Library<76>-Footnote-34123488
Ref: Library<76>-Footnote-44123543
Ref: Library<76>-Footnote-54123598
Ref: Library<76>-Footnote-64123653
Ref: Library<76>-Footnote-74123708
Ref: Library<76>-Footnote-84123763
Ref: Library<76>-Footnote-94123818
Ref: Library<76>-Footnote-104123873
Ref: Library<76>-Footnote-114123929
Ref: Library<76>-Footnote-124123985
Ref: Library<76>-Footnote-134124041
Ref: Library<76>-Footnote-144124084
Ref: Library<76>-Footnote-154124140
Ref: Library<76>-Footnote-164124196
Ref: Library<76>-Footnote-174124252
Ref: Library<76>-Footnote-184124308
Ref: Library<76>-Footnote-194124364
Ref: Library<76>-Footnote-204124420
Ref: Library<76>-Footnote-214124476
Ref: Library<76>-Footnote-224124532
Ref: Library<76>-Footnote-234124588
Ref: Library<76>-Footnote-244124644
Ref: Library<76>-Footnote-254124700
Ref: Library<76>-Footnote-264124756
Ref: Library<76>-Footnote-274124812
Ref: Library<76>-Footnote-284124868
Ref: Library<76>-Footnote-294124924
Ref: Library<76>-Footnote-304124980
Ref: Library<76>-Footnote-314125036
Ref: Library<76>-Footnote-324125092
Ref: Library<76>-Footnote-334125135
Ref: Library<76>-Footnote-344125191
Ref: Library<76>-Footnote-354125247
Ref: Library<76>-Footnote-364125303
Ref: Library<76>-Footnote-374125359
Ref: Library<76>-Footnote-384125402
Ref: Library<76>-Footnote-394125458
Ref: Library<76>-Footnote-404125514
Ref: Library<76>-Footnote-414125580
Ref: Library<76>-Footnote-424125646
Node: Documentation<26>4125712
Ref: whatsnew/changelog id3504125825
Ref: 1b124125825
Ref: Documentation<26>-Footnote-14126143
Ref: Documentation<26>-Footnote-24126198
Node: Tests<26>4126253
Ref: whatsnew/changelog id3514126364
Ref: 1b134126364
Ref: Tests<26>-Footnote-14127252
Ref: Tests<26>-Footnote-24127307
Ref: Tests<26>-Footnote-34127362
Ref: Tests<26>-Footnote-44127417
Ref: Tests<26>-Footnote-54127472
Node: Build<31>4127537
Ref: whatsnew/changelog id3524127642
Ref: 1b144127642
Ref: Build<31>-Footnote-14129335
Ref: Build<31>-Footnote-24129390
Ref: Build<31>-Footnote-34129445
Ref: Build<31>-Footnote-44129500
Ref: Build<31>-Footnote-54129555
Ref: Build<31>-Footnote-64129610
Ref: Build<31>-Footnote-74129665
Ref: Build<31>-Footnote-84129755
Ref: Build<31>-Footnote-94129810
Ref: Build<31>-Footnote-104129865
Node: Windows<27>4129921
Ref: whatsnew/changelog id3534130026
Ref: 1b164130026
Ref: Windows<27>-Footnote-14130721
Ref: Windows<27>-Footnote-24130776
Ref: Windows<27>-Footnote-34130832
Ref: Windows<27>-Footnote-44130887
Ref: Windows<27>-Footnote-54130942
Ref: Windows<27>-Footnote-64130997
Node: macOS<18>4131052
Ref: whatsnew/changelog id3544131157
Ref: 1b174131157
Ref: macOS<18>-Footnote-14131288
Node: C API<28>4131343
Ref: whatsnew/changelog id3554131428
Ref: 1b184131428
Ref: C API<28>-Footnote-14133501
Ref: C API<28>-Footnote-24133556
Ref: C API<28>-Footnote-34133611
Ref: C API<28>-Footnote-44133666
Ref: C API<28>-Footnote-54133721
Ref: C API<28>-Footnote-64133776
Ref: C API<28>-Footnote-74133831
Node: Python 3 12 0 alpha 14133886
Ref: whatsnew/changelog python-3-12-0-alpha-14134012
Ref: 1b1a4134012
Node: Security<27>4135007
Ref: whatsnew/changelog id3564135107
Ref: 1b1b4135107
Ref: Security<27>-Footnote-14136942
Ref: Security<27>-Footnote-24136997
Ref: Security<27>-Footnote-34137052
Ref: Security<27>-Footnote-44137124
Ref: Security<27>-Footnote-54137180
Ref: Security<27>-Footnote-64137235
Ref: Security<27>-Footnote-74137290
Ref: Security<27>-Footnote-84137345
Node: Core and Builtins<73>4137400
Ref: whatsnew/changelog id3574137520
Ref: 1b1c4137520
Ref: Core and Builtins<73>-Footnote-14138800
Ref: Core and Builtins<73>-Footnote-24138855
Ref: Core and Builtins<73>-Footnote-34138910
Ref: Core and Builtins<73>-Footnote-44138965
Ref: Core and Builtins<73>-Footnote-54139020
Ref: Core and Builtins<73>-Footnote-64139075
Ref: Core and Builtins<73>-Footnote-74139130
Ref: Core and Builtins<73>-Footnote-84139185
Node: Library<77>4139240
Ref: whatsnew/changelog id3584139369
Ref: 1b1d4139369
Ref: Library<77>-Footnote-14139636
Ref: Library<77>-Footnote-24139691
Node: Core and Builtins<74>4139746
Ref: whatsnew/changelog id3594139865
Ref: 1b1e4139865
Ref: Core and Builtins<74>-Footnote-14143310
Ref: Core and Builtins<74>-Footnote-24143365
Ref: Core and Builtins<74>-Footnote-34143420
Ref: Core and Builtins<74>-Footnote-44143475
Ref: Core and Builtins<74>-Footnote-54143530
Ref: Core and Builtins<74>-Footnote-64143585
Ref: Core and Builtins<74>-Footnote-74143640
Ref: Core and Builtins<74>-Footnote-84143695
Ref: Core and Builtins<74>-Footnote-94143750
Ref: Core and Builtins<74>-Footnote-104143805
Ref: Core and Builtins<74>-Footnote-114143861
Ref: Core and Builtins<74>-Footnote-124143917
Ref: Core and Builtins<74>-Footnote-134143973
Ref: Core and Builtins<74>-Footnote-144144029
Ref: Core and Builtins<74>-Footnote-154144085
Ref: Core and Builtins<74>-Footnote-164144141
Ref: Core and Builtins<74>-Footnote-174144197
Node: Library<78>4144253
Ref: whatsnew/changelog id3604144382
Ref: 1b234144382
Ref: Library<78>-Footnote-14144518
Node: Core and Builtins<75>4144573
Ref: whatsnew/changelog id3614144692
Ref: 1b244144692
Ref: Core and Builtins<75>-Footnote-14146419
Ref: Core and Builtins<75>-Footnote-24146474
Ref: Core and Builtins<75>-Footnote-34146529
Ref: Core and Builtins<75>-Footnote-44146584
Ref: Core and Builtins<75>-Footnote-54146639
Ref: Core and Builtins<75>-Footnote-64146694
Ref: Core and Builtins<75>-Footnote-74146749
Ref: Core and Builtins<75>-Footnote-84146804
Ref: Core and Builtins<75>-Footnote-94146859
Ref: Core and Builtins<75>-Footnote-104146914
Ref: Core and Builtins<75>-Footnote-114146970
Node: Library<79>4147026
Ref: whatsnew/changelog id3624147155
Ref: 1b254147155
Ref: Library<79>-Footnote-14147363
Ref: Library<79>-Footnote-24147418
Node: Core and Builtins<76>4147473
Ref: whatsnew/changelog id3634147592
Ref: 1b264147592
Ref: Core and Builtins<76>-Footnote-14156855
Ref: Core and Builtins<76>-Footnote-24156910
Ref: Core and Builtins<76>-Footnote-34156965
Ref: Core and Builtins<76>-Footnote-44157020
Ref: Core and Builtins<76>-Footnote-54157075
Ref: Core and Builtins<76>-Footnote-64157130
Ref: Core and Builtins<76>-Footnote-74157185
Ref: Core and Builtins<76>-Footnote-84157227
Ref: Core and Builtins<76>-Footnote-94157282
Ref: Core and Builtins<76>-Footnote-104157337
Ref: Core and Builtins<76>-Footnote-114157393
Ref: Core and Builtins<76>-Footnote-124157449
Ref: Core and Builtins<76>-Footnote-134157505
Ref: Core and Builtins<76>-Footnote-144157561
Ref: Core and Builtins<76>-Footnote-154157617
Ref: Core and Builtins<76>-Footnote-164157673
Ref: Core and Builtins<76>-Footnote-174157729
Ref: Core and Builtins<76>-Footnote-184157785
Ref: Core and Builtins<76>-Footnote-194157841
Ref: Core and Builtins<76>-Footnote-204157897
Ref: Core and Builtins<76>-Footnote-214157953
Ref: Core and Builtins<76>-Footnote-224158009
Ref: Core and Builtins<76>-Footnote-234158065
Ref: Core and Builtins<76>-Footnote-244158121
Ref: Core and Builtins<76>-Footnote-254158177
Ref: Core and Builtins<76>-Footnote-264158233
Ref: Core and Builtins<76>-Footnote-274158289
Ref: Core and Builtins<76>-Footnote-284158345
Ref: Core and Builtins<76>-Footnote-294158401
Ref: Core and Builtins<76>-Footnote-304158457
Ref: Core and Builtins<76>-Footnote-314158513
Ref: Core and Builtins<76>-Footnote-324158569
Ref: Core and Builtins<76>-Footnote-334158625
Ref: Core and Builtins<76>-Footnote-344158681
Ref: Core and Builtins<76>-Footnote-354158737
Ref: Core and Builtins<76>-Footnote-364158793
Ref: Core and Builtins<76>-Footnote-374158849
Ref: Core and Builtins<76>-Footnote-384158905
Ref: Core and Builtins<76>-Footnote-394158961
Ref: Core and Builtins<76>-Footnote-404159017
Ref: Core and Builtins<76>-Footnote-414159073
Ref: Core and Builtins<76>-Footnote-424159129
Ref: Core and Builtins<76>-Footnote-434159185
Ref: Core and Builtins<76>-Footnote-444159241
Ref: Core and Builtins<76>-Footnote-454159297
Ref: Core and Builtins<76>-Footnote-464159353
Node: Library<80>4159409
Ref: whatsnew/changelog id3644159538
Ref: 1b284159538
Ref: Library<80>-Footnote-14159732
Node: Core and Builtins<77>4159787
Ref: whatsnew/changelog id3654159906
Ref: 1b2b4159906
Ref: Core and Builtins<77>-Footnote-14160374
Ref: Core and Builtins<77>-Footnote-24160429
Node: Library<81>4160484
Ref: whatsnew/changelog id3664160613
Ref: 1b2c4160613
Ref: Library<81>-Footnote-14160894
Node: Core and Builtins<78>4160949
Ref: whatsnew/changelog id3674161068
Ref: 1b2d4161068
Ref: Core and Builtins<78>-Footnote-14161264
Node: Library<82>4161319
Ref: whatsnew/changelog id3684161448
Ref: 1b2e4161448
Ref: Library<82>-Footnote-14161891
Ref: Library<82>-Footnote-24161946
Node: Core and Builtins<79>4162001
Ref: whatsnew/changelog id3694162120
Ref: 1b2f4162120
Ref: Core and Builtins<79>-Footnote-14167612
Ref: Core and Builtins<79>-Footnote-24167667
Ref: Core and Builtins<79>-Footnote-34167722
Ref: Core and Builtins<79>-Footnote-44167777
Ref: Core and Builtins<79>-Footnote-54167832
Ref: Core and Builtins<79>-Footnote-64167887
Ref: Core and Builtins<79>-Footnote-74167942
Ref: Core and Builtins<79>-Footnote-84167997
Ref: Core and Builtins<79>-Footnote-94168052
Ref: Core and Builtins<79>-Footnote-104168107
Ref: Core and Builtins<79>-Footnote-114168163
Ref: Core and Builtins<79>-Footnote-124168219
Ref: Core and Builtins<79>-Footnote-134168262
Ref: Core and Builtins<79>-Footnote-144168318
Ref: Core and Builtins<79>-Footnote-154168374
Ref: Core and Builtins<79>-Footnote-164168430
Ref: Core and Builtins<79>-Footnote-174168486
Ref: Core and Builtins<79>-Footnote-184168542
Ref: Core and Builtins<79>-Footnote-194168598
Ref: Core and Builtins<79>-Footnote-204168654
Ref: Core and Builtins<79>-Footnote-214168710
Ref: Core and Builtins<79>-Footnote-224168766
Ref: Core and Builtins<79>-Footnote-234168822
Ref: Core and Builtins<79>-Footnote-244168878
Ref: Core and Builtins<79>-Footnote-254168934
Ref: Core and Builtins<79>-Footnote-264168990
Ref: Core and Builtins<79>-Footnote-274169046
Ref: Core and Builtins<79>-Footnote-284169102
Ref: Core and Builtins<79>-Footnote-294169158
Ref: Core and Builtins<79>-Footnote-304169214
Ref: Core and Builtins<79>-Footnote-314169270
Ref: Core and Builtins<79>-Footnote-324169326
Ref: Core and Builtins<79>-Footnote-334169382
Ref: Core and Builtins<79>-Footnote-344169438
Node: Library<83>4169494
Ref: whatsnew/changelog id3704169623
Ref: 1b304169623
Ref: Library<83>-Footnote-14170058
Node: Core and Builtins<80>4170113
Ref: whatsnew/changelog id3714170232
Ref: 1b314170232
Ref: Core and Builtins<80>-Footnote-14175500
Ref: Core and Builtins<80>-Footnote-24175555
Ref: Core and Builtins<80>-Footnote-34175610
Ref: Core and Builtins<80>-Footnote-44175665
Ref: Core and Builtins<80>-Footnote-54175720
Ref: Core and Builtins<80>-Footnote-64175775
Ref: Core and Builtins<80>-Footnote-74175830
Ref: Core and Builtins<80>-Footnote-84175885
Ref: Core and Builtins<80>-Footnote-94175940
Ref: Core and Builtins<80>-Footnote-104175995
Ref: Core and Builtins<80>-Footnote-114176051
Ref: Core and Builtins<80>-Footnote-124176107
Ref: Core and Builtins<80>-Footnote-134176163
Ref: Core and Builtins<80>-Footnote-144176219
Ref: Core and Builtins<80>-Footnote-154176275
Ref: Core and Builtins<80>-Footnote-164176331
Ref: Core and Builtins<80>-Footnote-174176387
Ref: Core and Builtins<80>-Footnote-184176443
Ref: Core and Builtins<80>-Footnote-194176499
Ref: Core and Builtins<80>-Footnote-204176559
Ref: Core and Builtins<80>-Footnote-214176615
Ref: Core and Builtins<80>-Footnote-224176671
Ref: Core and Builtins<80>-Footnote-234176727
Ref: Core and Builtins<80>-Footnote-244176783
Ref: Core and Builtins<80>-Footnote-254176839
Ref: Core and Builtins<80>-Footnote-264176895
Ref: Core and Builtins<80>-Footnote-274176951
Ref: Core and Builtins<80>-Footnote-284177007
Ref: Core and Builtins<80>-Footnote-294177063
Ref: Core and Builtins<80>-Footnote-304177119
Ref: Core and Builtins<80>-Footnote-314177175
Ref: Core and Builtins<80>-Footnote-324177231
Node: Library<84>4177287
Ref: whatsnew/changelog id3724177416
Ref: 1b324177416
Ref: Library<84>-Footnote-14177577
Node: Core and Builtins<81>4177632
Ref: whatsnew/changelog id3734177751
Ref: 1b334177751
Ref: Core and Builtins<81>-Footnote-14178205
Ref: Core and Builtins<81>-Footnote-24178260
Node: Library<85>4178315
Ref: whatsnew/changelog id3744178444
Ref: 1b344178444
Ref: Library<85>-Footnote-14178597
Node: Core and Builtins<82>4178652
Ref: whatsnew/changelog id3754178771
Ref: 1b354178771
Ref: Core and Builtins<82>-Footnote-14179643
Ref: Core and Builtins<82>-Footnote-24179698
Ref: Core and Builtins<82>-Footnote-34179753
Ref: Core and Builtins<82>-Footnote-44179808
Ref: Core and Builtins<82>-Footnote-54179873
Ref: Core and Builtins<82>-Footnote-64179938
Node: Library<86>4180003
Ref: whatsnew/changelog id3764180128
Ref: 1b364180128
Ref: Library<86>-Footnote-14223386
Ref: Library<86>-Footnote-24223441
Ref: Library<86>-Footnote-34223496
Ref: Library<86>-Footnote-44223551
Ref: Library<86>-Footnote-54223606
Ref: Library<86>-Footnote-64223661
Ref: Library<86>-Footnote-74223716
Ref: Library<86>-Footnote-84223771
Ref: Library<86>-Footnote-94223826
Ref: Library<86>-Footnote-104223881
Ref: Library<86>-Footnote-114223937
Ref: Library<86>-Footnote-124223993
Ref: Library<86>-Footnote-134224049
Ref: Library<86>-Footnote-144224105
Ref: Library<86>-Footnote-154224161
Ref: Library<86>-Footnote-164224217
Ref: Library<86>-Footnote-174224273
Ref: Library<86>-Footnote-184224329
Ref: Library<86>-Footnote-194224385
Ref: Library<86>-Footnote-204224445
Ref: Library<86>-Footnote-214224501
Ref: Library<86>-Footnote-224224557
Ref: Library<86>-Footnote-234224613
Ref: Library<86>-Footnote-244224669
Ref: Library<86>-Footnote-254224725
Ref: Library<86>-Footnote-264224781
Ref: Library<86>-Footnote-274224837
Ref: Library<86>-Footnote-284224893
Ref: Library<86>-Footnote-294224949
Ref: Library<86>-Footnote-304225005
Ref: Library<86>-Footnote-314225061
Ref: Library<86>-Footnote-324225117
Ref: Library<86>-Footnote-334225173
Ref: Library<86>-Footnote-344225229
Ref: Library<86>-Footnote-354225285
Ref: Library<86>-Footnote-364225341
Ref: Library<86>-Footnote-374225397
Ref: Library<86>-Footnote-384225453
Ref: Library<86>-Footnote-394225509
Ref: Library<86>-Footnote-404225565
Ref: Library<86>-Footnote-414225621
Ref: Library<86>-Footnote-424225677
Ref: Library<86>-Footnote-434225733
Ref: Library<86>-Footnote-444225789
Ref: Library<86>-Footnote-454225845
Ref: Library<86>-Footnote-464225901
Ref: Library<86>-Footnote-474225957
Ref: Library<86>-Footnote-484226013
Ref: Library<86>-Footnote-494226069
Ref: Library<86>-Footnote-504226125
Ref: Library<86>-Footnote-514226181
Ref: Library<86>-Footnote-524226237
Ref: Library<86>-Footnote-534226293
Ref: Library<86>-Footnote-544226349
Ref: Library<86>-Footnote-554226405
Ref: Library<86>-Footnote-564226461
Ref: Library<86>-Footnote-574226517
Ref: Library<86>-Footnote-584226573
Ref: Library<86>-Footnote-594226629
Ref: Library<86>-Footnote-604226685
Ref: Library<86>-Footnote-614226741
Ref: Library<86>-Footnote-624226797
Ref: Library<86>-Footnote-634226853
Ref: Library<86>-Footnote-644226909
Ref: Library<86>-Footnote-654226965
Ref: Library<86>-Footnote-664227021
Ref: Library<86>-Footnote-674227077
Ref: Library<86>-Footnote-684227143
Ref: Library<86>-Footnote-694227199
Ref: Library<86>-Footnote-704227255
Ref: Library<86>-Footnote-714227311
Ref: Library<86>-Footnote-724227367
Ref: Library<86>-Footnote-734227423
Ref: Library<86>-Footnote-744227479
Ref: Library<86>-Footnote-754227535
Ref: Library<86>-Footnote-764227591
Ref: Library<86>-Footnote-774227647
Ref: Library<86>-Footnote-784227703
Ref: Library<86>-Footnote-794227759
Ref: Library<86>-Footnote-804227815
Ref: Library<86>-Footnote-814227871
Ref: Library<86>-Footnote-824227927
Ref: Library<86>-Footnote-834227983
Ref: Library<86>-Footnote-844228039
Ref: Library<86>-Footnote-854228095
Ref: Library<86>-Footnote-864228151
Ref: Library<86>-Footnote-874228207
Ref: Library<86>-Footnote-884228263
Ref: Library<86>-Footnote-894228319
Ref: Library<86>-Footnote-904228375
Ref: Library<86>-Footnote-914228431
Ref: Library<86>-Footnote-924228487
Ref: Library<86>-Footnote-934228543
Ref: Library<86>-Footnote-944228599
Ref: Library<86>-Footnote-954228655
Ref: Library<86>-Footnote-964228711
Ref: Library<86>-Footnote-974228767
Ref: Library<86>-Footnote-984228823
Ref: Library<86>-Footnote-994228879
Ref: Library<86>-Footnote-1004228935
Ref: Library<86>-Footnote-1014228992
Ref: Library<86>-Footnote-1024229049
Ref: Library<86>-Footnote-1034229106
Ref: Library<86>-Footnote-1044229163
Ref: Library<86>-Footnote-1054229220
Ref: Library<86>-Footnote-1064229277
Ref: Library<86>-Footnote-1074229334
Ref: Library<86>-Footnote-1084229391
Ref: Library<86>-Footnote-1094229448
Ref: Library<86>-Footnote-1104229505
Ref: Library<86>-Footnote-1114229562
Ref: Library<86>-Footnote-1124229619
Ref: Library<86>-Footnote-1134229676
Ref: Library<86>-Footnote-1144229733
Ref: Library<86>-Footnote-1154229790
Ref: Library<86>-Footnote-1164229847
Ref: Library<86>-Footnote-1174229904
Ref: Library<86>-Footnote-1184229961
Ref: Library<86>-Footnote-1194230018
Ref: Library<86>-Footnote-1204230075
Ref: Library<86>-Footnote-1214230132
Ref: Library<86>-Footnote-1224230189
Ref: Library<86>-Footnote-1234230246
Ref: Library<86>-Footnote-1244230290
Ref: Library<86>-Footnote-1254230347
Ref: Library<86>-Footnote-1264230404
Ref: Library<86>-Footnote-1274230461
Ref: Library<86>-Footnote-1284230518
Ref: Library<86>-Footnote-1294230575
Ref: Library<86>-Footnote-1304230632
Ref: Library<86>-Footnote-1314230689
Ref: Library<86>-Footnote-1324230746
Ref: Library<86>-Footnote-1334230803
Ref: Library<86>-Footnote-1344230860
Ref: Library<86>-Footnote-1354230917
Ref: Library<86>-Footnote-1364230974
Ref: Library<86>-Footnote-1374231031
Ref: Library<86>-Footnote-1384231088
Ref: Library<86>-Footnote-1394231145
Ref: Library<86>-Footnote-1404231203
Ref: Library<86>-Footnote-1414231260
Ref: Library<86>-Footnote-1424231317
Ref: Library<86>-Footnote-1434231361
Ref: Library<86>-Footnote-1444231418
Ref: Library<86>-Footnote-1454231475
Ref: Library<86>-Footnote-1464231532
Ref: Library<86>-Footnote-1474231589
Ref: Library<86>-Footnote-1484231646
Ref: Library<86>-Footnote-1494231703
Ref: Library<86>-Footnote-1504231760
Ref: Library<86>-Footnote-1514231817
Ref: Library<86>-Footnote-1524231874
Ref: Library<86>-Footnote-1534231931
Ref: Library<86>-Footnote-1544231988
Ref: Library<86>-Footnote-1554232045
Ref: Library<86>-Footnote-1564232102
Ref: Library<86>-Footnote-1574232159
Ref: Library<86>-Footnote-1584232216
Ref: Library<86>-Footnote-1594232273
Ref: Library<86>-Footnote-1604232330
Ref: Library<86>-Footnote-1614232387
Ref: Library<86>-Footnote-1624232444
Ref: Library<86>-Footnote-1634232488
Ref: Library<86>-Footnote-1644232545
Ref: Library<86>-Footnote-1654232602
Ref: Library<86>-Footnote-1664232659
Ref: Library<86>-Footnote-1674232716
Ref: Library<86>-Footnote-1684232773
Ref: Library<86>-Footnote-1694232830
Ref: Library<86>-Footnote-1704232887
Ref: Library<86>-Footnote-1714232944
Ref: Library<86>-Footnote-1724233001
Ref: Library<86>-Footnote-1734233058
Ref: Library<86>-Footnote-1744233115
Ref: Library<86>-Footnote-1754233172
Ref: Library<86>-Footnote-1764233229
Ref: Library<86>-Footnote-1774233286
Ref: Library<86>-Footnote-1784233343
Ref: Library<86>-Footnote-1794233400
Ref: Library<86>-Footnote-1804233457
Ref: Library<86>-Footnote-1814233514
Ref: Library<86>-Footnote-1824233558
Ref: Library<86>-Footnote-1834233615
Ref: Library<86>-Footnote-1844233672
Ref: Library<86>-Footnote-1854233729
Ref: Library<86>-Footnote-1864233786
Ref: Library<86>-Footnote-1874233843
Ref: Library<86>-Footnote-1884233900
Ref: Library<86>-Footnote-1894233957
Ref: Library<86>-Footnote-1904234014
Ref: Library<86>-Footnote-1914234071
Ref: Library<86>-Footnote-1924234128
Ref: Library<86>-Footnote-1934234185
Ref: Library<86>-Footnote-1944234242
Ref: Library<86>-Footnote-1954234299
Ref: Library<86>-Footnote-1964234356
Ref: Library<86>-Footnote-1974234413
Ref: Library<86>-Footnote-1984234470
Ref: Library<86>-Footnote-1994234527
Ref: Library<86>-Footnote-2004234584
Ref: Library<86>-Footnote-2014234641
Ref: Library<86>-Footnote-2024234698
Ref: Library<86>-Footnote-2034234755
Ref: Library<86>-Footnote-2044234812
Ref: Library<86>-Footnote-2054234869
Ref: Library<86>-Footnote-2064234926
Ref: Library<86>-Footnote-2074234983
Ref: Library<86>-Footnote-2084235040
Ref: Library<86>-Footnote-2094235097
Ref: Library<86>-Footnote-2104235154
Ref: Library<86>-Footnote-2114235211
Ref: Library<86>-Footnote-2124235268
Ref: Library<86>-Footnote-2134235325
Ref: Library<86>-Footnote-2144235382
Ref: Library<86>-Footnote-2154235439
Ref: Library<86>-Footnote-2164235496
Ref: Library<86>-Footnote-2174235553
Ref: Library<86>-Footnote-2184235610
Ref: Library<86>-Footnote-2194235667
Ref: Library<86>-Footnote-2204235724
Ref: Library<86>-Footnote-2214235781
Ref: Library<86>-Footnote-2224235838
Ref: Library<86>-Footnote-2234235895
Ref: Library<86>-Footnote-2244235952
Ref: Library<86>-Footnote-2254236009
Ref: Library<86>-Footnote-2264236066
Ref: Library<86>-Footnote-2274236133
Ref: Library<86>-Footnote-2284236200
Ref: Library<86>-Footnote-2294236267
Ref: Library<86>-Footnote-2304236324
Ref: Library<86>-Footnote-2314236391
Ref: Library<86>-Footnote-2324236458
Ref: Library<86>-Footnote-2334236525
Ref: Library<86>-Footnote-2344236592
Ref: Library<86>-Footnote-2354236659
Ref: Library<86>-Footnote-2364236726
Ref: Library<86>-Footnote-2374236793
Ref: Library<86>-Footnote-2384236860
Ref: Library<86>-Footnote-2394236927
Ref: Library<86>-Footnote-2404236994
Ref: Library<86>-Footnote-2414237061
Ref: Library<86>-Footnote-2424237128
Ref: Library<86>-Footnote-2434237195
Ref: Library<86>-Footnote-2444237262
Ref: Library<86>-Footnote-2454237329
Ref: Library<86>-Footnote-2464237396
Ref: Library<86>-Footnote-2474237463
Ref: Library<86>-Footnote-2484237530
Ref: Library<86>-Footnote-2494237597
Ref: Library<86>-Footnote-2504237664
Ref: Library<86>-Footnote-2514237731
Ref: Library<86>-Footnote-2524237798
Ref: Library<86>-Footnote-2534237865
Ref: Library<86>-Footnote-2544237932
Node: Documentation<27>4237999
Ref: whatsnew/changelog id3774238112
Ref: 1b514238112
Ref: Documentation<27>-Footnote-14241852
Ref: Documentation<27>-Footnote-24241907
Ref: Documentation<27>-Footnote-34241962
Ref: Documentation<27>-Footnote-44242008
Ref: Documentation<27>-Footnote-54242063
Ref: Documentation<27>-Footnote-64242118
Ref: Documentation<27>-Footnote-74242173
Ref: Documentation<27>-Footnote-84242228
Ref: Documentation<27>-Footnote-94242283
Ref: Documentation<27>-Footnote-104242338
Ref: Documentation<27>-Footnote-114242394
Ref: Documentation<27>-Footnote-124242450
Ref: Documentation<27>-Footnote-134242506
Ref: Documentation<27>-Footnote-144242562
Ref: Documentation<27>-Footnote-154242605
Ref: Documentation<27>-Footnote-164242661
Ref: Documentation<27>-Footnote-174242717
Ref: Documentation<27>-Footnote-184242773
Ref: Documentation<27>-Footnote-194242829
Ref: Documentation<27>-Footnote-204242885
Ref: Documentation<27>-Footnote-214242941
Ref: Documentation<27>-Footnote-224242997
Ref: Documentation<27>-Footnote-234243053
Ref: Documentation<27>-Footnote-244243119
Ref: Documentation<27>-Footnote-254243185
Ref: Documentation<27>-Footnote-264243251
Ref: Documentation<27>-Footnote-274243317
Node: Tests<27>4243383
Ref: whatsnew/changelog id3784243494
Ref: 1b584243494
Ref: Tests<27>-Footnote-14248877
Ref: Tests<27>-Footnote-24248932
Ref: Tests<27>-Footnote-34248987
Ref: Tests<27>-Footnote-44249042
Ref: Tests<27>-Footnote-54249097
Ref: Tests<27>-Footnote-64249184
Ref: Tests<27>-Footnote-74249239
Ref: Tests<27>-Footnote-84249294
Ref: Tests<27>-Footnote-94249349
Ref: Tests<27>-Footnote-104249404
Ref: Tests<27>-Footnote-114249460
Ref: Tests<27>-Footnote-124249516
Ref: Tests<27>-Footnote-134249572
Ref: Tests<27>-Footnote-144249628
Ref: Tests<27>-Footnote-154249684
Ref: Tests<27>-Footnote-164249740
Ref: Tests<27>-Footnote-174249796
Ref: Tests<27>-Footnote-184249852
Ref: Tests<27>-Footnote-194249908
Ref: Tests<27>-Footnote-204249964
Ref: Tests<27>-Footnote-214250020
Ref: Tests<27>-Footnote-224250076
Ref: Tests<27>-Footnote-234250132
Ref: Tests<27>-Footnote-244250188
Ref: Tests<27>-Footnote-254250244
Ref: Tests<27>-Footnote-264250300
Ref: Tests<27>-Footnote-274250356
Ref: Tests<27>-Footnote-284250412
Ref: Tests<27>-Footnote-294250468
Ref: Tests<27>-Footnote-304250524
Ref: Tests<27>-Footnote-314250580
Ref: Tests<27>-Footnote-324250636
Ref: Tests<27>-Footnote-334250692
Ref: Tests<27>-Footnote-344250748
Ref: Tests<27>-Footnote-354250804
Ref: Tests<27>-Footnote-364250860
Node: Build<32>4250926
Ref: whatsnew/changelog id3794251031
Ref: 1b5c4251031
Ref: Build<32>-Footnote-14256516
Ref: Build<32>-Footnote-24256571
Ref: Build<32>-Footnote-34256626
Ref: Build<32>-Footnote-44256681
Ref: Build<32>-Footnote-54256736
Ref: Build<32>-Footnote-64256791
Ref: Build<32>-Footnote-74256846
Ref: Build<32>-Footnote-84256901
Ref: Build<32>-Footnote-94256956
Ref: Build<32>-Footnote-104257011
Ref: Build<32>-Footnote-114257067
Ref: Build<32>-Footnote-124257123
Ref: Build<32>-Footnote-134257179
Ref: Build<32>-Footnote-144257235
Ref: Build<32>-Footnote-154257291
Ref: Build<32>-Footnote-164257347
Ref: Build<32>-Footnote-174257390
Ref: Build<32>-Footnote-184257446
Ref: Build<32>-Footnote-194257502
Ref: Build<32>-Footnote-204257558
Ref: Build<32>-Footnote-214257614
Ref: Build<32>-Footnote-224257670
Ref: Build<32>-Footnote-234257726
Ref: Build<32>-Footnote-244257782
Ref: Build<32>-Footnote-254257838
Ref: Build<32>-Footnote-264257894
Ref: Build<32>-Footnote-274257950
Ref: Build<32>-Footnote-284258006
Ref: Build<32>-Footnote-294258062
Ref: Build<32>-Footnote-304258118
Ref: Build<32>-Footnote-314258174
Ref: Build<32>-Footnote-324258217
Ref: Build<32>-Footnote-334258273
Ref: Build<32>-Footnote-344258329
Ref: Build<32>-Footnote-354258385
Ref: Build<32>-Footnote-364258441
Node: Windows<28>4258507
Ref: whatsnew/changelog id3804258612
Ref: 1b5d4258612
Ref: Windows<28>-Footnote-14263025
Ref: Windows<28>-Footnote-24263080
Ref: Windows<28>-Footnote-34263135
Ref: Windows<28>-Footnote-44263190
Ref: Windows<28>-Footnote-54263245
Ref: Windows<28>-Footnote-64263300
Ref: Windows<28>-Footnote-74263355
Ref: Windows<28>-Footnote-84263410
Ref: Windows<28>-Footnote-94263465
Ref: Windows<28>-Footnote-104263520
Ref: Windows<28>-Footnote-114263576
Ref: Windows<28>-Footnote-124263632
Ref: Windows<28>-Footnote-134263688
Ref: Windows<28>-Footnote-144263744
Ref: Windows<28>-Footnote-154263800
Ref: Windows<28>-Footnote-164263856
Ref: Windows<28>-Footnote-174263912
Ref: Windows<28>-Footnote-184263968
Ref: Windows<28>-Footnote-194264024
Ref: Windows<28>-Footnote-204264080
Ref: Windows<28>-Footnote-214264136
Ref: Windows<28>-Footnote-224264192
Ref: Windows<28>-Footnote-234264248
Ref: Windows<28>-Footnote-244264304
Ref: Windows<28>-Footnote-254264360
Ref: Windows<28>-Footnote-264264416
Ref: Windows<28>-Footnote-274264482
Ref: Windows<28>-Footnote-284264538
Ref: Windows<28>-Footnote-294264604
Node: macOS<19>4264670
Ref: whatsnew/changelog id3814264774
Ref: 1b5f4264774
Ref: macOS<19>-Footnote-14265324
Node: IDLE<15>4265379
Ref: whatsnew/changelog id3824265487
Ref: 1b604265487
Ref: IDLE<15>-Footnote-14266402
Ref: IDLE<15>-Footnote-24266457
Ref: IDLE<15>-Footnote-34266512
Ref: IDLE<15>-Footnote-44266567
Ref: IDLE<15>-Footnote-54266622
Ref: IDLE<15>-Footnote-64266677
Ref: IDLE<15>-Footnote-74266732
Node: Tools/Demos<24>4266787
Ref: whatsnew/changelog id3834266895
Ref: 1b614266895
Ref: Tools/Demos<24>-Footnote-14268406
Ref: Tools/Demos<24>-Footnote-24268461
Ref: Tools/Demos<24>-Footnote-34268516
Ref: Tools/Demos<24>-Footnote-44268564
Ref: Tools/Demos<24>-Footnote-54268619
Ref: Tools/Demos<24>-Footnote-64268667
Ref: Tools/Demos<24>-Footnote-74268722
Ref: Tools/Demos<24>-Footnote-84268777
Ref: Tools/Demos<24>-Footnote-94268832
Ref: Tools/Demos<24>-Footnote-104268887
Ref: Tools/Demos<24>-Footnote-114268943
Ref: Tools/Demos<24>-Footnote-124268999
Node: C API<29>4269055
Ref: whatsnew/changelog id3854269146
Ref: 1b624269146
Ref: C API<29>-Footnote-14276690
Ref: C API<29>-Footnote-24276745
Ref: C API<29>-Footnote-34276800
Ref: C API<29>-Footnote-44276855
Ref: C API<29>-Footnote-54276910
Ref: C API<29>-Footnote-64276965
Ref: C API<29>-Footnote-74277020
Ref: C API<29>-Footnote-84277075
Ref: C API<29>-Footnote-94277130
Ref: C API<29>-Footnote-104277185
Ref: C API<29>-Footnote-114277241
Ref: C API<29>-Footnote-124277297
Ref: C API<29>-Footnote-134277353
Ref: C API<29>-Footnote-144277409
Ref: C API<29>-Footnote-154277465
Ref: C API<29>-Footnote-164277521
Ref: C API<29>-Footnote-174277577
Ref: C API<29>-Footnote-184277633
Ref: C API<29>-Footnote-194277689
Ref: C API<29>-Footnote-204277745
Ref: C API<29>-Footnote-214277801
Ref: C API<29>-Footnote-224277857
Ref: C API<29>-Footnote-234277913
Ref: C API<29>-Footnote-244277969
Ref: C API<29>-Footnote-254278025
Ref: C API<29>-Footnote-264278081
Ref: C API<29>-Footnote-274278137
Ref: C API<29>-Footnote-284278193
Ref: C API<29>-Footnote-294278249
Ref: C API<29>-Footnote-304278305
Ref: C API<29>-Footnote-314278361
Ref: C API<29>-Footnote-324278417
Ref: C API<29>-Footnote-334278473
Ref: C API<29>-Footnote-344278529
Node: Python 3 11 0 beta 14278595
Ref: whatsnew/changelog python-3-11-0-beta-14278721
Ref: 1b644278721
Node: Security<28>4279216
Ref: whatsnew/changelog id3864279315
Ref: 1b654279315
Ref: Security<28>-Footnote-14279614
Node: Core and Builtins<83>4279669
Ref: whatsnew/changelog id3874279788
Ref: 1b664279788
Ref: Core and Builtins<83>-Footnote-14286446
Ref: Core and Builtins<83>-Footnote-24286501
Ref: Core and Builtins<83>-Footnote-34286566
Ref: Core and Builtins<83>-Footnote-44286621
Ref: Core and Builtins<83>-Footnote-54286686
Ref: Core and Builtins<83>-Footnote-64286741
Ref: Core and Builtins<83>-Footnote-74286796
Ref: Core and Builtins<83>-Footnote-84286851
Ref: Core and Builtins<83>-Footnote-94286906
Ref: Core and Builtins<83>-Footnote-104286961
Ref: Core and Builtins<83>-Footnote-114287017
Ref: Core and Builtins<83>-Footnote-124287073
Ref: Core and Builtins<83>-Footnote-134287129
Ref: Core and Builtins<83>-Footnote-144287185
Ref: Core and Builtins<83>-Footnote-154287228
Ref: Core and Builtins<83>-Footnote-164287284
Ref: Core and Builtins<83>-Footnote-174287340
Ref: Core and Builtins<83>-Footnote-184287396
Ref: Core and Builtins<83>-Footnote-194287452
Ref: Core and Builtins<83>-Footnote-204287508
Ref: Core and Builtins<83>-Footnote-214287564
Ref: Core and Builtins<83>-Footnote-224287630
Ref: Core and Builtins<83>-Footnote-234287686
Ref: Core and Builtins<83>-Footnote-244287742
Ref: Core and Builtins<83>-Footnote-254287798
Ref: Core and Builtins<83>-Footnote-264287854
Ref: Core and Builtins<83>-Footnote-274287910
Ref: Core and Builtins<83>-Footnote-284287966
Ref: Core and Builtins<83>-Footnote-294288022
Ref: Core and Builtins<83>-Footnote-304288078
Ref: Core and Builtins<83>-Footnote-314288134
Ref: Core and Builtins<83>-Footnote-324288190
Ref: Core and Builtins<83>-Footnote-334288233
Ref: Core and Builtins<83>-Footnote-344288289
Ref: Core and Builtins<83>-Footnote-354288345
Ref: Core and Builtins<83>-Footnote-364288401
Ref: Core and Builtins<83>-Footnote-374288467
Ref: Core and Builtins<83>-Footnote-384288523
Ref: Core and Builtins<83>-Footnote-394288579
Ref: Core and Builtins<83>-Footnote-404288645
Node: Library<87>4288711
Ref: whatsnew/changelog id3884288839
Ref: 1b694288839
Ref: Library<87>-Footnote-14289306
Node: Core and Builtins<84>4289371
Ref: whatsnew/changelog id3894289487
Ref: 1b6a4289487
Ref: Core and Builtins<84>-Footnote-14291262
Ref: Core and Builtins<84>-Footnote-24291327
Ref: Core and Builtins<84>-Footnote-34291392
Ref: Core and Builtins<84>-Footnote-44291457
Ref: Core and Builtins<84>-Footnote-54291522
Ref: Core and Builtins<84>-Footnote-64291587
Ref: Core and Builtins<84>-Footnote-74291652
Ref: Core and Builtins<84>-Footnote-84291717
Ref: Core and Builtins<84>-Footnote-94291782
Node: Build<33>4291847
Ref: whatsnew/changelog id3904291973
Ref: 1b6e4291973
Ref: Build<33>-Footnote-14292100
Node: Core and Builtins<85>4292165
Ref: whatsnew/changelog id3914292281
Ref: 1b6f4292281
Ref: Core and Builtins<85>-Footnote-14293105
Ref: Core and Builtins<85>-Footnote-24293170
Ref: Core and Builtins<85>-Footnote-34293235
Node: Library<88>4293300
Ref: whatsnew/changelog id3924293424
Ref: 1b704293424
Ref: Library<88>-Footnote-14310975
Ref: Library<88>-Footnote-24311030
Ref: Library<88>-Footnote-34311085
Ref: Library<88>-Footnote-44311140
Ref: Library<88>-Footnote-54311195
Ref: Library<88>-Footnote-64311250
Ref: Library<88>-Footnote-74311305
Ref: Library<88>-Footnote-84311360
Ref: Library<88>-Footnote-94311415
Ref: Library<88>-Footnote-104311470
Ref: Library<88>-Footnote-114311526
Ref: Library<88>-Footnote-124311582
Ref: Library<88>-Footnote-134311638
Ref: Library<88>-Footnote-144311694
Ref: Library<88>-Footnote-154311750
Ref: Library<88>-Footnote-164311806
Ref: Library<88>-Footnote-174311862
Ref: Library<88>-Footnote-184311918
Ref: Library<88>-Footnote-194311974
Ref: Library<88>-Footnote-204312030
Ref: Library<88>-Footnote-214312086
Ref: Library<88>-Footnote-224312142
Ref: Library<88>-Footnote-234312198
Ref: Library<88>-Footnote-244312254
Ref: Library<88>-Footnote-254312320
Ref: Library<88>-Footnote-264312376
Ref: Library<88>-Footnote-274312432
Ref: Library<88>-Footnote-284312475
Ref: Library<88>-Footnote-294312531
Ref: Library<88>-Footnote-304312587
Ref: Library<88>-Footnote-314312643
Ref: Library<88>-Footnote-324312699
Ref: Library<88>-Footnote-334312742
Ref: Library<88>-Footnote-344312798
Ref: Library<88>-Footnote-354312854
Ref: Library<88>-Footnote-364312910
Ref: Library<88>-Footnote-374312966
Ref: Library<88>-Footnote-384313022
Ref: Library<88>-Footnote-394313078
Ref: Library<88>-Footnote-404313134
Ref: Library<88>-Footnote-414313190
Ref: Library<88>-Footnote-424313246
Ref: Library<88>-Footnote-434313302
Ref: Library<88>-Footnote-444313358
Ref: Library<88>-Footnote-454313414
Ref: Library<88>-Footnote-464313470
Ref: Library<88>-Footnote-474313526
Ref: Library<88>-Footnote-484313582
Ref: Library<88>-Footnote-494313638
Ref: Library<88>-Footnote-504313694
Ref: Library<88>-Footnote-514313750
Ref: Library<88>-Footnote-524313806
Ref: Library<88>-Footnote-534313862
Ref: Library<88>-Footnote-544313918
Ref: Library<88>-Footnote-554313974
Ref: Library<88>-Footnote-564314030
Ref: Library<88>-Footnote-574314096
Ref: Library<88>-Footnote-584314152
Ref: Library<88>-Footnote-594314208
Ref: Library<88>-Footnote-604314264
Ref: Library<88>-Footnote-614314320
Ref: Library<88>-Footnote-624314376
Ref: Library<88>-Footnote-634314432
Ref: Library<88>-Footnote-644314488
Ref: Library<88>-Footnote-654314544
Ref: Library<88>-Footnote-664314600
Ref: Library<88>-Footnote-674314643
Ref: Library<88>-Footnote-684314699
Ref: Library<88>-Footnote-694314755
Ref: Library<88>-Footnote-704314811
Ref: Library<88>-Footnote-714314867
Ref: Library<88>-Footnote-724314923
Ref: Library<88>-Footnote-734314979
Ref: Library<88>-Footnote-744315035
Ref: Library<88>-Footnote-754315091
Ref: Library<88>-Footnote-764315157
Ref: Library<88>-Footnote-774315213
Ref: Library<88>-Footnote-784315269
Ref: Library<88>-Footnote-794315325
Ref: Library<88>-Footnote-804315391
Ref: Library<88>-Footnote-814315457
Ref: Library<88>-Footnote-824315500
Ref: Library<88>-Footnote-834315566
Ref: Library<88>-Footnote-844315632
Ref: Library<88>-Footnote-854315698
Ref: Library<88>-Footnote-864315764
Ref: Library<88>-Footnote-874315830
Ref: Library<88>-Footnote-884315896
Ref: Library<88>-Footnote-894315962
Ref: Library<88>-Footnote-904316028
Ref: Library<88>-Footnote-914316094
Ref: Library<88>-Footnote-924316160
Ref: Library<88>-Footnote-934316226
Ref: Library<88>-Footnote-944316292
Ref: Library<88>-Footnote-954316358
Ref: Library<88>-Footnote-964316424
Ref: Library<88>-Footnote-974316490
Ref: Library<88>-Footnote-984316556
Ref: Library<88>-Footnote-994316622
Ref: Library<88>-Footnote-1004316688
Ref: Library<88>-Footnote-1014316755
Ref: Library<88>-Footnote-1024316822
Ref: Library<88>-Footnote-1034316889
Ref: Library<88>-Footnote-1044316956
Ref: Library<88>-Footnote-1054317023
Ref: Library<88>-Footnote-1064317090
Ref: Library<88>-Footnote-1074317157
Ref: Library<88>-Footnote-1084317224
Ref: Library<88>-Footnote-1094317291
Ref: Library<88>-Footnote-1104317358
Ref: Library<88>-Footnote-1114317425
Ref: Library<88>-Footnote-1124317492
Ref: Library<88>-Footnote-1134317559
Ref: Library<88>-Footnote-1144317626
Ref: Library<88>-Footnote-1154317693
Ref: Library<88>-Footnote-1164317760
Ref: Library<88>-Footnote-1174317827
Ref: Library<88>-Footnote-1184317894
Ref: Library<88>-Footnote-1194317961
Ref: Library<88>-Footnote-1204318028
Node: Documentation<28>4318095
Ref: whatsnew/changelog id3934318207
Ref: 1b7d4318207
Ref: Documentation<28>-Footnote-14319763
Ref: Documentation<28>-Footnote-24319818
Ref: Documentation<28>-Footnote-34319873
Ref: Documentation<28>-Footnote-44319928
Ref: Documentation<28>-Footnote-54319983
Ref: Documentation<28>-Footnote-64320048
Ref: Documentation<28>-Footnote-74320113
Ref: Documentation<28>-Footnote-84320178
Ref: Documentation<28>-Footnote-94320243
Ref: Documentation<28>-Footnote-104320285
Ref: Documentation<28>-Footnote-114320328
Ref: Documentation<28>-Footnote-124320394
Ref: Documentation<28>-Footnote-134320460
Ref: Documentation<28>-Footnote-144320525
Node: Tests<28>4320591
Ref: whatsnew/changelog id3944320701
Ref: 1b804320701
Ref: Tests<28>-Footnote-14322043
Ref: Tests<28>-Footnote-24322098
Ref: Tests<28>-Footnote-34322153
Ref: Tests<28>-Footnote-44322208
Ref: Tests<28>-Footnote-54322263
Ref: Tests<28>-Footnote-64322318
Ref: Tests<28>-Footnote-74322383
Ref: Tests<28>-Footnote-84322448
Node: Build<34>4322513
Ref: whatsnew/changelog id3954322617
Ref: 1b834322617
Ref: Build<34>-Footnote-14323246
Ref: Build<34>-Footnote-24323301
Ref: Build<34>-Footnote-34323356
Ref: Build<34>-Footnote-44323421
Node: Windows<29>4323486
Ref: whatsnew/changelog id3964323590
Ref: 1b844323590
Ref: Windows<29>-Footnote-14324216
Ref: Windows<29>-Footnote-24324281
Ref: Windows<29>-Footnote-34324346
Ref: Windows<29>-Footnote-44324411
Ref: Windows<29>-Footnote-54324476
Node: macOS<20>4324541
Ref: whatsnew/changelog id3974324651
Ref: 1b854324651
Ref: macOS<20>-Footnote-14324783
Node: Tools/Demos<25>4324848
Ref: whatsnew/changelog id3984324956
Ref: 1b864324956
Ref: Tools/Demos<25>-Footnote-14325515
Ref: Tools/Demos<25>-Footnote-24325570
Ref: Tools/Demos<25>-Footnote-34325625
Node: C API<30>4325680
Ref: whatsnew/changelog id3994325770
Ref: 1b874325770
Ref: C API<30>-Footnote-14327931
Ref: C API<30>-Footnote-24327986
Ref: C API<30>-Footnote-34328041
Ref: C API<30>-Footnote-44328096
Ref: C API<30>-Footnote-54328151
Ref: C API<30>-Footnote-64328206
Ref: C API<30>-Footnote-74328248
Ref: C API<30>-Footnote-84328303
Ref: C API<30>-Footnote-94328358
Ref: C API<30>-Footnote-104328423
Ref: C API<30>-Footnote-114328489
Ref: C API<30>-Footnote-124328555
Ref: C API<30>-Footnote-134328621
Node: Python 3 11 0 alpha 74328687
Ref: whatsnew/changelog python-3-11-0-alpha-74328813
Ref: 1b8b4328813
Node: Core and Builtins<86>4329288
Ref: whatsnew/changelog id4004329387
Ref: 1b8c4329387
Ref: Core and Builtins<86>-Footnote-14332666
Ref: Core and Builtins<86>-Footnote-24332731
Ref: Core and Builtins<86>-Footnote-34332796
Ref: Core and Builtins<86>-Footnote-44332861
Ref: Core and Builtins<86>-Footnote-54332926
Ref: Core and Builtins<86>-Footnote-64332991
Ref: Core and Builtins<86>-Footnote-74333056
Ref: Core and Builtins<86>-Footnote-84333121
Ref: Core and Builtins<86>-Footnote-94333186
Ref: Core and Builtins<86>-Footnote-104333251
Ref: Core and Builtins<86>-Footnote-114333317
Ref: Core and Builtins<86>-Footnote-124333383
Ref: Core and Builtins<86>-Footnote-134333449
Ref: Core and Builtins<86>-Footnote-144333515
Ref: Core and Builtins<86>-Footnote-154333581
Ref: Core and Builtins<86>-Footnote-164333647
Ref: Core and Builtins<86>-Footnote-174333713
Node: Library<89>4333779
Ref: whatsnew/changelog id4014333908
Ref: 1b8e4333908
Ref: Library<89>-Footnote-14334191
Node: Core and Builtins<87>4334256
Ref: whatsnew/changelog id4024334375
Ref: 1b8f4334375
Ref: Core and Builtins<87>-Footnote-14335226
Ref: Core and Builtins<87>-Footnote-24335291
Ref: Core and Builtins<87>-Footnote-34335356
Ref: Core and Builtins<87>-Footnote-44335421
Ref: Core and Builtins<87>-Footnote-54335486
Node: Library<90>4335551
Ref: whatsnew/changelog id4034335680
Ref: 1b904335680
Ref: Library<90>-Footnote-14335891
Node: Core and Builtins<88>4335956
Ref: whatsnew/changelog id4044336075
Ref: 1b924336075
Ref: Core and Builtins<88>-Footnote-14337340
Ref: Core and Builtins<88>-Footnote-24337405
Ref: Core and Builtins<88>-Footnote-34337470
Ref: Core and Builtins<88>-Footnote-44337535
Ref: Core and Builtins<88>-Footnote-54337600
Ref: Core and Builtins<88>-Footnote-64337665
Ref: Core and Builtins<88>-Footnote-74337730
Ref: Core and Builtins<88>-Footnote-84337795
Ref: Core and Builtins<88>-Footnote-94337860
Node: Library<91>4337925
Ref: whatsnew/changelog id4054338050
Ref: 1b944338050
Ref: Library<91>-Footnote-14352250
Ref: Library<91>-Footnote-24352315
Ref: Library<91>-Footnote-34352380
Ref: Library<91>-Footnote-44352445
Ref: Library<91>-Footnote-54352510
Ref: Library<91>-Footnote-64352575
Ref: Library<91>-Footnote-74352639
Ref: Library<91>-Footnote-84352704
Ref: Library<91>-Footnote-94352769
Ref: Library<91>-Footnote-104352834
Ref: Library<91>-Footnote-114352900
Ref: Library<91>-Footnote-124352966
Ref: Library<91>-Footnote-134353032
Ref: Library<91>-Footnote-144353098
Ref: Library<91>-Footnote-154353141
Ref: Library<91>-Footnote-164353207
Ref: Library<91>-Footnote-174353273
Ref: Library<91>-Footnote-184353339
Ref: Library<91>-Footnote-194353382
Ref: Library<91>-Footnote-204353448
Ref: Library<91>-Footnote-214353514
Ref: Library<91>-Footnote-224353580
Ref: Library<91>-Footnote-234353623
Ref: Library<91>-Footnote-244353689
Ref: Library<91>-Footnote-254353755
Ref: Library<91>-Footnote-264353821
Ref: Library<91>-Footnote-274353887
Ref: Library<91>-Footnote-284353953
Ref: Library<91>-Footnote-294354019
Ref: Library<91>-Footnote-304354086
Ref: Library<91>-Footnote-314354152
Ref: Library<91>-Footnote-324354218
Ref: Library<91>-Footnote-334354284
Ref: Library<91>-Footnote-344354350
Ref: Library<91>-Footnote-354354393
Ref: Library<91>-Footnote-364354459
Ref: Library<91>-Footnote-374354525
Ref: Library<91>-Footnote-384354590
Ref: Library<91>-Footnote-394354656
Ref: Library<91>-Footnote-404354722
Ref: Library<91>-Footnote-414354788
Ref: Library<91>-Footnote-424354854
Ref: Library<91>-Footnote-434354897
Ref: Library<91>-Footnote-444354963
Ref: Library<91>-Footnote-454355029
Ref: Library<91>-Footnote-464355095
Ref: Library<91>-Footnote-474355161
Ref: Library<91>-Footnote-484355227
Ref: Library<91>-Footnote-494355293
Ref: Library<91>-Footnote-504355359
Ref: Library<91>-Footnote-514355425
Ref: Library<91>-Footnote-524355491
Ref: Library<91>-Footnote-534355557
Ref: Library<91>-Footnote-544355623
Ref: Library<91>-Footnote-554355689
Ref: Library<91>-Footnote-564355755
Ref: Library<91>-Footnote-574355821
Ref: Library<91>-Footnote-584355887
Ref: Library<91>-Footnote-594355953
Ref: Library<91>-Footnote-604355996
Ref: Library<91>-Footnote-614356063
Ref: Library<91>-Footnote-624356129
Ref: Library<91>-Footnote-634356195
Ref: Library<91>-Footnote-644356261
Ref: Library<91>-Footnote-654356327
Ref: Library<91>-Footnote-664356393
Ref: Library<91>-Footnote-674356459
Ref: Library<91>-Footnote-684356525
Ref: Library<91>-Footnote-694356591
Ref: Library<91>-Footnote-704356657
Ref: Library<91>-Footnote-714356723
Ref: Library<91>-Footnote-724356789
Ref: Library<91>-Footnote-734356855
Ref: Library<91>-Footnote-744356921
Ref: Library<91>-Footnote-754356987
Ref: Library<91>-Footnote-764357053
Ref: Library<91>-Footnote-774357119
Ref: Library<91>-Footnote-784357185
Ref: Library<91>-Footnote-794357251
Ref: Library<91>-Footnote-804357317
Ref: Library<91>-Footnote-814357383
Ref: Library<91>-Footnote-824357449
Ref: Library<91>-Footnote-834357515
Ref: Library<91>-Footnote-844357558
Ref: Library<91>-Footnote-854357624
Ref: Library<91>-Footnote-864357690
Ref: Library<91>-Footnote-874357756
Ref: Library<91>-Footnote-884357822
Node: Documentation<29>4357888
Ref: whatsnew/changelog id4064358001
Ref: 1ba14358001
Ref: Documentation<29>-Footnote-14359137
Ref: Documentation<29>-Footnote-24359202
Ref: Documentation<29>-Footnote-34359267
Ref: Documentation<29>-Footnote-44359309
Ref: Documentation<29>-Footnote-54359374
Ref: Documentation<29>-Footnote-64359439
Ref: Documentation<29>-Footnote-74359504
Ref: Documentation<29>-Footnote-84359569
Node: Tests<29>4359634
Ref: whatsnew/changelog id4074359745
Ref: 1ba44359745
Ref: Tests<29>-Footnote-14360714
Ref: Tests<29>-Footnote-24360779
Ref: Tests<29>-Footnote-34360844
Ref: Tests<29>-Footnote-44360909
Ref: Tests<29>-Footnote-54360974
Ref: Tests<29>-Footnote-64361039
Ref: Tests<29>-Footnote-74361104
Ref: Tests<29>-Footnote-84361169
Node: Build<35>4361211
Ref: whatsnew/changelog id4084361316
Ref: 1ba54361316
Ref: Build<35>-Footnote-14362604
Ref: Build<35>-Footnote-24362669
Ref: Build<35>-Footnote-34362734
Ref: Build<35>-Footnote-44362799
Ref: Build<35>-Footnote-54362864
Ref: Build<35>-Footnote-64362929
Ref: Build<35>-Footnote-74362994
Ref: Build<35>-Footnote-84363059
Ref: Build<35>-Footnote-94363124
Node: Windows<30>4363189
Ref: whatsnew/changelog id4094363294
Ref: 1ba74363294
Ref: Windows<30>-Footnote-14364482
Ref: Windows<30>-Footnote-24364547
Ref: Windows<30>-Footnote-34364603
Ref: Windows<30>-Footnote-44364668
Ref: Windows<30>-Footnote-54364733
Ref: Windows<30>-Footnote-64364775
Ref: Windows<30>-Footnote-74364840
Ref: Windows<30>-Footnote-84364905
Ref: Windows<30>-Footnote-94364970
Ref: Windows<30>-Footnote-104365025
Ref: Windows<30>-Footnote-114365082
Ref: Windows<30>-Footnote-124365148
Node: macOS<21>4365205
Ref: whatsnew/changelog id4104365316
Ref: 1ba84365316
Ref: macOS<21>-Footnote-14365654
Ref: macOS<21>-Footnote-24365719
Node: Tools/Demos<26>4365784
Ref: whatsnew/changelog id4114365893
Ref: 1ba94365893
Ref: Tools/Demos<26>-Footnote-14366100
Node: C API<31>4366165
Ref: whatsnew/changelog id4124366256
Ref: 1baa4366256
Ref: C API<31>-Footnote-14368515
Ref: C API<31>-Footnote-24368580
Ref: C API<31>-Footnote-34368645
Ref: C API<31>-Footnote-44368710
Ref: C API<31>-Footnote-54368775
Ref: C API<31>-Footnote-64368840
Ref: C API<31>-Footnote-74368905
Ref: C API<31>-Footnote-84368970
Node: Python 3 11 0 alpha 64369035
Ref: whatsnew/changelog python-3-11-0-alpha-64369162
Ref: 1bad4369162
Node: Core and Builtins<89>4369671
Ref: whatsnew/changelog id4134369770
Ref: 1bae4369770
Ref: Core and Builtins<89>-Footnote-14373143
Ref: Core and Builtins<89>-Footnote-24373208
Ref: Core and Builtins<89>-Footnote-34373273
Ref: Core and Builtins<89>-Footnote-44373338
Ref: Core and Builtins<89>-Footnote-54373403
Ref: Core and Builtins<89>-Footnote-64373468
Ref: Core and Builtins<89>-Footnote-74373533
Ref: Core and Builtins<89>-Footnote-84373598
Ref: Core and Builtins<89>-Footnote-94373663
Ref: Core and Builtins<89>-Footnote-104373728
Ref: Core and Builtins<89>-Footnote-114373794
Ref: Core and Builtins<89>-Footnote-124373860
Ref: Core and Builtins<89>-Footnote-134373926
Ref: Core and Builtins<89>-Footnote-144373992
Ref: Core and Builtins<89>-Footnote-154374058
Ref: Core and Builtins<89>-Footnote-164374124
Ref: Core and Builtins<89>-Footnote-174374190
Ref: Core and Builtins<89>-Footnote-184374256
Ref: Core and Builtins<89>-Footnote-194374322
Ref: Core and Builtins<89>-Footnote-204374388
Ref: Core and Builtins<89>-Footnote-214374454
Ref: Core and Builtins<89>-Footnote-224374520
Ref: Core and Builtins<89>-Footnote-234374586
Ref: Core and Builtins<89>-Footnote-244374652
Ref: Core and Builtins<89>-Footnote-254374718
Ref: Core and Builtins<89>-Footnote-264374784
Node: Library<92>4374850
Ref: whatsnew/changelog id4144374979
Ref: 1bb24374979
Ref: Library<92>-Footnote-14375112
Node: Core and Builtins<90>4375177
Ref: whatsnew/changelog id4154375296
Ref: 1bb34375296
Ref: Core and Builtins<90>-Footnote-14377399
Ref: Core and Builtins<90>-Footnote-24377464
Ref: Core and Builtins<90>-Footnote-34377529
Ref: Core and Builtins<90>-Footnote-44377594
Ref: Core and Builtins<90>-Footnote-54377659
Ref: Core and Builtins<90>-Footnote-64377724
Ref: Core and Builtins<90>-Footnote-74377789
Ref: Core and Builtins<90>-Footnote-84377854
Ref: Core and Builtins<90>-Footnote-94377919
Ref: Core and Builtins<90>-Footnote-104377984
Ref: Core and Builtins<90>-Footnote-114378050
Node: Library<93>4378116
Ref: whatsnew/changelog id4164378245
Ref: 1bb44378245
Ref: Library<93>-Footnote-14378505
Node: Core and Builtins<91>4378570
Ref: whatsnew/changelog id4174378689
Ref: 1bb54378689
Ref: Core and Builtins<91>-Footnote-14379291
Ref: Core and Builtins<91>-Footnote-24379356
Ref: Core and Builtins<91>-Footnote-34379421
Ref: Core and Builtins<91>-Footnote-44379486
Node: Library<94>4379551
Ref: whatsnew/changelog id4184379680
Ref: 1bb64379680
Ref: Library<94>-Footnote-14379973
Ref: Library<94>-Footnote-24380038
Node: Core and Builtins<92>4380103
Ref: whatsnew/changelog id4194380222
Ref: 1bb74380222
Ref: Core and Builtins<92>-Footnote-14380921
Ref: Core and Builtins<92>-Footnote-24380986
Ref: Core and Builtins<92>-Footnote-34381051
Node: Library<95>4381116
Ref: whatsnew/changelog id4204381241
Ref: 1bba4381241
Ref: Library<95>-Footnote-14389466
Ref: Library<95>-Footnote-24389531
Ref: Library<95>-Footnote-34389596
Ref: Library<95>-Footnote-44389661
Ref: Library<95>-Footnote-54389726
Ref: Library<95>-Footnote-64389791
Ref: Library<95>-Footnote-74389856
Ref: Library<95>-Footnote-84389921
Ref: Library<95>-Footnote-94389986
Ref: Library<95>-Footnote-104390051
Ref: Library<95>-Footnote-114390117
Ref: Library<95>-Footnote-124390183
Ref: Library<95>-Footnote-134390249
Ref: Library<95>-Footnote-144390315
Ref: Library<95>-Footnote-154390381
Ref: Library<95>-Footnote-164390447
Ref: Library<95>-Footnote-174390513
Ref: Library<95>-Footnote-184390579
Ref: Library<95>-Footnote-194390645
Ref: Library<95>-Footnote-204390711
Ref: Library<95>-Footnote-214390777
Ref: Library<95>-Footnote-224390843
Ref: Library<95>-Footnote-234390909
Ref: Library<95>-Footnote-244390975
Ref: Library<95>-Footnote-254391041
Ref: Library<95>-Footnote-264391107
Ref: Library<95>-Footnote-274391173
Ref: Library<95>-Footnote-284391239
Ref: Library<95>-Footnote-294391305
Ref: Library<95>-Footnote-304391371
Ref: Library<95>-Footnote-314391437
Ref: Library<95>-Footnote-324391503
Ref: Library<95>-Footnote-334391569
Ref: Library<95>-Footnote-344391635
Ref: Library<95>-Footnote-354391678
Ref: Library<95>-Footnote-364391744
Ref: Library<95>-Footnote-374391810
Ref: Library<95>-Footnote-384391876
Ref: Library<95>-Footnote-394391942
Ref: Library<95>-Footnote-404392008
Ref: Library<95>-Footnote-414392074
Ref: Library<95>-Footnote-424392140
Ref: Library<95>-Footnote-434392206
Ref: Library<95>-Footnote-444392272
Ref: Library<95>-Footnote-454392338
Ref: Library<95>-Footnote-464392404
Ref: Library<95>-Footnote-474392470
Ref: Library<95>-Footnote-484392536
Node: Documentation<30>4392602
Ref: whatsnew/changelog id4214392715
Ref: 1bc64392715
Ref: Documentation<30>-Footnote-14392934
Node: Tests<30>4392999
Ref: whatsnew/changelog id4224393110
Ref: 1bc74393110
Ref: Tests<30>-Footnote-14394081
Ref: Tests<30>-Footnote-24394146
Ref: Tests<30>-Footnote-34394211
Ref: Tests<30>-Footnote-44394276
Ref: Tests<30>-Footnote-54394341
Node: Build<36>4394406
Ref: whatsnew/changelog id4234394511
Ref: 1bc84394511
Ref: Build<36>-Footnote-14395941
Ref: Build<36>-Footnote-24396006
Ref: Build<36>-Footnote-34396071
Ref: Build<36>-Footnote-44396136
Ref: Build<36>-Footnote-54396201
Ref: Build<36>-Footnote-64396266
Ref: Build<36>-Footnote-74396331
Node: Windows<31>4396396
Ref: whatsnew/changelog id4244396500
Ref: 1bc94396500
Ref: Windows<31>-Footnote-14397160
Ref: Windows<31>-Footnote-24397225
Ref: Windows<31>-Footnote-34397290
Node: IDLE<16>4397355
Ref: whatsnew/changelog id4254397459
Ref: 1bca4397459
Ref: IDLE<16>-Footnote-14397741
Ref: IDLE<16>-Footnote-24397806
Node: C API<32>4397871
Ref: whatsnew/changelog id4264397955
Ref: 1bcb4397955
Ref: C API<32>-Footnote-14398904
Ref: C API<32>-Footnote-24398969
Ref: C API<32>-Footnote-34399034
Ref: C API<32>-Footnote-44399099
Ref: C API<32>-Footnote-54399164
Node: Python 3 11 0 alpha 54399229
Ref: whatsnew/changelog python-3-11-0-alpha-54399356
Ref: 1bcc4399356
Node: Core and Builtins<93>4399837
Ref: whatsnew/changelog id4274399936
Ref: 1bcd4399936
Ref: Core and Builtins<93>-Footnote-14403870
Ref: Core and Builtins<93>-Footnote-24403935
Ref: Core and Builtins<93>-Footnote-34404000
Ref: Core and Builtins<93>-Footnote-44404065
Ref: Core and Builtins<93>-Footnote-54404130
Ref: Core and Builtins<93>-Footnote-64404195
Ref: Core and Builtins<93>-Footnote-74404260
Ref: Core and Builtins<93>-Footnote-84404325
Ref: Core and Builtins<93>-Footnote-94404390
Ref: Core and Builtins<93>-Footnote-104404455
Ref: Core and Builtins<93>-Footnote-114404521
Ref: Core and Builtins<93>-Footnote-124404587
Ref: Core and Builtins<93>-Footnote-134404653
Ref: Core and Builtins<93>-Footnote-144404696
Ref: Core and Builtins<93>-Footnote-154404762
Ref: Core and Builtins<93>-Footnote-164404828
Ref: Core and Builtins<93>-Footnote-174404894
Ref: Core and Builtins<93>-Footnote-184404960
Ref: Core and Builtins<93>-Footnote-194405026
Node: Library<96>4405092
Ref: whatsnew/changelog id4284405221
Ref: 1bcf4405221
Ref: Library<96>-Footnote-14405441
Node: Core and Builtins<94>4405506
Ref: whatsnew/changelog id4294405625
Ref: 1bd04405625
Ref: Core and Builtins<94>-Footnote-14406362
Ref: Core and Builtins<94>-Footnote-24406427
Ref: Core and Builtins<94>-Footnote-34406492
Ref: Core and Builtins<94>-Footnote-44406557
Node: Library<97>4406622
Ref: whatsnew/changelog id4304406739
Ref: 1bd24406739
Ref: Library<97>-Footnote-14406867
Node: Build<37>4406932
Ref: whatsnew/changelog id4314407049
Ref: 1bd34407049
Ref: Build<37>-Footnote-14407176
Node: Core and Builtins<95>4407241
Ref: whatsnew/changelog id4324407358
Ref: 1bd44407358
Ref: Core and Builtins<95>-Footnote-14407658
Node: Library<98>4407723
Ref: whatsnew/changelog id4334407848
Ref: 1bd54407848
Ref: Library<98>-Footnote-14413797
Ref: Library<98>-Footnote-24413862
Ref: Library<98>-Footnote-34413927
Ref: Library<98>-Footnote-44413992
Ref: Library<98>-Footnote-54414057
Ref: Library<98>-Footnote-64414122
Ref: Library<98>-Footnote-74414187
Ref: Library<98>-Footnote-84414252
Ref: Library<98>-Footnote-94414317
Ref: Library<98>-Footnote-104414382
Ref: Library<98>-Footnote-114414448
Ref: Library<98>-Footnote-124414514
Ref: Library<98>-Footnote-134414580
Ref: Library<98>-Footnote-144414646
Ref: Library<98>-Footnote-154414712
Ref: Library<98>-Footnote-164414778
Ref: Library<98>-Footnote-174414844
Ref: Library<98>-Footnote-184414910
Ref: Library<98>-Footnote-194414976
Ref: Library<98>-Footnote-204415042
Ref: Library<98>-Footnote-214415108
Ref: Library<98>-Footnote-224415174
Ref: Library<98>-Footnote-234415240
Ref: Library<98>-Footnote-244415306
Ref: Library<98>-Footnote-254415372
Ref: Library<98>-Footnote-264415438
Ref: Library<98>-Footnote-274415504
Ref: Library<98>-Footnote-284415570
Ref: Library<98>-Footnote-294415636
Ref: Library<98>-Footnote-304415702
Ref: Library<98>-Footnote-314415768
Ref: Library<98>-Footnote-324415834
Ref: Library<98>-Footnote-334415900
Ref: Library<98>-Footnote-344415966
Ref: Library<98>-Footnote-354416032
Ref: Library<98>-Footnote-364416098
Ref: Library<98>-Footnote-374416164
Node: Documentation<31>4416230
Ref: whatsnew/changelog id4344416343
Ref: 1bdb4416343
Ref: Documentation<31>-Footnote-14416532
Node: Tests<31>4416597
Ref: whatsnew/changelog id4354416708
Ref: 1bdc4416708
Ref: Tests<31>-Footnote-14418857
Ref: Tests<31>-Footnote-24418922
Ref: Tests<31>-Footnote-34418987
Ref: Tests<31>-Footnote-44419052
Ref: Tests<31>-Footnote-54419117
Ref: Tests<31>-Footnote-64419182
Ref: Tests<31>-Footnote-74419247
Ref: Tests<31>-Footnote-84419312
Ref: Tests<31>-Footnote-94419377
Ref: Tests<31>-Footnote-104419442
Ref: Tests<31>-Footnote-114419508
Node: Build<38>4419574
Ref: whatsnew/changelog id4364419679
Ref: 1bdd4419679
Ref: Build<38>-Footnote-14421415
Ref: Build<38>-Footnote-24421480
Ref: Build<38>-Footnote-34421545
Ref: Build<38>-Footnote-44421610
Ref: Build<38>-Footnote-54421675
Ref: Build<38>-Footnote-64421740
Ref: Build<38>-Footnote-74421805
Ref: Build<38>-Footnote-84421870
Ref: Build<38>-Footnote-94421935
Ref: Build<38>-Footnote-104422000
Node: Windows<32>4422066
Ref: whatsnew/changelog id4374422171
Ref: 1bde4422171
Ref: Windows<32>-Footnote-14422705
Ref: Windows<32>-Footnote-24422770
Ref: Windows<32>-Footnote-34422835
Node: macOS<22>4422900
Ref: whatsnew/changelog id4384423004
Ref: 1bdf4423004
Ref: macOS<22>-Footnote-14423136
Node: IDLE<17>4423201
Ref: whatsnew/changelog id4394423303
Ref: 1be04423303
Ref: IDLE<17>-Footnote-14423724
Node: C API<33>4423789
Ref: whatsnew/changelog id4404423873
Ref: 1be14423873
Ref: C API<33>-Footnote-14424766
Ref: C API<33>-Footnote-24424831
Ref: C API<33>-Footnote-34424896
Ref: C API<33>-Footnote-44424961
Ref: C API<33>-Footnote-54425026
Node: Python 3 11 0 alpha 44425091
Ref: whatsnew/changelog python-3-11-0-alpha-44425218
Ref: 1be24425218
Node: Core and Builtins<96>4425732
Ref: whatsnew/changelog id4414425831
Ref: 1be34425831
Ref: Core and Builtins<96>-Footnote-14428027
Ref: Core and Builtins<96>-Footnote-24428092
Ref: Core and Builtins<96>-Footnote-34428157
Ref: Core and Builtins<96>-Footnote-44428222
Ref: Core and Builtins<96>-Footnote-54428287
Ref: Core and Builtins<96>-Footnote-64428352
Ref: Core and Builtins<96>-Footnote-74428417
Ref: Core and Builtins<96>-Footnote-84428482
Ref: Core and Builtins<96>-Footnote-94428547
Ref: Core and Builtins<96>-Footnote-104428612
Ref: Core and Builtins<96>-Footnote-114428678
Node: Library<99>4428744
Ref: whatsnew/changelog id4424428873
Ref: 1be44428873
Ref: Library<99>-Footnote-14429068
Node: Core and Builtins<97>4429133
Ref: whatsnew/changelog id4434429253
Ref: 1be54429253
Ref: Core and Builtins<97>-Footnote-14429980
Ref: Core and Builtins<97>-Footnote-24430045
Ref: Core and Builtins<97>-Footnote-34430110
Ref: Core and Builtins<97>-Footnote-44430175
Ref: Core and Builtins<97>-Footnote-54430240
Node: Library<100>4430305
Ref: whatsnew/changelog id4444430435
Ref: 1be64430435
Ref: Library<100>-Footnote-14430579
Node: Core and Builtins<98>4430644
Ref: whatsnew/changelog id4454430765
Ref: 1be74430765
Ref: Core and Builtins<98>-Footnote-14433318
Ref: Core and Builtins<98>-Footnote-24433383
Ref: Core and Builtins<98>-Footnote-34433448
Ref: Core and Builtins<98>-Footnote-44433513
Ref: Core and Builtins<98>-Footnote-54433578
Ref: Core and Builtins<98>-Footnote-64433643
Ref: Core and Builtins<98>-Footnote-74433708
Ref: Core and Builtins<98>-Footnote-84433773
Ref: Core and Builtins<98>-Footnote-94433838
Ref: Core and Builtins<98>-Footnote-104433903
Ref: Core and Builtins<98>-Footnote-114433969
Ref: Core and Builtins<98>-Footnote-124434035
Ref: Core and Builtins<98>-Footnote-134434101
Ref: Core and Builtins<98>-Footnote-144434167
Ref: Core and Builtins<98>-Footnote-154434233
Node: Library<101>4434299
Ref: whatsnew/changelog id4464434429
Ref: 1be94434429
Ref: Library<101>-Footnote-14434601
Node: Core and Builtins<99>4434666
Ref: whatsnew/changelog id4474434787
Ref: 1bea4434787
Ref: Core and Builtins<99>-Footnote-14436068
Ref: Core and Builtins<99>-Footnote-24436133
Ref: Core and Builtins<99>-Footnote-34436198
Ref: Core and Builtins<99>-Footnote-44436263
Ref: Core and Builtins<99>-Footnote-54436328
Ref: Core and Builtins<99>-Footnote-64436370
Ref: Core and Builtins<99>-Footnote-74436435
Node: Library<102>4436500
Ref: whatsnew/changelog id4484436626
Ref: 1beb4436626
Ref: Library<102>-Footnote-14443906
Ref: Library<102>-Footnote-24443971
Ref: Library<102>-Footnote-34444036
Ref: Library<102>-Footnote-44444101
Ref: Library<102>-Footnote-54444166
Ref: Library<102>-Footnote-64444231
Ref: Library<102>-Footnote-74444296
Ref: Library<102>-Footnote-84444361
Ref: Library<102>-Footnote-94444426
Ref: Library<102>-Footnote-104444491
Ref: Library<102>-Footnote-114444557
Ref: Library<102>-Footnote-124444623
Ref: Library<102>-Footnote-134444689
Ref: Library<102>-Footnote-144444755
Ref: Library<102>-Footnote-154444821
Ref: Library<102>-Footnote-164444887
Ref: Library<102>-Footnote-174444953
Ref: Library<102>-Footnote-184445019
Ref: Library<102>-Footnote-194445085
Ref: Library<102>-Footnote-204445151
Ref: Library<102>-Footnote-214445217
Ref: Library<102>-Footnote-224445283
Ref: Library<102>-Footnote-234445349
Ref: Library<102>-Footnote-244445415
Ref: Library<102>-Footnote-254445481
Ref: Library<102>-Footnote-264445547
Ref: Library<102>-Footnote-274445613
Ref: Library<102>-Footnote-284445679
Ref: Library<102>-Footnote-294445745
Ref: Library<102>-Footnote-304445811
Ref: Library<102>-Footnote-314445877
Ref: Library<102>-Footnote-324445943
Ref: Library<102>-Footnote-334446009
Ref: Library<102>-Footnote-344446075
Ref: Library<102>-Footnote-354446141
Ref: Library<102>-Footnote-364446207
Ref: Library<102>-Footnote-374446273
Ref: Library<102>-Footnote-384446339
Ref: Library<102>-Footnote-394446405
Ref: Library<102>-Footnote-404446471
Ref: Library<102>-Footnote-414446537
Ref: Library<102>-Footnote-424446603
Ref: Library<102>-Footnote-434446669
Ref: Library<102>-Footnote-444446735
Node: Documentation<32>4446801
Ref: whatsnew/changelog id4494446915
Ref: 1bf04446915
Ref: Documentation<32>-Footnote-14447412
Ref: Documentation<32>-Footnote-24447477
Ref: Documentation<32>-Footnote-34447542
Ref: Documentation<32>-Footnote-44447607
Node: Tests<32>4447672
Ref: whatsnew/changelog id4504447783
Ref: 1bf34447783
Ref: Tests<32>-Footnote-14448713
Ref: Tests<32>-Footnote-24448778
Ref: Tests<32>-Footnote-34448843
Ref: Tests<32>-Footnote-44448908
Ref: Tests<32>-Footnote-54448973
Ref: Tests<32>-Footnote-64449038
Ref: Tests<32>-Footnote-74449103
Ref: Tests<32>-Footnote-84449168
Node: Build<39>4449233
Ref: whatsnew/changelog id4514449338
Ref: 1bf44449338
Ref: Build<39>-Footnote-14451403
Ref: Build<39>-Footnote-24451468
Ref: Build<39>-Footnote-34451533
Ref: Build<39>-Footnote-44451598
Ref: Build<39>-Footnote-54451663
Ref: Build<39>-Footnote-64451728
Ref: Build<39>-Footnote-74451793
Ref: Build<39>-Footnote-84451858
Ref: Build<39>-Footnote-94451923
Ref: Build<39>-Footnote-104451988
Ref: Build<39>-Footnote-114452054
Ref: Build<39>-Footnote-124452120
Node: Windows<33>4452186
Ref: whatsnew/changelog id4524452291
Ref: 1bf54452291
Ref: Windows<33>-Footnote-14452512
Node: macOS<23>4452577
Ref: whatsnew/changelog id4534452682
Ref: 1bf64452682
Ref: macOS<23>-Footnote-14452922
Node: C API<34>4452987
Ref: whatsnew/changelog id4544453072
Ref: 1bf74453072
Ref: C API<34>-Footnote-14454350
Ref: C API<34>-Footnote-24454415
Ref: C API<34>-Footnote-34454480
Ref: C API<34>-Footnote-44454545
Ref: C API<34>-Footnote-54454610
Node: Python 3 11 0 alpha 34454675
Ref: whatsnew/changelog python-3-11-0-alpha-34454802
Ref: 1bf94454802
Node: Core and Builtins<100>4455181
Ref: whatsnew/changelog id4554455282
Ref: 1bfa4455282
Ref: Core and Builtins<100>-Footnote-14457867
Ref: Core and Builtins<100>-Footnote-24457932
Ref: Core and Builtins<100>-Footnote-34457997
Ref: Core and Builtins<100>-Footnote-44458062
Ref: Core and Builtins<100>-Footnote-54458127
Ref: Core and Builtins<100>-Footnote-64458192
Ref: Core and Builtins<100>-Footnote-74458257
Ref: Core and Builtins<100>-Footnote-84458322
Ref: Core and Builtins<100>-Footnote-94458387
Ref: Core and Builtins<100>-Footnote-104458452
Ref: Core and Builtins<100>-Footnote-114458518
Ref: Core and Builtins<100>-Footnote-124458584
Node: Library<103>4458650
Ref: whatsnew/changelog id4564458782
Ref: 1bfc4458782
Ref: Library<103>-Footnote-14458955
Node: Core and Builtins<101>4459020
Ref: whatsnew/changelog id4574459142
Ref: 1bfd4459142
Ref: Core and Builtins<101>-Footnote-14462162
Ref: Core and Builtins<101>-Footnote-24462227
Ref: Core and Builtins<101>-Footnote-34462292
Ref: Core and Builtins<101>-Footnote-44462357
Ref: Core and Builtins<101>-Footnote-54462422
Ref: Core and Builtins<101>-Footnote-64462487
Ref: Core and Builtins<101>-Footnote-74462552
Ref: Core and Builtins<101>-Footnote-84462617
Ref: Core and Builtins<101>-Footnote-94462682
Ref: Core and Builtins<101>-Footnote-104462724
Ref: Core and Builtins<101>-Footnote-114462790
Ref: Core and Builtins<101>-Footnote-124462856
Ref: Core and Builtins<101>-Footnote-134462922
Ref: Core and Builtins<101>-Footnote-144462988
Ref: Core and Builtins<101>-Footnote-154463054
Ref: Core and Builtins<101>-Footnote-164463120
Ref: Core and Builtins<101>-Footnote-174463186
Ref: Core and Builtins<101>-Footnote-184463252
Ref: Core and Builtins<101>-Footnote-194463318
Ref: Core and Builtins<101>-Footnote-204463384
Ref: Core and Builtins<101>-Footnote-214463450
Node: Library<104>4463516
Ref: whatsnew/changelog id4584463643
Ref: 1bfe4463643
Ref: Library<104>-Footnote-14469614
Ref: Library<104>-Footnote-24469679
Ref: Library<104>-Footnote-34469744
Ref: Library<104>-Footnote-44469809
Ref: Library<104>-Footnote-54469874
Ref: Library<104>-Footnote-64469939
Ref: Library<104>-Footnote-74470004
Ref: Library<104>-Footnote-84470069
Ref: Library<104>-Footnote-94470134
Ref: Library<104>-Footnote-104470199
Ref: Library<104>-Footnote-114470265
Ref: Library<104>-Footnote-124470331
Ref: Library<104>-Footnote-134470397
Ref: Library<104>-Footnote-144470463
Ref: Library<104>-Footnote-154470529
Ref: Library<104>-Footnote-164470595
Ref: Library<104>-Footnote-174470661
Ref: Library<104>-Footnote-184470727
Ref: Library<104>-Footnote-194470793
Ref: Library<104>-Footnote-204470859
Ref: Library<104>-Footnote-214470925
Ref: Library<104>-Footnote-224470991
Ref: Library<104>-Footnote-234471057
Ref: Library<104>-Footnote-244471123
Ref: Library<104>-Footnote-254471189
Ref: Library<104>-Footnote-264471255
Ref: Library<104>-Footnote-274471321
Ref: Library<104>-Footnote-284471387
Ref: Library<104>-Footnote-294471453
Ref: Library<104>-Footnote-304471519
Ref: Library<104>-Footnote-314471585
Ref: Library<104>-Footnote-324471628
Ref: Library<104>-Footnote-334471694
Ref: Library<104>-Footnote-344471760
Ref: Library<104>-Footnote-354471826
Ref: Library<104>-Footnote-364471892
Node: Documentation<33>4471958
Ref: whatsnew/changelog id4594472072
Ref: 1c004472072
Ref: Documentation<33>-Footnote-14473380
Ref: Documentation<33>-Footnote-24473445
Ref: Documentation<33>-Footnote-34473510
Ref: Documentation<33>-Footnote-44473575
Ref: Documentation<33>-Footnote-54473640
Ref: Documentation<33>-Footnote-64473705
Ref: Documentation<33>-Footnote-74473770
Ref: Documentation<33>-Footnote-84473835
Ref: Documentation<33>-Footnote-94473900
Node: Tests<33>4473965
Ref: whatsnew/changelog id4604474076
Ref: 1c014474076
Ref: Tests<33>-Footnote-14474885
Ref: Tests<33>-Footnote-24474950
Ref: Tests<33>-Footnote-34475015
Ref: Tests<33>-Footnote-44475080
Ref: Tests<33>-Footnote-54475145
Ref: Tests<33>-Footnote-64475210
Node: Build<40>4475275
Ref: whatsnew/changelog id4614475380
Ref: 1c024475380
Ref: Build<40>-Footnote-14481177
Ref: Build<40>-Footnote-24481242
Ref: Build<40>-Footnote-34481307
Ref: Build<40>-Footnote-44481372
Ref: Build<40>-Footnote-54481437
Ref: Build<40>-Footnote-64481502
Ref: Build<40>-Footnote-74481567
Ref: Build<40>-Footnote-84481632
Ref: Build<40>-Footnote-94481697
Ref: Build<40>-Footnote-104481762
Ref: Build<40>-Footnote-114481828
Ref: Build<40>-Footnote-124481894
Ref: Build<40>-Footnote-134481960
Ref: Build<40>-Footnote-144482026
Ref: Build<40>-Footnote-154482092
Ref: Build<40>-Footnote-164482158
Ref: Build<40>-Footnote-174482224
Ref: Build<40>-Footnote-184482290
Ref: Build<40>-Footnote-194482356
Ref: Build<40>-Footnote-204482422
Ref: Build<40>-Footnote-214482488
Ref: Build<40>-Footnote-224482554
Ref: Build<40>-Footnote-234482620
Ref: Build<40>-Footnote-244482686
Ref: Build<40>-Footnote-254482752
Ref: Build<40>-Footnote-264482818
Ref: Build<40>-Footnote-274482884
Ref: Build<40>-Footnote-284482950
Ref: Build<40>-Footnote-294483016
Ref: Build<40>-Footnote-304483082
Ref: Build<40>-Footnote-314483148
Ref: Build<40>-Footnote-324483214
Ref: Build<40>-Footnote-334483280
Node: Windows<34>4483346
Ref: whatsnew/changelog id4624483451
Ref: 1c034483451
Ref: Windows<34>-Footnote-14484638
Ref: Windows<34>-Footnote-24484703
Ref: Windows<34>-Footnote-34484768
Ref: Windows<34>-Footnote-44484833
Ref: Windows<34>-Footnote-54484898
Ref: Windows<34>-Footnote-64484963
Node: macOS<24>4485028
Ref: whatsnew/changelog id4634485133
Ref: 1c044485133
Ref: macOS<24>-Footnote-14485283
Node: C API<35>4485348
Ref: whatsnew/changelog id4644485433
Ref: 1c054485433
Ref: C API<35>-Footnote-14485640
Node: Python 3 11 0 alpha 24485705
Ref: whatsnew/changelog python-3-11-0-alpha-24485832
Ref: 1c064485832
Node: Core and Builtins<102>4486159
Ref: whatsnew/changelog id4654486260
Ref: 1c074486260
Ref: Core and Builtins<102>-Footnote-14491635
Ref: Core and Builtins<102>-Footnote-24491700
Ref: Core and Builtins<102>-Footnote-34491765
Ref: Core and Builtins<102>-Footnote-44491830
Ref: Core and Builtins<102>-Footnote-54491895
Ref: Core and Builtins<102>-Footnote-64491960
Ref: Core and Builtins<102>-Footnote-74492025
Ref: Core and Builtins<102>-Footnote-84492090
Ref: Core and Builtins<102>-Footnote-94492155
Ref: Core and Builtins<102>-Footnote-104492220
Ref: Core and Builtins<102>-Footnote-114492286
Ref: Core and Builtins<102>-Footnote-124492352
Ref: Core and Builtins<102>-Footnote-134492418
Ref: Core and Builtins<102>-Footnote-144492484
Ref: Core and Builtins<102>-Footnote-154492550
Ref: Core and Builtins<102>-Footnote-164492616
Ref: Core and Builtins<102>-Footnote-174492682
Ref: Core and Builtins<102>-Footnote-184492748
Ref: Core and Builtins<102>-Footnote-194492814
Ref: Core and Builtins<102>-Footnote-204492880
Ref: Core and Builtins<102>-Footnote-214492923
Ref: Core and Builtins<102>-Footnote-224492989
Ref: Core and Builtins<102>-Footnote-234493055
Ref: Core and Builtins<102>-Footnote-244493121
Ref: Core and Builtins<102>-Footnote-254493187
Ref: Core and Builtins<102>-Footnote-264493253
Node: Library<105>4493296
Ref: whatsnew/changelog id4664493423
Ref: 1c094493423
Ref: Library<105>-Footnote-14500989
Ref: Library<105>-Footnote-24501054
Ref: Library<105>-Footnote-34501119
Ref: Library<105>-Footnote-44501184
Ref: Library<105>-Footnote-54501249
Ref: Library<105>-Footnote-64501314
Ref: Library<105>-Footnote-74501379
Ref: Library<105>-Footnote-84501444
Ref: Library<105>-Footnote-94501509
Ref: Library<105>-Footnote-104501574
Ref: Library<105>-Footnote-114501640
Ref: Library<105>-Footnote-124501706
Ref: Library<105>-Footnote-134501772
Ref: Library<105>-Footnote-144501838
Ref: Library<105>-Footnote-154501904
Ref: Library<105>-Footnote-164501970
Ref: Library<105>-Footnote-174502036
Ref: Library<105>-Footnote-184502102
Ref: Library<105>-Footnote-194502168
Ref: Library<105>-Footnote-204502234
Ref: Library<105>-Footnote-214502300
Ref: Library<105>-Footnote-224502366
Ref: Library<105>-Footnote-234502432
Ref: Library<105>-Footnote-244502498
Ref: Library<105>-Footnote-254502564
Ref: Library<105>-Footnote-264502630
Ref: Library<105>-Footnote-274502696
Ref: Library<105>-Footnote-284502762
Ref: Library<105>-Footnote-294502828
Ref: Library<105>-Footnote-304502894
Ref: Library<105>-Footnote-314502960
Ref: Library<105>-Footnote-324503026
Ref: Library<105>-Footnote-334503092
Ref: Library<105>-Footnote-344503158
Ref: Library<105>-Footnote-354503224
Ref: Library<105>-Footnote-364503290
Ref: Library<105>-Footnote-374503356
Ref: Library<105>-Footnote-384503422
Ref: Library<105>-Footnote-394503488
Ref: Library<105>-Footnote-404503554
Ref: Library<105>-Footnote-414503620
Ref: Library<105>-Footnote-424503686
Ref: Library<105>-Footnote-434503752
Ref: Library<105>-Footnote-444503812
Ref: Library<105>-Footnote-454503878
Node: Documentation<34>4503944
Ref: whatsnew/changelog id4674504058
Ref: 1c0e4504058
Ref: Documentation<34>-Footnote-14505538
Ref: Documentation<34>-Footnote-24505603
Ref: Documentation<34>-Footnote-34505668
Ref: Documentation<34>-Footnote-44505733
Ref: Documentation<34>-Footnote-54505798
Ref: Documentation<34>-Footnote-64505863
Ref: Documentation<34>-Footnote-74505928
Ref: Documentation<34>-Footnote-84505993
Ref: Documentation<34>-Footnote-94506058
Ref: Documentation<34>-Footnote-104506100
Ref: Documentation<34>-Footnote-114506166
Node: Tests<34>4506232
Ref: whatsnew/changelog id4684506343
Ref: 1c104506343
Ref: Tests<34>-Footnote-14508613
Ref: Tests<34>-Footnote-24508678
Ref: Tests<34>-Footnote-34508743
Ref: Tests<34>-Footnote-44508808
Ref: Tests<34>-Footnote-54508873
Ref: Tests<34>-Footnote-64508938
Ref: Tests<34>-Footnote-74509003
Ref: Tests<34>-Footnote-84509068
Ref: Tests<34>-Footnote-94509133
Ref: Tests<34>-Footnote-104509198
Ref: Tests<34>-Footnote-114509264
Ref: Tests<34>-Footnote-124509330
Ref: Tests<34>-Footnote-134509396
Node: Build<41>4509462
Ref: whatsnew/changelog id4694509567
Ref: 1c114509567
Ref: Build<41>-Footnote-14512244
Ref: Build<41>-Footnote-24512309
Ref: Build<41>-Footnote-34512374
Ref: Build<41>-Footnote-44512439
Ref: Build<41>-Footnote-54512504
Ref: Build<41>-Footnote-64512569
Ref: Build<41>-Footnote-74512634
Ref: Build<41>-Footnote-84512699
Ref: Build<41>-Footnote-94512764
Ref: Build<41>-Footnote-104512829
Ref: Build<41>-Footnote-114512895
Ref: Build<41>-Footnote-124512961
Ref: Build<41>-Footnote-134513027
Ref: Build<41>-Footnote-144513093
Ref: Build<41>-Footnote-154513159
Node: Windows<35>4513225
Ref: whatsnew/changelog id4704513330
Ref: 1c124513330
Ref: Windows<35>-Footnote-14513885
Ref: Windows<35>-Footnote-24513950
Ref: Windows<35>-Footnote-34514015
Node: macOS<25>4514080
Ref: whatsnew/changelog id4714514184
Ref: 1c134514184
Ref: macOS<25>-Footnote-14514445
Node: IDLE<18>4514510
Ref: whatsnew/changelog id4724514612
Ref: 1c144514612
Ref: IDLE<18>-Footnote-14514773
Node: C API<36>4514838
Ref: whatsnew/changelog id4734514922
Ref: 1c154514922
Ref: C API<36>-Footnote-14518650
Ref: C API<36>-Footnote-24518715
Ref: C API<36>-Footnote-34518780
Ref: C API<36>-Footnote-44518845
Ref: C API<36>-Footnote-54518910
Ref: C API<36>-Footnote-64518975
Ref: C API<36>-Footnote-74519040
Ref: C API<36>-Footnote-84519105
Ref: C API<36>-Footnote-94519170
Ref: C API<36>-Footnote-104519235
Ref: C API<36>-Footnote-114519301
Ref: C API<36>-Footnote-124519367
Ref: C API<36>-Footnote-134519433
Ref: C API<36>-Footnote-144519499
Node: Python 3 11 0 alpha 14519565
Ref: whatsnew/changelog python-3-11-0-alpha-14519691
Ref: 1c164519691
Node: Security<29>4520706
Ref: whatsnew/changelog id4744520807
Ref: 1c174520807
Ref: Security<29>-Footnote-14522164
Ref: Security<29>-Footnote-24522229
Ref: Security<29>-Footnote-34522294
Ref: Security<29>-Footnote-44522359
Ref: Security<29>-Footnote-54522424
Ref: Security<29>-Footnote-64522479
Ref: Security<29>-Footnote-74522544
Node: Core and Builtins<103>4522609
Ref: whatsnew/changelog id4754522731
Ref: 1c194522731
Ref: Core and Builtins<103>-Footnote-14523842
Ref: Core and Builtins<103>-Footnote-24523907
Ref: Core and Builtins<103>-Footnote-34523972
Ref: Core and Builtins<103>-Footnote-44524037
Ref: Core and Builtins<103>-Footnote-54524102
Ref: Core and Builtins<103>-Footnote-64524167
Node: Library<106>4524232
Ref: whatsnew/changelog id4764524364
Ref: 1c1b4524364
Ref: Library<106>-Footnote-14524862
Ref: Library<106>-Footnote-24524927
Node: Core and Builtins<104>4524992
Ref: whatsnew/changelog id4774525114
Ref: 1c1e4525114
Ref: Core and Builtins<104>-Footnote-14525299
Node: Library<107>4525364
Ref: whatsnew/changelog id4784525496
Ref: 1c1f4525496
Ref: Library<107>-Footnote-14525751
Node: Core and Builtins<105>4525816
Ref: whatsnew/changelog id4794525938
Ref: 1c204525938
Ref: Core and Builtins<105>-Footnote-14528773
Ref: Core and Builtins<105>-Footnote-24528838
Ref: Core and Builtins<105>-Footnote-34528903
Ref: Core and Builtins<105>-Footnote-44528970
Ref: Core and Builtins<105>-Footnote-54529035
Ref: Core and Builtins<105>-Footnote-64529100
Ref: Core and Builtins<105>-Footnote-74529165
Ref: Core and Builtins<105>-Footnote-84529230
Ref: Core and Builtins<105>-Footnote-94529295
Node: Library<108>4529360
Ref: whatsnew/changelog id4804529492
Ref: 1c214529492
Ref: Library<108>-Footnote-14529765
Node: Core and Builtins<106>4529830
Ref: whatsnew/changelog id4814529952
Ref: 1c224529952
Ref: Core and Builtins<106>-Footnote-14530411
Ref: Core and Builtins<106>-Footnote-24530476
Ref: Core and Builtins<106>-Footnote-34530541
Node: Library<109>4530606
Ref: whatsnew/changelog id4824530738
Ref: 1c234530738
Ref: Library<109>-Footnote-14531077
Node: Core and Builtins<107>4531142
Ref: whatsnew/changelog id4834531264
Ref: 1c244531264
Ref: Core and Builtins<107>-Footnote-14532278
Ref: Core and Builtins<107>-Footnote-24532343
Ref: Core and Builtins<107>-Footnote-34532408
Ref: Core and Builtins<107>-Footnote-44532473
Ref: Core and Builtins<107>-Footnote-54532538
Node: Library<110>4532603
Ref: whatsnew/changelog id4844532735
Ref: 1c254532735
Ref: Library<110>-Footnote-14532933
Node: Core and Builtins<108>4532998
Ref: whatsnew/changelog id4854533120
Ref: 1c264533120
Ref: Core and Builtins<108>-Footnote-14538158
Ref: Core and Builtins<108>-Footnote-24538223
Ref: Core and Builtins<108>-Footnote-34538288
Ref: Core and Builtins<108>-Footnote-44538353
Ref: Core and Builtins<108>-Footnote-54538418
Ref: Core and Builtins<108>-Footnote-64538483
Ref: Core and Builtins<108>-Footnote-74538548
Ref: Core and Builtins<108>-Footnote-84538613
Ref: Core and Builtins<108>-Footnote-94538678
Ref: Core and Builtins<108>-Footnote-104538743
Ref: Core and Builtins<108>-Footnote-114538809
Ref: Core and Builtins<108>-Footnote-124538875
Ref: Core and Builtins<108>-Footnote-134538941
Ref: Core and Builtins<108>-Footnote-144539007
Ref: Core and Builtins<108>-Footnote-154539073
Ref: Core and Builtins<108>-Footnote-164539139
Ref: Core and Builtins<108>-Footnote-174539205
Ref: Core and Builtins<108>-Footnote-184539271
Ref: Core and Builtins<108>-Footnote-194539337
Ref: Core and Builtins<108>-Footnote-204539403
Ref: Core and Builtins<108>-Footnote-214539469
Ref: Core and Builtins<108>-Footnote-224539535
Ref: Core and Builtins<108>-Footnote-234539601
Ref: Core and Builtins<108>-Footnote-244539667
Ref: Core and Builtins<108>-Footnote-254539733
Ref: Core and Builtins<108>-Footnote-264539799
Ref: Core and Builtins<108>-Footnote-274539865
Ref: Core and Builtins<108>-Footnote-284539931
Ref: Core and Builtins<108>-Footnote-294539997
Ref: Core and Builtins<108>-Footnote-304540063
Ref: Core and Builtins<108>-Footnote-314540129
Ref: Core and Builtins<108>-Footnote-324540195
Node: Library<111>4540261
Ref: whatsnew/changelog id4864540393
Ref: 1c284540393
Ref: Library<111>-Footnote-14540660
Node: Core and Builtins<109>4540725
Ref: whatsnew/changelog id4874540847
Ref: 1c294540847
Ref: Core and Builtins<109>-Footnote-14542691
Ref: Core and Builtins<109>-Footnote-24542756
Ref: Core and Builtins<109>-Footnote-34542821
Ref: Core and Builtins<109>-Footnote-44542886
Ref: Core and Builtins<109>-Footnote-54542951
Ref: Core and Builtins<109>-Footnote-64543016
Ref: Core and Builtins<109>-Footnote-74543081
Ref: Core and Builtins<109>-Footnote-84543146
Ref: Core and Builtins<109>-Footnote-94543211
Node: Library<112>4543276
Ref: whatsnew/changelog id4884543408
Ref: 1c2a4543408
Ref: Library<112>-Footnote-14543734
Node: Core and Builtins<110>4543799
Ref: whatsnew/changelog id4894543921
Ref: 1c2b4543921
Ref: Core and Builtins<110>-Footnote-14544454
Ref: Core and Builtins<110>-Footnote-24544519
Ref: Core and Builtins<110>-Footnote-34544561
Node: Library<113>4544626
Ref: whatsnew/changelog id4904544758
Ref: 1c2c4544758
Ref: Library<113>-Footnote-14545068
Node: Core and Builtins<111>4545133
Ref: whatsnew/changelog id4914545255
Ref: 1c2d4545255
Ref: Core and Builtins<111>-Footnote-14549019
Ref: Core and Builtins<111>-Footnote-24549084
Ref: Core and Builtins<111>-Footnote-34549126
Ref: Core and Builtins<111>-Footnote-44549191
Ref: Core and Builtins<111>-Footnote-54549256
Ref: Core and Builtins<111>-Footnote-64549321
Ref: Core and Builtins<111>-Footnote-74549386
Ref: Core and Builtins<111>-Footnote-84549451
Ref: Core and Builtins<111>-Footnote-94549516
Ref: Core and Builtins<111>-Footnote-104549581
Ref: Core and Builtins<111>-Footnote-114549647
Ref: Core and Builtins<111>-Footnote-124549713
Ref: Core and Builtins<111>-Footnote-134549779
Ref: Core and Builtins<111>-Footnote-144549845
Ref: Core and Builtins<111>-Footnote-154549911
Ref: Core and Builtins<111>-Footnote-164549977
Ref: Core and Builtins<111>-Footnote-174550043
Ref: Core and Builtins<111>-Footnote-184550109
Ref: Core and Builtins<111>-Footnote-194550175
Ref: Core and Builtins<111>-Footnote-204550241
Ref: Core and Builtins<111>-Footnote-214550307
Ref: Core and Builtins<111>-Footnote-224550373
Node: Library<114>4550439
Ref: whatsnew/changelog id4924550571
Ref: 1c2e4550571
Ref: Library<114>-Footnote-14550825
Node: Core and Builtins<112>4550890
Ref: whatsnew/changelog id4934551012
Ref: 1c2f4551012
Ref: Core and Builtins<112>-Footnote-14556679
Ref: Core and Builtins<112>-Footnote-24556744
Ref: Core and Builtins<112>-Footnote-34556809
Ref: Core and Builtins<112>-Footnote-44556874
Ref: Core and Builtins<112>-Footnote-54556939
Ref: Core and Builtins<112>-Footnote-64557004
Ref: Core and Builtins<112>-Footnote-74557069
Ref: Core and Builtins<112>-Footnote-84557134
Ref: Core and Builtins<112>-Footnote-94557199
Ref: Core and Builtins<112>-Footnote-104557264
Ref: Core and Builtins<112>-Footnote-114557330
Ref: Core and Builtins<112>-Footnote-124557396
Ref: Core and Builtins<112>-Footnote-134557462
Ref: Core and Builtins<112>-Footnote-144557528
Ref: Core and Builtins<112>-Footnote-154557594
Ref: Core and Builtins<112>-Footnote-164557660
Ref: Core and Builtins<112>-Footnote-174557726
Ref: Core and Builtins<112>-Footnote-184557792
Ref: Core and Builtins<112>-Footnote-194557858
Ref: Core and Builtins<112>-Footnote-204557924
Ref: Core and Builtins<112>-Footnote-214557990
Ref: Core and Builtins<112>-Footnote-224558056
Ref: Core and Builtins<112>-Footnote-234558122
Ref: Core and Builtins<112>-Footnote-244558188
Ref: Core and Builtins<112>-Footnote-254558254
Ref: Core and Builtins<112>-Footnote-264558320
Ref: Core and Builtins<112>-Footnote-274558386
Ref: Core and Builtins<112>-Footnote-284558452
Ref: Core and Builtins<112>-Footnote-294558518
Ref: Core and Builtins<112>-Footnote-304558584
Node: Library<115>4558650
Ref: whatsnew/changelog id4944558777
Ref: 1c304558777
Ref: Library<115>-Footnote-14598589
Ref: Library<115>-Footnote-24598654
Ref: Library<115>-Footnote-34598719
Ref: Library<115>-Footnote-44598784
Ref: Library<115>-Footnote-54598851
Ref: Library<115>-Footnote-64598916
Ref: Library<115>-Footnote-74598981
Ref: Library<115>-Footnote-84599046
Ref: Library<115>-Footnote-94599111
Ref: Library<115>-Footnote-104599176
Ref: Library<115>-Footnote-114599242
Ref: Library<115>-Footnote-124599308
Ref: Library<115>-Footnote-134599374
Ref: Library<115>-Footnote-144599440
Ref: Library<115>-Footnote-154599506
Ref: Library<115>-Footnote-164599572
Ref: Library<115>-Footnote-174599638
Ref: Library<115>-Footnote-184599704
Ref: Library<115>-Footnote-194599770
Ref: Library<115>-Footnote-204599836
Ref: Library<115>-Footnote-214599902
Ref: Library<115>-Footnote-224599968
Ref: Library<115>-Footnote-234600034
Ref: Library<115>-Footnote-244600100
Ref: Library<115>-Footnote-254600166
Ref: Library<115>-Footnote-264600232
Ref: Library<115>-Footnote-274600298
Ref: Library<115>-Footnote-284600364
Ref: Library<115>-Footnote-294600430
Ref: Library<115>-Footnote-304600496
Ref: Library<115>-Footnote-314600562
Ref: Library<115>-Footnote-324600628
Ref: Library<115>-Footnote-334600694
Ref: Library<115>-Footnote-344600760
Ref: Library<115>-Footnote-354600826
Ref: Library<115>-Footnote-364600869
Ref: Library<115>-Footnote-374600935
Ref: Library<115>-Footnote-384601001
Ref: Library<115>-Footnote-394601067
Ref: Library<115>-Footnote-404601133
Ref: Library<115>-Footnote-414601199
Ref: Library<115>-Footnote-424601265
Ref: Library<115>-Footnote-434601331
Ref: Library<115>-Footnote-444601397
Ref: Library<115>-Footnote-454601463
Ref: Library<115>-Footnote-464601529
Ref: Library<115>-Footnote-474601595
Ref: Library<115>-Footnote-484601661
Ref: Library<115>-Footnote-494601727
Ref: Library<115>-Footnote-504601793
Ref: Library<115>-Footnote-514601859
Ref: Library<115>-Footnote-524601925
Ref: Library<115>-Footnote-534601991
Ref: Library<115>-Footnote-544602057
Ref: Library<115>-Footnote-554602123
Ref: Library<115>-Footnote-564602189
Ref: Library<115>-Footnote-574602255
Ref: Library<115>-Footnote-584602321
Ref: Library<115>-Footnote-594602387
Ref: Library<115>-Footnote-604602453
Ref: Library<115>-Footnote-614602519
Ref: Library<115>-Footnote-624602585
Ref: Library<115>-Footnote-634602651
Ref: Library<115>-Footnote-644602717
Ref: Library<115>-Footnote-654602783
Ref: Library<115>-Footnote-664602849
Ref: Library<115>-Footnote-674602915
Ref: Library<115>-Footnote-684602981
Ref: Library<115>-Footnote-694603047
Ref: Library<115>-Footnote-704603113
Ref: Library<115>-Footnote-714603179
Ref: Library<115>-Footnote-724603245
Ref: Library<115>-Footnote-734603311
Ref: Library<115>-Footnote-744603377
Ref: Library<115>-Footnote-754603443
Ref: Library<115>-Footnote-764603509
Ref: Library<115>-Footnote-774603575
Ref: Library<115>-Footnote-784603641
Ref: Library<115>-Footnote-794603707
Ref: Library<115>-Footnote-804603773
Ref: Library<115>-Footnote-814603839
Ref: Library<115>-Footnote-824603905
Ref: Library<115>-Footnote-834603971
Ref: Library<115>-Footnote-844604037
Ref: Library<115>-Footnote-854604103
Ref: Library<115>-Footnote-864604169
Ref: Library<115>-Footnote-874604235
Ref: Library<115>-Footnote-884604301
Ref: Library<115>-Footnote-894604367
Ref: Library<115>-Footnote-904604433
Ref: Library<115>-Footnote-914604499
Ref: Library<115>-Footnote-924604565
Ref: Library<115>-Footnote-934604631
Ref: Library<115>-Footnote-944604697
Ref: Library<115>-Footnote-954604763
Ref: Library<115>-Footnote-964604829
Ref: Library<115>-Footnote-974604895
Ref: Library<115>-Footnote-984604961
Ref: Library<115>-Footnote-994605027
Ref: Library<115>-Footnote-1004605093
Ref: Library<115>-Footnote-1014605160
Ref: Library<115>-Footnote-1024605227
Ref: Library<115>-Footnote-1034605294
Ref: Library<115>-Footnote-1044605361
Ref: Library<115>-Footnote-1054605428
Ref: Library<115>-Footnote-1064605495
Ref: Library<115>-Footnote-1074605562
Ref: Library<115>-Footnote-1084605629
Ref: Library<115>-Footnote-1094605696
Ref: Library<115>-Footnote-1104605763
Ref: Library<115>-Footnote-1114605830
Ref: Library<115>-Footnote-1124605897
Ref: Library<115>-Footnote-1134605964
Ref: Library<115>-Footnote-1144606031
Ref: Library<115>-Footnote-1154606098
Ref: Library<115>-Footnote-1164606165
Ref: Library<115>-Footnote-1174606232
Ref: Library<115>-Footnote-1184606299
Ref: Library<115>-Footnote-1194606366
Ref: Library<115>-Footnote-1204606433
Ref: Library<115>-Footnote-1214606500
Ref: Library<115>-Footnote-1224606567
Ref: Library<115>-Footnote-1234606634
Ref: Library<115>-Footnote-1244606701
Ref: Library<115>-Footnote-1254606768
Ref: Library<115>-Footnote-1264606835
Ref: Library<115>-Footnote-1274606902
Ref: Library<115>-Footnote-1284606969
Ref: Library<115>-Footnote-1294607036
Ref: Library<115>-Footnote-1304607103
Ref: Library<115>-Footnote-1314607170
Ref: Library<115>-Footnote-1324607237
Ref: Library<115>-Footnote-1334607304
Ref: Library<115>-Footnote-1344607371
Ref: Library<115>-Footnote-1354607438
Ref: Library<115>-Footnote-1364607505
Ref: Library<115>-Footnote-1374607572
Ref: Library<115>-Footnote-1384607639
Ref: Library<115>-Footnote-1394607706
Ref: Library<115>-Footnote-1404607773
Ref: Library<115>-Footnote-1414607840
Ref: Library<115>-Footnote-1424607907
Ref: Library<115>-Footnote-1434607974
Ref: Library<115>-Footnote-1444608041
Ref: Library<115>-Footnote-1454608108
Ref: Library<115>-Footnote-1464608175
Ref: Library<115>-Footnote-1474608242
Ref: Library<115>-Footnote-1484608308
Ref: Library<115>-Footnote-1494608375
Ref: Library<115>-Footnote-1504608442
Ref: Library<115>-Footnote-1514608503
Ref: Library<115>-Footnote-1524608570
Ref: Library<115>-Footnote-1534608637
Ref: Library<115>-Footnote-1544608704
Ref: Library<115>-Footnote-1554608771
Ref: Library<115>-Footnote-1564608838
Ref: Library<115>-Footnote-1574608905
Ref: Library<115>-Footnote-1584608972
Ref: Library<115>-Footnote-1594609039
Ref: Library<115>-Footnote-1604609083
Ref: Library<115>-Footnote-1614609150
Ref: Library<115>-Footnote-1624609217
Ref: Library<115>-Footnote-1634609284
Ref: Library<115>-Footnote-1644609351
Ref: Library<115>-Footnote-1654609418
Ref: Library<115>-Footnote-1664609485
Ref: Library<115>-Footnote-1674609552
Ref: Library<115>-Footnote-1684609619
Ref: Library<115>-Footnote-1694609686
Ref: Library<115>-Footnote-1704609753
Ref: Library<115>-Footnote-1714609820
Ref: Library<115>-Footnote-1724609887
Ref: Library<115>-Footnote-1734609954
Ref: Library<115>-Footnote-1744610021
Ref: Library<115>-Footnote-1754610088
Ref: Library<115>-Footnote-1764610155
Ref: Library<115>-Footnote-1774610222
Ref: Library<115>-Footnote-1784610289
Ref: Library<115>-Footnote-1794610356
Ref: Library<115>-Footnote-1804610423
Ref: Library<115>-Footnote-1814610490
Ref: Library<115>-Footnote-1824610557
Ref: Library<115>-Footnote-1834610624
Ref: Library<115>-Footnote-1844610691
Ref: Library<115>-Footnote-1854610758
Ref: Library<115>-Footnote-1864610825
Ref: Library<115>-Footnote-1874610892
Ref: Library<115>-Footnote-1884610959
Ref: Library<115>-Footnote-1894611026
Ref: Library<115>-Footnote-1904611093
Ref: Library<115>-Footnote-1914611160
Ref: Library<115>-Footnote-1924611227
Ref: Library<115>-Footnote-1934611294
Ref: Library<115>-Footnote-1944611361
Ref: Library<115>-Footnote-1954611428
Ref: Library<115>-Footnote-1964611494
Ref: Library<115>-Footnote-1974611561
Ref: Library<115>-Footnote-1984611628
Ref: Library<115>-Footnote-1994611695
Ref: Library<115>-Footnote-2004611762
Ref: Library<115>-Footnote-2014611829
Ref: Library<115>-Footnote-2024611896
Ref: Library<115>-Footnote-2034611963
Ref: Library<115>-Footnote-2044612030
Ref: Library<115>-Footnote-2054612097
Ref: Library<115>-Footnote-2064612164
Ref: Library<115>-Footnote-2074612231
Ref: Library<115>-Footnote-2084612298
Ref: Library<115>-Footnote-2094612365
Node: Documentation<35>4612432
Ref: whatsnew/changelog id4954612546
Ref: 1c474612546
Ref: Documentation<35>-Footnote-14618866
Ref: Documentation<35>-Footnote-24618931
Ref: Documentation<35>-Footnote-34618996
Ref: Documentation<35>-Footnote-44619061
Ref: Documentation<35>-Footnote-54619126
Ref: Documentation<35>-Footnote-64619191
Ref: Documentation<35>-Footnote-74619243
Ref: Documentation<35>-Footnote-84619308
Ref: Documentation<35>-Footnote-94619373
Ref: Documentation<35>-Footnote-104619432
Ref: Documentation<35>-Footnote-114619498
Ref: Documentation<35>-Footnote-124619564
Ref: Documentation<35>-Footnote-134619630
Ref: Documentation<35>-Footnote-144619696
Ref: Documentation<35>-Footnote-154619762
Ref: Documentation<35>-Footnote-164619828
Ref: Documentation<35>-Footnote-174619894
Ref: Documentation<35>-Footnote-184619960
Ref: Documentation<35>-Footnote-194620026
Ref: Documentation<35>-Footnote-204620092
Ref: Documentation<35>-Footnote-214620158
Ref: Documentation<35>-Footnote-224620224
Ref: Documentation<35>-Footnote-234620290
Ref: Documentation<35>-Footnote-244620356
Ref: Documentation<35>-Footnote-254620422
Ref: Documentation<35>-Footnote-264620488
Ref: Documentation<35>-Footnote-274620554
Ref: Documentation<35>-Footnote-284620620
Ref: Documentation<35>-Footnote-294620686
Ref: Documentation<35>-Footnote-304620752
Ref: Documentation<35>-Footnote-314620818
Ref: Documentation<35>-Footnote-324620884
Ref: Documentation<35>-Footnote-334620950
Ref: Documentation<35>-Footnote-344621016
Ref: Documentation<35>-Footnote-354621082
Ref: Documentation<35>-Footnote-364621148
Ref: Documentation<35>-Footnote-374621214
Ref: Documentation<35>-Footnote-384621280
Ref: Documentation<35>-Footnote-394621346
Ref: Documentation<35>-Footnote-404621412
Ref: Documentation<35>-Footnote-414621478
Ref: Documentation<35>-Footnote-424621544
Node: Tests<35>4621610
Ref: whatsnew/changelog id4964621721
Ref: 1c494621721
Ref: Tests<35>-Footnote-14627581
Ref: Tests<35>-Footnote-24627646
Ref: Tests<35>-Footnote-34627711
Ref: Tests<35>-Footnote-44627776
Ref: Tests<35>-Footnote-54627841
Ref: Tests<35>-Footnote-64627906
Ref: Tests<35>-Footnote-74627971
Ref: Tests<35>-Footnote-84628036
Ref: Tests<35>-Footnote-94628101
Ref: Tests<35>-Footnote-104628166
Ref: Tests<35>-Footnote-114628232
Ref: Tests<35>-Footnote-124628298
Ref: Tests<35>-Footnote-134628364
Ref: Tests<35>-Footnote-144628430
Ref: Tests<35>-Footnote-154628496
Ref: Tests<35>-Footnote-164628562
Ref: Tests<35>-Footnote-174628628
Ref: Tests<35>-Footnote-184628694
Ref: Tests<35>-Footnote-194628760
Ref: Tests<35>-Footnote-204628826
Ref: Tests<35>-Footnote-214628892
Ref: Tests<35>-Footnote-224628958
Ref: Tests<35>-Footnote-234629024
Ref: Tests<35>-Footnote-244629090
Ref: Tests<35>-Footnote-254629156
Ref: Tests<35>-Footnote-264629222
Ref: Tests<35>-Footnote-274629288
Ref: Tests<35>-Footnote-284629354
Ref: Tests<35>-Footnote-294629420
Ref: Tests<35>-Footnote-304629486
Ref: Tests<35>-Footnote-314629552
Ref: Tests<35>-Footnote-324629618
Ref: Tests<35>-Footnote-334629684
Ref: Tests<35>-Footnote-344629750
Ref: Tests<35>-Footnote-354629816
Node: Build<42>4629882
Ref: whatsnew/changelog id4974629987
Ref: 1c4c4629987
Ref: Build<42>-Footnote-14632064
Ref: Build<42>-Footnote-24632129
Ref: Build<42>-Footnote-34632194
Ref: Build<42>-Footnote-44632259
Ref: Build<42>-Footnote-54632324
Ref: Build<42>-Footnote-64632389
Ref: Build<42>-Footnote-74632454
Ref: Build<42>-Footnote-84632519
Ref: Build<42>-Footnote-94632584
Ref: Build<42>-Footnote-104632649
Ref: Build<42>-Footnote-114632715
Node: Windows<36>4632781
Ref: whatsnew/changelog id4984632886
Ref: 1c4d4632886
Ref: Windows<36>-Footnote-14633996
Ref: Windows<36>-Footnote-24634061
Ref: Windows<36>-Footnote-34634126
Ref: Windows<36>-Footnote-44634191
Ref: Windows<36>-Footnote-54634256
Ref: Windows<36>-Footnote-64634321
Ref: Windows<36>-Footnote-74634386
Ref: Windows<36>-Footnote-84634451
Ref: Windows<36>-Footnote-94634516
Node: macOS<26>4634581
Ref: whatsnew/changelog id4994634685
Ref: 1c4f4634685
Ref: macOS<26>-Footnote-14635842
Ref: macOS<26>-Footnote-24635907
Ref: macOS<26>-Footnote-34635972
Ref: macOS<26>-Footnote-44636037
Ref: macOS<26>-Footnote-54636102
Ref: macOS<26>-Footnote-64636167
Ref: macOS<26>-Footnote-74636232
Node: IDLE<19>4636297
Ref: whatsnew/changelog id5004636405
Ref: 1c504636405
Ref: IDLE<19>-Footnote-14637936
Ref: IDLE<19>-Footnote-24638001
Ref: IDLE<19>-Footnote-34638066
Ref: IDLE<19>-Footnote-44638131
Ref: IDLE<19>-Footnote-54638196
Ref: IDLE<19>-Footnote-64638261
Ref: IDLE<19>-Footnote-74638326
Ref: IDLE<19>-Footnote-84638391
Ref: IDLE<19>-Footnote-94638456
Node: Tools/Demos<27>4638521
Ref: whatsnew/changelog id5014638629
Ref: 1c514638629
Ref: Tools/Demos<27>-Footnote-14639433
Ref: Tools/Demos<27>-Footnote-24639498
Ref: Tools/Demos<27>-Footnote-34639563
Ref: Tools/Demos<27>-Footnote-44639628
Ref: Tools/Demos<27>-Footnote-54639693
Ref: Tools/Demos<27>-Footnote-64639758
Node: C API<37>4639823
Ref: whatsnew/changelog id5024639914
Ref: 1c524639914
Ref: C API<37>-Footnote-14645772
Ref: C API<37>-Footnote-24645837
Ref: C API<37>-Footnote-34645902
Ref: C API<37>-Footnote-44645967
Ref: C API<37>-Footnote-54646032
Ref: C API<37>-Footnote-64646097
Ref: C API<37>-Footnote-74646162
Ref: C API<37>-Footnote-84646227
Ref: C API<37>-Footnote-94646292
Ref: C API<37>-Footnote-104646357
Ref: C API<37>-Footnote-114646423
Ref: C API<37>-Footnote-124646489
Ref: C API<37>-Footnote-134646555
Ref: C API<37>-Footnote-144646621
Ref: C API<37>-Footnote-154646687
Ref: C API<37>-Footnote-164646753
Ref: C API<37>-Footnote-174646819
Ref: C API<37>-Footnote-184646885
Ref: C API<37>-Footnote-194646951
Ref: C API<37>-Footnote-204647017
Ref: C API<37>-Footnote-214647060
Ref: C API<37>-Footnote-224647126
Ref: C API<37>-Footnote-234647192
Ref: C API<37>-Footnote-244647258
Ref: C API<37>-Footnote-254647301
Ref: C API<37>-Footnote-264647344
Node: Python 3 10 0 beta 14647410
Ref: whatsnew/changelog python-3-10-0-beta-14647536
Ref: 1c544647536
Node: Security<30>4648027
Ref: whatsnew/changelog id5034648127
Ref: 1c554648127
Ref: Security<30>-Footnote-14651063
Ref: Security<30>-Footnote-24651128
Ref: Security<30>-Footnote-34651193
Ref: Security<30>-Footnote-44651258
Ref: Security<30>-Footnote-54651323
Ref: Security<30>-Footnote-64651388
Ref: Security<30>-Footnote-74651453
Ref: Security<30>-Footnote-84651518
Ref: Security<30>-Footnote-94651583
Ref: Security<30>-Footnote-104651648
Ref: Security<30>-Footnote-114651714
Node: Core and Builtins<113>4651780
Ref: whatsnew/changelog id5044651901
Ref: 1c584651901
Ref: Core and Builtins<113>-Footnote-14653259
Ref: Core and Builtins<113>-Footnote-24653324
Ref: Core and Builtins<113>-Footnote-34653389
Ref: Core and Builtins<113>-Footnote-44653454
Ref: Core and Builtins<113>-Footnote-54653519
Ref: Core and Builtins<113>-Footnote-64653584
Ref: Core and Builtins<113>-Footnote-74653649
Node: Library<116>4653714
Ref: whatsnew/changelog id5054653845
Ref: 1c5a4653845
Ref: Library<116>-Footnote-14654110
Ref: Library<116>-Footnote-24654175
Node: Core and Builtins<114>4654240
Ref: whatsnew/changelog id5064654361
Ref: 1c5b4654361
Ref: Core and Builtins<114>-Footnote-14658379
Ref: Core and Builtins<114>-Footnote-24658444
Ref: Core and Builtins<114>-Footnote-34658509
Ref: Core and Builtins<114>-Footnote-44658574
Ref: Core and Builtins<114>-Footnote-54658639
Ref: Core and Builtins<114>-Footnote-64658681
Ref: Core and Builtins<114>-Footnote-74658746
Ref: Core and Builtins<114>-Footnote-84658811
Ref: Core and Builtins<114>-Footnote-94658876
Ref: Core and Builtins<114>-Footnote-104658941
Ref: Core and Builtins<114>-Footnote-114659007
Ref: Core and Builtins<114>-Footnote-124659073
Ref: Core and Builtins<114>-Footnote-134659139
Ref: Core and Builtins<114>-Footnote-144659205
Ref: Core and Builtins<114>-Footnote-154659271
Ref: Core and Builtins<114>-Footnote-164659337
Ref: Core and Builtins<114>-Footnote-174659403
Ref: Core and Builtins<114>-Footnote-184659469
Ref: Core and Builtins<114>-Footnote-194659535
Ref: Core and Builtins<114>-Footnote-204659601
Ref: Core and Builtins<114>-Footnote-214659667
Ref: Core and Builtins<114>-Footnote-224659733
Node: Library<117>4659799
Ref: whatsnew/changelog id5074659930
Ref: 1c5e4659930
Ref: Library<117>-Footnote-14660121
Node: Core and Builtins<115>4660186
Ref: whatsnew/changelog id5084660307
Ref: 1c5f4660307
Ref: Core and Builtins<115>-Footnote-14660959
Ref: Core and Builtins<115>-Footnote-24661024
Ref: Core and Builtins<115>-Footnote-34661089
Node: Library<118>4661154
Ref: whatsnew/changelog id5094661280
Ref: 1c604661280
Ref: Library<118>-Footnote-14678092
Ref: Library<118>-Footnote-24678157
Ref: Library<118>-Footnote-34678222
Ref: Library<118>-Footnote-44678287
Ref: Library<118>-Footnote-54678352
Ref: Library<118>-Footnote-64678417
Ref: Library<118>-Footnote-74678482
Ref: Library<118>-Footnote-84678547
Ref: Library<118>-Footnote-94678612
Ref: Library<118>-Footnote-104678677
Ref: Library<118>-Footnote-114678743
Ref: Library<118>-Footnote-124678809
Ref: Library<118>-Footnote-134678875
Ref: Library<118>-Footnote-144678941
Ref: Library<118>-Footnote-154679007
Ref: Library<118>-Footnote-164679073
Ref: Library<118>-Footnote-174679139
Ref: Library<118>-Footnote-184679205
Ref: Library<118>-Footnote-194679271
Ref: Library<118>-Footnote-204679337
Ref: Library<118>-Footnote-214679403
Ref: Library<118>-Footnote-224679469
Ref: Library<118>-Footnote-234679512
Ref: Library<118>-Footnote-244679578
Ref: Library<118>-Footnote-254679644
Ref: Library<118>-Footnote-264679710
Ref: Library<118>-Footnote-274679776
Ref: Library<118>-Footnote-284679842
Ref: Library<118>-Footnote-294679908
Ref: Library<118>-Footnote-304679974
Ref: Library<118>-Footnote-314680040
Ref: Library<118>-Footnote-324680106
Ref: Library<118>-Footnote-334680172
Ref: Library<118>-Footnote-344680238
Ref: Library<118>-Footnote-354680304
Ref: Library<118>-Footnote-364680370
Ref: Library<118>-Footnote-374680436
Ref: Library<118>-Footnote-384680502
Ref: Library<118>-Footnote-394680568
Ref: Library<118>-Footnote-404680634
Ref: Library<118>-Footnote-414680700
Ref: Library<118>-Footnote-424680766
Ref: Library<118>-Footnote-434680809
Ref: Library<118>-Footnote-444680875
Ref: Library<118>-Footnote-454680941
Ref: Library<118>-Footnote-464680997
Ref: Library<118>-Footnote-474681063
Ref: Library<118>-Footnote-484681129
Ref: Library<118>-Footnote-494681195
Ref: Library<118>-Footnote-504681261
Ref: Library<118>-Footnote-514681327
Ref: Library<118>-Footnote-524681393
Ref: Library<118>-Footnote-534681459
Ref: Library<118>-Footnote-544681524
Ref: Library<118>-Footnote-554681590
Ref: Library<118>-Footnote-564681656
Ref: Library<118>-Footnote-574681722
Ref: Library<118>-Footnote-584681787
Ref: Library<118>-Footnote-594681853
Ref: Library<118>-Footnote-604681919
Ref: Library<118>-Footnote-614681985
Ref: Library<118>-Footnote-624682051
Ref: Library<118>-Footnote-634682117
Ref: Library<118>-Footnote-644682183
Ref: Library<118>-Footnote-654682249
Ref: Library<118>-Footnote-664682315
Ref: Library<118>-Footnote-674682381
Ref: Library<118>-Footnote-684682447
Ref: Library<118>-Footnote-694682490
Ref: Library<118>-Footnote-704682556
Ref: Library<118>-Footnote-714682622
Ref: Library<118>-Footnote-724682688
Ref: Library<118>-Footnote-734682754
Ref: Library<118>-Footnote-744682820
Ref: Library<118>-Footnote-754682886
Ref: Library<118>-Footnote-764682952
Ref: Library<118>-Footnote-774683018
Ref: Library<118>-Footnote-784683084
Ref: Library<118>-Footnote-794683150
Ref: Library<118>-Footnote-804683216
Ref: Library<118>-Footnote-814683282
Ref: Library<118>-Footnote-824683348
Ref: Library<118>-Footnote-834683414
Node: Documentation<36>4683480
Ref: whatsnew/changelog id5104683593
Ref: 1c674683593
Ref: Documentation<36>-Footnote-14684605
Ref: Documentation<36>-Footnote-24684670
Ref: Documentation<36>-Footnote-34684735
Ref: Documentation<36>-Footnote-44684800
Ref: Documentation<36>-Footnote-54684865
Ref: Documentation<36>-Footnote-64684930
Ref: Documentation<36>-Footnote-74684995
Node: Tests<36>4685060
Ref: whatsnew/changelog id5114685170
Ref: 1c684685170
Ref: Tests<36>-Footnote-14686249
Ref: Tests<36>-Footnote-24686314
Ref: Tests<36>-Footnote-34686379
Ref: Tests<36>-Footnote-44686444
Ref: Tests<36>-Footnote-54686509
Node: Build<43>4686574
Ref: whatsnew/changelog id5124686678
Ref: 1c694686678
Ref: Build<43>-Footnote-14686940
Ref: Build<43>-Footnote-24687005
Ref: Build<43>-Footnote-34687070
Node: Windows<37>4687112
Ref: whatsnew/changelog id5134687216
Ref: 1c6a4687216
Ref: Windows<37>-Footnote-14688561
Ref: Windows<37>-Footnote-24688626
Ref: Windows<37>-Footnote-34688691
Ref: Windows<37>-Footnote-44688756
Ref: Windows<37>-Footnote-54688821
Ref: Windows<37>-Footnote-64688886
Ref: Windows<37>-Footnote-74688951
Ref: Windows<37>-Footnote-84689016
Ref: Windows<37>-Footnote-94689081
Node: macOS<27>4689146
Ref: whatsnew/changelog id5144689249
Ref: 1c6e4689249
Ref: macOS<27>-Footnote-14690555
Ref: macOS<27>-Footnote-24690620
Ref: macOS<27>-Footnote-34690685
Ref: macOS<27>-Footnote-44690750
Ref: macOS<27>-Footnote-54690815
Ref: macOS<27>-Footnote-64690880
Node: IDLE<20>4690945
Ref: whatsnew/changelog id5154691046
Ref: 1c6f4691046
Ref: IDLE<20>-Footnote-14691848
Ref: IDLE<20>-Footnote-24691913
Ref: IDLE<20>-Footnote-34691978
Ref: IDLE<20>-Footnote-44692043
Ref: IDLE<20>-Footnote-54692108
Node: C API<38>4692173
Ref: whatsnew/changelog id5164692256
Ref: 1c704692256
Ref: C API<38>-Footnote-14694505
Ref: C API<38>-Footnote-24694570
Ref: C API<38>-Footnote-34694635
Ref: C API<38>-Footnote-44694700
Ref: C API<38>-Footnote-54694765
Ref: C API<38>-Footnote-64694830
Ref: C API<38>-Footnote-74694895
Ref: C API<38>-Footnote-84694960
Ref: C API<38>-Footnote-94695025
Ref: C API<38>-Footnote-104695067
Node: Python 3 10 0 alpha 74695133
Ref: whatsnew/changelog python-3-10-0-alpha-74695259
Ref: 1c714695259
Node: Security<31>4695662
Ref: whatsnew/changelog id5174695763
Ref: 1c724695763
Ref: Security<31>-Footnote-14696847
Ref: Security<31>-Footnote-24696912
Ref: Security<31>-Footnote-34696967
Ref: Security<31>-Footnote-44697032
Node: Core and Builtins<116>4697097
Ref: whatsnew/changelog id5184697219
Ref: 1c734697219
Ref: Core and Builtins<116>-Footnote-14697839
Ref: Core and Builtins<116>-Footnote-24697904
Ref: Core and Builtins<116>-Footnote-34697969
Ref: Core and Builtins<116>-Footnote-44698034
Node: Library<119>4698099
Ref: whatsnew/changelog id5194698231
Ref: 1c744698231
Ref: Library<119>-Footnote-14698409
Node: Core and Builtins<117>4698474
Ref: whatsnew/changelog id5204698596
Ref: 1c754698596
Ref: Core and Builtins<117>-Footnote-14702485
Ref: Core and Builtins<117>-Footnote-24702550
Ref: Core and Builtins<117>-Footnote-34702615
Ref: Core and Builtins<117>-Footnote-44702680
Ref: Core and Builtins<117>-Footnote-54702722
Ref: Core and Builtins<117>-Footnote-64702787
Ref: Core and Builtins<117>-Footnote-74702852
Ref: Core and Builtins<117>-Footnote-84702917
Ref: Core and Builtins<117>-Footnote-94702982
Ref: Core and Builtins<117>-Footnote-104703047
Ref: Core and Builtins<117>-Footnote-114703113
Ref: Core and Builtins<117>-Footnote-124703179
Ref: Core and Builtins<117>-Footnote-134703245
Ref: Core and Builtins<117>-Footnote-144703311
Ref: Core and Builtins<117>-Footnote-154703377
Ref: Core and Builtins<117>-Footnote-164703443
Ref: Core and Builtins<117>-Footnote-174703509
Ref: Core and Builtins<117>-Footnote-184703552
Ref: Core and Builtins<117>-Footnote-194703618
Node: Library<120>4703684
Ref: whatsnew/changelog id5214703811
Ref: 1c764703811
Ref: Library<120>-Footnote-14711492
Ref: Library<120>-Footnote-24711557
Ref: Library<120>-Footnote-34711622
Ref: Library<120>-Footnote-44711687
Ref: Library<120>-Footnote-54711752
Ref: Library<120>-Footnote-64711817
Ref: Library<120>-Footnote-74711882
Ref: Library<120>-Footnote-84711947
Ref: Library<120>-Footnote-94712012
Ref: Library<120>-Footnote-104712077
Ref: Library<120>-Footnote-114712143
Ref: Library<120>-Footnote-124712209
Ref: Library<120>-Footnote-134712275
Ref: Library<120>-Footnote-144712341
Ref: Library<120>-Footnote-154712407
Ref: Library<120>-Footnote-164712450
Ref: Library<120>-Footnote-174712516
Ref: Library<120>-Footnote-184712582
Ref: Library<120>-Footnote-194712648
Ref: Library<120>-Footnote-204712714
Ref: Library<120>-Footnote-214712780
Ref: Library<120>-Footnote-224712846
Ref: Library<120>-Footnote-234712912
Ref: Library<120>-Footnote-244712978
Ref: Library<120>-Footnote-254713044
Ref: Library<120>-Footnote-264713126
Ref: Library<120>-Footnote-274713192
Ref: Library<120>-Footnote-284713258
Ref: Library<120>-Footnote-294713324
Ref: Library<120>-Footnote-304713390
Ref: Library<120>-Footnote-314713456
Ref: Library<120>-Footnote-324713522
Ref: Library<120>-Footnote-334713588
Ref: Library<120>-Footnote-344713654
Ref: Library<120>-Footnote-354713720
Ref: Library<120>-Footnote-364713786
Ref: Library<120>-Footnote-374713852
Ref: Library<120>-Footnote-384713918
Ref: Library<120>-Footnote-394713984
Ref: Library<120>-Footnote-404714050
Ref: Library<120>-Footnote-414714116
Ref: Library<120>-Footnote-424714182
Ref: Library<120>-Footnote-434714248
Ref: Library<120>-Footnote-444714314
Ref: Library<120>-Footnote-454714380
Node: Documentation<37>4714446
Ref: whatsnew/changelog id5224714560
Ref: 1c7e4714560
Ref: Documentation<37>-Footnote-14715255
Ref: Documentation<37>-Footnote-24715320
Ref: Documentation<37>-Footnote-34715385
Ref: Documentation<37>-Footnote-44715450
Node: Tests<37>4715515
Ref: whatsnew/changelog id5234715626
Ref: 1c7f4715626
Ref: Tests<37>-Footnote-14715931
Ref: Tests<37>-Footnote-24715996
Node: Build<44>4716061
Ref: whatsnew/changelog id5244716166
Ref: 1c804716166
Ref: Build<44>-Footnote-14717137
Ref: Build<44>-Footnote-24717202
Ref: Build<44>-Footnote-34717267
Ref: Build<44>-Footnote-44717332
Ref: Build<44>-Footnote-54717397
Ref: Build<44>-Footnote-64717462
Node: Windows<38>4717527
Ref: whatsnew/changelog id5254717631
Ref: 1c814717631
Ref: Windows<38>-Footnote-14717821
Node: IDLE<21>4717886
Ref: whatsnew/changelog id5264717990
Ref: 1c824717990
Ref: IDLE<21>-Footnote-14718233
Node: C API<39>4718298
Ref: whatsnew/changelog id5274718382
Ref: 1c834718382
Ref: C API<39>-Footnote-14721848
Ref: C API<39>-Footnote-24721913
Ref: C API<39>-Footnote-34721978
Ref: C API<39>-Footnote-44722043
Ref: C API<39>-Footnote-54722108
Ref: C API<39>-Footnote-64722173
Ref: C API<39>-Footnote-74722238
Ref: C API<39>-Footnote-84722303
Ref: C API<39>-Footnote-94722368
Node: Python 3 10 0 alpha 64722410
Ref: whatsnew/changelog python-3-10-0-alpha-64722537
Ref: 1c844722537
Node: Security<32>4723030
Ref: whatsnew/changelog id5284723131
Ref: 1c854723131
Ref: Security<32>-Footnote-14723377
Node: Core and Builtins<118>4723442
Ref: whatsnew/changelog id5294723564
Ref: 1c864723564
Ref: Core and Builtins<118>-Footnote-14725209
Ref: Core and Builtins<118>-Footnote-24725274
Ref: Core and Builtins<118>-Footnote-34725339
Ref: Core and Builtins<118>-Footnote-44725381
Ref: Core and Builtins<118>-Footnote-54725446
Ref: Core and Builtins<118>-Footnote-64725511
Ref: Core and Builtins<118>-Footnote-74725576
Ref: Core and Builtins<118>-Footnote-84725641
Node: Library<121>4725706
Ref: whatsnew/changelog id5304725838
Ref: 1c874725838
Ref: Library<121>-Footnote-14726538
Node: Core and Builtins<119>4726603
Ref: whatsnew/changelog id5314726725
Ref: 1c884726725
Ref: Core and Builtins<119>-Footnote-14727417
Ref: Core and Builtins<119>-Footnote-24727482
Ref: Core and Builtins<119>-Footnote-34727547
Ref: Core and Builtins<119>-Footnote-44727612
Ref: Core and Builtins<119>-Footnote-54727677
Node: Library<122>4727719
Ref: whatsnew/changelog id5324727851
Ref: 1c894727851
Ref: Library<122>-Footnote-14728261
Node: Core and Builtins<120>4728326
Ref: whatsnew/changelog id5334728448
Ref: 1c8a4728448
Ref: Core and Builtins<120>-Footnote-14728761
Node: Library<123>4728826
Ref: whatsnew/changelog id5344728953
Ref: 1c8b4728953
Ref: Library<123>-Footnote-14731789
Ref: Library<123>-Footnote-24731854
Ref: Library<123>-Footnote-34731919
Ref: Library<123>-Footnote-44731984
Ref: Library<123>-Footnote-54732049
Ref: Library<123>-Footnote-64732114
Ref: Library<123>-Footnote-74732179
Ref: Library<123>-Footnote-84732244
Ref: Library<123>-Footnote-94732309
Ref: Library<123>-Footnote-104732374
Ref: Library<123>-Footnote-114732440
Ref: Library<123>-Footnote-124732506
Ref: Library<123>-Footnote-134732572
Ref: Library<123>-Footnote-144732638
Ref: Library<123>-Footnote-154732704
Ref: Library<123>-Footnote-164732770
Node: Documentation<38>4732836
Ref: whatsnew/changelog id5354732950
Ref: 1c8f4732950
Ref: Documentation<38>-Footnote-14733300
Ref: Documentation<38>-Footnote-24733365
Ref: Documentation<38>-Footnote-34733430
Node: Tests<38>4733472
Ref: whatsnew/changelog id5364733583
Ref: 1c904733583
Ref: Tests<38>-Footnote-14733774
Node: Build<45>4733839
Ref: whatsnew/changelog id5374733944
Ref: 1c914733944
Ref: Build<45>-Footnote-14735013
Ref: Build<45>-Footnote-24735078
Ref: Build<45>-Footnote-34735143
Ref: Build<45>-Footnote-44735208
Ref: Build<45>-Footnote-54735273
Node: Windows<39>4735338
Ref: whatsnew/changelog id5384735443
Ref: 1c924735443
Ref: Windows<39>-Footnote-14735609
Node: macOS<28>4735674
Ref: whatsnew/changelog id5394735778
Ref: 1c944735778
Ref: macOS<28>-Footnote-14735921
Node: IDLE<22>4735986
Ref: whatsnew/changelog id5404736088
Ref: 1c954736088
Ref: IDLE<22>-Footnote-14736360
Node: C API<40>4736425
Ref: whatsnew/changelog id5414736509
Ref: 1c964736509
Ref: C API<40>-Footnote-14738263
Ref: C API<40>-Footnote-24738328
Ref: C API<40>-Footnote-34738393
Ref: C API<40>-Footnote-44738458
Ref: C API<40>-Footnote-54738523
Ref: C API<40>-Footnote-64738588
Ref: C API<40>-Footnote-74738653
Ref: C API<40>-Footnote-84738718
Ref: C API<40>-Footnote-94738783
Node: Python 3 10 0 alpha 54738848
Ref: whatsnew/changelog python-3-10-0-alpha-54738975
Ref: 1c9e4738975
Node: Security<33>4739398
Ref: whatsnew/changelog id5424739499
Ref: 1c9f4739499
Ref: Security<33>-Footnote-14739721
Node: Core and Builtins<121>4739786
Ref: whatsnew/changelog id5434739908
Ref: 1ca24739908
Ref: Core and Builtins<121>-Footnote-14742036
Ref: Core and Builtins<121>-Footnote-24742101
Ref: Core and Builtins<121>-Footnote-34742166
Ref: Core and Builtins<121>-Footnote-44742231
Ref: Core and Builtins<121>-Footnote-54742296
Ref: Core and Builtins<121>-Footnote-64742361
Ref: Core and Builtins<121>-Footnote-74742426
Ref: Core and Builtins<121>-Footnote-84742491
Ref: Core and Builtins<121>-Footnote-94742556
Ref: Core and Builtins<121>-Footnote-104742621
Ref: Core and Builtins<121>-Footnote-114742687
Ref: Core and Builtins<121>-Footnote-124742753
Node: Library<124>4742819
Ref: whatsnew/changelog id5444742951
Ref: 1ca34742951
Ref: Library<124>-Footnote-14743164
Node: Core and Builtins<122>4743229
Ref: whatsnew/changelog id5454743351
Ref: 1ca44743351
Ref: Core and Builtins<122>-Footnote-14743690
Ref: Core and Builtins<122>-Footnote-24743755
Node: Library<125>4743820
Ref: whatsnew/changelog id5464743947
Ref: 1ca54743947
Ref: Library<125>-Footnote-14748893
Ref: Library<125>-Footnote-24748958
Ref: Library<125>-Footnote-34749023
Ref: Library<125>-Footnote-44749088
Ref: Library<125>-Footnote-54749153
Ref: Library<125>-Footnote-64749218
Ref: Library<125>-Footnote-74749283
Ref: Library<125>-Footnote-84749348
Ref: Library<125>-Footnote-94749413
Ref: Library<125>-Footnote-104749478
Ref: Library<125>-Footnote-114749544
Ref: Library<125>-Footnote-124749610
Ref: Library<125>-Footnote-134749676
Ref: Library<125>-Footnote-144749742
Ref: Library<125>-Footnote-154749808
Ref: Library<125>-Footnote-164749874
Ref: Library<125>-Footnote-174749940
Ref: Library<125>-Footnote-184750006
Ref: Library<125>-Footnote-194750049
Ref: Library<125>-Footnote-204750115
Ref: Library<125>-Footnote-214750181
Ref: Library<125>-Footnote-224750247
Ref: Library<125>-Footnote-234750313
Ref: Library<125>-Footnote-244750381
Ref: Library<125>-Footnote-254750424
Ref: Library<125>-Footnote-264750490
Ref: Library<125>-Footnote-274750556
Ref: Library<125>-Footnote-284750622
Ref: Library<125>-Footnote-294750688
Ref: Library<125>-Footnote-304750754
Ref: Library<125>-Footnote-314750820
Ref: Library<125>-Footnote-324750886
Ref: Library<125>-Footnote-334750952
Ref: Library<125>-Footnote-344751018
Node: Documentation<39>4751084
Ref: whatsnew/changelog id5474751198
Ref: 1ca64751198
Ref: Documentation<39>-Footnote-14751526
Ref: Documentation<39>-Footnote-24751591
Node: Tests<39>4751656
Ref: whatsnew/changelog id5484751767
Ref: 1ca74751767
Ref: Tests<39>-Footnote-14752123
Ref: Tests<39>-Footnote-24752188
Node: Build<46>4752253
Ref: whatsnew/changelog id5494752358
Ref: 1ca84752358
Ref: Build<46>-Footnote-14753553
Ref: Build<46>-Footnote-24753618
Ref: Build<46>-Footnote-34753683
Ref: Build<46>-Footnote-44753748
Ref: Build<46>-Footnote-54753813
Node: Windows<40>4753878
Ref: whatsnew/changelog id5504753983
Ref: 1ca94753983
Ref: Windows<40>-Footnote-14754196
Ref: Windows<40>-Footnote-24754261
Node: macOS<29>4754326
Ref: whatsnew/changelog id5514754430
Ref: 1caa4754430
Ref: macOS<29>-Footnote-14754683
Node: IDLE<23>4754748
Ref: whatsnew/changelog id5524754850
Ref: 1cab4754850
Ref: IDLE<23>-Footnote-14755414
Ref: IDLE<23>-Footnote-24755479
Ref: IDLE<23>-Footnote-34755544
Ref: IDLE<23>-Footnote-44755609
Node: C API<41>4755674
Ref: whatsnew/changelog id5534755758
Ref: 1cac4755758
Ref: C API<41>-Footnote-14756364
Ref: C API<41>-Footnote-24756429
Node: Python 3 10 0 alpha 44756494
Ref: whatsnew/changelog python-3-10-0-alpha-44756621
Ref: 1cae4756621
Node: Core and Builtins<123>4757078
Ref: whatsnew/changelog id5544757179
Ref: 1caf4757179
Ref: Core and Builtins<123>-Footnote-14758651
Ref: Core and Builtins<123>-Footnote-24758716
Ref: Core and Builtins<123>-Footnote-34758781
Ref: Core and Builtins<123>-Footnote-44758846
Ref: Core and Builtins<123>-Footnote-54758911
Ref: Core and Builtins<123>-Footnote-64758976
Ref: Core and Builtins<123>-Footnote-74759041
Ref: Core and Builtins<123>-Footnote-84759106
Ref: Core and Builtins<123>-Footnote-94759171
Ref: Core and Builtins<123>-Footnote-104759236
Node: Library<126>4759302
Ref: whatsnew/changelog id5554759434
Ref: 1cb04759434
Ref: Library<126>-Footnote-14759703
Node: Core and Builtins<124>4759768
Ref: whatsnew/changelog id5564759890
Ref: 1cb14759890
Ref: Core and Builtins<124>-Footnote-14760167
Node: Library<127>4760232
Ref: whatsnew/changelog id5574760364
Ref: 1cb34760364
Ref: Library<127>-Footnote-14761630
Ref: Library<127>-Footnote-24761695
Ref: Library<127>-Footnote-34761737
Ref: Library<127>-Footnote-44761802
Ref: Library<127>-Footnote-54761867
Ref: Library<127>-Footnote-64761932
Ref: Library<127>-Footnote-74761999
Node: Core and Builtins<125>4762041
Ref: whatsnew/changelog id5584762163
Ref: 1cb44762163
Ref: Core and Builtins<125>-Footnote-14762618
Ref: Core and Builtins<125>-Footnote-24762683
Node: Library<128>4762748
Ref: whatsnew/changelog id5594762875
Ref: 1cb54762875
Ref: Library<128>-Footnote-14771700
Ref: Library<128>-Footnote-24771765
Ref: Library<128>-Footnote-34771830
Ref: Library<128>-Footnote-44771895
Ref: Library<128>-Footnote-54771960
Ref: Library<128>-Footnote-64772025
Ref: Library<128>-Footnote-74772090
Ref: Library<128>-Footnote-84772132
Ref: Library<128>-Footnote-94772174
Ref: Library<128>-Footnote-104772239
Ref: Library<128>-Footnote-114772305
Ref: Library<128>-Footnote-124772371
Ref: Library<128>-Footnote-134772437
Ref: Library<128>-Footnote-144772503
Ref: Library<128>-Footnote-154772569
Ref: Library<128>-Footnote-164772635
Ref: Library<128>-Footnote-174772701
Ref: Library<128>-Footnote-184772767
Ref: Library<128>-Footnote-194772832
Ref: Library<128>-Footnote-204772900
Ref: Library<128>-Footnote-214772943
Ref: Library<128>-Footnote-224773009
Ref: Library<128>-Footnote-234773075
Ref: Library<128>-Footnote-244773141
Ref: Library<128>-Footnote-254773207
Ref: Library<128>-Footnote-264773273
Ref: Library<128>-Footnote-274773339
Ref: Library<128>-Footnote-284773405
Ref: Library<128>-Footnote-294773471
Ref: Library<128>-Footnote-304773537
Ref: Library<128>-Footnote-314773603
Ref: Library<128>-Footnote-324773669
Ref: Library<128>-Footnote-334773712
Ref: Library<128>-Footnote-344773778
Ref: Library<128>-Footnote-354773844
Ref: Library<128>-Footnote-364773910
Ref: Library<128>-Footnote-374773976
Ref: Library<128>-Footnote-384774042
Ref: Library<128>-Footnote-394774108
Ref: Library<128>-Footnote-404774174
Ref: Library<128>-Footnote-414774240
Ref: Library<128>-Footnote-424774306
Ref: Library<128>-Footnote-434774372
Ref: Library<128>-Footnote-444774438
Ref: Library<128>-Footnote-454774504
Ref: Library<128>-Footnote-464774570
Ref: Library<128>-Footnote-474774636
Ref: Library<128>-Footnote-484774704
Ref: Library<128>-Footnote-494774747
Ref: Library<128>-Footnote-504774813
Ref: Library<128>-Footnote-514774879
Ref: Library<128>-Footnote-524774945
Ref: Library<128>-Footnote-534775011
Ref: Library<128>-Footnote-544775077
Ref: Library<128>-Footnote-554775143
Ref: Library<128>-Footnote-564775209
Ref: Library<128>-Footnote-574775275
Ref: Library<128>-Footnote-584775341
Node: Documentation<40>4775407
Ref: whatsnew/changelog id5604775521
Ref: 1cbb4775521
Ref: Documentation<40>-Footnote-14775837
Ref: Documentation<40>-Footnote-24775902
Node: Tests<40>4775967
Ref: whatsnew/changelog id5614776078
Ref: 1cbd4776078
Ref: Tests<40>-Footnote-14776855
Ref: Tests<40>-Footnote-24776920
Ref: Tests<40>-Footnote-34776985
Ref: Tests<40>-Footnote-44777050
Ref: Tests<40>-Footnote-54777115
Ref: Tests<40>-Footnote-64777180
Ref: Tests<40>-Footnote-74777245
Ref: Tests<40>-Footnote-84777310
Node: Build<47>4777375
Ref: whatsnew/changelog id5624777478
Ref: 1cbe4777478
Ref: Build<47>-Footnote-14778457
Ref: Build<47>-Footnote-24778522
Ref: Build<47>-Footnote-34778587
Ref: Build<47>-Footnote-44778652
Ref: Build<47>-Footnote-54778717
Ref: Build<47>-Footnote-64778782
Node: macOS<30>4778847
Ref: whatsnew/changelog id5634778956
Ref: 1cbf4778956
Ref: macOS<30>-Footnote-14779276
Ref: macOS<30>-Footnote-24779341
Ref: macOS<30>-Footnote-34779406
Node: Tools/Demos<28>4779471
Ref: whatsnew/changelog id5644779580
Ref: 1cc04779580
Ref: Tools/Demos<28>-Footnote-14779906
Ref: Tools/Demos<28>-Footnote-24779971
Node: C API<42>4780036
Ref: whatsnew/changelog id5654780127
Ref: 1cc14780127
Ref: C API<42>-Footnote-14780970
Ref: C API<42>-Footnote-24781035
Ref: C API<42>-Footnote-34781100
Ref: C API<42>-Footnote-44781167
Ref: C API<42>-Footnote-54781232
Node: Python 3 10 0 alpha 34781297
Ref: whatsnew/changelog python-3-10-0-alpha-34781424
Ref: 1cc24781424
Node: Security<34>4782019
Ref: whatsnew/changelog id5664782120
Ref: 1cc34782120
Ref: Security<34>-Footnote-14782360
Node: Core and Builtins<126>4782425
Ref: whatsnew/changelog id5674782547
Ref: 1cc44782547
Ref: Core and Builtins<126>-Footnote-14784165
Ref: Core and Builtins<126>-Footnote-24784230
Ref: Core and Builtins<126>-Footnote-34784295
Ref: Core and Builtins<126>-Footnote-44784360
Ref: Core and Builtins<126>-Footnote-54784425
Node: Library<129>4784490
Ref: whatsnew/changelog id5684784622
Ref: 1cc64784622
Ref: Library<129>-Footnote-14784848
Ref: Library<129>-Footnote-24784915
Node: Core and Builtins<127>4784957
Ref: whatsnew/changelog id5694785079
Ref: 1cc74785079
Ref: Core and Builtins<127>-Footnote-14786922
Ref: Core and Builtins<127>-Footnote-24786987
Ref: Core and Builtins<127>-Footnote-34787052
Ref: Core and Builtins<127>-Footnote-44787117
Ref: Core and Builtins<127>-Footnote-54787182
Ref: Core and Builtins<127>-Footnote-64787247
Ref: Core and Builtins<127>-Footnote-74787312
Ref: Core and Builtins<127>-Footnote-84787377
Ref: Core and Builtins<127>-Footnote-94787442
Ref: Core and Builtins<127>-Footnote-104787507
Node: Library<130>4787573
Ref: whatsnew/changelog id5704787705
Ref: 1cc84787705
Ref: Library<130>-Footnote-14787842
Node: Core and Builtins<128>4787907
Ref: whatsnew/changelog id5714788029
Ref: 1cc94788029
Ref: Core and Builtins<128>-Footnote-14788255
Node: Library<131>4788320
Ref: whatsnew/changelog id5724788452
Ref: 1cca4788452
Ref: Library<131>-Footnote-14788588
Node: Core and Builtins<129>4788653
Ref: whatsnew/changelog id5734788775
Ref: 1ccb4788775
Ref: Core and Builtins<129>-Footnote-14789360
Ref: Core and Builtins<129>-Footnote-24789425
Ref: Core and Builtins<129>-Footnote-34789490
Node: Library<132>4789555
Ref: whatsnew/changelog id5744789682
Ref: 1ccc4789682
Ref: Library<132>-Footnote-14800754
Ref: Library<132>-Footnote-24800818
Ref: Library<132>-Footnote-34800883
Ref: Library<132>-Footnote-44800948
Ref: Library<132>-Footnote-54801013
Ref: Library<132>-Footnote-64801078
Ref: Library<132>-Footnote-74801143
Ref: Library<132>-Footnote-84801208
Ref: Library<132>-Footnote-94801273
Ref: Library<132>-Footnote-104801338
Ref: Library<132>-Footnote-114801404
Ref: Library<132>-Footnote-124801470
Ref: Library<132>-Footnote-134801536
Ref: Library<132>-Footnote-144801602
Ref: Library<132>-Footnote-154801668
Ref: Library<132>-Footnote-164801734
Ref: Library<132>-Footnote-174801800
Ref: Library<132>-Footnote-184801866
Ref: Library<132>-Footnote-194801932
Ref: Library<132>-Footnote-204801998
Ref: Library<132>-Footnote-214802064
Ref: Library<132>-Footnote-224802130
Ref: Library<132>-Footnote-234802196
Ref: Library<132>-Footnote-244802264
Ref: Library<132>-Footnote-254802330
Ref: Library<132>-Footnote-264802396
Ref: Library<132>-Footnote-274802439
Ref: Library<132>-Footnote-284802505
Ref: Library<132>-Footnote-294802571
Ref: Library<132>-Footnote-304802637
Ref: Library<132>-Footnote-314802703
Ref: Library<132>-Footnote-324802769
Ref: Library<132>-Footnote-334802835
Ref: Library<132>-Footnote-344802901
Ref: Library<132>-Footnote-354802967
Ref: Library<132>-Footnote-364803033
Ref: Library<132>-Footnote-374803099
Ref: Library<132>-Footnote-384803165
Ref: Library<132>-Footnote-394803231
Ref: Library<132>-Footnote-404803297
Ref: Library<132>-Footnote-414803363
Ref: Library<132>-Footnote-424803429
Ref: Library<132>-Footnote-434803495
Ref: Library<132>-Footnote-444803561
Ref: Library<132>-Footnote-454803627
Ref: Library<132>-Footnote-464803693
Ref: Library<132>-Footnote-474803759
Ref: Library<132>-Footnote-484803825
Ref: Library<132>-Footnote-494803891
Ref: Library<132>-Footnote-504803957
Ref: Library<132>-Footnote-514804023
Ref: Library<132>-Footnote-524804089
Ref: Library<132>-Footnote-534804155
Ref: Library<132>-Footnote-544804221
Ref: Library<132>-Footnote-554804287
Ref: Library<132>-Footnote-564804353
Ref: Library<132>-Footnote-574804419
Ref: Library<132>-Footnote-584804485
Ref: Library<132>-Footnote-594804551
Ref: Library<132>-Footnote-604804617
Ref: Library<132>-Footnote-614804683
Ref: Library<132>-Footnote-624804749
Ref: Library<132>-Footnote-634804815
Ref: Library<132>-Footnote-644804881
Ref: Library<132>-Footnote-654804947
Node: Documentation<41>4805013
Ref: whatsnew/changelog id5754805127
Ref: 1cd14805127
Ref: Documentation<41>-Footnote-14805595
Ref: Documentation<41>-Footnote-24805660
Ref: Documentation<41>-Footnote-34805725
Node: Tests<41>4805790
Ref: whatsnew/changelog id5764805901
Ref: 1cd24805901
Ref: Tests<41>-Footnote-14807111
Ref: Tests<41>-Footnote-24807176
Ref: Tests<41>-Footnote-34807241
Ref: Tests<41>-Footnote-44807306
Ref: Tests<41>-Footnote-54807371
Ref: Tests<41>-Footnote-64807436
Ref: Tests<41>-Footnote-74807501
Ref: Tests<41>-Footnote-84807566
Ref: Tests<41>-Footnote-94807631
Ref: Tests<41>-Footnote-104807696
Ref: Tests<41>-Footnote-114807762
Ref: Tests<41>-Footnote-124807828
Node: Build<48>4807894
Ref: whatsnew/changelog id5774807999
Ref: 1cd34807999
Ref: Build<48>-Footnote-14809140
Ref: Build<48>-Footnote-24809205
Ref: Build<48>-Footnote-34809270
Ref: Build<48>-Footnote-44809335
Ref: Build<48>-Footnote-54809400
Ref: Build<48>-Footnote-64809465
Ref: Build<48>-Footnote-74809530
Node: Windows<41>4809595
Ref: whatsnew/changelog id5784809700
Ref: 1cd44809700
Ref: Windows<41>-Footnote-14809994
Ref: Windows<41>-Footnote-24810059
Node: macOS<31>4810124
Ref: whatsnew/changelog id5794810228
Ref: 1cd54810228
Ref: macOS<31>-Footnote-14811174
Ref: macOS<31>-Footnote-24811239
Ref: macOS<31>-Footnote-34811304
Ref: macOS<31>-Footnote-44811369
Ref: macOS<31>-Footnote-54811434
Node: IDLE<24>4811499
Ref: whatsnew/changelog id5804811607
Ref: 1cd64811607
Ref: IDLE<24>-Footnote-14812029
Ref: IDLE<24>-Footnote-24812094
Ref: IDLE<24>-Footnote-34812159
Node: Tools/Demos<29>4812224
Ref: whatsnew/changelog id5814812332
Ref: 1cd74812332
Ref: Tools/Demos<29>-Footnote-14812734
Ref: Tools/Demos<29>-Footnote-24812799
Node: C API<43>4812864
Ref: whatsnew/changelog id5824812955
Ref: 1cd84812955
Ref: C API<43>-Footnote-14817727
Ref: C API<43>-Footnote-24817792
Ref: C API<43>-Footnote-34817859
Ref: C API<43>-Footnote-44817901
Ref: C API<43>-Footnote-54817968
Ref: C API<43>-Footnote-64818010
Ref: C API<43>-Footnote-74818077
Ref: C API<43>-Footnote-84818119
Ref: C API<43>-Footnote-94818186
Ref: C API<43>-Footnote-104818228
Ref: C API<43>-Footnote-114818296
Ref: C API<43>-Footnote-124818339
Ref: C API<43>-Footnote-134818407
Ref: C API<43>-Footnote-144818450
Ref: C API<43>-Footnote-154818518
Ref: C API<43>-Footnote-164818561
Ref: C API<43>-Footnote-174818627
Ref: C API<43>-Footnote-184818695
Ref: C API<43>-Footnote-194818738
Ref: C API<43>-Footnote-204818806
Ref: C API<43>-Footnote-214818849
Ref: C API<43>-Footnote-224818917
Ref: C API<43>-Footnote-234818960
Ref: C API<43>-Footnote-244819028
Ref: C API<43>-Footnote-254819071
Ref: C API<43>-Footnote-264819137
Ref: C API<43>-Footnote-274819203
Ref: C API<43>-Footnote-284819269
Ref: C API<43>-Footnote-294819335
Ref: C API<43>-Footnote-304819401
Ref: C API<43>-Footnote-314819467
Ref: C API<43>-Footnote-324819533
Ref: C API<43>-Footnote-334819601
Ref: C API<43>-Footnote-344819667
Ref: C API<43>-Footnote-354819733
Ref: C API<43>-Footnote-364819799
Node: Python 3 10 0 alpha 24819865
Ref: whatsnew/changelog python-3-10-0-alpha-24819992
Ref: 1cda4819992
Node: Security<35>4820415
Ref: whatsnew/changelog id5834820516
Ref: 1cdb4820516
Ref: Security<35>-Footnote-14820992
Ref: Security<35>-Footnote-24821057
Node: Core and Builtins<130>4821122
Ref: whatsnew/changelog id5844821244
Ref: 1cdc4821244
Ref: Core and Builtins<130>-Footnote-14824597
Ref: Core and Builtins<130>-Footnote-24824662
Ref: Core and Builtins<130>-Footnote-34824727
Ref: Core and Builtins<130>-Footnote-44824792
Ref: Core and Builtins<130>-Footnote-54824857
Ref: Core and Builtins<130>-Footnote-64824922
Ref: Core and Builtins<130>-Footnote-74824987
Ref: Core and Builtins<130>-Footnote-84825052
Ref: Core and Builtins<130>-Footnote-94825117
Ref: Core and Builtins<130>-Footnote-104825182
Ref: Core and Builtins<130>-Footnote-114825248
Ref: Core and Builtins<130>-Footnote-124825314
Ref: Core and Builtins<130>-Footnote-134825380
Ref: Core and Builtins<130>-Footnote-144825446
Ref: Core and Builtins<130>-Footnote-154825512
Ref: Core and Builtins<130>-Footnote-164825578
Ref: Core and Builtins<130>-Footnote-174825644
Ref: Core and Builtins<130>-Footnote-184825710
Node: Library<133>4825776
Ref: whatsnew/changelog id5854825908
Ref: 1cdf4825908
Ref: Library<133>-Footnote-14826214
Node: Core and Builtins<131>4826279
Ref: whatsnew/changelog id5864826401
Ref: 1ce04826401
Ref: Core and Builtins<131>-Footnote-14826735
Ref: Core and Builtins<131>-Footnote-24826800
Node: Library<134>4826842
Ref: whatsnew/changelog id5874826969
Ref: 1ce14826969
Ref: Library<134>-Footnote-14834006
Ref: Library<134>-Footnote-24834071
Ref: Library<134>-Footnote-34834136
Ref: Library<134>-Footnote-44834201
Ref: Library<134>-Footnote-54834266
Ref: Library<134>-Footnote-64834331
Ref: Library<134>-Footnote-74834396
Ref: Library<134>-Footnote-84834438
Ref: Library<134>-Footnote-94834503
Ref: Library<134>-Footnote-104834568
Ref: Library<134>-Footnote-114834634
Ref: Library<134>-Footnote-124834700
Ref: Library<134>-Footnote-134834766
Ref: Library<134>-Footnote-144834832
Ref: Library<134>-Footnote-154834898
Ref: Library<134>-Footnote-164834964
Ref: Library<134>-Footnote-174835030
Ref: Library<134>-Footnote-184835096
Ref: Library<134>-Footnote-194835162
Ref: Library<134>-Footnote-204835228
Ref: Library<134>-Footnote-214835294
Ref: Library<134>-Footnote-224835360
Ref: Library<134>-Footnote-234835426
Ref: Library<134>-Footnote-244835492
Ref: Library<134>-Footnote-254835558
Ref: Library<134>-Footnote-264835601
Ref: Library<134>-Footnote-274835667
Ref: Library<134>-Footnote-284835733
Ref: Library<134>-Footnote-294835799
Ref: Library<134>-Footnote-304835865
Ref: Library<134>-Footnote-314835931
Ref: Library<134>-Footnote-324835997
Ref: Library<134>-Footnote-334836063
Ref: Library<134>-Footnote-344836129
Ref: Library<134>-Footnote-354836195
Ref: Library<134>-Footnote-364836261
Ref: Library<134>-Footnote-374836326
Ref: Library<134>-Footnote-384836392
Ref: Library<134>-Footnote-394836458
Ref: Library<134>-Footnote-404836524
Ref: Library<134>-Footnote-414836590
Node: Documentation<42>4836656
Ref: whatsnew/changelog id5884836770
Ref: 1ce44836770
Ref: Documentation<42>-Footnote-14837620
Ref: Documentation<42>-Footnote-24837685
Ref: Documentation<42>-Footnote-34837750
Ref: Documentation<42>-Footnote-44837815
Ref: Documentation<42>-Footnote-54837880
Ref: Documentation<42>-Footnote-64837945
Node: Tests<42>4838010
Ref: whatsnew/changelog id5894838121
Ref: 1ce74838121
Ref: Tests<42>-Footnote-14838758
Ref: Tests<42>-Footnote-24838823
Ref: Tests<42>-Footnote-34838888
Ref: Tests<42>-Footnote-44838953
Node: Build<49>4839018
Ref: whatsnew/changelog id5904839123
Ref: 1ce84839123
Ref: Build<49>-Footnote-14839387
Node: Windows<42>4839452
Ref: whatsnew/changelog id5914839557
Ref: 1ce94839557
Ref: Windows<42>-Footnote-14840033
Ref: Windows<42>-Footnote-24840098
Ref: Windows<42>-Footnote-34840163
Ref: Windows<42>-Footnote-44840228
Ref: Windows<42>-Footnote-54840293
Node: macOS<32>4840358
Ref: whatsnew/changelog id5924840462
Ref: 1cea4840462
Ref: macOS<32>-Footnote-14840614
Node: IDLE<25>4840679
Ref: whatsnew/changelog id5934840781
Ref: 1ceb4840781
Ref: IDLE<25>-Footnote-14841394
Ref: IDLE<25>-Footnote-24841459
Ref: IDLE<25>-Footnote-34841524
Node: C API<44>4841589
Ref: whatsnew/changelog id5944841673
Ref: 1cec4841673
Ref: C API<44>-Footnote-14843008
Ref: C API<44>-Footnote-24843073
Ref: C API<44>-Footnote-34843138
Ref: C API<44>-Footnote-44843203
Ref: C API<44>-Footnote-54843268
Ref: C API<44>-Footnote-64843333
Ref: C API<44>-Footnote-74843398
Ref: C API<44>-Footnote-84843463
Node: Python 3 10 0 alpha 14843528
Ref: whatsnew/changelog python-3-10-0-alpha-14843653
Ref: 1cee4843653
Node: Security<36>4844986
Ref: whatsnew/changelog id5954845087
Ref: 1cef4845087
Ref: Security<36>-Footnote-14845990
Ref: Security<36>-Footnote-24846055
Ref: Security<36>-Footnote-34846120
Ref: Security<36>-Footnote-44846176
Ref: Security<36>-Footnote-54846241
Ref: Security<36>-Footnote-64846306
Ref: Security<36>-Footnote-74846362
Ref: Security<36>-Footnote-84846427
Node: Core and Builtins<132>4846492
Ref: whatsnew/changelog id5964846614
Ref: 1cf04846614
Ref: Core and Builtins<132>-Footnote-14847306
Ref: Core and Builtins<132>-Footnote-24847371
Ref: Core and Builtins<132>-Footnote-34847436
Ref: Core and Builtins<132>-Footnote-44847478
Ref: Core and Builtins<132>-Footnote-54847543
Ref: Core and Builtins<132>-Footnote-64847608
Node: Library<135>4847650
Ref: whatsnew/changelog id5974847782
Ref: 1cf14847782
Ref: Library<135>-Footnote-14847965
Ref: Library<135>-Footnote-24848032
Node: Core and Builtins<133>4848074
Ref: whatsnew/changelog id5984848196
Ref: 1cf24848196
Ref: Core and Builtins<133>-Footnote-14848588
Ref: Core and Builtins<133>-Footnote-24848653
Node: Library<136>4848718
Ref: whatsnew/changelog id5994848850
Ref: 1cf34848850
Ref: Library<136>-Footnote-14849471
Ref: Library<136>-Footnote-24849538
Ref: Library<136>-Footnote-34849580
Ref: Library<136>-Footnote-44849647
Ref: Library<136>-Footnote-54849689
Ref: Library<136>-Footnote-64849756
Ref: Library<136>-Footnote-74849798
Ref: Library<136>-Footnote-84849865
Ref: Library<136>-Footnote-94849907
Node: Core and Builtins<134>4849974
Ref: whatsnew/changelog id6004850096
Ref: 1cf44850096
Ref: Core and Builtins<134>-Footnote-14850355
Node: Library<137>4850420
Ref: whatsnew/changelog id6014850552
Ref: 1cf54850552
Ref: Library<137>-Footnote-14850971
Ref: Library<137>-Footnote-24851038
Ref: Library<137>-Footnote-34851080
Ref: Library<137>-Footnote-44851147
Ref: Library<137>-Footnote-54851189
Ref: Library<137>-Footnote-64851256
Node: Core and Builtins<135>4851298
Ref: whatsnew/changelog id6024851420
Ref: 1cf64851420
Ref: Core and Builtins<135>-Footnote-14851674
Node: Library<138>4851739
Ref: whatsnew/changelog id6034851871
Ref: 1cf74851871
Ref: Library<138>-Footnote-14852171
Node: Core and Builtins<136>4852236
Ref: whatsnew/changelog id6044852358
Ref: 1cf84852358
Ref: Core and Builtins<136>-Footnote-14852801
Ref: Core and Builtins<136>-Footnote-24852866
Node: Library<139>4852931
Ref: whatsnew/changelog id6054853063
Ref: 1cf94853063
Ref: Library<139>-Footnote-14853253
Ref: Library<139>-Footnote-24853320
Node: Core and Builtins<137>4853362
Ref: whatsnew/changelog id6064853484
Ref: 1cfa4853484
Ref: Core and Builtins<137>-Footnote-14853956
Node: Library<140>4854021
Ref: whatsnew/changelog id6074854153
Ref: 1cfb4854153
Ref: Library<140>-Footnote-14854314
Node: Core and Builtins<138>4854379
Ref: whatsnew/changelog id6084854501
Ref: 1cfc4854501
Ref: Core and Builtins<138>-Footnote-14854698
Node: Library<141>4854765
Ref: whatsnew/changelog id6094854897
Ref: 1cfd4854897
Ref: Library<141>-Footnote-14855092
Ref: Library<141>-Footnote-24855159
Node: Core and Builtins<139>4855201
Ref: whatsnew/changelog id6104855323
Ref: 1cfe4855323
Ref: Core and Builtins<139>-Footnote-14855799
Ref: Core and Builtins<139>-Footnote-24855864
Ref: Core and Builtins<139>-Footnote-34855929
Node: Library<142>4855994
Ref: whatsnew/changelog id6114856126
Ref: 1cff4856126
Ref: Library<142>-Footnote-14856347
Ref: Library<142>-Footnote-24856414
Node: Core and Builtins<140>4856456
Ref: whatsnew/changelog id6124856578
Ref: 1d004856578
Ref: Core and Builtins<140>-Footnote-14858034
Ref: Core and Builtins<140>-Footnote-24858099
Ref: Core and Builtins<140>-Footnote-34858164
Ref: Core and Builtins<140>-Footnote-44858229
Ref: Core and Builtins<140>-Footnote-54858294
Ref: Core and Builtins<140>-Footnote-64858359
Ref: Core and Builtins<140>-Footnote-74858424
Ref: Core and Builtins<140>-Footnote-84858489
Ref: Core and Builtins<140>-Footnote-94858554
Ref: Core and Builtins<140>-Footnote-104858619
Ref: Core and Builtins<140>-Footnote-114858685
Node: Library<143>4858753
Ref: whatsnew/changelog id6134858885
Ref: 1d014858885
Ref: Library<143>-Footnote-14859029
Node: Core and Builtins<141>4859096
Ref: whatsnew/changelog id6144859218
Ref: 1d024859218
Ref: Core and Builtins<141>-Footnote-14859787
Ref: Core and Builtins<141>-Footnote-24859852
Node: Library<144>4859917
Ref: whatsnew/changelog id6154860049
Ref: 1d034860049
Ref: Library<144>-Footnote-14860279
Ref: Library<144>-Footnote-24860346
Node: Core and Builtins<142>4860413
Ref: whatsnew/changelog id6164860535
Ref: 1d044860535
Ref: Core and Builtins<142>-Footnote-14862509
Ref: Core and Builtins<142>-Footnote-24862574
Ref: Core and Builtins<142>-Footnote-34862639
Ref: Core and Builtins<142>-Footnote-44862704
Ref: Core and Builtins<142>-Footnote-54862769
Ref: Core and Builtins<142>-Footnote-64862834
Ref: Core and Builtins<142>-Footnote-74862899
Ref: Core and Builtins<142>-Footnote-84862964
Ref: Core and Builtins<142>-Footnote-94863029
Ref: Core and Builtins<142>-Footnote-104863094
Ref: Core and Builtins<142>-Footnote-114863160
Ref: Core and Builtins<142>-Footnote-124863226
Ref: Core and Builtins<142>-Footnote-134863292
Node: Library<145>4863358
Ref: whatsnew/changelog id6174863490
Ref: 1d054863490
Ref: Library<145>-Footnote-14863641
Node: Core and Builtins<143>4863706
Ref: whatsnew/changelog id6184863828
Ref: 1d064863828
Ref: Core and Builtins<143>-Footnote-14864946
Ref: Core and Builtins<143>-Footnote-24865011
Ref: Core and Builtins<143>-Footnote-34865076
Ref: Core and Builtins<143>-Footnote-44865118
Ref: Core and Builtins<143>-Footnote-54865185
Ref: Core and Builtins<143>-Footnote-64865250
Ref: Core and Builtins<143>-Footnote-74865315
Ref: Core and Builtins<143>-Footnote-84865382
Node: Library<146>4865447
Ref: whatsnew/changelog id6194865579
Ref: 1d074865579
Ref: Library<146>-Footnote-14865793
Ref: Library<146>-Footnote-24865858
Node: Core and Builtins<144>4865900
Ref: whatsnew/changelog id6204866022
Ref: 1d084866022
Ref: Core and Builtins<144>-Footnote-14870957
Ref: Core and Builtins<144>-Footnote-24871022
Ref: Core and Builtins<144>-Footnote-34871087
Ref: Core and Builtins<144>-Footnote-44871152
Ref: Core and Builtins<144>-Footnote-54871217
Ref: Core and Builtins<144>-Footnote-64871282
Ref: Core and Builtins<144>-Footnote-74871347
Ref: Core and Builtins<144>-Footnote-84871412
Ref: Core and Builtins<144>-Footnote-94871477
Ref: Core and Builtins<144>-Footnote-104871542
Ref: Core and Builtins<144>-Footnote-114871608
Ref: Core and Builtins<144>-Footnote-124871674
Ref: Core and Builtins<144>-Footnote-134871740
Ref: Core and Builtins<144>-Footnote-144871808
Ref: Core and Builtins<144>-Footnote-154871874
Ref: Core and Builtins<144>-Footnote-164871940
Ref: Core and Builtins<144>-Footnote-174872006
Ref: Core and Builtins<144>-Footnote-184872072
Ref: Core and Builtins<144>-Footnote-194872138
Ref: Core and Builtins<144>-Footnote-204872204
Ref: Core and Builtins<144>-Footnote-214872270
Ref: Core and Builtins<144>-Footnote-224872336
Ref: Core and Builtins<144>-Footnote-234872402
Ref: Core and Builtins<144>-Footnote-244872468
Ref: Core and Builtins<144>-Footnote-254872534
Ref: Core and Builtins<144>-Footnote-264872600
Node: Library<147>4872665
Ref: whatsnew/changelog id6214872797
Ref: 1d0d4872797
Ref: Library<147>-Footnote-14873014
Ref: Library<147>-Footnote-24873081
Node: Core and Builtins<145>4873148
Ref: whatsnew/changelog id6224873270
Ref: 1d0e4873270
Ref: Core and Builtins<145>-Footnote-14873857
Ref: Core and Builtins<145>-Footnote-24873922
Node: Library<148>4873987
Ref: whatsnew/changelog id6234874119
Ref: 1d0f4874119
Ref: Library<148>-Footnote-14874487
Node: Core and Builtins<146>4874552
Ref: whatsnew/changelog id6244874674
Ref: 1d104874674
Ref: Core and Builtins<146>-Footnote-14875018
Ref: Core and Builtins<146>-Footnote-24875083
Node: Library<149>4875148
Ref: whatsnew/changelog id6254875275
Ref: 1d114875275
Ref: Library<149>-Footnote-14897453
Ref: Library<149>-Footnote-24897518
Ref: Library<149>-Footnote-34897583
Ref: Library<149>-Footnote-44897648
Ref: Library<149>-Footnote-54897713
Ref: Library<149>-Footnote-64897778
Ref: Library<149>-Footnote-74897843
Ref: Library<149>-Footnote-84897908
Ref: Library<149>-Footnote-94897973
Ref: Library<149>-Footnote-104898038
Ref: Library<149>-Footnote-114898104
Ref: Library<149>-Footnote-124898170
Ref: Library<149>-Footnote-134898236
Ref: Library<149>-Footnote-144898302
Ref: Library<149>-Footnote-154898368
Ref: Library<149>-Footnote-164898434
Ref: Library<149>-Footnote-174898487
Ref: Library<149>-Footnote-184898553
Ref: Library<149>-Footnote-194898619
Ref: Library<149>-Footnote-204898685
Ref: Library<149>-Footnote-214898753
Ref: Library<149>-Footnote-224898796
Ref: Library<149>-Footnote-234898864
Ref: Library<149>-Footnote-244898907
Ref: Library<149>-Footnote-254898973
Ref: Library<149>-Footnote-264899039
Ref: Library<149>-Footnote-274899105
Ref: Library<149>-Footnote-284899171
Ref: Library<149>-Footnote-294899237
Ref: Library<149>-Footnote-304899303
Ref: Library<149>-Footnote-314899369
Ref: Library<149>-Footnote-324899435
Ref: Library<149>-Footnote-334899501
Ref: Library<149>-Footnote-344899567
Ref: Library<149>-Footnote-354899633
Ref: Library<149>-Footnote-364899699
Ref: Library<149>-Footnote-374899765
Ref: Library<149>-Footnote-384899831
Ref: Library<149>-Footnote-394899897
Ref: Library<149>-Footnote-404899963
Ref: Library<149>-Footnote-414900029
Ref: Library<149>-Footnote-424900095
Ref: Library<149>-Footnote-434900161
Ref: Library<149>-Footnote-444900227
Ref: Library<149>-Footnote-454900293
Ref: Library<149>-Footnote-464900359
Ref: Library<149>-Footnote-474900425
Ref: Library<149>-Footnote-484900491
Ref: Library<149>-Footnote-494900557
Ref: Library<149>-Footnote-504900623
Ref: Library<149>-Footnote-514900689
Ref: Library<149>-Footnote-524900755
Ref: Library<149>-Footnote-534900821
Ref: Library<149>-Footnote-544900887
Ref: Library<149>-Footnote-554900953
Ref: Library<149>-Footnote-564901019
Ref: Library<149>-Footnote-574901085
Ref: Library<149>-Footnote-584901142
Ref: Library<149>-Footnote-594901208
Ref: Library<149>-Footnote-604901274
Ref: Library<149>-Footnote-614901340
Ref: Library<149>-Footnote-624901406
Ref: Library<149>-Footnote-634901472
Ref: Library<149>-Footnote-644901538
Ref: Library<149>-Footnote-654901604
Ref: Library<149>-Footnote-664901670
Ref: Library<149>-Footnote-674901736
Ref: Library<149>-Footnote-684901802
Ref: Library<149>-Footnote-694901868
Ref: Library<149>-Footnote-704901934
Ref: Library<149>-Footnote-714902000
Ref: Library<149>-Footnote-724902066
Ref: Library<149>-Footnote-734902132
Ref: Library<149>-Footnote-744902198
Ref: Library<149>-Footnote-754902264
Ref: Library<149>-Footnote-764902330
Ref: Library<149>-Footnote-774902396
Ref: Library<149>-Footnote-784902462
Ref: Library<149>-Footnote-794902528
Ref: Library<149>-Footnote-804902594
Ref: Library<149>-Footnote-814902660
Ref: Library<149>-Footnote-824902726
Ref: Library<149>-Footnote-834902792
Ref: Library<149>-Footnote-844902858
Ref: Library<149>-Footnote-854902924
Ref: Library<149>-Footnote-864902990
Ref: Library<149>-Footnote-874903056
Ref: Library<149>-Footnote-884903122
Ref: Library<149>-Footnote-894903188
Ref: Library<149>-Footnote-904903254
Ref: Library<149>-Footnote-914903320
Ref: Library<149>-Footnote-924903386
Ref: Library<149>-Footnote-934903452
Ref: Library<149>-Footnote-944903518
Ref: Library<149>-Footnote-954903584
Ref: Library<149>-Footnote-964903650
Ref: Library<149>-Footnote-974903716
Ref: Library<149>-Footnote-984903782
Ref: Library<149>-Footnote-994903848
Ref: Library<149>-Footnote-1004903914
Ref: Library<149>-Footnote-1014903981
Ref: Library<149>-Footnote-1024904048
Ref: Library<149>-Footnote-1034904115
Ref: Library<149>-Footnote-1044904182
Ref: Library<149>-Footnote-1054904249
Ref: Library<149>-Footnote-1064904316
Ref: Library<149>-Footnote-1074904383
Ref: Library<149>-Footnote-1084904450
Ref: Library<149>-Footnote-1094904517
Ref: Library<149>-Footnote-1104904584
Ref: Library<149>-Footnote-1114904651
Ref: Library<149>-Footnote-1124904718
Ref: Library<149>-Footnote-1134904785
Ref: Library<149>-Footnote-1144904852
Ref: Library<149>-Footnote-1154904919
Ref: Library<149>-Footnote-1164904986
Ref: Library<149>-Footnote-1174905053
Ref: Library<149>-Footnote-1184905120
Ref: Library<149>-Footnote-1194905187
Ref: Library<149>-Footnote-1204905254
Ref: Library<149>-Footnote-1214905320
Ref: Library<149>-Footnote-1224905387
Ref: Library<149>-Footnote-1234905454
Ref: Library<149>-Footnote-1244905521
Ref: Library<149>-Footnote-1254905588
Ref: Library<149>-Footnote-1264905632
Ref: Library<149>-Footnote-1274905699
Ref: Library<149>-Footnote-1284905766
Ref: Library<149>-Footnote-1294905833
Ref: Library<149>-Footnote-1304905900
Ref: Library<149>-Footnote-1314905967
Ref: Library<149>-Footnote-1324906034
Ref: Library<149>-Footnote-1334906101
Ref: Library<149>-Footnote-1344906168
Ref: Library<149>-Footnote-1354906235
Ref: Library<149>-Footnote-1364906302
Ref: Library<149>-Footnote-1374906369
Ref: Library<149>-Footnote-1384906436
Ref: Library<149>-Footnote-1394906503
Ref: Library<149>-Footnote-1404906570
Ref: Library<149>-Footnote-1414906637
Ref: Library<149>-Footnote-1424906704
Ref: Library<149>-Footnote-1434906771
Ref: Library<149>-Footnote-1444906838
Ref: Library<149>-Footnote-1454906905
Ref: Library<149>-Footnote-1464906972
Ref: Library<149>-Footnote-1474907039
Ref: Library<149>-Footnote-1484907106
Ref: Library<149>-Footnote-1494907173
Ref: Library<149>-Footnote-1504907240
Ref: Library<149>-Footnote-1514907307
Ref: Library<149>-Footnote-1524907374
Ref: Library<149>-Footnote-1534907441
Ref: Library<149>-Footnote-1544907508
Node: Documentation<43>4907575
Ref: whatsnew/changelog id6264907689
Ref: 1d184907689
Ref: Documentation<43>-Footnote-14909452
Ref: Documentation<43>-Footnote-24909517
Ref: Documentation<43>-Footnote-34909559
Ref: Documentation<43>-Footnote-44909624
Ref: Documentation<43>-Footnote-54909689
Ref: Documentation<43>-Footnote-64909754
Ref: Documentation<43>-Footnote-74909819
Ref: Documentation<43>-Footnote-84909884
Ref: Documentation<43>-Footnote-94909949
Ref: Documentation<43>-Footnote-104910014
Ref: Documentation<43>-Footnote-114910080
Ref: Documentation<43>-Footnote-124910146
Ref: Documentation<43>-Footnote-134910212
Ref: Documentation<43>-Footnote-144910278
Node: Tests<43>4910344
Ref: whatsnew/changelog id6274910455
Ref: 1d1a4910455
Ref: Tests<43>-Footnote-14912610
Ref: Tests<43>-Footnote-24912675
Ref: Tests<43>-Footnote-34912740
Ref: Tests<43>-Footnote-44912805
Ref: Tests<43>-Footnote-54912870
Ref: Tests<43>-Footnote-64912935
Ref: Tests<43>-Footnote-74913000
Ref: Tests<43>-Footnote-84913065
Ref: Tests<43>-Footnote-94913130
Ref: Tests<43>-Footnote-104913195
Ref: Tests<43>-Footnote-114913261
Ref: Tests<43>-Footnote-124913327
Ref: Tests<43>-Footnote-134913393
Ref: Tests<43>-Footnote-144913459
Ref: Tests<43>-Footnote-154913525
Ref: Tests<43>-Footnote-164913591
Node: Build<50>4913657
Ref: whatsnew/changelog id6284913762
Ref: 1d1d4913762
Ref: Build<50>-Footnote-14914683
Ref: Build<50>-Footnote-24914748
Ref: Build<50>-Footnote-34914813
Ref: Build<50>-Footnote-44914878
Ref: Build<50>-Footnote-54914943
Ref: Build<50>-Footnote-64915008
Node: Windows<43>4915073
Ref: whatsnew/changelog id6294915178
Ref: 1d1e4915178
Ref: Windows<43>-Footnote-14916949
Ref: Windows<43>-Footnote-24917014
Ref: Windows<43>-Footnote-34917079
Ref: Windows<43>-Footnote-44917144
Ref: Windows<43>-Footnote-54917209
Ref: Windows<43>-Footnote-64917274
Ref: Windows<43>-Footnote-74917339
Ref: Windows<43>-Footnote-84917404
Ref: Windows<43>-Footnote-94917469
Ref: Windows<43>-Footnote-104917534
Ref: Windows<43>-Footnote-114917600
Ref: Windows<43>-Footnote-124917666
Ref: Windows<43>-Footnote-134917732
Ref: Windows<43>-Footnote-144917798
Node: macOS<33>4917864
Ref: whatsnew/changelog id6304917968
Ref: 1d1f4917968
Ref: macOS<33>-Footnote-14918859
Ref: macOS<33>-Footnote-24918924
Ref: macOS<33>-Footnote-34918989
Ref: macOS<33>-Footnote-44919054
Ref: macOS<33>-Footnote-54919119
Ref: macOS<33>-Footnote-64919184
Node: IDLE<26>4919249
Ref: whatsnew/changelog id6314919351
Ref: 1d204919351
Ref: IDLE<26>-Footnote-14920516
Ref: IDLE<26>-Footnote-24920581
Ref: IDLE<26>-Footnote-34920646
Ref: IDLE<26>-Footnote-44920711
Ref: IDLE<26>-Footnote-54920776
Ref: IDLE<26>-Footnote-64920841
Ref: IDLE<26>-Footnote-74920906
Ref: IDLE<26>-Footnote-84920971
Ref: IDLE<26>-Footnote-94921036
Ref: IDLE<26>-Footnote-104921101
Ref: IDLE<26>-Footnote-114921167
Node: C API<45>4921233
Ref: whatsnew/changelog id6324921317
Ref: 1d214921317
Ref: C API<45>-Footnote-14926497
Ref: C API<45>-Footnote-24926562
Ref: C API<45>-Footnote-34926627
Ref: C API<45>-Footnote-44926692
Ref: C API<45>-Footnote-54926757
Ref: C API<45>-Footnote-64926822
Ref: C API<45>-Footnote-74926887
Ref: C API<45>-Footnote-84926952
Ref: C API<45>-Footnote-94927017
Ref: C API<45>-Footnote-104927082
Ref: C API<45>-Footnote-114927148
Ref: C API<45>-Footnote-124927214
Ref: C API<45>-Footnote-134927280
Ref: C API<45>-Footnote-144927346
Ref: C API<45>-Footnote-154927412
Ref: C API<45>-Footnote-164927478
Ref: C API<45>-Footnote-174927544
Ref: C API<45>-Footnote-184927610
Ref: C API<45>-Footnote-194927676
Ref: C API<45>-Footnote-204927742
Ref: C API<45>-Footnote-214927785
Ref: C API<45>-Footnote-224927851
Ref: C API<45>-Footnote-234927917
Ref: C API<45>-Footnote-244927983
Ref: C API<45>-Footnote-254928049
Ref: C API<45>-Footnote-264928115
Ref: C API<45>-Footnote-274928181
Ref: C API<45>-Footnote-284928247
Ref: C API<45>-Footnote-294928313
Node: Python 3 9 0 beta 14928379
Ref: whatsnew/changelog python-3-9-0-beta-14928503
Ref: 1d2b4928503
Node: Security<37>4928866
Ref: whatsnew/changelog id6334928965
Ref: 1d2c4928965
Ref: Security<37>-Footnote-14929169
Node: Core and Builtins<147>4929234
Ref: whatsnew/changelog id6344929354
Ref: 1d2d4929354
Ref: Core and Builtins<147>-Footnote-14931897
Ref: Core and Builtins<147>-Footnote-24931962
Ref: Core and Builtins<147>-Footnote-34932027
Ref: Core and Builtins<147>-Footnote-44932092
Ref: Core and Builtins<147>-Footnote-54932157
Ref: Core and Builtins<147>-Footnote-64932222
Ref: Core and Builtins<147>-Footnote-74932264
Ref: Core and Builtins<147>-Footnote-84932329
Ref: Core and Builtins<147>-Footnote-94932394
Ref: Core and Builtins<147>-Footnote-104932461
Ref: Core and Builtins<147>-Footnote-114932504
Ref: Core and Builtins<147>-Footnote-124932570
Ref: Core and Builtins<147>-Footnote-134932638
Ref: Core and Builtins<147>-Footnote-144932681
Ref: Core and Builtins<147>-Footnote-154932747
Ref: Core and Builtins<147>-Footnote-164932813
Ref: Core and Builtins<147>-Footnote-174932879
Ref: Core and Builtins<147>-Footnote-184932945
Ref: Core and Builtins<147>-Footnote-194933013
Ref: Core and Builtins<147>-Footnote-204933056
Ref: Core and Builtins<147>-Footnote-214933122
Ref: Core and Builtins<147>-Footnote-224933188
Ref: Core and Builtins<147>-Footnote-234933254
Ref: Core and Builtins<147>-Footnote-244933320
Node: Library<150>4933386
Ref: whatsnew/changelog id6354933511
Ref: 1d2f4933511
Ref: Library<150>-Footnote-14940901
Ref: Library<150>-Footnote-24940966
Ref: Library<150>-Footnote-34941031
Ref: Library<150>-Footnote-44941096
Ref: Library<150>-Footnote-54941161
Ref: Library<150>-Footnote-64941226
Ref: Library<150>-Footnote-74941291
Ref: Library<150>-Footnote-84941356
Ref: Library<150>-Footnote-94941421
Ref: Library<150>-Footnote-104941486
Ref: Library<150>-Footnote-114941552
Ref: Library<150>-Footnote-124941618
Ref: Library<150>-Footnote-134941684
Ref: Library<150>-Footnote-144941750
Ref: Library<150>-Footnote-154941816
Ref: Library<150>-Footnote-164941859
Ref: Library<150>-Footnote-174941925
Ref: Library<150>-Footnote-184941991
Ref: Library<150>-Footnote-194942057
Ref: Library<150>-Footnote-204942123
Ref: Library<150>-Footnote-214942189
Ref: Library<150>-Footnote-224942255
Ref: Library<150>-Footnote-234942321
Ref: Library<150>-Footnote-244942387
Ref: Library<150>-Footnote-254942453
Ref: Library<150>-Footnote-264942519
Ref: Library<150>-Footnote-274942585
Ref: Library<150>-Footnote-284942651
Ref: Library<150>-Footnote-294942717
Ref: Library<150>-Footnote-304942783
Ref: Library<150>-Footnote-314942849
Ref: Library<150>-Footnote-324942915
Ref: Library<150>-Footnote-334942981
Ref: Library<150>-Footnote-344943047
Ref: Library<150>-Footnote-354943113
Ref: Library<150>-Footnote-364943179
Ref: Library<150>-Footnote-374943245
Ref: Library<150>-Footnote-384943311
Ref: Library<150>-Footnote-394943377
Ref: Library<150>-Footnote-404943443
Ref: Library<150>-Footnote-414943509
Ref: Library<150>-Footnote-424943575
Ref: Library<150>-Footnote-434943641
Ref: Library<150>-Footnote-444943707
Ref: Library<150>-Footnote-454943773
Ref: Library<150>-Footnote-464943839
Ref: Library<150>-Footnote-474943905
Ref: Library<150>-Footnote-484943971
Ref: Library<150>-Footnote-494944037
Ref: Library<150>-Footnote-504944103
Node: Documentation<44>4944169
Ref: whatsnew/changelog id6364944281
Ref: 1d344944281
Ref: Documentation<44>-Footnote-14944950
Ref: Documentation<44>-Footnote-24945015
Ref: Documentation<44>-Footnote-34945080
Ref: Documentation<44>-Footnote-44945145
Ref: Documentation<44>-Footnote-54945210
Node: Tests<44>4945275
Ref: whatsnew/changelog id6374945384
Ref: 1d354945384
Ref: Tests<44>-Footnote-14945739
Ref: Tests<44>-Footnote-24945804
Node: Build<51>4945869
Ref: whatsnew/changelog id6384945972
Ref: 1d364945972
Ref: Build<51>-Footnote-14946312
Ref: Build<51>-Footnote-24946377
Node: Windows<44>4946442
Ref: whatsnew/changelog id6394946545
Ref: 1d374946545
Ref: Windows<44>-Footnote-14947000
Ref: Windows<44>-Footnote-24947065
Ref: Windows<44>-Footnote-34947130
Node: macOS<34>4947195
Ref: whatsnew/changelog id6404947304
Ref: 1d384947304
Ref: macOS<34>-Footnote-14947927
Ref: macOS<34>-Footnote-24947992
Node: Tools/Demos<30>4948057
Ref: whatsnew/changelog id6414948164
Ref: 1d394948164
Ref: Tools/Demos<30>-Footnote-14948649
Ref: Tools/Demos<30>-Footnote-24948714
Ref: Tools/Demos<30>-Footnote-34948779
Node: C API<46>4948844
Ref: whatsnew/changelog id6424948933
Ref: 1d3a4948933
Ref: C API<46>-Footnote-14950959
Ref: C API<46>-Footnote-24951024
Ref: C API<46>-Footnote-34951089
Ref: C API<46>-Footnote-44951154
Ref: C API<46>-Footnote-54951219
Ref: C API<46>-Footnote-64951284
Ref: C API<46>-Footnote-74951349
Ref: C API<46>-Footnote-84951414
Ref: C API<46>-Footnote-94951479
Ref: C API<46>-Footnote-104951544
Ref: C API<46>-Footnote-114951610
Node: Python 3 9 0 alpha 64951653
Ref: whatsnew/changelog python-3-9-0-alpha-64951776
Ref: 1d3b4951776
Node: Security<38>4952159
Ref: whatsnew/changelog id6434952259
Ref: 1d3c4952259
Ref: Security<38>-Footnote-14952907
Ref: Security<38>-Footnote-24952972
Ref: Security<38>-Footnote-34953037
Ref: Security<38>-Footnote-44953102
Node: Core and Builtins<148>4953157
Ref: whatsnew/changelog id6444953278
Ref: 1d3d4953278
Ref: Core and Builtins<148>-Footnote-14957051
Ref: Core and Builtins<148>-Footnote-24957116
Ref: Core and Builtins<148>-Footnote-34957181
Ref: Core and Builtins<148>-Footnote-44957246
Ref: Core and Builtins<148>-Footnote-54957311
Ref: Core and Builtins<148>-Footnote-64957376
Ref: Core and Builtins<148>-Footnote-74957441
Ref: Core and Builtins<148>-Footnote-84957506
Ref: Core and Builtins<148>-Footnote-94957571
Ref: Core and Builtins<148>-Footnote-104957636
Ref: Core and Builtins<148>-Footnote-114957679
Ref: Core and Builtins<148>-Footnote-124957745
Ref: Core and Builtins<148>-Footnote-134957813
Ref: Core and Builtins<148>-Footnote-144957856
Ref: Core and Builtins<148>-Footnote-154957924
Ref: Core and Builtins<148>-Footnote-164957967
Ref: Core and Builtins<148>-Footnote-174958035
Ref: Core and Builtins<148>-Footnote-184958078
Ref: Core and Builtins<148>-Footnote-194958144
Ref: Core and Builtins<148>-Footnote-204958210
Ref: Core and Builtins<148>-Footnote-214958278
Ref: Core and Builtins<148>-Footnote-224958346
Ref: Core and Builtins<148>-Footnote-234958412
Ref: Core and Builtins<148>-Footnote-244958480
Ref: Core and Builtins<148>-Footnote-254958523
Ref: Core and Builtins<148>-Footnote-264958591
Ref: Core and Builtins<148>-Footnote-274958634
Ref: Core and Builtins<148>-Footnote-284958700
Ref: Core and Builtins<148>-Footnote-294958766
Ref: Core and Builtins<148>-Footnote-304958809
Ref: Core and Builtins<148>-Footnote-314958875
Ref: Core and Builtins<148>-Footnote-324958941
Ref: Core and Builtins<148>-Footnote-334959007
Node: Library<151>4959050
Ref: whatsnew/changelog id6454959176
Ref: 1d3e4959176
Ref: Library<151>-Footnote-14969436
Ref: Library<151>-Footnote-24969501
Ref: Library<151>-Footnote-34969566
Ref: Library<151>-Footnote-44969631
Ref: Library<151>-Footnote-54969696
Ref: Library<151>-Footnote-64969761
Ref: Library<151>-Footnote-74969803
Ref: Library<151>-Footnote-84969868
Ref: Library<151>-Footnote-94969933
Ref: Library<151>-Footnote-104969998
Ref: Library<151>-Footnote-114970064
Ref: Library<151>-Footnote-124970130
Ref: Library<151>-Footnote-134970196
Ref: Library<151>-Footnote-144970262
Ref: Library<151>-Footnote-154970328
Ref: Library<151>-Footnote-164970394
Ref: Library<151>-Footnote-174970460
Ref: Library<151>-Footnote-184970526
Ref: Library<151>-Footnote-194970592
Ref: Library<151>-Footnote-204970658
Ref: Library<151>-Footnote-214970724
Ref: Library<151>-Footnote-224970790
Ref: Library<151>-Footnote-234970856
Ref: Library<151>-Footnote-244970922
Ref: Library<151>-Footnote-254970988
Ref: Library<151>-Footnote-264971054
Ref: Library<151>-Footnote-274971120
Ref: Library<151>-Footnote-284971186
Ref: Library<151>-Footnote-294971252
Ref: Library<151>-Footnote-304971318
Ref: Library<151>-Footnote-314971384
Ref: Library<151>-Footnote-324971450
Ref: Library<151>-Footnote-334971516
Ref: Library<151>-Footnote-344971582
Ref: Library<151>-Footnote-354971648
Ref: Library<151>-Footnote-364971714
Ref: Library<151>-Footnote-374971780
Ref: Library<151>-Footnote-384971846
Ref: Library<151>-Footnote-394971912
Ref: Library<151>-Footnote-404971978
Ref: Library<151>-Footnote-414972044
Ref: Library<151>-Footnote-424972110
Ref: Library<151>-Footnote-434972176
Ref: Library<151>-Footnote-444972242
Ref: Library<151>-Footnote-454972308
Ref: Library<151>-Footnote-464972374
Ref: Library<151>-Footnote-474972440
Ref: Library<151>-Footnote-484972506
Ref: Library<151>-Footnote-494972549
Ref: Library<151>-Footnote-504972615
Ref: Library<151>-Footnote-514972658
Ref: Library<151>-Footnote-524972724
Ref: Library<151>-Footnote-534972790
Ref: Library<151>-Footnote-544972856
Ref: Library<151>-Footnote-554972899
Ref: Library<151>-Footnote-564972965
Ref: Library<151>-Footnote-574973031
Ref: Library<151>-Footnote-584973097
Ref: Library<151>-Footnote-594973163
Ref: Library<151>-Footnote-604973229
Ref: Library<151>-Footnote-614973295
Node: Documentation<45>4973361
Ref: whatsnew/changelog id6464973474
Ref: 1d414973474
Ref: Documentation<45>-Footnote-14974049
Ref: Documentation<45>-Footnote-24974114
Ref: Documentation<45>-Footnote-34974179
Ref: Documentation<45>-Footnote-44974244
Node: Tests<45>4974309
Ref: whatsnew/changelog id6474974419
Ref: 1d444974419
Ref: Tests<45>-Footnote-14975500
Ref: Tests<45>-Footnote-24975565
Ref: Tests<45>-Footnote-34975630
Ref: Tests<45>-Footnote-44975695
Ref: Tests<45>-Footnote-54975760
Ref: Tests<45>-Footnote-64975825
Ref: Tests<45>-Footnote-74975890
Ref: Tests<45>-Footnote-84975949
Ref: Tests<45>-Footnote-94976014
Node: Build<52>4976078
Ref: whatsnew/changelog id6484976182
Ref: 1d464976182
Ref: Build<52>-Footnote-14976599
Ref: Build<52>-Footnote-24976664
Ref: Build<52>-Footnote-34976729
Node: Windows<45>4976794
Ref: whatsnew/changelog id6494976898
Ref: 1d474976898
Ref: Windows<45>-Footnote-14977111
Ref: Windows<45>-Footnote-24977176
Node: macOS<35>4977240
Ref: whatsnew/changelog id6504977343
Ref: 1d484977343
Ref: macOS<35>-Footnote-14977799
Ref: macOS<35>-Footnote-24977864
Node: IDLE<27>4977929
Ref: whatsnew/changelog id6514978036
Ref: 1d494978036
Ref: IDLE<27>-Footnote-14978380
Ref: IDLE<27>-Footnote-24978445
Node: Tools/Demos<31>4978510
Ref: whatsnew/changelog id6524978617
Ref: 1d4a4978617
Ref: Tools/Demos<31>-Footnote-14979084
Ref: Tools/Demos<31>-Footnote-24979149
Ref: Tools/Demos<31>-Footnote-34979214
Node: C API<47>4979279
Ref: whatsnew/changelog id6534979369
Ref: 1d4b4979369
Ref: C API<47>-Footnote-14981344
Ref: C API<47>-Footnote-24981409
Ref: C API<47>-Footnote-34981474
Ref: C API<47>-Footnote-44981539
Ref: C API<47>-Footnote-54981604
Ref: C API<47>-Footnote-64981669
Ref: C API<47>-Footnote-74981734
Ref: C API<47>-Footnote-84981799
Ref: C API<47>-Footnote-94981864
Node: Python 3 9 0 alpha 54981929
Ref: whatsnew/changelog python-3-9-0-alpha-54982053
Ref: 1d4c4982053
Node: Security<39>4982436
Ref: whatsnew/changelog id6544982536
Ref: 1d4d4982536
Ref: Security<39>-Footnote-14982820
Ref: Security<39>-Footnote-24982885
Node: Core and Builtins<149>4982941
Ref: whatsnew/changelog id6554983062
Ref: 1d4e4983062
Ref: Core and Builtins<149>-Footnote-14988917
Ref: Core and Builtins<149>-Footnote-24988982
Ref: Core and Builtins<149>-Footnote-34989049
Ref: Core and Builtins<149>-Footnote-44989091
Ref: Core and Builtins<149>-Footnote-54989158
Ref: Core and Builtins<149>-Footnote-64989200
Ref: Core and Builtins<149>-Footnote-74989265
Ref: Core and Builtins<149>-Footnote-84989330
Ref: Core and Builtins<149>-Footnote-94989397
Ref: Core and Builtins<149>-Footnote-104989464
Ref: Core and Builtins<149>-Footnote-114989507
Ref: Core and Builtins<149>-Footnote-124989573
Ref: Core and Builtins<149>-Footnote-134989616
Ref: Core and Builtins<149>-Footnote-144989682
Ref: Core and Builtins<149>-Footnote-154989748
Ref: Core and Builtins<149>-Footnote-164989791
Ref: Core and Builtins<149>-Footnote-174989859
Ref: Core and Builtins<149>-Footnote-184989902
Ref: Core and Builtins<149>-Footnote-194989968
Ref: Core and Builtins<149>-Footnote-204990034
Ref: Core and Builtins<149>-Footnote-214990100
Ref: Core and Builtins<149>-Footnote-224990166
Ref: Core and Builtins<149>-Footnote-234990209
Ref: Core and Builtins<149>-Footnote-244990275
Ref: Core and Builtins<149>-Footnote-254990341
Ref: Core and Builtins<149>-Footnote-264990407
Ref: Core and Builtins<149>-Footnote-274990473
Ref: Core and Builtins<149>-Footnote-284990539
Ref: Core and Builtins<149>-Footnote-294990605
Ref: Core and Builtins<149>-Footnote-304990671
Ref: Core and Builtins<149>-Footnote-314990737
Ref: Core and Builtins<149>-Footnote-324990805
Ref: Core and Builtins<149>-Footnote-334990848
Ref: Core and Builtins<149>-Footnote-344990914
Ref: Core and Builtins<149>-Footnote-354990957
Ref: Core and Builtins<149>-Footnote-364991023
Ref: Core and Builtins<149>-Footnote-374991091
Ref: Core and Builtins<149>-Footnote-384991134
Ref: Core and Builtins<149>-Footnote-394991200
Ref: Core and Builtins<149>-Footnote-404991266
Ref: Core and Builtins<149>-Footnote-414991332
Ref: Core and Builtins<149>-Footnote-424991398
Node: Library<152>4991464
Ref: whatsnew/changelog id6564991590
Ref: 1d4f4991590
Ref: Library<152>-Footnote-15000745
Ref: Library<152>-Footnote-25000810
Ref: Library<152>-Footnote-35000875
Ref: Library<152>-Footnote-45000940
Ref: Library<152>-Footnote-55001005
Ref: Library<152>-Footnote-65001070
Ref: Library<152>-Footnote-75001135
Ref: Library<152>-Footnote-85001200
Ref: Library<152>-Footnote-95001265
Ref: Library<152>-Footnote-105001330
Ref: Library<152>-Footnote-115001396
Ref: Library<152>-Footnote-125001462
Ref: Library<152>-Footnote-135001505
Ref: Library<152>-Footnote-145001571
Ref: Library<152>-Footnote-155001637
Ref: Library<152>-Footnote-165001703
Ref: Library<152>-Footnote-175001746
Ref: Library<152>-Footnote-185001812
Ref: Library<152>-Footnote-195001878
Ref: Library<152>-Footnote-205001944
Ref: Library<152>-Footnote-215002010
Ref: Library<152>-Footnote-225002076
Ref: Library<152>-Footnote-235002142
Ref: Library<152>-Footnote-245002208
Ref: Library<152>-Footnote-255002274
Ref: Library<152>-Footnote-265002340
Ref: Library<152>-Footnote-275002406
Ref: Library<152>-Footnote-285002472
Ref: Library<152>-Footnote-295002538
Ref: Library<152>-Footnote-305002604
Ref: Library<152>-Footnote-315002670
Ref: Library<152>-Footnote-325002736
Ref: Library<152>-Footnote-335002779
Ref: Library<152>-Footnote-345002845
Ref: Library<152>-Footnote-355002911
Ref: Library<152>-Footnote-365002977
Ref: Library<152>-Footnote-375003043
Ref: Library<152>-Footnote-385003109
Ref: Library<152>-Footnote-395003175
Ref: Library<152>-Footnote-405003218
Ref: Library<152>-Footnote-415003284
Ref: Library<152>-Footnote-425003350
Ref: Library<152>-Footnote-435003416
Ref: Library<152>-Footnote-445003482
Ref: Library<152>-Footnote-455003548
Ref: Library<152>-Footnote-465003614
Ref: Library<152>-Footnote-475003680
Ref: Library<152>-Footnote-485003746
Ref: Library<152>-Footnote-495003812
Ref: Library<152>-Footnote-505003878
Ref: Library<152>-Footnote-515003944
Ref: Library<152>-Footnote-525004010
Ref: Library<152>-Footnote-535004076
Ref: Library<152>-Footnote-545004142
Node: Documentation<46>5004208
Ref: whatsnew/changelog id6575004321
Ref: 1d555004321
Ref: Documentation<46>-Footnote-15004964
Ref: Documentation<46>-Footnote-25005029
Ref: Documentation<46>-Footnote-35005071
Ref: Documentation<46>-Footnote-45005136
Ref: Documentation<46>-Footnote-55005201
Ref: Documentation<46>-Footnote-65005266
Ref: Documentation<46>-Footnote-75005331
Node: Tests<46>5005396
Ref: whatsnew/changelog id6585005506
Ref: 1d565005506
Ref: Tests<46>-Footnote-15006190
Ref: Tests<46>-Footnote-25006255
Ref: Tests<46>-Footnote-35006320
Ref: Tests<46>-Footnote-45006385
Node: Build<53>5006450
Ref: whatsnew/changelog id6595006554
Ref: 1d575006554
Ref: Build<53>-Footnote-15007429
Ref: Build<53>-Footnote-25007494
Ref: Build<53>-Footnote-35007559
Node: Windows<46>5007626
Ref: whatsnew/changelog id6605007730
Ref: 1d585007730
Ref: Windows<46>-Footnote-15008612
Ref: Windows<46>-Footnote-25008677
Ref: Windows<46>-Footnote-35008742
Ref: Windows<46>-Footnote-45008807
Ref: Windows<46>-Footnote-55008872
Ref: Windows<46>-Footnote-65008937
Node: macOS<36>5009002
Ref: whatsnew/changelog id6615009105
Ref: 1d595009105
Ref: macOS<36>-Footnote-15009235
Node: IDLE<28>5009300
Ref: whatsnew/changelog id6625009407
Ref: 1d5a5009407
Ref: IDLE<28>-Footnote-15009967
Ref: IDLE<28>-Footnote-25010032
Ref: IDLE<28>-Footnote-35010097
Ref: IDLE<28>-Footnote-45010162
Node: Tools/Demos<32>5010227
Ref: whatsnew/changelog id6635010334
Ref: 1d5b5010334
Ref: Tools/Demos<32>-Footnote-15010867
Ref: Tools/Demos<32>-Footnote-25010932
Node: C API<48>5010997
Ref: whatsnew/changelog id6645011087
Ref: 1d5c5011087
Ref: C API<48>-Footnote-15014635
Ref: C API<48>-Footnote-25014700
Ref: C API<48>-Footnote-35014765
Ref: C API<48>-Footnote-45014830
Ref: C API<48>-Footnote-55014895
Ref: C API<48>-Footnote-65014960
Ref: C API<48>-Footnote-75015025
Ref: C API<48>-Footnote-85015090
Ref: C API<48>-Footnote-95015155
Ref: C API<48>-Footnote-105015220
Ref: C API<48>-Footnote-115015286
Ref: C API<48>-Footnote-125015352
Ref: C API<48>-Footnote-135015418
Ref: C API<48>-Footnote-145015484
Ref: C API<48>-Footnote-155015550
Ref: C API<48>-Footnote-165015616
Ref: C API<48>-Footnote-175015682
Node: Python 3 9 0 alpha 45015748
Ref: whatsnew/changelog python-3-9-0-alpha-45015872
Ref: 1d615015872
Node: Security<40>5016203
Ref: whatsnew/changelog id6655016303
Ref: 1d625016303
Ref: Security<40>-Footnote-15016714
Ref: Security<40>-Footnote-25016779
Ref: Security<40>-Footnote-35016844
Node: Core and Builtins<150>5016909
Ref: whatsnew/changelog id6665017030
Ref: 1d635017030
Ref: Core and Builtins<150>-Footnote-15020439
Ref: Core and Builtins<150>-Footnote-25020504
Ref: Core and Builtins<150>-Footnote-35020569
Ref: Core and Builtins<150>-Footnote-45020634
Ref: Core and Builtins<150>-Footnote-55020699
Ref: Core and Builtins<150>-Footnote-65020764
Ref: Core and Builtins<150>-Footnote-75020829
Ref: Core and Builtins<150>-Footnote-85020894
Ref: Core and Builtins<150>-Footnote-95020961
Ref: Core and Builtins<150>-Footnote-105021003
Ref: Core and Builtins<150>-Footnote-115021071
Ref: Core and Builtins<150>-Footnote-125021114
Ref: Core and Builtins<150>-Footnote-135021180
Ref: Core and Builtins<150>-Footnote-145021246
Ref: Core and Builtins<150>-Footnote-155021312
Ref: Core and Builtins<150>-Footnote-165021378
Ref: Core and Builtins<150>-Footnote-175021444
Ref: Core and Builtins<150>-Footnote-185021512
Ref: Core and Builtins<150>-Footnote-195021555
Ref: Core and Builtins<150>-Footnote-205021623
Ref: Core and Builtins<150>-Footnote-215021666
Ref: Core and Builtins<150>-Footnote-225021734
Ref: Core and Builtins<150>-Footnote-235021777
Ref: Core and Builtins<150>-Footnote-245021843
Ref: Core and Builtins<150>-Footnote-255021909
Ref: Core and Builtins<150>-Footnote-265021975
Ref: Core and Builtins<150>-Footnote-275022041
Ref: Core and Builtins<150>-Footnote-285022107
Ref: Core and Builtins<150>-Footnote-295022173
Node: Library<153>5022239
Ref: whatsnew/changelog id6675022365
Ref: 1d665022365
Ref: Library<153>-Footnote-15028557
Ref: Library<153>-Footnote-25028622
Ref: Library<153>-Footnote-35028687
Ref: Library<153>-Footnote-45028752
Ref: Library<153>-Footnote-55028817
Ref: Library<153>-Footnote-65028882
Ref: Library<153>-Footnote-75028947
Ref: Library<153>-Footnote-85029012
Ref: Library<153>-Footnote-95029077
Ref: Library<153>-Footnote-105029142
Ref: Library<153>-Footnote-115029208
Ref: Library<153>-Footnote-125029274
Ref: Library<153>-Footnote-135029340
Ref: Library<153>-Footnote-145029406
Ref: Library<153>-Footnote-155029472
Ref: Library<153>-Footnote-165029538
Ref: Library<153>-Footnote-175029620
Ref: Library<153>-Footnote-185029686
Ref: Library<153>-Footnote-195029752
Ref: Library<153>-Footnote-205029818
Ref: Library<153>-Footnote-215029884
Ref: Library<153>-Footnote-225029950
Ref: Library<153>-Footnote-235030016
Ref: Library<153>-Footnote-245030082
Ref: Library<153>-Footnote-255030148
Ref: Library<153>-Footnote-265030214
Ref: Library<153>-Footnote-275030280
Ref: Library<153>-Footnote-285030323
Ref: Library<153>-Footnote-295030389
Ref: Library<153>-Footnote-305030455
Ref: Library<153>-Footnote-315030521
Ref: Library<153>-Footnote-325030587
Ref: Library<153>-Footnote-335030653
Ref: Library<153>-Footnote-345030719
Ref: Library<153>-Footnote-355030785
Ref: Library<153>-Footnote-365030851
Ref: Library<153>-Footnote-375030917
Ref: Library<153>-Footnote-385030983
Ref: Library<153>-Footnote-395031049
Node: Documentation<47>5031115
Ref: whatsnew/changelog id6685031228
Ref: 1d685031228
Ref: Documentation<47>-Footnote-15032269
Ref: Documentation<47>-Footnote-25032334
Ref: Documentation<47>-Footnote-35032399
Ref: Documentation<47>-Footnote-45032464
Ref: Documentation<47>-Footnote-55032529
Ref: Documentation<47>-Footnote-65032594
Ref: Documentation<47>-Footnote-75032659
Node: Tests<47>5032723
Ref: whatsnew/changelog id6695032833
Ref: 1d695032833
Ref: Tests<47>-Footnote-15033167
Ref: Tests<47>-Footnote-25033232
Node: Build<54>5033297
Ref: whatsnew/changelog id6705033401
Ref: 1d6a5033401
Ref: Build<54>-Footnote-15033531
Node: Windows<47>5033596
Ref: whatsnew/changelog id6715033699
Ref: 1d6b5033699
Ref: Windows<47>-Footnote-15034507
Ref: Windows<47>-Footnote-25034572
Ref: Windows<47>-Footnote-35034637
Ref: Windows<47>-Footnote-45034702
Ref: Windows<47>-Footnote-55034767
Ref: Windows<47>-Footnote-65034832
Node: IDLE<29>5034897
Ref: whatsnew/changelog id6725035000
Ref: 1d6c5035000
Ref: IDLE<29>-Footnote-15035547
Ref: IDLE<29>-Footnote-25035612
Ref: IDLE<29>-Footnote-35035677
Ref: IDLE<29>-Footnote-45035742
Ref: IDLE<29>-Footnote-55035807
Node: C API<49>5035872
Ref: whatsnew/changelog id6735035955
Ref: 1d6d5035955
Ref: C API<49>-Footnote-15038614
Ref: C API<49>-Footnote-25038679
Ref: C API<49>-Footnote-35038744
Ref: C API<49>-Footnote-45038809
Ref: C API<49>-Footnote-55038874
Ref: C API<49>-Footnote-65038939
Ref: C API<49>-Footnote-75039004
Ref: C API<49>-Footnote-85039069
Ref: C API<49>-Footnote-95039134
Ref: C API<49>-Footnote-105039199
Ref: C API<49>-Footnote-115039265
Ref: C API<49>-Footnote-125039331
Node: Python 3 9 0 alpha 35039397
Ref: whatsnew/changelog python-3-9-0-alpha-35039521
Ref: 1d725039521
Node: Core and Builtins<151>5039782
Ref: whatsnew/changelog id6745039882
Ref: 1d735039882
Ref: Core and Builtins<151>-Footnote-15043988
Ref: Core and Builtins<151>-Footnote-25044053
Ref: Core and Builtins<151>-Footnote-35044118
Ref: Core and Builtins<151>-Footnote-45044183
Ref: Core and Builtins<151>-Footnote-55044248
Ref: Core and Builtins<151>-Footnote-65044313
Ref: Core and Builtins<151>-Footnote-75044378
Ref: Core and Builtins<151>-Footnote-85044443
Ref: Core and Builtins<151>-Footnote-95044508
Ref: Core and Builtins<151>-Footnote-105044573
Ref: Core and Builtins<151>-Footnote-115044639
Ref: Core and Builtins<151>-Footnote-125044707
Ref: Core and Builtins<151>-Footnote-135044750
Ref: Core and Builtins<151>-Footnote-145044816
Ref: Core and Builtins<151>-Footnote-155044882
Ref: Core and Builtins<151>-Footnote-165044948
Ref: Core and Builtins<151>-Footnote-175045014
Ref: Core and Builtins<151>-Footnote-185045080
Ref: Core and Builtins<151>-Footnote-195045146
Ref: Core and Builtins<151>-Footnote-205045212
Ref: Core and Builtins<151>-Footnote-215045278
Ref: Core and Builtins<151>-Footnote-225045344
Ref: Core and Builtins<151>-Footnote-235045410
Ref: Core and Builtins<151>-Footnote-245045476
Node: Library<154>5045542
Ref: whatsnew/changelog id6755045668
Ref: 1d775045668
Ref: Library<154>-Footnote-15055288
Ref: Library<154>-Footnote-25055353
Ref: Library<154>-Footnote-35055418
Ref: Library<154>-Footnote-45055483
Ref: Library<154>-Footnote-55055548
Ref: Library<154>-Footnote-65055613
Ref: Library<154>-Footnote-75055678
Ref: Library<154>-Footnote-85055743
Ref: Library<154>-Footnote-95055808
Ref: Library<154>-Footnote-105055873
Ref: Library<154>-Footnote-115055939
Ref: Library<154>-Footnote-125056005
Ref: Library<154>-Footnote-135056071
Ref: Library<154>-Footnote-145056137
Ref: Library<154>-Footnote-155056203
Ref: Library<154>-Footnote-165056269
Ref: Library<154>-Footnote-175056335
Ref: Library<154>-Footnote-185056401
Ref: Library<154>-Footnote-195056467
Ref: Library<154>-Footnote-205056533
Ref: Library<154>-Footnote-215056599
Ref: Library<154>-Footnote-225056665
Ref: Library<154>-Footnote-235056731
Ref: Library<154>-Footnote-245056797
Ref: Library<154>-Footnote-255056863
Ref: Library<154>-Footnote-265056929
Ref: Library<154>-Footnote-275056995
Ref: Library<154>-Footnote-285057061
Ref: Library<154>-Footnote-295057127
Ref: Library<154>-Footnote-305057193
Ref: Library<154>-Footnote-315057259
Ref: Library<154>-Footnote-325057325
Ref: Library<154>-Footnote-335057391
Ref: Library<154>-Footnote-345057457
Ref: Library<154>-Footnote-355057523
Ref: Library<154>-Footnote-365057589
Ref: Library<154>-Footnote-375057655
Ref: Library<154>-Footnote-385057721
Ref: Library<154>-Footnote-395057787
Ref: Library<154>-Footnote-405057853
Ref: Library<154>-Footnote-415057919
Ref: Library<154>-Footnote-425057985
Ref: Library<154>-Footnote-435058051
Ref: Library<154>-Footnote-445058117
Ref: Library<154>-Footnote-455058183
Ref: Library<154>-Footnote-465058249
Ref: Library<154>-Footnote-475058315
Ref: Library<154>-Footnote-485058381
Ref: Library<154>-Footnote-495058447
Ref: Library<154>-Footnote-505058513
Ref: Library<154>-Footnote-515058579
Ref: Library<154>-Footnote-525058645
Ref: Library<154>-Footnote-535058711
Node: Documentation<48>5058777
Ref: whatsnew/changelog id6765058890
Ref: 1d795058890
Ref: Documentation<48>-Footnote-15059503
Ref: Documentation<48>-Footnote-25059568
Ref: Documentation<48>-Footnote-35059633
Node: Build<55>5059697
Ref: whatsnew/changelog id6775059806
Ref: 1d7b5059806
Ref: Build<55>-Footnote-15060332
Ref: Build<55>-Footnote-25060397
Ref: Build<55>-Footnote-35060462
Node: IDLE<30>5060527
Ref: whatsnew/changelog id6785060628
Ref: 1d7c5060628
Ref: IDLE<30>-Footnote-15061049
Ref: IDLE<30>-Footnote-25061114
Ref: IDLE<30>-Footnote-35061179
Node: C API<50>5061244
Ref: whatsnew/changelog id6795061327
Ref: 1d7d5061327
Ref: C API<50>-Footnote-15062092
Ref: C API<50>-Footnote-25062157
Node: Python 3 9 0 alpha 25062222
Ref: whatsnew/changelog python-3-9-0-alpha-25062346
Ref: 1d7e5062346
Node: Security<41>5062697
Ref: whatsnew/changelog id6805062797
Ref: 1d7f5062797
Ref: Security<41>-Footnote-15063670
Ref: Security<41>-Footnote-25063735
Ref: Security<41>-Footnote-35063800
Ref: Security<41>-Footnote-45063865
Node: Core and Builtins<152>5063930
Ref: whatsnew/changelog id6815064051
Ref: 1d805064051
Ref: Core and Builtins<152>-Footnote-15067752
Ref: Core and Builtins<152>-Footnote-25067817
Ref: Core and Builtins<152>-Footnote-35067882
Ref: Core and Builtins<152>-Footnote-45067947
Ref: Core and Builtins<152>-Footnote-55068012
Ref: Core and Builtins<152>-Footnote-65068077
Ref: Core and Builtins<152>-Footnote-75068142
Ref: Core and Builtins<152>-Footnote-85068207
Ref: Core and Builtins<152>-Footnote-95068272
Ref: Core and Builtins<152>-Footnote-105068337
Ref: Core and Builtins<152>-Footnote-115068403
Ref: Core and Builtins<152>-Footnote-125068469
Ref: Core and Builtins<152>-Footnote-135068535
Ref: Core and Builtins<152>-Footnote-145068601
Ref: Core and Builtins<152>-Footnote-155068667
Ref: Core and Builtins<152>-Footnote-165068733
Ref: Core and Builtins<152>-Footnote-175068799
Ref: Core and Builtins<152>-Footnote-185068865
Ref: Core and Builtins<152>-Footnote-195068931
Ref: Core and Builtins<152>-Footnote-205068997
Node: Library<155>5069063
Ref: whatsnew/changelog id6825069189
Ref: 1d815069189
Ref: Library<155>-Footnote-15076974
Ref: Library<155>-Footnote-25077039
Ref: Library<155>-Footnote-35077104
Ref: Library<155>-Footnote-45077169
Ref: Library<155>-Footnote-55077234
Ref: Library<155>-Footnote-65077299
Ref: Library<155>-Footnote-75077364
Ref: Library<155>-Footnote-85077429
Ref: Library<155>-Footnote-95077494
Ref: Library<155>-Footnote-105077559
Ref: Library<155>-Footnote-115077625
Ref: Library<155>-Footnote-125077691
Ref: Library<155>-Footnote-135077757
Ref: Library<155>-Footnote-145077823
Ref: Library<155>-Footnote-155077889
Ref: Library<155>-Footnote-165077955
Ref: Library<155>-Footnote-175078021
Ref: Library<155>-Footnote-185078087
Ref: Library<155>-Footnote-195078153
Ref: Library<155>-Footnote-205078219
Ref: Library<155>-Footnote-215078285
Ref: Library<155>-Footnote-225078351
Ref: Library<155>-Footnote-235078417
Ref: Library<155>-Footnote-245078483
Ref: Library<155>-Footnote-255078549
Ref: Library<155>-Footnote-265078615
Ref: Library<155>-Footnote-275078681
Ref: Library<155>-Footnote-285078747
Ref: Library<155>-Footnote-295078813
Ref: Library<155>-Footnote-305078879
Ref: Library<155>-Footnote-315078945
Ref: Library<155>-Footnote-325079011
Ref: Library<155>-Footnote-335079077
Ref: Library<155>-Footnote-345079143
Ref: Library<155>-Footnote-355079209
Ref: Library<155>-Footnote-365079275
Ref: Library<155>-Footnote-375079341
Ref: Library<155>-Footnote-385079407
Ref: Library<155>-Footnote-395079473
Ref: Library<155>-Footnote-405079539
Node: Documentation<49>5079605
Ref: whatsnew/changelog id6835079718
Ref: 1d825079718
Ref: Documentation<49>-Footnote-15080305
Ref: Documentation<49>-Footnote-25080370
Ref: Documentation<49>-Footnote-35080435
Node: Tests<48>5080500
Ref: whatsnew/changelog id6845080610
Ref: 1d835080610
Ref: Tests<48>-Footnote-15083186
Ref: Tests<48>-Footnote-25083251
Ref: Tests<48>-Footnote-35083316
Ref: Tests<48>-Footnote-45083381
Ref: Tests<48>-Footnote-55083446
Ref: Tests<48>-Footnote-65083511
Ref: Tests<48>-Footnote-75083576
Ref: Tests<48>-Footnote-85083641
Ref: Tests<48>-Footnote-95083706
Ref: Tests<48>-Footnote-105083771
Ref: Tests<48>-Footnote-115083837
Ref: Tests<48>-Footnote-125083903
Ref: Tests<48>-Footnote-135083969
Node: Build<56>5084035
Ref: whatsnew/changelog id6855084139
Ref: 1d875084139
Ref: Build<56>-Footnote-15084539
Ref: Build<56>-Footnote-25084604
Node: Windows<48>5084669
Ref: whatsnew/changelog id6865084773
Ref: 1d885084773
Ref: Windows<48>-Footnote-15085014
Ref: Windows<48>-Footnote-25085079
Node: macOS<37>5085144
Ref: whatsnew/changelog id6875085247
Ref: 1d895085247
Ref: macOS<37>-Footnote-15085555
Node: IDLE<31>5085620
Ref: whatsnew/changelog id6885085721
Ref: 1d8a5085721
Ref: IDLE<31>-Footnote-15086316
Ref: IDLE<31>-Footnote-25086381
Ref: IDLE<31>-Footnote-35086446
Ref: IDLE<31>-Footnote-45086511
Node: C API<51>5086576
Ref: whatsnew/changelog id6895086659
Ref: 1d8b5086659
Ref: C API<51>-Footnote-15087193
Ref: C API<51>-Footnote-25087258
Ref: C API<51>-Footnote-35087323
Node: Python 3 9 0 alpha 15087388
Ref: whatsnew/changelog python-3-9-0-alpha-15087511
Ref: 1d8c5087511
Node: Security<42>5087894
Ref: whatsnew/changelog id6905087994
Ref: 1d8d5087994
Ref: Security<42>-Footnote-15090317
Ref: Security<42>-Footnote-25090382
Ref: Security<42>-Footnote-35090447
Ref: Security<42>-Footnote-45090512
Ref: Security<42>-Footnote-55090577
Ref: Security<42>-Footnote-65090642
Ref: Security<42>-Footnote-75090707
Ref: Security<42>-Footnote-85090763
Ref: Security<42>-Footnote-95090828
Ref: Security<42>-Footnote-105090893
Ref: Security<42>-Footnote-115090959
Ref: Security<42>-Footnote-125091025
Ref: Security<42>-Footnote-135091091
Ref: Security<42>-Footnote-145091157
Ref: Security<42>-Footnote-155091223
Node: Core and Builtins<153>5091289
Ref: whatsnew/changelog id6915091410
Ref: 1d905091410
Ref: Core and Builtins<153>-Footnote-15106948
Ref: Core and Builtins<153>-Footnote-25107013
Ref: Core and Builtins<153>-Footnote-35107078
Ref: Core and Builtins<153>-Footnote-45107143
Ref: Core and Builtins<153>-Footnote-55107208
Ref: Core and Builtins<153>-Footnote-65107273
Ref: Core and Builtins<153>-Footnote-75107338
Ref: Core and Builtins<153>-Footnote-85107403
Ref: Core and Builtins<153>-Footnote-95107468
Ref: Core and Builtins<153>-Footnote-105107533
Ref: Core and Builtins<153>-Footnote-115107599
Ref: Core and Builtins<153>-Footnote-125107665
Ref: Core and Builtins<153>-Footnote-135107731
Ref: Core and Builtins<153>-Footnote-145107797
Ref: Core and Builtins<153>-Footnote-155107863
Ref: Core and Builtins<153>-Footnote-165107929
Ref: Core and Builtins<153>-Footnote-175107995
Ref: Core and Builtins<153>-Footnote-185108061
Ref: Core and Builtins<153>-Footnote-195108127
Ref: Core and Builtins<153>-Footnote-205108193
Ref: Core and Builtins<153>-Footnote-215108236
Ref: Core and Builtins<153>-Footnote-225108302
Ref: Core and Builtins<153>-Footnote-235108368
Ref: Core and Builtins<153>-Footnote-245108434
Ref: Core and Builtins<153>-Footnote-255108500
Ref: Core and Builtins<153>-Footnote-265108566
Ref: Core and Builtins<153>-Footnote-275108632
Ref: Core and Builtins<153>-Footnote-285108698
Ref: Core and Builtins<153>-Footnote-295108764
Ref: Core and Builtins<153>-Footnote-305108830
Ref: Core and Builtins<153>-Footnote-315108896
Ref: Core and Builtins<153>-Footnote-325108962
Ref: Core and Builtins<153>-Footnote-335109028
Ref: Core and Builtins<153>-Footnote-345109094
Ref: Core and Builtins<153>-Footnote-355109160
Ref: Core and Builtins<153>-Footnote-365109226
Ref: Core and Builtins<153>-Footnote-375109292
Ref: Core and Builtins<153>-Footnote-385109358
Ref: Core and Builtins<153>-Footnote-395109424
Ref: Core and Builtins<153>-Footnote-405109490
Ref: Core and Builtins<153>-Footnote-415109555
Ref: Core and Builtins<153>-Footnote-425109621
Ref: Core and Builtins<153>-Footnote-435109687
Ref: Core and Builtins<153>-Footnote-445109753
Ref: Core and Builtins<153>-Footnote-455109819
Ref: Core and Builtins<153>-Footnote-465109885
Ref: Core and Builtins<153>-Footnote-475109951
Ref: Core and Builtins<153>-Footnote-485110017
Ref: Core and Builtins<153>-Footnote-495110083
Ref: Core and Builtins<153>-Footnote-505110149
Ref: Core and Builtins<153>-Footnote-515110215
Ref: Core and Builtins<153>-Footnote-525110281
Ref: Core and Builtins<153>-Footnote-535110347
Ref: Core and Builtins<153>-Footnote-545110390
Ref: Core and Builtins<153>-Footnote-555110456
Ref: Core and Builtins<153>-Footnote-565110522
Ref: Core and Builtins<153>-Footnote-575110588
Ref: Core and Builtins<153>-Footnote-585110654
Ref: Core and Builtins<153>-Footnote-595110720
Ref: Core and Builtins<153>-Footnote-605110786
Ref: Core and Builtins<153>-Footnote-615110852
Ref: Core and Builtins<153>-Footnote-625110918
Ref: Core and Builtins<153>-Footnote-635110984
Ref: Core and Builtins<153>-Footnote-645111050
Ref: Core and Builtins<153>-Footnote-655111116
Ref: Core and Builtins<153>-Footnote-665111182
Ref: Core and Builtins<153>-Footnote-675111248
Ref: Core and Builtins<153>-Footnote-685111314
Ref: Core and Builtins<153>-Footnote-695111380
Ref: Core and Builtins<153>-Footnote-705111446
Ref: Core and Builtins<153>-Footnote-715111512
Ref: Core and Builtins<153>-Footnote-725111578
Ref: Core and Builtins<153>-Footnote-735111644
Ref: Core and Builtins<153>-Footnote-745111710
Ref: Core and Builtins<153>-Footnote-755111776
Ref: Core and Builtins<153>-Footnote-765111842
Ref: Core and Builtins<153>-Footnote-775111908
Ref: Core and Builtins<153>-Footnote-785111974
Ref: Core and Builtins<153>-Footnote-795112040
Ref: Core and Builtins<153>-Footnote-805112106
Ref: Core and Builtins<153>-Footnote-815112172
Ref: Core and Builtins<153>-Footnote-825112238
Ref: Core and Builtins<153>-Footnote-835112304
Ref: Core and Builtins<153>-Footnote-845112370
Ref: Core and Builtins<153>-Footnote-855112436
Ref: Core and Builtins<153>-Footnote-865112502
Ref: Core and Builtins<153>-Footnote-875112568
Ref: Core and Builtins<153>-Footnote-885112634
Ref: Core and Builtins<153>-Footnote-895112700
Ref: Core and Builtins<153>-Footnote-905112766
Ref: Core and Builtins<153>-Footnote-915112832
Ref: Core and Builtins<153>-Footnote-925112898
Ref: Core and Builtins<153>-Footnote-935112964
Ref: Core and Builtins<153>-Footnote-945113030
Node: Library<156>5113096
Ref: whatsnew/changelog id6925113222
Ref: 1d925113222
Ref: Library<156>-Footnote-15152683
Ref: Library<156>-Footnote-25152748
Ref: Library<156>-Footnote-35152813
Ref: Library<156>-Footnote-45152878
Ref: Library<156>-Footnote-55152943
Ref: Library<156>-Footnote-65153008
Ref: Library<156>-Footnote-75153073
Ref: Library<156>-Footnote-85153138
Ref: Library<156>-Footnote-95153203
Ref: Library<156>-Footnote-105153268
Ref: Library<156>-Footnote-115153334
Ref: Library<156>-Footnote-125153400
Ref: Library<156>-Footnote-135153466
Ref: Library<156>-Footnote-145153532
Ref: Library<156>-Footnote-155153598
Ref: Library<156>-Footnote-165153664
Ref: Library<156>-Footnote-175153730
Ref: Library<156>-Footnote-185153796
Ref: Library<156>-Footnote-195153862
Ref: Library<156>-Footnote-205153928
Ref: Library<156>-Footnote-215153994
Ref: Library<156>-Footnote-225154060
Ref: Library<156>-Footnote-235154126
Ref: Library<156>-Footnote-245154192
Ref: Library<156>-Footnote-255154258
Ref: Library<156>-Footnote-265154324
Ref: Library<156>-Footnote-275154390
Ref: Library<156>-Footnote-285154456
Ref: Library<156>-Footnote-295154522
Ref: Library<156>-Footnote-305154588
Ref: Library<156>-Footnote-315154654
Ref: Library<156>-Footnote-325154720
Ref: Library<156>-Footnote-335154786
Ref: Library<156>-Footnote-345154852
Ref: Library<156>-Footnote-355154918
Ref: Library<156>-Footnote-365154984
Ref: Library<156>-Footnote-375155050
Ref: Library<156>-Footnote-385155116
Ref: Library<156>-Footnote-395155182
Ref: Library<156>-Footnote-405155248
Ref: Library<156>-Footnote-415155314
Ref: Library<156>-Footnote-425155380
Ref: Library<156>-Footnote-435155446
Ref: Library<156>-Footnote-445155512
Ref: Library<156>-Footnote-455155578
Ref: Library<156>-Footnote-465155644
Ref: Library<156>-Footnote-475155710
Ref: Library<156>-Footnote-485155776
Ref: Library<156>-Footnote-495155842
Ref: Library<156>-Footnote-505155908
Ref: Library<156>-Footnote-515155974
Ref: Library<156>-Footnote-525156040
Ref: Library<156>-Footnote-535156106
Ref: Library<156>-Footnote-545156172
Ref: Library<156>-Footnote-555156238
Ref: Library<156>-Footnote-565156304
Ref: Library<156>-Footnote-575156370
Ref: Library<156>-Footnote-585156436
Ref: Library<156>-Footnote-595156502
Ref: Library<156>-Footnote-605156568
Ref: Library<156>-Footnote-615156634
Ref: Library<156>-Footnote-625156700
Ref: Library<156>-Footnote-635156766
Ref: Library<156>-Footnote-645156831
Ref: Library<156>-Footnote-655156897
Ref: Library<156>-Footnote-665156963
Ref: Library<156>-Footnote-675157029
Ref: Library<156>-Footnote-685157095
Ref: Library<156>-Footnote-695157161
Ref: Library<156>-Footnote-705157227
Ref: Library<156>-Footnote-715157293
Ref: Library<156>-Footnote-725157359
Ref: Library<156>-Footnote-735157425
Ref: Library<156>-Footnote-745157491
Ref: Library<156>-Footnote-755157557
Ref: Library<156>-Footnote-765157623
Ref: Library<156>-Footnote-775157731
Ref: Library<156>-Footnote-785157797
Ref: Library<156>-Footnote-795157863
Ref: Library<156>-Footnote-805157929
Ref: Library<156>-Footnote-815157995
Ref: Library<156>-Footnote-825158061
Ref: Library<156>-Footnote-835158127
Ref: Library<156>-Footnote-845158193
Ref: Library<156>-Footnote-855158259
Ref: Library<156>-Footnote-865158325
Ref: Library<156>-Footnote-875158391
Ref: Library<156>-Footnote-885158457
Ref: Library<156>-Footnote-895158523
Ref: Library<156>-Footnote-905158589
Ref: Library<156>-Footnote-915158655
Ref: Library<156>-Footnote-925158721
Ref: Library<156>-Footnote-935158787
Ref: Library<156>-Footnote-945158853
Ref: Library<156>-Footnote-955158919
Ref: Library<156>-Footnote-965158985
Ref: Library<156>-Footnote-975159051
Ref: Library<156>-Footnote-985159117
Ref: Library<156>-Footnote-995159183
Ref: Library<156>-Footnote-1005159249
Ref: Library<156>-Footnote-1015159316
Ref: Library<156>-Footnote-1025159383
Ref: Library<156>-Footnote-1035159450
Ref: Library<156>-Footnote-1045159517
Ref: Library<156>-Footnote-1055159584
Ref: Library<156>-Footnote-1065159651
Ref: Library<156>-Footnote-1075159718
Ref: Library<156>-Footnote-1085159784
Ref: Library<156>-Footnote-1095159851
Ref: Library<156>-Footnote-1105159918
Ref: Library<156>-Footnote-1115159985
Ref: Library<156>-Footnote-1125160052
Ref: Library<156>-Footnote-1135160119
Ref: Library<156>-Footnote-1145160186
Ref: Library<156>-Footnote-1155160253
Ref: Library<156>-Footnote-1165160320
Ref: Library<156>-Footnote-1175160387
Ref: Library<156>-Footnote-1185160454
Ref: Library<156>-Footnote-1195160521
Ref: Library<156>-Footnote-1205160588
Ref: Library<156>-Footnote-1215160655
Ref: Library<156>-Footnote-1225160722
Ref: Library<156>-Footnote-1235160789
Ref: Library<156>-Footnote-1245160856
Ref: Library<156>-Footnote-1255160923
Ref: Library<156>-Footnote-1265160990
Ref: Library<156>-Footnote-1275161057
Ref: Library<156>-Footnote-1285161124
Ref: Library<156>-Footnote-1295161191
Ref: Library<156>-Footnote-1305161258
Ref: Library<156>-Footnote-1315161325
Ref: Library<156>-Footnote-1325161392
Ref: Library<156>-Footnote-1335161459
Ref: Library<156>-Footnote-1345161526
Ref: Library<156>-Footnote-1355161593
Ref: Library<156>-Footnote-1365161660
Ref: Library<156>-Footnote-1375161737
Ref: Library<156>-Footnote-1385161804
Ref: Library<156>-Footnote-1395161871
Ref: Library<156>-Footnote-1405161938
Ref: Library<156>-Footnote-1415162005
Ref: Library<156>-Footnote-1425162072
Ref: Library<156>-Footnote-1435162139
Ref: Library<156>-Footnote-1445162206
Ref: Library<156>-Footnote-1455162273
Ref: Library<156>-Footnote-1465162340
Ref: Library<156>-Footnote-1475162407
Ref: Library<156>-Footnote-1485162474
Ref: Library<156>-Footnote-1495162541
Ref: Library<156>-Footnote-1505162608
Ref: Library<156>-Footnote-1515162675
Ref: Library<156>-Footnote-1525162742
Ref: Library<156>-Footnote-1535162809
Ref: Library<156>-Footnote-1545162876
Ref: Library<156>-Footnote-1555162943
Ref: Library<156>-Footnote-1565163010
Ref: Library<156>-Footnote-1575163077
Ref: Library<156>-Footnote-1585163144
Ref: Library<156>-Footnote-1595163211
Ref: Library<156>-Footnote-1605163278
Ref: Library<156>-Footnote-1615163345
Ref: Library<156>-Footnote-1625163412
Ref: Library<156>-Footnote-1635163479
Ref: Library<156>-Footnote-1645163546
Ref: Library<156>-Footnote-1655163613
Ref: Library<156>-Footnote-1665163680
Ref: Library<156>-Footnote-1675163747
Ref: Library<156>-Footnote-1685163814
Ref: Library<156>-Footnote-1695163881
Ref: Library<156>-Footnote-1705163948
Ref: Library<156>-Footnote-1715164015
Ref: Library<156>-Footnote-1725164082
Ref: Library<156>-Footnote-1735164126
Ref: Library<156>-Footnote-1745164193
Ref: Library<156>-Footnote-1755164260
Ref: Library<156>-Footnote-1765164327
Ref: Library<156>-Footnote-1775164394
Ref: Library<156>-Footnote-1785164461
Ref: Library<156>-Footnote-1795164528
Ref: Library<156>-Footnote-1805164595
Ref: Library<156>-Footnote-1815164662
Ref: Library<156>-Footnote-1825164729
Ref: Library<156>-Footnote-1835164796
Ref: Library<156>-Footnote-1845164863
Ref: Library<156>-Footnote-1855164930
Ref: Library<156>-Footnote-1865164997
Ref: Library<156>-Footnote-1875165064
Ref: Library<156>-Footnote-1885165131
Ref: Library<156>-Footnote-1895165198
Ref: Library<156>-Footnote-1905165265
Ref: Library<156>-Footnote-1915165332
Ref: Library<156>-Footnote-1925165399
Ref: Library<156>-Footnote-1935165466
Ref: Library<156>-Footnote-1945165533
Ref: Library<156>-Footnote-1955165600
Ref: Library<156>-Footnote-1965165667
Ref: Library<156>-Footnote-1975165734
Ref: Library<156>-Footnote-1985165801
Ref: Library<156>-Footnote-1995165868
Ref: Library<156>-Footnote-2005165935
Ref: Library<156>-Footnote-2015166002
Ref: Library<156>-Footnote-2025166069
Ref: Library<156>-Footnote-2035166136
Ref: Library<156>-Footnote-2045166203
Ref: Library<156>-Footnote-2055166270
Ref: Library<156>-Footnote-2065166337
Ref: Library<156>-Footnote-2075166404
Ref: Library<156>-Footnote-2085166471
Ref: Library<156>-Footnote-2095166538
Ref: Library<156>-Footnote-2105166605
Ref: Library<156>-Footnote-2115166672
Ref: Library<156>-Footnote-2125166739
Ref: Library<156>-Footnote-2135166806
Ref: Library<156>-Footnote-2145166873
Ref: Library<156>-Footnote-2155166940
Ref: Library<156>-Footnote-2165167007
Ref: Library<156>-Footnote-2175167074
Ref: Library<156>-Footnote-2185167141
Ref: Library<156>-Footnote-2195167208
Ref: Library<156>-Footnote-2205167275
Ref: Library<156>-Footnote-2215167342
Ref: Library<156>-Footnote-2225167409
Ref: Library<156>-Footnote-2235167476
Ref: Library<156>-Footnote-2245167543
Ref: Library<156>-Footnote-2255167610
Ref: Library<156>-Footnote-2265167677
Ref: Library<156>-Footnote-2275167744
Ref: Library<156>-Footnote-2285167811
Ref: Library<156>-Footnote-2295167878
Ref: Library<156>-Footnote-2305167945
Ref: Library<156>-Footnote-2315168012
Ref: Library<156>-Footnote-2325168079
Ref: Library<156>-Footnote-2335168146
Ref: Library<156>-Footnote-2345168213
Ref: Library<156>-Footnote-2355168280
Ref: Library<156>-Footnote-2365168347
Ref: Library<156>-Footnote-2375168414
Ref: Library<156>-Footnote-2385168481
Ref: Library<156>-Footnote-2395168548
Ref: Library<156>-Footnote-2405168614
Ref: Library<156>-Footnote-2415168681
Ref: Library<156>-Footnote-2425168748
Ref: Library<156>-Footnote-2435168815
Ref: Library<156>-Footnote-2445168882
Ref: Library<156>-Footnote-2455168949
Ref: Library<156>-Footnote-2465169016
Ref: Library<156>-Footnote-2475169083
Ref: Library<156>-Footnote-2485169150
Ref: Library<156>-Footnote-2495169217
Ref: Library<156>-Footnote-2505169284
Ref: Library<156>-Footnote-2515169351
Ref: Library<156>-Footnote-2525169418
Ref: Library<156>-Footnote-2535169485
Node: Documentation<50>5169551
Ref: whatsnew/changelog id6935169664
Ref: 1d9f5169664
Ref: Documentation<50>-Footnote-15174132
Ref: Documentation<50>-Footnote-25174197
Ref: Documentation<50>-Footnote-35174262
Ref: Documentation<50>-Footnote-45174327
Ref: Documentation<50>-Footnote-55174392
Ref: Documentation<50>-Footnote-65174457
Ref: Documentation<50>-Footnote-75174522
Ref: Documentation<50>-Footnote-85174587
Ref: Documentation<50>-Footnote-95174652
Ref: Documentation<50>-Footnote-105174717
Ref: Documentation<50>-Footnote-115174783
Ref: Documentation<50>-Footnote-125174849
Ref: Documentation<50>-Footnote-135174915
Ref: Documentation<50>-Footnote-145174981
Ref: Documentation<50>-Footnote-155175047
Ref: Documentation<50>-Footnote-165175113
Ref: Documentation<50>-Footnote-175175179
Ref: Documentation<50>-Footnote-185175245
Ref: Documentation<50>-Footnote-195175311
Ref: Documentation<50>-Footnote-205175377
Ref: Documentation<50>-Footnote-215175443
Ref: Documentation<50>-Footnote-225175509
Ref: Documentation<50>-Footnote-235175575
Ref: Documentation<50>-Footnote-245175641
Ref: Documentation<50>-Footnote-255175707
Ref: Documentation<50>-Footnote-265175773
Ref: Documentation<50>-Footnote-275175839
Ref: Documentation<50>-Footnote-285175905
Ref: Documentation<50>-Footnote-295175971
Ref: Documentation<50>-Footnote-305176037
Ref: Documentation<50>-Footnote-315176103
Ref: Documentation<50>-Footnote-325176169
Ref: Documentation<50>-Footnote-335176235
Ref: Documentation<50>-Footnote-345176301
Ref: Documentation<50>-Footnote-355176367
Node: Tests<49>5176433
Ref: whatsnew/changelog id6945176543
Ref: 1da15176543
Ref: Tests<49>-Footnote-15184660
Ref: Tests<49>-Footnote-25184725
Ref: Tests<49>-Footnote-35184790
Ref: Tests<49>-Footnote-45184855
Ref: Tests<49>-Footnote-55184920
Ref: Tests<49>-Footnote-65184985
Ref: Tests<49>-Footnote-75185050
Ref: Tests<49>-Footnote-85185115
Ref: Tests<49>-Footnote-95185180
Ref: Tests<49>-Footnote-105185245
Ref: Tests<49>-Footnote-115185311
Ref: Tests<49>-Footnote-125185377
Ref: Tests<49>-Footnote-135185443
Ref: Tests<49>-Footnote-145185509
Ref: Tests<49>-Footnote-155185575
Ref: Tests<49>-Footnote-165185641
Ref: Tests<49>-Footnote-175185707
Ref: Tests<49>-Footnote-185185773
Ref: Tests<49>-Footnote-195185839
Ref: Tests<49>-Footnote-205185905
Ref: Tests<49>-Footnote-215185971
Ref: Tests<49>-Footnote-225186037
Ref: Tests<49>-Footnote-235186103
Ref: Tests<49>-Footnote-245186169
Ref: Tests<49>-Footnote-255186235
Ref: Tests<49>-Footnote-265186301
Ref: Tests<49>-Footnote-275186367
Ref: Tests<49>-Footnote-285186433
Ref: Tests<49>-Footnote-295186499
Ref: Tests<49>-Footnote-305186565
Ref: Tests<49>-Footnote-315186631
Ref: Tests<49>-Footnote-325186697
Ref: Tests<49>-Footnote-335186763
Ref: Tests<49>-Footnote-345186829
Ref: Tests<49>-Footnote-355186895
Ref: Tests<49>-Footnote-365186961
Ref: Tests<49>-Footnote-375187027
Ref: Tests<49>-Footnote-385187093
Ref: Tests<49>-Footnote-395187159
Ref: Tests<49>-Footnote-405187225
Ref: Tests<49>-Footnote-415187291
Ref: Tests<49>-Footnote-425187357
Ref: Tests<49>-Footnote-435187423
Ref: Tests<49>-Footnote-445187489
Ref: Tests<49>-Footnote-455187555
Ref: Tests<49>-Footnote-465187621
Ref: Tests<49>-Footnote-475187687
Ref: Tests<49>-Footnote-485187753
Node: Build<57>5187819
Ref: whatsnew/changelog id6955187923
Ref: 1da75187923
Ref: Build<57>-Footnote-15191750
Ref: Build<57>-Footnote-25191815
Ref: Build<57>-Footnote-35191880
Ref: Build<57>-Footnote-45191945
Ref: Build<57>-Footnote-55192010
Ref: Build<57>-Footnote-65192075
Ref: Build<57>-Footnote-75192140
Ref: Build<57>-Footnote-85192205
Ref: Build<57>-Footnote-95192270
Ref: Build<57>-Footnote-105192335
Ref: Build<57>-Footnote-115192401
Ref: Build<57>-Footnote-125192467
Ref: Build<57>-Footnote-135192533
Ref: Build<57>-Footnote-145192599
Ref: Build<57>-Footnote-155192665
Ref: Build<57>-Footnote-165192731
Node: Windows<49>5192797
Ref: whatsnew/changelog id6965192901
Ref: 1da95192901
Ref: Windows<49>-Footnote-15197809
Ref: Windows<49>-Footnote-25197874
Ref: Windows<49>-Footnote-35197939
Ref: Windows<49>-Footnote-45198004
Ref: Windows<49>-Footnote-55198069
Ref: Windows<49>-Footnote-65198134
Ref: Windows<49>-Footnote-75198199
Ref: Windows<49>-Footnote-85198264
Ref: Windows<49>-Footnote-95198329
Ref: Windows<49>-Footnote-105198394
Ref: Windows<49>-Footnote-115198460
Ref: Windows<49>-Footnote-125198526
Ref: Windows<49>-Footnote-135198592
Ref: Windows<49>-Footnote-145198658
Ref: Windows<49>-Footnote-155198724
Ref: Windows<49>-Footnote-165198790
Ref: Windows<49>-Footnote-175198856
Ref: Windows<49>-Footnote-185198922
Ref: Windows<49>-Footnote-195198988
Ref: Windows<49>-Footnote-205199054
Ref: Windows<49>-Footnote-215199120
Ref: Windows<49>-Footnote-225199186
Ref: Windows<49>-Footnote-235199252
Ref: Windows<49>-Footnote-245199317
Ref: Windows<49>-Footnote-255199382
Ref: Windows<49>-Footnote-265199448
Ref: Windows<49>-Footnote-275199514
Ref: Windows<49>-Footnote-285199580
Ref: Windows<49>-Footnote-295199646
Ref: Windows<49>-Footnote-305199712
Ref: Windows<49>-Footnote-315199778
Ref: Windows<49>-Footnote-325199844
Ref: Windows<49>-Footnote-335199910
Ref: Windows<49>-Footnote-345199976
Ref: Windows<49>-Footnote-355200042
Ref: Windows<49>-Footnote-365200108
Ref: Windows<49>-Footnote-375200174
Ref: Windows<49>-Footnote-385200240
Ref: Windows<49>-Footnote-395200306
Ref: Windows<49>-Footnote-405200372
Ref: Windows<49>-Footnote-415200438
Ref: Windows<49>-Footnote-425200504
Node: macOS<38>5200570
Ref: whatsnew/changelog id6975200673
Ref: 1dac5200673
Ref: macOS<38>-Footnote-15201506
Ref: macOS<38>-Footnote-25201571
Ref: macOS<38>-Footnote-35201636
Ref: macOS<38>-Footnote-45201701
Ref: macOS<38>-Footnote-55201766
Ref: macOS<38>-Footnote-65201831
Node: IDLE<32>5201896
Ref: whatsnew/changelog id6985202003
Ref: 1dad5202003
Ref: IDLE<32>-Footnote-15206738
Ref: IDLE<32>-Footnote-25206803
Ref: IDLE<32>-Footnote-35206867
Ref: IDLE<32>-Footnote-45206932
Ref: IDLE<32>-Footnote-55206997
Ref: IDLE<32>-Footnote-65207062
Ref: IDLE<32>-Footnote-75207127
Ref: IDLE<32>-Footnote-85207192
Ref: IDLE<32>-Footnote-95207257
Ref: IDLE<32>-Footnote-105207322
Ref: IDLE<32>-Footnote-115207388
Ref: IDLE<32>-Footnote-125207454
Ref: IDLE<32>-Footnote-135207520
Ref: IDLE<32>-Footnote-145207586
Ref: IDLE<32>-Footnote-155207652
Ref: IDLE<32>-Footnote-165207718
Ref: IDLE<32>-Footnote-175207784
Ref: IDLE<32>-Footnote-185207850
Ref: IDLE<32>-Footnote-195207916
Ref: IDLE<32>-Footnote-205207982
Ref: IDLE<32>-Footnote-215208048
Ref: IDLE<32>-Footnote-225208114
Ref: IDLE<32>-Footnote-235208180
Ref: IDLE<32>-Footnote-245208246
Ref: IDLE<32>-Footnote-255208312
Ref: IDLE<32>-Footnote-265208378
Ref: IDLE<32>-Footnote-275208444
Ref: IDLE<32>-Footnote-285208510
Ref: IDLE<32>-Footnote-295208576
Ref: IDLE<32>-Footnote-305208641
Node: Tools/Demos<33>5208707
Ref: whatsnew/changelog id6995208814
Ref: 1dae5208814
Ref: Tools/Demos<33>-Footnote-15209815
Ref: Tools/Demos<33>-Footnote-25209880
Ref: Tools/Demos<33>-Footnote-35209945
Ref: Tools/Demos<33>-Footnote-45210010
Ref: Tools/Demos<33>-Footnote-55210075
Ref: Tools/Demos<33>-Footnote-65210140
Ref: Tools/Demos<33>-Footnote-75210205
Ref: Tools/Demos<33>-Footnote-85210270
Node: C API<52>5210335
Ref: whatsnew/changelog id7005210425
Ref: 1db05210425
Ref: C API<52>-Footnote-15215820
Ref: C API<52>-Footnote-25215885
Ref: C API<52>-Footnote-35215950
Ref: C API<52>-Footnote-45216015
Ref: C API<52>-Footnote-55216080
Ref: C API<52>-Footnote-65216145
Ref: C API<52>-Footnote-75216210
Ref: C API<52>-Footnote-85216275
Ref: C API<52>-Footnote-95216340
Ref: C API<52>-Footnote-105216405
Ref: C API<52>-Footnote-115216471
Ref: C API<52>-Footnote-125216537
Ref: C API<52>-Footnote-135216603
Ref: C API<52>-Footnote-145216669
Ref: C API<52>-Footnote-155216712
Ref: C API<52>-Footnote-165216778
Ref: C API<52>-Footnote-175216844
Ref: C API<52>-Footnote-185216910
Ref: C API<52>-Footnote-195216976
Ref: C API<52>-Footnote-205217042
Ref: C API<52>-Footnote-215217108
Ref: C API<52>-Footnote-225217174
Ref: C API<52>-Footnote-235217240
Ref: C API<52>-Footnote-245217306
Ref: C API<52>-Footnote-255217372
Ref: C API<52>-Footnote-265217438
Ref: C API<52>-Footnote-275217504
Ref: C API<52>-Footnote-285217570
Ref: C API<52>-Footnote-295217636
Ref: C API<52>-Footnote-305217702
Ref: C API<52>-Footnote-315217768
Ref: C API<52>-Footnote-325217834
Ref: C API<52>-Footnote-335217900
Ref: C API<52>-Footnote-345217966
Node: Python 3 8 0 beta 15218032
Ref: whatsnew/changelog python-3-8-0-beta-15218155
Ref: 1db35218155
Node: Security<43>5218536
Ref: whatsnew/changelog id7015218635
Ref: 1db45218635
Ref: Security<43>-Footnote-15219229
Ref: Security<43>-Footnote-25219294
Ref: Security<43>-Footnote-35219349
Ref: Security<43>-Footnote-45219414
Node: Core and Builtins<154>5219479
Ref: whatsnew/changelog id7025219599
Ref: 1db55219599
Ref: Core and Builtins<154>-Footnote-15227655
Ref: Core and Builtins<154>-Footnote-25227720
Ref: Core and Builtins<154>-Footnote-35227785
Ref: Core and Builtins<154>-Footnote-45227850
Ref: Core and Builtins<154>-Footnote-55227915
Ref: Core and Builtins<154>-Footnote-65227980
Ref: Core and Builtins<154>-Footnote-75228045
Ref: Core and Builtins<154>-Footnote-85228110
Ref: Core and Builtins<154>-Footnote-95228175
Ref: Core and Builtins<154>-Footnote-105228240
Ref: Core and Builtins<154>-Footnote-115228306
Ref: Core and Builtins<154>-Footnote-125228372
Ref: Core and Builtins<154>-Footnote-135228438
Ref: Core and Builtins<154>-Footnote-145228504
Ref: Core and Builtins<154>-Footnote-155228570
Ref: Core and Builtins<154>-Footnote-165228636
Ref: Core and Builtins<154>-Footnote-175228702
Ref: Core and Builtins<154>-Footnote-185228768
Ref: Core and Builtins<154>-Footnote-195228833
Ref: Core and Builtins<154>-Footnote-205228899
Ref: Core and Builtins<154>-Footnote-215228965
Ref: Core and Builtins<154>-Footnote-225229031
Ref: Core and Builtins<154>-Footnote-235229096
Ref: Core and Builtins<154>-Footnote-245229162
Ref: Core and Builtins<154>-Footnote-255229228
Ref: Core and Builtins<154>-Footnote-265229294
Ref: Core and Builtins<154>-Footnote-275229360
Ref: Core and Builtins<154>-Footnote-285229426
Ref: Core and Builtins<154>-Footnote-295229492
Ref: Core and Builtins<154>-Footnote-305229558
Ref: Core and Builtins<154>-Footnote-315229624
Ref: Core and Builtins<154>-Footnote-325229690
Ref: Core and Builtins<154>-Footnote-335229756
Ref: Core and Builtins<154>-Footnote-345229822
Ref: Core and Builtins<154>-Footnote-355229888
Ref: Core and Builtins<154>-Footnote-365229954
Ref: Core and Builtins<154>-Footnote-375230020
Ref: Core and Builtins<154>-Footnote-385230086
Ref: Core and Builtins<154>-Footnote-395230152
Ref: Core and Builtins<154>-Footnote-405230218
Ref: Core and Builtins<154>-Footnote-415230284
Ref: Core and Builtins<154>-Footnote-425230350
Ref: Core and Builtins<154>-Footnote-435230416
Ref: Core and Builtins<154>-Footnote-445230482
Node: Library<157>5230548
Ref: whatsnew/changelog id7035230673
Ref: 1db85230673
Ref: Library<157>-Footnote-15248934
Ref: Library<157>-Footnote-25248999
Ref: Library<157>-Footnote-35249064
Ref: Library<157>-Footnote-45249129
Ref: Library<157>-Footnote-55249194
Ref: Library<157>-Footnote-65249259
Ref: Library<157>-Footnote-75249324
Ref: Library<157>-Footnote-85249389
Ref: Library<157>-Footnote-95249454
Ref: Library<157>-Footnote-105249519
Ref: Library<157>-Footnote-115249585
Ref: Library<157>-Footnote-125249651
Ref: Library<157>-Footnote-135249717
Ref: Library<157>-Footnote-145249783
Ref: Library<157>-Footnote-155249849
Ref: Library<157>-Footnote-165249915
Ref: Library<157>-Footnote-175249981
Ref: Library<157>-Footnote-185250047
Ref: Library<157>-Footnote-195250113
Ref: Library<157>-Footnote-205250179
Ref: Library<157>-Footnote-215250245
Ref: Library<157>-Footnote-225250311
Ref: Library<157>-Footnote-235250377
Ref: Library<157>-Footnote-245250443
Ref: Library<157>-Footnote-255250511
Ref: Library<157>-Footnote-265250577
Ref: Library<157>-Footnote-275250643
Ref: Library<157>-Footnote-285250709
Ref: Library<157>-Footnote-295250775
Ref: Library<157>-Footnote-305250841
Ref: Library<157>-Footnote-315250907
Ref: Library<157>-Footnote-325250973
Ref: Library<157>-Footnote-335251039
Ref: Library<157>-Footnote-345251105
Ref: Library<157>-Footnote-355251171
Ref: Library<157>-Footnote-365251237
Ref: Library<157>-Footnote-375251303
Ref: Library<157>-Footnote-385251369
Ref: Library<157>-Footnote-395251435
Ref: Library<157>-Footnote-405251501
Ref: Library<157>-Footnote-415251567
Ref: Library<157>-Footnote-425251633
Ref: Library<157>-Footnote-435251699
Ref: Library<157>-Footnote-445251765
Ref: Library<157>-Footnote-455251831
Ref: Library<157>-Footnote-465251897
Ref: Library<157>-Footnote-475251963
Ref: Library<157>-Footnote-485252029
Ref: Library<157>-Footnote-495252095
Ref: Library<157>-Footnote-505252161
Ref: Library<157>-Footnote-515252227
Ref: Library<157>-Footnote-525252293
Ref: Library<157>-Footnote-535252359
Ref: Library<157>-Footnote-545252425
Ref: Library<157>-Footnote-555252491
Ref: Library<157>-Footnote-565252557
Ref: Library<157>-Footnote-575252623
Ref: Library<157>-Footnote-585252689
Ref: Library<157>-Footnote-595252755
Ref: Library<157>-Footnote-605252821
Ref: Library<157>-Footnote-615252887
Ref: Library<157>-Footnote-625252953
Ref: Library<157>-Footnote-635253019
Ref: Library<157>-Footnote-645253085
Ref: Library<157>-Footnote-655253151
Ref: Library<157>-Footnote-665253217
Ref: Library<157>-Footnote-675253283
Ref: Library<157>-Footnote-685253349
Ref: Library<157>-Footnote-695253414
Ref: Library<157>-Footnote-705253480
Ref: Library<157>-Footnote-715253545
Ref: Library<157>-Footnote-725253611
Ref: Library<157>-Footnote-735253677
Ref: Library<157>-Footnote-745253743
Ref: Library<157>-Footnote-755253809
Ref: Library<157>-Footnote-765253875
Ref: Library<157>-Footnote-775253941
Ref: Library<157>-Footnote-785254007
Ref: Library<157>-Footnote-795254073
Ref: Library<157>-Footnote-805254139
Ref: Library<157>-Footnote-815254205
Ref: Library<157>-Footnote-825254271
Ref: Library<157>-Footnote-835254337
Ref: Library<157>-Footnote-845254403
Ref: Library<157>-Footnote-855254469
Ref: Library<157>-Footnote-865254535
Ref: Library<157>-Footnote-875254601
Ref: Library<157>-Footnote-885254667
Ref: Library<157>-Footnote-895254733
Ref: Library<157>-Footnote-905254799
Ref: Library<157>-Footnote-915254865
Ref: Library<157>-Footnote-925254931
Ref: Library<157>-Footnote-935254997
Ref: Library<157>-Footnote-945255063
Ref: Library<157>-Footnote-955255129
Ref: Library<157>-Footnote-965255195
Ref: Library<157>-Footnote-975255261
Ref: Library<157>-Footnote-985255327
Ref: Library<157>-Footnote-995255393
Ref: Library<157>-Footnote-1005255459
Ref: Library<157>-Footnote-1015255526
Ref: Library<157>-Footnote-1025255593
Ref: Library<157>-Footnote-1035255660
Ref: Library<157>-Footnote-1045255727
Ref: Library<157>-Footnote-1055255794
Ref: Library<157>-Footnote-1065255861
Ref: Library<157>-Footnote-1075255928
Node: Documentation<51>5255995
Ref: whatsnew/changelog id7045256107
Ref: 1dbe5256107
Ref: Documentation<51>-Footnote-15258185
Ref: Documentation<51>-Footnote-25258250
Ref: Documentation<51>-Footnote-35258315
Ref: Documentation<51>-Footnote-45258380
Ref: Documentation<51>-Footnote-55258445
Ref: Documentation<51>-Footnote-65258510
Ref: Documentation<51>-Footnote-75258575
Ref: Documentation<51>-Footnote-85258640
Ref: Documentation<51>-Footnote-95258705
Ref: Documentation<51>-Footnote-105258770
Ref: Documentation<51>-Footnote-115258836
Ref: Documentation<51>-Footnote-125258902
Ref: Documentation<51>-Footnote-135258968
Ref: Documentation<51>-Footnote-145259034
Node: Tests<50>5259100
Ref: whatsnew/changelog id7055259209
Ref: 1dbf5259209
Ref: Tests<50>-Footnote-15260845
Ref: Tests<50>-Footnote-25260910
Ref: Tests<50>-Footnote-35260975
Ref: Tests<50>-Footnote-45261040
Ref: Tests<50>-Footnote-55261105
Ref: Tests<50>-Footnote-65261170
Ref: Tests<50>-Footnote-75261235
Ref: Tests<50>-Footnote-85261300
Ref: Tests<50>-Footnote-95261365
Ref: Tests<50>-Footnote-105261430
Node: Build<58>5261496
Ref: whatsnew/changelog id7065261599
Ref: 1dc15261599
Ref: Build<58>-Footnote-15262813
Ref: Build<58>-Footnote-25262878
Node: Windows<50>5262943
Ref: whatsnew/changelog id7075263046
Ref: 1dc25263046
Ref: Windows<50>-Footnote-15263478
Ref: Windows<50>-Footnote-25263543
Ref: Windows<50>-Footnote-35263608
Ref: Windows<50>-Footnote-45263673
Node: macOS<39>5263738
Ref: whatsnew/changelog id7085263840
Ref: 1dc35263840
Ref: macOS<39>-Footnote-15264142
Node: IDLE<33>5264207
Ref: whatsnew/changelog id7095264313
Ref: 1dc45264313
Ref: IDLE<33>-Footnote-15264915
Ref: IDLE<33>-Footnote-25264980
Ref: IDLE<33>-Footnote-35265045
Ref: IDLE<33>-Footnote-45265110
Ref: IDLE<33>-Footnote-55265175
Ref: IDLE<33>-Footnote-65265240
Node: Tools/Demos<34>5265305
Ref: whatsnew/changelog id7105265411
Ref: 1dc55265411
Ref: Tools/Demos<34>-Footnote-15265612
Node: C API<53>5265677
Ref: whatsnew/changelog id7115265766
Ref: 1dc65265766
Ref: C API<53>-Footnote-15267104
Ref: C API<53>-Footnote-25267169
Ref: C API<53>-Footnote-35267211
Ref: C API<53>-Footnote-45267276
Ref: C API<53>-Footnote-55267341
Ref: C API<53>-Footnote-65267406
Ref: C API<53>-Footnote-75267448
Ref: C API<53>-Footnote-85267513
Ref: C API<53>-Footnote-95267578
Node: Python 3 8 0 alpha 45267643
Ref: whatsnew/changelog python-3-8-0-alpha-45267766
Ref: 1dc85267766
Node: Security<44>5268149
Ref: whatsnew/changelog id7125268249
Ref: 1dc95268249
Ref: Security<44>-Footnote-15269134
Ref: Security<44>-Footnote-25269199
Ref: Security<44>-Footnote-35269264
Ref: Security<44>-Footnote-45269319
Node: Core and Builtins<155>5269384
Ref: whatsnew/changelog id7135269505
Ref: 1dca5269505
Ref: Core and Builtins<155>-Footnote-15272781
Ref: Core and Builtins<155>-Footnote-25272846
Ref: Core and Builtins<155>-Footnote-35272911
Ref: Core and Builtins<155>-Footnote-45272976
Ref: Core and Builtins<155>-Footnote-55273041
Ref: Core and Builtins<155>-Footnote-65273106
Ref: Core and Builtins<155>-Footnote-75273171
Ref: Core and Builtins<155>-Footnote-85273236
Ref: Core and Builtins<155>-Footnote-95273301
Ref: Core and Builtins<155>-Footnote-105273343
Ref: Core and Builtins<155>-Footnote-115273409
Ref: Core and Builtins<155>-Footnote-125273475
Ref: Core and Builtins<155>-Footnote-135273541
Ref: Core and Builtins<155>-Footnote-145273607
Ref: Core and Builtins<155>-Footnote-155273673
Ref: Core and Builtins<155>-Footnote-165273739
Ref: Core and Builtins<155>-Footnote-175273805
Ref: Core and Builtins<155>-Footnote-185273871
Ref: Core and Builtins<155>-Footnote-195273937
Ref: Core and Builtins<155>-Footnote-205274003
Node: Library<158>5274069
Ref: whatsnew/changelog id7145274195
Ref: 1dcb5274195
Ref: Library<158>-Footnote-15283521
Ref: Library<158>-Footnote-25283586
Ref: Library<158>-Footnote-35283651
Ref: Library<158>-Footnote-45283716
Ref: Library<158>-Footnote-55283783
Ref: Library<158>-Footnote-65283848
Ref: Library<158>-Footnote-75283913
Ref: Library<158>-Footnote-85283978
Ref: Library<158>-Footnote-95284043
Ref: Library<158>-Footnote-105284108
Ref: Library<158>-Footnote-115284174
Ref: Library<158>-Footnote-125284240
Ref: Library<158>-Footnote-135284306
Ref: Library<158>-Footnote-145284372
Ref: Library<158>-Footnote-155284438
Ref: Library<158>-Footnote-165284504
Ref: Library<158>-Footnote-175284570
Ref: Library<158>-Footnote-185284636
Ref: Library<158>-Footnote-195284702
Ref: Library<158>-Footnote-205284768
Ref: Library<158>-Footnote-215284834
Ref: Library<158>-Footnote-225284900
Ref: Library<158>-Footnote-235284966
Ref: Library<158>-Footnote-245285032
Ref: Library<158>-Footnote-255285098
Ref: Library<158>-Footnote-265285164
Ref: Library<158>-Footnote-275285230
Ref: Library<158>-Footnote-285285296
Ref: Library<158>-Footnote-295285362
Ref: Library<158>-Footnote-305285428
Ref: Library<158>-Footnote-315285494
Ref: Library<158>-Footnote-325285560
Ref: Library<158>-Footnote-335285626
Ref: Library<158>-Footnote-345285692
Ref: Library<158>-Footnote-355285758
Ref: Library<158>-Footnote-365285824
Ref: Library<158>-Footnote-375285890
Ref: Library<158>-Footnote-385285956
Ref: Library<158>-Footnote-395286022
Ref: Library<158>-Footnote-405286088
Ref: Library<158>-Footnote-415286154
Ref: Library<158>-Footnote-425286220
Ref: Library<158>-Footnote-435286286
Ref: Library<158>-Footnote-445286352
Ref: Library<158>-Footnote-455286418
Ref: Library<158>-Footnote-465286484
Ref: Library<158>-Footnote-475286550
Ref: Library<158>-Footnote-485286616
Ref: Library<158>-Footnote-495286682
Ref: Library<158>-Footnote-505286748
Ref: Library<158>-Footnote-515286814
Ref: Library<158>-Footnote-525286880
Ref: Library<158>-Footnote-535286946
Ref: Library<158>-Footnote-545287012
Node: Documentation<52>5287078
Ref: whatsnew/changelog id7155287191
Ref: 1dcf5287191
Ref: Documentation<52>-Footnote-15288642
Ref: Documentation<52>-Footnote-25288707
Ref: Documentation<52>-Footnote-35288772
Ref: Documentation<52>-Footnote-45288837
Ref: Documentation<52>-Footnote-55288902
Ref: Documentation<52>-Footnote-65288941
Ref: Documentation<52>-Footnote-75289006
Ref: Documentation<52>-Footnote-85289071
Ref: Documentation<52>-Footnote-95289136
Ref: Documentation<52>-Footnote-105289201
Ref: Documentation<52>-Footnote-115289267
Ref: Documentation<52>-Footnote-125289333
Node: Tests<51>5289399
Ref: whatsnew/changelog id7165289509
Ref: 1dd05289509
Ref: Tests<51>-Footnote-15291760
Ref: Tests<51>-Footnote-25291825
Ref: Tests<51>-Footnote-35291890
Ref: Tests<51>-Footnote-45291955
Ref: Tests<51>-Footnote-55292020
Ref: Tests<51>-Footnote-65292085
Ref: Tests<51>-Footnote-75292150
Ref: Tests<51>-Footnote-85292215
Ref: Tests<51>-Footnote-95292280
Ref: Tests<51>-Footnote-105292345
Ref: Tests<51>-Footnote-115292411
Ref: Tests<51>-Footnote-125292477
Ref: Tests<51>-Footnote-135292543
Ref: Tests<51>-Footnote-145292609
Ref: Tests<51>-Footnote-155292675
Node: Build<59>5292741
Ref: whatsnew/changelog id7175292845
Ref: 1dd25292845
Ref: Build<59>-Footnote-15296012
Ref: Build<59>-Footnote-25296077
Ref: Build<59>-Footnote-35296142
Ref: Build<59>-Footnote-45296207
Ref: Build<59>-Footnote-55296272
Ref: Build<59>-Footnote-65296337
Ref: Build<59>-Footnote-75296402
Ref: Build<59>-Footnote-85296467
Ref: Build<59>-Footnote-95296532
Ref: Build<59>-Footnote-105296597
Ref: Build<59>-Footnote-115296663
Ref: Build<59>-Footnote-125296729
Ref: Build<59>-Footnote-135296795
Node: Windows<51>5296861
Ref: whatsnew/changelog id7185296965
Ref: 1dd35296965
Ref: Windows<51>-Footnote-15299617
Ref: Windows<51>-Footnote-25299682
Ref: Windows<51>-Footnote-35299747
Ref: Windows<51>-Footnote-45299812
Ref: Windows<51>-Footnote-55299877
Ref: Windows<51>-Footnote-65299942
Ref: Windows<51>-Footnote-75300007
Ref: Windows<51>-Footnote-85300072
Ref: Windows<51>-Footnote-95300137
Ref: Windows<51>-Footnote-105300202
Ref: Windows<51>-Footnote-115300268
Ref: Windows<51>-Footnote-125300334
Node: macOS<40>5300400
Ref: whatsnew/changelog id7195300503
Ref: 1dd45300503
Ref: macOS<40>-Footnote-15300817
Ref: macOS<40>-Footnote-25300882
Node: IDLE<34>5300947
Ref: whatsnew/changelog id7205301054
Ref: 1dd55301054
Ref: IDLE<34>-Footnote-15301301
Node: Tools/Demos<35>5301366
Ref: whatsnew/changelog id7215301473
Ref: 1dd65301473
Ref: Tools/Demos<35>-Footnote-15301627
Node: C API<54>5301692
Ref: whatsnew/changelog id7225301782
Ref: 1dd75301782
Ref: C API<54>-Footnote-15303787
Ref: C API<54>-Footnote-25303852
Ref: C API<54>-Footnote-35303917
Ref: C API<54>-Footnote-45303982
Ref: C API<54>-Footnote-55304047
Ref: C API<54>-Footnote-65304112
Node: Python 3 8 0 alpha 35304177
Ref: whatsnew/changelog python-3-8-0-alpha-35304301
Ref: 1dda5304301
Node: Security<45>5304664
Ref: whatsnew/changelog id7235304764
Ref: 1ddb5304764
Ref: Security<45>-Footnote-15305328
Ref: Security<45>-Footnote-25305393
Node: Core and Builtins<156>5305458
Ref: whatsnew/changelog id7245305579
Ref: 1ddd5305579
Ref: Core and Builtins<156>-Footnote-15309161
Ref: Core and Builtins<156>-Footnote-25309226
Ref: Core and Builtins<156>-Footnote-35309291
Ref: Core and Builtins<156>-Footnote-45309356
Ref: Core and Builtins<156>-Footnote-55309421
Ref: Core and Builtins<156>-Footnote-65309486
Ref: Core and Builtins<156>-Footnote-75309551
Ref: Core and Builtins<156>-Footnote-85309616
Ref: Core and Builtins<156>-Footnote-95309681
Ref: Core and Builtins<156>-Footnote-105309746
Ref: Core and Builtins<156>-Footnote-115309812
Ref: Core and Builtins<156>-Footnote-125309878
Ref: Core and Builtins<156>-Footnote-135309944
Ref: Core and Builtins<156>-Footnote-145310010
Ref: Core and Builtins<156>-Footnote-155310076
Ref: Core and Builtins<156>-Footnote-165310142
Ref: Core and Builtins<156>-Footnote-175310208
Ref: Core and Builtins<156>-Footnote-185310274
Ref: Core and Builtins<156>-Footnote-195310340
Ref: Core and Builtins<156>-Footnote-205310406
Ref: Core and Builtins<156>-Footnote-215310472
Ref: Core and Builtins<156>-Footnote-225310538
Node: Library<159>5310604
Ref: whatsnew/changelog id7255310730
Ref: 1ddf5310730
Ref: Library<159>-Footnote-15316340
Ref: Library<159>-Footnote-25316405
Ref: Library<159>-Footnote-35316470
Ref: Library<159>-Footnote-45316535
Ref: Library<159>-Footnote-55316600
Ref: Library<159>-Footnote-65316665
Ref: Library<159>-Footnote-75316730
Ref: Library<159>-Footnote-85316795
Ref: Library<159>-Footnote-95316860
Ref: Library<159>-Footnote-105316925
Ref: Library<159>-Footnote-115316991
Ref: Library<159>-Footnote-125317057
Ref: Library<159>-Footnote-135317123
Ref: Library<159>-Footnote-145317189
Ref: Library<159>-Footnote-155317255
Ref: Library<159>-Footnote-165317321
Ref: Library<159>-Footnote-175317387
Ref: Library<159>-Footnote-185317453
Ref: Library<159>-Footnote-195317519
Ref: Library<159>-Footnote-205317585
Ref: Library<159>-Footnote-215317651
Ref: Library<159>-Footnote-225317717
Ref: Library<159>-Footnote-235317783
Ref: Library<159>-Footnote-245317849
Ref: Library<159>-Footnote-255317915
Ref: Library<159>-Footnote-265317981
Ref: Library<159>-Footnote-275318047
Ref: Library<159>-Footnote-285318113
Ref: Library<159>-Footnote-295318179
Ref: Library<159>-Footnote-305318245
Ref: Library<159>-Footnote-315318311
Ref: Library<159>-Footnote-325318377
Ref: Library<159>-Footnote-335318443
Ref: Library<159>-Footnote-345318509
Ref: Library<159>-Footnote-355318575
Ref: Library<159>-Footnote-365318641
Ref: Library<159>-Footnote-375318707
Node: Documentation<53>5318773
Ref: whatsnew/changelog id7265318886
Ref: 1de15318886
Ref: Documentation<53>-Footnote-15319457
Ref: Documentation<53>-Footnote-25319522
Ref: Documentation<53>-Footnote-35319587
Node: Tests<52>5319652
Ref: whatsnew/changelog id7275319762
Ref: 1de25319762
Ref: Tests<52>-Footnote-15320274
Ref: Tests<52>-Footnote-25320339
Ref: Tests<52>-Footnote-35320404
Node: Build<60>5320469
Ref: whatsnew/changelog id7285320573
Ref: 1de35320573
Ref: Build<60>-Footnote-15321093
Ref: Build<60>-Footnote-25321158
Ref: Build<60>-Footnote-35321223
Ref: Build<60>-Footnote-45321288
Node: Windows<52>5321353
Ref: whatsnew/changelog id7295321456
Ref: 1de45321456
Ref: Windows<52>-Footnote-15321907
Ref: Windows<52>-Footnote-25321972
Ref: Windows<52>-Footnote-35322037
Node: IDLE<35>5322102
Ref: whatsnew/changelog id7305322211
Ref: 1de55322211
Ref: IDLE<35>-Footnote-15323320
Ref: IDLE<35>-Footnote-25323385
Ref: IDLE<35>-Footnote-35323450
Ref: IDLE<35>-Footnote-45323515
Ref: IDLE<35>-Footnote-55323580
Ref: IDLE<35>-Footnote-65323645
Ref: IDLE<35>-Footnote-75323710
Ref: IDLE<35>-Footnote-85323775
Ref: IDLE<35>-Footnote-95323840
Node: Tools/Demos<36>5323905
Ref: whatsnew/changelog id7315324012
Ref: 1de65324012
Ref: Tools/Demos<36>-Footnote-15324225
Ref: Tools/Demos<36>-Footnote-25324290
Node: C API<55>5324355
Ref: whatsnew/changelog id7325324445
Ref: 1de75324445
Ref: C API<55>-Footnote-15324837
Ref: C API<55>-Footnote-25324902
Node: Python 3 8 0 alpha 25324967
Ref: whatsnew/changelog python-3-8-0-alpha-25325091
Ref: 1de85325091
Node: Core and Builtins<157>5325356
Ref: whatsnew/changelog id7335325456
Ref: 1de95325456
Ref: Core and Builtins<157>-Footnote-15328595
Ref: Core and Builtins<157>-Footnote-25328660
Ref: Core and Builtins<157>-Footnote-35328725
Ref: Core and Builtins<157>-Footnote-45328790
Ref: Core and Builtins<157>-Footnote-55328855
Ref: Core and Builtins<157>-Footnote-65328922
Ref: Core and Builtins<157>-Footnote-75328987
Ref: Core and Builtins<157>-Footnote-85329052
Ref: Core and Builtins<157>-Footnote-95329117
Ref: Core and Builtins<157>-Footnote-105329182
Ref: Core and Builtins<157>-Footnote-115329248
Ref: Core and Builtins<157>-Footnote-125329314
Ref: Core and Builtins<157>-Footnote-135329380
Ref: Core and Builtins<157>-Footnote-145329446
Ref: Core and Builtins<157>-Footnote-155329512
Ref: Core and Builtins<157>-Footnote-165329578
Ref: Core and Builtins<157>-Footnote-175329644
Node: Library<160>5329710
Ref: whatsnew/changelog id7345329836
Ref: 1dea5329836
Ref: Library<160>-Footnote-15333551
Ref: Library<160>-Footnote-25333616
Ref: Library<160>-Footnote-35333681
Ref: Library<160>-Footnote-45333746
Ref: Library<160>-Footnote-55333811
Ref: Library<160>-Footnote-65333876
Ref: Library<160>-Footnote-75333941
Ref: Library<160>-Footnote-85334006
Ref: Library<160>-Footnote-95334071
Ref: Library<160>-Footnote-105334136
Ref: Library<160>-Footnote-115334202
Ref: Library<160>-Footnote-125334268
Ref: Library<160>-Footnote-135334334
Ref: Library<160>-Footnote-145334400
Ref: Library<160>-Footnote-155334466
Ref: Library<160>-Footnote-165334532
Ref: Library<160>-Footnote-175334598
Node: Documentation<54>5334664
Ref: whatsnew/changelog id7355334777
Ref: 1dec5334777
Ref: Documentation<54>-Footnote-15335155
Ref: Documentation<54>-Footnote-25335220
Ref: Documentation<54>-Footnote-35335285
Node: Tests<53>5335350
Ref: whatsnew/changelog id7365335462
Ref: 1ded5335462
Ref: Tests<53>-Footnote-15336827
Ref: Tests<53>-Footnote-25336892
Ref: Tests<53>-Footnote-35336957
Ref: Tests<53>-Footnote-45337022
Ref: Tests<53>-Footnote-55337087
Ref: Tests<53>-Footnote-65337152
Ref: Tests<53>-Footnote-75337217
Ref: Tests<53>-Footnote-85337282
Node: Windows<53>5337347
Ref: whatsnew/changelog id7375337450
Ref: 1dee5337450
Ref: Windows<53>-Footnote-15338047
Ref: Windows<53>-Footnote-25338112
Ref: Windows<53>-Footnote-35338177
Ref: Windows<53>-Footnote-45338242
Ref: Windows<53>-Footnote-55338307
Node: IDLE<36>5338372
Ref: whatsnew/changelog id7385338457
Ref: 1def5338457
Ref: IDLE<36>-Footnote-15338763
Ref: IDLE<36>-Footnote-25338828
Ref: IDLE<36>-Footnote-35338893
Node: Python 3 8 0 alpha 15338958
Ref: whatsnew/changelog python-3-8-0-alpha-15339080
Ref: 1df05339080
Node: Security<46>5339463
Ref: whatsnew/changelog id7395339563
Ref: 1df15339563
Ref: Security<46>-Footnote-15341903
Ref: Security<46>-Footnote-25341968
Ref: Security<46>-Footnote-35342023
Ref: Security<46>-Footnote-45342088
Ref: Security<46>-Footnote-55342153
Ref: Security<46>-Footnote-65342218
Ref: Security<46>-Footnote-75342283
Ref: Security<46>-Footnote-85342339
Ref: Security<46>-Footnote-95342404
Ref: Security<46>-Footnote-105342469
Ref: Security<46>-Footnote-115342535
Ref: Security<46>-Footnote-125342601
Ref: Security<46>-Footnote-135342657
Ref: Security<46>-Footnote-145342723
Ref: Security<46>-Footnote-155342789
Ref: Security<46>-Footnote-165342845
Ref: Security<46>-Footnote-175342901
Node: Core and Builtins<158>5342967
Ref: whatsnew/changelog id7405343088
Ref: 1df25343088
Ref: Core and Builtins<158>-Footnote-15369220
Ref: Core and Builtins<158>-Footnote-25369285
Ref: Core and Builtins<158>-Footnote-35369350
Ref: Core and Builtins<158>-Footnote-45369415
Ref: Core and Builtins<158>-Footnote-55369480
Ref: Core and Builtins<158>-Footnote-65369545
Ref: Core and Builtins<158>-Footnote-75369610
Ref: Core and Builtins<158>-Footnote-85369675
Ref: Core and Builtins<158>-Footnote-95369740
Ref: Core and Builtins<158>-Footnote-105369805
Ref: Core and Builtins<158>-Footnote-115369871
Ref: Core and Builtins<158>-Footnote-125369937
Ref: Core and Builtins<158>-Footnote-135370003
Ref: Core and Builtins<158>-Footnote-145370069
Ref: Core and Builtins<158>-Footnote-155370135
Ref: Core and Builtins<158>-Footnote-165370201
Ref: Core and Builtins<158>-Footnote-175370267
Ref: Core and Builtins<158>-Footnote-185370333
Ref: Core and Builtins<158>-Footnote-195370399
Ref: Core and Builtins<158>-Footnote-205370465
Ref: Core and Builtins<158>-Footnote-215370531
Ref: Core and Builtins<158>-Footnote-225370597
Ref: Core and Builtins<158>-Footnote-235370663
Ref: Core and Builtins<158>-Footnote-245370729
Ref: Core and Builtins<158>-Footnote-255370795
Ref: Core and Builtins<158>-Footnote-265370838
Ref: Core and Builtins<158>-Footnote-275370904
Ref: Core and Builtins<158>-Footnote-285370970
Ref: Core and Builtins<158>-Footnote-295371036
Ref: Core and Builtins<158>-Footnote-305371102
Ref: Core and Builtins<158>-Footnote-315371168
Ref: Core and Builtins<158>-Footnote-325371234
Ref: Core and Builtins<158>-Footnote-335371300
Ref: Core and Builtins<158>-Footnote-345371366
Ref: Core and Builtins<158>-Footnote-355371432
Ref: Core and Builtins<158>-Footnote-365371498
Ref: Core and Builtins<158>-Footnote-375371564
Ref: Core and Builtins<158>-Footnote-385371630
Ref: Core and Builtins<158>-Footnote-395371696
Ref: Core and Builtins<158>-Footnote-405371762
Ref: Core and Builtins<158>-Footnote-415371828
Ref: Core and Builtins<158>-Footnote-425371894
Ref: Core and Builtins<158>-Footnote-435371960
Ref: Core and Builtins<158>-Footnote-445372026
Ref: Core and Builtins<158>-Footnote-455372092
Ref: Core and Builtins<158>-Footnote-465372158
Ref: Core and Builtins<158>-Footnote-475372224
Ref: Core and Builtins<158>-Footnote-485372290
Ref: Core and Builtins<158>-Footnote-495372356
Ref: Core and Builtins<158>-Footnote-505372422
Ref: Core and Builtins<158>-Footnote-515372488
Ref: Core and Builtins<158>-Footnote-525372554
Ref: Core and Builtins<158>-Footnote-535372620
Ref: Core and Builtins<158>-Footnote-545372686
Ref: Core and Builtins<158>-Footnote-555372752
Ref: Core and Builtins<158>-Footnote-565372818
Ref: Core and Builtins<158>-Footnote-575372884
Ref: Core and Builtins<158>-Footnote-585372950
Ref: Core and Builtins<158>-Footnote-595373016
Ref: Core and Builtins<158>-Footnote-605373081
Ref: Core and Builtins<158>-Footnote-615373147
Ref: Core and Builtins<158>-Footnote-625373213
Ref: Core and Builtins<158>-Footnote-635373279
Ref: Core and Builtins<158>-Footnote-645373345
Ref: Core and Builtins<158>-Footnote-655373411
Ref: Core and Builtins<158>-Footnote-665373477
Ref: Core and Builtins<158>-Footnote-675373543
Ref: Core and Builtins<158>-Footnote-685373609
Ref: Core and Builtins<158>-Footnote-695373675
Ref: Core and Builtins<158>-Footnote-705373741
Ref: Core and Builtins<158>-Footnote-715373807
Ref: Core and Builtins<158>-Footnote-725373873
Ref: Core and Builtins<158>-Footnote-735373939
Ref: Core and Builtins<158>-Footnote-745374005
Ref: Core and Builtins<158>-Footnote-755374071
Ref: Core and Builtins<158>-Footnote-765374137
Ref: Core and Builtins<158>-Footnote-775374203
Ref: Core and Builtins<158>-Footnote-785374269
Ref: Core and Builtins<158>-Footnote-795374335
Ref: Core and Builtins<158>-Footnote-805374401
Ref: Core and Builtins<158>-Footnote-815374467
Ref: Core and Builtins<158>-Footnote-825374533
Ref: Core and Builtins<158>-Footnote-835374599
Ref: Core and Builtins<158>-Footnote-845374665
Ref: Core and Builtins<158>-Footnote-855374731
Ref: Core and Builtins<158>-Footnote-865374797
Ref: Core and Builtins<158>-Footnote-875374863
Ref: Core and Builtins<158>-Footnote-885374929
Ref: Core and Builtins<158>-Footnote-895374995
Ref: Core and Builtins<158>-Footnote-905375061
Ref: Core and Builtins<158>-Footnote-915375127
Ref: Core and Builtins<158>-Footnote-925375193
Ref: Core and Builtins<158>-Footnote-935375259
Ref: Core and Builtins<158>-Footnote-945375325
Ref: Core and Builtins<158>-Footnote-955375391
Ref: Core and Builtins<158>-Footnote-965375457
Ref: Core and Builtins<158>-Footnote-975375525
Ref: Core and Builtins<158>-Footnote-985375591
Ref: Core and Builtins<158>-Footnote-995375657
Ref: Core and Builtins<158>-Footnote-1005375723
Ref: Core and Builtins<158>-Footnote-1015375790
Ref: Core and Builtins<158>-Footnote-1025375857
Ref: Core and Builtins<158>-Footnote-1035375924
Ref: Core and Builtins<158>-Footnote-1045375991
Ref: Core and Builtins<158>-Footnote-1055376058
Ref: Core and Builtins<158>-Footnote-1065376125
Ref: Core and Builtins<158>-Footnote-1075376192
Ref: Core and Builtins<158>-Footnote-1085376259
Ref: Core and Builtins<158>-Footnote-1095376326
Ref: Core and Builtins<158>-Footnote-1105376393
Ref: Core and Builtins<158>-Footnote-1115376460
Ref: Core and Builtins<158>-Footnote-1125376527
Ref: Core and Builtins<158>-Footnote-1135376594
Ref: Core and Builtins<158>-Footnote-1145376661
Ref: Core and Builtins<158>-Footnote-1155376728
Ref: Core and Builtins<158>-Footnote-1165376795
Ref: Core and Builtins<158>-Footnote-1175376862
Ref: Core and Builtins<158>-Footnote-1185376929
Ref: Core and Builtins<158>-Footnote-1195376996
Ref: Core and Builtins<158>-Footnote-1205377063
Ref: Core and Builtins<158>-Footnote-1215377130
Ref: Core and Builtins<158>-Footnote-1225377197
Ref: Core and Builtins<158>-Footnote-1235377264
Ref: Core and Builtins<158>-Footnote-1245377331
Ref: Core and Builtins<158>-Footnote-1255377398
Ref: Core and Builtins<158>-Footnote-1265377465
Ref: Core and Builtins<158>-Footnote-1275377532
Ref: Core and Builtins<158>-Footnote-1285377599
Ref: Core and Builtins<158>-Footnote-1295377666
Ref: Core and Builtins<158>-Footnote-1305377733
Ref: Core and Builtins<158>-Footnote-1315377800
Ref: Core and Builtins<158>-Footnote-1325377867
Ref: Core and Builtins<158>-Footnote-1335377934
Ref: Core and Builtins<158>-Footnote-1345378001
Ref: Core and Builtins<158>-Footnote-1355378068
Ref: Core and Builtins<158>-Footnote-1365378135
Ref: Core and Builtins<158>-Footnote-1375378202
Ref: Core and Builtins<158>-Footnote-1385378269
Ref: Core and Builtins<158>-Footnote-1395378336
Ref: Core and Builtins<158>-Footnote-1405378403
Ref: Core and Builtins<158>-Footnote-1415378470
Ref: Core and Builtins<158>-Footnote-1425378537
Ref: Core and Builtins<158>-Footnote-1435378604
Ref: Core and Builtins<158>-Footnote-1445378671
Ref: Core and Builtins<158>-Footnote-1455378738
Ref: Core and Builtins<158>-Footnote-1465378805
Ref: Core and Builtins<158>-Footnote-1475378872
Ref: Core and Builtins<158>-Footnote-1485378939
Ref: Core and Builtins<158>-Footnote-1495379006
Ref: Core and Builtins<158>-Footnote-1505379073
Ref: Core and Builtins<158>-Footnote-1515379140
Ref: Core and Builtins<158>-Footnote-1525379207
Ref: Core and Builtins<158>-Footnote-1535379274
Ref: Core and Builtins<158>-Footnote-1545379341
Ref: Core and Builtins<158>-Footnote-1555379408
Ref: Core and Builtins<158>-Footnote-1565379475
Ref: Core and Builtins<158>-Footnote-1575379542
Ref: Core and Builtins<158>-Footnote-1585379609
Ref: Core and Builtins<158>-Footnote-1595379676
Ref: Core and Builtins<158>-Footnote-1605379743
Ref: Core and Builtins<158>-Footnote-1615379810
Ref: Core and Builtins<158>-Footnote-1625379877
Node: Library<161>5379944
Ref: whatsnew/changelog id7415380070
Ref: 1df85380070
Ref: Library<161>-Footnote-15451210
Ref: Library<161>-Footnote-25451275
Ref: Library<161>-Footnote-35451340
Ref: Library<161>-Footnote-45451405
Ref: Library<161>-Footnote-55451470
Ref: Library<161>-Footnote-65451535
Ref: Library<161>-Footnote-75451600
Ref: Library<161>-Footnote-85451665
Ref: Library<161>-Footnote-95451730
Ref: Library<161>-Footnote-105451795
Ref: Library<161>-Footnote-115451861
Ref: Library<161>-Footnote-125451927
Ref: Library<161>-Footnote-135451993
Ref: Library<161>-Footnote-145452059
Ref: Library<161>-Footnote-155452125
Ref: Library<161>-Footnote-165452191
Ref: Library<161>-Footnote-175452257
Ref: Library<161>-Footnote-185452323
Ref: Library<161>-Footnote-195452389
Ref: Library<161>-Footnote-205452455
Ref: Library<161>-Footnote-215452521
Ref: Library<161>-Footnote-225452587
Ref: Library<161>-Footnote-235452653
Ref: Library<161>-Footnote-245452719
Ref: Library<161>-Footnote-255452785
Ref: Library<161>-Footnote-265452851
Ref: Library<161>-Footnote-275452917
Ref: Library<161>-Footnote-285452983
Ref: Library<161>-Footnote-295453049
Ref: Library<161>-Footnote-305453115
Ref: Library<161>-Footnote-315453181
Ref: Library<161>-Footnote-325453247
Ref: Library<161>-Footnote-335453313
Ref: Library<161>-Footnote-345453379
Ref: Library<161>-Footnote-355453445
Ref: Library<161>-Footnote-365453511
Ref: Library<161>-Footnote-375453577
Ref: Library<161>-Footnote-385453643
Ref: Library<161>-Footnote-395453709
Ref: Library<161>-Footnote-405453775
Ref: Library<161>-Footnote-415453841
Ref: Library<161>-Footnote-425453907
Ref: Library<161>-Footnote-435453973
Ref: Library<161>-Footnote-445454039
Ref: Library<161>-Footnote-455454105
Ref: Library<161>-Footnote-465454171
Ref: Library<161>-Footnote-475454237
Ref: Library<161>-Footnote-485454303
Ref: Library<161>-Footnote-495454369
Ref: Library<161>-Footnote-505454435
Ref: Library<161>-Footnote-515454501
Ref: Library<161>-Footnote-525454567
Ref: Library<161>-Footnote-535454633
Ref: Library<161>-Footnote-545454699
Ref: Library<161>-Footnote-555454765
Ref: Library<161>-Footnote-565454831
Ref: Library<161>-Footnote-575454897
Ref: Library<161>-Footnote-585454963
Ref: Library<161>-Footnote-595455029
Ref: Library<161>-Footnote-605455095
Ref: Library<161>-Footnote-615455161
Ref: Library<161>-Footnote-625455227
Ref: Library<161>-Footnote-635455293
Ref: Library<161>-Footnote-645455359
Ref: Library<161>-Footnote-655455425
Ref: Library<161>-Footnote-665455491
Ref: Library<161>-Footnote-675455557
Ref: Library<161>-Footnote-685455623
Ref: Library<161>-Footnote-695455689
Ref: Library<161>-Footnote-705455755
Ref: Library<161>-Footnote-715455821
Ref: Library<161>-Footnote-725455887
Ref: Library<161>-Footnote-735455953
Ref: Library<161>-Footnote-745456019
Ref: Library<161>-Footnote-755456085
Ref: Library<161>-Footnote-765456151
Ref: Library<161>-Footnote-775456217
Ref: Library<161>-Footnote-785456283
Ref: Library<161>-Footnote-795456349
Ref: Library<161>-Footnote-805456415
Ref: Library<161>-Footnote-815456481
Ref: Library<161>-Footnote-825456547
Ref: Library<161>-Footnote-835456613
Ref: Library<161>-Footnote-845456679
Ref: Library<161>-Footnote-855456745
Ref: Library<161>-Footnote-865456811
Ref: Library<161>-Footnote-875456877
Ref: Library<161>-Footnote-885456943
Ref: Library<161>-Footnote-895457009
Ref: Library<161>-Footnote-905457075
Ref: Library<161>-Footnote-915457141
Ref: Library<161>-Footnote-925457207
Ref: Library<161>-Footnote-935457273
Ref: Library<161>-Footnote-945457333
Ref: Library<161>-Footnote-955457399
Ref: Library<161>-Footnote-965457465
Ref: Library<161>-Footnote-975457531
Ref: Library<161>-Footnote-985457597
Ref: Library<161>-Footnote-995457663
Ref: Library<161>-Footnote-1005457729
Ref: Library<161>-Footnote-1015457796
Ref: Library<161>-Footnote-1025457863
Ref: Library<161>-Footnote-1035457930
Ref: Library<161>-Footnote-1045457997
Ref: Library<161>-Footnote-1055458064
Ref: Library<161>-Footnote-1065458131
Ref: Library<161>-Footnote-1075458198
Ref: Library<161>-Footnote-1085458265
Ref: Library<161>-Footnote-1095458332
Ref: Library<161>-Footnote-1105458399
Ref: Library<161>-Footnote-1115458466
Ref: Library<161>-Footnote-1125458533
Ref: Library<161>-Footnote-1135458600
Ref: Library<161>-Footnote-1145458667
Ref: Library<161>-Footnote-1155458734
Ref: Library<161>-Footnote-1165458801
Ref: Library<161>-Footnote-1175458868
Ref: Library<161>-Footnote-1185458935
Ref: Library<161>-Footnote-1195459002
Ref: Library<161>-Footnote-1205459069
Ref: Library<161>-Footnote-1215459136
Ref: Library<161>-Footnote-1225459203
Ref: Library<161>-Footnote-1235459270
Ref: Library<161>-Footnote-1245459337
Ref: Library<161>-Footnote-1255459404
Ref: Library<161>-Footnote-1265459470
Ref: Library<161>-Footnote-1275459537
Ref: Library<161>-Footnote-1285459604
Ref: Library<161>-Footnote-1295459671
Ref: Library<161>-Footnote-1305459738
Ref: Library<161>-Footnote-1315459805
Ref: Library<161>-Footnote-1325459872
Ref: Library<161>-Footnote-1335459939
Ref: Library<161>-Footnote-1345460006
Ref: Library<161>-Footnote-1355460073
Ref: Library<161>-Footnote-1365460140
Ref: Library<161>-Footnote-1375460206
Ref: Library<161>-Footnote-1385460273
Ref: Library<161>-Footnote-1395460340
Ref: Library<161>-Footnote-1405460407
Ref: Library<161>-Footnote-1415460474
Ref: Library<161>-Footnote-1425460541
Ref: Library<161>-Footnote-1435460608
Ref: Library<161>-Footnote-1445460675
Ref: Library<161>-Footnote-1455460742
Ref: Library<161>-Footnote-1465460809
Ref: Library<161>-Footnote-1475460876
Ref: Library<161>-Footnote-1485460943
Ref: Library<161>-Footnote-1495461010
Ref: Library<161>-Footnote-1505461077
Ref: Library<161>-Footnote-1515461144
Ref: Library<161>-Footnote-1525461211
Ref: Library<161>-Footnote-1535461278
Ref: Library<161>-Footnote-1545461345
Ref: Library<161>-Footnote-1555461411
Ref: Library<161>-Footnote-1565461478
Ref: Library<161>-Footnote-1575461545
Ref: Library<161>-Footnote-1585461612
Ref: Library<161>-Footnote-1595461679
Ref: Library<161>-Footnote-1605461746
Ref: Library<161>-Footnote-1615461813
Ref: Library<161>-Footnote-1625461857
Ref: Library<161>-Footnote-1635461924
Ref: Library<161>-Footnote-1645461991
Ref: Library<161>-Footnote-1655462058
Ref: Library<161>-Footnote-1665462124
Ref: Library<161>-Footnote-1675462191
Ref: Library<161>-Footnote-1685462258
Ref: Library<161>-Footnote-1695462325
Ref: Library<161>-Footnote-1705462392
Ref: Library<161>-Footnote-1715462459
Ref: Library<161>-Footnote-1725462526
Ref: Library<161>-Footnote-1735462593
Ref: Library<161>-Footnote-1745462660
Ref: Library<161>-Footnote-1755462726
Ref: Library<161>-Footnote-1765462793
Ref: Library<161>-Footnote-1775462860
Ref: Library<161>-Footnote-1785462927
Ref: Library<161>-Footnote-1795462994
Ref: Library<161>-Footnote-1805463061
Ref: Library<161>-Footnote-1815463127
Ref: Library<161>-Footnote-1825463194
Ref: Library<161>-Footnote-1835463261
Ref: Library<161>-Footnote-1845463328
Ref: Library<161>-Footnote-1855463395
Ref: Library<161>-Footnote-1865463462
Ref: Library<161>-Footnote-1875463529
Ref: Library<161>-Footnote-1885463596
Ref: Library<161>-Footnote-1895463663
Ref: Library<161>-Footnote-1905463730
Ref: Library<161>-Footnote-1915463797
Ref: Library<161>-Footnote-1925463864
Ref: Library<161>-Footnote-1935463931
Ref: Library<161>-Footnote-1945463998
Ref: Library<161>-Footnote-1955464065
Ref: Library<161>-Footnote-1965464132
Ref: Library<161>-Footnote-1975464199
Ref: Library<161>-Footnote-1985464266
Ref: Library<161>-Footnote-1995464333
Ref: Library<161>-Footnote-2005464400
Ref: Library<161>-Footnote-2015464467
Ref: Library<161>-Footnote-2025464534
Ref: Library<161>-Footnote-2035464602
Ref: Library<161>-Footnote-2045464669
Ref: Library<161>-Footnote-2055464736
Ref: Library<161>-Footnote-2065464803
Ref: Library<161>-Footnote-2075464870
Ref: Library<161>-Footnote-2085464937
Ref: Library<161>-Footnote-2095465004
Ref: Library<161>-Footnote-2105465071
Ref: Library<161>-Footnote-2115465138
Ref: Library<161>-Footnote-2125465205
Ref: Library<161>-Footnote-2135465272
Ref: Library<161>-Footnote-2145465316
Ref: Library<161>-Footnote-2155465383
Ref: Library<161>-Footnote-2165465450
Ref: Library<161>-Footnote-2175465517
Ref: Library<161>-Footnote-2185465584
Ref: Library<161>-Footnote-2195465651
Ref: Library<161>-Footnote-2205465718
Ref: Library<161>-Footnote-2215465785
Ref: Library<161>-Footnote-2225465852
Ref: Library<161>-Footnote-2235465919
Ref: Library<161>-Footnote-2245465986
Ref: Library<161>-Footnote-2255466053
Ref: Library<161>-Footnote-2265466120
Ref: Library<161>-Footnote-2275466187
Ref: Library<161>-Footnote-2285466254
Ref: Library<161>-Footnote-2295466321
Ref: Library<161>-Footnote-2305466388
Ref: Library<161>-Footnote-2315466455
Ref: Library<161>-Footnote-2325466522
Ref: Library<161>-Footnote-2335466589
Ref: Library<161>-Footnote-2345466656
Ref: Library<161>-Footnote-2355466723
Ref: Library<161>-Footnote-2365466790
Ref: Library<161>-Footnote-2375466857
Ref: Library<161>-Footnote-2385466924
Ref: Library<161>-Footnote-2395466991
Ref: Library<161>-Footnote-2405467058
Ref: Library<161>-Footnote-2415467125
Ref: Library<161>-Footnote-2425467192
Ref: Library<161>-Footnote-2435467259
Ref: Library<161>-Footnote-2445467326
Ref: Library<161>-Footnote-2455467393
Ref: Library<161>-Footnote-2465467460
Ref: Library<161>-Footnote-2475467527
Ref: Library<161>-Footnote-2485467594
Ref: Library<161>-Footnote-2495467661
Ref: Library<161>-Footnote-2505467728
Ref: Library<161>-Footnote-2515467795
Ref: Library<161>-Footnote-2525467862
Ref: Library<161>-Footnote-2535467929
Ref: Library<161>-Footnote-2545467996
Ref: Library<161>-Footnote-2555468063
Ref: Library<161>-Footnote-2565468130
Ref: Library<161>-Footnote-2575468197
Ref: Library<161>-Footnote-2585468264
Ref: Library<161>-Footnote-2595468331
Ref: Library<161>-Footnote-2605468398
Ref: Library<161>-Footnote-2615468464
Ref: Library<161>-Footnote-2625468531
Ref: Library<161>-Footnote-2635468598
Ref: Library<161>-Footnote-2645468665
Ref: Library<161>-Footnote-2655468732
Ref: Library<161>-Footnote-2665468799
Ref: Library<161>-Footnote-2675468866
Ref: Library<161>-Footnote-2685468933
Ref: Library<161>-Footnote-2695469000
Ref: Library<161>-Footnote-2705469067
Ref: Library<161>-Footnote-2715469134
Ref: Library<161>-Footnote-2725469201
Ref: Library<161>-Footnote-2735469268
Ref: Library<161>-Footnote-2745469335
Ref: Library<161>-Footnote-2755469402
Ref: Library<161>-Footnote-2765469469
Ref: Library<161>-Footnote-2775469536
Ref: Library<161>-Footnote-2785469603
Ref: Library<161>-Footnote-2795469670
Ref: Library<161>-Footnote-2805469737
Ref: Library<161>-Footnote-2815469804
Ref: Library<161>-Footnote-2825469871
Ref: Library<161>-Footnote-2835469938
Ref: Library<161>-Footnote-2845470005
Ref: Library<161>-Footnote-2855470072
Ref: Library<161>-Footnote-2865470139
Ref: Library<161>-Footnote-2875470206
Ref: Library<161>-Footnote-2885470273
Ref: Library<161>-Footnote-2895470340
Ref: Library<161>-Footnote-2905470407
Ref: Library<161>-Footnote-2915470474
Ref: Library<161>-Footnote-2925470541
Ref: Library<161>-Footnote-2935470608
Ref: Library<161>-Footnote-2945470675
Ref: Library<161>-Footnote-2955470742
Ref: Library<161>-Footnote-2965470809
Ref: Library<161>-Footnote-2975470876
Ref: Library<161>-Footnote-2985470943
Ref: Library<161>-Footnote-2995471010
Ref: Library<161>-Footnote-3005471077
Ref: Library<161>-Footnote-3015471144
Ref: Library<161>-Footnote-3025471211
Ref: Library<161>-Footnote-3035471278
Ref: Library<161>-Footnote-3045471345
Ref: Library<161>-Footnote-3055471412
Ref: Library<161>-Footnote-3065471479
Ref: Library<161>-Footnote-3075471546
Ref: Library<161>-Footnote-3085471613
Ref: Library<161>-Footnote-3095471680
Ref: Library<161>-Footnote-3105471747
Ref: Library<161>-Footnote-3115471814
Ref: Library<161>-Footnote-3125471881
Ref: Library<161>-Footnote-3135471948
Ref: Library<161>-Footnote-3145472015
Ref: Library<161>-Footnote-3155472082
Ref: Library<161>-Footnote-3165472149
Ref: Library<161>-Footnote-3175472216
Ref: Library<161>-Footnote-3185472283
Ref: Library<161>-Footnote-3195472350
Ref: Library<161>-Footnote-3205472417
Ref: Library<161>-Footnote-3215472484
Ref: Library<161>-Footnote-3225472551
Ref: Library<161>-Footnote-3235472618
Ref: Library<161>-Footnote-3245472685
Ref: Library<161>-Footnote-3255472752
Ref: Library<161>-Footnote-3265472819
Ref: Library<161>-Footnote-3275472886
Ref: Library<161>-Footnote-3285472953
Ref: Library<161>-Footnote-3295473021
Ref: Library<161>-Footnote-3305473088
Ref: Library<161>-Footnote-3315473155
Ref: Library<161>-Footnote-3325473222
Ref: Library<161>-Footnote-3335473289
Ref: Library<161>-Footnote-3345473356
Ref: Library<161>-Footnote-3355473423
Ref: Library<161>-Footnote-3365473490
Ref: Library<161>-Footnote-3375473557
Ref: Library<161>-Footnote-3385473624
Ref: Library<161>-Footnote-3395473691
Ref: Library<161>-Footnote-3405473758
Ref: Library<161>-Footnote-3415473825
Ref: Library<161>-Footnote-3425473892
Ref: Library<161>-Footnote-3435473959
Ref: Library<161>-Footnote-3445474026
Ref: Library<161>-Footnote-3455474093
Ref: Library<161>-Footnote-3465474137
Ref: Library<161>-Footnote-3475474204
Ref: Library<161>-Footnote-3485474271
Ref: Library<161>-Footnote-3495474338
Ref: Library<161>-Footnote-3505474382
Ref: Library<161>-Footnote-3515474449
Ref: Library<161>-Footnote-3525474516
Ref: Library<161>-Footnote-3535474583
Ref: Library<161>-Footnote-3545474650
Ref: Library<161>-Footnote-3555474717
Ref: Library<161>-Footnote-3565474784
Ref: Library<161>-Footnote-3575474851
Ref: Library<161>-Footnote-3585474918
Ref: Library<161>-Footnote-3595474985
Ref: Library<161>-Footnote-3605475052
Ref: Library<161>-Footnote-3615475119
Ref: Library<161>-Footnote-3625475186
Ref: Library<161>-Footnote-3635475253
Ref: Library<161>-Footnote-3645475320
Ref: Library<161>-Footnote-3655475387
Ref: Library<161>-Footnote-3665475454
Ref: Library<161>-Footnote-3675475521
Ref: Library<161>-Footnote-3685475588
Ref: Library<161>-Footnote-3695475655
Ref: Library<161>-Footnote-3705475722
Ref: Library<161>-Footnote-3715475789
Ref: Library<161>-Footnote-3725475856
Ref: Library<161>-Footnote-3735475923
Ref: Library<161>-Footnote-3745475990
Ref: Library<161>-Footnote-3755476057
Ref: Library<161>-Footnote-3765476124
Ref: Library<161>-Footnote-3775476191
Ref: Library<161>-Footnote-3785476258
Ref: Library<161>-Footnote-3795476325
Ref: Library<161>-Footnote-3805476392
Ref: Library<161>-Footnote-3815476459
Ref: Library<161>-Footnote-3825476526
Ref: Library<161>-Footnote-3835476593
Ref: Library<161>-Footnote-3845476660
Ref: Library<161>-Footnote-3855476727
Ref: Library<161>-Footnote-3865476794
Ref: Library<161>-Footnote-3875476861
Ref: Library<161>-Footnote-3885476928
Ref: Library<161>-Footnote-3895476995
Ref: Library<161>-Footnote-3905477062
Ref: Library<161>-Footnote-3915477129
Ref: Library<161>-Footnote-3925477196
Ref: Library<161>-Footnote-3935477263
Ref: Library<161>-Footnote-3945477330
Ref: Library<161>-Footnote-3955477397
Ref: Library<161>-Footnote-3965477464
Ref: Library<161>-Footnote-3975477531
Ref: Library<161>-Footnote-3985477598
Ref: Library<161>-Footnote-3995477665
Ref: Library<161>-Footnote-4005477732
Ref: Library<161>-Footnote-4015477799
Ref: Library<161>-Footnote-4025477866
Ref: Library<161>-Footnote-4035477933
Ref: Library<161>-Footnote-4045478000
Ref: Library<161>-Footnote-4055478067
Ref: Library<161>-Footnote-4065478134
Ref: Library<161>-Footnote-4075478201
Ref: Library<161>-Footnote-4085478268
Ref: Library<161>-Footnote-4095478335
Ref: Library<161>-Footnote-4105478402
Ref: Library<161>-Footnote-4115478469
Ref: Library<161>-Footnote-4125478536
Ref: Library<161>-Footnote-4135478603
Ref: Library<161>-Footnote-4145478670
Ref: Library<161>-Footnote-4155478737
Ref: Library<161>-Footnote-4165478804
Ref: Library<161>-Footnote-4175478871
Ref: Library<161>-Footnote-4185478938
Ref: Library<161>-Footnote-4195479005
Ref: Library<161>-Footnote-4205479072
Ref: Library<161>-Footnote-4215479139
Ref: Library<161>-Footnote-4225479206
Ref: Library<161>-Footnote-4235479272
Ref: Library<161>-Footnote-4245479339
Ref: Library<161>-Footnote-4255479406
Ref: Library<161>-Footnote-4265479473
Ref: Library<161>-Footnote-4275479540
Ref: Library<161>-Footnote-4285479607
Ref: Library<161>-Footnote-4295479674
Ref: Library<161>-Footnote-4305479741
Ref: Library<161>-Footnote-4315479808
Ref: Library<161>-Footnote-4325479875
Ref: Library<161>-Footnote-4335479942
Ref: Library<161>-Footnote-4345480009
Ref: Library<161>-Footnote-4355480076
Ref: Library<161>-Footnote-4365480143
Ref: Library<161>-Footnote-4375480210
Node: Documentation<55>5480277
Ref: whatsnew/changelog id7425480390
Ref: 1e0f5480390
Ref: Documentation<55>-Footnote-15487081
Ref: Documentation<55>-Footnote-25487146
Ref: Documentation<55>-Footnote-35487211
Ref: Documentation<55>-Footnote-45487276
Ref: Documentation<55>-Footnote-55487341
Ref: Documentation<55>-Footnote-65487406
Ref: Documentation<55>-Footnote-75487471
Ref: Documentation<55>-Footnote-85487536
Ref: Documentation<55>-Footnote-95487601
Ref: Documentation<55>-Footnote-105487666
Ref: Documentation<55>-Footnote-115487732
Ref: Documentation<55>-Footnote-125487798
Ref: Documentation<55>-Footnote-135487864
Ref: Documentation<55>-Footnote-145487930
Ref: Documentation<55>-Footnote-155487996
Ref: Documentation<55>-Footnote-165488062
Ref: Documentation<55>-Footnote-175488128
Ref: Documentation<55>-Footnote-185488194
Ref: Documentation<55>-Footnote-195488260
Ref: Documentation<55>-Footnote-205488326
Ref: Documentation<55>-Footnote-215488392
Ref: Documentation<55>-Footnote-225488458
Ref: Documentation<55>-Footnote-235488524
Ref: Documentation<55>-Footnote-245488567
Ref: Documentation<55>-Footnote-255488633
Ref: Documentation<55>-Footnote-265488699
Ref: Documentation<55>-Footnote-275488765
Ref: Documentation<55>-Footnote-285488831
Ref: Documentation<55>-Footnote-295488897
Ref: Documentation<55>-Footnote-305488940
Ref: Documentation<55>-Footnote-315489006
Ref: Documentation<55>-Footnote-325489072
Ref: Documentation<55>-Footnote-335489138
Ref: Documentation<55>-Footnote-345489204
Ref: Documentation<55>-Footnote-355489270
Ref: Documentation<55>-Footnote-365489336
Ref: Documentation<55>-Footnote-375489402
Ref: Documentation<55>-Footnote-385489468
Ref: Documentation<55>-Footnote-395489534
Ref: Documentation<55>-Footnote-405489600
Ref: Documentation<55>-Footnote-415489666
Ref: Documentation<55>-Footnote-425489732
Ref: Documentation<55>-Footnote-435489798
Ref: Documentation<55>-Footnote-445489864
Ref: Documentation<55>-Footnote-455489930
Ref: Documentation<55>-Footnote-465489996
Ref: Documentation<55>-Footnote-475490062
Ref: Documentation<55>-Footnote-485490128
Ref: Documentation<55>-Footnote-495490194
Ref: Documentation<55>-Footnote-505490260
Ref: Documentation<55>-Footnote-515490325
Ref: Documentation<55>-Footnote-525490391
Ref: Documentation<55>-Footnote-535490457
Ref: Documentation<55>-Footnote-545490523
Ref: Documentation<55>-Footnote-555490589
Ref: Documentation<55>-Footnote-565490655
Ref: Documentation<55>-Footnote-575490720
Ref: Documentation<55>-Footnote-585490786
Ref: Documentation<55>-Footnote-595490852
Node: Tests<54>5490918
Ref: whatsnew/changelog id7435491028
Ref: 1e115491028
Ref: Tests<54>-Footnote-15498650
Ref: Tests<54>-Footnote-25498715
Ref: Tests<54>-Footnote-35498780
Ref: Tests<54>-Footnote-45498845
Ref: Tests<54>-Footnote-55498910
Ref: Tests<54>-Footnote-65498975
Ref: Tests<54>-Footnote-75499040
Ref: Tests<54>-Footnote-85499105
Ref: Tests<54>-Footnote-95499170
Ref: Tests<54>-Footnote-105499235
Ref: Tests<54>-Footnote-115499301
Ref: Tests<54>-Footnote-125499367
Ref: Tests<54>-Footnote-135499433
Ref: Tests<54>-Footnote-145499499
Ref: Tests<54>-Footnote-155499565
Ref: Tests<54>-Footnote-165499631
Ref: Tests<54>-Footnote-175499697
Ref: Tests<54>-Footnote-185499763
Ref: Tests<54>-Footnote-195499829
Ref: Tests<54>-Footnote-205499895
Ref: Tests<54>-Footnote-215499961
Ref: Tests<54>-Footnote-225500027
Ref: Tests<54>-Footnote-235500093
Ref: Tests<54>-Footnote-245500159
Ref: Tests<54>-Footnote-255500225
Ref: Tests<54>-Footnote-265500291
Ref: Tests<54>-Footnote-275500357
Ref: Tests<54>-Footnote-285500423
Ref: Tests<54>-Footnote-295500489
Ref: Tests<54>-Footnote-305500555
Ref: Tests<54>-Footnote-315500621
Ref: Tests<54>-Footnote-325500687
Ref: Tests<54>-Footnote-335500753
Ref: Tests<54>-Footnote-345500819
Ref: Tests<54>-Footnote-355500885
Ref: Tests<54>-Footnote-365500951
Ref: Tests<54>-Footnote-375501017
Ref: Tests<54>-Footnote-385501083
Ref: Tests<54>-Footnote-395501149
Ref: Tests<54>-Footnote-405501215
Ref: Tests<54>-Footnote-415501281
Ref: Tests<54>-Footnote-425501347
Ref: Tests<54>-Footnote-435501413
Ref: Tests<54>-Footnote-445501479
Ref: Tests<54>-Footnote-455501545
Ref: Tests<54>-Footnote-465501611
Ref: Tests<54>-Footnote-475501677
Ref: Tests<54>-Footnote-485501743
Node: Build<61>5501809
Ref: whatsnew/changelog id7445501913
Ref: 1e125501913
Ref: Build<61>-Footnote-15507037
Ref: Build<61>-Footnote-25507102
Ref: Build<61>-Footnote-35507167
Ref: Build<61>-Footnote-45507232
Ref: Build<61>-Footnote-55507297
Ref: Build<61>-Footnote-65507362
Ref: Build<61>-Footnote-75507427
Ref: Build<61>-Footnote-85507492
Ref: Build<61>-Footnote-95507557
Ref: Build<61>-Footnote-105507622
Ref: Build<61>-Footnote-115507688
Ref: Build<61>-Footnote-125507754
Ref: Build<61>-Footnote-135507820
Ref: Build<61>-Footnote-145507886
Ref: Build<61>-Footnote-155507952
Ref: Build<61>-Footnote-165508018
Ref: Build<61>-Footnote-175508084
Ref: Build<61>-Footnote-185508150
Ref: Build<61>-Footnote-195508216
Ref: Build<61>-Footnote-205508282
Ref: Build<61>-Footnote-215508348
Ref: Build<61>-Footnote-225508414
Ref: Build<61>-Footnote-235508480
Ref: Build<61>-Footnote-245508545
Ref: Build<61>-Footnote-255508611
Ref: Build<61>-Footnote-265508677
Ref: Build<61>-Footnote-275508743
Ref: Build<61>-Footnote-285508809
Ref: Build<61>-Footnote-295508875
Ref: Build<61>-Footnote-305508941
Ref: Build<61>-Footnote-315509007
Ref: Build<61>-Footnote-325509073
Ref: Build<61>-Footnote-335509139
Ref: Build<61>-Footnote-345509205
Ref: Build<61>-Footnote-355509271
Ref: Build<61>-Footnote-365509337
Ref: Build<61>-Footnote-375509403
Node: Windows<54>5509469
Ref: whatsnew/changelog id7455509573
Ref: 1e145509573
Ref: Windows<54>-Footnote-15513996
Ref: Windows<54>-Footnote-25514061
Ref: Windows<54>-Footnote-35514126
Ref: Windows<54>-Footnote-45514191
Ref: Windows<54>-Footnote-55514256
Ref: Windows<54>-Footnote-65514321
Ref: Windows<54>-Footnote-75514386
Ref: Windows<54>-Footnote-85514451
Ref: Windows<54>-Footnote-95514516
Ref: Windows<54>-Footnote-105514581
Ref: Windows<54>-Footnote-115514647
Ref: Windows<54>-Footnote-125514713
Ref: Windows<54>-Footnote-135514779
Ref: Windows<54>-Footnote-145514845
Ref: Windows<54>-Footnote-155514911
Ref: Windows<54>-Footnote-165514977
Ref: Windows<54>-Footnote-175515043
Ref: Windows<54>-Footnote-185515109
Ref: Windows<54>-Footnote-195515175
Ref: Windows<54>-Footnote-205515241
Ref: Windows<54>-Footnote-215515307
Ref: Windows<54>-Footnote-225515373
Ref: Windows<54>-Footnote-235515439
Ref: Windows<54>-Footnote-245515505
Ref: Windows<54>-Footnote-255515571
Ref: Windows<54>-Footnote-265515637
Ref: Windows<54>-Footnote-275515703
Ref: Windows<54>-Footnote-285515769
Ref: Windows<54>-Footnote-295515835
Ref: Windows<54>-Footnote-305515901
Ref: Windows<54>-Footnote-315515967
Ref: Windows<54>-Footnote-325516033
Ref: Windows<54>-Footnote-335516099
Ref: Windows<54>-Footnote-345516165
Ref: Windows<54>-Footnote-355516231
Ref: Windows<54>-Footnote-365516297
Ref: Windows<54>-Footnote-375516363
Ref: Windows<54>-Footnote-385516429
Ref: Windows<54>-Footnote-395516495
Ref: Windows<54>-Footnote-405516561
Node: macOS<41>5516626
Ref: whatsnew/changelog id7465516729
Ref: 1e155516729
Ref: macOS<41>-Footnote-15518336
Ref: macOS<41>-Footnote-25518401
Ref: macOS<41>-Footnote-35518466
Ref: macOS<41>-Footnote-45518531
Ref: macOS<41>-Footnote-55518596
Ref: macOS<41>-Footnote-65518661
Ref: macOS<41>-Footnote-75518726
Ref: macOS<41>-Footnote-85518791
Ref: macOS<41>-Footnote-95518856
Ref: macOS<41>-Footnote-105518921
Node: IDLE<37>5518987
Ref: whatsnew/changelog id7475519094
Ref: 1e165519094
Ref: IDLE<37>-Footnote-15527534
Ref: IDLE<37>-Footnote-25527599
Ref: IDLE<37>-Footnote-35527664
Ref: IDLE<37>-Footnote-45527729
Ref: IDLE<37>-Footnote-55527794
Ref: IDLE<37>-Footnote-65527859
Ref: IDLE<37>-Footnote-75527924
Ref: IDLE<37>-Footnote-85527989
Ref: IDLE<37>-Footnote-95528054
Ref: IDLE<37>-Footnote-105528119
Ref: IDLE<37>-Footnote-115528185
Ref: IDLE<37>-Footnote-125528251
Ref: IDLE<37>-Footnote-135528317
Ref: IDLE<37>-Footnote-145528383
Ref: IDLE<37>-Footnote-155528449
Ref: IDLE<37>-Footnote-165528515
Ref: IDLE<37>-Footnote-175528581
Ref: IDLE<37>-Footnote-185528647
Ref: IDLE<37>-Footnote-195528713
Ref: IDLE<37>-Footnote-205528779
Ref: IDLE<37>-Footnote-215528845
Ref: IDLE<37>-Footnote-225528911
Ref: IDLE<37>-Footnote-235528977
Ref: IDLE<37>-Footnote-245529043
Ref: IDLE<37>-Footnote-255529109
Ref: IDLE<37>-Footnote-265529175
Ref: IDLE<37>-Footnote-275529241
Ref: IDLE<37>-Footnote-285529309
Ref: IDLE<37>-Footnote-295529375
Ref: IDLE<37>-Footnote-305529441
Ref: IDLE<37>-Footnote-315529507
Ref: IDLE<37>-Footnote-325529573
Ref: IDLE<37>-Footnote-335529639
Ref: IDLE<37>-Footnote-345529705
Ref: IDLE<37>-Footnote-355529771
Ref: IDLE<37>-Footnote-365529837
Ref: IDLE<37>-Footnote-375529903
Ref: IDLE<37>-Footnote-385529969
Ref: IDLE<37>-Footnote-395530035
Ref: IDLE<37>-Footnote-405530101
Ref: IDLE<37>-Footnote-415530167
Ref: IDLE<37>-Footnote-425530233
Ref: IDLE<37>-Footnote-435530299
Ref: IDLE<37>-Footnote-445530365
Ref: IDLE<37>-Footnote-455530431
Ref: IDLE<37>-Footnote-465530497
Ref: IDLE<37>-Footnote-475530563
Ref: IDLE<37>-Footnote-485530629
Ref: IDLE<37>-Footnote-495530695
Ref: IDLE<37>-Footnote-505530761
Ref: IDLE<37>-Footnote-515530827
Ref: IDLE<37>-Footnote-525530893
Ref: IDLE<37>-Footnote-535530959
Ref: IDLE<37>-Footnote-545531025
Ref: IDLE<37>-Footnote-555531091
Ref: IDLE<37>-Footnote-565531157
Ref: IDLE<37>-Footnote-575531223
Ref: IDLE<37>-Footnote-585531289
Ref: IDLE<37>-Footnote-595531355
Node: Tools/Demos<37>5531421
Ref: whatsnew/changelog id7485531528
Ref: 1e175531528
Ref: Tools/Demos<37>-Footnote-15533177
Ref: Tools/Demos<37>-Footnote-25533242
Ref: Tools/Demos<37>-Footnote-35533307
Ref: Tools/Demos<37>-Footnote-45533372
Ref: Tools/Demos<37>-Footnote-55533437
Ref: Tools/Demos<37>-Footnote-65533502
Ref: Tools/Demos<37>-Footnote-75533567
Ref: Tools/Demos<37>-Footnote-85533632
Ref: Tools/Demos<37>-Footnote-95533697
Ref: Tools/Demos<37>-Footnote-105533762
Ref: Tools/Demos<37>-Footnote-115533828
Ref: Tools/Demos<37>-Footnote-125533894
Node: C API<56>5533960
Ref: whatsnew/changelog id7495534050
Ref: 1e185534050
Ref: C API<56>-Footnote-15537483
Ref: C API<56>-Footnote-25537548
Ref: C API<56>-Footnote-35537613
Ref: C API<56>-Footnote-45537678
Ref: C API<56>-Footnote-55537743
Ref: C API<56>-Footnote-65537808
Ref: C API<56>-Footnote-75537873
Ref: C API<56>-Footnote-85537938
Ref: C API<56>-Footnote-95538003
Ref: C API<56>-Footnote-105538068
Ref: C API<56>-Footnote-115538134
Ref: C API<56>-Footnote-125538200
Ref: C API<56>-Footnote-135538266
Ref: C API<56>-Footnote-145538332
Ref: C API<56>-Footnote-155538398
Ref: C API<56>-Footnote-165538464
Ref: C API<56>-Footnote-175538530
Ref: C API<56>-Footnote-185538596
Ref: C API<56>-Footnote-195538662
Ref: C API<56>-Footnote-205538728
Ref: C API<56>-Footnote-215538794
Ref: C API<56>-Footnote-225538860
Node: Python 3 7 0 final5538926
Ref: whatsnew/changelog python-3-7-0-final5539060
Ref: 1e215539060
Node: Library<162>5539198
Ref: whatsnew/changelog id7505539283
Ref: 1e225539283
Ref: Library<162>-Footnote-15539453
Node: C API<57>5539518
Ref: whatsnew/changelog id7515539603
Ref: 1e245539603
Ref: C API<57>-Footnote-15539814
Node: Python 3 7 0 release candidate 15539879
Ref: whatsnew/changelog python-3-7-0-release-candidate-15540012
Ref: 1e255540012
Node: Core and Builtins<159>5540301
Ref: whatsnew/changelog id7525540413
Ref: 1e265540413
Ref: Core and Builtins<159>-Footnote-15541057
Ref: Core and Builtins<159>-Footnote-25541122
Ref: Core and Builtins<159>-Footnote-35541187
Ref: Core and Builtins<159>-Footnote-45541252
Node: Library<163>5541317
Ref: whatsnew/changelog id7535541455
Ref: 1e275541455
Ref: Library<163>-Footnote-15543153
Ref: Library<163>-Footnote-25543218
Ref: Library<163>-Footnote-35543283
Ref: Library<163>-Footnote-45543348
Ref: Library<163>-Footnote-55543413
Ref: Library<163>-Footnote-65543478
Ref: Library<163>-Footnote-75543543
Ref: Library<163>-Footnote-85543608
Ref: Library<163>-Footnote-95543673
Ref: Library<163>-Footnote-105543738
Ref: Library<163>-Footnote-115543804
Ref: Library<163>-Footnote-125543870
Ref: Library<163>-Footnote-135543936
Node: Documentation<56>5544002
Ref: whatsnew/changelog id7545544127
Ref: 1e285544127
Ref: Documentation<56>-Footnote-15544634
Ref: Documentation<56>-Footnote-25544699
Ref: Documentation<56>-Footnote-35544741
Ref: Documentation<56>-Footnote-45544806
Node: Build<62>5544871
Ref: whatsnew/changelog id7555544995
Ref: 1e295544995
Ref: Build<62>-Footnote-15545257
Node: Windows<55>5545321
Ref: whatsnew/changelog id7565545436
Ref: 1e2a5545436
Ref: Windows<55>-Footnote-15545593
Node: IDLE<38>5545658
Ref: whatsnew/changelog id7575545755
Ref: 1e2b5545755
Ref: IDLE<38>-Footnote-15546975
Ref: IDLE<38>-Footnote-25547040
Ref: IDLE<38>-Footnote-35547105
Ref: IDLE<38>-Footnote-45547170
Ref: IDLE<38>-Footnote-55547235
Ref: IDLE<38>-Footnote-65547300
Node: Python 3 7 0 beta 55547365
Ref: whatsnew/changelog python-3-7-0-beta-55547499
Ref: 1e2c5547499
Node: Core and Builtins<160>5547778
Ref: whatsnew/changelog id7585547877
Ref: 1e2d5547877
Ref: Core and Builtins<160>-Footnote-15549391
Ref: Core and Builtins<160>-Footnote-25549456
Ref: Core and Builtins<160>-Footnote-35549521
Ref: Core and Builtins<160>-Footnote-45549586
Ref: Core and Builtins<160>-Footnote-55549651
Ref: Core and Builtins<160>-Footnote-65549716
Ref: Core and Builtins<160>-Footnote-75549781
Ref: Core and Builtins<160>-Footnote-85549846
Ref: Core and Builtins<160>-Footnote-95549911
Node: Library<164>5549976
Ref: whatsnew/changelog id7595550101
Ref: 1e2e5550101
Ref: Library<164>-Footnote-15555717
Ref: Library<164>-Footnote-25555782
Ref: Library<164>-Footnote-35555847
Ref: Library<164>-Footnote-45555912
Ref: Library<164>-Footnote-55555977
Ref: Library<164>-Footnote-65556042
Ref: Library<164>-Footnote-75556107
Ref: Library<164>-Footnote-85556172
Ref: Library<164>-Footnote-95556237
Ref: Library<164>-Footnote-105556302
Ref: Library<164>-Footnote-115556368
Ref: Library<164>-Footnote-125556434
Ref: Library<164>-Footnote-135556500
Ref: Library<164>-Footnote-145556566
Ref: Library<164>-Footnote-155556632
Ref: Library<164>-Footnote-165556698
Ref: Library<164>-Footnote-175556764
Ref: Library<164>-Footnote-185556830
Ref: Library<164>-Footnote-195556896
Ref: Library<164>-Footnote-205556962
Ref: Library<164>-Footnote-215557028
Ref: Library<164>-Footnote-225557094
Ref: Library<164>-Footnote-235557160
Ref: Library<164>-Footnote-245557226
Ref: Library<164>-Footnote-255557292
Ref: Library<164>-Footnote-265557358
Ref: Library<164>-Footnote-275557424
Ref: Library<164>-Footnote-285557490
Ref: Library<164>-Footnote-295557556
Ref: Library<164>-Footnote-305557622
Ref: Library<164>-Footnote-315557688
Ref: Library<164>-Footnote-325557754
Ref: Library<164>-Footnote-335557820
Ref: Library<164>-Footnote-345557886
Ref: Library<164>-Footnote-355557952
Ref: Library<164>-Footnote-365558018
Ref: Library<164>-Footnote-375558084
Ref: Library<164>-Footnote-385558150
Node: Documentation<57>5558216
Ref: whatsnew/changelog id7605558328
Ref: 1e2f5558328
Ref: Documentation<57>-Footnote-15558798
Ref: Documentation<57>-Footnote-25558863
Ref: Documentation<57>-Footnote-35558928
Ref: Documentation<57>-Footnote-45558970
Ref: Documentation<57>-Footnote-55559035
Ref: Documentation<57>-Footnote-65559100
Node: Tests<55>5559165
Ref: whatsnew/changelog id7615559274
Ref: 1e305559274
Ref: Tests<55>-Footnote-15559623
Ref: Tests<55>-Footnote-25559688
Node: Build<63>5559753
Ref: whatsnew/changelog id7625559854
Ref: 1e315559854
Ref: Build<63>-Footnote-15560333
Ref: Build<63>-Footnote-25560398
Ref: Build<63>-Footnote-35560463
Node: macOS<42>5560528
Ref: whatsnew/changelog id7635560628
Ref: 1e325560628
Ref: macOS<42>-Footnote-15560870
Node: IDLE<39>5560935
Ref: whatsnew/changelog id7645561017
Ref: 1e335561017
Ref: IDLE<39>-Footnote-15561296
Ref: IDLE<39>-Footnote-25561361
Ref: IDLE<39>-Footnote-35561426
Node: Python 3 7 0 beta 45561491
Ref: whatsnew/changelog python-3-7-0-beta-45561612
Ref: 1e345561612
Node: Core and Builtins<161>5561947
Ref: whatsnew/changelog id7655562046
Ref: 1e355562046
Ref: Core and Builtins<161>-Footnote-15563176
Ref: Core and Builtins<161>-Footnote-25563241
Ref: Core and Builtins<161>-Footnote-35563306
Ref: Core and Builtins<161>-Footnote-45563371
Ref: Core and Builtins<161>-Footnote-55563436
Ref: Core and Builtins<161>-Footnote-65563501
Ref: Core and Builtins<161>-Footnote-75563566
Node: Library<165>5563631
Ref: whatsnew/changelog id7665563756
Ref: 1e365563756
Ref: Library<165>-Footnote-15566586
Ref: Library<165>-Footnote-25566651
Ref: Library<165>-Footnote-35566716
Ref: Library<165>-Footnote-45566781
Ref: Library<165>-Footnote-55566847
Ref: Library<165>-Footnote-65566912
Ref: Library<165>-Footnote-75566977
Ref: Library<165>-Footnote-85567042
Ref: Library<165>-Footnote-95567107
Ref: Library<165>-Footnote-105567172
Ref: Library<165>-Footnote-115567238
Ref: Library<165>-Footnote-125567304
Ref: Library<165>-Footnote-135567370
Ref: Library<165>-Footnote-145567436
Ref: Library<165>-Footnote-155567502
Ref: Library<165>-Footnote-165567568
Ref: Library<165>-Footnote-175567634
Ref: Library<165>-Footnote-185567677
Ref: Library<165>-Footnote-195567743
Ref: Library<165>-Footnote-205567809
Ref: Library<165>-Footnote-215567875
Ref: Library<165>-Footnote-225567941
Node: Documentation<58>5568007
Ref: whatsnew/changelog id7675568119
Ref: 1e375568119
Ref: Documentation<58>-Footnote-15568870
Ref: Documentation<58>-Footnote-25568935
Ref: Documentation<58>-Footnote-35569000
Ref: Documentation<58>-Footnote-45569065
Ref: Documentation<58>-Footnote-55569130
Ref: Documentation<58>-Footnote-65569194
Node: Tests<56>5569259
Ref: whatsnew/changelog id7685569368
Ref: 1e385569368
Ref: Tests<56>-Footnote-15569584
Node: Build<64>5569649
Ref: whatsnew/changelog id7695569752
Ref: 1e395569752
Ref: Build<64>-Footnote-15570442
Ref: Build<64>-Footnote-25570507
Ref: Build<64>-Footnote-35570572
Ref: Build<64>-Footnote-45570637
Ref: Build<64>-Footnote-55570702
Node: Windows<56>5570767
Ref: whatsnew/changelog id7705570870
Ref: 1e3a5570870
Ref: Windows<56>-Footnote-15571011
Node: macOS<43>5571076
Ref: whatsnew/changelog id7715571178
Ref: 1e3b5571178
Ref: macOS<43>-Footnote-15571319
Node: IDLE<40>5571384
Ref: whatsnew/changelog id7725571490
Ref: 1e3c5571490
Ref: IDLE<40>-Footnote-15572080
Ref: IDLE<40>-Footnote-25572145
Node: Tools/Demos<38>5572210
Ref: whatsnew/changelog id7735572298
Ref: 1e3d5572298
Ref: Tools/Demos<38>-Footnote-15572906
Ref: Tools/Demos<38>-Footnote-25572971
Ref: Tools/Demos<38>-Footnote-35573036
Ref: Tools/Demos<38>-Footnote-45573101
Node: Python 3 7 0 beta 35573166
Ref: whatsnew/changelog python-3-7-0-beta-35573287
Ref: 1e3e5573287
Node: Security<47>5573668
Ref: whatsnew/changelog id7745573767
Ref: 1e3f5573767
Ref: Security<47>-Footnote-15574399
Ref: Security<47>-Footnote-25574464
Ref: Security<47>-Footnote-35574519
Ref: Security<47>-Footnote-45574584
Ref: Security<47>-Footnote-55574649
Ref: Security<47>-Footnote-65574704
Node: Core and Builtins<162>5574759
Ref: whatsnew/changelog id7755574879
Ref: 1e405574879
Ref: Core and Builtins<162>-Footnote-15576087
Ref: Core and Builtins<162>-Footnote-25576152
Ref: Core and Builtins<162>-Footnote-35576217
Ref: Core and Builtins<162>-Footnote-45576282
Ref: Core and Builtins<162>-Footnote-55576347
Ref: Core and Builtins<162>-Footnote-65576412
Ref: Core and Builtins<162>-Footnote-75576477
Node: Library<166>5576542
Ref: whatsnew/changelog id7765576667
Ref: 1e415576667
Ref: Library<166>-Footnote-15580722
Ref: Library<166>-Footnote-25580787
Ref: Library<166>-Footnote-35580852
Ref: Library<166>-Footnote-45580917
Ref: Library<166>-Footnote-55580982
Ref: Library<166>-Footnote-65581047
Ref: Library<166>-Footnote-75581112
Ref: Library<166>-Footnote-85581177
Ref: Library<166>-Footnote-95581242
Ref: Library<166>-Footnote-105581307
Ref: Library<166>-Footnote-115581373
Ref: Library<166>-Footnote-125581439
Ref: Library<166>-Footnote-135581505
Ref: Library<166>-Footnote-145581571
Ref: Library<166>-Footnote-155581637
Ref: Library<166>-Footnote-165581703
Ref: Library<166>-Footnote-175581769
Ref: Library<166>-Footnote-185581835
Ref: Library<166>-Footnote-195581901
Ref: Library<166>-Footnote-205581967
Ref: Library<166>-Footnote-215582033
Ref: Library<166>-Footnote-225582099
Ref: Library<166>-Footnote-235582165
Ref: Library<166>-Footnote-245582231
Ref: Library<166>-Footnote-255582297
Ref: Library<166>-Footnote-265582363
Ref: Library<166>-Footnote-275582429
Node: Documentation<59>5582495
Ref: whatsnew/changelog id7775582607
Ref: 1e425582607
Ref: Documentation<59>-Footnote-15583244
Ref: Documentation<59>-Footnote-25583309
Ref: Documentation<59>-Footnote-35583374
Ref: Documentation<59>-Footnote-45583439
Ref: Documentation<59>-Footnote-55583504
Node: Tests<57>5583569
Ref: whatsnew/changelog id7785583678
Ref: 1e435583678
Ref: Tests<57>-Footnote-15584011
Ref: Tests<57>-Footnote-25584076
Ref: Tests<57>-Footnote-35584141
Node: Build<65>5584206
Ref: whatsnew/changelog id7795584309
Ref: 1e445584309
Ref: Build<65>-Footnote-15584446
Node: Windows<57>5584511
Ref: whatsnew/changelog id7805584614
Ref: 1e455584614
Ref: Windows<57>-Footnote-15584893
Ref: Windows<57>-Footnote-25584958
Node: macOS<44>5585023
Ref: whatsnew/changelog id7815585125
Ref: 1e465585125
Ref: macOS<44>-Footnote-15585557
Node: IDLE<41>5585622
Ref: whatsnew/changelog id7825585728
Ref: 1e475585728
Ref: IDLE<41>-Footnote-15586442
Ref: IDLE<41>-Footnote-25586507
Node: Tools/Demos<39>5586572
Ref: whatsnew/changelog id7835586678
Ref: 1e485586678
Ref: Tools/Demos<39>-Footnote-15586908
Node: C API<58>5586973
Ref: whatsnew/changelog id7845587062
Ref: 1e495587062
Ref: C API<58>-Footnote-15587446
Ref: C API<58>-Footnote-25587511
Node: Python 3 7 0 beta 25587576
Ref: whatsnew/changelog python-3-7-0-beta-25587697
Ref: 1e4a5587697
Node: Security<48>5588058
Ref: whatsnew/changelog id7855588157
Ref: 1e4b5588157
Ref: Security<48>-Footnote-15588342
Node: Core and Builtins<163>5588407
Ref: whatsnew/changelog id7865588527
Ref: 1e4c5588527
Ref: Core and Builtins<163>-Footnote-15589358
Ref: Core and Builtins<163>-Footnote-25589423
Ref: Core and Builtins<163>-Footnote-35589488
Ref: Core and Builtins<163>-Footnote-45589553
Ref: Core and Builtins<163>-Footnote-55589618
Ref: Core and Builtins<163>-Footnote-65589683
Ref: Core and Builtins<163>-Footnote-75589748
Node: Library<167>5589813
Ref: whatsnew/changelog id7875589938
Ref: 1e4d5589938
Ref: Library<167>-Footnote-15596365
Ref: Library<167>-Footnote-25596430
Ref: Library<167>-Footnote-35596495
Ref: Library<167>-Footnote-45596560
Ref: Library<167>-Footnote-55596625
Ref: Library<167>-Footnote-65596690
Ref: Library<167>-Footnote-75596755
Ref: Library<167>-Footnote-85596820
Ref: Library<167>-Footnote-95596885
Ref: Library<167>-Footnote-105596950
Ref: Library<167>-Footnote-115597016
Ref: Library<167>-Footnote-125597082
Ref: Library<167>-Footnote-135597148
Ref: Library<167>-Footnote-145597214
Ref: Library<167>-Footnote-155597280
Ref: Library<167>-Footnote-165597346
Ref: Library<167>-Footnote-175597412
Ref: Library<167>-Footnote-185597478
Ref: Library<167>-Footnote-195597544
Ref: Library<167>-Footnote-205597610
Ref: Library<167>-Footnote-215597676
Ref: Library<167>-Footnote-225597742
Ref: Library<167>-Footnote-235597808
Ref: Library<167>-Footnote-245597874
Ref: Library<167>-Footnote-255597940
Ref: Library<167>-Footnote-265598006
Ref: Library<167>-Footnote-275598072
Ref: Library<167>-Footnote-285598138
Ref: Library<167>-Footnote-295598204
Ref: Library<167>-Footnote-305598270
Ref: Library<167>-Footnote-315598336
Ref: Library<167>-Footnote-325598402
Ref: Library<167>-Footnote-335598468
Ref: Library<167>-Footnote-345598534
Node: Documentation<60>5598600
Ref: whatsnew/changelog id7885598712
Ref: 1e4e5598712
Ref: Documentation<60>-Footnote-15599663
Ref: Documentation<60>-Footnote-25599728
Ref: Documentation<60>-Footnote-35599793
Ref: Documentation<60>-Footnote-45599858
Ref: Documentation<60>-Footnote-55599923
Ref: Documentation<60>-Footnote-65599988
Ref: Documentation<60>-Footnote-75600052
Ref: Documentation<60>-Footnote-85600117
Node: Tests<58>5600182
Ref: whatsnew/changelog id7895600291
Ref: 1e4f5600291
Ref: Tests<58>-Footnote-15600434
Node: Build<66>5600499
Ref: whatsnew/changelog id7905600602
Ref: 1e505600602
Ref: Build<66>-Footnote-15600743
Node: Windows<58>5600808
Ref: whatsnew/changelog id7915600911
Ref: 1e515600911
Ref: Windows<58>-Footnote-15601647
Ref: Windows<58>-Footnote-25601712
Ref: Windows<58>-Footnote-35601777
Ref: Windows<58>-Footnote-45601842
Ref: Windows<58>-Footnote-55601907
Ref: Windows<58>-Footnote-65601972
Node: macOS<45>5602037
Ref: whatsnew/changelog id7925602139
Ref: 1e525602139
Ref: macOS<45>-Footnote-15602274
Node: IDLE<42>5602339
Ref: whatsnew/changelog id7935602445
Ref: 1e535602445
Ref: IDLE<42>-Footnote-15603290
Ref: IDLE<42>-Footnote-25603355
Ref: IDLE<42>-Footnote-35603420
Ref: IDLE<42>-Footnote-45603485
Ref: IDLE<42>-Footnote-55603550
Ref: IDLE<42>-Footnote-65603615
Node: Tools/Demos<40>5603680
Ref: whatsnew/changelog id7945603768
Ref: 1e545603768
Ref: Tools/Demos<40>-Footnote-15603987
Node: Python 3 7 0 beta 15604052
Ref: whatsnew/changelog python-3-7-0-beta-15604174
Ref: 1e555604174
Node: Core and Builtins<164>5604479
Ref: whatsnew/changelog id7955604578
Ref: 1e565604578
Ref: Core and Builtins<164>-Footnote-15608010
Ref: Core and Builtins<164>-Footnote-25608075
Ref: Core and Builtins<164>-Footnote-35608140
Ref: Core and Builtins<164>-Footnote-45608205
Ref: Core and Builtins<164>-Footnote-55608270
Ref: Core and Builtins<164>-Footnote-65608335
Ref: Core and Builtins<164>-Footnote-75608400
Ref: Core and Builtins<164>-Footnote-85608465
Ref: Core and Builtins<164>-Footnote-95608530
Ref: Core and Builtins<164>-Footnote-105608572
Ref: Core and Builtins<164>-Footnote-115608638
Ref: Core and Builtins<164>-Footnote-125608704
Ref: Core and Builtins<164>-Footnote-135608770
Ref: Core and Builtins<164>-Footnote-145608836
Ref: Core and Builtins<164>-Footnote-155608902
Ref: Core and Builtins<164>-Footnote-165608968
Ref: Core and Builtins<164>-Footnote-175609034
Ref: Core and Builtins<164>-Footnote-185609100
Ref: Core and Builtins<164>-Footnote-195609143
Ref: Core and Builtins<164>-Footnote-205609209
Ref: Core and Builtins<164>-Footnote-215609275
Ref: Core and Builtins<164>-Footnote-225609341
Ref: Core and Builtins<164>-Footnote-235609407
Node: Library<168>5609473
Ref: whatsnew/changelog id7965609598
Ref: 1e575609598
Ref: Library<168>-Footnote-15616975
Ref: Library<168>-Footnote-25617040
Ref: Library<168>-Footnote-35617105
Ref: Library<168>-Footnote-45617170
Ref: Library<168>-Footnote-55617235
Ref: Library<168>-Footnote-65617300
Ref: Library<168>-Footnote-75617365
Ref: Library<168>-Footnote-85617430
Ref: Library<168>-Footnote-95617495
Ref: Library<168>-Footnote-105617560
Ref: Library<168>-Footnote-115617626
Ref: Library<168>-Footnote-125617692
Ref: Library<168>-Footnote-135617758
Ref: Library<168>-Footnote-145617824
Ref: Library<168>-Footnote-155617890
Ref: Library<168>-Footnote-165617956
Ref: Library<168>-Footnote-175618022
Ref: Library<168>-Footnote-185618088
Ref: Library<168>-Footnote-195618131
Ref: Library<168>-Footnote-205618197
Ref: Library<168>-Footnote-215618263
Ref: Library<168>-Footnote-225618329
Ref: Library<168>-Footnote-235618395
Ref: Library<168>-Footnote-245618461
Ref: Library<168>-Footnote-255618527
Ref: Library<168>-Footnote-265618593
Ref: Library<168>-Footnote-275618659
Ref: Library<168>-Footnote-285618725
Ref: Library<168>-Footnote-295618791
Ref: Library<168>-Footnote-305618857
Ref: Library<168>-Footnote-315618923
Ref: Library<168>-Footnote-325618989
Ref: Library<168>-Footnote-335619055
Ref: Library<168>-Footnote-345619121
Ref: Library<168>-Footnote-355619187
Ref: Library<168>-Footnote-365619253
Ref: Library<168>-Footnote-375619319
Ref: Library<168>-Footnote-385619385
Ref: Library<168>-Footnote-395619451
Ref: Library<168>-Footnote-405619517
Ref: Library<168>-Footnote-415619583
Ref: Library<168>-Footnote-425619649
Ref: Library<168>-Footnote-435619715
Ref: Library<168>-Footnote-445619781
Ref: Library<168>-Footnote-455619847
Ref: Library<168>-Footnote-465619913
Ref: Library<168>-Footnote-475619979
Node: Documentation<61>5620045
Ref: whatsnew/changelog id7975620157
Ref: 1e585620157
Ref: Documentation<61>-Footnote-15620698
Ref: Documentation<61>-Footnote-25620763
Ref: Documentation<61>-Footnote-35620828
Node: Tests<59>5620893
Ref: whatsnew/changelog id7985621002
Ref: 1e595621002
Ref: Tests<59>-Footnote-15621912
Ref: Tests<59>-Footnote-25621977
Ref: Tests<59>-Footnote-35622042
Ref: Tests<59>-Footnote-45622107
Ref: Tests<59>-Footnote-55622172
Ref: Tests<59>-Footnote-65622237
Node: Build<67>5622302
Ref: whatsnew/changelog id7995622405
Ref: 1e5a5622405
Ref: Build<67>-Footnote-15623008
Ref: Build<67>-Footnote-25623073
Ref: Build<67>-Footnote-35623138
Ref: Build<67>-Footnote-45623203
Node: Windows<59>5623268
Ref: whatsnew/changelog id8005623371
Ref: 1e5b5623371
Ref: Windows<59>-Footnote-15623752
Ref: Windows<59>-Footnote-25623817
Ref: Windows<59>-Footnote-35623882
Node: macOS<46>5623947
Ref: whatsnew/changelog id8015624050
Ref: 1e5c5624050
Ref: macOS<46>-Footnote-15624572
Ref: macOS<46>-Footnote-25624637
Node: C API<59>5624702
Ref: whatsnew/changelog id8025624785
Ref: 1e5d5624785
Ref: C API<59>-Footnote-15625107
Ref: C API<59>-Footnote-25625172
Node: Python 3 7 0 alpha 45625237
Ref: whatsnew/changelog python-3-7-0-alpha-45625360
Ref: 1e5e5625360
Node: Core and Builtins<165>5625659
Ref: whatsnew/changelog id8035625759
Ref: 1e5f5625759
Ref: Core and Builtins<165>-Footnote-15629264
Ref: Core and Builtins<165>-Footnote-25629329
Ref: Core and Builtins<165>-Footnote-35629394
Ref: Core and Builtins<165>-Footnote-45629459
Ref: Core and Builtins<165>-Footnote-55629524
Ref: Core and Builtins<165>-Footnote-65629589
Ref: Core and Builtins<165>-Footnote-75629654
Ref: Core and Builtins<165>-Footnote-85629719
Ref: Core and Builtins<165>-Footnote-95629784
Ref: Core and Builtins<165>-Footnote-105629849
Ref: Core and Builtins<165>-Footnote-115629915
Ref: Core and Builtins<165>-Footnote-125629981
Ref: Core and Builtins<165>-Footnote-135630047
Ref: Core and Builtins<165>-Footnote-145630113
Ref: Core and Builtins<165>-Footnote-155630179
Ref: Core and Builtins<165>-Footnote-165630245
Ref: Core and Builtins<165>-Footnote-175630311
Ref: Core and Builtins<165>-Footnote-185630377
Ref: Core and Builtins<165>-Footnote-195630443
Ref: Core and Builtins<165>-Footnote-205630486
Ref: Core and Builtins<165>-Footnote-215630552
Ref: Core and Builtins<165>-Footnote-225630595
Ref: Core and Builtins<165>-Footnote-235630661
Ref: Core and Builtins<165>-Footnote-245630704
Ref: Core and Builtins<165>-Footnote-255630770
Ref: Core and Builtins<165>-Footnote-265630836
Ref: Core and Builtins<165>-Footnote-275630879
Node: Library<169>5630945
Ref: whatsnew/changelog id8045631071
Ref: 1e615631071
Ref: Library<169>-Footnote-15639084
Ref: Library<169>-Footnote-25639149
Ref: Library<169>-Footnote-35639214
Ref: Library<169>-Footnote-45639279
Ref: Library<169>-Footnote-55639344
Ref: Library<169>-Footnote-65639409
Ref: Library<169>-Footnote-75639474
Ref: Library<169>-Footnote-85639539
Ref: Library<169>-Footnote-95639604
Ref: Library<169>-Footnote-105639669
Ref: Library<169>-Footnote-115639735
Ref: Library<169>-Footnote-125639801
Ref: Library<169>-Footnote-135639867
Ref: Library<169>-Footnote-145639933
Ref: Library<169>-Footnote-155639999
Ref: Library<169>-Footnote-165640065
Ref: Library<169>-Footnote-175640131
Ref: Library<169>-Footnote-185640197
Ref: Library<169>-Footnote-195640263
Ref: Library<169>-Footnote-205640329
Ref: Library<169>-Footnote-215640395
Ref: Library<169>-Footnote-225640461
Ref: Library<169>-Footnote-235640527
Ref: Library<169>-Footnote-245640593
Ref: Library<169>-Footnote-255640659
Ref: Library<169>-Footnote-265640725
Ref: Library<169>-Footnote-275640791
Ref: Library<169>-Footnote-285640857
Ref: Library<169>-Footnote-295640923
Ref: Library<169>-Footnote-305640989
Ref: Library<169>-Footnote-315641055
Ref: Library<169>-Footnote-325641121
Ref: Library<169>-Footnote-335641187
Ref: Library<169>-Footnote-345641253
Ref: Library<169>-Footnote-355641319
Ref: Library<169>-Footnote-365641385
Ref: Library<169>-Footnote-375641451
Ref: Library<169>-Footnote-385641517
Ref: Library<169>-Footnote-395641583
Ref: Library<169>-Footnote-405641649
Ref: Library<169>-Footnote-415641715
Ref: Library<169>-Footnote-425641781
Ref: Library<169>-Footnote-435641847
Ref: Library<169>-Footnote-445641913
Ref: Library<169>-Footnote-455641979
Ref: Library<169>-Footnote-465642045
Ref: Library<169>-Footnote-475642111
Ref: Library<169>-Footnote-485642177
Ref: Library<169>-Footnote-495642243
Ref: Library<169>-Footnote-505642309
Ref: Library<169>-Footnote-515642375
Ref: Library<169>-Footnote-525642441
Ref: Library<169>-Footnote-535642507
Ref: Library<169>-Footnote-545642573
Node: Documentation<62>5642639
Ref: whatsnew/changelog id8055642752
Ref: 1e625642752
Ref: Documentation<62>-Footnote-15642922
Node: Tests<60>5642987
Ref: whatsnew/changelog id8065643099
Ref: 1e635643099
Ref: Tests<60>-Footnote-15643494
Ref: Tests<60>-Footnote-25643559
Node: Windows<60>5643624
Ref: whatsnew/changelog id8075643734
Ref: 1e645643734
Ref: Windows<60>-Footnote-15643933
Node: Tools/Demos<41>5643998
Ref: whatsnew/changelog id8085644108
Ref: 1e655644108
Ref: Tools/Demos<41>-Footnote-15644390
Node: C API<60>5644455
Ref: whatsnew/changelog id8095644545
Ref: 1e665644545
Ref: C API<60>-Footnote-15645189
Ref: C API<60>-Footnote-25645254
Ref: C API<60>-Footnote-35645319
Ref: C API<60>-Footnote-45645384
Node: Python 3 7 0 alpha 35645449
Ref: whatsnew/changelog python-3-7-0-alpha-35645573
Ref: 1e675645573
Node: Core and Builtins<166>5645930
Ref: whatsnew/changelog id8105646030
Ref: 1e685646030
Ref: Core and Builtins<166>-Footnote-15651161
Ref: Core and Builtins<166>-Footnote-25651226
Ref: Core and Builtins<166>-Footnote-35651291
Ref: Core and Builtins<166>-Footnote-45651356
Ref: Core and Builtins<166>-Footnote-55651421
Ref: Core and Builtins<166>-Footnote-65651486
Ref: Core and Builtins<166>-Footnote-75651551
Ref: Core and Builtins<166>-Footnote-85651616
Ref: Core and Builtins<166>-Footnote-95651681
Ref: Core and Builtins<166>-Footnote-105651746
Ref: Core and Builtins<166>-Footnote-115651812
Ref: Core and Builtins<166>-Footnote-125651878
Ref: Core and Builtins<166>-Footnote-135651944
Ref: Core and Builtins<166>-Footnote-145652010
Ref: Core and Builtins<166>-Footnote-155652076
Ref: Core and Builtins<166>-Footnote-165652142
Ref: Core and Builtins<166>-Footnote-175652208
Ref: Core and Builtins<166>-Footnote-185652274
Ref: Core and Builtins<166>-Footnote-195652340
Ref: Core and Builtins<166>-Footnote-205652406
Ref: Core and Builtins<166>-Footnote-215652472
Ref: Core and Builtins<166>-Footnote-225652538
Node: Library<170>5652604
Ref: whatsnew/changelog id8115652730
Ref: 1e695652730
Ref: Library<170>-Footnote-15668778
Ref: Library<170>-Footnote-25668843
Ref: Library<170>-Footnote-35668908
Ref: Library<170>-Footnote-45668973
Ref: Library<170>-Footnote-55669038
Ref: Library<170>-Footnote-65669103
Ref: Library<170>-Footnote-75669168
Ref: Library<170>-Footnote-85669233
Ref: Library<170>-Footnote-95669298
Ref: Library<170>-Footnote-105669363
Ref: Library<170>-Footnote-115669429
Ref: Library<170>-Footnote-125669495
Ref: Library<170>-Footnote-135669561
Ref: Library<170>-Footnote-145669627
Ref: Library<170>-Footnote-155669693
Ref: Library<170>-Footnote-165669759
Ref: Library<170>-Footnote-175669825
Ref: Library<170>-Footnote-185669891
Ref: Library<170>-Footnote-195669957
Ref: Library<170>-Footnote-205670023
Ref: Library<170>-Footnote-215670089
Ref: Library<170>-Footnote-225670155
Ref: Library<170>-Footnote-235670221
Ref: Library<170>-Footnote-245670287
Ref: Library<170>-Footnote-255670353
Ref: Library<170>-Footnote-265670421
Ref: Library<170>-Footnote-275670487
Ref: Library<170>-Footnote-285670553
Ref: Library<170>-Footnote-295670619
Ref: Library<170>-Footnote-305670685
Ref: Library<170>-Footnote-315670751
Ref: Library<170>-Footnote-325670817
Ref: Library<170>-Footnote-335670860
Ref: Library<170>-Footnote-345670926
Ref: Library<170>-Footnote-355670992
Ref: Library<170>-Footnote-365671058
Ref: Library<170>-Footnote-375671124
Ref: Library<170>-Footnote-385671190
Ref: Library<170>-Footnote-395671256
Ref: Library<170>-Footnote-405671322
Ref: Library<170>-Footnote-415671388
Ref: Library<170>-Footnote-425671454
Ref: Library<170>-Footnote-435671520
Ref: Library<170>-Footnote-445671586
Ref: Library<170>-Footnote-455671652
Ref: Library<170>-Footnote-465671718
Ref: Library<170>-Footnote-475671783
Ref: Library<170>-Footnote-485671849
Ref: Library<170>-Footnote-495671915
Ref: Library<170>-Footnote-505671981
Ref: Library<170>-Footnote-515672047
Ref: Library<170>-Footnote-525672113
Ref: Library<170>-Footnote-535672179
Ref: Library<170>-Footnote-545672245
Ref: Library<170>-Footnote-555672311
Ref: Library<170>-Footnote-565672377
Ref: Library<170>-Footnote-575672443
Ref: Library<170>-Footnote-585672509
Ref: Library<170>-Footnote-595672575
Ref: Library<170>-Footnote-605672641
Ref: Library<170>-Footnote-615672707
Ref: Library<170>-Footnote-625672773
Ref: Library<170>-Footnote-635672816
Ref: Library<170>-Footnote-645672882
Ref: Library<170>-Footnote-655672948
Ref: Library<170>-Footnote-665673014
Ref: Library<170>-Footnote-675673080
Ref: Library<170>-Footnote-685673146
Ref: Library<170>-Footnote-695673212
Ref: Library<170>-Footnote-705673278
Ref: Library<170>-Footnote-715673344
Ref: Library<170>-Footnote-725673410
Ref: Library<170>-Footnote-735673476
Ref: Library<170>-Footnote-745673542
Ref: Library<170>-Footnote-755673608
Ref: Library<170>-Footnote-765673674
Ref: Library<170>-Footnote-775673740
Ref: Library<170>-Footnote-785673806
Ref: Library<170>-Footnote-795673872
Ref: Library<170>-Footnote-805673938
Ref: Library<170>-Footnote-815674004
Ref: Library<170>-Footnote-825674070
Ref: Library<170>-Footnote-835674113
Ref: Library<170>-Footnote-845674179
Ref: Library<170>-Footnote-855674245
Ref: Library<170>-Footnote-865674311
Ref: Library<170>-Footnote-875674377
Ref: Library<170>-Footnote-885674443
Ref: Library<170>-Footnote-895674509
Ref: Library<170>-Footnote-905674575
Ref: Library<170>-Footnote-915674641
Ref: Library<170>-Footnote-925674707
Ref: Library<170>-Footnote-935674773
Ref: Library<170>-Footnote-945674839
Ref: Library<170>-Footnote-955674905
Ref: Library<170>-Footnote-965674971
Ref: Library<170>-Footnote-975675037
Ref: Library<170>-Footnote-985675103
Node: Documentation<63>5675169
Ref: whatsnew/changelog id8125675282
Ref: 1e6e5675282
Ref: Documentation<63>-Footnote-15675465
Node: Tests<61>5675530
Ref: whatsnew/changelog id8135675640
Ref: 1e6f5675640
Ref: Tests<61>-Footnote-15676850
Ref: Tests<61>-Footnote-25676915
Ref: Tests<61>-Footnote-35676980
Ref: Tests<61>-Footnote-45677045
Ref: Tests<61>-Footnote-55677110
Ref: Tests<61>-Footnote-65677175
Ref: Tests<61>-Footnote-75677240
Node: Build<68>5677305
Ref: whatsnew/changelog id8145677409
Ref: 1e705677409
Ref: Build<68>-Footnote-15678623
Ref: Build<68>-Footnote-25678688
Ref: Build<68>-Footnote-35678753
Ref: Build<68>-Footnote-45678818
Ref: Build<68>-Footnote-55678883
Ref: Build<68>-Footnote-65678948
Ref: Build<68>-Footnote-75679013
Ref: Build<68>-Footnote-85679078
Ref: Build<68>-Footnote-95679143
Ref: Build<68>-Footnote-105679208
Ref: Build<68>-Footnote-115679274
Ref: Build<68>-Footnote-125679340
Node: Windows<61>5679406
Ref: whatsnew/changelog id8155679510
Ref: 1e715679510
Ref: Windows<61>-Footnote-15680043
Ref: Windows<61>-Footnote-25680107
Ref: Windows<61>-Footnote-35680172
Ref: Windows<61>-Footnote-45680237
Node: macOS<47>5680302
Ref: whatsnew/changelog id8165680405
Ref: 1e725680405
Ref: macOS<47>-Footnote-15680539
Node: IDLE<43>5680604
Ref: whatsnew/changelog id8175680711
Ref: 1e735680711
Ref: IDLE<43>-Footnote-15682804
Ref: IDLE<43>-Footnote-25682869
Ref: IDLE<43>-Footnote-35682934
Ref: IDLE<43>-Footnote-45682999
Ref: IDLE<43>-Footnote-55683064
Ref: IDLE<43>-Footnote-65683129
Ref: IDLE<43>-Footnote-75683194
Ref: IDLE<43>-Footnote-85683259
Node: Tools/Demos<42>5683324
Ref: whatsnew/changelog id8185683431
Ref: 1e745683431
Ref: Tools/Demos<42>-Footnote-15683963
Ref: Tools/Demos<42>-Footnote-25684028
Node: C API<61>5684093
Ref: whatsnew/changelog id8195684183
Ref: 1e755684183
Ref: C API<61>-Footnote-15685311
Ref: C API<61>-Footnote-25685376
Ref: C API<61>-Footnote-35685441
Ref: C API<61>-Footnote-45685506
Ref: C API<61>-Footnote-55685571
Ref: C API<61>-Footnote-65685636
Node: Python 3 7 0 alpha 25685701
Ref: whatsnew/changelog python-3-7-0-alpha-25685825
Ref: 1e765685825
Node: Core and Builtins<167>5686086
Ref: whatsnew/changelog id8205686186
Ref: 1e775686186
Ref: Core and Builtins<167>-Footnote-15690375
Ref: Core and Builtins<167>-Footnote-25690440
Ref: Core and Builtins<167>-Footnote-35690505
Ref: Core and Builtins<167>-Footnote-45690570
Ref: Core and Builtins<167>-Footnote-55690635
Ref: Core and Builtins<167>-Footnote-65690700
Ref: Core and Builtins<167>-Footnote-75690765
Ref: Core and Builtins<167>-Footnote-85690830
Ref: Core and Builtins<167>-Footnote-95690895
Ref: Core and Builtins<167>-Footnote-105690960
Ref: Core and Builtins<167>-Footnote-115691026
Ref: Core and Builtins<167>-Footnote-125691092
Ref: Core and Builtins<167>-Footnote-135691158
Ref: Core and Builtins<167>-Footnote-145691224
Ref: Core and Builtins<167>-Footnote-155691290
Ref: Core and Builtins<167>-Footnote-165691356
Ref: Core and Builtins<167>-Footnote-175691422
Ref: Core and Builtins<167>-Footnote-185691488
Ref: Core and Builtins<167>-Footnote-195691554
Ref: Core and Builtins<167>-Footnote-205691620
Ref: Core and Builtins<167>-Footnote-215691663
Ref: Core and Builtins<167>-Footnote-225691729
Ref: Core and Builtins<167>-Footnote-235691795
Ref: Core and Builtins<167>-Footnote-245691861
Ref: Core and Builtins<167>-Footnote-255691927
Ref: Core and Builtins<167>-Footnote-265691993
Ref: Core and Builtins<167>-Footnote-275692059
Node: Library<171>5692102
Ref: whatsnew/changelog id8215692228
Ref: 1e785692228
Ref: Library<171>-Footnote-15696289
Ref: Library<171>-Footnote-25696354
Ref: Library<171>-Footnote-35696419
Ref: Library<171>-Footnote-45696484
Ref: Library<171>-Footnote-55696549
Ref: Library<171>-Footnote-65696614
Ref: Library<171>-Footnote-75696679
Ref: Library<171>-Footnote-85696744
Ref: Library<171>-Footnote-95696809
Ref: Library<171>-Footnote-105696874
Ref: Library<171>-Footnote-115696940
Ref: Library<171>-Footnote-125697006
Ref: Library<171>-Footnote-135697072
Ref: Library<171>-Footnote-145697138
Ref: Library<171>-Footnote-155697204
Ref: Library<171>-Footnote-165697270
Ref: Library<171>-Footnote-175697336
Ref: Library<171>-Footnote-185697402
Ref: Library<171>-Footnote-195697468
Ref: Library<171>-Footnote-205697534
Ref: Library<171>-Footnote-215697600
Ref: Library<171>-Footnote-225697666
Ref: Library<171>-Footnote-235697732
Ref: Library<171>-Footnote-245697798
Ref: Library<171>-Footnote-255697864
Ref: Library<171>-Footnote-265697930
Node: Documentation<64>5697996
Ref: whatsnew/changelog id8225698109
Ref: 1e795698109
Ref: Documentation<64>-Footnote-15698500
Ref: Documentation<64>-Footnote-25698565
Node: Build<69>5698630
Ref: whatsnew/changelog id8235698739
Ref: 1e7a5698739
Ref: Build<69>-Footnote-15699366
Ref: Build<69>-Footnote-25699431
Ref: Build<69>-Footnote-35699496
Ref: Build<69>-Footnote-45699561
Ref: Build<69>-Footnote-55699626
Ref: Build<69>-Footnote-65699691
Node: IDLE<44>5699756
Ref: whatsnew/changelog id8245699857
Ref: 1e7b5699857
Ref: IDLE<44>-Footnote-15701163
Ref: IDLE<44>-Footnote-25701228
Ref: IDLE<44>-Footnote-35701293
Ref: IDLE<44>-Footnote-45701358
Ref: IDLE<44>-Footnote-55701423
Ref: IDLE<44>-Footnote-65701488
Node: C API<62>5701555
Ref: whatsnew/changelog id8255701638
Ref: 1e7c5701638
Ref: C API<62>-Footnote-15702362
Ref: C API<62>-Footnote-25702427
Ref: C API<62>-Footnote-35702492
Ref: C API<62>-Footnote-45702557
Node: Python 3 7 0 alpha 15702599
Ref: whatsnew/changelog python-3-7-0-alpha-15702721
Ref: 1e7d5702721
Node: Security<49>5703084
Ref: whatsnew/changelog id8265703184
Ref: 1e7e5703184
Ref: Security<49>-Footnote-15704838
Ref: Security<49>-Footnote-25704903
Ref: Security<49>-Footnote-35704968
Ref: Security<49>-Footnote-45705033
Ref: Security<49>-Footnote-55705098
Ref: Security<49>-Footnote-65705163
Ref: Security<49>-Footnote-75705218
Ref: Security<49>-Footnote-85705273
Ref: Security<49>-Footnote-95705328
Ref: Security<49>-Footnote-105705383
Ref: Security<49>-Footnote-115705439
Ref: Security<49>-Footnote-125705495
Ref: Security<49>-Footnote-135705561
Ref: Security<49>-Footnote-145705627
Ref: Security<49>-Footnote-155705683
Node: Core and Builtins<168>5705739
Ref: whatsnew/changelog id8275705860
Ref: 1e7f5705860
Ref: Core and Builtins<168>-Footnote-15726746
Ref: Core and Builtins<168>-Footnote-25726811
Ref: Core and Builtins<168>-Footnote-35726876
Ref: Core and Builtins<168>-Footnote-45726941
Ref: Core and Builtins<168>-Footnote-55727006
Ref: Core and Builtins<168>-Footnote-65727071
Ref: Core and Builtins<168>-Footnote-75727136
Ref: Core and Builtins<168>-Footnote-85727201
Ref: Core and Builtins<168>-Footnote-95727266
Ref: Core and Builtins<168>-Footnote-105727331
Ref: Core and Builtins<168>-Footnote-115727397
Ref: Core and Builtins<168>-Footnote-125727463
Ref: Core and Builtins<168>-Footnote-135727529
Ref: Core and Builtins<168>-Footnote-145727595
Ref: Core and Builtins<168>-Footnote-155727661
Ref: Core and Builtins<168>-Footnote-165727727
Ref: Core and Builtins<168>-Footnote-175727793
Ref: Core and Builtins<168>-Footnote-185727859
Ref: Core and Builtins<168>-Footnote-195727925
Ref: Core and Builtins<168>-Footnote-205727991
Ref: Core and Builtins<168>-Footnote-215728057
Ref: Core and Builtins<168>-Footnote-225728123
Ref: Core and Builtins<168>-Footnote-235728189
Ref: Core and Builtins<168>-Footnote-245728255
Ref: Core and Builtins<168>-Footnote-255728321
Ref: Core and Builtins<168>-Footnote-265728387
Ref: Core and Builtins<168>-Footnote-275728453
Ref: Core and Builtins<168>-Footnote-285728519
Ref: Core and Builtins<168>-Footnote-295728585
Ref: Core and Builtins<168>-Footnote-305728651
Ref: Core and Builtins<168>-Footnote-315728717
Ref: Core and Builtins<168>-Footnote-325728783
Ref: Core and Builtins<168>-Footnote-335728849
Ref: Core and Builtins<168>-Footnote-345728915
Ref: Core and Builtins<168>-Footnote-355728981
Ref: Core and Builtins<168>-Footnote-365729024
Ref: Core and Builtins<168>-Footnote-375729090
Ref: Core and Builtins<168>-Footnote-385729156
Ref: Core and Builtins<168>-Footnote-395729222
Ref: Core and Builtins<168>-Footnote-405729288
Ref: Core and Builtins<168>-Footnote-415729354
Ref: Core and Builtins<168>-Footnote-425729420
Ref: Core and Builtins<168>-Footnote-435729486
Ref: Core and Builtins<168>-Footnote-445729552
Ref: Core and Builtins<168>-Footnote-455729618
Ref: Core and Builtins<168>-Footnote-465729684
Ref: Core and Builtins<168>-Footnote-475729750
Ref: Core and Builtins<168>-Footnote-485729816
Ref: Core and Builtins<168>-Footnote-495729882
Ref: Core and Builtins<168>-Footnote-505729948
Ref: Core and Builtins<168>-Footnote-515730014
Ref: Core and Builtins<168>-Footnote-525730080
Ref: Core and Builtins<168>-Footnote-535730146
Ref: Core and Builtins<168>-Footnote-545730212
Ref: Core and Builtins<168>-Footnote-555730278
Ref: Core and Builtins<168>-Footnote-565730344
Ref: Core and Builtins<168>-Footnote-575730410
Ref: Core and Builtins<168>-Footnote-585730476
Ref: Core and Builtins<168>-Footnote-595730542
Ref: Core and Builtins<168>-Footnote-605730608
Ref: Core and Builtins<168>-Footnote-615730674
Ref: Core and Builtins<168>-Footnote-625730740
Ref: Core and Builtins<168>-Footnote-635730806
Ref: Core and Builtins<168>-Footnote-645730872
Ref: Core and Builtins<168>-Footnote-655730938
Ref: Core and Builtins<168>-Footnote-665731004
Ref: Core and Builtins<168>-Footnote-675731070
Ref: Core and Builtins<168>-Footnote-685731136
Ref: Core and Builtins<168>-Footnote-695731202
Ref: Core and Builtins<168>-Footnote-705731268
Ref: Core and Builtins<168>-Footnote-715731334
Ref: Core and Builtins<168>-Footnote-725731400
Ref: Core and Builtins<168>-Footnote-735731466
Ref: Core and Builtins<168>-Footnote-745731532
Ref: Core and Builtins<168>-Footnote-755731598
Ref: Core and Builtins<168>-Footnote-765731664
Ref: Core and Builtins<168>-Footnote-775731730
Ref: Core and Builtins<168>-Footnote-785731796
Ref: Core and Builtins<168>-Footnote-795731862
Ref: Core and Builtins<168>-Footnote-805731928
Ref: Core and Builtins<168>-Footnote-815731994
Ref: Core and Builtins<168>-Footnote-825732060
Ref: Core and Builtins<168>-Footnote-835732126
Ref: Core and Builtins<168>-Footnote-845732192
Ref: Core and Builtins<168>-Footnote-855732258
Ref: Core and Builtins<168>-Footnote-865732324
Ref: Core and Builtins<168>-Footnote-875732390
Ref: Core and Builtins<168>-Footnote-885732456
Ref: Core and Builtins<168>-Footnote-895732522
Ref: Core and Builtins<168>-Footnote-905732588
Ref: Core and Builtins<168>-Footnote-915732631
Ref: Core and Builtins<168>-Footnote-925732697
Ref: Core and Builtins<168>-Footnote-935732763
Ref: Core and Builtins<168>-Footnote-945732829
Ref: Core and Builtins<168>-Footnote-955732895
Ref: Core and Builtins<168>-Footnote-965732961
Ref: Core and Builtins<168>-Footnote-975733027
Ref: Core and Builtins<168>-Footnote-985733093
Ref: Core and Builtins<168>-Footnote-995733159
Ref: Core and Builtins<168>-Footnote-1005733225
Ref: Core and Builtins<168>-Footnote-1015733292
Ref: Core and Builtins<168>-Footnote-1025733359
Ref: Core and Builtins<168>-Footnote-1035733426
Ref: Core and Builtins<168>-Footnote-1045733493
Ref: Core and Builtins<168>-Footnote-1055733560
Ref: Core and Builtins<168>-Footnote-1065733627
Ref: Core and Builtins<168>-Footnote-1075733694
Ref: Core and Builtins<168>-Footnote-1085733761
Ref: Core and Builtins<168>-Footnote-1095733828
Ref: Core and Builtins<168>-Footnote-1105733895
Ref: Core and Builtins<168>-Footnote-1115733962
Ref: Core and Builtins<168>-Footnote-1125734029
Ref: Core and Builtins<168>-Footnote-1135734096
Ref: Core and Builtins<168>-Footnote-1145734163
Ref: Core and Builtins<168>-Footnote-1155734230
Ref: Core and Builtins<168>-Footnote-1165734297
Ref: Core and Builtins<168>-Footnote-1175734364
Ref: Core and Builtins<168>-Footnote-1185734431
Ref: Core and Builtins<168>-Footnote-1195734498
Ref: Core and Builtins<168>-Footnote-1205734565
Ref: Core and Builtins<168>-Footnote-1215734632
Ref: Core and Builtins<168>-Footnote-1225734699
Ref: Core and Builtins<168>-Footnote-1235734766
Ref: Core and Builtins<168>-Footnote-1245734833
Ref: Core and Builtins<168>-Footnote-1255734900
Ref: Core and Builtins<168>-Footnote-1265734967
Ref: Core and Builtins<168>-Footnote-1275735034
Ref: Core and Builtins<168>-Footnote-1285735101
Ref: Core and Builtins<168>-Footnote-1295735168
Ref: Core and Builtins<168>-Footnote-1305735235
Ref: Core and Builtins<168>-Footnote-1315735302
Ref: Core and Builtins<168>-Footnote-1325735369
Ref: Core and Builtins<168>-Footnote-1335735436
Ref: Core and Builtins<168>-Footnote-1345735503
Ref: Core and Builtins<168>-Footnote-1355735570
Ref: Core and Builtins<168>-Footnote-1365735637
Ref: Core and Builtins<168>-Footnote-1375735704
Ref: Core and Builtins<168>-Footnote-1385735771
Ref: Core and Builtins<168>-Footnote-1395735838
Ref: Core and Builtins<168>-Footnote-1405735905
Ref: Core and Builtins<168>-Footnote-1415735972
Ref: Core and Builtins<168>-Footnote-1425736039
Ref: Core and Builtins<168>-Footnote-1435736106
Ref: Core and Builtins<168>-Footnote-1445736173
Ref: Core and Builtins<168>-Footnote-1455736240
Ref: Core and Builtins<168>-Footnote-1465736307
Ref: Core and Builtins<168>-Footnote-1475736374
Ref: Core and Builtins<168>-Footnote-1485736441
Node: Library<172>5736508
Ref: whatsnew/changelog id8285736634
Ref: 1e805736634
Ref: Library<172>-Footnote-15783255
Ref: Library<172>-Footnote-25783320
Ref: Library<172>-Footnote-35783385
Ref: Library<172>-Footnote-45783450
Ref: Library<172>-Footnote-55783515
Ref: Library<172>-Footnote-65783580
Ref: Library<172>-Footnote-75783645
Ref: Library<172>-Footnote-85783710
Ref: Library<172>-Footnote-95783775
Ref: Library<172>-Footnote-105783840
Ref: Library<172>-Footnote-115783906
Ref: Library<172>-Footnote-125783972
Ref: Library<172>-Footnote-135784038
Ref: Library<172>-Footnote-145784104
Ref: Library<172>-Footnote-155784170
Ref: Library<172>-Footnote-165784236
Ref: Library<172>-Footnote-175784302
Ref: Library<172>-Footnote-185784368
Ref: Library<172>-Footnote-195784434
Ref: Library<172>-Footnote-205784500
Ref: Library<172>-Footnote-215784566
Ref: Library<172>-Footnote-225784634
Ref: Library<172>-Footnote-235784700
Ref: Library<172>-Footnote-245784766
Ref: Library<172>-Footnote-255784832
Ref: Library<172>-Footnote-265784898
Ref: Library<172>-Footnote-275784941
Ref: Library<172>-Footnote-285785007
Ref: Library<172>-Footnote-295785073
Ref: Library<172>-Footnote-305785139
Ref: Library<172>-Footnote-315785205
Ref: Library<172>-Footnote-325785271
Ref: Library<172>-Footnote-335785337
Ref: Library<172>-Footnote-345785403
Ref: Library<172>-Footnote-355785468
Ref: Library<172>-Footnote-365785534
Ref: Library<172>-Footnote-375785600
Ref: Library<172>-Footnote-385785666
Ref: Library<172>-Footnote-395785732
Ref: Library<172>-Footnote-405785797
Ref: Library<172>-Footnote-415785863
Ref: Library<172>-Footnote-425785929
Ref: Library<172>-Footnote-435785995
Ref: Library<172>-Footnote-445786061
Ref: Library<172>-Footnote-455786127
Ref: Library<172>-Footnote-465786193
Ref: Library<172>-Footnote-475786259
Ref: Library<172>-Footnote-485786325
Ref: Library<172>-Footnote-495786391
Ref: Library<172>-Footnote-505786457
Ref: Library<172>-Footnote-515786523
Ref: Library<172>-Footnote-525786589
Ref: Library<172>-Footnote-535786654
Ref: Library<172>-Footnote-545786720
Ref: Library<172>-Footnote-555786786
Ref: Library<172>-Footnote-565786852
Ref: Library<172>-Footnote-575786918
Ref: Library<172>-Footnote-585786984
Ref: Library<172>-Footnote-595787050
Ref: Library<172>-Footnote-605787116
Ref: Library<172>-Footnote-615787182
Ref: Library<172>-Footnote-625787248
Ref: Library<172>-Footnote-635787314
Ref: Library<172>-Footnote-645787380
Ref: Library<172>-Footnote-655787446
Ref: Library<172>-Footnote-665787512
Ref: Library<172>-Footnote-675787578
Ref: Library<172>-Footnote-685787644
Ref: Library<172>-Footnote-695787710
Ref: Library<172>-Footnote-705787776
Ref: Library<172>-Footnote-715787842
Ref: Library<172>-Footnote-725787908
Ref: Library<172>-Footnote-735787973
Ref: Library<172>-Footnote-745788039
Ref: Library<172>-Footnote-755788105
Ref: Library<172>-Footnote-765788171
Ref: Library<172>-Footnote-775788237
Ref: Library<172>-Footnote-785788303
Ref: Library<172>-Footnote-795788369
Ref: Library<172>-Footnote-805788435
Ref: Library<172>-Footnote-815788501
Ref: Library<172>-Footnote-825788567
Ref: Library<172>-Footnote-835788633
Ref: Library<172>-Footnote-845788699
Ref: Library<172>-Footnote-855788765
Ref: Library<172>-Footnote-865788831
Ref: Library<172>-Footnote-875788897
Ref: Library<172>-Footnote-885788963
Ref: Library<172>-Footnote-895789029
Ref: Library<172>-Footnote-905789095
Ref: Library<172>-Footnote-915789161
Ref: Library<172>-Footnote-925789227
Ref: Library<172>-Footnote-935789293
Ref: Library<172>-Footnote-945789359
Ref: Library<172>-Footnote-955789425
Ref: Library<172>-Footnote-965789491
Ref: Library<172>-Footnote-975789557
Ref: Library<172>-Footnote-985789623
Ref: Library<172>-Footnote-995789689
Ref: Library<172>-Footnote-1005789755
Ref: Library<172>-Footnote-1015789822
Ref: Library<172>-Footnote-1025789889
Ref: Library<172>-Footnote-1035789956
Ref: Library<172>-Footnote-1045790023
Ref: Library<172>-Footnote-1055790090
Ref: Library<172>-Footnote-1065790157
Ref: Library<172>-Footnote-1075790224
Ref: Library<172>-Footnote-1085790291
Ref: Library<172>-Footnote-1095790358
Ref: Library<172>-Footnote-1105790425
Ref: Library<172>-Footnote-1115790492
Ref: Library<172>-Footnote-1125790559
Ref: Library<172>-Footnote-1135790626
Ref: Library<172>-Footnote-1145790693
Ref: Library<172>-Footnote-1155790760
Ref: Library<172>-Footnote-1165790827
Ref: Library<172>-Footnote-1175790893
Ref: Library<172>-Footnote-1185790960
Ref: Library<172>-Footnote-1195791027
Ref: Library<172>-Footnote-1205791094
Ref: Library<172>-Footnote-1215791161
Ref: Library<172>-Footnote-1225791228
Ref: Library<172>-Footnote-1235791295
Ref: Library<172>-Footnote-1245791362
Ref: Library<172>-Footnote-1255791429
Ref: Library<172>-Footnote-1265791496
Ref: Library<172>-Footnote-1275791563
Ref: Library<172>-Footnote-1285791630
Ref: Library<172>-Footnote-1295791697
Ref: Library<172>-Footnote-1305791764
Ref: Library<172>-Footnote-1315791831
Ref: Library<172>-Footnote-1325791898
Ref: Library<172>-Footnote-1335791965
Ref: Library<172>-Footnote-1345792032
Ref: Library<172>-Footnote-1355792099
Ref: Library<172>-Footnote-1365792166
Ref: Library<172>-Footnote-1375792233
Ref: Library<172>-Footnote-1385792300
Ref: Library<172>-Footnote-1395792367
Ref: Library<172>-Footnote-1405792434
Ref: Library<172>-Footnote-1415792501
Ref: Library<172>-Footnote-1425792568
Ref: Library<172>-Footnote-1435792635
Ref: Library<172>-Footnote-1445792702
Ref: Library<172>-Footnote-1455792769
Ref: Library<172>-Footnote-1465792836
Ref: Library<172>-Footnote-1475792902
Ref: Library<172>-Footnote-1485792969
Ref: Library<172>-Footnote-1495793036
Ref: Library<172>-Footnote-1505793103
Ref: Library<172>-Footnote-1515793170
Ref: Library<172>-Footnote-1525793237
Ref: Library<172>-Footnote-1535793304
Ref: Library<172>-Footnote-1545793371
Ref: Library<172>-Footnote-1555793438
Ref: Library<172>-Footnote-1565793505
Ref: Library<172>-Footnote-1575793572
Ref: Library<172>-Footnote-1585793639
Ref: Library<172>-Footnote-1595793706
Ref: Library<172>-Footnote-1605793773
Ref: Library<172>-Footnote-1615793840
Ref: Library<172>-Footnote-1625793907
Ref: Library<172>-Footnote-1635793974
Ref: Library<172>-Footnote-1645794041
Ref: Library<172>-Footnote-1655794108
Ref: Library<172>-Footnote-1665794175
Ref: Library<172>-Footnote-1675794242
Ref: Library<172>-Footnote-1685794309
Ref: Library<172>-Footnote-1695794376
Ref: Library<172>-Footnote-1705794442
Ref: Library<172>-Footnote-1715794509
Ref: Library<172>-Footnote-1725794576
Ref: Library<172>-Footnote-1735794643
Ref: Library<172>-Footnote-1745794710
Ref: Library<172>-Footnote-1755794777
Ref: Library<172>-Footnote-1765794844
Ref: Library<172>-Footnote-1775794911
Ref: Library<172>-Footnote-1785794978
Ref: Library<172>-Footnote-1795795045
Ref: Library<172>-Footnote-1805795112
Ref: Library<172>-Footnote-1815795178
Ref: Library<172>-Footnote-1825795245
Ref: Library<172>-Footnote-1835795312
Ref: Library<172>-Footnote-1845795379
Ref: Library<172>-Footnote-1855795446
Ref: Library<172>-Footnote-1865795513
Ref: Library<172>-Footnote-1875795579
Ref: Library<172>-Footnote-1885795646
Ref: Library<172>-Footnote-1895795713
Ref: Library<172>-Footnote-1905795780
Ref: Library<172>-Footnote-1915795847
Ref: Library<172>-Footnote-1925795914
Ref: Library<172>-Footnote-1935795981
Ref: Library<172>-Footnote-1945796048
Ref: Library<172>-Footnote-1955796115
Ref: Library<172>-Footnote-1965796182
Ref: Library<172>-Footnote-1975796249
Ref: Library<172>-Footnote-1985796316
Ref: Library<172>-Footnote-1995796383
Ref: Library<172>-Footnote-2005796450
Ref: Library<172>-Footnote-2015796517
Ref: Library<172>-Footnote-2025796584
Ref: Library<172>-Footnote-2035796651
Ref: Library<172>-Footnote-2045796718
Ref: Library<172>-Footnote-2055796785
Ref: Library<172>-Footnote-2065796852
Ref: Library<172>-Footnote-2075796919
Ref: Library<172>-Footnote-2085796986
Ref: Library<172>-Footnote-2095797053
Ref: Library<172>-Footnote-2105797120
Ref: Library<172>-Footnote-2115797187
Ref: Library<172>-Footnote-2125797254
Ref: Library<172>-Footnote-2135797321
Ref: Library<172>-Footnote-2145797388
Ref: Library<172>-Footnote-2155797455
Ref: Library<172>-Footnote-2165797522
Ref: Library<172>-Footnote-2175797589
Ref: Library<172>-Footnote-2185797656
Ref: Library<172>-Footnote-2195797723
Ref: Library<172>-Footnote-2205797790
Ref: Library<172>-Footnote-2215797857
Ref: Library<172>-Footnote-2225797924
Ref: Library<172>-Footnote-2235797991
Ref: Library<172>-Footnote-2245798058
Ref: Library<172>-Footnote-2255798124
Ref: Library<172>-Footnote-2265798191
Ref: Library<172>-Footnote-2275798258
Ref: Library<172>-Footnote-2285798325
Ref: Library<172>-Footnote-2295798392
Ref: Library<172>-Footnote-2305798459
Ref: Library<172>-Footnote-2315798526
Ref: Library<172>-Footnote-2325798593
Ref: Library<172>-Footnote-2335798660
Ref: Library<172>-Footnote-2345798727
Ref: Library<172>-Footnote-2355798794
Ref: Library<172>-Footnote-2365798861
Ref: Library<172>-Footnote-2375798928
Ref: Library<172>-Footnote-2385798995
Ref: Library<172>-Footnote-2395799062
Ref: Library<172>-Footnote-2405799129
Ref: Library<172>-Footnote-2415799196
Ref: Library<172>-Footnote-2425799263
Ref: Library<172>-Footnote-2435799330
Ref: Library<172>-Footnote-2445799397
Ref: Library<172>-Footnote-2455799464
Ref: Library<172>-Footnote-2465799531
Ref: Library<172>-Footnote-2475799598
Ref: Library<172>-Footnote-2485799665
Ref: Library<172>-Footnote-2495799732
Ref: Library<172>-Footnote-2505799799
Ref: Library<172>-Footnote-2515799866
Ref: Library<172>-Footnote-2525799933
Ref: Library<172>-Footnote-2535800000
Ref: Library<172>-Footnote-2545800067
Ref: Library<172>-Footnote-2555800134
Ref: Library<172>-Footnote-2565800201
Ref: Library<172>-Footnote-2575800268
Ref: Library<172>-Footnote-2585800335
Ref: Library<172>-Footnote-2595800402
Ref: Library<172>-Footnote-2605800469
Ref: Library<172>-Footnote-2615800536
Ref: Library<172>-Footnote-2625800603
Ref: Library<172>-Footnote-2635800670
Ref: Library<172>-Footnote-2645800737
Ref: Library<172>-Footnote-2655800804
Ref: Library<172>-Footnote-2665800871
Ref: Library<172>-Footnote-2675800938
Ref: Library<172>-Footnote-2685801005
Ref: Library<172>-Footnote-2695801072
Ref: Library<172>-Footnote-2705801139
Ref: Library<172>-Footnote-2715801206
Ref: Library<172>-Footnote-2725801273
Ref: Library<172>-Footnote-2735801329
Ref: Library<172>-Footnote-2745801396
Ref: Library<172>-Footnote-2755801463
Ref: Library<172>-Footnote-2765801530
Ref: Library<172>-Footnote-2775801597
Ref: Library<172>-Footnote-2785801664
Ref: Library<172>-Footnote-2795801731
Ref: Library<172>-Footnote-2805801798
Ref: Library<172>-Footnote-2815801865
Ref: Library<172>-Footnote-2825801932
Ref: Library<172>-Footnote-2835801999
Ref: Library<172>-Footnote-2845802066
Ref: Library<172>-Footnote-2855802133
Ref: Library<172>-Footnote-2865802200
Ref: Library<172>-Footnote-2875802267
Ref: Library<172>-Footnote-2885802334
Ref: Library<172>-Footnote-2895802401
Ref: Library<172>-Footnote-2905802468
Ref: Library<172>-Footnote-2915802535
Ref: Library<172>-Footnote-2925802602
Ref: Library<172>-Footnote-2935802669
Ref: Library<172>-Footnote-2945802736
Ref: Library<172>-Footnote-2955802803
Ref: Library<172>-Footnote-2965802870
Ref: Library<172>-Footnote-2975802937
Ref: Library<172>-Footnote-2985803004
Ref: Library<172>-Footnote-2995803071
Ref: Library<172>-Footnote-3005803138
Ref: Library<172>-Footnote-3015803205
Ref: Library<172>-Footnote-3025803272
Ref: Library<172>-Footnote-3035803339
Ref: Library<172>-Footnote-3045803406
Ref: Library<172>-Footnote-3055803473
Ref: Library<172>-Footnote-3065803540
Ref: Library<172>-Footnote-3075803607
Ref: Library<172>-Footnote-3085803674
Ref: Library<172>-Footnote-3095803741
Ref: Library<172>-Footnote-3105803808
Ref: Library<172>-Footnote-3115803875
Ref: Library<172>-Footnote-3125803942
Ref: Library<172>-Footnote-3135804009
Ref: Library<172>-Footnote-3145804076
Ref: Library<172>-Footnote-3155804143
Ref: Library<172>-Footnote-3165804210
Ref: Library<172>-Footnote-3175804277
Ref: Library<172>-Footnote-3185804344
Ref: Library<172>-Footnote-3195804411
Ref: Library<172>-Footnote-3205804478
Ref: Library<172>-Footnote-3215804545
Ref: Library<172>-Footnote-3225804612
Ref: Library<172>-Footnote-3235804679
Ref: Library<172>-Footnote-3245804746
Ref: Library<172>-Footnote-3255804813
Ref: Library<172>-Footnote-3265804880
Node: Documentation<65>5804947
Ref: whatsnew/changelog id8295805060
Ref: 1e815805060
Ref: Documentation<65>-Footnote-15807226
Ref: Documentation<65>-Footnote-25807291
Ref: Documentation<65>-Footnote-35807356
Ref: Documentation<65>-Footnote-45807421
Ref: Documentation<65>-Footnote-55807486
Ref: Documentation<65>-Footnote-65807551
Ref: Documentation<65>-Footnote-75807616
Ref: Documentation<65>-Footnote-85807681
Ref: Documentation<65>-Footnote-95807746
Ref: Documentation<65>-Footnote-105807811
Ref: Documentation<65>-Footnote-115807877
Ref: Documentation<65>-Footnote-125807943
Ref: Documentation<65>-Footnote-135808009
Ref: Documentation<65>-Footnote-145808075
Ref: Documentation<65>-Footnote-155808141
Ref: Documentation<65>-Footnote-165808207
Ref: Documentation<65>-Footnote-175808250
Node: Tests<62>5808316
Ref: whatsnew/changelog id8305808426
Ref: 1e845808426
Ref: Tests<62>-Footnote-15811186
Ref: Tests<62>-Footnote-25811251
Ref: Tests<62>-Footnote-35811316
Ref: Tests<62>-Footnote-45811381
Ref: Tests<62>-Footnote-55811446
Ref: Tests<62>-Footnote-65811511
Ref: Tests<62>-Footnote-75811576
Ref: Tests<62>-Footnote-85811641
Ref: Tests<62>-Footnote-95811706
Ref: Tests<62>-Footnote-105811771
Ref: Tests<62>-Footnote-115811837
Ref: Tests<62>-Footnote-125811903
Ref: Tests<62>-Footnote-135811969
Ref: Tests<62>-Footnote-145812035
Ref: Tests<62>-Footnote-155812101
Ref: Tests<62>-Footnote-165812167
Ref: Tests<62>-Footnote-175812233
Ref: Tests<62>-Footnote-185812299
Ref: Tests<62>-Footnote-195812365
Node: Build<70>5812431
Ref: whatsnew/changelog id8315812535
Ref: 1e855812535
Ref: Build<70>-Footnote-15817304
Ref: Build<70>-Footnote-25817369
Ref: Build<70>-Footnote-35817434
Ref: Build<70>-Footnote-45817499
Ref: Build<70>-Footnote-55817541
Ref: Build<70>-Footnote-65817606
Ref: Build<70>-Footnote-75817671
Ref: Build<70>-Footnote-85817736
Ref: Build<70>-Footnote-95817801
Ref: Build<70>-Footnote-105817866
Ref: Build<70>-Footnote-115817932
Ref: Build<70>-Footnote-125817998
Ref: Build<70>-Footnote-135818064
Ref: Build<70>-Footnote-145818130
Ref: Build<70>-Footnote-155818196
Ref: Build<70>-Footnote-165818262
Ref: Build<70>-Footnote-175818328
Ref: Build<70>-Footnote-185818394
Ref: Build<70>-Footnote-195818460
Ref: Build<70>-Footnote-205818526
Ref: Build<70>-Footnote-215818592
Ref: Build<70>-Footnote-225818658
Ref: Build<70>-Footnote-235818724
Ref: Build<70>-Footnote-245818790
Ref: Build<70>-Footnote-255818856
Ref: Build<70>-Footnote-265818922
Ref: Build<70>-Footnote-275818988
Ref: Build<70>-Footnote-285819054
Ref: Build<70>-Footnote-295819120
Ref: Build<70>-Footnote-305819186
Ref: Build<70>-Footnote-315819252
Ref: Build<70>-Footnote-325819318
Ref: Build<70>-Footnote-335819384
Ref: Build<70>-Footnote-345819450
Ref: Build<70>-Footnote-355819516
Ref: Build<70>-Footnote-365819582
Ref: Build<70>-Footnote-375819648
Node: Windows<62>5819714
Ref: whatsnew/changelog id8325819817
Ref: 1e865819817
Ref: Windows<62>-Footnote-15822303
Ref: Windows<62>-Footnote-25822368
Ref: Windows<62>-Footnote-35822433
Ref: Windows<62>-Footnote-45822498
Ref: Windows<62>-Footnote-55822563
Ref: Windows<62>-Footnote-65822628
Ref: Windows<62>-Footnote-75822693
Ref: Windows<62>-Footnote-85822758
Ref: Windows<62>-Footnote-95822823
Ref: Windows<62>-Footnote-105822888
Ref: Windows<62>-Footnote-115822954
Ref: Windows<62>-Footnote-125823020
Ref: Windows<62>-Footnote-135823086
Ref: Windows<62>-Footnote-145823152
Ref: Windows<62>-Footnote-155823218
Ref: Windows<62>-Footnote-165823284
Ref: Windows<62>-Footnote-175823350
Ref: Windows<62>-Footnote-185823416
Ref: Windows<62>-Footnote-195823482
Ref: Windows<62>-Footnote-205823548
Ref: Windows<62>-Footnote-215823614
Ref: Windows<62>-Footnote-225823680
Ref: Windows<62>-Footnote-235823746
Ref: Windows<62>-Footnote-245823812
Ref: Windows<62>-Footnote-255823878
Node: IDLE<45>5823944
Ref: whatsnew/changelog id8335824053
Ref: 1e875824053
Ref: IDLE<45>-Footnote-15834054
Ref: IDLE<45>-Footnote-25834119
Ref: IDLE<45>-Footnote-35834184
Ref: IDLE<45>-Footnote-45834249
Ref: IDLE<45>-Footnote-55834314
Ref: IDLE<45>-Footnote-65834379
Ref: IDLE<45>-Footnote-75834444
Ref: IDLE<45>-Footnote-85834509
Ref: IDLE<45>-Footnote-95834574
Ref: IDLE<45>-Footnote-105834639
Ref: IDLE<45>-Footnote-115834705
Ref: IDLE<45>-Footnote-125834771
Ref: IDLE<45>-Footnote-135834837
Ref: IDLE<45>-Footnote-145834903
Ref: IDLE<45>-Footnote-155834969
Ref: IDLE<45>-Footnote-165835035
Ref: IDLE<45>-Footnote-175835101
Ref: IDLE<45>-Footnote-185835167
Ref: IDLE<45>-Footnote-195835233
Ref: IDLE<45>-Footnote-205835299
Ref: IDLE<45>-Footnote-215835365
Ref: IDLE<45>-Footnote-225835431
Ref: IDLE<45>-Footnote-235835497
Ref: IDLE<45>-Footnote-245835563
Ref: IDLE<45>-Footnote-255835629
Ref: IDLE<45>-Footnote-265835695
Ref: IDLE<45>-Footnote-275835761
Ref: IDLE<45>-Footnote-285835827
Ref: IDLE<45>-Footnote-295835893
Ref: IDLE<45>-Footnote-305835959
Ref: IDLE<45>-Footnote-315836025
Ref: IDLE<45>-Footnote-325836091
Ref: IDLE<45>-Footnote-335836157
Ref: IDLE<45>-Footnote-345836223
Ref: IDLE<45>-Footnote-355836288
Ref: IDLE<45>-Footnote-365836354
Ref: IDLE<45>-Footnote-375836420
Ref: IDLE<45>-Footnote-385836486
Ref: IDLE<45>-Footnote-395836552
Ref: IDLE<45>-Footnote-405836618
Ref: IDLE<45>-Footnote-415836684
Ref: IDLE<45>-Footnote-425836750
Ref: IDLE<45>-Footnote-435836816
Ref: IDLE<45>-Footnote-445836881
Ref: IDLE<45>-Footnote-455836947
Ref: IDLE<45>-Footnote-465837013
Ref: IDLE<45>-Footnote-475837079
Ref: IDLE<45>-Footnote-485837145
Ref: IDLE<45>-Footnote-495837211
Ref: IDLE<45>-Footnote-505837277
Ref: IDLE<45>-Footnote-515837343
Node: Tools/Demos<43>5837409
Ref: whatsnew/changelog id8345837516
Ref: 1e885837516
Ref: Tools/Demos<43>-Footnote-15839002
Ref: Tools/Demos<43>-Footnote-25839067
Ref: Tools/Demos<43>-Footnote-35839109
Ref: Tools/Demos<43>-Footnote-45839174
Ref: Tools/Demos<43>-Footnote-55839239
Ref: Tools/Demos<43>-Footnote-65839304
Ref: Tools/Demos<43>-Footnote-75839369
Ref: Tools/Demos<43>-Footnote-85839434
Node: C API<63>5839499
Ref: whatsnew/changelog id8355839589
Ref: 1e895839589
Ref: C API<63>-Footnote-15842649
Ref: C API<63>-Footnote-25842714
Ref: C API<63>-Footnote-35842779
Ref: C API<63>-Footnote-45842844
Ref: C API<63>-Footnote-55842909
Ref: C API<63>-Footnote-65842973
Ref: C API<63>-Footnote-75843038
Ref: C API<63>-Footnote-85843103
Ref: C API<63>-Footnote-95843168
Ref: C API<63>-Footnote-105843233
Ref: C API<63>-Footnote-115843299
Ref: C API<63>-Footnote-125843365
Ref: C API<63>-Footnote-135843431
Ref: C API<63>-Footnote-145843497
Ref: C API<63>-Footnote-155843563
Node: Python 3 6 6 final5843629
Ref: whatsnew/changelog python-3-6-6-final5843763
Ref: 1e8a5843763
Node: Python 3 6 6 release candidate 15843891
Ref: whatsnew/changelog python-3-6-6-release-candidate-15844023
Ref: 1e8b5844023
Node: Core and Builtins<169>5844404
Ref: whatsnew/changelog id8365844516
Ref: 1e8c5844516
Ref: Core and Builtins<169>-Footnote-15846098
Ref: Core and Builtins<169>-Footnote-25846163
Ref: Core and Builtins<169>-Footnote-35846228
Ref: Core and Builtins<169>-Footnote-45846293
Ref: Core and Builtins<169>-Footnote-55846358
Ref: Core and Builtins<169>-Footnote-65846423
Ref: Core and Builtins<169>-Footnote-75846488
Ref: Core and Builtins<169>-Footnote-85846553
Ref: Core and Builtins<169>-Footnote-95846618
Ref: Core and Builtins<169>-Footnote-105846683
Ref: Core and Builtins<169>-Footnote-115846749
Ref: Core and Builtins<169>-Footnote-125846815
Node: Library<173>5846881
Ref: whatsnew/changelog id8375847019
Ref: 1e8d5847019
Ref: Library<173>-Footnote-15852496
Ref: Library<173>-Footnote-25852561
Ref: Library<173>-Footnote-35852626
Ref: Library<173>-Footnote-45852691
Ref: Library<173>-Footnote-55852756
Ref: Library<173>-Footnote-65852821
Ref: Library<173>-Footnote-75852886
Ref: Library<173>-Footnote-85852951
Ref: Library<173>-Footnote-95853016
Ref: Library<173>-Footnote-105853081
Ref: Library<173>-Footnote-115853147
Ref: Library<173>-Footnote-125853213
Ref: Library<173>-Footnote-135853279
Ref: Library<173>-Footnote-145853345
Ref: Library<173>-Footnote-155853411
Ref: Library<173>-Footnote-165853477
Ref: Library<173>-Footnote-175853543
Ref: Library<173>-Footnote-185853609
Ref: Library<173>-Footnote-195853675
Ref: Library<173>-Footnote-205853741
Ref: Library<173>-Footnote-215853807
Ref: Library<173>-Footnote-225853874
Ref: Library<173>-Footnote-235853940
Ref: Library<173>-Footnote-245854006
Ref: Library<173>-Footnote-255854072
Ref: Library<173>-Footnote-265854138
Ref: Library<173>-Footnote-275854204
Ref: Library<173>-Footnote-285854270
Ref: Library<173>-Footnote-295854313
Ref: Library<173>-Footnote-305854379
Ref: Library<173>-Footnote-315854445
Ref: Library<173>-Footnote-325854511
Ref: Library<173>-Footnote-335854577
Ref: Library<173>-Footnote-345854643
Ref: Library<173>-Footnote-355854709
Ref: Library<173>-Footnote-365854775
Ref: Library<173>-Footnote-375854841
Ref: Library<173>-Footnote-385854907
Ref: Library<173>-Footnote-395854973
Node: Documentation<66>5855039
Ref: whatsnew/changelog id8385855164
Ref: 1e8e5855164
Ref: Documentation<66>-Footnote-15856655
Ref: Documentation<66>-Footnote-25856720
Ref: Documentation<66>-Footnote-35856785
Ref: Documentation<66>-Footnote-45856850
Ref: Documentation<66>-Footnote-55856915
Ref: Documentation<66>-Footnote-65856980
Ref: Documentation<66>-Footnote-75857045
Ref: Documentation<66>-Footnote-85857110
Ref: Documentation<66>-Footnote-95857175
Ref: Documentation<66>-Footnote-105857240
Ref: Documentation<66>-Footnote-115857306
Ref: Documentation<66>-Footnote-125857372
Ref: Documentation<66>-Footnote-135857437
Node: Tests<63>5857503
Ref: whatsnew/changelog id8395857625
Ref: 1e8f5857625
Ref: Tests<63>-Footnote-15857847
Ref: Tests<63>-Footnote-25857912
Node: Build<71>5857977
Ref: whatsnew/changelog id8405858093
Ref: 1e905858093
Ref: Build<71>-Footnote-15858890
Ref: Build<71>-Footnote-25858954
Ref: Build<71>-Footnote-35859019
Ref: Build<71>-Footnote-45859084
Ref: Build<71>-Footnote-55859149
Node: Windows<63>5859214
Ref: whatsnew/changelog id8415859330
Ref: 1e915859330
Ref: Windows<63>-Footnote-15859467
Node: macOS<48>5859532
Ref: whatsnew/changelog id8425859647
Ref: 1e925859647
Ref: macOS<48>-Footnote-15859788
Node: IDLE<46>5859853
Ref: whatsnew/changelog id8435859972
Ref: 1e935859972
Ref: IDLE<46>-Footnote-15862041
Ref: IDLE<46>-Footnote-25862106
Ref: IDLE<46>-Footnote-35862171
Ref: IDLE<46>-Footnote-45862236
Ref: IDLE<46>-Footnote-55862301
Ref: IDLE<46>-Footnote-65862366
Ref: IDLE<46>-Footnote-75862431
Ref: IDLE<46>-Footnote-85862496
Ref: IDLE<46>-Footnote-95862561
Ref: IDLE<46>-Footnote-105862626
Ref: IDLE<46>-Footnote-115862692
Ref: IDLE<46>-Footnote-125862758
Node: Tools/Demos<44>5862824
Ref: whatsnew/changelog id8445862943
Ref: 1e945862943
Ref: Tools/Demos<44>-Footnote-15863698
Ref: Tools/Demos<44>-Footnote-25863763
Ref: Tools/Demos<44>-Footnote-35863828
Ref: Tools/Demos<44>-Footnote-45863893
Ref: Tools/Demos<44>-Footnote-55863958
Node: C API<64>5864023
Ref: whatsnew/changelog id8455864125
Ref: 1e955864125
Ref: C API<64>-Footnote-15864338
Node: Python 3 6 5 final5864403
Ref: whatsnew/changelog python-3-6-5-final5864549
Ref: 1e965864549
Node: Tests<64>5864682
Ref: whatsnew/changelog id8465864764
Ref: 1e975864764
Ref: Tests<64>-Footnote-15864918
Node: Build<72>5864983
Ref: whatsnew/changelog id8475865065
Ref: 1e985865065
Ref: Build<72>-Footnote-15865202
Node: Python 3 6 5 release candidate 15865267
Ref: whatsnew/changelog python-3-6-5-release-candidate-15865399
Ref: 1e995865399
Node: Security<50>5865806
Ref: whatsnew/changelog id8485865918
Ref: 1e9a5865918
Ref: Security<50>-Footnote-15866349
Ref: Security<50>-Footnote-25866414
Ref: Security<50>-Footnote-35866479
Ref: Security<50>-Footnote-45866534
Node: Core and Builtins<170>5866589
Ref: whatsnew/changelog id8495866722
Ref: 1e9b5866722
Ref: Core and Builtins<170>-Footnote-15868894
Ref: Core and Builtins<170>-Footnote-25868959
Ref: Core and Builtins<170>-Footnote-35869024
Ref: Core and Builtins<170>-Footnote-45869089
Ref: Core and Builtins<170>-Footnote-55869154
Ref: Core and Builtins<170>-Footnote-65869219
Ref: Core and Builtins<170>-Footnote-75869284
Ref: Core and Builtins<170>-Footnote-85869349
Ref: Core and Builtins<170>-Footnote-95869414
Ref: Core and Builtins<170>-Footnote-105869479
Ref: Core and Builtins<170>-Footnote-115869545
Ref: Core and Builtins<170>-Footnote-125869611
Ref: Core and Builtins<170>-Footnote-135869677
Ref: Core and Builtins<170>-Footnote-145869743
Node: Library<174>5869809
Ref: whatsnew/changelog id8505869947
Ref: 1e9c5869947
Ref: Library<174>-Footnote-15875874
Ref: Library<174>-Footnote-25875939
Ref: Library<174>-Footnote-35876004
Ref: Library<174>-Footnote-45876069
Ref: Library<174>-Footnote-55876134
Ref: Library<174>-Footnote-65876199
Ref: Library<174>-Footnote-75876264
Ref: Library<174>-Footnote-85876329
Ref: Library<174>-Footnote-95876394
Ref: Library<174>-Footnote-105876459
Ref: Library<174>-Footnote-115876525
Ref: Library<174>-Footnote-125876591
Ref: Library<174>-Footnote-135876657
Ref: Library<174>-Footnote-145876723
Ref: Library<174>-Footnote-155876789
Ref: Library<174>-Footnote-165876855
Ref: Library<174>-Footnote-175876921
Ref: Library<174>-Footnote-185876987
Ref: Library<174>-Footnote-195877053
Ref: Library<174>-Footnote-205877119
Ref: Library<174>-Footnote-215877185
Ref: Library<174>-Footnote-225877251
Ref: Library<174>-Footnote-235877317
Ref: Library<174>-Footnote-245877383
Ref: Library<174>-Footnote-255877449
Ref: Library<174>-Footnote-265877515
Ref: Library<174>-Footnote-275877581
Ref: Library<174>-Footnote-285877647
Ref: Library<174>-Footnote-295877713
Ref: Library<174>-Footnote-305877779
Ref: Library<174>-Footnote-315877845
Ref: Library<174>-Footnote-325877911
Ref: Library<174>-Footnote-335877977
Ref: Library<174>-Footnote-345878043
Ref: Library<174>-Footnote-355878109
Ref: Library<174>-Footnote-365878175
Ref: Library<174>-Footnote-375878241
Ref: Library<174>-Footnote-385878307
Ref: Library<174>-Footnote-395878373
Ref: Library<174>-Footnote-405878439
Node: Documentation<67>5878505
Ref: whatsnew/changelog id8515878630
Ref: 1e9d5878630
Ref: Documentation<67>-Footnote-15879466
Ref: Documentation<67>-Footnote-25879531
Ref: Documentation<67>-Footnote-35879596
Ref: Documentation<67>-Footnote-45879660
Ref: Documentation<67>-Footnote-55879725
Ref: Documentation<67>-Footnote-65879790
Node: Tests<65>5879855
Ref: whatsnew/changelog id8525879977
Ref: 1e9e5879977
Ref: Tests<65>-Footnote-15880638
Ref: Tests<65>-Footnote-25880703
Ref: Tests<65>-Footnote-35880768
Ref: Tests<65>-Footnote-45880833
Node: Build<73>5880898
Ref: whatsnew/changelog id8535881014
Ref: 1e9f5881014
Ref: Build<73>-Footnote-15881203
Node: Windows<64>5881268
Ref: whatsnew/changelog id8545881384
Ref: 1ea05881384
Ref: Windows<64>-Footnote-15882334
Ref: Windows<64>-Footnote-25882399
Ref: Windows<64>-Footnote-35882464
Ref: Windows<64>-Footnote-45882529
Ref: Windows<64>-Footnote-55882594
Ref: Windows<64>-Footnote-65882659
Ref: Windows<64>-Footnote-75882724
Ref: Windows<64>-Footnote-85882789
Node: macOS<49>5882854
Ref: whatsnew/changelog id8555882969
Ref: 1ea15882969
Ref: macOS<49>-Footnote-15883362
Node: IDLE<47>5883427
Ref: whatsnew/changelog id8565883546
Ref: 1ea25883546
Ref: IDLE<47>-Footnote-15885038
Ref: IDLE<47>-Footnote-25885103
Ref: IDLE<47>-Footnote-35885168
Ref: IDLE<47>-Footnote-45885233
Ref: IDLE<47>-Footnote-55885298
Ref: IDLE<47>-Footnote-65885363
Ref: IDLE<47>-Footnote-75885428
Ref: IDLE<47>-Footnote-85885493
Node: Tools/Demos<45>5885558
Ref: whatsnew/changelog id8575885677
Ref: 1ea35885677
Ref: Tools/Demos<45>-Footnote-15886097
Ref: Tools/Demos<45>-Footnote-25886162
Node: C API<65>5886227
Ref: whatsnew/changelog id8585886329
Ref: 1ea45886329
Ref: C API<65>-Footnote-15886579
Node: Python 3 6 4 final5886644
Ref: whatsnew/changelog python-3-6-4-final5886790
Ref: 1ea55886790
Node: Python 3 6 4 release candidate 15886939
Ref: whatsnew/changelog python-3-6-4-release-candidate-15887071
Ref: 1ea65887071
Node: Core and Builtins<171>5887452
Ref: whatsnew/changelog id8595887564
Ref: 1ea75887564
Ref: Core and Builtins<171>-Footnote-15892292
Ref: Core and Builtins<171>-Footnote-25892357
Ref: Core and Builtins<171>-Footnote-35892422
Ref: Core and Builtins<171>-Footnote-45892487
Ref: Core and Builtins<171>-Footnote-55892552
Ref: Core and Builtins<171>-Footnote-65892617
Ref: Core and Builtins<171>-Footnote-75892682
Ref: Core and Builtins<171>-Footnote-85892747
Ref: Core and Builtins<171>-Footnote-95892812
Ref: Core and Builtins<171>-Footnote-105892877
Ref: Core and Builtins<171>-Footnote-115892943
Ref: Core and Builtins<171>-Footnote-125893009
Ref: Core and Builtins<171>-Footnote-135893075
Ref: Core and Builtins<171>-Footnote-145893141
Ref: Core and Builtins<171>-Footnote-155893207
Ref: Core and Builtins<171>-Footnote-165893273
Ref: Core and Builtins<171>-Footnote-175893339
Ref: Core and Builtins<171>-Footnote-185893405
Ref: Core and Builtins<171>-Footnote-195893471
Ref: Core and Builtins<171>-Footnote-205893537
Ref: Core and Builtins<171>-Footnote-215893603
Ref: Core and Builtins<171>-Footnote-225893669
Ref: Core and Builtins<171>-Footnote-235893735
Ref: Core and Builtins<171>-Footnote-245893801
Node: Library<175>5893867
Ref: whatsnew/changelog id8605894005
Ref: 1ea85894005
Ref: Library<175>-Footnote-15901330
Ref: Library<175>-Footnote-25901395
Ref: Library<175>-Footnote-35901460
Ref: Library<175>-Footnote-45901525
Ref: Library<175>-Footnote-55901590
Ref: Library<175>-Footnote-65901655
Ref: Library<175>-Footnote-75901720
Ref: Library<175>-Footnote-85901785
Ref: Library<175>-Footnote-95901850
Ref: Library<175>-Footnote-105901915
Ref: Library<175>-Footnote-115901981
Ref: Library<175>-Footnote-125902047
Ref: Library<175>-Footnote-135902113
Ref: Library<175>-Footnote-145902179
Ref: Library<175>-Footnote-155902245
Ref: Library<175>-Footnote-165902311
Ref: Library<175>-Footnote-175902376
Ref: Library<175>-Footnote-185902442
Ref: Library<175>-Footnote-195902508
Ref: Library<175>-Footnote-205902574
Ref: Library<175>-Footnote-215902640
Ref: Library<175>-Footnote-225902706
Ref: Library<175>-Footnote-235902772
Ref: Library<175>-Footnote-245902838
Ref: Library<175>-Footnote-255902904
Ref: Library<175>-Footnote-265902970
Ref: Library<175>-Footnote-275903036
Ref: Library<175>-Footnote-285903102
Ref: Library<175>-Footnote-295903168
Ref: Library<175>-Footnote-305903234
Ref: Library<175>-Footnote-315903300
Ref: Library<175>-Footnote-325903366
Ref: Library<175>-Footnote-335903432
Ref: Library<175>-Footnote-345903498
Ref: Library<175>-Footnote-355903564
Ref: Library<175>-Footnote-365903630
Ref: Library<175>-Footnote-375903696
Ref: Library<175>-Footnote-385903762
Ref: Library<175>-Footnote-395903828
Ref: Library<175>-Footnote-405903894
Ref: Library<175>-Footnote-415903960
Ref: Library<175>-Footnote-425904026
Ref: Library<175>-Footnote-435904092
Ref: Library<175>-Footnote-445904158
Ref: Library<175>-Footnote-455904224
Ref: Library<175>-Footnote-465904290
Ref: Library<175>-Footnote-475904356
Ref: Library<175>-Footnote-485904422
Ref: Library<175>-Footnote-495904488
Ref: Library<175>-Footnote-505904554
Ref: Library<175>-Footnote-515904620
Ref: Library<175>-Footnote-525904686
Node: Documentation<68>5904752
Ref: whatsnew/changelog id8615904877
Ref: 1ea95904877
Ref: Documentation<68>-Footnote-15905366
Ref: Documentation<68>-Footnote-25905431
Ref: Documentation<68>-Footnote-35905496
Node: Tests<66>5905561
Ref: whatsnew/changelog id8625905683
Ref: 1eaa5905683
Ref: Tests<66>-Footnote-15906361
Ref: Tests<66>-Footnote-25906426
Ref: Tests<66>-Footnote-35906491
Ref: Tests<66>-Footnote-45906556
Node: Build<74>5906621
Ref: whatsnew/changelog id8635906737
Ref: 1eab5906737
Ref: Build<74>-Footnote-15907641
Ref: Build<74>-Footnote-25907706
Ref: Build<74>-Footnote-35907771
Ref: Build<74>-Footnote-45907836
Ref: Build<74>-Footnote-55907901
Ref: Build<74>-Footnote-65907966
Ref: Build<74>-Footnote-75908031
Ref: Build<74>-Footnote-85908096
Ref: Build<74>-Footnote-95908161
Node: Windows<65>5908226
Ref: whatsnew/changelog id8645908342
Ref: 1eac5908342
Ref: Windows<65>-Footnote-15908660
Ref: Windows<65>-Footnote-25908724
Node: macOS<50>5908789
Ref: whatsnew/changelog id8655908904
Ref: 1ead5908904
Ref: macOS<50>-Footnote-15909038
Node: IDLE<48>5909103
Ref: whatsnew/changelog id8665909222
Ref: 1eae5909222
Ref: IDLE<48>-Footnote-15912559
Ref: IDLE<48>-Footnote-25912624
Ref: IDLE<48>-Footnote-35912689
Ref: IDLE<48>-Footnote-45912754
Ref: IDLE<48>-Footnote-55912819
Ref: IDLE<48>-Footnote-65912884
Ref: IDLE<48>-Footnote-75912949
Ref: IDLE<48>-Footnote-85913014
Ref: IDLE<48>-Footnote-95913079
Ref: IDLE<48>-Footnote-105913144
Ref: IDLE<48>-Footnote-115913210
Ref: IDLE<48>-Footnote-125913276
Ref: IDLE<48>-Footnote-135913342
Ref: IDLE<48>-Footnote-145913408
Node: Tools/Demos<46>5913476
Ref: whatsnew/changelog id8675913595
Ref: 1eaf5913595
Ref: Tools/Demos<46>-Footnote-15913885
Node: C API<66>5913950
Ref: whatsnew/changelog id8685914052
Ref: 1eb05914052
Ref: C API<66>-Footnote-15914780
Ref: C API<66>-Footnote-25914845
Ref: C API<66>-Footnote-35914910
Ref: C API<66>-Footnote-45914975
Node: Python 3 6 3 final5915040
Ref: whatsnew/changelog python-3-6-3-final5915186
Ref: 1eb15915186
Node: Library<176>5915324
Ref: whatsnew/changelog id8695915409
Ref: 1eb25915409
Ref: Library<176>-Footnote-15915611
Node: Build<75>5915676
Ref: whatsnew/changelog id8705915761
Ref: 1eb35915761
Ref: Build<75>-Footnote-15916052
Ref: Build<75>-Footnote-25916117
Node: Python 3 6 3 release candidate 15916182
Ref: whatsnew/changelog python-3-6-3-release-candidate-15916314
Ref: 1eb45916314
Node: Security<51>5916681
Ref: whatsnew/changelog id8715916793
Ref: 1eb55916793
Ref: Security<51>-Footnote-15917099
Ref: Security<51>-Footnote-25917164
Node: Core and Builtins<172>5917229
Ref: whatsnew/changelog id8725917362
Ref: 1eb65917362
Ref: Core and Builtins<172>-Footnote-15920894
Ref: Core and Builtins<172>-Footnote-25920959
Ref: Core and Builtins<172>-Footnote-35921024
Ref: Core and Builtins<172>-Footnote-45921089
Ref: Core and Builtins<172>-Footnote-55921154
Ref: Core and Builtins<172>-Footnote-65921219
Ref: Core and Builtins<172>-Footnote-75921284
Ref: Core and Builtins<172>-Footnote-85921349
Ref: Core and Builtins<172>-Footnote-95921414
Ref: Core and Builtins<172>-Footnote-105921479
Ref: Core and Builtins<172>-Footnote-115921545
Ref: Core and Builtins<172>-Footnote-125921611
Ref: Core and Builtins<172>-Footnote-135921677
Ref: Core and Builtins<172>-Footnote-145921743
Ref: Core and Builtins<172>-Footnote-155921809
Ref: Core and Builtins<172>-Footnote-165921875
Ref: Core and Builtins<172>-Footnote-175921941
Ref: Core and Builtins<172>-Footnote-185922007
Ref: Core and Builtins<172>-Footnote-195922073
Ref: Core and Builtins<172>-Footnote-205922139
Ref: Core and Builtins<172>-Footnote-215922205
Ref: Core and Builtins<172>-Footnote-225922271
Node: Library<177>5922337
Ref: whatsnew/changelog id8735922475
Ref: 1eb75922475
Ref: Library<177>-Footnote-15928474
Ref: Library<177>-Footnote-25928539
Ref: Library<177>-Footnote-35928604
Ref: Library<177>-Footnote-45928669
Ref: Library<177>-Footnote-55928734
Ref: Library<177>-Footnote-65928799
Ref: Library<177>-Footnote-75928864
Ref: Library<177>-Footnote-85928929
Ref: Library<177>-Footnote-95928994
Ref: Library<177>-Footnote-105929059
Ref: Library<177>-Footnote-115929125
Ref: Library<177>-Footnote-125929191
Ref: Library<177>-Footnote-135929257
Ref: Library<177>-Footnote-145929323
Ref: Library<177>-Footnote-155929389
Ref: Library<177>-Footnote-165929454
Ref: Library<177>-Footnote-175929520
Ref: Library<177>-Footnote-185929586
Ref: Library<177>-Footnote-195929629
Ref: Library<177>-Footnote-205929695
Ref: Library<177>-Footnote-215929761
Ref: Library<177>-Footnote-225929827
Ref: Library<177>-Footnote-235929893
Ref: Library<177>-Footnote-245929959
Ref: Library<177>-Footnote-255930025
Ref: Library<177>-Footnote-265930091
Ref: Library<177>-Footnote-275930157
Ref: Library<177>-Footnote-285930223
Ref: Library<177>-Footnote-295930289
Ref: Library<177>-Footnote-305930355
Ref: Library<177>-Footnote-315930421
Ref: Library<177>-Footnote-325930487
Ref: Library<177>-Footnote-335930553
Ref: Library<177>-Footnote-345930619
Ref: Library<177>-Footnote-355930685
Ref: Library<177>-Footnote-365930751
Ref: Library<177>-Footnote-375930817
Ref: Library<177>-Footnote-385930883
Ref: Library<177>-Footnote-395930949
Ref: Library<177>-Footnote-405931015
Ref: Library<177>-Footnote-415931081
Ref: Library<177>-Footnote-425931147
Node: Documentation<69>5931213
Ref: whatsnew/changelog id8745931338
Ref: 1eb85931338
Ref: Documentation<69>-Footnote-15931761
Ref: Documentation<69>-Footnote-25931826
Ref: Documentation<69>-Footnote-35931891
Node: Tests<67>5931956
Ref: whatsnew/changelog id8755932078
Ref: 1eb95932078
Ref: Tests<67>-Footnote-15932783
Ref: Tests<67>-Footnote-25932848
Ref: Tests<67>-Footnote-35932913
Ref: Tests<67>-Footnote-45932978
Node: Build<76>5933043
Ref: whatsnew/changelog id8765933159
Ref: 1eba5933159
Ref: Build<76>-Footnote-15933334
Node: Windows<66>5933399
Ref: whatsnew/changelog id8775933514
Ref: 1ebb5933514
Ref: Windows<66>-Footnote-15934022
Ref: Windows<66>-Footnote-25934087
Ref: Windows<66>-Footnote-35934152
Ref: Windows<66>-Footnote-45934217
Node: IDLE<49>5934282
Ref: whatsnew/changelog id8785934403
Ref: 1ebc5934403
Ref: IDLE<49>-Footnote-15943236
Ref: IDLE<49>-Footnote-25943301
Ref: IDLE<49>-Footnote-35943366
Ref: IDLE<49>-Footnote-45943431
Ref: IDLE<49>-Footnote-55943496
Ref: IDLE<49>-Footnote-65943561
Ref: IDLE<49>-Footnote-75943626
Ref: IDLE<49>-Footnote-85943691
Ref: IDLE<49>-Footnote-95943756
Ref: IDLE<49>-Footnote-105943821
Ref: IDLE<49>-Footnote-115943887
Ref: IDLE<49>-Footnote-125943953
Ref: IDLE<49>-Footnote-135944019
Ref: IDLE<49>-Footnote-145944085
Ref: IDLE<49>-Footnote-155944151
Ref: IDLE<49>-Footnote-165944217
Ref: IDLE<49>-Footnote-175944283
Ref: IDLE<49>-Footnote-185944349
Ref: IDLE<49>-Footnote-195944415
Ref: IDLE<49>-Footnote-205944481
Ref: IDLE<49>-Footnote-215944547
Ref: IDLE<49>-Footnote-225944613
Ref: IDLE<49>-Footnote-235944679
Ref: IDLE<49>-Footnote-245944745
Ref: IDLE<49>-Footnote-255944811
Ref: IDLE<49>-Footnote-265944877
Ref: IDLE<49>-Footnote-275944943
Ref: IDLE<49>-Footnote-285945009
Ref: IDLE<49>-Footnote-295945075
Ref: IDLE<49>-Footnote-305945141
Ref: IDLE<49>-Footnote-315945207
Ref: IDLE<49>-Footnote-325945273
Ref: IDLE<49>-Footnote-335945339
Ref: IDLE<49>-Footnote-345945405
Ref: IDLE<49>-Footnote-355945470
Ref: IDLE<49>-Footnote-365945536
Ref: IDLE<49>-Footnote-375945602
Ref: IDLE<49>-Footnote-385945668
Ref: IDLE<49>-Footnote-395945734
Ref: IDLE<49>-Footnote-405945800
Ref: IDLE<49>-Footnote-415945866
Ref: IDLE<49>-Footnote-425945932
Ref: IDLE<49>-Footnote-435945998
Node: Tools/Demos<47>5946063
Ref: whatsnew/changelog id8795946164
Ref: 1ebd5946164
Ref: Tools/Demos<47>-Footnote-15946724
Ref: Tools/Demos<47>-Footnote-25946789
Node: Python 3 6 2 final5946831
Ref: whatsnew/changelog python-3-6-2-final5946977
Ref: 1ebe5946977
Node: Python 3 6 2 release candidate 25947098
Ref: whatsnew/changelog python-3-6-2-release-candidate-25947244
Ref: 1ebf5947244
Node: Security<52>5947391
Ref: whatsnew/changelog id8805947472
Ref: 1ec05947472
Ref: Security<52>-Footnote-15948597
Ref: Security<52>-Footnote-25948662
Ref: Security<52>-Footnote-35948727
Ref: Security<52>-Footnote-45948782
Ref: Security<52>-Footnote-55948837
Ref: Security<52>-Footnote-65948892
Ref: Security<52>-Footnote-75948947
Ref: Security<52>-Footnote-85949002
Ref: Security<52>-Footnote-95949057
Node: Python 3 6 2 release candidate 15949122
Ref: whatsnew/changelog python-3-6-2-release-candidate-15949268
Ref: 1ec15949268
Node: Security<53>5949655
Ref: whatsnew/changelog id8815949767
Ref: 1ec25949767
Ref: Security<53>-Footnote-15950040
Ref: Security<53>-Footnote-25950105
Ref: Security<53>-Footnote-35950160
Node: Core and Builtins<173>5950215
Ref: whatsnew/changelog id8825950348
Ref: 1ec35950348
Ref: Core and Builtins<173>-Footnote-15952344
Ref: Core and Builtins<173>-Footnote-25952409
Ref: Core and Builtins<173>-Footnote-35952474
Ref: Core and Builtins<173>-Footnote-45952539
Ref: Core and Builtins<173>-Footnote-55952604
Ref: Core and Builtins<173>-Footnote-65952669
Ref: Core and Builtins<173>-Footnote-75952734
Ref: Core and Builtins<173>-Footnote-85952799
Ref: Core and Builtins<173>-Footnote-95952864
Ref: Core and Builtins<173>-Footnote-105952929
Ref: Core and Builtins<173>-Footnote-115952995
Ref: Core and Builtins<173>-Footnote-125953061
Ref: Core and Builtins<173>-Footnote-135953127
Ref: Core and Builtins<173>-Footnote-145953193
Ref: Core and Builtins<173>-Footnote-155953259
Node: Library<178>5953325
Ref: whatsnew/changelog id8835953454
Ref: 1ec45953454
Ref: Library<178>-Footnote-15961876
Ref: Library<178>-Footnote-25961941
Ref: Library<178>-Footnote-35962006
Ref: Library<178>-Footnote-45962071
Ref: Library<178>-Footnote-55962136
Ref: Library<178>-Footnote-65962201
Ref: Library<178>-Footnote-75962266
Ref: Library<178>-Footnote-85962331
Ref: Library<178>-Footnote-95962396
Ref: Library<178>-Footnote-105962461
Ref: Library<178>-Footnote-115962527
Ref: Library<178>-Footnote-125962593
Ref: Library<178>-Footnote-135962659
Ref: Library<178>-Footnote-145962725
Ref: Library<178>-Footnote-155962791
Ref: Library<178>-Footnote-165962857
Ref: Library<178>-Footnote-175962923
Ref: Library<178>-Footnote-185962989
Ref: Library<178>-Footnote-195963055
Ref: Library<178>-Footnote-205963121
Ref: Library<178>-Footnote-215963187
Ref: Library<178>-Footnote-225963253
Ref: Library<178>-Footnote-235963319
Ref: Library<178>-Footnote-245963385
Ref: Library<178>-Footnote-255963451
Ref: Library<178>-Footnote-265963517
Ref: Library<178>-Footnote-275963583
Ref: Library<178>-Footnote-285963649
Ref: Library<178>-Footnote-295963715
Ref: Library<178>-Footnote-305963781
Ref: Library<178>-Footnote-315963847
Ref: Library<178>-Footnote-325963913
Ref: Library<178>-Footnote-335963979
Ref: Library<178>-Footnote-345964045
Ref: Library<178>-Footnote-355964111
Ref: Library<178>-Footnote-365964177
Ref: Library<178>-Footnote-375964243
Ref: Library<178>-Footnote-385964309
Ref: Library<178>-Footnote-395964375
Ref: Library<178>-Footnote-405964441
Ref: Library<178>-Footnote-415964507
Ref: Library<178>-Footnote-425964573
Ref: Library<178>-Footnote-435964639
Ref: Library<178>-Footnote-445964705
Ref: Library<178>-Footnote-455964771
Ref: Library<178>-Footnote-465964837
Ref: Library<178>-Footnote-475964903
Ref: Library<178>-Footnote-485964969
Ref: Library<178>-Footnote-495965035
Ref: Library<178>-Footnote-505965101
Ref: Library<178>-Footnote-515965167
Ref: Library<178>-Footnote-525965233
Ref: Library<178>-Footnote-535965299
Ref: Library<178>-Footnote-545965365
Ref: Library<178>-Footnote-555965431
Ref: Library<178>-Footnote-565965496
Ref: Library<178>-Footnote-575965562
Ref: Library<178>-Footnote-585965628
Ref: Library<178>-Footnote-595965694
Ref: Library<178>-Footnote-605965760
Node: IDLE<50>5965826
Ref: whatsnew/changelog id8845965942
Ref: 1ec55965942
Ref: IDLE<50>-Footnote-15966947
Ref: IDLE<50>-Footnote-25967012
Ref: IDLE<50>-Footnote-35967077
Ref: IDLE<50>-Footnote-45967142
Ref: IDLE<50>-Footnote-55967207
Ref: IDLE<50>-Footnote-65967272
Node: C API<67>5967337
Ref: whatsnew/changelog id8855967450
Ref: 1ec65967450
Ref: C API<67>-Footnote-15967638
Node: Build<77>5967703
Ref: whatsnew/changelog id8865967825
Ref: 1ec75967825
Ref: Build<77>-Footnote-15968634
Ref: Build<77>-Footnote-25968699
Ref: Build<77>-Footnote-35968764
Ref: Build<77>-Footnote-45968829
Ref: Build<77>-Footnote-55968894
Node: Documentation<70>5968959
Ref: whatsnew/changelog id8875969087
Ref: 1ec85969087
Ref: Documentation<70>-Footnote-15969816
Ref: Documentation<70>-Footnote-25969881
Ref: Documentation<70>-Footnote-35969946
Node: Tools/Demos<48>5970011
Ref: whatsnew/changelog id8885970139
Ref: 1ec95970139
Ref: Tools/Demos<48>-Footnote-15970329
Node: Tests<68>5970394
Ref: whatsnew/changelog id8895970516
Ref: 1eca5970516
Ref: Tests<68>-Footnote-15971175
Ref: Tests<68>-Footnote-25971240
Node: Windows<67>5971305
Ref: whatsnew/changelog id8905971403
Ref: 1ecb5971403
Ref: Windows<67>-Footnote-15971847
Ref: Windows<67>-Footnote-25971912
Node: Python 3 6 1 final5971977
Ref: whatsnew/changelog python-3-6-1-final5972123
Ref: 1ecc5972123
Node: Core and Builtins<174>5972281
Ref: whatsnew/changelog id8915972376
Ref: 1ecd5972376
Ref: Core and Builtins<174>-Footnote-15972995
Ref: Core and Builtins<174>-Footnote-25973060
Node: Build<78>5973125
Ref: whatsnew/changelog id8925973220
Ref: 1ece5973220
Ref: Build<78>-Footnote-15973402
Node: Python 3 6 1 release candidate 15973467
Ref: whatsnew/changelog python-3-6-1-release-candidate-15973599
Ref: 1ecf5973599
Node: Core and Builtins<175>5973928
Ref: whatsnew/changelog id8935974040
Ref: 1ed05974040
Ref: Core and Builtins<175>-Footnote-15976872
Ref: Core and Builtins<175>-Footnote-25976937
Ref: Core and Builtins<175>-Footnote-35977002
Ref: Core and Builtins<175>-Footnote-45977067
Ref: Core and Builtins<175>-Footnote-55977132
Ref: Core and Builtins<175>-Footnote-65977197
Ref: Core and Builtins<175>-Footnote-75977262
Ref: Core and Builtins<175>-Footnote-85977327
Ref: Core and Builtins<175>-Footnote-95977392
Ref: Core and Builtins<175>-Footnote-105977457
Ref: Core and Builtins<175>-Footnote-115977523
Ref: Core and Builtins<175>-Footnote-125977589
Ref: Core and Builtins<175>-Footnote-135977655
Ref: Core and Builtins<175>-Footnote-145977721
Ref: Core and Builtins<175>-Footnote-155977787
Ref: Core and Builtins<175>-Footnote-165977853
Ref: Core and Builtins<175>-Footnote-175977919
Ref: Core and Builtins<175>-Footnote-185977985
Ref: Core and Builtins<175>-Footnote-195978051
Ref: Core and Builtins<175>-Footnote-205978117
Ref: Core and Builtins<175>-Footnote-215978183
Ref: Core and Builtins<175>-Footnote-225978249
Node: Library<179>5978315
Ref: whatsnew/changelog id8945978444
Ref: 1ed15978444
Ref: Library<179>-Footnote-15984087
Ref: Library<179>-Footnote-25984152
Ref: Library<179>-Footnote-35984217
Ref: Library<179>-Footnote-45984282
Ref: Library<179>-Footnote-55984347
Ref: Library<179>-Footnote-65984412
Ref: Library<179>-Footnote-75984477
Ref: Library<179>-Footnote-85984542
Ref: Library<179>-Footnote-95984607
Ref: Library<179>-Footnote-105984672
Ref: Library<179>-Footnote-115984738
Ref: Library<179>-Footnote-125984804
Ref: Library<179>-Footnote-135984870
Ref: Library<179>-Footnote-145984936
Ref: Library<179>-Footnote-155985002
Ref: Library<179>-Footnote-165985068
Ref: Library<179>-Footnote-175985134
Ref: Library<179>-Footnote-185985200
Ref: Library<179>-Footnote-195985266
Ref: Library<179>-Footnote-205985332
Ref: Library<179>-Footnote-215985398
Ref: Library<179>-Footnote-225985464
Ref: Library<179>-Footnote-235985530
Ref: Library<179>-Footnote-245985596
Ref: Library<179>-Footnote-255985662
Ref: Library<179>-Footnote-265985728
Ref: Library<179>-Footnote-275985794
Ref: Library<179>-Footnote-285985837
Ref: Library<179>-Footnote-295985903
Ref: Library<179>-Footnote-305985969
Ref: Library<179>-Footnote-315986035
Ref: Library<179>-Footnote-325986101
Ref: Library<179>-Footnote-335986167
Ref: Library<179>-Footnote-345986233
Ref: Library<179>-Footnote-355986299
Ref: Library<179>-Footnote-365986364
Ref: Library<179>-Footnote-375986430
Ref: Library<179>-Footnote-385986496
Ref: Library<179>-Footnote-395986562
Ref: Library<179>-Footnote-405986628
Ref: Library<179>-Footnote-415986694
Ref: Library<179>-Footnote-425986760
Ref: Library<179>-Footnote-435986826
Ref: Library<179>-Footnote-445986892
Node: IDLE<51>5986958
Ref: whatsnew/changelog id8955987076
Ref: 1ed25987076
Ref: IDLE<51>-Footnote-15987365
Ref: IDLE<51>-Footnote-25987430
Node: Windows<68>5987495
Ref: whatsnew/changelog id8965987610
Ref: 1ed35987610
Ref: Windows<68>-Footnote-15988257
Ref: Windows<68>-Footnote-25988322
Ref: Windows<68>-Footnote-35988387
Ref: Windows<68>-Footnote-45988452
Ref: Windows<68>-Footnote-55988517
Ref: Windows<68>-Footnote-65988559
Ref: Windows<68>-Footnote-75988624
Ref: Windows<68>-Footnote-85988689
Node: C API<68>5988754
Ref: whatsnew/changelog id8975988878
Ref: 1ed45988878
Ref: C API<68>-Footnote-15989704
Ref: C API<68>-Footnote-25989769
Ref: C API<68>-Footnote-35989834
Node: Documentation<71>5989899
Ref: whatsnew/changelog id8985990021
Ref: 1ed55990021
Ref: Documentation<71>-Footnote-15990558
Ref: Documentation<71>-Footnote-25990623
Ref: Documentation<71>-Footnote-35990688
Ref: Documentation<71>-Footnote-45990753
Node: Tests<69>5990818
Ref: whatsnew/changelog id8995990940
Ref: 1ed65990940
Ref: Tests<69>-Footnote-15991925
Ref: Tests<69>-Footnote-25991990
Ref: Tests<69>-Footnote-35992055
Ref: Tests<69>-Footnote-45992120
Ref: Tests<69>-Footnote-55992185
Node: Build<79>5992250
Ref: whatsnew/changelog id9005992346
Ref: 1ed75992346
Ref: Build<79>-Footnote-15993607
Ref: Build<79>-Footnote-25993672
Ref: Build<79>-Footnote-35993737
Ref: Build<79>-Footnote-45993802
Ref: Build<79>-Footnote-55993867
Ref: Build<79>-Footnote-65993932
Ref: Build<79>-Footnote-75993997
Ref: Build<79>-Footnote-85994062
Ref: Build<79>-Footnote-95994127
Ref: Build<79>-Footnote-105994192
Node: Python 3 6 0 final5994258
Ref: whatsnew/changelog python-3-6-0-final5994404
Ref: 1ed85994404
Node: Python 3 6 0 release candidate 25994525
Ref: whatsnew/changelog python-3-6-0-release-candidate-25994671
Ref: 1ed95994671
Node: Core and Builtins<176>5994913
Ref: whatsnew/changelog id9015995028
Ref: 1eda5995028
Ref: Core and Builtins<176>-Footnote-15995413
Ref: Core and Builtins<176>-Footnote-25995478
Node: Tools/Demos<49>5995543
Ref: whatsnew/changelog id9025995678
Ref: 1edb5995678
Ref: Tools/Demos<49>-Footnote-15995812
Node: Windows<69>5995877
Ref: whatsnew/changelog id9035995999
Ref: 1edc5995999
Ref: Windows<69>-Footnote-15996125
Node: Build<80>5996190
Ref: whatsnew/changelog id9045996288
Ref: 1edd5996288
Ref: Build<80>-Footnote-15996443
Node: Python 3 6 0 release candidate 15996508
Ref: whatsnew/changelog python-3-6-0-release-candidate-15996655
Ref: 1ede5996655
Node: Core and Builtins<177>5996934
Ref: whatsnew/changelog id9055997046
Ref: 1edf5997046
Ref: Core and Builtins<177>-Footnote-15997855
Ref: Core and Builtins<177>-Footnote-25997920
Ref: Core and Builtins<177>-Footnote-35997985
Ref: Core and Builtins<177>-Footnote-45998050
Node: Library<180>5998115
Ref: whatsnew/changelog id9065998245
Ref: 1ee05998245
Ref: Library<180>-Footnote-15999284
Ref: Library<180>-Footnote-25999349
Ref: Library<180>-Footnote-35999414
Ref: Library<180>-Footnote-45999479
Ref: Library<180>-Footnote-55999544
Ref: Library<180>-Footnote-65999609
Node: C API<69>5999674
Ref: whatsnew/changelog id9075999799
Ref: 1ee15999799
Ref: C API<69>-Footnote-15999957
Node: Documentation<72>6000022
Ref: whatsnew/changelog id9086000150
Ref: 1ee26000150
Ref: Documentation<72>-Footnote-16000490
Ref: Documentation<72>-Footnote-26000555
Node: Tools/Demos<50>6000597
Ref: whatsnew/changelog id9096000707
Ref: 1ee36000707
Ref: Tools/Demos<50>-Footnote-16000873
Node: Python 3 6 0 beta 46000938
Ref: whatsnew/changelog python-3-6-0-beta-46001072
Ref: 1ee46001072
Node: Core and Builtins<178>6001313
Ref: whatsnew/changelog id9106001412
Ref: 1ee56001412
Ref: Core and Builtins<178>-Footnote-16002964
Ref: Core and Builtins<178>-Footnote-26003029
Ref: Core and Builtins<178>-Footnote-36003094
Ref: Core and Builtins<178>-Footnote-46003159
Ref: Core and Builtins<178>-Footnote-56003224
Ref: Core and Builtins<178>-Footnote-66003289
Ref: Core and Builtins<178>-Footnote-76003354
Ref: Core and Builtins<178>-Footnote-86003419
Ref: Core and Builtins<178>-Footnote-96003484
Ref: Core and Builtins<178>-Footnote-106003549
Ref: Core and Builtins<178>-Footnote-116003615
Node: Library<181>6003681
Ref: whatsnew/changelog id9116003806
Ref: 1ee66003806
Ref: Library<181>-Footnote-16005808
Ref: Library<181>-Footnote-26005873
Ref: Library<181>-Footnote-36005938
Ref: Library<181>-Footnote-46006003
Ref: Library<181>-Footnote-56006068
Ref: Library<181>-Footnote-66006133
Ref: Library<181>-Footnote-76006198
Ref: Library<181>-Footnote-86006263
Ref: Library<181>-Footnote-96006328
Ref: Library<181>-Footnote-106006393
Ref: Library<181>-Footnote-116006459
Ref: Library<181>-Footnote-126006525
Ref: Library<181>-Footnote-136006591
Ref: Library<181>-Footnote-146006657
Ref: Library<181>-Footnote-156006723
Ref: Library<181>-Footnote-166006789
Ref: Library<181>-Footnote-176006855
Ref: Library<181>-Footnote-186006921
Node: Documentation<73>6006987
Ref: whatsnew/changelog id9126007099
Ref: 1ee76007099
Ref: Documentation<73>-Footnote-16007250
Node: Tests<70>6007315
Ref: whatsnew/changelog id9136007424
Ref: 1ee86007424
Ref: Tests<70>-Footnote-16007686
Ref: Tests<70>-Footnote-26007751
Node: Build<81>6007816
Ref: whatsnew/changelog id9146007899
Ref: 1ee96007899
Ref: Build<81>-Footnote-16008262
Ref: Build<81>-Footnote-26008327
Ref: Build<81>-Footnote-36008392
Node: Python 3 6 0 beta 36008457
Ref: whatsnew/changelog python-3-6-0-beta-36008578
Ref: 1eea6008578
Node: Core and Builtins<179>6008807
Ref: whatsnew/changelog id9156008906
Ref: 1eeb6008906
Ref: Core and Builtins<179>-Footnote-16009811
Ref: Core and Builtins<179>-Footnote-26009876
Ref: Core and Builtins<179>-Footnote-36009941
Ref: Core and Builtins<179>-Footnote-46010006
Ref: Core and Builtins<179>-Footnote-56010071
Ref: Core and Builtins<179>-Footnote-66010136
Ref: Core and Builtins<179>-Footnote-76010201
Node: Library<182>6010266
Ref: whatsnew/changelog id9166010385
Ref: 1eec6010385
Ref: Library<182>-Footnote-16013424
Ref: Library<182>-Footnote-26013489
Ref: Library<182>-Footnote-36013554
Ref: Library<182>-Footnote-46013619
Ref: Library<182>-Footnote-56013684
Ref: Library<182>-Footnote-66013749
Ref: Library<182>-Footnote-76013814
Ref: Library<182>-Footnote-86013879
Ref: Library<182>-Footnote-96013944
Ref: Library<182>-Footnote-106014009
Ref: Library<182>-Footnote-116014075
Ref: Library<182>-Footnote-126014141
Ref: Library<182>-Footnote-136014207
Ref: Library<182>-Footnote-146014273
Ref: Library<182>-Footnote-156014339
Ref: Library<182>-Footnote-166014405
Ref: Library<182>-Footnote-176014471
Ref: Library<182>-Footnote-186014537
Ref: Library<182>-Footnote-196014603
Ref: Library<182>-Footnote-206014669
Ref: Library<182>-Footnote-216014735
Ref: Library<182>-Footnote-226014801
Ref: Library<182>-Footnote-236014867
Ref: Library<182>-Footnote-246014933
Node: Windows<70>6014999
Ref: whatsnew/changelog id9176015105
Ref: 1eed6015105
Ref: Windows<70>-Footnote-16015249
Node: Build<82>6015314
Ref: whatsnew/changelog id9186015417
Ref: 1eee6015417
Ref: Build<82>-Footnote-16015736
Ref: Build<82>-Footnote-26015801
Ref: Build<82>-Footnote-36015866
Node: Tests<71>6015931
Ref: whatsnew/changelog id9196016014
Ref: 1eef6016014
Ref: Tests<71>-Footnote-16016273
Ref: Tests<71>-Footnote-26016338
Node: Python 3 6 0 beta 26016403
Ref: whatsnew/changelog python-3-6-0-beta-26016524
Ref: 1ef06016524
Node: Core and Builtins<180>6016773
Ref: whatsnew/changelog id9206016872
Ref: 1ef16016872
Ref: Core and Builtins<180>-Footnote-16019611
Ref: Core and Builtins<180>-Footnote-26019676
Ref: Core and Builtins<180>-Footnote-36019741
Ref: Core and Builtins<180>-Footnote-46019806
Ref: Core and Builtins<180>-Footnote-56019871
Ref: Core and Builtins<180>-Footnote-66019936
Ref: Core and Builtins<180>-Footnote-76020001
Ref: Core and Builtins<180>-Footnote-86020066
Ref: Core and Builtins<180>-Footnote-96020131
Ref: Core and Builtins<180>-Footnote-106020196
Ref: Core and Builtins<180>-Footnote-116020262
Ref: Core and Builtins<180>-Footnote-126020328
Ref: Core and Builtins<180>-Footnote-136020394
Ref: Core and Builtins<180>-Footnote-146020460
Ref: Core and Builtins<180>-Footnote-156020526
Ref: Core and Builtins<180>-Footnote-166020592
Ref: Core and Builtins<180>-Footnote-176020658
Ref: Core and Builtins<180>-Footnote-186020724
Ref: Core and Builtins<180>-Footnote-196020790
Ref: Core and Builtins<180>-Footnote-206020856
Ref: Core and Builtins<180>-Footnote-216020922
Ref: Core and Builtins<180>-Footnote-226020988
Ref: Core and Builtins<180>-Footnote-236021054
Node: Library<183>6021120
Ref: whatsnew/changelog id9216021239
Ref: 1ef26021239
Ref: Library<183>-Footnote-16027027
Ref: Library<183>-Footnote-26027092
Ref: Library<183>-Footnote-36027157
Ref: Library<183>-Footnote-46027222
Ref: Library<183>-Footnote-56027287
Ref: Library<183>-Footnote-66027352
Ref: Library<183>-Footnote-76027417
Ref: Library<183>-Footnote-86027482
Ref: Library<183>-Footnote-96027547
Ref: Library<183>-Footnote-106027612
Ref: Library<183>-Footnote-116027678
Ref: Library<183>-Footnote-126027744
Ref: Library<183>-Footnote-136027810
Ref: Library<183>-Footnote-146027876
Ref: Library<183>-Footnote-156027942
Ref: Library<183>-Footnote-166028008
Ref: Library<183>-Footnote-176028074
Ref: Library<183>-Footnote-186028140
Ref: Library<183>-Footnote-196028206
Ref: Library<183>-Footnote-206028272
Ref: Library<183>-Footnote-216028338
Ref: Library<183>-Footnote-226028404
Ref: Library<183>-Footnote-236028470
Ref: Library<183>-Footnote-246028536
Ref: Library<183>-Footnote-256028602
Ref: Library<183>-Footnote-266028668
Ref: Library<183>-Footnote-276028734
Ref: Library<183>-Footnote-286028800
Ref: Library<183>-Footnote-296028866
Ref: Library<183>-Footnote-306028932
Ref: Library<183>-Footnote-316028998
Ref: Library<183>-Footnote-326029064
Ref: Library<183>-Footnote-336029130
Ref: Library<183>-Footnote-346029196
Ref: Library<183>-Footnote-356029262
Ref: Library<183>-Footnote-366029328
Ref: Library<183>-Footnote-376029394
Ref: Library<183>-Footnote-386029460
Ref: Library<183>-Footnote-396029526
Ref: Library<183>-Footnote-406029592
Ref: Library<183>-Footnote-416029658
Ref: Library<183>-Footnote-426029724
Ref: Library<183>-Footnote-436029790
Ref: Library<183>-Footnote-446029856
Ref: Library<183>-Footnote-456029922
Ref: Library<183>-Footnote-466029988
Ref: Library<183>-Footnote-476030054
Ref: Library<183>-Footnote-486030120
Node: Windows<71>6030186
Ref: whatsnew/changelog id9226030292
Ref: 1ef36030292
Ref: Windows<71>-Footnote-16031103
Ref: Windows<71>-Footnote-26031168
Ref: Windows<71>-Footnote-36031233
Ref: Windows<71>-Footnote-46031298
Ref: Windows<71>-Footnote-56031363
Ref: Windows<71>-Footnote-66031428
Ref: Windows<71>-Footnote-76031493
Ref: Windows<71>-Footnote-86031558
Ref: Windows<71>-Footnote-96031623
Ref: Windows<71>-Footnote-106031688
Node: C API<70>6031754
Ref: whatsnew/changelog id9236031857
Ref: 1ef46031857
Ref: C API<70>-Footnote-16032111
Node: Build<83>6032176
Ref: whatsnew/changelog id9246032277
Ref: 1ef56032277
Ref: Build<83>-Footnote-16032703
Ref: Build<83>-Footnote-26032768
Ref: Build<83>-Footnote-36032833
Node: Tests<72>6032898
Ref: whatsnew/changelog id9256032981
Ref: 1ef66032981
Ref: Tests<72>-Footnote-16033118
Node: Python 3 6 0 beta 16033183
Ref: whatsnew/changelog python-3-6-0-beta-16033305
Ref: 1ef76033305
Node: Core and Builtins<181>6033604
Ref: whatsnew/changelog id9266033703
Ref: 1ef86033703
Ref: Core and Builtins<181>-Footnote-16039894
Ref: Core and Builtins<181>-Footnote-26039959
Ref: Core and Builtins<181>-Footnote-36040024
Ref: Core and Builtins<181>-Footnote-46040089
Ref: Core and Builtins<181>-Footnote-56040131
Ref: Core and Builtins<181>-Footnote-66040196
Ref: Core and Builtins<181>-Footnote-76040261
Ref: Core and Builtins<181>-Footnote-86040326
Ref: Core and Builtins<181>-Footnote-96040391
Ref: Core and Builtins<181>-Footnote-106040456
Ref: Core and Builtins<181>-Footnote-116040522
Ref: Core and Builtins<181>-Footnote-126040588
Ref: Core and Builtins<181>-Footnote-136040654
Ref: Core and Builtins<181>-Footnote-146040697
Ref: Core and Builtins<181>-Footnote-156040763
Ref: Core and Builtins<181>-Footnote-166040829
Ref: Core and Builtins<181>-Footnote-176040872
Ref: Core and Builtins<181>-Footnote-186040938
Ref: Core and Builtins<181>-Footnote-196040981
Ref: Core and Builtins<181>-Footnote-206041047
Ref: Core and Builtins<181>-Footnote-216041113
Ref: Core and Builtins<181>-Footnote-226041179
Ref: Core and Builtins<181>-Footnote-236041245
Ref: Core and Builtins<181>-Footnote-246041311
Ref: Core and Builtins<181>-Footnote-256041377
Ref: Core and Builtins<181>-Footnote-266041443
Ref: Core and Builtins<181>-Footnote-276041509
Ref: Core and Builtins<181>-Footnote-286041552
Ref: Core and Builtins<181>-Footnote-296041618
Ref: Core and Builtins<181>-Footnote-306041684
Ref: Core and Builtins<181>-Footnote-316041750
Ref: Core and Builtins<181>-Footnote-326041816
Ref: Core and Builtins<181>-Footnote-336041882
Ref: Core and Builtins<181>-Footnote-346041948
Ref: Core and Builtins<181>-Footnote-356042014
Ref: Core and Builtins<181>-Footnote-366042080
Ref: Core and Builtins<181>-Footnote-376042146
Ref: Core and Builtins<181>-Footnote-386042212
Ref: Core and Builtins<181>-Footnote-396042278
Ref: Core and Builtins<181>-Footnote-406042344
Ref: Core and Builtins<181>-Footnote-416042410
Ref: Core and Builtins<181>-Footnote-426042476
Ref: Core and Builtins<181>-Footnote-436042542
Ref: Core and Builtins<181>-Footnote-446042608
Ref: Core and Builtins<181>-Footnote-456042674
Ref: Core and Builtins<181>-Footnote-466042740
Ref: Core and Builtins<181>-Footnote-476042783
Node: Library<184>6042849
Ref: whatsnew/changelog id9276042965
Ref: 1ef96042965
Ref: Library<184>-Footnote-16053943
Ref: Library<184>-Footnote-26054008
Ref: Library<184>-Footnote-36054073
Ref: Library<184>-Footnote-46054138
Ref: Library<184>-Footnote-56054203
Ref: Library<184>-Footnote-66054268
Ref: Library<184>-Footnote-76054333
Ref: Library<184>-Footnote-86054398
Ref: Library<184>-Footnote-96054463
Ref: Library<184>-Footnote-106054528
Ref: Library<184>-Footnote-116054594
Ref: Library<184>-Footnote-126054660
Ref: Library<184>-Footnote-136054726
Ref: Library<184>-Footnote-146054792
Ref: Library<184>-Footnote-156054858
Ref: Library<184>-Footnote-166054924
Ref: Library<184>-Footnote-176054990
Ref: Library<184>-Footnote-186055058
Ref: Library<184>-Footnote-196055124
Ref: Library<184>-Footnote-206055190
Ref: Library<184>-Footnote-216055256
Ref: Library<184>-Footnote-226055322
Ref: Library<184>-Footnote-236055388
Ref: Library<184>-Footnote-246055454
Ref: Library<184>-Footnote-256055520
Ref: Library<184>-Footnote-266055587
Ref: Library<184>-Footnote-276055653
Ref: Library<184>-Footnote-286055719
Ref: Library<184>-Footnote-296055785
Ref: Library<184>-Footnote-306055851
Ref: Library<184>-Footnote-316055917
Ref: Library<184>-Footnote-326055983
Ref: Library<184>-Footnote-336056049
Ref: Library<184>-Footnote-346056115
Ref: Library<184>-Footnote-356056181
Ref: Library<184>-Footnote-366056247
Ref: Library<184>-Footnote-376056313
Ref: Library<184>-Footnote-386056379
Ref: Library<184>-Footnote-396056445
Ref: Library<184>-Footnote-406056511
Ref: Library<184>-Footnote-416056577
Ref: Library<184>-Footnote-426056643
Ref: Library<184>-Footnote-436056686
Ref: Library<184>-Footnote-446056752
Ref: Library<184>-Footnote-456056795
Ref: Library<184>-Footnote-466056861
Ref: Library<184>-Footnote-476056927
Ref: Library<184>-Footnote-486056993
Ref: Library<184>-Footnote-496057059
Ref: Library<184>-Footnote-506057125
Ref: Library<184>-Footnote-516057191
Ref: Library<184>-Footnote-526057257
Ref: Library<184>-Footnote-536057323
Ref: Library<184>-Footnote-546057379
Ref: Library<184>-Footnote-556057445
Ref: Library<184>-Footnote-566057511
Ref: Library<184>-Footnote-576057577
Ref: Library<184>-Footnote-586057643
Ref: Library<184>-Footnote-596057709
Ref: Library<184>-Footnote-606057775
Ref: Library<184>-Footnote-616057841
Ref: Library<184>-Footnote-626057907
Ref: Library<184>-Footnote-636057973
Ref: Library<184>-Footnote-646058039
Ref: Library<184>-Footnote-656058105
Ref: Library<184>-Footnote-666058171
Ref: Library<184>-Footnote-676058237
Ref: Library<184>-Footnote-686058303
Ref: Library<184>-Footnote-696058369
Ref: Library<184>-Footnote-706058435
Ref: Library<184>-Footnote-716058501
Ref: Library<184>-Footnote-726058567
Ref: Library<184>-Footnote-736058633
Ref: Library<184>-Footnote-746058699
Ref: Library<184>-Footnote-756058765
Ref: Library<184>-Footnote-766058831
Ref: Library<184>-Footnote-776058896
Ref: Library<184>-Footnote-786058961
Ref: Library<184>-Footnote-796059027
Ref: Library<184>-Footnote-806059093
Ref: Library<184>-Footnote-816059158
Ref: Library<184>-Footnote-826059224
Node: IDLE<52>6059290
Ref: whatsnew/changelog id9286059393
Ref: 1efa6059393
Ref: IDLE<52>-Footnote-16060159
Ref: IDLE<52>-Footnote-26060224
Ref: IDLE<52>-Footnote-36060289
Ref: IDLE<52>-Footnote-46060354
Ref: IDLE<52>-Footnote-56060419
Ref: IDLE<52>-Footnote-66060484
Node: C API<71>6060549
Ref: whatsnew/changelog id9296060649
Ref: 1efb6060649
Ref: C API<71>-Footnote-16060921
Ref: C API<71>-Footnote-26060986
Node: Tests<73>6061051
Ref: whatsnew/changelog id9306061152
Ref: 1efc6061152
Ref: Tests<73>-Footnote-16061670
Ref: Tests<73>-Footnote-26061735
Ref: Tests<73>-Footnote-36061800
Ref: Tests<73>-Footnote-46061865
Node: Build<84>6061930
Ref: whatsnew/changelog id9316062037
Ref: 1efd6062037
Ref: Build<84>-Footnote-16063422
Ref: Build<84>-Footnote-26063487
Ref: Build<84>-Footnote-36063552
Ref: Build<84>-Footnote-46063617
Ref: Build<84>-Footnote-56063682
Ref: Build<84>-Footnote-66063747
Ref: Build<84>-Footnote-76063812
Ref: Build<84>-Footnote-86063877
Ref: Build<84>-Footnote-96063942
Ref: Build<84>-Footnote-106064007
Ref: Build<84>-Footnote-116064073
Node: Tools/Demos<51>6064139
Ref: whatsnew/changelog id9326064248
Ref: 1efe6064248
Ref: Tools/Demos<51>-Footnote-16064525
Node: Windows<72>6064590
Ref: whatsnew/changelog id9336064681
Ref: 1eff6064681
Ref: Windows<72>-Footnote-16065650
Ref: Windows<72>-Footnote-26065715
Ref: Windows<72>-Footnote-36065780
Ref: Windows<72>-Footnote-46065844
Ref: Windows<72>-Footnote-56065909
Ref: Windows<72>-Footnote-66065974
Ref: Windows<72>-Footnote-76066038
Ref: Windows<72>-Footnote-86066103
Ref: Windows<72>-Footnote-96066168
Ref: Windows<72>-Footnote-106066233
Ref: Windows<72>-Footnote-116066299
Node: Python 3 6 0 alpha 46066365
Ref: whatsnew/changelog python-3-6-0-alpha-46066488
Ref: 1f006066488
Node: Core and Builtins<182>6066737
Ref: whatsnew/changelog id9346066837
Ref: 1f016066837
Ref: Core and Builtins<182>-Footnote-16068789
Ref: Core and Builtins<182>-Footnote-26068854
Ref: Core and Builtins<182>-Footnote-36068919
Ref: Core and Builtins<182>-Footnote-46068984
Ref: Core and Builtins<182>-Footnote-56069049
Ref: Core and Builtins<182>-Footnote-66069114
Ref: Core and Builtins<182>-Footnote-76069179
Ref: Core and Builtins<182>-Footnote-86069244
Ref: Core and Builtins<182>-Footnote-96069309
Ref: Core and Builtins<182>-Footnote-106069373
Ref: Core and Builtins<182>-Footnote-116069439
Ref: Core and Builtins<182>-Footnote-126069505
Ref: Core and Builtins<182>-Footnote-136069571
Ref: Core and Builtins<182>-Footnote-146069637
Node: Library<185>6069680
Ref: whatsnew/changelog id9356069797
Ref: 1f026069797
Ref: Library<185>-Footnote-16074300
Ref: Library<185>-Footnote-26074365
Ref: Library<185>-Footnote-36074407
Ref: Library<185>-Footnote-46074472
Ref: Library<185>-Footnote-56074537
Ref: Library<185>-Footnote-66074602
Ref: Library<185>-Footnote-76074667
Ref: Library<185>-Footnote-86074732
Ref: Library<185>-Footnote-96074797
Ref: Library<185>-Footnote-106074862
Ref: Library<185>-Footnote-116074928
Ref: Library<185>-Footnote-126074971
Ref: Library<185>-Footnote-136075037
Ref: Library<185>-Footnote-146075103
Ref: Library<185>-Footnote-156075169
Ref: Library<185>-Footnote-166075235
Ref: Library<185>-Footnote-176075300
Ref: Library<185>-Footnote-186075366
Ref: Library<185>-Footnote-196075432
Ref: Library<185>-Footnote-206075498
Ref: Library<185>-Footnote-216075564
Ref: Library<185>-Footnote-226075630
Ref: Library<185>-Footnote-236075696
Ref: Library<185>-Footnote-246075762
Ref: Library<185>-Footnote-256075828
Ref: Library<185>-Footnote-266075894
Ref: Library<185>-Footnote-276075960
Ref: Library<185>-Footnote-286076026
Ref: Library<185>-Footnote-296076085
Ref: Library<185>-Footnote-306076150
Ref: Library<185>-Footnote-316076216
Ref: Library<185>-Footnote-326076282
Ref: Library<185>-Footnote-336076348
Ref: Library<185>-Footnote-346076391
Ref: Library<185>-Footnote-356076457
Ref: Library<185>-Footnote-366076522
Ref: Library<185>-Footnote-376076588
Ref: Library<185>-Footnote-386076654
Ref: Library<185>-Footnote-396076720
Node: IDLE<53>6076786
Ref: whatsnew/changelog id9366076890
Ref: 1f036076890
Ref: IDLE<53>-Footnote-16078214
Ref: IDLE<53>-Footnote-26078279
Ref: IDLE<53>-Footnote-36078344
Ref: IDLE<53>-Footnote-46078409
Ref: IDLE<53>-Footnote-56078474
Ref: IDLE<53>-Footnote-66078539
Ref: IDLE<53>-Footnote-76078604
Ref: IDLE<53>-Footnote-86078669
Node: Tests<74>6078734
Ref: whatsnew/changelog id9376078837
Ref: 1f046078837
Ref: Tests<74>-Footnote-16079426
Ref: Tests<74>-Footnote-26079491
Ref: Tests<74>-Footnote-36079556
Ref: Tests<74>-Footnote-46079621
Node: Windows<73>6079686
Ref: whatsnew/changelog id9386079790
Ref: 1f056079790
Ref: Windows<73>-Footnote-16080166
Ref: Windows<73>-Footnote-26080231
Ref: Windows<73>-Footnote-36080296
Ref: Windows<73>-Footnote-46080338
Ref: Windows<73>-Footnote-56080403
Node: Build<85>6080468
Ref: whatsnew/changelog id9396080554
Ref: 1f066080554
Ref: Build<85>-Footnote-16081455
Ref: Build<85>-Footnote-26081520
Ref: Build<85>-Footnote-36081585
Ref: Build<85>-Footnote-46081650
Ref: Build<85>-Footnote-56081715
Ref: Build<85>-Footnote-66081780
Node: Python 3 6 0 alpha 36081845
Ref: whatsnew/changelog python-3-6-0-alpha-36081969
Ref: 1f076081969
Node: Security<54>6082308
Ref: whatsnew/changelog id9406082408
Ref: 1f086082408
Ref: Security<54>-Footnote-16082786
Ref: Security<54>-Footnote-26082851
Node: Core and Builtins<183>6082916
Ref: whatsnew/changelog id9416083037
Ref: 1f096083037
Ref: Core and Builtins<183>-Footnote-16083786
Ref: Core and Builtins<183>-Footnote-26083851
Ref: Core and Builtins<183>-Footnote-36083916
Ref: Core and Builtins<183>-Footnote-46083981
Node: Library<186>6084046
Ref: whatsnew/changelog id9426084163
Ref: 1f0a6084163
Ref: Library<186>-Footnote-16088272
Ref: Library<186>-Footnote-26088337
Ref: Library<186>-Footnote-36088402
Ref: Library<186>-Footnote-46088467
Ref: Library<186>-Footnote-56088532
Ref: Library<186>-Footnote-66088597
Ref: Library<186>-Footnote-76088662
Ref: Library<186>-Footnote-86088727
Ref: Library<186>-Footnote-96088792
Ref: Library<186>-Footnote-106088857
Ref: Library<186>-Footnote-116088923
Ref: Library<186>-Footnote-126088989
Ref: Library<186>-Footnote-136089055
Ref: Library<186>-Footnote-146089121
Ref: Library<186>-Footnote-156089187
Ref: Library<186>-Footnote-166089253
Ref: Library<186>-Footnote-176089319
Ref: Library<186>-Footnote-186089385
Ref: Library<186>-Footnote-196089451
Ref: Library<186>-Footnote-206089517
Ref: Library<186>-Footnote-216089583
Ref: Library<186>-Footnote-226089626
Ref: Library<186>-Footnote-236089692
Ref: Library<186>-Footnote-246089758
Ref: Library<186>-Footnote-256089823
Ref: Library<186>-Footnote-266089889
Node: IDLE<54>6089955
Ref: whatsnew/changelog id9436090059
Ref: 1f0b6090059
Ref: IDLE<54>-Footnote-16091723
Ref: IDLE<54>-Footnote-26091788
Ref: IDLE<54>-Footnote-36091853
Ref: IDLE<54>-Footnote-46091918
Ref: IDLE<54>-Footnote-56091983
Ref: IDLE<54>-Footnote-66092048
Ref: IDLE<54>-Footnote-76092113
Ref: IDLE<54>-Footnote-86092178
Ref: IDLE<54>-Footnote-96092243
Ref: IDLE<54>-Footnote-106092308
Node: C API<72>6092374
Ref: whatsnew/changelog id9446092475
Ref: 1f0c6092475
Ref: C API<72>-Footnote-16092715
Node: Build<86>6092780
Ref: whatsnew/changelog id9456092888
Ref: 1f0d6092888
Ref: Build<86>-Footnote-16093865
Ref: Build<86>-Footnote-26093930
Ref: Build<86>-Footnote-36093995
Ref: Build<86>-Footnote-46094060
Ref: Build<86>-Footnote-56094125
Node: Tools/Demos<52>6094190
Ref: whatsnew/changelog id9466094306
Ref: 1f0e6094306
Ref: Tools/Demos<52>-Footnote-16094590
Ref: Tools/Demos<52>-Footnote-26094655
Node: Documentation<74>6094720
Ref: whatsnew/changelog id9476094836
Ref: 1f0f6094836
Ref: Documentation<74>-Footnote-16095215
Ref: Documentation<74>-Footnote-26095280
Node: Tests<75>6095345
Ref: whatsnew/changelog id9486095437
Ref: 1f106095437
Ref: Tests<75>-Footnote-16095605
Node: Python 3 6 0 alpha 26095670
Ref: whatsnew/changelog python-3-6-0-alpha-26095794
Ref: 1f116095794
Node: Security<55>6096157
Ref: whatsnew/changelog id9496096257
Ref: 1f126096257
Ref: Security<55>-Footnote-16096748
Ref: Security<55>-Footnote-26096813
Ref: Security<55>-Footnote-36096868
Ref: Security<55>-Footnote-46096923
Node: Core and Builtins<184>6096988
Ref: whatsnew/changelog id9506097109
Ref: 1f136097109
Ref: Core and Builtins<184>-Footnote-16098741
Ref: Core and Builtins<184>-Footnote-26098806
Ref: Core and Builtins<184>-Footnote-36098871
Ref: Core and Builtins<184>-Footnote-46098936
Ref: Core and Builtins<184>-Footnote-56099001
Ref: Core and Builtins<184>-Footnote-66099066
Ref: Core and Builtins<184>-Footnote-76099108
Ref: Core and Builtins<184>-Footnote-86099173
Ref: Core and Builtins<184>-Footnote-96099238
Ref: Core and Builtins<184>-Footnote-106099303
Ref: Core and Builtins<184>-Footnote-116099369
Ref: Core and Builtins<184>-Footnote-126099435
Node: Library<187>6099501
Ref: whatsnew/changelog id9516099618
Ref: 1f146099618
Ref: Library<187>-Footnote-16104827
Ref: Library<187>-Footnote-26104892
Ref: Library<187>-Footnote-36104957
Ref: Library<187>-Footnote-46105022
Ref: Library<187>-Footnote-56105087
Ref: Library<187>-Footnote-66105152
Ref: Library<187>-Footnote-76105217
Ref: Library<187>-Footnote-86105282
Ref: Library<187>-Footnote-96105347
Ref: Library<187>-Footnote-106105389
Ref: Library<187>-Footnote-116105455
Ref: Library<187>-Footnote-126105521
Ref: Library<187>-Footnote-136105587
Ref: Library<187>-Footnote-146105630
Ref: Library<187>-Footnote-156105696
Ref: Library<187>-Footnote-166105739
Ref: Library<187>-Footnote-176105782
Ref: Library<187>-Footnote-186105848
Ref: Library<187>-Footnote-196105914
Ref: Library<187>-Footnote-206105980
Ref: Library<187>-Footnote-216106046
Ref: Library<187>-Footnote-226106112
Ref: Library<187>-Footnote-236106178
Ref: Library<187>-Footnote-246106244
Ref: Library<187>-Footnote-256106310
Ref: Library<187>-Footnote-266106376
Ref: Library<187>-Footnote-276106442
Ref: Library<187>-Footnote-286106508
Ref: Library<187>-Footnote-296106574
Ref: Library<187>-Footnote-306106640
Ref: Library<187>-Footnote-316106706
Ref: Library<187>-Footnote-326106772
Ref: Library<187>-Footnote-336106838
Ref: Library<187>-Footnote-346106904
Ref: Library<187>-Footnote-356106970
Node: IDLE<55>6107036
Ref: whatsnew/changelog id9526107148
Ref: 1f156107148
Ref: IDLE<55>-Footnote-16109801
Ref: IDLE<55>-Footnote-26109865
Ref: IDLE<55>-Footnote-36109930
Ref: IDLE<55>-Footnote-46109995
Ref: IDLE<55>-Footnote-56110060
Ref: IDLE<55>-Footnote-66110125
Ref: IDLE<55>-Footnote-76110190
Ref: IDLE<55>-Footnote-86110255
Ref: IDLE<55>-Footnote-96110320
Ref: IDLE<55>-Footnote-106110385
Ref: IDLE<55>-Footnote-116110451
Ref: IDLE<55>-Footnote-126110517
Ref: IDLE<55>-Footnote-136110583
Ref: IDLE<55>-Footnote-146110649
Ref: IDLE<55>-Footnote-156110715
Ref: IDLE<55>-Footnote-166110781
Ref: IDLE<55>-Footnote-176110847
Ref: IDLE<55>-Footnote-186110913
Ref: IDLE<55>-Footnote-196110979
Node: Documentation<75>6111045
Ref: whatsnew/changelog id9536111154
Ref: 1f166111154
Ref: Documentation<75>-Footnote-16111599
Ref: Documentation<75>-Footnote-26111664
Ref: Documentation<75>-Footnote-36111729
Ref: Documentation<75>-Footnote-46111771
Node: Tests<76>6111836
Ref: whatsnew/changelog id9546111948
Ref: 1f176111948
Ref: Tests<76>-Footnote-16112328
Ref: Tests<76>-Footnote-26112393
Node: Windows<74>6112458
Ref: whatsnew/changelog id9556112562
Ref: 1f186112562
Ref: Windows<74>-Footnote-16112972
Ref: Windows<74>-Footnote-26113037
Node: Build<87>6113102
Ref: whatsnew/changelog id9566113206
Ref: 1f196113206
Ref: Build<87>-Footnote-16113483
Ref: Build<87>-Footnote-26113548
Node: C API<73>6113613
Ref: whatsnew/changelog id9576113721
Ref: 1f1a6113721
Ref: C API<73>-Footnote-16113959
Ref: C API<73>-Footnote-26114024
Ref: C API<73>-Footnote-36114066
Node: Tools/Demos<53>6114131
Ref: whatsnew/changelog id9586114221
Ref: 1f1b6114221
Ref: Tools/Demos<53>-Footnote-16114419
Node: Python 3 6 0 alpha 16114484
Ref: whatsnew/changelog python-3-6-0-alpha-16114606
Ref: 1f1c6114606
Node: Security<56>6114969
Ref: whatsnew/changelog id9596115069
Ref: 1f1d6115069
Ref: Security<56>-Footnote-16115560
Ref: Security<56>-Footnote-26115625
Ref: Security<56>-Footnote-36115690
Node: Core and Builtins<185>6115755
Ref: whatsnew/changelog id9606115876
Ref: 1f1e6115876
Ref: Core and Builtins<185>-Footnote-16129059
Ref: Core and Builtins<185>-Footnote-26129124
Ref: Core and Builtins<185>-Footnote-36129189
Ref: Core and Builtins<185>-Footnote-46129254
Ref: Core and Builtins<185>-Footnote-56129319
Ref: Core and Builtins<185>-Footnote-66129384
Ref: Core and Builtins<185>-Footnote-76129449
Ref: Core and Builtins<185>-Footnote-86129514
Ref: Core and Builtins<185>-Footnote-96129579
Ref: Core and Builtins<185>-Footnote-106129644
Ref: Core and Builtins<185>-Footnote-116129710
Ref: Core and Builtins<185>-Footnote-126129776
Ref: Core and Builtins<185>-Footnote-136129842
Ref: Core and Builtins<185>-Footnote-146129908
Ref: Core and Builtins<185>-Footnote-156129974
Ref: Core and Builtins<185>-Footnote-166130040
Ref: Core and Builtins<185>-Footnote-176130083
Ref: Core and Builtins<185>-Footnote-186130149
Ref: Core and Builtins<185>-Footnote-196130215
Ref: Core and Builtins<185>-Footnote-206130281
Ref: Core and Builtins<185>-Footnote-216130347
Ref: Core and Builtins<185>-Footnote-226130413
Ref: Core and Builtins<185>-Footnote-236130479
Ref: Core and Builtins<185>-Footnote-246130522
Ref: Core and Builtins<185>-Footnote-256130588
Ref: Core and Builtins<185>-Footnote-266130654
Ref: Core and Builtins<185>-Footnote-276130720
Ref: Core and Builtins<185>-Footnote-286130786
Ref: Core and Builtins<185>-Footnote-296130852
Ref: Core and Builtins<185>-Footnote-306130918
Ref: Core and Builtins<185>-Footnote-316130984
Ref: Core and Builtins<185>-Footnote-326131050
Ref: Core and Builtins<185>-Footnote-336131116
Ref: Core and Builtins<185>-Footnote-346131182
Ref: Core and Builtins<185>-Footnote-356131248
Ref: Core and Builtins<185>-Footnote-366131314
Ref: Core and Builtins<185>-Footnote-376131379
Ref: Core and Builtins<185>-Footnote-386131445
Ref: Core and Builtins<185>-Footnote-396131511
Ref: Core and Builtins<185>-Footnote-406131577
Ref: Core and Builtins<185>-Footnote-416131643
Ref: Core and Builtins<185>-Footnote-426131709
Ref: Core and Builtins<185>-Footnote-436131775
Ref: Core and Builtins<185>-Footnote-446131841
Ref: Core and Builtins<185>-Footnote-456131907
Ref: Core and Builtins<185>-Footnote-466131973
Ref: Core and Builtins<185>-Footnote-476132039
Ref: Core and Builtins<185>-Footnote-486132105
Ref: Core and Builtins<185>-Footnote-496132171
Ref: Core and Builtins<185>-Footnote-506132237
Ref: Core and Builtins<185>-Footnote-516132303
Ref: Core and Builtins<185>-Footnote-526132369
Ref: Core and Builtins<185>-Footnote-536132434
Ref: Core and Builtins<185>-Footnote-546132500
Ref: Core and Builtins<185>-Footnote-556132566
Ref: Core and Builtins<185>-Footnote-566132632
Ref: Core and Builtins<185>-Footnote-576132698
Ref: Core and Builtins<185>-Footnote-586132764
Ref: Core and Builtins<185>-Footnote-596132830
Ref: Core and Builtins<185>-Footnote-606132896
Ref: Core and Builtins<185>-Footnote-616132962
Ref: Core and Builtins<185>-Footnote-626133028
Ref: Core and Builtins<185>-Footnote-636133094
Ref: Core and Builtins<185>-Footnote-646133160
Ref: Core and Builtins<185>-Footnote-656133226
Ref: Core and Builtins<185>-Footnote-666133292
Ref: Core and Builtins<185>-Footnote-676133358
Ref: Core and Builtins<185>-Footnote-686133424
Ref: Core and Builtins<185>-Footnote-696133490
Ref: Core and Builtins<185>-Footnote-706133556
Ref: Core and Builtins<185>-Footnote-716133622
Ref: Core and Builtins<185>-Footnote-726133688
Ref: Core and Builtins<185>-Footnote-736133754
Ref: Core and Builtins<185>-Footnote-746133820
Ref: Core and Builtins<185>-Footnote-756133886
Ref: Core and Builtins<185>-Footnote-766133952
Ref: Core and Builtins<185>-Footnote-776134018
Ref: Core and Builtins<185>-Footnote-786134084
Ref: Core and Builtins<185>-Footnote-796134149
Ref: Core and Builtins<185>-Footnote-806134215
Ref: Core and Builtins<185>-Footnote-816134258
Ref: Core and Builtins<185>-Footnote-826134324
Ref: Core and Builtins<185>-Footnote-836134390
Ref: Core and Builtins<185>-Footnote-846134456
Ref: Core and Builtins<185>-Footnote-856134522
Ref: Core and Builtins<185>-Footnote-866134588
Ref: Core and Builtins<185>-Footnote-876134654
Node: Library<188>6134720
Ref: whatsnew/changelog id9616134837
Ref: 1f206134837
Ref: Library<188>-Footnote-16165871
Ref: Library<188>-Footnote-26165936
Ref: Library<188>-Footnote-36166001
Ref: Library<188>-Footnote-46166066
Ref: Library<188>-Footnote-56166131
Ref: Library<188>-Footnote-66166196
Ref: Library<188>-Footnote-76166261
Ref: Library<188>-Footnote-86166326
Ref: Library<188>-Footnote-96166391
Ref: Library<188>-Footnote-106166456
Ref: Library<188>-Footnote-116166522
Ref: Library<188>-Footnote-126166588
Ref: Library<188>-Footnote-136166654
Ref: Library<188>-Footnote-146166720
Ref: Library<188>-Footnote-156166786
Ref: Library<188>-Footnote-166166852
Ref: Library<188>-Footnote-176166918
Ref: Library<188>-Footnote-186166984
Ref: Library<188>-Footnote-196167027
Ref: Library<188>-Footnote-206167093
Ref: Library<188>-Footnote-216167159
Ref: Library<188>-Footnote-226167225
Ref: Library<188>-Footnote-236167291
Ref: Library<188>-Footnote-246167357
Ref: Library<188>-Footnote-256167423
Ref: Library<188>-Footnote-266167489
Ref: Library<188>-Footnote-276167555
Ref: Library<188>-Footnote-286167621
Ref: Library<188>-Footnote-296167687
Ref: Library<188>-Footnote-306167753
Ref: Library<188>-Footnote-316167819
Ref: Library<188>-Footnote-326167885
Ref: Library<188>-Footnote-336167951
Ref: Library<188>-Footnote-346168017
Ref: Library<188>-Footnote-356168083
Ref: Library<188>-Footnote-366168149
Ref: Library<188>-Footnote-376168215
Ref: Library<188>-Footnote-386168281
Ref: Library<188>-Footnote-396168347
Ref: Library<188>-Footnote-406168413
Ref: Library<188>-Footnote-416168479
Ref: Library<188>-Footnote-426168545
Ref: Library<188>-Footnote-436168611
Ref: Library<188>-Footnote-446168677
Ref: Library<188>-Footnote-456168743
Ref: Library<188>-Footnote-466168809
Ref: Library<188>-Footnote-476168875
Ref: Library<188>-Footnote-486168941
Ref: Library<188>-Footnote-496169007
Ref: Library<188>-Footnote-506169073
Ref: Library<188>-Footnote-516169139
Ref: Library<188>-Footnote-526169205
Ref: Library<188>-Footnote-536169271
Ref: Library<188>-Footnote-546169337
Ref: Library<188>-Footnote-556169403
Ref: Library<188>-Footnote-566169469
Ref: Library<188>-Footnote-576169535
Ref: Library<188>-Footnote-586169601
Ref: Library<188>-Footnote-596169667
Ref: Library<188>-Footnote-606169733
Ref: Library<188>-Footnote-616169799
Ref: Library<188>-Footnote-626169865
Ref: Library<188>-Footnote-636169931
Ref: Library<188>-Footnote-646169997
Ref: Library<188>-Footnote-656170063
Ref: Library<188>-Footnote-666170129
Ref: Library<188>-Footnote-676170195
Ref: Library<188>-Footnote-686170261
Ref: Library<188>-Footnote-696170327
Ref: Library<188>-Footnote-706170393
Ref: Library<188>-Footnote-716170459
Ref: Library<188>-Footnote-726170525
Ref: Library<188>-Footnote-736170591
Ref: Library<188>-Footnote-746170657
Ref: Library<188>-Footnote-756170723
Ref: Library<188>-Footnote-766170789
Ref: Library<188>-Footnote-776170855
Ref: Library<188>-Footnote-786170921
Ref: Library<188>-Footnote-796170987
Ref: Library<188>-Footnote-806171053
Ref: Library<188>-Footnote-816171118
Ref: Library<188>-Footnote-826171184
Ref: Library<188>-Footnote-836171250
Ref: Library<188>-Footnote-846171316
Ref: Library<188>-Footnote-856171382
Ref: Library<188>-Footnote-866171448
Ref: Library<188>-Footnote-876171514
Ref: Library<188>-Footnote-886171580
Ref: Library<188>-Footnote-896171646
Ref: Library<188>-Footnote-906171712
Ref: Library<188>-Footnote-916171778
Ref: Library<188>-Footnote-926171844
Ref: Library<188>-Footnote-936171910
Ref: Library<188>-Footnote-946171976
Ref: Library<188>-Footnote-956172042
Ref: Library<188>-Footnote-966172108
Ref: Library<188>-Footnote-976172174
Ref: Library<188>-Footnote-986172240
Ref: Library<188>-Footnote-996172306
Ref: Library<188>-Footnote-1006172372
Ref: Library<188>-Footnote-1016172439
Ref: Library<188>-Footnote-1026172506
Ref: Library<188>-Footnote-1036172573
Ref: Library<188>-Footnote-1046172640
Ref: Library<188>-Footnote-1056172707
Ref: Library<188>-Footnote-1066172774
Ref: Library<188>-Footnote-1076172841
Ref: Library<188>-Footnote-1086172908
Ref: Library<188>-Footnote-1096172975
Ref: Library<188>-Footnote-1106173042
Ref: Library<188>-Footnote-1116173109
Ref: Library<188>-Footnote-1126173176
Ref: Library<188>-Footnote-1136173243
Ref: Library<188>-Footnote-1146173310
Ref: Library<188>-Footnote-1156173377
Ref: Library<188>-Footnote-1166173444
Ref: Library<188>-Footnote-1176173511
Ref: Library<188>-Footnote-1186173578
Ref: Library<188>-Footnote-1196173645
Ref: Library<188>-Footnote-1206173712
Ref: Library<188>-Footnote-1216173779
Ref: Library<188>-Footnote-1226173846
Ref: Library<188>-Footnote-1236173913
Ref: Library<188>-Footnote-1246173980
Ref: Library<188>-Footnote-1256174047
Ref: Library<188>-Footnote-1266174114
Ref: Library<188>-Footnote-1276174181
Ref: Library<188>-Footnote-1286174248
Ref: Library<188>-Footnote-1296174315
Ref: Library<188>-Footnote-1306174382
Ref: Library<188>-Footnote-1316174449
Ref: Library<188>-Footnote-1326174516
Ref: Library<188>-Footnote-1336174583
Ref: Library<188>-Footnote-1346174650
Ref: Library<188>-Footnote-1356174717
Ref: Library<188>-Footnote-1366174784
Ref: Library<188>-Footnote-1376174851
Ref: Library<188>-Footnote-1386174918
Ref: Library<188>-Footnote-1396174985
Ref: Library<188>-Footnote-1406175052
Ref: Library<188>-Footnote-1416175119
Ref: Library<188>-Footnote-1426175186
Ref: Library<188>-Footnote-1436175253
Ref: Library<188>-Footnote-1446175320
Ref: Library<188>-Footnote-1456175386
Ref: Library<188>-Footnote-1466175453
Ref: Library<188>-Footnote-1476175520
Ref: Library<188>-Footnote-1486175587
Ref: Library<188>-Footnote-1496175654
Ref: Library<188>-Footnote-1506175721
Ref: Library<188>-Footnote-1516175787
Ref: Library<188>-Footnote-1526175854
Ref: Library<188>-Footnote-1536175921
Ref: Library<188>-Footnote-1546175988
Ref: Library<188>-Footnote-1556176055
Ref: Library<188>-Footnote-1566176122
Ref: Library<188>-Footnote-1576176189
Ref: Library<188>-Footnote-1586176256
Ref: Library<188>-Footnote-1596176323
Ref: Library<188>-Footnote-1606176390
Ref: Library<188>-Footnote-1616176456
Ref: Library<188>-Footnote-1626176523
Ref: Library<188>-Footnote-1636176590
Ref: Library<188>-Footnote-1646176657
Ref: Library<188>-Footnote-1656176724
Ref: Library<188>-Footnote-1666176791
Ref: Library<188>-Footnote-1676176858
Ref: Library<188>-Footnote-1686176925
Ref: Library<188>-Footnote-1696176992
Ref: Library<188>-Footnote-1706177059
Ref: Library<188>-Footnote-1716177126
Ref: Library<188>-Footnote-1726177193
Ref: Library<188>-Footnote-1736177260
Ref: Library<188>-Footnote-1746177327
Ref: Library<188>-Footnote-1756177394
Ref: Library<188>-Footnote-1766177461
Ref: Library<188>-Footnote-1776177528
Ref: Library<188>-Footnote-1786177595
Ref: Library<188>-Footnote-1796177662
Ref: Library<188>-Footnote-1806177729
Ref: Library<188>-Footnote-1816177796
Ref: Library<188>-Footnote-1826177863
Ref: Library<188>-Footnote-1836177930
Ref: Library<188>-Footnote-1846177997
Ref: Library<188>-Footnote-1856178064
Ref: Library<188>-Footnote-1866178131
Ref: Library<188>-Footnote-1876178198
Ref: Library<188>-Footnote-1886178265
Ref: Library<188>-Footnote-1896178332
Ref: Library<188>-Footnote-1906178399
Ref: Library<188>-Footnote-1916178466
Ref: Library<188>-Footnote-1926178533
Ref: Library<188>-Footnote-1936178600
Ref: Library<188>-Footnote-1946178667
Ref: Library<188>-Footnote-1956178734
Ref: Library<188>-Footnote-1966178801
Ref: Library<188>-Footnote-1976178868
Ref: Library<188>-Footnote-1986178935
Ref: Library<188>-Footnote-1996179002
Ref: Library<188>-Footnote-2006179069
Ref: Library<188>-Footnote-2016179136
Ref: Library<188>-Footnote-2026179203
Ref: Library<188>-Footnote-2036179270
Ref: Library<188>-Footnote-2046179337
Ref: Library<188>-Footnote-2056179404
Ref: Library<188>-Footnote-2066179471
Ref: Library<188>-Footnote-2076179538
Ref: Library<188>-Footnote-2086179605
Ref: Library<188>-Footnote-2096179671
Ref: Library<188>-Footnote-2106179737
Ref: Library<188>-Footnote-2116179804
Ref: Library<188>-Footnote-2126179871
Ref: Library<188>-Footnote-2136179938
Ref: Library<188>-Footnote-2146180005
Ref: Library<188>-Footnote-2156180072
Ref: Library<188>-Footnote-2166180139
Ref: Library<188>-Footnote-2176180206
Ref: Library<188>-Footnote-2186180273
Ref: Library<188>-Footnote-2196180340
Ref: Library<188>-Footnote-2206180407
Ref: Library<188>-Footnote-2216180474
Ref: Library<188>-Footnote-2226180541
Ref: Library<188>-Footnote-2236180608
Ref: Library<188>-Footnote-2246180675
Node: IDLE<56>6180742
Ref: whatsnew/changelog id9626180854
Ref: 1f226180854
Ref: IDLE<56>-Footnote-16186433
Ref: IDLE<56>-Footnote-26186498
Ref: IDLE<56>-Footnote-36186563
Ref: IDLE<56>-Footnote-46186628
Ref: IDLE<56>-Footnote-56186693
Ref: IDLE<56>-Footnote-66186758
Ref: IDLE<56>-Footnote-76186823
Ref: IDLE<56>-Footnote-86186888
Ref: IDLE<56>-Footnote-96186953
Ref: IDLE<56>-Footnote-106187018
Ref: IDLE<56>-Footnote-116187084
Ref: IDLE<56>-Footnote-126187150
Ref: IDLE<56>-Footnote-136187216
Ref: IDLE<56>-Footnote-146187282
Ref: IDLE<56>-Footnote-156187348
Ref: IDLE<56>-Footnote-166187414
Ref: IDLE<56>-Footnote-176187480
Ref: IDLE<56>-Footnote-186187546
Ref: IDLE<56>-Footnote-196187612
Ref: IDLE<56>-Footnote-206187678
Ref: IDLE<56>-Footnote-216187744
Ref: IDLE<56>-Footnote-226187810
Ref: IDLE<56>-Footnote-236187876
Ref: IDLE<56>-Footnote-246187942
Ref: IDLE<56>-Footnote-256188008
Ref: IDLE<56>-Footnote-266188074
Ref: IDLE<56>-Footnote-276188140
Ref: IDLE<56>-Footnote-286188206
Node: Documentation<76>6188272
Ref: whatsnew/changelog id9636188381
Ref: 1f236188381
Ref: Documentation<76>-Footnote-16189171
Ref: Documentation<76>-Footnote-26189236
Ref: Documentation<76>-Footnote-36189300
Ref: Documentation<76>-Footnote-46189365
Ref: Documentation<76>-Footnote-56189430
Node: Tests<77>6189495
Ref: whatsnew/changelog id9646189605
Ref: 1f246189605
Ref: Tests<77>-Footnote-16191357
Ref: Tests<77>-Footnote-26191422
Ref: Tests<77>-Footnote-36191487
Ref: Tests<77>-Footnote-46191552
Ref: Tests<77>-Footnote-56191617
Ref: Tests<77>-Footnote-66191682
Ref: Tests<77>-Footnote-76191747
Ref: Tests<77>-Footnote-86191812
Ref: Tests<77>-Footnote-96191877
Ref: Tests<77>-Footnote-106191942
Ref: Tests<77>-Footnote-116192008
Ref: Tests<77>-Footnote-126192074
Ref: Tests<77>-Footnote-136192140
Node: Build<88>6192206
Ref: whatsnew/changelog id9656192310
Ref: 1f256192310
Ref: Build<88>-Footnote-16195040
Ref: Build<88>-Footnote-26195105
Ref: Build<88>-Footnote-36195170
Ref: Build<88>-Footnote-46195235
Ref: Build<88>-Footnote-56195300
Ref: Build<88>-Footnote-66195365
Ref: Build<88>-Footnote-76195430
Ref: Build<88>-Footnote-86195495
Ref: Build<88>-Footnote-96195560
Ref: Build<88>-Footnote-106195625
Ref: Build<88>-Footnote-116195691
Ref: Build<88>-Footnote-126195757
Ref: Build<88>-Footnote-136195823
Ref: Build<88>-Footnote-146195889
Ref: Build<88>-Footnote-156195955
Ref: Build<88>-Footnote-166196021
Ref: Build<88>-Footnote-176196087
Ref: Build<88>-Footnote-186196153
Ref: Build<88>-Footnote-196196219
Node: Windows<75>6196285
Ref: whatsnew/changelog id9666196395
Ref: 1f266196395
Ref: Windows<75>-Footnote-16197043
Ref: Windows<75>-Footnote-26197108
Ref: Windows<75>-Footnote-36197173
Ref: Windows<75>-Footnote-46197238
Ref: Windows<75>-Footnote-56197303
Ref: Windows<75>-Footnote-66197368
Node: Tools/Demos<54>6197433
Ref: whatsnew/changelog id9676197543
Ref: 1f276197543
Ref: Tools/Demos<54>-Footnote-16198333
Ref: Tools/Demos<54>-Footnote-26198398
Ref: Tools/Demos<54>-Footnote-36198463
Ref: Tools/Demos<54>-Footnote-46198528
Ref: Tools/Demos<54>-Footnote-56198593
Ref: Tools/Demos<54>-Footnote-66198658
Node: C API<74>6198723
Ref: whatsnew/changelog id9686198813
Ref: 1f286198813
Ref: C API<74>-Footnote-16199306
Ref: C API<74>-Footnote-26199371
Node: Python 3 5 5 final6199436
Ref: whatsnew/changelog python-3-5-5-final6199570
Ref: 1f296199570
Node: Python 3 5 5 release candidate 16199698
Ref: whatsnew/changelog python-3-5-5-release-candidate-16199830
Ref: 1f2a6199830
Node: Security<57>6200047
Ref: whatsnew/changelog id9696200159
Ref: 1f2b6200159
Ref: Security<57>-Footnote-16201430
Ref: Security<57>-Footnote-26201495
Ref: Security<57>-Footnote-36201560
Ref: Security<57>-Footnote-46201625
Ref: Security<57>-Footnote-56201690
Ref: Security<57>-Footnote-66201748
Node: Core and Builtins<186>6201813
Ref: whatsnew/changelog id9706201946
Ref: 1f2c6201946
Ref: Core and Builtins<186>-Footnote-16202171
Node: Library<189>6202236
Ref: whatsnew/changelog id9716202348
Ref: 1f2d6202348
Ref: Library<189>-Footnote-16202875
Ref: Library<189>-Footnote-26202940
Node: Python 3 5 4 final6203005
Ref: whatsnew/changelog python-3-5-4-final6203151
Ref: 1f2e6203151
Node: Library<190>6203269
Ref: whatsnew/changelog id9726203336
Ref: 1f2f6203336
Ref: Library<190>-Footnote-16203534
Node: Python 3 5 4 release candidate 16203599
Ref: whatsnew/changelog python-3-5-4-release-candidate-16203731
Ref: 1f306203731
Node: Security<58>6204070
Ref: whatsnew/changelog id9736204182
Ref: 1f316204182
Ref: Security<58>-Footnote-16205510
Ref: Security<58>-Footnote-26205575
Ref: Security<58>-Footnote-36205640
Ref: Security<58>-Footnote-46205695
Ref: Security<58>-Footnote-56205750
Ref: Security<58>-Footnote-66205805
Ref: Security<58>-Footnote-76205860
Ref: Security<58>-Footnote-86205915
Ref: Security<58>-Footnote-96205970
Ref: Security<58>-Footnote-106206035
Ref: Security<58>-Footnote-116206101
Ref: Security<58>-Footnote-126206157
Node: Core and Builtins<187>6206213
Ref: whatsnew/changelog id9746206346
Ref: 1f326206346
Ref: Core and Builtins<187>-Footnote-16208603
Ref: Core and Builtins<187>-Footnote-26208668
Ref: Core and Builtins<187>-Footnote-36208733
Ref: Core and Builtins<187>-Footnote-46208798
Ref: Core and Builtins<187>-Footnote-56208863
Ref: Core and Builtins<187>-Footnote-66208928
Ref: Core and Builtins<187>-Footnote-76208993
Ref: Core and Builtins<187>-Footnote-86209058
Ref: Core and Builtins<187>-Footnote-96209123
Ref: Core and Builtins<187>-Footnote-106209188
Ref: Core and Builtins<187>-Footnote-116209254
Ref: Core and Builtins<187>-Footnote-126209320
Ref: Core and Builtins<187>-Footnote-136209386
Ref: Core and Builtins<187>-Footnote-146209452
Ref: Core and Builtins<187>-Footnote-156209518
Node: Library<191>6209584
Ref: whatsnew/changelog id9756209722
Ref: 1f336209722
Ref: Library<191>-Footnote-16219919
Ref: Library<191>-Footnote-26219984
Ref: Library<191>-Footnote-36220049
Ref: Library<191>-Footnote-46220114
Ref: Library<191>-Footnote-56220179
Ref: Library<191>-Footnote-66220244
Ref: Library<191>-Footnote-76220309
Ref: Library<191>-Footnote-86220374
Ref: Library<191>-Footnote-96220439
Ref: Library<191>-Footnote-106220504
Ref: Library<191>-Footnote-116220570
Ref: Library<191>-Footnote-126220636
Ref: Library<191>-Footnote-136220702
Ref: Library<191>-Footnote-146220768
Ref: Library<191>-Footnote-156220834
Ref: Library<191>-Footnote-166220900
Ref: Library<191>-Footnote-176220966
Ref: Library<191>-Footnote-186221032
Ref: Library<191>-Footnote-196221098
Ref: Library<191>-Footnote-206221164
Ref: Library<191>-Footnote-216221230
Ref: Library<191>-Footnote-226221296
Ref: Library<191>-Footnote-236221362
Ref: Library<191>-Footnote-246221428
Ref: Library<191>-Footnote-256221494
Ref: Library<191>-Footnote-266221560
Ref: Library<191>-Footnote-276221626
Ref: Library<191>-Footnote-286221692
Ref: Library<191>-Footnote-296221758
Ref: Library<191>-Footnote-306221824
Ref: Library<191>-Footnote-316221890
Ref: Library<191>-Footnote-326221956
Ref: Library<191>-Footnote-336222022
Ref: Library<191>-Footnote-346222088
Ref: Library<191>-Footnote-356222154
Ref: Library<191>-Footnote-366222220
Ref: Library<191>-Footnote-376222286
Ref: Library<191>-Footnote-386222352
Ref: Library<191>-Footnote-396222418
Ref: Library<191>-Footnote-406222484
Ref: Library<191>-Footnote-416222550
Ref: Library<191>-Footnote-426222616
Ref: Library<191>-Footnote-436222682
Ref: Library<191>-Footnote-446222748
Ref: Library<191>-Footnote-456222814
Ref: Library<191>-Footnote-466222880
Ref: Library<191>-Footnote-476222946
Ref: Library<191>-Footnote-486223012
Ref: Library<191>-Footnote-496223078
Ref: Library<191>-Footnote-506223144
Ref: Library<191>-Footnote-516223210
Ref: Library<191>-Footnote-526223276
Ref: Library<191>-Footnote-536223342
Ref: Library<191>-Footnote-546223408
Ref: Library<191>-Footnote-556223473
Ref: Library<191>-Footnote-566223539
Ref: Library<191>-Footnote-576223605
Ref: Library<191>-Footnote-586223671
Ref: Library<191>-Footnote-596223737
Ref: Library<191>-Footnote-606223803
Ref: Library<191>-Footnote-616223869
Ref: Library<191>-Footnote-626223935
Ref: Library<191>-Footnote-636224001
Ref: Library<191>-Footnote-646224067
Ref: Library<191>-Footnote-656224133
Ref: Library<191>-Footnote-666224199
Ref: Library<191>-Footnote-676224265
Ref: Library<191>-Footnote-686224331
Ref: Library<191>-Footnote-696224397
Ref: Library<191>-Footnote-706224463
Ref: Library<191>-Footnote-716224529
Ref: Library<191>-Footnote-726224595
Ref: Library<191>-Footnote-736224661
Ref: Library<191>-Footnote-746224727
Node: Documentation<77>6224793
Ref: whatsnew/changelog id9766224918
Ref: 1f346224918
Ref: Documentation<77>-Footnote-16225630
Ref: Documentation<77>-Footnote-26225695
Ref: Documentation<77>-Footnote-36225760
Ref: Documentation<77>-Footnote-46225825
Ref: Documentation<77>-Footnote-56225890
Ref: Documentation<77>-Footnote-66225955
Node: Tests<78>6226020
Ref: whatsnew/changelog id9776226142
Ref: 1f356226142
Ref: Tests<78>-Footnote-16228247
Ref: Tests<78>-Footnote-26228312
Ref: Tests<78>-Footnote-36228377
Ref: Tests<78>-Footnote-46228442
Ref: Tests<78>-Footnote-56228507
Ref: Tests<78>-Footnote-66228572
Ref: Tests<78>-Footnote-76228637
Ref: Tests<78>-Footnote-86228702
Ref: Tests<78>-Footnote-96228767
Node: Build<89>6228832
Ref: whatsnew/changelog id9786228948
Ref: 1f366228948
Ref: Build<89>-Footnote-16229466
Ref: Build<89>-Footnote-26229531
Ref: Build<89>-Footnote-36229596
Node: Windows<76>6229661
Ref: whatsnew/changelog id9796229777
Ref: 1f376229777
Ref: Windows<76>-Footnote-16230037
Ref: Windows<76>-Footnote-26230102
Node: C API<75>6230167
Ref: whatsnew/changelog id9806230265
Ref: 1f386230265
Ref: C API<75>-Footnote-16230874
Ref: C API<75>-Footnote-26230939
Node: Python 3 5 3 final6231004
Ref: whatsnew/changelog python-3-5-3-final6231150
Ref: 1f396231150
Node: Python 3 5 3 release candidate 16231297
Ref: whatsnew/changelog python-3-5-3-release-candidate-16231429
Ref: 1f3a6231429
Node: Security<59>6231818
Ref: whatsnew/changelog id9816231930
Ref: 1f3b6231930
Ref: Security<59>-Footnote-16232310
Ref: Security<59>-Footnote-26232375
Node: Core and Builtins<188>6232440
Ref: whatsnew/changelog id9826232573
Ref: 1f3c6232573
Ref: Core and Builtins<188>-Footnote-16238025
Ref: Core and Builtins<188>-Footnote-26238090
Ref: Core and Builtins<188>-Footnote-36238155
Ref: Core and Builtins<188>-Footnote-46238220
Ref: Core and Builtins<188>-Footnote-56238285
Ref: Core and Builtins<188>-Footnote-66238350
Ref: Core and Builtins<188>-Footnote-76238415
Ref: Core and Builtins<188>-Footnote-86238480
Ref: Core and Builtins<188>-Footnote-96238545
Ref: Core and Builtins<188>-Footnote-106238610
Ref: Core and Builtins<188>-Footnote-116238676
Ref: Core and Builtins<188>-Footnote-126238742
Ref: Core and Builtins<188>-Footnote-136238808
Ref: Core and Builtins<188>-Footnote-146238874
Ref: Core and Builtins<188>-Footnote-156238940
Ref: Core and Builtins<188>-Footnote-166239006
Ref: Core and Builtins<188>-Footnote-176239072
Ref: Core and Builtins<188>-Footnote-186239138
Ref: Core and Builtins<188>-Footnote-196239204
Ref: Core and Builtins<188>-Footnote-206239270
Ref: Core and Builtins<188>-Footnote-216239336
Ref: Core and Builtins<188>-Footnote-226239402
Ref: Core and Builtins<188>-Footnote-236239468
Ref: Core and Builtins<188>-Footnote-246239534
Ref: Core and Builtins<188>-Footnote-256239600
Ref: Core and Builtins<188>-Footnote-266239666
Ref: Core and Builtins<188>-Footnote-276239732
Ref: Core and Builtins<188>-Footnote-286239798
Ref: Core and Builtins<188>-Footnote-296239864
Ref: Core and Builtins<188>-Footnote-306239930
Ref: Core and Builtins<188>-Footnote-316239996
Ref: Core and Builtins<188>-Footnote-326240062
Ref: Core and Builtins<188>-Footnote-336240128
Ref: Core and Builtins<188>-Footnote-346240194
Ref: Core and Builtins<188>-Footnote-356240260
Ref: Core and Builtins<188>-Footnote-366240326
Ref: Core and Builtins<188>-Footnote-376240392
Ref: Core and Builtins<188>-Footnote-386240458
Ref: Core and Builtins<188>-Footnote-396240524
Ref: Core and Builtins<188>-Footnote-406240590
Ref: Core and Builtins<188>-Footnote-416240656
Ref: Core and Builtins<188>-Footnote-426240722
Ref: Core and Builtins<188>-Footnote-436240788
Node: Library<192>6240854
Ref: whatsnew/changelog id9836240983
Ref: 1f3d6240983
Ref: Library<192>-Footnote-16256974
Ref: Library<192>-Footnote-26257039
Ref: Library<192>-Footnote-36257104
Ref: Library<192>-Footnote-46257169
Ref: Library<192>-Footnote-56257234
Ref: Library<192>-Footnote-66257298
Ref: Library<192>-Footnote-76257363
Ref: Library<192>-Footnote-86257428
Ref: Library<192>-Footnote-96257493
Ref: Library<192>-Footnote-106257558
Ref: Library<192>-Footnote-116257624
Ref: Library<192>-Footnote-126257690
Ref: Library<192>-Footnote-136257756
Ref: Library<192>-Footnote-146257822
Ref: Library<192>-Footnote-156257888
Ref: Library<192>-Footnote-166257954
Ref: Library<192>-Footnote-176258020
Ref: Library<192>-Footnote-186258086
Ref: Library<192>-Footnote-196258152
Ref: Library<192>-Footnote-206258218
Ref: Library<192>-Footnote-216258284
Ref: Library<192>-Footnote-226258350
Ref: Library<192>-Footnote-236258416
Ref: Library<192>-Footnote-246258482
Ref: Library<192>-Footnote-256258548
Ref: Library<192>-Footnote-266258614
Ref: Library<192>-Footnote-276258680
Ref: Library<192>-Footnote-286258746
Ref: Library<192>-Footnote-296258812
Ref: Library<192>-Footnote-306258878
Ref: Library<192>-Footnote-316258944
Ref: Library<192>-Footnote-326259010
Ref: Library<192>-Footnote-336259078
Ref: Library<192>-Footnote-346259144
Ref: Library<192>-Footnote-356259210
Ref: Library<192>-Footnote-366259276
Ref: Library<192>-Footnote-376259342
Ref: Library<192>-Footnote-386259408
Ref: Library<192>-Footnote-396259474
Ref: Library<192>-Footnote-406259540
Ref: Library<192>-Footnote-416259606
Ref: Library<192>-Footnote-426259672
Ref: Library<192>-Footnote-436259738
Ref: Library<192>-Footnote-446259804
Ref: Library<192>-Footnote-456259870
Ref: Library<192>-Footnote-466259936
Ref: Library<192>-Footnote-476260002
Ref: Library<192>-Footnote-486260068
Ref: Library<192>-Footnote-496260134
Ref: Library<192>-Footnote-506260200
Ref: Library<192>-Footnote-516260266
Ref: Library<192>-Footnote-526260332
Ref: Library<192>-Footnote-536260398
Ref: Library<192>-Footnote-546260464
Ref: Library<192>-Footnote-556260530
Ref: Library<192>-Footnote-566260596
Ref: Library<192>-Footnote-576260662
Ref: Library<192>-Footnote-586260728
Ref: Library<192>-Footnote-596260794
Ref: Library<192>-Footnote-606260860
Ref: Library<192>-Footnote-616260916
Ref: Library<192>-Footnote-626260982
Ref: Library<192>-Footnote-636261048
Ref: Library<192>-Footnote-646261114
Ref: Library<192>-Footnote-656261180
Ref: Library<192>-Footnote-666261246
Ref: Library<192>-Footnote-676261312
Ref: Library<192>-Footnote-686261378
Ref: Library<192>-Footnote-696261444
Ref: Library<192>-Footnote-706261510
Ref: Library<192>-Footnote-716261576
Ref: Library<192>-Footnote-726261642
Ref: Library<192>-Footnote-736261707
Ref: Library<192>-Footnote-746261773
Ref: Library<192>-Footnote-756261839
Ref: Library<192>-Footnote-766261905
Ref: Library<192>-Footnote-776261971
Ref: Library<192>-Footnote-786262037
Ref: Library<192>-Footnote-796262103
Ref: Library<192>-Footnote-806262169
Ref: Library<192>-Footnote-816262228
Ref: Library<192>-Footnote-826262294
Ref: Library<192>-Footnote-836262360
Ref: Library<192>-Footnote-846262426
Ref: Library<192>-Footnote-856262492
Ref: Library<192>-Footnote-866262558
Ref: Library<192>-Footnote-876262624
Ref: Library<192>-Footnote-886262690
Ref: Library<192>-Footnote-896262756
Ref: Library<192>-Footnote-906262822
Ref: Library<192>-Footnote-916262888
Ref: Library<192>-Footnote-926262954
Ref: Library<192>-Footnote-936263020
Ref: Library<192>-Footnote-946263086
Ref: Library<192>-Footnote-956263152
Ref: Library<192>-Footnote-966263218
Ref: Library<192>-Footnote-976263284
Ref: Library<192>-Footnote-986263327
Ref: Library<192>-Footnote-996263393
Ref: Library<192>-Footnote-1006263459
Ref: Library<192>-Footnote-1016263526
Ref: Library<192>-Footnote-1026263593
Ref: Library<192>-Footnote-1036263660
Ref: Library<192>-Footnote-1046263727
Ref: Library<192>-Footnote-1056263794
Ref: Library<192>-Footnote-1066263861
Ref: Library<192>-Footnote-1076263928
Ref: Library<192>-Footnote-1086263995
Ref: Library<192>-Footnote-1096264062
Ref: Library<192>-Footnote-1106264129
Ref: Library<192>-Footnote-1116264196
Ref: Library<192>-Footnote-1126264263
Ref: Library<192>-Footnote-1136264330
Ref: Library<192>-Footnote-1146264397
Ref: Library<192>-Footnote-1156264464
Ref: Library<192>-Footnote-1166264531
Ref: Library<192>-Footnote-1176264598
Ref: Library<192>-Footnote-1186264665
Ref: Library<192>-Footnote-1196264732
Ref: Library<192>-Footnote-1206264799
Ref: Library<192>-Footnote-1216264866
Ref: Library<192>-Footnote-1226264933
Ref: Library<192>-Footnote-1236265000
Ref: Library<192>-Footnote-1246265067
Ref: Library<192>-Footnote-1256265134
Ref: Library<192>-Footnote-1266265201
Node: IDLE<57>6265268
Ref: whatsnew/changelog id9846265384
Ref: 1f3e6265384
Ref: IDLE<57>-Footnote-16266635
Ref: IDLE<57>-Footnote-26266700
Ref: IDLE<57>-Footnote-36266765
Ref: IDLE<57>-Footnote-46266830
Ref: IDLE<57>-Footnote-56266895
Ref: IDLE<57>-Footnote-66266960
Ref: IDLE<57>-Footnote-76267025
Ref: IDLE<57>-Footnote-86267090
Node: C API<76>6267155
Ref: whatsnew/changelog id9856267276
Ref: 1f3f6267276
Ref: C API<76>-Footnote-16267608
Ref: C API<76>-Footnote-26267673
Node: Documentation<78>6267738
Ref: whatsnew/changelog id9866267860
Ref: 1f406267860
Ref: Documentation<78>-Footnote-16268013
Node: Tests<79>6268078
Ref: whatsnew/changelog id9876268206
Ref: 1f416268206
Ref: Tests<79>-Footnote-16268897
Ref: Tests<79>-Footnote-26268962
Ref: Tests<79>-Footnote-36269027
Ref: Tests<79>-Footnote-46269092
Ref: Tests<79>-Footnote-56269157
Ref: Tests<79>-Footnote-66269222
Node: Tools/Demos<55>6269287
Ref: whatsnew/changelog id9886269409
Ref: 1f426269409
Ref: Tools/Demos<55>-Footnote-16269891
Ref: Tools/Demos<55>-Footnote-26269956
Ref: Tools/Demos<55>-Footnote-36270021
Node: Windows<77>6270086
Ref: whatsnew/changelog id9896270208
Ref: 1f436270208
Ref: Windows<77>-Footnote-16270710
Ref: Windows<77>-Footnote-26270775
Ref: Windows<77>-Footnote-36270840
Ref: Windows<77>-Footnote-46270905
Ref: Windows<77>-Footnote-56270970
Node: Build<90>6271035
Ref: whatsnew/changelog id9906271133
Ref: 1f446271133
Ref: Build<90>-Footnote-16273842
Ref: Build<90>-Footnote-26273907
Ref: Build<90>-Footnote-36273972
Ref: Build<90>-Footnote-46274037
Ref: Build<90>-Footnote-56274102
Ref: Build<90>-Footnote-66274167
Ref: Build<90>-Footnote-76274232
Ref: Build<90>-Footnote-86274297
Ref: Build<90>-Footnote-96274362
Ref: Build<90>-Footnote-106274427
Ref: Build<90>-Footnote-116274493
Ref: Build<90>-Footnote-126274559
Ref: Build<90>-Footnote-136274625
Ref: Build<90>-Footnote-146274691
Ref: Build<90>-Footnote-156274757
Ref: Build<90>-Footnote-166274823
Ref: Build<90>-Footnote-176274889
Ref: Build<90>-Footnote-186274955
Ref: Build<90>-Footnote-196275021
Ref: Build<90>-Footnote-206275087
Ref: Build<90>-Footnote-216275153
Ref: Build<90>-Footnote-226275219
Node: Python 3 5 2 final6275285
Ref: whatsnew/changelog python-3-5-2-final6275431
Ref: 1f456275431
Node: Core and Builtins<189>6275609
Ref: whatsnew/changelog id9916275704
Ref: 1f466275704
Ref: Core and Builtins<189>-Footnote-16275864
Node: Tests<80>6275929
Ref: whatsnew/changelog id9926276041
Ref: 1f476276041
Ref: Tests<80>-Footnote-16276203
Node: IDLE<58>6276268
Ref: whatsnew/changelog id9936276349
Ref: 1f486276349
Ref: IDLE<58>-Footnote-16276505
Node: Python 3 5 2 release candidate 16276570
Ref: whatsnew/changelog python-3-5-2-release-candidate-16276702
Ref: 1f496276702
Node: Security<60>6277071
Ref: whatsnew/changelog id9946277183
Ref: 1f4a6277183
Ref: Security<60>-Footnote-16278092
Ref: Security<60>-Footnote-26278157
Ref: Security<60>-Footnote-36278212
Ref: Security<60>-Footnote-46278267
Ref: Security<60>-Footnote-56278332
Ref: Security<60>-Footnote-66278397
Ref: Security<60>-Footnote-76278462
Node: Core and Builtins<190>6278527
Ref: whatsnew/changelog id9956278660
Ref: 1f4b6278660
Ref: Core and Builtins<190>-Footnote-16284511
Ref: Core and Builtins<190>-Footnote-26284576
Ref: Core and Builtins<190>-Footnote-36284641
Ref: Core and Builtins<190>-Footnote-46284706
Ref: Core and Builtins<190>-Footnote-56284771
Ref: Core and Builtins<190>-Footnote-66284836
Ref: Core and Builtins<190>-Footnote-76284901
Ref: Core and Builtins<190>-Footnote-86284966
Ref: Core and Builtins<190>-Footnote-96285031
Ref: Core and Builtins<190>-Footnote-106285096
Ref: Core and Builtins<190>-Footnote-116285162
Ref: Core and Builtins<190>-Footnote-126285228
Ref: Core and Builtins<190>-Footnote-136285294
Ref: Core and Builtins<190>-Footnote-146285360
Ref: Core and Builtins<190>-Footnote-156285426
Ref: Core and Builtins<190>-Footnote-166285492
Ref: Core and Builtins<190>-Footnote-176285558
Ref: Core and Builtins<190>-Footnote-186285623
Ref: Core and Builtins<190>-Footnote-196285689
Ref: Core and Builtins<190>-Footnote-206285755
Ref: Core and Builtins<190>-Footnote-216285821
Ref: Core and Builtins<190>-Footnote-226285887
Ref: Core and Builtins<190>-Footnote-236285953
Ref: Core and Builtins<190>-Footnote-246286019
Ref: Core and Builtins<190>-Footnote-256286085
Ref: Core and Builtins<190>-Footnote-266286151
Ref: Core and Builtins<190>-Footnote-276286217
Ref: Core and Builtins<190>-Footnote-286286283
Ref: Core and Builtins<190>-Footnote-296286349
Ref: Core and Builtins<190>-Footnote-306286415
Ref: Core and Builtins<190>-Footnote-316286481
Ref: Core and Builtins<190>-Footnote-326286524
Ref: Core and Builtins<190>-Footnote-336286590
Ref: Core and Builtins<190>-Footnote-346286656
Ref: Core and Builtins<190>-Footnote-356286722
Ref: Core and Builtins<190>-Footnote-366286788
Ref: Core and Builtins<190>-Footnote-376286854
Ref: Core and Builtins<190>-Footnote-386286920
Node: Library<193>6286986
Ref: whatsnew/changelog id9966287115
Ref: 1f4c6287115
Ref: Library<193>-Footnote-16303912
Ref: Library<193>-Footnote-26303977
Ref: Library<193>-Footnote-36304042
Ref: Library<193>-Footnote-46304084
Ref: Library<193>-Footnote-56304149
Ref: Library<193>-Footnote-66304214
Ref: Library<193>-Footnote-76304279
Ref: Library<193>-Footnote-86304344
Ref: Library<193>-Footnote-96304409
Ref: Library<193>-Footnote-106304474
Ref: Library<193>-Footnote-116304540
Ref: Library<193>-Footnote-126304606
Ref: Library<193>-Footnote-136304672
Ref: Library<193>-Footnote-146304738
Ref: Library<193>-Footnote-156304804
Ref: Library<193>-Footnote-166304870
Ref: Library<193>-Footnote-176304936
Ref: Library<193>-Footnote-186305002
Ref: Library<193>-Footnote-196305068
Ref: Library<193>-Footnote-206305134
Ref: Library<193>-Footnote-216305200
Ref: Library<193>-Footnote-226305266
Ref: Library<193>-Footnote-236305332
Ref: Library<193>-Footnote-246305398
Ref: Library<193>-Footnote-256305464
Ref: Library<193>-Footnote-266305530
Ref: Library<193>-Footnote-276305596
Ref: Library<193>-Footnote-286305662
Ref: Library<193>-Footnote-296305728
Ref: Library<193>-Footnote-306305794
Ref: Library<193>-Footnote-316305860
Ref: Library<193>-Footnote-326305926
Ref: Library<193>-Footnote-336305992
Ref: Library<193>-Footnote-346306058
Ref: Library<193>-Footnote-356306124
Ref: Library<193>-Footnote-366306190
Ref: Library<193>-Footnote-376306256
Ref: Library<193>-Footnote-386306322
Ref: Library<193>-Footnote-396306388
Ref: Library<193>-Footnote-406306454
Ref: Library<193>-Footnote-416306520
Ref: Library<193>-Footnote-426306586
Ref: Library<193>-Footnote-436306652
Ref: Library<193>-Footnote-446306718
Ref: Library<193>-Footnote-456306784
Ref: Library<193>-Footnote-466306850
Ref: Library<193>-Footnote-476306916
Ref: Library<193>-Footnote-486306982
Ref: Library<193>-Footnote-496307048
Ref: Library<193>-Footnote-506307114
Ref: Library<193>-Footnote-516307180
Ref: Library<193>-Footnote-526307246
Ref: Library<193>-Footnote-536307312
Ref: Library<193>-Footnote-546307378
Ref: Library<193>-Footnote-556307444
Ref: Library<193>-Footnote-566307510
Ref: Library<193>-Footnote-576307576
Ref: Library<193>-Footnote-586307642
Ref: Library<193>-Footnote-596307708
Ref: Library<193>-Footnote-606307774
Ref: Library<193>-Footnote-616307840
Ref: Library<193>-Footnote-626307905
Ref: Library<193>-Footnote-636307971
Ref: Library<193>-Footnote-646308037
Ref: Library<193>-Footnote-656308103
Ref: Library<193>-Footnote-666308169
Ref: Library<193>-Footnote-676308235
Ref: Library<193>-Footnote-686308301
Ref: Library<193>-Footnote-696308367
Ref: Library<193>-Footnote-706308433
Ref: Library<193>-Footnote-716308499
Ref: Library<193>-Footnote-726308565
Ref: Library<193>-Footnote-736308631
Ref: Library<193>-Footnote-746308697
Ref: Library<193>-Footnote-756308763
Ref: Library<193>-Footnote-766308829
Ref: Library<193>-Footnote-776308895
Ref: Library<193>-Footnote-786308961
Ref: Library<193>-Footnote-796309027
Ref: Library<193>-Footnote-806309093
Ref: Library<193>-Footnote-816309159
Ref: Library<193>-Footnote-826309225
Ref: Library<193>-Footnote-836309291
Ref: Library<193>-Footnote-846309357
Ref: Library<193>-Footnote-856309423
Ref: Library<193>-Footnote-866309489
Ref: Library<193>-Footnote-876309555
Ref: Library<193>-Footnote-886309621
Ref: Library<193>-Footnote-896309687
Ref: Library<193>-Footnote-906309753
Ref: Library<193>-Footnote-916309819
Ref: Library<193>-Footnote-926309885
Ref: Library<193>-Footnote-936309951
Ref: Library<193>-Footnote-946310017
Ref: Library<193>-Footnote-956310083
Ref: Library<193>-Footnote-966310149
Ref: Library<193>-Footnote-976310215
Ref: Library<193>-Footnote-986310281
Ref: Library<193>-Footnote-996310347
Ref: Library<193>-Footnote-1006310413
Ref: Library<193>-Footnote-1016310480
Ref: Library<193>-Footnote-1026310546
Ref: Library<193>-Footnote-1036310613
Ref: Library<193>-Footnote-1046310680
Ref: Library<193>-Footnote-1056310747
Ref: Library<193>-Footnote-1066310814
Ref: Library<193>-Footnote-1076310881
Ref: Library<193>-Footnote-1086310948
Ref: Library<193>-Footnote-1096311015
Ref: Library<193>-Footnote-1106311082
Ref: Library<193>-Footnote-1116311149
Ref: Library<193>-Footnote-1126311216
Ref: Library<193>-Footnote-1136311283
Ref: Library<193>-Footnote-1146311350
Ref: Library<193>-Footnote-1156311417
Ref: Library<193>-Footnote-1166311484
Ref: Library<193>-Footnote-1176311551
Ref: Library<193>-Footnote-1186311618
Ref: Library<193>-Footnote-1196311685
Ref: Library<193>-Footnote-1206311752
Node: IDLE<59>6311819
Ref: whatsnew/changelog id9976311943
Ref: 1f4d6311943
Ref: IDLE<59>-Footnote-16314306
Ref: IDLE<59>-Footnote-26314370
Ref: IDLE<59>-Footnote-36314435
Ref: IDLE<59>-Footnote-46314500
Ref: IDLE<59>-Footnote-56314565
Ref: IDLE<59>-Footnote-66314630
Ref: IDLE<59>-Footnote-76314695
Ref: IDLE<59>-Footnote-86314760
Ref: IDLE<59>-Footnote-96314825
Ref: IDLE<59>-Footnote-106314890
Ref: IDLE<59>-Footnote-116314956
Ref: IDLE<59>-Footnote-126315022
Ref: IDLE<59>-Footnote-136315088
Ref: IDLE<59>-Footnote-146315154
Ref: IDLE<59>-Footnote-156315220
Node: Documentation<79>6315286
Ref: whatsnew/changelog id9986315407
Ref: 1f4e6315407
Ref: Documentation<79>-Footnote-16316365
Ref: Documentation<79>-Footnote-26316430
Ref: Documentation<79>-Footnote-36316495
Ref: Documentation<79>-Footnote-46316537
Ref: Documentation<79>-Footnote-56316602
Ref: Documentation<79>-Footnote-66316666
Ref: Documentation<79>-Footnote-76316731
Ref: Documentation<79>-Footnote-86316796
Node: Tests<81>6316861
Ref: whatsnew/changelog id9996316983
Ref: 1f4f6316983
Ref: Tests<81>-Footnote-16317858
Ref: Tests<81>-Footnote-26317923
Ref: Tests<81>-Footnote-36317988
Ref: Tests<81>-Footnote-46318053
Ref: Tests<81>-Footnote-56318118
Ref: Tests<81>-Footnote-66318183
Ref: Tests<81>-Footnote-76318248
Node: Build<91>6318313
Ref: whatsnew/changelog id10006318429
Ref: 1f506318429
Ref: Build<91>-Footnote-16320957
Ref: Build<91>-Footnote-26321022
Ref: Build<91>-Footnote-36321087
Ref: Build<91>-Footnote-46321152
Ref: Build<91>-Footnote-56321217
Ref: Build<91>-Footnote-66321282
Ref: Build<91>-Footnote-76321347
Ref: Build<91>-Footnote-86321412
Ref: Build<91>-Footnote-96321477
Ref: Build<91>-Footnote-106321542
Ref: Build<91>-Footnote-116321608
Ref: Build<91>-Footnote-126321674
Ref: Build<91>-Footnote-136321740
Ref: Build<91>-Footnote-146321806
Ref: Build<91>-Footnote-156321872
Ref: Build<91>-Footnote-166321938
Ref: Build<91>-Footnote-176322004
Node: Windows<78>6322070
Ref: whatsnew/changelog id10016322192
Ref: 1f516322192
Ref: Windows<78>-Footnote-16322902
Ref: Windows<78>-Footnote-26322967
Ref: Windows<78>-Footnote-36323032
Ref: Windows<78>-Footnote-46323097
Ref: Windows<78>-Footnote-56323162
Ref: Windows<78>-Footnote-66323227
Node: Tools/Demos<56>6323292
Ref: whatsnew/changelog id10026323396
Ref: 1f526323396
Ref: Tools/Demos<56>-Footnote-16324020
Ref: Tools/Demos<56>-Footnote-26324085
Ref: Tools/Demos<56>-Footnote-36324150
Ref: Tools/Demos<56>-Footnote-46324215
Node: Python 3 5 1 final6324280
Ref: whatsnew/changelog python-3-5-1-final6324426
Ref: 1f536324426
Node: Core and Builtins<191>6324590
Ref: whatsnew/changelog id10036324687
Ref: 1f546324687
Ref: Core and Builtins<191>-Footnote-16324873
Node: Windows<79>6324938
Ref: whatsnew/changelog id10046325035
Ref: 1f556325035
Ref: Windows<79>-Footnote-16325227
Node: Python 3 5 1 release candidate 16325292
Ref: whatsnew/changelog python-3-5-1-release-candidate-16325424
Ref: 1f566325424
Node: Core and Builtins<192>6325767
Ref: whatsnew/changelog id10056325879
Ref: 1f576325879
Ref: Core and Builtins<192>-Footnote-16329023
Ref: Core and Builtins<192>-Footnote-26329088
Ref: Core and Builtins<192>-Footnote-36329153
Ref: Core and Builtins<192>-Footnote-46329218
Ref: Core and Builtins<192>-Footnote-56329283
Ref: Core and Builtins<192>-Footnote-66329348
Ref: Core and Builtins<192>-Footnote-76329413
Ref: Core and Builtins<192>-Footnote-86329478
Ref: Core and Builtins<192>-Footnote-96329543
Ref: Core and Builtins<192>-Footnote-106329608
Ref: Core and Builtins<192>-Footnote-116329674
Ref: Core and Builtins<192>-Footnote-126329740
Ref: Core and Builtins<192>-Footnote-136329806
Ref: Core and Builtins<192>-Footnote-146329872
Ref: Core and Builtins<192>-Footnote-156329938
Ref: Core and Builtins<192>-Footnote-166330004
Ref: Core and Builtins<192>-Footnote-176330070
Ref: Core and Builtins<192>-Footnote-186330136
Ref: Core and Builtins<192>-Footnote-196330202
Node: Library<194>6330268
Ref: whatsnew/changelog id10066330397
Ref: 1f586330397
Ref: Library<194>-Footnote-16340771
Ref: Library<194>-Footnote-26340836
Ref: Library<194>-Footnote-36340901
Ref: Library<194>-Footnote-46340966
Ref: Library<194>-Footnote-56341030
Ref: Library<194>-Footnote-66341095
Ref: Library<194>-Footnote-76341160
Ref: Library<194>-Footnote-86341225
Ref: Library<194>-Footnote-96341290
Ref: Library<194>-Footnote-106341355
Ref: Library<194>-Footnote-116341421
Ref: Library<194>-Footnote-126341487
Ref: Library<194>-Footnote-136341553
Ref: Library<194>-Footnote-146341619
Ref: Library<194>-Footnote-156341685
Ref: Library<194>-Footnote-166341751
Ref: Library<194>-Footnote-176341817
Ref: Library<194>-Footnote-186341883
Ref: Library<194>-Footnote-196341949
Ref: Library<194>-Footnote-206342015
Ref: Library<194>-Footnote-216342081
Ref: Library<194>-Footnote-226342147
Ref: Library<194>-Footnote-236342213
Ref: Library<194>-Footnote-246342279
Ref: Library<194>-Footnote-256342345
Ref: Library<194>-Footnote-266342411
Ref: Library<194>-Footnote-276342477
Ref: Library<194>-Footnote-286342543
Ref: Library<194>-Footnote-296342609
Ref: Library<194>-Footnote-306342675
Ref: Library<194>-Footnote-316342741
Ref: Library<194>-Footnote-326342807
Ref: Library<194>-Footnote-336342873
Ref: Library<194>-Footnote-346342939
Ref: Library<194>-Footnote-356343005
Ref: Library<194>-Footnote-366343071
Ref: Library<194>-Footnote-376343137
Ref: Library<194>-Footnote-386343203
Ref: Library<194>-Footnote-396343269
Ref: Library<194>-Footnote-406343335
Ref: Library<194>-Footnote-416343401
Ref: Library<194>-Footnote-426343467
Ref: Library<194>-Footnote-436343533
Ref: Library<194>-Footnote-446343599
Ref: Library<194>-Footnote-456343665
Ref: Library<194>-Footnote-466343731
Ref: Library<194>-Footnote-476343797
Ref: Library<194>-Footnote-486343863
Ref: Library<194>-Footnote-496343929
Ref: Library<194>-Footnote-506343995
Ref: Library<194>-Footnote-516344061
Ref: Library<194>-Footnote-526344127
Ref: Library<194>-Footnote-536344193
Ref: Library<194>-Footnote-546344259
Ref: Library<194>-Footnote-556344325
Ref: Library<194>-Footnote-566344391
Ref: Library<194>-Footnote-576344457
Ref: Library<194>-Footnote-586344523
Ref: Library<194>-Footnote-596344589
Ref: Library<194>-Footnote-606344655
Ref: Library<194>-Footnote-616344721
Ref: Library<194>-Footnote-626344787
Ref: Library<194>-Footnote-636344853
Ref: Library<194>-Footnote-646344919
Ref: Library<194>-Footnote-656344985
Ref: Library<194>-Footnote-666345051
Ref: Library<194>-Footnote-676345117
Ref: Library<194>-Footnote-686345183
Ref: Library<194>-Footnote-696345249
Ref: Library<194>-Footnote-706345315
Node: IDLE<60>6345381
Ref: whatsnew/changelog id10076345505
Ref: 1f596345505
Ref: IDLE<60>-Footnote-16350458
Ref: IDLE<60>-Footnote-26350523
Ref: IDLE<60>-Footnote-36350588
Ref: IDLE<60>-Footnote-46350653
Ref: IDLE<60>-Footnote-56350718
Ref: IDLE<60>-Footnote-66350783
Ref: IDLE<60>-Footnote-76350848
Ref: IDLE<60>-Footnote-86350913
Ref: IDLE<60>-Footnote-96350978
Ref: IDLE<60>-Footnote-106351043
Ref: IDLE<60>-Footnote-116351109
Ref: IDLE<60>-Footnote-126351175
Ref: IDLE<60>-Footnote-136351241
Ref: IDLE<60>-Footnote-146351307
Ref: IDLE<60>-Footnote-156351373
Ref: IDLE<60>-Footnote-166351439
Ref: IDLE<60>-Footnote-176351505
Ref: IDLE<60>-Footnote-186351571
Ref: IDLE<60>-Footnote-196351637
Ref: IDLE<60>-Footnote-206351703
Ref: IDLE<60>-Footnote-216351769
Ref: IDLE<60>-Footnote-226351835
Ref: IDLE<60>-Footnote-236351901
Ref: IDLE<60>-Footnote-246351967
Ref: IDLE<60>-Footnote-256352033
Node: Documentation<80>6352099
Ref: whatsnew/changelog id10086352220
Ref: 1f5a6352220
Ref: Documentation<80>-Footnote-16353299
Ref: Documentation<80>-Footnote-26353364
Ref: Documentation<80>-Footnote-36353429
Ref: Documentation<80>-Footnote-46353494
Ref: Documentation<80>-Footnote-56353559
Ref: Documentation<80>-Footnote-66353624
Node: Tests<82>6353689
Ref: whatsnew/changelog id10096353811
Ref: 1f5b6353811
Ref: Tests<82>-Footnote-16354320
Ref: Tests<82>-Footnote-26354385
Ref: Tests<82>-Footnote-36354450
Node: Build<92>6354515
Ref: whatsnew/changelog id10106354631
Ref: 1f5c6354631
Ref: Build<92>-Footnote-16355058
Ref: Build<92>-Footnote-26355123
Ref: Build<92>-Footnote-36355188
Node: Windows<80>6355253
Ref: whatsnew/changelog id10116355375
Ref: 1f5d6355375
Ref: Windows<80>-Footnote-16356650
Ref: Windows<80>-Footnote-26356715
Ref: Windows<80>-Footnote-36356780
Ref: Windows<80>-Footnote-46356845
Ref: Windows<80>-Footnote-56356910
Ref: Windows<80>-Footnote-66356975
Ref: Windows<80>-Footnote-76357040
Ref: Windows<80>-Footnote-86357105
Ref: Windows<80>-Footnote-96357170
Ref: Windows<80>-Footnote-106357235
Ref: Windows<80>-Footnote-116357301
Ref: Windows<80>-Footnote-126357367
Ref: Windows<80>-Footnote-136357433
Ref: Windows<80>-Footnote-146357499
Node: Tools/Demos<57>6357565
Ref: whatsnew/changelog id10126357669
Ref: 1f5e6357669
Ref: Tools/Demos<57>-Footnote-16357821
Node: Python 3 5 0 final6357886
Ref: whatsnew/changelog python-3-5-0-final6358032
Ref: 1f5f6358032
Node: Build<93>6358147
Ref: whatsnew/changelog id10136358211
Ref: 1f606358211
Ref: Build<93>-Footnote-16358389
Node: Python 3 5 0 release candidate 46358454
Ref: whatsnew/changelog python-3-5-0-release-candidate-46358600
Ref: 1f616358600
Node: Library<195>6358768
Ref: whatsnew/changelog id10146358867
Ref: 1f626358867
Ref: Library<195>-Footnote-16358998
Node: Build<94>6359063
Ref: whatsnew/changelog id10156359162
Ref: 1f636359162
Ref: Build<94>-Footnote-16359346
Node: Python 3 5 0 release candidate 36359411
Ref: whatsnew/changelog python-3-5-0-release-candidate-36359571
Ref: 1f646359571
Node: Core and Builtins<193>6359764
Ref: whatsnew/changelog id10166359876
Ref: 1f656359876
Ref: Core and Builtins<193>-Footnote-16360246
Ref: Core and Builtins<193>-Footnote-26360311
Ref: Core and Builtins<193>-Footnote-36360376
Ref: Core and Builtins<193>-Footnote-46360441
Node: Library<196>6360483
Ref: whatsnew/changelog id10176360595
Ref: 1f666360595
Ref: Library<196>-Footnote-16361371
Ref: Library<196>-Footnote-26361436
Ref: Library<196>-Footnote-36361501
Ref: Library<196>-Footnote-46361566
Ref: Library<196>-Footnote-56361631
Node: Python 3 5 0 release candidate 26361696
Ref: whatsnew/changelog python-3-5-0-release-candidate-26361856
Ref: 1f676361856
Node: Core and Builtins<194>6362049
Ref: whatsnew/changelog id10186362161
Ref: 1f686362161
Ref: Core and Builtins<194>-Footnote-16362705
Ref: Core and Builtins<194>-Footnote-26362770
Ref: Core and Builtins<194>-Footnote-36362835
Node: Library<197>6362900
Ref: whatsnew/changelog id10196363012
Ref: 1f696363012
Ref: Library<197>-Footnote-16363295
Ref: Library<197>-Footnote-26363360
Ref: Library<197>-Footnote-36363425
Node: Python 3 5 0 release candidate 16363490
Ref: whatsnew/changelog python-3-5-0-release-candidate-16363637
Ref: 1f6a6363637
Node: Core and Builtins<195>6363904
Ref: whatsnew/changelog id10206364016
Ref: 1f6b6364016
Ref: Core and Builtins<195>-Footnote-16364196
Node: Library<198>6364261
Ref: whatsnew/changelog id10216364390
Ref: 1f6c6364390
Ref: Library<198>-Footnote-16365974
Ref: Library<198>-Footnote-26366039
Ref: Library<198>-Footnote-36366104
Ref: Library<198>-Footnote-46366169
Ref: Library<198>-Footnote-56366233
Ref: Library<198>-Footnote-66366298
Ref: Library<198>-Footnote-76366363
Ref: Library<198>-Footnote-86366428
Ref: Library<198>-Footnote-96366493
Ref: Library<198>-Footnote-106366558
Ref: Library<198>-Footnote-116366624
Ref: Library<198>-Footnote-126366690
Ref: Library<198>-Footnote-136366756
Ref: Library<198>-Footnote-146366822
Ref: Library<198>-Footnote-156366888
Node: IDLE<61>6366954
Ref: whatsnew/changelog id10226367078
Ref: 1f6d6367078
Ref: IDLE<61>-Footnote-16367831
Ref: IDLE<61>-Footnote-26367896
Ref: IDLE<61>-Footnote-36367961
Ref: IDLE<61>-Footnote-46368026
Node: Documentation<81>6368091
Ref: whatsnew/changelog id10236368212
Ref: 1f6e6368212
Ref: Documentation<81>-Footnote-16368874
Ref: Documentation<81>-Footnote-26368939
Ref: Documentation<81>-Footnote-36369004
Ref: Documentation<81>-Footnote-46369069
Node: Tests<83>6369134
Ref: whatsnew/changelog id10246369238
Ref: 1f6f6369238
Ref: Tests<83>-Footnote-16369478
Node: Python 3 5 0 beta 46369543
Ref: whatsnew/changelog python-3-5-0-beta-46369677
Ref: 1f706369677
Node: Core and Builtins<196>6369864
Ref: whatsnew/changelog id10256369963
Ref: 1f716369963
Ref: Core and Builtins<196>-Footnote-16370769
Ref: Core and Builtins<196>-Footnote-26370834
Ref: Core and Builtins<196>-Footnote-36370899
Ref: Core and Builtins<196>-Footnote-46370941
Ref: Core and Builtins<196>-Footnote-56371006
Ref: Core and Builtins<196>-Footnote-66371071
Ref: Core and Builtins<196>-Footnote-76371136
Ref: Core and Builtins<196>-Footnote-86371201
Node: Library<199>6371266
Ref: whatsnew/changelog id10266371383
Ref: 1f726371383
Ref: Library<199>-Footnote-16373666
Ref: Library<199>-Footnote-26373731
Ref: Library<199>-Footnote-36373796
Ref: Library<199>-Footnote-46373861
Ref: Library<199>-Footnote-56373926
Ref: Library<199>-Footnote-66373991
Ref: Library<199>-Footnote-76374056
Ref: Library<199>-Footnote-86374121
Ref: Library<199>-Footnote-96374186
Ref: Library<199>-Footnote-106374251
Ref: Library<199>-Footnote-116374317
Ref: Library<199>-Footnote-126374383
Ref: Library<199>-Footnote-136374449
Ref: Library<199>-Footnote-146374515
Ref: Library<199>-Footnote-156374581
Ref: Library<199>-Footnote-166374647
Ref: Library<199>-Footnote-176374713
Ref: Library<199>-Footnote-186374779
Ref: Library<199>-Footnote-196374845
Node: Build<95>6374911
Ref: whatsnew/changelog id10276374997
Ref: 1f736374997
Ref: Build<95>-Footnote-16375162
Node: Python 3 5 0 beta 36375227
Ref: whatsnew/changelog python-3-5-0-beta-36375348
Ref: 1f746375348
Node: Core and Builtins<197>6375591
Ref: whatsnew/changelog id10286375690
Ref: 1f756375690
Ref: Core and Builtins<197>-Footnote-16377017
Ref: Core and Builtins<197>-Footnote-26377082
Ref: Core and Builtins<197>-Footnote-36377147
Ref: Core and Builtins<197>-Footnote-46377212
Ref: Core and Builtins<197>-Footnote-56377254
Ref: Core and Builtins<197>-Footnote-66377319
Node: Library<200>6377384
Ref: whatsnew/changelog id10296377501
Ref: 1f766377501
Ref: Library<200>-Footnote-16379459
Ref: Library<200>-Footnote-26379524
Ref: Library<200>-Footnote-36379589
Ref: Library<200>-Footnote-46379654
Ref: Library<200>-Footnote-56379719
Ref: Library<200>-Footnote-66379784
Ref: Library<200>-Footnote-76379849
Ref: Library<200>-Footnote-86379914
Ref: Library<200>-Footnote-96379979
Ref: Library<200>-Footnote-106380044
Ref: Library<200>-Footnote-116380110
Ref: Library<200>-Footnote-126380176
Ref: Library<200>-Footnote-136380242
Ref: Library<200>-Footnote-146380308
Ref: Library<200>-Footnote-156380374
Ref: Library<200>-Footnote-166380440
Ref: Library<200>-Footnote-176380506
Ref: Library<200>-Footnote-186380572
Node: Tests<84>6380638
Ref: whatsnew/changelog id10306380750
Ref: 1f776380750
Ref: Tests<84>-Footnote-16381032
Ref: Tests<84>-Footnote-26381097
Node: Documentation<82>6381162
Ref: whatsnew/changelog id10316381271
Ref: 1f786381271
Ref: Documentation<82>-Footnote-16381613
Ref: Documentation<82>-Footnote-26381678
Node: Build<96>6381743
Ref: whatsnew/changelog id10326381834
Ref: 1f796381834
Ref: Build<96>-Footnote-16381999
Node: Python 3 5 0 beta 26382064
Ref: whatsnew/changelog python-3-5-0-beta-26382185
Ref: 1f7a6382185
Node: Core and Builtins<198>6382352
Ref: whatsnew/changelog id10336382451
Ref: 1f7b6382451
Ref: Core and Builtins<198>-Footnote-16383204
Ref: Core and Builtins<198>-Footnote-26383269
Ref: Core and Builtins<198>-Footnote-36383334
Ref: Core and Builtins<198>-Footnote-46383399
Ref: Core and Builtins<198>-Footnote-56383464
Node: Library<201>6383529
Ref: whatsnew/changelog id10346383628
Ref: 1f7c6383628
Ref: Library<201>-Footnote-16384335
Ref: Library<201>-Footnote-26384400
Ref: Library<201>-Footnote-36384465
Ref: Library<201>-Footnote-46384507
Ref: Library<201>-Footnote-56384571
Ref: Library<201>-Footnote-66384636
Ref: Library<201>-Footnote-76384701
Node: Python 3 5 0 beta 16384766
Ref: whatsnew/changelog python-3-5-0-beta-16384888
Ref: 1f7d6384888
Node: Core and Builtins<199>6385161
Ref: whatsnew/changelog id10356385260
Ref: 1f7e6385260
Ref: Core and Builtins<199>-Footnote-16387133
Ref: Core and Builtins<199>-Footnote-26387198
Ref: Core and Builtins<199>-Footnote-36387263
Ref: Core and Builtins<199>-Footnote-46387328
Ref: Core and Builtins<199>-Footnote-56387393
Ref: Core and Builtins<199>-Footnote-66387458
Ref: Core and Builtins<199>-Footnote-76387523
Ref: Core and Builtins<199>-Footnote-86387588
Ref: Core and Builtins<199>-Footnote-96387653
Ref: Core and Builtins<199>-Footnote-106387718
Ref: Core and Builtins<199>-Footnote-116387783
Ref: Core and Builtins<199>-Footnote-126387849
Ref: Core and Builtins<199>-Footnote-136387915
Ref: Core and Builtins<199>-Footnote-146387981
Ref: Core and Builtins<199>-Footnote-156388047
Ref: Core and Builtins<199>-Footnote-166388113
Ref: Core and Builtins<199>-Footnote-176388179
Ref: Core and Builtins<199>-Footnote-186388244
Ref: Core and Builtins<199>-Footnote-196388310
Node: Library<202>6388376
Ref: whatsnew/changelog id10366388492
Ref: 1f7f6388492
Ref: Library<202>-Footnote-16396152
Ref: Library<202>-Footnote-26396217
Ref: Library<202>-Footnote-36396282
Ref: Library<202>-Footnote-46396347
Ref: Library<202>-Footnote-56396412
Ref: Library<202>-Footnote-66396477
Ref: Library<202>-Footnote-76396542
Ref: Library<202>-Footnote-86396607
Ref: Library<202>-Footnote-96396672
Ref: Library<202>-Footnote-106396737
Ref: Library<202>-Footnote-116396802
Ref: Library<202>-Footnote-126396868
Ref: Library<202>-Footnote-136396934
Ref: Library<202>-Footnote-146397000
Ref: Library<202>-Footnote-156397065
Ref: Library<202>-Footnote-166397131
Ref: Library<202>-Footnote-176397197
Ref: Library<202>-Footnote-186397263
Ref: Library<202>-Footnote-196397329
Ref: Library<202>-Footnote-206397395
Ref: Library<202>-Footnote-216397461
Ref: Library<202>-Footnote-226397527
Ref: Library<202>-Footnote-236397593
Ref: Library<202>-Footnote-246397659
Ref: Library<202>-Footnote-256397725
Ref: Library<202>-Footnote-266397790
Ref: Library<202>-Footnote-276397856
Ref: Library<202>-Footnote-286397922
Ref: Library<202>-Footnote-296397988
Ref: Library<202>-Footnote-306398054
Ref: Library<202>-Footnote-316398120
Ref: Library<202>-Footnote-326398186
Ref: Library<202>-Footnote-336398252
Ref: Library<202>-Footnote-346398318
Ref: Library<202>-Footnote-356398384
Ref: Library<202>-Footnote-366398450
Ref: Library<202>-Footnote-376398516
Ref: Library<202>-Footnote-386398582
Ref: Library<202>-Footnote-396398648
Ref: Library<202>-Footnote-406398714
Ref: Library<202>-Footnote-416398780
Ref: Library<202>-Footnote-426398845
Ref: Library<202>-Footnote-436398911
Ref: Library<202>-Footnote-446398977
Ref: Library<202>-Footnote-456399043
Ref: Library<202>-Footnote-466399109
Ref: Library<202>-Footnote-476399175
Ref: Library<202>-Footnote-486399241
Ref: Library<202>-Footnote-496399307
Ref: Library<202>-Footnote-506399373
Ref: Library<202>-Footnote-516399439
Ref: Library<202>-Footnote-526399505
Ref: Library<202>-Footnote-536399571
Ref: Library<202>-Footnote-546399637
Ref: Library<202>-Footnote-556399703
Ref: Library<202>-Footnote-566399769
Node: IDLE<62>6399835
Ref: whatsnew/changelog id10376399938
Ref: 1f806399938
Ref: IDLE<62>-Footnote-16400107
Node: Tests<85>6400172
Ref: whatsnew/changelog id10386400280
Ref: 1f816400280
Ref: Tests<85>-Footnote-16400578
Ref: Tests<85>-Footnote-26400643
Node: Documentation<83>6400707
Ref: whatsnew/changelog id10396400822
Ref: 1f826400822
Ref: Documentation<83>-Footnote-16401229
Ref: Documentation<83>-Footnote-26401294
Ref: Documentation<83>-Footnote-36401359
Node: Tools/Demos<58>6401424
Ref: whatsnew/changelog id10406401521
Ref: 1f836401521
Ref: Tools/Demos<58>-Footnote-16402038
Ref: Tools/Demos<58>-Footnote-26402103
Ref: Tools/Demos<58>-Footnote-36402168
Ref: Tools/Demos<58>-Footnote-46402233
Node: Python 3 5 0 alpha 46402298
Ref: whatsnew/changelog python-3-5-0-alpha-46402421
Ref: 1f846402421
Node: Core and Builtins<200>6402682
Ref: whatsnew/changelog id10416402782
Ref: 1f856402782
Ref: Core and Builtins<200>-Footnote-16404151
Ref: Core and Builtins<200>-Footnote-26404216
Ref: Core and Builtins<200>-Footnote-36404258
Ref: Core and Builtins<200>-Footnote-46404323
Ref: Core and Builtins<200>-Footnote-56404388
Ref: Core and Builtins<200>-Footnote-66404430
Ref: Core and Builtins<200>-Footnote-76404495
Ref: Core and Builtins<200>-Footnote-86404560
Ref: Core and Builtins<200>-Footnote-96404625
Ref: Core and Builtins<200>-Footnote-106404690
Ref: Core and Builtins<200>-Footnote-116404756
Node: Library<203>6404822
Ref: whatsnew/changelog id10426404940
Ref: 1f866404940
Ref: Library<203>-Footnote-16411655
Ref: Library<203>-Footnote-26411720
Ref: Library<203>-Footnote-36411785
Ref: Library<203>-Footnote-46411849
Ref: Library<203>-Footnote-56411914
Ref: Library<203>-Footnote-66411979
Ref: Library<203>-Footnote-76412043
Ref: Library<203>-Footnote-86412108
Ref: Library<203>-Footnote-96412173
Ref: Library<203>-Footnote-106412238
Ref: Library<203>-Footnote-116412304
Ref: Library<203>-Footnote-126412370
Ref: Library<203>-Footnote-136412436
Ref: Library<203>-Footnote-146412502
Ref: Library<203>-Footnote-156412568
Ref: Library<203>-Footnote-166412634
Ref: Library<203>-Footnote-176412700
Ref: Library<203>-Footnote-186412766
Ref: Library<203>-Footnote-196412832
Ref: Library<203>-Footnote-206412898
Ref: Library<203>-Footnote-216412964
Ref: Library<203>-Footnote-226413030
Ref: Library<203>-Footnote-236413096
Ref: Library<203>-Footnote-246413162
Ref: Library<203>-Footnote-256413228
Ref: Library<203>-Footnote-266413294
Ref: Library<203>-Footnote-276413360
Ref: Library<203>-Footnote-286413426
Ref: Library<203>-Footnote-296413492
Ref: Library<203>-Footnote-306413558
Ref: Library<203>-Footnote-316413623
Ref: Library<203>-Footnote-326413689
Ref: Library<203>-Footnote-336413755
Ref: Library<203>-Footnote-346413821
Ref: Library<203>-Footnote-356413887
Ref: Library<203>-Footnote-366413953
Ref: Library<203>-Footnote-376414019
Ref: Library<203>-Footnote-386414085
Ref: Library<203>-Footnote-396414151
Ref: Library<203>-Footnote-406414217
Ref: Library<203>-Footnote-416414283
Ref: Library<203>-Footnote-426414349
Ref: Library<203>-Footnote-436414392
Ref: Library<203>-Footnote-446414458
Ref: Library<203>-Footnote-456414524
Ref: Library<203>-Footnote-466414590
Ref: Library<203>-Footnote-476414656
Ref: Library<203>-Footnote-486414722
Node: Build<97>6414788
Ref: whatsnew/changelog id10436414893
Ref: 1f876414893
Ref: Build<97>-Footnote-16415174
Ref: Build<97>-Footnote-26415239
Node: Tests<86>6415304
Ref: whatsnew/changelog id10446415412
Ref: 1f886415412
Ref: Tests<86>-Footnote-16415713
Ref: Tests<86>-Footnote-26415778
Node: Tools/Demos<59>6415843
Ref: whatsnew/changelog id10456415951
Ref: 1f896415951
Ref: Tools/Demos<59>-Footnote-16416983
Ref: Tools/Demos<59>-Footnote-26417048
Ref: Tools/Demos<59>-Footnote-36417113
Ref: Tools/Demos<59>-Footnote-46417178
Ref: Tools/Demos<59>-Footnote-56417243
Ref: Tools/Demos<59>-Footnote-66417308
Node: C API<77>6417373
Ref: whatsnew/changelog id10466417463
Ref: 1f8a6417463
Ref: C API<77>-Footnote-16417618
Node: Python 3 5 0 alpha 36417683
Ref: whatsnew/changelog python-3-5-0-alpha-36417807
Ref: 1f8b6417807
Node: Core and Builtins<201>6418048
Ref: whatsnew/changelog id10476418148
Ref: 1f8c6418148
Ref: Core and Builtins<201>-Footnote-16418944
Ref: Core and Builtins<201>-Footnote-26419009
Ref: Core and Builtins<201>-Footnote-36419074
Ref: Core and Builtins<201>-Footnote-46419139
Ref: Core and Builtins<201>-Footnote-56419204
Ref: Core and Builtins<201>-Footnote-66419269
Node: Library<204>6419334
Ref: whatsnew/changelog id10486419452
Ref: 1f8d6419452
Ref: Library<204>-Footnote-16425878
Ref: Library<204>-Footnote-26425943
Ref: Library<204>-Footnote-36426008
Ref: Library<204>-Footnote-46426073
Ref: Library<204>-Footnote-56426138
Ref: Library<204>-Footnote-66426203
Ref: Library<204>-Footnote-76426268
Ref: Library<204>-Footnote-86426333
Ref: Library<204>-Footnote-96426398
Ref: Library<204>-Footnote-106426463
Ref: Library<204>-Footnote-116426529
Ref: Library<204>-Footnote-126426595
Ref: Library<204>-Footnote-136426661
Ref: Library<204>-Footnote-146426727
Ref: Library<204>-Footnote-156426792
Ref: Library<204>-Footnote-166426858
Ref: Library<204>-Footnote-176426924
Ref: Library<204>-Footnote-186426990
Ref: Library<204>-Footnote-196427056
Ref: Library<204>-Footnote-206427122
Ref: Library<204>-Footnote-216427188
Ref: Library<204>-Footnote-226427254
Ref: Library<204>-Footnote-236427320
Ref: Library<204>-Footnote-246427386
Ref: Library<204>-Footnote-256427452
Ref: Library<204>-Footnote-266427518
Ref: Library<204>-Footnote-276427584
Ref: Library<204>-Footnote-286427650
Ref: Library<204>-Footnote-296427716
Ref: Library<204>-Footnote-306427782
Ref: Library<204>-Footnote-316427847
Ref: Library<204>-Footnote-326427913
Ref: Library<204>-Footnote-336427979
Ref: Library<204>-Footnote-346428045
Ref: Library<204>-Footnote-356428110
Ref: Library<204>-Footnote-366428176
Ref: Library<204>-Footnote-376428242
Ref: Library<204>-Footnote-386428308
Ref: Library<204>-Footnote-396428374
Ref: Library<204>-Footnote-406428440
Ref: Library<204>-Footnote-416428506
Ref: Library<204>-Footnote-426428572
Node: Build<98>6428638
Ref: whatsnew/changelog id10496428743
Ref: 1f8e6428743
Ref: Build<98>-Footnote-16428888
Node: Tests<87>6428953
Ref: whatsnew/changelog id10506429061
Ref: 1f8f6429061
Ref: Tests<87>-Footnote-16429286
Ref: Tests<87>-Footnote-26429351
Node: Tools/Demos<60>6429416
Ref: whatsnew/changelog id10516429506
Ref: 1f906429506
Ref: Tools/Demos<60>-Footnote-16429775
Node: Python 3 5 0 alpha 26429840
Ref: whatsnew/changelog python-3-5-0-alpha-26429964
Ref: 1f916429964
Node: Core and Builtins<202>6430197
Ref: whatsnew/changelog id10526430297
Ref: 1f926430297
Ref: Core and Builtins<202>-Footnote-16430595
Node: Library<205>6430660
Ref: whatsnew/changelog id10536430778
Ref: 1f936430778
Ref: Library<205>-Footnote-16435093
Ref: Library<205>-Footnote-26435158
Ref: Library<205>-Footnote-36435200
Ref: Library<205>-Footnote-46435265
Ref: Library<205>-Footnote-56435330
Ref: Library<205>-Footnote-66435395
Ref: Library<205>-Footnote-76435460
Ref: Library<205>-Footnote-86435525
Ref: Library<205>-Footnote-96435590
Ref: Library<205>-Footnote-106435654
Ref: Library<205>-Footnote-116435720
Ref: Library<205>-Footnote-126435786
Ref: Library<205>-Footnote-136435852
Ref: Library<205>-Footnote-146435918
Ref: Library<205>-Footnote-156435984
Ref: Library<205>-Footnote-166436050
Ref: Library<205>-Footnote-176436115
Ref: Library<205>-Footnote-186436182
Ref: Library<205>-Footnote-196436247
Ref: Library<205>-Footnote-206436313
Ref: Library<205>-Footnote-216436378
Ref: Library<205>-Footnote-226436444
Ref: Library<205>-Footnote-236436510
Ref: Library<205>-Footnote-246436576
Ref: Library<205>-Footnote-256436642
Ref: Library<205>-Footnote-266436708
Ref: Library<205>-Footnote-276436774
Ref: Library<205>-Footnote-286436840
Ref: Library<205>-Footnote-296436906
Ref: Library<205>-Footnote-306436972
Ref: Library<205>-Footnote-316437038
Ref: Library<205>-Footnote-326437104
Ref: Library<205>-Footnote-336437170
Ref: Library<205>-Footnote-346437236
Ref: Library<205>-Footnote-356437302
Ref: Library<205>-Footnote-366437368
Ref: Library<205>-Footnote-376437434
Node: Build<99>6437500
Ref: whatsnew/changelog id10546437605
Ref: 1f946437605
Ref: Build<99>-Footnote-16437874
Ref: Build<99>-Footnote-26437939
Node: C API<78>6438004
Ref: whatsnew/changelog id10556438108
Ref: 1f956438108
Ref: C API<78>-Footnote-16438290
Node: Windows<81>6438355
Ref: whatsnew/changelog id10566438441
Ref: 1f966438441
Ref: Windows<81>-Footnote-16438738
Ref: Windows<81>-Footnote-26438803
Ref: Windows<81>-Footnote-36438845
Node: Python 3 5 0 alpha 16438910
Ref: whatsnew/changelog python-3-5-0-alpha-16439005
Ref: 1f976439005
Node: Core and Builtins<203>6439345
Ref: whatsnew/changelog id10576439445
Ref: 1f986439445
Ref: Core and Builtins<203>-Footnote-16449351
Ref: Core and Builtins<203>-Footnote-26449416
Ref: Core and Builtins<203>-Footnote-36449481
Ref: Core and Builtins<203>-Footnote-46449546
Ref: Core and Builtins<203>-Footnote-56449611
Ref: Core and Builtins<203>-Footnote-66449676
Ref: Core and Builtins<203>-Footnote-76449741
Ref: Core and Builtins<203>-Footnote-86449806
Ref: Core and Builtins<203>-Footnote-96449871
Ref: Core and Builtins<203>-Footnote-106449936
Ref: Core and Builtins<203>-Footnote-116450002
Ref: Core and Builtins<203>-Footnote-126450068
Ref: Core and Builtins<203>-Footnote-136450134
Ref: Core and Builtins<203>-Footnote-146450200
Ref: Core and Builtins<203>-Footnote-156450266
Ref: Core and Builtins<203>-Footnote-166450332
Ref: Core and Builtins<203>-Footnote-176450398
Ref: Core and Builtins<203>-Footnote-186450464
Ref: Core and Builtins<203>-Footnote-196450530
Ref: Core and Builtins<203>-Footnote-206450596
Ref: Core and Builtins<203>-Footnote-216450662
Ref: Core and Builtins<203>-Footnote-226450728
Ref: Core and Builtins<203>-Footnote-236450794
Ref: Core and Builtins<203>-Footnote-246450860
Ref: Core and Builtins<203>-Footnote-256450926
Ref: Core and Builtins<203>-Footnote-266450992
Ref: Core and Builtins<203>-Footnote-276451058
Ref: Core and Builtins<203>-Footnote-286451124
Ref: Core and Builtins<203>-Footnote-296451190
Ref: Core and Builtins<203>-Footnote-306451256
Ref: Core and Builtins<203>-Footnote-316451322
Ref: Core and Builtins<203>-Footnote-326451388
Ref: Core and Builtins<203>-Footnote-336451454
Ref: Core and Builtins<203>-Footnote-346451522
Ref: Core and Builtins<203>-Footnote-356451588
Ref: Core and Builtins<203>-Footnote-366451654
Ref: Core and Builtins<203>-Footnote-376451720
Ref: Core and Builtins<203>-Footnote-386451786
Ref: Core and Builtins<203>-Footnote-396451852
Ref: Core and Builtins<203>-Footnote-406451918
Ref: Core and Builtins<203>-Footnote-416451984
Ref: Core and Builtins<203>-Footnote-426452050
Ref: Core and Builtins<203>-Footnote-436452116
Ref: Core and Builtins<203>-Footnote-446452182
Ref: Core and Builtins<203>-Footnote-456452248
Ref: Core and Builtins<203>-Footnote-466452314
Ref: Core and Builtins<203>-Footnote-476452380
Ref: Core and Builtins<203>-Footnote-486452446
Ref: Core and Builtins<203>-Footnote-496452512
Ref: Core and Builtins<203>-Footnote-506452578
Ref: Core and Builtins<203>-Footnote-516452644
Ref: Core and Builtins<203>-Footnote-526452710
Ref: Core and Builtins<203>-Footnote-536452776
Ref: Core and Builtins<203>-Footnote-546452842
Ref: Core and Builtins<203>-Footnote-556452908
Ref: Core and Builtins<203>-Footnote-566452974
Ref: Core and Builtins<203>-Footnote-576453040
Ref: Core and Builtins<203>-Footnote-586453106
Ref: Core and Builtins<203>-Footnote-596453172
Ref: Core and Builtins<203>-Footnote-606453238
Ref: Core and Builtins<203>-Footnote-616453304
Ref: Core and Builtins<203>-Footnote-626453370
Ref: Core and Builtins<203>-Footnote-636453436
Ref: Core and Builtins<203>-Footnote-646453502
Ref: Core and Builtins<203>-Footnote-656453568
Ref: Core and Builtins<203>-Footnote-666453634
Ref: Core and Builtins<203>-Footnote-676453699
Ref: Core and Builtins<203>-Footnote-686453765
Ref: Core and Builtins<203>-Footnote-696453831
Ref: Core and Builtins<203>-Footnote-706453897
Ref: Core and Builtins<203>-Footnote-716453963
Ref: Core and Builtins<203>-Footnote-726454029
Ref: Core and Builtins<203>-Footnote-736454094
Node: Library<206>6454160
Ref: whatsnew/changelog id10586454277
Ref: 1f996454277
Ref: Library<206>-Footnote-16506762
Ref: Library<206>-Footnote-26506827
Ref: Library<206>-Footnote-36506892
Ref: Library<206>-Footnote-46506957
Ref: Library<206>-Footnote-56507022
Ref: Library<206>-Footnote-66507087
Ref: Library<206>-Footnote-76507152
Ref: Library<206>-Footnote-86507217
Ref: Library<206>-Footnote-96507282
Ref: Library<206>-Footnote-106507347
Ref: Library<206>-Footnote-116507413
Ref: Library<206>-Footnote-126507479
Ref: Library<206>-Footnote-136507545
Ref: Library<206>-Footnote-146507611
Ref: Library<206>-Footnote-156507677
Ref: Library<206>-Footnote-166507743
Ref: Library<206>-Footnote-176507809
Ref: Library<206>-Footnote-186507875
Ref: Library<206>-Footnote-196507941
Ref: Library<206>-Footnote-206508007
Ref: Library<206>-Footnote-216508073
Ref: Library<206>-Footnote-226508139
Ref: Library<206>-Footnote-236508205
Ref: Library<206>-Footnote-246508271
Ref: Library<206>-Footnote-256508337
Ref: Library<206>-Footnote-266508403
Ref: Library<206>-Footnote-276508469
Ref: Library<206>-Footnote-286508535
Ref: Library<206>-Footnote-296508601
Ref: Library<206>-Footnote-306508667
Ref: Library<206>-Footnote-316508733
Ref: Library<206>-Footnote-326508799
Ref: Library<206>-Footnote-336508865
Ref: Library<206>-Footnote-346508931
Ref: Library<206>-Footnote-356508997
Ref: Library<206>-Footnote-366509063
Ref: Library<206>-Footnote-376509129
Ref: Library<206>-Footnote-386509195
Ref: Library<206>-Footnote-396509261
Ref: Library<206>-Footnote-406509327
Ref: Library<206>-Footnote-416509393
Ref: Library<206>-Footnote-426509459
Ref: Library<206>-Footnote-436509525
Ref: Library<206>-Footnote-446509591
Ref: Library<206>-Footnote-456509657
Ref: Library<206>-Footnote-466509723
Ref: Library<206>-Footnote-476509789
Ref: Library<206>-Footnote-486509855
Ref: Library<206>-Footnote-496509921
Ref: Library<206>-Footnote-506509987
Ref: Library<206>-Footnote-516510053
Ref: Library<206>-Footnote-526510119
Ref: Library<206>-Footnote-536510185
Ref: Library<206>-Footnote-546510251
Ref: Library<206>-Footnote-556510317
Ref: Library<206>-Footnote-566510385
Ref: Library<206>-Footnote-576510451
Ref: Library<206>-Footnote-586510517
Ref: Library<206>-Footnote-596510583
Ref: Library<206>-Footnote-606510649
Ref: Library<206>-Footnote-616510715
Ref: Library<206>-Footnote-626510771
Ref: Library<206>-Footnote-636510837
Ref: Library<206>-Footnote-646510903
Ref: Library<206>-Footnote-656510969
Ref: Library<206>-Footnote-666511035
Ref: Library<206>-Footnote-676511101
Ref: Library<206>-Footnote-686511167
Ref: Library<206>-Footnote-696511233
Ref: Library<206>-Footnote-706511299
Ref: Library<206>-Footnote-716511365
Ref: Library<206>-Footnote-726511431
Ref: Library<206>-Footnote-736511497
Ref: Library<206>-Footnote-746511563
Ref: Library<206>-Footnote-756511629
Ref: Library<206>-Footnote-766511695
Ref: Library<206>-Footnote-776511761
Ref: Library<206>-Footnote-786511827
Ref: Library<206>-Footnote-796511893
Ref: Library<206>-Footnote-806511959
Ref: Library<206>-Footnote-816512025
Ref: Library<206>-Footnote-826512091
Ref: Library<206>-Footnote-836512157
Ref: Library<206>-Footnote-846512223
Ref: Library<206>-Footnote-856512289
Ref: Library<206>-Footnote-866512355
Ref: Library<206>-Footnote-876512421
Ref: Library<206>-Footnote-886512487
Ref: Library<206>-Footnote-896512553
Ref: Library<206>-Footnote-906512619
Ref: Library<206>-Footnote-916512685
Ref: Library<206>-Footnote-926512751
Ref: Library<206>-Footnote-936512817
Ref: Library<206>-Footnote-946512883
Ref: Library<206>-Footnote-956512949
Ref: Library<206>-Footnote-966513015
Ref: Library<206>-Footnote-976513080
Ref: Library<206>-Footnote-986513146
Ref: Library<206>-Footnote-996513212
Ref: Library<206>-Footnote-1006513278
Ref: Library<206>-Footnote-1016513344
Ref: Library<206>-Footnote-1026513411
Ref: Library<206>-Footnote-1036513478
Ref: Library<206>-Footnote-1046513545
Ref: Library<206>-Footnote-1056513612
Ref: Library<206>-Footnote-1066513679
Ref: Library<206>-Footnote-1076513746
Ref: Library<206>-Footnote-1086513812
Ref: Library<206>-Footnote-1096513878
Ref: Library<206>-Footnote-1106513945
Ref: Library<206>-Footnote-1116514012
Ref: Library<206>-Footnote-1126514079
Ref: Library<206>-Footnote-1136514146
Ref: Library<206>-Footnote-1146514213
Ref: Library<206>-Footnote-1156514280
Ref: Library<206>-Footnote-1166514347
Ref: Library<206>-Footnote-1176514414
Ref: Library<206>-Footnote-1186514481
Ref: Library<206>-Footnote-1196514548
Ref: Library<206>-Footnote-1206514615
Ref: Library<206>-Footnote-1216514682
Ref: Library<206>-Footnote-1226514751
Ref: Library<206>-Footnote-1236514818
Ref: Library<206>-Footnote-1246514885
Ref: Library<206>-Footnote-1256514952
Ref: Library<206>-Footnote-1266515019
Ref: Library<206>-Footnote-1276515086
Ref: Library<206>-Footnote-1286515153
Ref: Library<206>-Footnote-1296515220
Ref: Library<206>-Footnote-1306515287
Ref: Library<206>-Footnote-1316515354
Ref: Library<206>-Footnote-1326515421
Ref: Library<206>-Footnote-1336515488
Ref: Library<206>-Footnote-1346515555
Ref: Library<206>-Footnote-1356515622
Ref: Library<206>-Footnote-1366515689
Ref: Library<206>-Footnote-1376515756
Ref: Library<206>-Footnote-1386515823
Ref: Library<206>-Footnote-1396515890
Ref: Library<206>-Footnote-1406515957
Ref: Library<206>-Footnote-1416516024
Ref: Library<206>-Footnote-1426516091
Ref: Library<206>-Footnote-1436516157
Ref: Library<206>-Footnote-1446516223
Ref: Library<206>-Footnote-1456516290
Ref: Library<206>-Footnote-1466516357
Ref: Library<206>-Footnote-1476516424
Ref: Library<206>-Footnote-1486516491
Ref: Library<206>-Footnote-1496516558
Ref: Library<206>-Footnote-1506516625
Ref: Library<206>-Footnote-1516516692
Ref: Library<206>-Footnote-1526516759
Ref: Library<206>-Footnote-1536516826
Ref: Library<206>-Footnote-1546516893
Ref: Library<206>-Footnote-1556516960
Ref: Library<206>-Footnote-1566517027
Ref: Library<206>-Footnote-1576517094
Ref: Library<206>-Footnote-1586517160
Ref: Library<206>-Footnote-1596517227
Ref: Library<206>-Footnote-1606517294
Ref: Library<206>-Footnote-1616517361
Ref: Library<206>-Footnote-1626517428
Ref: Library<206>-Footnote-1636517495
Ref: Library<206>-Footnote-1646517562
Ref: Library<206>-Footnote-1656517629
Ref: Library<206>-Footnote-1666517696
Ref: Library<206>-Footnote-1676517763
Ref: Library<206>-Footnote-1686517830
Ref: Library<206>-Footnote-1696517897
Ref: Library<206>-Footnote-1706517964
Ref: Library<206>-Footnote-1716518031
Ref: Library<206>-Footnote-1726518098
Ref: Library<206>-Footnote-1736518165
Ref: Library<206>-Footnote-1746518232
Ref: Library<206>-Footnote-1756518299
Ref: Library<206>-Footnote-1766518366
Ref: Library<206>-Footnote-1776518433
Ref: Library<206>-Footnote-1786518500
Ref: Library<206>-Footnote-1796518567
Ref: Library<206>-Footnote-1806518634
Ref: Library<206>-Footnote-1816518701
Ref: Library<206>-Footnote-1826518768
Ref: Library<206>-Footnote-1836518835
Ref: Library<206>-Footnote-1846518902
Ref: Library<206>-Footnote-1856518969
Ref: Library<206>-Footnote-1866519036
Ref: Library<206>-Footnote-1876519103
Ref: Library<206>-Footnote-1886519170
Ref: Library<206>-Footnote-1896519236
Ref: Library<206>-Footnote-1906519303
Ref: Library<206>-Footnote-1916519370
Ref: Library<206>-Footnote-1926519437
Ref: Library<206>-Footnote-1936519504
Ref: Library<206>-Footnote-1946519571
Ref: Library<206>-Footnote-1956519638
Ref: Library<206>-Footnote-1966519705
Ref: Library<206>-Footnote-1976519771
Ref: Library<206>-Footnote-1986519838
Ref: Library<206>-Footnote-1996519905
Ref: Library<206>-Footnote-2006519972
Ref: Library<206>-Footnote-2016520039
Ref: Library<206>-Footnote-2026520106
Ref: Library<206>-Footnote-2036520173
Ref: Library<206>-Footnote-2046520239
Ref: Library<206>-Footnote-2056520306
Ref: Library<206>-Footnote-2066520373
Ref: Library<206>-Footnote-2076520440
Ref: Library<206>-Footnote-2086520507
Ref: Library<206>-Footnote-2096520574
Ref: Library<206>-Footnote-2106520641
Ref: Library<206>-Footnote-2116520708
Ref: Library<206>-Footnote-2126520775
Ref: Library<206>-Footnote-2136520842
Ref: Library<206>-Footnote-2146520909
Ref: Library<206>-Footnote-2156520976
Ref: Library<206>-Footnote-2166521043
Ref: Library<206>-Footnote-2176521110
Ref: Library<206>-Footnote-2186521177
Ref: Library<206>-Footnote-2196521244
Ref: Library<206>-Footnote-2206521311
Ref: Library<206>-Footnote-2216521378
Ref: Library<206>-Footnote-2226521445
Ref: Library<206>-Footnote-2236521512
Ref: Library<206>-Footnote-2246521579
Ref: Library<206>-Footnote-2256521645
Ref: Library<206>-Footnote-2266521711
Ref: Library<206>-Footnote-2276521778
Ref: Library<206>-Footnote-2286521845
Ref: Library<206>-Footnote-2296521912
Ref: Library<206>-Footnote-2306521979
Ref: Library<206>-Footnote-2316522046
Ref: Library<206>-Footnote-2326522113
Ref: Library<206>-Footnote-2336522180
Ref: Library<206>-Footnote-2346522247
Ref: Library<206>-Footnote-2356522314
Ref: Library<206>-Footnote-2366522381
Ref: Library<206>-Footnote-2376522448
Ref: Library<206>-Footnote-2386522515
Ref: Library<206>-Footnote-2396522582
Ref: Library<206>-Footnote-2406522649
Ref: Library<206>-Footnote-2416522716
Ref: Library<206>-Footnote-2426522783
Ref: Library<206>-Footnote-2436522850
Ref: Library<206>-Footnote-2446522917
Ref: Library<206>-Footnote-2456522984
Ref: Library<206>-Footnote-2466523050
Ref: Library<206>-Footnote-2476523117
Ref: Library<206>-Footnote-2486523184
Ref: Library<206>-Footnote-2496523251
Ref: Library<206>-Footnote-2506523318
Ref: Library<206>-Footnote-2516523385
Ref: Library<206>-Footnote-2526523452
Ref: Library<206>-Footnote-2536523519
Ref: Library<206>-Footnote-2546523586
Ref: Library<206>-Footnote-2556523653
Ref: Library<206>-Footnote-2566523720
Ref: Library<206>-Footnote-2576523787
Ref: Library<206>-Footnote-2586523854
Ref: Library<206>-Footnote-2596523921
Ref: Library<206>-Footnote-2606523988
Ref: Library<206>-Footnote-2616524055
Ref: Library<206>-Footnote-2626524122
Ref: Library<206>-Footnote-2636524189
Ref: Library<206>-Footnote-2646524256
Ref: Library<206>-Footnote-2656524323
Ref: Library<206>-Footnote-2666524390
Ref: Library<206>-Footnote-2676524457
Ref: Library<206>-Footnote-2686524524
Ref: Library<206>-Footnote-2696524591
Ref: Library<206>-Footnote-2706524658
Ref: Library<206>-Footnote-2716524725
Ref: Library<206>-Footnote-2726524792
Ref: Library<206>-Footnote-2736524859
Ref: Library<206>-Footnote-2746524926
Ref: Library<206>-Footnote-2756524993
Ref: Library<206>-Footnote-2766525060
Ref: Library<206>-Footnote-2776525127
Ref: Library<206>-Footnote-2786525193
Ref: Library<206>-Footnote-2796525260
Ref: Library<206>-Footnote-2806525327
Ref: Library<206>-Footnote-2816525394
Ref: Library<206>-Footnote-2826525461
Ref: Library<206>-Footnote-2836525528
Ref: Library<206>-Footnote-2846525595
Ref: Library<206>-Footnote-2856525662
Ref: Library<206>-Footnote-2866525729
Ref: Library<206>-Footnote-2876525796
Ref: Library<206>-Footnote-2886525863
Ref: Library<206>-Footnote-2896525930
Ref: Library<206>-Footnote-2906525974
Ref: Library<206>-Footnote-2916526041
Ref: Library<206>-Footnote-2926526108
Ref: Library<206>-Footnote-2936526175
Ref: Library<206>-Footnote-2946526242
Ref: Library<206>-Footnote-2956526309
Ref: Library<206>-Footnote-2966526376
Ref: Library<206>-Footnote-2976526443
Ref: Library<206>-Footnote-2986526510
Ref: Library<206>-Footnote-2996526577
Ref: Library<206>-Footnote-3006526644
Ref: Library<206>-Footnote-3016526711
Ref: Library<206>-Footnote-3026526778
Ref: Library<206>-Footnote-3036526845
Ref: Library<206>-Footnote-3046526912
Ref: Library<206>-Footnote-3056526979
Ref: Library<206>-Footnote-3066527046
Ref: Library<206>-Footnote-3076527113
Ref: Library<206>-Footnote-3086527180
Ref: Library<206>-Footnote-3096527247
Ref: Library<206>-Footnote-3106527314
Ref: Library<206>-Footnote-3116527381
Ref: Library<206>-Footnote-3126527448
Ref: Library<206>-Footnote-3136527515
Ref: Library<206>-Footnote-3146527582
Ref: Library<206>-Footnote-3156527649
Ref: Library<206>-Footnote-3166527715
Ref: Library<206>-Footnote-3176527782
Ref: Library<206>-Footnote-3186527849
Ref: Library<206>-Footnote-3196527916
Ref: Library<206>-Footnote-3206527983
Ref: Library<206>-Footnote-3216528050
Ref: Library<206>-Footnote-3226528117
Ref: Library<206>-Footnote-3236528184
Ref: Library<206>-Footnote-3246528251
Ref: Library<206>-Footnote-3256528318
Ref: Library<206>-Footnote-3266528385
Ref: Library<206>-Footnote-3276528452
Ref: Library<206>-Footnote-3286528519
Ref: Library<206>-Footnote-3296528586
Ref: Library<206>-Footnote-3306528653
Ref: Library<206>-Footnote-3316528720
Ref: Library<206>-Footnote-3326528787
Ref: Library<206>-Footnote-3336528854
Ref: Library<206>-Footnote-3346528921
Ref: Library<206>-Footnote-3356528988
Ref: Library<206>-Footnote-3366529054
Ref: Library<206>-Footnote-3376529121
Ref: Library<206>-Footnote-3386529188
Ref: Library<206>-Footnote-3396529245
Ref: Library<206>-Footnote-3406529312
Ref: Library<206>-Footnote-3416529379
Ref: Library<206>-Footnote-3426529446
Ref: Library<206>-Footnote-3436529513
Ref: Library<206>-Footnote-3446529580
Ref: Library<206>-Footnote-3456529647
Ref: Library<206>-Footnote-3466529714
Ref: Library<206>-Footnote-3476529781
Ref: Library<206>-Footnote-3486529848
Ref: Library<206>-Footnote-3496529915
Ref: Library<206>-Footnote-3506529982
Ref: Library<206>-Footnote-3516530049
Ref: Library<206>-Footnote-3526530116
Ref: Library<206>-Footnote-3536530183
Ref: Library<206>-Footnote-3546530250
Ref: Library<206>-Footnote-3556530317
Ref: Library<206>-Footnote-3566530384
Ref: Library<206>-Footnote-3576530451
Ref: Library<206>-Footnote-3586530518
Ref: Library<206>-Footnote-3596530585
Ref: Library<206>-Footnote-3606530652
Ref: Library<206>-Footnote-3616530719
Ref: Library<206>-Footnote-3626530786
Ref: Library<206>-Footnote-3636530853
Ref: Library<206>-Footnote-3646530920
Ref: Library<206>-Footnote-3656530987
Ref: Library<206>-Footnote-3666531054
Ref: Library<206>-Footnote-3676531121
Ref: Library<206>-Footnote-3686531188
Ref: Library<206>-Footnote-3696531255
Ref: Library<206>-Footnote-3706531322
Ref: Library<206>-Footnote-3716531389
Ref: Library<206>-Footnote-3726531456
Ref: Library<206>-Footnote-3736531522
Ref: Library<206>-Footnote-3746531589
Ref: Library<206>-Footnote-3756531656
Ref: Library<206>-Footnote-3766531723
Ref: Library<206>-Footnote-3776531790
Ref: Library<206>-Footnote-3786531857
Ref: Library<206>-Footnote-3796531924
Ref: Library<206>-Footnote-3806531991
Ref: Library<206>-Footnote-3816532058
Ref: Library<206>-Footnote-3826532125
Ref: Library<206>-Footnote-3836532192
Ref: Library<206>-Footnote-3846532259
Ref: Library<206>-Footnote-3856532326
Ref: Library<206>-Footnote-3866532392
Ref: Library<206>-Footnote-3876532459
Ref: Library<206>-Footnote-3886532526
Ref: Library<206>-Footnote-3896532593
Ref: Library<206>-Footnote-3906532660
Ref: Library<206>-Footnote-3916532725
Ref: Library<206>-Footnote-3926532792
Ref: Library<206>-Footnote-3936532859
Ref: Library<206>-Footnote-3946532926
Ref: Library<206>-Footnote-3956532993
Ref: Library<206>-Footnote-3966533060
Ref: Library<206>-Footnote-3976533127
Ref: Library<206>-Footnote-3986533194
Node: IDLE<63>6533261
Ref: whatsnew/changelog id10596533366
Ref: 1f9a6533366
Ref: IDLE<63>-Footnote-16536860
Ref: IDLE<63>-Footnote-26536925
Ref: IDLE<63>-Footnote-36536990
Ref: IDLE<63>-Footnote-46537054
Ref: IDLE<63>-Footnote-56537119
Ref: IDLE<63>-Footnote-66537183
Ref: IDLE<63>-Footnote-76537248
Ref: IDLE<63>-Footnote-86537313
Ref: IDLE<63>-Footnote-96537378
Ref: IDLE<63>-Footnote-106537443
Ref: IDLE<63>-Footnote-116537509
Ref: IDLE<63>-Footnote-126537575
Ref: IDLE<63>-Footnote-136537641
Ref: IDLE<63>-Footnote-146537707
Ref: IDLE<63>-Footnote-156537773
Ref: IDLE<63>-Footnote-166537839
Ref: IDLE<63>-Footnote-176537905
Ref: IDLE<63>-Footnote-186537971
Ref: IDLE<63>-Footnote-196538037
Ref: IDLE<63>-Footnote-206538103
Ref: IDLE<63>-Footnote-216538169
Ref: IDLE<63>-Footnote-226538235
Ref: IDLE<63>-Footnote-236538301
Ref: IDLE<63>-Footnote-246538344
Ref: IDLE<63>-Footnote-256538410
Ref: IDLE<63>-Footnote-266538476
Node: Build<100>6538542
Ref: whatsnew/changelog id10606538644
Ref: 1f9b6538644
Ref: Build<100>-Footnote-16542068
Ref: Build<100>-Footnote-26542133
Ref: Build<100>-Footnote-36542198
Ref: Build<100>-Footnote-46542263
Ref: Build<100>-Footnote-56542328
Ref: Build<100>-Footnote-66542393
Ref: Build<100>-Footnote-76542458
Ref: Build<100>-Footnote-86542523
Ref: Build<100>-Footnote-96542588
Ref: Build<100>-Footnote-106542653
Ref: Build<100>-Footnote-116542719
Ref: Build<100>-Footnote-126542785
Ref: Build<100>-Footnote-136542851
Ref: Build<100>-Footnote-146542917
Ref: Build<100>-Footnote-156542983
Ref: Build<100>-Footnote-166543049
Ref: Build<100>-Footnote-176543115
Ref: Build<100>-Footnote-186543181
Ref: Build<100>-Footnote-196543247
Ref: Build<100>-Footnote-206543313
Ref: Build<100>-Footnote-216543379
Ref: Build<100>-Footnote-226543445
Ref: Build<100>-Footnote-236543511
Ref: Build<100>-Footnote-246543577
Ref: Build<100>-Footnote-256543643
Ref: Build<100>-Footnote-266543709
Node: C API<79>6543775
Ref: whatsnew/changelog id10616543886
Ref: 1f9c6543886
Ref: C API<79>-Footnote-16545253
Ref: C API<79>-Footnote-26545318
Ref: C API<79>-Footnote-36545383
Ref: C API<79>-Footnote-46545448
Ref: C API<79>-Footnote-56545513
Ref: C API<79>-Footnote-66545578
Ref: C API<79>-Footnote-76545643
Node: Documentation<84>6545708
Ref: whatsnew/changelog id10626545818
Ref: 1f9d6545818
Ref: Documentation<84>-Footnote-16547627
Ref: Documentation<84>-Footnote-26547692
Ref: Documentation<84>-Footnote-36547757
Ref: Documentation<84>-Footnote-46547822
Ref: Documentation<84>-Footnote-56547887
Ref: Documentation<84>-Footnote-66547951
Ref: Documentation<84>-Footnote-76548016
Ref: Documentation<84>-Footnote-86548081
Ref: Documentation<84>-Footnote-96548146
Ref: Documentation<84>-Footnote-106548211
Ref: Documentation<84>-Footnote-116548277
Node: Tests<88>6548343
Ref: whatsnew/changelog id10636548459
Ref: 1f9e6548459
Ref: Tests<88>-Footnote-16552652
Ref: Tests<88>-Footnote-26552717
Ref: Tests<88>-Footnote-36552782
Ref: Tests<88>-Footnote-46552847
Ref: Tests<88>-Footnote-56552912
Ref: Tests<88>-Footnote-66552977
Ref: Tests<88>-Footnote-76553042
Ref: Tests<88>-Footnote-86553107
Ref: Tests<88>-Footnote-96553172
Ref: Tests<88>-Footnote-106553237
Ref: Tests<88>-Footnote-116553303
Ref: Tests<88>-Footnote-126553369
Ref: Tests<88>-Footnote-136553435
Ref: Tests<88>-Footnote-146553501
Ref: Tests<88>-Footnote-156553566
Ref: Tests<88>-Footnote-166553632
Ref: Tests<88>-Footnote-176553698
Ref: Tests<88>-Footnote-186553764
Ref: Tests<88>-Footnote-196553830
Ref: Tests<88>-Footnote-206553896
Ref: Tests<88>-Footnote-216553962
Ref: Tests<88>-Footnote-226554028
Ref: Tests<88>-Footnote-236554094
Ref: Tests<88>-Footnote-246554160
Ref: Tests<88>-Footnote-256554226
Ref: Tests<88>-Footnote-266554292
Ref: Tests<88>-Footnote-276554358
Ref: Tests<88>-Footnote-286554424
Ref: Tests<88>-Footnote-296554490
Ref: Tests<88>-Footnote-306554556
Ref: Tests<88>-Footnote-316554622
Ref: Tests<88>-Footnote-326554688
Ref: Tests<88>-Footnote-336554754
Ref: Tests<88>-Footnote-346554820
Ref: Tests<88>-Footnote-356554886
Ref: Tests<88>-Footnote-366554952
Ref: Tests<88>-Footnote-376555018
Node: Tools/Demos<61>6555084
Ref: whatsnew/changelog id10646555194
Ref: 1f9f6555194
Ref: Tools/Demos<61>-Footnote-16556864
Ref: Tools/Demos<61>-Footnote-26556929
Ref: Tools/Demos<61>-Footnote-36556994
Ref: Tools/Demos<61>-Footnote-46557059
Ref: Tools/Demos<61>-Footnote-56557124
Ref: Tools/Demos<61>-Footnote-66557189
Ref: Tools/Demos<61>-Footnote-76557254
Ref: Tools/Demos<61>-Footnote-86557319
Ref: Tools/Demos<61>-Footnote-96557384
Ref: Tools/Demos<61>-Footnote-106557449
Ref: Tools/Demos<61>-Footnote-116557492
Ref: Tools/Demos<61>-Footnote-126557558
Ref: Tools/Demos<61>-Footnote-136557624
Node: Windows<82>6557690
Ref: whatsnew/changelog id10656557782
Ref: 1fa06557782
Ref: Windows<82>-Footnote-16558993
Ref: Windows<82>-Footnote-26559058
Ref: Windows<82>-Footnote-36559123
Ref: Windows<82>-Footnote-46559188
Ref: Windows<82>-Footnote-56559253
Ref: Windows<82>-Footnote-66559318
Ref: Windows<82>-Footnote-76559383
Node: Tutorial su Python6559448
Ref: tutorial/index doc6559563
Ref: 1fa16559563
Ref: tutorial/index the-python-tutorial6559563
Ref: 1fa26559563
Ref: tutorial/index translation-repo6559563
Ref: 1fa36559563
Ref: tutorial/index tutorial-index6559563
Ref: 1fa46559563
Node: Stuzzichiamo il tuo appetito6562716
Ref: tutorial/appetite doc6562839
Ref: 1fa86562839
Ref: tutorial/appetite tut-intro6562839
Ref: 1fa96562839
Ref: tutorial/appetite whetting-your-appetite6562839
Ref: 1faa6562839
Node: Uso dell’interprete di Python6568024
Ref: tutorial/interpreter doc6568192
Ref: 1fab6568192
Ref: tutorial/interpreter translation-repo6568192
Ref: 1fac6568192
Ref: tutorial/interpreter tut-using6568192
Ref: 1fad6568192
Ref: tutorial/interpreter using-the-python-interpreter6568192
Ref: 1fae6568192
Node: Invocazione dell’interprete6568344
Ref: tutorial/interpreter invoking-the-interpreter6568482
Ref: 1faf6568482
Ref: tutorial/interpreter tut-invoking6568482
Ref: 1fb06568482
Ref: Invocazione dell’interprete-Footnote-16571673
Node: Passare Argomenti6571880
Ref: tutorial/interpreter argument-passing6571993
Ref: 1fb46571993
Ref: tutorial/interpreter tut-argpassing6571993
Ref: 1fb56571993
Node: Modalità Interattiva6573052
Ref: tutorial/interpreter interactive-mode6573165
Ref: 1fb66573165
Ref: tutorial/interpreter tut-interactive6573165
Ref: 4436573165
Node: L’interprete e il suo ambiente6574318
Ref: tutorial/interpreter the-interpreter-and-its-environment6574456
Ref: 1fb76574456
Ref: tutorial/interpreter tut-interp6574456
Ref: 1fb86574456
Node: Codifica del codice sorgente6574576
Ref: tutorial/interpreter source-code-encoding6574673
Ref: 1fb96574673
Ref: tutorial/interpreter tut-source-encoding6574673
Ref: 1fba6574673
Node: Un’introduzione informale a Python6576062
Ref: tutorial/introduction doc6576241
Ref: 1fbc6576241
Ref: tutorial/introduction an-informal-introduction-to-python6576241
Ref: 1fbd6576241
Ref: tutorial/introduction translation-repo6576241
Ref: 1fbe6576241
Ref: tutorial/introduction tut-informal6576241
Ref: 1fbf6576241
Node: Usare Python come calcolatrice6577640
Ref: tutorial/introduction tut-calculator6577781
Ref: 1fc06577781
Ref: tutorial/introduction using-python-as-a-calculator6577781
Ref: 1fc16577781
Node: Numeri6578044
Ref: tutorial/introduction numbers6578131
Ref: 1fc26578131
Ref: tutorial/introduction tut-numbers6578131
Ref: 1fc36578131
Ref: Numeri-Footnote-16581274
Node: Testo6581500
Ref: tutorial/introduction text6581601
Ref: 1fc56581601
Ref: tutorial/introduction tut-strings6581601
Ref: 1fc66581601
Ref: Testo-Footnote-16590304
Node: Liste6590695
Ref: tutorial/introduction lists6590781
Ref: 1fcb6590781
Ref: tutorial/introduction tut-lists6590781
Ref: 1fcc6590781
Node: Primi passi di programmazione6594191
Ref: tutorial/introduction first-steps-towards-programming6594332
Ref: 1fcf6594332
Ref: tutorial/introduction tut-firststeps6594332
Ref: 1fd06594332
Ref: Primi passi di programmazione-Footnote-16597624
Node: Altri Strumenti di Controllo del Flusso6597687
Ref: tutorial/controlflow doc6597849
Ref: 1fd16597849
Ref: tutorial/controlflow more-control-flow-tools6597849
Ref: 1fd26597849
Ref: tutorial/controlflow translation-repo6597849
Ref: 1fd36597849
Ref: tutorial/controlflow tut-morecontrol6597849
Ref: 1fd46597849
Node: Istruzioni if6598400
Ref: tutorial/controlflow if-statements6598512
Ref: 1fd56598512
Ref: tutorial/controlflow tut-if6598512
Ref: 1fd66598512
Node: Istruzioni for6599569
Ref: tutorial/controlflow for-statements6599707
Ref: 1fd86599707
Ref: tutorial/controlflow tut-for6599707
Ref: 1fd96599707
Node: La Funzione range6601121
Ref: tutorial/controlflow the-range-function6601275
Ref: 1fda6601275
Ref: tutorial/controlflow tut-range6601275
Ref: 1fdb6601275
Node: break and continue Statements6603536
Ref: tutorial/controlflow break-and-continue-statements6603697
Ref: 1fde6603697
Ref: tutorial/controlflow tut-break6603697
Ref: 1fdf6603697
Ref: tutorial/controlflow tut-for-else6604677
Ref: 1fe06604677
Node: else Clauses on Loops6604678
Ref: tutorial/controlflow break-and-continue-statements-and-else-clauses-on-loops6604837
Ref: 1fe16604837
Ref: tutorial/controlflow else-clauses-on-loops6604837
Ref: 1fe26604837
Node: Istruzioni pass6607087
Ref: tutorial/controlflow pass-statements6607233
Ref: 1fe46607233
Ref: tutorial/controlflow tut-pass6607233
Ref: 1fe56607233
Node: Istruzioni match6608379
Ref: tutorial/controlflow match-statements6608527
Ref: 1fe76608527
Ref: tutorial/controlflow tut-match6608527
Ref: 1fd76608527
Ref: Istruzioni match-Footnote-16615665
Node: Definizione di Funzioni6615707
Ref: tutorial/controlflow defining-functions6615892
Ref: 1fe86615892
Ref: tutorial/controlflow tut-functions6615892
Ref: 1fe96615892
Ref: Definizione di Funzioni-Footnote-16621437
Node: Ulteriori informazioni sulla Definizione di Funzioni6621678
Ref: tutorial/controlflow more-on-defining-functions6621875
Ref: 1fec6621875
Ref: tutorial/controlflow tut-defining6621875
Ref: 1fed6621875
Node: Valori predefiniti degli argomenti6622385
Ref: tutorial/controlflow default-argument-values6622540
Ref: 1fee6622540
Ref: tutorial/controlflow tut-defaultargs6622540
Ref: 1fef6622540
Node: Argomenti chiave-valore6624695
Ref: tutorial/controlflow keyword-arguments6624877
Ref: 1ff06624877
Ref: tutorial/controlflow tut-keywordargs6624877
Ref: 1ff16624877
Node: Parametri speciali6628808
Ref: tutorial/controlflow special-parameters6628985
Ref: 1ff36628985
Node: Argomenti Posizionali o per Chiave6630270
Ref: tutorial/controlflow positional-or-keyword-arguments6630396
Ref: 1ff46630396
Node: Parametri Solo per Posizione6630637
Ref: tutorial/controlflow positional-only-parameters6630797
Ref: 1ff56630797
Node: Argomenti Solo per Chiave6631473
Ref: tutorial/controlflow keyword-only-arguments6631617
Ref: 1ff66631617
Node: Esempi di Funzioni6631915
Ref: tutorial/controlflow function-examples6632040
Ref: 1ff76632040
Node: Riepilogo6635216
Ref: tutorial/controlflow recap6635307
Ref: 1ff86635307
Node: Liste di Argomenti Arbitrarie6636260
Ref: tutorial/controlflow arbitrary-argument-lists6636454
Ref: 1ff96636454
Ref: tutorial/controlflow tut-arbitraryargs6636454
Ref: 1ffa6636454
Node: Spacchettamento delle Liste di Argomenti6637576
Ref: tutorial/controlflow tut-unpacking-arguments6637770
Ref: 1ffb6637770
Ref: tutorial/controlflow unpacking-argument-lists6637770
Ref: 1ffc6637770
Node: Espressioni Lambda6639079
Ref: tutorial/controlflow lambda-expressions6639270
Ref: 1ffd6639270
Ref: tutorial/controlflow tut-lambda6639270
Ref: 1ffe6639270
Node: Stringhe di Documentazione6640434
Ref: tutorial/controlflow documentation-strings6640611
Ref: 1fff6640611
Ref: tutorial/controlflow tut-docstrings6640611
Ref: 1fea6640611
Node: Annotationi delle Funzioni6642074
Ref: tutorial/controlflow function-annotations6642224
Ref: 20006642224
Ref: tutorial/controlflow tut-annotations6642224
Ref: 20016642224
Ref: Annotationi delle Funzioni-Footnote-16643492
Ref: Annotationi delle Funzioni-Footnote-26643534
Node: Intermezzo Stile di Codifica6643576
Ref: tutorial/controlflow intermezzo-coding-style6643741
Ref: 20046643741
Ref: tutorial/controlflow tut-codingstyle6643741
Ref: 20056643741
Ref: Intermezzo Stile di Codifica-Footnote-16646240
Node: Strutture Dati6646282
Ref: tutorial/datastructures doc6646414
Ref: 20076646414
Ref: tutorial/datastructures data-structures6646414
Ref: 20086646414
Ref: tutorial/datastructures translation-repo6646414
Ref: 20096646414
Ref: tutorial/datastructures tut-structures6646414
Ref: 1fdd6646414
Node: Più sulle Liste6646780
Ref: tutorial/datastructures more-on-lists6646874
Ref: 200a6646874
Ref: tutorial/datastructures tut-morelists6646874
Ref: 200b6646874
Ref: Più sulle Liste-Footnote-16650803
Node: Usare le Liste come Pile6650956
Ref: tutorial/datastructures tut-lists-as-stacks6651066
Ref: 200d6651066
Ref: tutorial/datastructures using-lists-as-stacks6651066
Ref: 200e6651066
Node: Usare le Liste come Code6651747
Ref: tutorial/datastructures tut-lists-as-queues6651887
Ref: 20106651887
Ref: tutorial/datastructures using-lists-as-queues6651887
Ref: 20116651887
Node: Comprensioni di Lista6652992
Ref: tutorial/datastructures list-comprehensions6653140
Ref: 20126653140
Ref: tutorial/datastructures tut-listcomps6653140
Ref: 20136653140
Node: Comprensioni di Lista Nidificate6656488
Ref: tutorial/datastructures nested-list-comprehensions6656603
Ref: 20146656603
Node: L’istruzione del6658357
Ref: tutorial/datastructures the-del-statement6658476
Ref: 20156658476
Ref: tutorial/datastructures tut-del6658476
Ref: 20166658476
Node: Tuple e Sequenze6659411
Ref: tutorial/datastructures tuples-and-sequences6659521
Ref: 20176659521
Ref: tutorial/datastructures tut-tuples6659521
Ref: 1ff26659521
Node: Insiemi6662677
Ref: tutorial/datastructures sets6662778
Ref: 20196662778
Ref: tutorial/datastructures tut-sets6662778
Ref: 201a6662778
Node: Dizionari6664581
Ref: tutorial/datastructures dictionaries6664685
Ref: 201c6664685
Ref: tutorial/datastructures tut-dictionaries6664685
Ref: 201d6664685
Node: Tecniche di Looping6668175
Ref: tutorial/datastructures looping-techniques6668310
Ref: 201f6668310
Ref: tutorial/datastructures tut-loopidioms6668310
Ref: 1fdc6668310
Node: Maggiori informazioni sulle Condizioni6670992
Ref: tutorial/datastructures more-on-conditions6671153
Ref: 20206671153
Ref: tutorial/datastructures tut-conditions6671153
Ref: 20216671153
Node: Confronto tra Sequenze e Altri Tipi6673483
Ref: tutorial/datastructures comparing-sequences-and-other-types6673616
Ref: 20236673616
Ref: tutorial/datastructures tut-comparing6673616
Ref: 20246673616
Node: Moduli6675312
Ref: tutorial/modules doc6675419
Ref: 20256675419
Ref: tutorial/modules modules6675419
Ref: 20266675419
Ref: tutorial/modules translation-repo6675419
Ref: 20276675419
Ref: tutorial/modules tut-modules6675419
Ref: 20286675419
Node: Più sui Moduli6678149
Ref: tutorial/modules more-on-modules6678231
Ref: 202b6678231
Ref: tutorial/modules tut-moremodules6678231
Ref: 202c6678231
Ref: Più sui Moduli-Footnote-16681615
Node: Esecuzione di moduli come script6681856
Ref: tutorial/modules executing-modules-as-scripts6681982
Ref: 202d6681982
Ref: tutorial/modules tut-modulesasscripts6681982
Ref: 202e6681982
Node: Il percorso di ricerca del modulo6682928
Ref: tutorial/modules the-module-search-path6683088
Ref: 202f6683088
Ref: tutorial/modules tut-searchpath6683088
Ref: 20306683088
Node: File Python «compilati»6684913
Ref: tutorial/modules compiled-python-files6685032
Ref: 20336685032
Ref: tutorial/modules tut-pycache6685032
Ref: 8ec6685032
Ref: File Python «compilati»-Footnote-16687525
Node: Moduli Standard6687567
Ref: tutorial/modules standard-modules6687673
Ref: 20346687673
Ref: tutorial/modules tut-standardmodules6687673
Ref: 20326687673
Node: La funzione dir6689218
Ref: tutorial/modules the-dir-function6689318
Ref: 20356689318
Ref: tutorial/modules tut-dir6689318
Ref: 20366689318
Node: Pacchetti6693831
Ref: tutorial/modules packages6693907
Ref: 20376693907
Ref: tutorial/modules tut-packages6693907
Ref: 20386693907
Node: Importare * Da un Pacchetto6698599
Ref: tutorial/modules importing-from-a-package6698708
Ref: 20396698708
Ref: tutorial/modules tut-pkg-import-star6698708
Ref: 203a6698708
Node: Riferimenti Intra-pacchetto6702390
Ref: tutorial/modules id26702539
Ref: 203b6702539
Ref: tutorial/modules intra-package-references6702539
Ref: 203c6702539
Node: Pacchetti in Directory Multiple6703609
Ref: tutorial/modules packages-in-multiple-directories6703722
Ref: 203d6703722
Node: Input e Output6704314
Ref: tutorial/inputoutput doc6704426
Ref: 203f6704426
Ref: tutorial/inputoutput input-and-output6704426
Ref: 20406704426
Ref: tutorial/inputoutput translation-repo6704426
Ref: 20416704426
Ref: tutorial/inputoutput tut-io6704426
Ref: 20426704426
Node: Formattazione Avanzata dell’Output6704774
Ref: tutorial/inputoutput fancier-output-formatting6704897
Ref: 20436704897
Ref: tutorial/inputoutput tut-formatting6704897
Ref: 20446704897
Node: Stringhe Formattate Letterali6709350
Ref: tutorial/inputoutput formatted-string-literals6709484
Ref: 20476709484
Ref: tutorial/inputoutput tut-f-strings6709484
Ref: 20466709484
Node: Il Metodo String format6711605
Ref: tutorial/inputoutput the-string-format-method6711784
Ref: 20486711784
Ref: tutorial/inputoutput tut-string-format6711784
Ref: 20496711784
Node: Formattazione Manuale delle Stringhe6714804
Ref: tutorial/inputoutput manual-string-formatting6714990
Ref: 204a6714990
Node: Vecchia formattazione delle stringhe6716590
Ref: tutorial/inputoutput old-string-formatting6716744
Ref: 204e6716744
Node: Lettura e Scrittura di File6717382
Ref: tutorial/inputoutput reading-and-writing-files6717505
Ref: 204f6717505
Ref: tutorial/inputoutput tut-files6717505
Ref: 20506717505
Node: Metodi degli Oggetti File6721045
Ref: tutorial/inputoutput methods-of-file-objects6721176
Ref: 20516721176
Ref: tutorial/inputoutput tut-filemethods6721176
Ref: 20526721176
Node: Salvare dati strutturati con json6725071
Ref: tutorial/inputoutput saving-structured-data-with-json6725202
Ref: 20546725202
Ref: tutorial/inputoutput tut-json6725202
Ref: 20556725202
Ref: Salvare dati strutturati con json-Footnote-16728128
Node: Errori ed Eccezioni6728153
Ref: tutorial/errors doc6728265
Ref: 20596728265
Ref: tutorial/errors errors-and-exceptions6728265
Ref: 205a6728265
Ref: tutorial/errors translation-repo6728265
Ref: 205b6728265
Ref: tutorial/errors tut-errors6728265
Ref: 205c6728265
Node: Errori di Sintassi6728856
Ref: tutorial/errors syntax-errors6728948
Ref: 205d6728948
Ref: tutorial/errors tut-syntaxerrors6728948
Ref: 205e6728948
Node: Eccezioni6729774
Ref: tutorial/errors exceptions6729899
Ref: 205f6729899
Ref: tutorial/errors tut-exceptions6729899
Ref: 20606729899
Node: Gestione delle Eccezioni6731984
Ref: tutorial/errors handling-exceptions6732110
Ref: 20616732110
Ref: tutorial/errors tut-handling6732110
Ref: 1fe36732110
Node: Sollevare Eccezioni6739009
Ref: tutorial/errors raising-exceptions6739154
Ref: 20626739154
Ref: tutorial/errors tut-raising6739154
Ref: 20636739154
Node: Collegamento delle Eccezioni6740475
Ref: tutorial/errors exception-chaining6740628
Ref: 20646740628
Ref: tutorial/errors tut-exception-chaining6740628
Ref: 20656740628
Node: Eccezioni Definite dall’Utente6742961
Ref: tutorial/errors tut-userexceptions6743127
Ref: 20666743127
Ref: tutorial/errors user-defined-exceptions6743127
Ref: 20676743127
Node: Definizione di Azioni di Pulizia6744022
Ref: tutorial/errors defining-clean-up-actions6744189
Ref: 20686744189
Ref: tutorial/errors tut-cleanup6744189
Ref: 20696744189
Ref: Definizione di Azioni di Pulizia-Footnote-16748117
Ref: Definizione di Azioni di Pulizia-Footnote-26748159
Node: Azioni di Pulizia Predefinite6748201
Ref: tutorial/errors predefined-clean-up-actions6748390
Ref: 206a6748390
Ref: tutorial/errors tut-cleanup-with6748390
Ref: 206b6748390
Node: Sollevare e Gestire Eccezioni Multiple e Non Correlate6749613
Ref: tutorial/errors raising-and-handling-multiple-unrelated-exceptions6749802
Ref: 206c6749802
Ref: tutorial/errors tut-exception-groups6749802
Ref: 206d6749802
Node: Arricchire le Eccezioni con Note6753498
Ref: tutorial/errors enriching-exceptions-with-notes6753649
Ref: 206e6753649
Ref: tutorial/errors tut-exception-notes6753649
Ref: 206f6753649
Node: Classi6756606
Ref: tutorial/classes doc6756744
Ref: 20706756744
Ref: tutorial/classes classes6756744
Ref: 20716756744
Ref: tutorial/classes translation-repo6756744
Ref: 20726756744
Ref: tutorial/classes tut-classes6756744
Ref: 1feb6756744
Node: Una parola su nomi e oggetti6759455
Ref: tutorial/classes a-word-about-names-and-objects6759573
Ref: 20746759573
Ref: tutorial/classes tut-object6759573
Ref: 20756759573
Node: Visibilità e spazi dei nomi in Python6760598
Ref: tutorial/classes python-scopes-and-namespaces6760755
Ref: 20766760755
Ref: tutorial/classes tut-scopes6760755
Ref: 202a6760755
Ref: Visibilità e spazi dei nomi in Python-Footnote-16767670
Node: Esempio di visibilità e spazi dei nomi6768054
Ref: tutorial/classes scopes-and-namespaces-example6768168
Ref: 20786768168
Ref: tutorial/classes tut-scopeexample6768168
Ref: 20796768168
Node: Una prima occhiata alle classi6769609
Ref: tutorial/classes a-first-look-at-classes6769756
Ref: 207a6769756
Ref: tutorial/classes tut-firstclasses6769756
Ref: 20066769756
Node: Sintassi della definizione di classe6770084
Ref: tutorial/classes class-definition-syntax6770216
Ref: 207b6770216
Ref: tutorial/classes tut-classdefinition6770216
Ref: 207c6770216
Node: Oggetti della Classe6772014
Ref: tutorial/classes class-objects6772170
Ref: 207d6772170
Ref: tutorial/classes tut-classobjects6772170
Ref: 207e6772170
Node: Oggetti Istanza6774610
Ref: tutorial/classes instance-objects6774744
Ref: 20806774744
Ref: tutorial/classes tut-instanceobjects6774744
Ref: 20816774744
Node: Oggetti Metodo6776116
Ref: tutorial/classes method-objects6776259
Ref: 20826776259
Ref: tutorial/classes tut-methodobjects6776259
Ref: 20836776259
Node: Variabili di Classe e Istanza6778242
Ref: tutorial/classes class-and-instance-variables6778361
Ref: 20846778361
Ref: tutorial/classes tut-class-and-instance-variables6778361
Ref: 20856778361
Node: Osservazioni Varie6780474
Ref: tutorial/classes random-remarks6780596
Ref: 20866780596
Ref: tutorial/classes tut-remarks6780596
Ref: 20876780596
Node: Ereditarietà6784822
Ref: tutorial/classes inheritance6784931
Ref: 20886784931
Ref: tutorial/classes tut-inheritance6784931
Ref: 20896784931
Node: Ereditarietà Multipla6788043
Ref: tutorial/classes multiple-inheritance6788115
Ref: 208a6788115
Ref: tutorial/classes tut-multiple6788115
Ref: 208b6788115
Node: Variabili Private6790295
Ref: tutorial/classes private-variables6790404
Ref: 208c6790404
Ref: tutorial/classes tut-private6790404
Ref: 20736790404
Node: Varie ed Eventuali6793417
Ref: tutorial/classes odds-and-ends6793522
Ref: 208e6793522
Ref: tutorial/classes tut-odds6793522
Ref: 208f6793522
Node: Iteratori6794694
Ref: tutorial/classes iterators6794792
Ref: 20926794792
Ref: tutorial/classes tut-iterators6794792
Ref: 20936794792
Node: Generatori6797196
Ref: tutorial/classes generators6797301
Ref: 20956797301
Ref: tutorial/classes tut-generators6797301
Ref: 20966797301
Node: Espressioni di Generatore6798915
Ref: tutorial/classes generator-expressions6799002
Ref: 20996799002
Ref: tutorial/classes tut-genexps6799002
Ref: 209a6799002
Node: Breve Panoramica della Libreria Standard6800103
Ref: tutorial/stdlib doc6800269
Ref: 209b6800269
Ref: tutorial/stdlib brief-tour-of-the-standard-library6800269
Ref: 209c6800269
Ref: tutorial/stdlib translation-repo6800269
Ref: 209d6800269
Ref: tutorial/stdlib tut-brieftour6800269
Ref: 209e6800269
Node: Interfaccia del Sistema Operativo6800752
Ref: tutorial/stdlib operating-system-interface6800896
Ref: 209f6800896
Ref: tutorial/stdlib tut-os-interface6800896
Ref: 20a06800896
Node: Metacaratteri nei Nomfile6802202
Ref: tutorial/stdlib file-wildcards6802387
Ref: 20a16802387
Ref: tutorial/stdlib tut-file-wildcards6802387
Ref: 20a26802387
Node: Argomenti dalla Linea di Comando6802687
Ref: tutorial/stdlib command-line-arguments6802911
Ref: 20a36802911
Ref: tutorial/stdlib tut-command-line-arguments6802911
Ref: 20a46802911
Node: Reindirizzamento dell’Uscita degli Errori e Terminazione del Programma6804158
Ref: tutorial/stdlib error-output-redirection-and-program-termination6804385
Ref: 20a56804385
Ref: tutorial/stdlib tut-stderr6804385
Ref: 20a66804385
Node: Pattern Matching di Stringhe6804962
Ref: tutorial/stdlib string-pattern-matching6805167
Ref: 20a76805167
Ref: tutorial/stdlib tut-string-pattern-matching6805167
Ref: 20a86805167
Node: Matematica6805880
Ref: tutorial/stdlib mathematics6806031
Ref: 20a96806031
Ref: tutorial/stdlib tut-mathematics6806031
Ref: 20aa6806031
Node: Accesso a Internet6807214
Ref: tutorial/stdlib internet-access6807349
Ref: 20ab6807349
Ref: tutorial/stdlib tut-internet-access6807349
Ref: 20ac6807349
Node: Date e Orari6808387
Ref: tutorial/stdlib dates-and-times6808533
Ref: 20ad6808533
Ref: tutorial/stdlib tut-dates-and-times6808533
Ref: 20ae6808533
Node: Compressione dei Dati6809391
Ref: tutorial/stdlib data-compression6809548
Ref: 20af6809548
Ref: tutorial/stdlib tut-data-compression6809548
Ref: 20b06809548
Node: Misurazione delle Prestazioni6810094
Ref: tutorial/stdlib performance-measurement6810263
Ref: 20b16810263
Ref: tutorial/stdlib tut-performance-measurement6810263
Ref: 20b26810263
Node: Controllo della Qualità6811241
Ref: tutorial/stdlib quality-control6811405
Ref: 20b36811405
Ref: tutorial/stdlib tut-quality-control6811405
Ref: 20b46811405
Node: Batterie Incluse6813016
Ref: tutorial/stdlib batteries-included6813142
Ref: 20b56813142
Ref: tutorial/stdlib tut-batteries-included6813142
Ref: 20b66813142
Ref: Batterie Incluse-Footnote-16815072
Node: Giro Breve della Libreria Standard — Parte II6815131
Ref: tutorial/stdlib2 doc6815320
Ref: 20b76815320
Ref: tutorial/stdlib2 brief-tour-of-the-standard-library-part-ii6815320
Ref: 20b86815320
Ref: tutorial/stdlib2 translation-repo6815320
Ref: 20b96815320
Ref: tutorial/stdlib2 tut-brieftourtwo6815320
Ref: 20ba6815320
Node: Formattazione dell’Output6815831
Ref: tutorial/stdlib2 output-formatting6815961
Ref: 20bb6815961
Ref: tutorial/stdlib2 tut-output-formatting6815961
Ref: 20bc6815961
Node: Templating6818217
Ref: tutorial/stdlib2 templating6818391
Ref: 20bd6818391
Ref: tutorial/stdlib2 tut-templating6818391
Ref: 20be6818391
Node: Lavorare con Layout Binari dei Dati6821150
Ref: tutorial/stdlib2 tut-binary-formats6821315
Ref: 20c16821315
Ref: tutorial/stdlib2 working-with-binary-data-record-layouts6821315
Ref: 20c26821315
Node: Multi-threading<2>6822513
Ref: tutorial/stdlib2 multi-threading6822675
Ref: 20c36822675
Ref: tutorial/stdlib2 tut-multi-threading6822675
Ref: 20c46822675
Node: Logging6824774
Ref: tutorial/stdlib2 logging6824919
Ref: 20c56824919
Ref: tutorial/stdlib2 tut-logging6824919
Ref: 20c66824919
Node: Riferimenti Deboli6826235
Ref: tutorial/stdlib2 tut-weak-references6826394
Ref: 20cc6826394
Ref: tutorial/stdlib2 weak-references6826394
Ref: 20cd6826394
Node: Strumenti per Lavorare con Liste6828244
Ref: tutorial/stdlib2 tools-for-working-with-lists6828429
Ref: 20ce6828429
Ref: tutorial/stdlib2 tut-list-tools6828429
Ref: 20cf6828429
Node: Decimal Floating-Point Arithmetic6830961
Ref: tutorial/stdlib2 decimal-floating-point-arithmetic6831119
Ref: 20d06831119
Ref: tutorial/stdlib2 tut-decimal-fp6831119
Ref: 20d16831119
Node: Ambienti Virtuali e Pacchetti6833215
Ref: tutorial/venv doc6833373
Ref: 20d26833373
Ref: tutorial/venv translation-repo6833373
Ref: 20d36833373
Ref: tutorial/venv tut-venv6833373
Ref: 20d46833373
Ref: tutorial/venv virtual-environments-and-packages6833373
Ref: 20d56833373
Node: Introduzione6833541
Ref: tutorial/venv introduction6833658
Ref: 20d66833658
Node: Creazione di Ambienti Virtuali6835196
Ref: tutorial/venv creating-virtual-environments6835352
Ref: 20d86835352
Node: Gestione dei Pacchetti con pip6837487
Ref: tutorial/venv managing-packages-with-pip6837622
Ref: 20d96837622
Ref: Gestione dei Pacchetti con pip-Footnote-16841726
Ref: Gestione dei Pacchetti con pip-Footnote-26841751
Node: E adesso?6841829
Ref: tutorial/whatnow doc6842001
Ref: 20da6842001
Ref: tutorial/whatnow translation-repo6842001
Ref: 20db6842001
Ref: tutorial/whatnow tut-whatnow6842001
Ref: 20dc6842001
Ref: tutorial/whatnow what-now6842001
Ref: 20dd6842001
Ref: E adesso?-Footnote-16845530
Node: Editing dell’input interattivo e sostituzione della history6845693
Ref: tutorial/interactive doc6845884
Ref: 20df6845884
Ref: tutorial/interactive interactive-input-editing-and-history-substitution6845884
Ref: 20e06845884
Ref: tutorial/interactive translation-repo6845884
Ref: 20e16845884
Ref: tutorial/interactive tut-interacting6845884
Ref: 1fb36845884
Ref: Editing dell’input interattivo e sostituzione della history-Footnote-16846541
Node: Completamento con il tasto Tab e modifica della history6846602
Ref: tutorial/interactive tab-completion-and-history-editing6846804
Ref: 20e26846804
Ref: tutorial/interactive tut-keybindings6846804
Ref: 20e36846804
Node: Alternative all’interprete interattivo6847798
Ref: tutorial/interactive alternatives-to-the-interactive-interpreter6848000
Ref: 20e46848000
Ref: tutorial/interactive tut-commentary6848000
Ref: 20e56848000
Ref: Alternative all’interprete interattivo-Footnote-16848925
Ref: Alternative all’interprete interattivo-Footnote-26848954
Node: Floating-Point Arithmetic Issues and Limitations6848995
Ref: tutorial/floatingpoint doc6849186
Ref: 20e76849186
Ref: tutorial/floatingpoint floating-point-arithmetic-issues-and-limitations6849186
Ref: 20e86849186
Ref: tutorial/floatingpoint translation-repo6849186
Ref: 20e96849186
Ref: tutorial/floatingpoint tut-fp-issues6849186
Ref: 20ea6849186
Ref: Floating-Point Arithmetic Issues and Limitations-Footnote-16859389
Ref: Floating-Point Arithmetic Issues and Limitations-Footnote-26859467
Node: Errore di Rappresentazione6859518
Ref: tutorial/floatingpoint representation-error6859629
Ref: 20ed6859629
Ref: tutorial/floatingpoint tut-fp-error6859629
Ref: 20ee6859629
Node: Appendice6863165
Ref: tutorial/appendix doc6863286
Ref: 20ef6863286
Ref: tutorial/appendix appendix6863286
Ref: 20f06863286
Ref: tutorial/appendix translation-repo6863286
Ref: 20f16863286
Ref: tutorial/appendix tut-appendix6863286
Ref: 20f26863286
Node: Modalità Interattiva<2>6863378
Ref: tutorial/appendix interactive-mode6863448
Ref: 20f36863448
Ref: tutorial/appendix tut-interac6863448
Ref: 4956863448
Node: Gestione degli Errori6864722
Ref: tutorial/appendix error-handling6864837
Ref: 20f46864837
Ref: tutorial/appendix tut-error6864837
Ref: 20f56864837
Ref: Gestione degli Errori-Footnote-16866073
Node: Script Eseguibili Python6866143
Ref: tutorial/appendix executable-python-scripts6866295
Ref: 20f66866295
Ref: tutorial/appendix tut-scripts6866295
Ref: 1fbb6866295
Node: Il File di Avvio Interattivo6867446
Ref: tutorial/appendix the-interactive-startup-file6867606
Ref: 20f76867606
Ref: tutorial/appendix tut-startup6867606
Ref: 20f86867606
Node: I Moduli di Personalizzazione6869071
Ref: tutorial/appendix the-customization-modules6869198
Ref: 20f96869198
Ref: tutorial/appendix tut-customize6869198
Ref: 20fa6869198
Node: Python Setup and Usage6870182
Ref: using/index doc6870309
Ref: 20fb6870309
Ref: using/index python-setup-and-usage6870309
Ref: 20fc6870309
Ref: using/index translation-repo6870309
Ref: 20fd6870309
Ref: using/index using-index6870309
Ref: 20fe6870309
Node: Command line and environment<2>6870830
Ref: using/cmdline doc6870959
Ref: 20ff6870959
Ref: using/cmdline command-line-and-environment6870959
Ref: 21006870959
Ref: using/cmdline using-on-general6870959
Ref: 1d8f6870959
Node: Command line6871342
Ref: using/cmdline command-line6871452
Ref: 21026871452
Ref: using/cmdline using-on-cmdline6871452
Ref: 12096871452
Node: Interface options6871838
Ref: using/cmdline interface-options6871928
Ref: 21036871928
Ref: using/cmdline using-on-interface-options6871928
Ref: 21046871928
Ref: using/cmdline cmdoption-c6873403
Ref: 1a86873403
Ref: using/cmdline cmdoption-m6874067
Ref: 23c6874067
Ref: using/cmdline cmdarg-dash6876471
Ref: 21056876471
Ref: using/cmdline cmdarg-script6876891
Ref: 21066876891
Ref: Interface options-Footnote-16878763
Node: Generic options6878805
Ref: using/cmdline generic-options6878925
Ref: 21076878925
Ref: using/cmdline using-on-generic-options6878925
Ref: 21086878925
Ref: using/cmdline cmdoption-06878974
Ref: 162f6878974
Ref: using/cmdline cmdoption-h6878989
Ref: 21096878989
Ref: using/cmdline cmdoption-help6879004
Ref: 8076879004
Ref: using/cmdline cmdoption-help-env6879139
Ref: 8096879139
Ref: using/cmdline cmdoption-help-xoptions6879280
Ref: 80a6879280
Ref: using/cmdline cmdoption-help-all6879429
Ref: 80b6879429
Ref: using/cmdline cmdoption-V6879531
Ref: 49c6879531
Ref: using/cmdline cmdoption-version6879546
Ref: f196879546
Node: Miscellaneous options6879888
Ref: using/cmdline miscellaneous-options6880008
Ref: 210a6880008
Ref: using/cmdline using-on-misc-options6880008
Ref: 120a6880008
Ref: using/cmdline cmdoption-b6880069
Ref: 7fa6880069
Ref: using/cmdline cmdoption-B6880490
Ref: 15d46880490
Ref: using/cmdline cmdoption-check-hash-based-pycs6880652
Ref: 210b6880652
Ref: using/cmdline cmdoption-d6881346
Ref: 210c6881346
Ref: using/cmdline cmdoption-E6881579
Ref: b586881579
Ref: using/cmdline cmdoption-i6881803
Ref: 16e26881803
Ref: using/cmdline cmdoption-I6882440
Ref: b596882440
Ref: using/cmdline cmdoption-O6882892
Ref: 18c6882892
Ref: using/cmdline cmdoption-OO6883285
Ref: fb76883285
Ref: using/cmdline cmdoption-P6883595
Ref: 7c26883595
Ref: using/cmdline cmdoption-q6884268
Ref: 17656884268
Ref: using/cmdline cmdoption-R6884400
Ref: 1e606884400
Ref: using/cmdline cmdoption-s6885489
Ref: 15966885489
Ref: using/cmdline cmdoption-S6885730
Ref: 13b06885730
Ref: using/cmdline cmdoption-u6886047
Ref: 1d756886047
Ref: using/cmdline cmdoption-v6886328
Ref: 162c6886328
Ref: using/cmdline using-on-warnings6886838
Ref: 21126886838
Ref: using/cmdline cmdoption-W6886838
Ref: ac76886838
Ref: using/cmdline cmdoption-x6889350
Ref: 21146889350
Ref: using/cmdline cmdoption-X6889507
Ref: 16f6889507
Ref: Miscellaneous options-Footnote-16898386
Ref: Miscellaneous options-Footnote-26898428
Ref: Miscellaneous options-Footnote-36898470
Ref: Miscellaneous options-Footnote-46898512
Ref: Miscellaneous options-Footnote-56898554
Ref: Miscellaneous options-Footnote-66898596
Ref: Miscellaneous options-Footnote-76898638
Ref: Miscellaneous options-Footnote-86898680
Node: Controlling color6898712
Ref: using/cmdline controlling-color6898808
Ref: 211b6898808
Ref: using/cmdline using-on-controlling-color6898808
Ref: 1b76898808
Ref: Controlling color-Footnote-16899866
Ref: Controlling color-Footnote-26899899
Node: Environment variables6899929
Ref: using/cmdline environment-variables6900039
Ref: 211c6900039
Ref: using/cmdline using-on-envvars6900039
Ref: 8086900039
Ref: using/cmdline envvar-PYTHONHOME6900332
Ref: 3f06900332
Ref: using/cmdline envvar-PYTHONPATH6900938
Ref: 121f6900938
Ref: using/cmdline envvar-PYTHONSAFEPATH6902004
Ref: 7c36902004
Ref: using/cmdline envvar-PYTHONPLATLIBDIR6902239
Ref: 1d0b6902239
Ref: using/cmdline envvar-PYTHONSTARTUP6902411
Ref: 1b86902411
Ref: using/cmdline envvar-PYTHONOPTIMIZE6903101
Ref: 210e6903101
Ref: using/cmdline envvar-PYTHONBREAKPOINT6903339
Ref: cd46903339
Ref: using/cmdline envvar-PYTHONDEBUG6903960
Ref: 210d6903960
Ref: using/cmdline envvar-PYTHONINSPECT6904305
Ref: 16e16904305
Ref: using/cmdline envvar-PYTHONUNBUFFERED6904938
Ref: 1d766904938
Ref: using/cmdline envvar-PYTHONVERBOSE6905089
Ref: 21116905089
Ref: using/cmdline envvar-PYTHONCASEOK6905328
Ref: b576905328
Ref: using/cmdline envvar-PYTHONDONTWRITEBYTECODE6905488
Ref: 15d56905488
Ref: using/cmdline envvar-PYTHONPYCACHEPREFIX6905733
Ref: b9d6905733
Ref: using/cmdline envvar-PYTHONHASHSEED6906076
Ref: 127f6906076
Ref: using/cmdline envvar-PYTHONINTMAXSTRDIGITS6906762
Ref: 1b226906762
Ref: using/cmdline envvar-PYTHONIOENCODING6907002
Ref: 120c6907002
Ref: using/cmdline envvar-PYTHONNOUSERSITE6907840
Ref: 15976907840
Ref: using/cmdline envvar-PYTHONUSERBASE6908087
Ref: 15956908087
Ref: using/cmdline envvar-PYTHONEXECUTABLE6908441
Ref: 21216908441
Ref: using/cmdline envvar-PYTHONWARNINGS6908651
Ref: da56908651
Ref: using/cmdline envvar-PYTHONFAULTHANDLER6909639
Ref: 12876909639
Ref: using/cmdline envvar-PYTHONTRACEMALLOC6910090
Ref: 21166910090
Ref: using/cmdline envvar-PYTHONPROFILEIMPORTTIME6910661
Ref: cef6910661
Ref: using/cmdline envvar-PYTHONASYNCIODEBUG6911148
Ref: 21226911148
Ref: using/cmdline envvar-PYTHONMALLOC6911360
Ref: e606911360
Ref: using/cmdline envvar-PYTHONMALLOCSTATS6912825
Ref: 1f1f6912825
Ref: using/cmdline envvar-PYTHONLEGACYWINDOWSFSENCODING6913445
Ref: 33f6913445
Ref: using/cmdline envvar-PYTHONLEGACYWINDOWSSTDIO6913982
Ref: e576913982
Ref: using/cmdline envvar-PYTHONCOERCECLOCALE6914455
Ref: cce6914455
Ref: using/cmdline envvar-PYTHONDEVMODE6917185
Ref: ce96917185
Ref: using/cmdline envvar-PYTHONUTF86917532
Ref: cd16917532
Ref: using/cmdline envvar-PYTHONWARNDEFAULTENCODING6917828
Ref: 9c16917828
Ref: using/cmdline envvar-PYTHONNODEBUGRANGES6918132
Ref: 7d46918132
Ref: using/cmdline envvar-PYTHONPERFSUPPORT6918601
Ref: 69a6918601
Ref: using/cmdline envvar-PYTHON_PERF_JIT_SUPPORT6919013
Ref: 4b06919013
Ref: using/cmdline envvar-PYTHON_DISABLE_REMOTE_DEBUG6919464
Ref: 16e6919464
Ref: using/cmdline envvar-PYTHON_CPU_COUNT6919932
Ref: 51f6919932
Ref: using/cmdline envvar-PYTHON_FROZEN_MODULES6920233
Ref: 4ae6920233
Ref: using/cmdline envvar-PYTHON_COLORS6920878
Ref: 4766920878
Ref: using/cmdline envvar-PYTHON_BASIC_REPL6921145
Ref: 1b66921145
Ref: using/cmdline envvar-PYTHON_HISTORY6921454
Ref: 4b16921454
Ref: using/cmdline envvar-PYTHON_GIL6921705
Ref: 49b6921705
Ref: using/cmdline envvar-PYTHON_THREAD_INHERIT_CONTEXT6922143
Ref: 18506922143
Ref: using/cmdline envvar-PYTHON_CONTEXT_AWARE_WARNINGS6922613
Ref: 18436922613
Ref: using/cmdline envvar-PYTHON_JIT6923009
Ref: 44d6923009
Ref: using/cmdline envvar-PYTHON_TLBC6923262
Ref: 21196923262
Ref: Environment variables-Footnote-16923684
Ref: Environment variables-Footnote-26923726
Ref: Environment variables-Footnote-36923768
Ref: Environment variables-Footnote-46923810
Ref: Environment variables-Footnote-56923852
Node: Debug-mode variables6923894
Ref: using/cmdline debug-mode-variables6923972
Ref: 212a6923972
Ref: using/cmdline envvar-PYTHONDUMPREFS6924031
Ref: ba06924031
Ref: using/cmdline envvar-PYTHONDUMPREFSFILE6924274
Ref: 1c276924274
Ref: using/cmdline envvar-PYTHON_PRESITE6924630
Ref: 21186924630
Node: Using Python on Unix platforms6925375
Ref: using/unix doc6925529
Ref: 212b6925529
Ref: using/unix translation-repo6925529
Ref: 212c6925529
Ref: using/unix using-on-unix6925529
Ref: 212d6925529
Ref: using/unix using-python-on-unix-platforms6925529
Ref: 212e6925529
Node: Getting and installing the latest version of Python6925758
Ref: using/unix getting-and-installing-the-latest-version-of-python6925900
Ref: 212f6925900
Node: On Linux6926067
Ref: using/unix on-linux6926194
Ref: 21306926194
Node: Installing IDLE6927129
Ref: using/unix installing-idle6927189
Ref: 21316927189
Ref: using/unix installing-idle-on-linux6927189
Ref: 21326927189
Node: On FreeBSD and OpenBSD6927633
Ref: using/unix on-freebsd-and-openbsd6927760
Ref: 21336927760
Node: Building Python6928250
Ref: using/unix building-python6928431
Ref: 21346928431
Ref: using/unix building-python-on-unix6928431
Ref: 10f86928431
Ref: Building Python-Footnote-16929429
Ref: Building Python-Footnote-26929497
Ref: Building Python-Footnote-36929546
Ref: Building Python-Footnote-46929609
Node: Python-related paths and files6929672
Ref: using/unix python-related-paths-and-files6929815
Ref: 21376929815
Node: Miscellaneous6931358
Ref: using/unix miscellaneous6931500
Ref: 213a6931500
Node: Custom OpenSSL6932058
Ref: using/unix custom-openssl6932161
Ref: 213b6932161
Ref: using/unix unix-custom-openssl6932161
Ref: 213c6932161
Node: Configure Python6933781
Ref: using/configure doc6933927
Ref: 213d6933927
Ref: using/configure configure-python6933927
Ref: 213e6933927
Ref: using/configure translation-repo6933927
Ref: 213f6933927
Node: Build Requirements6934099
Ref: using/configure build-requirements6934194
Ref: 21356934194
Ref: using/configure id16934194
Ref: 21406934194
Ref: Build Requirements-Footnote-16935137
Ref: Build Requirements-Footnote-26935180
Ref: Build Requirements-Footnote-36935263
Ref: Build Requirements-Footnote-46935310
Ref: Build Requirements-Footnote-56935367
Ref: Build Requirements-Footnote-66935409
Node: Requirements for optional modules6935451
Ref: using/configure optional-module-requirements6935539
Ref: 21416935539
Ref: using/configure requirements-for-optional-modules6935539
Ref: 21426935539
Ref: Requirements for optional modules-Footnote-16941067
Ref: Requirements for optional modules-Footnote-26941105
Ref: Requirements for optional modules-Footnote-36941144
Ref: Requirements for optional modules-Footnote-46941176
Ref: Requirements for optional modules-Footnote-56941233
Ref: Requirements for optional modules-Footnote-66941394
Ref: Requirements for optional modules-Footnote-76941455
Ref: Requirements for optional modules-Footnote-86941497
Ref: Requirements for optional modules-Footnote-96941598
Ref: Requirements for optional modules-Footnote-106941642
Ref: Requirements for optional modules-Footnote-116941767
Ref: Requirements for optional modules-Footnote-126941822
Ref: Requirements for optional modules-Footnote-136942025
Ref: Requirements for optional modules-Footnote-146942063
Ref: Requirements for optional modules-Footnote-156942270
Ref: Requirements for optional modules-Footnote-166942299
Ref: Requirements for optional modules-Footnote-176942334
Ref: Requirements for optional modules-Footnote-186942364
Ref: Requirements for optional modules-Footnote-196942406
Ref: Requirements for optional modules-Footnote-206942497
Node: Generated files6942534
Ref: using/configure generated-files6942655
Ref: 21476942655
Node: configure script6943120
Ref: using/configure configure-script6943188
Ref: 21486943188
Ref: configure script-Footnote-16944040
Ref: configure script-Footnote-26944082
Ref: configure script-Footnote-36944128
Node: Configure Options6944190
Ref: using/configure configure-options6944312
Ref: 21366944312
Ref: using/configure id126944312
Ref: 21496944312
Node: General Options6944876
Ref: using/configure general-options6944972
Ref: 214a6944972
Ref: using/configure cmdoption-enable-loadable-sqlite-extensions6945021
Ref: 214b6945021
Ref: using/configure cmdoption-disable-ipv66945340
Ref: 214c6945340
Ref: using/configure cmdoption-enable-big-digits6945469
Ref: 9546945469
Ref: using/configure cmdoption-with-suffix6945754
Ref: 214d6945754
Ref: using/configure cmdoption-with-tzpath6946224
Ref: 214e6946224
Ref: using/configure cmdoption-without-decimal-contextvar6946653
Ref: 21516946653
Ref: using/configure cmdoption-with-dbmliborder6946985
Ref: 21536946985
Ref: using/configure cmdoption-without-c-locale-coercion6947268
Ref: 21546947268
Ref: using/configure cmdoption-with-platlibdir6947511
Ref: 21556947511
Ref: using/configure cmdoption-with-wheel-pkg-dir6947734
Ref: a8f6947734
Ref: using/configure cmdoption-with-pkg-config6948157
Ref: 21566948157
Ref: using/configure cmdoption-enable-pystats6948513
Ref: 1b206948513
Ref: using/configure free-threading-build6950824
Ref: 21576950824
Ref: using/configure cmdoption-disable-gil6950824
Ref: 49a6950824
Ref: using/configure cmdoption-enable-experimental-jit6951162
Ref: 44e6951162
Ref: using/configure cmdoption-arg-PKG_CONFIG6952349
Ref: 21586952349
Ref: using/configure cmdoption-arg-PKG_CONFIG_LIBDIR6952413
Ref: 21596952413
Ref: using/configure cmdoption-arg-PKG_CONFIG_PATH6952444
Ref: 215a6952444
Ref: General Options-Footnote-16952541
Node: C compiler options6952583
Ref: using/configure c-compiler-options6952702
Ref: 215b6952702
Ref: using/configure cmdoption-arg-CC6952757
Ref: 215c6952757
Ref: using/configure cmdoption-arg-CFLAGS6952799
Ref: 215d6952799
Ref: using/configure cmdoption-arg-CPP6952843
Ref: 215e6952843
Ref: using/configure cmdoption-arg-CPPFLAGS6952890
Ref: 215f6952890
Node: Linker options6952967
Ref: using/configure linker-options6953107
Ref: 21606953107
Ref: using/configure cmdoption-arg-LDFLAGS6953154
Ref: 21616953154
Ref: using/configure cmdoption-arg-LIBS6953228
Ref: 21626953228
Ref: using/configure cmdoption-arg-MACHDEP6953308
Ref: 21636953308
Node: Options for third-party dependencies6953377
Ref: using/configure configure-options-for-dependencies6953518
Ref: 21466953518
Ref: using/configure options-for-third-party-dependencies6953518
Ref: 21646953518
Ref: using/configure cmdoption-arg-BZIP2_CFLAGS6953633
Ref: 21656953633
Ref: using/configure cmdoption-arg-BZIP2_LIBS6953659
Ref: 21666953659
Ref: using/configure cmdoption-arg-CURSES_CFLAGS6953814
Ref: 21676953814
Ref: using/configure cmdoption-arg-CURSES_LIBS6953841
Ref: 21686953841
Ref: using/configure cmdoption-arg-GDBM_CFLAGS6954011
Ref: 21696954011
Ref: using/configure cmdoption-arg-GDBM_LIBS6954036
Ref: 216a6954036
Ref: using/configure cmdoption-arg-LIBEDIT_CFLAGS6954109
Ref: 216b6954109
Ref: using/configure cmdoption-arg-LIBEDIT_LIBS6954137
Ref: 216c6954137
Ref: using/configure cmdoption-arg-LIBFFI_CFLAGS6954286
Ref: 216d6954286
Ref: using/configure cmdoption-arg-LIBFFI_LIBS6954313
Ref: 216e6954313
Ref: using/configure cmdoption-arg-LIBMPDEC_CFLAGS6954458
Ref: 216f6954458
Ref: using/configure cmdoption-arg-LIBMPDEC_LIBS6954487
Ref: 21706954487
Ref: using/configure cmdoption-arg-LIBLZMA_CFLAGS6954762
Ref: 21716954762
Ref: using/configure cmdoption-arg-LIBLZMA_LIBS6954790
Ref: 21726954790
Ref: using/configure cmdoption-arg-LIBREADLINE_CFLAGS6954935
Ref: 21736954935
Ref: using/configure cmdoption-arg-LIBREADLINE_LIBS6954967
Ref: 21746954967
Ref: using/configure cmdoption-arg-LIBSQLITE3_CFLAGS6955124
Ref: 21756955124
Ref: using/configure cmdoption-arg-LIBSQLITE3_LIBS6955155
Ref: 21766955155
Ref: using/configure cmdoption-arg-LIBUUID_CFLAGS6955309
Ref: 21776955309
Ref: using/configure cmdoption-arg-LIBUUID_LIBS6955337
Ref: 21786955337
Ref: using/configure cmdoption-arg-LIBZSTD_CFLAGS6955483
Ref: 21796955483
Ref: using/configure cmdoption-arg-LIBZSTD_LIBS6955511
Ref: 217a6955511
Ref: using/configure cmdoption-arg-PANEL_CFLAGS6955697
Ref: 217b6955697
Ref: using/configure cmdoption-arg-PANEL_LIBS6955723
Ref: 217c6955723
Ref: using/configure cmdoption-arg-TCLTK_CFLAGS6955968
Ref: 217d6955968
Ref: using/configure cmdoption-arg-TCLTK_LIBS6955994
Ref: 217e6955994
Ref: using/configure cmdoption-arg-ZLIB_CFLAGS6956092
Ref: 217f6956092
Ref: using/configure cmdoption-arg-ZLIB_LIBS6956117
Ref: 21806956117
Node: WebAssembly Options6956259
Ref: using/configure webassembly-options6956401
Ref: 21816956401
Ref: using/configure cmdoption-enable-wasm-dynamic-linking6956458
Ref: 1ba66956458
Ref: using/configure cmdoption-enable-wasm-pthreads6956733
Ref: 1b756956733
Node: Install Options6956839
Ref: using/configure install-options6956964
Ref: 21826956964
Ref: using/configure cmdoption-prefix6957013
Ref: 21386957013
Ref: using/configure cmdoption-exec-prefix6957331
Ref: 21396957331
Ref: using/configure cmdoption-disable-test-modules6957543
Ref: a8e6957543
Ref: using/configure cmdoption-with-ensurepip6957771
Ref: 21836957771
Node: Performance options6958154
Ref: using/configure performance-options6958278
Ref: 21846958278
Ref: using/configure cmdoption-enable-optimizations6958534
Ref: a646958534
Ref: using/configure envvar-PROFILE_TASK6959542
Ref: 1a666959542
Ref: using/configure cmdoption-with-lto6959869
Ref: 9536959869
Ref: using/configure cmdoption-enable-bolt6960393
Ref: 21856960393
Ref: using/configure cmdoption-arg-BOLT_APPLY_FLAGS6961460
Ref: 21866961460
Ref: using/configure cmdoption-arg-BOLT_INSTRUMENT_FLAGS6961596
Ref: 21876961596
Ref: using/configure cmdoption-with-computed-gotos6961724
Ref: 21886961724
Ref: using/configure cmdoption-with-tail-call-interp6961856
Ref: 1726961856
Ref: using/configure cmdoption-without-mimalloc6962262
Ref: 21896962262
Ref: using/configure cmdoption-without-pymalloc6962438
Ref: 218a6962438
Ref: using/configure cmdoption-without-doc-strings6962634
Ref: 218b6962634
Ref: using/configure cmdoption-enable-profiling6962931
Ref: 218c6962931
Ref: using/configure cmdoption-with-strict-overflow6963039
Ref: 1abb6963039
Ref: using/configure cmdoption-without-remote-debug6963194
Ref: 1706963194
Ref: using/configure c Py_REMOTE_DEBUG6963640
Ref: 218d6963640
Ref: Performance options-Footnote-16964005
Ref: Performance options-Footnote-26964065
Ref: Performance options-Footnote-36964113
Ref: Performance options-Footnote-46964187
Ref: Performance options-Footnote-56964229
Node: Python Debug Build6964271
Ref: using/configure debug-build6964393
Ref: 50a6964393
Ref: using/configure python-debug-build6964393
Ref: 218e6964393
Node: Debug options6966582
Ref: using/configure debug-options6966702
Ref: 218f6966702
Ref: using/configure cmdoption-with-pydebug6966747
Ref: 6666966747
Ref: using/configure cmdoption-with-trace-refs6966881
Ref: 6366966881
Ref: using/configure cmdoption-with-assertions6967528
Ref: 62d6967528
Ref: using/configure cmdoption-with-valgrind6967914
Ref: 21916967914
Ref: using/configure cmdoption-with-dtrace6967990
Ref: 21926967990
Ref: using/configure cmdoption-with-address-sanitizer6968160
Ref: 21936968160
Ref: using/configure cmdoption-with-memory-sanitizer6968530
Ref: 21946968530
Ref: using/configure cmdoption-with-undefined-behavior-sanitizer6968684
Ref: 21956968684
Ref: using/configure cmdoption-with-thread-sanitizer6968865
Ref: 21966968865
Node: Linker options<2>6969008
Ref: using/configure id136969127
Ref: 21976969127
Ref: using/configure cmdoption-enable-shared6969176
Ref: a656969176
Ref: using/configure cmdoption-without-static-libpython6969290
Ref: a906969290
Node: Libraries options6969478
Ref: using/configure libraries-options6969600
Ref: 21986969600
Ref: using/configure cmdoption-with-libs6969655
Ref: 21996969655
Ref: using/configure cmdoption-with-system-expat6969748
Ref: 1b156969748
Ref: using/configure cmdoption-with-system-libmpdec6969879
Ref: 6576969879
Ref: using/configure cmdoption-with-readline6970777
Ref: 21446970777
Ref: using/configure cmdoption-without-readline6971023
Ref: 219a6971023
Ref: using/configure cmdoption-with-libm6971210
Ref: 219b6971210
Ref: using/configure cmdoption-with-libc6971329
Ref: 219c6971329
Ref: using/configure cmdoption-with-openssl6971445
Ref: 219d6971445
Ref: using/configure cmdoption-with-openssl-rpath6971542
Ref: a916971542
Node: Security Options6971882
Ref: using/configure security-options6972000
Ref: 219e6972000
Ref: using/configure cmdoption-with-hash-algorithm6972053
Ref: 219f6972053
Ref: using/configure cmdoption-with-builtin-hashlib-hashes6972378
Ref: 21456972378
Ref: using/configure cmdoption-with-ssl-default-suites6972679
Ref: 21a06972679
Ref: using/configure cmdoption-disable-safety6973166
Ref: 4456973166
Ref: using/configure cmdoption-enable-slower-safety6973860
Ref: 4466973860
Ref: Security Options-Footnote-16974528
Ref: Security Options-Footnote-26974684
Ref: Security Options-Footnote-36974896
Ref: Security Options-Footnote-46975116
Ref: Security Options-Footnote-56975272
Node: macOS Options6975487
Ref: using/configure macos-options6975599
Ref: 21a16975599
Ref: using/configure cmdoption-enable-universalsdk6975670
Ref: b656975670
Ref: using/configure cmdoption-06975705
Ref: 21a26975705
Ref: using/configure cmdoption-enable-framework6975880
Ref: 21a36975880
Ref: using/configure cmdoption-16975912
Ref: 21a46975912
Ref: using/configure cmdoption-with-universal-archs6976108
Ref: 21a56976108
Ref: using/configure cmdoption-with-framework-name6976909
Ref: 21a66976909
Ref: using/configure cmdoption-with-app-store-compliance6977095
Ref: 197f6977095
Ref: using/configure cmdoption-26977136
Ref: 21a76977136
Ref: macOS Options-Footnote-16977638
Ref: macOS Options-Footnote-26977705
Node: iOS Options6977803
Ref: using/configure ios-options6977922
Ref: 21a86977922
Ref: using/configure cmdoption-36977989
Ref: 21a96977989
Ref: using/configure cmdoption-46978158
Ref: 21aa6978158
Ref: iOS Options-Footnote-16978305
Node: Cross Compiling Options6978372
Ref: using/configure cross-compiling-options6978469
Ref: 21ab6978469
Ref: using/configure cmdoption-build6978816
Ref: 21ac6978816
Ref: using/configure cmdoption-host6978921
Ref: 21ad6978921
Ref: using/configure cmdoption-with-build-python6979017
Ref: 21ae6979017
Ref: using/configure cmdoption-arg-CONFIG_SITE6979154
Ref: 21af6979154
Ref: using/configure cmdoption-arg-HOSTRUNNER6979439
Ref: 21b06979439
Node: Python Build System6979774
Ref: using/configure python-build-system6979906
Ref: 21b16979906
Node: Main files of the build system6980068
Ref: using/configure main-files-of-the-build-system6980179
Ref: 21b26980179
Node: Main build steps6980542
Ref: using/configure main-build-steps6980683
Ref: 21b36980683
Node: Main Makefile targets6981063
Ref: using/configure main-makefile-targets6981186
Ref: 21b46981186
Node: make6981423
Ref: using/configure make6981507
Ref: 21b56981507
Node: make platform6982956
Ref: using/configure make-platform6983065
Ref: 21b66983065
Node: make profile-opt6983383
Ref: using/configure make-profile-opt6983498
Ref: 21b76983498
Node: make clean6983766
Ref: using/configure make-clean6983882
Ref: 21b86983882
Node: make distclean6983942
Ref: using/configure make-distclean6984054
Ref: 21b96984054
Ref: make distclean-Footnote-16984299
Node: make install6984720
Ref: using/configure make-install6984831
Ref: 21ba6984831
Node: make test6984922
Ref: using/configure make-test6985026
Ref: 21bb6985026
Node: make ci6985385
Ref: using/configure make-ci6985494
Ref: 21bc6985494
Node: make buildbottest6985638
Ref: using/configure make-buildbottest6985752
Ref: 21bd6985752
Node: make regen-all6985950
Ref: using/configure make-regen-all6986048
Ref: 21be6986048
Node: C extensions6986349
Ref: using/configure c-extensions6986447
Ref: 21bf6986447
Node: Compiler and linker flags6988115
Ref: using/configure compiler-and-linker-flags6988221
Ref: 21c06988221
Node: Preprocessor flags6988454
Ref: using/configure preprocessor-flags6988557
Ref: 21c16988557
Ref: using/configure envvar-CONFIGURE_CPPFLAGS6988612
Ref: 21c26988612
Ref: using/configure envvar-CPPFLAGS6988777
Ref: 16c06988777
Ref: using/configure envvar-BASECPPFLAGS6989154
Ref: 21c36989154
Ref: using/configure envvar-PY_CPPFLAGS6989222
Ref: 21c46989222
Node: Compiler flags6989475
Ref: using/configure compiler-flags6989599
Ref: 21c56989599
Ref: using/configure envvar-CC6989646
Ref: 16bd6989646
Ref: using/configure envvar-CXX6989737
Ref: 21c66989737
Ref: using/configure envvar-CFLAGS6989831
Ref: 16be6989831
Ref: using/configure envvar-CFLAGS_NODIST6989889
Ref: 21c76989889
Ref: using/configure envvar-COMPILEALL_OPTS6990695
Ref: 21c86990695
Ref: using/configure envvar-EXTRA_CFLAGS6990903
Ref: 21c96990903
Ref: using/configure envvar-CONFIGURE_CFLAGS6990973
Ref: 21ca6990973
Ref: using/configure envvar-CONFIGURE_CFLAGS_NODIST6991134
Ref: 21cb6991134
Ref: using/configure envvar-BASECFLAGS6991309
Ref: 21cc6991309
Ref: using/configure envvar-OPT6991374
Ref: 21906991374
Ref: using/configure envvar-CFLAGS_ALIASING6991431
Ref: 21cd6991431
Ref: using/configure envvar-CCSHARED6991586
Ref: 21ce6991586
Ref: using/configure envvar-CFLAGSFORSHARED6991735
Ref: 21cf6991735
Ref: using/configure envvar-PY_CFLAGS6991956
Ref: 21d06991956
Ref: using/configure envvar-PY_CFLAGS_NODIST6992087
Ref: 21d16992087
Ref: using/configure envvar-PY_STDMODULE_CFLAGS6992259
Ref: 21d26992259
Ref: using/configure envvar-PY_CORE_CFLAGS6992490
Ref: 21d36992490
Ref: using/configure envvar-PY_BUILTIN_MODULE_CFLAGS6992621
Ref: 21d46992621
Ref: using/configure envvar-PURIFY6992897
Ref: 21d56992897
Ref: Compiler flags-Footnote-16993067
Node: Linker flags6993122
Ref: using/configure linker-flags6993219
Ref: 21d66993219
Ref: using/configure envvar-LINKCC6993262
Ref: 21d76993262
Ref: using/configure envvar-CONFIGURE_LDFLAGS6993423
Ref: 21d86993423
Ref: using/configure envvar-LDFLAGS_NODIST6993770
Ref: 21d96993770
Ref: using/configure envvar-CONFIGURE_LDFLAGS_NODIST6994367
Ref: 21da6994367
Ref: using/configure envvar-LDFLAGS6994544
Ref: 16bf6994544
Ref: using/configure envvar-LIBS6994890
Ref: 21db6994890
Ref: using/configure envvar-LDSHARED6995041
Ref: 21dc6995041
Ref: using/configure envvar-BLDSHARED6995165
Ref: 21dd6995165
Ref: using/configure envvar-PY_LDFLAGS6995310
Ref: 21de6995310
Ref: using/configure envvar-PY_LDFLAGS_NODIST6995402
Ref: 21df6995402
Ref: using/configure envvar-PY_CORE_LDFLAGS6995543
Ref: 21e06995543
Ref: Linker flags-Footnote-16995717
Node: Using Python on Windows6995772
Ref: using/windows doc6995909
Ref: 21e16995909
Ref: using/windows translation-repo6995909
Ref: 21e26995909
Ref: using/windows using-on-windows6995909
Ref: ca06995909
Ref: using/windows using-python-on-windows6995909
Ref: 21e36995909
Ref: using/windows pymanager6998264
Ref: 21e76998264
Ref: using/windows windows-store6998264
Ref: 1fb16998264
Ref: using/windows setting-envvars6998264
Ref: 1fb26998264
Ref: using/windows windows-path-mod6998264
Ref: 12536998264
Ref: Using Python on Windows-Footnote-16998747
Ref: Using Python on Windows-Footnote-26998789
Node: Python install manager6998844
Ref: using/windows launcher6998957
Ref: 7db6998957
Ref: using/windows python-install-manager6998957
Ref: 21e86998957
Node: Installation6999319
Ref: using/windows installation6999408
Ref: 21e96999408
Ref: Installation-Footnote-17001390
Ref: Installation-Footnote-27001445
Node: Basic use7001487
Ref: using/windows basic-use7001597
Ref: 21eb7001597
Node: Command help7005766
Ref: using/windows command-help7005880
Ref: 21ef7005880
Node: Listing runtimes7006757
Ref: using/windows listing-runtimes7006881
Ref: 21f07006881
Node: Installing runtimes7008784
Ref: using/windows installing-runtimes7008912
Ref: 21f17008912
Node: Offline installs7011106
Ref: using/windows offline-installs7011239
Ref: 21f47011239
Ref: using/windows pymanager-offline7011239
Ref: 21f27011239
Node: Uninstalling runtimes7012443
Ref: using/windows uninstalling-runtimes7012570
Ref: 21f57012570
Node: Configuration7013732
Ref: using/windows configuration7013856
Ref: 21f67013856
Ref: using/windows pymanager-config7013856
Ref: 21ed7013856
Ref: using/windows envvar-PYTHON_MANAGER_DEFAULT7015685
Ref: 21ec7015685
Ref: using/windows envvar-PYTHON_MANAGER_AUTOMATIC_INSTALL7017808
Ref: 21f37017808
Node: Shebang lines7024570
Ref: using/windows pymanager-shebang7024694
Ref: 21ee7024694
Ref: using/windows shebang-lines7024694
Ref: 21f77024694
Ref: Shebang lines-Footnote-17028062
Node: Advanced installation7028130
Ref: using/windows advanced-installation7028269
Ref: 21f87028269
Ref: using/windows pymanager-advancedinstall7028269
Ref: 21ea7028269
Ref: Advanced installation-Footnote-17032744
Ref: Advanced installation-Footnote-27032820
Ref: Advanced installation-Footnote-37032899
Ref: Advanced installation-Footnote-47032986
Node: Administrative configuration7033076
Ref: using/windows administrative-configuration7033235
Ref: 21fa7033235
Ref: using/windows pymanager-admin-config7033235
Ref: 21f97033235
Node: Installing free-threaded binaries7039450
Ref: using/windows install-freethreaded-windows7039603
Ref: 4987039603
Ref: using/windows installing-free-threaded-binaries7039603
Ref: 21fb7039603
Node: Troubleshooting7040217
Ref: using/windows pymanager-troubleshoot7040333
Ref: 21e47040333
Ref: using/windows troubleshooting7040333
Ref: 21fc7040333
Ref: Troubleshooting-Footnote-17052055
Ref: Troubleshooting-Footnote-27052106
Ref: Troubleshooting-Footnote-37052174
Node: The embeddable package7052242
Ref: using/windows the-embeddable-package7052386
Ref: 21fd7052386
Ref: using/windows windows-embeddable7052386
Ref: 21e67052386
Node: Python application7054124
Ref: using/windows python-application7054226
Ref: 21fe7054226
Node: Embedding Python7055723
Ref: using/windows embedding-python7055825
Ref: 21ff7055825
Node: The nuget org packages7056613
Ref: using/windows the-nuget-org-packages7056754
Ref: 22007056754
Ref: using/windows windows-nuget7056754
Ref: 21e57056754
Ref: The nuget org packages-Footnote-17059136
Ref: The nuget org packages-Footnote-27059167
Ref: The nuget org packages-Footnote-37059213
Ref: The nuget org packages-Footnote-47059262
Node: Free-threaded packages7059313
Ref: using/windows free-threaded-packages7059394
Ref: 22017059394
Ref: Free-threaded packages-Footnote-17059846
Ref: Free-threaded packages-Footnote-27059905
Ref: Free-threaded packages-Footnote-37059967
Node: Alternative bundles7060031
Ref: using/windows alternative-bundles7060176
Ref: 22027060176
Ref: Alternative bundles-Footnote-17061121
Ref: Alternative bundles-Footnote-27061174
Ref: Alternative bundles-Footnote-37061217
Ref: Alternative bundles-Footnote-47061269
Ref: Alternative bundles-Footnote-57061436
Node: Supported Windows versions7061473
Ref: using/windows supported-windows-versions7061628
Ref: 22037061628
Ref: Supported Windows versions-Footnote-17062058
Node: Removing the MAX_PATH limitation7062100
Ref: using/windows max-path7062246
Ref: e3d7062246
Ref: using/windows removing-the-max-path-limitation7062246
Ref: 22047062246
Node: UTF-8 mode7063034
Ref: using/windows utf-8-mode7063169
Ref: 22057063169
Ref: using/windows win-utf8-mode7063169
Ref: 22067063169
Ref: UTF-8 mode-Footnote-17064673
Ref: UTF-8 mode-Footnote-27064715
Node: Finding modules7064757
Ref: using/windows finding-modules7064878
Ref: 22077064878
Ref: using/windows windows-finding-modules7064878
Ref: e1c7064878
Node: Additional modules7069952
Ref: using/windows additional-modules7070090
Ref: 22087070090
Node: PyWin327070491
Ref: using/windows pywin327070571
Ref: 220a7070571
Ref: PyWin32-Footnote-17071157
Ref: PyWin32-Footnote-27071199
Ref: PyWin32-Footnote-37071288
Ref: PyWin32-Footnote-47071357
Ref: PyWin32-Footnote-57071451
Ref: PyWin32-Footnote-67071510
Node: cx_Freeze7071560
Ref: using/windows cx-freeze7071640
Ref: 220b7071640
Ref: cx_Freeze-Footnote-17071914
Node: Compiling Python on Windows7071966
Ref: using/windows compiling-python-on-windows7072118
Ref: 220c7072118
Ref: Compiling Python on Windows-Footnote-17072773
Ref: Compiling Python on Windows-Footnote-27072822
Node: The full installer deprecated7072885
Ref: using/windows the-full-installer-deprecated7073057
Ref: 220e7073057
Ref: using/windows windows-full7073057
Ref: 220f7073057
Node: Installation steps7073593
Ref: using/windows installation-steps7073721
Ref: 22107073721
Node: Removing the MAX_PATH limitation<2>7075835
Ref: using/windows id27075993
Ref: 22127075993
Node: Installing without UI7076858
Ref: using/windows install-quiet-option7077028
Ref: 8057077028
Ref: using/windows installing-without-ui7077028
Ref: 22137077028
Node: Installing without downloading7087524
Ref: using/windows install-layout-option7087679
Ref: 22117087679
Ref: using/windows installing-without-downloading7087679
Ref: 22147087679
Node: Modifying an install7088676
Ref: using/windows modifying-an-install7088846
Ref: 22157088846
Node: Installing free-threaded binaries<2>7089724
Ref: using/windows id37089855
Ref: 22167089855
Ref: Installing free-threaded binaries<2>-Footnote-17091608
Node: Python launcher for Windows deprecated7091650
Ref: using/windows python-launcher-for-windows-deprecated7091786
Ref: 22177091786
Ref: Python launcher for Windows deprecated-Footnote-17092877
Node: Getting started7092919
Ref: using/windows getting-started7093034
Ref: 22187093034
Node: From the command-line7093191
Ref: using/windows from-the-command-line7093293
Ref: 22197093293
Ref: From the command-line-Footnote-17095806
Node: Virtual environments7095848
Ref: using/windows virtual-environments7095972
Ref: 221a7095972
Node: From a script7096472
Ref: using/windows from-a-script7096597
Ref: 221b7096597
Node: From file associations7097643
Ref: using/windows from-file-associations7097739
Ref: 221c7097739
Node: Shebang lines<2>7098318
Ref: using/windows id47098468
Ref: 221d7098468
Node: Arguments in shebang lines7102522
Ref: using/windows arguments-in-shebang-lines7102670
Ref: 221f7102670
Node: Customization7102962
Ref: using/windows customization7103105
Ref: 22207103105
Node: Customization via INI files7103234
Ref: using/windows customization-via-ini-files7103355
Ref: 22217103355
Ref: using/windows launcher-ini7103355
Ref: 221e7103355
Node: Customizing default Python versions7104041
Ref: using/windows customizing-default-python-versions7104162
Ref: 22227104162
Node: Diagnostics7107982
Ref: using/windows diagnostics7108106
Ref: 22237108106
Node: Dry run7108596
Ref: using/windows dry-run7108724
Ref: 22247108724
Node: Install on demand7109158
Ref: using/windows install-on-demand7109287
Ref: 22257109287
Node: Return codes7109870
Ref: using/windows return-codes7109983
Ref: 22267109983
Node: Using Python on macOS7111740
Ref: using/mac doc7111884
Ref: 22277111884
Ref: using/mac translation-repo7111884
Ref: 22287111884
Ref: using/mac using-on-mac7111884
Ref: 22297111884
Ref: using/mac using-python-on-macos7111884
Ref: 222a7111884
Ref: using/mac getting-osx7112593
Ref: 222c7112593
Ref: Using Python on macOS-Footnote-17112854
Node: Using Python for macOS from python org7112896
Ref: using/mac getting-and-installing-macpython7113026
Ref: 222d7113026
Ref: using/mac using-python-for-macos-from-python-org7113026
Ref: 222e7113026
Node: Installation steps<2>7113211
Ref: using/mac installation-steps7113342
Ref: 222f7113342
Ref: Installation steps<2>-Footnote-17118416
Ref: Installation steps<2>-Footnote-27118458
Ref: Installation steps<2>-Footnote-37118506
Ref: Installation steps<2>-Footnote-47118561
Ref: Installation steps<2>-Footnote-57118608
Node: How to run a Python script7118657
Ref: using/mac how-to-run-a-python-script7118788
Ref: 22307118788
Node: Alternative Distributions7120763
Ref: using/mac alternative-bundles7120939
Ref: 222b7120939
Ref: using/mac alternative-distributions7120939
Ref: 22327120939
Ref: Alternative Distributions-Footnote-17122013
Ref: Alternative Distributions-Footnote-27122066
Ref: Alternative Distributions-Footnote-37122109
Ref: Alternative Distributions-Footnote-47122133
Node: Installing Additional Python Packages7122166
Ref: using/mac installing-additional-python-packages7122319
Ref: 22337122319
Ref: using/mac mac-package-manager7122319
Ref: 22347122319
Ref: using/mac osx-gui-scripts7122473
Ref: 22357122473
Ref: Installing Additional Python Packages-Footnote-17122511
Node: GUI Programming7122590
Ref: using/mac gui-programming7122733
Ref: 22367122733
Ref: using/mac gui-programming-on-the-mac7122733
Ref: 22377122733
Ref: GUI Programming-Footnote-17123672
Ref: GUI Programming-Footnote-27123713
Ref: GUI Programming-Footnote-37123753
Ref: GUI Programming-Footnote-47123794
Ref: GUI Programming-Footnote-57123848
Ref: GUI Programming-Footnote-67123873
Ref: GUI Programming-Footnote-77123909
Ref: GUI Programming-Footnote-87123937
Node: Advanced Topics7123966
Ref: using/mac advanced-topics7124087
Ref: 22387124087
Node: Installing Free-threaded Binaries7124280
Ref: using/mac install-freethreaded-macos7124407
Ref: 4997124407
Ref: using/mac installing-free-threaded-binaries7124407
Ref: 22397124407
Ref: Installing Free-threaded Binaries-Footnote-17129511
Node: Installing using the command line7129553
Ref: using/mac installing-using-the-command-line7129721
Ref: 223b7129721
Node: Distributing Python Applications7132523
Ref: using/mac distributing-python-applications7132678
Ref: 223c7132678
Ref: using/mac distributing-python-applications-on-the-mac7132678
Ref: 223d7132678
Ref: Distributing Python Applications-Footnote-17133306
Ref: Distributing Python Applications-Footnote-27133347
Ref: Distributing Python Applications-Footnote-37133388
Ref: Distributing Python Applications-Footnote-47133416
Node: App Store Compliance7133449
Ref: using/mac app-store-compliance7133562
Ref: 223e7133562
Ref: App Store Compliance-Footnote-17134672
Node: Other Resources7134766
Ref: using/mac other-resources7134863
Ref: 223f7134863
Ref: Other Resources-Footnote-17135129
Ref: Other Resources-Footnote-27135172
Node: Using Python on Android7135241
Ref: using/android doc7135381
Ref: 22407135381
Ref: using/android translation-repo7135381
Ref: 22417135381
Ref: using/android using-android7135381
Ref: 22427135381
Ref: using/android using-python-on-android7135381
Ref: 22437135381
Node: Adding Python to an Android app7136614
Ref: using/android adding-python-to-an-android-app7136751
Ref: 22467136751
Ref: Adding Python to an Android app-Footnote-17138358
Ref: Adding Python to an Android app-Footnote-27138399
Ref: Adding Python to an Android app-Footnote-37138440
Ref: Adding Python to an Android app-Footnote-47138476
Ref: Adding Python to an Android app-Footnote-57138543
Ref: Adding Python to an Android app-Footnote-67138574
Ref: Adding Python to an Android app-Footnote-77138642
Ref: Adding Python to an Android app-Footnote-87138692
Ref: Adding Python to an Android app-Footnote-97138762
Ref: Adding Python to an Android app-Footnote-107138852
Ref: Adding Python to an Android app-Footnote-117138975
Node: Building a Python package for Android7139076
Ref: using/android building-a-python-package-for-android7139213
Ref: 22477139213
Ref: Building a Python package for Android-Footnote-17139598
Node: Using Python on iOS7139664
Ref: using/ios doc7139799
Ref: 22487139799
Ref: using/ios translation-repo7139799
Ref: 22497139799
Ref: using/ios using-ios7139799
Ref: 224a7139799
Ref: using/ios using-python-on-ios7139799
Ref: 224b7139799
Ref: Using Python on iOS-Footnote-17141330
Ref: Using Python on iOS-Footnote-27141358
Node: Python at runtime on iOS7141383
Ref: using/ios python-at-runtime-on-ios7141496
Ref: 224c7141496
Node: iOS version compatibility7141717
Ref: using/ios ios-version-compatibility7141835
Ref: 224d7141835
Node: Platform identification7142367
Ref: using/ios platform-identification7142523
Ref: 224e7142523
Node: Standard library availability7143165
Ref: using/ios standard-library-availability7143320
Ref: 22517143320
Node: Binary extension modules7143543
Ref: using/ios binary-extension-modules7143697
Ref: 22527143697
Node: Compiler stub binaries7146555
Ref: using/ios compiler-stub-binaries7146671
Ref: 22567146671
Node: Installing Python on iOS7148063
Ref: using/ios installing-python-on-ios7148208
Ref: 22577148208
Node: Tools for building iOS apps7148378
Ref: using/ios tools-for-building-ios-apps7148506
Ref: 22587148506
Node: Adding Python to an iOS project7149289
Ref: using/ios adding-ios7149450
Ref: 22537149450
Ref: using/ios adding-python-to-an-ios-project7149450
Ref: 22597149450
Ref: Adding Python to an iOS project-Footnote-17154579
Ref: Adding Python to an iOS project-Footnote-27154624
Node: Testing a Python package7154696
Ref: using/ios testing-a-python-package7154821
Ref: 225c7154821
Ref: Testing a Python package-Footnote-17157392
Ref: Testing a Python package-Footnote-27157462
Node: App Store Compliance<2>7157534
Ref: using/ios app-store-compliance7157646
Ref: 225d7157646
Node: Incompatible code in the standard library7158200
Ref: using/ios incompatible-code-in-the-standard-library7158327
Ref: 225e7158327
Ref: Incompatible code in the standard library-Footnote-17158953
Node: Privacy manifests7159047
Ref: using/ios privacy-manifests7159174
Ref: 225f7159174
Ref: Privacy manifests-Footnote-17159913
Node: Editors and IDEs7159986
Ref: using/editors doc7160089
Ref: 22607160089
Ref: using/editors editors7160089
Ref: 22317160089
Ref: using/editors editors-and-ides7160089
Ref: 22617160089
Ref: using/editors translation-repo7160089
Ref: 22627160089
Ref: Editors and IDEs-Footnote-17160401
Node: IDLE — Python editor and shell7160443
Ref: using/editors idle-python-editor-and-shell7160559
Ref: 22637160559
Node: Other Editors and IDEs7160898
Ref: using/editors other-editors-and-ides7161014
Ref: 22647161014
Ref: Other Editors and IDEs-Footnote-17161301
Ref: Other Editors and IDEs-Footnote-27161352
Node: The Python Language Reference7161423
Ref: reference/index doc7161559
Ref: 22657161559
Ref: reference/index reference-index7161559
Ref: 14a7161559
Ref: reference/index the-python-language-reference7161559
Ref: 22667161559
Ref: reference/index translation-repo7161559
Ref: 22677161559
Node: Introduction<4>7162547
Ref: reference/introduction doc7162653
Ref: 22687162653
Ref: reference/introduction id17162653
Ref: 22697162653
Ref: reference/introduction introduction7162653
Ref: 226a7162653
Node: Alternate Implementations7164446
Ref: reference/introduction alternate-implementations7164540
Ref: 226b7164540
Ref: reference/introduction implementations7164540
Ref: 21017164540
Ref: Alternate Implementations-Footnote-17166720
Ref: Alternate Implementations-Footnote-27166752
Ref: Alternate Implementations-Footnote-37166789
Ref: Alternate Implementations-Footnote-47166821
Node: Notation7166847
Ref: reference/introduction id27166941
Ref: 226c7166941
Ref: reference/introduction notation7166941
Ref: 226d7166941
Ref: reference/introduction grammar-token-notation-name7167098
Ref: 226e7167098
Ref: reference/introduction grammar-token-notation-letter7167181
Ref: 226f7167181
Ref: reference/introduction grammar-token-notation-digit7167216
Ref: 22707167216
Ref: reference/introduction lexical-lookaheads7169962
Ref: 22777169962
Ref: reference/introduction grammar-token-notation-literal7170547
Ref: 22787170547
Ref: reference/introduction grammar-token-notation-alt-literal7170801
Ref: 22797170801
Ref: Notation-Footnote-17171072
Ref: Notation-Footnote-27171144
Ref: Notation-Footnote-37171209
Node: Lexical and Syntactic definitions7171251
Ref: reference/introduction lexical-and-syntactic-definitions7171329
Ref: 227a7171329
Ref: reference/introduction notation-lexical-vs-syntactic7171329
Ref: 22767171329
Node: Lexical analysis7172358
Ref: reference/lexical_analysis doc7172483
Ref: 227f7172483
Ref: reference/lexical_analysis lexical7172483
Ref: 227e7172483
Ref: reference/lexical_analysis lexical-analysis7172483
Ref: 22807172483
Ref: reference/lexical_analysis translation-repo7172483
Ref: 22817172483
Node: Line structure7177236
Ref: reference/lexical_analysis id17177324
Ref: 228c7177324
Ref: reference/lexical_analysis line-structure7177324
Ref: 22847177324
Node: Logical lines7177645
Ref: reference/lexical_analysis id27177732
Ref: 228d7177732
Ref: reference/lexical_analysis logical-lines7177732
Ref: 228e7177732
Node: Physical lines7178156
Ref: reference/lexical_analysis id37178260
Ref: 22907178260
Ref: reference/lexical_analysis physical-lines7178260
Ref: 22917178260
Ref: reference/lexical_analysis grammar-token-python-grammar-newline7178969
Ref: 22927178969
Ref: Physical lines-Footnote-17179068
Node: Comments7179121
Ref: reference/lexical_analysis comments7179233
Ref: 22877179233
Ref: reference/lexical_analysis id57179233
Ref: 22937179233
Node: Encoding declarations7179536
Ref: reference/lexical_analysis encoding-declarations7179655
Ref: 22947179655
Ref: reference/lexical_analysis encodings7179655
Ref: 22827179655
Ref: reference/lexical_analysis lexical-source-character7180777
Ref: 22837180777
Ref: reference/lexical_analysis grammar-token-python-grammar-source_character7181000
Ref: 22957181000
Node: Explicit line joining7181062
Ref: reference/lexical_analysis explicit-joining7181194
Ref: 22867181194
Ref: reference/lexical_analysis explicit-line-joining7181194
Ref: 22967181194
Node: Implicit line joining7182128
Ref: reference/lexical_analysis implicit-joining7182250
Ref: 228f7182250
Ref: reference/lexical_analysis implicit-line-joining7182250
Ref: 22977182250
Node: Blank lines7183086
Ref: reference/lexical_analysis blank-lines7183198
Ref: 22987183198
Ref: reference/lexical_analysis id67183198
Ref: 22997183198
Node: Indentation7183689
Ref: reference/lexical_analysis id77183805
Ref: 229a7183805
Ref: reference/lexical_analysis indentation7183805
Ref: 22857183805
Node: Whitespace between tokens7187235
Ref: reference/lexical_analysis whitespace7187350
Ref: 227c7187350
Ref: reference/lexical_analysis whitespace-between-tokens7187350
Ref: 229c7187350
Ref: reference/lexical_analysis grammar-token-python-grammar-whitespace7187583
Ref: 229d7187583
Node: End marker7187924
Ref: reference/lexical_analysis end-marker7188019
Ref: 229e7188019
Ref: reference/lexical_analysis endmarker-token7188019
Ref: 228b7188019
Node: Other tokens7188162
Ref: reference/lexical_analysis id87188289
Ref: 22a07188289
Ref: reference/lexical_analysis other-tokens7188289
Ref: 22a17188289
Node: Names identifiers and keywords7188879
Ref: reference/lexical_analysis identifiers7189000
Ref: 22897189000
Ref: reference/lexical_analysis names-identifiers-and-keywords7189000
Ref: 22a57189000
Ref: reference/lexical_analysis grammar-token-python-grammar-NAME7189744
Ref: 22a77189744
Ref: reference/lexical_analysis grammar-token-python-grammar-name_start7189816
Ref: 22a87189816
Ref: reference/lexical_analysis grammar-token-python-grammar-name_continue7189888
Ref: 22a97189888
Ref: reference/lexical_analysis grammar-token-python-grammar-identifier7189931
Ref: 22aa7189931
Node: Keywords7190219
Ref: reference/lexical_analysis id97190316
Ref: 22ab7190316
Ref: reference/lexical_analysis keywords7190316
Ref: 22727190316
Node: Soft Keywords7190905
Ref: reference/lexical_analysis id107191042
Ref: 22ac7191042
Ref: reference/lexical_analysis soft-keywords7191042
Ref: a0f7191042
Node: Reserved classes of identifiers7191717
Ref: reference/lexical_analysis id-classes7191875
Ref: 22ad7191875
Ref: reference/lexical_analysis reserved-classes-of-identifiers7191875
Ref: 22ae7191875
Node: Non-ASCII characters in names7193792
Ref: reference/lexical_analysis lexical-names-nonascii7193928
Ref: 22a67193928
Ref: reference/lexical_analysis non-ascii-characters-in-names7193928
Ref: 22b07193928
Ref: Non-ASCII characters in names-Footnote-17197501
Ref: Non-ASCII characters in names-Footnote-27197558
Ref: Non-ASCII characters in names-Footnote-37197604
Ref: Non-ASCII characters in names-Footnote-47197650
Ref: Non-ASCII characters in names-Footnote-57197727
Ref: Non-ASCII characters in names-Footnote-67197790
Ref: Non-ASCII characters in names-Footnote-77197853
Ref: Non-ASCII characters in names-Footnote-87197895
Node: Literals7197937
Ref: reference/lexical_analysis id117198071
Ref: 22b17198071
Ref: reference/lexical_analysis literals7198071
Ref: 22b27198071
Node: String and Bytes literals7198439
Ref: reference/lexical_analysis string-and-bytes-literals7198559
Ref: 22b47198559
Ref: reference/lexical_analysis strings7198559
Ref: 22887198559
Node: Triple-quoted strings7199720
Ref: reference/lexical_analysis triple-quoted-strings7199827
Ref: 22b57199827
Node: String prefixes7200456
Ref: reference/lexical_analysis string-prefixes7200586
Ref: 22b67200586
Ref: String prefixes-Footnote-17201779
Node: Formal grammar7201821
Ref: reference/lexical_analysis formal-grammar7201946
Ref: 22b97201946
Ref: reference/lexical_analysis grammar-token-python-grammar-STRING7202244
Ref: 22ba7202244
Ref: reference/lexical_analysis grammar-token-python-grammar-stringprefix7202323
Ref: 22bb7202323
Ref: reference/lexical_analysis grammar-token-python-grammar-stringcontent7202397
Ref: 22bc7202397
Ref: reference/lexical_analysis grammar-token-python-grammar-stringitem7202641
Ref: 22be7202641
Ref: reference/lexical_analysis grammar-token-python-grammar-stringchar7202718
Ref: 22bf7202718
Ref: reference/lexical_analysis grammar-token-python-grammar-longstringitem7202805
Ref: 22bd7202805
Ref: reference/lexical_analysis grammar-token-python-grammar-stringescapeseq7202861
Ref: 22c07202861
Node: Escape sequences7203081
Ref: reference/lexical_analysis escape-sequences7203205
Ref: 6887203205
Ref: reference/lexical_analysis id127203205
Ref: 22c17203205
Node: Ignored end of line7207090
Ref: reference/lexical_analysis ignored-end-of-line7207189
Ref: 22c87207189
Ref: reference/lexical_analysis string-escape-ignore7207189
Ref: 22c27207189
Node: Escaped characters7207609
Ref: reference/lexical_analysis escaped-characters7207732
Ref: 22ca7207732
Ref: reference/lexical_analysis string-escape-escaped-char7207732
Ref: 22c37207732
Node: Octal character7208157
Ref: reference/lexical_analysis octal-character7208282
Ref: 22cb7208282
Ref: reference/lexical_analysis string-escape-oct7208282
Ref: 22c47208282
Node: Hexadecimal character7208957
Ref: reference/lexical_analysis hexadecimal-character7209087
Ref: 22cc7209087
Ref: reference/lexical_analysis string-escape-hex7209087
Ref: 22c57209087
Node: Named Unicode character7209459
Ref: reference/lexical_analysis named-unicode-character7209604
Ref: 22cd7209604
Ref: reference/lexical_analysis string-escape-named7209604
Ref: 22c67209604
Ref: Named Unicode character-Footnote-17210000
Node: Hexadecimal Unicode characters7210066
Ref: reference/lexical_analysis hexadecimal-unicode-characters7210219
Ref: 22ce7210219
Ref: reference/lexical_analysis string-escape-long-hex7210219
Ref: 22c77210219
Node: Unrecognized escape sequences7210684
Ref: reference/lexical_analysis unrecognized-escape-sequences7210805
Ref: 22cf7210805
Node: Bytes literals7211533
Ref: reference/lexical_analysis bytes-literal7211662
Ref: 22b77211662
Ref: reference/lexical_analysis bytes-literals7211662
Ref: 22d07211662
Node: Raw string literals7212319
Ref: reference/lexical_analysis raw-string-literals7212441
Ref: 22d17212441
Ref: reference/lexical_analysis raw-strings7212441
Ref: 22b87212441
Ref: reference/lexical_analysis f-strings7213493
Ref: 19a7213493
Node: f-strings7213493
Ref: reference/lexical_analysis formatted-string-literals7213610
Ref: 22d27213610
Ref: reference/lexical_analysis id137213610
Ref: 22d37213610
Ref: reference/lexical_analysis t-strings7218685
Ref: 17e27218685
Ref: f-strings-Footnote-17218721
Ref: f-strings-Footnote-27218763
Node: t-strings7218805
Ref: reference/lexical_analysis id147218931
Ref: 22d67218931
Ref: reference/lexical_analysis template-string-literals7218931
Ref: 22d77218931
Node: Formal grammar for f-strings7219293
Ref: reference/lexical_analysis formal-grammar-for-f-strings7219401
Ref: 22d97219401
Ref: reference/lexical_analysis grammar-token-python-grammar-fstring7220828
Ref: 22dd7220828
Ref: reference/lexical_analysis grammar-token-python-grammar-FSTRING_START7220927
Ref: 22de7220927
Ref: reference/lexical_analysis grammar-token-python-grammar-FSTRING_END7221007
Ref: 22e07221007
Ref: reference/lexical_analysis grammar-token-python-grammar-fstringprefix7221053
Ref: 22e17221053
Ref: reference/lexical_analysis grammar-token-python-grammar-f_debug_specifier7221118
Ref: 22e37221118
Ref: reference/lexical_analysis grammar-token-python-grammar-f_quote7221147
Ref: 22e27221147
Ref: reference/lexical_analysis grammar-token-python-grammar-fstring_middle7221220
Ref: 22df7221220
Ref: reference/lexical_analysis grammar-token-python-grammar-FSTRING_MIDDLE7221328
Ref: 22e57221328
Ref: reference/lexical_analysis grammar-token-python-grammar-fstring_replacement_field7221572
Ref: 22e47221572
Ref: reference/lexical_analysis grammar-token-python-grammar-fstring_conversion7221769
Ref: 22e77221769
Ref: reference/lexical_analysis grammar-token-python-grammar-fstring_full_format_spec7221826
Ref: 22e87221826
Ref: reference/lexical_analysis grammar-token-python-grammar-fstring_format_spec7221905
Ref: 22e97221905
Ref: reference/lexical_analysis grammar-token-python-grammar-f_expression7222018
Ref: 22e67222018
Ref: reference/lexical_analysis grammar-token-python-grammar-tstring7222648
Ref: 22ed7222648
Node: Numeric literals7222767
Ref: reference/lexical_analysis numbers7222903
Ref: 228a7222903
Ref: reference/lexical_analysis numeric-literals7222903
Ref: 22ee7222903
Ref: reference/lexical_analysis grammar-token-python-grammar-NUMBER7223095
Ref: 22ef7223095
Node: Integer literals7223687
Ref: reference/lexical_analysis integer-literals7223788
Ref: 22f37223788
Ref: reference/lexical_analysis integers7223788
Ref: 22f47223788
Ref: reference/lexical_analysis grammar-token-python-grammar-integer7225244
Ref: 22f07225244
Ref: reference/lexical_analysis grammar-token-python-grammar-decinteger7225392
Ref: 22f57225392
Ref: reference/lexical_analysis grammar-token-python-grammar-bininteger7225465
Ref: 22f67225465
Ref: reference/lexical_analysis grammar-token-python-grammar-octinteger7225531
Ref: 22f77225531
Ref: reference/lexical_analysis grammar-token-python-grammar-hexinteger7225597
Ref: 22f87225597
Ref: reference/lexical_analysis grammar-token-python-grammar-zerointeger7225663
Ref: 22f97225663
Ref: reference/lexical_analysis grammar-token-python-grammar-nonzerodigit7225700
Ref: 22fa7225700
Ref: reference/lexical_analysis grammar-token-python-grammar-digit7225729
Ref: 22fb7225729
Ref: reference/lexical_analysis grammar-token-python-grammar-bindigit7225758
Ref: 22fc7225758
Ref: reference/lexical_analysis grammar-token-python-grammar-octdigit7225787
Ref: 22fd7225787
Ref: reference/lexical_analysis grammar-token-python-grammar-hexdigit7225816
Ref: 22fe7225816
Node: Floating-point literals7225972
Ref: reference/lexical_analysis floating7226100
Ref: 22ff7226100
Ref: reference/lexical_analysis floating-point-literals7226100
Ref: 23007226100
Ref: reference/lexical_analysis grammar-token-python-grammar-floatnumber7227575
Ref: 22f17227575
Ref: reference/lexical_analysis grammar-token-python-grammar-digitpart7227795
Ref: 23027227795
Ref: reference/lexical_analysis grammar-token-python-grammar-exponent7227858
Ref: 23037227858
Node: Imaginary literals7228015
Ref: reference/lexical_analysis imaginary7228118
Ref: 23047228118
Ref: reference/lexical_analysis imaginary-literals7228118
Ref: 23057228118
Ref: reference/lexical_analysis grammar-token-python-grammar-imagnumber7229630
Ref: 22f27229630
Ref: reference/lexical_analysis delimiters7229711
Ref: 22747229711
Ref: reference/lexical_analysis operators7229711
Ref: 22757229711
Node: Operators and delimiters7229712
Ref: reference/lexical_analysis lexical-ellipsis7229814
Ref: 22b37229814
Ref: reference/lexical_analysis operators-and-delimiters7229814
Ref: 23067229814
Ref: reference/lexical_analysis grammar-token-python-grammar-OP7230104
Ref: 23087230104
Ref: reference/lexical_analysis grammar-token-python-grammar-assignment_operator7230322
Ref: 23097230322
Ref: reference/lexical_analysis grammar-token-python-grammar-bitwise_operator7230480
Ref: 230a7230480
Ref: reference/lexical_analysis grammar-token-python-grammar-comparison_operator7230550
Ref: 230b7230550
Ref: reference/lexical_analysis grammar-token-python-grammar-enclosing_delimiter7230620
Ref: 230c7230620
Ref: reference/lexical_analysis grammar-token-python-grammar-other_delimiter7230689
Ref: 230d7230689
Ref: reference/lexical_analysis grammar-token-python-grammar-arithmetic_operator7230759
Ref: 230e7230759
Ref: reference/lexical_analysis grammar-token-python-grammar-other_op7230836
Ref: 230f7230836
Node: Data model7231887
Ref: reference/datamodel doc7232012
Ref: 23127232012
Ref: reference/datamodel data-model7232012
Ref: 23137232012
Ref: reference/datamodel datamodel7232012
Ref: 1d427232012
Ref: reference/datamodel translation-repo7232012
Ref: 23147232012
Node: Objects values and types7232180
Ref: reference/datamodel objects7232287
Ref: 23157232287
Ref: reference/datamodel objects-values-and-types7232287
Ref: 23167232287
Ref: Objects values and types-Footnote-17237247
Node: The standard type hierarchy7237474
Ref: reference/datamodel the-standard-type-hierarchy7237610
Ref: 23177237610
Ref: reference/datamodel types7237610
Ref: 23187237610
Node: None7238620
Ref: reference/datamodel none7238711
Ref: 23197238711
Node: NotImplemented7239044
Ref: reference/datamodel notimplemented7239152
Ref: 231a7239152
Node: Ellipsis7240057
Ref: reference/datamodel ellipsis7240175
Ref: 231c7240175
Node: numbers Number7240401
Ref: reference/datamodel numbers-number7240514
Ref: 231d7240514
Node: numbers Integral7241745
Ref: reference/datamodel numbers-integral7241839
Ref: 231e7241839
Node: numbers Real float7243062
Ref: reference/datamodel datamodel-float7243188
Ref: 23017243188
Ref: reference/datamodel numbers-real-float7243188
Ref: 231f7243188
Node: numbers Complex complex7243773
Ref: reference/datamodel numbers-complex-complex7243874
Ref: 23207243874
Node: Sequences7244254
Ref: reference/datamodel sequences7244368
Ref: 23217244368
Node: Immutable sequences7245523
Ref: reference/datamodel immutable-sequences7245614
Ref: 23227245614
Node: Mutable sequences7247585
Ref: reference/datamodel mutable-sequences7247676
Ref: 23247247676
Node: Set types7248652
Ref: reference/datamodel set-types7248760
Ref: 23257248760
Node: Mappings7249993
Ref: reference/datamodel mappings7250106
Ref: 23277250106
Node: Dictionaries7250572
Ref: reference/datamodel dictionaries7250629
Ref: 23287250629
Node: Callable types7252073
Ref: reference/datamodel callable-types7252187
Ref: 23297252187
Node: User-defined functions7252561
Ref: reference/datamodel user-defined-funcs7252659
Ref: 59c7252659
Ref: reference/datamodel user-defined-functions7252659
Ref: 232a7252659
Node: Special read-only attributes7253038
Ref: reference/datamodel special-read-only-attributes7253161
Ref: 232b7253161
Ref: reference/datamodel function __builtins__7253560
Ref: 232c7253560
Ref: reference/datamodel function __globals__7254005
Ref: 14db7254005
Ref: reference/datamodel function __closure__7254511
Ref: 14d87254511
Node: Special writable attributes7255275
Ref: reference/datamodel special-writable-attributes7255398
Ref: 232f7255398
Ref: reference/datamodel function __doc__7255854
Ref: 13e17255854
Ref: reference/datamodel function __name__7256146
Ref: 14dc7256146
Ref: reference/datamodel function __qualname__7256439
Ref: 23307256439
Ref: reference/datamodel function __module__7256885
Ref: 23317256885
Ref: reference/datamodel function __defaults__7257191
Ref: 14d97257191
Ref: reference/datamodel function __code__7257682
Ref: 59d7257682
Ref: reference/datamodel function __dict__7257973
Ref: 14da7257973
Ref: reference/datamodel function __annotations__7258356
Ref: 13e07258356
Ref: reference/datamodel function __annotate__7259235
Ref: 23337259235
Ref: reference/datamodel function __kwdefaults__7259789
Ref: 122a7259789
Ref: reference/datamodel function __type_params__7260098
Ref: 23347260098
Ref: Special writable attributes-Footnote-17261148
Node: Instance methods7261190
Ref: reference/datamodel id27261316
Ref: 23367261316
Ref: reference/datamodel instance-methods7261316
Ref: 20917261316
Ref: reference/datamodel method __self__7261552
Ref: 15d07261552
Ref: reference/datamodel method __func__7261852
Ref: 15047261852
Ref: reference/datamodel method __doc__7262069
Ref: 23387262069
Ref: reference/datamodel method __name__7262560
Ref: 23397262560
Ref: reference/datamodel method __module__7262855
Ref: 233a7262855
Ref: reference/datamodel method-binding7263421
Ref: 23377263421
Node: Generator functions7264893
Ref: reference/datamodel generator-functions7265016
Ref: 233b7265016
Node: Coroutine functions7265720
Ref: reference/datamodel coroutine-functions7265859
Ref: 233c7265859
Node: Asynchronous generator functions7266263
Ref: reference/datamodel asynchronous-generator-functions7266401
Ref: 233e7266401
Node: Built-in functions7267271
Ref: reference/datamodel built-in-functions7267406
Ref: 233f7267406
Ref: reference/datamodel builtin-functions7267406
Ref: 23357267406
Node: Built-in methods7268196
Ref: reference/datamodel built-in-methods7268306
Ref: 23407268306
Ref: reference/datamodel builtin-methods7268306
Ref: 23417268306
Node: Classes7268795
Ref: reference/datamodel classes7268902
Ref: 23427268902
Ref: reference/datamodel id37268902
Ref: 23437268902
Node: Class Instances7269255
Ref: reference/datamodel class-instances7269337
Ref: 23447269337
Node: Modules<2>7269501
Ref: reference/datamodel module-objects7269621
Ref: 23457269621
Ref: reference/datamodel modules7269621
Ref: 23467269621
Node: Import-related attributes on module objects7270644
Ref: reference/datamodel import-mod-attrs7270786
Ref: 23487270786
Ref: reference/datamodel import-related-attributes-on-module-objects7270786
Ref: 23497270786
Ref: reference/datamodel module __name__7272438
Ref: 15937272438
Ref: reference/datamodel module __spec__7272777
Ref: 234b7272777
Ref: reference/datamodel module __package__7273036
Ref: 3237273036
Ref: reference/datamodel module __loader__7275134
Ref: 33b7275134
Ref: reference/datamodel module __path__7276360
Ref: 203e7276360
Ref: reference/datamodel module __file__7276817
Ref: 23507276817
Ref: reference/datamodel module __cached__7276849
Ref: 3217276849
Ref: Import-related attributes on module objects-Footnote-17278832
Ref: Import-related attributes on module objects-Footnote-27278874
Node: Other writable attributes on module objects7278916
Ref: reference/datamodel other-writable-attributes-on-module-objects7279086
Ref: 23527279086
Ref: reference/datamodel module __doc__7279309
Ref: 1bd77279309
Ref: reference/datamodel module __annotations__7279460
Ref: 23537279460
Ref: reference/datamodel module __annotate__7279806
Ref: 23547279806
Ref: Other writable attributes on module objects-Footnote-17280071
Node: Module dictionaries7280113
Ref: reference/datamodel module-dictionaries7280231
Ref: 23557280231
Ref: reference/datamodel module __dict__7280359
Ref: 23567280359
Node: Custom classes7280991
Ref: reference/datamodel class-attrs-and-methods7281112
Ref: 23577281112
Ref: reference/datamodel custom-classes7281112
Ref: 23587281112
Node: Special attributes7282729
Ref: reference/datamodel special-attributes7282822
Ref: 23597282822
Ref: reference/datamodel type __name__7283193
Ref: 16b27283193
Ref: reference/datamodel type __qualname__7283483
Ref: 235a7283483
Ref: reference/datamodel type __module__7283793
Ref: 6177283793
Ref: reference/datamodel type __dict__7284068
Ref: e597284068
Ref: reference/datamodel type __bases__7284472
Ref: 16b37284472
Ref: reference/datamodel type __base__7284977
Ref: 235b7284977
Ref: reference/datamodel type __doc__7285580
Ref: 207f7285580
Ref: reference/datamodel type __annotations__7285904
Ref: 182b7285904
Ref: reference/datamodel type __annotate__7288371
Ref: 184f7288371
Ref: reference/datamodel type __type_params__7288930
Ref: 235d7288930
Ref: reference/datamodel type __static_attributes__7289441
Ref: 4777289441
Ref: reference/datamodel type __firstlineno__7289982
Ref: 4787289982
Ref: reference/datamodel type __mro__7290636
Ref: 235e7290636
Ref: Special attributes-Footnote-17290976
Ref: Special attributes-Footnote-27291037
Node: Special methods7291079
Ref: reference/datamodel special-methods7291172
Ref: 235f7291172
Ref: reference/datamodel type mro7291345
Ref: 23607291345
Ref: reference/datamodel type __subclasses__7291578
Ref: 7947291578
Node: Class instances7291928
Ref: reference/datamodel id47292077
Ref: 23617292077
Node: Special attributes<2>7293555
Ref: reference/datamodel id57293628
Ref: 23647293628
Ref: reference/datamodel object __class__7293685
Ref: 16b47293685
Ref: reference/datamodel object __dict__7293769
Ref: 77e7293769
Node: I/O objects also known as file objects7294022
Ref: reference/datamodel i-o-objects-also-known-as-file-objects7294171
Ref: 23667294171
Node: Internal types7294915
Ref: reference/datamodel internal-types7295040
Ref: 23687295040
Node: Code objects7295414
Ref: reference/datamodel code-objects7295499
Ref: 4e77295499
Ref: reference/datamodel id67295499
Ref: 23697295499
Node: Special read-only attributes<2>7296232
Ref: reference/datamodel id77296344
Ref: 236a7296344
Ref: reference/datamodel codeobject co_name7296454
Ref: 236b7296454
Ref: reference/datamodel codeobject co_qualname7296643
Ref: 236c7296643
Ref: reference/datamodel codeobject co_argcount7296978
Ref: 236d7296978
Ref: reference/datamodel codeobject co_posonlyargcount7297468
Ref: 236e7297468
Ref: reference/datamodel codeobject co_kwonlyargcount7297862
Ref: 236f7297862
Ref: reference/datamodel codeobject co_nlocals7298247
Ref: 23707298247
Ref: reference/datamodel codeobject co_varnames7298557
Ref: 23717298557
Ref: reference/datamodel codeobject co_cellvars7298950
Ref: 23727298950
Ref: reference/datamodel codeobject co_freevars7299439
Ref: 232e7299439
Ref: reference/datamodel codeobject co_code7300187
Ref: 23747300187
Ref: reference/datamodel codeobject co_consts7300499
Ref: 18837300499
Ref: reference/datamodel codeobject co_names7300813
Ref: 23757300813
Ref: reference/datamodel codeobject co_filename7301128
Ref: 15757301128
Ref: reference/datamodel codeobject co_firstlineno7301407
Ref: 23767301407
Ref: reference/datamodel codeobject co_lnotab7301619
Ref: 3307301619
Ref: reference/datamodel codeobject co_stacksize7302367
Ref: 23777302367
Ref: reference/datamodel codeobject co_flags7302573
Ref: 18c37302573
Node: Methods on code objects7303751
Ref: reference/datamodel methods-on-code-objects7303863
Ref: 237b7303863
Ref: reference/datamodel codeobject co_positions7303930
Ref: 7d17303930
Ref: reference/datamodel codeobject co_lines7305479
Ref: 3507305479
Ref: reference/datamodel codeobject replace7307114
Ref: 237c7307114
Ref: Methods on code objects-Footnote-17307401
Node: Frame objects7307443
Ref: reference/datamodel frame-objects7307554
Ref: 8f07307554
Ref: reference/datamodel id87307554
Ref: 237d7307554
Node: Special read-only attributes<3>7307907
Ref: reference/datamodel id97308027
Ref: 237e7308027
Ref: reference/datamodel frame f_back7308131
Ref: 9907308131
Ref: reference/datamodel frame f_code7308458
Ref: 237f7308458
Ref: reference/datamodel frame f_locals7308984
Ref: 4a67308984
Ref: reference/datamodel frame f_globals7309721
Ref: 23807309721
Ref: reference/datamodel frame f_builtins7310018
Ref: 23817310018
Ref: reference/datamodel frame f_lasti7310321
Ref: a8a7310321
Ref: reference/datamodel frame f_generator7310737
Ref: 23827310737
Node: Special writable attributes<2>7311191
Ref: reference/datamodel id107311340
Ref: 23837311340
Ref: reference/datamodel frame f_trace7311443
Ref: 23847311443
Ref: reference/datamodel frame f_trace_lines7311986
Ref: dd87311986
Ref: reference/datamodel frame f_trace_opcodes7312310
Ref: dd97312310
Ref: reference/datamodel frame f_lineno7312913
Ref: 9b17312913
Node: Frame object methods7313456
Ref: reference/datamodel frame-object-methods7313565
Ref: 23857313565
Ref: reference/datamodel frame clear7313661
Ref: 5857313661
Node: Traceback objects7314348
Ref: reference/datamodel id117314460
Ref: 23867314460
Ref: reference/datamodel traceback-objects7314460
Ref: cee7314460
Ref: reference/datamodel traceback tb_frame7315792
Ref: 23877315792
Ref: reference/datamodel traceback tb_lineno7316435
Ref: 23887316435
Ref: reference/datamodel traceback tb_lasti7316652
Ref: 23897316652
Ref: reference/datamodel traceback tb_next7317015
Ref: ced7317015
Node: Slice objects7317304
Ref: reference/datamodel slice-objects7317424
Ref: 238a7317424
Ref: reference/datamodel slice indices7317871
Ref: 12297317871
Node: Static method objects7318353
Ref: reference/datamodel static-method-objects7318476
Ref: 238e7318476
Node: Class method objects7319076
Ref: reference/datamodel class-method-objects7319177
Ref: 238f7319177
Node: Special method names7319622
Ref: reference/datamodel special-method-names7319744
Ref: 23907319744
Ref: reference/datamodel specialnames7319744
Ref: e6a7319744
Ref: Special method names-Footnote-17321689
Node: Basic customization7322026
Ref: reference/datamodel basic-customization7322139
Ref: 23927322139
Ref: reference/datamodel customization7322139
Ref: 23937322139
Ref: reference/datamodel object __new__7322196
Ref: 7a17322196
Ref: reference/datamodel object __init__7323753
Ref: 8c07323753
Ref: reference/datamodel object __del__7324612
Ref: 11ff7324612
Ref: reference/datamodel object __repr__7327929
Ref: 8307327929
Ref: reference/datamodel object __str__7328854
Ref: 8317328854
Ref: reference/datamodel object __bytes__7329529
Ref: 7ff7329529
Ref: reference/datamodel object __format__7329785
Ref: 8327329785
Ref: reference/datamodel richcmpfuncs7331065
Ref: 23947331065
Ref: reference/datamodel object __lt__7331065
Ref: 14a87331065
Ref: reference/datamodel object __le__7331105
Ref: 15127331105
Ref: reference/datamodel object __eq__7331145
Ref: cf47331145
Ref: reference/datamodel object __ne__7331185
Ref: 171e7331185
Ref: reference/datamodel object __gt__7331225
Ref: 15137331225
Ref: reference/datamodel object __ge__7331265
Ref: 15147331265
Ref: reference/datamodel object __hash__7334347
Ref: cf57334347
Ref: reference/datamodel object __bool__7338633
Ref: 14dd7338633
Node: Customizing attribute access7339133
Ref: reference/datamodel attribute-access7339281
Ref: 23957339281
Ref: reference/datamodel customizing-attribute-access7339281
Ref: 23967339281
Ref: reference/datamodel object __getattr__7339513
Ref: 6fb7339513
Ref: reference/datamodel object __getattribute__7340832
Ref: dcd7340832
Ref: reference/datamodel object __setattr__7341938
Ref: 23627341938
Ref: reference/datamodel object __delattr__7342613
Ref: 23637342613
Ref: reference/datamodel object __dir__7342999
Ref: 17ca7342999
Node: Customizing module attribute access7343341
Ref: reference/datamodel customizing-module-attribute-access7343474
Ref: 23987343474
Ref: reference/datamodel module __getattr__7343563
Ref: cda7343563
Ref: reference/datamodel module __dir__7343597
Ref: cdb7343597
Ref: reference/datamodel module __class__7344451
Ref: 23997344451
Ref: Customizing module attribute access-Footnote-17345711
Node: Implementing Descriptors7345753
Ref: reference/datamodel descriptors7345915
Ref: e4b7345915
Ref: reference/datamodel implementing-descriptors7345915
Ref: 239a7345915
Ref: reference/datamodel object __get__7346473
Ref: 16ef7346473
Ref: reference/datamodel object __set__7347404
Ref: 239b7347404
Ref: reference/datamodel object __delete__7347760
Ref: 19377347760
Ref: reference/datamodel object __objclass__7347978
Ref: 239d7347978
Ref: Implementing Descriptors-Footnote-17348545
Node: Invoking Descriptors7348587
Ref: reference/datamodel descriptor-invocation7348726
Ref: 239c7348726
Ref: reference/datamodel invoking-descriptors7348726
Ref: 239e7348726
Node: __slots__<2>7351878
Ref: reference/datamodel id137351984
Ref: 239f7351984
Ref: reference/datamodel slots7351984
Ref: 23657351984
Ref: reference/datamodel object __slots__7352361
Ref: 16f27352361
Ref: reference/datamodel datamodel-note-slots7352684
Ref: 23a07352684
Node: Customizing class creation7355771
Ref: reference/datamodel class-customization7355940
Ref: e477355940
Ref: reference/datamodel customizing-class-creation7355940
Ref: 23a27355940
Ref: reference/datamodel object __init_subclass__7356425
Ref: 8447356425
Ref: reference/datamodel object __set_name__7357895
Ref: e4a7357895
Node: Metaclasses7358860
Ref: reference/datamodel id147358964
Ref: 23a37358964
Ref: reference/datamodel metaclasses7358964
Ref: 23a47358964
Node: Resolving MRO entries7360019
Ref: reference/datamodel resolving-mro-entries7360169
Ref: 23a57360169
Ref: reference/datamodel object __mro_entries__7360230
Ref: ce57360230
Ref: Resolving MRO entries-Footnote-17361247
Node: Determining the appropriate metaclass7361289
Ref: reference/datamodel determining-the-appropriate-metaclass7361457
Ref: 23a67361457
Node: Preparing the class namespace7362388
Ref: reference/datamodel prepare7362559
Ref: e5a7362559
Ref: reference/datamodel preparing-the-class-namespace7362559
Ref: 23a77362559
Ref: Preparing the class namespace-Footnote-17363466
Node: Executing the class body7363508
Ref: reference/datamodel executing-the-class-body7363667
Ref: 23a87363667
Node: Creating the class object7364402
Ref: reference/datamodel class-object-creation7364552
Ref: e467364552
Ref: reference/datamodel creating-the-class-object7364552
Ref: 23a97364552
Ref: Creating the class object-Footnote-17367015
Node: Uses for metaclasses7367057
Ref: reference/datamodel uses-for-metaclasses7367174
Ref: 23aa7367174
Node: Customizing instance and subclass checks7367485
Ref: reference/datamodel customizing-instance-and-subclass-checks7367649
Ref: 23ab7367649
Ref: reference/datamodel type __instancecheck__7368138
Ref: 23ac7368138
Ref: reference/datamodel type __subclasscheck__7368366
Ref: 23ad7368366
Ref: Customizing instance and subclass checks-Footnote-17369322
Node: Emulating generic types7369364
Ref: reference/datamodel emulating-generic-types7369528
Ref: 23ae7369528
Ref: reference/datamodel object __class_getitem__7370447
Ref: 9447370447
Ref: Emulating generic types-Footnote-17370945
Node: The purpose of __class_getitem__7370987
Ref: reference/datamodel the-purpose-of-class-getitem7371124
Ref: 23b07371124
Node: __class_getitem__ versus __getitem__7372015
Ref: reference/datamodel class-getitem-versus-getitem7372152
Ref: 23b27372152
Ref: reference/datamodel classgetitem-versus-getitem7372152
Ref: 23b37372152
Ref: __class_getitem__ versus __getitem__-Footnote-17375487
Node: Emulating callable objects7375529
Ref: reference/datamodel emulating-callable-objects7375678
Ref: 23b77375678
Ref: reference/datamodel id157375678
Ref: 23b87375678
Ref: reference/datamodel object __call__7375751
Ref: 77b7375751
Node: Emulating container types7376052
Ref: reference/datamodel emulating-container-types7376201
Ref: 23b97376201
Ref: reference/datamodel sequence-types7376201
Ref: 23ba7376201
Ref: reference/datamodel object __len__7378642
Ref: 17777378642
Ref: reference/datamodel object __length_hint__7379391
Ref: 11107379391
Ref: reference/datamodel object __getitem__7380181
Ref: 5887380181
Ref: reference/datamodel object __setitem__7381305
Ref: 14d37381305
Ref: reference/datamodel object __delitem__7381767
Ref: 14d47381767
Ref: reference/datamodel object __missing__7382193
Ref: 13c57382193
Ref: reference/datamodel object __iter__7382384
Ref: e6b7382384
Ref: reference/datamodel object __reversed__7382691
Ref: e887382691
Ref: reference/datamodel object __contains__7383675
Ref: 15c17383675
Node: Emulating numeric types7384240
Ref: reference/datamodel emulating-numeric-types7384394
Ref: 23ca7384394
Ref: reference/datamodel numeric-types7384394
Ref: 23cb7384394
Ref: reference/datamodel object __add__7384709
Ref: 23c37384709
Ref: reference/datamodel object __sub__7384750
Ref: 23cc7384750
Ref: reference/datamodel object __mul__7384791
Ref: 23c67384791
Ref: reference/datamodel object __matmul__7384832
Ref: f7b7384832
Ref: reference/datamodel object __truediv__7384876
Ref: 10927384876
Ref: reference/datamodel object __floordiv__7384921
Ref: 16fb7384921
Ref: reference/datamodel object __mod__7384967
Ref: 23cd7384967
Ref: reference/datamodel object __divmod__7385008
Ref: 10937385008
Ref: reference/datamodel object __pow__7385052
Ref: 9d67385052
Ref: reference/datamodel object __lshift__7385103
Ref: 23ce7385103
Ref: reference/datamodel object __rshift__7385147
Ref: 23cf7385147
Ref: reference/datamodel object __and__7385191
Ref: 23d07385191
Ref: reference/datamodel object __xor__7385232
Ref: 23d17385232
Ref: reference/datamodel object __or__7385273
Ref: 23d27385273
Ref: reference/datamodel object __radd__7386284
Ref: 23c47386284
Ref: reference/datamodel object __rsub__7386326
Ref: 23d37386326
Ref: reference/datamodel object __rmul__7386368
Ref: 23c77386368
Ref: reference/datamodel object __rmatmul__7386410
Ref: f7c7386410
Ref: reference/datamodel object __rtruediv__7386455
Ref: 23d47386455
Ref: reference/datamodel object __rfloordiv__7386501
Ref: 23d57386501
Ref: reference/datamodel object __rmod__7386548
Ref: fd77386548
Ref: reference/datamodel object __rdivmod__7386590
Ref: 23d67386590
Ref: reference/datamodel object __rpow__7386635
Ref: 1a57386635
Ref: reference/datamodel object __rlshift__7386687
Ref: 23d77386687
Ref: reference/datamodel object __rrshift__7386732
Ref: 23d87386732
Ref: reference/datamodel object __rand__7386777
Ref: 23d97386777
Ref: reference/datamodel object __rxor__7386819
Ref: 23da7386819
Ref: reference/datamodel object __ror__7386861
Ref: 23db7386861
Ref: reference/datamodel object __iadd__7388559
Ref: 23c57388559
Ref: reference/datamodel object __isub__7388601
Ref: 23dc7388601
Ref: reference/datamodel object __imul__7388643
Ref: 23c87388643
Ref: reference/datamodel object __imatmul__7388685
Ref: f7d7388685
Ref: reference/datamodel object __itruediv__7388730
Ref: 23dd7388730
Ref: reference/datamodel object __ifloordiv__7388776
Ref: 23de7388776
Ref: reference/datamodel object __imod__7388823
Ref: 23df7388823
Ref: reference/datamodel object __ipow__7388865
Ref: 9d57388865
Ref: reference/datamodel object __ilshift__7388917
Ref: 23e07388917
Ref: reference/datamodel object __irshift__7388962
Ref: 23e17388962
Ref: reference/datamodel object __iand__7389007
Ref: 23e27389007
Ref: reference/datamodel object __ixor__7389049
Ref: 23e37389049
Ref: reference/datamodel object __ior__7389091
Ref: 23e47389091
Ref: reference/datamodel object __neg__7390297
Ref: 23e67390297
Ref: reference/datamodel object __pos__7390331
Ref: 23e77390331
Ref: reference/datamodel object __abs__7390365
Ref: 23e87390365
Ref: reference/datamodel object __invert__7390399
Ref: 23e97390399
Ref: reference/datamodel object __complex__7390552
Ref: 7fe7390552
Ref: reference/datamodel object __int__7390590
Ref: 19d7390590
Ref: reference/datamodel object __float__7390624
Ref: bc37390624
Ref: reference/datamodel object __index__7390832
Ref: 19e7390832
Ref: reference/datamodel object __round__7391509
Ref: 23ea7391509
Ref: reference/datamodel object __trunc__7391556
Ref: 19c7391556
Ref: reference/datamodel object __floor__7391592
Ref: 23eb7391592
Ref: reference/datamodel object __ceil__7391628
Ref: 23ec7391628
Ref: Emulating numeric types-Footnote-17392183
Ref: Emulating numeric types-Footnote-27392501
Ref: Emulating numeric types-Footnote-37392712
Node: With Statement Context Managers7392894
Ref: reference/datamodel context-managers7393081
Ref: 23ee7393081
Ref: reference/datamodel with-statement-context-managers7393081
Ref: 23ef7393081
Ref: reference/datamodel object __enter__7393933
Ref: 7e57393933
Ref: reference/datamodel object __exit__7394183
Ref: 15087394183
Ref: With Statement Context Managers-Footnote-17395074
Node: Customizing positional arguments in class pattern matching7395116
Ref: reference/datamodel class-pattern-matching7395302
Ref: 23f17395302
Ref: reference/datamodel customizing-positional-arguments-in-class-pattern-matching7395302
Ref: 23f27395302
Ref: reference/datamodel object __match_args__7395733
Ref: 1c5d7395733
Ref: Customizing positional arguments in class pattern matching-Footnote-17396695
Node: Emulating buffer types7396737
Ref: reference/datamodel emulating-buffer-types7396903
Ref: 23f37396903
Ref: reference/datamodel python-buffer-protocol7396903
Ref: 23f47396903
Ref: reference/datamodel object __buffer__7397360
Ref: 68d7397360
Ref: reference/datamodel object __release_buffer__7397839
Ref: 1a4d7397839
Ref: Emulating buffer types-Footnote-17398582
Node: Annotations7398624
Ref: reference/datamodel annotations7398753
Ref: 23f57398753
Ref: reference/datamodel object __annotations__7398955
Ref: 4587398955
Ref: reference/datamodel object __annotate__7399372
Ref: 196b7399372
Ref: Annotations-Footnote-17400725
Node: Special method lookup7400767
Ref: reference/datamodel special-lookup7400865
Ref: 23977400865
Ref: reference/datamodel special-method-lookup7400865
Ref: 23f67400865
Node: Coroutines7403586
Ref: reference/datamodel coroutines7403672
Ref: 23f77403672
Node: Awaitable Objects7403822
Ref: reference/datamodel awaitable-objects7403912
Ref: 23f87403912
Ref: reference/datamodel object __await__7404352
Ref: f777404352
Ref: Awaitable Objects-Footnote-17405221
Node: Coroutine Objects7405263
Ref: reference/datamodel coroutine-objects7405384
Ref: 233d7405384
Ref: reference/datamodel id197405384
Ref: 23f97405384
Ref: reference/datamodel coroutine send7406266
Ref: 23fc7406266
Ref: reference/datamodel coroutine throw7406794
Ref: 71c7406794
Ref: reference/datamodel coroutine close7407586
Ref: 23fe7407586
Node: Asynchronous Iterators7408209
Ref: reference/datamodel async-iterators7408342
Ref: f797408342
Ref: reference/datamodel asynchronous-iterators7408342
Ref: 23ff7408342
Ref: reference/datamodel object __aiter__7408635
Ref: df87408635
Ref: reference/datamodel object __anext__7408725
Ref: 186a7408725
Node: Asynchronous Context Managers7409630
Ref: reference/datamodel async-context-managers7409737
Ref: 8137409737
Ref: reference/datamodel asynchronous-context-managers7409737
Ref: 24007409737
Ref: reference/datamodel object __aenter__7410111
Ref: 24017410111
Ref: reference/datamodel object __aexit__7410270
Ref: 19897410270
Node: Execution model7410748
Ref: reference/executionmodel doc7410874
Ref: 24027410874
Ref: reference/executionmodel execmodel7410874
Ref: 24037410874
Ref: reference/executionmodel execution-model7410874
Ref: 24047410874
Ref: reference/executionmodel translation-repo7410874
Ref: 24057410874
Node: Structure of a program7411013
Ref: reference/executionmodel prog-structure7411114
Ref: 24067411114
Ref: reference/executionmodel structure-of-a-program7411114
Ref: 24077411114
Node: Naming and binding7412156
Ref: reference/executionmodel naming7412276
Ref: 232d7412276
Ref: reference/executionmodel naming-and-binding7412276
Ref: 24087412276
Node: Binding of names7412500
Ref: reference/executionmodel bind-names7412599
Ref: 24097412599
Ref: reference/executionmodel binding-of-names7412599
Ref: 240a7412599
Node: Resolution of names7414371
Ref: reference/executionmodel resolution-of-names7414496
Ref: 240d7414496
Ref: reference/executionmodel resolve-names7414496
Ref: 240e7414496
Node: Annotation scopes7418377
Ref: reference/executionmodel annotation-scopes7418501
Ref: 4ac7418501
Ref: reference/executionmodel id17418501
Ref: 24107418501
Ref: Annotation scopes-Footnote-17421233
Ref: Annotation scopes-Footnote-27421275
Ref: Annotation scopes-Footnote-37421317
Ref: Annotation scopes-Footnote-47421359
Node: Lazy evaluation7421401
Ref: reference/executionmodel id27421539
Ref: 24127421539
Ref: reference/executionmodel lazy-evaluation7421539
Ref: 6867421539
Node: Builtins and restricted execution7423291
Ref: reference/executionmodel builtins-and-restricted-execution7423445
Ref: 24137423445
Ref: reference/executionmodel restrict-exec7423445
Ref: 24147423445
Node: Interaction with dynamic features7424304
Ref: reference/executionmodel dynamic-features7424434
Ref: 24157424434
Ref: reference/executionmodel interaction-with-dynamic-features7424434
Ref: 24167424434
Ref: Interaction with dynamic features-Footnote-17425227
Node: Exceptions7425365
Ref: reference/executionmodel exceptions7425481
Ref: 24177425481
Ref: reference/executionmodel id47425481
Ref: 24187425481
Node: Runtime Components7427662
Ref: reference/executionmodel execcomponents7427751
Ref: 24197427751
Ref: reference/executionmodel runtime-components7427751
Ref: 241a7427751
Node: General Computing Model7427865
Ref: reference/executionmodel general-computing-model7427972
Ref: 241b7427972
Node: Python Runtime Model7430903
Ref: reference/executionmodel python-runtime-model7431010
Ref: 241c7431010
Ref: Python Runtime Model-Footnote-17436414
Node: The import system7436473
Ref: reference/import doc7436600
Ref: 241d7436600
Ref: reference/import importsystem7436600
Ref: 23477436600
Ref: reference/import the-import-system7436600
Ref: 241e7436600
Ref: reference/import translation-repo7436600
Ref: 241f7436600
Ref: The import system-Footnote-17439228
Ref: The import system-Footnote-27439270
Ref: The import system-Footnote-37439312
Node: importlib<10>7439354
Ref: reference/import importlib7439438
Ref: 24217439438
Node: Packages7439813
Ref: reference/import packages7439915
Ref: 24227439915
Node: Regular packages7441321
Ref: reference/import regular-packages7441409
Ref: 24237441409
Node: Namespace packages7442620
Ref: reference/import namespace-packages7442708
Ref: 24257442708
Ref: reference/import reference-namespace-package7442708
Ref: 24267442708
Ref: Namespace packages-Footnote-17444085
Node: Searching7444127
Ref: reference/import searching7444223
Ref: 24287444223
Node: The module cache7445048
Ref: reference/import the-module-cache7445138
Ref: 24297445138
Node: Finders and loaders7446702
Ref: reference/import finders-and-loaders7446813
Ref: 242a7446813
Ref: reference/import id27446813
Ref: 242b7446813
Node: Import hooks7448575
Ref: reference/import import-hooks7448683
Ref: 242e7448683
Node: The meta path7449556
Ref: reference/import the-meta-path7449636
Ref: 242f7449636
Node: Loading7452864
Ref: reference/import loading7452973
Ref: 24317452973
Ref: Loading-Footnote-17456070
Node: Loaders7456450
Ref: reference/import loaders7456520
Ref: 24327456520
Node: Submodules7459788
Ref: reference/import submodules7459879
Ref: 24337459879
Node: Module specs7461111
Ref: reference/import id47461225
Ref: 24347461225
Ref: reference/import module-specs7461225
Ref: 234d7461225
Node: __path__ attributes on modules7462266
Ref: reference/import package-path-rules7462382
Ref: 234e7462382
Ref: reference/import path-attributes-on-modules7462382
Ref: 24377462382
Ref: __path__ attributes on modules-Footnote-17463715
Ref: __path__ attributes on modules-Footnote-27463757
Node: Module reprs7463799
Ref: reference/import module-reprs7463931
Ref: 24387463931
Node: Cached bytecode invalidation7465342
Ref: reference/import cached-bytecode-invalidation7465435
Ref: 24397465435
Ref: reference/import pyc-invalidation7465435
Ref: 8037465435
Node: The Path Based Finder7466787
Ref: reference/import the-path-based-finder7466923
Ref: 243a7466923
Node: Path entry finders7469431
Ref: reference/import path-entry-finders7469542
Ref: 243c7469542
Node: Path entry finder protocol7474504
Ref: reference/import path-entry-finder-protocol7474615
Ref: 243e7474615
Node: Replacing the standard import system7477005
Ref: reference/import replacing-the-standard-import-system7477158
Ref: 243f7477158
Node: Package Relative Imports7478035
Ref: reference/import package-relative-imports7478202
Ref: 24407478202
Ref: reference/import relativeimports7478202
Ref: 24417478202
Node: Special considerations for __main__7479405
Ref: reference/import import-dunder-main7479546
Ref: 24427479546
Ref: reference/import special-considerations-for-main7479546
Ref: 24437479546
Node: __main__ __spec__7480149
Ref: reference/import id57480238
Ref: 24447480238
Ref: reference/import main-spec7480238
Ref: 24367480238
Node: References7481635
Ref: reference/import references7481743
Ref: 24457481743
Ref: References-Footnote-17482973
Ref: References-Footnote-27483025
Ref: References-Footnote-37483067
Ref: References-Footnote-47483109
Ref: References-Footnote-57483151
Ref: References-Footnote-67483193
Ref: References-Footnote-77483235
Ref: References-Footnote-87483277
Ref: References-Footnote-97483319
Ref: References-Footnote-107483361
Node: Expressions7483404
Ref: reference/expressions doc7483533
Ref: 24467483533
Ref: reference/expressions expressions7483533
Ref: 23107483533
Ref: reference/expressions id17483533
Ref: 24477483533
Ref: reference/expressions translation-repo7483533
Ref: 24487483533
Ref: reference/expressions grammar-token-python-grammar-name7483827
Ref: 24497483827
Node: Arithmetic conversions7484390
Ref: reference/expressions arithmetic-conversions7484474
Ref: 244a7484474
Ref: reference/expressions conversions7484474
Ref: 244b7484474
Node: Atoms7485178
Ref: reference/expressions atoms7485280
Ref: 244c7485280
Ref: reference/expressions id27485280
Ref: 244d7485280
Ref: reference/expressions grammar-token-python-grammar-atom7485527
Ref: 244e7485527
Ref: reference/expressions grammar-token-python-grammar-enclosure7485615
Ref: 24507485615
Node: Identifiers Names7486114
Ref: reference/expressions atom-identifiers7486193
Ref: 22af7486193
Ref: reference/expressions identifiers-names7486193
Ref: 24577486193
Ref: reference/expressions private-name-mangling7486640
Ref: 208d7486640
Node: Private name mangling7486676
Ref: reference/expressions id37486751
Ref: 24587486751
Node: Literals<2>7488540
Ref: reference/expressions atom-literals7488647
Ref: 24597488647
Ref: reference/expressions literals7488647
Ref: 245a7488647
Ref: reference/expressions grammar-token-python-grammar-literal7488755
Ref: 244f7488755
Node: String literal concatenation7489547
Ref: reference/expressions string-concatenation7489623
Ref: 22c97489623
Ref: reference/expressions string-literal-concatenation7489623
Ref: 245c7489623
Ref: reference/expressions grammar-token-python-grammar-strings7489937
Ref: 245b7489937
Node: Parenthesized forms7491145
Ref: reference/expressions parenthesized7491275
Ref: 245d7491275
Ref: reference/expressions parenthesized-forms7491275
Ref: 245e7491275
Ref: reference/expressions grammar-token-python-grammar-parenth_form7491410
Ref: 24517491410
Node: Displays for lists sets and dictionaries7492173
Ref: reference/expressions comprehensions7492305
Ref: 7ed7492305
Ref: reference/expressions displays-for-lists-sets-and-dictionaries7492305
Ref: 24607492305
Ref: reference/expressions grammar-token-python-grammar-comprehension7492749
Ref: 24617492749
Ref: reference/expressions grammar-token-python-grammar-comp_for7492826
Ref: 24627492826
Ref: reference/expressions grammar-token-python-grammar-comp_iter7492938
Ref: 24657492938
Ref: reference/expressions grammar-token-python-grammar-comp_if7493003
Ref: 24667493003
Ref: Displays for lists sets and dictionaries-Footnote-17495510
Node: List displays7495552
Ref: reference/expressions list-displays7495677
Ref: 24677495677
Ref: reference/expressions lists7495677
Ref: 24687495677
Ref: reference/expressions grammar-token-python-grammar-list_display7495809
Ref: 24527495809
Node: Set displays7496290
Ref: reference/expressions set7496394
Ref: 246a7496394
Ref: reference/expressions set-displays7496394
Ref: 246b7496394
Ref: reference/expressions grammar-token-python-grammar-set_display7496574
Ref: 24547496574
Node: Dictionary displays7497141
Ref: reference/expressions dict7497253
Ref: f817497253
Ref: reference/expressions dictionary-displays7497253
Ref: 246c7497253
Ref: reference/expressions grammar-token-python-grammar-dict_display7497417
Ref: 24537497417
Ref: reference/expressions grammar-token-python-grammar-dict_item_list7497514
Ref: 246d7497514
Ref: reference/expressions grammar-token-python-grammar-dict_item7497598
Ref: 246f7497598
Ref: reference/expressions grammar-token-python-grammar-dict_comprehension7497701
Ref: 246e7497701
Ref: Dictionary displays-Footnote-17499541
Ref: Dictionary displays-Footnote-27499583
Node: Generator expressions7499625
Ref: reference/expressions generator-expressions7499742
Ref: 24707499742
Ref: reference/expressions genexpr7499742
Ref: 24717499742
Ref: reference/expressions grammar-token-python-grammar-generator_expression7499877
Ref: 24557499877
Node: Yield expressions7501947
Ref: reference/expressions yield-expressions7502036
Ref: 24727502036
Ref: reference/expressions yieldexpr7502036
Ref: 24737502036
Ref: reference/expressions grammar-token-python-grammar-yield_atom7502091
Ref: 24567502091
Ref: reference/expressions grammar-token-python-grammar-yield_from7502152
Ref: 24747502152
Ref: reference/expressions grammar-token-python-grammar-yield_expression7502213
Ref: 22ec7502213
Ref: Yield expressions-Footnote-17507225
Ref: Yield expressions-Footnote-27507267
Ref: Yield expressions-Footnote-37507309
Ref: Yield expressions-Footnote-47507351
Ref: Yield expressions-Footnote-57507393
Node: Generator-iterator methods7507435
Ref: reference/expressions generator-iterator-methods7507532
Ref: 24787507532
Ref: reference/expressions generator-methods7507532
Ref: 23fb7507532
Ref: reference/expressions generator __next__7507874
Ref: 20987507874
Ref: reference/expressions generator send7508632
Ref: 23fd7508632
Ref: reference/expressions generator throw7509212
Ref: 71d7509212
Ref: reference/expressions generator close7510509
Ref: 177b7510509
Node: Examples7511551
Ref: reference/expressions examples7511692
Ref: 24797511692
Node: Asynchronous generator functions<2>7512750
Ref: reference/expressions asynchronous-generator-functions7512904
Ref: 24777512904
Ref: reference/expressions id47512904
Ref: 247a7512904
Ref: Asynchronous generator functions<2>-Footnote-17516575
Node: Asynchronous generator-iterator methods7516655
Ref: reference/expressions asynchronous-generator-iterator-methods7516792
Ref: 247c7516792
Ref: reference/expressions asynchronous-generator-methods7516792
Ref: 247d7516792
Ref: reference/expressions agen __anext__7517034
Ref: 247b7517034
Ref: reference/expressions agen asend7517956
Ref: ad87517956
Ref: reference/expressions agen athrow7518813
Ref: 71e7518813
Ref: reference/expressions agen aclose7519696
Ref: ad77519696
Node: Primaries7520708
Ref: reference/expressions id57520804
Ref: 247e7520804
Ref: reference/expressions primaries7520804
Ref: 247f7520804
Ref: reference/expressions grammar-token-python-grammar-primary7520926
Ref: 24807520926
Node: Attribute references7521134
Ref: reference/expressions attribute-references7521222
Ref: 24857521222
Ref: reference/expressions id67521222
Ref: 24867521222
Ref: reference/expressions grammar-token-python-grammar-attributeref7521351
Ref: 24817521351
Node: Subscriptions7522165
Ref: reference/expressions id77522270
Ref: 24877522270
Ref: reference/expressions subscriptions7522270
Ref: 23b47522270
Ref: reference/expressions grammar-token-python-grammar-subscription7522541
Ref: 24827522541
Ref: Subscriptions-Footnote-17525208
Node: Slicings7525250
Ref: reference/expressions id87525340
Ref: 24887525340
Ref: reference/expressions slicings7525340
Ref: 24897525340
Ref: reference/expressions grammar-token-python-grammar-slicing7525589
Ref: 24837525589
Ref: reference/expressions grammar-token-python-grammar-slice_list7525661
Ref: 248a7525661
Ref: reference/expressions grammar-token-python-grammar-slice_item7525741
Ref: 248b7525741
Ref: reference/expressions grammar-token-python-grammar-proper_slice7525811
Ref: 248c7525811
Ref: reference/expressions grammar-token-python-grammar-lower_bound7525918
Ref: 248d7525918
Ref: reference/expressions grammar-token-python-grammar-upper_bound7525960
Ref: 248e7525960
Ref: reference/expressions grammar-token-python-grammar-stride7526002
Ref: 248f7526002
Node: Calls7527249
Ref: reference/expressions calls7527317
Ref: f7f7527317
Ref: reference/expressions id97527317
Ref: 24907527317
Ref: reference/expressions grammar-token-python-grammar-call7527465
Ref: 24847527465
Ref: reference/expressions grammar-token-python-grammar-argument_list7527585
Ref: 24927527585
Ref: reference/expressions grammar-token-python-grammar-positional_arguments7527915
Ref: 24937527915
Ref: reference/expressions grammar-token-python-grammar-positional_item7528007
Ref: 24967528007
Ref: reference/expressions grammar-token-python-grammar-starred_and_keywords7528098
Ref: 24947528098
Ref: reference/expressions grammar-token-python-grammar-keywords_arguments7528275
Ref: 24957528275
Ref: reference/expressions grammar-token-python-grammar-keyword_item7528454
Ref: 24977528454
Ref: Calls-Footnote-17535253
Node: Await expression7535295
Ref: reference/expressions await7535404
Ref: 18d7535404
Ref: reference/expressions await-expression7535404
Ref: 24987535404
Ref: reference/expressions grammar-token-python-grammar-await_expr7535593
Ref: 24997535593
Node: The power operator7535663
Ref: reference/expressions power7535802
Ref: 249a7535802
Ref: reference/expressions the-power-operator7535802
Ref: 249b7535802
Ref: reference/expressions grammar-token-python-grammar-power7535999
Ref: 249c7535999
Node: Unary arithmetic and bitwise operations7537194
Ref: reference/expressions unary7537345
Ref: 249e7537345
Ref: reference/expressions unary-arithmetic-and-bitwise-operations7537345
Ref: 249f7537345
Ref: reference/expressions grammar-token-python-grammar-u_expr7537507
Ref: 249d7537507
Node: Binary arithmetic operations7538316
Ref: reference/expressions binary7538468
Ref: 24a07538468
Ref: reference/expressions binary-arithmetic-operations7538468
Ref: 24a17538468
Ref: reference/expressions grammar-token-python-grammar-m_expr7538812
Ref: 24a27538812
Ref: reference/expressions grammar-token-python-grammar-a_expr7539102
Ref: 24a37539102
Ref: Binary arithmetic operations-Footnote-17543277
Ref: Binary arithmetic operations-Footnote-27543890
Node: Shifting operations7544173
Ref: reference/expressions shifting7544311
Ref: 24a57544311
Ref: reference/expressions shifting-operations7544311
Ref: 24a67544311
Ref: reference/expressions grammar-token-python-grammar-shift_expr7544441
Ref: 24a77544441
Node: Binary bitwise operations7545098
Ref: reference/expressions binary-bitwise-operations7545219
Ref: 24a87545219
Ref: reference/expressions bitwise7545219
Ref: 24a97545219
Ref: reference/expressions grammar-token-python-grammar-and_expr7545354
Ref: 24aa7545354
Ref: reference/expressions grammar-token-python-grammar-xor_expr7545445
Ref: 24ab7545445
Ref: reference/expressions grammar-token-python-grammar-or_expr7545532
Ref: 22eb7545532
Node: Comparisons7546252
Ref: reference/expressions comparisons7546372
Ref: 24ac7546372
Ref: reference/expressions id127546372
Ref: 24ad7546372
Ref: reference/expressions grammar-token-python-grammar-comparison7546667
Ref: 24ae7546667
Ref: reference/expressions grammar-token-python-grammar-comp_operator7546759
Ref: 24af7546759
Node: Value comparisons7547843
Ref: reference/expressions expressions-value-comparisons7547943
Ref: 1c087547943
Ref: reference/expressions value-comparisons7547943
Ref: 24b07547943
Ref: reference/expressions in7555802
Ref: 34b7555802
Ref: reference/expressions not-in7555802
Ref: 8427555802
Ref: Value comparisons-Footnote-17555840
Ref: Value comparisons-Footnote-27555882
Node: Membership test operations7556985
Ref: reference/expressions membership-test-details7557114
Ref: 23c97557114
Ref: reference/expressions membership-test-operations7557114
Ref: 24b17557114
Ref: reference/expressions is7559007
Ref: 34c7559007
Node: Identity comparisons7559007
Ref: reference/expressions identity-comparisons7559110
Ref: 24b27559110
Ref: reference/expressions is-not7559110
Ref: 24b37559110
Ref: reference/expressions booleans7559456
Ref: 24b47559456
Ref: reference/expressions and7559456
Ref: 3497559456
Ref: reference/expressions or7559456
Ref: 34d7559456
Ref: Identity comparisons-Footnote-17559494
Node: Boolean operations7559796
Ref: reference/expressions boolean-operations7559916
Ref: 24b57559916
Ref: reference/expressions not7559916
Ref: 24b67559916
Ref: reference/expressions grammar-token-python-grammar-or_test7559969
Ref: 24647559969
Ref: reference/expressions grammar-token-python-grammar-and_test7560056
Ref: 24b77560056
Ref: reference/expressions grammar-token-python-grammar-not_test7560145
Ref: 24b87560145
Node: Assignment expressions<2>7561610
Ref: reference/expressions assignment-expressions7561742
Ref: 24b97561742
Ref: reference/expressions id157561742
Ref: 24ba7561742
Ref: reference/expressions grammar-token-python-grammar-assignment_expression7561803
Ref: 24117561803
Ref: Assignment expressions<2>-Footnote-17562870
Node: Conditional expressions7562912
Ref: reference/expressions conditional-expressions7563033
Ref: 24bb7563033
Ref: reference/expressions if-expr7563033
Ref: 17d7563033
Ref: reference/expressions grammar-token-python-grammar-conditional_expression7563096
Ref: 22ea7563096
Ref: reference/expressions grammar-token-python-grammar-expression7563204
Ref: 1827563204
Ref: reference/expressions lambdas7563755
Ref: 24bd7563755
Ref: Conditional expressions-Footnote-17563793
Node: Lambdas7563835
Ref: reference/expressions id167563947
Ref: 24be7563947
Ref: reference/expressions lambda7563947
Ref: 14a57563947
Ref: reference/expressions grammar-token-python-grammar-lambda_expr7563978
Ref: 24bc7563978
Node: Expression lists7564534
Ref: reference/expressions expression-lists7564639
Ref: 24c07564639
Ref: reference/expressions exprlists7564639
Ref: f807564639
Ref: reference/expressions grammar-token-python-grammar-starred_expression7564688
Ref: 245f7564688
Ref: reference/expressions grammar-token-python-grammar-flexible_expression7564769
Ref: 24c17564769
Ref: reference/expressions grammar-token-python-grammar-flexible_expression_list7564869
Ref: 24697564869
Ref: reference/expressions grammar-token-python-grammar-starred_expression_list7564979
Ref: 24c27564979
Ref: reference/expressions grammar-token-python-grammar-expression_list7565087
Ref: 24c37565087
Ref: reference/expressions grammar-token-python-grammar-yield_list7565177
Ref: 24757565177
Ref: Expression lists-Footnote-17566302
Ref: Expression lists-Footnote-27566344
Node: Evaluation order7566386
Ref: reference/expressions evalorder7566503
Ref: 24c47566503
Ref: reference/expressions evaluation-order7566503
Ref: 24c57566503
Node: Operator precedence7567018
Ref: reference/expressions operator-precedence7567110
Ref: 24c67567110
Ref: reference/expressions operator-summary7567110
Ref: 24c77567110
Ref: Operator precedence-Footnote-17571628
Ref: Operator precedence-Footnote-27571777
Node: Simple statements7571871
Ref: reference/simple_stmts doc7572002
Ref: 24c87572002
Ref: reference/simple_stmts simple7572002
Ref: 24c97572002
Ref: reference/simple_stmts simple-statements7572002
Ref: 24ca7572002
Ref: reference/simple_stmts translation-repo7572002
Ref: 24cb7572002
Ref: reference/simple_stmts grammar-token-python-grammar-simple_stmt7572226
Ref: 24cc7572226
Node: Expression statements7573376
Ref: reference/simple_stmts expression-statements7573481
Ref: 24de7573481
Ref: reference/simple_stmts exprstmts7573481
Ref: 24df7573481
Ref: reference/simple_stmts grammar-token-python-grammar-expression_stmt7573871
Ref: 24cd7573871
Node: Assignment statements7574308
Ref: reference/simple_stmts assignment7574442
Ref: 240b7574442
Ref: reference/simple_stmts assignment-statements7574442
Ref: 24e07574442
Ref: reference/simple_stmts grammar-token-python-grammar-assignment_stmt7574613
Ref: 24cf7574613
Ref: reference/simple_stmts grammar-token-python-grammar-target_list7574733
Ref: 24637574733
Ref: reference/simple_stmts grammar-token-python-grammar-target7574808
Ref: 24e17574808
Ref: reference/simple_stmts attr-target-note7578328
Ref: 24e27578328
Ref: Assignment statements-Footnote-17582410
Node: Augmented assignment statements7582452
Ref: reference/simple_stmts augassign7582581
Ref: 24e37582581
Ref: reference/simple_stmts augmented-assignment-statements7582581
Ref: 24e47582581
Ref: reference/simple_stmts grammar-token-python-grammar-augmented_assignment_stmt7582778
Ref: 24d07582778
Ref: reference/simple_stmts grammar-token-python-grammar-augtarget7582915
Ref: 24e57582915
Ref: reference/simple_stmts grammar-token-python-grammar-augop7583050
Ref: 24e67583050
Node: Annotated assignment statements7584785
Ref: reference/simple_stmts annassign7584914
Ref: 24e77584914
Ref: reference/simple_stmts annotated-assignment-statements7584914
Ref: 24e87584914
Ref: reference/simple_stmts grammar-token-python-grammar-annotated_assignment_stmt7585149
Ref: 24d17585149
Ref: Annotated assignment statements-Footnote-17587358
Ref: Annotated assignment statements-Footnote-27587400
Node: The assert statement7587442
Ref: reference/simple_stmts assert7587573
Ref: b627587573
Ref: reference/simple_stmts the-assert-statement7587573
Ref: 24e97587573
Ref: reference/simple_stmts grammar-token-python-grammar-assert_stmt7587723
Ref: 24ce7587723
Node: The pass statement7588833
Ref: reference/simple_stmts pass7588960
Ref: 17e7588960
Ref: reference/simple_stmts the-pass-statement7588960
Ref: 24ea7588960
Ref: reference/simple_stmts grammar-token-python-grammar-pass_stmt7589019
Ref: 24d27589019
Node: The del statement7589366
Ref: reference/simple_stmts del7589493
Ref: 1b077589493
Ref: reference/simple_stmts the-del-statement7589493
Ref: 24eb7589493
Ref: reference/simple_stmts grammar-token-python-grammar-del_stmt7589550
Ref: 24d37589550
Node: The return statement7590486
Ref: reference/simple_stmts return7590614
Ref: 1af7590614
Ref: reference/simple_stmts the-return-statement7590614
Ref: 24ec7590614
Ref: reference/simple_stmts grammar-token-python-grammar-return_stmt7590677
Ref: 24d47590677
Node: The yield statement7591819
Ref: reference/simple_stmts the-yield-statement7591949
Ref: 24ed7591949
Ref: reference/simple_stmts yield7591949
Ref: bc47591949
Ref: reference/simple_stmts grammar-token-python-grammar-yield_stmt7592010
Ref: 24d57592010
Node: The raise statement7592874
Ref: reference/simple_stmts raise7593003
Ref: 8047593003
Ref: reference/simple_stmts the-raise-statement7593003
Ref: 24ee7593003
Ref: reference/simple_stmts grammar-token-python-grammar-raise_stmt7593064
Ref: 24d67593064
Node: The break statement7597301
Ref: reference/simple_stmts break7597433
Ref: 17f7597433
Ref: reference/simple_stmts the-break-statement7597433
Ref: 24f17597433
Ref: reference/simple_stmts grammar-token-python-grammar-break_stmt7597494
Ref: 24d77597494
Node: The continue statement7598085
Ref: reference/simple_stmts continue7598218
Ref: 1807598218
Ref: reference/simple_stmts the-continue-statement7598218
Ref: 24f27598218
Ref: reference/simple_stmts grammar-token-python-grammar-continue_stmt7598287
Ref: 24d87598287
Ref: reference/simple_stmts import7598750
Ref: 7f97598750
Node: The import statement7598752
Ref: reference/simple_stmts from7598886
Ref: 14b37598886
Ref: reference/simple_stmts the-import-statement7598886
Ref: 24f37598886
Ref: reference/simple_stmts grammar-token-python-grammar-import_stmt7598951
Ref: 24d97598951
Ref: reference/simple_stmts grammar-token-python-grammar-module7599594
Ref: 24f47599594
Ref: reference/simple_stmts grammar-token-python-grammar-relative_module7599671
Ref: 24f57599671
Ref: reference/simple_stmts module __all__7602837
Ref: f3d7602837
Node: Future statements7605008
Ref: reference/simple_stmts future7605082
Ref: 45d7605082
Ref: reference/simple_stmts future-statements7605082
Ref: 24f67605082
Ref: reference/simple_stmts grammar-token-python-grammar-future_stmt7605608
Ref: 24da7605608
Ref: reference/simple_stmts grammar-token-python-grammar-feature7605976
Ref: 24f77605976
Ref: Future statements-Footnote-17608708
Ref: Future statements-Footnote-27608750
Node: The global statement7608792
Ref: reference/simple_stmts global7608926
Ref: 4ad7608926
Ref: reference/simple_stmts the-global-statement7608926
Ref: 24f87608926
Ref: reference/simple_stmts grammar-token-python-grammar-global_stmt7608991
Ref: 24db7608991
Node: The nonlocal statement7610361
Ref: reference/simple_stmts nonlocal7610493
Ref: 14af7610493
Ref: reference/simple_stmts the-nonlocal-statement7610493
Ref: 24f97610493
Ref: reference/simple_stmts grammar-token-python-grammar-nonlocal_stmt7610562
Ref: 24dc7610562
Ref: The nonlocal statement-Footnote-17611775
Node: The type statement7611817
Ref: reference/simple_stmts the-type-statement7611920
Ref: 24fa7611920
Ref: reference/simple_stmts type7611920
Ref: 66d7611920
Ref: reference/simple_stmts grammar-token-python-grammar-type_stmt7611981
Ref: 24dd7611981
Ref: The type statement-Footnote-17613311
Node: Compound statements7613353
Ref: reference/compound_stmts doc7613493
Ref: 24fc7613493
Ref: reference/compound_stmts compound7613493
Ref: 24fd7613493
Ref: reference/compound_stmts compound-statements7613493
Ref: 24fe7613493
Ref: reference/compound_stmts translation-repo7613493
Ref: 24ff7613493
Ref: reference/compound_stmts grammar-token-python-grammar-compound_stmt7615263
Ref: 25007615263
Ref: reference/compound_stmts grammar-token-python-grammar-suite7615766
Ref: 250c7615766
Ref: reference/compound_stmts grammar-token-python-grammar-statement7615865
Ref: 250e7615865
Ref: reference/compound_stmts grammar-token-python-grammar-stmt_list7615945
Ref: 250d7615945
Ref: reference/compound_stmts if7616493
Ref: 1817616493
Ref: reference/compound_stmts elif7616493
Ref: 17b7616493
Node: The if statement7616772
Ref: reference/compound_stmts else7616872
Ref: 17c7616872
Ref: reference/compound_stmts the-if-statement7616872
Ref: 250f7616872
Ref: reference/compound_stmts grammar-token-python-grammar-if_stmt7616992
Ref: 25017616992
Node: The while statement7617595
Ref: reference/compound_stmts the-while-statement7617721
Ref: 25107617721
Ref: reference/compound_stmts while7617721
Ref: 195b7617721
Ref: reference/compound_stmts grammar-token-python-grammar-while_stmt7617881
Ref: 25027617881
Node: The for statement7618514
Ref: reference/compound_stmts for7618641
Ref: 34a7618641
Ref: reference/compound_stmts the-for-statement7618641
Ref: 25117618641
Ref: reference/compound_stmts grammar-token-python-grammar-for_stmt7618840
Ref: 25037618840
Node: The try statement7620674
Ref: reference/compound_stmts the-try-statement7620800
Ref: 25127620800
Ref: reference/compound_stmts try7620800
Ref: 8f97620800
Ref: reference/compound_stmts grammar-token-python-grammar-try_stmt7620958
Ref: 25047620958
Ref: reference/compound_stmts grammar-token-python-grammar-try1_stmt7621047
Ref: 25137621047
Ref: reference/compound_stmts grammar-token-python-grammar-try2_stmt7621298
Ref: 25147621298
Ref: reference/compound_stmts grammar-token-python-grammar-try3_stmt7621551
Ref: 25157621551
Ref: The try statement-Footnote-17622124
Node: except clause7622166
Ref: reference/compound_stmts except7622256
Ref: 1ab7622256
Ref: reference/compound_stmts except-clause7622256
Ref: 25167622256
Ref: except clause-Footnote-17625612
Node: except* clause7625810
Ref: reference/compound_stmts except-star7625920
Ref: 1ac7625920
Ref: reference/compound_stmts id27625920
Ref: 25177625920
Node: else clause7628930
Ref: reference/compound_stmts else-clause7629041
Ref: 25187629041
Ref: reference/compound_stmts except-else7629041
Ref: 25197629041
Node: finally clause7629402
Ref: reference/compound_stmts finally7629490
Ref: 1b07629490
Ref: reference/compound_stmts finally-clause7629490
Ref: 251a7629490
Ref: reference/compound_stmts with7631430
Ref: 1867631430
Ref: finally clause-Footnote-17631466
Node: The with statement7631508
Ref: reference/compound_stmts as7631636
Ref: 251b7631636
Ref: reference/compound_stmts the-with-statement7631636
Ref: 251c7631636
Ref: reference/compound_stmts grammar-token-python-grammar-with_stmt7632005
Ref: 25057632005
Ref: reference/compound_stmts grammar-token-python-grammar-with_stmt_contents7632143
Ref: 251d7632143
Ref: reference/compound_stmts grammar-token-python-grammar-with_item7632221
Ref: 251e7632221
Ref: reference/compound_stmts match7635427
Ref: a107635427
Ref: The with statement-Footnote-17635463
Node: The match statement7635505
Ref: reference/compound_stmts case7635636
Ref: 251f7635636
Ref: reference/compound_stmts the-match-statement7635636
Ref: 25207635636
Ref: reference/compound_stmts grammar-token-python-grammar-match_stmt7635781
Ref: 25067635781
Ref: reference/compound_stmts grammar-token-python-grammar-subject_expr7635885
Ref: 25217635885
Ref: reference/compound_stmts grammar-token-python-grammar-case_block7636001
Ref: 25227636001
Ref: The match statement-Footnote-17636906
Ref: The match statement-Footnote-27636948
Node: Overview7636990
Ref: reference/compound_stmts overview7637069
Ref: 25257637069
Node: Guards7639541
Ref: reference/compound_stmts guards7639652
Ref: 25277639652
Ref: reference/compound_stmts grammar-token-python-grammar-guard7639683
Ref: 25247639683
Node: Irrefutable Case Blocks7640814
Ref: reference/compound_stmts irrefutable-case7640925
Ref: 25287640925
Ref: reference/compound_stmts irrefutable-case-blocks7640925
Ref: 25297640925
Node: Patterns7641630
Ref: reference/compound_stmts patterns7641726
Ref: 252d7641726
Ref: reference/compound_stmts grammar-token-python-grammar-patterns7642050
Ref: 25237642050
Ref: reference/compound_stmts grammar-token-python-grammar-pattern7642129
Ref: 252f7642129
Ref: reference/compound_stmts grammar-token-python-grammar-closed_pattern7642200
Ref: 25327642200
Node: OR Patterns7643194
Ref: reference/compound_stmts id37643270
Ref: 253b7643270
Ref: reference/compound_stmts or-patterns7643270
Ref: 252b7643270
Ref: reference/compound_stmts grammar-token-python-grammar-or_pattern7643394
Ref: 25317643394
Node: AS Patterns7643958
Ref: reference/compound_stmts as-patterns7644059
Ref: 252a7644059
Ref: reference/compound_stmts id47644059
Ref: 253c7644059
Ref: reference/compound_stmts grammar-token-python-grammar-as_pattern7644208
Ref: 25307644208
Node: Literal Patterns7644587
Ref: reference/compound_stmts id57644693
Ref: 253d7644693
Ref: reference/compound_stmts literal-patterns7644693
Ref: 253e7644693
Ref: reference/compound_stmts grammar-token-python-grammar-literal_pattern7644824
Ref: 25337644824
Ref: reference/compound_stmts grammar-token-python-grammar-signed_number7645136
Ref: 253f7645136
Node: Capture Patterns7645831
Ref: reference/compound_stmts capture-patterns7645943
Ref: 252c7645943
Ref: reference/compound_stmts id67645943
Ref: 25417645943
Ref: reference/compound_stmts grammar-token-python-grammar-capture_pattern7646057
Ref: 25347646057
Ref: Capture Patterns-Footnote-17646797
Node: Wildcard Patterns7646839
Ref: reference/compound_stmts id77646949
Ref: 25427646949
Ref: reference/compound_stmts wildcard-patterns7646949
Ref: a117646949
Ref: reference/compound_stmts grammar-token-python-grammar-wildcard_pattern7647084
Ref: 25357647084
Node: Value Patterns7647358
Ref: reference/compound_stmts id87647466
Ref: 25437647466
Ref: reference/compound_stmts value-patterns7647466
Ref: 25447647466
Ref: reference/compound_stmts grammar-token-python-grammar-value_pattern7647577
Ref: 25367647577
Ref: reference/compound_stmts grammar-token-python-grammar-attr7647615
Ref: 25457647615
Ref: reference/compound_stmts grammar-token-python-grammar-name_or_attr7647670
Ref: 25467647670
Node: Group Patterns7648293
Ref: reference/compound_stmts group-patterns7648401
Ref: 25477648401
Ref: reference/compound_stmts id97648401
Ref: 25487648401
Ref: reference/compound_stmts grammar-token-python-grammar-group_pattern7648601
Ref: 25377648601
Node: Sequence Patterns7648710
Ref: reference/compound_stmts id107648820
Ref: 25497648820
Ref: reference/compound_stmts sequence-patterns7648820
Ref: 254a7648820
Ref: reference/compound_stmts grammar-token-python-grammar-sequence_pattern7649025
Ref: 25387649025
Ref: reference/compound_stmts grammar-token-python-grammar-open_sequence_pattern7649176
Ref: 252e7649176
Ref: reference/compound_stmts grammar-token-python-grammar-maybe_sequence_pattern7649279
Ref: 254b7649279
Ref: reference/compound_stmts grammar-token-python-grammar-maybe_star_pattern7649350
Ref: 254c7649350
Ref: reference/compound_stmts grammar-token-python-grammar-star_pattern7649428
Ref: 254d7649428
Ref: Sequence Patterns-Footnote-17652448
Node: Mapping Patterns7653165
Ref: reference/compound_stmts id127653275
Ref: 254e7653275
Ref: reference/compound_stmts mapping-patterns7653275
Ref: 254f7653275
Ref: reference/compound_stmts grammar-token-python-grammar-mapping_pattern7653457
Ref: 25397653457
Ref: reference/compound_stmts grammar-token-python-grammar-items_pattern7653520
Ref: 25507653520
Ref: reference/compound_stmts grammar-token-python-grammar-key_value_pattern7653587
Ref: 25517653587
Ref: reference/compound_stmts grammar-token-python-grammar-double_star_pattern7653759
Ref: 25527653759
Ref: Mapping Patterns-Footnote-17655370
Node: Class Patterns7655844
Ref: reference/compound_stmts class-patterns7655928
Ref: 25537655928
Ref: reference/compound_stmts id147655928
Ref: 25547655928
Ref: reference/compound_stmts grammar-token-python-grammar-class_pattern7656073
Ref: 253a7656073
Ref: reference/compound_stmts grammar-token-python-grammar-pattern_arguments7656171
Ref: 25557656171
Ref: reference/compound_stmts grammar-token-python-grammar-positional_patterns7656324
Ref: 25567656324
Ref: reference/compound_stmts grammar-token-python-grammar-keyword_patterns7656376
Ref: 25577656376
Ref: reference/compound_stmts grammar-token-python-grammar-keyword_pattern7656436
Ref: 25587656436
Ref: reference/compound_stmts function7660506
Ref: 20027660506
Ref: Class Patterns-Footnote-17660542
Ref: Class Patterns-Footnote-27660584
Node: Function definitions7660626
Ref: reference/compound_stmts def7660756
Ref: 16617660756
Ref: reference/compound_stmts function-definitions7660756
Ref: 25597660756
Ref: reference/compound_stmts grammar-token-python-grammar-funcdef7660929
Ref: 25077660929
Ref: reference/compound_stmts grammar-token-python-grammar-decorators7661165
Ref: 255a7661165
Ref: reference/compound_stmts grammar-token-python-grammar-decorator7661221
Ref: 255c7661221
Ref: reference/compound_stmts grammar-token-python-grammar-parameter_list7661300
Ref: 24bf7661300
Ref: reference/compound_stmts grammar-token-python-grammar-parameter_list_no_posonly7661521
Ref: 255e7661521
Ref: reference/compound_stmts grammar-token-python-grammar-parameter_list_starargs7661728
Ref: 255f7661728
Ref: reference/compound_stmts grammar-token-python-grammar-parameter_star_kwargs7662053
Ref: 25617662053
Ref: reference/compound_stmts grammar-token-python-grammar-parameter7662119
Ref: 25627662119
Ref: reference/compound_stmts grammar-token-python-grammar-star_parameter7662204
Ref: 25607662204
Ref: reference/compound_stmts grammar-token-python-grammar-defparameter7662295
Ref: 255d7662295
Ref: reference/compound_stmts grammar-token-python-grammar-funcname7662379
Ref: 255b7662379
Ref: Function definitions-Footnote-17668975
Ref: Function definitions-Footnote-27669176
Ref: Function definitions-Footnote-37669218
Ref: Function definitions-Footnote-47669260
Ref: Function definitions-Footnote-57669302
Ref: Function definitions-Footnote-67669344
Ref: Function definitions-Footnote-77669386
Ref: Function definitions-Footnote-87669428
Ref: Function definitions-Footnote-97669470
Ref: Function definitions-Footnote-107669512
Node: Class definitions7669555
Ref: reference/compound_stmts class7669679
Ref: 14df7669679
Ref: reference/compound_stmts class-definitions7669679
Ref: 25647669679
Ref: reference/compound_stmts grammar-token-python-grammar-classdef7669827
Ref: 25087669827
Ref: reference/compound_stmts grammar-token-python-grammar-inheritance7669979
Ref: 25667669979
Ref: reference/compound_stmts grammar-token-python-grammar-classname7670034
Ref: 25657670034
Ref: Class definitions-Footnote-17673357
Ref: Class definitions-Footnote-27673548
Ref: Class definitions-Footnote-37673590
Ref: Class definitions-Footnote-47673632
Ref: Class definitions-Footnote-57673674
Node: Coroutines<2>7673716
Ref: reference/compound_stmts async7673840
Ref: 93c7673840
Ref: reference/compound_stmts coroutines7673840
Ref: 25677673840
Node: Coroutine function definition7673999
Ref: reference/compound_stmts async-def7674110
Ref: 7ee7674110
Ref: reference/compound_stmts coroutine-function-definition7674110
Ref: 25687674110
Ref: reference/compound_stmts grammar-token-python-grammar-async_funcdef7674187
Ref: 250b7674187
Node: The async for statement7675162
Ref: reference/compound_stmts async-for7675306
Ref: ca37675306
Ref: reference/compound_stmts the-async-for-statement7675306
Ref: 25697675306
Ref: reference/compound_stmts grammar-token-python-grammar-async_for_stmt7675379
Ref: 250a7675379
Node: The async with statement7676324
Ref: reference/compound_stmts async-with7676430
Ref: 1857676430
Ref: reference/compound_stmts the-async-with-statement7676430
Ref: 256a7676430
Ref: reference/compound_stmts grammar-token-python-grammar-async_with_stmt7676505
Ref: 25097676505
Ref: The async with statement-Footnote-17677650
Node: Type parameter lists7677692
Ref: reference/compound_stmts type-parameter-lists7677813
Ref: 256b7677813
Ref: reference/compound_stmts type-params7677813
Ref: 5ad7677813
Ref: reference/compound_stmts grammar-token-python-grammar-type_params7677980
Ref: 24fb7677980
Ref: reference/compound_stmts grammar-token-python-grammar-type_param7678062
Ref: 256c7678062
Ref: reference/compound_stmts grammar-token-python-grammar-typevar7678155
Ref: 256d7678155
Ref: reference/compound_stmts grammar-token-python-grammar-typevartuple7678258
Ref: 256e7678258
Ref: reference/compound_stmts grammar-token-python-grammar-paramspec7678335
Ref: 256f7678335
Ref: Type parameter lists-Footnote-17682715
Node: Generic functions7682757
Ref: reference/compound_stmts generic-functions7682855
Ref: 6837682855
Ref: reference/compound_stmts id177682855
Ref: 25717682855
Node: Generic classes7684661
Ref: reference/compound_stmts generic-classes7684788
Ref: 6827684788
Ref: reference/compound_stmts id187684788
Ref: 25727684788
Node: Generic type aliases7685924
Ref: reference/compound_stmts generic-type-aliases7686025
Ref: 6857686025
Ref: reference/compound_stmts id197686025
Ref: 25737686025
Node: Annotations<2>7686829
Ref: reference/compound_stmts annotations7686928
Ref: 25637686928
Ref: reference/compound_stmts id207686928
Ref: 25747686928
Ref: Annotations<2>-Footnote-17688761
Node: Top-level components7688803
Ref: reference/toplevel_components doc7688952
Ref: 25757688952
Ref: reference/toplevel_components top-level7688952
Ref: 25767688952
Ref: reference/toplevel_components top-level-components7688952
Ref: 25777688952
Ref: reference/toplevel_components translation-repo7688952
Ref: 25787688952
Node: Complete Python programs7689345
Ref: reference/toplevel_components complete-python-programs7689445
Ref: 25797689445
Ref: reference/toplevel_components programs7689445
Ref: 24357689445
Node: File input7690827
Ref: reference/toplevel_components file-input7690953
Ref: 257a7690953
Ref: reference/toplevel_components id17690953
Ref: 257b7690953
Ref: reference/toplevel_components grammar-token-python-grammar-file_input7691050
Ref: 257c7691050
Node: Interactive input7691346
Ref: reference/toplevel_components interactive7691464
Ref: 257d7691464
Ref: reference/toplevel_components interactive-input7691464
Ref: 257e7691464
Ref: reference/toplevel_components grammar-token-python-grammar-interactive_input7691579
Ref: 257f7691579
Node: Expression input7691847
Ref: reference/toplevel_components expression-input7691946
Ref: 25807691946
Ref: reference/toplevel_components id27691946
Ref: 25817691946
Ref: reference/toplevel_components grammar-token-python-grammar-eval_input7692148
Ref: 25827692148
Node: Full Grammar specification7692214
Ref: reference/grammar doc7692335
Ref: 25407692335
Ref: reference/grammar full-grammar-specification7692335
Ref: 25837692335
Ref: reference/grammar id17692335
Ref: 25847692335
Ref: reference/grammar translation-repo7692335
Ref: 25857692335
Ref: Full Grammar specification-Footnote-17771706
Node: The Python Standard Library7771778
Ref: library/index doc7771938
Ref: 25867771938
Ref: library/index library-index7771938
Ref: 1497771938
Ref: library/index the-python-standard-library7771938
Ref: 25877771938
Ref: library/index translation-repo7771938
Ref: 25887771938
Ref: The Python Standard Library-Footnote-17774754
Node: Introduction<5>7774779
Ref: library/intro doc7774887
Ref: 25897774887
Ref: library/intro introduction7774887
Ref: 258a7774887
Ref: library/intro library-intro7774887
Ref: 258b7774887
Node: Notes on availability7777567
Ref: library/intro availability7777640
Ref: 21287777640
Ref: library/intro notes-on-availability7777640
Ref: 258c7777640
Node: WebAssembly platforms7778392
Ref: library/intro wasm-availability7778496
Ref: 1b527778496
Ref: library/intro webassembly-platforms7778496
Ref: 258d7778496
Ref: library/intro mobile-availability7780980
Ref: 22457780980
Ref: WebAssembly platforms-Footnote-17781017
Ref: WebAssembly platforms-Footnote-27781050
Ref: WebAssembly platforms-Footnote-37781082
Ref: WebAssembly platforms-Footnote-47781108
Ref: WebAssembly platforms-Footnote-57781140
Ref: WebAssembly platforms-Footnote-67781166
Ref: WebAssembly platforms-Footnote-77781196
Ref: WebAssembly platforms-Footnote-87781225
Ref: WebAssembly platforms-Footnote-97781255
Node: Mobile platforms7781315
Ref: library/intro ios-availability7781419
Ref: 258e7781419
Ref: library/intro mobile-platforms7781419
Ref: 258f7781419
Ref: Mobile platforms-Footnote-17784231
Node: Funzioni Incorporate7784297
Ref: library/functions doc7784432
Ref: 25907784432
Ref: library/functions built-in-funcs7784432
Ref: 14647784432
Ref: library/functions built-in-functions7784432
Ref: 25917784432
Ref: library/functions translation-repo7784432
Ref: 25927784432
Ref: library/functions abs7787873
Ref: 20777787873
Ref: library/functions aiter7788136
Ref: 9d77788136
Ref: library/functions all7788466
Ref: 16297788466
Ref: library/functions anext7788793
Ref: 9d87788793
Ref: library/functions any7789555
Ref: 16287789555
Ref: library/functions ascii7789897
Ref: 15ed7789897
Ref: library/functions bin7790298
Ref: 14b07790298
Ref: library/functions bool7791091
Ref: 3c37791091
Ref: library/functions breakpoint7791731
Ref: 2717791731
Ref: library/functions func-bytearray7793024
Ref: 1e837793024
Ref: library/functions func-bytes7794531
Ref: 1e827794531
Ref: library/functions callable7795315
Ref: 13ce7795315
Ref: library/functions chr7795928
Ref: 19d77795928
Ref: library/functions classmethod7796388
Ref: 48f7796388
Ref: library/functions compile7798076
Ref: 4b27798076
Ref: library/functions complex7802625
Ref: 1977802625
Ref: library/functions grammar-token-float-complexvalue7804218
Ref: 25a57804218
Ref: library/functions delattr7806115
Ref: 25937806115
Ref: library/functions func-dict7806618
Ref: 25947806618
Ref: library/functions dir7807095
Ref: 8457807095
Ref: library/functions divmod7810019
Ref: b9b7810019
Ref: library/functions enumerate7810663
Ref: 16887810663
Ref: library/functions func-eval7811592
Ref: 25a97811592
Ref: library/functions eval7811592
Ref: 4a47811592
Ref: library/functions exec7814992
Ref: 4a37814992
Ref: library/functions filter7818979
Ref: a667818979
Ref: library/functions float7819791
Ref: 1967819791
Ref: library/functions grammar-token-float-sign7820754
Ref: 25a77820754
Ref: library/functions grammar-token-float-infinity7820789
Ref: 25ab7820789
Ref: library/functions grammar-token-float-nan7820833
Ref: 25ac7820833
Ref: library/functions grammar-token-float-digit7820864
Ref: 25ad7820864
Ref: library/functions grammar-token-float-digitpart7820963
Ref: 25ae7820963
Ref: library/functions grammar-token-float-number7821035
Ref: 25af7821035
Ref: library/functions grammar-token-float-exponent7821143
Ref: 25b07821143
Ref: library/functions grammar-token-float-floatnumber7821223
Ref: 25b17821223
Ref: library/functions grammar-token-float-absfloatvalue7821292
Ref: 25a87821292
Ref: library/functions grammar-token-float-floatvalue7821385
Ref: 25a67821385
Ref: library/functions format7822720
Ref: 1997822720
Ref: library/functions func-frozenset7823877
Ref: 25957823877
Ref: library/functions getattr7824377
Ref: dcc7824377
Ref: library/functions globals7825315
Ref: 1bf27825315
Ref: library/functions hasattr7825615
Ref: 6fa7825615
Ref: library/functions hash7825984
Ref: 8027825984
Ref: library/functions help7826588
Ref: ad67826588
Ref: library/functions hex7827801
Ref: 14d77827801
Ref: library/functions id7828937
Ref: 162a7828937
Ref: library/functions input7829389
Ref: 14e07829389
Ref: library/functions int7830374
Ref: 19b7830374
Ref: library/functions isinstance7833700
Ref: 2ad7833700
Ref: library/functions issubclass7834599
Ref: 9c67834599
Ref: library/functions iter7835273
Ref: 9d97835273
Ref: library/functions len7836754
Ref: 8417836754
Ref: library/functions func-list7837150
Ref: 25967837150
Ref: library/functions locals7837400
Ref: 46f7837400
Ref: library/functions map7840282
Ref: 19f7840282
Ref: library/functions max7841029
Ref: 110e7841029
Ref: library/functions func-memoryview7842459
Ref: 25977842459
Ref: library/functions min7842634
Ref: 110d7842634
Ref: library/functions next7844052
Ref: 9da7844052
Ref: library/functions object7844407
Ref: c807844407
Ref: library/functions oct7844880
Ref: 14d67844880
Ref: library/functions open7845661
Ref: 3167845661
Ref: library/functions filemodes7847234
Ref: 25b57847234
Ref: library/functions open-newline-parameter7852903
Ref: 9497852903
Ref: library/functions ord7858281
Ref: 23237858281
Ref: library/functions pow7858819
Ref: 1a47858819
Ref: library/functions print7860965
Ref: 11777860965
Ref: library/functions property7862269
Ref: 4b47862269
Ref: library/functions property getter7863948
Ref: 19c17863948
Ref: library/functions property setter7863976
Ref: 19c27863976
Ref: library/functions property deleter7864004
Ref: 19c37864004
Ref: library/functions property __name__7865274
Ref: 4b37865274
Ref: library/functions func-range7865456
Ref: 25987865456
Ref: library/functions repr7865743
Ref: 1c17865743
Ref: library/functions reversed7866832
Ref: a677866832
Ref: library/functions round7867165
Ref: 14e27867165
Ref: library/functions func-set7868608
Ref: 25997868608
Ref: library/functions setattr7869085
Ref: 259a7869085
Ref: library/functions slice7870291
Ref: 6957870291
Ref: library/functions slice start7870888
Ref: 238b7870888
Ref: library/functions slice stop7870915
Ref: 238c7870915
Ref: library/functions slice step7870941
Ref: 238d7870941
Ref: library/functions sorted7871448
Ref: dc97871448
Ref: library/functions staticmethod7873232
Ref: 4537873232
Ref: library/functions func-str7875093
Ref: 259b7875093
Ref: library/functions sum7875531
Ref: 6967875531
Ref: library/functions super7876600
Ref: 1a67876600
Ref: library/functions func-tuple7881430
Ref: 259c7881430
Ref: library/functions type7881684
Ref: f467881684
Ref: library/functions vars7883536
Ref: 1e0b7883536
Ref: library/functions zip7884531
Ref: 1a07884531
Ref: library/functions import__7888702
Ref: ad37888702
Ref: Funzioni Incorporate-Footnote-17892371
Ref: Funzioni Incorporate-Footnote-27892633
Ref: Funzioni Incorporate-Footnote-37892675
Ref: Funzioni Incorporate-Footnote-47892717
Ref: Funzioni Incorporate-Footnote-57892759
Ref: Funzioni Incorporate-Footnote-67892801
Ref: Funzioni Incorporate-Footnote-77892878
Ref: Funzioni Incorporate-Footnote-87892926
Ref: Funzioni Incorporate-Footnote-97892968
Node: Built-in Constants7893010
Ref: library/constants doc7893146
Ref: 25bf7893146
Ref: library/constants built-in-constants7893146
Ref: 25c07893146
Ref: library/constants built-in-consts7893146
Ref: 25c17893146
Ref: library/constants translation-repo7893146
Ref: 25c27893146
Ref: library/constants False7893265
Ref: d2d7893265
Ref: library/constants True7893415
Ref: e097893415
Ref: library/constants None7893562
Ref: 8867893562
Ref: library/constants NotImplemented7893860
Ref: 1a27893860
Ref: library/constants Ellipsis7895704
Ref: 23117895704
Ref: library/constants debug__7896047
Ref: 9dc7896047
Node: Constants added by the site module7896514
Ref: library/constants constants-added-by-the-site-module7896603
Ref: 25c37896603
Ref: library/constants site-consts7896603
Ref: 25c47896603
Ref: library/constants quit7896972
Ref: 25c57896972
Ref: library/constants exit7896999
Ref: 25c67896999
Ref: library/constants copyright7897561
Ref: 17707897561
Ref: library/constants credits7897581
Ref: 17717897581
Ref: library/constants license7897702
Ref: 176f7897702
Node: Tipi incorporati7897927
Ref: library/stdtypes doc7898062
Ref: 25c77898062
Ref: library/stdtypes bltin-types7898062
Ref: 25c87898062
Ref: library/stdtypes built-in-types7898062
Ref: 25c97898062
Ref: library/stdtypes translation-repo7898062
Ref: 25ca7898062
Node: Test del Valore di Verità7899848
Ref: library/stdtypes truth7899970
Ref: 18407899970
Ref: library/stdtypes truth-value-testing7899970
Ref: 25cb7899970
Ref: Test del Valore di Verità-Footnote-17901281
Node: Operazioni Booleane — and or not7901431
Ref: library/stdtypes boolean7901571
Ref: 25cc7901571
Ref: library/stdtypes boolean-operations-and-or-not7901571
Ref: 25cd7901571
Node: Confronti7902974
Ref: library/stdtypes comparisons7903123
Ref: 25ce7903123
Ref: library/stdtypes stdcomparisons7903123
Ref: 25cf7903123
Node: Tipi Numerici — int float complex7905691
Ref: library/stdtypes numeric-types-int-float-complex7905826
Ref: 25d07905826
Ref: library/stdtypes typesnumeric7905826
Ref: 1fc47905826
Ref: Tipi Numerici — int float complex-Footnote-17914504
Ref: Tipi Numerici — int float complex-Footnote-27914623
Node: Operazioni Bitwise sui Tipi Integer7914700
Ref: library/stdtypes bitstring-ops7914850
Ref: 25d27914850
Ref: library/stdtypes bitwise-operations-on-integer-types7914850
Ref: 25d37914850
Node: Metodi Aggiuntivi sui Tipi Integer7917281
Ref: library/stdtypes additional-methods-on-integer-types7917466
Ref: 25d47917466
Ref: library/stdtypes int bit_length7917686
Ref: 25d57917686
Ref: library/stdtypes int bit_count7918663
Ref: 9d17918663
Ref: library/stdtypes int to_bytes7919149
Ref: 1c1a7919149
Ref: library/stdtypes int from_bytes7921505
Ref: 1bd17921505
Ref: library/stdtypes int as_integer_ratio7923523
Ref: bc27923523
Ref: library/stdtypes int is_integer7923834
Ref: 1ad37923834
Node: Metodi aggiuntivi su Float7924020
Ref: library/stdtypes additional-methods-on-float7924199
Ref: 25d87924199
Ref: library/stdtypes float from_number7924411
Ref: 1947924411
Ref: library/stdtypes float as_integer_ratio7925067
Ref: 20eb7925067
Ref: library/stdtypes float is_integer7925367
Ref: 25d77925367
Ref: library/stdtypes float hex7926063
Ref: 20ec7926063
Ref: library/stdtypes float fromhex7926346
Ref: 25d97926346
Node: Additional Methods on Complex7928054
Ref: library/stdtypes additional-methods-on-complex7928224
Ref: 25da7928224
Ref: library/stdtypes complex from_number7928460
Ref: 1957928460
Node: Hashing dei tipi numerici7928895
Ref: library/stdtypes hashing-of-numeric-types7929030
Ref: 25dc7929030
Ref: library/stdtypes numeric-hash7929030
Ref: 25dd7929030
Ref: library/stdtypes bltin-boolean-values7933271
Ref: 25df7933271
Node: Tipo Booleano - bool7933272
Ref: library/stdtypes boolean-type-bool7933415
Ref: 25e07933415
Ref: library/stdtypes typebool7933415
Ref: 259d7933415
Node: Tipi di Iteratore7934686
Ref: library/stdtypes iterator-types7934831
Ref: 25e17934831
Ref: library/stdtypes typeiter7934831
Ref: 25b37934831
Ref: library/stdtypes container __iter__7935306
Ref: 20947935306
Ref: library/stdtypes iterator __iter__7936120
Ref: 20977936120
Ref: library/stdtypes iterator __next__7936505
Ref: 14d57936505
Node: Tipi di Generatore7937363
Ref: library/stdtypes generator-types7937435
Ref: 25e27937435
Ref: library/stdtypes id37937435
Ref: 25e37937435
Node: Tipi di Sequenza — list tuple range7937939
Ref: library/stdtypes sequence-types-list-tuple-range7938109
Ref: 25e47938109
Ref: library/stdtypes typesseq7938109
Ref: 20187938109
Node: Operazioni Comuni sulle Sequenze7938605
Ref: library/stdtypes common-sequence-operations7938747
Ref: 25e57938747
Ref: library/stdtypes typesseq-common7938747
Ref: 25e67938747
Ref: library/stdtypes list count7947205
Ref: 15cd7947205
Ref: library/stdtypes sequence count7947205
Ref: 23be7947205
Ref: library/stdtypes list index7947315
Ref: 15cc7947315
Ref: library/stdtypes sequence index7947315
Ref: 19617947315
Ref: Operazioni Comuni sulle Sequenze-Footnote-17947931
Node: Tipi di Sequenza Immutabili7948017
Ref: library/stdtypes immutable-sequence-types7948193
Ref: 25ea7948193
Ref: library/stdtypes typesseq-immutable7948193
Ref: 25eb7948193
Node: Tipi di Sequenza Mutabili7948803
Ref: library/stdtypes mutable-sequence-types7948955
Ref: 25ec7948955
Ref: library/stdtypes typesseq-mutable7948955
Ref: 259e7948955
Ref: library/stdtypes bytearray append7952449
Ref: 15ad7952449
Ref: library/stdtypes sequence append7952449
Ref: 23bc7952449
Ref: library/stdtypes bytearray clear7952612
Ref: 25ed7952612
Ref: library/stdtypes sequence clear7952612
Ref: 23bd7952612
Ref: library/stdtypes bytearray copy7952770
Ref: 25ee7952770
Ref: library/stdtypes sequence copy7952770
Ref: 25ef7952770
Ref: library/stdtypes bytearray extend7953112
Ref: 17797953112
Ref: library/stdtypes sequence extend7953112
Ref: 23bf7953112
Ref: library/stdtypes bytearray insert7953311
Ref: 25f07953311
Ref: library/stdtypes sequence insert7953311
Ref: 23c07953311
Ref: library/stdtypes bytearray pop7953492
Ref: 15ae7953492
Ref: library/stdtypes sequence pop7953492
Ref: 23c17953492
Ref: library/stdtypes bytearray remove7953674
Ref: 25f17953674
Ref: library/stdtypes sequence remove7953674
Ref: 19627953674
Ref: library/stdtypes bytearray reverse7953872
Ref: 15af7953872
Ref: library/stdtypes sequence reverse7953872
Ref: 23c27953872
Node: Liste<2>7954109
Ref: library/stdtypes lists7954239
Ref: 25f27954239
Ref: library/stdtypes typesseq-list7954239
Ref: 200c7954239
Ref: library/stdtypes list7954446
Ref: 24d7954446
Ref: library/stdtypes list sort7955786
Ref: dca7955786
Node: Tuple7962106
Ref: library/stdtypes tuples7962221
Ref: 25f67962221
Ref: library/stdtypes typesseq-tuple7962221
Ref: 25267962221
Ref: library/stdtypes tuple7962626
Ref: 6147962626
Node: Intervalli7964349
Ref: library/stdtypes ranges7964447
Ref: 25f77964447
Ref: library/stdtypes typesseq-range7964447
Ref: 25b97964447
Ref: library/stdtypes range7964655
Ref: b3f7964655
Ref: library/stdtypes range start7966818
Ref: 25f87966818
Ref: library/stdtypes range stop7966947
Ref: 25f97966947
Ref: library/stdtypes range step7967015
Ref: 25fa7967015
Ref: Intervalli-Footnote-17969192
Node: Text and Binary Sequence Type Methods Summary7969278
Ref: library/stdtypes text-and-binary-sequence-type-methods-summary7969461
Ref: 25fb7969461
Ref: library/stdtypes text-methods-summary7969461
Ref: 25fc7969461
Node: Tipo Sequenza di Testo — str7980341
Ref: library/stdtypes text-sequence-type-str7980542
Ref: 262a7980542
Ref: library/stdtypes textseq7980542
Ref: 1fc97980542
Ref: library/stdtypes str7982422
Ref: 1697982422
Node: Metodi per le Stringhe7984889
Ref: library/stdtypes id57985022
Ref: 262c7985022
Ref: library/stdtypes string-methods7985022
Ref: 1fca7985022
Ref: library/stdtypes str capitalize7985976
Ref: 261a7985976
Ref: library/stdtypes str casefold7986363
Ref: fd87986363
Ref: library/stdtypes str center7987234
Ref: 204d7987234
Ref: library/stdtypes str count7987697
Ref: 19697987697
Ref: library/stdtypes str encode7988420
Ref: ad47988420
Ref: library/stdtypes str endswith7989766
Ref: 10ce7989766
Ref: library/stdtypes str expandtabs7990550
Ref: 26237990550
Ref: library/stdtypes str find7991779
Ref: 10aa7991779
Ref: library/stdtypes str format7992563
Ref: 8347992563
Ref: library/stdtypes str format_map7994384
Ref: fd97994384
Ref: library/stdtypes str index7994925
Ref: 19a47994925
Ref: library/stdtypes str isalnum7995409
Ref: 260d7995409
Ref: library/stdtypes str isalpha7995757
Ref: 26077995757
Ref: library/stdtypes str isascii7996577
Ref: ceb7996577
Ref: library/stdtypes str isdecimal7996936
Ref: 26097996936
Ref: library/stdtypes str isdigit7997553
Ref: 260a7997553
Ref: library/stdtypes str isidentifier7998088
Ref: 1d2e7998088
Ref: library/stdtypes str islower7998694
Ref: 260f7998694
Ref: library/stdtypes str isnumeric7998956
Ref: 260c7998956
Ref: library/stdtypes str isprintable7999902
Ref: fda7999902
Ref: library/stdtypes str isspace8000924
Ref: 26158000924
Ref: library/stdtypes str istitle8001352
Ref: 26138001352
Ref: library/stdtypes str isupper8001938
Ref: 26118001938
Ref: library/stdtypes meth-str-join8002336
Ref: 26318002336
Ref: library/stdtypes str join8002336
Ref: 25e88002336
Ref: library/stdtypes str ljust8002854
Ref: 204c8002854
Ref: library/stdtypes str lower8003464
Ref: 1b5e8003464
Ref: library/stdtypes str lstrip8003802
Ref: 16b78003802
Ref: library/stdtypes str maketrans8004675
Ref: fdb8004675
Ref: library/stdtypes str partition8005508
Ref: 10ad8005508
Ref: library/stdtypes str removeprefix8005885
Ref: ace8005885
Ref: library/stdtypes str removesuffix8006314
Ref: acf8006314
Ref: library/stdtypes str replace8006772
Ref: 4b98006772
Ref: library/stdtypes str rfind8007367
Ref: 10ab8007367
Ref: library/stdtypes str rindex8007862
Ref: 145f8007862
Ref: library/stdtypes str rjust8008027
Ref: 204b8008027
Ref: library/stdtypes str rpartition8008393
Ref: 14608008393
Ref: library/stdtypes str rsplit8009105
Ref: 145d8009105
Ref: library/stdtypes str rstrip8009615
Ref: 16b88009615
Ref: library/stdtypes str split8010465
Ref: 10ac8010465
Ref: library/stdtypes str splitlines8012651
Ref: 145e8012651
Ref: library/stdtypes str startswith8015474
Ref: 10cd8015474
Ref: library/stdtypes str strip8015862
Ref: 16b68015862
Ref: library/stdtypes str swapcase8016917
Ref: 261e8016917
Ref: library/stdtypes str title8017139
Ref: 261c8017139
Ref: library/stdtypes str translate8018464
Ref: 26288018464
Ref: library/stdtypes str upper8019499
Ref: 26188019499
Ref: library/stdtypes str zfill8020008
Ref: 16b98020008
Ref: Metodi per le Stringhe-Footnote-18020575
Ref: Metodi per le Stringhe-Footnote-28020659
Ref: Metodi per le Stringhe-Footnote-38020743
Ref: Metodi per le Stringhe-Footnote-48020957
Ref: Metodi per le Stringhe-Footnote-58021171
Ref: Metodi per le Stringhe-Footnote-68021385
Ref: Metodi per le Stringhe-Footnote-78021469
Ref: Metodi per le Stringhe-Footnote-88021683
Node: Formatted String Literals f-strings8021767
Ref: library/stdtypes formatted-string-literals-f-strings8021943
Ref: 26348021943
Ref: library/stdtypes stdtypes-fstrings8021943
Ref: 22d48021943
Node: Debug specifier8023147
Ref: library/stdtypes debug-specifier8023263
Ref: 26358023263
Node: Conversion specifier8023858
Ref: library/stdtypes conversion-specifier8023999
Ref: 26368023999
Node: Format specifier8024984
Ref: library/stdtypes format-specifier8025101
Ref: 26378025101
Node: Template String Literals t-strings8025868
Ref: library/stdtypes stdtypes-tstrings8026066
Ref: 22d88026066
Ref: library/stdtypes template-string-literals-t-strings8026066
Ref: 26388026066
Node: Formattazione delle stringhe in stile printf8027940
Ref: library/stdtypes old-string-formatting8028094
Ref: 8dc8028094
Ref: library/stdtypes printf-style-string-formatting8028094
Ref: 263a8028094
Ref: Formattazione delle stringhe in stile printf-Footnote-18037904
Ref: Formattazione delle stringhe in stile printf-Footnote-28038036
Node: Tipi di sequenze binarie — bytes bytearray memoryview8038078
Ref: library/stdtypes binary-sequence-types-bytes-bytearray-memoryview8038267
Ref: 263b8038267
Ref: library/stdtypes binaryseq8038267
Ref: 25a08038267
Node: Oggetti bytes8039007
Ref: library/stdtypes bytes-objects8039138
Ref: 263c8039138
Ref: library/stdtypes typebytes8039138
Ref: 25a28039138
Ref: library/stdtypes bytes8039506
Ref: 1928039506
Ref: library/stdtypes bytes fromhex8042113
Ref: 1908042113
Ref: library/stdtypes bytes hex8042959
Ref: f678042959
Node: Oggetti Bytearray8044744
Ref: library/stdtypes bytearray-objects8044915
Ref: 263d8044915
Ref: library/stdtypes typebytearray8044915
Ref: 25a18044915
Ref: library/stdtypes bytearray8045067
Ref: 3448045067
Ref: library/stdtypes bytearray fromhex8046201
Ref: 1918046201
Ref: library/stdtypes bytearray hex8047082
Ref: f688047082
Ref: library/stdtypes bytearray resize8047647
Ref: 18948047647
Node: Operazioni su Bytes e Bytearray8049250
Ref: library/stdtypes bytes-and-bytearray-operations8049440
Ref: 263e8049440
Ref: library/stdtypes bytes-methods8049440
Ref: 259f8049440
Ref: library/stdtypes bytes count8050760
Ref: 196a8050760
Ref: library/stdtypes bytearray count8050806
Ref: 177c8050806
Ref: library/stdtypes bytes removeprefix8051462
Ref: 263f8051462
Ref: library/stdtypes bytearray removeprefix8051505
Ref: 26408051505
Ref: library/stdtypes bytes removesuffix8052145
Ref: 26418052145
Ref: library/stdtypes bytearray removesuffix8052188
Ref: 26428052188
Ref: library/stdtypes bytes decode8052859
Ref: ad58052859
Ref: library/stdtypes bytearray decode8052920
Ref: 26438052920
Ref: library/stdtypes bytes endswith8054343
Ref: 26008054343
Ref: library/stdtypes bytearray endswith8054395
Ref: 15aa8054395
Ref: library/stdtypes bytes find8054876
Ref: 1bbc8054876
Ref: library/stdtypes bytearray find8054921
Ref: 15ab8054921
Ref: library/stdtypes bytes index8055832
Ref: 25fd8055832
Ref: library/stdtypes bytearray index8055878
Ref: 177d8055878
Ref: library/stdtypes bytes join8056288
Ref: 25e98056288
Ref: library/stdtypes bytearray join8056325
Ref: 26448056325
Ref: library/stdtypes bytes maketrans8056778
Ref: 147c8056778
Ref: library/stdtypes bytearray maketrans8056827
Ref: 147d8056827
Ref: library/stdtypes bytes partition8057231
Ref: 26058057231
Ref: library/stdtypes bytearray partition8057268
Ref: 26458057268
Ref: library/stdtypes bytes replace8057809
Ref: 26018057809
Ref: library/stdtypes bytearray replace8057859
Ref: 26468057859
Ref: library/stdtypes bytes rfind8058453
Ref: 1bbd8058453
Ref: library/stdtypes bytearray rfind8058499
Ref: 15ac8058499
Ref: library/stdtypes bytes rindex8059098
Ref: 25fe8059098
Ref: library/stdtypes bytearray rindex8059145
Ref: 177e8059145
Ref: library/stdtypes bytes rpartition8059563
Ref: 26068059563
Ref: library/stdtypes bytearray rpartition8059601
Ref: 26478059601
Ref: library/stdtypes bytes startswith8060145
Ref: 25ff8060145
Ref: library/stdtypes bytearray startswith8060199
Ref: 15a98060199
Ref: library/stdtypes bytes translate8060681
Ref: 26298060681
Ref: library/stdtypes bytearray translate8060732
Ref: 15038060732
Ref: library/stdtypes bytes center8061822
Ref: 26228061822
Ref: library/stdtypes bytearray center8061873
Ref: 26488061873
Ref: library/stdtypes bytes ljust8062435
Ref: 26208062435
Ref: library/stdtypes bytearray ljust8062485
Ref: 26498062485
Ref: library/stdtypes bytes lstrip8063061
Ref: 26268063061
Ref: library/stdtypes bytearray lstrip8063102
Ref: 264a8063102
Ref: library/stdtypes bytes rjust8064258
Ref: 26218064258
Ref: library/stdtypes bytearray rjust8064308
Ref: 264b8064308
Ref: library/stdtypes bytes rsplit8064882
Ref: 26038064882
Ref: library/stdtypes bytearray rsplit8064931
Ref: 17818064931
Ref: library/stdtypes bytes rstrip8065502
Ref: 26278065502
Ref: library/stdtypes bytearray rstrip8065543
Ref: 264c8065543
Ref: library/stdtypes bytes split8066681
Ref: 26028066681
Ref: library/stdtypes bytearray split8066729
Ref: 17808066729
Ref: library/stdtypes bytes strip8068741
Ref: 26258068741
Ref: library/stdtypes bytearray strip8068781
Ref: 264d8068781
Ref: library/stdtypes bytes capitalize8069927
Ref: 261b8069927
Ref: library/stdtypes bytearray capitalize8069959
Ref: 264e8069959
Ref: library/stdtypes bytes expandtabs8070406
Ref: 26248070406
Ref: library/stdtypes bytearray expandtabs8070447
Ref: 264f8070447
Ref: library/stdtypes bytes isalnum8072005
Ref: 260e8072005
Ref: library/stdtypes bytearray isalnum8072034
Ref: 26508072034
Ref: library/stdtypes bytes isalpha8072605
Ref: 26088072605
Ref: library/stdtypes bytearray isalpha8072634
Ref: 26518072634
Ref: library/stdtypes bytes isascii8073079
Ref: 26528073079
Ref: library/stdtypes bytearray isascii8073108
Ref: 26538073108
Ref: library/stdtypes bytes isdigit8073347
Ref: 260b8073347
Ref: library/stdtypes bytearray isdigit8073376
Ref: 26548073376
Ref: library/stdtypes bytes islower8073763
Ref: 26108073763
Ref: library/stdtypes bytearray islower8073792
Ref: 26558073792
Ref: library/stdtypes bytes isspace8074336
Ref: 26168074336
Ref: library/stdtypes bytearray isspace8074365
Ref: 26568074365
Ref: library/stdtypes bytes istitle8074740
Ref: 26148074740
Ref: library/stdtypes bytearray istitle8074769
Ref: 26578074769
Ref: library/stdtypes bytes isupper8075167
Ref: 26128075167
Ref: library/stdtypes bytearray isupper8075196
Ref: 26588075196
Ref: library/stdtypes bytes lower8075756
Ref: 26178075756
Ref: library/stdtypes bytearray lower8075783
Ref: 26598075783
Ref: library/stdtypes bytes splitlines8076446
Ref: 26048076446
Ref: library/stdtypes bytearray splitlines8076492
Ref: 265a8076492
Ref: library/stdtypes bytes swapcase8077560
Ref: 261f8077560
Ref: library/stdtypes bytearray swapcase8077590
Ref: 265b8077590
Ref: library/stdtypes bytes title8078541
Ref: 261d8078541
Ref: library/stdtypes bytearray title8078568
Ref: 265c8078568
Ref: library/stdtypes bytes upper8080414
Ref: 26198080414
Ref: library/stdtypes bytearray upper8080441
Ref: 265d8080441
Ref: library/stdtypes bytes zfill8081104
Ref: 265e8081104
Ref: library/stdtypes bytearray zfill8081139
Ref: 265f8081139
Node: Formattazione Bytes stile printf8081910
Ref: library/stdtypes bytes-formatting8082095
Ref: f838082095
Ref: library/stdtypes printf-style-bytes-formatting8082095
Ref: 26608082095
Ref: Formattazione Bytes stile printf-Footnote-18092042
Ref: Formattazione Bytes stile printf-Footnote-28092174
Ref: Formattazione Bytes stile printf-Footnote-38092216
Node: Memory Views8092258
Ref: library/stdtypes memory-views8092403
Ref: 26618092403
Ref: library/stdtypes typememoryview8092403
Ref: 25b48092403
Ref: library/stdtypes memoryview8092614
Ref: 1658092614
Ref: library/stdtypes memoryview __eq__8097197
Ref: 26658097197
Ref: library/stdtypes memoryview tobytes8099534
Ref: 26668099534
Ref: library/stdtypes memoryview hex8100842
Ref: f698100842
Ref: library/stdtypes memoryview tolist8101481
Ref: 26628101481
Ref: library/stdtypes memoryview toreadonly8102142
Ref: 26678102142
Ref: library/stdtypes memoryview release8102868
Ref: 13c68102868
Ref: library/stdtypes memoryview cast8104484
Ref: 26688104484
Ref: library/stdtypes memoryview count8108076
Ref: 18e08108076
Ref: library/stdtypes memoryview index8108215
Ref: 18df8108215
Ref: library/stdtypes memoryview obj8108612
Ref: 266a8108612
Ref: library/stdtypes memoryview nbytes8108886
Ref: 266b8108886
Ref: library/stdtypes memoryview readonly8110162
Ref: 266c8110162
Ref: library/stdtypes memoryview format8110266
Ref: 26648110266
Ref: library/stdtypes memoryview itemsize8110902
Ref: 26638110902
Ref: library/stdtypes memoryview ndim8111330
Ref: 266d8111330
Ref: library/stdtypes memoryview shape8111485
Ref: 266e8111485
Ref: library/stdtypes memoryview strides8111805
Ref: 266f8111805
Ref: library/stdtypes memoryview suboffsets8112163
Ref: 26708112163
Ref: library/stdtypes memoryview c_contiguous8112305
Ref: 26718112305
Ref: library/stdtypes memoryview f_contiguous8112475
Ref: 26728112475
Ref: library/stdtypes memoryview contiguous8112651
Ref: 26738112651
Ref: Memory Views-Footnote-18112853
Node: Tipi di Insiemi — set frozenset8112895
Ref: library/stdtypes set-types-set-frozenset8113078
Ref: 26748113078
Ref: library/stdtypes types-set8113078
Ref: 201b8113078
Ref: library/stdtypes set8114749
Ref: 1848114749
Ref: library/stdtypes frozenset8114782
Ref: 7f38114782
Ref: library/stdtypes frozenset isdisjoint8115882
Ref: 26768115882
Ref: library/stdtypes set isdisjoint8115926
Ref: 26778115926
Ref: library/stdtypes frozenset issubset8116142
Ref: 26788116142
Ref: library/stdtypes set issubset8116184
Ref: 26798116184
Ref: library/stdtypes frozenset issuperset8116454
Ref: 267a8116454
Ref: library/stdtypes set issuperset8116498
Ref: 1b6d8116498
Ref: library/stdtypes frozenset union8116784
Ref: 168a8116784
Ref: library/stdtypes set union8116822
Ref: 267b8116822
Ref: library/stdtypes frozenset intersection8116974
Ref: 168b8116974
Ref: library/stdtypes set intersection8117019
Ref: 1b6c8117019
Ref: library/stdtypes frozenset difference8117186
Ref: 267c8117186
Ref: library/stdtypes set difference8117229
Ref: 267d8117229
Ref: library/stdtypes frozenset symmetric_difference8117396
Ref: 267e8117396
Ref: library/stdtypes set symmetric_difference8117450
Ref: 267f8117450
Ref: library/stdtypes frozenset copy8117635
Ref: 26808117635
Ref: library/stdtypes set copy8117665
Ref: 26818117665
Ref: library/stdtypes set update8119947
Ref: 26828119947
Ref: library/stdtypes set intersection_update8120086
Ref: 168c8120086
Ref: library/stdtypes set difference_update8120270
Ref: 26838120270
Ref: library/stdtypes set symmetric_difference_update8120424
Ref: 168d8120424
Ref: library/stdtypes set add8120631
Ref: 23268120631
Ref: library/stdtypes set remove8120714
Ref: 26758120714
Ref: library/stdtypes set discard8120878
Ref: 26848120878
Ref: library/stdtypes set pop8120978
Ref: 26858120978
Ref: library/stdtypes set clear8121129
Ref: 26868121129
Node: Tipi di Mapping — dict8121656
Ref: library/stdtypes mapping-types-dict8121811
Ref: 26878121811
Ref: library/stdtypes typesmapping8121811
Ref: cbf8121811
Ref: library/stdtypes dict8122669
Ref: 1838122669
Ref: library/stdtypes dict clear8128518
Ref: 17be8128518
Ref: library/stdtypes dict copy8128596
Ref: dcb8128596
Ref: library/stdtypes dict fromkeys8128684
Ref: 24e8128684
Ref: library/stdtypes dict get8129260
Ref: 201e8129260
Ref: library/stdtypes dict items8129552
Ref: 9d48129552
Ref: library/stdtypes dict keys8129753
Ref: 9d28129753
Ref: library/stdtypes dict pop8129913
Ref: 5e68129913
Ref: library/stdtypes dict popitem8130227
Ref: 172d8130227
Ref: library/stdtypes dict setdefault8131089
Ref: 127b8131089
Ref: library/stdtypes dict update8131348
Ref: 166c8131348
Ref: library/stdtypes dict values8132098
Ref: 9d38132098
Node: Oggetti vista del dizionario8133891
Ref: library/stdtypes dict-views8133980
Ref: 25f48133980
Ref: library/stdtypes dictionary-view-objects8133980
Ref: 26888133980
Node: Tipi di gestori di contesti8137937
Ref: library/stdtypes context-manager-types8138111
Ref: 268a8138111
Ref: library/stdtypes typecontextmanager8138111
Ref: 23f08138111
Ref: library/stdtypes contextmanager __enter__8138566
Ref: 268b8138566
Ref: library/stdtypes contextmanager __exit__8139686
Ref: 268c8139686
Node: Tipi di annotazione di tipo — Alias generico Union8142389
Ref: library/stdtypes type-annotation-types-generic-alias-union8142559
Ref: 268d8142559
Node: Tipo Generic Alias8142838
Ref: library/stdtypes generic-alias-type8142965
Ref: 268e8142965
Ref: library/stdtypes types-genericalias8142965
Ref: 8c28142965
Node: Classi Generiche Standard8148079
Ref: library/stdtypes standard-generic-classes8148211
Ref: 26908148211
Node: Attributi Speciali per oggetti GenericAlias8150620
Ref: library/stdtypes special-attributes-of-genericalias-objects8150752
Ref: 269d8150752
Ref: library/stdtypes genericalias __origin__8150946
Ref: 269e8150946
Ref: library/stdtypes genericalias __args__8151117
Ref: 268f8151117
Ref: library/stdtypes genericalias __parameters__8151426
Ref: 269f8151426
Ref: library/stdtypes genericalias __unpacked__8152022
Ref: 26a08152022
Ref: Attributi Speciali per oggetti GenericAlias-Footnote-18152934
Ref: Attributi Speciali per oggetti GenericAlias-Footnote-28152976
Node: Tipo Unione8153018
Ref: library/stdtypes types-union8153145
Ref: 9c78153145
Ref: library/stdtypes union-type8153145
Ref: 26a18153145
Ref: Tipo Unione-Footnote-18156976
Node: Altri Tipi Integrati8157018
Ref: library/stdtypes other-built-in-types8157179
Ref: 26a28157179
Ref: library/stdtypes typesother8157179
Ref: 26a38157179
Node: Moduli<2>8157575
Ref: library/stdtypes modules8157676
Ref: 26a48157676
Ref: library/stdtypes typesmodules8157676
Ref: 26a58157676
Node: Classi e Istanze di Classe8158914
Ref: library/stdtypes classes-and-class-instances8159032
Ref: 26a68159032
Ref: library/stdtypes typesobjects8159032
Ref: 26a78159032
Node: Funzioni8159195
Ref: library/stdtypes functions8159310
Ref: 26a88159310
Ref: library/stdtypes typesfunctions8159310
Ref: 26a98159310
Node: Metodi8159807
Ref: library/stdtypes methods8159910
Ref: 26aa8159910
Ref: library/stdtypes typesmethods8159910
Ref: 26ab8159910
Node: Oggetti Codice8161895
Ref: library/stdtypes bltin-code-objects8162002
Ref: 26ac8162002
Ref: library/stdtypes code-objects8162002
Ref: 26ad8162002
Node: Oggetti Tipo8162924
Ref: library/stdtypes bltin-type-objects8163041
Ref: 25be8163041
Ref: library/stdtypes type-objects8163041
Ref: 26ae8163041
Node: L’Oggetto Null8163410
Ref: library/stdtypes bltin-null-object8163533
Ref: 26af8163533
Ref: library/stdtypes the-null-object8163533
Ref: 26b08163533
Node: L’Oggetto Ellipsis8163864
Ref: library/stdtypes bltin-ellipsis-object8164001
Ref: 1fe68164001
Ref: library/stdtypes the-ellipsis-object8164001
Ref: 26b18164001
Ref: L’Oggetto Ellipsis-Footnote-18165201
Node: L’Oggetto NotImplemented8165286
Ref: library/stdtypes bltin-notimplemented-object8165422
Ref: 26b48165422
Ref: library/stdtypes the-notimplemented-object8165422
Ref: 26b58165422
Node: Oggetti Interni8165841
Ref: library/stdtypes internal-objects8165948
Ref: 26b68165948
Ref: library/stdtypes typesinternal8165948
Ref: 26b78165948
Node: Attributi Speciali8166161
Ref: library/stdtypes special-attributes8166337
Ref: 26b88166337
Ref: library/stdtypes specialattrs8166337
Ref: 26b98166337
Ref: library/stdtypes definition __name__8166584
Ref: 12688166584
Ref: library/stdtypes definition __qualname__8166709
Ref: 12678166709
Ref: library/stdtypes definition __module__8166889
Ref: 26ba8166889
Ref: library/stdtypes definition __doc__8166998
Ref: b238166998
Ref: library/stdtypes definition __type_params__8167121
Ref: 25708167121
Node: Limitazione della lunghezza di conversione delle stringhe di interi8167379
Ref: library/stdtypes int-max-str-digits8167526
Ref: 80c8167526
Ref: library/stdtypes integer-string-conversion-length-limitation8167526
Ref: 26bb8167526
Ref: Limitazione della lunghezza di conversione delle stringhe di interi-Footnote-18170506
Node: API influenzate8170562
Ref: library/stdtypes affected-apis8170715
Ref: 26bc8170715
Node: Configurazione del limite8171682
Ref: library/stdtypes configuring-the-limit8171870
Ref: 26bd8171870
Node: Configurazione consigliata8174683
Ref: library/stdtypes recommended-configuration8174847
Ref: 26c08174847
Node: Built-in Exceptions8175821
Ref: library/exceptions doc8175962
Ref: 26c18175962
Ref: library/exceptions bltin-exceptions8175962
Ref: 1c0f8175962
Ref: library/exceptions built-in-exceptions8175962
Ref: 26c28175962
Ref: library/exceptions translation-repo8175962
Ref: 26c38175962
Node: Exception context8177699
Ref: library/exceptions exception-context8177816
Ref: 26c48177816
Ref: library/exceptions BaseException __context__8177977
Ref: 14cf8177977
Ref: library/exceptions BaseException __cause__8178018
Ref: 14d08178018
Ref: library/exceptions BaseException __suppress_context__8178057
Ref: 24f08178057
Node: Inheriting from built-in exceptions8179750
Ref: library/exceptions inheriting-from-built-in-exceptions8179888
Ref: 26c58179888
Ref: Inheriting from built-in exceptions-Footnote-18180784
Node: Base classes8180857
Ref: library/exceptions base-classes8180997
Ref: 26c68180997
Ref: library/exceptions BaseException8181116
Ref: 7d88181116
Ref: library/exceptions BaseException args8181501
Ref: 78e8181501
Ref: library/exceptions BaseException with_traceback8181869
Ref: 24ef8181869
Ref: library/exceptions BaseException __traceback__8182769
Ref: 14ce8182769
Ref: library/exceptions BaseException add_note8182971
Ref: 7d78182971
Ref: library/exceptions BaseException __notes__8183256
Ref: 26c78183256
Ref: library/exceptions Exception8183502
Ref: bcf8183502
Ref: library/exceptions ArithmeticError8183686
Ref: 26c88183686
Ref: library/exceptions BufferError8183914
Ref: 177f8183914
Ref: library/exceptions LookupError8184025
Ref: 26338184025
Ref: Base classes-Footnote-18184327
Node: Concrete exceptions8184369
Ref: library/exceptions concrete-exceptions8184482
Ref: 26ca8184482
Ref: library/exceptions AssertionError8184605
Ref: 8b98184605
Ref: library/exceptions AttributeError8184693
Ref: 5f08184693
Ref: library/exceptions AttributeError name8185061
Ref: 26cb8185061
Ref: library/exceptions AttributeError obj8185159
Ref: 26cc8185159
Ref: library/exceptions EOFError8185351
Ref: 14e18185351
Ref: library/exceptions FloatingPointError8185629
Ref: 26c98185629
Ref: library/exceptions GeneratorExit8185690
Ref: 15cf8185690
Ref: library/exceptions ImportError8186013
Ref: 65b8186013
Ref: library/exceptions ImportError name8186333
Ref: 26cd8186333
Ref: library/exceptions ImportError path8186428
Ref: 26ce8186428
Ref: library/exceptions ModuleNotFoundError8186619
Ref: d3f8186619
Ref: library/exceptions IndexError8186883
Ref: 173c8186883
Ref: library/exceptions KeyError8187110
Ref: 5e78187110
Ref: library/exceptions KeyboardInterrupt8187227
Ref: bc78187227
Ref: library/exceptions MemoryError8188099
Ref: 17868188099
Ref: library/exceptions NameError8188680
Ref: 4528188680
Ref: library/exceptions NameError name8188970
Ref: 26d08188970
Ref: library/exceptions NotImplementedError8189147
Ref: 36b8189147
Ref: library/exceptions OSError8190026
Ref: 2c08190026
Ref: library/exceptions OSError errno8191058
Ref: 179b8191058
Ref: library/exceptions OSError winerror8191150
Ref: 26d28191150
Ref: library/exceptions OSError strerror8191729
Ref: 26d38191729
Ref: library/exceptions OSError filename8191965
Ref: 26d48191965
Ref: library/exceptions OSError filename28191994
Ref: 26d58191994
Ref: library/exceptions OverflowError8193023
Ref: a838193023
Ref: library/exceptions PythonFinalizationError8193516
Ref: 4798193516
Ref: library/exceptions RecursionError8194266
Ref: f6a8194266
Ref: library/exceptions ReferenceError8194590
Ref: 17148194590
Ref: library/exceptions RuntimeError8194916
Ref: 2448194916
Ref: library/exceptions StopIteration8195118
Ref: df78195118
Ref: library/exceptions StopIteration value8195340
Ref: 23fa8195340
Ref: library/exceptions StopAsyncIteration8196517
Ref: 1df78196517
Ref: library/exceptions SyntaxError8196711
Ref: 18e8196711
Ref: library/exceptions SyntaxError filename8197233
Ref: 26d68197233
Ref: library/exceptions SyntaxError lineno8197325
Ref: 26d78197325
Ref: library/exceptions SyntaxError offset8197499
Ref: 26d88197499
Ref: library/exceptions SyntaxError text8197685
Ref: 26d98197685
Ref: library/exceptions SyntaxError end_lineno8197766
Ref: 26da8197766
Ref: library/exceptions SyntaxError end_offset8197958
Ref: 26db8197958
Ref: library/exceptions IndentationError8198595
Ref: 9ad8198595
Ref: library/exceptions TabError8198748
Ref: 7668198748
Ref: library/exceptions SystemError8198909
Ref: 7968198909
Ref: library/exceptions SystemExit8199819
Ref: f3e8199819
Ref: library/exceptions SystemExit code8201115
Ref: 26dd8201115
Ref: library/exceptions TypeError8201257
Ref: 1988201257
Ref: library/exceptions UnboundLocalError8202086
Ref: 173d8202086
Ref: library/exceptions UnicodeError8202304
Ref: 4628202304
Ref: library/exceptions UnicodeError encoding8202665
Ref: 26de8202665
Ref: library/exceptions UnicodeError reason8202754
Ref: 26df8202754
Ref: library/exceptions UnicodeError object8202839
Ref: 18e48202839
Ref: library/exceptions UnicodeError start8202935
Ref: 18a88202935
Ref: library/exceptions UnicodeError end8203183
Ref: 18a98203183
Ref: library/exceptions UnicodeEncodeError8203435
Ref: 8888203435
Ref: library/exceptions UnicodeDecodeError8203587
Ref: c0a8203587
Ref: library/exceptions UnicodeTranslateError8203739
Ref: 18e58203739
Ref: library/exceptions ValueError8203897
Ref: 2ec8203897
Ref: library/exceptions ZeroDivisionError8204150
Ref: b418204150
Ref: library/exceptions EnvironmentError8204507
Ref: 12568204507
Ref: library/exceptions IOError8204540
Ref: 12558204540
Ref: library/exceptions WindowsError8204564
Ref: 12578204564
Ref: Concrete exceptions-Footnote-18204690
Ref: Concrete exceptions-Footnote-28204732
Node: OS exceptions8204774
Ref: library/exceptions os-exceptions8204843
Ref: 26d18204843
Ref: library/exceptions BlockingIOError8205004
Ref: 2358205004
Ref: library/exceptions BlockingIOError characters_written8205390
Ref: 26e48205390
Ref: library/exceptions ChildProcessError8205642
Ref: 125a8205642
Ref: library/exceptions ConnectionError8205787
Ref: 100d8205787
Ref: library/exceptions BrokenPipeError8206039
Ref: 125e8206039
Ref: library/exceptions ConnectionAbortedError8206352
Ref: 125f8206352
Ref: library/exceptions ConnectionRefusedError8206561
Ref: 12608206561
Ref: library/exceptions ConnectionResetError8206770
Ref: 12618206770
Ref: library/exceptions FileExistsError8206965
Ref: 12228206965
Ref: library/exceptions FileNotFoundError8207127
Ref: 2648207127
Ref: library/exceptions InterruptedError8207285
Ref: f8a8207285
Ref: library/exceptions IsADirectoryError8207696
Ref: 125b8207696
Ref: library/exceptions NotADirectoryError8207887
Ref: 125c8207887
Ref: library/exceptions PermissionError8208259
Ref: f408208259
Ref: library/exceptions ProcessLookupError8208642
Ref: 125d8208642
Ref: library/exceptions TimeoutError8208780
Ref: a388208780
Ref: OS exceptions-Footnote-18209129
Ref: OS exceptions-Footnote-28209171
Node: Warnings8209213
Ref: library/exceptions warning-categories-as-exceptions8209330
Ref: 26f28209330
Ref: library/exceptions warnings8209330
Ref: 26f38209330
Ref: library/exceptions Warning8209491
Ref: 26f58209491
Ref: library/exceptions UserWarning8209556
Ref: 26f68209556
Ref: library/exceptions DeprecationWarning8209638
Ref: 1a38209638
Ref: library/exceptions PendingDeprecationWarning8210030
Ref: ac88210030
Ref: library/exceptions SyntaxWarning8210602
Ref: 1ae8210602
Ref: library/exceptions RuntimeWarning8210837
Ref: 4d88210837
Ref: library/exceptions FutureWarning8210930
Ref: 6598210930
Ref: library/exceptions ImportWarning8211117
Ref: 71f8211117
Ref: library/exceptions UnicodeWarning8211341
Ref: 162b8211341
Ref: library/exceptions EncodingWarning8211422
Ref: 21178211422
Ref: library/exceptions BytesWarning8211594
Ref: e1e8211594
Ref: library/exceptions ResourceWarning8211713
Ref: 54d8211713
Ref: Warnings-Footnote-18211987
Ref: Warnings-Footnote-28212029
Ref: Warnings-Footnote-38212071
Node: Exception groups8212113
Ref: library/exceptions exception-groups8212230
Ref: 26f78212230
Ref: library/exceptions lib-exception-groups8212230
Ref: 26f88212230
Ref: library/exceptions ExceptionGroup8212613
Ref: 4d38212613
Ref: library/exceptions BaseExceptionGroup8212656
Ref: 5668212656
Ref: library/exceptions BaseExceptionGroup message8213699
Ref: 26f98213699
Ref: library/exceptions BaseExceptionGroup exceptions8213824
Ref: 26fa8213824
Ref: library/exceptions BaseExceptionGroup subgroup8213988
Ref: 1a208213988
Ref: library/exceptions BaseExceptionGroup split8215334
Ref: 18c08215334
Ref: library/exceptions BaseExceptionGroup derive8215569
Ref: 1a1f8215569
Node: Exception hierarchy8218619
Ref: library/exceptions exception-hierarchy8218719
Ref: 26fb8218719
Ref: library/text stringservices8221596
Ref: 262b8221596
Node: Text Processing Services8221596
Ref: library/text doc8221741
Ref: 26fc8221741
Ref: library/text text-processing-services8221741
Ref: 26fd8221741
Ref: library/text textservices8221741
Ref: 262e8221741
Ref: library/text translation-repo8221741
Ref: 26fe8221741
Node: string — Common string operations8222657
Ref: library/string doc8222821
Ref: 27008222821
Ref: library/string module-string8222821
Ref: d88222821
Ref: library/string string-common-string-operations8222821
Ref: 27018222821
Ref: string — Common string operations-Footnote-18223329
Node: String constants8223405
Ref: library/string string-constants8223526
Ref: 27028223526
Ref: library/string string ascii_letters8223620
Ref: 14cb8223620
Ref: library/string string ascii_lowercase8223819
Ref: 27038223819
Ref: library/string string ascii_uppercase8223979
Ref: 27048223979
Ref: library/string string digits8224139
Ref: 27058224139
Ref: library/string string hexdigits8224201
Ref: 27068224201
Ref: library/string string octdigits8224278
Ref: 27078224278
Ref: library/string string punctuation8224341
Ref: 27088224341
Ref: library/string string printable8224516
Ref: 189f8224516
Ref: library/string string whitespace8224977
Ref: 27098224977
Ref: String constants-Footnote-18225219
Node: Custom String Formatting8225265
Ref: library/string custom-string-formatting8225415
Ref: 270a8225415
Ref: library/string string-formatting8225415
Ref: 262d8225415
Ref: library/string string Formatter8225863
Ref: 10bf8225863
Ref: library/string string Formatter format8225966
Ref: dfc8225966
Ref: library/string string Formatter vformat8226332
Ref: 270b8226332
Ref: library/string string Formatter parse8227044
Ref: 270c8227044
Ref: library/string string Formatter get_field8227948
Ref: 270d8227948
Ref: library/string string Formatter get_value8228593
Ref: 270e8228593
Ref: library/string string Formatter check_unused_args8229830
Ref: 270f8229830
Ref: library/string string Formatter format_field8230434
Ref: 27108230434
Ref: library/string string Formatter convert_field8230660
Ref: 27118230660
Ref: Custom String Formatting-Footnote-18231035
Ref: Custom String Formatting-Footnote-28231077
Node: Format String Syntax8231119
Ref: library/string format-string-syntax8231279
Ref: 27128231279
Ref: library/string formatstrings8231279
Ref: 15a38231279
Ref: library/string grammar-token-format-string-replacement_field8232140
Ref: 27138232140
Ref: library/string grammar-token-format-string-field_name8232259
Ref: 27148232259
Ref: library/string grammar-token-format-string-arg_name8232377
Ref: 27178232377
Ref: library/string grammar-token-format-string-attribute_name8232449
Ref: 27188232449
Ref: library/string grammar-token-format-string-element_index8232497
Ref: 27198232497
Ref: library/string grammar-token-format-string-index_string8232569
Ref: 271a8232569
Ref: library/string grammar-token-format-string-conversion8232629
Ref: 27158232629
Ref: library/string grammar-token-format-string-format_spec8232669
Ref: 27168232669
Ref: library/string formatstrings-conversion8235016
Ref: 271c8235016
Node: Format Specification Mini-Language8236785
Ref: library/string format-specification-mini-language8236900
Ref: 271e8236900
Ref: library/string formatspec8236900
Ref: 4fa8236900
Ref: library/string grammar-token-format-spec-format_spec8237803
Ref: 271b8237803
Ref: library/string grammar-token-format-spec-options8237909
Ref: 271f8237909
Ref: library/string grammar-token-format-spec-fill8238013
Ref: 27228238013
Ref: library/string grammar-token-format-spec-align8238059
Ref: 27238238059
Ref: library/string grammar-token-format-spec-sign8238111
Ref: 27248238111
Ref: library/string grammar-token-format-spec-width_and_precision8238157
Ref: 27208238157
Ref: library/string grammar-token-format-spec-width_with_grouping8238260
Ref: 27258238260
Ref: library/string grammar-token-format-spec-precision_with_grouping8238334
Ref: 27268238334
Ref: library/string grammar-token-format-spec-width8238444
Ref: 27278238444
Ref: library/string grammar-token-format-spec-precision8238494
Ref: 27298238494
Ref: library/string grammar-token-format-spec-grouping8238544
Ref: 27288238544
Ref: library/string grammar-token-format-spec-type8238584
Ref: 27218238584
Ref: Format Specification Mini-Language-Footnote-18253590
Ref: Format Specification Mini-Language-Footnote-28253632
Ref: Format Specification Mini-Language-Footnote-38253674
Node: Format examples8253716
Ref: library/string format-examples8253831
Ref: 272b8253831
Ref: library/string formatexamples8253831
Ref: 271d8253831
Node: Template strings $-strings8258791
Ref: library/string template-strings-pep2928258943
Ref: 272c8258943
Ref: library/string template-strings-strings8258943
Ref: 272d8258943
Ref: library/string string Template8260924
Ref: 8988260924
Ref: library/string string Template substitute8261045
Ref: 20bf8261045
Ref: library/string string Template safe_substitute8261530
Ref: 20c08261530
Ref: library/string string Template is_valid8262483
Ref: 8978262483
Ref: library/string string Template get_identifiers8262713
Ref: 8968262713
Ref: library/string string Template template8263010
Ref: 272f8263010
Ref: Template strings $-strings-Footnote-18266936
Ref: Template strings $-strings-Footnote-28266978
Node: Helper functions8267030
Ref: library/string helper-functions8267153
Ref: 27308267153
Ref: library/string string capwords8267204
Ref: 26328267204
Node: string templatelib — Support for template string literals8267691
Ref: library/string templatelib doc8267900
Ref: 27318267900
Ref: library/string templatelib module-string templatelib8267900
Ref: d98267900
Ref: library/string templatelib string-templatelib-support-for-template-string-literals8267900
Ref: 27328267900
Ref: library/string templatelib translation-repo8267900
Ref: 27338267900
Ref: string templatelib — Support for template string literals-Footnote-18268404
Ref: string templatelib — Support for template string literals-Footnote-28268483
Node: Template strings8268525
Ref: library/string templatelib id18268651
Ref: 27348268651
Ref: library/string templatelib template-strings8268651
Ref: 272e8268651
Node: Types8269301
Ref: library/string templatelib types8269455
Ref: 27358269455
Ref: library/string templatelib string templatelib Template8269484
Ref: 16a8269484
Ref: library/string templatelib string templatelib Template strings8270994
Ref: 27368270994
Ref: library/string templatelib string templatelib Template interpolations8271958
Ref: 27378271958
Ref: library/string templatelib string templatelib Template values8272538
Ref: 27388272538
Ref: library/string templatelib string templatelib Template __new__8273062
Ref: 27398273062
Ref: library/string templatelib string templatelib Interpolation8276908
Ref: 16b8276908
Ref: library/string templatelib string templatelib Interpolation value8277761
Ref: 273a8277761
Ref: library/string templatelib string templatelib Interpolation expression8277933
Ref: 273b8277933
Ref: library/string templatelib string templatelib Interpolation conversion8278784
Ref: 26398278784
Ref: library/string templatelib string templatelib Interpolation format_spec8279547
Ref: 273d8279547
Ref: library/string templatelib string templatelib Interpolation __new__8280456
Ref: 273e8280456
Node: Helper functions<2>8281222
Ref: library/string templatelib helper-functions8281351
Ref: 273f8281351
Ref: library/string templatelib string templatelib convert8281402
Ref: 273c8281402
Node: re — Regular expression operations8281999
Ref: library/re doc8282213
Ref: 27408282213
Ref: library/re module-re8282213
Ref: be8282213
Ref: library/re re-regular-expression-operations8282213
Ref: 27418282213
Ref: library/re translation-repo8282213
Ref: 27428282213
Ref: re — Regular expression operations-Footnote-18284786
Ref: re — Regular expression operations-Footnote-28284846
Node: Regular Expression Syntax8284886
Ref: library/re re-syntax8285008
Ref: 92f8285008
Ref: library/re regular-expression-syntax8285008
Ref: 27438285008
Ref: library/re re-conditional-expression8305894
Ref: 1b108305894
Ref: library/re re-special-sequences8306589
Ref: 27508306589
Ref: Regular Expression Syntax-Footnote-18312956
Ref: Regular Expression Syntax-Footnote-28312998
Node: Module Contents8313070
Ref: library/re contents-of-module-re8313227
Ref: 274f8313227
Ref: library/re module-contents8313227
Ref: 27518313227
Node: Flags8313578
Ref: library/re flags8313653
Ref: 27528313653
Ref: library/re re RegexFlag8313818
Ref: 8408313818
Ref: library/re re A8313986
Ref: 27488313986
Ref: library/re re ASCII8314001
Ref: 83f8314001
Ref: library/re re DEBUG8314674
Ref: 27538314674
Ref: library/re re I8314789
Ref: 27498314789
Ref: library/re re IGNORECASE8314804
Ref: 1a7e8314804
Ref: library/re re L8315792
Ref: 274a8315792
Ref: library/re re LOCALE8315807
Ref: d658315807
Ref: library/re re M8316805
Ref: 274b8316805
Ref: library/re re MULTILINE8316820
Ref: 27478316820
Ref: library/re re NOFLAG8317410
Ref: 27548317410
Ref: library/re re S8317801
Ref: 274c8317801
Ref: library/re re DOTALL8317816
Ref: 27468317816
Ref: library/re re U8318057
Ref: 274d8318057
Ref: library/re re UNICODE8318072
Ref: d668318072
Ref: library/re re X8318368
Ref: 274e8318368
Ref: library/re re VERBOSE8318383
Ref: 27558318383
Node: Functions8319455
Ref: library/re functions8319552
Ref: 27568319552
Ref: library/re re compile8319589
Ref: dd08319589
Ref: library/re re search8320727
Ref: 14348320727
Ref: library/re re match8321317
Ref: 14358321317
Ref: library/re re fullmatch8322161
Ref: 11878322161
Ref: library/re re split8322683
Ref: 5a28322683
Ref: library/re re findall8324972
Ref: 122c8324972
Ref: library/re re finditer8326206
Ref: 17018326206
Ref: library/re re sub8326846
Ref: 5a38326846
Ref: library/re re subn8330645
Ref: 5a48330645
Ref: library/re re escape8331027
Ref: e058331027
Ref: library/re re purge8332530
Ref: 275a8332530
Node: Exceptions<2>8332599
Ref: library/re exceptions8332682
Ref: 275b8332682
Ref: library/re re PatternError8332721
Ref: 5478332721
Ref: library/re re PatternError msg8333174
Ref: 104d8333174
Ref: library/re re PatternError pattern8333241
Ref: 104e8333241
Ref: library/re re PatternError pos8333313
Ref: 104f8333313
Ref: library/re re PatternError lineno8333428
Ref: 10508333428
Ref: library/re re PatternError colno8333520
Ref: 10518333520
Node: Regular Expression Objects8333830
Ref: library/re re-objects8333975
Ref: 11898333975
Ref: library/re regular-expression-objects8333975
Ref: 275c8333975
Ref: library/re re Pattern8334046
Ref: 1b4f8334046
Ref: library/re re Pattern search8334322
Ref: 27588334322
Ref: library/re re Pattern match8335779
Ref: 27578335779
Ref: library/re re Pattern fullmatch8336630
Ref: 11888336630
Ref: library/re re Pattern split8337422
Ref: 275d8337422
Ref: library/re re Pattern findall8337556
Ref: 275e8337556
Ref: library/re re Pattern finditer8337819
Ref: 275f8337819
Ref: library/re re Pattern sub8338084
Ref: 27608338084
Ref: library/re re Pattern subn8338217
Ref: 27618338217
Ref: library/re re Pattern flags8338352
Ref: 27628338352
Ref: library/re re Pattern groups8338625
Ref: 27638338625
Ref: library/re re Pattern groupindex8338709
Ref: 27648338709
Ref: library/re re Pattern pattern8338923
Ref: 27658338923
Node: Match Objects8339187
Ref: library/re id38339344
Ref: 27668339344
Ref: library/re match-objects8339344
Ref: 118a8339344
Ref: library/re re Match8339696
Ref: ec58339696
Ref: library/re re Match expand8339958
Ref: 27678339958
Ref: library/re re Match group8340559
Ref: 122d8340559
Ref: library/re re Match __getitem__8342829
Ref: 27688342829
Ref: library/re re Match groups8343531
Ref: 122e8343531
Ref: library/re re Match groupdict8344377
Ref: 27698344377
Ref: library/re re Match start8344844
Ref: 276a8344844
Ref: library/re re Match end8344878
Ref: 276b8344878
Ref: library/re re Match span8345926
Ref: 276c8345926
Ref: library/re re Match pos8346179
Ref: 276d8346179
Ref: library/re re Match endpos8346440
Ref: 276e8346440
Ref: library/re re Match lastindex8346695
Ref: 276f8346695
Ref: library/re re Match lastgroup8347094
Ref: 27708347094
Ref: library/re re Match re8347267
Ref: 27718347267
Ref: library/re re Match string8347435
Ref: 27728347435
Node: Regular Expression Examples8347678
Ref: library/re re-examples8347800
Ref: 14658347800
Ref: library/re regular-expression-examples8347800
Ref: 27738347800
Node: Checking for a Pair8348144
Ref: library/re checking-for-a-pair8348252
Ref: 27748348252
Node: Simulating scanf8350335
Ref: library/re simulating-scanf8350467
Ref: 27758350467
Node: search vs match8352537
Ref: library/re id48352668
Ref: 27768352668
Ref: library/re search-vs-match8352668
Ref: 27598352668
Node: Making a Phonebook8354123
Ref: library/re making-a-phonebook8354250
Ref: 27778354250
Node: Text Munging8356449
Ref: library/re text-munging8356580
Ref: 27788356580
Node: Finding all Adverbs8357411
Ref: library/re finding-all-adverbs8357563
Ref: 27798357563
Node: Finding all Adverbs and their Positions8358023
Ref: library/re finding-all-adverbs-and-their-positions8358182
Ref: 277a8358182
Node: Raw String Notation8358886
Ref: library/re raw-string-notation8359045
Ref: 277b8359045
Node: Writing a Tokenizer8359972
Ref: library/re writing-a-tokenizer8360083
Ref: 277c8360083
Ref: library/re frie098363454
Ref: 27448363454
Ref: Writing a Tokenizer-Footnote-18363734
Node: difflib — Helpers for computing deltas8363789
Ref: library/difflib doc8363982
Ref: 277d8363982
Ref: library/difflib difflib-helpers-for-computing-deltas8363982
Ref: 277e8363982
Ref: library/difflib module-difflib8363982
Ref: 3b8363982
Ref: library/difflib translation-repo8363982
Ref: 277f8363982
Ref: library/difflib difflib Differ8366487
Ref: 27808366487
Ref: library/difflib difflib HtmlDiff8367665
Ref: 2018367665
Ref: library/difflib difflib HtmlDiff __init__8368036
Ref: 27818368036
Ref: library/difflib difflib HtmlDiff make_file8368847
Ref: ff28368847
Ref: library/difflib difflib HtmlDiff make_table8370531
Ref: 27838370531
Ref: library/difflib difflib context_diff8370992
Ref: 196e8370992
Ref: library/difflib difflib get_close_matches8373038
Ref: 27868373038
Ref: library/difflib difflib ndiff8374200
Ref: 27828374200
Ref: library/difflib difflib restore8375764
Ref: 27888375764
Ref: library/difflib difflib unified_diff8376507
Ref: 196d8376507
Ref: library/difflib difflib diff_bytes8378432
Ref: ff38378432
Ref: library/difflib difflib IS_LINE_JUNK8379326
Ref: 2d78379326
Ref: library/difflib difflib IS_CHARACTER_JUNK8379628
Ref: 27878379628
Ref: difflib — Helpers for computing deltas-Footnote-18380302
Ref: difflib — Helpers for computing deltas-Footnote-28380369
Node: SequenceMatcher Objects8380449
Ref: library/difflib sequence-matcher8380582
Ref: 278a8380582
Ref: library/difflib sequencematcher-objects8380582
Ref: 278b8380582
Ref: library/difflib difflib SequenceMatcher8380709
Ref: 121b8380709
Ref: library/difflib difflib SequenceMatcher set_seqs8382249
Ref: 278c8382249
Ref: library/difflib difflib SequenceMatcher set_seq18382668
Ref: 278e8382668
Ref: library/difflib difflib SequenceMatcher set_seq28382811
Ref: 278d8382811
Ref: library/difflib difflib SequenceMatcher find_longest_match8382954
Ref: 1d338382954
Ref: library/difflib difflib SequenceMatcher get_matching_blocks8385116
Ref: 278f8385116
Ref: library/difflib difflib SequenceMatcher get_opcodes8386033
Ref: 27908386033
Ref: library/difflib difflib SequenceMatcher get_grouped_opcodes8388020
Ref: 27918388020
Ref: library/difflib difflib SequenceMatcher ratio8388453
Ref: 27928388453
Ref: library/difflib difflib SequenceMatcher quick_ratio8389476
Ref: 27938389476
Ref: library/difflib difflib SequenceMatcher real_quick_ratio8389596
Ref: 27948389596
Node: SequenceMatcher Examples8390128
Ref: library/difflib id18390284
Ref: 27958390284
Ref: library/difflib sequencematcher-examples8390284
Ref: 27968390284
Ref: SequenceMatcher Examples-Footnote-18392028
Node: Differ Objects8392105
Ref: library/difflib differ-objects8392252
Ref: 27978392252
Ref: library/difflib id28392252
Ref: 27988392252
Ref: library/difflib difflib Differ compare8393659
Ref: 27898393659
Node: Differ Example8394183
Ref: library/difflib differ-example8394341
Ref: 27998394341
Ref: library/difflib differ-examples8394341
Ref: 279a8394341
Node: A command-line interface to difflib8396604
Ref: library/difflib a-command-line-interface-to-difflib8396761
Ref: 279b8396761
Ref: library/difflib difflib-interface8396761
Ref: 27858396761
Node: ndiff example8399400
Ref: library/difflib ndiff-example8399534
Ref: 279c8399534
Node: textwrap — Text wrapping and filling8403184
Ref: library/textwrap doc8403373
Ref: 279d8403373
Ref: library/textwrap module-textwrap8403373
Ref: f28403373
Ref: library/textwrap textwrap-text-wrapping-and-filling8403373
Ref: 279e8403373
Ref: library/textwrap translation-repo8403373
Ref: 279f8403373
Ref: library/textwrap textwrap wrap8403906
Ref: 16ce8403906
Ref: library/textwrap textwrap fill8404644
Ref: 16cd8404644
Ref: library/textwrap textwrap shorten8405276
Ref: 11d28405276
Ref: library/textwrap textwrap dedent8406521
Ref: 1a98406521
Ref: library/textwrap textwrap indent8407699
Ref: 57d8407699
Ref: library/textwrap textwrap TextWrapper8409040
Ref: 11cf8409040
Ref: library/textwrap textwrap TextWrapper width8409719
Ref: 27a68409719
Ref: library/textwrap textwrap TextWrapper expand_tabs8410042
Ref: 27a28410042
Ref: library/textwrap textwrap TextWrapper tabsize8410252
Ref: 27a18410252
Ref: library/textwrap textwrap TextWrapper replace_whitespace8410542
Ref: 27a48410542
Ref: library/textwrap textwrap TextWrapper drop_whitespace8411505
Ref: 27a38411505
Ref: library/textwrap textwrap TextWrapper initial_indent8411919
Ref: 27a78411919
Ref: library/textwrap textwrap TextWrapper subsequent_indent8412154
Ref: 27a88412154
Ref: library/textwrap textwrap TextWrapper fix_sentence_endings8412381
Ref: 27a98412381
Ref: library/textwrap textwrap TextWrapper break_long_words8413584
Ref: 27a58413584
Ref: library/textwrap textwrap TextWrapper break_on_hyphens8414074
Ref: 27aa8414074
Ref: library/textwrap textwrap TextWrapper max_lines8414606
Ref: 11d08414606
Ref: library/textwrap textwrap TextWrapper placeholder8414853
Ref: 11d18414853
Ref: library/textwrap textwrap TextWrapper wrap8415170
Ref: 27a08415170
Ref: library/textwrap textwrap TextWrapper fill8415593
Ref: 27ab8415593
Ref: textwrap — Text wrapping and filling-Footnote-18415780
Node: unicodedata — Unicode Database8415848
Ref: library/unicodedata doc8416039
Ref: 27ac8416039
Ref: library/unicodedata module-unicodedata8416039
Ref: 10b8416039
Ref: library/unicodedata translation-repo8416039
Ref: 27ad8416039
Ref: library/unicodedata unicodedata-unicode-database8416039
Ref: 27ae8416039
Ref: library/unicodedata unicodedata lookup8416679
Ref: 127a8416679
Ref: library/unicodedata unicodedata name8417313
Ref: 27af8417313
Ref: library/unicodedata unicodedata decimal8417708
Ref: 27b08417708
Ref: library/unicodedata unicodedata digit8418124
Ref: 27b18418124
Ref: library/unicodedata unicodedata numeric8418437
Ref: 146a8418437
Ref: library/unicodedata unicodedata category8418738
Ref: 27b28418738
Ref: library/unicodedata unicodedata bidirectional8419138
Ref: 27b38419138
Ref: library/unicodedata unicodedata combining8419597
Ref: 27b48419597
Ref: library/unicodedata unicodedata east_asian_width8419902
Ref: 27b58419902
Ref: library/unicodedata unicodedata mirrored8420126
Ref: 27b68420126
Ref: library/unicodedata unicodedata decomposition8420454
Ref: 27b78420454
Ref: library/unicodedata unicodedata normalize8420752
Ref: 8e58420752
Ref: library/unicodedata unicodedata is_normalized8422624
Ref: c3e8422624
Ref: library/unicodedata unicodedata unidata_version8422933
Ref: 27b88422933
Ref: library/unicodedata unicodedata ucd_3_2_08423035
Ref: 163b8423035
Ref: unicodedata — Unicode Database-Footnote-18423334
Ref: unicodedata — Unicode Database-Footnote-28423384
Ref: unicodedata — Unicode Database-Footnote-38423430
Ref: unicodedata — Unicode Database-Footnote-48423502
Ref: unicodedata — Unicode Database-Footnote-58423577
Ref: unicodedata — Unicode Database-Footnote-68423660
Ref: unicodedata — Unicode Database-Footnote-78423737
Ref: unicodedata — Unicode Database-Footnote-88423829
Node: stringprep — Internet String Preparation8423887
Ref: library/stringprep doc8424075
Ref: 27b98424075
Ref: library/stringprep module-stringprep8424075
Ref: da8424075
Ref: library/stringprep stringprep-internet-string-preparation8424075
Ref: 27ba8424075
Ref: library/stringprep translation-repo8424075
Ref: 27bb8424075
Ref: library/stringprep stringprep in_table_a18425984
Ref: 27bc8425984
Ref: library/stringprep stringprep in_table_b18426121
Ref: 27bd8426121
Ref: library/stringprep stringprep map_table_b28426247
Ref: 27be8426247
Ref: library/stringprep stringprep map_table_b38426404
Ref: 27bf8426404
Ref: library/stringprep stringprep in_table_c118426573
Ref: 27c08426573
Ref: library/stringprep stringprep in_table_c128426693
Ref: 27c18426693
Ref: library/stringprep stringprep in_table_c11_c128426822
Ref: 27c28426822
Ref: library/stringprep stringprep in_table_c218426969
Ref: 27c38426969
Ref: library/stringprep stringprep in_table_c228427096
Ref: 27c48427096
Ref: library/stringprep stringprep in_table_c21_c228427227
Ref: 27c58427227
Ref: library/stringprep stringprep in_table_c38427376
Ref: 27c68427376
Ref: library/stringprep stringprep in_table_c48427482
Ref: 27c78427482
Ref: library/stringprep stringprep in_table_c58427607
Ref: 27c88427607
Ref: library/stringprep stringprep in_table_c68427717
Ref: 27c98427717
Ref: library/stringprep stringprep in_table_c78427845
Ref: 27ca8427845
Ref: library/stringprep stringprep in_table_c88427987
Ref: 27cb8427987
Ref: library/stringprep stringprep in_table_c98428130
Ref: 27cc8428130
Ref: library/stringprep stringprep in_table_d18428243
Ref: 27cd8428243
Ref: library/stringprep stringprep in_table_d28428397
Ref: 27ce8428397
Ref: stringprep — Internet String Preparation-Footnote-18428577
Ref: stringprep — Internet String Preparation-Footnote-28428647
Ref: stringprep — Internet String Preparation-Footnote-38428706
Node: readline — GNU readline interface8428765
Ref: library/readline doc8428973
Ref: 27cf8428973
Ref: library/readline module-readline8428973
Ref: bf8428973
Ref: library/readline readline-gnu-readline-interface8428973
Ref: 27d08428973
Ref: library/readline translation-repo8428973
Ref: 27d18428973
Ref: library/readline readline backend8431309
Ref: 1a0f8431309
Ref: readline — GNU readline interface-Footnote-18431633
Node: Init file8431718
Ref: library/readline init-file8431819
Ref: 27d28431819
Ref: library/readline readline parse_and_bind8431929
Ref: 27d38431929
Ref: library/readline readline read_init_file8432110
Ref: 17c28432110
Node: Line buffer8432581
Ref: library/readline line-buffer8432703
Ref: 27d48432703
Ref: library/readline readline get_line_buffer8432797
Ref: 27d58432797
Ref: library/readline readline insert_text8432948
Ref: 27d68432948
Ref: library/readline readline redisplay8433158
Ref: 16cc8433158
Node: History file8433363
Ref: library/readline history-file8433488
Ref: 27d78433488
Ref: library/readline readline read_history_file8433583
Ref: 17c38433583
Ref: library/readline readline write_history_file8434006
Ref: 17c48434006
Ref: library/readline readline append_history_file8434453
Ref: 10538434453
Ref: library/readline readline get_history_length8435048
Ref: 27d88435048
Ref: library/readline readline set_history_length8435093
Ref: 190e8435093
Node: History list8435456
Ref: library/readline history-list8435583
Ref: 27d98435583
Ref: library/readline readline clear_history8435685
Ref: 27da8435685
Ref: library/readline readline get_current_history_length8435933
Ref: 16cb8435933
Ref: library/readline readline get_history_item8436198
Ref: 16ca8436198
Ref: library/readline readline remove_history_item8436408
Ref: 27db8436408
Ref: library/readline readline replace_history_item8436628
Ref: 27dc8436628
Ref: library/readline readline add_history8436859
Ref: 27dd8436859
Ref: library/readline readline set_auto_history8437043
Ref: ec78437043
Node: Startup hooks8437525
Ref: library/readline startup-hooks8437650
Ref: 27de8437650
Ref: library/readline readline set_startup_hook8437695
Ref: 27df8437695
Ref: library/readline readline set_pre_input_hook8438099
Ref: 27e08438099
Node: Completion8438671
Ref: library/readline completion8438791
Ref: 27e18438791
Ref: library/readline readline-completion8438791
Ref: 27e28438791
Ref: library/readline readline set_completer8439277
Ref: 27e38439277
Ref: library/readline readline get_completer8440068
Ref: 27e48440068
Ref: library/readline readline get_completion_type8440201
Ref: 27e58440201
Ref: library/readline readline get_begidx8440401
Ref: 1c8c8440401
Ref: library/readline readline get_endidx8440438
Ref: 1c8d8440438
Ref: library/readline readline set_completer_delims8440883
Ref: 1a128440883
Ref: library/readline readline get_completer_delims8440936
Ref: 27e68440936
Ref: library/readline readline set_completion_display_matches_hook8441257
Ref: 27e78441257
Node: Example8441846
Ref: library/readline example8441944
Ref: 27e88441944
Ref: library/readline readline-example8441944
Ref: 27e98441944
Node: rlcompleter — Completion function for GNU readline8444791
Ref: library/rlcompleter doc8444948
Ref: 27eb8444948
Ref: library/rlcompleter module-rlcompleter8444948
Ref: c28444948
Ref: library/rlcompleter rlcompleter-completion-function-for-gnu-readline8444948
Ref: 27ec8444948
Ref: library/rlcompleter translation-repo8444948
Ref: 27ed8444948
Ref: library/rlcompleter completer-objects8446437
Ref: 27ef8446437
Ref: library/rlcompleter rlcompleter Completer8446437
Ref: 1d138446437
Ref: library/rlcompleter rlcompleter Completer complete8446523
Ref: 27ee8446523
Ref: rlcompleter — Completion function for GNU readline-Footnote-18447562
Node: Binary Data Services8447633
Ref: library/binary doc8447769
Ref: 27f08447769
Ref: library/binary binary-data-services8447769
Ref: 27f18447769
Ref: library/binary binaryservices8447769
Ref: 26ff8447769
Ref: library/binary translation-repo8447769
Ref: 27f28447769
Node: struct — Interpret bytes as packed binary data8448538
Ref: library/struct doc8448694
Ref: 27f38448694
Ref: library/struct struct-interpret-bytes-as-packed-binary-data8448694
Ref: 27f48448694
Ref: library/struct module-struct8448811
Ref: db8448811
Ref: struct — Interpret bytes as packed binary data-Footnote-18450581
Node: Functions and Exceptions8450647
Ref: library/struct functions-and-exceptions8450779
Ref: 27f78450779
Ref: library/struct struct error8450905
Ref: 152b8450905
Ref: library/struct struct pack8451031
Ref: 147e8451031
Ref: library/struct struct pack_into8451273
Ref: 27f88451273
Ref: library/struct struct unpack8451572
Ref: 18428451572
Ref: library/struct struct unpack_from8451939
Ref: 27f98451939
Ref: library/struct struct iter_unpack8452335
Ref: 11c18452335
Ref: library/struct struct calcsize8452857
Ref: 1d918452857
Node: Format Strings8453056
Ref: library/struct format-strings8453209
Ref: 27fa8453209
Ref: library/struct struct-format-strings8453209
Ref: 27f58453209
Node: Byte Order Size and Alignment8453847
Ref: library/struct byte-order-size-and-alignment8453953
Ref: 27fc8453953
Ref: library/struct struct-alignment8453953
Ref: 27f68453953
Ref: Byte Order Size and Alignment-Footnote-18457669
Node: Format Characters8457723
Ref: library/struct format-characters8457849
Ref: 27fb8457849
Ref: library/struct id18457849
Ref: 27fe8457849
Ref: Format Characters-Footnote-18470575
Ref: Format Characters-Footnote-28470636
Node: Examples<2>8470712
Ref: library/struct examples8470800
Ref: 27ff8470800
Ref: library/struct struct-examples8470800
Ref: 27fd8470800
Node: Applications8473312
Ref: library/struct applications8473451
Ref: 28008473451
Ref: library/struct id28473451
Ref: 28018473451
Node: Native Formats8473952
Ref: library/struct native-formats8474040
Ref: 28048474040
Ref: library/struct struct-native-formats8474040
Ref: 28028474040
Node: Standard Formats8475188
Ref: library/struct standard-formats8475276
Ref: 28058475276
Ref: library/struct struct-standard-formats8475276
Ref: 28038475276
Node: Classes<2>8476719
Ref: library/struct classes8476835
Ref: 28068476835
Ref: library/struct struct-objects8476835
Ref: 28078476835
Ref: library/struct struct Struct8476931
Ref: 175f8476931
Ref: library/struct struct Struct pack8477628
Ref: 28088477628
Ref: library/struct struct Struct pack_into8477810
Ref: 280a8477810
Ref: library/struct struct Struct unpack8477968
Ref: 280b8477968
Ref: library/struct struct Struct unpack_from8478168
Ref: 280c8478168
Ref: library/struct struct Struct iter_unpack8478426
Ref: 11c28478426
Ref: library/struct struct Struct format8478680
Ref: e028478680
Ref: library/struct struct Struct size8478900
Ref: 28098478900
Node: codecs — Codec registry and base classes8479240
Ref: library/codecs doc8479396
Ref: 280d8479396
Ref: library/codecs codecs-codec-registry-and-base-classes8479396
Ref: 280e8479396
Ref: library/codecs module-codecs8479396
Ref: 1c8479396
Ref: library/codecs translation-repo8479396
Ref: 280f8479396
Ref: library/codecs codecs encode8480288
Ref: 11068480288
Ref: library/codecs codecs decode8480783
Ref: 11078480783
Ref: library/codecs codecs charmap_build8481278
Ref: 28118481278
Ref: library/codecs codecs lookup8481771
Ref: b5e8481771
Ref: library/codecs codecs CodecInfo8482272
Ref: 1a548482272
Ref: library/codecs codecs CodecInfo name8482569
Ref: 28128482569
Ref: library/codecs codecs CodecInfo encode8482632
Ref: 28138482632
Ref: library/codecs codecs CodecInfo decode8482659
Ref: 28148482659
Ref: library/codecs codecs CodecInfo incrementalencoder8483037
Ref: 28188483037
Ref: library/codecs codecs CodecInfo incrementaldecoder8483076
Ref: 28198483076
Ref: library/codecs codecs CodecInfo streamwriter8483415
Ref: 281c8483415
Ref: library/codecs codecs CodecInfo streamreader8483448
Ref: 281d8483448
Ref: library/codecs codecs getencoder8483901
Ref: 28208483901
Ref: library/codecs codecs getdecoder8484113
Ref: 28218484113
Ref: library/codecs codecs getincrementalencoder8484325
Ref: 28228484325
Ref: library/codecs codecs getincrementaldecoder8484631
Ref: 28238484631
Ref: library/codecs codecs getreader8484937
Ref: 28248484937
Ref: library/codecs codecs getwriter8485183
Ref: 28258485183
Ref: library/codecs codecs register8485512
Ref: 28268485512
Ref: library/codecs codecs unregister8485995
Ref: 9eb8485995
Ref: library/codecs codecs open8486496
Ref: 3158486496
Ref: library/codecs codecs EncodedFile8487984
Ref: 28288487984
Ref: library/codecs codecs iterencode8488841
Ref: 28298488841
Ref: library/codecs codecs iterdecode8489426
Ref: 282a8489426
Ref: library/codecs codecs readbuffer_encode8490085
Ref: 282b8490085
Ref: library/codecs codecs BOM8490586
Ref: 282c8490586
Ref: library/codecs codecs BOM_BE8490607
Ref: 282d8490607
Ref: library/codecs codecs BOM_LE8490631
Ref: 282e8490631
Ref: library/codecs codecs BOM_UTF88490655
Ref: 282f8490655
Ref: library/codecs codecs BOM_UTF168490681
Ref: 28308490681
Ref: library/codecs codecs BOM_UTF16_BE8490708
Ref: 28318490708
Ref: library/codecs codecs BOM_UTF16_LE8490738
Ref: 28328490738
Ref: library/codecs codecs BOM_UTF328490768
Ref: 28338490768
Ref: library/codecs codecs BOM_UTF32_BE8490795
Ref: 28348490795
Ref: library/codecs codecs BOM_UTF32_LE8490825
Ref: 28358490825
Ref: codecs — Codec registry and base classes-Footnote-18492008
Node: Codec Base Classes8492074
Ref: library/codecs codec-base-classes8492201
Ref: 28108492201
Ref: library/codecs id18492201
Ref: 28368492201
Ref: library/codecs surrogateescape8492794
Ref: 28378492794
Node: Error Handlers8492931
Ref: library/codecs error-handlers8493040
Ref: 1b578493040
Ref: library/codecs id28493040
Ref: 28388493040
Ref: library/codecs codecs register_error8497969
Ref: 16a28497969
Ref: library/codecs codecs lookup_error8499514
Ref: 16a38499514
Ref: library/codecs codecs strict_errors8499812
Ref: 28398499812
Ref: library/codecs codecs ignore_errors8499984
Ref: 283a8499984
Ref: library/codecs codecs replace_errors8500180
Ref: 18aa8500180
Ref: library/codecs codecs backslashreplace_errors8500430
Ref: 18ab8500430
Ref: library/codecs codecs xmlcharrefreplace_errors8500897
Ref: 18ac8500897
Ref: library/codecs codecs namereplace_errors8501261
Ref: 283b8501261
Ref: Error Handlers-Footnote-18501824
Node: Stateless Encoding and Decoding8501866
Ref: library/codecs codec-objects8502017
Ref: 28178502017
Ref: library/codecs stateless-encoding-and-decoding8502017
Ref: 283c8502017
Ref: library/codecs codecs Codec8502235
Ref: 283d8502235
Ref: library/codecs codecs Codec encode8502261
Ref: 28158502261
Ref: library/codecs codecs Codec decode8503081
Ref: 28168503081
Node: Incremental Encoding and Decoding8504111
Ref: library/codecs incremental-encoding-and-decoding8504276
Ref: 283e8504276
Node: IncrementalEncoder Objects8505116
Ref: library/codecs incremental-encoder-objects8505247
Ref: 28418505247
Ref: library/codecs incrementalencoder-objects8505247
Ref: 28428505247
Ref: library/codecs codecs IncrementalEncoder8505546
Ref: 281a8505546
Ref: library/codecs codecs IncrementalEncoder encode8506332
Ref: 283f8506332
Ref: library/codecs codecs IncrementalEncoder reset8506630
Ref: 28438506630
Ref: library/codecs codecs IncrementalEncoder getstate8506899
Ref: 28448506899
Ref: library/codecs codecs IncrementalEncoder setstate8507312
Ref: 28458507312
Node: IncrementalDecoder Objects8507479
Ref: library/codecs incremental-decoder-objects8507610
Ref: 28468507610
Ref: library/codecs incrementaldecoder-objects8507610
Ref: 28478507610
Ref: library/codecs codecs IncrementalDecoder8507909
Ref: 281b8507909
Ref: library/codecs codecs IncrementalDecoder decode8508695
Ref: 28408508695
Ref: library/codecs codecs IncrementalDecoder reset8509329
Ref: 28488509329
Ref: library/codecs codecs IncrementalDecoder getstate8509407
Ref: 28498509407
Ref: library/codecs codecs IncrementalDecoder setstate8510354
Ref: 284a8510354
Node: Stream Encoding and Decoding8510520
Ref: library/codecs stream-encoding-and-decoding8510645
Ref: 284b8510645
Node: StreamWriter Objects8511072
Ref: library/codecs stream-writer-objects8511186
Ref: 284c8511186
Ref: library/codecs streamwriter-objects8511186
Ref: 284d8511186
Ref: library/codecs codecs StreamWriter8511448
Ref: 281e8511448
Ref: library/codecs codecs StreamWriter write8512406
Ref: 284e8512406
Ref: library/codecs codecs StreamWriter writelines8512504
Ref: 284f8512504
Ref: library/codecs codecs StreamWriter reset8512810
Ref: 28508512810
Node: StreamReader Objects8513279
Ref: library/codecs stream-reader-objects8513428
Ref: 28518513428
Ref: library/codecs streamreader-objects8513428
Ref: 28528513428
Ref: library/codecs codecs StreamReader8513690
Ref: 281f8513690
Ref: library/codecs codecs StreamReader read8514762
Ref: 28538514762
Ref: library/codecs codecs StreamReader readline8516020
Ref: 28548516020
Ref: library/codecs codecs StreamReader readlines8516371
Ref: 28558516371
Ref: library/codecs codecs StreamReader reset8516823
Ref: 28568516823
Node: StreamReaderWriter Objects8517226
Ref: library/codecs stream-reader-writer8517376
Ref: 28578517376
Ref: library/codecs streamreaderwriter-objects8517376
Ref: 28588517376
Ref: library/codecs codecs StreamReaderWriter8517711
Ref: 28278517711
Node: StreamRecoder Objects8518367
Ref: library/codecs stream-recoder-objects8518488
Ref: 28598518488
Ref: library/codecs streamrecoder-objects8518488
Ref: 285a8518488
Ref: library/codecs codecs StreamRecoder8518838
Ref: 1dbc8518838
Node: Encodings and Unicode8519993
Ref: library/codecs encodings-and-unicode8520147
Ref: 285b8520147
Ref: library/codecs encodings-overview8520147
Ref: 285c8520147
Ref: Encodings and Unicode-Footnote-18527071
Node: Standard Encodings8527113
Ref: library/codecs id38527274
Ref: 285d8527274
Ref: library/codecs standard-encodings8527274
Ref: fba8527274
Ref: Standard Encodings-Footnote-18549865
Node: Python Specific Encodings8549943
Ref: library/codecs python-specific-encodings8550114
Ref: 285e8550114
Node: Text Encodings8550733
Ref: library/codecs text-encodings8550835
Ref: 285f8550835
Ref: Text Encodings-Footnote-18554383
Ref: Text Encodings-Footnote-28554442
Node: Binary Transforms8554501
Ref: library/codecs binary-transforms8554638
Ref: 11088554638
Ref: library/codecs id48554638
Ref: 28608554638
Ref: Binary Transforms-Footnote-18558334
Node: Standalone Codec Functions8558475
Ref: library/codecs id68558613
Ref: 28668558613
Ref: library/codecs standalone-codec-functions8558613
Ref: 28678558613
Ref: library/codecs codecs codecs escape_encode8559027
Ref: 28688559027
Ref: library/codecs codecs codecs escape_decode8559399
Ref: 28698559399
Node: Text Transforms8559722
Ref: library/codecs id78559834
Ref: 286a8559834
Ref: library/codecs text-transforms8559834
Ref: 11098559834
Node: encodings — Encodings package8560585
Ref: library/codecs encodings-encodings-package8560803
Ref: 286b8560803
Ref: library/codecs module-encodings8560803
Ref: 558560803
Ref: library/codecs encodings normalize_encoding8560941
Ref: 9ff8560941
Ref: library/codecs encodings search_function8561518
Ref: 286c8561518
Ref: library/codecs encodings win32_code_page_search_function8562213
Ref: 286d8562213
Ref: library/codecs encodings CodecRegistryError8562595
Ref: 286e8562595
Node: encodings idna — Internationalized Domain Names in Applications8562694
Ref: library/codecs encodings-idna-internationalized-domain-names-in-applications8562927
Ref: 286f8562927
Ref: library/codecs module-encodings idna8562927
Ref: 568562927
Ref: library/codecs encodings idna nameprep8565542
Ref: 28708565542
Ref: library/codecs encodings idna ToASCII8565730
Ref: 28718565730
Ref: library/codecs encodings idna ToUnicode8565890
Ref: 28728565890
Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-18566037
Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-28566096
Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-38566155
Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-48566214
Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-58566273
Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-68566312
Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-78566383
Ref: encodings idna — Internationalized Domain Names in Applications-Footnote-88566442
Node: encodings mbcs — Windows ANSI codepage8566501
Ref: library/codecs encodings-mbcs-windows-ansi-codepage8566757
Ref: 28738566757
Ref: library/codecs module-encodings mbcs8566757
Ref: 578566757
Node: encodings utf_8_sig — UTF-8 codec with BOM signature8567160
Ref: library/codecs encodings-utf-8-sig-utf-8-codec-with-bom-signature8567342
Ref: 28748567342
Ref: library/codecs module-encodings utf_8_sig8567342
Ref: 588567342
Node: Data Types8567787
Ref: library/datatypes doc8567931
Ref: 28758567931
Ref: library/datatypes data-types8567931
Ref: 28768567931
Ref: library/datatypes datatypes8567931
Ref: 28778567931
Ref: library/datatypes translation-repo8567931
Ref: 28788567931
Node: datetime — Basic date and time types8569310
Ref: library/datetime doc8569439
Ref: 28798569439
Ref: library/datetime datetime-basic-date-and-time-types8569439
Ref: 287a8569439
Ref: library/datetime module-datetime8569439
Ref: 348569439
Ref: datetime — Basic date and time types-Footnote-18570760
Ref: datetime — Basic date and time types-Footnote-28570828
Ref: datetime — Basic date and time types-Footnote-38570879
Node: Aware and Naive Objects8570922
Ref: library/datetime aware-and-naive-objects8571038
Ref: 287c8571038
Ref: library/datetime datetime-naive-aware8571038
Ref: 287d8571038
Ref: Aware and Naive Objects-Footnote-18572956
Node: Constants8573013
Ref: library/datetime constants8573153
Ref: 287e8573153
Ref: library/datetime datetime MINYEAR8573250
Ref: 287f8573250
Ref: library/datetime datetime MAXYEAR8573404
Ref: 28808573404
Ref: library/datetime datetime UTC8573560
Ref: 7148573560
Node: Available Types8573696
Ref: library/datetime available-types8573830
Ref: 28818573830
Node: Common Properties8575596
Ref: library/datetime common-properties8575716
Ref: 28928575716
Node: Determining if an Object is Aware or Naive8576138
Ref: library/datetime determining-if-an-object-is-aware-or-naive8576258
Ref: 28938576258
Node: timedelta Objects8577009
Ref: library/datetime datetime-timedelta8577146
Ref: 28948577146
Ref: library/datetime timedelta-objects8577146
Ref: 28958577146
Ref: library/datetime datetime timedelta8577341
Ref: bc58577341
Ref: library/datetime datetime timedelta min8580072
Ref: 28968580072
Ref: library/datetime datetime timedelta max8580190
Ref: 28978580190
Ref: library/datetime datetime timedelta resolution8580372
Ref: 28988580372
Ref: library/datetime datetime timedelta days8580743
Ref: 28998580743
Ref: library/datetime datetime timedelta seconds8580828
Ref: 289a8580828
Ref: library/datetime datetime timedelta microseconds8581357
Ref: 289b8581357
Ref: library/datetime datetime timedelta total_seconds8587286
Ref: 150d8587286
Node: Examples of usage timedelta8587810
Ref: library/datetime examples-of-usage-timedelta8587891
Ref: 289c8587891
Node: date Objects8588832
Ref: library/datetime date-objects8588970
Ref: 289d8588970
Ref: library/datetime datetime-date8588970
Ref: 289e8588970
Ref: library/datetime datetime date8589292
Ref: 1fa8589292
Ref: library/datetime datetime date today8589712
Ref: 16d18589712
Ref: library/datetime datetime date fromtimestamp8589855
Ref: dcf8589855
Ref: library/datetime datetime date fromordinal8590796
Ref: dce8590796
Ref: library/datetime datetime date fromisoformat8591133
Ref: 8298591133
Ref: library/datetime datetime date fromisocalendar8592047
Ref: be18592047
Ref: library/datetime datetime date strptime8592321
Ref: 1f98592321
Ref: library/datetime datetime date min8593754
Ref: 289f8593754
Ref: library/datetime datetime date max8593845
Ref: 28a08593845
Ref: library/datetime datetime date resolution8593936
Ref: 28a18593936
Ref: library/datetime datetime date year8594103
Ref: 28828594103
Ref: library/datetime datetime date month8594200
Ref: 28838594200
Ref: library/datetime datetime date day8594261
Ref: 28848594261
Ref: library/datetime datetime date replace8597099
Ref: 19e18597099
Ref: library/datetime datetime date timetuple8597555
Ref: 28a28597555
Ref: library/datetime datetime date toordinal8598044
Ref: 28a38598044
Ref: library/datetime datetime date weekday8598270
Ref: 28a48598270
Ref: library/datetime datetime date isoweekday8598495
Ref: 28a58598495
Ref: library/datetime datetime date isocalendar8598754
Ref: af38598754
Ref: library/datetime datetime date isoformat8599834
Ref: 28a68599834
Ref: library/datetime datetime date __str__8600060
Ref: 28a78600060
Ref: library/datetime datetime date ctime8600166
Ref: 28a88600166
Ref: library/datetime datetime date strftime8600640
Ref: e918600640
Ref: library/datetime datetime date __format__8600941
Ref: 28aa8600941
Ref: date Objects-Footnote-18601392
Ref: date Objects-Footnote-28601699
Node: Examples of Usage date8601915
Ref: library/datetime examples-of-usage-date8601986
Ref: 28ab8601986
Node: datetime Objects8603887
Ref: library/datetime datetime-datetime8604020
Ref: 28ac8604020
Ref: library/datetime datetime-objects8604020
Ref: 28ad8604020
Ref: library/datetime datetime datetime8604469
Ref: 4e38604469
Ref: library/datetime datetime datetime today8605339
Ref: 28ae8605339
Ref: library/datetime datetime datetime now8605704
Ref: 7128605704
Ref: library/datetime datetime datetime utcnow8606532
Ref: 3518606532
Ref: library/datetime datetime datetime fromtimestamp8607380
Ref: 7138607380
Ref: library/datetime datetime datetime utcfromtimestamp8609105
Ref: 3528609105
Ref: library/datetime datetime datetime fromordinal8610898
Ref: 28af8610898
Ref: library/datetime datetime datetime combine8611303
Ref: e928611303
Ref: library/datetime datetime datetime fromisoformat8612116
Ref: 82b8612116
Ref: library/datetime datetime datetime fromisocalendar8614221
Ref: be28614221
Ref: library/datetime datetime datetime strptime8614601
Ref: 19388614601
Ref: library/datetime datetime datetime min8616064
Ref: 1b4d8616064
Ref: library/datetime datetime datetime max8616196
Ref: 28b08616196
Ref: library/datetime datetime datetime resolution8616348
Ref: 28b18616348
Ref: library/datetime datetime datetime year8616543
Ref: 288a8616543
Ref: library/datetime datetime datetime month8616644
Ref: 288b8616644
Ref: library/datetime datetime datetime day8616709
Ref: 288c8616709
Ref: library/datetime datetime datetime hour8616820
Ref: 288d8616820
Ref: library/datetime datetime datetime minute8616876
Ref: 288e8616876
Ref: library/datetime datetime datetime second8616934
Ref: 288f8616934
Ref: library/datetime datetime datetime microsecond8616992
Ref: 28908616992
Ref: library/datetime datetime datetime tzinfo8617060
Ref: 28918617060
Ref: library/datetime datetime datetime fold8617221
Ref: e538617221
Ref: library/datetime datetime datetime date8622248
Ref: 28b28622248
Ref: library/datetime datetime datetime time8622346
Ref: 28b38622346
Ref: library/datetime datetime datetime timetz8622658
Ref: 28b48622658
Ref: library/datetime datetime datetime replace8622952
Ref: 16d28622952
Ref: library/datetime datetime datetime astimezone8623611
Ref: bc68623611
Ref: library/datetime datetime datetime utcoffset8625974
Ref: 28b58625974
Ref: library/datetime datetime datetime dst8626373
Ref: 28b68626373
Ref: library/datetime datetime datetime tzname8626760
Ref: 28b88626760
Ref: library/datetime datetime datetime timetuple8626993
Ref: 28b98626993
Ref: library/datetime datetime datetime utctimetuple8627836
Ref: 28bb8627836
Ref: library/datetime datetime datetime toordinal8629010
Ref: 28bc8629010
Ref: library/datetime datetime datetime timestamp8629152
Ref: 12a28629152
Ref: library/datetime datetime datetime weekday8630702
Ref: 28bd8630702
Ref: library/datetime datetime datetime isoweekday8630906
Ref: 28be8630906
Ref: library/datetime datetime datetime isocalendar8631139
Ref: af48631139
Ref: library/datetime datetime datetime isoformat8631331
Ref: d278631331
Ref: library/datetime datetime datetime __str__8634325
Ref: 28bf8634325
Ref: library/datetime datetime datetime ctime8634468
Ref: 28c08634468
Ref: library/datetime datetime datetime strftime8635101
Ref: e908635101
Ref: library/datetime datetime datetime __format__8635341
Ref: 28c18635341
Node: Examples of Usage datetime8635779
Ref: library/datetime examples-of-usage-datetime8635858
Ref: 28c28635858
Node: time Objects8640186
Ref: library/datetime datetime-time8640321
Ref: 28c38640321
Ref: library/datetime time-objects8640321
Ref: 28c48640321
Ref: library/datetime datetime time8640529
Ref: 1fb8640529
Ref: library/datetime datetime time min8641184
Ref: 28c58641184
Ref: library/datetime datetime time max8641283
Ref: 28c68641283
Ref: library/datetime datetime time resolution8641393
Ref: 28c78641393
Ref: library/datetime datetime time hour8641661
Ref: 28858641661
Ref: library/datetime datetime time minute8641713
Ref: 28868641713
Ref: library/datetime datetime time second8641767
Ref: 28878641767
Ref: library/datetime datetime time microsecond8641821
Ref: 28888641821
Ref: library/datetime datetime time tzinfo8641885
Ref: 28898641885
Ref: library/datetime datetime time fold8642036
Ref: e8f8642036
Ref: library/datetime datetime time fromisoformat8643643
Ref: 82a8643643
Ref: library/datetime datetime time strptime8645223
Ref: 19348645223
Ref: library/datetime datetime time replace8645876
Ref: 19e28645876
Ref: library/datetime datetime time isoformat8646466
Ref: 28c88646466
Ref: library/datetime datetime time __str__8648487
Ref: 28ca8648487
Ref: library/datetime datetime time strftime8648593
Ref: 1ae08648593
Ref: library/datetime datetime time __format__8648817
Ref: 28cb8648817
Ref: library/datetime datetime time utcoffset8649172
Ref: 28c98649172
Ref: library/datetime datetime time dst8649567
Ref: 28cc8649567
Ref: library/datetime datetime time tzname8649951
Ref: 28cd8649951
Ref: time Objects-Footnote-18650280
Node: Examples of Usage time8650345
Ref: library/datetime examples-of-usage-time8650416
Ref: 28ce8650416
Node: tzinfo Objects8651298
Ref: library/datetime datetime-tzinfo8651433
Ref: 28cf8651433
Ref: library/datetime tzinfo-objects8651433
Ref: 28d08651433
Ref: library/datetime datetime tzinfo8651490
Ref: 7f78651490
Ref: library/datetime datetime tzinfo utcoffset8653125
Ref: 28d18653125
Ref: library/datetime datetime tzinfo dst8654360
Ref: 28d28654360
Ref: library/datetime datetime tzinfo tzname8656960
Ref: 28d38656960
Ref: library/datetime datetime tzinfo fromutc8659109
Ref: 28b78659109
Ref: tzinfo Objects-Footnote-18671651
Node: timezone Objects8671691
Ref: library/datetime datetime-timezone8671844
Ref: 28d48671844
Ref: library/datetime timezone-objects8671844
Ref: 28d58671844
Ref: library/datetime datetime timezone8672267
Ref: 12c78672267
Ref: library/datetime datetime timezone utcoffset8672903
Ref: 28d68672903
Ref: library/datetime datetime timezone tzname8673299
Ref: 28d78673299
Ref: library/datetime datetime timezone dst8673981
Ref: 28d88673981
Ref: library/datetime datetime timezone fromutc8674045
Ref: 28d98674045
Ref: library/datetime datetime timezone utc8674240
Ref: 8288674240
Node: strftime and strptime Behavior8674324
Ref: library/datetime strftime-and-strptime-behavior8674454
Ref: 28da8674454
Ref: library/datetime strftime-strptime-behavior8674454
Ref: 1b3c8674454
Ref: library/datetime format-codes8676271
Ref: 287b8676271
Node: strftime and strptime Format Codes8676380
Ref: library/datetime strftime-and-strptime-format-codes8676506
Ref: 28db8676506
Ref: strftime and strptime Format Codes-Footnote-18687417
Node: Technical Detail8687465
Ref: library/datetime technical-detail8687591
Ref: 28dc8687591
Ref: Technical Detail-Footnote-18695223
Node: zoneinfo — IANA time zone support8695278
Ref: library/zoneinfo doc8695463
Ref: 28dd8695463
Ref: library/zoneinfo module-zoneinfo8695463
Ref: 13a8695463
Ref: library/zoneinfo translation-repo8695463
Ref: 28de8695463
Ref: library/zoneinfo zoneinfo-iana-time-zone-support8695463
Ref: 28df8695463
Ref: zoneinfo — IANA time zone support-Footnote-18696699
Ref: zoneinfo — IANA time zone support-Footnote-28696764
Ref: zoneinfo — IANA time zone support-Footnote-38696806
Ref: zoneinfo — IANA time zone support-Footnote-48696847
Node: Using ZoneInfo8696888
Ref: library/zoneinfo using-zoneinfo8696995
Ref: 28e08696995
Ref: Using ZoneInfo-Footnote-18698943
Node: Data sources8698985
Ref: library/zoneinfo data-sources8699119
Ref: 28e18699119
Ref: Data sources-Footnote-18699803
Node: Configuring the data sources8699844
Ref: library/zoneinfo configuring-the-data-sources8699921
Ref: 28e28699921
Ref: library/zoneinfo zoneinfo-data-configuration8699921
Ref: 28e38699921
Node: Compile-time configuration8700674
Ref: library/zoneinfo compile-time-configuration8700799
Ref: 28e68700799
Ref: library/zoneinfo zoneinfo-data-compile-time-config8700799
Ref: 21508700799
Node: Environment configuration8701531
Ref: library/zoneinfo environment-configuration8701686
Ref: 28e78701686
Ref: library/zoneinfo zoneinfo-data-environment-var8701686
Ref: 28e48701686
Ref: library/zoneinfo envvar-PYTHONTZPATH8702005
Ref: 28e88702005
Node: Runtime configuration8702666
Ref: library/zoneinfo runtime-configuration8702786
Ref: 28ea8702786
Ref: library/zoneinfo zoneinfo-data-runtime-config8702786
Ref: 28e58702786
Node: The ZoneInfo class8703154
Ref: library/zoneinfo the-zoneinfo-class8703286
Ref: 28eb8703286
Ref: library/zoneinfo zoneinfo ZoneInfo8703349
Ref: ade8703349
Ref: library/zoneinfo zoneinfo ZoneInfo from_file8704230
Ref: 17638704230
Ref: library/zoneinfo zoneinfo ZoneInfo no_cache8704867
Ref: 28ee8704867
Ref: library/zoneinfo zoneinfo ZoneInfo clear_cache8705592
Ref: 28ec8705592
Ref: library/zoneinfo zoneinfo ZoneInfo key8706393
Ref: 28ef8706393
Node: String representations8707249
Ref: library/zoneinfo string-representations8707355
Ref: 28f18707355
Node: Pickle serialization8708164
Ref: library/zoneinfo pickle-serialization8708270
Ref: 28f28708270
Ref: library/zoneinfo pickling8708270
Ref: 28ed8708270
Node: Functions<2>8710665
Ref: library/zoneinfo functions8710792
Ref: 28f38710792
Ref: library/zoneinfo zoneinfo available_timezones8710831
Ref: 1d308710831
Ref: library/zoneinfo zoneinfo reset_tzpath8711806
Ref: 17a88711806
Node: Globals8712502
Ref: library/zoneinfo globals8712634
Ref: 28f48712634
Ref: library/zoneinfo zoneinfo TZPATH8712669
Ref: 214f8712669
Node: Exceptions and warnings8713444
Ref: library/zoneinfo exceptions-and-warnings8713555
Ref: 28f58713555
Ref: library/zoneinfo zoneinfo ZoneInfoNotFoundError8713622
Ref: 17fe8713622
Ref: library/zoneinfo zoneinfo InvalidTZPathWarning8713853
Ref: 28e98713853
Node: calendar — General calendar-related functions8714030
Ref: library/calendar doc8714212
Ref: 28f68714212
Ref: library/calendar calendar-general-calendar-related-functions8714212
Ref: 28f78714212
Ref: library/calendar module-calendar8714212
Ref: 158714212
Ref: library/calendar translation-repo8714212
Ref: 28f88714212
Ref: library/calendar calendar Calendar8715410
Ref: 28fa8715410
Ref: library/calendar calendar Calendar firstweekday8715964
Ref: 28fd8715964
Ref: library/calendar calendar Calendar getfirstweekday8716206
Ref: 28ff8716206
Ref: library/calendar calendar Calendar setfirstweekday8716391
Ref: 28fe8716391
Ref: library/calendar calendar Calendar iterweekdays8716611
Ref: 29008716611
Ref: library/calendar calendar Calendar itermonthdates8716860
Ref: e158716860
Ref: library/calendar calendar Calendar itermonthdays8717232
Ref: 29018717232
Ref: library/calendar calendar Calendar itermonthdays28717617
Ref: 29028717617
Ref: library/calendar calendar Calendar itermonthdays38717967
Ref: e168717967
Ref: library/calendar calendar Calendar itermonthdays48718349
Ref: e178718349
Ref: library/calendar calendar Calendar monthdatescalendar8718751
Ref: 29038718751
Ref: library/calendar calendar Calendar monthdays2calendar8718971
Ref: 29048718971
Ref: library/calendar calendar Calendar monthdayscalendar8719199
Ref: 29058719199
Ref: library/calendar calendar Calendar yeardatescalendar8719386
Ref: 29068719386
Ref: library/calendar calendar Calendar yeardays2calendar8719780
Ref: 29078719780
Ref: library/calendar calendar Calendar yeardayscalendar8720096
Ref: 29088720096
Ref: library/calendar calendar TextCalendar8720381
Ref: 18928720381
Ref: library/calendar calendar TextCalendar formatday8720566
Ref: 29098720566
Ref: library/calendar calendar TextCalendar formatweek8720874
Ref: 290a8720874
Ref: library/calendar calendar TextCalendar formatweekday8721219
Ref: 290b8721219
Ref: library/calendar calendar TextCalendar formatweekheader8721523
Ref: 290c8721523
Ref: library/calendar calendar TextCalendar formatmonth8721797
Ref: 290d8721797
Ref: library/calendar calendar TextCalendar formatmonthname8722246
Ref: 290e8722246
Ref: library/calendar calendar TextCalendar prmonth8722650
Ref: 290f8722650
Ref: library/calendar calendar TextCalendar formatyear8722796
Ref: 29108722796
Ref: library/calendar calendar TextCalendar pryear8723333
Ref: 29118723333
Ref: library/calendar calendar HTMLCalendar8723488
Ref: d1a8723488
Ref: library/calendar calendar HTMLCalendar formatmonth8723660
Ref: 29128723660
Ref: library/calendar calendar HTMLCalendar formatyear8723910
Ref: 29138723910
Ref: library/calendar calendar HTMLCalendar formatyearpage8724091
Ref: 29148724091
Ref: library/calendar calendar HTMLCalendar formatmonthname8724604
Ref: 29158724604
Ref: library/calendar calendar HTMLCalendar cssclasses8724978
Ref: 29168724978
Ref: library/calendar calendar HTMLCalendar cssclass_noday8725392
Ref: 29178725392
Ref: library/calendar calendar HTMLCalendar cssclasses_weekday_head8725553
Ref: 29188725553
Ref: library/calendar calendar HTMLCalendar cssclass_month_head8725768
Ref: 29198725768
Ref: library/calendar calendar HTMLCalendar cssclass_month8725971
Ref: 291a8725971
Ref: library/calendar calendar HTMLCalendar cssclass_year8726180
Ref: 291b8726180
Ref: library/calendar calendar HTMLCalendar cssclass_year_head8726395
Ref: 291c8726395
Ref: library/calendar calendar LocaleTextCalendar8727304
Ref: 94c8727304
Ref: library/calendar calendar LocaleHTMLCalendar8727546
Ref: 94d8727546
Ref: library/calendar calendar setfirstweekday8728131
Ref: 28f98728131
Ref: library/calendar calendar firstweekday8728605
Ref: 29228728605
Ref: library/calendar calendar isleap8728715
Ref: 29238728715
Ref: library/calendar calendar leapdays8728843
Ref: 29248728843
Ref: library/calendar calendar weekday8729068
Ref: 29258729068
Ref: library/calendar calendar weekheader8729267
Ref: 29268729267
Ref: library/calendar calendar monthrange8729427
Ref: 29278729427
Ref: library/calendar calendar monthcalendar8729596
Ref: 29288729596
Ref: library/calendar calendar prmonth8729877
Ref: 29298729877
Ref: library/calendar calendar month8730009
Ref: 18f38730009
Ref: library/calendar calendar prcal8730209
Ref: 292a8730209
Ref: library/calendar calendar calendar8730353
Ref: 292b8730353
Ref: library/calendar calendar timegm8730575
Ref: 292c8730575
Ref: library/calendar calendar day_name8731052
Ref: 292d8731052
Ref: library/calendar calendar day_abbr8731351
Ref: 292e8731351
Ref: library/calendar calendar MONDAY8731630
Ref: 28fb8731630
Ref: library/calendar calendar TUESDAY8731656
Ref: 291d8731656
Ref: library/calendar calendar WEDNESDAY8731683
Ref: 291e8731683
Ref: library/calendar calendar THURSDAY8731712
Ref: 291f8731712
Ref: library/calendar calendar FRIDAY8731740
Ref: 29208731740
Ref: library/calendar calendar SATURDAY8731766
Ref: 29218731766
Ref: library/calendar calendar SUNDAY8731794
Ref: 28fc8731794
Ref: library/calendar calendar Day8731954
Ref: 6ab8731954
Ref: library/calendar calendar month_name8732202
Ref: 292f8732202
Ref: library/calendar calendar month_abbr8732670
Ref: 29308732670
Ref: library/calendar calendar JANUARY8733112
Ref: 34e8733112
Ref: library/calendar calendar FEBRUARY8733139
Ref: 34f8733139
Ref: library/calendar calendar MARCH8733167
Ref: 29318733167
Ref: library/calendar calendar APRIL8733192
Ref: 29328733192
Ref: library/calendar calendar MAY8733217
Ref: 29338733217
Ref: library/calendar calendar JUNE8733240
Ref: 29348733240
Ref: library/calendar calendar JULY8733264
Ref: 29358733264
Ref: library/calendar calendar AUGUST8733288
Ref: 29368733288
Ref: library/calendar calendar SEPTEMBER8733314
Ref: 29378733314
Ref: library/calendar calendar OCTOBER8733343
Ref: 29388733343
Ref: library/calendar calendar NOVEMBER8733370
Ref: 29398733370
Ref: library/calendar calendar DECEMBER8733398
Ref: 293a8733398
Ref: library/calendar calendar Month8733566
Ref: 6aa8733566
Ref: library/calendar calendar IllegalMonthError8733886
Ref: 18f28733886
Ref: library/calendar calendar IllegalMonthError month8734062
Ref: 293b8734062
Ref: library/calendar calendar IllegalWeekdayError8734126
Ref: 293c8734126
Ref: library/calendar calendar IllegalWeekdayError weekday8734307
Ref: 293d8734307
Ref: calendar — General calendar-related functions-Footnote-18734673
Node: Command-line usage8734741
Ref: library/calendar calendar-cli8734843
Ref: 1d08734843
Ref: library/calendar command-line-usage8734843
Ref: 293e8734843
Ref: library/calendar cmdoption-calendar-help8737587
Ref: 293f8737587
Ref: library/calendar cmdoption-calendar-h8737587
Ref: 29408737587
Ref: library/calendar cmdoption-calendar-locale8737649
Ref: 29418737649
Ref: library/calendar cmdoption-calendar-L8737649
Ref: 29428737649
Ref: library/calendar cmdoption-calendar-encoding8737769
Ref: 29438737769
Ref: library/calendar cmdoption-calendar-e8737769
Ref: 29448737769
Ref: library/calendar cmdoption-calendar-type8737926
Ref: 29458737926
Ref: library/calendar cmdoption-calendar-t8737926
Ref: 29468737926
Ref: library/calendar cmdoption-calendar-first-weekday8738048
Ref: 29478738048
Ref: library/calendar cmdoption-calendar-f8738048
Ref: 29488738048
Ref: library/calendar cmdoption-calendar-arg-year8738250
Ref: 29498738250
Ref: library/calendar cmdoption-calendar-arg-month8738341
Ref: 294a8738341
Ref: library/calendar cmdoption-calendar-width8738593
Ref: 294b8738593
Ref: library/calendar cmdoption-calendar-w8738593
Ref: 294c8738593
Ref: library/calendar cmdoption-calendar-lines8738791
Ref: 294d8738791
Ref: library/calendar cmdoption-calendar-l8738791
Ref: 294e8738791
Ref: library/calendar cmdoption-calendar-spacing8738982
Ref: 294f8738982
Ref: library/calendar cmdoption-calendar-s8738982
Ref: 29508738982
Ref: library/calendar cmdoption-calendar-months8739125
Ref: 29518739125
Ref: library/calendar cmdoption-calendar-m8739125
Ref: 29528739125
Ref: library/calendar cmdoption-calendar-css8739391
Ref: 29538739391
Ref: library/calendar cmdoption-calendar-c8739391
Ref: 29548739391
Node: collections — Container datatypes8739588
Ref: library/collections doc8739791
Ref: 29558739791
Ref: library/collections collections-container-datatypes8739791
Ref: 29568739791
Ref: library/collections module-collections8739791
Ref: 1e8739791
Ref: library/collections translation-repo8739791
Ref: 29578739791
Ref: collections — Container datatypes-Footnote-18741782
Node: ChainMap objects8741863
Ref: library/collections chainmap-objects8741975
Ref: 29588741975
Ref: library/collections collections ChainMap8742365
Ref: e188742365
Ref: library/collections collections ChainMap maps8743399
Ref: 29598743399
Ref: library/collections collections ChainMap new_child8743702
Ref: 11278743702
Ref: library/collections collections ChainMap parents8744546
Ref: 295a8744546
Ref: ChainMap objects-Footnote-18746519
Ref: ChainMap objects-Footnote-28746561
Ref: ChainMap objects-Footnote-38746656
Ref: ChainMap objects-Footnote-48746703
Ref: ChainMap objects-Footnote-58746782
Ref: ChainMap objects-Footnote-68746879
Node: ChainMap Examples and Recipes8746932
Ref: library/collections chainmap-examples-and-recipes8747014
Ref: 295b8747014
Node: Counter objects8750128
Ref: library/collections counter-objects8750262
Ref: 295c8750262
Ref: library/collections collections Counter8750976
Ref: 12998750976
Ref: library/collections collections Counter elements8752975
Ref: 150b8752975
Ref: library/collections collections Counter most_common8753399
Ref: 150a8753399
Ref: library/collections collections Counter subtract8753860
Ref: 13e68753860
Ref: library/collections collections Counter total8754416
Ref: 295d8754416
Ref: library/collections collections Counter fromkeys8754753
Ref: 295e8754753
Ref: library/collections collections Counter update8754883
Ref: 17648754883
Ref: Counter objects-Footnote-18760010
Ref: Counter objects-Footnote-28760089
Ref: Counter objects-Footnote-38760136
Node: deque objects8760229
Ref: library/collections deque-objects8760366
Ref: 295f8760366
Ref: library/collections collections deque8760419
Ref: 7f58760419
Ref: library/collections collections deque append8761865
Ref: 29608761865
Ref: library/collections collections deque appendleft8761945
Ref: 29618761945
Ref: library/collections collections deque clear8762028
Ref: 29628762028
Ref: library/collections collections deque copy8762127
Ref: fd48762127
Ref: library/collections collections deque count8762233
Ref: 13e88762233
Ref: library/collections collections deque extend8762354
Ref: 29638762354
Ref: library/collections collections deque extendleft8762496
Ref: 29648762496
Ref: library/collections collections deque index8762743
Ref: fd28762743
Ref: library/collections collections deque insert8763017
Ref: fd38763017
Ref: library/collections collections deque pop8763265
Ref: 29658763265
Ref: library/collections collections deque popleft8763436
Ref: 29668763436
Ref: library/collections collections deque remove8763610
Ref: 1cb78763610
Ref: library/collections collections deque reverse8763751
Ref: 13e98763751
Ref: library/collections collections deque rotate8763905
Ref: 1c788763905
Ref: library/collections collections deque maxlen8764314
Ref: 150c8764314
Node: deque Recipes8766973
Ref: library/collections deque-recipes8767036
Ref: 29678767036
Ref: deque Recipes-Footnote-18769500
Node: defaultdict objects8769561
Ref: library/collections defaultdict-objects8769739
Ref: 29688769739
Ref: library/collections collections defaultdict8769804
Ref: 13c48769804
Ref: library/collections collections defaultdict __missing__8770593
Ref: 296a8770593
Ref: library/collections collections defaultdict default_factory8771800
Ref: 29698771800
Ref: defaultdict objects-Footnote-18772227
Node: defaultdict Examples8772269
Ref: library/collections defaultdict-examples8772345
Ref: 296b8772345
Node: namedtuple Factory Function for Tuples with Named Fields8775033
Ref: library/collections namedtuple-factory-function-for-tuples-with-named-fields8775217
Ref: 296c8775217
Ref: library/collections collections namedtuple8775598
Ref: 4e18775598
Ref: library/collections collections somenamedtuple _make8779662
Ref: 296e8779662
Ref: library/collections collections somenamedtuple _asdict8779893
Ref: bd68779893
Ref: library/collections collections somenamedtuple _replace8780589
Ref: 296f8780589
Ref: library/collections collections somenamedtuple _fields8781213
Ref: 29708781213
Ref: library/collections collections somenamedtuple _field_defaults8781709
Ref: 296d8781709
Node: OrderedDict objects8784503
Ref: library/collections ordereddict-objects8784684
Ref: 29718784684
Ref: library/collections collections OrderedDict8787106
Ref: 7f48787106
Ref: library/collections collections OrderedDict popitem8787305
Ref: 14f58787305
Ref: library/collections collections OrderedDict move_to_end8787586
Ref: 13e78787586
Ref: library/collections collections-ordereddict-eq8788305
Ref: 19318788305
Ref: OrderedDict objects-Footnote-18789250
Ref: OrderedDict objects-Footnote-28789292
Node: OrderedDict Examples and Recipes8789334
Ref: library/collections ordereddict-examples-and-recipes8789422
Ref: 29738789422
Node: UserDict objects8792463
Ref: library/collections userdict-objects8792604
Ref: 29748792604
Ref: library/collections collections UserDict8792970
Ref: 1d658792970
Ref: library/collections collections UserDict data8793564
Ref: 29758793564
Node: UserList objects8793692
Ref: library/collections userlist-objects8793832
Ref: 29768793832
Ref: library/collections collections UserList8794347
Ref: 16eb8794347
Ref: library/collections collections UserList data8794953
Ref: 29778794953
Node: UserString objects8795747
Ref: library/collections userstring-objects8795862
Ref: 29788795862
Ref: library/collections collections UserString8796224
Ref: fd58796224
Ref: library/collections collections UserString data8796819
Ref: 29798796819
Node: collections abc — Abstract Base Classes for Containers8797129
Ref: library/collections abc doc8797315
Ref: 297a8797315
Ref: library/collections abc collections-abc-abstract-base-classes-for-containers8797315
Ref: 297b8797315
Ref: library/collections abc module-collections abc8797315
Ref: 1f8797315
Ref: library/collections abc translation-repo8797315
Ref: 297c8797315
Ref: collections abc — Abstract Base Classes for Containers-Footnote-18801329
Ref: collections abc — Abstract Base Classes for Containers-Footnote-28801406
Node: Collections Abstract Base Classes8801448
Ref: library/collections abc collections-abstract-base-classes8801642
Ref: a7a8801642
Ref: library/collections abc id18801642
Ref: 297d8801642
Ref: Collections Abstract Base Classes-Footnote-18811349
Ref: Collections Abstract Base Classes-Footnote-28811638
Ref: Collections Abstract Base Classes-Footnote-38811927
Ref: Collections Abstract Base Classes-Footnote-48812216
Ref: Collections Abstract Base Classes-Footnote-58812568
Ref: Collections Abstract Base Classes-Footnote-68812857
Ref: Collections Abstract Base Classes-Footnote-78813146
Ref: Collections Abstract Base Classes-Footnote-88813435
Ref: Collections Abstract Base Classes-Footnote-98813724
Ref: Collections Abstract Base Classes-Footnote-108814013
Ref: Collections Abstract Base Classes-Footnote-118814303
Ref: Collections Abstract Base Classes-Footnote-128814593
Ref: Collections Abstract Base Classes-Footnote-138814883
Ref: Collections Abstract Base Classes-Footnote-148815173
Ref: Collections Abstract Base Classes-Footnote-158815463
Ref: Collections Abstract Base Classes-Footnote-168815753
Node: Collections Abstract Base Classes – Detailed Descriptions8816043
Ref: library/collections abc collections-abstract-base-classes-detailed-descriptions8816266
Ref: 297f8816266
Ref: library/collections abc collections abc Container8816401
Ref: 26938816401
Ref: library/collections abc collections abc Hashable8816520
Ref: 71a8816520
Ref: library/collections abc collections abc Sized8816628
Ref: 71b8816628
Ref: library/collections abc collections abc Callable8816733
Ref: 9ed8816733
Ref: library/collections abc collections abc Iterable8816959
Ref: 26918816959
Ref: library/collections abc collections abc Collection8817443
Ref: e868817443
Ref: library/collections abc collections abc Iterator8817559
Ref: 26928817559
Ref: library/collections abc collections abc Reversible8817756
Ref: e878817756
Ref: library/collections abc collections abc Generator8817917
Ref: fdd8817917
Ref: library/collections abc collections abc Sequence8818335
Ref: 13cc8818335
Ref: library/collections abc collections abc MutableSequence8818372
Ref: 4c08818372
Ref: library/collections abc collections abc ByteString8818416
Ref: 3428818416
Ref: library/collections abc collections abc ByteString index8819058
Ref: 29818819058
Ref: library/collections abc collections abc Set8820461
Ref: 26898820461
Ref: library/collections abc collections abc MutableSet8820493
Ref: 26948820493
Ref: library/collections abc collections abc Mapping8820588
Ref: ac98820588
Ref: library/collections abc collections abc MutableMapping8820624
Ref: 12b48820624
Ref: library/collections abc collections abc MappingView8820727
Ref: 26958820727
Ref: library/collections abc collections abc ItemsView8820767
Ref: 26978820767
Ref: library/collections abc collections abc KeysView8820805
Ref: 26968820805
Ref: library/collections abc collections abc ValuesView8820842
Ref: 26988820842
Ref: library/collections abc collections abc Awaitable8820949
Ref: fde8820949
Ref: library/collections abc collections abc Coroutine8821708
Ref: fdf8821708
Ref: library/collections abc collections abc AsyncIterable8822760
Ref: fe18822760
Ref: library/collections abc collections abc AsyncIterator8822960
Ref: fe08822960
Ref: library/collections abc collections abc AsyncGenerator8823177
Ref: e898823177
Ref: library/collections abc collections abc Buffer8823506
Ref: 3438823506
Ref: Collections Abstract Base Classes – Detailed Descriptions-Footnote-18823746
Ref: Collections Abstract Base Classes – Detailed Descriptions-Footnote-28823788
Ref: Collections Abstract Base Classes – Detailed Descriptions-Footnote-38823846
Ref: Collections Abstract Base Classes – Detailed Descriptions-Footnote-48823888
Ref: Collections Abstract Base Classes – Detailed Descriptions-Footnote-58823930
Node: Examples and Recipes8823972
Ref: library/collections abc examples-and-recipes8824153
Ref: 29828824153
Ref: Examples and Recipes-Footnote-18827128
Ref: Examples and Recipes-Footnote-28827181
Node: heapq — Heap queue algorithm8827223
Ref: library/heapq doc8827410
Ref: 29838827410
Ref: library/heapq heapq-heap-queue-algorithm8827410
Ref: 29848827410
Ref: library/heapq module-heapq8827410
Ref: 6d8827410
Ref: library/heapq translation-repo8827410
Ref: 29858827410
Ref: library/heapq heapq heapify8829768
Ref: 29868829768
Ref: library/heapq heapq heappush8829869
Ref: 16c38829869
Ref: library/heapq heapq heappop8829998
Ref: 16c48829998
Ref: library/heapq heapq heappushpop8830267
Ref: 29878830267
Ref: library/heapq heapq heapreplace8830540
Ref: 29888830540
Ref: library/heapq heapq heapify_max8831370
Ref: 2218831370
Ref: library/heapq heapq heappush_max8831504
Ref: 2228831504
Ref: library/heapq heapq heappop_max8831675
Ref: 2238831675
Ref: library/heapq heapq heappushpop_max8831991
Ref: 2258831991
Ref: library/heapq heapq heapreplace_max8832309
Ref: 2248832309
Ref: library/heapq heapq merge8832821
Ref: 10078832821
Ref: library/heapq heapq nlargest8833990
Ref: 29898833990
Ref: library/heapq heapq nsmallest8834388
Ref: 298a8834388
Ref: heapq — Heap queue algorithm-Footnote-18835282
Node: Basic Examples8835347
Ref: library/heapq basic-examples8835455
Ref: 298b8835455
Ref: Basic Examples-Footnote-18836422
Node: Other Applications8836469
Ref: library/heapq other-applications8836621
Ref: 298c8836621
Ref: Other Applications-Footnote-18837883
Ref: Other Applications-Footnote-28837928
Node: Priority Queue Implementation Notes8837983
Ref: library/heapq priority-queue-implementation-notes8838127
Ref: 298d8838127
Ref: Priority Queue Implementation Notes-Footnote-18841063
Node: Theory8841116
Ref: library/heapq theory8841233
Ref: 298e8841233
Ref: Theory-Footnote-18845387
Node: bisect — Array bisection algorithm8846041
Ref: library/bisect doc8846216
Ref: 298f8846216
Ref: library/bisect bisect-array-bisection-algorithm8846216
Ref: 29908846216
Ref: library/bisect module-bisect8846216
Ref: 128846216
Ref: library/bisect translation-repo8846216
Ref: 29918846216
Ref: library/bisect bisect-functions8847647
Ref: 29938847647
Ref: library/bisect bisect bisect_left8847686
Ref: 29948847686
Ref: library/bisect bisect bisect_right8848887
Ref: 29958848887
Ref: library/bisect bisect bisect8848958
Ref: 29968848958
Ref: library/bisect bisect insort_left8849497
Ref: 29928849497
Ref: library/bisect bisect insort_right8850154
Ref: 29978850154
Ref: library/bisect bisect insort8850225
Ref: 29988850225
Ref: bisect — Array bisection algorithm-Footnote-18851066
Node: Performance Notes8851132
Ref: library/bisect performance-notes8851253
Ref: 29998851253
Ref: Performance Notes-Footnote-18852634
Ref: Performance Notes-Footnote-28852689
Node: Searching Sorted Lists8852759
Ref: library/bisect searching-sorted-lists8852900
Ref: 299a8852900
Node: Examples<3>8854122
Ref: library/bisect examples8854237
Ref: 299b8854237
Ref: library/bisect bisect-example8854272
Ref: 299c8854272
Node: array — Efficient arrays of numeric values8856799
Ref: library/array doc8856971
Ref: 299d8856971
Ref: library/array array-efficient-arrays-of-numeric-values8856971
Ref: 299e8856971
Ref: library/array module-array8856971
Ref: 88856971
Ref: library/array translation-repo8856971
Ref: 299f8856971
Ref: library/array array typecodes8861934
Ref: 29a18861934
Ref: library/array array array8862047
Ref: 4bf8862047
Ref: library/array array array typecode8863327
Ref: 29a48863327
Ref: library/array array array itemsize8863417
Ref: 29a08863417
Ref: library/array array array append8863538
Ref: 29a58863538
Ref: library/array array array buffer_info8863636
Ref: 29a68863636
Ref: library/array array array byteswap8864753
Ref: 29a78864753
Ref: library/array array array count8865102
Ref: 29a88865102
Ref: library/array array array extend8865195
Ref: 29a38865195
Ref: library/array array array frombytes8865579
Ref: 14798865579
Ref: library/array array array fromfile8865958
Ref: 14c88865958
Ref: library/array array array fromlist8866298
Ref: 29a98866298
Ref: library/array array array fromunicode8866509
Ref: 29a28866509
Ref: library/array array array index8866863
Ref: 9e38866863
Ref: library/array array array insert8867315
Ref: 29aa8867315
Ref: library/array array array pop8867517
Ref: 29ab8867517
Ref: library/array array array remove8867746
Ref: 29ac8867746
Ref: library/array array array clear8867837
Ref: 4c18867837
Ref: library/array array array reverse8867945
Ref: 29ad8867945
Ref: library/array array array tobytes8868030
Ref: 14788868030
Ref: library/array array array tofile8868382
Ref: 14c98868382
Ref: library/array array array tolist8868505
Ref: 29ae8868505
Ref: library/array array array tounicode8868603
Ref: 29af8868603
Ref: array — Efficient arrays of numeric values-Footnote-18869855
Node: weakref — Weak references8869882
Ref: library/weakref doc8870078
Ref: 29b08870078
Ref: library/weakref mod-weakref8870078
Ref: 110f8870078
Ref: library/weakref module-weakref8870078
Ref: 11a8870078
Ref: library/weakref translation-repo8870078
Ref: 29b18870078
Ref: library/weakref weakref-weak-references8870078
Ref: 29b28870078
Ref: library/weakref weakref ref8874161
Ref: 11f28874161
Ref: library/weakref weakref ref __callback__8875972
Ref: 11f38875972
Ref: library/weakref weakref proxy8876343
Ref: c488876343
Ref: library/weakref weakref getweakrefcount8877344
Ref: 29b48877344
Ref: library/weakref weakref getweakrefs8877477
Ref: 29b58877477
Ref: library/weakref weakref WeakKeyDictionary8877611
Ref: 19118877611
Ref: library/weakref weakref WeakKeyDictionary keyrefs8879464
Ref: 29b68879464
Ref: library/weakref weakref WeakValueDictionary8879567
Ref: 19128879567
Ref: library/weakref weakref WeakValueDictionary valuerefs8880045
Ref: 29b78880045
Ref: library/weakref weakref WeakSet8880154
Ref: 7f68880154
Ref: library/weakref weakref WeakMethod8880339
Ref: 11f18880339
Ref: library/weakref weakref finalize8881395
Ref: c718881395
Ref: library/weakref weakref finalize __call__8882699
Ref: 29b88882699
Ref: library/weakref weakref finalize detach8882910
Ref: 29b98882910
Ref: library/weakref weakref finalize peek8883111
Ref: 29ba8883111
Ref: library/weakref weakref finalize alive8883280
Ref: 29bb8883280
Ref: library/weakref weakref finalize atexit8883395
Ref: 29bc8883395
Ref: library/weakref weakref ReferenceType8883996
Ref: 1b458883996
Ref: library/weakref weakref ProxyType8884080
Ref: 1b468884080
Ref: library/weakref weakref CallableProxyType8884178
Ref: 1b478884178
Ref: library/weakref weakref ProxyTypes8884270
Ref: 29bd8884270
Ref: weakref — Weak references-Footnote-18884904
Ref: weakref — Weak references-Footnote-28884971
Ref: weakref — Weak references-Footnote-38885013
Ref: weakref — Weak references-Footnote-48885055
Node: Weak Reference Objects8885097
Ref: library/weakref weak-reference-objects8885202
Ref: 29be8885202
Ref: library/weakref weakref-objects8885202
Ref: 29bf8885202
Node: Example<2>8887727
Ref: library/weakref example8887858
Ref: 29c08887858
Ref: library/weakref weakref-example8887858
Ref: 29c18887858
Node: Finalizer Objects8888399
Ref: library/weakref finalize-examples8888549
Ref: 29c28888549
Ref: library/weakref finalizer-objects8888549
Ref: 29c38888549
Node: Comparing finalizers with __del__ methods8890400
Ref: library/weakref comparing-finalizers-with-del-methods8890531
Ref: 29c48890531
Node: types — Dynamic type creation and names for built-in types8893358
Ref: library/types doc8893551
Ref: 29c58893551
Ref: library/types module-types8893551
Ref: 1098893551
Ref: library/types translation-repo8893551
Ref: 29c68893551
Ref: library/types types-dynamic-type-creation-and-names-for-built-in-types8893551
Ref: 29c78893551
Ref: types — Dynamic type creation and names for built-in types-Footnote-18894354
Node: Dynamic Type Creation8894419
Ref: library/types dynamic-type-creation8894572
Ref: 29c88894572
Ref: library/types types new_class8894635
Ref: 13698894635
Ref: library/types types prepare_class8895351
Ref: 136a8895351
Ref: library/types types resolve_bases8896531
Ref: d978896531
Ref: library/types types get_original_bases8897101
Ref: 6f68897101
Ref: Dynamic Type Creation-Footnote-18898666
Ref: Dynamic Type Creation-Footnote-28898708
Ref: Dynamic Type Creation-Footnote-38898750
Ref: Dynamic Type Creation-Footnote-48898792
Node: Standard Interpreter Types8898834
Ref: library/types standard-interpreter-types8899036
Ref: 29c98899036
Ref: library/types types NoneType8899592
Ref: a548899592
Ref: library/types types FunctionType8899682
Ref: a858899682
Ref: library/types types LambdaType8899711
Ref: 29ca8899711
Ref: library/types types GeneratorType8900068
Ref: 19938900068
Ref: library/types types CoroutineType8900195
Ref: 108b8900195
Ref: library/types types AsyncGeneratorType8900352
Ref: 29cb8900352
Ref: library/types types CodeType8900538
Ref: 32f8900538
Ref: library/types types CellType8901133
Ref: 29cc8901133
Ref: library/types types MethodType8901311
Ref: 1b6b8901311
Ref: library/types types BuiltinFunctionType8901398
Ref: 29cd8901398
Ref: library/types types BuiltinMethodType8901434
Ref: 29ce8901434
Ref: library/types types WrapperDescriptorType8901653
Ref: d948901653
Ref: library/types types MethodWrapperType8901871
Ref: 85c8901871
Ref: library/types types NotImplementedType8902074
Ref: a558902074
Ref: library/types types MethodDescriptorType8902184
Ref: d958902184
Ref: library/types types ClassMethodDescriptorType8902341
Ref: d968902341
Ref: library/types types ModuleType8902528
Ref: 10168902528
Ref: library/types types EllipsisType8903314
Ref: a538903314
Ref: library/types types GenericAlias8903413
Ref: 9ee8903413
Ref: library/types types UnionType8904337
Ref: 2a78904337
Ref: library/types types TracebackType8904539
Ref: cec8904539
Ref: library/types types FrameType8904868
Ref: 1bd68904868
Ref: library/types types GetSetDescriptorType8905021
Ref: 29cf8905021
Ref: library/types types MemberDescriptorType8905388
Ref: 29d08905388
Ref: library/types types MappingProxyType8906199
Ref: 6998906199
Ref: library/types types MappingProxyType copy8907199
Ref: 29d18907199
Ref: library/types types MappingProxyType get8907285
Ref: 29d28907285
Ref: library/types types MappingProxyType items8907558
Ref: 29d38907558
Ref: library/types types MappingProxyType keys8907688
Ref: 29d48907688
Ref: library/types types MappingProxyType values8907779
Ref: 29d58907779
Ref: library/types types CapsuleType8908149
Ref: 29d68908149
Ref: Standard Interpreter Types-Footnote-18908292
Ref: Standard Interpreter Types-Footnote-28908334
Node: Additional Utility Classes and Functions8908376
Ref: library/types additional-utility-classes-and-functions8908584
Ref: 29d88908584
Ref: library/types types SimpleNamespace8908685
Ref: 4e68908685
Ref: library/types types DynamicClassAttribute8910722
Ref: 83d8910722
Node: Coroutine Utility Functions8911398
Ref: library/types coroutine-utility-functions8911571
Ref: 29d98911571
Ref: library/types types coroutine8911646
Ref: 108a8911646
Node: copy — Shallow and deep copy operations8912473
Ref: library/copy doc8912669
Ref: 29da8912669
Ref: library/copy copy-shallow-and-deep-copy-operations8912669
Ref: 29db8912669
Ref: library/copy module-copy8912669
Ref: 298912669
Ref: library/copy translation-repo8912669
Ref: 29dc8912669
Ref: library/copy copy copy8913224
Ref: 7588913224
Ref: library/copy copy deepcopy8913293
Ref: d678913293
Ref: library/copy copy replace8913371
Ref: 1c08913371
Ref: library/copy copy Error8913552
Ref: 29dd8913552
Ref: library/copy shallow-vs-deep-copy8913619
Ref: 1fce8913619
Ref: library/copy object __copy__8915657
Ref: 17c88915657
Ref: library/copy object __deepcopy__8915788
Ref: 17c98915788
Ref: library/copy object __replace__8916492
Ref: 47d8916492
Ref: copy — Shallow and deep copy operations-Footnote-18916873
Node: pprint — Data pretty printer8916937
Ref: library/pprint doc8917114
Ref: 29de8917114
Ref: library/pprint module-pprint8917114
Ref: b38917114
Ref: library/pprint pprint-data-pretty-printer8917114
Ref: 29df8917114
Ref: library/pprint translation-repo8917114
Ref: 29e08917114
Ref: pprint — Data pretty printer-Footnote-18918281
Node: Functions<3>8918347
Ref: library/pprint functions8918456
Ref: 29e18918456
Ref: library/pprint pprint-functions8918456
Ref: 29e28918456
Ref: library/pprint pprint pp8918495
Ref: c1a8918495
Ref: library/pprint pprint pprint8921089
Ref: a2b8921089
Ref: library/pprint pprint pformat8921489
Ref: 11828921489
Ref: library/pprint pprint isreadable8921941
Ref: 29e38921941
Ref: library/pprint pprint isrecursive8922247
Ref: 29e48922247
Ref: library/pprint pprint saferepr8922548
Ref: 29e58922548
Node: PrettyPrinter Objects8923196
Ref: library/pprint id18923324
Ref: 29e68923324
Ref: library/pprint prettyprinter-objects8923324
Ref: 29e78923324
Ref: library/pprint pprint PrettyPrinter8923387
Ref: 11818923387
Ref: library/pprint pprint PrettyPrinter pformat8925084
Ref: 29e88925084
Ref: library/pprint pprint PrettyPrinter pprint8925284
Ref: 29e98925284
Ref: library/pprint pprint PrettyPrinter isreadable8925672
Ref: 29ea8925672
Ref: library/pprint pprint PrettyPrinter isrecursive8926073
Ref: 29eb8926073
Ref: library/pprint pprint PrettyPrinter format8926389
Ref: 1ccf8926389
Node: Example<3>8927549
Ref: library/pprint example8927656
Ref: 29ec8927656
Ref: library/pprint pprint-example8927656
Ref: 29ed8927656
Ref: Example<3>-Footnote-18934954
Node: reprlib — Alternate repr implementation8934979
Ref: library/reprlib doc8935148
Ref: 29ee8935148
Ref: library/reprlib module-reprlib8935148
Ref: c08935148
Ref: library/reprlib reprlib-alternate-repr-implementation8935148
Ref: 29ef8935148
Ref: library/reprlib translation-repo8935148
Ref: 29f08935148
Ref: library/reprlib reprlib Repr8935639
Ref: 29f18935639
Ref: library/reprlib reprlib aRepr8936639
Ref: 29f38936639
Ref: library/reprlib reprlib repr8936922
Ref: 29f48936922
Ref: library/reprlib reprlib recursive_repr8937324
Ref: 13fb8937324
Ref: reprlib — Alternate repr implementation-Footnote-18938122
Node: Repr Objects8938189
Ref: library/reprlib id18938312
Ref: 29f28938312
Ref: library/reprlib repr-objects8938312
Ref: 29f68938312
Ref: library/reprlib reprlib Repr fillvalue8938553
Ref: 29f78938553
Ref: library/reprlib reprlib Repr maxlevel8938702
Ref: 29f88938702
Ref: library/reprlib reprlib Repr maxdict8938826
Ref: 29f98938826
Ref: library/reprlib reprlib Repr maxlist8938854
Ref: 29fa8938854
Ref: library/reprlib reprlib Repr maxtuple8938882
Ref: 29fb8938882
Ref: library/reprlib reprlib Repr maxset8938911
Ref: 29fc8938911
Ref: library/reprlib reprlib Repr maxfrozenset8938938
Ref: 29fd8938938
Ref: library/reprlib reprlib Repr maxdeque8938971
Ref: 29fe8938971
Ref: library/reprlib reprlib Repr maxarray8939000
Ref: 29ff8939000
Ref: library/reprlib reprlib Repr maxlong8939228
Ref: 2a008939228
Ref: library/reprlib reprlib Repr maxstring8939397
Ref: 2a018939397
Ref: library/reprlib reprlib Repr maxother8939752
Ref: 2a028939752
Ref: library/reprlib reprlib Repr indent8940031
Ref: 2a038940031
Ref: library/reprlib reprlib Repr repr8941526
Ref: 29f58941526
Ref: library/reprlib reprlib Repr repr18941666
Ref: 2a048941666
Node: Subclassing Repr Objects8942484
Ref: library/reprlib subclassing-repr-objects8942607
Ref: 2a058942607
Ref: library/reprlib subclassing-reprs8942607
Ref: 2a068942607
Node: enum — Support for enumerations8943304
Ref: library/enum doc8943507
Ref: 2a078943507
Ref: library/enum enum-support-for-enumerations8943507
Ref: 2a088943507
Ref: library/enum module-enum8943507
Ref: 5a8943507
Ref: library/enum translation-repo8943507
Ref: 2a098943507
Ref: enum — Support for enumerations-Footnote-18945401
Node: Module Contents<2>8945465
Ref: library/enum module-contents8945575
Ref: 2a0e8945575
Node: Data Types<2>8949307
Ref: library/enum data-types8949450
Ref: 2a128949450
Ref: library/enum enum EnumType8949491
Ref: 4f88949491
Ref: library/enum enum EnumType __call__8950115
Ref: 2a148950115
Ref: library/enum enum EnumType __contains__8951332
Ref: 2a158951332
Ref: library/enum enum EnumType __dir__8951767
Ref: 2a168951767
Ref: library/enum enum EnumType __getitem__8952154
Ref: 2a178952154
Ref: library/enum enum EnumType __iter__8952366
Ref: 2a188952366
Ref: library/enum enum EnumType __len__8952559
Ref: 2a198952559
Ref: library/enum enum EnumType __members__8952689
Ref: 2a1a8952689
Ref: library/enum enum EnumType __reversed__8952813
Ref: 2a1b8952813
Ref: library/enum enum Enum8953028
Ref: 8438953028
Ref: library/enum enum Enum name8953111
Ref: 2a1c8953111
Ref: library/enum enum Enum value8953253
Ref: 2a1d8953253
Ref: library/enum enum Enum _name_8954119
Ref: 2a1f8954119
Ref: library/enum enum Enum _value_8954178
Ref: 2a208954178
Ref: library/enum enum Enum _order_8954276
Ref: 2a218954276
Ref: library/enum enum Enum _ignore_8954426
Ref: 2a228954426
Ref: library/enum enum Enum __dir__8954793
Ref: 1bec8954793
Ref: library/enum enum Enum _generate_next_value_8955665
Ref: 2a248955665
Ref: library/enum enum Enum __init__8956588
Ref: 2a258956588
Ref: library/enum enum Enum __init_subclass__8957040
Ref: 2a268957040
Ref: library/enum enum Enum _missing_8957211
Ref: 2a278957211
Ref: library/enum enum Enum __new__8958078
Ref: 2a1e8958078
Ref: library/enum enum Enum __repr__8958744
Ref: 1ae28958744
Ref: library/enum enum Enum __str__8959520
Ref: 8358959520
Ref: library/enum enum Enum __format__8960195
Ref: 8338960195
Ref: library/enum enum Enum _add_alias_8961122
Ref: 2a288961122
Ref: library/enum enum Enum _add_value_alias_8961470
Ref: 2a298961470
Ref: library/enum enum IntEnum8961826
Ref: edd8961826
Ref: library/enum enum StrEnum8962874
Ref: 82e8962874
Ref: library/enum enum Flag8964279
Ref: 8368964279
Ref: library/enum enum Flag __contains__8964563
Ref: 2a2a8964563
Ref: library/enum enum Flag __or__8966002
Ref: 2a2b8966002
Ref: library/enum enum Flag __and__8966180
Ref: 2a2c8966180
Ref: library/enum enum Flag __xor__8966416
Ref: 2a2d8966416
Ref: library/enum enum Flag _numeric_repr_8966952
Ref: 2a2e8966952
Ref: library/enum enum IntFlag8967457
Ref: e9c8967457
Ref: library/enum enum ReprEnum8969086
Ref: 82f8969086
Ref: library/enum enum EnumCheck8969601
Ref: 8398969601
Ref: library/enum enum EnumCheck UNIQUE8969806
Ref: 2a2f8969806
Ref: library/enum enum EnumCheck CONTINUOUS8970293
Ref: 2a308970293
Ref: library/enum enum EnumCheck NAMED_FLAGS8970823
Ref: 2a318970823
Ref: library/enum enum FlagBoundary8971694
Ref: 8378971694
Ref: library/enum enum FlagBoundary STRICT8971840
Ref: 2a328971840
Ref: library/enum enum FlagBoundary CONFORM8972489
Ref: 2a338972489
Ref: library/enum enum FlagBoundary EJECT8972958
Ref: 2a348972958
Ref: library/enum enum FlagBoundary KEEP8973398
Ref: 2a358973398
Ref: library/enum enum EnumDict8973924
Ref: 4f78973924
Ref: library/enum enum EnumDict member_names8974647
Ref: 2a368974647
Node: Supported __dunder__ names8974883
Ref: library/enum supported-dunder-names8974992
Ref: 2a378974992
Node: Supported _sunder_ names8975421
Ref: library/enum supported-sunder-names8975530
Ref: 2a388975530
Ref: Supported _sunder_ names-Footnote-18977310
Node: Utilities and Decorators8977397
Ref: library/enum ipython-s-rich-display8977527
Ref: 2a398977527
Ref: library/enum utilities-and-decorators8977527
Ref: 2a3a8977527
Ref: library/enum enum auto8977596
Ref: e9d8977596
Ref: library/enum enum property8979136
Ref: 83c8979136
Ref: library/enum enum unique8979657
Ref: 2a108979657
Ref: library/enum enum verify8980287
Ref: 8388980287
Ref: library/enum enum member8980543
Ref: 83a8980543
Ref: library/enum enum nonmember8980669
Ref: 83b8980669
Ref: library/enum enum global_enum8980802
Ref: 83e8980802
Ref: library/enum enum show_flag_values8981171
Ref: 2a118981171
Ref: library/enum enum bin8981328
Ref: 17758981328
Node: Notes8981816
Ref: library/enum notes8981924
Ref: 2a0f8981924
Node: graphlib — Functionality to operate with graph-like structures8982858
Ref: library/graphlib doc8983011
Ref: 2a3b8983011
Ref: library/graphlib graphlib-functionality-to-operate-with-graph-like-structures8983011
Ref: 2a3c8983011
Ref: library/graphlib module-graphlib8983011
Ref: 698983011
Ref: library/graphlib translation-repo8983011
Ref: 2a3d8983011
Ref: library/graphlib graphlib TopologicalSorter8983265
Ref: ae08983265
Ref: library/graphlib graphlib TopologicalSorter add8986557
Ref: 2a3e8986557
Ref: library/graphlib graphlib TopologicalSorter prepare8987333
Ref: 21f8987333
Ref: library/graphlib graphlib TopologicalSorter is_active8988158
Ref: 2a3f8988158
Ref: library/graphlib graphlib TopologicalSorter done8989050
Ref: 2a418989050
Ref: library/graphlib graphlib TopologicalSorter get_ready8989745
Ref: 2a408989745
Ref: library/graphlib graphlib TopologicalSorter static_order8990300
Ref: 2a428990300
Ref: graphlib — Functionality to operate with graph-like structures-Footnote-18991837
Node: Exceptions<3>8991905
Ref: library/graphlib exceptions8992019
Ref: 2a448992019
Ref: library/graphlib graphlib CycleError8992133
Ref: 2a438992133
Node: Numeric and Mathematical Modules8992805
Ref: library/numeric doc8992959
Ref: 2a458992959
Ref: library/numeric numeric8992959
Ref: 2a468992959
Ref: library/numeric numeric-and-mathematical-modules8992959
Ref: 2a478992959
Ref: library/numeric translation-repo8992959
Ref: 2a488992959
Node: numbers — Numeric abstract base classes8993864
Ref: library/numbers doc8994014
Ref: 2a498994014
Ref: library/numbers module-numbers8994014
Ref: a28994014
Ref: library/numbers numbers-numeric-abstract-base-classes8994014
Ref: 2a4a8994014
Ref: library/numbers numbers Number8994444
Ref: 2a4b8994444
Ref: numbers — Numeric abstract base classes-Footnote-18994741
Ref: numbers — Numeric abstract base classes-Footnote-28994808
Node: The numeric tower8994850
Ref: library/numbers the-numeric-tower8994981
Ref: 2a4c8994981
Ref: library/numbers numbers Complex8995034
Ref: 25db8995034
Ref: library/numbers numbers Complex real8995486
Ref: 2a4d8995486
Ref: library/numbers numbers Complex imag8995579
Ref: 2a4e8995579
Ref: library/numbers numbers Complex conjugate8995677
Ref: 2a4f8995677
Ref: library/numbers numbers Real8995836
Ref: 25d18995836
Ref: library/numbers numbers Rational8996341
Ref: 14c68996341
Ref: library/numbers numbers Rational numerator8996733
Ref: 2a508996733
Ref: library/numbers numbers Rational denominator8996825
Ref: 2a518996825
Ref: library/numbers numbers Integral8996921
Ref: 23ed8996921
Node: Notes for type implementers8997285
Ref: library/numbers notes-for-type-implementers8997416
Ref: 2a528997416
Node: Adding More Numeric ABCs8998266
Ref: library/numbers adding-more-numeric-abcs8998401
Ref: 2a538998401
Node: Implementing the arithmetic operations8998747
Ref: library/numbers id18998882
Ref: 2a548998882
Ref: library/numbers implementing-the-arithmetic-operations8998882
Ref: 231b8998882
Node: math — Mathematical functions9003553
Ref: library/math doc9003764
Ref: 2a559003764
Ref: library/math math-mathematical-functions9003764
Ref: 2a569003764
Ref: library/math module-math9003764
Ref: 929003764
Ref: library/math translation-repo9003764
Ref: 2a579003764
Ref: math — Mathematical functions-Footnote-19018402
Ref: math — Mathematical functions-Footnote-29018455
Ref: math — Mathematical functions-Footnote-39018508
Ref: math — Mathematical functions-Footnote-49018561
Node: Number-theoretic functions9018614
Ref: library/math number-theoretic-functions9018742
Ref: 2a689018742
Ref: library/math math comb9018813
Ref: 8e09018813
Ref: library/math math factorial9019404
Ref: b439019404
Ref: library/math math gcd9019603
Ref: b0e9019603
Ref: library/math math isqrt9020143
Ref: bfa9020143
Ref: library/math math lcm9020663
Ref: b0f9020663
Ref: library/math math perm9021065
Ref: 8e19021065
Node: Floating point arithmetic9021614
Ref: library/math floating-point-arithmetic9021788
Ref: 2a699021788
Ref: library/math math ceil9021857
Ref: 15c69021857
Ref: library/math math fabs9022098
Ref: 2a589022098
Ref: library/math math floor9022167
Ref: 15c59022167
Ref: library/math math fma9022399
Ref: 5159022399
Ref: library/math math fmod9023083
Ref: 24a49023083
Ref: library/math math modf9024127
Ref: 2a599024127
Ref: library/math math remainder9024550
Ref: d4c9024550
Ref: library/math math trunc9025578
Ref: 15c79025578
Node: Floating point manipulation functions9026346
Ref: library/math floating-point-manipulation-functions9026537
Ref: 2a6a9026537
Ref: library/math math copysign9026630
Ref: 15da9026630
Ref: library/math math frexp9026844
Ref: 2a5a9026844
Ref: library/math math isclose9027491
Ref: fb29027491
Ref: library/math math isfinite9029101
Ref: 13f39029101
Ref: library/math math isinf9029306
Ref: 15d89029306
Ref: library/math math isnan9029435
Ref: 15d99029435
Ref: library/math math ldexp9029553
Ref: 18289029553
Ref: library/math math nextafter9029688
Ref: 6c19029688
Ref: library/math math ulp9030361
Ref: b109030361
Ref: Floating point manipulation functions-Footnote-19031435
Node: Power exponential and logarithmic functions9031477
Ref: library/math power-exponential-and-logarithmic-functions9031674
Ref: 2a6b9031674
Ref: library/math math cbrt9031781
Ref: 8729031781
Ref: library/math math exp9031874
Ref: 151b9031874
Ref: library/math math exp29032092
Ref: 8719032092
Ref: library/math math expm19032192
Ref: 13f49032192
Ref: library/math math log9032808
Ref: 16c79032808
Ref: library/math math log1p9033043
Ref: 15df9033043
Ref: library/math math log29033206
Ref: 12e39033206
Ref: library/math math log109033552
Ref: 19309033552
Ref: library/math math pow9033684
Ref: 8739033684
Ref: library/math math sqrt9034556
Ref: bfb9034556
Ref: Power exponential and logarithmic functions-Footnote-19034658
Node: Summation and product functions9034717
Ref: library/math summation-and-product-functions9034895
Ref: 2a6c9034895
Ref: library/math math dist9034976
Ref: bf79034976
Ref: library/math math fsum9035307
Ref: 15db9035307
Ref: library/math math hypot9035981
Ref: bf89035981
Ref: library/math math prod9036747
Ref: bf99036747
Ref: library/math math sumprod9037125
Ref: 6c09037125
Ref: Summation and product functions-Footnote-19037593
Node: Angular conversion9037698
Ref: library/math angular-conversion9037856
Ref: 2a6d9037856
Ref: library/math math degrees9037911
Ref: 2a5b9037911
Ref: library/math math radians9037992
Ref: 2a5c9037992
Node: Trigonometric functions9038073
Ref: library/math trigonometric-functions9038220
Ref: 2a6e9038220
Ref: library/math math acos9038285
Ref: 2a5d9038285
Ref: library/math math asin9038412
Ref: 2a5e9038412
Ref: library/math math atan9038543
Ref: 2a5f9038543
Ref: library/math math atan29038677
Ref: 2a609038677
Ref: library/math math cos9039189
Ref: 16c69039189
Ref: library/math math sin9039257
Ref: 16c59039257
Ref: library/math math tan9039323
Ref: 2a619039323
Node: Hyperbolic functions9039392
Ref: library/math hyperbolic-functions9039538
Ref: 2a6f9039538
Ref: library/math math acosh9039710
Ref: 15dc9039710
Ref: library/math math asinh9039791
Ref: 15dd9039791
Ref: library/math math atanh9039870
Ref: 15de9039870
Ref: library/math math cosh9039952
Ref: 2a629039952
Ref: library/math math sinh9040024
Ref: 2a639040024
Ref: library/math math tanh9040094
Ref: 2a649040094
Ref: Hyperbolic functions-Footnote-19040203
Node: Special functions9040262
Ref: library/math special-functions9040397
Ref: 2a709040397
Ref: library/math math erf9040450
Ref: dd59040450
Ref: library/math math erfc9040872
Ref: dd69040872
Ref: library/math math gamma9041173
Ref: 13f59041173
Ref: library/math math lgamma9041274
Ref: 13f69041274
Ref: Special functions-Footnote-19041461
Ref: Special functions-Footnote-29041514
Ref: Special functions-Footnote-39041585
Ref: Special functions-Footnote-49041638
Ref: Special functions-Footnote-59041697
Node: Constants<2>9041750
Ref: library/math constants9041856
Ref: 2a719041856
Ref: library/math math pi9041895
Ref: 2a659041895
Ref: library/math math e9041990
Ref: 2a669041990
Ref: library/math math tau9042083
Ref: 2a679042083
Ref: library/math math inf9042463
Ref: e829042463
Ref: library/math math nan9042654
Ref: 8749042654
Ref: Constants<2>-Footnote-19044633
Ref: Constants<2>-Footnote-29044669
Ref: Constants<2>-Footnote-39044697
Node: cmath — Mathematical functions for complex numbers9044744
Ref: library/cmath doc9044975
Ref: 2a729044975
Ref: library/cmath cmath-mathematical-functions-for-complex-numbers9044975
Ref: 2a739044975
Ref: library/cmath module-cmath9044975
Ref: 199044975
Ref: library/cmath translation-repo9044975
Ref: 2a749044975
Node: Conversions to and from polar coordinates9053254
Ref: library/cmath conversions-to-and-from-polar-coordinates9053424
Ref: 2a8d9053424
Ref: library/cmath cmath phase9054229
Ref: 2a769054229
Ref: library/cmath cmath polar9054973
Ref: 2a779054973
Ref: library/cmath cmath rect9055228
Ref: 2a789055228
Node: Power and logarithmic functions9055409
Ref: library/cmath power-and-logarithmic-functions9055614
Ref: 2a8e9055614
Ref: library/cmath cmath exp9055695
Ref: 2a799055695
Ref: library/cmath cmath log9055816
Ref: 2a7a9055816
Ref: library/cmath cmath log109056060
Ref: 2a7b9056060
Ref: library/cmath cmath sqrt9056191
Ref: 2a759056191
Node: Trigonometric functions<2>9056315
Ref: library/cmath trigonometric-functions9056502
Ref: 2a8f9056502
Ref: library/cmath cmath acos9056567
Ref: 2a7c9056567
Ref: library/cmath cmath asin9056785
Ref: 2a7d9056785
Ref: library/cmath cmath atan9056908
Ref: 2a7e9056908
Ref: library/cmath cmath cos9057154
Ref: 2a7f9057154
Ref: library/cmath cmath sin9057215
Ref: 2a809057215
Ref: library/cmath cmath tan9057274
Ref: 2a819057274
Node: Hyperbolic functions<2>9057336
Ref: library/cmath hyperbolic-functions9057516
Ref: 2a909057516
Ref: library/cmath cmath acosh9057575
Ref: 2a829057575
Ref: library/cmath cmath asinh9057739
Ref: 2a839057739
Ref: library/cmath cmath atanh9057998
Ref: 2a849057998
Ref: library/cmath cmath cosh9058246
Ref: 2a859058246
Ref: library/cmath cmath sinh9058319
Ref: 2a869058319
Ref: library/cmath cmath tanh9058390
Ref: 2a879058390
Node: Classification functions9058464
Ref: library/cmath classification-functions9058630
Ref: 2a919058630
Ref: library/cmath cmath isfinite9058697
Ref: 2a889058697
Ref: library/cmath cmath isinf9058871
Ref: 2a899058871
Ref: library/cmath cmath isnan9059022
Ref: 2a8a9059022
Ref: library/cmath cmath isclose9059167
Ref: fb39059167
Ref: Classification functions-Footnote-19060802
Node: Constants<3>9060844
Ref: library/cmath constants9060978
Ref: 2a929060978
Ref: library/cmath cmath pi9061015
Ref: 2a8b9061015
Ref: library/cmath cmath e9061085
Ref: 2a8c9061085
Ref: library/cmath cmath tau9061153
Ref: e7f9061153
Ref: library/cmath cmath inf9061252
Ref: e809061252
Ref: library/cmath cmath infj9061376
Ref: e839061376
Ref: library/cmath cmath nan9061559
Ref: e819061559
Ref: library/cmath cmath nanj9061732
Ref: e849061732
Node: decimal — Decimal fixed-point and floating-point arithmetic9063149
Ref: library/decimal doc9063379
Ref: 2a939063379
Ref: library/decimal decimal-decimal-fixed-point-and-floating-point-arithmetic9063379
Ref: 2a949063379
Ref: library/decimal module-decimal9063379
Ref: 3a9063379
Ref: library/decimal translation-repo9063379
Ref: 2a959063379
Ref: decimal — Decimal fixed-point and floating-point arithmetic-Footnote-19068505
Ref: decimal — Decimal fixed-point and floating-point arithmetic-Footnote-29068572
Ref: decimal — Decimal fixed-point and floating-point arithmetic-Footnote-39068635
Node: Quick-start tutorial9068689
Ref: library/decimal decimal-tutorial9068831
Ref: 2aa59068831
Ref: library/decimal quick-start-tutorial9068831
Ref: 2aa69068831
Node: Decimal objects9076696
Ref: library/decimal decimal-decimal9076862
Ref: 2aa99076862
Ref: library/decimal decimal-objects9076862
Ref: 2aaa9076862
Ref: library/decimal decimal Decimal9076911
Ref: 1fe9076911
Ref: library/decimal decimal Decimal adjusted9082222
Ref: 2aab9082222
Ref: library/decimal decimal Decimal as_integer_ratio9082573
Ref: e949082573
Ref: library/decimal decimal Decimal as_tuple9083014
Ref: 2aac9083014
Ref: library/decimal decimal Decimal canonical9083172
Ref: 2aad9083172
Ref: library/decimal decimal Decimal compare9083411
Ref: 2aae9083411
Ref: library/decimal decimal Decimal compare_signal9083844
Ref: 2aaf9083844
Ref: library/decimal decimal Decimal compare_total9084156
Ref: 2ab09084156
Ref: library/decimal decimal Decimal compare_total_mag9085433
Ref: 2ab19085433
Ref: library/decimal decimal Decimal conjugate9086038
Ref: 2ab29086038
Ref: library/decimal decimal Decimal copy_abs9086171
Ref: 2ab39086171
Ref: library/decimal decimal Decimal copy_negate9086385
Ref: 2ab49086385
Ref: library/decimal decimal Decimal copy_sign9086596
Ref: 2ab59086596
Ref: library/decimal decimal Decimal exp9087133
Ref: 12b29087133
Ref: library/decimal decimal Decimal from_float9087567
Ref: 140c9087567
Ref: library/decimal decimal Decimal from_number9088710
Ref: 1fd9088710
Ref: library/decimal decimal Decimal fma9089258
Ref: 2ab69089258
Ref: library/decimal decimal Decimal is_canonical9089502
Ref: 2ab79089502
Ref: library/decimal decimal Decimal is_finite9089777
Ref: 2ab89089777
Ref: library/decimal decimal Decimal is_infinite9089952
Ref: 2ab99089952
Ref: library/decimal decimal Decimal is_nan9090119
Ref: 2aba9090119
Ref: library/decimal decimal Decimal is_normal9090271
Ref: 2abb9090271
Ref: library/decimal decimal Decimal is_qnan9090495
Ref: 2abc9090495
Ref: library/decimal decimal Decimal is_signed9090634
Ref: 2abd9090634
Ref: library/decimal decimal Decimal is_snan9090837
Ref: 2abe9090837
Ref: library/decimal decimal Decimal is_subnormal9090979
Ref: 2abf9090979
Ref: library/decimal decimal Decimal is_zero9091133
Ref: 2ac09091133
Ref: library/decimal decimal Decimal ln9091289
Ref: 12b39091289
Ref: library/decimal decimal Decimal log109091497
Ref: 2ac19091497
Ref: library/decimal decimal Decimal logb9091700
Ref: 2ac29091700
Ref: library/decimal decimal Decimal logical_and9092087
Ref: 2ac39092087
Ref: library/decimal decimal Decimal logical_invert9092352
Ref: 2ac59092352
Ref: library/decimal decimal Decimal logical_or9092531
Ref: 2ac69092531
Ref: library/decimal decimal Decimal logical_xor9092793
Ref: 2ac79092793
Ref: library/decimal decimal Decimal max9093061
Ref: 2ac89093061
Ref: library/decimal decimal Decimal max_mag9093365
Ref: 2ac99093365
Ref: library/decimal decimal Decimal min9093546
Ref: 2aca9093546
Ref: library/decimal decimal Decimal min_mag9093850
Ref: 2acb9093850
Ref: library/decimal decimal Decimal next_minus9094031
Ref: 2acc9094031
Ref: library/decimal decimal Decimal next_plus9094269
Ref: 2acd9094269
Ref: library/decimal decimal Decimal next_toward9094506
Ref: 2ace9094506
Ref: library/decimal decimal Decimal normalize9094873
Ref: 2acf9094873
Ref: library/decimal decimal Decimal number_class9095919
Ref: 2ad09095919
Ref: library/decimal decimal Decimal quantize9097089
Ref: 12b89097089
Ref: library/decimal decimal Decimal radix9098408
Ref: 2ad29098408
Ref: library/decimal decimal Decimal remainder_near9098625
Ref: 2ad39098625
Ref: library/decimal decimal Decimal rotate9099469
Ref: 2ad49099469
Ref: library/decimal decimal Decimal same_quantum9100142
Ref: 2ad59100142
Ref: library/decimal decimal Decimal scaleb9100554
Ref: 2ad69100554
Ref: library/decimal decimal Decimal shift9100805
Ref: 2ad79100805
Ref: library/decimal decimal Decimal sqrt9101411
Ref: 2ad89101411
Ref: library/decimal decimal Decimal to_eng_string9101518
Ref: 2ad99101518
Ref: library/decimal decimal Decimal to_integral9101994
Ref: 2ada9101994
Ref: library/decimal decimal Decimal to_integral_exact9102224
Ref: 2adc9102224
Ref: library/decimal decimal Decimal to_integral_value9102654
Ref: 2adb9102654
Node: Logical operands9105156
Ref: library/decimal logical-operands9105224
Ref: 2add9105224
Ref: library/decimal logical-operands-label9105224
Ref: 2ac49105224
Node: Context objects9105597
Ref: library/decimal context-objects9105755
Ref: 2ade9105755
Ref: library/decimal decimal-context9105755
Ref: 272a9105755
Ref: library/decimal decimal getcontext9106139
Ref: 191f9106139
Ref: library/decimal decimal setcontext9106232
Ref: 2aa79106232
Ref: library/decimal decimal localcontext9106469
Ref: 158e9106469
Ref: library/decimal decimal IEEEContext9107945
Ref: 1ff9107945
Ref: library/decimal decimal BasicContext9108371
Ref: 12ac9108371
Ref: library/decimal decimal ExtendedContext9108822
Ref: 12ad9108822
Ref: library/decimal decimal DefaultContext9109454
Ref: 12ab9109454
Ref: library/decimal decimal Context9110594
Ref: 12b79110594
Ref: library/decimal decimal Context prec9110981
Ref: 2ae09110981
Ref: library/decimal decimal Context rounding9111151
Ref: 2ae19111151
Ref: library/decimal decimal Context traps9111273
Ref: 12b69111273
Ref: library/decimal decimal Context flags9111299
Ref: 12b59111299
Ref: library/decimal decimal Context Emin9111453
Ref: 12af9111453
Ref: library/decimal decimal Context Emax9111478
Ref: 12ae9111478
Ref: library/decimal decimal Context capitals9111712
Ref: 2ae39111712
Ref: library/decimal decimal Context clamp9111947
Ref: 13a69111947
Ref: library/decimal decimal Context clear_flags9113742
Ref: 2aa89113742
Ref: library/decimal decimal Context clear_traps9113822
Ref: 2ae49113822
Ref: library/decimal decimal Context copy9113935
Ref: 2ae59113935
Ref: library/decimal decimal Context copy_decimal9114007
Ref: 2ae69114007
Ref: library/decimal decimal Context create_decimal9114101
Ref: 12b19114101
Ref: library/decimal decimal Context create_decimal_from_float9115212
Ref: 2ae79115212
Ref: library/decimal decimal Context Etiny9115981
Ref: 2ad19115981
Ref: library/decimal decimal Context Etop9116211
Ref: 2ae89116211
Ref: library/decimal decimal Context abs9116717
Ref: 2ae99116717
Ref: library/decimal decimal Context add9116792
Ref: 2aea9116792
Ref: library/decimal decimal Context canonical9116866
Ref: 150e9116866
Ref: library/decimal decimal Context compare9116949
Ref: 2aeb9116949
Ref: library/decimal decimal Context compare_signal9117030
Ref: 2aec9117030
Ref: library/decimal decimal Context compare_total9117137
Ref: 2aed9117137
Ref: library/decimal decimal Context compare_total_mag9117249
Ref: 2aee9117249
Ref: library/decimal decimal Context copy_abs9117390
Ref: 2aef9117390
Ref: library/decimal decimal Context copy_negate9117481
Ref: 2af09117481
Ref: library/decimal decimal Context copy_sign9117575
Ref: 2af19117575
Ref: library/decimal decimal Context divide9117657
Ref: 2af29117657
Ref: library/decimal decimal Context divide_int9117730
Ref: 2af39117730
Ref: library/decimal decimal Context divmod9117832
Ref: 2af49117832
Ref: library/decimal decimal Context exp9117952
Ref: 2af59117952
Ref: library/decimal decimal Context fma9118014
Ref: 2af69118014
Ref: library/decimal decimal Context is_canonical9118101
Ref: 150f9118101
Ref: library/decimal decimal Context is_finite9118221
Ref: 2af79118221
Ref: library/decimal decimal Context is_infinite9118335
Ref: 2af89118335
Ref: library/decimal decimal Context is_nan9118453
Ref: 2af99118453
Ref: library/decimal decimal Context is_normal9118582
Ref: 2afa9118582
Ref: library/decimal decimal Context is_qnan9118715
Ref: 2afb9118715
Ref: library/decimal decimal Context is_signed9118842
Ref: 2afc9118842
Ref: library/decimal decimal Context is_snan9118958
Ref: 2afd9118958
Ref: library/decimal decimal Context is_subnormal9119089
Ref: 2afe9119089
Ref: library/decimal decimal Context is_zero9119209
Ref: 2aff9119209
Ref: library/decimal decimal Context ln9119321
Ref: 2b009119321
Ref: library/decimal decimal Context log109119407
Ref: 2b019119407
Ref: library/decimal decimal Context logb9119487
Ref: 2b029119487
Ref: library/decimal decimal Context logical_and9119590
Ref: 2b039119590
Ref: library/decimal decimal Context logical_invert9119720
Ref: 2b049119720
Ref: library/decimal decimal Context logical_or9119801
Ref: 2b059119801
Ref: library/decimal decimal Context logical_xor9119929
Ref: 2b069119929
Ref: library/decimal decimal Context max9120059
Ref: 2b079120059
Ref: library/decimal decimal Context max_mag9120159
Ref: 2b089120159
Ref: library/decimal decimal Context min9120263
Ref: 2b099120263
Ref: library/decimal decimal Context min_mag9120363
Ref: 2b0a9120363
Ref: library/decimal decimal Context minus9120467
Ref: 2b0b9120467
Ref: library/decimal decimal Context multiply9120583
Ref: 2b0c9120583
Ref: library/decimal decimal Context next_minus9120666
Ref: 2b0d9120666
Ref: library/decimal decimal Context next_plus9120772
Ref: 2b0e9120772
Ref: library/decimal decimal Context next_toward9120877
Ref: 2b0f9120877
Ref: library/decimal decimal Context normalize9120989
Ref: 2b109120989
Ref: library/decimal decimal Context number_class9121069
Ref: 2b119121069
Ref: library/decimal decimal Context plus9121161
Ref: 2b129121161
Ref: library/decimal decimal Context power9121381
Ref: 2b139121381
Ref: library/decimal decimal Context quantize9123194
Ref: 2b149123194
Ref: library/decimal decimal Context radix9123320
Ref: 2b159123320
Ref: library/decimal decimal Context remainder9123398
Ref: 2b169123398
Ref: library/decimal decimal Context remainder_near9123596
Ref: 2b179123596
Ref: library/decimal decimal Context rotate9123819
Ref: 2b189123819
Ref: library/decimal decimal Context same_quantum9123907
Ref: 2b199123907
Ref: library/decimal decimal Context scaleb9124022
Ref: 2b1a9124022
Ref: library/decimal decimal Context shift9124143
Ref: 2b1b9124143
Ref: library/decimal decimal Context sqrt9124230
Ref: 2b1c9124230
Ref: library/decimal decimal Context subtract9124330
Ref: 2b1d9124330
Ref: library/decimal decimal Context to_eng_string9124421
Ref: 2b1e9124421
Ref: library/decimal decimal Context to_integral_exact9124788
Ref: 2b1f9124788
Ref: library/decimal decimal Context to_sci_string9124864
Ref: 2b209124864
Node: Constants<4>9124971
Ref: library/decimal constants9125128
Ref: 2b219125128
Ref: library/decimal decimal-rounding-modes9125128
Ref: 2b229125128
Ref: library/decimal decimal MAX_PREC9125630
Ref: 12a89125630
Ref: library/decimal decimal MAX_EMAX9125853
Ref: 12a99125853
Ref: library/decimal decimal MIN_EMIN9126076
Ref: 12aa9126076
Ref: library/decimal decimal MIN_ETINY9126301
Ref: 2b239126301
Ref: library/decimal decimal IEEE_CONTEXT_MAX_BITS9126508
Ref: 2adf9126508
Ref: library/decimal decimal HAVE_THREADS9126643
Ref: 12a69126643
Ref: library/decimal decimal HAVE_CONTEXTVAR9126799
Ref: 21529126799
Node: Rounding modes9127162
Ref: library/decimal rounding-modes9127311
Ref: 2ae29127311
Ref: library/decimal decimal ROUND_CEILING9127358
Ref: 2a969127358
Ref: library/decimal decimal ROUND_DOWN9127427
Ref: 2a979127427
Ref: library/decimal decimal ROUND_FLOOR9127483
Ref: 2a989127483
Ref: library/decimal decimal ROUND_HALF_DOWN9127551
Ref: 2a999127551
Ref: library/decimal decimal ROUND_HALF_EVEN9127639
Ref: 2a9a9127639
Ref: library/decimal decimal ROUND_HALF_UP9127738
Ref: 2a9b9127738
Ref: library/decimal decimal ROUND_UP9127826
Ref: 2a9c9127826
Ref: library/decimal decimal ROUND_05UP9127882
Ref: 2a9d9127882
Node: Signals9128040
Ref: library/decimal decimal-signals9128197
Ref: 2b249128197
Ref: library/decimal signals9128197
Ref: 2b259128197
Ref: library/decimal decimal Clamped9128914
Ref: 2a9e9128914
Ref: library/decimal decimal DecimalException9129228
Ref: 2b269129228
Ref: library/decimal decimal DivisionByZero9129353
Ref: 2a9f9129353
Ref: library/decimal decimal Inexact9129692
Ref: 2aa09129692
Ref: library/decimal decimal InvalidOperation9129968
Ref: 12b09129968
Ref: library/decimal decimal Overflow9130410
Ref: 2aa39130410
Ref: library/decimal decimal Rounded9130834
Ref: 2aa19130834
Ref: library/decimal decimal Subnormal9131173
Ref: 2aa29131173
Ref: library/decimal decimal Underflow9131403
Ref: 2aa49131403
Ref: library/decimal decimal FloatOperation9131629
Ref: 12a59131629
Node: Floating-point notes9132906
Ref: library/decimal decimal-notes9133069
Ref: 2b279133069
Ref: library/decimal floating-point-notes9133069
Ref: 2b289133069
Node: Mitigating round-off error with increased precision9133213
Ref: library/decimal mitigating-round-off-error-with-increased-precision9133344
Ref: 2b299133344
Node: Special values9135033
Ref: library/decimal special-values9135164
Ref: 2b2a9135164
Node: Working with threads9138299
Ref: library/decimal decimal-threads9138462
Ref: 2b2b9138462
Ref: library/decimal working-with-threads9138462
Ref: 2b2c9138462
Node: Recipes9140276
Ref: library/decimal decimal-recipes9140430
Ref: 2b2d9140430
Ref: library/decimal recipes9140430
Ref: 2b2e9140430
Node: Decimal FAQ9145275
Ref: library/decimal decimal-faq9145400
Ref: 2b2f9145400
Ref: library/decimal id19145400
Ref: 2b309145400
Ref: Decimal FAQ-Footnote-19154410
Ref: Decimal FAQ-Footnote-29154477
Ref: Decimal FAQ-Footnote-39154508
Ref: Decimal FAQ-Footnote-49154566
Ref: Decimal FAQ-Footnote-59154669
Node: fractions — Rational numbers9154784
Ref: library/fractions doc9155003
Ref: 2b319155003
Ref: library/fractions fractions-rational-numbers9155003
Ref: 2b329155003
Ref: library/fractions module-fractions9155003
Ref: 619155003
Ref: library/fractions translation-repo9155003
Ref: 2b339155003
Ref: library/fractions fractions Fraction9155383
Ref: 2139155383
Ref: library/fractions fractions Fraction numerator9159875
Ref: 2b359159875
Ref: library/fractions fractions Fraction denominator9159959
Ref: 2b369159959
Ref: library/fractions fractions Fraction as_integer_ratio9160086
Ref: 2b379160086
Ref: library/fractions fractions Fraction is_integer9160329
Ref: 2b389160329
Ref: library/fractions fractions Fraction from_float9160455
Ref: 140d9160455
Ref: library/fractions fractions Fraction from_decimal9160906
Ref: 140e9160906
Ref: library/fractions fractions Fraction from_number9161279
Ref: 2149161279
Ref: library/fractions fractions Fraction limit_denominator9161641
Ref: 2b349161641
Ref: library/fractions fractions Fraction __floor__9162515
Ref: 1adf9162515
Ref: library/fractions fractions Fraction __ceil__9162816
Ref: 1ade9162816
Ref: library/fractions fractions Fraction __round__9163007
Ref: 1add9163007
Ref: library/fractions fractions Fraction __format__9163478
Ref: 2b399163478
Ref: fractions — Rational numbers-Footnote-19165807
Ref: fractions — Rational numbers-Footnote-29165876
Node: random — Generate pseudo-random numbers9165918
Ref: library/random doc9166124
Ref: 2b3a9166124
Ref: library/random module-random9166124
Ref: bd9166124
Ref: library/random random-generate-pseudo-random-numbers9166124
Ref: 2b3b9166124
Ref: library/random translation-repo9166124
Ref: 2b3c9166124
Ref: random — Generate pseudo-random numbers-Footnote-19169437
Ref: random — Generate pseudo-random numbers-Footnote-29169503
Node: Bookkeeping functions9169593
Ref: library/random bookkeeping-functions9169720
Ref: 2b3e9169720
Ref: library/random random seed9169781
Ref: 147b9169781
Ref: library/random random getstate9170890
Ref: 2b3f9170890
Ref: library/random random setstate9171088
Ref: 2b409171088
Node: Functions for bytes9171366
Ref: library/random functions-for-bytes9171524
Ref: 2b419171524
Ref: library/random random randbytes9171581
Ref: 180e9171581
Node: Functions for integers9171801
Ref: library/random functions-for-integers9171961
Ref: 2b439171961
Ref: library/random random randrange9172024
Ref: a6d9172024
Ref: library/random random randint9173093
Ref: 14379173093
Ref: library/random random getrandbits9173234
Ref: 120f9173234
Node: Functions for sequences9173682
Ref: library/random functions-for-sequences9173845
Ref: 2b449173845
Ref: library/random random choice9173910
Ref: 14389173910
Ref: library/random random choices9174066
Ref: ec39174066
Ref: library/random random shuffle9176124
Ref: 94f9176124
Ref: library/random random sample9176795
Ref: 94e9176795
Node: Discrete distributions9178342
Ref: library/random discrete-distributions9178508
Ref: 2b459178508
Ref: library/random random binomialvariate9178630
Ref: 6d89178630
Ref: Discrete distributions-Footnote-19179192
Node: Real-valued distributions9179256
Ref: library/random id19179420
Ref: 2b469179420
Ref: library/random real-valued-distributions9179420
Ref: 2b479179420
Ref: library/random random random9179759
Ref: 9509179759
Ref: library/random random uniform9179881
Ref: 2b489179881
Ref: library/random random triangular9180222
Ref: 2b499180222
Ref: library/random random betavariate9180579
Ref: 2b4a9180579
Ref: library/random random expovariate9180767
Ref: 6d99180767
Ref: library/random random gammavariate9181225
Ref: 2b4b9181225
Ref: library/random random gauss9181738
Ref: 1bc09181738
Ref: library/random random lognormvariate9182492
Ref: 2b4c9182492
Ref: library/random random normalvariate9182791
Ref: 1bc19182791
Ref: library/random random vonmisesvariate9183023
Ref: 2b4d9183023
Ref: library/random random paretovariate9183365
Ref: 2b4e9183365
Ref: library/random random weibullvariate9183469
Ref: 2b4f9183469
Node: Alternative Generator9183620
Ref: library/random alternative-generator9183786
Ref: 2b509183786
Ref: library/random random Random9183847
Ref: 1c449183847
Ref: library/random random Random seed9184359
Ref: 1d529184359
Ref: library/random random Random getstate9184532
Ref: 2b519184532
Ref: library/random random Random setstate9184696
Ref: 2b529184696
Ref: library/random random Random random9184865
Ref: 2b539184865
Ref: library/random random Random getrandbits9185113
Ref: 2b549185113
Ref: library/random random Random randbytes9185284
Ref: b259185284
Ref: library/random random SystemRandom9185451
Ref: 2b3d9185451
Node: Notes on Reproducibility9185950
Ref: library/random notes-on-reproducibility9186102
Ref: 2b559186102
Node: Examples<4>9186811
Ref: library/random examples9186952
Ref: 2b569186952
Ref: library/random random-examples9186952
Ref: 13e49186952
Ref: Examples<4>-Footnote-19192205
Ref: Examples<4>-Footnote-29192270
Ref: Examples<4>-Footnote-39192351
Ref: Examples<4>-Footnote-49192397
Ref: Examples<4>-Footnote-59192449
Ref: Examples<4>-Footnote-69192504
Ref: Examples<4>-Footnote-79192572
Ref: Examples<4>-Footnote-89192608
Ref: Examples<4>-Footnote-99192678
Node: Recipes<2>9192714
Ref: library/random recipes9192852
Ref: 2b579192852
Ref: Recipes<2>-Footnote-19196598
Node: Command-line usage<2>9196666
Ref: library/random command-line-usage9196813
Ref: 2b589196813
Ref: library/random random-cli9196813
Ref: 47f9196813
Ref: library/random cmdoption-random-h9197074
Ref: 2b599197074
Ref: library/random cmdoption-random-help9197074
Ref: 2b5a9197074
Ref: library/random cmdoption-random-c9197136
Ref: 2b5b9197136
Ref: library/random cmdoption-random-choice9197171
Ref: 2b5c9197171
Ref: library/random cmdoption-random-i9197270
Ref: 2b5d9197270
Ref: library/random cmdoption-random-integer9197289
Ref: 2b5e9197289
Ref: library/random cmdoption-random-f9197406
Ref: 2b5f9197406
Ref: library/random cmdoption-random-float9197425
Ref: 2b609197425
Node: Command-line example9197754
Ref: library/random command-line-example9197882
Ref: 2b619197882
Ref: library/random random-cli-example9197882
Ref: 2b629197882
Node: statistics — Mathematical statistics functions9198711
Ref: library/statistics doc9198878
Ref: 2b639198878
Ref: library/statistics module-statistics9198878
Ref: d79198878
Ref: library/statistics statistics-mathematical-statistics-functions9198878
Ref: 2b649198878
Ref: library/statistics translation-repo9198878
Ref: 2b659198878
Ref: statistics — Mathematical statistics functions-Footnote-19201430
Ref: statistics — Mathematical statistics functions-Footnote-29201500
Ref: statistics — Mathematical statistics functions-Footnote-39201526
Node: Averages and measures of central location9201553
Ref: library/statistics averages-and-measures-of-central-location9201706
Ref: 2b669201706
Node: Measures of spread9203529
Ref: library/statistics measures-of-spread9203734
Ref: 2b6b9203734
Node: Statistics for relations between two inputs9204360
Ref: library/statistics statistics-for-relations-between-two-inputs9204540
Ref: 2b6d9204540
Node: Function details9205108
Ref: library/statistics function-details9205283
Ref: 2b6e9205283
Ref: library/statistics statistics mean9205485
Ref: 8e29205485
Ref: library/statistics statistics fmean9207032
Ref: c2b9207032
Ref: library/statistics statistics geometric_mean9207988
Ref: c2c9207988
Ref: library/statistics statistics harmonic_mean9208677
Ref: edf9208677
Ref: library/statistics statistics kde9210241
Ref: 5539210241
Ref: library/statistics statistics kde_random9212125
Ref: 5549212125
Ref: library/statistics statistics median9213180
Ref: 2b679213180
Ref: library/statistics statistics median_low9214173
Ref: 2b689214173
Ref: library/statistics statistics median_high9214814
Ref: 2b699214814
Ref: library/statistics statistics median_grouped9215452
Ref: 2b6a9215452
Ref: library/statistics statistics mode9217363
Ref: c879217363
Ref: library/statistics statistics multimode9218887
Ref: c2d9218887
Ref: library/statistics statistics pstdev9219308
Ref: 17989219308
Ref: library/statistics statistics pvariance9219608
Ref: 2b6c9219608
Ref: library/statistics statistics stdev9221883
Ref: 8e49221883
Ref: library/statistics statistics variance9222174
Ref: 8e39222174
Ref: library/statistics statistics quantiles9224460
Ref: c2e9224460
Ref: library/statistics statistics covariance9227445
Ref: a339227445
Ref: library/statistics statistics correlation9228066
Ref: 6e49228066
Ref: library/statistics statistics linear_regression9230161
Ref: a349230161
Ref: Function details-Footnote-19232751
Ref: Function details-Footnote-29232797
Ref: Function details-Footnote-39232852
Ref: Function details-Footnote-49232948
Ref: Function details-Footnote-59233006
Ref: Function details-Footnote-69233078
Ref: Function details-Footnote-79233129
Ref: Function details-Footnote-89233199
Ref: Function details-Footnote-99233280
Ref: Function details-Footnote-109233352
Ref: Function details-Footnote-119233416
Node: Exceptions<4>9233474
Ref: library/statistics exceptions9233624
Ref: 2b709233624
Ref: library/statistics statistics StatisticsError9233695
Ref: 2b6f9233695
Node: NormalDist objects9233819
Ref: library/statistics normaldist-objects9233976
Ref: 2b719233976
Ref: library/statistics statistics NormalDist9234364
Ref: c2f9234364
Ref: library/statistics statistics NormalDist mean9234630
Ref: 2b729234630
Ref: library/statistics statistics NormalDist median9234751
Ref: 2b739234751
Ref: library/statistics statistics NormalDist mode9234865
Ref: 2b749234865
Ref: library/statistics statistics NormalDist stdev9234965
Ref: 2b759234965
Ref: library/statistics statistics NormalDist variance9235090
Ref: 2b769235090
Ref: library/statistics statistics NormalDist from_samples9235256
Ref: 2b779235256
Ref: library/statistics statistics NormalDist samples9235864
Ref: 2b789235864
Ref: library/statistics statistics NormalDist pdf9236482
Ref: 2b799236482
Ref: library/statistics statistics NormalDist cdf9237081
Ref: 183a9237081
Ref: library/statistics statistics NormalDist inv_cdf9237324
Ref: 2b7a9237324
Ref: library/statistics statistics NormalDist overlap9237763
Ref: 2b7b9237763
Ref: library/statistics statistics NormalDist quantiles9238019
Ref: 2b7c9238019
Ref: library/statistics statistics NormalDist zscore9238474
Ref: 2b7d9238474
Ref: NormalDist objects-Footnote-19239899
Ref: NormalDist objects-Footnote-29239963
Ref: NormalDist objects-Footnote-39240023
Ref: NormalDist objects-Footnote-49240077
Ref: NormalDist objects-Footnote-59240134
Ref: NormalDist objects-Footnote-69240188
Ref: NormalDist objects-Footnote-79240233
Ref: NormalDist objects-Footnote-89240289
Ref: NormalDist objects-Footnote-99240346
Ref: NormalDist objects-Footnote-109240393
Ref: NormalDist objects-Footnote-119240461
Ref: NormalDist objects-Footnote-129240533
Ref: NormalDist objects-Footnote-139240590
Ref: NormalDist objects-Footnote-149240725
Ref: NormalDist objects-Footnote-159240772
Ref: NormalDist objects-Footnote-169240850
Node: Examples and Recipes<2>9240935
Ref: library/statistics examples-and-recipes9241070
Ref: 2b7e9241070
Node: Classic probability problems9241282
Ref: library/statistics classic-probability-problems9241413
Ref: 2b7f9241413
Ref: Classic probability problems-Footnote-19242240
Ref: Classic probability problems-Footnote-29242311
Ref: Classic probability problems-Footnote-39242358
Node: Monte Carlo inputs for simulations9242403
Ref: library/statistics monte-carlo-inputs-for-simulations9242579
Ref: 2b809242579
Ref: Monte Carlo inputs for simulations-Footnote-19243269
Node: Approximating binomial distributions9243326
Ref: library/statistics approximating-binomial-distributions9243499
Ref: 2b819243499
Ref: Approximating binomial distributions-Footnote-19244931
Node: Naive bayesian classifier9244995
Ref: library/statistics naive-bayesian-classifier9245125
Ref: 2b829245125
Ref: Naive bayesian classifier-Footnote-19247020
Ref: Naive bayesian classifier-Footnote-29247104
Ref: Naive bayesian classifier-Footnote-39247160
Node: Functional Programming Modules9247230
Ref: library/functional doc9247399
Ref: 2b839247399
Ref: library/functional functional-programming-modules9247399
Ref: 2b849247399
Ref: library/functional translation-repo9247399
Ref: 2b859247399
Node: itertools — Functions creating iterators for efficient looping9247882
Ref: library/itertools doc9248093
Ref: 2b869248093
Ref: library/itertools itertools-functions-creating-iterators-for-efficient-looping9248093
Ref: 2b879248093
Ref: library/itertools module-itertools9248093
Ref: 859248093
Node: Itertool Functions9259241
Ref: library/itertools itertool-functions9259386
Ref: 2b8e9259386
Ref: library/itertools itertools-functions9259386
Ref: 2b8f9259386
Ref: library/itertools itertools accumulate9259626
Ref: bf29259626
Ref: library/itertools itertools batched9262064
Ref: 5129262064
Ref: library/itertools itertools chain9263400
Ref: 25bc9263400
Ref: library/itertools itertools chain from_iterable9263879
Ref: 2b899263879
Ref: library/itertools itertools combinations9264289
Ref: 15199264289
Ref: library/itertools itertools combinations_with_replacement9265901
Ref: 14899265901
Ref: library/itertools itertools compress9267485
Ref: 148a9267485
Ref: library/itertools itertools count9267982
Ref: 148b9267982
Ref: library/itertools itertools cycle9268804
Ref: 2b889268804
Ref: library/itertools itertools dropwhile9269507
Ref: 2b8a9269507
Ref: library/itertools itertools filterfalse9270214
Ref: 25aa9270214
Ref: library/itertools itertools groupby9270799
Ref: 2b8b9270799
Ref: library/itertools itertools islice9273423
Ref: d459273423
Ref: library/itertools itertools pairwise9275191
Ref: a189275191
Ref: library/itertools itertools permutations9275808
Ref: 1cc59275808
Ref: library/itertools itertools product9277877
Ref: 151a9277877
Ref: library/itertools itertools repeat9279583
Ref: 18419279583
Ref: library/itertools itertools starmap9280269
Ref: 12ec9280269
Ref: library/itertools itertools takewhile9280915
Ref: 2b8c9280915
Ref: library/itertools itertools tee9281718
Ref: 2b8d9281718
Ref: library/itertools itertools zip_longest9284451
Ref: 14a69284451
Ref: Itertool Functions-Footnote-19285960
Ref: Itertool Functions-Footnote-29286034
Ref: Itertool Functions-Footnote-39286089
Ref: Itertool Functions-Footnote-49286145
Node: Itertools Recipes9286243
Ref: library/itertools id19286388
Ref: 2b919286388
Ref: library/itertools itertools-recipes9286388
Ref: 14669286388
Ref: Itertools Recipes-Footnote-19300977
Ref: Itertools Recipes-Footnote-29301026
Node: functools — Higher-order functions and operations on callable objects9301097
Ref: library/functools doc9301361
Ref: 2b929301361
Ref: library/functools functools-higher-order-functions-and-operations-on-callable-objects9301361
Ref: 2b939301361
Ref: library/functools module-functools9301361
Ref: 639301361
Ref: library/functools translation-repo9301361
Ref: 2b949301361
Ref: library/functools functools cache9301904
Ref: 17b09301904
Ref: library/functools functools cached_property9303131
Ref: 7649303131
Ref: library/functools functools cmp_to_key9306444
Ref: 13e29306444
Ref: library/functools functools lru_cache9307498
Ref: be49307498
Ref: library/functools functools lru_cache cache_info9310027
Ref: 2b969310027
Ref: library/functools functools lru_cache cache_clear9310292
Ref: 2b979310292
Ref: library/functools functools total_ordering9313041
Ref: 11449313041
Ref: library/functools functools Placeholder9315287
Ref: 2169315287
Ref: library/functools functools partial9315514
Ref: 2179315514
Ref: library/functools functools partialmethod9318590
Ref: 2189318590
Ref: library/functools functools reduce9320335
Ref: 21a9320335
Ref: library/functools functools singledispatch9321676
Ref: 84c9321676
Ref: library/functools functools singledispatch register9322280
Ref: 2b989322280
Ref: library/functools functools singledispatchmethod9328119
Ref: be59328119
Ref: library/functools functools update_wrapper9329838
Ref: 12249329838
Ref: library/functools functools wraps9332442
Ref: 115f9332442
Ref: functools — Higher-order functions and operations on callable objects-Footnote-19333741
Ref: functools — Higher-order functions and operations on callable objects-Footnote-29333810
Ref: functools — Higher-order functions and operations on callable objects-Footnote-39333860
Ref: functools — Higher-order functions and operations on callable objects-Footnote-49333902
Ref: functools — Higher-order functions and operations on callable objects-Footnote-59333994
Ref: functools — Higher-order functions and operations on callable objects-Footnote-69334049
Ref: functools — Higher-order functions and operations on callable objects-Footnote-79334107
Node: partial Objects9334172
Ref: library/functools id19334295
Ref: 2b9a9334295
Ref: library/functools partial-objects9334295
Ref: 2199334295
Ref: library/functools functools partial func9334476
Ref: 2b9b9334476
Ref: library/functools functools partial args9334665
Ref: 2b9c9334665
Ref: library/functools functools partial keywords9334837
Ref: 2b9d9334837
Node: operator — Standard operators as functions9335256
Ref: library/operator doc9335447
Ref: 2b9e9335447
Ref: library/operator module-operator9335447
Ref: a39335447
Ref: library/operator operator-standard-operators-as-functions9335447
Ref: 2b9f9335447
Ref: library/operator translation-repo9335447
Ref: 2ba09335447
Ref: library/operator operator lt9336380
Ref: 2ba19336380
Ref: library/operator operator le9336413
Ref: 2ba29336413
Ref: library/operator operator eq9336446
Ref: 2ba39336446
Ref: library/operator operator ne9336479
Ref: 2ba49336479
Ref: library/operator operator ge9336512
Ref: 2ba59336512
Ref: library/operator operator gt9336545
Ref: 2ba69336545
Ref: library/operator operator __lt__9336578
Ref: 2ba79336578
Ref: library/operator operator __le__9336615
Ref: 2ba89336615
Ref: library/operator operator __eq__9336652
Ref: 2ba99336652
Ref: library/operator operator __ne__9336689
Ref: 2baa9336689
Ref: library/operator operator __ge__9336726
Ref: 2bab9336726
Ref: library/operator operator __gt__9336763
Ref: 2bac9336763
Ref: library/operator operator not_9337501
Ref: 2bad9337501
Ref: library/operator operator __not__9337535
Ref: 2bae9337535
Ref: library/operator operator truth9337851
Ref: 2baf9337851
Ref: library/operator operator is_9338041
Ref: 2bb09338041
Ref: library/operator operator is_not9338127
Ref: 2bb19338127
Ref: library/operator operator is_none9338220
Ref: 2559338220
Ref: library/operator operator is_not_none9338339
Ref: 2569338339
Ref: library/operator operator abs9338530
Ref: 2bb29338530
Ref: library/operator operator __abs__9338563
Ref: 2bb39338563
Ref: library/operator operator add9338643
Ref: 2bb49338643
Ref: library/operator operator __add__9338677
Ref: 2bb59338677
Ref: library/operator operator and_9338767
Ref: 2bb69338767
Ref: library/operator operator __and__9338802
Ref: 2bb79338802
Ref: library/operator operator floordiv9338886
Ref: 2bb89338886
Ref: library/operator operator __floordiv__9338925
Ref: 2bb99338925
Ref: library/operator operator index9338996
Ref: 1cba9338996
Ref: library/operator operator __index__9339029
Ref: 2bba9339029
Ref: library/operator operator inv9339320
Ref: 2bbb9339320
Ref: library/operator operator invert9339353
Ref: 2bbc9339353
Ref: library/operator operator __inv__9339389
Ref: 2bbd9339389
Ref: library/operator operator __invert__9339426
Ref: 2bbe9339426
Ref: library/operator operator lshift9339561
Ref: 2bbf9339561
Ref: library/operator operator __lshift__9339598
Ref: 2bc09339598
Ref: library/operator operator mod9339678
Ref: 2bc19339678
Ref: library/operator operator __mod__9339712
Ref: 2bc29339712
Ref: library/operator operator mul9339777
Ref: 2b909339777
Ref: library/operator operator __mul__9339811
Ref: 2bc39339811
Ref: library/operator operator matmul9339901
Ref: 10379339901
Ref: library/operator operator __matmul__9339938
Ref: 2bc49339938
Ref: library/operator operator neg9340034
Ref: 2bc59340034
Ref: library/operator operator __neg__9340067
Ref: 2bc69340067
Ref: library/operator operator or_9340146
Ref: 2bc79340146
Ref: library/operator operator __or__9340180
Ref: 2bc89340180
Ref: library/operator operator pos9340262
Ref: 2bc99340262
Ref: library/operator operator __pos__9340295
Ref: 2bca9340295
Ref: library/operator operator pow9340375
Ref: 2bcb9340375
Ref: library/operator operator __pow__9340409
Ref: 2bcc9340409
Ref: library/operator operator rshift9340500
Ref: 2bcd9340500
Ref: library/operator operator __rshift__9340537
Ref: 2bce9340537
Ref: library/operator operator sub9340618
Ref: 2bcf9340618
Ref: library/operator operator __sub__9340652
Ref: 2bd09340652
Ref: library/operator operator truediv9340717
Ref: 2bd19340717
Ref: library/operator operator __truediv__9340755
Ref: 2bd29340755
Ref: library/operator operator xor9340902
Ref: 2bd39340902
Ref: library/operator operator __xor__9340936
Ref: 2bd49340936
Ref: library/operator operator concat9341109
Ref: 2bd59341109
Ref: library/operator operator __concat__9341146
Ref: 2bd69341146
Ref: library/operator operator contains9341240
Ref: ad99341240
Ref: library/operator operator __contains__9341279
Ref: 2bd79341279
Ref: library/operator operator countOf9341408
Ref: adb9341408
Ref: library/operator operator delitem9341501
Ref: 2bd89341501
Ref: library/operator operator __delitem__9341539
Ref: 2bd99341539
Ref: library/operator operator getitem9341626
Ref: 2bda9341626
Ref: library/operator operator __getitem__9341664
Ref: 2bdb9341664
Ref: library/operator operator indexOf9341751
Ref: ada9341751
Ref: library/operator operator setitem9341855
Ref: 2bdc9341855
Ref: library/operator operator __setitem__9341896
Ref: 2bdd9341896
Ref: library/operator operator length_hint9341990
Ref: 116f9341990
Ref: library/operator operator call9342327
Ref: 1c0a9342327
Ref: library/operator operator __call__9342381
Ref: 2bde9342381
Ref: library/operator operator attrgetter9342797
Ref: 10359342797
Ref: library/operator operator itemgetter9344098
Ref: c599344098
Ref: library/operator operator methodcaller9345871
Ref: 10369345871
Ref: operator — Standard operators as functions-Footnote-19346670
Node: Mapping Operators to Functions9346738
Ref: library/operator mapping-operators-to-functions9346876
Ref: 2bdf9346876
Ref: library/operator operator-map9346876
Ref: 2be09346876
Node: In-place Operators9354698
Ref: library/operator in-place-operators9354836
Ref: 2be19354836
Ref: library/operator operator iadd9356142
Ref: 2be39356142
Ref: library/operator operator __iadd__9356177
Ref: 2be49356177
Ref: library/operator operator iand9356275
Ref: 2be59356275
Ref: library/operator operator __iand__9356310
Ref: 2be69356310
Ref: library/operator operator iconcat9356408
Ref: 2be79356408
Ref: library/operator operator __iconcat__9356446
Ref: 2be89356446
Ref: library/operator operator ifloordiv9356581
Ref: 2be99356581
Ref: library/operator operator __ifloordiv__9356621
Ref: 2bea9356621
Ref: library/operator operator ilshift9356730
Ref: 2beb9356730
Ref: library/operator operator __ilshift__9356768
Ref: 2bec9356768
Ref: library/operator operator imod9356873
Ref: 2bed9356873
Ref: library/operator operator __imod__9356908
Ref: 2bee9356908
Ref: library/operator operator imul9357006
Ref: 2bef9357006
Ref: library/operator operator __imul__9357041
Ref: 2bf09357041
Ref: library/operator operator imatmul9357139
Ref: 10389357139
Ref: library/operator operator __imatmul__9357177
Ref: 2bf19357177
Ref: library/operator operator ior9357309
Ref: 2bf29357309
Ref: library/operator operator __ior__9357343
Ref: 2bf39357343
Ref: library/operator operator ipow9357439
Ref: 2bf49357439
Ref: library/operator operator __ipow__9357474
Ref: 2bf59357474
Ref: library/operator operator irshift9357573
Ref: 2bf69357573
Ref: library/operator operator __irshift__9357611
Ref: 2bf79357611
Ref: library/operator operator isub9357716
Ref: 2bf89357716
Ref: library/operator operator __isub__9357751
Ref: 2bf99357751
Ref: library/operator operator itruediv9357849
Ref: 2bfa9357849
Ref: library/operator operator __itruediv__9357888
Ref: 2bfb9357888
Ref: library/operator operator ixor9357994
Ref: 2bfc9357994
Ref: library/operator operator __ixor__9358029
Ref: 2bfd9358029
Node: File and Directory Access9358127
Ref: library/filesys doc9358280
Ref: 2bfe9358280
Ref: library/filesys file-and-directory-access9358280
Ref: 2bff9358280
Ref: library/filesys filesys9358280
Ref: 2c009358280
Ref: library/filesys translation-repo9358280
Ref: 2c019358280
Node: pathlib — Object-oriented filesystem paths9359117
Ref: library/pathlib doc9359273
Ref: 2c029359273
Ref: library/pathlib module-pathlib9359273
Ref: a89359273
Ref: library/pathlib pathlib-object-oriented-filesystem-paths9359273
Ref: 2c039359273
Ref: pathlib — Object-oriented filesystem paths-Footnote-19361515
Ref: pathlib — Object-oriented filesystem paths-Footnote-29361580
Node: Basic use<2>9361622
Ref: library/pathlib basic-use9361737
Ref: 2c079361737
Node: Exceptions<5>9362683
Ref: library/pathlib exceptions9362817
Ref: 2c089362817
Ref: library/pathlib pathlib UnsupportedOperation9362858
Ref: 5349362858
Node: Pure paths9363072
Ref: library/pathlib id19363208
Ref: 2c099363208
Ref: library/pathlib pure-paths9363208
Ref: 2c049363208
Ref: library/pathlib pathlib PurePath9363423
Ref: 6ce9363423
Ref: library/pathlib pathlib PurePosixPath9365793
Ref: 2c0a9365793
Ref: library/pathlib pathlib PureWindowsPath9366098
Ref: 1a5d9366098
Ref: Pure paths-Footnote-19366847
Node: General properties9366906
Ref: library/pathlib general-properties9366989
Ref: 2c0b9366989
Node: Operators9367852
Ref: library/pathlib operators9367970
Ref: 2c0c9367970
Node: Accessing individual parts9369513
Ref: library/pathlib accessing-individual-parts9369635
Ref: 2c0d9369635
Ref: library/pathlib pathlib PurePath parts9369796
Ref: 2c0e9369796
Node: Methods and properties9370199
Ref: library/pathlib methods-and-properties9370303
Ref: 2c0f9370303
Ref: library/pathlib pathlib PurePath parser9370426
Ref: 5379370426
Ref: library/pathlib pathlib PurePath drive9370635
Ref: 2c109370635
Ref: library/pathlib pathlib PurePath root9371058
Ref: 2c119371058
Ref: library/pathlib pathlib PurePath anchor9372103
Ref: 2c129372103
Ref: library/pathlib pathlib PurePath parents9372470
Ref: a239372470
Ref: library/pathlib pathlib PurePath parent9372961
Ref: 1a859372961
Ref: library/pathlib pathlib PurePath name9373781
Ref: 2c139373781
Ref: library/pathlib pathlib PurePath suffix9374174
Ref: 193f9374174
Ref: library/pathlib pathlib PurePath suffixes9374632
Ref: 19409374632
Ref: library/pathlib pathlib PurePath stem9375068
Ref: 2c149375068
Ref: library/pathlib pathlib PurePath as_posix9375367
Ref: 2c159375367
Ref: library/pathlib pathlib PurePath is_absolute9375632
Ref: 1a849375632
Ref: library/pathlib pathlib PurePath is_relative_to9376224
Ref: 2fe9376224
Ref: library/pathlib pathlib PurePath is_reserved9376929
Ref: 32a9376929
Ref: library/pathlib pathlib PurePath joinpath9377523
Ref: 2c169377523
Ref: library/pathlib pathlib PurePath full_match9378110
Ref: 5369378110
Ref: library/pathlib pathlib PurePath match9379029
Ref: 6d49379029
Ref: library/pathlib pathlib PurePath relative_to9379954
Ref: 2fd9379954
Ref: library/pathlib pathlib PurePath with_name9382165
Ref: 1a509382165
Ref: library/pathlib pathlib PurePath with_stem9382879
Ref: 19c49382879
Ref: library/pathlib pathlib PurePath with_suffix9383897
Ref: 193e9383897
Ref: library/pathlib pathlib PurePath with_segments9384755
Ref: 6cf9384755
Ref: Methods and properties-Footnote-19385691
Node: Concrete paths9385783
Ref: library/pathlib concrete-paths9385922
Ref: 2c059385922
Ref: library/pathlib id29385922
Ref: 2c189385922
Ref: library/pathlib pathlib Path9386194
Ref: 2669386194
Ref: library/pathlib pathlib PosixPath9386577
Ref: 2c199386577
Ref: library/pathlib pathlib WindowsPath9387072
Ref: 2c069387072
Node: Parsing and generating URIs9388639
Ref: library/pathlib parsing-and-generating-uris9388755
Ref: 2c1a9388755
Ref: library/pathlib pathlib Path from_uri9389046
Ref: 5359389046
Ref: library/pathlib pathlib Path as_uri9390366
Ref: 31c9390366
Ref: Parsing and generating URIs-Footnote-19391007
Node: Expanding and resolving paths9391066
Ref: library/pathlib expanding-and-resolving-paths9391220
Ref: 2c1c9391220
Ref: library/pathlib pathlib Path home9391301
Ref: 10459391301
Ref: library/pathlib pathlib Path expanduser9391671
Ref: 10449391671
Ref: library/pathlib pathlib Path cwd9392076
Ref: 1a839392076
Ref: library/pathlib pathlib Path absolute9392298
Ref: 1a0e9392298
Ref: library/pathlib pathlib Path resolve9392592
Ref: 1a559392592
Ref: library/pathlib pathlib Path readlink9393735
Ref: b1b9393735
Node: Querying file type and status9394230
Ref: library/pathlib querying-file-type-and-status9394382
Ref: 2c1d9394382
Ref: library/pathlib pathlib Path stat9395276
Ref: a269395276
Ref: library/pathlib pathlib Path lstat9395874
Ref: 2c1e9395874
Ref: library/pathlib pathlib Path exists9396059
Ref: c0d9396059
Ref: library/pathlib pathlib Path is_file9396773
Ref: 53a9396773
Ref: library/pathlib pathlib Path is_dir9397303
Ref: 53b9397303
Ref: library/pathlib pathlib Path is_symlink9397841
Ref: c0f9397841
Ref: library/pathlib pathlib Path is_junction9398189
Ref: 6d39398189
Ref: library/pathlib pathlib Path is_mount9398402
Ref: c0e9398402
Ref: library/pathlib pathlib Path is_socket9399110
Ref: c139399110
Ref: library/pathlib pathlib Path is_fifo9399416
Ref: c129399416
Ref: library/pathlib pathlib Path is_block_device9399704
Ref: c109399704
Ref: library/pathlib pathlib Path is_char_device9400018
Ref: c119400018
Ref: library/pathlib pathlib Path samefile9400339
Ref: 10429400339
Ref: library/pathlib pathlib Path info9400894
Ref: 26b9400894
Node: Reading and writing files9402147
Ref: library/pathlib reading-and-writing-files9402289
Ref: 2c1f9402289
Ref: library/pathlib pathlib Path open9402362
Ref: 2c209402362
Ref: library/pathlib pathlib Path read_text9402715
Ref: 10479402715
Ref: library/pathlib pathlib Path read_bytes9403235
Ref: 2df9403235
Ref: library/pathlib pathlib Path write_text9403546
Ref: 10469403546
Ref: library/pathlib pathlib Path write_bytes9404117
Ref: 10489404117
Node: Reading directories9404500
Ref: library/pathlib reading-directories9404643
Ref: 2c219404643
Ref: library/pathlib pathlib Path iterdir9404704
Ref: 26e9404704
Ref: library/pathlib pathlib Path glob9405559
Ref: 5389405559
Ref: library/pathlib pathlib Path rglob9407630
Ref: 5399407630
Ref: library/pathlib pathlib Path walk9408511
Ref: 6d09408511
Node: Creating files and directories9413495
Ref: library/pathlib creating-files-and-directories9413640
Ref: 2c239413640
Ref: library/pathlib pathlib Path touch9413723
Ref: 2c249413723
Ref: library/pathlib pathlib Path mkdir9414310
Ref: 10439414310
Ref: library/pathlib pathlib Path symlink_to9415377
Ref: a259415377
Ref: library/pathlib pathlib Path hardlink_to9416470
Ref: a249416470
Node: Copying moving and deleting9416909
Ref: library/pathlib copying-moving-and-deleting9417060
Ref: 2c259417060
Ref: library/pathlib pathlib Path copy9417139
Ref: 2679417139
Ref: library/pathlib pathlib Path copy_into9418292
Ref: 2689418292
Ref: library/pathlib pathlib Path rename9418669
Ref: 18799418669
Ref: library/pathlib pathlib Path replace9419695
Ref: 2c269419695
Ref: library/pathlib pathlib Path move9420238
Ref: 2699420238
Ref: library/pathlib pathlib Path move_into9420917
Ref: 26a9420917
Ref: library/pathlib pathlib Path unlink9421167
Ref: 1dbd9421167
Ref: library/pathlib pathlib Path rmdir9421667
Ref: 2c229421667
Node: Permissions and ownership9421753
Ref: library/pathlib permissions-and-ownership9421865
Ref: 2c279421865
Ref: library/pathlib pathlib Path owner9421938
Ref: 53c9421938
Ref: library/pathlib pathlib Path group9422569
Ref: 53d9422569
Ref: library/pathlib pathlib Path chmod9423202
Ref: a279423202
Ref: library/pathlib pathlib Path lchmod9423807
Ref: 2c289423807
Node: Pattern language9423990
Ref: library/pathlib pathlib-pattern-language9424148
Ref: 2c179424148
Ref: library/pathlib pattern-language9424148
Ref: 2c299424148
Node: Comparison to the glob module9426642
Ref: library/pathlib comparison-to-the-glob-module9426826
Ref: 2c2a9426826
Node: Comparison to the os and os path modules9428270
Ref: library/pathlib comparison-to-the-os-and-os-path-modules9428447
Ref: 2c2b9428447
Node: Corresponding tools9430632
Ref: library/pathlib corresponding-tools9430728
Ref: 2c2c9430728
Ref: Corresponding tools-Footnote-19435998
Ref: Corresponding tools-Footnote-29436310
Ref: Corresponding tools-Footnote-39436492
Ref: Corresponding tools-Footnote-49436718
Node: Protocols9436950
Ref: library/pathlib module-pathlib types9437089
Ref: a99437089
Ref: library/pathlib protocols9437089
Ref: 2c2f9437089
Ref: library/pathlib pathlib types PathInfo9437232
Ref: 26c9437232
Ref: library/pathlib pathlib types PathInfo exists9437425
Ref: 2c309437425
Ref: library/pathlib pathlib types PathInfo is_dir9437776
Ref: 2c319437776
Ref: library/pathlib pathlib types PathInfo is_file9438289
Ref: 2c329438289
Ref: library/pathlib pathlib types PathInfo is_symlink9438802
Ref: 2c339438802
Node: os path — Common pathname manipulations9439025
Ref: library/os path doc9439224
Ref: 2c349439224
Ref: library/os path module-os path9439224
Ref: a69439224
Ref: library/os path os-path-common-pathname-manipulations9439224
Ref: 2c359439224
Ref: library/os path translation-repo9439224
Ref: 2c369439224
Ref: library/os path os path abspath9441241
Ref: 15229441241
Ref: library/os path os path basename9441627
Ref: 2c2e9441627
Ref: library/os path os path commonpath9442146
Ref: 103f9442146
Ref: library/os path os path commonprefix9442722
Ref: 10409442722
Ref: library/os path os path dirname9443379
Ref: 2c2d9443379
Ref: library/os path os path exists9443659
Ref: c059443659
Ref: library/os path os path lexists9444257
Ref: c069444257
Ref: library/os path os path expanduser9444554
Ref: c0b9444554
Ref: library/os path os path expandvars9445641
Ref: 15e09445641
Ref: library/os path os path getatime9446138
Ref: 2c389446138
Ref: library/os path os path getmtime9446441
Ref: 2c399446441
Ref: library/os path os path getctime9446824
Ref: 2c3a9446824
Ref: library/os path os path getsize9447322
Ref: 2c3b9447322
Ref: library/os path os path isabs9447560
Ref: 5329447560
Ref: library/os path os path isfile9448079
Ref: c089448079
Ref: library/os path os path isdir9448389
Ref: c079448389
Ref: library/os path os path isjunction9448698
Ref: 6cb9448698
Ref: library/os path os path islink9448965
Ref: c039448965
Ref: library/os path os path ismount9449274
Ref: c099449274
Ref: library/os path os path isdevdrive9450302
Ref: 19aa9450302
Ref: library/os path os path isreserved9451143
Ref: 32b9451143
Ref: library/os path os path join9452016
Ref: 19919452016
Ref: library/os path os path normcase9453479
Ref: 2c3c9453479
Ref: library/os path os path normpath9453826
Ref: 15219453826
Ref: library/os path os path realpath9454737
Ref: 2629454737
Ref: library/os path os path ALLOW_MISSING9456991
Ref: 2639456991
Ref: library/os path os path relpath9457135
Ref: 6d29457135
Ref: library/os path os path samefile9457666
Ref: 11739457666
Ref: library/os path os path sameopenfile9458198
Ref: 2c3e9458198
Ref: library/os path os path samestat9458470
Ref: 11729458470
Ref: library/os path os path split9458915
Ref: 2c379458915
Ref: library/os path os path splitdrive9459732
Ref: df19459732
Ref: library/os path os path splitroot9460573
Ref: 6cc9460573
Ref: library/os path os path splitext9461843
Ref: 19419461843
Ref: library/os path os path supports_unicode_filenames9462813
Ref: 16959462813
Ref: os path — Common pathname manipulations-Footnote-19463021
Ref: os path — Common pathname manipulations-Footnote-29463092
Ref: os path — Common pathname manipulations-Footnote-39463161
Ref: os path — Common pathname manipulations-Footnote-49463227
Ref: os path — Common pathname manipulations-Footnote-59463282
Ref: os path — Common pathname manipulations-Footnote-69463374
Node: stat — Interpreting stat results9463466
Ref: library/stat doc9463663
Ref: 2c3f9463663
Ref: library/stat module-stat9463663
Ref: d69463663
Ref: library/stat stat-interpreting-stat-results9463663
Ref: 2c409463663
Ref: library/stat translation-repo9463663
Ref: 2c419463663
Ref: library/stat stat S_ISDIR9464346
Ref: 2c429464346
Ref: library/stat stat S_ISCHR9464436
Ref: 2c439464436
Ref: library/stat stat S_ISBLK9464551
Ref: 2c449464551
Ref: library/stat stat S_ISREG9464657
Ref: 2c459464657
Ref: library/stat stat S_ISFIFO9464750
Ref: 2c469464750
Ref: library/stat stat S_ISLNK9464849
Ref: 2c479464849
Ref: library/stat stat S_ISSOCK9464943
Ref: 2c489464943
Ref: library/stat stat S_ISDOOR9465031
Ref: 1d939465031
Ref: library/stat stat S_ISPORT9465145
Ref: 1d949465145
Ref: library/stat stat S_ISWHT9465266
Ref: 1d959465266
Ref: library/stat stat S_IMODE9465473
Ref: 2c499465473
Ref: library/stat stat S_IFMT9465740
Ref: 2c4a9465740
Ref: library/stat stat filemode9467271
Ref: 13539467271
Ref: library/stat stat ST_MODE9467692
Ref: 11bc9467692
Ref: library/stat stat ST_INO9467745
Ref: 2c4b9467745
Ref: library/stat stat ST_DEV9467788
Ref: 2c4c9467788
Ref: library/stat stat ST_NLINK9467842
Ref: 2c4d9467842
Ref: library/stat stat ST_UID9467903
Ref: 2c4e9467903
Ref: library/stat stat ST_GID9467954
Ref: 2c4f9467954
Ref: library/stat stat ST_SIZE9468006
Ref: 2c509468006
Ref: library/stat stat ST_ATIME9468118
Ref: 2c519468118
Ref: library/stat stat ST_MTIME9468170
Ref: 2c529468170
Ref: library/stat stat ST_CTIME9468228
Ref: 2c539468228
Ref: library/stat stat S_IFSOCK9469265
Ref: 2c549469265
Ref: library/stat stat S_IFLNK9469304
Ref: 2c559469304
Ref: library/stat stat S_IFREG9469349
Ref: 2c569469349
Ref: library/stat stat S_IFBLK9469393
Ref: 2c579469393
Ref: library/stat stat S_IFDIR9469437
Ref: 2c589469437
Ref: library/stat stat S_IFCHR9469478
Ref: 2c599469478
Ref: library/stat stat S_IFIFO9469526
Ref: 2c5a9469526
Ref: library/stat stat S_IFDOOR9469562
Ref: 11bd9469562
Ref: library/stat stat S_IFPORT9469627
Ref: 11be9469627
Ref: library/stat stat S_IFWHT9469698
Ref: 11bf9469698
Ref: library/stat stat S_ISUID9470021
Ref: 2c5b9470021
Ref: library/stat stat S_ISGID9470064
Ref: 2c5c9470064
Ref: library/stat stat S_ISVTX9470641
Ref: 2c5f9470641
Ref: library/stat stat S_IRWXU9470890
Ref: 2c609470890
Ref: library/stat stat S_IRUSR9470953
Ref: 2c619470953
Ref: library/stat stat S_IWUSR9471010
Ref: 2c629471010
Ref: library/stat stat S_IXUSR9471068
Ref: 2c639471068
Ref: library/stat stat S_IRWXG9471128
Ref: 2c649471128
Ref: library/stat stat S_IRGRP9471186
Ref: 2c659471186
Ref: library/stat stat S_IWGRP9471243
Ref: 2c669471243
Ref: library/stat stat S_IXGRP9471301
Ref: 2c5d9471301
Ref: library/stat stat S_IRWXO9471361
Ref: 2c679471361
Ref: library/stat stat S_IROTH9471439
Ref: 2c689471439
Ref: library/stat stat S_IWOTH9471498
Ref: 2c699471498
Ref: library/stat stat S_IXOTH9471558
Ref: 2c6a9471558
Ref: library/stat stat S_ENFMT9471620
Ref: 2c5e9471620
Ref: library/stat stat S_IREAD9471853
Ref: 2c6b9471853
Ref: library/stat stat S_IWRITE9471924
Ref: 2c6c9471924
Ref: library/stat stat S_IEXEC9471996
Ref: 2c6d9471996
Ref: library/stat stat UF_SETTABLE9472154
Ref: 2c6e9472154
Ref: library/stat stat UF_NODUMP9472242
Ref: 2c6f9472242
Ref: library/stat stat UF_IMMUTABLE9472296
Ref: 2c709472296
Ref: library/stat stat UF_APPEND9472360
Ref: 2c719472360
Ref: library/stat stat UF_OPAQUE9472426
Ref: 2c729472426
Ref: library/stat stat UF_NOUNLINK9472517
Ref: 2c739472517
Ref: library/stat stat UF_COMPRESSED9472591
Ref: 2c749472591
Ref: library/stat stat UF_TRACKED9472672
Ref: 2c759472672
Ref: library/stat stat UF_DATAVAULT9472773
Ref: 2c769472773
Ref: library/stat stat UF_HIDDEN9472905
Ref: 2c779472905
Ref: library/stat stat SF_SETTABLE9472994
Ref: 2c789472994
Ref: library/stat stat SF_SUPPORTED9473089
Ref: 2c799473089
Ref: library/stat stat SF_SYNTHETIC9473223
Ref: 2c7a9473223
Ref: library/stat stat SF_ARCHIVED9473367
Ref: 2c7b9473367
Ref: library/stat stat SF_IMMUTABLE9473427
Ref: 2c7c9473427
Ref: library/stat stat SF_APPEND9473491
Ref: 2c7d9473491
Ref: library/stat stat SF_RESTRICTED9473557
Ref: 2c7e9473557
Ref: library/stat stat SF_NOUNLINK9473679
Ref: 2c7f9473679
Ref: library/stat stat SF_SNAPSHOT9473753
Ref: 2c809473753
Ref: library/stat stat SF_FIRMLINK9473816
Ref: 2c819473816
Ref: library/stat stat SF_DATALESS9473917
Ref: 2c829473917
Ref: library/stat stat FILE_ATTRIBUTE_ARCHIVE9474361
Ref: 2c839474361
Ref: library/stat stat FILE_ATTRIBUTE_COMPRESSED9474399
Ref: 2c849474399
Ref: library/stat stat FILE_ATTRIBUTE_DEVICE9474440
Ref: 2c859474440
Ref: library/stat stat FILE_ATTRIBUTE_DIRECTORY9474477
Ref: 2c869474477
Ref: library/stat stat FILE_ATTRIBUTE_ENCRYPTED9474517
Ref: 2c879474517
Ref: library/stat stat FILE_ATTRIBUTE_HIDDEN9474557
Ref: 2c889474557
Ref: library/stat stat FILE_ATTRIBUTE_INTEGRITY_STREAM9474594
Ref: 2c899474594
Ref: library/stat stat FILE_ATTRIBUTE_NORMAL9474641
Ref: 2c8a9474641
Ref: library/stat stat FILE_ATTRIBUTE_NOT_CONTENT_INDEXED9474678
Ref: 2c8b9474678
Ref: library/stat stat FILE_ATTRIBUTE_NO_SCRUB_DATA9474728
Ref: 2c8c9474728
Ref: library/stat stat FILE_ATTRIBUTE_OFFLINE9474772
Ref: 2c8d9474772
Ref: library/stat stat FILE_ATTRIBUTE_READONLY9474810
Ref: 2c8e9474810
Ref: library/stat stat FILE_ATTRIBUTE_REPARSE_POINT9474849
Ref: 2c8f9474849
Ref: library/stat stat FILE_ATTRIBUTE_SPARSE_FILE9474893
Ref: 2c909474893
Ref: library/stat stat FILE_ATTRIBUTE_SYSTEM9474935
Ref: 2c919474935
Ref: library/stat stat FILE_ATTRIBUTE_TEMPORARY9474972
Ref: 2c929474972
Ref: library/stat stat FILE_ATTRIBUTE_VIRTUAL9475012
Ref: 2c939475012
Ref: library/stat stat IO_REPARSE_TAG_SYMLINK9475284
Ref: 2c949475284
Ref: library/stat stat IO_REPARSE_TAG_MOUNT_POINT9475322
Ref: 2c959475322
Ref: library/stat stat IO_REPARSE_TAG_APPEXECLINK9475364
Ref: 2c969475364
Ref: stat — Interpreting stat results-Footnote-19475471
Ref: stat — Interpreting stat results-Footnote-29475535
Ref: stat — Interpreting stat results-Footnote-39475582
Node: filecmp — File and Directory Comparisons9475662
Ref: library/filecmp doc9475871
Ref: 2c979475871
Ref: library/filecmp filecmp-file-and-directory-comparisons9475871
Ref: 2c989475871
Ref: library/filecmp module-filecmp9475871
Ref: 5e9475871
Ref: library/filecmp translation-repo9475871
Ref: 2c999475871
Ref: library/filecmp filecmp cmp9476340
Ref: 19c59476340
Ref: library/filecmp filecmp cmpfiles9477134
Ref: 192d9477134
Ref: library/filecmp filecmp clear_cache9478079
Ref: 11409478079
Ref: filecmp — File and Directory Comparisons-Footnote-19478396
Node: The dircmp class9478463
Ref: library/filecmp dircmp-objects9478558
Ref: 2c9a9478558
Ref: library/filecmp the-dircmp-class9478558
Ref: 2c9b9478558
Ref: library/filecmp filecmp dircmp9478619
Ref: 11429478619
Ref: library/filecmp filecmp dircmp report9479299
Ref: 2c9c9479299
Ref: library/filecmp filecmp dircmp report_partial_closure9479416
Ref: 2c9d9479416
Ref: library/filecmp filecmp dircmp report_full_closure9479557
Ref: 2c9e9479557
Ref: library/filecmp filecmp dircmp left9480077
Ref: 2c9f9480077
Ref: library/filecmp filecmp dircmp right9480133
Ref: 2ca09480133
Ref: library/filecmp filecmp dircmp left_list9480190
Ref: 2ca19480190
Ref: library/filecmp filecmp dircmp right_list9480308
Ref: 2ca29480308
Ref: library/filecmp filecmp dircmp common9480427
Ref: 2ca39480427
Ref: library/filecmp filecmp dircmp left_only9480512
Ref: 2ca49480512
Ref: library/filecmp filecmp dircmp right_only9480592
Ref: 2ca59480592
Ref: library/filecmp filecmp dircmp common_dirs9480673
Ref: 2ca69480673
Ref: library/filecmp filecmp dircmp common_files9480753
Ref: 2ca79480753
Ref: library/filecmp filecmp dircmp common_funny9480825
Ref: 2ca89480825
Ref: library/filecmp filecmp dircmp same_files9481028
Ref: 2ca99481028
Ref: library/filecmp filecmp dircmp diff_files9481174
Ref: 2caa9481174
Ref: library/filecmp filecmp dircmp funny_files9481339
Ref: 2cab9481339
Ref: library/filecmp filecmp dircmp subdirs9481457
Ref: 1ccd9481457
Ref: library/filecmp filecmp DEFAULT_IGNORES9481924
Ref: 11419481924
Node: tempfile — Generate temporary files and directories9482606
Ref: library/tempfile doc9482827
Ref: 2cac9482827
Ref: library/tempfile module-tempfile9482827
Ref: e69482827
Ref: library/tempfile tempfile-generate-temporary-files-and-directories9482827
Ref: 2cad9482827
Ref: library/tempfile translation-repo9482827
Ref: 2cae9482827
Ref: library/tempfile tempfile TemporaryFile9483993
Ref: 2caf9483993
Ref: library/tempfile tempfile NamedTemporaryFile9486180
Ref: 6ee9486180
Ref: library/tempfile tempfile SpooledTemporaryFile9489990
Ref: 8a39489990
Ref: library/tempfile tempfile SpooledTemporaryFile rollover9490513
Ref: 2cb29490513
Ref: library/tempfile tempfile TemporaryDirectory9491491
Ref: 143c9491491
Ref: library/tempfile tempfile TemporaryDirectory name9492019
Ref: 2cb39492019
Ref: library/tempfile tempfile TemporaryDirectory cleanup9492374
Ref: 2cb49492374
Ref: library/tempfile tempfile mkstemp9493649
Ref: 2cb09493649
Ref: library/tempfile tempfile mkdtemp9496563
Ref: 52e9496563
Ref: library/tempfile tempfile gettempdir9497812
Ref: 1c7b9497812
Ref: library/tempfile tempfile gettempdirb9499001
Ref: 1c7c9499001
Ref: library/tempfile tempfile gettempprefix9499142
Ref: 2cb69499142
Ref: library/tempfile tempfile gettempprefixb9499301
Ref: 2cb79499301
Ref: library/tempfile tempfile tempdir9499880
Ref: 1c7a9499880
Ref: tempfile — Generate temporary files and directories-Footnote-19500995
Node: Examples<5>9501063
Ref: library/tempfile examples9501207
Ref: 2cb89501207
Ref: library/tempfile tempfile-examples9501207
Ref: 2cb19501207
Node: Deprecated functions and variables9502602
Ref: library/tempfile deprecated-functions-and-variables9502746
Ref: 2cb99502746
Ref: library/tempfile tempfile-mktemp-deprecated9502746
Ref: 2cba9502746
Ref: library/tempfile tempfile mktemp9503376
Ref: 1c189503376
Node: glob — Unix style pathname pattern expansion9504514
Ref: library/glob doc9504735
Ref: 2cbb9504735
Ref: library/glob glob-unix-style-pathname-pattern-expansion9504735
Ref: 2cbc9504735
Ref: library/glob module-glob9504735
Ref: 689504735
Ref: library/glob translation-repo9504735
Ref: 2cbd9504735
Ref: library/glob glob glob9505896
Ref: 5a09505896
Ref: library/glob glob iglob9508235
Ref: a0a9508235
Ref: library/glob glob escape9509163
Ref: 11479509163
Ref: library/glob glob translate9509586
Ref: 4fc9509586
Ref: glob — Unix style pathname pattern expansion-Footnote-19511151
Node: Examples<6>9511215
Ref: library/glob examples9511309
Ref: 2cbe9511309
Node: fnmatch — Unix filename pattern matching9512426
Ref: library/fnmatch doc9512635
Ref: 2cbf9512635
Ref: library/fnmatch fnmatch-unix-filename-pattern-matching9512635
Ref: 2cc09512635
Ref: library/fnmatch module-fnmatch9512635
Ref: 609512635
Ref: library/fnmatch translation-repo9512635
Ref: 2cc19512635
Ref: library/fnmatch fnmatch fnmatch9514510
Ref: 1c3c9514510
Ref: library/fnmatch fnmatch fnmatchcase9515187
Ref: 1c3d9515187
Ref: library/fnmatch fnmatch filter9515445
Ref: 1c3e9515445
Ref: library/fnmatch fnmatch filterfalse9515737
Ref: 2119515737
Ref: library/fnmatch fnmatch translate9516075
Ref: 18379516075
Ref: fnmatch — Unix filename pattern matching-Footnote-19516714
Node: linecache — Random access to text lines9516781
Ref: library/linecache doc9516981
Ref: 2cc29516981
Ref: library/linecache linecache-random-access-to-text-lines9516981
Ref: 2cc39516981
Ref: library/linecache module-linecache9516981
Ref: 899516981
Ref: library/linecache translation-repo9516981
Ref: 2cc49516981
Ref: library/linecache linecache getline9517811
Ref: 2409517811
Ref: library/linecache linecache clearcache9518873
Ref: 2cc69518873
Ref: library/linecache linecache checkcache9519042
Ref: 18d39519042
Ref: library/linecache linecache lazycache9519320
Ref: 10269519320
Ref: linecache — Random access to text lines-Footnote-19519869
Ref: linecache — Random access to text lines-Footnote-29519938
Node: shutil — High-level file operations9519980
Ref: library/shutil doc9520129
Ref: 2cc79520129
Ref: library/shutil module-shutil9520129
Ref: ca9520129
Ref: library/shutil shutil-high-level-file-operations9520129
Ref: 2cc89520129
Ref: library/shutil translation-repo9520129
Ref: 2cc99520129
Ref: shutil — High-level file operations-Footnote-19521235
Node: Directory and files operations9521301
Ref: library/shutil directory-and-files-operations9521434
Ref: 2cca9521434
Ref: library/shutil file-operations9521434
Ref: 2ccb9521434
Ref: library/shutil shutil copyfileobj9521515
Ref: c549521515
Ref: library/shutil shutil copyfile9522599
Ref: c509522599
Ref: library/shutil shutil SpecialFileError9524235
Ref: 15239524235
Ref: library/shutil shutil SameFileError9524423
Ref: 11a09524423
Ref: library/shutil shutil copymode9524595
Ref: 1a0c9524595
Ref: library/shutil shutil copystat9525508
Ref: 13369525508
Ref: library/shutil shutil copy9527652
Ref: c519527652
Ref: library/shutil shutil copy29529173
Ref: c529529173
Ref: library/shutil shutil ignore_patterns9530704
Ref: 2ccd9530704
Ref: library/shutil shutil copytree9531004
Ref: c209531004
Ref: library/shutil shutil rmtree9534512
Ref: 3569534512
Ref: library/shutil shutil rmtree avoids_symlink_attacks9537323
Ref: 2cce9537323
Ref: library/shutil shutil move9537665
Ref: c539537665
Ref: library/shutil shutil disk_usage9539739
Ref: 13359539739
Ref: library/shutil shutil chown9540443
Ref: 5499540443
Ref: library/shutil shutil which9541071
Ref: 6dc9541071
Ref: library/shutil shutil Error9543702
Ref: 119f9543702
Node: Platform-dependent efficient copy operations9544038
Ref: library/shutil platform-dependent-efficient-copy-operations9544174
Ref: 2cd09544174
Ref: library/shutil shutil-platform-dependent-efficient-copy-operations9544174
Ref: c559544174
Ref: Platform-dependent efficient copy operations-Footnote-19545611
Ref: Platform-dependent efficient copy operations-Footnote-29545676
Node: copytree example9545724
Ref: library/shutil copytree-example9545883
Ref: 2cd19545883
Ref: library/shutil shutil-copytree-example9545883
Ref: 2cd29545883
Node: rmtree example9546543
Ref: library/shutil rmtree-example9546649
Ref: 2cd39546649
Ref: library/shutil shutil-rmtree-example9546649
Ref: 2ccf9546649
Node: Archiving operations9547190
Ref: library/shutil archiving-operations9547372
Ref: 14209547372
Ref: library/shutil id19547372
Ref: 2cd49547372
Ref: library/shutil shutil make_archive9547684
Ref: 6db9547684
Ref: library/shutil shutil get_archive_formats9550196
Ref: 2cd79550196
Ref: library/shutil shutil register_archive_format9551158
Ref: 2cd69551158
Ref: library/shutil shutil unregister_archive_format9552464
Ref: 2cd89552464
Ref: library/shutil shutil unpack_archive9552599
Ref: 6979552599
Ref: library/shutil shutil register_unpack_format9554660
Ref: 2cd99554660
Ref: library/shutil shutil unregister_unpack_format9555579
Ref: 2cdc9555579
Ref: library/shutil shutil get_unpack_formats9555703
Ref: 2cdb9555703
Ref: Archiving operations-Footnote-19556776
Node: Archiving example9556818
Ref: library/shutil archiving-example9556932
Ref: 2cdd9556932
Ref: library/shutil shutil-archiving-example9556932
Ref: 2cde9556932
Node: Archiving example with base_dir9558023
Ref: library/shutil archiving-example-with-base-dir9558137
Ref: 2cdf9558137
Ref: library/shutil shutil-archiving-example-with-basedir9558137
Ref: 2cd59558137
Node: Querying the size of the output terminal9559238
Ref: library/shutil querying-the-size-of-the-output-terminal9559381
Ref: 2ce09559381
Ref: library/shutil shutil get_terminal_size9559482
Ref: 130b9559482
Ref: Querying the size of the output terminal-Footnote-19561153
Node: Data Persistence9561236
Ref: library/persistence doc9561389
Ref: 2ce39561389
Ref: library/persistence data-persistence9561389
Ref: 2ce49561389
Ref: library/persistence persistence9561389
Ref: 2ce59561389
Ref: library/persistence translation-repo9561389
Ref: 2ce69561389
Node: pickle — Python object serialization9562218
Ref: library/pickle doc9562363
Ref: 2ce79562363
Ref: library/pickle module-pickle9562363
Ref: ab9562363
Ref: library/pickle pickle-python-object-serialization9562363
Ref: 2ce89562363
Ref: pickle — Python object serialization-Footnote-19564216
Ref: pickle — Python object serialization-Footnote-29564282
Node: Relationship to other Python modules9564346
Ref: library/pickle relationship-to-other-python-modules9564484
Ref: 2cea9564484
Node: Comparison with marshal9564640
Ref: library/pickle comparison-with-marshal9564765
Ref: 2ceb9564765
Node: Comparison with json9566134
Ref: library/pickle comparison-with-json9566259
Ref: 2ce99566259
Ref: library/pickle id29566259
Ref: 2cec9566259
Ref: Comparison with json-Footnote-19567428
Node: Data stream format9567453
Ref: library/pickle data-stream-format9567616
Ref: 2cee9567616
Ref: library/pickle pickle-protocols9567616
Ref: 27b9567616
Ref: Data stream format-Footnote-19570635
Ref: Data stream format-Footnote-29570677
Ref: Data stream format-Footnote-39570719
Node: Module Interface9570761
Ref: library/pickle module-interface9570922
Ref: 2cf19570922
Ref: library/pickle pickle HIGHEST_PROTOCOL9571375
Ref: 16ac9571375
Ref: library/pickle pickle DEFAULT_PROTOCOL9571648
Ref: a319571648
Ref: library/pickle pickle dump9572384
Ref: 2cf29572384
Ref: library/pickle pickle dumps9572893
Ref: 16ab9572893
Ref: library/pickle pickle load9573340
Ref: f0e9573340
Ref: library/pickle pickle loads9574094
Ref: f0f9574094
Ref: library/pickle pickle PickleError9574827
Ref: 2cf39574827
Ref: library/pickle pickle PicklingError9574966
Ref: 192a9574966
Ref: library/pickle pickle UnpicklingError9575250
Ref: 2cf59575250
Ref: library/pickle pickle Pickler9575764
Ref: c159575764
Ref: library/pickle pickle Pickler dump9577361
Ref: 1e0d9577361
Ref: library/pickle pickle Pickler persistent_id9577503
Ref: 18f49577503
Ref: library/pickle pickle Pickler dispatch_table9578318
Ref: 132a9578318
Ref: library/pickle pickle Pickler reducer_override9579487
Ref: c169579487
Ref: library/pickle pickle Pickler fast9580116
Ref: 2cfb9580116
Ref: library/pickle pickle Pickler clear_memo9580601
Ref: 2cfd9580601
Ref: library/pickle pickle Unpickler9580934
Ref: 175e9580934
Ref: library/pickle pickle Unpickler load9583064
Ref: 2cfe9583064
Ref: library/pickle pickle Unpickler persistent_load9583359
Ref: 18fc9583359
Ref: library/pickle pickle Unpickler find_class9583947
Ref: 2cff9583947
Ref: library/pickle pickle PickleBuffer9584627
Ref: 17629584627
Ref: library/pickle pickle PickleBuffer raw9585247
Ref: 2d019585247
Ref: library/pickle pickle PickleBuffer release9585590
Ref: 2d029585590
Ref: Module Interface-Footnote-19585742
Node: What can be pickled and unpickled?9585784
Ref: library/pickle pickle-picklable9585951
Ref: 2cf49585951
Ref: library/pickle what-can-be-pickled-and-unpickled9585951
Ref: 2d039585951
Ref: What can be pickled and unpickled?-Footnote-19588698
Ref: What can be pickled and unpickled?-Footnote-29588831
Node: Pickling Class Instances9588967
Ref: library/pickle pickle-inst9589172
Ref: 2ced9589172
Ref: library/pickle pickling-class-instances9589172
Ref: 2d049589172
Ref: library/pickle object __getnewargs_ex__9590107
Ref: 2d059590107
Ref: library/pickle object __getnewargs__9590944
Ref: fd69590944
Ref: library/pickle object __getstate__9591515
Ref: 7f29591515
Ref: library/pickle object __setstate__9592862
Ref: bc99592862
Ref: library/pickle object __reduce__9594722
Ref: bc89594722
Ref: library/pickle object __reduce_ex__9597612
Ref: 19539597612
Ref: Pickling Class Instances-Footnote-19598273
Node: Persistence of External Objects9598368
Ref: library/pickle persistence-of-external-objects9598484
Ref: 2d079598484
Ref: library/pickle pickle-persistent9598484
Ref: 2cf79598484
Ref: Persistence of External Objects-Footnote-19603152
Node: Dispatch Tables9603416
Ref: library/pickle dispatch-tables9603566
Ref: 2d089603566
Ref: library/pickle pickle-dispatch9603566
Ref: 2cf99603566
Node: Handling Stateful Objects9604854
Ref: library/pickle handling-stateful-objects9604964
Ref: 2d099604964
Ref: library/pickle pickle-state9604964
Ref: 2d069604964
Node: Custom Reduction for Types Functions and Other Objects9607246
Ref: library/pickle custom-reduction-for-types-functions-and-other-objects9607436
Ref: 2d0a9607436
Ref: library/pickle reducer-override9607436
Ref: 2cfa9607436
Node: Out-of-band Buffers9609538
Ref: library/pickle out-of-band-buffers9609723
Ref: 2d0b9609723
Ref: library/pickle pickle-oob9609723
Ref: 2cf69609723
Node: Provider API9610573
Ref: library/pickle provider-api9610662
Ref: 2d0c9610662
Node: Consumer API9611269
Ref: library/pickle consumer-api9611377
Ref: 2d0d9611377
Node: Example<4>9612680
Ref: library/pickle example9612767
Ref: 2d0e9612767
Ref: Example<4>-Footnote-19615155
Node: Restricting Globals9615197
Ref: library/pickle pickle-restrict9615342
Ref: 2d009615342
Ref: library/pickle restricting-globals9615342
Ref: 2d0f9615342
Node: Performance<2>9618116
Ref: library/pickle performance9618253
Ref: 2d109618253
Node: Examples<7>9618529
Ref: library/pickle examples9618669
Ref: 2d119618669
Ref: library/pickle pickle-example9618669
Ref: 2d129618669
Node: Command-line interface9619450
Ref: library/pickle command-line-interface9619567
Ref: 2d139619567
Ref: library/pickle pickle-cli9619567
Ref: 2d149619567
Ref: library/pickle cmdoption-pickle-arg-pickle_file9620059
Ref: 2d169620059
Node: copyreg — Register pickle support functions9620608
Ref: library/copyreg doc9620798
Ref: 2d179620798
Ref: library/copyreg copyreg-register-pickle-support-functions9620798
Ref: 2d189620798
Ref: library/copyreg module-copyreg9620798
Ref: 2a9620798
Ref: library/copyreg translation-repo9620798
Ref: 2d199620798
Ref: library/copyreg copyreg constructor9621390
Ref: 2d1a9621390
Ref: library/copyreg copyreg pickle9621593
Ref: 2cf89621593
Ref: copyreg — Register pickle support functions-Footnote-19622331
Node: Example<5>9622398
Ref: library/copyreg example9622490
Ref: 2d1b9622490
Node: shelve — Python object persistence9623034
Ref: library/shelve doc9623234
Ref: 2d1c9623234
Ref: library/shelve module-shelve9623234
Ref: c89623234
Ref: library/shelve shelve-python-object-persistence9623234
Ref: 2d1d9623234
Ref: library/shelve translation-repo9623234
Ref: 2d1e9623234
Ref: library/shelve shelve open9623815
Ref: 1a599623815
Ref: library/shelve shelve-security9625868
Ref: 2d229625868
Ref: library/shelve shelve Shelf sync9626372
Ref: 2d209626372
Ref: library/shelve shelve Shelf close9626693
Ref: 2d219626693
Ref: shelve — Python object persistence-Footnote-19627079
Ref: shelve — Python object persistence-Footnote-29627145
Node: Restrictions9627250
Ref: library/shelve restrictions9627354
Ref: 2d239627354
Ref: library/shelve shelve Shelf9628543
Ref: 119d9628543
Ref: library/shelve shelve BsdDbShelf9629957
Ref: 269b9629957
Ref: library/shelve shelve DbfilenameShelf9630682
Ref: 269c9630682
Ref: Restrictions-Footnote-19631301
Node: Example<6>9631354
Ref: library/shelve example9631458
Ref: 2d249631458
Ref: library/shelve shelve-example9631458
Ref: 2d1f9631458
Node: marshal — Internal Python object serialization9633141
Ref: library/marshal doc9633336
Ref: 2d259633336
Ref: library/marshal marshal-internal-python-object-serialization9633336
Ref: 2d269633336
Ref: library/marshal module-marshal9633336
Ref: 919633336
Ref: library/marshal translation-repo9633336
Ref: 2d279633336
Ref: library/marshal marshal dump9636499
Ref: 2d299636499
Ref: library/marshal marshal load9637343
Ref: 1dde9637343
Ref: library/marshal marshal dumps9638356
Ref: 10a79638356
Ref: library/marshal marshal loads9639052
Ref: 2d2a9639052
Ref: library/marshal marshal version9639829
Ref: 2d289639829
Ref: marshal — Internal Python object serialization-Footnote-19641031
Node: dbm — Interfaces to Unix «databases»9641405
Ref: library/dbm doc9641617
Ref: 2d2b9641617
Ref: library/dbm dbm-interfaces-to-unix-databases9641617
Ref: 2d2c9641617
Ref: library/dbm module-dbm9641617
Ref: 359641617
Ref: library/dbm translation-repo9641617
Ref: 2d2d9641617
Ref: library/dbm dbm error9642161
Ref: 2d2e9642161
Ref: library/dbm dbm whichdb9642433
Ref: 2d2f9642433
Ref: library/dbm dbm open9643141
Ref: 112e9643141
Ref: dbm — Interfaces to Unix «databases»-Footnote-19647034
Ref: dbm — Interfaces to Unix «databases»-Footnote-29647106
Node: dbm sqlite3 — SQLite backend for dbm9647159
Ref: library/dbm dbm-sqlite3-sqlite-backend-for-dbm9647315
Ref: 2d309647315
Ref: library/dbm module-dbm sqlite39647315
Ref: 399647315
Ref: library/dbm dbm sqlite3 open9647977
Ref: 2d319647977
Ref: library/dbm dbm sqlite3 sqlite3 close9649106
Ref: 2d329649106
Ref: dbm sqlite3 — SQLite backend for dbm-Footnote-19649215
Node: dbm gnu — GNU database manager9649286
Ref: library/dbm dbm-gnu-gnu-database-manager9649484
Ref: 2d339649484
Ref: library/dbm module-dbm gnu9649484
Ref: 379649484
Ref: library/dbm dbm gnu error9650163
Ref: c939650163
Ref: library/dbm dbm gnu open_flags9650367
Ref: 2d349650367
Ref: library/dbm dbm gnu open9650485
Ref: 1e089650485
Ref: library/dbm dbm gnu gdbm close9652666
Ref: 2d359652666
Ref: library/dbm dbm gnu gdbm firstkey9652734
Ref: 2d369652734
Ref: library/dbm dbm gnu gdbm nextkey9653072
Ref: 2d379653072
Ref: library/dbm dbm gnu gdbm reorganize9653457
Ref: 2d389653457
Ref: library/dbm dbm gnu gdbm sync9653894
Ref: 2d399653894
Ref: dbm gnu — GNU database manager-Footnote-19654095
Node: dbm ndbm — New Database Manager9654162
Ref: library/dbm dbm-ndbm-new-database-manager9654362
Ref: 2d3a9654362
Ref: library/dbm module-dbm ndbm9654362
Ref: 389654362
Ref: library/dbm dbm ndbm error9655361
Ref: c949655361
Ref: library/dbm dbm ndbm library9655567
Ref: 2d3b9655567
Ref: library/dbm dbm ndbm open9655647
Ref: 1e099655647
Ref: library/dbm dbm ndbm ndbm close9657231
Ref: 2d3c9657231
Ref: dbm ndbm — New Database Manager-Footnote-19657335
Node: dbm dumb — Portable DBM implementation9657403
Ref: library/dbm dbm-dumb-portable-dbm-implementation9657562
Ref: 2d3d9657562
Ref: library/dbm module-dbm dumb9657562
Ref: 369657562
Ref: library/dbm dbm dumb error9658341
Ref: c929658341
Ref: library/dbm dbm dumb open9658547
Ref: c8f9658547
Ref: library/dbm dbm dumb dumbdbm close9660437
Ref: 2d3e9660437
Ref: library/dbm dbm dumb dumbdbm sync9660503
Ref: 2d3f9660503
Ref: dbm dumb — Portable DBM implementation-Footnote-19660715
Node: sqlite3 — DB-API 2 0 interface for SQLite databases9660783
Ref: library/sqlite3 doc9660938
Ref: 2d409660938
Ref: library/sqlite3 module-sqlite39660938
Ref: d49660938
Ref: library/sqlite3 sqlite3-db-api-2-0-interface-for-sqlite-databases9660938
Ref: 2d419660938
Ref: library/sqlite3 translation-repo9660938
Ref: 2d429660938
Ref: library/sqlite3 sqlite3-intro9661099
Ref: 2d439661099
Ref: sqlite3 — DB-API 2 0 interface for SQLite databases-Footnote-19662813
Ref: sqlite3 — DB-API 2 0 interface for SQLite databases-Footnote-29662878
Ref: sqlite3 — DB-API 2 0 interface for SQLite databases-Footnote-39662920
Ref: sqlite3 — DB-API 2 0 interface for SQLite databases-Footnote-49662948
Node: Tutorial9662990
Ref: library/sqlite3 sqlite3-tutorial9663106
Ref: 2d449663106
Ref: library/sqlite3 tutorial9663106
Ref: 2d489663106
Ref: Tutorial-Footnote-19669073
Ref: Tutorial-Footnote-29669130
Ref: Tutorial-Footnote-39669189
Ref: Tutorial-Footnote-49669238
Ref: Tutorial-Footnote-59669284
Node: Reference9669336
Ref: library/sqlite3 reference9669474
Ref: 2d529669474
Ref: library/sqlite3 sqlite3-reference9669474
Ref: 2d459669474
Ref: library/sqlite3 sqlite3-module-contents9669513
Ref: 2d539669513
Node: Module functions9669870
Ref: library/sqlite3 module-functions9669957
Ref: 2d549669957
Ref: library/sqlite3 sqlite3-module-functions9669957
Ref: 2d559669957
Ref: library/sqlite3 sqlite3 connect9670010
Ref: 5a69670010
Ref: library/sqlite3 sqlite3 complete_statement9674773
Ref: 2d5e9674773
Ref: library/sqlite3 sqlite3 enable_callback_tracebacks9675590
Ref: 2d5f9675590
Ref: library/sqlite3 sqlite3 register_adapter9676254
Ref: 2d609676254
Ref: library/sqlite3 sqlite3 register_converter9676592
Ref: 2d579676592
Ref: Module functions-Footnote-19677241
Ref: Module functions-Footnote-29677284
Ref: Module functions-Footnote-39677326
Node: Module constants9677403
Ref: library/sqlite3 module-constants9677517
Ref: 2d629677517
Ref: library/sqlite3 sqlite3-module-constants9677517
Ref: 2d639677517
Ref: library/sqlite3 sqlite3 LEGACY_TRANSACTION_CONTROL9677570
Ref: 2d5c9677570
Ref: library/sqlite3 sqlite3 PARSE_DECLTYPES9677844
Ref: 2d589677844
Ref: library/sqlite3 sqlite3 PARSE_COLNAMES9678825
Ref: 2d599678825
Ref: library/sqlite3 sqlite3 SQLITE_OK9679420
Ref: 2d649679420
Ref: library/sqlite3 sqlite3 SQLITE_DENY9679448
Ref: 2d659679448
Ref: library/sqlite3 sqlite3 SQLITE_IGNORE9679478
Ref: 2d669679478
Ref: library/sqlite3 sqlite3 apilevel9679912
Ref: 2d679679912
Ref: library/sqlite3 sqlite3 paramstyle9680055
Ref: 2d689680055
Ref: library/sqlite3 sqlite3 sqlite_version9680332
Ref: 3039680332
Ref: library/sqlite3 sqlite3 sqlite_version_info9680446
Ref: 3049680446
Ref: library/sqlite3 sqlite3 threadsafety9680588
Ref: 88d9680588
Ref: library/sqlite3 sqlite3-dbconfig-constants9682924
Ref: 2d699682924
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_DEFENSIVE9682924
Ref: 2d6a9682924
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_DQS_DDL9682968
Ref: 2d6b9682968
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_DQS_DML9683010
Ref: 2d6c9683010
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_ENABLE_FKEY9683052
Ref: 2d6d9683052
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER9683098
Ref: 2d6e9683098
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION9683154
Ref: 2d6f9683154
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_ENABLE_QPSG9683210
Ref: 2d709683210
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_ENABLE_TRIGGER9683256
Ref: 2d719683256
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_ENABLE_VIEW9683305
Ref: 2d729683305
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_LEGACY_ALTER_TABLE9683351
Ref: 2d739683351
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_LEGACY_FILE_FORMAT9683404
Ref: 2d749683404
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE9683457
Ref: 2d759683457
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_RESET_DATABASE9683508
Ref: 2d769683508
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_TRIGGER_EQP9683557
Ref: 2d779683557
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_TRUSTED_SCHEMA9683603
Ref: 2d789683603
Ref: library/sqlite3 sqlite3 SQLITE_DBCONFIG_WRITABLE_SCHEMA9683652
Ref: 2d799683652
Ref: Module constants-Footnote-19684274
Ref: Module constants-Footnote-29684317
Ref: Module constants-Footnote-39684372
Node: Connection objects9684423
Ref: library/sqlite3 connection-objects9684535
Ref: 2d7a9684535
Ref: library/sqlite3 sqlite3-connection-objects9684535
Ref: 2d7b9684535
Ref: library/sqlite3 sqlite3 Connection9684592
Ref: 54e9684592
Ref: library/sqlite3 sqlite3 Connection cursor9685281
Ref: 2d499685281
Ref: library/sqlite3 sqlite3 Connection blobopen9685593
Ref: 8929685593
Ref: library/sqlite3 sqlite3 Connection commit9686866
Ref: 2d4d9686866
Ref: library/sqlite3 sqlite3 Connection rollback9687225
Ref: 2d7d9687225
Ref: library/sqlite3 sqlite3 Connection close9687591
Ref: 54f9687591
Ref: library/sqlite3 sqlite3 Connection execute9688010
Ref: 2d7e9688010
Ref: library/sqlite3 sqlite3 Connection executemany9688237
Ref: 2d7f9688237
Ref: library/sqlite3 sqlite3 Connection executescript9688470
Ref: 2d809688470
Ref: library/sqlite3 sqlite3 Connection create_function9688692
Ref: 5a79688692
Ref: library/sqlite3 sqlite3 Connection create_aggregate9690393
Ref: 5a89690393
Ref: library/sqlite3 sqlite3 Connection create_window_function9692335
Ref: 8919692335
Ref: library/sqlite3 sqlite3 Connection create_collation9695539
Ref: 8879695539
Ref: library/sqlite3 sqlite3 Connection interrupt9696976
Ref: 2d849696976
Ref: library/sqlite3 sqlite3 Connection set_authorizer9697204
Ref: 5a99697204
Ref: library/sqlite3 sqlite3 Connection set_progress_handler9698850
Ref: 5aa9698850
Ref: library/sqlite3 sqlite3 Connection set_trace_callback9699705
Ref: 5ab9699705
Ref: library/sqlite3 sqlite3 Connection enable_load_extension9701011
Ref: a419701011
Ref: library/sqlite3 sqlite3 Connection load_extension9703356
Ref: 6e09703356
Ref: library/sqlite3 sqlite3 Connection iterdump9704352
Ref: 5509704352
Ref: library/sqlite3 sqlite3 Connection backup9705380
Ref: d759705380
Ref: library/sqlite3 sqlite3 Connection getlimit9707754
Ref: 88c9707754
Ref: library/sqlite3 sqlite3 Connection setlimit9708394
Ref: 88b9708394
Ref: library/sqlite3 sqlite3 Connection getconfig9709496
Ref: 6e19709496
Ref: library/sqlite3 sqlite3 Connection setconfig9709772
Ref: 6e29709772
Ref: library/sqlite3 sqlite3 Connection serialize9710222
Ref: 88f9710222
Ref: library/sqlite3 sqlite3 Connection deserialize9710977
Ref: 8909710977
Ref: library/sqlite3 sqlite3 Connection autocommit9712144
Ref: 6de9712144
Ref: library/sqlite3 sqlite3 Connection in_transaction9713573
Ref: 2d879713573
Ref: library/sqlite3 sqlite3 Connection isolation_level9713859
Ref: 2d5a9713859
Ref: library/sqlite3 sqlite3 Connection row_factory9714798
Ref: 198d9714798
Ref: library/sqlite3 sqlite3 Connection text_factory9715294
Ref: 2d899715294
Ref: library/sqlite3 sqlite3 Connection total_changes9715700
Ref: 2d8a9715700
Ref: Connection objects-Footnote-19715931
Ref: Connection objects-Footnote-29715977
Ref: Connection objects-Footnote-39716042
Ref: Connection objects-Footnote-49716101
Ref: Connection objects-Footnote-59716160
Ref: Connection objects-Footnote-69716202
Ref: Connection objects-Footnote-79716244
Ref: Connection objects-Footnote-89716336
Ref: Connection objects-Footnote-99716378
Ref: Connection objects-Footnote-109716470
Node: Cursor objects9716571
Ref: library/sqlite3 cursor-objects9716678
Ref: 2d8b9716678
Ref: library/sqlite3 sqlite3-cursor-objects9716678
Ref: 2d8c9716678
Ref: library/sqlite3 sqlite3 Cursor9717288
Ref: 2d4a9717288
Ref: library/sqlite3 sqlite3 Cursor execute9717400
Ref: 5b09717400
Ref: library/sqlite3 sqlite3 Cursor executemany9718890
Ref: 5b19718890
Ref: library/sqlite3 sqlite3 Cursor executescript9720406
Ref: 2d819720406
Ref: library/sqlite3 sqlite3 Cursor fetchone9721252
Ref: 2d4b9721252
Ref: library/sqlite3 sqlite3 Cursor fetchmany9721532
Ref: 178f9721532
Ref: library/sqlite3 sqlite3 Cursor fetchall9722494
Ref: 2d4e9722494
Ref: library/sqlite3 sqlite3 Cursor close9722775
Ref: 2d8d9722775
Ref: library/sqlite3 sqlite3 Cursor setinputsizes9723079
Ref: 2d8e9723079
Ref: library/sqlite3 sqlite3 Cursor setoutputsize9723188
Ref: 2d8f9723188
Ref: library/sqlite3 sqlite3 Cursor arraysize9723309
Ref: 17909723309
Ref: library/sqlite3 sqlite3 Cursor connection9723654
Ref: 2d909723654
Ref: library/sqlite3 sqlite3 Cursor description9724156
Ref: 18939724156
Ref: library/sqlite3 sqlite3 Cursor lastrowid9724532
Ref: ece9724532
Ref: library/sqlite3 sqlite3 Cursor rowcount9725230
Ref: 1b489725230
Ref: library/sqlite3 sqlite3 Cursor row_factory9725788
Ref: 2d889725788
Ref: library/sqlite3 sqlite3-columns-by-name9726574
Ref: 2d919726574
Ref: Cursor objects-Footnote-19726610
Ref: Cursor objects-Footnote-29726667
Node: Row objects9726718
Ref: library/sqlite3 row-objects9726819
Ref: 2d929726819
Ref: library/sqlite3 sqlite3-row-objects9726819
Ref: 2d939726819
Ref: library/sqlite3 sqlite3 Row9726862
Ref: 10739726862
Ref: library/sqlite3 sqlite3 Row keys9727314
Ref: 2d949727314
Node: Blob objects9727597
Ref: library/sqlite3 blob-objects9727707
Ref: 2d959727707
Ref: library/sqlite3 sqlite3-blob-objects9727707
Ref: 2d969727707
Ref: library/sqlite3 sqlite3 Blob9727752
Ref: 8939727752
Ref: library/sqlite3 sqlite3 Blob close9728923
Ref: 2d979728923
Ref: library/sqlite3 sqlite3 Blob read9729173
Ref: 2d989729173
Ref: library/sqlite3 sqlite3 Blob write9729529
Ref: 2d999729529
Ref: library/sqlite3 sqlite3 Blob tell9729758
Ref: 2d9a9729758
Ref: library/sqlite3 sqlite3 Blob seek9729843
Ref: 2d9b9729843
Node: PrepareProtocol objects9730267
Ref: library/sqlite3 prepareprotocol-objects9730379
Ref: 2d9c9730379
Ref: library/sqlite3 sqlite3 PrepareProtocol9730446
Ref: 1b539730446
Ref: PrepareProtocol objects-Footnote-19730716
Node: Exceptions<6>9730758
Ref: library/sqlite3 exceptions9730881
Ref: 2d9e9730881
Ref: library/sqlite3 sqlite3-exceptions9730881
Ref: 2d9f9730881
Ref: library/sqlite3 sqlite3 Warning9730993
Ref: 1b9e9730993
Ref: library/sqlite3 sqlite3 Error9731294
Ref: 1c0d9731294
Ref: library/sqlite3 sqlite3 Error sqlite_errorcode9731650
Ref: 8899731650
Ref: library/sqlite3 sqlite3 Error sqlite_errorname9731779
Ref: 88a9731779
Ref: library/sqlite3 sqlite3 InterfaceError9731939
Ref: 88e9731939
Ref: library/sqlite3 sqlite3 DatabaseError9732218
Ref: 2d859732218
Ref: library/sqlite3 sqlite3 DataError9732533
Ref: 1c399732533
Ref: library/sqlite3 sqlite3 OperationalError9732782
Ref: 1c3a9732782
Ref: library/sqlite3 sqlite3 IntegrityError9733136
Ref: 2da09733136
Ref: library/sqlite3 sqlite3 InternalError9733348
Ref: 2da19733348
Ref: library/sqlite3 sqlite3 ProgrammingError9733624
Ref: 3059733624
Ref: library/sqlite3 sqlite3 NotSupportedError9733932
Ref: 2d839733932
Ref: Exceptions<6>-Footnote-19734365
Ref: Exceptions<6>-Footnote-29734407
Ref: Exceptions<6>-Footnote-39734447
Node: SQLite and Python types9734487
Ref: library/sqlite3 sqlite-and-python-types9734629
Ref: 2da29734629
Ref: library/sqlite3 sqlite3-types9734629
Ref: 2d569734629
Node: Default adapters and converters deprecated9736541
Ref: library/sqlite3 default-adapters-and-converters-deprecated9736695
Ref: 2da39736695
Ref: library/sqlite3 sqlite3-default-converters9736695
Ref: 7159736695
Ref: Default adapters and converters deprecated-Footnote-19737916
Node: Command-line interface<2>9737963
Ref: library/sqlite3 command-line-interface9738085
Ref: 2da49738085
Ref: library/sqlite3 sqlite3-cli9738085
Ref: 6749738085
Ref: library/sqlite3 cmdoption-python-m-sqlite3-h-v-filename-sql-h9738435
Ref: 2da59738435
Ref: library/sqlite3 cmdoption-python-m-sqlite3-h-v-filename-sql-help9738435
Ref: 2da69738435
Ref: library/sqlite3 cmdoption-python-m-sqlite3-h-v-filename-sql-v9738481
Ref: 2da79738481
Ref: library/sqlite3 cmdoption-python-m-sqlite3-h-v-filename-sql-version9738481
Ref: 2da89738481
Node: How-to guides9738579
Ref: library/sqlite3 how-to-guides9738720
Ref: 2da99738720
Ref: library/sqlite3 sqlite3-howtos9738720
Ref: 2d469738720
Node: How to use placeholders to bind values in SQL queries9739186
Ref: library/sqlite3 how-to-use-placeholders-to-bind-values-in-sql-queries9739347
Ref: 2daa9739347
Ref: library/sqlite3 sqlite3-placeholders9739347
Ref: 5b29739347
Ref: How to use placeholders to bind values in SQL queries-Footnote-19741600
Ref: How to use placeholders to bind values in SQL queries-Footnote-29741652
Node: How to adapt custom Python types to SQLite values9741694
Ref: library/sqlite3 how-to-adapt-custom-python-types-to-sqlite-values9741915
Ref: 2dab9741915
Ref: library/sqlite3 sqlite3-adapters9741915
Ref: 2d4f9741915
Node: How to write adaptable objects9742704
Ref: library/sqlite3 how-to-write-adaptable-objects9742862
Ref: 2dac9742862
Ref: library/sqlite3 sqlite3-conform9742862
Ref: 2d9d9742862
Node: How to register adapter callables9743773
Ref: library/sqlite3 how-to-register-adapter-callables9743931
Ref: 2dad9743931
Node: How to convert SQLite values to custom Python types9744575
Ref: library/sqlite3 how-to-convert-sqlite-values-to-custom-python-types9744772
Ref: 2dae9744772
Ref: library/sqlite3 sqlite3-converters9744772
Ref: 2d509744772
Node: Adapter and converter recipes9747343
Ref: library/sqlite3 adapter-and-converter-recipes9747529
Ref: 2daf9747529
Ref: library/sqlite3 sqlite3-adapter-converter-recipes9747529
Ref: 7169747529
Node: How to use connection shortcut methods9748986
Ref: library/sqlite3 how-to-use-connection-shortcut-methods9749162
Ref: 2db09749162
Ref: library/sqlite3 sqlite3-connection-shortcuts9749162
Ref: 2d7c9749162
Node: How to use the connection context manager9750446
Ref: library/sqlite3 how-to-use-the-connection-context-manager9750621
Ref: 2db19750621
Ref: library/sqlite3 sqlite3-connection-context-manager9750621
Ref: 1b549750621
Node: How to work with SQLite URIs9752372
Ref: library/sqlite3 how-to-work-with-sqlite-uris9752544
Ref: 2db29752544
Ref: library/sqlite3 sqlite3-uri-tricks9752544
Ref: 2d5d9752544
Ref: How to work with SQLite URIs-Footnote-19753847
Node: How to create and use row factories9753887
Ref: library/sqlite3 how-to-create-and-use-row-factories9754056
Ref: 2db39754056
Ref: library/sqlite3 sqlite3-howto-row-factory9754056
Ref: 2d519754056
Node: How to handle non-UTF-8 text encodings9756917
Ref: library/sqlite3 how-to-handle-non-utf-8-text-encodings9757049
Ref: 2db49757049
Ref: library/sqlite3 sqlite3-howto-encoding9757049
Ref: 2d869757049
Ref: How to handle non-UTF-8 text encodings-Footnote-19758393
Node: Explanation9758442
Ref: library/sqlite3 explanation9758565
Ref: 2db59758565
Ref: library/sqlite3 sqlite3-explanation9758565
Ref: 2d479758565
Ref: library/sqlite3 sqlite3-transaction-control9758610
Ref: 2db69758610
Node: Transaction control9758644
Ref: library/sqlite3 sqlite3-controlling-transactions9758711
Ref: 2d4c9758711
Ref: library/sqlite3 transaction-control9758711
Ref: 2db79758711
Node: Transaction control via the autocommit attribute9759204
Ref: library/sqlite3 sqlite3-transaction-control-autocommit9759370
Ref: 6df9759370
Ref: library/sqlite3 transaction-control-via-the-autocommit-attribute9759370
Ref: 2db89759370
Ref: Transaction control via the autocommit attribute-Footnote-19761129
Ref: Transaction control via the autocommit attribute-Footnote-29761171
Ref: Transaction control via the autocommit attribute-Footnote-39761263
Node: Transaction control via the isolation_level attribute9761305
Ref: library/sqlite3 sqlite3-transaction-control-isolation-level9761471
Ref: 2d5b9761471
Ref: library/sqlite3 transaction-control-via-the-isolation-level-attribute9761471
Ref: 2db99761471
Ref: Transaction control via the isolation_level attribute-Footnote-19763562
Ref: Transaction control via the isolation_level attribute-Footnote-29763662
Node: Data Compression and Archiving9763754
Ref: library/archiving doc9763894
Ref: 2cef9763894
Ref: library/archiving archiving9763894
Ref: 2dba9763894
Ref: library/archiving data-compression-and-archiving9763894
Ref: 2dbb9763894
Ref: library/archiving translation-repo9763894
Ref: 2dbc9763894
Node: The compression package9764666
Ref: library/compression doc9764834
Ref: 2dbd9764834
Ref: library/compression module-compression9764834
Ref: 229764834
Ref: library/compression the-compression-package9764834
Ref: 2dbe9764834
Node: compression zstd — Compression compatible with the Zstandard format9765690
Ref: library/compression zstd doc9765908
Ref: 2dbf9765908
Ref: library/compression zstd compression-zstd-compression-compatible-with-the-zstandard-format9765908
Ref: 2dc09765908
Ref: library/compression zstd module-compression zstd9765908
Ref: 239765908
Ref: library/compression zstd translation-repo9765908
Ref: 2dc19765908
Ref: compression zstd — Compression compatible with the Zstandard format-Footnote-19767969
Ref: compression zstd — Compression compatible with the Zstandard format-Footnote-29768055
Node: Exceptions<7>9768122
Ref: library/compression zstd exceptions9768286
Ref: 2dce9768286
Ref: library/compression zstd compression zstd ZstdError9768327
Ref: 2dcf9768327
Node: Reading and writing compressed files9768512
Ref: library/compression zstd reading-and-writing-compressed-files9768729
Ref: 2dd09768729
Ref: library/compression zstd compression zstd open9768822
Ref: 2dc29768822
Ref: library/compression zstd compression zstd ZstdFile9771020
Ref: 2dc39771020
Ref: library/compression zstd compression zstd ZstdFile peek9773211
Ref: 2dd29773211
Ref: library/compression zstd compression zstd ZstdFile mode9773835
Ref: 2dd39773835
Ref: library/compression zstd compression zstd ZstdFile name9773923
Ref: 2dd49773923
Node: Compressing and decompressing data in memory9774092
Ref: library/compression zstd compressing-and-decompressing-data-in-memory9774318
Ref: 2dd69774318
Ref: library/compression zstd compression zstd compress9774427
Ref: 2dc69774427
Ref: library/compression zstd compression zstd decompress9775644
Ref: 2dc79775644
Ref: library/compression zstd compression zstd ZstdCompressor9776472
Ref: 2dc49776472
Ref: library/compression zstd compression zstd ZstdCompressor compress9777791
Ref: 2dd99777791
Ref: library/compression zstd compression zstd ZstdCompressor flush9778825
Ref: 2dda9778825
Ref: library/compression zstd compression zstd ZstdCompressor set_pledged_input_size9779205
Ref: 2dde9779205
Ref: library/compression zstd compression zstd ZstdCompressor CONTINUE9780505
Ref: 2ddb9780505
Ref: library/compression zstd compression zstd ZstdCompressor FLUSH_BLOCK9780758
Ref: 2ddc9780758
Ref: library/compression zstd compression zstd ZstdCompressor FLUSH_FRAME9781059
Ref: 2ddd9781059
Ref: library/compression zstd compression zstd ZstdCompressor last_mode9781271
Ref: 2de09781271
Ref: library/compression zstd compression zstd ZstdDecompressor9781641
Ref: 2dc59781641
Ref: library/compression zstd compression zstd ZstdDecompressor decompress9782851
Ref: 2de19782851
Ref: library/compression zstd compression zstd ZstdDecompressor eof9784143
Ref: 2de49784143
Ref: library/compression zstd compression zstd ZstdDecompressor unused_data9784236
Ref: 2de39784236
Ref: library/compression zstd compression zstd ZstdDecompressor needs_input9784407
Ref: 2de29784407
Node: Zstandard dictionaries9784587
Ref: library/compression zstd zstandard-dictionaries9784803
Ref: 2de59784803
Ref: library/compression zstd compression zstd train_dict9784868
Ref: 2dc89784868
Ref: library/compression zstd compression zstd finalize_dict9785960
Ref: 2dc99785960
Ref: library/compression zstd compression zstd ZstdDict9787104
Ref: 2dca9787104
Ref: library/compression zstd compression zstd ZstdDict dict_content9790404
Ref: 2de69790404
Ref: library/compression zstd compression zstd ZstdDict dict_id9790718
Ref: 2de79790718
Ref: library/compression zstd compression zstd ZstdDict as_digested_dict9791338
Ref: 2de99791338
Ref: library/compression zstd compression zstd ZstdDict as_undigested_dict9791428
Ref: 2dea9791428
Node: Advanced parameter control9791523
Ref: library/compression zstd advanced-parameter-control9791711
Ref: 2deb9791711
Ref: library/compression zstd compression zstd CompressionParameter9791784
Ref: 2dcb9791784
Ref: library/compression zstd compression zstd CompressionParameter bounds9792609
Ref: 2dd89792609
Ref: library/compression zstd compression zstd CompressionParameter compression_level9793077
Ref: 2dd79793077
Ref: library/compression zstd compression zstd CompressionParameter window_log9793645
Ref: 2dec9793645
Ref: library/compression zstd compression zstd CompressionParameter hash_log9794083
Ref: 2dee9794083
Ref: library/compression zstd compression zstd CompressionParameter chain_log9794494
Ref: 2df09794494
Ref: library/compression zstd compression zstd CompressionParameter search_log9795012
Ref: 2df29795012
Ref: library/compression zstd compression zstd CompressionParameter min_match9795345
Ref: 2df39795345
Ref: library/compression zstd compression zstd CompressionParameter target_length9795914
Ref: 2df59795914
Ref: library/compression zstd compression zstd CompressionParameter strategy9796569
Ref: 2df89796569
Ref: library/compression zstd compression zstd CompressionParameter enable_long_distance_matching9796869
Ref: 2df99796869
Ref: library/compression zstd compression zstd CompressionParameter ldm_hash_log9797549
Ref: 2dfa9797549
Ref: library/compression zstd compression zstd CompressionParameter ldm_min_match9797845
Ref: 2dfb9797845
Ref: library/compression zstd compression zstd CompressionParameter ldm_bucket_size_log9798091
Ref: 2dfc9798091
Ref: library/compression zstd compression zstd CompressionParameter ldm_hash_rate_log9798403
Ref: 2dfd9798403
Ref: library/compression zstd compression zstd CompressionParameter content_size_flag9798774
Ref: 2ddf9798774
Ref: library/compression zstd compression zstd CompressionParameter checksum_flag9799907
Ref: 2dfe9799907
Ref: library/compression zstd compression zstd CompressionParameter dict_id_flag9800322
Ref: 2dff9800322
Ref: library/compression zstd compression zstd CompressionParameter nb_workers9800596
Ref: 2e009800596
Ref: library/compression zstd compression zstd CompressionParameter job_size9801021
Ref: 2e019801021
Ref: library/compression zstd compression zstd CompressionParameter overlap_log9801381
Ref: 2e029801381
Ref: library/compression zstd compression zstd DecompressionParameter9802039
Ref: 2dcc9802039
Ref: library/compression zstd compression zstd DecompressionParameter bounds9802773
Ref: 2e039802773
Ref: library/compression zstd compression zstd DecompressionParameter window_log_max9803057
Ref: 2e049803057
Ref: library/compression zstd compression zstd Strategy9803433
Ref: 2dcd9803433
Ref: library/compression zstd compression zstd Strategy fast9803913
Ref: 2df19803913
Ref: library/compression zstd compression zstd Strategy dfast9803939
Ref: 2def9803939
Ref: library/compression zstd compression zstd Strategy greedy9803966
Ref: 2e059803966
Ref: library/compression zstd compression zstd Strategy lazy9803994
Ref: 2e069803994
Ref: library/compression zstd compression zstd Strategy lazy29804020
Ref: 2e079804020
Ref: library/compression zstd compression zstd Strategy btlazy29804047
Ref: 2e089804047
Ref: library/compression zstd compression zstd Strategy btopt9804076
Ref: 2df49804076
Ref: library/compression zstd compression zstd Strategy btultra9804103
Ref: 2df69804103
Ref: library/compression zstd compression zstd Strategy btultra29804132
Ref: 2df79804132
Node: Miscellaneous<2>9804162
Ref: library/compression zstd miscellaneous9804339
Ref: 2e099804339
Ref: library/compression zstd compression zstd get_frame_info9804386
Ref: 2de89804386
Ref: library/compression zstd compression zstd FrameInfo9804617
Ref: 2e0a9804617
Ref: library/compression zstd compression zstd FrameInfo decompressed_size9804702
Ref: 2e0b9804702
Ref: library/compression zstd compression zstd FrameInfo dictionary_id9804804
Ref: 2e0c9804804
Ref: library/compression zstd compression zstd COMPRESSION_LEVEL_DEFAULT9805165
Ref: 2ded9805165
Ref: library/compression zstd compression zstd zstd_version_info9805284
Ref: 2e0d9805284
Node: Examples<8>9805437
Ref: library/compression zstd examples9805579
Ref: 2e0e9805579
Node: zlib — Compression compatible with gzip9806999
Ref: library/zlib doc9807225
Ref: 2e0f9807225
Ref: library/zlib module-zlib9807225
Ref: 1399807225
Ref: library/zlib translation-repo9807225
Ref: 2e109807225
Ref: library/zlib zlib-compression-compatible-with-gzip9807225
Ref: 2e119807225
Ref: library/zlib zlib error9808151
Ref: 2e129808151
Ref: library/zlib zlib adler329808242
Ref: 1ba29808242
Ref: library/zlib zlib compress9809031
Ref: 8509809031
Ref: library/zlib compress-wbits9809571
Ref: 2e179809571
Ref: library/zlib zlib compressobj9810821
Ref: 2e199810821
Ref: library/zlib zlib crc329812690
Ref: 19f89812690
Ref: library/zlib zlib decompress9813396
Ref: f0b9813396
Ref: library/zlib decompress-wbits9813829
Ref: 2e209813829
Ref: library/zlib zlib decompressobj9815567
Ref: 2e219815567
Ref: library/zlib zlib Compress compress9816569
Ref: 2e229816569
Ref: library/zlib zlib Compress flush9816927
Ref: 2e239816927
Ref: library/zlib zlib Compress copy9817733
Ref: 2e2a9817733
Ref: library/zlib zlib Decompress unused_data9818106
Ref: 2e2b9818106
Ref: library/zlib zlib Decompress unconsumed_tail9818452
Ref: 2e2c9818452
Ref: library/zlib zlib Decompress eof9818906
Ref: 13759818906
Ref: library/zlib zlib Decompress decompress9819191
Ref: 2e2d9819191
Ref: library/zlib zlib Decompress flush9820223
Ref: 2e2e9820223
Ref: library/zlib zlib Decompress copy9820628
Ref: 2e2f9820628
Ref: library/zlib zlib DEFLATED9821099
Ref: 2e1a9821099
Ref: library/zlib zlib MAX_WBITS9821162
Ref: 2e189821162
Ref: library/zlib zlib DEF_MEM_LEVEL9821341
Ref: 2e309821341
Ref: library/zlib zlib DEF_BUF_SIZE9821427
Ref: 2e319821427
Ref: library/zlib zlib Z_NO_COMPRESSION9821516
Ref: 2e159821516
Ref: library/zlib zlib Z_BEST_SPEED9821626
Ref: 2e139821626
Ref: library/zlib zlib Z_BEST_COMPRESSION9821732
Ref: 2e149821732
Ref: library/zlib zlib Z_DEFAULT_COMPRESSION9821843
Ref: 2e169821843
Ref: library/zlib zlib Z_DEFAULT_STRATEGY9822026
Ref: 2e1b9822026
Ref: library/zlib zlib Z_FILTERED9822114
Ref: 2e1c9822114
Ref: library/zlib zlib Z_HUFFMAN_ONLY9822214
Ref: 2e1d9822214
Ref: library/zlib zlib Z_RLE9822305
Ref: 2e1e9822305
Ref: library/zlib zlib Z_FIXED9822541
Ref: 2e1f9822541
Ref: library/zlib zlib Z_NO_FLUSH9822769
Ref: 2e249822769
Ref: library/zlib zlib Z_PARTIAL_FLUSH9822881
Ref: 2e259822881
Ref: library/zlib zlib Z_SYNC_FLUSH9822974
Ref: 2e269822974
Ref: library/zlib zlib Z_FULL_FLUSH9823103
Ref: 2e279823103
Ref: library/zlib zlib Z_FINISH9823222
Ref: 2e299823222
Ref: library/zlib zlib Z_BLOCK9823338
Ref: 2e289823338
Ref: library/zlib zlib Z_TREES9823555
Ref: 2e329823555
Ref: library/zlib zlib ZLIB_VERSION9823940
Ref: 2e339823940
Ref: library/zlib zlib ZLIB_RUNTIME_VERSION9824195
Ref: 13769824195
Ref: library/zlib zlib ZLIBNG_VERSION9824346
Ref: 2e349824346
Ref: zlib — Compression compatible with gzip-Footnote-19825225
Ref: zlib — Compression compatible with gzip-Footnote-29825254
Ref: zlib — Compression compatible with gzip-Footnote-39825295
Node: gzip — Support for gzip files9825348
Ref: library/gzip doc9825542
Ref: 2e359825542
Ref: library/gzip gzip-support-for-gzip-files9825542
Ref: 2e369825542
Ref: library/gzip module-gzip9825542
Ref: 6b9825542
Ref: library/gzip translation-repo9825542
Ref: 2e379825542
Ref: library/gzip gzip open9826793
Ref: 2e389826793
Ref: library/gzip gzip BadGzipFile9828340
Ref: bec9828340
Ref: library/gzip gzip GzipFile9828593
Ref: 65c9828593
Ref: library/gzip gzip GzipFile peek9831656
Ref: 14149831656
Ref: library/gzip gzip GzipFile mode9832194
Ref: 2e3b9832194
Ref: library/gzip gzip GzipFile mtime9832392
Ref: 2e399832392
Ref: library/gzip gzip GzipFile name9832732
Ref: 7329832732
Ref: library/gzip gzip compress9834003
Ref: 84f9834003
Ref: library/gzip gzip decompress9835206
Ref: 14159835206
Ref: gzip — Support for gzip files-Footnote-19835896
Node: Examples of usage9835960
Ref: library/gzip examples-of-usage9836079
Ref: 2e3d9836079
Ref: library/gzip gzip-usage-examples9836079
Ref: 2e3e9836079
Ref: Examples of usage-Footnote-19837167
Node: Command-line interface<3>9837220
Ref: library/gzip command-line-interface9837339
Ref: 2e3f9837339
Ref: library/gzip gzip-cli9837339
Ref: 2e409837339
Node: Command-line options9837765
Ref: library/gzip command-line-options9837847
Ref: 2e419837847
Ref: library/gzip cmdoption-gzip-arg-file9837908
Ref: 2e429837908
Ref: library/gzip cmdoption-gzip-fast9837992
Ref: 2e439837992
Ref: library/gzip cmdoption-gzip-best9838079
Ref: 2e449838079
Ref: library/gzip cmdoption-gzip-d9838166
Ref: 2e459838166
Ref: library/gzip cmdoption-gzip-decompress9838166
Ref: 2e469838166
Ref: library/gzip cmdoption-gzip-h9838229
Ref: 2e479838229
Ref: library/gzip cmdoption-gzip-help9838229
Ref: 2e489838229
Node: bz2 — Support for bzip2 compression9838282
Ref: library/bz2 doc9838480
Ref: 2e499838480
Ref: library/bz2 bz2-support-for-bzip2-compression9838480
Ref: 2e4a9838480
Ref: library/bz2 module-bz29838480
Ref: 149838480
Ref: library/bz2 translation-repo9838480
Ref: 2e4b9838480
Ref: bz2 — Support for bzip2 compression-Footnote-19839695
Node: De compression of files9839758
Ref: library/bz2 de-compression-of-files9839890
Ref: 2e4c9839890
Ref: library/bz2 bz2 open9839959
Ref: 12959839959
Ref: library/bz2 bz2 BZ2File9841410
Ref: a689841410
Ref: library/bz2 bz2 BZ2File peek9842884
Ref: 2e4d9842884
Ref: library/bz2 bz2 BZ2File fileno9843472
Ref: 2e4e9843472
Ref: library/bz2 bz2 BZ2File readable9843596
Ref: 2e4f9843596
Ref: library/bz2 bz2 BZ2File seekable9843718
Ref: 2e509843718
Ref: library/bz2 bz2 BZ2File writable9843834
Ref: 2e519843834
Ref: library/bz2 bz2 BZ2File read19843956
Ref: 2e529843956
Ref: library/bz2 bz2 BZ2File readinto9844277
Ref: 2e539844277
Ref: library/bz2 bz2 BZ2File mode9844430
Ref: 2e549844430
Ref: library/bz2 bz2 BZ2File name9844552
Ref: 2e559844552
Node: Incremental de compression9845833
Ref: library/bz2 incremental-de-compression9845997
Ref: 2e569845997
Ref: library/bz2 bz2 BZ2Compressor9846072
Ref: 1ab69846072
Ref: library/bz2 bz2 BZ2Compressor compress9846413
Ref: 2e579846413
Ref: library/bz2 bz2 BZ2Compressor flush9846761
Ref: 2e589846761
Ref: library/bz2 bz2 BZ2Decompressor9846990
Ref: 1ab49846990
Ref: library/bz2 bz2 BZ2Decompressor decompress9847544
Ref: fcc9847544
Ref: library/bz2 bz2 BZ2Decompressor eof9848916
Ref: 2e5b9848916
Ref: library/bz2 bz2 BZ2Decompressor unused_data9849042
Ref: 2e5a9849042
Ref: library/bz2 bz2 BZ2Decompressor needs_input9849264
Ref: 2e599849264
Node: One-shot de compression9849488
Ref: library/bz2 one-shot-de-compression9849649
Ref: 2e5c9849649
Ref: library/bz2 bz2 compress9849718
Ref: 28619849718
Ref: library/bz2 bz2 decompress9850017
Ref: 12969850017
Node: Examples of usage<2>9850385
Ref: library/bz2 bz2-usage-examples9850511
Ref: 2e5d9850511
Ref: library/bz2 examples-of-usage9850511
Ref: 2e5e9850511
Node: lzma — Compression using the LZMA algorithm9853444
Ref: library/lzma doc9853645
Ref: 2e5f9853645
Ref: library/lzma lzma-compression-using-the-lzma-algorithm9853645
Ref: 2e609853645
Ref: library/lzma module-lzma9853645
Ref: 8e9853645
Ref: library/lzma translation-repo9853645
Ref: 2e619853645
Ref: library/lzma lzma LZMAError9854733
Ref: 2e629854733
Ref: lzma — Compression using the LZMA algorithm-Footnote-19855240
Node: Reading and writing compressed files<2>9855304
Ref: library/lzma reading-and-writing-compressed-files9855481
Ref: 2e639855481
Ref: library/lzma lzma open9855574
Ref: 2e649855574
Ref: library/lzma lzma LZMAFile9857354
Ref: 120e9857354
Ref: library/lzma lzma LZMAFile peek9859276
Ref: 2e659859276
Ref: library/lzma lzma LZMAFile mode9859896
Ref: 2e669859896
Ref: library/lzma lzma LZMAFile name9860018
Ref: 2e679860018
Node: Compressing and decompressing data in memory<2>9860487
Ref: library/lzma compressing-and-decompressing-data-in-memory9860689
Ref: 2e689860689
Ref: library/lzma lzma LZMACompressor9860798
Ref: 1ab59860798
Ref: library/lzma lzma LZMACompressor compress9863877
Ref: 2e6b9863877
Ref: library/lzma lzma LZMACompressor flush9864350
Ref: 2e6c9864350
Ref: library/lzma lzma LZMADecompressor9864630
Ref: 1ab39864630
Ref: library/lzma lzma LZMADecompressor decompress9866160
Ref: 10309866160
Ref: library/lzma lzma LZMADecompressor check9867533
Ref: 2e709867533
Ref: library/lzma lzma LZMADecompressor eof9867766
Ref: 2e719867766
Ref: library/lzma lzma LZMADecompressor unused_data9867859
Ref: 2e6f9867859
Ref: library/lzma lzma LZMADecompressor needs_input9868030
Ref: 2e6e9868030
Ref: library/lzma lzma compress9868255
Ref: 2e699868255
Ref: library/lzma lzma decompress9868601
Ref: 2e6d9868601
Node: Miscellaneous<3>9869108
Ref: library/lzma miscellaneous9869302
Ref: 2e729869302
Ref: library/lzma lzma is_check_supported9869349
Ref: 2e739869349
Node: Specifying custom filter chains9869711
Ref: library/lzma filter-chain-specs9869869
Ref: 2e6a9869869
Ref: library/lzma specifying-custom-filter-chains9869869
Ref: 2e749869869
Node: Examples<9>9872552
Ref: library/lzma examples9872685
Ref: 2e759872685
Node: zipfile — Work with ZIP archives9874053
Ref: library/zipfile doc9874261
Ref: 2e769874261
Ref: library/zipfile module-zipfile9874261
Ref: 1379874261
Ref: library/zipfile translation-repo9874261
Ref: 2e779874261
Ref: library/zipfile zipfile-work-with-zip-archives9874261
Ref: 2e789874261
Ref: library/zipfile zipfile BadZipFile9875482
Ref: 1b509875482
Ref: library/zipfile zipfile BadZipfile9875587
Ref: 2e799875587
Ref: library/zipfile zipfile LargeZipFile9875748
Ref: 2e7a9875748
Ref: library/zipfile zipfile ZipInfo9876377
Ref: 2cb9876377
Ref: library/zipfile zipfile ZipInfo _for_archive9877323
Ref: 2ca9877323
Ref: library/zipfile zipfile is_zipfile9877601
Ref: 15329877601
Ref: library/zipfile zipfile ZIP_STORED9877904
Ref: 2e7f9877904
Ref: library/zipfile zipfile ZIP_DEFLATED9877997
Ref: 2e809877997
Ref: library/zipfile zipfile ZIP_BZIP29878143
Ref: 2e819878143
Ref: library/zipfile zipfile ZIP_LZMA9878308
Ref: 2e829878308
Ref: library/zipfile zipfile ZIP_ZSTANDARD9878472
Ref: 2e839878472
Ref: zipfile — Work with ZIP archives-Footnote-19879899
Ref: zipfile — Work with ZIP archives-Footnote-29879964
Ref: zipfile — Work with ZIP archives-Footnote-39880032
Ref: zipfile — Work with ZIP archives-Footnote-49880100
Node: ZipFile objects9880141
Ref: library/zipfile id19880248
Ref: 2e849880248
Ref: library/zipfile zipfile-objects9880248
Ref: 2e7b9880248
Ref: library/zipfile zipfile ZipFile9880299
Ref: 8d49880299
Ref: library/zipfile zipfile ZipFile close9885667
Ref: 2e859885667
Ref: library/zipfile zipfile ZipFile getinfo9885838
Ref: 2e7c9885838
Ref: library/zipfile zipfile ZipFile infolist9886097
Ref: 2e7d9886097
Ref: library/zipfile zipfile ZipFile namelist9886355
Ref: 2e869886355
Ref: library/zipfile zipfile ZipFile open9886436
Ref: 65d9886436
Ref: library/zipfile zipfile ZipFile extract9889348
Ref: 2e899889348
Ref: library/zipfile zipfile ZipFile extractall9890747
Ref: 2e8a9890747
Ref: library/zipfile zipfile ZipFile printdir9891810
Ref: 2e8b9891810
Ref: library/zipfile zipfile ZipFile setpassword9891912
Ref: 2e8c9891912
Ref: library/zipfile zipfile ZipFile read9892049
Ref: 2e889892049
Ref: library/zipfile zipfile ZipFile testzip9893013
Ref: 2e8d9893013
Ref: library/zipfile zipfile ZipFile write9893388
Ref: f4b9893388
Ref: library/zipfile zipfile ZipFile writestr9895198
Ref: 2cc9895198
Ref: library/zipfile zipfile ZipFile mkdir9896797
Ref: 8d59896797
Ref: library/zipfile zipfile ZipFile filename9897320
Ref: 2e8e9897320
Ref: library/zipfile zipfile ZipFile debug9897381
Ref: 2e8f9897381
Ref: library/zipfile zipfile ZipFile comment9897601
Ref: 2e909897601
Node: Path objects9897924
Ref: library/zipfile id29898057
Ref: 2e919898057
Ref: library/zipfile path-objects9898057
Ref: 2e929898057
Ref: library/zipfile zipfile Path9898102
Ref: 8d99898102
Ref: library/zipfile zipfile Path name9899282
Ref: 2e939899282
Ref: library/zipfile zipfile Path open9899340
Ref: 18ef9899340
Ref: library/zipfile zipfile Path iterdir9900248
Ref: 2e949900248
Ref: library/zipfile zipfile Path is_dir9900332
Ref: 2e959900332
Ref: library/zipfile zipfile Path is_file9900431
Ref: 2e969900431
Ref: library/zipfile zipfile Path is_symlink9900526
Ref: 2e979900526
Ref: library/zipfile zipfile Path exists9900774
Ref: 2e989900774
Ref: library/zipfile zipfile Path suffix9900902
Ref: 8d79900902
Ref: library/zipfile zipfile Path stem9901112
Ref: 8d69901112
Ref: library/zipfile zipfile Path suffixes9901252
Ref: 8d89901252
Ref: library/zipfile zipfile Path read_text9901420
Ref: 1ac69901420
Ref: library/zipfile zipfile Path read_bytes9902002
Ref: 2e999902002
Ref: library/zipfile zipfile Path joinpath9902072
Ref: 2e9a9902072
Ref: Path objects-Footnote-19902727
Node: PyZipFile objects9902766
Ref: library/zipfile id39902899
Ref: 2e9b9902899
Ref: library/zipfile pyzipfile-objects9902899
Ref: 2e9c9902899
Ref: library/zipfile zipfile PyZipFile9903102
Ref: 11fb9903102
Ref: library/zipfile zipfile PyZipFile writepy9903452
Ref: 11fa9903452
Node: ZipInfo objects9906336
Ref: library/zipfile id49906482
Ref: 2e9d9906482
Ref: library/zipfile zipinfo-objects9906482
Ref: 2e7e9906482
Ref: library/zipfile zipfile ZipInfo from_file9906850
Ref: f089906850
Ref: library/zipfile zipfile ZipInfo is_dir9907946
Ref: f099907946
Ref: library/zipfile zipfile ZipInfo filename9908148
Ref: 2e9e9908148
Ref: library/zipfile zipfile ZipInfo date_time9908220
Ref: 2e9f9908220
Ref: library/zipfile zipfile ZipInfo compress_type9909792
Ref: 2ea09909792
Ref: library/zipfile zipfile ZipInfo comment9909880
Ref: 2ea19909880
Ref: library/zipfile zipfile ZipInfo extra9909996
Ref: 2ea29909996
Ref: library/zipfile zipfile ZipInfo create_system9910200
Ref: 2ea39910200
Ref: library/zipfile zipfile ZipInfo create_version9910278
Ref: 2ea49910278
Ref: library/zipfile zipfile ZipInfo extract_version9910364
Ref: 2ea59910364
Ref: library/zipfile zipfile ZipInfo reserved9910451
Ref: 2ea69910451
Ref: library/zipfile zipfile ZipInfo flag_bits9910504
Ref: 2ea79910504
Ref: library/zipfile zipfile ZipInfo volume9910559
Ref: 2ea89910559
Ref: library/zipfile zipfile ZipInfo internal_attr9910626
Ref: 2ea99910626
Ref: library/zipfile zipfile ZipInfo external_attr9910691
Ref: 2eaa9910691
Ref: library/zipfile zipfile ZipInfo header_offset9910761
Ref: 2eab9910761
Ref: library/zipfile zipfile ZipInfo CRC9910837
Ref: 2eac9910837
Ref: library/zipfile zipfile ZipInfo compress_size9910904
Ref: 2ead9910904
Ref: library/zipfile zipfile ZipInfo file_size9910977
Ref: 2e879910977
Ref: ZipInfo objects-Footnote-19911084
Node: Command-line interface<4>9911152
Ref: library/zipfile command-line-interface9911303
Ref: 2eae9911303
Ref: library/zipfile zipfile-commandline9911303
Ref: 2eaf9911303
Node: Command-line options<2>9912100
Ref: library/zipfile command-line-options9912185
Ref: 2eb39912185
Ref: library/zipfile cmdoption-zipfile-l9912246
Ref: 2eb29912246
Ref: library/zipfile cmdoption-zipfile-list9912271
Ref: 2eb49912271
Ref: library/zipfile cmdoption-zipfile-c9912332
Ref: 2eb09912332
Ref: library/zipfile cmdoption-zipfile-create9912381
Ref: 2eb59912381
Ref: library/zipfile cmdoption-zipfile-e9912477
Ref: 2eb19912477
Ref: library/zipfile cmdoption-zipfile-extract9912515
Ref: 2eb69912515
Ref: library/zipfile cmdoption-zipfile-t9912606
Ref: 2eb79912606
Ref: library/zipfile cmdoption-zipfile-test9912631
Ref: 2eb89912631
Ref: library/zipfile cmdoption-zipfile-metadata-encoding9912709
Ref: 2eb99912709
Node: Decompression pitfalls9912882
Ref: library/zipfile decompression-pitfalls9913009
Ref: 2eba9913009
Node: From file itself9913292
Ref: library/zipfile from-file-itself9913399
Ref: 2ebb9913399
Node: File system limitations9913578
Ref: library/zipfile file-system-limitations9913715
Ref: 2ebc9913715
Node: Resources limitations9914017
Ref: library/zipfile resources-limitations9914150
Ref: 2ebd9914150
Ref: library/zipfile zipfile-resources-limitations9914150
Ref: 2ebe9914150
Ref: Resources limitations-Footnote-19914437
Node: Interruption9914484
Ref: library/zipfile interruption9914625
Ref: 2ebf9914625
Node: Default behaviors of extraction9914831
Ref: library/zipfile default-behaviors-of-extraction9914942
Ref: 2ec09914942
Node: tarfile — Read and write tar archive files9915207
Ref: library/tarfile doc9915361
Ref: 2ec19915361
Ref: library/tarfile module-tarfile9915361
Ref: e49915361
Ref: library/tarfile tarfile-read-and-write-tar-archive-files9915361
Ref: 2ec29915361
Ref: library/tarfile translation-repo9915361
Ref: 2ec39915361
Ref: library/tarfile tarfile open9917539
Ref: 10799917539
Ref: library/tarfile tarfile is_tarfile9925633
Ref: 1bc39925633
Ref: library/tarfile tarfile TarError9925997
Ref: 2ec89925997
Ref: library/tarfile tarfile ReadError9926086
Ref: 1c379926086
Ref: library/tarfile tarfile CompressionError9926257
Ref: 2ec69926257
Ref: library/tarfile tarfile StreamError9926407
Ref: 2ec99926407
Ref: library/tarfile tarfile ExtractError9926547
Ref: 2eca9926547
Ref: library/tarfile tarfile HeaderError9926728
Ref: 2ecb9926728
Ref: library/tarfile tarfile FilterError9926853
Ref: 2ecd9926853
Ref: library/tarfile tarfile FilterError tarinfo9926951
Ref: 2ecf9926951
Ref: library/tarfile tarfile AbsolutePathError9927090
Ref: 2ed19927090
Ref: library/tarfile tarfile OutsideDestinationError9927198
Ref: 2ed29927198
Ref: library/tarfile tarfile SpecialFileError9927329
Ref: 2ed39927329
Ref: library/tarfile tarfile AbsoluteLinkError9927450
Ref: 2ed49927450
Ref: library/tarfile tarfile LinkOutsideDestinationError9927565
Ref: 2ed59927565
Ref: library/tarfile tarfile LinkFallbackError9927716
Ref: 29d9927716
Ref: library/tarfile tarfile ENCODING9928131
Ref: 2ed69928131
Ref: library/tarfile tarfile REGTYPE9928301
Ref: 2ed79928301
Ref: library/tarfile tarfile AREGTYPE9928327
Ref: 2ed89928327
Ref: library/tarfile tarfile LNKTYPE9928394
Ref: 2eda9928394
Ref: library/tarfile tarfile SYMTYPE9928469
Ref: 2edb9928469
Ref: library/tarfile tarfile CHRTYPE9928536
Ref: 2edc9928536
Ref: library/tarfile tarfile BLKTYPE9928614
Ref: 2edd9928614
Ref: library/tarfile tarfile DIRTYPE9928688
Ref: 2ede9928688
Ref: library/tarfile tarfile FIFOTYPE9928751
Ref: 2edf9928751
Ref: library/tarfile tarfile CONTTYPE9928825
Ref: 2ee09928825
Ref: library/tarfile tarfile GNUTYPE_LONGNAME9928895
Ref: 2ee19928895
Ref: library/tarfile tarfile GNUTYPE_LONGLINK9928974
Ref: 2ee29928974
Ref: library/tarfile tarfile GNUTYPE_SPARSE9929053
Ref: 2ee39929053
Ref: library/tarfile tarfile USTAR_FORMAT9929310
Ref: 2ee59929310
Ref: library/tarfile tarfile GNU_FORMAT9929377
Ref: 2ee69929377
Ref: library/tarfile tarfile PAX_FORMAT9929429
Ref: 2ee79929429
Ref: library/tarfile tarfile DEFAULT_FORMAT9929492
Ref: 2ee89929492
Ref: tarfile — Read and write tar archive files-Footnote-19930350
Ref: tarfile — Read and write tar archive files-Footnote-29930417
Node: TarFile Objects9930489
Ref: library/tarfile id19930609
Ref: 2ee99930609
Ref: library/tarfile tarfile-objects9930609
Ref: 2ec59930609
Ref: library/tarfile tarfile TarFile9931482
Ref: 14189931482
Ref: library/tarfile tarfile TarFile open9934844
Ref: 1bc49934844
Ref: library/tarfile tarfile TarFile getmember9935010
Ref: 1bd89935010
Ref: library/tarfile tarfile TarFile getmembers9935334
Ref: 107b9935334
Ref: library/tarfile tarfile TarFile getnames9935522
Ref: 2eeb9935522
Ref: library/tarfile tarfile TarFile list9935684
Ref: 107a9935684
Ref: library/tarfile tarfile TarFile next9936140
Ref: 2eec9936140
Ref: library/tarfile tarfile TarFile extractall9936362
Ref: 29b9936362
Ref: library/tarfile tarfile TarFile extract9938304
Ref: 29c9938304
Ref: library/tarfile tarfile TarFile extractfile9939615
Ref: 2eed9939615
Ref: library/tarfile tarfile TarFile errorlevel9940290
Ref: 29e9940290
Ref: library/tarfile tarfile TarFile extraction_filter9941221
Ref: 2eee9941221
Ref: library/tarfile tarfile TarFile add9942503
Ref: df09942503
Ref: library/tarfile tarfile TarFile addfile9943427
Ref: 198f9943427
Ref: library/tarfile tarfile TarFile gettarinfo9943952
Ref: 2eef9943952
Ref: library/tarfile tarfile TarFile close9945101
Ref: 2ef29945101
Ref: library/tarfile tarfile TarFile pax_headers9945244
Ref: 2ef39945244
Node: TarInfo Objects9945367
Ref: library/tarfile id29945514
Ref: 2ef49945514
Ref: library/tarfile tarinfo-objects9945514
Ref: 2ed09945514
Ref: library/tarfile tarfile TarInfo9946727
Ref: 14199946727
Ref: library/tarfile tarfile TarInfo frombuf9946810
Ref: 2ecc9946810
Ref: library/tarfile tarfile TarInfo fromtarfile9947024
Ref: 2ef69947024
Ref: library/tarfile tarfile TarInfo tobuf9947206
Ref: 2ef79947206
Ref: library/tarfile tarfile TarInfo name9947652
Ref: 2ef19947652
Ref: library/tarfile tarfile TarInfo size9947732
Ref: 2ef09947732
Ref: library/tarfile tarfile TarInfo mtime9947799
Ref: 2ef89947799
Ref: library/tarfile tarfile TarInfo mode9948164
Ref: 2efb9948164
Ref: library/tarfile tarfile TarInfo type9948441
Ref: 2ed99948441
Ref: library/tarfile tarfile TarInfo linkname9948885
Ref: 2efc9948885
Ref: library/tarfile tarfile TarInfo uid9949297
Ref: 2efd9949297
Ref: library/tarfile tarfile TarInfo gid9949581
Ref: 2efe9949581
Ref: library/tarfile tarfile TarInfo uname9949866
Ref: 2eff9949866
Ref: library/tarfile tarfile TarInfo gname9950108
Ref: 2f009950108
Ref: library/tarfile tarfile TarInfo chksum9950351
Ref: 2f019950351
Ref: library/tarfile tarfile TarInfo devmajor9950422
Ref: 2f029950422
Ref: library/tarfile tarfile TarInfo devminor9950499
Ref: 2f039950499
Ref: library/tarfile tarfile TarInfo offset9950576
Ref: 2f049950576
Ref: library/tarfile tarfile TarInfo offset_data9950658
Ref: 2f059950658
Ref: library/tarfile tarfile TarInfo sparse9950748
Ref: 2f069950748
Ref: library/tarfile tarfile TarInfo pax_headers9950812
Ref: 2f079950812
Ref: library/tarfile tarfile TarInfo replace9950955
Ref: 2ef59950955
Ref: library/tarfile tarfile TarInfo isfile9951644
Ref: 2f089951644
Ref: library/tarfile tarfile TarInfo isreg9951764
Ref: 2f099951764
Ref: library/tarfile tarfile TarInfo isdir9951830
Ref: 2f0a9951830
Ref: library/tarfile tarfile TarInfo issym9951912
Ref: 2f0b9951912
Ref: library/tarfile tarfile TarInfo islnk9951998
Ref: 2f0c9951998
Ref: library/tarfile tarfile TarInfo ischr9952080
Ref: 2f0d9952080
Ref: library/tarfile tarfile TarInfo isblk9952169
Ref: 2f0e9952169
Ref: library/tarfile tarfile TarInfo isfifo9952254
Ref: 2f0f9952254
Ref: library/tarfile tarfile TarInfo isdev9952332
Ref: 2f109952332
Node: Extraction filters9952453
Ref: library/tarfile extraction-filters9952607
Ref: 2f119952607
Ref: library/tarfile tarfile-extraction-filter9952607
Ref: 6989952607
Ref: Extraction filters-Footnote-19955833
Node: Default named filters9955875
Ref: library/tarfile default-named-filters9955973
Ref: 2f139955973
Ref: library/tarfile tarfile fully_trusted_filter9956137
Ref: 2ec49956137
Ref: library/tarfile tarfile tar_filter9956285
Ref: 2f129956285
Ref: library/tarfile tarfile data_filter9957092
Ref: 29a9957092
Node: Filter errors9958947
Ref: library/tarfile filter-errors9959084
Ref: 2f149959084
Ref: library/tarfile tarfile-extraction-refuse9959084
Ref: 2ece9959084
Node: Hints for further verification9959444
Ref: library/tarfile hints-for-further-verification9959592
Ref: 2f159959592
Ref: library/tarfile tarfile-further-verification9959592
Ref: 2cda9959592
Node: Supporting older Python versions9961331
Ref: library/tarfile supporting-older-python-versions9961500
Ref: 2f169961500
Node: Stateful extraction filter example9963050
Ref: library/tarfile stateful-extraction-filter-example9963180
Ref: 2f179963180
Node: Command-Line Interface9963975
Ref: library/tarfile command-line-interface9964126
Ref: 2f189964126
Ref: library/tarfile tarfile-commandline9964126
Ref: 11cd9964126
Node: Command-line options<3>9965081
Ref: library/tarfile command-line-options9965163
Ref: 2f1c9965163
Ref: library/tarfile cmdoption-tarfile-l9965226
Ref: 2f1b9965226
Ref: library/tarfile cmdoption-tarfile-list9965251
Ref: 2f1d9965251
Ref: library/tarfile cmdoption-tarfile-c9965312
Ref: 2f199965312
Ref: library/tarfile cmdoption-tarfile-create9965361
Ref: 2f1e9965361
Ref: library/tarfile cmdoption-tarfile-e9965457
Ref: 2f1a9965457
Ref: library/tarfile cmdoption-tarfile-extract9965497
Ref: 2f1f9965497
Ref: library/tarfile cmdoption-tarfile-t9965633
Ref: 2f209965633
Ref: library/tarfile cmdoption-tarfile-test9965658
Ref: 2f219965658
Ref: library/tarfile cmdoption-tarfile-v9965736
Ref: 2f229965736
Ref: library/tarfile cmdoption-tarfile-verbose9965736
Ref: 2f239965736
Ref: library/tarfile cmdoption-tarfile-filter9965785
Ref: 2f249965785
Node: Examples<10>9966020
Ref: library/tarfile examples9966174
Ref: 2f259966174
Ref: library/tarfile tar-examples9966174
Ref: 2ec79966174
Node: Reading examples9966265
Ref: library/tarfile reading-examples9966355
Ref: 2f269966355
Node: Writing examples9967473
Ref: library/tarfile writing-examples9967563
Ref: 2f279967563
Node: Supported tar formats9968735
Ref: library/tarfile supported-tar-formats9968881
Ref: 2f289968881
Ref: library/tarfile tar-formats9968881
Ref: 2ee49968881
Node: Unicode issues9971103
Ref: library/tarfile tar-unicode9971228
Ref: 2eea9971228
Ref: library/tarfile unicode-issues9971228
Ref: 2f299971228
Node: File Formats9973203
Ref: library/fileformats doc9973349
Ref: 2f2b9973349
Ref: library/fileformats file-formats9973349
Ref: 2f2c9973349
Ref: library/fileformats fileformats9973349
Ref: 2f2d9973349
Ref: library/fileformats translation-repo9973349
Ref: 2f2e9973349
Node: csv — CSV File Reading and Writing9973800
Ref: library/csv doc9973936
Ref: 2f2f9973936
Ref: library/csv csv-csv-file-reading-and-writing9973936
Ref: 2f309973936
Ref: library/csv module-csv9973936
Ref: 2d9973936
Ref: csv — CSV File Reading and Writing-Footnote-19975847
Ref: csv — CSV File Reading and Writing-Footnote-29975910
Ref: csv — CSV File Reading and Writing-Footnote-39975969
Node: Module Contents<3>9976011
Ref: library/csv csv-contents9976145
Ref: 2f319976145
Ref: library/csv module-contents9976145
Ref: 2f329976145
Ref: library/csv csv reader9976256
Ref: 6af9976256
Ref: library/csv csv writer9977868
Ref: 6b09977868
Ref: library/csv csv register_dialect9979645
Ref: 19219979645
Ref: library/csv csv unregister_dialect9980132
Ref: 1b7b9980132
Ref: library/csv csv get_dialect9980339
Ref: 1b7a9980339
Ref: library/csv csv list_dialects9980570
Ref: 1b7c9980570
Ref: library/csv csv field_size_limit9980657
Ref: 1b799980657
Ref: library/csv csv DictReader9980929
Ref: bda9980929
Ref: library/csv csv DictWriter9982798
Ref: 14069982798
Ref: library/csv csv Dialect9984582
Ref: 180f9984582
Ref: library/csv csv excel9985406
Ref: 2f369985406
Ref: library/csv csv excel_tab9985590
Ref: 2f379985590
Ref: library/csv csv unix_dialect9985796
Ref: 14059985796
Ref: library/csv csv Sniffer9986101
Ref: 2f389986101
Ref: library/csv csv Sniffer sniff9986271
Ref: 2f399986271
Ref: library/csv csv Sniffer has_header9986593
Ref: 1c3f9986593
Ref: library/csv csv-constants9987744
Ref: 2f3a9987744
Ref: library/csv csv QUOTE_ALL9987804
Ref: 2f3b9987804
Ref: library/csv csv QUOTE_MINIMAL9987893
Ref: 2f3c9987893
Ref: library/csv csv QUOTE_NONNUMERIC9988138
Ref: 192f9988138
Ref: library/csv csv QUOTE_NONE9988673
Ref: 2f3d9988673
Ref: library/csv csv QUOTE_NOTNULL9989282
Ref: 6ad9989282
Ref: library/csv csv QUOTE_STRINGS9989720
Ref: 6ae9989720
Ref: library/csv csv Error9990248
Ref: 2f359990248
Ref: Module Contents<3>-Footnote-19990374
Ref: Module Contents<3>-Footnote-29990717
Node: Dialects and Formatting Parameters9991060
Ref: library/csv csv-fmt-params9991217
Ref: 2f349991217
Ref: library/csv dialects-and-formatting-parameters9991217
Ref: 2f3e9991217
Ref: library/csv csv Dialect delimiter9992007
Ref: 2f3f9992007
Ref: library/csv csv Dialect doublequote9992127
Ref: 2f409992127
Ref: library/csv csv Dialect escapechar9992599
Ref: 2f419992599
Ref: library/csv csv Dialect lineterminator9993313
Ref: 2f429993313
Ref: library/csv csv Dialect quotechar9993668
Ref: 2f439993668
Ref: library/csv csv Dialect quoting9994163
Ref: 2f449994163
Ref: library/csv csv Dialect skipinitialspace9994475
Ref: 2f459994475
Ref: library/csv csv Dialect strict9994760
Ref: 2f469994760
Node: Reader Objects9994900
Ref: library/csv id39995053
Ref: 2f479995053
Ref: library/csv reader-objects9995053
Ref: 2f339995053
Ref: library/csv csv csvreader __next__9995246
Ref: 2f489995246
Ref: library/csv csv csvreader dialect9995642
Ref: 2f499995642
Ref: library/csv csv csvreader line_num9995743
Ref: 2f4a9995743
Ref: library/csv csv DictReader fieldnames9995995
Ref: 2f4b9995995
Node: Writer Objects9996200
Ref: library/csv writer-objects9996331
Ref: 2f4c9996331
Ref: library/csv csv csvwriter writerow9996947
Ref: feb9996947
Ref: library/csv csv csvwriter writerows9997285
Ref: 2f4d9997285
Ref: library/csv csv csvwriter dialect9997551
Ref: 2f4e9997551
Ref: library/csv csv DictWriter writeheader9997706
Ref: 14079997706
Node: Examples<11>9998198
Ref: library/csv csv-examples9998306
Ref: 2f4f9998306
Ref: library/csv examples9998306
Ref: 2f509998306
Node: configparser — Configuration file parser10000297
Ref: library/configparser doc10000470
Ref: 2f5110000470
Ref: library/configparser configparser-configuration-file-parser10000470
Ref: 2f5210000470
Ref: library/configparser module-configparser10000470
Ref: 2610000470
Ref: library/configparser translation-repo10000470
Ref: 2f5310000470
Ref: configparser — Configuration file parser-Footnote-110001986
Node: Quick Start10002058
Ref: library/configparser quick-start10002176
Ref: 2f5410002176
Ref: Quick Start-Footnote-110005920
Ref: Quick Start-Footnote-210006122
Node: Supported Datatypes10006324
Ref: library/configparser supported-datatypes10006466
Ref: 2f5810006466
Ref: Supported Datatypes-Footnote-110007788
Ref: Supported Datatypes-Footnote-210007990
Node: Fallback Values10008192
Ref: library/configparser fallback-values10008351
Ref: 2f5c10008351
Node: Supported INI File Structure10009867
Ref: library/configparser supported-ini-file-structure10010023
Ref: 2f5510010023
Ref: Supported INI File Structure-Footnote-110012742
Ref: Supported INI File Structure-Footnote-210012944
Ref: Supported INI File Structure-Footnote-310013146
Ref: Supported INI File Structure-Footnote-410013348
Ref: Supported INI File Structure-Footnote-510013550
Node: Unnamed Sections10013752
Ref: library/configparser id1010013916
Ref: 2f5e10013916
Ref: library/configparser unnamed-sections10013916
Ref: 2f5f10013916
Node: Interpolation of values10014396
Ref: library/configparser interpolation-of-values10014555
Ref: 2f6010014555
Ref: library/configparser configparser BasicInterpolation10014791
Ref: 92d10014791
Ref: library/configparser configparser ExtendedInterpolation10016081
Ref: 92e10016081
Ref: Interpolation of values-Footnote-110017573
Node: Mapping Protocol Access10017775
Ref: library/configparser mapping-protocol-access10017946
Ref: 2f5610017946
Ref: Mapping Protocol Access-Footnote-110020838
Node: Customizing Parser Behaviour10021040
Ref: library/configparser customizing-parser-behaviour10021207
Ref: 2f5710021207
Ref: library/configparser configparser ConfigParser BOOLEAN_STATES10031985
Ref: 2f6310031985
Ref: library/configparser configparser ConfigParser SECTCRE10034171
Ref: 2f5d10034171
Node: Legacy API Examples10035413
Ref: library/configparser legacy-api-examples10035577
Ref: 2f6410035577
Node: ConfigParser Objects10039395
Ref: library/configparser configparser-objects10039554
Ref: 2f6510039554
Ref: library/configparser id1310039554
Ref: 2f6610039554
Ref: library/configparser configparser ConfigParser10039617
Ref: 4df10039617
Ref: library/configparser configparser ConfigParser defaults10045089
Ref: 2f6910045089
Ref: library/configparser configparser ConfigParser sections10045189
Ref: 2f6a10045189
Ref: library/configparser configparser ConfigParser add_section10045332
Ref: 147510045332
Ref: library/configparser configparser ConfigParser has_section10045827
Ref: 2f6b10045827
Ref: library/configparser configparser ConfigParser options10046003
Ref: 2f6c10046003
Ref: library/configparser configparser ConfigParser has_option10046113
Ref: 2f6d10046113
Ref: library/configparser configparser ConfigParser read10046413
Ref: 166f10046413
Ref: library/configparser configparser ConfigParser read_file10048169
Ref: 72b10048169
Ref: library/configparser configparser ConfigParser read_string10048646
Ref: 2f6210048646
Ref: library/configparser configparser ConfigParser read_dict10048995
Ref: 2f6110048995
Ref: library/configparser configparser ConfigParser get10049692
Ref: 147310049692
Ref: library/configparser configparser ConfigParser getint10050653
Ref: 2f5a10050653
Ref: library/configparser configparser ConfigParser getfloat10050942
Ref: 2f5b10050942
Ref: library/configparser configparser ConfigParser getboolean10051246
Ref: 2f5910051246
Ref: library/configparser configparser ConfigParser items10051977
Ref: 2f6e10051977
Ref: library/configparser configparser ConfigParser set10052621
Ref: 147410052621
Ref: library/configparser configparser ConfigParser write10052906
Ref: 1de10052906
Ref: library/configparser configparser ConfigParser remove_option10053815
Ref: 2f7010053815
Ref: library/configparser configparser ConfigParser remove_section10054129
Ref: 2f7110054129
Ref: library/configparser configparser ConfigParser optionxform10054341
Ref: 2f6710054341
Ref: library/configparser configparser UNNAMED_SECTION10055314
Ref: 177210055314
Ref: library/configparser configparser MAX_INTERPOLATION_DEPTH10055485
Ref: 2f7210055485
Node: RawConfigParser Objects10055718
Ref: library/configparser id1510055871
Ref: 2f7310055871
Ref: library/configparser rawconfigparser-objects10055871
Ref: 2f7410055871
Ref: library/configparser configparser RawConfigParser10055940
Ref: 116610055940
Ref: library/configparser configparser RawConfigParser add_section10057354
Ref: 2f7510057354
Ref: library/configparser configparser RawConfigParser set10058089
Ref: 2f7710058089
Node: Exceptions<8>10058917
Ref: library/configparser exceptions10059041
Ref: 2f7810059041
Ref: library/configparser configparser Error10059084
Ref: 2f7910059084
Ref: library/configparser configparser NoSectionError10059186
Ref: 2f6f10059186
Ref: library/configparser configparser DuplicateSectionError10059292
Ref: 147610059292
Ref: library/configparser configparser DuplicateOptionError10059706
Ref: 147710059706
Ref: library/configparser configparser NoOptionError10060066
Ref: 2f7a10060066
Ref: library/configparser configparser InterpolationError10060200
Ref: 2f7b10060200
Ref: library/configparser configparser InterpolationDepthError10060345
Ref: 2f7c10060345
Ref: library/configparser configparser InterpolationMissingOptionError10060605
Ref: 2f7d10060605
Ref: library/configparser configparser InterpolationSyntaxError10060794
Ref: 2f7e10060794
Ref: library/configparser configparser MissingSectionHeaderError10061022
Ref: 2f7f10061022
Ref: library/configparser configparser ParsingError10061167
Ref: 72a10061167
Ref: library/configparser configparser MultilineContinuationError10061474
Ref: 2f6810061474
Ref: library/configparser configparser UnnamedSectionDisabledError10061664
Ref: 2f7610061664
Ref: library/configparser configparser InvalidWriteError10061860
Ref: 1df10061860
Node: tomllib — Parse TOML files10062294
Ref: library/tomllib doc10062462
Ref: 2f8010062462
Ref: library/tomllib module-tomllib10062462
Ref: 10210062462
Ref: library/tomllib tomllib-parse-toml-files10062462
Ref: 2f8110062462
Ref: library/tomllib translation-repo10062462
Ref: 2f8210062462
Ref: library/tomllib tomllib load10063306
Ref: 2f8310063306
Ref: library/tomllib tomllib loads10064031
Ref: 191410064031
Ref: library/tomllib tomllib TOMLDecodeError10064450
Ref: 18f510064450
Ref: library/tomllib tomllib TOMLDecodeError msg10064594
Ref: 2f8510064594
Ref: library/tomllib tomllib TOMLDecodeError doc10064661
Ref: 2f8610064661
Ref: library/tomllib tomllib TOMLDecodeError pos10064729
Ref: 2f8710064729
Ref: library/tomllib tomllib TOMLDecodeError lineno10064806
Ref: 2f8810064806
Ref: library/tomllib tomllib TOMLDecodeError colno10064878
Ref: 2f8910064878
Ref: tomllib — Parse TOML files-Footnote-110065348
Ref: tomllib — Parse TOML files-Footnote-210065412
Ref: tomllib — Parse TOML files-Footnote-310065440
Ref: tomllib — Parse TOML files-Footnote-410065482
Node: Examples<12>10065524
Ref: library/tomllib examples10065626
Ref: 2f8a10065626
Node: Conversion Table10065966
Ref: library/tomllib conversion-table10066068
Ref: 2f8b10066068
Ref: library/tomllib toml-to-py-table10066121
Ref: 2f8410066121
Node: netrc — netrc file processing10067479
Ref: library/netrc doc10067654
Ref: 2f8c10067654
Ref: library/netrc module-netrc10067654
Ref: 9f10067654
Ref: library/netrc netrc-netrc-file-processing10067654
Ref: 2f8d10067654
Ref: library/netrc translation-repo10067654
Ref: 2f8e10067654
Ref: library/netrc netrc netrc10067973
Ref: 1c6110067973
Ref: library/netrc netrc NetrcParseError10069804
Ref: 2f8f10069804
Ref: library/netrc netrc NetrcParseError msg10070030
Ref: 2f9010070030
Ref: library/netrc netrc NetrcParseError filename10070100
Ref: 2f9110070100
Ref: library/netrc netrc NetrcParseError lineno10070170
Ref: 2f9210070170
Ref: netrc — netrc file processing-Footnote-110070319
Node: netrc Objects10070384
Ref: library/netrc id110070465
Ref: 2f9310070465
Ref: library/netrc netrc-objects10070465
Ref: 2f9410070465
Ref: library/netrc netrc netrc authenticators10070570
Ref: 2f9510070570
Ref: library/netrc netrc netrc __repr__10070916
Ref: 2f9610070916
Ref: library/netrc netrc netrc hosts10071140
Ref: 2f9710071140
Ref: library/netrc netrc netrc macros10071338
Ref: 2f9810071338
Node: plistlib — Generate and parse Apple plist files10071421
Ref: library/plistlib doc10071559
Ref: 2f9910071559
Ref: library/plistlib module-plistlib10071559
Ref: b010071559
Ref: library/plistlib plistlib-generate-and-parse-apple-plist-files10071559
Ref: 2f9a10071559
Ref: library/plistlib translation-repo10071559
Ref: 2f9b10071559
Ref: library/plistlib plistlib load10073014
Ref: b4a10073014
Ref: library/plistlib plistlib loads10074268
Ref: b4b10074268
Ref: library/plistlib plistlib dump10074621
Ref: b4c10074621
Ref: library/plistlib plistlib dumps10076030
Ref: b4d10076030
Ref: library/plistlib plistlib UID10076388
Ref: c1810076388
Ref: library/plistlib plistlib UID data10076569
Ref: 2f9c10076569
Ref: library/plistlib plistlib FMT_XML10076755
Ref: 117b10076755
Ref: library/plistlib plistlib FMT_BINARY10076849
Ref: 117c10076849
Ref: library/plistlib plistlib InvalidFileException10076994
Ref: 1ce210076994
Ref: plistlib — Generate and parse Apple plist files-Footnote-110077183
Ref: plistlib — Generate and parse Apple plist files-Footnote-210077251
Node: Examples<13>10077350
Ref: library/plistlib examples10077448
Ref: 2f9d10077448
Node: Cryptographic Services10078303
Ref: library/crypto doc10078452
Ref: 2f9e10078452
Ref: library/crypto crypto10078452
Ref: 2f9f10078452
Ref: library/crypto cryptographic-services10078452
Ref: 2fa010078452
Ref: library/crypto translation-repo10078452
Ref: 2fa110078452
Node: hashlib — Secure hashes and message digests10078868
Ref: library/hashlib doc10079030
Ref: 2fa210079030
Ref: library/hashlib hashlib-secure-hashes-and-message-digests10079030
Ref: 2fa310079030
Ref: library/hashlib module-hashlib10079030
Ref: 6c10079030
Ref: hashlib — Secure hashes and message digests-Footnote-110079942
Ref: hashlib — Secure hashes and message digests-Footnote-210080009
Ref: hashlib — Secure hashes and message digests-Footnote-310080066
Ref: hashlib — Secure hashes and message digests-Footnote-410080116
Ref: hashlib — Secure hashes and message digests-Footnote-510080186
Node: Hash algorithms10080245
Ref: library/hashlib hash-algorithms10080356
Ref: 2fa410080356
Ref: library/hashlib id110080356
Ref: 2fa510080356
Ref: library/hashlib hashlib-usedforsecurity10082489
Ref: 2fae10082489
Ref: Hash algorithms-Footnote-110083189
Ref: Hash algorithms-Footnote-210083297
Node: Usage10083344
Ref: library/hashlib usage10083476
Ref: 2faf10083476
Node: Constructors10084128
Ref: library/hashlib constructors10084255
Ref: 2fb010084255
Ref: library/hashlib hashlib new10084300
Ref: 1d1610084300
Ref: library/hashlib hashlib md510084862
Ref: 180b10084862
Ref: library/hashlib hashlib sha110084923
Ref: 2fa910084923
Ref: library/hashlib hashlib sha22410084985
Ref: 2faa10084985
Ref: library/hashlib hashlib sha25610085049
Ref: 189610085049
Ref: library/hashlib hashlib sha38410085113
Ref: 2fab10085113
Ref: library/hashlib hashlib sha51210085177
Ref: 2fac10085177
Ref: library/hashlib hashlib sha3_22410085241
Ref: ea210085241
Ref: library/hashlib hashlib sha3_25610085307
Ref: ea310085307
Ref: library/hashlib hashlib sha3_38410085373
Ref: ea410085373
Ref: library/hashlib hashlib sha3_51210085439
Ref: ea510085439
Node: Attributes10085603
Ref: library/hashlib attributes10085737
Ref: 2fb110085737
Ref: library/hashlib hashlib algorithms_guaranteed10085838
Ref: 157b10085838
Ref: library/hashlib hashlib algorithms_available10086171
Ref: 157c10086171
Node: Hash Objects10086602
Ref: library/hashlib hash-objects10086753
Ref: 2fb210086753
Ref: library/hashlib hashlib hash digest_size10086906
Ref: 2fb310086906
Ref: library/hashlib hashlib hash block_size10086981
Ref: 2fb410086981
Ref: library/hashlib hashlib hash name10087115
Ref: 114910087115
Ref: library/hashlib hashlib hash update10087541
Ref: 2fa610087541
Ref: library/hashlib hashlib hash digest10087817
Ref: 2fa710087817
Ref: library/hashlib hashlib hash hexdigest10088057
Ref: 2fa810088057
Ref: library/hashlib hashlib hash copy10088328
Ref: 2fb510088328
Node: SHAKE variable length digests10088513
Ref: library/hashlib shake-variable-length-digests10088666
Ref: 2fb610088666
Ref: library/hashlib hashlib shake_12810088745
Ref: ea610088745
Ref: library/hashlib hashlib shake_25610088812
Ref: ea710088812
Ref: library/hashlib hashlib shake digest10089140
Ref: 1e0210089140
Ref: library/hashlib hashlib shake hexdigest10089371
Ref: 1e0310089371
Node: File hashing10089805
Ref: library/hashlib file-hashing10089960
Ref: 2fb710089960
Ref: library/hashlib hashlib file_digest10090105
Ref: 85510090105
Node: Key derivation10091814
Ref: library/hashlib key-derivation10091946
Ref: 2fb810091946
Ref: library/hashlib hashlib pbkdf2_hmac10092257
Ref: 73410092257
Ref: library/hashlib hashlib scrypt10094014
Ref: e3a10094014
Ref: Key derivation-Footnote-110094752
Ref: Key derivation-Footnote-210094814
Ref: Key derivation-Footnote-310094901
Ref: Key derivation-Footnote-410095012
Node: BLAKE210095071
Ref: library/hashlib blake210095182
Ref: 2fb910095182
Ref: library/hashlib hashlib-blake210095182
Ref: 2fba10095182
Ref: BLAKE2-Footnote-110095905
Ref: BLAKE2-Footnote-210095936
Ref: BLAKE2-Footnote-310095995
Node: Creating hash objects10096073
Ref: library/hashlib creating-hash-objects10096158
Ref: 2fbb10096158
Ref: library/hashlib hashlib blake2b10096287
Ref: 85310096287
Ref: library/hashlib hashlib blake2s10096523
Ref: 85410096523
Ref: Creating hash objects-Footnote-110099567
Node: Constants<5>10099618
Ref: library/hashlib constants10099724
Ref: 2fbc10099724
Ref: library/hashlib hashlib blake2b SALT_SIZE10099765
Ref: 2fbd10099765
Ref: library/hashlib hashlib blake2s SALT_SIZE10099794
Ref: 2fbe10099794
Ref: library/hashlib hashlib blake2b PERSON_SIZE10099879
Ref: 2fbf10099879
Ref: library/hashlib hashlib blake2s PERSON_SIZE10099910
Ref: 2fc010099910
Ref: library/hashlib hashlib blake2b MAX_KEY_SIZE10100015
Ref: 2fc110100015
Ref: library/hashlib hashlib blake2s MAX_KEY_SIZE10100047
Ref: 2fc210100047
Ref: library/hashlib hashlib blake2b MAX_DIGEST_SIZE10100098
Ref: 2fc310100098
Ref: library/hashlib hashlib blake2s MAX_DIGEST_SIZE10100133
Ref: 2fc410100133
Node: Examples<14>10100224
Ref: library/hashlib examples10100316
Ref: 2fc510100316
Node: Simple hashing10100492
Ref: library/hashlib simple-hashing10100592
Ref: 2fc610100592
Node: Using different digest sizes10102046
Ref: library/hashlib using-different-digest-sizes10102168
Ref: 2fc710102168
Node: Keyed hashing10103311
Ref: library/hashlib keyed-hashing10103437
Ref: 2fc810103437
Ref: Keyed hashing-Footnote-110105448
Node: Randomized hashing10105491
Ref: library/hashlib randomized-hashing10105604
Ref: 2fc910105604
Ref: Randomized hashing-Footnote-110108213
Ref: Randomized hashing-Footnote-210108265
Node: Personalization10108300
Ref: library/hashlib personalization10108409
Ref: 2fca10108409
Ref: Personalization-Footnote-110110404
Node: Tree mode10110474
Ref: library/hashlib tree-mode10110556
Ref: 2fcb10110556
Node: Credits10111807
Ref: library/hashlib credits10111878
Ref: 2fcc10111878
Ref: library/hashlib hashlib-seealso10113309
Ref: 2fad10113309
Ref: Credits-Footnote-110114299
Ref: Credits-Footnote-210114330
Ref: Credits-Footnote-310114391
Ref: Credits-Footnote-410114469
Ref: Credits-Footnote-510114506
Ref: Credits-Footnote-610114549
Node: hmac — Keyed-Hashing for Message Authentication10114592
Ref: library/hmac doc10114826
Ref: 2fcd10114826
Ref: library/hmac hmac-keyed-hashing-for-message-authentication10114826
Ref: 2fce10114826
Ref: library/hmac module-hmac10114826
Ref: 6e10114826
Ref: library/hmac translation-repo10114826
Ref: 2fcf10114826
Ref: library/hmac hmac new10115293
Ref: c9810115293
Ref: library/hmac hmac digest10116132
Ref: d3410116132
Ref: library/hmac hmac HMAC10116732
Ref: d3510116732
Ref: library/hmac hmac HMAC update10116803
Ref: 114b10116803
Ref: library/hmac hmac HMAC digest10117156
Ref: 2fd010117156
Ref: library/hmac hmac HMAC hexdigest10117772
Ref: 2fd110117772
Ref: library/hmac hmac HMAC copy10118366
Ref: 176910118366
Ref: library/hmac hmac HMAC digest_size10118602
Ref: 114e10118602
Ref: library/hmac hmac HMAC block_size10118689
Ref: 114c10118689
Ref: library/hmac hmac HMAC name10118811
Ref: 114d10118811
Ref: library/hmac hmac compare_digest10119137
Ref: 12d110119137
Ref: hmac — Keyed-Hashing for Message Authentication-Footnote-110120085
Ref: hmac — Keyed-Hashing for Message Authentication-Footnote-210120149
Node: secrets — Generate secure random numbers for managing secrets10120208
Ref: library/secrets doc10120388
Ref: 2fd210120388
Ref: library/secrets module-secrets10120388
Ref: c510120388
Ref: library/secrets secrets-generate-secure-random-numbers-for-managing-secrets10120388
Ref: 2fd310120388
Ref: library/secrets translation-repo10120388
Ref: 2fd410120388
Ref: secrets — Generate secure random numbers for managing secrets-Footnote-110121258
Ref: secrets — Generate secure random numbers for managing secrets-Footnote-210121325
Node: Random numbers10121367
Ref: library/secrets random-numbers10121507
Ref: 2fd510121507
Ref: library/secrets secrets SystemRandom10121680
Ref: 2fd610121680
Ref: library/secrets secrets choice10121898
Ref: 2fd710121898
Ref: library/secrets secrets randbelow10122000
Ref: 2fd810122000
Ref: library/secrets secrets randbits10122126
Ref: 2fd910122126
Node: Generating tokens10122216
Ref: library/secrets generating-tokens10122380
Ref: 2fda10122380
Ref: library/secrets secrets token_bytes10122599
Ref: 2b4210122599
Ref: library/secrets secrets token_hex10122892
Ref: 1b0e10122892
Ref: library/secrets secrets token_urlsafe10123228
Ref: 2fdb10123228
Node: How many bytes should tokens use?10123658
Ref: library/secrets how-many-bytes-should-tokens-use10123745
Ref: 2fdc10123745
Ref: How many bytes should tokens use?-Footnote-110124772
Node: Other functions10124829
Ref: library/secrets other-functions10125005
Ref: 2fdd10125005
Ref: library/secrets secrets compare_digest10125056
Ref: 2fde10125056
Ref: Other functions-Footnote-110125406
Node: Recipes and best practices10125463
Ref: library/secrets recipes-and-best-practices10125613
Ref: 2fdf10125613
Ref: Recipes and best practices-Footnote-110127352
Ref: Recipes and best practices-Footnote-210127408
Node: Generic Operating System Services10127438
Ref: library/allos doc10127607
Ref: 2fe010127607
Ref: library/allos allos10127607
Ref: 2fe110127607
Ref: library/allos generic-operating-system-services10127607
Ref: 2fe210127607
Ref: library/allos translation-repo10127607
Ref: 2fe310127607
Node: os — Miscellaneous operating system interfaces10128527
Ref: library/os doc10128696
Ref: 2fe410128696
Ref: library/os module-os10128696
Ref: a510128696
Ref: library/os os-miscellaneous-operating-system-interfaces10128696
Ref: 2fe510128696
Ref: library/os os error10130983
Ref: 2fe710130983
Ref: library/os os name10131071
Ref: 2fe810131071
Ref: library/os os-filenames10131519
Ref: 2f2a10131519
Ref: os — Miscellaneous operating system interfaces-Footnote-110131946
Node: File Names Command Line Arguments and Environment Variables10132008
Ref: library/os file-names-command-line-arguments-and-environment-variables10132178
Ref: 2fe910132178
Ref: library/os filesystem-encoding10132178
Ref: 2c1b10132178
Node: Python UTF-8 Mode10133517
Ref: library/os python-utf-8-mode10133714
Ref: 2fea10133714
Ref: library/os utf8-mode10133714
Ref: 86710133714
Ref: Python UTF-8 Mode-Footnote-110136571
Ref: Python UTF-8 Mode-Footnote-210136613
Node: Process Parameters10136655
Ref: library/os os-procinfo10136813
Ref: 2feb10136813
Ref: library/os process-parameters10136813
Ref: 2fec10136813
Ref: library/os os ctermid10136967
Ref: 2fed10136967
Ref: library/os os environ10137134
Ref: 25910137134
Ref: library/os os environb10139202
Ref: 25a10139202
Ref: library/os os reload_environ10139809
Ref: 25810139809
Ref: library/os os fsencode10140851
Ref: e5110140851
Ref: library/os os fsdecode10141245
Ref: e5010141245
Ref: library/os os fspath10141643
Ref: e4f10141643
Ref: library/os os PathLike10142056
Ref: e4d10142056
Ref: library/os os PathLike __fspath__10142236
Ref: e4e10142236
Ref: library/os os getenv10142506
Ref: 2fee10142506
Ref: library/os os getenvb10143184
Ref: 141e10143184
Ref: library/os os get_exec_path10143766
Ref: 2ff010143766
Ref: library/os os getegid10144147
Ref: 2ff110144147
Ref: library/os os geteuid10144386
Ref: 1b5a10144386
Ref: library/os os getgid10144520
Ref: 2ff210144520
Ref: library/os os getgrouplist10144746
Ref: 131c10144746
Ref: library/os os getgroups10145141
Ref: 2ff310145141
Ref: library/os os getlogin10146374
Ref: 180a10146374
Ref: library/os os getpgid10146865
Ref: 2ff510146865
Ref: library/os os getpgrp10147100
Ref: 2ff610147100
Ref: library/os os getpid10147228
Ref: 2fe610147228
Ref: library/os os getppid10147397
Ref: 19b410147397
Ref: library/os os getpriority10147782
Ref: 130710147782
Ref: library/os os PRIO_PROCESS10148426
Ref: 2ff710148426
Ref: library/os os PRIO_PGRP10148452
Ref: 2ff810148452
Ref: library/os os PRIO_USER10148475
Ref: 2ff910148475
Ref: library/os os PRIO_DARWIN_THREAD10148675
Ref: 2ffa10148675
Ref: library/os os PRIO_DARWIN_PROCESS10148707
Ref: 2ffb10148707
Ref: library/os os PRIO_DARWIN_BG10148740
Ref: 2ffc10148740
Ref: library/os os PRIO_DARWIN_NONUI10148768
Ref: 2ffd10148768
Ref: library/os os getresuid10148967
Ref: 151d10148967
Ref: library/os os getresgid10149190
Ref: 151c10149190
Ref: library/os os getuid10149414
Ref: 17ff10149414
Ref: library/os os initgroups10149636
Ref: 152010149636
Ref: library/os os putenv10149958
Ref: 25b10149958
Ref: library/os os setegid10151149
Ref: 2fff10151149
Ref: library/os os seteuid10151301
Ref: 300010151301
Ref: library/os os setgid10151452
Ref: 300110151452
Ref: library/os os setgroups10151591
Ref: 2ff410151591
Ref: library/os os setns10152249
Ref: 1b2910152249
Ref: library/os os setpgrp10153775
Ref: 300310153775
Ref: library/os os setpgid10154021
Ref: 300410154021
Ref: library/os os setpriority10154298
Ref: 130810154298
Ref: library/os os setregid10155087
Ref: 300510155087
Ref: library/os os setresgid10155256
Ref: 151e10155256
Ref: library/os os setresuid10155468
Ref: 151f10155468
Ref: library/os os setreuid10155679
Ref: 300610155679
Ref: library/os os getsid10155847
Ref: 300710155847
Ref: library/os os setsid10156018
Ref: 1da210156018
Ref: library/os os setuid10156183
Ref: 300810156183
Ref: library/os os strerror10156322
Ref: 300910156322
Ref: library/os os supports_bytes_environ10156568
Ref: 141d10156568
Ref: library/os os umask10156735
Ref: 300a10156735
Ref: library/os os uname10156940
Ref: 131e10156940
Ref: library/os os unsetenv10158256
Ref: 25c10158256
Ref: library/os os unshare10159089
Ref: 1b2a10159089
Ref: library/os os-unshare-clone-flags10159807
Ref: 300210159807
Ref: library/os os CLONE_FILES10159977
Ref: 300c10159977
Ref: library/os os CLONE_FS10160002
Ref: 300d10160002
Ref: library/os os CLONE_NEWCGROUP10160024
Ref: 300e10160024
Ref: library/os os CLONE_NEWIPC10160053
Ref: 300f10160053
Ref: library/os os CLONE_NEWNET10160079
Ref: 301010160079
Ref: library/os os CLONE_NEWNS10160105
Ref: 301110160105
Ref: library/os os CLONE_NEWPID10160130
Ref: 301210160130
Ref: library/os os CLONE_NEWTIME10160156
Ref: 301310160156
Ref: library/os os CLONE_NEWUSER10160183
Ref: 301410160183
Ref: library/os os CLONE_NEWUTS10160210
Ref: 301510160210
Ref: library/os os CLONE_SIGHAND10160236
Ref: 301610160236
Ref: library/os os CLONE_SYSVSEM10160263
Ref: 301710160263
Ref: library/os os CLONE_THREAD10160290
Ref: 301810160290
Ref: library/os os CLONE_VM10160316
Ref: 301910160316
Ref: Process Parameters-Footnote-110160375
Ref: Process Parameters-Footnote-210160417
Ref: Process Parameters-Footnote-310160459
Ref: Process Parameters-Footnote-410160504
Ref: Process Parameters-Footnote-510160554
Ref: Process Parameters-Footnote-610160601
Node: File Object Creation10160648
Ref: library/os file-object-creation10160815
Ref: 301a10160815
Ref: library/os os-newstreams10160815
Ref: 301b10160815
Ref: library/os os fdopen10160991
Ref: 236710160991
Node: File Descriptor Operations10161318
Ref: library/os file-descriptor-operations10161488
Ref: 301c10161488
Ref: library/os os-fd-ops10161488
Ref: 301d10161488
Ref: library/os os close10162328
Ref: d6d10162328
Ref: library/os os closerange10162771
Ref: 301e10162771
Ref: library/os os copy_file_range10163120
Ref: 189c10163120
Ref: library/os os device_encoding10164798
Ref: 1c1d10164798
Ref: library/os os dup10165215
Ref: 1daa10165215
Ref: library/os os dup210165637
Ref: d5c10165637
Ref: library/os os fchmod10166155
Ref: 52b10166155
Ref: library/os os fchown10166738
Ref: f8c10166738
Ref: library/os os fdatasync10167305
Ref: f8d10167305
Ref: library/os os fpathconf10167536
Ref: 302010167536
Ref: library/os os fstat10168569
Ref: f8e10168569
Ref: library/os os fstatvfs10168833
Ref: f8f10168833
Ref: library/os os fsync10169111
Ref: f9010169111
Ref: library/os os ftruncate10169597
Ref: f9110169597
Ref: library/os os get_blocking10170047
Ref: 103b10170047
Ref: library/os os grantpt10170633
Ref: 19e610170633
Ref: library/os os isatty10171017
Ref: 1c1c10171017
Ref: library/os os lockf10171171
Ref: 131b10171171
Ref: library/os os F_LOCK10171693
Ref: 302210171693
Ref: library/os os F_TLOCK10171713
Ref: 302310171713
Ref: library/os os F_ULOCK10171734
Ref: 302410171734
Ref: library/os os F_TEST10171755
Ref: 302510171755
Ref: library/os os login_tty10171912
Ref: 1ab210171912
Ref: library/os os lseek10172271
Ref: 131f10172271
Ref: library/os os SEEK_SET10173133
Ref: 149510173133
Ref: library/os os SEEK_CUR10173155
Ref: 149610173155
Ref: library/os os SEEK_END10173177
Ref: 149710173177
Ref: library/os os SEEK_HOLE10173756
Ref: 302610173756
Ref: library/os os SEEK_DATA10173779
Ref: 302710173779
Ref: library/os os open10174504
Ref: f9410174504
Ref: library/os os O_RDONLY10176607
Ref: 302810176607
Ref: library/os os O_WRONLY10176629
Ref: 302910176629
Ref: library/os os O_RDWR10176651
Ref: 302b10176651
Ref: library/os os O_APPEND10176671
Ref: 302c10176671
Ref: library/os os O_CREAT10176693
Ref: 302d10176693
Ref: library/os os O_EXCL10176714
Ref: 2cb510176714
Ref: library/os os O_TRUNC10176734
Ref: 302e10176734
Ref: library/os os O_DSYNC10176817
Ref: 302f10176817
Ref: library/os os O_RSYNC10176838
Ref: 303010176838
Ref: library/os os O_SYNC10176859
Ref: 303110176859
Ref: library/os os O_NDELAY10176879
Ref: 303210176879
Ref: library/os os O_NONBLOCK10176901
Ref: 103d10176901
Ref: library/os os O_NOCTTY10176925
Ref: 303310176925
Ref: library/os os O_CLOEXEC10176947
Ref: 127e10176947
Ref: library/os os O_BINARY10177097
Ref: 302a10177097
Ref: library/os os O_NOINHERIT10177119
Ref: 303410177119
Ref: library/os os O_SHORT_LIVED10177144
Ref: 303510177144
Ref: library/os os O_TEMPORARY10177171
Ref: 303610177171
Ref: library/os os O_RANDOM10177196
Ref: 303710177196
Ref: library/os os O_SEQUENTIAL10177218
Ref: 303810177218
Ref: library/os os O_TEXT10177244
Ref: 303910177244
Ref: library/os os O_EVTONLY10177322
Ref: a1d10177322
Ref: library/os os O_FSYNC10177345
Ref: a1e10177345
Ref: library/os os O_SYMLINK10177366
Ref: a1f10177366
Ref: library/os os O_NOFOLLOW_ANY10177389
Ref: a2010177389
Ref: library/os os O_ASYNC10177629
Ref: 303a10177629
Ref: library/os os O_DIRECT10177650
Ref: 303b10177650
Ref: library/os os O_DIRECTORY10177672
Ref: 303c10177672
Ref: library/os os O_NOFOLLOW10177697
Ref: 303d10177697
Ref: library/os os O_NOATIME10177721
Ref: 303e10177721
Ref: library/os os O_PATH10177744
Ref: 117410177744
Ref: library/os os O_TMPFILE10177764
Ref: 117510177764
Ref: library/os os O_SHLOCK10177787
Ref: 163610177787
Ref: library/os os O_EXLOCK10177809
Ref: 163710177809
Ref: library/os os openpty10178107
Ref: 303f10178107
Ref: library/os os pipe10178557
Ref: 1b4c10178557
Ref: library/os os pipe210178903
Ref: 12f110178903
Ref: library/os os posix_fallocate10179295
Ref: f9610179295
Ref: library/os os posix_fadvise10179558
Ref: f9510179558
Ref: library/os os POSIX_FADV_NORMAL10180165
Ref: 304010180165
Ref: library/os os POSIX_FADV_SEQUENTIAL10180196
Ref: 304110180196
Ref: library/os os POSIX_FADV_RANDOM10180231
Ref: 304210180231
Ref: library/os os POSIX_FADV_NOREUSE10180262
Ref: 304310180262
Ref: library/os os POSIX_FADV_WILLNEED10180294
Ref: 304410180294
Ref: library/os os POSIX_FADV_DONTNEED10180327
Ref: 304510180327
Ref: library/os os pread10180564
Ref: d5810180564
Ref: library/os os posix_openpt10180956
Ref: 19e510180956
Ref: library/os os preadv10181554
Ref: d5610181554
Ref: library/os os RWF_NOWAIT10182599
Ref: 304710182599
Ref: library/os os RWF_HIPRI10183103
Ref: 304610183103
Ref: library/os os ptsname10183496
Ref: 19e810183496
Ref: library/os os pwrite10184038
Ref: d5b10184038
Ref: library/os os pwritev10184327
Ref: d5910184327
Ref: library/os os RWF_DSYNC10185371
Ref: 304810185371
Ref: library/os os RWF_SYNC10185650
Ref: 304910185650
Ref: library/os os RWF_APPEND10185927
Ref: 1d1510185927
Ref: library/os os read10186484
Ref: f9710186484
Ref: library/os os readinto10187431
Ref: 25f10187431
Ref: library/os os sendfile10188646
Ref: d0710188646
Ref: library/os os SF_NODISKIO10190159
Ref: 304a10190159
Ref: library/os os SF_MNOWAIT10190184
Ref: 304b10190184
Ref: library/os os SF_SYNC10190208
Ref: 304c10190208
Ref: library/os os SF_NOCACHE10190406
Ref: 304d10190406
Ref: library/os os set_blocking10190690
Ref: 103c10190690
Ref: library/os os splice10191302
Ref: a1c10191302
Ref: library/os os SPLICE_F_MOVE10193601
Ref: 304e10193601
Ref: library/os os SPLICE_F_NONBLOCK10193628
Ref: 304f10193628
Ref: library/os os SPLICE_F_MORE10193659
Ref: 305010193659
Ref: library/os os readv10193716
Ref: d5710193716
Ref: library/os os tcgetpgrp10194337
Ref: 305110194337
Ref: library/os os tcsetpgrp10194565
Ref: 305210194565
Ref: library/os os ttyname10194807
Ref: 305310194807
Ref: library/os os unlockpt10195061
Ref: 19e710195061
Ref: library/os os write10195437
Ref: f9d10195437
Ref: library/os os writev10196291
Ref: d5a10196291
Ref: File Descriptor Operations-Footnote-110196990
Ref: File Descriptor Operations-Footnote-210197032
Ref: File Descriptor Operations-Footnote-310197076
Ref: File Descriptor Operations-Footnote-410197139
Ref: File Descriptor Operations-Footnote-510197181
Ref: File Descriptor Operations-Footnote-610197227
Node: Querying the size of a terminal10197269
Ref: library/os querying-the-size-of-a-terminal10197403
Ref: 305410197403
Ref: library/os terminal-size10197403
Ref: 305510197403
Ref: library/os os get_terminal_size10197509
Ref: 130a10197509
Ref: library/os os terminal_size10198150
Ref: 2ce210198150
Ref: library/os os terminal_size columns10198272
Ref: 305610198272
Ref: library/os os terminal_size lines10198356
Ref: 305710198356
Node: Inheritance of File Descriptors10198439
Ref: library/os fd-inheritance10198573
Ref: 10fe10198573
Ref: library/os inheritance-of-file-descriptors10198573
Ref: 305810198573
Ref: library/os os get_inheritable10199711
Ref: 10ff10199711
Ref: library/os os set_inheritable10199839
Ref: 110010199839
Ref: library/os os get_handle_inheritable10199963
Ref: 110110199963
Ref: library/os os set_handle_inheritable10200130
Ref: 110210200130
Node: Files and Directories10200298
Ref: library/os files-and-directories10200466
Ref: 305910200466
Ref: library/os os-file-dir10200466
Ref: 2fef10200466
Ref: library/os path-fd10200615
Ref: d5510200615
Ref: library/os dir-fd10201558
Ref: 12f210201558
Ref: library/os follow-symlinks10202273
Ref: 12f310202273
Ref: library/os os access10202855
Ref: 12f410202855
Ref: library/os os F_OK10205427
Ref: 305a10205427
Ref: library/os os R_OK10205445
Ref: 305b10205445
Ref: library/os os W_OK10205463
Ref: 305c10205463
Ref: library/os os X_OK10205481
Ref: 305d10205481
Ref: library/os os chdir10205671
Ref: 82210205671
Ref: library/os os chflags10206359
Ref: 12f510206359
Ref: library/os os chmod10207458
Ref: 52a10207458
Ref: library/os os chown10209551
Ref: 12f610209551
Ref: library/os os chroot10210576
Ref: 1d6410210576
Ref: library/os os fchdir10210810
Ref: f8b10210810
Ref: library/os os getcwd10211215
Ref: 18f110211215
Ref: library/os os getcwdb10211309
Ref: c8410211309
Ref: library/os os lchflags10211627
Ref: 305f10211627
Ref: library/os os lchmod10212123
Ref: 52910212123
Ref: library/os os lchown10212967
Ref: 306010212967
Ref: library/os os link10213485
Ref: 12f710213485
Ref: library/os os listdir10214359
Ref: 130210214359
Ref: library/os os listdrives10215859
Ref: 6c610215859
Ref: library/os os listmounts10216492
Ref: 6c810216492
Ref: library/os os listvolumes10217333
Ref: 6c710217333
Ref: library/os os lstat10218053
Ref: 6c910218053
Ref: library/os os mkdir10219188
Ref: 52c10219188
Ref: library/os mkdir-modebits10219490
Ref: 306110219490
Ref: library/os os makedirs10220672
Ref: 52d10220672
Ref: library/os os mkfifo10222420
Ref: f9210222420
Ref: library/os os mknod10223335
Ref: f9310223335
Ref: library/os os major10224238
Ref: 194610224238
Ref: library/os os minor10224409
Ref: 194710224409
Ref: library/os os makedev10224580
Ref: 194810224580
Ref: library/os os pathconf10224704
Ref: 130310224704
Ref: library/os os pathconf_names10225807
Ref: 306310225807
Ref: library/os os readlink10226131
Ref: b1c10226131
Ref: library/os os remove10227631
Ref: 12f810227631
Ref: library/os os removedirs10228576
Ref: 306410228576
Ref: library/os os rename10229425
Ref: 12f910229425
Ref: library/os os renames10231105
Ref: 306510231105
Ref: library/os os replace10231899
Ref: 12fa10231899
Ref: library/os os rmdir10232786
Ref: 12fb10232786
Ref: library/os os scandir10233442
Ref: c5610233442
Ref: library/os os scandir close10235220
Ref: eba10235220
Ref: library/os os DirEntry10236767
Ref: 6c410236767
Ref: library/os os DirEntry name10237953
Ref: 306710237953
Ref: library/os os DirEntry path10238324
Ref: 19e010238324
Ref: library/os os DirEntry inode10239059
Ref: 1a3510239059
Ref: library/os os DirEntry is_dir10239418
Ref: 306610239418
Ref: library/os os DirEntry is_file10240853
Ref: f8610240853
Ref: library/os os DirEntry is_symlink10241576
Ref: 306810241576
Ref: library/os os DirEntry is_junction10242427
Ref: 6c510242427
Ref: library/os os DirEntry stat10242862
Ref: 1a5310242862
Ref: library/os os stat10244624
Ref: 26d10244624
Ref: library/os os stat_result10247236
Ref: 16c810247236
Ref: library/os os stat_result st_mode10247487
Ref: c0110247487
Ref: library/os os stat_result st_ino10247582
Ref: 306910247582
Ref: library/os os stat_result st_dev10247831
Ref: 306a10247831
Ref: library/os os stat_result st_nlink10247923
Ref: 306b10247923
Ref: library/os os stat_result st_uid10247986
Ref: 306c10247986
Ref: library/os os stat_result st_gid10248060
Ref: 306d10248060
Ref: library/os os stat_result st_size10248135
Ref: 306e10248135
Ref: library/os os stat_result st_atime10248389
Ref: 306f10248389
Ref: library/os os stat_result st_mtime10248479
Ref: 2efa10248479
Ref: library/os os stat_result st_ctime10248583
Ref: 307010248583
Ref: library/os os stat_result st_atime_ns10248959
Ref: 307110248959
Ref: library/os os stat_result st_mtime_ns10249113
Ref: 307210249113
Ref: library/os os stat_result st_ctime_ns10249281
Ref: 307310249281
Ref: library/os os stat_result st_birthtime10249726
Ref: 307410249726
Ref: library/os os stat_result st_birthtime_ns10250006
Ref: 307510250006
Ref: library/os os stat_result st_blocks10251592
Ref: 307610251592
Ref: library/os os stat_result st_blksize10251766
Ref: 307710251766
Ref: library/os os stat_result st_rdev10251966
Ref: 17a710251966
Ref: library/os os stat_result st_flags10252041
Ref: 307810252041
Ref: library/os os stat_result st_gen10252266
Ref: 307910252266
Ref: library/os os stat_result st_fstype10252416
Ref: d5d10252416
Ref: library/os os stat_result st_rsize10252623
Ref: 307a10252623
Ref: library/os os stat_result st_creator10252687
Ref: 307b10252687
Ref: library/os os stat_result st_type10252751
Ref: 307c10252751
Ref: library/os os stat_result st_file_attributes10252873
Ref: 103a10252873
Ref: library/os os stat_result st_reparse_tag10253253
Ref: c0210253253
Ref: library/os os statvfs10255655
Ref: 130410255655
Ref: library/os os supports_dir_fd10257725
Ref: 12ff10257725
Ref: library/os os supports_effective_ids10258886
Ref: 130610258886
Ref: library/os os supports_fd10259629
Ref: 130510259629
Ref: library/os os supports_follow_symlinks10260453
Ref: 130010260453
Ref: library/os os symlink10261589
Ref: 12fc10261589
Ref: library/os os sync10263533
Ref: 131a10263533
Ref: library/os os truncate10263667
Ref: 103e10263667
Ref: library/os os unlink10264201
Ref: 12fd10264201
Ref: library/os os utime10264748
Ref: 12fe10264748
Ref: library/os os walk10266642
Ref: 6d110266642
Ref: library/os os fwalk10271941
Ref: d5410271941
Ref: library/os os memfd_create10274594
Ref: c0010274594
Ref: library/os os MFD_CLOEXEC10275454
Ref: 307d10275454
Ref: library/os os MFD_ALLOW_SEALING10275479
Ref: 307e10275479
Ref: library/os os MFD_HUGETLB10275510
Ref: 307f10275510
Ref: library/os os MFD_HUGE_SHIFT10275535
Ref: 308010275535
Ref: library/os os MFD_HUGE_MASK10275563
Ref: 308110275563
Ref: library/os os MFD_HUGE_64KB10275590
Ref: 308210275590
Ref: library/os os MFD_HUGE_512KB10275617
Ref: 308310275617
Ref: library/os os MFD_HUGE_1MB10275645
Ref: 308410275645
Ref: library/os os MFD_HUGE_2MB10275671
Ref: 308510275671
Ref: library/os os MFD_HUGE_8MB10275697
Ref: 308610275697
Ref: library/os os MFD_HUGE_16MB10275723
Ref: 308710275723
Ref: library/os os MFD_HUGE_32MB10275750
Ref: 308810275750
Ref: library/os os MFD_HUGE_256MB10275777
Ref: 308910275777
Ref: library/os os MFD_HUGE_512MB10275805
Ref: 308a10275805
Ref: library/os os MFD_HUGE_1GB10275833
Ref: 308b10275833
Ref: library/os os MFD_HUGE_2GB10275859
Ref: 308c10275859
Ref: library/os os MFD_HUGE_16GB10275885
Ref: 308d10275885
Ref: library/os os eventfd10276138
Ref: a1b10276138
Ref: library/os os eventfd_read10278152
Ref: 308f10278152
Ref: library/os os eventfd_write10278441
Ref: 309010278441
Ref: library/os os EFD_CLOEXEC10278742
Ref: 1b4010278742
Ref: library/os os EFD_NONBLOCK10278927
Ref: 1b4110278927
Ref: library/os os EFD_SEMAPHORE10279130
Ref: 1b4210279130
Ref: Files and Directories-Footnote-110279498
Ref: Files and Directories-Footnote-210279544
Ref: Files and Directories-Footnote-310279586
Ref: Files and Directories-Footnote-410279651
Ref: Files and Directories-Footnote-510279731
Ref: Files and Directories-Footnote-610279813
Ref: Files and Directories-Footnote-710279902
Ref: Files and Directories-Footnote-810279991
Ref: Files and Directories-Footnote-910280049
Node: Timer File Descriptors10280096
Ref: library/os os-timerfd10280210
Ref: 47e10280210
Ref: library/os timer-file-descriptors10280210
Ref: 309110280210
Ref: library/os os timerfd_create10280424
Ref: 52010280424
Ref: library/os os timerfd_settime10283116
Ref: 52110283116
Ref: library/os os timerfd_settime_ns10285832
Ref: 52210285832
Ref: library/os os timerfd_gettime10286185
Ref: 52310286185
Ref: library/os os timerfd_gettime_ns10286781
Ref: 52410286781
Ref: library/os os TFD_NONBLOCK10287006
Ref: 52510287006
Ref: library/os os TFD_CLOEXEC10287368
Ref: 52610287368
Ref: library/os os TFD_TIMER_ABSTIME10287653
Ref: 52710287653
Ref: library/os os TFD_TIMER_CANCEL_ON_SET10288040
Ref: 52810288040
Ref: Timer File Descriptors-Footnote-110288451
Ref: Timer File Descriptors-Footnote-210288505
Ref: Timer File Descriptors-Footnote-310288559
Ref: Timer File Descriptors-Footnote-410288614
Ref: Timer File Descriptors-Footnote-510288666
Ref: Timer File Descriptors-Footnote-610288719
Ref: Timer File Descriptors-Footnote-710288763
Node: Linux extended attributes10288818
Ref: library/os linux-extended-attributes10288932
Ref: 309310288932
Ref: library/os os getxattr10289078
Ref: 130c10289078
Ref: library/os os listxattr10289744
Ref: 130d10289744
Ref: library/os os removexattr10290359
Ref: 130e10290359
Ref: library/os os setxattr10291056
Ref: 130f10291056
Ref: library/os os XATTR_SIZE_MAX10292307
Ref: 309610292307
Ref: library/os os XATTR_CREATE10292443
Ref: 309510292443
Ref: library/os os XATTR_REPLACE10292615
Ref: 309410292615
Node: Process Management10292798
Ref: library/os os-process10292966
Ref: 309710292966
Ref: library/os process-management10292966
Ref: 309810292966
Ref: library/os os abort10293581
Ref: 309a10293581
Ref: library/os os add_dll_directory10293957
Ref: bdf10293957
Ref: library/os os execl10295121
Ref: 309910295121
Ref: library/os os execle10295168
Ref: 309b10295168
Ref: library/os os execlp10295221
Ref: 309c10295221
Ref: library/os os execlpe10295269
Ref: 309d10295269
Ref: library/os os execv10295323
Ref: 2ffe10295323
Ref: library/os os execve10295359
Ref: 130110295359
Ref: library/os os execvp10295401
Ref: 309e10295401
Ref: library/os os execvpe10295438
Ref: 309f10295438
Ref: library/os os _exit10298816
Ref: 26dc10298816
Ref: library/os os EX_OK10299561
Ref: 30a010299561
Ref: library/os os EX_USAGE10299795
Ref: 30a110299795
Ref: library/os os EX_DATAERR10299987
Ref: 30a210299987
Ref: library/os os EX_NOINPUT10300118
Ref: 30a310300118
Ref: library/os os EX_NOUSER10300273
Ref: 30a410300273
Ref: library/os os EX_NOHOST10300405
Ref: 30a510300405
Ref: library/os os EX_UNAVAILABLE10300537
Ref: 30a610300537
Ref: library/os os EX_SOFTWARE10300682
Ref: 30a710300682
Ref: library/os os EX_OSERR10300825
Ref: 30a810300825
Ref: library/os os EX_OSFILE10301017
Ref: 30a910301017
Ref: library/os os EX_CANTCREAT10301208
Ref: 30aa10301208
Ref: library/os os EX_IOERR10301367
Ref: 30ab10301367
Ref: library/os os EX_TEMPFAIL10301524
Ref: 30ac10301524
Ref: library/os os EX_PROTOCOL10301808
Ref: 30ad10301808
Ref: library/os os EX_NOPERM10301981
Ref: 30ae10301981
Ref: library/os os EX_CONFIG10302197
Ref: 30af10302197
Ref: library/os os EX_NOTFOUND10302350
Ref: 30b010302350
Ref: library/os os fork10302495
Ref: 4b610302495
Ref: library/os os forkpty10304521
Ref: 4b710304521
Ref: library/os os kill10305688
Ref: 156f10305688
Ref: library/os os killpg10306568
Ref: 1da310306568
Ref: library/os os nice10306826
Ref: 130910306826
Ref: library/os os pidfd_open10306999
Ref: 6a510306999
Ref: library/os os PIDFD_NONBLOCK10307410
Ref: 6c310307410
Ref: library/os os plock10307861
Ref: 30b110307861
Ref: library/os os popen10308086
Ref: 31a10308086
Ref: library/os os posix_spawn10310222
Ref: 52f10310222
Ref: library/os os POSIX_SPAWN_OPEN10311324
Ref: 30b210311324
Ref: library/os os POSIX_SPAWN_CLOSE10311497
Ref: 30b310311497
Ref: library/os os POSIX_SPAWN_DUP210311620
Ref: 30b410311620
Ref: library/os os POSIX_SPAWN_CLOSEFROM10311758
Ref: 53010311758
Ref: library/os os posix_spawnp10314669
Ref: 1df910314669
Ref: library/os os register_at_fork10315428
Ref: 35510315428
Ref: library/os os spawnl10316877
Ref: 31b10316877
Ref: library/os os spawnle10316919
Ref: 30b510316919
Ref: library/os os spawnlp10316967
Ref: 30b610316967
Ref: library/os os spawnlpe10317010
Ref: 30b710317010
Ref: library/os os spawnv10317059
Ref: 30b810317059
Ref: library/os os spawnve10317102
Ref: 30b910317102
Ref: library/os os spawnvp10317151
Ref: 30ba10317151
Ref: library/os os spawnvpe10317195
Ref: 30bb10317195
Ref: library/os os P_NOWAIT10321298
Ref: 30bc10321298
Ref: library/os os P_NOWAITO10321320
Ref: 30be10321320
Ref: library/os os P_WAIT10321669
Ref: 30bd10321669
Ref: library/os os P_DETACH10322089
Ref: 30bf10322089
Ref: library/os os P_OVERLAY10322111
Ref: 30c010322111
Ref: library/os os startfile10322601
Ref: 1c6b10322601
Ref: library/os os system10325195
Ref: 166410325195
Ref: library/os os times10326951
Ref: 131d10326951
Ref: library/os os wait10327964
Ref: f9a10327964
Ref: library/os os waitid10328878
Ref: f9b10328878
Ref: library/os os waitpid10330320
Ref: f9c10330320
Ref: library/os os wait310332690
Ref: f9810332690
Ref: library/os os wait410333318
Ref: f9910333318
Ref: library/os os P_PID10333909
Ref: 30c110333909
Ref: library/os os P_PGID10333928
Ref: 30c210333928
Ref: library/os os P_ALL10333948
Ref: 30c310333948
Ref: library/os os P_PIDFD10333967
Ref: b1810333967
Ref: library/os os WCONTINUED10334700
Ref: 30c610334700
Ref: library/os os WEXITED10335049
Ref: 30c410335049
Ref: library/os os WSTOPPED10335416
Ref: 30c510335416
Ref: library/os os WUNTRACED10335756
Ref: 30cb10335756
Ref: library/os os WNOHANG10336162
Ref: 30c710336162
Ref: library/os os WNOWAIT10336459
Ref: 30c810336459
Ref: library/os os CLD_EXITED10336823
Ref: 30ca10336823
Ref: library/os os CLD_KILLED10336847
Ref: b1610336847
Ref: library/os os CLD_DUMPED10336871
Ref: 30cc10336871
Ref: library/os os CLD_TRAPPED10336895
Ref: 30cd10336895
Ref: library/os os CLD_STOPPED10336920
Ref: b1710336920
Ref: library/os os CLD_CONTINUED10336945
Ref: 30ce10336945
Ref: library/os os waitstatus_to_exitcode10337283
Ref: b1910337283
Ref: library/os os WCOREDUMP10338793
Ref: 30d510338793
Ref: library/os os WIFCONTINUED10339097
Ref: 30d610339097
Ref: library/os os WIFSTOPPED10339447
Ref: 30d310339447
Ref: library/os os WIFSIGNALED10339874
Ref: 30d110339874
Ref: library/os os WIFEXITED10340086
Ref: 30cf10340086
Ref: library/os os WEXITSTATUS10340387
Ref: 30d010340387
Ref: library/os os WSTOPSIG10340621
Ref: 30d410340621
Ref: library/os os WTERMSIG10340873
Ref: 30d210340873
Ref: Process Management-Footnote-110341185
Ref: Process Management-Footnote-210341257
Ref: Process Management-Footnote-310341300
Ref: Process Management-Footnote-410341350
Ref: Process Management-Footnote-510341396
Ref: Process Management-Footnote-610341441
Ref: Process Management-Footnote-710341493
Ref: Process Management-Footnote-810341602
Ref: Process Management-Footnote-910341644
Node: Interface to the scheduler10341690
Ref: library/os interface-to-the-scheduler10341869
Ref: 30d810341869
Ref: library/os os-scheduling-policy10342256
Ref: 30d910342256
Ref: library/os os SCHED_OTHER10342256
Ref: 30da10342256
Ref: library/os os SCHED_BATCH10342319
Ref: 30db10342319
Ref: library/os os SCHED_DEADLINE10342468
Ref: 25d10342468
Ref: library/os os SCHED_IDLE10342587
Ref: 30dc10342587
Ref: library/os os SCHED_NORMAL10342681
Ref: 25e10342681
Ref: library/os os SCHED_SPORADIC10342778
Ref: 30dd10342778
Ref: library/os os SCHED_FIFO10342861
Ref: 30de10342861
Ref: library/os os SCHED_RR10342932
Ref: 30df10342932
Ref: library/os os SCHED_RESET_ON_FORK10342994
Ref: 30e010342994
Ref: library/os os sched_param10343216
Ref: 18f810343216
Ref: library/os os sched_param sched_priority10343512
Ref: 30e110343512
Ref: library/os os sched_get_priority_min10343608
Ref: 131110343608
Ref: library/os os sched_get_priority_max10343773
Ref: 131010343773
Ref: library/os os sched_setscheduler10343938
Ref: 131810343938
Ref: library/os os sched_getscheduler10344227
Ref: 131410344227
Ref: library/os os sched_setparam10344452
Ref: 131710344452
Ref: library/os os sched_getparam10344669
Ref: 131310344669
Ref: library/os os sched_rr_get_interval10344872
Ref: 131510344872
Ref: library/os os sched_yield10345047
Ref: 131910345047
Ref: library/os os sched_setaffinity10345164
Ref: 131610345164
Ref: library/os os sched_getaffinity10345430
Ref: 131210345430
Ref: Interface to the scheduler-Footnote-110345758
Node: Miscellaneous System Information10345809
Ref: library/os miscellaneous-system-information10345987
Ref: 30e210345987
Ref: library/os os-path10345987
Ref: 30e310345987
Ref: library/os os confstr10346074
Ref: 18d410346074
Ref: library/os os confstr_names10347113
Ref: 30e410347113
Ref: library/os os cpu_count10347406
Ref: 4dc10347406
Ref: library/os os getloadavg10347905
Ref: 190d10347905
Ref: library/os os process_cpu_count10348159
Ref: 4db10348159
Ref: library/os os sysconf10348772
Ref: 18d510348772
Ref: library/os os sysconf_names10349196
Ref: 30e510349196
Ref: library/os os curdir10349757
Ref: 2c3d10349757
Ref: library/os os pardir10349958
Ref: 306210349958
Ref: library/os os sep10350159
Ref: 87b10350159
Ref: library/os os altsep10350571
Ref: 87c10350571
Ref: library/os os extsep10350870
Ref: 30e610350870
Ref: library/os os pathsep10351057
Ref: 211d10351057
Ref: library/os os defpath10351301
Ref: 1dcc10351301
Ref: library/os os linesep10351509
Ref: 25b810351509
Ref: library/os os devnull10351922
Ref: 1dfc10351922
Ref: library/os os RTLD_LAZY10352096
Ref: 132010352096
Ref: library/os os RTLD_NOW10352119
Ref: 132110352119
Ref: library/os os RTLD_GLOBAL10352141
Ref: 132210352141
Ref: library/os os RTLD_LOCAL10352166
Ref: 132310352166
Ref: library/os os RTLD_NODELETE10352190
Ref: 132410352190
Ref: library/os os RTLD_NOLOAD10352217
Ref: 132510352217
Ref: library/os os RTLD_DEEPBIND10352242
Ref: 132610352242
Ref: Miscellaneous System Information-Footnote-110352528
Node: Random numbers<2>10352574
Ref: library/os random-numbers10352717
Ref: 30e710352717
Ref: library/os os getrandom10352768
Ref: ebb10352768
Ref: library/os os urandom10353598
Ref: 74710353598
Ref: library/os os GRND_NONBLOCK10355687
Ref: 30e910355687
Ref: library/os os GRND_RANDOM10356162
Ref: 30e810356162
Ref: Random numbers<2>-Footnote-110356383
Ref: Random numbers<2>-Footnote-210356446
Node: io — Core tools for working with streams10356488
Ref: library/io doc10356702
Ref: 30ea10356702
Ref: library/io io-core-tools-for-working-with-streams10356702
Ref: 30eb10356702
Ref: library/io module-io10356702
Ref: 8310356702
Ref: library/io translation-repo10356702
Ref: 30ec10356702
Ref: io — Core tools for working with streams-Footnote-110357096
Node: Overview<2>10357158
Ref: library/io io-overview10357270
Ref: 25b610357270
Ref: library/io overview10357270
Ref: 30ed10357270
Node: Text I/O10358536
Ref: library/io text-i-o10358611
Ref: 30ee10358611
Node: Binary I/O10359514
Ref: library/io binary-i-o10359605
Ref: 30ef10359605
Node: Raw I/O10360476
Ref: library/io raw-i-o10360550
Ref: 30f010360550
Node: Text Encoding10361004
Ref: library/io io-text-encoding10361152
Ref: 9c210361152
Ref: library/io text-encoding10361152
Ref: 30f110361152
Ref: Text Encoding-Footnote-110362329
Node: Opt-in EncodingWarning10362371
Ref: library/io io-encoding-warning10362443
Ref: 212910362443
Ref: library/io opt-in-encodingwarning10362443
Ref: 30f210362443
Ref: Opt-in EncodingWarning-Footnote-110363261
Node: High-level Module Interface10363303
Ref: library/io high-level-module-interface10363455
Ref: 30f310363455
Ref: library/io io DEFAULT_BUFFER_SIZE10363530
Ref: 1a2510363530
Ref: library/io io open10363765
Ref: 74110363765
Ref: library/io io open_code10364186
Ref: 1a8010364186
Ref: library/io io text_encoding10364849
Ref: 1a2410364849
Ref: library/io io BlockingIOError10365986
Ref: 30f410365986
Ref: library/io io UnsupportedOperation10366117
Ref: 1d6710366117
Node: Class hierarchy10366468
Ref: library/io class-hierarchy10366620
Ref: 30f510366620
Node: I/O Base Classes10371323
Ref: library/io i-o-base-classes10371412
Ref: 30f610371412
Ref: library/io io IOBase10371465
Ref: 50610371465
Ref: library/io io IOBase close10373313
Ref: 50710373313
Ref: library/io io IOBase closed10373723
Ref: 1df610373723
Ref: library/io io IOBase fileno10373798
Ref: 179510373798
Ref: library/io io IOBase flush10374019
Ref: 2ccc10374019
Ref: library/io io IOBase isatty10374179
Ref: 205310374179
Ref: library/io io IOBase readable10374319
Ref: 15b510374319
Ref: library/io io IOBase readline10374481
Ref: 153110374481
Ref: library/io io IOBase readlines10374853
Ref: 278410374853
Ref: library/io io IOBase seek10375417
Ref: 149410375417
Ref: library/io io IOBase seekable10376397
Ref: 15b710376397
Ref: library/io io IOBase tell10376630
Ref: 15b410376630
Ref: library/io io IOBase truncate10376703
Ref: 151810376703
Ref: library/io io IOBase writable10377286
Ref: 15b610377286
Ref: library/io io IOBase writelines10377487
Ref: 176110377487
Ref: library/io io IOBase __del__10377710
Ref: 30f710377710
Ref: library/io io RawIOBase10377927
Ref: 12d810377927
Ref: library/io io RawIOBase read10378434
Ref: 101f10378434
Ref: library/io io RawIOBase readall10379119
Ref: 30f810379119
Ref: library/io io RawIOBase readinto10379275
Ref: 102010379275
Ref: library/io io RawIOBase write10379616
Ref: 15b310379616
Ref: library/io io BufferedIOBase10380255
Ref: 8a410380255
Ref: library/io io BufferedIOBase raw10381470
Ref: 15b810381470
Ref: library/io io BufferedIOBase detach10381741
Ref: 2dd110381741
Ref: library/io io BufferedIOBase read10382177
Ref: 153010382177
Ref: library/io io BufferedIOBase read110383461
Ref: 2e3c10383461
Ref: library/io io BufferedIOBase readinto10384049
Ref: 187d10384049
Ref: library/io io BufferedIOBase readinto110384583
Ref: 101e10384583
Ref: library/io io BufferedIOBase write10385082
Ref: ed910385082
Ref: I/O Base Classes-Footnote-110385938
Ref: I/O Base Classes-Footnote-210385980
Node: Raw File I/O10386022
Ref: library/io raw-file-i-o10386136
Ref: 30f910386136
Ref: library/io io FileIO10386183
Ref: 151710386183
Ref: library/io io FileIO mode10388515
Ref: 30fa10388515
Ref: library/io io FileIO name10388590
Ref: 2dd510388590
Node: Buffered Streams10388735
Ref: library/io buffered-streams10388844
Ref: 30fb10388844
Ref: library/io io BytesIO10388990
Ref: 10a610388990
Ref: library/io io BytesIO getbuffer10389478
Ref: 13f910389478
Ref: library/io io BytesIO getvalue10390048
Ref: 2e3a10390048
Ref: library/io io BytesIO read110390170
Ref: 30fc10390170
Ref: library/io io BytesIO readinto110390379
Ref: 30fd10390379
Ref: library/io io BufferedReader10390536
Ref: 141610390536
Ref: library/io io BufferedReader peek10391377
Ref: 30fe10391377
Ref: library/io io BufferedReader read10391677
Ref: 30ff10391677
Ref: library/io io BufferedReader read110391823
Ref: 310010391823
Ref: library/io io BufferedWriter10392058
Ref: 15b910392058
Ref: library/io io BufferedWriter flush10393179
Ref: 310110393179
Ref: library/io io BufferedWriter write10393363
Ref: 310210393363
Ref: library/io io BufferedRandom10393720
Ref: 15ba10393720
Ref: library/io io BufferedRWPair10394423
Ref: 15bb10394423
Node: Text I/O<2>10395369
Ref: library/io id110395457
Ref: 310310395457
Ref: library/io io TextIOBase10395496
Ref: 8a510395496
Ref: library/io io TextIOBase encoding10395813
Ref: 310410395813
Ref: library/io io TextIOBase errors10395973
Ref: 151610395973
Ref: library/io io TextIOBase newlines10396057
Ref: 310510396057
Ref: library/io io TextIOBase buffer10396301
Ref: 14ab10396301
Ref: library/io io TextIOBase detach10396600
Ref: 176810396600
Ref: library/io io TextIOBase read10397118
Ref: 205610397118
Ref: library/io io TextIOBase readline10397326
Ref: 209010397326
Ref: library/io io TextIOBase seek10397596
Ref: 310610397596
Ref: library/io io TextIOBase tell10398567
Ref: 310710398567
Ref: library/io io TextIOBase write10398771
Ref: 204510398771
Ref: library/io io TextIOWrapper10398903
Ref: 9c010398903
Ref: library/io io TextIOWrapper line_buffering10402959
Ref: 310810402959
Ref: library/io io TextIOWrapper write_through10403041
Ref: 310910403041
Ref: library/io io TextIOWrapper reconfigure10403201
Ref: d4210403201
Ref: library/io io TextIOWrapper seek10404096
Ref: 310a10404096
Ref: library/io io TextIOWrapper tell10405021
Ref: 179910405021
Ref: library/io io StringIO10405244
Ref: 112b10405244
Ref: library/io io StringIO getvalue10406411
Ref: 310b10406411
Ref: library/io io IncrementalNewlineDecoder10407066
Ref: 1a2610407066
Node: Static Typing10407254
Ref: library/io static-typing10407393
Ref: 310c10407393
Ref: library/io io Reader10407636
Ref: 23610407636
Ref: library/io io Reader read10407883
Ref: 310d10407883
Ref: library/io io Writer10408272
Ref: 23710408272
Ref: library/io io Writer write10408524
Ref: 310e10408524
Node: Performance<3>10408934
Ref: library/io performance10409049
Ref: 311010409049
Node: Binary I/O<2>10409298
Ref: library/io id210409382
Ref: 311110409382
Node: Text I/O<3>10410034
Ref: library/io id310410145
Ref: 311210410145
Node: Multi-threading<3>10410710
Ref: library/io multi-threading10410818
Ref: 311310410818
Ref: Multi-threading<3>-Footnote-110411392
Node: Reentrancy10411436
Ref: library/io reentrancy10411524
Ref: 311410411524
Node: time — Time access and conversions10412318
Ref: library/time doc10412523
Ref: 311510412523
Ref: library/time module-time10412523
Ref: f410412523
Ref: library/time time-time-access-and-conversions10412523
Ref: 311610412523
Ref: library/time translation-repo10412523
Ref: 311710412523
Ref: library/time epoch10413225
Ref: 2ef910413225
Ref: time — Time access and conversions-Footnote-110417708
Ref: time — Time access and conversions-Footnote-210417758
Ref: time — Time access and conversions-Footnote-310417823
Node: Functions<4>10417881
Ref: library/time functions10417993
Ref: 311a10417993
Ref: library/time time-functions10417993
Ref: 311b10417993
Ref: library/time time asctime10418032
Ref: 13ef10418032
Ref: library/time time pthread_getcpuclockid10418703
Ref: d8d10418703
Ref: library/time time clock_getres10419325
Ref: 136510419325
Ref: library/time time clock_gettime10419602
Ref: 136610419602
Ref: library/time time clock_gettime_ns10419984
Ref: cdd10419984
Ref: library/time time clock_settime10420187
Ref: 136710420187
Ref: library/time time clock_settime_ns10420581
Ref: cde10420581
Ref: library/time time ctime10420809
Ref: 28a910420809
Ref: library/time time get_clock_info10421389
Ref: 136410421389
Ref: library/time time gmtime10422526
Ref: 13c810422526
Ref: library/time time localtime10423018
Ref: 170010423018
Ref: library/time time mktime10423663
Ref: 13f010423663
Ref: library/time time monotonic10424373
Ref: 55c10424373
Ref: library/time time monotonic_ns10425473
Ref: cdf10425473
Ref: library/time time perf_counter10425617
Ref: c7c10425617
Ref: library/time time perf_counter_ns10426576
Ref: ce010426576
Ref: library/time time process_time10426731
Ref: c7d10426731
Ref: library/time time process_time_ns10427260
Ref: ce110427260
Ref: library/time time sleep10427415
Ref: 8ad10427415
Ref: library/time time strftime10429531
Ref: 13f110429531
Ref: library/time leap-second10436985
Ref: 311d10436985
Ref: library/time time strptime10438189
Ref: 163410438189
Ref: library/time time struct_time10439892
Ref: ee810439892
Ref: library/time time struct_time tm_year10440537
Ref: 16ff10440537
Ref: library/time time struct_time tm_mon10440801
Ref: 311e10440801
Ref: library/time time struct_time tm_mday10441061
Ref: 311f10441061
Ref: library/time time struct_time tm_hour10441320
Ref: 312010441320
Ref: library/time time struct_time tm_min10441578
Ref: 312110441578
Ref: library/time time struct_time tm_sec10441837
Ref: 312210441837
Ref: library/time time struct_time tm_wday10442313
Ref: 312310442313
Ref: library/time time struct_time tm_yday10442584
Ref: 312410442584
Ref: library/time time struct_time tm_isdst10442845
Ref: 28ba10442845
Ref: library/time time struct_time tm_zone10443111
Ref: 311910443111
Ref: library/time time struct_time tm_gmtoff10443388
Ref: 311810443388
Ref: library/time time time10444065
Ref: 55d10444065
Ref: library/time time time_ns10445643
Ref: ce210445643
Ref: library/time time thread_time10445832
Ref: b3210445832
Ref: library/time time thread_time_ns10446501
Ref: d8c10446501
Ref: library/time time tzset10446654
Ref: 312510446654
Ref: Functions<4>-Footnote-110450565
Ref: Functions<4>-Footnote-210450626
Ref: Functions<4>-Footnote-310450725
Ref: Functions<4>-Footnote-410450767
Ref: Functions<4>-Footnote-510451548
Ref: Functions<4>-Footnote-610452329
Ref: Functions<4>-Footnote-710452379
Ref: Functions<4>-Footnote-810452438
Ref: Functions<4>-Footnote-910453219
Ref: Functions<4>-Footnote-1010453267
Ref: Functions<4>-Footnote-1110453318
Ref: Functions<4>-Footnote-1210453367
Node: Clock ID Constants10453414
Ref: library/time clock-id-constants10453553
Ref: 312610453553
Ref: library/time time-clock-id-constants10453553
Ref: 309210453553
Ref: library/time time CLOCK_BOOTTIME10453715
Ref: d8910453715
Ref: library/time time CLOCK_HIGHRES10454193
Ref: 312710454193
Ref: library/time time CLOCK_MONOTONIC10454521
Ref: 8a910454521
Ref: library/time time CLOCK_MONOTONIC_RAW10454725
Ref: 312810454725
Ref: library/time time CLOCK_MONOTONIC_RAW_APPROX10454994
Ref: 312910454994
Ref: library/time time CLOCK_PROCESS_CPUTIME_ID10455256
Ref: 312a10455256
Ref: library/time time CLOCK_PROF10455418
Ref: d8a10455418
Ref: library/time time CLOCK_TAI10455591
Ref: 1d3f10455591
Ref: library/time time CLOCK_THREAD_CPUTIME_ID10455886
Ref: 312b10455886
Ref: library/time time CLOCK_UPTIME10456031
Ref: d8b10456031
Ref: library/time time CLOCK_UPTIME_RAW10456314
Ref: c3910456314
Ref: library/time time CLOCK_UPTIME_RAW_APPROX10456613
Ref: 312c10456613
Ref: library/time time CLOCK_REALTIME10456962
Ref: 8aa10456962
Ref: Clock ID Constants-Footnote-110457219
Node: Timezone Constants10457346
Ref: library/time time-timezone-constants10457464
Ref: 312d10457464
Ref: library/time timezone-constants10457464
Ref: 312e10457464
Ref: library/time time altzone10457521
Ref: 312f10457521
Ref: library/time time daylight10457809
Ref: 313010457809
Ref: library/time time timezone10457895
Ref: 313110457895
Ref: library/time time tzname10458093
Ref: 313210458093
Node: logging — Logging facility for Python10459299
Ref: library/logging doc10459502
Ref: 313310459502
Ref: library/logging logging-logging-facility-for-python10459502
Ref: 313410459502
Ref: library/logging module-logging10459502
Ref: 8b10459502
Ref: library/logging translation-repo10459502
Ref: 313510459502
Ref: logging — Logging facility for Python-Footnote-110462994
Node: Logger Objects10463071
Ref: library/logging logger10463184
Ref: 313610463184
Ref: library/logging logger-objects10463184
Ref: 313710463184
Ref: library/logging logging Logger10464338
Ref: d4810464338
Ref: library/logging logging Logger name10464366
Ref: 313810464366
Ref: library/logging logging Logger level10464593
Ref: 313910464593
Ref: library/logging logging Logger parent10464886
Ref: 313a10464886
Ref: library/logging logging Logger propagate10465147
Ref: 169c10465147
Ref: library/logging logging Logger handlers10467216
Ref: 313b10467216
Ref: library/logging logging Logger disabled10467593
Ref: 313e10467593
Ref: library/logging logging Logger setLevel10467865
Ref: 169a10467865
Ref: library/logging logging Logger isEnabledFor10469849
Ref: 14fe10469849
Ref: library/logging logging Logger getEffectiveLevel10470192
Ref: 314010470192
Ref: library/logging logging Logger getChild10470700
Ref: 14fc10470700
Ref: library/logging logging Logger getChildren10471201
Ref: 1b3a10471201
Ref: library/logging logging Logger debug10471771
Ref: 102d10471771
Ref: library/logging logging Logger info10477268
Ref: 314210477268
Ref: library/logging logging Logger warning10477453
Ref: 1a5c10477453
Ref: library/logging logging Logger error10477865
Ref: 314410477865
Ref: library/logging logging Logger critical10478052
Ref: 102c10478052
Ref: library/logging logging Logger log10478256
Ref: 102a10478256
Ref: library/logging logging Logger exception10478452
Ref: 102b10478452
Ref: library/logging logging Logger addFilter10478773
Ref: 314510478773
Ref: library/logging logging Logger removeFilter10478872
Ref: 314610478872
Ref: library/logging logging Logger filter10478979
Ref: 314710478979
Ref: library/logging logging Logger addHandler10479416
Ref: 313c10479416
Ref: library/logging logging Logger removeHandler10479513
Ref: 313d10479513
Ref: library/logging logging Logger findCaller10479618
Ref: 314810479618
Ref: library/logging logging Logger handle10480420
Ref: 314910480420
Ref: library/logging logging Logger makeRecord10480819
Ref: 314a10480819
Ref: library/logging logging Logger hasHandlers10481082
Ref: 314b10481082
Node: Logging Levels10481713
Ref: library/logging levels10481850
Ref: 86b10481850
Ref: library/logging logging-levels10481850
Ref: 314c10481850
Ref: library/logging logging NOTSET10482523
Ref: 313f10482523
Ref: library/logging logging DEBUG10483133
Ref: 20c710483133
Ref: library/logging logging INFO10483468
Ref: 20c810483468
Ref: library/logging logging WARNING10483715
Ref: 20c910483715
Ref: library/logging logging ERROR10484224
Ref: 20ca10484224
Ref: library/logging logging CRITICAL10484540
Ref: 20cb10484540
Node: Handler Objects10484812
Ref: library/logging handler10484952
Ref: 314d10484952
Ref: library/logging handler-objects10484952
Ref: 314e10484952
Ref: library/logging logging Handler10485272
Ref: 169d10485272
Ref: library/logging logging Handler __init__10485301
Ref: 314f10485301
Ref: library/logging logging Handler createLock10485596
Ref: 315010485596
Ref: library/logging logging Handler acquire10485784
Ref: 315110485784
Ref: library/logging logging Handler release10485898
Ref: 315210485898
Ref: library/logging logging Handler setLevel10486000
Ref: 315310486000
Ref: library/logging logging Handler setFormatter10486589
Ref: 315410486589
Ref: library/logging logging Handler addFilter10486770
Ref: 315510486770
Ref: library/logging logging Handler removeFilter10486870
Ref: 315610486870
Ref: library/logging logging Handler filter10486978
Ref: 315710486978
Ref: library/logging logging Handler flush10487377
Ref: 315810487377
Ref: library/logging logging Handler close10487545
Ref: 315910487545
Ref: library/logging logging Handler handle10487889
Ref: 315a10487889
Ref: library/logging logging Handler handleError10488167
Ref: 315b10488167
Ref: library/logging logging Handler format10488969
Ref: 315d10488969
Ref: library/logging logging Handler emit10489137
Ref: 315c10489137
Node: Formatter Objects10490675
Ref: library/logging formatter-objects10490815
Ref: 315e10490815
Ref: library/logging id110490815
Ref: 315f10490815
Ref: library/logging logging Formatter10490870
Ref: 169e10490870
Ref: library/logging logging Formatter format10493063
Ref: 316210493063
Ref: library/logging logging Formatter formatTime10494540
Ref: 316010494540
Ref: library/logging logging Formatter formatException10496945
Ref: 316310496945
Ref: library/logging logging Formatter formatStack10497283
Ref: 316410497283
Ref: library/logging logging BufferingFormatter10497576
Ref: 316510497576
Ref: library/logging logging BufferingFormatter formatHeader10497995
Ref: 316610497995
Ref: library/logging logging BufferingFormatter formatFooter10498309
Ref: 316710498309
Ref: library/logging logging BufferingFormatter format10498614
Ref: 316810498614
Node: Filter Objects10498945
Ref: library/logging filter10499087
Ref: 316910499087
Ref: library/logging filter-objects10499087
Ref: 316a10499087
Ref: library/logging logging Filter10499601
Ref: 140310499601
Ref: library/logging logging Filter filter10499893
Ref: 316b10499893
Node: LogRecord Objects10502309
Ref: library/logging log-record10502454
Ref: 316e10502454
Ref: library/logging logrecord-objects10502454
Ref: 316f10502454
Ref: library/logging logging LogRecord10502748
Ref: 11e810502748
Ref: library/logging logging LogRecord getMessage10505309
Ref: 317210505309
Node: LogRecord attributes10506815
Ref: library/logging id210506967
Ref: 317510506967
Ref: library/logging logrecord-attributes10506967
Ref: 314110506967
Node: LoggerAdapter Objects10515838
Ref: library/logging logger-adapter10515986
Ref: 317610515986
Ref: library/logging loggeradapter-objects10515986
Ref: 317710515986
Ref: library/logging logging LoggerAdapter10516267
Ref: 14fd10516267
Ref: library/logging logging LoggerAdapter process10516857
Ref: 317910516857
Ref: library/logging logging LoggerAdapter manager10517312
Ref: 317a10517312
Ref: library/logging logging LoggerAdapter _log10517407
Ref: 317b10517407
Node: Thread Safety10518666
Ref: library/logging thread-safety10518816
Ref: 317c10518816
Node: Module-Level Functions10519475
Ref: library/logging module-level-functions10519627
Ref: 317d10519627
Ref: library/logging logging getLogger10519785
Ref: b5b10519785
Ref: library/logging logging getLoggerClass10520516
Ref: 317e10520516
Ref: library/logging logging getLogRecordFactory10520994
Ref: 317310520994
Ref: library/logging logging debug10521457
Ref: 314310521457
Ref: library/logging logging info10522350
Ref: 316c10522350
Ref: library/logging logging warning10522559
Ref: 35410522559
Ref: library/logging logging error10522982
Ref: 318010522982
Ref: library/logging logging critical10523193
Ref: 318110523193
Ref: library/logging logging exception10523410
Ref: 169b10523410
Ref: library/logging logging log10523742
Ref: 318210523742
Ref: library/logging logging disable10523948
Ref: 318310523948
Ref: library/logging logging addLevelName10525169
Ref: 318410525169
Ref: library/logging logging getLevelNamesMapping10525827
Ref: 86a10525827
Ref: library/logging logging getLevelName10526154
Ref: 318610526154
Ref: library/logging logging getHandlerByName10527799
Ref: 1b4a10527799
Ref: library/logging logging getHandlerNames10527984
Ref: 1a5610527984
Ref: library/logging logging makeLogRecord10528114
Ref: 317010528114
Ref: library/logging logging basicConfig10528482
Ref: bf510528482
Ref: library/logging logging shutdown10533918
Ref: 318710533918
Ref: library/logging logging setLoggerClass10534360
Ref: 317f10534360
Ref: library/logging logging setLogRecordFactory10534976
Ref: 317410534976
Ref: Module-Level Functions-Footnote-110536313
Node: Module-Level Attributes10536378
Ref: library/logging module-level-attributes10536553
Ref: 318810536553
Ref: library/logging logging lastResort10536622
Ref: 140210536622
Ref: library/logging logging raiseExceptions10537225
Ref: 140110537225
Node: Integration with the warnings module10537622
Ref: library/logging integration-with-the-warnings-module10537766
Ref: 318910537766
Ref: library/logging logging captureWarnings10537988
Ref: 318a10537988
Ref: Integration with the warnings module-Footnote-110539383
Ref: Integration with the warnings module-Footnote-210539425
Node: logging config — Logging configuration10539478
Ref: library/logging config doc10539682
Ref: 318b10539682
Ref: library/logging config logging-config-logging-configuration10539682
Ref: 318c10539682
Ref: library/logging config module-logging config10539682
Ref: 8c10539682
Ref: library/logging config translation-repo10539682
Ref: 318d10539682
Ref: logging config — Logging configuration-Footnote-110540333
Node: Configuration functions10540407
Ref: library/logging config configuration-functions10540539
Ref: 318e10540539
Ref: library/logging config logging-config-api10540539
Ref: 14f910540539
Ref: library/logging config logging config dictConfig10540981
Ref: 13b810540981
Ref: library/logging config logging config fileConfig10543098
Ref: d4a10543098
Ref: library/logging config logging config listen10545831
Ref: 116710545831
Ref: library/logging config logging-eval-security10547484
Ref: 319210547484
Ref: library/logging config logging config stopListening10549177
Ref: 319110549177
Node: Security considerations10549423
Ref: library/logging config security-considerations10549595
Ref: 319310549595
Node: Configuration dictionary schema10550313
Ref: library/logging config configuration-dictionary-schema10550487
Ref: 319510550487
Ref: library/logging config logging-config-dictschema10550487
Ref: 318f10550487
Node: Dictionary Schema Details10551504
Ref: library/logging config dictionary-schema-details10551631
Ref: 319710551631
Ref: library/logging config logging-config-dictschema-formatters10552438
Ref: 319810552438
Node: Incremental Configuration10557320
Ref: library/logging config incremental-configuration10557474
Ref: 319a10557474
Ref: library/logging config logging-config-dict-incremental10557474
Ref: 319910557474
Node: Object connections10558919
Ref: library/logging config logging-config-dict-connections10559068
Ref: 319610559068
Ref: library/logging config object-connections10559068
Ref: 319b10559068
Node: User-defined objects10561463
Ref: library/logging config logging-config-dict-userdef10561614
Ref: 319410561614
Ref: library/logging config user-defined-objects10561614
Ref: 319c10561614
Node: Handler configuration order10566224
Ref: library/logging config handler-config-dict-order10566383
Ref: 319d10566383
Ref: library/logging config handler-configuration-order10566383
Ref: 319e10566383
Node: Access to external objects10567696
Ref: library/logging config access-to-external-objects10567861
Ref: 319f10567861
Ref: library/logging config logging-config-dict-externalobj10567861
Ref: 31a010567861
Node: Access to internal objects10569160
Ref: library/logging config access-to-internal-objects10569336
Ref: 31a110569336
Ref: library/logging config logging-config-dict-internalobj10569336
Ref: 31a210569336
Node: Import resolution and custom importers10572774
Ref: library/logging config import-resolution-and-custom-importers10572966
Ref: 31a410572966
Ref: library/logging config logging-import-resolution10572966
Ref: 31a510572966
Node: Configuring QueueHandler and QueueListener10573946
Ref: library/logging config configure-queue10574103
Ref: 192e10574103
Ref: library/logging config configuring-queuehandler-and-queuelistener10574103
Ref: 31a610574103
Node: Configuration file format10577310
Ref: library/logging config configuration-file-format10577452
Ref: 31ab10577452
Ref: library/logging config logging-config-fileformat10577452
Ref: 319010577452
Node: logging handlers — Logging handlers10584823
Ref: library/logging handlers doc10585051
Ref: 31ac10585051
Ref: library/logging handlers logging-handlers-logging-handlers10585051
Ref: 31ad10585051
Ref: library/logging handlers module-logging handlers10585051
Ref: 8d10585051
Ref: library/logging handlers translation-repo10585051
Ref: 31ae10585051
Ref: logging handlers — Logging handlers-Footnote-110586120
Node: StreamHandler10586197
Ref: library/logging handlers stream-handler10586304
Ref: 31af10586304
Ref: library/logging handlers streamhandler10586304
Ref: 31b010586304
Ref: library/logging handlers logging StreamHandler10586618
Ref: 140010586618
Ref: library/logging handlers logging StreamHandler emit10586857
Ref: 31b110586857
Ref: library/logging handlers logging StreamHandler flush10587207
Ref: 31b310587207
Ref: library/logging handlers logging StreamHandler setStream10587500
Ref: d4910587500
Ref: library/logging handlers logging StreamHandler terminator10587915
Ref: 31b210587915
Node: FileHandler10588331
Ref: library/logging handlers file-handler10588458
Ref: 31b410588458
Ref: library/logging handlers filehandler10588458
Ref: 31b510588458
Ref: library/logging handlers logging FileHandler10588693
Ref: 1c3b10588693
Ref: library/logging handlers logging FileHandler close10589526
Ref: 31b710589526
Ref: library/logging handlers logging FileHandler emit10589581
Ref: 31b610589581
Ref: FileHandler-Footnote-110589869
Node: NullHandler10589934
Ref: library/logging handlers null-handler10590066
Ref: 31b810590066
Ref: library/logging handlers nullhandler10590066
Ref: 31b910590066
Ref: library/logging handlers logging NullHandler10590327
Ref: 148c10590327
Ref: library/logging handlers logging NullHandler emit10590428
Ref: 31ba10590428
Ref: library/logging handlers logging NullHandler handle10590497
Ref: 31bb10590497
Ref: library/logging handlers logging NullHandler createLock10590568
Ref: 31bc10590568
Node: WatchedFileHandler10590851
Ref: library/logging handlers watched-file-handler10590991
Ref: 31be10590991
Ref: library/logging handlers watchedfilehandler10590991
Ref: 31bf10590991
Ref: library/logging handlers logging handlers WatchedFileHandler10592006
Ref: 31c010592006
Ref: library/logging handlers logging handlers WatchedFileHandler reopenIfNeeded10592849
Ref: eb610592849
Ref: library/logging handlers logging handlers WatchedFileHandler emit10593142
Ref: 31c110593142
Node: BaseRotatingHandler10593310
Ref: library/logging handlers base-rotating-handler10593458
Ref: 31c210593458
Ref: library/logging handlers baserotatinghandler10593458
Ref: 31c310593458
Ref: library/logging handlers logging handlers BaseRotatingHandler10593846
Ref: 31c410593846
Ref: library/logging handlers logging handlers BaseRotatingHandler namer10594036
Ref: 31c510594036
Ref: library/logging handlers logging handlers BaseRotatingHandler rotator10595775
Ref: 31c810595775
Ref: library/logging handlers logging handlers BaseRotatingHandler rotation_filename10596060
Ref: 31c610596060
Ref: library/logging handlers logging handlers BaseRotatingHandler rotate10596620
Ref: 31c910596620
Node: RotatingFileHandler10597932
Ref: library/logging handlers rotating-file-handler10598086
Ref: 31cb10598086
Ref: library/logging handlers rotatingfilehandler10598086
Ref: 31cc10598086
Ref: library/logging handlers logging handlers RotatingFileHandler10598278
Ref: 192910598278
Ref: library/logging handlers logging handlers RotatingFileHandler doRollover10600260
Ref: 31ce10600260
Ref: library/logging handlers logging handlers RotatingFileHandler emit10600340
Ref: 31cd10600340
Ref: library/logging handlers logging handlers RotatingFileHandler shouldRollover10600472
Ref: 31cf10600472
Node: TimedRotatingFileHandler10600620
Ref: library/logging handlers timed-rotating-file-handler10600768
Ref: 31d010600768
Ref: library/logging handlers timedrotatingfilehandler10600768
Ref: 31d110600768
Ref: library/logging handlers logging handlers TimedRotatingFileHandler10601002
Ref: 116310601002
Ref: library/logging handlers logging handlers TimedRotatingFileHandler doRollover10606165
Ref: 31d310606165
Ref: library/logging handlers logging handlers TimedRotatingFileHandler emit10606245
Ref: 31d210606245
Ref: library/logging handlers logging handlers TimedRotatingFileHandler getFilesToDelete10606372
Ref: 31c710606372
Ref: library/logging handlers logging handlers TimedRotatingFileHandler shouldRollover10606599
Ref: 31d410606599
Node: SocketHandler10606763
Ref: library/logging handlers socket-handler10606907
Ref: 31d510606907
Ref: library/logging handlers sockethandler10606907
Ref: 31d610606907
Ref: library/logging handlers logging handlers SocketHandler10607120
Ref: 116410607120
Ref: library/logging handlers logging handlers SocketHandler close10607534
Ref: 31d710607534
Ref: library/logging handlers logging handlers SocketHandler emit10607591
Ref: 31d810607591
Ref: library/logging handlers logging handlers SocketHandler handleError10608027
Ref: 31d910608027
Ref: library/logging handlers logging handlers SocketHandler makeSocket10608257
Ref: 31da10608257
Ref: library/logging handlers logging handlers SocketHandler makePickle10608501
Ref: 31db10608501
Ref: library/logging handlers logging handlers SocketHandler send10609311
Ref: 31dc10609311
Ref: library/logging handlers logging handlers SocketHandler createSocket10609632
Ref: 86e10609632
Node: DatagramHandler10610832
Ref: library/logging handlers datagram-handler10610965
Ref: 31dd10610965
Ref: library/logging handlers datagramhandler10610965
Ref: 31de10610965
Ref: library/logging handlers logging handlers DatagramHandler10611203
Ref: 116510611203
Ref: library/logging handlers logging handlers DatagramHandler emit10612124
Ref: 31df10612124
Ref: library/logging handlers logging handlers DatagramHandler makeSocket10612479
Ref: 31e010612479
Ref: library/logging handlers logging handlers DatagramHandler send10612667
Ref: 31e110612667
Node: SysLogHandler10612882
Ref: library/logging handlers syslog-handler10613019
Ref: 31e210613019
Ref: library/logging handlers sysloghandler10613019
Ref: 31e310613019
Ref: library/logging handlers logging handlers SysLogHandler10613225
Ref: 86d10613225
Ref: library/logging handlers logging handlers SysLogHandler close10615540
Ref: 31e410615540
Ref: library/logging handlers logging handlers SysLogHandler createSocket10615616
Ref: 86c10615616
Ref: library/logging handlers logging handlers SysLogHandler emit10616071
Ref: 31e510616071
Ref: library/logging handlers logging handlers SysLogHandler encodePriority10617959
Ref: 31e610617959
Ref: library/logging handlers logging handlers SysLogHandler mapPriority10621983
Ref: 31e710621983
Ref: SysLogHandler-Footnote-110622473
Ref: SysLogHandler-Footnote-210622528
Ref: SysLogHandler-Footnote-310622593
Ref: SysLogHandler-Footnote-410622652
Node: NTEventLogHandler10622717
Ref: library/logging handlers nt-eventlog-handler10622850
Ref: 31e810622850
Ref: library/logging handlers nteventloghandler10622850
Ref: 31e910622850
Ref: library/logging handlers logging handlers NTEventLogHandler10623185
Ref: 31ea10623185
Ref: library/logging handlers logging handlers NTEventLogHandler close10624247
Ref: 31eb10624247
Ref: library/logging handlers logging handlers NTEventLogHandler emit10624649
Ref: 31ec10624649
Ref: library/logging handlers logging handlers NTEventLogHandler getEventCategory10624807
Ref: 31ed10624807
Ref: library/logging handlers logging handlers NTEventLogHandler getEventType10625009
Ref: 31ee10625009
Ref: library/logging handlers logging handlers NTEventLogHandler getMessageID10625596
Ref: 31ef10625596
Node: SMTPHandler10626026
Ref: library/logging handlers smtp-handler10626159
Ref: 31f010626159
Ref: library/logging handlers smtphandler10626159
Ref: 31f110626159
Ref: library/logging handlers logging handlers SMTPHandler10626356
Ref: 189a10626356
Ref: library/logging handlers logging handlers SMTPHandler emit10627617
Ref: 31f210627617
Ref: library/logging handlers logging handlers SMTPHandler getSubject10627721
Ref: 31f310627721
Node: MemoryHandler10627867
Ref: library/logging handlers memory-handler10627994
Ref: 31f410627994
Ref: library/logging handlers memoryhandler10627994
Ref: 31f510627994
Ref: library/logging handlers logging handlers BufferingHandler10628697
Ref: 31f610628697
Ref: library/logging handlers logging handlers BufferingHandler emit10628894
Ref: 31f710628894
Ref: library/logging handlers logging handlers BufferingHandler flush10629084
Ref: 31f910629084
Ref: library/logging handlers logging handlers BufferingHandler shouldFlush10629321
Ref: 31f810629321
Ref: library/logging handlers logging handlers MemoryHandler10629504
Ref: 31a310629504
Ref: library/logging handlers logging handlers MemoryHandler close10630330
Ref: 31fb10630330
Ref: library/logging handlers logging handlers MemoryHandler flush10630458
Ref: 31fc10630458
Ref: library/logging handlers logging handlers MemoryHandler setTarget10630765
Ref: 31fa10630765
Ref: library/logging handlers logging handlers MemoryHandler shouldFlush10630855
Ref: 31fd10630855
Node: HTTPHandler10630981
Ref: library/logging handlers http-handler10631109
Ref: 31fe10631109
Ref: library/logging handlers httphandler10631109
Ref: 31ff10631109
Ref: library/logging handlers logging handlers HTTPHandler10631341
Ref: 102e10631341
Ref: library/logging handlers logging handlers HTTPHandler mapLogRecord10632308
Ref: 320010632308
Ref: library/logging handlers logging handlers HTTPHandler emit10632765
Ref: 320110632765
Node: QueueHandler10633501
Ref: library/logging handlers queue-handler10633629
Ref: 320210633629
Ref: library/logging handlers queuehandler10633629
Ref: 320310633629
Ref: library/logging handlers logging handlers QueueHandler10634370
Ref: 1b4910634370
Ref: library/logging handlers logging handlers QueueHandler emit10635518
Ref: 320610635518
Ref: library/logging handlers logging handlers QueueHandler prepare10636021
Ref: 320710636021
Ref: library/logging handlers logging handlers QueueHandler enqueue10637960
Ref: 320410637960
Ref: library/logging handlers logging handlers QueueHandler listener10638206
Ref: 31a710638206
Node: QueueListener10638501
Ref: library/logging handlers queue-listener10638609
Ref: 320810638609
Ref: library/logging handlers queuelistener10638609
Ref: 320910638609
Ref: library/logging handlers logging handlers QueueListener10639631
Ref: 24210639631
Ref: library/logging handlers logging handlers QueueListener dequeue10641185
Ref: 320a10641185
Ref: library/logging handlers logging handlers QueueListener prepare10641466
Ref: 320b10641466
Ref: library/logging handlers logging handlers QueueListener handle10641783
Ref: 320c10641783
Ref: library/logging handlers logging handlers QueueListener start10642045
Ref: 24310642045
Ref: library/logging handlers logging handlers QueueListener stop10642338
Ref: 320d10642338
Ref: library/logging handlers logging handlers QueueListener enqueue_sentinel10642649
Ref: 320e10642649
Node: platform — Access to underlying platform’s identifying data10643152
Ref: library/platform doc10643379
Ref: 320f10643379
Ref: library/platform module-platform10643379
Ref: af10643379
Ref: library/platform platform-access-to-underlying-platform-s-identifying-data10643379
Ref: 321010643379
Ref: library/platform translation-repo10643379
Ref: 321110643379
Ref: platform — Access to underlying platform’s identifying data-Footnote-110643974
Node: Cross platform10644042
Ref: library/platform cross-platform10644178
Ref: 321210644178
Ref: library/platform platform architecture10644227
Ref: 19ee10644227
Ref: library/platform platform machine10645554
Ref: 321310645554
Ref: library/platform platform node10645804
Ref: 321410645804
Ref: library/platform platform platform10645979
Ref: 1aae10645979
Ref: library/platform platform processor10646927
Ref: 321610646927
Ref: library/platform platform python_build10647248
Ref: 321710647248
Ref: library/platform platform python_compiler10647395
Ref: 321810647395
Ref: library/platform platform python_branch10647518
Ref: 321910647518
Ref: library/platform platform python_implementation10647632
Ref: 321a10647632
Ref: library/platform platform python_revision10647836
Ref: 321b10647836
Ref: library/platform platform python_version10647959
Ref: 321c10647959
Ref: library/platform platform python_version_tuple10648208
Ref: 321d10648208
Ref: library/platform platform release10648488
Ref: 321e10648488
Ref: library/platform platform system10648665
Ref: 225010648665
Ref: library/platform platform system_alias10649094
Ref: 321510649094
Ref: library/platform platform version10649377
Ref: 321f10649377
Ref: library/platform platform uname10649696
Ref: 1dfb10649696
Ref: library/platform platform invalidate_caches10650462
Ref: 27d10650462
Node: Java platform10650782
Ref: library/platform java-platform10650943
Ref: 322010650943
Ref: library/platform platform java_ver10650990
Ref: 32c10650990
Node: Windows platform10651627
Ref: library/platform windows-platform10651788
Ref: 322110651788
Ref: library/platform platform win32_ver10651841
Ref: 1d3210651841
Ref: library/platform platform win32_edition10652669
Ref: 322210652669
Ref: library/platform platform win32_is_iot10652999
Ref: 322310652999
Node: macOS platform10653193
Ref: library/platform macos-platform10653353
Ref: 322410653353
Ref: library/platform platform mac_ver10653402
Ref: 1dfd10653402
Node: iOS platform10653783
Ref: library/platform ios-platform10653941
Ref: 322510653941
Ref: library/platform platform ios_ver10653986
Ref: 224f10653986
Node: Unix platforms10654761
Ref: library/platform unix-platforms10654920
Ref: 322610654920
Ref: library/platform platform libc_ver10654969
Ref: 17dd10654969
Node: Linux platforms10655586
Ref: library/platform linux-platforms10655749
Ref: 322710655749
Ref: library/platform platform freedesktop_os_release10655800
Ref: a2910655800
Ref: Linux platforms-Footnote-110657266
Node: Android platform10657339
Ref: library/platform android-platform10657509
Ref: 322810657509
Ref: library/platform platform android_ver10657562
Ref: 19ae10657562
Ref: Android platform-Footnote-110658700
Ref: Android platform-Footnote-210658779
Ref: Android platform-Footnote-310658850
Ref: Android platform-Footnote-410658922
Node: Command-line usage<3>10658996
Ref: library/platform command-line-usage10659142
Ref: 322910659142
Ref: library/platform platform-cli10659142
Ref: 322a10659142
Ref: library/platform cmdoption-platform-terse10659413
Ref: 322b10659413
Ref: library/platform cmdoption-platform-nonaliased10659603
Ref: 322c10659603
Node: errno — Standard errno system symbols10659997
Ref: library/errno doc10660235
Ref: 322d10660235
Ref: library/errno errno-standard-errno-system-symbols10660235
Ref: 322e10660235
Ref: library/errno module-errno10660235
Ref: 5b10660235
Ref: library/errno translation-repo10660235
Ref: 322f10660235
Ref: library/errno errno errorcode10660638
Ref: 323010660638
Ref: library/errno errno EPERM10661159
Ref: 1b3e10661159
Ref: library/errno errno ENOENT10661285
Ref: 26ec10661285
Ref: library/errno errno ESRCH10661416
Ref: 26f010661416
Ref: library/errno errno EINTR10661538
Ref: f8910661538
Ref: library/errno errno EIO10661665
Ref: 323110661665
Ref: library/errno errno ENXIO10661702
Ref: 323210661702
Ref: library/errno errno E2BIG10661757
Ref: 323310661757
Ref: library/errno errno ENOEXEC10661804
Ref: 323410661804
Ref: library/errno errno EBADF10661853
Ref: b5610661853
Ref: library/errno errno ECHILD10661898
Ref: 26e510661898
Ref: library/errno errno EAGAIN10662023
Ref: 26e010662023
Ref: library/errno errno ENOMEM10662136
Ref: 323510662136
Ref: library/errno errno EACCES10662180
Ref: 26ef10662180
Ref: library/errno errno EFAULT10662301
Ref: 323610662301
Ref: library/errno errno ENOTBLK10662343
Ref: 323710662343
Ref: library/errno errno EBUSY10662396
Ref: 323810662396
Ref: library/errno errno EEXIST10662449
Ref: 26eb10662449
Ref: library/errno errno EXDEV10662565
Ref: 301f10662565
Ref: library/errno errno ENODEV10662612
Ref: 323910662612
Ref: library/errno errno ENOTDIR10662657
Ref: 26ee10662657
Ref: library/errno errno EISDIR10662781
Ref: 26ed10662781
Ref: library/errno errno EINVAL10662902
Ref: 1dba10662902
Ref: library/errno errno ENFILE10662949
Ref: 323a10662949
Ref: library/errno errno EMFILE10662999
Ref: 323b10662999
Ref: library/errno errno ENOTTY10663049
Ref: 323c10663049
Ref: library/errno errno ETXTBSY10663096
Ref: 323d10663096
Ref: library/errno errno EFBIG10663142
Ref: 323e10663142
Ref: library/errno errno ENOSPC10663186
Ref: 323f10663186
Ref: library/errno errno ESPIPE10663240
Ref: 324010663240
Ref: library/errno errno EROFS10663283
Ref: 324110663283
Ref: library/errno errno EMLINK10663334
Ref: 324210663334
Ref: library/errno errno EPIPE10663379
Ref: 26e610663379
Ref: library/errno errno EDOM10663494
Ref: 324310663494
Ref: library/errno errno ERANGE10663558
Ref: 324410663558
Ref: library/errno errno EDEADLK10663618
Ref: 324510663618
Ref: library/errno errno ENAMETOOLONG10663679
Ref: 324610663679
Ref: library/errno errno ENOLCK10663734
Ref: 324710663734
Ref: library/errno errno ENOSYS10663790
Ref: 1b3f10663790
Ref: library/errno errno ENOTEMPTY10663845
Ref: 324810663845
Ref: library/errno errno ELOOP10663898
Ref: 324910663898
Ref: library/errno errno EWOULDBLOCK10663963
Ref: 26e210663963
Ref: library/errno errno ENOMSG10664093
Ref: 324a10664093
Ref: library/errno errno EIDRM10664150
Ref: 324b10664150
Ref: library/errno errno ECHRNG10664198
Ref: 324c10664198
Ref: library/errno errno EL2NSYNC10664256
Ref: 324d10664256
Ref: library/errno errno EL3HLT10664313
Ref: 324e10664313
Ref: library/errno errno EL3RST10664358
Ref: 324f10664358
Ref: library/errno errno ELNRNG10664402
Ref: 325010664402
Ref: library/errno errno EUNATCH10664457
Ref: 325110664457
Ref: library/errno errno ENOCSI10664517
Ref: 325210664517
Ref: library/errno errno EL2HLT10664574
Ref: 325310664574
Ref: library/errno errno EBADE10664619
Ref: 325410664619
Ref: library/errno errno EBADR10664665
Ref: 325510664665
Ref: library/errno errno EXFULL10664721
Ref: 325610664721
Ref: library/errno errno ENOANO10664765
Ref: 325710664765
Ref: library/errno errno EBADRQC10664804
Ref: 325810664804
Ref: library/errno errno EBADSLT10664856
Ref: 325910664856
Ref: library/errno errno EDEADLOCK10664900
Ref: 325a10664900
Ref: library/errno errno EBFONT10664961
Ref: 325b10664961
Ref: library/errno errno ENOSTR10665012
Ref: 325c10665012
Ref: library/errno errno ENODATA10665062
Ref: 325d10665062
Ref: library/errno errno ETIME10665111
Ref: 325e10665111
Ref: library/errno errno ENOSR10665154
Ref: 325f10665154
Ref: library/errno errno ENONET10665208
Ref: 326010665208
Ref: library/errno errno ENOPKG10665268
Ref: 326110665268
Ref: library/errno errno EREMOTE10665320
Ref: 326210665320
Ref: library/errno errno ENOLINK10665368
Ref: 326310665368
Ref: library/errno errno EADV10665421
Ref: 326410665421
Ref: library/errno errno ESRMNT10665465
Ref: 326510665465
Ref: library/errno errno ECOMM10665509
Ref: 326610665509
Ref: library/errno errno EPROTO10665566
Ref: 326710665566
Ref: library/errno errno EMULTIHOP10665611
Ref: 326810665611
Ref: library/errno errno EDOTDOT10665663
Ref: 326910665663
Ref: library/errno errno EBADMSG10665713
Ref: 326a10665713
Ref: library/errno errno EOVERFLOW10665763
Ref: 326b10665763
Ref: library/errno errno ENOTUNIQ10665834
Ref: 326c10665834
Ref: library/errno errno EBADFD10665893
Ref: 326d10665893
Ref: library/errno errno EREMCHG10665952
Ref: 326e10665952
Ref: library/errno errno ELIBACC10666006
Ref: 326f10666006
Ref: library/errno errno ELIBBAD10666076
Ref: 327010666076
Ref: library/errno errno ELIBSCN10666144
Ref: 327110666144
Ref: library/errno errno ELIBMAX10666207
Ref: 327210666207
Ref: library/errno errno ELIBEXEC10666286
Ref: 327310666286
Ref: library/errno errno EILSEQ10666356
Ref: 327410666356
Ref: library/errno errno ERESTART10666408
Ref: 327510666408
Ref: library/errno errno ESTRPIPE10666484
Ref: 327610666484
Ref: library/errno errno EUSERS10666535
Ref: 327710666535
Ref: library/errno errno ENOTSOCK10666580
Ref: 327810666580
Ref: library/errno errno EDESTADDRREQ10666643
Ref: 327910666643
Ref: library/errno errno EMSGSIZE10666708
Ref: 327a10666708
Ref: library/errno errno EPROTOTYPE10666757
Ref: 327b10666757
Ref: library/errno errno ENOPROTOOPT10666822
Ref: 327c10666822
Ref: library/errno errno EPROTONOSUPPORT10666880
Ref: 327d10666880
Ref: library/errno errno ESOCKTNOSUPPORT10666942
Ref: 327e10666942
Ref: library/errno errno EOPNOTSUPP10667007
Ref: 327f10667007
Ref: library/errno errno ENOTSUP10667087
Ref: 328010667087
Ref: library/errno errno EPFNOSUPPORT10667170
Ref: 328110667170
Ref: library/errno errno EAFNOSUPPORT10667236
Ref: 328210667236
Ref: library/errno errno EADDRINUSE10667313
Ref: 328310667313
Ref: library/errno errno EADDRNOTAVAIL10667370
Ref: 328410667370
Ref: library/errno errno ENETDOWN10667439
Ref: 328510667439
Ref: library/errno errno ENETUNREACH10667487
Ref: 1dd110667487
Ref: library/errno errno ENETRESET10667545
Ref: 328610667545
Ref: library/errno errno ECONNABORTED10667622
Ref: 26e810667622
Ref: library/errno errno ECONNRESET10667772
Ref: 26ea10667772
Ref: library/errno errno ENOBUFS10667910
Ref: 1b5910667910
Ref: library/errno errno EISCONN10667967
Ref: 328710667967
Ref: library/errno errno ENOTCONN10668038
Ref: 328810668038
Ref: library/errno errno ESHUTDOWN10668106
Ref: 26e710668106
Ref: library/errno errno ETOOMANYREFS10668259
Ref: 328910668259
Ref: library/errno errno ETIMEDOUT10668330
Ref: 26f110668330
Ref: library/errno errno ECONNREFUSED10668454
Ref: 26e910668454
Ref: library/errno errno EHOSTDOWN10668590
Ref: 328a10668590
Ref: library/errno errno EHOSTUNREACH10668636
Ref: 328b10668636
Ref: library/errno errno EHWPOISON10668689
Ref: 20b10668689
Ref: library/errno errno EALREADY10668783
Ref: 26e110668783
Ref: library/errno errno EINPROGRESS10668918
Ref: 26e310668918
Ref: library/errno errno ESTALE10669052
Ref: 328c10669052
Ref: library/errno errno EUCLEAN10669104
Ref: 328d10669104
Ref: library/errno errno ENOTNAM10669160
Ref: 328e10669160
Ref: library/errno errno ENAVAIL10669219
Ref: 328f10669219
Ref: library/errno errno EISNAM10669280
Ref: 329010669280
Ref: library/errno errno EREMOTEIO10669331
Ref: 329110669331
Ref: library/errno errno EDQUOT10669381
Ref: 329210669381
Ref: library/errno errno EQFULL10669426
Ref: 329310669426
Ref: library/errno errno ENOMEDIUM10669516
Ref: 329410669516
Ref: library/errno errno EMEDIUMTYPE10669565
Ref: 329510669565
Ref: library/errno errno ENOKEY10669618
Ref: 329610669618
Ref: library/errno errno EKEYEXPIRED10669675
Ref: 329710669675
Ref: library/errno errno EKEYREVOKED10669726
Ref: 329810669726
Ref: library/errno errno EKEYREJECTED10669782
Ref: 329910669782
Ref: library/errno errno ERFKILL10669846
Ref: 329a10669846
Ref: library/errno errno ELOCKUNMAPPED10669915
Ref: 329b10669915
Ref: library/errno errno ENOTACTIVE10669977
Ref: 329c10669977
Ref: library/errno errno EAUTH10670034
Ref: 329d10670034
Ref: library/errno errno EBADARCH10670112
Ref: 329e10670112
Ref: library/errno errno EBADEXEC10670199
Ref: 329f10670199
Ref: library/errno errno EBADMACHO10670294
Ref: 32a010670294
Ref: library/errno errno EDEVERR10670377
Ref: 32a110670377
Ref: library/errno errno EFTYPE10670449
Ref: 32a210670449
Ref: library/errno errno ENEEDAUTH10670541
Ref: 32a310670541
Ref: library/errno errno ENOATTR10670621
Ref: 32a410670621
Ref: library/errno errno ENOPOLICY10670700
Ref: 32a510670700
Ref: library/errno errno EPROCLIM10670778
Ref: 32a610670778
Ref: library/errno errno EPROCUNAVAIL10670857
Ref: 32a710670857
Ref: library/errno errno EPROGMISMATCH10670947
Ref: 32a810670947
Ref: library/errno errno EPROGUNAVAIL10671034
Ref: 32a910671034
Ref: library/errno errno EPWROFF10671119
Ref: 32aa10671119
Ref: library/errno errno EBADRPC10671198
Ref: 32ab10671198
Ref: library/errno errno ERPCMISMATCH10671275
Ref: 32ac10671275
Ref: library/errno errno ESHLIBVERS10671357
Ref: 32ad10671357
Ref: library/errno errno ENOTCAPABLE10671451
Ref: 1b2710671451
Ref: library/errno errno ECANCELED10671663
Ref: 17aa10671663
Ref: library/errno errno EOWNERDEAD10671743
Ref: 32ae10671743
Ref: library/errno errno ENOTRECOVERABLE10671816
Ref: 32af10671816
Node: ctypes — A foreign function library for Python10671905
Ref: library/ctypes doc10672071
Ref: 32b010672071
Ref: library/ctypes ctypes-a-foreign-function-library-for-python10672071
Ref: 32b110672071
Ref: library/ctypes module-ctypes10672071
Ref: 2e10672071
Ref: library/ctypes translation-repo10672071
Ref: 32b210672071
Ref: ctypes — A foreign function library for Python-Footnote-110672842
Node: ctypes tutorial10672905
Ref: library/ctypes ctypes-ctypes-tutorial10673030
Ref: 32b310673030
Ref: library/ctypes ctypes-tutorial10673030
Ref: 32b410673030
Node: Loading dynamic link libraries10674515
Ref: library/ctypes ctypes-loading-dynamic-link-libraries10674642
Ref: 32b710674642
Ref: library/ctypes loading-dynamic-link-libraries10674642
Ref: 32b810674642
Node: Accessing functions from loaded dlls10676705
Ref: library/ctypes accessing-functions-from-loaded-dlls10676858
Ref: 32ba10676858
Ref: library/ctypes ctypes-accessing-functions-from-loaded-dlls10676858
Ref: 32bb10676858
Node: Calling functions10679080
Ref: library/ctypes calling-functions10679225
Ref: 32bc10679225
Ref: library/ctypes ctypes-calling-functions10679225
Ref: 32bd10679225
Node: Fundamental data types10681661
Ref: library/ctypes ctypes-fundamental-data-types10681797
Ref: 32be10681797
Ref: library/ctypes fundamental-data-types10681797
Ref: 32bf10681797
Node: Calling functions continued10692923
Ref: library/ctypes calling-functions-continued10693068
Ref: 32d410693068
Ref: library/ctypes ctypes-calling-functions-continued10693068
Ref: 32d510693068
Node: Calling variadic functions10694146
Ref: library/ctypes calling-variadic-functions10694318
Ref: 32d610694318
Ref: library/ctypes ctypes-calling-variadic-functions10694318
Ref: 32d710694318
Node: Calling functions with your own custom data types10695013
Ref: library/ctypes calling-functions-with-your-own-custom-data-types10695216
Ref: 32d810695216
Ref: library/ctypes ctypes-calling-functions-with-own-custom-data-types10695216
Ref: 32d910695216
Node: Specifying the required argument types function prototypes10696133
Ref: library/ctypes ctypes-specifying-required-argument-types10696322
Ref: 32da10696322
Ref: library/ctypes specifying-the-required-argument-types-function-prototypes10696322
Ref: 32db10696322
Node: Return types10698223
Ref: library/ctypes ctypes-return-types10698414
Ref: 32dd10698414
Ref: library/ctypes return-types10698414
Ref: 32de10698414
Node: Passing pointers or passing parameters by reference10701537
Ref: library/ctypes ctypes-passing-pointers10701691
Ref: 32e210701691
Ref: library/ctypes passing-pointers-or-passing-parameters-by-reference10701691
Ref: 32e310701691
Node: Structures and unions10702783
Ref: library/ctypes ctypes-structures-unions10702972
Ref: 32e510702972
Ref: library/ctypes structures-and-unions10702972
Ref: 32e610702972
Ref: library/ctypes ctypes-structureunion-alignment-byte-order10705094
Ref: 32e710705094
Node: Structure/union layout alignment and byte order10705427
Ref: library/ctypes structure-union-layout-alignment-and-byte-order10705600
Ref: 32e810705600
Node: Bit fields in structures and unions10706556
Ref: library/ctypes bit-fields-in-structures-and-unions10706714
Ref: 32eb10706714
Ref: library/ctypes ctypes-bit-fields-in-structures-unions10706714
Ref: 1e410706714
Node: Arrays10707718
Ref: library/ctypes arrays10707837
Ref: 32ec10707837
Ref: library/ctypes ctypes-arrays10707837
Ref: 32ed10707837
Node: Pointers10709124
Ref: library/ctypes ctypes-pointers10709237
Ref: 32ee10709237
Ref: library/ctypes pointers10709237
Ref: 32ef10709237
Node: Thread safety without the GIL10711897
Ref: library/ctypes ctypes-thread-safety10712020
Ref: 32f110712020
Ref: library/ctypes thread-safety-without-the-gil10712020
Ref: 32f210712020
Node: Type conversions10713027
Ref: library/ctypes ctypes-type-conversions10713158
Ref: 32f310713158
Ref: library/ctypes type-conversions10713158
Ref: 32f410713158
Node: Incomplete Types10715772
Ref: library/ctypes ctypes-incomplete-types10715892
Ref: 31810715892
Ref: library/ctypes incomplete-types10715892
Ref: 32f610715892
Node: Callback functions10717506
Ref: library/ctypes callback-functions10717645
Ref: 32f710717645
Ref: library/ctypes ctypes-callback-functions10717645
Ref: 32f810717645
Node: Accessing values exported from dlls10721517
Ref: library/ctypes accessing-values-exported-from-dlls10721649
Ref: 32fb10721649
Ref: library/ctypes ctypes-accessing-values-exported-from-dlls10721649
Ref: 32fc10721649
Node: Surprises10724308
Ref: library/ctypes ctypes-surprises10724447
Ref: 32ff10724447
Ref: library/ctypes surprises10724447
Ref: 330010724447
Node: Variable-sized data types10726620
Ref: library/ctypes ctypes-variable-sized-data-types10726715
Ref: 330110726715
Ref: library/ctypes variable-sized-data-types10726715
Ref: 330210726715
Node: ctypes reference10728116
Ref: library/ctypes ctypes-ctypes-reference10728241
Ref: 330410728241
Ref: library/ctypes ctypes-reference10728241
Ref: 330510728241
Node: Finding shared libraries10728615
Ref: library/ctypes ctypes-finding-shared-libraries10728732
Ref: 330610728732
Ref: library/ctypes finding-shared-libraries10728732
Ref: 330710728732
Node: Listing loaded shared libraries10731455
Ref: library/ctypes ctypes-listing-loaded-shared-libraries10731605
Ref: 330810731605
Ref: library/ctypes listing-loaded-shared-libraries10731605
Ref: 330910731605
Node: Loading shared libraries10732494
Ref: library/ctypes ctypes-loading-shared-libraries10732637
Ref: 330a10732637
Ref: library/ctypes loading-shared-libraries10732637
Ref: 330b10732637
Ref: library/ctypes ctypes CDLL10732838
Ref: bde10732838
Ref: library/ctypes ctypes OleDLL10733979
Ref: 1aca10733979
Ref: library/ctypes ctypes WinDLL10734855
Ref: 1acb10734855
Ref: library/ctypes ctypes PyDLL10735461
Ref: 1acc10735461
Ref: library/ctypes ctypes PyDLL _handle10739309
Ref: 331110739309
Ref: library/ctypes ctypes PyDLL _name10739391
Ref: 331210739391
Ref: library/ctypes ctypes LibraryLoader10739740
Ref: 331310739740
Ref: library/ctypes ctypes LibraryLoader LoadLibrary10740199
Ref: 32b910740199
Ref: Loading shared libraries-Footnote-110741823
Ref: Loading shared libraries-Footnote-210741889
Node: Foreign functions10741935
Ref: library/ctypes ctypes-foreign-functions10742066
Ref: 331410742066
Ref: library/ctypes foreign-functions10742066
Ref: 331510742066
Ref: library/ctypes ctypes _CFuncPtr10742762
Ref: 18ba10742762
Ref: library/ctypes ctypes _CFuncPtr restype10743065
Ref: 32df10743065
Ref: library/ctypes ctypes _CFuncPtr argtypes10743742
Ref: 17a910743742
Ref: library/ctypes ctypes _CFuncPtr errcheck10745005
Ref: 32e110745005
Node: Function prototypes10746533
Ref: library/ctypes ctypes-function-prototypes10746657
Ref: 331610746657
Ref: library/ctypes function-prototypes10746657
Ref: 331710746657
Ref: library/ctypes ctypes CFUNCTYPE10747238
Ref: 32f910747238
Ref: library/ctypes ctypes WINFUNCTYPE10747749
Ref: 32fa10747749
Ref: library/ctypes ctypes PYFUNCTYPE10748130
Ref: 331810748130
Node: Utility functions10753811
Ref: library/ctypes ctypes-utility-functions10753928
Ref: 331910753928
Ref: library/ctypes utility-functions10753928
Ref: 331a10753928
Ref: library/ctypes ctypes addressof10753985
Ref: 331b10753985
Ref: library/ctypes ctypes alignment10754229
Ref: 331c10754229
Ref: library/ctypes ctypes byref10754389
Ref: 32e410754389
Ref: library/ctypes ctypes CopyComPointer10754903
Ref: 1ea10754903
Ref: library/ctypes ctypes cast10755498
Ref: 32f510755498
Ref: library/ctypes ctypes create_string_buffer10755792
Ref: 32d310755792
Ref: library/ctypes ctypes create_unicode_buffer10757304
Ref: 1d9c10757304
Ref: library/ctypes ctypes DllCanUnloadNow10757835
Ref: 331d10757835
Ref: library/ctypes ctypes DllGetClassObject10758107
Ref: 331e10758107
Ref: library/ctypes ctypes util find_library10758389
Ref: f4710758389
Ref: library/ctypes ctypes util find_msvcrt10758862
Ref: 331f10758862
Ref: library/ctypes ctypes util dllist10759346
Ref: 1f010759346
Ref: library/ctypes ctypes FormatError10759920
Ref: 332010759920
Ref: library/ctypes ctypes GetLastError10760200
Ref: 32e010760200
Ref: library/ctypes ctypes get_errno10760495
Ref: 330d10760495
Ref: library/ctypes ctypes get_last_error10760748
Ref: 330f10760748
Ref: library/ctypes ctypes memmove10761051
Ref: 332110761051
Ref: library/ctypes ctypes memset10761295
Ref: 332210761295
Ref: library/ctypes ctypes POINTER10761548
Ref: 1f110761548
Ref: library/ctypes ctypes pointer10762234
Ref: 1a3e10762234
Ref: library/ctypes ctypes resize10762543
Ref: 330310762543
Ref: library/ctypes ctypes set_errno10762881
Ref: 330e10762881
Ref: library/ctypes ctypes set_last_error10763189
Ref: 331010763189
Ref: library/ctypes ctypes sizeof10763548
Ref: 332310763548
Ref: library/ctypes ctypes string_at10763719
Ref: 1ec10763719
Ref: library/ctypes ctypes WinError10764031
Ref: 332410764031
Ref: library/ctypes ctypes wstring_at10764548
Ref: 332510764548
Ref: library/ctypes ctypes memoryview_at10764906
Ref: 1eb10764906
Node: Data types10765875
Ref: library/ctypes ctypes-data-types10765998
Ref: 332710765998
Ref: library/ctypes data-types10765998
Ref: 332810765998
Ref: library/ctypes ctypes _CData10766041
Ref: 332910766041
Ref: library/ctypes ctypes _CData from_buffer10766677
Ref: 332b10766677
Ref: library/ctypes ctypes _CData from_buffer_copy10767264
Ref: 332c10767264
Ref: library/ctypes ctypes _CData from_address10767809
Ref: 332610767809
Ref: library/ctypes ctypes _CData from_param10768155
Ref: 32dc10768155
Ref: library/ctypes ctypes _CData in_dll10768716
Ref: 32fd10768716
Ref: library/ctypes ctypes _CData __pointer_type__10769009
Ref: 1f210769009
Ref: library/ctypes ctypes _CData _b_base_10769335
Ref: 332d10769335
Ref: library/ctypes ctypes _CData _b_needsfree_10769640
Ref: 332e10769640
Ref: library/ctypes ctypes _CData _objects10769814
Ref: 332a10769814
Node: Fundamental data types<2>10770126
Ref: library/ctypes ctypes-fundamental-data-types-210770253
Ref: 332f10770253
Ref: library/ctypes id110770253
Ref: 333010770253
Ref: library/ctypes ctypes _SimpleCData10770320
Ref: 333110770320
Ref: library/ctypes ctypes _SimpleCData value10770794
Ref: 333210770794
Ref: library/ctypes ctypes c_byte10772156
Ref: 1ac810772156
Ref: library/ctypes ctypes c_char10772369
Ref: 32c110772369
Ref: library/ctypes ctypes c_char_p10772610
Ref: 1a3f10772610
Ref: library/ctypes ctypes c_double10772905
Ref: 1ca010772905
Ref: library/ctypes ctypes c_longdouble10773035
Ref: 1ca110773035
Ref: library/ctypes ctypes c_float10773283
Ref: 32d210773283
Ref: library/ctypes ctypes c_double_complex10773411
Ref: 1ee10773411
Ref: library/ctypes ctypes c_float_complex10773614
Ref: 1ed10773614
Ref: library/ctypes ctypes c_longdouble_complex10773815
Ref: 1ef10773815
Ref: library/ctypes ctypes c_int10774027
Ref: 32b510774027
Ref: library/ctypes ctypes c_int810774292
Ref: 32c510774292
Ref: library/ctypes ctypes c_int1610774414
Ref: 32c610774414
Ref: library/ctypes ctypes c_int3210774541
Ref: 32c710774541
Ref: library/ctypes ctypes c_int6410774666
Ref: 32c810774666
Ref: library/ctypes ctypes c_long10774796
Ref: 32b610774796
Ref: library/ctypes ctypes c_longlong10774961
Ref: 32cf10774961
Ref: library/ctypes ctypes c_short10775140
Ref: 32c310775140
Ref: library/ctypes ctypes c_size_t10775307
Ref: 32d110775307
Ref: library/ctypes ctypes c_ssize_t10775382
Ref: 144410775382
Ref: library/ctypes ctypes c_time_t10775487
Ref: 1b4b10775487
Ref: library/ctypes ctypes c_ubyte10775591
Ref: 1ac910775591
Ref: library/ctypes ctypes c_uint10775806
Ref: 32c910775806
Ref: library/ctypes ctypes c_uint810776076
Ref: 32ca10776076
Ref: library/ctypes ctypes c_uint1610776202
Ref: 32cb10776202
Ref: library/ctypes ctypes c_uint3210776333
Ref: 32cc10776333
Ref: library/ctypes ctypes c_uint6410776462
Ref: 32cd10776462
Ref: library/ctypes ctypes c_ulong10776596
Ref: 32ce10776596
Ref: library/ctypes ctypes c_ulonglong10776764
Ref: 32d010776764
Ref: library/ctypes ctypes c_ushort10776946
Ref: 32c410776946
Ref: library/ctypes ctypes c_void_p10777116
Ref: 1a4110777116
Ref: library/ctypes ctypes c_wchar10777280
Ref: 32c210777280
Ref: library/ctypes ctypes c_wchar_p10777546
Ref: 1a4010777546
Ref: library/ctypes ctypes c_bool10777754
Ref: 32c010777754
Ref: library/ctypes ctypes HRESULT10777969
Ref: 330c10777969
Ref: library/ctypes ctypes py_object10778158
Ref: 1f310778158
Node: Structured data types10778639
Ref: library/ctypes ctypes-structured-data-types10778775
Ref: 333310778775
Ref: library/ctypes structured-data-types10778775
Ref: 333410778775
Ref: library/ctypes ctypes Union10778840
Ref: 1e610778840
Ref: library/ctypes ctypes BigEndianUnion10779064
Ref: 1b9f10779064
Ref: library/ctypes ctypes LittleEndianUnion10779207
Ref: 1ba010779207
Ref: library/ctypes ctypes BigEndianStructure10779356
Ref: 32e910779356
Ref: library/ctypes ctypes LittleEndianStructure10779478
Ref: 32ea10779478
Ref: library/ctypes ctypes Structure10779748
Ref: 1e510779748
Ref: library/ctypes ctypes Structure _fields_10780173
Ref: 191e10780173
Ref: library/ctypes ctypes Structure _pack_10782038
Ref: 31710782038
Ref: library/ctypes ctypes Structure _align_10783139
Ref: 4e910783139
Ref: library/ctypes ctypes Structure _layout_10783979
Ref: 1e710783979
Ref: library/ctypes ctypes Structure _anonymous_10785264
Ref: 333510785264
Ref: library/ctypes ctypes CField10787620
Ref: 1e810787620
Ref: library/ctypes ctypes CField name10788782
Ref: 333610788782
Ref: library/ctypes ctypes CField type10788851
Ref: 333710788851
Ref: library/ctypes ctypes CField offset10788938
Ref: 333810788938
Ref: library/ctypes ctypes CField byte_offset10788965
Ref: 333910788965
Ref: library/ctypes ctypes CField byte_size10789170
Ref: 333b10789170
Ref: library/ctypes ctypes CField size10789397
Ref: 333c10789397
Ref: library/ctypes ctypes CField is_bitfield10789711
Ref: 333e10789711
Ref: library/ctypes ctypes CField bit_offset10789783
Ref: 333a10789783
Ref: library/ctypes ctypes CField bit_size10789814
Ref: 333d10789814
Ref: library/ctypes ctypes CField is_anonymous10790330
Ref: 333f10790330
Node: Arrays and pointers10790527
Ref: library/ctypes arrays-and-pointers10790651
Ref: 334010790651
Ref: library/ctypes ctypes-arrays-pointers10790651
Ref: 334110790651
Ref: library/ctypes ctypes Array10790712
Ref: 1df410790712
Ref: library/ctypes ctypes Array _length_10791227
Ref: 334210791227
Ref: library/ctypes ctypes Array _type_10791456
Ref: 334310791456
Ref: library/ctypes ctypes ARRAY10791654
Ref: 59e10791654
Ref: library/ctypes ctypes _Pointer10791950
Ref: 334410791950
Ref: library/ctypes ctypes _Pointer _type_10792608
Ref: 183810792608
Ref: library/ctypes ctypes _Pointer contents10792678
Ref: 32f010792678
Node: Exceptions<9>10792868
Ref: library/ctypes ctypes-exceptions10792962
Ref: 334510792962
Ref: library/ctypes exceptions10792962
Ref: 334610792962
Ref: library/ctypes ctypes ArgumentError10793005
Ref: 334710793005
Ref: library/ctypes ctypes COMError10793151
Ref: 1e910793151
Ref: library/ctypes ctypes COMError hresult10793270
Ref: 334810793270
Ref: library/ctypes ctypes COMError text10793357
Ref: 334910793357
Ref: library/ctypes ctypes COMError details10793413
Ref: 334a10793413
Node: Command-line interface libraries10793936
Ref: library/cmdlinelibs doc10794103
Ref: 334b10794103
Ref: library/cmdlinelibs cmdlinelibs10794103
Ref: 334c10794103
Ref: library/cmdlinelibs command-line-interface-libraries10794103
Ref: 334d10794103
Ref: library/cmdlinelibs translation-repo10794103
Ref: 334e10794103
Node: argparse — Parser for command-line options arguments and subcommands10795079
Ref: library/argparse doc10795271
Ref: 334f10795271
Ref: library/argparse argparse-parser-for-command-line-options-arguments-and-subcommands10795271
Ref: 335010795271
Ref: library/argparse module-argparse10795271
Ref: 710795271
Ref: argparse — Parser for command-line options arguments and subcommands-Footnote-110798340
Node: ArgumentParser objects10798408
Ref: library/argparse argumentparser-objects10798569
Ref: 335510798569
Ref: library/argparse argparse ArgumentParser10798634
Ref: 1bd10798634
Node: prog10801850
Ref: library/argparse id110801927
Ref: 336310801927
Ref: library/argparse prog10801927
Ref: 1bc10801927
Node: usage10803648
Ref: library/argparse usage10803745
Ref: 335610803745
Node: description10804785
Ref: library/argparse description10804884
Ref: 335710804884
Ref: library/argparse id210804884
Ref: 336410804884
Node: epilog10805417
Ref: library/argparse epilog10805518
Ref: 335810805518
Node: parents10806286
Ref: library/argparse parents10806391
Ref: 335910806391
Node: formatter_class10807843
Ref: library/argparse formatter-class10807954
Ref: 335a10807954
Ref: library/argparse id310807954
Ref: 336510807954
Ref: library/argparse argparse RawDescriptionHelpFormatter10808170
Ref: 336610808170
Ref: library/argparse argparse RawTextHelpFormatter10808219
Ref: 336710808219
Ref: library/argparse argparse ArgumentDefaultsHelpFormatter10808261
Ref: 1c3810808261
Ref: library/argparse argparse MetavarTypeHelpFormatter10808312
Ref: 336810808312
Node: prefix_chars10811779
Ref: library/argparse prefix-chars10811904
Ref: 335b10811904
Node: fromfile_prefix_chars10812652
Ref: library/argparse fromfile-prefix-chars10812778
Ref: 335c10812778
Node: argument_default10814759
Ref: library/argparse argument-default10814885
Ref: 335d10814885
Node: allow_abbrev10815771
Ref: library/argparse allow-abbrev10815892
Ref: fc110815892
Ref: library/argparse id410815892
Ref: 336d10815892
Node: conflict_handler10816545
Ref: library/argparse conflict-handler10816658
Ref: 335e10816658
Node: add_help10818205
Ref: library/argparse add-help10818319
Ref: 335f10818319
Node: exit_on_error10819482
Ref: library/argparse exit-on-error10819596
Ref: 336010819596
Node: suggest_on_error10820478
Ref: library/argparse suggest-on-error10820589
Ref: 336110820589
Node: color10822071
Ref: library/argparse color10822160
Ref: 336210822160
Ref: color-Footnote-110823383
Ref: color-Footnote-210823438
Node: The add_argument method10823468
Ref: library/argparse the-add-argument-method10823659
Ref: 336e10823659
Ref: library/argparse argparse ArgumentParser add_argument10823732
Ref: 4bd10823732
Node: name or flags10825712
Ref: library/argparse id510825800
Ref: 337410825800
Ref: library/argparse name-or-flags10825800
Ref: 336f10825800
Node: action10827765
Ref: library/argparse action10827867
Ref: 191310827867
Ref: library/argparse id610827867
Ref: 337510827867
Node: nargs10834145
Ref: library/argparse id710834239
Ref: 337710834239
Ref: library/argparse nargs10834239
Ref: 191910834239
Node: const10838162
Ref: library/argparse const10838257
Ref: 191b10838257
Ref: library/argparse id810838257
Ref: 337910838257
Node: default10839529
Ref: library/argparse default10839623
Ref: 191a10839623
Ref: library/argparse id910839623
Ref: 337a10839623
Node: type10842067
Ref: library/argparse argparse-type10842163
Ref: 337b10842163
Ref: library/argparse type10842163
Ref: 336910842163
Node: choices10845071
Ref: library/argparse choices10845168
Ref: 191510845168
Ref: library/argparse id1010845168
Ref: 337d10845168
Node: required10846942
Ref: library/argparse id1110847039
Ref: 337e10847039
Ref: library/argparse required10847039
Ref: 337010847039
Node: help10847994
Ref: library/argparse help10848091
Ref: 337110848091
Ref: library/argparse id1210848091
Ref: 337f10848091
Node: metavar10849600
Ref: library/argparse id1310849693
Ref: 338010849693
Ref: library/argparse metavar10849693
Ref: 337210849693
Node: dest10851906
Ref: library/argparse dest10852005
Ref: 336a10852005
Ref: library/argparse id1410852005
Ref: 338110852005
Node: deprecated10853638
Ref: library/argparse deprecated10853744
Ref: 337310853744
Ref: library/argparse id1510853744
Ref: 338210853744
Node: Action classes10854658
Ref: library/argparse action-classes10854751
Ref: 338310854751
Ref: library/argparse argparse Action10855044
Ref: 1b7410855044
Ref: library/argparse argparse Action __call__10855939
Ref: 338410855939
Ref: library/argparse argparse Action format_usage10857233
Ref: 338510857233
Ref: library/argparse argparse BooleanOptionalAction10857541
Ref: 1bda10857541
Node: The parse_args method10858132
Ref: library/argparse the-parse-args-method10858316
Ref: 338610858316
Ref: library/argparse argparse ArgumentParser parse_args10858385
Ref: 335310858385
Node: Option value syntax10859254
Ref: library/argparse option-value-syntax10859357
Ref: 338910859357
Node: Invalid arguments10860754
Ref: library/argparse invalid-arguments10860888
Ref: 338a10860888
Node: Arguments containing -10861873
Ref: library/argparse arguments-containing10862026
Ref: 338b10862026
Node: Argument abbreviations prefix matching10864114
Ref: library/argparse argument-abbreviations-prefix-matching10864265
Ref: 338c10864265
Ref: library/argparse prefix-matching10864265
Ref: fc010864265
Node: Beyond sys argv10865193
Ref: library/argparse args10865342
Ref: 338710865342
Ref: library/argparse beyond-sys-argv10865342
Ref: 338d10865342
Node: The Namespace object10866304
Ref: library/argparse namespace10866406
Ref: 338810866406
Ref: library/argparse the-namespace-object10866406
Ref: 338e10866406
Ref: library/argparse argparse Namespace10866469
Ref: 335410866469
Node: Other utilities10867605
Ref: library/argparse other-utilities10867780
Ref: 338f10867780
Node: Subcommands10868091
Ref: library/argparse subcommands10868179
Ref: 339010868179
Ref: library/argparse argparse ArgumentParser add_subparsers10868224
Ref: e1310868224
Node: FileType objects10877742
Ref: library/argparse filetype-objects10877854
Ref: 339110877854
Ref: library/argparse argparse FileType10877909
Ref: 30c10877909
Node: Argument groups10879799
Ref: library/argparse argument-groups10879916
Ref: 339210879916
Ref: library/argparse argparse ArgumentParser add_argument_group10879969
Ref: 2eb10879969
Node: Mutual exclusion10882867
Ref: library/argparse mutual-exclusion10882983
Ref: 339310882983
Ref: library/argparse argparse ArgumentParser add_mutually_exclusive_group10883038
Ref: 2ed10883038
Node: Parser defaults10885751
Ref: library/argparse parser-defaults10885865
Ref: 339410885865
Ref: library/argparse argparse ArgumentParser set_defaults10885918
Ref: 336c10885918
Ref: library/argparse argparse ArgumentParser get_default10887216
Ref: 339510887216
Node: Printing help10887572
Ref: library/argparse printing-help10887685
Ref: 339610887685
Ref: library/argparse argparse ArgumentParser print_usage10887914
Ref: 339710887914
Ref: library/argparse argparse ArgumentParser print_help10888146
Ref: 339810888146
Ref: library/argparse argparse ArgumentParser format_usage10888500
Ref: 1d9810888500
Ref: library/argparse argparse ArgumentParser format_help10888679
Ref: 339910888679
Node: Partial parsing10888892
Ref: library/argparse partial-parsing10889014
Ref: 339a10889014
Ref: library/argparse argparse ArgumentParser parse_known_args10889067
Ref: 339b10889067
Node: Customizing file parsing10890236
Ref: library/argparse customizing-file-parsing10890360
Ref: 339c10890360
Ref: library/argparse argparse ArgumentParser convert_arg_line_to_args10890431
Ref: 336b10890431
Node: Exiting methods10891336
Ref: library/argparse exiting-methods10891463
Ref: 339d10891463
Ref: library/argparse argparse ArgumentParser exit10891516
Ref: 339e10891516
Ref: library/argparse argparse ArgumentParser error10892079
Ref: 339f10892079
Node: Intermixed parsing10892278
Ref: library/argparse intermixed-parsing10892416
Ref: 33a010892416
Ref: library/argparse argparse ArgumentParser parse_intermixed_args10892475
Ref: cf910892475
Ref: library/argparse argparse ArgumentParser parse_known_intermixed_args10892563
Ref: 33a110892563
Node: Registering custom types or actions10894208
Ref: library/argparse registering-custom-types-or-actions10894322
Ref: 33a210894322
Ref: library/argparse argparse ArgumentParser register10894415
Ref: 337610894415
Node: Exceptions<10>10895883
Ref: library/argparse exceptions10896028
Ref: 33a310896028
Ref: library/argparse argparse ArgumentError10896071
Ref: 33a410896071
Ref: library/argparse argparse ArgumentTypeError10896315
Ref: 337c10896315
Node: Argparse Tutorial10896561
Ref: howto/argparse doc10896673
Ref: 33a510896673
Ref: howto/argparse argparse-tutorial10896673
Ref: 335210896673
Ref: howto/argparse id110896673
Ref: 33a610896673
Node: Concepts10897936
Ref: howto/argparse concepts10898017
Ref: 33a710898017
Node: The basics10900111
Ref: howto/argparse the-basics10900233
Ref: 33a810900233
Node: Introducing Positional arguments10901398
Ref: howto/argparse introducing-positional-arguments10901542
Ref: 33a910901542
Node: Introducing Optional arguments10904822
Ref: howto/argparse introducing-optional-arguments10904999
Ref: 33aa10904999
Node: Short options10907983
Ref: howto/argparse short-options10908063
Ref: 33ab10908063
Node: Combining Positional and Optional arguments10908856
Ref: howto/argparse combining-positional-and-optional-arguments10909031
Ref: 33ac10909031
Node: Getting a little more advanced10917103
Ref: howto/argparse getting-a-little-more-advanced10917284
Ref: 33ad10917284
Node: Specifying ambiguous arguments10919290
Ref: howto/argparse id210919415
Ref: 33ae10919415
Ref: howto/argparse specifying-ambiguous-arguments10919415
Ref: 337810919415
Node: Conflicting options10920371
Ref: howto/argparse conflicting-options10920496
Ref: 33af10920496
Node: How to translate the argparse output10923596
Ref: howto/argparse how-to-translate-the-argparse-output10923756
Ref: 33b010923756
Ref: How to translate the argparse output-Footnote-110925526
Node: Custom type converters10925559
Ref: howto/argparse custom-type-converters10925699
Ref: 33b210925699
Node: Conclusion10927465
Ref: howto/argparse conclusion10927560
Ref: 33b310927560
Ref: howto/argparse-optparse upgrading-optparse-code10927829
Ref: 13b610927829
Node: Migrating optparse code to argparse10927829
Ref: howto/argparse-optparse doc10927941
Ref: 33b410927941
Ref: howto/argparse-optparse migrating-optparse-code10927941
Ref: 33b510927941
Ref: howto/argparse-optparse migrating-optparse-code-to-argparse10927941
Ref: 33b610927941
Ref: howto/argparse-optparse translation-repo10927941
Ref: 33b710927941
Node: optparse — Parser for command line options10930960
Ref: library/optparse doc10931196
Ref: 33bd10931196
Ref: library/optparse module-optparse10931196
Ref: a410931196
Ref: library/optparse optparse-parser-for-command-line-options10931196
Ref: 33be10931196
Ref: library/optparse translation-repo10931196
Ref: 33bf10931196
Ref: optparse — Parser for command line options-Footnote-110931664
Node: Choosing an argument parsing library10931732
Ref: library/optparse choosing-an-argument-parser10931873
Ref: 335110931873
Ref: library/optparse choosing-an-argument-parsing-library10931873
Ref: 33c010931873
Ref: Choosing an argument parsing library-Footnote-110937513
Ref: Choosing an argument parsing library-Footnote-210937553
Ref: Choosing an argument parsing library-Footnote-310937593
Node: Introduction<6>10937641
Ref: library/optparse introduction10937801
Ref: 33c110937801
Node: Background10940230
Ref: library/optparse background10940365
Ref: 33c210940365
Ref: library/optparse optparse-background10940365
Ref: 33c310940365
Node: Terminology10940962
Ref: library/optparse optparse-terminology10941050
Ref: 33c410941050
Ref: library/optparse terminology10941050
Ref: 33c510941050
Node: What are options for?10944899
Ref: library/optparse optparse-what-options-for10945030
Ref: 33c610945030
Ref: library/optparse what-are-options-for10945030
Ref: 33c710945030
Node: What are positional arguments for?10946713
Ref: library/optparse optparse-what-positional-arguments-for10946824
Ref: 33c810946824
Ref: library/optparse what-are-positional-arguments-for10946824
Ref: 33c910946824
Node: Tutorial<2>10948157
Ref: library/optparse optparse-tutorial10948292
Ref: 33ca10948292
Ref: library/optparse tutorial10948292
Ref: 33cb10948292
Node: Understanding option actions10950911
Ref: library/optparse optparse-understanding-option-actions10951012
Ref: 33d010951012
Ref: library/optparse understanding-option-actions10951012
Ref: 33d110951012
Node: The store action10951603
Ref: library/optparse optparse-store-action10951742
Ref: 33d310951742
Ref: library/optparse the-store-action10951742
Ref: 33d410951742
Node: Handling boolean flag options10953938
Ref: library/optparse handling-boolean-flag-options10954062
Ref: 33d510954062
Ref: library/optparse optparse-handling-boolean-options10954062
Ref: 33d610954062
Node: Other actions10954947
Ref: library/optparse optparse-other-actions10955069
Ref: 33d710955069
Ref: library/optparse other-actions10955069
Ref: 33d810955069
Node: Default values10955528
Ref: library/optparse default-values10955636
Ref: 33dc10955636
Ref: library/optparse optparse-default-values10955636
Ref: 33dd10955636
Node: Generating help10957529
Ref: library/optparse generating-help10957649
Ref: 33de10957649
Ref: library/optparse optparse-generating-help10957649
Ref: 33df10957649
Node: Grouping Options10961817
Ref: library/optparse grouping-options10961885
Ref: 33e010961885
Ref: library/optparse optparse OptionGroup10962216
Ref: 33e110962216
Ref: library/optparse optparse OptionParser get_option_group10965715
Ref: 33e210965715
Node: Printing a version string10965985
Ref: library/optparse optparse-printing-version-string10966118
Ref: 33e310966118
Ref: library/optparse printing-a-version-string10966118
Ref: 33e410966118
Ref: library/optparse optparse OptionParser print_version10967002
Ref: 33e510967002
Ref: library/optparse optparse OptionParser get_version10967376
Ref: 33e710967376
Node: How optparse handles errors10967520
Ref: library/optparse how-optparse-handles-errors10967661
Ref: 33e810967661
Ref: library/optparse optparse-how-optparse-handles-errors10967661
Ref: 33e910967661
Node: Putting it all together10969751
Ref: library/optparse optparse-putting-it-all-together10969858
Ref: 33ea10969858
Ref: library/optparse putting-it-all-together10969858
Ref: 33eb10969858
Node: Reference Guide10970776
Ref: library/optparse optparse-reference-guide10970917
Ref: 33da10970917
Ref: library/optparse reference-guide10970917
Ref: 33ec10970917
Node: Creating the parser10971258
Ref: library/optparse creating-the-parser10971359
Ref: 33ed10971359
Ref: library/optparse optparse-creating-parser10971359
Ref: 33ee10971359
Ref: library/optparse optparse OptionParser10971504
Ref: 16d410971504
Node: Populating the parser10974511
Ref: library/optparse optparse-populating-parser10974637
Ref: 33f010974637
Ref: library/optparse populating-the-parser10974637
Ref: 33f110974637
Node: Defining options10975923
Ref: library/optparse defining-options10976047
Ref: 33f210976047
Ref: library/optparse optparse-defining-options10976047
Ref: 33f310976047
Ref: library/optparse optparse OptionParser add_option10976463
Ref: 33b810976463
Ref: library/optparse optparse Values10978554
Ref: 33ba10978554
Node: Option attributes10979801
Ref: library/optparse option-attributes10979927
Ref: 33f710979927
Ref: library/optparse optparse-option-attributes10979927
Ref: 33f810979927
Ref: library/optparse optparse Option10979984
Ref: 33f410979984
Ref: library/optparse optparse Option action10980603
Ref: 33cc10980603
Ref: library/optparse optparse Option type10980826
Ref: 33cd10980826
Ref: library/optparse optparse Option dest10981043
Ref: 33ce10981043
Ref: library/optparse optparse Option default10981388
Ref: 33fa10981388
Ref: library/optparse optparse Option nargs10981582
Ref: 33fc10981582
Ref: library/optparse optparse Option const10981815
Ref: 33d910981815
Ref: library/optparse optparse Option choices10981925
Ref: 33fd10981925
Ref: library/optparse optparse Option callback10982049
Ref: 33fe10982049
Ref: library/optparse optparse Option callback_args10982281
Ref: 33ff10982281
Ref: library/optparse optparse Option callback_kwargs10982317
Ref: 340010982317
Ref: library/optparse optparse Option help10982481
Ref: 33cf10982481
Ref: library/optparse optparse Option metavar10982829
Ref: 340110982829
Node: Standard option actions10983034
Ref: library/optparse optparse-standard-option-actions10983165
Ref: 33f510983165
Ref: library/optparse standard-option-actions10983165
Ref: 340210983165
Node: Standard option types10991252
Ref: library/optparse optparse-standard-option-types10991383
Ref: 33f910991383
Ref: library/optparse standard-option-types10991383
Ref: 340310991383
Node: Parsing arguments10992861
Ref: library/optparse optparse-parsing-arguments10993013
Ref: 33f610993013
Ref: library/optparse parsing-arguments10993013
Ref: 340410993013
Ref: library/optparse optparse OptionParser parse_args10993179
Ref: 16d510993179
Node: Querying and manipulating your option parser10994566
Ref: library/optparse optparse-querying-manipulating-option-parser10994722
Ref: 340510994722
Ref: library/optparse querying-and-manipulating-your-option-parser10994722
Ref: 340610994722
Ref: library/optparse optparse OptionParser disable_interspersed_args10995031
Ref: 33b910995031
Ref: library/optparse optparse OptionParser enable_interspersed_args10995821
Ref: 340710995821
Ref: library/optparse optparse OptionParser get_option10996027
Ref: 340810996027
Ref: library/optparse optparse OptionParser has_option10996200
Ref: 340910996200
Ref: library/optparse optparse OptionParser remove_option10996376
Ref: 340a10996376
Node: Conflicts between options10996762
Ref: library/optparse conflicts-between-options10996908
Ref: 340b10996908
Ref: library/optparse optparse-conflicts-between-options10996908
Ref: 33ef10996908
Node: Cleanup10999379
Ref: library/optparse cleanup10999494
Ref: 340d10999494
Ref: library/optparse optparse-cleanup10999494
Ref: 340e10999494
Node: Other methods10999907
Ref: library/optparse optparse-other-methods10999988
Ref: 340f10999988
Ref: library/optparse other-methods10999988
Ref: 341010999988
Ref: library/optparse optparse OptionParser set_usage11000090
Ref: 341111000090
Ref: library/optparse optparse OptionParser print_usage11000379
Ref: 33e611000379
Ref: library/optparse optparse OptionParser get_usage11000715
Ref: 341211000715
Ref: library/optparse optparse OptionParser set_defaults11000853
Ref: 33fb11000853
Node: Option Callbacks11002019
Ref: library/optparse option-callbacks11002167
Ref: 341311002167
Ref: library/optparse optparse-option-callbacks11002167
Ref: 33db11002167
Node: Defining a callback option11003384
Ref: library/optparse defining-a-callback-option11003496
Ref: 341411003496
Ref: library/optparse optparse-defining-callback-option11003496
Ref: 341511003496
Node: How callbacks are called11005721
Ref: library/optparse how-callbacks-are-called11005870
Ref: 341611005870
Ref: library/optparse optparse-how-callbacks-called11005870
Ref: 341711005870
Node: Raising errors in a callback11008486
Ref: library/optparse optparse-raising-errors-in-callback11008644
Ref: 341811008644
Ref: library/optparse raising-errors-in-a-callback11008644
Ref: 341911008644
Node: Callback example 1 trivial callback11009122
Ref: library/optparse callback-example-1-trivial-callback11009293
Ref: 341a11009293
Ref: library/optparse optparse-callback-example-111009293
Ref: 341b11009293
Node: Callback example 2 check option order11009741
Ref: library/optparse callback-example-2-check-option-order11009933
Ref: 341c11009933
Ref: library/optparse optparse-callback-example-211009933
Ref: 341d11009933
Node: Callback example 3 check option order generalized11010491
Ref: library/optparse callback-example-3-check-option-order-generalized11010692
Ref: 341e11010692
Ref: library/optparse optparse-callback-example-311010692
Ref: 341f11010692
Node: Callback example 4 check arbitrary condition11011465
Ref: library/optparse callback-example-4-check-arbitrary-condition11011663
Ref: 342011011663
Ref: library/optparse optparse-callback-example-411011663
Ref: 342111011663
Node: Callback example 5 fixed arguments11012458
Ref: library/optparse callback-example-5-fixed-arguments11012644
Ref: 342211012644
Ref: library/optparse optparse-callback-example-511012644
Ref: 342311012644
Node: Callback example 6 variable arguments11013718
Ref: library/optparse callback-example-6-variable-arguments11013851
Ref: 342411013851
Ref: library/optparse optparse-callback-example-611013851
Ref: 342511013851
Node: Extending optparse11015956
Ref: library/optparse extending-optparse11016103
Ref: 342611016103
Ref: library/optparse optparse-extending-optparse11016103
Ref: 33d211016103
Node: Adding new types11016440
Ref: library/optparse adding-new-types11016538
Ref: 342711016538
Ref: library/optparse optparse-adding-new-types11016538
Ref: 342811016538
Ref: library/optparse optparse Option TYPES11016834
Ref: 342911016834
Ref: library/optparse optparse Option TYPE_CHECKER11016993
Ref: 342a11016993
Node: Adding new actions11020032
Ref: library/optparse adding-new-actions11020130
Ref: 342b11020130
Ref: library/optparse optparse-adding-new-actions11020130
Ref: 342c11020130
Ref: library/optparse optparse Option ACTIONS11021225
Ref: 342d11021225
Ref: library/optparse optparse Option STORE_ACTIONS11021301
Ref: 342e11021301
Ref: library/optparse optparse Option TYPED_ACTIONS11021392
Ref: 342f11021392
Ref: library/optparse optparse Option ALWAYS_TYPED_ACTIONS11021483
Ref: 343011021483
Node: Exceptions<11>11024788
Ref: library/optparse exceptions11024910
Ref: 343111024910
Ref: library/optparse optparse OptionError11024953
Ref: 33bb11024953
Ref: library/optparse optparse OptionConflictError11025094
Ref: 340c11025094
Ref: library/optparse optparse OptionValueError11025222
Ref: 33bc11025222
Ref: library/optparse optparse BadOptionError11025345
Ref: 343211025345
Ref: library/optparse optparse AmbiguousOptionError11025450
Ref: 343311025450
Node: getpass — Portable password input11025563
Ref: library/getpass doc11025789
Ref: 343411025789
Ref: library/getpass getpass-portable-password-input11025789
Ref: 343511025789
Ref: library/getpass module-getpass11025789
Ref: 6611025789
Ref: library/getpass translation-repo11025789
Ref: 343611025789
Ref: library/getpass getpass getpass11026202
Ref: 21d11026202
Ref: library/getpass getpass GetPassWarning11027859
Ref: 343711027859
Ref: library/getpass getpass getuser11027987
Ref: 65a11027987
Ref: getpass — Portable password input-Footnote-111028699
Ref: getpass — Portable password input-Footnote-211028766
Node: fileinput — Iterate over lines from multiple input streams11028846
Ref: library/fileinput doc11029084
Ref: 343811029084
Ref: library/fileinput fileinput-iterate-over-lines-from-multiple-input-streams11029084
Ref: 343911029084
Ref: library/fileinput module-fileinput11029084
Ref: 5f11029084
Ref: library/fileinput translation-repo11029084
Ref: 343a11029084
Ref: library/fileinput fileinput input11031409
Ref: a0211031409
Ref: library/fileinput fileinput filename11032670
Ref: 343b11032670
Ref: library/fileinput fileinput fileno11032826
Ref: 163511032826
Ref: library/fileinput fileinput lineno11033023
Ref: 343c11033023
Ref: library/fileinput fileinput filelineno11033296
Ref: 343d11033296
Ref: library/fileinput fileinput isfirstline11033562
Ref: 343e11033562
Ref: library/fileinput fileinput isstdin11033714
Ref: 343f11033714
Ref: library/fileinput fileinput nextfile11033857
Ref: 344011033857
Ref: library/fileinput fileinput close11034397
Ref: 344111034397
Ref: library/fileinput fileinput FileInput11034568
Ref: 94111034568
Ref: library/fileinput fileinput hook_compressed11037306
Ref: a0311037306
Ref: library/fileinput fileinput hook_encoded11038112
Ref: ea011038112
Ref: fileinput — Iterate over lines from multiple input streams-Footnote-111038719
Node: curses — Terminal handling for character-cell displays11038788
Ref: library/curses doc11039047
Ref: 344211039047
Ref: library/curses curses-terminal-handling-for-character-cell-displays11039047
Ref: 344311039047
Ref: library/curses module-curses11039047
Ref: 2f11039047
Ref: library/curses translation-repo11039047
Ref: 344411039047
Ref: curses — Terminal handling for character-cell displays-Footnote-111041013
Node: Functions<5>11041076
Ref: library/curses curses-functions11041204
Ref: 344611041204
Ref: library/curses functions11041204
Ref: 344711041204
Ref: library/curses curses error11041306
Ref: 344811041306
Ref: library/curses curses assume_default_colors11041674
Ref: 1f611041674
Ref: library/curses curses baudrate11042297
Ref: 344a11042297
Ref: library/curses curses beep11042649
Ref: 344b11042649
Ref: library/curses curses can_change_color11042715
Ref: 344c11042715
Ref: library/curses curses cbreak11042887
Ref: 344d11042887
Ref: library/curses curses color_content11043363
Ref: 9f411043363
Ref: library/curses curses color_pair11043746
Ref: 344f11043746
Ref: library/curses curses curs_set11044133
Ref: 345311044133
Ref: library/curses curses def_prog_mode11044557
Ref: 345411044557
Ref: library/curses curses def_shell_mode11044881
Ref: 345611044881
Ref: library/curses curses delay_output11045223
Ref: 345811045223
Ref: library/curses curses doupdate11045313
Ref: 345911045313
Ref: library/curses curses echo11046138
Ref: 345d11046138
Ref: library/curses curses endwin11046274
Ref: 345e11046274
Ref: library/curses curses erasechar11046377
Ref: 345f11046377
Ref: library/curses curses filter11046645
Ref: 346011046645
Ref: library/curses curses flash11047256
Ref: 346111047256
Ref: library/curses curses flushinp11047519
Ref: 346211047519
Ref: library/curses curses getmouse11047705
Ref: 346311047705
Ref: library/curses curses getsyx11048711
Ref: 346d11048711
Ref: library/curses curses getwin11048922
Ref: 346f11048922
Ref: library/curses curses has_colors11049177
Ref: 347111049177
Ref: library/curses curses has_extended_color_support11049309
Ref: 9f811049309
Ref: library/curses curses has_ic11049695
Ref: 347211049695
Ref: library/curses curses has_il11049951
Ref: 347311049951
Ref: library/curses curses has_key11050248
Ref: 347411050248
Ref: library/curses curses halfdelay11050402
Ref: 347511050402
Ref: library/curses curses init_color11050840
Ref: 9f511050840
Ref: library/curses curses init_pair11051496
Ref: 9f611051496
Ref: library/curses curses initscr11052295
Ref: 18f711052295
Ref: library/curses curses is_term_resized11052570
Ref: 347711052570
Ref: library/curses curses isendwin11052741
Ref: 347811052741
Ref: library/curses curses keyname11052899
Ref: 347911052899
Ref: library/curses curses killchar11053430
Ref: 347a11053430
Ref: library/curses curses longname11053701
Ref: 347b11053701
Ref: library/curses curses meta11053976
Ref: 347c11053976
Ref: library/curses curses mouseinterval11054133
Ref: 347d11054133
Ref: library/curses curses mousemask11054440
Ref: 347e11054440
Ref: library/curses curses napms11054860
Ref: 18f611054860
Ref: library/curses curses newpad11054928
Ref: 347f11054928
Ref: library/curses curses newwin11056016
Ref: 348011056016
Ref: library/curses curses nl11056383
Ref: 348111056383
Ref: library/curses curses nocbreak11056598
Ref: 347611056598
Ref: library/curses curses noecho11056717
Ref: 348211056717
Ref: library/curses curses nonl11056816
Ref: 348311056816
Ref: library/curses curses noqiflush11057309
Ref: 348411057309
Ref: library/curses curses noraw11057699
Ref: 348511057699
Ref: library/curses curses pair_content11057812
Ref: 9f711057812
Ref: library/curses curses pair_number11058038
Ref: 345211058038
Ref: library/curses curses putp11058230
Ref: 348611058230
Ref: library/curses curses qiflush11058476
Ref: 348711058476
Ref: library/curses curses raw11058742
Ref: 344e11058742
Ref: library/curses curses reset_prog_mode11058984
Ref: 345511058984
Ref: library/curses curses reset_shell_mode11059130
Ref: 345711059130
Ref: library/curses curses resetty11059276
Ref: 348811059276
Ref: library/curses curses resize_term11059418
Ref: 191811059418
Ref: library/curses curses resizeterm11059957
Ref: 191711059957
Ref: library/curses curses savetty11060230
Ref: 348911060230
Ref: library/curses curses get_escdelay11060365
Ref: aee11060365
Ref: library/curses curses set_escdelay11060491
Ref: aef11060491
Ref: library/curses curses get_tabsize11060789
Ref: af011060789
Ref: library/curses curses set_tabsize11060913
Ref: af111060913
Ref: library/curses curses setsyx11061126
Ref: 348a11061126
Ref: library/curses curses setupterm11061296
Ref: 348b11061296
Ref: library/curses curses start_color11061713
Ref: 348c11061713
Ref: library/curses curses termattrs11062406
Ref: 348f11062406
Ref: library/curses curses termname11062636
Ref: 349011062636
Ref: library/curses curses tigetflag11062785
Ref: 349111062785
Ref: library/curses curses tigetnum11063101
Ref: 349211063101
Ref: library/curses curses tigetstr11063417
Ref: 349311063417
Ref: library/curses curses tparm11063725
Ref: 349411063725
Ref: library/curses curses typeahead11064062
Ref: 349511064062
Ref: library/curses curses unctrl11064653
Ref: 349611064653
Ref: library/curses curses ungetch11064934
Ref: 349711064934
Ref: library/curses curses update_lines_cols11065111
Ref: fed11065111
Ref: library/curses curses unget_wch11065304
Ref: 12a011065304
Ref: library/curses curses ungetmouse11065525
Ref: 349811065525
Ref: library/curses curses use_env11065691
Ref: 349911065691
Ref: library/curses curses use_default_colors11066201
Ref: 1f711066201
Ref: library/curses curses wrapper11066302
Ref: c7511066302
Node: Window Objects11067128
Ref: library/curses curses-window-objects11067277
Ref: 197111067277
Ref: library/curses window-objects11067277
Ref: 349a11067277
Ref: library/curses curses window11067326
Ref: 129d11067326
Ref: library/curses curses window addch11067494
Ref: 349b11067494
Ref: library/curses curses window addnstr11068097
Ref: 349c11068097
Ref: library/curses curses window addstr11068356
Ref: 345b11068356
Ref: library/curses curses window attroff11069356
Ref: 349d11069356
Ref: library/curses curses window attron11069499
Ref: 349e11069499
Ref: library/curses curses window attrset11069636
Ref: 349f11069636
Ref: library/curses curses window bkgd11069782
Ref: 34a011069782
Ref: library/curses curses window bkgdset11070227
Ref: 34a111070227
Ref: library/curses curses window border11070793
Ref: 34a211070793
Ref: library/curses curses window box11072801
Ref: 34a911072801
Ref: library/curses curses window chgat11073029
Ref: 34aa11073029
Ref: library/curses curses window clear11073653
Ref: 34ac11073653
Ref: library/curses curses window clearok11073808
Ref: 34ae11073808
Ref: library/curses curses window clrtobot11073953
Ref: 34af11073953
Ref: library/curses curses window clrtoeol11074150
Ref: 34b011074150
Ref: library/curses curses window cursyncup11074230
Ref: 34b111074230
Ref: library/curses curses window delch11074398
Ref: 34b211074398
Ref: library/curses curses window deleteln11074477
Ref: 34b311074477
Ref: library/curses curses window derwin11074601
Ref: 34b411074601
Ref: library/curses curses window echochar11075009
Ref: 34b611075009
Ref: library/curses curses window enclose11075163
Ref: 1c7911075163
Ref: library/curses curses window encoding11075588
Ref: 129e11075588
Ref: library/curses curses window erase11075969
Ref: 34ad11075969
Ref: library/curses curses window getbegyx11076022
Ref: 34b711076022
Ref: library/curses curses window getbkgd11076125
Ref: 34b811076125
Ref: library/curses curses window getch11076240
Ref: 180d11076240
Ref: library/curses curses window get_wch11076560
Ref: 129f11076560
Ref: library/curses curses window getkey11076828
Ref: 34b911076828
Ref: library/curses curses window getmaxyx11077136
Ref: 34ba11077136
Ref: library/curses curses window getparyx11077241
Ref: 34bb11077241
Ref: library/curses curses window getstr11077445
Ref: 182611077445
Ref: library/curses curses window getyx11077797
Ref: 34bc11077797
Ref: library/curses curses window hline11077938
Ref: 34bd11077938
Ref: library/curses curses window idcok11078124
Ref: 34be11078124
Ref: library/curses curses window idlok11078470
Ref: 34bf11078470
Ref: library/curses curses window immedok11078663
Ref: 34c011078663
Ref: library/curses curses window inch11079012
Ref: 34c111079012
Ref: library/curses curses window insch11079200
Ref: 34c211079200
Ref: library/curses curses window insdelln11079414
Ref: 34c311079414
Ref: library/curses curses window insertln11079793
Ref: 34c411079793
Ref: library/curses curses window insnstr11079923
Ref: 34c511079923
Ref: library/curses curses window insstr11080436
Ref: 34c611080436
Ref: library/curses curses window instr11080855
Ref: 182511080855
Ref: library/curses curses window is_linetouched11081391
Ref: 34c711081391
Ref: library/curses curses window is_wintouched11081674
Ref: 34c811081674
Ref: library/curses curses window keypad11081854
Ref: 34c911081854
Ref: library/curses curses window leaveok11082122
Ref: 346e11082122
Ref: library/curses curses window move11082469
Ref: 34ca11082469
Ref: library/curses curses window mvderwin11082552
Ref: 34cb11082552
Ref: library/curses curses window mvwin11082829
Ref: 34cc11082829
Ref: library/curses curses window nodelay11082945
Ref: 34cd11082945
Ref: library/curses curses window notimeout11083054
Ref: 34ce11083054
Ref: library/curses curses window noutrefresh11083318
Ref: 345a11083318
Ref: library/curses curses window overlay11083592
Ref: 34cf11083592
Ref: library/curses curses window overwrite11084241
Ref: 34d011084241
Ref: library/curses curses window putwin11084893
Ref: 347011084893
Ref: library/curses curses window redrawln11085099
Ref: 34d111085099
Ref: library/curses curses window redrawwin11085305
Ref: 34d211085305
Ref: library/curses curses window refresh11085451
Ref: 345c11085451
Ref: library/curses curses window resize11086472
Ref: 34d311086472
Ref: library/curses curses window scroll11086824
Ref: 34d411086824
Ref: library/curses curses window scrollok11086932
Ref: 34d511086932
Ref: library/curses curses window setscrreg11087468
Ref: 34d611087468
Ref: library/curses curses window standend11087637
Ref: 34d711087637
Ref: library/curses curses window standout11087788
Ref: 34d811087788
Ref: library/curses curses window subpad11087858
Ref: 34d911087858
Ref: library/curses curses window subwin11088097
Ref: 34b511088097
Ref: library/curses curses window syncdown11088455
Ref: 34da11088455
Ref: library/curses curses window syncok11088701
Ref: 34db11088701
Ref: library/curses curses window syncup11088864
Ref: 34dc11088864
Ref: library/curses curses window timeout11088990
Ref: 34dd11088990
Ref: library/curses curses window touchline11089493
Ref: 34ab11089493
Ref: library/curses curses window touchwin11089801
Ref: 34de11089801
Ref: library/curses curses window untouchwin11089926
Ref: 34df11089926
Ref: library/curses curses window vline11090059
Ref: 1ae611090059
Ref: Window Objects-Footnote-111090318
Node: Constants<6>11090361
Ref: library/curses constants11090489
Ref: 34e011090489
Ref: library/curses curses ERR11090594
Ref: 34e111090594
Ref: library/curses curses OK11090739
Ref: 34e211090739
Ref: library/curses curses version11090882
Ref: 34e311090882
Ref: library/curses curses ncurses_version11090977
Ref: bdc11090977
Ref: library/curses curses COLORS11091396
Ref: 348d11091396
Ref: library/curses curses COLOR_PAIRS11091552
Ref: 348e11091552
Ref: library/curses curses COLS11091718
Ref: fef11091718
Ref: library/curses curses LINES11091978
Ref: fee11091978
Ref: library/curses curses A_ALTCHARSET11092531
Ref: 34e411092531
Ref: library/curses curses A_BLINK11092635
Ref: 34e511092635
Ref: library/curses curses A_BOLD11092734
Ref: 34e611092734
Ref: library/curses curses A_DIM11092832
Ref: 34e711092832
Ref: library/curses curses A_INVIS11092932
Ref: 34e811092932
Ref: library/curses curses A_ITALIC11093046
Ref: 34e911093046
Ref: library/curses curses A_NORMAL11093147
Ref: 344911093147
Ref: library/curses curses A_PROTECT11093254
Ref: 34ea11093254
Ref: library/curses curses A_REVERSE11093358
Ref: 345111093358
Ref: library/curses curses A_STANDOUT11093500
Ref: 345011093500
Ref: library/curses curses A_UNDERLINE11093574
Ref: 34eb11093574
Ref: library/curses curses A_HORIZONTAL11093649
Ref: 34ec11093649
Ref: library/curses curses A_LEFT11093744
Ref: 34ed11093744
Ref: library/curses curses A_LOW11093847
Ref: 34ee11093847
Ref: library/curses curses A_RIGHT11093952
Ref: 34ef11093952
Ref: library/curses curses A_TOP11094055
Ref: 34f011094055
Ref: library/curses curses A_VERTICAL11094145
Ref: 34f111094145
Ref: library/curses curses A_ATTRIBUTES11094535
Ref: 34f211094535
Ref: library/curses curses A_CHARTEXT11094646
Ref: 34f311094646
Ref: library/curses curses A_COLOR11094767
Ref: 34f411094767
Ref: library/curses curses KEY_MIN11095215
Ref: 34f511095215
Ref: library/curses curses KEY_BREAK11095327
Ref: 34f611095327
Ref: library/curses curses KEY_DOWN11095441
Ref: 34f711095441
Ref: library/curses curses KEY_UP11095542
Ref: 34f811095542
Ref: library/curses curses KEY_LEFT11095645
Ref: 34f911095645
Ref: library/curses curses KEY_RIGHT11095749
Ref: 34fa11095749
Ref: library/curses curses KEY_HOME11095852
Ref: 34fb11095852
Ref: library/curses curses KEY_BACKSPACE11095957
Ref: 34fc11095957
Ref: library/curses curses KEY_F011096056
Ref: 34fd11096056
Ref: library/curses curses KEY_Fn11096232
Ref: 34fe11096232
Ref: library/curses curses KEY_DL11096350
Ref: 34ff11096350
Ref: library/curses curses KEY_IL11096454
Ref: 350011096454
Ref: library/curses curses KEY_DC11096558
Ref: 350111096558
Ref: library/curses curses KEY_IC11096667
Ref: 350211096667
Ref: library/curses curses KEY_EIC11096793
Ref: 350311096793
Ref: library/curses curses KEY_CLEAR11096909
Ref: 350411096909
Ref: library/curses curses KEY_EOS11097012
Ref: 350511097012
Ref: library/curses curses KEY_EOL11097127
Ref: 350611097127
Ref: library/curses curses KEY_SF11097239
Ref: 350711097239
Ref: library/curses curses KEY_SR11097353
Ref: 350811097353
Ref: library/curses curses KEY_NPAGE11097481
Ref: 350911097481
Ref: library/curses curses KEY_PPAGE11097583
Ref: 350a11097583
Ref: library/curses curses KEY_STAB11097688
Ref: 350b11097688
Ref: library/curses curses KEY_CTAB11097788
Ref: 350c11097788
Ref: library/curses curses KEY_CATAB11097891
Ref: 350d11097891
Ref: library/curses curses KEY_ENTER11097998
Ref: 350e11097998
Ref: library/curses curses KEY_SRESET11098118
Ref: 350f11098118
Ref: library/curses curses KEY_RESET11098243
Ref: 351011098243
Ref: library/curses curses KEY_PRINT11098368
Ref: 351111098368
Ref: library/curses curses KEY_LL11098463
Ref: 351211098463
Ref: library/curses curses KEY_A111098588
Ref: 351311098588
Ref: library/curses curses KEY_A311098701
Ref: 351411098701
Ref: library/curses curses KEY_B211098815
Ref: 351511098815
Ref: library/curses curses KEY_C111098924
Ref: 351611098924
Ref: library/curses curses KEY_C311099037
Ref: 351711099037
Ref: library/curses curses KEY_BTAB11099153
Ref: 351811099153
Ref: library/curses curses KEY_BEG11099253
Ref: 351911099253
Ref: library/curses curses KEY_CANCEL11099364
Ref: 351a11099364
Ref: library/curses curses KEY_CLOSE11099462
Ref: 351b11099462
Ref: library/curses curses KEY_COMMAND11099543
Ref: 351c11099543
Ref: library/curses curses KEY_COPY11099635
Ref: 351d11099635
Ref: library/curses curses KEY_CREATE11099734
Ref: 351e11099734
Ref: library/curses curses KEY_END11099830
Ref: 351f11099830
Ref: library/curses curses KEY_EXIT11099927
Ref: 352011099927
Ref: library/curses curses KEY_FIND11100024
Ref: 352111100024
Ref: library/curses curses KEY_HELP11100121
Ref: 352211100121
Ref: library/curses curses KEY_MARK11100218
Ref: 352311100218
Ref: library/curses curses KEY_MESSAGE11100299
Ref: 352411100299
Ref: library/curses curses KEY_MOVE11100385
Ref: 352511100385
Ref: library/curses curses KEY_NEXT11100482
Ref: 352611100482
Ref: library/curses curses KEY_OPEN11100579
Ref: 352711100579
Ref: library/curses curses KEY_OPTIONS11100660
Ref: 352811100660
Ref: library/curses curses KEY_PREVIOUS11100730
Ref: 352911100730
Ref: library/curses curses KEY_REDO11100824
Ref: 352a11100824
Ref: library/curses curses KEY_REFERENCE11100905
Ref: 352b11100905
Ref: library/curses curses KEY_REFRESH11100983
Ref: 352c11100983
Ref: library/curses curses KEY_REPLACE11101053
Ref: 352d11101053
Ref: library/curses curses KEY_RESTART11101123
Ref: 352e11101123
Ref: library/curses curses KEY_RESUME11101211
Ref: 352f11101211
Ref: library/curses curses KEY_SAVE11101308
Ref: 353011101308
Ref: library/curses curses KEY_SBEG11101405
Ref: 353111101405
Ref: library/curses curses KEY_SCANCEL11101505
Ref: 353211101505
Ref: library/curses curses KEY_SCOMMAND11101582
Ref: 353311101582
Ref: library/curses curses KEY_SCOPY11101677
Ref: 353411101677
Ref: library/curses curses KEY_SCREATE11101765
Ref: 353511101765
Ref: library/curses curses KEY_SDC11101857
Ref: 353611101857
Ref: library/curses curses KEY_SDL11101969
Ref: 353711101969
Ref: library/curses curses KEY_SELECT11102084
Ref: 353811102084
Ref: library/curses curses KEY_SEND11102181
Ref: 353911102181
Ref: library/curses curses KEY_SEOL11102285
Ref: 353a11102285
Ref: library/curses curses KEY_SEXIT11102397
Ref: 353b11102397
Ref: library/curses curses KEY_SFIND11102502
Ref: 353c11102502
Ref: library/curses curses KEY_SHELP11102607
Ref: 353d11102607
Ref: library/curses curses KEY_SHOME11102712
Ref: 353e11102712
Ref: library/curses curses KEY_SIC11102815
Ref: 353f11102815
Ref: library/curses curses KEY_SLEFT11102923
Ref: 354011102923
Ref: library/curses curses KEY_SMESSAGE11103017
Ref: 354111103017
Ref: library/curses curses KEY_SMOVE11103112
Ref: 354211103112
Ref: library/curses curses KEY_SNEXT11103217
Ref: 354311103217
Ref: library/curses curses KEY_SOPTIONS11103305
Ref: 354411103305
Ref: library/curses curses KEY_SPREVIOUS11103383
Ref: 354511103383
Ref: library/curses curses KEY_SPRINT11103476
Ref: 354611103476
Ref: library/curses curses KEY_SREDO11103581
Ref: 354711103581
Ref: library/curses curses KEY_SREPLACE11103669
Ref: 354811103669
Ref: library/curses curses KEY_SRIGHT11103765
Ref: 354911103765
Ref: library/curses curses KEY_SRSUME11103877
Ref: 354a11103877
Ref: library/curses curses KEY_SSAVE11103983
Ref: 354b11103983
Ref: library/curses curses KEY_SSUSPEND11104071
Ref: 354c11104071
Ref: library/curses curses KEY_SUNDO11104166
Ref: 354d11104166
Ref: library/curses curses KEY_SUSPEND11104254
Ref: 354e11104254
Ref: library/curses curses KEY_UNDO11104340
Ref: 354f11104340
Ref: library/curses curses KEY_MOUSE11104438
Ref: 346411104438
Ref: library/curses curses KEY_RESIZE11104556
Ref: 355011104556
Ref: library/curses curses KEY_MAX11104667
Ref: 355111104667
Ref: library/curses curses-acs-codes11105870
Ref: 355211105870
Ref: library/curses curses ACS_BBSS11106447
Ref: 355311106447
Ref: library/curses curses ACS_BLOCK11106575
Ref: 355411106575
Ref: library/curses curses ACS_BOARD11106683
Ref: 355511106683
Ref: library/curses curses ACS_BSBS11106788
Ref: 355611106788
Ref: library/curses curses ACS_BSSB11106912
Ref: 355711106912
Ref: library/curses curses ACS_BSSS11107038
Ref: 355811107038
Ref: library/curses curses ACS_BTEE11107154
Ref: 355911107154
Ref: library/curses curses ACS_BULLET11107238
Ref: 355a11107238
Ref: library/curses curses ACS_CKBOARD11107305
Ref: 355b11107305
Ref: library/curses curses ACS_DARROW11107389
Ref: 355c11107389
Ref: library/curses curses ACS_DEGREE11107469
Ref: 355d11107469
Ref: library/curses curses ACS_DIAMOND11107543
Ref: 355e11107543
Ref: library/curses curses ACS_GEQUAL11107611
Ref: 355f11107611
Ref: library/curses curses ACS_HLINE11107713
Ref: 34a411107713
Ref: library/curses curses ACS_LANTERN11107801
Ref: 356011107801
Ref: library/curses curses ACS_LARROW11107876
Ref: 356111107876
Ref: library/curses curses ACS_LEQUAL11107947
Ref: 356211107947
Ref: library/curses curses ACS_LLCORNER11108029
Ref: 34a711108029
Ref: library/curses curses ACS_LRCORNER11108112
Ref: 34a811108112
Ref: library/curses curses ACS_LTEE11108212
Ref: 356311108212
Ref: library/curses curses ACS_NEQUAL11108294
Ref: 356411108294
Ref: library/curses curses ACS_PI11108383
Ref: 356511108383
Ref: library/curses curses ACS_PLMINUS11108468
Ref: 356611108468
Ref: library/curses curses ACS_PLUS11108563
Ref: 356711108563
Ref: library/curses curses ACS_RARROW11108650
Ref: 356811108650
Ref: library/curses curses ACS_RTEE11108738
Ref: 356911108738
Ref: library/curses curses ACS_S111108835
Ref: 356a11108835
Ref: library/curses curses ACS_S311108936
Ref: 356b11108936
Ref: library/curses curses ACS_S711109037
Ref: 356c11109037
Ref: library/curses curses ACS_S911109138
Ref: 356d11109138
Ref: library/curses curses ACS_SBBS11109241
Ref: 356e11109241
Ref: library/curses curses ACS_SBSB11109368
Ref: 356f11109368
Ref: library/curses curses ACS_SBSS11109490
Ref: 357011109490
Ref: library/curses curses ACS_SSBB11109608
Ref: 357111109608
Ref: library/curses curses ACS_SSBS11109734
Ref: 357211109734
Ref: library/curses curses ACS_SSSB11109853
Ref: 357311109853
Ref: library/curses curses ACS_SSSS11109970
Ref: 357411109970
Ref: library/curses curses ACS_STERLING11110084
Ref: 357511110084
Ref: library/curses curses ACS_TTEE11110175
Ref: 357611110175
Ref: library/curses curses ACS_UARROW11110256
Ref: 357711110256
Ref: library/curses curses ACS_ULCORNER11110325
Ref: 34a511110325
Ref: library/curses curses ACS_URCORNER11110403
Ref: 34a611110403
Ref: library/curses curses ACS_VLINE11110499
Ref: 34a311110499
Ref: library/curses curses BUTTONn_PRESSED11110879
Ref: 346511110879
Ref: library/curses curses BUTTONn_RELEASED11111024
Ref: 346611111024
Ref: library/curses curses BUTTONn_CLICKED11111168
Ref: 346711111168
Ref: library/curses curses BUTTONn_DOUBLE_CLICKED11111289
Ref: 346811111289
Ref: library/curses curses BUTTONn_TRIPLE_CLICKED11111401
Ref: 346911111401
Ref: library/curses curses BUTTON_SHIFT11111533
Ref: 346a11111533
Ref: library/curses curses BUTTON_CTRL11111693
Ref: 346b11111693
Ref: library/curses curses BUTTON_ALT11111855
Ref: 346c11111855
Ref: library/curses curses COLOR_BLACK11112305
Ref: 357811112305
Ref: library/curses curses COLOR_BLUE11112391
Ref: 357911112391
Ref: library/curses curses COLOR_CYAN11112488
Ref: 357a11112488
Ref: library/curses curses COLOR_GREEN11112589
Ref: 357b11112589
Ref: library/curses curses COLOR_MAGENTA11112657
Ref: 357c11112657
Ref: library/curses curses COLOR_RED11112759
Ref: 357d11112759
Ref: library/curses curses COLOR_WHITE11112838
Ref: 357e11112838
Ref: library/curses curses COLOR_YELLOW11112906
Ref: 357f11112906
Node: curses textpad — Text input widget for curses programs11112966
Ref: library/curses curses-textpad-text-input-widget-for-curses-programs11113212
Ref: 358011113212
Ref: library/curses module-curses textpad11113212
Ref: 3211113212
Ref: library/curses curses textpad rectangle11113800
Ref: 358211113800
Node: Textbox objects11114523
Ref: library/curses curses-textpad-objects11114631
Ref: 358311114631
Ref: library/curses textbox-objects11114631
Ref: 358411114631
Ref: library/curses curses textpad Textbox11114745
Ref: 358111114745
Ref: library/curses curses textpad Textbox edit11115225
Ref: 358611115225
Ref: library/curses curses textpad Textbox do_command11115796
Ref: 358711115796
Ref: library/curses curses textpad Textbox gather11119526
Ref: 358811119526
Ref: library/curses curses textpad Textbox stripspaces11119719
Ref: 358511119719
Node: curses ascii — Utilities for ASCII characters11120130
Ref: library/curses ascii doc11120371
Ref: 358911120371
Ref: library/curses ascii curses-ascii-utilities-for-ascii-characters11120371
Ref: 358a11120371
Ref: library/curses ascii module-curses ascii11120371
Ref: 3011120371
Ref: library/curses ascii translation-repo11120371
Ref: 358b11120371
Ref: library/curses ascii curses ascii NUL11120965
Ref: 358c11120965
Ref: library/curses ascii curses ascii SOH11121003
Ref: 358d11121003
Ref: library/curses ascii curses ascii STX11121087
Ref: 358e11121087
Ref: library/curses ascii curses ascii ETX11121149
Ref: 358f11121149
Ref: library/curses ascii curses ascii EOT11121209
Ref: 359011121209
Ref: library/curses ascii curses ascii ENQ11121277
Ref: 359111121277
Ref: library/curses ascii curses ascii ACK11121374
Ref: 359211121374
Ref: library/curses ascii curses ascii BEL11121438
Ref: 359311121438
Ref: library/curses ascii curses ascii BS11121491
Ref: 359411121491
Ref: library/curses ascii curses ascii TAB11121548
Ref: 359511121548
Ref: library/curses ascii curses ascii HT11121600
Ref: 359611121600
Ref: library/curses ascii curses ascii LF11121694
Ref: 359711121694
Ref: library/curses ascii curses ascii NL11121751
Ref: 359811121751
Ref: library/curses ascii curses ascii VT11121838
Ref: 359911121838
Ref: library/curses ascii curses ascii FF11121898
Ref: 359a11121898
Ref: library/curses ascii curses ascii CR11121955
Ref: 359b11121955
Ref: library/curses ascii curses ascii SO11122018
Ref: 359c11122018
Ref: library/curses ascii curses ascii SI11122106
Ref: 359d11122106
Ref: library/curses ascii curses ascii DLE11122192
Ref: 359e11122192
Ref: library/curses ascii curses ascii DC111122257
Ref: 359f11122257
Ref: library/curses ascii curses ascii DC211122327
Ref: 35a011122327
Ref: library/curses ascii curses ascii DC311122417
Ref: 35a111122417
Ref: library/curses ascii curses ascii DC411122488
Ref: 35a211122488
Ref: library/curses ascii curses ascii NAK11122553
Ref: 35a311122553
Ref: library/curses ascii curses ascii SYN11122626
Ref: 35a411122626
Ref: library/curses ascii curses ascii ETB11122691
Ref: 35a511122691
Ref: library/curses ascii curses ascii CAN11122762
Ref: 35a611122762
Ref: library/curses ascii curses ascii EM11122817
Ref: 35a711122817
Ref: library/curses ascii curses ascii SUB11122878
Ref: 35a811122878
Ref: library/curses ascii curses ascii ESC11122937
Ref: 35a911122937
Ref: library/curses ascii curses ascii FS11122992
Ref: 35aa11122992
Ref: library/curses ascii curses ascii GS11123054
Ref: 35ab11123054
Ref: library/curses ascii curses ascii RS11123117
Ref: 35ac11123117
Ref: library/curses ascii curses ascii US11123204
Ref: 35ad11123204
Ref: library/curses ascii curses ascii SP11123266
Ref: 35ae11123266
Ref: library/curses ascii curses ascii DEL11123319
Ref: 35af11123319
Ref: library/curses ascii curses ascii isalnum11123617
Ref: 35b011123617
Ref: library/curses ascii curses ascii isalpha11123764
Ref: 35b111123764
Ref: library/curses ascii curses ascii isascii11123909
Ref: 35b211123909
Ref: library/curses ascii curses ascii isblank11124018
Ref: 35b311124018
Ref: library/curses ascii curses ascii iscntrl11124131
Ref: 35b411124131
Ref: library/curses ascii curses ascii isdigit11124257
Ref: 35b511124257
Ref: library/curses ascii curses ascii isgraph11124421
Ref: 35b611124421
Ref: library/curses ascii curses ascii islower11124522
Ref: 35b711124522
Ref: library/curses ascii curses ascii isprint11124610
Ref: 35b811124610
Ref: library/curses ascii curses ascii ispunct11124714
Ref: 35b911124714
Ref: library/curses ascii curses ascii isspace11124857
Ref: 35ba11124857
Ref: library/curses ascii curses ascii isupper11125025
Ref: 35bb11125025
Ref: library/curses ascii curses ascii isxdigit11125109
Ref: 35bc11125109
Ref: library/curses ascii curses ascii isctrl11125252
Ref: 35bd11125252
Ref: library/curses ascii curses ascii ismeta11125361
Ref: 35be11125361
Ref: library/curses ascii curses ascii ascii11125961
Ref: 35bf11125961
Ref: library/curses ascii curses ascii ctrl11126068
Ref: 35c011126068
Ref: library/curses ascii curses ascii alt11126236
Ref: 35c111126236
Ref: library/curses ascii curses ascii unctrl11126508
Ref: 35c211126508
Ref: library/curses ascii curses ascii controlnames11127063
Ref: 35c311127063
Ref: curses ascii — Utilities for ASCII characters-Footnote-111127345
Node: curses panel — A panel stack extension for curses11127417
Ref: library/curses panel doc11127656
Ref: 35c411127656
Ref: library/curses panel curses-panel-a-panel-stack-extension-for-curses11127656
Ref: 35c511127656
Ref: library/curses panel module-curses panel11127656
Ref: 3111127656
Ref: library/curses panel translation-repo11127656
Ref: 35c611127656
Node: Functions<6>11128132
Ref: library/curses panel cursespanel-functions11128254
Ref: 35c711128254
Ref: library/curses panel functions11128254
Ref: 35c811128254
Ref: library/curses panel curses panel bottom_panel11128362
Ref: 35c911128362
Ref: library/curses panel curses panel new_panel11128457
Ref: 35ca11128457
Ref: library/curses panel curses panel top_panel11128759
Ref: 35cb11128759
Ref: library/curses panel curses panel update_panels11128848
Ref: 35cc11128848
Node: Panel Objects11129059
Ref: library/curses panel curses-panel-objects11129181
Ref: 35cd11129181
Ref: library/curses panel panel-objects11129181
Ref: 35ce11129181
Ref: library/curses panel curses panel Panel above11129535
Ref: 35cf11129535
Ref: library/curses panel curses panel Panel below11129612
Ref: 35d011129612
Ref: library/curses panel curses panel Panel bottom11129689
Ref: 35d111129689
Ref: library/curses panel curses panel Panel hidden11129767
Ref: 35d211129767
Ref: library/curses panel curses panel Panel hide11129887
Ref: 35d311129887
Ref: library/curses panel curses panel Panel move11130021
Ref: 35d411130021
Ref: library/curses panel curses panel Panel replace11130113
Ref: 35d511130113
Ref: library/curses panel curses panel Panel set_userptr11130217
Ref: 35d611130217
Ref: library/curses panel curses panel Panel show11130411
Ref: 35d711130411
Ref: library/curses panel curses panel Panel top11130494
Ref: 35d811130494
Ref: library/curses panel curses panel Panel userptr11130562
Ref: 35d911130562
Ref: library/curses panel curses panel Panel window11130677
Ref: 35da11130677
Node: cmd — Support for line-oriented command interpreters11130765
Ref: library/cmd doc11130948
Ref: 35db11130948
Ref: library/cmd cmd-support-for-line-oriented-command-interpreters11130948
Ref: 35dc11130948
Ref: library/cmd module-cmd11130948
Ref: 1a11130948
Ref: library/cmd translation-repo11130948
Ref: 35dd11130948
Ref: library/cmd cmd Cmd11131424
Ref: 183611131424
Ref: cmd — Support for line-oriented command interpreters-Footnote-111133097
Node: Cmd Objects11133160
Ref: library/cmd cmd-objects11133282
Ref: 35df11133282
Ref: library/cmd id111133282
Ref: 35e011133282
Ref: library/cmd cmd Cmd cmdloop11133381
Ref: 35e111133381
Ref: library/cmd cmd Cmd do_help11135472
Ref: 1a1311135472
Ref: library/cmd cmd Cmd onecmd11136005
Ref: 35e411136005
Ref: library/cmd cmd Cmd emptyline11136596
Ref: 35e711136596
Ref: library/cmd cmd Cmd default11136794
Ref: 35e611136794
Ref: library/cmd cmd Cmd completedefault11136991
Ref: 35e811136991
Ref: library/cmd cmd Cmd columnize11137213
Ref: 1bf111137213
Ref: library/cmd cmd Cmd precmd11137449
Ref: 35e511137449
Ref: library/cmd cmd Cmd postcmd11137928
Ref: 35e311137928
Ref: library/cmd cmd Cmd preloop11138561
Ref: 35e911138561
Ref: library/cmd cmd Cmd postloop11138755
Ref: 35ea11138755
Ref: library/cmd cmd Cmd prompt11139039
Ref: 35eb11139039
Ref: library/cmd cmd Cmd identchars11139108
Ref: 35ec11139108
Ref: library/cmd cmd Cmd lastcmd11139203
Ref: 35ed11139203
Ref: library/cmd cmd Cmd cmdqueue11139276
Ref: 35ee11139276
Ref: library/cmd cmd Cmd intro11139527
Ref: 35e211139527
Ref: library/cmd cmd Cmd doc_header11139681
Ref: 35ef11139681
Ref: library/cmd cmd Cmd misc_header11139801
Ref: 35f011139801
Ref: library/cmd cmd Cmd undoc_header11140020
Ref: 35f111140020
Ref: library/cmd cmd Cmd ruler11140236
Ref: 35f211140236
Ref: library/cmd cmd Cmd use_rawinput11140410
Ref: 35de11140410
Node: Cmd Example11140886
Ref: library/cmd cmd-example11141008
Ref: 35f311141008
Ref: library/cmd id211141008
Ref: 35f411141008
Node: Concurrent Execution11146358
Ref: library/concurrency doc11146533
Ref: 35f611146533
Ref: library/concurrency concurrency11146533
Ref: 35f711146533
Ref: library/concurrency concurrent-execution11146533
Ref: 35f811146533
Ref: library/concurrency translation-repo11146533
Ref: 35f911146533
Node: threading — Thread-based parallelism11147630
Ref: library/threading doc11147779
Ref: 35fa11147779
Ref: library/threading module-threading11147779
Ref: f311147779
Ref: library/threading threading-thread-based-parallelism11147779
Ref: 35fb11147779
Ref: threading — Thread-based parallelism-Footnote-111148526
Node: Introduction<7>11148595
Ref: library/threading introduction11148728
Ref: 35fc11148728
Ref: Introduction<7>-Footnote-111151633
Node: GIL and performance considerations11151690
Ref: library/threading gil-and-performance-considerations11151844
Ref: 35fd11151844
Ref: GIL and performance considerations-Footnote-111152635
Node: Reference<2>11152677
Ref: library/threading reference11152875
Ref: 35fe11152875
Ref: library/threading threading active_count11152960
Ref: 35f11152960
Ref: library/threading threading current_thread11153251
Ref: 35e11153251
Ref: library/threading threading excepthook11153648
Ref: a4d11153648
Ref: library/threading threading __excepthook__11154988
Ref: a4c11154988
Ref: library/threading threading get_ident11155260
Ref: 136211155260
Ref: library/threading threading get_native_id11155656
Ref: c3411155656
Ref: library/threading threading enumerate11156215
Ref: 1c4211156215
Ref: library/threading threading main_thread11156599
Ref: 11d411156599
Ref: library/threading threading settrace11156826
Ref: a4a11156826
Ref: library/threading threading settrace_all_threads11157082
Ref: 6f011157082
Ref: library/threading threading gettrace11157436
Ref: a4811157436
Ref: library/threading threading setprofile11157564
Ref: a4b11157564
Ref: library/threading threading setprofile_all_threads11157827
Ref: 6f111157827
Ref: library/threading threading getprofile11158188
Ref: a4911158188
Ref: library/threading threading stack_size11158323
Ref: 35ff11158323
Ref: library/threading threading TIMEOUT_MAX11159649
Ref: 360011159649
Node: Thread-local data11160869
Ref: library/threading thread-local-data11160958
Ref: 360111160958
Ref: library/threading threading local11164072
Ref: 184711164072
Node: Thread objects11164150
Ref: library/threading id111164260
Ref: 360211164260
Ref: library/threading thread-objects11164260
Ref: 360311164260
Ref: library/threading threading Thread11166929
Ref: 17611166929
Ref: library/threading threading Thread start11169141
Ref: 17811169141
Ref: library/threading threading Thread run11169807
Ref: c3311169807
Ref: library/threading meth-thread-join11170619
Ref: 360411170619
Ref: library/threading threading Thread join11170619
Ref: 13ec11170619
Ref: library/threading threading Thread name11172182
Ref: 2a011172182
Ref: library/threading threading Thread getName11172937
Ref: 360611172937
Ref: library/threading threading Thread setName11172965
Ref: 35d11172965
Ref: library/threading threading Thread ident11173147
Ref: 311c11173147
Ref: library/threading threading Thread native_id11173539
Ref: c3511173539
Ref: library/threading threading Thread is_alive11174352
Ref: b4811174352
Ref: library/threading threading Thread daemon11174690
Ref: 35c11174690
Ref: library/threading threading Thread isDaemon11175283
Ref: 360711175283
Ref: library/threading threading Thread setDaemon11175312
Ref: 35b11175312
Node: Lock objects11175498
Ref: library/threading id211175604
Ref: 360811175604
Ref: library/threading lock-objects11175604
Ref: 360911175604
Ref: library/threading threading Lock11177017
Ref: 19dc11177017
Ref: library/threading threading Lock acquire11177426
Ref: 8a811177426
Ref: library/threading threading Lock release11178887
Ref: 14ca11178887
Ref: library/threading threading Lock locked11179372
Ref: 360b11179372
Node: RLock objects11179454
Ref: library/threading id311179563
Ref: 360c11179563
Ref: library/threading rlock-objects11179563
Ref: 360d11179563
Ref: library/threading threading RLock11180934
Ref: 32e11180934
Ref: library/threading threading RLock acquire11181457
Ref: 107d11181457
Ref: library/threading threading RLock release11183453
Ref: 360e11183453
Ref: library/threading threading RLock locked11184150
Ref: 182411184150
Node: Condition objects11184302
Ref: library/threading condition-objects11184416
Ref: 360f11184416
Ref: library/threading id411184416
Ref: 361011184416
Ref: library/threading threading Condition11187535
Ref: 135d11187535
Ref: library/threading threading Condition acquire11188089
Ref: 361111188089
Ref: library/threading threading Condition release11188301
Ref: 361211188301
Ref: library/threading threading Condition locked11188484
Ref: 361411188484
Ref: library/threading threading Condition wait11188636
Ref: 1c4e11188636
Ref: library/threading threading Condition wait_for11190171
Ref: 361311190171
Ref: library/threading threading Condition notify11191145
Ref: 1b4e11191145
Ref: library/threading threading Condition notify_all11192047
Ref: 35911192047
Node: Semaphore objects11192463
Ref: library/threading id511192581
Ref: 361511192581
Ref: library/threading semaphore-objects11192581
Ref: 361611192581
Ref: library/threading threading Semaphore11193280
Ref: 135e11193280
Ref: library/threading threading Semaphore acquire11193982
Ref: 145b11193982
Ref: library/threading threading Semaphore release11195282
Ref: 361711195282
Ref: library/threading threading BoundedSemaphore11195664
Ref: 135f11195664
Node: Semaphore example11196206
Ref: library/threading semaphore-example11196320
Ref: 361811196320
Ref: library/threading semaphore-examples11196320
Ref: 361911196320
Node: Event objects11197191
Ref: library/threading event-objects11197301
Ref: 361a11197301
Ref: library/threading id611197301
Ref: 361b11197301
Ref: library/threading threading Event11197705
Ref: 136011197705
Ref: library/threading threading Event is_set11198112
Ref: 35a11198112
Ref: library/threading threading Event set11198284
Ref: 361c11198284
Ref: library/threading threading Event clear11198512
Ref: 361d11198512
Ref: library/threading threading Event wait11198741
Ref: 152e11198741
Node: Timer objects11199476
Ref: library/threading id711199584
Ref: 361e11199584
Ref: library/threading timer-objects11199584
Ref: 361f11199584
Ref: library/threading threading Timer11200347
Ref: 136111200347
Ref: library/threading threading Timer cancel11200807
Ref: 362011200807
Node: Barrier objects11200997
Ref: library/threading barrier-objects11201083
Ref: 362111201083
Ref: library/threading threading Barrier11202040
Ref: 13eb11202040
Ref: library/threading threading Barrier wait11202385
Ref: 362211202385
Ref: library/threading threading Barrier reset11203533
Ref: 362311203533
Ref: library/threading threading Barrier abort11203970
Ref: 362411203970
Ref: library/threading threading Barrier parties11204460
Ref: 362511204460
Ref: library/threading threading Barrier n_waiting11204552
Ref: 362611204552
Ref: library/threading threading Barrier broken11204650
Ref: 362711204650
Ref: library/threading threading BrokenBarrierError11204767
Ref: 13ed11204767
Node: Using locks conditions and semaphores in the with statement11204945
Ref: library/threading using-locks-conditions-and-semaphores-in-the-with-statement11205100
Ref: 362811205100
Ref: library/threading with-locks11205100
Ref: 360a11205100
Node: multiprocessing — Process-based parallelism11205941
Ref: library/multiprocessing doc11206181
Ref: 362911206181
Ref: library/multiprocessing module-multiprocessing11206181
Ref: 9811206181
Ref: library/multiprocessing multiprocessing-process-based-parallelism11206181
Ref: 362a11206181
Ref: library/multiprocessing translation-repo11206181
Ref: 362b11206181
Ref: multiprocessing — Process-based parallelism-Footnote-111206722
Node: Introduction<8>11206795
Ref: library/multiprocessing introduction11206913
Ref: 362c11206913
Node: The Process class11208993
Ref: library/multiprocessing the-process-class11209097
Ref: 362d11209097
Node: Contexts and start methods11210571
Ref: library/multiprocessing contexts-and-start-methods11210720
Ref: 362f11210720
Ref: library/multiprocessing multiprocessing-start-methods11210720
Ref: 1d511210720
Ref: library/multiprocessing multiprocessing-start-method-spawn11210915
Ref: 1d811210915
Ref: library/multiprocessing multiprocessing-start-method-fork11211477
Ref: 1d711211477
Ref: library/multiprocessing multiprocessing-start-method-forkserver11212503
Ref: 1d411212503
Ref: Contexts and start methods-Footnote-111216681
Ref: Contexts and start methods-Footnote-211216746
Node: Exchanging objects between processes11216801
Ref: library/multiprocessing exchanging-objects-between-processes11216966
Ref: 363111216966
Node: Synchronization between processes11218863
Ref: library/multiprocessing synchronization-between-processes11219033
Ref: 363311219033
Node: Sharing state between processes11219753
Ref: library/multiprocessing sharing-state-between-processes11219910
Ref: 363411219910
Node: Using a pool of workers11223164
Ref: library/multiprocessing using-a-pool-of-workers11223279
Ref: 363c11223279
Node: Reference<3>11226571
Ref: library/multiprocessing reference11226720
Ref: 363d11226720
Node: Global start method11227250
Ref: library/multiprocessing global-start-method11227349
Ref: 363e11227349
Ref: library/multiprocessing id111227349
Ref: 363f11227349
Node: Process and exceptions11227968
Ref: library/multiprocessing process-and-exceptions11228092
Ref: 364011228092
Ref: library/multiprocessing multiprocessing Process11228167
Ref: 25211228167
Ref: library/multiprocessing multiprocessing Process run11231321
Ref: 363011231321
Ref: library/multiprocessing multiprocessing Process start11232130
Ref: 159911232130
Ref: library/multiprocessing multiprocessing Process join11232379
Ref: 159b11232379
Ref: library/multiprocessing multiprocessing Process name11233101
Ref: 364111233101
Ref: library/multiprocessing multiprocessing Process is_alive11233566
Ref: 159a11233566
Ref: library/multiprocessing multiprocessing Process daemon11233802
Ref: 364211233802
Ref: library/multiprocessing multiprocessing Process pid11234683
Ref: 364511234683
Ref: library/multiprocessing multiprocessing Process exitcode11234808
Ref: 364411234808
Ref: library/multiprocessing multiprocessing Process authkey11235409
Ref: 364611235409
Ref: library/multiprocessing multiprocessing Process sentinel11235937
Ref: 12e911235937
Ref: library/multiprocessing multiprocessing Process interrupt11236576
Ref: 25111236576
Ref: library/multiprocessing multiprocessing Process terminate11237492
Ref: 183f11237492
Ref: library/multiprocessing multiprocessing Process kill11238308
Ref: d5111238308
Ref: library/multiprocessing multiprocessing Process close11238466
Ref: d5011238466
Ref: library/multiprocessing multiprocessing ProcessError11239761
Ref: 364811239761
Ref: library/multiprocessing multiprocessing BufferTooShort11239873
Ref: 364911239873
Ref: library/multiprocessing multiprocessing AuthenticationError11240182
Ref: 364a11240182
Ref: library/multiprocessing multiprocessing TimeoutError11240286
Ref: 364b11240286
Ref: Process and exceptions-Footnote-111240432
Node: Pipes and Queues11240488
Ref: library/multiprocessing pipes-and-queues11240609
Ref: 364c11240609
Ref: library/multiprocessing multiprocessing Pipe11244334
Ref: 363211244334
Ref: library/multiprocessing multiprocessing Queue11244884
Ref: 1b7111244884
Ref: library/multiprocessing multiprocessing Queue qsize11245609
Ref: 365711245609
Ref: library/multiprocessing multiprocessing Queue empty11245951
Ref: 195011245951
Ref: library/multiprocessing multiprocessing Queue full11246238
Ref: 365811246238
Ref: library/multiprocessing multiprocessing Queue put11246433
Ref: 1e0511246433
Ref: library/multiprocessing multiprocessing Queue put_nowait11247265
Ref: 365911247265
Ref: library/multiprocessing multiprocessing Queue get11247348
Ref: 1e0611247348
Ref: library/multiprocessing multiprocessing Queue get_nowait11248141
Ref: 365411248141
Ref: library/multiprocessing multiprocessing Queue close11248388
Ref: 1b7211248388
Ref: library/multiprocessing multiprocessing Queue join_thread11248847
Ref: 365a11248847
Ref: library/multiprocessing multiprocessing Queue cancel_join_thread11249398
Ref: 365511249398
Ref: library/multiprocessing multiprocessing SimpleQueue11250546
Ref: b1211250546
Ref: library/multiprocessing multiprocessing SimpleQueue close11250808
Ref: b1311250808
Ref: library/multiprocessing multiprocessing SimpleQueue empty11251119
Ref: 195111251119
Ref: library/multiprocessing multiprocessing SimpleQueue get11251309
Ref: 365b11251309
Ref: library/multiprocessing multiprocessing SimpleQueue put11251387
Ref: 365c11251387
Ref: library/multiprocessing multiprocessing JoinableQueue11251454
Ref: 364d11251454
Ref: library/multiprocessing multiprocessing JoinableQueue task_done11251800
Ref: 365011251800
Ref: library/multiprocessing multiprocessing JoinableQueue join11252488
Ref: 365d11252488
Ref: Pipes and Queues-Footnote-111252992
Node: Miscellaneous<4>11253056
Ref: library/multiprocessing miscellaneous11253173
Ref: 365e11253173
Ref: library/multiprocessing multiprocessing active_children11253222
Ref: 365f11253222
Ref: library/multiprocessing multiprocessing cpu_count11253437
Ref: 117111253437
Ref: library/multiprocessing multiprocessing current_process11254188
Ref: 366011254188
Ref: library/multiprocessing multiprocessing parent_process11254385
Ref: 366111254385
Ref: library/multiprocessing multiprocessing freeze_support11254654
Ref: 182311254654
Ref: library/multiprocessing multiprocessing get_all_start_methods11255648
Ref: 116b11255648
Ref: library/multiprocessing multiprocessing get_context11256003
Ref: 24a11256003
Ref: library/multiprocessing multiprocessing get_start_method11256650
Ref: 116c11256650
Ref: library/multiprocessing multiprocessing set_executable11257392
Ref: 1b7811257392
Ref: library/multiprocessing multiprocessing set_forkserver_preload11257951
Ref: 18f011257951
Ref: library/multiprocessing multiprocessing set_start_method11258662
Ref: 24b11258662
Ref: Miscellaneous<4>-Footnote-111259766
Node: Connection Objects11259831
Ref: library/multiprocessing connection-objects11259958
Ref: 366211259958
Ref: library/multiprocessing multiprocessing connection Connection11260277
Ref: 12e811260277
Ref: library/multiprocessing multiprocessing connection Connection send11260328
Ref: 366411260328
Ref: library/multiprocessing multiprocessing connection Connection recv11260655
Ref: 366511260655
Ref: library/multiprocessing multiprocessing connection Connection fileno11260948
Ref: 366611260948
Ref: library/multiprocessing multiprocessing connection Connection close11261048
Ref: 366711261048
Ref: library/multiprocessing multiprocessing connection Connection poll11261200
Ref: 366811261200
Ref: library/multiprocessing multiprocessing connection Connection send_bytes11261687
Ref: 366911261687
Ref: library/multiprocessing multiprocessing connection Connection recv_bytes11262146
Ref: 366a11262146
Ref: library/multiprocessing multiprocessing connection Connection recv_bytes_into11262793
Ref: 366b11262793
Ref: library/multiprocessing multiprocessing-recv-pickle-security11264618
Ref: 366c11264618
Node: Synchronization primitives11265319
Ref: library/multiprocessing synchronization-primitives11265451
Ref: 366d11265451
Ref: library/multiprocessing multiprocessing Barrier11265821
Ref: 363b11265821
Ref: library/multiprocessing multiprocessing BoundedSemaphore11266108
Ref: 363911266108
Ref: library/multiprocessing multiprocessing BoundedSemaphore locked11266566
Ref: 366f11266566
Ref: library/multiprocessing multiprocessing Condition11266885
Ref: 363a11266885
Ref: library/multiprocessing multiprocessing Event11267351
Ref: 1bee11267351
Ref: library/multiprocessing multiprocessing Lock11267557
Ref: 183b11267557
Ref: library/multiprocessing multiprocessing Lock acquire11268526
Ref: 366e11268526
Ref: library/multiprocessing multiprocessing Lock release11270052
Ref: 367011270052
Ref: library/multiprocessing multiprocessing Lock locked11270421
Ref: 185f11270421
Ref: library/multiprocessing multiprocessing RLock11270573
Ref: 183c11270573
Ref: library/multiprocessing multiprocessing RLock acquire11271430
Ref: 367111271430
Ref: library/multiprocessing multiprocessing RLock release11273081
Ref: 367211273081
Ref: library/multiprocessing multiprocessing RLock locked11274058
Ref: 186011274058
Ref: library/multiprocessing multiprocessing Semaphore11274210
Ref: 363811274210
Ref: library/multiprocessing multiprocessing Semaphore get_value11274646
Ref: 367311274646
Ref: library/multiprocessing multiprocessing Semaphore locked11274886
Ref: 367411274886
Ref: Synchronization primitives-Footnote-111275592
Node: Shared ctypes Objects11275656
Ref: library/multiprocessing shared-ctypes-objects11275778
Ref: 367511275778
Ref: library/multiprocessing multiprocessing Value11275955
Ref: 363511275955
Ref: library/multiprocessing multiprocessing Array11277382
Ref: 363611277382
Node: The multiprocessing sharedctypes module11278982
Ref: library/multiprocessing module-multiprocessing sharedctypes11279079
Ref: 9e11279079
Ref: library/multiprocessing the-multiprocessing-sharedctypes-module11279079
Ref: 367611279079
Ref: library/multiprocessing multiprocessing sharedctypes RawArray11279710
Ref: 367711279710
Ref: library/multiprocessing multiprocessing sharedctypes RawValue11280539
Ref: 367911280539
Ref: library/multiprocessing multiprocessing sharedctypes Array11281323
Ref: 367811281323
Ref: library/multiprocessing multiprocessing sharedctypes Value11282311
Ref: 367a11282311
Ref: library/multiprocessing multiprocessing sharedctypes copy11283283
Ref: 367b11283283
Ref: library/multiprocessing multiprocessing sharedctypes synchronized11283445
Ref: 103311283445
Node: Managers11286690
Ref: library/multiprocessing managers11286799
Ref: 367c11286799
Ref: library/multiprocessing multiprocessing-managers11286799
Ref: 365111286799
Ref: library/multiprocessing multiprocessing Manager11287149
Ref: 25011287149
Ref: library/multiprocessing module-multiprocessing managers11287470
Ref: 9b11287470
Ref: library/multiprocessing multiprocessing managers BaseManager11287659
Ref: 367d11287659
Ref: library/multiprocessing multiprocessing managers BaseManager start11289193
Ref: 367e11289193
Ref: library/multiprocessing multiprocessing managers BaseManager get_server11289428
Ref: 368011289428
Ref: library/multiprocessing multiprocessing managers BaseManager connect11289972
Ref: 368211289972
Ref: library/multiprocessing multiprocessing managers BaseManager shutdown11290253
Ref: 367f11290253
Ref: library/multiprocessing multiprocessing managers BaseManager register11290489
Ref: 368311290489
Ref: library/multiprocessing multiprocessing managers BaseManager address11292798
Ref: 368111292798
Ref: library/multiprocessing multiprocessing managers SyncManager11293339
Ref: 187c11293339
Ref: library/multiprocessing multiprocessing managers SyncManager Barrier11293780
Ref: 368611293780
Ref: library/multiprocessing multiprocessing managers SyncManager BoundedSemaphore11293972
Ref: 368711293972
Ref: library/multiprocessing multiprocessing managers SyncManager Condition11294128
Ref: 368811294128
Ref: library/multiprocessing multiprocessing managers SyncManager Event11294507
Ref: 368911294507
Ref: library/multiprocessing multiprocessing managers SyncManager Lock11294634
Ref: 159f11294634
Ref: library/multiprocessing multiprocessing managers SyncManager Namespace11294759
Ref: 368a11294759
Ref: library/multiprocessing multiprocessing managers SyncManager Queue11294884
Ref: 31aa11294884
Ref: library/multiprocessing multiprocessing managers SyncManager RLock11295016
Ref: 15a011295016
Ref: library/multiprocessing multiprocessing managers SyncManager Semaphore11295142
Ref: 15a111295142
Ref: library/multiprocessing multiprocessing managers SyncManager Array11295284
Ref: 368b11295284
Ref: library/multiprocessing multiprocessing managers SyncManager Value11295383
Ref: 368c11295383
Ref: library/multiprocessing multiprocessing managers SyncManager dict11295528
Ref: 368d11295528
Ref: library/multiprocessing multiprocessing managers SyncManager list11295709
Ref: 368e11295709
Ref: library/multiprocessing multiprocessing managers SyncManager set11295857
Ref: 24f11295857
Ref: library/multiprocessing multiprocessing managers Namespace11296367
Ref: 363711296367
Node: Customized managers11297208
Ref: library/multiprocessing customized-managers11297303
Ref: 368f11297303
Node: Using a remote manager11298075
Ref: library/multiprocessing using-a-remote-manager11298170
Ref: 369011298170
Node: Proxy Objects11300311
Ref: library/multiprocessing multiprocessing-proxy-objects11300412
Ref: 24c11300412
Ref: library/multiprocessing proxy-objects11300412
Ref: 369111300412
Ref: library/multiprocessing multiprocessing managers BaseProxy11303696
Ref: 368411303696
Ref: library/multiprocessing multiprocessing managers BaseProxy _callmethod11303818
Ref: 368511303818
Ref: library/multiprocessing multiprocessing managers BaseProxy _getvalue11305399
Ref: 369211305399
Ref: library/multiprocessing multiprocessing managers BaseProxy __repr__11305559
Ref: 369311305559
Ref: library/multiprocessing multiprocessing managers BaseProxy __str__11305645
Ref: 369411305645
Node: Cleanup<2>11305761
Ref: library/multiprocessing cleanup11305821
Ref: 369511305821
Node: Process Pools11306110
Ref: library/multiprocessing module-multiprocessing pool11306224
Ref: 9c11306224
Ref: library/multiprocessing process-pools11306224
Ref: 369611306224
Ref: library/multiprocessing multiprocessing pool Pool11306386
Ref: 116d11306386
Ref: library/multiprocessing multiprocessing pool Pool apply11309422
Ref: 159d11309422
Ref: library/multiprocessing multiprocessing pool Pool apply_async11309793
Ref: 159e11309793
Ref: library/multiprocessing multiprocessing pool Pool map11310645
Ref: 12ed11310645
Ref: library/multiprocessing multiprocessing pool Pool map_async11311430
Ref: 12ee11311430
Ref: library/multiprocessing multiprocessing pool Pool imap11312285
Ref: 369a11312285
Ref: library/multiprocessing multiprocessing pool Pool imap_unordered11312997
Ref: 369b11312997
Ref: library/multiprocessing multiprocessing pool Pool starmap11313321
Ref: 12ea11313321
Ref: library/multiprocessing multiprocessing pool Pool starmap_async11313676
Ref: 12eb11313676
Ref: library/multiprocessing multiprocessing pool Pool close11314031
Ref: 369711314031
Ref: library/multiprocessing multiprocessing pool Pool terminate11314218
Ref: 369811314218
Ref: library/multiprocessing multiprocessing pool Pool join11314452
Ref: 369c11314452
Ref: library/multiprocessing multiprocessing pool AsyncResult11314910
Ref: 369911314910
Ref: library/multiprocessing multiprocessing pool AsyncResult get11315069
Ref: 369d11315069
Ref: library/multiprocessing multiprocessing pool AsyncResult wait11315434
Ref: 369e11315434
Ref: library/multiprocessing multiprocessing pool AsyncResult ready11315558
Ref: 369f11315558
Ref: library/multiprocessing multiprocessing pool AsyncResult successful11315635
Ref: 36a011315635
Node: Listeners and Clients11316933
Ref: library/multiprocessing listeners-and-clients11317053
Ref: 36a111317053
Ref: library/multiprocessing module-multiprocessing connection11317053
Ref: 9911317053
Ref: library/multiprocessing multiprocessing-listeners-clients11317053
Ref: 366311317053
Ref: library/multiprocessing multiprocessing connection deliver_challenge11317589
Ref: 36a211317589
Ref: library/multiprocessing multiprocessing connection answer_challenge11317995
Ref: 36a311317995
Ref: library/multiprocessing multiprocessing connection Client11318309
Ref: 36a411318309
Ref: library/multiprocessing multiprocessing connection Listener11319073
Ref: 1a0b11319073
Ref: library/multiprocessing multiprocessing connection Listener accept11320845
Ref: 19c711320845
Ref: library/multiprocessing multiprocessing connection Listener close11321127
Ref: 36a611321127
Ref: library/multiprocessing multiprocessing connection Listener address11321427
Ref: 36a711321427
Ref: library/multiprocessing multiprocessing connection Listener last_accepted11321523
Ref: 36a811321523
Ref: library/multiprocessing multiprocessing connection wait11321954
Ref: 12e711321954
Node: Address Formats11325983
Ref: library/multiprocessing address-formats11326056
Ref: 36a911326056
Ref: library/multiprocessing multiprocessing-address-formats11326056
Ref: 36a511326056
Node: Authentication keys11326770
Ref: library/multiprocessing authentication-keys11326887
Ref: 36aa11326887
Ref: library/multiprocessing multiprocessing-auth-keys11326887
Ref: 364711326887
Node: Logging<2>11328071
Ref: library/multiprocessing logging11328199
Ref: 36ab11328199
Ref: library/multiprocessing multiprocessing get_logger11328467
Ref: 320511328467
Ref: library/multiprocessing multiprocessing log_to_stderr11328986
Ref: 36ac11328986
Node: The multiprocessing dummy module11330093
Ref: library/multiprocessing module-multiprocessing dummy11330193
Ref: 9a11330193
Ref: library/multiprocessing the-multiprocessing-dummy-module11330193
Ref: 36ad11330193
Ref: library/multiprocessing multiprocessing pool ThreadPool11330718
Ref: 1cbc11330718
Node: Programming guidelines11332481
Ref: library/multiprocessing multiprocessing-programming11332627
Ref: 362e11332627
Ref: library/multiprocessing programming-guidelines11332627
Ref: 36ae11332627
Node: All start methods11332875
Ref: library/multiprocessing all-start-methods11332998
Ref: 36af11332998
Ref: library/multiprocessing multiprocessing-programming-spawn11339052
Ref: 364311339052
Ref: All start methods-Footnote-111339089
Ref: All start methods-Footnote-211339153
Ref: All start methods-Footnote-311339217
Node: The spawn and forkserver start methods11339281
Ref: library/multiprocessing multiprocessing-programming-forkserver11339404
Ref: 1d911339404
Ref: library/multiprocessing the-spawn-and-forkserver-start-methods11339404
Ref: 36b011339404
Ref: library/multiprocessing multiprocessing-safe-main-import11340210
Ref: 36b111340210
Node: Examples<15>11341483
Ref: library/multiprocessing examples11341608
Ref: 36b211341608
Ref: library/multiprocessing multiprocessing-examples11341608
Ref: 365611341608
Node: multiprocessing shared_memory — Shared memory for direct access across processes11350520
Ref: library/multiprocessing shared_memory doc11350744
Ref: 36b311350744
Ref: library/multiprocessing shared_memory module-multiprocessing shared_memory11350744
Ref: 9d11350744
Ref: library/multiprocessing shared_memory multiprocessing-shared-memory-shared-memory-for-direct-access-across-processes11350744
Ref: 36b411350744
Ref: library/multiprocessing shared_memory translation-repo11350744
Ref: 36b511350744
Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory11352298
Ref: 19c011352298
Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory close11355611
Ref: 36b711355611
Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory unlink11356088
Ref: 36b811356088
Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory buf11356708
Ref: 36b911356708
Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory name11356797
Ref: 36ba11356797
Ref: library/multiprocessing shared_memory multiprocessing shared_memory SharedMemory size11356908
Ref: 36bb11356908
Ref: library/multiprocessing shared_memory multiprocessing managers SharedMemoryManager11359998
Ref: 36b611359998
Ref: library/multiprocessing shared_memory multiprocessing managers SharedMemoryManager SharedMemory11361401
Ref: 36bc11361401
Ref: library/multiprocessing shared_memory multiprocessing managers SharedMemoryManager ShareableList11361553
Ref: 36bd11361553
Ref: library/multiprocessing shared_memory multiprocessing shared_memory ShareableList11363410
Ref: 1d4011363410
Ref: library/multiprocessing shared_memory multiprocessing shared_memory ShareableList count11365907
Ref: 36be11365907
Ref: library/multiprocessing shared_memory multiprocessing shared_memory ShareableList index11365995
Ref: 36bf11365995
Ref: library/multiprocessing shared_memory multiprocessing shared_memory ShareableList format11366145
Ref: 36c011366145
Ref: library/multiprocessing shared_memory multiprocessing shared_memory ShareableList shm11366299
Ref: 36c111366299
Ref: multiprocessing shared_memory — Shared memory for direct access across processes-Footnote-111368891
Ref: multiprocessing shared_memory — Shared memory for direct access across processes-Footnote-211368981
Ref: multiprocessing shared_memory — Shared memory for direct access across processes-Footnote-311369008
Node: The concurrent package11369064
Ref: library/concurrent doc11369290
Ref: 36c211369290
Ref: library/concurrent the-concurrent-package11369290
Ref: 36c311369290
Ref: library/concurrent translation-repo11369290
Ref: 36c411369290
Node: concurrent futures — Launching parallel tasks11369562
Ref: library/concurrent futures doc11369775
Ref: 36c511369775
Ref: library/concurrent futures concurrent-futures-launching-parallel-tasks11369775
Ref: 36c611369775
Ref: library/concurrent futures module-concurrent futures11369775
Ref: 2411369775
Ref: library/concurrent futures translation-repo11369775
Ref: 36c711369775
Ref: concurrent futures — Launching parallel tasks-Footnote-111371152
Ref: concurrent futures — Launching parallel tasks-Footnote-211371238
Ref: concurrent futures — Launching parallel tasks-Footnote-311371325
Node: Executor Objects11371416
Ref: library/concurrent futures executor-objects11371543
Ref: 36ca11371543
Ref: library/concurrent futures concurrent futures Executor11371596
Ref: 36c811371596
Ref: library/concurrent futures concurrent futures Executor submit11371796
Ref: c7711371796
Ref: library/concurrent futures concurrent futures Executor map11372206
Ref: 1dc11372206
Ref: library/concurrent futures concurrent futures Executor shutdown11374112
Ref: aec11374112
Node: ThreadPoolExecutor11376280
Ref: library/concurrent futures threadpoolexecutor11376439
Ref: 36cb11376439
Ref: library/concurrent futures concurrent futures ThreadPoolExecutor11377509
Ref: 94a11377509
Node: ThreadPoolExecutor Example11379915
Ref: library/concurrent futures id111379996
Ref: 36cd11379996
Ref: library/concurrent futures threadpoolexecutor-example11379996
Ref: 13bb11379996
Node: InterpreterPoolExecutor11381204
Ref: library/concurrent futures interpreterpoolexecutor11381366
Ref: 36ce11381366
Ref: library/concurrent futures concurrent futures InterpreterPoolExecutor11384088
Ref: 1d211384088
Ref: InterpreterPoolExecutor-Footnote-111386086
Node: ProcessPoolExecutor11386128
Ref: library/concurrent futures processpoolexecutor11386286
Ref: 36d011386286
Ref: library/concurrent futures concurrent futures ProcessPoolExecutor11387311
Ref: 1d611387311
Ref: library/concurrent futures concurrent futures ProcessPoolExecutor terminate_workers11391052
Ref: 1da11391052
Ref: library/concurrent futures concurrent futures ProcessPoolExecutor kill_workers11391538
Ref: 1db11391538
Ref: ProcessPoolExecutor-Footnote-111392087
Node: ProcessPoolExecutor Example11392143
Ref: library/concurrent futures id211392226
Ref: 36d211392226
Ref: library/concurrent futures processpoolexecutor-example11392226
Ref: 13bc11392226
Node: Future Objects11393132
Ref: library/concurrent futures future-objects11393283
Ref: 36d311393283
Ref: library/concurrent futures concurrent futures Future11393494
Ref: 13ba11393494
Ref: library/concurrent futures concurrent futures Future cancel11393735
Ref: 36d411393735
Ref: library/concurrent futures concurrent futures Future cancelled11394034
Ref: 36d511394034
Ref: library/concurrent futures concurrent futures Future running11394134
Ref: 36d611394134
Ref: library/concurrent futures concurrent futures Future done11394267
Ref: 36d711394267
Ref: library/concurrent futures concurrent futures Future result11394392
Ref: 36d811394392
Ref: library/concurrent futures concurrent futures Future exception11395049
Ref: 36d911395049
Ref: library/concurrent futures concurrent futures Future add_done_callback11395689
Ref: 36da11395689
Ref: library/concurrent futures concurrent futures Future set_running_or_notify_cancel11396527
Ref: 36db11396527
Ref: library/concurrent futures concurrent futures Future set_result11397514
Ref: 36dc11397514
Ref: library/concurrent futures concurrent futures Future set_exception11397937
Ref: 36dd11397937
Node: Module Functions11398395
Ref: library/concurrent futures module-functions11398544
Ref: 36de11398544
Ref: library/concurrent futures concurrent futures wait11398597
Ref: 1bed11398597
Ref: library/concurrent futures concurrent futures FIRST_COMPLETED11399918
Ref: 36df11399918
Ref: library/concurrent futures concurrent futures FIRST_EXCEPTION11400227
Ref: 36e011400227
Ref: library/concurrent futures concurrent futures ALL_COMPLETED11400748
Ref: 36e111400748
Ref: library/concurrent futures concurrent futures as_completed11400950
Ref: 19af11400950
Ref: Module Functions-Footnote-111401988
Node: Exception classes11402030
Ref: library/concurrent futures exception-classes11402156
Ref: 36e211402156
Ref: library/concurrent futures concurrent futures CancelledError11402211
Ref: bd011402211
Ref: library/concurrent futures concurrent futures TimeoutError11402302
Ref: 36e311402302
Ref: library/concurrent futures concurrent futures BrokenExecutor11402564
Ref: 36e411402564
Ref: library/concurrent futures concurrent futures InvalidStateError11402822
Ref: 193911402822
Ref: library/concurrent futures concurrent futures thread BrokenThreadPool11403006
Ref: 36cc11403006
Ref: library/concurrent futures concurrent futures interpreter BrokenInterpreterPool11403266
Ref: 36e511403266
Ref: library/concurrent futures concurrent futures process BrokenProcessPool11403544
Ref: 36d111403544
Node: concurrent interpreters — Multiple interpreters in the same process11403912
Ref: library/concurrent interpreters doc11404139
Ref: 36e611404139
Ref: library/concurrent interpreters concurrent-interpreters-multiple-interpreters-in-the-same-process11404139
Ref: 36e711404139
Ref: library/concurrent interpreters module-concurrent interpreters11404139
Ref: 2511404139
Ref: library/concurrent interpreters translation-repo11404139
Ref: 36e811404139
Ref: library/concurrent interpreters interp-concurrency11405057
Ref: 36e911405057
Ref: concurrent interpreters — Multiple interpreters in the same process-Footnote-111405637
Ref: concurrent interpreters — Multiple interpreters in the same process-Footnote-211405718
Ref: concurrent interpreters — Multiple interpreters in the same process-Footnote-311405760
Ref: concurrent interpreters — Multiple interpreters in the same process-Footnote-411405802
Node: Key details11405844
Ref: library/concurrent interpreters key-details11405985
Ref: 36ea11405985
Ref: library/concurrent interpreters interp-isolation11406169
Ref: 36eb11406169
Node: Introduction<9>11406278
Ref: library/concurrent interpreters interpreters-intro11406440
Ref: 36ec11406440
Ref: library/concurrent interpreters introduction11406440
Ref: 36ed11406440
Node: Multiple Interpreters and Isolation11407300
Ref: library/concurrent interpreters multiple-interpreters-and-isolation11407421
Ref: 36ee11407421
Node: Running in an Interpreter11408397
Ref: library/concurrent interpreters running-in-an-interpreter11408554
Ref: 36ef11408554
Ref: library/concurrent interpreters interp-call-in-thread11409058
Ref: 36f011409058
Node: Concurrency and Parallelism11409510
Ref: library/concurrent interpreters concurrency-and-parallelism11409666
Ref: 36f111409666
Node: Communication Between Interpreters11411245
Ref: library/concurrent interpreters communication-between-interpreters11411395
Ref: 36f211411395
Node: «Sharing» Objects11411856
Ref: library/concurrent interpreters interp-object-sharing11411970
Ref: 36f411411970
Ref: library/concurrent interpreters sharing-objects11411970
Ref: 36f511411970
Node: Reference<4>11413003
Ref: library/concurrent interpreters reference11413165
Ref: 36f711413165
Ref: library/concurrent interpreters concurrent interpreters list_all11413250
Ref: 36f811413250
Ref: library/concurrent interpreters concurrent interpreters get_current11413410
Ref: 36fa11413410
Ref: library/concurrent interpreters concurrent interpreters get_main11413556
Ref: 36fb11413556
Ref: library/concurrent interpreters concurrent interpreters create11413838
Ref: 17a411413838
Ref: library/concurrent interpreters concurrent interpreters create_queue11413994
Ref: 36f311413994
Node: Interpreter objects11414251
Ref: library/concurrent interpreters interpreter-objects11414342
Ref: 36fc11414342
Ref: library/concurrent interpreters concurrent interpreters Interpreter11414401
Ref: 36f911414401
Ref: library/concurrent interpreters concurrent interpreters Interpreter id11414663
Ref: 36fd11414663
Ref: library/concurrent interpreters concurrent interpreters Interpreter whence11414756
Ref: 36fe11414756
Ref: library/concurrent interpreters concurrent interpreters Interpreter is_running11414871
Ref: 36ff11414871
Ref: library/concurrent interpreters concurrent interpreters Interpreter close11415045
Ref: 17b911415045
Ref: library/concurrent interpreters concurrent interpreters Interpreter prepare_main11415121
Ref: 370011415121
Ref: library/concurrent interpreters concurrent interpreters Interpreter exec11415419
Ref: 370111415419
Ref: library/concurrent interpreters concurrent interpreters Interpreter call11415556
Ref: 370211415556
Ref: library/concurrent interpreters concurrent interpreters Interpreter call_in_thread11415731
Ref: 370311415731
Node: Exceptions<12>11415867
Ref: library/concurrent interpreters exceptions11416001
Ref: 370411416001
Ref: library/concurrent interpreters concurrent interpreters InterpreterError11416044
Ref: 370511416044
Ref: library/concurrent interpreters concurrent interpreters InterpreterNotFoundError11416217
Ref: 370611416217
Ref: library/concurrent interpreters concurrent interpreters ExecutionFailed11416411
Ref: 36cf11416411
Ref: library/concurrent interpreters concurrent interpreters ExecutionFailed excinfo11416600
Ref: 370711416600
Ref: library/concurrent interpreters concurrent interpreters NotShareableError11416717
Ref: 370811416717
Node: Communicating Between Interpreters11416902
Ref: library/concurrent interpreters communicating-between-interpreters11417008
Ref: 370911417008
Ref: library/concurrent interpreters concurrent interpreters Queue11417099
Ref: 36f611417099
Ref: library/concurrent interpreters concurrent interpreters Queue id11417515
Ref: 370a11417515
Ref: library/concurrent interpreters concurrent interpreters QueueEmptyError11417591
Ref: 370b11417591
Ref: library/concurrent interpreters concurrent interpreters QueueFullError11417805
Ref: 370c11417805
Node: Basic usage11418011
Ref: library/concurrent interpreters basic-usage11418149
Ref: 370d11418149
Node: subprocess — Subprocess management11418804
Ref: library/subprocess doc11419009
Ref: 370e11419009
Ref: library/subprocess module-subprocess11419009
Ref: dc11419009
Ref: library/subprocess subprocess-subprocess-management11419009
Ref: 370f11419009
Ref: library/subprocess translation-repo11419009
Ref: 371011419009
Ref: subprocess — Subprocess management-Footnote-111420124
Ref: subprocess — Subprocess management-Footnote-211420194
Node: Using the subprocess Module11420236
Ref: library/subprocess using-the-subprocess-module11420368
Ref: 371111420368
Ref: library/subprocess subprocess run11420671
Ref: d8111420671
Ref: library/subprocess subprocess CompletedProcess11425266
Ref: 107511425266
Ref: library/subprocess subprocess CompletedProcess args11425400
Ref: 371411425400
Ref: library/subprocess subprocess CompletedProcess returncode11425522
Ref: 371511425522
Ref: library/subprocess subprocess CompletedProcess stdout11425796
Ref: 371611425796
Ref: library/subprocess subprocess CompletedProcess stderr11426227
Ref: 371711426227
Ref: library/subprocess subprocess CompletedProcess check_returncode11426469
Ref: 371811426469
Ref: library/subprocess subprocess DEVNULL11426636
Ref: 135611426636
Ref: library/subprocess subprocess PIPE11426882
Ref: d8211426882
Ref: library/subprocess subprocess STDOUT11427146
Ref: 371311427146
Ref: library/subprocess subprocess SubprocessError11427353
Ref: 371911427353
Ref: library/subprocess subprocess TimeoutExpired11427484
Ref: 179311427484
Ref: library/subprocess subprocess TimeoutExpired cmd11427643
Ref: 371a11427643
Ref: library/subprocess subprocess TimeoutExpired timeout11427729
Ref: 371b11427729
Ref: library/subprocess subprocess TimeoutExpired output11427789
Ref: 371c11427789
Ref: library/subprocess subprocess TimeoutExpired stdout11428173
Ref: 371d11428173
Ref: library/subprocess subprocess TimeoutExpired stderr11428268
Ref: 371e11428268
Ref: library/subprocess subprocess CalledProcessError11428740
Ref: 152c11428740
Ref: library/subprocess subprocess CalledProcessError returncode11429003
Ref: 372011429003
Ref: library/subprocess subprocess CalledProcessError cmd11429171
Ref: 372111429171
Ref: library/subprocess subprocess CalledProcessError output11429257
Ref: 372211429257
Ref: library/subprocess subprocess CalledProcessError stdout11429429
Ref: 372311429429
Ref: library/subprocess subprocess CalledProcessError stderr11429524
Ref: 372411429524
Node: Frequently Used Arguments11429838
Ref: library/subprocess frequently-used-arguments11429953
Ref: 371211429953
Ref: library/subprocess id111429953
Ref: 372511429953
Node: Popen Constructor11434143
Ref: library/subprocess popen-constructor11434281
Ref: 372a11434281
Ref: library/subprocess subprocess Popen11434576
Ref: 4b811434576
Ref: Popen Constructor-Footnote-111452340
Node: Exceptions<13>11452400
Ref: library/subprocess exceptions11452504
Ref: 373b11452504
Node: Security Considerations11453763
Ref: library/subprocess security-considerations11453917
Ref: 372911453917
Ref: library/subprocess subprocess-security11453917
Ref: 373c11453917
Ref: Security Considerations-Footnote-111455033
Ref: Security Considerations-Footnote-211455103
Node: Popen Objects11455159
Ref: library/subprocess popen-objects11455307
Ref: 373e11455307
Ref: library/subprocess subprocess Popen poll11455424
Ref: 373f11455424
Ref: library/subprocess subprocess Popen wait11455583
Ref: ee211455583
Ref: library/subprocess subprocess Popen communicate11456594
Ref: 179211456594
Ref: library/subprocess subprocess Popen send_signal11458764
Ref: 15e511458764
Ref: library/subprocess subprocess Popen terminate11459149
Ref: 15e311459149
Ref: library/subprocess subprocess Popen kill11459368
Ref: 15e411459368
Ref: library/subprocess subprocess Popen args11459674
Ref: 374011459674
Ref: library/subprocess subprocess Popen stdin11459859
Ref: 372611459859
Ref: library/subprocess subprocess Popen stdout11460300
Ref: 372711460300
Ref: library/subprocess subprocess Popen stderr11460813
Ref: 372811460813
Ref: library/subprocess subprocess Popen pid11461593
Ref: 374111461593
Ref: library/subprocess subprocess Popen returncode11461775
Ref: c8511461775
Node: Windows Popen Helpers11462274
Ref: library/subprocess windows-popen-helpers11462419
Ref: 374211462419
Ref: library/subprocess subprocess STARTUPINFO11462573
Ref: 372e11462573
Ref: library/subprocess subprocess STARTUPINFO dwFlags11463003
Ref: 374311463003
Ref: library/subprocess subprocess STARTUPINFO hStdInput11463317
Ref: 374411463317
Ref: library/subprocess subprocess STARTUPINFO hStdOutput11463639
Ref: 374611463639
Ref: library/subprocess subprocess STARTUPINFO hStdError11463950
Ref: 374711463950
Ref: library/subprocess subprocess STARTUPINFO wShowWindow11464258
Ref: 374811464258
Ref: library/subprocess subprocess STARTUPINFO lpAttributeList11464750
Ref: e0a11464750
Ref: Windows Popen Helpers-Footnote-111466032
Ref: Windows Popen Helpers-Footnote-211466104
Ref: Windows Popen Helpers-Footnote-311466176
Node: Windows Constants11466265
Ref: library/subprocess windows-constants11466340
Ref: 374b11466340
Ref: library/subprocess subprocess STD_INPUT_HANDLE11466462
Ref: 374c11466462
Ref: library/subprocess subprocess STD_OUTPUT_HANDLE11466599
Ref: 374d11466599
Ref: library/subprocess subprocess STD_ERROR_HANDLE11466747
Ref: 374e11466747
Ref: library/subprocess subprocess SW_HIDE11466893
Ref: 374a11466893
Ref: library/subprocess subprocess STARTF_USESTDHANDLES11466982
Ref: 374511466982
Ref: library/subprocess subprocess STARTF_USESHOWWINDOW11467213
Ref: 374911467213
Ref: library/subprocess subprocess STARTF_FORCEONFEEDBACK11467366
Ref: 374f11467366
Ref: library/subprocess subprocess STARTF_FORCEOFFFEEDBACK11467660
Ref: 375011467660
Ref: library/subprocess subprocess CREATE_NEW_CONSOLE11467870
Ref: 372f11467870
Ref: library/subprocess subprocess CREATE_NEW_PROCESS_GROUP11468017
Ref: 373011468017
Ref: library/subprocess subprocess ABOVE_NORMAL_PRIORITY_CLASS11468340
Ref: 373111468340
Ref: library/subprocess subprocess BELOW_NORMAL_PRIORITY_CLASS11468546
Ref: 373211468546
Ref: library/subprocess subprocess HIGH_PRIORITY_CLASS11468751
Ref: 373311468751
Ref: library/subprocess subprocess IDLE_PRIORITY_CLASS11468939
Ref: 373411468939
Ref: library/subprocess subprocess NORMAL_PRIORITY_CLASS11469137
Ref: 373511469137
Ref: library/subprocess subprocess REALTIME_PRIORITY_CLASS11469340
Ref: 373611469340
Ref: library/subprocess subprocess CREATE_NO_WINDOW11469874
Ref: 373711469874
Ref: library/subprocess subprocess DETACHED_PROCESS11470058
Ref: 373811470058
Ref: library/subprocess subprocess CREATE_DEFAULT_ERROR_MODE11470314
Ref: 373911470314
Ref: library/subprocess subprocess CREATE_BREAKAWAY_FROM_JOB11470716
Ref: 373a11470716
Node: Older high-level API11470915
Ref: library/subprocess call-function-trio11471099
Ref: 375111471099
Ref: library/subprocess older-high-level-api11471099
Ref: 375211471099
Ref: library/subprocess subprocess call11471347
Ref: d8311471347
Ref: library/subprocess subprocess check_call11472744
Ref: 371f11472744
Ref: library/subprocess subprocess check_output11474422
Ref: 11c411474422
Node: Replacing Older Functions with the subprocess Module11477006
Ref: library/subprocess replacing-older-functions-with-the-subprocess-module11477202
Ref: 375311477202
Ref: library/subprocess subprocess-replacements11477202
Ref: 139011477202
Node: Replacing /bin/sh shell command substitution11478272
Ref: library/subprocess replacing-bin-sh-shell-command-substitution11478438
Ref: 375411478438
Node: Replacing shell pipeline11478643
Ref: library/subprocess replacing-shell-pipeline11478837
Ref: 375511478837
Node: Replacing os system11479488
Ref: library/subprocess replacing-os-system11479667
Ref: 375611479667
Node: Replacing the os spawn family11480615
Ref: library/subprocess replacing-the-os-spawn-family11480788
Ref: 375711480788
Node: Replacing os popen11481419
Ref: library/subprocess replacing-os-popen11481564
Ref: 375811481564
Node: Legacy Shell Invocation Functions11481974
Ref: library/subprocess legacy-shell-invocation-functions11482158
Ref: 375911482158
Ref: library/subprocess subprocess getstatusoutput11482522
Ref: 11c611482522
Ref: library/subprocess subprocess getoutput11483854
Ref: 11c511483854
Node: Notes<2>11484423
Ref: library/subprocess notes11484546
Ref: 375a11484546
Node: Timeout Behavior11484729
Ref: library/subprocess subprocess-timeout-behavior11484853
Ref: 375b11484853
Ref: library/subprocess timeout-behavior11484853
Ref: 375c11484853
Node: Converting an argument sequence to a string on Windows11485640
Ref: library/subprocess converting-an-argument-sequence-to-a-string-on-windows11485799
Ref: 375d11485799
Ref: library/subprocess converting-argument-sequence11485799
Ref: 372b11485799
Node: Disable use of posix_spawn11486963
Ref: library/subprocess disable-posix-spawn11487097
Ref: 375e11487097
Ref: library/subprocess disable-use-of-posix-spawn11487097
Ref: 375f11487097
Node: sched — Event scheduler11487937
Ref: library/sched doc11488109
Ref: 376011488109
Ref: library/sched module-sched11488109
Ref: c411488109
Ref: library/sched sched-event-scheduler11488109
Ref: 376111488109
Ref: library/sched translation-repo11488109
Ref: 376211488109
Ref: library/sched sched scheduler11488379
Ref: 132f11488379
Ref: sched — Event scheduler-Footnote-111490457
Node: Scheduler Objects11490522
Ref: library/sched id111490601
Ref: 376311490601
Ref: library/sched scheduler-objects11490601
Ref: 376411490601
Ref: library/sched sched scheduler enterabs11490733
Ref: 133111490733
Ref: library/sched sched scheduler enter11491627
Ref: 133011491627
Ref: library/sched sched scheduler cancel11492047
Ref: 1ce311492047
Ref: library/sched sched scheduler empty11492234
Ref: 376511492234
Ref: library/sched sched scheduler run11492319
Ref: 132e11492319
Ref: library/sched sched scheduler queue11493366
Ref: 376611493366
Node: queue — A synchronized queue class11493625
Ref: library/queue doc11493794
Ref: 376711493794
Ref: library/queue module-queue11493794
Ref: bb11493794
Ref: library/queue queue-a-synchronized-queue-class11493794
Ref: 376811493794
Ref: library/queue translation-repo11493794
Ref: 376911493794
Ref: library/queue queue Queue11495116
Ref: 159c11495116
Ref: library/queue queue LifoQueue11495481
Ref: 269911495481
Ref: library/queue queue PriorityQueue11495850
Ref: 269a11495850
Ref: library/queue queue SimpleQueue11496848
Ref: d6311496848
Ref: library/queue queue Empty11497025
Ref: 365211497025
Ref: library/queue queue Full11497211
Ref: 365311497211
Ref: library/queue queue ShutDown11497395
Ref: 54411497395
Ref: queue — A synchronized queue class-Footnote-111497684
Node: Queue Objects11497749
Ref: library/queue queue-objects11497863
Ref: 376c11497863
Ref: library/queue queueobjects11497863
Ref: 376d11497863
Ref: library/queue queue Queue qsize11498043
Ref: 376e11498043
Ref: library/queue queue Queue empty11498272
Ref: 376f11498272
Ref: library/queue queue Queue full11498601
Ref: 377011498601
Ref: library/queue queue Queue put11498926
Ref: 376b11498926
Ref: library/queue queue Queue put_nowait11499585
Ref: 31a811499585
Ref: library/queue queue Queue get11499672
Ref: 31a911499672
Ref: library/queue queue Queue get_nowait11500709
Ref: 376a11500709
Ref: library/queue queue Queue task_done11500902
Ref: 364e11500902
Ref: library/queue queue Queue join11501548
Ref: 364f11501548
Node: Waiting for task completion11502050
Ref: library/queue waiting-for-task-completion11502154
Ref: 377111502154
Node: Terminating queues11502808
Ref: library/queue terminating-queues11502912
Ref: 377211502912
Ref: library/queue queue Queue shutdown11503098
Ref: 54311503098
Node: SimpleQueue Objects11504516
Ref: library/queue simplequeue-objects11504630
Ref: 377311504630
Ref: library/queue queue SimpleQueue qsize11504766
Ref: 377411504766
Ref: library/queue queue SimpleQueue empty11504932
Ref: 377511504932
Ref: library/queue queue SimpleQueue put11505149
Ref: 377611505149
Ref: library/queue queue SimpleQueue put_nowait11505927
Ref: 377711505927
Ref: library/queue queue SimpleQueue get11506089
Ref: 377811506089
Ref: library/queue queue SimpleQueue get_nowait11506671
Ref: 377911506671
Node: contextvars — Context Variables11507123
Ref: library/contextvars doc11507302
Ref: 377a11507302
Ref: library/contextvars contextvars-context-variables11507302
Ref: 377b11507302
Ref: library/contextvars module-contextvars11507302
Ref: 2811507302
Ref: library/contextvars translation-repo11507302
Ref: 377c11507302
Ref: contextvars — Context Variables-Footnote-111508162
Node: Context Variables11508204
Ref: library/contextvars context-variables11508325
Ref: 377d11508325
Ref: library/contextvars contextvars ContextVar11508382
Ref: 185d11508382
Ref: library/contextvars contextvars ContextVar name11509089
Ref: 377f11509089
Ref: library/contextvars contextvars ContextVar get11509218
Ref: 377e11509218
Ref: library/contextvars contextvars ContextVar set11509705
Ref: 177a11509705
Ref: library/contextvars contextvars ContextVar reset11510891
Ref: 378011510891
Ref: library/contextvars contextvars Token11511462
Ref: 1e211511462
Ref: library/contextvars contextvars Token var11512036
Ref: 378111512036
Ref: library/contextvars contextvars Token old_value11512174
Ref: 378211512174
Ref: library/contextvars contextvars Token MISSING11512466
Ref: 17e111512466
Node: Manual Context Management11512559
Ref: library/contextvars manual-context-management11512704
Ref: 378311512704
Ref: library/contextvars contextvars copy_context11512777
Ref: 360511512777
Ref: library/contextvars contextvars Context11513254
Ref: 17711513254
Ref: library/contextvars contextvars Context run11515203
Ref: 193311515203
Ref: library/contextvars contextvars Context copy11516533
Ref: 378411516533
Ref: library/contextvars contextvars Context get11516976
Ref: 378511516976
Ref: library/contextvars contextvars Context keys11517418
Ref: 378611517418
Ref: library/contextvars contextvars Context values11517509
Ref: 378711517509
Ref: library/contextvars contextvars Context items11517612
Ref: 378811517612
Node: asyncio support11517751
Ref: library/contextvars asyncio-support11517870
Ref: 378911517870
Node: _thread — Low-level threading API11519567
Ref: library/_thread doc11519701
Ref: 378a11519701
Ref: library/_thread module-_thread11519701
Ref: 211519701
Ref: library/_thread thread-low-level-threading-api11519701
Ref: 378b11519701
Ref: library/_thread translation-repo11519701
Ref: 378c11519701
Ref: library/_thread thread error11520422
Ref: 378d11520422
Ref: library/_thread thread LockType11520595
Ref: 378e11520595
Ref: library/_thread thread start_new_thread11520663
Ref: 4b511520663
Ref: library/_thread thread interrupt_main11521697
Ref: a4611521697
Ref: library/_thread thread exit11522621
Ref: 378f11522621
Ref: library/_thread thread allocate_lock11522770
Ref: 379011522770
Ref: library/_thread thread get_ident11522918
Ref: 379111522918
Ref: library/_thread thread get_native_id11523284
Ref: 379211523284
Ref: library/_thread thread stack_size11523841
Ref: 176011523841
Ref: library/_thread thread TIMEOUT_MAX11525115
Ref: 379311525115
Ref: library/_thread thread lock acquire11525400
Ref: 379411525400
Ref: library/_thread thread lock release11526588
Ref: 379511526588
Ref: library/_thread thread lock locked11526730
Ref: 379611526730
Node: Networking and Interprocess Communication11527631
Ref: library/ipc doc11527796
Ref: 379711527796
Ref: library/ipc ipc11527796
Ref: 379811527796
Ref: library/ipc networking-and-interprocess-communication11527796
Ref: 379911527796
Ref: library/ipc translation-repo11527796
Ref: 379a11527796
Node: asyncio — Asynchronous I/O11528593
Ref: library/asyncio doc11528749
Ref: 379b11528749
Ref: library/asyncio asyncio-asynchronous-i-o11528749
Ref: 379c11528749
Ref: library/asyncio module-asyncio11528749
Ref: b11528749
Ref: library/asyncio asyncio-cli11530493
Ref: 37a811530493
Node: Runners11531739
Ref: library/asyncio-runner doc11531840
Ref: 37a911531840
Ref: library/asyncio-runner runners11531840
Ref: 37aa11531840
Ref: Runners-Footnote-111532258
Node: Running an asyncio Program11532334
Ref: library/asyncio-runner running-an-asyncio-program11532435
Ref: 37ab11532435
Ref: library/asyncio-runner asyncio run11532508
Ref: 2f311532508
Node: Runner context manager11534573
Ref: library/asyncio-runner runner-context-manager11534713
Ref: 37ad11534713
Ref: library/asyncio-runner asyncio Runner11534778
Ref: 2f511534778
Ref: library/asyncio-runner asyncio Runner run11535928
Ref: 193511535928
Ref: library/asyncio-runner asyncio Runner close11536653
Ref: 37ae11536653
Ref: library/asyncio-runner asyncio Runner get_loop11536875
Ref: 37af11536875
Node: Handling Keyboard Interruption11537317
Ref: library/asyncio-runner handling-keyboard-interruption11537422
Ref: 37b011537422
Node: Coroutines and Tasks11538932
Ref: library/asyncio-task doc11539049
Ref: 37b111539049
Ref: library/asyncio-task coroutines-and-tasks11539049
Ref: 37b211539049
Ref: library/asyncio-task translation-repo11539049
Ref: 37b311539049
Node: Coroutines<3>11539529
Ref: library/asyncio-task coroutine11539618
Ref: 379e11539618
Ref: library/asyncio-task coroutines11539618
Ref: 37b411539618
Ref: Coroutines<3>-Footnote-111542913
Node: Awaitables11542992
Ref: library/asyncio-task asyncio-awaitables11543104
Ref: 37b511543104
Ref: library/asyncio-task awaitables11543104
Ref: 37b611543104
Node: Creating Tasks11545702
Ref: library/asyncio-task creating-tasks11545818
Ref: 37b711545818
Ref: library/asyncio-task asyncio create_task11545975
Ref: 1c911545975
Ref: Creating Tasks-Footnote-111548535
Node: Task Cancellation11548608
Ref: library/asyncio-task task-cancellation11548725
Ref: 37b811548725
Node: Task Groups11549795
Ref: library/asyncio-task task-groups11549906
Ref: 37b911549906
Ref: library/asyncio-task taskgroups11549906
Ref: 37ba11549906
Ref: library/asyncio-task asyncio TaskGroup11550073
Ref: 4d211550073
Ref: library/asyncio-task asyncio TaskGroup create_task11550339
Ref: 1cb11550339
Node: Terminating a Task Group11554496
Ref: library/asyncio-task terminating-a-task-group11554568
Ref: 37bb11554568
Node: Sleeping11555897
Ref: library/asyncio-task sleeping11556017
Ref: 37bc11556017
Ref: library/asyncio-task asyncio sleep11556056
Ref: c6611556056
Ref: library/asyncio-task asyncio-example-sleep11556543
Ref: 37bd11556543
Node: Running Tasks Concurrently11557215
Ref: library/asyncio-task running-tasks-concurrently11557342
Ref: 37be11557342
Ref: library/asyncio-task asyncio gather11557417
Ref: 81411557417
Ref: library/asyncio-task asyncio-example-gather11559142
Ref: 37bf11559142
Node: Eager Task Factory11561268
Ref: library/asyncio-task eager-task-factory11561414
Ref: 37c011561414
Ref: library/asyncio-task id111561414
Ref: 37c111561414
Ref: library/asyncio-task asyncio eager_task_factory11561473
Ref: 6a311561473
Ref: library/asyncio-task asyncio create_eager_task_factory11562619
Ref: 6a411562619
Node: Shielding From Cancellation11563299
Ref: library/asyncio-task shielding-from-cancellation11563427
Ref: 37c211563427
Ref: library/asyncio-task asyncio shield11563504
Ref: c6711563504
Node: Timeouts11565186
Ref: library/asyncio-task timeouts11565314
Ref: 37c311565314
Ref: library/asyncio-task asyncio timeout11565353
Ref: 81511565353
Ref: library/asyncio-task asyncio Timeout11567096
Ref: 1a2811567096
Ref: library/asyncio-task asyncio Timeout when11567578
Ref: 37c511567578
Ref: library/asyncio-task asyncio Timeout reschedule11567750
Ref: 37c411567750
Ref: library/asyncio-task asyncio Timeout expired11567855
Ref: 37c611567855
Ref: library/asyncio-task asyncio timeout_at11568695
Ref: 1b9b11568695
Ref: library/asyncio-task asyncio wait_for11569310
Ref: 81611569310
Ref: library/asyncio-task asyncio-example-waitfor11570106
Ref: 37c711570106
Node: Waiting Primitives11570961
Ref: library/asyncio-task waiting-primitives11571080
Ref: 37c811571080
Ref: library/asyncio-task asyncio wait11571139
Ref: 6a811571139
Ref: library/asyncio-task asyncio FIRST_COMPLETED11572340
Ref: 37c911572340
Ref: library/asyncio-task asyncio FIRST_EXCEPTION11572649
Ref: 37ca11572649
Ref: library/asyncio-task asyncio ALL_COMPLETED11573170
Ref: 37cb11573170
Ref: library/asyncio-task asyncio as_completed11573746
Ref: 4c711573746
Node: Running in Threads11576617
Ref: library/asyncio-task running-in-threads11576757
Ref: 37cc11576757
Ref: library/asyncio-task asyncio to_thread11576816
Ref: ae711576816
Node: Scheduling From Other Threads11579025
Ref: library/asyncio-task scheduling-from-other-threads11579160
Ref: 37cd11579160
Ref: library/asyncio-task asyncio run_coroutine_threadsafe11579241
Ref: a8411579241
Node: Introspection11582527
Ref: library/asyncio-task introspection11582655
Ref: 37cf11582655
Ref: library/asyncio-task asyncio current_task11582704
Ref: 6a611582704
Ref: library/asyncio-task asyncio all_tasks11582983
Ref: b5111582983
Ref: library/asyncio-task asyncio iscoroutine11583243
Ref: 6a711583243
Node: Task Object11583368
Ref: library/asyncio-task asyncio-task-obj11583458
Ref: 37d011583458
Ref: library/asyncio-task task-object11583458
Ref: 37d111583458
Ref: library/asyncio-task asyncio Task11583503
Ref: 1c711583503
Ref: library/asyncio-task asyncio Task done11586303
Ref: 37d411586303
Ref: library/asyncio-task asyncio Task result11586519
Ref: 37d511586519
Ref: library/asyncio-task asyncio Task exception11587008
Ref: 37d711587008
Ref: library/asyncio-task asyncio Task add_done_callback11587495
Ref: 37d811587495
Ref: library/asyncio-task asyncio Task remove_done_callback11587810
Ref: 37d911587810
Ref: library/asyncio-task asyncio Task get_stack11588108
Ref: 37da11588108
Ref: library/asyncio-task asyncio Task print_stack11589104
Ref: 1ab811589104
Ref: library/asyncio-task asyncio Task get_coro11589596
Ref: bd111589596
Ref: library/asyncio-task asyncio Task get_context11590015
Ref: 37db11590015
Ref: library/asyncio-task asyncio Task get_name11590179
Ref: bd311590179
Ref: library/asyncio-task asyncio Task set_name11590453
Ref: bd211590453
Ref: library/asyncio-task asyncio Task cancel11590789
Ref: 4d411590789
Ref: library/asyncio-task asyncio-example-task-cancel11592008
Ref: 37dc11592008
Ref: library/asyncio-task asyncio Task cancelled11593263
Ref: 37d211593263
Ref: library/asyncio-task asyncio Task uncancel11593562
Ref: 4d711593562
Ref: library/asyncio-task asyncio Task cancelling11595877
Ref: 4d611595877
Node: Streams11596687
Ref: library/asyncio-stream doc11596823
Ref: 37dd11596823
Ref: library/asyncio-stream asyncio-streams11596823
Ref: 379f11596823
Ref: library/asyncio-stream streams11596823
Ref: 37de11596823
Ref: library/asyncio-stream translation-repo11596823
Ref: 37df11596823
Ref: library/asyncio-stream asyncio-example-stream11597160
Ref: 37e011597160
Ref: library/asyncio-stream asyncio open_connection11597906
Ref: d1011597906
Ref: library/asyncio-stream asyncio start_server11599231
Ref: d1111599231
Ref: library/asyncio-stream asyncio open_unix_connection11600858
Ref: 37e411600858
Ref: library/asyncio-stream asyncio start_unix_server11601847
Ref: 37e611601847
Ref: Streams-Footnote-111603226
Node: StreamReader11603302
Ref: library/asyncio-stream streamreader11603379
Ref: 37e711603379
Ref: library/asyncio-stream asyncio StreamReader11603426
Ref: 1c6511603426
Ref: library/asyncio-stream asyncio StreamReader feed_eof11603813
Ref: 37e811603813
Ref: library/asyncio-stream asyncio StreamReader read11603875
Ref: 37e911603875
Ref: library/asyncio-stream asyncio StreamReader readline11604504
Ref: 37ea11604504
Ref: library/asyncio-stream asyncio StreamReader readexactly11604854
Ref: e7811604854
Ref: library/asyncio-stream asyncio StreamReader readuntil11605146
Ref: 4d111605146
Ref: library/asyncio-stream asyncio StreamReader at_eof11606443
Ref: 37ed11606443
Node: StreamWriter11606573
Ref: library/asyncio-stream streamwriter11606671
Ref: 37ee11606671
Ref: library/asyncio-stream asyncio StreamWriter11606718
Ref: 1a5811606718
Ref: library/asyncio-stream asyncio StreamWriter write11607001
Ref: 37ef11607001
Ref: library/asyncio-stream asyncio StreamWriter writelines11607491
Ref: 37f011607491
Ref: library/asyncio-stream asyncio StreamWriter close11607884
Ref: 37e211607884
Ref: library/asyncio-stream asyncio StreamWriter can_write_eof11608164
Ref: 37f111608164
Ref: library/asyncio-stream asyncio StreamWriter write_eof11608335
Ref: 37f211608335
Ref: library/asyncio-stream asyncio StreamWriter transport11608463
Ref: 37f311608463
Ref: library/asyncio-stream asyncio StreamWriter get_extra_info11608546
Ref: 37f411608546
Ref: library/asyncio-stream asyncio StreamWriter drain11608720
Ref: 1b1111608720
Ref: library/asyncio-stream asyncio StreamWriter start_tls11609309
Ref: 81a11609309
Ref: library/asyncio-stream asyncio StreamWriter is_closing11610327
Ref: d0511610327
Ref: library/asyncio-stream asyncio StreamWriter wait_closed11610490
Ref: d0411610490
Node: Examples<16>11610806
Ref: library/asyncio-stream examples11610883
Ref: 37e111610883
Node: TCP echo client using streams11611080
Ref: library/asyncio-stream asyncio-tcp-echo-client-streams11611196
Ref: 37f511611196
Ref: library/asyncio-stream tcp-echo-client-using-streams11611196
Ref: 37f611611196
Node: TCP echo server using streams11611988
Ref: library/asyncio-stream asyncio-tcp-echo-server-streams11612129
Ref: 37f811612129
Ref: library/asyncio-stream tcp-echo-server-using-streams11612129
Ref: 37f911612129
Node: Get HTTP headers11613175
Ref: library/asyncio-stream get-http-headers11613341
Ref: 37fb11613341
Node: Register an open socket to wait for data using streams11614612
Ref: library/asyncio-stream asyncio-example-create-connection-streams11614740
Ref: 37fc11614740
Ref: library/asyncio-stream register-an-open-socket-to-wait-for-data-using-streams11614740
Ref: 37fd11614740
Node: Synchronization Primitives11616169
Ref: library/asyncio-sync doc11616297
Ref: 380111616297
Ref: library/asyncio-sync asyncio-sync11616297
Ref: 37a211616297
Ref: library/asyncio-sync synchronization-primitives11616297
Ref: 380211616297
Ref: library/asyncio-sync translation-repo11616297
Ref: 380311616297
Ref: Synchronization Primitives-Footnote-111617374
Node: Lock11617447
Ref: library/asyncio-sync lock11617528
Ref: 380411617528
Ref: library/asyncio-sync asyncio Lock11617559
Ref: c6811617559
Ref: library/asyncio-sync asyncio Lock acquire11618227
Ref: 380511618227
Ref: library/asyncio-sync asyncio Lock release11618717
Ref: 380611618717
Ref: library/asyncio-sync asyncio Lock locked11618934
Ref: 380711618934
Node: Event11619016
Ref: library/asyncio-sync event11619115
Ref: 380811619115
Ref: library/asyncio-sync asyncio Event11619148
Ref: 2f411619148
Ref: library/asyncio-sync asyncio-example-sync-event11619683
Ref: 380c11619683
Ref: library/asyncio-sync asyncio Event wait11620312
Ref: 380b11620312
Ref: library/asyncio-sync asyncio Event set11620518
Ref: 380911620518
Ref: library/asyncio-sync asyncio Event clear11620658
Ref: 380a11620658
Ref: library/asyncio-sync asyncio Event is_set11620859
Ref: 380d11620859
Node: Condition11620937
Ref: library/asyncio-sync condition11621041
Ref: 380e11621041
Ref: library/asyncio-sync asyncio Condition11621082
Ref: c6911621082
Ref: library/asyncio-sync asyncio Condition acquire11622320
Ref: 380f11622320
Ref: library/asyncio-sync asyncio Condition notify11622519
Ref: 19df11622519
Ref: library/asyncio-sync asyncio Condition locked11622883
Ref: 381011622883
Ref: library/asyncio-sync asyncio Condition notify_all11622976
Ref: 381111622976
Ref: library/asyncio-sync asyncio Condition release11623354
Ref: 381211623354
Ref: library/asyncio-sync asyncio Condition wait11623516
Ref: 1a0811623516
Ref: library/asyncio-sync asyncio Condition wait_for11624256
Ref: 381311624256
Node: Semaphore11624604
Ref: library/asyncio-sync semaphore11624719
Ref: 381411624719
Ref: library/asyncio-sync asyncio Semaphore11624760
Ref: c6a11624760
Ref: library/asyncio-sync asyncio Semaphore acquire11625878
Ref: 1a0911625878
Ref: library/asyncio-sync asyncio Semaphore locked11626162
Ref: 381611626162
Ref: library/asyncio-sync asyncio Semaphore release11626266
Ref: 381511626266
Node: BoundedSemaphore11626580
Ref: library/asyncio-sync boundedsemaphore11626693
Ref: 381711626693
Ref: library/asyncio-sync asyncio BoundedSemaphore11626748
Ref: c6b11626748
Node: Barrier11627113
Ref: library/asyncio-sync barrier11627208
Ref: 381811627208
Ref: library/asyncio-sync asyncio Barrier11627245
Ref: 81711627245
Ref: library/asyncio-sync asyncio-example-barrier11627841
Ref: 381a11627841
Ref: library/asyncio-sync asyncio Barrier wait11628709
Ref: 381911628709
Ref: library/asyncio-sync asyncio Barrier reset11629784
Ref: 381b11629784
Ref: library/asyncio-sync asyncio Barrier abort11630080
Ref: 381c11630080
Ref: library/asyncio-sync asyncio Barrier parties11630393
Ref: 381d11630393
Ref: library/asyncio-sync asyncio Barrier n_waiting11630483
Ref: 381e11630483
Ref: library/asyncio-sync asyncio Barrier broken11630603
Ref: 381f11630603
Ref: library/asyncio-sync asyncio BrokenBarrierError11630720
Ref: 81811630720
Node: Subprocesses11631195
Ref: library/asyncio-subprocess doc11631322
Ref: 382011631322
Ref: library/asyncio-subprocess asyncio-subprocess11631322
Ref: 37a011631322
Ref: library/asyncio-subprocess subprocesses11631322
Ref: 382111631322
Ref: library/asyncio-subprocess translation-repo11631322
Ref: 382211631322
Ref: library/asyncio-subprocess asyncio-example-subprocess-shell11631610
Ref: 382311631610
Ref: Subprocesses-Footnote-111632906
Ref: Subprocesses-Footnote-211632985
Node: Creating Subprocesses11633069
Ref: library/asyncio-subprocess creating-subprocesses11633160
Ref: 382511633160
Ref: library/asyncio-subprocess asyncio create_subprocess_exec11633225
Ref: c6d11633225
Ref: library/asyncio-subprocess asyncio create_subprocess_shell11633949
Ref: c6e11633949
Ref: Creating Subprocesses-Footnote-111635624
Node: Constants<7>11635694
Ref: library/asyncio-subprocess constants11635823
Ref: 383011635823
Ref: library/asyncio-subprocess asyncio subprocess PIPE11635864
Ref: 383111635864
Ref: library/asyncio-subprocess asyncio subprocess STDOUT11636310
Ref: 383311636310
Ref: library/asyncio-subprocess asyncio subprocess DEVNULL11636496
Ref: 383411636496
Node: Interacting with Subprocesses11636777
Ref: library/asyncio-subprocess interacting-with-subprocesses11636876
Ref: 383511636876
Ref: library/asyncio-subprocess asyncio subprocess Process11637207
Ref: 382811637207
Ref: library/asyncio-subprocess asyncio subprocess Process wait11638186
Ref: 383611638186
Ref: library/asyncio-subprocess asyncio subprocess Process communicate11638691
Ref: 1a8711638691
Ref: library/asyncio-subprocess asyncio subprocess Process send_signal11640055
Ref: 193211640055
Ref: library/asyncio-subprocess asyncio subprocess Process terminate11640469
Ref: 383911640469
Ref: library/asyncio-subprocess asyncio subprocess Process kill11640751
Ref: 383a11640751
Ref: library/asyncio-subprocess asyncio subprocess Process stdin11640995
Ref: 383211640995
Ref: library/asyncio-subprocess asyncio subprocess Process stdout11641157
Ref: 382611641157
Ref: library/asyncio-subprocess asyncio subprocess Process stderr11641322
Ref: 382711641322
Ref: library/asyncio-subprocess asyncio subprocess Process pid11641832
Ref: 383b11641832
Ref: library/asyncio-subprocess asyncio subprocess Process returncode11642071
Ref: 383811642071
Node: Subprocess and Threads11642429
Ref: library/asyncio-subprocess asyncio-subprocess-threads11642538
Ref: 383711642538
Ref: library/asyncio-subprocess subprocess-and-threads11642538
Ref: 383c11642538
Node: Examples<17>11643050
Ref: library/asyncio-subprocess examples11643159
Ref: 382411643159
Ref: library/asyncio-subprocess asyncio-example-create-subprocess-exec11643343
Ref: 383d11643343
Node: Queues11644146
Ref: library/asyncio-queue doc11644261
Ref: 383f11644261
Ref: library/asyncio-queue asyncio-queues11644261
Ref: 37a111644261
Ref: library/asyncio-queue queues11644261
Ref: 384011644261
Ref: library/asyncio-queue translation-repo11644261
Ref: 384111644261
Ref: Queues-Footnote-111644953
Node: Queue11645027
Ref: library/asyncio-queue queue11645098
Ref: 384311645098
Ref: library/asyncio-queue asyncio Queue11645131
Ref: c6c11645131
Ref: library/asyncio-queue asyncio Queue maxsize11645746
Ref: 384611645746
Ref: library/asyncio-queue asyncio Queue empty11645824
Ref: 384711645824
Ref: library/asyncio-queue asyncio Queue full11645926
Ref: 384811645926
Ref: library/asyncio-queue asyncio Queue get11646182
Ref: 384411646182
Ref: library/asyncio-queue asyncio Queue get_nowait11646487
Ref: 384911646487
Ref: library/asyncio-queue asyncio Queue join11646623
Ref: fc811646623
Ref: library/asyncio-queue asyncio Queue put11647117
Ref: 384b11647117
Ref: library/asyncio-queue asyncio Queue put_nowait11647371
Ref: 384c11647371
Ref: library/asyncio-queue asyncio Queue qsize11647555
Ref: 384511647555
Ref: library/asyncio-queue asyncio Queue shutdown11647634
Ref: 4cd11647634
Ref: library/asyncio-queue asyncio Queue task_done11649193
Ref: fc911649193
Node: Priority Queue11649901
Ref: library/asyncio-queue priority-queue11649991
Ref: 384e11649991
Ref: library/asyncio-queue asyncio PriorityQueue11650042
Ref: 384f11650042
Node: LIFO Queue11650250
Ref: library/asyncio-queue lifo-queue11650349
Ref: 385011650349
Ref: library/asyncio-queue asyncio LifoQueue11650392
Ref: 385111650392
Node: Exceptions<14>11650536
Ref: library/asyncio-queue exceptions11650633
Ref: 385211650633
Ref: library/asyncio-queue asyncio QueueEmpty11650676
Ref: 384a11650676
Ref: library/asyncio-queue asyncio QueueFull11650818
Ref: 384d11650818
Ref: library/asyncio-queue asyncio QueueShutDown11650975
Ref: 4ce11650975
Node: Examples<18>11651163
Ref: library/asyncio-queue examples11651241
Ref: 384211651241
Ref: library/asyncio-queue asyncio-example-queue-dist11651280
Ref: 385311651280
Node: Exceptions<15>11653038
Ref: library/asyncio-exceptions doc11653165
Ref: 385411653165
Ref: library/asyncio-exceptions asyncio-exceptions11653165
Ref: 385511653165
Ref: library/asyncio-exceptions exceptions11653165
Ref: 385611653165
Ref: library/asyncio-exceptions translation-repo11653165
Ref: 385711653165
Ref: library/asyncio-exceptions asyncio TimeoutError11653321
Ref: 1a9d11653321
Ref: library/asyncio-exceptions asyncio CancelledError11653573
Ref: 4d511653573
Ref: library/asyncio-exceptions asyncio InvalidStateError11653972
Ref: 37d611653972
Ref: library/asyncio-exceptions asyncio SendfileNotAvailableError11654211
Ref: 385811654211
Ref: library/asyncio-exceptions asyncio IncompleteReadError11654394
Ref: 1cd011654394
Ref: library/asyncio-exceptions asyncio IncompleteReadError expected11654610
Ref: 385911654610
Ref: library/asyncio-exceptions asyncio IncompleteReadError partial11654705
Ref: 37eb11654705
Ref: library/asyncio-exceptions asyncio LimitOverrunError11654828
Ref: 37ec11654828
Ref: library/asyncio-exceptions asyncio LimitOverrunError consumed11654990
Ref: 385a11654990
Ref: Exceptions<15>-Footnote-111655109
Node: Call Graph Introspection11655188
Ref: library/asyncio-graph doc11655319
Ref: 385b11655319
Ref: library/asyncio-graph asyncio-graph11655319
Ref: 385c11655319
Ref: library/asyncio-graph call-graph-introspection11655319
Ref: 385d11655319
Ref: library/asyncio-graph translation-repo11655319
Ref: 385e11655319
Ref: library/asyncio-graph asyncio print_call_graph11655806
Ref: 1cd11655806
Ref: library/asyncio-graph asyncio format_call_graph11657729
Ref: 385f11657729
Ref: library/asyncio-graph asyncio capture_call_graph11657991
Ref: 1cc11657991
Ref: Call Graph Introspection-Footnote-111659215
Node: Low level utility functions11659288
Ref: library/asyncio-graph low-level-utility-functions11659376
Ref: 386011659376
Ref: library/asyncio-graph asyncio future_add_to_awaited_by11659893
Ref: 386111659893
Ref: library/asyncio-graph asyncio future_discard_from_awaited_by11660363
Ref: 386211660363
Node: Event Loop11660666
Ref: library/asyncio-eventloop doc11660790
Ref: 386311660790
Ref: library/asyncio-eventloop asyncio-event-loop11660790
Ref: f7811660790
Ref: library/asyncio-eventloop event-loop11660790
Ref: 386411660790
Ref: library/asyncio-eventloop translation-repo11660790
Ref: 386511660790
Ref: library/asyncio-eventloop asyncio get_running_loop11661620
Ref: d0311661620
Ref: library/asyncio-eventloop asyncio get_event_loop11661898
Ref: 2f211661898
Ref: library/asyncio-eventloop asyncio set_event_loop11663113
Ref: 1b3d11663113
Ref: library/asyncio-eventloop asyncio new_event_loop11663228
Ref: 37ac11663228
Ref: Event Loop-Footnote-111664507
Ref: Event Loop-Footnote-211664581
Node: Event Loop Methods11664661
Ref: library/asyncio-eventloop asyncio-event-loop-methods11664751
Ref: 386c11664751
Ref: library/asyncio-eventloop event-loop-methods11664751
Ref: 386711664751
Node: Running and stopping the loop11665334
Ref: library/asyncio-eventloop running-and-stopping-the-loop11665447
Ref: 386d11665447
Ref: library/asyncio-eventloop asyncio loop run_until_complete11665528
Ref: e7411665528
Ref: library/asyncio-eventloop asyncio loop run_forever11665844
Ref: 386e11665844
Ref: library/asyncio-eventloop asyncio loop stop11666564
Ref: e7911666564
Ref: library/asyncio-eventloop asyncio loop is_running11666617
Ref: 386f11666617
Ref: library/asyncio-eventloop asyncio loop is_closed11666713
Ref: fc511666713
Ref: library/asyncio-eventloop asyncio loop close11666798
Ref: 387011666798
Ref: library/asyncio-eventloop asyncio loop shutdown_asyncgens11667203
Ref: e7b11667203
Ref: library/asyncio-eventloop asyncio loop shutdown_default_executor11667884
Ref: ae611667884
Node: Scheduling callbacks11668901
Ref: library/asyncio-eventloop scheduling-callbacks11669051
Ref: 387111669051
Ref: library/asyncio-eventloop asyncio loop call_soon11669114
Ref: cfc11669114
Ref: library/asyncio-eventloop asyncio loop call_soon_threadsafe11669826
Ref: cfd11669826
Ref: library/asyncio-eventloop asyncio-pass-keywords11670654
Ref: 387211670654
Ref: Scheduling callbacks-Footnote-111671149
Node: Scheduling delayed callbacks11671191
Ref: library/asyncio-eventloop asyncio-delayed-calls11671338
Ref: 387311671338
Ref: library/asyncio-eventloop scheduling-delayed-callbacks11671338
Ref: 387411671338
Ref: library/asyncio-eventloop asyncio loop call_later11671571
Ref: cfe11671571
Ref: library/asyncio-eventloop asyncio loop call_at11672959
Ref: cff11672959
Ref: library/asyncio-eventloop asyncio loop time11673933
Ref: 387511673933
Ref: Scheduling delayed callbacks-Footnote-111674377
Ref: Scheduling delayed callbacks-Footnote-211674419
Node: Creating Futures and Tasks11674461
Ref: library/asyncio-eventloop creating-futures-and-tasks11674615
Ref: 387611674615
Ref: library/asyncio-eventloop asyncio loop create_future11674690
Ref: e7611674690
Ref: library/asyncio-eventloop asyncio loop create_task11675048
Ref: 1ca11675048
Ref: library/asyncio-eventloop asyncio loop set_task_factory11676910
Ref: 1c811676910
Ref: library/asyncio-eventloop asyncio loop get_task_factory11677816
Ref: fc711677816
Node: Opening network connections11677926
Ref: library/asyncio-eventloop opening-network-connections11678076
Ref: 387711678076
Ref: library/asyncio-eventloop asyncio loop create_connection11678153
Ref: 81911678153
Ref: library/asyncio-eventloop asyncio loop create_datagram_endpoint11685104
Ref: 93d11685104
Ref: library/asyncio-eventloop asyncio loop create_unix_connection11688987
Ref: 37e511688987
Ref: Opening network connections-Footnote-111690052
Ref: Opening network connections-Footnote-211690111
Node: Creating network servers11690170
Ref: library/asyncio-eventloop creating-network-servers11690312
Ref: 387f11690312
Ref: library/asyncio-eventloop loop-create-server11690383
Ref: 37a311690383
Ref: library/asyncio-eventloop asyncio loop create_server11690383
Ref: d0b11690383
Ref: library/asyncio-eventloop asyncio loop create_unix_server11695108
Ref: 4cb11695108
Ref: library/asyncio-eventloop asyncio loop connect_accepted_socket11696379
Ref: 9e011696379
Node: Transferring files11697949
Ref: library/asyncio-eventloop transferring-files11698075
Ref: 388111698075
Ref: library/asyncio-eventloop asyncio loop sendfile11698134
Ref: 388211698134
Node: TLS Upgrade11699190
Ref: library/asyncio-eventloop tls-upgrade11699317
Ref: 388311699317
Ref: library/asyncio-eventloop asyncio loop start_tls11699362
Ref: d0111699362
Node: Watching file descriptors11701307
Ref: library/asyncio-eventloop watching-file-descriptors11701452
Ref: 388411701452
Ref: library/asyncio-eventloop asyncio loop add_reader11701525
Ref: 380011701525
Ref: library/asyncio-eventloop asyncio loop remove_reader11701840
Ref: 388511701840
Ref: library/asyncio-eventloop asyncio loop add_writer11702021
Ref: 388611702021
Ref: library/asyncio-eventloop asyncio loop remove_writer11702438
Ref: 388711702438
Node: Working with socket objects directly11702708
Ref: library/asyncio-eventloop working-with-socket-objects-directly11702845
Ref: 388911702845
Ref: library/asyncio-eventloop asyncio loop sock_recv11703296
Ref: e0d11703296
Ref: library/asyncio-eventloop asyncio loop sock_recv_into11703766
Ref: d0211703766
Ref: library/asyncio-eventloop asyncio loop sock_recvfrom11704072
Ref: 81c11704072
Ref: library/asyncio-eventloop asyncio loop sock_recvfrom_into11704373
Ref: 81d11704373
Ref: library/asyncio-eventloop asyncio loop sock_sendall11704711
Ref: e0e11704711
Ref: library/asyncio-eventloop asyncio loop sock_sendto11705468
Ref: 81b11705468
Ref: library/asyncio-eventloop asyncio loop sock_connect11705744
Ref: fca11705744
Ref: library/asyncio-eventloop asyncio loop sock_accept11706376
Ref: e0f11706376
Ref: library/asyncio-eventloop asyncio loop sock_sendfile11707205
Ref: d0611707205
Node: DNS11708406
Ref: library/asyncio-eventloop dns11708536
Ref: 388a11708536
Ref: library/asyncio-eventloop asyncio loop getaddrinfo11708565
Ref: e1011708565
Ref: library/asyncio-eventloop asyncio loop getnameinfo11708727
Ref: e1111708727
Node: Working with pipes11709571
Ref: library/asyncio-eventloop working-with-pipes11709677
Ref: 388b11709677
Ref: library/asyncio-eventloop asyncio loop connect_read_pipe11709736
Ref: 382c11709736
Ref: library/asyncio-eventloop asyncio loop connect_write_pipe11710307
Ref: 382d11710307
Node: Unix signals11711144
Ref: library/asyncio-eventloop unix-signals11711288
Ref: 388e11711288
Ref: library/asyncio-eventloop loop-add-signal-handler11711335
Ref: 37a511711335
Ref: library/asyncio-eventloop asyncio loop add_signal_handler11711335
Ref: 388f11711335
Ref: library/asyncio-eventloop asyncio loop remove_signal_handler11712125
Ref: 389011712125
Node: Executing code in thread or process pools11712434
Ref: library/asyncio-eventloop executing-code-in-thread-or-process-pools11712578
Ref: 389111712578
Ref: library/asyncio-eventloop asyncio loop run_in_executor11712683
Ref: ae811712683
Ref: library/asyncio-eventloop asyncio loop set_default_executor11715653
Ref: 94b11715653
Node: Error Handling API11716024
Ref: library/asyncio-eventloop error-handling-api11716175
Ref: 389211716175
Ref: library/asyncio-eventloop asyncio loop set_exception_handler11716300
Ref: 389311716300
Ref: library/asyncio-eventloop asyncio loop get_exception_handler11717159
Ref: e7711717159
Ref: library/asyncio-eventloop asyncio loop default_exception_handler11717335
Ref: 389511717335
Ref: library/asyncio-eventloop asyncio loop call_exception_handler11717710
Ref: 389411717710
Node: Enabling debug mode11718915
Ref: library/asyncio-eventloop enabling-debug-mode11719045
Ref: 389611719045
Ref: library/asyncio-eventloop asyncio loop get_debug11719106
Ref: fc411719106
Ref: library/asyncio-eventloop asyncio loop set_debug11719361
Ref: fc311719361
Ref: library/asyncio-eventloop asyncio loop slow_callback_duration11719580
Ref: 389711719580
Node: Running Subprocesses11719909
Ref: library/asyncio-eventloop running-subprocesses11720012
Ref: 389811720012
Ref: library/asyncio-eventloop loop-subprocess-exec11720538
Ref: 37a411720538
Ref: library/asyncio-eventloop asyncio loop subprocess_exec11720538
Ref: 382911720538
Ref: library/asyncio-eventloop asyncio loop subprocess_shell11724588
Ref: 382a11724588
Ref: Running Subprocesses-Footnote-111726017
Node: Callback Handles11726087
Ref: library/asyncio-eventloop callback-handles11726200
Ref: 386811726200
Ref: library/asyncio-eventloop asyncio Handle11726255
Ref: 1e6c11726255
Ref: library/asyncio-eventloop asyncio Handle get_context11726401
Ref: 389b11726401
Ref: library/asyncio-eventloop asyncio Handle cancel11726567
Ref: 389c11726567
Ref: library/asyncio-eventloop asyncio Handle cancelled11726720
Ref: d1211726720
Ref: library/asyncio-eventloop asyncio TimerHandle11726844
Ref: 1ac511726844
Ref: library/asyncio-eventloop asyncio TimerHandle when11727041
Ref: d0f11727041
Node: Server Objects11727288
Ref: library/asyncio-eventloop server-objects11727409
Ref: 386911727409
Ref: library/asyncio-eventloop asyncio Server11727696
Ref: d0a11727696
Ref: library/asyncio-eventloop asyncio Server close11728397
Ref: 37e311728397
Ref: library/asyncio-eventloop asyncio Server close_clients11728826
Ref: 4cf11728826
Ref: library/asyncio-eventloop asyncio Server abort_clients11729194
Ref: 4d011729194
Ref: library/asyncio-eventloop asyncio Server get_loop11729636
Ref: d0911729636
Ref: library/asyncio-eventloop asyncio Server start_serving11729767
Ref: d0c11729767
Ref: library/asyncio-eventloop asyncio Server serve_forever11730383
Ref: d0d11730383
Ref: library/asyncio-eventloop asyncio Server is_serving11731278
Ref: d0e11731278
Ref: library/asyncio-eventloop asyncio Server wait_closed11731416
Ref: 1a2711731416
Ref: library/asyncio-eventloop asyncio Server sockets11731571
Ref: e1211731571
Ref: library/asyncio-eventloop asyncio-event-loops11731924
Ref: 389e11731924
Node: Event Loop Implementations11731924
Ref: library/asyncio-eventloop asyncio-event-loop-implementations11732041
Ref: 389f11732041
Ref: library/asyncio-eventloop event-loop-implementations11732041
Ref: 386a11732041
Ref: library/asyncio-eventloop asyncio SelectorEventLoop11732306
Ref: 31411732306
Ref: library/asyncio-eventloop asyncio ProactorEventLoop11732908
Ref: 81e11732908
Ref: library/asyncio-eventloop asyncio EventLoop11733185
Ref: 1a4f11733185
Ref: library/asyncio-eventloop asyncio AbstractEventLoop11733496
Ref: b5a11733496
Ref: Event Loop Implementations-Footnote-111733793
Node: Examples<19>11733872
Ref: library/asyncio-eventloop examples11733966
Ref: 386b11733966
Node: Hello World with call_soon11734565
Ref: library/asyncio-eventloop asyncio-example-lowlevel-helloworld11734689
Ref: 38a011734689
Ref: library/asyncio-eventloop hello-world-with-call-soon11734689
Ref: 38a111734689
Node: Display the current date with call_later11735467
Ref: library/asyncio-eventloop asyncio-example-call-later11735639
Ref: 38a211735639
Ref: library/asyncio-eventloop display-the-current-date-with-call-later11735639
Ref: 38a311735639
Node: Watch a file descriptor for read events11736635
Ref: library/asyncio-eventloop asyncio-example-watch-fd11736823
Ref: 37ff11736823
Ref: library/asyncio-eventloop watch-a-file-descriptor-for-read-events11736823
Ref: 38a411736823
Node: Set signal handlers for SIGINT and SIGTERM11738147
Ref: library/asyncio-eventloop asyncio-example-unix-signals11738286
Ref: 38a511738286
Ref: library/asyncio-eventloop set-signal-handlers-for-sigint-and-sigterm11738286
Ref: 38a611738286
Node: Futures11739214
Ref: library/asyncio-future doc11739338
Ref: 36c911739338
Ref: library/asyncio-future asyncio-futures11739338
Ref: 37a711739338
Ref: library/asyncio-future futures11739338
Ref: 38a711739338
Ref: library/asyncio-future translation-repo11739338
Ref: 38a811739338
Ref: Futures-Footnote-111739705
Ref: Futures-Footnote-211739781
Node: Future Functions11739862
Ref: library/asyncio-future future-functions11739944
Ref: 38a911739944
Ref: library/asyncio-future asyncio isfuture11739999
Ref: 38aa11739999
Ref: library/asyncio-future asyncio ensure_future11740307
Ref: e7311740307
Ref: library/asyncio-future asyncio wrap_future11741649
Ref: 1c6411741649
Node: Future Object11741993
Ref: library/asyncio-future asyncio-future-obj11742075
Ref: 38ab11742075
Ref: library/asyncio-future future-object11742075
Ref: 38ac11742075
Ref: library/asyncio-future asyncio Future11742124
Ref: dc811742124
Ref: library/asyncio-future asyncio Future result11743257
Ref: 38ad11743257
Ref: library/asyncio-future asyncio Future set_result11743872
Ref: 37d311743872
Ref: library/asyncio-future asyncio Future set_exception11744068
Ref: e7a11744068
Ref: library/asyncio-future asyncio Future done11744272
Ref: 38ae11744272
Ref: library/asyncio-future asyncio Future cancelled11744535
Ref: 38af11744535
Ref: library/asyncio-future asyncio Future add_done_callback11744840
Ref: d0011744840
Ref: library/asyncio-future asyncio Future remove_done_callback11745833
Ref: 18f911745833
Ref: library/asyncio-future asyncio Future cancel11746065
Ref: 1b9111746065
Ref: library/asyncio-future asyncio Future exception11746423
Ref: 38b011746423
Ref: library/asyncio-future asyncio Future get_loop11746867
Ref: d0811746867
Ref: library/asyncio-future asyncio-example-future11746994
Ref: 38b111746994
Ref: Future Object-Footnote-111749204
Node: Transports and Protocols11749246
Ref: library/asyncio-protocol doc11749368
Ref: 38b211749368
Ref: library/asyncio-protocol asyncio-transports-protocols11749368
Ref: 37a611749368
Ref: library/asyncio-protocol translation-repo11749368
Ref: 38b311749368
Ref: library/asyncio-protocol transports-and-protocols11749368
Ref: 38b411749368
Node: Transports11751748
Ref: library/asyncio-protocol asyncio-transport11751840
Ref: 387911751840
Ref: library/asyncio-protocol transports11751840
Ref: 38b511751840
Ref: Transports-Footnote-111752582
Node: Transports Hierarchy11752661
Ref: library/asyncio-protocol transports-hierarchy11752751
Ref: 38bc11752751
Ref: library/asyncio-protocol asyncio BaseTransport11752814
Ref: 38b711752814
Ref: library/asyncio-protocol asyncio WriteTransport11752944
Ref: 388d11752944
Ref: library/asyncio-protocol asyncio ReadTransport11753276
Ref: 388c11753276
Ref: library/asyncio-protocol asyncio Transport11753604
Ref: 38b811753604
Ref: library/asyncio-protocol asyncio DatagramTransport11754208
Ref: 1b0f11754208
Ref: library/asyncio-protocol asyncio SubprocessTransport11754452
Ref: 389a11754452
Node: Base Transport11754779
Ref: library/asyncio-protocol base-transport11754898
Ref: 38bd11754898
Ref: library/asyncio-protocol asyncio BaseTransport close11754949
Ref: 387c11754949
Ref: library/asyncio-protocol asyncio BaseTransport is_closing11755378
Ref: e7511755378
Ref: library/asyncio-protocol asyncio BaseTransport get_extra_info11755485
Ref: c9511755485
Ref: library/asyncio-protocol asyncio BaseTransport set_protocol11757643
Ref: 38c111757643
Ref: library/asyncio-protocol asyncio BaseTransport get_protocol11757828
Ref: 38c211757828
Node: Read-only Transports11757906
Ref: library/asyncio-protocol read-only-transports11758026
Ref: 38c311758026
Ref: library/asyncio-protocol asyncio ReadTransport is_reading11758089
Ref: d1311758089
Ref: library/asyncio-protocol asyncio ReadTransport pause_reading11758222
Ref: d1511758222
Ref: library/asyncio-protocol asyncio ReadTransport resume_reading11758596
Ref: d1411758596
Node: Write-only Transports11758939
Ref: library/asyncio-protocol write-only-transports11759064
Ref: 38c411759064
Ref: library/asyncio-protocol asyncio WriteTransport abort11759129
Ref: 389d11759129
Ref: library/asyncio-protocol asyncio WriteTransport can_write_eof11759468
Ref: 38c511759468
Ref: library/asyncio-protocol asyncio WriteTransport get_write_buffer_size11759625
Ref: 38c711759625
Ref: library/asyncio-protocol asyncio WriteTransport get_write_buffer_limits11759752
Ref: fc611759752
Ref: library/asyncio-protocol asyncio WriteTransport set_write_buffer_limits11760068
Ref: 38c811760068
Ref: library/asyncio-protocol asyncio WriteTransport write11761480
Ref: 17b211761480
Ref: library/asyncio-protocol asyncio WriteTransport writelines11761679
Ref: 17b111761679
Ref: library/asyncio-protocol asyncio WriteTransport write_eof11761963
Ref: 38c611761963
Node: Datagram Transports11762252
Ref: library/asyncio-protocol datagram-transports11762378
Ref: 38cb11762378
Ref: library/asyncio-protocol asyncio DatagramTransport sendto11762439
Ref: 4cc11762439
Ref: library/asyncio-protocol asyncio DatagramTransport abort11763056
Ref: 38cc11763056
Node: Subprocess Transports11763398
Ref: library/asyncio-protocol asyncio-subprocess-transports11763494
Ref: 382e11763494
Ref: library/asyncio-protocol subprocess-transports11763494
Ref: 38cd11763494
Ref: library/asyncio-protocol asyncio SubprocessTransport get_pid11763559
Ref: 38ce11763559
Ref: library/asyncio-protocol asyncio SubprocessTransport get_pipe_transport11763657
Ref: 38cf11763657
Ref: library/asyncio-protocol asyncio SubprocessTransport get_returncode11764403
Ref: 38d011764403
Ref: library/asyncio-protocol asyncio SubprocessTransport kill11764638
Ref: 38d111764638
Ref: library/asyncio-protocol asyncio SubprocessTransport send_signal11764899
Ref: 38d311764899
Ref: library/asyncio-protocol asyncio SubprocessTransport terminate11765058
Ref: 38d211765058
Ref: library/asyncio-protocol asyncio SubprocessTransport close11765377
Ref: 38d411765377
Node: Protocols<2>11765603
Ref: library/asyncio-protocol asyncio-protocol11765716
Ref: 387811765716
Ref: library/asyncio-protocol protocols11765716
Ref: 38b611765716
Ref: Protocols<2>-Footnote-111766509
Node: Base Protocols11766587
Ref: library/asyncio-protocol base-protocols11766672
Ref: 38d511766672
Ref: library/asyncio-protocol asyncio BaseProtocol11766723
Ref: 38b911766723
Ref: library/asyncio-protocol asyncio Protocol11766816
Ref: 38ba11766816
Ref: library/asyncio-protocol asyncio BufferedProtocol11766950
Ref: c9611766950
Ref: library/asyncio-protocol asyncio DatagramProtocol11767107
Ref: 8df11767107
Ref: library/asyncio-protocol asyncio SubprocessProtocol11767224
Ref: 389911767224
Node: Base Protocol11767391
Ref: library/asyncio-protocol base-protocol11767504
Ref: 38d611767504
Ref: library/asyncio-protocol asyncio BaseProtocol connection_made11767827
Ref: 387a11767827
Ref: library/asyncio-protocol asyncio BaseProtocol connection_lost11768081
Ref: 38be11768081
Ref: library/asyncio-protocol asyncio BaseProtocol pause_writing11768624
Ref: 38c911768624
Ref: library/asyncio-protocol asyncio BaseProtocol resume_writing11768740
Ref: 38ca11768740
Node: Streaming Protocols11769204
Ref: library/asyncio-protocol streaming-protocols11769331
Ref: 38d711769331
Ref: library/asyncio-protocol asyncio Protocol data_received11769741
Ref: 1aea11769741
Ref: library/asyncio-protocol asyncio Protocol eof_received11770422
Ref: 38d811770422
Node: Buffered Streaming Protocols11771286
Ref: library/asyncio-protocol buffered-streaming-protocols11771418
Ref: 38d911771418
Ref: library/asyncio-protocol asyncio BufferedProtocol get_buffer11772111
Ref: 38da11772111
Ref: library/asyncio-protocol asyncio BufferedProtocol buffer_updated11772584
Ref: 38db11772584
Ref: library/asyncio-protocol asyncio BufferedProtocol eof_received11772785
Ref: 38dc11772785
Node: Datagram Protocols11773357
Ref: library/asyncio-protocol datagram-protocols11773490
Ref: 38dd11773490
Ref: library/asyncio-protocol asyncio DatagramProtocol datagram_received11773688
Ref: 38de11773688
Ref: library/asyncio-protocol asyncio DatagramProtocol error_received11773953
Ref: 38df11773953
Node: Subprocess Protocols11774888
Ref: library/asyncio-protocol asyncio-subprocess-protocols11774984
Ref: 382f11774984
Ref: library/asyncio-protocol subprocess-protocols11774984
Ref: 38e011774984
Ref: library/asyncio-protocol asyncio SubprocessProtocol pipe_data_received11775222
Ref: 1b3811775222
Ref: library/asyncio-protocol asyncio SubprocessProtocol pipe_connection_lost11775495
Ref: 38e111775495
Ref: library/asyncio-protocol asyncio SubprocessProtocol process_exited11775705
Ref: 1b3711775705
Node: Examples<20>11775921
Ref: library/asyncio-protocol examples11776015
Ref: 38bb11776015
Node: TCP Echo Server11776270
Ref: library/asyncio-protocol asyncio-example-tcp-echo-server-protocol11776358
Ref: 37fa11776358
Ref: library/asyncio-protocol tcp-echo-server11776358
Ref: 38e211776358
Node: TCP Echo Client11777636
Ref: library/asyncio-protocol asyncio-example-tcp-echo-client-protocol11777748
Ref: 37f711777748
Ref: library/asyncio-protocol tcp-echo-client11777748
Ref: 38e311777748
Node: UDP Echo Server11779310
Ref: library/asyncio-protocol asyncio-udp-echo-server-protocol11779422
Ref: 387e11779422
Ref: library/asyncio-protocol udp-echo-server11779422
Ref: 38e411779422
Node: UDP Echo Client11780560
Ref: library/asyncio-protocol asyncio-udp-echo-client-protocol11780684
Ref: 387d11780684
Ref: library/asyncio-protocol udp-echo-client11780684
Ref: 38e511780684
Node: Connecting Existing Sockets11782218
Ref: library/asyncio-protocol asyncio-example-create-connection11782370
Ref: 37fe11782370
Ref: library/asyncio-protocol connecting-existing-sockets11782370
Ref: 38e611782370
Node: loop subprocess_exec and SubprocessProtocol11784288
Ref: library/asyncio-protocol asyncio-example-subprocess-proto11784416
Ref: 383e11784416
Ref: library/asyncio-protocol loop-subprocess-exec-and-subprocessprotocol11784416
Ref: 38e711784416
Node: Policies11786727
Ref: library/asyncio-policy doc11786858
Ref: 38e811786858
Ref: library/asyncio-policy asyncio-policies11786858
Ref: 386611786858
Ref: library/asyncio-policy policies11786858
Ref: 38e911786858
Ref: library/asyncio-policy translation-repo11786858
Ref: 38ea11786858
Node: Getting and Setting the Policy11788024
Ref: library/asyncio-policy asyncio-policy-get-set11788122
Ref: 38eb11788122
Ref: library/asyncio-policy getting-and-setting-the-policy11788122
Ref: 38ef11788122
Ref: library/asyncio-policy asyncio get_event_loop_policy11788295
Ref: 31211788295
Ref: library/asyncio-policy asyncio set_event_loop_policy11788530
Ref: 31311788530
Node: Policy Objects11788852
Ref: library/asyncio-policy asyncio-policy-objects11788974
Ref: 38ee11788974
Ref: library/asyncio-policy policy-objects11788974
Ref: 38f011788974
Ref: library/asyncio-policy asyncio AbstractEventLoopPolicy11789093
Ref: 30e11789093
Ref: library/asyncio-policy asyncio AbstractEventLoopPolicy get_event_loop11789189
Ref: 38f111789189
Ref: library/asyncio-policy asyncio AbstractEventLoopPolicy set_event_loop11789482
Ref: 38f211789482
Ref: library/asyncio-policy asyncio AbstractEventLoopPolicy new_event_loop11789587
Ref: 38f311789587
Ref: library/asyncio-policy asyncio-policy-builtin11789870
Ref: 38ec11789870
Ref: library/asyncio-policy asyncio DefaultEventLoopPolicy11789923
Ref: 30f11789923
Ref: library/asyncio-policy asyncio WindowsSelectorEventLoopPolicy11790656
Ref: 31011790656
Ref: library/asyncio-policy asyncio WindowsProactorEventLoopPolicy11791015
Ref: 31111791015
Node: Custom Policies11791374
Ref: library/asyncio-policy asyncio-custom-policies11791457
Ref: 38ed11791457
Ref: library/asyncio-policy custom-policies11791457
Ref: 38f411791457
Node: Platform Support11792065
Ref: library/asyncio-platforms doc11792181
Ref: 38f511792181
Ref: library/asyncio-platforms asyncio-platform-support11792181
Ref: 388811792181
Ref: library/asyncio-platforms platform-support11792181
Ref: 38f611792181
Ref: library/asyncio-platforms translation-repo11792181
Ref: 38f711792181
Node: All Platforms11792493
Ref: library/asyncio-platforms all-platforms11792579
Ref: 38f811792579
Node: Windows<83>11792743
Ref: library/asyncio-platforms windows11792847
Ref: 38f911792847
Ref: Windows<83>-Footnote-111794697
Ref: Windows<83>-Footnote-211794781
Ref: Windows<83>-Footnote-311794864
Ref: Windows<83>-Footnote-411794946
Node: Subprocess Support on Windows11795011
Ref: library/asyncio-platforms asyncio-windows-subprocess11795088
Ref: 382b11795088
Ref: library/asyncio-platforms subprocess-support-on-windows11795088
Ref: 38fb11795088
Node: macOS<51>11795308
Ref: library/asyncio-platforms macos11795390
Ref: 38fc11795390
Node: Extending11796021
Ref: library/asyncio-extending doc11796149
Ref: 38fe11796149
Ref: library/asyncio-extending extending11796149
Ref: 38ff11796149
Ref: library/asyncio-extending translation-repo11796149
Ref: 390011796149
Node: Writing a Custom Event Loop11796629
Ref: library/asyncio-extending writing-a-custom-event-loop11796747
Ref: 390111796747
Node: Future and Task private constructors11797466
Ref: library/asyncio-extending future-and-task-private-constructors11797614
Ref: 390211797614
Ref: library/asyncio-extending asyncio Future __init__11798178
Ref: 390311798178
Ref: library/asyncio-extending asyncio Task __init__11798312
Ref: 390411798312
Node: Task lifetime support11798627
Ref: library/asyncio-extending task-lifetime-support11798739
Ref: 390511798739
Ref: library/asyncio-extending asyncio _register_task11798975
Ref: 390611798975
Ref: library/asyncio-extending asyncio _unregister_task11799122
Ref: 390711799122
Ref: library/asyncio-extending asyncio _enter_task11799299
Ref: 390811799299
Ref: library/asyncio-extending asyncio _leave_task11799557
Ref: 390911799557
Node: High-level API Index11799781
Ref: library/asyncio-api-index doc11799912
Ref: a7b11799912
Ref: library/asyncio-api-index high-level-api-index11799912
Ref: 390a11799912
Ref: library/asyncio-api-index translation-repo11799912
Ref: 390b11799912
Node: Tasks11800190
Ref: library/asyncio-api-index tasks11800270
Ref: 390c11800270
Node: Queues<2>11804410
Ref: library/asyncio-api-index queues11804514
Ref: 390d11804514
Node: Subprocesses<2>11805333
Ref: library/asyncio-api-index subprocesses11805442
Ref: 390e11805442
Node: Streams<2>11806004
Ref: library/asyncio-api-index streams11806119
Ref: 390f11806119
Node: Synchronization11807554
Ref: library/asyncio-api-index synchronization11807668
Ref: 391011807668
Node: Exceptions<16>11809031
Ref: library/asyncio-api-index exceptions11809126
Ref: 391111809126
Node: Low-level API Index11809876
Ref: library/asyncio-llapi-index doc11810021
Ref: 391211810021
Ref: library/asyncio-llapi-index low-level-api-index11810021
Ref: 391311810021
Ref: library/asyncio-llapi-index translation-repo11810021
Ref: 391411810021
Node: Obtaining the Event Loop11810293
Ref: library/asyncio-llapi-index obtaining-the-event-loop11810403
Ref: 391511810403
Node: Event Loop Methods<2>11811532
Ref: library/asyncio-llapi-index event-loop-methods11811664
Ref: 391611811664
Node: Transports<2>11824016
Ref: library/asyncio-llapi-index transports11824136
Ref: 391711824136
Node: Protocols<3>11830181
Ref: library/asyncio-llapi-index protocols11830299
Ref: 391811830299
Node: Event Loop Policies11834040
Ref: library/asyncio-llapi-index event-loop-policies11834136
Ref: 391911834136
Node: Developing with asyncio11834965
Ref: library/asyncio-dev doc11835081
Ref: 391a11835081
Ref: library/asyncio-dev asyncio-dev11835081
Ref: 391b11835081
Ref: library/asyncio-dev developing-with-asyncio11835081
Ref: 391c11835081
Ref: library/asyncio-dev translation-repo11835081
Ref: 391d11835081
Node: Debug Mode11835490
Ref: library/asyncio-dev asyncio-debug-mode11835599
Ref: 212311835599
Ref: library/asyncio-dev debug-mode11835599
Ref: 391e11835599
Node: Concurrency and Multithreading11837095
Ref: library/asyncio-dev asyncio-multithreading11837234
Ref: 37ce11837234
Ref: library/asyncio-dev concurrency-and-multithreading11837234
Ref: 392011837234
Node: Running Blocking Code11839556
Ref: library/asyncio-dev asyncio-handle-blocking11839695
Ref: 392111839695
Ref: library/asyncio-dev running-blocking-code11839695
Ref: 392211839695
Node: Logging<3>11840229
Ref: library/asyncio-dev asyncio-logger11840369
Ref: 391f11840369
Ref: library/asyncio-dev logging11840369
Ref: 392311840369
Node: Detect never-awaited coroutines11840848
Ref: library/asyncio-dev asyncio-coroutine-not-scheduled11841000
Ref: 392511841000
Ref: library/asyncio-dev detect-never-awaited-coroutines11841000
Ref: 392611841000
Node: Detect never-retrieved exceptions11842009
Ref: library/asyncio-dev detect-never-retrieved-exceptions11842142
Ref: 392711842142
Ref: Detect never-retrieved exceptions-Footnote-111843751
Node: socket — Low-level networking interface11843816
Ref: library/socket doc11844023
Ref: 392811844023
Ref: library/socket module-socket11844023
Ref: d111844023
Ref: library/socket socket-low-level-networking-interface11844023
Ref: 392911844023
Ref: library/socket translation-repo11844023
Ref: 392a11844023
Ref: socket — Low-level networking interface-Footnote-111845505
Node: Socket families11845571
Ref: library/socket socket-families11845688
Ref: 392b11845688
Ref: library/socket host-port11846894
Ref: 392c11846894
Ref: Socket families-Footnote-111858410
Ref: Socket families-Footnote-211858452
Node: Module contents11858497
Ref: library/socket module-contents11858637
Ref: 393811858637
Node: Exceptions<17>11858844
Ref: library/socket exceptions11858931
Ref: 393911858931
Ref: library/socket socket error11858972
Ref: 125811858972
Ref: library/socket socket herror11859164
Ref: 393a11859164
Ref: library/socket socket gaierror11859794
Ref: 1aac11859794
Ref: library/socket socket timeout11860404
Ref: a3711860404
Ref: Exceptions<17>-Footnote-111861053
Node: Constants<8>11861095
Ref: library/socket constants11861203
Ref: 393c11861203
Ref: library/socket socket AF_UNIX11861378
Ref: 1b9811861378
Ref: library/socket socket AF_INET11861403
Ref: 1b9511861403
Ref: library/socket socket AF_INET611861428
Ref: 1b9611861428
Ref: library/socket socket AF_UNSPEC11861742
Ref: 388011861742
Ref: library/socket socket SOCK_STREAM11861953
Ref: 14fb11861953
Ref: library/socket socket SOCK_DGRAM11861982
Ref: 14fa11861982
Ref: library/socket socket SOCK_RAW11862010
Ref: 393d11862010
Ref: library/socket socket SOCK_RDM11862036
Ref: 393e11862036
Ref: library/socket socket SOCK_SEQPACKET11862062
Ref: 393f11862062
Ref: library/socket socket SOCK_CLOEXEC11862363
Ref: e0711862363
Ref: library/socket socket SOCK_NONBLOCK11862393
Ref: e0611862393
Ref: library/socket socket-unix-constants11862814
Ref: d6e11862814
Ref: library/socket socket SOMAXCONN11862829
Ref: 106111862829
Ref: library/socket socket AF_CAN11865791
Ref: 392d11865791
Ref: library/socket socket PF_CAN11865815
Ref: 394011865815
Ref: library/socket socket CAN_BCM11866244
Ref: 11a511866244
Ref: library/socket socket CAN_RAW_FD_FRAMES11866669
Ref: 10cc11866669
Ref: library/socket socket CAN_RAW_JOIN_FILTERS11867085
Ref: b2d11867085
Ref: library/socket socket CAN_ISOTP11867387
Ref: 392e11867387
Ref: library/socket socket CAN_J193911867639
Ref: b2e11867639
Ref: library/socket socket AF_DIVERT11867875
Ref: 394111867875
Ref: library/socket socket PF_DIVERT11867902
Ref: 394211867902
Ref: library/socket socket AF_PACKET11868129
Ref: 393411868129
Ref: library/socket socket PF_PACKET11868156
Ref: 394311868156
Ref: library/socket socket ETH_P_ALL11868371
Ref: 1b0b11868371
Ref: library/socket socket AF_RDS11868721
Ref: 394411868721
Ref: library/socket socket PF_RDS11868745
Ref: 394511868745
Ref: library/socket socket SOL_RDS11868769
Ref: 394611868769
Ref: library/socket socket SIO_RCVALL11869010
Ref: 394711869010
Ref: library/socket socket SIO_KEEPALIVE_VALS11869038
Ref: 394811869038
Ref: library/socket socket SIO_LOOPBACK_FAST_PATH11869074
Ref: ed111869074
Ref: library/socket socket AF_ALG11869498
Ref: ed411869498
Ref: library/socket socket SOL_ALG11869522
Ref: 394911869522
Ref: library/socket socket AF_VSOCK11869690
Ref: d6f11869690
Ref: library/socket socket IOCTL_VM_SOCKETS_GET_LOCAL_CID11869716
Ref: 394a11869716
Ref: library/socket socket AF_LINK11869929
Ref: 11a611869929
Ref: library/socket socket has_ipv611870028
Ref: 394b11870028
Ref: library/socket socket AF_BLUETOOTH11870160
Ref: 1b9711870160
Ref: library/socket socket BTPROTO_L2CAP11870190
Ref: 28311870190
Ref: library/socket socket BTPROTO_RFCOMM11870221
Ref: 393211870221
Ref: library/socket socket BTPROTO_HCI11870253
Ref: 28111870253
Ref: library/socket socket BTPROTO_SCO11870282
Ref: 28211870282
Ref: library/socket socket BDADDR_ANY11870370
Ref: 394c11870370
Ref: library/socket socket BDADDR_LOCAL11870398
Ref: 394d11870398
Ref: library/socket socket BDADDR_BREDR11870673
Ref: 392f11870673
Ref: library/socket socket BDADDR_LE_PUBLIC11870703
Ref: 393011870703
Ref: library/socket socket BDADDR_LE_RANDOM11870737
Ref: 393111870737
Ref: library/socket socket SOL_RFCOMM11870975
Ref: 394e11870975
Ref: library/socket socket SOL_L2CAP11871003
Ref: 394f11871003
Ref: library/socket socket SOL_HCI11871030
Ref: 395011871030
Ref: library/socket socket SOL_SCO11871055
Ref: 395111871055
Ref: library/socket socket SOL_BLUETOOTH11871080
Ref: 395211871080
Ref: library/socket socket L2CAP_LM11871410
Ref: 395311871410
Ref: library/socket socket HCI_FILTER11871945
Ref: 395411871945
Ref: library/socket socket HCI_TIME_STAMP11871973
Ref: 395511871973
Ref: library/socket socket HCI_DATA_DIR11872005
Ref: 395611872005
Ref: library/socket socket SO_HCI_EVT_FILTER11872035
Ref: 395711872035
Ref: library/socket socket SO_HCI_PKT_FILTER11872070
Ref: 395811872070
Ref: library/socket socket HCI_DEV_NONE11872429
Ref: 395911872429
Ref: library/socket socket HCI_CHANNEL_RAW11872647
Ref: 393311872647
Ref: library/socket socket HCI_CHANNEL_USER11872680
Ref: 395a11872680
Ref: library/socket socket HCI_CHANNEL_MONITOR11872714
Ref: 395b11872714
Ref: library/socket socket HCI_CHANNEL_CONTROL11872751
Ref: 395c11872751
Ref: library/socket socket HCI_CHANNEL_LOGGING11872788
Ref: 395d11872788
Ref: library/socket socket AF_QIPCRTR11872985
Ref: 393511872985
Ref: library/socket socket SCM_CREDS211873181
Ref: 395e11873181
Ref: library/socket socket LOCAL_CREDS11873209
Ref: 395f11873209
Ref: library/socket socket LOCAL_CREDS_PERSISTENT11873238
Ref: 396011873238
Ref: library/socket socket SO_INCOMING_CPU11873676
Ref: 396111873676
Ref: library/socket socket SO_REUSEPORT_LB11873882
Ref: 18bc11873882
Ref: library/socket socket AF_HYPERV11874091
Ref: 393611874091
Ref: library/socket socket HV_PROTOCOL_RAW11874118
Ref: 396211874118
Ref: library/socket socket HVSOCKET_CONNECT_TIMEOUT11874151
Ref: 396311874151
Ref: library/socket socket HVSOCKET_CONNECT_TIMEOUT_MAX11874193
Ref: 396411874193
Ref: library/socket socket HVSOCKET_CONNECTED_SUSPEND11874239
Ref: 396511874239
Ref: library/socket socket HVSOCKET_ADDRESS_FLAG_PASSTHRU11874283
Ref: 396611874283
Ref: library/socket socket HV_GUID_ZERO11874331
Ref: 396711874331
Ref: library/socket socket HV_GUID_WILDCARD11874361
Ref: 396811874361
Ref: library/socket socket HV_GUID_BROADCAST11874395
Ref: 396911874395
Ref: library/socket socket HV_GUID_CHILDREN11874430
Ref: 396a11874430
Ref: library/socket socket HV_GUID_LOOPBACK11874464
Ref: 396b11874464
Ref: library/socket socket HV_GUID_PARENT11874498
Ref: 396c11874498
Ref: library/socket socket-ethernet-types11874682
Ref: 1b0c11874682
Ref: library/socket socket ETHERTYPE_ARP11874682
Ref: 396d11874682
Ref: library/socket socket ETHERTYPE_IP11874713
Ref: 396e11874713
Ref: library/socket socket ETHERTYPE_IPV611874743
Ref: 396f11874743
Ref: library/socket socket ETHERTYPE_VLAN11874775
Ref: 397011874775
Ref: library/socket socket SHUT_RD11874942
Ref: 397111874942
Ref: library/socket socket SHUT_WR11874967
Ref: 397211874967
Ref: library/socket socket SHUT_RDWR11874992
Ref: 397311874992
Ref: Constants<8>-Footnote-111875192
Ref: Constants<8>-Footnote-211875244
Ref: Constants<8>-Footnote-311875290
Node: Functions<7>11875370
Ref: library/socket functions11875455
Ref: 397511875455
Node: Creating sockets11875564
Ref: library/socket creating-sockets11875656
Ref: 397611875656
Ref: library/socket socket socket11875773
Ref: fa311875773
Ref: library/socket socket socketpair11878394
Ref: df211878394
Ref: library/socket socket create_connection11879147
Ref: 88311879147
Ref: library/socket socket create_server11880665
Ref: c2211880665
Ref: library/socket socket has_dualstack_ipv611882495
Ref: c2311882495
Ref: library/socket socket fromfd11882692
Ref: 397811882692
Ref: library/socket socket fromshare11883592
Ref: e0311883592
Ref: library/socket socket SocketType11883848
Ref: 397a11883848
Node: Other functions<2>11884001
Ref: library/socket other-functions11884093
Ref: 397b11884093
Ref: library/socket socket close11884220
Ref: d6c11884220
Ref: library/socket socket getaddrinfo11884494
Ref: 1aab11884494
Ref: library/socket socket getfqdn11888599
Ref: 1ad511888599
Ref: library/socket socket gethostbyname11889216
Ref: 397c11889216
Ref: library/socket socket gethostbyname_ex11889860
Ref: 1c6d11889860
Ref: library/socket socket gethostname11890650
Ref: 300b11890650
Ref: library/socket socket gethostbyaddr11891080
Ref: 1c6c11891080
Ref: library/socket socket getnameinfo11891821
Ref: 1a2211891821
Ref: library/socket socket getprotobyname11892593
Ref: 397d11892593
Ref: library/socket socket getservbyname11893088
Ref: 397e11893088
Ref: library/socket socket getservbyport11893543
Ref: 397f11893543
Ref: library/socket socket ntohl11893984
Ref: 398011893984
Ref: library/socket socket ntohs11894241
Ref: a8211894241
Ref: library/socket socket htonl11894622
Ref: 398111894622
Ref: library/socket socket htons11894879
Ref: a8111894879
Ref: library/socket socket inet_aton11895260
Ref: b5c11895260
Ref: library/socket socket inet_ntoa11896191
Ref: 398211896191
Ref: library/socket socket inet_pton11897019
Ref: b5d11897019
Ref: library/socket socket inet_ntop11897813
Ref: 11a711897813
Ref: library/socket socket CMSG_LEN11898809
Ref: 1e0011898809
Ref: library/socket socket CMSG_SPACE11899491
Ref: 1dff11899491
Ref: library/socket socket getdefaulttimeout11900392
Ref: 397911900392
Ref: library/socket socket setdefaulttimeout11900670
Ref: 393b11900670
Ref: library/socket socket sethostname11900958
Ref: 134311900958
Ref: library/socket socket if_nameindex11901305
Ref: c2411901305
Ref: library/socket socket if_nametoindex11902112
Ref: c2511902112
Ref: library/socket socket if_indextoname11902581
Ref: c2611902581
Ref: library/socket socket send_fds11903052
Ref: b2f11903052
Ref: library/socket socket recv_fds11903527
Ref: b3011903527
Ref: Other functions<2>-Footnote-111904112
Ref: Other functions<2>-Footnote-211904165
Ref: Other functions<2>-Footnote-311904216
Ref: Other functions<2>-Footnote-411904260
Node: Socket Objects11904319
Ref: library/socket id111904468
Ref: 398311904468
Ref: library/socket socket-objects11904468
Ref: 397711904468
Ref: library/socket socket socket accept11904826
Ref: fa411904826
Ref: library/socket socket socket bind11905608
Ref: 174111905608
Ref: library/socket socket socket close11905952
Ref: f4111905952
Ref: library/socket socket socket connect11906953
Ref: fa511906953
Ref: library/socket socket socket connect_ex11908072
Ref: 174011908072
Ref: library/socket socket socket detach11908693
Ref: 142411908693
Ref: library/socket socket socket dup11908936
Ref: 398411908936
Ref: library/socket socket socket fileno11909167
Ref: 398511909167
Ref: library/socket socket socket get_inheritable11909528
Ref: 110311909528
Ref: library/socket socket socket getpeername11909793
Ref: 38bf11909793
Ref: library/socket socket socket getsockname11910132
Ref: 28411910132
Ref: library/socket socket socket getsockopt11910381
Ref: ed211910381
Ref: library/socket socket socket getblocking11911133
Ref: d6b11911133
Ref: library/socket socket socket gettimeout11911357
Ref: 398611911357
Ref: library/socket socket socket ioctl11911604
Ref: ed011911604
Ref: library/socket socket socket listen11912263
Ref: 106011912263
Ref: library/socket socket socket makefile11912742
Ref: 13a711912742
Ref: library/socket socket socket recv11913890
Ref: fa611913890
Ref: library/socket socket socket recvfrom11914607
Ref: fa711914607
Ref: library/socket socket socket recvmsg11915564
Ref: fa811915564
Ref: library/socket socket socket recvmsg_into11919493
Ref: 134211919493
Ref: library/socket socket socket recvfrom_into11921133
Ref: 152611921133
Ref: library/socket socket socket recv_into11921671
Ref: 152511921671
Ref: library/socket socket socket send11922122
Ref: fa911922122
Ref: library/socket socket socket sendall11922946
Ref: faa11922946
Ref: library/socket socket socket sendto11923938
Ref: fab11923938
Ref: library/socket socket socket sendmsg11924780
Ref: 6a211924780
Ref: library/socket socket socket sendmsg_afalg11926964
Ref: ed511926964
Ref: library/socket socket socket sendfile11927304
Ref: 105f11927304
Ref: library/socket socket socket set_inheritable11928211
Ref: 110411928211
Ref: library/socket socket socket setblocking11928394
Ref: 302111928394
Ref: library/socket socket socket settimeout11928971
Ref: 393711928971
Ref: library/socket socket socket setsockopt11929712
Ref: ed311929712
Ref: library/socket socket socket shutdown11930795
Ref: 397411930795
Ref: library/socket socket socket share11931152
Ref: e0411931152
Ref: library/socket socket socket family11932020
Ref: 398911932020
Ref: library/socket socket socket type11932075
Ref: e0811932075
Ref: library/socket socket socket proto11932126
Ref: 398a11932126
Ref: Socket Objects-Footnote-111932218
Ref: Socket Objects-Footnote-211932260
Ref: Socket Objects-Footnote-311932302
Ref: Socket Objects-Footnote-411932352
Ref: Socket Objects-Footnote-511932426
Ref: Socket Objects-Footnote-611932470
Ref: Socket Objects-Footnote-711932512
Ref: Socket Objects-Footnote-811932556
Ref: Socket Objects-Footnote-911932598
Ref: Socket Objects-Footnote-1011932640
Ref: Socket Objects-Footnote-1111932685
Ref: Socket Objects-Footnote-1211932730
Ref: Socket Objects-Footnote-1311932773
Ref: Socket Objects-Footnote-1411932816
Ref: Socket Objects-Footnote-1511932859
Ref: Socket Objects-Footnote-1611932902
Node: Notes on socket timeouts11932953
Ref: library/socket notes-on-socket-timeouts11933097
Ref: 398b11933097
Ref: library/socket socket-timeouts11933097
Ref: 398811933097
Node: Timeouts and the connect method11934466
Ref: library/socket timeouts-and-the-connect-method11934597
Ref: 398c11934597
Node: Timeouts and the accept method11935072
Ref: library/socket timeouts-and-the-accept-method11935203
Ref: 398d11935203
Node: Example<7>11935944
Ref: library/socket example11936065
Ref: 398e11936065
Ref: library/socket socket-example11936065
Ref: 398f11936065
Ref: Example<7>-Footnote-111943806
Node: ssl — TLS/SSL wrapper for socket objects11943865
Ref: library/ssl doc11944081
Ref: 399011944081
Ref: library/ssl module-ssl11944081
Ref: d511944081
Ref: library/ssl ssl-tls-ssl-wrapper-for-socket-objects11944081
Ref: 399111944081
Ref: library/ssl translation-repo11944081
Ref: 399211944081
Ref: ssl — TLS/SSL wrapper for socket objects-Footnote-111947240
Ref: ssl — TLS/SSL wrapper for socket objects-Footnote-211947303
Node: Functions Constants and Exceptions11947345
Ref: library/ssl functions-constants-and-exceptions11947478
Ref: 399311947478
Node: Socket creation11947726
Ref: library/ssl socket-creation11947837
Ref: 399411947837
Node: Context creation11949365
Ref: library/ssl context-creation11949499
Ref: 399511949499
Ref: library/ssl ssl create_default_context11949641
Ref: 48011949641
Ref: Context creation-Footnote-111953678
Ref: Context creation-Footnote-211953737
Ref: Context creation-Footnote-311953782
Node: Exceptions<18>11953841
Ref: library/ssl exceptions11953977
Ref: 399a11953977
Ref: library/ssl ssl SSLError11954018
Ref: 148111954018
Ref: library/ssl ssl SSLError library11954598
Ref: 134f11954598
Ref: library/ssl ssl SSLError reason11954878
Ref: 135011954878
Ref: library/ssl ssl SSLZeroReturnError11955139
Ref: 399b11955139
Ref: library/ssl ssl SSLWantReadError11955436
Ref: 106b11955436
Ref: library/ssl ssl SSLWantWriteError11955746
Ref: 106c11955746
Ref: library/ssl ssl SSLSyscallError11956053
Ref: 399d11956053
Ref: library/ssl ssl SSLEOFError11956345
Ref: 1aa011956345
Ref: library/ssl ssl SSLCertVerificationError11956616
Ref: d7711956616
Ref: library/ssl ssl SSLCertVerificationError verify_code11956783
Ref: 399e11956783
Ref: library/ssl ssl SSLCertVerificationError verify_message11956887
Ref: 399f11956887
Ref: library/ssl ssl CertificateError11956985
Ref: 39a011956985
Node: Random generation11957189
Ref: library/ssl random-generation11957329
Ref: 39a111957329
Ref: library/ssl ssl RAND_bytes11957384
Ref: 74811957384
Ref: library/ssl ssl RAND_status11958069
Ref: 1c6611958069
Ref: library/ssl ssl RAND_add11958389
Ref: 39a211958389
Ref: Random generation-Footnote-111958839
Ref: Random generation-Footnote-211958933
Node: Certificate handling11958992
Ref: library/ssl certificate-handling11959130
Ref: 39a311959130
Ref: library/ssl ssl cert_time_to_seconds11959191
Ref: 106d11959191
Ref: library/ssl ssl get_server_certificate11960098
Ref: a3f11960098
Ref: library/ssl ssl DER_cert_to_PEM_cert11961287
Ref: 39a511961287
Ref: library/ssl ssl PEM_cert_to_DER_cert11961469
Ref: 39a611961469
Ref: library/ssl ssl get_default_verify_paths11961649
Ref: 11ac11961649
Ref: library/ssl ssl enum_certificates11962527
Ref: 11b711962527
Ref: library/ssl ssl enum_crls11963406
Ref: 11b811963406
Ref: Certificate handling-Footnote-111963975
Node: Constants<9>11964034
Ref: library/ssl constants11964146
Ref: 39a711964146
Ref: library/ssl ssl CERT_NONE11964312
Ref: 39a811964312
Ref: library/ssl ssl CERT_OPTIONAL11964861
Ref: 39a911964861
Ref: library/ssl ssl CERT_REQUIRED11965612
Ref: 399711965612
Ref: library/ssl ssl VerifyMode11966583
Ref: 39ab11966583
Ref: library/ssl ssl VERIFY_DEFAULT11966702
Ref: 11b111966702
Ref: library/ssl ssl VERIFY_CRL_CHECK_LEAF11966958
Ref: 11b211966958
Ref: library/ssl ssl VERIFY_CRL_CHECK_CHAIN11967407
Ref: 11b311967407
Ref: library/ssl ssl VERIFY_X509_STRICT11967616
Ref: 48211967616
Ref: library/ssl ssl VERIFY_ALLOW_PROXY_CERTS11967799
Ref: 1c7d11967799
Ref: library/ssl ssl VERIFY_X509_TRUSTED_FIRST11967978
Ref: 39ac11967978
Ref: library/ssl ssl VERIFY_X509_PARTIAL_CHAIN11968270
Ref: 48111968270
Ref: library/ssl ssl VerifyFlags11968705
Ref: 39ad11968705
Ref: library/ssl ssl PROTOCOL_TLS11968827
Ref: 399911968827
Ref: library/ssl ssl PROTOCOL_TLS_CLIENT11969321
Ref: a7411969321
Ref: library/ssl ssl PROTOCOL_TLS_SERVER11969634
Ref: a7511969634
Ref: library/ssl ssl PROTOCOL_SSLv2311969849
Ref: 39ae11969849
Ref: library/ssl ssl PROTOCOL_SSLv311970002
Ref: 39a411970002
Ref: library/ssl ssl PROTOCOL_TLSv111970586
Ref: 39af11970586
Ref: library/ssl ssl PROTOCOL_TLSv1_111970778
Ref: 11aa11970778
Ref: library/ssl ssl PROTOCOL_TLSv1_211971049
Ref: 11ab11971049
Ref: library/ssl ssl OP_ALL11971320
Ref: 39b011971320
Ref: library/ssl ssl OP_NO_SSLv211971579
Ref: a3c11971579
Ref: library/ssl ssl OP_NO_SSLv311971882
Ref: a3d11971882
Ref: library/ssl ssl OP_NO_TLSv111972185
Ref: 39b111972185
Ref: library/ssl ssl OP_NO_TLSv1_111972626
Ref: 39b211972626
Ref: library/ssl ssl OP_NO_TLSv1_211973015
Ref: 39b311973015
Ref: library/ssl ssl OP_NO_TLSv1_311973404
Ref: 1c4311973404
Ref: library/ssl ssl OP_NO_RENEGOTIATION11973992
Ref: 39b411973992
Ref: library/ssl ssl OP_CIPHER_SERVER_PREFERENCE11974275
Ref: 135111974275
Ref: library/ssl ssl OP_SINGLE_DH_USE11974508
Ref: 39b511974508
Ref: library/ssl ssl OP_SINGLE_ECDH_USE11974763
Ref: 39b611974763
Ref: library/ssl ssl OP_ENABLE_MIDDLEBOX_COMPAT11975022
Ref: 39b711975022
Ref: library/ssl ssl OP_NO_COMPRESSION11975301
Ref: 134e11975301
Ref: library/ssl ssl Options11975494
Ref: 39b811975494
Ref: library/ssl ssl OP_NO_TICKET11975580
Ref: 39b911975580
Ref: library/ssl ssl OP_IGNORE_UNEXPECTED_EOF11975696
Ref: a3a11975696
Ref: library/ssl ssl OP_ENABLE_KTLS11975884
Ref: 1af711975884
Ref: library/ssl ssl OP_LEGACY_SERVER_CONNECT11976594
Ref: 1ad911976594
Ref: library/ssl ssl HAS_ALPN11976754
Ref: 106811976754
Ref: library/ssl ssl HAS_NEVER_CHECK_COMMON_NAME11976963
Ref: 39ba11976963
Ref: library/ssl ssl HAS_ECDH11977201
Ref: 39bb11977201
Ref: library/ssl ssl HAS_SNI11977460
Ref: 39bc11977460
Ref: library/ssl ssl HAS_NPN11977643
Ref: 39bd11977643
Ref: library/ssl ssl HAS_SSLv211977996
Ref: 39be11977996
Ref: library/ssl ssl HAS_SSLv311978135
Ref: 39bf11978135
Ref: library/ssl ssl HAS_TLSv111978274
Ref: 39c011978274
Ref: library/ssl ssl HAS_TLSv1_111978413
Ref: d7e11978413
Ref: library/ssl ssl HAS_TLSv1_211978554
Ref: 39c111978554
Ref: library/ssl ssl HAS_TLSv1_311978695
Ref: 39c211978695
Ref: library/ssl ssl HAS_PSK11978836
Ref: 39c311978836
Ref: library/ssl ssl HAS_PHA11978956
Ref: 28611978956
Ref: library/ssl ssl CHANNEL_BINDING_TYPES11979076
Ref: 39c411979076
Ref: library/ssl ssl OPENSSL_VERSION11979297
Ref: 142611979297
Ref: library/ssl ssl OPENSSL_VERSION_INFO11979511
Ref: 142711979511
Ref: library/ssl ssl OPENSSL_VERSION_NUMBER11979739
Ref: 142811979739
Ref: library/ssl ssl ALERT_DESCRIPTION_HANDSHAKE_FAILURE11980010
Ref: 39c511980010
Ref: library/ssl ssl ALERT_DESCRIPTION_INTERNAL_ERROR11980060
Ref: 39c611980060
Ref: library/ssl ssl AlertDescription11980455
Ref: 39c711980455
Ref: library/ssl ssl Purpose SERVER_AUTH11980598
Ref: 11b511980598
Ref: library/ssl ssl Purpose CLIENT_AUTH11980914
Ref: 11b611980914
Ref: library/ssl ssl SSLErrorNumber11981230
Ref: 39c811981230
Ref: library/ssl ssl TLSVersion11981358
Ref: 39c911981358
Ref: library/ssl ssl TLSVersion MINIMUM_SUPPORTED11981576
Ref: 39ca11981576
Ref: library/ssl ssl TLSVersion MAXIMUM_SUPPORTED11981621
Ref: 39cb11981621
Ref: library/ssl ssl TLSVersion SSLv311981844
Ref: 39cc11981844
Ref: library/ssl ssl TLSVersion TLSv111981877
Ref: 39cd11981877
Ref: library/ssl ssl TLSVersion TLSv1_111981910
Ref: 39ce11981910
Ref: library/ssl ssl TLSVersion TLSv1_211981945
Ref: 39cf11981945
Ref: library/ssl ssl TLSVersion TLSv1_311981980
Ref: 39d011981980
Ref: Constants<9>-Footnote-111982251
Ref: Constants<9>-Footnote-211982310
Ref: Constants<9>-Footnote-311982369
Ref: Constants<9>-Footnote-411982447
Ref: Constants<9>-Footnote-511982506
Node: SSL Sockets11982599
Ref: library/ssl ssl-sockets11982753
Ref: 39d111982753
Ref: library/ssl ssl SSLSocket11982796
Ref: ae911982796
Ref: library/ssl ssl SSLSocket read11985256
Ref: 107011985256
Ref: library/ssl ssl SSLSocket write11986088
Ref: 107111986088
Ref: library/ssl ssl SSLSocket do_handshake11987336
Ref: 106f11987336
Ref: library/ssl ssl SSLSocket getpeercert11988284
Ref: 11ba11988284
Ref: library/ssl ssl SSLSocket get_verified_chain11991831
Ref: 194411991831
Ref: library/ssl ssl SSLSocket get_unverified_chain11992140
Ref: 194511992140
Ref: library/ssl ssl SSLSocket cipher11992334
Ref: 38c011992334
Ref: library/ssl ssl SSLSocket shared_ciphers11992618
Ref: 106e11992618
Ref: library/ssl ssl SSLSocket compression11993098
Ref: 134d11993098
Ref: library/ssl ssl SSLSocket get_channel_binding11993446
Ref: 134c11993446
Ref: library/ssl ssl SSLSocket selected_alpn_protocol11994081
Ref: 106711994081
Ref: library/ssl ssl SSLSocket selected_npn_protocol11994495
Ref: a7611994495
Ref: library/ssl ssl SSLSocket unwrap11994920
Ref: 39d211994920
Ref: library/ssl ssl SSLSocket verify_client_post_handshake11995343
Ref: c2911995343
Ref: library/ssl ssl SSLSocket version11996224
Ref: 106a11996224
Ref: library/ssl ssl SSLSocket pending11996637
Ref: 39d411996637
Ref: library/ssl ssl SSLSocket context11996775
Ref: 39d311996775
Ref: library/ssl ssl SSLSocket server_side11996905
Ref: 39d511996905
Ref: library/ssl ssl SSLSocket server_hostname11997077
Ref: d7a11997077
Ref: library/ssl ssl SSLSocket session11997593
Ref: 192511997593
Ref: library/ssl ssl SSLSocket session_reused11997952
Ref: 39d611997952
Ref: SSL Sockets-Footnote-111998057
Ref: SSL Sockets-Footnote-211998116
Node: SSL Contexts11998175
Ref: library/ssl ssl-contexts11998307
Ref: 39d711998307
Ref: library/ssl ssl SSLContext11998653
Ref: 35711998653
Ref: library/ssl ssl SSLContext cert_store_stats12003634
Ref: 11ae12003634
Ref: library/ssl ssl SSLContext load_cert_chain12004040
Ref: 59812004040
Ref: library/ssl ssl SSLContext load_default_certs12005669
Ref: 11b412005669
Ref: library/ssl ssl SSLContext load_verify_locations12006494
Ref: 10f012006494
Ref: library/ssl ssl SSLContext get_ca_certs12007828
Ref: 11af12007828
Ref: library/ssl ssl SSLContext get_ciphers12008464
Ref: edc12008464
Ref: library/ssl ssl SSLContext set_default_verify_paths12009767
Ref: 11ad12009767
Ref: library/ssl ssl SSLContext set_ciphers12010234
Ref: 39d912010234
Ref: library/ssl ssl SSLContext set_alpn_protocols12010837
Ref: 106612010837
Ref: library/ssl ssl SSLContext set_npn_protocols12011482
Ref: 35812011482
Ref: library/ssl ssl SSLContext sni_callback12012225
Ref: 1c7712012225
Ref: library/ssl ssl SSLContext set_servername_callback12014867
Ref: 11b912014867
Ref: library/ssl ssl SSLContext load_dh_params12015541
Ref: 134a12015541
Ref: library/ssl ssl SSLContext set_ecdh_curve12016089
Ref: 134b12016089
Ref: library/ssl ssl SSLContext wrap_socket12016825
Ref: 74912016825
Ref: library/ssl ssl SSLContext sslsocket_class12019746
Ref: 39da12019746
Ref: library/ssl ssl SSLContext wrap_bio12020063
Ref: d7d12020063
Ref: library/ssl ssl SSLContext sslobject_class12020812
Ref: 39db12020812
Ref: library/ssl ssl SSLContext session_stats12021107
Ref: 39dc12021107
Ref: library/ssl ssl SSLContext check_hostname12021572
Ref: 39aa12021572
Ref: library/ssl ssl SSLContext keylog_filename12023105
Ref: 399812023105
Ref: library/ssl ssl SSLContext maximum_version12023551
Ref: a7312023551
Ref: library/ssl ssl SSLContext minimum_version12024409
Ref: a7212024409
Ref: library/ssl ssl SSLContext num_tickets12024622
Ref: 39dd12024622
Ref: library/ssl ssl SSLContext options12024855
Ref: a3b12024855
Ref: library/ssl ssl SSLContext post_handshake_auth12025591
Ref: c2812025591
Ref: library/ssl ssl SSLContext protocol12026408
Ref: 39de12026408
Ref: library/ssl ssl SSLContext hostname_checks_common_name12026544
Ref: d7812026544
Ref: library/ssl ssl SSLContext security_level12026984
Ref: 39df12026984
Ref: library/ssl ssl SSLContext verify_flags12027159
Ref: 11b012027159
Ref: library/ssl ssl SSLContext verify_mode12027702
Ref: 399612027702
Ref: library/ssl ssl SSLContext set_psk_client_callback12028177
Ref: 39e012028177
Ref: library/ssl ssl SSLContext set_psk_server_callback12030178
Ref: 39e112030178
Ref: SSL Contexts-Footnote-112032062
Ref: SSL Contexts-Footnote-212032216
Ref: SSL Contexts-Footnote-312032303
Ref: SSL Contexts-Footnote-412032390
Ref: SSL Contexts-Footnote-512032544
Ref: SSL Contexts-Footnote-612032631
Ref: SSL Contexts-Footnote-712032718
Ref: SSL Contexts-Footnote-812032795
Ref: SSL Contexts-Footnote-912032849
Ref: SSL Contexts-Footnote-1012032908
Ref: SSL Contexts-Footnote-1112032987
Ref: SSL Contexts-Footnote-1212033047
Ref: SSL Contexts-Footnote-1312033124
Ref: SSL Contexts-Footnote-1412033190
Node: Certificates12033264
Ref: library/ssl certificates12033397
Ref: 39e212033397
Ref: library/ssl ssl-certificates12033397
Ref: 39d812033397
Ref: Certificates-Footnote-112035740
Node: Certificate chains12035799
Ref: library/ssl certificate-chains12035890
Ref: 39e312035890
Node: CA certificates12037159
Ref: library/ssl ca-certificates12037287
Ref: 39e412037287
Node: Combined key and certificate12037876
Ref: library/ssl combined-key-and-certificate12038010
Ref: 39e512038010
Node: Self-signed certificates12038626
Ref: library/ssl self-signed-certificates12038736
Ref: 39e612038736
Node: Examples<21>12040434
Ref: library/ssl examples12040584
Ref: 39e712040584
Node: Testing for SSL support12040713
Ref: library/ssl testing-for-ssl-support12040815
Ref: 39e812040815
Node: Client-side operation12041129
Ref: library/ssl client-side-operation12041261
Ref: 39e912041261
Node: Server-side operation12046002
Ref: library/ssl server-side-operation12046102
Ref: 39ea12046102
Node: Notes on non-blocking sockets12048111
Ref: library/ssl notes-on-non-blocking-sockets12048270
Ref: 39eb12048270
Ref: library/ssl ssl-nonblocking12048270
Ref: 399c12048270
Node: Memory BIO Support<2>12051197
Ref: library/ssl memory-bio-support12051355
Ref: 39ec12051355
Ref: library/ssl ssl SSLObject12052471
Ref: d7c12052471
Ref: library/ssl ssl MemoryBIO12056148
Ref: 106412056148
Ref: library/ssl ssl MemoryBIO pending12056277
Ref: 39ed12056277
Ref: library/ssl ssl MemoryBIO eof12056376
Ref: 39ee12056376
Ref: library/ssl ssl MemoryBIO read12056506
Ref: 39ef12056506
Ref: library/ssl ssl MemoryBIO write12056667
Ref: 39f012056667
Ref: library/ssl ssl MemoryBIO write_eof12056952
Ref: 39f112056952
Node: SSL session12057244
Ref: library/ssl ssl-session12057399
Ref: 39f212057399
Ref: library/ssl ssl SSLSession12057467
Ref: edb12057467
Ref: library/ssl ssl SSLSession id12057545
Ref: 39f312057545
Ref: library/ssl ssl SSLSession time12057569
Ref: 39f412057569
Ref: library/ssl ssl SSLSession timeout12057595
Ref: 39f512057595
Ref: library/ssl ssl SSLSession ticket_lifetime_hint12057624
Ref: 39f612057624
Ref: library/ssl ssl SSLSession has_ticket12057666
Ref: 39f712057666
Node: Security considerations<2>12057698
Ref: library/ssl security-considerations12057839
Ref: 39f812057839
Ref: library/ssl ssl-security12057839
Ref: 387b12057839
Node: Best defaults12057977
Ref: library/ssl best-defaults12058077
Ref: 39f912058077
Node: Manual settings12059238
Ref: library/ssl manual-settings12059363
Ref: 39fa12059363
Node: Verifying certificates12059496
Ref: library/ssl verifying-certificates12059596
Ref: 39fb12059596
Node: Protocol versions12060795
Ref: library/ssl protocol-versions12060920
Ref: 39fc12060920
Node: Cipher selection12061744
Ref: library/ssl cipher-selection12061838
Ref: 39fd12061838
Ref: Cipher selection-Footnote-112062494
Node: Multi-processing12062566
Ref: library/ssl multi-processing12062669
Ref: 39fe12062669
Node: TLS 1 312063192
Ref: library/ssl ssl-tlsv1-312063313
Ref: d7b12063313
Ref: library/ssl tls-1-312063313
Ref: 39ff12063313
Ref: TLS 1 3-Footnote-112065483
Ref: TLS 1 3-Footnote-212065549
Ref: TLS 1 3-Footnote-312065608
Ref: TLS 1 3-Footnote-412065667
Ref: TLS 1 3-Footnote-512065726
Ref: TLS 1 3-Footnote-612065785
Ref: TLS 1 3-Footnote-712065844
Ref: TLS 1 3-Footnote-812065920
Ref: TLS 1 3-Footnote-912065979
Node: select — Waiting for I/O completion12066037
Ref: library/select doc12066253
Ref: 3a0012066253
Ref: library/select module-select12066253
Ref: c612066253
Ref: library/select select-waiting-for-i-o-completion12066253
Ref: 3a0112066253
Ref: library/select translation-repo12066253
Ref: 3a0212066253
Ref: library/select select error12067424
Ref: 125912067424
Ref: library/select select devpoll12067616
Ref: 119812067616
Ref: library/select select epoll12068344
Ref: 119612068344
Ref: library/select select poll12069852
Ref: 308e12069852
Ref: library/select select kqueue12070171
Ref: 1a2b12070171
Ref: library/select select kevent12070516
Ref: 3a0712070516
Ref: library/select select select12070793
Ref: fa212070793
Ref: library/select select PIPE_BUF12073084
Ref: 141212073084
Ref: select — Waiting for I/O completion-Footnote-112073769
Ref: select — Waiting for I/O completion-Footnote-212073811
Node: /dev/poll Polling Objects12073853
Ref: library/select dev-poll-polling-objects12074005
Ref: 3a0912074005
Ref: library/select devpoll-objects12074005
Ref: 3a0312074005
Ref: library/select select devpoll close12074371
Ref: 119a12074371
Ref: library/select select devpoll closed12074484
Ref: 119b12074484
Ref: library/select select devpoll fileno12074593
Ref: 119912074593
Ref: library/select select devpoll register12074715
Ref: 3a0a12074715
Ref: library/select select devpoll modify12075704
Ref: 3a0b12075704
Ref: library/select select devpoll unregister12075912
Ref: 3a0c12075912
Ref: library/select select devpoll poll12076269
Ref: f9e12076269
Ref: /dev/poll Polling Objects-Footnote-112077417
Node: Edge and Level Trigger Polling epoll Objects12077459
Ref: library/select edge-and-level-trigger-polling-epoll-objects12077635
Ref: 3a0d12077635
Ref: library/select epoll-objects12077635
Ref: 3a0412077635
Ref: library/select select epoll close12080769
Ref: 119712080769
Ref: library/select select epoll closed12080858
Ref: 3a0e12080858
Ref: library/select select epoll fileno12080935
Ref: 3a0f12080935
Ref: library/select select epoll fromfd12081023
Ref: 3a1012081023
Ref: library/select select epoll register12081113
Ref: 3a1112081113
Ref: library/select select epoll modify12081213
Ref: 3a1212081213
Ref: library/select select epoll unregister12081298
Ref: b5512081298
Ref: library/select select epoll poll12081496
Ref: f9f12081496
Ref: Edge and Level Trigger Polling epoll Objects-Footnote-112081903
Node: Polling Objects12081945
Ref: library/select poll-objects12082110
Ref: 3a0512082110
Ref: library/select polling-objects12082110
Ref: 3a1312082110
Ref: library/select select poll register12082685
Ref: 3a1412082685
Ref: library/select select poll modify12084662
Ref: 3a1512084662
Ref: library/select select poll unregister12084963
Ref: 3a1612084963
Ref: library/select select poll poll12085352
Ref: fa112085352
Ref: Polling Objects-Footnote-112086503
Node: Kqueue Objects12086545
Ref: library/select id112086680
Ref: 3a1712086680
Ref: library/select kqueue-objects12086680
Ref: 3a0612086680
Ref: library/select select kqueue close12086729
Ref: 3a1812086729
Ref: library/select select kqueue closed12086820
Ref: 3a1912086820
Ref: library/select select kqueue fileno12086899
Ref: 3a1a12086899
Ref: library/select select kqueue fromfd12086988
Ref: 3a1b12086988
Ref: library/select select kqueue control12087079
Ref: fa012087079
Ref: Kqueue Objects-Footnote-112087735
Node: Kevent Objects12087777
Ref: library/select id212087888
Ref: 3a1c12087888
Ref: library/select kevent-objects12087888
Ref: 3a0812087888
Ref: library/select select kevent ident12088003
Ref: 3a1d12088003
Ref: library/select select kevent filter12088305
Ref: 3a1e12088305
Ref: library/select select kevent flags12090084
Ref: 3a1f12090084
Ref: library/select select kevent fflags12091745
Ref: 3a2012091745
Ref: library/select select kevent data12095487
Ref: 3a2112095487
Ref: library/select select kevent udata12095543
Ref: 3a2212095543
Node: selectors — High-level I/O multiplexing12095598
Ref: library/selectors doc12095819
Ref: 3a2312095819
Ref: library/selectors module-selectors12095819
Ref: c712095819
Ref: library/selectors selectors-high-level-i-o-multiplexing12095819
Ref: 3a2412095819
Ref: library/selectors translation-repo12095819
Ref: 3a2512095819
Ref: selectors — High-level I/O multiplexing-Footnote-112096180
Node: Introduction<10>12096249
Ref: library/selectors introduction12096362
Ref: 3a2612096362
Node: Classes<3>12097703
Ref: library/selectors classes12097837
Ref: 3a2912097837
Ref: library/selectors selectors EVENT_READ12098414
Ref: 3a2a12098414
Ref: library/selectors selectors EVENT_WRITE12098503
Ref: 3a2b12098503
Ref: library/selectors selectors SelectorKey12098580
Ref: 3a2c12098580
Ref: library/selectors selectors SelectorKey fileobj12098859
Ref: 3a2d12098859
Ref: library/selectors selectors SelectorKey fd12098923
Ref: 3a2e12098923
Ref: library/selectors selectors SelectorKey events12098986
Ref: 3a2f12098986
Ref: library/selectors selectors SelectorKey data12099077
Ref: 3a3012099077
Ref: library/selectors selectors BaseSelector12099243
Ref: 3a2712099243
Ref: library/selectors selectors BaseSelector register12099920
Ref: 3a3112099920
Ref: library/selectors selectors BaseSelector unregister12100574
Ref: 3a3212100574
Ref: library/selectors selectors BaseSelector modify12101194
Ref: dd112101194
Ref: library/selectors selectors BaseSelector select12101790
Ref: 3a3312101790
Ref: library/selectors selectors BaseSelector close12103094
Ref: 3a3412103094
Ref: library/selectors selectors BaseSelector get_key12103312
Ref: 3a3512103312
Ref: library/selectors selectors BaseSelector get_map12103599
Ref: 3a3612103599
Ref: library/selectors selectors DefaultSelector12103867
Ref: 3a2812103867
Ref: library/selectors selectors SelectSelector12104076
Ref: 38fa12104076
Ref: library/selectors selectors PollSelector12104164
Ref: dd312104164
Ref: library/selectors selectors EpollSelector12104249
Ref: dd212104249
Ref: library/selectors selectors EpollSelector fileno12104336
Ref: 3a3712104336
Ref: library/selectors selectors DevpollSelector12104477
Ref: dd412104477
Ref: library/selectors selectors DevpollSelector fileno12104568
Ref: 3a3812104568
Ref: library/selectors selectors KqueueSelector12104739
Ref: 38fd12104739
Ref: library/selectors selectors KqueueSelector fileno12104828
Ref: 3a3912104828
Ref: Classes<3>-Footnote-112105006
Node: Examples<22>12105048
Ref: library/selectors examples12105157
Ref: 3a3a12105157
Node: signal — Set handlers for asynchronous events12106184
Ref: library/signal doc12106403
Ref: 3a3b12106403
Ref: library/signal module-signal12106403
Ref: cb12106403
Ref: library/signal signal-set-handlers-for-asynchronous-events12106403
Ref: 3a3c12106403
Ref: library/signal translation-repo12106403
Ref: 3a3d12106403
Ref: signal — Set handlers for asynchronous events-Footnote-112106880
Node: General rules12106946
Ref: library/signal general-rules12107070
Ref: 3a3e12107070
Node: Execution of Python signal handlers12108037
Ref: library/signal execution-of-python-signal-handlers12108150
Ref: 3a4012108150
Node: Signals and threads12109470
Ref: library/signal id112109583
Ref: 3a4212109583
Ref: library/signal signals-and-threads12109583
Ref: 3a4312109583
Node: Module contents<2>12110055
Ref: library/signal module-contents12110200
Ref: 3a4412110200
Ref: library/signal signal Signals12110819
Ref: 3a4812110819
Ref: library/signal signal Handlers12110966
Ref: 3a4912110966
Ref: library/signal signal Sigmasks12111130
Ref: 3a4a12111130
Ref: library/signal signal SIG_DFL12111533
Ref: 1b9a12111533
Ref: library/signal signal SIG_IGN12111872
Ref: 1b9912111872
Ref: library/signal signal SIGABRT12111993
Ref: 128412111993
Ref: library/signal signal SIGALRM12112062
Ref: 3a4c12112062
Ref: library/signal signal SIGBREAK12112170
Ref: 3a4d12112170
Ref: library/signal signal SIGBUS12112285
Ref: 128512112285
Ref: library/signal signal SIGCHLD12112386
Ref: 30c912112386
Ref: library/signal signal SIGCLD12112494
Ref: 3a4e12112494
Ref: library/signal signal SIGCONT12112599
Ref: 30d712112599
Ref: library/signal signal SIGFPE12112718
Ref: 128312112718
Ref: library/signal signal SIGHUP12112959
Ref: 3a4f12112959
Ref: library/signal signal SIGILL12113107
Ref: 128612113107
Ref: library/signal signal SIGINT12113159
Ref: 25312113159
Ref: library/signal signal SIGKILL12113289
Ref: d5212113289
Ref: library/signal signal SIGPIPE12113421
Ref: 3a3f12113421
Ref: library/signal signal SIGPROF12113582
Ref: 3a5012113582
Ref: library/signal signal SIGQUIT12113678
Ref: 3a4b12113678
Ref: library/signal signal SIGSEGV12113771
Ref: 128212113771
Ref: library/signal signal SIGSTOP12113849
Ref: 3a5112113849
Ref: library/signal signal SIGSTKFLT12113927
Ref: 1bef12113927
Ref: library/signal signal SIGTERM12114267
Ref: 15e612114267
Ref: library/signal signal SIGUSR112114319
Ref: 3a5212114319
Ref: library/signal signal SIGUSR212114413
Ref: 3a5312114413
Ref: library/signal signal SIGVTALRM12114507
Ref: 3a5412114507
Ref: library/signal signal SIGWINCH12114603
Ref: 3a5512114603
Ref: library/signal signal SIGXCPU12114697
Ref: 3a5612114697
Ref: library/signal signal CTRL_C_EVENT12115360
Ref: 157012115360
Ref: library/signal signal CTRL_BREAK_EVENT12115598
Ref: 157112115598
Ref: library/signal signal NSIG12115843
Ref: 1b7312115843
Ref: library/signal signal ITIMER_REAL12115995
Ref: 3a5812115995
Ref: library/signal signal ITIMER_VIRTUAL12116127
Ref: 3a5912116127
Ref: library/signal signal ITIMER_PROF12116273
Ref: 3a5a12116273
Ref: library/signal signal SIG_BLOCK12116612
Ref: 3a4512116612
Ref: library/signal signal SIG_UNBLOCK12116797
Ref: 3a4612116797
Ref: library/signal signal SIG_SETMASK12116991
Ref: 3a4712116991
Ref: library/signal signal ItimerError12117244
Ref: 3a5b12117244
Ref: library/signal signal alarm12117770
Ref: 3a5e12117770
Ref: library/signal signal getsignal12118417
Ref: 1a0d12118417
Ref: library/signal signal strsignal12118989
Ref: 1e0712118989
Ref: library/signal signal valid_signals12119293
Ref: 3a5712119293
Ref: library/signal signal pause12119538
Ref: 3a5f12119538
Ref: library/signal signal raise_signal12119930
Ref: 1b7712119930
Ref: library/signal signal pidfd_send_signal12120065
Ref: b2712120065
Ref: library/signal signal pthread_kill12120626
Ref: 133912120626
Ref: library/signal signal pthread_sigmask12121859
Ref: 133812121859
Ref: library/signal signal setitimer12123301
Ref: 3a5c12123301
Ref: library/signal signal getitimer12124332
Ref: 3a5d12124332
Ref: library/signal signal set_wakeup_fd12124492
Ref: d6912124492
Ref: library/signal signal siginterrupt12126890
Ref: 133d12126890
Ref: library/signal signal signal12127498
Ref: 133c12127498
Ref: library/signal signal sigpending12129004
Ref: 133a12129004
Ref: library/signal signal sigwait12129471
Ref: 133b12129471
Ref: library/signal signal sigwaitinfo12130057
Ref: fad12130057
Ref: library/signal signal sigtimedwait12131334
Ref: fac12131334
Ref: Module contents<2>-Footnote-112132116
Ref: Module contents<2>-Footnote-212132167
Ref: Module contents<2>-Footnote-312132222
Ref: Module contents<2>-Footnote-412132267
Ref: Module contents<2>-Footnote-512132312
Ref: Module contents<2>-Footnote-612132358
Ref: Module contents<2>-Footnote-712132404
Ref: Module contents<2>-Footnote-812132450
Ref: Module contents<2>-Footnote-912132495
Ref: Module contents<2>-Footnote-1012132541
Ref: Module contents<2>-Footnote-1112132599
Ref: Module contents<2>-Footnote-1212132652
Ref: Module contents<2>-Footnote-1312132704
Ref: Module contents<2>-Footnote-1412132760
Ref: Module contents<2>-Footnote-1512132813
Ref: Module contents<2>-Footnote-1612132860
Ref: Module contents<2>-Footnote-1712132911
Ref: Module contents<2>-Footnote-1812132959
Ref: Module contents<2>-Footnote-1912133011
Ref: Module contents<2>-Footnote-2012133054
Ref: Module contents<2>-Footnote-2112133107
Node: Examples<23>12133150
Ref: library/signal examples12133297
Ref: 3a6012133297
Ref: library/signal signal-example12133297
Ref: 3a6112133297
Node: Note on SIGPIPE12134259
Ref: library/signal note-on-sigpipe12134426
Ref: 3a6212134426
Ref: Note on SIGPIPE-Footnote-112135875
Node: Note on Signal Handlers and Exceptions12135919
Ref: library/signal handlers-and-exceptions12136065
Ref: 26cf12136065
Ref: library/signal note-on-signal-handlers-and-exceptions12136065
Ref: 3a6312136065
Node: mmap — Memory-mapped file support12138672
Ref: library/mmap doc12138841
Ref: 3a6412138841
Ref: library/mmap mmap-memory-mapped-file-support12138841
Ref: 3a6512138841
Ref: library/mmap module-mmap12138841
Ref: 9412138841
Ref: library/mmap translation-repo12138841
Ref: 3a6612138841
Ref: library/mmap mmap mmap12141453
Ref: 51a12141453
Ref: library/mmap mmap mmap close12147071
Ref: 3a6c12147071
Ref: library/mmap mmap mmap closed12147282
Ref: 3a6d12147282
Ref: library/mmap mmap mmap find12147388
Ref: 3a6e12147388
Ref: library/mmap mmap mmap flush12147823
Ref: c9112147823
Ref: library/mmap mmap mmap madvise12148742
Ref: bfd12148742
Ref: library/mmap mmap mmap move12149310
Ref: 3a7012149310
Ref: library/mmap mmap mmap read12149588
Ref: 12e512149588
Ref: library/mmap mmap mmap read_byte12150055
Ref: 3a7112150055
Ref: library/mmap mmap mmap readline12150203
Ref: 3a7212150203
Ref: library/mmap mmap mmap resize12150428
Ref: 3a6b12150428
Ref: library/mmap mmap mmap rfind12151292
Ref: 3a7312151292
Ref: library/mmap mmap mmap seek12151729
Ref: 51c12151729
Ref: library/mmap mmap mmap seekable12152222
Ref: 51b12152222
Ref: library/mmap mmap mmap size12152392
Ref: 3a6a12152392
Ref: library/mmap mmap mmap tell12152531
Ref: 3a7412152531
Ref: library/mmap mmap mmap write12152618
Ref: f4812152618
Ref: library/mmap mmap mmap write_byte12153335
Ref: 3a7512153335
Node: MADV_* Constants12153701
Ref: library/mmap madv-constants12153813
Ref: 3a7612153813
Ref: library/mmap madvise-constants12153813
Ref: 3a6f12153813
Ref: library/mmap mmap MADV_NORMAL12153866
Ref: 3a7712153866
Ref: library/mmap mmap MADV_RANDOM12153893
Ref: 3a7812153893
Ref: library/mmap mmap MADV_SEQUENTIAL12153920
Ref: 3a7912153920
Ref: library/mmap mmap MADV_WILLNEED12153951
Ref: 3a7a12153951
Ref: library/mmap mmap MADV_DONTNEED12153980
Ref: 3a7b12153980
Ref: library/mmap mmap MADV_REMOVE12154009
Ref: 3a7c12154009
Ref: library/mmap mmap MADV_DONTFORK12154036
Ref: 3a7d12154036
Ref: library/mmap mmap MADV_DOFORK12154065
Ref: 3a7e12154065
Ref: library/mmap mmap MADV_HWPOISON12154092
Ref: 3a7f12154092
Ref: library/mmap mmap MADV_MERGEABLE12154121
Ref: 3a8012154121
Ref: library/mmap mmap MADV_UNMERGEABLE12154151
Ref: 3a8112154151
Ref: library/mmap mmap MADV_SOFT_OFFLINE12154183
Ref: 3a8212154183
Ref: library/mmap mmap MADV_HUGEPAGE12154216
Ref: 3a8312154216
Ref: library/mmap mmap MADV_NOHUGEPAGE12154245
Ref: 3a8412154245
Ref: library/mmap mmap MADV_DONTDUMP12154276
Ref: 3a8512154276
Ref: library/mmap mmap MADV_DODUMP12154305
Ref: 3a8612154305
Ref: library/mmap mmap MADV_FREE12154332
Ref: 3a8712154332
Ref: library/mmap mmap MADV_NOSYNC12154357
Ref: 3a8812154357
Ref: library/mmap mmap MADV_AUTOSYNC12154384
Ref: 3a8912154384
Ref: library/mmap mmap MADV_NOCORE12154413
Ref: 3a8a12154413
Ref: library/mmap mmap MADV_CORE12154440
Ref: 3a8b12154440
Ref: library/mmap mmap MADV_PROTECT12154465
Ref: 3a8c12154465
Ref: library/mmap mmap MADV_FREE_REUSABLE12154493
Ref: 3a8d12154493
Ref: library/mmap mmap MADV_FREE_REUSE12154527
Ref: 3a8e12154527
Node: MAP_* Constants12154767
Ref: library/mmap id112154879
Ref: 3a8f12154879
Ref: library/mmap map-constants12154879
Ref: 3a6912154879
Ref: library/mmap mmap MAP_SHARED12154930
Ref: 3a6812154930
Ref: library/mmap mmap MAP_PRIVATE12154956
Ref: 3a6712154956
Ref: library/mmap mmap MAP_32BIT12154983
Ref: 1a0412154983
Ref: library/mmap mmap MAP_ALIGNED_SUPER12155008
Ref: 1aaf12155008
Ref: library/mmap mmap MAP_ANON12155041
Ref: 3a9012155041
Ref: library/mmap mmap MAP_ANONYMOUS12155065
Ref: 3a9112155065
Ref: library/mmap mmap MAP_CONCEAL12155094
Ref: 1ab012155094
Ref: library/mmap mmap MAP_DENYWRITE12155121
Ref: 3a9212155121
Ref: library/mmap mmap MAP_EXECUTABLE12155150
Ref: 3a9312155150
Ref: library/mmap mmap MAP_HASSEMAPHORE12155180
Ref: 19ff12155180
Ref: library/mmap mmap MAP_JIT12155212
Ref: 1a0112155212
Ref: library/mmap mmap MAP_NOCACHE12155235
Ref: 1a0012155235
Ref: library/mmap mmap MAP_NOEXTEND12155262
Ref: 19fe12155262
Ref: library/mmap mmap MAP_NORESERVE12155290
Ref: 19fd12155290
Ref: library/mmap mmap MAP_POPULATE12155319
Ref: 1d1712155319
Ref: library/mmap mmap MAP_RESILIENT_CODESIGN12155347
Ref: 1a0212155347
Ref: library/mmap mmap MAP_RESILIENT_MEDIA12155385
Ref: 1a0312155385
Ref: library/mmap mmap MAP_STACK12155420
Ref: 3a9412155420
Ref: library/mmap mmap MAP_TPRO12155445
Ref: 1a0712155445
Ref: library/mmap mmap MAP_TRANSLATED_ALLOW_EXECUTE12155469
Ref: 1a0512155469
Ref: library/mmap mmap MAP_UNIX0312155513
Ref: 1a0612155513
Node: Internet Data Handling12156467
Ref: library/netdata doc12156646
Ref: 3a9512156646
Ref: library/netdata internet-data-handling12156646
Ref: 3a9612156646
Ref: library/netdata netdata12156646
Ref: 3a9712156646
Ref: library/netdata translation-repo12156646
Ref: 3a9812156646
Node: email — An email and MIME handling package12157226
Ref: library/email doc12157371
Ref: 3a9912157371
Ref: library/email email-an-email-and-mime-handling-package12157371
Ref: 3a9a12157371
Ref: library/email module-email12157371
Ref: 3f12157371
Ref: email — An email and MIME handling package-Footnote-112164110
Ref: email — An email and MIME handling package-Footnote-212164184
Ref: email — An email and MIME handling package-Footnote-312164243
Ref: email — An email and MIME handling package-Footnote-412164302
Ref: email — An email and MIME handling package-Footnote-512164361
Ref: email — An email and MIME handling package-Footnote-612164420
Ref: email — An email and MIME handling package-Footnote-712164479
Ref: email — An email and MIME handling package-Footnote-812164538
Ref: email — An email and MIME handling package-Footnote-912164597
Node: email message Representing an email message12164656
Ref: library/email message doc12164824
Ref: 3a9b12164824
Ref: library/email message email-message-representing-an-email-message12164824
Ref: 3a9c12164824
Ref: library/email message module-email message12164824
Ref: 4812164824
Ref: library/email message email message EmailMessage12167297
Ref: 58012167297
Ref: library/email message email message EmailMessage as_string12167784
Ref: 3a9e12167784
Ref: library/email message email message EmailMessage __str__12169640
Ref: 3aa012169640
Ref: library/email message email message EmailMessage as_bytes12170114
Ref: 3aa112170114
Ref: library/email message email message EmailMessage __bytes__12171278
Ref: 3aa212171278
Ref: library/email message email message EmailMessage is_multipart12171454
Ref: 3aa312171454
Ref: library/email message email message EmailMessage set_unixfrom12172137
Ref: 3aa412172137
Ref: library/email message email message EmailMessage get_unixfrom12172359
Ref: 3aa612172359
Ref: library/email message email message EmailMessage __len__12173491
Ref: 3aa812173491
Ref: library/email message email message EmailMessage __contains__12173589
Ref: 3aa912173589
Ref: library/email message email message EmailMessage __getitem__12173979
Ref: 3aaa12173979
Ref: library/email message email message EmailMessage __setitem__12174696
Ref: 3aad12174696
Ref: library/email message email message EmailMessage __delitem__12175734
Ref: 3aae12175734
Ref: library/email message email message EmailMessage keys12175960
Ref: 3aa712175960
Ref: library/email message email message EmailMessage values12176054
Ref: 3aaf12176054
Ref: library/email message email message EmailMessage items12176144
Ref: 3ab012176144
Ref: library/email message email message EmailMessage get12176275
Ref: 3ab112176275
Ref: library/email message email message EmailMessage get_all12176623
Ref: 3aab12176623
Ref: library/email message email message EmailMessage add_header12176860
Ref: 3ab212176860
Ref: library/email message email message EmailMessage replace_header12178824
Ref: 3ab312178824
Ref: library/email message email message EmailMessage get_content_type12179130
Ref: 3ab412179130
Ref: library/email message email message EmailMessage get_content_maintype12180015
Ref: 3ab612180015
Ref: library/email message email message EmailMessage get_content_subtype12180221
Ref: 3ab712180221
Ref: library/email message email message EmailMessage get_default_type12180414
Ref: 3ab512180414
Ref: library/email message email message EmailMessage set_default_type12180734
Ref: 3ab812180734
Ref: library/email message email message EmailMessage set_param12181176
Ref: 3ab912181176
Ref: library/email message email message EmailMessage del_param12182802
Ref: 3abb12182802
Ref: library/email message email message EmailMessage get_filename12183238
Ref: 3abc12183238
Ref: library/email message email message EmailMessage get_boundary12183777
Ref: 3abe12183777
Ref: library/email message email message EmailMessage set_boundary12184141
Ref: 3abf12184141
Ref: library/email message email message EmailMessage get_content_charset12184809
Ref: 3ac112184809
Ref: library/email message email message EmailMessage get_charsets12185111
Ref: 3ac212185111
Ref: library/email message email message EmailMessage is_attachment12185804
Ref: 3ac312185804
Ref: library/email message email message EmailMessage get_content_disposition12186176
Ref: 3ac512186176
Ref: library/email message email message EmailMessage walk12186653
Ref: 3ac612186653
Ref: library/email message email message EmailMessage get_body12188666
Ref: 3ac712188666
Ref: library/email message email message EmailMessage iter_attachments12190783
Ref: 3ac812190783
Ref: library/email message email message EmailMessage iter_parts12191755
Ref: 3ac912191755
Ref: library/email message email message EmailMessage get_content12191968
Ref: 3aca12191968
Ref: library/email message email message EmailMessage set_content12192378
Ref: 1c4512192378
Ref: library/email message email message EmailMessage make_related12192788
Ref: 3acd12192788
Ref: library/email message email message EmailMessage make_alternative12193276
Ref: 3ace12193276
Ref: library/email message email message EmailMessage make_mixed12193795
Ref: 3acf12193795
Ref: library/email message email message EmailMessage add_related12194334
Ref: 3ad012194334
Ref: library/email message email message EmailMessage add_alternative12195091
Ref: 3ad212195091
Ref: library/email message email message EmailMessage add_attachment12195781
Ref: 3ad312195781
Ref: library/email message email message EmailMessage clear12196766
Ref: 3ad412196766
Ref: library/email message email message EmailMessage clear_content12196847
Ref: 3ad512196847
Ref: library/email message email message EmailMessage preamble12197108
Ref: 3ad612197108
Ref: library/email message email message EmailMessage epilogue12198372
Ref: 3ad712198372
Ref: library/email message email message EmailMessage defects12198718
Ref: 3ad812198718
Ref: library/email message email message MIMEPart12198960
Ref: 113c12198960
Ref: email message Representing an email message-Footnote-112199327
Ref: email message Representing an email message-Footnote-212199400
Ref: email message Representing an email message-Footnote-312199597
Ref: email message Representing an email message-Footnote-412199656
Ref: email message Representing an email message-Footnote-512199715
Ref: email message Representing an email message-Footnote-612199774
Ref: email message Representing an email message-Footnote-712200096
Ref: email message Representing an email message-Footnote-812200155
Ref: email message Representing an email message-Footnote-912200214
Ref: email message Representing an email message-Footnote-1012200273
Ref: email message Representing an email message-Footnote-1112200333
Ref: email message Representing an email message-Footnote-1212200393
Ref: email message Representing an email message-Footnote-1312200453
Ref: email message Representing an email message-Footnote-1412200513
Node: email parser Parsing email messages12200573
Ref: library/email parser doc12200791
Ref: 3ad912200791
Ref: library/email parser email-parser-parsing-email-messages12200791
Ref: 3ada12200791
Ref: library/email parser module-email parser12200791
Ref: 5212200791
Ref: library/email parser translation-repo12200791
Ref: 3adb12200791
Ref: email parser Parsing email messages-Footnote-112203185
Node: FeedParser API12203257
Ref: library/email parser feedparser-api12203362
Ref: 3adc12203362
Ref: library/email parser email parser BytesFeedParser12204661
Ref: 13d312204661
Ref: library/email parser email parser BytesFeedParser feed12205875
Ref: 3add12205875
Ref: library/email parser email parser BytesFeedParser close12206310
Ref: 3ade12206310
Ref: library/email parser email parser FeedParser12206550
Ref: 176c12206550
Node: Parser API12207021
Ref: library/email parser parser-api12207151
Ref: 3adf12207151
Ref: library/email parser email parser BytesParser12207885
Ref: 13d412207885
Ref: library/email parser email parser BytesParser parse12208565
Ref: 3ae012208565
Ref: library/email parser email parser BytesParser parsebytes12209610
Ref: 3ae112209610
Ref: library/email parser email parser BytesHeaderParser12210119
Ref: 12c312210119
Ref: library/email parser email parser Parser12210341
Ref: 13a512210341
Ref: library/email parser email parser Parser parse12210698
Ref: 3ae212210698
Ref: library/email parser email parser Parser parsestr12211136
Ref: 3ae312211136
Ref: library/email parser email parser HeaderParser12211576
Ref: 12c412211576
Ref: library/email parser email message_from_bytes12211975
Ref: 13d112211975
Ref: library/email parser email message_from_binary_file12212450
Ref: 13d212212450
Ref: library/email parser email message_from_string12212933
Ref: 3ae412212933
Ref: library/email parser email message_from_file12213334
Ref: 3ae512213334
Ref: Parser API-Footnote-112214076
Ref: Parser API-Footnote-212214135
Node: Additional notes12214194
Ref: library/email parser additional-notes12214301
Ref: 3ae612214301
Node: email generator Generating MIME documents12215855
Ref: library/email generator doc12216057
Ref: 3ae812216057
Ref: library/email generator email-generator-generating-mime-documents12216057
Ref: 3ae912216057
Ref: library/email generator module-email generator12216057
Ref: 4412216057
Ref: library/email generator translation-repo12216057
Ref: 3aea12216057
Ref: library/email generator email generator BytesGenerator12218148
Ref: 13d712218148
Ref: library/email generator email generator BytesGenerator flatten12220073
Ref: 3aec12220073
Ref: library/email generator email generator BytesGenerator clone12221896
Ref: 3aef12221896
Ref: library/email generator email generator BytesGenerator write12222095
Ref: 3aed12222095
Ref: library/email generator email generator Generator12223149
Ref: 13d612223149
Ref: library/email generator email generator Generator flatten12225012
Ref: 3af012225012
Ref: library/email generator email generator Generator clone12226778
Ref: 3af212226778
Ref: library/email generator email generator Generator write12226964
Ref: 3af112226964
Ref: library/email generator email generator DecodedGenerator12227877
Ref: e9712227877
Ref: email generator Generating MIME documents-Footnote-112229295
Ref: email generator Generating MIME documents-Footnote-212229371
Ref: email generator Generating MIME documents-Footnote-312229878
Ref: email generator Generating MIME documents-Footnote-412229930
Ref: email generator Generating MIME documents-Footnote-512229989
Ref: email generator Generating MIME documents-Footnote-612230041
Node: email policy Policy Objects12230100
Ref: library/email policy doc12230308
Ref: 3af312230308
Ref: library/email policy email-policy-policy-objects12230308
Ref: 3af412230308
Ref: library/email policy module-email policy12230308
Ref: 5312230308
Ref: library/email policy translation-repo12230308
Ref: 3af512230308
Ref: library/email policy email policy Policy12236287
Ref: 12bb12236287
Ref: library/email policy email policy Policy max_line_length12237111
Ref: 3a9f12237111
Ref: library/email policy email policy Policy linesep12237417
Ref: 3af612237417
Ref: library/email policy email policy Policy cte_type12237686
Ref: 3aee12237686
Ref: library/email policy email policy Policy raise_on_defect12238795
Ref: 3af812238795
Ref: library/email policy email policy Policy mangle_from_12239039
Ref: ff912239039
Ref: library/email policy email policy Policy message_factory12239366
Ref: e9812239366
Ref: library/email policy email policy Policy verify_generated_headers12239643
Ref: 4f312239643
Ref: library/email policy email policy Policy clone12240491
Ref: 12bd12240491
Ref: library/email policy email policy Policy handle_defect12240977
Ref: 3afb12240977
Ref: library/email policy email policy Policy register_defect12241469
Ref: 3af912241469
Ref: library/email policy email policy Policy header_max_count12242175
Ref: 3afd12242175
Ref: library/email policy email policy Policy header_source_parse12243237
Ref: 3afe12243237
Ref: library/email policy email policy Policy header_store_parse12244250
Ref: 3aff12244250
Ref: library/email policy email policy Policy header_fetch_parse12245011
Ref: 3b0012245011
Ref: library/email policy email policy Policy fold12245834
Ref: 3b0112245834
Ref: library/email policy email policy Policy fold_binary12246548
Ref: 3af712246548
Ref: library/email policy email policy EmailPolicy12246882
Ref: 12bf12246882
Ref: library/email policy email policy EmailPolicy utf812247716
Ref: ffb12247716
Ref: library/email policy email policy EmailPolicy refold_source12248110
Ref: 3aeb12248110
Ref: library/email policy email policy EmailPolicy header_factory12248905
Ref: 3b0212248905
Ref: library/email policy email policy EmailPolicy content_manager12249516
Ref: 113d12249516
Ref: library/email policy email policy EmailPolicy header_max_count12250228
Ref: 3b0412250228
Ref: library/email policy email policy EmailPolicy header_source_parse12250434
Ref: 18fa12250434
Ref: library/email policy email policy EmailPolicy header_store_parse12250819
Ref: 3b0612250819
Ref: library/email policy email policy EmailPolicy header_fetch_parse12251300
Ref: 3b0712251300
Ref: library/email policy email policy EmailPolicy fold12251726
Ref: 19da12251726
Ref: library/email policy email policy EmailPolicy fold_binary12252889
Ref: 3b0812252889
Ref: library/email policy email policy default12253709
Ref: 176d12253709
Ref: library/email policy email policy SMTP12253919
Ref: 3b0912253919
Ref: library/email policy email policy SMTPUTF812254121
Ref: 3b0a12254121
Ref: library/email policy email policy HTTP12254536
Ref: 3b0b12254536
Ref: library/email policy email policy strict12254728
Ref: 3b0c12254728
Ref: library/email policy email policy Compat3212256106
Ref: 12bc12256106
Ref: library/email policy email policy Compat32 mangle_from_12256640
Ref: 3b0d12256640
Ref: library/email policy email policy Compat32 header_source_parse12256829
Ref: 18fb12256829
Ref: library/email policy email policy Compat32 header_store_parse12257214
Ref: 3b0e12257214
Ref: library/email policy email policy Compat32 header_fetch_parse12257320
Ref: 3b0f12257320
Ref: library/email policy email policy Compat32 fold12257562
Ref: 3b1012257562
Ref: library/email policy email policy Compat32 fold_binary12257905
Ref: 3b1112257905
Ref: library/email policy email policy compat3212258435
Ref: e9912258435
Ref: email policy Policy Objects-Footnote-112258890
Ref: email policy Policy Objects-Footnote-212258962
Ref: email policy Policy Objects-Footnote-312259021
Ref: email policy Policy Objects-Footnote-412259080
Ref: email policy Policy Objects-Footnote-512259139
Ref: email policy Policy Objects-Footnote-612259198
Ref: email policy Policy Objects-Footnote-712259257
Ref: email policy Policy Objects-Footnote-812259316
Ref: email policy Policy Objects-Footnote-912259386
Ref: email policy Policy Objects-Footnote-1012259445
Ref: email policy Policy Objects-Footnote-1112259505
Ref: email policy Policy Objects-Footnote-1212259565
Node: email errors Exception and Defect classes12259625
Ref: library/email errors doc12259834
Ref: 3b1212259834
Ref: library/email errors email-errors-exception-and-defect-classes12259834
Ref: 3b1312259834
Ref: library/email errors module-email errors12259834
Ref: 4312259834
Ref: library/email errors translation-repo12259834
Ref: 3b1412259834
Ref: library/email errors email errors MessageError12260138
Ref: 3b1512260138
Ref: library/email errors email errors MessageParseError12260379
Ref: 3b1612260379
Ref: library/email errors email errors HeaderParseError12260656
Ref: 3ac012260656
Ref: library/email errors email errors BoundaryError12261299
Ref: 3b1712261299
Ref: library/email errors email errors MultipartConversionError12261379
Ref: 3b1812261379
Ref: library/email errors email errors HeaderWriteError12261740
Ref: 3afa12261740
Ref: library/email errors email errors MessageDefect12261872
Ref: 3afc12261872
Ref: library/email errors email errors HeaderDefect12262043
Ref: 3b1b12262043
Ref: library/email errors email errors NoBoundaryInMultipartDefect12262656
Ref: 3b1c12262656
Ref: library/email errors email errors StartBoundaryNotFoundDefect12262798
Ref: 3b1d12262798
Ref: library/email errors email errors CloseBoundaryNotFoundDefect12262943
Ref: 3b1e12262943
Ref: library/email errors email errors FirstHeaderLineIsContinuationDefect12263119
Ref: 3b1f12263119
Ref: library/email errors email errors MisplacedEnvelopeHeaderDefect12263252
Ref: 3b2012263252
Ref: library/email errors email errors MissingHeaderBodySeparatorDefect12263383
Ref: 3b2112263383
Ref: library/email errors email errors MalformedHeaderDefect12263667
Ref: 3b2212263667
Ref: library/email errors email errors MultipartInvariantViolationDefect12263902
Ref: 3ae712263902
Ref: library/email errors email errors InvalidBase64PaddingDefect12264220
Ref: 3b2312264220
Ref: library/email errors email errors InvalidBase64CharactersDefect12264464
Ref: 3b2412264464
Ref: library/email errors email errors InvalidBase64LengthDefect12264720
Ref: 3b2512264720
Ref: library/email errors email errors InvalidDateDefect12264960
Ref: 3b2612264960
Ref: email errors Exception and Defect classes-Footnote-112265140
Ref: email errors Exception and Defect classes-Footnote-212265212
Node: email headerregistry Custom Header Objects12265271
Ref: library/email headerregistry doc12265495
Ref: 3b2712265495
Ref: library/email headerregistry email-headerregistry-custom-header-objects12265495
Ref: 3b2812265495
Ref: library/email headerregistry module-email headerregistry12265495
Ref: 4612265495
Ref: library/email headerregistry translation-repo12265495
Ref: 3b2912265495
Ref: library/email headerregistry email headerregistry BaseHeader12267264
Ref: 3aac12267264
Ref: library/email headerregistry email headerregistry BaseHeader name12267578
Ref: 3b2c12267578
Ref: library/email headerregistry email headerregistry BaseHeader defects12267829
Ref: 3b2d12267829
Ref: library/email headerregistry email headerregistry BaseHeader max_count12268188
Ref: 3b0512268188
Ref: library/email headerregistry email headerregistry BaseHeader fold12268705
Ref: 3b2e12268705
Ref: library/email headerregistry email headerregistry UnstructuredHeader12270896
Ref: 3b2b12270896
Ref: library/email headerregistry email headerregistry DateHeader12271974
Ref: 3b2f12271974
Ref: library/email headerregistry email headerregistry DateHeader datetime12272336
Ref: 3b3012272336
Ref: library/email headerregistry email headerregistry AddressHeader12273905
Ref: 3b3112273905
Ref: library/email headerregistry email headerregistry AddressHeader groups12274190
Ref: 3b3212274190
Ref: library/email headerregistry email headerregistry AddressHeader addresses12274505
Ref: 3b3512274505
Ref: library/email headerregistry email headerregistry SingleAddressHeader12275665
Ref: 3b3712275665
Ref: library/email headerregistry email headerregistry SingleAddressHeader address12275807
Ref: 3b3812275807
Ref: library/email headerregistry email headerregistry MIMEVersionHeader12276339
Ref: 3b3912276339
Ref: library/email headerregistry email headerregistry MIMEVersionHeader version12276732
Ref: 3b3a12276732
Ref: library/email headerregistry email headerregistry MIMEVersionHeader major12276859
Ref: 3b3b12276859
Ref: library/email headerregistry email headerregistry MIMEVersionHeader minor12276936
Ref: 3b3c12276936
Ref: library/email headerregistry email headerregistry ParameterizedMIMEHeader12277013
Ref: 3b3d12277013
Ref: library/email headerregistry email headerregistry ParameterizedMIMEHeader params12277397
Ref: 3aba12277397
Ref: library/email headerregistry email headerregistry ContentTypeHeader12277494
Ref: 3b3e12277494
Ref: library/email headerregistry email headerregistry ContentTypeHeader content_type12277646
Ref: 3b3f12277646
Ref: library/email headerregistry email headerregistry ContentTypeHeader maintype12277752
Ref: 3b4012277752
Ref: library/email headerregistry email headerregistry ContentTypeHeader subtype12277782
Ref: 3b4112277782
Ref: library/email headerregistry email headerregistry ContentDispositionHeader12277811
Ref: 3b4212277811
Ref: library/email headerregistry email headerregistry ContentDispositionHeader content_disposition12277977
Ref: 3b4312277977
Ref: library/email headerregistry email headerregistry ContentTransferEncodingHeader12278114
Ref: 3b4412278114
Ref: library/email headerregistry email headerregistry ContentTransferEncodingHeader cte12278236
Ref: 3b4512278236
Ref: library/email headerregistry email headerregistry HeaderRegistry12278405
Ref: 3b2a12278405
Ref: library/email headerregistry email headerregistry HeaderRegistry map_to_type12280139
Ref: 3b4612280139
Ref: library/email headerregistry email headerregistry HeaderRegistry __getitem__12280474
Ref: 3b4712280474
Ref: library/email headerregistry email headerregistry HeaderRegistry __call__12280597
Ref: 3b4812280597
Ref: library/email headerregistry email headerregistry Address12281239
Ref: 3b3612281239
Ref: library/email headerregistry email headerregistry Address display_name12282079
Ref: 3b4912282079
Ref: library/email headerregistry email headerregistry Address username12282305
Ref: 3b4a12282305
Ref: library/email headerregistry email headerregistry Address domain12282425
Ref: 3b4b12282425
Ref: library/email headerregistry email headerregistry Address addr_spec12282505
Ref: 3b4c12282505
Ref: library/email headerregistry email headerregistry Address __str__12282723
Ref: 3b4d12282723
Ref: library/email headerregistry email headerregistry Group12283162
Ref: 3b3312283162
Ref: library/email headerregistry email headerregistry Group display_name12283712
Ref: 3b3412283712
Ref: library/email headerregistry email headerregistry Group addresses12283967
Ref: 3b4e12283967
Ref: library/email headerregistry email headerregistry Group __str__12284115
Ref: 3b4f12284115
Ref: email headerregistry Custom Header Objects-Footnote-112284555
Ref: email headerregistry Custom Header Objects-Footnote-212284636
Ref: email headerregistry Custom Header Objects-Footnote-312284705
Ref: email headerregistry Custom Header Objects-Footnote-412284764
Ref: email headerregistry Custom Header Objects-Footnote-512284823
Ref: email headerregistry Custom Header Objects-Footnote-612284882
Ref: email headerregistry Custom Header Objects-Footnote-712284941
Ref: email headerregistry Custom Header Objects-Footnote-812285000
Ref: email headerregistry Custom Header Objects-Footnote-912285059
Ref: email headerregistry Custom Header Objects-Footnote-1012285118
Ref: email headerregistry Custom Header Objects-Footnote-1112285178
Ref: email headerregistry Custom Header Objects-Footnote-1212285238
Ref: email headerregistry Custom Header Objects-Footnote-1312285298
Ref: email headerregistry Custom Header Objects-Footnote-1412285358
Ref: email headerregistry Custom Header Objects-Footnote-1512285418
Ref: email headerregistry Custom Header Objects-Footnote-1612285478
Ref: email headerregistry Custom Header Objects-Footnote-1712285538
Node: email contentmanager Managing MIME Content12285598
Ref: library/email contentmanager doc12285795
Ref: 3b5012285795
Ref: library/email contentmanager email-contentmanager-managing-mime-content12285795
Ref: 3b5112285795
Ref: library/email contentmanager module-email contentmanager12285795
Ref: 4112285795
Ref: library/email contentmanager translation-repo12285795
Ref: 3b5212285795
Ref: library/email contentmanager email contentmanager ContentManager12286054
Ref: 3b5312286054
Ref: library/email contentmanager email contentmanager ContentManager get_content12286344
Ref: 3acb12286344
Ref: library/email contentmanager email contentmanager ContentManager set_content12287178
Ref: 3acc12287178
Ref: library/email contentmanager email contentmanager ContentManager add_get_handler12288811
Ref: 3b5412288811
Ref: library/email contentmanager email contentmanager ContentManager add_set_handler12289003
Ref: 3b5612289003
Ref: email contentmanager Managing MIME Content-Footnote-112289368
Ref: email contentmanager Managing MIME Content-Footnote-212289449
Node: Content Manager Instances12289518
Ref: library/email contentmanager content-manager-instances12289622
Ref: 3b5812289622
Ref: library/email contentmanager email contentmanager raw_data_manager12289964
Ref: 3b0312289964
Ref: library/email contentmanager email contentmanager get_content12290694
Ref: 3b5512290694
Ref: library/email contentmanager email contentmanager set_content12291293
Ref: 3b5712291293
Ref: Content Manager Instances-Footnote-112296077
Node: email Examples12296136
Ref: library/email examples doc12296365
Ref: 3b5912296365
Ref: library/email examples email-examples12296365
Ref: 113e12296365
Ref: library/email examples id112296365
Ref: 3b5a12296365
Ref: library/email examples translation-repo12296365
Ref: 3b5b12296365
Ref: email Examples-Footnote-112310991
Ref: email Examples-Footnote-212311049
Node: email message Message Representing an email message using the compat32 API12311131
Ref: library/email compat32-message doc12311373
Ref: 3b5c12311373
Ref: library/email compat32-message compat32-message12311373
Ref: 3a9d12311373
Ref: library/email compat32-message email-message-message-representing-an-email-message-using-the-compat32-api12311373
Ref: 3b5d12311373
Ref: library/email compat32-message translation-repo12311373
Ref: 3b5e12311373
Ref: library/email compat32-message email message Message12313931
Ref: 58112313931
Ref: library/email compat32-message email message Message as_string12314475
Ref: 113812314475
Ref: library/email compat32-message email message Message __str__12316629
Ref: 3b5f12316629
Ref: library/email compat32-message email message Message as_bytes12316795
Ref: 113912316795
Ref: library/email compat32-message email message Message __bytes__12318353
Ref: 113a12318353
Ref: library/email compat32-message email message Message is_multipart12318561
Ref: 3ac412318561
Ref: library/email compat32-message email message Message set_unixfrom12319235
Ref: 3b6012319235
Ref: library/email compat32-message email message Message get_unixfrom12319375
Ref: 3b6112319375
Ref: library/email compat32-message email message Message attach12319532
Ref: 3ad112319532
Ref: library/email compat32-message email message Message get_payload12320156
Ref: 13d512320156
Ref: library/email compat32-message email message Message set_payload12322838
Ref: 3b6212322838
Ref: library/email compat32-message email message Message set_charset12323322
Ref: 3b6312323322
Ref: library/email compat32-message email message Message get_charset12325099
Ref: 3b6412325099
Ref: library/email compat32-message email message Message __len__12326557
Ref: 3b6612326557
Ref: library/email compat32-message email message Message __contains__12326655
Ref: 1adc12326655
Ref: library/email compat32-message email message Message __getitem__12327025
Ref: 3b6712327025
Ref: library/email compat32-message email message Message __setitem__12327560
Ref: 186512327560
Ref: library/email compat32-message email message Message __delitem__12328117
Ref: 3b6912328117
Ref: library/email compat32-message email message Message keys12328343
Ref: 3b6512328343
Ref: library/email compat32-message email message Message values12328437
Ref: 3b6a12328437
Ref: library/email compat32-message email message Message items12328527
Ref: 3b6b12328527
Ref: library/email compat32-message email message Message get12328658
Ref: 3b6c12328658
Ref: library/email compat32-message email message Message get_all12328971
Ref: 3b6812328971
Ref: library/email compat32-message email message Message add_header12329208
Ref: 186612329208
Ref: library/email compat32-message email message Message replace_header12331174
Ref: 3b6d12331174
Ref: library/email compat32-message email message Message get_content_type12331463
Ref: 3b6e12331463
Ref: library/email compat32-message email message Message get_content_maintype12332321
Ref: 3b7012332321
Ref: library/email compat32-message email message Message get_content_subtype12332527
Ref: 3b7112332527
Ref: library/email compat32-message email message Message get_default_type12332720
Ref: 3b6f12332720
Ref: library/email compat32-message email message Message set_default_type12333040
Ref: 3b7212333040
Ref: library/email compat32-message email message Message get_params12333327
Ref: 3b7312333327
Ref: library/email compat32-message email message Message get_param12334389
Ref: 3b7412334389
Ref: library/email compat32-message email message Message set_param12336397
Ref: 113b12336397
Ref: library/email compat32-message email message Message del_param12337669
Ref: 3b7612337669
Ref: library/email compat32-message email message Message set_type12338110
Ref: 3b7712338110
Ref: library/email compat32-message email message Message get_filename12338999
Ref: 3b7812338999
Ref: library/email compat32-message email message Message get_boundary12339538
Ref: 3b7912339538
Ref: library/email compat32-message email message Message set_boundary12339902
Ref: 3b7a12339902
Ref: library/email compat32-message email message Message get_content_charset12340717
Ref: 3b7b12340717
Ref: library/email compat32-message email message Message get_charsets12341205
Ref: 3b7c12341205
Ref: library/email compat32-message email message Message get_content_disposition12341907
Ref: ffa12341907
Ref: library/email compat32-message email message Message walk12342272
Ref: 3b7d12342272
Ref: library/email compat32-message email message Message preamble12344392
Ref: 3b7e12344392
Ref: library/email compat32-message email message Message epilogue12345656
Ref: 3b7f12345656
Ref: library/email compat32-message email message Message defects12346055
Ref: 3b8012346055
Ref: email message Message Representing an email message using the compat32 API-Footnote-112346333
Ref: email message Message Representing an email message using the compat32 API-Footnote-212346392
Ref: email message Message Representing an email message using the compat32 API-Footnote-312346451
Ref: email message Message Representing an email message using the compat32 API-Footnote-412346510
Ref: email message Message Representing an email message using the compat32 API-Footnote-512346569
Ref: email message Message Representing an email message using the compat32 API-Footnote-612346628
Ref: email message Message Representing an email message using the compat32 API-Footnote-712346687
Ref: email message Message Representing an email message using the compat32 API-Footnote-812346746
Ref: email message Message Representing an email message using the compat32 API-Footnote-912346805
Ref: email message Message Representing an email message using the compat32 API-Footnote-1012346864
Ref: email message Message Representing an email message using the compat32 API-Footnote-1112346924
Ref: email message Message Representing an email message using the compat32 API-Footnote-1212346984
Node: email mime Creating email and MIME objects from scratch12347044
Ref: library/email mime doc12347310
Ref: 3b8112347310
Ref: library/email mime email-mime-creating-email-and-mime-objects-from-scratch12347310
Ref: 3b8212347310
Ref: library/email mime module-email mime12347310
Ref: 4912347310
Ref: library/email mime translation-repo12347310
Ref: 3b8312347310
Ref: library/email mime module-email mime base12348546
Ref: 4c12348546
Ref: library/email mime email mime base MIMEBase12348546
Ref: 3b8412348546
Ref: library/email mime module-email mime nonmultipart12349701
Ref: 5012349701
Ref: library/email mime email mime nonmultipart MIMENonMultipart12349701
Ref: 3b1912349701
Ref: library/email mime module-email mime multipart12350199
Ref: 4f12350199
Ref: library/email mime email mime multipart MIMEMultipart12350199
Ref: 3b8512350199
Ref: library/email mime module-email mime application12351524
Ref: 4a12351524
Ref: library/email mime email mime application MIMEApplication12351524
Ref: 3b8612351524
Ref: library/email mime module-email mime audio12352886
Ref: 4b12352886
Ref: library/email mime email mime audio MIMEAudio12352886
Ref: 3b8712352886
Ref: library/email mime module-email mime image12354460
Ref: 4d12354460
Ref: library/email mime email mime image MIMEImage12354460
Ref: 3b1a12354460
Ref: library/email mime module-email mime message12356114
Ref: 4e12356114
Ref: library/email mime email mime message MIMEMessage12356114
Ref: 3b8812356114
Ref: library/email mime module-email mime text12356810
Ref: 5112356810
Ref: library/email mime email mime text MIMEText12356810
Ref: ffc12356810
Ref: email mime Creating email and MIME objects from scratch-Footnote-112358463
Node: email header Internationalized headers12358531
Ref: library/email header doc12358764
Ref: 3b8912358764
Ref: library/email header email-header-internationalized-headers12358764
Ref: 3b8a12358764
Ref: library/email header module-email header12358764
Ref: 4512358764
Ref: library/email header translation-repo12358764
Ref: 3b8b12358764
Ref: library/email header email header Header12361461
Ref: 1c4612361461
Ref: library/email header email header Header append12363334
Ref: 3b8c12363334
Ref: library/email header email header Header encode12364668
Ref: 3b8d12364668
Ref: library/email header email header Header __str__12366312
Ref: 3b8e12366312
Ref: library/email header email header Header __eq__12366816
Ref: 3b8f12366816
Ref: library/email header email header Header __ne__12366952
Ref: 3b9012366952
Ref: library/email header email header decode_header12367176
Ref: 12c012367176
Ref: library/email header email header make_header12368642
Ref: 12c112368642
Ref: email header Internationalized headers-Footnote-112369467
Ref: email header Internationalized headers-Footnote-212369539
Ref: email header Internationalized headers-Footnote-312369598
Ref: email header Internationalized headers-Footnote-412369656
Ref: email header Internationalized headers-Footnote-512369715
Ref: email header Internationalized headers-Footnote-612369774
Ref: email header Internationalized headers-Footnote-712369833
Ref: email header Internationalized headers-Footnote-812369892
Ref: email header Internationalized headers-Footnote-912369951
Ref: email header Internationalized headers-Footnote-1012370010
Ref: email header Internationalized headers-Footnote-1112370070
Ref: email header Internationalized headers-Footnote-1212370130
Ref: email header Internationalized headers-Footnote-1312370190
Ref: email header Internationalized headers-Footnote-1412370250
Ref: email header Internationalized headers-Footnote-1512370310
Node: email charset Representing character sets12370370
Ref: library/email charset doc12370571
Ref: 3b9112370571
Ref: library/email charset email-charset-representing-character-sets12370571
Ref: 3b9212370571
Ref: library/email charset module-email charset12370571
Ref: 4012370571
Ref: library/email charset translation-repo12370571
Ref: 3b9312370571
Ref: library/email charset email charset Charset12371382
Ref: ffd12371382
Ref: library/email charset email charset Charset input_charset12372908
Ref: 3b9412372908
Ref: library/email charset email charset Charset header_encoding12373164
Ref: 3b9512373164
Ref: library/email charset email charset Charset body_encoding12373550
Ref: 3b9612373550
Ref: library/email charset email charset Charset output_charset12373827
Ref: 3b9712373827
Ref: library/email charset email charset Charset input_codec12374166
Ref: 3b9812374166
Ref: library/email charset email charset Charset output_codec12374380
Ref: 3b9912374380
Ref: library/email charset email charset Charset get_body_encoding12374692
Ref: 3b9a12374692
Ref: library/email charset email charset Charset get_output_charset12375409
Ref: 3b9b12375409
Ref: library/email charset email charset Charset header_encode12375613
Ref: 3b9c12375613
Ref: library/email charset email charset Charset header_encode_lines12375821
Ref: 3b9d12375821
Ref: library/email charset email charset Charset body_encode12376254
Ref: 3b9e12376254
Ref: library/email charset email charset Charset __str__12376586
Ref: 3b9f12376586
Ref: library/email charset email charset Charset __eq__12376745
Ref: 3ba012376745
Ref: library/email charset email charset Charset __ne__12376881
Ref: 3ba112376881
Ref: library/email charset email charset add_charset12377175
Ref: 3ba212377175
Ref: library/email charset email charset add_alias12378500
Ref: 3ba412378500
Ref: library/email charset email charset add_codec12378826
Ref: 3ba312378826
Ref: email charset Representing character sets-Footnote-112379220
Node: email encoders Encoders12379293
Ref: library/email encoders doc12379491
Ref: 3ba512379491
Ref: library/email encoders email-encoders-encoders12379491
Ref: 3ba612379491
Ref: library/email encoders module-email encoders12379491
Ref: 4212379491
Ref: library/email encoders translation-repo12379491
Ref: 3ba712379491
Ref: library/email encoders email encoders encode_quopri12381183
Ref: 3ba812381183
Ref: library/email encoders email encoders encode_base6412381511
Ref: 3ba912381511
Ref: library/email encoders email encoders encode_7or8bit12381907
Ref: 3baa12381907
Ref: library/email encoders email encoders encode_noop12382167
Ref: 3bab12382167
Ref: email encoders Encoders-Footnote-112382347
Ref: email encoders Encoders-Footnote-212382421
Node: email utils Miscellaneous utilities12382538
Ref: library/email utils doc12382720
Ref: 3bac12382720
Ref: library/email utils email-utils-miscellaneous-utilities12382720
Ref: 3bad12382720
Ref: library/email utils module-email utils12382720
Ref: 5412382720
Ref: library/email utils translation-repo12382720
Ref: 3bae12382720
Ref: library/email utils email utils localtime12383016
Ref: 2f712383016
Ref: library/email utils email utils make_msgid12383560
Ref: 3baf12383560
Ref: library/email utils email utils quote12384462
Ref: 3bb012384462
Ref: library/email utils email utils unquote12384641
Ref: 3abd12384641
Ref: library/email utils email utils parseaddr12384911
Ref: 4f512384911
Ref: library/email utils email utils formataddr12385483
Ref: 13a212385483
Ref: library/email utils email utils getaddresses12386168
Ref: 4f412386168
Ref: library/email utils email utils parsedate12387019
Ref: 3bb112387019
Ref: library/email utils email utils parsedate_tz12387649
Ref: 1c0b12387649
Ref: library/email utils email utils parsedate_to_datetime12388229
Ref: 12c612388229
Ref: library/email utils email utils mktime_tz12389111
Ref: 3bb212389111
Ref: library/email utils email utils formatdate12389348
Ref: 167112389348
Ref: library/email utils email utils format_datetime12390295
Ref: 12c512390295
Ref: library/email utils email utils decode_rfc223112390983
Ref: 3bb312390983
Ref: library/email utils email utils encode_rfc223112391083
Ref: 3bb412391083
Ref: library/email utils email utils collapse_rfc2231_value12391491
Ref: 3b7512391491
Ref: library/email utils email utils decode_params12392345
Ref: 180c12392345
Ref: email utils Miscellaneous utilities-Footnote-112392601
Ref: email utils Miscellaneous utilities-Footnote-212392672
Ref: email utils Miscellaneous utilities-Footnote-312392731
Ref: email utils Miscellaneous utilities-Footnote-412392790
Ref: email utils Miscellaneous utilities-Footnote-512392849
Ref: email utils Miscellaneous utilities-Footnote-612392908
Ref: email utils Miscellaneous utilities-Footnote-712393181
Ref: email utils Miscellaneous utilities-Footnote-812393240
Ref: email utils Miscellaneous utilities-Footnote-912393299
Ref: email utils Miscellaneous utilities-Footnote-1012393358
Ref: email utils Miscellaneous utilities-Footnote-1112393418
Ref: email utils Miscellaneous utilities-Footnote-1212393478
Node: email iterators Iterators12393538
Ref: library/email iterators doc12393688
Ref: 3bb512393688
Ref: library/email iterators email-iterators-iterators12393688
Ref: 3bb612393688
Ref: library/email iterators module-email iterators12393688
Ref: 4712393688
Ref: library/email iterators translation-repo12393688
Ref: 3bb712393688
Ref: library/email iterators email iterators body_line_iterator12394088
Ref: 3bb812394088
Ref: library/email iterators email iterators typed_subpart_iterator12394666
Ref: 3bb912394666
Ref: library/email iterators email iterators _structure12395384
Ref: 3bba12395384
Ref: email iterators Iterators-Footnote-112396810
Node: json — JSON encoder and decoder12396886
Ref: library/json doc12397091
Ref: 3bbb12397091
Ref: library/json json-json-encoder-and-decoder12397091
Ref: 3bbc12397091
Ref: library/json module-json12397091
Ref: 8612397091
Ref: library/json translation-repo12397091
Ref: 3bbd12397091
Ref: json — JSON encoder and decoder-Footnote-112401732
Ref: json — JSON encoder and decoder-Footnote-212401805
Ref: json — JSON encoder and decoder-Footnote-312401830
Ref: json — JSON encoder and decoder-Footnote-412401889
Ref: json — JSON encoder and decoder-Footnote-512401948
Ref: json — JSON encoder and decoder-Footnote-612402035
Ref: json — JSON encoder and decoder-Footnote-712402084
Ref: json — JSON encoder and decoder-Footnote-812402346
Node: Basic Usage12402372
Ref: library/json basic-usage12402483
Ref: 3bbe12402483
Ref: library/json json dump12402526
Ref: f4212402526
Ref: library/json json dumps12406919
Ref: f4312406919
Ref: library/json json load12407744
Ref: eb412407744
Ref: library/json json loads12411411
Ref: b5012411411
Ref: Basic Usage-Footnote-112412132
Node: Encoders and Decoders12412164
Ref: library/json encoders-and-decoders12412298
Ref: 3bc212412298
Ref: library/json json JSONDecoder12412361
Ref: f4512412361
Ref: library/json json-to-py-table12412616
Ref: 3bc112412616
Ref: library/json json JSONDecoder decode12415610
Ref: 3bc312415610
Ref: library/json json JSONDecoder raw_decode12415863
Ref: 3bc412415863
Ref: library/json json JSONEncoder12416227
Ref: f4412416227
Ref: library/json py-to-json-table12416529
Ref: 3bbf12416529
Ref: library/json json JSONEncoder default12421039
Ref: 3bc012421039
Ref: library/json json JSONEncoder encode12421728
Ref: 3bc512421728
Ref: library/json json JSONEncoder iterencode12421973
Ref: 3bc612421973
Ref: Encoders and Decoders-Footnote-112422270
Node: Exceptions<19>12422302
Ref: library/json exceptions12422465
Ref: 3bc712422465
Ref: library/json json JSONDecodeError12422506
Ref: 102412422506
Ref: library/json json JSONDecodeError msg12422647
Ref: 3bc812422647
Ref: library/json json JSONDecodeError doc12422714
Ref: 3bc912422714
Ref: library/json json JSONDecodeError pos12422782
Ref: 3bca12422782
Ref: library/json json JSONDecodeError lineno12422865
Ref: 3bcb12422865
Ref: library/json json JSONDecodeError colno12422937
Ref: 3bcc12422937
Node: Standard Compliance and Interoperability12423038
Ref: library/json standard-compliance-and-interoperability12423205
Ref: 3bcd12423205
Ref: Standard Compliance and Interoperability-Footnote-112424355
Ref: Standard Compliance and Interoperability-Footnote-212424414
Node: Character Encodings12424501
Ref: library/json character-encodings12424636
Ref: 3bce12424636
Node: Infinite and NaN Number Values12425977
Ref: library/json infinite-and-nan-number-values12426152
Ref: 3bcf12426152
Node: Repeated Names Within an Object12426940
Ref: library/json repeated-names-within-an-object12427133
Ref: 3bd012427133
Node: Top-level Non-Object Non-Array Values12427656
Ref: library/json top-level-non-object-non-array-values12427845
Ref: 3bd112427845
Ref: Top-level Non-Object Non-Array Values-Footnote-112428499
Ref: Top-level Non-Object Non-Array Values-Footnote-212428558
Node: Implementation Limitations12428617
Ref: library/json implementation-limitations12428766
Ref: 3bd212428766
Node: Command-line interface<5>12429714
Ref: library/json command-line-interface12429858
Ref: 3bd312429858
Ref: library/json json-commandline12429858
Ref: 23e12429858
Ref: library/json module-json tool12429858
Ref: 8712429858
Ref: Command-line interface<5>-Footnote-112431055
Node: Command-line options<4>12431124
Ref: library/json command-line-options12431209
Ref: 3bd512431209
Ref: library/json cmdoption-json-arg-infile12431272
Ref: 3bd612431272
Ref: library/json cmdoption-json-arg-outfile12431743
Ref: 3bd712431743
Ref: library/json cmdoption-json-sort-keys12431878
Ref: 3bd412431878
Ref: library/json cmdoption-json-no-ensure-ascii12431992
Ref: 3bd812431992
Ref: library/json cmdoption-json-json-lines12432155
Ref: 3bd912432155
Ref: library/json cmdoption-json-indent12432263
Ref: 3bda12432263
Ref: library/json cmdoption-json-tab12432263
Ref: 3bdb12432263
Ref: library/json cmdoption-json-no-indent12432263
Ref: 3bdc12432263
Ref: library/json cmdoption-json-compact12432263
Ref: 3bdd12432263
Ref: library/json cmdoption-json-h12432401
Ref: 3bde12432401
Ref: library/json cmdoption-json-help12432401
Ref: 3bdf12432401
Node: mailbox — Manipulate mailboxes in various formats12432454
Ref: library/mailbox doc12432656
Ref: 3be012432656
Ref: library/mailbox mailbox-manipulate-mailboxes-in-various-formats12432656
Ref: 3be112432656
Ref: library/mailbox module-mailbox12432656
Ref: 8f12432656
Ref: library/mailbox translation-repo12432656
Ref: 3be212432656
Ref: mailbox — Manipulate mailboxes in various formats-Footnote-112433542
Node: Mailbox objects12433609
Ref: library/mailbox id112433736
Ref: 3be312433736
Ref: library/mailbox mailbox-objects12433736
Ref: 3be412433736
Ref: library/mailbox mailbox Mailbox12433795
Ref: 145412433795
Ref: library/mailbox mailbox Mailbox add12436590
Ref: 145312436590
Ref: library/mailbox mailbox Mailbox remove12437398
Ref: 3be512437398
Ref: library/mailbox mailbox Mailbox __delitem__12437428
Ref: 3be912437428
Ref: library/mailbox mailbox Mailbox discard12437463
Ref: 3be612437463
Ref: library/mailbox mailbox Mailbox __setitem__12438008
Ref: 3bea12438008
Ref: library/mailbox mailbox Mailbox iterkeys12438894
Ref: 3beb12438894
Ref: library/mailbox mailbox Mailbox keys12438980
Ref: 3bec12438980
Ref: library/mailbox mailbox Mailbox itervalues12439142
Ref: 3bed12439142
Ref: library/mailbox mailbox Mailbox __iter__12439173
Ref: 3bee12439173
Ref: library/mailbox mailbox Mailbox values12439660
Ref: 3bef12439660
Ref: library/mailbox mailbox Mailbox iteritems12439826
Ref: 3bf012439826
Ref: library/mailbox mailbox Mailbox items12440247
Ref: 3bf112440247
Ref: library/mailbox mailbox Mailbox get12440440
Ref: 3bf212440440
Ref: library/mailbox mailbox Mailbox __getitem__12440481
Ref: 3bf312440481
Ref: library/mailbox mailbox Mailbox get_message12441056
Ref: 3bf412441056
Ref: library/mailbox mailbox Mailbox get_bytes12441345
Ref: 145612441345
Ref: library/mailbox mailbox Mailbox get_string12441580
Ref: 145712441580
Ref: library/mailbox mailbox Mailbox get_file12441919
Ref: 145512441919
Ref: library/mailbox mailbox Mailbox __contains__12442955
Ref: 3bf512442955
Ref: library/mailbox mailbox Mailbox __len__12443089
Ref: 3bf612443089
Ref: library/mailbox mailbox Mailbox clear12443172
Ref: 3bf712443172
Ref: library/mailbox mailbox Mailbox pop12443248
Ref: 3bf812443248
Ref: library/mailbox mailbox Mailbox popitem12443686
Ref: 3bf912443686
Ref: library/mailbox mailbox Mailbox update12444202
Ref: 3bfa12444202
Ref: library/mailbox mailbox Mailbox flush12444904
Ref: 19a912444904
Ref: library/mailbox mailbox Mailbox lock12445189
Ref: 3be712445189
Ref: library/mailbox mailbox Mailbox unlock12445608
Ref: 3be812445608
Ref: library/mailbox mailbox Mailbox close12445688
Ref: 3bfc12445688
Node: Maildir objects12445974
Ref: library/mailbox mailbox-maildir12446062
Ref: 3bfd12446062
Ref: library/mailbox maildir-objects12446062
Ref: 3bfe12446062
Ref: library/mailbox mailbox Maildir12446121
Ref: 65e12446121
Ref: library/mailbox mailbox Maildir colon12448249
Ref: 3c0012448249
Ref: library/mailbox mailbox Maildir list_folders12449068
Ref: 3c0112449068
Ref: library/mailbox mailbox Maildir get_folder12449156
Ref: 3c0212449156
Ref: library/mailbox mailbox Maildir add_folder12449390
Ref: 3c0412449390
Ref: library/mailbox mailbox Maildir remove_folder12449541
Ref: 3c0512449541
Ref: library/mailbox mailbox Maildir clean12449783
Ref: 3c0712449783
Ref: library/mailbox mailbox Maildir get_flags12450019
Ref: 1a2e12450019
Ref: library/mailbox mailbox Maildir set_flags12450824
Ref: 1a2f12450824
Ref: library/mailbox mailbox Maildir add_flag12451575
Ref: 1a3012451575
Ref: library/mailbox mailbox Maildir remove_flag12452087
Ref: 1a3112452087
Ref: library/mailbox mailbox Maildir get_info12452610
Ref: 1a2c12452610
Ref: library/mailbox mailbox Maildir set_info12453340
Ref: 1a2d12453340
Ref: library/mailbox mailbox Maildir add12454138
Ref: 3c0f12454138
Ref: library/mailbox mailbox Maildir __setitem__12454169
Ref: 3c0c12454169
Ref: library/mailbox mailbox Maildir update12454213
Ref: 3c1012454213
Ref: library/mailbox mailbox Maildir flush12454631
Ref: 3c1112454631
Ref: library/mailbox mailbox Maildir lock12454766
Ref: 3c1212454766
Ref: library/mailbox mailbox Maildir unlock12454791
Ref: 3c1312454791
Ref: library/mailbox mailbox Maildir close12454924
Ref: 3c1412454924
Ref: library/mailbox mailbox Maildir get_file12455115
Ref: 3c1512455115
Ref: Maildir objects-Footnote-112455653
Ref: Maildir objects-Footnote-212455702
Node: mbox objects12455746
Ref: library/mailbox mailbox-mbox12455853
Ref: 3c1612455853
Ref: library/mailbox mbox-objects12455853
Ref: 3c1712455853
Ref: library/mailbox mailbox mbox12455906
Ref: 19e312455906
Ref: library/mailbox mailbox mbox get_bytes12457316
Ref: 3c1812457316
Ref: library/mailbox mailbox mbox get_file12457611
Ref: 3c1912457611
Ref: library/mailbox mailbox mbox get_string12458092
Ref: 3c1a12458092
Ref: library/mailbox mailbox mbox lock12458388
Ref: 3c1b12458388
Ref: library/mailbox mailbox mbox unlock12458413
Ref: 3c1c12458413
Ref: mbox objects-Footnote-112458994
Ref: mbox objects-Footnote-212459054
Ref: mbox objects-Footnote-312459106
Node: MH objects12459184
Ref: library/mailbox mailbox-mh12459289
Ref: 3c1d12459289
Ref: library/mailbox mh-objects12459289
Ref: 3c1e12459289
Ref: library/mailbox mailbox MH12459338
Ref: 1a1512459338
Ref: library/mailbox mailbox MH list_folders12460881
Ref: 3c2012460881
Ref: library/mailbox mailbox MH get_folder12460969
Ref: 3c2112460969
Ref: library/mailbox mailbox MH add_folder12461199
Ref: 3c2212461199
Ref: library/mailbox mailbox MH remove_folder12461346
Ref: 3c2312461346
Ref: library/mailbox mailbox MH get_sequences12461588
Ref: 3c2412461588
Ref: library/mailbox mailbox MH set_sequences12461765
Ref: 3c2512461765
Ref: library/mailbox mailbox MH pack12462003
Ref: 3c2612462003
Ref: library/mailbox mailbox MH remove12462418
Ref: 3c2712462418
Ref: library/mailbox mailbox MH __delitem__12462448
Ref: 3c2812462448
Ref: library/mailbox mailbox MH discard12462483
Ref: 3c2912462483
Ref: library/mailbox mailbox MH lock12462692
Ref: 3c2a12462692
Ref: library/mailbox mailbox MH unlock12462717
Ref: 3c2b12462717
Ref: library/mailbox mailbox MH get_file12463092
Ref: 3c2c12463092
Ref: library/mailbox mailbox MH flush12463284
Ref: 3c2d12463284
Ref: library/mailbox mailbox MH close12463414
Ref: 3c2e12463414
Ref: MH objects-Footnote-112463878
Ref: MH objects-Footnote-212463914
Node: Babyl objects12463959
Ref: library/mailbox babyl-objects12464064
Ref: 3c2f12464064
Ref: library/mailbox mailbox-babyl12464064
Ref: 3c3012464064
Ref: library/mailbox mailbox Babyl12464119
Ref: 3c3112464119
Ref: library/mailbox mailbox Babyl get_labels12465684
Ref: 3c3312465684
Ref: library/mailbox mailbox Babyl get_file12466211
Ref: 3c3412466211
Ref: library/mailbox mailbox Babyl lock12466742
Ref: 3c3512466742
Ref: library/mailbox mailbox Babyl unlock12466767
Ref: 3c3612466767
Ref: Babyl objects-Footnote-112467165
Ref: Babyl objects-Footnote-212467209
Node: MMDF objects12467287
Ref: library/mailbox mailbox-mmdf12467373
Ref: 3c3712467373
Ref: library/mailbox mmdf-objects12467373
Ref: 3c3812467373
Ref: library/mailbox mailbox MMDF12467426
Ref: 19e412467426
Ref: library/mailbox mailbox MMDF get_bytes12468679
Ref: 3c3a12468679
Ref: library/mailbox mailbox MMDF get_file12468974
Ref: 3c3b12468974
Ref: library/mailbox mailbox MMDF lock12469455
Ref: 3c3c12469455
Ref: library/mailbox mailbox MMDF unlock12469480
Ref: 3c3d12469480
Ref: MMDF objects-Footnote-112469921
Ref: MMDF objects-Footnote-212469981
Node: Message objects12470024
Ref: library/mailbox mailbox-message-objects12470174
Ref: 3c3e12470174
Ref: library/mailbox message-objects12470174
Ref: 3c3f12470174
Ref: library/mailbox mailbox Message12470233
Ref: 145812470233
Ref: Message objects-Footnote-112472279
Node: MaildirMessage objects12472338
Ref: library/mailbox mailbox-maildirmessage12472440
Ref: 3c4012472440
Ref: library/mailbox maildirmessage-objects12472440
Ref: 3c4112472440
Ref: library/mailbox mailbox MaildirMessage12472513
Ref: 3bff12472513
Ref: library/mailbox mailbox MaildirMessage get_subdir12474352
Ref: 3c4212474352
Ref: library/mailbox mailbox MaildirMessage set_subdir12474862
Ref: 3c4312474862
Ref: library/mailbox mailbox MaildirMessage get_flags12475029
Ref: 3c0812475029
Ref: library/mailbox mailbox MaildirMessage set_flags12475499
Ref: 3c0912475499
Ref: library/mailbox mailbox MaildirMessage add_flag12475603
Ref: 3c0a12475603
Ref: library/mailbox mailbox MaildirMessage remove_flag12475951
Ref: 3c0b12475951
Ref: library/mailbox mailbox MaildirMessage get_date12476302
Ref: 3c4412476302
Ref: library/mailbox mailbox MaildirMessage set_date12476458
Ref: 3c4512476458
Ref: library/mailbox mailbox MaildirMessage get_info12476623
Ref: 3c0d12476623
Ref: library/mailbox mailbox MaildirMessage set_info12476842
Ref: 3c0e12476842
Node: mboxMessage objects12479607
Ref: library/mailbox mailbox-mboxmessage12479735
Ref: 3c4612479735
Ref: library/mailbox mboxmessage-objects12479735
Ref: 3c4712479735
Ref: library/mailbox mailbox mboxMessage12479802
Ref: 3aa512479802
Ref: library/mailbox mailbox mboxMessage get_from12481587
Ref: 3c4812481587
Ref: library/mailbox mailbox mboxMessage set_from12481814
Ref: 3c4912481814
Ref: library/mailbox mailbox mboxMessage get_flags12482348
Ref: 3c4a12482348
Ref: library/mailbox mailbox mboxMessage set_flags12482696
Ref: 3c4b12482696
Ref: library/mailbox mailbox mboxMessage add_flag12482987
Ref: 3c4c12482987
Ref: library/mailbox mailbox mboxMessage remove_flag12483207
Ref: 3c4d12483207
Node: MHMessage objects12486163
Ref: library/mailbox mailbox-mhmessage12486289
Ref: 3c4e12486289
Ref: library/mailbox mhmessage-objects12486289
Ref: 3c4f12486289
Ref: library/mailbox mailbox MHMessage12486354
Ref: 3c1f12486354
Ref: library/mailbox mailbox MHMessage get_sequences12487315
Ref: 3c5012487315
Ref: library/mailbox mailbox MHMessage set_sequences12487438
Ref: 3c5112487438
Ref: library/mailbox mailbox MHMessage add_sequence12487546
Ref: 3c5212487546
Ref: library/mailbox mailbox MHMessage remove_sequence12487676
Ref: 3c5312487676
Node: BabylMessage objects12489521
Ref: library/mailbox babylmessage-objects12489647
Ref: 3c5412489647
Ref: library/mailbox mailbox-babylmessage12489647
Ref: 3c5512489647
Ref: library/mailbox mailbox BabylMessage12489718
Ref: 3c3212489718
Ref: library/mailbox mailbox BabylMessage get_labels12491074
Ref: 3c5612491074
Ref: library/mailbox mailbox BabylMessage set_labels12491157
Ref: 3c5712491157
Ref: library/mailbox mailbox BabylMessage add_label12491257
Ref: 3c5812491257
Ref: library/mailbox mailbox BabylMessage remove_label12491354
Ref: 3c5912491354
Ref: library/mailbox mailbox BabylMessage get_visible12491459
Ref: 3c5a12491459
Ref: library/mailbox mailbox BabylMessage set_visible12491627
Ref: 3c5b12491627
Ref: library/mailbox mailbox BabylMessage update_visible12491978
Ref: 3c5c12491978
Node: MMDFMessage objects12494396
Ref: library/mailbox mailbox-mmdfmessage12494496
Ref: 3c5d12494496
Ref: library/mailbox mmdfmessage-objects12494496
Ref: 3c5e12494496
Ref: library/mailbox mailbox MMDFMessage12494565
Ref: 3c3912494565
Ref: library/mailbox mailbox MMDFMessage get_from12496234
Ref: 3c5f12496234
Ref: library/mailbox mailbox MMDFMessage set_from12496461
Ref: 3c6012496461
Ref: library/mailbox mailbox MMDFMessage get_flags12496995
Ref: 3c6112496995
Ref: library/mailbox mailbox MMDFMessage set_flags12497343
Ref: 3c6212497343
Ref: library/mailbox mailbox MMDFMessage add_flag12497634
Ref: 3c6312497634
Ref: library/mailbox mailbox MMDFMessage remove_flag12497854
Ref: 3c6412497854
Node: Exceptions<20>12500811
Ref: library/mailbox exceptions12500958
Ref: 3c6512500958
Ref: library/mailbox mailbox Error12501075
Ref: 3c6612501075
Ref: library/mailbox mailbox NoSuchMailboxError12501169
Ref: 3c0312501169
Ref: library/mailbox mailbox NotEmptyError12501476
Ref: 3c0612501476
Ref: library/mailbox mailbox ExternalClashError12501638
Ref: 3bfb12501638
Ref: library/mailbox mailbox FormatError12501951
Ref: 3c6712501951
Node: Examples<24>12502148
Ref: library/mailbox examples12502271
Ref: 3c6812502271
Ref: library/mailbox mailbox-examples12502271
Ref: 3c6912502271
Node: mimetypes — Map filenames to MIME types12504549
Ref: library/mimetypes doc12504771
Ref: 3c6a12504771
Ref: library/mimetypes mimetypes-map-filenames-to-mime-types12504771
Ref: 3c6b12504771
Ref: library/mimetypes module-mimetypes12504771
Ref: 9312504771
Ref: library/mimetypes translation-repo12504771
Ref: 3c6c12504771
Ref: library/mimetypes mimetypes guess_type12505658
Ref: 51812505658
Ref: library/mimetypes mimetypes guess_file_type12507368
Ref: 51712507368
Ref: library/mimetypes mimetypes guess_all_extensions12507699
Ref: 1c3212507699
Ref: library/mimetypes mimetypes guess_extension12508296
Ref: 3c6e12508296
Ref: library/mimetypes mimetypes init12509037
Ref: 3c6d12509037
Ref: library/mimetypes mimetypes read_mime_types12510018
Ref: 1d1212510018
Ref: library/mimetypes mimetypes add_type12510395
Ref: 3c7012510395
Ref: library/mimetypes mimetypes inited12510852
Ref: 3c7112510852
Ref: library/mimetypes mimetypes knownfiles12511022
Ref: 3c6f12511022
Ref: library/mimetypes mimetypes suffix_map12511232
Ref: 3c7212511232
Ref: library/mimetypes mimetypes encodings_map12511582
Ref: 3c7312511582
Ref: library/mimetypes mimetypes types_map12511681
Ref: 3c7412511681
Ref: library/mimetypes mimetypes common_types12511772
Ref: 3c7512511772
Ref: mimetypes — Map filenames to MIME types-Footnote-112512408
Ref: mimetypes — Map filenames to MIME types-Footnote-212512477
Node: MimeTypes objects12512548
Ref: library/mimetypes id112512673
Ref: 3c7612512673
Ref: library/mimetypes mimetypes-objects12512673
Ref: 3c7712512673
Ref: library/mimetypes mimetypes MimeTypes12512922
Ref: 170212512922
Ref: library/mimetypes mimetypes MimeTypes suffix_map12513607
Ref: 3c7a12513607
Ref: library/mimetypes mimetypes MimeTypes encodings_map12514089
Ref: 3c7b12514089
Ref: library/mimetypes mimetypes MimeTypes types_map12514302
Ref: 3c7c12514302
Ref: library/mimetypes mimetypes MimeTypes types_map_inv12514638
Ref: 3c7d12514638
Ref: library/mimetypes mimetypes MimeTypes guess_extension12514988
Ref: 3c7e12514988
Ref: library/mimetypes mimetypes MimeTypes guess_type12515166
Ref: 1e0112515166
Ref: library/mimetypes mimetypes MimeTypes guess_file_type12515332
Ref: 3c7f12515332
Ref: library/mimetypes mimetypes MimeTypes guess_all_extensions12515546
Ref: 3c8012515546
Ref: library/mimetypes mimetypes MimeTypes read12515734
Ref: 3c7812515734
Ref: library/mimetypes mimetypes MimeTypes readfp12516047
Ref: 3c7912516047
Ref: library/mimetypes mimetypes MimeTypes read_windows_registry12516378
Ref: 3c8112516378
Ref: library/mimetypes mimetypes MimeTypes add_type12516722
Ref: 31912516722
Node: Command-line usage<4>12517452
Ref: library/mimetypes command-line-usage12517609
Ref: 3c8212517609
Ref: library/mimetypes mimetypes-cli12517609
Ref: 24712517609
Ref: library/mimetypes cmdoption-mimetypes-h12517839
Ref: 3c8312517839
Ref: library/mimetypes cmdoption-mimetypes-help12517869
Ref: 3c8412517869
Ref: library/mimetypes cmdoption-mimetypes-e12517942
Ref: 3c8512517942
Ref: library/mimetypes cmdoption-mimetypes-extension12517972
Ref: 3c8612517972
Ref: library/mimetypes cmdoption-mimetypes-l12518051
Ref: 3c8712518051
Ref: library/mimetypes cmdoption-mimetypes-lenient12518081
Ref: 3c8812518081
Node: Command-line example<2>12518549
Ref: library/mimetypes command-line-example12518680
Ref: 3c8912518680
Node: base64 — Base16 Base32 Base64 Base85 Data Encodings12520298
Ref: library/base64 doc12520514
Ref: 3c8a12520514
Ref: library/base64 base64-base16-base32-base64-base85-data-encodings12520514
Ref: 3c8b12520514
Ref: library/base64 module-base6412520514
Ref: f12520514
Ref: library/base64 translation-repo12520514
Ref: 3c8c12520514
Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-112522237
Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-212522303
Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-312522362
Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-412522421
Ref: base64 — Base16 Base32 Base64 Base85 Data Encodings-Footnote-512522480
Node: RFC 4648 Encodings12522539
Ref: library/base64 base64-rfc-464812522672
Ref: 3c8d12522672
Ref: library/base64 rfc-4648-encodings12522672
Ref: 3c9012522672
Ref: library/base64 base64 b64encode12522902
Ref: 3c9112522902
Ref: library/base64 base64 b64decode12523586
Ref: 1d7812523586
Ref: library/base64 base64 standard_b64encode12524578
Ref: 3c9212524578
Ref: library/base64 base64 standard_b64decode12524751
Ref: 3c9312524751
Ref: library/base64 base64 urlsafe_b64encode12524940
Ref: 3c9412524940
Ref: library/base64 base64 urlsafe_b64decode12525280
Ref: 3c9512525280
Ref: library/base64 base64 b32encode12525597
Ref: 3c9612525597
Ref: library/base64 base64 b32decode12525743
Ref: 122712525743
Ref: library/base64 base64 b32hexencode12526739
Ref: 9e612526739
Ref: library/base64 base64 b32hexdecode12526917
Ref: 9e712526917
Ref: library/base64 base64 b16encode12527366
Ref: 3c9712527366
Ref: library/base64 base64 b16decode12527512
Ref: 2d312527512
Ref: RFC 4648 Encodings-Footnote-112528037
Ref: RFC 4648 Encodings-Footnote-212528096
Ref: RFC 4648 Encodings-Footnote-312528155
Ref: RFC 4648 Encodings-Footnote-412528214
Node: Base85 Encodings12528273
Ref: library/base64 base64-base-8512528431
Ref: 3c8e12528431
Ref: library/base64 base85-encodings12528431
Ref: 3c9812528431
Ref: library/base64 base64 a85encode12529208
Ref: 112212529208
Ref: library/base64 base64 a85decode12530208
Ref: 112312530208
Ref: library/base64 base64 b85encode12531039
Ref: 112412531039
Ref: library/base64 base64 b85decode12531393
Ref: 112512531393
Ref: library/base64 base64 z85encode12531636
Ref: 47b12531636
Ref: library/base64 base64 z85decode12531881
Ref: 47c12531881
Ref: Base85 Encodings-Footnote-112532160
Ref: Base85 Encodings-Footnote-212532200
Node: Legacy Interface12532240
Ref: library/base64 base64-legacy12532406
Ref: 3c8f12532406
Ref: library/base64 legacy-interface12532406
Ref: 3c9912532406
Ref: library/base64 base64 decode12532459
Ref: 3c9a12532459
Ref: library/base64 base64 decodebytes12532768
Ref: b4f12532768
Ref: library/base64 base64 encode12532998
Ref: 3c9b12532998
Ref: library/base64 base64 encodebytes12533518
Ref: b4e12533518
Ref: Legacy Interface-Footnote-112534190
Ref: Legacy Interface-Footnote-212534249
Node: Security Considerations<2>12534308
Ref: library/base64 base64-security12534449
Ref: 3c9c12534449
Ref: library/base64 security-considerations12534449
Ref: 3c9d12534449
Ref: Security Considerations<2>-Footnote-112535113
Ref: Security Considerations<2>-Footnote-212535172
Node: binascii — Convert between binary and ASCII12535231
Ref: library/binascii doc12535461
Ref: 3c9e12535461
Ref: library/binascii binascii-convert-between-binary-and-ascii12535461
Ref: 3c9f12535461
Ref: library/binascii module-binascii12535461
Ref: 1112535461
Ref: library/binascii translation-repo12535461
Ref: 3ca012535461
Ref: library/binascii binascii a2b_uu12536468
Ref: 3ca112536468
Ref: library/binascii binascii b2a_uu12536718
Ref: d1812536718
Ref: library/binascii binascii a2b_base6412537102
Ref: 198c12537102
Ref: library/binascii binascii b2a_base6412537773
Ref: e7d12537773
Ref: library/binascii binascii a2b_qp12538128
Ref: 3ca212538128
Ref: library/binascii binascii b2a_qp12538425
Ref: 3ca312538425
Ref: library/binascii binascii crc_hqx12539193
Ref: 93e12539193
Ref: library/binascii binascii crc3212539498
Ref: 19f912539498
Ref: library/binascii binascii b2a_hex12540178
Ref: 286212540178
Ref: library/binascii binascii hexlify12540242
Ref: 3ca412540242
Ref: library/binascii binascii a2b_hex12541444
Ref: 286312541444
Ref: library/binascii binascii unhexlify12541484
Ref: 1e0e12541484
Ref: library/binascii binascii Error12542013
Ref: 122812542013
Ref: library/binascii binascii Incomplete12542117
Ref: 3ca512542117
Ref: binascii — Convert between binary and ASCII-Footnote-112542586
Ref: binascii — Convert between binary and ASCII-Footnote-212542645
Ref: binascii — Convert between binary and ASCII-Footnote-312542704
Node: quopri — Encode and decode MIME quoted-printable data12542763
Ref: library/quopri doc12542931
Ref: 3ca612542931
Ref: library/quopri module-quopri12542931
Ref: bc12542931
Ref: library/quopri quopri-encode-and-decode-mime-quoted-printable-data12542931
Ref: 3ca712542931
Ref: library/quopri translation-repo12542931
Ref: 3ca812542931
Ref: library/quopri quopri decode12543664
Ref: 286512543664
Ref: library/quopri quopri encode12544200
Ref: 286412544200
Ref: library/quopri quopri decodestring12544857
Ref: 3ca912544857
Ref: library/quopri quopri encodestring12545054
Ref: 3caa12545054
Ref: quopri — Encode and decode MIME quoted-printable data-Footnote-112545508
Ref: quopri — Encode and decode MIME quoted-printable data-Footnote-212545574
Ref: quopri — Encode and decode MIME quoted-printable data-Footnote-312545633
Ref: quopri — Encode and decode MIME quoted-printable data-Footnote-412545692
Ref: quopri — Encode and decode MIME quoted-printable data-Footnote-512545751
Node: Structured Markup Processing Tools12545810
Ref: library/markup doc12545978
Ref: 3cab12545978
Ref: library/markup markup12545978
Ref: 3cac12545978
Ref: library/markup structured-markup-processing-tools12545978
Ref: 3cad12545978
Ref: library/markup translation-repo12545978
Ref: 3cae12545978
Node: html — HyperText Markup Language support12547521
Ref: library/html doc12547687
Ref: 3caf12547687
Ref: library/html html-hypertext-markup-language-support12547687
Ref: 3cb012547687
Ref: library/html module-html12547687
Ref: 6f12547687
Ref: library/html html escape12547953
Ref: 121012547953
Ref: library/html html unescape12548533
Ref: b5212548533
Ref: html — HyperText Markup Language support-Footnote-112549237
Node: html parser — Simple HTML and XHTML parser12549310
Ref: library/html parser doc12549539
Ref: 3cb112549539
Ref: library/html parser html-parser-simple-html-and-xhtml-parser12549539
Ref: 3cb212549539
Ref: library/html parser module-html parser12549539
Ref: 7112549539
Ref: library/html parser translation-repo12549539
Ref: 3cb312549539
Ref: library/html parser html parser HTMLParser12549915
Ref: a7912549915
Ref: html parser — Simple HTML and XHTML parser-Footnote-112551332
Node: Example HTML Parser Application12551403
Ref: library/html parser example-html-parser-application12551542
Ref: 3cb412551542
Node: HTMLParser Methods12552748
Ref: library/html parser htmlparser-methods12552908
Ref: 3cb512552908
Ref: library/html parser html parser HTMLParser feed12553035
Ref: 3cb612553035
Ref: library/html parser html parser HTMLParser close12553302
Ref: 182912553302
Ref: library/html parser html parser HTMLParser reset12553663
Ref: 3cb712553663
Ref: library/html parser html parser HTMLParser getpos12553806
Ref: 3cb812553806
Ref: library/html parser html parser HTMLParser get_starttag_text12553885
Ref: 3cb912553885
Ref: library/html parser html parser HTMLParser handle_starttag12554454
Ref: 3cbb12554454
Ref: library/html parser html parser HTMLParser handle_endtag12555258
Ref: 3cbc12555258
Ref: library/html parser html parser HTMLParser handle_startendtag12555465
Ref: 3cba12555465
Ref: library/html parser html parser HTMLParser handle_data12555878
Ref: 3cbd12555878
Ref: library/html parser html parser HTMLParser handle_entityref12556062
Ref: 3cbe12556062
Ref: library/html parser html parser HTMLParser handle_charref12556360
Ref: 3cbf12556360
Ref: library/html parser html parser HTMLParser handle_comment12556800
Ref: 3cc012556800
Ref: library/html parser html parser HTMLParser handle_decl12557326
Ref: 3cc112557326
Ref: library/html parser html parser HTMLParser handle_pi12557610
Ref: 3cc212557610
Ref: library/html parser html parser HTMLParser unknown_decl12558300
Ref: 3cc312558300
Node: Examples<25>12558662
Ref: library/html parser examples12558782
Ref: 3cc412558782
Ref: library/html parser htmlparser-examples12558782
Ref: 3cc512558782
Node: html entities — Definitions of HTML general entities12562341
Ref: library/html entities doc12562550
Ref: 3cc612562550
Ref: library/html entities html-entities-definitions-of-html-general-entities12562550
Ref: 3cc712562550
Ref: library/html entities module-html entities12562550
Ref: 7012562550
Ref: library/html entities translation-repo12562550
Ref: 3cc812562550
Ref: library/html entities html entities html512562932
Ref: 12da12562932
Ref: library/html entities html entities entitydefs12563419
Ref: 3ccb12563419
Ref: library/html entities html entities name2codepoint12563558
Ref: 3cc912563558
Ref: library/html entities html entities codepoint2name12563679
Ref: 3cca12563679
Ref: html entities — Definitions of HTML general entities-Footnote-112563827
Ref: html entities — Definitions of HTML general entities-Footnote-212563900
Node: XML Processing Modules12564006
Ref: library/xml doc12564220
Ref: 3ccc12564220
Ref: library/xml module-xml12564220
Ref: 12612564220
Ref: library/xml translation-repo12564220
Ref: 3ccd12564220
Ref: library/xml xml12564220
Ref: 3cce12564220
Ref: library/xml xml-processing-modules12564220
Ref: 3ccf12564220
Ref: library/xml xml-security12565426
Ref: 3cd012565426
Ref: XML Processing Modules-Footnote-112565489
Node: XML security12565550
Ref: library/xml id112565621
Ref: 3cd112565621
Ref: library/xml xml-vulnerabilities12565621
Ref: 3cd212565621
Ref: XML security-Footnote-112568080
Ref: XML security-Footnote-212568125
Ref: XML security-Footnote-312568178
Ref: XML security-Footnote-412568231
Ref: XML security-Footnote-512568278
Node: xml etree ElementTree — The ElementTree XML API12568334
Ref: library/xml etree elementtree doc12568535
Ref: 3cd312568535
Ref: library/xml etree elementtree module-xml etree ElementTree12568535
Ref: 12b12568535
Ref: library/xml etree elementtree translation-repo12568535
Ref: 3cd412568535
Ref: library/xml etree elementtree xml-etree-elementtree-the-elementtree-xml-api12568535
Ref: 3cd512568535
Ref: xml etree ElementTree — The ElementTree XML API-Footnote-112569337
Node: Tutorial<3>12569419
Ref: library/xml etree elementtree tutorial12569538
Ref: 3cd612569538
Node: XML tree and elements12569964
Ref: library/xml etree elementtree xml-tree-and-elements12570053
Ref: 3cd712570053
Node: Parsing XML12570631
Ref: library/xml etree elementtree elementtree-parsing-xml12570762
Ref: 3cd812570762
Ref: library/xml etree elementtree parsing-xml12570762
Ref: 3cd912570762
Node: Pull API for non-blocking parsing12573239
Ref: library/xml etree elementtree elementtree-pull-parsing12573377
Ref: 11f612573377
Ref: library/xml etree elementtree pull-api-for-non-blocking-parsing12573377
Ref: 3cdb12573377
Node: Finding interesting elements12575492
Ref: library/xml etree elementtree finding-interesting-elements12575640
Ref: 3cde12575640
Node: Modifying an XML File12576882
Ref: library/xml etree elementtree modifying-an-xml-file12577019
Ref: 3ce112577019
Node: Building XML documents12579963
Ref: library/xml etree elementtree building-xml-documents12580099
Ref: 3ce412580099
Node: Parsing XML with Namespaces12580468
Ref: library/xml etree elementtree parsing-xml-with-namespaces12580574
Ref: 3ce612580574
Ref: Parsing XML with Namespaces-Footnote-112582887
Ref: Parsing XML with Namespaces-Footnote-212582939
Node: XPath support12582991
Ref: library/xml etree elementtree elementtree-xpath12583131
Ref: da812583131
Ref: library/xml etree elementtree xpath-support12583131
Ref: 3ce712583131
Ref: XPath support-Footnote-112583492
Node: Example<8>12583528
Ref: library/xml etree elementtree example12583619
Ref: 3ce812583619
Node: Supported XPath syntax12584638
Ref: library/xml etree elementtree supported-xpath-syntax12584729
Ref: 3ce912584729
Node: Reference<5>12589717
Ref: library/xml etree elementtree reference12589862
Ref: 3cea12589862
Node: Functions<8>12589940
Ref: library/xml etree elementtree elementtree-functions12590001
Ref: 3ceb12590001
Ref: library/xml etree elementtree functions12590001
Ref: 3cec12590001
Ref: library/xml etree elementtree xml etree ElementTree canonicalize12590042
Ref: c4a12590042
Ref: library/xml etree elementtree xml etree ElementTree Comment12592422
Ref: 3ced12592422
Ref: library/xml etree elementtree xml etree ElementTree dump12593107
Ref: 3cee12593107
Ref: library/xml etree elementtree xml etree ElementTree fromstring12593586
Ref: 3cda12593586
Ref: library/xml etree elementtree xml etree ElementTree fromstringlist12593945
Ref: 13d912593945
Ref: library/xml etree elementtree xml etree ElementTree indent12594365
Ref: 3cf012594365
Ref: library/xml etree elementtree xml etree ElementTree iselement12594893
Ref: 3cf112594893
Ref: library/xml etree elementtree xml etree ElementTree iterparse12595107
Ref: 57a12595107
Ref: library/xml etree elementtree xml etree ElementTree parse12597278
Ref: 3cf212597278
Ref: library/xml etree elementtree xml etree ElementTree ProcessingInstruction12597622
Ref: 3cf312597622
Ref: library/xml etree elementtree xml etree ElementTree register_namespace12598350
Ref: 13da12598350
Ref: library/xml etree elementtree xml etree ElementTree SubElement12598781
Ref: 3ce512598781
Ref: library/xml etree elementtree xml etree ElementTree tostring12599351
Ref: 11f712599351
Ref: library/xml etree elementtree xml etree ElementTree tostringlist12600471
Ref: 11f812600471
Ref: library/xml etree elementtree xml etree ElementTree XML12601763
Ref: 3cef12601763
Ref: library/xml etree elementtree xml etree ElementTree XMLID12602155
Ref: 3cf412602155
Ref: Functions<8>-Footnote-112602630
Ref: Functions<8>-Footnote-212602671
Ref: Functions<8>-Footnote-312602976
Node: XInclude support12603281
Ref: library/xml etree elementtree elementtree-xinclude12603425
Ref: 3cf512603425
Ref: library/xml etree elementtree xinclude-support12603425
Ref: 3cf612603425
Ref: XInclude support-Footnote-112603790
Node: Example<9>12603830
Ref: library/xml etree elementtree id312603893
Ref: 3cf712603893
Node: Reference<6>12605703
Ref: library/xml etree elementtree id412605826
Ref: 3cf812605826
Node: Functions<9>12606068
Ref: library/xml etree elementtree elementinclude-functions12606153
Ref: 3cf912606153
Ref: library/xml etree elementtree id512606153
Ref: 3cfa12606153
Ref: library/xml etree elementtree module-xml etree ElementInclude12606194
Ref: 12a12606194
Ref: library/xml etree elementtree xml etree ElementInclude default_loader12606194
Ref: 3cfb12606194
Ref: library/xml etree elementtree xml etree ElementInclude include12606785
Ref: 3cfc12606785
Node: Element Objects12607674
Ref: library/xml etree elementtree element-objects12607787
Ref: 3cfd12607787
Ref: library/xml etree elementtree elementtree-element-objects12607787
Ref: 3cfe12607787
Ref: library/xml etree elementtree xml etree ElementTree Element12607840
Ref: 36312607840
Ref: library/xml etree elementtree xml etree ElementTree Element tag12608323
Ref: 155512608323
Ref: library/xml etree elementtree xml etree ElementTree Element text12608468
Ref: 3cdf12608468
Ref: library/xml etree elementtree xml etree ElementTree Element tail12608493
Ref: 3cff12608493
Ref: library/xml etree elementtree xml etree ElementTree Element attrib12609609
Ref: 3d0012609609
Ref: library/xml etree elementtree xml etree ElementTree Element clear12610153
Ref: 3d0112610153
Ref: library/xml etree elementtree xml etree ElementTree Element get12610346
Ref: 3ce012610346
Ref: library/xml etree elementtree xml etree ElementTree Element items12610534
Ref: 3d0212610534
Ref: library/xml etree elementtree xml etree ElementTree Element keys12610703
Ref: 3d0312610703
Ref: library/xml etree elementtree xml etree ElementTree Element set12610845
Ref: 3ce212610845
Ref: library/xml etree elementtree xml etree ElementTree Element append12611018
Ref: 3ce312611018
Ref: library/xml etree elementtree xml etree ElementTree Element extend12611254
Ref: 13db12611254
Ref: library/xml etree elementtree xml etree ElementTree Element find12611485
Ref: 186212611485
Ref: library/xml etree elementtree xml etree ElementTree Element findall12611907
Ref: 186412611907
Ref: library/xml etree elementtree xml etree ElementTree Element findtext12612326
Ref: 186312612326
Ref: library/xml etree elementtree xml etree ElementTree Element insert12612930
Ref: 3d0412612930
Ref: library/xml etree elementtree xml etree ElementTree Element iter12613141
Ref: 155612613141
Ref: library/xml etree elementtree xml etree ElementTree Element iterfind12613633
Ref: 13dc12613633
Ref: library/xml etree elementtree xml etree ElementTree Element itertext12613967
Ref: 13dd12613967
Ref: library/xml etree elementtree xml etree ElementTree Element makeelement12614192
Ref: 3d0512614192
Ref: library/xml etree elementtree xml etree ElementTree Element remove12614415
Ref: 185e12614415
Ref: Element Objects-Footnote-112617171
Node: ElementTree Objects12617214
Ref: library/xml etree elementtree elementtree-elementtree-objects12617328
Ref: 3d0612617328
Ref: library/xml etree elementtree elementtree-objects12617328
Ref: 3d0712617328
Ref: library/xml etree elementtree xml etree ElementTree ElementTree12617389
Ref: b4912617389
Ref: library/xml etree elementtree xml etree ElementTree ElementTree _setroot12617742
Ref: 3d0812617742
Ref: library/xml etree elementtree xml etree ElementTree ElementTree find12617991
Ref: 3d0912617991
Ref: library/xml etree elementtree xml etree ElementTree ElementTree findall12618130
Ref: 3d0a12618130
Ref: library/xml etree elementtree xml etree ElementTree ElementTree findtext12618275
Ref: 3d0b12618275
Ref: library/xml etree elementtree xml etree ElementTree ElementTree getroot12618436
Ref: 3d0c12618436
Ref: library/xml etree elementtree xml etree ElementTree ElementTree iter12618516
Ref: 3d0d12618516
Ref: library/xml etree elementtree xml etree ElementTree ElementTree iterfind12618786
Ref: 3d0e12618786
Ref: library/xml etree elementtree xml etree ElementTree ElementTree parse12618966
Ref: 3d0f12618966
Ref: library/xml etree elementtree xml etree ElementTree ElementTree write12619312
Ref: c8e12619312
Ref: ElementTree Objects-Footnote-112622118
Node: QName Objects12622423
Ref: library/xml etree elementtree elementtree-qname-objects12622541
Ref: 3d1012622541
Ref: library/xml etree elementtree qname-objects12622541
Ref: 3d1112622541
Ref: library/xml etree elementtree xml etree ElementTree QName12622590
Ref: 3d1212622590
Node: TreeBuilder Objects12623104
Ref: library/xml etree elementtree elementtree-treebuilder-objects12623220
Ref: 3d1312623220
Ref: library/xml etree elementtree treebuilder-objects12623220
Ref: 3d1412623220
Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder12623281
Ref: c4c12623281
Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder close12624400
Ref: 3d1512624400
Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder data12624562
Ref: 3d1612624562
Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder end12624726
Ref: 13de12624726
Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder start12624859
Ref: 1d5412624859
Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder comment12625061
Ref: 3d1712625061
Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder pi12625259
Ref: 3d1812625259
Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder doctype12625594
Ref: c9012625594
Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder start_ns12625920
Ref: 3d1912625920
Ref: library/xml etree elementtree xml etree ElementTree TreeBuilder end_ns12626316
Ref: 3d1a12626316
Ref: library/xml etree elementtree xml etree ElementTree C14NWriterTarget12626565
Ref: 3d1b12626565
Ref: TreeBuilder Objects-Footnote-112627115
Node: XMLParser Objects12627156
Ref: library/xml etree elementtree elementtree-xmlparser-objects12627280
Ref: 3d1c12627280
Ref: library/xml etree elementtree xmlparser-objects12627280
Ref: 3d1d12627280
Ref: library/xml etree elementtree xml etree ElementTree XMLParser12627337
Ref: c4b12627337
Ref: library/xml etree elementtree xml etree ElementTree XMLParser close12628059
Ref: 3d1f12628059
Ref: library/xml etree elementtree xml etree ElementTree XMLParser feed12628315
Ref: 3d1e12628315
Ref: library/xml etree elementtree xml etree ElementTree XMLParser flush12628407
Ref: 57612628407
Ref: XMLParser Objects-Footnote-112631045
Node: XMLPullParser Objects12631350
Ref: library/xml etree elementtree elementtree-xmlpullparser-objects12631469
Ref: 3d2012631469
Ref: library/xml etree elementtree xmlpullparser-objects12631469
Ref: 3d2112631469
Ref: library/xml etree elementtree xml etree ElementTree XMLPullParser12631534
Ref: 11f512631534
Ref: library/xml etree elementtree xml etree ElementTree XMLPullParser feed12632226
Ref: 3cdc12632226
Ref: library/xml etree elementtree xml etree ElementTree XMLPullParser flush12632308
Ref: 57712632308
Ref: library/xml etree elementtree xml etree ElementTree XMLPullParser close12633167
Ref: 3d2212633167
Ref: library/xml etree elementtree xml etree ElementTree XMLPullParser read_events12633478
Ref: 3cdd12633478
Node: Exceptions<21>12635219
Ref: library/xml etree elementtree exceptions12635312
Ref: 3d2312635312
Ref: library/xml etree elementtree xml etree ElementTree ParseError12635355
Ref: 147f12635355
Ref: library/xml etree elementtree xml etree ElementTree ParseError code12635684
Ref: 3d2412635684
Ref: library/xml etree elementtree xml etree ElementTree ParseError position12635889
Ref: 3d2512635889
Node: xml dom — The Document Object Model API12636014
Ref: library/xml dom doc12636239
Ref: 3d2612636239
Ref: library/xml dom module-xml dom12636239
Ref: 12712636239
Ref: library/xml dom translation-repo12636239
Ref: 3d2712636239
Ref: library/xml dom xml-dom-the-document-object-model-api12636239
Ref: 3d2812636239
Ref: xml dom — The Document Object Model API-Footnote-112639713
Ref: xml dom — The Document Object Model API-Footnote-212639790
Ref: xml dom — The Document Object Model API-Footnote-312639856
Ref: xml dom — The Document Object Model API-Footnote-412639903
Node: Module Contents<4>12639949
Ref: library/xml dom module-contents12640072
Ref: 3d2b12640072
Ref: library/xml dom xml dom registerDOMImplementation12640182
Ref: 3d2c12640182
Ref: library/xml dom xml dom getDOMImplementation12640630
Ref: 3d2912640630
Ref: library/xml dom xml dom EMPTY_NAMESPACE12641539
Ref: 3d2d12641539
Ref: library/xml dom xml dom XML_NAMESPACE12641812
Ref: 3d2e12641812
Ref: library/xml dom xml dom XMLNS_NAMESPACE12641969
Ref: 3d2f12641969
Ref: library/xml dom xml dom XHTML_NAMESPACE12642155
Ref: 3d3012642155
Ref: Module Contents<4>-Footnote-112642890
Ref: Module Contents<4>-Footnote-212642935
Ref: Module Contents<4>-Footnote-312642992
Node: Objects in the DOM12643030
Ref: library/xml dom dom-objects12643173
Ref: 3d3112643173
Ref: library/xml dom objects-in-the-dom12643173
Ref: 3d3212643173
Node: DOMImplementation Objects12647708
Ref: library/xml dom dom-implementation-objects12647809
Ref: 3d3312647809
Ref: library/xml dom domimplementation-objects12647809
Ref: 3d3c12647809
Ref: library/xml dom xml dom DOMImplementation hasFeature12648165
Ref: 3d3d12648165
Ref: library/xml dom xml dom DOMImplementation createDocument12648344
Ref: 3d3e12648344
Ref: library/xml dom xml dom DOMImplementation createDocumentType12648864
Ref: 3d3f12648864
Node: Node Objects12649172
Ref: library/xml dom dom-node-objects12649298
Ref: 3d3412649298
Ref: library/xml dom node-objects12649298
Ref: 3d4012649298
Ref: library/xml dom xml dom Node nodeType12649415
Ref: 3d4112649415
Ref: library/xml dom xml dom Node parentNode12649838
Ref: 3d4212649838
Ref: library/xml dom xml dom Node attributes12650247
Ref: 3d4312650247
Ref: library/xml dom xml dom Node previousSibling12650460
Ref: 3d4412650460
Ref: library/xml dom xml dom Node nextSibling12650946
Ref: 3d4512650946
Ref: library/xml dom xml dom Node childNodes12651212
Ref: 3d4612651212
Ref: library/xml dom xml dom Node firstChild12651331
Ref: 3d4712651331
Ref: library/xml dom xml dom Node lastChild12651468
Ref: 3d4812651468
Ref: library/xml dom xml dom Node localName12651603
Ref: 3d4912651603
Ref: library/xml dom xml dom Node prefix12651767
Ref: 3d4a12651767
Ref: library/xml dom xml dom Node namespaceURI12651935
Ref: 3d4b12651935
Ref: library/xml dom xml dom Node nodeName12652098
Ref: 3d4c12652098
Ref: library/xml dom xml dom Node nodeValue12652535
Ref: 3d4d12652535
Ref: library/xml dom xml dom Node hasAttributes12652769
Ref: 3d4e12652769
Ref: library/xml dom xml dom Node hasChildNodes12652860
Ref: 3d4f12652860
Ref: library/xml dom xml dom Node isSameNode12652952
Ref: 3d5012652952
Ref: library/xml dom xml dom Node appendChild12653579
Ref: 3d5112653579
Ref: library/xml dom xml dom Node insertBefore12653787
Ref: 3d5212653787
Ref: library/xml dom xml dom Node removeChild12654128
Ref: 3d5312654128
Ref: library/xml dom xml dom Node replaceChild12654416
Ref: 3d5412654416
Ref: library/xml dom xml dom Node normalize12654630
Ref: 3d5512654630
Ref: library/xml dom xml dom Node cloneNode12654847
Ref: 3d5612654847
Node: NodeList Objects12654991
Ref: library/xml dom dom-nodelist-objects12655112
Ref: 239112655112
Ref: library/xml dom nodelist-objects12655112
Ref: 3d5712655112
Ref: library/xml dom xml dom NodeList item12655593
Ref: 3d5812655593
Ref: library/xml dom xml dom NodeList length12655823
Ref: 3d5912655823
Node: DocumentType Objects12656493
Ref: library/xml dom documenttype-objects12656618
Ref: 3d5a12656618
Ref: library/xml dom dom-documenttype-objects12656618
Ref: 3d3512656618
Ref: library/xml dom xml dom DocumentType publicId12657251
Ref: 3d5b12657251
Ref: library/xml dom xml dom DocumentType systemId12657417
Ref: 3d5c12657417
Ref: library/xml dom xml dom DocumentType internalSubset12657593
Ref: 3d5d12657593
Ref: library/xml dom xml dom DocumentType name12657846
Ref: 3d5e12657846
Ref: library/xml dom xml dom DocumentType entities12657975
Ref: 3d5f12657975
Ref: library/xml dom xml dom DocumentType notations12658358
Ref: 3d6012658358
Node: Document Objects12658737
Ref: library/xml dom document-objects12658864
Ref: 3d6112658864
Ref: library/xml dom dom-document-objects12658864
Ref: 3d3612658864
Ref: library/xml dom xml dom Document documentElement12659111
Ref: 176712659111
Ref: library/xml dom xml dom Document createElement12659205
Ref: 3d6212659205
Ref: library/xml dom xml dom Document createElementNS12659494
Ref: 3d6312659494
Ref: library/xml dom xml dom Document createTextNode12659845
Ref: 3d6412659845
Ref: library/xml dom xml dom Document createComment12660064
Ref: 3d6512660064
Ref: library/xml dom xml dom Document createProcessingInstruction12660285
Ref: 3d6612660285
Ref: library/xml dom xml dom Document createAttribute12660557
Ref: 3d6712660557
Ref: library/xml dom xml dom Document createAttributeNS12660864
Ref: 3d6812660864
Ref: library/xml dom xml dom Document getElementsByTagName12661252
Ref: 3d6912661252
Ref: library/xml dom xml dom Document getElementsByTagNameNS12661428
Ref: 3d6a12661428
Node: Element Objects<2>12661699
Ref: library/xml dom dom-element-objects12661818
Ref: 3d3712661818
Ref: library/xml dom element-objects12661818
Ref: 3d6b12661818
Ref: library/xml dom xml dom Element tagName12661959
Ref: 3d6c12661959
Ref: library/xml dom xml dom Element getElementsByTagName12662106
Ref: 3d6d12662106
Ref: library/xml dom xml dom Element getElementsByTagNameNS12662219
Ref: 3d6e12662219
Ref: library/xml dom xml dom Element hasAttribute12662350
Ref: 3d6f12662350
Ref: library/xml dom xml dom Element hasAttributeNS12662464
Ref: 3d7012662464
Ref: library/xml dom xml dom Element getAttribute12662628
Ref: 3d7112662628
Ref: library/xml dom xml dom Element getAttributeNode12662841
Ref: 3d7212662841
Ref: library/xml dom xml dom Element getAttributeNS12662962
Ref: 3d7312662962
Ref: library/xml dom xml dom Element getAttributeNodeNS12663220
Ref: 3d7412663220
Ref: library/xml dom xml dom Element removeAttribute12663374
Ref: 3d7512663374
Ref: library/xml dom xml dom Element removeAttributeNode12663532
Ref: 3d7712663532
Ref: library/xml dom xml dom Element removeAttributeNS12663724
Ref: 3d7812663724
Ref: library/xml dom xml dom Element setAttribute12663933
Ref: 3d7912663933
Ref: library/xml dom xml dom Element setAttributeNode12664025
Ref: 3d7a12664025
Ref: library/xml dom xml dom Element setAttributeNodeNS12664369
Ref: 3d7c12664369
Ref: library/xml dom xml dom Element setAttributeNS12664742
Ref: 3d7d12664742
Node: Attr Objects12664978
Ref: library/xml dom attr-objects12665101
Ref: 3d7e12665101
Ref: library/xml dom dom-attr-objects12665101
Ref: 3d3812665101
Ref: library/xml dom xml dom Attr name12665216
Ref: 3d7f12665216
Ref: library/xml dom xml dom Attr localName12665328
Ref: 3d8012665328
Ref: library/xml dom xml dom Attr prefix12665482
Ref: 3d8112665482
Ref: library/xml dom xml dom Attr value12665602
Ref: 3d8212665602
Node: NamedNodeMap Objects12665727
Ref: library/xml dom dom-attributelist-objects12665847
Ref: 3d8312665847
Ref: library/xml dom namednodemap-objects12665847
Ref: 3d8412665847
Ref: library/xml dom xml dom NamedNodeMap length12665966
Ref: 3d8512665966
Ref: library/xml dom xml dom NamedNodeMap item12666042
Ref: 3d8612666042
Node: Comment Objects12666523
Ref: library/xml dom comment-objects12666660
Ref: 3d8712666660
Ref: library/xml dom dom-comment-objects12666660
Ref: 3d3912666660
Ref: library/xml dom xml dom Comment data12666832
Ref: 3d8812666832
Node: Text and CDATASection Objects12667050
Ref: library/xml dom dom-text-objects12667196
Ref: 3d3a12667196
Ref: library/xml dom text-and-cdatasection-objects12667196
Ref: 3d8912667196
Ref: library/xml dom xml dom Text data12667692
Ref: 3d8a12667692
Node: ProcessingInstruction Objects12668185
Ref: library/xml dom dom-pi-objects12668330
Ref: 3d3b12668330
Ref: library/xml dom processinginstruction-objects12668330
Ref: 3d8b12668330
Ref: library/xml dom xml dom ProcessingInstruction target12668542
Ref: 3d8c12668542
Ref: library/xml dom xml dom ProcessingInstruction data12668710
Ref: 3d8d12668710
Node: Exceptions<22>12668848
Ref: library/xml dom dom-exceptions12668955
Ref: 3d8e12668955
Ref: library/xml dom exceptions12668955
Ref: 3d8f12668955
Ref: library/xml dom xml dom DOMException12669634
Ref: 3d9012669634
Ref: library/xml dom xml dom DomstringSizeErr12669796
Ref: 3d9112669796
Ref: library/xml dom xml dom HierarchyRequestErr12670051
Ref: 3d9212670051
Ref: library/xml dom xml dom IndexSizeErr12670190
Ref: 3d9312670190
Ref: library/xml dom xml dom InuseAttributeErr12670332
Ref: 3d7b12670332
Ref: library/xml dom xml dom InvalidAccessErr12670496
Ref: 3d9412670496
Ref: library/xml dom xml dom InvalidCharacterErr12670629
Ref: 3d9512670629
Ref: library/xml dom xml dom InvalidModificationErr12670989
Ref: 3d9612670989
Ref: library/xml dom xml dom InvalidStateErr12671103
Ref: 3d9712671103
Ref: library/xml dom xml dom NamespaceErr12671246
Ref: 3d9812671246
Ref: library/xml dom xml dom NotFoundErr12671455
Ref: 3d7612671455
Ref: library/xml dom xml dom NotSupportedErr12671686
Ref: 3d9912671686
Ref: library/xml dom xml dom NoDataAllowedErr12671828
Ref: 3d9a12671828
Ref: library/xml dom xml dom NoModificationAllowedErr12671956
Ref: 3d9b12671956
Ref: library/xml dom xml dom SyntaxErr12672122
Ref: 3d9c12672122
Ref: library/xml dom xml dom WrongDocumentErr12672217
Ref: 3d9d12672217
Ref: Exceptions<22>-Footnote-112675258
Node: Conformance12675303
Ref: library/xml dom conformance12675419
Ref: 3d9e12675419
Ref: library/xml dom dom-conformance12675419
Ref: 3d2a12675419
Node: Type Mapping12675676
Ref: library/xml dom dom-type-mapping12675761
Ref: 3d9f12675761
Ref: library/xml dom type-mapping12675761
Ref: 3da012675761
Node: Accessor Methods12676586
Ref: library/xml dom accessor-methods12676671
Ref: 3da112676671
Ref: library/xml dom dom-accessor-methods12676671
Ref: 3da212676671
Node: xml dom minidom — Minimal DOM implementation12678537
Ref: library/xml dom minidom doc12678771
Ref: 3da312678771
Ref: library/xml dom minidom module-xml dom minidom12678771
Ref: 12812678771
Ref: library/xml dom minidom translation-repo12678771
Ref: 3da412678771
Ref: library/xml dom minidom xml-dom-minidom-minimal-dom-implementation12678771
Ref: 3da512678771
Ref: library/xml dom minidom xml dom minidom parse12680003
Ref: 3da612680003
Ref: library/xml dom minidom xml dom minidom parseString12680572
Ref: 3da712680572
Ref: xml dom minidom — Minimal DOM implementation-Footnote-112683147
Ref: xml dom minidom — Minimal DOM implementation-Footnote-212683223
Node: DOM Objects12683270
Ref: library/xml dom minidom dom-objects12683384
Ref: 3da812683384
Ref: library/xml dom minidom minidom-objects12683384
Ref: 3da912683384
Ref: library/xml dom minidom xml dom minidom Node unlink12683619
Ref: 3daa12683619
Ref: library/xml dom minidom xml dom minidom Node writexml12684395
Ref: c8b12684395
Ref: library/xml dom minidom xml dom minidom Node toxml12685644
Ref: c8c12685644
Ref: library/xml dom minidom xml dom minidom Node toprettyxml12686461
Ref: c8d12686461
Ref: DOM Objects-Footnote-112687209
Node: DOM Example12687608
Ref: library/xml dom minidom dom-example12687759
Ref: 3dab12687759
Ref: library/xml dom minidom id212687759
Ref: 3dac12687759
Node: minidom and the DOM standard12689791
Ref: library/xml dom minidom minidom-and-dom12689922
Ref: 3dad12689922
Ref: library/xml dom minidom minidom-and-the-dom-standard12689922
Ref: 3dae12689922
Node: xml dom pulldom — Support for building partial DOM trees12692561
Ref: library/xml dom pulldom doc12692790
Ref: 3daf12692790
Ref: library/xml dom pulldom module-xml dom pulldom12692790
Ref: 12912692790
Ref: library/xml dom pulldom translation-repo12692790
Ref: 3db012692790
Ref: library/xml dom pulldom xml-dom-pulldom-support-for-building-partial-dom-trees12692790
Ref: 3db112692790
Ref: library/xml dom pulldom xml dom pulldom PullDOM12695430
Ref: 3db312695430
Ref: library/xml dom pulldom xml dom pulldom SAX2DOM12695552
Ref: 3db512695552
Ref: library/xml dom pulldom xml dom pulldom parse12695674
Ref: 3db612695674
Ref: library/xml dom pulldom xml dom pulldom parseString12696266
Ref: 3db812696266
Ref: library/xml dom pulldom xml dom pulldom default_bufsize12696418
Ref: 3db912696418
Ref: xml dom pulldom — Support for building partial DOM trees-Footnote-112696731
Node: DOMEventStream Objects12696807
Ref: library/xml dom pulldom domeventstream-objects12696924
Ref: 3dba12696924
Ref: library/xml dom pulldom id112696924
Ref: 3dbb12696924
Ref: library/xml dom pulldom xml dom pulldom DOMEventStream12696989
Ref: 93f12696989
Ref: library/xml dom pulldom xml dom pulldom DOMEventStream getEvent12697163
Ref: 3dbc12697163
Ref: library/xml dom pulldom xml dom pulldom DOMEventStream expandNode12697655
Ref: 3db212697655
Ref: library/xml dom pulldom xml dom pulldom DOMEventStream reset12698369
Ref: 3dbd12698369
Node: xml sax — Support for SAX2 parsers12698396
Ref: library/xml sax doc12698628
Ref: 3dbe12698628
Ref: library/xml sax module-xml sax12698628
Ref: 12f12698628
Ref: library/xml sax translation-repo12698628
Ref: 3dbf12698628
Ref: library/xml sax xml-sax-support-for-sax2-parsers12698628
Ref: 3dc012698628
Ref: library/xml sax xml sax make_parser12699626
Ref: 1e0412699626
Ref: library/xml sax xml sax parse12700129
Ref: 1dce12700129
Ref: library/xml sax xml sax parseString12700724
Ref: 109e12700724
Ref: library/xml sax xml sax SAXException12702659
Ref: 3dc512702659
Ref: library/xml sax xml sax SAXParseException12703531
Ref: 3dc312703531
Ref: library/xml sax xml sax SAXNotRecognizedException12703942
Ref: 3dc612703942
Ref: library/xml sax xml sax SAXNotSupportedException12704244
Ref: 3dc712704244
Ref: xml sax — Support for SAX2 parsers-Footnote-112705262
Ref: xml sax — Support for SAX2 parsers-Footnote-212705339
Node: SAXException Objects12705374
Ref: library/xml sax sax-exception-objects12705467
Ref: 3dc812705467
Ref: library/xml sax saxexception-objects12705467
Ref: 3dc912705467
Ref: library/xml sax xml sax SAXException getMessage12705607
Ref: 3dca12705607
Ref: library/xml sax xml sax SAXException getException12705717
Ref: 3dcb12705717
Node: xml sax handler — Base classes for SAX handlers12705821
Ref: library/xml sax handler doc12706029
Ref: 3dcc12706029
Ref: library/xml sax handler module-xml sax handler12706029
Ref: 13012706029
Ref: library/xml sax handler translation-repo12706029
Ref: 3dcd12706029
Ref: library/xml sax handler xml-sax-handler-base-classes-for-sax-handlers12706029
Ref: 3dce12706029
Ref: library/xml sax handler xml sax handler ContentHandler12706732
Ref: 3db412706732
Ref: library/xml sax handler xml sax handler DTDHandler12706973
Ref: 3dcf12706973
Ref: library/xml sax handler xml sax handler EntityResolver12707159
Ref: 3dd012707159
Ref: library/xml sax handler xml sax handler ErrorHandler12707442
Ref: 3dc212707442
Ref: library/xml sax handler xml sax handler LexicalHandler12707717
Ref: a5e12707717
Ref: library/xml sax handler xml sax handler feature_namespaces12708009
Ref: 3dd112708009
Ref: library/xml sax handler xml sax handler feature_namespace_prefixes12708333
Ref: 3dd212708333
Ref: library/xml sax handler xml sax handler feature_string_interning12708762
Ref: 3dd312708762
Ref: library/xml sax handler xml sax handler feature_validation12709177
Ref: 3dd412709177
Ref: library/xml sax handler xml sax handler feature_external_ges12709516
Ref: 17b512709516
Ref: library/xml sax handler xml sax handler feature_external_pes12710069
Ref: 3dd512710069
Ref: library/xml sax handler xml sax handler all_features12710450
Ref: 3dd612710450
Ref: library/xml sax handler xml sax handler property_lexical_handler12710518
Ref: 3dd712710518
Ref: library/xml sax handler xml sax handler property_declaration_handler12710838
Ref: 3dd812710838
Ref: library/xml sax handler xml sax handler property_dom_node12711196
Ref: 3dd912711196
Ref: library/xml sax handler xml sax handler property_xml_string12711586
Ref: 3dda12711586
Ref: library/xml sax handler xml sax handler all_properties12711854
Ref: 3ddb12711854
Ref: xml sax handler — Base classes for SAX handlers-Footnote-112712111
Ref: xml sax handler — Base classes for SAX handlers-Footnote-212712187
Ref: xml sax handler — Base classes for SAX handlers-Footnote-312712252
Node: ContentHandler Objects12712303
Ref: library/xml sax handler content-handler-objects12712438
Ref: 3ddc12712438
Ref: library/xml sax handler contenthandler-objects12712438
Ref: 3ddd12712438
Ref: library/xml sax handler xml sax handler ContentHandler setDocumentLocator12712692
Ref: 3dde12712692
Ref: library/xml sax handler xml sax handler ContentHandler startDocument12713767
Ref: 3ddf12713767
Ref: library/xml sax handler xml sax handler ContentHandler endDocument12714045
Ref: 3de012714045
Ref: library/xml sax handler xml sax handler ContentHandler startPrefixMapping12714413
Ref: 3de112714413
Ref: library/xml sax handler xml sax handler ContentHandler endPrefixMapping12715615
Ref: 3de212715615
Ref: library/xml sax handler xml sax handler ContentHandler startElement12715958
Ref: 174a12715958
Ref: library/xml sax handler xml sax handler ContentHandler endElement12716557
Ref: 174b12716557
Ref: library/xml sax handler xml sax handler ContentHandler startElementNS12716785
Ref: 3de412716785
Ref: library/xml sax handler xml sax handler ContentHandler endElementNS12717729
Ref: 3de612717729
Ref: library/xml sax handler xml sax handler ContentHandler characters12718002
Ref: 174c12718002
Ref: library/xml sax handler xml sax handler ContentHandler ignorableWhitespace12719029
Ref: 3de712719029
Ref: library/xml sax handler xml sax handler ContentHandler processingInstruction12719696
Ref: 3de812719696
Ref: library/xml sax handler xml sax handler ContentHandler skippedEntity12720156
Ref: 3de912720156
Node: DTDHandler Objects12720656
Ref: library/xml sax handler dtd-handler-objects12720822
Ref: 3dea12720822
Ref: library/xml sax handler dtdhandler-objects12720822
Ref: 3deb12720822
Ref: library/xml sax handler xml sax handler DTDHandler notationDecl12720947
Ref: 3dec12720947
Ref: library/xml sax handler xml sax handler DTDHandler unparsedEntityDecl12721054
Ref: 3ded12721054
Node: EntityResolver Objects12721192
Ref: library/xml sax handler entity-resolver-objects12721356
Ref: 3dee12721356
Ref: library/xml sax handler entityresolver-objects12721356
Ref: 3def12721356
Ref: library/xml sax handler xml sax handler EntityResolver resolveEntity12721423
Ref: 3df012721423
Node: ErrorHandler Objects12721691
Ref: library/xml sax handler errorhandler-objects12721859
Ref: 3df112721859
Ref: library/xml sax handler sax-error-handler12721859
Ref: 3df212721859
Ref: library/xml sax handler xml sax handler ErrorHandler error12722514
Ref: 3df312722514
Ref: library/xml sax handler xml sax handler ErrorHandler fatalError12722883
Ref: 3df412722883
Ref: library/xml sax handler xml sax handler ErrorHandler warning12723069
Ref: 3df512723069
Node: LexicalHandler Objects12723414
Ref: library/xml sax handler lexical-handler-objects12723551
Ref: 3df612723551
Ref: library/xml sax handler lexicalhandler-objects12723551
Ref: 3df712723551
Ref: library/xml sax handler xml sax handler LexicalHandler comment12724156
Ref: 3df812724156
Ref: library/xml sax handler xml sax handler LexicalHandler startDTD12724310
Ref: 3df912724310
Ref: library/xml sax handler xml sax handler LexicalHandler endDTD12724468
Ref: 3dfa12724468
Ref: library/xml sax handler xml sax handler LexicalHandler startCDATA12724548
Ref: 3dfb12724548
Ref: library/xml sax handler xml sax handler LexicalHandler endCDATA12724742
Ref: 3dfc12724742
Node: xml sax saxutils — SAX Utilities12724831
Ref: library/xml sax utils doc12725050
Ref: 3dfd12725050
Ref: library/xml sax utils module-xml sax saxutils12725050
Ref: 13112725050
Ref: library/xml sax utils translation-repo12725050
Ref: 3dfe12725050
Ref: library/xml sax utils xml-sax-saxutils-sax-utilities12725050
Ref: 3dff12725050
Ref: library/xml sax utils xml sax saxutils escape12725437
Ref: 3e0012725437
Ref: library/xml sax utils xml sax saxutils unescape12726088
Ref: 3e0112726088
Ref: library/xml sax utils xml sax saxutils quoteattr12726556
Ref: 3e0212726556
Ref: library/xml sax utils xml sax saxutils XMLGenerator12727465
Ref: 3e0312727465
Ref: library/xml sax utils xml sax saxutils XMLFilterBase12728339
Ref: 3e0412728339
Ref: library/xml sax utils xml sax saxutils prepare_input_source12728762
Ref: 3e0512728762
Ref: xml sax saxutils — SAX Utilities-Footnote-112729260
Node: xml sax xmlreader — Interface for XML parsers12729337
Ref: library/xml sax reader doc12729557
Ref: 3e0712729557
Ref: library/xml sax reader module-xml sax xmlreader12729557
Ref: 13212729557
Ref: library/xml sax reader translation-repo12729557
Ref: 3e0812729557
Ref: library/xml sax reader xml-sax-xmlreader-interface-for-xml-parsers12729557
Ref: 3e0912729557
Ref: library/xml sax reader xml sax xmlreader XMLReader12730057
Ref: 3db712730057
Ref: library/xml sax reader xml sax xmlreader IncrementalParser12730154
Ref: 3e0a12730154
Ref: library/xml sax reader xml sax xmlreader Locator12731282
Ref: 3dc412731282
Ref: library/xml sax reader xml sax xmlreader InputSource12731616
Ref: 109d12731616
Ref: library/xml sax reader xml sax xmlreader AttributesImpl12732387
Ref: 3e0b12732387
Ref: library/xml sax reader xml sax xmlreader AttributesNSImpl12732987
Ref: 3e0c12732987
Ref: xml sax xmlreader — Interface for XML parsers-Footnote-112733745
Node: XMLReader Objects12733823
Ref: library/xml sax reader id112733958
Ref: 3e0d12733958
Ref: library/xml sax reader xmlreader-objects12733958
Ref: 3e0e12733958
Ref: library/xml sax reader xml sax xmlreader XMLReader parse12734085
Ref: 3e0612734085
Ref: library/xml sax reader xml sax xmlreader XMLReader getContentHandler12734686
Ref: 3e0f12734686
Ref: library/xml sax reader xml sax xmlreader XMLReader setContentHandler12734783
Ref: 3e1012734783
Ref: library/xml sax reader xml sax xmlreader XMLReader getDTDHandler12734966
Ref: 3e1112734966
Ref: library/xml sax reader xml sax xmlreader XMLReader setDTDHandler12735055
Ref: 3e1212735055
Ref: library/xml sax reader xml sax xmlreader XMLReader getEntityResolver12735222
Ref: 3e1312735222
Ref: library/xml sax reader xml sax xmlreader XMLReader setEntityResolver12735319
Ref: 3e1412735319
Ref: library/xml sax reader xml sax xmlreader XMLReader getErrorHandler12735611
Ref: 3e1512735611
Ref: library/xml sax reader xml sax xmlreader XMLReader setErrorHandler12735704
Ref: 3e1612735704
Ref: library/xml sax reader xml sax xmlreader XMLReader setLocale12735908
Ref: 3e1712735908
Ref: library/xml sax reader xml sax xmlreader XMLReader getFeature12736274
Ref: 3e1812736274
Ref: library/xml sax reader xml sax xmlreader XMLReader setFeature12736556
Ref: 3dc112736556
Ref: library/xml sax reader xml sax xmlreader XMLReader getProperty12736845
Ref: 3e1912736845
Ref: library/xml sax reader xml sax xmlreader XMLReader setProperty12737136
Ref: 3e1a12737136
Node: IncrementalParser Objects12737430
Ref: library/xml sax reader incremental-parser-objects12737589
Ref: 3e1b12737589
Ref: library/xml sax reader incrementalparser-objects12737589
Ref: 3e1c12737589
Ref: library/xml sax reader xml sax xmlreader IncrementalParser feed12737747
Ref: 3e1d12737747
Ref: library/xml sax reader xml sax xmlreader IncrementalParser close12737823
Ref: 3e1e12737823
Ref: library/xml sax reader xml sax xmlreader IncrementalParser reset12738062
Ref: 3e1f12738062
Node: Locator Objects12738324
Ref: library/xml sax reader id212738485
Ref: 3e2012738485
Ref: library/xml sax reader locator-objects12738485
Ref: 3e2112738485
Ref: library/xml sax reader xml sax xmlreader Locator getColumnNumber12738596
Ref: 3e2212738596
Ref: library/xml sax reader xml sax xmlreader Locator getLineNumber12738699
Ref: 3e2312738699
Ref: library/xml sax reader xml sax xmlreader Locator getPublicId12738798
Ref: 3e2412738798
Ref: library/xml sax reader xml sax xmlreader Locator getSystemId12738892
Ref: 3e2512738892
Node: InputSource Objects12738986
Ref: library/xml sax reader input-source-objects12739146
Ref: 3e2612739146
Ref: library/xml sax reader inputsource-objects12739146
Ref: 3e2712739146
Ref: library/xml sax reader xml sax xmlreader InputSource setPublicId12739207
Ref: 3e2812739207
Ref: library/xml sax reader xml sax xmlreader InputSource getPublicId12739315
Ref: 3e2912739315
Ref: library/xml sax reader xml sax xmlreader InputSource setSystemId12739424
Ref: 3e2a12739424
Ref: library/xml sax reader xml sax xmlreader InputSource getSystemId12739532
Ref: 3e2b12739532
Ref: library/xml sax reader xml sax xmlreader InputSource setEncoding12739641
Ref: 3e2c12739641
Ref: library/xml sax reader xml sax xmlreader InputSource getEncoding12740030
Ref: 3e2d12740030
Ref: library/xml sax reader xml sax xmlreader InputSource setByteStream12740124
Ref: 3e2e12740124
Ref: library/xml sax reader xml sax xmlreader InputSource getByteStream12740557
Ref: 3e2f12740557
Ref: library/xml sax reader xml sax xmlreader InputSource setCharacterStream12740765
Ref: 3e3012740765
Ref: library/xml sax reader xml sax xmlreader InputSource getCharacterStream12741079
Ref: 3e3112741079
Node: The Attributes Interface12741180
Ref: library/xml sax reader attributes-objects12741351
Ref: 3de312741351
Ref: library/xml sax reader the-attributes-interface12741351
Ref: 3e3212741351
Ref: library/xml sax reader xml sax xmlreader Attributes getLength12741681
Ref: 3e3312741681
Ref: library/xml sax reader xml sax xmlreader Attributes getNames12741757
Ref: 3e3412741757
Ref: library/xml sax reader xml sax xmlreader Attributes getType12741835
Ref: 3e3512741835
Ref: library/xml sax reader xml sax xmlreader Attributes getValue12741960
Ref: 3e3612741960
Node: The AttributesNS Interface12742044
Ref: library/xml sax reader attributes-ns-objects12742187
Ref: 3de512742187
Ref: library/xml sax reader the-attributesns-interface12742187
Ref: 3e3712742187
Ref: library/xml sax reader xml sax xmlreader AttributesNS getValueByQName12742520
Ref: 3e3812742520
Ref: library/xml sax reader xml sax xmlreader AttributesNS getNameByQName12742614
Ref: 3e3912742614
Ref: library/xml sax reader xml sax xmlreader AttributesNS getQNameByName12742737
Ref: 3e3a12742737
Ref: library/xml sax reader xml sax xmlreader AttributesNS getQNames12742858
Ref: 3e3b12742858
Node: xml parsers expat — Fast XML parsing using Expat12742949
Ref: library/pyexpat doc12743126
Ref: 3e3c12743126
Ref: library/pyexpat module-xml parsers expat12743126
Ref: 12c12743126
Ref: library/pyexpat translation-repo12743126
Ref: 3e3d12743126
Ref: library/pyexpat xml-parsers-expat-fast-xml-parsing-using-expat12743126
Ref: 3e3e12743126
Ref: library/pyexpat xml parsers expat ExpatError12744088
Ref: 148012744088
Ref: library/pyexpat xml parsers expat error12744298
Ref: 3e4012744298
Ref: library/pyexpat xml parsers expat XMLParserType12744378
Ref: 3e4112744378
Ref: library/pyexpat xml parsers expat ErrorString12744575
Ref: 3e4312744575
Ref: library/pyexpat xml parsers expat ParserCreate12744698
Ref: 3e4212744698
Ref: library/pyexpat xmlparser-non-root12745228
Ref: 3e4412745228
Ref: xml parsers expat — Fast XML parsing using Expat-Footnote-112747374
Ref: xml parsers expat — Fast XML parsing using Expat-Footnote-212747679
Node: XMLParser Objects<2>12747712
Ref: library/pyexpat id212747849
Ref: 3e4512747849
Ref: library/pyexpat xmlparser-objects12747849
Ref: 17a312747849
Ref: library/pyexpat xml parsers expat xmlparser Parse12747959
Ref: 3e4612747959
Ref: library/pyexpat xml parsers expat xmlparser ParseFile12748337
Ref: 3e4712748337
Ref: library/pyexpat xml parsers expat xmlparser SetBase12748557
Ref: 3e4812748557
Ref: library/pyexpat xml parsers expat xmlparser GetBase12748973
Ref: 3e4c12748973
Ref: library/pyexpat xml parsers expat xmlparser GetInputContext12749171
Ref: 3e4d12749171
Ref: library/pyexpat xml parsers expat xmlparser ExternalEntityParserCreate12749454
Ref: 17d612749454
Ref: library/pyexpat xml parsers expat xmlparser SetParamEntityParsing12749969
Ref: 3e5012749969
Ref: library/pyexpat xml parsers expat xmlparser UseForeignDTD12750334
Ref: 3e5112750334
Ref: library/pyexpat xml parsers expat xmlparser SetReparseDeferralEnabled12751321
Ref: 57912751321
Ref: library/pyexpat xml parsers expat xmlparser GetReparseDeferralEnabled12752837
Ref: 57812752837
Ref: library/pyexpat xml parsers expat xmlparser SetAllocTrackerActivationThreshold12753117
Ref: 17a112753117
Ref: library/pyexpat xml parsers expat xmlparser SetAllocTrackerMaximumAmplification12753712
Ref: 17a212753712
Ref: library/pyexpat xml parsers expat xmlparser buffer_size12755176
Ref: 3e5612755176
Ref: library/pyexpat xml parsers expat xmlparser buffer_text12755438
Ref: 16c912755438
Ref: library/pyexpat xml parsers expat xmlparser buffer_used12755984
Ref: 3e5812755984
Ref: library/pyexpat xml parsers expat xmlparser ordered_attributes12756257
Ref: 3e4e12756257
Ref: library/pyexpat xml parsers expat xmlparser specified_attributes12756749
Ref: 3e4f12756749
Ref: library/pyexpat xml parsers expat xmlparser ErrorByteIndex12757556
Ref: 3e5912757556
Ref: library/pyexpat xml parsers expat xmlparser ErrorCode12757642
Ref: 3e5a12757642
Ref: library/pyexpat xml parsers expat xmlparser ErrorColumnNumber12757873
Ref: 3e5b12757873
Ref: library/pyexpat xml parsers expat xmlparser ErrorLineNumber12757965
Ref: 3e5c12757965
Ref: library/pyexpat xml parsers expat xmlparser CurrentByteIndex12758458
Ref: 3e5d12758458
Ref: library/pyexpat xml parsers expat xmlparser CurrentColumnNumber12758547
Ref: 3e5e12758547
Ref: library/pyexpat xml parsers expat xmlparser CurrentLineNumber12758642
Ref: 3e5f12758642
Ref: library/pyexpat xml parsers expat xmlparser XmlDeclHandler12759055
Ref: 3e6012759055
Ref: library/pyexpat xml parsers expat xmlparser StartDoctypeDeclHandler12759666
Ref: 3e5212759666
Ref: library/pyexpat xml parsers expat xmlparser EndDoctypeDeclHandler12760219
Ref: 3e5312760219
Ref: library/pyexpat xml parsers expat xmlparser ElementDeclHandler12760385
Ref: 179c12760385
Ref: library/pyexpat xml parsers expat xmlparser AttlistDeclHandler12760599
Ref: 3e6112760599
Ref: library/pyexpat xml parsers expat xmlparser StartElementHandler12761502
Ref: 3e6212761502
Ref: library/pyexpat xml parsers expat xmlparser EndElementHandler12761899
Ref: 3e6312761899
Ref: library/pyexpat xml parsers expat xmlparser ProcessingInstructionHandler12761990
Ref: 3e6412761990
Ref: library/pyexpat xml parsers expat xmlparser CharacterDataHandler12762104
Ref: 3e5712762104
Ref: library/pyexpat xml parsers expat xmlparser UnparsedEntityDeclHandler12762769
Ref: 3e4b12762769
Ref: library/pyexpat xml parsers expat xmlparser EntityDeclHandler12763162
Ref: 3e6712763162
Ref: library/pyexpat xml parsers expat xmlparser NotationDeclHandler12763907
Ref: 3e4a12763907
Ref: library/pyexpat xml parsers expat xmlparser StartNamespaceDeclHandler12764198
Ref: 3e6812764198
Ref: library/pyexpat xml parsers expat xmlparser EndNamespaceDeclHandler12764476
Ref: 3e6912764476
Ref: library/pyexpat xml parsers expat xmlparser CommentHandler12764999
Ref: 3e6a12764999
Ref: library/pyexpat xml parsers expat xmlparser StartCdataSectionHandler12765185
Ref: 3e6512765185
Ref: library/pyexpat xml parsers expat xmlparser EndCdataSectionHandler12765422
Ref: 3e6612765422
Ref: library/pyexpat xml parsers expat xmlparser DefaultHandler12765515
Ref: 3e6b12765515
Ref: library/pyexpat xml parsers expat xmlparser DefaultHandlerExpand12765800
Ref: 3e6c12765800
Ref: library/pyexpat xml parsers expat xmlparser NotStandaloneHandler12766040
Ref: 3e6d12766040
Ref: library/pyexpat xml parsers expat xmlparser ExternalEntityRefHandler12766562
Ref: 3e4912766562
Ref: XMLParser Objects<2>-Footnote-112767977
Ref: XMLParser Objects<2>-Footnote-212768042
Node: ExpatError Exceptions12768093
Ref: library/pyexpat expaterror-exceptions12768250
Ref: 3e6e12768250
Ref: library/pyexpat expaterror-objects12768250
Ref: 3e3f12768250
Ref: library/pyexpat xml parsers expat ExpatError code12768392
Ref: 3e6f12768392
Ref: library/pyexpat xml parsers expat ExpatError lineno12769041
Ref: 3e5412769041
Ref: library/pyexpat xml parsers expat ExpatError offset12769168
Ref: 3e5512769168
Node: Example<10>12769309
Ref: library/pyexpat example12769472
Ref: 3e7212769472
Ref: library/pyexpat expat-example12769472
Ref: 3e7312769472
Node: Content Model Descriptions12770570
Ref: library/pyexpat content-model-descriptions12770733
Ref: 3e7412770733
Ref: library/pyexpat expat-content-models12770733
Ref: 3e7512770733
Ref: library/pyexpat module-xml parsers expat model12770733
Ref: 12e12770733
Node: Expat error constants12772576
Ref: library/pyexpat expat-error-constants12772719
Ref: 3e7612772719
Ref: library/pyexpat expat-errors12772719
Ref: 3e7712772719
Ref: library/pyexpat module-xml parsers expat errors12772719
Ref: 12d12772719
Ref: library/pyexpat xml parsers expat errors codes12773309
Ref: 3e7112773309
Ref: library/pyexpat xml parsers expat errors messages12773448
Ref: 3e7012773448
Ref: library/pyexpat xml parsers expat errors XML_ERROR_ASYNC_ENTITY12773603
Ref: 3e7812773603
Ref: library/pyexpat xml parsers expat errors XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF12773662
Ref: 3e7912773662
Ref: library/pyexpat xml parsers expat errors XML_ERROR_BAD_CHAR_REF12773863
Ref: 3e7a12773863
Ref: library/pyexpat xml parsers expat errors XML_ERROR_BINARY_ENTITY_REF12774058
Ref: 3e7b12774058
Ref: library/pyexpat xml parsers expat errors XML_ERROR_DUPLICATE_ATTRIBUTE12774232
Ref: 3e7c12774232
Ref: library/pyexpat xml parsers expat errors XML_ERROR_INCORRECT_ENCODING12774357
Ref: 3e7d12774357
Ref: library/pyexpat xml parsers expat errors XML_ERROR_INVALID_TOKEN12774422
Ref: 3e7e12774422
Ref: library/pyexpat xml parsers expat errors XML_ERROR_JUNK_AFTER_DOC_ELEMENT12774636
Ref: 3e7f12774636
Ref: library/pyexpat xml parsers expat errors XML_ERROR_MISPLACED_XML_PI12774785
Ref: 3e8012774785
Ref: library/pyexpat xml parsers expat errors XML_ERROR_NO_ELEMENTS12774938
Ref: 3e8112774938
Ref: library/pyexpat xml parsers expat errors XML_ERROR_NO_MEMORY12775113
Ref: 3e8212775113
Ref: library/pyexpat xml parsers expat errors XML_ERROR_PARAM_ENTITY_REF12775225
Ref: 3e8312775225
Ref: library/pyexpat xml parsers expat errors XML_ERROR_PARTIAL_CHAR12775359
Ref: 3e8412775359
Ref: library/pyexpat xml parsers expat errors XML_ERROR_RECURSIVE_ENTITY_REF12775472
Ref: 3e8512775472
Ref: library/pyexpat xml parsers expat errors XML_ERROR_SYNTAX12775674
Ref: 3e8612775674
Ref: library/pyexpat xml parsers expat errors XML_ERROR_TAG_MISMATCH12775780
Ref: 3e8712775780
Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNCLOSED_TOKEN12775900
Ref: 3e8812775900
Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNDEFINED_ENTITY12776084
Ref: 3e8912776084
Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNKNOWN_ENCODING12776210
Ref: 3e8a12776210
Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNCLOSED_CDATA_SECTION12776328
Ref: 3e8b12776328
Ref: library/pyexpat xml parsers expat errors XML_ERROR_EXTERNAL_ENTITY_HANDLING12776442
Ref: 3e8c12776442
Ref: library/pyexpat xml parsers expat errors XML_ERROR_NOT_STANDALONE12776513
Ref: 3e8d12776513
Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNEXPECTED_STATE12776774
Ref: 3e8e12776774
Ref: library/pyexpat xml parsers expat errors XML_ERROR_ENTITY_DECLARED_IN_PE12776837
Ref: 3e8f12776837
Ref: library/pyexpat xml parsers expat errors XML_ERROR_FEATURE_REQUIRES_XML_DTD12776905
Ref: 3e9012776905
Ref: library/pyexpat xml parsers expat errors XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING12777211
Ref: 3e9112777211
Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNBOUND_PREFIX12777484
Ref: 3e9212777484
Ref: library/pyexpat xml parsers expat errors XML_ERROR_UNDECLARING_PREFIX12777626
Ref: 3e9312777626
Ref: library/pyexpat xml parsers expat errors XML_ERROR_INCOMPLETE_PE12777787
Ref: 3e9412777787
Ref: library/pyexpat xml parsers expat errors XML_ERROR_XML_DECL12777901
Ref: 3e9512777901
Ref: library/pyexpat xml parsers expat errors XML_ERROR_TEXT_DECL12778013
Ref: 3e9612778013
Ref: library/pyexpat xml parsers expat errors XML_ERROR_PUBLICID12778149
Ref: 3e9712778149
Ref: library/pyexpat xml parsers expat errors XML_ERROR_SUSPENDED12778271
Ref: 3e9812778271
Ref: library/pyexpat xml parsers expat errors XML_ERROR_NOT_SUSPENDED12778495
Ref: 3e9912778495
Ref: library/pyexpat xml parsers expat errors XML_ERROR_ABORTED12778647
Ref: 3e9a12778647
Ref: library/pyexpat xml parsers expat errors XML_ERROR_FINISHED12778759
Ref: 3e9b12778759
Ref: library/pyexpat xml parsers expat errors XML_ERROR_SUSPEND_PE12779005
Ref: 3e9c12779005
Ref: library/pyexpat xml parsers expat errors XML_ERROR_RESERVED_PREFIX_XML12779062
Ref: 3e9d12779062
Ref: library/pyexpat xml parsers expat errors XML_ERROR_RESERVED_PREFIX_XMLNS12779248
Ref: 3e9e12779248
Ref: library/pyexpat xml parsers expat errors XML_ERROR_RESERVED_NAMESPACE_URI12779410
Ref: 3e9f12779410
Ref: library/pyexpat xml parsers expat errors XML_ERROR_INVALID_ARGUMENT12779620
Ref: 3ea012779620
Ref: library/pyexpat xml parsers expat errors XML_ERROR_NO_BUFFER12779741
Ref: 3ea112779741
Ref: library/pyexpat xml parsers expat errors XML_ERROR_AMPLIFICATION_LIMIT_BREACH12779855
Ref: 3ea212779855
Ref: library/pyexpat xml parsers expat errors XML_ERROR_NOT_STARTED12780022
Ref: 18bb12780022
Node: Internet Protocols and Support12780182
Ref: library/internet doc12780347
Ref: 3ea312780347
Ref: library/internet internet12780347
Ref: 3ea412780347
Ref: library/internet internet-protocols-and-support12780347
Ref: 3ea512780347
Ref: library/internet translation-repo12780347
Ref: 3ea612780347
Node: webbrowser — Convenient web-browser controller12782290
Ref: library/webbrowser doc12782469
Ref: 3ea712782469
Ref: library/webbrowser module-webbrowser12782469
Ref: 11b12782469
Ref: library/webbrowser webbrowser-convenient-web-browser-controller12782469
Ref: 3ea812782469
Ref: webbrowser — Convenient web-browser controller-Footnote-112784951
Ref: webbrowser — Convenient web-browser controller-Footnote-212785021
Node: Command-line interface<6>12785154
Ref: library/webbrowser command-line-interface12785299
Ref: 3ea912785299
Ref: library/webbrowser webbrowser-cli12785299
Ref: 3eaa12785299
Ref: library/webbrowser cmdoption-webbrowser-n12785531
Ref: 3eab12785531
Ref: library/webbrowser cmdoption-webbrowser-new-window12785531
Ref: 3eac12785531
Ref: library/webbrowser cmdoption-webbrowser-t12785619
Ref: 3ead12785619
Ref: library/webbrowser cmdoption-webbrowser-new-tab12785619
Ref: 3eae12785619
Ref: library/webbrowser webbrowser Error12785896
Ref: 3eaf12785896
Ref: library/webbrowser webbrowser open12786027
Ref: 187112786027
Ref: library/webbrowser webbrowser open_new12786926
Ref: 3eb012786926
Ref: library/webbrowser webbrowser open_new_tab12787185
Ref: 3eb112787185
Ref: library/webbrowser webbrowser get12787454
Ref: 3eb212787454
Ref: library/webbrowser webbrowser register12787682
Ref: 3eb312787682
Node: Browser controller objects12794041
Ref: library/webbrowser browser-controller-objects12794186
Ref: 3eb412794186
Ref: library/webbrowser browser-controllers12794186
Ref: 3eb512794186
Ref: library/webbrowser webbrowser controller name12794403
Ref: 59a12794403
Ref: library/webbrowser webbrowser controller open12794480
Ref: 3eb612794480
Ref: library/webbrowser webbrowser controller open_new12794742
Ref: 3eb712794742
Ref: library/webbrowser webbrowser controller open_new_tab12794961
Ref: 3eb812794961
Node: wsgiref — WSGI Utilities and Reference Implementation12795159
Ref: library/wsgiref doc12795378
Ref: 3eb912795378
Ref: library/wsgiref module-wsgiref12795378
Ref: 11e12795378
Ref: library/wsgiref translation-repo12795378
Ref: 3eba12795378
Ref: library/wsgiref wsgiref-wsgi-utilities-and-reference-implementation12795378
Ref: 3ebb12795378
Ref: wsgiref — WSGI Utilities and Reference Implementation-Footnote-112797398
Ref: wsgiref — WSGI Utilities and Reference Implementation-Footnote-212797462
Ref: wsgiref — WSGI Utilities and Reference Implementation-Footnote-312797504
Node: wsgiref util – WSGI environment utilities12797541
Ref: library/wsgiref module-wsgiref util12797731
Ref: 12312797731
Ref: library/wsgiref wsgiref-util-wsgi-environment-utilities12797731
Ref: 3ebc12797731
Ref: library/wsgiref wsgiref util guess_scheme12798275
Ref: 3ebe12798275
Ref: library/wsgiref wsgiref util request_uri12798913
Ref: 3ebf12798913
Ref: library/wsgiref wsgiref util application_uri12799237
Ref: 3ec012799237
Ref: library/wsgiref wsgiref util shift_path_info12799503
Ref: 3ec112799503
Ref: library/wsgiref wsgiref util setup_testing_defaults12801167
Ref: 3ec212801167
Ref: library/wsgiref wsgiref util is_hop_by_hop12802911
Ref: 1a2312802911
Ref: library/wsgiref wsgiref util FileWrapper12803082
Ref: 94012803082
Ref: wsgiref util – WSGI environment utilities-Footnote-112804331
Ref: wsgiref util – WSGI environment utilities-Footnote-212804373
Ref: wsgiref util – WSGI environment utilities-Footnote-312804415
Ref: wsgiref util – WSGI environment utilities-Footnote-412804457
Ref: wsgiref util – WSGI environment utilities-Footnote-512804499
Node: wsgiref headers – WSGI response header tools12804558
Ref: library/wsgiref module-wsgiref headers12804808
Ref: 12012804808
Ref: library/wsgiref wsgiref-headers-wsgi-response-header-tools12804808
Ref: 3ec512804808
Ref: library/wsgiref wsgiref headers Headers12805071
Ref: 109a12805071
Ref: library/wsgiref wsgiref headers Headers get_all12807358
Ref: 3ec612807358
Ref: library/wsgiref wsgiref headers Headers add_header12807795
Ref: 3ec712807795
Ref: wsgiref headers – WSGI response header tools-Footnote-112808937
Node: wsgiref simple_server – a simple WSGI HTTP server12808979
Ref: library/wsgiref module-wsgiref simple_server12809231
Ref: 12112809231
Ref: library/wsgiref wsgiref-simple-server-a-simple-wsgi-http-server12809231
Ref: 3ec812809231
Ref: library/wsgiref wsgiref simple_server make_server12809825
Ref: 3ec912809825
Ref: library/wsgiref wsgiref simple_server demo_app12810665
Ref: 3ec312810665
Ref: library/wsgiref wsgiref simple_server WSGIServer12811199
Ref: 3ecb12811199
Ref: library/wsgiref wsgiref simple_server WSGIServer set_app12811954
Ref: 3ecd12811954
Ref: library/wsgiref wsgiref simple_server WSGIServer get_app12812099
Ref: 3ece12812099
Ref: library/wsgiref wsgiref simple_server WSGIRequestHandler12812442
Ref: 3ecf12812442
Ref: library/wsgiref wsgiref simple_server WSGIRequestHandler get_environ12813059
Ref: 3ed012813059
Ref: library/wsgiref wsgiref simple_server WSGIRequestHandler get_stderr12813561
Ref: 3ed112813561
Ref: library/wsgiref wsgiref simple_server WSGIRequestHandler handle12813744
Ref: 3ed212813744
Ref: wsgiref simple_server – a simple WSGI HTTP server-Footnote-112814015
Ref: wsgiref simple_server – a simple WSGI HTTP server-Footnote-212814057
Node: wsgiref validate — WSGI conformance checker12814099
Ref: library/wsgiref module-wsgiref validate12814353
Ref: 12412814353
Ref: library/wsgiref wsgiref-validate-wsgi-conformance-checker12814353
Ref: 3ed312814353
Ref: library/wsgiref wsgiref validate validator12815258
Ref: 3ed412815258
Ref: wsgiref validate — WSGI conformance checker-Footnote-112817471
Ref: wsgiref validate — WSGI conformance checker-Footnote-212817513
Ref: wsgiref validate — WSGI conformance checker-Footnote-312817572
Node: wsgiref handlers – server/gateway base classes12817614
Ref: library/wsgiref module-wsgiref handlers12817870
Ref: 11f12817870
Ref: library/wsgiref wsgiref-handlers-server-gateway-base-classes12817870
Ref: 3ed512817870
Ref: library/wsgiref wsgiref handlers CGIHandler12818261
Ref: 3ed612818261
Ref: library/wsgiref wsgiref handlers IISCGIHandler12818911
Ref: 3ed812818911
Ref: library/wsgiref wsgiref handlers BaseCGIHandler12820289
Ref: 3ed712820289
Ref: library/wsgiref wsgiref handlers SimpleHandler12821155
Ref: 3ed912821155
Ref: library/wsgiref wsgiref handlers BaseHandler12822105
Ref: 1dbb12822105
Ref: library/wsgiref wsgiref handlers BaseHandler run12822465
Ref: 3edf12822465
Ref: library/wsgiref wsgiref handlers BaseHandler _write12822804
Ref: 3edd12822804
Ref: library/wsgiref wsgiref handlers BaseHandler _flush12823150
Ref: 3ede12823150
Ref: library/wsgiref wsgiref handlers BaseHandler get_stdin12823359
Ref: 3eda12823359
Ref: library/wsgiref wsgiref handlers BaseHandler get_stderr12823562
Ref: 3edb12823562
Ref: library/wsgiref wsgiref handlers BaseHandler add_cgi_vars12823767
Ref: 3edc12823767
Ref: library/wsgiref wsgiref handlers BaseHandler wsgi_multithread12824319
Ref: 3ee212824319
Ref: library/wsgiref wsgiref handlers BaseHandler wsgi_multiprocess12824610
Ref: 3ee312824610
Ref: library/wsgiref wsgiref handlers BaseHandler wsgi_run_once12824903
Ref: 3ee412824903
Ref: library/wsgiref wsgiref handlers BaseHandler os_environ12825146
Ref: 3ee512825146
Ref: library/wsgiref wsgiref handlers BaseHandler server_software12825652
Ref: 3ee612825652
Ref: library/wsgiref wsgiref handlers BaseHandler get_scheme12826257
Ref: 3ee812826257
Ref: library/wsgiref wsgiref handlers BaseHandler setup_environ12826614
Ref: 3ee912826614
Ref: library/wsgiref wsgiref handlers BaseHandler log_exception12827274
Ref: 3eeb12827274
Ref: library/wsgiref wsgiref handlers BaseHandler traceback_limit12827774
Ref: 3eec12827774
Ref: library/wsgiref wsgiref handlers BaseHandler error_output12827996
Ref: 3eed12827996
Ref: library/wsgiref wsgiref handlers BaseHandler error_status12829176
Ref: 3eee12829176
Ref: library/wsgiref wsgiref handlers BaseHandler error_headers12829381
Ref: 3eef12829381
Ref: library/wsgiref wsgiref handlers BaseHandler error_body12829673
Ref: 3ef012829673
Ref: library/wsgiref wsgiref handlers BaseHandler wsgi_file_wrapper12830015
Ref: 3eea12830015
Ref: library/wsgiref wsgiref handlers BaseHandler sendfile12830288
Ref: 3ef112830288
Ref: library/wsgiref wsgiref handlers BaseHandler origin_server12830864
Ref: 3ee712830864
Ref: library/wsgiref wsgiref handlers BaseHandler http_version12831391
Ref: 3ef212831391
Ref: library/wsgiref wsgiref handlers read_environ12831613
Ref: 13c112831613
Ref: wsgiref handlers – server/gateway base classes-Footnote-112832527
Ref: wsgiref handlers – server/gateway base classes-Footnote-212832569
Ref: wsgiref handlers – server/gateway base classes-Footnote-312832611
Ref: wsgiref handlers – server/gateway base classes-Footnote-412832653
Ref: wsgiref handlers – server/gateway base classes-Footnote-512832695
Node: wsgiref types – WSGI types for static type checking12832737
Ref: library/wsgiref module-wsgiref types12832960
Ref: 12212832960
Ref: library/wsgiref wsgiref-types-wsgi-types-for-static-type-checking12832960
Ref: 3ef312832960
Ref: library/wsgiref wsgiref types StartResponse12833207
Ref: 3eca12833207
Ref: library/wsgiref wsgiref types WSGIEnvironment12833346
Ref: 3ebd12833346
Ref: library/wsgiref wsgiref types WSGIApplication12833448
Ref: 3ef412833448
Ref: library/wsgiref wsgiref types InputStream12833548
Ref: 3ee012833548
Ref: library/wsgiref wsgiref types ErrorStream12833658
Ref: 3ee112833658
Ref: library/wsgiref wsgiref types FileWrapper12833768
Ref: 3ec412833768
Ref: wsgiref types – WSGI types for static type checking-Footnote-112834009
Ref: wsgiref types – WSGI types for static type checking-Footnote-212834051
Ref: wsgiref types – WSGI types for static type checking-Footnote-312834121
Ref: wsgiref types – WSGI types for static type checking-Footnote-412834163
Ref: wsgiref types – WSGI types for static type checking-Footnote-512834229
Ref: wsgiref types – WSGI types for static type checking-Footnote-612834295
Node: Examples<26>12834379
Ref: library/wsgiref examples12834545
Ref: 3ef512834545
Node: urllib — URL handling modules12837375
Ref: library/urllib doc12837600
Ref: 3ef612837600
Ref: library/urllib module-urllib12837600
Ref: 10e12837600
Ref: library/urllib translation-repo12837600
Ref: 3ef712837600
Ref: library/urllib urllib-url-handling-modules12837600
Ref: 3ef812837600
Ref: urllib — URL handling modules-Footnote-112838181
Node: urllib request — Extensible library for opening URLs12838245
Ref: library/urllib request doc12838466
Ref: 3ef912838466
Ref: library/urllib request module-urllib request12838466
Ref: 11112838466
Ref: library/urllib request translation-repo12838466
Ref: 3efa12838466
Ref: library/urllib request urllib-request-extensible-library-for-opening-urls12838466
Ref: 3efb12838466
Ref: library/urllib request urllib request urlopen12839580
Ref: 30712839580
Ref: library/urllib request urllib request install_opener12843105
Ref: 3f0112843105
Ref: library/urllib request urllib request build_opener12843559
Ref: 30912843559
Ref: library/urllib request urllib request pathname2url12844677
Ref: 2bf12844677
Ref: library/urllib request urllib request url2pathname12845803
Ref: 2bd12845803
Ref: library/urllib request urllib request getproxies12847704
Ref: 3efc12847704
Ref: library/urllib request urllib request Request12848845
Ref: 11da12848845
Ref: library/urllib request urllib request OpenerDirector12853369
Ref: 3eff12853369
Ref: library/urllib request urllib request BaseHandler12853589
Ref: 3f0212853589
Ref: library/urllib request urllib request HTTPDefaultErrorHandler12853750
Ref: 3f0312853750
Ref: library/urllib request urllib request HTTPRedirectHandler12853944
Ref: 3f0412853944
Ref: library/urllib request urllib request HTTPCookieProcessor12854030
Ref: 3f0912854030
Ref: library/urllib request urllib request ProxyHandler12854133
Ref: 1d9d12854133
Ref: library/urllib request urllib request HTTPPasswordMgr12855223
Ref: 3f0a12855223
Ref: library/urllib request urllib request HTTPPasswordMgrWithDefaultRealm12855341
Ref: 3f0b12855341
Ref: library/urllib request urllib request HTTPPasswordMgrWithPriorAuth12855583
Ref: 109612855583
Ref: library/urllib request urllib request AbstractBasicAuthHandler12855972
Ref: 1c5712855972
Ref: library/urllib request urllib request HTTPBasicAuthHandler12857317
Ref: 3f0e12857317
Ref: library/urllib request urllib request ProxyBasicAuthHandler12857782
Ref: 3f0f12857782
Ref: library/urllib request urllib request AbstractDigestAuthHandler12858123
Ref: 1d5312858123
Ref: library/urllib request urllib request HTTPDigestAuthHandler12858645
Ref: 3f1012858645
Ref: library/urllib request urllib request ProxyDigestAuthHandler12859513
Ref: 3f1112859513
Ref: library/urllib request urllib request HTTPHandler12859855
Ref: efa12859855
Ref: library/urllib request urllib request HTTPSHandler12859941
Ref: 142b12859941
Ref: library/urllib request urllib request FileHandler12860282
Ref: 3f0612860282
Ref: library/urllib request urllib request DataHandler12860346
Ref: 11d912860346
Ref: library/urllib request urllib request FTPHandler12860436
Ref: 3f0512860436
Ref: library/urllib request urllib request CacheFTPHandler12860496
Ref: 1a8112860496
Ref: library/urllib request urllib request UnknownHandler12860626
Ref: 3f0012860626
Ref: library/urllib request urllib request HTTPErrorProcessor12860717
Ref: 3f0712860717
Ref: urllib request — Extensible library for opening URLs-Footnote-112861599
Ref: urllib request — Extensible library for opening URLs-Footnote-212861673
Ref: urllib request — Extensible library for opening URLs-Footnote-312861724
Ref: urllib request — Extensible library for opening URLs-Footnote-412861793
Ref: urllib request — Extensible library for opening URLs-Footnote-512861852
Ref: urllib request — Extensible library for opening URLs-Footnote-612861911
Node: Request Objects12861970
Ref: library/urllib request id112862107
Ref: 3f1212862107
Ref: library/urllib request request-objects12862107
Ref: 3f1312862107
Ref: library/urllib request urllib request Request full_url12862379
Ref: 11dc12862379
Ref: library/urllib request urllib request Request type12862680
Ref: 3f1412862680
Ref: library/urllib request urllib request Request host12862731
Ref: 3f1512862731
Ref: library/urllib request urllib request Request origin_req_host12862858
Ref: 3f1612862858
Ref: library/urllib request urllib request Request selector12862953
Ref: 3f1712862953
Ref: library/urllib request urllib request Request data12863118
Ref: 11dd12863118
Ref: library/urllib request urllib request Request unverifiable12863385
Ref: 3f1812863385
Ref: library/urllib request urllib request Request method12863515
Ref: 11db12863515
Ref: library/urllib request urllib request Request get_method12864232
Ref: 137112864232
Ref: library/urllib request urllib request Request add_header12864662
Ref: 3f0812864662
Ref: library/urllib request urllib request Request add_unredirected_header12865342
Ref: 3f1912865342
Ref: library/urllib request urllib request Request has_header12865468
Ref: 3f1a12865468
Ref: library/urllib request urllib request Request remove_header12865609
Ref: 11df12865609
Ref: library/urllib request urllib request Request get_full_url12865784
Ref: 3f1b12865784
Ref: library/urllib request urllib request Request set_proxy12865947
Ref: 3f1c12865947
Ref: library/urllib request urllib request Request get_header12866200
Ref: 3f1d12866200
Ref: library/urllib request urllib request Request header_items12866366
Ref: 3f1e12866366
Ref: Request Objects-Footnote-112866730
Node: OpenerDirector Objects12866789
Ref: library/urllib request opener-director-objects12866954
Ref: 3f1f12866954
Ref: library/urllib request openerdirector-objects12866954
Ref: 3f2012866954
Ref: library/urllib request urllib request OpenerDirector add_handler12867086
Ref: 3f2112867086
Ref: library/urllib request urllib request OpenerDirector open12868644
Ref: 11de12868644
Ref: library/urllib request urllib request OpenerDirector error12869327
Ref: 3f2612869327
Node: BaseHandler Objects12871121
Ref: library/urllib request base-handler-objects12871298
Ref: 3f2912871298
Ref: library/urllib request basehandler-objects12871298
Ref: 3f2a12871298
Ref: library/urllib request urllib request BaseHandler add_parent12871538
Ref: 3f2b12871538
Ref: library/urllib request urllib request BaseHandler close12871617
Ref: 3f2c12871617
Ref: library/urllib request urllib request BaseHandler parent12871993
Ref: 3f2d12871993
Ref: library/urllib request urllib request BaseHandler default_open12872147
Ref: 3f2712872147
Ref: library/urllib request protocol-open12872840
Ref: 3f2212872840
Ref: library/urllib request urllib request BaseHandler unknown_open12873211
Ref: 3f2812873211
Ref: library/urllib request urllib request BaseHandler http_error_default12873623
Ref: 3f2e12873623
Ref: library/urllib request http-error-nnn12874509
Ref: 3f2312874509
Ref: library/urllib request protocol-request12875013
Ref: 3f2412875013
Ref: library/urllib request protocol-response12875429
Ref: 3f2512875429
Node: HTTPRedirectHandler Objects12876020
Ref: library/urllib request http-redirect-handler12876202
Ref: 3f2f12876202
Ref: library/urllib request httpredirecthandler-objects12876202
Ref: 3f3012876202
Ref: library/urllib request urllib request HTTPRedirectHandler redirect_request12876708
Ref: 3f3112876708
Ref: library/urllib request urllib request HTTPRedirectHandler http_error_30112877795
Ref: 3f3212877795
Ref: library/urllib request urllib request HTTPRedirectHandler http_error_30212878066
Ref: 3f3312878066
Ref: library/urllib request urllib request HTTPRedirectHandler http_error_30312878245
Ref: 3f3412878245
Ref: library/urllib request urllib request HTTPRedirectHandler http_error_30712878428
Ref: 3f3512878428
Ref: library/urllib request urllib request HTTPRedirectHandler http_error_30812878702
Ref: 3f3612878702
Ref: HTTPRedirectHandler Objects-Footnote-112879041
Ref: HTTPRedirectHandler Objects-Footnote-212879100
Node: HTTPCookieProcessor Objects12879159
Ref: library/urllib request http-cookie-processor12879342
Ref: 3f3712879342
Ref: library/urllib request httpcookieprocessor-objects12879342
Ref: 3f3812879342
Ref: library/urllib request urllib request HTTPCookieProcessor cookiejar12879481
Ref: 3f3912879481
Node: ProxyHandler Objects12879609
Ref: library/urllib request proxy-handler12879788
Ref: 3f3b12879788
Ref: library/urllib request proxyhandler-objects12879788
Ref: 3f3c12879788
Node: HTTPPasswordMgr Objects12880266
Ref: library/urllib request http-password-mgr12880454
Ref: 3f0c12880454
Ref: library/urllib request httppasswordmgr-objects12880454
Ref: 3f3d12880454
Ref: library/urllib request urllib request HTTPPasswordMgr add_password12880640
Ref: 3f3e12880640
Ref: library/urllib request urllib request HTTPPasswordMgr find_user_password12880987
Ref: 1bbe12880987
Node: HTTPPasswordMgrWithPriorAuth Objects12881361
Ref: library/urllib request http-password-mgr-with-prior-auth12881561
Ref: 3f0d12881561
Ref: library/urllib request httppasswordmgrwithpriorauth-objects12881561
Ref: 3f3f12881561
Ref: library/urllib request urllib request HTTPPasswordMgrWithPriorAuth add_password12881815
Ref: 3f4012881815
Ref: library/urllib request urllib request HTTPPasswordMgrWithPriorAuth find_user_password12882229
Ref: 3f4112882229
Ref: library/urllib request urllib request HTTPPasswordMgrWithPriorAuth update_authenticated12882388
Ref: 3f4212882388
Ref: library/urllib request urllib request HTTPPasswordMgrWithPriorAuth is_authenticated12882584
Ref: 1bbf12882584
Node: AbstractBasicAuthHandler Objects12882760
Ref: library/urllib request abstract-basic-auth-handler12882965
Ref: 3f4312882965
Ref: library/urllib request abstractbasicauthhandler-objects12882965
Ref: 3f4412882965
Ref: library/urllib request urllib request AbstractBasicAuthHandler http_error_auth_reqed12883050
Ref: 3f4512883050
Node: HTTPBasicAuthHandler Objects12883871
Ref: library/urllib request http-basic-auth-handler12884069
Ref: 3f4612884069
Ref: library/urllib request httpbasicauthhandler-objects12884069
Ref: 3f4712884069
Ref: library/urllib request urllib request HTTPBasicAuthHandler http_error_40112884148
Ref: 3f4812884148
Node: ProxyBasicAuthHandler Objects12884305
Ref: library/urllib request proxy-basic-auth-handler12884504
Ref: 3f4912884504
Ref: library/urllib request proxybasicauthhandler-objects12884504
Ref: 3f4a12884504
Ref: library/urllib request urllib request ProxyBasicAuthHandler http_error_40712884585
Ref: 3f4b12884585
Node: AbstractDigestAuthHandler Objects12884743
Ref: library/urllib request abstract-digest-auth-handler12884943
Ref: 3f4c12884943
Ref: library/urllib request abstractdigestauthhandler-objects12884943
Ref: 3f4d12884943
Ref: library/urllib request urllib request AbstractDigestAuthHandler http_error_auth_reqed12885032
Ref: 3f4e12885032
Node: HTTPDigestAuthHandler Objects12885410
Ref: library/urllib request http-digest-auth-handler12885611
Ref: 3f4f12885611
Ref: library/urllib request httpdigestauthhandler-objects12885611
Ref: 3f5012885611
Ref: library/urllib request urllib request HTTPDigestAuthHandler http_error_40112885692
Ref: 3f5112885692
Node: ProxyDigestAuthHandler Objects12885850
Ref: library/urllib request proxy-digest-auth-handler12886037
Ref: 3f5212886037
Ref: library/urllib request proxydigestauthhandler-objects12886037
Ref: 3f5312886037
Ref: library/urllib request urllib request ProxyDigestAuthHandler http_error_40712886120
Ref: 3f5412886120
Node: HTTPHandler Objects12886279
Ref: library/urllib request http-handler-objects12886457
Ref: 3f5512886457
Ref: library/urllib request httphandler-objects12886457
Ref: 3f5612886457
Ref: library/urllib request urllib request HTTPHandler http_open12886518
Ref: 3f5712886518
Node: HTTPSHandler Objects12886654
Ref: library/urllib request https-handler-objects12886821
Ref: 3f5812886821
Ref: library/urllib request httpshandler-objects12886821
Ref: 3f5912886821
Ref: library/urllib request urllib request HTTPSHandler https_open12886884
Ref: 3f5a12886884
Node: FileHandler Objects12887023
Ref: library/urllib request file-handler-objects12887190
Ref: 3f5b12887190
Ref: library/urllib request filehandler-objects12887190
Ref: 3f5c12887190
Ref: library/urllib request urllib request FileHandler file_open12887251
Ref: 3f5d12887251
Node: DataHandler Objects12887556
Ref: library/urllib request data-handler-objects12887721
Ref: 3f5e12887721
Ref: library/urllib request datahandler-objects12887721
Ref: 3f5f12887721
Ref: library/urllib request urllib request DataHandler data_open12887782
Ref: 3f6012887782
Ref: DataHandler Objects-Footnote-112888340
Node: FTPHandler Objects12888399
Ref: library/urllib request ftp-handler-objects12888568
Ref: 3f6112888568
Ref: library/urllib request ftphandler-objects12888568
Ref: 3f6212888568
Ref: library/urllib request urllib request FTPHandler ftp_open12888627
Ref: 3f6312888627
Node: CacheFTPHandler Objects12888775
Ref: library/urllib request cacheftp-handler-objects12888947
Ref: 3f6412888947
Ref: library/urllib request cacheftphandler-objects12888947
Ref: 3f6512888947
Ref: library/urllib request urllib request CacheFTPHandler setTimeout12889129
Ref: 3f6612889129
Ref: library/urllib request urllib request CacheFTPHandler setMaxConns12889222
Ref: 3f6712889222
Node: UnknownHandler Objects12889322
Ref: library/urllib request unknown-handler-objects12889502
Ref: 3f6812889502
Ref: library/urllib request unknownhandler-objects12889502
Ref: 3f6912889502
Ref: library/urllib request urllib request UnknownHandler unknown_open12889569
Ref: 3f6a12889569
Node: HTTPErrorProcessor Objects12889659
Ref: library/urllib request http-error-processor-objects12889828
Ref: 3f6b12889828
Ref: library/urllib request httperrorprocessor-objects12889828
Ref: 3f6c12889828
Ref: library/urllib request urllib request HTTPErrorProcessor http_response12889903
Ref: 3f6d12889903
Ref: library/urllib request urllib request HTTPErrorProcessor https_response12890374
Ref: 3f6e12890374
Node: Examples<27>12890537
Ref: library/urllib request examples12890700
Ref: 3f6f12890700
Ref: library/urllib request urllib-request-examples12890700
Ref: 3f7012890700
Ref: library/urllib request urllib-examples12896590
Ref: 3f7212896590
Node: Legacy interface12898137
Ref: library/urllib request legacy-interface12898301
Ref: 3f7312898301
Ref: library/urllib request urllib request urlretrieve12898532
Ref: 30812898532
Ref: library/urllib request urllib request urlcleanup12901201
Ref: 1da412901201
Node: urllib request Restrictions12901360
Ref: library/urllib request urllib-request-restrictions12901503
Ref: 3f7512901503
Node: urllib response — Response classes used by urllib12903978
Ref: library/urllib request module-urllib response12904211
Ref: 11212904211
Ref: library/urllib request urllib-response-response-classes-used-by-urllib12904211
Ref: 3f7612904211
Ref: library/urllib request urllib response addinfourl12904675
Ref: 3efd12904675
Ref: library/urllib request urllib response addinfourl url12904715
Ref: 18d012904715
Ref: library/urllib request urllib response addinfourl headers12904847
Ref: 3f7712904847
Ref: library/urllib request urllib response addinfourl status12904986
Ref: 3f7812904986
Ref: library/urllib request urllib response addinfourl geturl12905090
Ref: 3f7912905090
Ref: library/urllib request urllib response addinfourl info12905209
Ref: 3f7a12905209
Ref: library/urllib request urllib response addinfourl code12905330
Ref: 3f7b12905330
Ref: library/urllib request urllib response addinfourl getcode12905450
Ref: 3f7c12905450
Node: urllib parse — Parse URLs into components12905573
Ref: library/urllib parse doc12905811
Ref: 3f7d12905811
Ref: library/urllib parse module-urllib parse12905811
Ref: 11012905811
Ref: library/urllib parse translation-repo12905811
Ref: 3f7e12905811
Ref: library/urllib parse urllib-parse-parse-urls-into-components12905811
Ref: 3f7f12905811
Ref: urllib parse — Parse URLs into components-Footnote-112907830
Ref: urllib parse — Parse URLs into components-Footnote-212907902
Ref: urllib parse — Parse URLs into components-Footnote-312907961
Node: URL Parsing12908020
Ref: library/urllib parse url-parsing12908140
Ref: 3f8012908140
Ref: library/urllib parse urllib parse urlparse12908313
Ref: 36212908313
Ref: library/urllib parse urllib parse parse_qs12916268
Ref: 31f12916268
Ref: library/urllib parse urllib parse parse_qsl12918658
Ref: 31e12918658
Ref: library/urllib parse urllib parse urlunparse12920710
Ref: 192712920710
Ref: library/urllib parse urllib parse urlsplit12921112
Ref: f3c12921112
Ref: library/urllib parse urllib parse urlunsplit12925756
Ref: 192612925756
Ref: library/urllib parse urllib parse urljoin12926200
Ref: 109812926200
Ref: library/urllib parse urllib parse urldefrag12927943
Ref: 144f12927943
Ref: library/urllib parse urllib parse unwrap12929293
Ref: 3f8312929293
Ref: URL Parsing-Footnote-112929641
Ref: URL Parsing-Footnote-212929700
Ref: URL Parsing-Footnote-312929759
Ref: URL Parsing-Footnote-412929818
Ref: URL Parsing-Footnote-512929880
Node: URL parsing security12929939
Ref: library/urllib parse id112930095
Ref: 3f8412930095
Ref: library/urllib parse url-parsing-security12930095
Ref: 3f8212930095
Ref: URL parsing security-Footnote-112931553
Ref: URL parsing security-Footnote-212931615
Node: Parsing ASCII Encoded Bytes12931674
Ref: library/urllib parse id212931843
Ref: 3f8512931843
Ref: library/urllib parse parsing-ascii-encoded-bytes12931843
Ref: 145112931843
Node: Structured Parse Results12933974
Ref: library/urllib parse structured-parse-results12934134
Ref: 3f8612934134
Ref: library/urllib parse urlparse-result-object12934134
Ref: 3f8112934134
Ref: library/urllib parse urllib parse urllib parse SplitResult geturl12934551
Ref: 3f8712934551
Ref: library/urllib parse urllib parse DefragResult12935675
Ref: 3f8812935675
Ref: library/urllib parse urllib parse ParseResult12935937
Ref: 3f8a12935937
Ref: library/urllib parse urllib parse SplitResult12936209
Ref: 3f8c12936209
Ref: library/urllib parse urllib parse DefragResultBytes12936615
Ref: 3f8912936615
Ref: library/urllib parse urllib parse ParseResultBytes12936879
Ref: 3f8b12936879
Ref: library/urllib parse urllib parse SplitResultBytes12937181
Ref: 3f8d12937181
Node: URL Quoting12937475
Ref: library/urllib parse url-quoting12937599
Ref: 3f8e12937599
Ref: library/urllib parse urllib parse quote12938002
Ref: d9e12938002
Ref: library/urllib parse urllib parse quote_plus12939380
Ref: 145012939380
Ref: library/urllib parse urllib parse quote_from_bytes12939873
Ref: 1b3912939873
Ref: library/urllib parse urllib parse unquote12940166
Ref: 1ae312940166
Ref: library/urllib parse urllib parse unquote_plus12940952
Ref: 3f8f12940952
Ref: library/urllib parse urllib parse unquote_to_bytes12941292
Ref: 1ae412941292
Ref: library/urllib parse urllib parse urlencode12941725
Ref: 109712941725
Ref: URL Quoting-Footnote-112945794
Ref: URL Quoting-Footnote-212945853
Ref: URL Quoting-Footnote-312945912
Ref: URL Quoting-Footnote-412945949
Ref: URL Quoting-Footnote-512946008
Ref: URL Quoting-Footnote-612946067
Ref: URL Quoting-Footnote-712946126
Ref: URL Quoting-Footnote-812946185
Ref: URL Quoting-Footnote-912946244
Node: urllib error — Exception classes raised by urllib request12946303
Ref: library/urllib error doc12946534
Ref: 3f9012946534
Ref: library/urllib error module-urllib error12946534
Ref: 10f12946534
Ref: library/urllib error translation-repo12946534
Ref: 3f9112946534
Ref: library/urllib error urllib-error-exception-classes-raised-by-urllib-request12946534
Ref: 3f9212946534
Ref: library/urllib error urllib error URLError12947032
Ref: 2be12947032
Ref: library/urllib error urllib error URLError reason12947210
Ref: 3f9312947210
Ref: library/urllib error urllib error HTTPError12947501
Ref: 11e012947501
Ref: library/urllib error urllib error HTTPError url12947885
Ref: 3f9412947885
Ref: library/urllib error urllib error HTTPError code12947982
Ref: 3f9512947982
Ref: library/urllib error urllib error HTTPError reason12948242
Ref: 3f9712948242
Ref: library/urllib error urllib error HTTPError headers12948384
Ref: 11e112948384
Ref: library/urllib error urllib error HTTPError fp12948585
Ref: 3f9812948585
Ref: library/urllib error urllib error ContentTooShortError12948683
Ref: 3f7412948683
Ref: library/urllib error urllib error ContentTooShortError content12948953
Ref: 3f9912948953
Ref: urllib error — Exception classes raised by urllib request-Footnote-112949077
Ref: urllib error — Exception classes raised by urllib request-Footnote-212949149
Node: urllib robotparser — Parser for robots txt12949208
Ref: library/urllib robotparser doc12949417
Ref: 3f9a12949417
Ref: library/urllib robotparser module-urllib robotparser12949417
Ref: 11312949417
Ref: library/urllib robotparser translation-repo12949417
Ref: 3f9b12949417
Ref: library/urllib robotparser urllib-robotparser-parser-for-robots-txt12949417
Ref: 3f9c12949417
Ref: library/urllib robotparser urllib robotparser RobotFileParser12949957
Ref: efc12949957
Ref: library/urllib robotparser urllib robotparser RobotFileParser set_url12950131
Ref: 3f9d12950131
Ref: library/urllib robotparser urllib robotparser RobotFileParser read12950225
Ref: 18b912950225
Ref: library/urllib robotparser urllib robotparser RobotFileParser parse12950321
Ref: 1e6b12950321
Ref: library/urllib robotparser urllib robotparser RobotFileParser can_fetch12950391
Ref: 3f9e12950391
Ref: library/urllib robotparser urllib robotparser RobotFileParser mtime12950605
Ref: 3f9f12950605
Ref: library/urllib robotparser urllib robotparser RobotFileParser modified12950833
Ref: 3fa012950833
Ref: library/urllib robotparser urllib robotparser RobotFileParser crawl_delay12950962
Ref: 3fa112950962
Ref: library/urllib robotparser urllib robotparser RobotFileParser request_rate12951366
Ref: 3fa212951366
Ref: library/urllib robotparser urllib robotparser RobotFileParser site_maps12951819
Ref: 1e0a12951819
Ref: urllib robotparser — Parser for robots txt-Footnote-112952741
Node: http — HTTP modules12952820
Ref: library/http doc12953006
Ref: 3fa312953006
Ref: library/http http-http-modules12953006
Ref: 3fa412953006
Ref: library/http module-http12953006
Ref: 7212953006
Ref: library/http translation-repo12953006
Ref: 3fa512953006
Ref: library/http http HTTPStatus12953784
Ref: afe12953784
Ref: http — HTTP modules-Footnote-112954548
Node: HTTP status codes12954621
Ref: library/http http-status-codes12954725
Ref: 3fa612954725
Ref: library/http id112954725
Ref: 3fa712954725
Ref: HTTP status codes-Footnote-112969083
Ref: HTTP status codes-Footnote-212969167
Ref: HTTP status codes-Footnote-312969226
Ref: HTTP status codes-Footnote-412969285
Ref: HTTP status codes-Footnote-512969344
Ref: HTTP status codes-Footnote-612969403
Ref: HTTP status codes-Footnote-712969462
Ref: HTTP status codes-Footnote-812969521
Ref: HTTP status codes-Footnote-912969580
Ref: HTTP status codes-Footnote-1012969639
Ref: HTTP status codes-Footnote-1112969699
Ref: HTTP status codes-Footnote-1212969759
Ref: HTTP status codes-Footnote-1312969819
Ref: HTTP status codes-Footnote-1412969879
Ref: HTTP status codes-Footnote-1512969939
Ref: HTTP status codes-Footnote-1612969999
Ref: HTTP status codes-Footnote-1712970059
Ref: HTTP status codes-Footnote-1812970119
Ref: HTTP status codes-Footnote-1912970179
Ref: HTTP status codes-Footnote-2012970239
Ref: HTTP status codes-Footnote-2112970299
Ref: HTTP status codes-Footnote-2212970359
Ref: HTTP status codes-Footnote-2312970419
Ref: HTTP status codes-Footnote-2412970479
Ref: HTTP status codes-Footnote-2512970539
Ref: HTTP status codes-Footnote-2612970599
Ref: HTTP status codes-Footnote-2712970659
Ref: HTTP status codes-Footnote-2812970719
Ref: HTTP status codes-Footnote-2912970779
Ref: HTTP status codes-Footnote-3012970839
Ref: HTTP status codes-Footnote-3112970899
Ref: HTTP status codes-Footnote-3212970959
Ref: HTTP status codes-Footnote-3312971019
Ref: HTTP status codes-Footnote-3412971079
Ref: HTTP status codes-Footnote-3512971139
Ref: HTTP status codes-Footnote-3612971199
Ref: HTTP status codes-Footnote-3712971259
Ref: HTTP status codes-Footnote-3812971319
Ref: HTTP status codes-Footnote-3912971379
Ref: HTTP status codes-Footnote-4012971439
Ref: HTTP status codes-Footnote-4112971499
Ref: HTTP status codes-Footnote-4212971559
Ref: HTTP status codes-Footnote-4312971619
Ref: HTTP status codes-Footnote-4412971679
Ref: HTTP status codes-Footnote-4512971739
Ref: HTTP status codes-Footnote-4612971799
Ref: HTTP status codes-Footnote-4712971859
Ref: HTTP status codes-Footnote-4812971919
Ref: HTTP status codes-Footnote-4912971979
Ref: HTTP status codes-Footnote-5012972039
Ref: HTTP status codes-Footnote-5112972099
Ref: HTTP status codes-Footnote-5212972159
Ref: HTTP status codes-Footnote-5312972219
Ref: HTTP status codes-Footnote-5412972279
Ref: HTTP status codes-Footnote-5512972339
Ref: HTTP status codes-Footnote-5612972399
Ref: HTTP status codes-Footnote-5712972459
Ref: HTTP status codes-Footnote-5812972519
Ref: HTTP status codes-Footnote-5912972579
Ref: HTTP status codes-Footnote-6012972639
Ref: HTTP status codes-Footnote-6112972699
Ref: HTTP status codes-Footnote-6212972759
Ref: HTTP status codes-Footnote-6312972819
Node: HTTP status category12972879
Ref: library/http http-status-category12973004
Ref: 3fa812973004
Ref: library/http http HTTPMethod12974609
Ref: 3fa912974609
Ref: HTTP status category-Footnote-112975438
Ref: HTTP status category-Footnote-212975497
Ref: HTTP status category-Footnote-312975556
Ref: HTTP status category-Footnote-412975615
Ref: HTTP status category-Footnote-512975674
Node: HTTP methods12975733
Ref: library/http http-methods12975832
Ref: 3faa12975832
Ref: library/http id212975832
Ref: 3fab12975832
Ref: HTTP methods-Footnote-112978209
Ref: HTTP methods-Footnote-212978282
Ref: HTTP methods-Footnote-312978341
Ref: HTTP methods-Footnote-412978400
Ref: HTTP methods-Footnote-512978459
Ref: HTTP methods-Footnote-612978518
Ref: HTTP methods-Footnote-712978577
Ref: HTTP methods-Footnote-812978636
Ref: HTTP methods-Footnote-912978695
Ref: HTTP methods-Footnote-1012978754
Node: http client — HTTP protocol client12978814
Ref: library/http client doc12978986
Ref: 3fac12978986
Ref: library/http client http-client-http-protocol-client12978986
Ref: 3fad12978986
Ref: library/http client module-http client12978986
Ref: 7312978986
Ref: library/http client translation-repo12978986
Ref: 3fae12978986
Ref: library/http client http client HTTPConnection12979844
Ref: d3712979844
Ref: library/http client http client HTTPSConnection12981437
Ref: d3812981437
Ref: library/http client http client HTTPResponse12983157
Ref: 12d612983157
Ref: library/http client http client parse_headers12983542
Ref: 1e1012983542
Ref: library/http client http client HTTPException12984495
Ref: 3fb212984495
Ref: library/http client http client NotConnected12984646
Ref: 3fb312984646
Ref: library/http client http client InvalidURL12984734
Ref: 3fb412984734
Ref: library/http client http client UnknownProtocol12984887
Ref: 3fb512984887
Ref: library/http client http client UnknownTransferEncoding12984978
Ref: 3fb612984978
Ref: library/http client http client UnimplementedFileMode12985077
Ref: 3fb712985077
Ref: library/http client http client IncompleteRead12985174
Ref: 3fb812985174
Ref: library/http client http client ImproperConnectionState12985264
Ref: 3fb912985264
Ref: library/http client http client CannotSendRequest12985363
Ref: 3fba12985363
Ref: library/http client http client CannotSendHeader12985466
Ref: 3fbb12985466
Ref: library/http client http client ResponseNotReady12985568
Ref: 3fbc12985568
Ref: library/http client http client BadStatusLine12985670
Ref: 3fbd12985670
Ref: library/http client http client LineTooLong12985845
Ref: 3fbe12985845
Ref: library/http client http client RemoteDisconnected12986023
Ref: 100c12986023
Ref: library/http client http client HTTP_PORT12986506
Ref: 3fbf12986506
Ref: library/http client http client HTTPS_PORT12986603
Ref: 3fc012986603
Ref: library/http client http client responses12986703
Ref: 3fc112986703
Ref: http client — HTTP protocol client-Footnote-112987164
Ref: http client — HTTP protocol client-Footnote-212987235
Ref: http client — HTTP protocol client-Footnote-312987286
Node: HTTPConnection Objects12987345
Ref: library/http client httpconnection-objects12987469
Ref: 3fc212987469
Ref: library/http client id112987469
Ref: 3fc312987469
Ref: library/http client http client HTTPConnection request12987602
Ref: ea912987602
Ref: library/http client http client HTTPConnection getresponse12991431
Ref: 100b12991431
Ref: library/http client http client HTTPConnection set_debuglevel12992001
Ref: 3fc512992001
Ref: library/http client http client HTTPConnection set_tunnel12992405
Ref: 143012992405
Ref: library/http client http client HTTPConnection get_proxy_response_headers12994088
Ref: 1a5b12994088
Ref: library/http client http client HTTPConnection connect12994369
Ref: 3fc612994369
Ref: library/http client http client HTTPConnection close12994725
Ref: 3fc412994725
Ref: library/http client http client HTTPConnection blocksize12994804
Ref: 3fc712994804
Ref: library/http client http client HTTPConnection putrequest12995096
Ref: 3fc812995096
Ref: library/http client http client HTTPConnection putheader12995645
Ref: 3fc912995645
Ref: library/http client http client HTTPConnection endheaders12995980
Ref: eaa12995980
Ref: library/http client http client HTTPConnection send12997356
Ref: 3fca12997356
Ref: HTTPConnection Objects-Footnote-112997726
Ref: HTTPConnection Objects-Footnote-212997799
Ref: HTTPConnection Objects-Footnote-312997872
Ref: HTTPConnection Objects-Footnote-412997945
Ref: HTTPConnection Objects-Footnote-512998013
Ref: HTTPConnection Objects-Footnote-612998071
Node: HTTPResponse Objects12998130
Ref: library/http client httpresponse-objects12998275
Ref: 3fcb12998275
Ref: library/http client id212998275
Ref: 3fcc12998275
Ref: library/http client http client HTTPResponse read12998695
Ref: 189712998695
Ref: library/http client http client HTTPResponse readinto12998808
Ref: 12d712998808
Ref: library/http client http client HTTPResponse getheader12998997
Ref: 3fcd12998997
Ref: library/http client http client HTTPResponse getheaders12999384
Ref: 3fce12999384
Ref: library/http client http client HTTPResponse fileno12999471
Ref: 3fcf12999471
Ref: library/http client http client HTTPResponse msg12999563
Ref: 3fb012999563
Ref: library/http client http client HTTPResponse version12999782
Ref: 3fd012999782
Ref: library/http client http client HTTPResponse url12999903
Ref: 3fd112999903
Ref: library/http client http client HTTPResponse headers13000033
Ref: 3fd213000033
Ref: library/http client http client HTTPResponse status13000172
Ref: 3fd313000172
Ref: library/http client http client HTTPResponse reason13000246
Ref: 3efe13000246
Ref: library/http client http client HTTPResponse debuglevel13000322
Ref: 3fd413000322
Ref: library/http client http client HTTPResponse closed13000517
Ref: 3fd513000517
Ref: library/http client http client HTTPResponse geturl13000598
Ref: 3fd613000598
Ref: library/http client http client HTTPResponse info13000715
Ref: 3fd713000715
Ref: library/http client http client HTTPResponse getcode13000834
Ref: 3fd813000834
Node: Examples<28>13000955
Ref: library/http client examples13001097
Ref: 3fd913001097
Node: HTTPMessage Objects13003985
Ref: library/http client httpmessage-objects13004098
Ref: 3fda13004098
Ref: library/http client id313004098
Ref: 3fdb13004098
Ref: library/http client http client HTTPMessage13004159
Ref: 3faf13004159
Node: ftplib — FTP protocol client13004381
Ref: library/ftplib doc13004563
Ref: 3fdc13004563
Ref: library/ftplib ftplib-ftp-protocol-client13004563
Ref: 3fdd13004563
Ref: library/ftplib module-ftplib13004563
Ref: 6213004563
Ref: library/ftplib translation-repo13004563
Ref: 3fde13004563
Ref: ftplib — FTP protocol client-Footnote-113006411
Ref: ftplib — FTP protocol client-Footnote-213006477
Ref: ftplib — FTP protocol client-Footnote-313006535
Node: Reference<7>13006594
Ref: library/ftplib ftplib-reference13006673
Ref: 3fdf13006673
Ref: library/ftplib reference13006673
Ref: 3fe013006673
Node: FTP objects13006781
Ref: library/ftplib ftp-objects13006865
Ref: 3fe113006865
Ref: library/ftplib id113006865
Ref: 3fe213006865
Ref: library/ftplib ftplib FTP13006910
Ref: af813006910
Ref: library/ftplib ftplib FTP set_debuglevel13009810
Ref: 3fe413009810
Ref: library/ftplib ftplib FTP connect13010367
Ref: 3fe313010367
Ref: library/ftplib ftplib FTP getwelcome13011772
Ref: 3fe513011772
Ref: library/ftplib ftplib FTP login13012028
Ref: 3fe613012028
Ref: library/ftplib ftplib FTP abort13013066
Ref: 3fe713013066
Ref: library/ftplib ftplib FTP sendcmd13013215
Ref: 3fe813013215
Ref: library/ftplib ftplib FTP voidcmd13013461
Ref: 3fe913013461
Ref: library/ftplib ftplib FTP retrbinary13013867
Ref: 3feb13013867
Ref: library/ftplib ftplib FTP retrlines13014925
Ref: 3fed13014925
Ref: library/ftplib ftplib FTP set_pasv13015662
Ref: 3fee13015662
Ref: library/ftplib ftplib FTP storbinary13015822
Ref: 151113015822
Ref: library/ftplib ftplib FTP storlines13017000
Ref: 3fef13017000
Ref: library/ftplib ftplib FTP transfercmd13017498
Ref: 3fec13017498
Ref: library/ftplib ftplib FTP ntransfercmd13018742
Ref: 3ff013018742
Ref: library/ftplib ftplib FTP mlsd13019118
Ref: 12ca13019118
Ref: library/ftplib ftplib FTP nlst13019873
Ref: 12cb13019873
Ref: library/ftplib ftplib FTP dir13020315
Ref: 12cc13020315
Ref: library/ftplib ftplib FTP rename13021012
Ref: 3ff113021012
Ref: library/ftplib ftplib FTP delete13021117
Ref: 3ff213021117
Ref: library/ftplib ftplib FTP cwd13021401
Ref: 3ff413021401
Ref: library/ftplib ftplib FTP mkd13021486
Ref: 3ff513021486
Ref: library/ftplib ftplib FTP pwd13021568
Ref: 3ff613021568
Ref: library/ftplib ftplib FTP rmd13021664
Ref: 3ff713021664
Ref: library/ftplib ftplib FTP size13021759
Ref: 3ff813021759
Ref: library/ftplib ftplib FTP quit13022110
Ref: 3ff913022110
Ref: library/ftplib ftplib FTP close13022548
Ref: 3ffa13022548
Ref: FTP objects-Footnote-113023049
Ref: FTP objects-Footnote-213023107
Ref: FTP objects-Footnote-313023166
Ref: FTP objects-Footnote-413023224
Node: FTP_TLS objects13023283
Ref: library/ftplib ftp-tls-objects13023392
Ref: 3ffb13023392
Ref: library/ftplib ftplib FTP_TLS13023445
Ref: af913023445
Ref: library/ftplib ftplib FTP_TLS ssl_version13027134
Ref: 3ffd13027134
Ref: library/ftplib ftplib FTP_TLS auth13027259
Ref: 3ffe13027259
Ref: library/ftplib ftplib FTP_TLS ccc13027654
Ref: 12c913027654
Ref: library/ftplib ftplib FTP_TLS prot_p13027913
Ref: 3ffc13027913
Ref: library/ftplib ftplib FTP_TLS prot_c13027983
Ref: 3fff13027983
Ref: FTP_TLS objects-Footnote-113028093
Ref: FTP_TLS objects-Footnote-213028152
Ref: FTP_TLS objects-Footnote-313028210
Node: Module variables13028269
Ref: library/ftplib module-variables13028358
Ref: 400013028358
Ref: library/ftplib ftplib error_reply13028413
Ref: 3fea13028413
Ref: library/ftplib ftplib error_temp13028530
Ref: 400113028530
Ref: library/ftplib ftplib error_perm13028693
Ref: 3ff313028693
Ref: library/ftplib ftplib error_proto13028856
Ref: 400213028856
Ref: library/ftplib ftplib all_errors13029087
Ref: 400313029087
Node: poplib — POP3 protocol client13029672
Ref: library/poplib doc13029851
Ref: 400413029851
Ref: library/poplib module-poplib13029851
Ref: b113029851
Ref: library/poplib poplib-pop3-protocol-client13029851
Ref: 400513029851
Ref: library/poplib translation-repo13029851
Ref: 400613029851
Ref: library/poplib poplib POP313031126
Ref: b1f13031126
Ref: library/poplib poplib POP3_SSL13032049
Ref: b2013032049
Ref: library/poplib poplib error_proto13033617
Ref: 13a413033617
Ref: poplib — POP3 protocol client-Footnote-113034274
Ref: poplib — POP3 protocol client-Footnote-213034340
Ref: poplib — POP3 protocol client-Footnote-313034399
Ref: poplib — POP3 protocol client-Footnote-413034458
Ref: poplib — POP3 protocol client-Footnote-513034517
Node: POP3 Objects13034579
Ref: library/poplib id113034680
Ref: 400713034680
Ref: library/poplib pop3-objects13034680
Ref: 400813034680
Ref: library/poplib poplib POP3 set_debuglevel13034911
Ref: 400913034911
Ref: library/poplib poplib POP3 getwelcome13035376
Ref: 400a13035376
Ref: library/poplib poplib POP3 capa13035467
Ref: 117e13035467
Ref: library/poplib poplib POP3 user13035658
Ref: 400b13035658
Ref: library/poplib poplib POP3 pass_13035776
Ref: 400c13035776
Ref: library/poplib poplib POP3 apop13035971
Ref: 400d13035971
Ref: library/poplib poplib POP3 rpop13036089
Ref: 400e13036089
Ref: library/poplib poplib POP3 stat13036208
Ref: 400f13036208
Ref: library/poplib poplib POP3 list13036340
Ref: 401013036340
Ref: library/poplib poplib POP3 retr13036532
Ref: 401113036532
Ref: library/poplib poplib POP3 dele13036695
Ref: 401213036695
Ref: library/poplib poplib POP3 rset13036973
Ref: 401313036973
Ref: library/poplib poplib POP3 noop13037048
Ref: 401413037048
Ref: library/poplib poplib POP3 quit13037124
Ref: 13a313037124
Ref: library/poplib poplib POP3 top13037214
Ref: 401513037214
Ref: library/poplib poplib POP3 uidl13037751
Ref: 401613037751
Ref: library/poplib poplib POP3 utf813038035
Ref: 104b13038035
Ref: library/poplib poplib POP3 stls13038245
Ref: 117f13038245
Ref: POP3 Objects-Footnote-113039046
Ref: POP3 Objects-Footnote-213039105
Ref: POP3 Objects-Footnote-313039164
Node: POP3 Example13039223
Ref: library/poplib id213039324
Ref: 401713039324
Ref: library/poplib pop3-example13039324
Ref: 401813039324
Node: imaplib — IMAP4 protocol client13039836
Ref: library/imaplib doc13040017
Ref: 401913040017
Ref: library/imaplib imaplib-imap4-protocol-client13040017
Ref: 401a13040017
Ref: library/imaplib module-imaplib13040017
Ref: 7813040017
Ref: library/imaplib translation-repo13040017
Ref: 401b13040017
Ref: library/imaplib imaplib IMAP413040844
Ref: b0113040844
Ref: library/imaplib imaplib IMAP4 error13042070
Ref: 17df13042070
Ref: library/imaplib imaplib IMAP4 abort13042213
Ref: 401c13042213
Ref: library/imaplib imaplib IMAP4 readonly13042475
Ref: 401d13042475
Ref: library/imaplib imaplib IMAP4_SSL13042832
Ref: b0213042832
Ref: library/imaplib imaplib IMAP4_stream13044270
Ref: b0413044270
Ref: library/imaplib imaplib Internaldate2tuple13044541
Ref: 401e13044541
Ref: library/imaplib imaplib Int2AP13044791
Ref: 401f13044791
Ref: library/imaplib imaplib ParseFlags13044939
Ref: 402013044939
Ref: library/imaplib imaplib Time2Internaldate13045060
Ref: 402113045060
Ref: imaplib — IMAP4 protocol client-Footnote-113046407
Ref: imaplib — IMAP4 protocol client-Footnote-213046474
Ref: imaplib — IMAP4 protocol client-Footnote-313046533
Node: IMAP4 Objects13046592
Ref: library/imaplib id113046697
Ref: 402213046697
Ref: library/imaplib imap4-objects13046697
Ref: 402313046697
Ref: library/imaplib imaplib IMAP4 append13048199
Ref: 402413048199
Ref: library/imaplib imaplib IMAP4 authenticate13048303
Ref: 402513048303
Ref: library/imaplib imaplib IMAP4 check13049144
Ref: 402613049144
Ref: library/imaplib imaplib IMAP4 close13049208
Ref: b0613049208
Ref: library/imaplib imaplib IMAP4 copy13049393
Ref: 402713049393
Ref: library/imaplib imaplib IMAP4 create13049505
Ref: 402813049505
Ref: library/imaplib imaplib IMAP4 delete13049583
Ref: 402913049583
Ref: library/imaplib imaplib IMAP4 deleteacl13049661
Ref: 402a13049661
Ref: library/imaplib imaplib IMAP4 enable13049771
Ref: 101013049771
Ref: library/imaplib imaplib IMAP4 expunge13050091
Ref: 402b13050091
Ref: library/imaplib imaplib IMAP4 fetch13050339
Ref: 402c13050339
Ref: library/imaplib imaplib IMAP4 getacl13050619
Ref: 402d13050619
Ref: library/imaplib imaplib IMAP4 getannotation13050773
Ref: 402e13050773
Ref: library/imaplib imaplib IMAP4 getquota13050974
Ref: 402f13050974
Ref: library/imaplib imaplib IMAP4 getquotaroot13051148
Ref: 403013051148
Ref: library/imaplib imaplib IMAP4 idle13051336
Ref: 22d13051336
Ref: library/imaplib imaplib IMAP4 Idler burst13052901
Ref: 403213052901
Ref: library/imaplib imaplib IMAP4 list13055059
Ref: 403313055059
Ref: library/imaplib imaplib IMAP4 login13055328
Ref: 403413055328
Ref: library/imaplib imaplib IMAP4 login_cram_md513055461
Ref: 17de13055461
Ref: library/imaplib imaplib IMAP4 logout13055833
Ref: c8613055833
Ref: library/imaplib imaplib IMAP4 lsub13056035
Ref: 403513056035
Ref: library/imaplib imaplib IMAP4 myrights13056325
Ref: 403613056325
Ref: library/imaplib imaplib IMAP4 namespace13056444
Ref: 403713056444
Ref: library/imaplib imaplib IMAP4 noop13056533
Ref: 403813056533
Ref: library/imaplib imaplib IMAP4 open13056593
Ref: b0313056593
Ref: library/imaplib imaplib IMAP4 partial13057544
Ref: 403d13057544
Ref: library/imaplib imaplib IMAP4 proxyauth13057721
Ref: 403e13057721
Ref: library/imaplib imaplib IMAP4 read13057873
Ref: 403913057873
Ref: library/imaplib imaplib IMAP4 readline13057989
Ref: 403a13057989
Ref: library/imaplib imaplib IMAP4 recent13058101
Ref: 403f13058101
Ref: library/imaplib imaplib IMAP4 rename13058256
Ref: 404013058256
Ref: library/imaplib imaplib IMAP4 response13058364
Ref: 403113058364
Ref: library/imaplib imaplib IMAP4 search13058522
Ref: 404113058522
Ref: library/imaplib imaplib IMAP4 select13059198
Ref: 404213059198
Ref: library/imaplib imaplib IMAP4 send13059493
Ref: 403b13059493
Ref: library/imaplib imaplib IMAP4 setacl13059707
Ref: 404313059707
Ref: library/imaplib imaplib IMAP4 setannotation13059870
Ref: 404413059870
Ref: library/imaplib imaplib IMAP4 setquota13060059
Ref: 404513060059
Ref: library/imaplib imaplib IMAP4 shutdown13060233
Ref: 403c13060233
Ref: library/imaplib imaplib IMAP4 socket13060414
Ref: 404613060414
Ref: library/imaplib imaplib IMAP4 sort13060500
Ref: 404713060500
Ref: library/imaplib imaplib IMAP4 starttls13061444
Ref: 142d13061444
Ref: library/imaplib imaplib IMAP4 status13061978
Ref: 404813061978
Ref: library/imaplib imaplib IMAP4 store13062074
Ref: 404913062074
Ref: library/imaplib imaplib IMAP4 subscribe13063265
Ref: 404a13063265
Ref: library/imaplib imaplib IMAP4 thread13063336
Ref: 404b13063336
Ref: library/imaplib imaplib IMAP4 uid13064465
Ref: 404c13064465
Ref: library/imaplib imaplib IMAP4 unsubscribe13064783
Ref: 404d13064783
Ref: library/imaplib imaplib IMAP4 unselect13064860
Ref: b0513064860
Ref: library/imaplib imaplib IMAP4 xatom13065259
Ref: 404e13065259
Ref: library/imaplib imaplib IMAP4 PROTOCOL_VERSION13065463
Ref: 404f13065463
Ref: library/imaplib imaplib IMAP4 debug13065598
Ref: 405013065598
Ref: library/imaplib imaplib IMAP4 utf8_enabled13065801
Ref: 101113065801
Ref: IMAP4 Objects-Footnote-113066082
Ref: IMAP4 Objects-Footnote-213066141
Ref: IMAP4 Objects-Footnote-313066200
Ref: IMAP4 Objects-Footnote-413066259
Ref: IMAP4 Objects-Footnote-513066318
Ref: IMAP4 Objects-Footnote-613066377
Ref: IMAP4 Objects-Footnote-713066436
Node: IMAP4 Example13066495
Ref: library/imaplib id213066600
Ref: 405113066600
Ref: library/imaplib imap4-example13066600
Ref: 405213066600
Node: smtplib — SMTP protocol client13067106
Ref: library/smtplib doc13067299
Ref: 405313067299
Ref: library/smtplib module-smtplib13067299
Ref: cf13067299
Ref: library/smtplib smtplib-smtp-protocol-client13067299
Ref: 405413067299
Ref: library/smtplib translation-repo13067299
Ref: 405513067299
Ref: library/smtplib smtplib SMTP13067951
Ref: b2913067951
Ref: library/smtplib smtplib SMTP_SSL13070570
Ref: b2a13070570
Ref: library/smtplib smtplib LMTP13072084
Ref: b2b13072084
Ref: library/smtplib smtplib SMTPException13073023
Ref: 11a313073023
Ref: library/smtplib smtplib SMTPServerDisconnected13073284
Ref: 405813073284
Ref: library/smtplib smtplib SMTPResponseException13073512
Ref: 405913073512
Ref: library/smtplib smtplib SMTPResponseException smtp_code13073730
Ref: 405a13073730
Ref: library/smtplib smtplib SMTPResponseException smtp_error13073788
Ref: 405b13073788
Ref: library/smtplib smtplib SMTPSenderRefused13073850
Ref: 405c13073850
Ref: library/smtplib smtplib SMTPRecipientsRefused13074091
Ref: 405d13074091
Ref: library/smtplib smtplib SMTPRecipientsRefused recipients13074176
Ref: 405e13074176
Ref: library/smtplib smtplib SMTPDataError13074363
Ref: 405f13074363
Ref: library/smtplib smtplib SMTPConnectError13074459
Ref: 405613074459
Ref: library/smtplib smtplib SMTPHeloError13074580
Ref: 406013074580
Ref: library/smtplib smtplib SMTPNotSupportedError13074667
Ref: 1d9613074667
Ref: library/smtplib smtplib SMTPAuthenticationError13074811
Ref: 406113074811
Ref: smtplib — SMTP protocol client-Footnote-113075538
Ref: smtplib — SMTP protocol client-Footnote-213075605
Ref: smtplib — SMTP protocol client-Footnote-313075663
Ref: smtplib — SMTP protocol client-Footnote-413075722
Ref: smtplib — SMTP protocol client-Footnote-513075781
Ref: smtplib — SMTP protocol client-Footnote-613075839
Node: SMTP Objects13075898
Ref: library/smtplib id113076000
Ref: 406213076000
Ref: library/smtplib smtp-objects13076000
Ref: 406313076000
Ref: library/smtplib smtplib SMTP set_debuglevel13076104
Ref: 105a13076104
Ref: library/smtplib smtplib SMTP docmd13076460
Ref: 406413076460
Ref: library/smtplib smtplib SMTP connect13077110
Ref: 1d9713077110
Ref: library/smtplib smtplib SMTP helo13077796
Ref: 406513077796
Ref: library/smtplib smtplib SMTP ehlo13078264
Ref: 406713078264
Ref: library/smtplib smtplib SMTP ehlo_or_helo_if_needed13079191
Ref: 406c13079191
Ref: library/smtplib smtplib SMTP has_extn13079533
Ref: 406813079533
Ref: library/smtplib smtplib SMTP verify13079728
Ref: 406d13079728
Ref: library/smtplib smtplib SMTP login13080147
Ref: 406e13080147
Ref: library/smtplib smtplib SMTP auth13081738
Ref: 105913081738
Ref: library/smtplib smtplib SMTP starttls13083987
Ref: 134013083987
Ref: library/smtplib smtplib SMTP sendmail13085521
Ref: 105b13085521
Ref: library/smtplib smtplib SMTP send_message13088973
Ref: 105c13088973
Ref: library/smtplib smtplib SMTP quit13091055
Ref: 405713091055
Ref: library/smtplib smtplib SMTP helo_resp13091544
Ref: 406613091544
Ref: library/smtplib smtplib SMTP ehlo_resp13091645
Ref: 406913091645
Ref: library/smtplib smtplib SMTP does_esmtp13091746
Ref: 406a13091746
Ref: library/smtplib smtplib SMTP esmtp_features13091875
Ref: 406b13091875
Ref: SMTP Objects-Footnote-113092060
Ref: SMTP Objects-Footnote-213092118
Ref: SMTP Objects-Footnote-313092177
Ref: SMTP Objects-Footnote-413092236
Ref: SMTP Objects-Footnote-513092294
Ref: SMTP Objects-Footnote-613092352
Node: SMTP Example13092411
Ref: library/smtplib id213092513
Ref: 406f13092513
Ref: library/smtplib smtp-example13092513
Ref: 407013092513
Ref: SMTP Example-Footnote-113093943
Node: uuid — UUID objects according to RFC 956213094001
Ref: library/uuid doc13094209
Ref: 407113094209
Ref: library/uuid module-uuid13094209
Ref: 11613094209
Ref: library/uuid translation-repo13094209
Ref: 407213094209
Ref: library/uuid uuid-uuid-objects-according-to-rfc-956213094209
Ref: 407313094209
Ref: library/uuid uuid SafeUUID13095495
Ref: 407513095495
Ref: library/uuid uuid SafeUUID safe13095550
Ref: 407613095550
Ref: library/uuid uuid SafeUUID unsafe13095667
Ref: 407713095667
Ref: library/uuid uuid SafeUUID unknown13095764
Ref: 407813095764
Ref: library/uuid uuid UUID13095905
Ref: c5813095905
Ref: library/uuid uuid UUID bytes13097867
Ref: 407a13097867
Ref: library/uuid uuid UUID bytes_le13097996
Ref: 407b13097996
Ref: library/uuid uuid UUID fields13098148
Ref: 407c13098148
Ref: library/uuid uuid UUID time_low13098519
Ref: 407d13098519
Ref: library/uuid uuid UUID time_mid13098800
Ref: 407e13098800
Ref: library/uuid uuid UUID time_hi_version13099087
Ref: 407f13099087
Ref: library/uuid uuid UUID clock_seq_hi_variant13099372
Ref: 408013099372
Ref: library/uuid uuid UUID clock_seq_low13099651
Ref: 408113099651
Ref: library/uuid uuid UUID node13099928
Ref: 408213099928
Ref: library/uuid uuid UUID time13100208
Ref: 408313100208
Ref: library/uuid uuid UUID clock_seq13100820
Ref: 408413100820
Ref: library/uuid uuid UUID hex13101022
Ref: 187713101022
Ref: library/uuid uuid UUID int13101110
Ref: 407913101110
Ref: library/uuid uuid UUID urn13101172
Ref: 408513101172
Ref: library/uuid uuid UUID variant13101250
Ref: 408613101250
Ref: library/uuid uuid UUID version13101514
Ref: 408b13101514
Ref: library/uuid uuid UUID is_safe13101720
Ref: da113101720
Ref: library/uuid uuid getnode13101977
Ref: da213101977
Ref: library/uuid uuid-factory-functions13102955
Ref: 407413102955
Ref: library/uuid uuid uuid113102955
Ref: da313102955
Ref: library/uuid uuid uuid313103486
Ref: 2e513103486
Ref: library/uuid uuid uuid413103760
Ref: 2e713103760
Ref: library/uuid uuid uuid513103893
Ref: 2e613103893
Ref: library/uuid uuid uuid613104170
Ref: 2c213104170
Ref: library/uuid uuid uuid713104808
Ref: 2c313104808
Ref: library/uuid uuid uuid813105147
Ref: 2c413105147
Ref: library/uuid uuid NAMESPACE_DNS13105973
Ref: 408c13105973
Ref: library/uuid uuid NAMESPACE_URL13106100
Ref: 408d13106100
Ref: library/uuid uuid NAMESPACE_OID13106198
Ref: 408e13106198
Ref: library/uuid uuid NAMESPACE_X50013106301
Ref: 408f13106301
Ref: library/uuid uuid RESERVED_NCS13106566
Ref: 408713106566
Ref: library/uuid uuid RFC_412213106633
Ref: 408813106633
Ref: library/uuid uuid RESERVED_MICROSOFT13106835
Ref: 408913106835
Ref: library/uuid uuid RESERVED_FUTURE13106914
Ref: 408a13106914
Ref: library/uuid uuid NIL13107058
Ref: 2c513107058
Ref: library/uuid uuid MAX13107226
Ref: 2c613107226
Ref: uuid — UUID objects according to RFC 9562-Footnote-113107755
Ref: uuid — UUID objects according to RFC 9562-Footnote-213107819
Ref: uuid — UUID objects according to RFC 9562-Footnote-313107878
Ref: uuid — UUID objects according to RFC 9562-Footnote-413107937
Ref: uuid — UUID objects according to RFC 9562-Footnote-513107996
Ref: uuid — UUID objects according to RFC 9562-Footnote-613108055
Ref: uuid — UUID objects according to RFC 9562-Footnote-713108114
Ref: uuid — UUID objects according to RFC 9562-Footnote-813108185
Ref: uuid — UUID objects according to RFC 9562-Footnote-913108256
Ref: uuid — UUID objects according to RFC 9562-Footnote-1013108327
Ref: uuid — UUID objects according to RFC 9562-Footnote-1113108399
Ref: uuid — UUID objects according to RFC 9562-Footnote-1213108471
Ref: uuid — UUID objects according to RFC 9562-Footnote-1313108543
Ref: uuid — UUID objects according to RFC 9562-Footnote-1413108615
Ref: uuid — UUID objects according to RFC 9562-Footnote-1513108675
Ref: uuid — UUID objects according to RFC 9562-Footnote-1613108735
Ref: uuid — UUID objects according to RFC 9562-Footnote-1713108795
Ref: uuid — UUID objects according to RFC 9562-Footnote-1813108867
Ref: uuid — UUID objects according to RFC 9562-Footnote-1913108940
Node: Command-Line Usage13109000
Ref: library/uuid command-line-usage13109118
Ref: 409013109118
Ref: library/uuid uuid-cli13109118
Ref: 67613109118
Ref: library/uuid cmdoption-uuid-h13109418
Ref: 409113109418
Ref: library/uuid cmdoption-uuid-help13109418
Ref: 409213109418
Ref: library/uuid cmdoption-uuid-u13109480
Ref: 409313109480
Ref: library/uuid cmdoption-uuid-uuid13109502
Ref: 409413109502
Ref: library/uuid cmdoption-uuid-n13109720
Ref: 409513109720
Ref: library/uuid cmdoption-uuid-namespace13109747
Ref: 409613109747
Ref: library/uuid cmdoption-uuid-N13110059
Ref: 409713110059
Ref: library/uuid cmdoption-uuid-name13110081
Ref: 409813110081
Ref: library/uuid cmdoption-uuid-C13110237
Ref: 409913110237
Ref: library/uuid cmdoption-uuid-count13110258
Ref: 2c713110258
Node: Example<11>13110348
Ref: library/uuid example13110495
Ref: 409a13110495
Ref: library/uuid uuid-example13110495
Ref: 409b13110495
Node: Command-Line Example13112557
Ref: library/uuid command-line-example13112677
Ref: 409c13112677
Ref: library/uuid uuid-cli-example13112677
Ref: 409d13112677
Node: socketserver — A framework for network servers13113131
Ref: library/socketserver doc13113335
Ref: 409e13113335
Ref: library/socketserver module-socketserver13113335
Ref: d213113335
Ref: library/socketserver socketserver-a-framework-for-network-servers13113335
Ref: 409f13113335
Ref: library/socketserver translation-repo13113335
Ref: 40a013113335
Ref: library/socketserver socketserver TCPServer13113857
Ref: 152713113857
Ref: library/socketserver socketserver UDPServer13114330
Ref: 40a313114330
Ref: library/socketserver socketserver UnixStreamServer13114634
Ref: 40a413114634
Ref: library/socketserver socketserver UnixDatagramServer13114748
Ref: 40a513114748
Ref: socketserver — A framework for network servers-Footnote-113117102
Node: Server Creation Notes13117174
Ref: library/socketserver server-creation-notes13117306
Ref: 40a813117306
Ref: library/socketserver socketserver ForkingMixIn13118079
Ref: d7313118079
Ref: library/socketserver socketserver ThreadingMixIn13118117
Ref: d3c13118117
Ref: library/socketserver socketserver ThreadingMixIn block_on_close13118777
Ref: d7213118777
Ref: library/socketserver socketserver ThreadingMixIn max_children13119166
Ref: 40aa13119166
Ref: library/socketserver socketserver ThreadingMixIn daemon_threads13119430
Ref: 40ab13119430
Ref: library/socketserver socketserver ForkingTCPServer13119965
Ref: 40ac13119965
Ref: library/socketserver socketserver ForkingUDPServer13120007
Ref: 40ad13120007
Ref: library/socketserver socketserver ThreadingTCPServer13120049
Ref: 40ae13120049
Ref: library/socketserver socketserver ThreadingUDPServer13120093
Ref: 40a913120093
Ref: library/socketserver socketserver ForkingUnixStreamServer13120137
Ref: 40af13120137
Ref: library/socketserver socketserver ForkingUnixDatagramServer13120186
Ref: 40b013120186
Ref: library/socketserver socketserver ThreadingUnixStreamServer13120237
Ref: 40b113120237
Ref: library/socketserver socketserver ThreadingUnixDatagramServer13120288
Ref: 40b213120288
Node: Server Objects<2>13122645
Ref: library/socketserver server-objects13122809
Ref: 40b413122809
Ref: library/socketserver socketserver BaseServer13122860
Ref: 134513122860
Ref: library/socketserver socketserver BaseServer fileno13123270
Ref: 40b713123270
Ref: library/socketserver socketserver BaseServer handle_request13123543
Ref: 152a13123543
Ref: library/socketserver socketserver BaseServer serve_forever13124145
Ref: 134713124145
Ref: library/socketserver socketserver BaseServer service_actions13124803
Ref: 134613124803
Ref: library/socketserver socketserver BaseServer shutdown13125106
Ref: 1dfe13125106
Ref: library/socketserver socketserver BaseServer server_close13125388
Ref: d7113125388
Ref: library/socketserver socketserver BaseServer address_family13125474
Ref: 40bb13125474
Ref: library/socketserver socketserver BaseServer RequestHandlerClass13125888
Ref: 40b613125888
Ref: library/socketserver socketserver BaseServer server_address13126046
Ref: 40b513126046
Ref: library/socketserver socketserver BaseServer socket13126469
Ref: 40bc13126469
Ref: library/socketserver socketserver BaseServer allow_reuse_address13126655
Ref: 40bd13126655
Ref: library/socketserver socketserver BaseServer request_queue_size13126869
Ref: 40be13126869
Ref: library/socketserver socketserver BaseServer socket_type13127358
Ref: 40bf13127358
Ref: library/socketserver socketserver BaseServer timeout13127551
Ref: 152813127551
Ref: library/socketserver socketserver BaseServer finish_request13128057
Ref: 40c013128057
Ref: library/socketserver socketserver BaseServer get_request13128274
Ref: 40b813128274
Ref: library/socketserver socketserver BaseServer handle_error13128504
Ref: f3f13128504
Ref: library/socketserver socketserver BaseServer handle_timeout13128961
Ref: 152913128961
Ref: library/socketserver socketserver BaseServer process_request13129400
Ref: 40ba13129400
Ref: library/socketserver socketserver BaseServer server_activate13129771
Ref: 40a213129771
Ref: library/socketserver socketserver BaseServer server_bind13130019
Ref: 40a113130019
Ref: library/socketserver socketserver BaseServer verify_request13130173
Ref: 40b913130173
Node: Request Handler Objects13130762
Ref: library/socketserver request-handler-objects13130917
Ref: 40c113130917
Ref: library/socketserver socketserver BaseRequestHandler13130986
Ref: 40a613130986
Ref: library/socketserver socketserver BaseRequestHandler setup13131341
Ref: 40c213131341
Ref: library/socketserver socketserver BaseRequestHandler handle13131536
Ref: 40a713131536
Ref: library/socketserver socketserver BaseRequestHandler finish13132251
Ref: 40c613132251
Ref: library/socketserver socketserver BaseRequestHandler request13132530
Ref: 40c313132530
Ref: library/socketserver socketserver BaseRequestHandler client_address13132666
Ref: 40c413132666
Ref: library/socketserver socketserver BaseRequestHandler server13132788
Ref: 40c513132788
Ref: library/socketserver socketserver StreamRequestHandler13132889
Ref: ed813132889
Ref: library/socketserver socketserver DatagramRequestHandler13132935
Ref: 40b313132935
Ref: library/socketserver socketserver DatagramRequestHandler rfile13133183
Ref: 40c713133183
Ref: library/socketserver socketserver DatagramRequestHandler wfile13133348
Ref: ed713133348
Node: Examples<29>13133629
Ref: library/socketserver examples13133758
Ref: 40c813133758
Node: socketserver TCPServer Example13133963
Ref: library/socketserver socketserver-tcpserver-example13134081
Ref: 40c913134081
Node: socketserver UDPServer Example13137918
Ref: library/socketserver socketserver-udpserver-example13138064
Ref: 40ca13138064
Node: Asynchronous Mixins13139653
Ref: library/socketserver asynchronous-mixins13139760
Ref: 40cb13139760
Node: http server — HTTP servers13142106
Ref: library/http server doc13142305
Ref: 40cc13142305
Ref: library/http server http-server-http-servers13142305
Ref: 40cd13142305
Ref: library/http server module-http server13142305
Ref: 7613142305
Ref: library/http server translation-repo13142305
Ref: 40ce13142305
Ref: library/http server http server HTTPServer13143282
Ref: 3ecc13143282
Ref: library/http server http server ThreadingHTTPServer13143638
Ref: d3b13143638
Ref: library/http server http server HTTPSServer13144012
Ref: 22813144012
Ref: library/http server http server ThreadingHTTPSServer13145368
Ref: 40d013145368
Ref: library/http server http server BaseHTTPRequestHandler13146065
Ref: 12d313146065
Ref: library/http server http server BaseHTTPRequestHandler client_address13147052
Ref: 40d113147052
Ref: library/http server http server BaseHTTPRequestHandler server13147194
Ref: 40d213147194
Ref: library/http server http server BaseHTTPRequestHandler close_connection13147263
Ref: 40d313147263
Ref: library/http server http server BaseHTTPRequestHandler requestline13147498
Ref: 40d513147498
Ref: library/http server http server BaseHTTPRequestHandler command13147813
Ref: 40d613147813
Ref: library/http server http server BaseHTTPRequestHandler path13147917
Ref: 40d713147917
Ref: library/http server http server BaseHTTPRequestHandler request_version13148191
Ref: 40d813148191
Ref: library/http server http server BaseHTTPRequestHandler headers13148327
Ref: 3fb113148327
Ref: library/http server http server BaseHTTPRequestHandler rfile13148754
Ref: 40da13148754
Ref: library/http server http server BaseHTTPRequestHandler wfile13148906
Ref: 40db13148906
Ref: library/http server http server BaseHTTPRequestHandler server_version13149360
Ref: 40dc13149360
Ref: library/http server http server BaseHTTPRequestHandler sys_version13149647
Ref: 40dd13149647
Ref: library/http server http server BaseHTTPRequestHandler error_message_format13149902
Ref: 115213149902
Ref: library/http server http server BaseHTTPRequestHandler error_content_type13150265
Ref: 40df13150265
Ref: library/http server http server BaseHTTPRequestHandler protocol_version13150445
Ref: 40e013150445
Ref: library/http server http server BaseHTTPRequestHandler MessageClass13151041
Ref: 40d913151041
Ref: library/http server http server BaseHTTPRequestHandler responses13151279
Ref: 3f9613151279
Ref: library/http server http server BaseHTTPRequestHandler handle13151846
Ref: 40e313151846
Ref: library/http server http server BaseHTTPRequestHandler handle_one_request13152146
Ref: 40d413152146
Ref: library/http server http server BaseHTTPRequestHandler handle_expect_10013152344
Ref: 40e413152344
Ref: library/http server http server BaseHTTPRequestHandler send_error13152855
Ref: 115113152855
Ref: library/http server http server BaseHTTPRequestHandler send_response13153988
Ref: 40e513153988
Ref: library/http server http server BaseHTTPRequestHandler send_header13154811
Ref: 40e113154811
Ref: library/http server http server BaseHTTPRequestHandler send_response_only13155399
Ref: 40e213155399
Ref: library/http server http server BaseHTTPRequestHandler end_headers13155821
Ref: 12d413155821
Ref: library/http server http server BaseHTTPRequestHandler flush_headers13156126
Ref: 12d513156126
Ref: library/http server http server BaseHTTPRequestHandler log_request13156300
Ref: 40e713156300
Ref: library/http server http server BaseHTTPRequestHandler log_error13156597
Ref: 40e813156597
Ref: library/http server http server BaseHTTPRequestHandler log_message13156842
Ref: 40e913156842
Ref: library/http server http server BaseHTTPRequestHandler version_string13157331
Ref: 40de13157331
Ref: library/http server http server BaseHTTPRequestHandler date_time_string13157545
Ref: 40e613157545
Ref: library/http server http server BaseHTTPRequestHandler log_date_time_string13157933
Ref: 40ea13157933
Ref: library/http server http server BaseHTTPRequestHandler address_string13158044
Ref: 40eb13158044
Ref: library/http server http server SimpleHTTPRequestHandler13158292
Ref: d3a13158292
Ref: library/http server http server SimpleHTTPRequestHandler server_version13159090
Ref: 40ee13159090
Ref: library/http server http server SimpleHTTPRequestHandler extensions_map13159251
Ref: 40ef13159251
Ref: library/http server http server SimpleHTTPRequestHandler do_HEAD13159768
Ref: 40ed13159768
Ref: library/http server http server SimpleHTTPRequestHandler do_GET13160056
Ref: 40ec13160056
Ref: library/http server http server CGIHTTPRequestHandler13162502
Ref: 32513162502
Ref: library/http server http server CGIHTTPRequestHandler cgi_directories13163692
Ref: 40f013163692
Ref: library/http server http server CGIHTTPRequestHandler do_POST13163932
Ref: 40f113163932
Ref: http server — HTTP servers-Footnote-113164870
Ref: http server — HTTP servers-Footnote-213164941
Ref: http server — HTTP servers-Footnote-313165000
Ref: http server — HTTP servers-Footnote-413165059
Node: Command-line interface<7>13165130
Ref: library/http server command-line-interface13165255
Ref: 40f213165255
Ref: library/http server http-server-cli13165255
Ref: 115313165255
Ref: library/http server cmdoption-http server-arg-port13165598
Ref: 40f313165598
Ref: library/http server cmdoption-http server-b13165791
Ref: 40f413165791
Ref: library/http server cmdoption-http server-bind13165791
Ref: 40f513165791
Ref: library/http server cmdoption-http server-d13166236
Ref: 182713166236
Ref: library/http server cmdoption-http server-directory13166236
Ref: 40f613166236
Ref: library/http server cmdoption-http server-p13166539
Ref: 40f713166539
Ref: library/http server cmdoption-http server-protocol13166539
Ref: 40f813166539
Ref: library/http server cmdoption-http server-cgi13166860
Ref: 40f913166860
Ref: library/http server cmdoption-http server-tls-cert13167481
Ref: 22913167481
Ref: library/http server cmdoption-http server-tls-key13167655
Ref: 22a13167655
Ref: library/http server cmdoption-http server-tls-password-file13167826
Ref: 22b13167826
Node: Security considerations<3>13168183
Ref: library/http server http-server-security13168308
Ref: 40cf13168308
Ref: library/http server security-considerations13168308
Ref: 40fa13168308
Node: http cookies — HTTP state management13168956
Ref: library/http cookies doc13169158
Ref: 40fb13169158
Ref: library/http cookies http-cookies-http-state-management13169158
Ref: 40fc13169158
Ref: library/http cookies module-http cookies13169158
Ref: 7513169158
Ref: library/http cookies translation-repo13169158
Ref: 40fd13169158
Ref: library/http cookies http cookies CookieError13170564
Ref: 40fe13170564
Ref: library/http cookies http cookies BaseCookie13170731
Ref: 40ff13170731
Ref: library/http cookies http cookies SimpleCookie13171121
Ref: 1e0c13171121
Ref: http cookies — HTTP state management-Footnote-113171985
Ref: http cookies — HTTP state management-Footnote-213172057
Ref: http cookies — HTTP state management-Footnote-313172116
Ref: http cookies — HTTP state management-Footnote-413172175
Ref: http cookies — HTTP state management-Footnote-513172234
Node: Cookie Objects13172293
Ref: library/http cookies cookie-objects13172405
Ref: 410313172405
Ref: library/http cookies id113172405
Ref: 410413172405
Ref: library/http cookies http cookies BaseCookie value_decode13172456
Ref: 410113172456
Ref: library/http cookies http cookies BaseCookie value_encode13172728
Ref: 410213172728
Ref: library/http cookies http cookies BaseCookie output13173180
Ref: 410513173180
Ref: library/http cookies http cookies BaseCookie js_output13173548
Ref: 410713173548
Ref: library/http cookies http cookies BaseCookie load13173827
Ref: 410013173827
Node: Morsel Objects13174109
Ref: library/http cookies id213174241
Ref: 410813174241
Ref: library/http cookies morsel-objects13174241
Ref: 410913174241
Ref: library/http cookies http cookies Morsel13174292
Ref: e0013174292
Ref: library/http cookies http cookies Morsel expires13174524
Ref: 410a13174524
Ref: library/http cookies http cookies Morsel path13174557
Ref: 410b13174557
Ref: library/http cookies http cookies Morsel comment13174587
Ref: 410c13174587
Ref: library/http cookies http cookies Morsel domain13174620
Ref: 410d13174620
Ref: library/http cookies http cookies Morsel secure13174686
Ref: 410e13174686
Ref: library/http cookies http cookies Morsel version13174718
Ref: 410f13174718
Ref: library/http cookies http cookies Morsel httponly13174751
Ref: 15d713174751
Ref: library/http cookies http cookies Morsel samesite13174785
Ref: 411013174785
Ref: library/http cookies http cookies Morsel partitioned13174819
Ref: 411113174819
Ref: library/http cookies http cookies Morsel value13176672
Ref: dfe13176672
Ref: library/http cookies http cookies Morsel coded_value13176732
Ref: dff13176732
Ref: library/http cookies http cookies Morsel key13176838
Ref: dfd13176838
Ref: library/http cookies http cookies Morsel set13176895
Ref: e0113176895
Ref: library/http cookies http cookies Morsel isReservedKey13177004
Ref: 411213177004
Ref: library/http cookies http cookies Morsel output13177115
Ref: 410613177115
Ref: library/http cookies http cookies Morsel js_output13177455
Ref: 411313177455
Ref: library/http cookies http cookies Morsel OutputString13177729
Ref: 411413177729
Ref: library/http cookies http cookies Morsel update13177941
Ref: 10cb13177941
Ref: library/http cookies http cookies Morsel copy13178246
Ref: 10ca13178246
Ref: library/http cookies http cookies Morsel setdefault13178411
Ref: 411513178411
Ref: Morsel Objects-Footnote-113178627
Ref: Morsel Objects-Footnote-213178686
Ref: Morsel Objects-Footnote-313178745
Ref: Morsel Objects-Footnote-413178808
Ref: Morsel Objects-Footnote-513178867
Node: Example<12>13178926
Ref: library/http cookies cookie-example13179035
Ref: 411613179035
Ref: library/http cookies example13179035
Ref: 411713179035
Node: http cookiejar — Cookie handling for HTTP clients13180678
Ref: library/http cookiejar doc13180895
Ref: 411813180895
Ref: library/http cookiejar http-cookiejar-cookie-handling-for-http-clients13180895
Ref: 411913180895
Ref: library/http cookiejar module-http cookiejar13180895
Ref: 7413180895
Ref: library/http cookiejar translation-repo13180895
Ref: 411a13180895
Ref: library/http cookiejar http cookiejar LoadError13182462
Ref: 411b13182462
Ref: library/http cookiejar http cookiejar CookieJar13182876
Ref: 3f3a13182876
Ref: library/http cookiejar http cookiejar FileCookieJar13183353
Ref: 411c13183353
Ref: library/http cookiejar http cookiejar CookiePolicy13184197
Ref: 411d13184197
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy13184358
Ref: 1ddc13184358
Ref: library/http cookiejar http cookiejar Cookie13186183
Ref: 412213186183
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-113187884
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-213187958
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-313188017
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-413188076
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-513188135
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-613188194
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-713188253
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-813188312
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-913188371
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-1013188430
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-1113188490
Ref: http cookiejar — Cookie handling for HTTP clients-Footnote-1213188550
Node: CookieJar and FileCookieJar Objects13188610
Ref: library/http cookiejar cookie-jar-objects13188801
Ref: 412313188801
Ref: library/http cookiejar cookiejar-and-filecookiejar-objects13188801
Ref: 412413188801
Ref: library/http cookiejar http cookiejar CookieJar add_cookie_header13189077
Ref: 412513189077
Ref: library/http cookiejar http cookiejar CookieJar extract_cookies13190000
Ref: 412613190000
Ref: library/http cookiejar http cookiejar CookieJar set_policy13191239
Ref: 412813191239
Ref: library/http cookiejar http cookiejar CookieJar make_cookies13191343
Ref: 412913191343
Ref: library/http cookiejar http cookiejar CookieJar set_cookie_if_ok13191630
Ref: 412a13191630
Ref: library/http cookiejar http cookiejar CookieJar set_cookie13191755
Ref: 412b13191755
Ref: library/http cookiejar http cookiejar CookieJar clear13191904
Ref: 412c13191904
Ref: library/http cookiejar http cookiejar CookieJar clear_session_cookies13192409
Ref: 412d13192409
Ref: library/http cookiejar http cookiejar FileCookieJar save13193052
Ref: 412e13193052
Ref: library/http cookiejar http cookiejar FileCookieJar load13193905
Ref: 411e13193905
Ref: library/http cookiejar http cookiejar FileCookieJar revert13194478
Ref: 411f13194478
Ref: library/http cookiejar http cookiejar FileCookieJar filename13194877
Ref: 412f13194877
Ref: library/http cookiejar http cookiejar FileCookieJar delayload13195014
Ref: 413013195014
Node: FileCookieJar subclasses and co-operation with web browsers13195435
Ref: library/http cookiejar file-cookie-jar-classes13195655
Ref: 412013195655
Ref: library/http cookiejar filecookiejar-subclasses-and-co-operation-with-web-browsers13195655
Ref: 413113195655
Ref: library/http cookiejar http cookiejar MozillaCookieJar13195883
Ref: 413213195883
Ref: library/http cookiejar http cookiejar LWPCookieJar13196700
Ref: 413313196700
Ref: FileCookieJar subclasses and co-operation with web browsers-Footnote-113197189
Node: CookiePolicy Objects13197248
Ref: library/http cookiejar cookie-policy-objects13197460
Ref: 413413197460
Ref: library/http cookiejar cookiepolicy-objects13197460
Ref: 413513197460
Ref: library/http cookiejar http cookiejar CookiePolicy set_ok13197613
Ref: 412713197613
Ref: library/http cookiejar http cookiejar CookiePolicy return_ok13197939
Ref: 413613197939
Ref: library/http cookiejar http cookiejar CookiePolicy domain_return_ok13198268
Ref: 413713198268
Ref: library/http cookiejar http cookiejar CookiePolicy path_return_ok13199646
Ref: 413813199646
Ref: library/http cookiejar http cookiejar CookiePolicy netscape13200098
Ref: 413913200098
Ref: library/http cookiejar http cookiejar CookiePolicy rfc296513200171
Ref: 413a13200171
Ref: library/http cookiejar http cookiejar CookiePolicy hide_cookie213200246
Ref: 413b13200246
Ref: CookiePolicy Objects-Footnote-113200797
Ref: CookiePolicy Objects-Footnote-213200856
Node: DefaultCookiePolicy Objects13200915
Ref: library/http cookiejar default-cookie-policy-objects13201085
Ref: 413c13201085
Ref: library/http cookiejar defaultcookiepolicy-objects13201085
Ref: 413d13201085
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy blocked_domains13203404
Ref: 413e13203404
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy set_blocked_domains13203515
Ref: 413f13203515
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy is_blocked13203629
Ref: 414013203629
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy allowed_domains13203777
Ref: 414113203777
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy set_allowed_domains13203913
Ref: 414213203913
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy is_not_allowed13204047
Ref: 414313204047
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy rfc2109_as_netscape13204387
Ref: 412113204387
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_domain13204974
Ref: 414413204974
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_rfc2965_unverifiable13205278
Ref: 414513205278
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_ns_unverifiable13205656
Ref: 414613205656
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_ns_domain13205805
Ref: 414713205805
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_ns_set_initial_dollar13205986
Ref: 414813205986
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy strict_ns_set_path13206141
Ref: 414913206141
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy DomainStrictNoDots13206472
Ref: 414a13206472
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy DomainStrictNonDomain13206717
Ref: 414b13206717
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy DomainRFC2965Match13207065
Ref: 414c13207065
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy DomainLiberal13207302
Ref: 414d13207302
Ref: library/http cookiejar http cookiejar DefaultCookiePolicy DomainStrict13207450
Ref: 414e13207450
Ref: DefaultCookiePolicy Objects-Footnote-113207603
Ref: DefaultCookiePolicy Objects-Footnote-213207662
Ref: DefaultCookiePolicy Objects-Footnote-313207721
Ref: DefaultCookiePolicy Objects-Footnote-413207780
Ref: DefaultCookiePolicy Objects-Footnote-513207839
Ref: DefaultCookiePolicy Objects-Footnote-613207898
Ref: DefaultCookiePolicy Objects-Footnote-713207957
Node: Cookie Objects<2>13208016
Ref: library/http cookiejar cookie-objects13208178
Ref: 414f13208178
Ref: library/http cookiejar http cookiejar Cookie version13208947
Ref: 415013208947
Ref: library/http cookiejar http cookiejar Cookie name13209305
Ref: 415113209305
Ref: library/http cookiejar http cookiejar Cookie value13209363
Ref: 415213209363
Ref: library/http cookiejar http cookiejar Cookie port13209443
Ref: 415313209443
Ref: library/http cookiejar http cookiejar Cookie domain13209582
Ref: 415413209582
Ref: library/http cookiejar http cookiejar Cookie path13209644
Ref: 415513209644
Ref: library/http cookiejar http cookiejar Cookie secure13209739
Ref: 415613209739
Ref: library/http cookiejar http cookiejar Cookie expires13209846
Ref: 415713209846
Ref: library/http cookiejar http cookiejar Cookie discard13209999
Ref: 415913209999
Ref: library/http cookiejar http cookiejar Cookie comment13210076
Ref: 415a13210076
Ref: library/http cookiejar http cookiejar Cookie comment_url13210209
Ref: 415b13210209
Ref: library/http cookiejar http cookiejar Cookie rfc210913210356
Ref: 415c13210356
Ref: library/http cookiejar http cookiejar Cookie port_specified13210766
Ref: 415d13210766
Ref: library/http cookiejar http cookiejar Cookie domain_specified13210945
Ref: 415e13210945
Ref: library/http cookiejar http cookiejar Cookie domain_initial_dot13211054
Ref: 415f13211054
Ref: library/http cookiejar http cookiejar Cookie has_nonstandard_attr13211310
Ref: 416013211310
Ref: library/http cookiejar http cookiejar Cookie get_nonstandard_attr13211424
Ref: 416113211424
Ref: library/http cookiejar http cookiejar Cookie set_nonstandard_attr13211586
Ref: 416213211586
Ref: library/http cookiejar http cookiejar Cookie is_expired13211758
Ref: 415813211758
Ref: Cookie Objects<2>-Footnote-113212051
Ref: Cookie Objects<2>-Footnote-213212110
Ref: Cookie Objects<2>-Footnote-313212169
Ref: Cookie Objects<2>-Footnote-413212228
Node: Examples<30>13212287
Ref: library/http cookiejar examples13212413
Ref: 416313212413
Ref: Examples<30>-Footnote-113213866
Node: xmlrpc — XMLRPC server and client modules13213925
Ref: library/xmlrpc doc13214143
Ref: 416413214143
Ref: library/xmlrpc module-xmlrpc13214143
Ref: 13313214143
Ref: library/xmlrpc translation-repo13214143
Ref: 416513214143
Ref: library/xmlrpc xmlrpc-xmlrpc-server-and-client-modules13214143
Ref: 416613214143
Node: xmlrpc client — XML-RPC client access13214645
Ref: library/xmlrpc client doc13214851
Ref: 416713214851
Ref: library/xmlrpc client module-xmlrpc client13214851
Ref: 13413214851
Ref: library/xmlrpc client translation-repo13214851
Ref: 416813214851
Ref: library/xmlrpc client xmlrpc-client-xml-rpc-client-access13214851
Ref: 416913214851
Ref: library/xmlrpc client xmlrpc client ServerProxy13215951
Ref: c4e13215951
Ref: xmlrpc client — XML-RPC client access-Footnote-113223982
Ref: xmlrpc client — XML-RPC client access-Footnote-213224055
Ref: xmlrpc client — XML-RPC client access-Footnote-313224149
Ref: xmlrpc client — XML-RPC client access-Footnote-413224205
Ref: xmlrpc client — XML-RPC client access-Footnote-513224264
Node: ServerProxy Objects13224310
Ref: library/xmlrpc client id113224430
Ref: 416d13224430
Ref: library/xmlrpc client serverproxy-objects13224430
Ref: 416e13224430
Ref: library/xmlrpc client xmlrpc client ServerProxy system listMethods13225086
Ref: 416f13225086
Ref: library/xmlrpc client xmlrpc client ServerProxy system methodSignature13225249
Ref: 417013225249
Ref: library/xmlrpc client xmlrpc client ServerProxy system methodHelp13226269
Ref: 417113226269
Node: DateTime Objects13227349
Ref: library/xmlrpc client datetime-objects13227492
Ref: 417213227492
Ref: library/xmlrpc client id213227492
Ref: 417313227492
Ref: library/xmlrpc client xmlrpc client DateTime13227547
Ref: 15ea13227547
Ref: library/xmlrpc client xmlrpc client DateTime decode13227857
Ref: 417413227857
Ref: library/xmlrpc client xmlrpc client DateTime encode13227954
Ref: 417513227954
Node: Binary Objects13229039
Ref: library/xmlrpc client binary-objects13229176
Ref: 417613229176
Ref: library/xmlrpc client id313229176
Ref: 417713229176
Ref: library/xmlrpc client xmlrpc client Binary13229227
Ref: 416a13229227
Ref: library/xmlrpc client xmlrpc client Binary data13229445
Ref: 417813229445
Ref: library/xmlrpc client xmlrpc client Binary decode13229751
Ref: 417913229751
Ref: library/xmlrpc client xmlrpc client Binary encode13229890
Ref: 417a13229890
Ref: Binary Objects-Footnote-113231134
Node: Fault Objects13231205
Ref: library/xmlrpc client fault-objects13231347
Ref: 417b13231347
Ref: library/xmlrpc client id413231347
Ref: 417c13231347
Ref: library/xmlrpc client xmlrpc client Fault13231396
Ref: 416b13231396
Ref: library/xmlrpc client xmlrpc client Fault faultCode13231564
Ref: 417d13231564
Ref: library/xmlrpc client xmlrpc client Fault faultString13231640
Ref: 417e13231640
Node: ProtocolError Objects13232602
Ref: library/xmlrpc client protocol-error-objects13232747
Ref: 417f13232747
Ref: library/xmlrpc client protocolerror-objects13232747
Ref: 418013232747
Ref: library/xmlrpc client xmlrpc client ProtocolError13232812
Ref: 416c13232812
Ref: library/xmlrpc client xmlrpc client ProtocolError url13233090
Ref: 418113233090
Ref: library/xmlrpc client xmlrpc client ProtocolError errcode13233167
Ref: 418213233167
Ref: library/xmlrpc client xmlrpc client ProtocolError errmsg13233223
Ref: 418313233223
Ref: library/xmlrpc client xmlrpc client ProtocolError headers13233302
Ref: 418413233302
Node: MultiCall Objects13234042
Ref: library/xmlrpc client multicall-objects13234195
Ref: 418513234195
Ref: library/xmlrpc client xmlrpc client MultiCall13234378
Ref: 418613234378
Ref: MultiCall Objects-Footnote-113236085
Node: Convenience Functions13236264
Ref: library/xmlrpc client convenience-functions13236419
Ref: 418713236419
Ref: library/xmlrpc client xmlrpc client dumps13236484
Ref: 418813236484
Ref: library/xmlrpc client xmlrpc client loads13237196
Ref: 163c13237196
Node: Example of Client Usage13238074
Ref: library/xmlrpc client example-of-client-usage13238246
Ref: 418913238246
Ref: library/xmlrpc client xmlrpc-client-example13238246
Ref: 418a13238246
Node: Example of Client and Server Usage13239553
Ref: library/xmlrpc client example-of-client-and-server-usage13239695
Ref: 418b13239695
Node: xmlrpc server — Basic XML-RPC servers13239831
Ref: library/xmlrpc server doc13240038
Ref: 418d13240038
Ref: library/xmlrpc server module-xmlrpc server13240038
Ref: 13513240038
Ref: library/xmlrpc server translation-repo13240038
Ref: 418e13240038
Ref: library/xmlrpc server xmlrpc-server-basic-xml-rpc-servers13240038
Ref: 418f13240038
Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCServer13240882
Ref: 419013240882
Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler13242417
Ref: 419113242417
Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCRequestHandler13243079
Ref: 152f13243079
Ref: xmlrpc server — Basic XML-RPC servers-Footnote-113243568
Node: SimpleXMLRPCServer Objects13243641
Ref: library/xmlrpc server simple-xmlrpc-servers13243775
Ref: 419213243775
Ref: library/xmlrpc server simplexmlrpcserver-objects13243775
Ref: 419313243775
Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCServer register_function13244011
Ref: 419413244011
Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCServer register_instance13244772
Ref: 419513244772
Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCServer register_introspection_functions13246393
Ref: 419613246393
Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCServer register_multicall_functions13246602
Ref: 419713246602
Ref: library/xmlrpc server xmlrpc server SimpleXMLRPCRequestHandler rpc_paths13246731
Ref: 419813246731
Node: SimpleXMLRPCServer Example13247149
Ref: library/xmlrpc server id113247238
Ref: 419913247238
Ref: library/xmlrpc server simplexmlrpcserver-example13247238
Ref: 418c13247238
Node: CGIXMLRPCRequestHandler13251760
Ref: library/xmlrpc server cgixmlrpcrequesthandler13251928
Ref: 419a13251928
Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler register_function13252112
Ref: 419b13252112
Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler register_instance13252878
Ref: 419c13252878
Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler register_introspection_functions13253763
Ref: 419d13253763
Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler register_multicall_functions13253976
Ref: 419e13253976
Ref: library/xmlrpc server xmlrpc server CGIXMLRPCRequestHandler handle_request13254115
Ref: 419f13254115
Node: Documenting XMLRPC server13254702
Ref: library/xmlrpc server documenting-xmlrpc-server13254867
Ref: 41a013254867
Ref: library/xmlrpc server xmlrpc server DocXMLRPCServer13255195
Ref: 1d8e13255195
Ref: library/xmlrpc server xmlrpc server DocCGIXMLRPCRequestHandler13255684
Ref: 41a113255684
Ref: library/xmlrpc server xmlrpc server DocXMLRPCRequestHandler13255820
Ref: 41a213255820
Node: DocXMLRPCServer Objects13256140
Ref: library/xmlrpc server doc-xmlrpc-servers13256308
Ref: 41a313256308
Ref: library/xmlrpc server docxmlrpcserver-objects13256308
Ref: 41a413256308
Ref: library/xmlrpc server xmlrpc server DocXMLRPCServer set_server_title13256745
Ref: 41a513256745
Ref: library/xmlrpc server xmlrpc server DocXMLRPCServer set_server_name13256933
Ref: 41a613256933
Ref: library/xmlrpc server xmlrpc server DocXMLRPCServer set_server_documentation13257153
Ref: 41a713257153
Node: DocCGIXMLRPCRequestHandler13257409
Ref: library/xmlrpc server doccgixmlrpcrequesthandler13257543
Ref: 41a813257543
Ref: library/xmlrpc server xmlrpc server DocCGIXMLRPCRequestHandler set_server_title13257994
Ref: 41a913257994
Ref: library/xmlrpc server xmlrpc server DocCGIXMLRPCRequestHandler set_server_name13258193
Ref: 41aa13258193
Ref: library/xmlrpc server xmlrpc server DocCGIXMLRPCRequestHandler set_server_documentation13258424
Ref: 41ab13258424
Node: ipaddress — IPv4/IPv6 manipulation library13258691
Ref: library/ipaddress doc13258850
Ref: 41ac13258850
Ref: library/ipaddress ipaddress-ipv4-ipv6-manipulation-library13258850
Ref: 41ad13258850
Ref: library/ipaddress module-ipaddress13258850
Ref: 8413258850
Ref: library/ipaddress translation-repo13258850
Ref: 41ae13258850
Ref: ipaddress — IPv4/IPv6 manipulation library-Footnote-113259875
Node: Convenience factory functions13259944
Ref: library/ipaddress convenience-factory-functions13260075
Ref: 41b013260075
Ref: library/ipaddress ipaddress ip_address13260278
Ref: 41b113260278
Ref: library/ipaddress ipaddress ip_network13260863
Ref: 41b213260863
Ref: library/ipaddress ipaddress ip_interface13261578
Ref: 41b313261578
Node: IP Addresses13262437
Ref: library/ipaddress ip-addresses13262599
Ref: 41b413262599
Node: Address objects13262742
Ref: library/ipaddress address-objects13262849
Ref: 41b513262849
Ref: library/ipaddress ipaddress IPv4Address13263288
Ref: 50d13263288
Ref: library/ipaddress ipaddress IPv4Address version13264589
Ref: 41b713264589
Ref: library/ipaddress ipaddress IPv4Address max_prefixlen13264767
Ref: 41b813264767
Ref: library/ipaddress ipaddress IPv4Address compressed13265175
Ref: 41b913265175
Ref: library/ipaddress ipaddress IPv4Address exploded13265207
Ref: 41ba13265207
Ref: library/ipaddress ipaddress IPv4Address packed13265696
Ref: 41bb13265696
Ref: library/ipaddress ipaddress IPv4Address reverse_pointer13265933
Ref: 102213265933
Ref: library/ipaddress ipaddress IPv4Address is_multicast13266480
Ref: 41bc13266480
Ref: library/ipaddress ipaddress IPv4Address is_private13266647
Ref: 19ab13266647
Ref: library/ipaddress ipaddress IPv4Address is_global13268303
Ref: 116113268303
Ref: library/ipaddress ipaddress IPv4Address is_unspecified13269223
Ref: 41be13269223
Ref: library/ipaddress ipaddress IPv4Address is_reserved13269377
Ref: 41bf13269377
Ref: library/ipaddress ipaddress IPv4Address is_loopback13270085
Ref: 41c113270085
Ref: library/ipaddress ipaddress IPv4Address is_link_local13270238
Ref: 41c213270238
Ref: library/ipaddress ipaddress IPv4Address ipv6_mapped13270373
Ref: 50c13270373
Ref: library/ipaddress ipaddress IPv4Address __format__13270554
Ref: 41c313270554
Ref: library/ipaddress ipaddress IPv6Address13271804
Ref: 50e13271804
Ref: library/ipaddress ipaddress IPv6Address compressed13273178
Ref: 41c413273178
Ref: library/ipaddress ipaddress IPv6Address exploded13273487
Ref: 41c513273487
Ref: library/ipaddress ipaddress IPv6Address packed13273775
Ref: 41c613273775
Ref: library/ipaddress ipaddress IPv6Address reverse_pointer13273803
Ref: 192213273803
Ref: library/ipaddress ipaddress IPv6Address version13273840
Ref: 41c713273840
Ref: library/ipaddress ipaddress IPv6Address max_prefixlen13273869
Ref: 41c813273869
Ref: library/ipaddress ipaddress IPv6Address is_multicast13273904
Ref: 41c913273904
Ref: library/ipaddress ipaddress IPv6Address is_private13273938
Ref: 19ac13273938
Ref: library/ipaddress ipaddress IPv6Address is_global13273970
Ref: 19ad13273970
Ref: library/ipaddress ipaddress IPv6Address is_unspecified13274034
Ref: 41ca13274034
Ref: library/ipaddress ipaddress IPv6Address is_reserved13274070
Ref: 41cb13274070
Ref: library/ipaddress ipaddress IPv6Address is_loopback13274103
Ref: 199213274103
Ref: library/ipaddress ipaddress IPv6Address is_link_local13274136
Ref: 41cc13274136
Ref: library/ipaddress ipaddress IPv6Address is_site_local13274171
Ref: 41c013274171
Ref: library/ipaddress ipaddress IPv6Address ipv4_mapped13274517
Ref: 41bd13274517
Ref: library/ipaddress ipaddress IPv6Address scope_id13274789
Ref: b0c13274789
Ref: library/ipaddress ipaddress IPv6Address sixtofour13275089
Ref: 41cd13275089
Ref: library/ipaddress ipaddress IPv6Address teredo13275379
Ref: 41ce13275379
Ref: library/ipaddress ipaddress IPv6Address __format__13275693
Ref: 41cf13275693
Ref: Address objects-Footnote-113275885
Ref: Address objects-Footnote-213275944
Ref: Address objects-Footnote-313276003
Ref: Address objects-Footnote-413276105
Ref: Address objects-Footnote-513276207
Ref: Address objects-Footnote-613276309
Ref: Address objects-Footnote-713276411
Ref: Address objects-Footnote-813276470
Ref: Address objects-Footnote-913276529
Ref: Address objects-Footnote-1013276615
Ref: Address objects-Footnote-1113276718
Ref: Address objects-Footnote-1213276778
Ref: Address objects-Footnote-1313276838
Ref: Address objects-Footnote-1413276898
Ref: Address objects-Footnote-1513276958
Ref: Address objects-Footnote-1613277018
Ref: Address objects-Footnote-1713277078
Ref: Address objects-Footnote-1813277138
Ref: Address objects-Footnote-1913277198
Ref: Address objects-Footnote-2013277258
Ref: Address objects-Footnote-2113277318
Ref: Address objects-Footnote-2213277378
Node: Conversion to Strings and Integers13277438
Ref: library/ipaddress conversion-to-strings-and-integers13277566
Ref: 41d013277566
Node: Operators<2>13278190
Ref: library/ipaddress operators13278294
Ref: 41d113278294
Node: Comparison operators13278559
Ref: library/ipaddress comparison-operators13278657
Ref: 41d213278657
Node: Arithmetic operators13279251
Ref: library/ipaddress arithmetic-operators13279349
Ref: 41d313279349
Node: IP Network definitions13279852
Ref: library/ipaddress ip-network-definitions13280002
Ref: 41d413280002
Node: Prefix net mask and host mask13280712
Ref: library/ipaddress prefix-net-mask-and-host-mask13280824
Ref: 41d513280824
Node: Network objects13281494
Ref: library/ipaddress network-objects13281627
Ref: 41d613281627
Ref: library/ipaddress ipaddress IPv4Network13282085
Ref: 50f13282085
Ref: library/ipaddress ipaddress IPv4Network version13284526
Ref: 41d813284526
Ref: library/ipaddress ipaddress IPv4Network max_prefixlen13284555
Ref: 41d913284555
Ref: library/ipaddress ipaddress IPv4Network is_multicast13284689
Ref: 41da13284689
Ref: library/ipaddress ipaddress IPv4Network is_private13284723
Ref: 41db13284723
Ref: library/ipaddress ipaddress IPv4Network is_unspecified13284755
Ref: 41dc13284755
Ref: library/ipaddress ipaddress IPv4Network is_reserved13284791
Ref: 41dd13284791
Ref: library/ipaddress ipaddress IPv4Network is_loopback13284824
Ref: 41de13284824
Ref: library/ipaddress ipaddress IPv4Network is_link_local13284857
Ref: 41df13284857
Ref: library/ipaddress ipaddress IPv4Network network_address13285049
Ref: 41e013285049
Ref: library/ipaddress ipaddress IPv4Network broadcast_address13285223
Ref: 41e113285223
Ref: library/ipaddress ipaddress IPv4Network hostmask13285420
Ref: 41e213285420
Ref: library/ipaddress ipaddress IPv4Network netmask13285514
Ref: 41e313285514
Ref: library/ipaddress ipaddress IPv4Network with_prefixlen13285606
Ref: 41e413285606
Ref: library/ipaddress ipaddress IPv4Network compressed13285642
Ref: 41e513285642
Ref: library/ipaddress ipaddress IPv4Network exploded13285674
Ref: 41e613285674
Ref: library/ipaddress ipaddress IPv4Network with_netmask13285975
Ref: 41e713285975
Ref: library/ipaddress ipaddress IPv4Network with_hostmask13286106
Ref: 41e813286106
Ref: library/ipaddress ipaddress IPv4Network num_addresses13286239
Ref: 41e913286239
Ref: library/ipaddress ipaddress IPv4Network prefixlen13286331
Ref: 41ea13286331
Ref: library/ipaddress ipaddress IPv4Network hosts13286412
Ref: 179613286412
Ref: library/ipaddress ipaddress IPv4Network overlaps13287409
Ref: 41eb13287409
Ref: library/ipaddress ipaddress IPv4Network address_exclude13287581
Ref: 41ec13287581
Ref: library/ipaddress ipaddress IPv4Network subnets13288187
Ref: 10a213288187
Ref: library/ipaddress ipaddress IPv4Network supernet13289735
Ref: 10a313289735
Ref: library/ipaddress ipaddress IPv4Network subnet_of13290541
Ref: 41ed13290541
Ref: library/ipaddress ipaddress IPv4Network supernet_of13290840
Ref: 41ee13290840
Ref: library/ipaddress ipaddress IPv4Network compare_networks13291145
Ref: 41ef13291145
Ref: library/ipaddress ipaddress IPv6Network13291837
Ref: 51013291837
Ref: library/ipaddress ipaddress IPv6Network version13293672
Ref: 41f013293672
Ref: library/ipaddress ipaddress IPv6Network max_prefixlen13293701
Ref: 41f113293701
Ref: library/ipaddress ipaddress IPv6Network is_multicast13293736
Ref: 41f213293736
Ref: library/ipaddress ipaddress IPv6Network is_private13293770
Ref: 41f313293770
Ref: library/ipaddress ipaddress IPv6Network is_unspecified13293802
Ref: 41f413293802
Ref: library/ipaddress ipaddress IPv6Network is_reserved13293838
Ref: 41f513293838
Ref: library/ipaddress ipaddress IPv6Network is_loopback13293871
Ref: 41f613293871
Ref: library/ipaddress ipaddress IPv6Network is_link_local13293904
Ref: 41f713293904
Ref: library/ipaddress ipaddress IPv6Network network_address13293939
Ref: 41f813293939
Ref: library/ipaddress ipaddress IPv6Network broadcast_address13293976
Ref: 41f913293976
Ref: library/ipaddress ipaddress IPv6Network hostmask13294015
Ref: 41fa13294015
Ref: library/ipaddress ipaddress IPv6Network netmask13294045
Ref: 41fb13294045
Ref: library/ipaddress ipaddress IPv6Network with_prefixlen13294074
Ref: 41fc13294074
Ref: library/ipaddress ipaddress IPv6Network compressed13294110
Ref: 41fd13294110
Ref: library/ipaddress ipaddress IPv6Network exploded13294142
Ref: 41fe13294142
Ref: library/ipaddress ipaddress IPv6Network with_netmask13294172
Ref: 41ff13294172
Ref: library/ipaddress ipaddress IPv6Network with_hostmask13294206
Ref: 420013294206
Ref: library/ipaddress ipaddress IPv6Network num_addresses13294241
Ref: 420113294241
Ref: library/ipaddress ipaddress IPv6Network prefixlen13294276
Ref: 420213294276
Ref: library/ipaddress ipaddress IPv6Network hosts13294307
Ref: 179713294307
Ref: library/ipaddress ipaddress IPv6Network overlaps13294757
Ref: 420313294757
Ref: library/ipaddress ipaddress IPv6Network address_exclude13294792
Ref: 420413294792
Ref: library/ipaddress ipaddress IPv6Network subnets13294836
Ref: 420513294836
Ref: library/ipaddress ipaddress IPv6Network supernet13294898
Ref: 420613294898
Ref: library/ipaddress ipaddress IPv6Network subnet_of13294961
Ref: 420713294961
Ref: library/ipaddress ipaddress IPv6Network supernet_of13294997
Ref: 420813294997
Ref: library/ipaddress ipaddress IPv6Network compare_networks13295035
Ref: 420913295035
Ref: library/ipaddress ipaddress IPv6Network is_site_local13295177
Ref: 420a13295177
Node: Operators<3>13295353
Ref: library/ipaddress id113295448
Ref: 420b13295448
Node: Logical operators13295741
Ref: library/ipaddress logical-operators13295825
Ref: 420c13295825
Node: Iteration13296030
Ref: library/ipaddress iteration13296158
Ref: 420d13296158
Node: Networks as containers of addresses13296986
Ref: library/ipaddress networks-as-containers-of-addresses13297088
Ref: 420e13297088
Node: Interface objects13297546
Ref: library/ipaddress interface-objects13297712
Ref: 420f13297712
Ref: library/ipaddress ipaddress IPv4Interface13297860
Ref: 1b8113297860
Ref: library/ipaddress ipaddress IPv4Interface ip13298277
Ref: 421013298277
Ref: library/ipaddress ipaddress IPv4Interface network13298523
Ref: 421113298523
Ref: library/ipaddress ipaddress IPv4Interface with_prefixlen13298780
Ref: 421213298780
Ref: library/ipaddress ipaddress IPv4Interface with_netmask13299048
Ref: 421313299048
Ref: library/ipaddress ipaddress IPv4Interface with_hostmask13299321
Ref: 421413299321
Ref: library/ipaddress ipaddress IPv6Interface13299593
Ref: 1b8213299593
Ref: library/ipaddress ipaddress IPv6Interface ip13300010
Ref: 421513300010
Ref: library/ipaddress ipaddress IPv6Interface network13300034
Ref: 421613300034
Ref: library/ipaddress ipaddress IPv6Interface with_prefixlen13300063
Ref: 421713300063
Ref: library/ipaddress ipaddress IPv6Interface with_netmask13300099
Ref: 421813300099
Ref: library/ipaddress ipaddress IPv6Interface with_hostmask13300133
Ref: 421913300133
Node: Operators<4>13300307
Ref: library/ipaddress id213300373
Ref: 421a13300373
Node: Logical operators<2>13300635
Ref: library/ipaddress id313300704
Ref: 421b13300704
Node: Other Module Level Functions13301361
Ref: library/ipaddress other-module-level-functions13301522
Ref: 421c13301522
Ref: library/ipaddress ipaddress v4_int_to_packed13301667
Ref: 421d13301667
Ref: library/ipaddress ipaddress v6_int_to_packed13302141
Ref: 421e13302141
Ref: library/ipaddress ipaddress summarize_address_range13302450
Ref: 10a413302450
Ref: library/ipaddress ipaddress collapse_addresses13303329
Ref: 10a513303329
Ref: library/ipaddress ipaddress get_mixed_type_key13303910
Ref: 421f13303910
Node: Custom Exceptions13304509
Ref: library/ipaddress custom-exceptions13304644
Ref: 422013304644
Ref: library/ipaddress ipaddress AddressValueError13304815
Ref: 41b613304815
Ref: library/ipaddress ipaddress NetmaskValueError13304918
Ref: 41d713304918
Node: Multimedia Services13305022
Ref: library/mm doc13305173
Ref: 422113305173
Ref: library/mm mmedia13305173
Ref: 422213305173
Ref: library/mm multimedia-services13305173
Ref: 422313305173
Ref: library/mm translation-repo13305173
Ref: 422413305173
Node: wave — Read and write WAV files13305539
Ref: library/wave doc13305683
Ref: 422513305683
Ref: library/wave module-wave13305683
Ref: 11913305683
Ref: library/wave wave-read-and-write-wav-files13305683
Ref: 422613305683
Ref: library/wave wave open13306281
Ref: b4713306281
Ref: library/wave wave Error13307349
Ref: 422913307349
Ref: wave — Read and write WAV files-Footnote-113307603
Node: Wave_read Objects13307667
Ref: library/wave id113307781
Ref: 422a13307781
Ref: library/wave wave-read-objects13307781
Ref: 422b13307781
Ref: library/wave wave Wave_read13307836
Ref: 33613307836
Ref: library/wave wave Wave_read close13307979
Ref: 422713307979
Ref: library/wave wave Wave_read getnchannels13308175
Ref: 422c13308175
Ref: library/wave wave Wave_read getsampwidth13308303
Ref: 422d13308303
Ref: library/wave wave Wave_read getframerate13308379
Ref: 422e13308379
Ref: library/wave wave Wave_read getnframes13308452
Ref: 422f13308452
Ref: library/wave wave Wave_read getcomptype13308527
Ref: 423013308527
Ref: library/wave wave Wave_read getcompname13308649
Ref: 423113308649
Ref: library/wave wave Wave_read getparams13308812
Ref: 11ec13308812
Ref: library/wave wave Wave_read readframes13309029
Ref: 423213309029
Ref: library/wave wave Wave_read rewind13309161
Ref: 423313309161
Ref: library/wave wave Wave_read getmarkers13309398
Ref: 33513309398
Ref: library/wave wave Wave_read getmark13309664
Ref: 33413309664
Ref: library/wave wave Wave_read setpos13310066
Ref: 423413310066
Ref: library/wave wave Wave_read tell13310156
Ref: 423513310156
Node: Wave_write Objects13310231
Ref: library/wave id213310345
Ref: 423613310345
Ref: library/wave wave-write-objects13310345
Ref: 11ed13310345
Ref: library/wave wave Wave_write13310402
Ref: 33713310402
Ref: library/wave wave Wave_write close13311442
Ref: 422813311442
Ref: library/wave wave Wave_write setnchannels13311788
Ref: 423913311788
Ref: library/wave wave Wave_write setsampwidth13311862
Ref: 423a13311862
Ref: library/wave wave Wave_write setframerate13311943
Ref: 423b13311943
Ref: library/wave wave Wave_write setnframes13312137
Ref: 423713312137
Ref: library/wave wave Wave_write setcomptype13312406
Ref: 423c13312406
Ref: library/wave wave Wave_write setparams13312599
Ref: 423813312599
Ref: library/wave wave Wave_write tell13312828
Ref: 423d13312828
Ref: library/wave wave Wave_write writeframesraw13313030
Ref: 11ee13313030
Ref: library/wave wave Wave_write writeframes13313232
Ref: 11ef13313232
Node: colorsys — Conversions between color systems13313887
Ref: library/colorsys doc13314031
Ref: 423e13314031
Ref: library/colorsys colorsys-conversions-between-color-systems13314031
Ref: 423f13314031
Ref: library/colorsys module-colorsys13314031
Ref: 2013314031
Ref: library/colorsys translation-repo13314031
Ref: 424013314031
Ref: library/colorsys colorsys rgb_to_yiq13315022
Ref: 424113315022
Ref: library/colorsys colorsys yiq_to_rgb13315132
Ref: 424213315132
Ref: library/colorsys colorsys rgb_to_hls13315242
Ref: 1a5a13315242
Ref: library/colorsys colorsys hls_to_rgb13315352
Ref: 424313315352
Ref: library/colorsys colorsys rgb_to_hsv13315462
Ref: 424413315462
Ref: library/colorsys colorsys hsv_to_rgb13315572
Ref: 424513315572
Ref: colorsys — Conversions between color systems-Footnote-113315884
Node: Internationalization13315952
Ref: library/i18n doc13316106
Ref: 424613316106
Ref: library/i18n i18n13316106
Ref: 424713316106
Ref: library/i18n internationalization13316106
Ref: 424813316106
Ref: library/i18n translation-repo13316106
Ref: 424913316106
Node: gettext — Multilingual internationalization services13316561
Ref: library/gettext doc13316721
Ref: 424a13316721
Ref: library/gettext gettext-multilingual-internationalization-services13316721
Ref: 424b13316721
Ref: library/gettext module-gettext13316721
Ref: 6713316721
Ref: gettext — Multilingual internationalization services-Footnote-113317698
Node: GNU gettext API13317765
Ref: library/gettext gnu-gettext-api13317895
Ref: 424c13317895
Ref: library/gettext gettext bindtextdomain13318439
Ref: 424d13318439
Ref: library/gettext gettext textdomain13319011
Ref: 424e13319011
Ref: library/gettext gettext gettext13319257
Ref: 167013319257
Ref: library/gettext gettext dgettext13319526
Ref: 424f13319526
Ref: library/gettext gettext ngettext13319666
Ref: 425013319666
Ref: library/gettext gettext dngettext13320377
Ref: 425113320377
Ref: library/gettext gettext pgettext13320531
Ref: bea13320531
Ref: library/gettext gettext dpgettext13320582
Ref: 425213320582
Ref: library/gettext gettext npgettext13320642
Ref: 425313320642
Ref: library/gettext gettext dnpgettext13320706
Ref: 425413320706
Ref: GNU gettext API-Footnote-113321525
Ref: GNU gettext API-Footnote-213322005
Node: Class-based API13322070
Ref: library/gettext class-based-api13322253
Ref: 425513322253
Ref: library/gettext gettext find13322783
Ref: 425713322783
Ref: library/gettext gettext translation13324232
Ref: c6f13324232
Ref: library/gettext gettext install13325481
Ref: c7013325481
Ref: Class-based API-Footnote-113326526
Node: The NullTranslations class13326592
Ref: library/gettext the-nulltranslations-class13326704
Ref: 425a13326704
Ref: library/gettext gettext NullTranslations13327149
Ref: 425813327149
Ref: library/gettext gettext NullTranslations _parse13327548
Ref: 425c13327548
Ref: library/gettext gettext NullTranslations add_fallback13327859
Ref: 425b13327859
Ref: library/gettext gettext NullTranslations gettext13328122
Ref: 425d13328122
Ref: library/gettext gettext NullTranslations ngettext13328320
Ref: 425e13328320
Ref: library/gettext gettext NullTranslations pgettext13328572
Ref: 425f13328572
Ref: library/gettext gettext NullTranslations npgettext13328832
Ref: 426013328832
Ref: library/gettext gettext NullTranslations info13329107
Ref: 426113329107
Ref: library/gettext gettext NullTranslations charset13329233
Ref: 426213329233
Ref: library/gettext gettext NullTranslations install13329322
Ref: 425913329322
Node: The GNUTranslations class13330529
Ref: library/gettext the-gnutranslations-class13330681
Ref: 426313330681
Ref: library/gettext gettext GNUTranslations13332182
Ref: 425613332182
Ref: library/gettext gettext GNUTranslations gettext13332303
Ref: 426413332303
Ref: library/gettext gettext GNUTranslations ngettext13332712
Ref: 426513332712
Ref: library/gettext gettext GNUTranslations pgettext13333636
Ref: 426613333636
Ref: library/gettext gettext GNUTranslations npgettext13334114
Ref: 426713334114
Ref: The GNUTranslations class-Footnote-113334763
Node: Solaris message catalog support13334821
Ref: library/gettext solaris-message-catalog-support13334970
Ref: 426813334970
Node: The Catalog constructor13335219
Ref: library/gettext the-catalog-constructor13335334
Ref: 426913335334
Node: Internationalizing your programs and modules13335992
Ref: library/gettext i18n-howto13336179
Ref: 33b113336179
Ref: library/gettext internationalizing-your-programs-and-modules13336179
Ref: 426a13336179
Ref: Internationalizing your programs and modules-Footnote-113339759
Ref: Internationalizing your programs and modules-Footnote-213339792
Node: Localizing your module13339835
Ref: library/gettext localizing-your-module13339974
Ref: 426b13339974
Node: Localizing your application13340567
Ref: library/gettext localizing-your-application13340744
Ref: 426c13340744
Node: Changing languages on the fly13341472
Ref: library/gettext changing-languages-on-the-fly13341648
Ref: 426d13341648
Node: Deferred translations13342327
Ref: library/gettext deferred-translations13342467
Ref: 426e13342467
Node: Acknowledgements<9>13344705
Ref: library/gettext acknowledgements13344868
Ref: 426f13344868
Node: locale — Internationalization services13345264
Ref: library/locale doc13345424
Ref: 427013345424
Ref: library/locale locale-internationalization-services13345424
Ref: 427113345424
Ref: library/locale module-locale13345424
Ref: 8a13345424
Ref: library/locale translation-repo13345424
Ref: 427213345424
Ref: library/locale locale Error13346152
Ref: 427313346152
Ref: library/locale locale setlocale13346278
Ref: 32813346278
Ref: library/locale locale localeconv13348200
Ref: dfa13348200
Ref: library/locale locale nl_langinfo13356506
Ref: 45413356506
Ref: library/locale locale CODESET13357026
Ref: 427813357026
Ref: library/locale locale D_T_FMT13357160
Ref: 427913357160
Ref: library/locale locale D_FMT13357357
Ref: 427a13357357
Ref: library/locale locale T_FMT13357545
Ref: 427b13357545
Ref: library/locale locale T_FMT_AMPM13357733
Ref: 427c13357733
Ref: library/locale locale DAY_113357880
Ref: 427d13357880
Ref: library/locale locale DAY_213357908
Ref: 427e13357908
Ref: library/locale locale DAY_313357936
Ref: 427f13357936
Ref: library/locale locale DAY_413357964
Ref: 428013357964
Ref: library/locale locale DAY_513357992
Ref: 428113357992
Ref: library/locale locale DAY_613358020
Ref: 428213358020
Ref: library/locale locale DAY_713358048
Ref: 428313358048
Ref: library/locale locale ABDAY_113358335
Ref: 428413358335
Ref: library/locale locale ABDAY_213358365
Ref: 428513358365
Ref: library/locale locale ABDAY_313358395
Ref: 428613358395
Ref: library/locale locale ABDAY_413358425
Ref: 428713358425
Ref: library/locale locale ABDAY_513358455
Ref: 428813358455
Ref: library/locale locale ABDAY_613358485
Ref: 428913358485
Ref: library/locale locale ABDAY_713358515
Ref: 428a13358515
Ref: library/locale locale MON_113358611
Ref: 428b13358611
Ref: library/locale locale MON_213358639
Ref: 428c13358639
Ref: library/locale locale MON_313358667
Ref: 428d13358667
Ref: library/locale locale MON_413358695
Ref: 428e13358695
Ref: library/locale locale MON_513358723
Ref: 428f13358723
Ref: library/locale locale MON_613358751
Ref: 429013358751
Ref: library/locale locale MON_713358779
Ref: 429113358779
Ref: library/locale locale MON_813358807
Ref: 429213358807
Ref: library/locale locale MON_913358835
Ref: 429313358835
Ref: library/locale locale MON_1013358863
Ref: 429413358863
Ref: library/locale locale MON_1113358892
Ref: 429513358892
Ref: library/locale locale MON_1213358921
Ref: 429613358921
Ref: library/locale locale ABMON_113358994
Ref: 429713358994
Ref: library/locale locale ABMON_213359024
Ref: 429813359024
Ref: library/locale locale ABMON_313359054
Ref: 429913359054
Ref: library/locale locale ABMON_413359084
Ref: 429a13359084
Ref: library/locale locale ABMON_513359114
Ref: 429b13359114
Ref: library/locale locale ABMON_613359144
Ref: 429c13359144
Ref: library/locale locale ABMON_713359174
Ref: 429d13359174
Ref: library/locale locale ABMON_813359204
Ref: 429e13359204
Ref: library/locale locale ABMON_913359234
Ref: 429f13359234
Ref: library/locale locale ABMON_1013359264
Ref: 42a013359264
Ref: library/locale locale ABMON_1113359295
Ref: 42a113359295
Ref: library/locale locale ABMON_1213359326
Ref: 42a213359326
Ref: library/locale locale RADIXCHAR13359413
Ref: 42a313359413
Ref: library/locale locale THOUSEP13359517
Ref: 42a413359517
Ref: library/locale locale YESEXPR13359637
Ref: 42a513359637
Ref: library/locale locale NOEXPR13359820
Ref: 42a613359820
Ref: library/locale locale CRNCYSTR13360277
Ref: 42a713360277
Ref: library/locale locale ERA13360549
Ref: 42a813360549
Ref: library/locale locale ERA_D_T_FMT13361368
Ref: 42a913361368
Ref: library/locale locale ERA_D_FMT13361540
Ref: 42aa13361540
Ref: library/locale locale ERA_T_FMT13361703
Ref: 42ab13361703
Ref: library/locale locale ALT_DIGITS13361866
Ref: 42ac13361866
Ref: library/locale locale getdefaultlocale13362548
Ref: 32613362548
Ref: library/locale locale getlocale13363920
Ref: 32713363920
Ref: library/locale locale getpreferredencoding13364494
Ref: 75d13364494
Ref: library/locale locale getencoding13365586
Ref: 32913365586
Ref: library/locale locale normalize13366360
Ref: 42b013366360
Ref: library/locale locale strcoll13366780
Ref: 42b113366780
Ref: library/locale locale strxfrm13367099
Ref: 17a513367099
Ref: library/locale locale format_string13367443
Ref: 74313367443
Ref: library/locale locale currency13368155
Ref: 42b313368155
Ref: library/locale locale str13368802
Ref: 42b413368802
Ref: library/locale locale delocalize13368991
Ref: 102813368991
Ref: library/locale locale localize13369171
Ref: 42b513369171
Ref: library/locale locale atof13369391
Ref: 42b613369391
Ref: library/locale locale atoi13369616
Ref: 42b713369616
Ref: library/locale locale LC_CTYPE13369747
Ref: 42ae13369747
Ref: library/locale locale LC_COLLATE13370410
Ref: 42b213370410
Ref: library/locale locale LC_TIME13370603
Ref: 42b813370603
Ref: library/locale locale LC_MONETARY13370754
Ref: 427713370754
Ref: library/locale locale LC_MESSAGES13370927
Ref: 42b913370927
Ref: library/locale locale LC_NUMERIC13371349
Ref: 427513371349
Ref: library/locale locale LC_ALL13371672
Ref: 42ad13371672
Ref: library/locale locale CHAR_MAX13372097
Ref: 427613372097
Ref: locale — Internationalization services-Footnote-113372468
Ref: locale — Internationalization services-Footnote-213372534
Ref: locale — Internationalization services-Footnote-313372632
Ref: locale — Internationalization services-Footnote-413372674
Node: Background details hints tips and caveats13372716
Ref: library/locale background-details-hints-tips-and-caveats13372855
Ref: 42ba13372855
Node: Locale names13375062
Ref: library/locale locale-name13375262
Ref: 427413375262
Ref: library/locale locale-names13375262
Ref: 42bb13375262
Ref: Locale names-Footnote-113376898
Ref: Locale names-Footnote-213377048
Ref: Locale names-Footnote-313377098
Ref: Locale names-Footnote-413377154
Ref: Locale names-Footnote-513377327
Ref: Locale names-Footnote-613377416
Ref: Locale names-Footnote-713377462
Node: For extension writers and programs that embed Python13377504
Ref: library/locale embedding-locale13377689
Ref: 42bc13377689
Ref: library/locale for-extension-writers-and-programs-that-embed-python13377689
Ref: 42bd13377689
Node: Access to message catalogs13378486
Ref: library/locale access-to-message-catalogs13378650
Ref: 42be13378650
Ref: library/locale locale-gettext13378650
Ref: 42bf13378650
Ref: library/locale locale gettext13378723
Ref: 42c013378723
Ref: library/locale locale dgettext13378759
Ref: 42c113378759
Ref: library/locale locale dcgettext13378804
Ref: 42c213378804
Ref: library/locale locale textdomain13378860
Ref: 42c313378860
Ref: library/locale locale bindtextdomain13378902
Ref: 42c413378902
Ref: library/locale locale bind_textdomain_codeset13378953
Ref: 42c513378953
Node: Graphical user interfaces with Tk13379940
Ref: library/tk doc13380092
Ref: 42c613380092
Ref: library/tk graphical-user-interfaces-with-tk13380092
Ref: 42c713380092
Ref: library/tk tkinter13380092
Ref: 42c813380092
Ref: library/tk translation-repo13380092
Ref: 42c913380092
Ref: Graphical user interfaces with Tk-Footnote-113381990
Node: tkinter — Python interface to Tcl/Tk13382042
Ref: library/tkinter doc13382205
Ref: 42ca13382205
Ref: library/tkinter module-tkinter13382205
Ref: f613382205
Ref: library/tkinter tkinter-python-interface-to-tcl-tk13382205
Ref: 42cb13382205
Ref: tkinter — Python interface to Tcl/Tk-Footnote-113385348
Ref: tkinter — Python interface to Tcl/Tk-Footnote-213385425
Ref: tkinter — Python interface to Tcl/Tk-Footnote-313385453
Ref: tkinter — Python interface to Tcl/Tk-Footnote-413385493
Ref: tkinter — Python interface to Tcl/Tk-Footnote-513385550
Ref: tkinter — Python interface to Tcl/Tk-Footnote-613385577
Ref: tkinter — Python interface to Tcl/Tk-Footnote-713385614
Ref: tkinter — Python interface to Tcl/Tk-Footnote-813385712
Ref: tkinter — Python interface to Tcl/Tk-Footnote-913385764
Node: Architecture13385823
Ref: library/tkinter architecture13385934
Ref: 42cc13385934
Ref: Architecture-Footnote-113388266
Node: Tkinter Modules13388306
Ref: library/tkinter tkinter-modules13388448
Ref: 42ce13388448
Ref: library/tkinter tkinter Tk13388775
Ref: 199413388775
Ref: library/tkinter tkinter Tk tk13390924
Ref: 42d013390924
Ref: library/tkinter tkinter Tk master13391223
Ref: 42d113391223
Ref: library/tkinter tkinter Tk children13391810
Ref: 42d213391810
Ref: library/tkinter tkinter Tcl13392020
Ref: 42cf13392020
Ref: library/tkinter module-_tkinter13393618
Ref: 313393618
Node: Tkinter Life Preserver13394530
Ref: library/tkinter tkinter-life-preserver13394675
Ref: 42d313394675
Node: A Hello World Program13395503
Ref: library/tkinter a-hello-world-program13395613
Ref: 42d413395613
Node: Important Tk Concepts13397076
Ref: library/tkinter important-tk-concepts13397233
Ref: 42d513397233
Node: Understanding How Tkinter Wraps Tcl/Tk13398581
Ref: library/tkinter understanding-how-tkinter-wraps-tcl-tk13398750
Ref: 42d613398750
Node: How do I…? What option does…?13400899
Ref: library/tkinter how-do-i-what-option-does13401085
Ref: 42d713401085
Node: Navigating the Tcl/Tk Reference Manual13402832
Ref: library/tkinter navigating-the-tcl-tk-reference-manual13402971
Ref: 42d813402971
Ref: Navigating the Tcl/Tk Reference Manual-Footnote-113405049
Ref: Navigating the Tcl/Tk Reference Manual-Footnote-213405106
Ref: Navigating the Tcl/Tk Reference Manual-Footnote-313405165
Ref: Navigating the Tcl/Tk Reference Manual-Footnote-413405218
Ref: Navigating the Tcl/Tk Reference Manual-Footnote-513405274
Ref: Navigating the Tcl/Tk Reference Manual-Footnote-613405333
Node: Threading model13405387
Ref: library/tkinter threading-model13405532
Ref: 42cd13405532
Node: Handy Reference13408554
Ref: library/tkinter handy-reference13408690
Ref: 42d913408690
Node: Setting Options13408944
Ref: library/tkinter setting-options13409030
Ref: 42da13409030
Ref: library/tkinter tkinter-setting-options13409030
Ref: 42db13409030
Ref: Setting Options-Footnote-113412270
Node: The Packer13412317
Ref: library/tkinter the-packer13412426
Ref: 42dc13412426
Node: Packer Options13414058
Ref: library/tkinter packer-options13414177
Ref: 42dd13414177
Node: Coupling Widget Variables13414869
Ref: library/tkinter coupling-widget-variables13414996
Ref: 42de13414996
Node: The Window Manager13417196
Ref: library/tkinter the-window-manager13417329
Ref: 42df13417329
Node: Tk Option Data Types13418734
Ref: library/tkinter tk-option-data-types13418861
Ref: 42e013418861
Node: Bindings and Events13421904
Ref: library/tkinter bindings-and-events13422032
Ref: 42e113422032
Ref: library/tkinter id213422032
Ref: 42e213422032
Ref: Bindings and Events-Footnote-113424864
Node: The index Parameter13424910
Ref: library/tkinter the-index-parameter13425024
Ref: 42e313425024
Node: Images13426956
Ref: library/tkinter images13427042
Ref: 42e413427042
Ref: Images-Footnote-113428348
Node: File Handlers13428383
Ref: library/tkinter file-handlers13428495
Ref: 42e513428495
Ref: library/tkinter tkinter-file-handlers13428495
Ref: 42e613428495
Ref: library/tkinter tkinter Widget tk createfilehandler13429437
Ref: 42e713429437
Ref: library/tkinter tkinter Widget tk deletefilehandler13429872
Ref: 42e813429872
Ref: library/tkinter tkinter READABLE13429954
Ref: 42e913429954
Ref: library/tkinter tkinter WRITABLE13429982
Ref: 42ea13429982
Ref: library/tkinter tkinter EXCEPTION13430010
Ref: 42eb13430010
Node: tkinter colorchooser — Color choosing dialog13430086
Ref: library/tkinter colorchooser doc13430295
Ref: 42ec13430295
Ref: library/tkinter colorchooser module-tkinter colorchooser13430295
Ref: f713430295
Ref: library/tkinter colorchooser tkinter-colorchooser-color-choosing-dialog13430295
Ref: 42ed13430295
Ref: library/tkinter colorchooser translation-repo13430295
Ref: 42ee13430295
Ref: library/tkinter colorchooser tkinter colorchooser Chooser13430793
Ref: 42ef13430793
Ref: library/tkinter colorchooser tkinter colorchooser askcolor13430860
Ref: 42f113430860
Ref: tkinter colorchooser — Color choosing dialog-Footnote-113431258
Node: tkinter font — Tkinter font wrapper13431339
Ref: library/tkinter font doc13431525
Ref: 42f213431525
Ref: library/tkinter font module-tkinter font13431525
Ref: fb13431525
Ref: library/tkinter font tkinter-font-tkinter-font-wrapper13431525
Ref: 42f313431525
Ref: library/tkinter font translation-repo13431525
Ref: 42f413431525
Ref: library/tkinter font tkinter font NORMAL13431882
Ref: 42f513431882
Ref: library/tkinter font tkinter font BOLD13431912
Ref: 42f613431912
Ref: library/tkinter font tkinter font ITALIC13431940
Ref: 42f713431940
Ref: library/tkinter font tkinter font ROMAN13431970
Ref: 42f813431970
Ref: library/tkinter font tkinter font Font13432000
Ref: 1cb613432000
Ref: library/tkinter font tkinter font Font actual13433307
Ref: 42f913433307
Ref: library/tkinter font tkinter font Font cget13433408
Ref: 42fa13433408
Ref: library/tkinter font tkinter font Font config13433486
Ref: 42fb13433486
Ref: library/tkinter font tkinter font Font copy13433565
Ref: 42fc13433565
Ref: library/tkinter font tkinter font Font measure13433643
Ref: 42fd13433643
Ref: library/tkinter font tkinter font Font metrics13433902
Ref: 42fe13433902
Ref: library/tkinter font tkinter font families13434479
Ref: 42ff13434479
Ref: library/tkinter font tkinter font names13434586
Ref: 430013434586
Ref: library/tkinter font tkinter font nametofont13434673
Ref: 1cb813434673
Ref: tkinter font — Tkinter font wrapper-Footnote-113434902
Node: Tkinter Dialogs13434974
Ref: library/dialog doc13435160
Ref: 430113435160
Ref: library/dialog tkinter-dialogs13435160
Ref: 430213435160
Ref: library/dialog translation-repo13435160
Ref: 430313435160
Node: tkinter simpledialog — Standard Tkinter input dialogs13435531
Ref: library/dialog module-tkinter simpledialog13435692
Ref: fe13435692
Ref: library/dialog tkinter-simpledialog-standard-tkinter-input-dialogs13435692
Ref: 430413435692
Ref: library/dialog tkinter simpledialog askfloat13436095
Ref: 430513436095
Ref: library/dialog tkinter simpledialog askinteger13436161
Ref: 1cb913436161
Ref: library/dialog tkinter simpledialog askstring13436229
Ref: 430613436229
Ref: library/dialog tkinter simpledialog Dialog13436409
Ref: 430713436409
Ref: library/dialog tkinter simpledialog Dialog body13436512
Ref: 430813436512
Ref: library/dialog tkinter simpledialog Dialog buttonbox13436666
Ref: 430913436666
Ref: tkinter simpledialog — Standard Tkinter input dialogs-Footnote-113436837
Node: tkinter filedialog — File selection dialogs13436918
Ref: library/dialog module-tkinter filedialog13437136
Ref: fa13437136
Ref: library/dialog tkinter-filedialog-file-selection-dialogs13437136
Ref: 430a13437136
Ref: tkinter filedialog — File selection dialogs-Footnote-113437569
Node: Native Load/Save Dialogs13437648
Ref: library/dialog native-load-save-dialogs13437754
Ref: 430b13437754
Ref: library/dialog tkinter filedialog askopenfile13438763
Ref: 430c13438763
Ref: library/dialog tkinter filedialog askopenfiles13438830
Ref: 430d13438830
Ref: library/dialog tkinter filedialog asksaveasfile13439025
Ref: 430f13439025
Ref: library/dialog tkinter filedialog askopenfilename13439194
Ref: 431113439194
Ref: library/dialog tkinter filedialog askopenfilenames13439255
Ref: 431213439255
Ref: library/dialog tkinter filedialog asksaveasfilename13439466
Ref: 431313439466
Ref: library/dialog tkinter filedialog askdirectory13439611
Ref: 431413439611
Ref: library/dialog tkinter filedialog Open13439837
Ref: 430e13439837
Ref: library/dialog tkinter filedialog SaveAs13439898
Ref: 431013439898
Ref: library/dialog tkinter filedialog Directory13440220
Ref: 431513440220
Ref: library/dialog tkinter filedialog FileDialog13440453
Ref: 431613440453
Ref: library/dialog tkinter filedialog FileDialog cancel_command13440561
Ref: 431713440561
Ref: library/dialog tkinter filedialog FileDialog dirs_double_event13440664
Ref: 431813440664
Ref: library/dialog tkinter filedialog FileDialog dirs_select_event13440770
Ref: 431913440770
Ref: library/dialog tkinter filedialog FileDialog files_double_event13440869
Ref: 431a13440869
Ref: library/dialog tkinter filedialog FileDialog files_select_event13440971
Ref: 431b13440971
Ref: library/dialog tkinter filedialog FileDialog filter_command13441073
Ref: 431c13441073
Ref: library/dialog tkinter filedialog FileDialog get_filter13441161
Ref: 431d13441161
Ref: library/dialog tkinter filedialog FileDialog get_selection13441247
Ref: 431e13441247
Ref: library/dialog tkinter filedialog FileDialog go13441331
Ref: 431f13441331
Ref: library/dialog tkinter filedialog FileDialog ok_event13441473
Ref: 432013441473
Ref: library/dialog tkinter filedialog FileDialog quit13441560
Ref: 432113441560
Ref: library/dialog tkinter filedialog FileDialog set_filter13441645
Ref: 432213441645
Ref: library/dialog tkinter filedialog FileDialog set_selection13441717
Ref: 432313441717
Ref: library/dialog tkinter filedialog LoadFileDialog13441812
Ref: 432413441812
Ref: library/dialog tkinter filedialog LoadFileDialog ok_command13441977
Ref: 432513441977
Ref: library/dialog tkinter filedialog SaveFileDialog13442118
Ref: 432613442118
Ref: library/dialog tkinter filedialog SaveFileDialog ok_command13442285
Ref: 432713442285
Node: tkinter commondialog — Dialog window templates13442497
Ref: library/dialog module-tkinter commondialog13442651
Ref: f813442651
Ref: library/dialog tkinter-commondialog-dialog-window-templates13442651
Ref: 432813442651
Ref: library/dialog tkinter commondialog Dialog13443044
Ref: 42f013443044
Ref: library/dialog tkinter commondialog Dialog show13443110
Ref: 432913443110
Ref: tkinter commondialog — Dialog window templates-Footnote-113443321
Node: tkinter messagebox — Tkinter message prompts13443402
Ref: library/tkinter messagebox doc13443596
Ref: 432a13443596
Ref: library/tkinter messagebox module-tkinter messagebox13443596
Ref: fc13443596
Ref: library/tkinter messagebox tkinter-messagebox-tkinter-message-prompts13443596
Ref: 432b13443596
Ref: library/tkinter messagebox translation-repo13443596
Ref: 432c13443596
Ref: library/tkinter messagebox tkinter messagebox Message13444297
Ref: 433113444297
Ref: library/tkinter messagebox tkinter messagebox Message show13446439
Ref: 433613446439
Ref: library/tkinter messagebox tkinter messagebox showinfo13446744
Ref: 433713446744
Ref: library/tkinter messagebox tkinter messagebox showwarning13446957
Ref: 433813446957
Ref: library/tkinter messagebox tkinter messagebox showerror13447143
Ref: 433913447143
Ref: library/tkinter messagebox tkinter messagebox askquestion13447352
Ref: 433a13447352
Ref: library/tkinter messagebox tkinter messagebox askokcancel13447602
Ref: 433b13447602
Ref: library/tkinter messagebox tkinter messagebox askretrycancel13447867
Ref: 433c13447867
Ref: library/tkinter messagebox tkinter messagebox askyesno13448141
Ref: 433e13448141
Ref: library/tkinter messagebox tkinter messagebox askyesnocancel13448378
Ref: 433f13448378
Ref: library/tkinter messagebox messagebox-buttons13448671
Ref: 433213448671
Ref: library/tkinter messagebox tkinter messagebox ABORT13448699
Ref: 434013448699
Ref: library/tkinter messagebox tkinter messagebox RETRY13448745
Ref: 433d13448745
Ref: library/tkinter messagebox tkinter messagebox IGNORE13448791
Ref: 434113448791
Ref: library/tkinter messagebox tkinter messagebox OK13448839
Ref: 432d13448839
Ref: library/tkinter messagebox tkinter messagebox CANCEL13448879
Ref: 432e13448879
Ref: library/tkinter messagebox tkinter messagebox YES13448927
Ref: 432f13448927
Ref: library/tkinter messagebox tkinter messagebox NO13448969
Ref: 433013448969
Ref: library/tkinter messagebox messagebox-types13449008
Ref: 433513449008
Ref: library/tkinter messagebox tkinter messagebox ABORTRETRYIGNORE13449037
Ref: 434213449037
Ref: library/tkinter messagebox tkinter messagebox OKCANCEL13449331
Ref: 434313449331
Ref: library/tkinter messagebox tkinter messagebox RETRYCANCEL13449480
Ref: 434413449480
Ref: library/tkinter messagebox tkinter messagebox YESNO13449638
Ref: 434513449638
Ref: library/tkinter messagebox tkinter messagebox YESNOCANCEL13449778
Ref: 434613449778
Ref: library/tkinter messagebox messagebox-icons13449951
Ref: 433313449951
Ref: library/tkinter messagebox tkinter messagebox ERROR13449965
Ref: 434713449965
Ref: library/tkinter messagebox tkinter messagebox INFO13450011
Ref: 433413450011
Ref: library/tkinter messagebox tkinter messagebox QUESTION13450055
Ref: 434813450055
Ref: library/tkinter messagebox tkinter messagebox WARNING13450107
Ref: 434913450107
Ref: tkinter messagebox — Tkinter message prompts-Footnote-113450193
Node: tkinter scrolledtext — Scrolled Text Widget13450272
Ref: library/tkinter scrolledtext doc13450488
Ref: 434a13450488
Ref: library/tkinter scrolledtext module-tkinter scrolledtext13450488
Ref: fd13450488
Ref: library/tkinter scrolledtext tkinter-scrolledtext-scrolled-text-widget13450488
Ref: 434b13450488
Ref: library/tkinter scrolledtext translation-repo13450488
Ref: 434c13450488
Ref: library/tkinter scrolledtext tkinter scrolledtext ScrolledText13451399
Ref: 434d13451399
Ref: library/tkinter scrolledtext tkinter scrolledtext ScrolledText frame13451466
Ref: 434e13451466
Ref: library/tkinter scrolledtext tkinter scrolledtext ScrolledText vbar13451563
Ref: 434f13451563
Ref: tkinter scrolledtext — Scrolled Text Widget-Footnote-113451659
Node: tkinter dnd — Drag and drop support13451740
Ref: library/tkinter dnd doc13451943
Ref: 435013451943
Ref: library/tkinter dnd module-tkinter dnd13451943
Ref: f913451943
Ref: library/tkinter dnd tkinter-dnd-drag-and-drop-support13451943
Ref: 435113451943
Ref: library/tkinter dnd translation-repo13451943
Ref: 435213451943
Ref: library/tkinter dnd tkinter dnd DndHandler13453446
Ref: 435413453446
Ref: library/tkinter dnd tkinter dnd DndHandler cancel13453635
Ref: 435513453635
Ref: library/tkinter dnd tkinter dnd DndHandler finish13453718
Ref: 435613453718
Ref: library/tkinter dnd tkinter dnd DndHandler on_motion13453812
Ref: 435713453812
Ref: library/tkinter dnd tkinter dnd DndHandler on_release13453938
Ref: 435813453938
Ref: library/tkinter dnd tkinter dnd dnd_start13454044
Ref: 435313454044
Ref: tkinter dnd — Drag and drop support-Footnote-113454240
Node: tkinter ttk — Tk themed widgets13454311
Ref: library/tkinter ttk doc13454504
Ref: 435913454504
Ref: library/tkinter ttk module-tkinter ttk13454504
Ref: ff13454504
Ref: library/tkinter ttk tkinter-ttk-tk-themed-widgets13454504
Ref: 435a13454504
Ref: library/tkinter ttk translation-repo13454504
Ref: 435b13454504
Ref: tkinter ttk — Tk themed widgets-Footnote-113455427
Ref: tkinter ttk — Tk themed widgets-Footnote-213455498
Node: Using Ttk13455551
Ref: library/tkinter ttk using-ttk13455650
Ref: 435c13455650
Ref: Using Ttk-Footnote-113456806
Node: Ttk Widgets13456870
Ref: library/tkinter ttk ttk-widgets13456984
Ref: 435d13456984
Node: Widget13458092
Ref: library/tkinter ttk widget13458205
Ref: 436313458205
Node: Standard Options13458522
Ref: library/tkinter ttk standard-options13458615
Ref: 436413458615
Node: Scrollable Widget Options13460156
Ref: library/tkinter ttk scrollable-widget-options13460271
Ref: 436513460271
Node: Label Options13461304
Ref: library/tkinter ttk label-options13461424
Ref: 436613461424
Node: Compatibility Options13463758
Ref: library/tkinter ttk compatibility-options13463866
Ref: 436713463866
Node: Widget States13464351
Ref: library/tkinter ttk widget-states13464456
Ref: 436913464456
Node: ttk Widget13465952
Ref: library/tkinter ttk ttk-widget13466027
Ref: 436a13466027
Ref: library/tkinter ttk tkinter ttk Widget13466214
Ref: 436113466214
Ref: library/tkinter ttk tkinter ttk Widget identify13466246
Ref: 436b13466246
Ref: library/tkinter ttk tkinter ttk Widget instate13466489
Ref: 436c13466489
Ref: library/tkinter ttk tkinter ttk Widget state13466833
Ref: 436813466833
Node: Combobox13467221
Ref: library/tkinter ttk combobox13467330
Ref: 436d13467330
Node: Options13468025
Ref: library/tkinter ttk options13468100
Ref: 436e13468100
Node: Virtual events13470373
Ref: library/tkinter ttk virtual-events13470469
Ref: 436f13470469
Node: ttk Combobox13470649
Ref: library/tkinter ttk ttk-combobox13470729
Ref: 437013470729
Ref: library/tkinter ttk tkinter ttk Combobox13470776
Ref: 435e13470776
Ref: library/tkinter ttk tkinter ttk Combobox current13470810
Ref: 437113470810
Ref: library/tkinter ttk tkinter ttk Combobox get13471086
Ref: 437213471086
Ref: library/tkinter ttk tkinter ttk Combobox set13471165
Ref: 437313471165
Node: Spinbox13471249
Ref: library/tkinter ttk spinbox13471360
Ref: 437413471360
Node: Options<2>13472120
Ref: library/tkinter ttk id113472200
Ref: 437513472200
Node: Virtual events<2>13474584
Ref: library/tkinter ttk id213474684
Ref: 437613474684
Node: ttk Spinbox13474892
Ref: library/tkinter ttk ttk-spinbox13474973
Ref: 437713474973
Ref: library/tkinter ttk tkinter ttk Spinbox13475018
Ref: d8f13475018
Ref: library/tkinter ttk tkinter ttk Spinbox get13475051
Ref: 437813475051
Ref: library/tkinter ttk tkinter ttk Spinbox set13475129
Ref: 437913475129
Node: Notebook13475212
Ref: library/tkinter ttk notebook13475326
Ref: 437a13475326
Node: Options<3>13475686
Ref: library/tkinter ttk id313475761
Ref: 437b13475761
Node: Tab Options13476836
Ref: library/tkinter ttk tab-options13476935
Ref: 437c13476935
Node: Tab Identifiers13478802
Ref: library/tkinter ttk tab-identifiers13478905
Ref: 437e13478905
Node: Virtual Events13479433
Ref: library/tkinter ttk id413479537
Ref: 438013479537
Node: ttk Notebook13479681
Ref: library/tkinter ttk ttk-notebook13479761
Ref: 438113479761
Ref: library/tkinter ttk tkinter ttk Notebook13479808
Ref: 435f13479808
Ref: library/tkinter ttk tkinter ttk Notebook add13479842
Ref: 438213479842
Ref: library/tkinter ttk tkinter ttk Notebook forget13480127
Ref: 438313480127
Ref: library/tkinter ttk tkinter ttk Notebook hide13480265
Ref: 438413480265
Ref: library/tkinter ttk tkinter ttk Notebook identify13480575
Ref: 438513480575
Ref: library/tkinter ttk tkinter ttk Notebook index13480717
Ref: 437f13480717
Ref: library/tkinter ttk tkinter ttk Notebook insert13480894
Ref: 438613480894
Ref: library/tkinter ttk tkinter ttk Notebook select13481277
Ref: 438713481277
Ref: library/tkinter ttk tkinter ttk Notebook tab13481591
Ref: 438813481591
Ref: library/tkinter ttk tkinter ttk Notebook tabs13481937
Ref: 438913481937
Ref: library/tkinter ttk tkinter ttk Notebook enable_traversal13482025
Ref: 437d13482025
Node: Progressbar13482876
Ref: library/tkinter ttk progressbar13482992
Ref: 438a13482992
Node: Options<4>13483433
Ref: library/tkinter ttk id513483515
Ref: 438b13483515
Node: ttk Progressbar13485201
Ref: library/tkinter ttk ttk-progressbar13485283
Ref: 438c13485283
Ref: library/tkinter ttk tkinter ttk Progressbar13485336
Ref: 436013485336
Ref: library/tkinter ttk tkinter ttk Progressbar start13485373
Ref: 438d13485373
Ref: library/tkinter ttk tkinter ttk Progressbar step13485641
Ref: 438e13485641
Ref: library/tkinter ttk tkinter ttk Progressbar stop13485788
Ref: 438f13485788
Node: Separator13485973
Ref: library/tkinter ttk separator13486089
Ref: 439013486089
Node: Options<5>13486319
Ref: library/tkinter ttk id613486375
Ref: 439113486375
Node: Sizegrip13486725
Ref: library/tkinter ttk sizegrip13486838
Ref: 439213486838
Node: Platform-specific notes13487188
Ref: library/tkinter ttk platform-specific-notes13487269
Ref: 439313487269
Node: Bugs13487525
Ref: library/tkinter ttk bugs13487606
Ref: 439413487606
Node: Treeview13487877
Ref: library/tkinter ttk treeview13487992
Ref: 439513487992
Node: Options<6>13489350
Ref: library/tkinter ttk id713489426
Ref: 439913489426
Node: Item Options13491824
Ref: library/tkinter ttk item-options13491920
Ref: 439a13491920
Node: Tag Options13492976
Ref: library/tkinter ttk tag-options13493080
Ref: 439b13493080
Node: Column Identifiers13493730
Ref: library/tkinter ttk column-identifiers13493839
Ref: 439613493839
Node: Virtual Events<2>13494709
Ref: library/tkinter ttk id813494819
Ref: 439c13494819
Node: ttk Treeview13495651
Ref: library/tkinter ttk ttk-treeview13495734
Ref: 439e13495734
Ref: library/tkinter ttk tkinter ttk Treeview13495781
Ref: c8913495781
Ref: library/tkinter ttk tkinter ttk Treeview bbox13495815
Ref: 439f13495815
Ref: library/tkinter ttk tkinter ttk Treeview get_children13496252
Ref: 43a013496252
Ref: library/tkinter ttk tkinter ttk Treeview set_children13496418
Ref: 43a113496418
Ref: library/tkinter ttk tkinter ttk Treeview column13496810
Ref: 43a213496810
Ref: library/tkinter ttk tkinter ttk Treeview delete13498053
Ref: 43a313498053
Ref: library/tkinter ttk tkinter ttk Treeview detach13498199
Ref: 43a413498199
Ref: library/tkinter ttk tkinter ttk Treeview exists13498510
Ref: 43a513498510
Ref: library/tkinter ttk tkinter ttk Treeview focus13498620
Ref: 439d13498620
Ref: library/tkinter ttk tkinter ttk Treeview heading13498813
Ref: 43a613498813
Ref: library/tkinter ttk tkinter ttk Treeview identify13499802
Ref: 43a713499802
Ref: library/tkinter ttk tkinter ttk Treeview identify_row13500039
Ref: 43a813500039
Ref: library/tkinter ttk tkinter ttk Treeview identify_column13500134
Ref: 43a913500134
Ref: library/tkinter ttk tkinter ttk Treeview identify_region13500295
Ref: 43aa13500295
Ref: library/tkinter ttk tkinter ttk Treeview identify_element13500931
Ref: 43ab13500931
Ref: library/tkinter ttk tkinter ttk Treeview index13501059
Ref: 43ac13501059
Ref: library/tkinter ttk tkinter ttk Treeview insert13501187
Ref: 43ad13501187
Ref: library/tkinter ttk tkinter ttk Treeview item13502083
Ref: 43ae13502083
Ref: library/tkinter ttk tkinter ttk Treeview move13502461
Ref: 43af13502461
Ref: library/tkinter ttk tkinter ttk Treeview next13502899
Ref: 43b013502899
Ref: library/tkinter ttk tkinter ttk Treeview parent13503054
Ref: 43b113503054
Ref: library/tkinter ttk tkinter ttk Treeview prev13503205
Ref: 43b213503205
Ref: library/tkinter ttk tkinter ttk Treeview reattach13503365
Ref: 43b313503365
Ref: library/tkinter ttk tkinter ttk Treeview see13503467
Ref: 43b413503467
Ref: library/tkinter ttk tkinter ttk Treeview selection13503723
Ref: c8813503723
Ref: library/tkinter ttk tkinter ttk Treeview selection_set13503976
Ref: c8a13503976
Ref: library/tkinter ttk tkinter ttk Treeview selection_add13504186
Ref: 43b513504186
Ref: library/tkinter ttk tkinter ttk Treeview selection_remove13504391
Ref: 43b613504391
Ref: library/tkinter ttk tkinter ttk Treeview selection_toggle13504604
Ref: 43b713504604
Ref: library/tkinter ttk tkinter ttk Treeview set13504834
Ref: 43b813504834
Ref: library/tkinter ttk tkinter ttk Treeview tag_bind13505199
Ref: 43b913505199
Ref: library/tkinter ttk tkinter ttk Treeview tag_configure13505469
Ref: 43ba13505469
Ref: library/tkinter ttk tkinter ttk Treeview tag_has13505898
Ref: 43bb13505898
Ref: library/tkinter ttk tkinter ttk Treeview xview13506183
Ref: 439713506183
Ref: library/tkinter ttk tkinter ttk Treeview yview13506279
Ref: 439813506279
Node: Ttk Styling13506373
Ref: library/tkinter ttk ttk-styling13506471
Ref: 43bc13506471
Ref: library/tkinter ttk ttkstyling13506471
Ref: 436213506471
Ref: library/tkinter ttk tkinter ttk Style13507067
Ref: 56013507067
Ref: library/tkinter ttk tkinter ttk Style configure13507157
Ref: 43bd13507157
Ref: library/tkinter ttk tkinter ttk Style map13507884
Ref: 1cce13507884
Ref: library/tkinter ttk tkinter ttk Style lookup13509149
Ref: 43be13509149
Ref: library/tkinter ttk tkinter ttk Style layout13509670
Ref: 43bf13509670
Ref: library/tkinter ttk tkinter ttk Style element_create13510982
Ref: 55f13510982
Ref: library/tkinter ttk tkinter ttk Style element_names13516338
Ref: 43c113516338
Ref: library/tkinter ttk tkinter ttk Style element_options13516443
Ref: 43c213516443
Ref: library/tkinter ttk tkinter ttk Style theme_create13516549
Ref: 43c313516549
Ref: library/tkinter ttk tkinter ttk Style theme_settings13516962
Ref: 43c413516962
Ref: library/tkinter ttk tkinter ttk Style theme_names13518438
Ref: 43c513518438
Ref: library/tkinter ttk tkinter ttk Style theme_use13518518
Ref: 43c613518518
Ref: Ttk Styling-Footnote-113518815
Node: Layouts13518877
Ref: library/tkinter ttk layouts13518932
Ref: 43c013518932
Ref: library/tkinter ttk layout13520004
Ref: 43c713520004
Node: IDLE — Python editor and shell<2>13520005
Ref: library/idle doc13520187
Ref: 43c813520187
Ref: library/idle idle13520187
Ref: 121713520187
Ref: library/idle idle-python-editor-and-shell13520187
Ref: 43c913520187
Ref: library/idle translation-repo13520187
Ref: 43ca13520187
Ref: IDLE — Python editor and shell<2>-Footnote-113521568
Node: Menus13521633
Ref: library/idle menus13521741
Ref: 43cb13521741
Node: File menu Shell and Editor13523023
Ref: library/idle file-menu-shell-and-editor13523126
Ref: 43cc13523126
Node: Edit menu Shell and Editor13524976
Ref: library/idle edit-menu-shell-and-editor13525118
Ref: 43cd13525118
Node: Format menu Editor window only13526859
Ref: library/idle format-menu13527002
Ref: 43d013527002
Ref: library/idle format-menu-editor-window-only13527002
Ref: 43d113527002
Node: Run menu Editor window only13528325
Ref: library/idle run-menu-editor-window-only13528470
Ref: 43d313528470
Ref: library/idle run-module13528549
Ref: 43d413528549
Ref: library/idle run-custom13529041
Ref: 43d613529041
Ref: library/idle check-module13529301
Ref: 43d513529301
Ref: library/idle python-shell13529645
Ref: 43d713529645
Node: Shell menu Shell window only13529707
Ref: library/idle shell-menu-shell-window-only13529850
Ref: 43d813529850
Node: Debug menu Shell window only13530367
Ref: library/idle debug-menu-shell-window-only13530512
Ref: 43d913530512
Node: Options menu Shell and Editor13531468
Ref: library/idle options-menu-shell-and-editor13531613
Ref: 43da13531613
Node: Window menu Shell and Editor13533230
Ref: library/idle window-menu-shell-and-editor13533373
Ref: 43dd13533373
Node: Help menu Shell and Editor13533565
Ref: library/idle help-menu-shell-and-editor13533692
Ref: 43de13533692
Node: Context menus13534412
Ref: library/idle context-menus13534502
Ref: 43e013534502
Node: Editing and Navigation13535676
Ref: library/idle editing-and-navigation13535819
Ref: 43e113535819
Ref: library/idle id113535819
Ref: 43e213535819
Node: Editor windows13536077
Ref: library/idle editor-windows13536171
Ref: 43e313536171
Node: Key bindings13536793
Ref: library/idle key-bindings13536917
Ref: 43e413536917
Node: Automatic indentation13538336
Ref: library/idle automatic-indentation13538464
Ref: 43e513538464
Node: Search and Replace13539044
Ref: library/idle search-and-replace13539171
Ref: 43e613539171
Node: Completions13539505
Ref: library/idle completions13539619
Ref: 43ce13539619
Ref: library/idle id213539619
Ref: 43e713539619
Node: Calltips13542269
Ref: library/idle calltips13542377
Ref: 43cf13542377
Ref: library/idle id313542377
Ref: 43e813542377
Node: Format block13544001
Ref: library/idle format-block13544110
Ref: 43d213544110
Ref: library/idle id413544110
Ref: 43e913544110
Node: Code Context13544633
Ref: library/idle code-context13544746
Ref: 43dc13544746
Ref: library/idle id513544746
Ref: 43ea13544746
Node: Shell window13545634
Ref: library/idle shell-window13545746
Ref: 43eb13545746
Node: Text colors13547425
Ref: library/idle text-colors13547516
Ref: 43ec13547516
Node: Startup and Code Execution13548549
Ref: library/idle startup-and-code-execution13548707
Ref: 43ed13548707
Node: Command-line usage<5>13549860
Ref: library/idle command-line-usage13549968
Ref: 43ee13549968
Ref: library/idle idlelib-cli13549968
Ref: 43ef13549968
Ref: library/idle cmdoption-idle-c13550199
Ref: 43f013550199
Ref: library/idle cmdoption-idle-d13550411
Ref: 43f113550411
Ref: library/idle cmdoption-idle-e13550480
Ref: 43f213550480
Ref: library/idle cmdoption-idle-h13550525
Ref: 43f313550525
Ref: library/idle cmdoption-idle-i13550613
Ref: 43f413550613
Ref: library/idle cmdoption-idle-r13550656
Ref: 43f513550656
Ref: library/idle cmdoption-idle-s13550729
Ref: 43f613550729
Ref: library/idle cmdoption-idle-t13550904
Ref: 43f713550904
Ref: library/idle cmdoption-idle-013550969
Ref: 43f813550969
Node: Startup failure13551556
Ref: library/idle startup-failure13551690
Ref: 43f913551690
Node: Running user code13554877
Ref: library/idle running-user-code13555010
Ref: 43fa13555010
Node: User output in Shell13557794
Ref: library/idle user-output-in-shell13557943
Ref: 43fb13557943
Node: Developing tkinter applications13561029
Ref: library/idle developing-tkinter-applications13561189
Ref: 43fc13561189
Node: Running without a subprocess13562438
Ref: library/idle running-without-a-subprocess13562569
Ref: 43fd13562569
Node: Help and Preferences13563951
Ref: library/idle help-and-preferences13564133
Ref: 43fe13564133
Node: Help sources13564280
Ref: library/idle help-sources13564377
Ref: 43df13564377
Ref: library/idle id613564377
Ref: 43ff13564377
Node: Setting preferences13565243
Ref: library/idle preferences13565362
Ref: 43db13565362
Ref: library/idle setting-preferences13565362
Ref: 440013565362
Node: IDLE on macOS13566371
Ref: library/idle idle-on-macos13566488
Ref: 440113566488
Node: Extensions13566751
Ref: library/idle extensions13566840
Ref: 440213566840
Node: idlelib — implementation of IDLE application13567191
Ref: library/idle idlelib-implementation-of-idle-application13567338
Ref: 440313567338
Ref: library/idle module-idlelib13567338
Ref: 7713567338
Ref: idlelib — implementation of IDLE application-Footnote-113568046
Ref: idlelib — implementation of IDLE application-Footnote-213568110
Node: turtle — Turtle graphics13568152
Ref: library/turtle doc13568292
Ref: 440413568292
Ref: library/turtle module-turtle13568292
Ref: 10713568292
Ref: library/turtle translation-repo13568292
Ref: 440513568292
Ref: library/turtle turtle-turtle-graphics13568292
Ref: 440613568292
Ref: turtle — Turtle graphics-Footnote-113568975
Node: Introduction<11>13569041
Ref: library/turtle introduction13569140
Ref: 440713569140
Ref: Introduction<11>-Footnote-113569650
Node: Get started13569703
Ref: library/turtle get-started13569822
Ref: 440813569822
Node: Tutorial<4>13571008
Ref: library/turtle turtle-tutorial13571120
Ref: 440913571120
Ref: library/turtle tutorial13571120
Ref: 440a13571120
Node: Starting a turtle environment13571355
Ref: library/turtle starting-a-turtle-environment13571454
Ref: 440b13571454
Node: Basic drawing13571769
Ref: library/turtle basic-drawing13571904
Ref: 440c13571904
Node: Pen control13572545
Ref: library/turtle pen-control13572638
Ref: 440d13572638
Node: The turtle’s position13572968
Ref: library/turtle the-turtle-s-position13573061
Ref: 440e13573061
Node: Making algorithmic patterns13573506
Ref: library/turtle making-algorithmic-patterns13573603
Ref: 440f13573603
Node: How to…13574582
Ref: library/turtle how-to13574708
Ref: 441013574708
Ref: library/turtle turtle-how-to13574708
Ref: 441113574708
Node: Get started as quickly as possible13575015
Ref: library/turtle get-started-as-quickly-as-possible13575139
Ref: 441213575139
Ref: library/turtle note13575897
Ref: 441313575897
Node: Automatically begin and end filling13576169
Ref: library/turtle automatically-begin-and-end-filling13576333
Ref: 441413576333
Node: Use the turtle module namespace13576910
Ref: library/turtle use-the-turtle-module-namespace13577071
Ref: 441713577071
Node: Use turtle graphics in a script13577739
Ref: library/turtle use-turtle-graphics-in-a-script13577900
Ref: 441813577900
Node: Use object-oriented turtle graphics13578596
Ref: library/turtle use-object-oriented-turtle-graphics13578717
Ref: 441913578717
Node: Turtle graphics reference13579953
Ref: library/turtle turtle-graphics-reference13580123
Ref: 441c13580123
Node: Turtle methods13580443
Ref: library/turtle turtle-methods13580558
Ref: 441d13580558
Node: Methods of TurtleScreen/Screen13583637
Ref: library/turtle methods-of-turtlescreen-screen13583752
Ref: 446813583752
Node: Methods of RawTurtle/Turtle and corresponding functions13585143
Ref: library/turtle methods-of-rawturtle-turtle-and-corresponding-functions13585362
Ref: 448713585362
Node: Turtle motion13585778
Ref: library/turtle turtle-motion13585913
Ref: 448813585913
Ref: library/turtle turtle forward13585964
Ref: 35f513585964
Ref: library/turtle turtle fd13586004
Ref: 441e13586004
Ref: library/turtle turtle back13586441
Ref: 442113586441
Ref: library/turtle turtle bk13586478
Ref: 442013586478
Ref: library/turtle turtle backward13586513
Ref: 441f13586513
Ref: library/turtle turtle right13586884
Ref: 442213586884
Ref: library/turtle turtle rt13586919
Ref: 442313586919
Ref: library/turtle turtle left13587384
Ref: 442413587384
Ref: library/turtle turtle lt13587418
Ref: 442513587418
Ref: library/turtle turtle goto13587880
Ref: 442613587880
Ref: library/turtle turtle setpos13587918
Ref: 442713587918
Ref: library/turtle turtle setposition13587958
Ref: 442813587958
Ref: library/turtle turtle teleport13588712
Ref: 1a7f13588712
Ref: library/turtle turtle setx13589723
Ref: 442913589723
Ref: library/turtle turtle sety13590046
Ref: 442a13590046
Ref: library/turtle turtle setheading13590368
Ref: 442b13590368
Ref: library/turtle turtle seth13590411
Ref: 442c13590411
Ref: library/turtle turtle home13591226
Ref: 442d13591226
Ref: library/turtle turtle circle13591653
Ref: 442e13591653
Ref: library/turtle turtle dot13593037
Ref: 442f13593037
Ref: library/turtle turtle stamp13593739
Ref: 443013593739
Ref: library/turtle turtle clearstamp13594076
Ref: 443113594076
Ref: library/turtle turtle clearstamps13594585
Ref: 443213594585
Ref: library/turtle turtle undo13595095
Ref: 443313595095
Ref: library/turtle turtle speed13595420
Ref: 443413595420
Node: Tell Turtle’s state13596408
Ref: library/turtle tell-turtle-s-state13596576
Ref: 448a13596576
Ref: library/turtle turtle position13596641
Ref: 443513596641
Ref: library/turtle turtle pos13596674
Ref: 443613596674
Ref: library/turtle turtle towards13596846
Ref: 443713596846
Ref: library/turtle turtle xcor13597404
Ref: 443813597404
Ref: library/turtle turtle ycor13597684
Ref: 443913597684
Ref: library/turtle turtle heading13597971
Ref: 443a13597971
Ref: library/turtle turtle distance13598219
Ref: 443b13598219
Node: Settings for measurement13598807
Ref: library/turtle settings-for-measurement13598976
Ref: 448b13598976
Ref: library/turtle turtle degrees13599049
Ref: 443c13599049
Ref: library/turtle turtle radians13599686
Ref: 443d13599686
Node: Pen control<2>13600011
Ref: library/turtle id113600171
Ref: 448c13600171
Node: Drawing state13600301
Ref: library/turtle drawing-state13600387
Ref: 448d13600387
Ref: library/turtle turtle pendown13600438
Ref: 443e13600438
Ref: library/turtle turtle pd13600470
Ref: 443f13600470
Ref: library/turtle turtle down13600497
Ref: 444013600497
Ref: library/turtle turtle penup13600576
Ref: 444113600576
Ref: library/turtle turtle pu13600606
Ref: 444213600606
Ref: library/turtle turtle up13600633
Ref: 444313600633
Ref: library/turtle turtle pensize13600711
Ref: 444413600711
Ref: library/turtle turtle width13600753
Ref: 444513600753
Ref: library/turtle turtle pen13601212
Ref: 444613601212
Ref: library/turtle turtle isdown13603093
Ref: 444713603093
Node: Color control13603343
Ref: library/turtle color-control13603445
Ref: 448e13603445
Ref: library/turtle turtle pencolor13603496
Ref: 444913603496
Ref: library/turtle turtle fillcolor13605189
Ref: 444a13605189
Ref: library/turtle turtle color13606788
Ref: 444813606788
Node: Filling13608114
Ref: library/turtle filling13608223
Ref: 448f13608223
Ref: library/turtle turtle filling13608262
Ref: 444b13608262
Ref: library/turtle turtle fill13608521
Ref: 2a313608521
Ref: library/turtle turtle begin_fill13609064
Ref: 441513609064
Ref: library/turtle turtle end_fill13609161
Ref: 441613609161
Node: More drawing control13609708
Ref: library/turtle more-drawing-control13609795
Ref: 449013609795
Ref: library/turtle turtle reset13609860
Ref: 444c13609860
Ref: library/turtle turtle clear13610308
Ref: 444d13610308
Ref: library/turtle turtle write13610512
Ref: 444e13610512
Node: Turtle state13611279
Ref: library/turtle turtle-state13611427
Ref: 449113611427
Node: Visibility13611516
Ref: library/turtle visibility13611594
Ref: 449213611594
Ref: library/turtle turtle hideturtle13611639
Ref: 445113611639
Ref: library/turtle turtle ht13611674
Ref: 445213611674
Ref: library/turtle turtle showturtle13611931
Ref: 444f13611931
Ref: library/turtle turtle st13611966
Ref: 445013611966
Ref: library/turtle turtle isvisible13612060
Ref: 445313612060
Node: Appearance13612339
Ref: library/turtle appearance13612417
Ref: 449313612417
Ref: library/turtle turtle shape13612462
Ref: 445413612462
Ref: library/turtle turtle resizemode13613122
Ref: 445513613122
Ref: library/turtle turtle shapesize13614074
Ref: 445613614074
Ref: library/turtle turtle turtlesize13614166
Ref: 445713614166
Ref: library/turtle turtle shearfactor13615146
Ref: 445813615146
Ref: library/turtle turtle tilt13615809
Ref: 445913615809
Ref: library/turtle turtle tiltangle13616248
Ref: 93013616248
Ref: library/turtle turtle shapetransform13616969
Ref: 445a13616969
Ref: library/turtle turtle get_shapepoly13618000
Ref: 445b13618000
Node: Using events13618371
Ref: library/turtle using-events13618527
Ref: 449413618527
Ref: library/turtle turtle onrelease13619428
Ref: 445d13619428
Ref: library/turtle turtle ondrag13620438
Ref: 445e13620438
Node: Special Turtle methods13621312
Ref: library/turtle special-turtle-methods13621471
Ref: 449513621471
Ref: library/turtle turtle poly13621540
Ref: 2a413621540
Ref: library/turtle turtle begin_poly13621883
Ref: 445f13621883
Ref: library/turtle turtle end_poly13622026
Ref: 446013622026
Ref: library/turtle turtle get_poly13622217
Ref: 446113622217
Ref: library/turtle turtle clone13622619
Ref: 446213622619
Ref: library/turtle turtle getturtle13622816
Ref: 446313622816
Ref: library/turtle turtle getpen13622850
Ref: 446413622850
Ref: library/turtle turtle getscreen13623116
Ref: 446513623116
Ref: library/turtle turtle setundobuffer13623422
Ref: 446613623422
Ref: library/turtle turtle undobufferentries13623858
Ref: 446713623858
Node: Compound shapes13624018
Ref: library/turtle compound-shapes13624156
Ref: 449713624156
Ref: library/turtle compoundshapes13624156
Ref: 449813624156
Node: Methods of TurtleScreen/Screen and corresponding functions13625190
Ref: library/turtle methods-of-turtlescreen-screen-and-corresponding-functions13625398
Ref: 449b13625398
Node: Window control13625880
Ref: library/turtle window-control13626015
Ref: 449c13626015
Ref: library/turtle turtle bgcolor13626068
Ref: 446913626068
Ref: library/turtle turtle bgpic13627392
Ref: 446a13627392
Ref: library/turtle turtle clearscreen13628295
Ref: 446b13628295
Ref: library/turtle turtle resetscreen13628804
Ref: 446c13628804
Ref: library/turtle turtle screensize13628903
Ref: 446d13628903
Ref: library/turtle turtle setworldcoordinates13629811
Ref: 446e13629811
Node: Animation control13630788
Ref: library/turtle animation-control13630951
Ref: 449d13630951
Ref: library/turtle turtle no_animation13631010
Ref: 2a513631010
Ref: library/turtle turtle delay13631414
Ref: 446f13631414
Ref: library/turtle turtle tracer13631852
Ref: 447013631852
Ref: library/turtle turtle update13632552
Ref: 447113632552
Node: Using screen events13632724
Ref: library/turtle using-screen-events13632886
Ref: 449e13632886
Ref: library/turtle turtle listen13632949
Ref: 447213632949
Ref: library/turtle turtle onkey13633184
Ref: 447313633184
Ref: library/turtle turtle onkeyrelease13633222
Ref: 447413633222
Ref: library/turtle turtle onkeypress13633839
Ref: 447513633839
Ref: library/turtle turtle onclick13634437
Ref: 445c13634437
Ref: library/turtle turtle onscreenclick13634489
Ref: 447613634489
Ref: library/turtle turtle ontimer13635676
Ref: 447713635676
Ref: library/turtle turtle mainloop13636159
Ref: 447813636159
Ref: library/turtle turtle done13636192
Ref: 447913636192
Node: Input methods13636518
Ref: library/turtle input-methods13636691
Ref: 449f13636691
Ref: library/turtle turtle textinput13636742
Ref: 1c6213636742
Ref: library/turtle turtle numinput13637195
Ref: 1c6313637195
Node: Settings and special methods13638117
Ref: library/turtle settings-and-special-methods13638329
Ref: 44a013638329
Ref: library/turtle turtle mode13638410
Ref: 447a13638410
Ref: library/turtle turtle colormode13639614
Ref: 447b13639614
Ref: library/turtle turtle getcanvas13640253
Ref: 447c13640253
Ref: library/turtle turtle getshapes13640504
Ref: 447d13640504
Ref: library/turtle turtle register_shape13640698
Ref: 447e13640698
Ref: library/turtle turtle addshape13640753
Ref: 447f13640753
Ref: library/turtle turtle turtles13642272
Ref: 448013642272
Ref: library/turtle turtle window_height13642438
Ref: 448113642438
Ref: library/turtle turtle window_width13642575
Ref: 448213642575
Node: Methods specific to Screen not inherited from TurtleScreen13642709
Ref: library/turtle methods-specific-to-screen-not-inherited-from-turtlescreen13642899
Ref: 44a113642899
Ref: library/turtle screenspecific13642899
Ref: 44a213642899
Ref: library/turtle turtle bye13643042
Ref: 448313643042
Ref: library/turtle turtle exitonclick13643109
Ref: 448413643109
Ref: library/turtle turtle save13643547
Ref: 195813643547
Ref: library/turtle turtle setup13644133
Ref: 448513644133
Ref: library/turtle turtle title13645452
Ref: 448613645452
Node: Public classes13645717
Ref: library/turtle public-classes13645884
Ref: 44a313645884
Ref: library/turtle turtle RawTurtle13645937
Ref: 44a413645937
Ref: library/turtle turtle RawPen13645975
Ref: 44a513645975
Ref: library/turtle turtle Turtle13646244
Ref: 44a713646244
Ref: library/turtle turtle TurtleScreen13646437
Ref: 449613646437
Ref: library/turtle turtle Screen13646632
Ref: 441b13646632
Ref: library/turtle turtle ScrolledCanvas13646728
Ref: 44a613646728
Ref: library/turtle turtle Shape13647023
Ref: 449913647023
Ref: library/turtle turtle Shape addcomponent13647819
Ref: 449a13647819
Ref: library/turtle turtle Vec2D13648418
Ref: 448913648418
Node: Explanation<2>13648971
Ref: library/turtle explanation13649102
Ref: 44a813649102
Ref: library/turtle turtle-explanation13649102
Ref: 441a13649102
Node: Help and configuration13650536
Ref: library/turtle help-and-configuration13650680
Ref: 44a913650680
Node: How to use help13650874
Ref: library/turtle how-to-use-help13651007
Ref: 44aa13651007
Node: Translation of docstrings into different languages13653327
Ref: library/turtle translation-of-docstrings-into-different-languages13653504
Ref: 44ab13653504
Ref: library/turtle turtle write_docstringdict13653810
Ref: 44ac13653810
Node: How to configure Screen and Turtles13654848
Ref: library/turtle how-to-configure-screen-and-turtles13655001
Ref: 44ad13655001
Node: turtledemo — Demo scripts13657808
Ref: library/turtle module-turtledemo13657962
Ref: 10813657962
Ref: library/turtle turtledemo-demo-scripts13657962
Ref: 44ae13657962
Node: Changes since Python 2 613664588
Ref: library/turtle changes-since-python-2-613664744
Ref: 44af13664744
Node: Changes since Python 3 013665784
Ref: library/turtle changes-since-python-3-013665904
Ref: 44b013665904
Node: Development Tools13667024
Ref: library/development doc13667179
Ref: 44b113667179
Ref: library/development development13667179
Ref: 44b213667179
Ref: library/development development-tools13667179
Ref: 44b313667179
Ref: library/development translation-repo13667179
Ref: 44b413667179
Node: typing — Support for type hints13669109
Ref: library/typing doc13669261
Ref: 44b513669261
Ref: library/typing typing-support-for-type-hints13669261
Ref: 44b613669261
Ref: library/typing module-typing13669350
Ref: 10a13669350
Ref: typing — Support for type hints-Footnote-113671486
Ref: typing — Support for type hints-Footnote-213671552
Ref: typing — Support for type hints-Footnote-313671604
Ref: typing — Support for type hints-Footnote-413671671
Ref: typing — Support for type hints-Footnote-513671728
Node: Specification for the Python Type System13671773
Ref: library/typing relevant-peps13671904
Ref: 44b713671904
Ref: library/typing specification-for-the-python-type-system13671904
Ref: 44b813671904
Ref: Specification for the Python Type System-Footnote-113672169
Node: Type aliases13672229
Ref: library/typing id213672376
Ref: 44b913672376
Ref: library/typing type-aliases13672376
Ref: 68413672376
Node: NewType13673881
Ref: library/typing distinct13674015
Ref: 44ba13674015
Ref: library/typing newtype13674015
Ref: 44bb13674015
Ref: NewType-Footnote-113677122
Node: Annotating callable objects13677164
Ref: library/typing annotating-callable-objects13677294
Ref: 44bc13677294
Ref: library/typing annotating-callables13677294
Ref: 26b213677294
Ref: Annotating callable objects-Footnote-113680407
Node: Generics13680449
Ref: library/typing generics13680589
Ref: 23af13680589
Ref: library/typing id313680589
Ref: 44be13680589
Node: Annotating tuples13681899
Ref: library/typing annotating-tuples13682037
Ref: 26b313682037
Ref: library/typing id413682037
Ref: 44bf13682037
Node: The type of class objects13684416
Ref: library/typing the-type-of-class-objects13684582
Ref: 44c013684582
Ref: library/typing type-of-class-objects13684582
Ref: 44c113684582
Node: Annotating generators and coroutines13686261
Ref: library/typing annotating-generators-and-coroutines13686436
Ref: 298013686436
Ref: library/typing id513686436
Ref: 44c313686436
Node: User-defined generic types13689003
Ref: library/typing user-defined-generic-types13689165
Ref: 44c413689165
Ref: library/typing user-defined-generics13689165
Ref: 6f713689165
Ref: User-defined generic types-Footnote-113695095
Node: The Any type13695137
Ref: library/typing the-any-type13695294
Ref: 44c613695294
Node: Nominal vs structural subtyping13697929
Ref: library/typing nominal-vs-structural-subtyping13698078
Ref: 44c713698078
Ref: Nominal vs structural subtyping-Footnote-113699754
Ref: Nominal vs structural subtyping-Footnote-213699796
Ref: Nominal vs structural subtyping-Footnote-313699838
Node: Module contents<3>13699880
Ref: library/typing module-contents13700055
Ref: 44c813700055
Node: Special typing primitives13700392
Ref: library/typing special-typing-primitives13700493
Ref: 44c913700493
Node: Special types13700685
Ref: library/typing special-types13700782
Ref: 44ca13700782
Ref: library/typing typing Any13700925
Ref: 8bc13700925
Ref: library/typing typing AnyStr13701327
Ref: 5ac13701327
Ref: library/typing typing LiteralString13703140
Ref: 7e713703140
Ref: library/typing typing Never13704364
Ref: 8b813704364
Ref: library/typing typing NoReturn13704387
Ref: 44cc13704387
Ref: library/typing typing Self13705625
Ref: 7e413705625
Ref: library/typing typing TypeAlias13707556
Ref: 9ce13707556
Ref: Special types-Footnote-113709187
Ref: Special types-Footnote-213709229
Ref: Special types-Footnote-313709271
Ref: Special types-Footnote-413709321
Ref: Special types-Footnote-513709363
Node: Special forms13709405
Ref: library/typing special-forms13709550
Ref: 44cd13709550
Ref: library/typing typing Union13709720
Ref: 2a813709720
Ref: library/typing typing Optional13711586
Ref: 8c313711586
Ref: library/typing typing Concatenate13712403
Ref: 9c913712403
Ref: library/typing typing Literal13714801
Ref: a5713714801
Ref: library/typing typing ClassVar13716899
Ref: 56d13716899
Ref: library/typing typing Final13718104
Ref: 56e13718104
Ref: library/typing typing Required13718856
Ref: 7e113718856
Ref: library/typing typing NotRequired13719124
Ref: 7e213719124
Ref: library/typing typing ReadOnly13719344
Ref: 48b13719344
Ref: library/typing typing Annotated13719873
Ref: b3913719873
Ref: library/typing typing TypeIs13725640
Ref: 48c13725640
Ref: library/typing typing TypeGuard13729444
Ref: 48d13729444
Ref: library/typing typing Unpack13731865
Ref: 198e13731865
Ref: Special forms-Footnote-113733572
Ref: Special forms-Footnote-213733614
Ref: Special forms-Footnote-313733656
Ref: Special forms-Footnote-413733698
Ref: Special forms-Footnote-513733740
Ref: Special forms-Footnote-613733782
Ref: Special forms-Footnote-713733824
Ref: Special forms-Footnote-813733866
Ref: Special forms-Footnote-913733908
Ref: Special forms-Footnote-1013733950
Ref: Special forms-Footnote-1113733993
Node: Building generic types and type aliases13734036
Ref: library/typing building-generic-types-and-type-aliases13734192
Ref: 44cf13734192
Ref: library/typing typing Generic13734703
Ref: 179e13734703
Ref: library/typing typevar13735909
Ref: 44c513735909
Ref: library/typing typing TypeVar13735909
Ref: 48713735909
Ref: library/typing typing-constrained-typevar13739434
Ref: 44cb13739434
Ref: library/typing typing TypeVar __name__13740052
Ref: 44d013740052
Ref: library/typing typing TypeVar __covariant__13740124
Ref: 44d113740124
Ref: library/typing typing TypeVar __contravariant__13740232
Ref: 44d213740232
Ref: library/typing typing TypeVar __infer_variance__13740358
Ref: 44d313740358
Ref: library/typing typing TypeVar __bound__13740529
Ref: 44d413740529
Ref: library/typing typing TypeVar evaluate_bound13740890
Ref: 44d513740890
Ref: library/typing typing TypeVar __constraints__13741415
Ref: 44d813741415
Ref: library/typing typing TypeVar evaluate_constraints13741818
Ref: 44d913741818
Ref: library/typing typing TypeVar __default__13742361
Ref: 44da13742361
Ref: library/typing typing TypeVar evaluate_default13742543
Ref: 44db13742543
Ref: library/typing typing TypeVar has_default13743074
Ref: 44dc13743074
Ref: library/typing typevartuple13743732
Ref: 44ce13743732
Ref: library/typing typing TypeVarTuple13743732
Ref: 48913743732
Ref: library/typing typing TypeVarTuple __name__13747997
Ref: 44dd13747997
Ref: library/typing typing TypeVarTuple __default__13748075
Ref: 44de13748075
Ref: library/typing typing TypeVarTuple evaluate_default13748263
Ref: 44df13748263
Ref: library/typing typing TypeVarTuple has_default13748794
Ref: 44e013748794
Ref: library/typing typing ParamSpec13749447
Ref: 48813749447
Ref: library/typing typing ParamSpec args13751944
Ref: 44e213751944
Ref: library/typing typing ParamSpec kwargs13751970
Ref: 44e313751970
Ref: library/typing typing ParamSpec __name__13752734
Ref: 44e413752734
Ref: library/typing typing ParamSpec __default__13752816
Ref: 44e513752816
Ref: library/typing typing ParamSpec evaluate_default13753008
Ref: 44e613753008
Ref: library/typing typing ParamSpec has_default13753539
Ref: 44e713753539
Ref: library/typing typing ParamSpecArgs13754894
Ref: 9cb13754894
Ref: library/typing typing ParamSpecKwargs13754925
Ref: 9cc13754925
Ref: library/typing typing TypeAliasType13755640
Ref: 2ae13755640
Ref: library/typing typing TypeAliasType __name__13755934
Ref: 44e813755934
Ref: library/typing typing TypeAliasType __module__13756097
Ref: 44e913756097
Ref: library/typing typing TypeAliasType __type_params__13756299
Ref: 44ea13756299
Ref: library/typing typing TypeAliasType __value__13756670
Ref: 44eb13756670
Ref: library/typing typing TypeAliasType evaluate_value13757230
Ref: 44ec13757230
Ref: Building generic types and type aliases-Footnote-113758742
Ref: Building generic types and type aliases-Footnote-213758784
Ref: Building generic types and type aliases-Footnote-313758826
Ref: Building generic types and type aliases-Footnote-413758868
Ref: Building generic types and type aliases-Footnote-513758910
Ref: Building generic types and type aliases-Footnote-613758952
Ref: Building generic types and type aliases-Footnote-713758994
Node: Other special directives13759036
Ref: library/typing other-special-directives13759170
Ref: 44ed13759170
Ref: library/typing typing NamedTuple13759396
Ref: 33113759396
Ref: library/typing typing NewType13763008
Ref: ef313763008
Ref: library/typing typing NewType __module__13763450
Ref: 44ee13763450
Ref: library/typing typing NewType __name__13763550
Ref: 44ef13763550
Ref: library/typing typing NewType __supertype__13763617
Ref: 44f013763617
Ref: library/typing typing Protocol13763827
Ref: 56b13763827
Ref: library/typing typing runtime_checkable13765209
Ref: 67513765209
Ref: library/typing typing TypedDict13767895
Ref: 33213767895
Ref: library/typing typing TypedDict __total__13772633
Ref: 44f113772633
Ref: library/typing typing TypedDict __required_keys__13773697
Ref: 44f213773697
Ref: library/typing typing TypedDict __optional_keys__13773769
Ref: 44f313773769
Ref: library/typing typing TypedDict __readonly_keys__13775582
Ref: 44f413775582
Ref: library/typing typing TypedDict __mutable_keys__13775824
Ref: 44f513775824
Ref: Other special directives-Footnote-113777382
Ref: Other special directives-Footnote-213777424
Ref: Other special directives-Footnote-313777466
Ref: Other special directives-Footnote-413777540
Node: Protocols<4>13777582
Ref: library/typing protocols13777731
Ref: 44f613777731
Ref: library/typing typing SupportsAbs13777893
Ref: 44f713777893
Ref: library/typing typing SupportsBytes13778020
Ref: 80113778020
Ref: library/typing typing SupportsComplex13778109
Ref: 80013778109
Ref: library/typing typing SupportsFloat13778202
Ref: 44f813778202
Ref: library/typing typing SupportsIndex13778291
Ref: c3c13778291
Ref: library/typing typing SupportsInt13778408
Ref: c3b13778408
Ref: library/typing typing SupportsRound13778493
Ref: 44f913778493
Node: ABCs and Protocols for working with I/O13778624
Ref: library/typing abcs-and-protocols-for-working-with-i-o13778772
Ref: 44fa13778772
Ref: library/typing typing-io13778772
Ref: 310f13778772
Ref: library/typing typing IO13778873
Ref: 23813778873
Ref: library/typing typing TextIO13778904
Ref: 23913778904
Ref: library/typing typing BinaryIO13778930
Ref: 23a13778930
Node: Functions and decorators13779772
Ref: library/typing functions-and-decorators13779929
Ref: 44fb13779929
Ref: library/typing typing cast13780000
Ref: 44e113780000
Ref: library/typing typing assert_type13780301
Ref: 8bb13780301
Ref: library/typing typing assert_never13781396
Ref: 8b713781396
Ref: library/typing typing reveal_type13782805
Ref: 8ba13782805
Ref: library/typing typing dataclass_transform13783999
Ref: 6fc13783999
Ref: library/typing overload13790028
Ref: 44bd13790028
Ref: library/typing typing overload13790028
Ref: 44fc13790028
Ref: library/typing typing get_overloads13791564
Ref: 8be13791564
Ref: library/typing typing clear_overloads13792239
Ref: 8bf13792239
Ref: library/typing typing final13792439
Ref: 8bd13792439
Ref: library/typing typing no_type_check13793705
Ref: 8c413793705
Ref: library/typing typing no_type_check_decorator13794193
Ref: 33313794193
Ref: library/typing typing override13794659
Ref: 67d13794659
Ref: library/typing typing type_check_only13796005
Ref: 44fd13796005
Ref: Functions and decorators-Footnote-113796713
Ref: Functions and decorators-Footnote-213796781
Ref: Functions and decorators-Footnote-313796823
Ref: Functions and decorators-Footnote-413796865
Ref: Functions and decorators-Footnote-513796907
Node: Introspection helpers13796949
Ref: library/typing introspection-helpers13797075
Ref: 44fe13797075
Ref: library/typing typing get_type_hints13797140
Ref: 8c113797140
Ref: library/typing typing get_origin13799968
Ref: 2ab13799968
Ref: library/typing typing get_args13800828
Ref: 2ac13800828
Ref: library/typing typing get_protocol_members13801470
Ref: 56a13801470
Ref: library/typing typing is_protocol13801928
Ref: 56c13801928
Ref: library/typing typing is_typeddict13802234
Ref: a5813802234
Ref: library/typing typing ForwardRef13802680
Ref: 1bc213802680
Ref: library/typing typing evaluate_forward_ref13803569
Ref: 17fd13803569
Ref: library/typing typing NoDefault13804474
Ref: 56913804474
Ref: Introspection helpers-Footnote-113804862
Ref: Introspection helpers-Footnote-213804904
Node: Constant13804946
Ref: library/typing constant13805066
Ref: 450013805066
Ref: library/typing typing TYPE_CHECKING13805105
Ref: ef213805105
Ref: library/typing generic-concrete-collections13806503
Ref: 450113806503
Ref: Constant-Footnote-113806539
Node: Deprecated aliases13806581
Ref: library/typing deprecated-aliases13806671
Ref: 450213806671
Ref: library/typing id613806671
Ref: 450313806671
Ref: Deprecated aliases-Footnote-113808255
Node: Aliases to built-in types13808297
Ref: library/typing aliases-to-built-in-types13808417
Ref: 450413808417
Ref: library/typing corresponding-to-built-in-types13808417
Ref: 450513808417
Ref: library/typing typing Dict13808490
Ref: 450613808490
Ref: library/typing typing List13808936
Ref: 450713808936
Ref: library/typing typing Set13809405
Ref: 450813809405
Ref: library/typing typing FrozenSet13809864
Ref: 450913809864
Ref: library/typing typing Tuple13810148
Ref: 450a13810148
Ref: library/typing typing Type13810515
Ref: 44c213810515
Ref: Aliases to built-in types-Footnote-113810961
Ref: Aliases to built-in types-Footnote-213811003
Ref: Aliases to built-in types-Footnote-313811045
Ref: Aliases to built-in types-Footnote-413811087
Ref: Aliases to built-in types-Footnote-513811129
Ref: Aliases to built-in types-Footnote-613811171
Node: Aliases to types in collections13811213
Ref: library/typing aliases-to-types-in-collections13811373
Ref: 450b13811373
Ref: library/typing corresponding-to-types-in-collections13811373
Ref: 450c13811373
Ref: library/typing typing DefaultDict13811466
Ref: 450d13811466
Ref: library/typing typing OrderedDict13811823
Ref: 450e13811823
Ref: library/typing typing ChainMap13812178
Ref: 450f13812178
Ref: library/typing typing Counter13812521
Ref: 451013812521
Ref: library/typing typing Deque13812842
Ref: 451113812842
Ref: Aliases to types in collections-Footnote-113813183
Ref: Aliases to types in collections-Footnote-213813225
Ref: Aliases to types in collections-Footnote-313813267
Ref: Aliases to types in collections-Footnote-413813309
Ref: Aliases to types in collections-Footnote-513813351
Node: Aliases to other concrete types13813393
Ref: library/typing aliases-to-other-concrete-types13813572
Ref: 451213813572
Ref: library/typing other-concrete-types13813572
Ref: 451313813572
Ref: library/typing typing Pattern13813657
Ref: 93613813657
Ref: library/typing typing Match13813684
Ref: 451413813684
Ref: library/typing typing Text13814266
Ref: 36013814266
Ref: library/typing abstract-base-classes13815029
Ref: 451513815029
Ref: Aliases to other concrete types-Footnote-113815065
Node: Aliases to container ABCs in collections abc13815107
Ref: library/typing aliases-to-container-abcs-in-collections-abc13815302
Ref: 451613815302
Ref: library/typing corresponding-to-collections-in-collections-abc13815302
Ref: 451713815302
Ref: library/typing typing AbstractSet13815421
Ref: 451813815421
Ref: library/typing typing ByteString13815699
Ref: 34513815699
Ref: library/typing typing Collection13816762
Ref: ef113816762
Ref: library/typing typing Container13817101
Ref: 451913817101
Ref: library/typing typing ItemsView13817386
Ref: 451a13817386
Ref: library/typing typing KeysView13817713
Ref: 451b13817713
Ref: library/typing typing Mapping13818013
Ref: 451c13818013
Ref: library/typing typing MappingView13818311
Ref: 451d13818311
Ref: library/typing typing MutableMapping13818594
Ref: 451e13818594
Ref: library/typing typing MutableSequence13818896
Ref: 451f13818896
Ref: library/typing typing MutableSet13819196
Ref: 452013819196
Ref: library/typing typing Sequence13819486
Ref: 452113819486
Ref: library/typing typing ValuesView13819790
Ref: 452213819790
Ref: Aliases to container ABCs in collections abc-Footnote-113820133
Ref: Aliases to container ABCs in collections abc-Footnote-213820175
Ref: Aliases to container ABCs in collections abc-Footnote-313820233
Ref: Aliases to container ABCs in collections abc-Footnote-413820275
Ref: Aliases to container ABCs in collections abc-Footnote-513820317
Ref: Aliases to container ABCs in collections abc-Footnote-613820359
Ref: Aliases to container ABCs in collections abc-Footnote-713820401
Ref: Aliases to container ABCs in collections abc-Footnote-813820443
Ref: Aliases to container ABCs in collections abc-Footnote-913820485
Ref: Aliases to container ABCs in collections abc-Footnote-1013820527
Ref: Aliases to container ABCs in collections abc-Footnote-1113820570
Ref: Aliases to container ABCs in collections abc-Footnote-1213820613
Ref: Aliases to container ABCs in collections abc-Footnote-1313820656
Node: Aliases to asynchronous ABCs in collections abc13820699
Ref: library/typing aliases-to-asynchronous-abcs-in-collections-abc13820903
Ref: 452313820903
Ref: library/typing asynchronous-programming13820903
Ref: 452413820903
Ref: library/typing typing Coroutine13821028
Ref: 1d1913821028
Ref: library/typing typing AsyncGenerator13821578
Ref: 198b13821578
Ref: library/typing typing AsyncIterable13822233
Ref: 452513822233
Ref: library/typing typing AsyncIterator13822558
Ref: 452613822558
Ref: library/typing typing Awaitable13822889
Ref: 452713822889
Ref: Aliases to asynchronous ABCs in collections abc-Footnote-113823238
Ref: Aliases to asynchronous ABCs in collections abc-Footnote-213823280
Ref: Aliases to asynchronous ABCs in collections abc-Footnote-313823322
Ref: Aliases to asynchronous ABCs in collections abc-Footnote-413823364
Ref: Aliases to asynchronous ABCs in collections abc-Footnote-513823406
Node: Aliases to other ABCs in collections abc13823448
Ref: library/typing aliases-to-other-abcs-in-collections-abc13823634
Ref: 452813823634
Ref: library/typing corresponding-to-other-types-in-collections-abc13823634
Ref: 452913823634
Ref: library/typing typing Iterable13823745
Ref: 452a13823745
Ref: library/typing typing Iterator13824027
Ref: 452b13824027
Ref: library/typing typing Callable13824310
Ref: 9ca13824310
Ref: library/typing typing Generator13824901
Ref: 198a13824901
Ref: library/typing typing Hashable13825517
Ref: 71813825517
Ref: library/typing typing Reversible13825710
Ref: 452c13825710
Ref: library/typing typing Sized13825997
Ref: 71913825997
Ref: Aliases to other ABCs in collections abc-Footnote-113826217
Ref: Aliases to other ABCs in collections abc-Footnote-213826259
Ref: Aliases to other ABCs in collections abc-Footnote-313826301
Ref: Aliases to other ABCs in collections abc-Footnote-413826343
Ref: Aliases to other ABCs in collections abc-Footnote-513826385
Ref: Aliases to other ABCs in collections abc-Footnote-613826427
Node: Aliases to contextlib ABCs13826469
Ref: library/typing aliases-to-contextlib-abcs13826599
Ref: 452d13826599
Ref: library/typing context-manager-types13826599
Ref: 452e13826599
Ref: library/typing typing ContextManager13826682
Ref: e8d13826682
Ref: library/typing typing AsyncContextManager13827410
Ref: 198813827410
Ref: Aliases to contextlib ABCs-Footnote-113828205
Ref: Aliases to contextlib ABCs-Footnote-213828247
Node: Deprecation Timeline of Major Features13828289
Ref: library/typing deprecation-timeline-of-major-features13828424
Ref: 452f13828424
Ref: Deprecation Timeline of Major Features-Footnote-113831180
Ref: Deprecation Timeline of Major Features-Footnote-213831222
Ref: Deprecation Timeline of Major Features-Footnote-313831277
Ref: Deprecation Timeline of Major Features-Footnote-413831332
Ref: Deprecation Timeline of Major Features-Footnote-513831387
Ref: Deprecation Timeline of Major Features-Footnote-613831429
Ref: Deprecation Timeline of Major Features-Footnote-713831485
Node: pydoc — Documentation generator and online help system13831541
Ref: library/pydoc doc13831725
Ref: 453013831725
Ref: library/pydoc module-pydoc13831725
Ref: ba13831725
Ref: library/pydoc pydoc-documentation-generator-and-online-help-system13831725
Ref: 453113831725
Ref: library/pydoc translation-repo13831725
Ref: 453213831725
Ref: pydoc — Documentation generator and online help system-Footnote-113836734
Node: Python Development Mode13836799
Ref: library/devmode doc13836994
Ref: 453313836994
Ref: library/devmode devmode13836994
Ref: 50913836994
Ref: library/devmode python-development-mode13836994
Ref: 453413836994
Ref: library/devmode translation-repo13836994
Ref: 453513836994
Node: Effects of the Python Development Mode13837629
Ref: library/devmode effects-of-the-python-development-mode13837759
Ref: 453613837759
Node: ResourceWarning Example13841468
Ref: library/devmode resourcewarning-example13841640
Ref: 453713841640
Node: Bad file descriptor error example13843553
Ref: library/devmode bad-file-descriptor-error-example13843678
Ref: 453813843678
Ref: Bad file descriptor error example-Footnote-113845211
Node: doctest — Test interactive Python examples13845276
Ref: library/doctest doc13845450
Ref: 453913845450
Ref: library/doctest doctest-test-interactive-python-examples13845450
Ref: 453a13845450
Ref: library/doctest module-doctest13845450
Ref: 3e13845450
Ref: library/doctest translation-repo13845450
Ref: 453b13845450
Ref: doctest — Test interactive Python examples-Footnote-113849701
Node: Simple Usage Checking Examples in Docstrings13849768
Ref: library/doctest doctest-simple-testmod13849947
Ref: 453c13849947
Ref: library/doctest simple-usage-checking-examples-in-docstrings13849947
Ref: 453d13849947
Node: Simple Usage Checking Examples in a Text File13851370
Ref: library/doctest doctest-simple-testfile13851576
Ref: 454013851576
Ref: library/doctest simple-usage-checking-examples-in-a-text-file13851576
Ref: 454113851576
Node: Command-line Usage13853622
Ref: library/doctest command-line-usage13853796
Ref: 454313853796
Ref: library/doctest doctest-cli13853796
Ref: 453e13853796
Ref: library/doctest cmdoption-doctest-v13853996
Ref: 454413853996
Ref: library/doctest cmdoption-doctest-verbose13853996
Ref: 454513853996
Ref: library/doctest cmdoption-doctest-o13854604
Ref: 454613854604
Ref: library/doctest cmdoption-doctest-option13854604
Ref: 454713854604
Ref: library/doctest cmdoption-doctest-f13854778
Ref: 454813854778
Ref: library/doctest cmdoption-doctest-fail-fast13854778
Ref: 454913854778
Node: How It Works13854883
Ref: library/doctest doctest-how-it-works13855021
Ref: 454a13855021
Ref: library/doctest how-it-works13855021
Ref: 454b13855021
Node: Which Docstrings Are Examined?13855676
Ref: library/doctest doctest-which-docstrings13855802
Ref: 454c13855802
Ref: library/doctest which-docstrings-are-examined13855802
Ref: 454d13855802
Ref: library/doctest module __test__13856018
Ref: 454e13856018
Node: How are Docstring Examples Recognized?13857614
Ref: library/doctest doctest-finding-examples13857780
Ref: 454f13857780
Ref: library/doctest how-are-docstring-examples-recognized13857780
Ref: 455013857780
Node: What’s the Execution Context?13860896
Ref: library/doctest doctest-execution-context13861054
Ref: 455413861054
Ref: library/doctest what-s-the-execution-context13861054
Ref: 455513861054
Node: What About Exceptions?13861772
Ref: library/doctest doctest-exceptions13861904
Ref: 455613861904
Ref: library/doctest what-about-exceptions13861904
Ref: 455713861904
Ref: library/doctest option-flags-and-directives13866451
Ref: 455813866451
Ref: What About Exceptions?-Footnote-113866488
Node: Option Flags13866688
Ref: library/doctest doctest-options13866799
Ref: 113513866799
Ref: library/doctest option-flags13866799
Ref: 455913866799
Ref: library/doctest doctest DONT_ACCEPT_TRUE_FOR_113867362
Ref: 455a13867362
Ref: library/doctest doctest DONT_ACCEPT_BLANKLINE13867988
Ref: 455b13867988
Ref: library/doctest doctest NORMALIZE_WHITESPACE13868441
Ref: 455113868441
Ref: library/doctest doctest ELLIPSIS13868931
Ref: 167513868931
Ref: library/doctest doctest IGNORE_EXCEPTION_DETAIL13869365
Ref: 151013869365
Ref: library/doctest doctest SKIP13870834
Ref: 455c13870834
Ref: library/doctest doctest COMPARISON_FLAGS13871346
Ref: 455d13871346
Ref: library/doctest doctest REPORT_UDIFF13871518
Ref: 167613871518
Ref: library/doctest doctest REPORT_CDIFF13871674
Ref: 167713871674
Ref: library/doctest doctest REPORT_NDIFF13871834
Ref: 167813871834
Ref: library/doctest doctest REPORT_ONLY_FIRST_FAILURE13872298
Ref: 455e13872298
Ref: library/doctest doctest FAIL_FAST13872877
Ref: 113613872877
Ref: library/doctest doctest REPORTING_FLAGS13873215
Ref: 455f13873215
Ref: library/doctest doctest register_optionflag13873472
Ref: 456013873472
Node: Directives13873962
Ref: library/doctest directives13874062
Ref: 456313874062
Ref: library/doctest doctest-directives13874062
Ref: 455213874062
Ref: library/doctest grammar-token-doctest-directive13874290
Ref: 456413874290
Ref: library/doctest grammar-token-doctest-directive_options13874364
Ref: 456513874364
Ref: library/doctest grammar-token-doctest-directive_option13874459
Ref: 456613874459
Ref: library/doctest grammar-token-doctest-on_or_off13874545
Ref: 456713874545
Ref: library/doctest grammar-token-doctest-directive_option_name13874583
Ref: 456813874583
Node: Warnings<2>13876681
Ref: library/doctest doctest-warnings13876760
Ref: 456913876760
Ref: library/doctest warnings13876760
Ref: 456a13876760
Node: Basic API13878512
Ref: library/doctest basic-api13878644
Ref: 456b13878644
Ref: library/doctest doctest-basic-api13878644
Ref: 453f13878644
Ref: library/doctest doctest testfile13879028
Ref: 454213879028
Ref: library/doctest doctest testmod13882974
Ref: 167413882974
Ref: library/doctest doctest run_docstring_examples13884698
Ref: 456d13884698
Node: Unittest API13885676
Ref: library/doctest doctest-unittest-api13885808
Ref: 456e13885808
Ref: library/doctest unittest-api13885808
Ref: 456f13885808
Ref: library/doctest doctest DocFileSuite13886583
Ref: 457113886583
Ref: library/doctest doctest DocTestSuite13890451
Ref: ff613890451
Ref: library/doctest doctest set_unittest_reportflags13893788
Ref: 457413893788
Node: Advanced API13894961
Ref: library/doctest advanced-api13895093
Ref: 457513895093
Ref: library/doctest doctest-advanced-api13895093
Ref: 457613895093
Node: DocTest Objects13897258
Ref: library/doctest doctest-doctest13897346
Ref: 457813897346
Ref: library/doctest doctest-objects13897346
Ref: 457913897346
Ref: library/doctest doctest DocTest13897399
Ref: 1a1113897399
Ref: library/doctest doctest DocTest examples13897816
Ref: 457a13897816
Ref: library/doctest doctest DocTest globs13897991
Ref: 457313897991
Ref: library/doctest doctest DocTest name13898326
Ref: 457b13898326
Ref: library/doctest doctest DocTest filename13898519
Ref: 457c13898519
Ref: library/doctest doctest DocTest lineno13898749
Ref: 17af13898749
Ref: library/doctest doctest DocTest docstring13899027
Ref: 457d13899027
Node: Example Objects13899226
Ref: library/doctest doctest-example13899344
Ref: 457e13899344
Ref: library/doctest example-objects13899344
Ref: 457f13899344
Ref: library/doctest doctest Example13899397
Ref: 457713899397
Ref: library/doctest doctest Example source13899837
Ref: 458013899837
Ref: library/doctest doctest Example want13900081
Ref: 458113900081
Ref: library/doctest doctest Example exc_msg13900432
Ref: 458213900432
Ref: library/doctest doctest Example lineno13900916
Ref: 458313900916
Ref: library/doctest doctest Example indent13901147
Ref: 458413901147
Ref: library/doctest doctest Example options13901340
Ref: 458513901340
Node: DocTestFinder objects13901753
Ref: library/doctest doctest-doctestfinder13901877
Ref: 458613901877
Ref: library/doctest doctestfinder-objects13901877
Ref: 458713901877
Ref: library/doctest doctest DocTestFinder13901942
Ref: 199013901942
Ref: library/doctest doctest DocTestFinder find13903082
Ref: 1a5713903082
Node: DocTestParser objects13905206
Ref: library/doctest doctest-doctestparser13905334
Ref: 458813905334
Ref: library/doctest doctestparser-objects13905334
Ref: 458913905334
Ref: library/doctest doctest DocTestParser13905399
Ref: 455313905399
Ref: library/doctest doctest DocTestParser get_doctest13905634
Ref: 458a13905634
Ref: library/doctest doctest DocTestParser get_examples13906022
Ref: 458b13906022
Ref: library/doctest doctest DocTestParser parse13906360
Ref: 458c13906360
Node: TestResults objects13906748
Ref: library/doctest testresults-objects13906876
Ref: 458d13906876
Ref: library/doctest doctest TestResults13906937
Ref: 458e13906937
Ref: library/doctest doctest TestResults failed13906990
Ref: 458f13906990
Ref: library/doctest doctest TestResults attempted13907053
Ref: 459013907053
Ref: library/doctest doctest TestResults skipped13907122
Ref: 4f113907122
Node: DocTestRunner objects13907221
Ref: library/doctest doctest-doctestrunner13907349
Ref: 459113907349
Ref: library/doctest doctestrunner-objects13907349
Ref: 459213907349
Ref: library/doctest doctest DocTestRunner13907414
Ref: 456213907414
Ref: library/doctest doctest DocTestRunner report_start13909849
Ref: 459313909849
Ref: library/doctest doctest DocTestRunner report_success13910347
Ref: 459413910347
Ref: library/doctest doctest DocTestRunner report_failure13910879
Ref: 459613910879
Ref: library/doctest doctest DocTestRunner report_unexpected_exception13911401
Ref: 459513911401
Ref: library/doctest doctest DocTestRunner run13912075
Ref: 4ef13912075
Ref: library/doctest doctest DocTestRunner summarize13913145
Ref: 456c13913145
Ref: library/doctest doctest DocTestRunner tries13913606
Ref: 459713913606
Ref: library/doctest doctest DocTestRunner failures13913674
Ref: 459813913674
Ref: library/doctest doctest DocTestRunner skips13913742
Ref: 4f013913742
Node: OutputChecker objects13913842
Ref: library/doctest doctest-outputchecker13913942
Ref: 459913913942
Ref: library/doctest outputchecker-objects13913942
Ref: 459a13913942
Ref: library/doctest doctest OutputChecker13914007
Ref: 456113914007
Ref: library/doctest doctest OutputChecker check_output13914504
Ref: 459b13914504
Ref: library/doctest doctest OutputChecker output_difference13914992
Ref: 459c13914992
Node: Debugging13915307
Ref: library/doctest debugging13915434
Ref: 459d13915434
Ref: library/doctest doctest-debugging13915434
Ref: 459e13915434
Ref: library/doctest doctest script_from_examples13917533
Ref: 45a113917533
Ref: library/doctest doctest testsource13918520
Ref: 45a213918520
Ref: library/doctest doctest debug13919317
Ref: 45a013919317
Ref: library/doctest doctest debug_src13920408
Ref: 45a413920408
Ref: library/doctest doctest DebugRunner13921282
Ref: 459f13921282
Ref: library/doctest doctest DocTestFailure13922060
Ref: 45a613922060
Ref: library/doctest doctest DocTestFailure test13922423
Ref: 45a713922423
Ref: library/doctest doctest DocTestFailure example13922546
Ref: 45a813922546
Ref: library/doctest doctest DocTestFailure got13922629
Ref: 45a913922629
Ref: library/doctest doctest UnexpectedException13922701
Ref: 45a513922701
Ref: library/doctest doctest UnexpectedException test13923054
Ref: 45aa13923054
Ref: library/doctest doctest UnexpectedException example13923182
Ref: 45ab13923182
Ref: library/doctest doctest UnexpectedException exc_info13923270
Ref: 45ac13923270
Node: Soapbox13923431
Ref: library/doctest doctest-soapbox13923537
Ref: 45ad13923537
Ref: library/doctest soapbox13923537
Ref: 45ae13923537
Node: unittest — Unit testing framework13927376
Ref: library/unittest doc13927564
Ref: 45af13927564
Ref: library/unittest module-unittest13927564
Ref: 10c13927564
Ref: library/unittest translation-repo13927564
Ref: 45b013927564
Ref: library/unittest unittest-unit-testing-framework13927564
Ref: 45b113927564
Ref: unittest — Unit testing framework-Footnote-113930728
Ref: unittest — Unit testing framework-Footnote-213930806
Ref: unittest — Unit testing framework-Footnote-313930899
Ref: unittest — Unit testing framework-Footnote-413930932
Ref: unittest — Unit testing framework-Footnote-513930996
Ref: unittest — Unit testing framework-Footnote-613931054
Ref: unittest — Unit testing framework-Footnote-713931084
Ref: unittest — Unit testing framework-Footnote-813931116
Ref: unittest — Unit testing framework-Footnote-913931160
Node: Basic example13931194
Ref: library/unittest basic-example13931313
Ref: 45b313931313
Ref: library/unittest unittest-minimal-example13931313
Ref: 45b413931313
Node: Command-Line Interface<2>13934303
Ref: library/unittest command-line-interface13934445
Ref: 45b613934445
Ref: library/unittest unittest-command-line-interface13934445
Ref: 45b713934445
Node: Command-line options<5>13935963
Ref: library/unittest command-line-options13936048
Ref: 45b913936048
Ref: library/unittest cmdoption-unittest-b13936162
Ref: 153913936162
Ref: library/unittest cmdoption-unittest-buffer13936162
Ref: 45ba13936162
Ref: library/unittest cmdoption-unittest-c13936421
Ref: 153a13936421
Ref: library/unittest cmdoption-unittest-catch13936421
Ref: 45bb13936421
Ref: library/unittest cmdoption-unittest-f13936765
Ref: 153c13936765
Ref: library/unittest cmdoption-unittest-failfast13936765
Ref: 45bd13936765
Ref: library/unittest cmdoption-unittest-k13936848
Ref: 45be13936848
Ref: library/unittest cmdoption-unittest-locals13937560
Ref: 45bf13937560
Ref: library/unittest cmdoption-unittest-durations13937624
Ref: 45c013937624
Node: Test Discovery13938096
Ref: library/unittest test-discovery13938245
Ref: 45c113938245
Ref: library/unittest unittest-test-discovery13938245
Ref: 45b813938245
Ref: library/unittest cmdoption-unittest-discover-v13939101
Ref: 45c213939101
Ref: library/unittest cmdoption-unittest-discover-verbose13939101
Ref: 45c313939101
Ref: library/unittest cmdoption-unittest-discover-s13939149
Ref: 45c413939149
Ref: library/unittest cmdoption-unittest-discover-start-directory13939149
Ref: 45c513939149
Ref: library/unittest cmdoption-unittest-discover-p13939247
Ref: 45c613939247
Ref: library/unittest cmdoption-unittest-discover-pattern13939247
Ref: 45c713939247
Ref: library/unittest cmdoption-unittest-discover-t13939341
Ref: 45c813939341
Ref: library/unittest cmdoption-unittest-discover-top-level-directory13939341
Ref: 45c913939341
Node: Organizing test code13941577
Ref: library/unittest organizing-test-code13941723
Ref: 45cb13941723
Ref: library/unittest organizing-tests13941723
Ref: 45b513941723
Node: Re-using old test code13946499
Ref: library/unittest legacy-unit-tests13946667
Ref: 45cc13946667
Ref: library/unittest re-using-old-test-code13946667
Ref: 45cd13946667
Node: Skipping tests and expected failures13948213
Ref: library/unittest skipping-tests-and-expected-failures13948406
Ref: 45ce13948406
Ref: library/unittest unittest-skipping13948406
Ref: 45cf13948406
Ref: library/unittest unittest skip13951563
Ref: 1da613951563
Ref: library/unittest unittest skipIf13951711
Ref: 45d213951711
Ref: library/unittest unittest skipUnless13951817
Ref: 45d313951817
Ref: library/unittest unittest expectedFailure13951931
Ref: 45d113951931
Ref: library/unittest unittest SkipTest13952240
Ref: 11e613952240
Node: Distinguishing test iterations using subtests13952744
Ref: library/unittest distinguishing-test-iterations-using-subtests13952936
Ref: 45d413952936
Ref: library/unittest subtests13952936
Ref: 11e413952936
Node: Classes and functions13955540
Ref: library/unittest classes-and-functions13955721
Ref: 45d513955721
Ref: library/unittest unittest-contents13955721
Ref: 45d613955721
Node: Test cases13955923
Ref: library/unittest test-cases13956014
Ref: 45d713956014
Ref: library/unittest testcase-objects13956014
Ref: 45d813956014
Ref: library/unittest unittest TestCase13956057
Ref: 2b313956057
Ref: library/unittest unittest TestCase setUp13957385
Ref: 154113957385
Ref: library/unittest unittest TestCase tearDown13957763
Ref: 154213957763
Ref: library/unittest unittest TestCase setUpClass13958538
Ref: c4513958538
Ref: library/unittest unittest TestCase tearDownClass13958979
Ref: 153f13958979
Ref: library/unittest unittest TestCase run13959429
Ref: 136e13959429
Ref: library/unittest unittest TestCase skipTest13960063
Ref: 45d013960063
Ref: library/unittest unittest TestCase subTest13960322
Ref: 11e313960322
Ref: library/unittest unittest TestCase debug13960880
Ref: 1c3113960880
Ref: library/unittest assert-methods13961115
Ref: 45b213961115
Ref: library/unittest unittest TestCase assertEqual13965497
Ref: 74d13965497
Ref: library/unittest unittest TestCase assertNotEqual13966379
Ref: 74e13966379
Ref: library/unittest unittest TestCase assertTrue13966558
Ref: 74b13966558
Ref: library/unittest unittest TestCase assertFalse13966603
Ref: 74c13966603
Ref: library/unittest unittest TestCase assertIs13967104
Ref: 154313967104
Ref: library/unittest unittest TestCase assertIsNot13967156
Ref: 154413967156
Ref: library/unittest unittest TestCase assertIsNone13967331
Ref: 149213967331
Ref: library/unittest unittest TestCase assertIsNotNone13967378
Ref: 149313967378
Ref: library/unittest unittest TestCase assertIn13967517
Ref: 154c13967517
Ref: library/unittest unittest TestCase assertNotIn13967573
Ref: 154d13967573
Ref: library/unittest unittest TestCase assertIsInstance13967727
Ref: 154513967727
Ref: library/unittest unittest TestCase assertNotIsInstance13967782
Ref: 154613967782
Ref: library/unittest unittest TestCase assertIsSubclass13968127
Ref: 2b613968127
Ref: library/unittest unittest TestCase assertNotIsSubclass13968189
Ref: 2b713968189
Ref: library/unittest unittest TestCase assertRaises13971391
Ref: 75113971391
Ref: library/unittest unittest TestCase assertRaisesRegex13973133
Ref: 75313973133
Ref: library/unittest unittest TestCase assertWarns13974153
Ref: 136c13974153
Ref: library/unittest unittest TestCase assertWarnsRegex13975873
Ref: 136d13975873
Ref: library/unittest unittest TestCase assertLogs13976818
Ref: a5b13976818
Ref: library/unittest unittest TestCase records13977894
Ref: 45dc13977894
Ref: library/unittest unittest TestCase output13978038
Ref: 45dd13978038
Ref: library/unittest unittest TestCase assertNoLogs13978587
Ref: a5a13978587
Ref: library/unittest unittest TestCase assertAlmostEqual13983775
Ref: 74f13983775
Ref: library/unittest unittest TestCase assertNotAlmostEqual13983873
Ref: 75013983873
Ref: library/unittest unittest TestCase assertGreater13984950
Ref: 154713984950
Ref: library/unittest unittest TestCase assertGreaterEqual13985007
Ref: 154813985007
Ref: library/unittest unittest TestCase assertLess13985069
Ref: 154913985069
Ref: library/unittest unittest TestCase assertLessEqual13985123
Ref: 154a13985123
Ref: library/unittest unittest TestCase assertRegex13985490
Ref: 75213985490
Ref: library/unittest unittest TestCase assertNotRegex13985543
Ref: 75413985543
Ref: library/unittest unittest TestCase assertCountEqual13986300
Ref: 143213986300
Ref: library/unittest unittest TestCase assertStartsWith13986963
Ref: 2b813986963
Ref: library/unittest unittest TestCase assertNotStartsWith13987020
Ref: 2b913987020
Ref: library/unittest unittest TestCase assertEndsWith13987279
Ref: 2ba13987279
Ref: library/unittest unittest TestCase assertNotEndsWith13987334
Ref: 2bb13987334
Ref: library/unittest unittest TestCase assertHasAttr13987587
Ref: 2b413987587
Ref: library/unittest unittest TestCase assertNotHasAttr13987641
Ref: 2b513987641
Ref: library/unittest type-specific-methods13987818
Ref: 45db13987818
Ref: library/unittest unittest TestCase addTypeEqualityFunc13988137
Ref: 155013988137
Ref: library/unittest unittest TestCase assertMultiLineEqual13990883
Ref: 154b13990883
Ref: library/unittest unittest TestCase assertSequenceEqual13991300
Ref: 149113991300
Ref: library/unittest unittest TestCase assertListEqual13991929
Ref: 148f13991929
Ref: library/unittest unittest TestCase assertTupleEqual13991988
Ref: 149013991988
Ref: library/unittest unittest TestCase assertSetEqual13992438
Ref: 148d13992438
Ref: library/unittest unittest TestCase assertDictEqual13992895
Ref: 148e13992895
Ref: library/unittest other-methods-and-attrs13993255
Ref: 45de13993255
Ref: library/unittest unittest TestCase fail13993346
Ref: 45df13993346
Ref: library/unittest unittest TestCase failureException13993489
Ref: 457213993489
Ref: library/unittest unittest TestCase longMessage13993902
Ref: 153d13993902
Ref: library/unittest unittest TestCase maxDiff13994642
Ref: 143313994642
Ref: library/unittest unittest TestCase countTestCases13995338
Ref: 45e013995338
Ref: library/unittest unittest TestCase defaultTestResult13995520
Ref: 45da13995520
Ref: library/unittest unittest TestCase id13995952
Ref: 45e113995952
Ref: library/unittest unittest TestCase shortDescription13996147
Ref: 45e213996147
Ref: library/unittest unittest TestCase addCleanup13996771
Ref: c7613996771
Ref: library/unittest unittest TestCase enterContext13997379
Ref: 8c913997379
Ref: library/unittest unittest TestCase doCleanups13997708
Ref: 154013997708
Ref: library/unittest unittest TestCase addClassCleanup13998364
Ref: c4313998364
Ref: library/unittest unittest TestCase enterClassContext13999040
Ref: 8ca13999040
Ref: library/unittest unittest TestCase doClassCleanups13999391
Ref: 45e313999391
Ref: library/unittest unittest IsolatedAsyncioTestCase14000097
Ref: 36114000097
Ref: library/unittest unittest IsolatedAsyncioTestCase loop_factory14000311
Ref: 45e414000311
Ref: library/unittest unittest IsolatedAsyncioTestCase asyncSetUp14000567
Ref: 45e514000567
Ref: library/unittest unittest IsolatedAsyncioTestCase asyncTearDown14001018
Ref: 45e614001018
Ref: library/unittest unittest IsolatedAsyncioTestCase addAsyncCleanup14001865
Ref: 45e714001865
Ref: library/unittest unittest IsolatedAsyncioTestCase enterAsyncContext14002023
Ref: 8cb14002023
Ref: library/unittest unittest IsolatedAsyncioTestCase run14002384
Ref: 45e814002384
Ref: library/unittest unittest FunctionTestCase14004129
Ref: 1a6114004129
Node: Grouping tests14004608
Ref: library/unittest grouping-tests14004733
Ref: 45e914004733
Ref: library/unittest testsuite-objects14004733
Ref: 45ea14004733
Ref: library/unittest unittest TestSuite14004784
Ref: ff714004784
Ref: library/unittest unittest TestSuite addTest14005732
Ref: 45eb14005732
Ref: library/unittest unittest TestSuite addTests14005852
Ref: 45ec14005852
Ref: library/unittest unittest TestSuite run14006228
Ref: 45ed14006228
Ref: library/unittest unittest TestSuite debug14006531
Ref: 45ee14006531
Ref: library/unittest unittest TestSuite countTestCases14006804
Ref: 45ef14006804
Ref: library/unittest unittest TestSuite __iter__14006968
Ref: 122b14006968
Node: Loading and running tests14008423
Ref: library/unittest loading-and-running-tests14008529
Ref: 45f014008529
Ref: library/unittest unittest TestLoader14008602
Ref: 59314008602
Ref: library/unittest unittest TestLoader errors14009097
Ref: 108e14009097
Ref: library/unittest unittest TestLoader loadTestsFromTestCase14009566
Ref: 59514009566
Ref: library/unittest unittest TestLoader loadTestsFromModule14010115
Ref: 59414010115
Ref: library/unittest unittest TestLoader loadTestsFromName14011520
Ref: 154e14011520
Ref: library/unittest unittest TestLoader loadTestsFromNames14013319
Ref: 45f214013319
Ref: library/unittest unittest TestLoader getTestCaseNames14013605
Ref: 59614013605
Ref: library/unittest unittest TestLoader discover14013808
Ref: 11e714013808
Ref: library/unittest unittest TestLoader testMethodPrefix14017161
Ref: 45f314017161
Ref: library/unittest unittest TestLoader sortTestMethodsUsing14017447
Ref: 45f414017447
Ref: library/unittest unittest TestLoader suiteClass14017658
Ref: 154f14017658
Ref: library/unittest unittest TestLoader testNamePatterns14017953
Ref: 45f514017953
Ref: library/unittest unittest TestResult14018667
Ref: 136f14018667
Ref: library/unittest unittest TestResult errors14019534
Ref: 45f614019534
Ref: library/unittest unittest TestResult failures14019764
Ref: 45f714019764
Ref: library/unittest unittest TestResult skipped14020048
Ref: 45f814020048
Ref: library/unittest unittest TestResult expectedFailures14020246
Ref: 45f914020246
Ref: library/unittest unittest TestResult unexpectedSuccesses14020488
Ref: 45fa14020488
Ref: library/unittest unittest TestResult collectedDurations14020653
Ref: 1a6414020653
Ref: library/unittest unittest TestResult shouldStop14020863
Ref: 45fb14020863
Ref: library/unittest unittest TestResult testsRun14020997
Ref: 45fd14020997
Ref: library/unittest unittest TestResult buffer14021076
Ref: 45fe14021076
Ref: library/unittest unittest TestResult failfast14021527
Ref: 460114021527
Ref: library/unittest unittest TestResult tb_locals14021714
Ref: 460214021714
Ref: library/unittest unittest TestResult wasSuccessful14021864
Ref: 460314021864
Ref: library/unittest unittest TestResult stop14022206
Ref: 45fc14022206
Ref: library/unittest unittest TestResult startTest14023166
Ref: 45ff14023166
Ref: library/unittest unittest TestResult stopTest14023265
Ref: 460014023265
Ref: library/unittest unittest TestResult startTestRun14023400
Ref: 155114023400
Ref: library/unittest unittest TestResult stopTestRun14023521
Ref: 155214023521
Ref: library/unittest unittest TestResult addError14023640
Ref: 1c3414023640
Ref: library/unittest unittest TestResult addFailure14024107
Ref: 1c3314024107
Ref: library/unittest unittest TestResult addSuccess14024565
Ref: 460414024565
Ref: library/unittest unittest TestResult addSkip14024707
Ref: 1c3514024707
Ref: library/unittest unittest TestResult addExpectedFailure14025003
Ref: 460514025003
Ref: library/unittest unittest TestResult addUnexpectedSuccess14025429
Ref: 460614025429
Ref: library/unittest unittest TestResult addSubTest14025735
Ref: 1c3614025735
Ref: library/unittest unittest TestResult addDuration14026409
Ref: 1a9f14026409
Ref: library/unittest unittest TextTestResult14026655
Ref: 75514026655
Ref: library/unittest unittest defaultTestLoader14027065
Ref: 45f114027065
Ref: library/unittest unittest TextTestRunner14027320
Ref: 1a9e14027320
Ref: library/unittest unittest TextTestRunner _makeResult14028754
Ref: 460814028754
Ref: library/unittest unittest TextTestRunner run14029405
Ref: 460914029405
Ref: library/unittest unittest main14029767
Ref: 11e514029767
Node: load_tests Protocol14032726
Ref: library/unittest id114032807
Ref: 45ca14032807
Ref: library/unittest load-tests-protocol14032807
Ref: 457014032807
Node: Class and Module Fixtures14035487
Ref: library/unittest class-and-module-fixtures14035638
Ref: 45d914035638
Node: setUpClass and tearDownClass14037539
Ref: library/unittest setupclass-and-teardownclass14037668
Ref: 460a14037668
Node: setUpModule and tearDownModule14038583
Ref: library/unittest setupmodule-and-teardownmodule14038712
Ref: 460b14038712
Ref: library/unittest unittest setUpModule14038795
Ref: c4414038795
Ref: library/unittest unittest addModuleCleanup14039326
Ref: c4214039326
Ref: library/unittest unittest enterModuleContext14039931
Ref: 8cc14039931
Ref: library/unittest unittest doModuleCleanups14040253
Ref: 1bbb14040253
Node: Signal Handling14040903
Ref: library/unittest signal-handling14041024
Ref: 45bc14041024
Ref: library/unittest unittest installHandler14042259
Ref: 460c14042259
Ref: library/unittest unittest registerResult14042503
Ref: 460d14042503
Ref: library/unittest unittest removeResult14042999
Ref: 460e14042999
Ref: library/unittest unittest removeHandler14043221
Ref: 153b14043221
Node: unittest mock — mock object library14043611
Ref: library/unittest mock doc14043788
Ref: 460f14043788
Ref: library/unittest mock module-unittest mock14043788
Ref: 10d14043788
Ref: library/unittest mock translation-repo14043788
Ref: 461014043788
Ref: library/unittest mock unittest-mock-mock-object-library14043788
Ref: 461114043788
Ref: unittest mock — mock object library-Footnote-114045450
Ref: unittest mock — mock object library-Footnote-214045523
Node: Quick Guide14045562
Ref: library/unittest mock quick-guide14045670
Ref: 461214045670
Node: The Mock Class14051084
Ref: library/unittest mock the-mock-class14051213
Ref: 461714051213
Ref: library/unittest mock unittest mock Mock14052247
Ref: c4114052247
Ref: library/unittest mock unittest mock Mock assert_called14055732
Ref: ef614055732
Ref: library/unittest mock unittest mock Mock assert_called_once14056024
Ref: ef714056024
Ref: library/unittest mock unittest mock Mock assert_called_with14056662
Ref: 1deb14056662
Ref: library/unittest mock unittest mock Mock assert_called_once_with14057046
Ref: 461d14057046
Ref: library/unittest mock unittest mock Mock assert_any_call14057727
Ref: 461e14057727
Ref: library/unittest mock unittest mock Mock assert_has_calls14058393
Ref: 1a0a14058393
Ref: library/unittest mock unittest mock Mock assert_not_called14059238
Ref: 109014059238
Ref: library/unittest mock unittest mock Mock reset_mock14059707
Ref: ef814059707
Ref: library/unittest mock unittest mock Mock mock_add_spec14061325
Ref: 462014061325
Ref: library/unittest mock unittest mock Mock attach_mock14061650
Ref: 193d14061650
Ref: library/unittest mock unittest mock Mock configure_mock14061943
Ref: 461c14061943
Ref: library/unittest mock unittest mock Mock __dir__14063177
Ref: 462214063177
Ref: library/unittest mock unittest mock Mock _get_child_mock14063510
Ref: 462414063510
Ref: library/unittest mock unittest mock Mock called14063910
Ref: 462514063910
Ref: library/unittest mock unittest mock Mock call_count14064210
Ref: 176a14064210
Ref: library/unittest mock unittest mock Mock return_value14064541
Ref: 461b14064541
Ref: library/unittest mock unittest mock Mock side_effect14065347
Ref: 461314065347
Ref: library/unittest mock unittest mock Mock call_args14067817
Ref: 1d5114067817
Ref: library/unittest mock unittest mock Mock call_args_list14069662
Ref: 462614069662
Ref: library/unittest mock unittest mock Mock method_calls14070705
Ref: 462114070705
Ref: library/unittest mock unittest mock Mock mock_calls14071443
Ref: 461f14071443
Ref: library/unittest mock unittest mock Mock __class__14072981
Ref: 462814072981
Ref: library/unittest mock unittest mock NonCallableMock14073740
Ref: 461814073740
Ref: library/unittest mock unittest mock PropertyMock14076266
Ref: 462914076266
Ref: library/unittest mock unittest mock AsyncMock14078170
Ref: c4014078170
Ref: library/unittest mock unittest mock AsyncMock assert_awaited14081039
Ref: 462a14081039
Ref: library/unittest mock unittest mock AsyncMock assert_awaited_once14081774
Ref: 462b14081774
Ref: library/unittest mock unittest mock AsyncMock assert_awaited_with14082332
Ref: 462c14082332
Ref: library/unittest mock unittest mock AsyncMock assert_awaited_once_with14083002
Ref: 462d14083002
Ref: library/unittest mock unittest mock AsyncMock assert_any_await14083727
Ref: 462e14083727
Ref: library/unittest mock unittest mock AsyncMock assert_has_awaits14084370
Ref: 462f14084370
Ref: library/unittest mock unittest mock AsyncMock assert_not_awaited14085465
Ref: 463014085465
Ref: library/unittest mock unittest mock AsyncMock reset_mock14085640
Ref: 463114085640
Ref: library/unittest mock unittest mock AsyncMock await_count14085871
Ref: 463214085871
Ref: library/unittest mock unittest mock AsyncMock await_args14086317
Ref: 463314086317
Ref: library/unittest mock unittest mock AsyncMock await_args_list14086936
Ref: 1d5014086936
Ref: library/unittest mock unittest mock ThreadingMock14087648
Ref: 463414087648
Ref: library/unittest mock unittest mock ThreadingMock wait_until_called14088357
Ref: 463614088357
Ref: library/unittest mock unittest mock ThreadingMock wait_until_any_call_with14088910
Ref: 463714088910
Ref: library/unittest mock unittest mock ThreadingMock DEFAULT_TIMEOUT14089509
Ref: 463514089509
Ref: The Mock Class-Footnote-114089834
Node: Calling14090256
Ref: library/unittest mock calling14090342
Ref: 463814090342
Node: Deleting Attributes14093612
Ref: library/unittest mock deleting-attributes14093740
Ref: 463914093740
Ref: library/unittest mock id214093740
Ref: 463a14093740
Node: Mock names and the name attribute14094515
Ref: library/unittest mock mock-names-and-the-name-attribute14094665
Ref: 463b14094665
Node: Attaching Mocks as Attributes14095249
Ref: library/unittest mock attaching-mocks-as-attributes14095371
Ref: 463c14095371
Node: The patchers14097232
Ref: library/unittest mock the-patchers14097384
Ref: 463d14097384
Node: patch14097999
Ref: library/unittest mock patch14098074
Ref: 463e14098074
Ref: library/unittest mock unittest mock patch14098221
Ref: 109414098221
Node: patch object14107195
Ref: library/unittest mock patch-object14107289
Ref: 464014107289
Ref: library/unittest mock unittest mock patch object14107334
Ref: 18ee14107334
Node: patch dict14108816
Ref: library/unittest mock patch-dict14108919
Ref: 464114108919
Ref: library/unittest mock unittest mock patch dict14108962
Ref: 194f14108962
Node: patch multiple14113190
Ref: library/unittest mock patch-multiple14113309
Ref: 464314113309
Ref: library/unittest mock unittest mock patch multiple14113360
Ref: 464414113360
Node: patch methods start and stop14116070
Ref: library/unittest mock patch-methods-start-and-stop14116193
Ref: 464514116193
Ref: library/unittest mock start-and-stop14116193
Ref: 464614116193
Ref: library/unittest mock unittest mock patch stopall14118939
Ref: 464714118939
Node: patch builtins14119048
Ref: library/unittest mock id414119168
Ref: 464814119168
Ref: library/unittest mock patch-builtins14119168
Ref: 464914119168
Node: TEST_PREFIX14119489
Ref: library/unittest mock id514119605
Ref: 464a14119605
Ref: library/unittest mock test-prefix14119605
Ref: 464214119605
Node: Nesting Patch Decorators14120488
Ref: library/unittest mock nesting-patch-decorators14120604
Ref: 464b14120604
Node: Where to patch14121521
Ref: library/unittest mock id614121664
Ref: 463f14121664
Ref: library/unittest mock where-to-patch14121664
Ref: 461414121664
Node: Patching Descriptors and Proxy Objects14123433
Ref: library/unittest mock patching-descriptors-and-proxy-objects14123543
Ref: 464c14123543
Ref: Patching Descriptors and Proxy Objects-Footnote-114123984
Node: MagicMock and magic method support14124109
Ref: library/unittest mock magicmock-and-magic-method-support14124254
Ref: 464d14124254
Node: Mocking Magic Methods14124396
Ref: library/unittest mock magic-methods14124507
Ref: 461514124507
Ref: library/unittest mock mocking-magic-methods14124507
Ref: 464e14124507
Ref: Mocking Magic Methods-Footnote-114128405
Ref: Mocking Magic Methods-Footnote-214128644
Node: Magic Mock14128765
Ref: library/unittest mock magic-mock14128876
Ref: 465014128876
Ref: library/unittest mock unittest mock MagicMock14129021
Ref: 109114129021
Ref: library/unittest mock unittest mock NonCallableMagicMock14129506
Ref: 461914129506
Node: Helpers14132851
Ref: library/unittest mock helpers14133041
Ref: 465114133041
Node: sentinel14133214
Ref: library/unittest mock sentinel14133282
Ref: 465214133282
Ref: library/unittest mock unittest mock sentinel14133321
Ref: d9b14133321
Node: DEFAULT14134487
Ref: library/unittest mock default14134568
Ref: 465314134568
Ref: library/unittest mock unittest mock DEFAULT14134605
Ref: 461a14134605
Node: call14134858
Ref: library/unittest mock call14134946
Ref: 465414134946
Ref: library/unittest mock unittest mock call14134977
Ref: 1d9b14134977
Ref: library/unittest mock unittest mock call call_list14135518
Ref: 465514135518
Ref: library/unittest mock calls-as-tuples14136468
Ref: 462714136468
Node: create_autospec14138092
Ref: library/unittest mock create-autospec14138176
Ref: 465614138176
Ref: library/unittest mock unittest mock create_autospec14138229
Ref: 191c14138229
Node: ANY14139535
Ref: library/unittest mock any14139625
Ref: 465714139625
Ref: library/unittest mock unittest mock ANY14139654
Ref: 1d9914139654
Node: FILTER_DIR14140816
Ref: library/unittest mock filter-dir14140900
Ref: 465814140900
Ref: library/unittest mock unittest mock FILTER_DIR14140943
Ref: 462314140943
Node: mock_open14142959
Ref: library/unittest mock mock-open14143052
Ref: 465914143052
Ref: library/unittest mock unittest mock mock_open14143093
Ref: 11e914143093
Ref: mock_open-Footnote-114145960
Node: Autospeccing14145985
Ref: library/unittest mock auto-speccing14146081
Ref: 461614146081
Ref: library/unittest mock autospeccing14146081
Ref: 465a14146081
Ref: Autospeccing-Footnote-114154804
Node: Sealing mocks14155045
Ref: library/unittest mock sealing-mocks14155123
Ref: 465b14155123
Ref: library/unittest mock unittest mock seal14155172
Ref: d9c14155172
Node: Order of precedence of side_effect return_value and wraps14155986
Ref: library/unittest mock order-of-precedence-of-side-effect-return-value-and-wraps14156133
Ref: 465c14156133
Node: unittest mock — getting started14160216
Ref: library/unittest mock-examples doc14160402
Ref: 465d14160402
Ref: library/unittest mock-examples translation-repo14160402
Ref: 465e14160402
Ref: library/unittest mock-examples unittest-mock-getting-started14160402
Ref: 465f14160402
Ref: library/unittest mock-examples getting-started14160514
Ref: 466014160514
Node: Using Mock14160581
Ref: library/unittest mock-examples using-mock14160686
Ref: 466114160686
Node: Mock Patching Methods14161151
Ref: library/unittest mock-examples mock-patching-methods14161262
Ref: 466214161262
Node: Mock for Method Calls on an Object14162818
Ref: library/unittest mock-examples mock-for-method-calls-on-an-object14162953
Ref: 466314162953
Node: Mocking Classes14164054
Ref: library/unittest mock-examples mocking-classes14164185
Ref: 466414164185
Node: Naming your mocks14165181
Ref: library/unittest mock-examples naming-your-mocks14165296
Ref: 466514165296
Node: Tracking all Calls14165728
Ref: library/unittest mock-examples tracking-all-calls14165864
Ref: 466614165864
Node: Setting Return Values and Attributes14167271
Ref: library/unittest mock-examples setting-return-values-and-attributes14167419
Ref: 466714167419
Node: Raising exceptions with mocks14168928
Ref: library/unittest mock-examples raising-exceptions-with-mocks14169093
Ref: 466814169093
Node: Side effect functions and iterables14169473
Ref: library/unittest mock-examples side-effect-functions-and-iterables14169632
Ref: 466914169632
Node: Mocking asynchronous iterators14170672
Ref: library/unittest mock-examples mocking-asynchronous-iterators14170838
Ref: 466a14170838
Node: Mocking asynchronous context manager14171411
Ref: library/unittest mock-examples mocking-asynchronous-context-manager14171581
Ref: 466b14171581
Node: Creating a Mock from an Existing Object14172482
Ref: library/unittest mock-examples creating-a-mock-from-an-existing-object14172666
Ref: 466c14172666
Node: Using side_effect to return per file content14174512
Ref: library/unittest mock-examples using-side-effect-to-return-per-file-content14174651
Ref: 466d14174651
Node: Patch Decorators14175502
Ref: library/unittest mock-examples patch-decorators14175632
Ref: 466e14175632
Node: Further Examples14180906
Ref: library/unittest mock-examples further-examples14181017
Ref: 466f14181017
Ref: library/unittest mock-examples id114181017
Ref: 467014181017
Node: Mocking chained calls14181645
Ref: library/unittest mock-examples mocking-chained-calls14181743
Ref: 467114181743
Node: Partial mocking14184856
Ref: library/unittest mock-examples partial-mocking14184989
Ref: 467214184989
Ref: Partial mocking-Footnote-114186985
Node: Mocking a Generator Method14187086
Ref: library/unittest mock-examples mocking-a-generator-method14187242
Ref: 467314187242
Ref: Mocking a Generator Method-Footnote-114188373
Node: Applying the same patch to every test method14188693
Ref: library/unittest mock-examples applying-the-same-patch-to-every-test-method14188857
Ref: 467414188857
Node: Mocking Unbound Methods14191154
Ref: library/unittest mock-examples mocking-unbound-methods14191325
Ref: 467514191325
Node: Checking multiple calls with mock14193096
Ref: library/unittest mock-examples checking-multiple-calls-with-mock14193252
Ref: 467614193252
Node: Coping with mutable arguments14194868
Ref: library/unittest mock-examples coping-with-mutable-arguments14195016
Ref: 467714195016
Node: Nesting Patches14199201
Ref: library/unittest mock-examples nesting-patches14199351
Ref: 467814199351
Node: Mocking a dictionary with MagicMock14201158
Ref: library/unittest mock-examples mocking-a-dictionary-with-magicmock14201315
Ref: 467914201315
Node: Mock subclasses and their attributes14203963
Ref: library/unittest mock-examples mock-subclasses-and-their-attributes14204136
Ref: 467a14204136
Ref: Mock subclasses and their attributes-Footnote-114206270
Ref: Mock subclasses and their attributes-Footnote-214206440
Ref: Mock subclasses and their attributes-Footnote-314206498
Node: Mocking imports with patch dict14206579
Ref: library/unittest mock-examples mocking-imports-with-patch-dict14206773
Ref: 467b14206773
Node: Tracking order of calls and less verbose call assertions14209419
Ref: library/unittest mock-examples tracking-order-of-calls-and-less-verbose-call-assertions14209607
Ref: 467c14209607
Node: More complex argument matching14212946
Ref: library/unittest mock-examples more-complex-argument-matching14213094
Ref: 467d14213094
Ref: More complex argument matching-Footnote-114216166
Ref: More complex argument matching-Footnote-214216209
Node: test — Regression tests package for Python14216331
Ref: library/test doc14216532
Ref: 467e14216532
Ref: library/test module-test14216532
Ref: e814216532
Ref: library/test test-regression-tests-package-for-python14216532
Ref: 467f14216532
Ref: library/test translation-repo14216532
Ref: 468014216532
Node: Writing Unit Tests for the test package14217967
Ref: library/test writing-tests14218142
Ref: 468114218142
Ref: library/test writing-unit-tests-for-the-test-package14218142
Ref: 468214218142
Node: Running tests using the command-line interface14222717
Ref: library/test module-test regrtest14222892
Ref: e914222892
Ref: library/test regrtest14222892
Ref: 120b14222892
Ref: library/test running-tests-using-the-command-line-interface14222892
Ref: 468314222892
Node: test support — Utilities for the Python test suite14224948
Ref: library/test module-test support14225173
Ref: ea14225173
Ref: library/test test-support-utilities-for-the-python-test-suite14225173
Ref: 468414225173
Ref: library/test test support TestFailed14225679
Ref: 468514225679
Ref: library/test test support ResourceDenied14225899
Ref: 468614225899
Ref: library/test test support verbose14226193
Ref: 468814226193
Ref: library/test test support is_jython14226413
Ref: 468914226413
Ref: library/test test support is_android14226502
Ref: 468a14226502
Ref: library/test test support is_emscripten14226594
Ref: 468b14226594
Ref: library/test test support is_wasi14226692
Ref: 468c14226692
Ref: library/test test support is_apple_mobile14226778
Ref: 468d14226778
Ref: library/test test support is_apple14226901
Ref: 468e14226901
Ref: library/test test support unix_shell14227034
Ref: 468f14227034
Ref: library/test test support LOOPBACK_TIMEOUT14227131
Ref: 1d8414227131
Ref: library/test test support INTERNET_TIMEOUT14227724
Ref: 1d8514227724
Ref: library/test test support SHORT_TIMEOUT14228220
Ref: 1c4b14228220
Ref: library/test test support LONG_TIMEOUT14228610
Ref: 1d8614228610
Ref: library/test test support PGO14229117
Ref: 469114229117
Ref: library/test test support PIPE_MAX_SIZE14229215
Ref: 469214229215
Ref: library/test test support Py_DEBUG14229363
Ref: 469314229363
Ref: library/test test support SOCK_MAX_SIZE14229568
Ref: 469414229568
Ref: library/test test support TEST_SUPPORT_DIR14229718
Ref: 469514229718
Ref: library/test test support TEST_HOME_DIR14229839
Ref: 469614229839
Ref: library/test test support TEST_DATA_DIR14229936
Ref: 469714229936
Ref: library/test test support MAX_Py_ssize_t14230037
Ref: 469814230037
Ref: library/test test support max_memuse14230136
Ref: 469914230136
Ref: library/test test support real_max_memuse14230299
Ref: 469b14230299
Ref: library/test test support MISSING_C_DOCSTRINGS14230471
Ref: 469c14230471
Ref: library/test test support HAVE_DOCSTRINGS14230758
Ref: 469d14230758
Ref: library/test test support TEST_HTTP_URL14231033
Ref: 469e14231033
Ref: library/test test support ALWAYS_EQ14231142
Ref: 469f14231142
Ref: library/test test support NEVER_EQ14231258
Ref: 46a014231258
Ref: library/test test support LARGEST14231410
Ref: 46a114231410
Ref: library/test test support SMALLEST14231544
Ref: 46a214231544
Ref: library/test test support busy_retry14231745
Ref: 46a314231745
Ref: library/test test support sleeping_retry14232387
Ref: 46a414232387
Ref: library/test test support is_resource_enabled14233271
Ref: 46a514233271
Ref: library/test test support get_resource_value14233503
Ref: 46a614233503
Ref: library/test test support python_is_optimized14233714
Ref: 46a714233714
Ref: library/test test support with_pymalloc14233842
Ref: 46a814233842
Ref: library/test test support requires14233931
Ref: 468714233931
Ref: library/test test support sortdict14234302
Ref: 46a914234302
Ref: library/test test support findfile14234394
Ref: 46aa14234394
Ref: library/test test support get_pagesize14234766
Ref: 46ab14234766
Ref: library/test test support setswitchinterval14234874
Ref: 46ac14234874
Ref: library/test test support check_impl_detail14235100
Ref: 46ad14235100
Ref: library/test test support set_memlimit14235618
Ref: 469a14235618
Ref: library/test test support record_original_stdout14235776
Ref: 46ae14235776
Ref: library/test test support get_original_stdout14235942
Ref: 46af14235942
Ref: library/test test support args_from_interpreter_flags14236115
Ref: 46b014236115
Ref: library/test test support optim_args_from_interpreter_flags14236304
Ref: 46b114236304
Ref: library/test test support captured_stdin14236486
Ref: 46b214236486
Ref: library/test test support captured_stdout14236531
Ref: 46b314236531
Ref: library/test test support captured_stderr14236577
Ref: 1dc014236577
Ref: library/test test support disable_faulthandler14237303
Ref: 46b414237303
Ref: library/test test support gc_collect14237427
Ref: 46b514237427
Ref: library/test test support disable_gc14237763
Ref: 46b614237763
Ref: library/test test support swap_attr14237944
Ref: 46b714237944
Ref: library/test test support swap_item14238528
Ref: 46b814238528
Ref: library/test test support flush_std_streams14239110
Ref: 46b914239110
Ref: library/test test support print_warning14239386
Ref: 46ba14239386
Ref: library/test test support wait_process14239660
Ref: 1d4514239660
Ref: library/test test support calcobjsize14240179
Ref: 46bc14240179
Ref: library/test test support calcvobjsize14240412
Ref: 46bd14240412
Ref: library/test test support checksizeof14240650
Ref: 46bf14240650
Ref: library/test test support anticipate_failure14240821
Ref: 46c014240821
Ref: library/test test support system_must_validate_cert14241083
Ref: 46c114241083
Ref: library/test test support run_with_locale14241236
Ref: 46c214241236
Ref: library/test test support run_with_tz14241596
Ref: 46c314241596
Ref: library/test test support requires_freebsd_version14241758
Ref: 46c414241758
Ref: library/test test support requires_linux_version14241972
Ref: 46c514241972
Ref: library/test test support requires_mac_version14242181
Ref: 46c614242181
Ref: library/test test support requires_gil_enabled14242387
Ref: 46c714242387
Ref: library/test test support requires_IEEE_75414242563
Ref: 46c814242563
Ref: library/test test support requires_zlib14242672
Ref: 46c914242672
Ref: library/test test support requires_gzip14242787
Ref: 46ca14242787
Ref: library/test test support requires_bz214242901
Ref: 46cb14242901
Ref: library/test test support requires_lzma14243013
Ref: 46cc14243013
Ref: library/test test support requires_resource14243127
Ref: 46cd14243127
Ref: library/test test support requires_docstrings14243252
Ref: 46ce14243252
Ref: library/test test support requires_limited_api14243375
Ref: 46cf14243375
Ref: library/test test support cpython_only14243515
Ref: 46d014243515
Ref: library/test test support impl_detail14243611
Ref: 46d114243611
Ref: library/test test support thread_unsafe14243841
Ref: 46d214243841
Ref: library/test test support no_tracing14244041
Ref: 46d314244041
Ref: library/test test support refcount_test14244164
Ref: 46d414244164
Ref: library/test test support bigmemtest14244468
Ref: 46d514244468
Ref: library/test test support bigaddrspacetest14245215
Ref: 46d614245215
Ref: library/test test support linked_to_musl14245316
Ref: 46d714245316
Ref: library/test test support check_syntax_error14245771
Ref: 46d814245771
Ref: library/test test support open_urlresource14246325
Ref: 46d914246325
Ref: library/test test support reap_children14246454
Ref: 46da14246454
Ref: library/test test support get_attribute14246728
Ref: 46db14246728
Ref: library/test test support catch_unraisable_exception14246891
Ref: 1da514246891
Ref: library/test test support load_package_tests14247779
Ref: 46dc14247779
Ref: library/test test support detect_api_mismatch14248409
Ref: 46dd14248409
Ref: library/test test support patch14248880
Ref: 46de14248880
Ref: library/test test support run_in_subinterp14249216
Ref: 46df14249216
Ref: library/test test support check_free_after_iterating14249386
Ref: 46e014249386
Ref: library/test test support missing_compiler_executable14249543
Ref: 46e114249543
Ref: library/test test support check__all__14249865
Ref: 1d1b14249865
Ref: library/test test support skip_if_broken_multiprocessing_synchronize14251683
Ref: 1d1c14251683
Ref: library/test test support check_disallow_instantiation14251976
Ref: 46e214251976
Ref: library/test test support adjust_int_max_str_digits14252184
Ref: 46e314252184
Ref: library/test test support SuppressCrashReport14252655
Ref: 46e414252655
Ref: library/test test support SaveSignals14253159
Ref: 46e614253159
Ref: library/test test support SaveSignals save14253291
Ref: 46e714253291
Ref: library/test test support SaveSignals restore14253437
Ref: 46e814253437
Ref: library/test test support Matcher14253576
Ref: 46e914253576
Ref: library/test test support Matcher matches14253610
Ref: 46ea14253610
Ref: library/test test support Matcher match_value14253723
Ref: 46eb14253723
Ref: test support — Utilities for the Python test suite-Footnote-114253898
Node: test support socket_helper — Utilities for socket tests14253978
Ref: library/test module-test support socket_helper14254230
Ref: ef14254230
Ref: library/test test-support-socket-helper-utilities-for-socket-tests14254230
Ref: 46ec14254230
Ref: library/test test support socket_helper IPV6_ENABLED14254477
Ref: 46ed14254477
Ref: library/test test support socket_helper find_unused_port14254608
Ref: 46ee14254608
Ref: library/test test support socket_helper bind_port14255931
Ref: 46ef14255931
Ref: library/test test support socket_helper bind_unix_socket14256876
Ref: 46f014256876
Ref: library/test test support socket_helper skip_unless_bind_unix_socket14257060
Ref: 46f114257060
Ref: library/test test support socket_helper transient_internet14257230
Ref: 469014257230
Node: test support script_helper — Utilities for the Python execution tests14257503
Ref: library/test module-test support script_helper14257789
Ref: ee14257789
Ref: library/test test-support-script-helper-utilities-for-the-python-execution-tests14257789
Ref: 46f214257789
Ref: library/test test support script_helper interpreter_requires_environment14258062
Ref: 46f314258062
Ref: library/test test support script_helper run_python_until_end14259038
Ref: 46f414259038
Ref: library/test test support script_helper assert_python_ok14259421
Ref: 46f514259421
Ref: library/test test support script_helper assert_python_failure14260059
Ref: 46f614260059
Ref: library/test test support script_helper spawn_python14260498
Ref: 46f714260498
Ref: library/test test support script_helper kill_python14260811
Ref: 46f814260811
Ref: library/test test support script_helper make_script14260967
Ref: 46f914260967
Ref: library/test test support script_helper make_zip_script14261276
Ref: 46fa14261276
Ref: library/test test support script_helper make_pkg14261645
Ref: 46fb14261645
Ref: library/test test support script_helper make_zip_pkg14261848
Ref: 46fc14261848
Node: test support bytecode_helper — Support tools for testing correct bytecode generation14262378
Ref: library/test module-test support bytecode_helper14262670
Ref: eb14262670
Ref: library/test test-support-bytecode-helper-support-tools-for-testing-correct-bytecode-generation14262670
Ref: 46fd14262670
Ref: library/test test support bytecode_helper BytecodeTestCase14263048
Ref: 46fe14263048
Ref: library/test test support bytecode_helper BytecodeTestCase get_disassembly_as_string14263208
Ref: 46ff14263208
Ref: library/test test support bytecode_helper BytecodeTestCase assertInBytecode14263317
Ref: 470014263317
Ref: library/test test support bytecode_helper BytecodeTestCase assertNotInBytecode14263497
Ref: 470114263497
Node: test support threading_helper — Utilities for threading tests14263652
Ref: library/test module-test support threading_helper14263922
Ref: f014263922
Ref: library/test test-support-threading-helper-utilities-for-threading-tests14263922
Ref: 470214263922
Ref: library/test test support threading_helper join_thread14264188
Ref: 470314264188
Ref: library/test test support threading_helper reap_threads14264410
Ref: 470414264410
Ref: library/test test support threading_helper start_threads14264551
Ref: 470514264551
Ref: library/test test support threading_helper threading_cleanup14264959
Ref: 470614264959
Ref: library/test test support threading_helper threading_setup14265197
Ref: 470714265197
Ref: library/test test support threading_helper wait_threads_exit14265325
Ref: 470814265325
Ref: library/test test support threading_helper catch_threading_exception14265508
Ref: 470914265508
Ref: library/test test support threading_helper run_concurrently14266469
Ref: 470a14266469
Node: test support os_helper — Utilities for os tests14266741
Ref: library/test module-test support os_helper14266982
Ref: ed14266982
Ref: library/test test-support-os-helper-utilities-for-os-tests14266982
Ref: 470b14266982
Ref: library/test test support os_helper FS_NONASCII14267206
Ref: 470c14267206
Ref: library/test test support os_helper SAVEDCWD14267319
Ref: 470d14267319
Ref: library/test test support os_helper TESTFN14267400
Ref: 470e14267400
Ref: library/test test support os_helper TESTFN_NONASCII14267600
Ref: 470f14267600
Ref: library/test test support os_helper TESTFN_UNENCODABLE14267985
Ref: 471014267985
Ref: library/test test support os_helper TESTFN_UNDECODABLE14268235
Ref: 471114268235
Ref: library/test test support os_helper TESTFN_UNICODE14268487
Ref: 471214268487
Ref: library/test test support os_helper EnvironmentVarGuard14268588
Ref: 15e914268588
Ref: library/test test support os_helper FakePath14269062
Ref: 471314269062
Ref: library/test test support os_helper EnvironmentVarGuard set14269325
Ref: 471414269325
Ref: library/test test support os_helper EnvironmentVarGuard unset14269472
Ref: 185a14269472
Ref: library/test test support os_helper can_symlink14269678
Ref: 471514269678
Ref: library/test test support os_helper can_xattr14269813
Ref: 471614269813
Ref: library/test test support os_helper change_cwd14269937
Ref: 471714269937
Ref: library/test test support os_helper create_empty_file14270306
Ref: 471814270306
Ref: library/test test support os_helper fd_count14270458
Ref: 471914270458
Ref: library/test test support os_helper fs_is_case_insensitive14270557
Ref: 471a14270557
Ref: library/test test support os_helper make_bad_fd14270715
Ref: 471b14270715
Ref: library/test test support os_helper rmdir14270884
Ref: 471c14270884
Ref: library/test test support os_helper rmtree14271192
Ref: 471d14271192
Ref: library/test test support os_helper skip_unless_symlink14271535
Ref: 471e14271535
Ref: library/test test support os_helper skip_unless_xattr14271676
Ref: 471f14271676
Ref: library/test test support os_helper temp_cwd14271801
Ref: 472014271801
Ref: library/test test support os_helper temp_dir14272458
Ref: 472114272458
Ref: library/test test support os_helper temp_umask14272910
Ref: 472214272910
Ref: library/test test support os_helper unlink14273032
Ref: 472314273032
Node: test support import_helper — Utilities for import tests14273277
Ref: library/test module-test support import_helper14273516
Ref: ec14273516
Ref: library/test test-support-import-helper-utilities-for-import-tests14273516
Ref: 472414273516
Ref: library/test test support import_helper forget14273764
Ref: 472514273764
Ref: library/test test support import_helper import_fresh_module14273949
Ref: 1c4a14273949
Ref: library/test test support import_helper import_module14275566
Ref: 472614275566
Ref: library/test test support import_helper modules_setup14276188
Ref: 472714276188
Ref: library/test test support import_helper modules_cleanup14276295
Ref: 472814276295
Ref: library/test test support import_helper unload14276473
Ref: 472914276473
Ref: library/test test support import_helper make_legacy_pyc14276573
Ref: 472a14276573
Ref: library/test test support import_helper CleanImport14276922
Ref: 472b14276922
Ref: library/test test support import_helper DirsOnSysPath14277313
Ref: 472c14277313
Ref: test support import_helper — Utilities for import tests-Footnote-114277871
Ref: test support import_helper — Utilities for import tests-Footnote-214277913
Node: test support warnings_helper — Utilities for warnings tests14277955
Ref: library/test module-test support warnings_helper14278136
Ref: f114278136
Ref: library/test test-support-warnings-helper-utilities-for-warnings-tests14278136
Ref: 472d14278136
Ref: library/test test support warnings_helper ignore_warnings14278396
Ref: 472e14278396
Ref: library/test test support warnings_helper check_no_resource_warning14278909
Ref: 472f14278909
Ref: library/test test support warnings_helper check_syntax_warning14279199
Ref: 473014279199
Ref: library/test test support warnings_helper check_warnings14280018
Ref: 473114280018
Ref: library/test test support warnings_helper WarningsRecorder14283093
Ref: 473214283093
Node: Debugging and Profiling14283285
Ref: library/debug doc14283442
Ref: 473314283442
Ref: library/debug debugging-and-profiling14283442
Ref: 473414283442
Ref: library/debug translation-repo14283442
Ref: 473514283442
Ref: library/audit_events audit-events14283902
Ref: 1bfb14283902
Node: Audit events table14284232
Ref: library/audit_events doc14284345
Ref: 473614284345
Ref: library/audit_events audit-events-table14284345
Ref: 473714284345
Ref: Audit events table-Footnote-114344740
Node: bdb — Debugger framework14344782
Ref: library/bdb doc14344946
Ref: 475914344946
Ref: library/bdb bdb-debugger-framework14344946
Ref: 475a14344946
Ref: library/bdb module-bdb14344946
Ref: 1014344946
Ref: library/bdb translation-repo14344946
Ref: 475b14344946
Ref: library/bdb bdb BdbQuit14345282
Ref: 27814345282
Ref: library/bdb bdb Breakpoint14345447
Ref: 475c14345447
Ref: library/bdb bdb Breakpoint deleteMe14346402
Ref: 476314346402
Ref: library/bdb bdb Breakpoint enable14346618
Ref: 476414346618
Ref: library/bdb bdb Breakpoint disable14346689
Ref: 476514346689
Ref: library/bdb bdb Breakpoint bpformat14346762
Ref: 476614346762
Ref: library/bdb bdb Breakpoint bpprint14347159
Ref: 476714347159
Ref: library/bdb bdb Breakpoint file14347395
Ref: 475f14347395
Ref: library/bdb bdb Breakpoint line14347473
Ref: 476814347473
Ref: library/bdb bdb Breakpoint temporary14347588
Ref: 476914347588
Ref: library/bdb bdb Breakpoint cond14347710
Ref: 476214347710
Ref: library/bdb bdb Breakpoint funcname14347825
Ref: 476014347825
Ref: library/bdb bdb Breakpoint enabled14347972
Ref: 476a14347972
Ref: library/bdb bdb Breakpoint bpbynumber14348062
Ref: 475d14348062
Ref: library/bdb bdb Breakpoint bplist14348180
Ref: 475e14348180
Ref: library/bdb bdb Breakpoint ignore14348334
Ref: 476b14348334
Ref: library/bdb bdb Breakpoint hits14348425
Ref: 476114348425
Ref: library/bdb bdb Bdb14348541
Ref: 2d514348541
Ref: library/bdb bdb Bdb canonic14350079
Ref: 476c14350079
Ref: library/bdb bdb Bdb start_trace14350458
Ref: 476d14350458
Ref: library/bdb bdb Bdb stop_trace14350665
Ref: 476e14350665
Ref: library/bdb bdb Bdb reset14350855
Ref: 476f14350855
Ref: library/bdb bdb Bdb trace_dispatch14351047
Ref: 477114351047
Ref: library/bdb bdb Bdb dispatch_line14352465
Ref: 477214352465
Ref: library/bdb bdb Bdb dispatch_call14352941
Ref: 477414352941
Ref: library/bdb bdb Bdb dispatch_return14353424
Ref: 477614353424
Ref: library/bdb bdb Bdb dispatch_exception14353915
Ref: 477814353915
Ref: library/bdb bdb Bdb is_skipped_module14354573
Ref: 477a14354573
Ref: library/bdb bdb Bdb stop_here14354695
Ref: 477b14354695
Ref: library/bdb bdb Bdb break_here14354823
Ref: 477c14354823
Ref: library/bdb bdb Bdb break_anywhere14355131
Ref: 477e14355131
Ref: library/bdb bdb Bdb user_call14355350
Ref: 477514355350
Ref: library/bdb bdb Bdb user_line14355651
Ref: 477314355651
Ref: library/bdb bdb Bdb user_return14355845
Ref: 477714355845
Ref: library/bdb bdb Bdb user_exception14356011
Ref: 477914356011
Ref: library/bdb bdb Bdb do_clear14356179
Ref: 477f14356179
Ref: library/bdb bdb Bdb set_step14356464
Ref: 478014356464
Ref: library/bdb bdb Bdb set_next14356534
Ref: 478114356534
Ref: library/bdb bdb Bdb set_return14356631
Ref: 478214356631
Ref: library/bdb bdb Bdb set_until14356721
Ref: 478314356721
Ref: library/bdb bdb Bdb set_trace14356906
Ref: 478414356906
Ref: library/bdb bdb Bdb set_continue14357241
Ref: 478614357241
Ref: library/bdb bdb Bdb set_quit14357414
Ref: 477014357414
Ref: library/bdb bdb Bdb set_break14357831
Ref: 478714357831
Ref: library/bdb bdb Bdb clear_break14358196
Ref: 478814358196
Ref: library/bdb bdb Bdb clear_bpbynumber14358361
Ref: 478914358361
Ref: library/bdb bdb Bdb clear_all_file_breaks14358590
Ref: 478a14358590
Ref: library/bdb bdb Bdb clear_all_breaks14358744
Ref: 478b14358744
Ref: library/bdb bdb Bdb get_bpbynumber14358880
Ref: 478c14358880
Ref: library/bdb bdb Bdb get_break14359231
Ref: 478d14359231
Ref: library/bdb bdb Bdb get_breaks14359370
Ref: 478e14359370
Ref: library/bdb bdb Bdb get_file_breaks14359524
Ref: 478f14359524
Ref: library/bdb bdb Bdb get_all_breaks14359662
Ref: 479014359662
Ref: library/bdb bdb Bdb disable_current_event14359950
Ref: 479114359950
Ref: library/bdb bdb Bdb restart_events14360219
Ref: 479214360219
Ref: library/bdb bdb Bdb get_stack14360721
Ref: 479314360721
Ref: library/bdb bdb Bdb format_stack_entry14361012
Ref: 479414361012
Ref: library/bdb bdb Bdb run14361595
Ref: 479514361595
Ref: library/bdb bdb Bdb runeval14361825
Ref: 479614361825
Ref: library/bdb bdb Bdb runctx14362053
Ref: 479714362053
Ref: library/bdb bdb Bdb runcall14362189
Ref: c7314362189
Ref: library/bdb bdb checkfuncname14362358
Ref: 479814362358
Ref: library/bdb bdb effective14362811
Ref: 477d14362811
Ref: library/bdb bdb set_trace14363579
Ref: 478514363579
Ref: bdb — Debugger framework-Footnote-114363729
Node: faulthandler — Dump the Python traceback14363792
Ref: library/faulthandler doc14363965
Ref: 479914363965
Ref: library/faulthandler faulthandler-dump-the-python-traceback14363965
Ref: 479a14363965
Ref: library/faulthandler module-faulthandler14363965
Ref: 5c14363965
Ref: library/faulthandler translation-repo14363965
Ref: 479b14363965
Node: Dumping the traceback14366393
Ref: library/faulthandler dumping-the-traceback14366521
Ref: 479c14366521
Ref: library/faulthandler faulthandler dump_traceback14366584
Ref: 100114366584
Node: Dumping the C stack14367021
Ref: library/faulthandler dumping-the-c-stack14367177
Ref: 479d14367177
Ref: library/faulthandler faulthandler dump_c_stack14367260
Ref: 20e14367260
Node: C Stack Compatibility14367587
Ref: library/faulthandler c-stack-compatibility14367664
Ref: 20d14367664
Ref: library/faulthandler id114367664
Ref: 479e14367664
Ref: C Stack Compatibility-Footnote-114368283
Ref: C Stack Compatibility-Footnote-214368332
Node: Fault handler state14368379
Ref: library/faulthandler fault-handler-state14368552
Ref: 479f14368552
Ref: library/faulthandler faulthandler enable14368611
Ref: 20f14368611
Ref: library/faulthandler faulthandler disable14369970
Ref: 47a114369970
Ref: library/faulthandler faulthandler is_enabled14370111
Ref: 47a214370111
Node: Dumping the tracebacks after a timeout14370198
Ref: library/faulthandler dumping-the-tracebacks-after-a-timeout14370390
Ref: 47a314370390
Ref: library/faulthandler faulthandler dump_traceback_later14370487
Ref: 100214370487
Ref: library/faulthandler faulthandler cancel_dump_traceback_later14371529
Ref: 47a414371529
Node: Dumping the traceback on a user signal14371654
Ref: library/faulthandler dumping-the-traceback-on-a-user-signal14371854
Ref: 47a514371854
Ref: library/faulthandler faulthandler register14371951
Ref: 100014371951
Ref: library/faulthandler faulthandler unregister14372587
Ref: 47a614372587
Node: Issue with file descriptors14372863
Ref: library/faulthandler faulthandler-fd14373036
Ref: 47a014373036
Ref: library/faulthandler issue-with-file-descriptors14373036
Ref: 47a714373036
Node: Example<13>14373506
Ref: library/faulthandler example14373632
Ref: 47a814373632
Node: pdb — The Python Debugger14376893
Ref: library/pdb doc14377060
Ref: 47a914377060
Ref: library/pdb debugger14377060
Ref: 47aa14377060
Ref: library/pdb module-pdb14377060
Ref: aa14377060
Ref: library/pdb pdb-the-python-debugger14377060
Ref: 47ab14377060
Ref: library/pdb translation-repo14377060
Ref: 47ac14377060
Ref: pdb — The Python Debugger-Footnote-114379291
Node: Command-line interface<8>14379354
Ref: library/pdb command-line-interface14379469
Ref: 47ae14379469
Ref: library/pdb pdb-cli14379469
Ref: 2e214379469
Ref: library/pdb cmdoption-pdb-c14380079
Ref: 47af14380079
Ref: library/pdb cmdoption-pdb-command14380079
Ref: 47b014380079
Ref: library/pdb cmdoption-pdb-m14380280
Ref: 47b214380280
Ref: library/pdb cmdoption-pdb-p14380538
Ref: 27014380538
Ref: library/pdb cmdoption-pdb-pid14380538
Ref: 47b314380538
Ref: library/pdb pdb run14381918
Ref: 45a314381918
Ref: library/pdb pdb runeval14382610
Ref: 47b614382610
Ref: library/pdb pdb runcall14382923
Ref: 47b714382923
Ref: library/pdb pdb set_trace14383238
Ref: 27214383238
Ref: library/pdb pdb set_trace_async14383988
Ref: 27914383988
Ref: library/pdb pdb post_mortem14384401
Ref: 15e114384401
Ref: library/pdb pdb pm14384754
Ref: 54014384754
Ref: library/pdb pdb set_default_backend14384869
Ref: 47b814384869
Ref: library/pdb pdb get_default_backend14385431
Ref: 47b914385431
Ref: library/pdb pdb Pdb14385767
Ref: 27314385767
Ref: library/pdb pdb Pdb run14388429
Ref: 47ba14388429
Ref: library/pdb pdb Pdb runeval14388489
Ref: 47bb14388489
Ref: library/pdb pdb Pdb runcall14388554
Ref: 47bc14388554
Ref: library/pdb pdb Pdb set_trace14388605
Ref: 27414388605
Ref: Command-line interface<8>-Footnote-114388740
Ref: Command-line interface<8>-Footnote-214388782
Node: Debugger commands14388911
Ref: library/pdb debugger-commands14389026
Ref: 47b114389026
Ref: library/pdb id214389026
Ref: 47bd14389026
Ref: library/pdb pdbcommand-help14392691
Ref: 47c014392691
Ref: library/pdb pdbcommand-where14393084
Ref: 47c114393084
Ref: library/pdb pdbcommand-down14393548
Ref: 47c214393548
Ref: library/pdb pdbcommand-up14393687
Ref: 47c314393687
Ref: library/pdb pdbcommand-break14393823
Ref: 47c414393823
Ref: library/pdb pdbcommand-tbreak14394948
Ref: 47c514394948
Ref: library/pdb pdbcommand-clear14395159
Ref: 47c614395159
Ref: library/pdb pdbcommand-disable14395456
Ref: 47c714395456
Ref: library/pdb pdbcommand-enable14395779
Ref: 47c814395779
Ref: library/pdb pdbcommand-ignore14395867
Ref: 47c914395867
Ref: library/pdb pdbcommand-condition14396269
Ref: 47ca14396269
Ref: library/pdb pdbcommand-commands14396562
Ref: 27614396562
Ref: library/pdb pdbcommand-step14398228
Ref: 47b414398228
Ref: library/pdb pdbcommand-next14398413
Ref: 47b514398413
Ref: library/pdb pdbcommand-until14398811
Ref: 47cc14398811
Ref: library/pdb pdbcommand-return14399212
Ref: 47cb14399212
Ref: library/pdb pdbcommand-continue14399299
Ref: 47ad14399299
Ref: library/pdb pdbcommand-jump14399399
Ref: 47cd14399399
Ref: library/pdb pdbcommand-list14399829
Ref: 47be14399829
Ref: library/pdb pdbcommand-ll14400582
Ref: 47cf14400582
Ref: library/pdb pdbcommand-args14400762
Ref: 47d014400762
Ref: library/pdb pdbcommand-p14400867
Ref: 117814400867
Ref: library/pdb pdbcommand-pp14401128
Ref: 47d114401128
Ref: library/pdb pdbcommand-whatis14401290
Ref: 47d214401290
Ref: library/pdb pdbcommand-source14401363
Ref: 47d314401363
Ref: library/pdb pdbcommand-display14401487
Ref: 27514401487
Ref: library/pdb pdbcommand-undisplay14402940
Ref: 47d414402940
Ref: library/pdb pdbcommand-interact14403153
Ref: 47d514403153
Ref: library/pdb debugger-aliases14404071
Ref: 47bf14404071
Ref: library/pdb pdbcommand-alias14404071
Ref: 47d614404071
Ref: library/pdb pdbcommand-unalias14405180
Ref: 47d714405180
Ref: library/pdb pdbcommand-014405251
Ref: 47d814405251
Ref: library/pdb pdbcommand-run14405738
Ref: 47d914405738
Ref: library/pdb pdbcommand-restart14405769
Ref: 47da14405769
Ref: library/pdb pdbcommand-quit14406267
Ref: 47ce14406267
Ref: library/pdb pdbcommand-debug14406897
Ref: 47db14406897
Ref: library/pdb pdbcommand-retval14407085
Ref: 47dc14407085
Ref: library/pdb pdbcommand-exceptions14407183
Ref: 54114407183
Node: The Python Profilers14408510
Ref: library/profile doc14408691
Ref: 47dd14408691
Ref: library/profile profile14408691
Ref: 47de14408691
Ref: library/profile the-python-profilers14408691
Ref: 47df14408691
Ref: library/profile translation-repo14408691
Ref: 47e014408691
Ref: The Python Profilers-Footnote-114409135
Ref: The Python Profilers-Footnote-214409202
Node: Introduction to the profilers14409268
Ref: library/profile introduction-to-the-profilers14409386
Ref: 47e114409386
Ref: library/profile profiler-introduction14409386
Ref: 47e214409386
Node: Instant User’s Manual14410871
Ref: library/profile instant-user-s-manual14411035
Ref: 47e314411035
Ref: library/profile profile-instant14411035
Ref: 47e414411035
Ref: library/profile profile-cli14413913
Ref: 47e614413913
Ref: library/profile cmdoption-cProfile-o14414126
Ref: 47e714414126
Ref: library/profile cmdoption-cProfile-s14414221
Ref: 47e814414221
Ref: library/profile cmdoption-cProfile-m14414405
Ref: 47ea14414405
Node: profile and cProfile Module Reference14417333
Ref: library/profile module-cProfile14417483
Ref: 2b14417483
Ref: library/profile profile-and-cprofile-module-reference14417483
Ref: 47ed14417483
Ref: library/profile module-profile14417594
Ref: b414417594
Ref: library/profile profile run14417688
Ref: 47ee14417688
Ref: library/profile profile runctx14418323
Ref: 47ef14418323
Ref: library/profile profile Profile14418720
Ref: bd814418720
Ref: library/profile profile Profile enable14420304
Ref: 47f014420304
Ref: library/profile profile Profile disable14420405
Ref: 47f114420405
Ref: library/profile profile Profile create_stats14420506
Ref: 47f214420506
Ref: library/profile profile Profile print_stats14420650
Ref: 47f314420650
Ref: library/profile profile Profile dump_stats14421138
Ref: 47f414421138
Ref: library/profile profile Profile run14421245
Ref: 47f514421245
Ref: library/profile profile Profile runctx14421323
Ref: 47f614421323
Ref: library/profile profile Profile runcall14421480
Ref: c7214421480
Node: The Stats Class14421824
Ref: library/profile profile-stats14421983
Ref: 47f714421983
Ref: library/profile the-stats-class14421983
Ref: 47f814421983
Ref: library/profile module-pstats14422117
Ref: b514422117
Ref: library/profile pstats Stats14422117
Ref: 47e514422117
Ref: library/profile pstats Stats strip_dirs14423379
Ref: 47eb14423379
Ref: library/profile pstats Stats add14424199
Ref: 47f914424199
Ref: library/profile pstats Stats dump_stats14424692
Ref: 47fa14424692
Ref: library/profile pstats Stats sort_stats14425073
Ref: 47e914425073
Ref: library/profile pstats Stats reverse_order14430432
Ref: 47fb14430432
Ref: library/profile pstats Stats print_stats14430718
Ref: 47ec14430718
Ref: library/profile pstats Stats print_callers14432165
Ref: 47fc14432165
Ref: library/profile pstats Stats print_callees14433281
Ref: 47fd14433281
Ref: library/profile pstats Stats get_stats_profile14433662
Ref: 47fe14433662
Node: What Is Deterministic Profiling?14434209
Ref: library/profile deterministic-profiling14434342
Ref: 47ff14434342
Ref: library/profile what-is-deterministic-profiling14434342
Ref: 480014434342
Node: Limitations14436138
Ref: library/profile limitations14436267
Ref: 480114436267
Ref: library/profile profile-limitations14436267
Ref: 480214436267
Node: Calibration14438144
Ref: library/profile calibration14438261
Ref: 480314438261
Ref: library/profile profile-calibration14438261
Ref: 480414438261
Node: Using a custom timer14439951
Ref: library/profile profile-timers14440048
Ref: 480514440048
Ref: library/profile using-a-custom-timer14440048
Ref: 480614440048
Node: timeit — Measure execution time of small code snippets14442499
Ref: library/timeit doc14442704
Ref: 480714442704
Ref: library/timeit module-timeit14442704
Ref: f514442704
Ref: library/timeit timeit-measure-execution-time-of-small-code-snippets14442704
Ref: 480814442704
Ref: library/timeit translation-repo14442704
Ref: 480914442704
Ref: timeit — Measure execution time of small code snippets-Footnote-114443487
Node: Basic Examples<2>14443553
Ref: library/timeit basic-examples14443688
Ref: 480c14443688
Node: Python Interface14444974
Ref: library/timeit id114445143
Ref: 480e14445143
Ref: library/timeit python-interface14445143
Ref: 480b14445143
Ref: library/timeit timeit timeit14445264
Ref: 108014445264
Ref: library/timeit timeit repeat14445737
Ref: 480f14445737
Ref: library/timeit timeit default_timer14446342
Ref: 481114446342
Ref: library/timeit timeit Timer14446642
Ref: 16cf14446642
Ref: library/timeit timeit Timer timeit14448100
Ref: eeb14448100
Ref: library/timeit timeit Timer autorange14449225
Ref: eea14449225
Ref: library/timeit timeit Timer repeat14449955
Ref: 481014449955
Ref: library/timeit timeit Timer print_exc14451236
Ref: 481214451236
Node: Command-Line Interface<3>14451816
Ref: library/timeit command-line-interface14451980
Ref: 481314451980
Ref: library/timeit timeit-command-line-interface14451980
Ref: 480a14451980
Ref: library/timeit cmdoption-timeit-n14452249
Ref: 481414452249
Ref: library/timeit cmdoption-timeit-number14452249
Ref: 481514452249
Ref: library/timeit cmdoption-timeit-r14452327
Ref: 481614452327
Ref: library/timeit cmdoption-timeit-repeat14452327
Ref: 481714452327
Ref: library/timeit cmdoption-timeit-s14452410
Ref: 481814452410
Ref: library/timeit cmdoption-timeit-setup14452410
Ref: 481914452410
Ref: library/timeit cmdoption-timeit-p14452506
Ref: 481a14452506
Ref: library/timeit cmdoption-timeit-process14452506
Ref: 481b14452506
Ref: library/timeit cmdoption-timeit-u14452721
Ref: 481c14452721
Ref: library/timeit cmdoption-timeit-unit14452721
Ref: 481d14452721
Ref: library/timeit cmdoption-timeit-v14452884
Ref: 481e14452884
Ref: library/timeit cmdoption-timeit-verbose14452884
Ref: 481f14452884
Ref: library/timeit cmdoption-timeit-h14452976
Ref: 482014452976
Ref: library/timeit cmdoption-timeit-help14452976
Ref: 482114452976
Node: Examples<31>14454187
Ref: library/timeit examples14454326
Ref: 482214454326
Ref: library/timeit timeit-examples14454326
Ref: 480d14454326
Node: trace — Trace or track Python statement execution14457960
Ref: library/trace doc14458185
Ref: 482314458185
Ref: library/trace module-trace14458185
Ref: 10314458185
Ref: library/trace trace-trace-or-track-python-statement-execution14458185
Ref: 482414458185
Ref: library/trace translation-repo14458185
Ref: 482514458185
Ref: trace — Trace or track Python statement execution-Footnote-114458956
Ref: trace — Trace or track Python statement execution-Footnote-214459021
Node: Command-Line Usage<2>14459062
Ref: library/trace command-line-usage14459202
Ref: 482614459202
Ref: library/trace trace-cli14459202
Ref: 482714459202
Ref: library/trace cmdoption-trace-help14459556
Ref: 482814459556
Ref: library/trace cmdoption-trace-version14459606
Ref: 482914459606
Node: Main options14459824
Ref: library/trace main-options14459912
Ref: 482a14459912
Ref: library/trace cmdoption-trace-c14460290
Ref: 482d14460290
Ref: library/trace cmdoption-trace-count14460290
Ref: 482e14460290
Ref: library/trace cmdoption-trace-t14460543
Ref: 482c14460543
Ref: library/trace cmdoption-trace-trace14460543
Ref: 483214460543
Ref: library/trace cmdoption-trace-l14460610
Ref: 482b14460610
Ref: library/trace cmdoption-trace-listfuncs14460610
Ref: 483314460610
Ref: library/trace cmdoption-trace-r14460700
Ref: 483414460700
Ref: library/trace cmdoption-trace-report14460700
Ref: 483514460700
Ref: library/trace cmdoption-trace-T14460894
Ref: 483614460894
Ref: library/trace cmdoption-trace-trackcalls14460894
Ref: 483714460894
Node: Modifiers14460996
Ref: library/trace modifiers14461100
Ref: 483814461100
Ref: library/trace cmdoption-trace-f14461139
Ref: 483014461139
Ref: library/trace cmdoption-trace-file14461139
Ref: 483914461139
Ref: library/trace cmdoption-trace-C14461296
Ref: 482f14461296
Ref: library/trace cmdoption-trace-coverdir14461296
Ref: 483a14461296
Ref: library/trace cmdoption-trace-m14461486
Ref: 483b14461486
Ref: library/trace cmdoption-trace-missing14461486
Ref: 483c14461486
Ref: library/trace cmdoption-trace-s14461614
Ref: 483d14461614
Ref: library/trace cmdoption-trace-summary14461614
Ref: 483e14461614
Ref: library/trace cmdoption-trace-R14461764
Ref: 483114461764
Ref: library/trace cmdoption-trace-no-report14461764
Ref: 483f14461764
Ref: library/trace cmdoption-trace-g14461985
Ref: 484014461985
Ref: library/trace cmdoption-trace-timing14461985
Ref: 484114461985
Node: Filters14462106
Ref: library/trace filters14462189
Ref: 484214462189
Ref: library/trace cmdoption-trace-ignore-module14462271
Ref: 484314462271
Ref: library/trace cmdoption-trace-ignore-dir14462460
Ref: 484414462460
Node: Programmatic Interface14462663
Ref: library/trace programmatic-interface14462803
Ref: 484514462803
Ref: library/trace trace-api14462803
Ref: 484614462803
Ref: library/trace trace Trace14462868
Ref: 484714462868
Ref: library/trace trace Trace run14463780
Ref: 484814463780
Ref: library/trace trace Trace runctx14464022
Ref: 484914464022
Ref: library/trace trace Trace runfunc14464336
Ref: c7414464336
Ref: library/trace trace Trace results14464529
Ref: 484a14464529
Ref: library/trace trace CoverageResults14464838
Ref: 484b14464838
Ref: library/trace trace CoverageResults update14465003
Ref: 484c14465003
Ref: library/trace trace CoverageResults write_results14465121
Ref: 484d14465121
Node: tracemalloc — Trace memory allocations14466484
Ref: library/tracemalloc doc14466644
Ref: 484e14466644
Ref: library/tracemalloc module-tracemalloc14466644
Ref: 10514466644
Ref: library/tracemalloc tracemalloc-trace-memory-allocations14466644
Ref: 484f14466644
Ref: library/tracemalloc translation-repo14466644
Ref: 485014466644
Ref: tracemalloc — Trace memory allocations-Footnote-114467986
Node: Examples<32>14468057
Ref: library/tracemalloc examples14468158
Ref: 485114468158
Node: Display the top 1014468307
Ref: library/tracemalloc display-the-top-1014468402
Ref: 485214468402
Node: Compute differences14469886
Ref: library/tracemalloc compute-differences14470025
Ref: 485414470025
Node: Get the traceback of a memory block14472215
Ref: library/tracemalloc get-the-traceback-of-a-memory-block14472346
Ref: 485714472346
Node: Pretty top14474978
Ref: library/tracemalloc pretty-top14475081
Ref: 485814475081
Node: Record the current and peak size of all traced memory blocks14477543
Ref: library/tracemalloc record-the-current-and-peak-size-of-all-traced-memory-blocks14477650
Ref: 485914477650
Node: API14479342
Ref: library/tracemalloc api14479443
Ref: 485b14479443
Node: Functions<10>14479615
Ref: library/tracemalloc functions14479689
Ref: 485c14479689
Ref: library/tracemalloc tracemalloc clear_traces14479728
Ref: 485d14479728
Ref: library/tracemalloc tracemalloc get_object_traceback14479863
Ref: 1f2114479863
Ref: library/tracemalloc tracemalloc get_traceback_limit14480270
Ref: 485e14480270
Ref: library/tracemalloc tracemalloc get_traced_memory14480594
Ref: 485a14480594
Ref: library/tracemalloc tracemalloc reset_peak14480800
Ref: b3714480800
Ref: library/tracemalloc tracemalloc get_tracemalloc_memory14481434
Ref: 486014481434
Ref: library/tracemalloc tracemalloc is_tracing14481632
Ref: 486114481632
Ref: library/tracemalloc tracemalloc start14481865
Ref: 211514481865
Ref: library/tracemalloc tracemalloc stop14483231
Ref: 189514483231
Ref: library/tracemalloc tracemalloc take_snapshot14483665
Ref: 485f14483665
Node: DomainFilter14484365
Ref: library/tracemalloc domainfilter14484454
Ref: 486514484454
Ref: library/tracemalloc tracemalloc DomainFilter14484499
Ref: eef14484499
Ref: library/tracemalloc tracemalloc DomainFilter inclusive14484666
Ref: 486614484666
Ref: library/tracemalloc tracemalloc DomainFilter domain14484966
Ref: 486714484966
Node: Filter14485071
Ref: library/tracemalloc filter14485152
Ref: 486814485152
Ref: library/tracemalloc tracemalloc Filter14485187
Ref: 486914485187
Ref: library/tracemalloc tracemalloc Filter domain14486066
Ref: 486a14486066
Ref: library/tracemalloc tracemalloc Filter inclusive14486337
Ref: 486b14486337
Ref: library/tracemalloc tracemalloc Filter lineno14486769
Ref: 486d14486769
Ref: library/tracemalloc tracemalloc Filter filename_pattern14486921
Ref: 486c14486921
Ref: library/tracemalloc tracemalloc Filter all_frames14487035
Ref: 486e14487035
Node: Frame14487442
Ref: library/tracemalloc frame14487519
Ref: 487014487519
Ref: library/tracemalloc tracemalloc Frame14487552
Ref: 487114487552
Ref: library/tracemalloc tracemalloc Frame filename14487701
Ref: 487214487701
Ref: library/tracemalloc tracemalloc Frame lineno14487764
Ref: 487314487764
Node: Snapshot14487828
Ref: library/tracemalloc snapshot14487908
Ref: 487414487908
Ref: library/tracemalloc tracemalloc Snapshot14487947
Ref: 486414487947
Ref: library/tracemalloc tracemalloc Snapshot compare_to14488126
Ref: 486314488126
Ref: library/tracemalloc tracemalloc Snapshot dump14488854
Ref: 485514488854
Ref: library/tracemalloc tracemalloc Snapshot filter_traces14488990
Ref: 487b14488990
Ref: library/tracemalloc tracemalloc Snapshot load14489672
Ref: 485614489672
Ref: library/tracemalloc tracemalloc Snapshot statistics14489798
Ref: 485314489798
Ref: library/tracemalloc tracemalloc Snapshot traceback_limit14490999
Ref: 486f14490999
Ref: library/tracemalloc tracemalloc Snapshot traces14491218
Ref: 487c14491218
Node: Statistic14491513
Ref: library/tracemalloc statistic14491601
Ref: 488114491601
Ref: library/tracemalloc tracemalloc Statistic14491642
Ref: 487d14491642
Ref: library/tracemalloc tracemalloc Statistic count14491867
Ref: 487914491867
Ref: library/tracemalloc tracemalloc Statistic size14491942
Ref: 487e14491942
Ref: library/tracemalloc tracemalloc Statistic traceback14492029
Ref: 487f14492029
Node: StatisticDiff14492161
Ref: library/tracemalloc statisticdiff14492246
Ref: 488214492246
Ref: library/tracemalloc tracemalloc StatisticDiff14492295
Ref: 487514492295
Ref: library/tracemalloc tracemalloc StatisticDiff count14492596
Ref: 488314492596
Ref: library/tracemalloc tracemalloc StatisticDiff count_diff14492770
Ref: 487814492770
Ref: library/tracemalloc tracemalloc StatisticDiff size14492992
Ref: 487714492992
Ref: library/tracemalloc tracemalloc StatisticDiff size_diff14493188
Ref: 487614493188
Ref: library/tracemalloc tracemalloc StatisticDiff traceback14493422
Ref: 487a14493422
Node: Trace14493556
Ref: library/tracemalloc trace14493641
Ref: 488414493641
Ref: library/tracemalloc tracemalloc Trace14493674
Ref: 488014493674
Ref: library/tracemalloc tracemalloc Trace domain14493918
Ref: 488514493918
Ref: library/tracemalloc tracemalloc Trace size14494196
Ref: 488614494196
Ref: library/tracemalloc tracemalloc Trace traceback14494280
Ref: 488714494280
Node: Traceback14494412
Ref: library/tracemalloc traceback14494475
Ref: 488814494475
Ref: library/tracemalloc tracemalloc Traceback14494516
Ref: d9114494516
Ref: library/tracemalloc tracemalloc Traceback total_nframe14495449
Ref: 486214495449
Ref: library/tracemalloc tracemalloc Traceback format14495763
Ref: d9214495763
Node: Software Packaging and Distribution14496831
Ref: library/distribution doc14496994
Ref: 488a14496994
Ref: library/distribution software-packaging-and-distribution14496994
Ref: 488b14496994
Ref: library/distribution translation-repo14496994
Ref: 488c14496994
Ref: Software Packaging and Distribution-Footnote-114497521
Node: ensurepip — Bootstrapping the pip installer14497546
Ref: library/ensurepip doc14497713
Ref: 488d14497713
Ref: library/ensurepip ensurepip-bootstrapping-the-pip-installer14497713
Ref: 488e14497713
Ref: library/ensurepip module-ensurepip14497713
Ref: 5914497713
Ref: ensurepip — Bootstrapping the pip installer-Footnote-114499599
Ref: ensurepip — Bootstrapping the pip installer-Footnote-214499665
Node: Command-line interface<9>14499707
Ref: library/ensurepip command-line-interface14499833
Ref: 488f14499833
Ref: library/ensurepip ensurepip-cli14499833
Ref: 489014499833
Ref: library/ensurepip cmdoption-ensurepip-root14500582
Ref: 489114500582
Ref: library/ensurepip cmdoption-ensurepip-user14500811
Ref: 489214500811
Ref: library/ensurepip cmdoption-ensurepip-altinstall14501264
Ref: 489314501264
Ref: library/ensurepip cmdoption-ensurepip-default-pip14501391
Ref: 489414501391
Node: Module API14501631
Ref: library/ensurepip module-api14501757
Ref: 489514501757
Ref: library/ensurepip ensurepip version14501864
Ref: 489614501864
Ref: library/ensurepip ensurepip bootstrap14502026
Ref: 474314502026
Node: venv — Creation of virtual environments14503809
Ref: library/venv doc14504033
Ref: 489714504033
Ref: library/venv module-venv14504033
Ref: 11714504033
Ref: library/venv translation-repo14504033
Ref: 489814504033
Ref: library/venv venv-creation-of-virtual-environments14504033
Ref: 489914504033
Ref: library/venv venv-def14504258
Ref: 3e814504258
Ref: library/venv venv-intro14504258
Ref: 489a14504258
Ref: venv — Creation of virtual environments-Footnote-114506441
Ref: venv — Creation of virtual environments-Footnote-214506503
Ref: venv — Creation of virtual environments-Footnote-314506541
Ref: venv — Creation of virtual environments-Footnote-414506583
Node: Creating virtual environments14506711
Ref: library/venv creating-virtual-environments14506841
Ref: 489d14506841
Ref: library/venv venv-cli14508599
Ref: 489e14508599
Ref: library/venv cmdoption-venv-arg-ENV_DIR14508599
Ref: 489f14508599
Ref: library/venv cmdoption-venv-system-site-packages14508706
Ref: 48a014508706
Ref: library/venv cmdoption-venv-symlinks14508828
Ref: 48a114508828
Ref: library/venv cmdoption-venv-copies14508955
Ref: 48a214508955
Ref: library/venv cmdoption-venv-clear14509081
Ref: 48a314509081
Ref: library/venv cmdoption-venv-upgrade14509213
Ref: 48a414509213
Ref: library/venv cmdoption-venv-without-pip14509356
Ref: 48a514509356
Ref: library/venv cmdoption-venv-prompt14509489
Ref: 48a614509489
Ref: library/venv cmdoption-venv-upgrade-deps14509586
Ref: 48a714509586
Ref: library/venv cmdoption-venv-without-scm-ignore-files14509683
Ref: 48a814509683
Ref: Creating virtual environments-Footnote-114511631
Node: How venvs work14511686
Ref: library/venv how-venvs-work14511831
Ref: 48a914511831
Ref: library/venv venv-explanation14511831
Ref: 67e14511831
Node: API<2>14516324
Ref: library/venv api14516474
Ref: 48aa14516474
Ref: library/venv venv-api14516474
Ref: 10f714516474
Ref: library/venv venv EnvBuilder14516731
Ref: 57114516731
Ref: library/venv venv EnvBuilder create14519039
Ref: 48ac14519039
Ref: library/venv venv EnvBuilder ensure_directories14520334
Ref: 48ad14520334
Ref: library/venv venv EnvBuilder create_configuration14523070
Ref: 48ae14523070
Ref: library/venv venv EnvBuilder setup_python14523208
Ref: 48af14523208
Ref: library/venv venv EnvBuilder setup_scripts14523574
Ref: 48b014523574
Ref: library/venv venv EnvBuilder upgrade_dependencies14523723
Ref: 48b314523723
Ref: library/venv venv EnvBuilder post_setup14524098
Ref: 48b114524098
Ref: library/venv venv EnvBuilder install_scripts14524333
Ref: 48b214524333
Ref: library/venv venv EnvBuilder create_git_ignore_file14525772
Ref: 48ab14525772
Ref: library/venv venv create14526606
Ref: 57214526606
Ref: API<2>-Footnote-114527300
Ref: API<2>-Footnote-214527338
Node: An example of extending EnvBuilder14527383
Ref: library/venv an-example-of-extending-envbuilder14527510
Ref: 48b414527510
Ref: An example of extending EnvBuilder-Footnote-114537655
Node: zipapp — Manage executable Python zip archives14537702
Ref: library/zipapp doc14537872
Ref: 48b514537872
Ref: library/zipapp module-zipapp14537872
Ref: 13614537872
Ref: library/zipapp translation-repo14537872
Ref: 48b614537872
Ref: library/zipapp zipapp-manage-executable-python-zip-archives14537872
Ref: 48b714537872
Ref: zipapp — Manage executable Python zip archives-Footnote-114538651
Node: Basic Example14538717
Ref: library/zipapp basic-example14538849
Ref: 48ba14538849
Node: Command-Line Interface<4>14539254
Ref: library/zipapp command-line-interface14539405
Ref: 48bb14539405
Ref: library/zipapp zipapp-command-line-interface14539405
Ref: 48b814539405
Ref: library/zipapp cmdoption-zipapp-o14539901
Ref: 48bc14539901
Ref: library/zipapp cmdoption-zipapp-output14539901
Ref: 48bd14539901
Ref: library/zipapp cmdoption-zipapp-p14540398
Ref: 48be14540398
Ref: library/zipapp cmdoption-zipapp-python14540398
Ref: 48bf14540398
Ref: library/zipapp cmdoption-zipapp-m14540674
Ref: 48c014540674
Ref: library/zipapp cmdoption-zipapp-main14540674
Ref: 48c114540674
Ref: library/zipapp cmdoption-zipapp-c14541097
Ref: 48c214541097
Ref: library/zipapp cmdoption-zipapp-compress14541097
Ref: 48c314541097
Ref: library/zipapp cmdoption-zipapp-info14541374
Ref: 48c414541374
Ref: library/zipapp cmdoption-zipapp-h14541577
Ref: 48c514541577
Ref: library/zipapp cmdoption-zipapp-help14541577
Ref: 48c614541577
Node: Python API14541645
Ref: library/zipapp python-api14541795
Ref: 48c714541795
Ref: library/zipapp zipapp-python-api14541795
Ref: 48b914541795
Ref: library/zipapp zipapp create_archive14541883
Ref: dab14541883
Ref: library/zipapp zipapp get_interpreter14545675
Ref: 48c814545675
Node: Examples<33>14546032
Ref: library/zipapp examples14546183
Ref: 48c914546183
Ref: library/zipapp zipapp-examples14546183
Ref: 48ca14546183
Node: Specifying the Interpreter14547555
Ref: library/zipapp specifying-the-interpreter14547740
Ref: 48cb14547740
Ref: library/zipapp zipapp-specifying-the-interpreter14547740
Ref: 48cc14547740
Node: Creating Standalone Applications with zipapp14548963
Ref: library/zipapp creating-standalone-applications-with-zipapp14549177
Ref: 48cd14549177
Node: Caveats14550886
Ref: library/zipapp caveats14550974
Ref: 48ce14550974
Node: The Python Zip Application Archive Format14551713
Ref: library/zipapp the-python-zip-application-archive-format14551892
Ref: 48cf14551892
Node: Python Runtime Services14553789
Ref: library/python doc14553955
Ref: 48d014553955
Ref: library/python python14553955
Ref: 48d114553955
Ref: library/python python-runtime-services14553955
Ref: 48d214553955
Ref: library/python translation-repo14553955
Ref: 48d314553955
Node: sys — System-specific parameters and functions14554971
Ref: library/sys doc14555133
Ref: 48d414555133
Ref: library/sys module-sys14555133
Ref: df14555133
Ref: library/sys sys-system-specific-parameters-and-functions14555133
Ref: 48d514555133
Ref: library/sys sys abiflags14555557
Ref: c5b14555557
Ref: library/sys sys addaudithook14555926
Ref: 473814555926
Ref: library/sys sys argv14558164
Ref: 146c14558164
Ref: library/sys auditing14559090
Ref: 1c5614559090
Ref: library/sys sys audit14559090
Ref: 190314559090
Ref: library/sys sys base_exec_prefix14560490
Ref: 3ea14560490
Ref: library/sys sys base_prefix14560977
Ref: 3e614560977
Ref: library/sys sys byteorder14561442
Ref: 25d614561442
Ref: library/sys sys builtin_module_names14561698
Ref: 203114561698
Ref: library/sys sys call_tracing14562031
Ref: 1bab14562031
Ref: library/sys sys copyright14562553
Ref: 48d614562553
Ref: library/sys sys _clear_type_cache14562661
Ref: 29214562661
Ref: library/sys sys _clear_internal_caches14563105
Ref: 36414563105
Ref: library/sys sys _current_frames14563344
Ref: 163a14563344
Ref: library/sys sys _current_exceptions14564214
Ref: 6ea14564214
Ref: library/sys sys breakpointhook14564930
Ref: cd314564930
Ref: library/sys sys _debugmallocstats14566830
Ref: 48d714566830
Ref: library/sys sys dllhandle14567327
Ref: 48d814567327
Ref: library/sys sys displayhook14567449
Ref: 172614567449
Ref: library/sys sys dont_write_bytecode14568981
Ref: 48d914568981
Ref: library/sys sys _emscripten_info14569380
Ref: 1b7614569380
Ref: library/sys sys _emscripten_info emscripten_version14569595
Ref: 48da14569595
Ref: library/sys sys _emscripten_info runtime14569755
Ref: 48db14569755
Ref: library/sys sys _emscripten_info pthreads14569910
Ref: 48dc14569910
Ref: library/sys sys _emscripten_info shared_memory14570035
Ref: 48dd14570035
Ref: library/sys sys pycache_prefix14570233
Ref: b9e14570233
Ref: library/sys sys excepthook14571206
Ref: a0e14571206
Ref: library/sys sys __breakpointhook__14572575
Ref: 48de14572575
Ref: library/sys sys __displayhook__14572608
Ref: 48df14572608
Ref: library/sys sys __excepthook__14572638
Ref: 48e014572638
Ref: library/sys sys __unraisablehook__14572667
Ref: 48e114572667
Ref: library/sys sys exception14573179
Ref: 89c14573179
Ref: library/sys sys exc_info14573649
Ref: 89b14573649
Ref: library/sys sys exec_prefix14574660
Ref: 3eb14574660
Ref: library/sys sys executable14576081
Ref: 3ed14576081
Ref: library/sys sys exit14576382
Ref: 27714576382
Ref: library/sys sys flags14578053
Ref: 89d14578053
Ref: library/sys sys flags debug14578292
Ref: 48e214578292
Ref: library/sys sys flags inspect14578492
Ref: 177814578492
Ref: library/sys sys flags interactive14578694
Ref: 48e314578694
Ref: library/sys sys flags isolated14578889
Ref: 48e414578889
Ref: library/sys sys flags optimize14579086
Ref: 48e514579086
Ref: library/sys sys flags dont_write_bytecode14579313
Ref: 48e614579313
Ref: library/sys sys flags no_user_site14579504
Ref: 48e714579504
Ref: library/sys sys flags no_site14579697
Ref: 48e814579697
Ref: library/sys sys flags ignore_environment14579906
Ref: 48e914579906
Ref: library/sys sys flags verbose14580092
Ref: 48ea14580092
Ref: library/sys sys flags bytes_warning14580296
Ref: 48eb14580296
Ref: library/sys sys flags quiet14580485
Ref: 48ec14580485
Ref: library/sys sys flags hash_randomization14580696
Ref: 48ed14580696
Ref: library/sys sys flags dev_mode14580884
Ref: 1e6a14580884
Ref: library/sys sys flags utf8_mode14581184
Ref: 48ee14581184
Ref: library/sys sys flags safe_path14581386
Ref: 53f14581386
Ref: library/sys sys flags int_max_str_digits14581592
Ref: 26be14581592
Ref: library/sys sys flags warn_default_encoding14581929
Ref: 48ef14581929
Ref: library/sys sys flags gil14582130
Ref: 48f014582130
Ref: library/sys sys flags thread_inherit_context14582377
Ref: 17514582377
Ref: library/sys sys flags context_aware_warnings14582704
Ref: 18a14582704
Ref: library/sys sys float_info14584081
Ref: 1db714584081
Ref: library/sys sys float_info epsilon14585039
Ref: 48f214585039
Ref: library/sys sys float_info dig14585735
Ref: 48f314585735
Ref: library/sys sys float_info mant_dig14586246
Ref: 48f414586246
Ref: library/sys sys float_info max14586738
Ref: 48f514586738
Ref: library/sys sys float_info max_exp14587121
Ref: 48f614587121
Ref: library/sys sys float_info max_10_exp14587599
Ref: 48f714587599
Ref: library/sys sys float_info min14588119
Ref: 48f814588119
Ref: library/sys sys float_info min_exp14588928
Ref: 48f914588928
Ref: library/sys sys float_info min_10_exp14589396
Ref: 48fa14589396
Ref: library/sys sys float_info radix14589812
Ref: 48fb14589812
Ref: library/sys sys float_info rounds14590181
Ref: 48fc14590181
Ref: library/sys sys float_repr_style14593075
Ref: 150214593075
Ref: library/sys sys getallocatedblocks14593616
Ref: 11c914593616
Ref: library/sys sys getunicodeinternedsize14594260
Ref: 48fd14594260
Ref: library/sys sys getandroidapilevel14594402
Ref: d8514594402
Ref: library/sys sys getdefaultencoding14594747
Ref: 48fe14594747
Ref: library/sys sys getdlopenflags14594917
Ref: 171514594917
Ref: library/sys sys getfilesystemencoding14595230
Ref: e5514595230
Ref: library/sys sys getfilesystemencodeerrors14596657
Ref: ee414596657
Ref: library/sys sys get_int_max_str_digits14597399
Ref: 180014597399
Ref: library/sys sys getrefcount14597627
Ref: 2ce14597627
Ref: library/sys sys getrecursionlimit14598578
Ref: 6ec14598578
Ref: library/sys sys getsizeof14598890
Ref: 1ac314598890
Ref: library/sys sys getswitchinterval14599842
Ref: b4514599842
Ref: library/sys sys _getframe14600023
Ref: 8f114600023
Ref: library/sys sys _getframemodulename14600693
Ref: 1ac714600693
Ref: library/sys sys getobjects14601439
Ref: 28e14601439
Ref: library/sys sys getprofile14602581
Ref: 15e714602581
Ref: library/sys sys gettrace14602682
Ref: 15e814602682
Ref: library/sys sys getwindowsversion14603135
Ref: ee514603135
Ref: library/sys sys get_asyncgen_hooks14605674
Ref: 1bac14605674
Ref: library/sys sys get_coroutine_origin_tracking_depth14606283
Ref: d8614606283
Ref: library/sys sys hash_info14606635
Ref: 120114606635
Ref: library/sys sys hash_info width14606849
Ref: 490114606849
Ref: library/sys sys hash_info modulus14606936
Ref: 25de14606936
Ref: library/sys sys hash_info inf14607035
Ref: 490214607035
Ref: library/sys sys hash_info nan14607129
Ref: 490314607129
Ref: library/sys sys hash_info imag14607210
Ref: 490414607210
Ref: library/sys sys hash_info algorithm14607320
Ref: 490514607320
Ref: library/sys sys hash_info hash_bits14607450
Ref: 490614607450
Ref: library/sys sys hash_info seed_bits14607549
Ref: 490714607549
Ref: library/sys sys hash_info cutoff14607648
Ref: 490814607648
Ref: library/sys sys hexversion14607907
Ref: 490914607907
Ref: library/sys sys implementation14608801
Ref: 73c14608801
Ref: library/sys sys int_info14611472
Ref: 149b14611472
Ref: library/sys sys int_info bits_per_digit14611641
Ref: 490b14611641
Ref: library/sys sys int_info sizeof_digit14611827
Ref: 490c14611827
Ref: library/sys sys int_info default_max_str_digits14611940
Ref: 26bf14611940
Ref: library/sys sys int_info str_digits_check_threshold14612126
Ref: 490d14612126
Ref: library/sys sys __interactivehook__14612524
Ref: 11ca14612524
Ref: library/sys sys intern14613073
Ref: 14e314613073
Ref: library/sys sys _is_gil_enabled14613857
Ref: 490e14613857
Ref: library/sys sys is_finalizing14614156
Ref: c8214614156
Ref: library/sys sys _jit14614418
Ref: 29314614418
Ref: library/sys sys _jit is_available14614794
Ref: 44f14614794
Ref: library/sys sys _jit is_enabled14615163
Ref: 45014615163
Ref: library/sys sys _jit is_active14615599
Ref: 184914615599
Ref: library/sys sys last_exc14616924
Ref: 6e614616924
Ref: library/sys sys _is_immortal14617497
Ref: 28f14617497
Ref: library/sys sys _is_interned14618085
Ref: 55914618085
Ref: library/sys sys last_type14618378
Ref: 6e714618378
Ref: library/sys sys last_value14618402
Ref: 6e814618402
Ref: library/sys sys last_traceback14618427
Ref: 6e914618427
Ref: library/sys sys maxsize14618656
Ref: 13cd14618656
Ref: library/sys sys maxunicode14618878
Ref: 124f14618878
Ref: library/sys sys meta_path14619282
Ref: f2914619282
Ref: library/sys sys modules14620605
Ref: 17ce14620605
Ref: library/sys sys orig_argv14621213
Ref: a4314621213
Ref: library/sys sys path14621689
Ref: 3e414621689
Ref: library/sys sys path_hooks14622967
Ref: 122614622967
Ref: library/sys sys path_importer_cache14623258
Ref: 7fb14623258
Ref: library/sys sys platform14623665
Ref: 29114623665
Ref: library/sys sys platlibdir14626303
Ref: b3414626303
Ref: library/sys sys prefix14627307
Ref: 3e714627307
Ref: library/sys sys ps114628433
Ref: 211e14628433
Ref: library/sys sys ps214628451
Ref: 211f14628451
Ref: library/sys sys setdlopenflags14628927
Ref: 132714628927
Ref: library/sys sys set_int_max_str_digits14629528
Ref: 18d914629528
Ref: library/sys sys setprofile14629765
Ref: 170514629765
Ref: library/sys sys setrecursionlimit14632168
Ref: 6eb14632168
Ref: library/sys sys setswitchinterval14632965
Ref: b4614632965
Ref: library/sys sys settrace14633542
Ref: 2e114633542
Ref: library/sys sys set_asyncgen_hooks14638339
Ref: 198514638339
Ref: library/sys sys set_coroutine_origin_tracking_depth14639450
Ref: d8714639450
Ref: library/sys sys activate_stack_trampoline14640268
Ref: 69b14640268
Ref: library/sys sys deactivate_stack_trampoline14640712
Ref: 69c14640712
Ref: library/sys sys is_stack_trampoline_active14640965
Ref: 69d14640965
Ref: library/sys sys remote_exec14641149
Ref: 16d14641149
Ref: library/sys sys _enablelegacywindowsfsencoding14642825
Ref: 33e14642825
Ref: library/sys sys stdin14643794
Ref: 76014643794
Ref: library/sys sys stdout14643814
Ref: ccf14643814
Ref: library/sys sys stderr14643835
Ref: b3514643835
Ref: library/sys sys __stdin__14647000
Ref: 491114647000
Ref: library/sys sys __stdout__14647024
Ref: 2ce114647024
Ref: library/sys sys __stderr__14647049
Ref: 46bb14647049
Ref: library/sys sys stdlib_module_names14648014
Ref: a4414648014
Ref: library/sys sys thread_info14648749
Ref: 135814648749
Ref: library/sys sys thread_info name14648866
Ref: 491214648866
Ref: library/sys sys thread_info lock14649220
Ref: 491314649220
Ref: library/sys sys thread_info version14649519
Ref: 491414649519
Ref: library/sys sys tracebacklimit14649716
Ref: 192c14649716
Ref: library/sys sys unraisablehook14650080
Ref: 50814650080
Ref: library/sys sys version14651925
Ref: 49d14651925
Ref: library/sys sys api_version14652327
Ref: 491514652327
Ref: library/sys sys version_info14652621
Ref: 8b014652621
Ref: library/sys sys warnoptions14653247
Ref: 3f514653247
Ref: library/sys sys winver14653466
Ref: 491714653466
Ref: library/sys sys _xoptions14654107
Ref: 211a14654107
Ref: library/sys c9914654927
Ref: 48f114654927
Ref: sys — System-specific parameters and functions-Footnote-114655137
Ref: sys — System-specific parameters and functions-Footnote-214655179
Ref: sys — System-specific parameters and functions-Footnote-314655221
Ref: sys — System-specific parameters and functions-Footnote-414655263
Ref: sys — System-specific parameters and functions-Footnote-514655368
Ref: sys — System-specific parameters and functions-Footnote-614655410
Ref: sys — System-specific parameters and functions-Footnote-714655452
Ref: sys — System-specific parameters and functions-Footnote-814655494
Ref: sys — System-specific parameters and functions-Footnote-914655536
Ref: sys — System-specific parameters and functions-Footnote-1014655578
Ref: sys — System-specific parameters and functions-Footnote-1114655621
Ref: sys — System-specific parameters and functions-Footnote-1214655664
Ref: sys — System-specific parameters and functions-Footnote-1314655707
Ref: sys — System-specific parameters and functions-Footnote-1414655750
Ref: sys — System-specific parameters and functions-Footnote-1514655793
Ref: sys — System-specific parameters and functions-Footnote-1614655836
Ref: sys — System-specific parameters and functions-Footnote-1714655879
Ref: sys — System-specific parameters and functions-Footnote-1814655960
Ref: sys — System-specific parameters and functions-Footnote-1914656003
Ref: sys — System-specific parameters and functions-Footnote-2014656046
Ref: sys — System-specific parameters and functions-Footnote-2114656089
Node: sys monitoring — Execution event monitoring14656132
Ref: library/sys monitoring doc14656371
Ref: 491814656371
Ref: library/sys monitoring module-sys monitoring14656371
Ref: e014656371
Ref: library/sys monitoring sys-monitoring-execution-event-monitoring14656371
Ref: 491914656371
Ref: library/sys monitoring translation-repo14656371
Ref: 491a14656371
Node: Tool identifiers14657381
Ref: library/sys monitoring tool-identifiers14657494
Ref: 491b14657494
Node: Registering and using tools14658051
Ref: library/sys monitoring registering-and-using-tools14658131
Ref: 491e14658131
Ref: library/sys monitoring sys monitoring use_tool_id14658206
Ref: 491f14658206
Ref: library/sys monitoring sys monitoring clear_tool_id14658463
Ref: 191614658463
Ref: library/sys monitoring sys monitoring free_tool_id14658616
Ref: 492014658616
Ref: library/sys monitoring sys monitoring get_tool14658823
Ref: 492114658823
Node: Events14659326
Ref: library/sys monitoring events14659473
Ref: 491c14659473
Ref: library/sys monitoring monitoring-event-BRANCH_LEFT14659543
Ref: 29514659543
Ref: library/sys monitoring monitoring-event-BRANCH_RIGHT14659880
Ref: 29614659880
Ref: library/sys monitoring monitoring-event-CALL14659977
Ref: 19a514659977
Ref: library/sys monitoring monitoring-event-C_RAISE14660087
Ref: 492214660087
Ref: library/sys monitoring monitoring-event-C_RETURN14660249
Ref: 492314660249
Ref: library/sys monitoring monitoring-event-EXCEPTION_HANDLED14660401
Ref: 492414660401
Ref: library/sys monitoring monitoring-event-INSTRUCTION14660495
Ref: 492514660495
Ref: library/sys monitoring monitoring-event-JUMP14660600
Ref: 492614660600
Ref: library/sys monitoring monitoring-event-LINE14660713
Ref: 492714660713
Ref: library/sys monitoring monitoring-event-PY_RESUME14660878
Ref: 492814660878
Ref: library/sys monitoring monitoring-event-PY_RETURN14661049
Ref: 492914661049
Ref: library/sys monitoring monitoring-event-PY_START14661228
Ref: 492a14661228
Ref: library/sys monitoring monitoring-event-PY_THROW14661399
Ref: 183d14661399
Ref: library/sys monitoring monitoring-event-PY_UNWIND14661513
Ref: 492b14661513
Ref: library/sys monitoring monitoring-event-PY_YIELD14661749
Ref: 492c14661749
Ref: library/sys monitoring monitoring-event-RAISE14661925
Ref: 195c14661925
Ref: library/sys monitoring monitoring-event-RERAISE14662072
Ref: 492e14662072
Ref: library/sys monitoring monitoring-event-STOP_ITERATION14662218
Ref: 492d14662218
Ref: library/sys monitoring monitoring-event-NO_EVENTS14662770
Ref: 493014662770
Node: Local events14663129
Ref: library/sys monitoring local-events14663209
Ref: 493114663209
Ref: library/sys monitoring monitoring-event-local14663209
Ref: 493214663209
Node: Deprecated event14663730
Ref: library/sys monitoring deprecated-event14663835
Ref: 493314663835
Node: Ancillary events14664094
Ref: library/sys monitoring ancillary-events14664199
Ref: 493414664199
Node: Other events14664642
Ref: library/sys monitoring monitoring-event-global14664755
Ref: 493514664755
Ref: library/sys monitoring other-events14664755
Ref: 493614664755
Node: The STOP_ITERATION event14665102
Ref: library/sys monitoring the-stop-iteration-event14665190
Ref: 492f14665190
Ref: The STOP_ITERATION event-Footnote-114666189
Node: Turning events on and off14666270
Ref: library/sys monitoring turning-events-on-and-off14666431
Ref: 493814666431
Node: Setting events globally14666881
Ref: library/sys monitoring setting-events-globally14666997
Ref: 493914666997
Ref: library/sys monitoring sys monitoring get_events14667149
Ref: 493a14667149
Ref: library/sys monitoring sys monitoring set_events14667279
Ref: 493b14667279
Node: Per code object events14667529
Ref: library/sys monitoring per-code-object-events14667670
Ref: 493c14667670
Ref: library/sys monitoring sys monitoring get_local_events14667999
Ref: 493d14667999
Ref: library/sys monitoring sys monitoring set_local_events14668156
Ref: 493e14668156
Node: Disabling events14668433
Ref: library/sys monitoring disabling-events14668542
Ref: 493f14668542
Ref: library/sys monitoring sys monitoring DISABLE14668597
Ref: 493714668597
Ref: library/sys monitoring sys monitoring restart_events14669432
Ref: 494014669432
Node: Registering callback functions14669594
Ref: library/sys monitoring callbacks14669740
Ref: 491d14669740
Ref: library/sys monitoring registering-callback-functions14669740
Ref: 494114669740
Ref: library/sys monitoring sys monitoring register_callback14669823
Ref: 474814669823
Node: Callback function arguments14670795
Ref: library/sys monitoring callback-function-arguments14670889
Ref: 494214670889
Ref: library/sys monitoring sys monitoring MISSING14670966
Ref: 494314670966
Node: sysconfig — Provide access to Python’s configuration information14672997
Ref: library/sysconfig doc14673217
Ref: 494414673217
Ref: library/sysconfig module-sysconfig14673217
Ref: e114673217
Ref: library/sysconfig sysconfig-provide-access-to-python-s-configuration-information14673217
Ref: 494514673217
Ref: library/sysconfig translation-repo14673217
Ref: 494614673217
Ref: sysconfig — Provide access to Python’s configuration information-Footnote-114673953
Node: Configuration variables14674019
Ref: library/sysconfig configuration-variables14674174
Ref: 494714674174
Ref: library/sysconfig sysconfig get_config_vars14674664
Ref: 29814674664
Ref: library/sysconfig sysconfig get_config_var14675035
Ref: 17414675035
Node: Installation paths14675478
Ref: library/sysconfig id114675653
Ref: 494814675653
Ref: library/sysconfig installation-paths14675653
Ref: 44914675653
Node: User scheme14677995
Ref: library/sysconfig sysconfig-user-scheme14678158
Ref: 212014678158
Ref: library/sysconfig user-scheme14678158
Ref: 494914678158
Node: posix_user14678687
Ref: library/sysconfig posix-user14678761
Ref: 494a14678761
Node: nt_user14679605
Ref: library/sysconfig nt-user14679706
Ref: 494b14679706
Node: osx_framework_user14680538
Ref: library/sysconfig osx-framework-user14680620
Ref: 494c14680620
Node: Home scheme14681460
Ref: library/sysconfig home-scheme14681618
Ref: 494d14681618
Ref: library/sysconfig sysconfig-home-scheme14681618
Ref: 494e14681618
Node: posix_home14682095
Ref: library/sysconfig posix-home14682153
Ref: 494f14682153
Node: Prefix scheme14683003
Ref: library/sysconfig prefix-scheme14683177
Ref: 495014683177
Ref: library/sysconfig sysconfig-prefix-scheme14683177
Ref: 495114683177
Node: posix_prefix14684513
Ref: library/sysconfig posix-prefix14684586
Ref: 495214684586
Node: nt14685515
Ref: library/sysconfig nt14685588
Ref: 495314685588
Node: Installation path functions14686429
Ref: library/sysconfig installation-path-functions14686610
Ref: 495414686610
Ref: library/sysconfig sysconfig get_scheme_names14686772
Ref: 495514686772
Ref: library/sysconfig sysconfig get_default_scheme14686910
Ref: 1b9d14686910
Ref: library/sysconfig sysconfig get_preferred_scheme14687275
Ref: 8a014687275
Ref: library/sysconfig sysconfig _get_preferred_schemes14687871
Ref: 495614687871
Ref: library/sysconfig sysconfig get_path_names14688538
Ref: 495714688538
Ref: library/sysconfig sysconfig get_path14688677
Ref: 153514688677
Ref: library/sysconfig sysconfig get_paths14689904
Ref: 34014689904
Node: Other functions<3>14690528
Ref: library/sysconfig other-functions14690717
Ref: 495814690717
Ref: library/sysconfig sysconfig get_python_version14690770
Ref: 144b14690770
Ref: library/sysconfig sysconfig get_platform14690941
Ref: 144a14690941
Ref: library/sysconfig sysconfig is_python_build14691955
Ref: 32d14691955
Ref: library/sysconfig sysconfig parse_config_h14692246
Ref: 495914692246
Ref: library/sysconfig sysconfig get_config_h_filename14692640
Ref: 495a14692640
Ref: library/sysconfig sysconfig get_makefile_filename14692733
Ref: 495b14692733
Ref: library/sysconfig sysconfig-cli14692823
Ref: 495c14692823
Node: Command-line usage<6>14692824
Ref: library/sysconfig command-line-usage14692977
Ref: 495d14692977
Ref: library/sysconfig using-sysconfig-as-a-script14692977
Ref: 495e14692977
Node: builtins — Built-in objects14694029
Ref: library/builtins doc14694243
Ref: 495f14694243
Ref: library/builtins builtins-built-in-objects14694243
Ref: 496014694243
Ref: library/builtins module-builtins14694243
Ref: 1314694243
Ref: library/builtins translation-repo14694243
Ref: 496114694243
Node: __main__ — Top-level code environment14695828
Ref: library/__main__ doc14696002
Ref: 496214696002
Ref: library/__main__ main-top-level-code-environment14696002
Ref: 496314696002
Ref: library/__main__ module-__main__14696002
Ref: 114696002
Ref: library/__main__ translation-repo14696002
Ref: 496414696002
Node: __name__ == '__main__'14696834
Ref: library/__main__ name-equals-main14696971
Ref: 496514696971
Ref: library/__main__ name-main14696971
Ref: 496614696971
Node: What is the «top-level code environment»?14697745
Ref: library/__main__ what-is-the-top-level-code-environment14697871
Ref: 496714697871
Node: Idiomatic Usage14699885
Ref: library/__main__ idiomatic-usage14700044
Ref: 496814700044
Node: Packaging Considerations14702024
Ref: library/__main__ packaging-considerations14702131
Ref: 496914702131
Ref: Packaging Considerations-Footnote-114703642
Ref: Packaging Considerations-Footnote-214703671
Node: __main__ py in Python Packages14703709
Ref: library/__main__ main-py-in-python-packages14703870
Ref: 496a14703870
Node: Idiomatic Usage<2>14705278
Ref: library/__main__ id114705363
Ref: 496b14705363
Node: import __main__14706708
Ref: library/__main__ import-main14706838
Ref: 496c14706838
Node: warnings — Warning control14709738
Ref: library/warnings doc14709911
Ref: 496d14709911
Ref: library/warnings module-warnings14709911
Ref: 11814709911
Ref: library/warnings translation-repo14709911
Ref: 496e14709911
Ref: library/warnings warnings-warning-control14709911
Ref: 496f14709911
Ref: warnings — Warning control-Footnote-114712271
Node: Warning Categories14712339
Ref: library/warnings id114712450
Ref: 497314712450
Ref: library/warnings warning-categories14712450
Ref: 26f414712450
Node: The Warnings Filter14716642
Ref: library/warnings the-warnings-filter14716794
Ref: 497414716794
Ref: library/warnings warning-filter14716794
Ref: 1b114716794
Node: Repeated Warning Suppression Criteria14720078
Ref: library/warnings id214720206
Ref: 497514720206
Ref: library/warnings repeated-warning-suppression-criteria14720206
Ref: 497614720206
Node: Describing Warning Filters14720841
Ref: library/warnings describing-warning-filters14721000
Ref: 211314721000
Ref: library/warnings id314721000
Ref: 497714721000
Node: Default Warning Filter14722725
Ref: library/warnings default-warning-filter14722876
Ref: 497814722876
Ref: library/warnings id414722876
Ref: 497914722876
Node: Overriding the default filter14723991
Ref: library/warnings overriding-the-default-filter14724107
Ref: 497a14724107
Ref: library/warnings warning-disable14724107
Ref: 497b14724107
Node: Temporarily Suppressing Warnings14725542
Ref: library/warnings temporarily-suppressing-warnings14725692
Ref: 497c14725692
Ref: library/warnings warning-suppress14725692
Ref: 497d14725692
Node: Testing Warnings14726774
Ref: library/warnings testing-warnings14726951
Ref: 497f14726951
Ref: library/warnings warning-testing14726951
Ref: 498014726951
Node: Updating Code For New Versions of Dependencies14728984
Ref: library/warnings updating-code-for-new-versions-of-dependencies14729148
Ref: 498114729148
Ref: library/warnings warning-ignored14729148
Ref: 460714729148
Node: Available Functions14730536
Ref: library/warnings available-functions14730710
Ref: 498214730710
Ref: library/warnings warning-functions14730710
Ref: 498314730710
Ref: library/warnings warnings warn14730771
Ref: 172014730771
Ref: library/warnings warnings warn_explicit14733357
Ref: eff14733357
Ref: library/warnings warnings showwarning14734744
Ref: 497214734744
Ref: library/warnings warnings formatwarning14735382
Ref: 1de014735382
Ref: library/warnings warnings filterwarnings14735814
Ref: 16b014735814
Ref: library/warnings warnings simplefilter14736490
Ref: 8d114736490
Ref: library/warnings warnings resetwarnings14736926
Ref: 497114736926
Ref: library/warnings warnings deprecated14737194
Ref: 48a14737194
Ref: Available Functions-Footnote-114739063
Node: Available Context Managers14739105
Ref: library/warnings available-context-managers14739270
Ref: 498414739270
Ref: library/warnings warnings catch_warnings14739345
Ref: 17914739345
Node: Concurrent safety of Context Managers14740984
Ref: library/warnings concurrent-safety-of-context-managers14741121
Ref: 498514741121
Ref: library/warnings warning-concurrent-safe14741121
Ref: 497e14741121
Node: dataclasses — Data Classes14744201
Ref: library/dataclasses doc14744387
Ref: 498614744387
Ref: library/dataclasses dataclasses-data-classes14744387
Ref: 498714744387
Ref: library/dataclasses module-dataclasses14744387
Ref: 3314744387
Ref: library/dataclasses translation-repo14744387
Ref: 498814744387
Ref: dataclasses — Data Classes-Footnote-114746079
Ref: dataclasses — Data Classes-Footnote-214746150
Ref: dataclasses — Data Classes-Footnote-314746192
Node: Module contents<4>14746234
Ref: library/dataclasses module-contents14746346
Ref: 498914746346
Ref: library/dataclasses dataclasses dataclass14746397
Ref: 4e214746397
Ref: library/dataclasses dataclasses field14756012
Ref: 194214756012
Ref: library/dataclasses dataclasses Field14760739
Ref: 194314760739
Ref: library/dataclasses dataclasses InitVar14761496
Ref: 1b9c14761496
Ref: library/dataclasses dataclasses fields14761904
Ref: 191d14761904
Ref: library/dataclasses dataclasses asdict14762283
Ref: 1a7d14762283
Ref: library/dataclasses dataclasses astuple14763325
Ref: 1a8614763325
Ref: library/dataclasses dataclasses make_dataclass14764064
Ref: 184414764064
Ref: library/dataclasses dataclasses replace14766229
Ref: 1a5214766229
Ref: library/dataclasses dataclasses is_dataclass14767729
Ref: 1bff14767729
Ref: library/dataclasses dataclasses MISSING14768208
Ref: 498c14768208
Ref: library/dataclasses dataclasses KW_ONLY14768311
Ref: 498b14768311
Ref: library/dataclasses dataclasses FrozenInstanceError14769254
Ref: 498f14769254
Ref: Module contents<4>-Footnote-114769565
Node: Post-init processing14769620
Ref: library/dataclasses id114769756
Ref: 499014769756
Ref: library/dataclasses post-init-processing14769756
Ref: 499114769756
Ref: library/dataclasses dataclasses __post_init__14769817
Ref: 498e14769817
Node: Class variables14771578
Ref: library/dataclasses class-variables14771715
Ref: 499214771715
Ref: library/dataclasses dataclasses-class-variables14771715
Ref: 499314771715
Ref: Class variables-Footnote-114772273
Node: Init-only variables14772315
Ref: library/dataclasses dataclasses-init-only-variables14772448
Ref: 498d14772448
Ref: library/dataclasses init-only-variables14772448
Ref: 499414772448
Node: Frozen instances14773677
Ref: library/dataclasses dataclasses-frozen14773806
Ref: 498a14773806
Ref: library/dataclasses frozen-instances14773806
Ref: 499514773806
Node: Inheritance14774403
Ref: library/dataclasses dataclasses-inheritance14774563
Ref: 499614774563
Ref: library/dataclasses inheritance14774563
Ref: 499714774563
Node: Re-ordering of keyword-only parameters in __init__14775619
Ref: library/dataclasses re-ordering-of-keyword-only-parameters-in-init14775788
Ref: 499814775788
Node: Default factory functions14777043
Ref: library/dataclasses default-factory-functions14777223
Ref: 499914777223
Node: Mutable default values14777841
Ref: library/dataclasses mutable-default-values14777994
Ref: 499a14777994
Node: Descriptor-typed fields14780024
Ref: library/dataclasses descriptor-typed-fields14780143
Ref: 499b14780143
Node: contextlib — Utilities for with-statement contexts14782121
Ref: library/contextlib doc14782308
Ref: 499c14782308
Ref: library/contextlib contextlib-utilities-for-with-statement-contexts14782308
Ref: 499d14782308
Ref: library/contextlib module-contextlib14782308
Ref: 2714782308
Ref: library/contextlib translation-repo14782308
Ref: 499e14782308
Ref: contextlib — Utilities for with-statement contexts-Footnote-114782976
Node: Utilities14783046
Ref: library/contextlib utilities14783176
Ref: 499f14783176
Ref: library/contextlib contextlib AbstractContextManager14783248
Ref: e8c14783248
Ref: library/contextlib contextlib AbstractAsyncContextManager14783745
Ref: d2214783745
Ref: library/contextlib contextlib contextmanager14784260
Ref: 140a14784260
Ref: library/contextlib contextlib asynccontextmanager14787285
Ref: d2114787285
Ref: library/contextlib contextlib closing14789319
Ref: 159114789319
Ref: library/contextlib contextlib aclosing14790560
Ref: 9f014790560
Ref: library/contextlib simplifying-support-for-single-optional-context-managers14791681
Ref: 49a014791681
Ref: library/contextlib contextlib nullcontext14791681
Ref: 9f114791681
Ref: library/contextlib contextlib suppress14793397
Ref: 112a14793397
Ref: library/contextlib contextlib redirect_stdout14794974
Ref: fe914794974
Ref: library/contextlib contextlib redirect_stderr14796449
Ref: fe814796449
Ref: library/contextlib contextlib chdir14796713
Ref: 82114796713
Ref: library/contextlib contextlib ContextDecorator14797444
Ref: 140914797444
Ref: library/contextlib contextlib AsyncContextDecorator14799886
Ref: 9f214799886
Ref: library/contextlib contextlib ExitStack14800979
Ref: d2014800979
Ref: library/contextlib contextlib ExitStack enter_context14802977
Ref: 7ef14802977
Ref: library/contextlib contextlib ExitStack push14803572
Ref: 49a214803572
Ref: library/contextlib contextlib ExitStack callback14804464
Ref: c7814804464
Ref: library/contextlib contextlib ExitStack pop_all14804920
Ref: 49a314804920
Ref: library/contextlib contextlib ExitStack close14805970
Ref: 49a414805970
Ref: library/contextlib contextlib AsyncExitStack14806258
Ref: d2314806258
Ref: library/contextlib contextlib AsyncExitStack enter_async_context14806626
Ref: 7f014806626
Ref: library/contextlib contextlib AsyncExitStack push_async_exit14806966
Ref: 49a614806966
Ref: library/contextlib contextlib AsyncExitStack push_async_callback14807145
Ref: c7914807145
Ref: library/contextlib contextlib AsyncExitStack aclose14807311
Ref: 49a514807311
Node: Examples and Recipes<3>14807920
Ref: library/contextlib examples-and-recipes14808109
Ref: 49a714808109
Node: Supporting a variable number of context managers14808557
Ref: library/contextlib supporting-a-variable-number-of-context-managers14808716
Ref: 49a814808716
Node: Catching exceptions from __enter__ methods14809758
Ref: library/contextlib catching-exceptions-from-enter-methods14809968
Ref: 49a914809968
Node: Cleaning up in an __enter__ implementation14811116
Ref: library/contextlib cleaning-up-in-an-enter-implementation14811329
Ref: 49aa14811329
Node: Replacing any use of try-finally and flag variables14813232
Ref: library/contextlib replacing-any-use-of-try-finally-and-flag-variables14813450
Ref: 49ab14813450
Node: Using a context manager as a function decorator14815962
Ref: library/contextlib using-a-context-manager-as-a-function-decorator14816129
Ref: 49ac14816129
Ref: Using a context manager as a function decorator-Footnote-114817967
Node: Single use reusable and reentrant context managers14818009
Ref: library/contextlib single-use-reusable-and-reentrant-cms14818180
Ref: 112c14818180
Ref: library/contextlib single-use-reusable-and-reentrant-context-managers14818180
Ref: 49ad14818180
Node: Reentrant context managers14819718
Ref: library/contextlib reentrant-cms14819865
Ref: 49a114819865
Ref: library/contextlib reentrant-context-managers14819865
Ref: 49ae14819865
Node: Reusable context managers14821401
Ref: library/contextlib reusable-cms14821548
Ref: 49af14821548
Ref: library/contextlib reusable-context-managers14821548
Ref: 49b014821548
Node: abc — Abstract Base Classes14824222
Ref: library/abc doc14824405
Ref: 49b114824405
Ref: library/abc abc-abstract-base-classes14824405
Ref: 49b214824405
Ref: library/abc module-abc14824405
Ref: 414824405
Ref: library/abc translation-repo14824405
Ref: 49b314824405
Ref: library/abc abc ABC14825397
Ref: 111c14825397
Ref: library/abc abc ABCMeta14826217
Ref: 111d14826217
Ref: library/abc abc ABCMeta register14826990
Ref: 129014826990
Ref: library/abc abc ABCMeta __subclasshook__14827676
Ref: 297e14827676
Ref: library/abc abc abstractmethod14830589
Ref: 128d14830589
Ref: library/abc abc abstractclassmethod14833733
Ref: 128e14833733
Ref: library/abc abc abstractstaticmethod14834453
Ref: 128f14834453
Ref: library/abc abc abstractproperty14835175
Ref: 128c14835175
Ref: library/abc abc get_cache_token14836579
Ref: 111b14836579
Ref: library/abc abc update_abstractmethods14836959
Ref: 49b414836959
Ref: abc — Abstract Base Classes-Footnote-114837615
Ref: abc — Abstract Base Classes-Footnote-214837678
Ref: abc — Abstract Base Classes-Footnote-314837720
Ref: abc — Abstract Base Classes-Footnote-414837762
Node: atexit — Exit handlers14837869
Ref: library/atexit doc14838049
Ref: 49b514838049
Ref: library/atexit atexit-exit-handlers14838049
Ref: 49b614838049
Ref: library/atexit module-atexit14838049
Ref: d14838049
Ref: library/atexit translation-repo14838049
Ref: 49b714838049
Ref: library/atexit atexit register14839071
Ref: a8014839071
Ref: library/atexit atexit unregister14840687
Ref: 176614840687
Node: atexit Example14841381
Ref: library/atexit atexit-example14841456
Ref: 49b814841456
Ref: library/atexit id114841456
Ref: 49b914841456
Node: traceback — Print or retrieve a stack traceback14842819
Ref: library/traceback doc14843013
Ref: 49ba14843013
Ref: library/traceback module-traceback14843013
Ref: 10414843013
Ref: library/traceback traceback-print-or-retrieve-a-stack-traceback14843013
Ref: 49bb14843013
Ref: library/traceback translation-repo14843013
Ref: 49bc14843013
Ref: traceback — Print or retrieve a stack traceback-Footnote-114845144
Node: Module-Level Functions<2>14845213
Ref: library/traceback module-level-functions14845359
Ref: 49bd14845359
Ref: library/traceback traceback print_tb14845426
Ref: 108714845426
Ref: library/traceback traceback print_exception14846378
Ref: a5114846378
Ref: library/traceback traceback print_exc14847911
Ref: 1c0c14847911
Ref: library/traceback traceback print_last14848094
Ref: 49be14848094
Ref: library/traceback traceback print_stack14848400
Ref: 108814848400
Ref: library/traceback traceback extract_tb14848968
Ref: 49bf14848968
Ref: library/traceback traceback extract_stack14849616
Ref: 49c414849616
Ref: library/traceback traceback print_list14849930
Ref: 18d714849930
Ref: library/traceback traceback format_list14850233
Ref: 49c514850233
Ref: library/traceback traceback format_exception_only14850743
Ref: a5014850743
Ref: library/traceback traceback format_exception14852141
Ref: a4f14852141
Ref: library/traceback traceback format_exc14852891
Ref: 49c614852891
Ref: library/traceback traceback format_tb14853051
Ref: 488914853051
Ref: library/traceback traceback format_stack14853167
Ref: 49c714853167
Ref: library/traceback traceback clear_frames14853292
Ref: 11d614853292
Ref: library/traceback traceback walk_stack14853537
Ref: 108314853537
Ref: library/traceback traceback walk_tb14854091
Ref: 108414854091
Node: TracebackException Objects14854333
Ref: library/traceback tracebackexception-objects14854508
Ref: 49c914854508
Ref: library/traceback traceback TracebackException14854991
Ref: 56314854991
Ref: library/traceback traceback TracebackException __cause__14856309
Ref: 49cb14856309
Ref: library/traceback traceback TracebackException __context__14856417
Ref: 49ca14856417
Ref: library/traceback traceback TracebackException exceptions14856539
Ref: 49cd14856539
Ref: library/traceback traceback TracebackException __suppress_context__14856818
Ref: 49cc14856818
Ref: library/traceback traceback TracebackException __notes__14856954
Ref: 49ce14856954
Ref: library/traceback traceback TracebackException stack14857264
Ref: 49cf14857264
Ref: library/traceback traceback TracebackException exc_type14857358
Ref: 56414857358
Ref: library/traceback traceback TracebackException exc_type_str14857478
Ref: 56214857478
Ref: library/traceback traceback TracebackException filename14857612
Ref: 49d014857612
Ref: library/traceback traceback TracebackException lineno14857713
Ref: 49d114857713
Ref: library/traceback traceback TracebackException end_lineno14857814
Ref: 49d214857814
Ref: library/traceback traceback TracebackException text14858002
Ref: 49d314858002
Ref: library/traceback traceback TracebackException offset14858094
Ref: 49d414858094
Ref: library/traceback traceback TracebackException end_offset14858214
Ref: 49d514858214
Ref: library/traceback traceback TracebackException msg14858411
Ref: 49d614858411
Ref: library/traceback traceback TracebackException from_exception14858495
Ref: 49d714858495
Ref: library/traceback traceback TracebackException print14858879
Ref: 8b414858879
Ref: library/traceback traceback TracebackException format14859087
Ref: 49d814859087
Ref: library/traceback traceback TracebackException format_exception_only14859538
Ref: 56514859538
Node: StackSummary Objects14860596
Ref: library/traceback stacksummary-objects14860766
Ref: 49d914860766
Ref: library/traceback traceback StackSummary14860933
Ref: 108514860933
Ref: library/traceback traceback StackSummary extract14860969
Ref: 49c814860969
Ref: library/traceback traceback StackSummary from_list14861969
Ref: 49da14861969
Ref: library/traceback traceback StackSummary format14862274
Ref: 49db14862274
Ref: library/traceback traceback StackSummary format_frame_summary14862911
Ref: 8b314862911
Node: FrameSummary Objects14863316
Ref: library/traceback framesummary-objects14863504
Ref: 49dc14863504
Ref: library/traceback traceback FrameSummary14863692
Ref: 108614863692
Ref: library/traceback traceback FrameSummary filename14864611
Ref: 49c014864611
Ref: library/traceback traceback FrameSummary lineno14864814
Ref: 49c114864814
Ref: library/traceback traceback FrameSummary name14864904
Ref: 49c214864904
Ref: library/traceback traceback FrameSummary line14865040
Ref: 49c314865040
Ref: library/traceback traceback FrameSummary end_lineno14865249
Ref: 49dd14865249
Ref: library/traceback traceback FrameSummary colno14865537
Ref: 49de14865537
Ref: library/traceback traceback FrameSummary end_colno14865698
Ref: 49df14865698
Node: Examples of Using the Module-Level Functions14865868
Ref: library/traceback examples-of-using-the-module-level-functions14866072
Ref: 49e014866072
Ref: library/traceback traceback-example14866072
Ref: 49e114866072
Node: Examples of Using TracebackException14871517
Ref: library/traceback examples-of-using-tracebackexception14871692
Ref: 49e214871692
Node: __future__ — Future statement definitions14874348
Ref: library/__future__ doc14874552
Ref: 49e314874552
Ref: library/__future__ future-future-statement-definitions14874552
Ref: 49e414874552
Ref: library/__future__ module-__future__14874552
Ref: 014874552
Ref: library/__future__ translation-repo14874552
Ref: 49e514874552
Ref: __future__ — Future statement definitions-Footnote-114876090
Node: Module Contents<5>14876160
Ref: library/__future__ module-contents14876258
Ref: 49e614876258
Ref: library/__future__ future__ nested_scopes14876912
Ref: 49e714876912
Ref: library/__future__ future__ generators14877313
Ref: 49e814877313
Ref: library/__future__ future__ division14877707
Ref: 49e914877707
Ref: library/__future__ future__ absolute_import14878114
Ref: 49ea14878114
Ref: library/__future__ future__ with_statement14878622
Ref: 49eb14878622
Ref: library/__future__ future__ print_function14879023
Ref: 49ec14879023
Ref: library/__future__ future__ unicode_literals14879422
Ref: 49ed14879422
Ref: library/__future__ future__ generator_stop14879829
Ref: 49ee14879829
Ref: library/__future__ future__ annotations14880246
Ref: 49ef14880246
Ref: library/__future__ future-classes14880899
Ref: 49f014880899
Ref: library/__future__ future__ _Feature14880899
Ref: 25a414880899
Ref: library/__future__ future__ _Feature getOptionalRelease14881547
Ref: 49f114881547
Ref: library/__future__ future__ _Feature getMandatoryRelease14881681
Ref: 49f214881681
Ref: library/__future__ future__ _Feature compiler_flag14882269
Ref: 237914882269
Ref: Module Contents<5>-Footnote-114882858
Ref: Module Contents<5>-Footnote-214882900
Ref: Module Contents<5>-Footnote-314882942
Ref: Module Contents<5>-Footnote-414882984
Ref: Module Contents<5>-Footnote-514883026
Ref: Module Contents<5>-Footnote-614883068
Ref: Module Contents<5>-Footnote-714883110
Ref: Module Contents<5>-Footnote-814883152
Ref: Module Contents<5>-Footnote-914883194
Ref: Module Contents<5>-Footnote-1014883511
Ref: Module Contents<5>-Footnote-1114883554
Ref: Module Contents<5>-Footnote-1214883597
Node: gc — Garbage Collector interface14883640
Ref: library/gc doc14883827
Ref: 49f314883827
Ref: library/gc gc-garbage-collector-interface14883827
Ref: 49f414883827
Ref: library/gc module-gc14883827
Ref: 6414883827
Ref: library/gc translation-repo14883827
Ref: 49f514883827
Ref: library/gc gc enable14884754
Ref: 49f614884754
Ref: library/gc gc disable14884825
Ref: 49f714884825
Ref: library/gc gc isenabled14884898
Ref: 49f814884898
Ref: library/gc gc collect14884989
Ref: 1b314884989
Ref: library/gc gc set_debug14886152
Ref: 49f914886152
Ref: library/gc gc get_debug14886419
Ref: 49fa14886419
Ref: library/gc gc get_objects14886498
Ref: a0614886498
Ref: library/gc gc get_stats14887116
Ref: 2dc14887116
Ref: library/gc gc set_threshold14887813
Ref: 2da14887813
Ref: library/gc gc get_count14889417
Ref: 2db14889417
Ref: library/gc gc get_threshold14889542
Ref: 2d914889542
Ref: library/gc gc get_referrers14889687
Ref: a0714889687
Ref: library/gc gc get_referents14890731
Ref: a0814890731
Ref: library/gc gc is_tracked14891464
Ref: 151514891464
Ref: library/gc gc is_finalized14892236
Ref: afb14892236
Ref: library/gc gc freeze14892748
Ref: d3014892748
Ref: library/gc gc unfreeze14893585
Ref: d3114893585
Ref: library/gc gc get_freeze_count14893746
Ref: d3214893746
Ref: library/gc gc garbage14893991
Ref: 13c914893991
Ref: library/gc gc callbacks14894870
Ref: 12cf14894870
Ref: library/gc gc DEBUG_STATS14896191
Ref: 49fc14896191
Ref: library/gc gc DEBUG_COLLECTABLE14896334
Ref: 49fd14896334
Ref: library/gc gc DEBUG_UNCOLLECTABLE14896420
Ref: 13ca14896420
Ref: library/gc gc DEBUG_SAVEALL14896806
Ref: 49fb14896806
Ref: library/gc gc DEBUG_LEAK14896998
Ref: 49fe14896998
Ref: gc — Garbage Collector interface-Footnote-114897242
Ref: gc — Garbage Collector interface-Footnote-214897329
Node: inspect — Inspect live objects14897371
Ref: library/inspect doc14897576
Ref: 49ff14897576
Ref: library/inspect inspect-inspect-live-objects14897576
Ref: 4a0014897576
Ref: library/inspect translation-repo14897576
Ref: 4a0114897576
Ref: library/inspect module-inspect14897665
Ref: 8214897665
Ref: inspect — Inspect live objects-Footnote-114898859
Node: Types and members14898926
Ref: library/inspect inspect-types14899043
Ref: 1d7a14899043
Ref: library/inspect types-and-members14899043
Ref: 4a0214899043
Ref: library/inspect inspect getmembers14918952
Ref: 1bd914918952
Ref: library/inspect inspect getmembers_static14919565
Ref: 85a14919565
Ref: library/inspect inspect getmodulename14920304
Ref: f3614920304
Ref: library/inspect inspect ismodule14920986
Ref: 4a0414920986
Ref: library/inspect inspect isclass14921078
Ref: 4a0514921078
Ref: library/inspect inspect ismethod14921217
Ref: 4a0614921217
Ref: library/inspect inspect ispackage14921333
Ref: 23214921333
Ref: library/inspect inspect isfunction14921467
Ref: 4a0714921467
Ref: library/inspect inspect isgeneratorfunction14921645
Ref: 1b4314921645
Ref: library/inspect inspect isgenerator14922126
Ref: 4a0814922126
Ref: library/inspect inspect iscoroutinefunction14922224
Ref: 30d14922224
Ref: library/inspect inspect markcoroutinefunction14923089
Ref: 6b914923089
Ref: library/inspect inspect iscoroutine14923681
Ref: 101914923681
Ref: library/inspect inspect isawaitable14923869
Ref: 101a14923869
Ref: library/inspect inspect isasyncgenfunction14924345
Ref: 1b4414924345
Ref: library/inspect inspect isasyncgen14925065
Ref: 4a0914925065
Ref: library/inspect inspect istraceback14925295
Ref: 4a0a14925295
Ref: library/inspect inspect isframe14925393
Ref: 4a0b14925393
Ref: library/inspect inspect iscode14925483
Ref: 4a0c14925483
Ref: library/inspect inspect isbuiltin14925571
Ref: 4a0d14925571
Ref: library/inspect inspect ismethodwrapper14925707
Ref: 85b14925707
Ref: library/inspect inspect isroutine14926012
Ref: 1bc514926012
Ref: library/inspect inspect isabstract14926147
Ref: 4a0e14926147
Ref: library/inspect inspect ismethoddescriptor14926255
Ref: 193614926255
Ref: library/inspect inspect isdatadescriptor14927469
Ref: 4a0f14927469
Ref: library/inspect inspect isgetsetdescriptor14928099
Ref: 4a1014928099
Ref: library/inspect inspect ismemberdescriptor14928464
Ref: 4a1114928464
Node: Retrieving source code14928840
Ref: library/inspect inspect-source14929015
Ref: 4a1214929015
Ref: library/inspect retrieving-source-code14929015
Ref: 4a1314929015
Ref: library/inspect inspect getdoc14929082
Ref: bef14929082
Ref: library/inspect inspect getcomments14929595
Ref: 192014929595
Ref: library/inspect inspect getfile14930019
Ref: 1e6d14930019
Ref: library/inspect inspect getmodule14930253
Ref: 1b5514930253
Ref: library/inspect inspect getsourcefile14930413
Ref: 1b5614930413
Ref: library/inspect inspect getsourcelines14930714
Ref: 179f14930714
Ref: library/inspect inspect getsource14931435
Ref: 17ab14931435
Ref: library/inspect inspect cleandoc14931992
Ref: 1a1414931992
Node: Introspecting callables with the Signature object14932403
Ref: library/inspect inspect-signature-object14932585
Ref: 4a1414932585
Ref: library/inspect introspecting-callables-with-the-signature-object14932585
Ref: 4a1514932585
Ref: library/inspect inspect signature14932916
Ref: 22f14932916
Ref: library/inspect inspect Signature14935984
Ref: 4e414935984
Ref: library/inspect inspect Signature empty14937103
Ref: 4a1814937103
Ref: library/inspect inspect Signature parameters14937223
Ref: 4a1614937223
Ref: library/inspect inspect Signature return_annotation14937723
Ref: 4a1914937723
Ref: library/inspect inspect Signature bind14937938
Ref: 187a14937938
Ref: library/inspect inspect Signature bind_partial14938216
Ref: 4a1a14938216
Ref: library/inspect inspect Signature replace14938593
Ref: 4a1714938593
Ref: library/inspect inspect Signature format14939467
Ref: 23114939467
Ref: library/inspect inspect Signature from_callable14940373
Ref: 94314940373
Ref: library/inspect inspect Parameter14941094
Ref: 4e514941094
Ref: library/inspect inspect Parameter empty14941512
Ref: 4a1c14941512
Ref: library/inspect inspect Parameter name14941643
Ref: 4a1d14941643
Ref: library/inspect inspect Parameter default14942130
Ref: 4a1e14942130
Ref: library/inspect inspect Parameter annotation14942321
Ref: 4a1f14942321
Ref: library/inspect inspect Parameter kind14942509
Ref: 4a2014942509
Ref: library/inspect inspect Parameter kind description14945413
Ref: 4a2114945413
Ref: library/inspect inspect Parameter replace14945963
Ref: 4a1b14945963
Ref: library/inspect inspect BoundArguments14947102
Ref: 126b14947102
Ref: library/inspect inspect BoundArguments arguments14947307
Ref: b0a14947307
Ref: library/inspect inspect BoundArguments args14948162
Ref: 4a2214948162
Ref: library/inspect inspect BoundArguments kwargs14948313
Ref: 4a2314948313
Ref: library/inspect inspect BoundArguments signature14948558
Ref: 4a2414948558
Ref: library/inspect inspect BoundArguments apply_defaults14948656
Ref: 101814948656
Ref: Introspecting callables with the Signature object-Footnote-114949639
Node: Classes and functions<2>14949681
Ref: library/inspect classes-and-functions14949862
Ref: 4a2514949862
Ref: library/inspect inspect-classes-functions14949862
Ref: 4a2614949862
Ref: library/inspect inspect getclasstree14949927
Ref: 4a2714949927
Ref: library/inspect inspect getfullargspec14950506
Ref: 94214950506
Ref: library/inspect inspect getargvalues14952889
Ref: 10c114952889
Ref: library/inspect inspect formatargvalues14953394
Ref: 10c214953394
Ref: library/inspect inspect getmro14953865
Ref: 4a2814953865
Ref: library/inspect inspect getcallargs14954229
Ref: 10c014954229
Ref: library/inspect inspect getclosurevars14955594
Ref: 12dd14955594
Ref: library/inspect inspect unwrap14956312
Ref: 115e14956312
Ref: library/inspect inspect get_annotations14957048
Ref: a1614957048
Node: The interpreter stack14957804
Ref: library/inspect inspect-stack14957966
Ref: 4a2914957966
Ref: library/inspect the-interpreter-stack14957966
Ref: 4a2a14957966
Ref: library/inspect inspect FrameInfo14958288
Ref: 85d14958288
Ref: library/inspect inspect FrameInfo frame14958319
Ref: 4a2b14958319
Ref: library/inspect inspect FrameInfo filename14958418
Ref: 4a2c14958418
Ref: library/inspect inspect FrameInfo lineno14958564
Ref: 4a2d14958564
Ref: library/inspect inspect FrameInfo function14958730
Ref: 4a2e14958730
Ref: library/inspect inspect FrameInfo code_context14958863
Ref: 4a2f14958863
Ref: library/inspect inspect FrameInfo index14959031
Ref: 4a3014959031
Ref: library/inspect inspect FrameInfo positions14959163
Ref: 4a3114959163
Ref: library/inspect inspect Traceback14959717
Ref: 85e14959717
Ref: library/inspect inspect Traceback filename14959748
Ref: 4a3214959748
Ref: library/inspect inspect Traceback lineno14959897
Ref: 4a3314959897
Ref: library/inspect inspect Traceback function14960066
Ref: 4a3414960066
Ref: library/inspect inspect Traceback code_context14960202
Ref: 4a3514960202
Ref: library/inspect inspect Traceback index14960373
Ref: 4a3614960373
Ref: library/inspect inspect Traceback positions14960505
Ref: 4a3714960505
Ref: library/inspect inspect getframeinfo14962446
Ref: 86014962446
Ref: library/inspect inspect getouterframes14962718
Ref: 86114962718
Ref: library/inspect inspect getinnerframes14963335
Ref: 86214963335
Ref: library/inspect inspect currentframe14963948
Ref: 8f214963948
Ref: library/inspect inspect stack14964363
Ref: 86314964363
Ref: library/inspect inspect trace14964872
Ref: 86414964872
Node: Fetching attributes statically14965470
Ref: library/inspect fetching-attributes-statically14965674
Ref: 4a3814965674
Ref: library/inspect inspect getattr_static14966256
Ref: 6bd14966256
Node: Current State of Generators Coroutines and Asynchronous Generators14968063
Ref: library/inspect current-state-of-generators-coroutines-and-asynchronous-generators14968268
Ref: 4a3914968268
Ref: library/inspect inspect getgeneratorstate14968750
Ref: 143e14968750
Ref: library/inspect inspect getcoroutinestate14969145
Ref: 101c14969145
Ref: library/inspect inspect getasyncgenstate14969761
Ref: 6bb14969761
Ref: library/inspect inspect getgeneratorlocals14970633
Ref: 12de14970633
Ref: library/inspect inspect getcoroutinelocals14971525
Ref: 101b14971525
Ref: library/inspect inspect getasyncgenlocals14971763
Ref: 6bc14971763
Node: Code Objects Bit Flags14972051
Ref: library/inspect code-objects-bit-flags14972238
Ref: 4a3a14972238
Ref: library/inspect inspect-module-co-flags14972238
Ref: 237814972238
Ref: library/inspect inspect CO_OPTIMIZED14972408
Ref: 4a3b14972408
Ref: library/inspect inspect CO_NEWLOCALS14972495
Ref: 4a3c14972495
Ref: library/inspect inspect CO_VARARGS14972646
Ref: 4a3d14972646
Ref: library/inspect inspect CO_VARKEYWORDS14972754
Ref: 4a3e14972754
Ref: library/inspect inspect CO_NESTED14972866
Ref: 4a3f14972866
Ref: library/inspect inspect CO_GENERATOR14972960
Ref: 4a4014972960
Ref: library/inspect inspect CO_COROUTINE14973135
Ref: 4a4114973135
Ref: library/inspect inspect CO_ITERABLE_COROUTINE14973372
Ref: 4a4214973372
Ref: library/inspect inspect CO_ASYNC_GENERATOR14973687
Ref: 4a4314973687
Ref: library/inspect inspect CO_HAS_DOCSTRING14973958
Ref: 237a14973958
Ref: library/inspect inspect CO_METHOD14974182
Ref: 4a4414974182
Ref: Code Objects Bit Flags-Footnote-114974702
Ref: Code Objects Bit Flags-Footnote-214974744
Ref: Code Objects Bit Flags-Footnote-314974786
Node: Buffer flags14974828
Ref: library/inspect buffer-flags14974975
Ref: 4a4514974975
Ref: library/inspect inspect BufferFlags14975022
Ref: 68e14975022
Ref: library/inspect inspect BufferFlags SIMPLE14975333
Ref: 4a4714975333
Ref: library/inspect inspect BufferFlags WRITABLE14975361
Ref: 4a4814975361
Ref: library/inspect inspect BufferFlags FORMAT14975391
Ref: 4a4914975391
Ref: library/inspect inspect BufferFlags ND14975419
Ref: 4a4a14975419
Ref: library/inspect inspect BufferFlags STRIDES14975443
Ref: 4a4b14975443
Ref: library/inspect inspect BufferFlags C_CONTIGUOUS14975472
Ref: 4a4c14975472
Ref: library/inspect inspect BufferFlags F_CONTIGUOUS14975506
Ref: 4a4d14975506
Ref: library/inspect inspect BufferFlags ANY_CONTIGUOUS14975540
Ref: 4a4e14975540
Ref: library/inspect inspect BufferFlags INDIRECT14975576
Ref: 4a4f14975576
Ref: library/inspect inspect BufferFlags CONTIG14975606
Ref: 4a5014975606
Ref: library/inspect inspect BufferFlags CONTIG_RO14975634
Ref: 4a5114975634
Ref: library/inspect inspect BufferFlags STRIDED14975665
Ref: 4a5214975665
Ref: library/inspect inspect BufferFlags STRIDED_RO14975694
Ref: 4a5314975694
Ref: library/inspect inspect BufferFlags RECORDS14975726
Ref: 4a5414975726
Ref: library/inspect inspect BufferFlags RECORDS_RO14975755
Ref: 4a5514975755
Ref: library/inspect inspect BufferFlags FULL14975787
Ref: 4a5614975787
Ref: library/inspect inspect BufferFlags FULL_RO14975813
Ref: 4a5714975813
Ref: library/inspect inspect BufferFlags READ14975842
Ref: 18dd14975842
Ref: library/inspect inspect BufferFlags WRITE14975868
Ref: 18de14975868
Node: Command-line interface<10>14975924
Ref: library/inspect command-line-interface14976040
Ref: 4a5814976040
Ref: library/inspect inspect-module-cli14976040
Ref: 115d14976040
Ref: library/inspect cmdoption-inspect-details14976417
Ref: 4a5914976417
Node: annotationlib — Functionality for introspecting annotations14976524
Ref: library/annotationlib doc14976736
Ref: 4a5a14976736
Ref: library/annotationlib annotationlib-functionality-for-introspecting-annotations14976736
Ref: 4a5b14976736
Ref: library/annotationlib module-annotationlib14976736
Ref: 614976736
Ref: library/annotationlib translation-repo14976736
Ref: 4a5c14976736
Ref: annotationlib — Functionality for introspecting annotations-Footnote-114979734
Ref: annotationlib — Functionality for introspecting annotations-Footnote-214979807
Ref: annotationlib — Functionality for introspecting annotations-Footnote-314979849
Ref: annotationlib — Functionality for introspecting annotations-Footnote-414979891
Ref: annotationlib — Functionality for introspecting annotations-Footnote-514979933
Node: Annotation semantics14979985
Ref: library/annotationlib annotation-semantics14980122
Ref: 4a5d14980122
Ref: Annotation semantics-Footnote-114982771
Ref: Annotation semantics-Footnote-214982813
Ref: Annotation semantics-Footnote-314982855
Ref: Annotation semantics-Footnote-414982897
Ref: Annotation semantics-Footnote-514982939
Ref: Annotation semantics-Footnote-614982981
Ref: Annotation semantics-Footnote-714983023
Ref: Annotation semantics-Footnote-814983065
Ref: Annotation semantics-Footnote-914983107
Node: Classes<4>14983149
Ref: library/annotationlib classes14983308
Ref: 4a5e14983308
Ref: library/annotationlib annotationlib Format14983345
Ref: 23014983345
Ref: library/annotationlib annotationlib Format VALUE14983681
Ref: 15e14983681
Ref: library/annotationlib annotationlib Format VALUE_WITH_FAKE_GLOBALS14983797
Ref: 4a5f14983797
Ref: library/annotationlib annotationlib Format FORWARDREF14984370
Ref: 15f14984370
Ref: library/annotationlib annotationlib Format STRING14984679
Ref: 16014984679
Ref: library/annotationlib annotationlib ForwardRef14985071
Ref: 175d14985071
Ref: library/annotationlib annotationlib ForwardRef __forward_arg__14985460
Ref: 4a6014985460
Ref: library/annotationlib annotationlib ForwardRef evaluate14985681
Ref: 179a14985681
Node: Functions<11>14988806
Ref: library/annotationlib functions14988955
Ref: 4a6114988955
Ref: library/annotationlib annotationlib annotations_to_string14988996
Ref: 4a6214988996
Ref: library/annotationlib annotationlib call_annotate_function14989839
Ref: 17a614989839
Ref: library/annotationlib annotationlib call_evaluate_function14991074
Ref: 44d714991074
Ref: library/annotationlib annotationlib get_annotate_from_class_namespace14992989
Ref: 45b14992989
Ref: library/annotationlib annotationlib get_annotations14993561
Ref: 45914993561
Ref: library/annotationlib annotationlib type_repr14998878
Ref: 183e14998878
Ref: Functions<11>-Footnote-114999569
Node: Recipes<3>14999660
Ref: library/annotationlib recipes14999831
Ref: 4a6414999831
Node: Using annotations in a metaclass14999915
Ref: library/annotationlib annotationlib-metaclass14999994
Ref: 4a6314999994
Ref: library/annotationlib using-annotations-in-a-metaclass14999994
Ref: 4a6514999994
Node: Limitations of the STRING format15003128
Ref: library/annotationlib limitations-of-the-string-format15003322
Ref: 4a6615003322
Node: Limitations of the FORWARDREF format15007122
Ref: library/annotationlib limitations-of-the-forwardref-format15007356
Ref: 4a8b15007356
Node: Security implications of introspecting annotations15008456
Ref: library/annotationlib annotationlib-security15008649
Ref: 44ff15008649
Ref: library/annotationlib security-implications-of-introspecting-annotations15008649
Ref: 4a8c15008649
Node: site — Site-specific configuration hook15009873
Ref: library/site doc15010044
Ref: 4a8d15010044
Ref: library/site module-site15010044
Ref: cc15010044
Ref: library/site site-site-specific-configuration-hook15010044
Ref: 4a8e15010044
Ref: library/site translation-repo15010044
Ref: 4a8f15010044
Ref: library/site site-virtual-environments-configuration15012402
Ref: 489c15012402
Ref: site — Site-specific configuration hook-Footnote-115015267
Node: sitecustomize15015331
Ref: library/site module-sitecustomize15015444
Ref: cd15015444
Ref: library/site sitecustomize15015444
Ref: 4a9015015444
Node: usercustomize15016210
Ref: library/site module-usercustomize15016354
Ref: 11415016354
Ref: library/site usercustomize15016354
Ref: 4a9115016354
Node: Readline configuration15017164
Ref: library/site readline-configuration15017313
Ref: 4a9315017313
Ref: library/site rlcompleter-config15017313
Ref: 11cb15017313
Node: Module contents<5>15017988
Ref: library/site module-contents15018150
Ref: 4a9415018150
Ref: library/site site PREFIXES15018203
Ref: 4a9515018203
Ref: library/site site ENABLE_USER_SITE15018284
Ref: 4a9215018284
Ref: library/site site USER_SITE15018722
Ref: 210f15018722
Ref: library/site site USER_BASE15019337
Ref: 152415019337
Ref: library/site site main15019897
Ref: 211015019897
Ref: library/site site addsitedir15020252
Ref: 225b15020252
Ref: library/site site getsitepackages15020474
Ref: 144615020474
Ref: library/site site getuserbase15020610
Ref: 144715020610
Ref: library/site site getusersitepackages15020857
Ref: 144815020857
Node: Command-line interface<11>15021259
Ref: library/site command-line-interface15021390
Ref: 4a9615021390
Ref: library/site site-commandline15021390
Ref: 4a9715021390
Ref: library/site cmdoption-site-user-base15021938
Ref: 4a9815021938
Ref: library/site cmdoption-site-user-site15022012
Ref: 4a9915022012
Ref: Command-line interface<11>-Footnote-115022887
Node: Custom Python Interpreters15022929
Ref: library/custominterp doc15023077
Ref: 4a9a15023077
Ref: library/custominterp custom-python-interpreters15023077
Ref: 4a9b15023077
Ref: library/custominterp custominterp15023077
Ref: 4a9c15023077
Ref: library/custominterp translation-repo15023077
Ref: 4a9d15023077
Node: code — Interpreter base classes15023662
Ref: library/code doc15023797
Ref: 4a9e15023797
Ref: library/code code-interpreter-base-classes15023797
Ref: 4a9f15023797
Ref: library/code module-code15023797
Ref: 1b15023797
Ref: library/code code InteractiveInterpreter15024215
Ref: 192b15024215
Ref: library/code code InteractiveConsole15024994
Ref: 27ea15024994
Ref: library/code code interact15025558
Ref: 187815025558
Ref: library/code code compile_command15026505
Ref: 4aa215026505
Ref: code — Interpreter base classes-Footnote-115027791
Node: Interactive Interpreter Objects15027855
Ref: library/code interactive-interpreter-objects15027992
Ref: 4aa315027992
Ref: library/code interpreter-objects15027992
Ref: 4aa415027992
Ref: library/code code InteractiveInterpreter runsource15028075
Ref: 4aa515028075
Ref: library/code code InteractiveInterpreter runcode15029362
Ref: 4aa715029362
Ref: library/code code InteractiveInterpreter showsyntaxerror15029821
Ref: 4aa615029821
Ref: library/code code InteractiveInterpreter showtraceback15030295
Ref: fd015030295
Ref: library/code code InteractiveInterpreter write15030681
Ref: 4aa815030681
Node: Interactive Console Objects15030901
Ref: library/code console-objects15031038
Ref: 4aa915031038
Ref: library/code interactive-console-objects15031038
Ref: 4aaa15031038
Ref: library/code code InteractiveConsole interact15031302
Ref: 4aa115031302
Ref: library/code code InteractiveConsole push15032165
Ref: 4aab15032165
Ref: library/code code InteractiveConsole resetbuffer15032873
Ref: 4aac15032873
Ref: library/code code InteractiveConsole raw_input15032982
Ref: 4aa015032982
Node: codeop — Compile Python code15033343
Ref: library/codeop doc15033478
Ref: 4aad15033478
Ref: library/codeop codeop-compile-python-code15033478
Ref: 4aae15033478
Ref: library/codeop module-codeop15033478
Ref: 1d15033478
Ref: library/codeop translation-repo15033478
Ref: 4aaf15033478
Ref: library/codeop codeop compile_command15034439
Ref: 1b3b15034439
Ref: library/codeop codeop Compile15035858
Ref: 4ab015035858
Ref: library/codeop codeop CommandCompiler15036259
Ref: 4ab115036259
Ref: codeop — Compile Python code-Footnote-115036681
Node: Importing Modules15036747
Ref: library/modules doc15036896
Ref: 4ab215036896
Ref: library/modules importing-modules15036896
Ref: 4ab315036896
Ref: library/modules modules15036896
Ref: 4ab415036896
Ref: library/modules translation-repo15036896
Ref: 4ab515036896
Node: zipimport — Import modules from Zip archives15037874
Ref: library/zipimport doc15038020
Ref: 4ab615038020
Ref: library/zipimport module-zipimport15038020
Ref: 13815038020
Ref: library/zipimport zipimport-import-modules-from-zip-archives15038020
Ref: 4ab715038020
Ref: library/zipimport zipimport ZipImportError15040237
Ref: 4ab815040237
Ref: zipimport — Import modules from Zip archives-Footnote-115040529
Ref: zipimport — Import modules from Zip archives-Footnote-215040598
Ref: zipimport — Import modules from Zip archives-Footnote-315040666
Ref: zipimport — Import modules from Zip archives-Footnote-415040708
Ref: zipimport — Import modules from Zip archives-Footnote-515040750
Node: zipimporter Objects15040792
Ref: library/zipimport id115040915
Ref: 4ab915040915
Ref: library/zipimport zipimporter-objects15040915
Ref: 4aba15040915
Ref: library/zipimport zipimport zipimporter15041038
Ref: 4abb15041038
Ref: library/zipimport zipimport zipimporter create_module15041683
Ref: a6115041683
Ref: library/zipimport zipimport zipimporter exec_module15041929
Ref: 33915041929
Ref: library/zipimport zipimport zipimporter find_spec15042088
Ref: a6015042088
Ref: library/zipimport zipimport zipimporter get_code15042270
Ref: 4abc15042270
Ref: library/zipimport zipimport zipimporter get_data15042451
Ref: 4abd15042451
Ref: library/zipimport zipimport zipimporter get_filename15042741
Ref: 4abe15042741
Ref: library/zipimport zipimport zipimporter get_source15043006
Ref: 4abf15043006
Ref: library/zipimport zipimport zipimporter is_package15043296
Ref: 4ac015043296
Ref: library/zipimport zipimport zipimporter load_module15043507
Ref: 33815043507
Ref: library/zipimport zipimport zipimporter invalidate_caches15043904
Ref: a6215043904
Ref: library/zipimport zipimport zipimporter archive15044084
Ref: 4ac115044084
Ref: library/zipimport zipimport zipimporter prefix15044217
Ref: 4ac215044217
Node: Examples<34>15044624
Ref: library/zipimport examples15044747
Ref: 4ac315044747
Ref: library/zipimport zipimport-examples15044747
Ref: 4ac415044747
Node: pkgutil — Package extension utility15045413
Ref: library/pkgutil doc15045614
Ref: 4ac515045614
Ref: library/pkgutil module-pkgutil15045614
Ref: ae15045614
Ref: library/pkgutil pkgutil-package-extension-utility15045614
Ref: 4ac615045614
Ref: library/pkgutil translation-repo15045614
Ref: 4ac715045614
Ref: library/pkgutil pkgutil ModuleInfo15045899
Ref: f4a15045899
Ref: library/pkgutil pkgutil extend_path15046056
Ref: 190c15046056
Ref: library/pkgutil pkgutil get_importer15047790
Ref: 4ac815047790
Ref: library/pkgutil pkgutil iter_importers15048311
Ref: 13a115048311
Ref: library/pkgutil pkgutil iter_modules15049045
Ref: f4915049045
Ref: library/pkgutil pkgutil walk_packages15049901
Ref: dfb15049901
Ref: library/pkgutil pkgutil get_data15051484
Ref: 4ac915051484
Ref: library/pkgutil pkgutil resolve_name15052617
Ref: 4acb15052617
Ref: pkgutil — Package extension utility-Footnote-115054484
Ref: pkgutil — Package extension utility-Footnote-215054551
Ref: pkgutil — Package extension utility-Footnote-315054593
Ref: pkgutil — Package extension utility-Footnote-415054635
Ref: pkgutil — Package extension utility-Footnote-515054677
Ref: pkgutil — Package extension utility-Footnote-615054719
Node: modulefinder — Find modules used by a script15054784
Ref: library/modulefinder doc15054986
Ref: 4acc15054986
Ref: library/modulefinder module-modulefinder15054986
Ref: 9515054986
Ref: library/modulefinder modulefinder-find-modules-used-by-a-script15054986
Ref: 4acd15054986
Ref: library/modulefinder translation-repo15054986
Ref: 4ace15054986
Ref: library/modulefinder modulefinder AddPackagePath15055505
Ref: 4acf15055505
Ref: library/modulefinder modulefinder ReplacePackage15055655
Ref: 4ad015055655
Ref: library/modulefinder modulefinder ModuleFinder15055818
Ref: 1dcd15055818
Ref: library/modulefinder modulefinder ModuleFinder report15056478
Ref: 4ad215056478
Ref: library/modulefinder modulefinder ModuleFinder run_script15056693
Ref: 4ad115056693
Ref: library/modulefinder modulefinder ModuleFinder modules15056831
Ref: 4ad315056831
Ref: modulefinder — Find modules used by a script-Footnote-115057055
Node: Example usage of ModuleFinder15057127
Ref: library/modulefinder example-usage-of-modulefinder15057239
Ref: 4ad515057239
Ref: library/modulefinder modulefinder-example15057239
Ref: 4ad415057239
Node: runpy — Locating and executing Python modules15058612
Ref: library/runpy doc15058819
Ref: 4ad615058819
Ref: library/runpy module-runpy15058819
Ref: c315058819
Ref: library/runpy runpy-locating-and-executing-python-modules15058819
Ref: 4ad715058819
Ref: library/runpy translation-repo15058819
Ref: 4ad815058819
Ref: library/runpy runpy run_module15059854
Ref: 1b7f15059854
Ref: library/runpy runpy run_path15063305
Ref: 4a515063305
Ref: runpy — Locating and executing Python modules-Footnote-115067773
Ref: runpy — Locating and executing Python modules-Footnote-215067838
Ref: runpy — Locating and executing Python modules-Footnote-315067880
Ref: runpy — Locating and executing Python modules-Footnote-415067922
Ref: runpy — Locating and executing Python modules-Footnote-515067964
Ref: runpy — Locating and executing Python modules-Footnote-615068006
Ref: runpy — Locating and executing Python modules-Footnote-715068048
Ref: runpy — Locating and executing Python modules-Footnote-815068090
Node: importlib — The implementation of import15068132
Ref: library/importlib doc15068360
Ref: 4ad915068360
Ref: library/importlib importlib-the-implementation-of-import15068360
Ref: 4ada15068360
Ref: library/importlib module-importlib15068360
Ref: 7b15068360
Ref: library/importlib translation-repo15068360
Ref: 4adb15068360
Ref: importlib — The implementation of import-Footnote-115069063
Node: Introduction<12>15069142
Ref: library/importlib introduction15069259
Ref: 4adc15069259
Ref: Introduction<12>-Footnote-115071550
Ref: Introduction<12>-Footnote-215071602
Ref: Introduction<12>-Footnote-315071644
Ref: Introduction<12>-Footnote-415071686
Ref: Introduction<12>-Footnote-515071728
Ref: Introduction<12>-Footnote-615071770
Ref: Introduction<12>-Footnote-715071812
Ref: Introduction<12>-Footnote-815071854
Ref: Introduction<12>-Footnote-915071896
Ref: Introduction<12>-Footnote-1015071938
Ref: Introduction<12>-Footnote-1115071981
Ref: Introduction<12>-Footnote-1215072024
Ref: Introduction<12>-Footnote-1315072067
Node: Functions<12>15072110
Ref: library/importlib functions15072293
Ref: 4add15072293
Ref: library/importlib importlib __import__15072332
Ref: 126f15072332
Ref: library/importlib importlib import_module15072640
Ref: 73d15072640
Ref: library/importlib importlib invalidate_caches15073981
Ref: e0c15073981
Ref: library/importlib importlib reload15074619
Ref: 73e15074619
Node: importlib abc – Abstract base classes related to import15078157
Ref: library/importlib importlib-abc-abstract-base-classes-related-to-import15078372
Ref: 4ade15078372
Ref: library/importlib module-importlib abc15078372
Ref: 7c15078372
Ref: library/importlib importlib abc MetaPathFinder15079165
Ref: a7015079165
Ref: library/importlib importlib abc MetaPathFinder find_spec15079383
Ref: a6a15079383
Ref: library/importlib importlib abc MetaPathFinder invalidate_caches15080128
Ref: 4adf15080128
Ref: library/importlib importlib abc PathEntryFinder15080547
Ref: a7115080547
Ref: library/importlib importlib abc PathEntryFinder find_spec15080991
Ref: a6e15080991
Ref: library/importlib importlib abc PathEntryFinder invalidate_caches15081630
Ref: 4ae015081630
Ref: library/importlib importlib abc Loader15081930
Ref: 10c915081930
Ref: library/importlib importlib abc Loader create_module15082363
Ref: eae15082363
Ref: library/importlib importlib abc Loader exec_module15082770
Ref: a6c15082770
Ref: library/importlib importlib abc Loader load_module15083252
Ref: a6b15083252
Ref: library/importlib importlib abc ResourceLoader15085313
Ref: de415085313
Ref: library/importlib importlib abc ResourceLoader get_data15085881
Ref: 4aca15085881
Ref: library/importlib importlib abc InspectLoader15086700
Ref: 115615086700
Ref: library/importlib importlib abc InspectLoader get_code15086885
Ref: 115715086885
Ref: library/importlib importlib abc InspectLoader get_source15087473
Ref: 115a15087473
Ref: library/importlib importlib abc InspectLoader is_package15088115
Ref: 4ae215088115
Ref: library/importlib importlib abc InspectLoader source_to_code15088491
Ref: 101415088491
Ref: library/importlib importlib abc InspectLoader exec_module15089140
Ref: 121415089140
Ref: library/importlib importlib abc InspectLoader load_module15089274
Ref: 4ae315089274
Ref: library/importlib importlib abc ExecutionLoader15089501
Ref: 4ae415089501
Ref: library/importlib importlib abc ExecutionLoader get_filename15089750
Ref: 4ae515089750
Ref: library/importlib importlib abc FileLoader15090342
Ref: 127515090342
Ref: library/importlib importlib abc FileLoader name15090839
Ref: 4ae615090839
Ref: library/importlib importlib abc FileLoader path15090922
Ref: 4ae715090922
Ref: library/importlib importlib abc FileLoader load_module15090991
Ref: 4ae815090991
Ref: library/importlib importlib abc FileLoader get_filename15091210
Ref: 4ae915091210
Ref: library/importlib importlib abc FileLoader get_data15091304
Ref: 4aea15091304
Ref: library/importlib importlib abc SourceLoader15091425
Ref: 4aeb15091425
Ref: library/importlib importlib abc SourceLoader path_stats15092523
Ref: 139215092523
Ref: library/importlib importlib abc SourceLoader path_mtime15093308
Ref: 139115093308
Ref: library/importlib importlib abc SourceLoader set_data15093862
Ref: 4aec15093862
Ref: library/importlib importlib abc SourceLoader get_code15094382
Ref: 4aed15094382
Ref: library/importlib importlib abc SourceLoader exec_module15094506
Ref: 121515094506
Ref: library/importlib importlib abc SourceLoader load_module15094649
Ref: 4aee15094649
Ref: library/importlib importlib abc SourceLoader get_source15094885
Ref: 122315094885
Ref: library/importlib importlib abc SourceLoader is_package15095013
Ref: 4aef15095013
Ref: importlib abc – Abstract base classes related to import-Footnote-115095452
Ref: importlib abc – Abstract base classes related to import-Footnote-215095525
Ref: importlib abc – Abstract base classes related to import-Footnote-315095567
Ref: importlib abc – Abstract base classes related to import-Footnote-415095609
Ref: importlib abc – Abstract base classes related to import-Footnote-515095651
Node: importlib machinery – Importers and path hooks15095693
Ref: library/importlib importlib-machinery-importers-and-path-hooks15095940
Ref: 4af015095940
Ref: library/importlib module-importlib machinery15095940
Ref: 7d15095940
Ref: library/importlib importlib machinery SOURCE_SUFFIXES15096271
Ref: 73915096271
Ref: library/importlib importlib machinery DEBUG_BYTECODE_SUFFIXES15096437
Ref: 189815096437
Ref: library/importlib importlib machinery OPTIMIZED_BYTECODE_SUFFIXES15096700
Ref: 189915096700
Ref: library/importlib importlib machinery BYTECODE_SUFFIXES15096963
Ref: 73b15096963
Ref: library/importlib importlib machinery EXTENSION_SUFFIXES15097254
Ref: 73a15097254
Ref: library/importlib importlib machinery all_suffixes15097426
Ref: 4a0315097426
Ref: library/importlib importlib machinery BuiltinImporter15097862
Ref: eaf15097862
Ref: library/importlib importlib machinery FrozenImporter15098439
Ref: 122115098439
Ref: library/importlib importlib machinery WindowsRegistryFinder15098866
Ref: f2815098866
Ref: library/importlib importlib machinery PathFinder15099355
Ref: 122515099355
Ref: library/importlib importlib machinery PathFinder find_spec15099671
Ref: 121315099671
Ref: library/importlib importlib machinery PathFinder invalidate_caches15100857
Ref: e0b15100857
Ref: library/importlib importlib machinery FileFinder15101480
Ref: 127415101480
Ref: library/importlib importlib machinery FileFinder path15102788
Ref: 4af115102788
Ref: library/importlib importlib machinery FileFinder find_spec15102861
Ref: 10c815102861
Ref: library/importlib importlib machinery FileFinder invalidate_caches15103038
Ref: 4af215103038
Ref: library/importlib importlib machinery FileFinder path_hook15103118
Ref: 4af315103118
Ref: library/importlib importlib machinery SourceFileLoader15103566
Ref: 127615103566
Ref: library/importlib importlib machinery SourceFileLoader name15103861
Ref: 4af415103861
Ref: library/importlib importlib machinery SourceFileLoader path15103951
Ref: 4af515103951
Ref: library/importlib importlib machinery SourceFileLoader is_package15104017
Ref: 4af615104017
Ref: library/importlib importlib machinery SourceFileLoader path_stats15104146
Ref: 4af715104146
Ref: library/importlib importlib machinery SourceFileLoader set_data15104283
Ref: 4af815104283
Ref: library/importlib importlib machinery SourceFileLoader load_module15104422
Ref: f2615104422
Ref: library/importlib importlib machinery SourcelessFileLoader15104774
Ref: 127715104774
Ref: library/importlib importlib machinery SourcelessFileLoader name15105249
Ref: 4af915105249
Ref: library/importlib importlib machinery SourcelessFileLoader path15105333
Ref: 4afa15105333
Ref: library/importlib importlib machinery SourcelessFileLoader is_package15105401
Ref: 4afb15105401
Ref: library/importlib importlib machinery SourcelessFileLoader get_code15105527
Ref: 4afc15105527
Ref: library/importlib importlib machinery SourcelessFileLoader get_source15105663
Ref: 4afd15105663
Ref: library/importlib importlib machinery SourcelessFileLoader load_module15105802
Ref: f2715105802
Ref: library/importlib importlib machinery ExtensionFileLoader15106129
Ref: eb015106129
Ref: library/importlib importlib machinery ExtensionFileLoader name15106808
Ref: 4afe15106808
Ref: library/importlib importlib machinery ExtensionFileLoader path15106885
Ref: 4aff15106885
Ref: library/importlib importlib machinery ExtensionFileLoader create_module15106952
Ref: 4b0015106952
Ref: library/importlib importlib machinery ExtensionFileLoader exec_module15107131
Ref: 4b0115107131
Ref: library/importlib importlib machinery ExtensionFileLoader is_package15107291
Ref: 4b0215107291
Ref: library/importlib importlib machinery ExtensionFileLoader get_code15107474
Ref: 4b0315107474
Ref: library/importlib importlib machinery ExtensionFileLoader get_source15107583
Ref: 4b0415107583
Ref: library/importlib importlib machinery ExtensionFileLoader get_filename15107699
Ref: 115b15107699
Ref: library/importlib importlib machinery NamespaceLoader15107811
Ref: 115815107811
Ref: library/importlib importlib machinery ModuleSpec15108475
Ref: 225515108475
Ref: library/importlib importlib machinery ModuleSpec name15109277
Ref: 234c15109277
Ref: library/importlib importlib machinery ModuleSpec loader15109487
Ref: 33c15109487
Ref: library/importlib importlib machinery ModuleSpec origin15109690
Ref: 4b0515109690
Ref: library/importlib importlib machinery ModuleSpec submodule_search_locations15110192
Ref: 234f15110192
Ref: library/importlib importlib machinery ModuleSpec loader_state15110842
Ref: 4b0615110842
Ref: library/importlib importlib machinery ModuleSpec cached15111086
Ref: 32215111086
Ref: library/importlib importlib machinery ModuleSpec parent15111384
Ref: 32415111384
Ref: library/importlib importlib machinery ModuleSpec has_location15111675
Ref: 4b0715111675
Ref: library/importlib importlib machinery AppleFrameworkLoader15111962
Ref: 225415111962
Ref: library/importlib importlib machinery AppleFrameworkLoader name15115262
Ref: 4b0815115262
Ref: library/importlib importlib machinery AppleFrameworkLoader path15115339
Ref: 4b0915115339
Ref: importlib machinery – Importers and path hooks-Footnote-115115468
Ref: importlib machinery – Importers and path hooks-Footnote-215115548
Ref: importlib machinery – Importers and path hooks-Footnote-315115590
Ref: importlib machinery – Importers and path hooks-Footnote-415115632
Ref: importlib machinery – Importers and path hooks-Footnote-515115674
Node: importlib util – Utility code for importers15115716
Ref: library/importlib importlib-util-utility-code-for-importers15115918
Ref: 4b0a15115918
Ref: library/importlib module-importlib util15115918
Ref: 8115115918
Ref: library/importlib importlib util MAGIC_NUMBER15116244
Ref: 73815116244
Ref: library/importlib importlib util cache_from_source15116484
Ref: 35315116484
Ref: library/importlib importlib util source_from_cache15118405
Ref: 73f15118405
Ref: library/importlib importlib util decode_source15119037
Ref: 115915119037
Ref: library/importlib importlib util resolve_name15119310
Ref: b0815119310
Ref: library/importlib importlib util find_spec15120217
Ref: 5af15120217
Ref: library/importlib importlib util module_from_spec15121117
Ref: 101515121117
Ref: library/importlib importlib util spec_from_loader15121753
Ref: a6f15121753
Ref: library/importlib importlib util spec_from_file_location15122208
Ref: eb115122208
Ref: library/importlib importlib util source_hash15122696
Ref: d4015122696
Ref: library/importlib importlib util _incompatible_extension_module_restrictions15122969
Ref: 4b0b15122969
Ref: library/importlib importlib util LazyLoader15124093
Ref: ead15124093
Ref: library/importlib importlib util LazyLoader factory15125583
Ref: 4b0c15125583
Ref: importlib util – Utility code for importers-Footnote-115126146
Ref: importlib util – Utility code for importers-Footnote-215126220
Ref: importlib util – Utility code for importers-Footnote-315126262
Ref: importlib util – Utility code for importers-Footnote-415126304
Ref: importlib util – Utility code for importers-Footnote-515126346
Ref: importlib util – Utility code for importers-Footnote-615126388
Ref: importlib util – Utility code for importers-Footnote-715126430
Node: Examples<35>15126472
Ref: library/importlib examples15126617
Ref: 4b0d15126617
Ref: library/importlib importlib-examples15126617
Ref: 4b0e15126617
Node: Importing programmatically15126912
Ref: library/importlib importing-programmatically15127032
Ref: 4b0f15127032
Node: Checking if a module can be imported15127263
Ref: library/importlib checking-if-a-module-can-be-imported15127424
Ref: 4b1015127424
Node: Importing a source file directly15128337
Ref: library/importlib importing-a-source-file-directly15128497
Ref: 4b1115128497
Node: Implementing lazy imports15129665
Ref: library/importlib implementing-lazy-imports15129811
Ref: 4b1215129811
Node: Setting up an importer15130530
Ref: library/importlib setting-up-an-importer15130681
Ref: 4b1315130681
Node: Approximating importlib import_module15132258
Ref: library/importlib approximating-importlib-import-module15132375
Ref: 4b1415132375
Node: importlib resources – Package resource reading opening and access15133875
Ref: library/importlib resources doc15134119
Ref: 4b1515134119
Ref: library/importlib resources importlib-resources-package-resource-reading-opening-and-access15134119
Ref: 4b1615134119
Ref: library/importlib resources module-importlib resources15134119
Ref: 7f15134119
Ref: library/importlib resources translation-repo15134119
Ref: 4b1715134119
Ref: library/importlib resources importlib resources Anchor15136153
Ref: 4b1815136153
Ref: library/importlib resources importlib resources files15136353
Ref: 6b715136353
Ref: library/importlib resources importlib resources as_file15137399
Ref: 6b615137399
Ref: importlib resources – Package resource reading opening and access-Footnote-115138243
Ref: importlib resources – Package resource reading opening and access-Footnote-215138332
Ref: importlib resources – Package resource reading opening and access-Footnote-315138403
Ref: importlib resources – Package resource reading opening and access-Footnote-415138497
Ref: importlib resources – Package resource reading opening and access-Footnote-515138569
Node: Functional API15138646
Ref: library/importlib resources functional-api15138764
Ref: 4b1915138764
Ref: library/importlib resources importlib-resources-functional15138764
Ref: 4b1a15138764
Ref: library/importlib resources importlib resources open_binary15140006
Ref: 4ff15140006
Ref: library/importlib resources importlib resources open_text15140495
Ref: 50015140495
Ref: library/importlib resources importlib resources read_binary15141444
Ref: 50215141444
Ref: library/importlib resources importlib resources read_text15141861
Ref: 50315141861
Ref: library/importlib resources importlib resources path15142735
Ref: 50115142735
Ref: library/importlib resources importlib resources is_resource15143728
Ref: 4fe15143728
Ref: library/importlib resources importlib resources contents15144202
Ref: 50415144202
Node: importlib resources abc – Abstract base classes for resources15144905
Ref: library/importlib resources abc doc15145156
Ref: 4b1b15145156
Ref: library/importlib resources abc importlib-resources-abc-abstract-base-classes-for-resources15145156
Ref: 4b1c15145156
Ref: library/importlib resources abc module-importlib resources abc15145156
Ref: 8015145156
Ref: library/importlib resources abc translation-repo15145156
Ref: 4b1d15145156
Ref: library/importlib resources abc importlib resources abc ResourceReader15145447
Ref: 4ae115145447
Ref: library/importlib resources abc importlib resources abc ResourceReader open_resource15147244
Ref: 4b1e15147244
Ref: library/importlib resources abc importlib resources abc ResourceReader resource_path15147505
Ref: 4b1f15147505
Ref: library/importlib resources abc importlib resources abc ResourceReader is_resource15147741
Ref: 4b2015147741
Ref: library/importlib resources abc importlib resources abc ResourceReader contents15148049
Ref: 4b2115148049
Ref: library/importlib resources abc importlib resources abc Traversable15148918
Ref: 2fa15148918
Ref: library/importlib resources abc importlib resources abc Traversable name15149205
Ref: 4b2215149205
Ref: library/importlib resources abc importlib resources abc Traversable iterdir15149323
Ref: 4b2315149323
Ref: library/importlib resources abc importlib resources abc Traversable is_dir15149413
Ref: 4b2415149413
Ref: library/importlib resources abc importlib resources abc Traversable is_file15149509
Ref: 4b2515149509
Ref: library/importlib resources abc importlib resources abc Traversable joinpath15149601
Ref: 4b2615149601
Ref: library/importlib resources abc importlib resources abc Traversable __truediv__15150720
Ref: 4b2715150720
Ref: library/importlib resources abc importlib resources abc Traversable open15150866
Ref: 4b2815150866
Ref: library/importlib resources abc importlib resources abc Traversable read_bytes15151230
Ref: 4b2915151230
Ref: library/importlib resources abc importlib resources abc Traversable read_text15151305
Ref: 4b2a15151305
Ref: library/importlib resources abc importlib resources abc TraversableResources15151391
Ref: 2f915151391
Ref: library/importlib resources abc importlib resources abc TraversableResources files15151916
Ref: 4b2b15151916
Ref: importlib resources abc – Abstract base classes for resources-Footnote-115152104
Node: importlib metadata – Accessing package metadata15152188
Ref: library/importlib metadata doc15152425
Ref: 4b2c15152425
Ref: library/importlib metadata importlib-metadata-accessing-package-metadata15152425
Ref: 4b2d15152425
Ref: library/importlib metadata module-importlib metadata15152425
Ref: 7e15152425
Ref: library/importlib metadata translation-repo15152425
Ref: 4b2e15152425
Ref: library/importlib metadata using15152425
Ref: 4b2f15152425
Ref: importlib metadata – Accessing package metadata-Footnote-115154731
Ref: importlib metadata – Accessing package metadata-Footnote-215154819
Ref: importlib metadata – Accessing package metadata-Footnote-315154903
Ref: importlib metadata – Accessing package metadata-Footnote-415154981
Ref: importlib metadata – Accessing package metadata-Footnote-515155066
Ref: importlib metadata – Accessing package metadata-Footnote-615155151
Ref: importlib metadata – Accessing package metadata-Footnote-715155189
Ref: importlib metadata – Accessing package metadata-Footnote-815155281
Ref: importlib metadata – Accessing package metadata-Footnote-915155350
Node: Overview<3>15155426
Ref: library/importlib metadata overview15155549
Ref: 4b3015155549
Ref: library/importlib metadata importlib metadata PackageNotFoundError15157068
Ref: 4b3515157068
Ref: Overview<3>-Footnote-115157361
Node: Functional API<2>15157445
Ref: library/importlib metadata functional-api15157590
Ref: 4b3615157590
Node: Entry points15157886
Ref: library/importlib metadata entry-points15157982
Ref: 58915157982
Ref: library/importlib metadata id215157982
Ref: 4b3715157982
Ref: library/importlib metadata importlib metadata entry_points15158027
Ref: 4b3815158027
Ref: library/importlib metadata importlib metadata EntryPoints15158599
Ref: 4b3915158599
Ref: library/importlib metadata importlib metadata EntryPoint15158880
Ref: 4b3a15158880
Ref: Entry points-Footnote-115161663
Ref: Entry points-Footnote-215161735
Node: Distribution metadata15161803
Ref: library/importlib metadata distribution-metadata15161929
Ref: 4b3b15161929
Ref: library/importlib metadata metadata15161929
Ref: 4b3115161929
Ref: library/importlib metadata importlib metadata metadata15161992
Ref: 4b3c15161992
Ref: library/importlib metadata importlib metadata PackageMetadata15162329
Ref: 4b3d15162329
Ref: Distribution metadata-Footnote-115163604
Ref: Distribution metadata-Footnote-215163709
Ref: Distribution metadata-Footnote-315163793
Ref: Distribution metadata-Footnote-415163835
Node: Distribution versions15163927
Ref: library/importlib metadata distribution-versions15164059
Ref: 4b3e15164059
Ref: library/importlib metadata version15164059
Ref: 4b3215164059
Ref: library/importlib metadata importlib metadata version15164122
Ref: 194e15164122
Ref: Distribution versions-Footnote-115164615
Ref: Distribution versions-Footnote-215164701
Node: Distribution files15164785
Ref: library/importlib metadata distribution-files15164921
Ref: 4b3f15164921
Ref: library/importlib metadata files15164921
Ref: 4b3315164921
Ref: library/importlib metadata importlib metadata files15164978
Ref: 4b4015164978
Ref: library/importlib metadata importlib metadata PackagePath15165447
Ref: 4b4115165447
Ref: Distribution files-Footnote-115167034
Ref: Distribution files-Footnote-215167118
Node: Distribution requirements15167215
Ref: library/importlib metadata distribution-requirements15167369
Ref: 4b4215167369
Ref: library/importlib metadata requirements15167369
Ref: 4b3415167369
Ref: library/importlib metadata importlib metadata requires15167440
Ref: 4b4315167440
Ref: library/importlib metadata package-distributions15167936
Ref: a1315167936
Ref: Distribution requirements-Footnote-115167973
Node: Mapping import to distribution packages15168057
Ref: library/importlib metadata import-distribution-package-mapping15168184
Ref: 4b4415168184
Ref: library/importlib metadata mapping-import-to-distribution-packages15168184
Ref: 4b4515168184
Ref: library/importlib metadata importlib metadata packages_distributions15168283
Ref: 4b4615168283
Ref: Mapping import to distribution packages-Footnote-115169318
Ref: Mapping import to distribution packages-Footnote-215169402
Ref: Mapping import to distribution packages-Footnote-315169480
Node: Distributions15169542
Ref: library/importlib metadata distributions15169698
Ref: a1415169698
Ref: library/importlib metadata id915169698
Ref: 4b4715169698
Ref: library/importlib metadata importlib metadata distribution15169745
Ref: 4b4815169745
Ref: library/importlib metadata importlib metadata Distribution15170048
Ref: 4b4915170048
Ref: Distributions-Footnote-115171670
Ref: Distributions-Footnote-215171754
Ref: Distributions-Footnote-315171796
Node: Distribution Discovery15171888
Ref: library/importlib metadata distribution-discovery15172056
Ref: 4b4a15172056
Ref: Distribution Discovery-Footnote-115172722
Node: Implementing Custom Providers15172806
Ref: library/importlib metadata implementing-custom-providers15172952
Ref: 4b4b15172952
Ref: Implementing Custom Providers-Footnote-115175146
Node: Example<14>15175230
Ref: library/importlib metadata example15175307
Ref: 4b4c15175307
Node: The initialization of the sys path module search path15178586
Ref: library/sys_path_init doc15178751
Ref: 4b4d15178751
Ref: library/sys_path_init sys-path-init15178751
Ref: 18c415178751
Ref: library/sys_path_init the-initialization-of-the-sys-path-module-search-path15178751
Ref: 4b4e15178751
Ref: library/sys_path_init translation-repo15178751
Ref: 4b4f15178751
Node: Virtual Environments15182934
Ref: library/sys_path_init sys-path-init-virtual-environments15183063
Ref: 489b15183063
Ref: library/sys_path_init virtual-environments15183063
Ref: 4b5015183063
Node: _pth files15184138
Ref: library/sys_path_init pth-files15184291
Ref: 4b5115184291
Node: Embedded Python15185445
Ref: library/sys_path_init embedded-python15185569
Ref: 4b5215185569
Node: Python Language Services15186016
Ref: library/language doc15186167
Ref: 4b5315186167
Ref: library/language language15186167
Ref: 4b5415186167
Ref: library/language python-language-services15186167
Ref: 4b5515186167
Ref: library/language translation-repo15186167
Ref: 4b5615186167
Node: ast — Abstract syntax trees15186979
Ref: library/ast doc15187131
Ref: 4b5715187131
Ref: library/ast ast-abstract-syntax-trees15187131
Ref: 4b5815187131
Ref: library/ast module-ast15187131
Ref: 915187131
Ref: ast — Abstract syntax trees-Footnote-115188165
Node: Abstract grammar15188228
Ref: library/ast abstract-grammar15188331
Ref: 4b5a15188331
Ref: library/ast id115188331
Ref: 4b5b15188331
Node: Node classes15195878
Ref: library/ast node-classes15196001
Ref: 4b5c15196001
Ref: library/ast ast AST15196046
Ref: 4c415196046
Ref: library/ast ast AST _fields15196875
Ref: 17bf15196875
Ref: library/ast ast AST _field_types15197677
Ref: 4c515197677
Ref: library/ast ast AST lineno15198069
Ref: 4b5d15198069
Ref: library/ast ast AST col_offset15198096
Ref: 4b5e15198096
Ref: library/ast ast AST end_lineno15198127
Ref: 4b5f15198127
Ref: library/ast ast AST end_col_offset15198158
Ref: 4b6015198158
Ref: Node classes-Footnote-115202038
Node: Root nodes15202096
Ref: library/ast ast-root-nodes15202175
Ref: 4b6115202175
Ref: library/ast root-nodes15202175
Ref: 4b6215202175
Ref: library/ast ast Module15202216
Ref: 4b6315202216
Ref: library/ast ast Expression15202895
Ref: 4b6515202895
Ref: library/ast ast Interactive15203274
Ref: 186115203274
Ref: library/ast ast FunctionType15204006
Ref: 4b6715204006
Ref: Root nodes-Footnote-115205053
Node: Literals<3>15205095
Ref: library/ast literals15205192
Ref: 4b6815205192
Ref: library/ast ast Constant15205229
Ref: 2ef15205229
Ref: library/ast ast FormattedValue15205754
Ref: 4a7f15205754
Ref: library/ast ast JoinedStr15206700
Ref: 1a4415206700
Ref: library/ast ast TemplateStr15207676
Ref: 4b6915207676
Ref: library/ast ast Interpolation15208728
Ref: 179d15208728
Ref: library/ast ast List15210172
Ref: 4a7c15210172
Ref: library/ast ast Tuple15210205
Ref: 4a7d15210205
Ref: library/ast ast Set15211086
Ref: 4a6c15211086
Ref: library/ast ast Dict15211475
Ref: 1d3115211475
Node: Variables15212299
Ref: library/ast variables15212400
Ref: 4b6b15212400
Ref: library/ast ast Name15212439
Ref: 1d0a15212439
Ref: library/ast ast Load15212582
Ref: 4c315212582
Ref: library/ast ast Store15212603
Ref: 4b6a15212603
Ref: library/ast ast Del15212625
Ref: 4b6c15212625
Ref: library/ast ast Starred15213491
Ref: 4a7b15213491
Node: Expressions<2>15214291
Ref: library/ast ast-expressions15214391
Ref: 4b6615214391
Ref: library/ast expressions15214391
Ref: 4b6d15214391
Ref: library/ast ast Expr15214434
Ref: 4b6e15214434
Ref: library/ast ast UnaryOp15215078
Ref: 4a6715215078
Ref: library/ast ast UAdd15215213
Ref: 4a6915215213
Ref: library/ast ast USub15215234
Ref: 4a6a15215234
Ref: library/ast ast Not15215255
Ref: 4a6b15215255
Ref: library/ast ast Invert15215275
Ref: 4a6815215275
Ref: library/ast ast BinOp15215627
Ref: 1d9a15215627
Ref: library/ast ast Add15216061
Ref: 4b6f15216061
Ref: library/ast ast Sub15216081
Ref: 4b7015216081
Ref: library/ast ast Mult15216101
Ref: 4b7115216101
Ref: library/ast ast Div15216122
Ref: 4b7215216122
Ref: library/ast ast FloorDiv15216142
Ref: 4b7315216142
Ref: library/ast ast Mod15216167
Ref: 4b7415216167
Ref: library/ast ast Pow15216187
Ref: 4b7515216187
Ref: library/ast ast LShift15216207
Ref: 4b7615216207
Ref: library/ast ast RShift15216230
Ref: 4b7715216230
Ref: library/ast ast BitOr15216253
Ref: 4b7815216253
Ref: library/ast ast BitXor15216275
Ref: 4b7915216275
Ref: library/ast ast BitAnd15216298
Ref: 4b7a15216298
Ref: library/ast ast MatMult15216321
Ref: 4b7b15216321
Ref: library/ast ast BoolOp15216376
Ref: 4a8015216376
Ref: library/ast ast And15217038
Ref: 4b7d15217038
Ref: library/ast ast Or15217058
Ref: 4b7c15217058
Ref: library/ast ast Compare15217109
Ref: 4a6d15217109
Ref: library/ast ast Eq15217756
Ref: 4a6e15217756
Ref: library/ast ast NotEq15217775
Ref: 4a6f15217775
Ref: library/ast ast Lt15217797
Ref: 4a7015217797
Ref: library/ast ast LtE15217816
Ref: 4a7115217816
Ref: library/ast ast Gt15217836
Ref: 4a7215217836
Ref: library/ast ast GtE15217855
Ref: 4a7315217855
Ref: library/ast ast Is15217875
Ref: 4a7415217875
Ref: library/ast ast IsNot15217894
Ref: 4a7515217894
Ref: library/ast ast In15217916
Ref: 4a7615217916
Ref: library/ast ast NotIn15217935
Ref: 4a7715217935
Ref: library/ast ast Call15217992
Ref: 4a7815217992
Ref: library/ast ast keyword15219120
Ref: 4b7e15219120
Ref: library/ast ast IfExp15219317
Ref: 4a8115219317
Ref: library/ast ast Attribute15219801
Ref: 4a7915219801
Ref: library/ast ast NamedExpr15220391
Ref: 4a8715220391
Node: Subscripting15221046
Ref: library/ast subscripting15221132
Ref: 4b8015221132
Ref: library/ast ast Subscript15221177
Ref: 4a7a15221177
Ref: library/ast ast Slice15222076
Ref: 4a7e15222076
Node: Comprehensions15222666
Ref: library/ast comprehensions15222752
Ref: 4b8115222752
Ref: library/ast ast ListComp15222801
Ref: 4a8315222801
Ref: library/ast ast SetComp15222844
Ref: 4a8415222844
Ref: library/ast ast GeneratorExp15222886
Ref: 4a8615222886
Ref: library/ast ast DictComp15222933
Ref: 4a8515222933
Ref: library/ast ast comprehension15224858
Ref: 4b8215224858
Node: Statements15227901
Ref: library/ast ast-statements15228004
Ref: 4b6415228004
Ref: library/ast statements15228004
Ref: 4b8315228004
Ref: library/ast ast Assign15228045
Ref: 4b7f15228045
Ref: library/ast ast Assign type_comment15228389
Ref: 4b8415228389
Ref: library/ast ast AnnAssign15229330
Ref: 4b8515229330
Ref: library/ast ast AugAssign15231600
Ref: 4b8615231600
Ref: library/ast ast Raise15232326
Ref: 4b8715232326
Ref: library/ast ast Assert15232864
Ref: 4b8815232864
Ref: library/ast ast Delete15233271
Ref: 4b8915233271
Ref: library/ast ast Pass15233790
Ref: 4b8a15233790
Ref: library/ast ast TypeAlias15233968
Ref: 1a3d15233968
Node: Imports15234672
Ref: library/ast imports15234726
Ref: 4b8c15234726
Ref: library/ast ast Import15234763
Ref: 4b8d15234763
Ref: library/ast ast ImportFrom15235174
Ref: 4b8e15235174
Ref: library/ast ast alias15235888
Ref: 1c5c15235888
Node: Control flow15236408
Ref: library/ast control-flow15236513
Ref: 4b8f15236513
Ref: library/ast ast If15236667
Ref: 4b9015236667
Ref: library/ast ast For15237925
Ref: 4b9115237925
Ref: library/ast ast For type_comment15238464
Ref: 4b9215238464
Ref: library/ast ast While15239189
Ref: 4b9315239189
Ref: library/ast ast Break15239865
Ref: 4b9415239865
Ref: library/ast ast Continue15239887
Ref: 4b9515239887
Ref: library/ast ast Try15240895
Ref: 4b9615240895
Ref: library/ast ast TryStar15242473
Ref: 4b9815242473
Ref: library/ast ast ExceptHandler15243480
Ref: 4b9715243480
Ref: library/ast ast With15244615
Ref: 4b9915244615
Ref: library/ast ast With type_comment15244847
Ref: 4b9b15244847
Ref: library/ast ast withitem15244982
Ref: 4b9a15244982
Node: Pattern matching15246273
Ref: library/ast pattern-matching15246384
Ref: 4b9c15246384
Ref: library/ast ast Match15246439
Ref: 4b9d15246439
Ref: library/ast ast match_case15246749
Ref: 4b9e15246749
Ref: library/ast ast MatchValue15248713
Ref: 4b9f15248713
Ref: library/ast ast MatchSingleton15249684
Ref: 4ba015249684
Ref: library/ast ast MatchSequence15250541
Ref: 4ba115250541
Ref: library/ast ast MatchStar15251733
Ref: 4ba215251733
Ref: library/ast ast MatchMapping15253343
Ref: 4ba315253343
Ref: library/ast ast MatchClass15255310
Ref: 4ba415255310
Ref: library/ast ast MatchAs15258246
Ref: 4ba515258246
Ref: library/ast ast MatchOr15259863
Ref: 4ba615259863
Node: Type annotations15261109
Ref: library/ast type-annotations15261223
Ref: 4ba715261223
Ref: library/ast ast TypeIgnore15261278
Ref: 1af615261278
Node: Type parameters15262525
Ref: library/ast ast-type-params15262653
Ref: 4b8b15262653
Ref: library/ast type-parameters15262653
Ref: 4ba815262653
Ref: library/ast ast TypeVar15262786
Ref: 4ba915262786
Ref: library/ast ast ParamSpec15263983
Ref: 4baa15263983
Ref: library/ast ast TypeVarTuple15265363
Ref: 4bab15265363
Node: Function and class definitions15266575
Ref: library/ast function-and-class-definitions15266702
Ref: 4bac15266702
Ref: library/ast ast FunctionDef15266785
Ref: 1a6015266785
Ref: library/ast ast FunctionDef type_comment15267395
Ref: 4bae15267395
Ref: library/ast ast Lambda15267591
Ref: 4a8215267591
Ref: library/ast ast arguments15268201
Ref: 4bad15268201
Ref: library/ast ast arg15268949
Ref: 4baf15268949
Ref: library/ast ast arg type_comment15269166
Ref: 4bb015269166
Ref: library/ast ast Return15270734
Ref: 4bb115270734
Ref: library/ast ast Yield15270976
Ref: 4a8915270976
Ref: library/ast ast YieldFrom15271006
Ref: 4a8a15271006
Ref: library/ast ast Global15271674
Ref: 4bb215271674
Ref: library/ast ast Nonlocal15271705
Ref: 4bb315271705
Ref: library/ast ast ClassDef15272355
Ref: 1a5e15272355
Ref: Function and class definitions-Footnote-115274036
Node: Async and await15274078
Ref: library/ast async-and-await15274181
Ref: 4bb415274181
Ref: library/ast ast AsyncFunctionDef15274234
Ref: 1a5f15274234
Ref: library/ast ast Await15274510
Ref: 4a8815274510
Ref: library/ast ast AsyncFor15275127
Ref: 4bb515275127
Ref: library/ast ast AsyncWith15275195
Ref: 4bb615275195
Node: ast helpers15275838
Ref: library/ast ast-helpers15275962
Ref: 4bb715275962
Ref: library/ast ast parse15276152
Ref: 1c215276152
Ref: library/ast ast unparse15279270
Ref: ae415279270
Ref: library/ast ast literal_eval15279902
Ref: e1415279902
Ref: library/ast ast get_docstring15281720
Ref: 1e2315281720
Ref: library/ast ast get_source_segment15282186
Ref: bcd15282186
Ref: library/ast ast fix_missing_locations15282668
Ref: 4bb915282668
Ref: library/ast ast increment_lineno15283143
Ref: 1af515283143
Ref: library/ast ast copy_location15283373
Ref: 4bba15283373
Ref: library/ast ast iter_fields15283632
Ref: 4bbb15283632
Ref: library/ast ast iter_child_nodes15283787
Ref: 4bbc15283787
Ref: library/ast ast walk15283965
Ref: 4bbd15283965
Ref: library/ast ast NodeVisitor15284231
Ref: 2f015284231
Ref: library/ast ast NodeVisitor visit15284574
Ref: 4bbe15284574
Ref: library/ast ast NodeVisitor generic_visit15284852
Ref: 4bbf15284852
Ref: library/ast ast NodeVisitor visit_Constant15285173
Ref: c6515285173
Ref: library/ast ast NodeTransformer15285778
Ref: 4bc015285778
Ref: library/ast ast dump15287651
Ref: ae315287651
Ref: ast helpers-Footnote-115289968
Ref: ast helpers-Footnote-215290010
Ref: ast helpers-Footnote-315290052
Node: Compiler flags<2>15290094
Ref: library/ast ast-compiler-flags15290227
Ref: 25a315290227
Ref: library/ast compiler-flags15290227
Ref: 4bc115290227
Ref: library/ast ast PyCF_ALLOW_TOP_LEVEL_AWAIT15290398
Ref: 4bc215290398
Ref: library/ast ast PyCF_ONLY_AST15290582
Ref: 4b5915290582
Ref: library/ast ast PyCF_OPTIMIZED_AST15290713
Ref: 4bc315290713
Ref: library/ast ast PyCF_TYPE_COMMENTS15290906
Ref: 4bb815290906
Ref: library/ast ast compare15291099
Ref: 1bf15291099
Ref: Compiler flags<2>-Footnote-115291668
Ref: Compiler flags<2>-Footnote-215291710
Node: Command-line usage<7>15291752
Ref: library/ast ast-cli15291865
Ref: 4bc415291865
Ref: library/ast command-line-usage15291865
Ref: 4bc515291865
Ref: library/ast cmdoption-ast-h15292128
Ref: 4bc615292128
Ref: library/ast cmdoption-ast-help15292128
Ref: 4bc715292128
Ref: library/ast cmdoption-ast-m15292190
Ref: 4bc815292190
Ref: library/ast cmdoption-ast-mode15292212
Ref: 4bc915292212
Ref: library/ast cmdoption-ast-no-type-comments15292342
Ref: 4bca15292342
Ref: library/ast cmdoption-ast-a15292409
Ref: 4bcb15292409
Ref: library/ast cmdoption-ast-include-attributes15292409
Ref: 4bcc15292409
Ref: library/ast cmdoption-ast-i15292513
Ref: 4bcd15292513
Ref: library/ast cmdoption-ast-indent15292537
Ref: 4bce15292537
Ref: library/ast cmdoption-ast-feature-version15292622
Ref: 1c315292622
Ref: library/ast cmdoption-ast-O15292810
Ref: 4bcf15292810
Ref: library/ast cmdoption-ast-optimize15292833
Ref: 1c415292833
Ref: library/ast cmdoption-ast-show-empty15292961
Ref: 1c515292961
Ref: Command-line usage<7>-Footnote-115294138
Ref: Command-line usage<7>-Footnote-215294186
Ref: Command-line usage<7>-Footnote-315294253
Ref: Command-line usage<7>-Footnote-415294327
Ref: Command-line usage<7>-Footnote-515294366
Node: symtable — Access to the compiler’s symbol tables15294403
Ref: library/symtable doc15294612
Ref: 4bd015294612
Ref: library/symtable module-symtable15294612
Ref: de15294612
Ref: library/symtable symtable-access-to-the-compiler-s-symbol-tables15294612
Ref: 4bd115294612
Ref: library/symtable translation-repo15294612
Ref: 4bd215294612
Ref: symtable — Access to the compiler’s symbol tables-Footnote-115295239
Node: Generating Symbol Tables15295307
Ref: library/symtable generating-symbol-tables15295453
Ref: 4bd315295453
Ref: library/symtable symtable symtable15295522
Ref: 1db915295522
Node: Examining Symbol Tables15295802
Ref: library/symtable examining-symbol-tables15295978
Ref: 4bd515295978
Ref: library/symtable symtable SymbolTableType15296045
Ref: 193a15296045
Ref: library/symtable symtable SymbolTableType MODULE15296167
Ref: 4bd615296167
Ref: library/symtable symtable SymbolTableType FUNCTION15296256
Ref: 4bd715296256
Ref: library/symtable symtable SymbolTableType CLASS15296351
Ref: 4bd815296351
Ref: library/symtable symtable SymbolTableType ANNOTATION15296530
Ref: 4bd915296530
Ref: library/symtable symtable SymbolTableType TYPE_ALIAS15296674
Ref: 4bda15296674
Ref: library/symtable symtable SymbolTableType TYPE_PARAMETERS15296793
Ref: 4bdb15296793
Ref: library/symtable symtable SymbolTableType TYPE_VARIABLE15296961
Ref: 4bdc15296961
Ref: library/symtable symtable SymbolTable15297330
Ref: 4bd415297330
Ref: library/symtable symtable SymbolTable get_type15297433
Ref: 193b15297433
Ref: library/symtable symtable SymbolTable get_id15298109
Ref: 4bdd15298109
Ref: library/symtable symtable SymbolTable get_name15298181
Ref: 4bde15298181
Ref: library/symtable symtable SymbolTable get_lineno15298827
Ref: 4bdf15298827
Ref: library/symtable symtable SymbolTable is_optimized15298952
Ref: 4be015298952
Ref: library/symtable symtable SymbolTable is_nested15299061
Ref: 4be115299061
Ref: library/symtable symtable SymbolTable has_children15299165
Ref: 4be215299165
Ref: library/symtable symtable SymbolTable get_identifiers15299339
Ref: 4be415299339
Ref: library/symtable symtable SymbolTable lookup15299516
Ref: 4be515299516
Ref: library/symtable symtable SymbolTable get_symbols15299638
Ref: 4be615299638
Ref: library/symtable symtable SymbolTable get_children15299762
Ref: 4be315299762
Ref: library/symtable symtable Function15299850
Ref: 4be715299850
Ref: library/symtable symtable Function get_parameters15299981
Ref: 4be815299981
Ref: library/symtable symtable Function get_locals15300102
Ref: 4be915300102
Ref: library/symtable symtable Function get_globals15300205
Ref: 4bea15300205
Ref: library/symtable symtable Function get_nonlocals15300310
Ref: 4beb15300310
Ref: library/symtable symtable Function get_frees15300449
Ref: 4bec15300449
Ref: library/symtable symtable Class15300592
Ref: 4bed15300592
Ref: library/symtable symtable Class get_methods15300706
Ref: 31d15300706
Ref: library/symtable symtable Symbol15302027
Ref: 28915302027
Ref: library/symtable symtable Symbol get_name15302184
Ref: 4bee15302184
Ref: library/symtable symtable Symbol is_referenced15302253
Ref: 4bef15302253
Ref: library/symtable symtable Symbol is_imported15302353
Ref: 4bf015302353
Ref: library/symtable symtable Symbol is_parameter15302476
Ref: 4bf115302476
Ref: library/symtable symtable Symbol is_type_parameter15302569
Ref: 193c15302569
Ref: library/symtable symtable Symbol is_global15302706
Ref: 4bf215302706
Ref: library/symtable symtable Symbol is_nonlocal15302791
Ref: 1df515302791
Ref: library/symtable symtable Symbol is_declared_global15302880
Ref: 152d15302880
Ref: library/symtable symtable Symbol is_local15303017
Ref: 4bf315303017
Ref: library/symtable symtable Symbol is_annotated15303113
Ref: 4bf415303113
Ref: library/symtable symtable Symbol is_free15303237
Ref: 4bf515303237
Ref: library/symtable symtable Symbol is_free_class15303368
Ref: 28c15303368
Ref: library/symtable symtable Symbol is_assigned15304012
Ref: 4bf615304012
Ref: library/symtable symtable Symbol is_comp_iter15304117
Ref: 28b15304117
Ref: library/symtable symtable Symbol is_comp_cell15304277
Ref: 28a15304277
Ref: library/symtable symtable Symbol is_namespace15304437
Ref: 4bf715304437
Ref: library/symtable symtable Symbol get_namespaces15305079
Ref: 4bf815305079
Ref: library/symtable symtable Symbol get_namespace15305174
Ref: 4bf915305174
Node: Command-Line Usage<3>15305374
Ref: library/symtable command-line-usage15305517
Ref: 4bfa15305517
Ref: library/symtable symtable-cli15305517
Ref: 4bfb15305517
Node: token — Constants used with Python parse trees15305871
Ref: library/token doc15306090
Ref: 4bfc15306090
Ref: library/token module-token15306090
Ref: 10015306090
Ref: library/token token-constants-used-with-python-parse-trees15306090
Ref: 4bfd15306090
Ref: library/token translation-repo15306090
Ref: 4bfe15306090
Ref: library/token token tok_name15307046
Ref: 4c0115307046
Ref: library/token token ISTERMINAL15307264
Ref: 4c0215307264
Ref: library/token token ISNONTERMINAL15307351
Ref: 4c0315307351
Ref: library/token token ISEOF15307445
Ref: 4c0415307445
Ref: library/token token NAME15307576
Ref: 22a215307576
Ref: library/token token NUMBER15307734
Ref: 22a315307734
Ref: library/token token STRING15307822
Ref: 22a415307822
Ref: library/token token OP15308167
Ref: 227315308167
Ref: library/token token COMMENT15308485
Ref: 4c0515308485
Ref: library/token token NEWLINE15308603
Ref: 227d15308603
Ref: library/token token NL15308700
Ref: 4c0615308700
Ref: library/token token INDENT15308931
Ref: 20e615308931
Ref: library/token token DEDENT15309087
Ref: 229b15309087
Ref: library/token token FSTRING_START15309241
Ref: 22da15309241
Ref: library/token token FSTRING_MIDDLE15309528
Ref: 22db15309528
Ref: library/token token FSTRING_END15309974
Ref: 22dc15309974
Ref: library/token token TSTRING_START15310178
Ref: 4c0b15310178
Ref: library/token token TSTRING_MIDDLE15310489
Ref: 4c0c15310489
Ref: library/token token TSTRING_END15310958
Ref: 4c0d15310958
Ref: library/token token ENDMARKER15311195
Ref: 229f15311195
Ref: library/token token ENCODING15311324
Ref: 4c0e15311324
Ref: library/token token TYPE_IGNORE15311853
Ref: 4c0f15311853
Ref: library/token token TYPE_COMMENT15312101
Ref: 4c1015312101
Ref: library/token token SOFT_KEYWORD15312331
Ref: 4c0015312331
Ref: library/token token ERRORTOKEN15312586
Ref: 4c1215312586
Ref: library/token token-operators-delimiters15312917
Ref: 230715312917
Ref: library/token token LPAR15313458
Ref: 4c1315313458
Ref: library/token token RPAR15313635
Ref: 4c1415313635
Ref: library/token token LSQB15313812
Ref: 4c1515313812
Ref: library/token token RSQB15313989
Ref: 4c1615313989
Ref: library/token token COLON15314167
Ref: 4c0a15314167
Ref: library/token token COMMA15314344
Ref: 4c1715314344
Ref: library/token token SEMI15314520
Ref: 4c1815314520
Ref: library/token token PLUS15314697
Ref: 4bff15314697
Ref: library/token token MINUS15314875
Ref: 4c1915314875
Ref: library/token token STAR15315051
Ref: 4c1a15315051
Ref: library/token token SLASH15315229
Ref: 4c1b15315229
Ref: library/token token VBAR15315405
Ref: 4c1c15315405
Ref: library/token token AMPER15315583
Ref: 4c1d15315583
Ref: library/token token LESS15315759
Ref: 4c1e15315759
Ref: library/token token GREATER15315939
Ref: 4c1f15315939
Ref: library/token token EQUAL15316114
Ref: 4c2015316114
Ref: library/token token DOT15316289
Ref: 4c2115316289
Ref: library/token token PERCENT15316470
Ref: 4c2215316470
Ref: library/token token LBRACE15316646
Ref: 4c0715316646
Ref: library/token token RBRACE15316823
Ref: 4c0815316823
Ref: library/token token EQEQUAL15317001
Ref: 4c2315317001
Ref: library/token token NOTEQUAL15317180
Ref: 4c2415317180
Ref: library/token token LESSEQUAL15317359
Ref: 4c2515317359
Ref: library/token token GREATEREQUAL15317540
Ref: 4c2615317540
Ref: library/token token TILDE15317711
Ref: 4c2715317711
Ref: library/token token CIRCUMFLEX15317893
Ref: 4c2815317893
Ref: library/token token LEFTSHIFT15318069
Ref: 4c2915318069
Ref: library/token token RIGHTSHIFT15318248
Ref: 4c2a15318248
Ref: library/token token DOUBLESTAR15318426
Ref: 4c2b15318426
Ref: library/token token PLUSEQUAL15318603
Ref: 4c2c15318603
Ref: library/token token MINEQUAL15318780
Ref: 4c2d15318780
Ref: library/token token STAREQUAL15318959
Ref: 4c2e15318959
Ref: library/token token SLASHEQUAL15319138
Ref: 4c2f15319138
Ref: library/token token PERCENTEQUAL15319318
Ref: 4c3015319318
Ref: library/token token AMPEREQUAL15319494
Ref: 4c3115319494
Ref: library/token token VBAREQUAL15319671
Ref: 4c3215319671
Ref: library/token token CIRCUMFLEXEQUAL15319855
Ref: 4c3315319855
Ref: library/token token LEFTSHIFTEQUAL15320032
Ref: 4c3415320032
Ref: library/token token RIGHTSHIFTEQUAL15320212
Ref: 4c3515320212
Ref: library/token token DOUBLESTAREQUAL15320391
Ref: 4c3615320391
Ref: library/token token DOUBLESLASH15320566
Ref: 4c3715320566
Ref: library/token token DOUBLESLASHEQUAL15320749
Ref: 4c3815320749
Ref: library/token token AT15320914
Ref: 4c3915320914
Ref: library/token token ATEQUAL15321096
Ref: 4c3a15321096
Ref: library/token token RARROW15321273
Ref: 4c3b15321273
Ref: library/token token ELLIPSIS15321453
Ref: 4c3c15321453
Ref: library/token token COLONEQUAL15321634
Ref: 4c3d15321634
Ref: library/token token EXCLAMATION15321813
Ref: 4c0915321813
Ref: library/token token N_TOKENS15321957
Ref: 4c3e15321957
Ref: library/token token EXACT_TOKEN_TYPES15322039
Ref: 18cf15322039
Ref: token — Constants used with Python parse trees-Footnote-115322987
Node: keyword — Testing for Python keywords15323052
Ref: library/keyword doc15323258
Ref: 4c3f15323258
Ref: library/keyword keyword-testing-for-python-keywords15323258
Ref: 4c4015323258
Ref: library/keyword module-keyword15323258
Ref: 8815323258
Ref: library/keyword translation-repo15323258
Ref: 4c4115323258
Ref: library/keyword keyword iskeyword15323577
Ref: 263015323577
Ref: library/keyword keyword kwlist15323678
Ref: 4c4215323678
Ref: library/keyword keyword issoftkeyword15323946
Ref: 4c1115323946
Ref: library/keyword keyword softkwlist15324083
Ref: 4c4315324083
Ref: keyword — Testing for Python keywords-Footnote-115324428
Node: tokenize — Tokenizer for Python source15324495
Ref: library/tokenize doc15324700
Ref: 4c4415324700
Ref: library/tokenize module-tokenize15324700
Ref: 10115324700
Ref: library/tokenize tokenize-tokenizer-for-python-source15324700
Ref: 4c4515324700
Ref: library/tokenize translation-repo15324700
Ref: 4c4615324700
Ref: tokenize — Tokenizer for Python source-Footnote-115325985
Node: Tokenizing Input15326053
Ref: library/tokenize tokenizing-input15326176
Ref: 4c4715326176
Ref: library/tokenize tokenize tokenize15326283
Ref: 70115326283
Ref: library/tokenize tokenize generate_tokens15327727
Ref: 70215327727
Ref: library/tokenize tokenize untokenize15328493
Ref: 189b15328493
Ref: library/tokenize tokenize detect_encoding15329374
Ref: 17a015329374
Ref: library/tokenize tokenize open15330370
Ref: 2cc515330370
Ref: library/tokenize tokenize TokenError15330541
Ref: 76515330541
Ref: Tokenizing Input-Footnote-115330857
Ref: Tokenizing Input-Footnote-215330899
Node: Command-Line Usage<4>15330941
Ref: library/tokenize command-line-usage15331085
Ref: 4c4815331085
Ref: library/tokenize tokenize-cli15331085
Ref: 4c4915331085
Ref: library/tokenize cmdoption-tokenize-h15331351
Ref: 4c4a15331351
Ref: library/tokenize cmdoption-tokenize-help15331351
Ref: 4c4b15331351
Ref: library/tokenize cmdoption-tokenize-e15331413
Ref: 4c4c15331413
Ref: library/tokenize cmdoption-tokenize-exact15331413
Ref: 4c4d15331413
Node: Examples<36>15331605
Ref: library/tokenize examples15331724
Ref: 4c4e15331724
Node: tabnanny — Detection of ambiguous indentation15336217
Ref: library/tabnanny doc15336423
Ref: 4c4f15336423
Ref: library/tabnanny module-tabnanny15336423
Ref: e315336423
Ref: library/tabnanny tabnanny-detection-of-ambiguous-indentation15336423
Ref: 4c5015336423
Ref: library/tabnanny translation-repo15336423
Ref: 4c5115336423
Ref: library/tabnanny tabnanny check15336954
Ref: 4c5215336954
Ref: library/tabnanny tabnanny verbose15337395
Ref: 4c5315337395
Ref: library/tabnanny tabnanny filename_only15337552
Ref: 4c5415337552
Ref: library/tabnanny tabnanny NannyNag15337770
Ref: 4c5515337770
Ref: library/tabnanny tabnanny process_tokens15337935
Ref: 4c5615337935
Ref: tabnanny — Detection of ambiguous indentation-Footnote-115338238
Node: pyclbr — Python module browser support15338306
Ref: library/pyclbr doc15338514
Ref: 4c5715338514
Ref: library/pyclbr module-pyclbr15338514
Ref: b915338514
Ref: library/pyclbr pyclbr-python-module-browser-support15338514
Ref: 4c5815338514
Ref: library/pyclbr translation-repo15338514
Ref: 4c5915338514
Ref: library/pyclbr pyclbr readmodule15339212
Ref: a2e15339212
Ref: library/pyclbr pyclbr readmodule_ex15339823
Ref: a2f15339823
Ref: pyclbr — Python module browser support-Footnote-115340884
Node: Function Objects15340950
Ref: library/pyclbr function-objects15341065
Ref: 4c5a15341065
Ref: library/pyclbr pyclbr-function-objects15341065
Ref: 4c5b15341065
Ref: library/pyclbr pyclbr Function15341118
Ref: 4c5c15341118
Ref: library/pyclbr pyclbr Function file15341272
Ref: 4c5d15341272
Ref: library/pyclbr pyclbr Function module15341360
Ref: 4c5e15341360
Ref: library/pyclbr pyclbr Function name15341455
Ref: 4c5f15341455
Ref: library/pyclbr pyclbr Function lineno15341518
Ref: 4c6015341518
Ref: library/pyclbr pyclbr Function parent15341614
Ref: 4c6115341614
Ref: library/pyclbr pyclbr Function children15341768
Ref: 4c6215341768
Ref: library/pyclbr pyclbr Function is_async15341940
Ref: 4c6315341940
Node: Class Objects15342125
Ref: library/pyclbr class-objects15342240
Ref: 4c6415342240
Ref: library/pyclbr pyclbr-class-objects15342240
Ref: 4c6515342240
Ref: library/pyclbr pyclbr Class15342287
Ref: 4c6615342287
Ref: library/pyclbr pyclbr Class file15342474
Ref: 4c6715342474
Ref: library/pyclbr pyclbr Class module15342559
Ref: 4c6815342559
Ref: library/pyclbr pyclbr Class name15342651
Ref: 4c6915342651
Ref: library/pyclbr pyclbr Class lineno15342711
Ref: 4c6a15342711
Ref: library/pyclbr pyclbr Class parent15342807
Ref: 4c6b15342807
Ref: library/pyclbr pyclbr Class children15342957
Ref: 4c6c15342957
Ref: library/pyclbr pyclbr Class super15343117
Ref: 4c6d15343117
Ref: library/pyclbr pyclbr Class methods15343478
Ref: 4c6e15343478
Node: py_compile — Compile Python source files15343706
Ref: library/py_compile doc15343911
Ref: 4c6f15343911
Ref: library/py_compile module-py_compile15343911
Ref: b815343911
Ref: library/py_compile py-compile-compile-python-source-files15343911
Ref: 4c7015343911
Ref: library/py_compile translation-repo15343911
Ref: 4c7115343911
Ref: library/py_compile py_compile PyCompileError15344534
Ref: 4c7215344534
Ref: library/py_compile py_compile compile15344663
Ref: c1c15344663
Ref: library/py_compile py_compile PycInvalidationMode15348440
Ref: 4c7315348440
Ref: library/py_compile py_compile PycInvalidationMode TIMESTAMP15348865
Ref: 4c7515348865
Ref: library/py_compile py_compile PycInvalidationMode CHECKED_HASH15349147
Ref: 4c7415349147
Ref: library/py_compile py_compile PycInvalidationMode UNCHECKED_HASH15349393
Ref: 4c7615349393
Ref: py_compile — Compile Python source files-Footnote-115349941
Ref: py_compile — Compile Python source files-Footnote-215350011
Ref: py_compile — Compile Python source files-Footnote-315350053
Ref: py_compile — Compile Python source files-Footnote-415350095
Ref: py_compile — Compile Python source files-Footnote-515350137
Node: Command-Line Interface<5>15350179
Ref: library/py_compile command-line-interface15350283
Ref: 4c7715350283
Ref: library/py_compile py-compile-cli15350283
Ref: 4c7815350283
Ref: library/py_compile cmdoption-python-m-py_compile-arg-file15350712
Ref: 4c7915350712
Ref: library/py_compile cmdoption-python-m-py_compile15350743
Ref: 4c7a15350743
Ref: library/py_compile cmdoption-python-m-py_compile-q15350895
Ref: 4c7b15350895
Ref: library/py_compile cmdoption-python-m-py_compile-quiet15350895
Ref: 4c7c15350895
Node: compileall — Byte-compile Python libraries15351197
Ref: library/compileall doc15351402
Ref: 4c7d15351402
Ref: library/compileall compileall-byte-compile-python-libraries15351402
Ref: 4c7e15351402
Ref: library/compileall module-compileall15351402
Ref: 2115351402
Ref: library/compileall translation-repo15351402
Ref: 4c7f15351402
Ref: compileall — Byte-compile Python libraries-Footnote-115352223
Node: Command-line use15352293
Ref: library/compileall command-line-use15352415
Ref: 4c8015352415
Ref: library/compileall compileall-cli15352415
Ref: 4c8115352415
Ref: library/compileall cmdoption-compileall-arg-directory15352564
Ref: 4c8215352564
Ref: library/compileall cmdoption-compileall-arg-file15352590
Ref: 4c8315352590
Ref: library/compileall cmdoption-compileall-l15352838
Ref: 4c8415352838
Ref: library/compileall cmdoption-compileall-f15352988
Ref: 4c8515352988
Ref: library/compileall cmdoption-compileall-q15353059
Ref: 4c8615353059
Ref: library/compileall cmdoption-compileall-d15353243
Ref: 4c8715353243
Ref: library/compileall cmdoption-compileall-s15353596
Ref: 4c8815353596
Ref: library/compileall cmdoption-compileall-p15353811
Ref: 4c8915353811
Ref: library/compileall cmdoption-compileall-x15354031
Ref: 4c8a15354031
Ref: library/compileall cmdoption-compileall-i15354204
Ref: 4c8b15354204
Ref: library/compileall cmdoption-compileall-b15354406
Ref: 4c8c15354406
Ref: library/compileall cmdoption-compileall-r15354732
Ref: 4c8d15354732
Ref: library/compileall cmdoption-compileall-j15355002
Ref: 4c8e15355002
Ref: library/compileall cmdoption-compileall-invalidation-mode15355189
Ref: 4c8f15355189
Ref: library/compileall cmdoption-compileall-o15355988
Ref: 4c9015355988
Ref: library/compileall cmdoption-compileall-e15356181
Ref: 4c9115356181
Ref: library/compileall cmdoption-compileall-hardlink-dupes15356261
Ref: 4c9215356261
Ref: Command-line use-Footnote-115357575
Node: Public functions15357617
Ref: library/compileall public-functions15357739
Ref: 4c9315357739
Ref: library/compileall compileall compile_dir15357792
Ref: d1d15357792
Ref: library/compileall compileall compile_file15361984
Ref: fe315361984
Ref: library/compileall compileall compile_path15365008
Ref: fe415365008
Ref: Public functions-Footnote-115366771
Ref: Public functions-Footnote-215366813
Node: dis — Disassembler for Python bytecode15366855
Ref: library/dis doc15367061
Ref: 4c9415367061
Ref: library/dis dis-disassembler-for-python-bytecode15367061
Ref: 4c9515367061
Ref: library/dis module-dis15367061
Ref: 3c15367061
Ref: library/dis translation-repo15367061
Ref: 4c9615367061
Ref: dis — Disassembler for Python bytecode-Footnote-115369992
Node: Command-line interface<12>15370055
Ref: library/dis command-line-interface15370184
Ref: 4c9715370184
Ref: library/dis dis-cli15370184
Ref: 4c9815370184
Ref: library/dis cmdoption-dis-h15370419
Ref: 4c9915370419
Ref: library/dis cmdoption-dis-help15370419
Ref: 4c9a15370419
Ref: library/dis cmdoption-dis-C15370473
Ref: 4c9b15370473
Ref: library/dis cmdoption-dis-show-caches15370473
Ref: 4c9c15370473
Ref: library/dis cmdoption-dis-O15370559
Ref: 4ec15370559
Ref: library/dis cmdoption-dis-show-offsets15370559
Ref: 4c9d15370559
Ref: library/dis cmdoption-dis-P15370656
Ref: 20815370656
Ref: library/dis cmdoption-dis-show-positions15370656
Ref: 4c9e15370656
Ref: library/dis cmdoption-dis-S15370776
Ref: 20915370776
Ref: library/dis cmdoption-dis-specialized15370776
Ref: 4c9f15370776
Node: Bytecode analysis15371031
Ref: library/dis bytecode-analysis15371187
Ref: 4ca015371187
Ref: library/dis dis Bytecode15371429
Ref: 20415371429
Ref: library/dis dis Bytecode from_traceback15373087
Ref: 113215373087
Ref: library/dis dis Bytecode codeobj15373333
Ref: 4ca115373333
Ref: library/dis dis Bytecode first_line15373394
Ref: 4ca215373394
Ref: library/dis dis Bytecode dis15373488
Ref: 113115373488
Ref: library/dis dis Bytecode info15373679
Ref: 4ca315373679
Node: Analysis functions15374390
Ref: library/dis analysis-functions15374548
Ref: 4ca415374548
Ref: library/dis dis code_info15374854
Ref: 144115374854
Ref: library/dis dis show_code15375400
Ref: 113015375400
Ref: library/dis dis dis15375871
Ref: 20515375871
Ref: library/dis dis distb15377968
Ref: 20615377968
Ref: library/dis dis disassemble15378693
Ref: 20715378693
Ref: library/dis dis disco15378851
Ref: 4ca515378851
Ref: library/dis dis get_instructions15380215
Ref: 4ed15380215
Ref: library/dis dis findlinestarts15381359
Ref: 4ca615381359
Ref: library/dis dis findlabels15382080
Ref: 4ca715382080
Ref: library/dis dis stack_effect15382250
Ref: 113315382250
Ref: Analysis functions-Footnote-115383181
Node: Python Bytecode Instructions15383223
Ref: library/dis bytecodes15383382
Ref: 7d015383382
Ref: library/dis python-bytecode-instructions15383382
Ref: 4ca815383382
Ref: library/dis dis Instruction15383616
Ref: 20315383616
Ref: library/dis dis Instruction opcode15383684
Ref: 4ca915383684
Ref: library/dis dis Instruction opname15383877
Ref: 4cab15383877
Ref: library/dis dis Instruction baseopcode15383945
Ref: 4cac15383945
Ref: library/dis dis Instruction baseopname15384097
Ref: 4cad15384097
Ref: library/dis dis Instruction arg15384256
Ref: 4caf15384256
Ref: library/dis dis Instruction oparg15384348
Ref: 4cb015384348
Ref: library/dis dis Instruction argval15384408
Ref: 4cb115384408
Ref: library/dis dis Instruction argrepr15384492
Ref: 4cb215384492
Ref: library/dis dis Instruction offset15384623
Ref: 4cb315384623
Ref: library/dis dis Instruction start_offset15384707
Ref: 4cb415384707
Ref: library/dis dis Instruction cache_offset15384918
Ref: 4cb515384918
Ref: library/dis dis Instruction end_offset15385015
Ref: 4cb615385015
Ref: library/dis dis Instruction starts_line15385108
Ref: 4cb715385108
Ref: library/dis dis Instruction line_number15385217
Ref: 4cb815385217
Ref: library/dis dis Instruction is_jump_target15385344
Ref: 4cb915385344
Ref: library/dis dis Instruction jump_target15385448
Ref: 4cba15385448
Ref: library/dis dis Instruction positions15385581
Ref: 4cbb15385581
Ref: library/dis dis Instruction cache_info15385736
Ref: 4cbc15385736
Ref: library/dis dis Positions15386455
Ref: 192815386455
Ref: library/dis dis Positions lineno15386568
Ref: 4cbd15386568
Ref: library/dis dis Positions end_lineno15386591
Ref: 4cbe15386591
Ref: library/dis dis Positions col_offset15386618
Ref: 4cbf15386618
Ref: library/dis dis Positions end_col_offset15386645
Ref: 4cc015386645
Ref: library/dis opcode-NOP15387009
Ref: 4cc115387009
Ref: library/dis opcode-NOT_TAKEN15387141
Ref: 37615387141
Ref: library/dis opcode-POP_ITER15387351
Ref: 37015387351
Ref: library/dis opcode-POP_TOP15387456
Ref: 4cc215387456
Ref: library/dis opcode-END_FOR15387537
Ref: 4cc315387537
Ref: library/dis opcode-END_SEND15387714
Ref: 4cc415387714
Ref: library/dis opcode-COPY15387850
Ref: 91815387850
Ref: library/dis opcode-SWAP15388061
Ref: 91915388061
Ref: library/dis opcode-CACHE15388222
Ref: 90915388222
Ref: library/dis opcode-UNARY_NEGATIVE15389057
Ref: 4cc515389057
Ref: library/dis opcode-UNARY_NOT15389132
Ref: 1a4915389132
Ref: library/dis opcode-UNARY_INVERT15389311
Ref: 4cc615389311
Ref: library/dis opcode-GET_ITER15389384
Ref: 4cc715389384
Ref: library/dis opcode-GET_YIELD_FROM_ITER15389458
Ref: 4cc815389458
Ref: library/dis opcode-TO_BOOL15389698
Ref: 1a4615389698
Ref: library/dis opcode-BINARY_OP15390215
Ref: 36615390215
Ref: library/dis opcode-STORE_SUBSCR15390590
Ref: 1b9315390590
Ref: library/dis opcode-DELETE_SUBSCR15390760
Ref: 4cc915390760
Ref: library/dis opcode-BINARY_SLICE15390897
Ref: 70615390897
Ref: library/dis opcode-STORE_SLICE15391108
Ref: 70715391108
Ref: library/dis opcode-GET_AWAITABLE15391363
Ref: 1baf15391363
Ref: library/dis opcode-GET_AITER15391994
Ref: 4cca15391994
Ref: library/dis opcode-GET_ANEXT15392216
Ref: 4ccb15392216
Ref: library/dis opcode-END_ASYNC_FOR15392423
Ref: ca215392423
Ref: library/dis opcode-CLEANUP_THROW15392913
Ref: 70a15392913
Ref: library/dis opcode-SET_ADD15393300
Ref: 4ccc15393300
Ref: library/dis opcode-LIST_APPEND15393452
Ref: 4ccd15393452
Ref: library/dis opcode-MAP_ADD15393613
Ref: ca415393613
Ref: library/dis opcode-RETURN_VALUE15394226
Ref: 1b0815394226
Ref: library/dis opcode-YIELD_VALUE15394318
Ref: 5ba15394318
Ref: library/dis opcode-SETUP_ANNOTATIONS15394729
Ref: f5215394729
Ref: library/dis opcode-POP_EXCEPT15395029
Ref: 4cce15395029
Ref: library/dis opcode-RERAISE15395256
Ref: 4ccf15395256
Ref: library/dis opcode-PUSH_EXC_INFO15395619
Ref: 91315395619
Ref: library/dis opcode-CHECK_EXC_MATCH15395859
Ref: 91a15395859
Ref: library/dis opcode-CHECK_EG_MATCH15396121
Ref: 91215396121
Ref: library/dis opcode-WITH_EXCEPT_START15396578
Ref: 4cd015396578
Ref: library/dis opcode-LOAD_COMMON_CONSTANT15397119
Ref: 36a15397119
Ref: library/dis opcode-LOAD_BUILD_CLASS15397408
Ref: 4cd115397408
Ref: library/dis opcode-GET_LEN15397547
Ref: 4cd215397547
Ref: library/dis opcode-MATCH_MAPPING15397744
Ref: 4cd315397744
Ref: library/dis opcode-MATCH_SEQUENCE15398065
Ref: 4cd415398065
Ref: library/dis opcode-MATCH_KEYS15398479
Ref: 92115398479
Ref: library/dis opcode-STORE_NAME15398956
Ref: 4cd515398956
Ref: library/dis opcode-DELETE_NAME15399240
Ref: 4cd715399240
Ref: library/dis opcode-UNPACK_SEQUENCE15399406
Ref: 1bb115399406
Ref: library/dis opcode-UNPACK_EX15399698
Ref: 4cd815399698
Ref: library/dis opcode-STORE_ATTR15400657
Ref: 1bb015400657
Ref: library/dis opcode-DELETE_ATTR15400895
Ref: 4cd915400895
Ref: library/dis opcode-STORE_GLOBAL15401102
Ref: 4cd615401102
Ref: library/dis opcode-DELETE_GLOBAL15401208
Ref: 4cda15401208
Ref: library/dis opcode-LOAD_CONST15401310
Ref: 4cdb15401310
Ref: library/dis opcode-LOAD_SMALL_INT15401396
Ref: 36e15401396
Ref: library/dis opcode-LOAD_NAME15401543
Ref: 4cdc15401543
Ref: library/dis opcode-LOAD_LOCALS15401739
Ref: 70f15401739
Ref: library/dis opcode-LOAD_FROM_DICT_OR_GLOBALS15402004
Ref: 70e15402004
Ref: library/dis opcode-BUILD_TEMPLATE15402397
Ref: 36815402397
Ref: library/dis opcode-BUILD_INTERPOLATION15402756
Ref: 36715402756
Ref: library/dis opcode-BUILD_TUPLE15403769
Ref: 4cdd15403769
Ref: library/dis opcode-BUILD_LIST15404095
Ref: 4cde15404095
Ref: library/dis opcode-BUILD_SET15404187
Ref: 4cdf15404187
Ref: library/dis opcode-BUILD_MAP15404277
Ref: 36915404277
Ref: library/dis opcode-BUILD_STRING15404663
Ref: f4f15404663
Ref: library/dis opcode-LIST_EXTEND15404828
Ref: 4ce015404828
Ref: library/dis opcode-SET_UPDATE15404997
Ref: 4ce115404997
Ref: library/dis opcode-DICT_UPDATE15405163
Ref: 4ce215405163
Ref: library/dis opcode-DICT_MERGE15405332
Ref: 4ce315405332
Ref: library/dis opcode-LOAD_ATTR15405473
Ref: 70515405473
Ref: library/dis opcode-LOAD_SUPER_ATTR15406414
Ref: 70315406414
Ref: library/dis opcode-COMPARE_OP15407485
Ref: b6315407485
Ref: library/dis opcode-IS_OP15407869
Ref: 192415407869
Ref: library/dis opcode-CONTAINS_OP15407999
Ref: 192315407999
Ref: library/dis opcode-IMPORT_NAME15408135
Ref: 4ce415408135
Ref: library/dis opcode-IMPORT_FROM15408555
Ref: 4ce515408555
Ref: library/dis opcode-JUMP_FORWARD15408804
Ref: 195a15408804
Ref: library/dis opcode-JUMP_BACKWARD15408884
Ref: 91b15408884
Ref: library/dis opcode-JUMP_BACKWARD_NO_INTERRUPT15409018
Ref: 90f15409018
Ref: library/dis opcode-POP_JUMP_IF_TRUE15409178
Ref: 1a4715409178
Ref: library/dis opcode-POP_JUMP_IF_FALSE15409740
Ref: 1a4815409740
Ref: library/dis opcode-POP_JUMP_IF_NOT_NONE15410305
Ref: 1b6815410305
Ref: library/dis opcode-POP_JUMP_IF_NONE15410578
Ref: 1b6715410578
Ref: library/dis opcode-FOR_ITER15410843
Ref: 1aaa15410843
Ref: library/dis opcode-LOAD_GLOBAL15411261
Ref: 1a4215411261
Ref: library/dis opcode-LOAD_FAST15411512
Ref: 4ce615411512
Ref: library/dis opcode-LOAD_FAST_BORROW15411826
Ref: 36c15411826
Ref: library/dis opcode-LOAD_FAST_LOAD_FAST15411990
Ref: 4ce715411990
Ref: library/dis opcode-LOAD_FAST_BORROW_LOAD_FAST_BORROW15412181
Ref: 36d15412181
Ref: library/dis opcode-LOAD_FAST_CHECK15412395
Ref: 70c15412395
Ref: library/dis opcode-LOAD_FAST_AND_CLEAR15412644
Ref: 70b15412644
Ref: library/dis opcode-STORE_FAST15412942
Ref: 1a4b15412942
Ref: library/dis opcode-STORE_FAST_STORE_FAST15413050
Ref: 4ce815413050
Ref: library/dis opcode-STORE_FAST_LOAD_FAST15413256
Ref: 4ce915413256
Ref: library/dis opcode-DELETE_FAST15413504
Ref: 4cea15413504
Ref: library/dis opcode-MAKE_CELL15413587
Ref: 91015413587
Ref: library/dis opcode-LOAD_DEREF15413761
Ref: 4ceb15413761
Ref: library/dis opcode-LOAD_FROM_DICT_OR_DEREF15414049
Ref: 70d15414049
Ref: library/dis opcode-STORE_DEREF15414578
Ref: 4cec15414578
Ref: library/dis opcode-DELETE_DEREF15414826
Ref: 4ced15414826
Ref: library/dis opcode-COPY_FREE_VARS15415122
Ref: 90e15415122
Ref: library/dis opcode-RAISE_VARARGS15415370
Ref: 4cee15415370
Ref: library/dis opcode-CALL15415839
Ref: 91615415839
Ref: library/dis opcode-CALL_KW15416620
Ref: 37215416620
Ref: library/dis opcode-CALL_FUNCTION_EX15417452
Ref: f5115417452
Ref: library/dis opcode-PUSH_NULL15418132
Ref: 91715418132
Ref: library/dis opcode-MAKE_FUNCTION15418330
Ref: f5015418330
Ref: library/dis opcode-SET_FUNCTION_ATTRIBUTE15418827
Ref: 4cef15418827
Ref: library/dis opcode-BUILD_SLICE15419749
Ref: 4cf015419749
Ref: library/dis opcode-EXTENDED_ARG15420218
Ref: 1b0615420218
Ref: library/dis opcode-CONVERT_VALUE15420555
Ref: 4cf115420555
Ref: library/dis opcode-FORMAT_SIMPLE15421031
Ref: 4cf215421031
Ref: library/dis opcode-FORMAT_WITH_SPEC15421297
Ref: 4cf315421297
Ref: library/dis opcode-MATCH_CLASS15421614
Ref: 92015421614
Ref: library/dis opcode-RESUME15422341
Ref: 5bb15422341
Ref: library/dis opcode-RETURN_GENERATOR15423084
Ref: 90c15423084
Ref: library/dis opcode-SEND15423378
Ref: 90d15423378
Ref: library/dis opcode-HAVE_ARGUMENT15423745
Ref: 6b215423745
Ref: library/dis opcode-CALL_INTRINSIC_115424616
Ref: 70815424616
Ref: library/dis opcode-CALL_INTRINSIC_215427946
Ref: 70915427946
Ref: library/dis opcode-LOAD_SPECIAL15429812
Ref: 36f15429812
Ref: library/dis opcode-SETUP_FINALLY15430330
Ref: 4cf415430330
Ref: library/dis opcode-SETUP_CLEANUP15430594
Ref: 4cf515430594
Ref: library/dis opcode-SETUP_WITH15430999
Ref: 4cf615430999
Ref: library/dis opcode-POP_BLOCK15431431
Ref: 4cf715431431
Ref: library/dis opcode-LOAD_CONST_IMMORTAL15431584
Ref: 37515431584
Ref: library/dis opcode-JUMP15431714
Ref: 4cf815431714
Ref: library/dis opcode-JUMP_NO_INTERRUPT15431731
Ref: 1b8d15431731
Ref: library/dis opcode-JUMP_IF_TRUE15431898
Ref: 37315431898
Ref: library/dis opcode-JUMP_IF_FALSE15431923
Ref: 37415431923
Ref: library/dis opcode-LOAD_CLOSURE15432095
Ref: 1a4515432095
Node: Opcode collections15432398
Ref: library/dis id115432530
Ref: 4cf915432530
Ref: library/dis opcode-collections15432530
Ref: 4caa15432530
Ref: library/dis dis opname15432889
Ref: 4cae15432889
Ref: library/dis dis opmap15432976
Ref: 4cfa15432976
Ref: library/dis dis cmp_op15433052
Ref: 4cfb15433052
Ref: library/dis dis hasarg15433121
Ref: 59f15433121
Ref: library/dis dis hasconst15433225
Ref: 4cfc15433225
Ref: library/dis dis hasfree15433301
Ref: 4cfd15433301
Ref: library/dis dis hasname15433649
Ref: 4cfe15433649
Ref: library/dis dis hasjump15433734
Ref: 4cff15433734
Ref: library/dis dis haslocal15433869
Ref: 4d0015433869
Ref: library/dis dis hascompare15433951
Ref: 4d0115433951
Ref: library/dis dis hasexc15434028
Ref: 6b315434028
Ref: library/dis dis hasjrel15434138
Ref: 4d0215434138
Ref: library/dis dis hasjabs15434319
Ref: 4d0315434319
Node: pickletools — Tools for pickle developers15434496
Ref: library/pickletools doc15434649
Ref: 4d0415434649
Ref: library/pickletools module-pickletools15434649
Ref: ac15434649
Ref: library/pickletools pickletools-tools-for-pickle-developers15434649
Ref: 4d0515434649
Ref: library/pickletools translation-repo15434649
Ref: 4d0615434649
Ref: pickletools — Tools for pickle developers-Footnote-115435414
Node: Command-line usage<8>15435485
Ref: library/pickletools command-line-usage15435617
Ref: 4d0715435617
Ref: library/pickletools pickletools-cli15435617
Ref: 2d1515435617
Node: Command-line options<6>15436572
Ref: library/pickletools command-line-options15436653
Ref: 4d0815436653
Ref: library/pickletools cmdoption-pickletools-a15436716
Ref: 4d0915436716
Ref: library/pickletools cmdoption-pickletools-annotate15436716
Ref: 4d0a15436716
Ref: library/pickletools cmdoption-pickletools-o15436802
Ref: 4d0b15436802
Ref: library/pickletools cmdoption-pickletools-output15436802
Ref: 4d0c15436802
Ref: library/pickletools cmdoption-pickletools-l15436892
Ref: 4d0d15436892
Ref: library/pickletools cmdoption-pickletools-indentlevel15436892
Ref: 4d0e15436892
Ref: library/pickletools cmdoption-pickletools-m15436993
Ref: 4d0f15436993
Ref: library/pickletools cmdoption-pickletools-memo15436993
Ref: 4d1015436993
Ref: library/pickletools cmdoption-pickletools-p15437105
Ref: 4d1115437105
Ref: library/pickletools cmdoption-pickletools-preamble15437105
Ref: 4d1215437105
Ref: library/pickletools cmdoption-pickletools-arg-pickle_file15437246
Ref: 4d1315437246
Node: Programmatic interface15437357
Ref: library/pickletools programmatic-interface15437489
Ref: 4d1415437489
Ref: library/pickletools pickletools dis15437556
Ref: ec015437556
Ref: library/pickletools pickletools genops15438401
Ref: 4d1515438401
Ref: library/pickletools pickletools optimize15438837
Ref: 2cfc15438837
Node: MS Windows Specific Services15439117
Ref: library/windows doc15439273
Ref: 4d1615439273
Ref: library/windows ms-windows-specific-services15439273
Ref: 4d1715439273
Ref: library/windows mswin-specific-services15439273
Ref: 220915439273
Ref: library/windows translation-repo15439273
Ref: 4d1815439273
Node: msvcrt — Useful routines from the MS VC++ runtime15439581
Ref: library/msvcrt doc15439740
Ref: 4d1915439740
Ref: library/msvcrt module-msvcrt15439740
Ref: 9715439740
Ref: library/msvcrt msvcrt-useful-routines-from-the-ms-vc-runtime15439740
Ref: 4d1a15439740
Node: File Operations15440798
Ref: library/msvcrt file-operations15440921
Ref: 4d1b15440921
Ref: library/msvcrt msvcrt-files15440921
Ref: 4d1c15440921
Ref: library/msvcrt msvcrt locking15440972
Ref: 474615440972
Ref: library/msvcrt msvcrt LK_LOCK15441636
Ref: 4d1d15441636
Ref: library/msvcrt msvcrt LK_RLCK15441661
Ref: 4d1e15441661
Ref: library/msvcrt msvcrt LK_NBLCK15441902
Ref: 4d1f15441902
Ref: library/msvcrt msvcrt LK_NBRLCK15441928
Ref: 4d2015441928
Ref: library/msvcrt msvcrt LK_UNLCK15442057
Ref: 4d2115442057
Ref: library/msvcrt msvcrt setmode15442164
Ref: 4d2215442164
Ref: library/msvcrt msvcrt open_osfhandle15442403
Ref: 474715442403
Ref: library/msvcrt msvcrt get_osfhandle15443055
Ref: 474515443055
Node: Console I/O15443315
Ref: library/msvcrt console-i-o15443462
Ref: 4d2315443462
Ref: library/msvcrt msvcrt-console15443462
Ref: 4d2415443462
Ref: library/msvcrt msvcrt kbhit15443505
Ref: 4d2515443505
Ref: library/msvcrt msvcrt getch15443629
Ref: 4d2615443629
Ref: library/msvcrt msvcrt getwch15444116
Ref: 15fc15444116
Ref: library/msvcrt msvcrt getche15444228
Ref: 4d2715444228
Ref: library/msvcrt msvcrt getwche15444375
Ref: 15fd15444375
Ref: library/msvcrt msvcrt putch15444489
Ref: 4d2815444489
Ref: library/msvcrt msvcrt putwch15444593
Ref: 15fe15444593
Ref: library/msvcrt msvcrt ungetch15444717
Ref: 4d2915444717
Ref: library/msvcrt msvcrt ungetwch15444930
Ref: 4d2a15444930
Node: Other Functions15445058
Ref: library/msvcrt msvcrt-other15445181
Ref: 4d2b15445181
Ref: library/msvcrt other-functions15445181
Ref: 4d2c15445181
Ref: library/msvcrt msvcrt heapmin15445232
Ref: 4d2d15445232
Ref: library/msvcrt msvcrt set_error_mode15445425
Ref: 4d2e15445425
Ref: library/msvcrt msvcrt OUT_TO_DEFAULT15445797
Ref: 4d3015445797
Ref: library/msvcrt msvcrt OUT_TO_STDERR15445940
Ref: 4d3115445940
Ref: library/msvcrt msvcrt OUT_TO_MSGBOX15446068
Ref: 4d3215446068
Ref: library/msvcrt msvcrt REPORT_ERRMODE15446193
Ref: 4d2f15446193
Ref: library/msvcrt msvcrt CrtSetReportMode15446327
Ref: 4d3315446327
Ref: library/msvcrt msvcrt CrtSetReportFile15446715
Ref: 4d3415446715
Ref: library/msvcrt msvcrt CRT_WARN15447112
Ref: 4d3615447112
Ref: library/msvcrt msvcrt CRT_ERROR15447227
Ref: 4d3715447227
Ref: library/msvcrt msvcrt CRT_ASSERT15447343
Ref: 4d3815447343
Ref: library/msvcrt msvcrt CRTDBG_MODE_DEBUG15447398
Ref: 4d3915447398
Ref: library/msvcrt msvcrt CRTDBG_MODE_FILE15447494
Ref: 4d3515447494
Ref: library/msvcrt msvcrt CRTDBG_MODE_WNDW15447711
Ref: 4d3a15447711
Ref: library/msvcrt msvcrt CRTDBG_REPORT_MODE15447869
Ref: 4d3b15447869
Ref: library/msvcrt msvcrt CRT_ASSEMBLY_VERSION15447961
Ref: 156715447961
Ref: library/msvcrt msvcrt VC_ASSEMBLY_PUBLICKEYTOKEN15448071
Ref: 156815448071
Ref: library/msvcrt msvcrt LIBRARIES_ASSEMBLY_NAME_PREFIX15448200
Ref: 156915448200
Node: winreg — Windows registry access15448335
Ref: library/winreg doc15448551
Ref: 4d3c15448551
Ref: library/winreg module-winreg15448551
Ref: 11c15448551
Ref: library/winreg translation-repo15448551
Ref: 4d3d15448551
Ref: library/winreg winreg-windows-registry-access15448551
Ref: 4d3e15448551
Ref: library/winreg exception-changed15449002
Ref: 4d4015449002
Node: Functions<13>15449248
Ref: library/winreg functions15449354
Ref: 4d4115449354
Ref: library/winreg id115449354
Ref: 4d4215449354
Ref: library/winreg winreg CloseKey15449438
Ref: 4d4315449438
Ref: library/winreg winreg ConnectRegistry15449759
Ref: 474c15449759
Ref: library/winreg winreg CreateKey15450456
Ref: 474d15450456
Ref: library/winreg winreg CreateKeyEx15451423
Ref: 156a15451423
Ref: library/winreg winreg DeleteKey15452768
Ref: 474e15452768
Ref: library/winreg winreg DeleteKeyEx15453522
Ref: 156b15453522
Ref: library/winreg winreg DeleteValue15454806
Ref: 474f15454806
Ref: library/winreg winreg EnumKey15455174
Ref: 475015455174
Ref: library/winreg winreg EnumValue15455846
Ref: 475115455846
Ref: library/winreg winreg ExpandEnvironmentStrings15457117
Ref: 15ff15457117
Ref: library/winreg winreg FlushKey15457468
Ref: 4d4a15457468
Ref: library/winreg winreg LoadKey15458288
Ref: 475215458288
Ref: library/winreg winreg OpenKey15459481
Ref: 475315459481
Ref: library/winreg winreg OpenKeyEx15459554
Ref: 4d4d15459554
Ref: library/winreg winreg QueryInfoKey15460647
Ref: 475515460647
Ref: library/winreg winreg QueryValue15461543
Ref: 475615461543
Ref: library/winreg winreg QueryValueEx15462420
Ref: 176b15462420
Ref: library/winreg winreg SaveKey15463296
Ref: 475715463296
Ref: library/winreg winreg SetValue15464338
Ref: 475815464338
Ref: library/winreg winreg SetValueEx15465517
Ref: 1aeb15465517
Ref: library/winreg winreg DisableReflectionKey15466765
Ref: 156c15466765
Ref: library/winreg winreg EnableReflectionKey15467397
Ref: 156d15467397
Ref: library/winreg winreg QueryReflectionKey15467906
Ref: 156e15467906
Ref: Functions<13>-Footnote-115468410
Ref: Functions<13>-Footnote-215468487
Node: Constants<10>15468564
Ref: library/winreg constants15468702
Ref: 4d5215468702
Ref: library/winreg id215468702
Ref: 4d5315468702
Node: HKEY_* Constants15468889
Ref: library/winreg hkey-constants15468977
Ref: 4d4515468977
Ref: library/winreg id315468977
Ref: 4d5415468977
Ref: library/winreg winreg HKEY_CLASSES_ROOT15469030
Ref: 4d5515469030
Ref: library/winreg winreg HKEY_CURRENT_USER15469281
Ref: 4d5615469281
Ref: library/winreg winreg HKEY_LOCAL_MACHINE15469584
Ref: 4d4c15469584
Ref: library/winreg winreg HKEY_USERS15469808
Ref: 4d4b15469808
Ref: library/winreg winreg HKEY_PERFORMANCE_DATA15470017
Ref: 4d5715470017
Ref: library/winreg winreg HKEY_CURRENT_CONFIG15470284
Ref: 4d5815470284
Ref: library/winreg winreg HKEY_DYN_DATA15470419
Ref: 4d5915470419
Node: Access Rights15470511
Ref: library/winreg access-rights15470619
Ref: 4d4715470619
Ref: library/winreg id415470619
Ref: 4d5a15470619
Ref: library/winreg winreg KEY_ALL_ACCESS15470730
Ref: 4d5b15470730
Ref: library/winreg winreg KEY_WRITE15471019
Ref: 4d4615471019
Ref: library/winreg winreg KEY_READ15471172
Ref: 4d4e15471172
Ref: library/winreg winreg KEY_EXECUTE15471351
Ref: 4d6115471351
Ref: library/winreg winreg KEY_QUERY_VALUE15471423
Ref: 4d5c15471423
Ref: library/winreg winreg KEY_SET_VALUE15471511
Ref: 4d5015471511
Ref: library/winreg winreg KEY_CREATE_SUB_KEY15471602
Ref: 4d5d15471602
Ref: library/winreg winreg KEY_ENUMERATE_SUB_KEYS15471692
Ref: 4d5e15471692
Ref: library/winreg winreg KEY_NOTIFY15471792
Ref: 4d5f15471792
Ref: library/winreg winreg KEY_CREATE_LINK15471926
Ref: 4d6015471926
Ref: Access Rights-Footnote-115472057
Node: 64-bit Specific15472134
Ref: library/winreg bit-access-rights15472199
Ref: 4d6215472199
Ref: library/winreg bit-specific15472199
Ref: 4d6315472199
Ref: library/winreg winreg KEY_WOW64_64KEY15472318
Ref: 4d4815472318
Ref: library/winreg winreg KEY_WOW64_32KEY15472506
Ref: 4d6415472506
Ref: 64-bit Specific-Footnote-115472730
Node: Value Types15472802
Ref: library/winreg id515472885
Ref: 4d6515472885
Ref: library/winreg value-types15472885
Ref: 4d5115472885
Ref: library/winreg winreg REG_BINARY15472980
Ref: 4d6615472980
Ref: library/winreg winreg REG_DWORD15473040
Ref: 4d6715473040
Ref: library/winreg winreg REG_DWORD_LITTLE_ENDIAN15473089
Ref: 4d6815473089
Ref: library/winreg winreg REG_DWORD_BIG_ENDIAN15473221
Ref: 4d6915473221
Ref: library/winreg winreg REG_EXPAND_SZ15473304
Ref: 4d4915473304
Ref: library/winreg winreg REG_LINK15473433
Ref: 4d6a15473433
Ref: library/winreg winreg REG_MULTI_SZ15473491
Ref: 1dab15473491
Ref: library/winreg winreg REG_NONE15473657
Ref: 4d6b15473657
Ref: library/winreg winreg REG_QWORD15473713
Ref: f0115473713
Ref: library/winreg winreg REG_QWORD_LITTLE_ENDIAN15473792
Ref: 4d6c15473792
Ref: library/winreg winreg REG_RESOURCE_LIST15473951
Ref: 4d6d15473951
Ref: library/winreg winreg REG_FULL_RESOURCE_DESCRIPTOR15474024
Ref: 4d6e15474024
Ref: library/winreg winreg REG_RESOURCE_REQUIREMENTS_LIST15474097
Ref: 4d6f15474097
Ref: library/winreg winreg REG_SZ15474178
Ref: 4d4f15474178
Ref: Value Types-Footnote-115474271
Node: Registry Handle Objects15474348
Ref: library/winreg handle-object15474464
Ref: 4d3f15474464
Ref: library/winreg registry-handle-objects15474464
Ref: 4d7015474464
Ref: library/winreg winreg PyHKEY Close15475477
Ref: 4d4415475477
Ref: library/winreg winreg PyHKEY Detach15475609
Ref: 475415475609
Ref: library/winreg winreg PyHKEY __enter__15476208
Ref: 4d7115476208
Ref: library/winreg winreg PyHKEY __exit__15476240
Ref: 4d7215476240
Node: winsound — Sound-playing interface for Windows15476635
Ref: library/winsound doc15476791
Ref: 4d7315476791
Ref: library/winsound module-winsound15476791
Ref: 11d15476791
Ref: library/winsound translation-repo15476791
Ref: 4d7415476791
Ref: library/winsound winsound-sound-playing-interface-for-windows15476791
Ref: 4d7515476791
Ref: library/winsound winsound Beep15477178
Ref: f0315477178
Ref: library/winsound winsound PlaySound15477566
Ref: f0515477566
Ref: library/winsound winsound MessageBeep15478138
Ref: f0415478138
Ref: library/winsound winsound SND_FILENAME15478745
Ref: 4d7615478745
Ref: library/winsound winsound SND_ALIAS15478878
Ref: 4d7715478878
Ref: library/winsound winsound SND_LOOP15480496
Ref: 4d7915480496
Ref: library/winsound winsound SND_MEMORY15480683
Ref: 4d7b15480683
Ref: library/winsound winsound SND_PURGE15481045
Ref: 4d7c15481045
Ref: library/winsound winsound SND_ASYNC15481205
Ref: 4d7a15481205
Ref: library/winsound winsound SND_NODEFAULT15481301
Ref: 4d7815481301
Ref: library/winsound winsound SND_NOSTOP15481424
Ref: 4d7d15481424
Ref: library/winsound winsound SND_NOWAIT15481504
Ref: 4d7e15481504
Ref: library/winsound winsound SND_APPLICATION15481662
Ref: 4d7f15481662
Ref: library/winsound winsound SND_SENTRY15481897
Ref: 4d8015481897
Ref: library/winsound winsound SND_SYNC15482018
Ref: 4d8115482018
Ref: library/winsound winsound SND_SYSTEM15482148
Ref: 4d8215482148
Ref: library/winsound winsound MB_ICONASTERISK15482289
Ref: 4d8315482289
Ref: library/winsound winsound MB_ICONEXCLAMATION15482367
Ref: 4d8415482367
Ref: library/winsound winsound MB_ICONHAND15482452
Ref: 4d8515482452
Ref: library/winsound winsound MB_ICONQUESTION15482523
Ref: 4d8615482523
Ref: library/winsound winsound MB_OK15482602
Ref: 4d8715482602
Ref: library/winsound winsound MB_ICONERROR15482670
Ref: 4d8815482670
Ref: library/winsound winsound MB_ICONINFORMATION15482771
Ref: 4d8915482771
Ref: library/winsound winsound MB_ICONSTOP15482881
Ref: 4d8a15482881
Ref: library/winsound winsound MB_ICONWARNING15482981
Ref: 4d8b15482981
Node: Unix-specific services15483091
Ref: library/unix doc15483257
Ref: 4d8c15483257
Ref: library/unix translation-repo15483257
Ref: 4d8d15483257
Ref: library/unix unix15483257
Ref: 4d8e15483257
Ref: library/unix unix-specific-services15483257
Ref: 4d8f15483257
Node: shlex — Simple lexical analysis15483916
Ref: library/shlex doc15484061
Ref: 4d9015484061
Ref: library/shlex module-shlex15484061
Ref: c915484061
Ref: library/shlex shlex-simple-lexical-analysis15484061
Ref: 4d9115484061
Ref: library/shlex shlex split15484582
Ref: 75f15484582
Ref: library/shlex shlex join15485184
Ref: c1e15485184
Ref: library/shlex shlex quote15485642
Ref: 58215485642
Ref: library/shlex shlex-quote-warning15485870
Ref: 373d15485870
Ref: library/shlex shlex shlex15487510
Ref: eca15487510
Ref: shlex — Simple lexical analysis-Footnote-115489764
Node: shlex Objects15489829
Ref: library/shlex id115489934
Ref: 4d9515489934
Ref: library/shlex shlex-objects15489934
Ref: 4d9615489934
Ref: library/shlex shlex shlex get_token15490038
Ref: 4d9715490038
Ref: library/shlex shlex shlex push_token15490401
Ref: 4d9815490401
Ref: library/shlex shlex shlex read_token15490483
Ref: 4d9a15490483
Ref: library/shlex shlex shlex sourcehook15490722
Ref: 4d9b15490722
Ref: library/shlex shlex shlex push_source15492261
Ref: 4d9d15492261
Ref: library/shlex shlex shlex pop_source15492564
Ref: 4d9e15492564
Ref: library/shlex shlex shlex error_leader15492763
Ref: 4d9f15492763
Ref: library/shlex shlex shlex commenters15493492
Ref: 4d9215493492
Ref: library/shlex shlex shlex wordchars15493714
Ref: 4d9415493714
Ref: library/shlex shlex shlex whitespace15494410
Ref: 4da115494410
Ref: library/shlex shlex shlex escape15494608
Ref: 4da215494608
Ref: library/shlex shlex shlex quotes15494773
Ref: 4da315494773
Ref: library/shlex shlex shlex escapedquotes15495058
Ref: 4da415495058
Ref: library/shlex shlex shlex whitespace_split15495287
Ref: 4da015495287
Ref: library/shlex shlex shlex infile15495830
Ref: 4d9315495830
Ref: library/shlex shlex shlex instream15496061
Ref: 4da515496061
Ref: library/shlex shlex shlex source15496186
Ref: 4d9c15496186
Ref: library/shlex shlex shlex debug15496775
Ref: 4da615496775
Ref: library/shlex shlex shlex lineno15497039
Ref: 4da715497039
Ref: library/shlex shlex shlex token15497135
Ref: 4da815497135
Ref: library/shlex shlex shlex eof15497252
Ref: 4d9915497252
Ref: library/shlex shlex shlex punctuation_chars15497428
Ref: 1d9e15497428
Node: Parsing Rules15497839
Ref: library/shlex parsing-rules15497987
Ref: 4da915497987
Ref: library/shlex shlex-parsing-rules15497987
Ref: 4daa15497987
Node: Improved Compatibility with Shells15500008
Ref: library/shlex improved-compatibility-with-shells15500134
Ref: 4dab15500134
Ref: library/shlex improved-shell-compatibility15500134
Ref: ecb15500134
Node: posix — The most common POSIX system calls15502969
Ref: library/posix doc15503152
Ref: 4dac15503152
Ref: library/posix module-posix15503152
Ref: b215503152
Ref: library/posix posix-the-most-common-posix-system-calls15503152
Ref: 4dad15503152
Ref: library/posix translation-repo15503152
Ref: 4dae15503152
Node: Large File Support15504385
Ref: library/posix large-file-support15504516
Ref: 4daf15504516
Ref: library/posix posix-large-files15504516
Ref: 4db015504516
Node: Notable Module Contents15505470
Ref: library/posix notable-module-contents15505601
Ref: 4db115505601
Ref: library/posix posix-contents15505601
Ref: 4db215505601
Ref: library/posix posix environ15505802
Ref: 4db315505802
Node: pwd — The password database15506996
Ref: library/pwd doc15507172
Ref: 4db415507172
Ref: library/pwd module-pwd15507172
Ref: b715507172
Ref: library/pwd pwd-the-password-database15507172
Ref: 4db515507172
Ref: library/pwd translation-repo15507172
Ref: 4db615507172
Ref: library/pwd pwd getpwuid15509340
Ref: 1dfa15509340
Ref: library/pwd pwd getpwnam15509446
Ref: 372d15509446
Ref: library/pwd pwd getpwall15509547
Ref: 4db715509547
Node: grp — The group database15509772
Ref: library/grp doc15509939
Ref: 4db815509939
Ref: library/grp grp-the-group-database15509939
Ref: 4db915509939
Ref: library/grp module-grp15509939
Ref: 6a15509939
Ref: library/grp translation-repo15509939
Ref: 4dba15509939
Ref: library/grp grp getgrgid15511549
Ref: f2415511549
Ref: library/grp grp getgrnam15511856
Ref: 372c15511856
Ref: library/grp grp getgrall15512032
Ref: 18d115512032
Node: termios — POSIX style tty control15512239
Ref: library/termios doc15512411
Ref: 4dbb15512411
Ref: library/termios module-termios15512411
Ref: e715512411
Ref: library/termios termios-posix-style-tty-control15512411
Ref: 4dbc15512411
Ref: library/termios translation-repo15512411
Ref: 4dbd15512411
Ref: library/termios termios tcgetattr15513426
Ref: 19db15513426
Ref: library/termios termios tcsetattr15514004
Ref: 1a5115514004
Ref: library/termios termios TCSANOW15514283
Ref: 4dbe15514283
Ref: library/termios termios TCSADRAIN15514357
Ref: 4dbf15514357
Ref: library/termios termios TCSAFLUSH15514458
Ref: 4dc015514458
Ref: library/termios termios tcsendbreak15514601
Ref: 4dc115514601
Ref: library/termios termios tcdrain15514815
Ref: 4dc215514815
Ref: library/termios termios tcflush15514938
Ref: 4dc315514938
Ref: library/termios termios tcflow15515196
Ref: 4dc415515196
Ref: library/termios termios tcgetwinsize15515476
Ref: 4dc515515476
Ref: library/termios termios tcsetwinsize15515720
Ref: 4dc615515720
Ref: termios — POSIX style tty control-Footnote-115516333
Node: Example<15>15516380
Ref: library/termios example15516463
Ref: 4dc715516463
Ref: library/termios termios-example15516463
Ref: 4dc815516463
Node: tty — Terminal control functions15517221
Ref: library/tty doc15517400
Ref: 4dc915517400
Ref: library/tty module-tty15517400
Ref: 10615517400
Ref: library/tty translation-repo15517400
Ref: 4dca15517400
Ref: library/tty tty-terminal-control-functions15517400
Ref: 4dcb15517400
Ref: library/tty tty cfmakeraw15517856
Ref: 1a2a15517856
Ref: library/tty tty cfmakecbreak15518080
Ref: 19de15518080
Ref: library/tty tty setraw15518654
Ref: 1a2915518654
Ref: library/tty tty setcbreak15519143
Ref: 19dd15519143
Ref: tty — Terminal control functions-Footnote-115520163
Node: pty — Pseudo-terminal utilities15520226
Ref: library/pty doc15520412
Ref: 4dcc15520412
Ref: library/pty module-pty15520412
Ref: b615520412
Ref: library/pty pty-pseudo-terminal-utilities15520412
Ref: 4dcd15520412
Ref: library/pty translation-repo15520412
Ref: 4dce15520412
Ref: library/pty pty fork15521092
Ref: 1ab115521092
Ref: library/pty pty openpty15521695
Ref: 30115521695
Ref: library/pty pty spawn15521974
Ref: 118415521974
Ref: pty — Pseudo-terminal utilities-Footnote-115524247
Node: Example<16>15524310
Ref: library/pty example15524391
Ref: 4dcf15524391
Ref: Example<16>-Footnote-115525610
Node: fcntl — The fcntl and ioctl system calls15525656
Ref: library/fcntl doc15525847
Ref: 4dd015525847
Ref: library/fcntl fcntl-the-fcntl-and-ioctl-system-calls15525847
Ref: 4dd115525847
Ref: library/fcntl module-fcntl15525847
Ref: 5d15525847
Ref: library/fcntl translation-repo15525847
Ref: 4dd215525847
Ref: library/fcntl fcntl fcntl15529499
Ref: 183915529499
Ref: library/fcntl fcntl ioctl15531532
Ref: 168215531532
Ref: library/fcntl fcntl flock15534279
Ref: 474415534279
Ref: library/fcntl fcntl lockf15534803
Ref: 15f315534803
Ref: library/fcntl fcntl LOCK_UN15535146
Ref: 4dd315535146
Ref: library/fcntl fcntl LOCK_SH15535213
Ref: 4dd415535213
Ref: library/fcntl fcntl LOCK_EX15535277
Ref: 4dd515535277
Ref: library/fcntl fcntl LOCK_NB15535345
Ref: 4dd615535345
Ref: fcntl — The fcntl and ioctl system calls-Footnote-115537650
Ref: fcntl — The fcntl and ioctl system calls-Footnote-215537695
Ref: fcntl — The fcntl and ioctl system calls-Footnote-315537740
Node: resource — Resource usage information15537785
Ref: library/resource doc15537982
Ref: 4dd715537982
Ref: library/resource module-resource15537982
Ref: c115537982
Ref: library/resource resource-resource-usage-information15537982
Ref: 4dd815537982
Ref: library/resource translation-repo15537982
Ref: 4dd915537982
Ref: library/resource resource error15538509
Ref: 4dda15538509
Ref: resource — Resource usage information-Footnote-115538788
Node: Resource Limits15538830
Ref: library/resource resource-limits15538944
Ref: 4ddb15538944
Ref: library/resource resource RLIM_INFINITY15539824
Ref: 17ad15539824
Ref: library/resource resource getrlimit15539928
Ref: 17ac15539928
Ref: library/resource resource setrlimit15540222
Ref: 17ae15540222
Ref: library/resource resource prlimit15541381
Ref: 118c15541381
Ref: library/resource resource RLIMIT_CORE15542977
Ref: 46e515542977
Ref: library/resource resource RLIMIT_CPU15543238
Ref: 4ddd15543238
Ref: library/resource resource RLIMIT_FSIZE15543605
Ref: 4dde15543605
Ref: library/resource resource RLIMIT_DATA15543701
Ref: 4ddf15543701
Ref: library/resource resource RLIMIT_STACK15543792
Ref: 4de015543792
Ref: library/resource resource RLIMIT_RSS15543989
Ref: 4de115543989
Ref: library/resource resource RLIMIT_NPROC15544107
Ref: 4de215544107
Ref: library/resource resource RLIMIT_NOFILE15544210
Ref: 4ddc15544210
Ref: library/resource resource RLIMIT_OFILE15544324
Ref: 4de315544324
Ref: library/resource resource RLIMIT_MEMLOCK15544407
Ref: 4de415544407
Ref: library/resource resource RLIMIT_VMEM15544505
Ref: 4de515544505
Ref: library/resource resource RLIMIT_AS15544714
Ref: 4de615544714
Ref: library/resource resource RLIMIT_MSGQUEUE15544835
Ref: 118d15544835
Ref: library/resource resource RLIMIT_NICE15545022
Ref: 118e15545022
Ref: library/resource resource RLIMIT_RTPRIO15545217
Ref: 118f15545217
Ref: library/resource resource RLIMIT_RTTIME15545374
Ref: 119015545374
Ref: library/resource resource RLIMIT_SIGPENDING15545629
Ref: 119115545629
Ref: library/resource resource RLIMIT_SBSIZE15545801
Ref: 119215545801
Ref: library/resource resource RLIMIT_SWAP15546105
Ref: 119315546105
Ref: library/resource resource RLIMIT_NPTS15546488
Ref: 119415546488
Ref: library/resource resource RLIMIT_KQUEUES15546665
Ref: 1c8e15546665
Ref: Resource Limits-Footnote-115546884
Ref: Resource Limits-Footnote-215546933
Ref: Resource Limits-Footnote-315546982
Node: Resource Usage15547049
Ref: library/resource resource-usage15547163
Ref: 4de715547163
Ref: library/resource resource getrusage15547278
Ref: 163815547278
Ref: library/resource resource getpagesize15551825
Ref: 4de815551825
Ref: library/resource resource RUSAGE_SELF15552130
Ref: 4de915552130
Ref: library/resource resource RUSAGE_CHILDREN15552331
Ref: 4dea15552331
Ref: library/resource resource RUSAGE_BOTH15552531
Ref: 4deb15552531
Ref: library/resource resource RUSAGE_THREAD15552729
Ref: 4dec15552729
Ref: Resource Usage-Footnote-115552962
Node: syslog — Unix syslog library routines15553011
Ref: library/syslog doc15553157
Ref: 4ded15553157
Ref: library/syslog module-syslog15553157
Ref: e215553157
Ref: library/syslog syslog-unix-syslog-library-routines15553157
Ref: 4dee15553157
Ref: library/syslog translation-repo15553157
Ref: 4def15553157
Ref: library/syslog syslog syslog15553796
Ref: 76315553796
Ref: library/syslog syslog openlog15555270
Ref: 76115555270
Ref: library/syslog syslog closelog15556633
Ref: 76215556633
Ref: library/syslog syslog setlogmask15557501
Ref: 474a15557501
Ref: library/syslog syslog LOG_EMERG15558106
Ref: 4df215558106
Ref: library/syslog syslog LOG_ALERT15558133
Ref: 4df315558133
Ref: library/syslog syslog LOG_CRIT15558160
Ref: 4df415558160
Ref: library/syslog syslog LOG_ERR15558186
Ref: 4df515558186
Ref: library/syslog syslog LOG_WARNING15558211
Ref: 4df615558211
Ref: library/syslog syslog LOG_NOTICE15558240
Ref: 4df715558240
Ref: library/syslog syslog LOG_INFO15558268
Ref: 4df015558268
Ref: library/syslog syslog LOG_DEBUG15558294
Ref: 4df815558294
Ref: library/syslog syslog LOG_AUTH15558359
Ref: 4df915558359
Ref: library/syslog syslog LOG_AUTHPRIV15558385
Ref: 4dfa15558385
Ref: library/syslog syslog LOG_CRON15558415
Ref: 4dfb15558415
Ref: library/syslog syslog LOG_DAEMON15558441
Ref: 4dfc15558441
Ref: library/syslog syslog LOG_FTP15558469
Ref: 4dfd15558469
Ref: library/syslog syslog LOG_INSTALL15558494
Ref: 4dfe15558494
Ref: library/syslog syslog LOG_KERN15558523
Ref: 4dff15558523
Ref: library/syslog syslog LOG_LAUNCHD15558549
Ref: 4e0015558549
Ref: library/syslog syslog LOG_LPR15558578
Ref: 4e0115558578
Ref: library/syslog syslog LOG_MAIL15558603
Ref: 4e0215558603
Ref: library/syslog syslog LOG_NETINFO15558629
Ref: 4e0315558629
Ref: library/syslog syslog LOG_NEWS15558658
Ref: 4e0415558658
Ref: library/syslog syslog LOG_RAS15558684
Ref: 4e0515558684
Ref: library/syslog syslog LOG_REMOTEAUTH15558709
Ref: 4e0615558709
Ref: library/syslog syslog LOG_SYSLOG15558741
Ref: 4e0715558741
Ref: library/syslog syslog LOG_USER15558769
Ref: 4df115558769
Ref: library/syslog syslog LOG_UUCP15558795
Ref: 4e0815558795
Ref: library/syslog syslog LOG_LOCAL015558821
Ref: 4e0915558821
Ref: library/syslog syslog LOG_LOCAL115558849
Ref: 4e0a15558849
Ref: library/syslog syslog LOG_LOCAL215558877
Ref: 4e0b15558877
Ref: library/syslog syslog LOG_LOCAL315558905
Ref: 4e0c15558905
Ref: library/syslog syslog LOG_LOCAL415558933
Ref: 4e0d15558933
Ref: library/syslog syslog LOG_LOCAL515558961
Ref: 4e0e15558961
Ref: library/syslog syslog LOG_LOCAL615558989
Ref: 4e0f15558989
Ref: library/syslog syslog LOG_LOCAL715559017
Ref: 4e1015559017
Ref: library/syslog syslog LOG_PID15559480
Ref: 4e1115559480
Ref: library/syslog syslog LOG_CONS15559505
Ref: 4e1215559505
Ref: library/syslog syslog LOG_NDELAY15559531
Ref: 4e1315559531
Ref: library/syslog syslog LOG_ODELAY15559559
Ref: 4e1415559559
Ref: library/syslog syslog LOG_NOWAIT15559587
Ref: 4e1515559587
Ref: library/syslog syslog LOG_PERROR15559615
Ref: 4e1615559615
Node: Examples<37>15559835
Ref: library/syslog examples15559923
Ref: 4e1715559923
Node: Simple example15559991
Ref: library/syslog simple-example15560054
Ref: 4e1815560054
Node: Modules command-line interface CLI15560566
Ref: library/cmdline doc15560722
Ref: 4e1915560722
Ref: library/cmdline library-cmdline15560722
Ref: 4e1a15560722
Ref: library/cmdline modules-command-line-interface-cli15560722
Ref: 4e1b15560722
Ref: library/cmdline translation-repo15560722
Ref: 4e1c15560722
Node: Superseded Modules15562240
Ref: library/superseded doc15562389
Ref: 4e1d15562389
Ref: library/superseded superseded15562389
Ref: 4e1e15562389
Ref: library/superseded superseded-modules15562389
Ref: 4e1f15562389
Ref: library/superseded translation-repo15562389
Ref: 4e2015562389
Ref: Superseded Modules-Footnote-115563486
Node: getopt — C-style parser for command line options15563528
Ref: library/getopt doc15563633
Ref: 4e2115563633
Ref: library/getopt getopt-c-style-parser-for-command-line-options15563633
Ref: 4e2215563633
Ref: library/getopt module-getopt15563633
Ref: 6515563633
Ref: library/getopt getopt getopt15565057
Ref: 16c215565057
Ref: library/getopt getopt gnu_getopt15567487
Ref: 16c115567487
Ref: library/getopt getopt GetoptError15568588
Ref: 18d215568588
Ref: library/getopt getopt error15569168
Ref: 4e2315569168
Ref: getopt — C-style parser for command line options-Footnote-115573157
Node: Removed Modules15573223
Ref: library/removed doc15573364
Ref: 4e2415573364
Ref: library/removed removed15573364
Ref: 4e2515573364
Ref: library/removed removed-modules15573364
Ref: 4e2615573364
Ref: library/removed translation-repo15573364
Ref: 4e2715573364
Node: aifc — Read and write AIFF and AIFC files15574687
Ref: library/aifc doc15574848
Ref: 4e2815574848
Ref: library/aifc aifc-read-and-write-aiff-and-aifc-files15574848
Ref: 4e2915574848
Ref: library/aifc module-aifc15574848
Ref: 515574848
Ref: aifc — Read and write AIFF and AIFC files-Footnote-115575319
Ref: aifc — Read and write AIFF and AIFC files-Footnote-215575361
Node: asynchat — Asynchronous socket command/response handler15575416
Ref: library/asynchat doc15575626
Ref: 4e2a15575626
Ref: library/asynchat asynchat-asynchronous-socket-command-response-handler15575626
Ref: 4e2b15575626
Ref: library/asynchat module-asynchat15575626
Ref: a15575626
Ref: library/asynchat translation-repo15575626
Ref: 4e2c15575626
Ref: asynchat — Asynchronous socket command/response handler-Footnote-115576189
Ref: asynchat — Asynchronous socket command/response handler-Footnote-215576231
Node: asyncore — Asynchronous socket handler15576290
Ref: library/asyncore doc15576494
Ref: 4e2d15576494
Ref: library/asyncore asyncore-asynchronous-socket-handler15576494
Ref: 4e2e15576494
Ref: library/asyncore module-asyncore15576494
Ref: c15576494
Ref: library/asyncore translation-repo15576494
Ref: 4e2f15576494
Ref: asyncore — Asynchronous socket handler-Footnote-115577023
Ref: asyncore — Asynchronous socket handler-Footnote-215577065
Node: audioop — Manipulate raw audio data15577124
Ref: library/audioop doc15577311
Ref: 4e3015577311
Ref: library/audioop audioop-manipulate-raw-audio-data15577311
Ref: 4e3115577311
Ref: library/audioop module-audioop15577311
Ref: e15577311
Ref: library/audioop translation-repo15577311
Ref: 4e3215577311
Ref: audioop — Manipulate raw audio data-Footnote-115577773
Ref: audioop — Manipulate raw audio data-Footnote-215577815
Node: cgi — Common Gateway Interface support15577873
Ref: library/cgi doc15578063
Ref: 4e3315578063
Ref: library/cgi cgi-common-gateway-interface-support15578063
Ref: 4e3415578063
Ref: library/cgi module-cgi15578063
Ref: 1615578063
Ref: library/cgi translation-repo15578063
Ref: 4e3515578063
Ref: cgi — Common Gateway Interface support-Footnote-115578687
Ref: cgi — Common Gateway Interface support-Footnote-215578729
Ref: cgi — Common Gateway Interface support-Footnote-315578774
Node: cgitb — Traceback manager for CGI scripts15578828
Ref: library/cgitb doc15579012
Ref: 4e3615579012
Ref: library/cgitb cgitb-traceback-manager-for-cgi-scripts15579012
Ref: 4e3715579012
Ref: library/cgitb module-cgitb15579012
Ref: 1715579012
Ref: library/cgitb translation-repo15579012
Ref: 4e3815579012
Ref: cgitb — Traceback manager for CGI scripts-Footnote-115579647
Ref: cgitb — Traceback manager for CGI scripts-Footnote-215579689
Ref: cgitb — Traceback manager for CGI scripts-Footnote-315579734
Node: chunk — Read IFF chunked data15579790
Ref: library/chunk doc15579976
Ref: 4e3915579976
Ref: library/chunk chunk-read-iff-chunked-data15579976
Ref: 4e3a15579976
Ref: library/chunk module-chunk15579976
Ref: 1815579976
Ref: library/chunk translation-repo15579976
Ref: 4e3b15579976
Ref: chunk — Read IFF chunked data-Footnote-115580424
Ref: chunk — Read IFF chunked data-Footnote-215580466
Node: crypt — Function to check Unix passwords15580522
Ref: library/crypt doc15580717
Ref: 4e3c15580717
Ref: library/crypt crypt-function-to-check-unix-passwords15580717
Ref: 4e3d15580717
Ref: library/crypt module-crypt15580717
Ref: 2c15580717
Ref: library/crypt translation-repo15580717
Ref: 4e3e15580717
Ref: crypt — Function to check Unix passwords-Footnote-115581442
Ref: crypt — Function to check Unix passwords-Footnote-215581484
Ref: crypt — Function to check Unix passwords-Footnote-315581530
Ref: crypt — Function to check Unix passwords-Footnote-415581571
Ref: crypt — Function to check Unix passwords-Footnote-515581617
Node: distutils — Building and installing Python modules15581673
Ref: library/distutils doc15581878
Ref: 4e3f15581878
Ref: library/distutils distutils-building-and-installing-python-modules15581878
Ref: 4e4015581878
Ref: library/distutils module-distutils15581878
Ref: 3d15581878
Ref: library/distutils translation-repo15581878
Ref: 4e4115581878
Ref: distutils — Building and installing Python modules-Footnote-115582403
Ref: distutils — Building and installing Python modules-Footnote-215582445
Ref: distutils — Building and installing Python modules-Footnote-315582504
Node: imghdr — Determine the type of an image15582564
Ref: library/imghdr doc15582762
Ref: 4e4215582762
Ref: library/imghdr imghdr-determine-the-type-of-an-image15582762
Ref: 4e4315582762
Ref: library/imghdr module-imghdr15582762
Ref: 7915582762
Ref: library/imghdr translation-repo15582762
Ref: 4e4415582762
Ref: imghdr — Determine the type of an image-Footnote-115583404
Ref: imghdr — Determine the type of an image-Footnote-215583446
Ref: imghdr — Determine the type of an image-Footnote-315583489
Ref: imghdr — Determine the type of an image-Footnote-415583533
Ref: imghdr — Determine the type of an image-Footnote-515583580
Node: imp — Access the import internals15583637
Ref: library/imp doc15583816
Ref: 4e4515583816
Ref: library/imp imp-access-the-import-internals15583816
Ref: 4e4615583816
Ref: library/imp module-imp15583816
Ref: 7a15583816
Ref: library/imp translation-repo15583816
Ref: 4e4715583816
Ref: imp — Access the import internals-Footnote-115584338
Node: mailcap — Mailcap file handling15584392
Ref: library/mailcap doc15584581
Ref: 4e4815584581
Ref: library/mailcap mailcap-mailcap-file-handling15584581
Ref: 4e4915584581
Ref: library/mailcap module-mailcap15584581
Ref: 9015584581
Ref: library/mailcap translation-repo15584581
Ref: 4e4a15584581
Ref: mailcap — Mailcap file handling-Footnote-115585037
Ref: mailcap — Mailcap file handling-Footnote-215585079
Node: msilib — Read and write Microsoft Installer files15585137
Ref: library/msilib doc15585336
Ref: 4e4b15585336
Ref: library/msilib module-msilib15585336
Ref: 9615585336
Ref: library/msilib msilib-read-and-write-microsoft-installer-files15585336
Ref: 4e4c15585336
Ref: library/msilib translation-repo15585336
Ref: 4e4d15585336
Ref: msilib — Read and write Microsoft Installer files-Footnote-115585827
Ref: msilib — Read and write Microsoft Installer files-Footnote-215585869
Node: nis — Interface to Sun’s NIS Yellow Pages15585926
Ref: library/nis doc15586124
Ref: 4e4e15586124
Ref: library/nis module-nis15586124
Ref: a015586124
Ref: library/nis nis-interface-to-suns-nis-yellow-pages15586124
Ref: 4e4f15586124
Ref: library/nis translation-repo15586124
Ref: 4e5015586124
Ref: nis — Interface to Sun’s NIS Yellow Pages-Footnote-115586602
Ref: nis — Interface to Sun’s NIS Yellow Pages-Footnote-215586644
Node: nntplib — NNTP protocol client15586698
Ref: library/nntplib doc15586899
Ref: 4e5115586899
Ref: library/nntplib module-nntplib15586899
Ref: a115586899
Ref: library/nntplib nntplib-nntp-protocol-client15586899
Ref: 4e5215586899
Ref: library/nntplib translation-repo15586899
Ref: 4e5315586899
Ref: nntplib — NNTP protocol client-Footnote-115587353
Ref: nntplib — NNTP protocol client-Footnote-215587395
Node: ossaudiodev — Access to OSS-compatible audio devices15587453
Ref: library/ossaudiodev doc15587647
Ref: 4e5415587647
Ref: library/ossaudiodev module-ossaudiodev15587647
Ref: a715587647
Ref: library/ossaudiodev ossaudiodev-access-to-oss-compatible-audio-devices15587647
Ref: 4e5515587647
Ref: library/ossaudiodev translation-repo15587647
Ref: 4e5615587647
Ref: ossaudiodev — Access to OSS-compatible audio devices-Footnote-115588149
Ref: ossaudiodev — Access to OSS-compatible audio devices-Footnote-215588191
Node: pipes — Interface to shell pipelines15588253
Ref: library/pipes doc15588436
Ref: 4e5715588436
Ref: library/pipes module-pipes15588436
Ref: ad15588436
Ref: library/pipes pipes-interface-to-shell-pipelines15588436
Ref: 4e5815588436
Ref: library/pipes translation-repo15588436
Ref: 4e5915588436
Ref: pipes — Interface to shell pipelines-Footnote-115588967
Ref: pipes — Interface to shell pipelines-Footnote-215589009
Node: smtpd — SMTP Server15589065
Ref: library/smtpd doc15589233
Ref: 4e5a15589233
Ref: library/smtpd module-smtpd15589233
Ref: ce15589233
Ref: library/smtpd smtpd-smtp-server15589233
Ref: 4e5b15589233
Ref: library/smtpd translation-repo15589233
Ref: 4e5c15589233
Ref: smtpd — SMTP Server-Footnote-115589794
Ref: smtpd — SMTP Server-Footnote-215589836
Ref: smtpd — SMTP Server-Footnote-315589879
Node: sndhdr — Determine type of sound file15589935
Ref: library/sndhdr doc15590102
Ref: 4e5d15590102
Ref: library/sndhdr module-sndhdr15590102
Ref: d015590102
Ref: library/sndhdr sndhdr-determine-type-of-sound-file15590102
Ref: 4e5e15590102
Ref: library/sndhdr translation-repo15590102
Ref: 4e5f15590102
Ref: sndhdr — Determine type of sound file-Footnote-115590738
Ref: sndhdr — Determine type of sound file-Footnote-215590780
Ref: sndhdr — Determine type of sound file-Footnote-315590823
Ref: sndhdr — Determine type of sound file-Footnote-415590867
Ref: sndhdr — Determine type of sound file-Footnote-515590914
Node: spwd — The shadow password database15590971
Ref: library/spwd doc15591154
Ref: 4e6015591154
Ref: library/spwd module-spwd15591154
Ref: d315591154
Ref: library/spwd spwd-the-shadow-password-database15591154
Ref: 4e6115591154
Ref: library/spwd translation-repo15591154
Ref: 4e6215591154
Ref: spwd — The shadow password database-Footnote-115591751
Ref: spwd — The shadow password database-Footnote-215591793
Ref: spwd — The shadow password database-Footnote-315591838
Node: sunau — Read and write Sun AU files15591893
Ref: library/sunau doc15592064
Ref: 4e6315592064
Ref: library/sunau module-sunau15592064
Ref: dd15592064
Ref: library/sunau sunau-read-and-write-sun-au-files15592064
Ref: 4e6415592064
Ref: library/sunau translation-repo15592064
Ref: 4e6515592064
Ref: sunau — Read and write Sun AU files-Footnote-115592526
Ref: sunau — Read and write Sun AU files-Footnote-215592568
Node: telnetlib — Telnet client15592624
Ref: library/telnetlib doc15592797
Ref: 4e6615592797
Ref: library/telnetlib module-telnetlib15592797
Ref: e515592797
Ref: library/telnetlib telnetlib-telnet-client15592797
Ref: 4e6715592797
Ref: library/telnetlib translation-repo15592797
Ref: 4e6815592797
Ref: telnetlib — Telnet client-Footnote-115593397
Ref: telnetlib — Telnet client-Footnote-215593439
Ref: telnetlib — Telnet client-Footnote-315593484
Ref: telnetlib — Telnet client-Footnote-415593527
Node: uu — Encode and decode uuencode files15593587
Ref: library/uu doc15593760
Ref: 4e6915593760
Ref: library/uu module-uu15593760
Ref: 11515593760
Ref: library/uu translation-repo15593760
Ref: 4e6a15593760
Ref: library/uu uu-encode-and-decode-uuencode-files15593760
Ref: 4e6b15593760
Ref: uu — Encode and decode uuencode files-Footnote-115594223
Ref: uu — Encode and decode uuencode files-Footnote-215594265
Node: xdrlib — Encode and decode XDR data15594318
Ref: library/xdrlib doc15594455
Ref: 4e6c15594455
Ref: library/xdrlib module-xdrlib15594455
Ref: 12515594455
Ref: library/xdrlib translation-repo15594455
Ref: 4e6d15594455
Ref: library/xdrlib xdrlib-encode-and-decode-xdr-data15594455
Ref: 4e6e15594455
Ref: library/security_warnings security-warnings15594882
Ref: 4e6f15594882
Ref: xdrlib — Encode and decode XDR data-Footnote-115594918
Ref: xdrlib — Encode and decode XDR data-Footnote-215594960
Node: Security Considerations<3>15595017
Ref: library/security_warnings doc15595131
Ref: 4e7015595131
Ref: library/security_warnings security-considerations15595131
Ref: 4e7115595131
Ref: library/security_warnings translation-repo15595131
Ref: 4e7215595131
Ref: Security Considerations<3>-Footnote-115596908
Node: Extending and Embedding the Python Interpreter15596967
Ref: extending/index doc15597127
Ref: 4e7315597127
Ref: extending/index extending-and-embedding-the-python-interpreter15597127
Ref: 4e7415597127
Ref: extending/index extending-index15597127
Ref: 1fa515597127
Ref: extending/index translation-repo15597127
Ref: 4e7515597127
Node: Recommended third party tools15598429
Ref: extending/index recommended-third-party-tools15598595
Ref: 4e7615598595
Node: Creating extensions without third party tools15598908
Ref: extending/index creating-extensions-without-third-party-tools15599136
Ref: 4e7815599136
Ref: Creating extensions without third party tools-Footnote-115599871
Node: Extending Python with C or C++15599913
Ref: extending/extending doc15600067
Ref: 4e7915600067
Ref: extending/extending extending-intro15600067
Ref: 4e7a15600067
Ref: extending/extending extending-python-with-c-or-c15600067
Ref: 4e7b15600067
Ref: Extending Python with C or C++-Footnote-115601998
Node: A Simple Example15602035
Ref: extending/extending a-simple-example15602159
Ref: 4e7c15602159
Ref: extending/extending extending-simpleexample15602159
Ref: 4e7d15602159
Ref: A Simple Example-Footnote-115606647
Node: Intermezzo Errors and Exceptions15606797
Ref: extending/extending extending-errors15606949
Ref: 4e7e15606949
Ref: extending/extending intermezzo-errors-and-exceptions15606949
Ref: 4e7f15606949
Node: Back to the Example15615041
Ref: extending/extending back-to-the-example15615232
Ref: 4e8615615232
Ref: extending/extending backtoexample15615232
Ref: 4e8715615232
Node: The Module’s Method Table and Initialization Function15616887
Ref: extending/extending methodtable15617069
Ref: 4e8915617069
Ref: extending/extending the-module-s-method-table-and-initialization-function15617069
Ref: 4e8a15617069
Node: Compilation and Linkage15622069
Ref: extending/extending compilation15622263
Ref: 4e8e15622263
Ref: extending/extending compilation-and-linkage15622263
Ref: 4e8f15622263
Node: Calling Python Functions from C15623737
Ref: extending/extending calling-python-functions-from-c15623920
Ref: 4e9115623920
Ref: extending/extending callingpython15623920
Ref: 4e9215623920
Node: Extracting Parameters in Extension Functions15630598
Ref: extending/extending extracting-parameters-in-extension-functions15630800
Ref: 4e9615630800
Ref: extending/extending parsetuple15630800
Ref: 4e9315630800
Node: Keyword Parameters for Extension Functions15633433
Ref: extending/extending keyword-parameters-for-extension-functions15633629
Ref: 4e9715633629
Ref: extending/extending parsetupleandkeywords15633629
Ref: 4e9815633629
Node: Building Arbitrary Values15636332
Ref: extending/extending building-arbitrary-values15636500
Ref: 4e9915636500
Ref: extending/extending buildvalue15636500
Ref: 4e9a15636500
Node: Reference Counts15638586
Ref: extending/extending refcounts15638737
Ref: 4e9415638737
Ref: extending/extending reference-counts15638737
Ref: 4e9b15638737
Node: Reference Counting in Python15643180
Ref: extending/extending refcountsinpython15643285
Ref: 4e9c15643285
Ref: extending/extending reference-counting-in-python15643285
Ref: 4e9d15643285
Ref: Reference Counting in Python-Footnote-115645660
Ref: Reference Counting in Python-Footnote-215645782
Node: Ownership Rules15645953
Ref: extending/extending ownership-rules15646075
Ref: 4e9e15646075
Ref: extending/extending ownershiprules15646075
Ref: 4e9f15646075
Node: Thin Ice15648537
Ref: extending/extending thin-ice15648644
Ref: 4ea315648644
Ref: extending/extending thinice15648644
Ref: 4ea415648644
Ref: Thin Ice-Footnote-115652370
Node: NULL Pointers15652412
Ref: extending/extending null-pointers15652495
Ref: 4ea715652495
Ref: extending/extending nullpointers15652495
Ref: 4ea815652495
Ref: NULL Pointers-Footnote-115654116
Node: Writing Extensions in C++15654251
Ref: extending/extending cplusplus15654418
Ref: 4ea915654418
Ref: extending/extending writing-extensions-in-c15654418
Ref: 4eaa15654418
Node: Providing a C API for an Extension Module15655138
Ref: extending/extending providing-a-c-api-for-an-extension-module15655280
Ref: 4eab15655280
Ref: extending/extending using-capsules15655280
Ref: 156515655280
Node: Defining Extension Types Tutorial15663839
Ref: extending/newtypes_tutorial doc15664042
Ref: 1ba315664042
Ref: extending/newtypes_tutorial defining-extension-types-tutorial15664042
Ref: 4ead15664042
Ref: extending/newtypes_tutorial defining-new-types15664042
Ref: 4eae15664042
Ref: extending/newtypes_tutorial translation-repo15664042
Ref: 4eaf15664042
Node: The Basics15664686
Ref: extending/newtypes_tutorial dnt-basics15664819
Ref: 4eb015664819
Ref: extending/newtypes_tutorial the-basics15664819
Ref: 4eb115664819
Node: Adding data and methods to the Basic example15674226
Ref: extending/newtypes_tutorial adding-data-and-methods-to-the-basic-example15674412
Ref: 4eb715674412
Ref: Adding data and methods to the Basic example-Footnote-115691565
Ref: Adding data and methods to the Basic example-Footnote-215691658
Node: Providing finer control over data attributes15691795
Ref: extending/newtypes_tutorial providing-finer-control-over-data-attributes15692007
Ref: 4ebf15692007
Ref: Providing finer control over data attributes-Footnote-115702131
Node: Supporting cyclic garbage collection15702511
Ref: extending/newtypes_tutorial supporting-cyclic-garbage-collection15702702
Ref: 4ec115702702
Ref: Supporting cyclic garbage collection-Footnote-115713672
Node: Subclassing other types15713846
Ref: extending/newtypes_tutorial subclassing-other-types15713984
Ref: 4ec315713984
Node: Defining Extension Types Assorted Topics15719324
Ref: extending/newtypes doc15719526
Ref: 4ec515719526
Ref: extending/newtypes defining-extension-types-assorted-topics15719526
Ref: 4ec615719526
Ref: extending/newtypes new-types-topics15719526
Ref: 4ec715719526
Ref: extending/newtypes translation-repo15719526
Ref: 4ec815719526
Ref: extending/newtypes dnt-type-methods15719623
Ref: 4ec915719623
Node: Finalization and De-allocation15724854
Ref: extending/newtypes finalization-and-de-allocation15724989
Ref: 4eca15724989
Ref: Finalization and De-allocation-Footnote-115728597
Node: Object Presentation15728639
Ref: extending/newtypes object-presentation15728803
Ref: 4ecc15728803
Node: Attribute Management15730560
Ref: extending/newtypes attribute-management15730711
Ref: 4ecf15730711
Node: Generic Attribute Management15732260
Ref: extending/newtypes generic-attribute-management15732388
Ref: 4ebc15732388
Ref: extending/newtypes id115732388
Ref: 4ed015732388
Node: Type-specific Attribute Management15735960
Ref: extending/newtypes type-specific-attribute-management15736088
Ref: 4ed515736088
Node: Object Comparison15737890
Ref: extending/newtypes object-comparison15738047
Ref: 4ed815738047
Node: Abstract Protocol Support15739917
Ref: extending/newtypes abstract-protocol-support15740076
Ref: 4edb15740076
Node: Weak Reference Support15745891
Ref: extending/newtypes weak-reference-support15746049
Ref: 4ee015746049
Ref: extending/newtypes weakref-support15746049
Ref: 29b315746049
Node: More Suggestions15747309
Ref: extending/newtypes more-suggestions15747433
Ref: 4ee115747433
Node: Building C and C++ Extensions15748406
Ref: extending/building doc15748615
Ref: 4ee215748615
Ref: extending/building building15748615
Ref: 4e9015748615
Ref: extending/building building-c-and-c-extensions15748615
Ref: 4ee315748615
Ref: extending/building translation-repo15748615
Ref: 4ee415748615
Ref: extending/building install-index15748900
Ref: 10fb15748900
Node: Building C and C++ Extensions with setuptools15748961
Ref: extending/building building-c-and-c-extensions-with-setuptools15749072
Ref: 4ee615749072
Ref: extending/building setuptools-index15749072
Ref: 10fc15749072
Node: Building C and C++ Extensions on Windows15749579
Ref: extending/windows doc15749739
Ref: 4ee715749739
Ref: extending/windows building-c-and-c-extensions-on-windows15749739
Ref: 4ee815749739
Ref: extending/windows building-on-windows15749739
Ref: 220d15749739
Ref: extending/windows translation-repo15749739
Ref: 4ee915749739
Node: A Cookbook Approach15751008
Ref: extending/windows a-cookbook-approach15751149
Ref: 4eea15751149
Ref: extending/windows win-cookbook15751149
Ref: 4eeb15751149
Ref: A Cookbook Approach-Footnote-115751779
Node: Differences Between Unix and Windows15751857
Ref: extending/windows differences-between-unix-and-windows15752029
Ref: 4eec15752029
Ref: extending/windows dynamic-linking15752029
Ref: 4eed15752029
Ref: extending/windows c Py_NO_LINK_LIB15754952
Ref: 44415754952
Node: Using DLLs in Practice15755136
Ref: extending/windows using-dlls-in-practice15755280
Ref: 4eee15755280
Ref: extending/windows win-dlls15755280
Ref: 4eef15755280
Node: Embedding the CPython runtime in a larger application15758066
Ref: extending/index embedding-the-cpython-runtime-in-a-larger-application15758256
Ref: 4ef115758256
Node: Embedding Python in Another Application15758698
Ref: extending/embedding doc15758827
Ref: 4ef215758827
Ref: extending/embedding embedding15758827
Ref: 224415758827
Ref: extending/embedding embedding-python-in-another-application15758827
Ref: 4ef315758827
Node: Very High Level Embedding15761175
Ref: extending/embedding high-level-embedding15761329
Ref: 4ef615761329
Ref: extending/embedding very-high-level-embedding15761329
Ref: 4ef715761329
Node: Beyond Very High Level Embedding An overview15763661
Ref: extending/embedding beyond-very-high-level-embedding-an-overview15763838
Ref: 4ef815763838
Ref: extending/embedding lower-level-embedding15763838
Ref: 4ef915763838
Node: Pure Embedding15765557
Ref: extending/embedding id115765734
Ref: 4efa15765734
Ref: extending/embedding pure-embedding15765734
Ref: 4efb15765734
Node: Extending Embedded Python15770359
Ref: extending/embedding extending-embedded-python15770515
Ref: 4efd15770515
Ref: extending/embedding extending-with-embedding15770515
Ref: 4efe15770515
Node: Embedding Python in C++15772552
Ref: extending/embedding embedding-python-in-c15772739
Ref: 4eff15772739
Ref: extending/embedding embeddingincplusplus15772739
Ref: 4f0015772739
Node: Compiling and Linking under Unix-like systems15773111
Ref: extending/embedding compiling15773264
Ref: 4efc15773264
Ref: extending/embedding compiling-and-linking-under-unix-like-systems15773264
Ref: 4f0115773264
Node: Python/C API Reference Manual15775461
Ref: c-api/index doc15775619
Ref: 4f0315775619
Ref: c-api/index c-api-index15775619
Ref: 1fa615775619
Ref: c-api/index python-c-api-reference-manual15775619
Ref: 4f0415775619
Ref: c-api/index translation-repo15775619
Ref: 4f0515775619
Node: Introduction<13>15776505
Ref: c-api/intro doc15776611
Ref: 4f0615776611
Ref: c-api/intro api-intro15776611
Ref: 4f0715776611
Ref: c-api/intro introduction15776611
Ref: 4f0815776611
Node: Language version compatibility15778285
Ref: c-api/intro language-version-compatibility15778393
Ref: 4f0915778393
Node: Coding standards15778690
Ref: c-api/intro coding-standards15778820
Ref: 4f0a15778820
Ref: Coding standards-Footnote-115779259
Node: Include Files15779301
Ref: c-api/intro api-includes15779414
Ref: 98815779414
Ref: c-api/intro include-files15779414
Ref: 4f0b15779414
Node: Useful macros15781962
Ref: c-api/intro useful-macros15782093
Ref: 4f0c15782093
Ref: c-api/intro c Py_ABS15782416
Ref: 4f0d15782416
Ref: c-api/intro c Py_ALWAYS_INLINE15782651
Ref: 1c5315782651
Ref: c-api/intro c Py_CHARMASK15783629
Ref: 4f0e15783629
Ref: c-api/intro c Py_DEPRECATED15783811
Ref: c9d15783811
Ref: c-api/intro c Py_GETENV15784090
Ref: 4f0f15784090
Ref: c-api/intro c Py_LOCAL15784267
Ref: 165115784267
Ref: c-api/intro c Py_LOCAL_INLINE15784500
Ref: 165215784500
Ref: c-api/intro c Py_LOCAL_SYMBOL15784635
Ref: 4f1015784635
Ref: c-api/intro c Py_MAX15784924
Ref: 4f1115784924
Ref: c-api/intro c Py_MEMBER_SIZE15785040
Ref: 4f1215785040
Ref: c-api/intro c Py_MEMCPY15785185
Ref: 197815785185
Ref: c-api/intro c Py_MIN15785419
Ref: 4f1315785419
Ref: c-api/intro c Py_NO_INLINE15785535
Ref: 17ea15785535
Ref: c-api/intro c Py_STRINGIFY15785835
Ref: 4f1415785835
Ref: c-api/intro c Py_UNREACHABLE15785988
Ref: db015785988
Ref: c-api/intro c Py_UNUSED15787143
Ref: 1a7215787143
Ref: c-api/intro c Py_BUILD_ASSERT15787367
Ref: 199b15787367
Ref: c-api/intro c Py_BUILD_ASSERT_EXPR15787676
Ref: 199c15787676
Ref: c-api/intro c PyDoc_STRVAR15788079
Ref: 1d4315788079
Ref: c-api/intro c PyDoc_STR15788656
Ref: 1b7e15788656
Ref: c-api/intro c PyDoc_VAR15789169
Ref: 1dd815789169
Ref: c-api/intro c Py_ARRAY_LENGTH15789517
Ref: 4f1515789517
Ref: c-api/intro c Py_EXPORTED_SYMBOL15789980
Ref: 4f1615789980
Ref: c-api/intro c Py_IMPORTED_SYMBOL15790341
Ref: 4f1715790341
Ref: c-api/intro c PyAPI_FUNC15790575
Ref: 4f1815790575
Ref: c-api/intro c PyAPI_DATA15790878
Ref: 4f1915790878
Ref: Useful macros-Footnote-115791232
Ref: Useful macros-Footnote-215791297
Ref: Useful macros-Footnote-315791339
Node: Objects Types and Reference Counts15791381
Ref: c-api/intro api-objects15791513
Ref: 4f1a15791513
Ref: c-api/intro objects-types-and-reference-counts15791513
Ref: 4f1b15791513
Node: Reference Counts<2>15792904
Ref: c-api/intro api-refcounts15793011
Ref: 4f1c15793011
Ref: c-api/intro reference-counts15793011
Ref: 4f1d15793011
Node: Reference Count Details15796953
Ref: c-api/intro api-refcountdetails15797032
Ref: 4f1e15797032
Ref: c-api/intro reference-count-details15797032
Ref: 4f1f15797032
Node: Types<2>15804236
Ref: c-api/intro api-types15804343
Ref: 4f2215804343
Ref: c-api/intro types15804343
Ref: 4f2315804343
Ref: c-api/intro c Py_ssize_t15804797
Ref: c5715804797
Ref: Types<2>-Footnote-115805197
Node: Exceptions<23>15805239
Ref: c-api/intro api-exceptions15805377
Ref: 4f2415805377
Ref: c-api/intro exceptions15805377
Ref: 4f2515805377
Node: Embedding Python<2>15811516
Ref: c-api/intro api-embedding15811636
Ref: 4f2715811636
Ref: c-api/intro embedding-python15811636
Ref: 4f2815811636
Node: Debugging Builds15814846
Ref: c-api/intro api-debugging15814984
Ref: 4f2a15814984
Ref: c-api/intro debugging-builds15814984
Ref: 4f2b15814984
Ref: c-api/intro c Py_DEBUG15815613
Ref: 181c15815613
Node: Recommended third party tools<2>15816711
Ref: c-api/intro c-api-tools15816821
Ref: 4e7715816821
Ref: c-api/intro recommended-third-party-tools15816821
Ref: 4f2c15816821
Ref: Recommended third party tools<2>-Footnote-115818232
Ref: Recommended third party tools<2>-Footnote-215818260
Ref: Recommended third party tools<2>-Footnote-315818296
Ref: Recommended third party tools<2>-Footnote-415818328
Ref: Recommended third party tools<2>-Footnote-515818371
Ref: Recommended third party tools<2>-Footnote-615818405
Ref: Recommended third party tools<2>-Footnote-715818446
Ref: Recommended third party tools<2>-Footnote-815818471
Ref: Recommended third party tools<2>-Footnote-915818500
Node: C API Stability15818573
Ref: c-api/stable doc15818713
Ref: 4f2d15818713
Ref: c-api/stable c-api-stability15818713
Ref: 4f2e15818713
Ref: c-api/stable stable15818713
Ref: 77615818713
Ref: c-api/stable translation-repo15818713
Ref: 4f2f15818713
Ref: C API Stability-Footnote-115820244
Ref: C API Stability-Footnote-215820286
Node: Unstable C API15820341
Ref: c-api/stable id115820451
Ref: 4f3115820451
Ref: c-api/stable unstable-c-api15820451
Ref: 76a15820451
Node: Stable Application Binary Interface15820949
Ref: c-api/stable id215821091
Ref: 4f3215821091
Ref: c-api/stable stable-application-binary-interface15821091
Ref: 4ef015821091
Node: Limited C API15821450
Ref: c-api/stable id315821554
Ref: 4f3315821554
Ref: c-api/stable limited-c-api15821554
Ref: 63715821554
Ref: c-api/stable c Py_LIMITED_API15821837
Ref: 66015821837
Node: Stable ABI15822692
Ref: c-api/stable id415822838
Ref: 4f3415822838
Ref: c-api/stable stable-abi15822838
Ref: 4f3515822838
Ref: Stable ABI-Footnote-115824254
Node: Limited API Scope and Performance15824296
Ref: c-api/stable limited-api-scope-and-performance15824448
Ref: 4f3615824448
Node: Limited API Caveats15825570
Ref: c-api/stable limited-api-caveats15825703
Ref: 4f3815825703
Node: Platform Considerations15827356
Ref: c-api/stable platform-considerations15827507
Ref: 4f3915827507
Ref: c-api/stable stable-abi-platform15827507
Ref: 4f3015827507
Node: Contents of Limited API15828125
Ref: c-api/stable contents-of-limited-api15828232
Ref: 4f3a15828232
Ref: c-api/stable limited-api-list15828232
Ref: 99e15828232
Node: The Very High Level Layer15870803
Ref: c-api/veryhigh doc15870945
Ref: 519515870945
Ref: c-api/veryhigh the-very-high-level-layer15870945
Ref: 519615870945
Ref: c-api/veryhigh translation-repo15870945
Ref: 519715870945
Ref: c-api/veryhigh veryhigh15870945
Ref: 519815870945
Ref: c-api/veryhigh c PyRun_AnyFile15872004
Ref: 519d15872004
Ref: c-api/veryhigh c PyRun_AnyFileFlags15872229
Ref: 519f15872229
Ref: c-api/veryhigh c PyRun_AnyFileEx15872471
Ref: 51a015872471
Ref: c-api/veryhigh c PyRun_AnyFileExFlags15872700
Ref: 519e15872700
Ref: c-api/veryhigh c PyRun_SimpleString15873362
Ref: 4ef415873362
Ref: c-api/veryhigh c PyRun_SimpleStringFlags15873589
Ref: 51a215873589
Ref: c-api/veryhigh c PyRun_SimpleFile15874277
Ref: 4ef515874277
Ref: c-api/veryhigh c PyRun_SimpleFileEx15874508
Ref: 51a315874508
Ref: c-api/veryhigh c PyRun_SimpleFileExFlags15874730
Ref: 1cb215874730
Ref: c-api/veryhigh c PyRun_InteractiveOneObject15875409
Ref: 51a415875409
Ref: c-api/veryhigh c PyRun_InteractiveOne15876123
Ref: 51a515876123
Ref: c-api/veryhigh c PyRun_InteractiveOneFlags15876341
Ref: 51a615876341
Ref: c-api/veryhigh c PyRun_InteractiveLoop15876633
Ref: 51a115876633
Ref: c-api/veryhigh c PyRun_InteractiveLoopFlags15876853
Ref: 51a715876853
Ref: c-api/veryhigh c PyOS_InputHook15877301
Ref: 7a515877301
Ref: c-api/veryhigh c PyOS_ReadlineFunctionPointer15877925
Ref: 7a615877925
Ref: c-api/veryhigh c PyRun_String15879066
Ref: 1da815879066
Ref: c-api/veryhigh c PyRun_StringFlags15879359
Ref: 51a815879359
Ref: c-api/veryhigh c PyRun_File15880063
Ref: 51aa15880063
Ref: c-api/veryhigh c PyRun_FileEx15880398
Ref: 51ac15880398
Ref: c-api/veryhigh c PyRun_FileFlags15880729
Ref: 51ad15880729
Ref: c-api/veryhigh c PyRun_FileExFlags15881073
Ref: 51ab15881073
Ref: c-api/veryhigh c Py_CompileString15881668
Ref: a8715881668
Ref: c-api/veryhigh c Py_CompileStringFlags15881996
Ref: 51ae15881996
Ref: c-api/veryhigh c Py_CompileStringObject15882311
Ref: 51b015882311
Ref: c-api/veryhigh c Py_CompileStringExFlags15883420
Ref: 51af15883420
Ref: c-api/veryhigh c PyEval_EvalCode15883818
Ref: a8815883818
Ref: c-api/veryhigh c PyEval_EvalCodeEx15884203
Ref: 1ac215884203
Ref: c-api/veryhigh c PyEval_EvalFrame15884943
Ref: 4fb315884943
Ref: c-api/veryhigh c PyEval_EvalFrameEx15885252
Ref: 123015885252
Ref: c-api/veryhigh c PyEval_MergeCompilerFlags15886016
Ref: 51b115886016
Ref: c-api/veryhigh c PyCompilerFlags15886208
Ref: c9a15886208
Ref: c-api/veryhigh c PyCompilerFlags cf_flags15886748
Ref: 51b215886748
Ref: c-api/veryhigh c PyCompilerFlags cf_feature_version15886808
Ref: 51b315886808
Ref: c-api/veryhigh c PyCF_ALLOW_TOP_LEVEL_AWAIT15887242
Ref: 51b415887242
Ref: c-api/veryhigh c PyCF_ONLY_AST15887287
Ref: 51b515887287
Ref: c-api/veryhigh c PyCF_OPTIMIZED_AST15887319
Ref: 51b615887319
Ref: c-api/veryhigh c PyCF_TYPE_COMMENTS15887356
Ref: 51b715887356
Node: Available start symbols15887888
Ref: c-api/veryhigh available-start-symbols15887995
Ref: 51ba15887995
Ref: c-api/veryhigh start-symbols15887995
Ref: 51a915887995
Ref: c-api/veryhigh c Py_eval_input15888056
Ref: 519915888056
Ref: c-api/veryhigh c Py_file_input15888214
Ref: 519a15888214
Ref: c-api/veryhigh c Py_single_input15888500
Ref: 519b15888500
Ref: c-api/veryhigh c Py_func_type_input15888726
Ref: 519c15888726
Ref: Available start symbols-Footnote-115889184
Ref: Available start symbols-Footnote-215889226
Node: Stack Effects15889268
Ref: c-api/veryhigh stack-effects15889375
Ref: 51bb15889375
Ref: c-api/veryhigh c PY_INVALID_STACK_EFFECT15889472
Ref: 51bc15889472
Ref: c-api/veryhigh c PyCompile_OpcodeStackEffect15889650
Ref: 51bd15889650
Ref: c-api/veryhigh c PyCompile_OpcodeStackEffectWithJump15889942
Ref: 1e1a15889942
Node: Reference Counting15890472
Ref: c-api/refcounting doc15890617
Ref: 51be15890617
Ref: c-api/refcounting countingrefs15890617
Ref: 51bf15890617
Ref: c-api/refcounting reference-counting15890617
Ref: 51c015890617
Ref: c-api/refcounting translation-repo15890617
Ref: 51c115890617
Ref: c-api/refcounting c Py_REFCNT15890764
Ref: 2cf15890764
Ref: c-api/refcounting c Py_SET_REFCNT15892009
Ref: aaa15892009
Ref: c-api/refcounting c Py_INCREF15892445
Ref: 79015892445
Ref: c-api/refcounting c Py_XINCREF15893336
Ref: c5c15893336
Ref: c-api/refcounting c Py_NewRef15893541
Ref: a9c15893541
Ref: c-api/refcounting c Py_XNewRef15894252
Ref: a9d15894252
Ref: c-api/refcounting c Py_DECREF15894558
Ref: 79115894558
Ref: c-api/refcounting c Py_XDECREF15896188
Ref: 99315896188
Ref: c-api/refcounting c Py_CLEAR15896427
Ref: 79915896427
Ref: c-api/refcounting c Py_IncRef15897263
Ref: 510a15897263
Ref: c-api/refcounting c Py_DecRef15897538
Ref: 510215897538
Ref: c-api/refcounting c Py_SETREF15897801
Ref: 79a15897801
Ref: c-api/refcounting c Py_XSETREF15898560
Ref: 79b15898560
Ref: Reference Counting-Footnote-115898941
Ref: Reference Counting-Footnote-215898983
Node: Exception Handling15899025
Ref: c-api/exceptions doc15899171
Ref: 51c215899171
Ref: c-api/exceptions exception-handling15899171
Ref: 51c315899171
Ref: c-api/exceptions exceptionhandling15899171
Ref: 497015899171
Ref: c-api/exceptions translation-repo15899171
Ref: 51c415899171
Node: Printing and clearing15901474
Ref: c-api/exceptions printing-and-clearing15901577
Ref: 51c515901577
Ref: c-api/exceptions c PyErr_Clear15901634
Ref: 123315901634
Ref: c-api/exceptions c PyErr_PrintEx15901801
Ref: 4fa615901801
Ref: c-api/exceptions c PyErr_Print15902739
Ref: 1d1415902739
Ref: c-api/exceptions c PyErr_WriteUnraisable15902853
Ref: 5f215902853
Ref: c-api/exceptions c PyErr_FormatUnraisable15903841
Ref: 5f115903841
Ref: c-api/exceptions c PyErr_DisplayException15904355
Ref: 43515904355
Node: Raising exceptions15904630
Ref: c-api/exceptions raising-exceptions15904758
Ref: 51c615904758
Ref: c-api/exceptions c PyErr_SetString15904998
Ref: 79d15904998
Ref: c-api/exceptions c PyErr_SetObject15905522
Ref: 79c15905522
Ref: c-api/exceptions c PyErr_Format15905789
Ref: 10b315905789
Ref: c-api/exceptions c PyErr_FormatV15906297
Ref: 10b215906297
Ref: c-api/exceptions c PyErr_SetNone15906672
Ref: 4faf15906672
Ref: c-api/exceptions c PyErr_BadArgument15906835
Ref: 4fa315906835
Ref: c-api/exceptions c PyErr_NoMemory15907130
Ref: 4e8215907130
Ref: c-api/exceptions c PyErr_SetFromErrno15907466
Ref: 4e8115907466
Ref: c-api/exceptions c PyErr_SetFromErrnoWithFilenameObject15908413
Ref: 4fab15908413
Ref: c-api/exceptions c PyErr_SetFromErrnoWithFilenameObjects15908961
Ref: 4fac15908961
Ref: c-api/exceptions c PyErr_SetFromErrnoWithFilename15909438
Ref: 1a6d15909438
Ref: c-api/exceptions c PyErr_SetFromWindowsErr15909834
Ref: 4fad15909834
Ref: c-api/exceptions c PyErr_SetExcFromWindowsErr15910751
Ref: 4fa815910751
Ref: c-api/exceptions c PyErr_SetFromWindowsErrWithFilename15911141
Ref: 1a6f15911141
Ref: c-api/exceptions c PyErr_SetExcFromWindowsErrWithFilenameObject15911787
Ref: 4fa915911787
Ref: c-api/exceptions c PyErr_SetExcFromWindowsErrWithFilenameObjects15912385
Ref: 4faa15912385
Ref: c-api/exceptions c PyErr_SetExcFromWindowsErrWithFilename15912859
Ref: 1a6e15912859
Ref: c-api/exceptions c PyErr_SetImportError15913305
Ref: f3b15913305
Ref: c-api/exceptions c PyErr_SetImportErrorSubclass15913841
Ref: f1415913841
Ref: c-api/exceptions c PyErr_SyntaxLocationObject15914270
Ref: 51c715914270
Ref: c-api/exceptions c PyErr_RangedSyntaxLocationObject15914680
Ref: 51c815914680
Ref: c-api/exceptions c PyErr_SyntaxLocationEx15915029
Ref: 4fb115915029
Ref: c-api/exceptions c PyErr_SyntaxLocation15915387
Ref: 4fb015915387
Ref: c-api/exceptions c PyErr_BadInternalCall15915614
Ref: 4fa415915614
Ref: c-api/exceptions c PyErr_ProgramTextObject15915954
Ref: 51c915915954
Ref: c-api/exceptions c PyErr_ProgramText15916344
Ref: 4fa715916344
Node: Issuing warnings15916701
Ref: c-api/exceptions issuing-warnings15916836
Ref: 51ca15916836
Ref: c-api/exceptions c PyErr_WarnEx15917732
Ref: 165315917732
Ref: c-api/exceptions c PyErr_WarnExplicitObject15918935
Ref: 51cc15918935
Ref: c-api/exceptions c PyErr_WarnExplicit15919479
Ref: 1a7515919479
Ref: c-api/exceptions c PyErr_WarnFormat15919911
Ref: 4fb215919911
Ref: c-api/exceptions c PyErr_WarnExplicitFormat15920270
Ref: 51cd15920270
Ref: c-api/exceptions c PyErr_ResourceWarning15920657
Ref: f1515920657
Node: Querying the error indicator15921039
Ref: c-api/exceptions querying-the-error-indicator15921174
Ref: 51ce15921174
Ref: c-api/exceptions c PyErr_Occurred15921245
Ref: 1c9715921245
Ref: c-api/exceptions c PyErr_ExceptionMatches15922172
Ref: 4f2615922172
Ref: c-api/exceptions c PyErr_GivenExceptionMatches15922495
Ref: 4fa515922495
Ref: c-api/exceptions c PyErr_GetRaisedException15922931
Ref: 42915922931
Ref: c-api/exceptions c PyErr_SetRaisedException15923787
Ref: 42c15923787
Ref: c-api/exceptions c PyErr_Fetch15924158
Ref: 42815924158
Ref: c-api/exceptions c PyErr_Restore15925217
Ref: 42b15925217
Ref: c-api/exceptions c PyErr_NormalizeException15926382
Ref: 42a15926382
Ref: c-api/exceptions c PyErr_GetHandledException15927442
Ref: 97415927442
Ref: c-api/exceptions c PyErr_SetHandledException15928247
Ref: 97515928247
Ref: c-api/exceptions c PyErr_GetExcInfo15928920
Ref: 97715928920
Ref: c-api/exceptions c PyErr_SetExcInfo15929889
Ref: 97615929889
Node: Signal Handling<2>15931071
Ref: c-api/exceptions signal-handling15931207
Ref: 51cf15931207
Ref: c-api/exceptions c PyErr_CheckSignals15931252
Ref: 69415931252
Ref: c-api/exceptions c PyErr_SetInterrupt15932506
Ref: 4fae15932506
Ref: c-api/exceptions c PyErr_SetInterruptEx15932883
Ref: aa015932883
Ref: c-api/exceptions c PySignal_SetWakeupFd15933990
Ref: 15e215933990
Node: Exception Classes15934665
Ref: c-api/exceptions exception-classes15934790
Ref: 51d015934790
Ref: c-api/exceptions c PyErr_NewException15934839
Ref: 147115934839
Ref: c-api/exceptions c PyErr_NewExceptionWithDoc15935853
Ref: 147015935853
Ref: c-api/exceptions c PyExceptionClass_Check15936324
Ref: 51d115936324
Ref: c-api/exceptions c PyExceptionClass_Name15936488
Ref: c5d15936488
Node: Exception Objects15936679
Ref: c-api/exceptions exception-objects15936811
Ref: 51d215936811
Ref: c-api/exceptions c PyExceptionInstance_Check15936860
Ref: 51d315936860
Ref: c-api/exceptions c PyExceptionInstance_Class15937046
Ref: 51d415937046
Ref: c-api/exceptions c PyException_GetTraceback15937135
Ref: 4ff915937135
Ref: c-api/exceptions c PyException_SetTraceback15937537
Ref: 1db615937537
Ref: c-api/exceptions c PyException_GetContext15937759
Ref: 4ff815937759
Ref: c-api/exceptions c PyException_SetContext15938225
Ref: 4ffb15938225
Ref: c-api/exceptions c PyException_GetCause15938562
Ref: 4ff715938562
Ref: c-api/exceptions c PyException_SetCause15938968
Ref: 4ffa15938968
Ref: c-api/exceptions c PyException_GetArgs15939439
Ref: 78c15939439
Ref: c-api/exceptions c PyException_SetArgs15939670
Ref: 78d15939670
Ref: c-api/exceptions c PyUnstable_Exc_PrepReraiseStar15939862
Ref: 51d515939862
Node: Unicode Exception Objects15940805
Ref: c-api/exceptions unicode-exception-objects15940937
Ref: 51d615940937
Ref: c-api/exceptions unicodeexceptions15940937
Ref: 46115940937
Ref: c-api/exceptions c PyUnicodeDecodeError_Create15941084
Ref: 50b515941084
Ref: c-api/exceptions c PyUnicodeDecodeError_GetEncoding15941565
Ref: 50b615941565
Ref: c-api/exceptions c PyUnicodeEncodeError_GetEncoding15941662
Ref: 50be15941662
Ref: c-api/exceptions c PyUnicodeDecodeError_GetObject15941916
Ref: 50b815941916
Ref: c-api/exceptions c PyUnicodeEncodeError_GetObject15942011
Ref: 50bf15942011
Ref: c-api/exceptions c PyUnicodeTranslateError_GetObject15942106
Ref: 50c615942106
Ref: c-api/exceptions c PyUnicodeDecodeError_GetStart15942359
Ref: 50ba15942359
Ref: c-api/exceptions c PyUnicodeEncodeError_GetStart15942454
Ref: 18e615942454
Ref: c-api/exceptions c PyUnicodeTranslateError_GetStart15942549
Ref: 50c815942549
Ref: c-api/exceptions c PyUnicodeDecodeError_SetStart15943107
Ref: 50bd15943107
Ref: c-api/exceptions c PyUnicodeEncodeError_SetStart15943201
Ref: 50c315943201
Ref: c-api/exceptions c PyUnicodeTranslateError_SetStart15943295
Ref: 50cb15943295
Ref: c-api/exceptions c PyUnicodeDecodeError_GetEnd15943731
Ref: 50b715943731
Ref: c-api/exceptions c PyUnicodeEncodeError_GetEnd15943822
Ref: 18e315943822
Ref: c-api/exceptions c PyUnicodeTranslateError_GetEnd15943913
Ref: 50c515943913
Ref: c-api/exceptions c PyUnicodeDecodeError_SetEnd15944384
Ref: 50bb15944384
Ref: c-api/exceptions c PyUnicodeEncodeError_SetEnd15944474
Ref: 50c115944474
Ref: c-api/exceptions c PyUnicodeTranslateError_SetEnd15944564
Ref: 50c915944564
Ref: c-api/exceptions c PyUnicodeDecodeError_GetReason15944893
Ref: 50b915944893
Ref: c-api/exceptions c PyUnicodeEncodeError_GetReason15944988
Ref: 50c015944988
Ref: c-api/exceptions c PyUnicodeTranslateError_GetReason15945083
Ref: 50c715945083
Ref: c-api/exceptions c PyUnicodeDecodeError_SetReason15945336
Ref: 50bc15945336
Ref: c-api/exceptions c PyUnicodeEncodeError_SetReason15945433
Ref: 50c215945433
Ref: c-api/exceptions c PyUnicodeTranslateError_SetReason15945530
Ref: 50ca15945530
Node: Recursion Control15945803
Ref: c-api/exceptions recursion15945945
Ref: 51d715945945
Ref: c-api/exceptions recursion-control15945945
Ref: 51d815945945
Ref: c-api/exceptions c Py_EnterRecursiveCall15946377
Ref: 3d215946377
Ref: c-api/exceptions c Py_LeaveRecursiveCall15947183
Ref: b6d15947183
Ref: c-api/exceptions c Py_ReprEnter15947899
Ref: 510d15947899
Ref: c-api/exceptions c Py_ReprLeave15948704
Ref: 510e15948704
Ref: c-api/exceptions c Py_GetRecursionLimit15948937
Ref: 510815948937
Ref: c-api/exceptions c Py_SetRecursionLimit15949413
Ref: 510f15949413
Node: Exception and warning types15949749
Ref: c-api/exceptions exception-and-warning-types15949876
Ref: 51d915949876
Ref: c-api/exceptions standardexceptions15949876
Ref: 51da15949876
Node: Exception types15950291
Ref: c-api/exceptions exception-types15950394
Ref: 51db15950394
Ref: c-api/exceptions c PyExc_BaseException15950772
Ref: 4fba15950772
Ref: c-api/exceptions c PyExc_BaseExceptionGroup15950952
Ref: 4fbb15950952
Ref: c-api/exceptions c PyExc_Exception15951163
Ref: 4fc915951163
Ref: c-api/exceptions c PyExc_ArithmeticError15951339
Ref: 4fb715951339
Ref: c-api/exceptions c PyExc_AssertionError15951522
Ref: 4fb815951522
Ref: c-api/exceptions c PyExc_AttributeError15951703
Ref: 4fb915951703
Ref: c-api/exceptions c PyExc_BlockingIOError15951884
Ref: 4fbc15951884
Ref: c-api/exceptions c PyExc_BrokenPipeError15952091
Ref: 4fbd15952091
Ref: c-api/exceptions c PyExc_BufferError15952299
Ref: 4fbe15952299
Ref: c-api/exceptions c PyExc_ChildProcessError15952478
Ref: 4fc015952478
Ref: c-api/exceptions c PyExc_ConnectionAbortedError15952688
Ref: 4fc115952688
Ref: c-api/exceptions c PyExc_ConnectionError15952903
Ref: 4fc215952903
Ref: c-api/exceptions c PyExc_ConnectionRefusedError15953111
Ref: 4fc315953111
Ref: c-api/exceptions c PyExc_ConnectionResetError15953326
Ref: 4fc415953326
Ref: c-api/exceptions c PyExc_EOFError15953539
Ref: 4fc615953539
Ref: c-api/exceptions c PyExc_FileExistsError15953715
Ref: 4fca15953715
Ref: c-api/exceptions c PyExc_FileNotFoundError15953923
Ref: 4fcb15953923
Ref: c-api/exceptions c PyExc_FloatingPointError15954132
Ref: 4fcc15954132
Ref: c-api/exceptions c PyExc_GeneratorExit15954318
Ref: 4fce15954318
Ref: c-api/exceptions c PyExc_ImportError15954499
Ref: 4fd015954499
Ref: c-api/exceptions c PyExc_IndentationError15954677
Ref: 4fd215954677
Ref: c-api/exceptions c PyExc_IndexError15954860
Ref: 4fd315954860
Ref: c-api/exceptions c PyExc_InterruptedError15955038
Ref: 4fd415955038
Ref: c-api/exceptions c PyExc_IsADirectoryError15955246
Ref: 4fd515955246
Ref: c-api/exceptions c PyExc_KeyError15955456
Ref: 4fd615955456
Ref: c-api/exceptions c PyExc_KeyboardInterrupt15955631
Ref: 4fd715955631
Ref: c-api/exceptions c PyExc_LookupError15955815
Ref: 4fd815955815
Ref: c-api/exceptions c PyExc_MemoryError15955994
Ref: 4fd915955994
Ref: c-api/exceptions c PyExc_ModuleNotFoundError15956173
Ref: 4fda15956173
Ref: c-api/exceptions c PyExc_NameError15956384
Ref: 4fdb15956384
Ref: c-api/exceptions c PyExc_NotADirectoryError15956560
Ref: 4fdc15956560
Ref: c-api/exceptions c PyExc_NotImplementedError15956771
Ref: 4fdd15956771
Ref: c-api/exceptions c PyExc_OSError15956972
Ref: 4e8415956972
Ref: c-api/exceptions c PyExc_OverflowError15957089
Ref: 4fde15957089
Ref: c-api/exceptions c PyExc_PermissionError15957269
Ref: 4fe015957269
Ref: c-api/exceptions c PyExc_ProcessLookupError15957476
Ref: 4fe115957476
Ref: c-api/exceptions c PyExc_PythonFinalizationError15957687
Ref: 51dc15957687
Ref: c-api/exceptions c PyExc_RecursionError15957835
Ref: 10b415957835
Ref: c-api/exceptions c PyExc_ReferenceError15958041
Ref: 4fe215958041
Ref: c-api/exceptions c PyExc_RuntimeError15958223
Ref: 4fe415958223
Ref: c-api/exceptions c PyExc_StopAsyncIteration15958402
Ref: 4fe615958402
Ref: c-api/exceptions c PyExc_StopIteration15958613
Ref: 4fe715958613
Ref: c-api/exceptions c PyExc_SyntaxError15958793
Ref: 4fe815958793
Ref: c-api/exceptions c PyExc_SystemError15958971
Ref: 4fea15958971
Ref: c-api/exceptions c PyExc_SystemExit15959149
Ref: 4feb15959149
Ref: c-api/exceptions c PyExc_TabError15959326
Ref: 4fec15959326
Ref: c-api/exceptions c PyExc_TimeoutError15959501
Ref: 4fed15959501
Ref: c-api/exceptions c PyExc_TypeError15959705
Ref: 4e8315959705
Ref: c-api/exceptions c PyExc_UnboundLocalError15959881
Ref: 4fee15959881
Ref: c-api/exceptions c PyExc_UnicodeDecodeError15960066
Ref: 4fef15960066
Ref: c-api/exceptions c PyExc_UnicodeEncodeError15960251
Ref: 4ff015960251
Ref: c-api/exceptions c PyExc_UnicodeError15960436
Ref: 4ff115960436
Ref: c-api/exceptions c PyExc_UnicodeTranslateError15960615
Ref: 4ff215960615
Ref: c-api/exceptions c PyExc_ValueError15960804
Ref: 4e8515960804
Ref: c-api/exceptions c PyExc_ZeroDivisionError15960981
Ref: 4e8015960981
Ref: Exception types-Footnote-115962007
Node: OSError aliases15962049
Ref: c-api/exceptions oserror-aliases15962174
Ref: 51dd15962174
Ref: c-api/exceptions c PyExc_EnvironmentError15962746
Ref: 4fc815962746
Ref: c-api/exceptions c PyExc_IOError15962925
Ref: 4fcf15962925
Ref: c-api/exceptions c PyExc_WindowsError15963095
Ref: 4ff615963095
Ref: c-api/exceptions win15963373
Ref: 51de15963373
Node: Warning types15963529
Ref: c-api/exceptions standardwarningcategories15963630
Ref: 51cb15963630
Ref: c-api/exceptions warning-types15963630
Ref: 51df15963630
Ref: c-api/exceptions c PyExc_Warning15964019
Ref: 4ff515964019
Ref: c-api/exceptions c PyExc_BytesWarning15964137
Ref: 4fbf15964137
Ref: c-api/exceptions c PyExc_DeprecationWarning15964316
Ref: 4fc515964316
Ref: c-api/exceptions c PyExc_EncodingWarning15964501
Ref: 4fc715964501
Ref: c-api/exceptions c PyExc_FutureWarning15964710
Ref: 4fcd15964710
Ref: c-api/exceptions c PyExc_ImportWarning15964890
Ref: 4fd115964890
Ref: c-api/exceptions c PyExc_PendingDeprecationWarning15965070
Ref: 4fdf15965070
Ref: c-api/exceptions c PyExc_ResourceWarning15965262
Ref: 4fe315965262
Ref: c-api/exceptions c PyExc_RuntimeWarning15965469
Ref: 4fe515965469
Ref: c-api/exceptions c PyExc_SyntaxWarning15965650
Ref: 4fe915965650
Ref: c-api/exceptions c PyExc_UnicodeWarning15965830
Ref: 4ff315965830
Ref: c-api/exceptions c PyExc_UserWarning15966012
Ref: 4ff415966012
Node: Tracebacks15966271
Ref: c-api/exceptions tracebacks15966372
Ref: 51e015966372
Ref: c-api/exceptions c PyTraceBack_Type15966409
Ref: 50ac15966409
Ref: c-api/exceptions c PyTraceBack_Check15966632
Ref: 51e115966632
Ref: c-api/exceptions c PyTraceBack_Here15966803
Ref: 50aa15966803
Ref: c-api/exceptions c PyTraceBack_Print15967235
Ref: 50ab15967235
Node: Defining extension modules15967502
Ref: c-api/extension-modules doc15967642
Ref: 51e215967642
Ref: c-api/extension-modules defining-extension-modules15967642
Ref: 51e315967642
Ref: c-api/extension-modules extension-modules15967642
Ref: 4ee515967642
Ref: c-api/extension-modules translation-repo15967642
Ref: 51e415967642
Ref: Defining extension modules-Footnote-115969868
Node: Multiple module instances15969910
Ref: c-api/extension-modules multiple-module-instances15970030
Ref: 51e715970030
Node: Initialization function15971503
Ref: c-api/extension-modules extension-export-hook15971658
Ref: 51e515971658
Ref: c-api/extension-modules initialization-function15971658
Ref: 51e915971658
Ref: c-api/extension-modules c PyInit_modulename15971808
Ref: 51ea15971808
Ref: c-api/extension-modules c PyMODINIT_FUNC15972706
Ref: 16da15972706
Ref: Initialization function-Footnote-115973829
Ref: Initialization function-Footnote-215973903
Node: Multi-phase initialization15973945
Ref: c-api/extension-modules id115974109
Ref: 51ec15974109
Ref: c-api/extension-modules multi-phase-initialization15974109
Ref: 51eb15974109
Ref: c-api/extension-modules c PyModuleDef_Init15974443
Ref: 4e8c15974443
Node: Legacy single-phase initialization15975168
Ref: c-api/extension-modules legacy-single-phase-initialization15975300
Ref: 51ee15975300
Ref: c-api/extension-modules single-phase-initialization15975300
Ref: 51e615975300
Ref: Legacy single-phase initialization-Footnote-115977779
Node: Utilities<2>15977914
Ref: c-api/utilities doc15978058
Ref: 51f015978058
Ref: c-api/utilities id115978058
Ref: 51f115978058
Ref: c-api/utilities translation-repo15978058
Ref: 51f215978058
Ref: c-api/utilities utilities15978058
Ref: 51f315978058
Node: Operating System Utilities15978709
Ref: c-api/sys doc15978809
Ref: 51f415978809
Ref: c-api/sys operating-system-utilities15978809
Ref: 51f515978809
Ref: c-api/sys os15978809
Ref: 51f615978809
Ref: c-api/sys c PyOS_FSPath15978876
Ref: f1615978876
Ref: c-api/sys c Py_FdIsInteractive15979520
Ref: 51f715979520
Ref: c-api/sys c PyOS_BeforeFork15980065
Ref: dba15980065
Ref: c-api/sys c PyOS_AfterFork_Parent15980688
Ref: dbb15980688
Ref: c-api/sys c PyOS_AfterFork_Child15981402
Ref: 43015981402
Ref: c-api/sys c PyOS_AfterFork15982402
Ref: 42f15982402
Ref: c-api/sys c PyOS_CheckStack15982886
Ref: 1b8915982886
Ref: c-api/sys c PyOS_sighandler_t15983395
Ref: 505b15983395
Ref: c-api/sys c PyOS_getsig15983489
Ref: 174515983489
Ref: c-api/sys c PyOS_setsig15983774
Ref: 174615983774
Ref: c-api/sys c PyOS_InterruptOccurred15984125
Ref: 1d2a15984125
Ref: c-api/sys c Py_DecodeLocale15984864
Ref: dc215984864
Ref: c-api/sys c Py_EncodeLocale15987202
Ref: dc315987202
Ref: c-api/sys c Py_fopen15988985
Ref: 39315988985
Ref: c-api/sys c Py_fclose15989639
Ref: 39415989639
Ref: Operating System Utilities-Footnote-115990065
Node: System Functions15990107
Ref: c-api/sys system-functions15990231
Ref: 51f915990231
Ref: c-api/sys systemfunctions15990231
Ref: 51fa15990231
Ref: c-api/sys c PySys_GetObject15990530
Ref: 62a15990530
Ref: c-api/sys c PySys_SetObject15990836
Ref: 509715990836
Ref: c-api/sys c PySys_ResetWarnOptions15991137
Ref: 3f415991137
Ref: c-api/sys c PySys_WriteStdout15991501
Ref: 509915991501
Ref: c-api/sys c PySys_WriteStderr15992408
Ref: 509815992408
Ref: c-api/sys c PySys_FormatStdout15992615
Ref: 509515992615
Ref: c-api/sys c PySys_FormatStderr15992930
Ref: 509415992930
Ref: c-api/sys c PySys_GetXOptions15993172
Ref: 509615993172
Ref: c-api/sys c PySys_Audit15993551
Ref: 61315993551
Ref: c-api/sys c PySys_AuditTuple15994891
Ref: 61215994891
Ref: c-api/sys c PySys_AddAuditHook15995229
Ref: 473915995229
Ref: c-api/sys c Py_AuditHookFunction15996875
Ref: 51fb15996875
Ref: System Functions-Footnote-115997380
Node: Process Control15997422
Ref: c-api/sys process-control15997540
Ref: 51fd15997540
Ref: c-api/sys processcontrol15997540
Ref: 51fe15997540
Ref: c-api/sys c Py_FatalError15997585
Ref: b7c15997585
Ref: c-api/sys c Py_Exit15998364
Ref: f4d15998364
Ref: c-api/sys c Py_AtExit15998770
Ref: 510015998770
Node: Importing Modules<2>15999580
Ref: c-api/import doc15999706
Ref: 51ff15999706
Ref: c-api/import importing15999706
Ref: 520015999706
Ref: c-api/import importing-modules15999706
Ref: 520115999706
Ref: c-api/import translation-repo15999706
Ref: 520215999706
Ref: c-api/import c PyImport_ImportModule15999755
Ref: 3dc15999755
Ref: c-api/import c PyImport_ImportModuleNoBlock16000076
Ref: 3db16000076
Ref: c-api/import c PyImport_ImportModuleEx16000761
Ref: 13ad16000761
Ref: c-api/import c PyImport_ImportModuleLevelObject16001520
Ref: 501116001520
Ref: c-api/import c PyImport_ImportModuleLevel16002365
Ref: 13ac16002365
Ref: c-api/import c PyImport_Import16002855
Ref: 160316002855
Ref: c-api/import c PyImport_ReloadModule16003437
Ref: 501216003437
Ref: c-api/import c PyImport_AddModuleRef16003772
Ref: 5fb16003772
Ref: c-api/import c PyImport_AddModuleObject16004780
Ref: 500816004780
Ref: c-api/import c PyImport_AddModule16005167
Ref: 5fc16005167
Ref: c-api/import c PyImport_ExecCodeModule16005450
Ref: 500916005450
Ref: c-api/import c PyImport_ExecCodeModuleEx16007480
Ref: 500a16007480
Ref: c-api/import c PyImport_ExecCodeModuleObject16007926
Ref: 500b16007926
Ref: c-api/import c PyImport_ExecCodeModuleWithPathnames16008591
Ref: 500c16008591
Ref: c-api/import c PyImport_GetMagicNumber16009373
Ref: 13ab16009373
Ref: c-api/import c PyImport_GetMagicTag16009770
Ref: 500d16009770
Ref: c-api/import c PyImport_GetModuleDict16010117
Ref: 500e16010117
Ref: c-api/import c PyImport_GetModule16010425
Ref: dae16010425
Ref: c-api/import c PyImport_GetImporter16010869
Ref: 1a6c16010869
Ref: c-api/import c PyImport_ImportFrozenModuleObject16011605
Ref: 501016011605
Ref: c-api/import c PyImport_ImportFrozenModule16012248
Ref: 500f16012248
Ref: c-api/import c _frozen16012497
Ref: 97a16012497
Ref: c-api/import c PyImport_FrozenModules16013134
Ref: 32fe16013134
Ref: c-api/import c PyImport_AppendInittab16013560
Ref: 1b0416013560
Ref: c-api/import c _inittab16014141
Ref: 520316014141
Ref: c-api/import c _inittab name16014471
Ref: 520416014471
Ref: c-api/import c _inittab initfunc16014564
Ref: 520516014564
Ref: c-api/import c PyImport_ExtendInittab16014710
Ref: 1b0516014710
Ref: c-api/import c PyImport_Inittab16015485
Ref: 1b0316015485
Ref: c-api/import c PyImport_ImportModuleAttr16015747
Ref: 39616015747
Ref: c-api/import c PyImport_ImportModuleAttrString16016317
Ref: 39716016317
Ref: Importing Modules<2>-Footnote-116016695
Node: Data marshalling support16016737
Ref: c-api/marshal doc16016885
Ref: 520616016885
Ref: c-api/marshal data-marshalling-support16016885
Ref: 520716016885
Ref: c-api/marshal marshalling-utils16016885
Ref: 520816016885
Ref: c-api/marshal translation-repo16016885
Ref: 520916016885
Ref: c-api/marshal c Py_MARSHAL_VERSION16017453
Ref: 520a16017453
Ref: c-api/marshal c PyMarshal_WriteLongToFile16017554
Ref: 99a16017554
Ref: c-api/marshal c PyMarshal_WriteObjectToFile16017991
Ref: 99b16017991
Ref: c-api/marshal c PyMarshal_WriteObjectToString16018319
Ref: 99d16018319
Ref: c-api/marshal c PyMarshal_ReadLongFromFile16018667
Ref: 520b16018667
Ref: c-api/marshal c PyMarshal_ReadShortFromFile16019006
Ref: 520c16019006
Ref: c-api/marshal c PyMarshal_ReadObjectFromFile16019348
Ref: 520d16019348
Ref: c-api/marshal c PyMarshal_ReadLastObjectFromFile16019718
Ref: 520e16019718
Ref: c-api/marshal c PyMarshal_ReadObjectFromString16020520
Ref: 99c16020520
Node: Parsing arguments and building values16020950
Ref: c-api/arg doc16021110
Ref: 520f16021110
Ref: c-api/arg arg-parsing16021110
Ref: 3d516021110
Ref: c-api/arg parsing-arguments-and-building-values16021110
Ref: 521016021110
Ref: c-api/arg translation-repo16021110
Ref: 521116021110
Node: Parsing arguments<2>16021781
Ref: c-api/arg parsing-arguments16021899
Ref: 521216021899
Node: Strings and buffers16022616
Ref: c-api/arg arg-parsing-string-and-buffers16022708
Ref: 62c16022708
Ref: c-api/arg strings-and-buffers16022708
Ref: 521316022708
Ref: c-api/arg c-arg-borrowed-buffer16023987
Ref: 3d616023987
Node: Numbers16033332
Ref: c-api/arg numbers16033446
Ref: 521416033446
Node: Other objects16036294
Ref: c-api/arg other-objects16036402
Ref: 521616036402
Ref: c-api/arg o-ampersand16037220
Ref: 521716037220
Ref: c-api/arg c Py_CLEANUP_SUPPORTED16038010
Ref: 521816038010
Node: API Functions16042288
Ref: c-api/arg api-functions16042380
Ref: 521916042380
Ref: c-api/arg c PyArg_ParseTuple16042425
Ref: 3c116042425
Ref: c-api/arg c PyArg_VaParse16042761
Ref: 4f3c16042761
Ref: c-api/arg c PyArg_ParseTupleAndKeywords16043032
Ref: 62416043032
Ref: c-api/arg c PyArg_VaParseTupleAndKeywords16044143
Ref: 62516044143
Ref: c-api/arg c PyArg_ValidateKeywordArguments16044488
Ref: 4f3d16044488
Ref: c-api/arg c PyArg_Parse16044829
Ref: 17f616044829
Ref: c-api/arg c PyArg_UnpackTuple16045510
Ref: 170d16045510
Ref: c-api/arg c PY_CXX_CONST16047491
Ref: 62616047491
Node: Building values16047910
Ref: c-api/arg building-values16048028
Ref: 521a16048028
Ref: c-api/arg c Py_BuildValue16048077
Ref: 3c216048077
Ref: c-api/arg capi-py-buildvalue-format-k16052821
Ref: 185316052821
Ref: c-api/arg c Py_VaBuildValue16056139
Ref: 512216056139
Node: String conversion and formatting16056456
Ref: c-api/conversion doc16056631
Ref: 521b16056631
Ref: c-api/conversion string-conversion16056631
Ref: 521c16056631
Ref: c-api/conversion string-conversion-and-formatting16056631
Ref: 521d16056631
Ref: c-api/conversion translation-repo16056631
Ref: 521e16056631
Ref: c-api/conversion c PyOS_snprintf16056772
Ref: 171016056772
Ref: c-api/conversion c PyOS_vsnprintf16057073
Ref: 171116057073
Ref: c-api/conversion c PyOS_strtoul16058804
Ref: 505d16058804
Ref: c-api/conversion c PyOS_strtol16059833
Ref: 505c16059833
Ref: c-api/conversion c PyOS_string_to_double16060349
Ref: 149d16060349
Ref: c-api/conversion c PyOS_double_to_string16062107
Ref: 505a16062107
Ref: c-api/conversion c Py_DTSF_SIGN16062717
Ref: 521f16062717
Ref: c-api/conversion c Py_DTSF_ADD_DOT_016062859
Ref: 522016062859
Ref: c-api/conversion c Py_DTSF_ALT16062970
Ref: 522116062970
Ref: c-api/conversion c Py_DTSF_NO_NEG_016063153
Ref: 522216063153
Ref: c-api/conversion c Py_DTST_FINITE16063770
Ref: 522316063770
Ref: c-api/conversion c Py_DTST_INFINITE16063968
Ref: 522416063968
Ref: c-api/conversion c Py_DTST_NAN16064161
Ref: 522516064161
Ref: c-api/conversion c PyOS_mystricmp16064515
Ref: 1d2316064515
Ref: c-api/conversion c PyOS_mystrnicmp16064587
Ref: 1d2216064587
Ref: c-api/conversion c PyOS_stricmp16065378
Ref: 522616065378
Ref: c-api/conversion c PyOS_strnicmp16065448
Ref: 522716065448
Ref: String conversion and formatting-Footnote-116065855
Ref: String conversion and formatting-Footnote-216065903
Ref: String conversion and formatting-Footnote-316065952
Ref: String conversion and formatting-Footnote-416065999
Node: Character classification and conversion16066045
Ref: c-api/conversion character-classification-and-conversion16066193
Ref: 522816066193
Ref: c-api/conversion c Py_ISALNUM16066471
Ref: 155916066471
Ref: c-api/conversion c Py_ISALPHA16066569
Ref: 155a16066569
Ref: c-api/conversion c Py_ISDIGIT16066696
Ref: 155b16066696
Ref: c-api/conversion c Py_ISLOWER16066796
Ref: 155c16066796
Ref: c-api/conversion c Py_ISUPPER16066910
Ref: 155e16066910
Ref: c-api/conversion c Py_ISSPACE16067025
Ref: 155d16067025
Ref: c-api/conversion c Py_ISXDIGIT16067192
Ref: 155f16067192
Ref: c-api/conversion c Py_TOLOWER16067328
Ref: 156016067328
Ref: c-api/conversion c Py_TOUPPER16067417
Ref: 156116067417
Node: PyHash API16067506
Ref: c-api/hash doc16067632
Ref: 522916067632
Ref: c-api/hash pyhash-api16067632
Ref: 522a16067632
Ref: c-api/hash translation-repo16067632
Ref: 522b16067632
Ref: c-api/hash c Py_hash_t16067765
Ref: 146b16067765
Ref: c-api/hash c Py_uhash_t16067860
Ref: 522c16067860
Ref: c-api/hash c Py_HASH_ALGORITHM16067958
Ref: 522d16067958
Ref: c-api/hash c Py_HASH_FNV16068229
Ref: 522e16068229
Ref: c-api/hash c Py_HASH_SIPHASH2416068254
Ref: 522f16068254
Ref: c-api/hash c Py_HASH_SIPHASH1316068285
Ref: 523016068285
Ref: c-api/hash c Py_HASH_CUTOFF16068685
Ref: 523116068685
Ref: c-api/hash c PyHASH_MODULUS16069372
Ref: 19d016069372
Ref: c-api/hash c PyHASH_BITS16069587
Ref: 19d116069587
Ref: c-api/hash c PyHASH_MULTIPLIER16069711
Ref: 197c16069711
Ref: c-api/hash c PyHASH_INF16069836
Ref: 19d216069836
Ref: c-api/hash c PyHASH_IMAG16070016
Ref: 19d316070016
Ref: c-api/hash c PyHash_FuncDef16070213
Ref: 523216070213
Ref: c-api/hash c PyHash_FuncDef hash16070318
Ref: 523416070318
Ref: c-api/hash c PyHash_FuncDef name16070453
Ref: 523516070453
Ref: c-api/hash c PyHash_FuncDef hash_bits16070636
Ref: 523616070636
Ref: c-api/hash c PyHash_FuncDef seed_bits16070820
Ref: 523716070820
Ref: c-api/hash c PyHash_GetFuncDef16071019
Ref: 523316071019
Ref: c-api/hash c Py_HashPointer16071255
Ref: 42516071255
Ref: c-api/hash c Py_HashBuffer16071564
Ref: 39516071564
Ref: c-api/hash c PyObject_GenericHash16072206
Ref: 60c16072206
Ref: PyHash API-Footnote-116072638
Ref: PyHash API-Footnote-216072691
Node: Reflection16072733
Ref: c-api/reflection doc16072856
Ref: 523816072856
Ref: c-api/reflection id116072856
Ref: 523916072856
Ref: c-api/reflection reflection16072856
Ref: 523a16072856
Ref: c-api/reflection translation-repo16072856
Ref: 523b16072856
Ref: c-api/reflection c PyEval_GetBuiltins16072893
Ref: 5f416072893
Ref: c-api/reflection c PyEval_GetLocals16073309
Ref: 5f816073309
Ref: c-api/reflection c PyEval_GetGlobals16074875
Ref: 5f616074875
Ref: c-api/reflection c PyEval_GetFrame16075267
Ref: 1b2116075267
Ref: c-api/reflection c PyEval_GetFrameBuiltins16075604
Ref: 5f316075604
Ref: c-api/reflection c PyEval_GetFrameLocals16075965
Ref: 5f716075965
Ref: c-api/reflection c PyEval_GetFrameGlobals16076600
Ref: 5f516076600
Ref: c-api/reflection c PyEval_GetFuncName16077010
Ref: 4fb516077010
Ref: c-api/reflection c PyEval_GetFuncDesc16077232
Ref: 4fb416077232
Ref: Reflection-Footnote-116077675
Node: Codec registry and support functions16077717
Ref: c-api/codec doc16077842
Ref: 523c16077842
Ref: c-api/codec codec-registry16077842
Ref: f3216077842
Ref: c-api/codec codec-registry-and-support-functions16077842
Ref: 523d16077842
Ref: c-api/codec translation-repo16077842
Ref: 523e16077842
Ref: c-api/codec c PyCodec_Register16077931
Ref: 4f7e16077931
Ref: c-api/codec c PyCodec_Unregister16078252
Ref: a9916078252
Ref: c-api/codec c PyCodec_KnownEncoding16078616
Ref: 4f7c16078616
Ref: c-api/codec c PyCodec_Encode16078867
Ref: 3e216078867
Ref: c-api/codec c PyCodec_Decode16079411
Ref: 3e116079411
Node: Codec lookup API16080067
Ref: c-api/codec codec-lookup-api16080213
Ref: 523f16080213
Ref: c-api/codec c PyCodec_Encoder16080533
Ref: 4f7816080533
Ref: c-api/codec c PyCodec_Decoder16080759
Ref: 4f7716080759
Ref: c-api/codec c PyCodec_IncrementalEncoder16080984
Ref: 4f7b16080984
Ref: c-api/codec c PyCodec_IncrementalDecoder16081268
Ref: 4f7a16081268
Ref: c-api/codec c PyCodec_StreamReader16081552
Ref: 4f8116081552
Ref: c-api/codec c PyCodec_StreamWriter16081851
Ref: 4f8216081851
Node: Registry API for Unicode encoding error handlers16082150
Ref: c-api/codec registry-api-for-unicode-encoding-error-handlers16082328
Ref: 524016082328
Ref: c-api/codec c PyCodec_RegisterError16082445
Ref: 4f7f16082445
Ref: c-api/codec c PyCodec_LookupError16083573
Ref: 4f7d16083573
Ref: c-api/codec c PyCodec_StrictErrors16083953
Ref: 4f8316083953
Ref: c-api/codec c PyCodec_IgnoreErrors16084149
Ref: 4f7916084149
Ref: c-api/codec c PyCodec_ReplaceErrors16084381
Ref: 4f8016084381
Ref: c-api/codec c PyCodec_XMLCharRefReplaceErrors16084624
Ref: 4f8416084624
Ref: c-api/codec c PyCodec_BackslashReplaceErrors16084878
Ref: 4f7616084878
Ref: c-api/codec c PyCodec_NameReplaceErrors16085158
Ref: 10b116085158
Node: Codec utility variables16085451
Ref: c-api/codec codec-utility-variables16085604
Ref: 524116085604
Ref: c-api/codec c Py_hexdigits16085671
Ref: 524216085671
Node: PyTime C API16085842
Ref: c-api/time doc16085978
Ref: 48416085978
Ref: c-api/time c-api-time16085978
Ref: 5d216085978
Ref: c-api/time pytime-c-api16085978
Ref: 524316085978
Ref: c-api/time translation-repo16085978
Ref: 524416085978
Node: Types<3>16086333
Ref: c-api/time types16086414
Ref: 524616086414
Ref: c-api/time c PyTime_t16086445
Ref: 5d316086445
Ref: c-api/time c PyTime_MIN16086970
Ref: 5d416086970
Ref: c-api/time c PyTime_MAX16087064
Ref: 5d516087064
Node: Clock Functions16087158
Ref: c-api/time clock-functions16087267
Ref: 524716087267
Ref: c-api/time c PyTime_Monotonic16087993
Ref: 5d716087993
Ref: c-api/time c PyTime_PerfCounter16088158
Ref: 5d916088158
Ref: c-api/time c PyTime_Time16088332
Ref: 5db16088332
Node: Raw Clock Functions16088493
Ref: c-api/time raw-clock-functions16088614
Ref: 524816088614
Ref: c-api/time c PyTime_MonotonicRaw16089162
Ref: 5d816089162
Ref: c-api/time c PyTime_PerfCounterRaw16089376
Ref: 5da16089376
Ref: c-api/time c PyTime_TimeRaw16089594
Ref: 5dc16089594
Node: Conversion functions16089793
Ref: c-api/time conversion-functions16089890
Ref: 524916089890
Ref: c-api/time c PyTime_AsSecondsDouble16089951
Ref: 5d616089951
Node: Support for Perf Maps16090172
Ref: c-api/perfmaps doc16090263
Ref: 524a16090263
Ref: c-api/perfmaps perfmaps16090263
Ref: 524b16090263
Ref: c-api/perfmaps support-for-perf-maps16090263
Ref: 524c16090263
Ref: c-api/perfmaps translation-repo16090263
Ref: 524d16090263
Ref: c-api/perfmaps c PyUnstable_PerfMapState_Init16090938
Ref: 1a9216090938
Ref: c-api/perfmaps c PyUnstable_WritePerfMapEntry16091798
Ref: 1a9116091798
Ref: c-api/perfmaps c PyUnstable_PerfMapState_Fini16092611
Ref: 1a9316092611
Ref: Support for Perf Maps-Footnote-116093193
Ref: Support for Perf Maps-Footnote-216093250
Node: Abstract Objects Layer16093374
Ref: c-api/abstract doc16093514
Ref: 524e16093514
Ref: c-api/abstract abstract16093514
Ref: 4edc16093514
Ref: c-api/abstract abstract-objects-layer16093514
Ref: 524f16093514
Ref: c-api/abstract translation-repo16093514
Ref: 525016093514
Node: Object Protocol16094219
Ref: c-api/object doc16094315
Ref: 525116094315
Ref: c-api/object object16094315
Ref: 525216094315
Ref: c-api/object object-protocol16094315
Ref: 525316094315
Ref: c-api/object c Py_GetConstant16094360
Ref: 5f916094360
Ref: c-api/object c Py_CONSTANT_NONE16095030
Ref: 525416095030
Ref: c-api/object c Py_CONSTANT_FALSE16095234
Ref: 525516095234
Ref: c-api/object c Py_CONSTANT_TRUE16095437
Ref: 525616095437
Ref: c-api/object c Py_CONSTANT_ELLIPSIS16095644
Ref: 525716095644
Ref: c-api/object c Py_CONSTANT_NOT_IMPLEMENTED16095859
Ref: 525816095859
Ref: c-api/object c Py_CONSTANT_ZERO16096061
Ref: 525916096061
Ref: c-api/object c Py_CONSTANT_ONE16096254
Ref: 525a16096254
Ref: c-api/object c Py_CONSTANT_EMPTY_STR16096454
Ref: 525b16096454
Ref: c-api/object c Py_CONSTANT_EMPTY_BYTES16096651
Ref: 525c16096651
Ref: c-api/object c Py_CONSTANT_EMPTY_TUPLE16096847
Ref: 525d16096847
Ref: c-api/object c Py_GetConstantBorrowed16097185
Ref: 5fa16097185
Ref: c-api/object c Py_NotImplemented16097719
Ref: 525e16097719
Ref: c-api/object c Py_RETURN_NOTIMPLEMENTED16097908
Ref: 17cf16097908
Ref: c-api/object c Py_PRINT_RAW16098143
Ref: 525f16098143
Ref: c-api/object c PyObject_Print16098431
Ref: 197316098431
Ref: c-api/object c PyObject_HasAttrWithError16098813
Ref: 61b16098813
Ref: c-api/object c PyObject_HasAttrStringWithError16099194
Ref: 61d16099194
Ref: c-api/object c PyObject_HasAttr16099573
Ref: 61c16099573
Ref: c-api/object c PyObject_HasAttrString16100221
Ref: 61e16100221
Ref: c-api/object c PyObject_GetAttr16100965
Ref: 5ee16100965
Ref: c-api/object c PyObject_GetAttrString16101487
Ref: 5ef16101487
Ref: c-api/object c PyObject_GetOptionalAttr16101994
Ref: 5ec16101994
Ref: c-api/object c PyObject_GetOptionalAttrString16102714
Ref: 5ed16102714
Ref: c-api/object c PyObject_GenericGetAttr16103113
Ref: 506616103113
Ref: c-api/object c PyObject_SetAttr16103799
Ref: 506f16103799
Ref: c-api/object c PyObject_SetAttrString16104383
Ref: 197616104383
Ref: c-api/object c PyObject_GenericSetAttr16105313
Ref: 506716105313
Ref: c-api/object c PyObject_DelAttr16106013
Ref: 181916106013
Ref: c-api/object c PyObject_DelAttrString16106318
Ref: 181a16106318
Ref: c-api/object c PyObject_GenericGetDict16107120
Ref: 1ced16107120
Ref: c-api/object c PyObject_GenericSetDict16107876
Ref: 506816107876
Ref: c-api/object c _PyObject_GetDictPtr16108216
Ref: 526016108216
Ref: c-api/object c PyObject_RichCompare16108644
Ref: 4eda16108644
Ref: c-api/object c PyObject_RichCompareBool16109378
Ref: 1d7416109378
Ref: c-api/object c PyObject_Format16109916
Ref: 506516109916
Ref: c-api/object c PyObject_Repr16110357
Ref: 123116110357
Ref: c-api/object c PyObject_ASCII16110926
Ref: 505e16110926
Ref: c-api/object c PyObject_Str16111477
Ref: 123216111477
Ref: c-api/object c PyObject_Bytes16112094
Ref: 506016112094
Ref: c-api/object c PyObject_IsSubclass16112588
Ref: 10a916112588
Ref: c-api/object c PyObject_IsInstance16113619
Ref: 10a816113619
Ref: c-api/object c PyObject_Hash16114640
Ref: 43616114640
Ref: c-api/object c PyObject_HashNotImplemented16115051
Ref: 15ce16115051
Ref: c-api/object c PyObject_IsTrue16115475
Ref: 506b16115475
Ref: c-api/object c PyObject_Not16115754
Ref: 506d16115754
Ref: c-api/object c PyObject_Type16116026
Ref: 507116116026
Ref: c-api/object c PyObject_TypeCheck16116739
Ref: 1c9d16116739
Ref: c-api/object c PyObject_Size16116964
Ref: 507016116964
Ref: c-api/object c PyObject_Length16117031
Ref: 506c16117031
Ref: c-api/object c PyObject_LengthHint16117397
Ref: 120616117397
Ref: c-api/object c PyObject_GetItem16117859
Ref: 5ea16117859
Ref: c-api/object c PyObject_SetItem16118197
Ref: 4f2016118197
Ref: c-api/object c PyObject_DelItem16118581
Ref: 506216118581
Ref: c-api/object c PyObject_DelItemString16118853
Ref: 506316118853
Ref: c-api/object c PyObject_Dir16119148
Ref: 506416119148
Ref: c-api/object c PyObject_GetIter16119748
Ref: 506a16119748
Ref: c-api/object c PyObject_SelfIter16120183
Ref: 506e16120183
Ref: c-api/object c PyObject_GetAIter16120535
Ref: 506916120535
Ref: c-api/object c PyObject_GetTypeData16121102
Ref: 76c16121102
Ref: c-api/object c PyType_GetTypeDataSize16121574
Ref: 76d16121574
Ref: c-api/object c PyObject_GetItemData16122255
Ref: 76f16122255
Ref: c-api/object c PyObject_VisitManagedDict16122598
Ref: 60d16122598
Ref: c-api/object c PyObject_ClearManagedDict16122913
Ref: 60e16122913
Ref: c-api/object c PyUnstable_Object_EnableDeferredRefcount16123188
Ref: 3c516123188
Ref: c-api/object c PyUnstable_Object_IsUniqueReferencedTemporary16124723
Ref: 3c716124723
Ref: c-api/object c PyUnstable_IsImmortal16126300
Ref: 3c416126300
Ref: c-api/object c PyUnstable_TryIncRef16126828
Ref: 18b116126828
Ref: c-api/object c PyUnstable_EnableTryIncRef16129516
Ref: 18b216129516
Ref: c-api/object c PyUnstable_Object_IsUniquelyReferenced16129975
Ref: 3c616129975
Ref: Object Protocol-Footnote-116130966
Ref: Object Protocol-Footnote-216131008
Ref: Object Protocol-Footnote-316131050
Node: Call Protocol16131120
Ref: c-api/call doc16131240
Ref: 526816131240
Ref: c-api/call call16131240
Ref: 7a416131240
Ref: c-api/call call-protocol16131240
Ref: 526916131240
Ref: c-api/call translation-repo16131240
Ref: 526a16131240
Node: The tp_call Protocol16131465
Ref: c-api/call the-tp-call-protocol16131567
Ref: 526b16131567
Node: The Vectorcall Protocol16132303
Ref: c-api/call the-vectorcall-protocol16132432
Ref: 526d16132432
Ref: c-api/call vectorcall16132432
Ref: 77516132432
Ref: c-api/call c vectorcallfunc16134218
Ref: 77a16134218
Ref: c-api/call c PY_VECTORCALL_ARGUMENTS_OFFSET16135300
Ref: 78116135300
Ref: The Vectorcall Protocol-Footnote-116136436
Node: Recursion Control<2>16136478
Ref: c-api/call recursion-control16136589
Ref: 526f16136589
Node: Vectorcall Support API16137001
Ref: c-api/call vectorcall-support-api16137112
Ref: 527016137112
Ref: c-api/call c PyVectorcall_NARGS16137175
Ref: 77816137175
Ref: c-api/call c PyVectorcall_Function16137636
Ref: 527116137636
Ref: c-api/call c PyVectorcall_Call16138185
Ref: 77916138185
Node: Object Calling API16138798
Ref: c-api/call capi-call16138923
Ref: 526c16138923
Ref: c-api/call object-calling-api16138923
Ref: 527216138923
Ref: c-api/call c PyObject_Call16143551
Ref: 63d16143551
Ref: c-api/call c PyObject_CallNoArgs16144247
Ref: 63c16144247
Ref: c-api/call c PyObject_CallOneArg16144738
Ref: b7116144738
Ref: c-api/call c PyObject_CallObject16145140
Ref: 4e9516145140
Ref: c-api/call c PyObject_CallFunction16145667
Ref: 63f16145667
Ref: c-api/call c PyObject_CallMethod16146536
Ref: 64016146536
Ref: c-api/call c PyObject_CallFunctionObjArgs16147474
Ref: 506116147474
Ref: c-api/call c PyObject_CallMethodObjArgs16148058
Ref: 1dc716148058
Ref: c-api/call c PyObject_CallMethodNoArgs16148656
Ref: 527316148656
Ref: c-api/call c PyObject_CallMethodOneArg16149047
Ref: 527416149047
Ref: c-api/call c _PyObject_Vectorcall16149475
Ref: 527616149475
Ref: c-api/call c PyObject_Vectorcall16149475
Ref: 77f16149475
Ref: c-api/call c PyObject_VectorcallDict16150259
Ref: 527516150259
Ref: c-api/call c PyObject_VectorcallMethod16150971
Ref: 78016150971
Node: Call Support API16152093
Ref: c-api/call call-support-api16152186
Ref: 527716152186
Ref: c-api/call c PyCallable_Check16152237
Ref: 4f6a16152237
Node: Number Protocol16152480
Ref: c-api/number doc16152602
Ref: 527816152602
Ref: c-api/number number16152602
Ref: 527916152602
Ref: c-api/number number-protocol16152602
Ref: 527a16152602
Ref: c-api/number translation-repo16152602
Ref: 527b16152602
Ref: c-api/number c PyNumber_Check16152647
Ref: c5e16152647
Ref: c-api/number c PyNumber_Add16152949
Ref: 503d16152949
Ref: c-api/number c PyNumber_Subtract16153272
Ref: 505716153272
Ref: c-api/number c PyNumber_Multiply16153606
Ref: 505016153606
Ref: c-api/number c PyNumber_MatrixMultiply16153939
Ref: 10b816153939
Ref: c-api/number c PyNumber_FloorDivide16154339
Ref: 504116154339
Ref: c-api/number c PyNumber_TrueDivide16154669
Ref: 505816154669
Ref: c-api/number c PyNumber_Remainder16155289
Ref: 505516155289
Ref: c-api/number c PyNumber_Divmod16155622
Ref: 504016155622
Ref: c-api/number c PyNumber_Power16155969
Ref: 505416155969
Ref: c-api/number c PyNumber_Negative16156495
Ref: 505116156495
Ref: c-api/number c PyNumber_Positive16156784
Ref: 505316156784
Ref: c-api/number c PyNumber_Absolute16157057
Ref: 503c16157057
Ref: c-api/number c PyNumber_Invert16157350
Ref: 504e16157350
Ref: c-api/number c PyNumber_Lshift16157650
Ref: 504f16157650
Ref: c-api/number c PyNumber_Rshift16157994
Ref: 505616157994
Ref: c-api/number c PyNumber_And16158339
Ref: 503e16158339
Ref: c-api/number c PyNumber_Xor16158675
Ref: 505916158675
Ref: c-api/number c PyNumber_Or16159019
Ref: 505216159019
Ref: c-api/number c PyNumber_InPlaceAdd16159353
Ref: 504216159353
Ref: c-api/number c PyNumber_InPlaceSubtract16159745
Ref: 504b16159745
Ref: c-api/number c PyNumber_InPlaceMultiply16160148
Ref: 504616160148
Ref: c-api/number c PyNumber_InPlaceMatrixMultiply16160550
Ref: 10b916160550
Ref: c-api/number c PyNumber_InPlaceFloorDivide16161019
Ref: 504416161019
Ref: c-api/number c PyNumber_InPlaceTrueDivide16161433
Ref: 504c16161433
Ref: c-api/number c PyNumber_InPlaceRemainder16162122
Ref: 504916162122
Ref: c-api/number c PyNumber_InPlacePower16162524
Ref: 504816162524
Ref: c-api/number c PyNumber_InPlaceLshift16163182
Ref: 504516163182
Ref: c-api/number c PyNumber_InPlaceRshift16163595
Ref: 504a16163595
Ref: c-api/number c PyNumber_InPlaceAnd16164009
Ref: 504316164009
Ref: c-api/number c PyNumber_InPlaceXor16164414
Ref: 504d16164414
Ref: c-api/number c PyNumber_InPlaceOr16164827
Ref: 504716164827
Ref: c-api/number c PyNumber_Long16165230
Ref: c5f16165230
Ref: c-api/number c PyNumber_Float16165548
Ref: c6016165548
Ref: c-api/number c PyNumber_Index16165866
Ref: a9516165866
Ref: c-api/number c PyNumber_ToBase16166332
Ref: 1b5b16166332
Ref: c-api/number c PyNumber_AsSsize_t16166865
Ref: 503f16166865
Ref: c-api/number c PyIndex_Check16167673
Ref: b8316167673
Node: Sequence Protocol16167975
Ref: c-api/sequence doc16168100
Ref: 527c16168100
Ref: c-api/sequence sequence16168100
Ref: 527d16168100
Ref: c-api/sequence sequence-protocol16168100
Ref: 527e16168100
Ref: c-api/sequence translation-repo16168100
Ref: 527f16168100
Ref: c-api/sequence c PySequence_Check16168149
Ref: 507816168149
Ref: c-api/sequence c PySequence_Size16168605
Ref: 1e1b16168605
Ref: c-api/sequence c PySequence_Length16168674
Ref: 508016168674
Ref: c-api/sequence c PySequence_Concat16168941
Ref: 507916168941
Ref: c-api/sequence c PySequence_Repeat16169280
Ref: 508216169280
Ref: c-api/sequence c PySequence_InPlaceConcat16169635
Ref: 507d16169635
Ref: c-api/sequence c PySequence_InPlaceRepeat16170044
Ref: 507e16170044
Ref: c-api/sequence c PySequence_GetItem16170468
Ref: 1e1c16170468
Ref: c-api/sequence c PySequence_GetSlice16170777
Ref: 507c16170777
Ref: c-api/sequence c PySequence_SetItem16171142
Ref: 1e1d16171142
Ref: c-api/sequence c PySequence_DelItem16171679
Ref: 1e1e16171679
Ref: c-api/sequence c PySequence_SetSlice16171934
Ref: 508316171934
Ref: c-api/sequence c PySequence_DelSlice16172249
Ref: 507b16172249
Ref: c-api/sequence c PySequence_Count16172554
Ref: 507a16172554
Ref: c-api/sequence c PySequence_Contains16172927
Ref: 3d916172927
Ref: c-api/sequence c PySequence_In16173265
Ref: 3d816173265
Ref: c-api/sequence c PySequence_Index16173557
Ref: 507f16173557
Ref: c-api/sequence c PySequence_List16173861
Ref: 508116173861
Ref: c-api/sequence c PySequence_Tuple16174240
Ref: 508416174240
Ref: c-api/sequence c PySequence_Fast16174711
Ref: 188a16174711
Ref: c-api/sequence c PySequence_Fast_GET_SIZE16175463
Ref: 3ca16175463
Ref: c-api/sequence c PySequence_Fast_GET_ITEM16175883
Ref: 3cb16175883
Ref: c-api/sequence c PySequence_Fast_ITEMS16176210
Ref: 3cc16176210
Ref: c-api/sequence c PySequence_ITEM16176636
Ref: 528116176636
Node: Mapping Protocol16177021
Ref: c-api/mapping doc16177148
Ref: 528216177148
Ref: c-api/mapping mapping16177148
Ref: 528316177148
Ref: c-api/mapping mapping-protocol16177148
Ref: 528416177148
Ref: c-api/mapping translation-repo16177148
Ref: 528516177148
Ref: c-api/mapping c PyMapping_Check16177304
Ref: 502916177304
Ref: c-api/mapping c PyMapping_Size16177733
Ref: 1e1f16177733
Ref: c-api/mapping c PyMapping_Length16177801
Ref: 502a16177801
Ref: c-api/mapping c PyMapping_GetItemString16178062
Ref: 5eb16178062
Ref: c-api/mapping c PyMapping_GetOptionalItem16178420
Ref: 5e816178420
Ref: c-api/mapping c PyMapping_GetOptionalItemString16179103
Ref: 5e916179103
Ref: c-api/mapping c PyMapping_SetItemString16179491
Ref: 502b16179491
Ref: c-api/mapping c PyMapping_DelItem16179800
Ref: 528616179800
Ref: c-api/mapping c PyMapping_DelItemString16179926
Ref: 528716179926
Ref: c-api/mapping c PyMapping_HasKeyWithError16180185
Ref: 61f16180185
Ref: c-api/mapping c PyMapping_HasKeyStringWithError16180547
Ref: 62116180547
Ref: c-api/mapping c PyMapping_HasKey16180914
Ref: 62016180914
Ref: c-api/mapping c PyMapping_HasKeyString16181515
Ref: 62216181515
Ref: c-api/mapping c PyMapping_Keys16182202
Ref: db716182202
Ref: c-api/mapping c PyMapping_Values16182541
Ref: db816182541
Ref: c-api/mapping c PyMapping_Items16182884
Ref: db916182884
Node: Iterator Protocol16183286
Ref: c-api/iter doc16183411
Ref: 528816183411
Ref: c-api/iter iterator16183411
Ref: 528916183411
Ref: c-api/iter iterator-protocol16183411
Ref: 528a16183411
Ref: c-api/iter translation-repo16183411
Ref: 528b16183411
Ref: c-api/iter c PyIter_Check16183526
Ref: 1c9a16183526
Ref: c-api/iter c PyAIter_Check16183795
Ref: 4f3b16183795
Ref: c-api/iter c PyIter_NextItem16184079
Ref: 39816184079
Ref: c-api/iter c PyIter_Next16184533
Ref: 39916184533
Ref: c-api/iter c PySendResult16185193
Ref: 528c16185193
Ref: c-api/iter c PyIter_Send16185344
Ref: a9a16185344
Node: Buffer Protocol16185929
Ref: c-api/buffer doc16186029
Ref: 528d16186029
Ref: c-api/buffer buffer-protocol16186029
Ref: 528e16186029
Ref: c-api/buffer bufferobjects16186029
Ref: 26016186029
Ref: c-api/buffer translation-repo16186029
Ref: 528f16186029
Node: Buffer structure16188794
Ref: c-api/buffer buffer-structure16188891
Ref: 529116188891
Ref: c-api/buffer id116188891
Ref: 529216188891
Ref: c-api/buffer c Py_buffer16189964
Ref: 95d16189964
Ref: c-api/buffer c Py_buffer buf16190083
Ref: 529416190083
Ref: c-api/buffer c Py_buffer obj16190545
Ref: 529616190545
Ref: c-api/buffer c Py_buffer len16191182
Ref: 529716191182
Ref: c-api/buffer c Py_buffer readonly16191794
Ref: 529816191794
Ref: c-api/buffer c Py_buffer itemsize16191964
Ref: 529916191964
Ref: c-api/buffer c Py_buffer format16192893
Ref: 529a16192893
Ref: c-api/buffer c Py_buffer ndim16193215
Ref: 529c16193215
Ref: c-api/buffer c Py_buffer shape16193639
Ref: 529b16193639
Ref: c-api/buffer c Py_buffer strides16194204
Ref: 529516194204
Ref: c-api/buffer c Py_buffer suboffsets16194742
Ref: 529d16194742
Ref: c-api/buffer c Py_buffer internal16195646
Ref: 529f16195646
Ref: c-api/buffer c PyBUF_MAX_NDIM16196033
Ref: 4f4516196033
Node: Buffer request types16196363
Ref: c-api/buffer buffer-request-types16196483
Ref: 4a4616196483
Ref: c-api/buffer id216196483
Ref: 52a016196483
Node: request-independent fields16197091
Ref: c-api/buffer request-independent-fields16197198
Ref: 52a116197198
Node: readonly format16197466
Ref: c-api/buffer readonly-format16197606
Ref: 52a216197606
Ref: c-api/buffer c PyBUF_WRITABLE16197657
Ref: 15bd16197657
Ref: c-api/buffer c PyBUF_WRITEABLE16198196
Ref: 52a316198196
Ref: c-api/buffer c PyBUF_FORMAT16198327
Ref: 4f4116198327
Node: shape strides suboffsets16199030
Ref: c-api/buffer shape-strides-suboffsets16199163
Ref: 52a416199163
Ref: c-api/buffer c PyBUF_INDIRECT16199700
Ref: 4f4416199700
Ref: c-api/buffer c PyBUF_STRIDES16199887
Ref: 4f4c16199887
Ref: c-api/buffer c PyBUF_ND16200065
Ref: 4f4616200065
Ref: c-api/buffer c PyBUF_SIMPLE16200252
Ref: 4f4916200252
Node: contiguity requests16200410
Ref: c-api/buffer contiguity-requests16200545
Ref: 52a516200545
Ref: c-api/buffer c PyBUF_C_CONTIGUOUS16201154
Ref: 15be16201154
Ref: c-api/buffer c PyBUF_F_CONTIGUOUS16201380
Ref: 15bf16201380
Ref: c-api/buffer c PyBUF_ANY_CONTIGUOUS16201608
Ref: 4f3e16201608
Node: compound requests16201976
Ref: c-api/buffer compound-requests16202078
Ref: 52a616202078
Ref: c-api/buffer c PyBUF_FULL16202952
Ref: 4f4216202952
Ref: c-api/buffer c PyBUF_FULL_RO16203231
Ref: 4f4316203231
Ref: c-api/buffer c PyBUF_RECORDS16203507
Ref: 4f4716203507
Ref: c-api/buffer c PyBUF_RECORDS_RO16203786
Ref: 4f4816203786
Ref: c-api/buffer c PyBUF_STRIDED16204059
Ref: 4f4a16204059
Ref: c-api/buffer c PyBUF_STRIDED_RO16204339
Ref: 4f4b16204339
Ref: c-api/buffer c PyBUF_CONTIG16204612
Ref: 4f3f16204612
Ref: c-api/buffer c PyBUF_CONTIG_RO16204892
Ref: 4f4016204892
Node: Complex arrays16205141
Ref: c-api/buffer complex-arrays16205269
Ref: 529e16205269
Node: NumPy-style shape and strides16205475
Ref: c-api/buffer numpy-style-shape-and-strides16205602
Ref: 52a716205602
Node: PIL-style shape strides and suboffsets16207482
Ref: c-api/buffer pil-style-shape-strides-and-suboffsets16207609
Ref: 52a816207609
Node: Buffer-related functions16208835
Ref: c-api/buffer buffer-related-functions16208934
Ref: 52a916208934
Ref: c-api/buffer c PyObject_CheckBuffer16209003
Ref: 63916209003
Ref: c-api/buffer c PyObject_GetBuffer16209347
Ref: 63a16209347
Ref: c-api/buffer c PyBuffer_Release16210357
Ref: 63b16210357
Ref: c-api/buffer c PyBuffer_SizeFromFormat16210886
Ref: 95f16210886
Ref: c-api/buffer c PyBuffer_IsContiguous16211194
Ref: 96316211194
Ref: c-api/buffer c PyBuffer_GetPointer16211613
Ref: 95e16211613
Ref: c-api/buffer c PyBuffer_FromContiguous16211926
Ref: 96116211926
Ref: c-api/buffer c PyBuffer_ToContiguous16212309
Ref: 96016212309
Ref: c-api/buffer c PyObject_CopyData16212787
Ref: 96216212787
Ref: c-api/buffer c PyBuffer_FillContiguousStrides16213087
Ref: 96416213087
Ref: c-api/buffer c PyBuffer_FillInfo16213538
Ref: 96516213538
Node: Concrete Objects Layer16214568
Ref: c-api/concrete doc16214735
Ref: 52aa16214735
Ref: c-api/concrete concrete16214735
Ref: 52ab16214735
Ref: c-api/concrete concrete-objects-layer16214735
Ref: 52ac16214735
Ref: c-api/concrete translation-repo16214735
Ref: 52ad16214735
Node: Fundamental Objects16215756
Ref: c-api/concrete fundamental16215858
Ref: 52af16215858
Ref: c-api/concrete fundamental-objects16215858
Ref: 52b016215858
Node: Type Objects16216039
Ref: c-api/type doc16216131
Ref: 52b116216131
Ref: c-api/type type-objects16216131
Ref: 52b216216131
Ref: c-api/type typeobjects16216131
Ref: 52b316216131
Ref: c-api/type c PyTypeObject16216174
Ref: c9e16216174
Ref: c-api/type c PyType_Type16216345
Ref: 77016216345
Ref: c-api/type c PyType_Check16216558
Ref: 1d6f16216558
Ref: c-api/type c PyType_CheckExact16216804
Ref: 1d7016216804
Ref: c-api/type c PyType_ClearCache16217033
Ref: 50b216217033
Ref: c-api/type c PyType_GetFlags16217198
Ref: 1d2516217198
Ref: c-api/type c PyType_GetDict16217747
Ref: 1a7316217747
Ref: c-api/type c PyType_Modified16218490
Ref: 1b6316218490
Ref: c-api/type c PyType_AddWatcher16218789
Ref: 78616218789
Ref: c-api/type c PyType_ClearWatcher16219307
Ref: 52b416219307
Ref: c-api/type c PyType_Watch16219778
Ref: 78716219778
Ref: c-api/type c PyType_Unwatch16220481
Ref: 52b516220481
Ref: c-api/type c PyType_WatchCallback16220993
Ref: 52b616220993
Ref: c-api/type c PyType_HasFeature16221348
Ref: 1d2416221348
Ref: c-api/type c PyType_FastSubclass16221543
Ref: 52b716221543
Ref: c-api/type c PyType_IS_GC16222043
Ref: 52b916222043
Ref: c-api/type c PyType_IsSubtype16222234
Ref: 50b316222234
Ref: c-api/type c PyType_GenericAlloc16222637
Ref: c6316222637
Ref: c-api/type c PyType_GenericNew16223881
Ref: 4eb516223881
Ref: c-api/type c PyType_Ready16224269
Ref: 98116224269
Ref: c-api/type c PyType_GetName16225163
Ref: 95916225163
Ref: c-api/type c PyType_GetQualName16225485
Ref: 95a16225485
Ref: c-api/type c PyType_GetFullyQualifiedName16225831
Ref: 61616225831
Ref: c-api/type c PyType_GetModuleName16226262
Ref: 61816226262
Ref: c-api/type c PyType_GetSlot16226555
Ref: a9e16226555
Ref: c-api/type c PyType_GetModule16227260
Ref: b6816227260
Ref: c-api/type c PyType_GetModuleState16228212
Ref: b6916228212
Ref: c-api/type c PyType_GetModuleByDef16228804
Ref: 63516228804
Ref: c-api/type c PyType_GetBaseByToken16229808
Ref: 3b016229808
Ref: c-api/type c PyUnstable_Type_AssignVersionTag16230628
Ref: 52bc16230628
Ref: c-api/type c PyType_SUPPORTS_WEAKREFS16231127
Ref: 52bd16231127
Node: Creating Heap-Allocated Types16231514
Ref: c-api/type creating-heap-allocated-types16231592
Ref: 52be16231592
Ref: c-api/type c PyType_FromMetaclass16231748
Ref: 77316231748
Ref: c-api/type c PyType_FromModuleAndSpec16233932
Ref: 77416233932
Ref: c-api/type c PyType_FromSpecWithBases16234933
Ref: 79f16234933
Ref: c-api/type c PyType_FromSpec16235767
Ref: 79e16235767
Ref: c-api/type c PyType_Freeze16236556
Ref: 3af16236556
Ref: c-api/type c PyType_Spec16237080
Ref: 1a7116237080
Ref: c-api/type c PyType_Spec name16237223
Ref: 52bf16237223
Ref: c-api/type c PyType_Spec basicsize16237345
Ref: 76b16237345
Ref: c-api/type c PyType_Spec itemsize16238116
Ref: 52c016238116
Ref: c-api/type c PyType_Spec flags16239239
Ref: 52c116239239
Ref: c-api/type c PyType_Spec slots16239481
Ref: 52c216239481
Ref: c-api/type c PyType_Slot16239713
Ref: 50b416239713
Ref: c-api/type c PyType_Slot slot16239916
Ref: 52ba16239916
Ref: c-api/type c PyType_Slot pfunc16242461
Ref: 52cb16242461
Ref: c-api/type c Py_tp_token16242852
Ref: 3b116242852
Ref: c-api/type c Py_TP_USE_SPEC16243943
Ref: 511116243943
Node: The None Object16244227
Ref: c-api/none doc16244319
Ref: 52cc16244319
Ref: c-api/none noneobject16244319
Ref: 52cd16244319
Ref: c-api/none the-none-object16244319
Ref: 52ce16244319
Ref: c-api/none translation-repo16244319
Ref: 52cf16244319
Ref: c-api/none c Py_None16244638
Ref: 4e8816244638
Ref: c-api/none c Py_RETURN_NONE16244893
Ref: 167a16244893
Node: Numeric Objects16244973
Ref: c-api/concrete numeric-objects16245100
Ref: 52d016245100
Ref: c-api/concrete numericobjects16245100
Ref: 52d116245100
Node: Integer Objects16245249
Ref: c-api/long doc16245340
Ref: 52d216245340
Ref: c-api/long integer-objects16245340
Ref: 52d316245340
Ref: c-api/long longobjects16245340
Ref: 52d416245340
Ref: c-api/long c PyLongObject16245630
Ref: 39e16245630
Ref: c-api/long c PyLong_Type16245815
Ref: 502716245815
Ref: c-api/long c PyLong_Check16246066
Ref: 52d516246066
Ref: c-api/long c PyLong_CheckExact16246256
Ref: 52d616246256
Ref: c-api/long c PyLong_FromLong16246456
Ref: 1bb816246456
Ref: c-api/long c PyLong_FromUnsignedLong16246954
Ref: 18a516246954
Ref: c-api/long c PyLong_FromSsize_t16247233
Ref: 188616247233
Ref: c-api/long c PyLong_FromSize_t16247502
Ref: 18a716247502
Ref: c-api/long c PyLong_FromLongLong16247757
Ref: 1bb916247757
Ref: c-api/long c PyLong_FromInt3216248014
Ref: 3a316248014
Ref: c-api/long c PyLong_FromInt6416248085
Ref: 3a416248085
Ref: c-api/long c PyLong_FromUnsignedLongLong16248389
Ref: 18a616248389
Ref: c-api/long c PyLong_FromUInt3216248682
Ref: 3a516248682
Ref: c-api/long c PyLong_FromUInt6416248755
Ref: 3a616248755
Ref: c-api/long c PyLong_FromDouble16249066
Ref: b3e16249066
Ref: c-api/long c PyLong_FromString16249328
Ref: 502416249328
Ref: c-api/long c PyLong_FromUnicodeObject16250629
Ref: ab916250629
Ref: c-api/long c PyLong_FromVoidPtr16250888
Ref: 502516250888
Ref: c-api/long c PyLong_FromNativeBytes16251199
Ref: 60716251199
Ref: c-api/long c PyLong_FromUnsignedNativeBytes16251937
Ref: 60816251937
Ref: c-api/long c PyLong_FromPid16252540
Ref: 52d716252540
Ref: c-api/long c PyLong_AsLong16252842
Ref: 60516252842
Ref: c-api/long c PyLong_AS_LONG16253519
Ref: 52d816253519
Ref: c-api/long c PyLong_AsInt16253869
Ref: 60416253869
Ref: c-api/long c PyLong_AsLongAndOverflow16254114
Ref: 146e16254114
Ref: c-api/long c PyLong_AsLongLong16255034
Ref: 501e16255034
Ref: c-api/long c PyLong_AsLongLongAndOverflow16255730
Ref: 146d16255730
Ref: c-api/long c PyLong_AsSsize_t16256694
Ref: 502016256694
Ref: c-api/long c PyLong_AsUnsignedLong16257155
Ref: 502116257155
Ref: c-api/long c PyLong_AsSize_t16257601
Ref: 501f16257601
Ref: c-api/long c PyLong_AsUnsignedLongLong16258025
Ref: 149c16258025
Ref: c-api/long c PyLong_AsUnsignedLongMask16258629
Ref: 502216258629
Ref: c-api/long c PyLong_AsUnsignedLongLongMask16259387
Ref: 1db216259387
Ref: c-api/long c PyLong_AsInt3216260180
Ref: 39f16260180
Ref: c-api/long c PyLong_AsInt6416260247
Ref: 3a016260247
Ref: c-api/long c PyLong_AsUInt3216260882
Ref: 3a116260882
Ref: c-api/long c PyLong_AsUInt6416260951
Ref: 3a216260951
Ref: c-api/long c PyLong_AsDouble16261672
Ref: 195d16261672
Ref: c-api/long c PyLong_AsVoidPtr16262078
Ref: 502316262078
Ref: c-api/long c PyLong_AsNativeBytes16262539
Ref: 60616262539
Ref: c-api/long c Py_ASNATIVEBYTES_DEFAULTS16266753
Ref: 50fb16266753
Ref: c-api/long c Py_ASNATIVEBYTES_BIG_ENDIAN16266902
Ref: 50fa16266902
Ref: c-api/long c Py_ASNATIVEBYTES_LITTLE_ENDIAN16267051
Ref: 50fc16267051
Ref: c-api/long c Py_ASNATIVEBYTES_NATIVE_ENDIAN16267197
Ref: 50fd16267197
Ref: c-api/long c Py_ASNATIVEBYTES_UNSIGNED_BUFFER16267345
Ref: 50ff16267345
Ref: c-api/long c Py_ASNATIVEBYTES_REJECT_NEGATIVE16267491
Ref: 50fe16267491
Ref: c-api/long c Py_ASNATIVEBYTES_ALLOW_INDEX16267633
Ref: 50f916267633
Ref: c-api/long c PyLong_AsPid16269603
Ref: 19b716269603
Ref: c-api/long c PyLong_GetSign16269929
Ref: 39a16269929
Ref: c-api/long c PyLong_IsPositive16270347
Ref: 39b16270347
Ref: c-api/long c PyLong_IsNegative16270687
Ref: 39c16270687
Ref: c-api/long c PyLong_IsZero16271027
Ref: 39d16271027
Ref: c-api/long c PyLong_GetInfo16271339
Ref: 502616271339
Ref: c-api/long c PyUnstable_Long_IsCompact16271746
Ref: 7a716271746
Ref: c-api/long c PyUnstable_Long_CompactValue16272565
Ref: 7a816272565
Node: Export API16273112
Ref: c-api/long export-api16273199
Ref: 52d916273199
Ref: c-api/long c PyLongLayout16273262
Ref: 52da16273262
Ref: c-api/long c PyLongLayout bits_per_digit16273717
Ref: 52db16273717
Ref: c-api/long c PyLongLayout digit_size16273879
Ref: 52dc16273879
Ref: c-api/long c PyLongLayout digits_order16274020
Ref: 52dd16274020
Ref: c-api/long c PyLongLayout digit_endianness16274201
Ref: 52de16274201
Ref: c-api/long c PyLong_GetNativeLayout16274417
Ref: 3a716274417
Ref: c-api/long c PyLongExport16274886
Ref: 52df16274886
Ref: c-api/long c PyLongExport value16275239
Ref: 52e116275239
Ref: c-api/long c PyLongExport negative16275409
Ref: 52e216275409
Ref: c-api/long c PyLongExport ndigits16275575
Ref: 52e316275575
Ref: c-api/long c PyLongExport digits16275748
Ref: 52e016275748
Ref: c-api/long c PyLong_Export16275854
Ref: 3a816275854
Ref: c-api/long c PyLong_FreeExport16276495
Ref: 3a916276495
Node: PyLongWriter API16276801
Ref: c-api/long pylongwriter-api16276911
Ref: 52e416276911
Ref: c-api/long c PyLongWriter16277055
Ref: 52e516277055
Ref: c-api/long c PyLongWriter_Create16277255
Ref: 3aa16277255
Ref: c-api/long c PyLongWriter_Finish16278379
Ref: 3ab16278379
Ref: c-api/long c PyLongWriter_Discard16278915
Ref: 3ac16278915
Node: Deprecated API16279215
Ref: c-api/long deprecated-api16279306
Ref: 52e616279306
Ref: c-api/long c PyLong_SHIFT16279794
Ref: 52e716279794
Ref: c-api/long c PyLong_BASE16279936
Ref: 1be816279936
Ref: c-api/long c PyLong_MASK16280031
Ref: 52e816280031
Node: Boolean Objects16280137
Ref: c-api/bool doc16280259
Ref: 52e916280259
Ref: c-api/bool boolean-objects16280259
Ref: 52ea16280259
Ref: c-api/bool boolobjects16280259
Ref: 52eb16280259
Ref: c-api/bool translation-repo16280259
Ref: 52ec16280259
Ref: c-api/bool c PyBool_Type16280574
Ref: 4f4f16280574
Ref: c-api/bool c PyBool_Check16280823
Ref: 52ef16280823
Ref: c-api/bool c Py_False16280969
Ref: 52ed16280969
Ref: c-api/bool c Py_True16281203
Ref: 52ee16281203
Ref: c-api/bool c Py_RETURN_FALSE16281434
Ref: 167c16281434
Ref: c-api/bool c Py_RETURN_TRUE16281516
Ref: 167b16281516
Ref: c-api/bool c PyBool_FromLong16281596
Ref: 4f4e16281596
Node: Floating-Point Objects16281843
Ref: c-api/float doc16281972
Ref: 52f016281972
Ref: c-api/float floating-point-objects16281972
Ref: 52f116281972
Ref: c-api/float floatobjects16281972
Ref: 52f216281972
Ref: c-api/float translation-repo16281972
Ref: 52f316281972
Ref: c-api/float c PyFloatObject16282035
Ref: 52f416282035
Ref: c-api/float c PyFloat_Type16282158
Ref: 500316282158
Ref: c-api/float c PyFloat_Check16282419
Ref: 52f516282419
Ref: c-api/float c PyFloat_CheckExact16282619
Ref: 52f616282619
Ref: c-api/float c PyFloat_FromString16282829
Ref: 500216282829
Ref: c-api/float c PyFloat_FromDouble16283101
Ref: 500116283101
Ref: c-api/float c PyFloat_AsDouble16283342
Ref: c6116283342
Ref: c-api/float c PyFloat_AS_DOUBLE16283987
Ref: 52f716283987
Ref: c-api/float c PyFloat_GetInfo16284151
Ref: 15f716284151
Ref: c-api/float c PyFloat_GetMax16284487
Ref: 15f516284487
Ref: c-api/float c PyFloat_GetMin16284646
Ref: 15f616284646
Ref: c-api/float c Py_INFINITY16284804
Ref: 52f816284804
Ref: c-api/float c Py_NAN16285062
Ref: 52f916285062
Ref: c-api/float c Py_HUGE_VAL16285322
Ref: 52fa16285322
Ref: c-api/float c Py_MATH_E16285467
Ref: 52fb16285467
Ref: c-api/float c Py_MATH_El16285583
Ref: 52fc16285583
Ref: c-api/float c Py_MATH_PI16285682
Ref: 52fd16285682
Ref: c-api/float c Py_MATH_PIl16285800
Ref: 52fe16285800
Ref: c-api/float c Py_MATH_TAU16285906
Ref: 52ff16285906
Ref: c-api/float c Py_RETURN_NAN16286054
Ref: 530016286054
Ref: c-api/float c Py_RETURN_INF16286223
Ref: 530116286223
Ref: c-api/float c Py_IS_FINITE16286498
Ref: 530216286498
Ref: c-api/float c Py_IS_INFINITY16286815
Ref: 530316286815
Ref: c-api/float c Py_IS_NAN16287083
Ref: 167d16287083
Node: Pack and Unpack functions16287383
Ref: c-api/float pack-and-unpack-functions16287467
Ref: 530416287467
Node: Pack functions16288905
Ref: c-api/float pack-functions16289006
Ref: 530516289006
Ref: c-api/float c PyFloat_Pack216289780
Ref: 96a16289780
Ref: c-api/float c PyFloat_Pack416289913
Ref: 96b16289913
Ref: c-api/float c PyFloat_Pack816290048
Ref: 96c16290048
Node: Unpack functions16290183
Ref: c-api/float unpack-functions16290284
Ref: 530616290284
Ref: c-api/float c PyFloat_Unpack216291035
Ref: 96d16291035
Ref: c-api/float c PyFloat_Unpack416291171
Ref: 96e16291171
Ref: c-api/float c PyFloat_Unpack816291309
Ref: 96f16291309
Node: Complex Number Objects16291447
Ref: c-api/complex doc16291552
Ref: 530716291552
Ref: c-api/complex complex-number-objects16291552
Ref: 530816291552
Ref: c-api/complex complexobjects16291552
Ref: 530916291552
Ref: c-api/complex translation-repo16291552
Ref: 530a16291552
Node: Complex Numbers as C Structures16291987
Ref: c-api/complex complex-numbers-as-c-structures16292119
Ref: 530b16292119
Ref: c-api/complex c Py_complex16292404
Ref: 521516292404
Ref: c-api/complex c Py_complex real16292678
Ref: 530c16292678
Ref: c-api/complex c Py_complex imag16292709
Ref: 530d16292709
Ref: c-api/complex c _Py_c_sum16292882
Ref: 530e16292882
Ref: c-api/complex c _Py_c_diff16293081
Ref: 530f16293081
Ref: c-api/complex c _Py_c_neg16293293
Ref: 531016293293
Ref: c-api/complex c _Py_c_prod16293473
Ref: 531116293473
Ref: c-api/complex c _Py_c_quot16293677
Ref: 531216293677
Ref: c-api/complex c _Py_c_pow16293982
Ref: 18da16293982
Node: Complex Numbers as Python Objects16294366
Ref: c-api/complex complex-numbers-as-python-objects16294498
Ref: 531316294498
Ref: c-api/complex c PyComplexObject16294585
Ref: 531416294585
Ref: c-api/complex c PyComplex_Type16294710
Ref: 4f8616294710
Ref: c-api/complex c PyComplex_Check16294973
Ref: 531516294973
Ref: c-api/complex c PyComplex_CheckExact16295179
Ref: 531616295179
Ref: c-api/complex c PyComplex_FromCComplex16295395
Ref: 531716295395
Ref: c-api/complex c PyComplex_FromDoubles16295670
Ref: 4f8516295670
Ref: c-api/complex c PyComplex_RealAsDouble16295990
Ref: 19fa16295990
Ref: c-api/complex c PyComplex_ImagAsDouble16296699
Ref: 19fb16296699
Ref: c-api/complex c PyComplex_AsCComplex16297423
Ref: 15f816297423
Node: Sequence Objects16298257
Ref: c-api/concrete sequence-objects16298382
Ref: 531816298382
Ref: c-api/concrete sequenceobjects16298382
Ref: 531916298382
Node: Bytes Objects16298760
Ref: c-api/bytes doc16298853
Ref: 531a16298853
Ref: c-api/bytes bytes-objects16298853
Ref: 531b16298853
Ref: c-api/bytes bytesobjects16298853
Ref: 531c16298853
Ref: c-api/bytes c PyBytesObject16299015
Ref: 99616299015
Ref: c-api/bytes c PyBytes_Type16299129
Ref: 4f6016299129
Ref: c-api/bytes c PyBytes_Check16299378
Ref: 15a716299378
Ref: c-api/bytes c PyBytes_CheckExact16299565
Ref: 531d16299565
Ref: c-api/bytes c PyBytes_FromString16299768
Ref: 4f5d16299768
Ref: c-api/bytes c PyBytes_FromStringAndSize16300111
Ref: 15a816300111
Ref: c-api/bytes c PyBytes_FromFormat16300516
Ref: 1df316300516
Ref: c-api/bytes c PyBytes_FromFormatV16304436
Ref: 4f5b16304436
Ref: c-api/bytes c PyBytes_FromObject16304725
Ref: 4f5c16304725
Ref: c-api/bytes c PyBytes_Size16304973
Ref: 4f5f16304973
Ref: c-api/bytes c PyBytes_GET_SIZE16305140
Ref: 531e16305140
Ref: c-api/bytes c PyBytes_AsString16305284
Ref: a8916305284
Ref: c-api/bytes c PyBytes_AS_STRING16305933
Ref: 531f16305933
Ref: c-api/bytes c PyBytes_AsStringAndSize16306074
Ref: 4f5716306074
Ref: c-api/bytes c PyBytes_Concat16307152
Ref: 4f5816307152
Ref: c-api/bytes c PyBytes_ConcatAndDel16307687
Ref: 4f5916307687
Ref: c-api/bytes c PyBytes_Join16308040
Ref: 38316308040
Ref: c-api/bytes c _PyBytes_Resize16308686
Ref: 19b616308686
Ref: c-api/bytes c PyBytes_Repr16309417
Ref: 4f5e16309417
Ref: c-api/bytes c PyBytes_DecodeEscape16310353
Ref: 4f5a16310353
Ref: Bytes Objects-Footnote-116311187
Ref: Bytes Objects-Footnote-216311313
Ref: Bytes Objects-Footnote-316311439
Ref: Bytes Objects-Footnote-416311565
Ref: Bytes Objects-Footnote-516311691
Ref: Bytes Objects-Footnote-616311817
Ref: Bytes Objects-Footnote-716311943
Ref: Bytes Objects-Footnote-816312069
Node: Byte Array Objects16312195
Ref: c-api/bytearray doc16312323
Ref: 532016312323
Ref: c-api/bytearray byte-array-objects16312323
Ref: 532116312323
Ref: c-api/bytearray bytearrayobjects16312323
Ref: 532216312323
Ref: c-api/bytearray translation-repo16312323
Ref: 532316312323
Ref: c-api/bytearray c PyByteArrayObject16312378
Ref: 532416312378
Ref: c-api/bytearray c PyByteArray_Type16312500
Ref: 4f5516312500
Node: Type check macros16312829
Ref: c-api/bytearray type-check-macros16312930
Ref: 532516312930
Ref: c-api/bytearray c PyByteArray_Check16312983
Ref: 532616312983
Ref: c-api/bytearray c PyByteArray_CheckExact16313182
Ref: 532716313182
Node: Direct API functions16313397
Ref: c-api/bytearray direct-api-functions16313513
Ref: 532816313513
Ref: c-api/bytearray c PyByteArray_FromObject16313572
Ref: 15b016313572
Ref: c-api/bytearray c PyByteArray_FromStringAndSize16313910
Ref: 15b116313910
Ref: c-api/bytearray c PyByteArray_Concat16314245
Ref: 4f5216314245
Ref: c-api/bytearray c PyByteArray_Size16314566
Ref: 4f5416314566
Ref: c-api/bytearray c PyByteArray_AsString16314775
Ref: 4f5116314775
Ref: c-api/bytearray c PyByteArray_Resize16315045
Ref: 4f5316315045
Node: Macros16315408
Ref: c-api/bytearray macros16315498
Ref: 532916315498
Ref: c-api/bytearray c PyByteArray_AS_STRING16315599
Ref: 532a16315599
Ref: c-api/bytearray c PyByteArray_GET_SIZE16315752
Ref: 532b16315752
Node: Unicode Objects and Codecs16315927
Ref: c-api/unicode doc16316055
Ref: 13a816316055
Ref: c-api/unicode translation-repo16316055
Ref: 532c16316055
Ref: c-api/unicode unicode-objects-and-codecs16316055
Ref: 532d16316055
Ref: c-api/unicode unicodeobjects16316055
Ref: 532e16316055
Node: Unicode Objects16316264
Ref: c-api/unicode unicode-objects16316366
Ref: 532f16316366
Ref: Unicode Objects-Footnote-116317239
Ref: Unicode Objects-Footnote-216317281
Node: Unicode Type16317323
Ref: c-api/unicode unicode-type16317424
Ref: 533016317424
Ref: c-api/unicode c PyUnicode_Type16317556
Ref: 50f316317556
Ref: c-api/unicode c PyUnicodeIter_Type16317794
Ref: 50c416317794
Ref: c-api/unicode c Py_UCS416318048
Ref: 33d16318048
Ref: c-api/unicode c Py_UCS216318073
Ref: 137c16318073
Ref: c-api/unicode c Py_UCS116318098
Ref: 137b16318098
Ref: c-api/unicode c PyASCIIObject16318412
Ref: 137d16318412
Ref: c-api/unicode c PyCompactUnicodeObject16318443
Ref: 137e16318443
Ref: c-api/unicode c PyUnicodeObject16318483
Ref: 99816318483
Ref: c-api/unicode c PyUnicode_IS_COMPACT16319001
Ref: 533116319001
Ref: c-api/unicode c PyUnicode_IS_COMPACT_ASCII16319167
Ref: 533216319167
Ref: c-api/unicode c PyUnicode_Check16319456
Ref: 533316319456
Ref: c-api/unicode c PyUnicode_CheckExact16319641
Ref: 533416319641
Ref: c-api/unicode c PyUnicode_GET_LENGTH16319829
Ref: ab316319829
Ref: c-api/unicode c PyUnicode_1BYTE_DATA16320110
Ref: 138216320110
Ref: c-api/unicode c PyUnicode_2BYTE_DATA16320199
Ref: 138316320199
Ref: c-api/unicode c PyUnicode_4BYTE_DATA16320288
Ref: 138416320288
Ref: c-api/unicode c PyUnicode_1BYTE_KIND16320703
Ref: 138616320703
Ref: c-api/unicode c PyUnicode_2BYTE_KIND16320737
Ref: 138716320737
Ref: c-api/unicode c PyUnicode_4BYTE_KIND16320771
Ref: 138816320771
Ref: c-api/unicode c PyUnicode_KIND16320984
Ref: 138516320984
Ref: c-api/unicode c PyUnicode_DATA16321320
Ref: 138116321320
Ref: c-api/unicode c PyUnicode_WRITE16321560
Ref: 138b16321560
Ref: c-api/unicode c PyUnicode_READ16322218
Ref: 138916322218
Ref: c-api/unicode c PyUnicode_READ_CHAR16322513
Ref: 138a16322513
Ref: c-api/unicode c PyUnicode_MAX_CHAR_VALUE16322860
Ref: 138c16322860
Ref: c-api/unicode c PyUnicode_IsIdentifier16323231
Ref: 1d6e16323231
Ref: c-api/unicode c PyUnicode_IS_ASCII16323654
Ref: 533516323654
Node: Unicode Character Properties16323860
Ref: c-api/unicode unicode-character-properties16324008
Ref: 533616324008
Ref: c-api/unicode c Py_UNICODE_ISSPACE16324272
Ref: 1cad16324272
Ref: c-api/unicode c Py_UNICODE_ISLOWER16324415
Ref: 533716324415
Ref: c-api/unicode c Py_UNICODE_ISUPPER16324557
Ref: 533816324557
Ref: c-api/unicode c Py_UNICODE_ISTITLE16324700
Ref: 533916324700
Ref: c-api/unicode c Py_UNICODE_ISLINEBREAK16324842
Ref: 533a16324842
Ref: c-api/unicode c Py_UNICODE_ISDECIMAL16324988
Ref: 533b16324988
Ref: c-api/unicode c Py_UNICODE_ISDIGIT16325125
Ref: 533c16325125
Ref: c-api/unicode c Py_UNICODE_ISNUMERIC16325258
Ref: 533d16325258
Ref: c-api/unicode c Py_UNICODE_ISALPHA16325395
Ref: 533e16325395
Ref: c-api/unicode c Py_UNICODE_ISALNUM16325539
Ref: 533f16325539
Ref: c-api/unicode c Py_UNICODE_ISPRINTABLE16325685
Ref: 534016325685
Ref: c-api/unicode c Py_UNICODE_TOLOWER16325940
Ref: 534116325940
Ref: c-api/unicode c Py_UNICODE_TOUPPER16326066
Ref: 534216326066
Ref: c-api/unicode c Py_UNICODE_TOTITLE16326192
Ref: 534316326192
Ref: c-api/unicode c Py_UNICODE_TODECIMAL16326318
Ref: 534416326318
Ref: c-api/unicode c Py_UNICODE_TODIGIT16326539
Ref: 534516326539
Ref: c-api/unicode c Py_UNICODE_TONUMERIC16326754
Ref: 534616326754
Ref: c-api/unicode c Py_UNICODE_IS_SURROGATE16327007
Ref: 534716327007
Ref: c-api/unicode c Py_UNICODE_IS_HIGH_SURROGATE16327132
Ref: 534816327132
Ref: c-api/unicode c Py_UNICODE_IS_LOW_SURROGATE16327267
Ref: 534916327267
Ref: c-api/unicode c Py_UNICODE_HIGH_SURROGATE16327400
Ref: 534a16327400
Ref: c-api/unicode c Py_UNICODE_LOW_SURROGATE16327626
Ref: 534b16327626
Ref: c-api/unicode c Py_UNICODE_JOIN_SURROGATES16327850
Ref: 534c16327850
Node: Creating and accessing Unicode strings16328255
Ref: c-api/unicode creating-and-accessing-unicode-strings16328406
Ref: 534d16328406
Ref: c-api/unicode c PyUnicode_New16328590
Ref: aab16328590
Ref: c-api/unicode c PyUnicode_FromKindAndData16330035
Ref: 137f16330035
Ref: c-api/unicode c PyUnicode_FromStringAndSize16330851
Ref: 50eb16330851
Ref: c-api/unicode c PyUnicode_FromString16331533
Ref: 50ea16331533
Ref: c-api/unicode c PyUnicode_FromFormat16331794
Ref: 62b16331794
Ref: c-api/unicode c PyUnicode_FromFormatV16344789
Ref: 79516344789
Ref: c-api/unicode c PyUnicode_FromObject16345081
Ref: 50e816345081
Ref: c-api/unicode c PyUnicode_FromOrdinal16345557
Ref: 50e916345557
Ref: c-api/unicode c PyUnicode_FromEncodedObject16345920
Ref: 50e716345920
Ref: c-api/unicode c PyUnicode_Append16346740
Ref: 50cc16346740
Ref: c-api/unicode c PyUnicode_AppendAndDel16347212
Ref: 50cd16347212
Ref: c-api/unicode c PyUnicode_BuildEncodingMap16347505
Ref: 1a4a16347505
Ref: c-api/unicode c PyUnicode_GetDefaultEncoding16348080
Ref: 50ec16348080
Ref: c-api/unicode c PyUnicode_GetLength16348403
Ref: ab216348403
Ref: c-api/unicode c PyUnicode_CopyCharacters16348700
Ref: ab416348700
Ref: c-api/unicode c PyUnicode_Resize16349294
Ref: 50ee16349294
Ref: c-api/unicode c PyUnicode_Fill16349975
Ref: 139516349975
Ref: c-api/unicode c PyUnicode_WriteChar16350581
Ref: 137a16350581
Ref: c-api/unicode c PyUnicode_ReadChar16351303
Ref: 137916351303
Ref: c-api/unicode c PyUnicode_Substring16351803
Ref: ab516351803
Ref: c-api/unicode c PyUnicode_AsUCS416352275
Ref: 138016352275
Ref: c-api/unicode c PyUnicode_AsUCS4Copy16352800
Ref: aba16352800
Node: Locale Encoding16353243
Ref: c-api/unicode locale-encoding16353386
Ref: 534f16353386
Ref: c-api/unicode c PyUnicode_DecodeLocaleAndSize16353520
Ref: dc416353520
Ref: c-api/unicode c PyUnicode_DecodeLocale16354775
Ref: 50d916354775
Ref: c-api/unicode c PyUnicode_EncodeLocale16355138
Ref: dc516355138
Ref: Locale Encoding-Footnote-116356405
Ref: Locale Encoding-Footnote-216356447
Node: File System Encoding16356489
Ref: c-api/unicode file-system-encoding16356609
Ref: 535016356609
Ref: c-api/unicode c PyUnicode_FSConverter16356970
Ref: f1716356970
Ref: c-api/unicode c PyUnicode_FSDecoder16358229
Ref: 79816358229
Ref: c-api/unicode c PyUnicode_DecodeFSDefaultAndSize16359333
Ref: 50d716359333
Ref: c-api/unicode c PyUnicode_DecodeFSDefault16359919
Ref: 1a7016359919
Ref: c-api/unicode c PyUnicode_EncodeFSDefault16360384
Ref: 1e1916360384
Ref: File System Encoding-Footnote-116361117
Ref: File System Encoding-Footnote-216361159
Node: wchar_t Support16361201
Ref: c-api/unicode wchar-t-support16361297
Ref: 535116361297
Ref: c-api/unicode c PyUnicode_FromWideChar16361403
Ref: 139416361403
Ref: c-api/unicode c PyUnicode_AsWideChar16361843
Ref: 1e2016361843
Ref: c-api/unicode c PyUnicode_AsWideCharString16362836
Ref: abb16362836
Node: Built-in Codecs16363972
Ref: c-api/unicode built-in-codecs16364109
Ref: 535216364109
Ref: c-api/unicode builtincodecs16364109
Ref: 534e16364109
Node: Generic Codecs16365330
Ref: c-api/unicode generic-codecs16365417
Ref: 535316365417
Ref: c-api/unicode c Py_UNICODE_REPLACEMENT_CHARACTER16365500
Ref: 535416365500
Ref: c-api/unicode c PyUnicode_Decode16365784
Ref: 1daf16365784
Ref: c-api/unicode c PyUnicode_AsEncodedString16366372
Ref: 50cf16366372
Node: UTF-8 Codecs16366946
Ref: c-api/unicode utf-8-codecs16367055
Ref: 535516367055
Ref: c-api/unicode c PyUnicode_DecodeUTF816367133
Ref: 50e316367133
Ref: c-api/unicode c PyUnicode_DecodeUTF8Stateful16367500
Ref: 1aff16367500
Ref: c-api/unicode c PyUnicode_AsUTF8String16368068
Ref: 139616368068
Ref: c-api/unicode c PyUnicode_AsUTF8AndSize16368537
Ref: a9b16368537
Ref: c-api/unicode c PyUnicode_AsUTF816369858
Ref: 42416369858
Ref: UTF-8 Codecs-Footnote-116370632
Node: UTF-32 Codecs16370685
Ref: c-api/unicode utf-32-codecs16370793
Ref: 535616370793
Ref: c-api/unicode c PyUnicode_DecodeUTF3216370874
Ref: 50df16370874
Ref: c-api/unicode c PyUnicode_DecodeUTF32Stateful16372083
Ref: 50e016372083
Ref: c-api/unicode c PyUnicode_AsUTF32String16372770
Ref: 50d116372770
Node: UTF-16 Codecs16373176
Ref: c-api/unicode utf-16-codecs16373284
Ref: 535716373284
Ref: c-api/unicode c PyUnicode_DecodeUTF1616373365
Ref: 50dd16373365
Ref: c-api/unicode c PyUnicode_DecodeUTF16Stateful16374658
Ref: 50de16374658
Ref: c-api/unicode c PyUnicode_AsUTF16String16375354
Ref: 50d016375354
Node: UTF-7 Codecs16375760
Ref: c-api/unicode utf-7-codecs16375876
Ref: 535816375876
Ref: c-api/unicode c PyUnicode_DecodeUTF716375954
Ref: 50e116375954
Ref: c-api/unicode c PyUnicode_DecodeUTF7Stateful16376321
Ref: 50e216376321
Node: Unicode-Escape Codecs16376891
Ref: c-api/unicode unicode-escape-codecs16377019
Ref: 535916377019
Ref: c-api/unicode c PyUnicode_DecodeUnicodeEscape16377128
Ref: 50e416377128
Ref: c-api/unicode c PyUnicode_AsUnicodeEscapeString16377513
Ref: 139716377513
Node: Raw-Unicode-Escape Codecs16377888
Ref: c-api/unicode raw-unicode-escape-codecs16378018
Ref: 535a16378018
Ref: c-api/unicode c PyUnicode_DecodeRawUnicodeEscape16378139
Ref: 50dc16378139
Ref: c-api/unicode c PyUnicode_AsRawUnicodeEscapeString16378531
Ref: 139816378531
Node: Latin-1 Codecs16378914
Ref: c-api/unicode latin-1-codecs16379035
Ref: 535b16379035
Ref: c-api/unicode c PyUnicode_DecodeLatin116379232
Ref: 50d816379232
Ref: c-api/unicode c PyUnicode_AsLatin1String16379603
Ref: 139916379603
Node: ASCII Codecs16379969
Ref: c-api/unicode ascii-codecs16380085
Ref: 535c16380085
Ref: c-api/unicode c PyUnicode_DecodeASCII16380233
Ref: 50d416380233
Ref: c-api/unicode c PyUnicode_AsASCIIString16380601
Ref: 139a16380601
Node: Character Map Codecs16380965
Ref: c-api/unicode character-map-codecs16381090
Ref: 535d16381090
Ref: c-api/unicode c PyUnicode_DecodeCharmap16381570
Ref: 50d516381570
Ref: c-api/unicode c PyUnicode_AsCharmapString16382470
Ref: 50ce16382470
Ref: c-api/unicode c PyUnicode_Translate16383254
Ref: 50f216383254
Node: MBCS codecs for Windows16384160
Ref: c-api/unicode mbcs-codecs-for-windows16384264
Ref: 535e16384264
Ref: c-api/unicode c PyUnicode_DecodeMBCS16384624
Ref: 50da16384624
Ref: c-api/unicode c PyUnicode_DecodeMBCSStateful16385020
Ref: 50db16385020
Ref: c-api/unicode c PyUnicode_DecodeCodePageStateful16385591
Ref: 50d616385591
Ref: c-api/unicode c PyUnicode_AsMBCSString16386011
Ref: 139b16386011
Ref: c-api/unicode c PyUnicode_EncodeCodePage16386408
Ref: 139c16386408
Node: Methods and Slot Functions16386901
Ref: c-api/unicode methods-and-slot-functions16387038
Ref: 535f16387038
Ref: c-api/unicode unicodemethodsandslots16387038
Ref: 536016387038
Ref: c-api/unicode c PyUnicode_Concat16387361
Ref: 13a916387361
Ref: c-api/unicode c PyUnicode_Split16387597
Ref: 50f016387597
Ref: c-api/unicode c PyUnicode_RSplit16388226
Ref: 187f16388226
Ref: c-api/unicode c PyUnicode_Splitlines16388649
Ref: 50f116388649
Ref: c-api/unicode c PyUnicode_Partition16389069
Ref: 188016389069
Ref: c-api/unicode c PyUnicode_RPartition16389703
Ref: 188116389703
Ref: c-api/unicode c PyUnicode_Join16390265
Ref: 13aa16390265
Ref: c-api/unicode c PyUnicode_Tailmatch16390555
Ref: ab716390555
Ref: c-api/unicode c PyUnicode_Find16391013
Ref: 50e516391013
Ref: c-api/unicode c PyUnicode_FindChar16391623
Ref: ab816391623
Ref: c-api/unicode c PyUnicode_Count16392405
Ref: 50d316392405
Ref: c-api/unicode c PyUnicode_Replace16392724
Ref: 50ed16392724
Ref: c-api/unicode c PyUnicode_Compare16393152
Ref: ab616393152
Ref: c-api/unicode c PyUnicode_Equal16393599
Ref: 3b216393599
Ref: c-api/unicode c PyUnicode_EqualToUTF8AndSize16394302
Ref: 61916394302
Ref: c-api/unicode c PyUnicode_EqualToUTF816394905
Ref: 61a16394905
Ref: c-api/unicode c PyUnicode_CompareWithASCIIString16395288
Ref: 146f16395288
Ref: c-api/unicode c PyUnicode_RichCompare16395789
Ref: 50ef16395789
Ref: c-api/unicode c PyUnicode_Format16396464
Ref: 50e616396464
Ref: c-api/unicode c PyUnicode_Contains16396753
Ref: 50d216396753
Ref: c-api/unicode c PyUnicode_InternInPlace16397088
Ref: ab016397088
Ref: c-api/unicode c PyUnicode_InternFromString16398464
Ref: 197416398464
Ref: c-api/unicode c PyUnicode_CHECK_INTERNED16399317
Ref: 536116399317
Node: PyUnicodeWriter16399855
Ref: c-api/unicode pyunicodewriter16399994
Ref: 536216399994
Ref: c-api/unicode c PyUnicodeWriter16400161
Ref: 3b316400161
Ref: c-api/unicode c PyUnicodeWriter_Create16400373
Ref: 3b416400373
Ref: c-api/unicode c PyUnicodeWriter_Finish16400727
Ref: 3b716400727
Ref: c-api/unicode c PyUnicodeWriter_Discard16401025
Ref: 3b616401025
Ref: c-api/unicode c PyUnicodeWriter_WriteChar16401291
Ref: 3ba16401291
Ref: c-api/unicode c PyUnicodeWriter_WriteUTF816401564
Ref: 3bf16401564
Ref: c-api/unicode c PyUnicodeWriter_WriteASCII16402090
Ref: 3b916402090
Ref: c-api/unicode c PyUnicodeWriter_WriteWideChar16402655
Ref: 3c016402655
Ref: c-api/unicode c PyUnicodeWriter_WriteUCS416403077
Ref: 3be16403077
Ref: c-api/unicode c PyUnicodeWriter_WriteStr16403403
Ref: 3bc16403403
Ref: c-api/unicode c PyUnicodeWriter_WriteRepr16403706
Ref: 3bb16403706
Ref: c-api/unicode c PyUnicodeWriter_WriteSubstring16404011
Ref: 3bd16404011
Ref: c-api/unicode c PyUnicodeWriter_Format16404517
Ref: 3b816404517
Ref: c-api/unicode c PyUnicodeWriter_DecodeUTF8Stateful16404841
Ref: 3b516404841
Node: Deprecated API<2>16405777
Ref: c-api/unicode deprecated-api16405881
Ref: 536316405881
Ref: c-api/unicode c Py_UNICODE16405964
Ref: 3e016405964
Ref: c-api/unicode c PyUnicode_READY16406431
Ref: 43416406431
Ref: c-api/unicode c PyUnicode_IS_READY16406858
Ref: 536416406858
Node: Tuple Objects16407263
Ref: c-api/tuple doc16407396
Ref: 536516407396
Ref: c-api/tuple translation-repo16407396
Ref: 536616407396
Ref: c-api/tuple tuple-objects16407396
Ref: 536716407396
Ref: c-api/tuple tupleobjects16407396
Ref: 536816407396
Ref: c-api/tuple c PyTupleObject16407443
Ref: 51fc16407443
Ref: c-api/tuple c PyTuple_Type16407557
Ref: 50b116407557
Ref: c-api/tuple c PyTuple_Check16407806
Ref: 536916407806
Ref: c-api/tuple c PyTuple_CheckExact16407982
Ref: 536a16407982
Ref: c-api/tuple c PyTuple_New16408169
Ref: 63e16408169
Ref: c-api/tuple c PyTuple_Pack16408419
Ref: 50af16408419
Ref: c-api/tuple c PyTuple_Size16408862
Ref: 50b016408862
Ref: c-api/tuple c PyTuple_GET_SIZE16409101
Ref: 536b16409101
Ref: c-api/tuple c PyTuple_GetItem16409239
Ref: 4ea016409239
Ref: c-api/tuple c PyTuple_GET_ITEM16409888
Ref: 536c16409888
Ref: c-api/tuple c PyTuple_GetSlice16410122
Ref: 50ae16410122
Ref: c-api/tuple c PyTuple_SetItem16410586
Ref: 4ea116410586
Ref: c-api/tuple c PyTuple_SET_ITEM16411099
Ref: 62e16411099
Ref: c-api/tuple c _PyTuple_Resize16411964
Ref: 171216411964
Node: Struct Sequence Objects16412880
Ref: c-api/tuple id116412999
Ref: 536d16412999
Ref: c-api/tuple struct-sequence-objects16412999
Ref: 13c716412999
Ref: c-api/tuple c PyStructSequence_NewType16413307
Ref: 509116413307
Ref: c-api/tuple c PyStructSequence_InitType16413736
Ref: 120516413736
Ref: c-api/tuple c PyStructSequence_InitType216413914
Ref: 120416413914
Ref: c-api/tuple c PyStructSequence_Desc16414185
Ref: db616414185
Ref: c-api/tuple c PyStructSequence_Desc name16414365
Ref: 536e16414365
Ref: c-api/tuple c PyStructSequence_Desc doc16414528
Ref: 536f16414528
Ref: c-api/tuple c PyStructSequence_Desc fields16414632
Ref: 537016414632
Ref: c-api/tuple c PyStructSequence_Desc n_in_sequence16414789
Ref: 537116414789
Ref: c-api/tuple c PyStructSequence_Field16414912
Ref: db516414912
Ref: c-api/tuple c PyStructSequence_Field name16415322
Ref: 537216415322
Ref: c-api/tuple c PyStructSequence_Field doc16415523
Ref: 537316415523
Ref: c-api/tuple c PyStructSequence_UnnamedField16415609
Ref: b7b16415609
Ref: c-api/tuple c PyStructSequence_New16415871
Ref: 509016415871
Ref: c-api/tuple c PyStructSequence_GetItem16416218
Ref: 508f16416218
Ref: c-api/tuple c PyStructSequence_GET_ITEM16416637
Ref: 537416416637
Ref: c-api/tuple c PyStructSequence_SetItem16416966
Ref: 509216416966
Ref: c-api/tuple c PyStructSequence_SET_ITEM16417483
Ref: 537516417483
Node: List Objects16417752
Ref: c-api/list doc16417849
Ref: 537616417849
Ref: c-api/list list-objects16417849
Ref: 537716417849
Ref: c-api/list listobjects16417849
Ref: 537816417849
Ref: c-api/list translation-repo16417849
Ref: 537916417849
Ref: c-api/list c PyListObject16417894
Ref: 528016417894
Ref: c-api/list c PyList_Type16418006
Ref: 4ec416418006
Ref: c-api/list c PyList_Check16418255
Ref: 537a16418255
Ref: c-api/list c PyList_CheckExact16418428
Ref: 537b16418428
Ref: c-api/list c PyList_New16418612
Ref: 4f2116418612
Ref: c-api/list c PyList_Size16419388
Ref: 162116419388
Ref: c-api/list c PyList_GET_SIZE16419614
Ref: 537c16419614
Ref: c-api/list c PyList_GetItemRef16419759
Ref: 5fe16419759
Ref: c-api/list c PyList_GetItem16420298
Ref: 5ff16420298
Ref: c-api/list c PyList_GET_ITEM16420631
Ref: 4f3716420631
Ref: c-api/list c PyList_SetItem16420858
Ref: 18a216420858
Ref: c-api/list c PyList_SET_ITEM16421343
Ref: 62f16421343
Ref: c-api/list c PyList_Insert16421992
Ref: 18a116421992
Ref: c-api/list c PyList_Append16422344
Ref: 501716422344
Ref: c-api/list c PyList_GetSlice16422646
Ref: 501916422646
Ref: c-api/list c PyList_SetSlice16423099
Ref: 501b16423099
Ref: c-api/list c PyList_Extend16423608
Ref: 60016423608
Ref: c-api/list c PyList_Clear16424051
Ref: 60116424051
Ref: c-api/list c PyList_Sort16424425
Ref: 501c16424425
Ref: c-api/list c PyList_Reverse16424654
Ref: 501a16424654
Ref: c-api/list c PyList_AsTuple16424896
Ref: 501816424896
Node: Container Objects16425159
Ref: c-api/concrete container-objects16425288
Ref: 537d16425288
Ref: c-api/concrete mapobjects16425288
Ref: 537e16425288
Node: Dictionary Objects16425386
Ref: c-api/dict doc16425478
Ref: 537f16425478
Ref: c-api/dict dictionary-objects16425478
Ref: 538016425478
Ref: c-api/dict dictobjects16425478
Ref: 538116425478
Ref: c-api/dict c PyDictObject16425533
Ref: 64f16425533
Ref: c-api/dict c PyDict_Type16425651
Ref: 4f9e16425651
Ref: c-api/dict c PyDict_Check16425906
Ref: 52ae16425906
Ref: c-api/dict c PyDict_CheckExact16426079
Ref: 538216426079
Ref: c-api/dict c PyDict_New16426263
Ref: 4f9c16426263
Ref: c-api/dict c PyDictProxy_New16426466
Ref: 4f8f16426466
Ref: c-api/dict c PyDictProxy_Type16426865
Ref: 4f9016426865
Ref: c-api/dict c PyDict_Clear16427455
Ref: 4f9516427455
Ref: c-api/dict c PyDict_Contains16427605
Ref: 5de16427605
Ref: c-api/dict c PyDict_ContainsString16427938
Ref: 5dd16427938
Ref: c-api/dict c PyDict_Copy16428212
Ref: 66216428212
Ref: c-api/dict c PyDict_SetItem16428441
Ref: 4ea216428441
Ref: c-api/dict c PyDict_SetItemString16428847
Ref: 197516428847
Ref: c-api/dict c PyDict_DelItem16429153
Ref: 4f9616429153
Ref: c-api/dict c PyDict_DelItemString16429536
Ref: 4f9716429536
Ref: c-api/dict c PyDict_GetItemRef16429817
Ref: 5e016429817
Ref: c-api/dict c PyDict_GetItem16430448
Ref: 62816430448
Ref: c-api/dict c PyDict_GetItemWithError16431233
Ref: 5e116431233
Ref: c-api/dict c PyDict_GetItemString16431669
Ref: 62916431669
Ref: c-api/dict c PyDict_GetItemStringRef16432393
Ref: 42116432393
Ref: c-api/dict c PyDict_SetDefault16432754
Ref: 5e416432754
Ref: c-api/dict c PyDict_SetDefaultRef16433375
Ref: 5e316433375
Ref: c-api/dict c PyDict_Pop16434473
Ref: 42216434473
Ref: c-api/dict c PyDict_PopString16435203
Ref: 5e516435203
Ref: c-api/dict c PyDict_Items16435487
Ref: 4f9816435487
Ref: c-api/dict c PyDict_Keys16435727
Ref: 4f9916435727
Ref: c-api/dict c PyDict_Values16435965
Ref: 4fa016435965
Ref: c-api/dict c PyDict_Size16436211
Ref: 4f9d16436211
Ref: c-api/dict c PyDict_GET_SIZE16436429
Ref: 538316436429
Ref: c-api/dict c PyDict_Next16436571
Ref: 197716436571
Ref: c-api/dict c PyDict_Merge16439429
Ref: 4f9a16439429
Ref: c-api/dict c PyDict_Update16440015
Ref: 4f9f16440015
Ref: c-api/dict c PyDict_MergeFromSeq216440475
Ref: 4f9b16440475
Ref: c-api/dict c PyDict_AddWatcher16441200
Ref: 3d016441200
Ref: c-api/dict c PyDict_ClearWatcher16441562
Ref: 538516441562
Ref: c-api/dict c PyDict_Watch16441865
Ref: 78516441865
Ref: c-api/dict c PyDict_Unwatch16442191
Ref: 538616442191
Ref: c-api/dict c PyDict_WatchEvent16442605
Ref: 538716442605
Ref: c-api/dict c PyDict_WatchCallback16442915
Ref: 538816442915
Node: Dictionary View Objects16445245
Ref: c-api/dict dictionary-view-objects16445352
Ref: 538916445352
Ref: c-api/dict c PyDictViewSet_Check16445417
Ref: 538a16445417
Ref: c-api/dict c PyDictKeys_Type16445718
Ref: 4f8e16445718
Ref: c-api/dict c PyDictKeys_Check16445952
Ref: 538b16445952
Ref: c-api/dict c PyDictValues_Type16446110
Ref: 4f9416446110
Ref: c-api/dict c PyDictValues_Check16446350
Ref: 538d16446350
Ref: c-api/dict c PyDictItems_Type16446511
Ref: 4f8a16446511
Ref: c-api/dict c PyDictItems_Check16446748
Ref: 538c16446748
Node: Ordered Dictionaries16446907
Ref: c-api/dict ordered-dictionaries16447014
Ref: 538e16447014
Ref: c-api/dict c PyODict_Type16447303
Ref: 538f16447303
Ref: c-api/dict c PyODict_Check16447493
Ref: 539016447493
Ref: c-api/dict c PyODict_CheckExact16447708
Ref: 539116447708
Ref: c-api/dict c PyODictKeys_Type16447934
Ref: 539216447934
Ref: c-api/dict c PyODictValues_Type16448068
Ref: 539316448068
Ref: c-api/dict c PyODictItems_Type16448211
Ref: 539416448211
Ref: c-api/dict c PyODict_New16448352
Ref: 539516448352
Ref: c-api/dict c PyODict_SetItem16448534
Ref: 539616448534
Ref: c-api/dict c PyODict_DelItem16448843
Ref: 539716448843
Ref: c-api/dict c PyODict_GetItem16449516
Ref: 539816449516
Ref: c-api/dict c PyODict_GetItemWithError16449721
Ref: 539916449721
Ref: c-api/dict c PyODict_GetItemString16449923
Ref: 539a16449923
Ref: c-api/dict c PyODict_Contains16450120
Ref: 539b16450120
Ref: c-api/dict c PyODict_Size16450308
Ref: 539c16450308
Ref: c-api/dict c PyODict_SIZE16450502
Ref: 539d16450502
Node: Set Objects16450615
Ref: c-api/set doc16450707
Ref: 539e16450707
Ref: c-api/set set-objects16450707
Ref: 539f16450707
Ref: c-api/set setobjects16450707
Ref: 53a016450707
Ref: c-api/set translation-repo16450707
Ref: 53a116450707
Ref: c-api/set c PySetObject16451484
Ref: 53a216451484
Ref: c-api/set c PySet_Type16452124
Ref: 508816452124
Ref: c-api/set c PyFrozenSet_Type16452320
Ref: 500416452320
Ref: c-api/set c PySet_Check16452679
Ref: 53a316452679
Ref: c-api/set c PyFrozenSet_Check16452845
Ref: 53a416452845
Ref: c-api/set c PyAnySet_Check16453023
Ref: 53a516453023
Ref: c-api/set c PySet_CheckExact16453230
Ref: a9f16453230
Ref: c-api/set c PyAnySet_CheckExact16453435
Ref: 53a616453435
Ref: c-api/set c PyFrozenSet_CheckExact16453653
Ref: 53a716453653
Ref: c-api/set c PySet_New16453841
Ref: 164b16453841
Ref: c-api/set c PyFrozenSet_New16454355
Ref: 164c16454355
Ref: c-api/set c PySet_Size16454964
Ref: 165016454964
Ref: c-api/set c PySet_GET_SIZE16455325
Ref: 53a816455325
Ref: c-api/set c PySet_Contains16455469
Ref: 164f16455469
Ref: c-api/set c PySet_Add16456020
Ref: 164d16456020
Ref: c-api/set c PySet_Discard16456814
Ref: 164e16456814
Ref: c-api/set c PySet_Pop16457421
Ref: 508716457421
Ref: c-api/set c PySet_Clear16457869
Ref: 508616457869
Node: Deprecated API<3>16458204
Ref: c-api/set deprecated-api16458269
Ref: 53a916458269
Ref: c-api/set c PySet_MINSIZE16458316
Ref: 53aa16458316
Node: Function Objects<2>16458884
Ref: c-api/concrete function-objects16459010
Ref: 53ab16459010
Ref: c-api/concrete otherobjects16459010
Ref: 53ac16459010
Node: Function Objects<3>16459233
Ref: c-api/function doc16459340
Ref: 53ad16459340
Ref: c-api/function function-objects16459340
Ref: 53ae16459340
Ref: c-api/function id116459340
Ref: 53af16459340
Ref: c-api/function c PyFunctionObject16459448
Ref: 78416459448
Ref: c-api/function c PyFunction_Type16459525
Ref: 53b016459525
Ref: c-api/function c PyFunction_Check16459755
Ref: 53b116459755
Ref: c-api/function c PyFunction_New16459975
Ref: 53b216459975
Ref: c-api/function c PyFunction_NewWithQualName16460615
Ref: 53b316460615
Ref: c-api/function c PyFunction_GetCode16461141
Ref: 53b416461141
Ref: c-api/function c PyFunction_GetGlobals16461342
Ref: 53b516461342
Ref: c-api/function c PyFunction_GetModule16461563
Ref: 53b616461563
Ref: c-api/function c PyFunction_GetDefaults16461985
Ref: 53b716461985
Ref: c-api/function c PyFunction_SetDefaults16462253
Ref: 53b816462253
Ref: c-api/function c PyFunction_SetVectorcall16462530
Ref: 78316462530
Ref: c-api/function c PyFunction_GetKwDefaults16462855
Ref: 53b916462855
Ref: c-api/function c PyFunction_SetKwDefaults16463142
Ref: 53ba16463142
Ref: c-api/function c PyFunction_GetClosure16463508
Ref: 53bb16463508
Ref: c-api/function c PyFunction_SetClosure16463775
Ref: 53bc16463775
Ref: c-api/function c PyFunction_GetAnnotations16464061
Ref: 1b1f16464061
Ref: c-api/function c PyFunction_SetAnnotations16464320
Ref: 53bd16464320
Ref: c-api/function c PyFunction_GET_CODE16464600
Ref: 53be16464600
Ref: c-api/function c PyFunction_GET_GLOBALS16464673
Ref: 53bf16464673
Ref: c-api/function c PyFunction_GET_MODULE16464759
Ref: 53c016464759
Ref: c-api/function c PyFunction_GET_DEFAULTS16464844
Ref: 53c116464844
Ref: c-api/function c PyFunction_GET_KW_DEFAULTS16464931
Ref: 53c216464931
Ref: c-api/function c PyFunction_GET_CLOSURE16465021
Ref: 53c316465021
Ref: c-api/function c PyFunction_GET_ANNOTATIONS16465107
Ref: 53c416465107
Ref: c-api/function c PyFunction_AddWatcher16465469
Ref: 53c516465469
Ref: c-api/function c PyFunction_ClearWatcher16465850
Ref: 53c616465850
Ref: c-api/function c PyFunction_WatchEvent16466218
Ref: 53c716466218
Ref: c-api/function c PyFunction_WatchCallback16466603
Ref: 53c816466603
Node: Instance Method Objects16468806
Ref: c-api/method doc16468936
Ref: 53c916468936
Ref: c-api/method instance-method-objects16468936
Ref: 53ca16468936
Ref: c-api/method instancemethod-objects16468936
Ref: 53cb16468936
Ref: c-api/method translation-repo16468936
Ref: 53cc16468936
Ref: c-api/method c PyInstanceMethod_Type16469203
Ref: 53cd16469203
Ref: c-api/method c PyInstanceMethod_Check16469404
Ref: 53ce16469404
Ref: c-api/method c PyInstanceMethod_New16469643
Ref: 53cf16469643
Ref: c-api/method c PyInstanceMethod_Function16469947
Ref: 53d016469947
Ref: c-api/method c PyInstanceMethod_GET_FUNCTION16470169
Ref: 53d116470169
Node: Method Objects16470418
Ref: c-api/method id116470541
Ref: 53d216470541
Ref: c-api/method method-objects16470541
Ref: 53d316470541
Ref: c-api/method c PyMethod_Type16470767
Ref: 53d416470767
Ref: c-api/method c PyMethod_Check16470980
Ref: 53d516470980
Ref: c-api/method c PyMethod_New16471194
Ref: 53d616471194
Ref: c-api/method c PyMethod_Function16471576
Ref: 53d716471576
Ref: c-api/method c PyMethod_GET_FUNCTION16471775
Ref: 53d816471775
Ref: c-api/method c PyMethod_Self16472005
Ref: 53d916472005
Ref: c-api/method c PyMethod_GET_SELF16472193
Ref: 53da16472193
Node: Cell Objects16472405
Ref: c-api/cell doc16472517
Ref: 53db16472517
Ref: c-api/cell cell-objects16472517
Ref: 91116472517
Ref: c-api/cell id116472517
Ref: 53dc16472517
Ref: c-api/cell translation-repo16472517
Ref: 53dd16472517
Ref: c-api/cell c PyCellObject16473159
Ref: 53de16473159
Ref: c-api/cell c PyCell_Type16473235
Ref: 53df16473235
Ref: c-api/cell c PyCell_Check16473343
Ref: 53e016473343
Ref: c-api/cell c PyCell_New16473501
Ref: 53e116473501
Ref: c-api/cell c PyCell_Get16473719
Ref: 53e216473719
Ref: c-api/cell c PyCell_GET16473982
Ref: 53e316473982
Ref: c-api/cell c PyCell_Set16474227
Ref: 53e416474227
Ref: c-api/cell c PyCell_SET16474599
Ref: aad16474599
Node: Code Objects16474862
Ref: c-api/code doc16474977
Ref: 53e516474977
Ref: c-api/code code-objects16474977
Ref: 53e616474977
Ref: c-api/code codeobjects16474977
Ref: 7d316474977
Ref: c-api/code translation-repo16474977
Ref: 53e716474977
Ref: c-api/code c PyCodeObject16475182
Ref: 97c16475182
Ref: c-api/code c PyCode_Type16475346
Ref: 53e816475346
Ref: c-api/code c PyCode_Check16475508
Ref: 53e916475508
Ref: c-api/code c PyCode_GetNumFree16475649
Ref: 53ea16475649
Ref: c-api/code c PyUnstable_Code_GetFirstFree16475824
Ref: 62716475824
Ref: c-api/code c PyUnstable_Code_New16476400
Ref: 53eb16476400
Ref: c-api/code c PyCode_NewWithPosOnlyArgs16477845
Ref: 53ec16477845
Ref: c-api/code c PyUnstable_Code_NewWithPosOnlyArgs16477845
Ref: 53ed16477845
Ref: c-api/code c PyCode_NewEmpty16479083
Ref: 155816479083
Ref: c-api/code c PyCode_Addr2Line16479443
Ref: a8b16479443
Ref: c-api/code c PyCode_Addr2Location16479846
Ref: 7d216479846
Ref: c-api/code c PyCode_GetCode16480326
Ref: 97d16480326
Ref: c-api/code c PyCode_GetVarnames16480910
Ref: 97e16480910
Ref: c-api/code c PyCode_GetCellvars16481274
Ref: 97f16481274
Ref: c-api/code c PyCode_GetFreevars16481683
Ref: 98016481683
Ref: c-api/code c PyCode_AddWatcher16482068
Ref: 78816482068
Ref: c-api/code c PyCode_ClearWatcher16482429
Ref: 78916482429
Ref: c-api/code c PyCodeEvent16482788
Ref: 53ee16482788
Ref: c-api/code c PyCode_WatchCallback16482969
Ref: 53ef16482969
Ref: c-api/code c PyCode_Optimize16484749
Ref: 53f016484749
Ref: Code Objects-Footnote-116485163
Node: Code Object Flags16485245
Ref: c-api/code c-codeobject-flags16485365
Ref: 51b916485365
Ref: c-api/code code-object-flags16485365
Ref: 53f116485365
Ref: c-api/code c CO_OPTIMIZED16486413
Ref: 53f216486413
Ref: c-api/code c CO_NEWLOCALS16486614
Ref: 53f316486614
Ref: c-api/code c CO_VARARGS16486813
Ref: 53f416486813
Ref: c-api/code c CO_VARKEYWORDS16487016
Ref: 53f516487016
Ref: c-api/code c CO_NESTED16487214
Ref: 53f616487214
Ref: c-api/code c CO_GENERATOR16487415
Ref: 53f716487415
Ref: c-api/code c CO_COROUTINE16487616
Ref: 53f816487616
Ref: c-api/code c CO_ITERABLE_COROUTINE16487826
Ref: 53f916487826
Ref: c-api/code c CO_ASYNC_GENERATOR16488033
Ref: 53fa16488033
Ref: c-api/code c CO_HAS_DOCSTRING16488238
Ref: 53fb16488238
Ref: c-api/code c CO_METHOD16488436
Ref: 53fc16488436
Ref: c-api/code c CO_FUTURE_DIVISION16488643
Ref: 53fd16488643
Ref: c-api/code c CO_FUTURE_ABSOLUTE_IMPORT16488862
Ref: 53fe16488862
Ref: c-api/code c CO_FUTURE_WITH_STATEMENT16489080
Ref: 53ff16489080
Ref: c-api/code c CO_FUTURE_PRINT_FUNCTION16489298
Ref: 540016489298
Ref: c-api/code c CO_FUTURE_UNICODE_LITERALS16489518
Ref: 540116489518
Ref: c-api/code c CO_FUTURE_GENERATOR_STOP16489736
Ref: 540216489736
Ref: c-api/code c CO_FUTURE_ANNOTATIONS16489951
Ref: 51b816489951
Node: Extra information16490065
Ref: c-api/code extra-information16490164
Ref: 540316490164
Ref: c-api/code c _PyEval_RequestCodeExtraIndex16490537
Ref: 540416490537
Ref: c-api/code c PyUnstable_Eval_RequestCodeExtraIndex16490537
Ref: 540516490537
Ref: c-api/code c _PyCode_GetExtra16491575
Ref: 540616491575
Ref: c-api/code c PyUnstable_Code_GetExtra16491575
Ref: 540716491575
Ref: c-api/code c _PyCode_SetExtra16492353
Ref: 540816492353
Ref: c-api/code c PyUnstable_Code_SetExtra16492353
Ref: 540916492353
Node: Other Objects16493014
Ref: c-api/concrete other-objects16493150
Ref: 540a16493150
Node: File Objects16493656
Ref: c-api/file doc16493741
Ref: 540b16493741
Ref: c-api/file file-objects16493741
Ref: 540c16493741
Ref: c-api/file fileobjects16493741
Ref: 540d16493741
Ref: c-api/file c PyFile_FromFd16494322
Ref: 4ffc16494322
Ref: c-api/file c PyObject_AsFileDescriptor16495351
Ref: 505f16495351
Ref: c-api/file c PyFile_GetLine16495803
Ref: 4ffd16495803
Ref: c-api/file c PyFile_SetOpenCodeHook16496644
Ref: 1a8216496644
Ref: c-api/file c Py_OpenCodeHookFunction16496899
Ref: 540e16496899
Ref: c-api/file c PyFile_OpenCodeObject16498009
Ref: 540f16498009
Ref: c-api/file c PyFile_OpenCode16498609
Ref: 541016498609
Ref: c-api/file c PyFile_WriteObject16498813
Ref: 4ffe16498813
Ref: c-api/file c PyFile_WriteString16499257
Ref: 4fff16499257
Node: Deprecated API<4>16499553
Ref: c-api/file deprecated-api16499619
Ref: 541116499619
Ref: c-api/file c PyFile_NewStdPrinter16499845
Ref: 541216499845
Ref: c-api/file c PyStdPrinter_Type16500028
Ref: 541316500028
Node: Module Objects16500301
Ref: c-api/module doc16500413
Ref: 541416500413
Ref: c-api/module module-objects16500413
Ref: 541516500413
Ref: c-api/module moduleobjects16500413
Ref: 541616500413
Ref: c-api/module translation-repo16500413
Ref: 541716500413
Ref: c-api/module c PyModule_Type16500460
Ref: 503b16500460
Ref: c-api/module c PyModule_Check16500721
Ref: 541816500721
Ref: c-api/module c PyModule_CheckExact16500886
Ref: 541916500886
Ref: c-api/module c PyModule_NewObject16501071
Ref: 503916501071
Ref: c-api/module c PyModule_New16501818
Ref: 503816501818
Ref: c-api/module c PyModule_GetDict16502095
Ref: 503516502095
Ref: c-api/module c PyModule_GetNameObject16502866
Ref: 503716502866
Ref: c-api/module c PyModule_GetName16503282
Ref: 503616503282
Ref: c-api/module c PyModule_GetState16503678
Ref: b7916503678
Ref: c-api/module c PyModule_GetDef16503960
Ref: 503416503960
Ref: c-api/module c PyModule_GetFilenameObject16504414
Ref: 42e16504414
Ref: c-api/module c PyModule_GetFilename16504915
Ref: 42d16504915
Node: Module definitions16505476
Ref: c-api/module module-definitions16505614
Ref: 541a16505614
Ref: c-api/module pymoduledef16505614
Ref: 541b16505614
Ref: c-api/module c PyModuleDef16506456
Ref: b7616506456
Ref: c-api/module c PyModuleDef m_base16506876
Ref: 541d16506876
Ref: c-api/module c PyModuleDef m_name16506993
Ref: 541e16506993
Ref: c-api/module c PyModuleDef m_doc16507068
Ref: 541f16507068
Ref: c-api/module c PyModuleDef m_size16507230
Ref: b7816507230
Ref: c-api/module c PyModuleDef m_methods16508297
Ref: 542016508297
Ref: c-api/module c PyModuleDef m_slots16508526
Ref: 51ed16508526
Ref: c-api/module c PyModuleDef m_slots m_reload16508928
Ref: 542116508928
Ref: c-api/module c PyModuleDef m_traverse16508988
Ref: b7316508988
Ref: c-api/module c PyModuleDef m_clear16509728
Ref: b7416509728
Ref: c-api/module c PyModuleDef m_free16510798
Ref: b7516510798
Ref: Module definitions-Footnote-116511583
Node: Module slots16511625
Ref: c-api/module module-slots16511692
Ref: 542316511692
Ref: c-api/module c PyModuleDef_Slot16511735
Ref: 503116511735
Ref: c-api/module c PyModuleDef_Slot slot16511860
Ref: 542416511860
Ref: c-api/module c PyModuleDef_Slot value16511962
Ref: 542516511962
Ref: c-api/module c Py_mod_create16512121
Ref: 512916512121
Ref: c-api/module c Py_mod_create create_module16512376
Ref: 542616512376
Ref: c-api/module c Py_mod_exec16513835
Ref: b7716513835
Ref: c-api/module c Py_mod_exec exec_module16514169
Ref: 542716514169
Ref: c-api/module c Py_mod_multiple_interpreters16514384
Ref: 512a16514384
Ref: c-api/module c Py_MOD_MULTIPLE_INTERPRETERS_NOT_SUPPORTED16514534
Ref: 4e8d16514534
Ref: c-api/module c Py_MOD_MULTIPLE_INTERPRETERS_SUPPORTED16514670
Ref: 542816514670
Ref: c-api/module c Py_MOD_PER_INTERPRETER_GIL_SUPPORTED16514915
Ref: 542916514915
Ref: c-api/module c Py_mod_gil16515521
Ref: 48316515521
Ref: c-api/module c Py_MOD_GIL_USED16515653
Ref: 542a16515653
Ref: c-api/module c Py_MOD_GIL_NOT_USED16515845
Ref: 542b16515845
Ref: Module slots-Footnote-116516475
Node: Creating extension modules dynamically16516517
Ref: c-api/module creating-extension-modules-dynamically16516658
Ref: 542c16516658
Ref: c-api/module moduledef-dynamic16516658
Ref: 541c16516658
Ref: c-api/module c PyModule_Create16516938
Ref: 51ef16516938
Ref: c-api/module c PyModule_Create216517337
Ref: 503316517337
Ref: c-api/module c PyModule_FromDefAndSpec16518098
Ref: 10b516518098
Ref: c-api/module c PyModule_FromDefAndSpec216518492
Ref: 10b616518492
Ref: c-api/module c PyModule_ExecDef16519452
Ref: 10b716519452
Ref: c-api/module c PYTHON_API_VERSION16519703
Ref: 491616519703
Ref: c-api/module c PYTHON_ABI_VERSION16519940
Ref: 542d16519940
Node: Support functions16520168
Ref: c-api/module support-functions16520307
Ref: 542e16520307
Ref: c-api/module c PyModule_AddObjectRef16520633
Ref: 60a16520633
Ref: c-api/module c PyModule_Add16522556
Ref: 60916522556
Ref: c-api/module c PyModule_AddObject16523134
Ref: 60b16523134
Ref: c-api/module c PyModule_AddIntConstant16524571
Ref: 174316524571
Ref: c-api/module c PyModule_AddStringConstant16525100
Ref: 174416525100
Ref: c-api/module c PyModule_AddIntMacro16525704
Ref: 15fa16525704
Ref: c-api/module c PyModule_AddStringMacro16526061
Ref: 15f916526061
Ref: c-api/module c PyModule_AddType16526156
Ref: b6e16526156
Ref: c-api/module c PyModule_AddFunctions16526630
Ref: 503216526630
Ref: c-api/module c PyModule_SetDocString16527720
Ref: 503a16527720
Ref: c-api/module c PyUnstable_Module_SetGIL16528258
Ref: 49e16528258
Node: Module lookup single-phase initialization16529290
Ref: c-api/module module-lookup-single-phase-initialization16529385
Ref: 542f16529385
Ref: c-api/module c PyState_FindModule16529910
Ref: 508d16529910
Ref: c-api/module c PyState_AddModule16530474
Ref: 508c16530474
Ref: c-api/module c PyState_RemoveModule16531703
Ref: 508e16531703
Node: Iterator Objects16532071
Ref: c-api/iterator doc16532190
Ref: 543016532190
Ref: c-api/iterator id116532190
Ref: 543116532190
Ref: c-api/iterator iterator-objects16532190
Ref: 543216532190
Ref: c-api/iterator translation-repo16532190
Ref: 543316532190
Ref: c-api/iterator c PySeqIter_Type16532588
Ref: 507716532588
Ref: c-api/iterator c PySeqIter_Check16532877
Ref: 543416532877
Ref: c-api/iterator c PySeqIter_New16533034
Ref: 507616533034
Ref: c-api/iterator c PyCallIter_Type16533371
Ref: 4f6916533371
Ref: c-api/iterator c PyCallIter_Check16533629
Ref: 543516533629
Ref: c-api/iterator c PyCallIter_New16533788
Ref: 4f6816533788
Node: Range Objects16534363
Ref: c-api/iterator range-objects16534460
Ref: 543616534460
Ref: c-api/iterator c PyRange_Type16534507
Ref: 507416534507
Ref: c-api/iterator c PyRange_Check16534658
Ref: 543716534658
Node: Builtin Iterator Types16534826
Ref: c-api/iterator builtin-iterator-types16534954
Ref: 543816534954
Ref: c-api/iterator c PyEnum_Type16535495
Ref: 4fa216535495
Ref: c-api/iterator c PyFilter_Type16535672
Ref: 500016535672
Ref: c-api/iterator c PyMap_Type16535856
Ref: 502816535856
Ref: c-api/iterator c PyReversed_Type16535973
Ref: 507516535973
Ref: c-api/iterator c PyZip_Type16536159
Ref: 50f816536159
Node: Other Iterator Objects16536235
Ref: c-api/iterator other-iterator-objects16536341
Ref: 543916536341
Ref: c-api/iterator c PyByteArrayIter_Type16536406
Ref: 4f5016536406
Ref: c-api/iterator c PyBytesIter_Type16536512
Ref: 4f5616536512
Ref: c-api/iterator c PyListIter_Type16536614
Ref: 501516536614
Ref: c-api/iterator c PyListRevIter_Type16536715
Ref: 501616536715
Ref: c-api/iterator c PySetIter_Type16536819
Ref: 508516536819
Ref: c-api/iterator c PyTupleIter_Type16536919
Ref: 50ad16536919
Ref: c-api/iterator c PyRangeIter_Type16537021
Ref: 507316537021
Ref: c-api/iterator c PyLongRangeIter_Type16537123
Ref: 501d16537123
Ref: c-api/iterator c PyDictIterKey_Type16537229
Ref: 4f8c16537229
Ref: c-api/iterator c PyDictRevIterKey_Type16537333
Ref: 4f9216537333
Ref: c-api/iterator c PyDictIterValue_Type16537460
Ref: 4f8d16537460
Ref: c-api/iterator c PyDictRevIterValue_Type16537566
Ref: 4f9316537566
Ref: c-api/iterator c PyDictIterItem_Type16537695
Ref: 4f8b16537695
Ref: c-api/iterator c PyDictRevIterItem_Type16537800
Ref: 4f9116537800
Ref: c-api/iterator c PyODictIter_Type16537928
Ref: 543a16537928
Node: Descriptor Objects16538469
Ref: c-api/descriptor doc16538584
Ref: 543b16538584
Ref: c-api/descriptor descriptor-objects16538584
Ref: 543c16538584
Ref: c-api/descriptor id116538584
Ref: 543d16538584
Ref: c-api/descriptor translation-repo16538584
Ref: 543e16538584
Ref: c-api/descriptor c PyProperty_Type16538763
Ref: 507216538763
Ref: c-api/descriptor c PyDescr_NewGetSet16538921
Ref: 4f8816538921
Ref: c-api/descriptor c PyDescr_NewMember16539124
Ref: 4f8916539124
Ref: c-api/descriptor c PyMemberDescr_Type16539325
Ref: 502c16539325
Ref: c-api/descriptor c PyGetSetDescr_Type16539693
Ref: 500716539693
Ref: c-api/descriptor c PyDescr_NewMethod16540059
Ref: 1d5d16540059
Ref: c-api/descriptor c PyMethodDescr_Type16540260
Ref: 503016540260
Ref: c-api/descriptor c PyDescr_NewWrapper16540618
Ref: 543f16540618
Ref: c-api/descriptor c PyWrapperDescr_Type16540796
Ref: 50f616540796
Ref: c-api/descriptor c PyDescr_NewClassMethod16541228
Ref: 4f8716541228
Ref: c-api/descriptor c PyDescr_IsData16541429
Ref: 1c9b16541429
Ref: c-api/descriptor c PyWrapper_New16541679
Ref: 50f716541679
Node: Built-in descriptors16541887
Ref: c-api/descriptor built-in-descriptors16541962
Ref: 544016541962
Ref: c-api/descriptor c PySuper_Type16542023
Ref: 509316542023
Ref: c-api/descriptor c PyClassMethod_Type16542234
Ref: 544116542234
Ref: c-api/descriptor c PyClassMethodDescr_Type16542414
Ref: 4f7516542414
Ref: c-api/descriptor c PyClassMethod_New16542771
Ref: 544216542771
Ref: c-api/descriptor c PyStaticMethod_Type16543184
Ref: 544316543184
Ref: c-api/descriptor c PyStaticMethod_New16543367
Ref: 544416543367
Node: Slice Objects16543783
Ref: c-api/slice doc16543900
Ref: 544516543900
Ref: c-api/slice id116543900
Ref: 544616543900
Ref: c-api/slice slice-objects16543900
Ref: 544716543900
Ref: c-api/slice translation-repo16543900
Ref: 544816543900
Ref: c-api/slice c PySlice_Type16543947
Ref: 508b16543947
Ref: c-api/slice c PySlice_Check16544151
Ref: 544916544151
Ref: c-api/slice c PySlice_New16544311
Ref: 508a16544311
Ref: c-api/slice c PySlice_GetIndices16544901
Ref: 508916544901
Ref: c-api/slice c PySlice_GetIndicesEx16545668
Ref: 43116545668
Ref: c-api/slice c PySlice_Unpack16547687
Ref: 43216547687
Ref: c-api/slice c PySlice_AdjustIndices16548351
Ref: 43316548351
Node: Ellipsis Object16548897
Ref: c-api/slice ellipsis-object16548962
Ref: 544a16548962
Ref: c-api/slice c PyEllipsis_Type16549013
Ref: 4fa116549013
Ref: c-api/slice c Py_Ellipsis16549236
Ref: 544b16549236
Ref: c-api/memoryview memoryview-objects16549516
Ref: 529316549516
Node: MemoryView objects16549516
Ref: c-api/memoryview doc16549636
Ref: 544c16549636
Ref: c-api/memoryview id116549636
Ref: 544d16549636
Ref: c-api/memoryview translation-repo16549636
Ref: 544e16549636
Ref: c-api/memoryview c PyMemoryView_Type16549849
Ref: 502f16549849
Ref: c-api/memoryview c PyMemoryView_FromObject16550116
Ref: 502d16550116
Ref: c-api/memoryview c PyBUF_READ16550563
Ref: 19f316550563
Ref: c-api/memoryview c PyBUF_WRITE16550692
Ref: 19f416550692
Ref: c-api/memoryview c PyMemoryView_FromMemory16550822
Ref: 137816550822
Ref: c-api/memoryview c PyMemoryView_FromBuffer16551221
Ref: 96616551221
Ref: c-api/memoryview c PyMemoryView_GetContiguous16551605
Ref: 502e16551605
Ref: c-api/memoryview c PyMemoryView_Check16552245
Ref: 544f16552245
Ref: c-api/memoryview c PyMemoryView_GET_BUFFER16552480
Ref: 545016552480
Ref: c-api/memoryview c PyMemoryView_GET_BASE16552802
Ref: 545116552802
Ref: c-api/picklebuffer picklebuffer-objects16553192
Ref: 545216553192
Node: Pickle buffer objects16553192
Ref: c-api/picklebuffer doc16553324
Ref: 545316553324
Ref: c-api/picklebuffer pickle-buffer-objects16553324
Ref: 545416553324
Ref: c-api/picklebuffer translation-repo16553324
Ref: 545516553324
Ref: c-api/picklebuffer c PyPickleBuffer_Type16553562
Ref: 545616553562
Ref: c-api/picklebuffer c PyPickleBuffer_Check16553807
Ref: 545716553807
Ref: c-api/picklebuffer c PyPickleBuffer_FromObject16553956
Ref: 545816553956
Ref: c-api/picklebuffer c PyPickleBuffer_GetBuffer16554393
Ref: 545916554393
Ref: c-api/picklebuffer c PyPickleBuffer_Release16554955
Ref: 545a16554955
Node: Weak Reference Objects<2>16555259
Ref: c-api/weakref doc16555384
Ref: 545b16555384
Ref: c-api/weakref translation-repo16555384
Ref: 545c16555384
Ref: c-api/weakref weak-reference-objects16555384
Ref: 545d16555384
Ref: c-api/weakref weakrefobjects16555384
Ref: 526716555384
Ref: c-api/weakref c PyWeakref_Check16555702
Ref: 545e16555702
Ref: c-api/weakref c PyWeakref_CheckRef16555859
Ref: 545f16555859
Ref: c-api/weakref c PyWeakref_CheckRefExact16556040
Ref: 546016556040
Ref: c-api/weakref c PyWeakref_CheckProxy16556232
Ref: 546116556232
Ref: c-api/weakref c PyWeakref_NewRef16556375
Ref: 1bce16556375
Ref: c-api/weakref c PyWeakref_NewProxy16557345
Ref: 50f516557345
Ref: c-api/weakref c PyWeakref_GetRef16558320
Ref: 3df16558320
Ref: c-api/weakref c PyWeakref_GetObject16558852
Ref: 3dd16558852
Ref: c-api/weakref c PyWeakref_GET_OBJECT16559620
Ref: 3de16559620
Ref: c-api/weakref c PyWeakref_IsDead16559961
Ref: 18c716559961
Ref: c-api/weakref c PyObject_ClearWeakRefs16560223
Ref: 79716560223
Ref: c-api/weakref c PyUnstable_Object_ClearWeakRefsNoCallbacks16560604
Ref: 197d16560604
Node: Capsules<2>16561532
Ref: c-api/capsule doc16561649
Ref: 546216561649
Ref: c-api/capsule capsules16561649
Ref: 29d716561649
Ref: c-api/capsule id116561649
Ref: 546316561649
Ref: c-api/capsule translation-repo16561649
Ref: 546416561649
Ref: c-api/capsule c PyCapsule16561819
Ref: 147a16561819
Ref: c-api/capsule c PyCapsule_Type16562264
Ref: 4f7416562264
Ref: c-api/capsule c PyCapsule_Destructor16562505
Ref: 4f6b16562505
Ref: c-api/capsule c PyCapsule_CheckExact16562812
Ref: 546516562812
Ref: c-api/capsule c PyCapsule_New16562967
Ref: 4eac16562967
Ref: c-api/capsule c PyCapsule_GetPointer16563939
Ref: 4f6f16563939
Ref: c-api/capsule c PyCapsule_GetDestructor16564441
Ref: 4f6d16564441
Ref: c-api/capsule c PyCapsule_GetContext16564929
Ref: 4f6c16564929
Ref: c-api/capsule c PyCapsule_GetName16565370
Ref: 4f6e16565370
Ref: c-api/capsule c PyCapsule_Import16565808
Ref: 1bf816565808
Ref: c-api/capsule c PyCapsule_IsValid16566823
Ref: 156416566823
Ref: c-api/capsule c PyCapsule_SetContext16567643
Ref: 4f7016567643
Ref: c-api/capsule c PyCapsule_SetDestructor16567920
Ref: 4f7116567920
Ref: c-api/capsule c PyCapsule_SetName16568216
Ref: 4f7216568216
Ref: c-api/capsule c PyCapsule_SetPointer16568641
Ref: 4f7316568641
Node: Frame Objects16568951
Ref: c-api/frame doc16569060
Ref: 546616569060
Ref: c-api/frame frame-objects16569060
Ref: 546716569060
Ref: c-api/frame translation-repo16569060
Ref: 546816569060
Ref: c-api/frame c PyFrameObject16569107
Ref: 98d16569107
Ref: c-api/frame c PyFrame_Type16569656
Ref: 98b16569656
Ref: c-api/frame c PyFrame_New16569947
Ref: 1ad716569947
Ref: c-api/frame c PyFrame_Check16570294
Ref: 98916570294
Ref: c-api/frame c PyFrame_GetBack16570520
Ref: 98a16570520
Ref: c-api/frame c PyFrame_GetBuiltins16570820
Ref: 97016570820
Ref: c-api/frame c PyFrame_GetCode16571125
Ref: 98e16571125
Ref: c-api/frame c PyFrame_GetGenerator16571472
Ref: 97116571472
Ref: c-api/frame c PyFrame_GetGlobals16571912
Ref: 97216571912
Ref: c-api/frame c PyFrame_GetLasti16572215
Ref: 97316572215
Ref: c-api/frame c PyFrame_GetVar16572417
Ref: 78a16572417
Ref: c-api/frame c PyFrame_GetVarString16572938
Ref: 78b16572938
Ref: c-api/frame c PyFrame_GetLocals16573228
Ref: 66116573228
Ref: c-api/frame c PyFrame_GetLineNumber16573954
Ref: 98f16573954
Ref: Frame Objects-Footnote-116574271
Node: Frame Locals Proxies16574313
Ref: c-api/frame frame-locals-proxies16574418
Ref: 546a16574418
Ref: c-api/frame c PyFrameLocalsProxy_Type16574880
Ref: 546916574880
Ref: c-api/frame c PyFrameLocalsProxy_Check16575007
Ref: 546b16575007
Ref: Frame Locals Proxies-Footnote-116575175
Node: Legacy Local Variable APIs16575217
Ref: c-api/frame legacy-local-variable-apis16575346
Ref: 546c16575346
Ref: c-api/frame c PyFrame_LocalsToFast16575548
Ref: 546d16575548
Ref: c-api/frame c PyFrame_FastToLocals16576094
Ref: 546e16576094
Ref: c-api/frame c PyFrame_FastToLocalsWithError16576557
Ref: 546f16576557
Ref: Legacy Local Variable APIs-Footnote-116577022
Node: Internal Frames16577064
Ref: c-api/frame internal-frames16577164
Ref: 547016577164
Ref: c-api/frame c _PyInterpreterFrame16577265
Ref: 195616577265
Ref: c-api/frame c PyUnstable_InterpreterFrame_GetCode16577393
Ref: 547116577393
Ref: c-api/frame c PyUnstable_InterpreterFrame_GetLasti16577842
Ref: 547216577842
Ref: c-api/frame c PyUnstable_InterpreterFrame_GetLine16578236
Ref: 547316578236
Ref: Internal Frames-Footnote-116578689
Node: Generator Objects16578731
Ref: c-api/gen doc16578849
Ref: 547416578849
Ref: c-api/gen gen-objects16578849
Ref: 547516578849
Ref: c-api/gen generator-objects16578849
Ref: 547616578849
Ref: c-api/gen translation-repo16578849
Ref: 547716578849
Ref: c-api/gen c PyGenObject16579149
Ref: 547a16579149
Ref: c-api/gen c PyGen_Type16579229
Ref: 547b16579229
Ref: c-api/gen c PyGen_Check16579341
Ref: 547c16579341
Ref: c-api/gen c PyGen_CheckExact16579503
Ref: 547d16579503
Ref: c-api/gen c PyGen_New16579685
Ref: 547816579685
Ref: c-api/gen c PyGen_NewWithQualName16579978
Ref: 547916579978
Ref: c-api/gen c PyGen_GetCode16580415
Ref: 547e16580415
Node: Asynchronous Generator Objects16580705
Ref: c-api/gen asynchronous-generator-objects16580815
Ref: 547f16580815
Ref: c-api/gen c PyAsyncGen_Type16580931
Ref: 548016580931
Ref: c-api/gen c PyAsyncGen_New16581179
Ref: 548116581179
Ref: c-api/gen c PyAsyncGen_CheckExact16581721
Ref: 548216581721
Ref: Asynchronous Generator Objects-Footnote-116581960
Node: Deprecated API<5>16582002
Ref: c-api/gen deprecated-api16582112
Ref: 548316582112
Ref: c-api/gen c PyAsyncGenASend_CheckExact16582161
Ref: 548416582161
Node: Coroutine Objects<2>16582373
Ref: c-api/coro doc16582503
Ref: 548516582503
Ref: c-api/coro coro-objects16582503
Ref: 10d216582503
Ref: c-api/coro coroutine-objects16582503
Ref: 548616582503
Ref: c-api/coro translation-repo16582503
Ref: 548716582503
Ref: c-api/coro c PyCoroObject16582664
Ref: 548816582664
Ref: c-api/coro c PyCoro_Type16582745
Ref: 548916582745
Ref: c-api/coro c PyCoro_CheckExact16582858
Ref: 548a16582858
Ref: c-api/coro c PyCoro_New16583042
Ref: 548b16583042
Node: Context Variables Objects16583468
Ref: c-api/contextvars doc16583605
Ref: 548c16583605
Ref: c-api/contextvars context-variables-objects16583605
Ref: 548d16583605
Ref: c-api/contextvars contextvarsobjects16583605
Ref: cf216583605
Ref: c-api/contextvars translation-repo16583605
Ref: 548e16583605
Ref: c-api/contextvars contextvarsobjects-pointertype-change16583676
Ref: e2116583676
Ref: c-api/contextvars c PyContext16584222
Ref: 548f16584222
Ref: c-api/contextvars c PyContextVar16584337
Ref: 549016584337
Ref: c-api/contextvars c PyContextToken16584459
Ref: 549116584459
Ref: c-api/contextvars c PyContext_Type16584577
Ref: 549216584577
Ref: c-api/contextvars c PyContextVar_Type16584690
Ref: 549316584690
Ref: c-api/contextvars c PyContextToken_Type16584815
Ref: 549416584815
Ref: c-api/contextvars c PyContext_CheckExact16584968
Ref: 549516584968
Ref: c-api/contextvars c PyContextVar_CheckExact16585154
Ref: 549616585154
Ref: c-api/contextvars c PyContextToken_CheckExact16585346
Ref: 549716585346
Ref: c-api/contextvars c PyContext_New16585580
Ref: 549816585580
Ref: c-api/contextvars c PyContext_Copy16585772
Ref: 549916585772
Ref: c-api/contextvars c PyContext_CopyCurrent16586002
Ref: 549a16586002
Ref: c-api/contextvars c PyContext_Enter16586225
Ref: 549b16586225
Ref: c-api/contextvars c PyContext_Exit16586398
Ref: 549c16586398
Ref: c-api/contextvars c PyContext_AddWatcher16586627
Ref: 197a16586627
Ref: c-api/contextvars c PyContext_ClearWatcher16587011
Ref: 197b16587011
Ref: c-api/contextvars c PyContextEvent16587377
Ref: 549d16587377
Ref: c-api/contextvars c PyContext_WatchCallback16587772
Ref: 549e16587772
Ref: c-api/contextvars c PyContextVar_New16588690
Ref: 549f16588690
Ref: c-api/contextvars c PyContextVar_Get16589126
Ref: 54a016589126
Ref: c-api/contextvars c PyContextVar_Set16589749
Ref: 54a116589749
Ref: c-api/contextvars c PyContextVar_Reset16590047
Ref: 54a216590047
Ref: Context Variables Objects-Footnote-116590383
Node: Objects for Type Hinting16590448
Ref: c-api/typehints doc16590556
Ref: 54a316590556
Ref: c-api/typehints objects-for-type-hinting16590556
Ref: 54a416590556
Ref: c-api/typehints translation-repo16590556
Ref: 54a516590556
Ref: c-api/typehints typehintobjects16590556
Ref: 54a616590556
Ref: c-api/typehints c Py_GenericAlias16590801
Ref: 510316590801
Ref: c-api/typehints c Py_GenericAliasType16592188
Ref: 510416592188
Node: C API for extension modules16592476
Ref: c-api/concrete c-api-for-extension-modules16592584
Ref: 54a716592584
Node: Curses C API16592774
Ref: c-api/curses doc16592872
Ref: 54a816592872
Ref: c-api/curses curses-c-api16592872
Ref: 54a916592872
Ref: c-api/curses c import_curses16593363
Ref: 54aa16593363
Ref: c-api/curses c PyCurses_API16593835
Ref: 54ab16593835
Ref: c-api/curses c PyCurses_API_pointers16594793
Ref: 54b016594793
Ref: c-api/curses c PyCursesWindow_Type16594969
Ref: 54ac16594969
Ref: c-api/curses c PyCursesWindow_Check16595113
Ref: 54b116595113
Ref: c-api/curses c PyCursesSetupTermCalled16595444
Ref: 54ad16595444
Ref: c-api/curses c PyCursesInitialised16595851
Ref: 54ae16595851
Ref: c-api/curses c PyCursesInitialisedColor16596248
Ref: 54af16596248
Node: Internal data16596667
Ref: c-api/curses internal-data16596793
Ref: 54b216596793
Ref: c-api/curses c PyCurses_CAPSULE_NAME16596926
Ref: 54b316596926
Node: DateTime Objects<2>16597111
Ref: c-api/datetime doc16597241
Ref: 54b416597241
Ref: c-api/datetime datetime-objects16597241
Ref: 54b516597241
Ref: c-api/datetime datetimeobjects16597241
Ref: 524516597241
Ref: c-api/datetime translation-repo16597241
Ref: 54b616597241
Ref: c-api/datetime c PyDateTime_IMPORT16597774
Ref: 54b716597774
Ref: c-api/datetime c PyDateTime_CAPI16598233
Ref: 54b916598233
Ref: c-api/datetime c PyDateTimeAPI16598471
Ref: 54b816598471
Ref: c-api/datetime c PyDateTime_Date16598688
Ref: 54ba16598688
Ref: c-api/datetime c PyDateTime_DateTime16598803
Ref: 54bb16598803
Ref: c-api/datetime c PyDateTime_Time16598926
Ref: 54bc16598926
Ref: c-api/datetime c PyDateTime_Delta16599041
Ref: 54bd16599041
Ref: c-api/datetime c PyDateTime_DateType16599179
Ref: 54be16599179
Ref: c-api/datetime c PyDateTime_DateTimeType16599405
Ref: 54bf16599405
Ref: c-api/datetime c PyDateTime_TimeType16599643
Ref: 54c016599643
Ref: c-api/datetime c PyDateTime_DeltaType16599869
Ref: 54c116599869
Ref: c-api/datetime c PyDateTime_TZInfoType16600143
Ref: 54c216600143
Ref: c-api/datetime c PyDateTime_TimeZone_UTC16600423
Ref: dbe16600423
Ref: c-api/datetime c PyDate_Check16600649
Ref: 54c316600649
Ref: c-api/datetime c PyDate_CheckExact16600883
Ref: 54c416600883
Ref: c-api/datetime c PyDateTime_Check16601073
Ref: 54c516601073
Ref: c-api/datetime c PyDateTime_CheckExact16601319
Ref: 54c616601319
Ref: c-api/datetime c PyTime_Check16601517
Ref: 54c716601517
Ref: c-api/datetime c PyTime_CheckExact16601751
Ref: 54c816601751
Ref: c-api/datetime c PyDelta_Check16601941
Ref: 54c916601941
Ref: c-api/datetime c PyDelta_CheckExact16602177
Ref: 54ca16602177
Ref: c-api/datetime c PyTZInfo_Check16602369
Ref: 54cb16602369
Ref: c-api/datetime c PyTZInfo_CheckExact16602608
Ref: 54cc16602608
Ref: c-api/datetime c PyDate_FromDate16602829
Ref: 54cd16602829
Ref: c-api/datetime c PyDateTime_FromDateAndTime16603058
Ref: 54ce16603058
Ref: c-api/datetime c PyDateTime_FromDateAndTimeAndFold16603399
Ref: 54cf16603399
Ref: c-api/datetime c PyTime_FromTime16603791
Ref: 54d016603791
Ref: c-api/datetime c PyTime_FromTimeAndFold16604059
Ref: 54d116604059
Ref: c-api/datetime c PyDelta_FromDSU16604378
Ref: 54d216604378
Ref: c-api/datetime c PyTimeZone_FromOffset16604817
Ref: dbc16604817
Ref: c-api/datetime c PyTimeZone_FromOffsetAndName16605105
Ref: dbd16605105
Ref: c-api/datetime c PyDateTime_GET_YEAR16605673
Ref: 54d316605673
Ref: c-api/datetime c PyDateTime_GET_MONTH16605777
Ref: 54d416605777
Ref: c-api/datetime c PyDateTime_GET_DAY16605893
Ref: 54d516605893
Ref: c-api/datetime c PyDateTime_DATE_GET_HOUR16606213
Ref: 54d616606213
Ref: c-api/datetime c PyDateTime_DATE_GET_MINUTE16606336
Ref: 54d716606336
Ref: c-api/datetime c PyDateTime_DATE_GET_SECOND16606463
Ref: 54d816606463
Ref: c-api/datetime c PyDateTime_DATE_GET_MICROSECOND16606590
Ref: 54d916606590
Ref: c-api/datetime c PyDateTime_DATE_GET_FOLD16606741
Ref: 54da16606741
Ref: c-api/datetime c PyDateTime_DATE_GET_TZINFO16606891
Ref: a9716606891
Ref: c-api/datetime c PyDateTime_TIME_GET_HOUR16607272
Ref: 54db16607272
Ref: c-api/datetime c PyDateTime_TIME_GET_MINUTE16607391
Ref: 54dc16607391
Ref: c-api/datetime c PyDateTime_TIME_GET_SECOND16607514
Ref: 54dd16607514
Ref: c-api/datetime c PyDateTime_TIME_GET_MICROSECOND16607637
Ref: 54de16607637
Ref: c-api/datetime c PyDateTime_TIME_GET_FOLD16607774
Ref: 54df16607774
Ref: c-api/datetime c PyDateTime_TIME_GET_TZINFO16607920
Ref: a9816607920
Ref: c-api/datetime c PyDateTime_DELTA_GET_DAYS16608304
Ref: 54e016608304
Ref: c-api/datetime c PyDateTime_DELTA_GET_SECONDS16608474
Ref: 54e116608474
Ref: c-api/datetime c PyDateTime_DELTA_GET_MICROSECONDS16608642
Ref: 54e216608642
Ref: c-api/datetime c PyDateTime_FromTimestamp16608895
Ref: 54e316608895
Ref: c-api/datetime c PyDate_FromTimestamp16609202
Ref: 1dd916609202
Node: Internal data<2>16609492
Ref: c-api/datetime internal-data16609600
Ref: 54e416609600
Ref: c-api/datetime c PyDateTime_CAPSULE_NAME16609733
Ref: 54e516609733
Node: Initialization Finalization and Threads16609926
Ref: c-api/init doc16610106
Ref: 54e616610106
Ref: c-api/init initialization16610106
Ref: 54e716610106
Ref: c-api/init initialization-finalization-and-threads16610106
Ref: 54e816610106
Ref: c-api/init translation-repo16610106
Ref: 54e916610106
Node: Before Python Initialization16610794
Ref: c-api/init before-python-initialization16610937
Ref: 54ea16610937
Ref: c-api/init pre-init-safe16610937
Ref: dc016610937
Node: Global configuration variables16613616
Ref: c-api/init global-conf-vars16613811
Ref: 54eb16613811
Ref: c-api/init global-configuration-variables16613811
Ref: 54ef16613811
Ref: c-api/init c Py_BytesWarningFlag16614285
Ref: 40616614285
Ref: c-api/init c Py_DebugFlag16614818
Ref: 3f816614818
Ref: c-api/init c Py_DontWriteBytecodeFlag16615298
Ref: 40c16615298
Ref: c-api/init c Py_FrozenFlag16615817
Ref: 40816615817
Ref: c-api/init c Py_HashRandomizationFlag16616291
Ref: 41216616291
Ref: c-api/init c Py_IgnoreEnvironmentFlag16616870
Ref: 40a16616870
Ref: c-api/init c Py_InspectFlag16617364
Ref: 40016617364
Ref: c-api/init c Py_InteractiveFlag16617980
Ref: 3fe16617980
Ref: c-api/init c Py_IsolatedFlag16618310
Ref: 41516618310
Ref: c-api/init c Py_LegacyWindowsFSEncodingFlag16618829
Ref: 41716618829
Ref: c-api/init c Py_LegacyWindowsStdioFlag16619591
Ref: 41916619591
Ref: c-api/init c Py_NoSiteFlag16620236
Ref: 40416620236
Ref: c-api/init c Py_NoUserSiteDirectory16620862
Ref: 40e16620862
Ref: c-api/init c Py_OptimizeFlag16621382
Ref: 40216621382
Ref: c-api/init c Py_QuietFlag16621777
Ref: 3fc16621777
Ref: c-api/init c Py_UnbufferedStdioFlag16622211
Ref: 41016622211
Ref: c-api/init c Py_VerboseFlag16622672
Ref: 3fa16622672
Ref: Global configuration variables-Footnote-116623407
Ref: Global configuration variables-Footnote-216623449
Node: Initializing and finalizing the interpreter16623491
Ref: c-api/init initializing-and-finalizing-the-interpreter16623681
Ref: 54f016623681
Ref: c-api/init c Py_Initialize16623784
Ref: 46016623784
Ref: c-api/init c Py_InitializeEx16624942
Ref: 510b16624942
Ref: c-api/init c Py_InitializeFromConfig16625417
Ref: 3f616625417
Ref: c-api/init c Py_IsInitialized16625856
Ref: 4f2916625856
Ref: c-api/init c Py_IsFinalizing16626163
Ref: 5fd16626163
Ref: c-api/init c Py_FinalizeEx16626421
Ref: f1316626421
Ref: c-api/init c Py_Finalize16629625
Ref: 45f16629625
Ref: c-api/init c Py_BytesMain16629819
Ref: bba16629819
Ref: c-api/init c Py_Main16630149
Ref: e2016630149
Ref: c-api/init c Py_RunMain16632506
Ref: bbe16632506
Ref: c-api/init c PyUnstable_AtExit16634079
Ref: 18e216634079
Node: Process-wide parameters16634691
Ref: c-api/init process-wide-parameters16634895
Ref: 54f616634895
Ref: c-api/init c Py_SetProgramName16634958
Ref: 199e16634958
Ref: c-api/init c Py_GetProgramName16636157
Ref: 3ee16636157
Ref: c-api/init c Py_GetPrefix16636821
Ref: 3e516636821
Ref: c-api/init c Py_GetExecPrefix16638163
Ref: 3e916638163
Ref: c-api/init c Py_GetProgramFullPath16640922
Ref: 3ec16640922
Ref: c-api/init c Py_GetPath16641784
Ref: 3e316641784
Ref: c-api/init c Py_GetVersion16642919
Ref: 510916642919
Ref: c-api/init c Py_GetPlatform16643564
Ref: 510716643564
Ref: c-api/init c Py_GetCopyright16644194
Ref: 510616644194
Ref: c-api/init c Py_GetCompiler16644614
Ref: 510516644614
Ref: c-api/init c Py_GetBuildInfo16645039
Ref: 163916645039
Ref: c-api/init c PySys_SetArgvEx16645491
Ref: 199f16645491
Ref: c-api/init c PySys_SetArgv16647967
Ref: 19a016647967
Ref: c-api/init c Py_SetPythonHome16648856
Ref: 199d16648856
Ref: c-api/init c Py_GetPythonHome16649725
Ref: 3ef16649725
Ref: Process-wide parameters-Footnote-116650422
Node: Thread State and the Global Interpreter Lock16650477
Ref: c-api/init thread-state-and-the-global-interpreter-lock16650661
Ref: 54f716650661
Ref: c-api/init threads16650661
Ref: 54f816650661
Node: Detaching the thread state from extension code16653227
Ref: c-api/init detaching-the-thread-state-from-extension-code16653389
Ref: 54f916653389
Node: Non-Python created threads16655869
Ref: c-api/init gilstate16656088
Ref: 54fa16656088
Ref: c-api/init non-python-created-threads16656088
Ref: 54fb16656088
Node: Supporting subinterpreters in non-Python threads16658004
Ref: c-api/init supporting-subinterpreters-in-non-python-threads16658196
Ref: 54fc16658196
Node: Cautions about fork16659274
Ref: c-api/init cautions-about-fork16659479
Ref: 54fd16659479
Ref: c-api/init fork-and-threads16659479
Ref: 51f816659479
Node: Cautions regarding runtime finalization16661412
Ref: c-api/init cautions-regarding-runtime-finalization16661583
Ref: 54fe16661583
Ref: c-api/init id116661583
Ref: 54ff16661583
Node: High-level API16663158
Ref: c-api/init high-level-api16663323
Ref: 550016663323
Ref: c-api/init c PyInterpreterState16663499
Ref: c-api/init c PyThreadState16664310
Ref: 99116664310
Ref: c-api/init c PyThreadState interp16664517
Ref: 550216664517
Ref: c-api/init c PyEval_InitThreads16664622
Ref: 19a116664622
Ref: c-api/init c PyEval_SaveThread16665212
Ref: 64716665212
Ref: c-api/init c PyEval_RestoreThread16665458
Ref: 64816665458
Ref: c-api/init c PyThreadState_Get16666223
Ref: 61516666223
Ref: c-api/init c PyThreadState_GetUnchecked16666650
Ref: 42316666650
Ref: c-api/init c PyThreadState_Swap16667036
Ref: 509c16667036
Ref: c-api/init c PyGILState_STATE16667801
Ref: 500616667801
Ref: c-api/init c PyGILState_STATE PyGILState_LOCKED16668002
Ref: 550316668002
Ref: c-api/init c PyGILState_STATE PyGILState_UNLOCKED16668151
Ref: 550416668151
Ref: c-api/init c PyGILState_Ensure16668298
Ref: 64a16668298
Ref: c-api/init c PyGILState_Release16670203
Ref: 64b16670203
Ref: c-api/init c PyGILState_GetThisThreadState16670727
Ref: 500516670727
Ref: c-api/init c PyGILState_Check16671505
Ref: 550516671505
Ref: c-api/init c Py_BEGIN_ALLOW_THREADS16672493
Ref: 4ea616672493
Ref: c-api/init c Py_END_ALLOW_THREADS16672841
Ref: c8116672841
Ref: c-api/init c Py_BLOCK_THREADS16673166
Ref: 510116673166
Ref: c-api/init c Py_UNBLOCK_THREADS16673388
Ref: 512116673388
Ref: High-level API-Footnote-116673681
Node: Low-level API16673723
Ref: c-api/init low-level-api16673840
Ref: 550616673840
Ref: c-api/init c PyInterpreterState_New16674109
Ref: 473c16674109
Ref: c-api/init c PyInterpreterState_Clear16674531
Ref: 473b16674531
Ref: c-api/init c PyInterpreterState_Delete16674905
Ref: 501316674905
Ref: c-api/init c PyThreadState_New16675289
Ref: 509b16675289
Ref: c-api/init c PyThreadState_Clear16675573
Ref: 197916675573
Ref: c-api/init c PyThreadState_Delete16676069
Ref: 1d7116676069
Ref: c-api/init c PyThreadState_DeleteCurrent16676389
Ref: 1da016676389
Ref: c-api/init c PyThreadState_GetFrame16676703
Ref: 99216676703
Ref: c-api/init c PyThreadState_GetID16677183
Ref: b6c16677183
Ref: c-api/init c PyThreadState_GetInterpreter16677517
Ref: b6b16677517
Ref: c-api/init c PyThreadState_EnterTracing16677856
Ref: 95b16677856
Ref: c-api/init c PyThreadState_LeaveTracing16678115
Ref: 95c16678115
Ref: c-api/init c PyUnstable_ThreadState_SetStackProtection16678459
Ref: 46616678459
Ref: c-api/init c PyUnstable_ThreadState_ResetStackProtection16680416
Ref: 46716680416
Ref: c-api/init c PyInterpreterState_Get16681424
Ref: 64c16681424
Ref: c-api/init c PyInterpreterState_GetID16681739
Ref: dc116681739
Ref: c-api/init c PyInterpreterState_GetDict16682114
Ref: 501416682114
Ref: c-api/init c _PyFrameEvalFunction16682859
Ref: 97b16682859
Ref: c-api/init c _PyInterpreterState_GetEvalFrameFunc16683424
Ref: 1d5f16683424
Ref: c-api/init c _PyInterpreterState_SetEvalFrameFunc16683700
Ref: 1d6016683700
Ref: c-api/init c PyThreadState_GetDict16683971
Ref: 509a16683971
Ref: c-api/init c PyThreadState_SetAsyncExc16684549
Ref: dbf16684549
Ref: c-api/init c PyEval_AcquireThread16685403
Ref: 64916685403
Ref: c-api/init c PyEval_ReleaseThread16686578
Ref: 4fb616686578
Ref: Low-level API-Footnote-116687108
Ref: Low-level API-Footnote-216687202
Ref: Low-level API-Footnote-316687296
Ref: Low-level API-Footnote-416687338
Node: Sub-interpreter support16687380
Ref: c-api/init id316687567
Ref: 550716687567
Ref: c-api/init sub-interpreter-support16687567
Ref: 16316687567
Ref: c-api/init c PyInterpreterConfig16688498
Ref: 78f16688498
Ref: c-api/init c PyInterpreterConfig use_main_obmalloc16688785
Ref: 48ff16688785
Ref: c-api/init c PyInterpreterConfig allow_fork16689225
Ref: 550c16689225
Ref: c-api/init c PyInterpreterConfig allow_exec16689559
Ref: 550d16689559
Ref: c-api/init c PyInterpreterConfig allow_threads16689953
Ref: 550e16689953
Ref: c-api/init c PyInterpreterConfig allow_daemon_threads16690144
Ref: 550f16690144
Ref: c-api/init c PyInterpreterConfig check_multi_interp_extensions16690428
Ref: 550916690428
Ref: c-api/init c PyInterpreterConfig gil16690951
Ref: 550a16690951
Ref: c-api/init c PyInterpreterConfig_DEFAULT_GIL16691099
Ref: 551016691099
Ref: c-api/init c PyInterpreterConfig_SHARED_GIL16691259
Ref: 551116691259
Ref: c-api/init c PyInterpreterConfig_OWN_GIL16691372
Ref: 550b16691372
Ref: c-api/init c Py_NewInterpreterFromConfig16691623
Ref: 68a16691623
Ref: c-api/init c Py_NewInterpreter16696211
Ref: 1b1916696211
Ref: c-api/init c Py_EndInterpreter16696686
Ref: 182d16696686
Ref: Sub-interpreter support-Footnote-116697317
Node: A Per-Interpreter GIL16697359
Ref: c-api/init a-per-interpreter-gil16697465
Ref: 551316697465
Ref: c-api/init per-interpreter-gil16697465
Ref: 550116697465
Ref: A Per-Interpreter GIL-Footnote-116699527
Ref: A Per-Interpreter GIL-Footnote-216699569
Node: Bugs and caveats16699611
Ref: c-api/init bugs-and-caveats16699717
Ref: 551216699717
Node: Asynchronous Notifications16701325
Ref: c-api/init asynchronous-notifications16701489
Ref: 551416701489
Ref: c-api/init c Py_AddPendingCall16701736
Ref: b7a16701736
Ref: c-api/init c Py_MakePendingCalls16704015
Ref: 510c16704015
Node: Profiling and Tracing16704627
Ref: c-api/init profiling16704785
Ref: 551516704785
Ref: c-api/init profiling-and-tracing16704785
Ref: 551616704785
Ref: c-api/init c Py_tracefunc16705466
Ref: 551716705466
Ref: c-api/init c PyTrace_CALL16707815
Ref: 551816707815
Ref: c-api/init c PyTrace_EXCEPTION16708206
Ref: 551916708206
Ref: c-api/init c PyTrace_LINE16708817
Ref: 551a16708817
Ref: c-api/init c PyTrace_RETURN16709120
Ref: 551b16709120
Ref: c-api/init c PyTrace_C_CALL16709274
Ref: 551c16709274
Ref: c-api/init c PyTrace_C_EXCEPTION16709437
Ref: 551d16709437
Ref: c-api/init c PyTrace_C_RETURN16709607
Ref: 551e16709607
Ref: c-api/init c PyTrace_OPCODE16709763
Ref: 551f16709763
Ref: c-api/init c PyEval_SetProfile16710104
Ref: 170416710104
Ref: c-api/init c PyEval_SetProfileAllThreads16710812
Ref: 78216710812
Ref: c-api/init c PyEval_SetTrace16711342
Ref: 66316711342
Ref: c-api/init c PyEval_SetTraceAllThreads16712039
Ref: 66416712039
Node: Reference tracing16712554
Ref: c-api/init reference-tracing16712711
Ref: 552016712711
Ref: c-api/init c PyRefTracer16712786
Ref: 552116712786
Ref: c-api/init c PyRefTracer_CREATE16713348
Ref: 552216713348
Ref: c-api/init c PyRefTracer_DESTROY16713513
Ref: 552316713513
Ref: c-api/init c PyRefTracer_SetTracer16713681
Ref: 61016713681
Ref: c-api/init c PyRefTracer_GetTracer16714538
Ref: 61116714538
Node: Advanced Debugger Support16715027
Ref: c-api/init advanced-debugger-support16715191
Ref: 552416715191
Ref: c-api/init advanced-debugging16715191
Ref: 552516715191
Ref: c-api/init c PyInterpreterState_Head16715335
Ref: 170616715335
Ref: c-api/init c PyInterpreterState_Main16715513
Ref: 550816715513
Ref: c-api/init c PyInterpreterState_Next16715647
Ref: 170716715647
Ref: c-api/init c PyInterpreterState_ThreadHead16715861
Ref: 170816715861
Ref: c-api/init c PyThreadState_Next16716115
Ref: 170916716115
Node: Thread Local Storage Support16716374
Ref: c-api/init thread-local-storage16716550
Ref: 552616716550
Ref: c-api/init thread-local-storage-support16716550
Ref: 552716716550
Node: Thread Specific Storage TSS API16717697
Ref: c-api/init thread-specific-storage-api16717830
Ref: cd716717830
Ref: c-api/init thread-specific-storage-tss-api16717830
Ref: 552816717830
Ref: c-api/init c Py_tss_t16718220
Ref: cd816718220
Ref: c-api/init c Py_tss_NEEDS_INIT16718664
Ref: 552916718664
Ref: Thread Specific Storage TSS API-Footnote-116718940
Node: Dynamic Allocation16718982
Ref: c-api/init dynamic-allocation16719084
Ref: 552a16719084
Ref: c-api/init c PyThread_tss_alloc16719366
Ref: 43816719366
Ref: c-api/init c PyThread_tss_free16719660
Ref: 43a16719660
Node: Methods16720143
Ref: c-api/init methods16720245
Ref: 552b16720245
Ref: c-api/init c PyThread_tss_is_created16720551
Ref: 50a916720551
Ref: c-api/init c PyThread_tss_create16720802
Ref: 50a816720802
Ref: c-api/init c PyThread_tss_delete16721281
Ref: 44016721281
Ref: c-api/init c PyThread_tss_set16721775
Ref: 43c16721775
Ref: c-api/init c PyThread_tss_get16722094
Ref: 43e16722094
Node: Thread Local Storage TLS API16722386
Ref: c-api/init thread-local-storage-api16722519
Ref: cd616722519
Ref: c-api/init thread-local-storage-tls-api16722519
Ref: 552c16722519
Ref: c-api/init c PyThread_create_key16723144
Ref: 43716723144
Ref: c-api/init c PyThread_delete_key16723230
Ref: 43916723230
Ref: c-api/init c PyThread_set_key_value16723324
Ref: 43b16723324
Ref: c-api/init c PyThread_get_key_value16723433
Ref: 43d16723433
Ref: c-api/init c PyThread_delete_key_value16723531
Ref: 43f16723531
Ref: c-api/init c PyThread_ReInitTLS16723631
Ref: 44116723631
Node: Synchronization Primitives<2>16723717
Ref: c-api/init synchronization-primitives16723896
Ref: 552d16723896
Ref: c-api/init c PyMutex16724018
Ref: 48516724018
Ref: c-api/init c PyMutex_Lock16724640
Ref: 5d016724640
Ref: c-api/init c PyMutex_Unlock16724951
Ref: 5d116724951
Ref: c-api/init c PyMutex_IsLocked16725139
Ref: 46316725139
Node: Python Critical Section API16725601
Ref: c-api/init id416725722
Ref: 552e16725722
Ref: c-api/init python-critical-section-api16725722
Ref: 552f16725722
Ref: c-api/init c Py_BEGIN_CRITICAL_SECTION16728592
Ref: 538416728592
Ref: c-api/init c Py_BEGIN_CRITICAL_SECTION_MUTEX16728990
Ref: 553116728990
Ref: c-api/init c Py_END_CRITICAL_SECTION16729515
Ref: 553216729515
Ref: c-api/init c Py_BEGIN_CRITICAL_SECTION216729826
Ref: 553016729826
Ref: c-api/init c Py_BEGIN_CRITICAL_SECTION2_MUTEX16730364
Ref: 553316730364
Ref: c-api/init c Py_END_CRITICAL_SECTION216730919
Ref: 553416730919
Node: Legacy Locking APIs16731234
Ref: c-api/init legacy-locking-apis16731355
Ref: 553516731355
Ref: c-api/init c PyThread_type_lock16731593
Ref: 553616731593
Ref: c-api/init c PyLockStatus16731674
Ref: 553716731674
Ref: c-api/init c PY_LOCK_FAILURE16731758
Ref: 553816731758
Ref: c-api/init c PY_LOCK_ACQUIRED16731849
Ref: 553916731849
Ref: c-api/init c PY_LOCK_INTR16731949
Ref: 553a16731949
Ref: c-api/init c PyThread_allocate_lock16732047
Ref: 50a016732047
Ref: c-api/init c PyThread_free_lock16732575
Ref: 50a216732575
Ref: c-api/init c PyThread_acquire_lock_timed16732850
Ref: 509f16732850
Ref: c-api/init c PyThread_acquire_lock16733847
Ref: 509e16733847
Ref: c-api/init c PyThread_release_lock16734607
Ref: 50a616734607
Node: Operating System Thread APIs16734887
Ref: c-api/init operating-system-thread-apis16735029
Ref: 553b16735029
Ref: c-api/init c PYTHREAD_INVALID_THREAD_ID16735104
Ref: 553c16735104
Ref: c-api/init c PyThread_start_new_thread16735255
Ref: 1e1316735255
Ref: c-api/init c PyThread_get_thread_ident16735811
Ref: 50a416735811
Ref: c-api/init c PyThread_GetInfo16736181
Ref: 509d16736181
Ref: c-api/init c PY_HAVE_THREAD_NATIVE_ID16736727
Ref: 553d16736727
Ref: c-api/init c PyThread_get_thread_native_id16736838
Ref: 1b8a16736838
Ref: c-api/init c PyThread_exit_thread16737428
Ref: 50a116737428
Ref: c-api/init c PyThread_init_thread16738450
Ref: 50a516738450
Ref: c-api/init c PyThread_set_stacksize16738693
Ref: 50a716738693
Ref: c-api/init c PyThread_get_stacksize16739136
Ref: 50a316739136
Ref: Operating System Thread APIs-Footnote-116739474
Node: Python Initialization Configuration16739526
Ref: c-api/init_config doc16739701
Ref: 553e16739701
Ref: c-api/init_config init-config16739701
Ref: 64616739701
Ref: c-api/init_config python-initialization-configuration16739701
Ref: 553f16739701
Ref: c-api/init_config translation-repo16739701
Ref: 554016739701
Node: PyInitConfig C API16739970
Ref: c-api/init_config pyinitconfig-api16740090
Ref: 37916740090
Ref: c-api/init_config pyinitconfig-c-api16740090
Ref: 554116740090
Ref: PyInitConfig C API-Footnote-116740634
Node: Example<17>16740676
Ref: c-api/init_config example16740764
Ref: 554216740764
Node: Create Config16741951
Ref: c-api/init_config create-config16742062
Ref: 554316742062
Ref: c-api/init_config c PyInitConfig16742109
Ref: 554416742109
Ref: c-api/init_config c PyInitConfig_Create16742207
Ref: 38716742207
Ref: c-api/init_config c PyInitConfig_Free16742501
Ref: 38816742501
Node: Error Handling16742688
Ref: c-api/init_config error-handling16742799
Ref: 554616742799
Ref: c-api/init_config c PyInitConfig_GetError16742848
Ref: 38a16742848
Ref: c-api/init_config c PyInitConfig_GetExitCode16743421
Ref: 38b16743421
Node: Get Options16744015
Ref: c-api/init_config get-options16744124
Ref: 554716744124
Ref: c-api/init_config c PyInitConfig_HasOption16744307
Ref: 38f16744307
Ref: c-api/init_config c PyInitConfig_GetInt16744535
Ref: 38c16744535
Ref: c-api/init_config c PyInitConfig_GetStr16744808
Ref: 38d16744808
Ref: c-api/init_config c PyInitConfig_GetStrList16745330
Ref: 38e16745330
Ref: c-api/init_config c PyInitConfig_FreeStrList16745805
Ref: 38916745805
Node: Set Options16745976
Ref: c-api/init_config set-options16746077
Ref: 554916746077
Ref: c-api/init_config c PyInitConfig_SetInt16746536
Ref: 39016746536
Ref: c-api/init_config c PyInitConfig_SetStr16746790
Ref: 39116746790
Ref: c-api/init_config c PyInitConfig_SetStrList16747118
Ref: 39216747118
Node: Module16747487
Ref: c-api/init_config module16747594
Ref: 554a16747594
Ref: c-api/init_config c PyInitConfig_AddModule16747627
Ref: 37b16747627
Node: Initialize Python16748294
Ref: c-api/init_config initialize-python16748381
Ref: 554b16748381
Ref: c-api/init_config c Py_InitializeFromInitConfig16748436
Ref: 38616748436
Node: Configuration Options16748837
Ref: c-api/init_config configuration-options16748998
Ref: 554c16748998
Ref: c-api/init_config pyinitconfig-opts16748998
Ref: 554816748998
Node: Runtime Python configuration API16769531
Ref: c-api/init_config runtime-python-configuration-api16769688
Ref: 556b16769688
Ref: c-api/init_config c PyConfig_Get16770182
Ref: 37c16770182
Ref: c-api/init_config c PyConfig_GetInt16770835
Ref: 38416770835
Ref: c-api/init_config c PyConfig_Names16771102
Ref: 38516771102
Ref: c-api/init_config c PyConfig_Set16771527
Ref: 37d16771527
Node: PyConfig C API16772300
Ref: c-api/init_config pyconfig-api16772450
Ref: 37a16772450
Ref: c-api/init_config pyconfig-c-api16772450
Ref: 556c16772450
Ref: PyConfig C API-Footnote-116773793
Node: Example<18>16773835
Ref: c-api/init_config id116773922
Ref: 556d16773922
Node: PyWideStringList16774935
Ref: c-api/init_config pywidestringlist16775039
Ref: 556e16775039
Ref: c-api/init_config c PyWideStringList16775092
Ref: ba716775092
Ref: c-api/init_config c PyWideStringList_Append16775287
Ref: bb816775287
Ref: c-api/init_config c PyWideStringList_Insert16775515
Ref: bb916775515
Ref: c-api/init_config c PyWideStringList length16775974
Ref: 556f16775974
Ref: c-api/init_config c PyWideStringList items16776048
Ref: 557016776048
Node: PyStatus16776107
Ref: c-api/init_config pystatus16776211
Ref: 557116776211
Ref: c-api/init_config c PyStatus16776248
Ref: ba616776248
Ref: c-api/init_config c PyStatus exitcode16776471
Ref: 557216776471
Ref: c-api/init_config c PyStatus err_msg16776560
Ref: 557316776560
Ref: c-api/init_config c PyStatus func16776626
Ref: 557416776626
Ref: c-api/init_config c PyStatus_Ok16776774
Ref: bb716776774
Ref: c-api/init_config c PyStatus_Error16776856
Ref: bb116776856
Ref: c-api/init_config c PyStatus_NoMemory16777044
Ref: bb616777044
Ref: c-api/init_config c PyStatus_Exit16777166
Ref: bb316777166
Ref: c-api/init_config c PyStatus_Exception16777327
Ref: bb216777327
Ref: c-api/init_config c PyStatus_IsError16777558
Ref: bb416777558
Ref: c-api/init_config c PyStatus_IsExit16777654
Ref: bb516777654
Ref: c-api/init_config c Py_ExitStatusException16777748
Ref: bbb16777748
Node: PyPreConfig16778689
Ref: c-api/init_config pypreconfig16778814
Ref: 557516778814
Ref: c-api/init_config c PyPreConfig16778857
Ref: ba516778857
Ref: c-api/init_config c PyPreConfig_InitPythonConfig16778982
Ref: bb016778982
Ref: c-api/init_config c PyPreConfig_InitIsolatedConfig16779170
Ref: baf16779170
Ref: c-api/init_config c PyPreConfig allocator16779386
Ref: 554d16779386
Ref: c-api/init_config c PyPreConfig configure_locale16781173
Ref: 555616781173
Ref: c-api/init_config c PyPreConfig coerce_c_locale16781534
Ref: 555316781534
Ref: c-api/init_config c PyPreConfig coerce_c_locale_warn16781853
Ref: 555416781853
Ref: c-api/init_config c PyPreConfig dev_mode16782040
Ref: 557716782040
Ref: c-api/init_config c PyPreConfig isolated16782237
Ref: 557816782237
Ref: c-api/init_config c PyPreConfig legacy_windows_fs_encoding16782400
Ref: 41816782400
Ref: c-api/init_config c PyPreConfig parse_argv16782972
Ref: 557916782972
Ref: c-api/init_config c PyPreConfig use_environment16783357
Ref: 557a16783357
Ref: c-api/init_config c PyPreConfig utf8_mode16783576
Ref: 41d16783576
Node: Preinitialize Python with PyPreConfig16783987
Ref: c-api/init_config c-preinit16784112
Ref: 42af16784112
Ref: c-api/init_config preinitialize-python-with-pypreconfig16784112
Ref: 557b16784112
Ref: c-api/init_config c Py_PreInitialize16784605
Ref: 41e16784605
Ref: c-api/init_config c Py_PreInitializeFromBytesArgs16784805
Ref: bbd16784805
Ref: c-api/init_config c Py_PreInitializeFromArgs16785165
Ref: bbc16785165
Node: PyConfig16787102
Ref: c-api/init_config pyconfig16787244
Ref: 557c16787244
Ref: c-api/init_config c PyConfig16787281
Ref: 3f716787281
Ref: c-api/init_config c PyConfig_InitPythonConfig16787511
Ref: baa16787511
Ref: c-api/init_config c PyConfig_InitIsolatedConfig16787672
Ref: ba916787672
Ref: c-api/init_config c PyConfig_SetString16787837
Ref: bae16787837
Ref: c-api/init_config c PyConfig_SetBytesString16788109
Ref: bad16788109
Ref: c-api/init_config c PyConfig_SetArgv16788439
Ref: bab16788439
Ref: c-api/init_config c PyConfig_SetBytesArgv16788755
Ref: bac16788755
Ref: c-api/init_config c PyConfig_SetWideStringList16789124
Ref: 1db116789124
Ref: c-api/init_config c PyConfig_Read16789431
Ref: 99416789431
Ref: c-api/init_config c PyConfig_Clear16790811
Ref: ba816790811
Ref: c-api/init_config c PyConfig argv16791935
Ref: 3f116791935
Ref: c-api/init_config c PyConfig safe_path16792949
Ref: 97816792949
Ref: c-api/init_config c PyConfig base_exec_prefix16793827
Ref: 554e16793827
Ref: c-api/init_config c PyConfig base_executable16794072
Ref: 554f16794072
Ref: c-api/init_config c PyConfig base_prefix16794470
Ref: 555016794470
Ref: c-api/init_config c PyConfig buffered_stdio16794700
Ref: 41116794700
Ref: c-api/init_config c PyConfig bytes_warning16795113
Ref: 40716795113
Ref: c-api/init_config c PyConfig warn_default_encoding16795558
Ref: 556916795558
Ref: c-api/init_config c PyConfig code_debug_ranges16795870
Ref: 555216795870
Ref: c-api/init_config c PyConfig check_hash_pycs_mode16796343
Ref: 555116796343
Ref: c-api/init_config c PyConfig configure_c_stdio16797013
Ref: 555516797013
Ref: c-api/init_config c PyConfig dev_mode16797562
Ref: 555816797562
Ref: c-api/init_config c PyConfig dump_refs16797862
Ref: 555916797862
Ref: c-api/init_config c PyConfig dump_refs_file16798275
Ref: 555a16798275
Ref: c-api/init_config c PyConfig exec_prefix16798524
Ref: 555b16798524
Ref: c-api/init_config c PyConfig executable16798876
Ref: 64516798876
Ref: c-api/init_config c PyConfig faulthandler16799194
Ref: 555c16799194
Ref: c-api/init_config c PyConfig filesystem_encoding16799548
Ref: 41b16799548
Ref: c-api/init_config c PyConfig filesystem_errors16800775
Ref: 41c16800775
Ref: c-api/init_config c PyConfig use_frozen_modules16801444
Ref: 556816801444
Ref: c-api/init_config c PyConfig hash_seed16801717
Ref: 41416801717
Ref: c-api/init_config c PyConfig use_hash_seed16801761
Ref: 41316801761
Ref: c-api/init_config c PyConfig home16802168
Ref: 3f316802168
Ref: c-api/init_config c PyConfig import_time16802518
Ref: 555d16802518
Ref: c-api/init_config c PyConfig inspect16803002
Ref: 40116803002
Ref: c-api/init_config c PyConfig install_signal_handlers16803590
Ref: abd16803590
Ref: c-api/init_config c PyConfig interactive16803751
Ref: 3ff16803751
Ref: c-api/init_config c PyConfig int_max_str_digits16803955
Ref: 555e16803955
Ref: c-api/init_config c PyConfig cpu_count16804844
Ref: 555716804844
Ref: c-api/init_config c PyConfig isolated16805332
Ref: 41616805332
Ref: c-api/init_config c PyConfig legacy_windows_stdio16806333
Ref: 41a16806333
Ref: c-api/init_config c PyConfig malloc_stats16806930
Ref: 555f16806930
Ref: c-api/init_config c PyConfig platlibdir16807314
Ref: 1d0916807314
Ref: c-api/init_config c PyConfig pythonpath_env16808130
Ref: 557d16808130
Ref: c-api/init_config c PyConfig module_search_paths16808470
Ref: 64316808470
Ref: c-api/init_config c PyConfig module_search_paths_set16808539
Ref: 80616808539
Ref: c-api/init_config c PyConfig optimization_level16809064
Ref: 40316809064
Ref: c-api/init_config c PyConfig orig_argv16809559
Ref: a9616809559
Ref: c-api/init_config c PyConfig parse_argv16810231
Ref: 1cd916810231
Ref: c-api/init_config c PyConfig parser_debug16811135
Ref: 3f916811135
Ref: c-api/init_config c PyConfig pathconfig_warnings16811611
Ref: 40916811611
Ref: c-api/init_config c PyConfig prefix16812035
Ref: 556116812035
Ref: c-api/init_config c PyConfig program_name16812364
Ref: 3f216812364
Ref: c-api/init_config c PyConfig pycache_prefix16813096
Ref: 556216813096
Ref: c-api/init_config c PyConfig quiet16813558
Ref: 3fd16813558
Ref: c-api/init_config c PyConfig run_command16813824
Ref: 54f216813824
Ref: c-api/init_config c PyConfig run_filename16814001
Ref: 54f316814001
Ref: c-api/init_config c PyConfig run_module16814468
Ref: 54f416814468
Ref: c-api/init_config c PyConfig run_presite16814644
Ref: 556316814644
Ref: c-api/init_config c PyConfig show_ref_count16815135
Ref: 556416815135
Ref: c-api/init_config c PyConfig site_import16815490
Ref: 40516815490
Ref: c-api/init_config c PyConfig skip_source_first_line16816143
Ref: 556516816143
Ref: c-api/init_config c PyConfig stdio_encoding16816516
Ref: 64416816516
Ref: c-api/init_config c PyConfig stdio_errors16816560
Ref: 491016816560
Ref: c-api/init_config c PyConfig tracemalloc16817464
Ref: 556716817464
Ref: c-api/init_config c PyConfig perf_profiling16817817
Ref: 556016817817
Ref: c-api/init_config c PyConfig stdlib_dir16818633
Ref: 556616818633
Ref: c-api/init_config c PyConfig use_environment16818792
Ref: 40b16818792
Ref: c-api/init_config c PyConfig use_system_logger16819114
Ref: 225a16819114
Ref: c-api/init_config c PyConfig user_site_directory16819470
Ref: 40f16819470
Ref: c-api/init_config c PyConfig verbose16819865
Ref: 3fb16819865
Ref: c-api/init_config c PyConfig warnoptions16820473
Ref: 64116820473
Ref: c-api/init_config c PyConfig write_bytecode16821315
Ref: 40d16821315
Ref: c-api/init_config c PyConfig xoptions16821774
Ref: 64216821774
Ref: c-api/init_config c PyConfig _pystats16821963
Ref: 556a16821963
Ref: PyConfig-Footnote-116822638
Ref: PyConfig-Footnote-216822680
Node: Initialization with PyConfig16822722
Ref: c-api/init_config init-from-config16822849
Ref: 54f116822849
Ref: c-api/init_config initialization-with-pyconfig16822849
Ref: 557e16822849
Node: Isolated Configuration16826548
Ref: c-api/init_config init-isolated-conf16826687
Ref: 554516826687
Ref: c-api/init_config isolated-configuration16826687
Ref: 557f16826687
Node: Python Configuration16827458
Ref: c-api/init_config init-python-config16827594
Ref: 54f516827594
Ref: c-api/init_config python-configuration16827594
Ref: 558016827594
Ref: Python Configuration-Footnote-116828230
Ref: Python Configuration-Footnote-216828272
Node: Python Path Configuration16828314
Ref: c-api/init_config init-path-config16828419
Ref: aac16828419
Ref: c-api/init_config python-path-configuration16828419
Ref: 558116828419
Node: Py_GetArgcArgv16832770
Ref: c-api/init_config py-getargcargv16832918
Ref: 558216832918
Ref: c-api/init_config c Py_GetArgcArgv16832967
Ref: 1d2916832967
Node: Delaying main module execution16833168
Ref: c-api/init_config delaying-main-module-execution16833293
Ref: 558316833293
Node: Memory Management16833799
Ref: c-api/memory doc16833964
Ref: 558416833964
Ref: c-api/memory memory16833964
Ref: 557616833964
Ref: c-api/memory memory-management16833964
Ref: 558516833964
Ref: c-api/memory translation-repo16833964
Ref: 558616833964
Node: Overview<4>16834348
Ref: c-api/memory memoryoverview16834439
Ref: 558716834439
Ref: c-api/memory overview16834439
Ref: 558816834439
Node: Allocator Domains16838359
Ref: c-api/memory allocator-domains16838479
Ref: 558916838479
Ref: c-api/memory id116838530
Ref: 558a16838530
Node: Raw Memory Interface16840573
Ref: c-api/memory raw-memory-interface16840698
Ref: 559016840698
Ref: c-api/memory raw-memoryinterface16840698
Ref: 558c16840698
Ref: c-api/memory c PyMem_RawMalloc16841168
Ref: 63116841168
Ref: c-api/memory c PyMem_RawCalloc16841612
Ref: 63216841612
Ref: c-api/memory c PyMem_RawRealloc16842171
Ref: 63316842171
Ref: c-api/memory c PyMem_RawFree16842978
Ref: 63416842978
Node: Memory Interface16843447
Ref: c-api/memory memory-interface16843572
Ref: 559116843572
Ref: c-api/memory memoryinterface16843572
Ref: 558d16843572
Ref: c-api/memory c PyMem_Malloc16844107
Ref: e6216844107
Ref: c-api/memory c PyMem_Calloc16844525
Ref: 10af16844525
Ref: c-api/memory c PyMem_Realloc16845078
Ref: 123416845078
Ref: c-api/memory c PyMem_Free16845849
Ref: 164916845849
Ref: c-api/memory c PyMem_New16846386
Ref: 172b16846386
Ref: c-api/memory c PyMem_Resize16846621
Ref: 559216846621
Ref: c-api/memory c PyMem_Del16847069
Ref: 172c16847069
Node: Deprecated aliases<2>16847206
Ref: c-api/memory deprecated-aliases16847280
Ref: 559316847280
Ref: c-api/memory c PyMem_MALLOC16847808
Ref: 559416847808
Ref: c-api/memory c PyMem_NEW16848005
Ref: 559516848005
Ref: c-api/memory c PyMem_REALLOC16848198
Ref: 559616848198
Ref: c-api/memory c PyMem_RESIZE16848399
Ref: 559716848399
Ref: c-api/memory c PyMem_FREE16848578
Ref: 559816848578
Ref: c-api/memory c PyMem_DEL16848770
Ref: 559916848770
Node: Object allocators16849141
Ref: c-api/memory object-allocators16849271
Ref: 559a16849271
Ref: c-api/memory objectinterface16849271
Ref: 558e16849271
Ref: c-api/memory c PyObject_Malloc16849984
Ref: e6416849984
Ref: c-api/memory c PyObject_Calloc16850408
Ref: 10b016850408
Ref: c-api/memory c PyObject_Realloc16850967
Ref: 164a16850967
Ref: c-api/memory c PyObject_Free16851756
Ref: e6116851756
Node: Default Memory Allocators16852956
Ref: c-api/memory default-memory-allocators16853097
Ref: 212416853097
Ref: c-api/memory id216853097
Ref: 559c16853097
Node: Customize Memory Allocators16855593
Ref: c-api/memory customize-memory-allocators16855760
Ref: 559b16855760
Ref: c-api/memory id316855760
Ref: 559d16855760
Ref: c-api/memory c PyMemAllocatorEx16855854
Ref: 10d016855854
Ref: c-api/memory c PyMemAllocatorDomain16857699
Ref: 558b16857699
Ref: c-api/memory c PYMEM_DOMAIN_RAW16857797
Ref: 212516857797
Ref: c-api/memory c PYMEM_DOMAIN_MEM16858038
Ref: e6516858038
Ref: c-api/memory c PYMEM_DOMAIN_OBJ16858270
Ref: e6316858270
Ref: c-api/memory c PyMem_GetAllocator16858513
Ref: 54ed16858513
Ref: c-api/memory c PyMem_SetAllocator16858685
Ref: 7a916858685
Ref: c-api/memory c PyMem_SetupDebugHooks16860678
Ref: e6616860678
Node: Debug hooks on the Python memory allocators16860828
Ref: c-api/memory debug-hooks-on-the-python-memory-allocators16860992
Ref: 559e16860992
Ref: c-api/memory pymem-debug-hooks16860992
Ref: 212716860992
Node: The pymalloc allocator16866299
Ref: c-api/memory pymalloc16866458
Ref: f0d16866458
Ref: c-api/memory the-pymalloc-allocator16866458
Ref: 559f16866458
Node: Customize pymalloc Arena Allocator16867771
Ref: c-api/memory customize-pymalloc-arena-allocator16867864
Ref: 55a016867864
Ref: c-api/memory c PyObjectArenaAllocator16867976
Ref: 55a116867976
Ref: c-api/memory c PyObject_GetArenaAllocator16868985
Ref: 54ee16868985
Ref: c-api/memory c PyObject_SetArenaAllocator16869111
Ref: 54ec16869111
Node: The mimalloc allocator16869237
Ref: c-api/memory mimalloc16869370
Ref: 212616869370
Ref: c-api/memory the-mimalloc-allocator16869370
Ref: 55a216869370
Node: tracemalloc C API16869729
Ref: c-api/memory tracemalloc-c-api16869852
Ref: 55a316869852
Ref: c-api/memory c PyTraceMalloc_Track16869928
Ref: db116869928
Ref: c-api/memory c PyTraceMalloc_Untrack16870341
Ref: db216870341
Node: Examples<38>16870633
Ref: c-api/memory examples16870725
Ref: 55a416870725
Ref: c-api/memory memoryexamples16870725
Ref: 55a516870725
Node: Object Implementation Support16872639
Ref: c-api/objimpl doc16872791
Ref: 55a616872791
Ref: c-api/objimpl newtypes16872791
Ref: 55a716872791
Ref: c-api/objimpl object-implementation-support16872791
Ref: 55a816872791
Ref: c-api/objimpl translation-repo16872791
Ref: 55a916872791
Node: Allocating Objects on the Heap16873120
Ref: c-api/allocation doc16873242
Ref: 55aa16873242
Ref: c-api/allocation allocating-objects16873242
Ref: 55ab16873242
Ref: c-api/allocation allocating-objects-on-the-heap16873242
Ref: 55ac16873242
Ref: c-api/allocation c _PyObject_New16873319
Ref: 55ad16873319
Ref: c-api/allocation c _PyObject_NewVar16873438
Ref: 55ae16873438
Ref: c-api/allocation c PyObject_Init16873591
Ref: c6216873591
Ref: c-api/allocation c PyObject_InitVar16874604
Ref: 1d2816874604
Ref: c-api/allocation c PyObject_New16875083
Ref: b7e16875083
Ref: c-api/allocation c PyObject_NewVar16876944
Ref: b7f16876944
Ref: c-api/allocation c _Py_NoneStruct16878902
Ref: 55af16878902
Node: Deprecated aliases<3>16879289
Ref: c-api/allocation deprecated-aliases16879377
Ref: 55b016879377
Ref: c-api/allocation c PyObject_NEW16879891
Ref: 55b116879891
Ref: c-api/allocation c PyObject_NEW_VAR16880090
Ref: 55b216880090
Ref: c-api/allocation c PyObject_INIT16880277
Ref: 1d2616880277
Ref: c-api/allocation c PyObject_INIT_VAR16880479
Ref: 1d2716880479
Ref: c-api/allocation c PyObject_MALLOC16880663
Ref: 55b316880663
Ref: c-api/allocation c PyObject_REALLOC16880864
Ref: 55b416880864
Ref: c-api/allocation c PyObject_FREE16881057
Ref: 55b516881057
Ref: c-api/allocation c PyObject_DEL16881251
Ref: 55b616881251
Ref: c-api/allocation c PyObject_Del16881446
Ref: 16d816881446
Node: Object Life Cycle16881557
Ref: c-api/lifecycle doc16881712
Ref: 55b716881712
Ref: c-api/lifecycle life-cycle16881712
Ref: 55b816881712
Ref: c-api/lifecycle object-life-cycle16881712
Ref: 55b916881712
Ref: c-api/lifecycle translation-repo16881712
Ref: 55ba16881712
Node: Life Events16882144
Ref: c-api/lifecycle life-events16882244
Ref: 55bb16882244
Node: Cyclic Isolate Destruction16887550
Ref: c-api/lifecycle cyclic-isolate-destruction16887672
Ref: 55be16887672
Ref: Cyclic Isolate Destruction-Footnote-116892951
Node: Functions<14>16892993
Ref: c-api/lifecycle functions16893095
Ref: 55bf16893095
Ref: c-api/lifecycle c PyObject_CallFinalizer16893212
Ref: 55c016893212
Ref: c-api/lifecycle c PyObject_CallFinalizerFromDealloc16893764
Ref: 55bc16893764
Node: Common Object Structures16894360
Ref: c-api/structures doc16894507
Ref: 55c116894507
Ref: c-api/structures common-object-structures16894507
Ref: 55c216894507
Ref: c-api/structures common-structs16894507
Ref: 55c316894507
Ref: c-api/structures translation-repo16894507
Ref: 55c416894507
Node: Base object types and macros16894863
Ref: c-api/structures base-object-types-and-macros16894995
Ref: 55c516894995
Ref: c-api/structures c PyObject16895503
Ref: 5df16895503
Ref: c-api/structures c PyObject ob_refcnt16896204
Ref: aa116896204
Ref: c-api/structures c PyObject ob_type16896681
Ref: 4eb616896681
Ref: c-api/structures c PyVarObject16896920
Ref: 46be16896920
Ref: c-api/structures c PyVarObject ob_size16897381
Ref: 50f416897381
Ref: c-api/structures c PyObject_HEAD16898127
Ref: 14e516898127
Ref: c-api/structures c PyObject_VAR_HEAD16898388
Ref: 55c616898388
Ref: c-api/structures c PyBaseObject_Type16898691
Ref: 4f4d16898691
Ref: c-api/structures c Py_Is16898879
Ref: aa216898879
Ref: c-api/structures c Py_IsNone16899109
Ref: aa316899109
Ref: c-api/structures c Py_IsTrue16899343
Ref: aa416899343
Ref: c-api/structures c Py_IsFalse16899577
Ref: aa516899577
Ref: c-api/structures c Py_TYPE16899814
Ref: 3c916899814
Ref: c-api/structures c Py_IS_TYPE16900343
Ref: 1b8816900343
Ref: c-api/structures c Py_SET_TYPE16900564
Ref: 98516900564
Ref: c-api/structures c Py_SIZE16901215
Ref: 98616901215
Ref: c-api/structures c Py_SET_SIZE16901504
Ref: 98716901504
Ref: c-api/structures c PyObject_HEAD_INIT16901659
Ref: 55c716901659
Ref: c-api/structures c PyVarObject_HEAD_INIT16901877
Ref: 55c816901877
Node: Implementing functions and methods16902161
Ref: c-api/structures implementing-functions-and-methods16902341
Ref: 55c916902341
Ref: c-api/structures c PyCFunction16902430
Ref: 167f16902430
Ref: c-api/structures c PyCFunctionWithKeywords16903047
Ref: 4f6316903047
Ref: c-api/structures c PyCFunctionFast16903473
Ref: 4f6116903473
Ref: c-api/structures c PyCFunctionFastWithKeywords16903880
Ref: 4f6216903880
Ref: c-api/structures c PyCMethod16904423
Ref: 96916904423
Ref: c-api/structures c PyMethodDef16904913
Ref: 16de16904913
Ref: c-api/structures c PyMethodDef ml_name16905112
Ref: 4ed216905112
Ref: c-api/structures c PyMethodDef ml_meth16905183
Ref: 55cc16905183
Ref: c-api/structures c PyMethodDef ml_flags16905280
Ref: 55cd16905280
Ref: c-api/structures c PyMethodDef ml_doc16905382
Ref: 55ce16905382
Ref: c-api/structures c METH_VARARGS16906113
Ref: 170f16906113
Ref: c-api/structures c METH_KEYWORDS16906669
Ref: 4e8b16906669
Ref: c-api/structures meth-varargs-meth-keywords16906922
Ref: 55ca16906922
Ref: c-api/structures c METH_FASTCALL16907359
Ref: 198616907359
Ref: c-api/structures meth-fastcall-meth-keywords16907926
Ref: 55cb16907926
Ref: c-api/structures c METH_METHOD16908594
Ref: b6a16908594
Ref: c-api/structures meth-method-meth-fastcall-meth-keywords16908803
Ref: 19f116908803
Ref: c-api/structures c METH_NOARGS16909328
Ref: 16db16909328
Ref: c-api/structures c METH_O16909927
Ref: 170e16909927
Ref: c-api/structures c METH_CLASS16910562
Ref: 16dc16910562
Ref: c-api/structures c METH_STATIC16910880
Ref: 16dd16910880
Ref: c-api/structures c METH_COEXIST16911310
Ref: 167e16911310
Ref: c-api/structures c PyCMethod_Type16912018
Ref: 55cf16912018
Ref: c-api/structures c PyCMethod_Check16912230
Ref: 55d016912230
Ref: c-api/structures c PyCMethod_CheckExact16912420
Ref: 55d116912420
Ref: c-api/structures c PyCMethod_New16912574
Ref: 1c9316912574
Ref: c-api/structures c PyCFunction_Type16913734
Ref: 4f6716913734
Ref: c-api/structures c PyCFunction_Check16913989
Ref: 55d216913989
Ref: c-api/structures c PyCFunction_CheckExact16914183
Ref: 55d316914183
Ref: c-api/structures c PyCFunction_NewEx16914341
Ref: 1d5e16914341
Ref: c-api/structures c PyCFunction_New16914612
Ref: 1c9916914612
Ref: c-api/structures c PyCFunction_GetFlags16914881
Ref: 4f6416914881
Ref: c-api/structures c PyCFunction_GET_FLAGS16915295
Ref: 55d416915295
Ref: c-api/structures c PyCFunction_GetFunction16915458
Ref: 4f6516915458
Ref: c-api/structures c PyCFunction_GET_FUNCTION16915900
Ref: 55d516915900
Ref: c-api/structures c PyCFunction_GetSelf16916069
Ref: 4f6616916069
Ref: c-api/structures c PyCFunction_GET_SELF16916744
Ref: 55d616916744
Node: Accessing attributes of extension types16916933
Ref: c-api/structures accessing-attributes-of-extension-types16917076
Ref: 55d716917076
Ref: c-api/structures c PyMemberDef16917175
Ref: 77216917175
Ref: c-api/structures c PyMemberDef name16917518
Ref: 55d816917518
Ref: c-api/structures c PyMemberDef type16917719
Ref: 4ed316917719
Ref: c-api/structures c PyMemberDef offset16917865
Ref: 55d916917865
Ref: c-api/structures c PyMemberDef flags16918014
Ref: 4ed416918014
Ref: c-api/structures c PyMemberDef doc16918138
Ref: 55db16918138
Ref: c-api/structures pymemberdef-offsets16918678
Ref: 52c616918678
Ref: c-api/structures c PyMember_GetOne16920051
Ref: 7ab16920051
Ref: c-api/structures c PyMember_SetOne16920506
Ref: 7ac16920506
Node: Member flags16921087
Ref: c-api/structures member-flags16921196
Ref: 55dc16921196
Ref: c-api/structures pymemberdef-flags16921196
Ref: 55da16921196
Ref: c-api/structures c Py_READONLY16921311
Ref: 7af16921311
Ref: c-api/structures c Py_AUDIT_READ16921420
Ref: 7b016921420
Ref: c-api/structures c Py_RELATIVE_OFFSET16921591
Ref: 77116921591
Node: Member types16922869
Ref: c-api/structures member-types16923015
Ref: 55dd16923015
Ref: c-api/structures pymemberdef-types16923015
Ref: 19d816923015
Ref: c-api/structures c Py_T_BYTE16923897
Ref: 511316923897
Ref: c-api/structures c Py_T_SHORT16924114
Ref: 511916924114
Ref: c-api/structures c Py_T_INT16924328
Ref: 7ad16924328
Ref: c-api/structures c Py_T_LONG16924545
Ref: 511616924545
Ref: c-api/structures c Py_T_LONGLONG16924765
Ref: 511716924765
Ref: c-api/structures c Py_T_UBYTE16924978
Ref: 511c16924978
Ref: c-api/structures c Py_T_UINT16925193
Ref: 511d16925193
Ref: c-api/structures c Py_T_USHORT16925411
Ref: 512016925411
Ref: c-api/structures c Py_T_ULONG16925626
Ref: 511e16925626
Ref: c-api/structures c Py_T_ULONGLONG16925846
Ref: 511f16925846
Ref: c-api/structures c Py_T_PYSSIZET16926061
Ref: 511816926061
Ref: c-api/structures c Py_T_FLOAT16926274
Ref: 511516926274
Ref: c-api/structures c Py_T_DOUBLE16926493
Ref: 7ae16926493
Ref: c-api/structures c Py_T_BOOL16926709
Ref: 511216926709
Ref: c-api/structures c Py_T_STRING16926928
Ref: 511a16926928
Ref: c-api/structures c Py_T_STRING_INPLACE16927157
Ref: 511b16927157
Ref: c-api/structures c Py_T_CHAR16927368
Ref: 511416927368
Ref: c-api/structures c Py_T_OBJECT_EX16927594
Ref: 7b216927594
Ref: c-api/structures c T_OBJECT16928517
Ref: 7b116928517
Ref: c-api/structures c T_NONE16928732
Ref: 7b316928732
Node: Defining Getters and Setters16928821
Ref: c-api/structures defining-getters-and-setters16928946
Ref: 55de16928946
Ref: c-api/structures c PyGetSetDef16929023
Ref: db416929023
Ref: c-api/structures c PyGetSetDef name16929255
Ref: 55df16929255
Ref: c-api/structures c PyGetSetDef get16929318
Ref: 55e016929318
Ref: c-api/structures c PyGetSetDef set16929406
Ref: 55e116929406
Ref: c-api/structures c PyGetSetDef doc16929567
Ref: 55e216929567
Ref: c-api/structures c PyGetSetDef closure16929633
Ref: 55e316929633
Ref: c-api/structures c getter16929765
Ref: 518016929765
Ref: c-api/structures c setter16930149
Ref: 518e16930149
Node: Type Object Structures16930628
Ref: c-api/typeobj doc16930794
Ref: 55e416930794
Ref: c-api/typeobj translation-repo16930794
Ref: 55e516930794
Ref: c-api/typeobj type-object-structures16930794
Ref: 55e616930794
Ref: c-api/typeobj type-structs16930794
Ref: b8616930794
Node: Quick Reference16932252
Ref: c-api/typeobj quick-reference16932358
Ref: 55e816932358
Node: «tp slots»16932468
Ref: c-api/typeobj tp-slots16932550
Ref: 55e916932550
Ref: c-api/typeobj tp-slots-table16932550
Ref: 55ea16932550
Ref: «tp slots»-Footnote-116945801
Ref: «tp slots»-Footnote-216946113
Node: sub-slots16946900
Ref: c-api/typeobj id316947004
Ref: 55f516947004
Ref: c-api/typeobj sub-slots16947004
Ref: 55ec16947004
Node: slot typedefs16957412
Ref: c-api/typeobj slot-typedefs16957495
Ref: 562516957495
Ref: c-api/typeobj slot-typedefs-table16957495
Ref: 55eb16957495
Node: PyTypeObject Definition16965358
Ref: c-api/typeobj pytypeobject-definition16965487
Ref: 562716965487
Node: PyObject Slots16969106
Ref: c-api/typeobj pyobject-slots16969237
Ref: 562816969237
Node: PyVarObject Slots16971264
Ref: c-api/typeobj pyvarobject-slots16971390
Ref: 562916971390
Node: PyTypeObject Slots16971824
Ref: c-api/typeobj pytypeobject-slots16971948
Ref: 562a16971948
Ref: c-api/typeobj c PyTypeObject tp_name16972304
Ref: 1c9816972304
Ref: c-api/typeobj c PyTypeObject tp_basicsize16974063
Ref: b8016974063
Ref: c-api/typeobj c PyTypeObject tp_itemsize16974147
Ref: 23a116974147
Ref: c-api/typeobj c PyTypeObject tp_dealloc16978294
Ref: 4ea516978294
Ref: c-api/typeobj c Py_tp_dealloc16978478
Ref: 515e16978478
Ref: c-api/typeobj c PyTypeObject tp_vectorcall_offset16983791
Ref: 526e16983791
Ref: c-api/typeobj c PyTypeObject tp_getattr16985728
Ref: 4ed616985728
Ref: c-api/typeobj c Py_tp_getattr16985923
Ref: 516516985923
Ref: c-api/typeobj c PyTypeObject tp_setattr16986608
Ref: 4ed716986608
Ref: c-api/typeobj c Py_tp_setattr16986803
Ref: 517216986803
Ref: c-api/typeobj c PyTypeObject tp_as_async16987508
Ref: 10d116987508
Ref: c-api/typeobj c PyTypeObject tp_repr16988086
Ref: 4ecd16988086
Ref: c-api/typeobj c Py_tp_repr16988262
Ref: 517016988262
Ref: c-api/typeobj c PyTypeObject tp_as_number16989169
Ref: b8416989169
Ref: c-api/typeobj c PyTypeObject tp_as_sequence16989603
Ref: 55ed16989603
Ref: c-api/typeobj c PyTypeObject tp_as_mapping16990048
Ref: 55ee16990048
Ref: c-api/typeobj c PyTypeObject tp_hash16990488
Ref: 4edf16990488
Ref: c-api/typeobj c Py_tp_hash16990664
Ref: 516816990664
Ref: c-api/typeobj c PyTypeObject tp_call16992331
Ref: 77c16992331
Ref: c-api/typeobj c Py_tp_call16992510
Ref: 515c16992510
Ref: c-api/typeobj c PyTypeObject tp_str16992863
Ref: 4ece16992863
Ref: c-api/typeobj c Py_tp_str16993037
Ref: 517416993037
Ref: c-api/typeobj c PyTypeObject tp_getattro16993945
Ref: 1a4c16993945
Ref: c-api/typeobj c Py_tp_getattro16994143
Ref: 516616994143
Ref: c-api/typeobj c PyTypeObject tp_setattro16994979
Ref: 4ed116994979
Ref: c-api/typeobj c Py_tp_setattro16995177
Ref: 517316995177
Ref: c-api/typeobj c PyTypeObject tp_as_buffer16996139
Ref: b8216996139
Ref: c-api/typeobj c PyTypeObject tp_flags16996572
Ref: 1c5916996572
Ref: c-api/typeobj c Py_TPFLAGS_HEAPTYPE16998476
Ref: aae16998476
Ref: c-api/typeobj c Py_TPFLAGS_BASETYPE16999290
Ref: 4ebe16999290
Ref: c-api/typeobj c Py_TPFLAGS_READY16999615
Ref: 563016999615
Ref: c-api/typeobj c Py_TPFLAGS_READYING16999807
Ref: 563116999807
Ref: c-api/typeobj c Py_TPFLAGS_HAVE_GC17000008
Ref: 98217000008
Ref: c-api/typeobj c Py_TPFLAGS_DEFAULT17001063
Ref: 4eb317001063
Ref: c-api/typeobj c Py_TPFLAGS_METHOD_DESCRIPTOR17001448
Ref: 511017001448
Ref: c-api/typeobj c Py_TPFLAGS_MANAGED_DICT17002446
Ref: 60f17002446
Ref: c-api/typeobj c Py_TPFLAGS_MANAGED_WEAKREF17003112
Ref: 77d17003112
Ref: c-api/typeobj c Py_TPFLAGS_ITEMS_AT_END17003433
Ref: 76e17003433
Ref: c-api/typeobj c Py_TPFLAGS_LONG_SUBCLASS17004169
Ref: 52b817004169
Ref: c-api/typeobj c Py_TPFLAGS_LIST_SUBCLASS17004213
Ref: 563217004213
Ref: c-api/typeobj c Py_TPFLAGS_TUPLE_SUBCLASS17004257
Ref: 563317004257
Ref: c-api/typeobj c Py_TPFLAGS_BYTES_SUBCLASS17004302
Ref: 563417004302
Ref: c-api/typeobj c Py_TPFLAGS_UNICODE_SUBCLASS17004347
Ref: 563517004347
Ref: c-api/typeobj c Py_TPFLAGS_DICT_SUBCLASS17004394
Ref: 563617004394
Ref: c-api/typeobj c Py_TPFLAGS_BASE_EXC_SUBCLASS17004438
Ref: 563717004438
Ref: c-api/typeobj c Py_TPFLAGS_TYPE_SUBCLASS17004486
Ref: 563817004486
Ref: c-api/typeobj c Py_TPFLAGS_HAVE_FINALIZE17005094
Ref: 42717005094
Ref: c-api/typeobj c _Py_TPFLAGS_HAVE_VECTORCALL17005479
Ref: 563917005479
Ref: c-api/typeobj c Py_TPFLAGS_HAVE_VECTORCALL17005479
Ref: 77717005479
Ref: c-api/typeobj c Py_TPFLAGS_IMMUTABLETYPE17006337
Ref: 3cf17006337
Ref: c-api/typeobj c Py_TPFLAGS_DISALLOW_INSTANTIATION17006705
Ref: 7a317006705
Ref: c-api/typeobj c Py_TPFLAGS_MAPPING17007834
Ref: 1c4017007834
Ref: c-api/typeobj c Py_TPFLAGS_SEQUENCE17008689
Ref: 1c4117008689
Ref: c-api/typeobj c Py_TPFLAGS_VALID_VERSION_TAG17009545
Ref: 563a17009545
Ref: c-api/typeobj c PyTypeObject tp_doc17009899
Ref: 4eb417009899
Ref: c-api/typeobj c Py_tp_doc17010063
Ref: 516217010063
Ref: c-api/typeobj c PyTypeObject tp_traverse17010337
Ref: 98317010337
Ref: c-api/typeobj c Py_tp_traverse17010535
Ref: 517517010535
Ref: c-api/typeobj c PyTypeObject tp_clear17014976
Ref: 4ecb17014976
Ref: c-api/typeobj c Py_tp_clear17015153
Ref: 515d17015153
Ref: c-api/typeobj c PyTypeObject tp_richcompare17022486
Ref: 4ed917022486
Ref: c-api/typeobj c Py_tp_richcompare17022689
Ref: 517117022689
Ref: c-api/typeobj c Py_LT17023585
Ref: 526117023585
Ref: c-api/typeobj c Py_LE17023685
Ref: 526217023685
Ref: c-api/typeobj c Py_EQ17023786
Ref: 526317023786
Ref: c-api/typeobj c Py_NE17023887
Ref: 526417023887
Ref: c-api/typeobj c Py_GT17023988
Ref: 526517023988
Ref: c-api/typeobj c Py_GE17024088
Ref: 526617024088
Ref: c-api/typeobj c Py_RETURN_RICHCOMPARE17024221
Ref: daf17024221
Ref: c-api/typeobj c PyTypeObject tp_weaklistoffset17025492
Ref: b8117025492
Ref: c-api/typeobj c PyTypeObject tp_iter17027022
Ref: 16f617027022
Ref: c-api/typeobj c Py_tp_iter17027201
Ref: 516b17027201
Ref: c-api/typeobj c PyTypeObject tp_iternext17027654
Ref: 16f717027654
Ref: c-api/typeobj c Py_tp_iternext17027852
Ref: 516c17027852
Ref: c-api/typeobj c PyTypeObject tp_methods17028604
Ref: 4ebd17028604
Ref: c-api/typeobj c Py_tp_methods17028807
Ref: 516e17028807
Ref: c-api/typeobj c PyTypeObject tp_members17029247
Ref: 4ebb17029247
Ref: c-api/typeobj c Py_tp_members17029449
Ref: 516d17029449
Ref: c-api/typeobj c PyTypeObject tp_getset17029924
Ref: 4ec017029924
Ref: c-api/typeobj c Py_tp_getset17030124
Ref: 516717030124
Ref: c-api/typeobj c PyTypeObject tp_base17030592
Ref: 235c17030592
Ref: c-api/typeobj c Py_tp_base17030772
Ref: 515a17030772
Ref: c-api/typeobj c PyTypeObject tp_dict17032021
Ref: 1a7417032021
Ref: c-api/typeobj c PyTypeObject tp_descr_get17033550
Ref: 55ef17033550
Ref: c-api/typeobj c Py_tp_descr_get17033750
Ref: 516017033750
Ref: c-api/typeobj c PyTypeObject tp_descr_set17033992
Ref: 1c9c17033992
Ref: c-api/typeobj c Py_tp_descr_set17034192
Ref: 516117034192
Ref: c-api/typeobj c PyTypeObject tp_dictoffset17034531
Ref: 52c517034531
Ref: c-api/typeobj c PyTypeObject tp_init17036423
Ref: 7a217036423
Ref: c-api/typeobj c Py_tp_init17036599
Ref: 516917036599
Ref: c-api/typeobj c PyTypeObject tp_alloc17037997
Ref: 4eb917037997
Ref: c-api/typeobj c Py_tp_alloc17038176
Ref: 515917038176
Ref: c-api/typeobj c PyTypeObject tp_new17038725
Ref: 7a017038725
Ref: c-api/typeobj c Py_tp_new17038898
Ref: 516f17038898
Ref: c-api/typeobj c PyTypeObject tp_free17040568
Ref: 4eb817040568
Ref: c-api/typeobj c Py_tp_free17040744
Ref: 516417040744
Ref: c-api/typeobj c PyTypeObject tp_is_gc17041715
Ref: 55f017041715
Ref: c-api/typeobj c Py_tp_is_gc17041892
Ref: 516a17041892
Ref: c-api/typeobj c PyTypeObject tp_bases17043008
Ref: 55f117043008
Ref: c-api/typeobj c Py_tp_bases17043186
Ref: 515b17043186
Ref: c-api/typeobj c PyTypeObject tp_mro17043881
Ref: 52c717043881
Ref: c-api/typeobj c PyTypeObject tp_cache17044361
Ref: 52c817044361
Ref: c-api/typeobj c PyTypeObject tp_subclasses17044521
Ref: 79317044521
Ref: c-api/typeobj c PyTypeObject tp_weaklist17044982
Ref: 52c917044982
Ref: c-api/typeobj c PyTypeObject tp_del17045561
Ref: 55f217045561
Ref: c-api/typeobj c Py_tp_del17045737
Ref: 515f17045737
Ref: c-api/typeobj c PyTypeObject tp_version_tag17045809
Ref: 55f317045809
Ref: c-api/typeobj c PyTypeObject tp_finalize17045995
Ref: c9f17045995
Ref: c-api/typeobj c Py_tp_finalize17046211
Ref: 516317046211
Ref: c-api/typeobj c PyTypeObject tp_vectorcall17053615
Ref: 197217053615
Ref: c-api/typeobj c Py_tp_vectorcall17053839
Ref: 517617053839
Ref: c-api/typeobj c PyTypeObject tp_watched17055399
Ref: 55f417055399
Ref: PyTypeObject Slots-Footnote-117055557
Ref: PyTypeObject Slots-Footnote-217055599
Ref: PyTypeObject Slots-Footnote-317055641
Ref: PyTypeObject Slots-Footnote-417055684
Node: Static Types17055726
Ref: c-api/typeobj id417055843
Ref: 563b17055843
Ref: c-api/typeobj static-types17055843
Ref: 98417055843
Node: Heap Types17056750
Ref: c-api/typeobj heap-types17056873
Ref: b6017056873
Ref: c-api/typeobj id517056873
Ref: 563c17056873
Node: Number Object Structures17057378
Ref: c-api/typeobj number-object-structures17057514
Ref: 563d17057514
Ref: c-api/typeobj number-structs17057514
Ref: 562c17057514
Ref: c-api/typeobj c PyNumberMethods17057585
Ref: 162517057585
Ref: c-api/typeobj c PyNumberMethods nb_add17060033
Ref: 52bb17060033
Ref: c-api/typeobj c Py_nb_add17060213
Ref: 512f17060213
Ref: c-api/typeobj c PyNumberMethods nb_subtract17060215
Ref: 55fc17060215
Ref: c-api/typeobj c Py_nb_subtract17060415
Ref: 514e17060415
Ref: c-api/typeobj c PyNumberMethods nb_multiply17060417
Ref: 55fe17060417
Ref: c-api/typeobj c Py_nb_multiply17060617
Ref: 514717060617
Ref: c-api/typeobj c PyNumberMethods nb_remainder17060619
Ref: 560017060619
Ref: c-api/typeobj c Py_nb_remainder17060821
Ref: 514c17060821
Ref: c-api/typeobj c PyNumberMethods nb_divmod17060823
Ref: 560217060823
Ref: c-api/typeobj c Py_nb_divmod17061019
Ref: 513217061019
Ref: c-api/typeobj c PyNumberMethods nb_power17061021
Ref: 560317061021
Ref: c-api/typeobj c Py_nb_power17061216
Ref: 514b17061216
Ref: c-api/typeobj c PyNumberMethods nb_negative17061218
Ref: 560517061218
Ref: c-api/typeobj c Py_nb_negative17061417
Ref: 514817061417
Ref: c-api/typeobj c PyNumberMethods nb_positive17061419
Ref: 560617061419
Ref: c-api/typeobj c Py_nb_positive17061618
Ref: 514a17061618
Ref: c-api/typeobj c PyNumberMethods nb_absolute17061620
Ref: 560717061620
Ref: c-api/typeobj c Py_nb_absolute17061819
Ref: 512e17061819
Ref: c-api/typeobj c PyNumberMethods nb_bool17061821
Ref: 560817061821
Ref: c-api/typeobj c Py_nb_bool17062000
Ref: 513117062000
Ref: c-api/typeobj c PyNumberMethods nb_invert17062002
Ref: 560917062002
Ref: c-api/typeobj c Py_nb_invert17062197
Ref: 514417062197
Ref: c-api/typeobj c PyNumberMethods nb_lshift17062199
Ref: 560a17062199
Ref: c-api/typeobj c Py_nb_lshift17062395
Ref: 514517062395
Ref: c-api/typeobj c PyNumberMethods nb_rshift17062397
Ref: 560c17062397
Ref: c-api/typeobj c Py_nb_rshift17062593
Ref: 514d17062593
Ref: c-api/typeobj c PyNumberMethods nb_and17062595
Ref: 560e17062595
Ref: c-api/typeobj c Py_nb_and17062775
Ref: 513017062775
Ref: c-api/typeobj c PyNumberMethods nb_xor17062777
Ref: 561017062777
Ref: c-api/typeobj c Py_nb_xor17062957
Ref: 515017062957
Ref: c-api/typeobj c PyNumberMethods nb_or17062959
Ref: 561217062959
Ref: c-api/typeobj c Py_nb_or17063137
Ref: 514917063137
Ref: c-api/typeobj c PyNumberMethods nb_int17063139
Ref: 561417063139
Ref: c-api/typeobj c Py_nb_int17063318
Ref: 514317063318
Ref: c-api/typeobj c PyNumberMethods nb_reserved17063320
Ref: 561517063320
Ref: c-api/typeobj c PyNumberMethods nb_float17063381
Ref: 561617063381
Ref: c-api/typeobj c Py_nb_float17063574
Ref: 513317063574
Ref: c-api/typeobj c PyNumberMethods nb_inplace_add17063576
Ref: 55fb17063576
Ref: c-api/typeobj c Py_nb_inplace_add17063782
Ref: 513617063782
Ref: c-api/typeobj c PyNumberMethods nb_inplace_subtract17063784
Ref: 55fd17063784
Ref: c-api/typeobj c Py_nb_inplace_subtract17064000
Ref: 514017064000
Ref: c-api/typeobj c PyNumberMethods nb_inplace_multiply17064002
Ref: 55ff17064002
Ref: c-api/typeobj c Py_nb_inplace_multiply17064218
Ref: 513b17064218
Ref: c-api/typeobj c PyNumberMethods nb_inplace_remainder17064220
Ref: 560117064220
Ref: c-api/typeobj c Py_nb_inplace_remainder17064438
Ref: 513e17064438
Ref: c-api/typeobj c PyNumberMethods nb_inplace_power17064440
Ref: 560417064440
Ref: c-api/typeobj c Py_nb_inplace_power17064651
Ref: 513d17064651
Ref: c-api/typeobj c PyNumberMethods nb_inplace_lshift17064653
Ref: 560b17064653
Ref: c-api/typeobj c Py_nb_inplace_lshift17064865
Ref: 513917064865
Ref: c-api/typeobj c PyNumberMethods nb_inplace_rshift17064867
Ref: 560d17064867
Ref: c-api/typeobj c Py_nb_inplace_rshift17065079
Ref: 513f17065079
Ref: c-api/typeobj c PyNumberMethods nb_inplace_and17065081
Ref: 560f17065081
Ref: c-api/typeobj c Py_nb_inplace_and17065287
Ref: 513717065287
Ref: c-api/typeobj c PyNumberMethods nb_inplace_xor17065289
Ref: 561117065289
Ref: c-api/typeobj c Py_nb_inplace_xor17065495
Ref: 514217065495
Ref: c-api/typeobj c PyNumberMethods nb_inplace_or17065497
Ref: 561317065497
Ref: c-api/typeobj c Py_nb_inplace_or17065701
Ref: 513c17065701
Ref: c-api/typeobj c PyNumberMethods nb_floor_divide17065703
Ref: 561717065703
Ref: c-api/typeobj c Py_nb_floor_divide17065911
Ref: 513417065911
Ref: c-api/typeobj c PyNumberMethods nb_true_divide17065913
Ref: 561917065913
Ref: c-api/typeobj c Py_nb_true_divide17066119
Ref: 514f17066119
Ref: c-api/typeobj c PyNumberMethods nb_inplace_floor_divide17066121
Ref: 561817066121
Ref: c-api/typeobj c Py_nb_inplace_floor_divide17066350
Ref: 513817066350
Ref: c-api/typeobj c PyNumberMethods nb_inplace_true_divide17066352
Ref: 561a17066352
Ref: c-api/typeobj c Py_nb_inplace_true_divide17066575
Ref: 514117066575
Ref: c-api/typeobj c PyNumberMethods nb_index17066576
Ref: 162417066576
Ref: c-api/typeobj c Py_nb_index17066769
Ref: 513517066769
Ref: c-api/typeobj c PyNumberMethods nb_matrix_multiply17066771
Ref: 561b17066771
Ref: c-api/typeobj c Py_nb_matrix_multiply17067005
Ref: 514617067005
Ref: c-api/typeobj c PyNumberMethods nb_inplace_matrix_multiply17067007
Ref: 561c17067007
Ref: c-api/typeobj c Py_nb_inplace_matrix_multiply17067262
Ref: 513a17067262
Node: Mapping Object Structures17067264
Ref: c-api/typeobj mapping-object-structures17067416
Ref: 563e17067416
Ref: c-api/typeobj mapping-structs17067416
Ref: 562e17067416
Ref: c-api/typeobj c PyMappingMethods17067489
Ref: 4ede17067489
Ref: c-api/typeobj c PyMappingMethods mp_length17067661
Ref: 561d17067661
Ref: c-api/typeobj c Py_mp_length17067855
Ref: 512c17067855
Ref: c-api/typeobj c PyMappingMethods mp_subscript17068062
Ref: 1cde17068062
Ref: c-api/typeobj c Py_mp_subscript17068265
Ref: 512d17068265
Ref: c-api/typeobj c PyMappingMethods mp_ass_subscript17068569
Ref: 561e17068569
Ref: c-api/typeobj c Py_mp_ass_subscript17068783
Ref: 512b17068783
Node: Sequence Object Structures17069179
Ref: c-api/typeobj sequence-object-structures17069331
Ref: 563f17069331
Ref: c-api/typeobj sequence-structs17069331
Ref: 562d17069331
Ref: c-api/typeobj c PySequenceMethods17069406
Ref: 4edd17069406
Ref: c-api/typeobj c PySequenceMethods sq_length17069557
Ref: 52c417069557
Ref: c-api/typeobj c Py_sq_length17069752
Ref: 515717069752
Ref: c-api/typeobj c PySequenceMethods sq_concat17070008
Ref: 561f17070008
Ref: c-api/typeobj c Py_sq_concat17070206
Ref: 515217070206
Ref: c-api/typeobj c PySequenceMethods sq_repeat17070420
Ref: 562017070420
Ref: c-api/typeobj c Py_sq_repeat17070620
Ref: 515817070620
Ref: c-api/typeobj c PySequenceMethods sq_item17070846
Ref: 1cdd17070846
Ref: c-api/typeobj c Py_sq_item17071042
Ref: 515617071042
Ref: c-api/typeobj c PySequenceMethods sq_ass_item17071712
Ref: 562117071712
Ref: c-api/typeobj c Py_sq_ass_item17071919
Ref: 515117071919
Ref: c-api/typeobj c PySequenceMethods sq_contains17072314
Ref: 562217072314
Ref: c-api/typeobj c Py_sq_contains17072516
Ref: 515317072516
Ref: c-api/typeobj c PySequenceMethods sq_inplace_concat17072763
Ref: 562317072763
Ref: c-api/typeobj c Py_sq_inplace_concat17072977
Ref: 515417072977
Ref: c-api/typeobj c PySequenceMethods sq_inplace_repeat17073431
Ref: 562417073431
Ref: c-api/typeobj c Py_sq_inplace_repeat17073647
Ref: 515517073647
Node: Buffer Object Structures17074112
Ref: c-api/typeobj buffer-object-structures17074262
Ref: 564017074262
Ref: c-api/typeobj buffer-structs17074262
Ref: 529017074262
Ref: c-api/typeobj c PyBufferProcs17074333
Ref: 52ca17074333
Ref: c-api/typeobj c PyBufferProcs bf_getbuffer17074567
Ref: 96717074567
Ref: c-api/typeobj c Py_bf_getbuffer17074791
Ref: 512717074791
Ref: c-api/typeobj c PyBufferProcs bf_releasebuffer17076588
Ref: 96817076588
Ref: c-api/typeobj c Py_bf_releasebuffer17076824
Ref: 512817076824
Node: Async Object Structures17077867
Ref: c-api/typeobj async-object-structures17078009
Ref: 564117078009
Ref: c-api/typeobj async-structs17078009
Ref: 562b17078009
Ref: c-api/typeobj c PyAsyncMethods17078101
Ref: 52c317078101
Ref: c-api/typeobj c PyAsyncMethods am_await17078518
Ref: 55f617078518
Ref: c-api/typeobj c Py_am_await17078720
Ref: 512517078720
Ref: c-api/typeobj c PyAsyncMethods am_aiter17079026
Ref: 55f717079026
Ref: c-api/typeobj c Py_am_aiter17079228
Ref: 512317079228
Ref: c-api/typeobj c PyAsyncMethods am_anext17079540
Ref: 55f817079540
Ref: c-api/typeobj c Py_am_anext17079742
Ref: 512417079742
Ref: c-api/typeobj c PyAsyncMethods am_send17079968
Ref: 55f917079968
Ref: c-api/typeobj c Py_am_send17080168
Ref: 512617080168
Node: Slot Type typedefs17080414
Ref: c-api/typeobj id617080544
Ref: 562617080544
Ref: c-api/typeobj slot-type-typedefs17080544
Ref: 564217080544
Ref: c-api/typeobj c allocfunc17080603
Ref: 517717080603
Ref: c-api/typeobj c destructor17081673
Ref: 517b17081673
Ref: c-api/typeobj c freefunc17081778
Ref: 542217081778
Ref: c-api/typeobj c newfunc17081854
Ref: 518617081854
Ref: c-api/typeobj c initproc17082057
Ref: 518217082057
Ref: c-api/typeobj c reprfunc17082240
Ref: 518a17082240
Ref: c-api/typeobj c getattrfunc17082396
Ref: 517c17082396
Ref: c-api/typeobj c setattrfunc17082608
Ref: 518c17082608
Ref: c-api/typeobj c getattrofunc17082899
Ref: 517d17082899
Ref: c-api/typeobj c setattrofunc17083163
Ref: 518d17083163
Ref: c-api/typeobj c descrgetfunc17083506
Ref: 517917083506
Ref: c-api/typeobj c descrsetfunc17083717
Ref: 517a17083717
Ref: c-api/typeobj c hashfunc17083910
Ref: 518117083910
Ref: c-api/typeobj c richcmpfunc17084067
Ref: 518b17084067
Ref: c-api/typeobj c getiterfunc17084266
Ref: 517f17084266
Ref: c-api/typeobj c iternextfunc17084425
Ref: 518417084425
Ref: c-api/typeobj c lenfunc17084589
Ref: 518517084589
Ref: c-api/typeobj c getbufferproc17084719
Ref: 517e17084719
Ref: c-api/typeobj c releasebufferproc17084886
Ref: 518917084886
Ref: c-api/typeobj c unaryfunc17085053
Ref: 519317085053
Ref: c-api/typeobj c binaryfunc17085184
Ref: 517817085184
Ref: c-api/typeobj c sendfunc17085339
Ref: 55fa17085339
Ref: c-api/typeobj c ternaryfunc17085519
Ref: 519117085519
Ref: c-api/typeobj c ssizeargfunc17085698
Ref: 518f17085698
Ref: c-api/typeobj c ssizeobjargproc17085856
Ref: 519017085856
Ref: c-api/typeobj c objobjproc17086021
Ref: 518817086021
Ref: c-api/typeobj c objobjargproc17086158
Ref: 518717086158
Node: Examples<39>17086321
Ref: c-api/typeobj examples17086419
Ref: 564317086419
Ref: c-api/typeobj typedef-examples17086419
Ref: 55e717086419
Node: Supporting Cyclic Garbage Collection17091794
Ref: c-api/gcsupport doc17091927
Ref: 564417091927
Ref: c-api/gcsupport supporting-cycle-detection17091927
Ref: 562f17091927
Ref: c-api/gcsupport supporting-cyclic-garbage-collection17091927
Ref: 564517091927
Ref: c-api/gcsupport translation-repo17091927
Ref: 564617091927
Ref: c-api/gcsupport c PyObject_GC_New17094288
Ref: c9b17094288
Ref: c-api/gcsupport c PyObject_GC_NewVar17095104
Ref: c9c17095104
Ref: c-api/gcsupport c PyUnstable_Object_GC_NewWithExtraData17095935
Ref: 1a9017095935
Ref: c-api/gcsupport c PyObject_GC_Resize17097130
Ref: 1a9517097130
Ref: c-api/gcsupport c PyObject_GC_Track17097513
Ref: 170b17097513
Ref: c-api/gcsupport c PyObject_IS_GC17097950
Ref: b7d17097950
Ref: c-api/gcsupport c PyObject_GC_IsTracked17098201
Ref: b6f17098201
Ref: c-api/gcsupport c PyObject_GC_IsFinalized17098583
Ref: b7017098583
Ref: c-api/gcsupport c PyObject_GC_Del17098968
Ref: 170a17098968
Ref: c-api/gcsupport c PyObject_GC_UnTrack17099763
Ref: 170c17099763
Ref: c-api/gcsupport c visitproc17100487
Ref: 519417100487
Ref: c-api/gcsupport c traverseproc17101101
Ref: 519217101101
Ref: c-api/gcsupport c Py_VISIT17102098
Ref: 4ec217102098
Ref: c-api/gcsupport c inquiry17102694
Ref: 518317102694
Node: Controlling the Garbage Collector State17103315
Ref: c-api/gcsupport controlling-the-garbage-collector-state17103468
Ref: 564717103468
Ref: c-api/gcsupport c PyGC_Collect17103652
Ref: b8717103652
Ref: c-api/gcsupport c PyGC_Enable17104218
Ref: aa617104218
Ref: c-api/gcsupport c PyGC_Disable17104490
Ref: aa717104490
Ref: c-api/gcsupport c PyGC_IsEnabled17104764
Ref: aa817104764
Node: Querying Garbage Collector State17105058
Ref: c-api/gcsupport querying-garbage-collector-state17105211
Ref: 564817105211
Ref: c-api/gcsupport c PyUnstable_GC_VisitObjects17105394
Ref: 564917105394
Ref: c-api/gcsupport c gcvisitobjects_t17106200
Ref: 564a17106200
Node: API and ABI Versioning17106687
Ref: c-api/apiabiversion doc17106838
Ref: 564b17106838
Ref: c-api/apiabiversion api-and-abi-versioning17106838
Ref: 564c17106838
Ref: c-api/apiabiversion apiabiversion17106838
Ref: 490a17106838
Ref: c-api/apiabiversion translation-repo17106838
Ref: 564d17106838
Node: Build-time version constants17106982
Ref: c-api/apiabiversion build-time-version-constants17107094
Ref: 564e17107094
Ref: c-api/apiabiversion c PY_MAJOR_VERSION17107449
Ref: 564f17107449
Ref: c-api/apiabiversion c PY_MINOR_VERSION17107516
Ref: 565017107516
Ref: c-api/apiabiversion c PY_MICRO_VERSION17107583
Ref: 565117107583
Ref: c-api/apiabiversion c PY_RELEASE_LEVEL17107650
Ref: 565217107650
Ref: c-api/apiabiversion c PY_RELEASE_SERIAL17107832
Ref: 565317107832
Ref: c-api/apiabiversion c PY_VERSION_HEX17107926
Ref: 38217107926
Ref: Build-time version constants-Footnote-117108268
Node: Run-time version17108341
Ref: c-api/apiabiversion run-time-version17108480
Ref: 565417108480
Ref: c-api/apiabiversion c Py_Version17108529
Ref: 38117108529
Node: Bit-packing macros17108962
Ref: c-api/apiabiversion bit-packing-macros17109064
Ref: 565517109064
Ref: c-api/apiabiversion c Py_PACK_FULL_VERSION17109117
Ref: 38017109117
Ref: c-api/apiabiversion c Py_PACK_VERSION17112759
Ref: 37f17112759
Node: Monitoring C API17113089
Ref: c-api/monitoring doc17113238
Ref: 565617113238
Ref: c-api/monitoring c-api-monitoring17113238
Ref: 48617113238
Ref: c-api/monitoring monitoring-c-api17113238
Ref: 565717113238
Ref: c-api/monitoring translation-repo17113238
Ref: 565817113238
Node: Generating Execution Events17113492
Ref: c-api/monitoring generating-execution-events17113610
Ref: 565917113610
Ref: c-api/monitoring c PyMonitoringState17114545
Ref: 5be17114545
Ref: c-api/monitoring c PyMonitoring_FirePyStartEvent17114907
Ref: 5bf17114907
Ref: c-api/monitoring c PyMonitoring_FirePyResumeEvent17115066
Ref: 5c017115066
Ref: c-api/monitoring c PyMonitoring_FirePyReturnEvent17115227
Ref: 5c117115227
Ref: c-api/monitoring c PyMonitoring_FirePyYieldEvent17115406
Ref: 5c217115406
Ref: c-api/monitoring c PyMonitoring_FireCallEvent17115583
Ref: 5c317115583
Ref: c-api/monitoring c PyMonitoring_FireLineEvent17115781
Ref: 5c417115781
Ref: c-api/monitoring c PyMonitoring_FireJumpEvent17115945
Ref: 5c517115945
Ref: c-api/monitoring c PyMonitoring_FireBranchLeftEvent17116132
Ref: 3ad17116132
Ref: c-api/monitoring c PyMonitoring_FireBranchRightEvent17116332
Ref: 3ae17116332
Ref: c-api/monitoring c PyMonitoring_FireCReturnEvent17116534
Ref: 5c617116534
Ref: c-api/monitoring c PyMonitoring_FirePyThrowEvent17116711
Ref: 5c717116711
Ref: c-api/monitoring c PyMonitoring_FireRaiseEvent17116958
Ref: 5c817116958
Ref: c-api/monitoring c PyMonitoring_FireCRaiseEvent17117200
Ref: 5c917117200
Ref: c-api/monitoring c PyMonitoring_FireReraiseEvent17117445
Ref: 5ca17117445
Ref: c-api/monitoring c PyMonitoring_FireExceptionHandledEvent17117691
Ref: 5cb17117691
Ref: c-api/monitoring c PyMonitoring_FirePyUnwindEvent17117957
Ref: 5cc17117957
Ref: c-api/monitoring c PyMonitoring_FireStopIterationEvent17118206
Ref: 5cd17118206
Node: Managing the Monitoring State17118633
Ref: c-api/monitoring managing-the-monitoring-state17118726
Ref: 565a17118726
Ref: c-api/monitoring c PyMonitoring_EnterScope17118929
Ref: 5ce17118929
Ref: c-api/monitoring c PY_MONITORING_EVENT_BRANCH_LEFT17120985
Ref: 565b17120985
Ref: c-api/monitoring c PY_MONITORING_EVENT_BRANCH_RIGHT17121192
Ref: 565c17121192
Ref: c-api/monitoring c PY_MONITORING_EVENT_CALL17121391
Ref: 565d17121391
Ref: c-api/monitoring c PY_MONITORING_EVENT_C_RAISE17121594
Ref: 565e17121594
Ref: c-api/monitoring c PY_MONITORING_EVENT_C_RETURN17121798
Ref: 565f17121798
Ref: c-api/monitoring c PY_MONITORING_EVENT_EXCEPTION_HANDLED17122011
Ref: 566017122011
Ref: c-api/monitoring c PY_MONITORING_EVENT_INSTRUCTION17122218
Ref: 566117122218
Ref: c-api/monitoring c PY_MONITORING_EVENT_JUMP17122418
Ref: 566217122418
Ref: c-api/monitoring c PY_MONITORING_EVENT_LINE17122618
Ref: 566317122618
Ref: c-api/monitoring c PY_MONITORING_EVENT_PY_RESUME17122823
Ref: 566417122823
Ref: c-api/monitoring c PY_MONITORING_EVENT_PY_RETURN17123028
Ref: 566517123028
Ref: c-api/monitoring c PY_MONITORING_EVENT_PY_START17123232
Ref: 566617123232
Ref: c-api/monitoring c PY_MONITORING_EVENT_PY_THROW17123436
Ref: 566717123436
Ref: c-api/monitoring c PY_MONITORING_EVENT_PY_UNWIND17123641
Ref: 566817123641
Ref: c-api/monitoring c PY_MONITORING_EVENT_PY_YIELD17123845
Ref: 566917123845
Ref: c-api/monitoring c PY_MONITORING_EVENT_RAISE17124046
Ref: 566a17124046
Ref: c-api/monitoring c PY_MONITORING_EVENT_RERAISE17124249
Ref: 566b17124249
Ref: c-api/monitoring c PY_MONITORING_EVENT_STOP_ITERATION17124459
Ref: 566c17124459
Ref: c-api/monitoring c PyMonitoring_ExitScope17124557
Ref: 5cf17124557
Ref: c-api/monitoring c PY_MONITORING_IS_INSTRUMENTED_EVENT17124694
Ref: 566d17124694
Node: Installing Python Modules17124981
Ref: installing/index doc17125106
Ref: 566e17125106
Ref: installing/index installing-index17125106
Ref: 10fa17125106
Ref: installing/index installing-python-modules17125106
Ref: 566f17125106
Ref: installing/index translation-repo17125106
Ref: 567017125106
Ref: Installing Python Modules-Footnote-117126283
Node: Key terms17126361
Ref: installing/index key-terms17126455
Ref: 567117126455
Ref: Key terms-Footnote-117128561
Ref: Key terms-Footnote-217128586
Ref: Key terms-Footnote-317128615
Ref: Key terms-Footnote-417128647
Node: Basic usage<2>17128727
Ref: installing/index basic-usage17128843
Ref: 567217128843
Ref: Basic usage<2>-Footnote-117130498
Ref: Basic usage<2>-Footnote-217130535
Node: How do I …?17130584
Ref: installing/index how-do-i17130717
Ref: 567317130717
Node: … install pip in versions of Python prior to Python 3 4?17131106
Ref: installing/index install-pip-in-versions-of-python-prior-to-python-3-417131270
Ref: 567417131270
Ref: … install pip in versions of Python prior to Python 3 4?-Footnote-117131704
Node: … install packages just for the current user?17131791
Ref: installing/index install-packages-just-for-the-current-user17132003
Ref: 567517132003
Node: … install scientific Python packages?17132265
Ref: installing/index install-scientific-python-packages17132483
Ref: 567617132483
Ref: … install scientific Python packages?-Footnote-117132993
Ref: … install scientific Python packages?-Footnote-217133039
Node: … work with multiple versions of Python installed in parallel?17133085
Ref: installing/index work-with-multiple-versions-of-python-installed-in-parallel17133247
Ref: 567717133247
Node: Common installation issues17134219
Ref: installing/index common-installation-issues17134329
Ref: 567817134329
Node: Installing into the system Python on Linux17134504
Ref: installing/index installing-into-the-system-python-on-linux17134635
Ref: 567917134635
Node: Pip not installed17135202
Ref: installing/index pip-not-installed17135370
Ref: 567a17135370
Ref: Pip not installed-Footnote-117135644
Node: Installing binary extensions17135770
Ref: installing/index installing-binary-extensions17135887
Ref: 567b17135887
Ref: Installing binary extensions-Footnote-117136781
Ref: Installing binary extensions-Footnote-217136827
Node: Python HOWTOs17136876
Ref: howto/index doc17137005
Ref: 567c17137005
Ref: howto/index how-tos17137005
Ref: 567d17137005
Ref: howto/index python-howtos17137005
Ref: 567e17137005
Ref: howto/index translation-repo17137005
Ref: 567f17137005
Node: A Conceptual Overview of asyncio17138364
Ref: howto/a-conceptual-overview-of-asyncio doc17138492
Ref: 568017138492
Ref: howto/a-conceptual-overview-of-asyncio a-conceptual-overview-of-asyncio17138492
Ref: 379d17138492
Ref: howto/a-conceptual-overview-of-asyncio id117138492
Ref: 568117138492
Ref: A Conceptual Overview of asyncio-Footnote-117139874
Ref: A Conceptual Overview of asyncio-Footnote-217139955
Ref: A Conceptual Overview of asyncio-Footnote-317140048
Node: A conceptual overview part 1 the high-level17140129
Ref: howto/a-conceptual-overview-of-asyncio a-conceptual-overview-part-1-the-high-level17140297
Ref: 568217140297
Node: Event Loop<2>17140671
Ref: howto/a-conceptual-overview-of-asyncio event-loop17140810
Ref: 568317140810
Node: Asynchronous functions and coroutines17142418
Ref: howto/a-conceptual-overview-of-asyncio asynchronous-functions-and-coroutines17142574
Ref: 568417142574
Node: Tasks<2>17145508
Ref: howto/a-conceptual-overview-of-asyncio tasks17145656
Ref: 568517145656
Node: await17148600
Ref: howto/a-conceptual-overview-of-asyncio await17148702
Ref: 568617148702
Node: A conceptual overview part 2 the nuts and bolts17152884
Ref: howto/a-conceptual-overview-of-asyncio a-conceptual-overview-part-2-the-nuts-and-bolts17153052
Ref: 568717153052
Node: The inner workings of coroutines17153542
Ref: howto/a-conceptual-overview-of-asyncio the-inner-workings-of-coroutines17153677
Ref: 568817153677
Node: Futures<2>17157338
Ref: howto/a-conceptual-overview-of-asyncio futures17157506
Ref: 568917157506
Node: A homemade asyncio sleep17158777
Ref: howto/a-conceptual-overview-of-asyncio a-homemade-asyncio-sleep17158904
Ref: 568a17158904
Node: Porting Extension Modules to Python 317163530
Ref: howto/cporting doc17163697
Ref: 568b17163697
Ref: howto/cporting cporting-howto17163697
Ref: 14e817163697
Ref: howto/cporting porting-extension-modules-to-python-317163697
Ref: 568c17163697
Ref: howto/cporting translation-repo17163697
Ref: 568d17163697
Ref: Porting Extension Modules to Python 3-Footnote-117164488
Ref: Porting Extension Modules to Python 3-Footnote-217164539
Node: Curses Programming with Python17164596
Ref: howto/curses doc17164747
Ref: 568e17164747
Ref: howto/curses curses-howto17164747
Ref: 344517164747
Ref: howto/curses curses-programming-with-python17164747
Ref: 568f17164747
Ref: howto/curses translation-repo17164747
Ref: 569017164747
Node: What is curses?17165156
Ref: howto/curses what-is-curses17165287
Ref: 569117165287
Ref: What is curses?-Footnote-117167641
Ref: What is curses?-Footnote-217167681
Node: The Python curses module17167725
Ref: howto/curses the-python-curses-module17167801
Ref: 569217167801
Node: Starting and ending a curses application17168628
Ref: howto/curses starting-and-ending-a-curses-application17168784
Ref: 569317168784
Node: Windows and Pads17172060
Ref: howto/curses windows-and-pads17172216
Ref: 569417172216
Node: Displaying Text17176772
Ref: howto/curses displaying-text17176898
Ref: 569517176898
Node: Attributes and Color17180694
Ref: howto/curses attributes-and-color17180766
Ref: 569617180766
Node: User Input17185325
Ref: howto/curses user-input17185455
Ref: 569717185455
Ref: User Input-Footnote-117189275
Node: For More Information17189315
Ref: howto/curses for-more-information17189421
Ref: 569817189421
Ref: For More Information-Footnote-117190921
Ref: For More Information-Footnote-217190958
Ref: For More Information-Footnote-317191022
Ref: For More Information-Footnote-417191066
Ref: For More Information-Footnote-517191128
Ref: For More Information-Footnote-617191180
Node: Descriptor Guide17191251
Ref: howto/descriptor doc17191422
Ref: 569917191422
Ref: howto/descriptor descriptor-guide17191422
Ref: 569a17191422
Ref: howto/descriptor descriptorhowto17191422
Ref: 16f417191422
Ref: howto/descriptor translation-repo17191422
Ref: 569b17191422
Node: Primer17192574
Ref: howto/descriptor primer17192668
Ref: 569c17192668
Node: Simple example A descriptor that returns a constant17193012
Ref: howto/descriptor simple-example-a-descriptor-that-returns-a-constant17193130
Ref: 569d17193130
Node: Dynamic lookups17194599
Ref: howto/descriptor dynamic-lookups17194744
Ref: 569e17194744
Node: Managed attributes17196153
Ref: howto/descriptor managed-attributes17196263
Ref: 569f17196263
Node: Customized names17198918
Ref: howto/descriptor customized-names17199029
Ref: 56a017199029
Node: Closing thoughts17201374
Ref: howto/descriptor closing-thoughts17201458
Ref: 56a117201458
Node: Complete Practical Example17202848
Ref: howto/descriptor complete-practical-example17202969
Ref: 56a217202969
Node: Validator class17203232
Ref: howto/descriptor validator-class17203336
Ref: 56a317203336
Node: Custom validators17204362
Ref: howto/descriptor custom-validators17204496
Ref: 56a417204496
Ref: Custom validators-Footnote-117207126
Node: Practical application17207195
Ref: howto/descriptor practical-application17207305
Ref: 56a517207305
Node: Technical Tutorial17208693
Ref: howto/descriptor technical-tutorial17208831
Ref: 56a617208831
Node: Abstract17209263
Ref: howto/descriptor abstract17209362
Ref: 56a717209362
Node: Definition and introduction17209677
Ref: howto/descriptor definition-and-introduction17209804
Ref: 56a817209804
Node: Descriptor protocol17211044
Ref: howto/descriptor descriptor-protocol17211196
Ref: 56a917211196
Node: Overview of descriptor invocation17212480
Ref: howto/descriptor overview-of-descriptor-invocation17212632
Ref: 56aa17212632
Node: Invocation from an instance17213279
Ref: howto/descriptor invocation-from-an-instance17213435
Ref: 56ab17213435
Node: Invocation from a class17215952
Ref: howto/descriptor invocation-from-a-class17216096
Ref: 56ac17216096
Ref: Invocation from a class-Footnote-117216664
Node: Invocation from super17216737
Ref: howto/descriptor invocation-from-super17216881
Ref: 56ad17216881
Ref: Invocation from super-Footnote-117217515
Ref: Invocation from super-Footnote-217217588
Node: Summary of invocation logic17217668
Ref: howto/descriptor summary-of-invocation-logic17217816
Ref: 56ae17217816
Node: Automatic name notification17218820
Ref: howto/descriptor automatic-name-notification17218958
Ref: 56af17218958
Ref: Automatic name notification-Footnote-117219842
Node: ORM example17219915
Ref: howto/descriptor orm-example17220017
Ref: 56b017220017
Ref: ORM example-Footnote-117222030
Ref: ORM example-Footnote-217222102
Node: Pure Python Equivalents17222155
Ref: howto/descriptor pure-python-equivalents17222258
Ref: 56b117222258
Node: Properties17222731
Ref: howto/descriptor properties17222831
Ref: 56b217222831
Node: Functions and methods17225668
Ref: howto/descriptor functions-and-methods17225793
Ref: 56b317225793
Node: Kinds of methods17229065
Ref: howto/descriptor kinds-of-methods17229194
Ref: 56b417229194
Node: Static methods17230436
Ref: howto/descriptor static-methods17230557
Ref: 56b517230557
Node: Class methods17232746
Ref: howto/descriptor class-methods17232879
Ref: 56b617232879
Node: Member objects and __slots__17234935
Ref: howto/descriptor member-objects-and-slots17235045
Ref: 56b717235045
Ref: Member objects and __slots__-Footnote-117242668
Node: Debugging C API extensions and CPython Internals with GDB17242724
Ref: howto/gdb_helpers doc17242875
Ref: 56b817242875
Ref: howto/gdb_helpers debugging-c-api-extensions-and-cpython-internals-with-gdb17242875
Ref: 56b917242875
Ref: howto/gdb_helpers gdb17242875
Ref: 56ba17242875
Ref: howto/gdb_helpers translation-repo17242875
Ref: 56bb17242875
Ref: Debugging C API extensions and CPython Internals with GDB-Footnote-117244277
Ref: Debugging C API extensions and CPython Internals with GDB-Footnote-217244313
Node: Prerequisites17244367
Ref: howto/gdb_helpers prerequisites17244525
Ref: 56bc17244525
Node: Setup with Python built from source17245166
Ref: howto/gdb_helpers setup-with-python-built-from-source17245296
Ref: 56bd17245296
Node: Setup for Python from a Linux distro17246067
Ref: howto/gdb_helpers setup-for-python-from-a-linux-distro17246197
Ref: 56be17246197
Node: Using the Debug build and Development mode17246845
Ref: howto/gdb_helpers using-the-debug-build-and-development-mode17247042
Ref: 56bf17247042
Node: Using the python-gdb extension17247646
Ref: howto/gdb_helpers using-the-python-gdb-extension17247851
Ref: 56c017247851
Node: Pretty-printers17248157
Ref: howto/gdb_helpers pretty-printers17248255
Ref: 56c117248255
Node: py-list17252786
Ref: howto/gdb_helpers py-list17252910
Ref: 56c217252910
Node: py-up and py-down17253800
Ref: howto/gdb_helpers py-up-and-py-down17253914
Ref: 56c317253914
Node: py-bt17258639
Ref: howto/gdb_helpers py-bt17258754
Ref: 56c417258754
Node: py-print17261009
Ref: howto/gdb_helpers py-print17261116
Ref: 56c517261116
Node: py-locals17261865
Ref: howto/gdb_helpers py-locals17261958
Ref: 56c617261958
Node: Use with GDB commands17262861
Ref: howto/gdb_helpers use-with-gdb-commands17263015
Ref: 56c717263015
Node: Enum HOWTO17269036
Ref: howto/enum doc17269199
Ref: 56c817269199
Ref: howto/enum enum-howto17269199
Ref: 56c917269199
Ref: howto/enum id117269199
Ref: 56ca17269199
Ref: howto/enum translation-repo17269199
Ref: 56cb17269199
Ref: howto/enum enum-basic-tutorial17269230
Ref: 2a0a17269230
Node: Programmatic access to enumeration members and their attributes17275179
Ref: howto/enum enum-advanced-tutorial17275333
Ref: 2a0b17275333
Ref: howto/enum programmatic-access-to-enumeration-members-and-their-attributes17275333
Ref: 56cc17275333
Node: Duplicating enum members and values17276085
Ref: howto/enum duplicating-enum-members-and-values17276282
Ref: 56cd17276282
Node: Ensuring unique enumeration values17277510
Ref: howto/enum ensuring-unique-enumeration-values17277666
Ref: 56ce17277666
Node: Using automatic values17278220
Ref: howto/enum using-automatic-values17278353
Ref: 56cf17278353
Node: Iteration<2>17279290
Ref: howto/enum iteration17279403
Ref: 56d017279403
Node: Comparisons<2>17280665
Ref: howto/enum comparisons17280802
Ref: 56d117280802
Node: Allowed members and attributes of enumerations17281925
Ref: howto/enum allowed-members-and-attributes-of-enumerations17282077
Ref: 56d317282077
Node: Restricted Enum subclassing17284225
Ref: howto/enum restricted-enum-subclassing17284380
Ref: 56d717284380
Node: Dataclass support17285494
Ref: howto/enum dataclass-support17285611
Ref: 56d917285611
Ref: howto/enum enum-dataclass-support17285611
Ref: 1ae117285611
Node: Pickling17286986
Ref: howto/enum pickling17287093
Ref: 56da17287093
Node: Functional API<3>17288032
Ref: howto/enum functional-api17288142
Ref: 56d417288142
Node: Derived Enumerations17291543
Ref: howto/enum derived-enumerations17291676
Ref: 56db17291676
Node: IntEnum17291799
Ref: howto/enum intenum17291879
Ref: 56d217291879
Node: StrEnum17293004
Ref: howto/enum strenum17293100
Ref: 56dc17293100
Node: IntFlag17293407
Ref: howto/enum intflag17293500
Ref: 56dd17293500
Node: Flag17295864
Ref: howto/enum flag17295956
Ref: 56de17295956
Node: Others17298246
Ref: howto/enum others17298322
Ref: 56df17298322
Node: When to use __new__ vs __init__17300362
Ref: howto/enum new-vs-init17300512
Ref: 56d617300512
Ref: howto/enum when-to-use-new-vs-init17300512
Ref: 56e017300512
Node: Finer Points17301816
Ref: howto/enum finer-points17301896
Ref: 56e117301896
Node: Supported __dunder__ names<2>17302303
Ref: howto/enum supported-dunder-names17302417
Ref: 56e217302417
Node: Supported _sunder_ names<2>17302852
Ref: howto/enum supported-sunder-names17302990
Ref: 56e317302990
Node: _Private__names17305068
Ref: howto/enum private-names17305193
Ref: 56e517305193
Node: Enum member type17305368
Ref: howto/enum enum-member-type17305519
Ref: 56e617305519
Node: Creating members that are mixed with other data types17306007
Ref: howto/enum creating-members-that-are-mixed-with-other-data-types17306184
Ref: 56e717306184
Node: Boolean value of Enum classes and members17306719
Ref: howto/enum boolean-value-of-enum-classes-and-members17306905
Ref: 56e817306905
Node: Enum classes with methods17307470
Ref: howto/enum enum-classes-with-methods17307628
Ref: 56e917307628
Node: Combining members of Flag17308168
Ref: howto/enum combining-members-of-flag17308309
Ref: 56ea17308309
Node: Flag and IntFlag minutia17308871
Ref: howto/enum flag-and-intflag-minutia17308978
Ref: 56eb17308978
Node: How are Enums and Flags different?17311514
Ref: howto/enum enum-class-differences17311657
Ref: 2a0d17311657
Ref: howto/enum how-are-enums-and-flags-different17311657
Ref: 56ec17311657
Node: Enum Classes17311992
Ref: howto/enum enum-classes17312096
Ref: 56ed17312096
Node: Flag Classes17312686
Ref: howto/enum flag-classes17312825
Ref: 56ee17312825
Node: Enum Members aka instances17313191
Ref: howto/enum enum-members-aka-instances17313330
Ref: 56ef17313330
Node: Flag Members17313718
Ref: howto/enum flag-members17313836
Ref: 56f017313836
Node: Enum Cookbook17314471
Ref: howto/enum enum-cookbook17314603
Ref: 2a0c17314603
Ref: howto/enum id217314603
Ref: 56f117314603
Node: Omitting values17315068
Ref: howto/enum omitting-values17315153
Ref: 56f217315153
Node: Using auto17315947
Ref: howto/enum using-auto17316030
Ref: 56f317316030
Node: Using object17316282
Ref: howto/enum using-object17316400
Ref: 56f417316400
Node: Using a descriptive string17317053
Ref: howto/enum using-a-descriptive-string17317183
Ref: 56f517317183
Node: Using a custom __new__17317470
Ref: howto/enum using-a-custom-new17317579
Ref: 56f617317579
Node: OrderedEnum17319458
Ref: howto/enum orderedenum17319569
Ref: 56d817319569
Node: DuplicateFreeEnum17320749
Ref: howto/enum duplicatefreeenum17320859
Ref: 56f717320859
Node: MultiValueEnum17321939
Ref: howto/enum multivalueenum17322044
Ref: 56e417322044
Node: Planet17322627
Ref: howto/enum planet17322725
Ref: 56d517322725
Node: TimePeriod17323786
Ref: howto/enum enum-time-period17323861
Ref: 2a2317323861
Ref: howto/enum timeperiod17323861
Ref: 56f817323861
Node: Subclassing EnumType17324483
Ref: howto/enum enumtype-examples17324572
Ref: 2a1317324572
Ref: howto/enum subclassing-enumtype17324572
Ref: 56f917324572
Node: Functional Programming HOWTO17324836
Ref: howto/functional doc17324955
Ref: 56fa17324955
Ref: howto/functional functional-howto17324955
Ref: 56fb17324955
Ref: howto/functional functional-programming-howto17324955
Ref: 56fc17324955
Ref: howto/functional translation-repo17324955
Ref: 56fd17324955
Node: Introduction<14>17325759
Ref: howto/functional introduction17325858
Ref: 56fe17325858
Node: Formal provability17330557
Ref: howto/functional formal-provability17330647
Ref: 570017330647
Node: Modularity17332561
Ref: howto/functional modularity17332689
Ref: 570117332689
Node: Ease of debugging and testing17333094
Ref: howto/functional ease-of-debugging-and-testing17333217
Ref: 570217333217
Node: Composability17333952
Ref: howto/functional composability17334056
Ref: 570317334056
Node: Iterators17334779
Ref: howto/functional functional-howto-iterators17334932
Ref: 56ff17334932
Ref: howto/functional iterators17334932
Ref: 570417334932
Node: Data Types That Support Iterators17338301
Ref: howto/functional data-types-that-support-iterators17338380
Ref: 570517338380
Node: Generator expressions and list comprehensions17340344
Ref: howto/functional generator-expressions-and-list-comprehensions17340491
Ref: 570617340491
Node: Generators17345040
Ref: howto/functional generators17345199
Ref: 570717345199
Ref: Generators-Footnote-117349058
Node: Passing values into a generator17349139
Ref: howto/functional passing-values-into-a-generator17349217
Ref: 570817349217
Ref: Passing values into a generator-Footnote-117353181
Node: Built-in functions<2>17353223
Ref: howto/functional built-in-functions17353357
Ref: 570917353357
Ref: Built-in functions<2>-Footnote-117357403
Node: The itertools module17357457
Ref: howto/functional the-itertools-module17357601
Ref: 570a17357601
Node: Creating new iterators17358344
Ref: howto/functional creating-new-iterators17358461
Ref: 570b17358461
Node: Calling functions on elements17361145
Ref: howto/functional calling-functions-on-elements17361289
Ref: 570c17361289
Node: Selecting elements17362102
Ref: howto/functional selecting-elements17362246
Ref: 570d17362246
Node: Combinatoric functions17363737
Ref: howto/functional combinatoric-functions17363869
Ref: 570e17363869
Node: Grouping elements17366202
Ref: howto/functional grouping-elements17366307
Ref: 570f17366307
Node: The functools module17367857
Ref: howto/functional the-functools-module17368021
Ref: 571017368021
Node: The operator module17371626
Ref: howto/functional the-operator-module17371702
Ref: 571117371702
Node: Small functions and the lambda expression17372514
Ref: howto/functional small-functions-and-the-lambda-expression17372695
Ref: 571217372695
Node: Revision History and Acknowledgements17375553
Ref: howto/functional revision-history-and-acknowledgements17375727
Ref: 571317375727
Node: References<2>17376504
Ref: howto/functional references17376628
Ref: 571417376628
Node: General17376732
Ref: howto/functional general17376813
Ref: 571517376813
Node: Python-specific17377874
Ref: howto/functional python-specific17377984
Ref: 571617377984
Ref: Python-specific-Footnote-117378456
Ref: Python-specific-Footnote-217378507
Ref: Python-specific-Footnote-317378560
Node: Python documentation17378613
Ref: howto/functional python-documentation17378707
Ref: 571717378707
Ref: Python documentation-Footnote-117379102
Ref: Python documentation-Footnote-217379144
Node: Logging HOWTO17379186
Ref: howto/logging doc17379311
Ref: 571817379311
Ref: howto/logging id117379311
Ref: 571917379311
Ref: howto/logging logging-howto17379311
Ref: 571a17379311
Ref: howto/logging translation-repo17379311
Ref: 571b17379311
Ref: howto/logging logging-basic-tutorial17379404
Ref: 13fd17379404
Node: Basic Logging Tutorial17379784
Ref: howto/logging basic-logging-tutorial17379890
Ref: 571d17379890
Node: When to use logging17380640
Ref: howto/logging when-to-use-logging17380743
Ref: 571e17380743
Node: A simple example17384751
Ref: howto/logging a-simple-example17384880
Ref: 571f17384880
Ref: howto/logging howto-minimal-example17384880
Ref: 572017384880
Node: Logging to a file17386119
Ref: howto/logging logging-to-a-file17386250
Ref: 572117386250
Node: Logging variable data17389322
Ref: howto/logging logging-variable-data17389478
Ref: 572217389478
Node: Changing the format of displayed messages17390295
Ref: howto/logging changing-the-format-of-displayed-messages17390470
Ref: 572317390470
Node: Displaying the date/time in messages17391464
Ref: howto/logging displaying-the-date-time-in-messages17391628
Ref: 572417391628
Ref: Displaying the date/time in messages-Footnote-117392679
Node: Next Steps17392738
Ref: howto/logging next-steps17392852
Ref: 572517392852
Ref: Next Steps-Footnote-117393785
Node: Advanced Logging Tutorial17393829
Ref: howto/logging advanced-logging-tutorial17393961
Ref: 572617393961
Ref: howto/logging logging-advanced-tutorial17393961
Ref: 13fe17393961
Node: Logging Flow17397349
Ref: howto/logging logging-flow17397439
Ref: 572717397439
Node: Loggers17397634
Ref: howto/logging loggers17397741
Ref: 572817397741
Node: Handlers17402024
Ref: howto/logging handler-basic17402129
Ref: 572917402129
Ref: howto/logging handlers17402129
Ref: 572a17402129
Node: Formatters17404204
Ref: howto/logging formatters17404321
Ref: 572c17404321
Ref: howto/logging logging logging Formatter __init__17404769
Ref: 572d17404769
Node: Configuring Logging17406483
Ref: howto/logging configuring-logging17406636
Ref: 572e17406636
Node: What happens if no configuration is provided17413193
Ref: howto/logging what-happens-if-no-configuration-is-provided17413369
Ref: 572f17413369
Node: Configuring Logging for a Library17414635
Ref: howto/logging configuring-logging-for-a-library17414783
Ref: 573017414783
Ref: howto/logging library-config17414783
Ref: 31bd17414783
Node: Logging Levels<2>17417652
Ref: howto/logging logging-levels17417777
Ref: 573117417777
Node: Custom Levels17420640
Ref: howto/logging custom-levels17420707
Ref: 318517420707
Ref: howto/logging id217420707
Ref: 573217420707
Node: Useful Handlers17421420
Ref: howto/logging id317421552
Ref: 573317421552
Ref: howto/logging useful-handlers17421552
Ref: 572b17421552
Node: Exceptions raised during logging17425584
Ref: howto/logging exceptions-raised-during-logging17425734
Ref: 573417425734
Ref: howto/logging logging-exceptions17425734
Ref: 573517425734
Node: Using arbitrary objects as messages17426907
Ref: howto/logging arbitrary-object-messages17427054
Ref: 317117427054
Ref: howto/logging using-arbitrary-objects-as-messages17427054
Ref: 573617427054
Node: Optimization17427667
Ref: howto/logging optimization17427797
Ref: 573717427797
Node: Other resources17431427
Ref: howto/logging other-resources17431513
Ref: 573817431513
Ref: howto/logging tutorial-ref-links17431513
Ref: 571c17431513
Node: Logging Cookbook17431859
Ref: howto/logging-cookbook doc17431980
Ref: 573917431980
Ref: howto/logging-cookbook id117431980
Ref: 573a17431980
Ref: howto/logging-cookbook logging-cookbook17431980
Ref: 13ff17431980
Ref: howto/logging-cookbook translation-repo17431980
Ref: 573b17431980
Node: Using logging in multiple modules17434123
Ref: howto/logging-cookbook using-logging-in-multiple-modules17434247
Ref: 573d17434247
Node: Logging from multiple threads17437819
Ref: howto/logging-cookbook logging-from-multiple-threads17437984
Ref: 573e17437984
Node: Multiple handlers and formatters17439729
Ref: howto/logging-cookbook multiple-handlers-and-formatters17439893
Ref: 573f17439893
Node: Logging to multiple destinations17442054
Ref: howto/logging-cookbook logging-to-multiple-destinations17442214
Ref: 574017442214
Ref: howto/logging-cookbook multiple-destinations17442214
Ref: 574117442214
Node: Custom handling of levels17445383
Ref: howto/logging-cookbook custom-handling-of-levels17445539
Ref: 574217445539
Ref: howto/logging-cookbook custom-level-handling17445539
Ref: 574317445539
Node: Configuration server example17451411
Ref: howto/logging-cookbook configuration-server-example17451567
Ref: 574417451567
Node: Dealing with handlers that block17453127
Ref: howto/logging-cookbook blocking-handlers17453311
Ref: 392417453311
Ref: howto/logging-cookbook dealing-with-handlers-that-block17453311
Ref: 574517453311
Node: Sending and receiving logging events across a network17457898
Ref: howto/logging-cookbook network-logging17458106
Ref: 574617458106
Ref: howto/logging-cookbook sending-and-receiving-logging-events-across-a-network17458106
Ref: 574717458106
Node: Running a logging socket listener in production17463642
Ref: howto/logging-cookbook running-a-logging-socket-listener-in-production17463779
Ref: 574817463779
Ref: Running a logging socket listener in production-Footnote-117467890
Ref: Running a logging socket listener in production-Footnote-217467922
Ref: Running a logging socket listener in production-Footnote-317467994
Ref: Running a logging socket listener in production-Footnote-417468024
Node: Adding contextual information to your logging output17468096
Ref: howto/logging-cookbook adding-contextual-information-to-your-logging-output17468290
Ref: 574917468290
Ref: howto/logging-cookbook context-info17468290
Ref: 317817468290
Node: Using LoggerAdapters to impart contextual information17469389
Ref: howto/logging-cookbook using-loggeradapters-to-impart-contextual-information17469586
Ref: 574a17469586
Node: Using objects other than dicts to pass contextual information17472864
Ref: howto/logging-cookbook using-objects-other-than-dicts-to-pass-contextual-information17473015
Ref: 574b17473015
Node: Using Filters to impart contextual information17473479
Ref: howto/logging-cookbook filters-contextual17473676
Ref: 316d17473676
Ref: howto/logging-cookbook using-filters-to-impart-contextual-information17473676
Ref: 574c17473676
Node: Use of contextvars17477491
Ref: howto/logging-cookbook use-of-contextvars17477676
Ref: 574d17477676
Node: Imparting contextual information in handlers17487254
Ref: howto/logging-cookbook imparting-contextual-information-in-handlers17487435
Ref: 574e17487435
Node: Logging to a single file from multiple processes17488382
Ref: howto/logging-cookbook logging-to-a-single-file-from-multiple-processes17488564
Ref: 574f17488564
Ref: howto/logging-cookbook multiple-processes17488564
Ref: 575017488564
Node: Using concurrent futures ProcessPoolExecutor17498843
Ref: howto/logging-cookbook using-concurrent-futures-processpoolexecutor17499032
Ref: 575117499032
Node: Deploying Web applications using Gunicorn and uWSGI17500038
Ref: howto/logging-cookbook deploying-web-applications-using-gunicorn-and-uwsgi17500227
Ref: 575217500227
Ref: Deploying Web applications using Gunicorn and uWSGI-Footnote-117500888
Ref: Deploying Web applications using Gunicorn and uWSGI-Footnote-217500918
Node: Using file rotation17500971
Ref: howto/logging-cookbook using-file-rotation17501145
Ref: 575317501145
Node: Use of alternative formatting styles17503048
Ref: howto/logging-cookbook format-styles17503195
Ref: 575417503195
Ref: howto/logging-cookbook use-of-alternative-formatting-styles17503195
Ref: 575517503195
Node: Customizing LogRecord17510340
Ref: howto/logging-cookbook custom-logrecord17510528
Ref: 575617510528
Ref: howto/logging-cookbook customizing-logrecord17510528
Ref: 575717510528
Node: Subclassing QueueHandler and QueueListener- a ZeroMQ example17514452
Ref: howto/logging-cookbook subclassing-queuehandler-and-queuelistener-a-zeromq-example17514663
Ref: 575817514663
Ref: howto/logging-cookbook zeromq-handlers17514663
Ref: 575917514663
Node: Subclass QueueHandler17514863
Ref: howto/logging-cookbook subclass-queuehandler17515012
Ref: 575a17515012
Node: Subclass QueueListener17516321
Ref: howto/logging-cookbook subclass-queuelistener17516470
Ref: 575b17516470
Node: Subclassing QueueHandler and QueueListener- a pynng example17517215
Ref: howto/logging-cookbook pynng-handlers17517446
Ref: 575c17517446
Ref: howto/logging-cookbook subclassing-queuehandler-and-queuelistener-a-pynng-example17517446
Ref: 575d17517446
Ref: Subclassing QueueHandler and QueueListener- a pynng example-Footnote-117518072
Ref: Subclassing QueueHandler and QueueListener- a pynng example-Footnote-217518112
Node: Subclass QueueListener<2>17518145
Ref: howto/logging-cookbook id317518299
Ref: 575e17518299
Node: Subclass QueueHandler<2>17520275
Ref: howto/logging-cookbook id417520429
Ref: 575f17520429
Node: An example dictionary-based configuration17524143
Ref: howto/logging-cookbook an-example-dictionary-based-configuration17524376
Ref: 576017524376
Ref: An example dictionary-based configuration-Footnote-117526310
Ref: An example dictionary-based configuration-Footnote-217526396
Node: Using a rotator and namer to customize log rotation processing17526482
Ref: howto/logging-cookbook cookbook-rotator-namer17526696
Ref: 31ca17526696
Ref: howto/logging-cookbook using-a-rotator-and-namer-to-customize-log-rotation-processing17526696
Ref: 576117526696
Node: A more elaborate multiprocessing example17528097
Ref: howto/logging-cookbook a-more-elaborate-multiprocessing-example17528323
Ref: 576217528323
Node: Inserting a BOM into messages sent to a SysLogHandler17537949
Ref: howto/logging-cookbook inserting-a-bom-into-messages-sent-to-a-sysloghandler17538144
Ref: 576317538144
Ref: Inserting a BOM into messages sent to a SysLogHandler-Footnote-117540309
Ref: Inserting a BOM into messages sent to a SysLogHandler-Footnote-217540368
Ref: Inserting a BOM into messages sent to a SysLogHandler-Footnote-317540437
Ref: Inserting a BOM into messages sent to a SysLogHandler-Footnote-417540496
Node: Implementing structured logging17540555
Ref: howto/logging-cookbook implementing-structured-logging17540746
Ref: 576417540746
Node: Customizing handlers with dictConfig17543280
Ref: howto/logging-cookbook custom-handlers17543480
Ref: 576517543480
Ref: howto/logging-cookbook customizing-handlers-with-dictconfig17543480
Ref: 576617543480
Node: Using particular formatting styles throughout your application17548676
Ref: howto/logging-cookbook formatting-styles17548880
Ref: 316117548880
Ref: howto/logging-cookbook using-particular-formatting-styles-throughout-your-application17548880
Ref: 576717548880
Node: Using LogRecord factories17550883
Ref: howto/logging-cookbook using-logrecord-factories17551044
Ref: 576817551044
Node: Using custom message objects17552021
Ref: howto/logging-cookbook using-custom-message-objects17552182
Ref: 576917552182
Node: Configuring filters with dictConfig17554888
Ref: howto/logging-cookbook configuring-filters-with-dictconfig17555087
Ref: 576a17555087
Ref: howto/logging-cookbook filters-dictconfig17555087
Ref: 576b17555087
Node: Customized exception formatting17558054
Ref: howto/logging-cookbook custom-format-exception17558216
Ref: 576c17558216
Ref: howto/logging-cookbook customized-exception-formatting17558216
Ref: 576d17558216
Node: Speaking logging messages17560246
Ref: howto/logging-cookbook speaking-logging-messages17560433
Ref: 576e17560433
Ref: howto/logging-cookbook spoken-messages17560433
Ref: 576f17560433
Node: Buffering logging messages and outputting them conditionally17562595
Ref: howto/logging-cookbook buffered-logging17562799
Ref: 577017562799
Ref: howto/logging-cookbook buffering-logging-messages-and-outputting-them-conditionally17562799
Ref: 577117562799
Node: Sending logging messages to email with buffering17568375
Ref: howto/logging-cookbook buffered-smtp17568602
Ref: 577217568602
Ref: howto/logging-cookbook sending-logging-messages-to-email-with-buffering17568602
Ref: 577317568602
Node: Formatting times using UTC GMT via configuration17572168
Ref: howto/logging-cookbook formatting-times-using-utc-gmt-via-configuration17572380
Ref: 577417572380
Ref: howto/logging-cookbook utc-formatting17572380
Ref: 577517572380
Node: Using a context manager for selective logging17574281
Ref: howto/logging-cookbook context-manager17574479
Ref: 577617574479
Ref: howto/logging-cookbook using-a-context-manager-for-selective-logging17574479
Ref: 577717574479
Node: A CLI application starter template17579059
Ref: howto/logging-cookbook a-cli-application-starter-template17579229
Ref: 577817579229
Ref: howto/logging-cookbook starter-template17579229
Ref: 577917579229
Node: A Qt GUI for logging17585210
Ref: howto/logging-cookbook a-qt-gui-for-logging17585373
Ref: 577a17585373
Ref: howto/logging-cookbook qt-gui17585373
Ref: 577b17585373
Ref: A Qt GUI for logging-Footnote-117595676
Ref: A Qt GUI for logging-Footnote-217595703
Ref: A Qt GUI for logging-Footnote-317595745
Node: Logging to syslog with RFC5424 support17595785
Ref: howto/logging-cookbook logging-to-syslog-with-rfc5424-support17595957
Ref: 577c17595957
Ref: Logging to syslog with RFC5424 support-Footnote-117599687
Ref: Logging to syslog with RFC5424 support-Footnote-217599746
Node: How to treat a logger like an output stream17599805
Ref: howto/logging-cookbook how-to-treat-a-logger-like-an-output-stream17600007
Ref: 577d17600007
Node: How to uniformly handle newlines in logging output17604683
Ref: howto/logging-cookbook how-to-uniformly-handle-newlines-in-logging-output17604864
Ref: 577e17604864
Ref: How to uniformly handle newlines in logging output-Footnote-117608394
Node: Patterns to avoid17608456
Ref: howto/logging-cookbook patterns-to-avoid17608612
Ref: 577f17608612
Node: Opening the same log file multiple times17609164
Ref: howto/logging-cookbook opening-the-same-log-file-multiple-times17609335
Ref: 578017609335
Node: Using loggers as attributes in a class or passing them as parameters17611256
Ref: howto/logging-cookbook using-loggers-as-attributes-in-a-class-or-passing-them-as-parameters17611499
Ref: 578117611499
Node: Adding handlers other than NullHandler to a logger in a library17612185
Ref: howto/logging-cookbook adding-handlers-other-than-nullhandler-to-a-logger-in-a-library17612413
Ref: 578217612413
Node: Creating a lot of loggers17612853
Ref: howto/logging-cookbook creating-a-lot-of-loggers17613004
Ref: 578317613004
Node: Other resources<2>17613559
Ref: howto/logging-cookbook cookbook-ref-links17613656
Ref: 573c17613656
Ref: howto/logging-cookbook other-resources17613656
Ref: 578417613656
Node: Regular Expression HOWTO17614032
Ref: howto/regex doc17614164
Ref: 578517614164
Ref: howto/regex regex-howto17614164
Ref: 274517614164
Ref: howto/regex regular-expression-howto17614164
Ref: 578617614164
Ref: howto/regex translation-repo17614164
Ref: 578717614164
Node: Introduction<15>17614661
Ref: howto/regex introduction17614762
Ref: 578817614762
Node: Simple Patterns17616363
Ref: howto/regex simple-patterns17616498
Ref: 578917616498
Node: Matching Characters17616993
Ref: howto/regex matching-characters17617089
Ref: 578a17617089
Node: Repeating Things17621738
Ref: howto/regex repeating-things17621834
Ref: 578b17621834
Node: Using Regular Expressions17626912
Ref: howto/regex using-regular-expressions17627049
Ref: 578c17627049
Node: Compiling Regular Expressions17627542
Ref: howto/regex compiling-regular-expressions17627662
Ref: 578d17627662
Node: The Backslash Plague17628879
Ref: howto/regex id117629026
Ref: 578e17629026
Ref: howto/regex the-backslash-plague17629026
Ref: 578f17629026
Node: Performing Matches17631912
Ref: howto/regex performing-matches17632055
Ref: 579017632055
Node: Module-Level Functions<3>17637601
Ref: howto/regex module-level-functions17637741
Ref: 579117637741
Node: Compilation Flags17638945
Ref: howto/regex compilation-flags17639058
Ref: 579217639058
Node: More Pattern Power17646206
Ref: howto/regex more-pattern-power17646345
Ref: 579417646345
Node: More Metacharacters17646710
Ref: howto/regex id217646801
Ref: 579517646801
Ref: howto/regex more-metacharacters17646801
Ref: 579317646801
Node: Grouping17651563
Ref: howto/regex grouping17651693
Ref: 579617651693
Node: Non-capturing and Named Groups17655170
Ref: howto/regex non-capturing-and-named-groups17655301
Ref: 579717655301
Node: Lookahead Assertions17660438
Ref: howto/regex lookahead-assertions17660552
Ref: 579817660552
Node: Modifying Strings17664221
Ref: howto/regex modifying-strings17664350
Ref: 579917664350
Node: Splitting Strings17665342
Ref: howto/regex splitting-strings17665443
Ref: 579a17665443
Node: Search and Replace<2>17667762
Ref: howto/regex search-and-replace17667863
Ref: 579b17667863
Node: Common Problems17672352
Ref: howto/regex common-problems17672471
Ref: 579c17672471
Node: Use String Methods17672909
Ref: howto/regex use-string-methods17673007
Ref: 579d17673007
Node: match versus search17674723
Ref: howto/regex match-versus-search17674854
Ref: 579e17674854
Node: Greedy versus Non-Greedy17676488
Ref: howto/regex greedy-versus-non-greedy17676617
Ref: 579f17676617
Node: Using re VERBOSE17678541
Ref: howto/regex using-re-verbose17678642
Ref: 57a017678642
Node: Feedback17680169
Ref: howto/regex feedback17680262
Ref: 57a117680262
Node: Socket Programming HOWTO17681045
Ref: howto/sockets doc17681179
Ref: 57a217681179
Ref: howto/sockets socket-howto17681179
Ref: 398717681179
Ref: howto/sockets socket-programming-howto17681179
Ref: 57a317681179
Ref: howto/sockets translation-repo17681179
Ref: 57a417681179
Node: Sockets17681777
Ref: howto/sockets sockets17681871
Ref: 57a517681871
Node: History17683019
Ref: howto/sockets history17683070
Ref: 57a617683070
Node: Creating a Socket17683645
Ref: howto/sockets creating-a-socket17683762
Ref: 57a717683762
Node: IPC17687007
Ref: howto/sockets ipc17687064
Ref: 57a817687064
Node: Using a Socket17687512
Ref: howto/sockets using-a-socket17687635
Ref: 57a917687635
Node: Binary Data17693766
Ref: howto/sockets binary-data17693828
Ref: 57aa17693828
Ref: Binary Data-Footnote-117695107
Node: Disconnecting17695167
Ref: howto/sockets disconnecting17695293
Ref: 57ab17695293
Node: When Sockets Die17696761
Ref: howto/sockets when-sockets-die17696827
Ref: 57ac17696827
Node: Non-blocking Sockets17697706
Ref: howto/sockets non-blocking-sockets17697809
Ref: 57ad17697809
Node: Sorting Techniques17701628
Ref: howto/sorting doc17701751
Ref: 57ae17701751
Ref: howto/sorting sorting-techniques17701751
Ref: 57af17701751
Ref: howto/sorting sortinghowto17701751
Ref: 25bb17701751
Ref: howto/sorting translation-repo17701751
Ref: 57b017701751
Node: Sorting Basics17702440
Ref: howto/sorting sorting-basics17702531
Ref: 57b117702531
Node: Key Functions17703331
Ref: howto/sorting key-functions17703488
Ref: 57b217703488
Node: Operator Module Functions and Partial Function Evaluation17705512
Ref: howto/sorting operator-module-functions-and-partial-function-evaluation17705679
Ref: 57b317705679
Ref: Operator Module Functions and Partial Function Evaluation-Footnote-117707509
Node: Ascending and Descending17707553
Ref: howto/sorting ascending-and-descending17707739
Ref: 57b417707739
Node: Sort Stability and Complex Sorts17708274
Ref: howto/sorting sort-stability-and-complex-sorts17708427
Ref: 57b517708427
Ref: Sort Stability and Complex Sorts-Footnote-117710060
Ref: Sort Stability and Complex Sorts-Footnote-217710126
Node: Decorate-Sort-Undecorate17710172
Ref: howto/sorting decorate-sort-undecorate17710321
Ref: 57b617710321
Ref: Decorate-Sort-Undecorate-Footnote-117711972
Node: Comparison Functions17712032
Ref: howto/sorting comparison-functions17712192
Ref: 57b717712192
Ref: Comparison Functions-Footnote-117713163
Node: Strategies For Unorderable Types and Values17713250
Ref: howto/sorting strategies-for-unorderable-types-and-values17713399
Ref: 57b817713399
Ref: Strategies For Unorderable Types and Values-Footnote-117715136
Node: Odds and Ends17715183
Ref: howto/sorting odds-and-ends17715325
Ref: 57b917715325
Ref: Odds and Ends-Footnote-117717569
Node: Partial Sorts17717611
Ref: howto/sorting partial-sorts17717701
Ref: 57ba17717701
Node: Unicode HOWTO17718788
Ref: howto/unicode doc17718942
Ref: 57bb17718942
Ref: howto/unicode id117718942
Ref: 57bc17718942
Ref: howto/unicode translation-repo17718942
Ref: 57bd17718942
Ref: howto/unicode unicode-howto17718942
Ref: 14ac17718942
Node: Introduction to Unicode17719342
Ref: howto/unicode introduction-to-unicode17719450
Ref: 57be17719450
Node: Definitions17719582
Ref: howto/unicode definitions17719671
Ref: 57bf17719671
Ref: Definitions-Footnote-117722733
Node: Encodings17722790
Ref: howto/unicode encodings17722901
Ref: 57c017722901
Node: References<3>17726578
Ref: howto/unicode references17726669
Ref: 57c117726669
Ref: References<3>-Footnote-117727542
Ref: References<3>-Footnote-217727574
Ref: References<3>-Footnote-317727615
Ref: References<3>-Footnote-417727667
Ref: References<3>-Footnote-517727714
Ref: References<3>-Footnote-617727888
Ref: References<3>-Footnote-717727945
Node: Python’s Unicode Support17727989
Ref: howto/unicode python-s-unicode-support17728138
Ref: 57c217728138
Node: The String Type17728505
Ref: howto/unicode the-string-type17728611
Ref: 57c317728611
Node: Converting to Bytes17731721
Ref: howto/unicode converting-to-bytes17731874
Ref: 57c417731874
Node: Unicode Literals in Python Source Code17733718
Ref: howto/unicode unicode-literals-in-python-source-code17733874
Ref: 57c517733874
Ref: Unicode Literals in Python Source Code-Footnote-117735979
Node: Unicode Properties17736021
Ref: howto/unicode id217736175
Ref: 57c617736175
Ref: howto/unicode unicode-properties17736175
Ref: 262f17736175
Ref: Unicode Properties-Footnote-117737926
Node: Comparing Strings17737996
Ref: howto/unicode comparing-strings17738139
Ref: 57c717738139
Node: Unicode Regular Expressions17740993
Ref: howto/unicode unicode-regular-expressions17741131
Ref: 57c817741131
Node: References<4>17742268
Ref: howto/unicode id317742380
Ref: 57c917742380
Ref: References<4>-Footnote-117743170
Ref: References<4>-Footnote-217743266
Ref: References<4>-Footnote-317743318
Node: Reading and Writing Unicode Data17743387
Ref: howto/unicode reading-and-writing-unicode-data17743533
Ref: 57ca17743533
Node: Unicode filenames17747239
Ref: howto/unicode unicode-filenames17747373
Ref: 57cb17747373
Node: Tips for Writing Unicode-aware Programs17749836
Ref: howto/unicode tips-for-writing-unicode-aware-programs17749992
Ref: 57cc17749992
Node: Converting Between File Encodings17751355
Ref: howto/unicode converting-between-file-encodings17751501
Ref: 57cd17751501
Node: Files in an Unknown Encoding17752270
Ref: howto/unicode files-in-an-unknown-encoding17752416
Ref: 57ce17752416
Node: References<5>17753317
Ref: howto/unicode id417753447
Ref: 57cf17753447
Ref: References<5>-Footnote-117754053
Ref: References<5>-Footnote-217754125
Ref: References<5>-Footnote-317754230
Node: Acknowledgements<10>17754299
Ref: howto/unicode acknowledgements17754410
Ref: 57d017754410
Node: HOWTO Fetch Internet Resources Using The urllib Package17754934
Ref: howto/urllib2 doc17755109
Ref: 57d117755109
Ref: howto/urllib2 howto-fetch-internet-resources-using-the-urllib-package17755109
Ref: 57d217755109
Ref: howto/urllib2 translation-repo17755109
Ref: 57d317755109
Ref: howto/urllib2 urllib-howto17755109
Ref: 3f7117755109
Ref: HOWTO Fetch Internet Resources Using The urllib Package-Footnote-117755500
Node: Introduction<16>17755539
Ref: howto/urllib2 introduction17755669
Ref: 57d417755669
Ref: Introduction<16>-Footnote-117757261
Ref: Introduction<16>-Footnote-217757378
Node: Fetching URLs17757437
Ref: howto/urllib2 fetching-urls17757595
Ref: 57d517757595
Node: Data17759828
Ref: howto/urllib2 data17759898
Ref: 57d617759898
Ref: Data-Footnote-117762547
Node: Headers17762616
Ref: howto/urllib2 headers17762686
Ref: 57d717762686
Ref: Headers-Footnote-117764198
Ref: Headers-Footnote-217764226
Ref: Headers-Footnote-317764436
Ref: Headers-Footnote-417764556
Node: Handling Exceptions17764675
Ref: howto/urllib2 handling-exceptions17764832
Ref: 57d917764832
Node: URLError17765334
Ref: howto/urllib2 urlerror17765416
Ref: 57da17765416
Node: HTTPError17765968
Ref: howto/urllib2 httperror17766073
Ref: 57db17766073
Ref: HTTPError-Footnote-117766962
Node: Error Codes17767021
Ref: howto/urllib2 error-codes17767078
Ref: 57dc17767078
Ref: Error Codes-Footnote-117769243
Node: Wrapping it Up17769302
Ref: howto/urllib2 wrapping-it-up17769390
Ref: 57dd17769390
Node: Number 117769622
Ref: howto/urllib2 number-117769698
Ref: 57de17769698
Node: Number 217770324
Ref: howto/urllib2 number-217770400
Ref: 57df17770400
Node: info and geturl17770932
Ref: howto/urllib2 info-and-geturl17771096
Ref: 57d817771096
Ref: info and geturl-Footnote-117772028
Node: Openers and Handlers17772066
Ref: howto/urllib2 openers-and-handlers17772231
Ref: 57e017772231
Node: Basic Authentication17773877
Ref: howto/urllib2 basic-authentication17774034
Ref: 57e117774034
Ref: Basic Authentication-Footnote-117777441
Node: Proxies17777558
Ref: howto/urllib2 proxies17777713
Ref: 57e217777713
Ref: Proxies-Footnote-117778745
Ref: Proxies-Footnote-217779047
Node: Sockets and Layers17779214
Ref: howto/urllib2 sockets-and-layers17779358
Ref: 57e317779358
Node: Footnotes17780377
Ref: howto/urllib2 footnotes17780505
Ref: 57e417780505
Node: An introduction to the ipaddress module17780593
Ref: howto/ipaddress doc17780802
Ref: 57e517780802
Ref: howto/ipaddress an-introduction-to-the-ipaddress-module17780802
Ref: 57e617780802
Ref: howto/ipaddress ipaddress-howto17780802
Ref: 41af17780802
Ref: howto/ipaddress translation-repo17780802
Ref: 57e717780802
Node: Creating Address/Network/Interface objects17781543
Ref: howto/ipaddress creating-address-network-interface-objects17781714
Ref: 57e817781714
Node: A Note on IP Versions17782139
Ref: howto/ipaddress a-note-on-ip-versions17782265
Ref: 57e917782265
Node: IP Host Addresses17783051
Ref: howto/ipaddress ip-host-addresses17783203
Ref: 57ea17783203
Node: Defining Networks17784386
Ref: howto/ipaddress defining-networks17784532
Ref: 57eb17784532
Node: Host Interfaces17786886
Ref: howto/ipaddress host-interfaces17787006
Ref: 57ec17787006
Node: Inspecting Address/Network/Interface Objects17788007
Ref: howto/ipaddress inspecting-address-network-interface-objects17788217
Ref: 57ed17788217
Node: Networks as lists of Addresses17790563
Ref: howto/ipaddress networks-as-lists-of-addresses17790745
Ref: 57ee17790745
Node: Comparisons<3>17791542
Ref: howto/ipaddress comparisons17791717
Ref: 57ef17791717
Node: Using IP Addresses with other modules17792074
Ref: howto/ipaddress using-ip-addresses-with-other-modules17792267
Ref: 57f017792267
Node: Getting more detail when instance creation fails17792696
Ref: howto/ipaddress getting-more-detail-when-instance-creation-fails17792866
Ref: 57f117792866
Node: Instrumenting CPython with DTrace and SystemTap17794922
Ref: howto/instrumentation doc17795118
Ref: 57f217795118
Ref: howto/instrumentation instrumentation17795118
Ref: e6817795118
Ref: howto/instrumentation instrumenting-cpython-with-dtrace-and-systemtap17795118
Ref: 57f317795118
Ref: howto/instrumentation translation-repo17795118
Ref: 57f417795118
Node: Enabling the static markers17796309
Ref: howto/instrumentation enabling-the-static-markers17796449
Ref: 57f517796449
Node: Static DTrace probes17800645
Ref: howto/instrumentation static-dtrace-probes17800818
Ref: 57f617800818
Node: Static SystemTap markers17803255
Ref: howto/instrumentation static-systemtap-markers17803425
Ref: 57f717803425
Node: Available static markers17805469
Ref: howto/instrumentation available-static-markers17805636
Ref: 57f817805636
Ref: howto/instrumentation static-markers17805636
Ref: db317805636
Node: SystemTap Tapsets17808184
Ref: howto/instrumentation systemtap-tapsets17808339
Ref: 57f917808339
Node: Examples<40>17809955
Ref: howto/instrumentation examples17810077
Ref: 57fa17810077
Node: Python support for the Linux perf profiler17811398
Ref: howto/perf_profiling doc17811581
Ref: 1a9417811581
Ref: howto/perf_profiling perf-profiling17811581
Ref: 4af17811581
Ref: howto/perf_profiling python-support-for-the-linux-perf-profiler17811581
Ref: 57fb17811581
Ref: howto/perf_profiling translation-repo17811581
Ref: 57fc17811581
Ref: Python support for the Linux perf profiler-Footnote-117819466
Node: How to enable perf profiling support17819503
Ref: howto/perf_profiling how-to-enable-perf-profiling-support17819657
Ref: 57fd17819657
Node: How to obtain the best results17820799
Ref: howto/perf_profiling how-to-obtain-the-best-results17820996
Ref: 57fe17820996
Node: How to work without frame pointers17821778
Ref: howto/perf_profiling how-to-work-without-frame-pointers17821930
Ref: 57ff17821930
Node: Annotations Best Practices17825799
Ref: howto/annotations doc17825962
Ref: 580017825962
Ref: howto/annotations annotations-best-practices17825962
Ref: 580117825962
Ref: howto/annotations annotations-howto17825962
Ref: 9db17825962
Ref: howto/annotations translation-repo17825962
Ref: 580217825962
Node: Accessing The Annotations Dict Of An Object In Python 3 10 And Newer17827322
Ref: howto/annotations accessing-the-annotations-dict-of-an-object-in-python-3-10-and-newer17827529
Ref: 580317827529
Node: Accessing The Annotations Dict Of An Object In Python 3 9 And Older17829424
Ref: howto/annotations accessing-the-annotations-dict-of-an-object-in-python-3-9-and-older17829686
Ref: 580417829686
Node: Manually Un-Stringizing Stringized Annotations17832080
Ref: howto/annotations manually-un-stringizing-stringized-annotations17832330
Ref: 580517832330
Ref: Manually Un-Stringizing Stringized Annotations-Footnote-117834667
Node: Best Practices For __annotations__ In Any Python Version17834709
Ref: howto/annotations best-practices-for-annotations-in-any-python-version17834914
Ref: 580617834914
Node: __annotations__ Quirks17835880
Ref: howto/annotations annotations-quirks17836030
Ref: 580717836030
Ref: __annotations__ Quirks-Footnote-117838584
Node: Isolating Extension Modules17838645
Ref: howto/isolating-extensions doc17838793
Ref: 580817838793
Ref: howto/isolating-extensions isolating-extension-modules17838793
Ref: 580917838793
Ref: howto/isolating-extensions isolating-extensions-howto17838793
Ref: 16617838793
Ref: howto/isolating-extensions translation-repo17838793
Ref: 580a17838793
Node: Who should read this17839533
Ref: howto/isolating-extensions who-should-read-this17839639
Ref: 580b17839639
Node: Background<2>17839877
Ref: howto/isolating-extensions background17840038
Ref: 580c17840038
Node: Enter Per-Module State17841645
Ref: howto/isolating-extensions enter-per-module-state17841749
Ref: 580d17841749
Node: Isolated Module Objects17842916
Ref: howto/isolating-extensions isolated-module-objects17843050
Ref: 580e17843050
Node: Surprising Edge Cases17844087
Ref: howto/isolating-extensions surprising-edge-cases17844190
Ref: 581017844190
Node: Making Modules Safe with Multiple Interpreters17845204
Ref: howto/isolating-extensions making-modules-safe-with-multiple-interpreters17845358
Ref: 581117845358
Node: Managing Global State17845677
Ref: howto/isolating-extensions managing-global-state17845815
Ref: 580f17845815
Node: Managing Per-Module State17846773
Ref: howto/isolating-extensions managing-per-module-state17846969
Ref: 581217846969
Ref: Managing Per-Module State-Footnote-117848645
Node: Opt-Out Limiting to One Module Object per Process17848719
Ref: howto/isolating-extensions isolating-extensions-optout17848928
Ref: 51e817848928
Ref: howto/isolating-extensions opt-out-limiting-to-one-module-object-per-process17848928
Ref: 581317848928
Node: Module State Access from Functions17850290
Ref: howto/isolating-extensions module-state-access-from-functions17850465
Ref: 581417850465
Node: Heap Types<2>17851247
Ref: howto/isolating-extensions heap-types17851399
Ref: 581517851399
Node: Changing Static Types to Heap Types17853077
Ref: howto/isolating-extensions changing-static-types-to-heap-types17853190
Ref: 581617853190
Node: Defining Heap Types17854168
Ref: howto/isolating-extensions defining-heap-types17854317
Ref: 581717854317
Node: Garbage-Collection Protocol17854972
Ref: howto/isolating-extensions garbage-collection-protocol17855118
Ref: 581817855118
Node: tp_traverse in Python 3 8 and lower17856214
Ref: howto/isolating-extensions tp-traverse-in-python-3-8-and-lower17856344
Ref: 581917856344
Node: Delegating tp_traverse17857112
Ref: howto/isolating-extensions delegating-tp-traverse17857270
Ref: 581a17857270
Node: Defining tp_dealloc17858080
Ref: howto/isolating-extensions defining-tp-dealloc17858225
Ref: 581b17858225
Node: Not overriding tp_free17858997
Ref: howto/isolating-extensions not-overriding-tp-free17859141
Ref: 581c17859141
Node: Avoiding PyObject_New17859348
Ref: howto/isolating-extensions avoiding-pyobject-new17859464
Ref: 581d17859464
Node: Module State Access from Classes17860253
Ref: howto/isolating-extensions module-state-access-from-classes17860420
Ref: 581e17860420
Node: Module State Access from Regular Methods17860993
Ref: howto/isolating-extensions module-state-access-from-regular-methods17861190
Ref: 581f17861190
Node: Module State Access from Slot Methods Getters and Setters17863699
Ref: howto/isolating-extensions module-state-access-from-slot-methods-getters-and-setters17863892
Ref: 582017863892
Node: Lifetime of the Module State17865321
Ref: howto/isolating-extensions lifetime-of-the-module-state17865465
Ref: 582117865465
Node: Open Issues17866008
Ref: howto/isolating-extensions open-issues17866105
Ref: 582217866105
Ref: Open Issues-Footnote-117866417
Node: Per-Class Scope17866472
Ref: howto/isolating-extensions per-class-scope17866577
Ref: 582317866577
Node: Lossless Conversion to Heap Types17866870
Ref: howto/isolating-extensions lossless-conversion-to-heap-types17866975
Ref: 582417866975
Node: timer file descriptor HOWTO17867215
Ref: howto/timerfd doc17867375
Ref: 582517867375
Ref: howto/timerfd timer-file-descriptor-howto17867375
Ref: 582617867375
Ref: howto/timerfd timerfd-howto17867375
Ref: 582717867375
Ref: howto/timerfd translation-repo17867375
Ref: 582817867375
Node: Examples<41>17867572
Ref: howto/timerfd examples17867648
Ref: 582917867648
Node: The Python 2 3 Method Resolution Order17876455
Ref: howto/mro doc17876621
Ref: 582a17876621
Ref: howto/mro python-2-3-mro17876621
Ref: 16b117876621
Ref: howto/mro the-python-2-3-method-resolution-order17876621
Ref: 582b17876621
Ref: howto/mro translation-repo17876621
Ref: 582c17876621
Ref: The Python 2 3 Method Resolution Order-Footnote-117878234
Node: The beginning17878281
Ref: howto/mro the-beginning17878408
Ref: 582d17878408
Ref: The beginning-Footnote-117882993
Ref: The beginning-Footnote-217883130
Node: The C3 Method Resolution Order17883242
Ref: howto/mro the-c3-method-resolution-order17883390
Ref: 582e17883390
Node: Examples<42>17885721
Ref: howto/mro examples17885884
Ref: 582f17885884
Node: Bad Method Resolution Orders17891435
Ref: howto/mro bad-method-resolution-orders17891575
Ref: 583017891575
Ref: Bad Method Resolution Orders-Footnote-117897823
Node: The end17898009
Ref: howto/mro the-end17898146
Ref: 583117898146
Node: Resources17901325
Ref: howto/mro resources17901425
Ref: 583217901425
Node: Python support for free threading17901460
Ref: howto/free-threading-python doc17901641
Ref: 583317901641
Ref: howto/free-threading-python freethreading-python-howto17901641
Ref: 25f517901641
Ref: howto/free-threading-python python-support-for-free-threading17901641
Ref: 583417901641
Ref: howto/free-threading-python translation-repo17901641
Ref: 583517901641
Ref: Python support for free threading-Footnote-117902956
Node: Installation<2>17902998
Ref: howto/free-threading-python installation17903124
Ref: 583717903124
Ref: Installation<2>-Footnote-117903710
Node: Identifying free-threaded Python17903774
Ref: howto/free-threading-python identifying-free-threaded-python17903960
Ref: 583817903960
Node: The global interpreter lock in free-threaded Python17904629
Ref: howto/free-threading-python the-global-interpreter-lock-in-free-threaded-python17904813
Ref: 583917904813
Node: Thread safety17905563
Ref: howto/free-threading-python thread-safety17905732
Ref: 583a17905732
Node: Known limitations17906524
Ref: howto/free-threading-python known-limitations17906660
Ref: 583b17906660
Node: Immortalization17906913
Ref: howto/free-threading-python immortalization17907007
Ref: 583c17907007
Node: Frame objects<2>17907534
Ref: howto/free-threading-python frame-objects17907649
Ref: 583d17907649
Node: Iterators<2>17907877
Ref: howto/free-threading-python iterators17908004
Ref: 583e17908004
Node: Single-threaded performance17908198
Ref: howto/free-threading-python single-threaded-performance17908300
Ref: 583f17908300
Node: Behavioral changes17908685
Ref: howto/free-threading-python behavioral-changes17908799
Ref: 584017908799
Node: Context variables17908986
Ref: howto/free-threading-python context-variables17909082
Ref: 584117909082
Node: Warning filters17909501
Ref: howto/free-threading-python warning-filters17909597
Ref: 584217909597
Node: C API Extension Support for Free Threading17910107
Ref: howto/free-threading-extensions doc17910286
Ref: 584317910286
Ref: howto/free-threading-extensions c-api-extension-support-for-free-threading17910286
Ref: 584417910286
Ref: howto/free-threading-extensions freethreading-extensions-howto17910286
Ref: 583617910286
Ref: howto/free-threading-extensions translation-repo17910286
Ref: 584517910286
Node: Identifying the Free-Threaded Build in C17910946
Ref: howto/free-threading-extensions identifying-the-free-threaded-build-in-c17911095
Ref: 584617911095
Node: Module Initialization17911801
Ref: howto/free-threading-extensions module-initialization17911981
Ref: 584717911981
Node: Multi-Phase Initialization17912475
Ref: howto/free-threading-extensions multi-phase-initialization17912595
Ref: 584817912595
Node: Single-Phase Initialization17913268
Ref: howto/free-threading-extensions single-phase-initialization17913388
Ref: 584917913388
Node: General API Guidelines17914228
Ref: howto/free-threading-extensions general-api-guidelines17914387
Ref: 584a17914387
Node: Container Thread Safety17915330
Ref: howto/free-threading-extensions container-thread-safety17915412
Ref: 584c17915412
Node: PyDict_Next17915747
Ref: howto/free-threading-extensions id117915818
Ref: 584d17915818
Ref: howto/free-threading-extensions pydict-next17915818
Ref: 584e17915818
Node: Borrowed References17916306
Ref: howto/free-threading-extensions borrowed-references17916466
Ref: 584f17916466
Ref: howto/free-threading-extensions id217916521
Ref: 584b17916521
Ref: Borrowed References-Footnote-117919459
Node: Memory Allocation APIs17919511
Ref: howto/free-threading-extensions free-threaded-memory-allocation17919674
Ref: 558f17919674
Ref: howto/free-threading-extensions memory-allocation-apis17919674
Ref: 585017919674
Node: Thread State and GIL APIs17920415
Ref: howto/free-threading-extensions thread-state-and-gil-apis17920594
Ref: 585117920594
Node: Protecting Internal Extension State17921560
Ref: howto/free-threading-extensions protecting-internal-extension-state17921734
Ref: 585217921734
Ref: Protecting Internal Extension State-Footnote-117922490
Node: Critical Sections17922556
Ref: howto/free-threading-extensions critical-sections17922752
Ref: 585317922752
Ref: howto/free-threading-extensions id317922803
Ref: 585417922803
Node: What Are Critical Sections?17923334
Ref: howto/free-threading-extensions what-are-critical-sections17923447
Ref: 585517923447
Node: Using Critical Sections17923924
Ref: howto/free-threading-extensions using-critical-sections17924072
Ref: 585617924072
Node: How Critical Sections Work17925322
Ref: howto/free-threading-extensions how-critical-sections-work17925461
Ref: 585717925461
Node: Deadlock Avoidance17926372
Ref: howto/free-threading-extensions deadlock-avoidance17926512
Ref: 585817926512
Node: Important Considerations17927674
Ref: howto/free-threading-extensions important-considerations17927779
Ref: 585917927779
Node: Building Extensions for the Free-Threaded Build17929732
Ref: howto/free-threading-extensions building-extensions-for-the-free-threaded-build17929884
Ref: 585a17929884
Ref: Building Extensions for the Free-Threaded Build-Footnote-117930612
Ref: Building Extensions for the Free-Threaded Build-Footnote-217930654
Ref: Building Extensions for the Free-Threaded Build-Footnote-317930699
Node: Limited C API and Stable ABI17930762
Ref: howto/free-threading-extensions limited-c-api-and-stable-abi17930894
Ref: 585b17930894
Ref: Limited C API and Stable ABI-Footnote-117931591
Node: Windows<84>17931652
Ref: howto/free-threading-extensions windows17931784
Ref: 585c17931784
Ref: Windows<84>-Footnote-117932146
Node: Remote debugging attachment protocol17932199
Ref: howto/remote_debugging doc17932368
Ref: 585d17932368
Ref: howto/remote_debugging remote-debugging17932368
Ref: 490f17932368
Ref: howto/remote_debugging remote-debugging-attachment-protocol17932368
Ref: 585e17932368
Ref: howto/remote_debugging translation-repo17932368
Ref: 585f17932368
Node: Disabling remote debugging17932686
Ref: howto/remote_debugging disabling-remote-debugging17932785
Ref: 586017932785
Node: Permission requirements17933194
Ref: howto/remote_debugging id117933353
Ref: 586117933353
Ref: howto/remote_debugging permission-requirements17933353
Ref: 586217933353
Node: Locating the PyRuntime structure17937022
Ref: howto/remote_debugging locating-the-pyruntime-structure17937169
Ref: 586317937169
Ref: Locating the PyRuntime structure-Footnote-117947242
Ref: Locating the PyRuntime structure-Footnote-217947311
Ref: Locating the PyRuntime structure-Footnote-317947418
Ref: Locating the PyRuntime structure-Footnote-417947514
Node: Reading _Py_DebugOffsets17947609
Ref: howto/remote_debugging reading-py-debugoffsets17947774
Ref: 586417947774
Node: Locating the interpreter and thread state17951582
Ref: howto/remote_debugging locating-the-interpreter-and-thread-state17951742
Ref: 586517951742
Node: Writing control information17956336
Ref: howto/remote_debugging writing-control-information17956479
Ref: 586617956479
Node: Summary17960257
Ref: howto/remote_debugging summary17960350
Ref: 586717960350
Node: Python Frequently Asked Questions17962302
Ref: faq/index doc17962418
Ref: 586817962418
Ref: faq/index faq-index17962418
Ref: 20de17962418
Ref: faq/index python-frequently-asked-questions17962418
Ref: 586917962418
Ref: faq/index translation-repo17962418
Ref: 586a17962418
Node: General Python FAQ17962740
Ref: faq/general doc17962852
Ref: 586b17962852
Ref: faq/general general-python-faq17962852
Ref: 586c17962852
Node: General Information17962964
Ref: faq/general general-information17963071
Ref: 586d17963071
Node: What is Python?17964058
Ref: faq/general what-is-python17964177
Ref: 586e17964177
Ref: What is Python?-Footnote-117965124
Node: What is the Python Software Foundation?17965176
Ref: faq/general what-is-the-python-software-foundation17965358
Ref: 586f17965358
Ref: What is the Python Software Foundation?-Footnote-117965962
Node: Are there copyright restrictions on the use of Python?17966008
Ref: faq/general are-there-copyright-restrictions-on-the-use-of-python17966217
Ref: 587017966217
Ref: Are there copyright restrictions on the use of Python?-Footnote-117967079
Ref: Are there copyright restrictions on the use of Python?-Footnote-217967126
Node: Why was Python created in the first place?17967173
Ref: faq/general why-was-python-created-in-the-first-place17967367
Ref: 587117967367
Node: What is Python good for?17969699
Ref: faq/general what-is-python-good-for17969889
Ref: 587217969889
Ref: What is Python good for?-Footnote-117970740
Node: How does the Python version numbering scheme work?17970765
Ref: faq/general faq-version-numbering-scheme17970957
Ref: 587317970957
Ref: faq/general how-does-the-python-version-numbering-scheme-work17970957
Ref: 587417970957
Ref: How does the Python version numbering scheme work?-Footnote-117973015
Ref: How does the Python version numbering scheme work?-Footnote-217973089
Node: How do I obtain a copy of the Python source?17973131
Ref: faq/general how-do-i-obtain-a-copy-of-the-python-source17973336
Ref: 587517973336
Ref: How do I obtain a copy of the Python source?-Footnote-117974118
Node: How do I get documentation on Python?17974161
Ref: faq/general how-do-i-get-documentation-on-python17974374
Ref: 587617974374
Ref: How do I get documentation on Python?-Footnote-117974938
Node: I’ve never programmed before Is there a Python tutorial?17974974
Ref: faq/general i-ve-never-programmed-before-is-there-a-python-tutorial17975198
Ref: 587717975198
Ref: I’ve never programmed before Is there a Python tutorial?-Footnote-117975608
Node: Is there a newsgroup or mailing list devoted to Python?17975660
Ref: faq/general is-there-a-newsgroup-or-mailing-list-devoted-to-python17975890
Ref: 587817975890
Ref: Is there a newsgroup or mailing list devoted to Python?-Footnote-117976769
Ref: Is there a newsgroup or mailing list devoted to Python?-Footnote-217976830
Node: How do I get a beta test version of Python?17976911
Ref: faq/general how-do-i-get-a-beta-test-version-of-python17977134
Ref: 587917977134
Ref: How do I get a beta test version of Python?-Footnote-117977671
Node: How do I submit bug reports and patches for Python?17977708
Ref: faq/general how-do-i-submit-bug-reports-and-patches-for-python17977943
Ref: 587a17977943
Ref: How do I submit bug reports and patches for Python?-Footnote-117978304
Node: Are there any published articles about Python that I can reference?17978341
Ref: faq/general are-there-any-published-articles-about-python-that-i-can-reference17978563
Ref: 587b17978563
Ref: Are there any published articles about Python that I can reference?-Footnote-117979113
Node: Are there any books on Python?17979149
Ref: faq/general are-there-any-books-on-python17979365
Ref: 587c17979365
Node: Where in the world is www python org located?17979736
Ref: faq/general where-in-the-world-is-www-python-org-located17979909
Ref: 587d17979909
Ref: Where in the world is www python org located?-Footnote-117980195
Node: Why is it called Python?17980224
Ref: faq/general why-is-it-called-python17980420
Ref: 587e17980420
Ref: Why is it called Python?-Footnote-117980824
Node: Do I have to like «Monty Python’s Flying Circus»?17980875
Ref: faq/general do-i-have-to-like-monty-python-s-flying-circus17981017
Ref: 587f17981017
Node: Python in the real world17981165
Ref: faq/general python-in-the-real-world17981272
Ref: 588017981272
Node: How stable is Python?17981652
Ref: faq/general how-stable-is-python17981776
Ref: 588117981776
Ref: How stable is Python?-Footnote-117982702
Ref: How stable is Python?-Footnote-217982744
Ref: How stable is Python?-Footnote-317982786
Node: How many people are using Python?17982828
Ref: faq/general how-many-people-are-using-python17983011
Ref: 588217983011
Node: Have any significant projects been done in Python?17983517
Ref: faq/general have-any-significant-projects-been-done-in-python17983739
Ref: 588317983739
Ref: Have any significant projects been done in Python?-Footnote-117984453
Ref: Have any significant projects been done in Python?-Footnote-217984505
Ref: Have any significant projects been done in Python?-Footnote-317984534
Ref: Have any significant projects been done in Python?-Footnote-417984563
Node: What new developments are expected for Python in the future?17984594
Ref: faq/general what-new-developments-are-expected-for-python-in-the-future17984842
Ref: 588417984842
Ref: What new developments are expected for Python in the future?-Footnote-117985420
Node: Is it reasonable to propose incompatible changes to Python?17985490
Ref: faq/general is-it-reasonable-to-propose-incompatible-changes-to-python17985740
Ref: 588517985740
Ref: Is it reasonable to propose incompatible changes to Python?-Footnote-117986544
Node: Is Python a good language for beginning programmers?17986586
Ref: faq/general is-python-a-good-language-for-beginning-programmers17986767
Ref: 588617986767
Ref: Is Python a good language for beginning programmers?-Footnote-117990588
Ref: Is Python a good language for beginning programmers?-Footnote-217990639
Node: Programming FAQ17990701
Ref: faq/programming doc17990844
Ref: 588717990844
Ref: faq/programming programming-faq17990844
Ref: 588817990844
Ref: faq/programming translation-repo17990844
Ref: 588917990844
Node: General Questions17991079
Ref: faq/programming general-questions17991170
Ref: 588a17991170
Node: Is there a source code level debugger with breakpoints single-stepping etc ?17991590
Ref: faq/programming is-there-a-source-code-level-debugger-with-breakpoints-single-stepping-etc17991790
Ref: 588b17991790
Ref: Is there a source code level debugger with breakpoints single-stepping etc ?-Footnote-117993234
Ref: Is there a source code level debugger with breakpoints single-stepping etc ?-Footnote-217993306
Ref: Is there a source code level debugger with breakpoints single-stepping etc ?-Footnote-317993350
Ref: Is there a source code level debugger with breakpoints single-stepping etc ?-Footnote-417993403
Ref: Is there a source code level debugger with breakpoints single-stepping etc ?-Footnote-517993449
Ref: Is there a source code level debugger with breakpoints single-stepping etc ?-Footnote-617993498
Ref: Is there a source code level debugger with breakpoints single-stepping etc ?-Footnote-717993537
Ref: Is there a source code level debugger with breakpoints single-stepping etc ?-Footnote-817993567
Ref: Is there a source code level debugger with breakpoints single-stepping etc ?-Footnote-917993624
Node: Are there tools to help find bugs or perform static analysis?17993667
Ref: faq/programming are-there-tools-to-help-find-bugs-or-perform-static-analysis17993935
Ref: 588c17993935
Ref: Are there tools to help find bugs or perform static analysis?-Footnote-117994309
Ref: Are there tools to help find bugs or perform static analysis?-Footnote-217994363
Ref: Are there tools to help find bugs or perform static analysis?-Footnote-317994405
Ref: Are there tools to help find bugs or perform static analysis?-Footnote-417994436
Ref: Are there tools to help find bugs or perform static analysis?-Footnote-517994468
Node: How can I create a stand-alone binary from a Python script?17994509
Ref: faq/programming faq-create-standalone-binary17994765
Ref: 588d17994765
Ref: faq/programming how-can-i-create-a-stand-alone-binary-from-a-python-script17994765
Ref: 588e17994765
Ref: How can I create a stand-alone binary from a Python script?-Footnote-117996481
Ref: How can I create a stand-alone binary from a Python script?-Footnote-217996546
Ref: How can I create a stand-alone binary from a Python script?-Footnote-317996574
Ref: How can I create a stand-alone binary from a Python script?-Footnote-417996607
Ref: How can I create a stand-alone binary from a Python script?-Footnote-517996660
Ref: How can I create a stand-alone binary from a Python script?-Footnote-617996712
Ref: How can I create a stand-alone binary from a Python script?-Footnote-717996761
Node: Are there coding standards or a style guide for Python programs?17996793
Ref: faq/programming are-there-coding-standards-or-a-style-guide-for-python-programs17996979
Ref: 588f17996979
Ref: Are there coding standards or a style guide for Python programs?-Footnote-117997253
Node: Core Language17997295
Ref: faq/programming core-language17997414
Ref: 589017997414
Node: Why am I getting an UnboundLocalError when the variable has a value?17998778
Ref: faq/programming faq-unboundlocalerror17998965
Ref: 240f17998965
Ref: faq/programming why-am-i-getting-an-unboundlocalerror-when-the-variable-has-a-value17998965
Ref: 589117998965
Node: What are the rules for local and global variables in Python?18000871
Ref: faq/programming what-are-the-rules-for-local-and-global-variables-in-python18001149
Ref: 589218001149
Node: Why do lambdas defined in a loop with different values all return the same result?18002049
Ref: faq/programming why-do-lambdas-defined-in-a-loop-with-different-values-all-return-the-same-result18002306
Ref: 589318002306
Node: How do I share global variables across modules?18004215
Ref: faq/programming how-do-i-share-global-variables-across-modules18004473
Ref: 589418004473
Node: What are the «best practices» for using import in a module?18005276
Ref: faq/programming what-are-the-best-practices-for-using-import-in-a-module18005498
Ref: 589518005498
Node: Why are default values shared between objects?18008289
Ref: faq/programming why-are-default-values-shared-between-objects18008539
Ref: 589618008539
Node: How can I pass optional or keyword parameters from one function to another?18010925
Ref: faq/programming how-can-i-pass-optional-or-keyword-parameters-from-one-function-to-another18011170
Ref: 589718011170
Node: What is the difference between arguments and parameters?18011757
Ref: faq/programming faq-argument-vs-parameter18012011
Ref: 589818012011
Ref: faq/programming what-is-the-difference-between-arguments-and-parameters18012011
Ref: 589918012011
Node: Why did changing list “y” also change list “x”?18012712
Ref: faq/programming why-did-changing-list-y-also-change-list-x18012959
Ref: 589a18012959
Node: How do I write a function with output parameters call by reference ?18016374
Ref: faq/programming how-do-i-write-a-function-with-output-parameters-call-by-reference18016615
Ref: 589b18016615
Node: How do you make a higher order function in Python?18019020
Ref: faq/programming how-do-you-make-a-higher-order-function-in-python18019240
Ref: 589c18019240
Node: How do I copy an object in Python?18020814
Ref: faq/programming how-do-i-copy-an-object-in-python18021020
Ref: 589d18021020
Node: How can I find the methods or attributes of an object?18021427
Ref: faq/programming how-can-i-find-the-methods-or-attributes-of-an-object18021630
Ref: 589e18021630
Node: How can my code discover the name of an object?18021956
Ref: faq/programming how-can-my-code-discover-the-name-of-an-object18022176
Ref: 589f18022176
Node: What’s up with the comma operator’s precedence?18023819
Ref: faq/programming what-s-up-with-the-comma-operator-s-precedence18024041
Ref: 58a018024041
Node: Is there an equivalent of C’s «? » ternary operator?18024599
Ref: faq/programming is-there-an-equivalent-of-c-s-ternary-operator18024830
Ref: 58a118024830
Node: Is it possible to write obfuscated one-liners in Python?18025423
Ref: faq/programming is-it-possible-to-write-obfuscated-one-liners-in-python18025666
Ref: 58a218025666
Node: What does the slash / in the parameter list of a function mean?18027166
Ref: faq/programming faq-positional-only-arguments18027344
Ref: 25b218027344
Ref: faq/programming what-does-the-slash-in-the-parameter-list-of-a-function-mean18027344
Ref: 58a318027344
Node: Numbers and strings18028444
Ref: faq/programming numbers-and-strings18028560
Ref: 58a418028560
Node: How do I specify hexadecimal and octal integers?18029345
Ref: faq/programming how-do-i-specify-hexadecimal-and-octal-integers18029487
Ref: 58a518029487
Node: Why does -22 // 10 return -3?18030128
Ref: faq/programming why-does-22-10-return-318030337
Ref: 58a618030337
Node: How do I get int literal attribute instead of SyntaxError?18031098
Ref: faq/programming how-do-i-get-int-literal-attribute-instead-of-syntaxerror18031297
Ref: 58a718031297
Node: How do I convert a string to a number?18031883
Ref: faq/programming how-do-i-convert-a-string-to-a-number18032091
Ref: 58a818032091
Node: How do I convert a number to a string?18033424
Ref: faq/programming how-do-i-convert-a-number-to-a-string18033608
Ref: 58a918033608
Node: How do I modify a string in place?18034154
Ref: faq/programming how-do-i-modify-a-string-in-place18034347
Ref: 58aa18034347
Node: How do I use strings to call functions/methods?18035204
Ref: faq/programming how-do-i-use-strings-to-call-functions-methods18035444
Ref: 58ab18035444
Node: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?18036772
Ref: faq/programming is-there-an-equivalent-to-perl-s-chomp-for-removing-trailing-newlines-from-strings18037016
Ref: 58ac18037016
Node: Is there a scanf or sscanf equivalent?18037783
Ref: faq/programming is-there-a-scanf-or-sscanf-equivalent18038042
Ref: 58ad18038042
Node: What does UnicodeDecodeError or UnicodeEncodeError error mean?18038706
Ref: faq/programming what-does-unicodedecodeerror-or-unicodeencodeerror-error-mean18038937
Ref: 58ae18038937
Node: Can I end a raw string with an odd number of backslashes?18039136
Ref: faq/programming can-i-end-a-raw-string-with-an-odd-number-of-backslashes18039320
Ref: 58af18039320
Ref: faq/programming faq-programming-raw-string-backslash18039320
Ref: 1fc718039320
Node: Performance<4>18040600
Ref: faq/programming performance18040725
Ref: 58b018040725
Node: My program is too slow How do I speed it up?18040942
Ref: faq/programming my-program-is-too-slow-how-do-i-speed-it-up18041114
Ref: 58b118041114
Ref: My program is too slow How do I speed it up?-Footnote-118044002
Ref: My program is too slow How do I speed it up?-Footnote-218044029
Node: What is the most efficient way to concatenate many strings together?18044094
Ref: faq/programming efficient-string-concatenation18044266
Ref: 58b218044266
Ref: faq/programming what-is-the-most-efficient-way-to-concatenate-many-strings-together18044266
Ref: 58b318044266
Node: Sequences Tuples/Lists18045237
Ref: faq/programming sequences-tuples-lists18045350
Ref: 58b418045350
Node: How do I convert between tuples and lists?18046107
Ref: faq/programming how-do-i-convert-between-tuples-and-lists18046243
Ref: 58b518046243
Node: What’s a negative index?18047090
Ref: faq/programming what-s-a-negative-index18047285
Ref: 58b618047285
Node: How do I iterate over a sequence in reverse order?18047865
Ref: faq/programming how-do-i-iterate-over-a-sequence-in-reverse-order18048059
Ref: 58b718048059
Node: How do you remove duplicates from a list?18048408
Ref: faq/programming how-do-you-remove-duplicates-from-a-list18048621
Ref: 58b818048621
Node: How do you remove multiple items from a list?18049448
Ref: faq/programming how-do-you-remove-multiple-items-from-a-list18049646
Ref: 58b918049646
Node: How do you make an array in Python?18050195
Ref: faq/programming how-do-you-make-an-array-in-python18050392
Ref: 58ba18050392
Ref: How do you make an array in Python?-Footnote-118051426
Node: How do I create a multidimensional list?18051453
Ref: faq/programming faq-multidimensional-list18051666
Ref: 25e718051666
Ref: faq/programming how-do-i-create-a-multidimensional-list18051666
Ref: 58bb18051666
Ref: How do I create a multidimensional list?-Footnote-118052888
Node: How do I apply a method or function to a sequence of objects?18052915
Ref: faq/programming how-do-i-apply-a-method-or-function-to-a-sequence-of-objects18053172
Ref: 58bc18053172
Node: Why does a_tuple[i] += [“item”] raise an exception when the addition works?18053751
Ref: faq/programming faq-augmented-assignment-tuple-error18054045
Ref: 23e518054045
Ref: faq/programming why-does-a-tuple-i-item-raise-an-exception-when-the-addition-works18054045
Ref: 58bd18054045
Node: I want to do a complicated sort can you do a Schwartzian Transform in Python?18057297
Ref: faq/programming i-want-to-do-a-complicated-sort-can-you-do-a-schwartzian-transform-in-python18057582
Ref: 58be18057582
Node: How can I sort one list by values from another list?18058065
Ref: faq/programming how-can-i-sort-one-list-by-values-from-another-list18058262
Ref: 58bf18058262
Node: Objects18058857
Ref: faq/programming objects18058966
Ref: 58c018058966
Node: What is a class?18060143
Ref: faq/programming what-is-a-class18060229
Ref: 58c118060229
Node: What is a method?18060955
Ref: faq/programming what-is-a-method18061063
Ref: 58c218061063
Node: What is self?18061372
Ref: faq/programming what-is-self18061547
Ref: 58c318061547
Node: How do I check if an object is an instance of a given class or of a subclass of it?18061989
Ref: faq/programming how-do-i-check-if-an-object-is-an-instance-of-a-given-class-or-of-a-subclass-of-it18062166
Ref: 58c518062166
Node: What is delegation?18064467
Ref: faq/programming what-is-delegation18064715
Ref: 58c618064715
Node: How do I call a method defined in a base class from a derived class that extends it?18066822
Ref: faq/programming how-do-i-call-a-method-defined-in-a-base-class-from-a-derived-class-that-extends-it18067057
Ref: 58c718067057
Node: How can I organize my code to make it easier to change the base class?18067679
Ref: faq/programming how-can-i-organize-my-code-to-make-it-easier-to-change-the-base-class18067954
Ref: 58c818067954
Node: How do I create static class data and static class methods?18068504
Ref: faq/programming how-do-i-create-static-class-data-and-static-class-methods18068748
Ref: 58c918068748
Node: How can I overload constructors or methods in Python?18070315
Ref: faq/programming how-can-i-overload-constructors-or-methods-in-python18070554
Ref: 58ca18070554
Node: I try to use __spam and I get an error about _SomeClassName__spam18071461
Ref: faq/programming i-try-to-use-spam-and-i-get-an-error-about-someclassname-spam18071711
Ref: 58cb18071711
Node: My class defines __del__ but it is not called when I delete the object18072918
Ref: faq/programming my-class-defines-del-but-it-is-not-called-when-i-delete-the-object18073169
Ref: 58cc18073169
Node: How do I get a list of all instances of a given class?18075120
Ref: faq/programming how-do-i-get-a-list-of-all-instances-of-a-given-class18075356
Ref: 58cd18075356
Node: Why does the result of id appear to be not unique?18075697
Ref: faq/programming why-does-the-result-of-id-appear-to-be-not-unique18075918
Ref: 58ce18075918
Node: When can I rely on identity tests with the is operator?18076811
Ref: faq/programming when-can-i-rely-on-identity-tests-with-the-is-operator18077050
Ref: 58cf18077050
Ref: When can I rely on identity tests with the is operator?-Footnote-118080393
Node: How can a subclass control what data is stored in an immutable instance?18080435
Ref: faq/programming how-can-a-subclass-control-what-data-is-stored-in-an-immutable-instance18080652
Ref: 58d018080652
Node: How do I cache method calls?18082128
Ref: faq/programming faq-cache-method-calls18082281
Ref: 2b9518082281
Ref: faq/programming how-do-i-cache-method-calls18082281
Ref: 58d118082281
Node: Modules<3>18085276
Ref: faq/programming modules18085354
Ref: 58d218085354
Node: How do I create a pyc file?18085894
Ref: faq/programming how-do-i-create-a-pyc-file18086015
Ref: 58d318086015
Ref: How do I create a pyc file?-Footnote-118088597
Node: How do I find the current module name?18088639
Ref: faq/programming how-do-i-find-the-current-module-name18088824
Ref: 58d418088824
Node: How can I have modules that mutually import each other?18089382
Ref: faq/programming how-can-i-have-modules-that-mutually-import-each-other18089604
Ref: 58d518089604
Node: __import__ “x y z” returns <module “x”>; how do I get z?18091653
Ref: faq/programming import-x-y-z-returns-module-x-how-do-i-get-z18091933
Ref: 58d618091933
Node: When I edit an imported module and reimport it the changes don’t show up Why does this happen?18092223
Ref: faq/programming when-i-edit-an-imported-module-and-reimport-it-the-changes-don-t-show-up-why-does-this-happen18092439
Ref: 58d718092439
Node: Design and History FAQ18093884
Ref: faq/design doc18094034
Ref: 58d818094034
Ref: faq/design design-and-history-faq18094034
Ref: 58d918094034
Ref: faq/design translation-repo18094034
Ref: 58da18094034
Node: Why does Python use indentation for grouping of statements?18096131
Ref: faq/design why-does-python-use-indentation-for-grouping-of-statements18096325
Ref: 58db18096325
Node: Why am I getting strange results with simple arithmetic operations?18098045
Ref: faq/design why-am-i-getting-strange-results-with-simple-arithmetic-operations18098298
Ref: 58dc18098298
Node: Why are floating-point calculations so inaccurate?18098473
Ref: faq/design why-are-floating-point-calculations-so-inaccurate18098700
Ref: 58dd18098700
Node: Why are Python strings immutable?18100239
Ref: faq/design why-are-python-strings-immutable18100470
Ref: 58de18100470
Node: Why must “self” be used explicitly in method definitions and calls?18101069
Ref: faq/design why-must-self-be-used-explicitly-in-method-definitions-and-calls18101299
Ref: 58df18101299
Ref: faq/design why-self18101299
Ref: 58c418101299
Node: Why can’t I use an assignment in an expression?18103789
Ref: faq/design id118104090
Ref: 58e018104090
Ref: faq/design why-can-t-i-use-an-assignment-in-an-expression18104090
Ref: 202218104090
Ref: Why can’t I use an assignment in an expression?-Footnote-118104462
Node: Why does Python use methods for some functionality e g list index but functions for other e g len list ?18104504
Ref: faq/design why-does-python-use-methods-for-some-functionality-e-g-list-index-but-functions-for-other-e-g-len-list18104796
Ref: 58e118104796
Node: Why is join a string method instead of a list or tuple method?18106134
Ref: faq/design why-is-join-a-string-method-instead-of-a-list-or-tuple-method18106401
Ref: 58e218106401
Node: How fast are exceptions?18108209
Ref: faq/design how-fast-are-exceptions18108427
Ref: 58e318108427
Node: Why isn’t there a switch or case statement in Python?18109265
Ref: faq/design why-isn-t-there-a-switch-or-case-statement-in-python18109527
Ref: 58e418109527
Node: Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?18111018
Ref: faq/design can-t-you-emulate-threads-in-the-interpreter-instead-of-relying-on-an-os-specific-thread-implementation18111306
Ref: 58e518111306
Ref: Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?-Footnote-118111953
Node: Why can’t lambda expressions contain statements?18112009
Ref: faq/design why-can-t-lambda-expressions-contain-statements18112306
Ref: 58e618112306
Node: Can Python be compiled to machine code C or some other language?18113171
Ref: faq/design can-python-be-compiled-to-machine-code-c-or-some-other-language18113392
Ref: 58e718113392
Ref: Can Python be compiled to machine code C or some other language?-Footnote-118113780
Ref: Can Python be compiled to machine code C or some other language?-Footnote-218113808
Node: How does Python manage memory?18113836
Ref: faq/design how-does-python-manage-memory18114078
Ref: 58e818114078
Ref: How does Python manage memory?-Footnote-118115750
Ref: How does Python manage memory?-Footnote-218115781
Node: Why doesn’t CPython use a more traditional garbage collection scheme?18115806
Ref: faq/design why-doesn-t-cpython-use-a-more-traditional-garbage-collection-scheme18116032
Ref: 58e918116032
Node: Why isn’t all memory freed when CPython exits?18116983
Ref: faq/design why-isn-t-all-memory-freed-when-cpython-exits18117228
Ref: 58ea18117228
Node: Why are there separate tuple and list data types?18117923
Ref: faq/design why-are-there-separate-tuple-and-list-data-types18118134
Ref: 58eb18118134
Node: How are lists implemented in CPython?18119387
Ref: faq/design how-are-lists-implemented-in-cpython18119594
Ref: 58ec18119594
Node: How are dictionaries implemented in CPython?18120335
Ref: faq/design how-are-dictionaries-implemented-in-cpython18120531
Ref: 58ed18120531
Node: Why must dictionary keys be immutable?18121500
Ref: faq/design why-must-dictionary-keys-be-immutable18121706
Ref: 58ee18121706
Node: Why doesn’t list sort return the sorted list?18125914
Ref: faq/design why-doesn-t-list-sort-return-the-sorted-list18126135
Ref: 58ef18126135
Node: How do you specify and enforce an interface spec in Python?18126979
Ref: faq/design how-do-you-specify-and-enforce-an-interface-spec-in-python18127183
Ref: 58f018127183
Node: Why is there no goto?18129519
Ref: faq/design why-is-there-no-goto18129731
Ref: 58f118129731
Node: Why can’t raw strings r-strings end with a backslash?18130870
Ref: faq/design why-can-t-raw-strings-r-strings-end-with-a-backslash18131096
Ref: 58f218131096
Node: Why doesn’t Python have a «with» statement for attribute assignments?18132197
Ref: faq/design why-doesn-t-python-have-a-with-statement-for-attribute-assignments18132452
Ref: 58f318132452
Node: Why don’t generators support the with statement?18134915
Ref: faq/design why-don-t-generators-support-the-with-statement18135177
Ref: 58f418135177
Node: Why are colons required for the if/while/def/class statements?18135595
Ref: faq/design why-are-colons-required-for-the-if-while-def-class-statements18135844
Ref: 58f518135844
Node: Why does Python allow commas at the end of lists and tuples?18136589
Ref: faq/design why-does-python-allow-commas-at-the-end-of-lists-and-tuples18136779
Ref: 58f618136779
Node: Library and Extension FAQ18137874
Ref: faq/library doc18138032
Ref: 58f718138032
Ref: faq/library library-and-extension-faq18138032
Ref: 58f818138032
Ref: faq/library translation-repo18138032
Ref: 58f918138032
Node: General Library Questions18138261
Ref: faq/library general-library-questions18138369
Ref: 58fa18138369
Node: How do I find a module or application to perform task X?18138881
Ref: faq/library how-do-i-find-a-module-or-application-to-perform-task-x18139064
Ref: 58fb18139064
Ref: How do I find a module or application to perform task X?-Footnote-118139649
Ref: How do I find a module or application to perform task X?-Footnote-218139674
Node: Where is the math py socket py regex py etc source file?18139705
Ref: faq/library where-is-the-math-py-socket-py-regex-py-etc-source-file18139946
Ref: 58fc18139946
Node: How do I make a Python script executable on Unix?18140730
Ref: faq/library how-do-i-make-a-python-script-executable-on-unix18140960
Ref: 58fd18140960
Node: Is there a curses/termcap package for Python?18142437
Ref: faq/library is-there-a-curses-termcap-package-for-python18142660
Ref: 58fe18142660
Ref: Is there a curses/termcap package for Python?-Footnote-118143455
Node: Is there an equivalent to C’s onexit in Python?18143515
Ref: faq/library is-there-an-equivalent-to-c-s-onexit-in-python18143725
Ref: 58ff18143725
Node: Why don’t my signal handlers work?18143945
Ref: faq/library why-don-t-my-signal-handlers-work18144101
Ref: 590018144101
Node: Common tasks18144426
Ref: faq/library common-tasks18144550
Ref: 590118144550
Node: How do I test a Python program or component?18144748
Ref: faq/library how-do-i-test-a-python-program-or-component18144897
Ref: 590218144897
Node: How do I create documentation from doc strings?18146840
Ref: faq/library how-do-i-create-documentation-from-doc-strings18147039
Ref: 590318147039
Ref: How do I create documentation from doc strings?-Footnote-118147415
Ref: How do I create documentation from doc strings?-Footnote-218147455
Node: How do I get a single keypress at a time?18147490
Ref: faq/library how-do-i-get-a-single-keypress-at-a-time18147636
Ref: 590418147636
Node: Threads18147882
Ref: faq/library threads18147997
Ref: 590518147997
Node: How do I program using threads?18148325
Ref: faq/library how-do-i-program-using-threads18148444
Ref: 590618148444
Node: None of my threads seem to run why?18148754
Ref: faq/library none-of-my-threads-seem-to-run-why18148939
Ref: 590718148939
Node: How do I parcel out work among a bunch of worker threads?18150488
Ref: faq/library how-do-i-parcel-out-work-among-a-bunch-of-worker-threads18150694
Ref: 590818150694
Node: What kinds of global value mutation are thread-safe?18153294
Ref: faq/library what-kinds-of-global-value-mutation-are-thread-safe18153515
Ref: 590918153515
Node: Can’t we get rid of the Global Interpreter Lock?18155020
Ref: faq/library can-t-we-get-rid-of-the-global-interpreter-lock18155175
Ref: 590a18155175
Ref: Can’t we get rid of the Global Interpreter Lock?-Footnote-118158188
Ref: Can’t we get rid of the Global Interpreter Lock?-Footnote-218158230
Ref: Can’t we get rid of the Global Interpreter Lock?-Footnote-318158273
Node: Input and Output18158333
Ref: faq/library input-and-output18158464
Ref: 590b18158464
Node: How do I delete a file? And other file questions…18159099
Ref: faq/library how-do-i-delete-a-file-and-other-file-questions18159233
Ref: 590c18159233
Node: How do I copy a file?18160484
Ref: faq/library how-do-i-copy-a-file18160662
Ref: 590d18160662
Ref: How do I copy a file?-Footnote-118161137
Ref: How do I copy a file?-Footnote-218161208
Node: How do I read or write binary data?18161260
Ref: faq/library how-do-i-read-or-write-binary-data18161455
Ref: 590e18161455
Node: I can’t seem to use os read on a pipe created with os popen ; why?18162648
Ref: faq/library i-can-t-seem-to-use-os-read-on-a-pipe-created-with-os-popen-why18162860
Ref: 590f18162860
Node: How do I access the serial RS232 port?18163381
Ref: faq/library how-do-i-access-the-serial-rs232-port18163620
Ref: 591018163620
Ref: How do I access the serial RS232 port?-Footnote-118163945
Node: Why doesn’t closing sys stdout stdin stderr really close it?18163988
Ref: faq/library why-doesn-t-closing-sys-stdout-stdin-stderr-really-close-it18164150
Ref: 591118164150
Node: Network/Internet Programming18165378
Ref: faq/library network-internet-programming18165511
Ref: 591218165511
Node: What WWW tools are there for Python?18165863
Ref: faq/library what-www-tools-are-there-for-python18166027
Ref: 591318166027
Node: What module should I use to help with generating HTML?18166470
Ref: faq/library what-module-should-i-use-to-help-with-generating-html18166683
Ref: 591418166683
Ref: What module should I use to help with generating HTML?-Footnote-118166928
Node: How do I send mail from a Python script?18166980
Ref: faq/library how-do-i-send-mail-from-a-python-script18167215
Ref: 591518167215
Node: How do I avoid blocking in the connect method of a socket?18168556
Ref: faq/library how-do-i-avoid-blocking-in-the-connect-method-of-a-socket18168728
Ref: 591618168728
Ref: How do I avoid blocking in the connect method of a socket?-Footnote-118170067
Node: Databases18170096
Ref: faq/library databases18170237
Ref: 591718170237
Node: Are there any interfaces to database packages in Python?18170398
Ref: faq/library are-there-any-interfaces-to-database-packages-in-python18170559
Ref: 591818170559
Ref: Are there any interfaces to database packages in Python?-Footnote-118171065
Node: How do you implement persistent objects in Python?18171122
Ref: faq/library how-do-you-implement-persistent-objects-in-python18171283
Ref: 591918171283
Node: Mathematics and Numerics18171684
Ref: faq/library mathematics-and-numerics18171788
Ref: 591a18171788
Node: How do I generate random numbers in Python?18171911
Ref: faq/library how-do-i-generate-random-numbers-in-python18172015
Ref: 591b18172015
Node: Extending/Embedding FAQ18172968
Ref: faq/extending doc18173125
Ref: 591c18173125
Ref: faq/extending extending-embedding-faq18173125
Ref: 591d18173125
Ref: faq/extending translation-repo18173125
Ref: 591e18173125
Node: Can I create my own functions in C?18174609
Ref: faq/extending can-i-create-my-own-functions-in-c18174750
Ref: 591f18174750
Node: Can I create my own functions in C++?18175110
Ref: faq/extending id118175306
Ref: 592018175306
Node: Writing C is hard; are there any alternatives?18175693
Ref: faq/extending c-wrapper-software18175907
Ref: 592118175907
Ref: faq/extending writing-c-is-hard-are-there-any-alternatives18175907
Ref: 592218175907
Node: How can I execute arbitrary Python statements from C?18176269
Ref: faq/extending how-can-i-execute-arbitrary-python-statements-from-c18176503
Ref: 592318176503
Node: How can I evaluate an arbitrary Python expression from C?18177049
Ref: faq/extending how-can-i-evaluate-an-arbitrary-python-expression-from-c18177284
Ref: 592418177284
Node: How do I extract C values from a Python object?18177600
Ref: faq/extending how-do-i-extract-c-values-from-a-python-object18177847
Ref: 592518177847
Node: How do I use Py_BuildValue to create a tuple of arbitrary length?18179093
Ref: faq/extending how-do-i-use-py-buildvalue-to-create-a-tuple-of-arbitrary-length18179325
Ref: 592618179325
Node: How do I call an object’s method from C?18179532
Ref: faq/extending how-do-i-call-an-object-s-method-from-c18179802
Ref: 592718179802
Node: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?18181018
Ref: faq/extending how-do-i-catch-the-output-from-pyerr-print-or-anything-that-prints-to-stdout-stderr18181273
Ref: 592818181273
Node: How do I access a module written in Python from C?18182487
Ref: faq/extending how-do-i-access-a-module-written-in-python-from-c18182746
Ref: 592918182746
Node: How do I interface to C++ objects from Python?18183580
Ref: faq/extending how-do-i-interface-to-c-objects-from-python18183816
Ref: 592a18183816
Node: I added a module using the Setup file and the make fails; why?18184386
Ref: faq/extending i-added-a-module-using-the-setup-file-and-the-make-fails-why18184600
Ref: 592b18184600
Node: How do I debug an extension?18184950
Ref: faq/extending how-do-i-debug-an-extension18185202
Ref: 592c18185202
Node: I want to compile a Python module on my Linux system but some files are missing Why?18185753
Ref: faq/extending i-want-to-compile-a-python-module-on-my-linux-system-but-some-files-are-missing-why18186001
Ref: 592d18186001
Node: How do I tell «incomplete input» from «invalid input»?18186408
Ref: faq/extending how-do-i-tell-incomplete-input-from-invalid-input18186696
Ref: 592e18186696
Node: How do I find undefined g++ symbols __builtin_new or __pure_virtual?18187659
Ref: faq/extending how-do-i-find-undefined-g-symbols-builtin-new-or-pure-virtual18187973
Ref: 592f18187973
Node: Can I create an object class with some methods implemented in C and others in Python e g through inheritance ?18188361
Ref: faq/extending can-i-create-an-object-class-with-some-methods-implemented-in-c-and-others-in-python-e-g-through-inheritance18188608
Ref: 593018188608
Node: Python on Windows FAQ18189162
Ref: faq/windows doc18189320
Ref: 593118189320
Ref: faq/windows python-on-windows-faq18189320
Ref: 593218189320
Ref: faq/windows translation-repo18189320
Ref: 593318189320
Ref: faq/windows windows-faq18189320
Ref: 593418189320
Node: How do I run a Python program under Windows?18189976
Ref: faq/windows faq-run-program-under-windows18190127
Ref: 593518190127
Ref: faq/windows how-do-i-run-a-python-program-under-windows18190127
Ref: 593618190127
Node: How do I make Python scripts executable?18193683
Ref: faq/windows how-do-i-make-python-scripts-executable18193891
Ref: 593718193891
Node: Why does Python sometimes take so long to start?18194453
Ref: faq/windows why-does-python-sometimes-take-so-long-to-start18194666
Ref: 593818194666
Node: How do I make an executable from a Python script?18195545
Ref: faq/windows how-do-i-make-an-executable-from-a-python-script18195752
Ref: 593918195752
Node: Is a * pyd file the same as a DLL?18196003
Ref: faq/windows is-a-pyd-file-the-same-as-a-dll18196212
Ref: 593a18196212
Node: How can I embed Python into a Windows application?18197207
Ref: faq/windows how-can-i-embed-python-into-a-windows-application18197431
Ref: 593b18197431
Node: How do I keep editors from inserting tabs into my Python source?18201880
Ref: faq/windows how-do-i-keep-editors-from-inserting-tabs-into-my-python-source18202117
Ref: 593c18202117
Ref: How do I keep editors from inserting tabs into my Python source?-Footnote-118202985
Node: How do I check for a keypress without blocking?18203027
Ref: faq/windows how-do-i-check-for-a-keypress-without-blocking18203281
Ref: 593d18203281
Node: How do I solve the missing api-ms-win-crt-runtime-l1-1-0 dll error?18203630
Ref: faq/windows how-do-i-solve-the-missing-api-ms-win-crt-runtime-l1-1-0-dll-error18203811
Ref: 593e18203811
Ref: How do I solve the missing api-ms-win-crt-runtime-l1-1-0 dll error?-Footnote-118204317
Node: Graphic User Interface FAQ18204375
Ref: faq/gui doc18204557
Ref: 593f18204557
Ref: faq/gui graphic-user-interface-faq18204557
Ref: 594018204557
Ref: faq/gui translation-repo18204557
Ref: 594118204557
Node: General GUI Questions18204720
Ref: faq/gui general-gui-questions18204848
Ref: 594218204848
Node: What GUI toolkits exist for Python?18204907
Ref: faq/gui what-gui-toolkits-exist-for-python18205061
Ref: 594318205061
Ref: What GUI toolkits exist for Python?-Footnote-118205768
Ref: What GUI toolkits exist for Python?-Footnote-218205810
Ref: What GUI toolkits exist for Python?-Footnote-318205837
Ref: What GUI toolkits exist for Python?-Footnote-418205916
Node: Tkinter questions18205998
Ref: faq/gui tkinter-questions18206122
Ref: 594418206122
Node: How do I freeze Tkinter applications?18206388
Ref: faq/gui how-do-i-freeze-tkinter-applications18206539
Ref: 594518206539
Node: Can I have Tk events handled while waiting for I/O?18207124
Ref: faq/gui can-i-have-tk-events-handled-while-waiting-for-i-o18207334
Ref: 594618207334
Node: I can’t get key bindings to work in Tkinter why?18207809
Ref: faq/gui i-can-t-get-key-bindings-to-work-in-tkinter-why18207973
Ref: 594718207973
Node: «Why is Python Installed on my Computer?» FAQ18208536
Ref: faq/installed doc18208688
Ref: 594818208688
Ref: faq/installed translation-repo18208688
Ref: 594918208688
Ref: faq/installed why-is-python-installed-on-my-computer-faq18208688
Ref: 594a18208688
Node: What is Python?<2>18208910
Ref: faq/installed what-is-python18209059
Ref: 594b18209059
Ref: What is Python?<2>-Footnote-118209538
Node: Why is Python installed on my machine?18209590
Ref: faq/installed why-is-python-installed-on-my-machine18209768
Ref: 594c18209768
Node: Can I delete Python?18210853
Ref: faq/installed can-i-delete-python18211004
Ref: 594d18211004
Node: Deprecations18211732
Ref: deprecations/index doc18211843
Ref: 594e18211843
Ref: deprecations/index deprecations18211843
Ref: 594f18211843
Ref: deprecations/index translation-repo18211843
Ref: 595018211843
Node: Pending removal in Python 3 15<7>18212331
Ref: deprecations/index pending-removal-in-python-3-1518212455
Ref: 595118212455
Ref: Pending removal in Python 3 15<7>-Footnote-118217004
Ref: Pending removal in Python 3 15<7>-Footnote-218217059
Ref: Pending removal in Python 3 15<7>-Footnote-318217114
Ref: Pending removal in Python 3 15<7>-Footnote-418217169
Ref: Pending removal in Python 3 15<7>-Footnote-518217225
Ref: Pending removal in Python 3 15<7>-Footnote-618217267
Ref: Pending removal in Python 3 15<7>-Footnote-718217323
Node: Pending removal in Python 3 16<7>18217379
Ref: deprecations/index pending-removal-in-python-3-1618217545
Ref: 595218217545
Ref: Pending removal in Python 3 16<7>-Footnote-118221783
Ref: Pending removal in Python 3 16<7>-Footnote-218221839
Ref: Pending removal in Python 3 16<7>-Footnote-318221895
Ref: Pending removal in Python 3 16<7>-Footnote-418221951
Node: Pending removal in Python 3 17<4>18222006
Ref: deprecations/index pending-removal-in-python-3-1718222172
Ref: 595318222172
Ref: Pending removal in Python 3 17<4>-Footnote-118225100
Ref: Pending removal in Python 3 17<4>-Footnote-218225158
Ref: Pending removal in Python 3 17<4>-Footnote-318225213
Ref: Pending removal in Python 3 17<4>-Footnote-418225271
Node: Pending removal in Python 3 18<5>18225326
Ref: deprecations/index pending-removal-in-python-3-1818225492
Ref: 595418225492
Ref: Pending removal in Python 3 18<5>-Footnote-118225914
Node: Pending removal in Python 3 19<3>18225969
Ref: deprecations/index pending-removal-in-python-3-1918226139
Ref: 595518226139
Node: Pending removal in future versions<7>18226411
Ref: deprecations/index pending-removal-in-future-versions18226566
Ref: 595618226566
Ref: Pending removal in future versions<7>-Footnote-118233825
Ref: Pending removal in future versions<7>-Footnote-218233880
Ref: Pending removal in future versions<7>-Footnote-318233936
Ref: Pending removal in future versions<7>-Footnote-418233992
Ref: Pending removal in future versions<7>-Footnote-518234048
Ref: Pending removal in future versions<7>-Footnote-618234103
Ref: Pending removal in future versions<7>-Footnote-718234158
Node: C API deprecations18234214
Ref: deprecations/index c-api-deprecations18234327
Ref: 595718234327
Node: Pending removal in Python 3 15<8>18234601
Ref: deprecations/index id118234731
Ref: 595818234731
Ref: Pending removal in Python 3 15<8>-Footnote-118241382
Ref: Pending removal in Python 3 15<8>-Footnote-218241435
Node: Pending removal in Python 3 18<6>18241488
Ref: deprecations/index id218241664
Ref: 595918241664
Ref: Pending removal in Python 3 18<6>-Footnote-118244335
Ref: Pending removal in Python 3 18<6>-Footnote-218244388
Node: Pending removal in future versions<8>18244444
Ref: deprecations/index id318244578
Ref: 595a18244578
Node: Glossary18246413
Ref: glossary doc18246515
Ref: 595b18246515
Ref: glossary glossary18246515
Ref: 1fa718246515
Ref: glossary id118246515
Ref: 595c18246515
Ref: glossary translation-repo18246515
Ref: 595d18246515
Ref: glossary term-018246540
Ref: 49318246540
Ref: glossary term-18246714
Ref: 49418246714
Ref: glossary term-abstract-base-class18247132
Ref: 13be18247132
Ref: glossary term-annotate-function18247968
Ref: 15d18247968
Ref: glossary term-annotation18248268
Ref: 15c18248268
Ref: glossary term-argument18248973
Ref: 67b18248973
Ref: glossary term-asynchronous-context-manager18250407
Ref: 7f118250407
Ref: glossary term-asynchronous-generator18250641
Ref: 247618250641
Ref: glossary term-asynchronous-generator-iterator18251366
Ref: 490018251366
Ref: glossary term-asynchronous-iterable18252108
Ref: f7618252108
Ref: glossary term-asynchronous-iterator18252331
Ref: 4c818252331
Ref: glossary term-atomic-operation18252756
Ref: 25f318252756
Ref: glossary term-attached-thread-state18253238
Ref: 4eba18253238
Ref: glossary term-attribute18254300
Ref: 28f018254300
Ref: glossary term-awaitable18254878
Ref: 4ca18254878
Ref: glossary term-BDFL18255076
Ref: 596118255076
Ref: glossary term-binary-file18255173
Ref: 205818255173
Ref: glossary term-borrowed-reference18255631
Ref: 3d718255631
Ref: glossary term-bytes-like-object18256339
Ref: 19318256339
Ref: glossary term-bytecode18257319
Ref: 4ab18257319
Ref: glossary term-callable18258046
Ref: 2d6118258046
Ref: glossary term-callback18258440
Ref: 2d8218258440
Ref: glossary term-class18258558
Ref: 1ce518258558
Ref: glossary term-class-variable18258723
Ref: 596218258723
Ref: glossary term-closure-variable18258869
Ref: 187b18258869
Ref: glossary term-complex-number18259964
Ref: 596318259964
Ref: glossary term-concurrency18260734
Ref: 596418260734
Ref: glossary term-concurrent-modification18261308
Ref: 596618261308
Ref: glossary term-context18261581
Ref: 194b18261581
Ref: glossary term-context-management-protocol18262171
Ref: 194d18262171
Ref: glossary term-context-manager18262334
Ref: 1e118262334
Ref: glossary term-context-variable18262524
Ref: 596718262524
Ref: glossary term-contiguous18262816
Ref: 266918262816
Ref: glossary term-coroutine18263359
Ref: 6ba18263359
Ref: glossary term-coroutine-function18263682
Ref: f7518263682
Ref: glossary term-CPython18263996
Ref: 90618263996
Ref: glossary term-current-context18264247
Ref: 194c18264247
Ref: glossary term-cyclic-isolate18264719
Ref: 55bd18264719
Ref: glossary term-data-race18265047
Ref: 596018265047
Ref: glossary term-deadlock18265681
Ref: 596d18265681
Ref: glossary term-decorator18266352
Ref: 93b18266352
Ref: glossary term-descriptor18267066
Ref: 186918267066
Ref: glossary term-dictionary18267914
Ref: 23bb18267914
Ref: glossary term-dictionary-comprehension18268120
Ref: 596f18268120
Ref: glossary term-dictionary-view18268465
Ref: 297218268465
Ref: glossary term-docstring18268916
Ref: 22d518268916
Ref: glossary term-duck-typing18269313
Ref: 595e18269313
Ref: glossary term-dunder18270016
Ref: 597018270016
Ref: glossary term-EAFP18270210
Ref: 305e18270210
Ref: glossary term-evaluate-function18270656
Ref: 44d618270656
Ref: glossary term-expression18270855
Ref: 23b518270855
Ref: glossary term-extension-module18271369
Ref: 223a18271369
Ref: glossary term-f-string18271497
Ref: 66b18271497
Ref: glossary term-f-strings18271507
Ref: 597218271507
Ref: glossary term-file-object18271697
Ref: 13cb18271697
Ref: glossary term-file-like-object18272474
Ref: 179418272474
Ref: glossary term-filesystem-encoding-and-error-handler18272537
Ref: 75e18272537
Ref: glossary term-finder18273407
Ref: 235118273407
Ref: glossary term-floor-division18273805
Ref: b4018273805
Ref: glossary term-free-threading18274181
Ref: 1f418274181
Ref: glossary term-free-variable18274476
Ref: 240c18274476
Ref: glossary term-function18274905
Ref: 249118274905
Ref: glossary term-function-annotation18275212
Ref: 200318275212
Ref: glossary term-__future__18275911
Ref: faf18275911
Ref: glossary term-garbage-collection18276544
Ref: 17c018276544
Ref: glossary term-generator18276864
Ref: 126318276864
Ref: glossary term-generator-iterator18277380
Ref: ddb18277380
Ref: glossary term-generator-expression18277770
Ref: 597318277770
Ref: glossary term-generic-function18278175
Ref: be618278175
Ref: glossary term-generic-type18278534
Ref: 1a118278534
Ref: glossary term-GIL18278897
Ref: 16418278897
Ref: glossary term-global-interpreter-lock18278948
Ref: 47418278948
Ref: glossary term-global-state18280396
Ref: 597418280396
Ref: glossary term-hash-based-pyc18280753
Ref: 597518280753
Ref: glossary term-hashable18280967
Ref: 82518280967
Ref: glossary term-IDLE18281883
Ref: 597618281883
Ref: glossary term-immortal18282119
Ref: 29018282119
Ref: glossary term-immutable18282608
Ref: 1fc818282608
Ref: glossary term-import-path18283169
Ref: 242d18283169
Ref: glossary term-importing18283508
Ref: 242018283508
Ref: glossary term-importer18283629
Ref: 242c18283629
Ref: glossary term-interactive18283755
Ref: 1b518283755
Ref: glossary term-interpreted18284251
Ref: 597718284251
Ref: glossary term-interpreter-shutdown18284743
Ref: 47a18284743
Ref: glossary term-iterable18285478
Ref: 142f18285478
Ref: glossary term-iterator18286681
Ref: 4c918286681
Ref: glossary term-key-function18288219
Ref: 100818288219
Ref: glossary term-keyword-argument18289390
Ref: f1018289390
Ref: glossary term-lambda18289438
Ref: 2b9918289438
Ref: glossary term-LBYL18289671
Ref: 597118289671
Ref: glossary term-lexical-analyzer18290413
Ref: 227b18290413
Ref: glossary term-list18290493
Ref: 597818290493
Ref: glossary term-list-comprehension18290677
Ref: 8de18290677
Ref: glossary term-lock18291095
Ref: 596918291095
Ref: glossary term-loader18291917
Ref: 1a1018291917
Ref: glossary term-locale-encoding18292279
Ref: 54b18292279
Ref: glossary term-magic-method18292739
Ref: 464f18292739
Ref: glossary term-mapping18292811
Ref: 13c318292811
Ref: glossary term-meta-path-finder18293217
Ref: 127218293217
Ref: glossary term-metaclass18293515
Ref: 23b618293515
Ref: glossary term-method18294255
Ref: 184c18294255
Ref: glossary term-method-resolution-order18294564
Ref: 25bd18294564
Ref: glossary term-module18294850
Ref: 19c618294850
Ref: glossary term-module-spec18295112
Ref: 234a18295112
Ref: glossary term-MRO18295319
Ref: 18c518295319
Ref: glossary term-mutable18295371
Ref: 1fcd18295371
Ref: glossary term-named-tuple18295751
Ref: 85f18295751
Ref: glossary term-namespace18296969
Ref: 202918296969
Ref: glossary term-namespace-package18297725
Ref: 2b218297725
Ref: glossary term-native-code18298304
Ref: 596b18298304
Ref: glossary term-nested-scope18298693
Ref: 237318298693
Ref: glossary term-new-style-class18299182
Ref: 2cf018299182
Ref: glossary term-non-deterministic18299509
Ref: 596818299509
Ref: glossary term-object18299967
Ref: 597918299967
Ref: glossary term-optimized-scope18300131
Ref: 4a218300131
Ref: glossary term-optional-module18300662
Ref: 214318300662
Ref: glossary term-package18301074
Ref: 23318301074
Ref: glossary term-parallelism18301345
Ref: 596518301345
Ref: glossary term-parameter18301868
Ref: 233218301868
Ref: glossary positional-only-parameter18302408
Ref: c7a18302408
Ref: glossary keyword-only-parameter18302808
Ref: 5a518302808
Ref: glossary term-path-entry18304319
Ref: 243b18304319
Ref: glossary term-path-entry-finder18304473
Ref: 127318304473
Ref: glossary term-path-entry-hook18304797
Ref: 243d18304797
Ref: glossary term-path-based-finder18304998
Ref: 243018304998
Ref: glossary term-path-like-object18305134
Ref: 5a118305134
Ref: glossary term-PEP18305767
Ref: 597b18305767
Ref: glossary term-portion18306421
Ref: 242718306421
Ref: glossary term-positional-argument18306582
Ref: f1118306582
Ref: glossary term-provisional-API18306634
Ref: 3d118306634
Ref: glossary term-provisional-package18307636
Ref: 124418307636
Ref: glossary term-Python-300018307695
Ref: 597c18307695
Ref: glossary term-Pythonic18307886
Ref: 597d18307886
Ref: glossary term-qualified-name18308526
Ref: 1d0c18308526
Ref: glossary term-race-condition18309369
Ref: 595f18309369
Ref: glossary term-reference-count18310016
Ref: 4eb218310016
Ref: glossary term-regular-package18310812
Ref: 242418310812
Ref: glossary term-reentrant18310977
Ref: 596e18310977
Ref: glossary term-REPL18311910
Ref: 49218311910
Ref: glossary term-__slots__18312040
Ref: 7f818312040
Ref: glossary term-sequence18312386
Ref: 71718312386
Ref: glossary term-set-comprehension18313513
Ref: 597e18313513
Ref: glossary term-single-dispatch18313829
Ref: be718313829
Ref: glossary term-slice18313980
Ref: 25ba18313980
Ref: glossary term-soft-deprecated18314305
Ref: 23d18314305
Ref: glossary term-special-method18314677
Ref: 1c4818314677
Ref: glossary term-standard-library18314957
Ref: 597a18314957
Ref: glossary term-statement18315467
Ref: 2be218315467
Ref: glossary term-static-type-checker18315709
Ref: 57418315709
Ref: glossary term-stdlib18315916
Ref: 176e18315916
Ref: glossary term-strong-reference18315979
Ref: 5e218315979
Ref: glossary term-synchronization-primitive18316637
Ref: 596a18316637
Ref: glossary term-t-string18317353
Ref: 597f18317353
Ref: glossary term-t-strings18317363
Ref: 598018317363
Ref: glossary term-text-encoding18317530
Ref: 25b718317530
Ref: glossary term-text-file18318048
Ref: 205718318048
Ref: glossary term-thread-state18318572
Ref: 182e18318572
Ref: glossary term-thread-safe18319596
Ref: 596c18319596
Ref: glossary term-token18320310
Ref: 227118320310
Ref: glossary term-triple-quoted-string18320692
Ref: 598118320692
Ref: glossary term-type18321191
Ref: 1ce618321191
Ref: glossary term-type-alias18321425
Ref: 66e18321425
Ref: glossary term-type-hint18322006
Ref: 23b118322006
Ref: glossary term-universal-newlines18322607
Ref: f3718322607
Ref: glossary term-variable-annotation18322981
Ref: f5318322981
Ref: glossary term-virtual-environment18323708
Ref: 20d718323708
Ref: glossary term-virtual-machine18324017
Ref: 3a4118324017
Ref: glossary term-walrus-operator18324183
Ref: 598218324183
Ref: glossary term-Zen-of-Python18324364
Ref: 598318324364
Ref: Glossary-Footnote-118324629
Ref: Glossary-Footnote-218324671
Ref: Glossary-Footnote-318324713
Ref: Glossary-Footnote-418324755
Ref: Glossary-Footnote-518324797
Ref: Glossary-Footnote-618324839
Ref: Glossary-Footnote-718324881
Ref: Glossary-Footnote-818324923
Ref: Glossary-Footnote-918324965
Ref: Glossary-Footnote-1018325007
Ref: Glossary-Footnote-1118325050
Ref: Glossary-Footnote-1218325089
Ref: Glossary-Footnote-1318325132
Ref: Glossary-Footnote-1418325175
Ref: Glossary-Footnote-1518325218
Ref: Glossary-Footnote-1618325261
Ref: Glossary-Footnote-1718325293
Ref: Glossary-Footnote-1818325336
Ref: Glossary-Footnote-1918325379
Ref: Glossary-Footnote-2018325422
Ref: Glossary-Footnote-2118325465
Ref: Glossary-Footnote-2218325508
Ref: Glossary-Footnote-2318325551
Ref: Glossary-Footnote-2418325594
Ref: Glossary-Footnote-2518325637
Ref: Glossary-Footnote-2618325680
Ref: Glossary-Footnote-2718325723
Ref: Glossary-Footnote-2818325766
Ref: Glossary-Footnote-2918325809
Ref: Glossary-Footnote-3018325852
Ref: Glossary-Footnote-3118325895
Ref: Glossary-Footnote-3218325938
Ref: Glossary-Footnote-3318325981
Ref: Glossary-Footnote-3418326024
Ref: Glossary-Footnote-3518326067
Ref: Glossary-Footnote-3618326127
Ref: Glossary-Footnote-3718326170
Ref: Glossary-Footnote-3818326213
Ref: Glossary-Footnote-3918326256
Ref: Glossary-Footnote-4018326299
Ref: Glossary-Footnote-4118326342
Node: About this documentation18326385
Ref: about doc18326501
Ref: 598418326501
Ref: about about-this-documentation18326501
Ref: 598518326501
Ref: about translation-repo18326501
Ref: 598618326501
Ref: About this documentation-Footnote-118327516
Ref: About this documentation-Footnote-218327565
Ref: About this documentation-Footnote-318327601
Node: Contributors to the Python documentation18327642
Ref: about contributors-to-the-python-documentation18327743
Ref: 598718327743
Ref: Contributors to the Python documentation-Footnote-118328201
Node: Come comportarsi con i bug18328263
Ref: bugs doc18328380
Ref: 598818328380
Ref: bugs dealing-with-bugs18328380
Ref: 598918328380
Ref: bugs reporting-bugs18328380
Ref: 4f0218328380
Ref: bugs translation-repo18328380
Ref: 598a18328380
Node: Errori nella Documentazione18329056
Ref: bugs documentation-bugs18329194
Ref: 598c18329194
Ref: Errori nella Documentazione-Footnote-118330473
Ref: Errori nella Documentazione-Footnote-218330522
Ref: Errori nella Documentazione-Footnote-318330576
Ref: Errori nella Documentazione-Footnote-418330628
Ref: Errori nella Documentazione-Footnote-518330714
Ref: Errori nella Documentazione-Footnote-618330759
Ref: Errori nella Documentazione-Footnote-718330835
Node: Utilizzo dell’Issue Tracker di Python18330898
Ref: bugs using-the-python-issue-tracker18331094
Ref: 598d18331094
Ref: bugs using-the-tracker18331094
Ref: 55718331094
Ref: Utilizzo dell’Issue Tracker di Python-Footnote-118333537
Ref: Utilizzo dell’Issue Tracker di Python-Footnote-218333600
Node: Come iniziare a contribuire a Python in autonomia18333666
Ref: bugs contributing-to-python18333826
Ref: 598b18333826
Ref: bugs getting-started-contributing-to-python-yourself18333826
Ref: 598e18333826
Ref: Come iniziare a contribuire a Python in autonomia-Footnote-118334371
Ref: Come iniziare a contribuire a Python in autonomia-Footnote-218334408
Node: Copyright18334484
Ref: copyright doc18334593
Ref: 598f18334593
Ref: copyright copyright18334593
Ref: 599018334593
Ref: copyright translation-repo18334593
Ref: 599118334593
Node: Storia e licenza18335147
Ref: license doc18335254
Ref: 599318335254
Ref: license history-and-license18335254
Ref: 599218335254
Ref: license id118335254
Ref: 599418335254
Ref: license translation-repo18335254
Ref: 599518335254
Node: Storia del software18335446
Ref: license history-of-the-software18335582
Ref: 599618335582
Node: Termini e condizioni di accesso o di utilizzo di Python18340414
Ref: license terms-and-conditions-for-accessing-or-otherwise-using-python18340611
Ref: 599718340611
Node: PYTHON SOFTWARE FOUNDATION LICENSE VERSION 218341686
Ref: license psf-license18341880
Ref: 599a18341880
Ref: license python-software-foundation-license-version-218341880
Ref: 599b18341880
Node: CONTRATTO DI LICENZA DI BEOPEN COM PER PYTHON 2 018344497
Ref: license beopen-com-license-agreement-for-python-2-018344742
Ref: 599c18344742
Node: CNRI CONTRATTO DI LICENZA PER PYTHON 1 6 118347462
Ref: license cnri-license-agreement-for-python-1-6-118347713
Ref: 599d18347713
Node: CWI CONTRATTO DI LICENZA PER PYTHON DA 0 9 0 A 1 218351897
Ref: license cwi-license-agreement-for-python-0-9-0-through-1-218352159
Ref: 599e18352159
Node: ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON DOCUMENTATION18353429
Ref: license bsd018353640
Ref: 599818353640
Ref: license zero-clause-bsd-license-for-code-in-the-python-documentation18353640
Ref: 599f18353640
Node: Licenze e riconoscimenti per il software incorporato18354430
Ref: license licenses-and-acknowledgements-for-incorporated-software18354599
Ref: 59a018354599
Ref: license otherlicenses18354599
Ref: 599918354599
Node: Mersenne Twister18355382
Ref: license mersenne-twister18355502
Ref: 59a118355502
Node: Socket18357821
Ref: license sockets18357977
Ref: 59a218357977
Node: Servizi di socket asincrone18359808
Ref: license asynchronous-socket-services18359967
Ref: 59a318359967
Node: Gestione dei cookie18361203
Ref: license cookie-management18361388
Ref: 59a418361388
Node: Tracciabilità dell’esecuzione18362606
Ref: license execution-tracing18362792
Ref: 59a518362792
Node: Funzioni UUencode e UUdecode18364076
Ref: license uuencode-and-uudecode-functions18364275
Ref: 59a618364275
Node: Chiamate di procedura remota XML18365844
Ref: license xml-remote-procedure-calls18366021
Ref: 59a718366021
Node: test_epoll18367555
Ref: license test-epoll18367717
Ref: 59a818367717
Node: Select kqueue18368982
Ref: license select-kqueue18369121
Ref: 59a918369121
Node: SipHash2418370672
Ref: license siphash2418370814
Ref: 59aa18370814
Node: strtod e dtoa18371997
Ref: license strtod-and-dtoa18372137
Ref: 59ab18372137
Node: 7 4 OpenSSL18373530
Ref: license openssl18373666
Ref: 59ac18373666
Node: expat18384592
Ref: license expat18384721
Ref: 59ad18384721
Node: libffi18386127
Ref: license libffi18386252
Ref: 59ae18386252
Node: zlib<4>18387633
Ref: license zlib18387760
Ref: 59af18387760
Node: cfuhash18389002
Ref: license cfuhash18389131
Ref: 59b018389131
Node: libmpdec18390949
Ref: license libmpdec18391090
Ref: 59b118391090
Node: W3C C14N test suite18392700
Ref: license w3c-c14n-test-suite18392842
Ref: 59b218392842
Node: mimalloc18394744
Ref: license mimalloc18394889
Ref: 59b318394889
Ref: license mimalloc-license18394889
Ref: 65618394889
Node: asyncio<15>18396102
Ref: license asyncio18396258
Ref: 59b418396258
Ref: asyncio<15>-Footnote-118397615
Node: Global Unbounded Sequences GUS18397673
Ref: license global-unbounded-sequences-gus18397839
Ref: 59b518397839
Ref: Global Unbounded Sequences GUS-Footnote-118399519
Node: Zstandard bindings18399597
Ref: license zstandard-bindings18399743
Ref: 59b618399743
Ref: Zstandard bindings-Footnote-118401682
Node: Indice del modulo Python18401725
Node: Indice18421421
Ref: library/stdtypes tuple index20620535
Ref: 196020620536
Ref: library/stdtypes tuple count20620538
Ref: library/time audit_event_time_sleep_020620540
Ref: library/asyncio audit_event_cpython_run_stdin_220620542
Ref: library/sys audit_event_cpython_remote_debugger_script_020620544
Ref: 473d20620546
Ref: using/cmdline audit_event_cpython_run_stdin_020620548
Ref: 474120620550
Ref: 60320620552
Ref: library/_thread start_new_thread20620554
Ref: 474220620556
Ref: 200f20620558
Ref: library/sys script_path20620560
Ref: using/cmdline audit_event_cpython_run_stdin_120620562
Ref: 153e20620564
Ref: 8dd20620566
Ref: library/stdtypes list insert20620568
Ref: 473e20620570
Ref: 1a4320620572
Ref: library/unittest unittest tearDownModule20620574
Ref: 13a020620576
Ref: library/stdtypes list pop20620578
Ref: library/stdtypes list extend20620580
Ref: library/ctypes audit_event_ctypes_memoryview_at_020620582
Ref: 474920620584
Ref: 473a20620586
Ref: library/stdtypes list remove20620588
Ref: 15cb20620590
Ref: library/stdtypes list clear20620592
Ref: 474020620594
Ref: 60220620596
Ref: 474b20620598
Ref: library/stdtypes range index20620600
Ref: 473f20620602
Ref: library/stdtypes list append20620604
Ref: 15ca20620606
Ref: using/cmdline audit_event_cpython_run_file_020620608

End Tag Table


Local Variables:
coding: utf-8
End:
